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101.
pH对丙烯酸-丁烯醛共聚合反应的影响 总被引:3,自引:0,他引:3
具有功能基的聚合物因其所具备的特殊性能而获得越来越多的应用[1] .带醛基的聚合物可在室温下很容易与酶、抗体、抗原、蛋白质、细胞等含氨基的生物高分子反应 ,生成Schiff碱 ,将这些生物高分子共价偶联到聚合物上 ,并能保持它们绝大部分的生物活性 ,因而在免疫分析、生物化学、生物医学等领域有着广泛的应用前景[2~ 4 ] .然而 ,到目前为止 ,带醛基的聚合物的合成研究主要集中在丙烯醛的均聚及共聚反应[5~ 8] ,而对其它不饱和醛的聚合研究报道很少 .但是由于丙烯醛聚合物分子链上相邻的醛基极易形成缩醛或半缩醛而使自由醛基的数量… 相似文献
102.
For point‐of‐care examination, total CK (creatine kinase: adenosine‐5‐triphosphate‐creatine phosphotransferase, EC 2.7.3.2) biosensors were developed and optimized. The biosensors were fabricated with three‐Au‐electrode system modified with polyvinylpyridine‐osmium‐wired horseradish peroxidase (PVP‐Os‐HRP) redox polymer film. The reagents were separately immobilized on the single layer biosensor and double layer biosensor which contained lens paper layer and the surface layer of the working electrode. The mediator, the working potential, the structure of working electrode and the stabilizer agent were studied. The biosensor with double reagent layer showed good stability at room temperature (≥2 months) and the biosensor with single reagent layer had excellent response signal (a sensitivity of 11 nA L U?1 cm?2). 相似文献
103.
Yanxin Wang Dapeng Peng Yufei Zhu Shuyu Xie Yuanhu Pan Dongmei Chen Yanfei Tao Zonghui Yuan 《Journal of separation science》2019,42(10):1915-1929
A facile and sensitive multi‐residue detection approach of pressurized liquid extraction following high‐performance liquid chromatography tandem mass spectrometry was established to detect the residues of adrenergic drugs, steroids, sedative, colorant and antioxidant in feed. The conditions employed for pressurized liquid extraction involved acetonitrile/ethyl acetate (1:1, v/v) as the extracting solvent, the temperature 80°C, two cycles and a static time of 10 min. The extraction was followed by a solid‐phase extraction clean‐up step. The separation of samples was done by C18 column with the mobile phase of 5 mM ammonium acetate solution and acetonitrile with 0.1% formic acid. The limits of quantification ranged from 0.03 to 1 μg/kg, limits of detection were in a range of 0.01–0.5 μg/kg, and average recoveries were 70.4–98.6%. The pressurized liquid extraction procedure was optimized and overall method was validated in terms of sensitivity, linearity, selectivity, matrix effect, accuracy, recovery and stability of the target drugs in the pressurized liquid extraction extracts solution. The screening method was proved to be fast, selective, accurate and sensitive for screening drugs. 相似文献
104.
105.
The dinuclear complex of [Fe2L{O2P(OPh)2}](CIO4)2 ·Et2O(1) (where L represents the dinucleating ligand N-Et-HPTB, anion of N, N, N', N'-tetrakis (N-ethyl-2-benzimidazolyemethyl)-2-hydroxy-1, 3-diamino-propane) has been synthesized and crystallizes in the triclinic space group P T with cell constants α = 1.526(3) nm, b = 1.259 8(3) nm, c = 1.563 0(3) nm , α = 94.41 (3)°, P = 115.31(3)°, β=99.90(3)°, V= 3.267(1) nm3, z=2, R = 0.084 7 and Rw = 0.177 8. The Fe(Ⅱ) sites are bridged by an alkoxide of the dinucleating ligand and a phosphate, affording a diiron core with an Fe-μ-O-Fe angle of 131.20(3)° and an Fe-Fe distance of 0.364 9 nm. Both Fe(II) centers have trigonal bipyramidal geometry. Dioxygen adduct (1/O2) forms upon exposure of the diferrous complex to O2 at low temperature (-60℃). The 1/O2 adduct is stable at -60℃ but decomposes upon warming. The adduct exhibits visible absorption maximum near 606 nm and resonance Raman features at 478 cm-1 (γFe-o) and 897 cm-1 (γo-o), and the latter 相似文献
106.
Lei Zhang Shiping Yan Chunhui Li Daizheng Liao Zonghui Jiang Peng Cheng Genglin Wang Linhong Weng Xuebing Leng 《Journal of chemical crystallography》2000,30(4):251-254
A tetranuclear manganese (IV) complex, [L4Mn4O6](ClO4)4·2H2O (1), with 1,4,7-triazacyclononane (L) as the capping ligands, has been synthesized and characterized by X-ray diffraction; monoclinic, space group P21/n with a = 21.335(6) Å, b = 11.387(3) Å, c = 21.788 (6) Å, = 111.410 (6)°, V = 4928 (2) Å, Z = 4. Each manganese atom has a distorted octahedral environment comprised of three facially coordinated amine nitrogen atoms and three oxygen atoms, and the cation is an idealized tetrahedron. The Mn4O6
4+ cation corresponds to an adamantane skeleton. 相似文献
107.
Yemin Xue Zonghui Zhang Jingjing Hou Zhigang Cao Lingxian Zhang Fen Lou 《Journal of carbohydrate chemistry》2013,32(7-8):414-430
AbstractFor preparation of resveratrol and arctigenin from peanut hulls and arctium lappa fruits, respectively, a recombinant β-glucosidase (TmBglA) from hyperthermophile Thermotoga maritima was purified and characterized. The hydrolytic activity was the highest at 90?°C and pH 6.2 for arctiin with Km of 1.61?mM and kcat of 197.4?s?1, and 90?°C and 5.8 for polydatin with Km of 0.38?mM and kcat of 47.6?s?1. The enzyme produced 215.4?mg L?1 resveratrol and 355.7?mg L?1 arctigenin from 400?mg L?1 polydatin and 540?mg L?1 arctiin after 60?min of incubation at 80?°C, with capable of hydrolyzing up to 92.1 and 94.9% of polydatin and arctiin, respectively. The enzymatic hydrolysis of peanut hulls and fructus arctii displayed a conversion yield of 3.8 and 0.33?mg resveratrol and arctigenin per gram of substrate material flour, respectively. Of the reported β-glucosidase, TmBglA exhibited the highest thermostability, kcat, kcat/Km, and conversion productivity for hydrolyzing polydatin and arctiin, and has great potential applications in functional food and medicine production. 相似文献