单孔胸腔镜下肺癌术后胸腔引流时间的影响因素分析北大核心

目的:探讨单孔胸腔镜下肺癌手术术后胸腔引流时间的影响因素。方法:本研究采用回顾性分析方法,回顾我院2018年01月至2019年12月原发性肺癌患者经单孔胸腔镜手术治疗的病例199例。按照术后胸腔引流时间分为两组,Ⅰ组(术后胸腔引流时间<5天)和Ⅱ组(术后胸腔引流时间≥5天)。对于影响术后胸腔引流时间的可能因素在两组间先采用单因素分析的方法筛选,再将筛选出来的对术后胸腔引流时间可能有意义的影响因素进行二项Logistic多因素回归分析。结果:经单因素分析及二项Logistic多因素回归分析结果显示:年龄≥60岁、手术部位、肺段切除术、胸膜粘连、手术时间≥180 min、术后早期下床活动是术后胸腔引流时间的独立影响因素(P<0.05)。结论:对于具有多个延长术后胸腔引流时间的独立影响因素的患者,应制定个体化管理方案,尽可能减少术后胸腔引流时间,减少住院天数,加快患者康复。     

吸毒人员回归社会后的应对方式与生活质量——自我概念的中介作用

目的 本研究旨在探讨吸毒人员回归社会后的自我概念及应对方式是否会影响其生活质量。方法 在四川省成都市、德阳市、西昌市、宜宾市等地招募201名已回归社会的男性吸毒人员（平均年龄22.65±8.31岁，年龄16~59岁）进行调查。参与者完成田纳西自我概念量表（TSCS）、特质应对方式问卷（TCSQ）和药物成瘾者生命质量测定量表（QOL-DA）。结果 高自我概念组吸毒人员的积极应对得分和生活质量均高于低自我概念组，差异具有统计学意义（P<0.05）；吸毒人员的自我概念在积极应对与生活质量之间的中介效应值为0.224（95%CI:0.063~0.434），中介效应显著，占总效应的26.4%。结论 自我概念介导了回归社会的吸毒人员应对方式与生活质量之间的关系，应在学校和特定社区开展提高自我概念和应对技巧的培训。     

近二十年我国大学生睡眠质量研究结果的元分析

目的 对近20年我国大学生睡眠质量研究结果进行元分析，以客观准确地认识当代大学生的睡眠状况。方法 在中国知网、万方、维普、CNKI学术搜索等数据库检索、收集2000-2019年使用匹兹堡睡眠质量指数量表（PSQI）调查我国大学生睡眠质量的研究文献，按照一定标准对文献进行筛选。最终收集189篇文献，775组数据，325 435名被试。运用SPSS 19.0对相关信息进行提取，建立数据库，进行相关统计量的运算。结果 大学生PSQI总分的平均效果量95%置信区间为0.050~0.350；大学生PSQI总分高于常模分（t=4.594，P<0.001），差异具有统计学意义；大学生PSQI总分在性别（t=3.214，P=0.001）和年级（F=21.861，P<0.001）变量上的差异具有统计学意义。结论 我国大学生睡眠质量呈逐渐恶化的趋势，存在性别和年级的差异，需对大学生进行有效的睡眠指导。     

认知正常与轻度认知障碍老年人海马亚区与序列位置效应关系的研究

目的： 研究认知正常与轻度认知障碍老年人海马亚区与序列位置效应的相关性。 方法： 选择2016年1月至2019年1月就诊于首都医科大学附属复兴医院神经内科门诊的21例轻度认知障碍（mild cognitive impairment,MCI）患者作为MCI组,同期选择体检中心及门诊的39位认知正常（normal cognition,NC）者作为对照组。所有受试者均进行成套神经心理学量表评估与头颅核磁共振检查。应用自动化海马亚区分割软件FreeSurfer计算各亚区体积,采用听觉词语学习测验（auditory verbal learning test,AVLT）记录序列位置效应结果,观察2组人群亚区体积的差异,并分析其与序列位置效应的相关性。 结果： MCI组患者海马各亚区体积均小于对照组,但经多重比较的Bonferroni校正后,仅前下托区差异有统计学意义（P<0.05）。该亚区与AVLT延迟回忆总分及首因分数呈正相关。 结论： 与对照组相比,MCI患者海马亚区体积减少,其中前下托萎缩更显著,与长时记忆损害相关。     

Protein crystal structure obtained at 2.9 ? resolution from injecting bacterial cells into an X-ray free-electron laser beam

It has long been known that toxins produced by Bacillus thuringiensis (Bt) are stored in the bacterial cells in crystalline form. Here we describe the structure determination of the Cry3A toxin found naturally crystallized within Bt cells. When whole Bt cells were streamed into an X-ray free-electron laser beam we found that scattering from other cell components did not obscure diffraction from the crystals. The resolution limits of the best diffraction images collected from cells were the same as from isolated crystals. The integrity of the cells at the moment of diffraction is unclear; however, given the short time (∼5 µs) between exiting the injector to intersecting with the X-ray beam, our result is a 2.9-Å-resolution structure of a crystalline protein as it exists in a living cell. The study suggests that authentic in vivo diffraction studies can produce atomic-level structural information.The advent of X-ray free-electron lasers (XFELs) has made it possible to obtain atomic resolution macromolecular structures from crystals with sizes approximating only 1/60th of the volume of a single red blood cell. Brief, intense pulses of coherent X-rays, focused on a spot of 3-μm diameter, have produced 1.9-Å-resolution diffraction data from a stream of lysozyme crystals, each crystal no bigger than 3 μm³ (1). A stream of crystals, not just one crystal, is required to collect the many tens of thousands of diffraction patterns that compose a complete data set. No single crystal can contribute more than one diffraction pattern because the XFEL beam is so intense and the crystals so small that the crystals are typically vaporized after a single pulse. Impressively, a photosystem I crystal no bigger than 10 unit cells (300 nm) on an edge produced observable subsidiary diffraction peaks between Bragg reflections, details which would be unobservable from conventionally sized crystals (2). With this new ability to collect diffraction patterns from crystals of unprecedentedly small dimensions, it is conceivable that high-resolution diffraction data could be collected from crystals in vivo. The structure obtained in this manner would be unaltered from that occurring naturally in a living cell, free from distortion that might otherwise potentially arise from nonphysiological conditions imposed by recrystallization. A practical advantage would also be gained by eliminating the need for a protein purification step, whether the in vivo grown crystals were naturally, or heterologously expressed (3).The nascent field of serial femtosecond crystallography (SFX) has published results on nine different macromolecular systems since its inception in 2009 (3, 9). The crystals for this study were not grown in artificial crystallization chambers as has been the protocol of conventional macromolecular crystallography since the 1950s. Instead, crystals were grown in cells. Specifically, they were grown in Sf9 insect cells, heterologously expressing Trypanosoma brucei cathepsin B. These in vivo-grown crystals were used for the XFEL diffraction experiment. To this end, the cells were lysed and the crystals were extracted before injecting them in the XFEL beam for data collection. This last purification step seems to be the only major departure from our goal of obtaining high-resolution structural information from crystal inclusions in vivo, without requiring the crystal to be extracted from the cell that assembled it. Here we attempt to go one step further than previous studies—to record diffraction from crystals within living cells.

Table 1.

SFX publications from XFEL sources to date

基于单片机的功能磁共振同步器的设计

目的：设计一种处理功能磁共振成像( fMRI)同步输出信号的同步器,对其解决同步问题的性能进行鉴定。方法fMRI在采集图像数据时,有两种同步信号输出方式：其一,采集一幅完整脑图时,每采集一层图像输出一个同步方波信号;其二,采集完一幅脑图输出一个同步信号。首先设定一幅完整脑图的采集层数,也称同步参数( SP);然后采集第一种同步方波信号,用单片机外部中断方法对第一种同步方波信号的上升沿计数,并保持初始输出为高电平;直到最后一层脑图时,将输出信号置为低电平并延时一段时间。结果同步器成功将第一种同步方波信号处理成第二种同步信号;matlab编程串口程序自动化设定SP,通过串口传输至单片机;结果表明该同步器可自动化设置SP。结论设计的同步器能使某类功能磁共振输出同步信号的同步问题得以解决,设备兼容性得到提升,其自动化设置SP,可减少医护人员的工作量。     

Aspects of grammar sensitive to procedural memory deficits in children with specific language impairment

Procedural deficit hypothesis claims that language deficit in children with specific language impairment is affiliated to sequence learning problems. However, studies did not explore on aspects of grammar vulnerable to sequence learning deficits. The present study makes predictions for aspects of grammar that could be sensitive to procedural deficits based on core ideas of procedural deficit hypothesis. The hypothesis for the present study was that the grammatical operations that require greater sequencing abilities (such as inflectional operations) would be more affected in children with language impairment. Further, the influence of sequencing difficulties would be even greater in agglutinating inflectional languages. An adapted serial reaction time task for sequence learning measurements along with grammatical tasks on derivation, inflection, and sentence complexity were examined on typically developing and language impaired children. Results were in favor of procedural deficit hypothesis and its close relation to non-adjacent grammatical operations. The findings were discussed using procedural deficits, declarative compensatory mechanism, and statistical learning deficits.     

Relevancia del efecto de posición serial en el diagnóstico diferencial entre el deterioro cognitivo leve,la demencia de tipo Alzheimer y el envejecimiento normal

Serial position effects are observed when a person memorises a series of words exceeding his or her attention span. Cognitively normal individuals recall words at the beginning and end of the list more frequently than those in the middle, which reflects the way that short- and long-term episodic memory works.     

Short bowel mucosal morphology,proliferation and inflammation at first and repeat STEP procedures

Background

Although serial transverse enteroplasty (STEP) improves function of dilated short bowel, a significant proportion of patients require repeat surgery. To address underlying reasons for unsuccessful STEP, we compared small intestinal mucosal characteristics between initial and repeat STEP procedures in children with short bowel syndrome (SBS).