Molecular dynamics simulation of the interactions between EHD1 EH domain and multiple peptides

Objective: To provide essential information for peptide inhibitor design, the interactions of Eps15 homology domain of Eps15 homology domain-containing protein 1 (EHD1 EH domain) with three peptides containing NPF (asparagine-proline-phenylalanine), DPF (aspartic acid-proline-phenylalanine), and GPF (glycine-proline-phenylalanine) motifs were deciphered at the atomic level. The binding affinities and the underlying structure basis were investigated. Methods: Molecular dynamics (MD) simulations were performed on EHD1 EH domain/peptide complexes for 60 ns using the GROMACS package. The binding free energies were calculated and decomposed by molecular mechanics/generalized Born surface area (MM/GBSA) method using the AMBER package. The alanine scanning was performed to evaluate the binding hot spot residues using FoldX software. Results: The different binding affinities for the three peptides were affected dominantly by van der Waals interactions. Intermolecular hydrogen bonds provide the structural basis of contributions of van der Waals interactions of the flanking residues to the binding. Conclusions: van der Waals interactions should be the main consideration when we design peptide inhibitors of EHD1 EH domain with high affinities. The ability to form intermolecular hydrogen bonds with protein residues can be used as the factor for choosing the flanking residues.     

Role of water molecules in sodium bis(2-ethylhexyl) phosphate reversed micelles in n-heptane

Recently molecular modeling was employed on the metal-extracted aggregates that form during the liquid/liquid extraction of transition metals. During the extraction process, the aqueous phase pH is adjusted with sodium hydroxide. In additional to the formation of the transition metal-extractant reversed micelles, sodium-bis(2-ethylhexyl) phosphate (NaDEHP) reversed micelles can also form. According to the classical model of reversed micelles, water molecules act as promoters for the formation of reversed micelles. Water molecules act as “gluing” agents for micellization in apolar media. Here we report a unique finding about the role of water molecules in reversed micellar aggregates using molecular modeling. The molecular modeling of the reversed micellar system of NaDEHP in n-heptane clearly shows that water molecules can act as an “antimicellization” agent. Water molecules have no gluing effect on the formation of NaDEHP reversed micelles. In fact, large NaDEHP reversed micelles are formed in “dry” conditions.     

江苏省男子羽毛球运动员夏训期间身体机能的生化评定

本文运用多个生化指标对夏训期间江苏省男子羽毛球运动员的身体机能进行了跟踪观察和综合评定。结果表明，训练周期开始尿蛋白、血尿素氮明显升高、后逐渐下降；血红蛋白呈现开始降低后期回升的趋势；而唾液睾酮、皮质醇则处于持续升高水平。提示：运动员对大运动量训练经历了一个从不适应到适应的过程，整个周期中身体机能呈平稳上升趋势。     

红豆杉科及三尖杉科的分子系统发育——兼论竹柏属的系统位置

测定了红豆杉科、三尖杉科、罗汉松科及松科共9属13种植物的matK基因序列,发现3′端的单碱基插入造成mat k基因在这些类群间有较大的长度变异(1488∽1548bp),其它插入或缺失的长度为3、6或9bp(白豆杉中有一个长为27bp的缺失),且绝大多数插入或缺失事件具有系统发育信息。matK基因中,密码子第1、2及3位的变异率较为相近,平均同义替代率约为平均非同义替代率的2倍。以松科2属3种植物为外类群,运用PAUP软件进行的系统发育分析仅得到一棵最简约树(步长为895,CI=0．850,RI=0．876),该简约树的各分支均得到bootstrap分析的极强支持。结果表明：红豆杉科与三尖杉科均为单系群,二者互为姐妹群;白豆杉属与穗花杉属为红豆杉科中两个很自然的属,白豆杉属为红豆杉属的姐妹群,穗花杉属为榧树属的姐妹群。竹柏属与罗汉松属聚为一支,二者间的亲缘关系得到boot-strap分析的100％支持,从分支分类学及遗传距离角度,作者不赞同将竹柏属提升为科。     

基于分子信标的DNA自组装模型研究

分子信标操作简单且不必与未反应的探针分离即可进行实时检测,将分子信标与自组装结合,将为DNA计算研究提供新的思路及方法.本文介绍了基于分子信标的DNA自组装模型的算法思想,阐明了分子信标设计要点,描述了生物实现步骤,并对如何提高分子信标的检测准确性做了展望.     

粗粒化DNA穿孔行为的分子动力学模拟

核酸穿过核膜或细胞膜等穿孔行为,是重要的生命活动之一.为进一步了解核酸穿孔过程,建立DNA粗粒化模型,运用分子动力学方法模拟DNA穿孔行为.结果表明,孔长越长,孔内拉力越大,DNA链在孔外等待的时间越短,穿过孔所需的时间越短;但其中各因素的单独影响作用都比较有限;孔右侧力场对穿孔时间影响显著,一定条件下对穿孔过程起决定性作用.     

Role of Common Biochemical Markers for the Assessment of Fracture Union

The progress of fracture union requires close monitoring. Whereas, clinical examination and radiographic studies assess the outcome, biochemical markers like serum alkaline phosphatase and urinary hydroxyproline reflect the actual status of bone resorption and bone formation over a short time frame. 36 patients of long bone fracture were randomly allocated for the study. When the patient reported to the Department of Orthopedics after fracture, serum and urinary samples were collected and X-ray of the affected part were taken. Subsequent samples were collected and X-ray taken just after management (either operative or conservative), after 3rd, 5th, 8th and 12th week, respectively after onset of fracture. According to the course of callus formation the patients were divided into two groups that progressed to proper union or malunion. The levels of serum alkaline phosphatase, urinary total and free hydroxyproline levels were measured and statistically analysed and compared. A statistically significant positive correlation between total urinary hydroxyproline excretion and serum alkaline phosphatase indicate progress towards satisfactory union. Thus, serial monitoring of biochemical markers of bone turnover can be used as an adjunct to clinical and radiological evidence of fracture healing.     

Roles and molecular mechanisms of physical exercise in cancer prevention and treatment

Exercise can enhance motivation to change lifestyle behaviors, improve aerobic fitness, improve physical function, control fatigue, and enhance quality of life. Studies have demonstrated the benefits to be gained from physical exercise, highlighting the importance of popularizing the concept of physical exercise for individuals and making professional exercise-treatment programs available to patients with cancer. However, the correlation between physical exercise and carcinogenesis is easily overlooked, and exercise interventions are not routinely provided to patients with cancer, especially those with advanced cancer. In this article, we present a literature review of the effects of exercise on cancer development and progression and give recent evidence for the type of exercise best suited for different types of cancer and in different disease stages. Moreover, the molecular mechanisms about regulating metabolism and systemic immune function in cancer are summarized and discussed. In conclusion, physical exercise should be considered as an important intervention for preventing and treating cancer and its complications.     

铝磷酸盐分子筛材料的研究进展

综述了铝磷酸盐分子筛在尺度上由微孔、大孔直到介孔的发展历程,在制备方法上从最初的水热合成到溶剂热合成及有机/无机复合改性的发展变化;并介绍了磷酸盐分子筛的研究现状.