Influence of the microbiota on epigenetics in colorectal cancer

Colorectal cancer is one of the most common malignancies and is the second leading cause of cancer death worldwide. Generally, there are three categories of colorectal cancer development mechanism—genetic, epigenetic and aberrant immunological signaling pathways—all of which may be initiated by an imbalanced gut microbiota. Epigenetic modifications enable host cells to change gene expression without modifying the gene sequence. The microbiota can interact with the host genome dynamically through the interface presented by epigenetic modifications. In particular, bacterially derived short-chain fatty acids have been identified as one clear link in the interaction of the microbiota with host epigenetic pathways. This review discusses recent findings relating to the cross talk between the microbiota and epigenetic modifications in colorectal cancer.     

一种应用聚类分析的科研立项评审数据处理方法

本首先简单地介绍了基金项目立项评审的操作过程和现行专家评审数据的处理方法,并举例分析了这种处理方法所存在的不足,最后,从聚类分析的角度出发,提出了两种新的数据处理方法,表格聚类法和指标聚类法,分析表明,在立项评审中采用这两种数据处理方法比现行的处理方法更具有可行性。     

生物大分子溶液结构的NMR测定法

随着高分辨核磁共振（ＮＭＲ）仪和多维ＮＭＲ技术的快速发展,近年来高场ＮＭＲ仪已成为测定生物大分子在溶液中的三维结构的最强有力的手段。目前已有１７００多个生物大分子的溶液结构用高分辨ＮＭＲ技术进行了测定。该文简要综述了这一高新技术的特点、测定流程,并分析了若干实例。     

运动结合饮食干预对肥胖青少年血清脂肪酸组分和身体成分的影响及其相关性研究

目的：探索4周运动结合饮食干预对肥胖青少年的血清脂肪酸组分和身体成分的影响,同时分析脂肪酸基础值与身体成分相关指标变化量的相关性。方法：以2017年暑期参加皓千体育发展有限公司全封闭减肥训练营的25名肥胖青少年为研究对象（平均年龄：15.96±1.88y;平均BMI：32.66±4.51 kg/m²）,进行为期4周的联合运动结合饮食干预,干预前后测试并分析身体成分、身体形态和血清脂肪酸组分的变化及其相互关系。结果：4周后,受试者的体重、身体质量指数（BMI）、体脂量、脂肪质量指数（FMI）、四肢脂肪量、腰围、臀围和腰臀比均显著降低,瘦体重%显著增加（P<0.001）;血清饱和脂肪酸（SFA）中,总饱和脂肪酸（SFAs）、肉豆蔻酸（C14：0）、十五烷酸（C15：0）、棕榈酸硬（C16：0）、脂酸（C18：0）、花生酸（C20：0）、山萮酸（C22：0）、二十三烷酸（C23：0）和二十四烷酸（C24：0）含量均显著降低（P<0.05）;单不饱和脂肪酸（MUFA）中,总单不饱和脂肪酸（MUFAs）、棕榈油酸（C16：1 n-7）、油酸（C18：1 n-9）和鳕油酸（C20：1 n-9）含量显著降低（P<0.01）;多不饱和脂肪酸（PUFA）中,总多不饱和脂肪酸（PUFAs）、总n-6多不饱和脂肪酸（n-6 PUFA）、亚油酸（C18：2 n-6）、二十碳二烯酸（C20：2 n-6）、双高-γ-亚麻酸（C20：3 n-6,DGLA）、花生四烯酸（C20：4 n-6,ARA）和α-亚麻酸（C18：3 n-3）显著下降（P<0.05）;Pearson相关性分析及一元线性回归分析表明,干预前血清C14：0与C20：3 n-6的基础值与体脂%及瘦体重%的变化量正相关,C16：1 n-7的基础值与体脂量、上肢脂肪量、右下肢脂肪量的变化量正相关（P<0.05）。结论：4周运动和饮食干预能明显改善肥胖患者身体成分、身体形态及血清脂肪酸组分;血清C14：0、C16：1 n-7、C20：3 n-6的基础值与身体成分的变化量存在线性关系,可以为减肥夏令营的饮食优化及减肥效果的预测提供参考。     

HPLC method for amino acids profile in biological fluids and inborn metabolic disorders of aminoacidopathies

Quantification of total and individual amino acids in biological fluids such as plasma, urine and cerebrospinal fluid has an important diagnostic implication in laboratory medicine. The present paper describes protocols for the assay of total amino acids by modified method based on dinitrophenyl and HPLC profile involving pre-column derivatization with o-pthalaldehyde (OPA) derivatization, respectively. The method, based on the alkylation of-SH groups prior to OPA derivatization of amino acids followed by reverse phase high performance liquid chromatography, provide a comprehensive profile of more than twenty amino acids (including-SH group containing) in a single run lasting about 45 minutes. The present study, apart from establishing the normal profile of amino acids in plasma of Indian sub population, also presents HPLC profile for some of the rare amino acidopathies.     

户外拓展体力活动特征与支链氨基酸关系模型研究

目的:探讨户外拓展体力活动特征与支链氨基酸代谢关系模型。方法:以一次20人为时4天的户外拓展训练为对象,分为男子组和女子组,通过每天对于不同受试对象的脉搏指数,血压指数,疲劳指数,肺活量指数等影响支链氨基酸代谢过程和代谢程度的量进行监测,构建户外拓展体力活动的过程与支链氨基酸详细代谢关系模型。结果:随着天数增加,男子组脉搏指数明显高于女子组,且稳定性较女子组差,男子组与女子组的血压指数基本相当,男子组疲劳指数高于女子组,肺活量指数高于女子组。结论:通过采用该方法构建的户外拓展体力活动特征与支链氨基酸代谢关系模型,在不同时间内,支链氨基酸的代谢稳定,对于机体持续代谢氧气需求量的稳定性更高,肺活量指数影响支链氨基酸代谢对于男性而言更加明显。分析证明该模型能有效改善脉搏指数,血压指数,疲劳指数,肺活量指数对支链氨基酸代谢过程和代谢程度的影响,为定量分析氨基酸在人体内代谢功能提供数据基础,分析户外拓展体力活动特征与人体正常代谢和生命运作的关系提供理论模型。     

Synthesis of TiO_2 supported on activated carbon by MOCVD:operation parameters study

A novel metallo-organic chemical vapor deposition (MOCVD) technique has been applied to the preparation of the photocatalytic titanium dioxide supported on activated carbon. The effects of various condition parameters such as carrier gas flow rate, source temperature and deposition temperature on the deposition rate were investigated. The maximum deposition rate of 8.2 mg/(g·h) was obtained under conditions of carrier gas flow rate of 400 ml/min, source temperature of 423 K and deposition temperature of 913 K. The deposition rate followed Arrhenius behavior at temperature of 753 K to 913 K, corresponding to activation energy Ea of 51.09 kJ/mol. TiO2 existed only in anatase phase when the deposition temperature was 773 K to 973 K. With increase of deposition temperature from 1073 K to 1273 K, the rutile content sharply increased from 7% to 70%. It was found that a deposition temperature of 773 K and a higher source temperature of 448 K resulted in finely dispersed TiO2 particles, which were mainly in the     

The response of intracellular signaling and muscle-protein metabolism to nutrition and exercise

Abstract

In recent years, a body of literature examining the response of muscle-protein metabolism to exercise and nutrition has arisen. Developments in methods, especially stable isotopic tracer methodology, have allowed much information to be gathered in vivo in humans. The metabolic mechanism behind increased muscle mass requires that muscle-protein synthesis exceeds breakdown, i.e., net muscle-protein synthesis. Increased net muscle-protein balance may occur due to exercise, but net synthesis may occur only with the addition of nutrients, particularly a source of amino acids. The major impact of increased amino acid availability on net muscle-protein balance is due to stimulation of muscle-protein synthesis and less to inhibition of muscle-protein breakdown. Amino acids seem to stimulate muscle-protein synthesis, not only by mass action, i.e., providing substrate, but also as signals for initiation of protein synthesis. Stimulation of muscle-protein synthesis by amino acid ingestion may be linked to increased intracellular amino acid levels and/or to changing amino acid levels in the blood. Carbohydrate ingestion, most likely through the action of insulin, also may play a role in the response of muscle to exercise and nutrition. There is very little research in humans in vivo on the intracellular signaling that is linked to muscle-protein synthesis. It is clear that intracellular signaling responds to both insulin and amino acids, but the interactions with exercise are not well known; however, the details of the pathways have only just begun to be investigated, especially in humans. Delineation of these pathways is complicated, and there is little doubt that multiple intracellular signaling pathways with several levels of communication are involved in the hypertrophy process in response to nutrition and exercise. A systematic investigation of the relationship of the signaling to insulin and amino acids combined with exercise will provide important information, especially for populations vulnerable to muscle loss.     

氨基酸清除活性氧自由基作用的研究

分别采用Ｘ－ＸＯＤ－Ｌｕｍｉｎｏｌ的Ｏ２＾－产生模型和Ｖｃ－Ｃｕ＾２＋－Ｈ２Ｏ２－酵母多糖的ＯＨ产生体系，以还原型谷胱甙肽（ＧＳＨ）作为参照，用化学发光法研究了１９在酸对活性氧自由基的清除能力，证实了氨基酸普遍具有生物抗氧化活性，其抗Ｏ２＾－的有效浓度范围在１０＾－２￣１０＾－４ｍｏｌ／Ｌ，比ＧＳＨ高出二个数量级。     

生物样品中短链脂肪酸提取测定及其应用进展

综述了不同样品（尿液、血液、生物培养液等）中短链脂肪酸的测定方法,讨论了气相色谱、高效液相色谱、毛细管电泳、原子吸收分光光度测定方法的优缺点,并讨论了短链脂肪酸在营养生理、疾病以及肠道菌群中的应用研究进展.