全文获取类型
收费全文 | 49995篇 |
免费 | 5329篇 |
国内免费 | 364篇 |
专业分类
耳鼻咽喉 | 1020篇 |
儿科学 | 1250篇 |
妇产科学 | 1164篇 |
基础医学 | 5295篇 |
口腔科学 | 957篇 |
临床医学 | 5463篇 |
内科学 | 10078篇 |
皮肤病学 | 1109篇 |
神经病学 | 5239篇 |
特种医学 | 1795篇 |
外科学 | 9540篇 |
综合类 | 510篇 |
现状与发展 | 3篇 |
一般理论 | 35篇 |
预防医学 | 4045篇 |
眼科学 | 1359篇 |
药学 | 2745篇 |
中国医学 | 115篇 |
肿瘤学 | 3966篇 |
出版年
2024年 | 115篇 |
2023年 | 725篇 |
2022年 | 543篇 |
2021年 | 1174篇 |
2020年 | 1259篇 |
2019年 | 1002篇 |
2018年 | 1660篇 |
2017年 | 1335篇 |
2016年 | 1484篇 |
2015年 | 1536篇 |
2014年 | 2254篇 |
2013年 | 2759篇 |
2012年 | 3137篇 |
2011年 | 3197篇 |
2010年 | 2266篇 |
2009年 | 2315篇 |
2008年 | 2974篇 |
2007年 | 3038篇 |
2006年 | 2971篇 |
2005年 | 2797篇 |
2004年 | 2627篇 |
2003年 | 2470篇 |
2002年 | 2261篇 |
2001年 | 554篇 |
2000年 | 445篇 |
1999年 | 555篇 |
1998年 | 692篇 |
1997年 | 654篇 |
1996年 | 690篇 |
1995年 | 592篇 |
1994年 | 482篇 |
1993年 | 388篇 |
1992年 | 353篇 |
1991年 | 320篇 |
1990年 | 227篇 |
1989年 | 268篇 |
1988年 | 262篇 |
1987年 | 228篇 |
1986年 | 221篇 |
1985年 | 223篇 |
1984年 | 235篇 |
1983年 | 225篇 |
1982年 | 267篇 |
1981年 | 219篇 |
1980年 | 199篇 |
1979年 | 114篇 |
1978年 | 160篇 |
1977年 | 160篇 |
1976年 | 118篇 |
1975年 | 132篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
This paper reviews the published literature on a group of developmental disorders of the retina and retinal pigment epithelium which result in focal abnormalities in one or both eyes. They are often asymptomatic, found on routine examination and are generally non-progressive. Some are associated with other systemic abnormalities.Subject terms: Retinal diseases, Eye abnormalities 相似文献
2.
Laparoscopic surgery has several advantages over traditional surgery because it has been shown to be less invasive. The next logical step in the evolution of minimally invasive surgery may be to eliminate all abdominal incisions. The natural orifices provide a port of entry via the gastrointestinal tract to the peritoneal cavity. This approach would require the creation of a perforation, which is considered to be a major complication of endoscopy with significant morbidity and mortality. However, there are several recent studies that have described the technical feasibility and safety of a per‐oral transgastric approach to the peritoneal cavity using conventional endoscopes. Theoretically, this approach could reduce postoperative abdominal wall pain, wound infection, hernia formation, and adhesions. This article aims to summarize the current status of transgastric surgery, currently referred to as natural orifice transluminal endoscopic surgery (NOTES), and to address some of its future challenges. 相似文献
3.
4.
F Sebastiano G Di Gennaro V Esposito A Picardi R Morace A Sparano A Mascia C Colonnese G Cantore P P Quarato 《Clinical neurophysiology》2006,117(2):341-347
OBJECTIVES: To evaluate a novel method for localization of subdural electrodes in presurgical assessment of patients with drug-resistant focal epilepsy. METHODS: We studied eight consecutive patients with posterior epilepsy in whom subdural electrodes were implanted for presurgical evaluation. Electrodes were detected on post-implantation brain CT scans through a semiautomated procedure based on a MATLAB routine. Then, post-implantation CT scans were fused with pre-implantation MRI to localize the electrodes in relation to the underlying cortical structures. The reliability of this procedure was tested by comparing 3D-rendered MR images of the electrodes with electrode position as determined by intraoperative digital photography. RESULTS: In each patient, all electrodes could be correctly localized and visualized in a stereotactic space, thus allowing optimal surgery planning. The agreement between the procedure-generated images and the digital photographs was good according to two independent raters. The mean mismatch between the 3D images and the photographs was 2 mm. CONCLUSIONS: While our findings need confirmation on larger samples including patients with anterior epilepsy, this procedure allowed to localize subdural electrodes and to establish the spatial relationship of each electrode to the underlying brain structure, either normal or damaged, on brain convessity, basal and medial cortex. SIGNIFICANCE: Being simple, rapid, unexpensive, and reliable, this procedure holds promise to be useful to optimize epilepsy surgery planning. 相似文献
5.
Light emitting diodes for auramine O fluorescence microscopic screening of Mycobacterium tuberculosis. 总被引:1,自引:0,他引:1
R M Anthony A H J Kolk S Kuijper P R Klatser 《The international journal of tuberculosis and lung disease》2006,10(9):1060-1062
We describe the simple adaptation of a standard fluorescent microscope for illumination using a 'Royal Blue' Luxeon light emitting diode (LED) and demonstrate that this form of illumination is suitable for the detection of auramine O stained Mycobacterium spp. The low cost, low power consumption, safety and reliability of LEDs makes them attractive alternatives to mercury vapour lamps. 相似文献
6.
7.
8.
Anthony Z Faranesh Dara L Kraitchman Elliot R McVeigh 《Magnetic resonance in medicine》2006,55(5):1114-1123
The purpose of this work was to investigate the use of an intravascular contrast agent to determine perfusion kinetics in skeletal muscle. A two-compartment kinetic model was used to represent the flux of contrast agent between the intravascular space and extravascular extracellular space (EES). The relationship between the image signal-to-noise ratio (SNR) and errors in estimating permeability surface area product (Ktrans), interstitial volume (ve), and plasma volume (vp) for linear and nonlinear curve-fitting methods was estimated from Monte Carlo simulations. Similar results were obtained for both methods. For an image SNR of 60, the estimated errors in these parameters were 10%, 22%, and 17%, respectively. In vivo experiments were conducted in rabbits to examine physiological differences between these parameters in the soleus (SOL) and tibialis anterior (TA) muscles in the hind limb. Values for Ktrans were significantly higher in the SOL (3.2+/-0.9 vs. 2.0+/-0.5x10(-3) min-1), as were values for vp (3.4+/-0.8 vs. 2.1+/-0.7%). Differences in ve for the two muscles (8.7+/-2.2 vs. 8.5+/-1.6%) were not found to be significant. These results demonstrate that relevant physiological metrics can be calculated in skeletal muscle using MRI with an intravascular contrast agent. 相似文献
9.
Outcomes at 3 years of a prospective pilot study of Campath-1H and sirolimus immunosuppression for renal transplantation 总被引:2,自引:0,他引:2
Rolf N. Barth Christina A. Janus Christine A. Lillesand Nancy A. Radke John D. Pirsch Bryan N. Becker Luis A. Fernandez L. Thomas Chin Yolanda T. Becker Jon S. Odorico Anthony M. D''Alessandro Hans W. Sollinger Stuart J. Knechtle 《Transplant international》2006,19(11):885-892
Campath-1H (alemtuzumab) induction was used for renal transplantation in combination with sirolimus as immunosuppression. We previously reported a high (28%) rate of early rejection with this regimen, and now report 3-year outcomes. Twenty-nine patients were recipients of either deceased donor or non-HLA (Human Leukocyte Antigen) identical living donor primary renal allografts. Clinical parameters including infection, malignancy, kidney function, and kidney histology were followed prospectively for 3 years. Three-year cumulative graft and patient survival were 96% and 100%, respectively. Twenty patients were maintained on steroid-free immunosuppressive regimens, and 15 patients were maintained on monotherapy for immunosuppression (12 on sirolimus). No serious infectious complications were observed and two patients developed basal cell skin cancer. The 3-year results of our initial pilot study demonstrate good graft (96%) and patient (100%) outcomes. Campath-1H induction has yielded a high proportion of patients maintained on immunosuppressive monotherapy (57%) without serious infectious- and no malignancy-related complications. The reported regimen yielded novel insights into both Campath-1H and sirolimus therapy in renal transplantation. Because of the higher incidence of early rejection, we recommend a modified strategy of immunosuppression including a brief course of a calcineurin inhibitor. 相似文献
10.