全文获取类型
收费全文 | 29865篇 |
免费 | 2829篇 |
国内免费 | 2185篇 |
专业分类
耳鼻咽喉 | 229篇 |
儿科学 | 411篇 |
妇产科学 | 344篇 |
基础医学 | 3415篇 |
口腔科学 | 535篇 |
临床医学 | 3971篇 |
内科学 | 4530篇 |
皮肤病学 | 271篇 |
神经病学 | 1455篇 |
特种医学 | 1284篇 |
外国民族医学 | 12篇 |
外科学 | 3424篇 |
综合类 | 4918篇 |
现状与发展 | 6篇 |
一般理论 | 3篇 |
预防医学 | 1918篇 |
眼科学 | 683篇 |
药学 | 3206篇 |
27篇 | |
中国医学 | 1607篇 |
肿瘤学 | 2630篇 |
出版年
2024年 | 97篇 |
2023年 | 449篇 |
2022年 | 1119篇 |
2021年 | 1389篇 |
2020年 | 1046篇 |
2019年 | 943篇 |
2018年 | 981篇 |
2017年 | 926篇 |
2016年 | 954篇 |
2015年 | 1331篇 |
2014年 | 1636篇 |
2013年 | 1486篇 |
2012年 | 1969篇 |
2011年 | 2368篇 |
2010年 | 1504篇 |
2009年 | 1173篇 |
2008年 | 1518篇 |
2007年 | 1587篇 |
2006年 | 1535篇 |
2005年 | 1487篇 |
2004年 | 1134篇 |
2003年 | 1141篇 |
2002年 | 1029篇 |
2001年 | 877篇 |
2000年 | 801篇 |
1999年 | 754篇 |
1998年 | 445篇 |
1997年 | 512篇 |
1996年 | 341篇 |
1995年 | 301篇 |
1994年 | 236篇 |
1993年 | 192篇 |
1992年 | 231篇 |
1991年 | 212篇 |
1990年 | 188篇 |
1989年 | 167篇 |
1988年 | 135篇 |
1987年 | 141篇 |
1986年 | 123篇 |
1985年 | 77篇 |
1984年 | 51篇 |
1983年 | 28篇 |
1982年 | 16篇 |
1981年 | 17篇 |
1980年 | 26篇 |
1979年 | 46篇 |
1978年 | 22篇 |
1976年 | 12篇 |
1975年 | 18篇 |
1974年 | 20篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
J Lin Z-H Liu W Chen Z Jia D Pan Y Fu F Zhang A Xu 《European journal of immunogenetics》2002,29(4):335-336
A new DRB1 allele, DRB1*0902, has been identified in an individual of the Jing ethnic minority. Its sequence was confirmed by sequencing of PCR products and clones. This allele differed by three nucleotides from DRB1*09012 at positions 157, 161 and 166, and resulted in amino acid motif substitution from VAES to DAEY. 相似文献
32.
同型半胱氨酸对胚胎海马神经元细胞的影响 总被引:1,自引:1,他引:0
目的 观察同型半胱氨酸(homocysteine,HCY)对海马神经元细胞分化和增殖的作用机理。方法 采用大鼠胚胎海马神经元细胞进行体外培养。观察不同浓度的HCY(0.01、0.1、1.0、10.0、100.0)mmol/L对细胞分化和增殖的影响。结果 随着剂量的增加.同型半胱氨酸对胚胎海马神经元细胞分化和增殖具有抑制作用,并用流式细胞术分析证明对脂质过氧化(LPO)的影响而使得神经元蛋白质含量增高。结论 同型半胱氨酸可抑制胚胎海马神经元细胞分化和增殖的影响,HCY可能在导致神经管畸形的过程起着重要作用。 相似文献
33.
L M Tran R Mark Y S Fu T Calcaterra G Juillard 《American journal of clinical oncology》1992,15(3):222-225
During a 26-year period (1961-1987), a total of 18 patients with primary non-Hodgkin's lymphoma (NHL) of the paranasal sinuses and nasal cavity received radiation therapy at (University of California at Los Angeles) UCLA Medical Center. At the time of diagnosis and using the available diagnostic methods, none of these patients had clinically detectable disease beyond the paranasal sinuses. All 18 patients were staged IE by the Ann-Arbor system. When the patients were staged according to the AJC staging system from epithelial tumors, half presented with advanced T3-4 disease. Diffuse histiocytic lymphoma was the most common histology (eight cases) and maxillary sinus, the most common site of origin (11 cases). All nine T1-2 tumors received radiation therapy alone, while radiation and chemotherapy was used in seven of nine advanced T3-4 staged tumors. The mean follow-up was 71 months. At last follow-up, eight of nine T1-2 patients were rendered disease-free. In contrast, only four of nine T3-4 patients had long-term disease-free survival. Seventy-five percent of the failure occurred within 2 years. Radiation therapy alone achieves high local control in small tumors (T1-2), while large tumors (T3-4) require aggressive combined treatment, i.e., radiation and chemotherapy. 相似文献
34.
Masataka Sakane Ross J. Fox Savio L-Y. Woo Glen A. Livesay Guoan Li Freddie H. Fu 《Journal of orthopaedic research》1997,15(2):285-293
The anterior cruciate ligament has a complex fiber anatomy and is not considered to be a uniform structure. Current anterior cruciate ligament reconstructions succeed in stabilizing the knee, but they neither fully restore normal knee kinematics nor reproduce normal ligament, function. To improve the outcome of the reconstruction, it may be necessary to reproduce the complex function of the intact anterior cruciate ligament in the replacement graft. We examined the in situ forces in nine human anterior cruciate ligaments as well as the force distribution between the anteromedial and posterolateral bundles of the ligament in response to applied anterioi tibial loads ranging from 22 to 110 N at knee flexion angles of 0–90°. The analysis was performed using a robotic manipulator in conjunction with a universal force-moment sensor. The in situ forces were determined with no device attached to the ligament, while the knee was permitted to move freely in response to the applied loads. We found that the in situ forces in the anterior cruciate ligament ranged from 12.8 ± 7.3 N under 22 N of anterior tibial load applied at 90° of knee flexion to 110.6 ± 14.8 N under 110 N of applied load at 15° of flexion. The magnitude of the in situ force in the posterolateral bundle was larger than that in the anteromedial bundle at knee flexion angles between 0 and 45°, reaching a maximum of 75.2 ± 18.3 N at 15° of knee flexion under an anterior tibial load of 110 N. The magnitude of the in situ force in the posterolateral bundle was significantly affected by knee flexion angle and anterior tibial load in a fashion remarkably similar to that seen in the anterior cruciate ligament. The magnitude of the in situ force in the anteromedial bundle, in contrast, remained relatively constant, not changing with flexion angle. Significant differences in the direction of the in situ force between the anteromedial bundle and the posterolateral bundle were found only at flexion angles of 0 and 60° and only under applied anterior tibial loads greater than 66 N. We have demonstrated the nonuniformity of the anterior cruciate ligament under unconstrained anterior tibial loads. Our data further suggest that in order for the anterior cruciate ligament replacement graft to reproduce the in situ forces of the normal anterior cruciate ligament, reconstruction techniques should take into account the role of the posterolateral bundle in addition to that of the anteromedial bundle. 相似文献
35.
36.
37.
38.
目的:研究阻断CD86协同刺激分子对自然流产模型孕鼠母胎界面Caspase-3、laminin B和PAI-1的表达及对妊娠结局的影响。方法:实验组于妊娠第4.5天腹腔注射大鼠抗小鼠CD86单抗,实验对照组注射大鼠同型IgG2b,正常妊娠组不作任何处理。于妊娠第13.5天计算胚胎吸收率,用免疫组化测定Caspase-3、laminin B和PAI-1的表达,并进行图像分析、检测免疫组化染色灰度值(A)。结果:①实验组的胚胎吸收率显著低于实验对照组(P<0.05);②实验组中Caspase-3蛋白灰度值明显高于实验对照组(P<0.05),实验组中laminin B和PAI-1蛋白灰度值均明显低于实验对照组(P<0.05)。结论:妊娠早期阻断CD86协同刺激分子可使母胎界面中的Caspase-3、laminin B和PAI-1分别通过各自不同的途径发挥免疫耐受作用并且使自然流产模型孕鼠的胚胎吸收率降低至正常妊娠水平。 相似文献
39.
40.
目的 探讨原发性十二指肠肿瘤 (PTD)的诊断和治疗。方法 回顾性分析我院 1995 2 0 0 3年间 4 3例PTD的临床资料。结果 十二指肠镜确诊率为 85 .7% ,B超检查的阳性率为 5 5 .6 % ,CT检查阳性率为 80 % ,肿瘤位于十二指肠降段 (乳头部或其对侧 ) 35例 ,占 81.4 % ,2例平滑肌瘤切除术后存活 5年以上 ,1例乳头部腺瘤行肿瘤局部切除术后半年出现黄疸 ,病因不详。 4例间质瘤均健在且生存 16 2 1个月 ,36例原发性十二指肠恶性肿瘤中胰头十二指肠切除 18例 ,节段切除 1例 ,手术切除率为 5 1.2 %。结论 B超、CT、纤维十二指肠镜检查是诊断PTD的主要手段。手术切除是最基本有效的治疗方法。对于良性肿瘤可行局部肿瘤切除、十二指肠节段切除或经内镜切除。对于恶性肿瘤 ,胰十二指肠切除术是首选术式。 相似文献