Synthesis and characterization of cobalt nano‐particles through microwave polyol process

This article aims to synthesize and character cobalt nano‐particles through microwave polyol process. At first, cobalt acetate is used as precursor to synthesize cobalt nano‐particles by microwave assisted ethylene glycol in the presence of polyvinylpyrrolidone (PVP) as capping agent. As measured from ion‐coupled plasma (ICP) and thermo‐gravimetric analysis (TGA), the yields of as‐synthesized cobalt particles in average diameters of 40 and 81 nm verified by transmission electronic microscopy (TEM), are 71 and 85%, respectively; and the structure of as‐synthesized cobalt nano‐particle is a face‐center cubic structure analyzed by X‐ray diffraction (XRD). Finally, the as‐synthesized cobalt nano‐particle modified by oleic acid is dispersed in kerosene to character magnetic property. As measured by vibration sample magnetometer (VSM), the saturation magnetisms of cobalt nano‐particles with average diameters of 40 and 81 nm are 39.1 and 29.5 emu/g, respectively, in solution. © 2009 American Institute of Chemical Engineers AIChE J, 2009     

The Gastroprotective Effect of Naringenin against Ethanol-Induced Gastric Ulcers in Mice through Inhibiting Oxidative and Inflammatory Responses

Naringenin is a major flavanone found in grapes, tangelos, blood oranges, lemons, pummelo, and tangerines. It is known to have anti-inflammatory, antioxidant, anticancer, antimutagenic, antifibrogenic, and antiatherogenic pharmacological properties. This study aims to investigate the anti-inflammatory effects of naringenin in ethanol-induced gastric damage in vivo and ethanol-stimulated KATO III cells in vitro. Our results showed that pretreatment with naringenin significantly protected mice from ethanol-induced hemorrhagic damage, epithelial cell loss, and edema with leucocytes. It reduced gastric ulcers (GU) by suppressing ethanol-induced nuclear factor-κB (NF-κB) activity and decreasing the levels of nitric oxide (NO), malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-8 (IL-8), and myeloperoxidase (MPO). In addition, pretreatment with naringenin might inhibit the secretion of TNF-α, IL-6, and IL-8, as well as the proteins cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) via the suppression of NF-κB and mitogen-activated protein kinase (MAPK) signaling in ethanol-stimulated stomach epithelial KATO III cells. Together, the results of this study highlight the gastroprotective effect of naringenin in GU of mice by inhibiting gastric secretion and acidity, reducing inflammation and oxidative stress, suppressing NF-κB activity, and restoring the histological architecture. These findings suggested that naringenin has therapeutic potential in the alleviation of ethanol-induced GU.     

The Role of microRNAs in Development of Colitis-Associated Colorectal Cancer

Colorectal cancer (CRC) is the third most deadly cancer worldwide, and inflammatory bowel disease (IBD) is one of the critical factors in CRC carcinogenesis. IBD is responsible for an unphysiological and sustained chronic inflammation environment favoring the transformation. MicroRNAs (miRNAs) belong to a class of highly conserved short single-stranded segments (18–25 nucleotides) non-coding RNA and have been extensively discussed in both CRC and IBD. However, the role of miRNAs in the development of colitis-associated CRC (CAC) is less clear. The aim of this review is to summarize the major upregulated (miR-18a, miR-19a, miR-21, miR-31, miR-155 and miR-214) and downregulated (miR-124, miR-193a-3p and miR-139-5p) miRNAs in CAC, and their roles in genes’ expression modulation in chronic colonic-inflammation-induced carcinogenesis, including programmed cell-death pathways. These miRNAs dysregulation could be applied for early CAC diagnosis, to predict therapy efficacy and for precision treatment.     

A Chinese sky trust?: Distributional impacts of carbon charges and revenue recycling in China

The introduction of carbon charges on the use of fossil fuels in China would have a progressive impact on income distribution. This outcome, which contrasts to the regressive distributional impact found in most studies of carbon charges in industrialized countries, is driven primarily by differences between urban and rural expenditure patterns. If carbon revenues were recycled on an equal per capita basis via a ‘sky trust,’ the progressive impact would be further enhanced: low-income (mainly rural) households would receive more in sky-trust dividends than they pay in carbon charges, and high-income (mainly urban) households would pay more than they receive in dividends. Thus a Chinese sky trust would contribute to both lower fossil fuel consumption and greater income equality.     

A NUMERICAL SCHEME FOR NON-FOURIER HEAT CONDUCTION,PART II: TWO-DIMENSIONAL PROBLEM FORMULATION AND VERIFICATION

A flux-splitting algorithm based on the Godunov numerical scheme developed for the solution of the one-dimensional non-Fourier heat conduction equation by Yeung and Lam [1] is extended for the investigation of thermal wave propagation in rectangular media. The derivation of the solution method and the stability criteria are presented in detail. Physical problems subjected to various boundary conditions (e.g., first, second, and third kinds) can be studied with the numerical scheme. A comparison of the exact solution with the one calculated by the proposed procedure is presented to confirm the validity of the numerical procedure. The numerical scheme is applicable for the study of short-pulse heating in advanced materials, microstructures, thin films, semiconductor devices, and superconductors.     

Distance learning in advanced military education: Analysis of joint operations course in the Taiwan military

High-ranking officers require advanced military education in war tactics for future combat. However, line officers rarely have time to take such courses on campus. The conventional solution to this problem used to take the inefficient correspondence courses. Whereas Internet technologies progress, online course is the current trend for military training. However, the question is what distance learning methodology best suits such a proprietary learning purpose.This study presents a sequential process of developing distance learning courses in advanced military education. Further, the Petri-Net analytical approach is adopted to discover the essential interaction requirements of advanced military education delivered via Internet. This study developed a systematic method for designing e-learning systems according to specific requirements of target courses. The proposed approach starts by comparing on-campus programs with the existing e-learning systems to identify the steps required to transform the program into an e-learning system. After first outlining the pedagogy of the on-campus program, its proposed teaching flow through the Internet is then sketched. Finally, the Petri-Net model was used for in-depth analysis of the stages affecting the learning curve of the line office taking e-learning courses. The example of a “Joint Operations” AME course elaborated the presented approach. An e-learning system prototype was also designed accordingly. Lastly, an experiment was conducted to verify the efficiency of the presented approach.     

利用麦克风数组抑制背景噪声

概述随着手持语音通信设备越来越流行,它们应用在嘈吵环境的机会也越来越高,例如机场、交通繁忙的路段、人多嘈杂的酒吧等。在这种嘈吵的环境下,通话的双方实在难以听清对方所说的话。