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   60970篇
  免费   3613篇
  国内免费   369篇
耳鼻咽喉   473篇
儿科学   1848篇
妇产科学   1641篇
基础医学   7776篇
口腔科学   1395篇
临床医学   5689篇
内科学   14056篇
皮肤病学   1174篇
神经病学   6484篇
特种医学   2178篇
外国民族医学   2篇
外科学   8058篇
综合类   222篇
一般理论   21篇
预防医学   4040篇
眼科学   985篇
药学   3686篇
  1篇
中国医学   95篇
肿瘤学   5128篇
  2024年   58篇
  2023年   571篇
  2022年   957篇
  2021年   2183篇
  2020年   1280篇
  2019年   1813篇
  2018年   2122篇
  2017年   1495篇
  2016年   1757篇
  2015年   1962篇
  2014年   2719篇
  2013年   3428篇
  2012年   5098篇
  2011年   5094篇
  2010年   2669篇
  2009年   2474篇
  2008年   4251篇
  2007年   4013篇
  2006年   3788篇
  2005年   3672篇
  2004年   3214篇
  2003年   2884篇
  2002年   2606篇
  2001年   394篇
  2000年   281篇
  1999年   426篇
  1998年   479篇
  1997年   375篇
  1996年   318篇
  1995年   299篇
  1994年   264篇
  1993年   231篇
  1992年   190篇
  1991年   163篇
  1990年   150篇
  1989年   117篇
  1988年   103篇
  1987年   103篇
  1986年   100篇
  1985年   81篇
  1984年   115篇
  1983年   65篇
  1982年   93篇
  1981年   66篇
  1980年   64篇
  1979年   37篇
  1978年   45篇
  1977年   34篇
  1976年   27篇
  1972年   25篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Anaplastic thyroid carcinoma (ATC) is an aggressive thyroid malignancy with high mortality rate. This malignancy arises in thyroid follicular cells either denovo or with an associated differentiated thyroid carcinoma component. Clinically, it usually presents as a rapidly enlarging mass, pain and locally compressive symptoms. Histopathologic variability and heterogeneity often pose diagnostic challenges, especially in scant and paucicellular specimens. This article describes the clinical, histopathologic and molecular features of ATC and also addresses the associated diagnostic limitations and challenges.  相似文献   
2.
With easy chemical synthesis from its precursor, methamphetamine (MA) is now widespread in many countries. The abuse of methamphetamine is associated with several negative effects on health, because MA is a neurotoxin and a dangerous central nervous system stimulant. It changes levels of neurotransmitters in the brain, releasing dopamine and inhibiting nor epinephrine uptake which increases sympathetic nervous system activity and can lead to cardiac arrhythmia, hypertension and tachypnea. The consequences of MA abuse are clearly manifested in oral diseases (like “meth mouth”) which is characterised by extensive caries, teeth grinding with ensuing dental wear and trismus. The present review was designed to fill the gap in knowledge about methamphetamine abuse in the European Union (EU) and to illustrate the main clinical effects of prolonged use. After describing the pharmacology and systemic effects of methamphetamine and concentrating on its effects on the mouth, the present review compares the epidemiology and incidence of abuse in the world, particularly the USA and the EU. Key words:Methamphetamine, “Meth mouth”, drug abuse, oral health.  相似文献   
3.
Context: Treatment of primary spinal syringomyelia is still controversial. Among others, shunting syrinx fluid to the subarachnoid, peritoneal or pleural space has been utilized with varying success. Shunt obstruction, migration, and infection represent the most common complications of these procedures.

Findings: The authors present the case of an 81-year-old woman who developed an unusual neurological deterioration resembling a subacute posttraumatic ascending myelopathy (SPAM) after the insertion of a syringosubarachnoid shunt for the treatment of slow-growing D10 syringomyelia.

Conclusion/Clinical Relevance: To date, no cases of SPAM secondary to the insertion of a syringosubarachnoid shunt for the treatment of syringomyelia have been reported. The potential pathogenesis related to this phenomenon is discussed.  相似文献   
4.
The present study aimed at measuring seropositivities for infection by Ascaris suum and Toxocara canis using the excretory/secretory (E/S) antigens from Ascaris suum (AES) and Toxocara canis (TES) within an indigenous population. In addition, quantification of cytokine expressions in peripheral blood cells was determined. A total of 50 Warao indigenous were included; of which 43 were adults and seven children. In adults, 44.1% were seropositive for both parasites; whereas children had only seropositivity to one or the other helminth. For ascariosis, the percentage of AES seropositivity in adults and children was high; 23.3% and 57.1%, respectively. While that for toxocariosis, the percentage of TES seropositivity in adults and children was low; 9.3% and 14.3%, respectively. The percentage of seronegativity was comparable for AES and TES antigens in adults (27.9%) and children (28.6%). When positive sera were analyzed by Western blotting technique using AES antigens; three bands of 97.2, 193.6 and 200.2 kDas were mostly recognized. When the TES antigens were used, nine major bands were mostly identified; 47.4, 52.2, 84.9, 98.2, 119.1, 131.3, 175.6, 184.4 and 193.6 kDas. Stool examinations showed that Blastocystis hominis, Hymenolepis nana and Entamoeba coli were the most commonly observed intestinal parasites. Quantification of cytokines IFN-γ, IL-2, IL-6, TGF-β, TNF-α, IL-10 and IL-4 expressions showed that there was only a significant increased expression of IL-4 in indigenous with TES seropositivity (p < 0.002). Ascaris and Toxocara seropositivity was prevalent among Warao indigenous.  相似文献   
5.
6.
7.
8.
9.
10.
ABSTRACT

Objective

To investigate primary care physician clinical practice patterns, barriers, and education surrounding pediatric physical activity (PA), and to compare practice patterns by discipline.  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