简介:Thehydrationoftricalciumaluminate(C3A)hasasignificanteffectontheeffectivenessofcement-basedsystems.Inaddition,thecarbonationofhydrationproductsofC3Aisparticularlyimportantinrespectofdurabilityperformance.ThepresentworkinvestigatesthehydrationandcarbonationreactionsofC3AandthechangesinducedbythepresenceoftheheavymetalionssuchasZn2+,Pb2+,Cu2+andCr3+byX-raydiffractometry(XRD).DuringhydrationofC3A,gehlenitehydrate,hydrogarnet,calciummonoaluminate(C4AHx)andcalciumcarboaluminateweredetectedinC3ApastesexcepttheZn2+dopedpaste,wherehydrogarnetdidnotform.Theexaminationsrevealedthatheavymetalscoexistedwithgehlenitehydrate,calciummonoaluminate(C4AHx)andcalciumcarboaluminate,inhibitingtheformationofhydrogarnet.HydratingC3Awasliabletobecarbonatedonexposuretoairandcarbondioxide,especiallyinthepresenceofheavymetals,resultingintheformationofcarboaluminateand/orcalciumcarbonate.Thepresenceofheavymetalsin-fluencedthepolymorphismofcalciumcarbonate,ndicatingthatheavymetalscouldco-precipitatewithcalciumtoformacarbonatesolidsolution.
简介:背景:针对颈椎后路单开门椎管扩大成形术,C3椎板2种处理方式(C3椎板切除与C3椎板成形)的临床效果以及对术后颈椎功能的影响如何,相关客观评价较少,为此进行了此项研究。目的:系统评价颈椎后路椎管扩大成形术中C3椎板切除与C3椎板成形治疗多节段脊髓型颈椎病的疗效。方法:计算机检索CochraneCentral、PubMed、EMbase、theISIWebofKnowledgeDatabase、CNKI、CMB、维普、万方数据库,检索时间均为建库时间至2018-07-01。纳入关于C3椎板切除和椎板成形治疗多节段脊髓型颈椎病疗效对比的随机或非随机对照试验。Meta分析采用Cochrane协作网提供的Rev-Man5.3软件进行。结果与结论:①共纳入5个研究,316例患者,其中C3椎板切除组146例,C3椎板成形组170例;②Mate分析结果显示,在术后颈椎功能方面,与传统C3椎板成形相比,C3椎板切除术后颈椎活动度丢失较少[SMD=-5.89,95%CI(-7.25,-4.70),P<0.05]、术后轴性症状发生率低[SMD=-0.23,95%CI(0.12,0.46),P<0.05];③在神经功能恢复方面,2组术后日本骨科协会评分差异无显著性意义[SMD=-0.02,95%CI(-0.55,0.51),P=0.95>0.05];④结果表明,采用椎管扩大成形治疗多节段脊髓型颈椎病时C3椎板的2种处理方式(椎板切除或椎板成形)均能取得较好的临床效果,但椎板切除能有效防止颈椎活动度丢失、降低术后轴性症状发生率。
简介:[Co3(1,2-S2C6H4)3(PPh3)3][CoBr3(DMF)].sol(1,sol=CHCl3,O(C2H5)2,H2O)wasobtainedfromthereactionofCoBr(PPh3)3withNa2(S2C6H4)inchloroform.TheCo3coreinthecationof1exhibitsametal-metalbondedisoscelestriangle,inwhichthetwolongerCo-CobondsarebothbridgedbyS2C6H4ligandsontwosidesofthetriangleplanerespectively,whilethebottomshortCo-CobondisbridgedbythethirdbidentateS2C6H4ligand.Aseriesofpolynu-clearcobaltclustercompoundswithphosphine,thiolateand/orsulphurligandswerepreparedbylowoxidationstateCo+withthiolatesinorganicsolvents.Thesetri-,tetra-,hexa-,heptanuclearclustercompounds1-8withvarioustypesofcrystalstructurescanbeviewedasthecondensedpolynuclearcobaltcomplexesthatthecobaltatomframeworkswithsulphurbridgedwerebuiltthroughthesmalltriangularunitsof[Co3S3nL3](n=1,2)withorwithout[CoL](L=PR3,Br,Cl,5-C5H5)fragments.
简介:摘要目的探讨肝硬化合并肝癌及单纯肝癌患者不同child分级时补体C3、C4的表达意义。方法选取肝癌患者121例,健康对照组37例,均测定补体C3、C4含量。将肝癌患者分为肝硬化合并肝癌组及单纯肝癌组,并根据Child评分分级分组,比较两组间C3、C4水平的差异。结果1肝癌两组中随着Child分级由A级至C级变化血清补体C3水平逐渐降低,而补体C4水平则逐渐升高。2组间比较A级、B级时单纯肝癌组补体C3、C4水平均高于肝硬化合并肝癌组。单纯肝癌组与对照组比较差异同样有显著性。结论血清补体C3、C4与肝功能损伤严重程度相关,结合Child分级可更好地反映肝癌及肝硬化合并肝癌时肝脏储备功能及体液免疫水平,对临床诊治有重要意义。
简介:AbstractBackground:Aberrant activation of the complement system plays an important role in the pathogenesis and development of immunoglobulin A nephropathy (IgAN). The relationship between serum complement and the clinical-histopathological features and outcomes of IgAN is controversial. This retrospective study aimed to examine the relationship between the complement 3/4 (C3/C4) ratio and the clinicopathologic changes and prognosis of patients with IgAN.Methods:A total of 397 patients with primary IgAN from January 2007 to December 2012 at the Chinese People’s Liberation Army General Hospital were included in this study. The correlation test and Chi-square test or one-way analysis of variance test were performed to evaluate the relationship between the C3/C4 ratio and other clinical-pathological factors. Propensity score matching and a multivariate Cox regression model were used to calculate the risk factors of renal outcome.Results:The median follow-up period was 75 months. During the follow-up period, 62 patients (15.6%) developed into the end-stage renal disease (ESRD). The C3/C4 ratio at baseline was associated with the level of serum creatinine (SCr), 24 h urinary protein excretion (24 h Upre), global glomerular sclerosis, and tubulointerstitial lesion. The level of SCr and 24 h Upre and the degree of chronic kidney injury were statistically different among groups defined by different C3/C4 ratio levels. The survival rates of patients among groups with different C3/C4 ratio levels were different. After propensity score matching, eighty-eight pairs of patients were successfully matched, and the C3/C4 ratio was an influencing factor for the patients’ outcome (hazard ratio 0.587, 95% confidence interval 0.329-0.880). Patients with a C3/C4 ratio <3.6 had a poorer outcome compared with the others (P = 0.002).Conclusions:IgAN patients with decreased C3/C4 ratio displayed significantly more severe clinical symptoms and chronic renal injury than patients with higher ratios. A low C3/C4 ratio could be a risk factor for patients developing to ESRD.
简介:通过固相法和溶胶-凝胶法合成不同碳含量的磷酸钒锂/C正极材料,研究了作为碳源的蔗糖和柠檬酸添加量对产物电化学性能的影响.实验发现,在固相合成方法中,添加量高于10.5%(质量百分数)时进一步增加蔗糖添加量后产物放电容量变化不明显.但是在溶胶-凝胶合成方法中,柠檬酸的添加量存在最佳值,高于或者低于此最佳数值都会引起产物容量的降低,这是与固相合成技术的一个明显不同之处.另一点不同之处在于对于溶胶凝胶合成的样品,最佳添加量与产物的工作电流有关.本实验条件下,在0.2C倍率以下柠檬酸与氢氧化锂最佳比值为1∶3,但是在放电倍率高于0.5C时最佳比值为1∶2.
简介:采用密度泛函B3LYP/6-311G(d,p)方法对CH3F与C2H3的反应体系进行了理论研究,获得了反应的势能面信息及可能的微观机理.在QCISD(T)/6-311++G(d,p)水平上精确计算了各反应物种的单点能.结果表明,除抽提氢反应外,标题反应还存在抽提氟(R1)、消氟化氢(R2)、消氢(R3)和自由基形成(R4)四类反应.在QCISD(T)/6-311++G(d,p)//B3LYP/6-311G(d,p)水平上,R1,R2,R3和R4反应的能垒分别是163.9,152.2,209.8和224.2kJ·mol-1,相应反应能为-56.6,-164.3,-2.7和-156.0kJ·mol-1,所有反应均放热,为热力学允许的反应.
简介:通过建立一个基于电商交易平台的地理标志保护(GI)农产品的理性预期模型,电商平台联合GI农产品的相关线下权益方,采取措施以保护线上买家的利益,以此提高买家对GI农产品的信任度,扩大交易额.结果表明,电商平台对于GI农产品的质量保证措施收效有限,GI农产品的线下权益方,即行业协会或地方政府应充分发挥它们的能监管职,增强对种植和生产过程的监控和引导,同时,加强线上和线下的合作.
简介:Tris)(η5-cyclopentadienyl-μ-carbonyl-iron)-μ3-nitrosylclusterwasobtainedfromthereactionofcyclopentadienyldicarbonylirondimerwithnitrogenmonoxideinxylene.Theclusterwascharacterizedbyelementalanalyses,IR,MSand1HNMR.Thecrystalstructureof[(η5-C5H5)(μ-CO)Fe]3(μ3-NO).C4H8OwasdeterminedbyX-raydiffractionanalysis.ItcrystallizesintheorthorhombicspacegroupPnma,a=9.053(2),6=10.545(2),c=22.525(4)A,V=2150.3(7)A3,Z=4,Dc=1.68g.cm-3;structuresolutionandrefinementbasedon1141reflectionswithI>3.0(I)(MoKa,A=0.71073A)convergedatR=0.0540.Theinfraredabsorptionbandat1325cm-1oftheμ3-NOinthecluster,whichisredshifted,showsthatμ3-NOisactivated.