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   1499242篇
  免费   103636篇
  国内免费   2057篇
耳鼻咽喉   20026篇
儿科学   52754篇
妇产科学   39378篇
基础医学   206953篇
口腔科学   35602篇
临床医学   128055篇
内科学   297390篇
皮肤病学   29406篇
神经病学   121595篇
特种医学   61167篇
外国民族医学   660篇
外科学   231861篇
综合类   29996篇
现状与发展   2篇
一般理论   450篇
预防医学   118774篇
眼科学   31159篇
药学   107293篇
  2篇
中国医学   3078篇
肿瘤学   89334篇
  2019年   10643篇
  2018年   37170篇
  2017年   28943篇
  2016年   33094篇
  2015年   14655篇
  2014年   19732篇
  2013年   29225篇
  2012年   46037篇
  2011年   62487篇
  2010年   43150篇
  2009年   35040篇
  2008年   59485篇
  2007年   65446篇
  2006年   41856篇
  2005年   42888篇
  2004年   43312篇
  2003年   43522篇
  2002年   40583篇
  2001年   64569篇
  2000年   67335篇
  1999年   56860篇
  1998年   15606篇
  1997年   14227篇
  1996年   14443篇
  1995年   13738篇
  1994年   13061篇
  1993年   12037篇
  1992年   44741篇
  1991年   43693篇
  1990年   42440篇
  1989年   40289篇
  1988年   37033篇
  1987年   36396篇
  1986年   33758篇
  1985年   32425篇
  1984年   24243篇
  1983年   20363篇
  1982年   11845篇
  1981年   10739篇
  1979年   21457篇
  1978年   14910篇
  1977年   12562篇
  1976年   11775篇
  1975年   12643篇
  1974年   14719篇
  1973年   14137篇
  1972年   12962篇
  1971年   11741篇
  1970年   11092篇
  1969年   10065篇
排序方式: 共有10000条查询结果,搜索用时 187 毫秒
91.
92.
93.
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   
94.
95.
96.
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   
97.
We report a case of intestinal obstruction in a 73-year-old woman caused by ileocolic intussusception. The underlying cause was a giant submucosal ulcerating lipoma (6?×?3.3?×?3.8 cm) extending from the superior mucosal lip of Bauhin’s valve. Abdominal ultrasonography showed a pathognomonic target-like mass appearing as multiple concentric rings. CT scan confirmed the diagnosis. Because of apparent obstruction, a laparotomy with right hemicolectomy and ileocolic anastomosis was performed. Lipomas most frequently occur in the cecum and ascending colon where they represent the most common submucosal mesenchymal tumor. They typically occur in elderly women with an incidence that varies from 0.15 to 0.56 %. Pain, rectal bleeding, and obstruction are typical symptoms. When faced with an intussusception in children, reduction with air per rectum can be performed. In adults, however, malignant cell spreading and seeding is of big concern. Since approximately 20–50 % of all underlying causes are malignant, explorative surgery is favored in adults.  相似文献   
98.
99.
100.
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