全文获取类型
收费全文 | 8340篇 |
免费 | 455篇 |
国内免费 | 92篇 |
专业分类
耳鼻咽喉 | 54篇 |
儿科学 | 202篇 |
妇产科学 | 647篇 |
基础医学 | 933篇 |
口腔科学 | 148篇 |
临床医学 | 939篇 |
内科学 | 1717篇 |
皮肤病学 | 83篇 |
神经病学 | 524篇 |
特种医学 | 344篇 |
外科学 | 1077篇 |
综合类 | 185篇 |
预防医学 | 431篇 |
眼科学 | 74篇 |
药学 | 609篇 |
中国医学 | 116篇 |
肿瘤学 | 804篇 |
出版年
2023年 | 35篇 |
2022年 | 70篇 |
2021年 | 174篇 |
2020年 | 92篇 |
2019年 | 157篇 |
2018年 | 252篇 |
2017年 | 172篇 |
2016年 | 164篇 |
2015年 | 217篇 |
2014年 | 249篇 |
2013年 | 401篇 |
2012年 | 574篇 |
2011年 | 585篇 |
2010年 | 395篇 |
2009年 | 336篇 |
2008年 | 500篇 |
2007年 | 553篇 |
2006年 | 545篇 |
2005年 | 446篇 |
2004年 | 392篇 |
2003年 | 322篇 |
2002年 | 317篇 |
2001年 | 264篇 |
2000年 | 275篇 |
1999年 | 207篇 |
1998年 | 82篇 |
1997年 | 86篇 |
1996年 | 83篇 |
1995年 | 54篇 |
1994年 | 67篇 |
1993年 | 43篇 |
1992年 | 132篇 |
1991年 | 94篇 |
1990年 | 73篇 |
1989年 | 56篇 |
1988年 | 62篇 |
1987年 | 53篇 |
1986年 | 59篇 |
1985年 | 38篇 |
1984年 | 40篇 |
1983年 | 17篇 |
1982年 | 19篇 |
1981年 | 20篇 |
1980年 | 11篇 |
1979年 | 16篇 |
1978年 | 8篇 |
1975年 | 10篇 |
1973年 | 7篇 |
1972年 | 7篇 |
1971年 | 10篇 |
排序方式: 共有8887条查询结果,搜索用时 234 毫秒
31.
Joung-Liang Lan Show-Jan Chou Der-Yuan Chen Yi-Hsing Chen Tsu-Yi Hsieh Mariano Young 《台湾医志》2004,103(8):618-623
BACKGROUND AND PURPOSE: Etanercept (Enbrel), a recombinant tumor necrosis factor receptor fusion protein, has been shown to be effective in the treatment of patients with rheumatoid arthritis (RA). The purpose of this study was to compare the efficacy and safety of etanercept in combination with methotrexate (MTX) and MTX alone in Taiwanese patients with active RA. METHODS: In this double-blind study, 58 patients with active RA who were maintained on MTX therapy at a stable dose of 12.5 to 20 mg per week for 4 weeks were randomized to receive either etanercept 25 mg (n = 29) or placebo (n = 29) by subcutaneous injection twice weekly over a period of 12 weeks. The primary endpoint was the reduction of tender and swollen joint counts by 20% (ACR 20), 50% (ACR 50), and 70% (ACR 70) as determined by the American College of Rheumatology criteria at the 12th week. RESULTS: The addition of etanercept to MTX resulted in a greater reduction in the number of tender (7.00 vs 2.45, p = 0.012) and swollen joints (8.55 vs 3.86, p = 0.017), and in serum levels of C-reactive protein (1.26 mg/dL vs 0.45 mg/dL, p = 0.014) compared to MTX alone after 12 weeks of therapy. In addition, the global assessment of disease activity by both physicians and patients, duration of morning stiffness, pain visual analog scale score, and Health Assessment Questionnaire were all improved by etanercept plus MTX therapy. Results for the overall improvement in disease activity assessed by ACR 20 (90% vs 34%), ACR 50 (66% vs 10%) and ACR 70 (24% vs 0%) all favored the etanercept plus MTX group. However, the adverse events were comparable between the 2 treatment groups. CONCLUSION: Etanercept in combination with MTX was well tolerated and provided significantly more clinical benefit than MTX alone in Taiwanese patients with active RA. 相似文献
32.
Lymph node metastases: safety and effectiveness of MR imaging with ultrasmall superparamagnetic iron oxide particles--initial clinical experience 总被引:14,自引:0,他引:14
33.
WIF1, a component of the Wnt pathway, is down-regulated in prostate, breast, lung, and bladder cancer 总被引:19,自引:0,他引:19
34.
This study examined the acquisition and transfer of a fine motor skill, namely the rotary pursuit, in 99 patients with Alzheimer's disease (AD) and 100 normal controls (NCs). To identify optimal learning strategies, the authors had participants practice the rotary pursuit under constant, blocked, random, or no training conditions. Transfer was assessed using speeds that were different from those practiced during acquisition. AD patients and NCs receiving constant practice outperformed their peers in the blocked and random conditions during acquisition. Whereas all 3 types of practice facilitated transfer in the NCs, AD patients only benefited from constant practice. The inability of the AD patients to benefit from variable practice suggests that these individuals may have difficulty accessing and/or forming motor schemas. 相似文献
35.
In computed tomography (CT), the beam hardening effect has been known to be one of the major sources of deterministic error that leads to inaccuracy and artifact in the reconstructed images. Because of the polychromatic nature of the x-ray source used in CT and the energy-dependent attenuation of most materials, Beer's law no longer holds. As a result, errors are present in the acquired line integrals or measurements of the attenuation coefficients of the scanned object. In the past, many studies have been conducted to combat image artifacts induced by beam hardening. In this paper, we present an iterative beam hardening correction approach for cone beam CT. An algorithm that utilizes a tilted parallel beam geometry is developed and subsequently employed to estimate the projection error and obtain an error estimation image, which is then subtracted from the initial reconstruction. A theoretical analysis is performed to investigate the accuracy of our methods. Phantom and animal experiments are conducted to demonstrate the effectiveness of our approach. 相似文献
36.
37.
Tsang-Ming Ko Fon-Jou Hsieh Pi-Mei Hsu Tzu-Yao Lee 《American journal of medical genetics. Part A》1991,39(3):317-320
α-Thalassemia hydrops fetalis is a common disorder in Taiwan. The condition causes perinatal death and many maternal obstetrical complications. In order to determine the molecular defects of this condition in Chinese, 87 unrelated families with this disorder were collected in the past 4 years. The molecular defects were studied by Southern blotting and DNA hybridization with φζ1-globin gene and LO (a 0.4 kb BamHI/EcoRI fragment in the 5′ flanking region of the ζ2-globin gene) probes. Eighty-one (93.1%) fetuses had homozygous Southeast Asian deletion (– –SEA/– –SEA). Five (5.7%) fetuses were compound heterozygotes for the Southeast Asian deletion and Thailand deletion (– –SEA/– –THAI). The remaining fetus was a compound heterozygote for the Southeast Asian deletion and an uncharacterized nondeletional defect (– –SEA/(αα)Th). The molecular defects of α-thalassemia hydrops fetalis in Chinese are heterogeneous. This fact has important implications for genetic counseling and prenatal diagnosis. 相似文献
38.
An in vivo model has been developed for chronic observation of the effects of ischemia on cortical bone remodeling and perfused vascularity. Diaphragm occluders were implanted around the right common iliac artery of four rabbits and inflated to produce 10 h of ischemia to the limb. Microcirculation was monitored with intravital microscopy of injected fluorescent microspheres and FITC-Dextran 70 through a bone window, the tibial bone chamber implant (BCI). Bone resorption and apposition in the BCI were indicated with mineralization dyes. Between 2 and 12 h following release of the occluder, secondary ischemia/no-reflow and other evidence of reperfusion injury were observed. Vessel damage was suggested by abnormally high leakage of FITC-D70 from the few vessels perfused during secondary ischemia. In the weeks following occluder release perfused vasculature increased beyond pre-occlusion levels. Net bone resorption reached a maximum when vascularity passed normal levels. In order to further validate the arterial occlusion model for osteonecrosis, techniques for (1) confirming bone death and (2) detecting increased leukocyte adherence to endothelial cells were added. The dead cell stain Ethidium homodimer-1 was used to tag dead osteocytes immediately after occlusion and produced a measure designated osteonecrosis index. To detect leukocytes adhering to vessel walls, carboxyfluorescein diacetate, succinimidyl ester was injected at occluder release. An increase in the number of adherent leukocytes was detected. © 1999 Biomedical Engineering Society.
PAC99: 8764Rr, 8717-d, 8719Tt 相似文献
39.
40.