Culture supernatant of Shiga toxin-producing Escherichia coli strains provoke fluid accumulation in rabbit ileal loops

In the present study, in order to get a better insight into the mechanism of action of cyclophosphamide (CY) in rheumatoid arthritis (RA), we monitored the changes in lymphocytes' expression of leukocyte function associated antigen 1 (LFA-1). A group of 28 patients with refractory severe RA were treated with CY and methylprednisolone (MO) intravenously. Using flow cytometry we evaluated the changes in LFA-1 molecule expression on peripheral lymphocytes. In the analyzed group of patients the proportion of LFA-1 "dim" cells was reduced. After the treatment the ratio was partly normalized. Twelve months after cessation of the therapy high proportion of LFA-1 "dim" was observed only among CY/MP treated patients. The changes were related to clinical improvement. Based on the obtained data, it seems, that the treatment affecting the expression of LFA-1 may slow down lymphocyte migration and by that limit chronic inflammation within the synovium.     

Co-Extraction — Selective stripping for the recovery of nickel and copper from the leach liquor of ocean nodules

Ferromanganese deep sea nodules of the Indian Ocean have recently been recognised as a potential source of metals like copper, nickel, cobalt and manganese. For the treatment of the sea nodules following the reduction roast-ammonia leach process, the leach liquor containing copper, nickel and cobalt was processed to separate and recover these metals by solvent extraction (SX) using 25% LIX 64N in kerosene. Almost quantitative extraction of copper and nickel was realized in a continuous run. During nickel stripping, the small amount of copper in the nickel solution was removed by incorporating a copper extraction step using 10% LIX 64N in kerosene. The purified pregnant nickel electrolyte was electrowon in a non-diaphragm cell. Copper was similarly recovered by electrowinning (EW). A closed circuit of SX-EW was run to produce cathodes of nickel and copper with energy consumptions of 3.85 and 2.01 kWh/kg for the respective metals.     

Model-Based Damage Identification in a Continuous Bridge Using Vibration Data

Damage often causes changes in the dynamic characteristics of a structure such as frequencies and mode shapes. Vibration-based damage identification techniques utilize the changes in the dynamic characteristics of a structure to determine the location and extent of damage in the structure. Such techniques are applied in this study to the Crowchild Bridge, a steel-free deck continuous bridge located in western Canada. While the numerical models of the bridge are correlated with the measured dynamic characteristics, computer simulation is used to study the identification of a number of different damage patterns, and the effects of measurement errors and incomplete mode shapes on the quality of results are evaluated. The effectiveness of some selected damage identification techniques is examined; the potential difficulties in identifying the damage are outlined; and areas of further research are suggested. A three-dimensional finite-element model and a simple two-dimensional girder model of the bridge have been constructed to study the usefulness of the selected damage identification methods. Another promising damage detection method proposed here is based on the application of neural networks that combines a vibration-based method.     

Electrical and dielectric properties of sol–gel derived mullite doped with transition metals

Highly crystallized mullite composite has been synthesized at 1000 °C and 1300 °C via sol–gel technique in the presence of transition metal ions such as cobalt, nickel and copper. The dielectric properties (dielectric constant, loss tangent and a.c. conductivity) of the composites have been measured at room temperature and their variation with increasing frequency and concentration of the doped metals has been investigated. The composite doped with nickel exhibits minimum dielectric constant of 3.15 at 0.002(M) concentration at a frequency of 1.5 MHz. Experimental data shows a linear increase in a.c. conductivity with increasing concentration of metal doping ions .The dielectric constant and loss tangent of the composites are within the range of requirements for commercial use in electronics.     

2011年全球前十大MEMS器件厂商排名

MEMS传感器除了传统应用如喷墨打印头、投影仪、麦克风、汽车等领域,它还广泛应用在手机、平板电脑等移动终端上,可为设备添加更多智能化功能。据IHS iSuppli公司的MEMS市场调查显示,2011年最大的十家MEMS厂商的合计营业收入为47亿美元,比2010年的42亿美元增长12%。德州仪器继续稳居全球最大的MEMS器件制造商地位,在激烈竞争中保住了冠军位置,惠普仍然屈居第二。十大MEMS厂商中其他几家按降序排列依次是博世、意法半导体、佳能、松下、电装、楼氏、ADI和爱普生。飞思卡尔半导体原来也位于十大厂商行列,但2011年排名第十一,跌出了前十之列。     

2012年苹果仍将是平板电脑销量冠军

虽然基于Android系统的平板电脑增长快速,但目前看来苹果仍将保持绝对领先的态势。随着英特尔超极本的推出以及Windows8面市,PC型平板或将成为平板市场上一股新的力量。据IHS iSuppli公司全球平板电脑市场追踪报告显示,2012年苹果公司将以其iPad系列产品轻松保持在全球平板电脑市场的绝对领先地位,尽管一众Android产品和基于PC的平板产品也在努力进入这个迅速增长的市场。今年包括媒体平板和PC型平板在内的平板电脑销量将增加到1.266亿台,比2011年的     

2011电视半导体市场增长势头减弱

由于价格压力沉重和电视销售低迷,去年电视主板上使用的半导体销售额萎缩,并迫使一些知名厂商永远退出该产业。不过随着新功能的推出,半导体企业仍存在增长机会。     

Knowledge-based systems using neural networks for electron beam welding process of reactive material (Zircaloy-4)

Bead-on-plate welding of zircaloy-4 (a reactive material) plates was conducted using electron beam according to central composite design of experiments. Its predictive models were developed in the form of knowledge-based systems in both forward and reverse directions using neural networks. Input parameters considered for this welding of reactive metals were accelerating voltage, beam current and weld speed. The responses of the welding process were measured in terms of bead width, depth of penetration and micro-hardness. Forward mapping of the welding process was conducted using regression analysis, back-propagation neural network (BPNN), genetic algorithm-tuned neural network (GANN) and particle swarm optimization algorithm-tuned neural network (PSONN). Reverse mapping of this process was also carried out using the BPNN, GANN and PSONN-based approaches. Neural network-based approaches could model this welding process of reactive material in both forward and reverse directions efficiently, which is required for the automation of the same. The performance of the neural network models was found to be data-dependent. The BPNN could outperform the other two approaches for most of the cases but not all in both the forward and reverse mappings.     

Binary Galois field based asynchronous scheduling protocol for delay tolerant networks

Wireless Networks - Neighbour discovery plays a crucial role for communication in sparsely dense mobile networks, especially in delay tolerant networks, where neighbour discovery latency is...