在苯基羧甲基亚砜体系中高氯酸铒对高氯酸铽的荧光增强效应

合成了不同摩尔比的苯基羧甲基亚砜高氯酸铽、铒异核配合物,对配合物进行了组成分析,确定了配合物组成为Tb1-xErxL2ClO4·2H2O(x=0.000～0.200,L=C6H5SOCH2COO-)。通过IR光谱的测定以及摩尔电导推测了配位情况。荧光光谱实验表明:当x=0.001～0.010时铒对铽的荧光均产生敏化增强效应,当x=0.001时敏化强度最大,可使Tb3+荧光强度增加142%。     

An application of rapid freezing,freeze substitution–fixation for scanning electron microscopy

A combined technique of the rapid freezing, freeze substitution–fixation method and the osmium–DMSO-osmium method was devised. By this combined method we clearly observed the architecture of intracellular components in three dimensions. Morphological characteristics were generally similar to those of tissue prepared by the osmium–DMSO-osmium method but different in some respects. Mucigen droplets in intestinal goblet cells, for example, appeared as separated spheres, while in specimens prepared by chemical fixation they were observed as a mass of fused droplets. In the Golgi complex, all cisternae were extremely flat, although they usually dilated on the cis side after chemical fixation. Particles on the mitochondrial tubules of liver cells were well distinguished. They were mushroom shaped, as are those observed by negative staining. The combined method, that is, the rapid freezing, osmium–DMSO-osmium method, is thought to be effective for studying the true structure of intracellular components by scanning electron microscopy.     

亚砜基改性纤维素膜的SO2气体渗透性能研究

分别使用二甲基亚砜浸泡的物理方法及苯基乙烯基亚砜加成的化学方法对纤维素膜进行了改性,并对改性膜的性能进行了测试.结果表明改性后纤维素膜仍为致密结构,SO2的渗透性能及其对N2的分离性能明显提高,其中改性液中添加二甲基亚砜的均相化学加成反应所得的改性膜具有较好的SO2渗透稳定性.     

Preparation,characterization, and adsorption properties for metal ions of a novel chelating resin containing sulfoxide and diethylene glycol

A novel chelating resin containing sulfoxide and diethylene glycol, poly{4‐vinylbenzyl‐[2‐2‐(hydroxyethyl)ethoxyl]sulfoxide} (PVESO) was synthesized using chloromethylated polystyrene (PS‐Cl) as material. Its structure was characterized by elemental analysis, infrared spectra, and scanning electron microscopy (SEM). The adsorption capacities of the resin for Hg²⁺, Ag⁺, Cu²⁺, Zn²⁺, and Pb²⁺ at various pH values were determined. The maximum adsorption capacities for Hg²⁺ and Ag⁺ were 1.56 and 0.75 mmol g^?1 respectively. The resin had high selectivity for Hg²⁺ and Ag⁺ over the pH range 1.0–7.0. The adsorption capacities for Hg²⁺ and Ag⁺ under competitive condition were also determined by batch experiment method. In addition, the adsorption kinetics of the resin towards Hg²⁺ at different temperatures was also investigated. The results showed that the adsorption rate was governed by film diffusion at 20°C and 25°C, by particle diffusion at 30°C and 35°C. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 6054–6059, 2006     

石油亚砜树脂分离稀土的性能研究

应用石油亚砜萃取树脂与ＮＨ＿４ＣＮＳ体系，测定了稀土元素的分配比（Ｋｄ）、分离因素（β）和分离度Ｒｓ），讨论了ＮＨ＿４ＣＮＳ的浓度、稀土进样量和温度等对稀土分离的影响。应用于混合稀土的分离和测定，分析了６０．３２％的氧化钇，相对标准偏差为±１．４７％。     

Synthesis of poly(vinyl propionate) from poly(vinyl alcohol) in nonaqueous medium using ethyl nitrate dimethyl sulfoxide as a catalyst

Poly(vinyl alcohol) (PVA) can be dissolved in a nonaqueous medium in the presence of catalytic concentration of ethyl nitrate dimethyl sulfoxide, C₂H₅ONO₂·DMSO. From the PVA solution, poly(vinyl propionate), PVPR was prepared by the homogeneous esterification of PVA with propionic acid. The ester thus formed contained some unconverted hydroxyl group. The formation of the ester was confirmed by the IR and ¹H‐NMR spectra. The molecular weight of the ester was determined by GPC and intrinsic viscosity (η) was determined by viscometric method. Glass transition temperature, T_g, was obtained from differential scanning calorimetric (DSC) analysis. Thermal stabilities of the ester were checked by thermogravimetric analysis (TGA) and differential thermogravimetric (DTG) analysis. The efficiency of the ester as a flow improver of crude oil was also examined. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5675–5679, 2006     

盐酸介质中异戊基苯并噻唑亚砜萃取Pd(Ⅱ)的机理

合成了异戊基苯并噻唑亚砜(ABSO),研究了盐酸介质中ABSO萃取Pd(Ⅱ)的机理。考察水相H 浓度和萃取剂浓度对钯萃取的影响,采用斜率法、红外光谱和核磁共振H谱法确定了萃合物的组成及萃取平衡的机理。结果表明:低酸度条件下,H 浓度对钯的分配比无影响,ABSO以中性配位萃取机理萃取Pd(Ⅱ),并通过苯并噻唑环上的氮原子与Pd(Ⅱ)配位形成萃合物PdCl2(ABSO)2。     

Drug self-assembly: A phenomenon at the nanometer scale with major impact in the structure–biological properties relationship and the treatment of disease

Under water-rich conditions, small amphiphilic and hydrophobic drug molecules self-assemble into supramolecular nanostructures. Thus, substantial modifications in their interaction with cellular structures and the ability to reach intracellular targets could happen. Additionally, drug aggregates could be more toxic than the non-aggregated counterparts, or vice versa. Moreover, since self-aggregation reduces the number of effective “monomeric” molecules that interact with the target, the drug potency could be underestimated. In other cases, the activity could be ascribed to the non-aggregated molecule while it stems from its aggregates. Thus, drug self-assembly could mislead from drug throughput screening assays to advanced preclinical and clinical trials. Finally, aggregates could serve as crystallization nuclei. The impact that this phenomenon has on the biological performance of active compounds, the inconsistent and often controversial nature of the published data and the need for recommendations/guidelines as preamble of more harmonized research protocols to characterize drug self-aggregation were main motivations for this review. First, the key molecular and environmental parameters governing drug self-aggregation, the main drug families for which this phenomenon and the methods used for its characterization are described. Then, promising nanotechnology platforms investigated to prevent/control it towards a more efficient drug development process are briefly discussed.     

Effect of the solvent on the conformational behavior of the alanine dipeptide deduced from MD simulations

In general, peptides do not exhibit a well-defined conformational profile in solution. However, despite the experimental blurred picture associated with their structure, compelling spectroscopic evidence shows that peptides exhibit local order. The conformational profile of a peptide is the result of a balance between intramolecular interactions between different atoms of the molecule and intermolecular interactions between atoms of the molecule and the solvent. Accordingly, the conformational profile of a peptide will change upon the properties of the solvent it is soaked. To get insight into the balance between intra- and intermolecular interactions on the conformational preferences of the peptide backbone we have studied the conformational profile of the alanine dipeptide in diverse solvents using molecular dynamics as sampling technique. Solvents studied include chloroform, methanol, dimethyl sulfoxide, water and N-methylacetamide. Different treatments of the solvent have been studied in the present work including explicit solvent molecules, a generalized Born model and using the bulk dielectric constant of the solvent. The diverse calculations identify four major conformations with different populations in the diverse solvents: the C₇^eq only sampled in chloroform; the C₅ or extended conformation; the polyproline (PII) conformation and the right-handed α-helix conformation (α_R). The results of present calculations permit to analyze how the balance between intra- and intermolecular interactions explains the populations of the diverse conformations observed.     

低浓度SO_2在二甲基亚砜中溶解度热力学模型

选用二甲基亚砜作为一种新的脱硫吸收剂 ,用静态法在常压吸收装置中 ,实验测定了低浓度SO2 在二甲基亚砜中的溶解度。实验温度 2 93.15— 313.15K ,SO2 分压 0 .15— 3kPa ,根据测得的气液平衡数据 ,建立了溶解度模型。通过单纯形寻优法求得NRTL二元交互作用参数 ,据此模型算出的溶解度与实验值符合良好