Thermal cis-trans isomerization and photofading of some azo dyes in poly(ethylene terephthalate) matrices: A kinetic study

The thermal cis-trans isomerization of azo dyes XC₆H₄N=NC₆H₄N(C₂H₅)₂ (where X is H, OCH₃, CN, and NO₂) in poly(ethylene terephthalate) matrices, below the glass transition temperature, and in dibutylphthalate solutions has been studied kinetically in the temperature range 20–60°C. Kinetic behavior in the polymer is characterized by two or three simultaneous first-order processes with similar activation enthalpies. These processes reflect an unequal distribution of “tie-molecules,” “folds,” and “cilia” in the amorphous region of the polymer. Lightfastness of the dyes in poly(ethylene terephthalate) films has been investigated. Polymer morphology strongly affected the photofading, but no significant influence was observed in the kinetic experiments.     

Cell-free protein synthesis through solubilisate exchange in water/oil emulsion compartments

This work is aimed at finding conditions under which synthetic compartments used as cell models can fuse with each other and allow reagents contained in the different compartments to react. This goal seems to be best achieved by the use of water in oil emulsions (w/o) with dimensions in the range of 30-60 microm. In particular, cell-free EGFP (enhanced green fluorescent protein) synthesis takes place in Tween 80/Span 80 w/o emulsions, and the extent of the reaction can be monitored directly by fluorescence. The medium is mineral oil, containing 0.5 % v/v aqueous solution. Different premixing configurations of the components (plasmid, amino acids, E. Coli extract) are used and compared. The in vitro synthesis of EGFP in emulsion droplets proceeds for 1 h, and the yield is 7.5 ng microL(-1) protein. EGFP synthesis in aqueous solution takes place for at least 5 h. The yield is 10.5 ng microL(-1) protein after 1 h and 15.8 ng microL(-1) protein after 5 h. The results with the w/o emulsions show that solubilisate exchange takes place among the different water droplets, but it is not possible to demonstrate clearly that a true fusion takes place.     

The effect of sotalol hydrochloride therapy on atrial signal-averaged ECG in patients with paroxysmal atrial fibrillation

BACKGROUND: There has been a continuing public debate about assisted suicide and the proper role, if any, of physicians in this practice. Legislative bans and various forms of legalization have been proposed. METHODS: We mailed questionnaires to three stratified random samples of Michigan physicians in specialties likely to involve the care of terminally ill patients: 500 in the spring of 1994, 500 in the summer of 1994, and 600 in the spring of 1995. Similar questionnaires were mailed to stratified random samples of Michigan adults: 449 in the spring of 1994 and 899 in the summer of 1994. Several different questionnaire forms were used, all of which included questions about whether physician-assisted suicide should be banned in Michigan or legalized under certain conditions. RESULTS: Usable questionnaires were returned by 1119 of 1518 physicians eligible for the study (74 percent), and 998 of 1307 eligible adults in the sample of the general public (76 percent). Asked to choose between legalization of physician-assisted suicide and an explicit ban, 56 percent of physicians and 66 percent of the public support legalization, 37 percent of physicians and 26 percent of the public preferred a ban, and 8 percent of each group were uncertain. When the physicians were given a wider range of choices, 40 percent preferred legalization, 37 percent preferred "no law" (i.e., no government regulation), 17 percent favored prohibition, and 5 percent were uncertain. If physician-assisted suicide were legal, 35 percent of physicians said they might participate if requested--22 percent would participate in either assisted suicide or voluntary euthanasia, and 13 percent would participate only in assisted suicide. Support for physician-assisted suicide was lowest among the strongly religious. CONCLUSIONS: Most Michigan physicians prefer either the legalization of physician-assisted suicide or no law at all; fewer than one fifth prefer a complete ban on the practice. Given a choice between legalization and a ban, two thirds of the Michigan public prefer legalization and one quarter prefer a ban.     

Control and Virtual Reality Simulation of Tendon Driven Mechanisms

In this paper the authors present a control strategy for tendon driven mechanisms. The aim of the control system is to find the correct torques which the motors have to exert to make the end effector describe a specific trajectory. In robotic assemblies this problem is often solved with closed loop algorithm, but here a simpler method, based on a open loop strategy, is developed. The difficulties in the actuation are in keeping the belt tight during all working conditions. So an innovative solution of this problem is presented here. This methodology can be easily applied in real time monitoring or very fast operations. For this reason several virtual reality simulations, developed using codes written in Virtual Reality Markup Language, are also presented. This approach is very efficient because it requires a very low cpu computation time, small size files, and the manipulator can be easily put into different simulated scenarios.     

Intelligent environments for all: a path towards technology-enhanced human well-being

Universal Access in the Information Society - Emerging intelligent environments are considered to offer significant opportunities to positively impact human life, both at an individual and at a...     

Cellulosic materials: Structure and enzymatic hydrolysis relationships

Structural and morphological features of four different cellulosic materials have been deeped by X-ray, CP–MAS NMR, water retention, and specific surface area analysis. Hydrolysis time courses of two of these celluloses were followed by employing an enzymatic system consisting of a cellulase from Trichoderma viride and a cellobiase from Aspergillus niger. Experimental results were rationalized on the basis of a methematical model previously verified on the other two substrates. All the celluloses presented the same mechanistic framework involving product inhibitions. The most efficient pretreatment was found to be the dissolution of cellulosic material in the dimethyl sulfoxide–paraformaldehyde system and regeneration with ammonia. This treatment cancelled the memory of the initial structural order.     

Essential oil of Teucrium scorodonia L. ssp. scorodonia from Italy

The essential oil of the flowering aerial parts of Teucrium scorodonia L. ssp. scorodonia growing in Italy on Verrucano, was analyzed by GC and GC–MS. All the identified compounds were sesquiterpene hydrocarbons. The main ones were germacrene B (26.2%) and β-caryophyllene (25.2%).     

两自由度周转轮系机械效率分析公式的评议

本文采用Radzimovsky原始推荐的分式严格讨论后,证明用于计算两自由度周转轮系机械效率的不同方法的数值等效,本文还包括用某些公式的数据要求过多方面的讨论.     

Array-based transcriptional analysis of Clostridium sporogenes UC9000 during germination,cell outgrowth and vegetative life

The members of the genus Clostridium, including the spore-forming anaerobic bacteria, have a complex and strictly regulated life cycle, but very little is known about the genetic pathways involved in the different stages of their life cycle. Clostridium sporogenes, a Gram-positive bacterium usually involved in food spoilage and frequently isolated from late blowing cheese, is genetically indistinguishable from the proteolytic Clostridium botulinum. As the non-neurotoxic counterpart, it is often used as an exemplar for the toxic subtypes. In this work, we performed a microscopic study combined with a custom array-based analysis of the C. sporogenes cycle, from dormant spores to the early stationary phase.