人红细胞摄入Cd2+离子的动力学和机理

不同Cd²⁺离子浓度引起的人红细胞相对溶血率及临界溶血浓度CH⁰已经测定,CH⁰=2.5×10^-4mol·L^-1。Cd²⁺跨膜进入人红细胞遵从一级动力学过程,其一级速率常数为1.2×10^-2h^-1。阴离子通道抑制剂DIDS及K⁺,Na⁺-ATPase抑制剂均可部分抑制人红细胞摄入Cd相似文献   

人红细胞摄入 Eu(Cit)23-阴离子通道机制的研究

研究了Eu(Cit)2^3-进入人红细胞的机制。在人红细胞与含不同浓度的Eu(Cit)2^3-的等渗缓冲液温育后。用ICP－MS测定胞浆及膜中Eu的含量，并考察了阴离子通道抑制剂DIDS，温度及pH的影响，制备了人红细胞膜正面向外囊泡（ROV）和内翻包囊泡（IOV）并研究了它们对Eu(Cit)2^3-的摄取及DIDS的影响。结果表明，Eu(Cit)2^3-可以与细胞膜结合并进入红细胞内，DIDS强烈抑制红细胞对Eu(Cit)2^3-的摄入；温度，pH对细胞摄入有显著影响，ROV和IOV可以摄入Eu(Cit)2^3-，但DIDS只抑制ROV的摄入，对IOV的摄入无影响。Eu(Cit)2^3-进入人红细胞具有阴离子通道机制的各种特征。阴离子通道是稀土柠檬酸络合物Eu(Cit)2^3-进入红细胞的途径之地。     

方波吸附溶出伏安法同时测定水中痕量铜和镉

报道了应用方波吸附溶出伏安法 (OSWSV)同时测定Cu(Ⅱ )和Cd(Ⅱ )。在 0 .0 1mol·L- 1酒石酸钾钠 2 .0× 10 - 4mol·L- 1水杨醛肟溶液中 (pH 11.75 ) ,Cu(Ⅱ )和Cd(Ⅱ )分别与水杨醛肟形成的络合物均产生非常灵敏的还原波 ,峰电位分别为 - 0 .5 5 6V和 - 0 .70 4V (vs.Ag/AgCl以下均同 )。峰电流与Cu(Ⅱ )、Cd(Ⅱ )浓度分别在 9.0× 10 - 74 .0× 10 - 8mol·L- 1和 2 .0× 10 - 6 6 .0×10 - 8mol·L- 1范围内呈线性关系 ,检出限均为 1.0× 10 - 8mol·L- 1。该法用于同时测定水样中痕量Cu(Ⅱ )和Cd(Ⅱ ) ,所得结果满意。通过对该体系的初步研究 ,Cu(Ⅱ )、Cd(Ⅱ )与水杨醛肟形成的络合物的还原峰具有明显的吸附性。     

四种阴离子的毛细管电泳电导检测(英文)

 采用柠檬酸 柠檬酸钠作为缓冲体系 ,使用负高压 ,对Cl-,NO3 -,HCO3 -和H2 PO4 -等 4种常见阴离子进行了分离检测 ,研究了缓冲剂的种类、浓度、pH值及操作电压对分离的影响。在选定的条件下 ,4种离子的定量线性范围 :Cl-5 0× 10 -5mol/L～ 2 5× 10 -3 mol/L ,NO3 -6 0× 10 -5mol/L～ 2 0× 10 -3 mol/L ,HCO3 -5 0× 10 -6mol/L～ 2 0× 10 -4 mol/L ,H2 PO4 -6 0× 10 -5mol/L～ 1 0× 10 -3 mol/L ;检出限 :Cl-1 5× 10 -5mol/L ,NO3 -3 0×10 -5mol/L ,HCO3 -1 0× 10 -6mol/L ,H2 PO4 -2 0× 10 -5mol/L ;峰面积的RSD (n =6 ) :Cl-3 1% ,     

同一体系中铜(Ⅱ)、铅(Ⅱ)、镉(Ⅱ)、镍(Ⅱ)和钴(Ⅱ)的络合物吸附波及其分析应用

研究了丁二酮肟 氨 氯化铵 柠檬酸钠 明胶 抗坏血酸体系中Cu(Ⅱ )、Pb(Ⅱ )、Cd(Ⅱ )、Ni(Ⅱ )和Co(Ⅱ )的络合物吸附波 ,建立了同时测定水溶液中痕量相应元素的新方法。上述金属络合物分别在 -0 .44、-0 60、-0 .76、-1.0 7和 -1.2 4V左右产生灵敏的极谱波。信噪比为 3时 ,检出限分别为 1.0× 10 - 8、2 .3×10 - 8、1.3× 10 - 8、2 .9× 10 - 1 0 和 3 .6× 10 - 1 1 mol/L。铜、铅、镉、镍和钴的浓度分别为 2 .0× 10 - 8～ 2 .0× 10 - 5,4.8× 10 - 8～ 4.8× 10 - 5,3 .0× 10 - 8～ 3 .0× 10 - 5,5 .4× 10 - 1 0 ～ 5 .4× 10 - 7和 6.8× 10 - 1 1 ～ 6.8× 10 - 8mol/L时 ,与相应峰电流线性关系良好。方法用于同时快速测定实际样品中这些金属离子 ,获得满意结果     

N-甲基吡咯烷酮与HnXMo12O40·mH2O(X=P,Si,Ge)电荷转移盐的合成、表征及非线性光学性质

由 N-甲基吡咯烷酮 (NMP)和 Hn XMo1 2 O40 · m H2 O(X=P,Si,Ge)合成了具有非线性光学性质的电荷转移盐 ,(NMPH ) 3PMo1 2 O40 · CH3CN ( ) ,(NMPH) 4Si Mo1 2 O40 · CH3CN ( )和(NMPH) 4Ge Mo1 2 O40 · CH3CN( ) ,并以元素分析 ,红外光谱 ,漫反射电子光谱进行了表征 .结果表明 ,杂多酸形成电荷转移盐后其阴离子结构未变 ;N-甲基吡咯烷酮通过 N原子与酸中的质子H 结合成阳离子而成盐 ,在高压汞灯照射下阴阳离子之间可以发生电荷转变 .非线性光学性质研究表明 ,电荷转移盐的倍频效应强度分别为 I2ω =0 .3IKDP,I2ω =0和 I2ω =0 .0 2 IKDP,三阶非线性系数分别为χ( 3) =5 .0× 10 - 1 4 esu,χ( 3) =3.1× 10 - 1 3esu和χ( 3) =4.3× 10 - 1 3es     

微流控芯片上的红细胞电泳淌度研究

以单细胞成像法分别测量了 3组无农药含水质净化剂、有农药无水质净化剂及其有农药有水质净化剂处理后的杂交鲤鱼红细胞在塑料 ( polymethalmethacrylate ,PMMA)微流控芯片上的电泳淌度。其值分别为 1.138× 10 -4、0 .12 79× 10 -4和 - 0 .85 2 0× 10 -4cm2 v-1s-1。从电泳淌度的差别可以看出功夫菊酯和水质条件恶化均可使鲤鱼红细胞表面的电荷密度发生变化 ,从而引起电泳淌度的变化。同时还初步考察了细胞电泳淌度作为参数进行细胞分类的可行性 ,显示这种淌度差别有可能作为细胞分类的一项依据     

钴氢氧化物修饰玻碳电极的镀膜/循环伏安法制备及其电化学行为

采用一种新方法镀膜 /循环伏安法成功制备了钴氢氧化物修饰玻碳电极 .考察了影响钴氢氧化物膜电催化活性的因素 ,确定最佳富集时间为 2min ,最佳活性单元浓度为 9 90× 10 -4mol·L-1.讨论了成膜过程及机理 .膜氧化峰电流 (i0pa)与扫描速率 (v <0 60V·s-1)成正比 ,具有表面吸附反应特征 ,表面覆盖量约相当于 0 5个单层的氧化还原活性物质 .制得的钴氢氧化物膜修饰电极具有相当的稳定性 ,并对H2 O2 氧化表现出较高的电催化活性 .线性回归方程为 :Δipa( μA) =-2 10 3 6+2 3 72 0× 10 4CH2 O2 (mol·L-1) (R =0 9990 ,n =18) ,线性范围为 :1 43× 10 -5～ 1 80× 10 -2 mol·L-1,检出限为 :9 5 9× 10 -6mol·L-1( 3S/k) .     

阻抑褪色光度法测定水样中阴离子表面活性剂

在弱酸性的HCl-NaOAC缓冲介质中,溴化十六烷基吡啶(CPB)和曙红Y(EY)染料的混合溶液发生褪色,在该褪色的溶液中分别加入十二烷基硫酸钠(SDS)及十二烷基苯磺酸钠(SDBS)等阴离子表面活性剂(AS),溶液颜色发生改变,最大吸收波长都在514 nm处,并分别在548、546 nm处产生明显褪色。在吸收或褪色波长处,阴离子表面活性剂的浓度与增色或褪色程度呈良好线性关系,从而建立测定阴离子表面活性剂的光度法。在最大吸收波长处,SDBS体系、SDS体系中AS的浓度在0~2.06×10-5mol/L、0~2.63×10-5mol/L范围内遵守比尔定律,表观摩尔吸光系数分别为1.30×104、1.01×104L.mol-1.cm-1,检出限分别为8.14×10-7、9.96×10-7mol/L。若用双波长叠加,表观摩尔吸光系数达2.07×104、1.78×104L.mol-1.cm-1,检出限为4.82×10-7、8.34×10-7mol/L。方法具有较高的灵敏度和良好的选择性,用于水样中AS的测定。     

镉（Ⅱ）—4—甲醛基重氮氨基偶氮苯显色反应的研究

本文研究了Cd(Ⅱ)与4-甲醛基重氮氨基偶氮苯的显色反应。试验结果表明:在TritonX-100的存在下,pH9.50的Na_2B_4O_7-NaOH缓冲体系中,显色反应的灵敏度高,络合物的最大吸收峰在525nm处,表观摩尔吸光系数为1.33×10~5L·mol~(-1)·cm~(-1),Cd(Ⅱ)浓度在0～10μg/25ml范围内符合比耳定律。利用阴离子交换树脂(717)小柱分离干扰离子后,测定地质试样中微量镉,结果满意。     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Calculation of enthalpies of hydrogenation of hydrocarbons

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.