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991.
应用原子吸收分光光度法对济南市健康老年人血清中铜、锌、镁含量进行了测定。结果表明,健康老年人血液铜、锌水平低,但铜、锌比值正常,而镁的含量则较高。提示这组健康老年人未患心、脑血管疾病及糖尿病的原因可能与铜、锌、镁等微量元素有关。 相似文献
992.
Kurosaki H Yasuzawa H Yamaguchi Y Jin W Arakawa Y Goto M 《Organic & biomolecular chemistry》2003,1(1):17-20
A fluorescent probe for the detection of a metallo-beta-lactamase (IMP-1), N-[2-(5-dimethylaminonaphthalen-1-ylsulfonylamino)ethyl]-3- mercaptopropionamide (Dansyl-C2SH), 1, was designed based on combining the inhibitory function of mercaptocarboxylate and a fluorophore. The binding of 1 to IMP-1 was investigated by fluorescence spectroscopy. Compound 1 can act as fluorescent probe for detecting IMP-1 selectively. 相似文献
993.
用红外光谱、X射线衍射(XRD)和热分析研究了饱和过渡金属锌的粘土矿物吸附半胱氨酸的机理;XRD结果显示吸附了半胱氨酸后的粘土矿物的d(001)方向的距离明显增大,说明被吸附的半胱氨酸进入了粘土的层状结构之中;饱和了锌的粘土矿物吸附半胱氨酸有两种方式,其一为弱相互作用,另一种强相互作用;后一种方式吸附的半胱氨酸与粘土的过渡金属之间形成了配合结构,结合力比较强,在热作用下,它们一直到395℃左右才分解;强相互作用吸附的半胱氨酸主要是以去质子的两性离子和阴离子形式存在于粘土矿物上,与过渡金属形成螯合的六元环结构。 相似文献
994.
995.
合成了β-芳氧基丙酸芳酯及β-芳氧基丙酰芳胺等17种化合物,经IR,UV,HNMR和元素分析确定了它们的结构,并对它们的生物活性进行了初步考察。 相似文献
996.
CTMAB胶束体系中反离子缔合度的测定 总被引:2,自引:0,他引:2
对十六烷基三甲基淡化按(CTMAB)水胶束体系,不同方法测得其反离子缔合度产值不同【‘-\且很高于由股团电化学理论所得q值0.67问.本文以离子选择性电极法测定CTMAB水胶束体系中反离子缩合度(仁0.65),并研究了外加盐和乙醇的影响·1实验部分1.工试剂和仪器十六烷基三甲基漠化技(CP)在无水乙醇中重结晶两次,纯化物经帕环法测其表面张力在CMC附近无最低声、·淡化钾(AR),水为。次蒸馏水,PXJIC型离子计,302型PB,电极(响应范围为PB,=1.6~3.3,响应时间为5分钟)222型甘汞电极·1.2实验方法在CMCV/de的稀… 相似文献
997.
Wei Jun Jin 《Analytica chimica acta》2004,522(1):1-8
Luminescent surface-modified CdSe semiconductor quantum dots (QDs), with nanoparticle (NP) size distribution in the order of 2-7 nm, have been synthesized for optical determination of cyanide ions. The nanoparticles have been functionalised with tert-butyl-N-(2-mercaptoethyl)-carbamate (BMC) groups and exhibit a strong fluorescent emission at about 580 nm with rather long fluorescence lifetimes (several hundred nanoseconds) in aerated methanolic solution. The observed luminescence emitted by the synthesized nanocrystals was tremendously increased by photo-activation under sunlight exposure. The functionalised QDs turned out to exhibit excellent long-term stability when stored in the dark (no significant changes in QDs luminescence emission intensity was observed even after two months from synthesis). The functionalisation of the NPs with carbamate ligand allowed a highly sensitive determination of free cyanide via analyte-induced changes in the photoluminescence (fluorescence quenching of intensity at 580 nm and lifetime changes) of the modified quantum dots (excited at 400 nm). A detection limit of 1.1 × 10−7 M (2.9 μg l−1) of cyanide ions was obtained, while the interfering effect of other inorganic anions (including NO3−, Cl− or SCN−) was negligible even at 200-fold level concentrations in excess of cyanide. 相似文献
998.
The mouse immunoglobulin G (mouse IgG) as a kind of bio-molecule was labeled with two different luminescent colloidal semiconductor quantum dots (QDs), green-emitting CdTe quantum dots and red-emitting CdTe quantum dots in this work. As a result of the fluorescence resonance energy transfer (FRET) between the two different sizes nanoparticles with mouse IgG as the binding bridge, a significant enhancement of the emission of the red-emitting CdTe quantum dots and the corresponding quenching of the emission of green-emitting CdTe quantum dots were observed. The relationship between the concentration of the mouse immunoglobulin G and the fluorescence intensity ratio (Ia/Id) of acceptors and donors was studied also. Under optimal conditions, the calibration graph is linear over the range of 0.1–20.0 mg/L mouse IgG. 相似文献
999.
The alkyl (aryl)-bishydroxymethylphosphines react with primary amines to give the title compounds. With optically active amines optically active phosphines are formed. 相似文献
1000.
A new highly selective silver(I) electrode was prepared with a PVC membrane using 5,10,15-tris(pentafluorophenyl)corrole as an electroactive material, 2-nitrophenyl octyl ether (o-NPOE) as a plasticizer and sodium tetraphenylborate (NaTPB) as an additive in the percentage ratio of 3:3:62:32 (corrole:NaTPB:o-NPOE:PVC, w:w). The electrode exhibited linear response with a near Nernstian slope of 54.8 mV/decade within the concentration range of 5.1 × 10−6 to 1.0 × 10−1 M silver ions, with a working pH range from 4.0 to 8.0, and a fast response time of <30 s. Selectivity coefficients for Ag(I) relative to a number of interfering ions were investigated. The electrode is highly selective for Ag(I) ions over a large number of mono-, bi-, and tri-valent cations. Common interferents like Hg2+ and Cd2+ show very low interfering effect on the silver assay, which is valuable property of the proposed electrode. Several electroactive materials and solvent mediators have been compared and the experimental conditions were optimized. The sensor was applied to the determination of silver in real ore samples with satisfied results. 相似文献