全文获取类型
收费全文 | 1656720篇 |
免费 | 153238篇 |
国内免费 | 3688篇 |
专业分类
耳鼻咽喉 | 21980篇 |
儿科学 | 55427篇 |
妇产科学 | 45477篇 |
基础医学 | 238752篇 |
口腔科学 | 46114篇 |
临床医学 | 150819篇 |
内科学 | 341705篇 |
皮肤病学 | 43479篇 |
神经病学 | 143672篇 |
特种医学 | 60845篇 |
外国民族医学 | 553篇 |
外科学 | 244667篇 |
综合类 | 33542篇 |
现状与发展 | 3篇 |
一般理论 | 559篇 |
预防医学 | 131000篇 |
眼科学 | 36212篇 |
药学 | 116379篇 |
1篇 | |
中国医学 | 4852篇 |
肿瘤学 | 97608篇 |
出版年
2021年 | 14837篇 |
2020年 | 12962篇 |
2019年 | 24416篇 |
2018年 | 29976篇 |
2017年 | 25170篇 |
2016年 | 27405篇 |
2015年 | 29464篇 |
2014年 | 36127篇 |
2013年 | 50213篇 |
2012年 | 61542篇 |
2011年 | 63889篇 |
2010年 | 41577篇 |
2009年 | 36001篇 |
2008年 | 57162篇 |
2007年 | 59571篇 |
2006年 | 59174篇 |
2005年 | 57341篇 |
2004年 | 54623篇 |
2003年 | 51706篇 |
2002年 | 49687篇 |
2001年 | 77392篇 |
2000年 | 79053篇 |
1999年 | 65279篇 |
1998年 | 17679篇 |
1997年 | 15990篇 |
1996年 | 16141篇 |
1995年 | 15289篇 |
1994年 | 13825篇 |
1993年 | 12969篇 |
1992年 | 48001篇 |
1991年 | 45406篇 |
1990年 | 43359篇 |
1989年 | 41274篇 |
1988年 | 37879篇 |
1987年 | 36917篇 |
1986年 | 34400篇 |
1985年 | 32659篇 |
1984年 | 24864篇 |
1983年 | 20927篇 |
1982年 | 12731篇 |
1979年 | 21618篇 |
1978年 | 15244篇 |
1977年 | 12728篇 |
1976年 | 11873篇 |
1975年 | 12264篇 |
1974年 | 14789篇 |
1973年 | 14352篇 |
1972年 | 13382篇 |
1971年 | 12191篇 |
1970年 | 11596篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Four clinical trials of porcine islet transplantation have been reported, and there are verbal reports that clinical trials on much larger scales are continuing in centers in China and Russia. The four reported trials are briefly reviewed and, in the light of the present status of experimental islet xenotransplantation, consideration is given to whether such trials are currently justified. The Ethics Committee of the International Xenotransplantation Association has (1) emphasized the need for encouraging studies in non-human primates before clinical trials should be undertaken, (2) mandatory monitoring for the transfer of porcine microorganisms, and (3) careful regulation and oversight by recognized bodies. Other aspects of the topic, such as the need for informed consent, are briefly discussed. We conclude that, at the present time, more data documenting convincing efficacy, focused on clinically applicable immunosuppressive regimens, are needed to justify the initiation of closely monitored clinical trials. A clinical trial may then be justified even though the potential risk to the patients, and possibly for society, will not be zero. 相似文献
82.
Marcondes C Fran?a Maria E Calcagnotto Jaderson C da Costa Iscia Lopes-Cendes 《Movement disorders》2006,21(7):1051-1053
Spinocerebellar ataxia (SCA) types 2 and 3 are autosomal-dominant neurodegenerative disorders caused by mutations in two different genes. We identified mutations for SCA2 and SCA3 segregating simultaneously in a single Brazilian family. The index patient had SCA2, whereas her two second-degree cousins had SCA3. Disease was more rapidly progressive in the SCA2 patient, who presented severe brainstem and pancerebellar atrophy, as opposed to the two SCA3 patients, who had only mild cerebellar vermian atrophy. In such situations, molecular confirmation of all patients may avoid misdiagnosis of SCA subtypes and eventual errors in predictive testing of unaffected family members. 相似文献
83.
84.
85.
86.
Timothy C. Evans MD PhD ; Keren H. Wick PhD ; Douglas M. Brock PhD ; Douglas C. Schaad PhD ; Ruth Ballweg MPA PA-C 《The Journal of rural health》2006,22(3):212-219
CONTEXT: The physician assistant profession has been moving toward requiring master's degrees for new practitioners, but some argue this could change the face of the discipline. PURPOSE: To see if there is an association between physician assistants' academic degrees and practice in primary care, in rural areas, and with the medically underserved. METHODS: Surveys were sent to 880 graduates of the first 32 University of Washington physician assistant classes through 2000. Respondents noted their academic degree at program entry and the highest degree attained at any time up to the time of survey. Relationships between practice characteristics and academic degree levels were tested by unadjusted odds ratios and logistic regression after controlling for year of graduation and sex. RESULTS: Of the 478 respondents, 54% worked in primary care, about 30% practiced in nonmetropolitan communities, and 42% reported providing care for the medically underserved. Respondents with no degree (33% of total at entry, 24% at survey) were significantly more likely than degree holders to work in primary care and nonmetropolitan areas. Respondents with no degree at program entry were significantly more likely, and those with no degree at the time of the survey were marginally more likely, to self-report work with the medically underserved. CONCLUSION: Respondents with no academic degree are significantly more likely to demonstrate a commitment to primary, rural, and underserved health care. These findings may inform the national debate about the impact of required advanced degrees on the practice patterns of nonphysician providers. 相似文献
87.
88.
AIMS: To establish all-cause and cause-specific death rates, and risk factors for mortality in insulin-treated diabetic individuals living in the province of Canterbury, New Zealand. METHODS: Insulin-treated diabetic subjects (n = 995) on the Canterbury Diabetes Registry were followed up over 15 years and vital status determined. Death rates were standardized and hazard regression was used to model the effects of demographic covariates on relative survival time. RESULTS: There were 419 deaths in 11 226.3 person-years of follow-up with a standardized mortality ratio (SMR) of 2.0 (95% confidence interval (CI) 1.8-2.2). Relative mortality was greatest for the group aged 0-29 years (SMR 3.0 (95% CI 2.4-3.7)). After controlling for diabetes duration and gender, a 10-year increment in age of onset was associated with a 33% decrease in relative hazard (95% CI 29-36%), indicating that excess mortality due to diabetes declines with rising age of onset. After controlling for age of onset and gender, each 10-year increment in duration of diabetes is associated with a 26% decrease in relative hazard (95% CI 24-29%), indicating that with longer survival the mortality hazard approaches the general population hazard. Relative mortalities were increased for cardiovascular, renal and respiratory disease, but not malignancy. Relative mortality from acute metabolic complications was increased in the subgroup with age of onset of diabetes < 30 years and requiring insulin within 1 year of diagnosis. CONCLUSIONS: Mortality rates are high for insulin-treated diabetic individuals relative to the general population. 相似文献
89.
Social phobia, fear of negative evaluation and harm avoidance. 总被引:1,自引:0,他引:1
M Faytout J Tignol J Swendsen D Grabot B Aouizerate J P Lépine 《European psychiatry》2007,22(2):75-79
This naturalistic, prospective investigation examined the role of fear of negative evaluation and the personality trait of harm avoidance in the anxiety levels of treated social phobia patients. One hundred and fifty-seven patients with DSM-IV social phobia were assessed before starting treatment and were then followed for up to two years. As expected, greater fear of negative evaluation and higher scores of harm avoidance were associated with greater anxiety at the 6 month follow-up, and harm avoidance remained a significant predictor at 24 months. However, no evidence was found for an interaction between the personality and cognitive variables examined. The findings are discussed in terms of the relative independence of these factors, as well as their potential implications for the treatment of this disorder. 相似文献
90.
S Chinn S H Downs J M Anto M W Gerbase B Leynaert R de Marco C Janson D Jarvis N Künzli J Sunyer C Svanes E Zemp U Ackermann-Liebrich P Burney 《The European respiratory journal》2006,28(4):763-771
The incidence of asthma has been reported to be associated with obesity. An alternative analysis, of net change in prevalence, does not require exclusion of those with asthma at baseline. Follow-up data were obtained from 9,552 participants in the European Community Respiratory Health Survey and the Swiss cohort Study on Air Pollution and Lung Disease in Adults. Incidence of asthma was analysed by proportional hazards regression, and net changes in symptoms and asthma status by generalised estimating equations, by obesity group. Incidence and net change in ever having had asthma were greater in females than in males, and in participants who remained obese compared with those who were never obese (hazard ratio 2.00, 95% confidence interval 1.25-3.20; excess net change 2.8%, 0.4-5.3% per 10 yrs). The effect of being obese on net change in diagnosed asthma was greater in females than in males, but for net change in wheeze without a cold it was greater in males. The present results are consistent with asthma being more frequently diagnosed in females, especially obese females. These findings may help to explain the reports of a stronger association between asthma and obesity in females than in males. 相似文献