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Hemodialysis represents a chronic stress status for its recipients. Many hypotheses state that this may be associated with oxidative stress. Thus, there may be deficiency of antioxidants like erythrocytic superoxide dismutase, catalase, vitamin E or increased generation of free radicals like superoxide anions. A study was carried out to investigate oxidant and antioxidant status in chronic renal failure patients undergoing hemodialysis and effect of vitamin E supplementation on these two status. Blood samples were collected from patients before and after hemodialysis and from controls. The samples were analyzed for quantitation of MDA as index of lipid peroxide, nitric oxide, vitamin E, vitamin C and enzymatic antioxidants namely erythrocyte SOD and catalase. As compared to controls, the levels of serum MDA were significantly increased and activities of erythrocyte SOD and catalase, levels of serum nitric oxide, serum vitamin E and plasma vitamin C were significantly decreased both before and after hemodialysis. The efficiency of vitamin E therapy in hemodialysis patients was assessed by re-evaluating oxidant and antioxidant status of same patients after supplementation of vitamin E. Vitamin E supplementation caused decrease in serum MDA and increase in levels of serum nitric oxide, vitamin E, vitamin C and activities of erythrocytic SOD and catalase. Our results suggest the presence of oxidative stress and the possible preventive role of vitamin E therapy in hemodialysis patients.  相似文献   
994.
This paper provides a review of the rhetoric behind the component movement in educational software, and a critical analysis and synthesis of issues underlying the movement. We draw on case studies of several significant recent component projects in order to assess claims and to uncover and examine issues that are less often considered. While our empirical base cannot definitively answer all the questions raised, we hope to bring some clarity and some empirically based judgments to bear on how a promising technological innovation can best serve educational ends. Our study led to a focus on three critical issues: (1) the nature of the environment in which components are configured and used; (2) the extent of modifiability that is necessary for effective re-use of components; (3) how the work of designing components and component configurations is distributed among people with different competencies.  相似文献   
995.
The labour market rewards for a number of required human capital competences are analysed using a sample of young European higher education graduates. Factor analysis is applied to classify competences by jobs into eight orthogonal groups, namely participative, methodological, specialised, organisational, applying rules, physical, generic and socio-emotional competences. Estimates for the total rewards for competences are obtained through conventional wage regression, whereas estimates of the total rewards are derived in terms of job satisfaction through ordered logit regression. Explanatory variables include personal characteristics, job attributes, occupational titles, fields of study, type of higher education institution and country dummies. Results on wage rewards show that jobs with higher requirements of participativeand methodological competencesare best paid; conversely, jobs with higher requirements of organisational, applying-rulesand physical competencesare worse paid. Results on total rewards suggest that jobs with higher requirements of competences increase graduates' satisfaction, the only exception being applying-rules competences.  相似文献   
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The present study investigates and compares the influence of teaching Realistic Mathematics on the development of mathematical competence in kindergarten. The sample consisted of 231 Greek kindergarten students. For the implementation of the survey, we conducted an intervention, which included one experimental and one control group. Children in the experimental group were taught Realistic Mathematics according to the principles of Realistic Mathematics Education. The control group was taught mathematics following the basic pedagogical principles of curriculum for kindergarten students. In order to evaluate the mathematical performance of children we used the Test of Early Mathematics Ability (TEMA-3). The results showed that the teaching technique with the use of Realistic Mathematic Education contributed significantly to the development of mathematical competence of young children. Moreover, factors such as gender, age and nonverbal cognitive ability, did not seem to differentiate the development of mathematical competence of children.  相似文献   
999.
In education, case studies have been employed as a major pedagogical means to engage students with realistic materials and practical problems. The usefulness and success of case studies have been documented in literature. In this paper, we move the case study and its technical affordance a step further toward more authentic or realistic learning and toward communities of practice. Drawing on current intellectual achievement in education, developmental psychology and computer-supported collaborative learning, this paper proposes four requirements for interactive case study libraries, focusing on authentic learning, social interaction, resource accumulation, and communities of practice. With a usability engineering case study library as an example, we discuss design concerns derived from these requirements as well as its use in practice.  相似文献   
1000.
We use nationally representative survey data from three cohorts of bachelor’s degree recipients to examine military veterans’ student loan debt at graduation and their employment and earnings 1, 4, and 10 years after graduation, relative to observably similar graduates. We also examine whether the effects of veteran status depend on college sector. Using propensity score weights with covariate adjustment, we find employment and earnings premiums for veterans 1 and 4 years after graduation, and an employment penalty but earnings premium (conditional on employment) 10 years after graduation. We find no clear evidence of a for-profit employment or earnings penalty among bachelor’s degree recipients, including veterans. We do find that veterans are as likely as similar non-veterans to graduate with debt, and that graduating from a for-profit institution yields markedly higher debt amounts, especially for veterans, despite the availability of Montgomery GI Bill benefits for these cohorts.  相似文献   
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