93 research outputs found

    中国南方地区罗非鱼无乳链球菌的分子流行病学研究

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    从广东省以及海南省等地区养殖的患病罗非鱼体内分离、收集到多株致病菌,经生化分析和分子生物学鉴定,均为无乳链球菌。对这些菌株分别进行了耐药谱测定、分子分型试验以及分子血清型分析。药敏试验结果表明,2007—2010年分离到的无乳链球菌耐药谱基本相似;多位点可变数目串联重复序列分析(MLVA)试验中,选择5个高变异指数的可变数目重复位点(VNTR)进行分子分型,结果表明,所有鱼源无乳链球菌菌株为同一MLVA型,而作为对照的牛源无乳链球菌则明显不同;为了对这些菌株进一步分型,分别进行了分子血清型和表面蛋白抗原基因的检测,结果表明,鱼源无乳链球菌的分子血清型均为Ⅰa型,表面蛋白抗原均为alpha-C蛋白。这进一步说明了不同年份和不同地区的鱼源无乳链球菌在基因水平上为同一分子类型,具有相同的起源或传染源。同时也说明,我国南方地区罗非鱼无乳链球菌在这几年中未发生明显的遗传变异。这些结果为罗非鱼无乳链球菌病疫苗研制,疫病监测及药物防治的研究提供理论依据

    Studies of the Mg-Al and Cation-Incorporated Hydrotalcites

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    研究了掺杂阳离子水滑石的制备及阳离子对水滑石性质的影响.分别制备了掺杂Zn2+、Ni2+、Fe3+型的水滑石,考察了掺杂阳离子对水滑石晶相结构、层间距、层间阴离子含量、水滑石表面形态、水滑石碱性的影响,结果表明,由于阳离子的引入,导致水滑石层间距减小及层间阴离子结合量降低,且使水滑石培烧产物电负性提高,并最终降低其碱性.以上述水滑石培烧产物作为固体碱催化剂促进苯甲醛和丙醛缩合,合成α-甲基肉桂醛,关联了水滑石培烧产物碱性与反应活性的关系.Mg-Al and cation-incorporated(containing Zn2+?Ni2+?Fe3+) hydrotalcites were synthesized and characterized. A detailed comparative analysis of structure and composition was made. Different cations influenced strongly textural parameters of hydrotalcites and the basicity of the obtained Mg-Al oxides after calcinations. With the cation incorporation, the distance of the brucite and the mount of CO2-3 as the compensating anion changed. Meanwhile the CO2-TPD was used to determine the basicity of the samples. The results showed that the basicity of the calcined hydrotalcites reduced. Finally, the activated hydrotalcite catalysts may efficiently replace homogeneous catalysts in Claisen-Schmidt condensation reaction of the benzaldehyde and propanal. And it was noteworthy that the calcined cation-type(containing Zn2+?Fe3+) hydrotalcites as catalysts did not show significant activity, in agreement with their low basicity.国家自然科学基金(20203014)资助项

    血液病患者中庚型肝炎病毒检测及感染情况研究

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    目的:了解武汉地区血液病患者中庚型肝炎病毒(HGV)的感染情况,探讨HGV的传播途径。方法:采用酶联免疫吸附试验(ELISA)及逆转录聚合酶链反应(RT-PCR)方法测定各型血液病患者血清中的抗HGV和HGV RNA。结果:51例血液病患者中血清抗HGV阳性6例,占11.8%(5/61),HGV RNA均阴性。6例抗GHV阳性患者中急粒2例,占25%(2/8),慢粒1例,占50%(1/2),再障2例,占50%(2/4),粒细胞缺乏症1例,占100%(1/1)。6例抗HGV阳性患者均有受血史,占18.7%(6/32),显著多于无受血史者。6例抗HGV阳性患者有1例ALT升高,且发生在化疗结束后,与抗HGV阴性患者无显著性差异。结论:血液病患者中存在HGV感染,输血是其主要传播途径,且与受血次数呈正相关。HGV病毒血症时间短,为自限性,致病力弱,不单独引起肝损害,也不加重化疗所致的肝损害

    性滥人群庚型肝炎病毒感染状况

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    目的:调查湖北地区性滥人群庚型肝炎病毒(HGV)感染状况。方法:检查309例有性滥史者的血清HGV感染标志物,用ELISA方法检测抗HGV。结果:309例性滥者HGV的感染率11.97%(37例),显著高于普通人群(1.51%,19/1257例)。女性HGV的感染率(12.36%,32/259例)与男性HGV的感染率(10%,5/50例)无显著差异。性滥时间大于2年者抗HGV阳性率17.05%(30/176例)显著高于性滥时间小于2年者5.26%(7/133例)。女性中有吸毒史者的HGV感染率(22.37%,17/76例)显著高于未吸毒者(8.20%,15/183例)。所有HGV感染者的肝功能正常。结论:性滥人群具有较高的HGV感染率,HGV可能通过性途径传播。性滥人群HGV的感染率与性滥时间呈正相关,吸毒增加了性滥者HGV感染的风险

    药瘾者庚型肝炎病毒感染状况及其影响因素

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    目的:调查湖北地区药瘾者HGV感染状况及其影响因素。方法:检查药瘾者的血清HGV感染指标,用ELISA法检测抗 HGV。结果:716例药瘾者HGV的感染率为12 . 85 % (92例)。静脉药瘾者抗 HGV阳性率为16 96% ,口服药瘾者为5 . 73 % ,两者比较差异有显著性意义(χ2 =10 8 .3 1,P 0 .0 5 ) ;3 45例女性药瘾者中卖淫者抗 HGV阳性率显著高于无卖淫史药瘾者(χ2 =4 10 ,P 0 . 0 5 ) ;抗 HCV (+ )者和抗 HCV (-)者的抗 HGV阳性率差异有显著性意义(χ2 =19 .2 6,P <0. 0 1)。所有HGV感染者的肝功能正常。结论:药瘾者具有较高的HGV感染率。药瘾者HGV感染率与吸毒时间呈正相关

    湖北地区特殊人群庚型肝炎病毒感染状况及其影响因素

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    目的:调查湖北地区性滥者和药瘾者HGV感染状况及其影响因素。方法:检查药瘾者和性滥者的血清HGV感染指标,用ELISA法检测抗HGV。结果:2206例标本中普通健康体检者1257例;949例为特殊人群(药隐者716例,性滥者309例,其中76例既是药瘾者又是性滥者),其HGV感染率分别为12.85%(75/716)、11.97%(20/309)、22.37%(17/76),均显著高于普通人群(1.51%,19/1257)。药瘾和性滥2年以上者抗HGV阳性率(19.41%,17.05%)显著高于药瘾和性滥2年以下者(8.01%,5.26%;χ2分别为19.29和8.89,P0.05);抗HCV(+)者和抗HCV(-)者的抗HGV阳性率差异有显著性意义(χ2分别为19.26和4.25,P<0.05)。所有HGV感染者的肝功能正常。结论:药瘾者和性滥者均具有较高的HGV感染率。其HGV感染率与吸毒时间或性滥时间呈正相关

    In situ Raman spectroscopic evidence for oxygen reduction reaction intermediates at platinum single crystal surfaces

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    铂基催化剂表面的氧还原反应(ORR)是燃料电池重最重要的阴极反应。虽然经过几十年的研究,ORR的具体反应路径并没有真正解析清楚。在本研究中,李剑锋教授课题组首次利用其发展的电化学壳层隔绝纳米粒子增强拉曼光谱(SHINERS)技术原位研究了Pt(hkl)单晶表面的ORR反应过程,成功捕获到在1150 cm-1、1080 cm-1和732 cm-1区域O2-、OH*和HO2*等重要反应中间物种的直接拉曼光谱证据,并通过相应的同位素取代实验(氘和O-18同位素实验)及DFT理论模拟确认了中间物种的谱峰归属和吸附构型。总的来说,该项研究首次在Pt(hkl)单晶表面原位获得ORR反应重要中间物种的直接拉曼光谱证据,提出合理的ORR反应路径,加深了人们对ORR反应机理的认识,也为其他界面催化反应机理的研究提供了一条可行的研究思路。 该研究工作由校内外多个课题组共同努力完成,化学化工学院李剑锋教授课题组负责相关电化学原位拉曼光谱实验,Alicante大学Juan Feliu教授课题组负责单晶电化学实验,化学化工学院吴德印教授课题组负责DFT理论模拟,物理系杨志林教授课题组负责3D-FDTD的理论模拟。该研究工作的第一作者董金超和第二作者张霞光分别为化学化工学院2014级博士生(已毕业)和2015级博士生。【Abstract】Developing an understanding of structure-activity relationships and reaction mechanisms of catalytic processes is critical to the successful design of highly efficient catalysts. As a fundamental reaction in fuel cells, elucidation of the oxygen reduction reaction (ORR) mechanism at Pt(hkl) surfaces has remained a significant challenge for researchers. Here, we employ in situ electrochemical surface-enhanced Raman spectroscopy (SERS) and density functional theory (DFT) calculation techniques to examine the ORR process at Pt(hkl) surfaces. Direct spectroscopic evidences for ORR intermediates indicates that under acid conditions, the pathway of ORR at Pt(111) occurs through the formation of HO2, while at Pt(110) and Pt(100) it occurs via the generation of OH*. However, we propose that the pathway of ORR under alkaline conditions at Pt(hkl) surfaces mainly occurs through the formation of O2- . Significantly, these results demonstrate that the SERS technique offers an effective and reliable way for real-time investigation of catalytic processes at atomically flat surfaces.This work was supported by the NSFC (21522508, 21427813, 21521004, 21533006, 21621091,and 21775127), "111" Project (B16029 and B17027), Natural Science Foundation of Guangdong Province (2016A030308012), the Fundamental Research Funds for the Central Universities (20720180037), and the Thousand Youth Talents Plan of China. Support from MINECO and Generalitat Valenciana (Spain), through projects CTQ2016-76221-P (AEI/FEDER, UE) and PROMETEOII/2014/013 respectively, is greatly acknowledged. V.B.M thankfully acknowledges to MINECO the award of a pre-doctoral grant (BES-2014-068176, project CTQ2013-44803-P). 该研究工作得到国家自然科学基金委(21522508、21427813、21521004、21533006、21621091和21775127)的大力资助和支持。化学化工学院周志有教授、程俊教授,材料学院张华副教授,英国利物浦大学Gary Attard教授,以及化学化工学院苏敏、王耀辉、卢邦安等博士生和杨晓冬博士对本课题的研究给予了大力的支持和帮助

    Constraint of a ruthenium-carbon triple bond to a five-membered ring

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    含过渡金属碳三键(M≡C)的金属卡拜化合物是许多有机反应的催化剂或关键中间体。对其合成及性质的研究是金属有机化学的热点之一。由于卡拜碳的sp杂化方式,大部分金属卡拜化合物均为链状结构(卡拜碳键角理想值为180 °),环内金属卡拜化合物因存在很大的环张力而难于合成。夏海平教授课题组发展了由链状多炔(称之为碳龙)构筑碳龙配合物的高效方法(Nature Communications, 2017, 8, 1912),实现了锇杂戊搭炔/烯及其衍生物的一锅法合成。现在,他们把该方法进一步拓展到了第二过渡系金属钌,通过碳龙与市售的RuCl2(PPh3)3反应一锅合成了钌杂戊搭炔I。本研究是碳龙化学的进一步延伸和发展,首次把碳龙化学的金属中心由锇拓展到了其它金属,展示了碳龙化学广阔的发展空间。该研究工作在夏海平教授指导下完成,能源材料化学协同创新中心(iChEM)博士后卓庆德和张弘副教授为共同第一作者。iChEM博士后周小茜、博士生陈志昕、林剑锋、卓凯玥、硕士康慧君、林鑫磊参与了部分实验工作。博士生华煜晖负责理论计算。【Abstract】The incorporation of a metal-carbon triple bond into a ring system is challenging because of the linear nature of triple bonds. To date, the synthesis of these complexes has been limited to those containing third-row transition metal centers, namely, osmium and rhenium. We report the synthesis and full characterization of the first cyclic metal carbyne complex with a second-row transition metal center, ruthenapentalyne. It shows a bond angle of 130.2(3)° around the sp-hybridized carbyne carbon, which represents the recorded smallest angle of second-row transition metal carbyne complexes, as it deviates nearly 50° from the original angle (180°). Density functional theory calculations suggest that the inherent aromatic nature of these metallacycles with bent Ru≡C–C moieties enhances their stability. Reactivity studies showed striking observations, such as ambiphilic reactivity, a metal-carbon triple bond shift, and a [2 + 2] cycloaddition reaction with alkyne and cascade cyclization reactions with ambident nucleophiles.This research was supported by the National Key R&D Program of China (2017YFA0204902) and the National Natural Science Foundation of China (nos. 21490573,21332002, and 21561162001). 研究工作得到国家自然科学基金项目(21490573、21332002 和21561162001)和国家重点研发计划(2017YFA0204902)的资助

    Studies of the Mg-Al and cation-incorporated hydrotalcites

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    Mg-Al and cation-incorporated(containing Zn2+Ni2+Fe3+) hydrotalcites were synthesized and characterized. A detailed comparative analysis of structure and composition was made. Different cations influenced strongly textural parameters of hydrotalcites and the basicity of the obtained Mg-Al oxides after calcinations. With the cation incorporation, the distance of the brucite and the mount of CO32- as the compensating anion changed. Meanwhile the CO2-TPD was used to determine the basicity of the samples. The results showed that the basicity of the calcined hydrotalcites reduced. Finally, the activated hydrotalcite catalysts may efficiently replace homogeneous catalysts in Claisen-Schmidt condensation reaction of the benzaldehyde and propanal. And it was noteworthy that the calcined cation-type (containing Zn2+, Fe3+) hydrotalcites as catalysts did not show significant activity, in agreement with their low basicity
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