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   1542篇
  免费   173篇
  国内免费   31篇
耳鼻咽喉   24篇
儿科学   35篇
妇产科学   14篇
基础医学   162篇
口腔科学   52篇
临床医学   131篇
内科学   376篇
皮肤病学   13篇
神经病学   120篇
特种医学   181篇
外科学   213篇
综合类   37篇
一般理论   1篇
预防医学   173篇
眼科学   11篇
药学   134篇
中国医学   1篇
肿瘤学   68篇
  2021年   20篇
  2019年   16篇
  2018年   28篇
  2017年   22篇
  2016年   19篇
  2015年   28篇
  2014年   43篇
  2013年   53篇
  2012年   57篇
  2011年   64篇
  2010年   34篇
  2009年   32篇
  2008年   58篇
  2007年   64篇
  2006年   55篇
  2005年   56篇
  2004年   46篇
  2003年   45篇
  2002年   47篇
  2001年   40篇
  2000年   40篇
  1999年   45篇
  1998年   37篇
  1997年   35篇
  1996年   29篇
  1995年   14篇
  1994年   36篇
  1993年   32篇
  1992年   31篇
  1991年   34篇
  1990年   36篇
  1989年   54篇
  1988年   41篇
  1987年   38篇
  1986年   43篇
  1985年   37篇
  1984年   22篇
  1983年   19篇
  1982年   21篇
  1981年   23篇
  1979年   18篇
  1978年   16篇
  1977年   15篇
  1975年   17篇
  1974年   15篇
  1973年   14篇
  1972年   15篇
  1970年   13篇
  1969年   15篇
  1966年   13篇
排序方式: 共有1746条查询结果,搜索用时 15 毫秒
1.
2.
3.
Since the syndrome of primary hyperaldosteronism was described by Jerome Conn in 1955, over 300 patients with this disorder have been identified in the medical centers of Vanderbilt University and the University of Michigan. The most frequent cause of this endocrinopathy has been a solitary adenoma of the adrenal cortex (72%); bilateral adrenocortical hyperplasia has been the cause of primary hyperaldosteronism in 27% of cases; less frequently, the cause has been multiple and/or bilateral adenomas (1%). During the last 4 years in these 2 medical centers, we have encountered 3 patients who have had biochemically proven primary hyperaldosteronism due to adrenocortical carcinoma. Each of these unusual cases is summarized with review of the recent literature.
Resumen Desde la descripción del síndrome de hiperaldosteronismo primario por Jeremo Conn en 1955, más de 300 pacientes con esta entidad han sido identificados en nuestros 2 centros médicos, la Universidad de Vanderbilt (Nashville) y la Universidad de Michigan (Ann Arbor). La causa más frecuente de esta endocrinopatía ha sido el adenoma solitario de la corteza suprarrenal (72%); la hiperplasia adrenocortical bilateral ha sido la causa del hiperaldosteronismo primario en 27% de los casos; con menor frecuencia se han presentado los adenomas multiples y/o bilaterales (1%). En los 4 últimos años hemos encontrado 3 pacientes con hiperaldosteronismo primario comprobado bioquímicamente producido por carcinoma adrenocortical. Se presenta cada uno de estos casos poco usuales junto con una revisión de la literatura reciente.

Résumé Depuis que le syndrome d'hyperaldostéronisme primitif a été décrit par Jerôme Conn en 1955 plus de 300 sujets qui en étaient victimes ont été identifiés à la Vanderbilt University de Nashville et à l'University of Michigan de Ann Arbor. La cause la plus fréquente de cette endocrinopathie répond à un adénome solitaire de la cortico-surrénale (72%) alors que l'hyperplasie corticale des 2 surrénales est plus rarement à son origine (27%), les adénomes multiples et/ou bilatéraux étant rarissimes (1%). Au cours des 4 dernières années 3 cas d'hyperaldosteronisme dû à un cancer de la cortico-surrénale ont été observés dans les 2 centres. Chacun de ces cas exceptionnels est exposé cependant que la littérature récente concernant l'hyperalderosteronisme est analysée.


Presented at the International Association of Endocrine Surgeons in Paris, September 1985.  相似文献   
4.
Liver transplantation is currently the only effective therapy for patients with fulminant hepatic failure. The availability of an artificial liver could bridge these patients through the relatively brief crisis period and allow their own livers to regenerate, providing a more favorable outcome and sparing the trauma and expense of transplant. We have developed a device consisting of a highly differentiated human liver cell line cultured in a hollow fiber cartridge. This device is capable of supporting dogs with acetaminophen-induced fulminant hepatic failure for a period long enough for their own livers to resume function. Even though liver function tests such as albumin and prothrombin time became extremely abnormal during the course of the experiment, the dogs did not become encephalopathic. Two of the three treated animals recovered sufficient liver function after 42 to 48 hr of treatment that they could be disconnected from the device, and they survived the experiment. Histological results and serum ALT levels suggest that the device affected the course of the disease in two animals, allowing recovery of hepatocytes that would otherwise have lysed. In the third animal, regenerative nodules demonstrated that, even in the presence of severe liver injury, the device was capable of supporting total liver function.  相似文献   
5.
We reviewed data from 48 patients after anterior temporal lobe resection for medically intractable epilepsy. All had ictal electro-encephalographic (EEG) evidence of unilateral temporal lobe onset. Depth electrodes were used in 19 patients. Successful surgical outcome correlated significantly with factors that suggested a temporal lobe focus, particularly in the interictal scalp EEG. The most successful outcome occurred in patients with well-localized unilateral interictal temporal spikes (100% improved). The group with well-localized bilateral temporal spikes also did well (76% improved). Patients with extratemporal spread of the interictal spike on scalp EEG, either unilaterally or bilaterally, did less well. Only one third improved, despite extensive extracranial and intracranial monitoring, when indicated. The interictal scalp EEG may be the only EEG necessary for the presurgical evaluation of selected patients with intractable temporal lobe epilepsy.  相似文献   
6.
以18-甲基-17β-羟基-17α-乙炔基-雌甾-4-烯-3-酮(18-甲基炔诺酮),17β-羟基-17α-乙缺基-雌甾-4-烯-3-酮(炔诺酮),17β-羟基-17α-乙炔基-雄甾-4-烯-3-酮(妊娠素)和17a-羟基孕甾-4-烯-3,20二酮(17α-羟基黄体酮)为原料,经NaBH,还原、脱水、双键转位和酯化等反应合成一系列3,5-甾二烯化合物,用1HNMR和MS证明了它们的结构。动物筛选结果表明,17β-丙酰氧基-17α-乙炔基-雌甾-3,5-二烯(IVb2有明显的抗早孕活性。中断早期妊娠的作用似与其雌激素活性有关。  相似文献   
7.
Bile duct calculi in patients with primary sclerosing cholangitis   总被引:1,自引:0,他引:1  
  相似文献   
8.
9.
Four activity participation variables (clubs, sports, church, and parties); two indices of "risk-taking" (preference for risk-taking, getting into trouble at school); three demographic variables (sex, ethnic group, socioeconomic status); and two drug use variables (trial of cigarettes and alcohol) were examined as correlates and prospective predictors of trial of smokeless tobacco in two cohorts of seventh graders in urban Los Angeles. The data were analyzed separately for males and females. Cross-sectional logistic regression analyses indicated that correlates of trying smokeless tobacco among the seventh-grade cohorts or among these same cohorts in the eighth grade (considering those persons who had not tried smokeless tobacco in seventh grade) generally included being white, trying cigarettes, risk-taking, and attending parties. Prospective logistic regression analyses with data from subjects who had not tried smokeless tobacco in the seventh grade indicated that predictors of subsequent trial of it generally included only being white and having tried cigarettes. Sports participation predicted onset only in one cohort of female subjects but not in males. Some activities that have been proposed as being predictive of smokeless tobacco use (e.g., sports participation) are generally irrelevant for a large sample of young adolescents in urban Los Angeles. White male cigarette smokers, regardless of the activities they have engaged in, are most likely to try smokeless tobacco.  相似文献   
10.
Reagents which affect the cytosolic concentrations of protons and sodium ions markedly affect the degranulation process of mast cells. The proton-sodium exchanging ionophore, monensin, is found to cause noncytolytic dose dependent serotonin release from the rat leukemic basophils (line RBL-2H3). Its half maximal dose of ca. 2 microM leads to secretion of ca. 20% of these cells' serotonin content. Monensin induced serotonin secretion increases with external pH and decreases upon lowering external sodium ion concentrations, yet is independent on external calcium. Monitoring cytosolic pH and free Ca2+ concentrations with BCECF and quin2, respectively, shows that a rise in pHi and [Ca2+]i is caused by the ionophore. Amiloride, the blocker of cellular Na+/H+ antiporter, is found to be an effective inhibitor of antigen or monensin induced serotonin release. However, it does not by itself cause secretion. In contrast, ouabain, which inhibits the cellular Na+/K+ ATPase, does induce secretion. Cellular levels of pH, Na+ and Ca2+ ions are evidently linked and involve a manifold of activities. Though exchanging protons for sodium seems to be effective in causing mediator release, the present results do not provide sufficient support for proton/sodium ions having a second messenger role in the immunologically induced mediator release.  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