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Find video protocols related to scientific articles indexed in Pubmed.
DNA Cleaving "Tandem-Array" Metallopeptides Activated With KHSO5: Towards the Development of Multi-Metallated Bioactive Conjugates and Compounds.
Curr Bioact Compd
PUBLISHED: 11-20-2014
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Amino terminal peptides of the general form Gly-Gly-His have been used to introduce single sites of metal binding and redox activity into a wide range of biomolecules to create bioactive compounds and conjugates capable of substrate oxidation. We report here that Gly-Gly-His-like peptides linked in a tandem fashion can also be generated leading to multi-metal binding arrays. While metal binding by the native Gly-Gly-His motif (typically to Cu(2+), Ni(2+), or Co(2+)) requires a terminal peptide amine ligand, previous work has demonstrated that an ornithine (Orn) residue can be substituted for the terminal Gly residue to allow solid-phase peptide synthesis to continue via the side chain N-?. This strategy thus frees the Orn residue N-? for metal binding and permits placement of a Gly-Gly-His-like metal binding domain at any location within a linear, synthetic peptide chain. As we show here, this strategy also permits the assembly of tandem arrays of metal binding units in linear peptides of the form: NH2-Gly-Gly-His-[(?)-Orn-Gly-His]n-(?)-Orn-Gly-His-CONH2 (where n = 0, 1, and 2). Metal binding titrations of these tandem arrays monitored by UV-vis and ESI-MS indicated that they bind Cu(2+), Ni(2+), or Co(2+) at each available metal binding site. Further, it was found that these systems retained their ability to modify DNA oxidatively and to an extent greater than their parent M(II)•Gly-Gly-His. These findings suggest that the tandem array metallopeptides described here may function with increased efficiency as "next generation" appendages in the design of bioactive compounds and conjugates.
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A unified lead-oriented synthesis of over fifty molecular scaffolds.
Org. Biomol. Chem.
PUBLISHED: 11-20-2014
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Controlling the properties of lead molecules is critical in drug discovery, but sourcing large numbers of lead-like compounds for screening collections is a major challenge. A unified synthetic approach is described that enabled the synthesis of 52 diverse lead-like molecular scaffolds from a minimal set of 13 precursors. The divergent approach exploited a suite of robust, functional group-tolerant transformations. Crucially, after derivatisation, these scaffolds would target significant lead-like chemical space, and complement commercially-available compounds.
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A novel fluorene-based aggregation-induced emission (AIE)-active gold(i) complex with crystallization-induced emission enhancement (CIEE) and reversible mechanochromism characteristics.
Chem. Commun. (Camb.)
PUBLISHED: 11-20-2014
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A new fluorene-based AIE-active gold(i) complex was designed and synthesized. The novel luminogen exhibits a crystallization-induced emission enhancement (CIEE) effect and reversible mechanochromic behavior with fluorescence changes between green and yellow emissions.
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A high-throughput metabolomic approach to explore the regulatory effect of mangiferin on metabolic network disturbances of hyperlipidemia rats.
Mol Biosyst
PUBLISHED: 11-20-2014
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This paper was designed to study metabolomic characters of the high-fat diet (HFD)-induced hyperlipidemia and the intervention effects of Mangiferin (MG). In this study, we aimed to investigate the intervention of MG on rats with hyperlipidemia induced by HFD and explore the possible mechanisms of hyperlipidemia. Urine metabolic profiles were analyzed using ultra-performance liquid chromatography/electrospray ionization quadruple time-of-flight mass spectrometry (UPLC-ESI-QTOF-MS) coupled with the principal component analysis (PCA) and partial least squares-discriminate analysis (PLS-DA) models, Heatmap and metabolism pathway analysis. PCA was applied to study the trajectory of the urinary metabolic phenotype of hyperlipidemia rat after administration of MG. The VIP-plot of orthogonal PLS-DA was used for discovering potential biomarkers to clarify the mechanism of MG. Biochemical analyses indicate that MG can alleviate the hyperlipidemia damage. Twenty significantly changed metabolites (potential biomarkers) were found to be reasonable in explaining the action mechanism of MG. The effectiveness of MG on hyperlipidemia is proved using the established metabolomic method and the regulated metabolic pathways involve the TCA cycle, taurine and hypotaurine metabolism, glyoxylate and dicarboxylate metabolism, glycine and serine and threonine metabolism, glycerophospholipid metabolism, primary bile acid biosynthesis etc. The results indicated that MG has a favourable protective effect on HFD-induced hyperlipidemia by adjusting the metabolic disorders. It also suggests that the metabolomic technology is a powerful approach for elucidation of the action mechanisms of MG.
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Absence of the calcium binding protein, S100A1, confers pulmonary hypertension in mice associated with endothelial dysfunction and apoptosis.
Cardiovasc. Res.
PUBLISHED: 11-15-2014
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S100A1, a 10-kDa, Ca(2+) -binding protein is expressed in endothelial cells (EC) and binds eNOS. Its absence is associated with impaired production of nitric oxide (NO) and mild systemic hypertension. As endothelial dysfunction contributes to clinical and experimental pulmonary hypertension (PH), we investigated the impact of deleting S100A1 in mice, on pulmonary hemodynamics, endothelial function, NO production, associated signalling pathways and apoptosis.
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Structure Activity Relationships of ?v Integrin Antagonists for Pulmonary Fibrosis by Variation in Aryl Substituents.
ACS Med Chem Lett
PUBLISHED: 11-13-2014
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Antagonism of ?v?6 is emerging as a potential treatment of idiopathic pulmonary fibrosis based on strong target validation. Starting from an ?v?3 antagonist lead and through simple variation in the nature and position of the aryl substituent, the discovery of compounds with improved ?v?6 activity is described. The compounds also have physicochemical properties commensurate with oral bioavailability and are high quality starting points for a drug discovery program. Compounds 33S and 43E1 are pan ?v antagonists having ca. 100 nM potency against ?v?3, ?v?5, ?v?6, and ?v?8 in cell adhesion assays. Detailed structure activity relationships with these integrins are described which also reveal substituents providing partial selectivity (defined as at least a 0.7 log difference in pIC50 values between the integrins in question) for ?v?3 and ?v?5.
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Chemical control of photochromism and a multiresponsive molecular switch based on a diarylethene derivative containing naphthol.
Photochem. Photobiol. Sci.
PUBLISHED: 10-23-2014
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A photochemically inactive diarylethene derivative with a naphthol group bridging through the imidazole unit (DIN) was synthesized to characterize a multifunctional switch. Upon stimulation by radiation (UV and visible light), the target diarylethene derivative DIN was not photochemically inactive but photo-active, it could be photo-converted into a keto compound. Moreover, the photochromic reaction of DIN was observed when it was stimulated by the addition of acid or methylation. Fluorescence quenching and the bathochromic effect occurred when DIN was stimulated by the addition of copper ions and a base, respectively. Its optical properties could be regulated by various chemical stimuli. Thus, it can potentially be utilized as a multiresponsive molecular switch.
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Ligand-Exchange Assisted Formation of Au/TiO2 Schottky Contact for Visible-Light Photocatalysis.
Nano Lett.
PUBLISHED: 10-22-2014
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Plasmonic noble metal nanoparticles have emerged as a promising material in sensitizing wide-bandgap semiconductors for visible-light photocatalysis. Conventional methods in constructing such heterocatalysts suffer from either poor control over the size of the metal nanoparticles or inefficient charge transfer through the metal/semiconductor interface, which limit their photocatalytic activity. To solve this problem, in this work we construct Au/TiO2 photocatalysts by depositing presynthesized colloidal Au nanoparticles with well-controlled sizes to TiO2 nanocrystals and then removing capping ligands on the Au surface through a delicately designed ligand-exchange method, which leads to close Au/TiO2 Schottky contact after a mild annealing process. Benefiting from this unique synthesis strategy, the obtained photocatalysts show superior activity to conventionally prepared photocatalysts in dye decomposition and water-reduction hydrogen production under visible-light illumination. This study not only opens up new opportunities in designing photoactive materials with high stability and enhanced performance for solar energy conversion but also provides a potential solution for the well-recognized challenge in cleaning capping ligands from the surface of colloidal catalyst nanoparticles.
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Fluorescent probes and bioimaging: alkali metals, alkaline earth metals and pH.
Chem Soc Rev
PUBLISHED: 10-16-2014
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All living species and life forms have an absolute requirement for bio-functional metals and acid-base equilibrium chemistry owing to the critical roles they play in biological processes. Hence, a great need exists for efficient methods to detect and monitor biometals and acids. In the last few years, great attention has been paid to the development of organic molecule based fluorescent chemosensors. The availability of new synthetic fluorescent probes has made fluorescence microscopy an indispensable tool for tracing biologically important molecules and in the area of clinical diagnostics. This review highlights the recent advances that have been made in the design and bioimaging applications of fluorescent probes for alkali metals and alkaline earth metal cations, including lithium, sodium and potassium, magnesium and calcium, and for pH determination within biological systems.
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Imides modified benzopicenes: synthesis, solid structure and optoelectronic properties.
Org. Biomol. Chem.
PUBLISHED: 09-30-2014
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Imide-modified polycyclic aromatic hydrocarbons can be widely applied in the field of optoelectronic materials. In this work, we have synthesized four novel functionalized benzopicenes and characterized their solid structures and optoelectronic properties. The fluorescence of the four functionalized benzopicenes showed red shifts with increasing solvent polarity; the quantum yields are high in the solution state and moderate in the solid state. The single crystal structures show that the benzopicenes adopt a lamellar motif ?-stacking. Their good solubility and optoelectronic properties make them potential solution-processable candidates for organic devices, bioimaging and biolabeling.
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Thermal synthesis of silver nanoplates revisited: a modified photochemical process.
ACS Nano
PUBLISHED: 09-12-2014
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The well-known photochemical and thermal methods for silver nanoplate synthesis have been generally regarded as two parallel processes without strong connections. Here we report a surprising finding that both visible light and ambient O2, which are critically important in the photochemical process, also play determining roles in the thermal synthesis. By designing a series of control experiments, we reveal that the typical thermal synthesis is essentially a modified photochemical synthesis coupled with the unique redox properties of H2O2. Light irradiation and dissolved O2 are found to be essential for initiating the formation of nanoplates, but the continued growth of nanoplates is supported by the oxidative etching and subsequent reduction of Ag due to H2O2. O2 resulting from the catalytic decomposition of H2O2 etches small nanoparticles to produce Ag(+) ions, which are then reduced back to Ag(0) by anions of H2O2 to support the growth of nanoplate seeds. The involvement of H2O2 in the reaction significantly speeds up the nanoplate formation process. These findings not only greatly improve our understanding of the unique functions of H2O2 in the thermal synthesis, but also bridge the two well established synthesis processes with a unified mechanism, and significantly enhance the reproducibility of the thermal synthesis of Ag nanoplates by identifying the critical importance of ambient light and O2.
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Decoration of size-tunable CuO nanodots on TiO2 nanocrystals for noble metal-free photocatalytic H2 production.
Nanoscale
PUBLISHED: 09-02-2014
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We report a simple yet effective approach for the decoration of the TiO2 nanocrystal surface with size-tunable CuO nanodots for high-performance noble metal-free photocatalytic H2 production. Modification with polyacrylic acid enables the surface of TiO2 nanocrystals to be selectively deposited with Cu(OH)2 nanodots, which can be subsequently converted to CuO through dehydration without changing their morphologies. UV irradiation of the nanocomposite solution in the presence of a hole scavenger produces photogenerated electrons which reduce CuO to metallic Cu nanodots, making them effective co-catalysts in a role similar to Pt for promoting photocatalytic H2 production. Due to the considerably high work function of Cu, the formation of a metal-semiconductor Schottky junction induces efficient charge separation and transfer. As a result, the TiO2 nanocrystals decorated with an optimal amount of CuO nanodots (1.7 wt%) could reach ?50% of the photocatalytic activity achievable by the Pt-TiO2 counterparts (1 wt%), clearly demonstrating the great potential of such composite catalysts for efficient noble metal-free photocatalytic H2 production.
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Uracil-DNA glycosylase (UNG) rs246079 G/A polymorphism is associated with decreased risk of esophageal cancer in a Chinese population.
Med. Oncol.
PUBLISHED: 08-31-2014
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Esophageal cancer is the sixth leading cause of cancer-associated death worldwide. In addition to environmental risk factors, genetic factors might play an important role in esophageal cancer carcinogenesis. We conducted a hospital-based case-control study to evaluate the association between functional single nucleotide polymorphisms (SNPs) in uracil-DNA glycosylase (UNG) and the development of esophageal cancer. A total of 380 esophageal squamous cell carcinoma (ESCC) cases and 380 controls were recruited for this study. The UNG rs3219218 A/G and UNG rs246079 G/A genotypes were determined using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). When the UNG rs246079 GG homozygote genotype was used as the reference group, the GA genotype was associated with a significantly decreased risk for ESCC (GA vs. GG: adjusted OR 0.67, 95 % CI 0.49-0.91, P = 0.011); the AA genotype was not associated with the risk of ESCC. In stratification analyses, a significantly decreased risk of ESCC associated with the UNG rs246079 G/A polymorphism was evident among women, younger patients and never-smokers and never-drinkers. The UNG rs3219218 A/G polymorphism was not associated with the risk for ESCC. These findings indicated that UNG rs246079 G/A might contribute to a decreased risk of ESCC in specific populations. Because of the limited sample size, further studies including a larger and more diverse population, as well as tissue-specific biological characterization, are required to confirm the current findings.
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Methyl-CpG binding domain 4 tagging polymorphisms and esophageal cancer risk in a Chinese population.
Eur. J. Cancer Prev.
PUBLISHED: 08-26-2014
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In 2009, esophageal cancer was recorded as the fifth most commonly diagnosed cancer and the fourth leading cause of cancer-related death in China. Esophageal squamous cell carcinoma (ESCC) accounts for more than 90% of esophageal cancers. Genetic factors might play an important role in the carcinogenesis of ESCC. We conducted a hospital-based case-control study to evaluate the association between methyl-CpG binding domain 4 (MBD4) rs3138373 A>G, rs2005618 T>C, and rs3138355 G>A tag single nucleotide polymorphisms and the risk of developing ESCC. A total of 629 ESCC patients and 686 controls were recruited. Genotypes were determined using the ligation detection reaction method. When the MBD4 rs3138355 GG homozygous genotype was used as the reference group, the GA, AA, and GA/AA genotypes were not associated with ESCC risk. In the recessive model, when the MBD4 rs3138355 GG/GA genotypes were used as the reference group, the AA homozygous genotype was associated with a 28% decreased risk for ESCC (AA vs.
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[Effects of metformin therapy on serum CA125 levels and its related factors in type 2 diabetics].
Zhonghua Yi Xue Za Zhi
PUBLISHED: 08-22-2014
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To explore the effects of metformin therapy on serum carbohydrate antigen 125 (CA125) levels and its related factors in type 2 diabetics with normal liver and kidney function.
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Magnetochromatic Thin-Film Microplates.
Adv. Mater. Weinheim
PUBLISHED: 08-21-2014
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A new type of magnetochromatic material is developed based on thin-film interference of microplates self-assembled from super-paramagnetic nanocrystals. Dynamic optical tuning can be achieved through orientational manipulation of free-standing super-paramagnetic thin-film microplates using external magnetic fields.
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The multifunctional sorting protein PACS-2 regulates SIRT1-mediated deacetylation of p53 to modulate p21-dependent cell-cycle arrest.
Cell Rep
PUBLISHED: 08-21-2014
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SIRT1 regulates the DNA damage response by deacetylating p53, thereby repressing p53 transcriptional output. Here, we demonstrate that the sorting protein PACS-2 regulates SIRT1-mediated deacetylation of p53 to modulate the DNA damage response. PACS-2 knockdown cells failed to efficiently undergo p53-induced cell-cycle arrest in response to DNA damage. Accordingly, p53 acetylation was reduced both in PACS-2 knockdown cells and thymocytes from Pacs-2(-/-) mice, thereby blunting induction of the cyclin-dependent kinase inhibitor p21 (CDKN1A). The SIRT1 inhibitor EX-527 or SIRT1 knockdown restored p53 acetylation and p21 induction as well as p21-dependent cell-cycle arrest in PACS-2 knockdown cells. Trafficking studies revealed that cytoplasmic PACS-2 shuttled to the nucleus, where it interacted with SIRT1 and repressed SIRT1-mediated p53 deacetylation. Correspondingly, in vitro assays demonstrated that PACS-2 directly inhibited SIRT1-catalyzed p53 deacetylation. Together, these findings identify PACS-2 as an in vivo mediator of the SIRT1-p53-p21 axis that modulates the DNA damage response.
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Total synthesis and biological studies of cryptocin and derivatives of equisetin and fusarisetin A.
Org. Biomol. Chem.
PUBLISHED: 08-21-2014
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Total synthesis of cryptocin, a fungus metabolite, was achieved based on the biosynthetic hypothesis. A variety of derivatives of cryptocin, equisetin and fusarisetin A were prepared, wherein the racemization of C-3 and diastereoselectivity of C-5 were investigated. We further examined their inhibitory effects on breast cancer cell survival and metastasis, and summarized the structure-activity relationship.
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The cytotoxic activities of cardiac glycosides from Streptocaulon juventas and the structure-activity relationships.
Fitoterapia
PUBLISHED: 08-13-2014
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A series of cardiac glycosides were isolated and identified from the anti-tumor fraction of the root of Streptocaulon juventas in previous studies. In the present research, the cytotoxic activities of the 43 cardiac glycosides on three cell lines, human lung A549 adenocarcinoma cell, large cell lung cancer NCI-H460 cell and normal human fetal lung fibroblast MRC-5 cell, were evaluated in vitro. Most of the tested compounds showed potent inhibitory activities toward the three cell lines. Then, the structure-activity relationships were discussed in detail. It was indicated that hydroxyl and acetyl groups at C-16 increased the activity, whereas hydroxyl group at C-1 and C-5 can both increase and decrease the activity. Two glucosyl groups which were connected by C1'?C6' showed better inhibitory activity against cancer cell lines, while the C1'?C4' connection showed stronger inhibitory activity against the normal cell line. Also, this is the first report that the activities of these compounds exhibited different variation trends between A549 and NCI-H460 cell lines, which indicated that these compounds could selectively inhibit the cell growth. The results would lay a foundation for further research on new anti-tumor drug development.
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Partial nitrification in sequencing batch reactors treating low ammonia strength synthetic wastewater.
Water Environ. Res.
PUBLISHED: 08-13-2014
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Sequencing batch reactors fed with low ammonium strength synthetic wastewater under C/N ratios of 0.5, 1.5, and 3.0 were used to investigate the transition from full to partial nitrification. Two strategies for establishing partial nitrification, aeration duration control and process parameter control, were compared. The effect of C/N ratio on nitrite accumulation was also evaluated. Results showed that partial nitrification established by controlling aeration duration presented better performance with higher nitrite accumulation. An increase of C/N ratio helped nitrite accumulation; however, non-filamentous bulking of sludge happened at high C/N ratio. Based on mass balances for nitrogen, results for nitrogen during full and partial nitrification were distinct from one another. For low C/N ratio, during full nitrification, almost 100% of NH(4+)-N was oxidized to NO(3-)-N without nitrogen loss; however, nitrogen loss increased obviously during partial nitrification, which indicated that dissolved oxygen concentration and C/N ratio influenced nitrogen loss significantly during nitrification.
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Revision of the Oriental genus Horniella Raffray (Coleoptera, Staphylinidae, Pselaphinae).
Zootaxa
PUBLISHED: 08-12-2014
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The Oriental pselaphine genus Horniella Raffray, 1905 (tribe Tyrini: subtribe Somatipionina) is redefined and revised. Twenty-five new species are described: H. centralis Yin & Li, sp. n., H. confragosa Yin & Li, sp. n., H. dao Yin & Li, sp. n., H. hongkongensis Yin & Li, sp. n., H. nakhi Yin & Li, sp. n., H. schuelkei Yin & Li, sp. n., H. sichuanica Yin & Li, sp. n., H. simplaria Yin & Li, sp. n., and H. tianmuensis Yin & Li, sp. n. from China, H. himalayica Yin & Li, sp. n. from Nepal and North India, H. asymmetrica Yin & Li, sp. n., H. burckhardti Yin & Li, sp. n., H. intricata Yin & Li, sp. n., H. kaengkrachan Yin & Li, sp. n., H. khaosabap Yin & Li, sp. n., H. loebli Yin & Li, sp. n., H. phuphaman Yin & Li, sp. n., H. prolixo Yin & Li, sp. n., and H. schwendingeri Yin & Li, sp. n. from Thailand, H. philippina Yin & Li, sp. n. from the Philippines, H. awana Yin & Li, sp. n., H. gigas Yin & Li, sp. n., H. pilosa Yin & Li, sp. n., and H. smetanai Yin & Li, sp. n. from Malaysia, and H. cibodas Yin & Li, sp. n. from Indonesia. The two previously described species, H. hirtella Raffray, 1901 (type species) from Sri Lanka and H. falcis Yin & Li, 2010 from China are redescribed, and a lectotype is designated for H. hirtella. Illustrations of habitus and important diagnostic features, an identification key, and distributional maps for all species are provided. Eleven unidentified species represented only by females are left unnamed. Illustrations of the habitus and the genital complex, and label data of these species are given to facilitate future study. All available data indicates that species of Horniella typically inhabit leaf litter of various kinds of forests, and can be most efficiently collected by sifting and use of Winkler-Moczarski extractors. 
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A novel fluorene-based gold(I) complex with aggregate fluorescence change: a single-component white light-emitting luminophor.
Chem. Commun. (Camb.)
PUBLISHED: 08-07-2014
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A new fluorene-based white light-emitting gold(I) complex with aggregate fluorescence change is reported. The novel luminogen emits direct white light in the solid state without involving complex doping/mixing procedures.
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Genetic variation in the tissue factor gene is associated with clinical outcome in severe sepsis patients.
Crit Care
PUBLISHED: 08-03-2014
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IntroductionActivation of inflammation and coagulation was closely related and mutually interdependent in sepsis. Tissue factor (TF) and its endogenous inhibitor, tissue factor pathway inhibitor (TFPI) was the main regulators of the initiation of coagulation process. Altered plasma levels of TF and TFPI have been related to worse outcome in sepsis. The objective of this study was to investigate whether single nucleotide polymorphisms (SNPs) in the TF and TFPI genes were associated with risk and outcome for patients with severe sepsis.MethodsSeventeen SNPs in TF and TFPI were genotyped in samples of sepsis (n =577) and severe sepsis patients (n =476), and tested for association in this case¿control collection. We then investigated correlation between the associated SNPs and the mRNA expression, and protein level of the corresponding gene. The mRNA levels of TF were determined using real-time quantitative reverse transcription-polymerase chain reaction and the soluble plasma levels of TF were measured using enzyme linked immunosorbent assay (ELISA) method.ResultsAssociation analysis revealed that three TF SNPs in perfect linkage disequilibrium, rs1361600, rs3917615 and rs958587, were significantly associated with outcome of severe sepsis. G allele frequency of rs1361600 in survivor patients was significantly higher than that in nonsurvivor severe sepsis patients (P =4.91¿×¿10¿5, odds ratio (OR) =0.48, 95% confidence interval (CI) 0.33 to 0.69). The association remained significant after adjustment for covariates in multiple logistic regression analysis and for multiple comparisons. Lipopolysaccharide-induced TF-mRNA expression levels in peripheral blood mononuclear cells from subjects carrying rs1361600 AG and GG genotypes, were significantly lower than those subjects carrying AA genotype (P =0.0012). Moreover, severe sepsis patients of GG and GA genotypes showed lower serum levels of TF than patients with AA genotype (P adj =0.02). The plasma levels of TF were also associated with outcome of severe sepsis patients (P adj =0.01). However, genotype and allele analyses did not show any significant difference between sepsis and severe sepsis patients.ConclusionsOur findings indicate that common genetic variation in TF was significantly associated with outcome of severe sepsis in Chinese Han population.
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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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[Prevention and management of complications after laparoscopic gastric bypass operation].
Zhonghua Wei Chang Wai Ke Za Zhi
PUBLISHED: 07-30-2014
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To investigate the prevention and management of complications after laparoscopic gastric bypass (LRYGB) operation.
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Construction of polyelectrolyte-responsive microgels, and polyelectrolyte concentration and chain length-dependent adsorption kinetics.
Langmuir
PUBLISHED: 07-29-2014
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We report on the construction of a polyelectrolyte-responsive system evolved from sterically stabilized protonated poly(2-vinylpyridine) (P2VPH(+)) microgels. Negatively charged sodium dodecylbenzenesulfonate (SDBS) surfactants could be readily internalized into the cationic microgels by means of electrostatic interactions, resulting in microgel collapse and concomitant formation of surfactant micellar domains (P2VPH(+)/SDBS)-contained electrostatic complexes. These internal hydrophobic domains conferred the opportunity of fluorescent dyes to be loaded. The obtained fluorescent microgel complexes could be further disintegrated in the presence of anionic polyelectrolyte, poly(sodium 4-styrenesulfonate) (PNaStS). The stronger electrostatic attraction between multivalent P2VPH(+) microgels and PNaStS polyelectrolyte than single-charged surfactant led to triggered release of the encapsulated pyrene dyes from the hydrophobic interiors into microgel dispersion. The process was confirmed by laser light scattering (LLS) and fluorescence measurements. Furthermore, the entire dynamic process of PNaStS adsorption into P2VPH(+) microgel interior was further studied by stopped-flow equipment as a function of polyelectrolyte concentration and degree of polymerization. The whole adsorption process could be well fitted with a double-exponential function, suggesting a fast (?1) and a slow (?2) relaxation time, respectively. The fast process (?1) was correlated well with the approaching of PNaStS with P2VPH(+) microgel to form a nonequilibrium complex within the microgel shell, while the slow process (?2) was consistent with the formation of equilibrium complexes in the microgel deeper inside. This simple yet feasible design augurs well for the promising applications in controlled release fields.
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Establishing evidence-based criteria for directly observed hand hygiene compliance monitoring programs: a prospective, multicenter cohort study.
Infect Control Hosp Epidemiol
PUBLISHED: 07-28-2014
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Hand hygiene surveillance programs that rely on direct observations of healthcare worker activity may be limited by the Hawthorne effect. In addition, comparing compliance rates from period to period requires adequately sized samples of observations. We aimed to statistically determine whether the Hawthorne effect is stable over an observation period and statistically derive sample sizes of observations necessary to compare compliance rates.
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Fast pyrolysis product distribution of biopretreated corn stalk by methanogen.
Bioresour. Technol.
PUBLISHED: 07-27-2014
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After pretreated by methanogen for 5, 15 and 25 days, corn stalk (CS) were pyrolyzed at 250, 300, 350, 400, 450 and 500 °C by Py-GC/MS and product distribution in bio-oil was analyzed. Results indicated that methanogen pretreatment changed considerably the product distribution: the contents of sugar and phenols increased; the contents of linear carbonyls and furans decreased; the contents of linear ketones and linear acids changed slightly. Methanogen pretreatment improved significantly the pyrolysis selectivity of CS to phenols especially 4-VP. At 250 °C, the phenols content increased from 42.25% for untreated CS to 79.32% for biopretreated CS for 5 days; the 4-VP content increased from 28.6% to 60.9%. Increasing temperature was contributed to convert more lignin into 4-VP, but decreased its content in bio-oil due to more other chemicals formed. The effects of biopretreatment time on the chemicals contents were insignificant.
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Laparoscopic Roux-en-Y Gastric Bypass for Type 2 Diabetes Mellitus in Nonobese Chinese Patients.
Surg Laparosc Endosc Percutan Tech
PUBLISHED: 07-24-2014
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Although bariatric surgery performed for morbid obesity has been shown to significantly improve type 2 diabetes mellitus (T2DM), data on its effectiveness to improve T2DM in nonobese patients are scarce. The present pilot study evaluated the clinical effects of laparoscopic Roux-en-Y gastric bypass surgery (LRYGB) in Chinese T2DM patients with body mass index (BMI) ?27.5 kg/m.
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A convergent rhodium-catalysed asymmetric synthesis of tetrahydroquinolines.
Chem. Commun. (Camb.)
PUBLISHED: 07-24-2014
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Rh-catalysed conjugate additions of 2-aminophenyl boronic acid derivatives were exploited in diastereoselective and asymmetric syntheses of tetrahydroquinolines. In both cases, combinatorial variation of the substitution of the tetrahydroquinoline ring system was possible.
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Photo-responsive [2]catenanes: synthesis and properties.
Org. Biomol. Chem.
PUBLISHED: 07-22-2014
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A series of novel dithienylethene-based macrocycles containing ammonium moieties has been synthesized. They have been employed as templates to construct [2]catenanes showing their photoisomerization properties by means of a dynamic covalent chemistry approach. Their structures have been reliably confirmed by NMR, ESI-MS or MALDI-QTOF-MS, and elemental analysis, and their energy-minimized structures of open- and closed-ring isomers were investigated by the theoretical calculation. Investigation of the photochromic properties of these dithienylethene-based [2]catenanes has revealed good reversibility and excellent fatigue resistance upon irradiation with UV or visible light. Notably, formation of the [2]catenanes enhanced the photochromic properties compared with those of the corresponding macrocyclic ammonium salt, implying that the non-covalently interacting components of the [2]catenanes could affect the photoswitchable properties.
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Unconventional route to encapsulated ultrasmall gold nanoparticles for high-temperature catalysis.
ACS Nano
PUBLISHED: 07-07-2014
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Ultrasmall gold nanoparticles (us-AuNPs, <3 nm) have been recently recognized as surprisingly active and extraordinarily effective green catalysts. Their stability against sintering during reactions, however, remains a serious issue for practical applications. Encapsulating such small nanoparticles in a layer of porous silica can dramatically enhance the stability, but it has been extremely difficult to achieve using conventional sol-gel coating methods due to the weak metal/oxide affinity. In this work, we address this challenge by developing an effective protocol for the synthesis of us-AuNP@SiO2 single-core/shell nanospheres. More specifically, we take an alternative route by starting with ultrasmall gold hydroxide nanoparticles, which have excellent affinity to silica, then carrying out controllable silica coating in reverse micelles, and finally converting gold hydroxide particles into well-protected us-AuNPs. With a single-core/shell configuration that prevents sintering of nearby us-AuNPs and amino group modification of the Au/SiO2 interface that provides additional coordinating interactions, the resulting us-AuNP@SiO2 nanospheres are highly stable at high temperatures and show high activity in catalytic CO oxidation reactions. A dramatic and continuous increase in the catalytic activity has been observed when the size of the us-AuNPs decreases from 2.3 to 1.5 nm, which reflects the intrinsic size effect of the Au nanoparticles on an inert support. The synthesis scheme described in this work is believed to be extendable to many other ultrasmall metal@oxide nanostructures for much broader catalytic applications.
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Theoretical investigations on charge-transfer properties of pentacenequinone derivatives as n-type organic semiconductors.
J Mol Model
PUBLISHED: 06-26-2014
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Electron mobilities of two pentacenquinone derivatives as n-type organic semiconductors, 5,7,12,14-tetraaza-6,13-pentacenquinone (TAPQ5) and 1,4,8,11-tetraaza-6,13-pentacenquinone (TAPQ7), have been investigated at the molecular and crystal levels by means of the density functional theory (DFT) calculations and the incoherent charge-hopping model. It was found that these materials have lower LUMO energy levels, which can easily function as n-type organic semiconductors. The reorganization energy and transfer integral are the two important factors for tuning the electron transfer. The small reorganization energy and the large transfer integral for electron transport suggested that they have relatively high electron mobilities. The transfer integral among the dominant hopping pathways showed that the electron transport processes occur in parallel dimers between two neighboring molecules with ?-stacking interactions. On the basis of the angular resolution anisotropic mobility investigation, TAPQ5 and TAPQ7 exhibit remarkable angular dependence of mobilities and anisotropic behaviors. The results are helpful for experimentalists to choose the candidate materials and to design novel organic semiconductors.
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Magnetically actuated liquid crystals.
Nano Lett.
PUBLISHED: 06-26-2014
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Ferrimagnetic inorganic nanorods have been used as building blocks to construct liquid crystals with optical properties that can be instantly and reversibly controlled by manipulating the nanorod orientation using considerably weak external magnetic fields (1 mT). Under an alternating magnetic field, they exhibit an optical switching frequency above 100 Hz, which is comparable to the performance of commercial liquid crystals based on electrical switching. By combining magnetic alignment and lithography processes, it is also possible to create patterns of different polarizations in a thin composite film and control over the transmittance of light in particular areas. Developing such magnetically responsive liquid crystals opens the door toward various applications, which may benefit from the instantaneous and contactless nature of magnetic manipulation.
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Improving production of volatile fatty acids from food waste fermentation by hydrothermal pretreatment.
Bioresour. Technol.
PUBLISHED: 06-21-2014
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Food waste (FW) was pretreated by a hydrothermal method and then fermented for volatile fatty acid (VFAs) production. The soluble substance in FW increased after hydrothermal pretreatment (?200 °C). Higher hydrothermal temperature would lead to mineralization of the organic compounds. The optimal temperature for organic dissolution was 180 °C, at which FW dissolved 42.5% more soluble chemical oxygen demand than the control. VFA production from pretreated FW fermentation was significantly enhanced compared with the control. The optimal hydrothermal temperature was 160 °C with a VFA yield of 0.908 g/g VSremoval. Butyrate and acetate were the prevalent VFAs followed by propionate and valerate. FW fermentation was inhibited after 200 °C pretreatment. The VFAs were extracted from the fermentation broth by liquid-liquid extraction. The VFA recovery was 50-70%. Thus, 0.294-0.411 g VFAs could be obtained per gram of hydrothermally pretreated FW (in dry weight) by this method.
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New species and new record of Megatyrus Hlavá? & Nomura (Coleoptera: Staphylinidae: Pselaphinae) from Asia.
Zootaxa
PUBLISHED: 06-13-2014
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A new species, Megatyrus femoralis sp. n., is described from the Koshi Zone, East Nepal, with major diagnostic features illustrated. Megatyrus masumotoi Nomura, Sakchoowong & Chanpaisaeng, originally described from southwestern Thailand, is recorded from the Noring Timur Mountain, West Malaysia. The above data extends the known range of Megatyrus about 1,200 km to the west, and 870 km to the south.
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A new species of Syndicus (s. str.) Motschulsky (Coleoptera, Staphylinidae, Scydmaeninae) from East China.
Zootaxa
PUBLISHED: 06-06-2014
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Syndicus (s. str.) jaloszynskii Yin and Song, new species is described from Fujian and Zhejiang, East China. All material was collected in rotten woods. The habitus of both sexes, aedeagus, and spermatheca are illustrated. The new species can be readily separated from all known congeners by the strikingly large body size, the structure of aedeagal endophallus, and the form of spermatheca. This is the first species of the nominotypical subgenus of Syndicus known to occur in China.
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Promotion of atomic hydrogen recombination as an alternative to electron trapping for the role of metals in the photocatalytic production of H2.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 05-19-2014
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The production of hydrogen from water with semiconductor photocatalysts can be promoted by adding small amounts of metals to their surfaces. The resulting enhancement in photocatalytic activity is commonly attributed to a fast transfer of the excited electrons generated by photon absorption from the semiconductor to the metal, a step that prevents deexcitation back to the ground electronic state. Here we provide experimental evidence that suggests an alternative pathway that does not involve electron transfer to the metal but requires it to act as a catalyst for the recombination of the hydrogen atoms made via the reduction of protons on the surface of the semiconductor instead.
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Fully alloyed Ag/Au nanospheres: combining the plasmonic property of Ag with the stability of Au.
J. Am. Chem. Soc.
PUBLISHED: 05-12-2014
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We report that fully alloyed Ag/Au nanospheres with high compositional homogeneity ensured by annealing at elevated temperatures show large extinction cross sections, extremely narrow bandwidths, and remarkable stability in harsh chemical environments. Nanostructures of Ag are known to have much stronger surface plasmon resonance than Au, but their applications in many areas have been very limited by their poor chemical stability against nonideal chemical environments. Here we address this issue by producing fully alloyed Ag/Au nanospheres through a surface-protected annealing process. A critical temperature has been found to be around 930 °C, below which the resulting alloy nanospheres, although significantly more stable than pure silver nanoparticles, can still gradually decay upon extended exposure to a harsh etchant. Nanospheres annealed above the critical temperature show a homogeneous distribution of Ag and Au, minimal crystallographic defects, and the absence of structural and compositional interfaces, which account for the extremely narrow bandwidths of the surface plasmon resonance and may enable many plasmonic applications with high performance and long lifetime, especially for those involving corrosive species.
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miR-27a suppresses EV71 replication by directly targeting EGFR.
Virus Genes
PUBLISHED: 04-30-2014
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Enterovirus 71 (EV71), a major causative agent of hand, foot, and mouth disease, has broken out several times and was accompanied by neurological disease. microRNAs, a class of small non-coding RNAs that are approximately 20 nucleotides long, play important roles in the regulation of various biological processes, including antiviral defense. However, the roles of miRNAs in EV71 replication and pathogenesis are not well understood. In this study, we found that the expression of miR-27a was significantly decreased in EV71-infected cells. Interestingly, the over-expression of miR-27a could inhibit EV71 replication, as measured by virus titration, qPCR, and Western blotting. We identified EGFR mRNA is a bona fide target of miR-27a by computational analysis and luciferase reporter assays. Furthermore, miR-27a could decrease EGFR expression, as measured by qPCR and Western blotting. Moreover, the inhibition of EGFR expression by miR-27a decreased the phosphorylation of Akt and ERK, which facilitate EV71 replication. These results suggest that miR-27a may have antiviral activity against EV71 by inhibiting EGFR.
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Ambidalmines A-E and ambidimerine F: bioactive dihydrobenzophenanthridine alkaloids from Corydalis ambigua var. amurensis.
Eur J Med Chem
PUBLISHED: 04-23-2014
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Ten new scarce dihydrobenzophenanthridine alkaloids, including seven monomers, ambidalmines A(1/2), B(1/2)-E (1(a/b), 2(a/b)-5), and three dimers, ambidimerines F1 (6a), F2 (6b) and F3 (6c), were isolated from the tubers of Corydalis ambigua var. amurensis. All of these compounds were discovered in the forms of enantiomers. The structures were elucidated based on extensive spectroscopic analysis, with absolute configurations of the enantiomeric compounds assigned by single-crystal X-ray diffraction analysis, circular dichroism (CD) and optical rotations. Bioactivity evaluation showed that compounds 1a, 2a, 2b and 6b exhibit comparable protective effects on hypoxic H9C2 cells.
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Colorimetric stress memory sensor based on disassembly of gold nanoparticle chains.
Nano Lett.
PUBLISHED: 04-08-2014
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We report the development of a stress-responsive colorimetric film that can memorize the stress it has experienced. The system is designed by taking advantage of the plasmonic shift associated with the disassembly of one-dimensional gold nanoparticle chains driven by the plastic deformation of the surrounding polymer matrix. By modifying the plasticity of the polymer, we demonstrate that the plasmonic shift and colorimetric change respond to a large range of stresses. This novel pressure indicating film can be used to capture and record the pressure distribution and magnitude between two contacting or impacting surfaces by outputting color information.
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Sigma-1 (?1) receptor deficiency reduces ?-amyloid25-35-induced hippocampal neuronal cell death and cognitive deficits through suppressing phosphorylation of the NMDA receptor NR2B.
Neuropharmacology
PUBLISHED: 04-04-2014
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In early Alzheimer's disease (AD) brain, reduction of sigma-1 receptors (?1R) is detected. In this study, we employed male heterozygous ?1R knockout (?1R±) mice showing normal cognitive performance to investigate association of ?1R deficiency with AD risk. Herein we report that a single injection (i.c.v.) of A?25-35 impaired spatial memory with approximately 25% death of pyramidal cells in the hippocampal CA1 region of WT mice (A?25-35-WT mice), whereas it did not cause such impairments in ?1R± mice (A?25-35-?1R± mice). Compared with WT mice, A?25-35-WT mice showed increased levels of NMDA-activated currents (INMDA) and NR2B phosphorylation (phospho-NR2B) in the hippocampal CA1 region at 48 h after A?25-35-injection (post-A?25-35) followed by approximately 40% decline at 72 h post-A?25-35 of their respective control levels, which was inhibited by the ?1R antagonist NE100. In A?25-35-WT mice, the administration of NR2B inhibitor Ro25-6981 or NE100 on day 1-4 post-A?25-35 attenuated the memory deficits and loss of pyramidal cells. By contrast, A?25-35-?1R± mice showed a slight increase in the INMDA density and the phospho-NR2B at 48 h or 72 h post-A?25-35 compared to ?1R± mice. Treatment with ?1R agonist PRE084 in A?25-35-?1R± mice caused the same changes in the INMDA density and the phospho-NR2B as those in A?25-35-WT mice. Furthermore, A?25-35-?1R± mice treated with the NMDA receptor agonist NMDA or PRE084 on day 1-4 post-A?25-35 showed a loss of neuronal cells and memory impairment. These results indicate that the ?1R deficiency can reduce A?25-35-induced neuronal cell death and cognitive deficits through suppressing A?25-35-enhanced NR2B phosphorylation.
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One-step growth of triangular silver nanoplates with predictable sizes on a large scale.
Nanoscale
PUBLISHED: 03-25-2014
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A one-step growth of triangular silver nanoplates on a large scale is developed by a coordination-based kinetically controlled seeded growth method, with their edge length precisely tuned from 150 nm to 1.5 ?m, and surface plasmon resonance extends to full near-infrared.
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Interaction between the thyroarytenoid and lateral cricoarytenoid muscles in the control of vocal fold adduction and eigenfrequencies.
J Biomech Eng
PUBLISHED: 03-24-2014
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Although it is known vocal fold adduction is achieved through laryngeal muscle activation, it is still unclear how interaction between individual laryngeal muscle activations affects vocal fold adduction and vocal fold stiffness, both of which are important factors determining vocal fold vibration and the resulting voice quality. In this study, a three-dimensional (3D) finite element model was developed to investigate vocal fold adduction and changes in vocal fold eigenfrequencies due to the interaction between the lateral cricoarytenoid (LCA) and thyroarytenoid (TA) muscles. The results showed that LCA contraction led to a medial and downward rocking motion of the arytenoid cartilage in the coronal plane about the long axis of the cricoid cartilage facet, which adducted the posterior portion of the glottis but had little influence on vocal fold eigenfrequencies. In contrast, TA activation caused a medial rotation of the vocal folds toward the glottal midline, resulting in adduction of the anterior portion of the glottis and significant increase in vocal fold eigenfrequencies. This vocal fold-stiffening effect of TA activation also reduced the posterior adductory effect of LCA activation. The implications of the results for phonation control are discussed.
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Jacarelhyperol A induced apoptosis in leukaemia cancer cell through inhibition the activity of Bcl-2 proteins.
BMC Cancer
PUBLISHED: 03-14-2014
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Hypericum japonicum Thunb. ex Murray is widely used as an herbal medicine for the treatment of hepatitis and tumours in China. However, the molecular mechanisms of its effects are unclear. Our previous research showed that extracts of H. japonicum can induce apoptosis in leukaemia cells. We also previously systematically analysed and isolated the chemical composition of H. japonicum.
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Monitoring the shape evolution of Pd nanocubes to octahedra by PdS frame markers.
Nanoscale
PUBLISHED: 02-28-2014
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We report the use of compounds formed on the surface of nanocrystals as markers to effectively monitor the shape evolution during nanocrystal growth. By labelling the corners and edges of cubic Pd seeds with PdS through sulfuration, we obtain clear insight into their shape transition to octahedra. This work significantly expands the scope of the marker technique for studying nanoparticle shape evolution.
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Reactive transport modeling of ??Sr sorption in reactive sandpacks.
J. Hazard. Mater.
PUBLISHED: 02-22-2014
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Strontium-90 ((90)Sr) is one of the most problematic radioactive contaminants in groundwater at nuclear sites. Although (90)Sr is retarded relative to groundwater flow, it is sufficiently mobile and long-lived to require treatment in many hydrogeological settings. A detailed study was performed on the practicality of using granular clinoptilolite as a sandpack around groundwater wells where groundwater is contaminated with (90)Sr and the water table must be lowered. The effectiveness of the reactive sandpack concept and the mechanisms controlling (90)Sr attenuation was investigated by numerical analysis of data obtained from four in situ column experiments. The experiments spanned the range of pore-water velocities that would occur during radial flow through granular clinoptilolite sandpacks. A kinetic sorption model was required to adequately reproduce the experimentally observed (90)Sr behavior. Calibrated first-order kinetic rates were correlated with pore-water velocities. After calibration, three sorption models were used to simulate (90)Sr attenuation for four hypothetical pumping scenarios. Results show that a velocity-dependent kinetic model accurately simulates the observed early breakthrough for high pore-water velocities. The results indicate (1) that reactive sandpacks have good potential for in situ remediation and construction dewatering and (2) that quantitative modeling can aid in the design and application of this novel technique.
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Nanocrystalline TiO?-catalyzed photoreversible color switching.
Nano Lett.
PUBLISHED: 02-20-2014
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We report a novel photoreversible color switching system based on the photocatalytic activity of TiO2 nanocrystals and the redox-driven color switching property of methylene blue (MB). This system rapidly changes from blue to colorless under UV irradiation and recovers its original blue color under visible light irradiation. We have identified four major competing reactions that contribute to the photoreversible switching, among which two are dominant: the decoloration process is mainly driven by the reduction of MB to leuco MB by photogenerated electrons from TiO2 nanocrystals under UV irradiation, and the recoloration process operates by the TiO2-induced self-catalyzed oxidation of LMB under visible irradiation. Compared with the conventional color switching systems based on photoisomerization of chromophores, our system has not only low toxicity but also significantly improved switching rate and cycling performance. It is envisioned that this photoreversible system may promise unique opportunities for many light-driven actuating or color switching applications.
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A new species of Lasinus Sharp (Coleoptera: Staphylinidae: Pselaphinae) from East China.
Zootaxa
PUBLISHED: 02-12-2014
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Lasinus orientalis Yin & Bekchiev, new species, is described from the eastern Chinese provinces of Zhejiang and Jiangxi, with major diagnostic features illustrated. The new species is compared with, and distinguished from related congeners.
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Genes and signaling networks regulated during zebrafish optic vesicle morphogenesis.
BMC Genomics
PUBLISHED: 02-09-2014
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The genetic cascades underpinning vertebrate early eye morphogenesis are poorly understood. One gene family essential for eye morphogenesis encodes the retinal homeobox (Rx) transcription factors. Mutations in the human retinal homeobox gene (RAX) can lead to gross morphological phenotypes ranging from microphthalmia to anophthalmia. Zebrafish rx3 null mutants produce a similar striking eyeless phenotype with an associated expanded forebrain. Thus, we used zebrafish rx3-/- mutants as a model to uncover an Rx3-regulated gene network during early eye morphogenesis.
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Description of Bryantinus gen. n. from Sarawak, and New Distributional Records for Cerochusa cilioceps in Thailand (Coleoptera: Staphylinidae: Pselaphinae).
PLoS ONE
PUBLISHED: 01-01-2014
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A new genus and species of the subtribe Batrisina from western Sarawak, Bryantinus matangus gen. et sp. n., is described, illustrated, and compared with related taxa. In addition, examination of a small series of batrisine material from Thailand revealed a new country record for Cerochusa cilioceps Yin & Nomura, which was previously known only from the island of Hainan in southern China.
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miR-107 Activates ATR/Chk1 Pathway and Suppress Cervical Cancer Invasion by Targeting MCL1.
PLoS ONE
PUBLISHED: 01-01-2014
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MicroRNAs (miRNAs) are a class of single-stranded, non-coding RNAs of about 22 nucleotides in length. Increasing evidence implicates miRNAs may function as oncogenes or tumor suppressors. Here we showed that miR-107 directly targeted MCL1 and activated ATR/Chk1 pathway to inhibit proliferation, migration and invasiveness of cervical cancer cells. Moreover, we found that MCL1 was frequently up-regulated in cervical cancer, and knockdown of MCL1 markedly inhibited cancer cell proliferation, migration and invasion, whereas ectopic expression of MCL1 significantly enhances these properties. The restoration of MCL1 expression can counteract the effect of miR-107 on the cancer cells. Together, miR-107 is a new regulator of MCL1, and both miR-107 and MCL1 play important roles in the pathogenesis of cervical cancer. We have therefore identified a mechanism for ATR/Chk1 pathway which involves an increase in miR-107 leading to a decrease in MCL1. Correspondingly, our results revealed that miR-107 affected ATR/Chk1 signalling and gene expression, and implicated miR-107 as a therapeutic target in human cervical cancer. We also demonstrated that taxol attenuated migration and invasion in cervical cancer cells by activating the miR-107, in which miR-107 play an important role in regulating the expression of MCL1. Elucidation of this discovered MCL1 was directly regulated by miR-107 will greatly enhance our understanding of the mechanisms responsible for cervical cancer and will provide an additional arm for the development of anticancer therapies.
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Finding candidate drugs for hepatitis C based on chemical-chemical and chemical-protein interactions.
PLoS ONE
PUBLISHED: 01-01-2014
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Hepatitis C virus (HCV) is an infectious virus that can cause serious illnesses. Only a few drugs have been reported to effectively treat hepatitis C. To have greater diversity in drug choice and better treatment options, it is necessary to develop more drugs to treat the infection. However, it is time-consuming and expensive to discover candidate drugs using experimental methods, and computational methods may complement experimental approaches as a preliminary filtering process. This type of approach was proposed by using known chemical-chemical interactions to extract interactive compounds with three known drug compounds of HCV, and the probabilities of these drug compounds being able to treat hepatitis C were calculated using chemical-protein interactions between the interactive compounds and HCV target genes. Moreover, the randomization test and expectation-maximization (EM) algorithm were both employed to exclude false discoveries. Analysis of the selected compounds, including acyclovir and ganciclovir, indicated that some of these compounds had potential to treat the HCV. Hopefully, this proposed method could provide new insights into the discovery of candidate drugs for the treatment of HCV and other diseases.
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Berberine promotes glucose consumption independently of AMP-activated protein kinase activation.
PLoS ONE
PUBLISHED: 01-01-2014
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Berberine is a plant alkaloid with anti-diabetic action. Activation of AMP-activated protein kinase (AMPK) pathway has been proposed as mechanism for berberine's action. This study aimed to examine whether AMPK activation was necessary for berberine's glucose-lowering effect. We found that in HepG2 hepatocytes and C2C12 myotubes, berberine significantly increased glucose consumption and lactate release in a dose-dependent manner. AMPK and acetyl coenzyme A synthetase (ACC) phosphorylation were stimulated by 20 µmol/L berberine. Nevertheless, berberine was still effective on stimulating glucose utilization and lactate production, when the AMPK activation was blocked by (1) inhibition of AMPK activity by Compound C, (2) suppression of AMPK? expression by siRNA, and (3) blockade of AMPK pathway by adenoviruses containing dominant-negative forms of AMPK?1/?2. To test the effect of berberine on oxygen consumption, extracellular flux analysis was performed in Seahorse XF24 analyzer. The activity of respiratory chain complex I was almost fully blocked in C2C12 myotubes by berberine. Metformin, as a positive control, showed similar effects as berberine. These results suggest that berberine and metformin promote glucose metabolism by stimulating glycolysis, which probably results from inhibition of mitochondrial respiratory chain complex I, independent of AMPK activation.
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A new species of Diartiger Sharp (Staphylinidae, Pselaphinae, Clavigeritae) from the Fengyangshan - Baishanzu Nature Reserve, East China.
Zookeys
PUBLISHED: 01-01-2014
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A new clavigerine pselaphine, Diartiger zhejiangensis Yin & Li, sp. n., from the Fengyangshan - Baishanzu Nature Reserve, southern Zhejiang, is described, illustrated, and compared with congeners. The species is hosted by ants in the genus Lasius. The key to Diartiger species from China is modified to accommodate the new species.
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RANK rs1805034 T>C polymorphism is associated with susceptibility of esophageal cancer in a Chinese population.
PLoS ONE
PUBLISHED: 01-01-2014
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Esophageal cancer remains the sixth leading cause of cancer associated death and eighth most common cancer worldwide. Genetic factors, such as single nucleotide polymorphisms (SNPs), may contribute to the carcinogenesis of esophageal cancer. Here, we conducted a hospital based case-control study to evaluate the genetic susceptibility of functional SNPs on the development of esophageal cancer. A total of 629 esophageal squamous cell carcinoma (ESCC) cases and 686 controls were enrolled for this study. The OPG rs3102735 T>C, rs2073618 G>C, RANK rs1805034 T>C, RANKL rs9533156 T>C and rs2277438 A>G were determined by ligation detection reaction method. Our findings suggested that RANK rs1805034 T>C is associated with the susceptibility of ESCC, which is more evident in male and elder (?63) patients. Our study provides the first evidence that functional polymorphisms RANK rs1805034 T>C may be an indicator for individual susceptibility to ESCC. However, further larger studies among different ethnic populations are warranted to verify our conclusion.
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TERT-CLPTM1L Rs401681 C>T polymorphism was associated with a decreased risk of esophageal cancer in a Chinese population.
PLoS ONE
PUBLISHED: 01-01-2014
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Esophageal cancer was the fifth most commonly diagnosed cancer and the fourth leading cause of cancer-related death in China in 2009. Esophageal squamous cell carcinoma (ESCC) accounts for more than 90 percent of esophageal cancers. Genetic factors probably play an important role in the ESCC carcinogenesis.
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NQO1 rs1800566 C>T polymorphism was associated with a decreased risk of esophageal cancer in a Chinese population.
Scand. J. Gastroenterol.
PUBLISHED: 12-19-2013
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Abstract Background. Esophageal cancer was the fifth most commonly diagnosed cancer and the fourth leading cause of cancer-related death in China in 2009. Esophageal squamous cell carcinoma (ESCC) accounts for more than 90% of esophageal cancers. Genetic factors may play an important role in the carcinogenesis of ESCC. Methods. We conducted a hospital-based case-control study to evaluate functional NAD(P)H:quinone oxidoreductase 1 (NQO1) rs1800566 C>T and NQO2 rs2070999 G>A single-nucleotide polymorphisms on the risk of ESCC. A total of 629 patients with ESCC and 686 controls were recruited for this study. The genotypes were determined using the ligation detection reaction method. Results. When the NQO1 rs1800566 CC homozygote genotype was used as the reference group, the TT genotype was associated with a significantly decreased risk of ESCC. In the recessive model, when the NQO1 rs1800566 CC/CT genotypes were used as the reference group, the TT homozygote genotype was associated with a 31% decreased risk of ESCC. A significantly decreased risk of ESCC was evident in patients with the NQO1 rs1800566 C>T polymorphism among females, those of a younger age (<63 years), those who had never smoked, those who consumed alcohol and those who did not. There was no association found between the NQO2 rs2070999 G>A polymorphism and ESCC risk. Conclusion. The NQO1 rs1800566 TT genotype was associated with a decreased risk of ESCC in a Chinese population. The association was evident among female patients, younger patients, patients who had never smoked, patients who consumed alcohol and those who did not. These findings need to be confirmed by repeating the study in a larger cohort of patients.
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Complementary and alternative medicine is expected to make greater contribution in controlling the prevalence of influenza.
Biosci Trends
PUBLISHED: 11-19-2013
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Influenza pandemics are a serious threat to public health in todays world. In the past 10 years, the outbreak of three forms of severe influenza--H5N1, H1N1, and H7N9--has caused tremendous loss of life and property. In order to better cope with pandemics, antivirals such as oseltamivir are being stockpiled in great quantities, placing a substantial burden on government budgets and potentially resulting in massive waste because of the uncertainty as to when an influenza pandemic will strike and whether emerging virus strains will be resistant to the stockpiled drugs. Complementary and alternative medicine (CAM) is generally available, affordable, and commonly used in China and many other countries and CAM has a long track record of fighting influenza. The Chinese Government appropriated funds to intensively investigate herbal medicines in accordance with the principles of evidence-based medicine in order to identify effective, inexpensive, and easily stockpiled medicines. Thus far, several drugs including Shufeng Jiedu capsules, Lianhua Qingwen capsules, Maxing Shigan decoction, Yinqiao powder, and Jinhua Qinggan granules have demonstrated effectiveness in fighting influenza. In the future, CAM is expected to make greater contribution in controlling the prevalence of influenza pandemics.
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MicroRNA-503 acts as a tumor suppressor in glioblastoma for multiple antitumor effects by targeting IGF-1R.
Oncol. Rep.
PUBLISHED: 11-13-2013
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microRNA (miRNA) dysregulation is associated with various types of human cancer by regulating cancer cell survival, proliferation and invasion. Aberrant expression of microRNA-503 (miR-503) has been reported in several cancer profiles. However, potential linkage of miR-503 levels and the underlying regulatory mechanisms in human glioblastoma multiforme (GBM) remain unclear. In the present study, we showed for the first time that the expression of miR-503 was significantly reduced in GBM tissues and cell lines (U251 and U87MG) relative to normal brain tissues. Furthermore, our results demonstrated that overexpression of miR-503 in GBM cell lines not only suppressed cell proliferation through inducing G0/G1 cell cycle arrest and apoptosis, but also inhibited cancer cell migration and tumor invasion. In addition, we identified insulin-like growth factor-1 (IGF?1R) receptor mRNA is a bona fide target of miR-503 by computational analysis followed by luciferase reporter assays. Of note, upregulation of miR-503 in GBM cells suppressed endogenous IGF-1R protein expression. Further mechanistic analysis revealed that forced expression of miR-503 inhibited AKT activation, suggesting the tumor suppressive effect of miR-503 in GBM cells is partially mediated by phosphatidylinositol 3-kinase/AKT signaling. Taken together, the results of the present study demonstrated that miR-503 is a tumor suppressor for GBM and a favorable factor against glioma progression through targeting IGF-1R, thus providing a new evidence-supported prognostic marker for GBM diagnosis.
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Photocatalytic synthesis and photovoltaic application of Ag-TiO2 nanorod composites.
Nano Lett.
PUBLISHED: 10-31-2013
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A photocatalytic strategy has been developed to synthesize colloidal Ag-TiO2 nanorod composites in which each TiO2 nanorod contains a single Ag nanoparticle on its surface. In this rational synthesis, photoexcitation of TiO2 nanorods under UV illumination produces electrons that reduce Ag(I) precursor and deposit multiple small Ag nanoparticles on the surface of TiO2 nanorods. Prolonged UV irradiation induces an interesting ripening process, which dissolves the smaller nanoparticles by photogenerated oxidative species and then redeposits Ag onto one larger and more stable particle attached to each TiO2 nanorod through the reduction of photoexcited electrons. The size of the Ag nanoparticles can be precisely controlled by varying the irradiation time and the amount of alcohol additive. The Ag-TiO2 nanorod composites were used as electron transport layers in the fabrication of organic solar cells and showed notable enhancement in power conversion efficiency (6.92%) than pure TiO2 nanorods (5.81%), as well as higher external quantum efficiency due to improved charge separation and transfer by the presence of Ag nanoparticles.
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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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Multipole plasmon resonances in self-assembled metal hollow-nanospheres.
Nanoscale
PUBLISHED: 10-25-2013
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Recently, multipole plasmonic mode resonances in metal hollow structures, such as dipole, quadrupole, and octupole modes, have been widely investigated by researchers with the aim for potential applications in bio-sensing, fluorescence, nanolasers or nonlinear nano-photonics. Here, in this work, the multipole plasmon resonances in self-assembled metal hollow-nanospheres (HNSs) are theoretically and experimentally demonstrated and the hot spots originating from the higher order mode plasmonic resonance and interparticle coupling effect are proposed to be used for Raman scattering enhancements. Dipole, quadrupole, octupole and hexadecapole mode plasmonic resonances were clearly resolved in the extinction spectra of these Ag HNS arrays showing good agreement with the theoretical simulation results. Strong regular hot spots were obtained around the surface and in the gaps of the Ag HNSs through the higher order mode plasmonic resonances and corresponding interparticle coupling effect between the HNSs. Maximum local field intensity was accomplished by optimizing the size of as well as the coupling distance between the HNSs and then it was applied to SERS sensing. Raman mapping also demonstrated these self-assembled plasmonic cavity arrays to be a stable and uniform SERS-active substrate.
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Membranes with highly ordered straight nanopores by selective swelling of fast perpendicularly aligned block copolymers.
ACS Nano
PUBLISHED: 10-18-2013
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Membranes with uniform, straight nanopores have important applications in diverse fields, but their application is limited by the lack of efficient producing methods with high controllability. In this work, we reported on an extremely simple and efficient strategy to produce such well-defined membranes. We demonstrated that neutral solvents were capable of annealing amphiphilic block copolymer (BCP) films of polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) with thicknesses up to 600 nm to the perpendicular orientation within 1 min. Annealing in neutral solvents was also effective to the perpendicular alignment of block copolymers with very high molecular weights, e.g., 362?000 Da. Remarkably, simply by immersing the annealed BCP films in hot ethanol followed by drying in air, the originally dense BCP films were nondestructively converted into porous membranes containing highly ordered, straight nanopores traversing the entire thickness of the membrane (up to 1.1 ?m). Grazing incident small-angle X-ray spectroscopy confirmed the hexagonal ordering of the nanopores over large areas. We found that the overflow of P2VP chains from their reservoir P2VP cylinders and the deformation of the PS matrix in the swelling process contributed to the transformation of the solid P2VP cylinders to empty straight pores. The pore diameters can be tuned by either changing the swelling temperatures or depositing thin layers of metal oxides on the preformed membranes via atomic layer deposition with a subnanometer accuracy. To demonstrate the application of the obtained porous membranes, we used them as templates and produced centimeter-scale arrays of aligned nanotubes of metal oxides with finely tunable wall thicknesses.
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Coxsackievirus A16 infection triggers apoptosis in RD cells by inducing ER stress.
Biochem. Biophys. Res. Commun.
PUBLISHED: 10-17-2013
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Coxsackievirus A16 (CA16) infection, which is responsible for hand, foot and mouth disease (HFMD), has become a common health problem in Asia due to the prevalence of the virus. Thus, it is important to understand the pathogenesis of CA16 infection. Viruses that induce endoplasmic reticulum (ER) stress are confronted with the unfolded protein response (UPR), which may lead to apoptotic cell death and influence viral replication. In this study, we found that CA16 infection could induce apoptosis and ER stress in RD cells. Interestingly, apoptosis via the activation of caspase-3, -8 and -9 in the extrinsic or intrinsic apoptotic pathways in RD cells was inhibited by 4-phenyl butyric acid (4PBA), a chemical chaperone that reduces ER stress. These results suggest that CA16 infection leads to ER stress, which in turn results in prolonged ER stress-induced apoptosis. This study provides a new basis for understanding CA16 infection and host responses.
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Stacked multilayers of alternating reduced graphene oxide and carbon nanotubes for planar supercapacitors.
Nanoscale
PUBLISHED: 10-11-2013
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A simple layer-by-layer approach has been developed for constructing 2D planar supercapacitors of multi-stacked reduced graphene oxide and carbon nanotubes. This sandwiched 2D architecture enables the full utilization of the maximum active surface area of rGO nanosheets by using a CNT layer as a porous physical spacer to enhance the permeation of a gel electrolyte inside the structure and reduce the agglomeration of rGO nanosheets along the vertical direction. As a result, the stacked multilayers of rGO and CNTs are capable of offering higher output voltage and current production.
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Magnetic tuning of plasmonic excitation of gold nanorods.
J. Am. Chem. Soc.
PUBLISHED: 10-08-2013
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By using gold nanorods as an example, we report the dynamic and reversible tuning of the plasmonic property of anisotropically shaped colloidal metal nanostructures by controlling their orientation using external magnetic fields. The magnetic orientational control enables instant and selective excitation of the plasmon modes of AuNRs through the manipulation of the field direction relative to the directions of incidence and polarization of light.
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Size-tailored synthesis of silver quasi-nanospheres by kinetically controlled seeded growth.
Langmuir
PUBLISHED: 08-08-2013
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This paper describes a simple and convenient procedure to synthesize monodisperse silver (Ag) quasi-nanospheres with size tunable in a range of 19-140 nm through a one-step seeded growth strategy. Acetonitrile was employed as a coordinating ligand of a Ag(I) salt in order to achieve a low concentration of elemental Ag after reduction and thus suppression of new nucleation events. Since the addition of the seeds significantly accelerates the reduction reaction of Ag(I) by ascorbic acid, the reaction kinetics was further delicately balanced by tuning the reaction temperature, which proved to be critical in producing Ag quasi-nanospheres with uniform size and shape. This synthesis is highly scalable, so that it provides a simple yet very robust process for producing Ag quasi-nanospheres for many biological, analytical, and catalytic applications which often demand samples in large quantity and widely tunable particle sizes.
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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.