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   580篇
  免费   32篇
  国内免费   20篇
耳鼻咽喉   2篇
儿科学   13篇
妇产科学   3篇
基础医学   119篇
口腔科学   13篇
临床医学   43篇
内科学   92篇
皮肤病学   5篇
神经病学   16篇
特种医学   220篇
外科学   25篇
综合类   3篇
预防医学   8篇
眼科学   1篇
药学   60篇
肿瘤学   9篇
  2022年   5篇
  2021年   6篇
  2020年   7篇
  2019年   5篇
  2018年   8篇
  2017年   5篇
  2016年   15篇
  2015年   22篇
  2014年   22篇
  2013年   13篇
  2012年   20篇
  2011年   14篇
  2010年   17篇
  2009年   21篇
  2008年   28篇
  2007年   41篇
  2006年   22篇
  2005年   21篇
  2004年   17篇
  2003年   13篇
  2002年   22篇
  2001年   22篇
  2000年   15篇
  1999年   16篇
  1998年   28篇
  1997年   18篇
  1996年   7篇
  1995年   11篇
  1994年   11篇
  1993年   12篇
  1992年   4篇
  1991年   14篇
  1990年   8篇
  1989年   15篇
  1988年   19篇
  1987年   10篇
  1986年   8篇
  1985年   9篇
  1984年   7篇
  1983年   4篇
  1982年   4篇
  1980年   5篇
  1978年   5篇
  1977年   4篇
  1976年   7篇
  1975年   7篇
  1969年   2篇
  1968年   2篇
  1966年   2篇
  1964年   2篇
排序方式: 共有632条查询结果,搜索用时 171 毫秒
1.
Intratemporal vascular tumors: detection with CT and MR imaging   总被引:1,自引:0,他引:1  
The diagnostic contributions of computed tomography (CT) and magnetic resonance (MR) imaging were compared in 12 patients with benign intratemporal vascular tumors (hemangioma or vascular malformation). The tumors included six in the internal acoustic canal and six in the geniculate ganglion region. Clinical and histologic correlations were made. Two of the six patients with tumors in the internal acoustic canal underwent CT, and both required gas cisternography to show the tumor. Five patients in that group underwent MR imaging, and all five studies showed the tumor. All six patients with geniculate ganglion tumors underwent CT. Results in one study were questionable, and five showed the tumor. Five patients in this group underwent MR imaging, but the MR findings were positive in only two cases. MR imaging should therefore be performed before CT in the evaluation of facial nerve dysfunction, as it demonstrated all tumors in the internal acoustic canal and some in the geniculate ganglion region. If MR findings are negative, CT should then be performed to rule out a possible geniculate ganglion lesion.  相似文献   
2.
Abstract Several previous studies have evaluated the effects of 0.12% chlorhexidine digluconate (ChD) mouthrinses on plaque and gingival inflammation. However, previously, none have been based in general dental practices. The aim of this study was to evaluate the potential to conduct controlled periodontal clinical trials in co-operation with general dental practitioners (gdps). The project took place in 5 general dental practices in the South of England. 121 healthy subjects (24 at 4 sites and 25 at the 5th). aged 18-65 years, mean 35 ± 12) years participated in a double-blind, randomised study during which they received full mouth assessments for plaque and gingival bleeding at baseline, 6 and 12 weeks. 60 subjects were randomly asigned to use the 0.12% ChD mouth wash and 6i the placebo. The assessments were carried out by 5 gpds, who had previously achieved inter-examiner κ scores of 0.78–0.85 (mean 0.81) for the plaque index (PlI), and of 0.73–0.94 (mean 0.87) for a modified gingival index (mGI), and who maintained κ scores of 0.51–0.90 for PII and of 0.73–1.00 for mGI during the 12 months required to complete the study. 98 subjects (48 ChD and 50 placebo) completed the study. Even though the baseline levels of plaque and gingivitis were low, by week 12, mean whole mouth piaque score of the ChD mouthwash users had fallen from 1.33 at baseline to 0.96 and was significantly lower (p < 0.001) than for the placebo users, 1.31 at baseline to 1.13. Whole-mouth gingival bleeding score fell from 0.56 to 0.42 in the ChD mouthwash group but was unchanged (0.54–0.55) in the placebo group. A subsidiary data analysis which considered the effects at sites indicated that within these overall differences, the ChD users experienced almost 2× the reduction from plaque score 2 at baseline at proximal molar sites over a 12-week period (50.6% ChD versus 27.6% placebo). It was concluded that 0.12% ChD mouthwash reduced plaque accumulation fay 28% and gingival inflammation by 25% over a 12–week period, that it is feasible for a group of gdps to maintain high levels of inter–examiner consistency in the use of PlI and mGI, that it is also feasible to carry out such a multicentre study in general dental practice, and that the use of mean mouth scores per subject to analyse the effects of mouthrinses may well mask variations in response throughout the mouth.  相似文献   
3.
Abstrakt Vergibt ein behandelnder Arzt eine Laboruntersuchung an einen externen Laborarzt, kommt entweder direkt ein Vertragsverh?ltnis zwischen dem Laborarzt und dem Patienten zustande oder der Patient haftet dem Laborarzt aus den Grunds?tzen der Gesch?ftsführung ohne Auftrag.  相似文献   
4.
5.
Two benzofuran derivatives — analogs of 5-lipoxygenase antagonist zileuton — have been synthesized and tested. It is established that both compounds possess antiinflammatory activity. __________ Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 39, No. 12, pp. 17–20, December, 2005.  相似文献   
6.
Periosteal Ewing sarcoma   总被引:3,自引:0,他引:3  
  相似文献   
7.
8.
The Charcot-Mane-Tooth disease type 1A (CMTlA) phenotype is most often associated with a 1.5 megabase (mb), tandem duplication of chromosome 17 band p12 (17˜12). The prevailing hypothesis is that the demyelinating neuropathy results from a dosage effect of the peripheral myelin protein gene PMP22 which is included within this duplication. We present a patient with clinical and electrophysiological features ofCMTlA in whom an extra PMP22 gene resulted from a rare unbalanced translocation of 17p to the X chromosome. This finding further supports the hypothesis of gene dosage as the basis for CMTlA. More-over, this case highlights the importance of fluorescence in siiu hybridization (FISH) as an alternative molecular technique in the diagnosis of CMTlA.  相似文献   
9.
Traditionally, recombination reactions promoted by RecA-like proteins initiate by forming a nucleoprotein filament on a single-stranded DNA (ssDNA), which then pairs with homologous double-stranded DNA (dsDNA). In this paper, we describe a novel pairing process that occurs in an unconventional manner: RecA protein polymerizes along dsDNA to form an active nucleoprotein filament that can pair and exchange strands with homologous ssDNA. Our results demonstrate that this "inverse" reaction is a unique, highly efficient DNA strand exchange reaction that is not due to redistribution of RecA protein from dsDNA to the homologous ssDNA partner. Finally, we demonstrate that the RecA protein-dsDNA filament can also pair and promote strand exchange with ssRNA. This inverse RNA strand exchange reaction is likely responsible for R-loop formation that is required for recombination-dependent DNA replication.  相似文献   
10.
We studied contractile responses of isolated smooth muscles from human uterus induced by P2 receptor agonists. In preparations from pregnant uterus all tested P2 receptor agonists caused smooth muscle contractions. The relative activity of P2 receptor agonists decreased in the following order: a,b-methylene-ATP-uridine triphosphate-ATP. Responses induced by ATP and ADP were similar. The amplitude of contractions induced by alpha,beta-methylene-ATP significantly decreased in the presence of P2 receptor antagonist pyridoxal-phosphate-6-azophenyl-2',4'-disulfonic acid. None of tested P2 receptor agonists induced contractions of isolated myometrium from nonpregnant women. Our results indicate that pregnant human uterus contains P2 receptors mediating the contractile response.  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