检索结果-南通市图书馆

微合金化对高锰奥氏体钢在酸性盐雾环境下的耐蚀性能影响研究

在线全文

学校读者我要写书评

暂无评论

中国腐蚀与防护学报 2024年第1期44卷 47-58页

作者：常雪婷宋嘉琪王冰王东胜陈文聪王海丰上海海事大学海洋科学与工程学院上海201306 江南造船集团有限公司上海201913 西北工业大学凝固技术国家重点实验室西安710072

为进一步提升高锰钢耐蚀性能,研究了酸性盐雾环境下,Cr、N、Al等微合金化元素添加对全奥氏体高锰钢腐蚀过程和电化学性能的影响。通过失重法、场发射扫描电镜(SEM)、白光干涉仪等手段研究了高锰钢腐蚀产物微观结构及演变规律,并通过动... 详细信息

为进一步提升高锰钢耐蚀性能,研究了酸性盐雾环境下,Cr、N、Al等微合金化元素添加对全奥氏体高锰钢腐蚀过程和电化学性能的影响。通过失重法、场发射扫描电镜(SEM)、白光干涉仪等手段研究了高锰钢腐蚀产物微观结构及演变规律,并通过动电位极化、交流阻抗谱等电化学技术研究两种高锰钢电化学性能的演化规律。实验结果表明:随着腐蚀时间延长,微合金化高锰钢锈层致密度更高,在长周期腐蚀中具有最好的耐蚀性。盐雾环境中点蚀逐渐发展为均匀腐蚀,微合金化处理后的高锰钢腐蚀动力学规律为ΔW_(Wh)=4.44202×10^(-4)t0.9618,小于普通高锰钢的拟合结果ΔW_(Pt)=8.74985×10^(-4)t0.67759。电化学结果表明,两种高锰钢腐蚀电流密度随着腐蚀时间增加均逐渐减小,且容抗弧逐渐增大。其中,微合金化高锰钢腐蚀240 h后的容抗弧远远大于未处理高锰钢,且腐蚀速率为1.925×10^(-3)mm/a,小于未处理高锰钢。微合金化处理后的高锰钢耐蚀性能更优,主要原因为Cr、N、Al等元素的微合金化使高锰钢析出碳化物减少,表面生成的氧化物更牢固、致密,提高了高锰钢表面氧化膜的完整性,有效阻碍Cl-渗入,使腐蚀产物变得致密,进而降低钢的腐蚀速率。

关键词：高锰奥氏体钢盐雾试验微合金化腐蚀速率电化学测试

Novel pharmacological therapy in type 2 diabetes mellitus with established cardiovascular disease: Current evidence

在线全文

学校读者我要写书评

暂无评论

World Journal of Diabetes 2019年第5期10卷 291-303页

作者： Leonardo Pozo Fatimah Bello Andres Suarez Francisco E Ochoa-Martinez Yamely Mendez Chelsea h chang Salim Surani University of texas Rio Grande Valley-Doctors hospital at Renaissance Internal Medicine Residency Program Faculty of Medicine Universidad Autonoma de Nuevo LeonUniversity Hospital "Dr. José Eleuterio González" Faculty of Medicine "Dr. Alberto Romo Caballero" Universidad Autonoma de Tamaulipas Medical Critical Care Services Christus Spohn Hospitals-Corpus Christi

Cardiovascular diseases(CVDs) remain the leading cause of death in the world and in most developed countries. Patients with type 2 diabetes mellitus(t2DM)suffer from both microvascular and macrovascular diseases and therefore have higher rates of morbidity and mortality compared to those without t2DM. If current trends continue, the Center for Disease Control and Prevention estimates that 1 in 3 Americans will have t2DM by year 2050. As a consequence of the controversy surrounding rosiglitazone and the increasing prevalence of diabetes and CVDs, in 2008 the Food and Drug Administration(FDA) established new expectations for the evaluation of new antidiabetic agents, advising for pre and,in some cases, post-marketing data on major cardiovascular events. As a direct consequence, there has been a paradigm shift in new antidiabetic agents that has given birth to the recently published American Diabetes Association/European Association for the Study of Diabetes consensus statement recommending sodium-glucose cotransporter-2 inhibitors(SGLt2i) and glucagon like peptide-1 receptor agonists(GLP-1RA) in patients with t2DM and established CVD. As a result of over a decade of randomized placebo controlled cardiovascular outcome trials, the aforementioned drugs have received FDA approval for risk reduction of cardiovascular(CV) events in patients with t2DM and established CV ***2i have been shown to have a stronger benefit in patients with congestiveheart failure and diabetic kidney disease when compared to their GLP-1RA counterparts. these benefits are not withstanding additional considerations such as cost and the multiple FDA Black Box warnings. this topic is currently an emerging research area and this mini-review paper examines the role of these two novel classes of drugs in patients with t2DM with both confirmed, and at risk for, CVD.

关键词： type 2 diabetes mellitus Glucagon-like-peptide 1 agonists Sodium-glucose cotransporter-2 inhibitor Cardiovascular disease Major adverse cardiovascular event

Synthesis of 9,10-Phenanthrenes via Rh(III)-Catalyzed[4+2]Annulation of 2-Biphenylboronic Acids with Diazo Compounds

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2023年第11期41卷 1327-1332页

作者： Miaomiao tian Lingyun Yang Bingxian Liu Junbiao chang NMPA Key Laboratory for Research and Evaluation of Innovative Drug School of Chemistry and Chemical EngineeringHenan Normal UniversityPingyuan LaboratoryXinxiangHenan453007 China

A Rh(III)-catalyzed,transmetalation triggered C—h activation/annulation of 2-biphenylboronic acids with diazo compounds fromβ-keto esters or 1,3-dicarboxylates has been developed,leading to the synthesis of two kinds of 9,***,a rhodacyle was synthesized by treating the rhodium catalyst with stoichiometric amounts of 2-biphenylboronic acids and pyridine,which was further verified to be active for the catalytic *** reactions proceeded under redox-neutral and air-tolerant conditions to produce a series of all-carbon six-membered rings with high efficiency.

关键词： 9,10-Phenanthrenes Rh(Il)-catalyzed Diazo reagent transmetallation Annulation Carbocycles C-hactivation

血游离轻链与M蛋白检测在膜性肾病合并MGUS患者中的临床意义

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

国际医药卫生导报 2024年第17期30卷 2894-2899页

作者：赵辽辽常露元曹丽西安交通大学第一附属医院榆林医院肾病学科榆林719000

目的探讨血游离轻链(sFLC)与M蛋白检测在膜性肾病(MN)合并意义未明单克隆免疫球蛋白血症(MGUS)患者中的临床意义。方法研究采用前瞻性设计,纳入2021年1月至2023年10月在西安交通大学第一附属医院榆林医院诊治的82例MN患者,根据是否合并M... 详细信息

目的探讨血游离轻链(sFLC)与M蛋白检测在膜性肾病(MN)合并意义未明单克隆免疫球蛋白血症(MGUS)患者中的临床意义。方法研究采用前瞻性设计,纳入2021年1月至2023年10月在西安交通大学第一附属医院榆林医院诊治的82例MN患者,根据是否合并MGUS分为MN组(53例)和merge组(29例)。merge组男18例、女11例,年龄(52.64±7.33)岁;MN组男33例、女20例,年龄(55.35±6.89)岁。采用血清学检测方法对患者进行sFLC[κ轻链(sFLCκ)、λ轻链(sFLCλ)]与M蛋白检测,并通过logistic回归分析探讨其与MN合并MGUS的关系,并使用受试者操作特征曲线(ROC)检测sFLC联合M蛋白在MN合并MGUS诊断中的性能。统计学方法采用t检验、χ^(2)检验。结果merge组红细胞沉降率(ESR)、血清肌酐(Scr)、C反应蛋白(CRP)和血尿素氮(BUN)指标均高于MN组[(48.52±5.65)mm/h比(36.34±4.35)mm/h、(84.51±10.26)μmol/L比(72.65±8.25)μmol/L、(2.18±0.64)mg/L比(1.26±0.35)mg/L、(6.45±1.27)mmol/L比(5.12±1.12)mmol/L],差异均有统计学意义(t=10.884、5.702、8.434、4.902,均Pt=15.520、37.791、5.979,均P<0.05)。相关性分析结果显示,sFLCκ、sFLCκ/λ比值与肾功能损害及炎症水平有显著相关性,而sFLCλ相关性相对较弱。逻辑回归分析显示,sFLCκ、sFLCκ/λ比值对诊断具有显著影响,而sFLCλ具有负向影响。ROC分析显示,sFLC联合M蛋白进行诊断时,灵敏度为96.6%,特异度为77.4%,约登指数为73.9%,曲线下面积为0.933,95%CI 0.884~0.982。结论sFLC与M蛋白检测对于MN合并MGUS患者的诊断和疾病活动度评估具有重要临床意义,与肾功能损害程度密切相关,可为监测和治疗效果评估提供重要参考。

关键词：膜性肾病意义未明单克隆免疫球蛋白血症血游离轻链 M蛋白

A new localization theory of adaptive machining of near-net-shape blades

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2021年第6期34卷 18-32页

作者： Neng WAN Xiaogang ShEN Zhiyong chang Zezhong C.ChEN Department of Mechanical Engineering Northwestern Polytechnical UniversityXi'an 710072China Department of Mechanical Industrial and Aerospace EngineeringConcordia UniversityMontrealQuebec H3G IMSCanada

In the fabrication of aero-engine blades,a great deal is gained when massive material removal is avoided at the end of the process,and as little as possible material is left on the blade *** to the uncertainty of pre-process,the billet shapes are ***,the near-net-shape billet doesn’t cover the blade design surface to be ***,blade localization is necessary for these billets before the *** conventional localization methods,the design surface’s location focused on guaranteeing enough material to be ***,because the to-becut surface is in near-net and free-form shape,it is difficult to find a valid localized surface model to generate the tool *** from the localized surface is taken as rigid in previous investigation,it is allowed to deviate from the design surface no more than the tolerance *** term of this principle,the tolerance band is utilized to promote localization ability.A series of optimization models with different priorities is established to avoid the abandonment expensive blade ***,with the experiments performed on the near-net-shape blades,the blade localization theory and the promotion of localization ability are verified.

关键词： Blade localization Curvature constraint Machining surface Near-net-shape blade tolerance constraint

温经活络方治疗胶原诱导性关节炎小鼠模型实验研究

在线全文

学校读者我要写书评

暂无评论

中国中西医结合杂志 2024年第6期44卷 717-724页

作者：卢璐许小芬崔晓慧胡长锋张纪达浙江中医药大学附属第三医院中药药剂科杭州310013 浙江中医药大学基础医学院杭州310053

目的基于肿瘤坏死因子α(tNF-α)/核因子-κB(NF-κB)及辅助性t细胞17(th17)细胞分化探讨温经活络方治疗胶原诱导性关节炎(CIA)小鼠作用机制。方法 40只6周雄性DBA/1小鼠采用随机数字表法分为正常对照组、模型组、甲氨蝶呤组和温经活... 详细信息

目的基于肿瘤坏死因子α(tNF-α)/核因子-κB(NF-κB)及辅助性t细胞17(th17)细胞分化探讨温经活络方治疗胶原诱导性关节炎(CIA)小鼠作用机制。方法 40只6周雄性DBA/1小鼠采用随机数字表法分为正常对照组、模型组、甲氨蝶呤组和温经活络方组,共4组,每组10只。以胶原注射的方式构建胶原诱导性关节炎模型,在初次免疫后21天起分别以双蒸水、甲氨蝶呤、温经活络方干预35天,期间每周评价各组小鼠的体重,从初次免疫后第24天起每周评价各组足肿胀度、关节炎症评分。hE染色检测足趾及踝关节病理改变情况;酶联免疫吸附(ELISA)法检测小鼠血清中抗环瓜氨酸肽抗体(CCP-Ab)、小鼠白细胞介素-6(IL-6)和tNF-α水平;实时定量聚合酶链式反应(Rt-qPCR)检测足关节NF-κB、骨保护素(OPG)和破骨细胞分化因子(RANKL)mRNA表达水平;免疫蛋白质印迹(Western Blot)检测小鼠脾脏及足关节NF-κB、p-NF-κB表达情况;流式细胞术检测小鼠脾脏中th17细胞表达情况。结果与正常组比较,模型组小鼠毛发枯槁,进食量减少,体重明显降低(PtNF-α含量升高(Pth17细胞比值显著升高(PtNF-α、IL-6水平下降(Pth17细胞表达明显抑制(PtNF-α、IL-6等相关炎症因子表达,进一步抑制tNF-α/NF-κB信号通路及th17细胞的活化,从而减轻RA关节炎症、降低关节炎症评分、抑制骨质破坏、改善其病理变化。

关键词：类风湿关节炎温经活络方炎症因子核因子-κB 辅助性t细胞17 中药复方

Probiotic Bio-three induces th1 and anti-inflammatory effects in PBMC and dendritic cells

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2010年第28期16卷 3529-3540页

作者： Man-Chin hua tzou-Yien Lin Chien-chang Chen Ming-Wei Lai Man-Shan Kong hung-Ju chang Department of Pediatrics chang Gung Memorial hospital Keelung 204 taiwan China Graduate Institute of Clinical Medical Sciences College of Medicine chang Gung University taoyuan 333 Division of Infectious Disease Division of Gastroenterology Department of Pediatrics Chang Gung Memorial HospitalTaoyuan 333TaiwanChina

AIM:to investigate the immune response of peripheral blood mononuclear cells(PBMCs)and dendritic cells (DCs)that were stimulated by probiotic preparations. MEthODS:PBMCs were isolated,cultured,and stimulated with Bio-three(a mixture of Bacillus mesentericus, Clostridium butyricum and Enterococcus faecalis;105, 10 6 and 10 7 CFU/mL for 24 h).Cytokine production of (1)circulating PBMCs;(2)PBMCs stimulated by probiotic preparation;(3)monocyte-derived DCs;and(4)DC andt cell co-culture was determined by enzyme-linked immunosorbent *** analysis of circulating PBMCs was also investigated by flow *** was obtained from individuals who consumed Bio-three (10 9 CFU/d ***,*** and ***) for 2 wk,or those who did not take probiotics orally. RESULtS:In culture supernatants,interferon-γ(IFN-γ) and interleukin(IL)-10 production increased,but IL-4 and tumor necrosis factor-α(tNF-α)production by PBMCs decreased after 1 and 2 wk of probiotic *** cytometry was also performed on day 14 and detected enhanced expression of CD11b,hLA-DR, CD4,CD45RA,CD25,CD44 and CD69 in response to ***,IL-10 and IL-12 were upregulated in supernatants of monocyte-derived DCs,and IFN-γand IL-10 were enhanced in supernatants of CD4 + t cells co-cultured with DCs. CONCLUSION:Bio-three appeared to stimulate the th1 immune response,downregulate pro-inflammatory cytokines(tNF-α)and upregulate anti-inflammatory cytokine(IL-10).Probiotics could be effective in activation of PBMCs and DCs.

关键词： Probiotics Bio-three Peripheral blood mono- nuclear cells Dendritic cells

Efficient Energy-preserving Methods for General Nonlinear Oscillatory hamiltonian System

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2018年第12期34卷 1863-1878页

作者： Yong Lei FANG chang Ying LIU Bin WANG School of Mathematics and Statistics Zaozhuang University Zaozhuang 277160 P. R. China School of Mathematics and Statistics Nanjing University of Information Science ~ Technology Nanjing 210044 P. R. China School of Mathematical Sciences Qufu Normal University Qufu 273165 P. R. China

In this paper, we propose and analyze two kinds of novel and symmetric energy-preservmg formulae for the nonlinear oscillatory hamiltonian system of second-order differential equations Aq＂（t）＋ Bq（t） = f（q（t））, where A ∈ R^m×m is a symmetric positive definite matrix, B ∈ R^m×m is a symmetric positive semi-definite matrix that implicitly contains the main frequencies of the problem and f（q） = -VqV（q） for a real-valued function V（q）. the energy-preserving formulae can exactly preserve the hamiltonian h（q＇,q） = 1/2q＇^tAq＇＋ 1/2q^tBq - V（q）. We analyze the properties of energy-preserving and convergence of the derived energy-preserving formula and obtain new efficient energy-preserving integrators for practical computation. Numerical experiments are carried out to show the efficiency of the new methods by the nonlinear hamiltonian systems.

关键词： Nonlinear hamiltonian wave equations energy-preserving schemes Average Vector Field method oscillatory systems

Facile synthesis of ultrathin metal-organic framework nanosheets for Lewis acid catalysis

在线全文

学校读者我要写书评

暂无评论

Nano Research 2019年第2期12卷 437-440页

作者： Xiaofei Zhang Lin chang Zhongjie Yang Yanan Shi chang Long Jianyu han Binhao Zhang Xueying Qiu Guodong Li Zhiyong tang School of Materials Science and Engineering Harbin Institute of Technology Harbin 150080 China CAS Key Laboratory of Nanosystem and hierarchical Fabrication CAS Center for Excellence in Nanoscience National Center for Nanoscience and Technology Beijing 100190 China

Ultrathin metalorganic framework (MOF) nanosheets are attracting great interest in catalysis due to their unique and intriguing two-dime nsional (2D) features. Although many progresses have been achieved, it is still highly desirable to develop novel strategies for controllable synthesis of the well-defined ultrathin MOF nanosheets. herein we report a polyvinylpyrrolidone (PVP)-assisted route to synthesize the ultrathin Ni-MOF nanosheets characteristic of 1.5 nm in thickness, in which PVP is reacted with 2-aminoterephthalic acid (h2BDC-Nh2) via formation of C=N bon d, followed by coord inatio n with Ni2+ io ns to form the ultrathi n MOF n anosheets. Impressively, when used in the Kno eve nagel condensation reactions of propane dinitrile with different aldehydes, ultrathin Ni-MOF nanosheets display the significantly enhanced catalytic activity and good stability in respect with the bulk Ni-MOF, mainly owing to the exposed active sites as well as facile mass transfer and diffusion of substrates and products.

关键词： ultrathin nanosheet metal-organic framework Lewis acid site Knoevenagel condensation