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Find video protocols related to scientific articles indexed in Pubmed.
EPGA: de novo assembly using the distributions of reads and insert size.
Bioinformatics
PUBLISHED: 11-20-2014
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In genome assembly, the primary issue is how to determine upstream and downstream sequence regions of sequence seeds for constructing long contigs or scaffolds. When extending one sequence seed, repetitive regions in the genome always cause multiple feasible extension candidates which increase the difficulty of genome assembly. The universally accepted solution is choosing one based on read overlaps and paired-end (mate-pair) reads. However, this solution faces difficulties with regard to some complex repetitive regions. In addition, sequencing errors may produce false repetitive regions and uneven sequencing depth leads some sequence regions to have too few or too many reads. All the aforementioned problems prohibit existing assemblers from getting satisfactory assembly results.
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LASP1 is a HIF-1? target gene critical for metastasis of pancreatic cancer.
Cancer Res.
PUBLISHED: 11-12-2014
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LASP1 is an actin-binding protein associated with actin assembly dynamics in cancer cells. Here we report that LASP1 is overexpressed in pancreatic ductal adenocarcinoma (PDAC) where it promotes invasion and metastasis. We found that LASP1 overexpression in PDAC cells was mediated by HIF-1? through direct binding to a hypoxia response element in the LASP1 promoter. HIF-1? stimulated LASP1 expression in PDAC cells in vitro and mouse tumor xenografts in vivo. Clinically, LASP1 overexpression in PDAC patient specimens was associated significantly with lymph node metastasis and overall survival. Overall, our results defined LASP1 as a direct target gene for HIF-1? upregulation that is critical for metastatic progression of PDAC.
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Does the timing of an invasive mesenteric angiography following a positive CT mesenteric angiography make a difference?
Int J Colorectal Dis
PUBLISHED: 10-25-2014
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Computed tomographic mesenteric angiography (CTMA) is integral in the management of patients with acute lower gastrointestinal tract bleeding (LGIB). An invasive mesenteric angiography (MA) with a view to embolize the site of bleeding is usually performed if active contrast extravasation was seen on the CTMA scans. However, the bleeding may have ceased by the time the invasive MA is performed. This study aims to identify predictors for active extravasation in invasive MA following a positive CTMA in patients with massive LGIB.
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Characterization of Bovine Interferon ?1: Expression in Yeast Pichia pastoris, Biological Activities, and Physicochemical Characteristics.
J. Interferon Cytokine Res.
PUBLISHED: 10-25-2014
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A bovine interferon ? (BoIFN?) gene that included signal sequence was amplified from bovine liver genomic DNA. The gene was named BoIFN-?1 according to the position at which the encoded gene of the bovine IFN was located in the bovine genome. The sequence included a 23-amino-acid signal peptide and a 166-amino-acid mature peptide. The structural characteristics and phylogenetic relationships of the BoIFN-?1 gene were analyzed. A recombinant mature BoIFN-?1 (rBoIFN-?1) was expressed in the yeast Pichia pastoris. Physicochemical characteristics and antiviral activity were determined in vitro. Recombinant BoIFN-?1 was found to be highly sensitive to trypsin and stable at pH 2.0 or 65°C. It also exhibited antiviral activity, which was neutralized by a rabbit anti-rBoIFN? polyclonal antibody. This study revealed that rBoIFN-?1 has the typical characteristics of IFN? and can be used for both research and industrial application.
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Optical design of a street lamp based on dual-module chip-on-board LED arrays.
Appl Opt
PUBLISHED: 10-17-2014
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We design and propose a compact street lamp based on dual-module chip-on-board LED. The street lamp is composed of six faceted reflectors. It can direct the luminous flux and form uniform illumination on the target area, and it effectively reduces power consumption. We have conducted both simulations and prototype measurements. The test results show good optical performance in that the uniformity of luminance reaches 0.58 for LED lamp zigzag arrangements and 0.60 for LED lamp double-side arrangements. The average luminance can fulfill the requirements in Chinese road lighting Standard CJJ45-2006.
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Learning Computational Models of Video Memorability from fMRI Brain Imaging.
IEEE Trans Cybern
PUBLISHED: 10-15-2014
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Generally, various visual media are unequally memorable by the human brain. This paper looks into a new direction of modeling the memorability of video clips and automatically predicting how memorable they are by learning from brain functional magnetic resonance imaging (fMRI). We propose a novel computational framework by integrating the power of low-level audiovisual features and brain activity decoding via fMRI. Initially, a user study experiment is performed to create a ground truth database for measuring video memorability and a set of effective low-level audiovisual features is examined in this database. Then, human subjects' brain fMRI data are obtained when they are watching the video clips. The fMRI-derived features that convey the brain activity of memorizing videos are extracted using a universal brain reference system. Finally, due to the fact that fMRI scanning is expensive and time-consuming, a computational model is learned on our benchmark dataset with the objective of maximizing the correlation between the low-level audiovisual features and the fMRI-derived features using joint subspace learning. The learned model can then automatically predict the memorability of videos without fMRI scans. Evaluations on publically available image and video databases demonstrate the effectiveness of the proposed framework.
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Bimagnetic h-Co/h-CoO nanotetrapods: preparation, nanoscale characterization, three-dimensional architecture and their magnetic properties.
Nanoscale
PUBLISHED: 10-07-2014
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Well-defined bimagnetic h-Co decorated wurtzite h-CoO nanotetrapods with uniform size have been successfully fabricated by a one-pot thermal decomposition method for the first time, and their three-dimensional architecture, crystal structure, chemical phase and exchange bias effect are characterized at the nanoscale. It is found that individual bimagnetic h-Co/h-CoO nanotetrapods are made of a h-CoO nanotetrapod skeleton to which multiple nanocrystals of ferromagnetic metallic h-Co are directly attached. The chemical analysis shows that the mass ratio of h-CoO and h-Co is 65?:?35. The detailed investigations of the crystal structure reveal that both the h-CoO nanotetrapod skeleton and h-Co nanoparticles have hexagonal structure. The four pods of individual nanotetrapods are single crystals with the same [001] orientation along with their pod axes and grow together by twinning with (110) the twin interface and the 120° spatial boundary angle. The magnetic measurements reveal that the h-Co/h-CoO nanotetrapods have a surprisingly strong room temperature ferromagnetism and there exists a weak exchange coupling between the h-CoO nanotetrapod skeleton and the decorated h-Co tiny nanoparticles. It is believed that our new structural form of the bimagnetic h-Co/h-CoO nanotetrapods provides not only a smart functional 3D nanoarchitecture as building block in nanoelectronics and nanosensors, but also an ideal specimen for a further understanding of weak antiferromagnetic-ferromagnetic interaction.
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The Effects of a Semi-constrained Integrated Artificial Disc on Zygapophyseal Joint Pressure and Displacement.
Spine
PUBLISHED: 10-02-2014
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Study Design. Measurement of zygapophyseal joint pressure and displacement were performed after placement of a semiconstrained integrated artificial disc in a cadaver model.Objective. To understand the likelihood of accelerated zygapophyseal joints degeneration as a result of the implant.Summary of Background Data. A semiconstrained integrated artificial disc (SIAD) has been developed to treat lumbar spondylosis secondary to segmental disc degeneration and spinal stenosis. The SIAD replaces the stenotic segment's disc. Previous studies have demonstrated that non-constrained artificial disc (NAD) replacements fail to achieve their optimal long-term outcomes likely because of significantly increased zygapophyseal joint pressure and displacement at the implanted level. Moreover, clinical studies have reported an increased incidence of zygapophyseal joint degeneration after lumbar disc replacement.Methods. Eight cadaver lumbar specimens (L2-L5) were loaded in flexion, neutral, extension, left bend (LB), and right rotation (RR). Zygapophyseal joint pressure and displacement were measured during each of the five positions at each of the three levels with the ratio of deformation (RD) calculated under the different loads. An artificial disc was placed at the L3-4 level, and the measurements were repeated.Results. Following L3-4 segment implantation, the pressure in the zygapophyseal joint at operative segment were not significant changed by SIAD and NAD implantation in AC and flexion, compared to physiological disc. Notable differences in zygapophyseal joint pressure between the SIAD and NAD were identified at the operative level in extension, LB, and RR. The adjacent-level effect of NAD was significantly greater than SIAD. The RD difference between the two discs was increased by load experienced in extension, flexion, LB, and RR.Conclusions. The SIAD provided a superior biomechanical milieu for zygapophyseal joints at the implanted and adjacent levels compared to NAD, which may avoid the acceleration of post-operative zygapophyseal joint degeneration.
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Nanoscale characterization of 1D Sn-3.5Ag nanosolders and their application into nanowelding at the nanoscale.
Nanotechnology
PUBLISHED: 09-29-2014
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One-dimensional Sn-3.5Ag alloy nanosolders have been successfully fabricated by a dc electrodeposition technique into nanoporous templates, and their soldering quality has been demonstrated in nanoscale electrical welding for the first time, which indicates that they can easily form remarkably reliable conductive joints. The electrical measurement shows that individual 1D Sn-3.5Ag nanosolders have a resistivity of 28.9 ??·cm. The morphology, crystal structure and chemistry of these nanosolders have been characterized at the nanoscale. It is found that individual 1D Sn-3.5Ag alloy nanosolders have a continuous morphology and smooth surface. XPS confirms the presence of tin and silver with a mass ratio of 96.54:3.46, and EDX elemental mappings clearly reveal that the Sn and Ag elements have a uniform distribution. Coveragent beam electron diffractions verify that the crystal phases of individual 1D Sn-3.5Ag alloy nanosolders consist of matrix ?-Sn and the intermetallic compound Ag3Sn. The reflow experiments reveal that the eutectic composition of the 1D Sn-Ag alloy nanowire is shifted to the Sn rich corner. This work may contribute one of the most important tin-based alloy nanosolders for future nanoscale welding techniques, which are believed to have broad applications in nanotechnology and the future nano-industry.
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Celeribacter indicus sp. nov. a polycyclic aromatic hydrocarbon-degrading bacterium from deep-sea sediment and reclassification of Huaishuia halophila as Celeribacter halophilus comb. nov.
Int. J. Syst. Evol. Microbiol.
PUBLISHED: 09-27-2014
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A taxonomic study was carried out on strain P73T, which was isolated from deep-sea sediment of the Indian Ocean by enrichment of polycyclic aromatic hydrocarbons. It can degrade biphenyl, naphthalene, 2-methylnaphthalene, 2,6-dimethylnaphthalene, acenaphthene, anthracene, phenanthrene, dibenzothiophene, dibenzofuran, fluorene, 4-methyldibenzothiophene and fluoranthene, but not pyrene or chrysene. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain P73T formed a clade with the genera Celeribacter and Huaishuia within the family Rhodobacteraceae, with highest sequence similarity of 96.98% to Celeribacter neptunius H14T, followed by Huaishuia halophila ZXM137T (96.42%). The bacterium was Gram-negative, oxidase and catalase positive, rod shaped and non-motile. Growth was observed at salinities from 0.5 to 12% and at temperatures from 10 to 41 °C. The principal fatty acids (>10%) of strain P73T were Sum In Feature 8 (C18:1?7c/?6c) (58.6%) and C19:0?8c cyclo (17.4%). The respiratory quinone was Q-10 (100%). The major lipids were phosphatidylglycerol, one unknown aminolipid, one unknown phospholipid and one unknown lipid, with minor lipids of one unknown phospholipid and one unknown glycolipid. The G+C content of the chromosomal DNA was 66.0 mol%. The combined genotypic and phenotypic data show that strain P73T represents a novel species of the genus Celeribacter, for which the name Celeribacter indicus sp. nov. is proposed, with the type strain P73T (= MCCC 1A01112T =LMG 27600T = DSM 27257T). Phylogenetic study and existing phenotypic information also show that Huaishuia halophila should be transferred to the genus Celeribacter as Celeribacter halophilus comb. nov. (type strain ZXM137T =CGMCC 1.8891T = LMG 24854T).
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[Rapid screening and confirmation of antidepressants in blood using automated solid phase extraction and liquid chromatography-time-of-flight mass spectrometry].
Se Pu
PUBLISHED: 09-27-2014
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A high-throughput method was developed for screening antidepressants in blood by automated solid phase extraction and liquid chromatography with high resolution quadrupole-time-of-flight mass spectrometry (ASPE-LC-Q-TOF/MS). The samples were cleaned up by an HLB solid phase extraction cartridge and analyzed by LC-Q-TOF/MS under electrospray ionization (ESI) mode with scanning range of m/z 50-1 000 Da. The chromatographic separation was performed on an Agilent Eclipse Plus C18 column (50 mm x 2.1 mm, 1.8 microm) with gradient elution using methanol and 5 mmol/L ammonium formate aqueous solution (containing 0.2% formic acid) as mobile phases. Rapid screening and confirmation can be achieved using MS matching scores, deviation of retention time, measured mass, isotopic abundance matching scores, isotope space matching scores and MS/MS matching scores. The quantitative analysis was carried out by correlating the extracting peak area with accurate mass. Good linearities were observed in the range of 1 - 500 microg/L with the correlation coefficients from 0.997 6 to 0.999 7. The limits of detection were 0.01-0.5 microg/L. The spiked recoveries were 79.6%-96.4% with the relative standard deviations of 4.1% - 6.4%. The result screening database was built using Agilent MassHunter PCDL Manager software and then used for the analysis of spiked samples. MS matching scores, isotopic abundance matching scores, isotope space matching scores (all > 95 points) and MS/MS matching scores (> 70 points) were applied to identify the analytes. The results showed that all the spiked antidepressants could be correctly identified with low deviation of retention time (< 0.1 min) and mass (< 1 mDa). The developed method was further applied for the analysis of poisoning cases, and amitriptyline, carbamazepine, doxepin were detected. In brief, the method is rapid, sensitive, simple, reliable, and suitable for the screening and confirmation of antidepressants in forensic and clinical analytical toxicology.
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Specific oriented metal-organic framework membranes and their facet-tuned separation performance.
ACS Appl Mater Interfaces
PUBLISHED: 09-12-2014
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Modulating the crystal morphology, or the exposed crystal facets, of metal-organic frameworks (MOFs) expands their potential applications in catalysis, adsorption, and separation. In this article, by immobilizing the citrate modulators on Au nanoparticles and subsequently being fixed on solid copper hydroxide nanostrands, a well-intergrown and oriented HKUST-1 cube crystal membrane was formed at room temperature. In contrast, in the absence of Au nanoparticles, well-intergrown and oriented cuboctahedron and octahedron membranes were formed in water/ethanol and ethanol, respectively. The gas separation performances of these HKUST-1 membranes were tuned via their exposed facets with defined pore sizes. The HKUST-1 cube membrane with exposed {001} facets demonstrated the highest permeance but lowest gas binary separation factors, while the octahedron membrane with exposed {111} facets presented the highest separation factors but lowest permeance, since the window size of {111} facets is 0.46 nm which is smaller than 0.9 nm of {001} facets. Separation of 0.38 nm CO2 from 0.55 nm SF6 was realized by the HKUST-1 octahedron membrane. As a proof of concept, this will open a new way to design MOF-related separation membranes by facet controlling.
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Quasi-Ideal Memory System.
IEEE Trans Cybern
PUBLISHED: 09-10-2014
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The definition for ideal memory system is so strict that some physical elements cannot exist in the real world. In this paper, an ideal memory system can be extended to generate 15 different kinds of quasi-ideal memory systems, which are included in memory systems as its special cases and are different from ideal memory system. For a system to be a quasi-ideal memory system, it should show three unique fingerprints: 1) the pinched hysteretic loop of a quasi-ideal memory system must be odd symmetrical in the plane; 2) the pinched hysteretic loop of a quasi-ideal memory system must be "self-crossing"; and 3) the slope of tangent line for the pinched hysteresis loop must be strictly monotone in a given period.
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An Aggregation-Induced-Emission Platform for Direct Visualization of Interfacial Dynamic Self-Assembly.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 09-02-2014
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An in-depth understanding of dynamic interfacial self-assembly processes is essential for a wide range of topics in theoretical physics, materials design, and biomedical research. However, direct monitoring of such processes is hampered by the poor imaging contrast of a thin interfacial layer. We report in situ imaging technology capable of selectively highlighting self-assembly at the phase boundary in real time by employing the unique photophysical properties of aggregation-induced emission. Its application to the study of breath-figure formation, an immensely useful yet poorly understood phenomenon, provided a mechanistic model supported by direct visualization of all main steps and fully corroborated by simulation and theoretical analysis. This platform is expected to advance the understanding of the dynamic phase-transition phenomena, offer insights into interfacial biological processes, and guide development of novel self-assembly technologies.
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Generation and characterization of polyclonal antibody against part of immunoglobulin constant heavy ? chain of goose.
Monoclon Antib Immunodiagn Immunother
PUBLISHED: 08-30-2014
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Immunoglobulin Y (abbreviated as IgY) is a type of immunoglobulin that is the major antibody in bird, reptile, and lungfish blood. IgY consists of two light (?) and two heavy (?) chains. In the present study, polyclonal antibody against IgYFc was generated and evaluated. rIgYC?3/C?4 was expressed in Escherichia coli, purified and utilized to raise polyclonal antibody in rabbit. High affinity antisera were obtained, which successfully detected the antigen at a dilution of 1:204,800 for ELISA assay. The antibody can specifically recognize both rIgYC?3/C?4 and native IgY by Western bolt analysis. Furthermore, the serum of Grus japonensis or immunoglobulin of chicken, duck, turkey, and silkie samples and dynamic changes of serum GoIgY after immunogenicity with GPV-VP3-virus-like particles (GPV-VP3-VLPs) can be detected with the anti-GoIgYFc polyclonal antibody. These results suggested that the antibody is valuable for the investigation of biochemical properties and biological functions of GoIgY.
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T-cell-mediated cross-strain protective immunity elicited by prime-boost vaccination with a live attenuated influenza vaccine.
Int. J. Infect. Dis.
PUBLISHED: 08-27-2014
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Antigenic drift and shift of influenza viruses require frequent reformulation of influenza vaccines. In addition, seasonal influenza vaccines are often mismatched to the epidemic influenza strains. This stresses the need for a universal influenza vaccine.
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Simultaneous determination of florfenicol with its metabolite based on modified quick, easy, cheap, effective, rugged, and safe sample pretreatment and evaluation of their degradation behavior in agricultural soils.
J Sep Sci
PUBLISHED: 08-24-2014
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A simple and simultaneous method for the determination of florfenicol and its metabolite florfenicol amine in agricultural soils using modified quick, easy, cheap, effective, rugged, and safe sample pretreatment and reversed-phase high-performance liquid chromatography with tandem mass spectrometry is presented. Florfenicol and its metabolite florfenicol amine residues in agricultural soils were extracted with alkalized acetonitrile and an aliquot was cleaned up with Si(CH2 )3 NH (CH2 )2 NH2 and C18 sorbent, which were powder materials. High-performance liquid chromatography with tandem mass spectrometry was applied to simultaneously determine the level of florfenicol and florfenicol amine in agricultural soils. Excellent linearity was achieved for florfenicol and florfenicol amine over a range of concentrations from 0.1-500 ?g/L with coefficients more than 0.99. Average recoveries at four different levels (0.005, 0.05, 0.5 and 5.0 mg/kg) for florfenicol and florfenicol amine ranged from 73.6-94.9% with relative standard deviations of 2.9-12.5%. The limits of detection for florfenicol and florfenicol amine in agricultural soils were 2.0 ?g/kg, and the limits of quantification were 6.0 ?g/kg. Based on this method, the degradation behavior of florfenicol and its metabolite florfenicol amine in three soils (Nanchang, Hangzhou, and Changchun) under sterilized and native conditions was investigated and the transformation rate of florfenicol amine from florfenicol was evaluated. This article is protected by copyright. All rights reserved.
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Characterization of an Enterovirus species E isolated from naturally infected bovine in China.
Virus Res.
PUBLISHED: 08-05-2014
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Bovine enteroviruses, which belong to the Picornaviridae family, can cause clinical symptoms in cattle and are excreted in feces. In this study, a cytolytic virus was isolated from Madin-Darby bovine kidney (MDBK) cells from fecal samples of bovine with severe diarrhea and hemorrhagic intestinal mucosa that had been originally diagnosed with bovine viral diarrhea (BVD) by a bovine viral diarrhea virus Ag point-of-care test (IDEXX, American). Random priming PCR was used to amplify underlying viral sequences and identify the isolated virus. Phylogenetic analysis indicated that the isolated virus closely matches the EV-E2 species, which is different from other Chinese strains previously isolated. The newly identified virus was named HLJ-3531/2013. We infected the sulking mice with the isolated virus. Reverse-transcription PCR, hematoxylin and eosin (HE) staining, serum neutralization (SN) test, and virus isolation from various tissues revealed that HLJ-3531/2013 can infect the intestine, liver, and lung of suckling mice. The present work is the first to report the reproduction of clinical symptoms by an isolated virus in an experimental infection model of animals and lays a solid foundation for the development of the pathogenesis of bovine enteroviruses.
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Chrysin Protects against Focal Cerebral Ischemia/Reperfusion Injury in Mice through Attenuation of Oxidative Stress and Inflammation.
Int J Mol Sci
PUBLISHED: 07-30-2014
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Inflammation and oxidative stress play an important part in the pathogenesis of focal cerebral ischemia/reperfusion (I/R) injury, resulting in neuronal death. The signaling pathways involved and the underlying mechanisms of these events are not fully understood. Chrysin, which is a naturally occurring flavonoid, exhibits various biological activities. In this study, we investigated the neuroprotective properties of chrysin in a mouse model of middle cerebral artery occlusion (MCAO). To this end, male C57/BL6 mice were pretreated with chrysin once a day for seven days and were then subjected to 1 h of middle cerebral artery occlusion followed by reperfusion for 24 h. Our data show that chrysin successfully decreased neurological deficit scores and infarct volumes, compared with the vehicle group. The increases in glial cell numbers and proinflammatory cytokine secretion usually caused by ischemia/reperfusion were significantly ameliorated by chrysin pretreatment. Moreover, chrysin also inhibited the MCAO-induced up-regulation of nuclear factor-kappa B (NF-?B), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS), compared with the vehicle. These results suggest that chrysin could be a potential prophylactic agent for cerebral ischemia/reperfusion (I/R) injury mediated by its anti-inflammatory and anti-oxidative effects.
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Physiological features of Halomonas lionensis sp. nov., a novel bacterium isolated from a Mediterranean Sea sediment.
Res. Microbiol.
PUBLISHED: 07-22-2014
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A novel halophilic bacterium, strain RHS90(T), was isolated from marine sediments from the Gulf of Lions, in the Mediterranean Sea. Its metabolic and physiological characteristics were examined under various cultural conditions, including exposure to stressful ones (oligotrophy, high pressure and high concentrations of metals). Based on phylogenetic analysis of the 16S rRNA gene, the strain was found to belong to the genus Halomonas in the class Gammaproteobacteria. Its closest relatives are Halomonas axialensis and Halomonas meridiana (98% similarity). DNA-DNA hybridizations indicated that the novel isolate is genotypically distinct from these species. The DNA G + C content of the strain is 54.4 mol%. The main fatty acids (C18:1?7c, 2-OH iso-C15:0, C16:0 and/or C19:0 cyclo ?8c), main polar lipids (diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and an unidentified phosphoglycolipid) and major respiratory quinone (ubiquinone Q9) were determined. The novel isolate is heterotrophic, mesophilic, euryhaline (growth optimum ranging from 2 to 8% w/v NaCl) and is able to grow under stressful conditions. The strain accumulates poly-?-hydroxyalkanoates granules and compatible solutes. Based on genotypic, chemotaxonomic and phenotypic distinctiveness, this isolate is likely to represent a novel species, for which the name Halomonas lionensis is proposed. The type strain of H. lionensis is RHS90(T) (DSM 25632(T) = CIP 110370(T) = UBOCC 3186(T)).
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Fingolimod for the treatment of intracerebral hemorrhage: a 2-arm proof-of-concept study.
JAMA Neurol
PUBLISHED: 07-09-2014
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Pronounced inflammatory reactions occurring shortly after intracerebral hemorrhage (ICH) contribute to the formation and progression of perihematomal edema (PHE) and secondary brain injury. We hypothesized that modulation of brain inflammation reduces edema, thus improving clinical outcomes in patients with ICH.
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Determining the organ of origin of large pelvic masses in females using multidetector CT angiography and three-dimensional volume rendering CT angiography.
Eur Radiol
PUBLISHED: 06-25-2014
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To study the value of tumour feeding arteries and the ovarian vein in determining the organ of origin of large pelvic tumours in females using multidetector CT.
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miR-125a-5p impairs endothelial cell angiogenesis in aging mice via RTEF-1 downregulation.
Aging Cell
PUBLISHED: 06-23-2014
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Increasing evidence suggests that microRNAs (miRNAs) play important roles in impaired endothelial cell (EC) angiogenesis during aging. However, their exact roles in the aging process remain unclear. We aimed to determine whether miRNAs cause angiogenesis defects in ECs during aging and to uncover the underlying mechanisms. To study the miRNA-induced changes in ECs during aging, we performed microarray analyses on arterial ECs collected from young and aging mice. Using qRT-PCR, we showed that microRNA-125a-5p (mir-125a-5p) expression was approximately 2.9 times higher in old endothelial cells (OECs) compared with samples collected from young animals. Western blot assays showed a lower expression level of an mir-125a-5p target known as related transcriptional enhancer factor-1 (RTEF-1) in OECs compared with its expression levels in young cells. Overexpression of mir-125a-5p in young endothelial cells (YECs) using pre-mir-125a-5p caused the downregulation of RTEF-1, endothelial nitric oxide synthase (eNOS) and vascular endothelial growth factor (VEGF) and resulted in impaired angiogenesis, as evidenced by spheroid sprouting and tube formation assays in vitro. Conversely, repression of mir-125a-5p in OECs using anti-mir-125a-5p increased RTEF-1, eNOS and VEGF expression and improved EC angiogenesis. Importantly, impaired angiogenesis caused by knock-down of RTEF-1 was not efficiently rescued by anti-mir-125a-5p. Dual-luciferase reporter gene analysis showed that RTEF-1 is a direct target of mir-125a-5p, which regulates angiogenesis by repressing RTEF-1 expression and modulating eNOS and VEGF expression. These findings indicate that mir-125a-5p and RTEF-1 are potential therapeutic targets for improving EC-mediated angiogenesis in elderly individuals.
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General incorporation of diverse components inside metal-organic framework thin films at room temperature.
Nat Commun
PUBLISHED: 06-16-2014
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Porous metal-organic frameworks (MOFs) demonstrate great potential for numerous applications. Although hetero-functional components have been encapsulated within MOF crystalline particles, the uniform incorporation of functional species with different sizes, shapes and functions in MOF thin films with dual properties, especially at room temperature and without the degradation of the MOF framework, remains a significant challenge towards further enriching their functions for various purposes. Here we report a general method that can rapidly encapsulate diverse functional components, including small ions, micrometre-sized particles, inorganic nanoparticles and bioactive proteins, in MOF thin films at room temperature via a metal-hydroxide-nanostrand-assisted confinement technique. These functional component-encapsulated MOF composite thin films exhibit synergistic and size-selective catalytic, bio-electrochemical, conductive and flexible functionalities that are desirable for thin film devices, including catalytic membrane reactors, biosensors and flexible electronic devices.
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Matrix softness regulates plasticity of tumour-repopulating cells via H3K9 demethylation and Sox2 expression.
Nat Commun
PUBLISHED: 06-06-2014
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Tumour-repopulating cells (TRCs) are a self-renewing, tumorigenic subpopulation of cancer cells critical in cancer progression. However, the underlying mechanisms of how TRCs maintain their self-renewing capability remain elusive. Here we show that relatively undifferentiated melanoma TRCs exhibit plasticity in Cdc42-mediated mechanical stiffening, histone 3 lysine residue 9 (H3K9) methylation, Sox2 expression and self-renewal capability. In contrast to differentiated melanoma cells, TRCs have a low level of H3K9 methylation that is unresponsive to matrix stiffness or applied forces. Silencing H3K9 methyltransferase G9a or SUV39h1 elevates the self-renewal capability of differentiated melanoma cells in a Sox2-dependent manner. Mechanistically, H3K9 methylation at the Sox2 promoter region inhibits Sox2 expression that is essential in maintaining self-renewal and tumorigenicity of TRCs both in vitro and in vivo. Taken together, our data suggest that 3D soft-fibrin-matrix-mediated cell softening, H3K9 demethylation and Sox2 gene expression are essential in regulating TRC self-renewal.
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Predictors for outcomes after super-selective mesenteric embolization for lower gastrointestinal tract bleeding.
ANZ J Surg
PUBLISHED: 05-31-2014
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The optimal management of bleeding from the lower gastrointestinal tract (LGIB) remains controversial. We aim to evaluate the efficacy of mesenteric embolization for LGIB and to identify predictors for re-bleeding after the procedure.
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Polymeric vector-mediated gene transfection of MSCs for dual bioluminescent and MRI tracking in vivo.
Biomaterials
PUBLISHED: 05-15-2014
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MSC's transplantation is a promising cell-based therapy for injuries in regenerative medicine, and in vivo visualization of transplanted MSCs with noninvasive technique is essential for the tracking of cell infusion and homing. A new cationic polymer, poly(ethylene glycol)-block-poly(l-aspartic acid)-grafted polyethylenimine functionalized with superparamagnetic iron oxide nanoparticles (PAI/SPION), was constructed as a magnetic resonance imaging (MRI)-visible non-viral vector for the delivery of plasmids DNA (pDNA) encoding for luciferase and red fluorescence protein (RFP) as reporter genes into MSCs. As a result, the MSCs were labeled with SPION and reporter genes. The PAI/SPION complexes exhibited high transfection efficiency in transferring pDNA into MSCs, which resulted in efficient luciferase and RFP co-expression. Furthermore, the complexes did not significantly affect the viability and multilineage differentiation capacity of MSCs. After the labeled MSCs were transplanted into the rats with acute liver injury via the superior mesenteric vein (SMV) injection, the migration behavior and organ-specific accumulation of the cells could be effectively monitored using the in vivo imaging system (IVIS) and MRI, respectively. The immunohistochemical analysis further confirmed that the transplanted MSCs were predominantly distributed in the liver parenchyma. Our results indicate that the PAI/SPION is a MRI-visible gene delivery agent which can effectively label MSCs to provide the basis for bimodal bioluminescence and MRI tracking in vivo.
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Rare earth element recycling from waste nickel-metal hydride batteries.
J. Hazard. Mater.
PUBLISHED: 05-05-2014
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With an increase in number of waste nickel-metal hydride batteries, and because of the importance of rare earth elements, the recycling of rare earth elements is becoming increasingly important. In this paper, we investigate the effects of temperature, hydrochloric acid concentration, and leaching time to optimize leaching conditions and determine leach kinetics. The results indicate that an increase in temperature, hydrochloric acid concentration, and leaching time enhance the leaching rate of rare earth elements. A maximum rare earth elements recovery of 95.16% was achieved at optimal leaching conditions of 70°C, solid/liquid ratio of 1:10, 20% hydrochloric acid concentration, -74?m particle size, and 100min leaching time. The experimental data were best fitted by a chemical reaction-controlled model. The activation energy was 43.98kJ/mol and the reaction order for hydrochloric acid concentration was 0.64. The kinetic equation for the leaching process was found to be: 1-(1-x)(1/3)=A/?r0[HCl](0.64)exp-439,8008.314Tt. After leaching and filtration, by adding saturated oxalic solution to the filtrate, rare earth element oxalates were obtained. After removing impurities by adding ammonia, filtering, washing with dilute hydrochloric acid, and calcining at 810°C, a final product of 99% pure rare earth oxides was obtained.
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Plumbagin suppresses dendritic cell functions and alleviates experimental autoimmune encephalomyelitis.
J. Neuroimmunol.
PUBLISHED: 05-05-2014
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Plumbagin (PL, 5-hydroxy-2-methyl-1,4-naphthoquinone) is a herbal compound derived from medicinal plants of the Droseraceae, Plumbaginaceae, Dioncophyllaceae, and Ancistrocladaceae families. Reports have shown that PL exerts immunomodulatory activity and may be a novel drug candidate for immune-related disease therapy. However, its effects on dendritic cells (DCs), the most potent antigen-presenting cells (APCs), remain unclear. In this study, we demonstrate that PL inhibits the differentiation, maturation, and function of human monocyte-derived DCs. PL can also restrict the expression of Th1- and Th17-polarizing cytokines in mDC. In addition, PL suppresses DCs both in vitro and in vivo, as demonstrated by its effects on the mouse DC line DC2.4 and mice with experimental autoimmune encephalomyelitis (EAE), respectively. Notably, PL ameliorated the clinical symptoms of EAE, including central nervous system (CNS) inflammation and demyelination. Our results demonstrate the immune suppressive and anti-inflammatory properties of PL via its effects on DCs and suggest that PL could be a potential treatment for DC-related autoimmune and inflammatory diseases.
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Generation of organized germ layers from a single mouse embryonic stem cell.
Nat Commun
PUBLISHED: 04-29-2014
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Mammalian inner cell mass cells undergo lineage-specific differentiation into germ layers of endoderm, mesoderm and ectoderm during gastrulation. It has been a long-standing challenge in developmental biology to replicate these organized germ layer patterns in culture. Here we present a method of generating organized germ layers from a single mouse embryonic stem cell cultured in a soft fibrin matrix. Spatial organization of germ layers is regulated by cortical tension of the colony, matrix dimensionality and softness, and cell-cell adhesion. Remarkably, anchorage of the embryoid colony from the 3D matrix to collagen-1-coated 2D substrates of ~1?kPa results in self-organization of all three germ layers: ectoderm on the outside layer, mesoderm in the middle and endoderm at the centre of the colony, reminiscent of generalized gastrulating chordate embryos. These results suggest that mechanical forces via cell-matrix and cell-cell interactions are crucial in spatial organization of germ layers during mammalian gastrulation. This new in vitro method could be used to gain insights on the mechanisms responsible for the regulation of germ layer formation.
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Controlled synthesis of porous platinum nanostructures for catalytic applications.
J Nanosci Nanotechnol
PUBLISHED: 04-23-2014
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Porous platinum, that has outstanding catalytic and electrical properties and superior resistant characteristics to corrosion, has been widely applied in chemical, petrochemical, pharmaceutical, electronic, and automotive industries. As the catalytic activity and selectivity depend on the size, shape and structure of nanomaterials, the strategies for controlling these factors of platinum nanomaterials to get excellent catalytic properties are discussed. Here, recent advances in the design and preparation of various porous platinum nanostructures are reviewed, including wet-chemical synthesis, electro-deposition, galvanic replacement reaction and de-alloying technology. The applications of various platinum nanostructures are also discussed, especially in fuel cells.
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A novel monoclonal antibody against the constant region of goose immunoglobulin light chain.
Monoclon Antib Immunodiagn Immunother
PUBLISHED: 04-22-2014
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A monoclonal antibody (MAb) against the antigenic determinant of the constant region of goose immunoglobulin light chain (GoIgCL) was produced and characterized for the first time here. Goose immunoglobulin (Ig) in serum was purified by immunoaffinity chromatography and the resulting protein was used as immunogen to immunize BALB/c mice. At the same time, the GoIgCL gene was expressed and purified as the screening antigen for selecting MAb against GoIgCL. One hybridoma that produces antibodies against GoIgCL was selected by indirect ELISA. Then the characterization of the MAb was analyzed by ELISA, Western blot, and flow cytometry. It was found to be IgG1 with ? light chain; the MAB has high specificity to Ig in goose serum, bile, and B lymphocytes from peripheral blood, reacts only with the light chain of goose Ig, and can distinguish Ig from other birds. Therefore, the MAb generated in this study can be used as a specific reagent for detection of goose disease-specific antibodies and as a powerful tool for basic immunology research on geese.
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Closing-opening wedge osteotomy for thoracolumbar traumatic kyphosis.
Eur. J. Med. Res.
PUBLISHED: 04-19-2014
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BackgroundSurgical treatment modalities for post-traumatic kyphosis (PTK) remain controversial. Like vertebral column resection, closing-opening wedge osteotomy (COWO) can achieve satisfactory results for kyphosis with multiple etiologies. However, few studies have assessed this procedure for PTK. Our purpose was to evaluate the radiographic and clinical outcomes of COWO in a selected series of patients with PTK via a single posterior approach.MethodsIn this retrospective case series, seven patients with symptomatic PTK in the thoracolumbar spine were reviewed. Five patients underwent surgery at the time of initial injury, and the other two initially underwent conservative treatment. All seven patients underwent COWO procedures through a single posterior approach. The Cobb angle was assessed preoperatively, postoperatively, and at the final follow-up. A visual analog scale (VAS) and the American Spinal Injury Association scale were used to evaluate back pain and neurological function preoperatively and at final follow-up, respectively. Operation-associated complications were also recorded.ResultsThe mean follow-up period was 34.3 months (range, 24 to 43 months). The mean kyphotic angle was significantly (P <0.05) reduced from 57.7° (range, 36° to 100°) preoperatively to 8° postoperatively (range, ¿12° to 50°). The mean VAS improved from 5.9 to 2.1 (P <0.05). Three patients exhibited improved neurological function. Bony fusion was achieved in all patients. No significant correction loss or permanent complication was noted.ConclusionsThough technically demanding, COWO via a single posterior approach can provide satisfactory outcomes for selected patients with PTK. Additional studies are required to improve patient selection and outcomes for this condition.
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Targeted silencing of anthrax toxin receptors protects against anthrax toxins.
J. Biol. Chem.
PUBLISHED: 04-17-2014
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Anthrax spores can be aerosolized and dispersed as a bioweapon. Current postexposure treatments are inadequate at later stages of infection, when high levels of anthrax toxins are present. Anthrax toxins enter cells via two identified anthrax toxin receptors: tumor endothelial marker 8 (TEM8) and capillary morphogenesis protein 2 (CMG2). We hypothesized that host cells would be protected from anthrax toxins if anthrax toxin receptor expression was effectively silenced using RNA interference (RNAi) technology. Thus, anthrax toxin receptors in mouse and human macrophages were silenced using targeted siRNAs or blocked with specific antibody prior to challenge with anthrax lethal toxin. Viability assays were used to assess protection in macrophages treated with specific siRNA or antibody as compared with untreated cells. Silencing CMG2 using targeted siRNAs provided almost complete protection against anthrax lethal toxin-induced cytotoxicity and death in murine and human macrophages. The same results were obtained by prebinding cells with specific antibody prior to treatment with anthrax lethal toxin. In addition, TEM8-targeted siRNAs also offered significant protection against lethal toxin in human macrophage-like cells. Furthermore, silencing CMG2, TEM8, or both receptors in combination was also protective against MEK2 cleavage by lethal toxin or adenylyl cyclase activity by edema toxin in human kidney cells. Thus, anthrax toxin receptor-targeted RNAi has the potential to be developed as a life-saving, postexposure therapy against anthrax.
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Development and evaluation of a competitive ELISA using a monoclonal antibody for antibody detection after goose parvovirus virus-like particles (VLPs) and vaccine immunization in goose sera.
J. Virol. Methods
PUBLISHED: 04-15-2014
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An assay protocol based on a monoclonal antibody-based competitive enzyme-linked immunosorbent assay (MAb-based C-ELISA) for detecting antibodies against goose parvovirus (GPV) and its virus-like particles (VLPs) is described. The assay was developed using baculovirus-expressed recombinant VP2 virus-like particles (rVP2-VLPs) as antigens and a monoclonal antibody against GPV as the competitive antibody. Of the four anti-GPV MAbs that were screened, MAb 1G3 was selected as it was blocked by the GPV positive serum. Based on the distribution of percent inhibition (PI) of the known negative sera (n=225), a cut-off value was set at 36% inhibition. Using this cut-off value, the sensitivity of the assay was 93.3% and the specificity was 95.8%, as compared with the gold standard (virus neutralization assay). The rVP2-VLPs did not react with anti-sera to other goose pathogens, indicating that it is specific for the recognization of goose parvovirus antibodies. The assay was then validated with serum samples from goslings vaccinated with several VLPs (rVP1-VLPs, rVP2-VLPs, rVP3-VLPs, and rCGV-VLPs) and other vaccines (inactivated and attenuated). The C-ELISA described in this study is a sensitive and specific diagnostic test and should have wide applications for the sero-diagnosis and immunologic surveillance of GPV.
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Hepatocellular carcinoma with portal vein tumor thrombus: treatment with transarterial chemoembolization combined with sorafenib--a retrospective controlled study.
Radiology
PUBLISHED: 04-06-2014
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To determine the safety and efficacy of transarterial chemoembolization (TACE) combined with sorafenib (hereafter, TACE-sorafenib) in patients with hepatocellular carcinoma (HCC) and portal vein tumor thrombus (PVTT).
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A new algorithm for calculating optimal viewing angles in coronary angiography based on 4-D cardiac computed tomography.
J Xray Sci Technol
PUBLISHED: 04-05-2014
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Coronary stenosis is the main cause of the coronary heart disease (CHD). However, coronary arteriography (CAG), which is considered as the 'gold standard' of determining the location and severity of CHD, hardly acquires a satisfactory image for some lesions by traditional viewing angles.
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Encoding brain network response to free viewing of videos.
Cogn Neurodyn
PUBLISHED: 04-02-2014
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A challenging goal for cognitive neuroscience researchers is to determine how mental representations are mapped onto the patterns of neural activity. To address this problem, functional magnetic resonance imaging (fMRI) researchers have developed a large number of encoding and decoding methods. However, previous studies typically used rather limited stimuli representation, like semantic labels and Wavelet Gabor filters, and largely focused on voxel-based brain patterns. Here, we present a new fMRI encoding model to predict the human brain's responses to free viewing of video clips which aims to deal with this limitation. In this model, we represent the stimuli using a variety of representative visual features in the computer vision community, which can describe the global color distribution, local shape and spatial information and motion information contained in videos, and apply the functional connectivity to model the brain's activity pattern evoked by these video clips. Our experimental results demonstrate that brain network responses during free viewing of videos can be robustly and accurately predicted across subjects by using visual features. Our study suggests the feasibility of exploring cognitive neuroscience studies by computational image/video analysis and provides a novel concept of using the brain encoding as a test-bed for evaluating visual feature extraction.
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Exploring the Solid State Properties of Enzymatic Poly(amine-co-ester) Terpolymers to Expand their Applications in Gene Transfection.
RSC Adv
PUBLISHED: 04-01-2014
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Polymers bearing amino functional groups are an important class of materials capable of serving as non-viral carriers for DNA delivery to living cells. In this work biodegradable poly(amine-co-ester) terpolymers were synthesized via ring-opening and polycondensation copolymerization of lactone (?-caprolactone (CL), ?-dodecalactone, ?-pentadecalactone (PDL), and ?-hexadecalactone) with diethyl sebacate (DES) and N-methyldiethanolamine (MDEA) in diphenyl ether, catalyzed by Candida antarctica lipase B (CALB). All lactone-DES-MDEA terpolymers had random distributions of lactone, sebacate, MDEA repeat units in the polymer chains. PDL-DES-MDEA terpolymers were studied in the composition range from 21 mol% to 90 mol% PDL whereas the terpolymers with other lactones were investigated at a single composition (80 mol% lactone). DSC and WAXS analyses showed that all investigated terpolymers crystallize in their respective homopolylactone crystal lattice. Terpolymers with large lactones and a high lactone content melt well above room temperature and are hard solids, whereas terpolymers with small lactones (e.g. CL) or with a low lactone content melt below/around ambient temperature and are waxy/gluey materials. Given the importance of hydrophobicity in influencing gene delivery, water contact angle measurements were carried out on lactone-DES-MDEA terpolymers showing that it is possible to tune the hydrophilic-to-hydrophobic balance by varying polymer composition and size of lactone units. To demonstrate the feasibility of using solid terpolymers as nanocarriers for DNA delivery, PDL-DES-MDEA copolymers with 65-90% PDL were successfully transformed into free-standing nanoparticles with average particle size ranging from 163 to 175 nm. Our preliminary results showed that LucDNA-loaded nanoparticles of the terpolymer with 65% PDL were effective for luciferase gene transfection of HEK293 cells.
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Hybrid daylight/light-emitting diode illumination system for indoor lighting.
Appl Opt
PUBLISHED: 03-26-2014
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A hybrid illumination method using both daylight and light-emitting diodes (LEDs) for indoor lighting is presented in this study. The daylight can be introduced into the indoor space by a panel-integration system. The daylight part and LEDs are combined within a specific luminaire that can provide uniform illumination. The LEDs can be turned on and dimmed through closed-loop control when the daylight illuminance is inadequate. We simulated the illumination and calculated the indoor lighting efficiency of our hybrid daylight and LED lighting system, and compared this with that of LED and fluorescent lighting systems. Simulation results show that the efficiency of the hybrid daylight/LED illumination method is better than that of LED and traditional lighting systems, under the same lighting conditions and lighting time; the method has hybrid lighting average energy savings of T5 66.28%, and that of the LEDs is 41.62%.
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The effect of hyperbranched polyglycerol coatings on drug delivery using degradable polymer nanoparticles.
Biomaterials
PUBLISHED: 03-25-2014
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A key attribute for nanoparticles (NPs) that are used in medicine is the ability to avoid rapid uptake by phagocytic cells in the liver and other tissues. Poly(ethylene glycol) (PEG) coatings has been the gold standard in this regard for several decades. Here, we examined hyperbranched polyglycerols (HPG) as an alternate coating on NPs. In earlier work, HPG was modified with amines and subsequently conjugated to poly(lactic acid) (PLA), but that approach compromised the ability of HPG to resist non-specific adsorption of biomolecules. Instead, we synthesized a copolymer of PLA-HPG by a one-step esterification. NPs were produced from a single emulsion using PLA-HPG: fluorescent dye or the anti-tumor agent camptothecin (CPT) were encapsulated at high efficiency in the NPs. PLA-HPG NPs were quantitatively compared to PLA-PEG NPs, produced using approaches that have been extensively optimized for drug delivery in humans. Despite being similar in size, drug release profile and in vitro cytotoxicity, the PLA-HPG NPs showed significantly longer blood circulation and significantly less liver accumulation than PLA-PEG. CPT-loaded PLA-HPG NPs showed higher stability in suspension and better therapeutic effectiveness against tumors in vivo than CPT-loaded PLA-PEG NPs. Our results suggest that HPG is superior to PEG as a surface coating for NPs in drug delivery.
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Mapping of hepatic expression quantitative trait loci (eQTLs) in a Han Chinese population.
J. Med. Genet.
PUBLISHED: 03-24-2014
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Elucidating the genetic basis underlying hepatic gene expression variability is of importance to understand the aetiology of the disease and variation in drug metabolism. To date, no genome-wide expression quantitative trait loci (eQTLs) analysis has been conducted in the Han Chinese population, the largest ethnic group in the world.
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Optimized production of a novel bioflocculant M-C11 by Klebsiella sp. and its application in sludge dewatering.
J Environ Sci (China)
PUBLISHED: 03-21-2014
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The optimized production of a novel bioflocculant M-C11 produced by Klebsiella sp. and its application in sludge dewatering were investigated. The optimal medium carbon source, nitrogen source, metal ion, initial pH and culture temperature for the bioflocculant production were glucose, NaNO3, MgSO4, and pH7.0 and 25°C, respectively. A compositional analysis indicated that the purified M-C11 consisted of 91.2% sugar, 4.6% protein and 3.9% nucleic acids (m/m). A Fourier transform infrared spectrum confirmed the presence of carboxyl, hydroxyl, methoxyl and amino groups. The microbial flocculant exhibited excellent pH and thermal stability in a kaolin suspension over a pH range of 4.0 to 8.0 and a temperature range of 20 to 60°C. The optimum bioflocculating activity was observed as 92.37% for 2.56mL M-C11 and 0.37g/L CaCl2 dosages using response surface methodology. The sludge resistance in filtration (SRF) decreased from 11.6×10(12) to 4.7×10(12)m/kg, which indicated that the sludge dewaterability was remarkably enhanced by the bioflocculant conditioning. The sludge dewatering performance conditioned by M-C11 was more efficient than that of inorganic flocculating reagents, such as aluminum sulfate and polymeric aluminum chloride. The bioflocculant has advantages over traditional sludge conditioners due to its lower cost, benign biodegradability and negligible secondary pollution. In addition, the bioflocculant was favorably adapted to the specific sludge pH and salinity.
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Intranasal immunization with influenza antigens conjugated with cholera toxin subunit B stimulates broad spectrum immunity against influenza viruses.
Hum Vaccin Immunother
PUBLISHED: 03-14-2014
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Frequent mutation of influenza viruses keep vaccinated and non-vaccinated populations vulnerable to new infections, causing serious burdens to public health and the economy. Vaccination with universal influenza vaccines would be the best way to effectively protect people from infection caused by mismatched or unforeseen influenza viruses. Presently, there is no FDA approved universal influenza vaccine. In this study, we expressed and purified a fusion protein comprising of influenza matrix 2 protein ectodomain peptides, a centralized influenza hemagglutinin stem region, and cholera toxin subunit B. Vaccination of BALB/c mice with this novel artificial antigen resulted in potent humoral immune responses, including induction of specific IgA and IgG, and broad protection against infection by multiple influenza viruses. Furthermore, our results demonstrated that when used as a mucosal antigen, cholera toxin subunit B improved antigen-stimulated T cell and memory B cell responses.
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Pressure-assisted synthesis of HKUST-1 thin film on polymer hollow fiber at room temperature toward gas separation.
ACS Appl Mater Interfaces
PUBLISHED: 03-14-2014
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The scalable fabrication of continuous and defect-free metal-organic framework (MOF) films on the surface of polymeric hollow fibers, departing from ceramic supported or dense composite membranes, is a huge challenge. The critical way is to reduce the growth temperature of MOFs in aqueous or ethanol solvents. In the present work, a pressure-assisted room temperature growth strategy was carried out to fabricate continuous and well-intergrown HKUST-1 films on a polymer hollow fiber by using solid copper hydroxide nanostrands as the copper source within 40 min. These HKUST-1 films/polyvinylidenefluoride (PVDF) hollow fiber composite membranes exhibit good separation performance for binary gases with selectivity 116% higher than Knudsen values via both inside-out and outside-in modes. This provides a new way to enable for scale-up preparation of HKUST-1/polymer hollow fiber membranes, due to its superior economic and ecological advantages.
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Pwp1 Is Required for the Differentiation Potential of Mouse Embryonic Stem Cells through Regulating Stat3 Signaling.
Stem Cells
PUBLISHED: 03-13-2014
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LIF/Stat3 signaling is critical for maintaining the self-renewal and differentiation potential of mouse embryonic stem cells (mES cells). However, the upstream effectors of this pathway have not been clearly defined. Here, we show that periodic tryptophan protein 1 (Pwp1), a WD-40 repeat-containing protein associated with histone H4 modification, is required for the exit of mES cells from the pluripotent state into all lineages. Knockdown of Pwp1 does not affect mES cell proliferation, self-renewal or apoptosis. However, knockdown of Pwp1 impairs the differentiation potential of mES cells both in vitro and in vivo. PWP1 ChIP-seq results revealed that the PWP1-occupied regions were marked with significant levels of H4K20me3. Moreover, Pwp1 binds to sites in the upstream region of Stat3. Knockdown of Pwp1 decreases the level of H4K20me3 in the upstream region of Stat3 gene and upregulates the expression of Stat3. Furthermore, Pwp1 knockdown (KD) mES cells recover their differentiation potential through suppressing the expression of Stat3 or inhibiting the tyrosine phosphorylation of STAT3. Together, our results suggest that Pwp1 plays important roles in the differentiation potential of mES cells. Stem Cells 2014.
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Pseudopedobacter beijingensis gen. nov., sp. nov., isolated from coking wastewater activated sludge, and reclassification of Pedobacter saltans as Pseudopedobacter saltans comb. nov.
Int. J. Syst. Evol. Microbiol.
PUBLISHED: 02-26-2014
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A taxonomic study was carried out on strain GCS-AE-31(T), which was isolated from a phenol-degrading consortium, enriched from coking wastewater activated sludge of the Beijing Shougang Company Limited during the screening of phenol-degrading bacteria. Cells of strain GCS-AE-31(T) were Gram-stain-negative, short rods, motile by gliding, oxidase- and catalase-positive. Growth was observed at salinities of 0-3% and at temperatures of 10-37 °C. On the basis of 16S rRNA gene sequence similarity, strain GCS-AE-31(T) was most closely related to Pedobacter saltans LMG 10337(T) (96.17%), but it showed low similarity to all other species of the genus Pedobacter (89.28-92.45%). It also showed low 16S rRNA gene similarity to all other species of the family Sphingobacteriaceae (87.25-92.45%) examined. The dominant fatty acids were iso-C(15?:?0), summed feature 3 (C(16?:?1)?7c/C(16?:?1)?6c), anteiso-C(15?:?0) and iso-C(17?:?0) 3-OH. The menaquinones were MK-7 (95.5%) and MK-6 (4.5%). The polar lipids were phosphatidylethanolamine, three aminolipids and three unknown phospholipids. Sphingolipid was present. The G+C content of the chromosomal DNA was 36.2 mol%. According to its phylogenetic position and phenotypic traits, the novel strain could not be assigned to the genus Pedobacter; it should be classified as representing a novel species of a novel genus in the family Sphingobacteriaceae, for which the name Pseudopedobacter beijingensis gen. nov., sp. nov. is proposed (type strain GCS-AE-31(T)?=?MCCC 1A01299(T)?=?CGMCC 1.12329(T)?=?LMG 27180(T)). The misclassified species Pedobacter saltans is transferred to the novel genus as Pseudopedobacter saltans comb. nov. (type strain LMG 10337(T)?=?MCCC 1A06472(T)?=?DSM 12145(T)?=?CCUG 39354(T)?=?CIP 105500(T)?=?JCM 21818(T)?=?NBRC 100064(T)).
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Co@Co?O? core-shell three-dimensional nano-network for high-performance electrochemical energy storage.
Small
PUBLISHED: 02-23-2014
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An alternative routine is presented by constructing a novel architecture, conductive metal/transition oxide (Co@Co3O4) core-shell three-dimensional nano-network (3DN) by surface oxidating Co 3DN in situ, for high-performance electrochemical capacitors. It is found that the Co@Co3O4 core-shell 3DN consists of petal-like nanosheets with thickness of <10 nm interconnected forming a 3D porous nanostructure, which preserves the original morphology of Co 3DN well. X-ray photoelectron spectroscopy by polishing the specimen layer by layer reveals that the Co@Co3O4 nano-network is core-shell-like structure. In the application of electrochemical capacitors, the electrodes exhibit a high specific capacitance of 1049 F g(-1) at scan rate of 2 mV/s with capacitance retention of ~52.05% (546 F g(-1) at scan rate of 100 mV) and relative high areal mass density of 850 F g(-1) at areal mass of 3.52 mg/cm(2). It is believed that the good electrochemical behaviors mainly originate from its extremely high specific surface area and underneath core-Co "conductive network". The high specific surface area enables more electroactive sites for efficient Faradaic redox reactions and thus enhances ion and electron diffusion. The underneath core-Co "conductive network" enables an ultrafast electron transport.
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Soil microbial systems respond differentially to tetracycline, sulfamonomethoxine, and ciprofloxacin entering soil under pot experimental conditions alone and in combination.
Environ Sci Pollut Res Int
PUBLISHED: 02-19-2014
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This study investigated soil microbial responses to the application of tetracycline (TC), sulfamonomethoxine (SMM), and ciprofloxacin (CIP) alone and in combination in a soil culture pot experiment conducted at Hangzhou, China. Multiple approaches were applied for a better and complete depiction. Among the three antibiotics, SMM has a lowest dissipation and shows a most dramatic inhibition on microbial community and metabolism diversity. The combined application (AM) of SMM, CIP, and TC improved the dissipation of each antibiotic; similarly, SMM- and CIP-resistant bacteria showed larger populations in the AM than all single applications. Soils accumulated a large content of NO3-N at day 20 after multi-antibiotics perturbation. All antibiotics stimulated soil basal respirations and inhibited soil metabolism diversity, whereas the interruption exerted by SMM and AM lasted for a longer time. Six nitrogen-cycling genes including chiA, amoA, nifH, nirK, nirS, and narG were quantified and found to decrease owing to both single- and multi-antibiotics perturbation. Overall, AM was most interruptive for soils, followed by SMM perturbation, while other antibiotics could be less interruptive. These results provide systematic insights into how soil microbial systems would shift under each single- or multi-antibiotics perturbation.
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Effects of combined application of organic and inorganic fertilizers plus nitrification inhibitor DMPP on nitrogen runoff loss in vegetable soils.
Environ Sci Pollut Res Int
PUBLISHED: 02-18-2014
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The application of nitrogen fertilizers leads to various ecological problems such as large amounts of nitrogen runoff loss causing water body eutrophication. The proposal that nitrification inhibitors could be used as nitrogen runoff loss retardants has been suggested in many countries. In this study, simulated artificial rainfall was used to illustrate the effect of the nitrification inhibitor DMPP (3,4-dimethyl pyrazole phosphate) on nitrogen loss from vegetable fields under combined organic and inorganic nitrogen fertilizer application. The results showed that during the three-time simulated artificial rainfall period, the ammonium nitrogen content in the surface runoff water collected from the DMPP application treatment increased by 1.05, 1.13, and 1.10 times compared to regular organic and inorganic combined fertilization treatment, respectively. In the organic and inorganic combined fertilization with DMPP addition treatment, the nitrate nitrogen content decreased by 38.8, 43.0, and 30.1 % in the three simulated artificial rainfall runoff water, respectively. Besides, the nitrite nitrogen content decreased by 95.4, 96.7, and 94.1 % in the three-time simulated artificial rainfall runoff water, respectively. A robust decline in the nitrate and nitrite nitrogen surface runoff loss could be observed in the treatments after the DMPP addition. The nitrite nitrogen in DMPP addition treatment exhibited a significant low level, which is near to the no fertilizer application treatment. Compared to only organic and inorganic combined fertilizer treatment, the total inorganic nitrogen runoff loss declined by 22.0 to 45.3 % in the organic and inorganic combined fertilizers with DMPP addition treatment. Therefore, DMPP could be used as an effective nitrification inhibitor to control the soil ammonium oxidation in agriculture and decline the nitrogen runoff loss, minimizing the nitrogen transformation risk to the water body and being beneficial for the ecological environment.
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Molecular characterization and B cell membrane expression analysis of Fc fragment gene of goose IgY.
Res. Vet. Sci.
PUBLISHED: 02-15-2014
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A novel goose immunoglobulin ? chain (Ig?) Fc fragment gene was cloned from splenic tissue mRNA using RT-PCR. Deduced amino acid sequence data from different vertebrates revealed high similarity to IgY-Fc fragments of duck (91%) and chicken (64%). Molecular characterization showed that the goose IgY-Fc fragment was consistent with the definition of immunoglobulin, and had the same antigenicity to natural IgY. Flow cytometry and laser scanning confocal microscopy showed that the polyclonal antibody against Go?Fc reacted with the membrane surface of B lymphocytes in peripheral blood, which indicates that IgY was expressed on the surface of B cells. Analyses of the gene sequence of the goose IgY-Fc fragment and expression of B cell membrane may provide insight into the evolution of the Ig heavy chain gene family and benefit future studies on the avian immune system.
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Camelid genomes reveal evolution and adaptation to desert environments.
Nat Commun
PUBLISHED: 02-06-2014
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Bactrian camel (Camelus bactrianus), dromedary (Camelus dromedarius) and alpaca (Vicugna pacos) are economically important livestock. Although the Bactrian camel and dromedary are large, typically arid-desert-adapted mammals, alpacas are adapted to plateaus. Here we present high-quality genome sequences of these three species. Our analysis reveals the demographic history of these species since the Tortonian Stage of the Miocene and uncovers a striking correlation between large fluctuations in population size and geological time boundaries. Comparative genomic analysis reveals complex features related to desert adaptations, including fat and water metabolism, stress responses to heat, aridity, intense ultraviolet radiation and choking dust. Transcriptomic analysis of Bactrian camels further reveals unique osmoregulation, osmoprotection and compensatory mechanisms for water reservation underpinned by high blood glucose levels. We hypothesize that these physiological mechanisms represent kidney evolutionary adaptations to the desert environment. This study advances our understanding of camelid evolution and the adaptation of camels to arid-desert environments.
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A linear model for characterization of synchronization frequencies of neural networks.
Cogn Neurodyn
PUBLISHED: 01-28-2014
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The synchronization frequency of neural networks and its dynamics have important roles in deciphering the working mechanisms of the brain. It has been widely recognized that the properties of functional network synchronization and its dynamics are jointly determined by network topology, network connection strength, i.e., the connection strength of different edges in the network, and external input signals, among other factors. However, mathematical and computational characterization of the relationships between network synchronization frequency and these three important factors are still lacking. This paper presents a novel computational simulation framework to quantitatively characterize the relationships between neural network synchronization frequency and network attributes and input signals. Specifically, we constructed a series of neural networks including simulated small-world networks, real functional working memory network derived from functional magnetic resonance imaging, and real large-scale structural brain networks derived from diffusion tensor imaging, and performed synchronization simulations on these networks via the Izhikevich neuron spiking model. Our experiments demonstrate that both of the network synchronization strength and synchronization frequency change according to the combination of input signal frequency and network self-synchronization frequency. In particular, our extensive experiments show that the network synchronization frequency can be represented via a linear combination of the network self-synchronization frequency and the input signal frequency. This finding could be attributed to an intrinsically-preserved principle in different types of neural systems, offering novel insights into the working mechanism of neural systems.
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A novel biophysical model on calcium and voltage dual dependent gating of calcium-activated chloride channel.
J. Theor. Biol.
PUBLISHED: 01-21-2014
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Ca(2+)-activated Cl(-) channels (CaCCs) are anion-selective channels and involved in physiological processes such as electrolyte/fluid secretion, smooth muscle excitability, and olfactory perception which critically depend on the Ca(2+) and voltage dual-dependent gating of channels. However, how the Ca(2+) and voltage regulate the gating of CaCCs still unclear. In this work, the authors constructed a biophysical model to illustrate the dual-dependent gating of CaCCs. For validation, we applied our model on both native CaCCs and exogenous TMEM16A which is thought to be the molecular basis of CaCCs. Our data show that the native CaCCs may share universal gating mechanism. We confirmed the assumption that by binding with the channel, Ca(2+) decreases the energy-barrier to open the channel, but not changes the voltage-sensitivity. For TMEM16A, our model indicates that the exogenous channels show different Ca(2+) dependent gating mechanism from the native ones. These results advance the understanding of intracellular Ca(2+) and membrane potential regulation in CaCCs, and shed new light on its function in aspect of physiology and pharmacology.
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Determination of amitraz and its metabolites in whole blood using solid-phase extraction and liquid chromatography-tandem mass spectrometry.
J. Chromatogr. B Analyt. Technol. Biomed. Life Sci.
PUBLISHED: 01-20-2014
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A method was developed for determination of amitraz and its metabolites, N-[2,4-(dimethylphenyl)-N'-methylformamidine (DMPF), 2,4-dimethylformamidine (DMF), 2,4-dimethylaniline (DMA) in whole blood. The analytes were extracted by solid-phase extraction (SPE) using dichloromethane, acetonitrile and methanol (2:1:1) mixture as elute solution. Analysis was performed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in the positive ion mode using multiple reaction monitoring (MRM) technique. Collision-induced dissociation (CID) of amitraz at the electrospray source in MS/MS was observed in the analytic conditions. The method was validated in human whole blood spiked at three concentration levels. The low limit of detection (LOD) and the low limit of quantification (LOQ) for all the analytes were below 0.5?g/L and 2?g/L, respectively. Recoveries were between 90.2% and 104.5%, Bias and relative standard deviation (RSD) were below 15% (n=6). The good linear relationships were obtained in certain concentration ranges of amitraz and its metabolites. The results demonstrated the method is exclusive, sensitive and accurate, and can be applied in forensic toxicology.
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Influence of TLR4 rs1927907 locus polymorphisms on tacrolimus pharmacokinetics in the early stage after liver transplantation.
Eur. J. Clin. Pharmacol.
PUBLISHED: 01-18-2014
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The aim of this study was to assess the potential influence of single nucleotide polymorphisms (SNPs) in the TLR4 gene on tacrolimus pharmacokinetics in the early stage after liver transplantation.
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An adaptive 6-DOF tracking method by hybrid sensing for ultrasonic endoscopes.
Sensors (Basel)
PUBLISHED: 01-17-2014
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In this paper, a novel hybrid sensing method for tracking an ultrasonic endoscope within the gastrointestinal (GI) track is presented, and the prototype of the tracking system is also developed. We implement 6-DOF localization by sensing integration and information fusion. On the hardware level, a tri-axis gyroscope and accelerometer, and a magnetic angular rate and gravity (MARG) sensor array are attached at the end of endoscopes, and three symmetric cylindrical coils are placed around patients' abdomens. On the algorithm level, an adaptive fast quaternion convergence (AFQC) algorithm is introduced to determine the orientation by fusing inertial/magnetic measurements, in which the effects of magnetic disturbance and acceleration are estimated to gain an adaptive convergence output. A simplified electro-magnetic tracking (SEMT) algorithm for dimensional position is also implemented, which can easily integrate the AFQC's results and magnetic measurements. Subsequently, the average position error is under 0.3 cm by reasonable setting, and the average orientation error is 1° without noise. If magnetic disturbance or acceleration exists, the average orientation error can be controlled to less than 3.5°.
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Ottowia beijingensis sp. nov., isolated from coking wastewater activated sludge, and emended description of the genus Ottowia.
Int. J. Syst. Evol. Microbiol.
PUBLISHED: 01-16-2014
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A taxonomic study was carried out on strain GCS-AN-3(T), which was isolated from a phenol-degrading consortium enriched from coking wastewater activated sludge of Beijing Shougang Company Limited during the screening of phenol-degrading bacteria. Cells of strain GCS-AN-3(T) were Gram-stain-negative, short rods, and oxidase-/catalase-positive. Growth was observed at salinities from 0 to 2.5?% and at temperatures from 10 to 37 °C. 16S rRNA gene sequence analysis showed that strain GCS-AN-3(T) was most closely related to Ottowia pentelensis DSM 21699(T) (96.2?%). The principal fatty acids were summed feature 3 (C16?:?1?7c/C16?:?1?6c), C16?:?0, summed feature 8 (C18?:?1?7c/C18?:?1?6c) and cyclo C17?:?0. The major respiratory quinone was Q-8. The polar lipids comprised phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine and an unknown phospholipid. The G+C content of the genomic DNA was 67.6 mol%. Thiosulfate could be utilized as co-substrate for aerobic growth and was oxidized to sulfate. On the basis of phenotypic, chemotaxonomic and molecular data, strain GCS-AN-3(T) is considered to represent a novel species of the genus Ottowia, for which the name Ottowia beijingensis sp. nov. is proposed (type strain GCS-AN-3(T)?=?LMG 27179(T)?=?CGMCC 1.12324(T)?=?MCCC 1A01410(T)). An emended description of the genus Ottowia is also proposed.
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Addition of poly (propylene glycol) to multiblock copolymer to optimize siRNA delivery.
Bioengineered
PUBLISHED: 01-16-2014
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Previous studies have examined different strategies for siRNA delivery with varying degrees of success. These include use of viral vectors, cationic liposomes, and polymers. Several copolymers were designed and synthesized based on blocks of poly(ethylene glycol) PEG, poly(propylene glycol) PPG, and poly(l-lysine). These were designated as P1, P2, and P3. We studied the copolymer self-assembly, siRNA binding, particle size, surface potential, architecture of the complexes, and siRNA delivery. Silencing of GFP using copolymer P3 to deliver GFP-specific siRNA to Neuro-2a cells expressing GFP was almost as effective as using Lipofectamine 2000, with minimal cytotoxicity. Thus, we have provided a new copolymer platform for siRNA delivery that we can continue to modify for improved delivery of siRNA in vitro and eventually in vivo.
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The chloroplast view of the evolution of polyploid wheat.
New Phytol.
PUBLISHED: 01-10-2014
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Polyploid wheats comprise four species: Triticum turgidum (AABB genomes) and T. aestivum (AABBDD) in the Emmer lineage, and T. timopheevii (AAGG) and T. zhukovskyi (AAGGA(m) A(m) ) in the Timopheevi lineage. Genetic relationships between chloroplast genomes were studied to trace the evolutionary history of the species. Twenty-five chloroplast genomes were sequenced, and 1127 plant accessions were genotyped, representing 13 Triticum and Aegilops species. The A. speltoides (SS genome) diverged before the divergence of T. urartu (AA), A. tauschii (DD) and the Aegilops species of the Sitopsis section. Aegilops speltoides forms a monophyletic clade with the polyploid Emmer and Timopheevi wheats, which originated within the last 0.7 and 0.4 Myr, respectively. The geographic distribution of chloroplast haplotypes of the wild tetraploid wheats and A. speltoides illustrates the possible geographic origin of the Emmer lineage in the southern Levant and the Timopheevi lineage in northern Iraq. Aegilops speltoides is the closest relative of the diploid donor of the chloroplast (cytoplasm), as well as the B and G genomes to Timopheevi and Emmer lineages. Chloroplast haplotypes were often shared by species or subspecies within major lineages and between the lineages, indicating the contribution of introgression to the evolution and domestication of polyploid wheats.
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Cytoplasmic effects on DNA methylation between male sterile lines and the maintainer in wheat (Triticum aestivum L.).
Gene
PUBLISHED: 01-04-2014
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Male sterile cytoplasm plays an important role in hybrid wheat, and three-line system including male sterile (A line), its maintainer (B line) and restoring (R line) has played a major role in wheat hybrid production. It is well known that DNA methylation plays an important role in gene expression regulation during biological development in wheat. However, no reports are available on DNA methylation affected by different male sterile cytoplasms in hybrid wheat. We employed a methylation-sensitive amplified polymorphism technique to characterize nuclear DNA methylation in three male sterile cytoplasms. A and B lines share the same nucleus, but have different cytoplasms which is male sterile for the A and fertile for the B. The results revealed a relationship of DNA methylation at these sites specifically with male sterile cytoplasms, as well as male sterility, since the only difference between the A lines and B line was the cytoplasm. The DNA methylation was markedly affected by male sterile cytoplasms. K-type cytoplasm affected the methylation to a much greater degree than T-type and S-type cytoplasms, as indicated by the ratio of methylated sites, ratio of fully methylated sites, and polymorphism between A lines and B line for these cytoplasms. The genetic distance between the cytoplasm and nucleus for the K-type is much greater than for the T- and S-types because the former is between Aegilops genus and Triticum genus and the latter is within Triticum genus between Triticum spelta and Triticum timopheevii species. Thus, this difference in genetic distance may be responsible for the variation in methylation that we observed.
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Mild degenerative changes of hip cartilage in elderly patients: an available sample representative of early osteoarthritis.
Int J Clin Exp Pathol
PUBLISHED: 01-01-2014
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This study investigated the cellular and molecular changes which occur in cartilage from adults with femoral neck fracture (FNF) and osteoarthritis (OA), and explored the similarities in hip cartilage obtained from elderly patients and patients with early OA. Femoral heads were retrieved from 23 female patients undergoing total hip arthroplasty (THA). This group included 7 healthy patients with FNF (hFNF), 8 elderly adults with FNF (eFNF), and 8 elderly patients with hip OA (OA). After high-field MRI T2 mapping, osteochondral plugs were harvested from the weight-bearing area of femoral heads for subsequent macroscopic, histologic, and immunochemical evaluation. Additionally, the contents of cartilage matrix were analyzed, and gene expression was detected. The surface of cartilage from hFNF and eFNF patients appeared smooth, regular, and elastic, whereas it showed irregularities, thinning, and defects in OA patients. Elevated T2 values and decreased accumulation of glycosaminoglycans (GAGs) were detected in cartilage from eFNF patients. Furthermore, type I collagen accumulation was slightly increased and type X collagen concentration was obviously elevated in eFNF patients; however, type II collagen distribution and the contents and anisotropy of collagen fibrils in eFNF patients showed no significant changes. Consistent with histology and immunohistochemical results, aggrecan was downregulated and type X collagen was upregulated, while collagens types I and II showed no significant changes in eFNF patients. The cellular and molecular characteristics of hip cartilage in eFNF patients who showed no symptoms of OA were similar to those in patients with mild OA. Thus, eFNF cartilage can serve as a comparative specimen for use in studies investigating early OA.
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Overexpression of eIF3e is correlated with colon tumor development and poor prognosis.
Int J Clin Exp Pathol
PUBLISHED: 01-01-2014
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EIF3e is a component of the eukaryotic translation initiation factor 3 (eIF-3) complexes, which is an essential factor for initiation of protein synthesis in mammalian cells. Translational control plays key roles in the complex mechanism of cancer development and progression. However, the clinical significance of eIF3e in colon cancer remains to be elucidated. We analyzed the eIF3e expression in a tissue microarray (TMA), which contained 173 colon cancer tissues paired with adjacent normal mucosa and lymph node metastasis. The expression of eIF3e was significantly elevated in colon cancer tissues in comparison with those in adjacent normal mucosa (P < 0.001) and lymph node metastasis (P < 0.001). The high expression of eIF3e in colon cancer was significantly correlated with tumor size (P < 0.001), lymph node involvement (P < 0.001), distant metastasis (P < 0.001), clinical stage (P < 0.001), histopathologic classification (P < 0.001), and vessel invasion (P = 0.036). Univariate and multivariate analysis revealed that eIF3e is an independent prognosis factor for overall survival and disease-free survival in colon cancer. Down-regulation of eIF3e in vitro inhibited colon cancer cell proliferation, clonality and promoted cell apoptosis. Taken together, high eIF3e expression may contribute to tumor progression and predict poor prognosis in colon cancer.
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Lack of negatively charged residues at the external mouth of kir2.2 channels enable the voltage-dependent block by external mg2+.
PLoS ONE
PUBLISHED: 01-01-2014
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Kir channels display voltage-dependent block by cytosolic cations such as Mg2+ and polyamines that causes inward rectification. In fact, cations can regulate K channel activity from both the extracellular and intracellular sides. Previous studies have provided insight into the up-regulation of Kir channel activity by extracellular K+ concentration. In contrast, extracellular Mg2+ has been found to reduce the amplitude of the single-channel current at milimolar concentrations. However, little is known about the molecular mechanism of Kir channel blockade by external Mg2+ and the relationship between the Mg2+ blockade and activity potentiation by permeant K+ ions. In this study, we applied an interactive approach between theory and experiment. Electrophysiological recordings on Kir2.2 and its mutants were performed by heterologous expression in Xenopus laevis oocytes. Our results confirmed that extracellular Mg2+ could reduce heterologously expressed WT Kir2.2 currents in a voltage dependent manner. The kinetics of inhibition and recovery of Mg2+ exhibit a 3?4s time constant. Molecular dynamics simulation results revealed a Mg2+ binding site located at the extracellular mouth of Kir2.2 that showed voltage-dependent Mg2+ binding. The mutants, G119D, Q126E and H128D, increased the number of permeant K+ ions and reduced the voltage-dependent blockade of Kir2.2 by extracellular Mg2+.
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Engineering Aspergillus oryzae A-4 through the chromosomal insertion of foreign cellulase expression cassette to improve conversion of cellulosic biomass into lipids.
PLoS ONE
PUBLISHED: 01-01-2014
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A genetic modification scheme was designed for Aspergillus oryzae A-4, a natural cellulosic lipids producer, to enhance its lipid production from biomass by putting the spotlight on improving cellulase secretion. Four cellulase genes were separately expressed in A-4 under the control of hlyA promoter, with the help of the successful development of a chromosomal genetic manipulation system. Comparison of cellulase activities of PCR-positive transformants showed that these transformants integrated with celA gene and with celC gene had significantly (p<0.05) higher average FPAase activities than those strains integrated with celB gene and with celD gene. Through the assessment of cellulosic lipids accumulating abilities, celA transformant A2-2 and celC transformant D1-B1 were isolated as promising candidates, which could yield 101%-133% and 35.22%-59.57% higher amount of lipids than the reference strain A-4 (WT) under submerged (SmF) conditions and solid-state (SSF) conditions, respectively. Variability in metabolism associated to the introduction of cellulase gene in A2-2 and D1-B1 was subsequently investigated. It was noted that cellulase expression repressed biomass formation but enhanced lipid accumulation; whereas the inhibitory effect on cell growth would be shielded during cellulosic lipids production owing to the essential role of cellulase in substrate utilization. Different metabolic profiles also existed between A2-2 and D1-B1, which could be attributed to not only different transgene but also biological impacts of different integration. Overall, both simultaneous saccharification and lipid accumulation were enhanced in A2-2 and D1-B1, resulting in efficient conversion of cellulose into lipids. A regulation of cellulase secretion in natural cellulosic lipids producers could be a possible strategy to enhance its lipid production from lignocellulosic biomass.
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Electrospun vancomycin-loaded coating on titanium implants for the prevention of implant-associated infections.
Int J Nanomedicine
PUBLISHED: 01-01-2014
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The objectives of this work were to develop an antibiotic coating on the surface of a titanium plate to determine its antibacterial properties in vitro and in vivo. To prepare vancomycin-coated titanium implants, we adopted the electrospinning nanotechnique. The surface structure of the coating implants was observed using a scanning electron microscope. An elution method and a high-pressure liquid chromatography assay were used to characterize the release behavior of vancomycin from the coating. The antibacterial efficacy and the cytotoxicity of the coated titanium implants on osteoblasts were investigated in vitro. In addition, X-ray, white blood cell count, C-reactive protein, erythrocyte sedimentation rate, and pathological examination were performed to validate its antimicrobial efficacy in vivo. The antibiotic coating released 82.7% (approximately 528.2 ?g) of total vancomycin loading in the coating in vitro. The release behavior of vancomycin from nanofiber coatings exhibited a biphasic release pattern with an initial burst on day 1, followed by a slow and controlled release over 28 days. There was no cytotoxicity observed in vitro for the vancomycin-loaded coating. The vancomycin-coated titanium implants were active in treating implant-associated infection in vivo. Thus, vancomycin-coated titanium implants may be a promising approach to prevent and treat implant-associated infections.
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Duck enteritis virus glycoprotein D and B DNA vaccines induce immune responses and immunoprotection in Pekin ducks.
PLoS ONE
PUBLISHED: 01-01-2014
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DNA vaccine is a promising strategy for protection against virus infection. However, little is known on the efficacy of vaccination with two plasmids for expressing the glycoprotein D (gD) and glycoprotein B (gB) of duck enteritis virus (DEV) in inducing immune response and immunoprotection against virulent virus infection in Pekin ducks. In this study, two eukaryotic expressing plasmids of pcDNA3.1-gB and pcDNA3.1-gD were constructed. Following transfection, the gB and gD expressions in DF1 cells were detected. Groups of ducks were vaccinated with pcDNA3.1-gB and/or pcDNA3.1-gD, and boosted with the same vaccine on day 14 post primary vaccination. We found that intramuscular vaccinations with pcDNA3.1-gB and/or pcDNA3.1-gD, but not control plasmid, stimulated a high frequency of CD4+ and CD8+ T cells in Pekin ducks, particularly with both plasmids. Similarly, vaccination with these plasmids, particularly with both plasmids, promoted higher levels of neutralization antibodies against DEV in Pekin ducks. More importantly, vaccination with both plasmids significantly reduced the virulent DEV-induced mortality in Pekin ducks. Our data indicated that vaccination with plasmids for expressing both gB and gD induced potent cellular and humoral immunity against DEV in Pekin ducks. Therefore, this vaccination strategy may be used for the prevention of DEV infection in Pekin ducks.
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Involvement of multiple types of dehydrins in the freezing response in loquat (Eriobotrya japonica).
PLoS ONE
PUBLISHED: 01-01-2014
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Dehydrins (DHNs) are a family of plant proteins typically induced in response to stress conditions that cause cellular dehydration, such as low temperatures, high salinity, and drought. Loquat (Eriobotrya japonica) is a perennial fruit crop that blossoms during winter. Loquat fruitlets are frequently injured by freezing. To evaluate the role of the EjDHNs in freezing resistance in loquat fruitlets, two cultivars of loquat, the freezing-sensitive 'Ninghaibai' (FS-NHB) and the freezing-tolerant 'Jiajiao' (FT-JJ), were analyzed under induced freezing stress. Freezing stress led to obvious accumulation of reactive oxygen species and considerable lipid peroxidation in membranes during the treatment period. Both these phenomena were more pronounced in 'FS-NHB' than in 'FS-JJ.' Immunogold labeling of dehydrin protein was performed. DHN proteins were found to be concentrated mainly in the vicinity of the plasma membrane, and the density of the immunogold labeling was significantly higher after freezing treatment, especially in the more freezing-tolerant cultivar 'FT-JJ.' Seven DHNs, showing four different structure types, were obtained from loquat fruitlets and used to study the characteristics of different EjDHN proteins. These DHN proteins are all highly hydrophilic, but they differ significantly in size, ranging from 188 to 475 amino acids, and in biochemical properties, such as theoretical pI, aliphatic index, and instability index. Freezing treatment resulted in up-regulation of the expression levels of all seven EjDHNs, regardless of structure type. The accumulation of the transcripts of these EjDHN genes was much more pronounced in 'FT-JJ' than in 'FS-NHB.' Altogether, this study provides evidence that EjDHNs are involved in the cryoprotection of the plasma membrane during freeze-induced dehydration in loquat fruitlets.
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Genome-wide detection of copy number variations among diverse horse breeds by array CGH.
PLoS ONE
PUBLISHED: 01-01-2014
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Recent studies have found that copy number variations (CNVs) are widespread in human and animal genomes. CNVs are a significant source of genetic variation, and have been shown to be associated with phenotypic diversity. However, the effect of CNVs on genetic variation in horses is not well understood. In the present study, CNVs in 6 different breeds of mare horses, Mongolia horse, Abaga horse, Hequ horse and Kazakh horse (all plateau breeds) and Debao pony and Thoroughbred, were determined using aCGH. In total, seven hundred CNVs were identified ranging in size from 6.1 Kb to 0.57 Mb across all autosomes, with an average size of 43.08 Kb and a median size of 15.11 Kb. By merging overlapping CNVs, we found a total of three hundred and fifty-three CNV regions (CNVRs). The length of the CNVRs ranged from 6.1 Kb to 1.45 Mb with average and median sizes of 38.49 Kb and 13.1 Kb. Collectively, 13.59 Mb of copy number variation was identified among the horses investigated and accounted for approximately 0.61% of the horse genome sequence. Five hundred and eighteen annotated genes were affected by CNVs, which corresponded to about 2.26% of all horse genes. Through the gene ontology (GO), genetic pathway analysis and comparison of CNV genes among different breeds, we found evidence that CNVs involving 7 genes may be related to the adaptation to severe environment of these plateau horses. This study is the first report of copy number variations in Chinese horses, which indicates that CNVs are ubiquitous in the horse genome and influence many biological processes of the horse. These results will be helpful not only in mapping the horse whole-genome CNVs, but also to further research for the adaption to the high altitude severe environment for plateau horses.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.