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   2473篇
  免费   179篇
  国内免费   16篇
耳鼻咽喉   61篇
儿科学   98篇
妇产科学   64篇
基础医学   265篇
口腔科学   57篇
临床医学   253篇
内科学   732篇
皮肤病学   25篇
神经病学   105篇
特种医学   70篇
外科学   387篇
综合类   46篇
预防医学   203篇
眼科学   46篇
药学   117篇
中国医学   1篇
肿瘤学   138篇
  2023年   34篇
  2022年   67篇
  2021年   103篇
  2020年   72篇
  2019年   68篇
  2018年   101篇
  2017年   71篇
  2016年   73篇
  2015年   80篇
  2014年   86篇
  2013年   103篇
  2012年   203篇
  2011年   189篇
  2010年   129篇
  2009年   127篇
  2008年   167篇
  2007年   169篇
  2006年   143篇
  2005年   137篇
  2004年   124篇
  2003年   90篇
  2002年   93篇
  2001年   40篇
  2000年   26篇
  1999年   24篇
  1998年   16篇
  1997年   9篇
  1996年   7篇
  1995年   13篇
  1994年   6篇
  1993年   3篇
  1992年   11篇
  1991年   7篇
  1990年   9篇
  1989年   4篇
  1988年   6篇
  1987年   11篇
  1986年   4篇
  1985年   6篇
  1983年   4篇
  1982年   2篇
  1980年   3篇
  1978年   2篇
  1976年   2篇
  1971年   2篇
  1970年   2篇
  1967年   6篇
  1966年   4篇
  1965年   1篇
  1960年   1篇
排序方式: 共有2668条查询结果,搜索用时 15 毫秒
21.
We report the cytological and clinical findings of 16 fine-needle aspirates (FNAs) performed on recurrent (n = 6) and metastatic (n = 10) mixed mesodermal tumors (MMMTs). The median interval between the primary diagnosis and FNA was 16 mo. Primary sites were the endometrium (n = 11), the ovary (n = 3), the cervix (n = 1), and pelvic soft tissue (n = 1). Primary tumors showed carcinoma with homologous mesenchymal components in 13 cases and focal heterologous elements in three (two chondrosarcomas and one rhabdomyosarcoma). The FNAs showed carcinoma in all 16 cases, with adenocarcinoma differentiation in three, Mesenchymal elements were identified in aspirates of three recurrent and two metastatic lesions. They were all homologous. No heterologous mesenchymal elements were identified in the aspirates. We conclude that mesenchymal components in FNAs of MMMTs are less likely to be seen in metastatic lesions, and that heterologous mesenchymal components are rarely seen in these aspirates even in recurrent disease. These findings confirm that the epithelial component is responsible for the malignant behavior of MMMTs, and suggest that these lesions may need to be classified as sarcomatoid carcinomas rather than true carcinosarcomas. Diagn Cytopathol 1994;11:328–332. © 1994 Wiley-Liss, Inc.  相似文献   
22.
This study was designed to evaluate the potential effects of acute and chronic daily oral doses of lansoprazole (60 mg) on the disposition of antipyrine, an almost completely metabolized low hepatic extraction compound, and indocyanine green, a hepatically secreted compound with high extraction ratio. The study utilized a randomized, placebo-controlled, double-blind, two-period crossover design. Sixteen of 18 subjects completed all phases of the study. Both antipyrine (10 mg kg(minus sign1)) and indocyanine green (0.5 mg kg(minus sign1)) were administered as single intravenous bolus doses on Days 1 and 7 of lansoprazole or placebo dosing. Acute exposure to lansoprazole had no statistically significant effects on the plasma pharmacokinetics of indocyanine green or antipyrine. After the seventh dose, there was a small but statistically significant reductions in indocyanine green total body clearance (CL), and elimination rate constant of 10.6% and 8%, respectively. Additionally, a small statistically significant reduction (8.6%) in antipyrine volume of distribution was detected. No other plasma antipyrine pharmacokinetic parameters were changed with concomitant lansoprazole administration. About a 12% increase in the recovery of one of the major antipyrine urine metabolites (NORA) was detected. Overall, this study demonstrates little or no effect of lansoprazole on the pharmacokinetics of antipyrine and indocyanine green.  相似文献   
23.
Summary The aim of this study was to investigate the effects of an infusion of angiotensin II (50 ng/kg/min) on furosemide pharmacodynamics and kinetics in the conscious rabbit. The protocol included a 90-minute phase to estimate the glomerular filtration rate and the renal plasma flow, followed by a 60-minute phase where 5 mg/kg (n=12) or 10 mg/kg (n=9) of furosemide were administered. During the pre-furosemide phase, compared to control rabbits, angiotensin II increased natriuresis and diuresis. In the presence of angiotensin II, the furosemide-induced natriuresis decreased, that is, it was 174±14 versus 95±25 µmol/min (p<0.05) and 187±17 versus 89±21 µmol/min (p<0.05) for the 5 and the 10 mg/kg doses, respectively. The infusion of angiotensin II decreased renal plasma flow without modifying the glomerular filtration rate, thus the filtration fraction was increased. Angiotensin II increased the area under the furosemide plasma concentrations as a function of time since it decreased its systemic clearance. However, furosemide urinary excretion rate was not altered and its renal clearance decreased slightly without reaching statistical significance. It is concluded that angiotensin II decreases the response to furosemide and the mechanism underlying this effect is related to the pharmacodynamics rather than the kinetics of the diuretic.  相似文献   
24.
25.
26.
27.
28.
Objectives: (1) To assess the ability of flow cytometric immunophenotyping to detect and quantitate eosinophils in patients with eosinophilic otitis media (EOM). (2) to evaluate the association of EOM to bronchial asthma.

Methods: Twenty-one patients with chronic otorrhea or middle ear effusion (MEE) were included in this prospective cohort study. Group I composed of 10 patients (14 ears) and associated to bronchial asthma. Group II included 11 patients (11 ears) without bronchial asthma. Samples of MEE were sent for flow cytometric analysis at initial presentation. Patients with positive eosinophils on flow cytometric immunophenotyping were analyzed after one-month course of dexamethasone eardrops.

Results: EOM was diagnosed in all patients of group I and in three patients of group II. The mean eosinophils percentage was 43.5% and 14.2% for group I and group II, respectively (p?=?.006). Those patients showed a significant response to dexamethasone eardrops, both on clinical examination and on flow cytometric analysis with a decrease in eosinophil levels post-treatment. However, this improvement was temporary and symptoms recurred after treatment cessation. Bronchial asthma was not associated to all patients with EOM.

Conclusion: Diagnosis of EOM remained mostly clinical; flow cytometry immunophenotyping of MEE may be helpful as an additional tool in diagnosis and monitoring the response to treatment, particularly in non-asthmatic patients.  相似文献   
29.
Maternal infection/inflammation represents one of the most important factors involved in the etiology of brain injury in newborns. We investigated the modulating effect of prenatal melatonin on the neonatal brain inflammation process resulting from maternal intraperitoneal (i.p.) lipopolysaccharide (LPS) injections. LPS (300 μg/kg) was administered to pregnant rats at gestational days 19 and 20. Melatonin (5 mg/kg) was administered i.p. at the same time as LPS. Melatonin counteracted the LPS sensitization to a second ibotenate‐induced excitotoxic insult performed on postnatal day (PND) 4. As melatonin succeeded in reducing microglial activation in neonatal brain at PND1, pathways previously implicated in brain inflammation regulation, such as endoplasmic reticulum (ER) stress, autophagy and silent information regulator 1 (SIRT1), a melatonin target, were assessed at the same time‐point in our experimental groups. Results showed that maternal LPS administrations resulted in an increase in CHOP and Hsp70 protein expression and eIF2α phosphorylation, indicative of activation of the unfolded protein response consequent to ER stress, and a slighter decrease in the autophagy process, determined by reduced lipidated LC3 and increased p62 expression. LPS‐induced inflammation also reduced brain SIRT1 expression and affected the expression of miR‐34a, miR146a, and miR‐126. All these effects were blocked by melatonin. Cleaved‐caspase‐3 apoptosis pathway did not seem to be implicated in the noxious effect of LPS on the PND1 brain. We conclude that melatonin is effective in reducing maternal LPS‐induced neonatal inflammation and related brain injury. Its role as a prophylactic/therapeutic drug deserves to be investigated by clinical studies.  相似文献   
30.
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