美国中东政策评析

美国在中东遇到大麻烦,主要战略目标未能实现。伊拉克安全形势持续严峻,巴以和谈停滞不前,伊朗核问题难以解决,压叙利亚屈服迄未奏效,恐怖活动越反越多,大中东改造计划受挫。美遇到的困难未超出其承受能力,美国在中东仍居主导地位,美中东政策在手法和策略上有所调整,实质上并无变化。     

A reaction route graph analysis of the electrochemical hydrogen oxidation and evolution reactions

The reaction route (RR) graph approach recently developed by us for complex, non-linear kinetic mechanisms is applied to the hydrogen oxidation and evolution reactions. A corresponding RR graph is constructed and translated into an equivalent electrical circuit network by associating each elementary step with a characteristic resistance for the steady-state case and considering the overall reaction as a power source. It is further shown that the steady-state kinetics of the reaction can be investigated employing the conventional methods of the electrical network theory. Using a set of rate constants for the hydrogen evolution reaction (her) in alkaline solutions from the literature, the dominant RRs are identified and simplified mechanisms and kinetics derived.     

五所医院特需医疗服务状况调查

通过对上海医科大学附属华山医院、协和医院、北京同仁医院、中山医科大学附属第一医院、浙江医科大学附属第二医院开展的特需医疗服务情况的调查，论述了五所医院的具体做法，在对调查结果进行分析的基础上，就特需医疗服务的管理提出了建议。     

Postembryonic development of tapeworms — source of novel phylogenetic characters for analysis of cestode evolution: comparative TEM studies

Summary Ultrastructural features of juvenile cestodes (metacestodes) can provide useful characters for phylogenetic and evolutionary analyses. Until now, however, they have been relatively little utilised (Beveridge 2001, Chervy 2002). The postembryonic development and structure of fully formed metacestodes were examined in two cyclophyllideans: Taenia parva Baer, 1926 (Taeniidae); and Sobolevitaenia verulamii (Mettrick, 1958) Korniushin, 1972 (Dilepididae). In T. parva, three developmental stages were recognized: (1) an early stage of exogenous budding at the surface of the central vesicle; (2) a stage of polycephalic cyst development accompanied by segmentation of the growing metacestode strobila and an obvious decrease in the size of the central vesicle; (3) a fully formed metacestode of the strobilocercus type with 14–24 invaginated scoleces. The tegument, scolex, subtegumental musculature of the strobilar segments, protonephridial system, calcareous corpuscles and medullary parenchyma of larvae exhibit general similarity to the same structures in adults at both LM and TEM levels. The morphogenesis of the metacestode of T. parva is compared with that of polycephalic metacestodes of other Taenia spp. (T. krepkogorski, T. twitchelli and T. endothoracica) and with other asexually multiplying metacestodes (Mesocestoides vogae, hymenolepidids and dilepidids). In S. verulamii, the body of the cysticercoid with invaginated scolex armed with a double crown of rostellar hooks was completely surrounded by the cercomer, which appears to be separated from the cyst and scolex. The surface of the suckers is covered with a thick layer of glycocalyx. Five cell types were distinguished in the sections: (1) perikarya of metacestode tegument; (2) glycolgen-storing parenchymal cells; (3) glandular-type cells with large, electron-dense secretory-like granules; (4) flame cells; and (5) calcareous corpuscle-forming cells. The surface of the cercomer is covered by elongated microvilli, which evidently differ from characteristic microtriches covering all other parts of the metacestode surface. The ultrastructure of S. verulamii evidently differs from that of the other dilepidid cestode examined to date, Lateriporus geographicus, the cyst wall of which more resembles cysticercoids of Hymenolepididae than those of Dilepididae. Concluding remarks: Ultrastructural studies on metacestodes have considerable promise for providing important new characters for phylogenetic analysis. New TEM data on a great variety of cestode species are urgently needed. Until now, this field has not been exploited in a systematic fashion. Until more comprehensive studies become available, the current data are not yet amenable to analysis.     

Economic appraisal of laser applications in health care. Report of a project

This article reports on the results of a project evaluating effectiveness and cost-effectiveness of laser applications in health care. The literature was collected, emphasizing well-designed clinical trials and cost-effectiveness analyses. Few randomized clinical trials (RCTs) have been done outside the specialty of ophthalmology. Even fewer cost-effectiveness studies have been done, despite the frequent claims of cost-effectiveness in the medical literature. Review papers were commissioned, and a group of laser experts, economists, and policy-analysts met for 2 days to discuss the policy implications of lasers. The main conclusion from the conference is that inappropriate and unskilled use of lasers is presently the greatest problem with their application in health care.     

A study of the interrupted REM episode

Brief interruptions of REM sleep are considered to be part of the REM episode. The maximum allowable duration of such an interruption, which is used to define the end of the REM episode, is currently a matter of debate. Making measurements on individual REM cycles, inter-REM interval analysis was carried out to determine whether the generally adopted 15 minute empirical rule for this maximum needs to be extended to 25 minutes as suggested by several including Kobayashi et al. Our results show that there is no reason to alter the 15 minute rule and that measurements which do not take into account the time-of-night effect may be misleading. The proportion of interrupted REM episodes observed in our population of healthy adults is high. We have therefore also examined in some detail the phenomenology of the temporal evolution of the structure and content of the interrupted REM episodes. Both showed a definite change over the night: the interruptions in the earlier episodes tend to return the system to slow wave sleep while those in the later episodes tend to return it to wake. It is hypothesized that these interruptions reflect a measure of REM sleep pressure and its interaction with both slow wave sleep and wake pressures.     

Evolution and path models in human behavioral genetics

The evolutionary implications of the path-analysis model most often used in human behavior genetics are examined. With directional selection, a model of pure vertical environmental transmission does not respond in a fully adaptive fashion. Unless the coefficients of transmission are exactly 0.50, the population mean will not equilibrate at the selective optimum over time. If there is both genetic and vertical environmental transmission, then the population mean can equilibrate at the selective optimum. In the presence of genetic transmission, vertical environmental transmission increases population fitness and has a strong effect on the rapid movement of the mean toward the selective optimum. This raises the intriguing paradox of why empirical evidence suggests that vertical environmental transmission is usually small when it possesses such important fitness properties.This work was supported in part by Grant DA05131 from the National Institute on Drug Abuse.     

Delivering syringe exchange services through “satellite exchangers”: the Sacramento Area Needle Exchange, USA

An important operational aspect of Syringe Exchange Programmes (SEPs) is the venue of service delivery. This report describes the programmatic features of the Sacramento Area Needle Exchange (SANE), an illegal SEP operating in California, USA. SANE utilises “satellite exchangers” to distribute the bulk of its syringes and HIV risk reduction supplies. Advantages of relying primarily on Designated Exchangers (DE) for delivery of SEP services are that it: (1) allows for coverage of a large geographical area; (2) keeps operational cost low; (3) provides syringes to clients who may not want to or cannot use fixed site programmes; (4) limits the possibility of detection of programme personnel and clients by law enforcement. Limitations are that: (1) it is not as conducive as fixed sites to providing a wide range of ancillary services; (2) it may not be optimal for drug users who do not want to be reliant on other people for access to syringes; (3) those who receive services from a satellite exchanger may not derive as much counselling and referral services as direct exchangers. The lack of legal status, political support and adequate funding threatens the programme’s existence.     

西方公共卫生评估的演化逻辑及其启示

公共卫生评估的历史发展大致经历了四个阶段：基本研究、状态评估、衡量效力以及责任和遵从标准。从公共卫生评估演变的轨迹我们可以得出下列启示：项目循环管理方法倾向、结果和过程评估的增加、强调方法上的精确、越来越多地使用定量的和混合的方法以及对公众的责任。