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Find video protocols related to scientific articles indexed in Pubmed.
Dihydroxanthenones from the fermentation product of an endophytic fungus Gliomastix murorum.
J Asian Nat Prod Res
PUBLISHED: 11-14-2014
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Three new dihydroxanthones, muroxanthenones A-C (1-3), together with three known dihydroxanthones (4-6) were isolated from the fermentation products of an endophytic fungus Gliomastix murorum. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compound 3 showed high cytotoxicities against NB4 and PC3 cell with IC50 values of 2.2 and 2.8 ?M. The other compounds also showed moderate cytotoxicities for some tested cell lines with IC50 values between 4.1 and 9.5 ?M.
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Supramolecular assembly-induced yellow emission of 9,10-distyrylanthracene bridged bis(pillar[5]arene)s.
Chem. Commun. (Camb.)
PUBLISHED: 11-11-2014
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9,10-Distyrylanthracene has been introduced to bridge two pillarenes to form a dimeric host, which can assemble into a linear supramolecular polymer upon cooperatively binding to a neutral guest linker, exhibiting yellow fluorescence emission in solution and solid states.
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[Synergistic effect of hypertension and aging on left atrial volume and function].
Zhonghua Nei Ke Za Zhi
PUBLISHED: 11-08-2014
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To assess the effect of combined hypertension (HT) and aging on left atrial (LA) size and phasic function.
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[Establishment of breast cancer MDA-MB-231 cell line stably over-expressing human TOX high mobility group box family member 3].
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi
PUBLISHED: 11-07-2014
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Objective To construct the lentiviral expression vector of human TOX high mobility group box family member 3 (TOX3) gene and the MDA-MB-231 cell line which stably over-expresses TOX3 gene. Methods TOX3 gene was synthesized by the gene synthesis method and amplified by PCR, and then cloned into pLVEF-1a/GFP-Puro vector to construct pLVEF-1a/GFP-Puro-TOX3 lentiviral vector. After restriction enzyme analysis and sequence identification, the lentiviral vector was packaged and the titer was detected. The human breast cancer MDA-MB-231 cells were transfected with the recombinant lentiviral vector and cultured selectively by puromycin to acquire stably transfected cells. MDA-MB-231 cells which expressed GFP were observed by fluorescence microcopy. And the expression levels of TOX3 mRNA and protein in transfected MDA-MB-231 cells were detected by real-time quantitative PCR(qRT-PCR) and Western blotting, respectively. Results Restriction enzyme digestion and sequence analysis demonstrated that the lentiviral expression vectors of pLVEF-1a/GFP-Puro and pLVEF-1a/GFP-Puro-TOX3 were successfully constructed, and the viral titers were respectively 2×10(8) TU/mL and 1×10(8) TU/mL after lentiviral packaging. And after being transfected, more than 95% cells expressed GFP under a fluorescence microscope. The results of qRT-PCR and Western blotting showed that, when compared with the MDA-MB-231-NC negative control group, the expression of TOX3 mRNA and protein significantly increased in the MDA-MB-231-TOX3 group. Conclusion The study successfully constructed lentiviral expression vector of TOX3 gene and obtained MDA-MB-231 cell line stably over-expressing TOX3 gene by transfection with the recombinant vector.
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Dyssynchronous Pacing Triggers Endothelial-Mesenchymal Transition Through Heterogeneity of Mechanical Stretch in a Canine Model.
Circ. J.
PUBLISHED: 11-07-2014
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Background:Endothelial-mesenchymal transition (EndMT) plays a pivotal role in cardiac fibrosis. However, it is unclear whether EndMT is involved in dyssynchronous heart failure (DHF).Methods?and?Results:Twelve dogs received 3-week rapid right ventricular pacing (RVP) to develop DHF and then were randomly divided into a RVP group (n=6; RVP for another 3 weeks) and a biventricular pacing (BiVP) group (n=6; BiVP for 3 weeks), and another 6 dogs were in the control group. Contractile function in BiVP group was a little better than that in RVP group (P<0.05), but significant heart failure remained in 2 groups. RVP induced more significant cardiac fibrosis and higher collagen 1A2 expression in the left ventricular lateral wall (late-contracting and high-stress) than that in the anterior wall, and for those in the BiVP group, it was much lower. CD31, S100A4, ?-smooth muscle actin and collagen 1A2 were used to evaluate EndMT. EndMT levels, transforming growth factor-? (TGF-?)/snail signaling, collagen 1A2 and integrin ?1 expression were much higher in the endothelial cells from the RVP lateral wall than that from BiVP. In this in vitro study, cyclic stretch could independently induce EndMT and enhance the pro-EndMT effect of TGF-? in HUVECs, which could be partly blocked by integrin ?1 siRNA.Conclusions:RVP-induced DHF could aggravate fibrosis due to regional heterogeneity of mechanical stress, and it was better in the BiVP group where mechanical stress-induced EndMT might play a pivotal role through the integrin ?1 pathway.
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Next-Generation Digital PCR Measurement of Hepatitis B Virus Copy Number in Formalin-Fixed Paraffin-Embedded Hepatocellular Carcinoma Tissue.
Clin. Chem.
PUBLISHED: 11-02-2014
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Hepatocellular carcinoma (HCC) is strongly associated with hepatitis B virus (HBV) infection. False-negative results are common in routine serological tests and quantitative real-time PCR because of HBV surface antigen (HBsAg) variation and low HBV copy number. Droplet digital PCR (ddPCR), a next-generation digital PCR, is a novel, sensitive, and specific platform that can be used to improve HBV detection.
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Enhancing vitamin E bioaccessibility: factors impacting solubilization and hydrolysis of ?-tocopherol acetate encapsulated in emulsion-based delivery systems.
Food Funct
PUBLISHED: 10-15-2014
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Oil-soluble vitamins are often encapsulated within emulsion-based delivery systems to facilitate their incorporation into aqueous-based products. We have examined the influence of carrier oil type and simulated small intestinal fluid (SSIF) composition on the bioaccessibility of emulsified vitamin E using a gastrointestinal model. Oil-in-water emulsions containing vitamin E acetate were prepared using bile salts as emulsifier, and either long chain triacylglycerols (glyceryl trioleate, LCT) or medium chain triacylglycerols (glyceryl trioctanoate, MCT) as carrier oils. The addition of calcium (CaCl2) to the SSIF increased the extent of lipid digestion in LCT-emulsions, but had little impact in MCT-emulsions. The bioaccessibility of vitamin E increased in the presence of calcium and phospholipids (DOPC) in LCT-emulsions, but decreased in MCT-emulsions. The highest bioaccessibility (? 66%) was achieved for LCT-emulsions when the SSIF contained both calcium and phospholipids. The conversion of ?-tocopherol acetate to ?-tocopherol after in vitro digestion was considerably higher for LCT-emulsions when calcium ions were present in the SSIF, but was not strongly affected by SSIF composition for MCT-emulsions. In general, this research provides important information about the factors influencing the bioaccessibility of emulsified vitamin E, which could be used to design more effective emulsion-based delivery systems for increasing the oral bioavailability of this important bioactive component.
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Decreased N(6)-methyladenosine in peripheral blood RNA from Diabetic Patients Is Associated with FTO Expression Rather than ALKBH5.
J. Clin. Endocrinol. Metab.
PUBLISHED: 10-11-2014
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Context: N(6)-methyladenosine (m(6)A) modification plays a fundamental role in epigenetic regulation of the mammalian transcriptome. m(6)A can be demethylated by fat mass and obesity associated (FTO) protein and ALKBH5 protein. However, the importance of m(6)A alteration in type 2 diabetes mellitus (T2DM) has not been explored. Objective: To investigate whether m(6)A content was reduced in T2DM patients and whether m(6)A content was correlated with the mRNA expression levels of FTO and ALKBH5 genes. Methods: In this case-control study, peripheral blood samples were obtained from 88 T2DM patients and 92 healthy controls. For the diabetic animal model experiment, blood samples were obtained from 7 diabetic and 8 nondiabetic rats. A sensitive liquid chromatography- electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method was developed for the determination of m(6)A content in RNA, quantitative real-time PCR (qPCR) was used to examine the mRNA expression levels of FTO and ALKBH5 genes, and high-resolution melting (HRM) and DNA sequencing were used to detect FTO single nucleotide polymorphisms (SNPs). Results: Our results showed that m(6)A contents in RNA from T2DM patients and diabetic rats were significantly lower compared to the control groups (p = 2.6×10(-24) for T2DM patients; p = 0.001 for diabetic rats, respectively) and T2DM can be characterized by the content of m(6)A. The mRNA expression level of FTO was significantly higher in T2DM patients than that of the controls (p=0.0007), and associated with the risk of T2DM (odds ratio (OR) 2.797, 95% confidence interval (CI) 1.452 - 5.389, p= 0.002). Moreover, m(6)A contents were correlated with FTO mRNA expression. Conclusions: These data suggest that the increased mRNA expression of FTO could be responsible for the reduction of m(6)A in T2DM, which may further increase the risk of complications of T2DM. Low m(6)A should be investigated further as a novel potential biomarker of T2DM.
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[Application of different technologies for distinguishing true and pseudo mosaicisms during prenatal diagnosis].
Zhonghua Yi Xue Yi Chuan Xue Za Zhi
PUBLISHED: 10-10-2014
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To use different technologies to distinguish true and pseudo mosaicisms among cultured amniocytes in order to attain more accurate diagnosis.
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Analysis of factors influencing hydration site prediction based on molecular dynamics simulations.
J Chem Inf Model
PUBLISHED: 10-07-2014
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Water contributes significantly to the binding of small molecules to proteins in biochemical systems. Molecular dynamics (MD) simulation based programs such as WaterMap and WATsite have been used to probe the locations and thermodynamic properties of hydration sites at the surface or in the binding site of proteins generating important information for structure-based drug design. However, questions associated with the influence of the simulation protocol on hydration site analysis remain. In this study, we use WATsite to investigate the influence of factors such as simulation length and variations in initial protein conformations on hydration site prediction. We find that 4 ns MD simulation is appropriate to obtain a reliable prediction of the locations and thermodynamic properties of hydration sites. In addition, hydration site prediction can be largely affected by the initial protein conformations used for MD simulations. Here, we provide a first quantification of this effect and further indicate that similar conformations of binding site residues (RMSD < 0.5 Å) are required to obtain consistent hydration site predictions.
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The Prox1-Vegfr3 feedback loop maintains the identity and the number of lymphatic endothelial cell progenitors.
Genes Dev.
PUBLISHED: 10-03-2014
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The mammalian lymphatic vasculature is important for returning fluids from the extracellular tissue milieu back to the blood circulation. We showed previously that Prox1 dosage is important for the development of the mammalian lymphatic vasculature. The lack of Prox1 activity results in the complete absence of lymphatic endothelial cells (LECs). In Prox1 heterozygous embryos, the number of LECs is reduced because of a decrease in the progenitor pool in the cardinal vein. This reduction is caused by some progenitor cells being unable to maintain Prox1 expression. In this study, we identified Vegfr3, the cognate receptor of the lymphangiogenic growth factor Vegfc, as a dosage-dependent, direct in vivo target of Prox1. Using various mouse models, we also determined that Vegfr3 regulates Prox1 by establishing a feedback loop necessary to maintain the identity of LEC progenitors and that Vegfc-mediated activation of Vegfr3 signaling is necessary to maintain Prox1 expression in LEC progenitors. We propose that this feedback loop is the main sensing mechanism controlling the number of LEC progenitors and, as a consequence, the number of budding LECs that will form the embryonic lymphatic vasculature.
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[Effects of flower bud removal and artificial pollination on growth and yield of Tulipa edulis].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 10-03-2014
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The study was conducted to explore the response of growth and yield of Tulipa edulis to flower bud removal and artificial pollination. And flower bud removal and artificial pollination were carried out in the squaring period and bloom stage respectively. The morphological index and biomass indicators were determined and the yield was counted in harvest time. Result showed that flower bud removal was beneficial to the growth of T. edulis, resulting in increasing growth index, biomass as well as the yield of bulb. The diameter and dry weight of T. edulis fruit by artificial pollination were increased significantly compared with the control. Seed setting percentage increased to 100%, and the number of seed as well as the single grain weight increased by 69.03% and 16.48%, respectively, which did not significantly affect the bulb production. In conclusion, Flower bud removal treatment accelerates bulb biomass increase, so as to improve its yield. Artificial pollination raised significantly seed setting percentage, seed number as well as the single grain weight.
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R-spondin1 is a novel hormone mediator for mammary stem cell self-renewal.
Genes Dev.
PUBLISHED: 09-26-2014
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Signals from the niche play pivotal roles in regulating adult stem cell self-renewal. Previous studies indicated that the steroid hormones can expand mammary stem cells (MaSCs) in vivo. However, the facilitating local niche factors that directly contribute to the MaSC expansion remain unclear. Here we identify R-spondin1 (Rspo1) as a novel hormonal mediator in the mammary gland. Pregnancy and hormonal treatment up-regulate Rspo1 expression. Rspo1 cooperates with another hormonal mediator, Wnt4, to promote MaSC self-renewal through Wnt/?-catenin signaling. Knockdown of Rspo1 and Wnt4 simultaneously abolishes the stem cell reconstitution ability. In culture, hormonal treatment that stimulates the expression of both Rspo1 and Wnt4 can completely substitute for exogenous Wnt proteins, potently expand MaSCs, and maintain their full development potential in transplantation. Our data unveil the intriguing concept that hormones induce a collaborative local niche environment for stem cells.
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Red light and carbon dioxide differentially affect growth, lipid production, and quality in the microalga, Ettlia oleoabundans.
Appl. Microbiol. Biotechnol.
PUBLISHED: 09-16-2014
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Ettlia oleoabundans, a freshwater unicellular green microalga, was grown under different light qualities ± carbon dioxide-enriched air to determine the combined effects on growth and lipid production of this oleaginous species. Keeping total light intensity constant, when a portion of the cool white was replaced by red, volumetric lipid yield increased 2.8-fold mainly due to the greater yield of oleic acid, a desirable biodiesel precursor. Only 30 min of red light treatment was sufficient to increase lipid yield and quality to the same level as cultures provided red light for >14 days, indicating the potential role of red light in stimulating lipid production of this species. Carbon dioxide enrichment via air sparging enhanced exponential growth, carbon conversion efficiency, and nutrient consumption. Together, these results showed that light quality plays an important role in microalgal lipid production. Adjustment in light quality and gas delivery efficiency with carbon dioxide enrichment improved lipid yield and quality in this and possibly other oleaginous algal species.
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Dab2 attenuates brain injury in APP/PS1 mice via targeting transforming growth factor-beta/SMAD signaling.
Neural Regen Res
PUBLISHED: 09-11-2014
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Transforming growth factor-beta (TGF-?) type II receptor (T?RII) levels are extremely low in the brain tissue of patients with Alzheimer's disease. This receptor inhibits TGF-?1/SMAD signaling and thereby aggravates amyolid-beta deposition and neuronal injury. Dab2, a specific adapter protein, protects T?RII from degradation and ensures the effective conduction of TGF-?1/SMAD signaling. In this study, we used an adenoviral vector to overexpress the Dab2 gene in the mouse hippocampus and investigated the regulatory effect of Dab2 protein on TGF-?1/SMAD signaling in a mouse model of Alzheimer's disease, and the potential neuroprotective effect. The results showed that the T?RII level was lower in APP/PS1 mouse hippocampus than in normal mouse hippocampus. After Dab2 expression, hippocampal T?RII and p-SMAD2/3 levels were significantly increased, while amyloid-beta deposition, microglia activation, tumor necrosis factor-? and interleulin-6 levels and neuronal loss were significantly attenuated in APP/PS1 mouse brain tissue. These results suggest that Dab2 can exhibit neuroprotective effects in Alzheimer's disease by regulating TGF-?1/SMAD signaling.
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Integrative analysis of transcriptomic and metabolomic profiling of ascites syndrome in broiler chickens induced by low temperature.
Mol Biosyst
PUBLISHED: 09-03-2014
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Ascites syndrome (AS) still has an unacceptably high incidence rate in both humans and animals although there have been many studies on AS. To continue our previous pathological and biochemical investigation on the underlying mechanisms of AS incidence in broiler chickens, cutting-edge technologies including RNA-seq and metabolimics were used by directly comparing AS chickens and healthy controls. The RNA-seq analysis in the liver identified 390 differentially expressed genes (DEGs), among which 212 genes were up-regulated and 178 genes were down-regulated in the AS group compared to the control. For the down-regulated DEGs, further gene ontology (GO) analysis suggested that lipid metabolism, cell differentiation, enzyme linked receptor protein signaling pathway and steroid biosynthesis pathway were significantly enriched. For up-regulated DEGs, the cholesterol metabolic process has the lowest p value (0.000966) of fold enrichment while the cholesterol biosynthetic process has the highest fold enrichment (46.67). The metabolomic analysis of serum revealed statistically significant changes in the concentrations of LysoPC(20?:?4), LysoPC(16?:?0), LysoPC(18?:?0), LysoPC(18?:?1), LysoPC(18?:?2), PC(14?:?1/20?:?1), PC(20?:?4/18?:?0), PC(14?:?1/22?:?1), dihydroxyacetone, indoleacrylic acid, ursodeoxycholic acid, l-valine, and l-tryptophan. The integrative analysis of transcriptome and metabolome indicated that two biological pathways of tryptophan biosynthesis and metabolism, and glycerophospholipid metabolism may contribute to the induction of AS in broilers. These findings have provided novel insights into our understanding of molecular mechanisms of AS incidence in broilers.
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[Relationship between high normal blood pressure and carotid artery atherosclerosis in Beijing residents].
Zhonghua Xin Xue Guan Bing Za Zhi
PUBLISHED: 08-29-2014
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To analyze the relationship between normal high blood pressure and carotid artery atherosclerosis.
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Mussel-inspired one-step adherent coating rich in amine groups for covalent immobilization of heparin: hemocompatibility, growth behaviors of vascular cells, and tissue response.
ACS Appl Mater Interfaces
PUBLISHED: 08-18-2014
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Heparin, an important polysaccharide, has been widely used for coatings of cardiovascular devices because of its multiple biological functions including anticoagulation and inhibition of intimal hyperplasia. In this study, surface heparinization of a commonly used 316L stainless steel (SS) was explored for preparation of a multifunctional vascular stent. Dip-coating of the stents in an aqueous solution of dopamine and hexamethylendiamine (HD) (PDAM/HD) was presented as a facile method to form an adhesive coating rich in primary amine groups, which was used for covalent heparin immobilization via active ester chemistry. A heparin grafting density of about 900 ng/cm(2) was achieved with this method. The retained bioactivity of the immobilized heparin was confirmed by a remarkable prolongation of the activated partial thromboplastin time (APTT) for about 15 s, suppression of platelet adhesion, and prevention of the denaturation of adsorbed fibrinogen. The Hep-PDAM/HD also presented a favorable microenvironment for selectively enhancing endothelial cell (EC) adhesion, proliferation, migration and release of nitric oxide (NO), and at the same time inhibiting smooth muscle cell (SMC) adhesion and proliferation. Upon subcutaneous implantation, the Hep-PDAM/HD exhibited mitigated tissue response, with thinner fibrous capsule and less granulation formation compared to the control 316L SS. This number of unique functions qualifies the heparinized coating as an attractive alternative for the design of a new generation of stents.
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Effects of positive end-expiratory pressure on intracranial pressure in mechanically ventilated dogs under hyperbaric oxygenation.
Undersea Hyperb Med
PUBLISHED: 08-12-2014
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Mechanical ventilation with positive end-expiratory pressure (PEEP) has been advocated as an essential life support for critical patients. However, its side effect, which is demonstrated by an elevation of intracranial pressure (ICP) under normobaric (NBO2) conditions, is potentially detrimental to patients. Hyperbaric oxygen (HBO2) therapy, on the other hand, is frequently applied for the same group of patients, and its efficacy is shown by maintaining a higher PaO2 and a reduced ICP. Our study investigated the effect of HBO2 and NBO2 on ICP with or without PEEP ventilation on healthy dogs by comparing cerebrospinal fluid pressure (CSFP) and concluded that the elevation of PEEP resulted in a significant increase of ICP (CSFP) under both conditions (p < 0.05). HBO2 leads to a lower ICP increase compared to the NBO2 group. Under the same level of PEEP, the joint use of PEEP and HBO2 is safe and highly practical in clinical medicine.
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Enhanced deacidification activity in Schizosaccharomyces pombe by genome shuffling.
Yeast
PUBLISHED: 08-07-2014
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A problem frequently occurring in making some kinds of wines, particularly Vitis quinquangularis Rehd wine, is the presence of malic acid at high concentrations, which is detrimental to the quality of wines. Thus, there is a need of the ways for effectively reducing the malic acid levels in wine. This study aimed to generate shuffled fusants of Schizosaccharomyces pombe with enhanced deacidification activity for reducing the excessive malic acid content in wine. Sz. pombe CGMCC 2.1628 was used as the original strain. The starting mutant population was generated by UV treatment. The mutants with higher deacidification activity were selected and subjected to recursive protoplast fusion. The resulting fusants were screened by using the indicator of malic acid concentration of fermentation supernatants on 96-well microtitre plates, measured with bromocresol green. After three rounds of genome shuffling, the best-performing fusant, named GS3-1, was obtained. Its deacidification activity (consumed 4.78?g/l malic acid within 10?days) was increased by 225.2% as compared to that of original strain. In the Vitis quinquangularis Rehd wine fermentation test, GS3-1 consumed 4.0?g/l malic acid during the whole cycle of fermentation, providing up to 185.7% improvement in malic acid consumption compared with that of the original strain. This study shows that GS3-1 has great potential for improving the quality of Vitis quinquangularis Rehd wine. Copyright © 2014 John Wiley & Sons, Ltd.
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The chemotherapeutic potential of PEG-b-PLGA copolymer micelles that combine chloroquine as autophagy inhibitor and docetaxel as an anti-cancer drug.
Biomaterials
PUBLISHED: 08-07-2014
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Micelles may be the nanocarrier that is used most often in the area of nanomedicine due to its promising performance and technical simplicity. However, like the original drugs, micellar formulation may arouse intracellular autophagy that deteriorates their advantages for efficient drug delivery. There has been no report in the literature that involves the fate of micelles after successfully internalized into the cancer cells. In this study, we show by using docetaxel-loaded PEG-b-PLGA micelles as a micellar model that the micelles do arouse intracellular autophagy and are thus subject to degradation through the endo-lysosome pathway. Moreover, we show that co-administration of the micellar formulation with autophagy inhibitor such as chloroquine (CQ) could significantly enhance their therapeutic effects. The docetaxel-loaded PEG-b-PLGA micelles are formulated by the membrane dialysis method, which are of 7.1% drug loading and 72.8% drug encapsulation efficiency in a size range of around 40 nm with narrow size distribution. Autophagy degradation and inhibition are investigated by confocal laser scanning microscopy with various biological makers. We show that the IC50 values of the drug formulated in the PEG-b-PLGA micelles after 24 h treatment MCF-7 cancer cells with no autophagy inhibitor or in combination with CQ were 22.30 ± 1.32 and 1.75 ± 0.43 ?g/mL respectively, which indicated a 12-fold more efficient treatment with CQ. The in vivo investigation further confirmed the advantages of such a strategy. The findings may provide advanced knowledge for development of nanomedicine for clinical application.
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Cloning and characterization of a cold-adapted endo-1,5-?-L-arabinanase from Paenibacillus polymyxa and rational design for acidic applicability.
J. Agric. Food Chem.
PUBLISHED: 08-06-2014
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AbnZ1, with optimal pH of 6.0 and optimal temperature of 40 °C, is a cold-adapted endo-1,5-?-L-arabinanase encoded by the gene abnZ1 from Paenibacillus polymyxa Z6. The specific activity of AbnZ1 remained 54.1% of maximum at 5 °C. To apply AbnZ1 in acidic conditions, three basic hsitidine (His) residues, His(48), His(218), and His(297), around the catalytic domain were selected as mutation sites, which were replaced with Asp, Glu, Arg, and Lys, respectively, to yield 12 mutants, H48D/E/R/K, H218D/E/R/K, and H297D/E/R/K. The optimum pH of mutant H218D shifted toward the acidic direction by 0.5 unit, and the relative activity was enhanced from 20.4 to 55.7% at pH 5.0. Furthermore, the specific activity of H218D in optimal conditions was 82.6 U/mg versus that of wild type, 73.4 U/mg, and the K(m) decreased from 11.9 to 7.1 mg/mL. This work provided an arabinanase candidate for juice clarification and pectin extraction.
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Self-repairable polyurethane networks by atmospheric carbon dioxide and water.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 08-05-2014
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Sugar moieties were incorporated into cross-linked polyurethane (PUR) networks in an effort to achieve self-repairing in the presence of atmospheric carbon dioxide (CO2 ) and water (H2 O). When methyl-?-D-glucopyranoside (MGP) molecules are reacted with hexamethylene diisocyanate trimer (HDI) and polyethylene glycol (PEG) to form cross-linked MGP-polyurethane (PUR) networks, these materials are capable of self-repairing in air. This process requires atmospheric amounts of CO2 and H2 O, thus resembling plant behavior of carbon fixation during the photosynthesis cycle. Molecular processes responsible for this unique self-repair process involve physical diffusion of cleaved network segments as well as the formation of carbonate and urethane linkages. Unlike plants, MGP-PUR networks require no photo-initiated reactions, and they are thus capable of repair in darkness under atmospheric conditions.
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Dithienylethene-based rotaxanes: synthesis, characterization and properties.
Org. Biomol. Chem.
PUBLISHED: 08-01-2014
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The photochromic materials have been widely applied in many fields. In this article, we report a class of photochromic ammoniums with a dithienylethene backbone. They were utilized as templates to construct mechanically interlocked rotaxanes and pseudorotaxanes showing photo-responsive behavior by template-directed clipping reaction and the threading approach. The structures of novel rotaxanes were well defined. It is worth mentioning that the single crystal structure of [3]rotaxane containing two N-hetero crown ether units was obtained. Their photoisomerization behavior was investigated. These N-hetero crown ether-based rotaxanes displayed good reversibility and similar photochromic behaviors to their corresponding ammoniums when they underwent UV/vis photoirradiation. Interestingly, the cucurbit[6]uril-based pseudorotaxane showed better photoisomerization than its corresponding ammonium and those of N-hetero crown ether-based rotaxanes.
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Involvement of fish signal transducer and activator of transcription 3 (STAT3) in SGIV replication and virus induced paraptosis.
Fish Shellfish Immunol.
PUBLISHED: 07-25-2014
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Signal transducer and activator of transcription 3 (STAT3) is an important transcription factor which plays crucial roles in immune regulation, inflammation, cell proliferation, transformation, and other physiological processes of the organism. In this study, a novel STAT3 gene from orange spotted grouper (Ec-STAT3) was cloned and characterized. Bioinformatic analysis revealed that full-length of Ec-STAT3 was 3105-bp long and contained a 280-bp 5'UTR, a 470-bp 3'UTR, and a 2355-bp open reading frame (ORF) that encoded a 784-amino acid peptide. The deduced protein of Ec-STAT3 showed 98% identity to that of turbot (Scophthalmus maximus). Amino acid alignment showed that Ec-STAT3 contained four conserved domains, including a protein interaction domain, a coiled coil domain, a DNA binding domain, and an SH2 domain. Quantitative real-time PCR analysis showed that the highest expression level was detected in the liver, followed by skin and spleen. After injection with Singapore grouper iridovirus (SGIV), the transcript of Ec-STAT3 in spleen was increased significantly. To further explore the function of Ec-STAT3, we investigated the roles of Ec-STAT3 in SGIV infection in vitro. Immune fluorescence analysis indicated that SGIV infection altered the distribution of phosphorylated Ec-STAT3 in nucleus, and a small part of phosphorylated Ec-STAT3 was associated with virus assembly sites, suggesting that Ec-STAT3 might be important for SGIV infection. Using STAT3 specific inhibitor, S3I-201, we found that inhibition of Ec-STAT3 activation decreased the SGIV replication significantly. Moreover, inhibition of Ec-STAT3 activation obviously altered SGIV infection induced cell cycle arrest and the expression of pro-survival genes, including Bcl-2, Bcl-xL and Bax inhibitor. Together, our results firstly demonstrated the critical roles of fish STAT3 in DNA virus replication and virus induced paraptosis, but also provided new insights into the mechanism of iridovirus pathogenesis.
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Berberine attenuates autophagy in adipocytes by targeting BECN1.
Autophagy
PUBLISHED: 07-23-2014
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The lysosomal degradation pathway, autophagy, is essential for the maintenance of cellular homeostasis. Recently, autophagy has been demonstrated to be required in the process of adipocyte conversion. However, its role in mature adipocytes under physiological and pathological conditions remains unclear. Here, we report a major function of BECN1 in the regulation of basal autophagy in mature adipocytes. We also show that berberine, a natural plant alkaloid, inhibits basal autophagy in adipocytes and adipose tissue of mice fed a high-fat diet via downregulation of BECN1 expression. We further demonstrate that berberine has a pronounced effect on the stability of Becn 1 mRNA through the Mir30 family. These findings explore the potential of BECN1 as a key molecule and a drug target for regulating autophagy in mature adipocytes.
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A hole-conductor-free, fully printable mesoscopic perovskite solar cell with high stability.
Science
PUBLISHED: 07-19-2014
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We fabricated a perovskite solar cell that uses a double layer of mesoporous TiO2 and ZrO2 as a scaffold infiltrated with perovskite and does not require a hole-conducting layer. The perovskite was produced by drop-casting a solution of PbI2, methylammonium (MA) iodide, and 5-ammoniumvaleric acid (5-AVA) iodide through a porous carbon film. The 5-AVA templating created mixed-cation perovskite (5-AVA)x(MA)1- xPbI3 crystals with lower defect concentration and better pore filling as well as more complete contact with the TiO2 scaffold, resulting in a longer exciton lifetime and a higher quantum yield for photoinduced charge separation as compared to MAPbI3. The cell achieved a certified power conversion efficiency of 12.8% and was stable for >1000 hours in ambient air under full sunlight.
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Fully printable transparent monolithic solid-state dye-sensitized solar cell with mesoscopic indium tin oxide counter electrode.
Phys Chem Chem Phys
PUBLISHED: 07-18-2014
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We present a new transparent monolithic mesoscopic solid-state dye-sensitized solar cell based on trilamellar films of mesoscopic TiO2 nanocrystalline photoanode, a ZrO2 insulating layer and an indium tin oxide counter electrode (ITO-CE), which were screen-printed layer by layer on a single substrate. When the thickness of the ITO-CE was optimized to 2.1 ?m, this very simple and fully printable solid-state DSSC with D102 dye and spiro-OMeTAD hole transport materials presents efficiencies of 1.73% when irradiated from the front side and 1.06% when irradiated from the rear side under a standard simulated sunlight condition (AM 1.5 Global, 100 mW cm(-2)). Higher parameters could be expected with a better transparent mesoscopic counter electrode and hole conductor for the printable monolithic mesoscopic solid-state DSSC.
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Association of body size and body fat distribution with uterine fibroids among Chinese women.
J Womens Health (Larchmt)
PUBLISHED: 07-11-2014
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Uterine fibroids are the most common tumors in reproductive women. The present study aims to identify the relationship between uterine fibroids and body size and body fat distribution among Chinese women.
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Ditopic pillar[5]arene-based fluorescence enhancement material mediated by [c2]daisy chain formation.
Chem. Commun. (Camb.)
PUBLISHED: 07-11-2014
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Ditopic pillarene-based fluorescence enhancement material induced by [c2]daisy chain formation has been successfully fabricated. The highly fluorescent smart material exhibits great adaptivity and can act as a multi-responsive supramolecular sensor.
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Origin and nature of spontaneous shape fluctuations in "small" nanoparticles.
ACS Nano
PUBLISHED: 07-11-2014
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Normally chemically inert materials such as Au have been found to be catalytically active in the form of particles whose size is about 1 nm. Direct and indirect observations of various types of metal nanoparticles (NPs) in this size range, under catalytically relevant conditions for fuel-cell operation and catalysis, have indicated that such "small" particles can exhibit large spontaneous shape fluctuations and significant changes in shape and chemical activity in response to alterations in environmental conditions. NPs also normally exhibit facile coalescence when in proximity, impacting their stability and reactivity in applications. We perform molecular dynamics simulations on Ni nanoparticles, a commonly used NP in catalytic applications and carbon nanotube growth, in the ?1 nm size regime where large-scale shape fluctuations have been observed experimentally. An analysis of the large-scale shape fluctuations observed in our simulations of these "small" NPs indicates that they are accompanied by collective motion of Ni atoms through the NP center, and we quantify these dynamic structures and their impact on NP shape. In contrast, stringlike collective atomic motion is confined to the NP interfacial region of NPs having a diameter greater than a few nanometers, and correspondingly, the overall NP shape remains roughly spherical, a case studied in our prior Ni NP simulations. Evidently, the large spontaneous NP shape fluctuations reflect a change in character of the collective atomic dynamics when the NPs become critically small in size.
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A facile in vitro model to study rapid mineralization in bone tissues.
Biomed Eng Online
PUBLISHED: 07-07-2014
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Mineralization in bone tissue involves stepwise cell-cell and cell-ECM interaction. Regulation of osteoblast culture microenvironments can tailor osteoblast proliferation and mineralization rate, and the quality and/or quantity of the final calcified tissue. An in vitro model to investigate the influencing factors is highly required.
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The XIAP inhibitor Embelin enhances TRAIL-induced apoptosis in human leukemia cells by DR4 and DR5 upregulation.
Tumour Biol.
PUBLISHED: 07-05-2014
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The present study was designed to explore the effects of low-toxicity Embelin on TRAIL-induced apoptosis and its possible mechanism in human leukemia cells. Our study showed that low-toxicity Embelin enhanced TRAIL-induced apoptosis through DR4 and DR5 upregulation and caspase activation in HL-60 cells. Pan-caspase inhibitor Z-VAD-FMK inhibited cell apoptosis induced by TRAIL alone or combined with low-toxicity Embelin, which indicated the cytotoxic effect is mediated by caspase-dependent apoptosis. Although Embelin is an X chromosome-linked inhibitor-of-apoptosis protein (XIAP) inhibitor, an XIAP independent effect on cell death was detected in HL-60 cells exposed to low-toxicity Embelin and TRAIL. Low-toxicity Embelin upregulated DR4 and DR5 expression to enhance TRAIL-induced apoptosis. The sensitizing effects of Embelin on TRAIL-induced apoptosis were markedly attenuated when DR4/DR5 was knocked down. These data suggested that low-toxicity Embelin enhanced TRAIL-induced cell apoptosis through DR4 and DR5 upregulation, indicating that combination of low-toxicity Embelin and TRAIL may become as a potential antileukemia strategy.
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Synthesis of pt-ni alloy nanocrystals with high-index facets and enhanced electrocatalytic properties.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 06-23-2014
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The shape-controlled synthesis of multicomponent metal nanocrystals (NCs) bounded by high-index facets (HIFs) is of significant importance in the design and synthesis of high-activity catalysts. We report herein the preparation of Pt-Ni alloy NCs by tuning their shape from concave-nanocubic (CNC) to nanocubic and hexoctahedral (HOH). Owing to the synergy of the HIFs and the electronic effect of the Pt-Ni alloy, the as-prepared CNC and HOH Pt-Ni alloy NCs exhibited excellent catalytic properties for the electrooxidation of methanol and formic acid, as well as for the oxygen reduction reaction (ORR).
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Stimuli-responsive blue fluorescent supramolecular polymers based on a pillar[5]arene tetramer.
Chem. Commun. (Camb.)
PUBLISHED: 06-18-2014
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A tetraphenylethene-bridged pillarene tetramer with aggregation-induced emission properties forms an A4/B2-type supramolecular polymer and a gel with a symmetric neutral guest linker, showing a remarkable fluorescence emission enhancement in solution and the solid state and a good responsiveness to temperature and solvent composition.
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Self-assembly and applications of poly(glycidyl methacrylate)s and their derivatives.
Chem. Commun. (Camb.)
PUBLISHED: 06-04-2014
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In this feature article, we give an overview of the preparation and application of self-assembled architectures based on an emerging area of polymers, i.e., poly(glycidyl methacrylate)s (PGMAs) and their derivatives. A series of PGMA-based aggregates and hybrids, such as micelles, reverse micelles, capsules, nanoparticles, and inorganic-organic hybrid materials, has been constructed, and diverse morphologies were formed, driven by hydrophobic interactions, hydrogen bonding, ionic complexation, host-guest interactions, etc. In particular, the assemblies have shown great potential applications as drug vectors, gene vectors, solubilizing agents, antimicrobial agent, and so forth. Herein, the general guidelines are elaborately selected from literature examples and partially from our own. Although still in its infancy, self-assembly of PGMA-based polymers is expected to become a hot topic in polymer chemistry and materials science.
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2,4,5-Trisubstituted thiazole derivatives: a novel and potent class of non-nucleoside inhibitors of wild type and mutant HIV-1 reverse transcriptase.
Eur J Med Chem
PUBLISHED: 04-24-2014
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Novel 2,4,5-trisubstituted thiazole derivatives (TSTs) were designed and synthesized as HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs). Among the thirty-eight synthesized target compounds, thirty TSTs showed potent inhibition against HIV-1 replication in wild type HIV-1 at submicromolar concentrations (from 0.046 to 9.59 ?M). Compounds 21, 23 and 24 were also tested on seven NNRTI-resistant HIV-1 strains, and all exhibited inhibitory effects with fold changes in IC50 ranging from 2.6 to 111, which were better than those of nevirapine (15.6-fold-371-fold). Docking simulations of compound 24 revealed a reasonable mechanism for the binding mode, and three-dimensional quantitative structure activity relationship (3-DQSAR) studies on this novel series of TST further elucidated the structure-activity relationship (SAR). The results suggested the great potential of TSTs as a novel class of NNRTIs with antiviral efficacy and a good resistance profile.
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Contribution of carboxylesterase and cytochrome P450 to the bioactivation and detoxification of isocarbophos and its enantiomers in human liver microsomes.
Toxicol. Sci.
PUBLISHED: 04-20-2014
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Organophosphorus pesticides are the most widely used pesticides in modern agricultural systems to ensure good harvests. Isocarbophos (ICP), with a potent acetylcholinesterase inhibitory effect is widely utilized to control a variety of leaf-eating and soil insects. However, the characteristics of the bioactivation and detoxification of ICP in humans remain unclear. In this study, the oxidative metabolism, esterase hydrolysis, and chiral inversion of ICP in human liver microsomes (HLMs) were investigated with the aid of a stereoselective LC/MS/MS method. The depletion of ICP in HLMs was faster in the absence of carboxylesterase inhibitor (BNPP) than in the presence of NADPH and BNPP, with t1/2 of 5.2 and 90 min, respectively. Carboxylesterase was found to be responsible for the hydrolysis of ICP, the major metabolic pathway. CYP3A4, CYP1A2, CYP2D6, CYP2C9, and CYP2C19 were all involved in the secondary metabolism pathway of desulfuration of ICP. Flavin-containing monooxygenase (FMO) did not contribute to the clearance of ICP. The hydrolysis and desulfuration of (±)ICP, (+)ICP, and (-)ICP in HLMs follow Michaelis-Menten kinetics. Individual enantiomers of ICP and its oxidative desulfuration metabolite isocarbophos oxon (ICPO) were found to be inhibitors of acetylcholinesterases at different extents. For example, (±)ICPO is more potent than ICP (IC50 0.031?M vs. 192?M), whereas (+)ICPO is more potent than (-)ICPO (IC50 0.017?M vs. 1.55?M). Given the finding of rapid hydrolysis of ICP and low abundance of oxidative metabolites presence in human liver, the current study highlights that human liver has a greater capacity for detoxification of ICP.
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Malignant adenomyoepithelioma combined with adenoid cystic carcinoma of the breast: a case report and literature review.
Diagn Pathol
PUBLISHED: 04-16-2014
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Malignant adenomyoepithelioma and adenoid cystic carcinoma are both rare malignant epithelial-myoepithelial tumors of the breast. We report a very rare case with a malignant adenomyoepithelioma combining with adenoid cystic carcinoma in a single mass.
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Pillar[5]arene-Based Supramolecular Organic Frameworks for Highly Selective CO2 -Capture at Ambient Conditions.
Adv. Mater. Weinheim
PUBLISHED: 04-13-2014
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Low-density, solid-state, porous supramolecular organic frameworks are constructed using pillarenes. The frameworks have a honeycomb-like structure, permanent porosity, high thermal stability, and selective and reversible sorption properties toward CO2 . The exceptionally selective CO2 -sorption properties (375/1, 339/1) of one framework over N2 and CH4 indicate potential applications in CO2 -capture for post-combustion power plants and natural gas sweetening.
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Amino acid deprivation disrupts barrier function and induces protective autophagy in intestinal porcine epithelial cells.
Amino Acids
PUBLISHED: 04-06-2014
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The integrity of intestinal barrier is essential for the absorption of nutrients and health in humans and animals. Dysfunction of the mucosal barrier is associated with increased gut permeability and development of various gastrointestinal diseases. Aside from serving as substrates for protein biosynthesis, amino acids also maintain the health of intestinal mucosal barrier. However, the underlying mechanisms remain unclear. We aimed to determine the effect and mechanism of non-essential amino acid (NEAA) deprivation on intestinal tight junction permeability using porcine intestinal epithelial cells as a model. We found that NEAA deprivation led to an impairment of barrier function as evidenced by increased permeability, decreased trans-epithelial resistance, and decreased expression of tight junction proteins claudin-1 and ZO-1. Importantly, NEAA deprivation induced both apoptosis and autophagy as shown by caspase-3 activation, and poly ADP-ribose polymerase cleavage; and LC3II lipidation and p62 degradation, hallmarks of apoptosis and autophagy, respectively. Importantly, we showed that the autophagy induced by NEAA deprivation counteracts apoptosis. Abrogation of autophagy by 3-methyladenine enhanced NEAA deprivation-induced barrier dysfunction and apoptosis; whereas, activation of autophagy by rapamycin partially rescued NEAA deprivation-induced barrier dysfunction and apoptosis. Taken together, our results demonstrate a critical role of NEAA on the mucosal integrity by regulating cell death and survival signaling pathways.
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Contributions of nonleaf organs to the yield of cotton grown with different water supply.
ScientificWorldJournal
PUBLISHED: 04-01-2014
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The objectives of this experiment were (i) to determine the effect of water supply on the photosynthetic capacity of leaves, bracts, capsule walls, and stalks of cotton at different growth stages and (ii) to determine the contributions of these nonleaf organs to whole plant photosynthesis. Water deficit reduced the total surface area per plant but increased the proportion of nonleaf to total plant surface area. Net photosynthetic rates of leaves declined rapidly beginning 25 days after anthesis. In contrast, the net photosynthetic rates of bracts and capsule walls were insensitive to soil moisture stress and decreased by a small amount between 25 and 45 days after anthesis. The relative contribution of bracts and stalks to canopy apparent photosynthesis (CAP) increased under water deficit conditions. Cotton seed weight in the conventional irrigation treatment decreased by 10.1-29.7% when the bolls (capsule walls plus bracts) were darkened and by 5.3-9.9% when the stalks were darkened. On a percentage basis, both boll photosynthesis and stalk photosynthesis contributed more to seed weight when the plants were grown under water deficit conditions rather than nondeficit conditions. In conclusion, nonleaf organs contribute significantly to yield when cotton plants are under water stress during late growth stages.
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Polymorphisms of peroxisome proliferator-activated receptors and survival of lung cancer and upper aero-digestive tract cancers.
Lung Cancer
PUBLISHED: 03-31-2014
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Peroxisome proliferator-activated receptors (PPARs) are transcriptional factors involved in several biological processes such as inflammation, cancer growth, progression and apoptosis that are important in lung and upper aero-digestive tract (UADT) cancer outcomes. Nonetheless, there are no published studies of the relationship between PPARs gene polymorphisms and survival of patients with lung cancer or UADT cancers.
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De novo sequencing, assembly, and analysis of the Taxodium 'Zhongshansa' roots and shoots transcriptome in response to short-term waterlogging.
BMC Plant Biol.
PUBLISHED: 03-25-2014
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Taxodium is renowned for its strong tolerance to waterlogging stress, thus it has great ecological and economic potential. However, the scant genomic resources in genus Taxodium have greatly hindered further exploration of its underlying flood-tolerance mechanism. Taxodium 'Zhongshansa' is an interspecies hybrid of T. distichum and T. mucronatum, and has been widely planted in southeastern China. To understand the genetic basis of its flood tolerance, we analyzed the transcriptomes of Taxodium 'Zhongshansa' roots and shoots in response to short-term waterlogging.
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Efficient syntheses of pillar[6]arene-based hetero[4]rotaxanes using a cooperative capture strategy.
Chem. Commun. (Camb.)
PUBLISHED: 03-24-2014
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While a single pillar[6]arene ring, nestling between two cucurbit[6]uril rings in a series of three hetero[4]rotaxanes, is conformationally mobile in solution, it adopts the energetically most favourable conformation with local C3V symmetry in the solid state.
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Switchable host-guest systems on surfaces.
Acc. Chem. Res.
PUBLISHED: 03-17-2014
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CONSPECTUS: For device miniaturization, nanotechnology follows either the "top-down" approach scaling down existing larger-scale devices or the "bottom-up' approach assembling the smallest possible building blocks to functional nanoscale entities. For synthetic nanodevices, self-assembly on surfaces is a superb method to achieve useful functions and enable their interactions with the surrounding world. Consequently, adaptability and responsiveness to external stimuli are other prerequisites for their successful operation. Mechanically interlocked molecules such as rotaxanes and catenanes, and their precursors, that is, molecular switches and supramolecular switches including pseudorotaxanes, are molecular machines or prototypes of machines capable of mechanical motion induced by chemical signals, biological inputs, light or redox processes as the external stimuli. Switching of these functional host-guest systems on surfaces becomes a fundamental requirement for artificial molecular machines to work, mimicking the molecular machines in nature, such as proteins and their assemblies operating at dynamic interfaces such as the surfaces of cell membranes. Current research endeavors in material science and technology are focused on developing either a new class of materials or materials with novel/multiple functionalities by shifting host-guest chemistry from solution phase to surfaces. In this Account, we present our most recent attempts of building monolayers of rotaxanes/pseudorotaxanes on surfaces, providing stimuli-induced macroscopic effects and further understanding on the switchable host-guest systems at interfaces. Biocompatible versions of molecular machines based on synthetic macrocycles, such as cucurbiturils, pillararenes, calixarenes, and cyclodextrins, have been employed to form self-assembled monolayers of gates on the surfaces of mesoporous silica nanoparticles to regulate the controlled release of cargo/drug molecules under a range of external stimuli, such as light, pH variations, competitive binding, and enzyme. Rotaxanes have also been assembled onto the surfaces of gold nanodisks and microcantilevers to realize active molecular plasmonics and synthetic molecular actuators for device fabrication and function. Pillararenes have been successfully used to control and aid the synthesis of gold nanoparticles, semiconducting quantum dots, and magnetic nanoparticles. The resulting organic-inorganic hydrid nanomaterials have been successfully used for controlled self-assembly, herbicide sensing and detection, pesticide removal, and so forth, taking advantage of the selective binding of pillarenes toward target molecules. Cyclodextrins have also been successfully functionalized onto the surface of gold nanoparticles to serve as recycling extractors for C60. Many interesting prototypes of nanodevices based on synthetic macrocycles and their host-guest chemistry have been constructed and served for different potential applications. This Account will be a summary of the efforts made mainly by us, and others, on the host-guest chemistry of synthetic macrocyclic compounds on the surfaces of different solid supports.
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Emodin up-regulates glucose metabolism, decreases lipolysis, and attenuates inflammation in vitro.
J Diabetes
PUBLISHED: 03-13-2014
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Emodin, the major bioactive component of Rheum palmatum, has many different activities, including antitumor, anti-inflammatory, and antidiabetes effects. Recently, emodin was reported to regulate energy metabolism. In the present study, we further explored the effects of emodin on glucose and lipid metabolism.
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Evaluation of the separation performance of polyvinylpyrrolidone as a virtual stationary phase for chromatographic NMR.
Magn Reson Chem
PUBLISHED: 03-06-2014
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Polyvinylpyrrolidone (PVP) was used as a virtual stationary phase to separate p-xylene, benzyl alcohol, and p-methylphenol by the chromatographic NMR technique. The effects of concentration and weight-average molecular weight (Mw) of PVP, solvent viscosity, solvent polarity, and sample temperature on the resolution of these components were investigated. It was found that both higher PVP concentration and higher PVP Mw caused the increase of diffusion resolution for the three components. Moreover, the diffusion resolution did not change at viscosity-higher solvents. Moreover, the three components showed different resolution at different solvents. As temperature increased, the diffusion resolution between p-xylene and benzyl alcohol gradually increased, and the one between p-xylene and p-methylphenol slightly increased from 278 to 298?K and then decreased above 298?K. It was also found that the polarity of the analytes played an important role for the separation by affecting the diffusion coefficient.
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Acetylcholine-triggered cargo release from supramolecular nanovalves based on different macrocyclic receptors.
Chemistry
PUBLISHED: 03-04-2014
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Acetylcholine (ACh), a neurotransmitter located in cholinergic synapses, can trigger cargo release from mesoporous silica nanoparticles equipped with calixarene- or pillarene-based nanovalves by removing macrocycles from the stalk components. The amount and speed of cargo release can be controlled by varying the concentration of ACh in solution or changing the type of gating macrocycle. Although this proof-of-concept study is far from a real-life application, it provides a possible route to treat diseases related to the central nervous system.
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Probing single-tumor cell interactions with different-age type I collagen networks by synchrotron-based Fourier transform infrared microspectroscopy.
J Biomed Opt
PUBLISHED: 02-28-2014
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We report here on a first study using synchrotron radiation-based Fourier transform infrared microspectroscopy and imaging to investigate HT1080 human fibrosarcoma cells grown onto different-aged type I collagen networks. Spectral images were analyzed with k-means and fuzzy C-means (FCM) clustering algorithms. K-means delineated tumor cells from their surrounding collagen networks and the latter as a function of age mainly due to specific changes in the sugar absorption region. The FCM analysis gave a better nuance of the spectral images. A progression of the biochemical information was observed upon going from the cellular compartments to the pericellular contact regions and to the intact collagens of the different age groups. Two spectral markers based on sugar and protein bands via the intensity ratio (I1032/I1655) and band area ratio (Asugar/Aamide II), showed an increase in advanced glycation endproducts (AGEs) with age. A clear-separation of the three age groups was obtained for spectra originating from the peripheral contact areas mainly due to changes in protein band intensities. The above-described markers decreased to constant levels for the three conditions indicating a masking of the biochemical information. These results hold promises to better understand the impact of age on tumor progression processes while highlighting new markers of the tumor cell invasion front.
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Efficient inhibition of human papillomavirus 16 L1 pentamer formation by a carboxylatopillarene and a p-sulfonatocalixarene.
Chem. Commun. (Camb.)
PUBLISHED: 02-13-2014
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Pillarenes and calixarenes showed obvious inhibition of HPV16 L1 pentamer formation via their selective binding to Arg and Lys residues at the monomer interface, which was reversible after the release of cyclic arenes. Pillarenes are more effective than calixarenes in terms of the inhibition efficiency, attributing to the different kinetics and binding affinity.
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Evaluation of a Hybrid Approach Using UBLAST and BLASTX for Metagenomic Sequences Annotation of Specific Functional Genes.
PLoS ONE
PUBLISHED: 01-01-2014
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The fast development of next generation sequencing (NGS) has dramatically increased the application of metagenomics in various aspects. Functional annotation is a major step in the metagenomics studies. Fast annotation of functional genes has been a challenge because of the deluge of NGS data and expanding databases. A hybrid annotation pipeline proposed previously for taxonomic assignments was evaluated in this study for metagenomic sequences annotation of specific functional genes, such as antibiotic resistance genes, arsenic resistance genes and key genes in nitrogen metabolism. The hybrid approach using UBLAST and BLASTX is 44-177 times faster than direct BLASTX in the annotation using the small protein database for the specific functional genes, with the cost of missing a small portion (<1.8%) of target sequences compared with direct BLASTX hits. Different from direct BLASTX, the time required for specific functional genes annotation using the hybrid annotation pipeline depends on the abundance for the target genes. Thus this hybrid annotation pipeline is more suitable in specific functional genes annotation than in comprehensive functional genes annotation.
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Genetic association between the HIF-1? P582S polymorphism and cervical cancer risk: a meta analysis.
Int J Clin Exp Pathol
PUBLISHED: 01-01-2014
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Hypoxia-inducible factor-1 alpha (HIF-1?) P582S polymorphism has been reported to increase transactivation capacity of HIF-1?, which is prone to tumorigenesis. Several published case-control studies on the association between P582S polymorphism and cervical cancer have shown mixed results. In this study, we chose to perform a meta-analysis to assess the association.
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Enhancing therapeutic effects of docetaxel-loaded dendritic copolymer nanoparticles by co-treatment with autophagy inhibitor on breast cancer.
Theranostics
PUBLISHED: 01-01-2014
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Dendrimers are synthetic nanocarriers that comprise a highly branched spherical polymer as new, efficient tools for drug delivery. However, the fate of nanocarriers after being internalized into cells has seldom been studied. Docetaxel loaded dendritic copolymer H40-poly(D,L-lactide) nanoparticles, referred to as "DTX-H40-PLA NPs", were prepared and used as a model to evaluate whether the NPs were sequestered by autophagy and fused with lysosomes. Besides being degraded through the endolysosomal pathway, the DTX-loaded H40-PLA NPs were also sequestered by autophagosomes and degraded through the autolysosomal pathway. DTX-loaded H40-PLA NPs may stop exerting beneficial effects after inducing autophagy of human MCF-7 cancer cells. Co-delivery of autophagy inhibitor such as chloroquine and chemotherapeutic drug DTX by dendritic copolymer NPs greatly enhanced cancer cell killing in vitro, and decreased both the volume and weight of the tumors in severe combined immunodeficient mice. These findings provide valuable evidence for development of nanomedicine such as dendritic copolymer NPs for clinical application.
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The CXCL12 G801A polymorphism is associated with cancer risk: a meta-analysis.
PLoS ONE
PUBLISHED: 01-01-2014
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CXCL12 is a small chemotactic cytokine belonging to the CXC chemokine family expressed in various organs. It contributes to the migration, invasion and angiogenesis of cancer cells. Recently, the CXCL12 G801A polymorphism was shown to be associated with an increased risk of various kinds of cancers, but the results were too inconsistent to be conclusive.
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High-Dose Interferon-? Promotes Abortion in Mice by Suppressing Treg and Th17 Polarization.
J. Interferon Cytokine Res.
PUBLISHED: 12-20-2013
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As a classic type I cytokine, interferon-gamma (IFN-?) is known to manifest a miscarriage-inducing effect, although the specific mechanism is still unclear. To determine whether immune cells such as regulatory T (Treg) and Th17 cells are involved in these abortions, syngeneically pregnant (BALB/c×BALB/c) mice were subjected to intravaginal IFN-? administration (5×10(3) IU/mouse on D3 of gestation). These mice experienced significant fetal loss on D7/D8 of pregnancy, and a remarkable drop in the Treg cell ratio was observed in the peripheral blood and the spleen by flow cytometry. In situ detection of the uterine tissue peri-implantation revealed that IFN-? treatment also caused statistically significant reductions in forkhead box P3, RAR-related orphan receptor gamma, and IL-17 levels, which indicated local decreases in Treg and Th17 cells at uterine implantation sites. The IFN-? receptor alpha (IFN-?R?) level was also lowered in the uterus. These results demonstrate that in murine pregnancy, a supraphysiological dose of IFN-? could induce peri-implantation failure. Moreover, in this study, the decreases in both Treg and Th17-type cells, which may be relevant to the role of IFN-?R?, may be one of the main reasons that IFN-? causes abortion.
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[Relationship between radial augmentation index and other indices for evaluating arteriosclerosis].
Beijing Da Xue Xue Bao
PUBLISHED: 12-18-2013
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To investigate the relationship between radial augmentation index (AI) and other noninvasive indices for evaluating arteriosclerosis.
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Change of Nrf2 expression in rat hippocampus in a model of chronic cerebral hypoperfusion.
Int. J. Neurosci.
PUBLISHED: 12-04-2013
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Chronic cerebral hypoperfusion (CCH) is common in vascular dementia and Alzheimers disease. CCH-related oxidative damage plays a significant role in the development of cognitive impairment. Nuclear factor-erythroid 2-related factor-2 (Nrf2) mediates activation of the antioxidant responsive element (ARE)-related gene expression, which is crucial to the endogenous antioxidative system. In this case, we used permanent bilateral occlusion of common carotid arteries (2VO) to mimic CCH. The expression of Nrf2 in different regions of the hippocampus as well as the ability of nuclear Nrf2 and ARE binding have been examined. A phenomenon has been observed that the DNA binding activities were down-regulated. Interestingly, the expression of Nrf2 rose significantly in most regions of rat hippocampus within three weeks after the 2VO surgery. The mismatch might attribute to Nrf2 dysfunction and compensatory synthesis. A conclusion can be drawn that Nrf2 dysfunction is an important factor as a cause of CCH-induced oxidative damage and Nrf2 can be treated as a promising target to alleviate oxidative damage, even cognitive impairment caused by CCH.
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Relative unidirectional translation in an artificial molecular assembly fueled by light.
J. Am. Chem. Soc.
PUBLISHED: 11-27-2013
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Motor molecules present in nature convert energy inputs, such as a chemical fuel or incident photons of light, into directed motion and force biochemical systems away from thermal equilibrium. The ability not only to control relative movements of components in molecules but also to drive their components preferentially in one direction relative to each other using versatile stimuli is one of the keys to future technological applications. Herein, we describe a wholly synthetic small-molecule system that, under the influence of chemical reagents, electrical potential, or visible light, undergoes unidirectional relative translational motion. Altering the redox state of a cyclobis(paraquat-p-phenylene) ring simultaneously (i) inverts the relative heights of kinetic barriers presented by the two termini-one a neutral 2-isopropylphenyl group and the other a positively charged 3,5-dimethylpyridinium unit-of a constitutionally asymmetric dumbbell, which can impair the threading/dethreading of a [2]pseudorotaxane, and (ii) controls the rings affinity for a 1,5-dioxynaphthalene binding site located in the dumbbells central core. The formation and subsequent dissociation of the [2]pseudorotaxane by passage of the ring over the neutral and positively charged termini of the dumbbell component in one, and only one, direction relatively defined has been demonstrated by (i) spectroscopic ((1)H NMR and UV/vis) means and cyclic voltammetry as well as with (ii) DFT calculations and by (iii) comparison with control compounds in the shape of constitutionally symmetrical [2]pseudorotaxanes, one with two positively charged ends and the other with two neutral ends. The operation of the system relies solely on reversible, yet stable, noncovalent bonding interactions. Moreover, in the presence of a photosensitizer, visible-light energy is the only fuel source that is needed to drive the unidirectional molecular translation, making it feasible to repeat the operation numerous times without the buildup of byproducts.
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[Clinical significance and diagnostic value of Golgi-protein 73 in patients with early-stage primary hepatocellular carcinoma].
Zhonghua Zhong Liu Za Zhi
PUBLISHED: 11-22-2013
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To explore the clinical significance and diagnostic value of GP73 in early-stage primary hepatocelluar carcinoma (PHC).
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Redox-active quinones induces genome-wide DNA methylation changes by an iron-mediated and Tet-dependent mechanism.
Nucleic Acids Res.
PUBLISHED: 11-08-2013
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DNA methylation has been proven to be a critical epigenetic mark important for various cellular processes. Here, we report that redox-active quinones, a ubiquitous class of chemicals found in natural products, cancer therapeutics and environment, stimulate the conversion of 5mC to 5hmC in vivo, and increase 5hmC in 5751 genes in cells. 5hmC increase is associated with significantly altered gene expression of 3414 genes. Interestingly, in quinone-treated cells, labile iron-sensitive protein ferritin light chain showed a significant increase at both mRNA and protein levels indicating a role of iron regulation in stimulating Tet-mediated 5mC oxidation. Consistently, the deprivation of cellular labile iron using specific chelator blocked the 5hmC increase, and a delivery of labile iron increased the 5hmC level. Moreover, both Tet1/Tet2 knockout and dimethyloxalylglycine-induced Tet inhibition diminished the 5hmC increase. These results suggest an iron-regulated Tet-dependent DNA demethylation mechanism mediated by redox-active biomolecules.
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Metagenomic profiles of antibiotic resistance genes (ARGs) between human impacted estuary and deep ocean sediments.
Environ. Sci. Technol.
PUBLISHED: 11-04-2013
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Knowledge of the origins and dissemination of antibiotic resistance genes (ARGs) is essential for understanding modern resistomes in the environment. The mechanisms of the dissemination of ARGs can be revealed through comparative studies on the metagenomic profiling of ARGs between relatively pristine and human-impacted environments. The deep ocean bed of the South China Sea (SCS) is considered to be largely devoid of anthropogenic impacts, while the Pearl River Estuary (PRE) in south China has been highly impacted by intensive human activities. Commonly used antibiotics (sulfamethazine, norfloxacin, ofloxacin, tetracycline, and erythromycin) have been detected through chemical analysis in the PRE sediments, but not in the SCS sediments. In the relatively pristine SCS sediments, the most prevalent and abundant ARGs are those related to resistance to macrolides and polypeptides, with efflux pumps as the predominant mechanism. In the contaminated PRE sediments, the typical ARG profiles suggest a prevailing resistance to antibiotics commonly used in human health and animal farming (including sulfonamides, fluoroquinolones, and aminoglycosides), and higher diversity in both genotype and resistance mechanism than those in the SCS. In particular, antibiotic inactivation significantly contributed to the resistance to aminoglycosides, ?-lactams, and macrolides observed in the PRE sediments. There was a significant correlation in the levels of abundance of ARGs and those of mobile genetic elements (including integrons and plasmids), which serve as carriers in the dissemination of ARGs in the aquatic environment. The metagenomic results from the current study support the view that ARGs naturally originate in pristine environments, while human activities accelerate the dissemination of ARGs so that microbes would be able to tolerate selective environmental stress in response to anthropogenic impacts.
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Construction of hetero[n]rotaxanes by use of polyfunctional rotaxane frameworks.
J. Org. Chem.
PUBLISHED: 10-28-2013
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Heterorotaxanes, one class of topological organic structures, have attracted increasing interesting during the past two decades. In general, two types of heterorotaxane structures exist, one in which two or more different macrocycles are threaded onto one dumbbell-shaped molecule and the other where one macrocycle is threaded onto two or more different dumbbell-shaped molecules. In comparison to these traditional types, another family of topologically interesting heterorotaxanes can be envisaged as arising from polyfunctional molecules that possess both host (crown ether) and guest (ammonium templates). In the present investigation, we have explored the construction of selected members of this new heterorotaxane family, which possess crown ether moieties that are wrapped around a dumbbell-shaped molecule. These structures are prepared by routes in which "stitching" processes, involving template-directed clipping reaction or olefin metathesis reactions, are used to install crown ether ring systems encircling ammonium cation centers. This is then followed by implementation of a threading-followed-by-stoppering sequence to install a second encircling crown ether ring. The results show that the polyfunctional building blocks assemble with high efficiencies. Finally, this investigation provides a foundation for future studies aimed at constructing more complicated heterorotaxane architectures, such as switchable systems, self-assembling polymers, and functional molecular machines.
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[Association of estrogen receptor ? gene polymorphisms with hypertension in postmenopausal women].
Zhonghua Yi Xue Za Zhi
PUBLISHED: 10-16-2013
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To explore the association between estrogen receptor ? (ER?) gene polymorphisms and hypertension in postmenopausal women.
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Electrospun nanofibers and multi-responsive supramolecular assemblies constructed from a pillar[5]arene-based receptor.
Chem. Commun. (Camb.)
PUBLISHED: 10-03-2013
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Multi-responsive supramolecular polymers have been constructed from pillar[5]arene-based receptors. Significantly, nanofibers, nanosized supramolecular polymers based on pillararenes, have been successfully fabricated employing an electrospinning technique for the first time.
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Elevated Th17 cells accompanied by decreased regulatory T cells and cytokine environment in infants with biliary atresia.
Pediatr. Surg. Int.
PUBLISHED: 09-25-2013
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The aim of this study was to investigate the role of Th17 and Treg cells in biliary atresia (BA) and to assess the liver cytokine environment in BA patients.
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Expression and prognostic significance of Golgiglycoprotein73 (GP73) with Epithelial-mesenchymal transition (EMT) related molecules in Hepatocellular Carcinoma (HCC).
Diagn Pathol
PUBLISHED: 09-19-2013
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Hepatocellular carcinoma (HCC) is the fifth most common cancer and the third cause of cancer-related deaths, worldwide. It is essential to develop an effective prognostic biomarker and determine the mechanisms underlying HCC invasion and metastasis.
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Enzyme-responsive supramolecular nanovalves crafted by mesoporous silica nanoparticles and choline-sulfonatocalix[4]arene [2]pseudorotaxanes for controlled cargo release.
Chem. Commun. (Camb.)
PUBLISHED: 08-29-2013
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Mesoporous silica nanoparticles (MSNs) have been surface-functionalized with choline moieties encircled by sulfonatocalix[4]arenes. Two enzyme cleavable sites are incorporated in the stalks for specific enzymes to regulate the release of loaded cargos from MSNs. These gated materials show a clear enzymatic response and proven orthogonality.
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Nitrogen-Doped Porous Graphitic Carbon as an Excellent Electrode Material for Advanced Supercapacitors.
Chemistry
PUBLISHED: 08-27-2013
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An advanced supercapacitor material based on nitrogen-doped porous graphitic carbon (NPGC) with high a surface area was synthesized by means of a simple coordination-pyrolysis combination process, in which tetraethyl orthosilicate (TEOS), nickel nitrate, and glucose were adopted as porogent, graphitic catalyst precursor, and carbon source, respectively. In addition, melamine was selected as a nitrogen source owing to its nitrogen-enriched structure and the strong interaction between the amine groups and the glucose unit. A low-temperature treatment resulted in the formation of a NPGC precursor by combination of the catalytic precursor, hydrolyzed TEOS, and the melamine-glucose unit. Following pyrolysis and removal of the catalyst and porogent, the NPGC material showed excellent electrical conductivity owing to its high crystallinity, a large Brunauer-Emmett-Teller surface area (SBET =1027?m(2) ?g(-1) ), and a high nitrogen level (7.72?wt?%). The unusual microstructure of NPGC materials could provide electrochemical energy storage. The NPGC material, without the need for any conductive additives, showed excellent capacitive behavior (293?F?g(-1) at 1?A?g(-1) ), long-term cycling stability, and high coulombic efficiency (>99.9?% over 5000?cycles) in KOH when used as an electrode. Notably, in a two-electrode symmetric supercapacitor, NPGC energy densities as high as 8.1 and 47.5?Wh?kg(-1) , at a high power density (10.5?kW?kg(-1) ), were achieved in 6?M KOH and 1?M Et4 NBF4 -PC electrolytes, respectively. Thus, the synthesized NPGC material could be a highly promising electrode material for advanced supercapacitors and other conversion devices.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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