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Find video protocols related to scientific articles indexed in Pubmed.
Method for Transforming Alkynes into (E)-Dibromoalkenes.
J. Org. Chem.
PUBLISHED: 11-20-2014
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The highly stereoselective bromination of alkynes has been realized by using copper(II) bromide as both the reacting partner and the catalyst, offering a generally efficient synthesis of (E)-dibromoalkenes. The reaction conditions are exceptionally mild, and a wide range of functional groups are well tolerated.
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Biomimetic transparent and superhydrophobic coatings: from nature and beyond nature.
Chem. Commun. (Camb.)
PUBLISHED: 11-20-2014
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It is well known that high optical transparency is one of the most crucial criteria for the overwhelming majority of optical devices and correlative functions, including smart windows, camera lenses, solar cell systems and optoelectronic devices. With the frequent exposure of this equipment to all sorts of environments, such as outdoor conditions, a surface with self-cleaning properties can guard against fouling, humidity, bacterial growth and so forth. That is one type of application of the big family of superhydrophobic coatings. Therefore, integrating high transparency with self-cleaning characteristics is of great importance for such applications. In this review, the recent developments in designing, synthesizing and manufacturing transparent and superhydrophobic surfaces are reviewed. Firstly, the established theoretical aspects of surface wetting properties are summarized and then several natural and bio-inspired superhydrophobic surfaces of diverse microcosmic structures are presented as representative examples. With a focus on distinctively employed materials and the corresponding fabrication of superhydrophobic coatings with high transparency, the promising research directions and application prospects of this rapidly developing field are briefly addressed as well.
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The roles of maternal-effect proteins in the maintenance of genomic imprints.
Yi Chuan
PUBLISHED: 11-20-2014
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Genomic imprinting is a mechanism of differentially epigenetic modification that restricts monoallelic expression to either the maternally or paternally inherited copy of the gene during gametogenesis. Imprinted methylation undergoes a process of erasure, acquisition, and maintenance during gametogenesis and early embryogenesis. Disruptions in any of these steps may lead to imprinting disorders, resulting in the aberrant development of embryogenesis, placentation and postnatal growth. Recent studies have shown that maternal-effect proteins are important for the regulation of imprinted gene during the development of preimplantation embryos. In order to obtain a better understanding for the mechanism of maternal-effect proteins in the maintenance of genomic imprints, the recent study progress of maternal-effect proteins, such as DPPA3, ZFP57, TRIM28 and DNMT1, are summarized, and the regulation mechanism of these maternal-effect proteins for genomic imprints are discussed.
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Subtemporal-anterior transtentoral approach to middle cranial fossa microsurgical anatomy.
J Craniofac Surg
PUBLISHED: 11-08-2014
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This study aimed to describe the topography of inferior and external dura mater of the middle cranial fossa through subtemporal-anterior transpetrosal approach and discuss the feasibility of improving the approach. Eight formalin-fixed adult cadaveric heads were studied, with the bones milled away in the lateral triangle region of the petrous bone, Kawase rhombus region, and inner triangle region of the petrous apex. The distances between the targets in these regions, as well as the angles after the dissection of zygomatic arch, were measured, and then the exposed petroclival and retrochiasmatic areas were observed under the microscope. There were significant variations in the distances between targets in the 3 milled regions among the specimens. After the dissection of zygomatic arch, the surgical view got an average increase of 12 degrees. The subtemporal anterior transpetrosal approach, as an improved subtemporal approach, can expose the lesions optimally, causing no injury to the hearing and reducing injuries to temporal lobe. On the other hand, the lateral bone of the petrous parts of the temporal bone is removed so as to improve the view to the retrochiasmatic area and expand the operative field.
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Hairy Polyelectrolyte Brushes-Grafted Thermosensitive Microgels as Artificial Synovial Fluid for Simultaneous Biomimetic Lubrication and Arthritis Treatment.
ACS Appl Mater Interfaces
PUBLISHED: 10-28-2014
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We report the fabrication of poly(3-sulfopropyl methacrylate potassium salt) (PSPMK) brushes grafted poly(N-isopropylacrylamide) (PNIPAAm) microgels and their potential as artificial synovial fluid for biomimetic aqueous lubrication and arthritis treatment. The negatively charged PSPMK brushes and thermosensitive PNIPAAm microgels play water-based hydration lubrication and temperature-triggered drug release, respectively. Under soft friction pairs, an ultralow coefficient of friction was achieved, while the hairy thermosensitive microgels showed a desirable temperature-triggered drugs release performance. Such a soft charged hairy microgel offers great possibility for designing intelligent synovial fluid. What is more, the combination of lubrication and drug loading capabilities enables the large clinical potential of novel soft hairy nanoparticles as synthetic joint lubricant fluid in arthritis treatment.
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Spring Viremia of Carp Virus Induces Autophagy for Necessary Viral Replication.
Cell. Microbiol.
PUBLISHED: 10-21-2014
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Outbreaks of spring viremia of carp virus (SVCV) in several carp species and other cultivated fish can cause significant mortality and jeopardize the billion-dollar worldwide fish industry. SVCV, also known as Rhabdovirus carpio, is a bullet-shaped RNA virus that enters and amplifies in gill epithelium and later spreads to internal organs. Young fish under stressed conditions (spring cold water, etc.) are more vulnerable to SVCV-induced lethality due to their lack of a mature immune system. Currently, the host response of SVCV remains largely unknown. Here, we observed that autophagy is activated in SVCV-infected epithelioma papulosum cyprinid (EPC) cells. We demonstrated that the SVCV glycoprotein, rather than viral replication, activates the autophagy pathway. In addition, SVCV utilized the autophagy pathway to facilitate its own genomic RNA replication and to enhance its titers in the supernatants. Autophagy promoted the survival of SVCV-infected cells by eliminating damaged mitochondrial DNA generated during viral infection. We further showed that SVCV induces autophagy in EPC cells through the ERK/mTOR signaling pathway. Our results reveal a connection between autophagy and SVCV replication and propose autophagy suppression as a novel means to restrict SVCV viral replication.
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Biomimetic super-lyophobic and super-lyophilic materials applied for oil/water separation: a new strategy beyond nature.
Chem Soc Rev
PUBLISHED: 10-15-2014
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Oil spills and industrial organic pollutants have induced severe water pollution and threatened every species in the ecological system. To deal with oily water, special wettability stimulated materials have been developed over the past decade to separate oil-and-water mixtures. Basically, synergy between the surface chemical composition and surface topography are commonly known as the key factors to realize the opposite wettability to oils and water and dominate the selective wetting or absorption of oils/water. In this review, we mainly focus on the development of materials with either super-lyophobicity or super-lyophilicity properties in oil/water separation applications where they can be classified into four kinds as follows (in terms of the surface wettability of water and oils): (i) superhydrophobic and superoleophilic materials, (ii) superhydrophilic and under water superoleophobic materials, (iii) superhydrophilic and superoleophobic materials, and (iv) smart oil/water separation materials with switchable wettability. These materials have already been applied to the separation of oil-and-water mixtures: from simple oil/water layered mixtures to oil/water emulsions (including oil-in-water emulsions and water-in-oil emulsions), and from non-intelligent materials to intelligent materials. Moreover, they also exhibit high absorption capacity or separation efficiency and selectivity, simple and fast separation/absorption ability, excellent recyclability, economical efficiency and outstanding durability under harsh conditions. Then, related theories are proposed to understand the physical mechanisms that occur during the oil/water separation process. Finally, some challenges and promising breakthroughs in this field are also discussed. It is expected that special wettability stimulated oil/water separation materials can achieve industrial scale production and be put into use for oil spills and industrial oily wastewater treatment in the near future.
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Excited State Structural Events of a Dual-Emission Fluorescent Protein Biosensor for Ca(2+) Imaging Studied by Femtosecond Stimulated Raman Spectroscopy.
J Phys Chem B
PUBLISHED: 09-17-2014
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Fluorescent proteins (FPs) are luminescent biomolecules that emit characteristic hues upon irradiation. A group of calmodulin (CaM)-green FP (GFP) chimeras have been previously engineered to enable the optical detection of calcium ions (Ca(2+)). We investigate one of these genetically encoded Ca(2+) biosensors for optical imaging (GECOs), GEM-GECO1, which fluoresces green without Ca(2+) but blue with Ca(2+), using femtosecond stimulated Raman spectroscopy (FSRS). The time-resolved FSRS data (<800 cm(-1)) reveal that initial structural evolution following 400 nm photoexcitation involves small-scale coherent proton motions on both ends of the chromophore two-ring system with a <250 fs time constant. Upon Ca(2+) binding, the chromophore adopts a more twisted conformation in the protein pocket with increased hydrophobicity, which inhibits excited-state proton transfer (ESPT) by effectively trapping the protonated chromophore in S1. Both the chromophore photoacidity and local environment form the ultrafast structural dynamics basis for the dual-emission properties of GEM-GECO1. Its photochemical transformations along multidimensional reaction coordinates are evinced by distinct stages of FSRS spectral evolution, particularly related to the ?460 and 504 cm(-1) modes. The direct observation of lower frequency modes provides crucial information about the nuclear motions preceding ESPT, which enriches our understanding of photochemistry and enables the rational design of new biosensors.
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Microbial community analysis in rice paddy soils irrigated by acid mine drainage contaminated water.
Appl. Microbiol. Biotechnol.
PUBLISHED: 09-16-2014
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Five rice paddy soils located in southwest China were selected for geochemical and microbial community analysis. These rice fields were irrigated with river water which was contaminated by Fe-S-rich acid mine drainage. Microbial communities were characterized by high-throughput sequencing, which showed 39 different phyla/groups in these samples. Among these phyla/groups, Proteobacteria was the most abundant phylum in all samples. Chloroflexi, Acidobacteria, Nitrospirae, and Bacteroidetes exhibited higher relative abundances than other phyla. A number of rare and candidate phyla were also detected. Moreover, canonical correspondence analysis suggested that pH, sulfate, and nitrate were significant factors that shaped the microbial community structure. In addition, a wide diversity of Fe- and S-related bacteria, such as GOUTA19, Shewanella, Geobacter, Desulfobacca, Thiobacillus, Desulfobacterium, and Anaeromyxobacter, might be responsible for biogeochemical Fe and S cycles in the tested rice paddy soils. Among the dominant genera, GOUTA19 and Shewanella were seldom detected in rice paddy soils.
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Clinical Course of Diabetes After Gastrectomy According to Type of Reconstruction in Patients with Concurrent Gastric Cancer and Type 2 Diabetes.
Obes Surg
PUBLISHED: 09-05-2014
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This study was conducted to evaluate course of diabetes after gastrectomy according to type of reconstruction performed for gastric cancer in patients with type 2 diabetes.
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Thermoreversible gel lubricants through universal supramolecular assembly of a nonionic surfactant in a variety of base lubricating liquids.
ACS Appl Mater Interfaces
PUBLISHED: 09-03-2014
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The present paper investigates a new type of thermoreversible gel lubricant obtained by supramolecular assembly of low-molecular-weight organic gelator (LMWG) in different base oils. The LMWG is a nonionic surfactant with polar headgroup and hydrophobic tail that can self-assemble through collective noncovalent intermolecular interactions (H-bonding, hydrophobic interaction) to form fibrous structures and trap base oils (mineral oils, synthetic oils, and water) in the as-formed cavities. The gel lubricants are fully thermoreversible upon heating-up and cooling down and exhibit thixotropic characteristics. This makes them semisolid lubricants, but they behave like oils. The tribological test results disclosed that the LMWG could also effectively reduce friction and wear of sliding pairs compared with base oils without gelator. It is expected that when being used in oil-lubricated components, such as gear, rolling bearing, and so on, gel lubricant may effectively avoid base oil leak and evaporation loss and so is a benefit to operation and lubrication failure for a long time.
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Transformation of the education of health professionals in China: progress and challenges.
Lancet
PUBLISHED: 09-02-2014
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In this Review we examine the progress and challenges of China's ambitious 1998 reform of the world's largest health professional educational system. The reforms merged training institutions into universities and greatly expanded enrolment of health professionals. Positive achievements include an increase in the number of graduates to address human resources shortages, acceleration of production of diploma nurses to correct skill-mix imbalance, and priority for general practitioner training, especially of rural primary care workers. These developments have been accompanied by concerns: rapid expansion of the number of students without commensurate faculty strengthening, worries about dilution effect on quality, outdated curricular content, and ethical professionalism challenged by narrow technical training and growing admissions of students who did not express medicine as their first career choice. In this Review we underscore the importance of rebalance of the roles of health sciences institutions and government in educational policies and implementation. The imperative for reform is shown by a looming crisis of violence against health workers hypothesised as a result of many factors including deficient educational preparation and harmful profit-driven clinical practices.
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De novo mutations in beta-catenin (CTNNB1) appear to be a frequent cause of intellectual disability: expanding the mutational and clinical spectrum.
Hum. Genet.
PUBLISHED: 08-15-2014
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Recently, de novo heterozygous loss-of-function mutations in beta-catenin (CTNNB1) were described for the first time in four individuals with intellectual disability (ID), microcephaly, limited speech and (progressive) spasticity, and functional consequences of CTNNB1 deficiency were characterized in a mouse model. Beta-catenin is a key downstream component of the canonical Wnt signaling pathway. Somatic gain-of-function mutations have already been found in various tumor types, whereas germline loss-of-function mutations in animal models have been shown to influence neuronal development and maturation. We report on 16 additional individuals from 15 families in whom we newly identified de novo loss-of-function CTNNB1 mutations (six nonsense, five frameshift, one missense, two splice mutation, and one whole gene deletion). All patients have ID, motor delay and speech impairment (both mostly severe) and abnormal muscle tone (truncal hypotonia and distal hypertonia/spasticity). The craniofacial phenotype comprised microcephaly (typically -2 to -4 SD) in 12 of 16 and some overlapping facial features in all individuals (broad nasal tip, small alae nasi, long and/or flat philtrum, thin upper lip vermillion). With this detailed phenotypic characterization of 16 additional individuals, we expand and further establish the clinical and mutational spectrum of inactivating CTNNB1 mutations and thereby clinically delineate this new CTNNB1 haploinsufficiency syndrome.
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A graphene quantum dot photodynamic therapy agent with high singlet oxygen generation.
Nat Commun
PUBLISHED: 08-08-2014
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Clinical applications of current photodynamic therapy (PDT) agents are often limited by their low singlet oxygen ((1)O2) quantum yields, as well as by photobleaching and poor biocompatibility. Here we present a new PDT agent based on graphene quantum dots (GQDs) that can produce (1)O2 via a multistate sensitization process, resulting in a quantum yield of ~1.3, the highest reported for PDT agents. The GQDs also exhibit a broad absorption band spanning the UV region and the entire visible region and a strong deep-red emission. Through in vitro and in vivo studies, we demonstrate that GQDs can be used as PDT agents, simultaneously allowing imaging and providing a highly efficient cancer therapy. The present work may lead to a new generation of carbon-based nanomaterial PDT agents with overall performance superior to conventional agents in terms of (1)O2 quantum yield, water dispersibility, photo- and pH-stability, and biocompatibility.
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Variation of nonylphenol-degrading gene abundance and bacterial community structure in bioaugmented sediment microcosm.
Environ Sci Pollut Res Int
PUBLISHED: 07-16-2014
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Nonylphenol (NP) can accumulate in river sediment. Bioaugmentation is an attractive option to dissipate heavy NP pollution in river sediment. In this study, two NP degraders were isolated from crude oil-polluted soil and river sediment. Microcosms were constructed to test their ability to degrade NP in river sediment. The shift in the proportion of NP-degrading genes and bacterial community structure in sediment microcosms were characterized using quantitative PCR assay and terminal restriction fragment length polymorphism analysis, respectively. Phylogenetic analysis indicated that the soil isolate belonged to genus Stenotrophomonas, while the sediment isolate was a Sphingobium species. Both of them could almost completely clean up a high level of NP in river sediment (150 mg/kg NP) in 10 or 14 days after inoculation. An increase in the proportion of alkB and sMO genes was observed in sediment microcosms inoculated with Stenotrophomonas strain Y1 and Sphingobium strain Y2, respectively. Moreover, bioaugmentation using Sphingobium strain Y2 could have a strong impact on sediment bacterial community structure, while inoculation of Stenotrophomonas strain Y1 illustrated a weak impact. This study can provide some new insights towards NP biodegradation and bioremediation.
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Well-ordered polymer nano-fibers with self-cleaning property by disturbing crystallization process.
Nanoscale Res Lett
PUBLISHED: 07-15-2014
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Bionic self-cleaning surfaces with well-ordered polymer nano-fibers are firstly fabricated by disturbing crystallization during one-step coating-curing process. Orderly thin (100 nm) and long (5-10 ?m) polymer nano-fibers with a certain direction are fabricated by external macroscopic force (F blow) interference introduced by H2 gas flow, leading to superior superhydrophobicity with a water contact angle (WCA) of 170° and a water sliding angle (WSA) of 0-1°. In contrast, nano-wires and nano-bridges (1-8 ?m in length/10-80 nm in width) are generated by "spinning/stretching" under internal microscopic force (F T) interference due to significant temperature difference in the non-uniform cooling medium. The findings provide a novel theoretical basis for controllable polymer "bionic lotus" surface and will further promote practical application in many engineering fields such as drag-reduction and anti-icing.
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Core-shell-corona-structured polyelectrolyte brushes-grafting magnetic nanoparticles for water harvesting.
ACS Appl Mater Interfaces
PUBLISHED: 07-02-2014
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A novel superhydrophilic material, charged polymer brushes-grafted magnetic core-shell-corona composite nanoparticles (Fe3O4@SiO2@PSPMA), was developed to harvest water through the hydration effect. Because of both the strong hydration capability and the good swelling performance, the negatively charged polymer brushes, PSPMA brushes, endow the composite nanoparticles with superhydrophilicity and a good water-absorbing performance like a sponge, while the magnetic Fe3O4 cores allow easy separation of Fe3O4@SiO2@PSPMA nanoparticles with absorbed water from oil/water mixture under an external magnetic field. The functional particles have the capability of harvesting water droplets whether floating on an oil surface or in the oil. This water-absorbing material uses selective wettability to harvest water and achieve oil-water separation and may be useful in finding novel approaches for recycling water from sewage and removing water in the petroleum industry.
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Excited-state structural dynamics of a dual-emission calmodulin-green fluorescent protein sensor for calcium ion imaging.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 07-01-2014
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Fluorescent proteins (FPs) have played a pivotal role in bioimaging and advancing biomedicine. The versatile fluorescence from engineered, genetically encodable FP variants greatly enhances cellular imaging capabilities, which are dictated by excited-state structural dynamics of the embedded chromophore inside the protein pocket. Visualization of the molecular choreography of the photoexcited chromophore requires a spectroscopic technique capable of resolving atomic motions on the intrinsic timescale of femtosecond to picosecond. We use femtosecond stimulated Raman spectroscopy to study the excited-state conformational dynamics of a recently developed FP-calmodulin biosensor, GEM-GECO1, for calcium ion (Ca(2+)) sensing. This study reveals that, in the absence of Ca(2+), the dominant skeletal motion is a ? 170 cm(-1) phenol-ring in-plane rocking that facilitates excited-state proton transfer (ESPT) with a time constant of ? 30 ps (6 times slower than wild-type GFP) to reach the green fluorescent state. The functional relevance of the motion is corroborated by molecular dynamics simulations. Upon Ca(2+) binding, this in-plane rocking motion diminishes, and blue emission from a trapped photoexcited neutral chromophore dominates because ESPT is inhibited. Fluorescence properties of site-specific protein mutants lend further support to functional roles of key residues including proline 377 in modulating the H-bonding network and fluorescence outcome. These crucial structural dynamics insights will aid rational design in bioengineering to generate versatile, robust, and more sensitive optical sensors to detect Ca(2+) in physiologically relevant environments.
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Bacteria diversity, distribution and insight into their role in S and Fe biogeochemical cycling during black shale weathering.
Environ. Microbiol.
PUBLISHED: 06-09-2014
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A group of black shale samples, which were collected sequentially along a continuous depositional unit from bottom fresh zone toward the surface regolith of the weathering profile at Chengkou County, Southwest China, were examined using mineralogical, geochemical and pyrosequencing techniques. The mineralogical and geochemical analyses indicated that the black shale profile provided a series of extremely acidic and chemical species that changed microbial habitats following the process of weathering. This finding is in contrast with a previous hypothesis that a low-diversity bacterial community existed in these harsh environments; the pyrosequencing analyses showed extremely diverse microbial communities with 33 different phyla/groups in these samples. Among these phyla/groups, proteobacteria, actinobacteria and firmcutes were more dominant than other phyla, and the phylogenetic structures of the bacterial communities vary with the progressive process of weathering. Moreover, the canonical-correlation analysis suggested that pH and sulfur in sulfate, followed by total Fe and sulfur in pyrite, are the significant factors that shape the microbial community structure. In addition, a large proportion of S- and Fe-related bacteria, such as Acidithiobacillus, Sulfobacillus, Thiobacillus, Ferrimicrobium and Ferrithrix, may be responsible for pyrite bio-oxidation, as well as for S and Fe biogeochemical cycling, in the black shale weathering environments.
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A Comprehensive Transcriptome Provides Candidate Genes for Sex Determination/Differentiation and SSR/SNP Markers in Yellow Catfish.
Mar. Biotechnol.
PUBLISHED: 06-04-2014
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Sex dimorphic growth pattern has significant theory and application implications in fish. Recently, a Y- and X-specific allele marker-assisted sex control technique has been developed for mass production of all-male population in yellow catfish (Pelteobagrus fulvidraco), but the genetic information for sex determination and sex control breeding has remained unclear. Here, we attempted to provide the first insight into a comprehensive transcriptome covering multiple tissues from XX females, XY males, and YY super-males of yellow catfish by using 454 GS-FLX platform, for a better assembly and gene coverage. A total of 1,202,933 high quality reads (about 540 Mbp) were obtained and assembled into 28,297 contigs and 141,951 singletons. BLASTX searches against the NCBI non-redundant protein database (nr) led a total of 52,564 unique sequences including 18,748 contigs and 33,816 singletons to match 25,669 known or predicted unique proteins. All of them with annotated function were categorized by gene ontology (GO) analysis, and 712 were assigned to reproduction and reproductive process. Some potential genes relevant to reproductive system including steroid hormone biosynthesis and GnRH (gonadotropin-releasing hormone) signaling pathway were further identified by Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis; and at least 21 sex determination and differentiation-related genes, such as Dmrt1, Sox9a/b, Cyp19b, WT1, and AMH were identified and characterized. Additionally, a total of 82,794 simple sequence repeats (SSRs), 26,450 single nucleotide polymorphisms (SNPs), and 4,145 insertions and deletions (INDELs) were revealed from the transcriptome data. Therefore, the current transcriptome resources highlight further studies on sex-control breeding in yellow catfish and will benefit future studies on reproduction and sex determination in teleost fish.
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Allotransplanted DRG neurons or Schwann cells affect functional recovery in a rodent model of sciatic nerve injury.
Neurol. Res.
PUBLISHED: 05-18-2014
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In this study, the functional recoveries of Sprague-Dawley rats following repair of a complete sciatic nerve transection using allotransplanted dorsal root ganglion (DRG) neurons or Schwann cells were examined using a number of outcome measures.
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Neuropsychiatric symptoms accompanying thrombocytopenia following pregabalin treatment for neuralgia: a case report.
Int J Clin Pharm
PUBLISHED: 05-08-2014
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A 28-year-old female patient developed an increased temperature and neuropsychiatric symptoms after receiving 75 mg pregabalin therapy for neuralgia. She presented initially with pyrexia and dizziness, followed by disorganized speech within an acute confusional state. Her body temperature returned to normal after taking 60 mg loxoprofen sodium several hours later. However, the neuropsychiatric symptoms did not improve until the next morning. Routine blood tests showed decreased platelet counts (from 131 × 109/L to 85 × 109/L). The following day, a further dose of 75 mg pregabalin was administered because of its effective amelioration of the patient's neuralgia. One hour later, the same symptoms appeared as had previously including increased body temperature of 39.2 °C accompanied by a lower platelet count (73 × 109/L).
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Charged polymer brushes-grafted hollow silica nanoparticles as a novel promising material for simultaneous joint lubrication and treatment.
J Phys Chem B
PUBLISHED: 04-25-2014
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The fabrication of core/shell charged polymer brushes-grafted hollow silica nanoparticles (PSPMA-g-HSNPs) is reported. Because of the excellent hydration capability of the shells consisting of charged polymer brushes, the functional nanoparticles can achieve a good lubricating effect in aqueous media via hydration lubrication mechanism. The mesoporous hollow silica cores endow the nanoparticles with drug loading-release capability. Aspirin, as a useful drug for treating arthritis, was employed to carry out in vitro drug loading and release studies. It is clear that brushes-modified hollow silica exhibited long-term drug release performance. The combination of lubrication and drug loading capabilities results in the great clinical potential of new multifunctional nanoparticles as injectable joint lubricant fluid in arthritis treatment.
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Underwater superoleophobic graphene oxide coated meshes for the separation of oil and water.
Chem. Commun. (Camb.)
PUBLISHED: 04-12-2014
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Hydrophilic graphene oxide (GO) nanosheets can be easily coated onto stainless steel meshes. Compared to neat meshes, GO coated meshes become more hydrophilic in air and superoleophobic under water. Taking advantage of this completely opposite wettability, GO coated meshes were used for gravity-driven oil-water separation.
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Photonic crystal fiber half-taper probe based refractometer.
Opt Lett
PUBLISHED: 04-02-2014
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A compact single-mode photonic crystal fiber single-mode fiber tip (SPST) refractive index sensor is demonstrated in this Letter. A CO2 laser cleaving technique is utilized to provide a clean-cut fiber tip, which is then coated by a layer of gold to increase reflection. An average sensitivity of 39.1 nm/RIU and a resolvable index change of 2.56×10(-4) are obtained experimentally with a ?3.2 ?m diameter SPST. The temperature dependence of this fiber-optic sensor probe is presented. The proposed SPST refractometer is also significantly less sensitive to temperature and an experimental demonstration of this reduced sensitivity is presented in the Letter. Because of its compactness, ease of fabrication, linear response, low temperature dependency, easy connectivity to other fiberized optical components and low cost, this refractometer could find various applications in chemical and biological sensing.
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Phanerochaete chrysosporium inoculation shapes the indigenous fungal communities during agricultural waste composting.
Biodegradation
PUBLISHED: 03-27-2014
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Inoculation with exogenous white-rot fungi has been proven to be an efficient method to promote lignocellulose biodegradation during agricultural waste composting. Indigenous fungal communities, the most important organisms responsible for mineralization and decomposition of lignocellulosic materials in composts, can be affected by sample properties and other biotic factors. This research was conducted to determine the effects of the Phanerochaete chrysosporium inoculation on the indigenous fungal communities during agricultural waste composting. Fungal communities in samples with different inoculation regimes were investigated by sequencing and quantitative PCR. Results showed that P. chrysosporium inoculants produced significant negative effects on the indigenous fungal community abundance during the thermophilic stage. Samples inoculated during Phase II contained higher proportion of Acremonium chrysogenum and Galactomyces geotrichum, while those non-inoculated samples were dominated by Coprinopsis cinerea and Scytalidium thermophilum. Moreover, the indigenous fungal community abundance was significantly correlated with the C/N ratio, water soluble carbon and moisture content (P < 0.05). Redundancy analysis indicated that the most variation in distribution of indigenous fungal community structure was statistically explained by nitrate, C/N ratio, and moisture content, factors which solely explained 29.6 % (F = 30.316, P = 0.002), 25.6 % (F = 26.191, P = 0.002) and 10.0 % (F = 10.249, P = 0.002) of the variation in the indigenous fungal community structure, respectively.
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Sequence analysis and expression regulation of rbp4 by 9-cis-RA in Megalobrama amblycephala.
Fish Physiol. Biochem.
PUBLISHED: 03-24-2014
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Retinol-binding protein 4 (rbp4) is mainly synthesized in the liver, where it binds retinol and then enters the bloodstream, delivering retinol to cells. The full-length cDNA coding rbp4 was cloned from Megalobrama amblycephala. The amino acid sequence showed strong homology with the homologues of other vertebrates, and all structural and functional domains were highly conserved. The mRNA levels in different tissues and development stages detected by quantitative real-time PCR revealed that M. amblycephala rbp4 was highly expressed in liver (P < 0.001), but the lower levels were also detected in eyes, kidney, intestine, and spleen. During the different development stages, the rbp4 mRNA appeared until 28 hours post-fertilization (hpf), underwent a slight drop, and then gradually increased after 50 hpf. In addition, the promoter sequence of M. amblycephala rbp4 was obtained using thermal asymmetric interlaced PCR. Two single nucleotide polymorphism sites (-385A>G and -329C>T) were found in the promoter. Transfection with recombinant plasmids of two different haplotypes (GT, AC) showed that 9-cis-retinoic acid (RA) increased the promoter activity, but the AC haplotype was more sensitive to RA.
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Endothelial cell-specific liver kinase B1 deletion causes endothelial dysfunction and hypertension in mice in vivo.
Circulation
PUBLISHED: 03-17-2014
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Liver kinase B1 (LKB1), a tumor suppressor, is a central regulator of cell polarity and energy homeostasis. The role of LKB1 in endothelial function in vivo has not been explored.
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Assessment of Nogo-66 receptor 1 function in vivo after spinal cord injury.
Neurosurgery
PUBLISHED: 03-06-2014
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Neuronal Nogo-66 receptor 1 (NgR1) has attracted attention as a converging point for mediating the effects of myelin-associate inhibitory ligands in the central nervous system, establishing the growth-restrictive environment, and limiting axon regeneration after traumatic injury.
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Adhesion behaviors on superhydrophobic surfaces.
Chem. Commun. (Camb.)
PUBLISHED: 02-27-2014
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The adhesion behaviors of superhydrophobic surfaces have become an emerging topic to researchers in various fields as a vital step in the interactions between materials and organisms/materials. Controlling the chemical compositions and topological structures via various methods or technologies is essential to fabricate and modulate different adhesion properties, such as low-adhesion, high-adhesion and anisotropic adhesion on superhydrophobic surfaces. We summarize the recent developments in both natural superhydrophobic surfaces and artificial superhydrophobic surfaces with various adhesions and also pay attention to superhydrophobic surfaces switching between low- and high-adhesion. The methods to regulate or translate the adhesion of superhydrophobic surfaces can be considered from two perspectives. One is to control the chemical composition and change the surface geometric structure on the surfaces, respectively or simultaneously. The other is to provide external stimulations to induce transitions, which is the most common method for obtaining switchable adhesions. Additionally, adhesion behaviors on solid-solid interfaces, such as the behaviors of cells, bacteria, biomolecules and icing on superhydrophobic surfaces are also noticeable and controversial. This review is aimed at giving a brief and crucial overview of adhesion behaviors on superhydrophobic surfaces.
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Laxative inspired ionic liquid lubricants with good detergency and no corrosion.
ACS Appl Mater Interfaces
PUBLISHED: 02-27-2014
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1-Alkyl-3-methylimidazolium bis(2-ethylhexyl)sulfosuccinate (L-DOSS10n, n = 2, 4, 8) ionic liquids (ILs) were synthesized from dioctyl sodium sulfosuccinate (NaDOSS), which is a cheap, bulk available laxative medicine used for the treatment of constipation. The ILs showed lower corrosion levels and higher hydrolysis stabilities than conventional ILs such as 1-butyl-3-methyl imidazolium tetrafluoroborate (L-B104) and 1-butyl-3-methyl imidazolium bis(trifluoromethylsulfonyl)imide (L-F104) due to their halogen-free characteristic. The tribological properties of the ILs were also better than those of L-B104 and L-F104 for various contacts. Thus, they can be used as replacements for conventional IL lubricants, which may solve the problems of corrosion and high cost to put conventional IL lubricants into industrial application. Coking test results indicated that the synthesized ILs have high deterging ability. Thus, these ILs may be used as lubricants that restrain carbonaceous deposition as well as oil sludge and varnish formation on the metal contacts during the sliding process. Moreover, the synthesized ILs can disperse, loosen, and remove the already formed harmful substances and keep the metal contacts clean.
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Pathogenesis analysis of pituitary adenoma based on gene expression profiling.
Oncol Lett
PUBLISHED: 02-13-2014
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The aim of the current study was to investigate the pathogenesis of pituitary adenoma through screening of the differentially-expressed genes (DEGs) and proteins in normal pituitary and pituitary adenoma tissues, and analyzing the interactions among them. Following the acquisition of gene expression profiling data from a public functional genomics data repository, Gene Expression Omnibus, DEGs were screened in normal pituitary and pituitary adenoma tissues. Upregulated and downregulated DEGs were further identified through gene ontology functional enrichment analysis. Subsequently, the DEGs were mapped to the Search Tool for the Retrieval of Interacting Genes database, and the protein-protein interaction (PPI) networks of the upregulated and downregulated DEGs were constructed. Finally, the functional modules of the PPI network of the downregulated DEGs were analyzed. In total, 211 upregulated and 413 downregulated DEGs were screened between the normal pituitary and pituitary adenoma samples. Downregulated DEGs were associated with certain functions, including the immune response, hormone regulation and cell proliferation. Upregulated genes were associated with cation transport functions. Five modules were acquired from the PPI network of the downregulated DEGs. Transcription factors, including signal transducer and activator of transcription 3 (STAT3), interleukin 6 (IL-6), B-cell lymphoma 6 protein, early growth response 1, POU1F1, jun B proto-oncogene and FOS were the core nodes in the functional modules. In summary, the DEGs and proteins were identified through screening gene expression profiling and PPI networks. The results of the present study indicated that low expression levels of hormone- and immune-related genes facilitated the occurrence of pituitary adenoma. Low expression levels of IL-6 and STAT3 were significant in the dysimmunity of pituitary adenoma. Furthermore, the low expression level of POU1F1 contributed to the reduction in pituitary hormone secretion.
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DNA from pre-erythrocytic stage malaria parasites is detectable by PCR in the faeces and blood of hosts.
Int. J. Parasitol.
PUBLISHED: 02-05-2014
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Following the bite of an infective mosquito, malaria parasites first invade the liver where they develop and replicate for a number of days before being released into the bloodstream where they invade red blood cells and cause disease. The biology of the liver stages of malaria parasites is relatively poorly understood due to the inaccessibility of the parasites to sampling during this phase of their life cycle. Here we report the detection in blood and faecal samples of malaria parasite DNA throughout their development in the livers of mice and before the parasites begin their growth in the blood circulation. It is shown that parasite DNA derived from pre-erythrocytic stage parasites reaches the faeces via the bile. We then show that different primate malaria species can be detected by PCR in blood and faecal samples from naturally infected captive macaque monkeys. These results demonstrate that pre-erythrocytic parasites can be detected and quantified in experimentally infected animals. Furthermore, these results have important implications for both molecular epidemiology and phylogenetics of malaria parasites. In the former case, individuals who are malaria parasite negative by microscopy, but PCR positive for parasite DNA in their blood, are considered to be "sub-microscopic" blood stage parasite carriers. We now propose that PCR positivity is not necessarily an indicator of the presence of blood stage parasites, as the DNA could derive from pre-erythrocytic parasites. Similarly, in the case of molecular phylogenetics based on DNA sequences alone, we argue that DNA amplified from blood or faeces does not necessarily come from a parasite species that infects the red blood cells of that particular host.
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Ultra- and microstructure of the female reproductive system of Matsucoccus matsumurae.
Arthropod Struct Dev
PUBLISHED: 02-01-2014
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The ultra- and microstructure of the female reproductive system of Matsucoccus matsumurae was studied using light microscopy, scanning and transmission electron microscopy. The results revealed that the female reproductive system of M. matsumurae is composed of a pair of ovaries, a common oviduct, a pair of lateral oviducts, a spermatheca and two pairs of accessory glands. Each ovary is composed of approximately 50 telotrophic ovarioles that are devoid of terminal filaments. Each ovariole is subdivided into an apical tropharium, a vitellarium and a short pedicel connected to a lateral oviduct. The tropharium contains 8-10 trophocytes and two early previtellogenic oocytes termed arrested oocytes. The trophocytes degenerate after egg maturation, and the arrested oocytes are capable of further development. The vitellarium contains 3-6 oocytes of different developmental stages: previtellogenesis, vitellogenesis and choriogenesis. The surface of the vitellarium is rough and composed of a pattern of polygonal reticular formations with a center protuberance. The oocyte possesses numerous yolk spheres and lipid droplets, and is surrounded by a mono-layered follicular epithelium that becomes binucleate at the beginning of vitellogenesis. Accessory nuclei are observed in the peripheral ooplasm during vitellogenesis.
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African origin of the malaria parasite Plasmodium vivax.
Nat Commun
PUBLISHED: 01-29-2014
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Plasmodium vivax is the leading cause of human malaria in Asia and Latin America but is absent from most of central Africa due to the near fixation of a mutation that inhibits the expression of its receptor, the Duffy antigen, on human erythrocytes. The emergence of this protective allele is not understood because P. vivax is believed to have originated in Asia. Here we show, using a non-invasive approach, that wild chimpanzees and gorillas throughout central Africa are endemically infected with parasites that are closely related to human P. vivax. Sequence analyses reveal that ape parasites lack host specificity and are much more diverse than human parasites, which form a monophyletic lineage within the ape parasite radiation. These findings indicate that human P. vivax is of African origin and likely selected for the Duffy-negative mutation. All extant human P. vivax parasites are derived from a single ancestor that escaped out of Africa.
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Nonylphenol biodegradation in river sediment and associated shifts in community structures of bacteria and ammonia-oxidizing microorganisms.
Ecotoxicol. Environ. Saf.
PUBLISHED: 01-27-2014
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Nonylphenol (NP) is one of commonly detected contaminants in the environment. Biological degradation is mainly responsible for remediation of NP-contaminated site. Knowledge about the structure of NP-degrading microbial community is still very limited. Microcosms were constructed to investigate the structure of microbial community in NP-contaminated river sediment and its change with NP biodegradation. A high level of NP was significantly dissipated in 6-9 days. Bacteria and ammonia-oxidizing archaea (AOA) were more responsive to NP amendment compared to ammonia-oxidizing bacteria (AOB). Gammaproteobacteria, Alphaproteobacteria and Bacteroidetes were the largest bacterial groups in NP-degrading sediment. Microorganisms from bacterial genera Brevundimonas, Flavobacterium, Lysobacter and Rhodobacter might be involved in NP degradation in river sediment. This study provides some new insights towards NP biodegradation and microbial ecology in NP-contaminated environment.
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Unconventional assembly of bimetallic Au-Ni janus nanoparticles on chemically modified silica spheres.
Chemistry
PUBLISHED: 01-15-2014
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This paper reports that Janus Au-Ni nanoparticles (JANNPs) can self-assemble onto silica spheres in a novel way, which is different from that of single-component isotropic nanoparticles. JANNPs modified with octadecylamine (ODA) assemble onto catechol-modified silica spheres (SiO2-OH) to form a very special core-loop complex structure and finally the core-loop assemblies link each other to form large assemblies through capillary force and the hydrophobic interaction of the alkyl chains of ODA. The nanocomposites disassemble in the presence of vanillin and oleic acid because of the breakage of the catechol-metal link. Vanillin-induced disassembly enables the JANNPs to reassemble into a core-loop structure upon ODA addition. The assembly of SiO2-OH and isotropic Ni or Fe3O4 particles generates traditional core-satellite structures. This unconventional self-assembly can be attributed to the synergistic effect of Janus specificity and capillary force, which is also confirmed by the assembly of thiol-terminated silica spheres (SH-SiO2) with anisotropic JANNPs, isotropic Au, and Ni nanoparticles. These results can guide the development of novel composite materials using Janus nanoparticles as the primary building blocks.
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Drug-eluting stent, but not bare metal stent, accentuates the systematic inflammatory response in patients.
Cardiology
PUBLISHED: 01-09-2014
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The systematic pro-inflammatory responses after percutaneous coronary intervention with drug-eluting stents (DES) remain poorly defined. Therefore, we compared the systematic pro-inflammatory state of circulating mononuclear cells (MNCs) between DES and bare metal stent (BMS) implantation.
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The wax glands and wax secretion of Matsucoccus matsumurae at different development stages.
Arthropod Struct Dev
PUBLISHED: 01-08-2014
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In this paper, the wax secretions and wax glands of Matsucoccus matsumurae (Kuwana) at different instars were investigated using light microscopy, scanning electron microscopy and transmission electron microscopy. The first and second instar nymphs were found to secrete wax filaments via the wax glands located in the atrium of the abdominal spiracles, which have a center open and a series of outer ring pores. The wax gland of the abdominal spiracle possesses a large central wax reservoir and several wax-secreting cells. Third-instar male nymphs secreted long and translucent wax filaments from monolocular, biolocular, trilocular and quadrilocular pores to form twine into cocoons. The adult male secreted long and straight wax filaments in bundles from a group of 18-19 wax-secreting tubular ducts on the abdominal segment VII. Each tube duct contained five or six wax pores. The adult female has dorsal cicatrices distributed in rows, many biolocular tubular ducts and multilocular disc pores with 8-12 loculi secreting wax filaments that form the egg sac, and a rare type wax pores with 10 loculi secreting 10 straight, hollow wax filaments. The ultrastructure and cytological characteristics of the wax glands include wax-secreting cells with a large nucleus, multiple mitochondria and several rough endoplasmic reticulum. The functions of the wax glands and wax secretions are discussed.
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Template-free preparation of volvox-like Cd(x)Zn(1-x)S nanospheres with cubic phase for efficient photocatalytic hydrogen production.
Chem Asian J
PUBLISHED: 01-08-2014
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Volvox-like Cdx Zn1-x S solid solutions with a cubic zinc blend structure were synthesized through a template-free ethylene glycol process. Cd(Ac)2 ?2?H2 O, Zn(Ac)2 ?2?H2 O, and thiourea are used as the starting materials and dissolved in ethylene glycol. These reaction precursors and solvent not only contributed to control over the formation of the volvox-like spherical geometry, but also exerted vigorous domination for existence of cubic-phase Cdx Zn1-x S nanostructures. As-prepared volvox-like Cdx Zn1-x S nanospheres have a diameter of around 100?nm with extensional shells. These samples show excellent photocatalytic H2 evolution activity from water splitting under visible-light irradiation without any cocatalyst or scaffolding, owing to their tunable band gap, cubic zinc blend structure, and unique hierarchical porous structure with a high surface area (as high as 95.2?m(2) ?g(-1) ).
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Sex-biased miRNAs in gonad and their potential roles for testis development in yellow catfish.
PLoS ONE
PUBLISHED: 01-01-2014
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Recently, YY super-male yellow catfish had been created by hormonal-induced sex reversal and sex-linked markers, which provides a promising research model for fish sex differentiation and gonad development, especially for testis development. MicroRNAs (miRNAs) have been revealed to play crucial roles in the gene regulation and gonad development in vertebrates. In this study, three small RNA libraries constructed from gonad tissues of XX female, XY male and YY super-male yellow catfish were sequenced. The sequencing data generated a total of 384 conserved miRNAs and 113 potential novel miRNAs, among which 23, 30 and 14 miRNAs were specifically detected in XX ovary, XY testis, and YY testis, respectively. We observed relative lower expression of several miR-200 family members, including miR-141 and miR-429 in YY testis compared with XY testis. Histological analysis indicated a higher degree of testis maturity in YY super-males compared with XY males, as shown by larger spermatogenic cyst, more spermatids and fewer spermatocytes in the spermatogenic cyst. Moreover, five miR-200 family members were significantly up-regulated in testis when treated by 17?-ethinylestradiol (EE2), high dose of which will impair testis development and cell proliferation. The down-regulation of miR-141 and 429 coincides with the progression of testis development in both yellow catfish and human. At last, the expression pattern of nine arbitrarily selected miRNAs detected by quantitative RT-PCR was consistent with the Solexa sequencing results. Our study provides a comprehensive miRNA transcriptome analysis for gonad of yellow catfish with different sex genotypes, and identifies a number of sex-biased miRNAs, some of that are potentially involved in testis development and spermatogenesis.
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A case of chronic hepatitis C patient of myocardial ischemia accompanied with interstitial pneumonia induced by pegylated interferon alpha-2a.
Int J Clin Exp Pathol
PUBLISHED: 01-01-2014
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After 3 months of combination treatment using interferon ?-2a and Ribavirin, a case of 59-year-old female patient with chronic viral hepatitis C demonstrated symptoms such as headache, dizziness accompanied by nausea, vomiting, dry cough, breathing difficulty, and shortness of breath. Dynamic electrocardiogram showed occasional atrial premature beats, paroxysmal tachycardia, and abnormal ST-T (T wave inversion and prolongation of the QT interval). Ambulatory blood pressure indicated that mean blood pressure was elevated than before. Myocardial radionuclide scan showed focal myocardial ischemia in left ventricular inferior wall. Pulmonary function tests showed that pulmonary diffusion function was decreased, indicating the possibility of interstitial pneumonia. The patient had no history of coronary heart disease or chest X-ray abnormalities before medication, but had hypertensive medical history for 8 years with good blood pressure control. After withdrawal of antiviral drugs, symptoms such as dry cough, breathing difficulty and T wave inversion were gradually relieved. This case indicated that myocardial ischemia and pulmonary lesions were associated with the application of pegylated interferon ?-2a.
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Pathogenicity of three entomopathogenic fungi to Matsucoccus matsumurae.
PLoS ONE
PUBLISHED: 01-01-2014
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Matsucoccus matsumurae (Kuwana) (Hemiptera: Coccoidea: Matsucoccidae) is an invasive alien species and a destructive pest of two native Chinese pines, Pinus tabulaeformis Carr. and P. massoniana Lamb., throughout the eastern regions of China. The pathogenicity of three entomopathogenic fungi, Lecanicillium lecanii strain V3.4504 and V3.4505, Fusarium incarnatum-equiseti strain HEB01 and Lecanicillium fungicola strain HEB02, against M. matsumurae was tested in four instars, to evaluate their potential as a biological control agent. The results showed that the four strains caused disease and death of the scale insect, among which the L. lecanii strains V3.4504 and V3.4505 displayed stronger virulence than the F. incarnatum-equiseti strains HEB01 and L. fungicola strain HEB02 to M. matsumurae in the 2nd-instar nymphs and the adult females. Furthermore, L. lecanii V3.4505 was most virulent to M. matsumurae. The adult females and the male 3rd-instar nymphs of M. matsumurae were susceptible to L. lecanii V3.4505; the adult females were more susceptible at LT50?=?1.96 than the 3rd-instar nymphs at LT50?=?5.67. The body surface structure, cuticle thickness and wax secretions of M. matsumurae impacted the fungal infection. L. lecanii is a promising biocontrol agent, and newly emerged male 3rd-instar nymphs and adult females are a crucial period of the insect's life cycle for M. matsumurae biocontrol.
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The synergistic effect of homocysteine and lipopolysaccharide on the differentiation and conversion of raw264.7 macrophages.
J Inflamm (Lond)
PUBLISHED: 01-01-2014
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Macrophages play pivotal roles in the progression of atherosclerosis (AS) and their heterogeneous differentiation patterns have been studied extensively. The classical subtype of activated macrophage, M1, promotes the progression of AS. Conversely, the alternative subtype of activated macrophage, M2, is regarded as a repressor of AS. Homocysteine (Hcy) may influence macrophage subtype polarization both in vivo and in vitro. Homocysteinemia (HHcy) is an independent risk factor in coronary heart disease and the effect of Hcy on macrophage differentiation has not been studied until now.
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Perivascular delivery of Notch 1 siRNA inhibits injury-induced arterial remodeling.
PLoS ONE
PUBLISHED: 01-01-2014
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To determine the efficacy of perivascular delivery of Notch 1 siRNA in preventing injury-induced arterial remodeling.
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HTLV-1 Tax-deregulated both autophagy pathway and c-FLIP expression contribute to the resistance against death receptor-mediated apoptosis.
J. Virol.
PUBLISHED: 12-18-2013
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The human T-cell leukemia virus type 1 Tax protein is considered to play a central role in the process that leads to adult T-cell leukemia/lymphoma (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). HTLV-1 Tax-expressing cells show resistance to apoptosis induced by Fas ligand (FasL) and tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL). The regulation of Tax on autophagy pathway is recently reported in HeLa cells and peripheral T cells, but the function and underlying molecular mechanism of the Tax-regulated autophagy are not yet well defined. Here, we report that HTLV-1 Tax deregulates autophagy pathway, which plays a protective role during the death receptor (DR)-mediated apoptosis of human U251 astroglioma cells. The cellular FLICE-inhibitory protein (c-FLIP), which is upregulated by Tax, also contributes to the resistance against DR-mediated apoptosis. Both Tax-induced autophagy and Tax-induced c-FLIP expression require Tax-induced activation of I?B kinases (IKK). Furthermore, Tax-induced c-FLIP expression is regulated through the Tax-IKK-NF-?B signaling pathway, whereas Tax-triggered autophagy depends on the activation of IKK, but not the activation of NF-?B. In addition, DR-mediated apoptosis is correlated with the degradation of Tax, which can be facilitated by the inhibitors of autophagy.
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RH5-Basigin interaction plays a major role in the host tropism of Plasmodium falciparum.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 12-02-2013
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Plasmodium falciparum, the cause of almost all human malaria mortality, is a member of the Laverania subgenus which infects African great apes. Interestingly, Laverania parasites exhibit strict host specificity in their natural environment: P. reichenowi, P. billcollinsi, and P. gaboni infect only chimpanzees; P. praefalciparum, P. blacklocki, and P. adleri are restricted to gorillas, and P. falciparum is pandemic in humans. The molecular mechanism(s) responsible for these host restrictions are not understood, although the interaction between the parasite blood-stage invasion ligand EBA175 and the host erythrocyte receptor Glycophorin-A (GYPA) has been implicated previously. We reexamined the role of the EBA175-GYPA interaction in host tropism using recombinant proteins and biophysical assays and found that EBA175 orthologs from the chimpanzee-restricted parasites P. reichenowi and P. billcollinsi both bound to human GYPA with affinities similar to that of P. falciparum, suggesting that the EBA175-GYPA interaction is unlikely to be the sole determinant of Laverania host specificity. We next investigated the contribution of the recently discovered Reticulocyte-binding protein Homolog 5 (RH5)-Basigin (BSG) interaction in host-species selectivity and found that P. falciparum RH5 bound chimpanzee BSG with a significantly lower affinity than human BSG and did not bind gorilla BSG, mirroring the known host tropism of P. falciparum. Using site-directed mutagenesis, we identified residues in BSG that are responsible for the species specificity of PfRH5 binding. Consistent with the essential role of the PfRH5-BSG interaction in erythrocyte invasion, we conclude that species-specific differences in the BSG receptor provide a molecular explanation for the restriction of P. falciparum to its human host.
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Multi-enzyme co-embedded organic-inorganic hybrid nanoflowers: synthesis and application as a colorimetric sensor.
Nanoscale
PUBLISHED: 11-01-2013
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This study reports a facile method for the synthesis of multi-enzyme co-embedded organic-inorganic hybrid nanoflowers, using glucose oxidase (GOx) and horseradish peroxidase (HRP) as the organic components, and Cu3(PO4)2·3H2O as the inorganic component. The synthesized nanoflowers enable the combination of a two-enzyme cascade reaction in one step, in which the GOx component of the nanoflowers oxidizes glucose to generate H2O2, which then reacts with the adjacent HRP component on the nanoflowers to oxidize the chromogenic substrates, resulting in an apparent color change. Given the close proximity of the two enzyme components in a single nanoflower, this novel sensor greatly reduces the diffusion and decomposition of H2O2, and greatly enhances the sensitivity of glucose detection. Thus, the obtained multi-enzyme co-embedded organic-inorganic hybrid nanoflowers can be unquestionably used as highly sensitive colorimetric sensors for the detection of glucose. Notably, this work presents a very facile route for the synthesis of multi-enzyme co-embedded nanomaterials for the simultaneous catalysis of multi-step cascade enzymatic reactions. Furthermore, it has great potential for application in biotechnology, and biomedical and environmental chemistry.
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Electrolytic synthesis of aqueous aluminum nanoclusters and in situ characterization by femtosecond Raman spectroscopy and computations.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 10-28-2013
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The selective synthesis and in situ characterization of aqueous Al-containing clusters is a long-standing challenge. We report a newly developed integrated platform that combines (i) a selective, atom-economical, step-economical, scalable synthesis of Al-containing nanoclusters in water via precision electrolysis with strict pH control and (ii) an improved femtosecond stimulated Raman spectroscopic method covering a broad spectral range of ca. 350-1,400 cm(-1) with high sensitivity, aided by ab initio computations, to elucidate Al aqueous cluster structures and formation mechanisms in real time. Using this platform, a unique view of flat [Al13(?3-OH)6(?2-OH)18(H2O)24](NO3)15 nanocluster formation is observed in water, in which three distinct reaction stages are identified. The initial stage involves the formation of an [Al7(?3-OH)6(?2-OH)6(H2O)12](9+) cluster core as an important intermediate toward the flat Al13 aqueous cluster.
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Tuning the tribological property with thermal sensitive microgels for aqueous lubrication.
ACS Appl Mater Interfaces
PUBLISHED: 10-25-2013
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Thermoresponsive microgels, poly(N-isopropylacrylamide)-graft-poly(ethylene glycol) (PNIPAAm-g-PEG), were synthesized via emulsifier-free emulsion polymerization and the tribological property as water lubricating additive was studied. The microgels had good thermoresponsive collapse/swelling performance with lower critical solution temperature (LCST) ca. 38.4 °C. The rheological characterization and tribological tests showed that the microgels had a good lubricating performance in aqueous lubrication through interfacial physisorption and hydration lubrication, but the friction coefficient was impacted by temperature (below and above LCST). The tunable thermosensitive tribological property was attributed to the hydrophobic interaction and the enhanced interfacial absorption, which were both triggered by the elevated temperature. Furthermore, in order to avoid the water erosion in aqueous lubrication, the microgels were used together with 1H-benzotriazoles (BTA). Because of the good antifriction and anticorrosion property of BTA and the interplay between microgels and BTA, the microgels/BTA exhibited a synergistic effect in aqueous lubrication and the tribological property was more sensitive around the LCST. The present work is beneficial to understanding the tribological property of responsive microgels in aqueous lubrication and provides a novel approach for achieving low-friction through soft matters.
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Gold-catalyzed hydration of haloalkynes to ?-halomethyl ketones.
J. Org. Chem.
PUBLISHED: 09-05-2013
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A general atom-economical approach for the synthesis of ?-halomethyl ketones is demonstrated through hydration of a wide range of haloalkynes. Other outstanding features include excellent yields from both alkyl- and aryl-substituted haloalkynes and wide functional group tolerance. This protocol is an alternative to conventional ?-halogenation of ketones.
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Distinct broadband third-harmonic generation on a thin amorphous medium-air interface.
Opt Lett
PUBLISHED: 08-31-2013
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We achieve a series of distinct broadband third-harmonic generation (THG) signals at the amorphous glass-air interface attributed to third-order and cascaded third-order nonlinear processes. A novel THG laser sideband arises from cascaded interaction between fundamental pulses and the cascaded four-wave mixing signals. The spatially separated THG sidebands with distinct spectral profiles manifest femtosecond quantum beats. Using a versatile setup with two crossing near-IR pulses temporally delayed to each other, we design an incident pulse polarization control method on the THG sideband lasers and also acquire the low-frequency surface Raman spectrum of the amorphous medium.
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Simazine biodegradation and community structures of ammonia-oxidizing microorganisms in bioaugmented soil: impact of ammonia and nitrate nitrogen sources.
Environ Sci Pollut Res Int
PUBLISHED: 08-21-2013
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The objective of the present study was to investigate the impact of ammonia and nitrate nitrogen sources on simazine biodegradation by Arthrobacter sp. strain SD1 and the community structures of ammonia-oxidizing archaea (AOA) and bacteria (AOB) in non-agricultural soil. Soil microcosms with different treatments were constructed for herbicide biodegradation test. The relative abundance of the strain SD1 and the structures of AOA and AOB communities were assessed using quantitative PCR (q-PCR) and terminal restriction fragment length polymorphism (TRFLP), respectively. The co-existence of two inorganic nitrogen sources (ammonia and nitrate) had certain impact on simazine dissipation by the strain SD1. Bioaugmentation could induce a shift in the community structures of both AOA and AOB, but AOA were more responsive. Nitrogen application had significant impacts on AOA and AOB communities in bioaugmented soils. Moreover, in non-bioaugmented soil, the community structure of AOA, instead of AOB, could be quickly recovered after herbicide application. This study could add some new insights towards the impacts of nitrogen sources on s-triazine bioremediation and ammonia-oxidizing microorganisms in soil ecosystem.
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One-Year Outcomes from an All-Comers Chinese Population of Patients Implanted With the Resolute Zotarolimus-Eluting Stent.
Am. J. Cardiol.
PUBLISHED: 07-31-2013
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The RESOLUTE China Registry is a prospective, multicenter, all-comers, observational study of patients in China implanted with the Resolute zotarolimus-eluting stent (R-ZES). R-ZES was commercially available before the enrollment began. All patients suitable for R-ZES implantation according to applicable guidelines were candidates for enrollment at 30 centers and were treated per standard hospital practice. Dual antiplatelet therapy (DAPT) was prescribed for a minimum of 6 months per current European Society of Cardiology guidelines and the device instructions for use. There were 1,800 patients enrolled with a mean age of 61.3 ± 10.9 years, 76% of patients were men, and 61% had complex disease. DAPT use was 94% at 1 year. Target lesion failure (cardiac death, target vessel myocardial infarction, or clinically driven target lesion revascularization) at 1 year was 3.5% (95% confidence interval 2.7% to 4.5%). The rate of cardiac death was 0.6%, target vessel myocardial infarction 2.3%, and clinically driven target lesion revascularization 0.9%. The 1-year rate of definite or probable stent thrombosis was 0.5% (8 of 1,750); 0.4% (7 of 1,750) occurred early (0 to 30 days) and 1 event occurred late (1 to 12 months). One stent thrombosis occurred in a patient who had an interruption of DAPT within the first month; all other stent thromboses occurred while on DAPT. Outcomes did not differ significantly between monitored and unmonitored patients (difference in target lesion failure, p = 0.264). In conclusion, the RESOLUTE China Registry confirms the safety and effectiveness of R-ZES in a large real-world Chinese population.
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CpG oligodeoxynucleotide induces bone marrow precursor cells into myeloid-derived suppressor cells.
Mol Med Rep
PUBLISHED: 07-17-2013
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Dendritic cells (DCs) and myeloid-derived suppressor cells (MDSCs) perform a number of functions in different immunological settings. In standard in vitro experiments, DCs are produced from mouse bone marrow (BM) cells in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL-4. Our previous study demonstrated that BM precursor cells could differentiate into MDSCs when co-cultured with poly (I:C). In the present study, BM precursor cells cultured in GM-CSF and IL-4 were treated with CpG oligodeoxynucleotide (CpG ODN). We observed that Gr1+CD11b+ cells exhibiting MDSC functions accumulated in the co-culture system. A similar phenomenon was also observed in Listeria monocytogenes-infected mice. In conclusion, we demonstrated that prolonged CpG ODN stimulation could inhibit the development of DCs and induce the differentiation of BM precursor cells into MDSCs.
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A natural product telomerase activator as part of a health maintenance program: metabolic and cardiovascular response.
Rejuvenation Res
PUBLISHED: 07-02-2013
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A short average telomere length is associated with low telomerase activity and certain degenerative diseases. Studies in animals and with human cells confirm a causal mechanism for cell or tissue dysfunction triggered by critically short telomeres, suggesting that telomerase activation may be an approach to health maintenance. Previously, we reported on positive immune remodeling in humans taking a commercial health maintenance program, PattonProtocol-1, composed of TA-65® (a natural product-derived telomerase activator) and other dietary supplements. In over a 5-year period and an estimated 7000 person-years of use, no adverse events or effects have been attributed to TA-65 by physicians licensed to sell the product. Here we report on changes in metabolic markers measured at baseline (n=97-107 subjects) and every 3-6 months (n=27-59 subjects) during the first 12 months of study. Rates of change per year from baseline determined by a multi-level model were -3.72?mg/dL for fasting glucose (p=0.02), -1.32?mIU/mL for insulin (p=0.01), -13.2 and -11.8?mg/dL for total cholesterol and low-density lipoprotein cholesterol (LDL-C) (p=0.002, p=0.002, respectively), -17.3 and -4.2?mmHg for systolic and diastolic blood pressure (p=0.007 and 0.001, respectively), and -3.6??mole/L homocysteine (p=0.001). In a subset of individuals with bone mineral density (BMD) measured at baseline and 12 months, density increased 2.0% in the spine (p=0.003). We conclude that in addition to apparent positive immune remodeling, PattonProtocol-1 may improve markers of metabolic, bone, and cardiovascular health.
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Investigation of biological cell-protein interactions using SPR sensor through laser scanning confocal imaging-surface plasmon resonance system.
Spectrochim Acta A Mol Biomol Spectrosc
PUBLISHED: 06-26-2013
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A new method for investigating biological cell-protein interactions was developed by using a laser scanning confocal imaging-surface plasmon resonance (LSCI-SPR) system. Mouse normal IgG was modified on the SPR chip. The suspension mouse lymphocyte cancer cells (L5178Y cells) labeled by Hoechst33342 freely flowed into the surface of the SPR sensor chip. By changing the concentration of the cells, the fluorescence images and the SPR signal were synchronously recorded in real time. The red fluorescence points in the imaging region increased with increase in the concentration of the mouse lymphocyte cancer cells and fit well with the change in the SPR signal. Different suspending cells were chosen to investigate cell-protein interactions through antigen-antibody reactions on the biological cell surfaces through binding detection. This method has potential application in cell biology and pharmacology.
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Coumarin- and rhodamine-fused deep red fluorescent dyes: synthesis, photophysical properties, and bioimaging in vitro.
J. Org. Chem.
PUBLISHED: 06-07-2013
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A series of deep red fluorescent dyes (CR1 to CR3) was developed via introduction of a coumarin moiety into the rhodamine molecular skeleton. The novel dyes possessed the individual advantages of coumarin and rhodamine derivatives, and the emission wavelength was extended to the deep red region (>650 nm) due to the extension of fused-ring conjugate structure simultaneously. To illustrate its value, we designed and conveniently synthesized a series of novel deep red bioimaging dyes (CR1E to CR3E) by esterification of CR1 to CR3, which could selectively stain mitochondria. They were superior to the MitoTrackers for mitochondrial staining in terms of large Stokes shift, excellent contrast for imaging, high photostability, and low cytotoxicity. Furthermore, the fluorescence of the coumarin moiety and rhodamine-like fluorophore could be switched like classical rhodamine. Thus, they could be used as an effective platform in constructing fluorescence sensors. Based on this fact, we constructed a novel ratiometric sensor (CR1S) for Hg(2+) with good selectivity that could be successfully applied to the imaging of Hg(2+) in living A549 cells. This design strategy is straightforward and adaptable to various deep red dyes and sensing platforms by simply introducing different fluorophores.
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Cascaded four-wave mixing for broadband tunable laser sideband generation.
Opt Lett
PUBLISHED: 06-01-2013
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We demonstrate the versatile broadband wavelength tunability of frequency upconverted multicolor cascaded four-wave-mixing (CFWM) signals spanning the continuous wavelength range from UV to near IR in a thin type-I BBO crystal using 35 fs, 800 nm fundamental and chirped IR supercontinuum white light pulses. Two sets of spatially dispersed CFWM laser sidebands are concomitantly generated from two incident pulses as well as their second-harmonic-generation and sum-frequency-generation pulses in a crossing geometry. The tunable cascaded signals with ultrabroad bandwidth can be readily achieved via spatially rotating the BBO crystal to different phase-matching conditions and temporally varying the time delay between the two incident near-IR pulses.
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Early time excited-state structural evolution of pyranine in methanol revealed by femtosecond stimulated Raman spectroscopy.
J Phys Chem A
PUBLISHED: 05-17-2013
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To understand chemical reactivity of molecules in condensed phase in real time, a structural dynamics technique capable of monitoring molecular conformational motions on their intrinsic time scales, typically on femtoseconds to picoseconds, is needed. We have studied a strong photoacid pyranine (8-hydroxypyrene-1,3,6-trisulfonic acid, HPTS, pK(a)* ? 0) in pure methanol and observed that excited-state proton transfer (ESPT) is absent, in sharp contrast with our previous work on HPTS in aqueous solutions wherein ESPT prevails following photoexcitation. Two transient vibrational marker bands at ~1477 (1454) and 1532 (1528) cm(-1) appear in CH3OH (CD3OD), respectively, rising within the instrument response time of ~140 fs and decaying with 390-470 (490-1400) fs and ~200 ps time constants in CH3OH (CD3OD). We attribute the mode onset to small-scale coherent proton motion along the pre-existing H-bonding chain between HPTS and methanol, and the two decay stages to the low-frequency skeletal motion-modulated Franck-Condon relaxation within ~1 ps and subsequent rotational diffusion of H-bonding partners in solution before fluorescence. The early time kinetic isotope effect (KIE) of ~3 upon methanol deuteration argues active proton motions particularly within the first few picoseconds when coherent skeletal motions are underdamped. Pronounced quantum beats are observed for high-frequency modes consisting of strong phenolic COH rocking (1532 cm(-1)) or H-out-of-plane wagging motions (952 cm(-1)) due to anharmonic coupling to coherent low-frequency modes impulsively excited at ca. 96, 120, and 168 cm(-1). The vivid illustration of atomic motions of HPTS in varying H-bonding geometry with neighboring methanol molecules unravels the multidimensional energy relaxation pathways immediately following photoexcitation, and provides compelling evidence that, in lieu of ESPT, the photoacidity of HPTS promptly activates characteristic low-frequency skeletal motions to search phase space mainly concerning the phenolic end and to efficiently dissipate vibrational energy via skeletal deformation and proton shuttling motions within the intermediate, relatively confined excited-state HPTS-methanol complex on a solvent-dependent dynamic potential energy surface.
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Thermo-responsive hollow silica microgels with controlled drug release properties.
Colloids Surf B Biointerfaces
PUBLISHED: 05-14-2013
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Thermo-responsive hollow silica microgels (THSMGs) consisting of a hollow core, an intermediate silica supporting layer and a smart polymer gel corona were fabricated via organic-inorganic hybridization. Hollow silica particles and PNIPAAm microgels were successfully combined by utilizing the cross-linking reaction between 3-(trimethoxysilyl) propyl methacrylate (TMSPMA) and silanol groups on the silica surface, and then the copolymerization of TMSPMA and N-isopropylacrylamide (NIPAAm). The morphology and chemical composition were systematically examined by field emission scanning electron microscope (FESEM), transmission electron microscope (TEM), energy dispersive X-ray spectroscopy (EDS) and the Brunauer-Emmett-Teller (BET) measurement. The thermo-responsive phase transition behavior was investigated by the determination of the lower critical solution temperature (LCST), and particle size measurement using dynamic light scattering. THSMGs remain porous even after the coverage of PNIPAAm gels, and also have obvious hydrophilic/hydrophobic transition property and good swelling/collapse capability in spite of the rigid silica layer. The results of in vitro cytotoxicity evaluation and Rhodamine B (RHB) release study demonstrated that THSMGs have good biocompatibility, and achieve a thermo-responsive controlled-release behavior. The prepared THSMGs show considerable potential for applications as targeted and ambient temperature responsive drug delivery system.
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Monophosphoryl lipid A induces bone marrow precursor cells to differentiate into myeloid-derived suppressor cells.
Mol Med Rep
PUBLISHED: 04-08-2013
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Myeloid-derived suppressor cells (MDSCs) and dendritic cells (DCs) are important in the immune response. In vitro, DCs are derived from myeloid precursors by stimulation with granulocyte macrophage colony?stimulating factor and interleukin?4. Previous studies demonstrated that lipopolysaccharide (LPS) in combination with interferon?? inhibited DC development but enhanced MDSC functions. Monophosphoryl lipid A (MPL), derived from LPS, is a unique immunomodulatory Toll?like receptor 4 agonist. In the present study, MPL was used to disturb DC differentiation from myeloid precursors and it was observed that prolonged stimulation with MPL led to the accumulation of MDSCs in vitro and in vivo. In conclusion, it was demonstrated that stimulation by MPL from the beginning of cell differentiation disturbed the development of DCs and led to the accumulation of MDSCs.
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Plasmodium falciparum-like parasites infecting wild apes in southern Cameroon do not represent a recurrent source of human malaria.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 04-08-2013
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Wild-living chimpanzees and gorillas harbor a multitude of Plasmodium species, including six of the subgenus Laverania, one of which served as the progenitor of Plasmodium falciparum. Despite the magnitude of this reservoir, it is unknown whether apes represent a source of human infections. Here, we used Plasmodium species-specific PCR, single-genome amplification, and 454 sequencing to screen humans from remote areas of southern Cameroon for ape Laverania infections. Among 1,402 blood samples, we found 1,000 to be Plasmodium mitochondrial DNA (mtDNA) positive, all of which contained human parasites as determined by sequencing and/or restriction enzyme digestion. To exclude low-abundance infections, we subjected 514 of these samples to 454 sequencing, targeting a region of the mtDNA genome that distinguishes ape from human Laverania species. Using algorithms specifically developed to differentiate rare Plasmodium variants from 454-sequencing error, we identified single and mixed-species infections with P. falciparum, Plasmodium malariae, and/or Plasmodium ovale. However, none of the human samples contained ape Laverania parasites, including the gorilla precursor of P. falciparum. To characterize further the diversity of P. falciparum in Cameroon, we used single-genome amplification to amplify 3.4-kb mtDNA fragments from 229 infected humans. Phylogenetic analysis identified 62 new variants, all of which clustered with extant P. falciparum, providing further evidence that P. falciparum emerged following a single gorilla-to-human transmission. Thus, unlike Plasmodium knowlesi-infected macaques in southeast Asia, African apes harboring Laverania parasites do not seem to serve as a recurrent source of human malaria, a finding of import to ongoing control and eradication measures.
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Adipose tissue-specific PPAR? gene targeting.
Methods Mol. Biol.
PUBLISHED: 03-30-2013
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The nuclear receptor peroxisome proliferator activated receptor gamma (PPAR?) is most abundantly expressed in adipose tissue and has been shown to play imperative roles in controlling adipogenesis and lipogenesis in cultured cell systems in vitro as well as in mice and humans. However, it is unclear how important the role this receptor plays in regulating physiological functions of mature adipocytes in vivo. The Cre-loxP gene targeting strategy is employed to specifically disrupt PPAR? in mature adipocytes in mice. In this chapter, I will describe generation of "floxed" PPAR? mice, which bear loxP sequences in the introns of PPAR? gene locus flanking the coding exons 1 and 2 of PPAR? and creation of the aP2-Cre transgenic mice, which express Cre recombinase under the control of the promoter of adipocyte fatty acid binding protein (aP2). Crossing of the two mouse lines results in deletion of PPAR? gene only in differentiated adipocytes in Cre positive mice.
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Expression of interleukin (IL)-10, IL-17A and IL-22 in serum and sputum of stable chronic obstructive pulmonary disease patients.
COPD
PUBLISHED: 03-28-2013
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Interleukin (IL)-17A, IL-22 and IL-10 have been implicated in the development of chronic obstructive pulmonary disease (COPD), but their expression in COPD is uncertain. Here we investigate the expression of IL-17A, IL-22 and IL-10 in the serum and sputum of COPD patients. Blood samples and induced sputum samples were collected from 94 patients with COPD, 23 healthy smokers, and 22 healthy control non-smokers. IL-17A, IL-22 and IL-10 were measured by enzyme-linked immunosorbent assay (ELISA). We found that: 1) serum and sputum IL-17A were higher in COPD compared to healthy smokers and non-smokers; 2) serum IL-17A increased with COPD stages, it was inversely correlated with percentage of forced expiratory volume in the first second (FEV1%) reference and positively correlated with C-reactive protein (CRP), Sputum IL-17A levels in the severe COPD patients were positively correlated with sputum neutrophils, and reversely correlated with sputum macraphages (p < 0.01); 3) serum and sputum IL-22 were significantly higher in COPD and healthy smokers than those in the non-smoker group, sputum IL-22 was similar in severe COPD (stage III and IV), which were higher than those in the other groups (p < 0.05); and, 4) serum and sputum IL-10 were similiar in COPD and healthy smokers, which were decreased compared to non-smokers. These data suggest that the increased level of IL-17A in serum and sputum plays important roles in the pathogenesis of COPD. The increased sputum IL-22 might also play important roles in the pathogenesis of COPD, while IL-10 secretion might be not only affected by COPD but also by cigarette smoke.
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Ultrasensitive and selective gold film-based detection of mercury (II) in tap water using a laser scanning confocal imaging-surface plasmon resonance system in real time.
Biosens Bioelectron
PUBLISHED: 03-26-2013
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An ultrasensitive and selective detection of mercury (II) was investigated using a laser scanning confocal imaging-surface plasmon resonance system (LSCI-SPR). The detection limit was as low as 0.01ng/ml for Hg(2+) ions in ultrapure and tap water based on a T-rich, single-stranded DNA (ssDNA)-modified gold film, which can be individually manipulated using specific T-Hg(2+)-T complex formation. The quenching intensity of the fluorescence images for rhodamine-labeled ssDNA fitted well with the changes in SPR. The changes varied with the Hg(2+) ion concentration, which is unaffected by the presence of other metal ions. The coefficients obtained for ultrapure and tap water were 0.99902 and 0.99512, respectively, for the linear part over a range of 0.01-100ng/ml. The results show that the double-effect sensor has potential for practical applications with ultra sensitivity and selectivity, especially in online or real-time monitoring of Hg(2+) ions pollution in tap water with the further improvement of portable LSCI-SPR instrument.
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Copolythiophene-derived colorimetric and fluorometric sensor for lysophosphatidic acid based on multipoint interactions.
ACS Appl Mater Interfaces
PUBLISHED: 03-18-2013
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3-Phenylthiophene-based water-soluble copolythiophenes (CPT9) were designed for colorimetric and fluorometric detection of lysophosphatidic acid (LPA) based on electrostatic interaction, hydrophobic interaction, and hydrogen bonding. Other negatively charged species gave nearly no interference, and the detection limit reached to 0.6 ?M, which is below the requisite detection limits for LPA in human plasma samples. The appealing performance of CPT9 was demonstrated to originate from the multipoint interaction-induced conformational change of conjugated backbone and weakened electron transfer effect. To our best knowledge, this is the first polythiophene based optical sensor which displays emission peak red-shift followed with fluorescence enhancement.
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Presence, diversity and enumeration of functional genes (bssA and bamA) relating to toluene degradation across a range of redox conditions and inoculum sources.
Biodegradation
PUBLISHED: 02-27-2013
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The study investigates two functional genes for toluene degradation across three redox conditions (nitrate and sulfate amended and methanogenic). The genes targeted include benzylsuccinate synthase ?-subunit (bssA) and a gene recently identified as being a strong indicator of anaerobic aromatic degradation, called 6-oxocylcohex-1-ene-1-carbonyl-CoA hydrolase (bamA). In all, sixteen different anaerobic toluene degrading microcosms were investigated using several primers sets targeting bssA and one primer set targeting bamA. One bssA primer set (7772f/8546r) was the most successful in producing a strong amplicon (eight from sixteen) with the other bssA primers sets producing strong amplicons in six or less samples. In contrast, the bamA primer set (bam-sp9 and bam-asp1) produced a strong amplicon in DNA extracted from all except one microcosm. Partial bssA and bamA sequences were obtained for a number of samples and compared to those available in GenBank. The partial bssA sequences (from nitrate amended and methanogenic microcosms) were most similar to Thauera sp. DNT-1, Thauera aromatica, Aromatoleum aromaticum EbN1 and bssA clones from a study involving sulfate reducing toluene degradation. The bamA sequences obtained could be placed into five previously defined clades (bamA-clade 1, Georgfuchsia/Azoarcus, Magnetospirillum/Thauera Syntrophus and Geobacter clades), with the placement generally depending on redox conditions. Gene numbers were also correlated with toluene degradation and the final gene number for both genes differed considerably between the range of redox conditions. The work is the first in depth investigation of bamA diversity over a range of redox conditions and inoculum sources.
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