Loss of heterozygosity and overexpression of the p53 gene in ovarian carcinoma

Eight anticonvulsant drugs-including clonazepam, diazepam and phenobarbital-were tested for their effects on GABA-stimulated chloride uptake in rat cerebral cortical microsacs (unfiltered synaptoneurosomes). "Mid" and "high" therapeutic concentrations were screened, and, if significant enhancement was found, full concentration-response tests were done. In the initial screens, enhancement of GABA-stimulated uptake was found only with phenobarbital, clonazepam and diazepam. In subsequent concentration-response tests, the effects of phenobarbital were found to occur throughout the range of normal, anticonvulsant concentrations, whereas the effects of clonazepam and diazepam were observed only above the concentrations normally used for the chronic control of seizures or anxiety. These data suggest that phenobarbital's anticonvulsant effects are mediated via the GABAA receptor complex, but that the low-dose effects of the benzodiazepines may be mediated via some other mechanism.     

制造linezolid的过程

正本发明涉及到制造linezolid的过程,过程包括在水溶液介质中以碱为催化剂,分子式(Ⅱ)的水溶性酸加成盐化合物与乙酰卤化物或醋酐反应制得。     

寻求60%以上的热能效

在当今这个高度关注能源消耗的时代,已有的节能电机的热效率最高可以达到96%,电力驱动器可以达到95%,许多家电和消费类设备的效率也在日益提升。那么,到底是什么使得60%的热效率能够如此稀奇呢?     

无噪驱动

随着节能及其他优势的发展,可调速驱动在驱动设计和安装过程中必须最小化驱动发出的分裂电噪声。     

Characterization of yttria-stabilized zirconia thin films deposited by electron beam evaporation on silicon substrates

Structure, phase composition and electrical conductivity of thin yttria-stabilized zirconia (YSZ) films deposited by electron beam evaporation on a silicon (1 0 0) substrate at different temperatures i.e. room temperature (r.t.), 700 and 830°C, as well as the quality of the YSZ–Si interface have been investigated. The phase composition was verified by Raman spectroscopy and by infrared (i.r.) transmission measurements. The structure of films changed in agreement with their electrical conductivity depending on the deposition temperature. Both structure and thereby electrical conductivity were influenced by the high concentration of Y2O3 stabilizer used and by the post-deposition thermal treatment of films. The deposition temperature was also important in determining the quality of the YSZ–Si interface and hence the accessible sweep of the surface potential. The capacitance–voltage characteristics of the metal–insulator–semiconductor (MIS) structures incorporating YSZ films measured at r.t. showed hysteresis and positive shifts of the flat-band voltages. © 1998 Chapman & Hall     

Fault diagnosis of rolling bearing based on back propagation neural network optimized by cuckoo search algorithm

In order to improve the accuracy of rolling bearing fault diagnosis in mechanical equipment, a new fault diagnosis method based on back propagation neural network optimized by cuckoo search algorithm is proposed. This method use the global search ability of the cuckoo search algorithm to constantly search for the best weights and thresholds, and then give it to the back propagation neural network. In this paper, wavelet packet decomposition is used for feature extraction of vibration signals. The energy values of different frequency bands are obtained through wavelet packet decomposition, and they are input as feature vectors into optimized back propagation neural network to identify different fault types of rolling bearings. Through the three sets of simulation comparison experiments of Matlab, the experimental results show that, Under the same conditions, compared with the other five models, the proposed back propagation neural network optimized by cuckoo search algorithm has the least number of training iterations and the highest diagnostic accuracy rate. And in the complex classification experiment with the same fault location but different bearing diameters, the fault recognition correct rate of the back propagation neural network optimized by cuckoo search algorithm is 96.25%.

     

Single-channel blind estimation of arterial input function and tissue impulse response in DCE-MRI

Multipass dynamic MRI and pharmacokinetic modeling are used to estimate perfusion parameters of leaky capillaries. Curve fitting and nonblind deconvolution are the established methods to derive the perfusion estimates from the observed arterial input function (AIF) and tissue tracer concentration function. These nonblind methods are sensitive to errors in the AIF, measured in some nearby artery or estimated by multichannel blind deconvolution. Here, a single-channel blind deconvolution algorithm is presented, which only uses a single tissue tracer concentration function to estimate the corresponding AIF and tissue impulse response function. That way, many errors affecting these functions are reduced. The validity of the algorithm is supported by simulations and tests on real data from mouse. The corresponding nonblind and multichannel methods are also presented.     

Increased operating flexibility for superconducting magnetic energystorage systems through the use of self-commutation

In a superconducting magnetic energy storage (SMES) system, it is convenient to use a twelve-pulse converter as the electrical interface between the high-voltage transmission systems and the superconducting coil. The authors present a technique for the construction of a circular PQ diagram to analyze power flow for a converter and SMES. The method indicates that, if self-commutation is used, any operating state in the PQ plane may be attained. This flexibility in operating state implies that all operating conditions, from unity power factor to zero power factor lagging, are attainable in the rectifier as well as the inverter modes. The implications of this flexibility, including harmonic impact, are discussed