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   31865篇
  免费   2729篇
  国内免费   69篇
耳鼻咽喉   277篇
儿科学   715篇
妇产科学   538篇
基础医学   3884篇
口腔科学   912篇
临床医学   4545篇
内科学   6396篇
皮肤病学   674篇
神经病学   2476篇
特种医学   1058篇
外科学   4032篇
综合类   546篇
一般理论   33篇
预防医学   3815篇
眼科学   459篇
药学   2505篇
中国医学   27篇
肿瘤学   1771篇
  2022年   190篇
  2021年   467篇
  2020年   290篇
  2019年   451篇
  2018年   523篇
  2017年   379篇
  2016年   449篇
  2015年   517篇
  2014年   691篇
  2013年   1177篇
  2012年   1567篇
  2011年   1592篇
  2010年   913篇
  2009年   834篇
  2008年   1502篇
  2007年   1573篇
  2006年   1593篇
  2005年   1623篇
  2004年   1534篇
  2003年   1430篇
  2002年   1418篇
  2001年   1018篇
  2000年   1046篇
  1999年   921篇
  1998年   376篇
  1997年   335篇
  1996年   298篇
  1995年   303篇
  1994年   257篇
  1993年   254篇
  1992年   642篇
  1991年   652篇
  1990年   614篇
  1989年   551篇
  1988年   515篇
  1987年   503篇
  1986年   493篇
  1985年   493篇
  1984年   371篇
  1983年   325篇
  1982年   251篇
  1981年   229篇
  1979年   341篇
  1978年   253篇
  1977年   209篇
  1974年   224篇
  1973年   211篇
  1972年   174篇
  1971年   197篇
  1970年   173篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Cutaneous leiomyomas are rare benign smooth‐muscle tumors. These lesions are distinguished based on their cell of origin and are subclassified as pilar leiomyoma, angioleiomyoma, and genital‐type leiomyoma. Nipple leiomyoma is the least common genital‐type leiomyoma, arising from the dartoic muscle cell of the nipple. Histologic examination of the lesion is necessary for definitive diagnosis, and these uncommon tumors can pose a diagnostic challenge. We describe herein a series of six nipple leiomyomas with a spectrum of histologic appearances.  相似文献   
2.
3.
4.
5.
Bowel diseases of prematurity, including necrotizing enterocolitis, are dreaded ailments of neonates. Early diagnosis is difficult, with clinical and radiographic findings often inconclusive. We present a novel use of contrast-enhanced ultrasound in detection of pediatric bowel disease. Early identification of compromised blood flow or an at-risk bowel can be quantitatively detected and monitored. This ability has implications for guidance of emerging therapies, allowing targeting of inflammation. These findings represent an advancement in detection of bowel disease in neonates.  相似文献   
6.
This study explored the relationship between active mediation, exposure to Daniel Tiger’s Neighborhood, and key indicators of preschoolers’ social and emotional development. One hundred and twenty-seven children aged 2–6 either watched or did not watch 10 episodes of Daniel Tiger’s Neighborhood over a two-week period. Results revealed that preschoolers who watched the program exhibited higher levels of empathy, self-efficacy, and emotion recognition when their regular TV-watching experiences are frequently accompanied by active mediation. This was especially true for younger preschoolers and preschoolers from low-income families. Implications for policy-makers, parents, producers of prosocial programming, and educators are discussed.  相似文献   
7.
8.
Rifamycins (rifampin, rifabutin, and rifapentine) play an essential role in the treatment of mycobacterial and some nonmycobacterial infections. They also induce the activity of various drug transporting and metabolizing enzymes, which can impact the concentrations and efficacy of substrates. Many anticoagulant and antiplatelet (AC/AP) agents are substrates of these enzymes and have narrow therapeutic indices, leading to risks of thrombosis or bleeding when coadministered with rifamycins. The objective of this systematic review was to evaluate the effects on AC/AP pharmacokinetics, laboratory markers, and clinical safety and efficacy of combined use with rifamycins. A systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidance was performed. The PubMed, Embase, and Web of Science databases were queried for English-language reports on combination use of rifamycins and AC/AP agents from database inception through August 2021. The 29 studies identified examined warfarin (n = 17), direct oral anticoagulants (DOACs) (n = 8), and antiplatelet agents (n = 4) combined with rifampin (n = 28) or rifabutin (n = 1). Eleven studies were case reports or small case series; 14 reported on pharmacokinetic or laboratory markers in healthy volunteers. Rifampin-warfarin combinations led to reductions in warfarin area under the curve (AUC) of 15%–74%, with variability by warfarin isomer and study. Warfarin dose increases of up to 3–5 times prerifampin doses were required to maintain coagulation parameters in the therapeutic range. DOAC AUCs were decreased by 20%–67%, with variability by individual agent and with rifampin versus rifabutin. The active metabolite of clopidogrel increased substantially with rifampin coadministration, whereas prasugrel was largely unaffected and ticagrelor saw decreases. Our review suggests most combinations of AC/AP agents and rifampin are problematic. Further studies are required to determine whether rifabutin or rifapentine could be safe alternatives for coadministration with AC/AP drugs.  相似文献   
9.
10.
Nickel is the leading cause of allergic contact dermatitis (ACD) from early childhood through adolescence. Studies have shown that skin piercings and other nickel‐laden exposures can trigger the onset of nickel ACD in those who are susceptible. Nickel ACD causes a vast amount of cutaneous disease in children. Cases of nickel ACD in children have been reported in peer‐reviewed literature from 28 states. Common items that contain inciting nickel include jewelry, coins, zippers, belts, tools, toys, chair studs, cases for cell phones and tablets, and dental appliances. The diagnosis of nickel ACD has been routinely confirmed by patch testing in children older than 6 months suspected of ACD from nickel. Unlike in Europe, there are no mandatory restrictions legislated for nickel exposure in the United States. Denmark has demonstrated that regulation of the nickel content in metals can lower the risk of ACD and the associated health care–related costs that arise from excess nickel exposure. To further awareness, this article reviews the prominent role of nickel in pediatric skin disease in the United States. It discusses the need for a campaign by caretakers to reduce nickel‐related morbidity. Lastly, it promotes the model of European legislation as a successful intervention in the prevention of nickel ACD.  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