全文获取类型
收费全文 | 55470篇 |
免费 | 4858篇 |
国内免费 | 3266篇 |
专业分类
耳鼻咽喉 | 538篇 |
儿科学 | 535篇 |
妇产科学 | 644篇 |
基础医学 | 7120篇 |
口腔科学 | 1092篇 |
临床医学 | 6853篇 |
内科学 | 8674篇 |
皮肤病学 | 753篇 |
神经病学 | 2990篇 |
特种医学 | 2473篇 |
外国民族医学 | 37篇 |
外科学 | 6121篇 |
综合类 | 7753篇 |
现状与发展 | 7篇 |
一般理论 | 2篇 |
预防医学 | 3458篇 |
眼科学 | 1559篇 |
药学 | 5509篇 |
44篇 | |
中国医学 | 2682篇 |
肿瘤学 | 4750篇 |
出版年
2024年 | 147篇 |
2023年 | 785篇 |
2022年 | 2167篇 |
2021年 | 2892篇 |
2020年 | 1930篇 |
2019年 | 1816篇 |
2018年 | 1953篇 |
2017年 | 1663篇 |
2016年 | 1786篇 |
2015年 | 2583篇 |
2014年 | 3211篇 |
2013年 | 2893篇 |
2012年 | 4619篇 |
2011年 | 4714篇 |
2010年 | 3002篇 |
2009年 | 2453篇 |
2008年 | 3185篇 |
2007年 | 3051篇 |
2006年 | 2832篇 |
2005年 | 2581篇 |
2004年 | 1861篇 |
2003年 | 1707篇 |
2002年 | 1492篇 |
2001年 | 1202篇 |
2000年 | 1227篇 |
1999年 | 1162篇 |
1998年 | 646篇 |
1997年 | 685篇 |
1996年 | 541篇 |
1995年 | 451篇 |
1994年 | 367篇 |
1993年 | 255篇 |
1992年 | 335篇 |
1991年 | 249篇 |
1990年 | 216篇 |
1989年 | 188篇 |
1988年 | 148篇 |
1987年 | 134篇 |
1986年 | 105篇 |
1985年 | 90篇 |
1984年 | 51篇 |
1983年 | 50篇 |
1982年 | 22篇 |
1981年 | 24篇 |
1980年 | 13篇 |
1979年 | 23篇 |
1978年 | 11篇 |
1973年 | 11篇 |
1971年 | 9篇 |
1969年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
脑外伤后脑干组织中血管内皮细胞及血浆蛋白分布改变的免疫?… 总被引:1,自引:0,他引:1
目的:探讨脑外伤后脑干组织中血脑屏障和神经细胞的病理学改变.方法:采用免疫组化染色显示人体脑干组织中的血管内皮细胞(CD31)和某些血浆蛋白(白蛋白及 IgM).结果:1.在正常脑干组织中, CD31阳性物呈连续的线条状,围成规则的血管腔,其周围无明显间隙;血浆蛋白位于血管内,未见到血浆/蛋白阳性神经细胞或神经纤维.2.脑外伤后,脑干中的 CD31阳性物呈不规则弯曲的小片段状,围成不规则的血管腔,其周围间隙明显增宽;同时可见到白蛋白及IgM阳性神经细胞和神经纤维.结论:脑外伤后,脑干组织中的血脑屏障受到了破坏,而且神经细胞也有不同程度的损伤. 相似文献
102.
103.
瞬间反应式二次谐波显像评价正常犬肝脏超声学造影的实验研究 总被引:2,自引:1,他引:1
目的:评价瞬间反应二次谐波显像(Transient response second harmonec imaging,TRSHI)对正常肝脏声学造影的增强效果及动态变化规律,并与常规连续二次谐波显像进行对比分析。方法:6只健康杂种犬 经外周静脉注射氟碳声学造影剂,分别用常规二次谐波显像和瞬间反应式二次谐波显像扫描肝脏。造影效果评价使用视觉评分和视频密度分析。结果:常规二次谐波显像有4次I级增强、4 相似文献
104.
105.
目的 总结可吸收内固定材料自身增强聚丙交脂(SR-PLLA)的临床应用体会。方法 采用波兰进口SR-PLLA螺钉、棒、线治疗四肢松质骨骨折22例,随访摄片观察骨折愈合情况,检查关节活动功能。结果 术后有两侧出现并发症,一例局部少量积液,经2次穿刺抽液加压包扎痊愈;一例患者过早去除石膏功能锻炼,螺钉松动滑出,经手术复位石膏外固定治愈,无感染或过敏等情况发生。结论 掌握可吸收材料的生物力学特点,并选择适当的病例,可以最大限度地发挥可吸收内固定材料的优势。 相似文献
106.
We have previously isolated a drug-resistant, [PC3(R)], variant of human prostate PC3 cell line, which showed significant resistance (>10-fold) to adriamycin. No known mechanisms of drug resistance were found; however, resistant cells expressed more bcl2, c-myc, and ms oncogenes compared to the sensitive cells. In this study, we found that buthionine sulfoximine (BSO), an inhibitor of gamma-glutamyl-cysteine synthetase, decreased glutathione levels by 80-90% in both cell lines. BSO treatment down-modulated Ras protein only in PC3(R) cells and caused a 4-fold sensitization of PC3(R) cells to adriamycin without affecting PC3(W) cells. Farnesol treatment also inhibited expression of Ras protein and concomitantly reversed adriamycin resistance in PC3(R) cells, indicating that altered levels of ras expression plays an important role in drug resistance in PC3(R) cells. 相似文献
107.
A 23-year-old male involved in a high-speed collision acquired, among other injuries, a wide fracture distraction at C2/C3. Reduction was delayed by an enlarging vertebral artery pseudo-aneurysm at the site of injury which was successfully treated by proximal endovascular occlusion with a detachable polymer-filled balloon. A traumatic arachnoid cyst or pseudomeningocele was also demonstrated at the injury site but intervention was not required. The treatment and outcome of these three uncommon injuries in the literature is reviewed and discussed. Given the severity of the injury, the absence of severe long-term neurological disability is notable. 相似文献
108.
109.
Our previous studies have demonstrated that supraspinal GABAergic receptors are differentially involved in the antinociception induced by morphine and beta-endorphin given intracerebroventricularly (i.c.v.) in the tail-flick and hot-plate tests. These two models employed a phasic, thermal nociceptive stimulus. The present study was designed to examine the possible involvement of supraspinal GABAergic receptors in opioid-induced antinociception in the formalin test. Morphine (1 microg) and beta-endorphin (1 microg) given i.c.v. displayed the almost complete inhibitory effects against the hyperalgesic response in both phases. Muscimol (75-100 ng) and baclofen (5-10 ng) injected i.c.v. produced the hypoalgesic response in the both phases. The hypoalgesic response induced by muscimol and baclofen observed during the second phase was more pronounced than that observed during the second phase. Baclofen (2.5 ng), at the dose which did not affect the hyperalgesic response, resulted in a significant reversal of the i.c.v. administered beta-endorphin-induced hypoalgesic response observed during the second, but not the first, phase. However, the hypoalgesic response induced by i.c.v. administered morphine was not changed by the same dose of muscimol or baclofen injected i.c.v. Our results indicate that, at the supraspinal level, GABA(B)receptors appear to be involved in the modulation of antinociception induced by supraspinally administered beta-endorphin, but not morphine, in the formalin test model. 相似文献
110.
Chiu HJ Tsai SJ Chen JY Lin CY Bai YM Song HL Lai HC Hong CJ 《Psychiatry research》1999,87(2-3):245-248
We investigated the association between schizophrenic psychosis and an intronic polymorphism of the presenilin-1 (PS1) gene in a Chinese population. Schizophrenic and control groups had similar PS1 genotype distributions and allele frequencies, indicating that this polymorphism may not be involved in the development of schizophrenia. 相似文献