Cyclic adenosine monophosphate content in the lymphocytes of cancer patients

Examinations have been carried out on 83 cancer patients (aged 34-72), 24 patients with atherosclerosis (aged 38-68) and 34 healthy persons (aged 20-69). The cAMP concentration decrease with age in lymphocytes of healthy persons is confirmed. This index in patients with lung carcinoma, breast carcinoma in remission and in patients with atherosclerosis was identical with that of healthy persons, but in patients with breast and corpus uteri carcinomas without metastases it was higher than in healthy persons of the similar age. The amount of cAMP in lymphocytes is compared with the magnitude of the blast transformation and with the amount of cholesterol in blood and lymphocytes in examined persons. The cAMP level in lymphocytes is observed to increase in the process of hyperlipidemia disappearance in cancer patients and in those with atherosclerosis.     

Regulatory reform in the broadcasting industries of Brazil and Argentina in the 1990s

Regulatory reform has changed the organization of the broadcasting industry in Brazil and Argentina in the past decade. Although responding to a similar set of pressure, the pace, instruments, and character of reforms have been different in the 2 countries, resulting in media markets of diverse natures. This study argues that these different policy outcomes in the reform of broadcasting regulation in Brazil and Argentina reflect variations in three factors: the nature of the political system, the structure of the existing broadcasting industry, and the ideological legacy in the regulation of communication industries. The case of regulatory reform in the broadcasting industry illustrates different policy patterns in the restructuring of state-industry relations in communications and information technology industries in the 2 neighboring countries.     

In situ off-axis electron holography of metal-oxide hetero-interfaces in oxygen atmosphere

Off-axis electron holography has been extended to in situ observations in gas atmospheres. The Yttria-stabilized zirconia (YSZ)-Pt hetero-interface was characterized by electron holography at high temperature in a vacuum and in an oxygen atmosphere. Analysis of the phase shift profiles revealed high mobility of anions in the oxide in the vicinity of the interface in the oxygen atmosphere. This would compensate for any increase in the number of oxygen vacancies in YSZ through the metal interface.     

基于2007-2013年COSMIC掩星数据的电离层振幅闪烁研究

利用2007-2013年的COSMIC掩星数据，分析了E区与F区电离层闪烁的变化特征.发现用闪烁出现频次、闪烁发生率以及闪烁强度来表征的电离层闪烁出现规律比较相似.E区电离层闪烁在夏季半球的中纬地区最强，其次是春秋季的低纬地区和冬季半球.就经度分布来说，春秋季E区电离层闪烁呈四波结构.对F区电离层闪烁来说:南美-大西洋扇区在12月至点最为显著；非洲和太平洋扇区在6月至点最为显著；大西洋扇区在春秋分季最为显著.极区也出现中等强度的闪烁，尤其在南半球的90°E~180°E扇区较为显著.高纬E区电离层闪烁强度随太阳活动的增强而增强，而低纬和南半球的中纬E区闪烁随太阳活动的增强而减弱.高纬和低纬F区闪烁随太阳活动的增强而增强，而中纬F区电离层闪烁对太阳活动无显著依赖关系.对于赤道区来说，北半球60°W~60°E经度区闪烁强度随太阳活动的变化最为显著，其次是南半球60°E~210°E附近；而对于高纬地区来说，F区闪烁强度随太阳活动的变化最为显著的区域在南半球60°E~210°E附近.     

Pioneering electricity reform in South America

The transformation in the electric energy sector in South America began in 1982, when Chile formalized an electric power reorganization. Argentina followed suit in 1992, then Peru in 1993, Bolivia and Colombia in 1994, and finally, Brazil and Venezuela. This article discusses the restructuring of power sectors in South America and Europe, and gives a viewpoint on the computerized grid-control needed in the new deregulated regimes     

一种X 波段数控移相收发组件的实现方法

相控阵雷达由于其波束扫描的快速性和稳定性、波束控制的灵活性、易实现多波束探测和跟踪、易实现波束锐化 等优点,已广泛应用于地面雷达,也是弹载雷达的一个重要发展方向。作者研制的数控移相收发组件实现了将射频移相 转至中频移相实现,具有低成本、体积小、相位变化灵活的特点。     

A Strategy for Broad-Band Network Introduction in Italy

Studies are being carried out in Italy concerning the strategy for the introduction in the 1990's of optical fiber systems in the distribution network, in order to supply customers with broad-band services (in particular with video services). This paper deals with some of the main choices that are being done, in particular in view of a field trial which is planned in Rome in 1988.     

Noise in solid-state devices and lasers

A survey is given of the most important noise problems in solid-state devices. Section II discusses shot noise in metal-semiconductor diodes, p-n junctions, and transistors at low injection; noise due to recombination and generation in the junction space-charge region; high-level injection effects; noise in photodiodes, avalanche diodes, and diode particle detectors, and shot noise in the leakage currents in field-effect transistors (FETs). Section III discusses thermal noise and induced gate noise in FETs; generation-recombination noise in FETs and transistors at low temperatures; noise due to recombination centers in the space-charge region(s) of FETs, and noise in space-charge-limited solid-state diodes. Section IV attempts to give a unified account of 1/f noise in solid-state devices in terms of the fluctuating occupancy of traps in the surface oxide; discusses the kinetics of these traps; applies this to flicker noise in junction diodes, transistors, and FETs, and briefly discusses flicker noise in Gunn diodes and burst noise in junction diodes and transistors. Section V discusses shot noise in the light emission of luminescent diodes and lasers, and noise in optical heterodyning. Section VI discusses circuit applications. It deals with the noise figure of negative conductance amplifiers (tunnel diodes and parametric amplifiers), and of FET, transistor, and mixer circuits. In the latter discussion capacitive up-converters, and diode, FET, and transistor mixers are dealt with.     

Interference effects in the electroreflectance and electroluminescence spectra of InGaN/AlGaN/GaN light-emitting-diode heterostructures

Interference effects in InGaN/AlGaN/GaN light-emitting-diode heterostructures of blue emission are studied by spectroscopy of electroreflectance and electroluminescence. The periodic bands observed in the electroreflectance and electroluminescence spectra in a blue spectral range are caused by interference effects in the structure in general. The emergence of interference fringes in the electroreflection spectra is explained by modulation of built-in electric fields in the active region of the heterostructure. The long-period interference fringes observed in the electroreflectance spectra in a wide spectral range from infrared to ultra-violet allows one to determine the location of the active region of the heterostructure with respect to different reflecting surfaces in the cavity.     

Dependence of photoinduced changes in photovoltaic and dark electrical properties of hydrogenated amorphous silicon diodes on changes in the film properties of hydrogenated amorphous silicon

Computer simulation of hydrogenated amorphous silicon (a-Si:H) p-i-n type or n-i-p type diodes has been used to clarify the relationship between the photoinduced changes in photovoltaic and dark electrical properties of a-Si:H diodes and those in a-Si:H film properties. The origins of observed decrease in the short-circuit current and the fill factor are discussed referring to the decrease in carrier lifetimes, the change in electric field distribution in the undoped layer reflecting the increase in the density of ionized gap states, and the increase in interface recombination velcoity. Possible reasons for the observed differences in the photoinduced changes in photovoltaic properties between p-i-n type and n-i-p type a-Si:H diodes are also discussed. The observed changes in dark current-voltage characteristics of a-Si:H diodes can originate from the decrease in carrier lifetime. Some comments are also made on the "bulk or surface problem" of the photo-induced changes in a-Si:H p-i-n or n-i-p diodes.     

Millimeter wave antennas

Major advances in millimeter-wave antennas have been made in recent years, in particular in two areas. A new class of leaky-wave antennas based on open millimeter waveguides has been proposed and investigated, and substantial progress has been achieved in integrated antennas where active and passive circuits, possibly in monolithic form, are combined with the radiating elements in one compact unit. Interesting developments have taken place also in a third group of millimeter-wave antennas, that of microstrip antennas and printed circuit antennas in general. An attempt is made to summarize these developments     

ANSYS在高功率横流CO2激光器流道温度场分析中的应用

本文采用有限元方法建立了高功率横流CO2激光器流道温度场数学模型,利用ANSYS再现了激光器稳定工作状态下流道温度场分布,提供了测定流道内部温度的新途径。     

Smad4蛋白在胃癌前病变中表达的研究

目的：观察Smad4蛋白在胃癌前病变组织中表达的特点。方法：应用免疫组织化学方法,对10例正常胃粘膜组织、21例胃癌前病变组织及62例胃癌组织中Smad4蛋白的表达进行了研究。结果：在正常胃粘膜组织,Smad4蛋白主要表达于胃腺体的体底部细胞胞浆中;在胃粘膜肠化及不典型增生组织,Smad4蛋白主要表达于胞浆中;在胃癌组织,Smad4蛋白主要表达于胞浆及少量细胞核中,其中在低分化腺癌组织表达明显减少（与正常胃粘膜组织、胃癌前病变组织及高分化腺癌组织相比,P〈0.05;P〈0.01;P〈0.01）。结论：Smad4蛋白在胃癌前病变组织中表达并未减少,但在低分化胃癌组织中表达减少,提示其表达减少在胃癌的发生发展过程可能系一晚期事件。     

A comparative study of assembly planning in traditional and virtualenvironments

Presents an experiment that investigated the potential benefits of virtual reality (VR) environments in supporting assembly planning. In the experiment, 15 subjects performed an assembly planning task in three different conditions: a traditional engineering (TE) environment, a nonimmersive desktop VR (DVR) environment, and an immersive CAVE (Cave Automatic Virtual Environment) VR (CVR) environment. The effects of the three conditions on the subjects' performance were analyzed. The subjects' performance time in the TE condition was significantly longer than that in the DVR condition and that in the CVR condition, whereas the difference in performance time between the DVR condition and the CVR condition was not significant. The total number of problematic assembly steps in the TE condition was significantly greater than that in the CVR condition. Specifically, the subjects' assembly sequences in the TE condition involved more reorientations than in the DVR condition. The number of difficult assembly steps in the TE condition was significantly greater than that in the DVR condition, which was significantly greater than that in the CVR condition. The number of dissimilar assembly steps in the TE condition was significantly greater than that in the CVR condition, which was significantly greater than that in the DVR condition. Hence, the results revealed advantages of the two VR environments over the TE environment in improving the subjects' overall assembly planning performance and in minimizing the handling difficulty, excessive reorientation and dissimilarity of assembly operations     

Fourth quarter 2009 IEEE communications surveys and tutorials

Welcome to the fourth issue of 2009 of the IEEE Communications Surveys and Tutorials. Paper in this issue survey the research effort in several areas such mobility in Wimax, mobility models in VANET, handoff in cellular networks, admission control in MANETS, physical impairments in optical networks, physical layer issues in the 802.11n standard as well as jamming in wireless sensor networks     

日本纳米科技专利公开势态与分析

分析了日本纳米科技专利的数量与领域的分布情况,介绍了日本产业界发展纳米科技的现状,为我国纳米科技研究工作者提供借鉴。     

Inventive payoff from R&D in Japanese industry: convergencewith the West

An attempt is made to determine if investment in R&D and the hiring of college-educated employees result in a higher rate of inventions. The relationship between the input of R&D and inventive output is studied in two samples of Japanese factories, 34 in 1982 and 44 in 1970. These results are compared with findings in a parallel American study. The correlations between R&D and inventive output are similar in Japan and America in the 1980s, despite some differences in the management of innovation in the two nations. Moreover, the most Westernized subsample of Japanese firms in the 1970s had correlations between R&D and invention similar to those observed in the American study. Thus, it is concluded that some degree of convergence may be taking place in R&D management strategies in the two nations     

Effect of photovoltage on current flow in metal-semiconductor schottky-barrier contacts

It is shown that changes in device characteristics and an increase in the light-to-electrical energy conversion efficiency in metal-semiconductor Schottky barrier contacts are associated with a peripheral electric field built into the contact. For contacts with longer perimeters, variations in device characteristics and the light-to-electrical energy conversion efficiency are significantly larger. Since the photovoltage and peripheral electric fields in the contact region are codirected with the intrinsic electric field of the space-charge region, contact illumination results in a larger increase in the “dead” zone in forward portions of current-voltage characteristics, a larger decrease in the effective Schottky barrier height, and an increase in the field electron emission. An increase in the reverse field emission under photovoltage leads to an increase in the recombination current in the space-charge region, which provides dc photocurrent flow in the circuit.     

Biomedical Engineering Education: Enrollment, Courses, Degrees, and Employment

During the 1979-1980 academic year a two-page questionnaire on biomedical engineering education was sent to 251 engineering schools. 71 schools indicated that they had degree programs and an additional 35 indicated that they had official minor or option programs, 107 did not have a program, and 38 did not respond. For schools offering degrees in biomedical engineering, there were 2859 students enrolled in 37 B.S. programs, 830 students in 48 M.S. programs, and 469 students in 41 Ph.D. programs. Options or minors in biomedical engineering with a degree in another engineering discipline were available at the B.S. level at 41 schools, at the M.S. level at 42 schools, and at the Ph.D. level at 34 schools. Over the past two years, schools offered 109 courses in biomedical instrumentation, 74 in computers in medicine, 162 in physiological systems/modeling, 60 in biomechanics, 47 in biomaterials, 33 in hospital internship, 23 in clinical engineering, 9 in biomedical engineering lab, and 67 in other areas. During the academic year 1978-1979, schools awarded 464 B.S. degrees, 249 M.S. degrees, and 107 Ph.D. degrees in biomedical engineering. Of these graduates, 253 found jobs in industry, 23 in government, 35 in academia, and 66 in hospitals or clinics; 100 went to medical school, 96 to biomedical engineering graduate schools, and 57 to other graduate or professional schools.     

一般综合性医院的空调设计标准问题

本文分析和介绍了北京12所医院及医疗单位的空气品质和ASHRAE空调设计标准,结果发现这些医院的空气品质多数不合格,说明一般综合医院空调系统存在许多问题。因此,我们应当制定严格的一般综合医院空调设计标准,尤其是门诊部的空调设计,从而从根本上控制医院感染。