Background-free,fast protein staining in sodium dodecyl sulfate polyacrylamide gel using counterion dyes,zincon and ethyl violet

A background-free, fast protein staining method in polyacrylamide gel electrophoresis using an acidic dye, zincon (ZC) and a basic dye, ethyl violet (EV) is described. It is based on the counterion dye staining technique that employs two oppositely charged dyes to form an ion-pair complex in staining solution. The selective binding of free dye molecules to proteins in acidic solution produces bluish violet-colored bands. It is a rapid and end-point staining procedure, involving only fixing and staining steps that are completed in 1-1.5 h. The detection limit of this method is 8-15 ng of protein that is comparable to the sensitivity of the colloidal Coomassie Brilliant Blue G (CBBG) stain. Due to its sensitivity and speed, this stain may be more practical than any other dye-based stains for routine laboratory purposes.     

Counterion Exchange Selectivity in Detergent–Polymer Aggregates

In aqueous solution, the interaction between sodium dodecyl sulfate (SDS) and poly(ethylene glycol) (PEG) results in the formation of small aggregates or clusters of SDS attached to the PEG polymer chain. Selectivity coefficients for exchange of two monovalent (N-methyl-4-cyanopyridinium cation and Tl⁺) and two divalent (methylviologen cation and Cu²⁺) counterions at the surface of SDS–PEG clusters, determined employing photophysical techniques, are similar, but not identical, to those for exchange at the surface of SDS micelles in the absence of PEG. The principal factor affecting ion exchange selectivity in SDS–PEG clusters does not appear to be aggregate size or surface charge density but rather the presence of poly(oxyethylene) subunits at the aggregate surface.     

银微电极微分电位溶出分析法研究

本文首次报道了银微电极微分电位溶出分析法。用化学刻蚀法方便地制作了银微电极，用于ＤＰＳＡ具有背景值低，分辨率好、精密度及灵敏度高，在不搅拌，仅需一定酸度而酸度而无其它介质的条件下就能测试等优点，对人工试样及自来水样分析，结果令人满意。     

Microemulsion photopolymerization of methacrylates stabilized with sodium dodecyl sulfate and poly(N-acetylethylenimine) macromonomers

Methyl methacrylate and butyl methacrylate were polymerized in oil-in-water microemulsions that were stabilized by sodium dodecyl sulphate (SDS). A poly(N-acetylethylenimine) (PNAEI) macromer was also included in the recipe, as a cosurfactant and a comonomer. Polymerizations were initiated by UV-irradiation. The average diameters of latex particles, obtained by STM, were in the range of 17-200 nm. The experimental data evidenced that the particle size was mainly dependent on the SDS/PNAEI ratio. Polymerization yields were around 75-85%. The synthesized copolymers have viscosity average molecular weights in the range of 2.1-2.4×10⁶ and glass transition temperatures of 38.0-43.5°C, lower than those obtained without using PNAEI. The investigation by means of FTIR and 1H-NMR techniques revealed that PNAEI was incorporated into the nanoparticles.     

烷基硫酸钠对MMA种子乳液聚合的影响

研究了烷基硫酸钠纯度，烷基碳链分布对甲基丙烯酸甲酯种子乳液聚合反应的影响。结果表明，烷基硫酸钠中乙醇不溶物含量的增加，可提高ＭＭＡ乳液聚合反应速度，在采用Ｋ２Ｓ２Ｏ８－ＮａＨＳＯ３－Ｃｕ＾２＋三元氧化－还原引发体系的ＭＭＡ乳液聚合中，Ｆｅ＾２＋降低反应速率，而Ｆｅ＾３＋则提高聚合反应速率；     

Syntheses and X-Ray Crystal Structures of 2-Aminoindenes and Aminocymantrenes

Substituted 2-aminoindenes have been synthesized in almost quantitative yields by reactions of amines such as methylpiperazine, trimethylethylenediamine, 1,4-diaza-cycloheptane and N,N′-dimethylethylenediamine with 2-indanone. The 2-aminoindenes can be deprotonated and reacted with BrMn(CO)₃(Py)₂ to produce the respective aminoindenyl-cymantrenes in yields between 55–70%. The X-ray crystal structures of 2-(methylpiperazine)indenyl-cymantrene 5 (P1 , a = 12.667(3) Å, b = 16.630(3) Å, c = 17.382(3) Å, α = 72.70(3)°, β = 74.59(3)°, γ = 88.66(3)°, V = 3364.1(12) Å ³, Z = 8, R1(2σ(I)) = 4.02%, wR2(2σ(I)) = 10.30%) and the HClO₄ adduct of 2-(trimethylethylenediamine)-indenyl-cymantrene 6 (Cc, a = 23.722(5) Å, b = 6.9080 Å, c = 13.264 Å, β = 111.77(3)°, V = 2018.6(7) Å 3, Z = 4, R1(2σ(I)) = 2.94%, wR2(2σ(I)) = 7.90%) were determined. In both complexes the indenyl-carbon bonded to nitrogen displays significantly longer bonds to manganese [223.5(3)–225.8(3) pm] than the other four carbon atoms [213.3(3)–219.1(3) pm]. The short indenyl-nitrogen bonds of 136.2(4) and 137.8(4) pm are indicative of a substantial multiple bond character. The complexation of Zn²⁺ by the nitrogen atoms of 6 results in significant shifts of the CO stretching frequencies.     

硫胺的燐光研究

硫胺无燐光，在碱中氧化后才产生燐光。 λ激发＝３００ｎｍ，λ发射＝４１０ ｎｍ，燐光寿命为１．３ｓ．硫胺燐光受溶剂极性影响甚小，１５种金属离子中只有铜离子可增强流胺燐光，寿命变短为 ０． ９４ ｓ，但不影响燐光光谱。在开始３０ｍｉｎ内有ＣｕＳＯ４的作用较快，以后逐渐变慢，到 ４ｈ后达平衡与不用ＣｕＳＯ４的燐光相近，启示ＣｕＳＯ４具有催化硫胺的氧化作用，建立了硫胺的燐光分析方法，用于两种维生素Ｂ１片的分析，分别为９８．５％与９８％。     

微量元素对胎儿发育影响的临床研究

为了解小于胎龄儿的血锌、铜、铅的变化 ,对 3 8例小于胎龄儿 (其中 1 2例有先天缺陷 )进行了血锌、铜、铅三种微量元素检测 ,并与 3 1例健康足月适于胎龄儿比较。结果表明 ,3 8例小于胎龄儿血锌、铜、铅结果分别为 49 4± 1 9 88μmol/L、 1 0 7± 3 3 μmol/L、 1 5± 0 83 μmol/L ;与正常对照组 (分别为 62 3 9± 1 5 2 9μmol/L、 1 1 0 2± 1 73 μmol/L、 0 82± 0 3 9μmol/L)比较 ,血锌明显低于正常组 ,t=-2 88,P <0 0 1 ;血铅明显高于对照组 ,t =4 6,P <0 0 1 ,有显著性差异。两组血铜无明显差异。小于胎龄儿血锌降低 ,血铅增高 ,而且其先天性缺陷者占3 5 .5 8% ,证明胎儿的低锌高铅状态对其生长发育有重要影响。     

Cellulose hydrolysis using zinc chloride as a solvent and catalyst

Cellulose gel with < 10% of crystallinity was prepared by treatment of microcrystalline cellulose, Avicel, with zinc chloride solution at a ratio of zinc chloride to cellulose from 1.5 to 18 (w/w). The presence of zinc ions in the cellulose gels enhanced the rate of hydrolysis and glucose yield. The evidence obtained from X-ray diffraction, iodine absorption experiments; and Nuclear Magnetic Resonance spectra analysis suggested the presence of zinc-cellulose complex after Avicel was treated with zinc chloride. Zinc-cellulose complex was more susceptible to hydrolysis than amorphous cellulose. Under the experimental condition, cellulose gels with zinc ions were hyrolyzed to glucose with 95% theoretical yield and a concentration of 14% (w/v) by cellulases within 20 h. The same gel was hydrolyzed by acid to glucose with 91.5% yield and a concentration of 13.4% (w/v).     

Structure determination of zinc iodide complexes formed in aqueous solution

Structures of the complexes formed in aqueous solutions between zinc(II) and iodide ions have been determined from large-angle X-ray scattering, Raman and far-IR measurements. The coordination in the hydrated Zn²⁺ hexaaqua ion and the first iodide complex, [ZnI]⁺, is octahedral, but is changed into tetrahedral in the higher complexes, [ZnI₂(H₂O)₂], [ZnI₃(H₂O)]^– and [ZnI₄]^2–. The Zn-I bond length is 2.635(4)Å in the [ZnI₄]^2– ion and slightly shorter, 2.592(6)Å, in the two lower tetrahedral complexes. In the octahedral [ZnI(H₂O)₅]⁺ complex the Zn-I bond length is 2.90(1)Å. The Zn-O bonding distances in the complexes are approximately the same as that in the hydrated Zn²⁺ ion, 2.10(1)Å.