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   1277784篇
  免费   99990篇
  国内免费   1993篇
耳鼻咽喉   18448篇
儿科学   44435篇
妇产科学   35054篇
基础医学   182393篇
口腔科学   33817篇
临床医学   111252篇
内科学   258314篇
皮肤病学   28052篇
神经病学   100476篇
特种医学   51241篇
外国民族医学   662篇
外科学   196566篇
综合类   27069篇
现状与发展   1篇
一般理论   378篇
预防医学   95739篇
眼科学   27925篇
药学   94822篇
  2篇
中国医学   2422篇
肿瘤学   70699篇
  2018年   13147篇
  2017年   9984篇
  2016年   10918篇
  2015年   12388篇
  2014年   17197篇
  2013年   26250篇
  2012年   36080篇
  2011年   38113篇
  2010年   22831篇
  2009年   21850篇
  2008年   36693篇
  2007年   39308篇
  2006年   39569篇
  2005年   38509篇
  2004年   37675篇
  2003年   36507篇
  2002年   35853篇
  2001年   64030篇
  2000年   66567篇
  1999年   56452篇
  1998年   15142篇
  1997年   13780篇
  1996年   14211篇
  1995年   13470篇
  1994年   12785篇
  1993年   11805篇
  1992年   44620篇
  1991年   43500篇
  1990年   42274篇
  1989年   40171篇
  1988年   36934篇
  1987年   36274篇
  1986年   33655篇
  1985年   32315篇
  1984年   24169篇
  1983年   20297篇
  1982年   11752篇
  1981年   10709篇
  1980年   9534篇
  1979年   21368篇
  1978年   14845篇
  1977年   12549篇
  1976年   11714篇
  1975年   12638篇
  1974年   14695篇
  1973年   14140篇
  1972年   12972篇
  1971年   11759篇
  1970年   11066篇
  1969年   10043篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
81.
Thyroid diseases are common, and use of levothyroxine is increasing worldwide. We investigated the influence of gender, race and socioeconomic status on the diagnosis and treatment of thyroid disorders using data from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), a multicenter cohort study of civil servants (35-74 years of age) from six Brazilian cities. Diagnosis of thyroid dysfunction was by thyrotropin (TSH), and free thyroxine (FT4) if TSH was altered, and the use of specific medications. Multivariate logistic regression models were constructed using overt hyperthyroidism/hypothyroidism and levothyroxine use as dependent variables and sociodemographic characteristics as independent variables. The frequencies of overt hyper- and hypothyroidism were 0.7 and 7.4%, respectively. Using whites as the reference ethnicity, brown, and black race were protective for overt hypothyroidism (OR=0.76, 95%CI=0.64-0.89, and OR=0.53, 95%CI=0.43-0.67, respectively, and black race was associated with overt hyperthyroidism (OR=1.82, 95%CI=1.06-3.11). Frequency of hypothyroidism treatment was higher in women, browns, highly educated participants and those with high net family incomes. After multivariate adjustment, levothyroxine use was associated with female gender (OR=6.06, 95%CI=3.19-11.49) and high net family income (OR=3.23, 95%CI=1.02-10.23). Frequency of hyperthyroidism treatment was higher in older than in younger individuals. Sociodemographic factors strongly influenced the diagnosis and treatment of thyroid disorders, including the use of levothyroxine.  相似文献   
82.
83.
84.
Psoriasis is a chronic, inflammatory, immune‐mediated disease. Approximately 30% of patients have disease onset before age 18 years. Psoriasis in children and adolescents may be difficult to control, with subsequent poor quality of life and psychosocial consequences. We describe the case of a 12‐year‐old boy with severe, refractory, chronic plaque psoriasis for 6 years. Various therapeutic regimens including different topical corticosteroids, topical vitamin D analogs, phototherapy, photochemotherapy, systemic therapy with methotrexate, cyclosporin, and combination therapies showed only partial or transient responses with frequent relapses. Because anti‐interleukin‐12/23 agents have been successfully used in adults with psoriasis, ustekinumab was initiated and our patient showed a rapid, excellent, sustained response. No recurrence or flares have been observed after 33 months of follow‐up. This case illustrates that ustekinumab may be an effective and safe therapeutic option in adolescents with psoriasis.  相似文献   
85.
86.
87.
88.
Moderate weight loss improves numerous risk factors for cardiometabolic disease; however, long-term weight loss maintenance (WLM) is often thwarted by metabolic adaptations that suppress energy expenditure and facilitate weight regain. Skeletal muscle has a prominent role in energy homeostasis; therefore, we investigated the effect of WLM and weight regain on skeletal muscle in rodents. In skeletal muscle of obesity-prone rats, WLM reduced fat oxidative capacity and downregulated genes involved in fat metabolism. Interestingly, even after weight was regained, genes involved in fat metabolism were also reduced. We then subjected mice with skeletal muscle lipoprotein lipase overexpression (mCK-hLPL), which augments fat metabolism, to WLM and weight regain and found that mCK-hLPL attenuates weight regain by potentiating energy expenditure. Irrespective of genotype, weight regain suppressed dietary fat oxidation and downregulated genes involved in fat metabolism in skeletal muscle. However, mCK-hLPL mice oxidized more fat throughout weight regain and had greater expression of genes involved in fat metabolism and lower expression of genes involved in carbohydrate metabolism during WLM and regain. In summary, these results suggest that skeletal muscle fat oxidation is reduced during WLM and regain, and therapies that improve skeletal muscle fat metabolism may attenuate rapid weight regain.  相似文献   
89.
90.
Background: Dense deposit disease and atypical hemolytic uremic syndrome are often caused by Complement Factor H (CFH) mutations. This study describes the retinal abnormalities in dense deposit disease and, for the first time, atypical haemolytic uremic syndrome. It also reviews our understanding of drusen pathogenesis and their relevance for glomerular disease. Methods: Six individuals with dense deposit disease and one with atypical haemolytic uremic syndrome were studied from 2 to 40 years after presentation. Five had renal transplants. All four who had genetic testing had CFH mutations. Individuals underwent ophthalmological review and retinal photography, and in some cases, optical coherence tomography, and further tests of retinal function. Results: All subjects with dense deposit disease had impaired night vision and retinal drusen or whitish-yellow deposits. Retinal atrophy, pigmentation, and hemorrhage were common. In late disease, peripheral vision was restricted, central vision was distorted, and there were scotoma from sub-retinal choroidal neovascular membranes and atypical serous retinopathy. Drusen were present but less prominent in the young person with atypical uremic syndrome due to a heterozygous CFH mutation. Conclusions: Drusen are common in forms of C3 glomerulopathy caused by compound heterozygous or heterozygous CFH mutations. They are useful diagnostically but also impair vision. Drusen have an identical composition to glomerular deposits. They are also identical to the drusen of age-related macular degeneration, and may respond to the same treatments. Individuals with a C3 glomerulopathy should be assessed ophthalmologically at diagnosis, and monitored regularly for vision-threatening complications.  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