An electrical network approach to the analysis of semiconductordevices

A simple electrical network is used to represent the five differential equations describing basic phenomena in one-dimensional semiconductor devices. Both standard and integrated approaches for solving transport equations are developed. Also, an electrical network equivalent for the nonlinear Poisson equation was derived. It allows students to better understand the physical phenomena and the process of computer simulation of such semiconductor devices     

各种状态的液体通过核孔膜的规律

介绍了液体通过核孔膜规律方面取得的新认识，包括：（１）纯净液体通过核孔膜的规律；（２）核孔膜测定液体粘滞系数的各种方法；（３）各种物质溶液浓度的核孔膜测定；（４）液相混合物快速分离和化学分离；（５）流体中固体微粒对核孔膜的堵塞及其公式；（６）用核孔膜滤除液中各各斩规律。     

集群系统与公用网互连的仿真模型和模拟算法

在讨论ＭＰＴ１３２７信令的集群移动通信系统与国内Ｎｏ．７信令的ＰＳＴＮ网间互连，帝现两种信令配合中，研究了集群系统的仿真模型和模拟算法，同时模拟出整个集群系统的工作情况，运行结果证实了所提方案的可行性与准确性。     

Pneumothorax. A complication of fine needle aspiration of breast tumors

Of 1,666 patients who underwent fine needle aspiration for breast lumps, 4 developed pneumothorax as a complication. The incidence of this complication in our patients is 1:417. The clinical manifestations were immediate chest pain, shoulder pain and, occasionally, dyspnea that developed later. Observation is sufficient treatment in most patients, and rarely is drainage of the pneumothorax required.     

Quantitative NMR spectroscopy by matrix pencil methods

The matrix pencil (MP) method, based on the singular value decomposition (SVD), is applied to quantitative NMR spectroscopy. Its relationship to other SVD-based methods is also presented. Simulations and applications are given to demonstrate the capability of superior performance.©1993 John Wiley & Sons Inc     

Myofibroblast accumulation induced by transforming growth factor-beta is involved in the pathogenesis of nasal polyps

Myofibroblasts that express alpha-smooth muscle actin (alpha-SMA) are detected in many chronic inflammatory diseases. Transforming growth factor-beta (TGF-beta) is a potent inducer of myofibroblast accumulation in tissues. In this study, scattered myofibroblasts and TGF-beta were quantified and localized in nasal polyps (NPs) and normal nasal mucosa (NM). NPs were sampled in 16 patients during ethmoidectomy and NM was obtained from 10 control subjects during rhinoplasty. alpha-SMA and TGF-beta were detected using immunohistochemistry and the numbers of labeled cells were quantified (alpha-SMA and TGF-beta indices) and compared between NPs and NM. In eight NPs, in which the pedicle was preserved, alpha-SMA and TGF-beta were evaluated and compared in the pedicle, central, and tip areas. Finally, TGF-beta expression was compared between low (zone 1), moderate (zone 2), and high (zone 3) zones of alpha-SMA positivity. alpha-SMA and TGF-beta indices were significantly higher in NPs than in NM. In the eight selected NPs, alpha-SMA-positive cells were significantly more abundant in the pedicle than in the central and tip areas, whereas TGF-beta-positive cells were significantly more numerous in the pedicle than in the tip area. The number of TGF-beta-positive cells was significantly higher in zone 3 than in zone 1 of alpha-SMA positivity. Myofibroblasts, which are abundant in NPs but rare in NM, could be involved in the growth of NPs by inducing extracellular matrix accumulation. The local development of myofibroblasts in NPs could be controlled by TGF-beta, locally produced by inflammatory cells.     

Galactolipase and chilling sensitivity of plants

We assessed the effects of a dietary protein restriction (5% vs. 20% casein in diet) initiated at conception and imposed during the first 2 weeks of rat gestation on postnatal brain development. At the end of the malnutrition period, protein-restricted animals exhibited significantly smaller fetal body weight and brain cortical thickness than controls. At birth and thereafter, body weight was normalized in the progeny. Similarly, brain weight and cytoarchitecture were normal in postnatal animals. In contrast, we observed, during the first 2 postnatal weeks, several abnormalities of brain development which affected all the studied areas for most of the studied parameters: (i) delayed astrocytogenesis as shown by a reduced GFAP staining; (ii) delayed production of hyaluronan in the extracellular matrix studied with binding of biotinylated hyaluronectin; (iii) abnormal neuronal differentiation as shown by reduced expression of MAP-5 and increased expression of MAP-1; (iv) abnormal synaptogenesis as shown by the increased expression of synaptophysin in the basal ganglia; (v) decreased programmed cell death. In adult prenatally protein-restricted animals, all the above parameters were normalized excepted MAP-1 labeling which remained high. In addition, we observed slight alterations of the ventilatory response to hypoxia in adult animals. The present study demonstrates that early protein malnutrition during embryonic development induces multiple, transient alterations of brain development. However, the almost complete normalization in adults of brain architecture and differentiation as well as our physiological data strongly suggest a remarkable plasticity of the developing brain following an early aggression.