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   246540篇
  免费   11290篇
  国内免费   714篇
耳鼻咽喉   2977篇
儿科学   7200篇
妇产科学   6012篇
基础医学   34897篇
口腔科学   6830篇
临床医学   17151篇
内科学   54970篇
皮肤病学   6029篇
神经病学   21926篇
特种医学   6647篇
外国民族医学   7篇
外科学   27437篇
综合类   1384篇
一般理论   96篇
预防医学   28413篇
眼科学   5454篇
药学   18228篇
中国医学   864篇
肿瘤学   12022篇
  2023年   1624篇
  2022年   2330篇
  2021年   5749篇
  2020年   3268篇
  2019年   5376篇
  2018年   9148篇
  2017年   5727篇
  2016年   5322篇
  2015年   5733篇
  2014年   7000篇
  2013年   9955篇
  2012年   16144篇
  2011年   16726篇
  2010年   8714篇
  2009年   6986篇
  2008年   13401篇
  2007年   13966篇
  2006年   13292篇
  2005年   12838篇
  2004年   11879篇
  2003年   11065篇
  2002年   10302篇
  2001年   6000篇
  2000年   6567篇
  1999年   5164篇
  1998年   1471篇
  1997年   1009篇
  1996年   933篇
  1992年   2707篇
  1991年   2374篇
  1990年   2389篇
  1989年   2050篇
  1988年   1935篇
  1987年   1815篇
  1986年   1827篇
  1985年   1688篇
  1984年   1230篇
  1983年   1058篇
  1979年   1339篇
  1978年   912篇
  1975年   989篇
  1974年   1210篇
  1973年   1262篇
  1972年   1196篇
  1971年   1161篇
  1970年   1080篇
  1969年   1147篇
  1968年   1181篇
  1967年   1059篇
  1966年   936篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
The different types of instruments used for monitoring pharmaceutical dissolution testing are presented. Their features and the need for automation are critically discussed. The advantages of flow injection analysis in this respect are illustrated by a variety of examples clearly showing its adaptability to the different problems posed by other automatic and non-automatic alternatives.  相似文献   
72.
Forty patients with chronic hepatitis C (CHC) were included in an open randomized controlled trial of lymphoblastoid α-interferon (L-IFN) versus no treatment. Twenty patients entered each group, and features of therapy and control cases were similar. L-IFN was given in low doses (1.5-4.5 megaunits) for 1 yr. In 16 of 20 patients treated with L-IFN (80%), but in only one of 20 nontreated cases (0.5%; p < 0.001), aminotransferase activities became normal. In four patients there was a reactivation of the disease during treatment after 4, 5, 6, and 8 months with normal aminotransferase levels. A posttherapy reactivation of hepatitis was observed in four additional cases after 1, 1, 1, and 3 months of follow-up. The other eight patients (40%) continued with normal aminotransferase levels for 1.52 ± 0.74 (range, 1-2.1) yr after IFN doses were discontinued. In all treated patients except two nonresponders, but in only one of 20 nontreated cases ( p < 0.001), Knodell's histological activity index decreased. Procollagen type III aminoterminal peptide levels did not change significantly in nontreated and nonresponder patients, diminished slightly in patients with a transient response, and normalized in cases with a long-standing response, suggesting that this serum test may be a reliable marker for monitoring response to IFIN therapy in patients with CHC. Finally, L-IFN treatment induced significant increments in CD4/CD8 index, phytohemagglutinin-induced blastogenesis, and natural killer activity. This study shows that L-IFN diminish inflammatory and fibrogenic activity in most patients with CHC. In 40% of patients treated in this trial, a long-standing remission of the disease was observed.  相似文献   
73.
Patients with morbid obesity present a series of functional and morphologic alterations and require a careful planning for anesthetic management. We report a case of a woman weighing 260 kg who was operated on twice for the treatment of her base condition. In the first operation, general anesthesia was carried out and in the second one, epidural anesthesia was conducted. Main complications included hypoxemia and hypercapnia which persisted during the first week after operation carried out under general anesthesia.  相似文献   
74.
Clusterlike Headache as a First Sign of Brain Metastases of Lung Cancer   总被引:1,自引:0,他引:1  
Dr.  J. Tajti  MD  PhD ; Dr.  K. Sas  MD ; Dr.  D. Szok  MD ; Dr.  E. Vörös  MD ; Dr.  L. Vécsei  MD  DSc 《Headache》1996,36(4):259-260
We report on a patient with clusterlike headache and multiple brain metastases of lung cancer. Initially, cluster headache was suggested clinically by characteristic symptoms without any focal central nervous system signs. However, magnetic resonance imaging demonstrated multiple brain metastases. It is possible that tumor necrosis factor may have played a role in initiating the clusterlike headache.  相似文献   
75.
76.
77.
A total of 186 blood samples from 24 HIV-1 seropositive hemophiliac patients, monitored every four months for 29 months, were investigated for the presence of viral antigen in plasma. In addition, peripheral blood mononuclear cells (PBMC) were cultured for HIV-1, using normal PBMC as a target for replication. Antigenemia was detected in 51 % of the patients and from PBMC in 87.5 % of the patients. The incidence of HIV isolation in asymptomatic patients (42.8 %) was similar to that found in symptomatic patients (51.4 %). Patients with opportunistic infections had a higher incidence of lymphocytic viremia (p<0.05). Plasma viremia was closely associated (p<0.05) with low CD4+ counts and infection progression. The persistence of antigenemia was also a marker of a poor clinical course. In treated patients, plasma viremia was the marker that better correlated with the clinical course, and it did not appear during the first nine months of therapy. Zidovudine doses of >500 mg/day significantly lowered the appearance of antigenemia and lymphocytic viremia (p<0.05).  相似文献   
78.
79.
80.
A series of N-(phosphonoacetyl)-dipeptide derivatives was synthesized for pharmacological testing as antihypertensive compounds. Several of these compounds demonstrated a moderate antihypertensive effect in Wistar spontaneous hypertensive rats (SHR) with p.o. dosing. ACE inhibition by the compounds was studied using ACE from rat plasma and lung. Inhibitors containing esterified C-termini are pro-drugs and showed activity only for plasma ACE.  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