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Find video protocols related to scientific articles indexed in Pubmed.
STIM1- and Orai1-mediated Ca2+ oscillation orchestrates invadopodium formation and melanoma invasion.
J. Cell Biol.
PUBLISHED: 11-19-2014
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Ca(2+) signaling has been increasingly implicated in cancer invasion and metastasis, and yet, the underlying mechanisms remained largely unknown. In this paper, we report that STIM1- and Orai1-mediated Ca(2+) oscillations promote melanoma invasion by orchestrating invadopodium assembly and extracellular matrix (ECM) degradation. Ca(2+) oscillation signals facilitate invadopodial precursor assembly by activating Src. Disruption of Ca(2+) oscillations inhibited invadopodium assembly. Furthermore, STIM1 and Orai1 regulate the proteolysis activity of individual invadopodia. Mechanistically, Orai1 blockade inhibited the recycling of MT1-matrix metalloproteinase (MMP) to the plasma membrane and entrapped MT1-MMP in the endocytic compartment to inhibit ECM degradation. STIM1 knockdown significantly inhibited melanoma lung metastasis in a xenograft mouse model, implicating the importance of this pathway in metastatic dissemination. Our findings provide a novel mechanism for Ca(2+)-mediated cancer cell invasion and shed new light on the spatiotemporal organization of store-operated Ca(2+) signals during melanoma invasion and metastasis.
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T-bet Is Critical for the Development of Acute Graft-versus-Host Disease through Controlling T Cell Differentiation and Function.
J. Immunol.
PUBLISHED: 11-19-2014
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T-bet is a master regulator for IFN-? production and Th1 differentiation. We evaluated the roles of T-bet and IFN-? in T cell responses in acute graft-versus-host disease (GVHD) and found that T-bet(-/-) T cells induced significantly less GVHD compared with wild-type or IFN-?(-/-) counterparts in both MHC-mismatched and MHC-matched but minor histocompatibility Ag-mismatched models driven by CD4 T cells. T-bet(-/-), but not IFN-?(-/-), CD4 T cells had a markedly reduced ability to cause tissue damage in liver and gut. This distinct outcome is reflected by the differential gene expression on donor CD4 T cells deficient for T-bet or IFN-?. At mRNA and protein levels, we defined several T-bet-dependent molecules that may account for the impaired ability of T-bet(-/-) T cells to migrate into target organs and to produce Th1-related cytokines. Moreover, these molecules were independent of either endogenous IFN-?, such as CXCR3 and programmed death-1, or systematic IFN-?, such as NKG2D, I-A(b), and granzyme B. Although both T-bet(-/-) and IFN-?(-/-) CD4 T cells are prone to differentiate into Th17 cells, polarized Th17 cells deficient for T-bet but not for IFN-? had a significantly reduced ability to cause GVHD. Finally, T-bet(-/-) T cells had a compromised graft-versus-leukemia effect, which could be essentially reversed by neutralization of IL-17 in the recipients. We conclude that T-bet is required for Th1 differentiation and migration, as well as for optimal function of Th17 cells. Thus, targeting T-bet or regulating its downstream effectors independent of IFN-? may be a promising strategy to control GVHD in the clinic.
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Plastid-LCGbase: a collection of evolutionarily conserved plastid-associated gene pairs.
Nucleic Acids Res.
PUBLISHED: 11-08-2014
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Plastids carry their own genetic material that encodes a variable set of genes that are limited in number but functionally important. Aside from orthology, the lineage-specific order and orientation of these genes are also relevant. Here, we develop a database, Plastid-LCGbase (http://lcgbase.big.ac.cn/plastid-LCGbase/), which focuses on organizational variability of plastid genes and genomes from diverse taxonomic groups. The current Plastid-LCGbase contains information from 470 plastid genomes and exhibits several unique features. First, through a genome-overview page generated from OrganellarGenomeDRAW, it displays general arrangement of all plastid genes (circular or linear). Second, it shows patterns and modes of all paired plastid genes and their physical distances across user-defined lineages, which are facilitated by a step-wise stratification of taxonomic groups. Third, it divides the paired genes into three categories (co-directionally-paired genes or CDPGs, convergently-paired genes or CPGs and divergently-paired genes or DPGs) and three patterns (separation, overlap and inclusion) and provides basic statistics for each species. Fourth, the gene pairing scheme is expandable, where neighboring genes can also be included in species-/lineage-specific comparisons. We hope that Plastid-LCGbase facilitates gene variation (insertion-deletion, translocation and rearrangement) and transcription-level studies of plastid genomes.
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A multiscale approach to the adsorption of core-shell nanoparticles at fluid interfaces.
Soft Matter
PUBLISHED: 11-06-2014
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Self-assembly of colloidal particles at liquid-liquid interfaces is a process with great potential for the creation of controlled structures, due to the trapping of the particles in the plane of the interface combined with their lateral mobility. Here we present a multiscale characterisation of the adsorption and interfacial behaviour of core-shell iron oxide-poly(ethylene glycol) nanoparticles at a water-n-decane interface using three complementary, in situ, methods, which span many different length scales. First, dynamic interfacial measurements are taken to follow the adsorption of particles from the bulk aqueous phase to the interface. The mechanical properties of the interface are then probed using micron-sized tracers in probe-particle tracking and nano-tracers in fluorescence correlation spectroscopy. The results show that the rate of particle adsorption to the interface scales with the square of bulk concentration, as predicted by a recent model. In addition, we show that despite full monolayers of nanoparticles forming, the interface remains unexpectedly fluid, with only a slowing of tracer particle mobility but no evidence of interface jamming as seen for hard nanoparticles. Our results illustrate that nanoparticles stabilised by soft, extended polymeric shells, display distinct features at fluid interfaces that can be harnessed for the fabrication of functional materials.
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[Impact of miR-148a on the proliferation of gastric carcinoma MKN45 cells and its mechanism].
Zhonghua Wei Chang Wai Ke Za Zhi
PUBLISHED: 10-25-2014
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To investigate the influence of miR-148a on cell proliferation of human gastric cancer cell lines MKN45.
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Effects of azimuthal angles on laser interference lithography.
Appl Opt
PUBLISHED: 10-17-2014
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This paper discusses the effects of azimuthal angles on two-, three-, and four-beam laser interference. In two- or three-beam laser interference, periodic surface structures of lines or dots were obtained. In four-beam laser interference with the polarization mode of TE-TM-TE-TM, the modulation in a particular direction was formed and calculated. In the work, a He-Ne laser system was used to simulate two-, three-, and four-beam laser interference, and the interference pattern was detected by a CCD. A high-power Nd:YAG laser interference lithography system was set up to pattern silicon wafers. In the experiments, one azimuthal angle was changed every time to form interference patterns when polarization states were fixed and incident angles were equal. The experimental results have shown that the azimuthal angle affects the periods and feature sizes of the interference patterns and the fabricated surface structures, which are in accordance with the theoretical and computer simulation results.
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ZnO-Functionalized Upconverting Nanotheranostic Agent: Multi-Modality Imaging-Guided Chemotherapy with On-Demand Drug Release Triggered by pH.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 09-26-2014
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Limited therapeutic efficiency and severe side effects in patients are two major issues existing in current chemotherapy of cancers in clinic. To design a proper theranostic platform seems thus quite needed to target cancer cells accurately by bioimaging and simultaneously release drugs on demand without premature leakage. A novel ZnO-functionalized upconverting nanotheranostic platform has been fabricated for clear multi-modality bioimaging (upconversion luminescence (UCL), computed tomography (CT), and magnetic resonance imaging (MRI)) and specific pH-triggered on-demand drug release. In our theranostic platform multi-modality imaging provides much more detailed and exact information for cancer diagnosis than single-modality imaging. In addition, ZnO can play the role of a "gatekeeper" to efficiently block the drug in the mesopores of the as-prepared agents until it is dissolved in the acidic environment around tumors to realize sustained release of the drug. More importantly, the biodegradable ZnO, which is non-toxic against normal tissues, endows the as-prepared agents with high therapeutic effectiveness but very low side effects. These findings are of great interests and will inspire us much to develop novel effective imaging-guided on-demand chemotherapies in cancer treatment.
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Perturbations in Intracellular Ca2+ Handling in Skeletal Muscle in the G93A*SOD1 Mouse Model of Amyotrophic Lateral Sclerosis.
Am. J. Physiol., Cell Physiol.
PUBLISHED: 09-26-2014
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Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disease characterized by skeletal muscle atrophy and weakness, ultimately leading to respiratory failure. The purpose of this study was to assess changes in skeletal muscle excitation-contraction (e-c) coupling and intracellular Ca(2+) handling during disease progression in the G93A*SOD1 mouse model of ALS. To assess e-c coupling, single muscle fibres were electrically stimulated (10-150Hz) and intracellular free Ca(2+) concentration assessed using Fura-2. There were no differences in peak Fura-2 ratio at any stimulation frequency at 70d (early pre-symptomatic). However, at 90d (late pre-symptomatic) and 120-140d (symptomatic) Fura-2 ratio was increased at 10Hz in G93A*SOD1 compared to control (CON) fibres (0.670±0.02 vs. 0.585±0.02 for 120-140d; p<0.05). There was also a significant increase in resting Fura-2 ratio at 90d (0.351±0.008 vs. 0.390±0.009 in CON and ALS; p<0.05) and 120-140d (0.374±0.001 vs. 0.415±0.003 in CON vs. ALS; p<0.05), representing a 2-3 -fold increase in resting Ca2+. These increases in intracellular Ca(2+) were associated with reductions in the Sarcoplasmic/Endoplasmic Reticulum Ca2+ ATPase proteins SERCA1 (45% and 16% of CON) and SERCA2 (56% and 11% of CON) and parvalbumin (75 and 40% of CON) at 90d and 120-140d, respectively. There was no change in dihydropyridine receptor/L-type Ca(2+) channel at any age. Overall, these data demonstrate well-preserved e-c coupling but elevations in intracellular Ca(2+) due to impaired Ca(2+) clearance. These data suggest that elevations in cellular Ca(2+) precede and may contribute to muscle weakness during disease progression in ALS mice.
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[Study on hearing impairment at high frequency among the flight cadets].
Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi
PUBLISHED: 09-25-2014
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To study the incidence of hearing loss at high frequency and the related influence factors among the flight cadets.
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[Incidence and influencing factors of distal external iliac lymph node metastasis in early cervical cancer].
Zhonghua Zhong Liu Za Zhi
PUBLISHED: 09-23-2014
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The distal external iliac lymph nodes are located along the external iliac artery between the deep circumflex iliac vein and the inguinal canal. Our study aimed to investigate the incidence of metastasis in distal external iliac lymph nodes and its association with clinicopathological factors in patients with early stage cervical cancer, and to determine the role of distal external iliac lymph nodes dissection in the surgery.
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FHL2-driven molecular network mediated Septin2 knockdown inducing apoptosis in mesangial cell.
Proteomics
PUBLISHED: 09-22-2014
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The apoptosis of mesangial cells (MCs) plays a critical role in the pathological progress of MesPGN. Septin2, a filamentous GTPase, is implicated in the apoptotic progress of MCs in the rat MesPGN model. However, the molecular mechanism of SEPT2 in MCs apoptosis is not clear. Here, we present the FHL2-driven molecular network as the main mechanism of SEPT2-mediated rat primary MCs apoptosis. First, we proved that the expression of FHL2 and Septin2 were closely related with MCs apoptosis in anti-Thy1 nephritis model. Then, it was found that FHL2 was a new interaction protein of Septin2 and Septin2 knockdown could induce MC apoptosis by FHL2-mediatied signal pathways including p-ERK1 and p-AKT. We applied label-Free quantitative proteomics to identify the mechanism of Septin2/FHL2-regulated apoptosis. Bioinformatics analysis revealed that FHL2-driven molecular network composed of biological functions including glycolysis, oxidative stress, ribonucleotide metabolism, actin cytoskeleton regulation, and signaling pathway, was the main mechanism of SETP2-mediated apoptosis. Furthermore, we showed that the effect of Septin2 knockdown on MC apoptosis could be alleviated by the overexpression of FHL2. Overall, this study illustrated the FHL2-driven molecular network controlling SEPT2-mediated apoptosis in MCs and their potential roles in mesangial proliferative nephritis.
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Revision of Strombidium paracalkinsi (Ciliophora: Oligotrichea: Oligotrichia), with comparison of strombidiids bearing thigmotactic membranelles.
J. Eukaryot. Microbiol.
PUBLISHED: 09-16-2014
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This study analyses the morphological characters of Strombidium paracalkinsi, a species bearing thigmotactic membranelles, collected from Jangmok Bay at the southern coast of Korea. The small subunit ribosomal RNA (SSU rRNA) gene of S. paracalkinsi was sequenced for the first time. By a combination of characters, the thigmotactic membranelles of Strombidium paracalkinsi differ from the thigmotactic membranelles of other strombidiids. They are 1) positioned on dorsal side; 2) contiguous with three membranelles of the adoral zone, but separated by non-ciliated portions of the polykinetids and 3) composed of two rows of kinetids. Except for the thigmotactic membranelles, the morphology of Strombidium paracalkinsi conforms to the diagnosis of the genus Strombidium. Our phylogenetic tree confirms the non-monophyly of the genus Strombidium. The thigmotactic membranelles are a promising feature for a future split of the genus Strombidium, but require further studies, especially on Strombidium calkinsi Fauré-Fremiet 1932. This article is protected by copyright. All rights reserved.
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[A quantitative detection of Poincare scatter for T-wave alternans].
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi
PUBLISHED: 09-16-2014
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To study the quantitative detection method of T-wave alternans (TWA), we analyzed the relationship between the graphic mode of Poincare scatter and TWA, and proposed 'horizontal search algorithm' to complete graphic processing. Then, based on the shape of Poincare scatter, we took Axial_ratio as the final index. Through Matlab simulation, Axial_ratio was compared with the results of spectral method (SM) and appropriate threshold value was selected to recognize the TWA. The results showed that Axial_ratio could accurately detect the TWA.
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Presence of qnr, aac(6')-Ib, qepA, oqxAB, and mutations in gyrase and topoisomerase in nalidixic acid-resistant Salmonella isolates recovered from retail chicken carcasses.
Foodborne Pathog. Dis.
PUBLISHED: 09-05-2014
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Four hundred sixty-two nalidixic acid- and/or ciprofloxacin-resistant Salmonella isolates were examined for presence of quinolone-resistance mechanisms. A total of 339 amino acid substitutions were identified in GyrA (204) and ParC (135). Ser83Phe/Asp87Gly (29.4%) were most commonly detected in GyrA in 136 isolates, and to a lesser extent of Asp87Asn (22.8%), Asp87Gly (19.1%), Ser83Phe/Asp87Asn (19.1%), and Ser83Tyr (5.1%). Ser80Arg (97.0%) was detected in ParC in 132 isolates. Simultaneous mutations in GyrA and ParC (n=109) were commonly detected to be Ser83Phe/Asp87Gly(GyrA)-Ser80Arg(ParC) (35.8%), Asp87Asn(GyrA)-Ser80Arg(ParC) (22.9%), and Ser83Phe/Asp87Asn(GyrA)-Ser80Arg(ParC) (21.1%). qnrA, qnrB, qnrS, aac(6')-Ib, qepA, and oqxAB were detected in 52 (11.3%), 64 (13.9%), 11(2.4%), 107 (23.2%), 6 (1.3%), and 194 (42.0%) of 462 isolates, respectively. Isolates carried more qnr, aac(6')-Ib, qepA, and oqxAB genes, and amino acid substitution in GyrA and ParC was more resistant to nalidixic acid and fluoroquinolones.
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JNK and Akt signaling pathways regulating TNF-?-induced IL-32 expression in human lung fibroblasts: implications in airway inflammation.
Immunology
PUBLISHED: 08-26-2014
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Airway inflammatory diseases such as chronic obstructive pulmonary disease (COPD) and asthma are associated with elevated expression of IL-32, a recently described cytokine that appears to play a critical role in inflammation. However, thus far, the regulation of pulmonary IL-32 production has not been fully established. We examined the expression of IL-32 by TNF-? in primary human lung fibroblasts. Human lung fibroblasts were cultured in the presence or absence of TNF-? and/or other cytokines/TLR ligands or various signaling molecule inhibitors to analyze the expression of IL-32 by quantitative RT-PCR and enzyme-linked immunosorbent assay. Next, activation of Akt and JNK signaling pathways were investigated by Western blot. IL-32 mRNA of 4 spliced isoforms (?, ?, ?, and ?) was up-regulated upon TNF-? stimulation, which was associated with a significant IL-32 protein release from TNF-?-activated human lung fibroblasts. The combination of IFN-? and TNF-? induced enhanced IL-32 release in human lung fibroblasts, whereas IL-4, IL-17A, IL-27 and TLR ligands did not alter IL-32 release in human lung fibroblasts either alone, or in combination with TNF-?. Furthermore, the activation of Akt and JNK pathways regulated TNF-?-induced IL-32 expression in human lung fibroblasts, and inhibition of the Akt and JNK pathways was able to suppress the increased release of IL-32 to nearly the basal level. These data suggest that TNF-? may be involved in airway inflammation via the induction of IL-32 by activating Akt and JNK signaling pathways. Therefore, the TNF-?/IL-32 axis may be a potential therapeutic target for airway inflammatory diseases. This article is protected by copyright. All rights reserved.
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Smilacis Glabrae Rhizoma Reduces Oxidative Stress Caused by Hyperuricemia via Upregulation of Catalase.
Cell. Physiol. Biochem.
PUBLISHED: 08-18-2014
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Background/Aims: Reports have suggested that the traditional Chinese medicine Smilacis Glabrae Rhizoma attenuates hyperuricemia, but its mechanism is unclear. Our previous study demonstrated that uric acid could induce the generation of reactive oxygen species(ROS), which subsequently cause endothelial dysfunction. Therefore, we focused on the oxidative stress process. In this study, we would use LC-MS and bioinformatic analysis to investigate the underlying mechanism. Methods: We utilized LC-MS to reveal the differential protein expression in the kidneys of rats in the hyperuricemia group and the Smilacis Glabrae Rhizoma treatment group and then subjected the differentially expressed proteins to bioinformatic analysis. We also determined the serum ROS level of the two groups. According the above results, we built our hypothesis and performed in vitro experiments to validate this hypothesis. Results: We found that catalase was upregulated in the group treated with Smilacis Glabrae Rhizoma, and the level of reactive oxygen species was higher in the hyperuricemia group. Thus, we speculated that Smilacis Glabrae Rhizoma could alleviate oxidative stress by upregulating catalase. In vitro experiments, we found that high concentrations of uric acid reduced catalase expression in endothelial cells, which was alleviated by Smilacis Glabrae Rhizoma and resulted in a reduction of reactive oxygen species. Knockdown of catalase led to an increase in reactive oxygen species. Conclusion: We demonstrated that Smilacis Glabrae Rhizoma could alleviate the oxidative stress caused by hyperuricemia by upregulating catalase expression. This finding could represent a new application for Smilacis Glabrae Rhizoma in the treatment of hyperuricemia. © 2014 S. Karger AG, Basel.
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Hierarchical Supramolecular Assembly of Sterically Demanding ?-Systems by Conjugation with Oligoprolines.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 08-15-2014
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Self-assembly from flexible worm-like threads via bundles of rigid fibers to nanosheets and nanotubes was achieved by covalent conjugation of perylene monoimide (PMI) chromophores with oligoprolines of increasing length. Whereas the chromophoric ?-system and the peptidic building block do not self-aggregate, the covalent conjugates furnish well-ordered supramolecular structures with a common wall/fiber thickness. Their morphology is controlled by the number of repeat units and can be tuned by seemingly subtle structural modifications.
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Postoperative Changes in Amniotic Membrane as a Carrier for Allogeneic Cultured Limbal Epithelial Transplantation.
Am. J. Ophthalmol.
PUBLISHED: 08-15-2014
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To investigate the morphologic changes and outcomes of the amniotic membrane as a carrier for allogeneic cultivated limbal epithelial transplantation.
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C-Type Lectin-like Receptor LOX-1 Promotes Dendritic Cell-Mediated Class-Switched B Cell Responses.
Immunity
PUBLISHED: 08-13-2014
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Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is a pattern-recognition receptor for a variety of endogenous and exogenous ligands. However, LOX-1 function in the host immune response is not fully understood. Here, we report that LOX-1 expressed on dendritic cells (DCs) and B cells promotes humoral responses. On B cells LOX-1 signaling upregulated CCR7, promoting cellular migration toward lymphoid tissues. LOX-1 signaling on DCs licensed the cells to promote B cell differentiation into class-switched plasmablasts and led to downregulation of chemokine receptor CXCR5 and upregulation of chemokine receptor CCR10 on plasmablasts, enabling their exit from germinal centers and migration toward local mucosa and skin. Finally, we found that targeting influenza hemagglutinin 1 (HA1) subunit to LOX-1 elicited HA1-specific protective antibody responses in rhesus macaques. Thus, LOX-1 expressed on B cells and DC cells has complementary functions to promote humoral immune responses.
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[Shock shape representation of sinus heart rate based on cloud model].
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi
PUBLISHED: 07-22-2014
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The present paper is to analyze the trend of sinus heart rate RR interphase sequence after a single ventricular premature beat and to compare it with the two parameters, turbulence onset (TO) and turbulence slope (TS). Based on the acquisition of sinus rhythm concussion sample, we in this paper use a piecewise linearization method to extract its linear characteristics, following which we describe shock form with natural language through cloud model. In the process of acquisition, we use the exponential smoothing method to forecast the position where QRS wave may appear to assist QRS wave detection, and use template to judge whether current cardiac is sinus rhythm. And we choose some signals from MIT-BIH Arrhythmia Database to detect whether the algorithm is effective in Matlab. The results show that our method can correctly detect the changing trend of sinus heart rate. The proposed method can achieve real-time detection of sinus rhythm shocks, which is simple and easily implemented, so that it is effective as a supplementary method.
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Comparative study of corneal endothelial cell damage after femtosecond laser assisted deep stromal dissection.
Biomed Res Int
PUBLISHED: 07-10-2014
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To find a relatively safe designed stromal bed thickness to avoid endothelial damage for lamellar keratoplasty with an Allegretto Wavelight FS200 femtosecond laser.
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Simvastatin attenuates angiotensin II?induced inflammation and oxidative stress in human mesangial cells.
Mol Med Rep
PUBLISHED: 06-20-2014
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Chronic kidney disease (CKD) is an intractable disease in which inflammation and oxidative stress are important. In the present study, the effect of simvastatin on inflammation and oxidative stress induced by angiotensin II (Ang II) in human mesangial cells (HMCs) and its corresponding mechanism was examined. In the in vitro experiment, HMCs were pretreated either without additives (control group) or with simvastatin at different concentrations (0, 0.1, 1 or 10 µM) for 1 h and were then stimulated by Ang II (1 µM) for 24 h. Following stimulation, the cells were collected for analysis using quantitative polymerase chain reaction, western blotting and dihydroethidium staining. The supernatant of the cells was collected and analyzed using an enzyme?linked immunosorbent assay. The results demonstrated that simvastatin suppressed the increased mRNA expression of monocyte chemoattractant protein?1, tumor necrosis factor??, interleukin (IL)?1? and IL?6 and the content of reactive oxygen species induced by Ang II in a dose?dependent manner. In addition, simvastatin decreased the protein expression of cyclooxygenase?2 (COX?2), nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and protein kinase C (PKC) as well as the content of prostaglandin E2 and the phosphorylation level of nuclear factor??B (NF??B) p65 in a dose?dependent manner. Furthermore, simvastatin significantly increased the protein expression of peroxisome proliferator?activated receptor ? (PPAR?). Therefore, simvastatin suppressed inflammation and oxidative stress in Ang II?stimulated HMCs via COX?2, PPAR?, NF??B, NADPH oxidase and PKCs, thereby exerting a protective effect on CKD.
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nDNA-Prot: identification of DNA-binding proteins based on unbalanced classification.
BMC Bioinformatics
PUBLISHED: 06-01-2014
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DNA-binding proteins are vital for the study of cellular processes. In recent genome engineering studies, the identification of proteins with certain functions has become increasingly important and needs to be performed rapidly and efficiently. In previous years, several approaches have been developed to improve the identification of DNA-binding proteins. However, the currently available resources are insufficient to accurately identify these proteins. Because of this, the previous research has been limited by the relatively unbalanced accuracy rate and the low identification success of the current methods.
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Multifunctional nanostructures based on porous silica covered Fe3O4@CeO2-Pt composites: a thermally stable and magnetically-recyclable catalyst system.
Chem. Commun. (Camb.)
PUBLISHED: 05-29-2014
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A facile surface protected silica shell etching method for fabricating multifunctional Fe3O4@CeO2-Pt@mSiO2 composites is reported. These multifunctional materials possess large magnetization, open mesopores, and a stably confined but exposed catalytically active component. The unique structures showed high thermal stability, magnetic recyclability and catalytic activity in catalytic reactions.
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[Effect of integrin beta8 on neuronal apoptosis after hypoxia ischemia in astrocyte/neuron co-culture system].
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi
PUBLISHED: 05-22-2014
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To observe the effect of integrin beta8 on the neuronal apoptosis after hypoxia ischemia (HI) in astrocyte/neuron co-culture system.
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Induction and activation of human Th17 by targeting antigens to dendritic cells via dectin-1.
J. Immunol.
PUBLISHED: 05-16-2014
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Recent compelling evidence indicates that Th17 confer host immunity against a variety of microbes, including extracellular and intracellular pathogens. Therefore, understanding mechanisms for the induction and activation of Ag-specific Th17 is important for the rational design of vaccines against pathogens. To study this, we employed an in vitro system in which influenza hemagglutinin (HA) 1 was delivered to dendritic cells (DCs) via Dectin-1 using anti-human Dectin-1 (hDectin-1)-HA1 recombinant fusion proteins. We found that healthy individuals maintained broad ranges of HA1-specific memory Th17 that were efficiently activated by DCs targeted with anti-hDectin-1-HA1. Nonetheless, these DCs were not able to induce a significant level of HA1-specific Th17 responses even in the presence of the Th17-promoting cytokines IL-1? and IL-6. We further found that the induction of surface IL-1R1 expression by signals via TCRs and common ?-chain receptors was essential for naive CD4(+) T cell differentiation into HA1-specific Th17. This process was dependent on MyD88, but not IL-1R-associated kinase 1/4. Thus, interruptions in STAT3 or MyD88 signaling led to substantially diminished HA1-specific Th17 induction. Taken together, the de novo generation of pathogen-specific human Th17 requires complex, but complementary, actions of multiple signals. Data from this study will help us design a new and effective vaccine strategy that can promote Th17-mediated immunity against microbial pathogens.
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Lumbar intervertebral disc puncture under C-arm fluoroscopy: a new rat model of lumbar intervertebral disc degeneration.
Exp. Anim.
PUBLISHED: 04-29-2014
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To establish a minimally invasive rat model of lumbar intervertebral disc degeneration (IDD) to better understand the pathophysiology of the human condition. The annulus fibrosus of lumbar level 4-5 (L4-5) and L5-6 discs were punctured by 27-gauge needles using the posterior approach under C-arm fluoroscopic guidance. Magnetic resonance imaging (MRI), histological examination by hematoxylin and eosin (H&E) staining, and reverse transcription polymerase chain reaction (RT-PCR) were performed at baseline and 2, 4, and 8 weeks after disc puncture surgery to determine the degree of degeneration. All sixty discs (thirty rats) were punctured successfully. Only two of thirty rats subjected to the procedure exhibited immediate neurological symptoms. The MRI results indicated a gradual increase in Pfirrmann grade from 4 to 8 weeks post-surgery (P<0.05), and H&E staining demonstrated a parallel increase in histological grade (P<0.05). Expression levels of aggrecan, type II collagen (Col2), and Sox9 mRNAs, which encode disc components, decreased gradually post-surgery. In contrast, mRNA expression of type I collagen (Col1), an indicator of fibrosis, increased (P<0.05). The procedure of annular puncture using a 27-gauge needle under C-arm fluoroscopic guidance had a high success rate. Histological, MRI, and RT-PCR results revealed that the rat model of disc degeneration is a progressive pathological process that is similar to human IDD.
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Cryo-EM study of the chromatin fiber reveals a double helix twisted by tetranucleosomal units.
Science
PUBLISHED: 04-26-2014
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The hierarchical packaging of eukaryotic chromatin plays a central role in transcriptional regulation and other DNA-related biological processes. Here, we report the 11-angstrom-resolution cryogenic electron microscopy (cryo-EM) structures of 30-nanometer chromatin fibers reconstituted in the presence of linker histone H1 and with different nucleosome repeat lengths. The structures show a histone H1-dependent left-handed twist of the repeating tetranucleosomal structural units, within which the four nucleosomes zigzag back and forth with a straight linker DNA. The asymmetric binding and the location of histone H1 in chromatin play a role in the formation of the 30-nanometer fiber. Our results provide mechanistic insights into how nucleosomes compact into higher-order chromatin fibers.
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Molecular cloning and analysis of gonadal expression of Foxl2 in the rice-field eel Monopterus albus.
Sci Rep
PUBLISHED: 04-14-2014
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We isolated the complete Foxl2 (Foxl2a) cDNA from the Monopterus albus ovary. An alignment of known Foxl2 amino-acid sequences confirmed the conservation of the Foxl2 open reading frame, especially the forkhead domain and C-terminal region. The expression of Foxl2 was detected in the brain, eyes, and gonads. A high level of Foxl2 expression in the ovary before sex reversal, but its transcripts decreased sharply when the gonad developed into the ovotestis and testis. The correlation between the Foxl2 expression and the process of sex development revealed the important function of Foxl2 during the sex reversal of M. albus. Immunohistochemical analysis showed that Foxl2 was expressed abundantly in granulosa cells and in the interstitial cells of the ovotestis and testis. These results suggest that Foxl2 plays a pivotal role in the development and maintenance of ovarian function. Foxl2 may be also involved in the early development of testis and the development of ocular structures of M. albus.
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Suppression of degradation induced by negative gate bias and illumination stress in amorphous InGaZnO thin-film transistors by applying negative drain bias.
ACS Appl Mater Interfaces
PUBLISHED: 04-10-2014
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The effect of drain bias (V(DS)) on the negative gate bias and illumination stress (NBIS) stability of amorphous InGaZnO (a-IGZO) thin-film transistors was investigated using a double-sweeping gate voltage (V(GS)) mode. The variation in the transfer characteristics was explored using current-voltage and capacitance-voltage characteristics. In the initial stage (<1000 s) of NBIS with grounded V(DS) (V(GS) = -40 V and V(DS) = 0 V), the transfer characteristics shifted negatively with an insignificant change in the subthreshold swing (SS) because of hole trapping at an IGZO/gate insulator interface. On the other hand, on-current degradation was observed and was accelerated in the forward measurement as the NBIS duration increased. The results indicated that NBIS induced donor-like defects near the conduction band; however, the transfer curves in the reverse measurement shifted positively without on-current and SS degradations. It was found that the degradations were enhanced by applying a positive V(DS) bias (V(GS) = -40 V and V(DS) = 40 V); in contrast, they could be reduced by applying a small negative V(DS) of V(DS) > V(GS) (V(GS) = -40 V and V(DS) = -20 V). Furthermore, it was confirmed that the NBIS degradations could be suppressed by applying a large negative V(DS) bias of V(DS) < V(GS) (V(GS) = -40 V and V(DS) = -60 V) during NBIS.
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Effects of ginsenoside Re on rat jejunal contractility.
J Nat Med
PUBLISHED: 03-03-2014
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Ginsenoside Re (GRe) exerts diverse effects. Based on our observations, the present study was designed to investigate GRe-exerted bidirectional regulation (BR) on the contractility of isolated jejunal segment. Six pairs of different low and high contractile states of rat jejunal segment were established and used in the study. Stimulatory effects on the contractility of jejunal segment were exerted by GRe (10.0 ?M) in all 6 low contractile states, and inhibitory effects were exerted in all 6 high contractile states, indicating that GRe exerted BR on the contractility of jejunal segment. The effects of GRe on the phosphorylation of 20 kDa myosin light chain, protein contents of myosin light chain kinase (MLCK) and MLCK mRNA expression in jejunal segment in low and high contractile states were also bidirectional. GRe-exerted BR was abolished in the presence of neurotoxin tetrodotoxin or Ca2+ channel blocker verapamil or c-Kit receptor tyrosine kinase inhibitor imatinib. Atropine blocked the stimulatory effects of GRe on jejunal contractility in low-Ca2+-induced low contractile state; phentolamine, propranolol and l-NG-nitro-arginine blocked the inhibitory effects in high-Ca2+-induced high contractile state, respectively. In summary, GRe-exerted BR depends on jejunal contractile state and requires the presence of enteric nervous system, Ca2+, and interstitial cells of Cajal; the stimulatory effects of GRe on jejunal contractility are related to cholinergic stimulation and inhibitory effects are related to adrenergic activation and nitric oxide relaxing mechanisms.
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miR-34a regulates mesangial cell proliferation via the PDGFR-?/Ras-MAPK signaling pathway.
Cell. Mol. Life Sci.
PUBLISHED: 02-28-2014
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The main pathological characteristic of glomerulonephritis is diffuse mesangial cell proliferation. MiR-34a is associated with the proliferation of various organs and cancer cells. However, the role of miR-34a in renal proliferation diseases is not clear. Therefore, this study aimed to elucidate the mechanism of miR-34a in the regulation of renal mesangial cell proliferation. The miR-34a expression level at different time points in an anti-Thy1 mesangial proliferative nephritis rat model was determined by qRT-PCR. The cell proliferation rate and cell cycle changes were measured in the in vitro cultured rat mesangial cells (RMCs). Our results suggested that miR-34a expression was negatively correlated with the degree of cell proliferation in the anti-Thy1 nephritis model. MiR-34a could extend the G0/G1 phase and block cell proliferation in RMCs. Dual-luciferase assay results showed that there were binding sites of miR-34a at 3'-UTR of platelet-derived growth factor receptor-? (PDGFR-?). MiR-34a can inhibit PDGFR-? protein expression at a post-transcriptional level, suppress Ras/MAPK signaling pathways, and down-regulate expression of cell cycle proteins at the G0/G1 phase, such as cyclin D1, CDK4/CDK6. In addition, miR-34a may also inhibit RMC proliferation by directly targeting cyclin E and CDK2. MiR-34a inhibits exogenous stimuli-induced proliferation of mesangial cells. Expression levels of phospho-PDGFR-? and phospho-MEK1 (an important downstream molecule in PDGFR-?-induced signaling pathway) were significantly increased in the anti-Thy-1 nephritis rat model. These results suggest that miR-34a may regulate RMC proliferation by directly inhibiting expressions of PDGFR-?, MEK1, and cell cycle proteins, cyclin E and CDK2.
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A virus-like particle based bivalent vaccine confers dual protection against enterovirus 71 and coxsackievirus A16 infections in mice.
Vaccine
PUBLISHED: 02-26-2014
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Enterovirus 71(EV71) and coxsackievirus A16 (CA16) are responsible for hand, foot and mouth disease which has been prevalent in Asia-Pacific regions, causing significant morbidity and mortality in young children. Co-circulation of and co-infection by both viruses underscores the importance and urgency of developing vaccines against both viruses simultaneously. Here we report the immunogenicity and protective efficacy of a bivalent combination vaccine comprised of EV71 and CA16 virus-like particles (VLPs). We show that monovalent EV71- or CA16-VLPs-elicited serum antibodies exhibited potent neutralization effect on the homotypic virus but little or no effect on the heterotypic one, whereas the antisera against the bivalent vaccine formulation were able to efficiently neutralize both EV71 and CA16, indicating there is no immunological interference between the two antigens with respect to their ability to induce virus-specific neutralizing antibodies. Passive immunization with monovalent VLP vaccines protected mice against a homotypic virus challenge but not heterotypic infection. Surprisingly, antibody-dependent enhancement (ADE) of disease was observed in mice passively transferred with mono-specific anti-CA16 VLP sera and subsequently challenged with EV71. In contrast, the bivalent VLP vaccine conferred full protection against lethal challenge by either EV71 or CA16, thus eliminating the potential of ADE. Taken together, our results demonstrate for the first time that the bivalent VLP approach represents a safe and efficacious vaccine strategy for both EV71 and CA16.
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Co(3)O(4)@CeO(2) core@shell cubes: designed synthesis and optimization of catalytic properties.
Chemistry
PUBLISHED: 02-26-2014
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Mastery of nanomaterial structure enables the control of its properties to enhance its performance for a given application. Herein, we demonstrate a fast and facile self-assembly method for the synthesis of a series of Co3 O4 @CeO2 core@shell cubes, which are characterized by SEM, TEM, XRD, inductively coupled plasma mass spectrometry (ICP-MS), and X-ray photoelectron spectroscopy (XPS) analyses. The results indicate that the thickness of the CeO2 shell can be tuned through simple variation of the feeding molar ratio of Ce/Co. These Co3 O4 @CeO2 core@shell cubes are used for catalytic CO oxidation and show good catalytic properties. Moreover, the relationship between the catalytic performance and the CeO2 shell thickness is studied in depth to optimize the catalytic properties.
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One family cluster of avian influenza A(H7N9) virus infection in Shandong, China.
BMC Infect. Dis.
PUBLISHED: 02-12-2014
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The first case of human infection with avian influenza A (H7N9) virus was identified in March, 2013 and the new H7N9 virus infected 134 patients and killed 45 people in China as of September 30, 2013. Family clusters with confirmed or suspected the new H7N9 virus infection were previously reported, but the family cluster of H7N9 virus infection in Shandong Province was first reported.
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Characterization of extended-spectrum beta-lactamases-producing Salmonella strains isolated from retail foods in Shaanxi and Henan Province, China.
Food Microbiol.
PUBLISHED: 02-03-2014
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Extended-spectrum beta-lactamases (ESBL)-producing Salmonella enterica have been reported worldwide. However, research on foodborne ESBL-producing Salmonella has been rarely conducted. One hundred and thirty eight ceftriaxone or/and cefoperazone-resistant Salmonella strains recovered from retail foods in Shaanxi and Henan Province, China, were screened for ESBL. The ESBL-producing strains were further characterized for antimicrobial resistance, pulse field gel electrophoresis (PFGE) profiles, and the presence of blaTEM, blaSHV, blaOXA, blaCTX-M, and blaPSE. The transferability of ESBL encoding genes to a susceptible Escherichia coli strain was also investigated. Thirty (21.7%) isolates were identified as ESBL positive and belonged to S. enterica serovars Indiana, Shubra, Typhimurium, and Enteritidis. S. Indiana and S. Shubra isolates were firstly identified in ESBL-producing strains. Great genetic diversity was seen among these ESBL-producing strains. Nucleotide sequence analysis revealed that blaTEM-1B was the only ESBL-encoding gene among the genes tested and was detected in 26 of 30 strains and was carried in the conjugative plasmids. The blaTEM-1B gene was transferable through conjugation at rates ranging from 4.71 × 10(-7) to 7.55 × 10(-6) transconjugant per recipient cell. This study provides the evidence of foodborne ESBL-producing Salmonella, and the transferability of plasmid harboring ESBL-encoding genes could possibly contribute to the dissemination of ESBL.
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Reference gene selection for real-time RT-PCR normalization in rice field eel (Monopterus albus) during gonad development.
Fish Physiol. Biochem.
PUBLISHED: 01-26-2014
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Real-time reverse transcriptase (RT) polymerase chain reaction (PCR) requires data normalization using an appropriate reference gene in order to obtain more reliable results with biological significance. We cloned a partial sequence of elongation factor-1-? (EF1?) and ribosomal protein L17 (RPL17) from Monopterus albus. We investigated the suitability of five commonly used reference genes [18S ribosomal RNA (18S), cytoskeletal protein (?-actin), glyceraldehyde phosphate dehydrogenase (GAPDH), EF1? and RPL17] as potential quantitative reference genes for normalizing real-time RT-PCR data generated in gonads of different developmental stages and in other tissues of M. albus. Analysis of the data indicated that 18S, ?-actin and GAPDH are not suitable as reference genes because of their levels of variations of expression. EF1? and RPL17 might be suitable as reference genes in the gonads of different developmental stages as well as in other tissues of M. albus.
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New in situ capture quantitative (real-time) reverse transcription-PCR method as an alternative approach for determining inactivation of Tulane virus.
Appl. Environ. Microbiol.
PUBLISHED: 01-24-2014
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Human noroviruses (HuNoVs) are the major cause of epidemic nonbacterial gastroenteritis. Although quantitative (real-time) reverse transcription-PCR (qRT-PCR) is widely used for detecting HuNoVs, it only detects the presence of viral RNA and does not indicate viral infectivity. Human blood group antigens (HBGAs) have been identified as receptors/co-receptors for both HuNoVs and Tulane virus (TV) and are crucial for viral infection. We propose that viral infectivity can be evaluated with a molecular assay based on receptor-captured viruses. In this study, we employed TV as an HuNoV surrogate to validate the HBGA-based capture qRT-PCR method against the 50% tissue culture infectious dose (TCID50) method. We employed type B HBGA on an immuno-well module to concentrate TV, followed by amplification of the captured viral genome by in situ qRT-PCR. We first demonstrated that this in situ capture qRT-PCR (ISC-qRT-PCR) method could effectively concentrate and detect TV. We then treated TV under either partial or full inactivation conditions and measured the remaining infectivity by ISC-qRT-PCR and a tissue culture-based amplification method (TCID50). We found that the ISC-qRT-PCR method could be used to evaluate virus inactivation deriving from damage to the capsid and study interactions between the capsid and viral receptor. Heat, chlorine, and ethanol treatment primarily affect the capsid structure, which in turns affects the ability of the capsid to bind to viral receptors. Inactivation of the virus by these methods could be reflected by the ISC-qRT-PCR method and confirmed by TCID50 assay. However, the loss of the infectivity caused by damage to the viral genome (such as that from UV irradiation) could not be effectively reflected by this method. Despite this limitation, the ISC-qRT-PCR provides an alternative approach to determine inactivation of Tulane virus. A particular advantage of the ISC-qRT-PCR method is that it is also a faster and easier method to effectively recover and detect the viruses, as there is no need to extract viral RNA or to transfer the captured virus from magnetic beads to PCR tubes for further amplification. Therefore, ISC-qRT-PCR can be easily adapted for use in automated systems for multiple samples.
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Surgical morbidity and oncologic results after concurrent chemoradiation therapy for advanced cervical cancer.
Int J Gynaecol Obstet
PUBLISHED: 01-20-2014
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To evaluate the surgical morbidity and oncologic results after concurrent chemoradiotherapy (CCRT) followed by completion surgery for advanced cervical carcinoma.
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Elimination of inter-domain interactions increases the cleavage fidelity of the restriction endonuclease DraIII.
Protein Cell
PUBLISHED: 01-05-2014
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DraIII is a type IIP restriction endonucleases (REases) that recognizes and creates a double strand break within the gapped palindromic sequence CAC?NNN?GTG of double-stranded DNA (? indicates nicking on the bottom strand; ? indicates nicking on the top strand). However, wild type DraIII shows significant star activity. In this study, it was found that the prominent star site is CAT?GTT?GTG, consisting of a star 5' half (CAT) and a canonical 3' half (GTG). DraIII nicks the 3' canonical half site at a faster rate than the 5' star half site, in contrast to the similar rate with the canonical full site. The crystal structure of the DraIII protein was solved. It indicated, as supported by mutagenesis, that DraIII possesses a ???-metal HNH active site. The structure revealed extensive intra-molecular interactions between the N-terminal domain and the C-terminal domain containing the HNH active site. Disruptions of these interactions through site-directed mutagenesis drastically increased cleavage fidelity. The understanding of fidelity mechanisms will enable generation of high fidelity REases.
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miR-199a-3p inhibits aurora kinase A and attenuates prostate cancer growth: new avenue for prostate cancer treatment.
Am. J. Pathol.
PUBLISHED: 01-02-2014
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Prostate cancer (PCa) is the most common solid tumor malignancy in men that severely influences quality of life. Surgery is most often the recommended treatment for PCa, but radical prostatectomy can cause significant urinary adverse effects. Therefore, finding effective biochemical treatments for PCa remains a necessity. Aurora kinase A has been shown to be involved in PCa progression, thus making it a good target for PCa therapy. miRNAs are important regulators of gene expression, with some miRNAs specifically involved in carcinogenesis. Therefore, herein, we identified miRNAs targeted to aurora kinase A and examined their effects on the growth of PCa. We used primary samples from PCa patients and PCa cell lines as research subjects. We demonstrate that miR-199a-3p is down-regulated in PCa tissues compared with normal prostate tissues, with the expression pattern inversely correlated with the expression pattern of aurora kinase A. We find that miR-199a-3p agomir inhibits aurora kinase A and attenuates xenograft tumor growth of PCa. Moreover, we demonstrate that down-regulation of miR-199a-3p results from enhancement of the methylation of miR-199a gene in PCa. Furthermore, we find that the expression level of miR-199a-3p is inversely correlated to tumor stage and Gleason score of PCa. Revealing novel mechanisms for oncogene inhibition by miRNA-mediated pathways offers new avenues for PCa treatment.
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In vitro synergistic antioxidant activity and identification of antioxidant components from Astragalus membranaceus and Paeonia lactiflora.
PLoS ONE
PUBLISHED: 01-01-2014
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Many traditionally used herbs demonstrate significantly better pharmacological effects when used in combination than when used alone. However, the mechanism underlying this synergism is still poorly understood. This study aimed to investigate the synergistic antioxidant activity of Astragalus membranaceus (AME) and Paeonia Lactiflora (PL), and identify the potential antioxidant components by 1,1-diphenyl-2-picrylhydrazine (DPPH) radical spiking test followed by a high performance liquid chromatography separation combined with diode array detection and tandem mass spectrometry analysis (DPPH-HPLC-DAD-MS/MS). Eight AME-PL combined extracts (E1-E8) were prepared based on bioactivity-guided fractionation. Among them, E1 exhibited the strongest synergistic effect in scavenging DPPH radicals and reducing ferric ions (P<0.05). Moreover, E1 presented strong cytoprotection against H2O2-induced oxidative damage in MRC-5 cells by suppressing the decrease of the superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) activities. A strong correlation between the increment of total phenolic/flavonoid and synergistic antioxidant activity, especially between the increment of total flavonoid and the increase in ferric reducing power was observed. Finally, seven antioxidant substances were identified in E1 as oxypaeoniflora, catechin, calycosin-7-O-?-D-glucopyranoside, fomononetin-7-O-?-D-glucopyranoside, 9,10-dimethoxy-pterocarpan-3-O-?-D-glucopyranoside, quercetin and 2'-dihydroxy-3',4'-dimethyl-isoflavan-7-O-?-D-glucopyranoside.
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Association between hypoxia and perinatal arterial ischemic stroke: a meta-analysis.
PLoS ONE
PUBLISHED: 01-01-2014
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Perinatal arterial ischemic stroke (AIS) occurs in an estimated 17 to 93 per 100000 live births, yet the etiology is poorly understood. Although investigators have implicated hypoxia as a potential cause of AIS, the role of hypoxia in AIS remains controversial. The aim of this study was to estimate the association between perinatal hypoxia factors and perinatal arterial ischemic stroke through a meta-analysis of published observational studies.
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Prevalence of Extended-Spectrum b-Lactamase-Producing Salmonella on Retail Chicken in Six Provinces and Two National Cities in the Peoples Republic of China.
J. Food Prot.
PUBLISHED: 12-03-2013
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Prevalence of extended-spectrum ?-lactamase (ESBL)-producing Salmonella in food is not well documented. This study investigated the prevalence of ESBL-producing Salmonella in 699 Salmonella isolates recovered from 1,152 retail chickens collected from six provinces and two national cities in the Peoples Republic of China in 2011. ESBL-producing isolates were screened by double-disk synergy test and confirmed using PCR and DNA sequencing. Of the 699 isolates tested, 60 (8.58%) were identified to be ESBL-producing Salmonella. Prevalence of ESBL-producing Salmonella was the highest in Shanghai city (17 [24.64%] of 69), followed by Shaanxi (10 [15.38%] of 65), Fujian (9 [11.69%] of 77), Guangdong (9 [7.69%] of 117), Sichuan (5 [7.25%] of 69), Beijing (6 [5.17%] of 116), Henan (4 [4.65%] of 86), and Guangxi (0 [0%] of 100) province. Significant difference (P < 0.05) in the prevalence of ESBL-producing Salmonella was found among six provinces and two cities. No significant difference (P > 0.05) in the prevalence was found between wet markets and supermarkets or between whole chickens and chopped chickens. The prevalence of ESBL-producing Salmonella differed significantly (P < 0.05) among different seasons, being higher in autumn than in spring and winter. Overall, ESBL-producing Salmonella varied significantly (P < 0.05) among 12 detected Salmonella serotypes: Abony (1 [33.33%] of 3), Indiana (28 [28.57%] of 98), Edinburg (6 [24.00%] of 25), Shubra (2 [20.00%] of 10), Uppsala (1 [16.67%] of 6), Thompson (8 [14.81%] of 54), Haardt (1 [12.50%] of 8), Agona (3 [9.68%] of 31), Gueuletapee (1 [6.25%] of 16), Typhimurium (4 [5.56%] of 72), Heidelberg (1 [4.55%] of 22), and Enteritidis (4 [3.17%] of 126). This study revealed that ESBL-producing Salmonella do exist in retail chicken in the Peoples Republic of China and that the potential risk of their presence in foods needs further exploration.
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Chemical composition and synergistic antioxidant activities of essential oils from Atractylodes macrocephala and Astragalus membranaceus.
Nat Prod Commun
PUBLISHED: 11-27-2013
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Chemical composition of the essential oils derived from Atractylodes macrocephala (AMA), Astragalus membranaceus (AME) and AMA-AME herb pair was investigated using gas chromatography-mass spectrometry (GC-MS). Antioxidant activities were evaluated by 1,1-diphenyl-2-picyrlhydrazyl (DPPH) radical-scavenging and Trolox equivalent antioxidant capacity (TEAC) assays. Forty-five, ten and forty-three components were identified in AMA, AME and AMA-AME essential oils, respectively. AMA-AME essential oil exhibited a significantly higher radical scavenging capacity than the theoretical sum of those of the respective herb essential oils (P < 0.05). Principal component analysis showed that twenty-three components contributed to the scavenging activities against DPPH and ABTS*+ radicals. Moreover, the concentrations of these major components exhibited various increases to some extent when compared with the theoretical sum of the respective herb essential oils. These findings suggest that combination of two or more herbs might be used as a promising source of natural antioxidants in the pharmaceutical and food industries.
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Seasonal dynamics and diversity of bacteria in retail oyster tissues.
Int. J. Food Microbiol.
PUBLISHED: 10-14-2013
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Oysters are one of the important vehicles for the transfer of foodborne pathogens. It was reported that bacteria could be bio-accumulated mainly in the gills and digestive glands. In artificially treated oysters, bacterial communities have been investigated by culture-independent methods after harvest. However, little information is available on the seasonal dynamics of bacterial accumulation in retail oyster tissues. In this study, retail oysters were collected from local market in different seasons. The seasonal dynamics and diversity of bacteria in oyster tissues, including the gills, digestive glands and residual tissues, were analyzed by denaturing gradient gel electrophoresis (DGGE). It was interesting that the highest bacterial diversity appeared in the Fall season, not in summer. Our results indicated that Proteobacteria was the predominant member (23/46) in oyster tissues. Our results also suggested that bacterial diversity in gills was higher than that in digestive glands and other tissues. In addition, not all the bacteria collected from surrounding water by gills were transferred to digestive glands. On the other hand, few bacteria were found in oyster tissues except in the gills. Therefore, the gills could be the best candidate target tissue for monitoring of pathogenic bacteria either to human or to oyster.
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Pt@CeO2 multicore@shell self-assembled nanospheres: clean synthesis, structure optimization, and catalytic applications.
J. Am. Chem. Soc.
PUBLISHED: 10-14-2013
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A clean nonorganic synthetic method has been developed to fabricate the uniform pomegranate-like Pt@CeO2 multicore@shell nanospheres in a large scale. Under the effective protection of Ar atmosphere the redox reaction just simply happened between Ce(NO3)3 and K2PtCl4 in an alkaline aqueous solution, in which no other reducing agents or surfactants were added. The as-obtained nanospheres exhibited excellent structure stability even being calcined at 600 °C for 5 h. Moreover, the as-obtained Pt@CeO2 multicore@shell nanospheres can be further supported on reduced graphene oxide (RGO) to form heterogeneous nanocatalyst, which has been successfully applied in the chemical reduction reaction of nitrophenol (NP) by ammonia borane (NH3BH3, dubbed as AB) instead of hazardous H2 or NaBH4.
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Effects of ginsenosides on rat jejunal contractility.
Pharm Biol
PUBLISHED: 09-30-2013
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Abstract Context: Ginsenosides are primary active ingredients of ginseng, which are believed to have various health benefits. It is found that the biotransformation of ginsenosides mainly takes place in the gastrointestinal tract and the information about ginsenosides-exerted effects on intestinal contractility is not sufficient. Aims: The present study proposed that ginsenosides could exert stimulatory or inhibitory effects on intestinal motility depending on the assay condition-related intestinal contractile states and was to characterize the effects of ginsenosides on intestinal motility. Methods: Jejunal contractility determination, Western blotting analysis, and real-time polymerase chain reaction were performed to test the effects of total ginsenosides isolated from Panax ginseng C. A. Mey (Araliaceae) root. Results: The results showed that ginsenosides at the fixed concentration of 20?mg/L exerted bidirectional regulation (BR) on the contractility of isolated jejunal segment (IJS), depending on the contractile states. The contractility of IJS was increased by ginsenosides in low contractile states, which were correlated to the cholinergic activation, and the contractility of IJS was decreased by ginsenosides in high contractile states, which were correlated to the adrenergic activation and nitric oxide related mechanisms. Ginsenosides-induced BR was abolished in the absence of Ca(2+) or by using tetrodotoxin, implicating the requirement of Ca(2+) and the enteric nervous system. Effects of ginsenosides on myosin light chain phosphorylation and the mRNA expression of myosin light chain kinase were also bidirectional. Discussion and conclusion: Results suggest that ginsenosides may have the potential clinical implication for reliving the symptoms of alternative hypo- and hyper-intestinal motility.
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Multivariate statistical characterization of charged and uncharged domain walls in multiferroic hexagonal YMnO3 single crystal visualized by a spherical aberration-corrected STEM.
Nano Lett.
PUBLISHED: 09-19-2013
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A state-of-the-art spherical aberration-corrected STEM was fully utilized to directly visualize the multiferroic domain structure in a hexagonal YMnO3 single crystal at atomic scale. With the aid of multivariate statistical analysis (MSA), we obtained unbiased and quantitative maps of ferroelectric domain structures with atomic resolution. Such a statistical image analysis of the transition region between opposite polarizations has confirmed atomically sharp transitions of ferroelectric polarization both in antiparallel (uncharged) and tail-to-tail 180° (charged) domain boundaries. Through the analysis, a correlated subatomic image shift of Mn-O layers with that of Y layers, exhibiting a double-arc shape of reversed curvatures, have been elucidated. The amount of image shift in Mn-O layers along the c-axis is statistically significant as small as 0.016 nm, roughly one-third of the evident image shift of 0.048 nm in Y layers. Interestingly, a careful analysis has shown that such a subatomic image shift in Mn-O layers vanishes at the tail-to-tail 180° domain boundaries. Furthermore, taking advantage of the annular bright field (ABF) imaging technique combined with MSA, the tilting of MnO5 bipyramids, the very core mechanism of multiferroicity of the material, is evaluated.
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Manipulation of domain wall mobility by oxygen vacancy ordering in multiferroic YMnO3.
Phys Chem Chem Phys
PUBLISHED: 09-18-2013
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The mobility of the ferroelectric domain phases and the local conductivity of ferroelectric domain walls in multiferroic YMnO3 crystals grown in air and reduced atmosphere were studied by piezoresponse force microscopy (PFM), tip-enhanced Raman spectroscopy (TERS) and conductive atomic force microscopy (CAFM). Oxygen vacancies were found to reduce the strength of 4d-2p (Y(3+)-O(2-)) hybridization and structural trimerization distortion, leading to the disappearance of the six wedge-shaped ferroelectric domain phases in oxygen deficient YMnO3-? crystals. We observed anisotropic domain wall motion such that the wedge-shaped domain configuration joined at one point could be changed to the stripe domain configuration by applying high electric fields in oxygen deficient YMnO3-? single crystals. The local conductivity of the domain walls increased significantly in poled YMnO3-? single crystals. The straight conductive domain walls in YMnO3-?, instead of the twisted insulating ones in the stoichiometric crystal, are induced by the ordered oxygen vacancies which are verified by TERS measurements.
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Inactivation conditions for human norovirus measured by an in situ capture-qRT-PCR method.
Int. J. Food Microbiol.
PUBLISHED: 09-17-2013
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Human norovirus (HuNoV) is a leading cause of foodborne gastroenteritis. Unfortunately, the inactivation parameters for HuNoV in clinical, food and environmental samples have not been established. Due to the inability to cultivate HuNoV in vitro, quantitative real-time RT-PCR (qRT-PCR) is widely-used for detecting HuNoVs. However, qRT-PCR does not indicate viral infectivity. Our method employs histo-blood group antigens (HBGAs) as viral receptors/co-receptors and container-affixed capture agents to concentrate HuNoVs. The captured viruses are denatured and its genome is amplified in the same module by in situ capture qRT-PCR (ISC-qRT-PCR). Greater than three log10 reduction in the receptor-captured viral genomic signal (RCVGS) was observed when HuNoV was treated by heat at 72°C for 4min, by chlorine at a final concentration of 16ppm in less than 1min, and by UV irradiation at 1J/cm(2). Treatment of low-titer HuNoV (<10(3) copies/sample) with 70% ethanol for 20s reduced the RCVGS of HuNoV by two log10. However, ethanol had a limited effect on high-titer samples of HuNoV (>10(3) copies/sample). The results demonstrate that ISC-qRT-PCR method could be used as an alternative method to measure encapsidated viral RNA and indirectly indicate the inactivation status of HuNoV caused by physical treatment such as heat, and chemical treatment such as chlorine, that damage the ability of the virus to bind to its receptor.
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MiR-139-5p inhibits HGTD-P and regulates neuronal apoptosis induced by hypoxia-ischemia in neonatal rats.
Neurobiol. Dis.
PUBLISHED: 08-03-2013
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Human growth transformation dependent protein (HGTD-P) is a newly identified protein that promotes neuronal apoptosis in hypoxia-ischemia brain damage (HIBD) in neonatal rats. However, the mechanisms regulating HGTD-P expression are not clear. Here we describe microRNAs targeted to HGTD-P and examine their effects on regulating neuronal apoptosis in HIBD. We use samples from cultured neurons after oxygen-glucose deprivation (OGD) and postnatal day 10 rat brains after hypoxia-ischemia (HI). RT-PCR, Western blotting, and immunostaining are used to detect the expression of HGTD-P and cleaved caspase 3, as well as real-time PCR detects microRNA expression. MicroRNA agomir is used to inhibit the expression of HGTD-P, and DAPI, TUNEL, and TTC staining are employed to detect cell apoptosis and brain damage. Moreover, in vitro processing assay is used to examine the mechanism by which HI down-regulates miR-139-5p expression. We found that miR-139-5p is down-regulated in neurons and rat brains after HI treatment. The expression pattern of miR-139-5p correlates inversely with that of HGTD-P. Furthermore, miR-139-5p agomir inhibits neuronal apoptosis and attenuates HIBD, which is concurrent with down-regulation of HGTD-P. Moreover, pre-miR-139 processing activity decreases in extracts from OGD neurons, and OGD neuronal extracts attenuates the processing of pre-miR-139 by Dicer. In conclusion, HI induces inhibitors which block the processing step of pre-miR-139, resulting in the down-regulation of mature miR-139-5p. The down-regulation of miR-139-5p plays a critical role in the up-regulation of HGTD-P expression. MiR-139-5p agomir attenuates brain damage when used 12h after HI, providing a longer therapeutic window than anti-apoptosis compounds currently available.
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Pharmacologic inhibition of PKC? and PKC? prevents GVHD while preserving GVL activity in mice.
Blood
PUBLISHED: 08-01-2013
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Allogeneic hematopoietic cell transplantation (HCT) is the most effective therapy for hematopoietic malignancies through T-cell-mediated graft-vs-leukemia (GVL) effects but often leads to severe graft-vs-host disease (GVHD). Given that protein kinase C? (PKC?), in cooperation with PKC?, is essential for T-cell signaling and function, we have evaluated PKC? and PKC? as potential therapeutic targets in allogeneic HCT using genetic and pharmacologic approaches. We found that the ability of PKC?(-/-)/?(-/-) donor T cells to induce GVHD was further reduced compared with PKC?(-/-) T cells in relation with the relevance of both isoforms to allogeneic donor T-cell proliferation, cytokine production, and migration to GVHD target organs. Treatment with a specific inhibitor for both PKC? and PKC? impaired donor T-cell proliferation, migration, and chemokine/cytokine production and significantly decreased GVHD in myeloablative preclinical murine models of allogeneic HCT. Moreover, pharmacologic inhibition of PKC? and PKC? spared T-cell cytotoxic function and GVL effects. Our findings indicate that PKC? and ? contribute to T-cell activation with overlapping functions essential for GVHD induction while less critical to the GVL effect. Thus, targeting PKC? and PKC? signaling with pharmacologic inhibitors presents a therapeutic option for GVHD prevention while largely preserving the GVL activity in patients receiving HCT.
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Depth-aware image seam carving.
IEEE Trans Cybern
PUBLISHED: 07-22-2013
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Image seam carving algorithm should preserve important and salient objects as much as possible when changing the image size, while not removing the secondary objects in the scene. However, it is still difficult to determine the important and salient objects that avoid the distortion of these objects after resizing the input image. In this paper, we develop a novel depth-aware single image seam carving approach by taking advantage of the modern depth cameras such as the Kinect sensor, which captures the RGB color image and its corresponding depth map simultaneously. By considering both the depth information and the just noticeable difference (JND) model, we develop an efficient JND-based significant computation approach using the multiscale graph cut based energy optimization. Our method achieves the better seam carving performance by cutting the near objects less seams while removing distant objects more seams. To the best of our knowledge, our algorithm is the first work to use the true depth map captured by Kinect depth camera for single image seam carving. The experimental results demonstrate that the proposed approach produces better seam carving results than previous content-aware seam carving methods.
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Effective biodemulsifier components secreted by Bacillus mojavensis XH-1 and analysis of the demulsification process.
Biodegradation
PUBLISHED: 07-04-2013
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The purpose of the present study was to investigate the effective components of the demulsifying bacterial strain Bacillus mojavensis XH-1 and its demulsification process. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and the shotgun LC-MS/MS method were used to separate and identify proteins with efficient demulsification activity. The zeta potential changes of the emulsion before and after addition of the biodemulsifier were tested, and the relationships between oil-in-water interfacial tension, the demulsification efficiency and the biodemulsifier structure were examined. The study results indicate that the effective biodemulsifier components were extracellular proteins attached to the cells or secreted into the culture solution that presented as a 50-80 kDa band observed by SDS-PAGE. Six of the proteins were unknown or unnamed, and the demulsifying functions of another 14 proteins had not been previously reported. The main demulsification mechanisms were determined to be solubilization and replacement. When the concentration of the biodemulsifier was low, the replacement mechanism dominated, and the demulsification ratio increased with the biodemulsifier concentration. Solubilization dominated when a high concentration of biodemulsifier was provided, and the demulsification ratio decreased as the biodemulsifier concentration increased.
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Effects of Conditioning with Sevoflurane before Reperfusion on Hippocampal Ischemic Injury and Insulin-like Growth Factor-1 Expression in Rats.
Chin J Physiol
PUBLISHED: 06-29-2013
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Sevoflurane pre-conditioning before ischemia can reduce ischemia-reperfusion injuries in cardiac, pulmonary and cerebral tissues. It is uncertain whether sevoflurane conditioning before reperfusion has similar protective effects on neuronal injuries. In this study, we explored the effect of sevoflurane conditioning (at concentrations of 1.5%, 2.4% or 3.0%) on the morphology and molecular mechanisms of the hippocampal CA? region in male Sprague-Dawley rats subjected to global cerebral ischemia. We determined the pathological results by hematoxylin and eosin (H&E) staining and examined the mRNA levels of insulin-like growth factor-1 (IGF-1) and protein levels of p-JNK1/2 and p-Akt1 in the hippocampus at 24 h, 48 h and 72 h after global cerebral ischemia-reperfusion. Our data showed that O? post-conditioning and lower dose (1.5%) of sevoflurane did not ameliorate ischemia-induced CA? injury. However, higher doses of 2.4% and 3.0% sevoflurane post-conditioning alleviated the CA? injury and enhanced the expression levels of IGF-1 mRNA. Furthermore, sevoflurane post-conditioning inhibited the activations of p-JNK1/2 and enhanced activation of p-Akt1. In conclusion, these results suggest that post-conditioning with sevoflurane at 2.4% and 3.0% ameliorates global cerebral ischemia induced hippocampal CA? injury by up-regulating the expression of IGF-1 mRNA followed by the activation of p-Akt1 and inhibition of the activation of p-JNK1/2.
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High quantum-yield CdSexS1-x/ZnS core/shell quantum dots for warm white light-emitting diodes with good color rendering.
Nanotechnology
PUBLISHED: 06-20-2013
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Composition-controllable ternary CdSe(x)S(1-x) quantum dots (QDs) with multiple emission colors were obtained via a hot-injection-like method at a relatively low injection temperature (230?° C) in octadecene. Then highly fluorescent CdSe(x)S(1-x)/ZnS core/shell (CS) QDs were synthesized by a facile single-molecular precursor approach. The fluorescent quantum yield of the resulting green (?(em) = 523 nm), yellow (?(em) = 565 nm) and red (?(em) = 621 nm) emission of CS QDs in toluene reached up to 85%, 55% and 39%, respectively. Moreover, a QDs white light-emitting diode (QDs-WLED) was fabricated by hybridizing green-, yellow- and red-emitting CdSe(x)S(1-x)/ZnS CS QDs/epoxy composites on a blue InGaN chip. The resulting four-band RYGB QDs-WLED showed good performance with CIE-1931 coordinates of (0.4137, 0.3955), an R(a) of 81, and a T(c) of 3360 K at 30 mA, which indicated the combination of multiple-color QDs with high fluorescence QYs in LEDs as a promising approach to obtain warm WLEDs with good color rendering.
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Switch of glycolysis to gluconeogenesis by dexamethasone for treatment of hepatocarcinoma.
Nat Commun
PUBLISHED: 06-16-2013
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Gluconeogenesis is a fundamental feature of hepatocytes. Whether this gluconeogenic activity is also present in malignant hepatocytes remains unexplored. A better understanding of this biological process may lead to novel therapeutic strategies. Here we show that gluconeogenesis is not present in mouse or human malignant hepatocytes. We find that two critical enzymes 11?-HSD1 and 11?-HSD2 that regulate glucocorticoid activities are expressed inversely in malignant hepatocytes, resulting in the inactivation of endogenous glucocorticoids and the loss of gluconeogenesis. In patients hepatocarcinoma, the expression of 11?-HSD1 and 11?-HSD2 is closely linked to prognosis and survival. Dexamethasone, an active form of synthesized glucocorticoids, is capable of restoring gluconeogenesis in malignant cells by bypassing the abnormal regulation of 11?-HSD enzymes, leading to therapeutic efficacy against hepatocarcinoma. These findings clarify the molecular basis of malignant hepatocyte loss of gluconeogenesis and suggest new therapeutic strategies.
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Inhibition of oncogenic Pim-3 kinase modulates transformed growth and chemosensitizes pancreatic cancer cells to gemcitabine.
Cancer Biol. Ther.
PUBLISHED: 06-14-2013
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Pancreatic ductal adenocarcinoma (PDAC) is a lethal cancer with a 5-year survival rate of only 6%. Although the cytosine analog gemcitabine is the drug commonly used to treat PDAC, chemoresistance unfortunately renders the drug ineffective. Thus, strategies that can decrease this resistance will be essential for improving the dismal outcome of patients suffering from this disease. We previously observed that oncogenic Pim-1 kinase was aberrantly expressed in PDAC tissues and cell lines and was responsible for radioresistance. Furthermore, members of the Pim family have been shown to reduce the efficacy of chemotherapeutic drugs in cancer. Therefore, we attempted to evaluate the role of Pim-3 in chemoresistance of PDAC cells. We were able to confirm upregulation of the Pim-3 oncogene in PDAC tissues and cell lines versus normal samples. Biological consequences of inhibiting Pim-3 expression with shRNA-mediated suppression included decreases in anchorage-dependent growth, invasion through Matrigel and chemoresistance to gemcitabine as measured by caspase-3 activity. Additionally, we were able to demonstrate that Pim-1 and Pim-3 play overlapping but non-identical roles as it relates to gemcitabine sensitivity of pancreatic cancer cells. To further support the role of Pim-3 suppression in sensitizing PDAC cells to gemcitabine, we used the pharmacological Pim kinase inhibitor SGI-1776. Treatment of PDAC cells with SGI-1776 resulted in decreased phosphorylation of the proapoptotic protein Bad and cell cycle changes. When SGI-1776 was combined with gemcitabine, there was a greater decrease in cell viability in the PDAC cells versus cells treated with either of the drugs separately. These results suggest combining drug therapies that inhibit Pim kinases, such as Pim-3, with chemotherapeutic agents, to aid in decreasing chemoresistance in pancreatic cancer.
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Fluorescence correlation spectroscopy of repulsive systems: theory, simulation, and experiment.
J Chem Phys
PUBLISHED: 06-14-2013
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The theoretical basis of fluorescence correlation spectroscopy (FCS) for repulsive systems, such as charged colloids or macromolecules, has been further expanded and developed. It is established that the collective correlation function can no longer be fitted using the theoretical model of non-interacting systems. Also, it is discovered that the collective correlation function can be divided into two parts: a self-part and a distinct-part, named as the self-correlation and cross-correlation function, respectively. The former indicates the self-diffusion of objects, while the latter describes mutual interactions. Dual-color fluorescence cross-correlation spectroscopy provides the direct measurements of the two parts. The particle concentration and mean squared displacement of single particles can be deduced from the self-correlation function, while the correlation volume between particles can be approximated from the cross-correlation function. In the case of charged colloids, the Debye length of the solution and particle surface charge number can be fitted from the cross-correlation function. These theoretical results are successfully proven using Brownian dynamics simulations and preliminary FCS experiments for model charged colloidal systems.
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SPSSM8: an accurate approach for predicting eight-state secondary structures of proteins.
Biochimie
PUBLISHED: 06-08-2013
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Protein eight-state secondary structure prediction is challenging, but is necessary to determine protein structure and function. Here, we report the development of a novel approach, SPSSM8, to predict eight-state secondary structures of proteins accurately from sequences based on the structural position-specific scoring matrix (SPSSM). The SPSSM has been successfully utilized to predict three-state secondary structures. Now we employ an eight-state SPSSM as a feature that is obtained from sequence structure alignment against a large database of 9 million sequences with putative structural information. The SPSSM8 uses a low sequence identity dataset (9062 entries) as a training set and conditional random field for the classification algorithm. The SPSSM8 achieved an average eight-state secondary structure accuracy (Q8) of 71.7% (Q3, 81.6%) for an independent testing set (463 entries), which had an improved accuracy of 10.1% and 4.6% compared with SSPro8 and CNF, respectively, and significantly improved the accuracy of eight-state secondary structure prediction. For CASP 9 dataset (92 entries) the SPSSM8 achieved a Q8 accuracy of 80.1% (Q3, 83.0%). The SPSSM8 was confirmed as an outstanding predictor for eight-state secondary structures of proteins. SPSSM8 is freely available at http://cal.tongji.edu.cn/SPSSM8.
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A rapid method for the detection of foodborne pathogens by extraction of a trace amount of DNA from raw milk based on amino-modified silica-coated magnetic nanoparticles and polymerase chain reaction.
Anal. Chim. Acta
PUBLISHED: 05-20-2013
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A method based on amino-modified silica-coated magnetic nanoparticles (ASMNPs) and polymerase chain reaction (PCR) was developed to rapidly and sensitively detect foodborne pathogens in raw milk. After optimizing parameters such as pH, temperature, and time, a trace amount of genomic DNA of pathogens could be extracted directly from complex matrices such as raw milk using ASMNPs. The magnetically separated complexes of genomic DNA and ASMNPs were directly subjected to single PCR (S-PCR) or multiplex PCR (M-PCR) to detect single or multiple pathogens from raw milk samples. Salmonella Enteritidis (Gram-negative) and Listeria monocytogenes (Gram-positive) were used as model organisms to artificially contaminate raw milk samples. After magnetic separation and S-PCR, the detection sensitivities were 8 CFU mL(-1) and 13 CFU mL(-1) respectively for these two types of pathogens. Furthermore, this method was successfully used to detect multiple pathogens (S. Enteritidis and L. monocytogenes) from artificially contaminated raw milk using M-PCR at sensitivities of 15 CFU mL(-1) and 25 CFU mL(-1), respectively. This method has great potential to rapidly and sensitively detect pathogens in raw milk or other complex food matrices.
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The impact of titanium dioxide nanoparticles on biological nitrogen removal from wastewater and bacterial community shifts in activated sludge.
Biodegradation
PUBLISHED: 05-03-2013
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The potential impact of titanium dioxide nanoparticles (TiO2 NPs) on nitrogen removal from wastewater in activated sludge was investigated using a sequencing batch reactor. The addition of 2-50 mg L(-1) of TiO2 NPs did not adversely affect nitrogen removal. However, when the activated sludge was exposed to 100-200 mg L(-1) of TiO2 NPs, the effluent total nitrogen removal efficiencies were 36.5 % and 20.3 %, respectively, which are markedly lower than the values observed in the control test (80 %). Further studies showed that the decrease in biological nitrogen removal induced by higher concentrations of TiO2 NPs was due to an inhibitory effect on the de-nitrification process. Denaturing gradient gel electrophoresis profiles showed that 200 mg L(-1) of TiO2 NPs significantly reduced microbial diversity in the activated sludge. The effect of light on the antibacterial activity of TiO2 NPs was also investigated, and the results showed that the levels of TiO2-dependent inhibition of biological nitrogen removal were similar under both dark and light conditions. Additional studies revealed that different TiO2 concentrations had a significant effect on dehydrogenase activity, and this effect was most likely the result of decreased microbial activity.
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c-Rel is an essential transcription factor for the development of acute graft-versus-host disease in mice.
Eur. J. Immunol.
PUBLISHED: 04-12-2013
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Transcription factors of the Rel/NF-?B family are known to play different roles in immunity and inflammation, although the putative role of c-Rel in transplant tolerance and graft-versus-host disease (GVHD) remains elusive. We report here that T cells deficient for c-Rel have a dramatically reduced ability to cause acute GVHD after allogeneic bone marrow transplantation using major and minor histocompatibility mismatched murine models. In the study to understand the underlying mechanisms, we found that c-Rel(-/-) T cells had a reduced ability to expand in lymphoid organs and to infiltrate in GVHD target organs in allogeneic recipients. c-Rel(-/-) T cells were defective in the differentiation into Th1 cells after encountering alloantigens, but were enhanced in the differentiation toward Foxp3(+) regulatory T (Treg) cells. Furthermore, c-Rel(-/-) T cells had largely preserved activity to mediate graft-versus-leukemia response. Taken together, our findings indicate that c-Rel plays an essential role in T cells in the induction of acute GVHD, and suggest that c-Rel can be a potential target for therapeutic intervention in allogeneic hematopoietic cell transplantation in the clinic.
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2-Ureido-4-pyrimidone-based hydrogels with multiple responses.
Chemphyschem
PUBLISHED: 04-11-2013
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Functionalisation of poly[2-(dimethylamino)ethyl methacrylate] (a responsive methacrylate) with light-activatable 2-ureido-4-pyrimidone units allows a supramolecular hydrogel to be obtained that combines temperature, light and pH response with self-healing properties. Whereas the self-healing properties of this system were described previously, this report focuses on its response to different external stimuli, which is studied by quartz crystal microbalance analysis of thin films of the material. Reversible collapse with increasing temperature, reversible swelling with decreasing pH and irreversible shrinkage with UV exposure are demonstrated. These three stimuli are combined to have externally gated or tuned responses. Thermo-induced swelling and shrinkage can be reversibly inhibited by changing the pH and irreversibly regulated by exposure to light of different doses. These materials represent the first general strategy to obtain responsive self-healing hydrogels in which the response and the self-healing properties are decoupled from each other and can be tuned independently.
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Graphene oxide covalently grafted upconversion nanoparticles for combined NIR mediated imaging and photothermal/photodynamic cancer therapy.
Biomaterials
PUBLISHED: 04-11-2013
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Theranostics, the integration of diagnostics and therapies, has become a new concept in the battles with various major diseases such as cancer. Here, we report a multifunctional nanoplatform, which is developed by covalently grafting core-shell structured upconversion nanoparticles (UCNPs) with nanographene oxide (NGO) via bifunctional polyethylene glycol (PEG), and then loading phthalocyanine (ZnPc) on the surface of NGO. The obtained UCNPs-NGO/ZnPc nanocomposites are not only be used as upconversion luminescence (UCL) imaging probes of cells and whole-body animals with high contrast for diagnosis, but also can generate cytotoxic singlet oxygen under light excitation for photodynamic therapy (PDT), as well as rapidly and efficiently convert the 808 nm laser energy into thermal energy for photothermal therapy (PTT). A remarkably improved and synergistic therapeutic effect compared to PTT or PDT alone is obtained, providing high therapeutic efficiency for cancer treatment. Therefore, benefiting from the unique multifunctional hybrid nanostructure, UCNPs-NGO/ZnPc nanocomposites developed herein are promising as an integrated theranostic probe for potential UCL image-guided combinatorial PDT/PTT of cancer.
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Structure-activity relationship (SAR) of withanolides to inhibit Hsp90 for its activity in pancreatic cancer cells.
Invest New Drugs
PUBLISHED: 03-20-2013
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Withaferin A (WA), a naturally occurring steroidal lactone, directly binds to Hsp90 and leads to the degradation of Hsp90 client protein. The purpose of this study is to investigate the structure activity relationship (SAR) of withanolides for their inhibition of Hsp90 and anti-proliferative activities in pancreatic cancer cells. In pancreatic cancer Panc-1 cells, withaferin A (WA) and its four analogues withanolide E (WE), 4-hydroxywithanolide E (HWE), 3-aziridinylwithaferin A (AzWA) inhibited cell proliferation with IC50 ranged from 1.0 to 2.8 ?M. WA, WE, HWE, and AzWA also induced caspase-3 activity by 21-, 6-, 11- and 15-fold, respectively, in Panc-1 cells, while withaperuvin (WP) did not show any activity. Our data showed that WA, WE, HWE, and AzWA, but not WP, all directly bound to Hsp90 and induced Hsp90 aggregation,hence inhibited Hsp90 chaperone activity to induce degradation of Hsp90 client proteins Akt and Cdk4 through proteasome-dependent pathway in pancreatic cancer cells. However, only WA, HWE and AzWA disrupted Hsp90-Cdc37 complexes but not WE and WP. SAR study suggested that the C-5(6)-epoxy functional group contributes considerably for withanolide to bind to Hsp90, inhibit Hsp90 chaperone activity, and result in Hsp90 client protein depletion. Meanwhile, the hydroxyl group at C-4 of ring A may enhance withanolide to inhibit Hsp90 activity and disrupt Hsp90-Cdc37 interaction. These SAR data provide possible mechanisms of anti-proliferative action of withanolides.
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Graphene oxide induced formation of Pt-CeO? hybrid nanoflowers with tunable CeO? thickness for catalytic hydrolysis of ammonia borane.
Chemistry
PUBLISHED: 01-31-2013
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Pt-CeO?: Flowerlike Pt-CeO? hybrids on reduced graphene oxide (RGO) can be prepared by treating Pt cubes with Ce(NO?)? in the presence of graphene oxide. The density of the CeO? coating around the Pt cubes depends on the amount of Ce(NO?)? used. The as-obtained samples exhibit high stability and activity for the catalytic hydrolysis of ammonia borane (AB).
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Phylogenetic investigations on ten genera of tintinnid ciliates (Ciliophora: Spirotrichea: Tintinnida), based on small subunit ribosomal RNA gene sequences.
J. Eukaryot. Microbiol.
PUBLISHED: 01-24-2013
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Tintinnida is a diverse taxon that accommodates over 1,500 morphospecies, which is an important component of marine planktonic food webs. However, evolutionary relationships of tintinnids are poorly known because molecular data of most groups within this order are lacking. In our study, the small subunit (SSU) rRNA genes representing 10 genera, 5 families of Tintinnida were sequenced, including the first SSU rRNA gene sequences for Coxliella, Dadayiella, Epiplocyloides, and Protorhabdonella, and phylogenetic trees were constructed to assess their intergeneric relationships. Phylogenies inferred from different methods showed that (1) Three newly sequenced Eutintinnus species fell into Eutintinnus clade forming a sister group to the clade containing Amphorides, Steenstrupiella, Amphorellopsis, and Salpingella; (2) Surprisingly, the genetic distances between Amphorides amphora and Amphorellopsis acuta population 1 was even smaller than that between the two populations of Amphorellopsis acuta, casting doubt on the validity of Amphorides and Amphorellopsis as presently defined; (3) The SSU rRNA sequences of Dadayiella ganymedes and Parundella aculeata were almost identical. Therefore, Parundella ganymedes novel combination is proposed; (4) Coxliella, which is currently assigned within Metacylididae, branched instead with some Tintinnopsis species. Furthermore, the validation of Coxliella, which was considered to be a "questionable" genus, was confirmed based on evidences from morphology, ecology, and molecular data; (5) Protorhabdonella and Rhabdonella showed rather low intergeneric distance and grouped together with strong support suggesting that Rhabdonellidae is a well-defined taxon; and (6) Epiplocyloides branched with species in Cyttarocylididae indicating their close relationship.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

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