全文获取类型
收费全文 | 1944篇 |
免费 | 113篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 19篇 |
妇产科学 | 29篇 |
基础医学 | 244篇 |
口腔科学 | 12篇 |
临床医学 | 254篇 |
内科学 | 437篇 |
皮肤病学 | 8篇 |
神经病学 | 146篇 |
特种医学 | 112篇 |
外科学 | 380篇 |
综合类 | 25篇 |
一般理论 | 3篇 |
预防医学 | 111篇 |
眼科学 | 17篇 |
药学 | 164篇 |
肿瘤学 | 103篇 |
出版年
2023年 | 7篇 |
2022年 | 17篇 |
2021年 | 43篇 |
2020年 | 25篇 |
2019年 | 28篇 |
2018年 | 47篇 |
2017年 | 32篇 |
2016年 | 29篇 |
2015年 | 28篇 |
2014年 | 80篇 |
2013年 | 76篇 |
2012年 | 117篇 |
2011年 | 125篇 |
2010年 | 67篇 |
2009年 | 62篇 |
2008年 | 115篇 |
2007年 | 128篇 |
2006年 | 107篇 |
2005年 | 107篇 |
2004年 | 106篇 |
2003年 | 102篇 |
2002年 | 91篇 |
2001年 | 51篇 |
2000年 | 42篇 |
1999年 | 47篇 |
1998年 | 28篇 |
1997年 | 22篇 |
1996年 | 11篇 |
1995年 | 24篇 |
1994年 | 19篇 |
1993年 | 18篇 |
1992年 | 17篇 |
1991年 | 26篇 |
1990年 | 19篇 |
1989年 | 16篇 |
1988年 | 19篇 |
1987年 | 16篇 |
1986年 | 11篇 |
1985年 | 10篇 |
1984年 | 15篇 |
1983年 | 6篇 |
1982年 | 9篇 |
1979年 | 9篇 |
1978年 | 11篇 |
1976年 | 6篇 |
1975年 | 8篇 |
1974年 | 6篇 |
1973年 | 10篇 |
1971年 | 9篇 |
1969年 | 8篇 |
排序方式: 共有2073条查询结果,搜索用时 31 毫秒
1.
M M Smith J E Thompson D Thomas M Castillo D Carrier S K Mukherji D Gilliam 《AJNR. American journal of neuroradiology》1997,18(2):327
Choristomas, masses of normal tissues in aberrant locations, contain smooth muscle fibers and fibrous tissues. We describe the MR imaging features of two choristomas located in the internal auditory canals and arising from the facial and vestibulocochlear nerves. Both lesions enhanced with contrast material. In one case, enhancement was seen in the geniculate ganglion and greater superficial petrosal nerve. In the other, a medial component enhanced less than the lateral component did. 相似文献
2.
Calcium release from sarcoplasmic reticulum was investigated using skinned fibers isolated from rabbit semitendinosus and psoas muscles, representative of slow and fast fibers, respectively. In both types of fibers, halothane at the concentration of 0.03% (v/v) enhanced the Ca2(+)-induced calcium release. In the absence of cytoplasmic free Ca2+, halothane induced calcium release in a dose-dependent manner, with a similar sensitivity for both semitendinosus and psoas fibers. These results are discussed in connection with muscular diseases such as malignant hyperthermia in which the crisis is triggered during anesthesia by halothane. 相似文献
3.
Jean-Francois Morin M.D. Bergez F. Mistry M.D. FRCPC Lisa Knowlton M.D. 《Journal of cardiac surgery》2007,22(4):356-358
Abstract In this case report we describe a situation where despite a normal TEE exam immediately postcardiopulmonary bypass, there was no flow in the left internal mammary artery graft to the left anterior descending artery. This was picked up by coronary Doppler and subsequently repaired. 相似文献
4.
Cephalometric measurements in snorers, non-snorers, and patients with sleep apnoea. 总被引:7,自引:4,他引:3
下载免费PDF全文
![点击此处可从《Thorax》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Cephalometry is often used to assess patients with sleep apnoea but whether these measurements differ from those in non-apnoeic snorers and how they are influenced by age is not clear. Cephalometric radiographs of patients with sleep apnoea were compared with those of snorers without sleep apnoea and those of non-snorers. Fifty two snorers with suspected sleep apnoea had a conventional sleep study and were divided into two groups: those with an apnoea-hypopnoea index greater than 10/h (n = 40, sleep apnoea group) and those whose apnoea-hypopnoea index was 10/h or less (n = 12, snorer group). The cephalometric measurements in these patients were compared with those of 34 non-snoring control subjects. Controls were subdivided into two groups: control group 1 included 17 subjects similar in age to the sleep apnoea and snorer groups (mean (SD) age 50.0 (10.9), 50.7 (9.4), and 50.6 (9.7) years); control group 2 included 15 young men (25.4 (2.6) years). The distance from the mandibular plane to the hyoid bone (MP-H) and the length of the soft palate were greater in the patients with sleep apnoea (28.7 (7.8) and 43.6 (5.0) mm) than in the snorers (23.7 (4.2) and 40.3 (4.9 mm). The MP-H was similar in snorers and age matched control subjects, but was significantly greater in the older than in the younger control subjects (22.1 (6.1) vs 17.0 (6.8]. The soft palate was longer in subjects who snored (both sleep apnoea patients and snorers) than in control subjects. The MP-H distance significantly correlated with age for all subjects (snorers and controls) and for the control subjects alone. This study shows that non-apnoeic snorers have cephalometric abnormalities that differ from those of patients with sleep apnoea and that cephalometric values are influenced by the subject's age. 相似文献
5.
6.
Variable sensitivity and specificity of TTF-1 antibodies in lung metastatic adenocarcinoma of colorectal origin. 总被引:3,自引:0,他引:3
7.
8.
9.
OBJECTIVES: To evaluate the demand for organs for transplantation and to recommend a reorganization of transplantation services in Quebec. DESIGN: Retrospective study. SETTING: Province of Quebec, 1988 to 1992. PATIENTS: All patients on waiting lists for organ transplantation and patients who received transplants registered in national data banks. MAIN OUTCOME MEASURES: The actual annual demand for organ transplantation and the rate of transplantations performed. RESULTS: The rates of heart transplantation were lower than the actual annual demand, which resulted in many patients dying while awaiting transplantation. The actual annual demand for heart transplantation decreased during the last 5 years from 10.9 per million people in 1987 to 6.7 in 1992. The rates of heart transplantation in Quebec were higher than the Canadian average. The actual demand for lung transplantation was only 2.9 per million people on average in 1992. Demand for liver transplantation increased annually, reaching 8.6 per million in 1992. The rate of transplantation increased likewise but remained insufficient. The demand for kidney transplantation reached 27.2 per million people in 1992, and the transplantation rate was 17.8. CONCLUSIONS: Taking into account the actual demand for and supply of organ transplantation, to insure high-quality service and to control costs associated with organ transplantation, we recommend that the present system in Quebec be reorganized so that transplantations are performed in 12 centres: 7 for kidney transplantation, 2 for hearts, 2 for livers and 1 for lungs. 相似文献
10.
Jean-Francois Légaré Ansar Hassan Karen J Buth John A Sullivan 《Journal of cardiothoracic surgery》2007,2(1):44-8