全文获取类型
收费全文 | 115311篇 |
免费 | 11221篇 |
国内免费 | 8336篇 |
专业分类
耳鼻咽喉 | 929篇 |
儿科学 | 1255篇 |
妇产科学 | 1302篇 |
基础医学 | 13269篇 |
口腔科学 | 2241篇 |
临床医学 | 15749篇 |
内科学 | 16287篇 |
皮肤病学 | 1180篇 |
神经病学 | 5877篇 |
特种医学 | 4266篇 |
外国民族医学 | 73篇 |
外科学 | 10964篇 |
综合类 | 20656篇 |
现状与发展 | 38篇 |
一般理论 | 6篇 |
预防医学 | 7750篇 |
眼科学 | 3244篇 |
药学 | 12535篇 |
103篇 | |
中国医学 | 7519篇 |
肿瘤学 | 9625篇 |
出版年
2024年 | 533篇 |
2023年 | 2301篇 |
2022年 | 5434篇 |
2021年 | 6628篇 |
2020年 | 5015篇 |
2019年 | 4094篇 |
2018年 | 4187篇 |
2017年 | 3964篇 |
2016年 | 3512篇 |
2015年 | 5493篇 |
2014年 | 6521篇 |
2013年 | 5764篇 |
2012年 | 8605篇 |
2011年 | 9465篇 |
2010年 | 5933篇 |
2009年 | 4557篇 |
2008年 | 5663篇 |
2007年 | 5927篇 |
2006年 | 5740篇 |
2005年 | 5616篇 |
2004年 | 3567篇 |
2003年 | 3455篇 |
2002年 | 2924篇 |
2001年 | 2513篇 |
2000年 | 2561篇 |
1999年 | 2818篇 |
1998年 | 1852篇 |
1997年 | 1750篇 |
1996年 | 1338篇 |
1995年 | 1161篇 |
1994年 | 967篇 |
1993年 | 662篇 |
1992年 | 806篇 |
1991年 | 670篇 |
1990年 | 633篇 |
1989年 | 523篇 |
1988年 | 441篇 |
1987年 | 388篇 |
1986年 | 277篇 |
1985年 | 207篇 |
1984年 | 110篇 |
1983年 | 87篇 |
1982年 | 47篇 |
1981年 | 50篇 |
1980年 | 32篇 |
1979年 | 46篇 |
1978年 | 6篇 |
1977年 | 4篇 |
1974年 | 5篇 |
1966年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
A multivariate study of protective effects of Zn and Cu against nephrotoxicity induced by cadmium metallothionein in rats. 总被引:3,自引:0,他引:3
X Y Liu T Y Jin G F Nordberg S R?nnar M Sj?str?m Y Zhou 《Toxicology and applied pharmacology》1992,114(2):239-245
Factorial experimental design was used to study the protective effects of Zn and Cu on cadmium-metallothionein(CdMT)-induced nephrotoxicity in male Wistar rats. In the factorial design two levels of Zn (0 and 25 mg/kg body weight), two levels of Cu (0 and 12.5 mg/kg), and two levels of CdMT (0.1 and 0.4 mg of Cd/kg) were used as varied factors. The factorial design was complemented with a center point with all three variables at an intermediate setting, i.e., Zn at 12.5 mg/kg, Cu at 6.25 mg/kg, and CdMT at 0.25 mg Cd/kg. Each of the nine combinations of settings was administered to one of nine groups with six rats in each. Zn and Cu were injected sc 24 hr prior to the injection of CdMT. The concentrations of protein and Ca in urine and Ca in renal cortex were used as effects. The relationship between the experimental design settings and the effects were modeled with multiple regression. The multiple regression analysis revealed that for the high dose of CdMT (i) the enhanced values of protein in urine caused by CdMT injection could be more efficiently reduced by Zn than by Cu, and (ii) excessive Ca in urine and renal cortex could be more efficiently reduced by Cu than by Zn. No significant synergism or antagonism between Cu and Zn was found. These models can be used to estimate the dose levels of Zn and Cu which will reduce the toxic effects of CdMT. The treatment of 20.4 mg/kg Zn, for example, will reduce the effects of 0.4 mg Cd/kg as CdMT on protein in urine, and 2.8 mg/kg Cu will reduce the Ca in urine to the levels of those caused by 0.25 mg Cd/kg (no Zn and Cu). Similarly, the effect of 0.4 mg Cd/kg on Ca level in renal cortex can be reduced to that of 0.28 mg Cd/kg as CdMT by 7.98 mg Cu/kg, which is three times as efficient as Zn. The obtained results might be of importance in understanding the mechanism of cadmium toxicity and the potential risk to the health of the population exposed to cadmium occupationally or environmentally. 相似文献
52.
Generation of dendritic cells in vitro from peripheral blood mononuclear cells with granulocyte-macrophage-colony-stimulating factor, interleukin-4, and tumor necrosis factor-alpha for use in cancer immunotherapy. 总被引:8,自引:0,他引:8 下载免费PDF全文
OBJECTIVE: The purpose of the study was to characterize the requirements in terms of precursors, developmental pathways, and media for the generation of large numbers of mature dendritic cells (DC) under conditions acceptable for use in adjuvant, active immunotherapy strategies for surgically treated malignancies. SUMMARY BACKGROUND DATA: Although limited previously by the small numbers accessible, DC-based immunotherapies for malignancy have become more realistic with the development of methods for efficiently generating larger numbers of DC from peripheral blood mononuclear cells (PBMC) in vitro, but these methods rely on clinically unacceptable culture conditions (such as inclusion of fetal bovine serum), necessitating the development of methods for generating functionally equivalent DC in serum-free conditions. METHODS: Plastic-adherent PBMC (from healthy donors and patients with cancer) were incubated for 7 days with granulocyte-macrophage-colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4) with and without tumor necrosis factor-alpha (TNF-alpha) in fetal bovine serum-containing and serum-free media and were analyzed by Wright's stain for morphology, flow cytometry for phenotype, and mixed lymphocyte reaction for allostimulatory function. RESULTS: Growth in either serum-containing or serum-free media supplemented with GM-CSF and IL-4 yielded a similarly heterogeneous population of cells, 6% to 10% of which had the morphology (large cells with thin projections), immunophenotype (including CD83+), and function of mature DC. Tumor necrosis factor-alpha significantly augmented the number of these mature DC, whereas preculture depletion of CD14+ PBMC virtually eliminated them. CONCLUSIONS: Generation of mature DC in the authors' serum-free clinically applicable conditions is similar to serum-containing conditions and requires CD14+ precursors, differentiation through a CD14-CD83- immature stage under the influence of GM-CSF and IL-4, and maturation into a CD83+ DC under the influence of TNF-alpha. 相似文献
53.
Tongqiao Huoxue Tang and Buyang Huanwu Tang for Treatment of Vascular Dementia -A report of 36 Cases
To study the effects of Tongqiao Huoxue Tang (通窍活血汤) and Buyang Huanwu Tang (补阳还五汤) onvascular dementia (VaD), 36 VaD patients in thetreatment group were treated with the two decoctions,which were compared with 28 cases in a controlgroup treated with Duxil. 相似文献
54.
本文报道100例原发全身性癫痫家系的遗传流行病学研究结果。先证者一级亲属患病率为6.86%,二级亲属为1.03%;分别是对照组一级亲属的13.83倍和2.08倍。原发全身性癫痫的遗传度为:一级亲属0.7521±0.0678,二级亲属0.3592±0.0746;加权平均0.5743±0.0502。说明遗传因素起重要作用。发病年龄影响因素分析表明:原发全身性癫痫有一定年龄依从性。EEG家系分析显示,该型癫痫一级亲属癫痫样放电明显高于对照组一级亲属,提示癫痫样放电的遗传倾向。 相似文献
55.
角膜溃疡穿孔的修复与修复材料的选择 总被引:2,自引:0,他引:2
总结21例用不同材料修复角膜穿孔的病例,修复材料分别为结膜瓣、硅胶板、断层自体皮片和同种异体角膜。结膜瓣遮盖仅2/3保存眼球,愈合后视力差,并发症多;硅胶板可在穿孔大、情况紧急时作暂时封孔保存眼球之用;自体断层皮片术后不久即溶解,角膜移植者7眼中6眼保存了眼球,且有5例植片透明,视力0.1以上。 相似文献
56.
Treatment of hemophilia A by living mother-to-son splenic transplantation. First case report in the world. 总被引:4,自引:0,他引:4
A case of severe hemophilia A was treated by living mother-to-son splenic transplantation. The recipient was a 9-year-old boy. After splenic transplantation, the level of blood factor VIII:C was increased, and no spontaneous hemorrhage occurred. The boy was followed up for over two years. This is a case of spleen allotransplantation with the longest function in the world.
相似文献
57.
58.
59.
微创手术治疗高血压脑出血 总被引:10,自引:0,他引:10
目的 探讨微创手术治疗高血压脑出血的临床疗效。方法 132例高血压脑出血分成微创手术组(68例)和传统开颅手术组(64例),分析两组手术的特点和手术时机,比较两组手术治疗的疗效。结果 微创组术后GOS良好23例、中残24例、重残9例、植物生存3例、死亡9例;传统组术GOS良好16例、中残15例、重残12例、植物生存6例、死亡15例。两组超早期或早期手术均有良好的预后,而微创组效果更佳。结论 微创手术治疗高血压脑出血能明显提高临床疗效,降低病死率。 相似文献
60.
板股韧带的MRI研究及临床意义 总被引:1,自引:0,他引:1
目的 明确板股韧带正常MRI表现 ,建立由它所致假撕裂与外侧半月板后角真撕裂的鉴别方法。资料与方法 采用 6 0侧正常膝进行矢状和冠状位MR扫描 ,观察板股韧带的MRI表现。结果 板股韧带显示率为88.3% (5 3侧 ) ,其中板股前韧带为 2 6 .7% (16侧 )、板股后韧带为 86 .7% (5 2侧 )和两条韧带同时存在为 2 3.3% (14侧 )。板股韧带在矢状像上表现为位于后交叉韧带前或后方的类圆形或短棒状低信号结构 ,而在冠状像上表现为自外侧半月板后角至股骨内侧髁外侧面的条带样低信号结构。在矢状像上 ,5 2 .8% (2 8/5 3)板股韧带与外侧半月板后角之间显示出一线样高信号 ,被称为假撕裂 ,易与外侧半月板后角撕裂混淆。但假撕裂仅有两种走行方向即后下斜行 (2 1/2 8)或垂直方向 (7/2 8)。结论 根据假撕裂位置、方向以及冠状像和连续矢状面的观察 ,可正确区分外侧半月板后角真假撕裂 相似文献