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1.
The oxidation of sheep hemoglobin, in both the oxygenated and deoxygenated forms, by cuprous ions have been studied by spectrophotometric and stopped-flow techniques. Mixing of both the oxy and deoxy forms with excess Cu2+ leads to the rapid oxidation of the iron atoms of all four of the hem groups of the tetrameric protein, followed by the slow formation of hemichromes (low spin FeIII forms of hemoglobin). Stopped-flow studies show that the oxidations follow simple monophasic kinetics with second-order rate constants of 65 and 310 M?1 sec?1 for the oxy and deoxy forms, respectively. Variable temperature studies yield Arrhenius activation energies of 43 for the oxy form and 113 kJ mole?1 for the deoxy form. For each form of the protein the activation energy is very similar to the activation enthalpy. While the deoxy form is characterized by an activation energy and enthalpy that is more than twice the corresponding value in the oxy form. The activation entropies show highly significant differences being ?128 e.u. and 136 e.u. at 25°C for the oxy and deoxy forms, respectively.  相似文献   
2.
No less than 52 species of barbets have been imported and kept in German zoos during the period between 1960 and 2000. In the first years some (world) first breeding records came from several zoos, Frankfurt with six world first records as the most successful one. Today only two species, the Bearded Barbet (Lybius dubius) and the Red-and-yellow Barbet (Trachyphonus erythrocephalus), breed regularly in ten respectively 14 German zoos and bird parks. The majority of the other species have been lost since, e.g. for future breeding projects. There are also some records of successful broods of barbets in private facilities, but the two species mentioned above are also on top of the list of the breeding records. The problems of keeping and breeding barbets in captivity, their life span, diseases and adequate housing conditions are compiled from data of the literature.  相似文献   
3.
目的 对公立医院卫生人才流失现状进行实证研究,分析其原因并提出相应对策。方法 采用分层抽样方法对潍坊市29家公立医院卫生人才进行问卷调查。结果 公立医院卫生人才流失现象较为普遍,流失率为30.9%,流失原因多为个人发展、薪酬、执业环境。结论 应采取相应对策提高公立医院卫生人才的稳定性,完善相应的管理机制,规范人才的合理流动。  相似文献   
4.
探讨了开展公立医院战略绩效管理的必要性,剖析了当前公立医院绩效管理的弊端及实质,结合对战略绩效管理理论和医院战略绩效内涵特征的分析,提出了集本质特征、功能定位和未来发展于一体的,包含了2个层面、4个模块和7个循环子系统的公立医院战略绩效管理体系概念框架。  相似文献   
5.
目的 了解京郊乡镇卫生院卫生服务可及性现状,分析基层卫生人力资源对服务可及性的影响,并提出相应的建议。方法 采用分层抽样与目的抽样结合的方法,对北京市5个远郊区县15个乡镇的21名医务人员以及11名患者进行关键知情人访谈。结果 乡镇卫生院人员队伍不稳定、专业人员缺乏、人员编制有限以及梯队不合理对卫生服务可及性产生直接的影响。结论 从满足人员基本需求、配备专业技术人员、科学制定人员编制以及合理配置人员梯队四方面改善基层卫生人才队伍建设,从而提高卫生服务可及性。  相似文献   
6.
Many marine protected areas (MPAs), particularly in developing countries, have failed because of a lack of enforcement and monitoring due to limited public funds for conservation. Private investment and management in MPAs offers a potential solution, and has been applied with initial positive results at the Sugud Islands Marine Conservation Area (SIMCA) in Sabah, Malaysia. Conservation fees charged to visitors to Lankayan Island Dive Resort within the SIMCA have generated a sustainable source of financing to meet the majority of management costs for the conservation area, which is separately managed by a private organization called Reef Guardian. The availability of adequate funds has enabled Reef Guardian to invest in personnel training and surveillance technology to enforce the rules and regulations of the conservation area. In collaboration with government enforcement agencies, Reef Guardian has reduced threats such as illegal fishing and turtle egg poaching. As a result, there is a comparatively high abundance of commercially important fish, and turtle nestings at Lankayan Island have increased. Private management can be effective in conserving biodiversity in MPAs, and may well succeed regionally in suitable locations.
Lydia C. L. TehEmail:
  相似文献   
7.
Rapid urbanization has exerted substantial pressure on China’s energy system and contributed to climate change. To find the key drivers of urban residential energy consumption and CO2 emissions, this paper uses an extended Stochastic Impacts by Regression on Population, Affluence and Technology (STIRPAT) model that employs city-level data to examine the influences of population scale, income level, population compactness and price on house-based residential energy consumption, energy-related CO2 emissions and private vehicle ownership. The empirical results indicate that factors such as population scale, affluence, and population compactness can lead to increases in residential energy consumption and CO2 emissions. In terms of transportation, income and population scale positively drive the growth of private vehicle ownership, while the fuel price negatively influences private vehicle ownership. Moreover, population scale is the most important factor in residential energy consumption and CO2 emissions. Finally, policy recommendations are suggested for China’s urban development strategy and urban design and to encourage technology innovations that reduce residential energy consumption and CO2 emissions.  相似文献   
8.
Previous research has shown that bicyclic 6:5-fused heteroaromatic compounds with two N-atoms have variable degrees of adenosine A1 receptor antagonistic activity. Prompted by this imidazo[1,2-α]pyridine analogues were synthesized and evaluated for their adenosine A1 and A2A receptor affinity via radioligand binding studies and subjected to a GTP shift assay to determine its adenosine A1 receptor agonistic or antagonistic functionality. Imidazo[1,2-α]pyridine, the parent scaffold, was found devoid of affinity for the adenosine A1 and A2A receptors. The influence of substitution on position C2 showed no improvement for either adenosine A1 or A2A receptor affinity. The addition of an amino or a cyclohexylamino group to position C3 also showed no improvement of adenosine A1 or A2A receptor affinity. Surprisingly para-substitution on the phenyl ring at position C2 in combination with a cyclohexylamino group at position C3 led to adenosine A1 receptor affinity in the low micromolar range with compound 4d showing: (1) the highest affinity for the adenosine A1 receptor with a Ki value of 2.06 µM and (2) adenosine A1 receptor antagonistic properties. This pilot study concludes that para-substituted 3-cyclohexylamino-2-phenyl-imidazo[1,2-α]pyridine analogues represent an interesting scaffold to investigate further structure-activity relationships in the design of novel imidazo[1,2-α]pyridine-based adenosine A1 receptor antagonists for the treatment of neurodegenerative disorders.  相似文献   
9.
Private microsatellite alleles tend to be found in the tails rather than in the interior of the allele size distribution. To explain this phenomenon, we have investigated the size distribution of private alleles in a coalescent model of two populations, assuming the symmetric stepwise mutation model as the mode of microsatellite mutation. For the case in which four alleles are sampled, two from each population, we condition on the configuration in which three distinct allele sizes are present, one of which is common to both populations, one of which is private to one population, and the third of which is private to the other population. Conditional on this configuration, we calculate the probability that the two private alleles occupy the two tails of the size distribution. This probability, which increases as a function of mutation rate and divergence time between the two populations, is seen to be greater than the value that would be predicted if there was no relationship between privacy and location in the allele size distribution. In accordance with the prediction of the model, we find that in pairs of human populations, the frequency with which private microsatellite alleles occur in the tails of the allele size distribution increases as a function of genetic differentiation between populations.  相似文献   
10.
改良早期预警评分对转院转运工作影响的临床研究   总被引:1,自引:0,他引:1  
朱远群  杜凌  陈文震  吴华容 《蛇志》2011,23(2):126-128
目的 研究改良早期预警(MEWS)评分对转院转运工作的影响.方法 在转院转运工作中应用MEWS评分系统对患者进行病情评估,对比其应用前(对照组)、应用后(研究组)转院患者转运途中病情恶化的发生率、患者或家属满意度及医生、护士对实施MEWS评分转运管理模式前(对照组)、后(研究组)满意度的变化.结果 转院患者转运途中病情恶化发生率由应用前(对照组)的10.63%降至应用后(研究组)的3.74%,应用前、后比较差异有显著统计学意义(P<0.01);患方满意度则由96%提高至99%,医护人员对实施MEWS评分转运管理模式前、后的满意度由应用前的83.3%提高至应用后的95%,应用前、后比较均有显著性意义(P<0.05).结论 MEWS评分能对转院患者的病情进行比较客观、准确的评估,提高了医务人员的质量和医疗干预意识,从而有效降低转院患者转运途中的病情恶化发生率和提高院前医患双方的满意度,是转院转运工作中简便、快捷、客观、实用的病情评估方法和模式,值得推广应用.  相似文献   
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