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   835篇
  免费   61篇
  国内免费   2篇
耳鼻咽喉   5篇
儿科学   58篇
妇产科学   7篇
基础医学   90篇
口腔科学   12篇
临床医学   110篇
内科学   222篇
皮肤病学   23篇
神经病学   18篇
特种医学   142篇
外科学   54篇
综合类   23篇
预防医学   64篇
眼科学   8篇
药学   39篇
肿瘤学   23篇
  2022年   4篇
  2021年   11篇
  2020年   2篇
  2019年   4篇
  2018年   13篇
  2017年   3篇
  2016年   8篇
  2015年   12篇
  2014年   13篇
  2013年   20篇
  2012年   20篇
  2011年   21篇
  2010年   29篇
  2009年   26篇
  2008年   24篇
  2007年   24篇
  2006年   20篇
  2005年   19篇
  2004年   24篇
  2003年   19篇
  2002年   20篇
  2001年   15篇
  2000年   17篇
  1999年   15篇
  1998年   42篇
  1997年   46篇
  1996年   49篇
  1995年   36篇
  1994年   23篇
  1993年   24篇
  1992年   9篇
  1991年   24篇
  1990年   14篇
  1989年   26篇
  1988年   33篇
  1987年   27篇
  1986年   32篇
  1985年   22篇
  1984年   11篇
  1983年   13篇
  1982年   6篇
  1981年   17篇
  1980年   7篇
  1979年   8篇
  1978年   8篇
  1977年   9篇
  1976年   7篇
  1975年   9篇
  1974年   4篇
  1972年   2篇
排序方式: 共有898条查询结果,搜索用时 15 毫秒
101.
PURPOSE: his study evaluated several factors that were thought to contribute to African American women's disproportionate incidence and sequelae of diabetes. METHODS: African American women (1055) living in San Diego County completed surveys about diabetes-related beliefs, screening behaviors, knowledge, and attitudes. Participants' ages ranged from 20 to 94 years, and 33.7% of the women reported completing college. RESULTS: Most of the women (59%) perceived diabetes to be a serious health threat to African American women. Thirty-two percent of the total sample and 37% of the high-risk group reported having been screened for diabetes within the past year. Nearly 37% reported never having been screened for diabetes, and 31% of those at above-average risk of developing diabetes could not recall ever having been screened. Women had a limited knowledge of the symptoms of diabetes, ways to decrease the risk factors and the sequelae of diabetes. Higher-risk women showed greater diabetes knowledge. CONCLUSIONS: Most participants reported that diabetes was a significant threat to their health but lacked sufficient knowledge to protect themselves from the disease. A focused, aggressive education campaign could yield better health outcomes.  相似文献   
102.
PURPOSE: The purpose of this study was to assess the diabetes risk status, incidence, and morbidity within San Diego's Chamorro community as a foundation to help community leaders and health care providers create culturally customized health promotion interventions. METHODS: The Behavioral Risk Factor Surveillance Survey was used to query a randomly selected, convenience sample of San Diego Chamorros (N = 228) drawn from the Chamorro Directory International. Based on individual survey responses, participants were mailed personalized health-promoting information. Subsequently, they received information that addressed the most commonly observed overall threats to the Chamorro community's health. RESULTS: A higher than average prevalence of diabetes and gestational diabetes was reported by study participants along with a high prevalence of the risk factors associated with the premature onset of diabetes and its consequences. CONCLUSION: Collaborative partnerships between health professionals and community leaders can help identify opportunities and strategies for improving the health of the nation's population subgroups. San Diego's Chamorro community leaders now have a clearer understanding of the prevalence of diabetes risk factors within their community and can begin working with public health educators to create culturally aligned diabetes prevention and management programs. Given the willingness of Chamorro leaders to get involved in the development of a diabetes awareness campaign and the community's closely knit social network, it should be possible to promote (1) community participation in the intervention program, (2) an increase in the community's adherence to recommended behavioral changes, and (3) identification of additional program modifications that will further enhance the program's cultural relevance.  相似文献   
103.
104.
Existing studies suggest that exercise-induced ischemia produces an increase in left ventricular end-diastolic volume; however, all of these studies have included patients with previous myocardial infarction. To test whether the end-diastolic volume response to exercise is related to the extent of myocardial scar, the results of gated radionuclide supine exercise tests performed on 130 subjects were reviewed. The patient group comprised 130 subjects were reviewed. The patient group comprised 130 men aged 35 to 65 years (mean +/- SD 52 +/- 5) with documented coronary heart disease. The extent of myocardial ischemia and scar formation was assessed by stress electrocardiography and thallium-201 scintigraphy. Patients were classified into three groups on the basis of left ventricular end-diastolic volume response at peak exercise: group 1 (n = 72) had an increase of end-diastolic volume greater than 10%, group 2 (n = 41) had a change in end-diastolic volume less than 10% and group 3 (n = 17) had a decrease in end-diastolic volume greater than 10% (n = 17). At rest there was no significant difference among groups in heart rate, systolic blood pressure, end-diastolic (EDVrest) or end-systolic volumes or ejection fraction (p greater than 0.05); however, at peak exercise the end-systolic volume response was significantly greater for group 1 (p less than 0.002).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
105.
The bacterial pathogen Vibrio parahaemolyticus utilizes a type III secretion system to cause death of host cells within hours of infection. We report that cell death is completely independent of apoptosis and occurs by a mechanism in which injection of multiple type III effectors causes induction of autophagy, cell rounding, and the subsequent release of cellular contents. Autophagy is detected by the appearance of lipidated light chain 3 (LC3) and by increases in punctae and vacuole formation. Electron microscopy reveals the production of early autophagic vesicles during infection. Consistent with phosphoinositide 3 (PI3) kinase playing a role in autophagy, treatment of infected cells with a PI3 kinase inhibitor attenuates autophagy in infected cells. Because many effectors are injected during a V. parahaemolyticus infection, it is not surprising that the presence of a sole PI3 kinase inhibitor does not prevent inevitable host-cell death. Our studies reveal an infection paradigm whereby an extracellular pathogen uses its type III secretion system to cause at least three parallel events that eventually result in the proinflammatory death of an infected host cell.  相似文献   
106.
We compared the prognostic significance of variables from a symptom-limited bicycle exercise test performed three weeks after acute myocardial infarction with clinical variables from the hospitalization utilizing discriminant function analysis for one year follow-up. Clinical exclusion criteria define a high-risk group of patients not eligible for exercise testing. Among 430 patients without test 28.4% died versus 6.6% among 456 patients with test (P less than 0.0001) and 21.4% versus 9.6% experienced a new infarction (P less than 0.001). The most important exercise test variables were duration of exercise and ventricular premature beats. The prediction of death was not significantly different when clinical variables, exercise test variables or the combined set were used for positive predictive value (66.7%, 60.0%, 63.3%) and negative predictive value (71.6%, 67.4%, 71.8%). For new infarction the positive predictive value was significantly higher for exercise test variables (56.8%, P less than 0.03) or the combined set (59.3%, P less than 0.02) compared to clinical variables (45.5%). The negative predictive value was significantly higher for clinical variables (79.6%) compared to exercise data (63.6%, P less than 0.0001) or the combined set (67.0%, P less than 0.001). We conclude that exercise data cannot improve prediction of death but provides higher positive predictive value for the prediction of new infarction.  相似文献   
107.
Using a recently developed hepsulfam-induced pancytopenia model in rhesus macaques, we have studied the effects of recombinant human interleukin-6 (rhIL-6) and rhIL-3 on marrow regeneration. Control animals were given hepsulfam (1.5 g/m2 by a single 30-minute intravenous [i.v.] injection, n = 4), while study animals received hepsulfam followed by rhIL-6, rhIL-3, or a combination of rhIL-6 and rhIL-3 (n = 3 per study group). Each cytokine was administered by once- daily subcutaneous (SC) injection (15 micrograms/kg/d) for 3 weeks beginning the day after chemotherapy (days 2 through 22). Mean platelet counts in control animals were < 100,000/microL on days 15 through 24, with 50% of the counts < 50,000/microL and two of four animals requiring platelet transfusion. In the rhIL-6- and rhIL-6/rhIL-3- treated groups, the nadir mean platelet counts were 164,000 +/- 58,700/microL and 162,300 +/- 23,800/microL, respectively, and occurred on day 15. Platelet counts in the rhIL-3-treated group were similar to those in controls. Mean absolute neutrophil counts (ANCs) < 1,000/microL occurred on days 10 through 29 in control animals, days 8 through 15 in rhIL-6-treated animals, and days 6 through 8 and 13 in rhIL-6/rhIL-3-treated animals. The frequency of ANCs < 500/microL was significantly less in the rhIL-6- and rhIL-6/rhIL-3-treated groups versus control groups (2.7 +/- 0.6 and 2.0 +/- 1.0 vs 7.0 +/- 1.4 occurrences, respectively; P < .05). rhIL-3-treated animals had ANCs similar to those in controls; one animal died with septicemia on day 21. Monkeys receiving rhIL-6 were significantly more anemic during the cytokine administration period; however, the anemia resolved by day 24. Coadministration of rhIL-3 and rhIL-6 partially corrected the anemia. The data indicate that rhIL-6 prevents significant thrombocytopenia and shortens the neutropenic period in this chemotherapy model.  相似文献   
108.
109.
110.
This study assessed photophobia in patients with benign essential blepharospasm (BEB), and determined the impact of blepharospasm on activities of daily living. Utilizing a patient–researcher collaborative approach, this study was conducted in partnership with the Benign Essential Blepharospasm Research Foundation. Of 316 respondents, 94% reported light sensitivity and 25% reported severe activity limitations. Photophobia appears to be more prominent in BEB than previously thought. Light exacerbates and triggers symptoms that compromise quality of life by affecting daily activities. Collaboration with self-advocates can be an effective way to conduct questionnaire-based research. The authors recommend development of other studies that use this type of partnership.  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