232 research outputs found

    Thickness dependence of microstructures in La0.8Ca0.2MnO3 thin films

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    The thickness dependence of microstructures of La0.8Ca0.2MnO3 (LCMO)/SrTiO3 (STO) thin films was investigated by high-resolution x-ray diffraction, small angle x-ray reflection, grazing incidence x-ray diffraction, scanning electron microscopy, and atomic force microscopy. The results show that all the LCMO films are well oriented in (00l) direction perpendicular to the substrate surface. Self-organized crystalline grains with a tetragonal shape are uniformly distributed on the film surface, indicating the deposition condition being of benefit to the formation of the crystalline grains. With increasing the film thickness, the crystalline quality of the LCMO film is improved, while the surface becomes rougher. There exists a nondesigned cap layer on the upper surface of the LCMO layer for all the samples. The mechanism is discussed briefly.published_or_final_versio

    Interventions for treating depression after stroke

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    Background: Depression is an important consequence of stroke that impacts on recovery yet is often not detected or inadequately treated. This is an update of a Cochrane review first published in 2004. Objectives: To determine whether pharmaceutical, psychological, or electroconvulsive treatment (ECT) of depression in patients with stroke can improve outcome. Search strategy: We searched the trials registers of the Cochrane Stroke Group (last searched October 2007) and the Cochrane Depression Anxiety and Neurosis Group (last searched February 2008). In addition, we searched the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 1, 2008), MEDLINE (1966 to May 2006), EMBASE (1980 to May 2006), CINAHL (1982 to May 2006), PsycINFO (1967 to May 2006) and other databases. We also searched reference lists, clinical trials registers, conference proceedings and dissertation abstracts, and contacted authors, researchers and pharmaceutical companies. Selection criteria: Randomised controlled trials comparing pharmaceutical agents with placebo, or various forms of psychotherapy or ECT with standard care (or attention control), in patients with stroke, with the intention of treating depression. Data collection and analysis: Two review authors selected trials for inclusion and assessed methodological quality; three review authors extracted, cross-checked and entered data. Primary analyses were the prevalence of diagnosable depressive disorder at the end of treatment. Secondary outcomes included depression scores on standard scales, physical function, death, recurrent stroke and adverse effects. Main results: Sixteen trials (17 interventions), with 1655 participants, were included in the review. Data were available for 13 pharmaceutical agents, and four trials of psychotherapy. There were no trials of ECT. The analyses were complicated by the lack of standardised diagnostic and outcome criteria, and differing analytic methods. There was some evidence of benefit of pharmacotherapy in terms of a complete remission of depression and a reduction (improvement) in scores on depression rating scales, but there was also evidence of an associated increase in adverse events. There was no evidence of benefit of psychotherapy. Authors' conclusions: A small but significant effect of pharmacotherapy (not psychotherapy) on treating depression and reducing depressive symptoms was found, as was a significant increase in adverse events. More research is required before recommendations can be made about the routine use of such treatments

    Determinants of the Incidence of Hand, Foot and Mouth Disease in China Using Geographically Weighted Regression Models

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    Child population density and climate factors are potential determinants of the HFMD incidence in most areas in China. The strength and direction of association between these factors and the incidence of HFDM is spatially heterogeneous at the local geographic level, and child population density has a greater influence on the incidence of HFMD than the climate factors

    A 3â€Č UTR SNP in COL18A1 Is Associated with Susceptibility to HBV Related Hepatocellular Carcinoma in Chinese: Three Independent Case-Control Studies

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    BACKGROUND: Accumulated evidences indicate that single nucleotide polymorphisms (SNP) in angiogenesis and tumorigenesis related genes are associated with risk of Hepatocellular carcinoma (HCC). COL18A1 encodes the precursor of endostatin, which is a broad-spectrum angiogenesis inhibitor, and we speculate that SNPs in COL18A1 may be associated with susceptibility to HCC. METHODS AND FINDINGS: We carried out a 2-stage association study in 3 independent case-control groups in a total of 1067 chronic hepatitis B (CHB) patients and 808 hepatitis B virus (HBV) related HCC patients in Han Chinese. Four SNPs which can represent all potential functional SNPs with MAF>0.1 recorded in HapMap database were genotyped using TaqMan methods. Levels of total COL18A1 mRNA were also examined using quantitative real-time RT-PCR. We found that rs7499 located in 3'-UTR to be strongly associated with HBV related HCC (P(combined) = 0.0000005, OR = 0.72, 95%CI = 0.63-0.82). COL18A1 mRNA expression was significantly decreased as the disease progressed (P = 0.000026). CONCLUSION: These findings indicate that COL18A1 rs7499 may contribute to the risk of HCC in Han Chinese

    Male Germ Cell-Specific RNA Binding Protein RBMY: A New Oncogene Explaining Male Predominance in Liver Cancer

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    Male gender is a risk factor for the development of hepatocellular carcinoma (HCC) but the mechanisms are not fully understood. The RNA binding motif gene on the Y chromosome (RBMY), encoding a male germ cell-specific RNA splicing regulator during spermatogenesis, is aberrantly activated in human male liver cancers. This study investigated the in vitro oncogenic effect and the possible mechanism of RBMY in human hepatoma cell line HepG2 and its in vivo effect with regards to the livers of human and transgenic mice. RBMY expression in HepG2 cells was knocked down by RNA interference and the cancer cell phenotype was characterized by soft-agar colony formation and sensitivity to hydrogen-peroxide-induced apoptosis. The results revealed that RBMY knockdown reduced the transformation and anti-apoptotic efficiency of HepG2 cells. The expression of RBMY, androgen receptor (AR) and its inhibitory variant AR45, AR-targeted genes insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein 3 (IGFBP-3) was analyzed by quantitative RT-PCR. Up-regulation of AR45 variant and reduction of IGF-1 and IGFBP-3 expression was only detected in RBMY knockdown cells. Moreover, RBMY positive human male HCC expressed lower level of AR45 as compared to RBMY negative HCC tissues. The oncogenic properties of RBMY were further assessed in a transgenic mouse model. Liver-specific RBMY transgenic mice developed hepatic pre-cancerous lesions, adenoma, and HCC. RBMY also accelerated chemical carcinogen-induced hepatocarcinogenesis in transgenic mice. Collectively, these findings suggest that Y chromosome-specific RBMY is likely involved in the regulation of androgen receptor activity and contributes to male predominance of HCC

    Molecular Evolution of the Primate Antiviral Restriction Factor Tetherin

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    Background: Tetherin is a recently identified antiviral restriction factor that restricts HIV-1 particle release in the absence of the HIV-1 viral protein U (Vpu). It is reminiscent of APOBEC3G and TRIM5a that also antagonize HIV. APOBEC3G and TRIM5a have been demonstrated to evolve under pervasive positive selection throughout primate evolution, supporting the redqueen hypothesis. Therefore, one naturally presumes that Tetherin also evolves under pervasive positive selection throughout primate evolution and supports the red-queen hypothesis. Here, we performed a detailed evolutionary analysis to address this presumption. Methodology/Principal Findings: Results of non-synonymous and synonymous substitution rates reveal that Tetherin as a whole experiences neutral evolution rather than pervasive positive selection throughout primate evolution, as well as in non-primate mammal evolution. Sliding-window analyses show that the regions of the primate Tetherin that interact with viral proteins are under positive selection or relaxed purifying selection. In particular, the sites identified under positive selection generally focus on these regions, indicating that the main selective pressure acting on the primate Tetherin comes from virus infection. The branch-site model detected positive selection acting on the ancestral branch of the New World Monkey lineage, suggesting an episodic adaptive evolution. The positive selection was also found in duplicated Tetherins in ruminants. Moreover, there is no bias in the alterations of amino acids in the evolution of the primate Tetherin, implyin

    Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

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    In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field
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