基于互联网的新型冠状病毒肺炎健康咨询服务分析

目的 分析2020年1月我国新型冠状病毒肺炎(corona virus disease 2019,COVID-19,简称新冠肺炎)疫情初期,政府,医院,公司如何启动互联网技术参与医疗服务,为进一步利用信息技术改善疫情中后期和后疫情时期的医疗服务提出建议.方法: 利用百度等搜索引擎以"互联网+肺炎"等为关键词,搜索2020年1月20日至2月3日的疫情相关互联网健康服务项目信息,由双人背对背提取关键信息并编码,录入信息并进行描述性分析.结果: 10余天时间中,有27家医院,19个公司开通新冠肺炎线上咨询服务,有9个省市组织了区域性线上服务.大多数项目在1月24日至27日启动,集中在少数省份,100.00%的医院和90.48%的公司项目开通发热及肺炎咨询服务,37.04%的医院和66.67%的公司项目提供衍生健康问题咨询,少数项目开展远程会诊,有个别项目提供针对居家隔离人员的线上健康管理.医师是线上工作的主力,也有护士,药师等专业技术人员参与.结论: 互联网技术为改善医疗服务体系在疫情初期的快速反应提供了条件,具备制度和技术可行性,但地区发展不均衡,基层医疗机构参与度不高,没有通过互联网实现医疗体系的联动与协同.应推动省级卫生健康委员会组织远程会诊,推进基层卫生机构开展"互联网+医疗",促进机构之间的协同联动,缓解疫情时期的诊疗压力,改善后疫情时代的医疗服务.     

等离子针状电极在经尿道近输尿管口膀胱肿瘤切除术中的临床应用(附16例报道)

目的: 探讨等离子针状电极在经尿道近输尿管口膀胱肿瘤切除术中的应用价值。方法: 回顾性分析北京大学国际医院泌尿外科2015年6月至2019年12月期间收治的16例接受经尿道等离子针状电极切除的近输尿管口膀胱肿瘤患者的临床资料。肿瘤基底部距离输尿管口1 cm以内者7例,其中侵犯输尿管口者2例,距输尿管口1~2 cm者9例。全部研究对象术前均明确诊断并除外手术禁忌,采用等离子针状电极对肿瘤进行整块切除,将全部切除组织送病理检查,术后行规律灌注治疗并随访。对手术时间、闭孔神经反射发生率、出血量、输尿管导管或双猪尾管留置情况、术后肾积水发生率、肿瘤临床分期、复发率等进行统计分析。结果: 16例患者均顺利完成手术,手术时间16~57 min,平均(32.6±11.8) min,所有患者均未发生明显闭孔神经反射及围手术期出血。术中肿瘤切除前需要预置输尿管导管7例,术后继续留置输尿管导管4例,更换留置双猪尾管3例。术后病理提示所有肿瘤均为尿路上皮癌,其中低级别9例、高级别7例;病理分期:Ta期10例、T1期5例、T2a期1例,所有肿瘤基底部及侧切缘均为阴性。所有患者接受3~56个月的随访,平均(26.0±18.1)个月,无1例出现上尿路积水和肿瘤复发。结论: 经尿道等离子针状电极可以整块切除膀胱肿瘤,减少闭孔神经反射并有效保护输尿管口结构,是一种治疗近输尿管口膀胱肿瘤安全、有效的手术方式。     

新时代图书馆文献资源共建共享的挑战与机遇

通过调研国内外图书馆文献资源共建共享现状和梳理当前图书馆资源建设的资源海量化和多样化、内容服务智慧化、获取去中心化、技术智能化、传播泛在化、保存战略化等新特征,分析了文献资源实现共建共享在资源数量、规范、存储和服务等方面的挑战和机遇,从政策和资金、资源和技术、理念和信任、机制和沟通等方面提出了开展共建共享工作的相关建议,为有效推进图书馆资源建设、提高文献资源服务能力提供参考。     

褐藻酸硫酸酯凝胶剂的质量考察及安全性研究

目的 制备褐藻酸硫酸酯凝胶剂,并对其进行质量考察及安全性评价。方法 以褐藻酸硫酸酯为有效成分制备凝胶剂,从外观、装样量、酸碱度、粘度、有效成分含量及微生物限度方面对凝胶剂质量进行考察,并对其生物安全性进行评价,包括细胞毒性、刺激性及致敏性。结论 制备得到了性状良好、性质稳定的褐藻酸硫酸酯凝胶剂,并且具有较高的生物安全性,为后期褐藻酸硫酸酯药物或医用功能制品的开发奠定了基础。     

Seroprevalence and risk factors of Chlamydia infection in dogs in Southwestern China

Chlamydia spp. are obligate intracellular bacteria distributed globally, known to cause various forms of diseases in animals and humans. To date, there is limited information about the seroprevalence of Chlamydia and the risk factors associated with Chlamydia infection in dogs in the world. In the present study, a serological survey was undertaken to examine the seroprevalence and risk factors associated with dog chlamydiosis in Yunnan Province, southwestern China. A total of 591 dogs were sampled, antibodies to Chlamydia were determined by indirect hemagglutination assay (IHA). The overall seroprevalence was estimated at 17.6%. The risk factors associated with seroprevalence were determined by a multivariate logistic regression analysis. Gender and age of dogs were not significant in the logistic regression analysis (P > 0.05) and left out of the final model. Type and geographical origin of dogs were considered as main risk factors associated with Chlamydia infection, stray dogs (31.37%) were more than 16 times (OR = 16.167, 95% CI = 6.283–41.599, P < 0.01) at risk of acquiring the infection compared to the police dogs (7.62%), while pet dogs (14.41%) had a 3 times (OR = 2.968, 95% CI = 1.349–6.529, P = 0.007) higher risk. Positive dogs were found in 5 districts of Yunnan Province with prevalence ranging from 2.56% to 31.67% except Diqing (0/56). Dogs in Kunming (20.21%) had a 9 times higher risk of being seropositive compared to dogs in Lijiang (2.56%) (OR = 9.057, 95% CI = 1.211–67.714, P = 0.032), although no regional differences were found in other 4 administrative divisions compared to Lijiang (P > 0.05). Our study revealed a widespread and high prevalence of Chlamydia infection in dogs in Yunnan Province, southwestern China, with higher exposure risk in stray dogs and distinct geographical distribution. These findings suggest the potential importance of dogs in the transmission of zoonotic Chlamydia infection, and thus Chlamydia should be taken into consideration in diagnosing dog diseases.     

左旋氨氯地平联合一线降压药治疗高血压疗效的系统评价

目的：系统评价左旋氨氯地平联合一线降压药治疗高血压的疗效,为临床提供循证依据。方法：计算机检索Ovid Medline、EMBase、Cochrane Library、CNKI、CBM、VIP和WanFang Data,检索时限均从建库至2017年12月,对每项纳入研究进行偏倚风险评价,并采用Rev Man 5.3软件进行Meta分析。结果：共纳入147个RCTs,Meta分析结果显示：（1）左旋氨氯地平联合ACEI在SBP降低值[SMD=0.92,95% CI（0.79,1.04）,P < 0.000 01],DBP降低值[SMD=0.87,95% CI（0.72,1.03）,P < 0.000 01]和总有效率[RR=1.23,95% CI（1.20,1.26）,P < 0.000 01]方面均优于对照组,差异具有统计学意义;（2）左旋氨氯地平联合ARB在SBP降低值[SMD=1.29,95% CI（1.10,1.48）,P < 0.000 01],DBP降低值[SMD=0.94,95% CI（0.79,1.09）,P < 0.000 01]和总有效率[RR=1.22,95% CI（1.20,1.25）,P < 0.000 01]方面均优于对照组,差异具有统计学意义;（3）左旋氨氯地平联合β受体拮抗剂在SBP降低值[SMD=0.88,95% CI（0.39,1.36）,P=0.000 5],DBP降低值[SMD=0.80,95% CI（0.35,1.25）,P=0.000 5]和总有效率[RR=1.18,95% CI（1.12,1.23）,P < 0.000 01]方面优于对照组,差异具有统计学意义;（4）左旋氨氯地平联合利尿剂在SBP降低值[SMD=1.34,95% CI（0.78,1.90）,P < 0.000 01],DBP降低值[SMD=0.72,95% CI（0.20,1.24）,P=0.007]方面优于对照组,差异具有统计学意义。结论：基于现有临床证据,左旋氨氯地平联合一线降压药降压效果优于单一用药方案。     

Phloroglucinol averts isoprenaline hydrochloride induced myocardial infarction in rats

Myocardial infarction (MI) is indicated by the symptoms like sharp chest pain, sweating, palpitations, and nervousness finally leading to heart attack. MI occurs mainly due to the risk factors like smoking, elevated blood pressure, diabetes, hypercholesterolemia, obesity, decreased HDL level, elevated LDL level, hyperlipoproteinemia and aging consequently leads to demandable coronary blood supply, oxidative stress, and acute necrosis of the myocardium. Cardioprotective potential of the phloroglucinol (PG) was assessed by treating isoprenaline hydrochloride (ISO; 85 mg/kg b.w., s.c.) induced MI model in rats. Pretreatment with PG in a dose of 30 mg/kg was done for 28 days and followed by ISO (for MI induction) on 29th and 30th days, exhibited decline in the abnormalities in the ECG patterns, cardiac marker enzymes, enzymic and nonenzymic antioxidants, lipid peroxidation, lipid profiles, and histopathological investigations compared to isoprenaline alone treated group. On the whole, the present investigations elucidate the significance of PG in alleviating the pathological process and appreciably prevent the induction of MI in experimental rats.     

Structure-based cleavage mechanism of Thermus thermophilus Argonaute DNA guide strand-mediated DNA target cleavage

We report on crystal structures of ternary Thermus thermophilus Argonaute (TtAgo) complexes with 5′-phosphorylated guide DNA and a series of DNA targets. These ternary complex structures of cleavage-incompatible, cleavage-compatible, and postcleavage states solved at improved resolution up to 2.2 Å have provided molecular insights into the orchestrated positioning of catalytic residues, a pair of Mg²⁺ cations, and the putative water nucleophile positioned for in-line attack on the cleavable phosphate for TtAgo-mediated target cleavage by a RNase H-type mechanism. In addition, these ternary complex structures have provided insights into protein and DNA conformational changes that facilitate transition between cleavage-incompatible and cleavage-compatible states, including the role of a Glu finger in generating a cleavage-competent catalytic Asp-Glu-Asp-Asp tetrad. Following cleavage, the seed segment forms a stable duplex with the complementary segment of the target strand.Argonaute (Ago) proteins, critical components of the RNA-induced silencing complex, play a key role in guide strand-mediated target RNA recognition, cleavage, and product release (reviewed in refs. 1–3). Ago proteins adopt a bilobal scaffold composed of an amino terminal PAZ-containing lobe (N and PAZ domains), a carboxyl-terminal PIWI-containing lobe (Mid and PIWI domains), and connecting linkers L1 and L2. Ago proteins bind guide strands whose 5′-phosphorylated and 3′-hydroxyl ends are anchored within Mid and PAZ pockets, respectively (4–7), with the anchored guide strand then serving as a template for pairing with the target strand (8, 9). The cleavage activity of Ago resides in the RNase H fold adopted by the PIWI domain (10, 11), whereby the enzyme’s Asp-Asp-Asp/His catalytic triad (12–15) initially processes loaded double-stranded siRNAs by cleaving the passenger strand and subsequently processes guide-target RNA duplexes by cleaving the target strand (reviewed in refs. 16–18). Such Mg²⁺ cation-mediated endonucleolytic cleavage of the target RNA strand (19, 20) resulting in 3′-OH and 5′-phosphate ends (21) requires Watson–Crick pairing of the guide and target strands spanning the seed segment (positions 2–2′ to 8–8′) and the cleavage site (10′–11′ step on the target strand) (9). Insights into target RNA recognition and cleavage have emerged from structural (9), chemical (22), and biophysical (23) experiments.Notably, bacterial and archaeal Ago proteins have recently been shown to preferentially bind 5′-phosphoryated guide DNA (14, 15) and use an activated water molecule as the nucleophile (reviewed in ref. 24) to cleave both RNA and DNA target strands (9). Structural studies have been undertaken on bacterial and archaeal Ago proteins in the free state (10, 15) and bound to a 5′-phosphorylated guide DNA strand (4) and added target RNA strand (8, 9). The structural studies of Thermus thermophilus Ago (TtAgo) ternary complexes have provided insights into the nucleation, propagation, and cleavage steps of target RNA silencing in a bacterial system (9). These studies have highlighted the conformational transitions on proceeding from Ago in the free state to the binary complex (4) to the ternary complexes (8, 9) and have emphasized the requirement for a precisely aligned Asp-Asp-Asp triad and a pair of Mg²⁺ cations for cleavage chemistry (9), typical of RNase H fold-mediated enzymes (24, 25). Structural studies have also been extended to binary complexes of both human (5, 6) and yeast (7) Agos bound to 5′-phosphorylated guide RNA strands.Despite these singular advances in the structural biology of RNA silencing, further progress was hampered by the modest resolution (2.8- to 3.0-Å resolution) of TtAgo ternary complexes with guide DNA (4) and added target RNAs (8, 9). This precluded identification of water molecules coordinated with the pair of Mg²⁺ cations, including the key water that acts as a nucleophile and targets the cleavable phosphate between positions 10′-11′ on the target strand. We have now extended our research to TtAgo ternary complexes with guide DNA and target DNA strands, which has permitted us to grow crystals of ternary complexes that diffract to higher (2.2–2.3 Å) resolution in the cleavage-incompatible, cleavage-compatible, and postcleavage steps. These high-resolution structures of TtAgo ternary complexes provide snapshots of distinct key steps in the catalytic cleavage pathway, opening opportunities for experimental probing into DNA target cleavage as a defense mechanism against plasmids and possibly other mobile elements (26, 27).