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   2498589篇
  免费   196016篇
  国内免费   4260篇
耳鼻咽喉   38383篇
儿科学   76935篇
妇产科学   68498篇
基础医学   360256篇
口腔科学   70553篇
临床医学   220937篇
内科学   492262篇
皮肤病学   53757篇
神经病学   209722篇
特种医学   101161篇
外国民族医学   886篇
外科学   377965篇
综合类   56656篇
现状与发展   1篇
一般理论   981篇
预防医学   194817篇
眼科学   60638篇
药学   181705篇
  4篇
中国医学   4423篇
肿瘤学   128325篇
  2018年   24367篇
  2016年   20816篇
  2015年   26067篇
  2014年   36874篇
  2013年   55239篇
  2012年   71828篇
  2011年   75141篇
  2010年   45698篇
  2009年   44165篇
  2008年   71856篇
  2007年   76123篇
  2006年   77368篇
  2005年   74964篇
  2004年   72023篇
  2003年   68447篇
  2002年   66672篇
  2001年   113094篇
  2000年   117125篇
  1999年   99070篇
  1998年   28840篇
  1997年   26491篇
  1996年   26714篇
  1995年   26017篇
  1994年   24568篇
  1993年   22855篇
  1992年   80760篇
  1991年   77561篇
  1990年   74595篇
  1989年   71785篇
  1988年   66726篇
  1987年   65718篇
  1986年   62199篇
  1985年   59169篇
  1984年   45059篇
  1983年   38318篇
  1982年   23753篇
  1981年   21076篇
  1980年   19764篇
  1979年   42080篇
  1978年   29905篇
  1977年   25074篇
  1976年   23420篇
  1975年   24673篇
  1974年   30344篇
  1973年   28831篇
  1972年   26883篇
  1971年   24693篇
  1970年   23260篇
  1969年   21733篇
  1968年   19648篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
A detailed examination of quantitative relationships of pharmacological action with plasma and tissue concentrations of indomethacin has been undertaken in the rat, after single oral administration of two sustained release preparations. In this study, drug was assayed by high performance liquid chromatography, whereas antiinflammatory response was assessed through the carrageenin-induced edema test. Significant linear correlations (p less than 0.001) were found between logarithmically transformed percent inhibition of edema and logarithmically transformed plasma, as well as tissue levels of indomethacin. However, the lack of significance for partial correlation regarding tissue concentration, contrary to plasma concentration, suggests that pharmacological response is more closely related to the latter, indicating that antidematous effect is mediated via the circulating drug rather than a local action in target tissues. This assumption is further discussed from the equivalence point of view. The relevance of this type of study in the case of topical administration of indomethacin is addressed as well. Taking into account the predictive value of the rat paw edema test for clinical efficacy, relationships similar to those observed are to be expected in man. The high correlation existing between plasma concentration of indomethacin and its pharmacological effect justifies the development and use of sustained release preparations in order to improve the outcome of treatment with this nonsteroidal antiinflammatory drug.  相似文献   
992.
An area analysis is presented of deaths in Auckland that were ostensibly avoidable, by appropriate medical intervention and treatment. Mortality data from the National Health Statistics Centre for the period 1977-85 were used in the analysis. The definition of an avoidable death was based on the International Classification of Diseases (ICD) code using established criteria. Eight percent of deaths of people under 65 years of age met the criteria. The basic spatial entity for the analysis is the census area unit and maps of Auckland are presented to show the distribution of avoidable mortality. It is found that there are significant and consistent spatial variations. Three areas with avoidable mortality that is generally higher than elsewhere are apparent: in south Auckland; to the north-west of the central urban sector centered on Grey Lynn; and in the eastern parts of the central sector from Glenn Innes to Onehunga.  相似文献   
993.
994.
The authors describe a method for silicone intubation of a single patent canaliculus associated with a nasolacrimal duct obstruction. Although bicanalicular intubation is always preferable when possible, unicanalicular stenting is necessary when only one canaliculus is patent. A chief advantage of this technique is that the lacrimal stent is inaccessible to the child and thus cannot be accidentally pulled out.  相似文献   
995.
D J Harris  G O Waring  L L Burk 《Ophthalmology》1989,96(11):1597-1607
After penetrating keratoplasty in 52 eyes, keratography refraction and keratometry were used to select appropriate interrupted sutures for removal in order to reduce astigmatism. All eyes had one continuous and either 12 or 16 interrupted nylon sutures. The keratographs were examined retrospectively and separated into six groups on the basis of similar mire patterns. The removal of single sutures associated with three of these patterns reduced astigmatism by the following average amounts: symmetrical oval pattern, 0.44 diopters (D); D-shaped oval pattern, 2.07 D; and focal indentation pattern, 6.60 D. The other three patterns--mildly disrupted mires, incomplete mires, and uninterpretable mires--did not allow quantification of results. Examples of these keratographic patterns are presented and recommendations are made for their use in the management of astigmatism following penetrating keratoplasty.  相似文献   
996.
Effect of a natural flavonoid on gastric mucosal barrier   总被引:2,自引:0,他引:2  
The effects of 3,5,7-trihydroxy-2-(3,4-dihydroxyphenyl)-1-benzopyrylium chloride (IdB 1027) on the rat gastric mucosa were evaluated. IdB 1027 administered intragastrically at doses ranging from 100 to 400 mg/kg inhibited the fall in transmucosal potential difference and the increase in H+ back-diffusion induced by acetylsalicylic acid. Moreover, IdB 1027 at doses of 50 and 200 mg/kg by intragastric route increased the gastric bicarbonate secretion. These results suggest that the gastroprotective activity of IdB 1027 is mediated by an increase in the efficiency of gastric mucosal barrier.  相似文献   
997.
Mycobacterium ulcerans infection in Ashanti region, Ghana   总被引:1,自引:0,他引:1  
We describe a series of 96 cases of Mycobacterium ulcerans infection (Buruli ulcer) from a new endemic focus in the Afram valley, north of Agogo, in Ghana. 63 cases were children under 13 years old. Active treatment by excision and skin grafting necessitates long stays in hospital and repeated procedures. Scarring and contracture are frequent. Eyes and other vital organs may be destroyed. In its endemic foci Buruli ulcer is a serious health burden on rural populations. Research is urgently needed, especially in prevention and non-surgical management.  相似文献   
998.
999.
Diabetic polyneuropathy   总被引:1,自引:0,他引:1  
  相似文献   
1000.
Single parent women   总被引:1,自引:1,他引:0  
Summary While there has been considerable interest in the problems of single parent families, no study has yet determined if the problems are due to increased risk of specific psychiatric disorders in single parents as compared to their married counterparts. Data collected as part of the National Institute of Mental Health Epidemiologic Catchment Area (ECA) Project are presented to compare the psychiatric as well as economic and social functioning of single vs. married parent women ages 18–44, based on a probability sample of members of the greater New Haven community. The major finding between groups is their relative similarity in psychiatric as well as social functioning. The major difference is economic. Single parents, both Black and White, more frequently are less educated and poorer. While many are on welfare, single compared to married female parents are more likely to be working and to report insufficient income to meet their needs. There are no appreciable differences in social contacts, use of health services or six-month prevalence rates of psychiatric disorders including major depression, alcohol or drug abuse. The data suggest that the problems faced by single parent women and their children may be a reflection of poverty and stress in families and not of psychiatric disorders or poor social relations in mothers.  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