基于微流控芯片电泳分离双链DNA片段的新方法研究

近年来,随着微流控芯片分析技术的兴起,微芯片电泳技术在DNA片段的分离和测序方面的应用也越来越频繁.利用微流控芯片较为成熟的加工技术,建立可以应用于基因测序方面的DNA片段的分离方法研究具有积极意义.     

微流控芯片液-液萃取-气相色谱联用系统的研究

微流控芯片多相层流技术自Yager等^[1]首次报道以来,已广泛应用于芯片上无膜渗析、过滤和萃取等前处理过程.2000年,Kitamori等^[2]报道了基于多相层流原理的芯片上液-液萃取系统,利用在微通道内形成并行流动的有机相和水相层流体系,通过溶质在液流间的分子扩散作用完成无膜的萃取分离操作.     

微流控芯片微孔膜液-液萃取系统

微流控芯片(Microfluidic chip)是微全分析系统(MTAS)研究中最为活跃的领域和发展前沿,在仪器微型化方面展现出很多优点^[1].Kitamori等^[2,3]根据多相层流无膜扩散分离技术建立了芯片上的微流控液-液萃取分离系统,对芯片上的液-液萃取方法进行了系统的研究.     

聚二甲基硅氧烷/玻璃微流控芯片永久性粘合方法及其微通道表面改性研究及其应用

近年来,聚二甲基桂氧烷[Poly(dimethylsilloxane),PDMS]基质微流控芯片因其透光性能好,价格便宜,加工容易,适合大规模生产,成为微全分析系统(Micro total analysis system,μ-TAS)发展的一个热点^[1].PDMS易于复制微通道形状,且具有较高的保真度,省去了玻璃芯片刻蚀的复杂过程;而玻璃具有易于集成功能单元,散热性能好的优点,PDMS-玻璃杂合微流控芯片同时结合了PDMS和玻璃的优点,具有良好的发展前景^[2].     

微流控芯片电化学检测单细胞分析

微流控芯片已被用于进行各种细胞分析的研究.最近,方肇伦等^[1]用十字型微流控芯片压力进样,激光诱导荧光检测进行了人单个血红细胞内谷胱甘肽的测定.用双T型微流控芯片电化学检测方法对小麦愈伤组织中抗坏血酸(AA)的单细胞分析进行了研究.     

在线衍生微流控芯片电泳和激光诱导荧光法测定单细胞中谷胱甘肽

微流控分析芯片的网络结构和微米通道尺寸适合于单细胞进样、控制和分离分析^[1~4].在测定细胞内容物时,大多采用柱前细胞内衍生法^[1,2,4],但操作复杂,需多次离心分离,且能透过细胞膜标记胞内组分的荧光试剂较少.     

基于复合型微流控芯片的紫外检测电泳分析系统的优化及应用

我们^[1]于2002年提出了复合型微流控芯片的紫外检测电泳分析系统.该系统具有简单可行和通用性好等优点,但也存在分离效果不佳的缺点..     

玻璃-PDMS复合芯片微流控气动微阀的研制

报道了一种基于玻璃-PDMS复合芯片微流控气动微阀的制作方法,该方法较Unger等^[1]的方法更为简单易行,并克服了PDMS芯片气动微阀刚性不足和与外流路连接困难的缺点,提高了微阀的可靠性.     

一种简单的微流控芯片正交型激光诱导荧光检测系统

对微流控芯片检测技术的研究一直是近年来微全分析系统领域的研究热点.激光诱导荧光(Laser induced fluorescence,LIF)检测技术因其具有较高的灵敏度,成为目前微流控分析芯片采用最广的检测方法^[1].     

芯片式流通池顺序注射化学发光法测定水中的亚硝酸根

微流控芯片(Microfluidic chips)是微全分析系统(μTAS)研究中最为活跃的领域,在仪器微型化方面展现出很多的优点^[1].化学发光由于其自身的特性在微芯片检测中应用逐渐增多^[2,3].     

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%.     

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.     

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.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

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.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.