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Wrist circumference: A new marker for insulin resistance in African women with polycystic ovary syndrome 预览
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作者 Chantal Anifa Amisi Massimo Ciccozzi Paolo Pozzilli 《世界糖尿病杂志:英文版(电子版)》 2020年第2期42-51,共10页
BACKGROUND Insulin resistance(IR)is the main complication found in 35%-80%of women with polycystic ovary syndrome(PCOS).However,there is no definite consensus regarding which marker to use for its assessment in PCOS w... BACKGROUND Insulin resistance(IR)is the main complication found in 35%-80%of women with polycystic ovary syndrome(PCOS).However,there is no definite consensus regarding which marker to use for its assessment in PCOS women.Research has shown that hyperinsulinemia is correlated with increased bone mass.Given that most women with PCOS are insulin resistant,which is independent from body fat and characterized by hyperinsulinemia,it could be hypothesized that there would be an increased bone mass in the patient as a result.Subsequently,increased bone mass could be measured using the wrist circumference method.AIM To assess the wrist circumference as an easy-to-detect marker of IR in Congolese women with PCOS.METHODS Seventy-two Congolese women with PCOS and seventy-one controls from the same ethnic group,were enrolled in the study(mean age 24.33±5.36 years).Fasting biochemical parameters,and the Homeostasis Model Assessment of insulin resistance(HOMA-IR)and body composition were evaluated.The nondominant wrist circumference was measured manually,as was the waist circumference(WC),hip circumference,height and weight.Calculated measures included evaluation of body mass index(BMI),Waist-to-Height(WHtR)and Waist-to-hip ratio(WHR).In addition,body composition was assessed by Bioelectrical Impedance Analysis using a body fat analyzer.RESULTS The non-dominant wrist circumference was more closely correlated with HOMAIR(r=0.346;P=0.003)and was the best anthropometrical marker correlated with IR(P=0.011)compared with other anthropometrical markers in women with PCOS:Dominant Wrist Circumference(r=0.315;P=0.007),Waist Circumference(WC)(r=0.259;P=0.028),BMI(r=0.285;P=0.016),WHR(r=0.216;P=0,068)and WHtR(r=0.263;P=0.027).The diagnostic accuracy of the non-dominant wrist circumference for the presence or absence of IR using Receiver-operating characteristic(ROC)curve analysis showed that the area under the ROC curve was 0.72.A cutoff value for the non-dominant wrist circumference of 16.3 cm was found to be the best predictor of IR 展开更多
关键词 Wrist circumference Insulin resistance Polycystic ovary syndrome Congolese women Sub-Saharan African women Marker of insulin resistance Homeostasis Model Assessment of insulin resistance Easy-to-detect marker
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Association between the Phenotypes and Genotypes of Antimicrobial Resistance in Haemophilus parasuis Isolates from Swine in Quang Binh and Thua Thien Hue Provinces, Vietnam 预览
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作者 Chao Nguyen Van Lijun Zhang +4 位作者 Tam Vu Thi Thanh Hung Pham Hoang Son Tuan Tran Ngoc Qi Huang Rui Zhou 《工程(英文)》 2020年第1期40-48,共9页
Haemophilus parasuis (H. parasuis) is one of the bacterial pathogens of great concern as it causes huge economic losses to the swine industry worldwide. One of the reasons why the control of H. parasuis has failed is ... Haemophilus parasuis (H. parasuis) is one of the bacterial pathogens of great concern as it causes huge economic losses to the swine industry worldwide. One of the reasons why the control of H. parasuis has failed is the increase in antimicrobial resistance (AMR). The country of Vietnam has the second-largest pig production in Asia. However, there is still a lack of data about the AMR prevalence of H. parasuis in Vietnam.The purpose of this study is to investigate the prevalence of AMR and analyze the association between AMR and AMR genes (ARGs). The H. parasuis strains used in this research were isolated from swine in the Quang Binh and Thua Thien Hue Provinces, Central Vietnam, as reported in our previous study. All of the strains were tested for AMR against 25 antibacterial agents using the broth microdilution method and for the presence of ARGs using the polymerase chain reaction (PCR) method. The tested strains were shown to have a high frequency of resistance to trimethoprim/sulfamethoxazole (94.6%), followed by resistance to colistin, chloramphenicol, gentamicin, penicillin, lincomycin, and amoxicillin. The most prevalent ARGs in these strains were blaTEM-1 (94.6%), int (76.8%), gyrA (58.9%), and rmtD (50.0%). Cefuroxime, chloramphenicol, and tobramycin resistances were strongly correlated with the presence of the ARGs blaROB-1 (odds ratio (OR) = 26.3, 95% confidence interval (CI) 2.7–255.7, p = 0.002), catl (OR = 25.1, 95% CI 2.4–258.9, p = 0.004), and strB (OR = 23.5, 95% CI 2.6–212.6, p = 0.001), respectively.This study reveals for the first time the current situation of H. parasuis AMR in Central Vietnam, which is helpful for the clinical control of this disease, as well as for the development of policies and clinical practice guidelines to reduce AMR in swine production in Central Vietnam. 展开更多
关键词 Haemophilus parasuis Antimicrobial resistance Antimicrobial resistance gene VIETNAM
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热阻仿真在陶瓷封装电阻计算中的应用
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作者 崔朝探 刘林杰 李玮 《半导体技术》 CAS 北大核心 2020年第3期224-228,共5页
随着半导体封装器件的不断发展,工作电流不断增加,对陶瓷封装的电性能提出了更高要求,而导通电阻是衡量其电性能最重要的参数之一,会影响电路的稳定性和功耗波动。提出了一种陶瓷封装中导通电阻仿真求解的新方法,利用ANSYS软件热阻仿真... 随着半导体封装器件的不断发展,工作电流不断增加,对陶瓷封装的电性能提出了更高要求,而导通电阻是衡量其电性能最重要的参数之一,会影响电路的稳定性和功耗波动。提出了一种陶瓷封装中导通电阻仿真求解的新方法,利用ANSYS软件热阻仿真模型等效求解电阻的方式,实现导通电阻值的精确计算。阐述了热阻模型与电阻模型的等效机理,对比了传统估值法与仿真求解法的计算结果,结果表明,仿真求解法得到的电阻值与实测电阻值更为接近,误差小于5%,而传统估值法误差最高可达30%。仿真求解法计算时间大大缩短,效率更高,还可观察线路的连通关系,错误率远低于传统估值算法。该方法适用于陶瓷封装中不同类型和任意结构的阻值计算,通用性强。 展开更多
关键词 陶瓷封装 导通电阻 热阻仿真模型 等效机理 通用性
新型流化除雾器除雾性能实验研究
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作者 张成刚 陈旺生 +2 位作者 朱能天 涂阳哲 韩军 《烧结球团》 北大核心 2020年第1期67-72,共6页
针对目前除雾器存在的除雾效率不高、易堵塞、成本高等问题,提出一种新型的流化除雾器,其具有高效、低阻、防堵塞等优点。探讨了流化除雾器的除雾原理,并研究了流化除雾器的除雾性能及其影响因素。结果表明:流化除雾器除雾机理主要为惯... 针对目前除雾器存在的除雾效率不高、易堵塞、成本高等问题,提出一种新型的流化除雾器,其具有高效、低阻、防堵塞等优点。探讨了流化除雾器的除雾原理,并研究了流化除雾器的除雾性能及其影响因素。结果表明:流化除雾器除雾机理主要为惯性碰撞、拦截;除雾器阻力随着流化风速、除雾介质堆积厚度和表观密度的增大而增大,当除雾介质粒径为30 mm,堆积厚度为16 cm,进口雾滴质量浓度为90 g/m^3,流化风速由5.7 m/s增大至7.5 m/s时,排放质量浓度由4.17 mg/m^3增大至41.94 mg/m^3,除雾效率均高达99.95%以上,阻力均在210 Pa左右,表明流化除雾器具有良好的除雾性能,且由于除雾介质处于流化状态,因此可有效防止除雾器堵塞。 展开更多
关键词 除雾器 除雾机理 除雾效率 排放质量浓度 阻力
Genetic progress in stem lodging resistance of the dominant wheat cultivars adapted to Yellow-Huai River Valleys Winter Wheat Zone in China since 1964 预览
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作者 ZHANG Hong-jun LI Teng +9 位作者 LIU Hong-wei MAI Chun-yan YU Guang-jun LI Hui-li YU Li-qiang MENG Ling-zhi JIAN Da-wei YANG Li LI Hong-jie ZHOU Yang 《农业科学学报:英文版》 SCIE CAS CSCD 2020年第2期438-448,共11页
Analysis of genetic progress for lodging-related traits provides important information for further improvement of lodging resistance.Forty winter wheat cultivars widely grown in the Yellow-Huai River Valleys Winter Wh... Analysis of genetic progress for lodging-related traits provides important information for further improvement of lodging resistance.Forty winter wheat cultivars widely grown in the Yellow-Huai River Valleys Winter Wheat Zone(YHWZ)of China during the period of 1964–2015 were evaluated for several lodging-related traits in three cropping seasons.Plant height,height at center of gravity,length of the basal second internode,and lodging index decreased significantly in this period,and the average annual genetic gains for these traits were–0.50 cm or–0.62%,–0.27 cm or–0.60%,–0.06 cm or–0.63%,and–0.01 or–0.94%,respectively.Different from other traits,stem strength showed a significant increasing trend with the breeding period,and the annual genetic gains were 0.03 N or 0.05%.Correlation analysis showed that lodging index was positively correlated with plant height,height at center of gravity,and length of the basal second internode,but negatively correlated with stem strength.Meanwhile,significantly positive correlations were observed between plant height,height at center of gravity,and length of the basal first and second internodes.By comparison with the wild types,dwarfing genes had significant effects on all lodging-related traits studied except for length of the basal first internode and stem strength.Principle component analysis demonstrated that plant height and stem strength were the most important factors influencing lodging resistance.Clustering analysis based on the first two principle components further indicated the targets of wheat lodging-resistant breeding have changed from reducing plant height to strengthening stem strength over the breeding periods.This study indicates that the increase of stem strength is vital to improve lodging resistance in this region under the high-yielding condition when plant height is in an optimal range. 展开更多
关键词 Triticum aestivum lodging resistance stem strength genetic progress Yellow-Huai River Valleys Winter Wheat Zone
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Screening of drought resistance indices and evaluation of drought resistance in cotton(Gossypium hirsutum L.) 预览
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作者 ZOU Jie HU Wei +3 位作者 LI Yu-xia HE Jia-qi ZHU Hong-hai ZHOU Zhi-guo 《农业科学学报:英文版》 SCIE CAS CSCD 2020年第2期495-508,共14页
Sixteen cotton cultivars widely planted in China were sowed under five different drought concentrations(0,2.5,5,7.5,and 10%)using PEG6000 to screen the indices of drought resistance identification and explore the drou... Sixteen cotton cultivars widely planted in China were sowed under five different drought concentrations(0,2.5,5,7.5,and 10%)using PEG6000 to screen the indices of drought resistance identification and explore the drought resistance of different cotton cultivars.Eighteen physiological indices including root,stem,and leaf water contents(RWC,SWC,and LWC),net photosynthetic rate(Pn),the maximum photochemical quantum yield(Fv/Fm),the actual photochemical quantum yield(ΦPSII),non-photochemical quenching coefficient(NPQ),leaf water potential(LWP),osmotic potential(Ψs),leaf relative conductivity(REC),leaf proline content(Pro),leaf and root soluble protein contents(LSPC and RSPC),leaf and root malondialdehyde(MDA)contents(LMDA and RMDA),root superoxide dismutase,peroxidase,and catalase activities(RSOD,RPOD,and RCAT)were measured.Results indicated the 18 physiological indices can be converted into five or six independent comprehensive indices by principal component analysis,and nine typical indices(Fv/Fm,SWC,LWP,Pro,LMDA,RSPC,RMDA,RSOD,and RCAT)screened out by a stepwise regression method could be utilized to evaluate the drought resistance.Moreover,the 16 cotton cultivars were divided into four types:drought sensitive,drought weak sensitive,moderate drought resistant,and drought resistant types.The resistance ability of two selected cotton cultivars(drought resistant cultivar,Dexiamian 1;drought sensitive cultivar,Yuzaomian 9110)with contrasting drought sensitivities were further verified by pot experiment.Results showed that the responses of final cotton biomass,yield,and yield composition to drought were significantly different between the two cultivars.In conclusion,drought resistant cultivar Dexiamian 1 and drought sensitive cultivar Yuzaomian 9110 were screened through hydroponics experiment,which can be used as ideal experimental materials to study the mechanism of different cotton cultivars with contrasting drought sensitivities in response to drought stress. 展开更多
关键词 cotton(Gossypium hirsutum L.) drought resistance screening indices principal component analysis cultivar verification
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Effects of gender-affirming hormone therapy on insulin resistance and body composition in transgender individuals: A systematic review 预览
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作者 Cassandra Spanos Ingrid Bretherton +1 位作者 Jeffrey D Zajac Ada S Cheung 《世界糖尿病杂志:英文版(电子版)》 2020年第3期66-77,共12页
BACKGROUND Transgender individuals receiving masculinising or feminising gender-affirming hormone therapy with testosterone or estradiol respectively,are at increased risk of adverse cardiovascular outcomes,including ... BACKGROUND Transgender individuals receiving masculinising or feminising gender-affirming hormone therapy with testosterone or estradiol respectively,are at increased risk of adverse cardiovascular outcomes,including myocardial infarction and stroke.This may be related to the effects of testosterone or estradiol therapy on body composition,fat distribution,and insulin resistance but the effect of genderaffirming hormone therapy on these cardiovascular risk factors has not been extensively examined.AIM To evaluate the impact of gender-affirming hormone therapy on body composition and insulin resistance in transgender individuals,to guide clinicians in minimising cardiovascular risk.METHODS We performed a review of the literature based on PRISMA guidelines.MEDLINE,Embase and PsycINFO databases were searched for studies examining body composition,insulin resistance or body fat distribution in transgender individuals aged over 18 years on established gender-affirming hormone therapy.Studies were selected for full-text analysis if they investigated transgender individuals on any type of gender-affirming hormone therapy and reported effects on lean mass,fat mass or insulin resistance.RESULTS The search strategy identified 221 studies.After exclusion of studies that did not meet inclusion criteria,26 were included(2 cross-sectional,21 prospectiveuncontrolled and 3 prospective-controlled).Evidence in transgender men suggests that testosterone therapy increases lean mass,decreases fat mass and has no impact on insulin resistance.Evidence in transgender women suggests that feminising hormone therapy(estradiol,with or without anti-androgen agents)decreases lean mass,increases fat mass,and may worsen insulin resistance.Changes to body composition were consistent across almost all studies:Transgender men on testosterone gained lean mass and lost fat mass,and transgender women on oestrogen experienced the reverse.No study directly contradicted these trends,though several small studies of short duration reported no changes.Resu 展开更多
关键词 Transgender persons Insulin resistance Body composition Gender dysphoria Metabolic syndrome
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Prevalence and interrelationships of foot ulcer, risk-factors and antibiotic resistance in foot ulcers in diabetic populations: A systematic review and meta-analysis 预览
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作者 Mohammad Zubair 《世界糖尿病杂志:英文版(电子版)》 2020年第3期78-89,共12页
BACKGROUND Diabetic foot ulceration(DFU)is the prime health concern globally.It accounts for the major burden related to disease mortality and morbidity and economic cost.The timely and early recognition of the DFU ca... BACKGROUND Diabetic foot ulceration(DFU)is the prime health concern globally.It accounts for the major burden related to disease mortality and morbidity and economic cost.The timely and early recognition of the DFU can help present its occurrence and improve clinical outcomes.AIM To evaluate interrelationships between foot ulcers,risk factors,and antibiotic resistance among diabetic patients having ulcers in their foot.METHODS The databases such as PubMed,ERIC,Medline,and Google Scholar were extensively used for the extraction of studies.The selected studies were published within the time-period of 2014-2018.Ten studies were selected,which were found to be completely relevant to the current study.RESULTS The prevalence of diabetic foot ulcers among the population was evaluated,and the associated risk factors with its prevalence.Moreover,few studies also reported on the bacteria that are found to be most prevailing among diabetic patients.A narrative discussion was drawn through this analysis,which was used to highlight the specific area of research through selected studies,extraction of the significant information that matched with the topic of research,and analysis of problem through the findings of the selected articles.The results helped in assessing significant knowledge regarding the risk factors of diabetic foot ulcers and the role of antimicrobial resistant in its treatment.CONCLUSION The gram-negative bacteria were found to be the most common reason for diabetic foot ulcers.The study only included 10 studies that are not sufficient to produce generalized results,and no information was reported on the tests required to analyze antimicrobial susceptibility that can guide clinicians to propose better and sound treatment plans.It is evident that most study results depicted that the most common risk factors were found to be hypertension and neuropathy. 展开更多
关键词 AMPUTATION Diabetes mellitus Drug resistance Foot ulcer Gram-negative bacteria
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家蚕抗性品系NC99R抗BmNPV作用机制分析
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作者 董战旗 雷雪蛟 +4 位作者 秦琪 张新铃 唐亮 石美宁 潘敏慧 《生物工程学报》 CAS CSCD 北大核心 2020年第1期100-108,共9页
家蚕Bombyxmori是具有重要经济价值的鳞翅目模式昆虫,由家蚕核型多角体病毒(Bombyxmori nucleopolyhedrovirus,BmNPV)引起的家蚕血液型脓病每年给我国蚕桑产业造成巨大的经济损失。文中拟通过鉴定目前存在的家蚕抗病毒品系NC99R抗性特征... 家蚕Bombyxmori是具有重要经济价值的鳞翅目模式昆虫,由家蚕核型多角体病毒(Bombyxmori nucleopolyhedrovirus,BmNPV)引起的家蚕血液型脓病每年给我国蚕桑产业造成巨大的经济损失。文中拟通过鉴定目前存在的家蚕抗病毒品系NC99R抗性特征,初步解析其抗BmNPV机制,以期为家蚕抗病品系分子机制解析提供一定参考。将对照组大造(Dazao,DZ)品系和实验组NC99R抗性品系家蚕幼虫分别定量添食BmNPV包涵体(Occlusion bodies,OB),计算DZ和NC99R品系对BmNPV的半致死剂量(Median lethal dose,LD50),结果显示DZ品系半致死剂量为1.2×10^5多角体/头,抗性品系NC99R的半致死剂量为1.8×106多角体/头,抗性水平相比对照组提高15倍左右。进一步统计分析DZ和NC99R品系口服感染1×10^6多角体/头和体腔注射1×10^6粒子/头出芽型病毒粒子(Budded virus,BV)后的死亡率,结果显示DZ品系死亡高峰集中在第4–6天,NC99R抗性品系死亡高峰集中在第6–8天,与对照相比延迟1–2 d。通过RT-PCR分析BmNPV DNA拷贝数,显示DZ在口服感染和体腔注射后BmNPV基因组都快速增殖,抗性品系NC99R BmNPV DNA拷贝数缓慢增加。HE染色分析显示DZ和NC99R品系在口服感染前期没有显著差异,感染到96 h,DZ中肠细胞核变大,成脱落趋势;而抗性品系NC99R,细胞核膨大,但细胞排列仍较整齐。RT-PCR分析病毒不同时期基因表达显示抗性品系NC99R在口服感染和体腔注射24h后早期基因ie-1开始下调表达,其他时期基因随即下调表达;最后维持在较低表达水平或消失。 展开更多
关键词 家蚕 家蚕核型多角体病毒 抗性 NC99R
杨树对落叶松-杨栅锈菌抗性生理机制研究 预览
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作者 刘莉丽 陈祖静 +1 位作者 曹支敏 费昭雪 《西北林学院学报》 CSCD 北大核心 2020年第1期171-176,共6页
采用叶盘法对供试寄主杨树进行落叶松-杨栅锈菌夏孢子人工接种处理,研究了杨树对落叶松-杨栅锈菌抗病性的生理机制。结果表明,接种病原菌后1~8 d,6种杨树的PAL、PPO、几丁质酶和β-N-乙酰氨基葡萄糖苷酶活性均升高,且酶活性的变化与树... 采用叶盘法对供试寄主杨树进行落叶松-杨栅锈菌夏孢子人工接种处理,研究了杨树对落叶松-杨栅锈菌抗病性的生理机制。结果表明,接种病原菌后1~8 d,6种杨树的PAL、PPO、几丁质酶和β-N-乙酰氨基葡萄糖苷酶活性均升高,且酶活性的变化与树种的抗性表现了较好的正相关。抗病较强的美黑01和中绥12号接种病原菌后,PAL、PPO、几丁质酶和β-N-乙酰氨基葡萄糖苷酶活性不仅升高幅度大,而且这些酶活性绝对值也明显高于抗病性较弱(或感病)树种中林美荷、69杨等。同时抗病较强的树种中这些酶高活维持的时间也较长。这些变化促进了抗病物质的形成和积累,从而表现出抗病性。从几种酶活性测定的总体结果来看,PAL和几丁质酶在受侵各杨树种(品种)体内的活性增幅较其他酶类明显较高,故这几种酶可作为杨树抗叶锈病的生理指标。 展开更多
关键词 杨树 落叶松-杨栅锈病 抗病性
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Towards the diffusion source cost reduction for NdFeB grain boundary diffusion process
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作者 H.X.Zeng Z.W.Liu +2 位作者 J.S.Zhang X.F.Liao H.Y.Yu 《材料科学技术:英文版》 SCIE EI CAS CSCD 2020年第1期50-54,共5页
Aiming at improving the performance/cost ratio in grain boundary diffusion process(GBDP),the critical RE containing Pr-Al-Cu alloy,less expensive RE containing La-Al-Cu alloy and non-RE Al-Cu alloy were employed as th... Aiming at improving the performance/cost ratio in grain boundary diffusion process(GBDP),the critical RE containing Pr-Al-Cu alloy,less expensive RE containing La-Al-Cu alloy and non-RE Al-Cu alloy were employed as the diffusion sources.The preliminary results show that the coercivity was successfully enhanced from 1000 kA/m to 1695,1156 and 1125 kA/m by Pr70Al20Cu10,La70Al20Cu10 and Al75Cu25(at.%) alloys diffusion,respectively,due to the formation of(Nd,Pr)-Fe-B,La2 O3 and c-Nd2 O3 phases respectively,after diffusion.It is also found that the corrosion resistance can be improved by Al-Cu diffusion due to the positive effects of Al and Cu elements in grain boundary.The present results demonstrated the various coercivity enhancement mechanisms for the GBDP based on different diffusion sources,and provided feasible solutions for cost reduction of GBDP and NdFeB production by saving RE resource. 展开更多
关键词 Grain boundary diffusion Cost reduction COERCIVITY Microstructure Corrosion resistance
Complement activation in obesity,insulin resistance,and type 2 diabetes mellitus 预览
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作者 Kyumin Shim Rayhana Begum +1 位作者 Catherine Yang Hongbin Wang 《世界糖尿病杂志:英文版(电子版)》 2020年第1期1-12,共12页
Amplified inflammatory reaction has been observed to be involved in cardiometabolic diseases such as obesity,insulin resistance,diabetes,dyslipidemia,and atherosclerosis.The complement system was originally viewed as ... Amplified inflammatory reaction has been observed to be involved in cardiometabolic diseases such as obesity,insulin resistance,diabetes,dyslipidemia,and atherosclerosis.The complement system was originally viewed as a supportive first line of defense against microbial invaders,and research over the past decade has come to appreciate that the functions of the complement system extend beyond the defense and elimination of microbes,involving in such diverse processes as clearance of the immune complexes,complementing T and B cell immune functions,tissue regeneration,and metabolism.The focus of this review is to summarize the role of the activation of complement system and the initiation and progression of metabolic disorders including obesity,insulin resistance and diabetes mellitus.In addition,we briefly describe the interaction of the activation of the complement system with diabetic complications such as diabetic retinopathy,nephropathy and neuropathy,highlighting that targeting complement system therapeutics could be one of possible routes to slow down those aforementioned diabetic complications. 展开更多
关键词 Inflammation COMPLEMENT activation Metabolic DISORDERS OBESITY Insulin resistance Type 2 DIABETIC MELLITUS
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GaN HEMT场板研究综述 预览
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作者 刘建华 郭宇锋 +2 位作者 黄晓明 黄智 姚小江 《南京邮电大学学报:自然科学版》 北大核心 2020年第1期9-14,共6页
GaN HEMT凭借其高电子迁移率、高二维电子气浓度和高击穿电压等特性,在高频、高温和高功率密度领域有着广泛的应用,是功率器件的研究热点。文中对GaN HEMT中应用的场板技术进行了归类与综述,讨论了源场板、栅场板、漏场板、浮空场板和... GaN HEMT凭借其高电子迁移率、高二维电子气浓度和高击穿电压等特性,在高频、高温和高功率密度领域有着广泛的应用,是功率器件的研究热点。文中对GaN HEMT中应用的场板技术进行了归类与综述,讨论了源场板、栅场板、漏场板、浮空场板和结型场板共5种场板技术,并从工作机理、性能指标以及工艺复杂度等方面进行了分析。结果表明,场板技术的引入能够显著提高器件的性能和可靠性,并且与其他电场优化技术相兼容,可以有效提高BFOM优值和JFOM优值,改善器件设计的折中关系,但同时会引入寄生电容,增加工艺复杂度。因此,如何在器件性能和工艺复杂度之间取得折中并对其物理机理进行深入研究,将是GaN HEMT器件的研究热点。 展开更多
关键词 氮化镓高电子迁移率晶体管 场板 击穿电压 导通电阻
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2018-2019年流感流行季节河北省流感病毒对神经氨酸酶抑制剂药物的耐药性研究
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作者 姜彩肖 韩光跃 +3 位作者 李岩 刘艳芳 刘兰芬 齐顺祥 《中华疾病控制杂志》 CAS CSCD 北大核心 2020年第2期233-236,共4页
目的分析河北省2018-2019年流感流行季节流感病毒对神经氨酸酶抑制剂类(neuraminidase inhibitor,NAI)药物的耐药情况,为流感的预防控制提供依据。方法选取H1N1(pdm09)亚型毒株25株、H3N2亚型毒株11株共36株流感病毒毒株进行生物学耐药... 目的分析河北省2018-2019年流感流行季节流感病毒对神经氨酸酶抑制剂类(neuraminidase inhibitor,NAI)药物的耐药情况,为流感的预防控制提供依据。方法选取H1N1(pdm09)亚型毒株25株、H3N2亚型毒株11株共36株流感病毒毒株进行生物学耐药实验,使用荧光发光法检测病毒对奥司他韦和扎纳米韦的药物敏感性。结果 2018-2019年河北省H1N1(pdm09)和H3N2亚型流感病毒全部对奥司他韦和扎那米韦敏感,对奥司他韦的半数抑制浓度(half maximal inhibitory concentration,IC_(50))平均数分别为0.50 nM(0.07~1.14 nM)和0.25 nM(0.09~0.69 nM),对扎那米韦的IC_(50)平均数分别为0.29 nM(0.09~0.85 nM)和0.87 nM(0.17~1.81 nM),均在相对应型别参考株IC_(50)值10倍以内。结论 2018-2019年河北省检测的流感毒株都对NAI类药物敏感。 展开更多
关键词 流感病毒 神经氨酸酶抑制剂 耐药性
碳青霉烯类抗菌药物使用现状调查 预览
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作者 杨桂玲 高义玲 +2 位作者 王贝 郑莹 朱明辉 《中国医药导刊》 2020年第1期38-42,共5页
目的:通过对我院碳青霉烯类抗菌药物使用现状的调查,评价药物使用的合理性及存在问题,以期采取对应措施,纠正临床医生药物使用上的不合理及不足之处。方法:采用回顾性调查方法,对我院2018年第四季度所有使用碳青霉烯类抗菌药物的出院患... 目的:通过对我院碳青霉烯类抗菌药物使用现状的调查,评价药物使用的合理性及存在问题,以期采取对应措施,纠正临床医生药物使用上的不合理及不足之处。方法:采用回顾性调查方法,对我院2018年第四季度所有使用碳青霉烯类抗菌药物的出院患者,根据《碳青霉烯类抗菌药物临床应用评价细则》(以下简称《细则》)进行评价并就结果进行临床用药分析。结果:碳青霉烯类抗菌药物使用量居前三的科室分别为呼吸内科、ICU、NICU;碳青霉烯类抗菌药物治疗有效病例59例,占比65.56%;碳青霉烯类抗菌药物以单药和二联应用为主,占比93.33%;符合《细则》中4种规定的适应证有43例,有10例患者同时联用了丙戊酸钠,使用碳青霉烯类抗菌药物的微生物送检率达94.44%,有23例邀请了院内特殊使用级抗菌药物会诊专家进行会诊,13个使用病区中有5个病区没有按照文件规定进行专档登记管理。结论:我院临床医生在碳青霉烯类抗菌药物的使用上基本合理,但还存在个别品种用量不足、缺少会诊记录、与丙戊酸钠配伍、专档登记不全等一系列问题,需要采取相应手段,促进碳青霉烯类抗菌药物的合理使用,以减少或降低细菌耐药性上升的风险。 展开更多
关键词 碳青霉烯 抗菌药物 耐药 现状调查
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Serum Irisin:Pathogenesis and Clinical Research in Cardiovascular Diseases 预览
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作者 Lutfu Askin Kader Eliz Uze +1 位作者 Okan Tanriverdi Serdar Turkmen 《Cardiovascular Innovations and Applications》 2020年第1期195-200,共6页
Recently,muscular function/dysfunction has gained importance in the maintenance of metabolic homeostasis in cardiovascular diseases.Skeletal muscle plays a vital role in coordinating the activity and metabolism of end... Recently,muscular function/dysfunction has gained importance in the maintenance of metabolic homeostasis in cardiovascular diseases.Skeletal muscle plays a vital role in coordinating the activity and metabolism of endocrine organs by secreting many myokines,especially irisin.Irisin is a polypeptide hormone consisting of 112 amino acids secreted into the blood from muscle and adipose tissues.Serum irisin levels are associated with cardiometabolic risk factors such as obesity and insulin resistance as defi ned by homeostatic model assessment.Irisin reduces endothelial damage by inhibiting infl ammation and oxidative stress,thus playing a key role in maintaining endothelial cell function.Unsurprisingly,low irisin levels cause endothelial dysfunction and increase the incidence of atherosclerosis.We aimed to summarize the studies on this issue since we have not found any review in the literature on the role of serum irisin levels in the process of atherosclerosis and other cardiovascular events in cardiovascular diseases. 展开更多
关键词 insulin resistance irisin cardiovascular diseases body mass index
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NF-kB Inhibitor Parthenolide Promotes Renal Tubules Albumin Uptake in Type 2 Diabetic Nephropathy 预览
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作者 Qiufa Hao Baobao Wang +3 位作者 Wei Zhang Wei Qiu Qianling Liu Xuemei Li 《中国医学科学杂志:英文版》 CAS CSCD 2020年第1期31-42,共12页
Objective Injured tubular reabsorption is highlighted as one of the causes of increased albuminuria in the early stage of diabetic nephropathy;however,the underlying mechanism has not been fiilly elucidated.In this st... Objective Injured tubular reabsorption is highlighted as one of the causes of increased albuminuria in the early stage of diabetic nephropathy;however,the underlying mechanism has not been fiilly elucidated.In this study,we aimed to explore whether reducing inflammation and remodeling the insulin signaling pathway could improve albumin uptake of renal tubules.Methods 8-week-old male db/db mice(n=8),a type 2 diabetic nephropathy model,administered with nuclear factor kappa-B(NF-kB)inhibitor parthenolide(PTN,1 mg/kg)intraperitoneally every other day for 8 weeks,were as the treatment group.Meanwhile,the age-matched male db/m mice(n=S)and db/db mice(n=8)were treated with saline as the control group and type 2 diabetic nephropathy group.When the mice were sacrificed,blood and urine were collected to examine homeostasis model assessment of insulin resistance(HOMA-IR)and urine albumin creatinine ratio,and kidney samples were used to analyze histopathologic changes with periodic acid-Schiff(PAS)staining,NF-kB p65,phosphorylation of AKT(p-AKT),amnionless and cubilin expressions with immunohistochemistry as well as western blot,and the albumin uptake of renal tubules by using immunofluorescence.In addition,HKC cells were divided into the insulin group treated with insulin alone,the TNF-a group treated with insulin and tumor necrosis factor(TNF-a),and the TNF-a+PTN group exposed to PTN,insulin and TNF-a.The levels of albumin uptake and expression levels of NF-kB p65,p-IRS-l/IRS-1,p-AKT/AKT,amnionless and cubilin in HKC cells were measured.Results Compared with the db/db group,the db/db+PTN group demonstrated decreased levels of HOMA-IR(36.83±14.09 vs.31.07+28.05)and urine albumin creatinine ratio(190.3±7.3 vs.143.0±97.6 mg/mmol);however,the differences were not statistically significant(P>0.05).Periodic acid-Schiff staining showed PTN could alleviate the glomerular hypertrophy and reduce the matrix in mesangial areas of db/db mice.The renal expression of NF-kB p65 was increased and p-AKT(s473)decreased in the db/db group 展开更多
关键词 inflammation insulin resistance ALBUMINURIA diabetic nephropathy PARTHENOLIDE
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Mechanical properties and wear resistance of ultrafine bainitic steel under low austempering temperature 预览
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作者 Wei Liu You-hui Jiang +3 位作者 Hui Guo Yue Zhang Ai-min Zhao Yao Huang 《矿物冶金与材料学报:英文版》 SCIE EI CAS CSCD 2020年第4期483-493,共11页
The mechanical properties and wear resistance of the ultrafine bainitic steel austempered at various temperatures were investigated.Scanning electron microscopy(SEM)and X-ray diffraction were used to analyze the micro... The mechanical properties and wear resistance of the ultrafine bainitic steel austempered at various temperatures were investigated.Scanning electron microscopy(SEM)and X-ray diffraction were used to analyze the microstructure.The worn surfaces were observed via laser scanning confocal microscopy and SEM.Results indicated that,under low austempering temperatures,the mechanical properties differed,and the wear resistance remained basically unchanged.The tensile strength of the samples was above 1800 MPa,but only one sample austempered at 230°C had an elongation of more than 10%.The weight loss of samples was approximately linear with the cycles of wear and nonlinear with the loads.The samples showed little difference in wear resistance at different isothermal temperatures,whereas the thickness of their deformed layers varied greatly.The results are related to the initial hardness of the sample and the stability of the retained austenite.Meanwhile,the experimental results showed that the effect of austempering temperature on the wear resistance of ultrafine bainitic steel can be neglected under low applied loads and low austempering temperature. 展开更多
关键词 bainitic steel mechanical properties wear resistance austempering temperature
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Chloride resistance of Cr-bearing alloy steels in carbonated concrete pore solutions 预览
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作者 Jing Ming Jin-jie Shi 《矿物冶金与材料学报:英文版》 SCIE EI CAS CSCD 2020年第4期494-504,共11页
The effect of carbonation on the chloride resistance of low-carbon steel and two Cr-bearing alloy steels in simulated concrete pore solutions was investigated.The chloride threshold values of steels were determined on... The effect of carbonation on the chloride resistance of low-carbon steel and two Cr-bearing alloy steels in simulated concrete pore solutions was investigated.The chloride threshold values of steels were determined on the basis of corrosion potential(Ecorr)and polarization resistance(Rp).Moreover,the chloride-induced corrosion behavior of steels was evaluated using electrochemical impedance spectroscopy,cyclic voltammetry,cathodic potentiodynamic polarization,and scanning electron microscopy/energy dispersive X-ray spectroscopy measurements.Alloy steels have higher chloride resistance than low-carbon steel in carbonated and non-carbonated concrete pore solutions.The chloride resistance of alloy steels improves with increasing Cr content.In addition,the chloride resistance of all steels is negatively affected by the carbonation of concrete pore solution,especially for alloy steel with high Cr content in the presence of high chloride content. 展开更多
关键词 alloy steel concrete pore solution CARBONATION chloride resistance electrochemical measurements
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Combination of Chinese and Western Medicine to Prevent and Reverse Resistance of Cancer Cells to Anticancer Drugs
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作者 SUI Xin-bing XIE Tian 《中国结合医学杂志:英文版》 SCIE CAS CSCD 2020年第4期251-255,共5页
Resista nee to anticancer drugs is a major problem in on cology,which causes the failure of an titumor treatme nt.A variety of factors con tribute to drug resistance,in eluding drug efflux and metabolism,tumor cell he... Resista nee to anticancer drugs is a major problem in on cology,which causes the failure of an titumor treatme nt.A variety of factors con tribute to drug resistance,in eluding drug efflux and metabolism,tumor cell heteroge neity,tumor microenvironment stress-induced genetic or epigenetic alterations in the cancer cells and so on.However,how to circumvent this resista nee to improve antican cer efficacy remains to be determined.To circumvent chemotherapeutic resista nee,many reversal agents have been developed,but most of them fail in clinical trials due to severe adverse effects.Recently,several natural products have been reported to augme nt sen sitivity or overcome resista nee of an ticancer chemotherapeutic drugs,including elemene,curcumin,Shenqi Fuzheng Injection(参芪扶正注射液),PHY906,etc.Thus,understand!ng the novel function of Chinese medicine may allow us to develop a promising therapeutic approach to enhance the effects of anticancer strategies and preve nt or overcome their resista nee in the treatment of can cer patie nts. 展开更多
关键词 Chinese medicine Western medicine integrative Chinese and Western medicine RESISTANCE an tica ncer drugs
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