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91.
92.
为多媒体应用选择一款合适的处理器是一项很复杂的工作,其原因之一就是从视频源到显示器之间需要多个高速连接,而且通常很难找到能处理高速数据流接口的完美组合。  相似文献   
93.
Presented 33 elementary teachers and 50 female community college students (all of whom varied in French-English bilingual dominance and experience) with (1) pictures to be labeled in English, (2) French words to be translated into English, and (3) English nouns to be copied as they were. Later, Ss were unexpectedly tested for recall. Results replicate and extend those of A. Paivio and W. E. Lambert (see record 1982-09020-001), demonstrating a 3.3:2.4:1 ratio of recall for images to translation equivalents to copying. Results support bilingual dual coding theory as proposed by Paivio and A. Desrochers (see record 1982-02758-001). (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
94.
Desogestrel is a 3-deoxo progestogenic steroid that requires bioactivation to 3-ketodesogestrel. In these studies we have attempted to define the pathway of 3-ketodesogestrel formation and characterise the enzymes responsible for this biotransformation in vitro. Initial studies using deuterated desogestrel confirmed that desogestrel is metabolised by human liver microsomes via 3alpha-hydroxy and 3beta-hydroxydesogestrel to 3-ketodesogestrel. Metabolites were analysed by radiometric high-performance liquid chromatography and were identified by liquid chromatography-mass spectrometry and by cochromatography with authentic standards. Desogestrel was metabolised by microsomes from lymphoblasts containing cDNA-expressed CYP2C9 and CYP2C19 to 3alpha-hydroxydesogestrel with small amounts of 3beta-hydroxydesogestrel also being observed. The Km value for 3alpha-hydroxylation by CYP2C9 cell line microsomes was 6.5 microM and the corresponding Vmax value was 1269 pmole. mg-1. min-1. Sulfaphenazole potently inhibited 3alpha-hydroxydesogestrel formation by CYP2C9 microsomes with a Ki value of 0.91 microM. There was a significant negative correlation between 3-ketodesogestrel and CYP3A4 content/activity in a panel of human livers suggesting that the further metabolism of 3-ketodesogestrel is mediated by CYP3A4. Sulfaphenazole partially inhibited 3alpha-hydroxydesogestrel and 3-ketodesogestrel formation in human liver microsomes indicating a possible in vivo role for CYP2C9. In addition, when sulfaphenazole was combined with S-mephenytoin, further inhibition of 3alpha-hydroxydesogestrel formation was observed suggesting a possible role for CYP2C19. This was confirmed in incubations with inhibitory antibodies. Whereas an anti-CYP2C9/2C19 antibody completely abolished desogestrel metabolism, anti-CYP3A4 and anti-CYP2E1 were not inhibitory. We conclude that CYP2C9 and possibly CYP2C19 and important isoforms catalysing the initial hydroxylation of desogestrel.  相似文献   
95.
96.
Heart rate variability (HRV) is a suitable diagnostic tool in identifying patients with autonomic nervous system (ANS) disorders even in pre-clinical stage. We have enrolled in this study all patients with large variety of connective tissue disorders, given the possibility of an involvement of ANS in these diseases. The study population consisted in eighty-five patients (68 females and 17 males), 35 of whom affected by systemic lupus erythematosus, 16 by rheumatoid arthritis, 14 by Sj?gren syndrome, 12 by progressive systemic sclerosis, 3 by Beh?et syndrome and 5 by antiphospholipid antibodies syndrome. The mean age ranged between 33.7 of patients with lupus erythematosus and 51.8 of those with Sj?gren syndrome. As control, we enrolled healthy subjects of different age, divided into two groups, to rule out the aging as potential source of considered parameters alteration. The autonomic function has been evaluated by 24 hours ambulatory monitoring, using a Zymed 1210 Scanner with Zymed 3.74-PC 1990 software. We have considered: in the time domain, the standard deviation of the RR intervals average (SDNN) and the percentage of RR adjacent intervals differing each other more than 50 msec (pNN50); in the frequency domain, the low (LF) and high (HF) frequencies, the LF/HF ratio, and the total power (RT). The HRV parameters resulted abnormal in every type of the connective tissue diseases considered: particularly SDNN, pNN50, LF, HF and RT (p < or = 0.01). In conclusion: the results of our study suggest that autonomic neuropathy may be present in any kind of connective tissue disorders even in preclinical stage.  相似文献   
97.
Measurement of the inertia tensor: An experimental proposal   总被引:1,自引:0,他引:1  
The presence of robots in advanced automated processes relies on the use of end-effectors capable of picking up and manipulating objects with different geometrical and mechanical characteristics. The position of the centre of mass and the inertia tensor are some of the parameters necessary for the design of gripping devices and especially for a dynamic study of manipulation.

This paper describes the experimental setup used to measure the inertia tensor and the position of the centre of mass of unpredefined objects. The unit employed is equipped with transducers and accelerometers, and is capable of recording the dynamic response of an unpredefined object to a known motion. The data are acquired by means of a multiprogrammer and are then processed by a personal computer. The computer thus provides the components of the principal tensor of inertia, the direction cosines of the principal reference frame with respect to a predefined barycentric system, and the position of the centre of mass. After defining the measurement set the experimental unit relied on, the paper goes on to present the expressions for the measurement errors made in estimating the parameters considered.  相似文献   

98.
There have been many cholera outbreaks in Senegal since 1971. The last outbreak began in the Dakar region in August 1995. It spread to the Diourbel, Fatick, Saint-Louis and Thies regions. In January 1996, the outbreak hit the Niakhar study area in the Fatick region. A team from ORSTOM (the French Institute of Scientific Research for Development in Cooperation) has been recording demographic events in this area for almost 15 years. The geographic approach is based on the automated mapping of cholera in hamlets and villages. Such studies investigate the factors determining the spread of diseases, within the context of land use. Three sets of data were used: demographic data that had been routinely collected and were available from a database, digitized maps and epidemiological data from a surveillance system set up to monitor the outbreak. A series of incidence maps, over time and on various scales, were generated using specialized software. The maps were analyzed and the outbreak was found to be heterogeneous over time. There were two waves of the outbreak and differences according to age and gender. The degree of heterogeneity depended on the place of residence. Heterogeneity was probably determined by village size, roads and the concentration of inhabitants within hamlets, which is roughly equivalent to the number of people per bore hole. These preliminary results suggest that further research is necessary, looking at different geographical scales (e.g. households, districts and regions). Qualitative studies of water use and the organization of the water supply are also required.  相似文献   
99.
100.
Controlled changes in crystallization conditions and shear history prior to and following both extrusion and compression molding were shown to drastically alter the mechanical properties of the polymer studied. This material, Poly[3,3-(bischloromethyl) oxacyclobutane], is an essentially linear polymer with a number average molecular weight of 300,000. The effect of heat transfer, as limited by experimental conditions, had a primary influence upon the crystallization phenomenon and therefore also upon the morphology and the resultant mechanical properties. By proper selection of processing conditions it was possible to alter the mechanical properties of this polymer from brittle behavior to the ability to form a neck and draw to high degrees of elongation. Using conditions that imparted the ability to neck and draw, it was shown that this process is sensitive to both strain rate during testing and extrusion rate during processing. The underlying cause of the effects upon mechanical properties appear to be the dramatic changes occurring in morphology as a result of the selected processing conditions. A chemical etching agent was used on these samples prior to replication, and observation in the electron microscope. Using this technique the internal morphology was studied and compared to the surface morphology. There was not a gradient of morphology in these samples. Furthermore, the use of this etching agent that attacked non-crystalline regions preferentially, suggested that the lamellar fine structure of spherulites is composed of smaller units.  相似文献   
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