Correlation between use of social software and high risk behaviors of HIV infection among MSM in Beijing

目的了解北京市男男性行为者（MSM）社交软件的使用与人类免疫缺陷病毒（HIV）感染及其影响因素的相关性,为今后干预工作提供依据。方法 2016年3—5月,由社区小组招募MSM进行问卷调查,同时进行HIV抗体检测。结果共招募215名MSM,回收有效问卷214份。214人的平均年龄为30.8岁;学历在大专及以上者占73.4%;同性恋者占72.4%;84.6%的人主要通过社交软件寻找性伴。214人中确证HIV感染5人,阳性率为2.3%。分析显示,是否使用社交软件、是否使用同性社交软件和是否使用普通人群社交软件均与HIV感染不相关。多因素分析结果显示,受教育程度高、性取向为同性恋的人更多地使用同性社交软件。63.1%被调查者自述曾经在社交软件上了解到艾滋病防治相关知识,但自述了解程度与是否通过社交软件获得相关信息不相关。结论 MSM社交软件的使用与HIV感染情况无关,也没有增加其对艾滋病知识的了解。但可以考虑改进同性社交软件功能,增加艾滋病防治知识内容,对MSM尤其是高学历、自我定位为同性恋的MSM进行艾滋病防治宣传。[Objective] To understand the correlation between the use of social software and human immunodeficiency virus（HIV）infection and its influencing factors among men who have sex with men（MSM）in Beijing,provide the basis for future intervention work.[Methods]From May to March in 2016,MSM was recruited by community groups to carry out a questionnaire survey and HIV antibody of them was detected.[Results]A total of 215 MSM were recruited and 214 valid questionnaires were recovered. The average age of the 214 MSM was 30.8 years old,73.4% had the education level in college and above,the homosexuals accounted for 72.4%,and84.6% of the respondents mainly found sexual partners through the social software. There were 5 cases of confirmed HIV infection among 214 MSM with the positive rate of 2.3%. The analysis revealed that whether the respondents use the social software,the homosexual social software and the general social software were not related to HIV infection. The results of multivariate analysis showed that people with higher educational level and homosexual orientation were more likely to use the homosexual social software. 63.1% of respondents reported that they had been obtained the knowledge of AIDS prevention and control from social software,but the understanding level was not related to whether the relevant information was obtained through social software or not.[Conclusion]The use of social software has no correlation with HIV infection among MSM,and does not increase their knowledge level of AIDS prevention and control. However,it is necessary to improve the function of the homosexual social software and increase the content of AIDS prevention and control knowledge to carry out the AIDS education among MSM,especially those with higher educational level and homosexual orientation

《黄帝内经》胃本源理论临床意义及对消化系统肿瘤防治的作用

文章通过对《黄帝内经》经文"胃者,五脏之本也"的深入理解,从生理和病理角度,论述了胃对于正常机体、疾病的产生、病情判断及临床用药等方面的重要作用与指导意义;并从胃五脏本源的角度对消化系统恶性肿瘤食管癌、胃癌、大肠癌、原发性肝癌、胆管癌、胰腺癌的认识和防治进行了理论阐述

Combined Use of Thoracoscopy and Laparoscopy in Total Laryngectomy for Cervical Esophageal Carcinoma

目的探讨胸、腹腔镜联合全喉切除治疗颈段食管的可行性和疗效。方法 2009年1月~2014年7月胸、腹腔镜联合全喉切除治疗33例颈段食管癌。胸腔镜下分离食管、腹腔镜下管胃成形、全喉切除、气管永久造口、胃咽吻合术。结果胸部手术时间40~66 MIn,平均53 MIn;腹部手术时间35~51 MIn,平均44 MIn;颈部手术时间128~150 MIn,平均139 MIn。术中出血量130~270 Ml,平均150 Ml。术后住院时间8~14 d,平均12 d。病理均为鳞状细胞癌,其中高分化2例,中分化19例,中-低分化7例,低分化5例。切缘病理学检查无癌组织残留。31例淋巴结转移。并发症:吻合口漏2例,喉返神经损伤3例,肺部感染6例,胃排空障碍2例,吻合口狭窄1例,无死亡病例。33例随访1个月~5年,术后1、3、5年生存率分别为87.9%、54.5%、45.5%。结论颈段食管癌应采取积极的手术治疗,胃咽吻合术是颈段食管癌切除后较为理想的修复手段。Objective To investigate clinical feasibility and efficacy of combined use of thoracoscopy and laparoscopy in total laryngectomy for cervical esophageal carcinoma.Methods Clinical data of 33 patients with cervical esophageal carcinoma undergoing surgical treatment in our department from January 2009 to July 2014 were analyzed retrospectively.The esophagus was separated under thoracoscopy.And laparoscopic gastroplasty,total laryngectomy,tracheal permanent colostomy,and gastric pharyngeal anastomosis were performed.Results The thoracoscopic operation time was 40- 66 min( mean,53 min),the laparoscopic operation time was 35- 51 min( mean,44 min),and the cervical operation time was 128- 150 min( mean,139 min).The blood loss was 130- 270 ml( mean,150 ml).The postoperative hospital stay was 8- 14 d( mean,12 d).Pathological examinations showed squamous cell carcinoma in all the cases,including 2 cases of highly differentiated carcinoma,19 cases of moderately differentiated carcinoma,7 cases of moderately or lowly differentiated carcinoma,and 5 cases of lowly differentiated carcinoma.No residual cancer was found at cutting edges pathologically.Among the 33 cases,lymph node metastasis was found in 31 cases.Complications included 2 cases of anastomotic fistula,3 cases of recurrent laryngeal nerve injury,6 cases of pulmonary infection,2cases of delayed gastric emptying,and 1 case of anastomotic stenosis.There was no death.All the patients were followed up for 1months to 5 years.The survival rates at 1,3,and 5 postoperative year were 87.9%,54.5%,and 45.5%,respectively.Conclusions Cervical esophageal carcinoma should be surgically treated actively.Gastric pharyngeal anastomosis is an ideal option for the repair of cervical esophageal cancer resection

Video-assisted Thoracoscopic 3D Mode Operation for Solitary Pulmonary Nodules

目的探讨三维胸腔镜手术(3d VIdEO-ASSISTEd THOrACIC SurgEry,3d-VATS治疗孤立性肺结节(SOlITAry PulMOnAry nOdulE,SPn)的效果。方法回顾性分析2013年3月~2014年3月50例SPn的资料,采用3d-VATS手术模式楔形切除结节,根据快速病理结果决定是否行肺叶切除加淋巴结清扫术。统计手术时间(去除快速冰冻时间)、术后24 H引流量、总引流量、引流管拔除时间、淋巴结清扫数及术后并发症等。结果 3d-VATS模式下,50例均行肺结节楔形切除,其中23例病理为恶性,继续行肺癌根治术,手术顺利。肺癌根治术手术时间(62±12)MIn,术中出血量(35±5)Ml,清扫淋巴结(19±3)个,术后24 H引流量(120±20)Ml,术后胸管引流时间(4±1)d,术后住院时间(7±2)d。并发症3例,其中术后肺炎2例,阵发性心房纤颤1例,均治愈。无围手术期死亡。随访2~12个月,平均6.3月。1例术后3个月脑转移,1例术后5个月肺癌复发。结论胸腔镜3d模式下治疗SPn是一种新的选择方式,安全可行,值得推广应用。Objective To evaluate the effects of surgical treatment for solitary pulmonary nodules under thoracoscopic 3D mode(3D-VATS).Methods A total of 50 cases of solitary pulmonary nodules from March 2013 to March 2014 were retrospectively analyzed.Intraoperative wedge pulmonary resection with 3D-VATS was utilized.According to intraoperative pathological findings,lobectomy plus lymph node dissection was given or not.Intraoperative time( minus fast freezing time),drainage volume for 24 h,total drainage volume,drainage tube removal time,number of lymph node dissected,and postoperative complications were recorded.Results Under 3D-VATS mode,50 cases of solitary pulmonary nodules were treated with wedge resection,including 23 cases of malignant pathology receiving radical resection, which was smoothly.The radical resection time( lung lobectomy plus lymphadenectomy) was(62 ± 12) min,the bleeding volume was(35 ± 5) ml,the lymphadenectomy number was 19 ± 3,the drainage volume for 24 h was(120 ± 20) ml,the postoperative chest tube removal time was(4 ± 1) days,and the postoperative hospital stay was(7 ± 2) days.Postoperative complications occurred in 3 cases,including 2 cases of pneumonia and 1 case of paroxysmal atrial fibrillation.No perioperative deaths were observed.All the cases were followed up for 2- 12 months,with an average of 6.3 months.Brain metastases was found in 1 case at the third postoperative month and recurrence of lung cancer was noted in 1 case at the fifth postoperative month.Conclusion Thoracoscopic 3D mode treatment for solitary pulmonary nodules is a new,safe,and feasible alternative and should be widely applied

Flexible decapyrrylcorannulene hosts

球形笼状的富勒烯是上个世纪末最重要的科学发现之一，但对富勒烯的精确几何结构的认识却困难重重，原因是单晶中球形分子的取向往往是无序的，需通过笼外衍生或通过八乙基金属卟啉-富勒烯超分子主客体组装来固定富勒烯的取向，然后利用常用的单晶衍射分析技术来精确表征富勒烯的几何结构。然而许多富勒烯新结构因无法与卟啉主体形成高质量的单晶至今仍无法利用X射线衍射技术进行结构分析，直接制约了对富勒烯形成机理及结构-性能关系的深入认识。功能团簇材料创新研究群体的谢素原、张前炎课题组另辟蹊径地从曲面结构的十氯碗烯C20Cl10出发，合成了十吡咯取代的碗烯分子C20(C4H4N)10。结构分析表明该分子的结构特征是碗烯的碳框架与十个吡咯基团通过单键相连。实验还证明，用甲基去取代吡咯3, 4-位置的氢并不利于富勒烯与碗烯衍生物形成有序的超分子组装体，理论研究进一步诠释了十个吡咯‘手指’的集体贡献比单个碗烯‘手掌’更大的原因。该研究工作是功能团簇材料创新研究群体长期积累，并由校内外十多位研究人员共同努力完成。徐云彦（2014级硕士生）、田寒蕊（2014级博士生）和李姝慧（2016年进站博士后）为该论文共同第一作者。【Abstract】The assembly of spherical fullerenes, or buckyballs, into single crystals for crystallographic identification often suffers from disordered arrangement. Here we show a chiral configuration of decapyrrylcorannulene that has a concave ‘palm’ of corannulene and ten flexible electron-rich pyrryl group ‘fingers’ to mimic the smart molecular ‘hands’ for self-adaptably cradling various buckyballs in a (+)hand-ball-hand(−) mode. As exemplified by crystallographic identification of 15 buckyball structures representing pristine, exohedral, endohedral, dimeric and hetero-derivatization, the pyrryl groups twist with varying dihedral angles to adjust the interaction between decapyrrylcorannulene and fullerene. The self-adaptable electron-rich pyrryl groups, susceptible to methylation, are theoretically revealed to contribute more than the bowl-shaped palm of the corannulene in holding buckyball structures. The generality of the present decapyrrylcorannulene host with flexible pyrryl groups facilitates the visualization of numerous unknown/unsolved fullerenes by crystallography and the assembly of the otherwise close-packed spherical fullerenes into two-dimensional layered structures by intercalation.This research was supported by the National Natural Science Foundation of China (21771152, 21721001, 21827801, 51572231, 51572254, 21571151, 2170010228), the 973 Program of China (2014CB845601 and 2015CB932301), the China Postdoctoral Science Foundation (2016M602067), the National Key Research and Development Program of China (2017YFA0402800), and the Fundamental Research Funds for the Central Uni- versities (20720170028, 20720160084). Q.Y.Z. is particularly grateful to 21771152, 2015CB932301, 20720170028, 20720160084; S.F.Y. is particularly grateful to 51572254 and 2017YFA0402800; S.Y.X. is particularly grateful to 21721001 and 51572231; L.S.Z. is particularly grateful to 21827801; S.L.D. is particularly grateful to 21571151; S.H.L. is particularly grateful to 2170010228 and 2016M602067. 研究工作得到国家自然科学基金（21771152、21721001、21827801、51572231、51572254, 21571151、2170010228）、科技部973计划（2014CB845601、2015CB932301）和重点研发计划（2017YFA0402800）、国家博士后科学基金、中央高校基本科研业务费等的资助

Selective dynamical imaging of interferometric data

Recent developments in very long baseline interferometry (VLBI) have made it possible for the Event Horizon Telescope (EHT) to resolve the innermost accretion flows of the largest supermassive black holes on the sky. The sparse nature of the EHT’s (u, v)-coverage presents a challenge when attempting to resolve highly time-variable sources. We demonstrate that the changing (u, v)-coverage of the EHT can contain regions of time over the course of a single observation that facilitate dynamical imaging. These optimal time regions typically have projected baseline distributions that are approximately angularly isotropic and radially homogeneous. We derive a metric of coverage quality based on baseline isotropy and density that is capable of ranking array configurations by their ability to produce accurate dynamical reconstructions. We compare this metric to existing metrics in the literature and investigate their utility by performing dynamical reconstructions on synthetic data from simulated EHT observations of sources with simple orbital variability. We then use these results to make recommendations for imaging the 2017 EHT Sgr A* data sethttp://iopscience.iop.org/2041-8205Physic

不同取向选区激光熔化Ti-6Al-4V超高周疲劳特性研究

选区激光熔化是一种常用的增材制造工艺，具有无模具、可定制等优势，拥有良好的应用前景。但其打印过程中产生的缺陷会对其疲劳性能产生不良影响，尤其是对其超高周疲劳（即疲劳周次超过107的疲劳破坏）性能影响巨大。因此对选区激光熔化合金材料超高周疲劳性能的研究有很重要的科学意义和实用价值。 本文研究了打印取向对选区激光熔化合金Ti-6Al-4V高周及超高周疲劳性能的影响。疲劳试样制备取向与加载方向的角度分别为0&deg;，45&deg;，90&deg;。疲劳试验所使用的是超声疲劳试验机（加载频率为20 kHz&plusmn;500 Hz）,应力比设置为-1（即正负应力幅值相等）。试验结果表明，三种不同打印取向的疲劳性能从高到低依次为0&deg;，45&deg;和90&deg;。无论是高周还是超高周疲劳阶段，疲劳裂纹均萌生于内部缺陷。缺陷可以根据几何形状分为规则缺陷和不规则缺陷，90&deg;样品具有最多的不规则缺陷。在缺陷外呈现&ldquo;粗糙区 (rough area)&rdquo;和 &ldquo;鱼眼区 (fish eye)&rdquo;形貌，粗糙区和鱼眼区被称为钛合金的超高周疲劳特征区。缺陷的应力强度因子幅值随着疲劳周次的增加而降低。 本文使用了基于正态分布的概率统计模型对S-N数据进行统计分析。该模型认为在同一载荷下，疲劳周次服从正态分布，而诱导裂纹萌生的缺陷服从极值分布。通过概率统计模型可以预测疲劳周次在109时的超高周疲劳强度，超高周疲劳强度的平均值从高到低依次为217 MPa (0&deg;)，201 MPa (45&deg;)和155 MPa (90&deg;)。 超高周疲劳裂纹萌生特征区消耗了百分之九十以上的疲劳寿命。因此，本文研究了特征区的尺寸特征和微结构演化。粗糙区的尺寸随着载荷的增大而逐渐减小。粗糙区的等效应力强度因子的范围在3-7 。使用聚焦离子束技术提取了裂纹源区附近的纵剖面，并使用透射电子显微镜和扫描电子显微镜对样品进行了观察。即使在高周疲劳区域，选区激光熔化Ti-6Al-4V的特征区表面也出现了尺度在100 nm左右的纳米晶且纳米晶不连续。特征区的微结构在循环载荷的作用下从原始片层组织转变为较小晶粒最终形成纳米晶。这一结果证实了&ldquo;大数往复挤压&rdquo;机制主导了选区激光熔化Ti-6Al-4V疲劳裂纹的萌生和早期扩展以及超高周疲劳特征区的形成。即循环载荷下，由于裂纹面千万次的挤压而导致晶粒细化。 本文利用有限元方法对缺陷附近的应力集中和裂纹扩展过程中裂纹面的接触应力进行了计算。随着缺陷与加载方向的变化，缺陷处的应力集中分布也发生变化。90&deg;样品有着较高的集中应力和最大的应力集中范围。裂纹扩展过程中，由于裂纹闭合效应的存在，接触应力最大值出现在裂纹萌生处和裂纹尖端。此外，随着裂纹长度增加，裂纹尖端残余塑性变形增大，裂纹尖端的接触应力也随之增大。 本文的研究不仅为增材制造的广泛应用提供了数据支持，同时也扩宽了超高周疲劳的研究范围。</p

模拟滨海湿地对氮、磷营养盐污染的净化作用研究

湿地由于参与水文循环和化学循环以及接受自然和人为的废水排泄的特殊功能，被人们誉为“自然之肾”，是人类最重要的环境资本之一，也是自然界富有生物多样性和较高生产力的生态系统。滨海湿地是海陆间的一种过渡区域，也是海洋作用、大气过程、生物作用、地质过程和人类活动相互作用最活跃的耦合带，兼有独特而显著的自然特征和社会特征双重性，对海岸带生态系统及人类社会具有其独特的功能和价值