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31.
To prevent post-transfusional hepatitis B and C, two epidemiologic studies were performed. The first, based on the frequencies distribution of hepatitis B virus serological markers versus sex and classes of age, has permitted the assessment of the profile of the infection in a population composed of 573 north vietnamese blood donors. There is no significant difference between men and women frequencies of HBs antigen (11.5%), anti-HBs antibody (70.2%) and anti-HBc antibody alone (3.8%), but a significant difference of no-marker frequencies: 7.8% and 17.9% in men and women respectively (X2 = 9.11; p = 0.010). The percentage of no-marker decreases when the mean age of each class increases. The second, using the increase of the serum alanine aminotransferase (ALAT) activity as an indirect marker of non-A, non-B hepatitis for determining in a population of more than 25,000 parisian blood donors, the percentage of donors eliminated. They are between 0.70 and 0.76 in women and 2.26 and 2.46 in men. These investigations can be applied to prevent the hepatitis B transmission in a population of 102 south vietnamese women in age to procreate or to determine the percentage of blood donors eliminated (3.12%) in a population of 2,950 Parisians composed in majority (50.9%) of new donors. The hemobiologist will have an important role to elaborate strategies for orientation of blood gifts with hepatitis B and C virus markers. 相似文献
32.
F Douaud N Le Roch J Renault R Havouis M Vaultier JP Moulinoux N Seiler 《Canadian Metallurgical Quarterly》1997,12(8):621-633
Several dimethylsilane tetramines [homologs of spermine with an Si(CH3)2 group in the central carbon chain], a carbon analog of the dimethylsilane tetramines [containing C(CH3)2 instead of Si(CH3)2] and a dimethylsilane hexamine were studied with regard to their cytotoxic activity and their ability to interact with double-stranded DNA. All polyamine analogs exerted cytostatic effects to several cell lines at micromolar concentrations. Their ability to condense DNA was comparable to and their ability to displace ethidium bromide from binding to DNA was superior to that of spermine. Their cytostatic effect was not correlated with the depletion of cellular spermidine concentrations. It is suggested that the new polyamine analogs act mainly by displacing spermidine from binding sites which are essential for the promotion of cell growth. 相似文献
33.
Le C.T.C. Ishimaru A. Kuga Y. Yea J.-H. 《Geoscience and Remote Sensing, IEEE Transactions on》1998,36(1):61-71
The polarimetric angular memory effect is applied to obtain the average topographic height of a rough surface. This novel effect improves the height sensitivity while maintaining a good degree of correlation between the sensors. By using a reference flat surface, the interferometric phase is linearly related to the mean topographic height. The combination of angular memory and wideband frequency interferometry (AMFI) is realized and offers a means to design a robust interferometric system. Extension of the technique to the pulse scattering problem is studied through the two-frequency mutual coherence function, and its time-domain transform provides an equivalent way to obtain the mean topographic height by combining both spatial and temporal diversity. Millimeter-wave (MMW) experiments are conducted with rough surfaces of different statistics and scattering media of different types (gravel, sand, and rough surfaces) to prove the effectiveness of the technique 相似文献
34.
Industries in the US continue to lose ground in international competition. If IS is to help change that trend, it will have to become more creative. Creativity improvement programs are being introduced in other areas of the company— now is the time for IS organizations to follow suit. 相似文献
35.
A clear understanding of the concept and consequences of diversity in science and technology is a key issue for Europe, when considering the current debate on cohesion Put forward within the Single European Act. According to Article 130B of the Single Act, all European policies, including technological policies must contribute to the achievement of a greater cohesion throughout the EC. The European market is generally presented as mainly a patchwork of national or even regional characteristics, with compartmentalized niches, and specific regulations. But does cohesion mean decreasing disparities between regions, which in such case signifies a passive policy of reallocation of resources within the EC, at the risk of generating uniformity? Or, does cohesion mean integration of all innovative and creative efforts, which implies a more complex policy of stimulation, under the condition to maintain a certain diversity? Must the governments systematically reduce diversity, or on the contrary must they enlarge diversity? How can they distinguish between negative and positive aspects of diversity? How do they operate a trade off between economies of scale and economies of diversity? To try to answer these political issues and to set up a coherent industrial policy at the EC level, a careful analysis of the sources of diversity, of the mechanisms that generate or reduce diversity, of the ways to valorize diversity are discussed in this paper 相似文献
36.
Patrick R. Taylor Ph.D. Milton Manrique Ph.D. 《JOM Journal of the Minerals, Metals and Materials Society》1996,48(6):43-45
Due to several inherent advantages, plasma processing technology may become a very useful tool in the production of new materials. An increasing research effort based on experimental as well as theoretical investigations has been invested in this area for the synthesis of advanced materials. In describing the thermal-plasma processing technique, this article employs examples from research at the Plasma Processing Laboratory at the University of Idaho. 相似文献
37.
38.
简单介绍了碳氧比测井的原理及通常的数据处理方法。分析了由常规数据处理所得曲线仍然存在的问题及可能的成因 ,并给出了可行的修正办法。讨论了另一种可行的曲线异常数据的检测、剔除方法。实践表明 :文章讨论的两点建议都是可行的 ,并且在提高测量曲线质量的同时也提高了地层含油饱和度的解释精度。 相似文献
39.
论述了电磁铁铁芯 (硅钢片 )模具的设计要点及其线切割加工的技巧 ,提出了提高模具加工精度和使用寿命的有效措施。 相似文献
40.
Juey H. Lai Curtis Knudson Leander Hallgren Richard B. Douglas Patrick Griffin 《Polymer Engineering and Science》1985,25(12):778-781
This paper reports the effect of humidity and temperature on the adhesive strength of a pressure sensitive adhesive (Flexbond 150) used to bond Mylar films. It has been found that, ill general, the adhesive strength decreases significantly with an increase in temperature. The effect of humidity on the bonding strength, however, was found to be process dependent. The sample preparation conditions, e.g., press weight for the bonding and the press time, are important in determining the humidity effect. The water sorption isotherm A 24°C for the adhesive was also determined. The amount of water sorbed by the adhesive at 95 percent relative pressure was found to be less than one weight percent. 相似文献