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   1989篇
  免费   108篇
  国内免费   5篇
耳鼻咽喉   2篇
儿科学   50篇
妇产科学   31篇
基础医学   641篇
口腔科学   64篇
临床医学   164篇
内科学   263篇
皮肤病学   69篇
神经病学   161篇
特种医学   113篇
外科学   166篇
综合类   18篇
一般理论   2篇
预防医学   82篇
眼科学   6篇
药学   156篇
中国医学   1篇
肿瘤学   113篇
  2023年   12篇
  2021年   21篇
  2020年   27篇
  2019年   29篇
  2018年   34篇
  2017年   32篇
  2016年   26篇
  2015年   38篇
  2014年   40篇
  2013年   72篇
  2012年   88篇
  2011年   100篇
  2010年   52篇
  2009年   44篇
  2008年   83篇
  2007年   77篇
  2006年   83篇
  2005年   78篇
  2004年   109篇
  2003年   95篇
  2002年   72篇
  2001年   31篇
  2000年   29篇
  1999年   27篇
  1998年   18篇
  1997年   12篇
  1992年   21篇
  1991年   12篇
  1990年   17篇
  1989年   14篇
  1988年   14篇
  1972年   15篇
  1943年   16篇
  1942年   30篇
  1941年   30篇
  1940年   38篇
  1939年   14篇
  1938年   18篇
  1937年   23篇
  1936年   27篇
  1935年   18篇
  1934年   35篇
  1933年   19篇
  1932年   12篇
  1931年   14篇
  1929年   16篇
  1928年   29篇
  1927年   29篇
  1926年   35篇
  1925年   38篇
排序方式: 共有2102条查询结果,搜索用时 15 毫秒
1.
Die Anaesthesiologie - Die Anlage einer Magensonde im OP oder auf einer Intensivstation (ITS) stellt eine alltäglich durchgeführte Prozedur dar. Obwohl die Sonde häufig durch...  相似文献   
2.
Phenylephrine is widely used as an ophthalmic drug. However, there are only very few reports on allergic contact dermatitis induced by phenylephrine. In addition, little is known on cross reactivity patterns between the sympathomimetics phenylephrine, epinephrine and ephedrine which share a similar chemical structure. We report on a man who developed allergic contact dermatitis to Neosynerphin POS eyedrops containing phenylephrine hydrochloride. Cross reactivity between phenylephrine, epinephrine and ephedrine was studied by patch testing. Patch tests were performed with the European standard, an ophthalmics and preservatives series, Neosynerphin POS eyedrops, phenylephrine hydrochloride 10% aq., epinephrine and ephedrine (both 1.0 % aq.). Test sites were read after 48, 72 and 168 hours according to the recommendations of the ICDRG. Neosynerphin POS and phenylephrine hydrochloride 10 % aq. gave positive reactions, whereas epinephrine and ephedrine tested negative. Although phenylephrine is an epinephrine analog delayed type hypersensitivity to phenylephrine did not result in cross reactivity with chemically related epinephrine and ephedrine.  相似文献   
3.
Zeitschriften     
Ohne Zusammenfassung  相似文献   
4.
5.
Migraine is considered to be a functional neurological disorder. In classical migraine (headache associated with prodromal visual field disturbances) and migraine accompagnée (headache associated with transient neurological symptoms), disturbances of cerebral blood flow and amine metabolism are thought to be pathogenetic factors. However, conventional methods of neuroimaging (CAT, NMR) usually do not yield any pathological findings in patients. Since 123I-iodoamphetamine (123I-IMP) crosses the intact blood brain barrier, 123I-IMP-SPECT is used for the assessment of cerebral perfusion in various neurological diseases, including functional disorders. 123I-IMP-SPECT was performed on 5 patients with classical migraine and 18 patients with migraine accompagnée. At the time of investigation, all patients were symptom-free. Cerebral blood flow was decreased in all patients with migraine accompagnée, and often corresponded to the site of headache as well as to the topography of transient neurological symptoms. This reduction was most obvious in a patient with persisting neurological symptoms. Most patients with classical migraine, however, did not show any alteration of cerebral perfusion. It appears that migraine--and in particular migraine accompagnée--is characterized by a permanent alteration not only of cerebral blood flow but also of neuronal activity. Migraine attacks may occur in connection with exacerbations of preexisting metabolic alterations.  相似文献   
6.
7.
Studies in animals suggest that calcium channel blockers may influence gallbladder contraction. In order to study possible actions in man we examined by ultrasonography the effects of two dihydropyridine derivatives, i.e. nifedipine (20 mg p. o.) and BAY 1 8201 (100 mg p.o.) on ceruletide induced human gallbladder contraction in 9 healthy male volunteers in a randomized, double-blind, three fold crossover study (latin square design). Blood samples for the measurement of plasma drug concentrations were drawn before and at regular intervals up to 8 h after drug ingestion. Ceruletide decreased gallbladder volumes by 52.1 +/- 8.2% (mean +/- 1 SEM) after nifedipine, 53.1 +/- 8.1% after BAY 1 8201 and by 59.3 +/- 10.1% after placebo (NS). Peak plasma concentrations of 53.7 x/: 2.3 ng/ml (geometric mean x/: geometric standard deviation) and of 35.5 x/: 1.5 ng/ml were reached after oral application of nifedipine and BAY 1 8201, respectively. We conclude that human gallbladder contraction in response to ceruletide is not markedly influenced by dihydropyridine derivates in the dosages used in this study. The results reported here stress the importance of calcium released from intracellular stores for the contractility of smooth muscle in the human gallbladder.  相似文献   
8.
9.
10.
Development of interventions to prevent accidental occupational fatalities requires the prior identification of those at risk and the circumstances surrounding the injuries. A survey of unintentional farm fatalities was conducted using medical examiner reports (RIME) and death certificates (MECD) to identify deaths due to agricultural occupational injuries in North Carolina from 1984 through 1988. Of 393 cases, 123 met the criteria "farmer" listed as occupation on the RIME/MECD and/or "victim" in a rural area performing a farming task when injured. A second aim of this study was to use an existing data base to achieve maximum accuracy in identifying true cases of work-related farm fatalities.
A fatality rate of 41/100,000 agricultural workers was found; the National Institutes of Occupational Safety and Health's National Traumatic Occupational Fatality study criteria would have identified only 57 percent of these. Victims were characterized as middle age (53 years), white (76%), male (100%), full-time farmers (65%). Injury occurred during harvest season on Monday or Tuesday (47%) between 2 and 6 p.m. (54%). Death was pronounced at the scene (74%), with probable cause listed as tractor (62%). Injury location and land elevation were also related, with the mountain region having twice the fatality rate as the coastal plains region.  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