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   3665篇
  免费   235篇
  国内免费   17篇
耳鼻咽喉   33篇
儿科学   101篇
妇产科学   60篇
基础医学   458篇
口腔科学   154篇
临床医学   291篇
内科学   894篇
皮肤病学   122篇
神经病学   248篇
特种医学   174篇
外国民族医学   1篇
外科学   407篇
综合类   14篇
预防医学   157篇
眼科学   103篇
药学   270篇
中国医学   16篇
肿瘤学   414篇
  2023年   49篇
  2022年   84篇
  2021年   165篇
  2020年   85篇
  2019年   121篇
  2018年   153篇
  2017年   120篇
  2016年   112篇
  2015年   105篇
  2014年   137篇
  2013年   161篇
  2012年   269篇
  2011年   316篇
  2010年   162篇
  2009年   128篇
  2008年   226篇
  2007年   208篇
  2006年   202篇
  2005年   177篇
  2004年   170篇
  2003年   149篇
  2002年   134篇
  2001年   49篇
  2000年   53篇
  1999年   57篇
  1998年   37篇
  1997年   13篇
  1996年   16篇
  1995年   18篇
  1994年   11篇
  1993年   7篇
  1992年   26篇
  1991年   27篇
  1990年   28篇
  1989年   21篇
  1988年   13篇
  1987年   12篇
  1986年   9篇
  1985年   19篇
  1984年   7篇
  1982年   3篇
  1981年   6篇
  1980年   5篇
  1979年   7篇
  1976年   4篇
  1975年   5篇
  1973年   3篇
  1971年   5篇
  1970年   3篇
  1969年   4篇
排序方式: 共有3917条查询结果,搜索用时 15 毫秒
1.
2.
3.
Hidroacanthoma simplex (HAS) is a rare benign eccrine adnexal tumor. HAS is sometimes clinically or pathologically misdiagnosed as squamous cell carcinoma in situ (Bowen's disease; BD), seborrheic keratosis (SK) or other adnexal tumor. To date, there has never been a report focusing on dermoscopic features to distinguish HAS from BD and SK. We found the following dermoscopic findings to be characteristic of HAS: fine black dots/globules (75% of cases) and fine scales arranged annularly (100% of cases). In contrast, glomerular vessels, which are typically observed in BD, were not seen in any of the four cases. Cerebriform appearance and milia‐like cysts, which are typically observed in SK, were also not seen in any of the four cases. The existence of “scattered fine black dots/globules” and “fine scales arranged annularly”, and the absence of the glomerular vessels, may contribute to precise diagnosis of HAS. Even though HAS resembles BD or SK clinically, it can be distinguished from these by the characteristic dermoscopic features.  相似文献   
4.
Two cases of vasovagal syncope (VVS) during venous access are reported. Both patients had a history of fainting episodes and experienced bradycardia with asystole, hypotension, and fainting. Pain and phobic stress during venous access triggered an increase in parasympathetic tone, resulting in bradycardia with asystole and hypotension in both cases. Hypotension and bradycardia likely caused cerebral hypoperfusion, leading to fainting. The intense parasympathetic tone triggered by somatic or emotional stress was likely responsible for directly depressing the sinus node, leading to asystole and bradycardia. Bradycardia with asystole progressing to syncope is a potentially fatal dysrhythmia in patients with cardiovascular disease or older patients with decreased cardiac function. Appropriate treatment for VVS includes the administration of intravenous fluids, vagolytics, ephedrine, and the rapid use of the Trendelenburg position. Intravenous fluids and atropine were used to treat the present patients.  相似文献   
5.
Iron deficiency (ID) is one of the most commonly known forms of nutritional deficiencies. Low body iron is thought to induce neurologic defects but may also play a protective role against cancer development by cell growth arrest. Thus, ID may affect cellular pathways controlling cell growth and proliferation, the mechanism of which is still not fully understood. The serine/threonine protein kinase Akt and its downstream target, the mammalian Target of Rapamycin (mTOR), is known to play a crucial role in the regulation of cell growth and survival. Therefore, we hypothesized that Akt/mTOR pathway could be influenced by ID. Three-week-old male Wistar-strain rats were divided into 3 groups and the 2 groups had free access to a control diet (C group) or an iron-deficient diet (D group). The third group (PF group) were pair-fed the control diet to the mean intake of the D group. After 4 weeks, rats were killed and their brains were sampled. In separate experiments, COS-1 cells were cultured with or without the iron chelator deferoxamine. Western blots of brain samples and COS-1 lysates were used to analyze the expression and phosphorylation state of Akt, TSC2, mTOR, and S6 kinase proteins implicated in the Akt/mTOR pathway. Using 2 different ID models, we show for the first time that iron deficiency depresses Akt activity in rats and in COS-1 cells, leading to a decrease in mTOR activity.  相似文献   
6.
The second derivative of the finger photoplethysmogram (SDPTG) has been used as a non-invasive examination for arterial stiffness. The present study sought to elucidate independent determinants of the SDPTG among various cardiovascular risk factors in middle-aged Japanese men. The SDPTG was obtained from the cuticle of the left-hand forefinger in 973 male workers (mean age: 44+/-6 years) during a medical checkup at a company. The SDPTG indices (b/a and d/a) were calculated from the height of the wave components. Multiple logistic regression analyses revealed that the independent determinants of an increased b/a (highest quartile of the b/a) were age (odds ratio [OR]: 1.12 per 1-year increase, 95% confidence interval [CI]: 1.09-1.15), hypertension (OR: 1.65, 95% CI: 1.03-2.65), dyslipidemia (OR: 1.51, 95% CI: 1.09-2.09), impaired fasting glucose/diabetes mellitus (OR: 2.43, 95% CI: 1.16-5.07), and a lack of regular exercise (OR: 2.00, 95% CI: 1.29-3.08). Similarly, independent determinants of a decreased d/a (lowest quartile of the d/a) were age (OR: 1.11 per 1-year increase, 95% CI: 1.08-1.14), hypertension (OR: 3.44, 95% CI: 2.20-5.38), and alcohol intake 6 or 7 days per week (OR: 2.70, 95% CI: 1.80-4.06). No independent association was observed between the SDPTG indices and blood leukocyte count or serum C-reactive protein levels. In conclusion, the SDPTG indices reflect arterial properties affected by several cardiovascular risk factors in middle-aged Japanese men. The association between inflammation and the SDPTG should be evaluated in further studies.  相似文献   
7.
8.
Aneurysms of the inferior left ventricular wall represent only a small fraction of all aneurysms that have been reported in surgical series. And in comparison to anterior left ventricular aneurysms, a comparatively higher percentage of reported inferior wall aneurysms was classified as false. A 73-year-old male was admitted for acute inferior myocardial infarction. Three weeks after admission, cardiac catheterization was carried out. Coronary arteriography revealed triple vessel disease and left ventriculography showed an aneurysm of the inferior left ventricular wall, whose feature near the mitral annulus was multiple fenestrations. Left ventricular aneurysmectomy and aortocoronary bypass grafting to the left anterior descending artery were simultaneously performed under cardiopulmonary bypass with moderate hypothermia. The pathological feature was a true aneurysm. The postoperative course was uneventful.  相似文献   
9.
10.
Objectives To develop a simple image viewer that utilizes image files in general-purpose formats that are written from the original 3DX volume data. Methods We used FLASH MX2004 for Macintosh to develop a simple image viewer. In developing the software for the simple image viewer, we decided that the viewer should provide the following features: (1) be available to both Windows OS and Mac OS, (2) allow interlocking of the 3D images, (3) display image enlargement, and (4) allow distance measurements. The accuracy of the distance measurements was evaluated. Results The procedure was as follows: (1) write 3D images in jpeg format to a folder on i-VIEW; (2) place the folder containing the 3D images into the directory of the simple image viewer software on a PC; (3) start the software and open the window to input the folder name containing the 3D images; and (4) display the 3D images. Our viewer had features such as image enlargement, interlocking 3D images, drawing, and distance measurements. No significant differences were shown between the measurements made by our simple viewer and the actual values of the images in any direction. Conclusions Our image-viewing software for 3DX is beneficial for clinical use.  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