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   3230445篇
  免费   248895篇
  国内免费   5630篇
耳鼻咽喉   47267篇
儿科学   102574篇
妇产科学   89581篇
基础医学   459976篇
口腔科学   93023篇
临床医学   289809篇
内科学   626831篇
皮肤病学   66737篇
神经病学   265592篇
特种医学   128409篇
外国民族医学   1170篇
外科学   490297篇
综合类   74278篇
现状与发展   2篇
一般理论   1202篇
预防医学   255495篇
眼科学   76023篇
药学   243139篇
  5篇
中国医学   6006篇
肿瘤学   167554篇
  2018年   32076篇
  2016年   27263篇
  2015年   30971篇
  2014年   44182篇
  2013年   67606篇
  2012年   91516篇
  2011年   96992篇
  2010年   57082篇
  2009年   54466篇
  2008年   92456篇
  2007年   99165篇
  2006年   100336篇
  2005年   97951篇
  2004年   94429篇
  2003年   91096篇
  2002年   90155篇
  2001年   146305篇
  2000年   151192篇
  1999年   128092篇
  1998年   37321篇
  1997年   33623篇
  1996年   33565篇
  1995年   32340篇
  1994年   30404篇
  1993年   28289篇
  1992年   103654篇
  1991年   100858篇
  1990年   98148篇
  1989年   94875篇
  1988年   88141篇
  1987年   86730篇
  1986年   82386篇
  1985年   78914篇
  1984年   59648篇
  1983年   51105篇
  1982年   30993篇
  1981年   27561篇
  1980年   25844篇
  1979年   56315篇
  1978年   39805篇
  1977年   33717篇
  1976年   31872篇
  1975年   34071篇
  1974年   41452篇
  1973年   39499篇
  1972年   37330篇
  1971年   34572篇
  1970年   32463篇
  1969年   30471篇
  1968年   28213篇
排序方式: 共有10000条查询结果,搜索用时 16 毫秒
51.
There is some evidence suggesting that Parkinson's disease (PD) patients exhibit lower body weight when compared to age-matched healthy subjects. Low body mass index (BMI) is correlated with low bone mineral density, both of which are major risk factors for hip fractures. Possible determinants of weight loss in PD patients include hyposmia, impaired hand-mouth coordination, difficulty chewing, dysphagia, intestinal hypomotility, depression, decreased reward processing of dopaminergic mesolimbic regions, nausea, and anorexia as the side effects of medication, and increased energy requirements due to muscular rigidity and involuntary movements. It is unclear whether PD patients in general, or only a subgroup of those affected, definitely show lower BMI in the advanced stages of the disease. We therefore recommend that the body weight of PD patients be monitored monthly as the disease progresses, and that a patient's nutrition should be supplemented with sufficient amounts of vitamin D and calcium to reduce the risk of hip fractures and strengthen bone density. Because meal times may coincide with unpredictable off periods associated with akinesia and impaired hand-mouth coordination, PD patients also need flexible food schedules that accommodate the associated symptoms of this disease.  相似文献   
52.
Ninety-seven inpatients with tardive dyskinesia (average AIMS score = 13), the majority of whom were schizophrenic, were studied. Forty patients were Caucasian, and 57 were African-American. The APOE genotypes of these patients were compared to previously published genotypes of controls and with previously published studies of APOE genotypes in patients with schizophrenia. There were no significant differences in APOE allele frequencies comparing the African-American tardive dyskinesia population and the African-American control groups. In contrast, significant (< 0.05) P values were obtained comparing the Caucasian tardive dyskinesia population to the Caucasian controls, when comparing allele frequencies and genotypic frequencies. This study suggests that Caucasians bearing an APOE2 allele are at increased risk of developing tardive dyskinesia, whereas African-Americans are not. APOE genotype-specific risks of both tardive dyskinesia and Alzheimer's disease that vary across populations could be due to recruitment of patients or controls or could be due to modifying effects of differing genetic or environmental backgrounds. The mechanism by which the APOE2 allele increases risk of tardive dyskinesia is not known. Further information about the mechanisms of increased risk of tardive dyskinesia could result in stratification of prescribing practices weighing the costs of medications against the relative risk of side effects.  相似文献   
53.
54.
The precise molecular cause of insulin resistance has not yet been elucidated. Resistance to the normal action of insulin contributes to the pathogenesis of a number of common human disorders, including type 1 (insulin-dependent) and type 2 (non-insulin-dependent) diabetes mellitus, hypertension, and the Metabolic Syndrome X, thus constituting a major public health problem. A disease program aimed at combating this disorder should focus on the identification of targets for therapeutic intervention which may overcome insulin resistance and hence the associated metabolic consequences characteristic of the Metabolic Syndrome. Although the primary defect in the pathogenesis of type 2 diabetes is unknown, genetic and environmental factors are likely to contribute to the manifestation of this progressive metabolic disorder, which is usually not clinically apparent until mid-life. Defects at the level of glucose uptake/phosphorylation characterize insulin resistance in skeletal muscle of type 2 diabetic patients. Identification of putative components of the insulin receptor-signaling pathway may offer insights into mechanisms involved in insulin resistance. Enhanced flux of free fatty acids due to impaired lipid metabolism may contribute to impaired insulin secretion and peripheral insulin resistance. Genes regulating lipolysis are prime candidates for susceptibility towards the metabolic syndrome. Here we describe pathways constituting complex interactions that control glucose homeostasis. We will be considering (1) regulation of glucose uptake by the insulin receptor signaling pathway, and (2) control of adipogenesis and insulin sensitivity by the sterol response element binding protein (SREBP) pathway.  相似文献   
55.
56.
57.
58.
59.
    
Ohne Zusammenfassung
Endpunkt- und Verlaufsmessungen bei entzündlichen rheumatischen Erkrankungen in Studien und Praxis
  相似文献   
60.
We report the case of a 38-year-old woman who presented with chronic lower abdominal pain. Her past medical history included a splenectomy due to abdominal trauma. Ultrasound examination revealed four pelvic tumors which, upon laparotomy, were found to be the result of splenosis. Approximately 100 cases of splenosis have been reported but only a minority of them have been published in the gynecological literature. Our case indicates that those involved in pelvic scanning (even of asymptomatic women) and/or treating those complaining of lower abdominal pain or presenting with pelvic tumors should be aware of splenosis as a possible diagnosis.  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