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   12678篇
  免费   1200篇
  国内免费   86篇
耳鼻咽喉   99篇
儿科学   535篇
妇产科学   341篇
基础医学   1756篇
口腔科学   393篇
临床医学   1403篇
内科学   2597篇
皮肤病学   211篇
神经病学   1009篇
特种医学   674篇
外科学   1547篇
综合类   331篇
一般理论   19篇
预防医学   1354篇
眼科学   122篇
药学   935篇
中国医学   28篇
肿瘤学   610篇
  2021年   198篇
  2020年   88篇
  2019年   175篇
  2018年   250篇
  2017年   148篇
  2016年   199篇
  2015年   219篇
  2014年   276篇
  2013年   394篇
  2012年   632篇
  2011年   588篇
  2010年   360篇
  2009年   381篇
  2008年   561篇
  2007年   603篇
  2006年   533篇
  2005年   511篇
  2004年   469篇
  2003年   433篇
  2002年   426篇
  2001年   415篇
  2000年   420篇
  1999年   358篇
  1998年   214篇
  1997年   198篇
  1996年   153篇
  1995年   141篇
  1994年   150篇
  1993年   140篇
  1992年   308篇
  1991年   287篇
  1990年   279篇
  1989年   283篇
  1988年   269篇
  1987年   261篇
  1986年   254篇
  1985年   213篇
  1984年   168篇
  1983年   167篇
  1982年   105篇
  1981年   86篇
  1980年   94篇
  1979年   171篇
  1978年   129篇
  1977年   120篇
  1976年   93篇
  1975年   103篇
  1974年   103篇
  1973年   89篇
  1972年   78篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
SUMMARY A young patient presenting with splenomegaly and hypersplenism was inadvertently found to have selective IgA deficiency. There were no symptoms of immunodeficiency and the patient responded well to splenectomy, with return of blood counts to normal without adverse effects. No other cause for the hypersplenism was found. We postulate selective IgA deficiency as a cause of splenomegaly and hypersplenism.  相似文献   
42.
Pulmonary Function in Survivors of Wilms' Tumor   总被引:1,自引:0,他引:1  
The respiratory status of 47 patients surviving childhood Wilms' tumor was studied. The group that had receivedflnnk irradiation (which impinges on the lower lung) (n - 17) had a sisnijGantly lower mean percent predicted for forced expiratory volume in one second, residual volume, and total lung capaci(v when compared to those who had received no irradiation (n - 23). Those patients who had received whole-lung irradiation (n - 3) had sisnijicantly lower transfn. foctor for carbon monoxide and gas transfer per unit lung volume whm compared to the nonirradiated group (n - 23). There was no sipiftiant dimue in the prevalence of respiratory symptoms between the three groups. Patients receiving any form of radiotherapy for Wilms' tumor may have abnormulities o f pulmonary function and should have pulmonary function tests performed as part o f their long-tmn follow-up.  相似文献   
43.
Two human parathyroid hormone-related protein (hPTHrP) fragments were tested for effects on maternofetal transfer of 45Ca and Mg across the in-situ perfused rat placenta at 21 days of gestation (term = 23 days). The fetal placental circulation was perfused with a Mg-free Krebs-Ringer solution and the unidirectional maternofetal clearance (Kmf) of 45Ca and Mg compared with that of 51Cr-EDTA, the latter being employed as a paracellular diffusional marker. Placental perfusion with hPTHrP(1-34) (100 ng/ml) or hPTHrP(75-86)amide (50 ng/ml) did not significantly alter the Kmf of 45Ca or that of Mg. In separate rats, however, hPTHrP(1-34) but not hPTHrP(75-86)amide stimulated marked placental cyclic AMP (cAMP) release, the peak response of 63 +/- 7 pmol/min occurring 10 min after the beginning of the peptide perfusion. A lower dose of hPTHrP(1-34) (4 ng/ml) produced a similar peak release of cAMP, as did [Nle8,21, Tyr34]-rPTH(1-34)amide (4 ng/ml) and the adenylate cyclase agonist forskolin (17 mumol/l). Forskolin also rapidly increased the Kmf of 45Ca but not that of Mg or 51Cr-EDTA. The present study indicates that hPTHrP does not acutely affect maternofetal transfer of Ca or Mg across the perfused rat placenta. The data also question the role played by cAMP in the stimulatory actions of forskolin on placental Ca transport.  相似文献   
44.
A toxicologic-pathologic study of isobutyl-2-cyanoacrylate (Bucrylate) was carried out first in dogs and then in humans whose arteriovenous malformations were infused with this embolic agent. The canine specimens obtained at 7, 18, 28, and 147 days after embolization showed the development of a mild histiocytic giant cell reaction, which evolved to end-state sclerotic arteritis. The response was confined to the vessels and did not involve contiguous parenchymal tissues. Ten human specimens, obtained from 1 hr to 7 years after treatment, showed a similar bland reaction with no evidence of suppuration or premalignant changes.  相似文献   
45.
A study was made of the pattern of distribution of mercury in the tissues of some plant species collected around a chlor-alkali factory in India. Different plants accumulated different levels of mercury in their tissues. Accumulation in leaves was the highest, followed by the stem and the root and, in some cases, the root and the stem. A significant correlation was noted between the mercury concentration of the soil and the plant tissues and between different tissues. Grazers (goats, sheep) also accumulated significant levels of mercury in their tissues.  相似文献   
46.
Reproductive and social histories of the first 100 patients attending the in vitro fertilisation (IVF) programme at National Women's Hospital, Auckland, have been studied. The average age at first treatment was 31.6 (SD 3.9) for women, and 34.2 (4.6) for men. The couples had been married 7.6 (3.3) years and had experienced 6.7 (3.2) years infertility. It was a second marriage for 16. The husbands had on average a higher social classing than the population (class: number [population]--1:16 (7%), 2:18 (14%), 3:42 (28%), 4:19 (29%), 5:4 (14%), 6:1 (8%); but this bias diminished in the next 159 couples. Nine couples withdrew before their quota of cycles, 7 from stress. Tubal disease was the cause of infertility in 93, but in 69 its origin was untraceable. In 22 it could be attributed to pelvic inflammatory disease (eight associated with IUCDs and 2 with sexually transmitted disease) and in two to sterilisation. Although 59 women had a history of having conceived, only 34 were parous, and only 11 had a child of the current union.  相似文献   
47.
Submersion injuries are a major cause of morbidity and mortality in children and young adults. The Emergency Department physician should be familiar with the epidemiology, pathophysiology, modes of therapy, and prognostic indicators in order to provide optimum resuscitation to the near-drowning victim, correct referral, and counseling to their families.  相似文献   
48.
49.
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