分子动力学模拟研究纳米碳管中甲醇-水混合溶液的结构与输运性质

利用分子动力学模拟方法,对比考察了平衡条件、外压作用、梯度电场作用下,摩尔比为1:1的甲醇-水混合溶液在纳米碳管(CNT)中的静态结构以及输运行为.研究发现:在平衡体系与外压作用下,纳米碳管内甲醇与水呈现出明显的不混溶现象,甲醇主要分布于管壁附近,水分子主要分布于纳米碳管轴心附近;而在梯度电场作用下,纳米碳管由疏水性向亲水性转变,更多的水分子分布于管壁,导致纳米碳管内甲醇-水的不混溶现象消失.另一方面,在外压作用下,纳米碳管内甲醇与水呈现单向移动;而在梯度电场下,甲醇与水呈现快速的双向移动,其流通量较相应外压作用体系高出近一个数量级,但由于双向的流通量大小相近,导致净流通量与外压作用下的净流通量差异不大.     

肝炎患儿发锌,铜,铅,镉含量的分析

采用闰溶出法测定８２例肝炎患儿的头发中锌,铜,铅,镉含量。结果显示,大多数急,慢性肝炎患儿发锌含量降低;发铜增高者仅占１／４和１／８,肝慢性肝炎中发铜降低者红占１／３,为急性肝炎的３倍;     

再生障碍性贫血患者中药治疗前后微量元素变化初步观察

对20例再生障碍性贫血患者（以下简称再障）头发中12种微量元素的含量进行测定，与正常人做对照，结果发现，阴虚型患者锂、钙、锶、铬显著减少，阴虚型患者锌、镁、钡、钙、锂明显下降，阴阳俱虚型患者则12种元素均减少，并对本院治疗再障贫血的24味中药的微量元素的含量也进行测定。结合微量元素变化对指导再障的辩证组方和辩证施治提供新的思路，同时系统观察再障贫血10例治疗前后微量元素的变化情况，从微量元素角度探求再障的发症因素，认为与部分微量元素缺乏有关，补充相关的微量元素，再障患者可恢复健康。     

Comparison of modifiers for determination of arsenic, antimony and selenium by atomic absorption spectrometry with atomization in graphite tube or hydride generation and in-situ preconcentration in graphite tube

The study was performed to compare the effect of magnesium modifier (magnesium nitrate) with that of other modifiers (palladium nitrate and nickel nitrate) in determination of arsenic, antimony and selenium by atomic absorption spectroscopy with atomization in a graphite tube, with generation of hydrides and in situ preconcentration in a graphite tube. The assumed criterion of a modifier performance was the magnitude of the analytical signal. It was found that in determinations with atomization in a graphite furnace the effects of all these modifiers were comparable, while in those with hydride generation and in situ preconcentration in a graphite tube the magnesium modifier showed poorer performance (25% decrease of the analytical signal). In determinations of arsenic and selenium the analytical signal obtained with magnesium salt as a modifier was comparable with those obtained in the presence of all other modifiers.     

金蒲抑瘤片在鼻咽癌的临床应用研究

为探讨鼻咽癌患者放疗期间合并应用金蒲抑瘤片治疗对细胞免疫功能及血中微量元素硒、锌、铜的影响，经病理证实鼻咽癌患者58例，随机分为放疗服药组30例和单纯放疗组28例。两组放疗前后抽静脉血测定T细胞亚群（CD3＋，CD4＋，CD8＋，CD4＋／CD8＋），血中微量元素硒，锌，铜并与30例健康者（正常对照组）进行比较。结果表明，鼻咽癌患者血中微量元素硒，锌，铜及CD3＋，CD4＋，CD4＋／CD8＋显著低于健康人，放疗期间合并应用金蒲抑瘤片治疗后血中微量元素硒，锌，铜及CD3＋，CD4＋，CD4＋／CD8＋较服药前显著升高。提示鼻咽癌患者细胞免疫功能低下，血中微量元素硒，锌，铜显著低于健康人。金蒲抑瘤片能提高鼻咽癌患者因中微量元素硒，锌，铜含量，使低下的细胞免疫功能迅速恢复。     

血镁水平与糖尿病肾病

为探讨糖尿病肾病 (DN)患者血镁水平 ,以 1 5 9例 2型糖尿病 (T2DM)患者为研究对象 ,用xylidylblue比色法测定了其正常白蛋白尿期、微量白蛋白尿期 (早期DN)、临床DN及晚期DN血镁水平 ,与 2 0例正常对照组相比较 ;同时将 1 1 0例DN患者分为肾功能不全代偿组、失代偿组和肾功能衰竭组 ,将其血镁水平与 1 0 2例慢性肾小球肾炎 (CGN)患者相比较 ,组间比较采用t检验 ;对 79例T2DM正常白蛋白尿期及微量白蛋白尿期患者尿白蛋白排泄率 (UAER)与血镁水平进行了等级相关分析。结果表明 ,T2DM正常白蛋白尿期、早期DN及临床DN血镁水平降低 ,晚期DN血镁水平升高 ,各组与正常对照组相比存在显著性差异 (P <0 0 5或P <0 0 1 ) ;T2DMDN及CGN肾功能不全代偿期、失代偿期及肾功能衰竭期血镁水平渐升高 ,且肾功能处于同一期的DN和CGN相比 ,前者血镁水平均较后者显著降低 (P <0 0 1或P <0 0 5 ) ;T2DM正常白蛋白尿期和微量白蛋白尿期血镁水平与UAER呈负相关 (r=0 5 47,P <0 0 1 )。提示T2DM患者肾功能正常时存在低镁倾向 ,但晚期DN血镁水平升高 ;随着肾功能不全进展 ,DN和CGN患者血镁水平升高 ,但前者血镁水平仍较后者低 ,镁代谢紊乱与DM及其并发症的相互关系有待进一步研究 ;血镁水平测定可否作为DN的早期诊断指标亦     

分子动力学模拟研究纳米碳管中甲醇-水混合溶液的结构与输运性质

利用分子动力学模拟方法,对比考察了平衡条件、外压作用、梯度电场作用下,摩尔比为1：1 的甲醇-水混合溶液在纳米碳管（CNT）中的静态结构以及输运行为. 研究发现：在平衡体系与外压作用下,纳米碳管内甲醇与水呈现出明显的不混溶现象,甲醇主要分布于管壁附近,水分子主要分布于纳米碳管轴心附近;而在梯度电场作用下,纳米碳管由疏水性向亲水性转变,更多的水分子分布于管壁,导致纳米碳管内甲醇-水的不混溶现象消失. 另一方面,在外压作用下,纳米碳管内甲醇与水呈现单向移动;而在梯度电场下,甲醇与水呈现快速的双向移动,其流通量较相应外压作用体系高出近一个数量级,但由于双向的流通量大小相近,导致净流通量与外压作用下的净流通量差异不大.     

1-Bromo-2-trifluoroacetylcyclobutenes as novel building blocks for the construction of trifluoromethyl substituted heterocycles. Part 3: Synthesis of trifluoromethylsubstituted pyridines, condensed with cyclobutene moieties

This paper describes a general synthetic approach to 3-cyano-4-trifluoromethylpyridines fused with cyclobutene rings with variable spiro conjunctions. The reaction of various 1-bromo-2-trifluoroacetylcyclobutenes with ammonia results in the substitution of bromine with an NH₂ group leading to corresponding enaminoketones in high yields, which, in turn, form the target pyridines by treatment with diethyl ethoxymethylencyanophosphonate in the presence of sodium hydride.     

肝衰竭、肝硬化患者的血清微量元素变化

目的观察肝衰竭、肝硬化患者血清微量元素的变化。方法应用微量元素分析仪,检测26例肝衰竭患者、23例肝硬化患者及20例对照者血清中的5种微量元素(Cu、Zn、Ca、Mg、Fe),比较肝衰竭组、肝硬化组与对照组间各微量元素的差异。结果与健康对照组比较,肝衰竭组及肝硬化组的血清锌、钙、镁、铁下降有统计学意义、肝硬化组患者血清铜升高有统计学意义(P0.05)。结论肝衰竭及肝硬化患者存在微量元素紊乱情况。     

Friedel-Crafts Polymers. 8. Friedel-Crafts Polycondensation of β-Resorcylic Acid or Resorcinol with p-Xylylene Dichloride,p,p′-Dichloromethyldiphenyl Ether,and p,p′-Dichloroacetyldiphenyl Ether

Friedel-Crafts polycondensation of β-resorcylic acid (BRA) with p-xylylene dichloride (PXDC) or 4,4′-dichloromethyldiphenyl ether (DDE) in dioxane could be effected without simultaneous decarboxylation of BRA. The similar polycondensation of BRA with PXDC, DDE, or 4,4′-dichloroacetyldiphenyl ether (DADE) in nitrobenzene or in the absence of solvent at 150°C was associated with decarboxylation of BRA. Polymers having structures isomeric with those of the polycondensation product of BRA formed with subsequent in situ decarboxylation were prepared by Friedel-Crafts polycondensation of resorcinol with the above dichlorides. All the polymer samples were characterized, and those with related structures were compared. The ion-exchange properties of the polymer sample prepared from BRA and DDE in dioxane were studied.     

Bioconjugation of Peptides by Palladium-Catalyzed C−C Cross-Coupling in Water

The abiotic, regioselective conjugation of peptides and proteins with non-proteinogenic structural elements requires mild and fast coupling reactions which are compatible with an aqueous reaction medium and orthogonal in their reactivity with all other functional groups in the protein. Sonogashira coupling with a palladium–guanidinophosphane catalyst that is prepared in situ (see reaction on the right) complies with these demands.     

174例男性不育症患者精浆微量元素检测与分析

检测了174例男性不育症患者精浆锌、铁、铅、钙、镁等五种微量元素,以探讨不育症患者精浆微量元素含量与精液质量的关系。结果显示：（1）粘稠性精液组精浆锌含量显著低于正常粘度精液组（P＜0．01）,精浆钙含量低于正常度精液组（P＜0．05）,铁、铅、镁含量无差异（P＜0．05）。（2）无精子及少精子症组精浆铁、钙含量高于精子密度正常组（P＜0．01）,铜含量低于精子密度正常组（P＜0．01）,锌、镁含量无差异（P＜0．05）。（3）精子活动率低下组与正常组浆微量元素含量无差异（P＜0．05）。提示精浆锌、铁、铅、钙等微量元素含量改变是影响精液质量的重要原因之一。精浆镁含量与精液质量似无明显关系。     

BAB‐random‐C Monomer Sequence via Radical Terpolymerization of Limonene (A), Maleimide (B), and Methacrylate (C): Terpene Polymers with Randomly Distributed Periodic Sequences

A naturally abundant terpene, limonene (A), was radically polymerized with a maleimide derivative (B) and methacrylate (C) in a fluorinated alcohol to give terpolymers with unprecedented BAB‐random‐C sequences in which the BAB monomer sequence was randomly copolymerized with a C unit. In each binary system, limonene was hardly copolymerized with methacrylate while it was efficiently copolymerized with maleimide to result in a 1:2‐alternating BAB periodic sequence, in part due to the penultimate effects and hydrogen‐bonding interactions with fluoroalcohol. Methacrylate and maleimide were randomly copolymerized to give copolymers rich in methacrylate units with minimal amounts of maleimide–maleimide sequences. Their terpolymerization resulted in a BAB‐r‐C sequence as a consequence of the selective BAB polymerization between limonene and maleimide, the random copolymerization between methacrylate and maleimide, and the lack of copolymerization between limonene and methacrylate.     

Simple Endotoxin Detection Using Polymyxin-B-Gated Nanoparticles

A nanodevice based on mesoporous silica nanoparticles with rhodamine B in the pore framework, functionalized with carboxylates on the outer surface and capped with the cationic polymyxin B peptide, was used to selectively detect endotoxin in aqueous solutions with a limit of detection in the picomolar range.     

Employment of Electrochemical Techniques for Metallothionein Determination in Tumor Cell Lines and Patients with a Tumor Disease

In the present paper we employed adsorptive transfer stripping technique coupled with chronopotentiometric stripping analysis for determination of metallothionein (MT) in tumor cell lines and differential pulse voltammetry Brdicka reaction for determination of MT in blood serum of patients with head and neck cancer or retinoblastoma, and of rats treated with cisplatin with respect to discuss the role of MT in formation of resistance on treatment with heavy metal based cytostatics. The cisplatin or carboplatin sensitive and resistant neuroblastoma cell lines were derived from the maternal cell line isolated from the bone metastasis of patients with neuroblastoma. Based on the results obtained it can be concluded that level of MT increases with higher dose of platinum based cytostatics at cells. Further we focused on determination of MT in blood serum of rats treated with cisplatin (two doses 1.05 mg and/or 2.1 mg of cisplatin per kg). The highest level of MT at rats treated with 1.05 mg cisplatin was determined after four hours as 4.9 μmol/L. In the case of the second experimental group the maximum was reached even after two hours of the treatment as 4.8 μmol/L. In addition we were interested in the effect of cisplatin or carboplatin treatment of patients with a tumor disease. At patients with tumor in head and neck area treated with cisplatin we observed that the level of MT was going higher due to administration of the drug. This phenomenon was observed at all patients. However at patients with retinoblastoma treated with carboplatin we observed various phenomena including decreasing, increasing or no changes in MT level. Progression of MT levels was therefore individual and probably depended on tumor resistance to carboplatin.     

Electro- and Photoconductivity of Polymer Films Based on 7-Octen-2,4-dionatocobalt

The characteristics of the dark current and photocurrent of samples with sandwich structures with films of macromolecular chelates based on 7-octen-2,4-dionatocobalt. The electro- and photoconductivities increase somewhat with an increase in temperature over the 290-370 K range with small electrical field intensity, but they decrease in large electric fields. A change in the nature of the conductivity from semiconductor to metallic was observed with increase in electric field. It is proposed that the number of cobalt ions, through which electron transfer occurs, changes with changes in the electrical field or the temperature.     

Inhibitory Effect of Anti-HER-2 Anti-CD3 Bi-specific Antibody on the Growth of Gastric Carcinoma

Introduction Gastriccancerisoneofthemostcommonlyen counteredmalignantdiseasesworldwide,especiallyin AsiaandAfrica[1].Thecombinationofoperation,chemotherapyandradiotherapyisusedfortreatinggas triccarcinoma.However,the5yearsurvivalrateof patientsofgastricca…     

卤代苯与水分子间作用的从头算

污染是科学家关注的热点问题,化学污染物是造成水污染的重要因素［１］．在水环境中,卤代苯是一类优先污染物（ｐｒｉｏｒｉｔｙｐｏｌｕｔａｎｔｓ）［２］．这类污染物毒性大,在环境中的半衰期长,美国环保局（ＥＰＡ）已经把它们列入优先污染物之列．Ｖｅｒｓｃｈｎ...     

Induction of Effective Antitumor Immune Response by Combined Administration of hIL-18 and NDV HN

To analyze the antitumor potential and mechanism of action of simultaneous Newcastle disease virus (NDV) hemagglutinin-neuraminidase(HN) and human interleukin 18(hIL-18) gene transfer in C57BL/6 mice with H22 hepatoma,the mouse model with H22 hepatoma was established in C57BL/6 mice, and the antitumor effects of the combined application of NDV HN and hIL-18 were evaluated in vivo. The results show that the growth of established tumors in mice immunized with adenovirus(Ad)-HN in conjunction with Ad-hIL-18 was significantly inhibited compared with that in mice immunized with Ad-HN, Ad-hIL-18 alone, or the empty vector(Ad-mock). Furthermore, the immunization of mice with Ad-HN in conjunction with Ad-hIL-18 elicited strong natural killer activity and H22 tumor-specific cytotoxic T lymphocyte(CTL) responses in vivo. In addition, T cells from the lymph nodes of mice immunized with Ad-hIL-18 or Ad-HN+Ad-hIL-18 secreted high levels of the Th1 cytokine IL-2 and interferon-γ (IFN-γ), indicating that the regression of tumor cells is related to a Th1-type dominant immune response. These results demonstrate that vaccination with NDV HN together with hIL-18 may be a novel and powerful strategy for cancer immunotherapy.     

Oriented attachment mechanism in anisotropic nanocrystals: a "polymerization" approach.

The kinetic model of stepwise polymerization is revisited, with some adaptations for its application to the kinetics of oriented attachment of nanoparticles in colloidal suspensions, which results in the formation of anisotropic particles. A comparison with experimental data reported in the literature shows good agreement with the model and supports comparisons with other systems.