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   17722篇
  免费   1316篇
  国内免费   260篇
耳鼻咽喉   205篇
儿科学   377篇
妇产科学   572篇
基础医学   2253篇
口腔科学   806篇
临床医学   1650篇
内科学   3475篇
皮肤病学   284篇
神经病学   1897篇
特种医学   570篇
外科学   2178篇
综合类   912篇
一般理论   2篇
预防医学   1233篇
眼科学   462篇
药学   1222篇
  4篇
中国医学   183篇
肿瘤学   1013篇
  2023年   178篇
  2022年   310篇
  2021年   502篇
  2020年   321篇
  2019年   389篇
  2018年   416篇
  2017年   386篇
  2016年   390篇
  2015年   533篇
  2014年   563篇
  2013年   723篇
  2012年   948篇
  2011年   1106篇
  2010年   745篇
  2009年   665篇
  2008年   880篇
  2007年   921篇
  2006年   848篇
  2005年   788篇
  2004年   712篇
  2003年   725篇
  2002年   668篇
  2001年   502篇
  2000年   460篇
  1999年   411篇
  1998年   205篇
  1997年   178篇
  1996年   145篇
  1995年   128篇
  1994年   147篇
  1993年   121篇
  1992年   239篇
  1991年   236篇
  1990年   209篇
  1989年   202篇
  1988年   198篇
  1987年   161篇
  1986年   164篇
  1985年   161篇
  1984年   111篇
  1983年   114篇
  1982年   73篇
  1980年   63篇
  1979年   87篇
  1978年   81篇
  1977年   69篇
  1975年   96篇
  1974年   71篇
  1973年   64篇
  1972年   68篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Alcohol consumption and glycosuria were found to be associated (p < 0.001) in a population of 6571 salaried employees who underwent a systematic examination. The prevalence of glycosuria was found to range from 1.3% among 2609 non-drinkers to 5% among 816 heavy drinkers (six glasses or more of alcoholic beverage daily). This association was still significant after adjustement for age, sex and body mass index. Similarly, a positive association was observed between fasting glycemia and alcoholic intake in a subgroup of 998 subjects when such a result was available (p < 0.05).  相似文献   
42.
43.
J. Lang 《Acta neurochirurgica》1994,130(1-4):144-146
  相似文献   
44.
Four human clonogenic malignant lymphoid cell lines (CEM, Su-DHL-4, Li-A, and Raji) as well as normal human bone marrow stem cell progenitor cells were investigated for clonal in vitro growth before and after incubation with the ether lipid ET-18-OCH3 for various times (1, 4, and 18 h) and at increasing concentrations of the drug (25, 50, 75, and 100 micrograms/ml). The clonal growth of the malignant lymphoid cell lines was inversely correlated with concentrations and times of drug incubation. The antineoplastic effect of ET-18-OCH3 was further amplified by subsequent cryopreservation. In a situation of 4-h exposure to less than or equal to 50 micrograms/ml ET-18-OCH3 and subsequent cryopreservation, in which greater than 50% of the normal human bone marrow progenitor cells survived, 1-3 logs of the malignant lymphoblastoid cells were killed, indicating a potential value of this drug for bone marrow purging in lymphoid malignancy. In order to simulate the situation of autologous bone marrow transplantation (ABMT) in complete remission of the disease, we contaminated normal human bone marrow cells with malignant CEM or Su-DHL-4 lymphoid cells at a ratio of 100:1. Results show that 4 h of incubation with 75 micrograms/ml ET-18-OCH3 and subsequent cryopreservation can eliminate 2-3 logs of clonogenic cells of the malignant lymphoblastoid cell lines under conditions that allow recovery of greater than 50% of the normal human hematopoietic progenitors.  相似文献   
45.
Zusammenfassung Grundlagen Die pulmonale Thrombendarterektomie stellt eine effektive Therapie zur Behandlung von Patienten mit chronisch thromboembolischer pulmonalar Hypertonie dar. Wir berichten über unsere Erfahrungen mit dieser Operationstechnik bei den ersten 9 Patienten. Methodik Zwischen 1992 und Oktober 1994 wurde bei 9 Patienten eine pulmonale Thrombendarterektomie durchgeführt. über eine mediane Sternotomie wurden die Pulmonalarterien beider Seiten bis in ihre subsegmentalen Aufzweigungen im Sinne einer echten Endarterektomie vom organisierten thromboembolischen Material befreit. Zumeist waren Perioden des totalen Kreislaufstillstandes in tiefer Hypothermie notwendig, wobei diese zunehmend verkürzt werden konnten und 3 Patienten vollst?ndig ohne Kreislaufstopp operiert wurden. Ergebnisse Die perioperative Mortalit?t betrug 11%, wobei der 1. Patient am 14. postoperativen Tag an den Folgen eines Reperfusions?dems verstarb. Alle anderen Patienten sind 4 bis 22 Monate (im Mittel 13 Monate) nach dem Eingriff am Leben und zeigen eine Hochsignifikante Verbesserung ihrer h?modynamischen Situation (mean PAP pr?operativ: 62 mm Hg, postoperativ: 30 mm Hg p<0,001; Cardiac Index pr?operativ: 2,1 1/min/m2, postoperativ: 3,6 l/min/m2 p=0,001). W?hrend pr?operativ alle Patienten in NYHA-Klasse III oder IV waren, sind die 8 überlebenden jetzt alle in Klasse I oder II. Schlu?folgerungen Die pulmonale Thrombendarterektomie bietet eine erfolgreiche Therapiem?glichkeit für Patienten mit chronisch thromboembolischer pulmonaler Hypertonie mit einer in Anbetracht fehlender konservativer Altermativen akzeptablen Mortalit?t und ausgezeichneten funktionellen Langzeitergebnissen.   相似文献   
46.
Food policy and public health.   总被引:1,自引:0,他引:1  
T Lang 《Public health》1992,106(2):91-125
  相似文献   
47.
The results from a cohort study on the incidence of cancer and the mortality in a cohort of 2391 male workers producing magnesium metal are presented. The study population was restricted to employees with more than one year of work experience in the study plant between 1951 and 1974 and the cohort was observed from 1953 to 1984. Altogether 152 new cases of cancer were observed versus 132.6 expected. Six cases of cancer of the lip were found against 2.3 expected, 21 of stomach cancer against 12.8 expected, and 32 of lung cancer against 18.2 expected. A possible causal relation between exposure to factors in the work environment and the development of cancer is discussed.  相似文献   
48.
Summary In a 66-year-old woman signs and symptoms of bilateral opercular syndrome (Foix-Chavany-Marie-syndrome) developed progressively over a period of more than 10 years. Facio-linguo-velo-pharyngeo-masticatory diplegia with automatic-vol-untary dissociation was accompanied by motor aphasia and oral apraxia leading to a state of almost complete anarthria. Although it initially resembled the anterior biopercular syndrome there are also features indicating involvement of the posterior opercula. Although the aetiology remains obscure without pathological data, a bilateral focal brain atrophy is assumed. This is probably the first case documented by MRI and SPECT.Supported by the Hirnliga, Heidelberg, Federal Republic of Germany  相似文献   
49.
Local tissue renin-angiotensin systems have recently been discovered in various organs, and evidence is accumulating that inhibition of these local renin-angiotensin systems may contribute to the actions of converting enzyme (CE) inhibitors. Measurements of CE activity and angiotensin II concentrations revealed that after oral administration of CE inhibitors, CE was inhibited not only in lung vascular endothelium and blood, but also in the heart, kidney, vascular wall, brain and other organs. The functional significance of tissue CE inhibition is suggested first by the antihypertensive effect of brain CE inhibition in spontaneously hypertensive rats, second by the concomitant persistence of blood pressure decrease and CE inhibition in vascular wall and kidney after long-term oral CE inhibitor treatment and third by ex vivo experiments demonstrating marked effects of oral CE inhibitor pretreatment on cardiac function in isolated rat hearts. Local inhibition of tissue renin-angiotensin systems may be an important factor involved in the beneficial effects of CE inhibitors in such cardiovascular diseases as arterial hypertension, congestive heart failure and cardiac arrhythmias.  相似文献   
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