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   690篇
  免费   49篇
  国内免费   3篇
耳鼻咽喉   12篇
儿科学   34篇
妇产科学   7篇
基础医学   56篇
口腔科学   6篇
临床医学   56篇
内科学   212篇
皮肤病学   10篇
神经病学   17篇
特种医学   61篇
外科学   104篇
综合类   5篇
预防医学   15篇
药学   64篇
中国医学   3篇
肿瘤学   80篇
  2022年   10篇
  2021年   16篇
  2020年   12篇
  2019年   15篇
  2018年   20篇
  2017年   14篇
  2016年   17篇
  2015年   17篇
  2014年   12篇
  2013年   14篇
  2012年   18篇
  2011年   26篇
  2010年   30篇
  2009年   20篇
  2008年   29篇
  2007年   37篇
  2006年   19篇
  2005年   22篇
  2004年   25篇
  2003年   36篇
  2002年   19篇
  2001年   16篇
  2000年   27篇
  1999年   36篇
  1998年   9篇
  1997年   5篇
  1996年   8篇
  1995年   12篇
  1993年   5篇
  1992年   29篇
  1991年   18篇
  1990年   17篇
  1989年   13篇
  1988年   8篇
  1987年   17篇
  1986年   10篇
  1985年   13篇
  1984年   4篇
  1983年   8篇
  1982年   5篇
  1979年   5篇
  1978年   4篇
  1977年   3篇
  1975年   4篇
  1974年   7篇
  1973年   3篇
  1972年   3篇
  1971年   3篇
  1968年   3篇
  1967年   3篇
排序方式: 共有742条查询结果,搜索用时 15 毫秒
11.
In mail testing, a testee collects samples at home from his or her own body, and mails them to the medical institution. Because the testee does not need to attend the medical institution, an advantage of mail testing is that it is not time-consuming. Because the amount of sample is small and time from sampling to measurement is long, the manner of collecting and transporting samples are important factors affecting the precision of the result. There is the risk that inappropriate sample picking can occur, as the testee, who is not skilled in medical testing, may obtain the sample. Moreover, the samples may include blood, urine, secretions, and so on. Depending on the purpose of the test, the transport and sampling method varies, and the character of the sampling device and transport method influence the procedure required. I describe collection methods and other issues in this paper according to medical examination item, sample, and sampling.  相似文献   
12.
BACKGROUND: The submucosal tumor (SMT) of the esophagus presents good indications for minimal invasive surgery, such as endoscopic or thoracoscopic resection. However, it is essential that the layer of origin be ascertained. The SMT can be detected as hypoechoic lesions in the wall of the esophagus, and the intramural location can be estimated in terms of destruction or deviation of the ultrasonic layer structure of the esophagus. METHODS: To test the efficacy of this approach, a series of patients were examined by an endoscopic ultrasonography (EUS). RESULTS: In one patient, the lesion was diagnosed as located in the muscularis mucosa, and endoscopic resection was performed. In another four patients, the lesions appeared to be in the proper muscle layer, and enucleation was carried out under thoracoscopy or open surgery. Histologically, all of the lesions were leiomyomas, and the EUS diagnosis was correct in all of the patients. CONCLUSIONS: Thus, the intramural condition of SMTs can be estimated and indications for endoscopic or thoracoscopic resection assessed by this approach.  相似文献   
13.
The effects of Z-350, (S)-4-[3-(4-{1-(4-methylphenyl)-3-[4-(2-methoxyphenyl)piperazine-1-yl]propoxy} benzoyl)indole-1-yl]butyric acid hydrochloride, a newly synthesized compound possessing α1-adrenoceptor antagonistic and steroid 5α-reductase inhibitory actions, were studied in vitro. In functional experiments, Z-350 shifted the concentration/response curve for the phenylephrine-induced contraction of rabbit prostate, urethra and aorta to the right with pA2 values of 8.04, 7.57 and 7.13, respectively. The binding affinity of Z-350 for α1-adrenoceptors in rabbit prostate, urethra and aorta were estimated by the displacement of [3H]prazosin. The pK i values for this action of Z-350 were 7.53, 7.95 and 7.62 for the prostate, urethra and aorta, respectively. α1-Adrenoceptor subtype selectivities were studied in the submaxillary gland (α1A) and liver (α1B) of rat. Z-350 inhibited the specific binding of [3H]prazosin to α1A and α1B-adrenoceptors with pK i values of 7.82 and 7.29, respectively. Z-350 inhibited rat prostatic steroid 5α-reductase non-competitively with a pIC50 of 8.42. These results indicate that Z-350 is a α1-adrenoceptor antagonist and is a steroid 5α-reductase inhibitor. It is expected that Z-350 will be a candidate drug for the treatment of benign prostatic hyperplasia. Received: 26 January 1999 / Accepted: 2 March 1999  相似文献   
14.
Adrenal enlargement was followed by serial ultrasonography in an infant with congenital lipoid adrenal hyperplasia (lipoid CAH) from day 12 until 2 years and 4 months of age, when they were no longer detectable. Contrary to other types of CAH in which the configuration changes soon after replacement therapy, this infant with lipoid CAH showed persistent adrenal cortex enlargement due to massive accumulation of lipids and cholesterol resulting in a damaged glandular cyto-architecture. Conclusion ultrasonographically persistent enlargement of the adrenals after replacement therapy is suggestive of the lipoid form of CAH. Received: 3 June 1997 / Accepted in revised form: 19 December 1997  相似文献   
15.
Background and Aim: Limited data are available regarding the use of endoscopic submucosal dissection (ESD) for superficial esophageal cancers ≥50 mm in diameter. The aim of the present study was to investigate the safety and success of ESD for superficial esophageal cancers ≥50 mm. Methods: A total of 39 patients with superficial esophageal squamous cell carcinoma ≥50 mm were treated with ESD at Osaka Medical Center for Cancer and Cardiovascular Diseases between January 2004 and April 2011, and were analyzed in a retrospective study. Results: En bloc resection was achieved in all patients. One mediastinal emphysema without perforation occurred during the procedure. Stricture developed in 11 of 39 patients, requiring a median of five endoscopic balloon dilatation procedures. Thirty‐three clinical epithelial or lamina propria mucosal cancers were treated by ESD with curative intent, of which invasion into the muscularis mucosa or deeper was detected in seven and lymphovascular involvement in three. The en bloc resection rate was 100% with a tumor‐free margin achieved in 92% of lesions. The curative resection and complication rates during ESD were 70% and 2.5%, respectively. Conclusion: ESD achieved a high en bloc resection rate of 92% with a tumor‐free margin. Curative resection rate of ESD in patients with clinical epithelial or lamina propria mucosal cancers was not low at 70%. However, the risk of stricture must be taken into account when considering the use of ESD in lesions ≥50 mm.  相似文献   
16.
17.
BACKGROUND: Image quality of the prior autofluorescence (AF) imaging systems, including the fiber-optic endoscope, was not feasible for general clinical use. The use of AF image alone resulted in low specificity. The objective of the study was to evaluate the resolution and the sensitivity of the novel videoendoscopy system by using AF and reflectance imaging (AFI) in the diagnosis of early esophagogastric cancers. METHODS: This was a case series study. The setting was a pretreatment examination at a cancer center. Five patients with superficial esophageal cancers (SEC) and 21 patients with 22 early gastric cancers (EGC) were included in the study. The extent of the tumors was diagnosed by white light (WL), AF and chromoendoscopic observations. The main outcome measurement was the diagnostic accuracy of each observation in relation to the histologic mapping as a criterion standard. RESULTS: Two of 5 SECs (40%) were correctly diagnosed in the WL image and all (100%) in the AF image as purple or magenta color in a green background. EGCs in atrophic mucosa were observed as purple or magenta areas in a green background, while diffuse-type EGCs in fundic mucosa were observed as green areas in a purple background. Of the 22 EGCs, diagnostic accuracy of WL, AF, and chromoendoscopic observations were 36%: 95% CI [16%, 56%], 68%: 95% CI [49%, 88%], and 91%: 95% CI [79%, 100%], respectively. AFI could reveal flat or isochromatic extensions that were not detected in the WL images. The limitations of the study were ulcerations or inflammation that caused overdiagnosis in the AF observation. CONCLUSIONS: The resolution of the AFI at present is limited, but the image quality was acceptable. The current system of AFI does not equal to chromoendoscopy in sensitivity but has an advantage over standard WL videoendoscopy.  相似文献   
18.
Summary The chronic effects of the oral administration of OPC-8212 (3,4-DIHYDRO-6-[4-(3,4-dimethoxybenzoyl)-1-piperazinyl]-2(1H)-quinolinone) on resting hemodynamics and exercise capacity were assessed in 15 patients with congestive heart failure (NYHA II–IV). Doses of 30 or 60 mg per day were given per os over 3.0 weeks on average (range 2–6 weeks). Multigated radionuclide ventriculography and multistage exercise testing were performed before and during OPC-8212 therapy to assess the changes in left ventricular volume and exercise capacity respectively. Systolic blood pressure showed a slight increase (from 123±3 to 129±4 mmHg) during OPC-8212 therapy, while heart rate was unchanged (69±3 vs 67±3 beats/min). The left ventricular end-diastolic volume index decreased from 127±9 to 107±7 ml/m2, and ejection fraction and the P/V index (the ratio of peak systolic pressure to left ventricular end-systolic volume index) increased during OPC-8212 therapy (from 27%±3% to 30%±4% and from 1.5±0.2 to 2.0±0.3 mmHg/ml/m2 respectively). NYHA functional class was improved in 9 of 15 patients, and the average peak work load achieved during exercise testing increased from 27±6 to 47±7 W. No significant adverse effect was observed in any patient. These results indicate that OPC-8212 enhances the inotropic state and, hence, reduces heart size with no change in heart rate. Moreover, it increases exercise capacity. Thus, OPC-8212 is an inotropic agent with promise for application in the long-term treatment of congestive heart failure.  相似文献   
19.
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