全文获取类型
收费全文 | 6663篇 |
免费 | 399篇 |
国内免费 | 39篇 |
专业分类
耳鼻咽喉 | 79篇 |
儿科学 | 183篇 |
妇产科学 | 228篇 |
基础医学 | 958篇 |
口腔科学 | 177篇 |
临床医学 | 551篇 |
内科学 | 1216篇 |
皮肤病学 | 170篇 |
神经病学 | 453篇 |
特种医学 | 290篇 |
外科学 | 906篇 |
综合类 | 216篇 |
一般理论 | 2篇 |
预防医学 | 665篇 |
眼科学 | 114篇 |
药学 | 542篇 |
中国医学 | 66篇 |
肿瘤学 | 285篇 |
出版年
2023年 | 33篇 |
2022年 | 75篇 |
2021年 | 193篇 |
2020年 | 98篇 |
2019年 | 171篇 |
2018年 | 205篇 |
2017年 | 150篇 |
2016年 | 137篇 |
2015年 | 200篇 |
2014年 | 231篇 |
2013年 | 287篇 |
2012年 | 484篇 |
2011年 | 502篇 |
2010年 | 275篇 |
2009年 | 214篇 |
2008年 | 368篇 |
2007年 | 365篇 |
2006年 | 318篇 |
2005年 | 288篇 |
2004年 | 308篇 |
2003年 | 236篇 |
2002年 | 246篇 |
2001年 | 188篇 |
2000年 | 218篇 |
1999年 | 167篇 |
1998年 | 91篇 |
1997年 | 71篇 |
1996年 | 60篇 |
1995年 | 41篇 |
1994年 | 45篇 |
1993年 | 46篇 |
1992年 | 76篇 |
1991年 | 60篇 |
1990年 | 64篇 |
1989年 | 71篇 |
1988年 | 56篇 |
1987年 | 67篇 |
1986年 | 47篇 |
1985年 | 45篇 |
1984年 | 24篇 |
1983年 | 32篇 |
1982年 | 29篇 |
1981年 | 17篇 |
1979年 | 15篇 |
1978年 | 26篇 |
1977年 | 16篇 |
1976年 | 22篇 |
1975年 | 15篇 |
1974年 | 17篇 |
1972年 | 13篇 |
排序方式: 共有7101条查询结果,搜索用时 15 毫秒
1.
Sim Sai TIN Viroj WIWANITKIT 《Revista do Instituto de Medicina Tropical de S?o Paulo》2015,57(2):184-Apr;57(2):184
2.
3.
4.
Paula Cristina Galati Paula Garcia Chiarello Belinda Pinto Simões 《Nutrition and cancer》2016,68(1):86-93
Changes in resting energy expenditure (REE) of cancer patients vary depending on type of tumor, treatment time point and kind of treatment. Little is known about REE of acute leukemia adult patients after treatment, especially with results related to body weight or fat free mass (FFM). This study aimed to assess changes in REE of acute leukemia adult patients before and after the first remission induction. Evaluation of REE was performed by indirect calorimetry and predicted REE was calculated by Harris-Benedict equation. Weight and height were measured and compared to a control group of healthy individuals. FFM was assessed by bioelectrical impedance for adjusting REE values. We evaluated 18 patients and 26 healthy individuals. At diagnosis, patients presented REE, REE/weight, and REE/FFM higher than the controls. Reductions of REE, REE/weight, and REE/FFM were also observed in patients after the first cycle of chemotherapy. The predicted REE for the patients group showed significant lower value compared with measured REE. Before the first cycle of chemotherapy REE was increased but undergoes a reduction after treatment, reaching values similar to the controls. For predictive Harris-Benedict equation, stress factors should be added to avoid underestimation of REE before and after chemotherapy. 相似文献
5.
Akira Sawaki Nobumasa Mizuno Kuniyuki Takahashi Tsuneya Nakamura Masahiro Tajika Hiroki Kawai Toshifumi Isaka Hiroshi Imaoka Yasuyuki Okamoto Masatoshi Aoki Hiroyuki Inoue Ahmed AS Salem Yasushi Yatabe Kenji Yamao 《Digestive endoscopy》2006,18(1):40-44
Background: Gastrointestinal stromal tumors (GIST) are one of the most common mesenchymal tumors of the gastrointestinal tract. GIST are defined by positive immunohistochemical staining for KIT or CD34 and thus are generally diagnosed after surgery. Because small GIST are rarely diagnosed before surgery, the clinical course of these small tumors is not clear. The aim of the present study was to follow changes in size and configuration of small GIST that were pathologically confirmed using endoscopic ultrasonography‐guided fine‐needle aspiration biopsy (EUS‐FNAB). Methods: Between July 1997 and December 2003, 16 tumors in 16 patients (10 men and 6 women) with an immunohistochemical diagnosis of GIST were regularly followed in our hospital. The median patient age when EUS‐FNAB was performed was 62 years (range 26–82 years) and the median follow‐up period was 4.9 years (range 0.5–9.6 years). Results: Fourteen tumors showed no remarkable changes in size and shape during follow up compared with the initial diagnosis. Two tumors enlarged: one tumor approximately doubled its diameter in 8 years and the other tumor increased from 1.8 cm at diagnosis to up to 10 cm after only 2 years. Doubling time of the latter tumor was calculated as 3.1 months. Conclusions: We conclude that EUS‐FNAB might be a good modality for final diagnosis of GIST without surgery, and that GIST without rapid growth on follow up can be endoscopically followed. 相似文献
6.
7.
Jorge Guardado Carlos Cotrim Otília Sim?es Sofia Almeida Mário Ialá Luís Lopes Hélder Pereira Manuel Carrageta 《Revista portuguesa de cardiologia》2006,25(4):409-415
INTRODUCTION: Transesophageal echocardiography (TEE) has become increasingly useful in the study of patients with suspected pulmonary thromboembolism. OBJECTIVE: The aim of this study was to prospectively evaluate the usefulness of TEE in the study of the distal part of the left pulmonary artery (LPA) as well as the influence of this procedure on total echocardiographic exam duration. METHODOLOGY: A prospective study in two groups of consecutive patients referred for TEE with a one- year interval between evaluation of Group A: 33 patients, 17 male, mean age 54 +/- 24 years, and Group B: 42 patients, 20 male, mean age 48 +/- 27 years (p = NS). The procedure was considered long when it took more than 3 min to evaluate the distal part of the LPA. RESULTS: In group A we were able to visualize the distal part of the LPA in 24 patients (73%) without significant prolongation of total exam duration in 16 patients (48% of group A). In one of the patients with suspected pulmonary thromboembolism thrombi were only observed in the distal part of the LPA. In group B we were able to visualize the distal part of the LPA in 36 patients (86%) without significant prolongation of total exam duration in 26 patients (61% of group B). CONCLUSIONS: 1. Visualization of the distal part of the LPA was possible in more patients, and with TEE time prolongation in less patients, in group B. These differences can be accounted for by the training of the operator in this technique. 2. The importance of visualization of this part of the LPA in guiding treatment in the subset of patients with pulmonary thromboembolism confirms the usefulness of this specific procedure. 相似文献
8.
9.
Coronary artery bypass grafts: visualization with MR imaging 总被引:1,自引:0,他引:1
10.
The performance of a tooth replacement by using a dental implant relies on the mechanical and biological capability of the anatomical substitute to restore lost physiological functions. The design of an implant device able to properly replace the physiological tooth requires the study of the load transfer mechanism at the implant-bone interface and the understanding of the relevance of the periodontal ligament (PDL) in this mechanism. The PDL is a connective soft tissue that provides the fixation of the tooth in its bone-socket and the attenuation of occlusal loads. It also provides the ground cells that are involved in the remodelling process, induced by a change in the stress-strain pattern of the alveolar bone and also in the cementum of the tooth root. The purpose of this study was to determine the PDL effects on the dynamic load transfer mechanism, from the tooth to the alveolar bone, evaluating the equivalent dynamic stiffness of the ligament structure. A porcine fresh mandible with a tooth was used within the study, applying an experimental procedure to identify the dynamic transmissibility of the entire system. The transmissibility function provided information about the stiffness and damping of the PDL, information that can assist the design of an improved dental implant system. 相似文献