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991.
Hugo J. Cornelissen Jaap H. M. Neijzen Frank A. M. A. Paulissen Luc J. M. Schlangen 《Journal of the Society for Information Display》1999,7(1):37-41
Abstract— Novel color and monochrome reflective direct-view display configurations have been developed by combining light-scattering PDLC layers with dielectric reflectors. Diffuse reflectances comparable to white paper were achieved. 相似文献
992.
It has been shown that cocaine-induced convulsions and lethality appear to be mediated by serotonin and dopamine neurotransmission, respectively. However, many antidepressants considered for treatment of cocaine addiction target these monoamine systems and may thus amplify these toxic effects during relapse. In this study, the authors assessed whether pretreatment with antidepressants influences cocaine-induced toxicity in mice as well as the potency of these medications at cocaine-binding sites previously shown to be associated with cocaine toxicity. Overall, selective serotonin reuptake inhibitors (SSRIs) facilitated cocaine-induced convulsions but not lethality. Dopamine uptake inhibition facilitated cocaine-induced lethality, but not convulsion. The SSRI sertraline enhanced neither convulsions nor lethality and may be unique due to its high affinity for sigma receptors. These results have important implications for safe and effective addiction treatments. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
993.
Meylan Frank Kiatake Luis Gustavo G. Santos Marcelo Zanoni Kofuji Sérgio Takeo Courtiat Jean Pierre 《Telecommunication Systems》1999,11(3-4):305-321
This paper presents a comparative study of different techniques aiming at transmitting MPEG-2 streams over ATM networks, with emphasis on the presentation of practical results achieved on an experimental platform available at LSI, a laboratory of the University of São Paulo, Brazil. This study has the purpose to determine some tuning parameters for optimizing the implementation of distributed multimedia applications on different network technologies. The focus of this experimental study has been on non-native ATM techniques like “Classical IP over ATM” and “LAN Emulation”, as well as native ATM techniques based on direct access service primitives to AAL5. The influence of different parameters, like packet length, buffer size, CPU speed, on the resulting throughput has been studied. Furthermore, a testing tool is being developed for assessing the transmission of MPEG-2 streams based on the practical experience achieved so far. These results will permit the evaluation of different network technologies and also help in the development of distributed multimedia applications like video-on-demand, videoconferencing and telemedicine. 相似文献
994.
ML Mayer SJ Clark TR Konrad VA Freeman RT Slifkin 《Canadian Metallurgical Quarterly》1999,89(2):164-170
OBJECTIVES: This study assessed the influence of public policies on the immunization status of 2-year old children in the United States. METHODS: Up-to-dateness for the primary immunization series was assessed in a national sample of 8100 children from the 1988 National Maternal and Infant Health Survey and its 1991 Longitudinal Follow-Up. RESULTS: Documented immunization rates of this sample were 33% for poor children and 44% for others. More widespread Medicated coverage was associated with greater likelihood of up-to-dateness among poor children. Up-to-dateness was more likely for poor children with public rather than private sources of routine pediatric care, but all children living in states where most immunizations were delivered in the public sector were less likely to be up to date. Poor children in state with partial vaccine replacement programs were less likely to be up to date than those in free-market purchase states. CONCLUSIONS: While state policies can enhance immunization delivery for poor children, heavy reliance on public sector immunization does not ensure timely receipt of vaccines. Public- and private-sector collaboration is necessary to protect children from vaccine-preventable diseases. 相似文献
995.
This study examined the impact of hope in the future and school climate as protective factors in school dropouts and graduates. Participants consisted of 97 students (males and females, aged 14-21 yrs) at risk for not completing school in an urban area. At-risk status was determined by student assignment to a continuation high school, a special placement for students who had had numerous infractions at regular high schools. Retrospectively, dropouts rated perceived school climate significantly lower than graduates, and graduates rated the importance of attending college significantly higher than dropouts. Dropouts and graduates who left school after the study was conducted did not report differences on the risk factors measured, nor did they differ on perceived school climate or the importance of attending college. However, hope in the future significantly predicted dropout versus graduate status for these participants. Results are discussed as describing differences in retrospective versus prospective reports, and as evidence of the utility of the risk/resilience paradigm in school completion research. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
996.
Neural network identification of poets using letter sequences 总被引:1,自引:0,他引:1
Hoorn JF; Frank SL; Kowalczyk W; van der Ham F 《Literary and Linguistic Computing》1999,14(3):311-338
997.
998.
999.
Cole T.D. Frank L. Ballard B.W. Henshaw R.M. 《IEEE instrumentation & measurement magazine》1999,2(4):12-22
The primary drivers for space instruments are the environment and survivability, support assets, delivery cost, and lack of accessibility. Survivability deals primarily with environments, such as launch and depressurization, extremes of temperature, high vacuum, radiation, and hypervelocity impacts. The cost to deployment is directly coupled to launch services, which are inherently expensive. These costs are nonlinear functions of the mass and volume of satellite payloads. The “user interfaces” for space-borne instruments are high-cost assets because they include mission operations centers, satellite hacking station(s), and ground networks. All of these issues demand high reliability 相似文献
1000.
Bimetallic clusters containing gold in conjunction with Group 8 metals have been intensively studied as it is proposed that these compounds may find uses as catalysts or materials (or as precursors to catalysts/materials). These types of compounds are very difficult to characterize by the mass spectrometric techniques traditionally used to analyse transition metal clusters. In this paper we report a derivatization method employing electrospray ionization mass spectrometry that is reliable and informative for these types of compounds. 相似文献