时间分辨荧光免疫法检测日本鳗鲡的产酸克雷伯氏菌

从皮肤点状出血的日本鳗鲡中分离出产酸克雷伯氏菌菌株B12,经福尔马林灭活后,注射新西兰兔,制备免疫抗血清,G蛋白亲和层析纯化得到抗体（IgG）,以固定于微孔板的IgG作为捕获抗体,Eu³⁺螯合物标记的IgG作为检测抗体,建立了产酸克雷伯氏菌的夹心型时间分辨荧光免疫检测法（TRFIA）,并研究了抗体浓度、免疫时间及离解时间对检测的影响。本方法检出限为5.0×10³ cfu/mL;线性范围5.0×10³～1.0×10⁷ cfu/mL,相关系数达0.99以上。交叉反应表明其具有较高的特异性,板内和板间相对标准偏差分别为5.64%和2.27%。将本方法标准化后,检测了29份人工感染的日本鳗鲡样品,包括鳃、肾、肠、肝和肌肉组织,结果满意。     

镥铕共发光时间分辨荧光免疫法检测嗜水气单胞菌

建立了共发光时间分辨荧光免疫检测嗜水气单胞菌的新方法,以嗜水气单胞菌菌株B11包被微孔板,与Eu3+标记的兔抗IgG免疫反应后,加入含有共发光离子Lu3+的解离增强剂,由于Eu3+和Lu3络合物的共发光效应,时间分辨荧光大大增强,有效放大了检测信号,提高了检测灵敏度.优化了共发光体系的条件,方法的检出限为1.0×103...     

量子点标记链霉亲和素及其生物活性检测

选用无机盐为前驱体,在水相中合成CdTe量子点,并用此量子点标记链霉亲和素,通过SephadexG-100层析分离纯化量子点标记的链霉亲和素,采用磁颗粒标记的链霉亲和素与量子点标记的链霉亲和素竞争结合辣根过氧化酶标记的生物素,即酶联免疫竞争抑制分析法检测链霉亲和素标记量子点后的生物活性,计算约70.3%的链霉亲和素标记到量子点上,且具有生物活性。每毫克量子点大约可偶联0.14 mg的链霉亲和素。采用荧光光谱研究量子点标记前后的荧光变化,标记后量子点的最大发射波长蓝移了8 nm,而发射光谱的半峰宽基本不变,说明量子点与链霉亲和素结合后粒子没有团聚,分散性好。     

基于铕螯合物纳米粒子标记的时间分辨荧光免疫法检测嗜水气单胞菌

以铕螯合物荧光纳米粒子标记嗜水气单胞菌菌株B15兔抗IgG,得到纳米粒子-IgG复合物,建立了新的嗜水气单胞菌双抗夹心时间分辨荧光免疫检测(TRFIA)法.采用正交试验优化了兔抗IgG的包被时间和包被浓度,以及纳米粒子-IgG的免疫反应时间和稀释度.偶合了铕螯合物的纳米粒子发光强度大,光稳定性高,因此灵敏度被改善.方法...     

生物素标识酶在生物传感器中的应用研究

利用生物素与亲合素之间的特异性结合,在恒电位下,首先将亲合素吸附在电极上,然后使标识在生物素上的葡萄糖氧化酶固定于电极表面,制成具有高活性的多层固定化酶的葡萄糖传感器。电极线性范围:1.0×10^-5～1.0×10^-2mol/L,检测限:6.0×10^-6mol/L,响应时间:6s.本传感器具有线性范围宽、灵敏度高、响应速度快、可反复活化使用等优点。     

生物素-亲和素放大酶联免疫吸附法测定氯胺酮

建立了检测氯胺酮的生物素-亲和素放大酶联免疫吸附测定法(BA-ELISA)。实验最佳测定条件:抗原包被浓度为2.0mg/L、氯胺酮单克隆抗体浓度为10.2mg/L,生物素化羊抗小鼠IgG(Biotin-IgG)和酶标链霉亲和素(SA-HRP)的最佳反应浓度分别为0.29和1.0mg/L。在此优化条件下,方法的线性范围为0.1～1000μg/L;检出限为0.03μg/L。氯胺酮生物样品的加标回收率为94%～102%。与酶标二抗体系ELISA法相比,BA-ELISA具有更高的灵敏度,适于低浓度氯胺酮的检测。     

铕(Ⅲ)激活的磷酸镧发光性质研究

LaPO₄:Eu³⁺的发射光谱包含较强的Eu³⁺⁵D_o→⁷F₁跃迁发射和较弱的⁶D₁→⁷F₁跃迁发射。主发射峰583nm,对应于Eu³⁺5D_o→⁷F₁跃迁.通过对Eu³⁺的两种跃迁发射强度及荧光寿命和Eu³⁺浓度关系的测定和理论分析,探讨了发光中心Eu³⁺离子同的交叉弛豫和能量迁移机理。     

青枯雷尔氏菌特征菌株高效离子交换色谱快速分离条件的优化

建立了高效离子交换色谱和紫外检测系统快速分离青枯雷尔氏菌的细菌色谱方法。通过比较青枯雷尔氏菌悬浮在哌嗪-HCl缓冲体系和双蒸水后的菌体数变化及细胞形态变化,分析该缓冲液对青枯雷尔氏菌生长活性及细胞表面特性的影响。结果表明,青枯雷尔氏菌悬浮在平衡缓冲液、洗脱缓冲液和双蒸水中的菌体数量无明显差异,分别为6.467×10⁹、6.267×10⁹和6.233×10⁹ cfu/mL。透射电镜观察发现,3种溶液处理后,青枯雷尔氏菌均保持完整的细胞结构。研究了缓冲液pH值、流速及菌体细胞浓度对青枯雷尔氏菌色谱分离效果的影响,确定青枯雷尔氏菌的最佳色谱分离条件为：缓冲液pH值为8.0,流速为2 mL/min,菌体浓度大于1.0×10⁸ cfu/mL且小于1.0×10¹⁰ cfu/mL。该分离条件缩短了分离时间,提高了分离效率,为快速分离青枯雷尔氏菌提供了一种有效的手段,同时也为细菌等微生物的分离提供了新途径。     

稀土离子跨人血红细胞膜的荧光法研究

采用Fura-2荧光浓度指示剂对红细胞的稀土跨膜作用进行了系列研究.结果表明,稀土离子不能通过完整的红细胞膜进入细胞内.通过与离子载体实验相对照,发现细胞ATP耗竭后,低浓度的稀土离子(5×10^-6mol/L)不能跨膜进入ATP-耗竭红细胞.KCl去极化及加入电压依赖性钙通道刺激剂Bay-K8644对稀土离子的跨膜也没有促进作用.在Ca²⁺内流正常的情况下,低浓度稀土离子(5×10^-6mol/L)对钙离子内流无影响.增大稀土离子浓度到5×10^-4mol/L,用显微镜观察此时红细胞已开始溶血.在模拟胞内离子组分的缓冲液中(pH=7.05),比较了La³⁺,Eu³⁺和Ca²⁺对Fura-2的敏感程度.此条件下Fura-2对La³⁺和Eu³⁺的检测限分别为10-12和10-14mol/L,对Ca²⁺的检测限为10-8mol/L,并测得Fura-2-La³⁺(Eu³⁺)的络合比为1∶1,表观离解常数为1.7×10^-12和4.95×10^-14mol/L,表明用此法检测稀土离子跨膜行为相当灵敏有效.     

基于核酸适配子识别的荧光法检测可卡因

基于荧光标记和核酸适配子识别可卡因,建立了简单、灵敏的可卡因新型荧光分析法.在微孔板表面组装亲和素-生物素化可卡因适配子-FAM标记可卡因适配子互补短链复合物,根据加入可卡因前后荧光强度的变化来定量可卡因.实验考察了微孔板包被亲和素浓度、生物素标记适配子用量、FAM标记可卡因适配子互补短链用量、反应温度、反应时间等因素...     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.