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   4783篇
  免费   438篇
  国内免费   1篇
耳鼻咽喉   139篇
儿科学   121篇
妇产科学   141篇
基础医学   681篇
口腔科学   100篇
临床医学   557篇
内科学   811篇
皮肤病学   42篇
神经病学   347篇
特种医学   295篇
外国民族医学   5篇
外科学   673篇
综合类   114篇
一般理论   3篇
预防医学   480篇
眼科学   130篇
药学   352篇
中国医学   3篇
肿瘤学   228篇
  2023年   50篇
  2022年   40篇
  2021年   81篇
  2020年   74篇
  2019年   102篇
  2018年   116篇
  2017年   82篇
  2016年   90篇
  2015年   94篇
  2014年   124篇
  2013年   194篇
  2012年   279篇
  2011年   271篇
  2010年   126篇
  2009年   127篇
  2008年   224篇
  2007年   187篇
  2006年   202篇
  2005年   219篇
  2004年   213篇
  2003年   179篇
  2002年   194篇
  2001年   113篇
  2000年   127篇
  1999年   99篇
  1998年   48篇
  1997年   40篇
  1996年   49篇
  1995年   52篇
  1994年   42篇
  1993年   46篇
  1992年   131篇
  1991年   94篇
  1990年   81篇
  1989年   87篇
  1988年   67篇
  1987年   76篇
  1986年   67篇
  1985年   72篇
  1984年   57篇
  1983年   54篇
  1981年   25篇
  1980年   28篇
  1979年   28篇
  1978年   35篇
  1977年   27篇
  1976年   28篇
  1974年   41篇
  1973年   34篇
  1972年   25篇
排序方式: 共有5222条查询结果,搜索用时 15 毫秒
101.
To investigate whether the therapeutic effect of etidronate is affected by the time of ingestion we have retrospectively studied 110 osteoporotic patients. They had been taking etidronate according to the manufacturer's instructions for a mean duration of 2.6 years either on waking (n=47), on retiring (n=47), or during the day (n= 16). No significant differences were found between the three groups with respect to percentage change in bone mineral density at all sites either for the first year of treatment or for the mean yearly percent change throughout the total course of treatment. These findings suggest that the time of ingestion of etidronate does not influence the therapeutic effect if a two hour fast before and after ingestion is adhered to.  相似文献   
102.
103.
104.
105.
Cushing's syndrome due to nodular adrenal hyperplasia comprises a clinically and biochemically heterogeneous group of disorders whose pathogenesis is unclear. We describe two patients with atypical steroid dynamics and large unilateral adrenal nodules who had pituitary ACTH-dependent disease. In the differential diagnosis of Cushing's syndrome, we recommend repeated ACTH measurement and selective venous sampling—particularly in those patients with impaired dexamethasone suppressibility and abnormal findings on computerized tomography.  相似文献   
106.
To explore changes in the epidemiology of typhoid fever in the United States, cases reported to the Morbidity and Mortality Weekly Report (MMWR) and typhoid case report forms submitted by state and local governments are reviewed. The incidence of typhoid fever in the United States fell from one case per 100,000 population in 1955 to 0.2 cases per 100,000 in 1966 and has since remained fairly stable. Review of case report forms for 2,666 cases of acute typhoid fever that occurred between 1975 and 1984 showed that 62% were imported, in contrast to only 33% during 1967-1972. The proportion of cases imported has continued to rise, reaching 69% in 1984. The major sources of the 1975-1984 cases were Mexico (39%) and India (14%). The case-fatality rate was 1.3%. Antimicrobial resistance was a minor problem, and large outbreaks were unusual. Further decline in the incidence of typhoid fever in the United States probably must await the advent of an effective vaccine with minimal adverse effects for use by travelers.  相似文献   
107.
108.
PurposeEating disorders and their core symptoms (eg, binge eating, body weight/shape concerns) disproportionately affect females, and these sex-differentiated effects become prominent during and after puberty. Although psychosocial influences such as heightened sociocultural pressures for thinness in girls and women contribute to this sex imbalance, biological factors could also play an important role.MethodsThis narrative review summarizes evidence of biological factors underlying the sex-differentiated prevalence of eating pathology as well as within-sex variability in risk.FindingsThere are sex differences in the pubertal emergence of genetic effects on eating pathology (adrenarche in males; gonadarche in females), and at least some genetic contributions to eating pathology seem to vary between the sexes. Furthermore, sex steroid hormones (eg, testosterone, estradiol, progesterone) are leading contributors to differential risk for eating pathology in males and females across the life span. Emerging data suggest that between-sex and within-sex variability in risk might occur via hormone-driven modulation (activation/deactivation) of genetic influences and neural responsiveness to food-related cues.ImplicationsThere is a biological basis to heightened risk for eating pathology in females, relative to males, as well as unique biological influences within each sex. Findings from this review highlight the importance of studying both sexes and considering sex-specific biological mechanisms that may underlie differential risk for eating pathology  相似文献   
109.
110.
ObjectivesMobile stroke unit (MSU) has been shown to rapidly provide pre-hospital thrombolysis in acute ischemic stroke (AIS). MSU encounters neurological disorders other than AIS that require emergent treatment.Methods/MaterialsWe obtained pre-hospital diagnosis and treatment data from the prospectively collected dataset on 221 consecutive MSU encounters. Based on initial clinical evaluation and neuroimaging obtained on MSU, the diagnosis of AIS (definite, probable, and possible AIS, transient ischemic attack), intracranial hemorrhage, and likely stroke mimics was made.ResultsFrom July 2014 to April 2015, 221 patients were treated on MSU. 78 (35%) patients had initial clinical diagnosis of definite/probable AIS or TIA, 69 (31%) were diagnosed as possible AIS or TIA, 15 (7%) had intracranial hemorrhage while 59 patients (27%) were diagnosed as likely stroke mimics. Stroke mimics encountered included 13 (6%) metabolic encephalopathy, 11 (5%) seizures, 9 (4%) migraines, 3 (1%) substance abuse, 2 (1%) CNS tumor, 3 (1%) infectious etiology and 3 (1%) hypoglycemia. Fifty-four (24%) patients received non-thrombolytic treatments on MSUConclusionAbout one third of MSU encounters were not AIS initially, including intracranial hemorrhage and stroke mimics. MSU can be utilized to provide pre-hospital treatments in emergent neurological conditions other than AIS.  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