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   229352篇
  免费   13458篇
  国内免费   774篇
耳鼻咽喉   2915篇
儿科学   7019篇
妇产科学   4842篇
基础医学   30226篇
口腔科学   10270篇
临床医学   16931篇
内科学   53491篇
皮肤病学   5737篇
神经病学   19598篇
特种医学   6914篇
外国民族医学   26篇
外科学   30140篇
综合类   1699篇
现状与发展   1篇
一般理论   79篇
预防医学   21505篇
眼科学   4217篇
药学   13479篇
中国医学   842篇
肿瘤学   13653篇
  2023年   1354篇
  2022年   2928篇
  2021年   5808篇
  2020年   3610篇
  2019年   5149篇
  2018年   6902篇
  2017年   5053篇
  2016年   4894篇
  2015年   5683篇
  2014年   7846篇
  2013年   9853篇
  2012年   15482篇
  2011年   16098篇
  2010年   8457篇
  2009年   7500篇
  2008年   12634篇
  2007年   13293篇
  2006年   12334篇
  2005年   12467篇
  2004年   11539篇
  2003年   10375篇
  2002年   8308篇
  2001年   5333篇
  2000年   5249篇
  1999年   4728篇
  1998年   2002篇
  1997年   1637篇
  1996年   1590篇
  1995年   1370篇
  1994年   1295篇
  1993年   1159篇
  1992年   2825篇
  1991年   2710篇
  1990年   2454篇
  1989年   2417篇
  1988年   2195篇
  1987年   2037篇
  1986年   1899篇
  1985年   1839篇
  1984年   1351篇
  1983年   1084篇
  1982年   625篇
  1981年   588篇
  1980年   576篇
  1979年   984篇
  1978年   658篇
  1977年   542篇
  1975年   584篇
  1974年   572篇
  1973年   567篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
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   
42.
43.
44.
45.
46.
47.
48.
Classical Kaposi sarcoma (KS) usually appears on lower extremities accompanied or preceded by local lymphedema. However, the development in areas of chronic lymphedema of the arms following mastectomy, mimicking a Stewart–Treves syndrome, has rarely been described. We report an 81‐year‐old woman who developed multiple, erythematous to purple tumors, located on areas of post mastectomy lymphedema. Histopathological examination evidenced several dermal nodules formed by spindle‐shaped cells that delimitated slit‐like vascular spaces with some red cell extravasation. Immunohistochemically, the human herpesvirus type 8 (HHV‐8) latent nuclear antigen‐1 was detected in the nuclei of most tumoral cells confirming the diagnosis of KS. Lymphedema could promote the development of certain tumors by altering immunocompetence. Although angiosarcoma (AS) is the most frequent neoplasia arising in the setting of chronic lymphedema, other tumors such as benign lymphangiomatous papules (BLAP) or KS can also develop in lymphedematous limbs. It is important to establish the difference between AS and KS because their prognosis and treatment are very different. Identification by immunohistochemistry of HHV‐8 is useful for the distinction between KS and AS or BLAP.  相似文献   
49.
Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital condition. It responds well to early diagnosis and treatment, but otherwise the prognosis is poor. We present our case series of 12 patients (mean age, 2 ± 2.58 yr; age range, 2 mo–8 yr), emphasizing the diagnostic process and discussing our surgical results. The diagnosis of ALCAPA should be suspected in infants who have dilated cardiomyopathy with electrocardiographic changes that suggest ischemia, and in older children who have isolated mitral regurgitation. When clinical suspicion is high, the results of 2-dimensional echocardiography combined with color-flow Doppler studies in expert hands can establish the diagnosis, thus avoiding angiography in critically ill infants. The treatment of choice in our patients was transfer and reimplantation of the left coronary artery onto the ascending aorta. There were 2 deaths: both were infants in extremis who underwent emergency surgery. An older child with severe ventricular dysfunction was given mechanical ventricular assistance and then heart transplantation. As of this report, all 10 survivors remained well and asymptomatic.  相似文献   
50.
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