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   24199篇
  免费   1182篇
  国内免费   111篇
耳鼻咽喉   156篇
儿科学   419篇
妇产科学   468篇
基础医学   3234篇
口腔科学   575篇
临床医学   1524篇
内科学   6097篇
皮肤病学   457篇
神经病学   1937篇
特种医学   942篇
外科学   4073篇
综合类   101篇
一般理论   1篇
预防医学   642篇
眼科学   591篇
药学   1701篇
中国医学   66篇
肿瘤学   2508篇
  2023年   126篇
  2022年   252篇
  2021年   401篇
  2020年   276篇
  2019年   314篇
  2018年   409篇
  2017年   327篇
  2016年   430篇
  2015年   445篇
  2014年   563篇
  2013年   721篇
  2012年   1162篇
  2011年   1232篇
  2010年   675篇
  2009年   588篇
  2008年   1130篇
  2007年   1133篇
  2006年   1130篇
  2005年   1114篇
  2004年   1214篇
  2003年   1133篇
  2002年   1149篇
  2001年   864篇
  2000年   871篇
  1999年   802篇
  1998年   333篇
  1997年   255篇
  1996年   228篇
  1995年   198篇
  1994年   208篇
  1993年   177篇
  1992年   563篇
  1991年   499篇
  1990年   490篇
  1989年   488篇
  1988年   429篇
  1987年   358篇
  1986年   358篇
  1985年   354篇
  1984年   253篇
  1983年   190篇
  1982年   86篇
  1979年   167篇
  1978年   124篇
  1977年   118篇
  1974年   89篇
  1972年   92篇
  1971年   97篇
  1968年   96篇
  1967年   90篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
12.
13.
14.
15.
Clinical evaluation of ceftibuten (CETB, 7432-S) was performed in 20 patients with acute bronchitis. They were consisted of 10 males and 10 females aged from 20 to 80 years old. CETB was given orally in daily dose of 300 mg (18 cases) or 600 mg (2 cases) in three divided portions. The duration of administration was 3 to 14 days. Especially they were given for 7 days in 16 cases. A total of 11 strains comprising 4 strains of Staphylococcus aureus, 2 strains of beta-Streptococcus and 1 strain each of Streptococcus pneumoniae, Branhamella catarrhalis, Klebsiella oxytoca, Serratia marcescens, Acinetobacter lwoffii were identified from sputa before administration. All of the above bacteria were eradicated but, in 1 case, a strain of Streptococcus pyogenes appeared after the treatment (eradication ratio = 100%). The clinical efficacy rate was 100%: Responses were excellent in 3 cases and good in 17 cases. There was no side effect and no abnormal changes in laboratory test results. From the avobe results, it is concluded that CETB is effective, safe and useful new oral cephem on acute bronchitis.  相似文献   
16.
We report the results and complications of 103 consecutive patients who underwent percutaneous removal of renal and ureteral stones. The overall clinical success rate was 80.6%. For the recent 33 cases in which UL-arm fluoroscopy was used, however, the success rate was as high as 87.9%, which was considered to be due to easier establishment of percutaneous direct access. The most common complications were bleeding (18.5%), extravasation (15.5%) and fever (9.7%). Four cases with significant bleeding required arteriography, but there were no sign of arteriovenous fistula nor pseudoaneurysms in any cases. To study renal parenchymal damage in the percutaneous procedures, plasma renin activities (PRA) were compared in 54 cases after six months. However, significant elevation of PRA did not occur in any case.  相似文献   
17.
Background: Contraction of airway smooth muscle is regulated by receptor-coupled mechanisms that control the force developed for a given cytosolic calcium concentration (i.e., calcium sensitivity). Halothane antagonizes acetylcholine-induced increases in calcium sensitivity by inhibiting GTP-binding (G)-protein pathways. The authors tested the hypothesis that hexanol, like halothane, inhibits agonist-induced increases in calcium sensitivity in airway smooth muscle by inhibiting G-protein pathways.

Methods: Calcium sensitivity was assessed using [alpha]-toxin-permeabilized canine tracheal smooth muscle. In selected experiments, regulatory myosin light chain phosphorylation was also determined by Western blotting in the presence and absence of 10 mm hexanol and/or 100 [mu]m acetylcholine.

Results: Hexanol (10 mm) and halothane (0.76 mm) attenuated acetylcholine-induced calcium sensitization by decreasing regulatory myosin light chain phosphorylation during receptor stimulation. Hexanol also inhibited increases in calcium sensitivity due to direct stimulation of heterotrimeric G-proteins with tetrafluoroaluminate but not with 3 [mu]m GTP[gamma]S, consistent with prior results obtained with halothane. In contrast, in the absence of receptor stimulation, both compounds produced a small increase in calcium sensitivity by a G-protein-mediated increase in regulatory myosin light chain phosphorylation that was not affected by pertussis toxin treatment.  相似文献   

18.
A 65-year-old woman with diabetes mellitus and chronic otitis media developed headache, fever, and hoarseness, all of which did not responded to the oral antibiotics. As stiff neck and lower cranial nerve palsies appeared, bacterial meningitis was suspected. Neurological examination revealed the right hearing disturbance, right recurrent laryngeal nerve palsy, left sternocleidomastoid muscle atrophy and bilateral tongue atrophy. The CSF examination revealed mild pleocytosis and elevated protein, but no bacterial organism was cultured from the CSF. CT scans showed bilateral mastoiditis, and the right mastoid process and a posterior part of the petrous bone were eroded, indicating the exposed bony structures to the posterior fossa. MRI scans demonstrated the thickening of the dura mater of the posterior fossa and the right cerebellar tentorium. This is a rare example of bacterial pachymeningitis of the posterior fossa, the clinical symptoms and MRI findings of which resolved solely by antimicrobial agents without corticosteroid.  相似文献   
19.
After removal of intraductal stones, a 10‐Fr or 7‐Fr pancreatic stent was placed in 16 patients with upstream ductal dilation proximal to a stricture of the main pancreatic duct. Stents were removed after a mean duration of 52.5 days. Nine patients underwent repeated stenting. About one year after removal of the initial stent, when the remaining upstream ductal dilation was found on follow‐up pancreatograms, the next stent was replaced. Repeated stenting improved outflow of pancreatic juice more effectively than one‐time stenting. Correlation between long‐term pain relief without recurrence of intraductal stones and reduction of duct diameter was also shown. Stent occlusion was observed in 14 of 30 stents. Stent occlusion was frequently associated with recurrence of pancreatitis and intraductal stones, and was also associated with morphologic changes in the pancreatic ductal system. Although there were no significant differences between stent patency of the initial stents and that of the next stents, stent patency of 10‐Fr stents was superior to that of 7‐Fr stents. 10‐Fr stents should be removed within 8 weeks and 7‐Fr stents should be removed within 4 weeks for the prevention of stent occlusion. Repeated stenting with short‐term stenting is therefore considered a safe and effective protocol of endoscopic pancreatic stenting.  相似文献   
20.
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