不同HbA1c水平糖尿病患者白内障术后的临床分析

目的:探讨糖化血红蛋白(HbA1c)水平与糖尿病白内障患者术后1mo视力、眼压、并发症、黄斑中心凹厚度的关系。方法:回顾性分析2018-01/12我院糖尿病白内障患者56例66眼,根据术前HbA1c水平将患者分为A组(正常HbA1c组,HbA1c≤6.0%)和B组(高HbA1c组,6.0%<HbA1c≤8.0%)。所有患者均行白内障超声乳化术。分析两组患者手术前后视力、眼压、黄斑中心凹厚度的变化,以及术后并发症。结果:两组患者术后BCVA均有明显提高。两组患者术后1mo眼压比较无差异(P>0.05)。术后并发症主要有前房反应、一过性眼压增高、角膜水肿、黄斑水肿,A组发生率为56%,B组为88%,B组并发症较A组高(P=0.029)。B组黄斑中心凹厚度高于A组,且两组黄斑中心凹厚度术后高于术前,B组术后增加厚度比A组更明显(P<0.05)。结论:高HbA1c组与正常HbA1c组相比,术后并发症多,黄斑中心凹厚度高,术后视力差。因此,糖尿病患者术前HbA1c水平可能与白内障术后的并发症、黄斑中心凹厚度有关。

硝酸根对颗粒状铁降解三氯乙烯的影响(英文)

为研究硝酸根对颗粒状铁降解三氯乙烯的影响,进行了柱实验和相应的反应铁腐蚀电位测定。在硝酸根离子存在条件下,铁的腐蚀电位相应升高,系统条件也因之发生变化,导致钝性的铁氧化物在铁表面生成。因而,三氯乙烯和硝酸根离子降解速率明显减小, 并且降解速率减小的程度与硝酸根离子的浓度成比例。当污染液流过反应柱时,硝酸根离子与铁反应, 被还原为氨根离子。该反应造成硝酸根离子的浓度梯度,使钝化区在柱中上移,从而影响了三氯乙烯的降解曲线。与三氯乙烯单独与铁反应相比,当含4 7 mg/L硝酸根的三氯乙烯溶液流经反应柱170 孔隙体积后,降解50% 三氯乙烯所需的时间(t50) 从小于4 h增加到大于10 h;而当三氯乙烯溶液中加入100 mg/L硝酸根离子,仅17 孔隙体积溶液流经反应柱后,三氯乙烯降解t50就已大于14 h。研究结果表明,由于硝酸根离子对铁的腐蚀电位和铁表面氧化膜的不利作用,在处理靶污染物为高浓度硝酸根离子和三氯乙烯共同污染的地下水时,铁渗透反应隔栅不是最佳选择。如果靶污染物中硝酸根离子浓度比较低,则在设计铁隔栅时应考虑到硝酸根离子造成的不利因素,相应增加铁墙的厚度,从而确保三氯乙烯的降解效果。

Crystal structure of the swine-origin A (H1N1)- 2009 influenza A virus hemagglutinin (HA) reveals similar antigenicity to that of the 1918 pandemic virus

Influenza virus is the causative agent of the seasonal and occasional pandemic flu.The current H1N1 influenza pandemic,announced by the WHO in June 2009,is highly contagious and responsible for global economic losses and fatalities.Although the H1N1 gene segments have three origins in terms of host species,the virus has been named swine-origin influenza virus(S-OIV)due to a predominant swine origin.2009 S-OIV has been shown to highly resemble the 1918 pandemic virus in many aspects.Hemagglutinin is responsible for the host range and receptor binding of the virus and is therefore a primary indicator for the potential of infection.Primary sequence analysis of the 2009 S-OIV hemagglutinin(HA)reveals its closest relationship to that of the 1918 pandemic influenza virus,however,analysis at the structural level is necessary to critically assess the functional significance.In this report,we report the crystal structure of soluble hemagglutinin H1(09H1)at 2.9Å,illustrating that the 09H1 is very similar to the 1918 pandemic HA(18H1)in overall structure and the structural modules,including the five defined antiboby(Ab)-binding epitopes.Our results provide an explanation as to why sera from the survivors of the 1918 pandemics can neutralize the 2009 S-OIV,and people born around the 1918 are resistant to the current pandemic,yet younger generations are more susceptible to the 2009 pandemic.

Cross-reactivity of eight SARS-CoV-2 variants rationally predicts immunogenicity clustering in sarbecoviruses

A steep rise in Omicron reinfection cases suggests that this variant has increased immune evasion ability.To evaluate its antigenicity relationship with other variants,antisera from guinea pigs immunized with spike protein of SARS-CoV-2 variants of concern(VOCs)and variants of interest(VOIs)were cross-tested against pseudotyped variants.The neutralization activity against Omicron was markedly reduced when other VOCs or VOIs were used as immunogens,and Omicron(BA.1)-elicited sera did not efficiently neutralize the other variants.However,a Beta or Omicron booster,when administered as the 4th dose 3-months after the 3rd dose of any of the variants,could elicit broad neutralizing antibodies against all of the current variants including Omicron BA.1.Further analysis with 280 available antigen–antibody structures and quantification of immune escape from 715 reported neutralizing antibodies provide explanations for the observed differential immunogenicity.Three distinct clades predicted using an in silico algorithm for clustering of sarbecoviruses based on immune escape provide key information for rational design of vaccines.

An octamer of enolase from Streptococcus suis

Enolase is a conserved cytoplasmic metalloenzyme existing universally in both eukaryotic and prokaryotic cells.The enzyme can also locate on the cell surface and bind to plasminogen,via which contributing to the mucosal surface localization of the bacterial pathogens and assisting the invasion into the host cells.The functions of the eukaryotic enzymes on the cell surface expression(including T cells,B cells,neutrophils,monocytoes,neuronal cells and epithelial cells)are not known.Streptococcus suis serotype 2(S.suis 2,SS2)is an important zoonotic pathogen which has recently caused two large-scale outbreaks in southern China with severe streptococcal toxic shock syndrome(STSS)never seen before in human sufferers.We recently identified the SS2 enolase as an important protective antigen which could protect mice from fatal S.suis 2 infection.In this study,a 2.4-angstrom structure of the SS2 enolase is solved,revealing an octameric arrangement in the crystal.We further demonstrated that the enzyme exists exclusively as an octamer in solution via a sedimentation assay.These results indicate that the octamer is the biological unit of SS2 enolase at least in vitro and most likely in vivo as well.This is,to our knowledge,the first comprehensive characterization of the SS2 enolase octamer both structurally and biophysically,and the second octamer enolase structure in addition to that of Streptococcus pneumoniae.We also investigated the plasminogen binding property of the SS2 enzyme.

到民间去——当代民艺展览的文化价值

在“留住乡愁”成为新时期城镇建设、乡村振兴建设重要标准的背景下,2022年中国国家博物馆举办了“到民间去——潘鲁生民艺展”。该展览体现了潘鲁生一贯的学术主张和学术思想,体现了宽广的时空范围,在展览的空间布局上具有隐喻化设计的特征。本次展览还具有重构乡愁记忆、文化认同、创新民艺的表达形式、展史和存史等文化价值,对今后的民艺展览具有重要的借鉴意义。

Highly oxidation-resistant Ti-Mo alloy with two-scale network Ti_(5)Si_(3)reinforcement

There is keen interest in using Ti alloys as lightweight structural materials for aerospace and automotive industries.However,a long-standing problem for these materials is their poor oxidation resistance.Herein,we designed and fabricated a Ti_(5)Si_(3) reinforced Ti-4(wt.%)Mo composite with two-scale network architecture by low energy milling and spark plasma sintering.It displays superior oxidation resistance at 800°C owing to the in-situ formation of a multi-component surface layer.This oxide layer has a dense grain size gradient structure that consists of an outer TiO_(2)layer and an inner SiO_(2)-padding-TiO_(2) layer,which has remarkable oxidation resistance and thermal stability.Furthermore,it was revealed that the hitherto unknown interaction between Ti_(5)Si_(3) reinforcement and nitrogen during oxidation would contribute to the formation of a TiN nano-twin interface layer,which accommodates the thermal mismatch strain between the oxide layer and matrix.This,along with high adhesion,confers excellent thermal cycling life with no cracking or spallation during long-term oxidation.In this regard,the secure operating temperature of this new composite can be increased to 800°C,which provides a design pathway for a new family of Ti matrix composites for high-temperature applications.

Structural and functional insights into MCR-2 mediated colistin resistance

Dear Editor,The spread of antibiotic resistance genes among bacteria is a serious and growing threat to global health (Peleg and Hoopet,2010).One emerging case is transferable genes found in bacteria-encoding enzymes resistant to colistin.Colistin is a cationic polypeptide antibiotic with broadspectrum activity against Gram-negative bacteria through interactions with the lipid A moiety of bacterial lipopoly-saccharide(LPS),subsequently destroying the cell envelope.During late 2015,a plasmid-mediated gene,mcr-1,was first reported from Escherichia coli(E.coli)in China to confer resistance to colistin(Liu et a1.,2016),and detected world-wide soon afterwards(Gao et a1.,2016;Hu et a1.,2016).