Relationship between apoptotic markers in semen from fertile men and demographic, hormonal and seminal characteristics

Apoptosis in the testis has two putative roles during normal spermatogenesis; limitation of the germ cell population to numbers that can be supported by the Sertoli cells, and, possibly, selective depletion of meiotic and postmeiotic abnormal germ cells. We investigated the demographic and biological correlates of the pro-apoptotic marker Fas and the anti-apoptotic marker Bcl-xL in sperm cells of fertile men. Six hundred and four men from Greenland, Poland and Ukraine were consecutively enrolled during their pregnant wife＇s antenatal visits. Semen analysis was performed as recommended by the World Health Organization. Immunofluorescence coupled to flow cytometry was utilized for detection of apoptotic markers in the sperm cell. DNA damage was assessed by flow cytometry using both the sperm chromatin structure assay （SCSA） and the terminal deoxynucleotidyl transferase dUTP nick end labelling （TUNEL） assay. The percentage of Fas-positive sperm cells was higher in men with high total sperm count （P〈O.01）, more motile sperms （P=-O.04） and fewer sperm head defects （P=-O.05）. These associations were consistent within and across study regions. Furthermore, testosterone, follicle-stimulating hormone （FSH） and sexual hormone-binding globulin （SHBG） were significantly negatively correlated with Fas within and across regions as well. The data indicated no association between the anti-apoptotic Bcl-xL marker and semen or personal characteristics. The finding of Fas-positive sperm cells associated with better semen quality in a cohort of spouses of pregnant women seems different from previous data obtained in infertile men and warrants further investigation to clarify the biological significance of sperm apoptotic markers.

系统综述和荟萃分析优先报告的条目:PRISMA声明

为了提高系统综述和荟萃分析文章报告的质量,2009年由国际著名专家组成的系统综述和荟萃分析优先报告的条目(Preferred Reporting Items for Systematic Reviews and Meta-Analyses,PRISMA)小组在国际重要医学期刊包括《英国医学杂志》、《临床流行病学杂志》、《内科学年鉴》和美国《公共科学图书馆医学杂志》等同步发表了《系统综述与荟萃分析优先报告条目:PRISMA声明》。该标准的制定对于改进和提高系统综述和荟萃分析的报告质量将起到重要作用。该声明较以往制定的《随机对照试验荟萃分析报告质量》(Quality of Reporting of Meta-Analyses),即《QUOROM声明》更加全面、完善。由于近年采国内外对系统综述的高度重视,发表的文章数量也越来越多,因此,有必要规范报告的标准,提高报告的质量。这份声明对系统综述和荟萃分析类文章报告的27个条目及流程图进行了定义和介绍,对相关条目进行了详细的解释和说明。及时向国内读者和临床试验研究人员介绍该声明具有重要的现实意义和学术价值。北京中医药大学循证医学中心刘建平等在第一时间内翻译了该声明,本刊希望通过介绍中文版《系统综述与荟萃分析优先报告的条目:PRISMA声明》,以进一步提高国内系统综述文章撰写和报告的质量,同时也有助于改进研究设计的方法学质量。本文的英文原文"Preferred reporring items for systematic reviews and meta-analyses:the PRISMAstatement"发表于PLoS Med.2009;6(7):e1000097.doi:10.1371/journal.pmed.1000097。该文中文版本由北京中医药大学循证医学中心李迅、曹卉娟翻译,刘建平审校(Tel:010-64286760;E-mail:jianping_l@hotmail.com)。中文译文的翻译出版由国家重点基础研究发展计划(973计划)项目资助(No.200608504602)。

Compact n-Manifolds via(n+l)-Colored Graphs:a New Approach

We introduce a representation via(n+l)-colored graphs of compact n-manifolds with(possibly empty)boundary,which appears to be very convenient for computer aided study and tabulation.Our construction is a generalization to arbitrary dimension of the one recently given by Cristofori and Mulazzani in dimension three,and it is dual to the one given by Pezzana in the 1970s.In this context we establish some results concerning the topology of the represented manifolds:suspensions,fundamental groups,connected sums and moves between graphs representing the same manifold.Classification results of compact orientable 4-manifolds representable by graphs up to six vertices are obtained,together with some properties of the G-degree of 5-colored graphs relating this approach to tensor models theory.

Study of the production of Λ_b^0 band ~0 hadrons in pp collisions and first measurement of the Λ_b^0→J/ψpK^- branching fraction

The product of the ∧0/b （-B/0） differential production cross-section and the branching fraction of the decay ∧0/b→ J/ψ pK-（-B/0→ J/ψ-K＊（892）0）is measured as a function of the beauty hadron transverse momentum, PT, and rapidity, y. The kinematic region of the measurements is pT〈20 GeV/c and 2.0 〈g〈4.5.The measurements use a data sample corresponding to an integrated luminosity of 3fb-1 collected by the LHCb detector in pp collisions at centre-of-mass energies √s=7 TeV in 2011 and √s=8 TeV in 2012. Based on previous LHCb results of the fragmentation fraction ratio,f∧0/b/fd,the branching fraction of the decay ∧0/b→ J/ψ pK-is measured to be B（∧0/b→ J/ψ pK-）=（3.17±0.04±0.07±0.34＋0.45/-0.28）×10-4,where the first uncertainty is statistical, the second is systematic, the third is due to the uncertainty on the branching fraction of the decay -B/0 →J/ψ-K＊（892）0,and the fourth is due to the knowledge of f∧0/b/fd.The sum of the asymmetries in the production and decay between ∧0/b and ∧0/bis also measured as a function of PT and y.The previously published branching fraction of ∧0/b→ J/ψ pπ-,relative to that of ∧0/b→ J/ψ pK-,is updated. The branching fractions of ∧0/b→P＋c（→ J/ψp）K-are determined.

Search for the doubly heavy baryons Ω^(0)_(bc) and E^(0)_(bc) decaying to Λ^(+)_(c)π^(-) and E^(+)_(c)π^(-)

The first search for the doubly heavyΩ^(0)_(bc)baryon and a search for the E^(0)_(bc)baryon are performed using pp collision data collected via the LHCb experiment from 2016 to 2018 at a centre-of-mass energy of 13 TeV,corresponding to an integrated luminosity of 5.2 fb^(-1).The baryons are reconstructed via their decays to Λ^(+)_(c)π^(-)and E^(+)_(c)π^(-).No significant excess is fbund for invariant masses between 6700 and 7300 MeV/c^(2),in a rapidity range from 2.0 to 4.5 and a transverse momentum range from 2 to 20 MeV/c.Upper limits are set on the ratio of the Ω^(0)_(bc)and E^(0)_(bc)production cross-section times the branching fraction to Λ^(+)_(c)π^(-)(E^(+)_(c)π^(-))relative to that of the Λ^(0)_(b)(E^(0)_(b))baryon,for different lifetime hypotheses,at 95%confidence level.The upper limits range from 0.5 x 10^(-4)to 2.5 x 10^(-4)for theΩ^(0)_(bc)→Λ^(+)_(c)π^(-)(E^(0)_(bc)→Λ^(+)_(c)π^(-))decay,and from 1.4x 10^(-3)to 6.9 x 10^(-3)for theΩ^(0)_(bc)→E^(+)_(c)π^(-)(E^(0)_(bc)→E^(+)_(c)π^(-))decay,depending on the considered mass and lifetime of theΩ^(0)_(bc)(E^(0)_(bc))baryon.

Search for the doubly charmed baryon ■

A search for the doubly charmed baryon ■^+cc is performed through its decay to theΛ^+c K^-π^+ final state,using proton-proton collision data collected with the LHCb detector at centre-of-mass energies of 7,8 and 13 TeV.The data correspond to a total integrated luminosity of 9 fb^-1.No significant signal is observed in the mass range from 3.4 to 3.8 GeV/c^2.Upper limits are set at 95%credibility level on the ratio of the ■^+cc production cross-section times the branching fraction to that ofΛ^+c and ■^++cc baryons.The limits are determined as functions of the ■^+cc mass for different lifetime hypotheses,in the rapidity range from 2.0 to 4.5 and the transverse momentum range from 4 to 15 GeV/c.