首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1098篇
  免费   97篇
  国内免费   20篇
耳鼻咽喉   1篇
儿科学   32篇
妇产科学   28篇
基础医学   88篇
口腔科学   3篇
临床医学   120篇
内科学   277篇
皮肤病学   4篇
神经病学   48篇
特种医学   12篇
外科学   70篇
综合类   65篇
预防医学   339篇
眼科学   3篇
药学   47篇
  1篇
中国医学   15篇
肿瘤学   62篇
  2024年   5篇
  2023年   23篇
  2022年   60篇
  2021年   89篇
  2020年   80篇
  2019年   69篇
  2018年   50篇
  2017年   46篇
  2016年   55篇
  2015年   38篇
  2014年   114篇
  2013年   79篇
  2012年   62篇
  2011年   101篇
  2010年   51篇
  2009年   63篇
  2008年   39篇
  2007年   37篇
  2006年   37篇
  2005年   29篇
  2004年   18篇
  2003年   16篇
  2002年   7篇
  2001年   14篇
  2000年   6篇
  1999年   5篇
  1998年   3篇
  1997年   6篇
  1996年   1篇
  1994年   3篇
  1993年   2篇
  1992年   1篇
  1991年   1篇
  1990年   1篇
  1985年   2篇
  1984年   2篇
排序方式: 共有1215条查询结果,搜索用时 15 毫秒
71.
SummaryObjectives To explore the perceptions of health and physical activity, and the associations between these two areas from a theoretical lifestyle perspective.Methods Data was collected by means of a self-administered questionnaire, among 3019 adults attending centres for preventive medicine in France. Correspondence analysis examined the significance of the relationships between perceptions of health and perceptions of sports and physical activity.Results Four pricipal types of subjects emerged from the factor analyses expressing four different lifestyle patterns. Non physically active lifestyle: a feeling of not being healthy, Physically active lifestyle, pleasure/leisure-oriented, Necessarily physically active lifestyle, regardless of health, Physically active lifestyle aimed at stress relief.Conclusions The sociological approach helps tackle sports and physical activity as behaviour patterns but also and especially as a health orientation connected with the socio-economical climate. This approach also gives sports practice back its meaningful cultural dimension.
ZusammenfassungFragestellung Wie werden Gesundheit und körperliche Aktivitäten und Sport wahrgenommen? Welche Zusammenhänge bestehen zwischen den beiden Parametern in Hinblick auf den Lebensstil?Methoden Die Rohdaten wurden mit Hilfe eines selbst zu beantwortenden Fragebogens gesammelt. Die 3019 Studienteilnehmer sind ausschliesslich Erwachsene, die in einem französischen Vorsorgezentrum während einer freiwilligen Beratungsstunde angesprochen wurden. Der Schwerpunkt der anschliessenden Faktorenanalyse lag in der Suche nach Korrelationen zwischen der Wahrnehmung der Gesundheit und den Eindrücken, die die sportlichen Aktivitäten hinterliessen.Ergebnisse Diese Analyse ermöglicht es, vier Antwortprofile herauszuarbeiten, die letztlich vier verschiedenen Lebensstilen entsprechen: inaktiv, allgemeines Unwohlsein, das sich im klinischen Bereich niederschlägt, aktiv, auf Lustempfindungen orientiert, passiv, fatalistisch, ohne Interesse an Gesundheit, aber gesellschaftsorientiert, aktiv, gesundheitsbewusst, auf Stressabbau orientier.Schlussfolgerungen Aus soziologischer Sicht kann somit die Ausübung körperlicher Aktivitäten einerseits als reines Verhaltensmuster gedeutet werden, andererseits aber auch als gesundheitsorientierte Handlung, eng verknüpft mit den sozioökonomischen Verhältnissen. Sprot an sich erhält somit seine Bedeutung als kulturelle Dimension wieder.

RésuméObjectifs Etudier les perceptions de la santé et de l'activité physique et sportive, ainsi que les relations entre les deux dans la perspective théorique du style de vie.Méthodes Des données ont été recueillies par questionnaire auto-administré auprès de 3019 adultes consultant un centre de médecine préventive français. Une analyse factorielle des correspondances a permis d'étudier les relations d'affinités entre les perceptions de la santé et celles de l'activité physique et sportive.Résultats Quatre profils de réponses se distinguent par cette analyse factorielle qui font émerger quatre styles de vie: physiquement inactif, le sentiment de ne pas être en bonne santé, physiquement actif, orienté vers le plaisir et les loisirs, physiquement actif au travail sans attention pour la santé et physiquement actif pour lutter contre le stress.Conclusions L'approche sociologique permet d'aborder la pratique physique et sportive, comme un comportement mais aussi et surtout comme une orientation de santé, en relation avec les conditions socio-économiques. Elle redonne ainsi à la pratique sportive sa dimension culturelle signifiante.
  相似文献   
72.
We report that rats learning a spatial memory task in the Morris water maze show elevated expression of the signal transduction receptor for BDNF and the synaptic associated protein synapsin I in the hippocampus. Nuclease protection assays showed maximal levels of TrkB and synapsin I mRNAs in the hippocampus by the time that asymptotic learning performance had been reached (Day 6). Increases in synapsin I mRNA were matched by changes in synapsin I protein as revealed by western blot analysis. Synapsin I is a downstream effector for the BDNF tyrosine kinase cascade pathway which has important roles in synaptic remodeling and function. Therefore, parallel changes in TrkB and synapsin I mRNAs suggest a role of the BDNF system in synaptic function or adaptation. Levels of TrkB mRNA in the hippocampus were attenuated after learning acquisition (Day 20), but synapsin I mRNA was still elevated, suggesting that the BDNF system may participate in events secondary to learning, such as strengthening of neural circuits. TrkB and synapsin I mRNAs showed an increasing trend in the cerebellum of learning rats and no changes were observed in the caudal cerebral cortex. The selectivity of the changes in trkB and synapsin I, affecting the hippocampus, is in agreement with the role of this structure in processing of spatial information. Behavioral regulation of neurotrophins may provide a molecular basis for the enhanced cognitive function associated with active lifestyles, and guide development of strategies to promote neural healing after CNS injury or disease.  相似文献   
73.
Patient satisfaction after surgical treatment for fistula-in-ano   总被引:7,自引:3,他引:4  
PURPOSE: The surgical treatment of fistula-in-ano frequently results in recurrence of the fistula or postoperative anal incontinence. Despite these problems, most patients are satisfied with the results of their surgery. To clarify this apparent discrepancy, we attempted to identify factors that affect patient's lifestyles and may contribute to their satisfaction. METHODS: A questionnaire was mailed to 624 patients surgically treated for cryptoglandular fistula-in-ano at the University of Minnesota during a five-year period. Three hundred seventy-five patients returned their questionnaires. Patients who were followed up for a minimum of one year were included in this retrospective study. Associations between postoperative complications and patient satisfaction were identified by chi-squared tests and multiple logistic regression. Attributable fractions for patient dissatisfaction were calculated using study population dissatisfaction rates. RESULTS: Patient satisfaction was strongly associated with fistula recurrence, difficulty holding gas, soiling of undergarment, and accidental bowel movements. Effects of incontinence on patient quality of life were also significantly associated with patient satisfaction as was the number of lifestyle activities affected by incontinence. Patients with fistula recurrence reported a higher dissatisfaction rate (61 percent) than did patients with anal incontinence (24 percent), but the attributable fraction of dissatisfaction for incontinence (84 percent) was greater than that for fistula recurrence (33 percent). Patient satisfaction was not significantly associated with age, gender, history of previous fistula surgery, type of fistula, surgical procedure, time since surgery, or operating surgeon. CONCLUSION: Patient satisfaction after surgical treatment for fistula-in-ano is associated with recurrence of the fistula, the development of anal incontinence, and with the effects of anal incontinence on patient lifestyle. In our series of patients treated mainly with laying open of the fistula tract, patients with fistula recurrence had a higher dissatisfaction rate than did patients with anal incontinence. However, because anal incontinence was more prevalent than fistula recurrence, a higher fraction of dissatisfaction was attributable to anal incontinence.Presented at the meeting of the Association of Coloproctology of Great Britain and Ireland, Brighton, United Kingdom, July 10 to 12, 2000.  相似文献   
74.
Objectives. What has become of lifestyle differences in a united Europe, where member states become more and more similar on aspects such as welfare systems and population dynamics? In this paper, we try to answer the question whether the gap in lifestyle-related risk factors in Europe has narrowed over the past 30–40 years.Methods. Smoking, alcohol consumption, physical activity, obesity and food consumption all have an impact on cancer, cardiovascular disease and other non-communicable diseases. Databases of Eurostat, OECD (Organisation for Economic Co-operation and Development) and the World Health Organisation were screened for data on lifestyle-related risk factors in the European Union, and a literature search was performed for studies that collected international comparable data about the selected factors.Results. The gap in European lifestyle has narrowed over the past 30–40 years for smoking (women), alcohol consumption and total fat intake. For fruit and vegetable consumption, convergence is not occurring. For some risk factors, such as smoking and obesity, intranational differences surpass the international differences.Conclusions. The results support the notion of convergent lifestyles among Europeans over time. We also found that there is a serious lack of reliable data on lifestyle-related risk factors that are suitable for international comparison. It is essential to invest in reliable and internationally comparable data, obtained according to best evidence, to get more insight into real differences regarding risk factors in Europe. The European Public Health programme may be an opportunity to realize these goals.  相似文献   
75.
Scientists and policymakers have shown growing interest in the health effects of chronic air pollution exposure. In this study, we use geostatistical techniques in combination with small-area data to address a central research question: "Does chronic exposure to particulate air pollution significantly associate with mortality when the effects of other social, demographic, and lifestyle confounders are taken into account?" Our analysis relies on age-standardized mortality ratios for census tracts (CTs) of Hamilton (average population of 3419 persons), social and demographic data from the 1991 Census of Canada, smoking variables extracted from secondary surveys, and total suspended particulate (TSP) data from 23 monitoring stations operated by the Ministry of the Environment. Air pollution data are interpolated with a geostatistical procedure known as "kriging". This method translates fixed-site pollution monitoring observations into a continuous surface, which was overlaid onto the population-weighted centroids of the CTs. Our results show substantively large and statistically significant health effects for women and men. Evaluated over the inter-quartile range of the data, we found the relative risk of premature mortality for TSP exposure to be 1.19 (95% CI: 1.13-1.26) for women and 1.30 (95% CI: 1.24-1.37) for men. We also tested associations with cardio-respiratory and cancer mortality. We found positive, significant associations between particulate exposure and these causes of death in most models. Inclusion of socioeconomic, demographic, and lifestyle reduced but did not eliminate the health effects of exposure to particulate air pollution. Overall our results suggest that intra-urban variations in particulate air pollution significantly associate with premature, all-cause, cardio-respiratory, and cancer mortality in small areas of Hamilton.  相似文献   
76.
Demographic changes all over the world lead to an increasing proportion of elderly people with far-reaching implications for our societies, but also for the individual. Ageing affects nutrition as well as lifestyle: adequate nutrition becomes increasingly difficult with increasing age, whereas physical activity usually decreases. Nutrition and lifestyle, however, are important determinants of health and outcome in the elderly. Our knowledge about nutrition and lifestyle of elderly people in Europe is fragmentary. The most comprehensive information originates from the longitudinal multi-centre SENECA study that started in 1988–1989 and ended in 1999. In addition, several nationwide surveys and a variety of local studies have been performed. According to these studies, nutritional status, dietary habits and food pattern, energy and nutrient intake vary widely across Europe. Median energy intake for example ranged from 7.6 to 11.8 MJ/day in men and from 6.0 to 10.1 MJ/day in women in the SENECA baseline study. The food pattern in southern countries was characterised by high intakes of grain, vegetables, fruit, lean meat and olive oil, whereas elderly people in northern countries consumed more milk products and more often reported the use of nutrient supplements. In some towns considerable proportions of elderly men and women might be at risk of vitamin or mineral deficiency. Great differences between the countries also exist with respect to physical activity of elderly people. In a recent pan-European survey physical activity was highest in Sweden and Finland, where more than 85 % of elderly subjects spent at least 3.5 h per week in physical activity, and lowest in Portugal with only 25 % of active elderly. In summary, there is great variation in nutrition and lifestyle across European countries and even within countries. Information about the situation in Eastern European countries is on the whole missing—or at least not published. The aim of the current research project Comparative analysis of existing data on nutrition and lifestyle of the ageing population in Europe, especially in the new Baltic, Central and Eastern regions of the Community, funded by the European Commission, is to collect existing data in Europe in this field and review these data critically in a comparative manner.  相似文献   
77.
BACKGROUND: Surgical practice is often perceived by students as a stressful and demanding lifestyle in which personal and family issues take low priority. For students to receive a more balanced view of surgical practice, we instituted a private practice preceptorship during the last week of our junior surgery clerkship in 2001. We hypothesized that a 4-day preceptorship with surgeons in private practice would improve student perception of surgery as a valid career choice without compromising student educational performance. METHODS: From January to December 2002, 107 junior medical students were assigned to a brief preceptorship with volunteer private practice surgeons during the surgery clerkship (group 1), while 28 students did not participate in the preceptorship (group 2). We assessed student satisfaction via questionnaire and compared student grade performance between groups. RESULTS: One hundred two questionnaires (95%) were returned. Overall, the preceptor experience was rated positively (9.0+/-0.1) based on a 10-point Likert scale. All students commented on the educational or enjoyment value of the preceptorship, with 44% specifically stating that the lifestyle in private surgical practice appeared pleasant. Interestingly, 9% of students volunteered that the experience had swayed them to consider surgery as a career. Twenty-four percent of questionnaires contained negative comments, mainly concerning not enough "hands-on" participation. Grades for the clerkship did not decrease in group 1 when compared with group 2 or with historic controls (n=113). CONCLUSIONS: A 4-day private practice preceptorship at the end of the junior surgery clerkship favorably alters student perceptions of a surgical career without diminishing student grade performance.  相似文献   
78.
Lifespan is a complex phenotype determined by the interaction of genetic and environmental factors. This makes the identification of variants in genes that influence longevity challenging. We believe that the Old Order Amish (OOA) of Lancaster, Pennsylvania is an excellent population for studying the genetics of longevity. They are a closed population derived from a limited number of founders. They have large families and maintain extensive genealogic records dating to the 1700 s. They eschew modern technology; their lifestyle is little changed over the last 250 years. Homogeneity of environment and lifestyle factors across time and across the OOA population minimizes the influence that environmental factors have in determining the differences in lifespan between individuals. We hypothesize that this reduction in environmental variability will make it easier to identify the genetic factors that influence lifespan. In this article, we describe our strategy for identifying variants in genes that influence longevity in the Amish and present the results of our studies to date.  相似文献   
79.
PURPOSE: To present the development and feasibility testing of a sociocultural environmental change intervention strategy aimed at integrating physical activity into workplace routine. DESIGN: Randomized, controlled, post-test only, intervention trial. Setting. Los Angeles County Department of Health Services' worksites. PARTICIPANTS: Four hundred forty-nine employees, predominantly sedentary, overweight, middle-aged women of color, distributed across 26 meetings. INTERVENTION: A single 10-min exercise break during work time involving moderate intensity, low-impact aerobic dance and calisthenic movements to music. MEASURES: Primary-level of participation, particularly among sedentary staff; secondary-self-perceived health status, satisfaction with current fitness level, and mood/affective state. RESULTS: More than 90% of meeting attendees participated in the exercises. Among completely sedentary individuals, intervention participants' self-perceived health status ratings were significantly lower than controls' (OR = 0.17; 95% CI = 0.05, 0.60; P = 0.0003). Among all respondents not regularly physically active, intervention participants' levels of satisfaction with fitness were more highly correlated with self-ranked physical activity stage of change (r = 0.588) than the control participants' (r = 0.376, z = -2.32, p = 0.02). Among the completely sedentary, control participants reported significantly higher levels of energy than did intervention participants (P < 0.01). CONCLUSIONS: Captive audiences may be engaged in brief bouts of exercise as a part of the workday, regardless of physical activity level or stage of change. This experience may also appropriately erode sedentary individuals' self-perception of good health and fitness, providing motivation for adoption of more active lifestyles.  相似文献   
80.
Medical professionals often face many competing demands to contribute both to the clinical care of patients and to the public health of society. We studied the long-term survival of doctors graduating from one medical school over one century (n=1521), comparing those who were presidents of their class to those who appeared alphabetically before or alphabetically after the president in the graduating class photograph. Statistics on long-term mortality were obtained from licensing authorities, medical obituaries, professional associations, alumni records, and national physician directories (follow-up 94% complete, median follow-up duration=38 years, total deaths=220). We found that most graduates were male (88%), white (93%), and younger than 30 years at time of graduation (93%). Presidents more frequently made contributions to society than their classmates, as recognized by professional alumni notices (21.9% vs. 13.3%, P<0.001) and Who's Who directory listings (7% vs. 0.5%, P<0.001). Nonetheless, survival after medical school was 2.4 years shorter for presidents than their classmates (49.0 vs. 51.4, P=0.036). The decrease in life-expectancy was unrelated to medical school marks or early career mortality and was accentuated after adjustments for birth year, gender, race, and specialization (P=0.001). We suggest that the type of medical professional who sacrifices themselves for this type of professional prestige may also be the type who fails to look after their health or is otherwise prone to early mortality.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号