565 research outputs found

    Pilus of Streptococcus pneumoniae: structure, function and vaccine potential

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    The pilus is an extracellular structural part that can be detected in some Streptococcus pneumoniae (S. pneumoniae) isolates (type I pili are found in approximately 30% of strains, while type II pili are found in approximately 20%). It is anchored to the cell wall by LPXTG-like motifs on the peptidoglycan. Two kinds of pili have been discovered, namely, pilus-1 and pilus-2. The former is encoded by pilus islet 1 (PI-1) and is a polymer formed by the protein subunits RrgA, RrgB and RrgC. The latter is encoded by pilus islet 2 (PI-2) and is a polymer composed mainly of the structural protein PitB. Although pili are not necessary for the survival of S. pneumoniae, they serve as the structural basis and as virulence factors that mediate the adhesion of bacteria to host cells and play a direct role in promoting the adhesion, colonization and pathogenesis of S. pneumoniae. In addition, as candidate antigens for protein vaccines, pili have promising potential for use in vaccines with combined immunization strategies. Given the current understanding of the pili of S. pneumoniae regarding the genes, proteins, structure, biological function and epidemiological relationship with serotypes, combined with the immunoprotective efficacy of pilins as protein candidates for vaccines, we here systematically describe the research status and prospects of S. pneumoniae pili and provide new ideas for subsequent vaccine research and development

    miR-181a increases FoxO1 acetylation and promotes granulosa cell apoptosis via SIRT1 downregulation.

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    Oxidative stress impairs follicular development by inducing granulosa cell (GC) apoptosis, which involves enhancement of the transcriptional activity of the pro-apoptotic factor Forkhead box O1 (FoxO1). However, the mechanism by which oxidative stress promotes FoxO1 activity is still unclear. Here, we found that miR-181a was upregulated in hydrogen peroxide (

    The Application of Downhole Vibration Factor in Drilling Tool Reliability Big Data Analytics - A Review

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    In the challenging downhole environment, drilling tools are normally subject to high temperature, severe vibration, and other harsh operation conditions. The drilling activities generate massive field data, namely field reliability big data (FRBD), which includes downhole operation, environment, failure, degradation, and dynamic data. Field reliability big data has large size, high variety, and extreme complexity. FRBD presents abundant opportunities and great challenges for drilling tool reliability analytics. Consequently, as one of the key factors to affect drilling tool reliability, the downhole vibration factor plays an essential role in the reliability analytics based on FRBD. This paper reviews the important parameters of downhole drilling operations, examines the mode, physical and reliability impact of downhole vibration, and presents the features of reliability big data analytics. Specifically, this paper explores the application of vibration factor in reliability big data analytics covering tool lifetime/failure prediction, prognostics/diagnostics, condition monitoring (CM), and maintenance planning and optimization. Furthermore, the authors highlight the future research about how to better apply the downhole vibration factor in reliability big data analytics to further improve tool reliability and optimize maintenance planning

    Building information modeling integrated with electronic commerce material procurement and supplier performance management system

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    This paper describes an innovative approach to the integration of Building Information Modeling (BIM) and electronic commerce (e-commerce) in a material procurement process for improved design-construction integration. The paper includes the present applications, benefits, limitations and barriers to e-commerce and BIM in material procurement processes, compares the present commercial BIM based and non-BIM based quantity takeoff and cost estimating software, and identifies potential benefits of integrating BIM and e-commerce software solutions for construction quantity takeoff, cost estimating and procurement processes. The authors propose a framework for integrating BIM for quantity takeoff and cost estimating applications with e-commerce solutions for material procurement and supplier performance evaluation. The paper presents a proposed solution to link BIM-derived data with RS Means unit price cost data to generate accurate cost estimating reports, one weight coefficient-based model to evaluate the performance of material suppliers, and a preliminary version of corresponding BIM-based application integrated with e-commerce software system

    sSgo1, a Major Splice Variant of Sgo1, Functions in Centriole Cohesion Where It Is Regulated by Plk1

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    SummaryShugoshin 1 (Sgo1) functions as a protector of centromeric cohesion of sister chromatids in higher eukaryotes. Here, we provide evidence for a previously unrecognized role for Sgo1 in centriole cohesion. Sgo1 depletion via RNA interference induces the formation of multiple centrosome-like structures in mitotic cells that result from the separation of paired centrioles. Sgo1+/− mitotic murine embryonic fibroblasts display split centrosomes. Localization study of two major endogenous splice variants of Sgo1 indicates that the smaller variant, sSgo1, is found at the centrosome in interphase and at spindle poles in mitosis. sSgo1 interacts with Plk1 and its spindle pole localization is Plk1 dependent. Centriole splitting induced by Sgo1 depletion or expression of a dominant negative mutant is suppressed by ectopic expression of sSgo1 or by Plk1 knockdown. Our studies strongly suggest that sSgo1 plays an essential role in protecting centriole cohesion, which is partly regulated by Plk1

    NSUN2‐Mediated m5C Methylation and METTL3/METTL14‐Mediated m6A Methylation Cooperatively Enhance p21 Translation

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    N6‐methyladenosine (m6A) and m5C methylation are two major types of RNA methylation, but the impact of joint modifications on the same mRNA is unknown. Here, we show that in p21 3′UTR, NSUN2 catalyzes m5C modification and METTL3/METTL14 catalyzes m6A modification. Interestingly, methylation at m6A by METTL3/METTL14 facilitates the methylation of m5C by NSUN2, and vice versa. NSUN2‐mediated m5C and METTL3/METTL14‐mediated m6A methylation synergistically enhance p21 expression at the translational level, leading to elevated expression of p21 in oxidative stress‐induced cellular senescence. Our findings on p21 mRNA methylation and expression reveal that joint m6A and m5C modification of the same RNA may influence each other, coordinately affecting protein expression patterns. J. Cell. Biochem. 118: 2587–2598, 2017. © 2017 Wiley Periodicals, Inc.In p21 3’UTR,NSUN2 catalyzes m5C modification and METTL3/METTL14 catalyzes m6A modification. Methylation at m6A by METTL3/METTL14 facilitates the methylation of m5C by NSUN2, and vice versa. NSUN2‐mediated m5C and METTL3/METTL14‐mediated m6A methylation synergistically enhance p21 expression at the translational level, leading to elevated expression of p21 in oxidative stress‐induced cellular senescence.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137760/1/jcb25957.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137760/2/jcb25957_am.pd

    Atypical Frontotemporal Connectivity of Cognitive Empathy in Male Adolescents With Conduct Disorder

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    Background: It has been suggested that adolescents with conduct disorder (CD) may have a deficit in the affective and cognitive domains empathy, but studies exploring networks within the key brain regions of affective and cognitive empathy in adolescents with CD are lacking.Methods: Functional connectivity (FC) analyses among key brain regions of the affective and cognitive empathy with resting-state functional magnetic resonance imaging (fMRI) were conducted in 30 adolescent boys with CD and 33 demographically matched healthy controls (HCs).Results: Atypical FC within the key brain regions of affective empathy was not observed in CD adolescents. However, we found that CD adolescents showed decreased frontotemporal connectivity within the key brain regions of cognitive empathy in relation to HCs, that is, the FCs between right temporoparietal junction and ventromedial prefrontal cortex as well as dorsomedial prefrontal cortex.Conclusion: These findings may provide insight into neural mechanism underlying a cognitive empathy deficiency of CD adolescents from the perspective of FC

    Risk of Bias Tool in Systematic Reviews/Meta-Analyses of Acupuncture in Chinese Journals

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    BACKGROUND: Use of a risk of bias (ROB) tool has been encouraged and advocated to reviewers writing systematic reviews (SRs) and meta-analyses (MAs). Selective outcome reporting and other sources of bias are included in the Cochrane ROB tool. It is important to know how this specific tool for assessing ROB has been applied since its release. Our objectives were to evaluate whether and to what extent the new Cochrane ROB tool has been used in Chinese journal papers of acupuncture. METHODS: We searched CBM, TCM database, CJFD, CSJD, and the Wanfang Database from inception to March 2011. Two reviewers independently selected SRs that primarily focused on acupuncture and moxibustion, from which the data was extracted and analyzed. RESULTS: A total of 836 SRs were identified from the search, of which, 105 were included and four are awaiting assessment. Thirty-six of the 105 SRs were published before release of the Cochrane ROB tool (up to 2009). Most used the Cochrane Handbook 4.2 or Jadad's scale for risk or quality assessment. From 2009 to March 2011 69 SRs were identified. While "risk of bias" was reported for approximately two-thirds of SRs, only two SRs mentioned use of a "risk of bias tool" in their assessment. Only 5.8% (4/69) of reviews reported information on all six domains which are involved in the ROB tool. A risk of bias graph/summary figure was provided in 2.9% (2/69) of reviews. Most SRs gave information about sequence generation, allocation concealment, blindness, and incomplete outcome data, however, few reviews (5.8%; 4/69) described selective reporting or other potential sources of bias. CONCLUSIONS: The Cochrane "risk of bias" tool has not been used in all SRs/MAs of acupuncture published in Chinese Journals after 2008. When the ROB tool was used, reporting of relevant information was often incomplete
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