全文获取类型
收费全文 | 2450篇 |
免费 | 104篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 34篇 |
妇产科学 | 13篇 |
基础医学 | 294篇 |
口腔科学 | 109篇 |
临床医学 | 154篇 |
内科学 | 901篇 |
皮肤病学 | 13篇 |
神经病学 | 144篇 |
特种医学 | 118篇 |
外科学 | 273篇 |
综合类 | 6篇 |
预防医学 | 77篇 |
眼科学 | 14篇 |
药学 | 157篇 |
中国医学 | 1篇 |
肿瘤学 | 258篇 |
出版年
2023年 | 23篇 |
2022年 | 44篇 |
2021年 | 73篇 |
2020年 | 36篇 |
2019年 | 46篇 |
2018年 | 58篇 |
2017年 | 45篇 |
2016年 | 50篇 |
2015年 | 51篇 |
2014年 | 71篇 |
2013年 | 91篇 |
2012年 | 169篇 |
2011年 | 158篇 |
2010年 | 86篇 |
2009年 | 79篇 |
2008年 | 134篇 |
2007年 | 158篇 |
2006年 | 146篇 |
2005年 | 138篇 |
2004年 | 145篇 |
2003年 | 101篇 |
2002年 | 130篇 |
2001年 | 31篇 |
2000年 | 28篇 |
1999年 | 34篇 |
1998年 | 42篇 |
1997年 | 18篇 |
1996年 | 23篇 |
1995年 | 27篇 |
1994年 | 30篇 |
1993年 | 29篇 |
1992年 | 33篇 |
1991年 | 14篇 |
1990年 | 23篇 |
1989年 | 26篇 |
1988年 | 18篇 |
1987年 | 16篇 |
1986年 | 16篇 |
1985年 | 17篇 |
1984年 | 21篇 |
1983年 | 13篇 |
1982年 | 12篇 |
1981年 | 14篇 |
1980年 | 11篇 |
1979年 | 4篇 |
1978年 | 8篇 |
1974年 | 5篇 |
1973年 | 4篇 |
1971年 | 5篇 |
1969年 | 4篇 |
排序方式: 共有2575条查询结果,搜索用时 31 毫秒
81.
Turin TC Murakami Y Miura K Rumana N Kadota A Ohkubo T Okamura T Okayama A Ueshima H;NIPPON DATA Research Group 《Diabetes research and clinical practice》2012,96(2):e18-e22
Life expectancy (LE) among the Japanese population with or without diabetes mellitus was estimated. LE in 40-year old men and women was 41.1 and 47.5 years in those without diabetes and 32.3 and 40.9 years in those with diabetes. The LE of 40-year old men and women with diabetes was 8.8 and 6.6 years shorter than in those without diabetes. Diabetes mellitus leads to a decrease in LE. The presence of impaired glucose tolerance also affected LE inversely. 相似文献
82.
83.
Ikiru Atsuta Yasunori Ayukawa Takayoshi Yamaza Akihiro Furuhashi Kiyoshi Koyano 《Archives of oral biology》2013
Background
Oral epithelial cells (OECs) adhesion to titanium may improve the success rate of implant restoration.Purpose
We investigated the mechanism by which OECs adhere to titanium dental implants.Materials and methods
(1) After culturing rat OECs on titanium plates (Ti) or culture dishes in the presence or absence of a phosphoinositide 3-kinase (PI3K) activator or inhibitors and/or growth factors, and OEC morphology under these conditions were analyzed. (2) Right maxillary first molars were extracted and replaced with experimental implants. The rats were treated with or without growth factors.Results
(1) Cell adherence was lower of OECs on Ti than in those on culture dishes, as were the levels of integrin β4 and the continuity of F-actin structures. After PI3K inhibition, markedly reducing adherence to both substrates. In contrast, PI3K activation with activator or insulin-like growth factor restored the OEC adherence and the expression of adhesion molecules on Ti to the levels seen in OECs cultured on dishes. Cell migration was inhibited by PI3K activation. (2) High expression of integrin β4 was observed in the peri-implant epithelia of PI3K-activated rats.Conclusion
These findings suggest that PI3K plays an important role in the adhesion of OECs to Ti. 相似文献84.
85.
Takayoshi Sakai Tomohiro Onodera 《Journal of oral biosciences / JAOB, Japanese Association for Oral Biology》2013,55(2):73-75
During embryonic development, many internal organs are formed through repetitive branching morphogenesis of epithelial tissue. In this study, we determined that the fibronectin-induced gene BTB (POZ) domain containing 7 (Btbd7)/Cleftin plays an important role in this process, and we analyzed how this gene regulates cleft formation. We demonstrated that branching morphogenesis of epithelial tissue is controlled by Btbd7/Cleftin during salivary gland and lung formation. Btbd7/Cleftin, acting through other proteins such as E-cadherin and Snail2, regulates the branching morphogenesis of the epithelial cells that form a cleft structure. Furthermore, disruption of cell–cell adhesion by Btbd7/Cleftin induces epithelial cell migration, which is required for branching morphogenesis of the organ. 相似文献
86.
87.
Kojima T Kaneko A Hirano Y Ishikawa H Miyake H Oguchi T Takagi H Yabe Y Kato T Ito T Terabe K Fukaya N Kanayama Y Shioura T Funahashi K Hayashi M Kato D Matsubara H Fujibayashi T Kojima M Ishiguro N;TBC 《Modern rheumatology / the Japan Rheumatism Association》2012,22(3):339-345
Biologic agents have proven to be effective against rheumatoid arthritis (RA) in clinical trials and post-marketing surveillance (PMS) studies. However, limited follow-up periods and strict criteria for recruitment might lead to an underestimation of adverse events. To document the long-term course of patients with RA treated with biologics in clinical settings, we established the Tsurumai Biologics Communication Registry (TBCR). First, we retrospectively collected data of patients registered for any biologic PMS study or clinical trial at participating institutes. Thus far, thirteen institutes have joined the registry and 860 patients have been identified. Comparing baseline characteristics by age and initiation year of biologics, young patients had significantly less joint damage and dysfunction and a higher dose of concomitant methotrexate (MTX) compared to older patients. Older age and functional class were significantly related to the incidence of adverse events that resulted in discontinuation of the 1st biologic treatment. The TBCR is in its initial stages, and information on all patients newly starting biologic therapy at participating institutes is being collected prospectively. Differences in baseline characteristics by age and initiation year of biologics need to be carefully evaluated in order to report on drug-related survival and long-term prognosis, using follow-up data in the near future. 相似文献
88.
Hiroyuki Nishi Taichi Sakaguchi Shigeru Miyagawa Yasushi Yoshikawa Satsuki Fukushima Shunsuke Saito Takayoshi Ueno Toru Kuratani Yoshiki Sawa 《Surgery today》2013,43(10):1134-1139
Purpose
Postoperative atrial fibrillation/flutter (AF) is still the most common complication after cardiovascular surgery, and it is important to determine the risk factors in order to establish effective management for recent postoperative AF. This study investigated the clinical predictors of postoperative AF using a prospectively collected database.Methods
A total of 418 patients underwent cardiovascular surgery and were enrolled in this study. The relationship between postoperative AF and perioperative factors was examined.Results
Postoperative AF occurred in 134 patients (32.1 %). A univariate analysis showed that an older age, hypertension, perioperative transfusion, use of cardiopulmonary bypass and thoracic aortic surgery were significantly associated with postoperative AF. The incidence of fibrillation was 49.4 % (39/79) in patients having aortic surgery. A multivariate analysis revealed that an older age, transfusion, and aortic surgery were all independent predictors of postoperative AF.Conclusions
An older age, transfusion, and aortic surgery are strong independent predictors of postoperative AF. These findings help to identify high-risk patients for AF after cardiovascular surgery. Careful perioperative management is required for older patients undergoing aortic surgery with cardiopulmonary bypass. 相似文献89.
Takuya Ishimoto Takayoshi Nakano Yukichi Umakoshi Masaya Yamamoto Yasuhiko Tabata 《Journal of bone and mineral research》2013,28(5):1170-1179
The aim of the present study was to assess the bone regeneration process in defects introduced into rabbit long bones, which were regenerated with controlled release of recombinant bone morphogenetic protein‐2 (rBMP‐2). The orientation of the biological apatite (BAp) c‐axis and bone mineral density (BMD) were compared as predictors of bone mechanical function. A 20‐mm‐long defect was introduced in rabbit ulnas, and 17 µg of rBMP‐2 was controlled‐released into the defect using a biodegradable gelatin hydrogel as the carrier. In the bone regeneration process, two characteristic phases may have been governed by different factors. First, new bone formation actively occurred, filling the bone defect with newly formed bone tissue and increasing the BMD. This process was regulated by the strong osteoinductive capacity of rBMP‐2. Second, after filling of the defect and moderate BMD restoration, preferential BAp c‐axis orientation began to increase, coincident with initiation of remodeling. In addition, the BAp c‐axis orientation, rather than BMD, was strongly correlated with Young's modulus, an important index of bone mechanical function, particularly in the later stage of bone regeneration. Thus, preferential BAp c‐axis orientation is a strong determinant and predictor of the mechanical function of tissue‐engineered bone. Therefore, analysis of BAp preferential c‐axis orientation in addition to measurement of BMD is crucial in assessment of bone mechanical function. © 2013 American Society for Bone and Mineral Research © 2013 American Society for Bone and Mineral Research 相似文献
90.
Yoshihiro Noyama Takayoshi Nakano Takuya Ishimoto Takashi Sakai Hideki Yoshikawa 《BONE》2013,52(2):659-667
We proposed a novel surface modification for an artificial hip joint stem from the viewpoint of maintenance and establishment of appropriate bone function and microstructure, represented by the preferred alignment of biological apatite (BAp) and collagen (Col). Oriented grooves were introduced into the proximal medial region of the femoral stem to control the principal stress applied to the bone inside the grooves, which is a dominant factor contributing to the promotion of Col/BAp alignment. The groove angle and the stem material were optimized based on the stress inside the grooves through a finite element analysis (FEA). Only the groove oriented proximally by 60° from the normal direction of the stem surface generated the healthy maximum principal stress distribution. The magnitude of the maximum principal stress inside the groove decreased with increasing the stem Young's modulus, while the direction of the stress did not largely changed. An in vivo implantation experiment showed that this groove was effective in inducing the new bone with preferential Col/BAp alignment along the groove depth direction which corresponded to the direction of maximum principal stress inside the groove. The anisotropic principal stress distribution and the oriented microstructure inside the groove are similar to those found in the femoral trabeculae; therefore, the creation of the oriented groove is a potent surface modification for optimizing implant design for a long-term fixation. 相似文献