微量量热法筛选抑菌特效药的研究

用微量最热计连续测定细菌代谢过程中的热显变化，可获得反映细菌代谢规律的完整的热谱图以按指数生长模型对指数生长期进行处理，可计算出细菌正常代谢的生长速率常数L’．若在培养基中加入合成药物，使细菌在药物抑制作用下生长，也可获得完整的热谱图，从而计算出在药物抑制作用下细菌的生长速率常数．本义对福氏志贺氏Zb菌和金黄色葡萄球莉在四种合成药物抑制作用下的热谱进行了测定，并计算了生长速率常数，找出了细菌生长速率常数与所用药物浓度之间的定量关系，可为筛选抑菌药物和确定用药显提供定量依据’1基本原理设细菌在代谢过…     

Schiff碱药物对产气杆菌代谢抑制的热力学研究

用微量热法测定产气杆菌在不同温度条件下受到Schiff碱药物抑制的热谱曲线, 根据其指数生长期的热谱信息, 确定它在不同温度条件下的生长速率常数和反应活化能, 找出了该细菌的最佳生长温度。同时借用化学反应中的过渡态理论, 得到一系列热力学参数, 对细菌在受到抑制时的生长代谢进行了热力学分析。     

Schiff碱药物与细菌作用的半抑制量比较研究

用微量热法测定了金黄色葡萄球菌和产气杆菌分别与十一种Ｓｃｈｉｆｆ碱药物作用的热谱曲线根据热谱曲线计算了细菌生长的速率常数Ｋ，建立了Ｋ～Ｃ关系式，进行在获得的Ｓｃｈｉｆｆ碱药物对细菌作用的半抑制量Ｃ１／２的基础上，通过对半抑制量大小的比较，分别对配体相同金属离不同，金属离子相同配体不同的Ｓｃｈｉｆｆ碱药物与细菌的作用以及对同一药物与不同细菌作用的情况做了较深入的讨论，发现，同一药物对不同的菌种其药效     

人参对金黄色葡萄球菌的代谢过程促进作用的研究

前文[1]已报导了合成药物对细菌抑制作用的研究．药物抑菌生长的热化学研究是当今热化学法研究的一个活跃领域，Boling[2]、Nordmark[3]等人已做了很有意义的工作．在此基础上，作者对畜养药物促进细菌代谢过程进行了研究，用微量量热仪测定了人参对金黄色葡萄球菌代谢过程起促     

硒的热化学研究──Ⅳ.微量热法研究Na_2SeO_3对微生物生长代谢的抑制

用微量热法研究了对大肠杆菌、产气杆菌、枯草杆菌、黑根霉菌4种菌作用的产热曲线，计算了微生物的生长速率常数k，比较了Na2SeO3对4种微生物作用的半抑制浓度IC50，发现Na2SeO3浓度低于10mg／L时，对微生物生长有促进作用，高于此浓度时有抑制作用，对不同微生物生长代谢的抑制情况不同，反映了微生物之间的差异和硒对细胞作用热动力学特征的不同．     

微量热法测定细菌的临界生长温度

应用微量热学的方法,我们已能成功地测得细菌生长过程的热谱,这种热谱包含着有关细菌生长代谢过程的丰富信息,例如对热谱曲线的指数生长段进行解析,可得出细菌生长的速率常数、激活能和有关的热力学参数。故采用微量热法测定细菌在不同培养温度下的生长速率常数,利用计算机拟合出相应k(速率常数)和T(培养温度)的线性关系式后,若把生长速率为零的温度定义为临界生长温度时,就可以根据由上述实验所得的k～T线性关系式求得细菌的临界生长温度。本工作仍采用微量热法对福氏志贺氏菌(S. flexneri)和大肠埃希氏菌(E. coli)进行实验测定。按文献的方法求出它们在不同温度下的生长速率常数;对于大肠埃希氏菌还用几种不同的培养基分别进行实验测定。     

微量热法表征邻香草醛氨基葡萄糖Schiff碱锌配合物的抗菌活性

用微量热法测定了大肠杆菌（细菌）及其在Ｚｎ－ｏ－ＶＧ（ｏ－ＶＧ：邻香草醛氨基葡萄糖Ｓｃｈｉｆｆ碱）作用下不同温度下的热谱；计算了它的生长速率常数ｋ、传找时间Ｇ、抑制率Ｉ、总产热量Ｑ、单个细菌的平均产热Ｑ０的单位时间平均每个细菌的产热量＾－量Ｑ０；建立了细菌生长代谢各种参量之间的函数关系，探讨了在不同温度和药物作用下细菌的生长代谢；发现可用ｔｇ、ｔｒ和ｔ表征细菌的生长代谢和药物的抗菌活性。     

环境气氛对微量热安瓿法测定细菌生长速率常数的干扰

采用微量热安瓿法测定细菌生长时,发现细菌的代谢产热曲线在第一指数生长期内出现了停留法没有报导过的显著分阶段现象,且在不同的阶段生长速率常数有很大差异,对药物抗菌性能的评估造成极大干扰.为了寻找此现象的可能原因,以具有代表性的兼性细菌大肠杆菌为例,设计了微量热安瓿法实验,考察了不同环境气氛下大肠杆菌的生长代谢产热;并模拟了停留法条件下细菌的生长环境,通过安瓿法测定了大肠杆菌的生长代谢产热,重新解析了这些条件下细菌的生长速率常数.结果表明环境气氛是造成此现象的主要可能因素,并为在不同环境气氛下采用微量热安瓿法准确评估细菌的生长速率提供了一个可参考的标准.     

硒的热化学研究：IV.微量热法研究Na2SeO3对微生物生长代谢的抑制

用微量热法研究了对大肠杆菌、产气杆菌、枯草杆菌、黑根霉菌４种菌作用的产热曲线，计算了微生物的生长速率常数ｋ，比较了Ｎａ２ＳｅＯ３对４种微生物作用的半抑制浓度ＩＣ５０，发现Ｎａ２ＳｅＯ３浓度低于１０ｍｇ／Ｌ时，对微生物生长有促进作用，高于此浓度时有抑制作用，对不同微生物生长代谢的抑制情况不同，反映了微生物之间的差异和硒对细胞作用热动力学特征的不同。     

Schiff碱金属配合物在细菌代谢过程中的表征

采用微量热法测定了产气杆菌在四种Schiff碱金属配合物作用下的代谢热谱, 以其对数生长期的生长速率常数k表征了Schiff碱金属配合物对其细菌生长的抑制。不同的配合物其抑制情况不同。Co(II)-NG(NG : D-氨基葡萄糖-β-萘酚醛Schiff碱)对产气杆菌的抑制作用最大, 随着浓度c的增加抑制作用增大, 在350μg.mL^-^1时可完全抑制其生长, 但k-c并不呈线性关系; Fe(II)-NG对产气杆菌的抑制较小, 且在50-300μg.mL^-^1浓度范围内k与浓度无关, 在350μg.mL^-^1时才略表现有一定的抑制作用; Cu(II)-NG和Zn(II)-NG对产气杆菌的抑制作用也较小, 且k随着浓度的变化不规则, 同时发现热谱上最大热输出功率Pmax与生长速率常数存在正比关系, 进而推出在实验条件相同的情况下可用Pmax代替k。     

Thermo-kinetic Investigation of Optimum Growth Temperature of Petroleum Bacteria

The power-time curves of the growth of three strains of petroleum bacteria at different temperatures have been determined. A novel equation of a power-time curve has been proposed in this paper. The general formula to calculate the rate constant of the bacterial growth has been derived. The rate constants of the bacterial growth at different temperatures, the heat production per newly formed bacterium, the bacterial number at the end of the bacterial growth and the deceleration rate constant of the bacterial growth at 50.00°C, have been calculated. The optimum growth temperatures of the three strains have been obtained.This revised version was published online in November 2005 with corrections to the Cover Date.     

The Growth of KLN Crystals

１ＩＮＴＲＯＤＵＣＴＩＯＮＣｒｙｓｔａｌｏｆＫ３Ｌｉ２＋ｘＮｂ５＋ｘＯ１５＋２ｘｉｓａｆｅｒｏｅｌｅｃｔｒｉｃｃｒｙｓｔａｌｂｅｌｏｎｇｉｎｇｔｏｔｅｔｒａｇｏｎａｌｓｙｓｔｅｍｗｉｔｈｔｈｅｓｔｒｕｃｔｕｒｅｏｆｔｈｅｍｉｎｅｒａｌｔｕｎｇｓｔｅｎ...     

偶氮芳基水杨醛缩氨基硫脲衍生物的合成及其生物活性研究

在室温下, 以酸作催化剂, 通过简单的方法合成了9个未见文献报道的偶氮芳基水杨醛缩氨基硫脲类化合物, 并通过元素分析、红外光谱及核磁共振谱确证了其结构. 初步的生长调节活性实验结果表明, 该类化合物在不同的浓度下对植物的生长调节表现出一定的规律性.     

Self-catalysis: a contamination-free, substrate-free growth mechanism for single-crystal nanowire and nanotube growth by chemical vapor deposition

A unified mechanism for the growth of a wide variety of long, uniform, single-crystal nanowires and whiskers, including III-V and II-VI binary, ternary, and quaternary nanowires and whiskers, without the use of any substrate and catalyst has been presented. While elucidating the mechanism, attempts have been made to provide a kinetic and thermodynamic rationale for the growth. Various features of the growth mechanism, including the formation of liquid droplets and seeds, nucleation, and creation of products, have been discussed. Extensive studies of illustrative examples provide the validity of the proposed mechanism. The influence of various parameters such as growth temperature and chamber pressure on the growth mechanism has been studied. The advantages and disadvantages of the proposed mechanism, and its superiority to the well-known vapor-liquid-solid mechanism, have been elucidated. Means to improve the mechanism to obtain self-aligned nanowires and whiskers have been suggested. Based on these, it has been demonstrated that the present mechanism is indeed a powerful self-catalytic growth mechanism uniquely suited to the growth of a wide variety of single-crystal nanowires and whiskers. It can be very useful also for the growth of single-crystal nanotubes.     

Process study of thermal plasma chemical vapor deposition of diamond,part II: Pressure dependence and effect of substrate pretreatment

The effect of pressure during thermal plasma chemical vapor deposition of diamond films has been investigated for a pressure range from 100 to 760 Torr. The maximum growth rate in our experiments occurs at 270 Torr for substrate temperatures around 1000°C. The existence of an optimum pressure for diamond deposition may he related to the balance between generation and recombination of atomic hydrogen and carbon-containing active species in front of the substrate. To estimate the concentrations of atomic hydrogen and methyl radicals under thermal plasma conditions, calculations based on thermodynamic equilibrium have been performed. This approximate evaluation provides useful guidelines because rapid diffusion results in a near frozen chemistry within the boundary layer. The effect of substrate pretreatment on diamond deposition depends on the type of substrate used. Two growth modes have been observed-layer growth and island growth of diamond crystals on various substrates. Screw dislocations have been observed in diamond deposition in thermal plasmas, and defects such as secondary nucleations are more concentrated along (III) directions than along (100) directions.     

Synthesis of monodisperse spherical nanocrystals

Much progress has been made over the past ten years on the synthesis of monodisperse spherical nanocrystals. Mechanistic studies have shown that monodisperse nanocrystals are produced when the burst of nucleation that enables separation of the nucleation and growth processes is combined with the subsequent diffusion-controlled growth process through which the crystal size is determined. Several chemical methods have been used to synthesize uniform nanocrystals of metals, metal oxides, and metal chalcogenides. Monodisperse nanocrystals of CdSe, Co, and other materials have been generated in surfactant solution by nucleation induced at high temperature, and subsequent aging and size selection. Monodisperse nanocrystals of many metals and metal oxides, including magnetic ferrites, have been synthesized directly by thermal decomposition of metal-surfactant complexes prepared from the metal precursors and surfactants. Nonhydrolytic sol-gel reactions have been used to synthesize various transition-metal-oxide nanocrystals. Monodisperse gold nanocrystals have been obtained from polydisperse samples by digestive-ripening processes. Uniform-sized nanocrystals of gold, silver, platinum, and palladium have been synthesized by polyol processes in which metal salts are reduced by alcohols in the presence of appropriate surfactants.     

Growth of large-area aligned molybdenum nanowires by high temperature chemical vapor deposition: synthesis, growth mechanism, and device application

Large-area aligned Mo nanowires have been grown on stainless steel substrates by high-temperature chemical vapor deposition with the use of Mo metal. The detailed physical and chemical growth processes regarding the formation of the nanowires have been investigated using mass spectroscopy, thermogravimetry, and differential scanning calorimetry analysis, as well as structure analysis by electron microscopy. In reference to Gibbs energy calculation, our study reveals that the growth relies on the decomposition of MoO2 vapors through condensation of its vapor at high substrate temperatures. The aligned growth is a result of competing growth with the nanowires normal to the substrate surface reaching the final growth front. The field emission measurement and the vacuum luminescent tube study show that the Mo nanowires have potential application as electron emitters.     

Covalent growth factor immobilization strategies for tissue repair and regeneration

Growth factors play a critical role in regulating processes involved in cellular differentiation and tissue regeneration, and are therefore considered essential elements in many tissue engineering strategies. The covalent immobilization of growth factors to biomaterial matrices addresses many of the challenges associated with delivering freely-diffusible growth factors and has thus emerged as a promising method of achieving localized and sustained growth factor delivery. This Feature Article discusses methods that have been used to immobilize growth factors to substrates, followed by an overview of several tissue repair and regeneration applications in which immobilized growth factors have been used.     

Investigation of the Crystallization Kinetics of Zn(Met)(AcO)_2·H_2O in Mixed Solution of Water and Acetone by Microcalorimetry

Introduction The complexes of zinc salts with -amino acid as additive have a wide application in medicine, foodstuff and cosmetics.1-3 The synthesis methods of the com-plexes of zinc salts with -amino acid have been re-viewed.4 The solubility of Zn(AcO)2-Met-H2O system at 298.15 K has ever been investigated by the semi-micro-phase equilibrium method.5 The phase diagram is a simple one, in which the solid complex of Zn(AcO)2 and Met can not be obtained at 298.15 K. Zn(Met)2+ in solution w…     

The Synthesis and Biological Evaluation of Regioisomeric Benzothiazolyl Coumarins

Various 4-aryloxymethylcoumarins have been obtained by the r.t. allylic substitution with formylphenols. These have been further reacted with o-aminothiophenol resulting in the formation of a benzothiazole skeleton. These compounds have been synthesised with a view to study their potential as microbial growth inhibitors. Comparative studies on the spectral and antimicrobial activities have also been carried out.