The effect of an H2-receptor antagonist on small-bowel colonization and bacterial translocation in newborn rats

Bacterial translocation (BT) is defined as the passage of enteric bacteria from the gastrointestinal tract to extraintestinal tissues. Bacterial overgrowth is one of the main promoting factors of BT, which is thought to play an important role in the pathogenesis of sepsis and necrotizing enterocolitis. It is believed that small-bowel colonization is established by bacterial spread through the rectum. Gastric acid is also involved in this process. An experimental study was designed for investigating the effect of gastric acid inhibition with the use of an H2-receptor antagonist on intestinal colonization and BT in newborn rats. Animals were divided into two groups: the ranitidine group (n = 20) received ranitidine 10 mg/kg per day intramuscularly for 5 days; the control group (n = 30) received saline solution. Mesenteric lymph node, spleen, liver, stomach, small bowel/cecum, and large bowel specimens were obtained from each rat 5 days later and gram-negative and -positive aerobic bacteria identified by the use of chocolate and Endo agar. It is concluded that: (1) there was a strong correlation between gastric and small-bowel bacterial colonization in the ranitidine group; (2) no correlation between large-and small-bowel colonization could be demonstrated; and (3) BT occurred only in the ranitidine group.     

矿山设备润滑磨损状态智能分析技术

综合应用统计分析、预测理论、模式识别、神经网络和专家系统等多项技术，针对德兴铜矿设备状态监测的实际情况。研究设备润滑磨损状态智能分析技术。     

The adenomatoid odontogenic tumor: an analysis of 57 cases in a black African population

PURPOSE: This study analyzed the findings in a large series of adenomatoid odontogenic tumors (AOT) in Nigerians. PATIENTS AND METHODS: Hospital records of all cases of AOT diagnosed at three teaching hospitals were reviewed and analyzed. RESULTS: Most of the tumors were intraosseous (central) (98.3%) and of the follicular type (75%). Females were more frequently affected than males (1.4:1), and patients in their second decade of life were most frequently affected (75%). Patients with follicular AOT were relatively younger (15.2 +/- 5.6 years) than those with extrafollicular tumors (20.9 +/- 13.8 years). However, males who presented with extrafollicular tumors (14.6 +/- 3.9 years) were relatively younger than their female counterparts (24.9 +/- 16 years). The maxilla was affected nearly twice as often as the mandible (1.8:1), and the canine tooth was frequently embedded in the tumor (76.9%). Although follicular tumors were most frequently located in the maxilla (76.3%), extrafollicular tumors were more commonly found in the mandible (69.2%). CONCLUSION: The distribution of this tumor in black Africans does not appear to be substantially different from that reported in caucasians.     

经过优化的用于可再生能源系统的大功率逆变器

可再生能源市场正从全球金融危机中强劲反弹。先前延误或停工的项目已重新启动,许多新项目正在实施。这一高潮有力地掀起了整个供应链对可再生能源系统组件的需求,包括风力发电和光伏逆变器。全球风能理事会（GWEC）预测未来4年总装机容量的年均增长率为20.9%。这将使得到2014年风电总装机容量增加一倍以上,超过400GW。     

软特性650V IGBT：低电磁干扰和电压尖峰的优化器件

近年来,功率半导体厂商致力于提高器件的开关速度,这带来了开关损耗降低和系统能效提升的益处。这些功率器件需要优化的直流电路寄生电感（Ls）。为了满足具有大电流的高功率应用的需求,推出了一种全新的芯片650V IGBT4,旨在提供更大的设计自由度。这款全新的IGBT4器件具备更好的关断软度,并且由于关断电流变化率di／dr...     

改进的开关性能：快速IGBT带来新的挑战

降低动态功耗需要快速地开关功率半导体,但是,快速开关IGBT带来的新挑战,就是对关断电压峰值有特别强烈的影响。关断过程中uce-和ic测量分析说明了直流母线寄生电感和模块电感之间的相互作用。这使得在给定的应用中非常容易分析出的薄弱环节并在模拟中发现最大的潜力。     

核科技报告编写规则

规定了核科技报告编写的基本要求和格式。该规则全部或部分适用于学位论文、学术论文、年报等科技文件,也适用于技术档案。     

Strength analysis of concentration-inhomogeneous materials under tension

Within the framework of the statistical model of structurally inhomogeneous continua in the mechanics of deformable solids we suggest a numerical method for the analysis of fracture stresses in concentration-inhomogeneous materials under tension. Examples of the computation of fracture stresses are presented for some powder steels.Translated from Fiziko-Khimicheskaya Mekhanika Materialov, Vol. 31, No. 1, pp. 122–127, January – February, 1995.