全文获取类型
收费全文 | 67230篇 |
免费 | 5496篇 |
国内免费 | 4866篇 |
专业分类
耳鼻咽喉 | 431篇 |
儿科学 | 1735篇 |
妇产科学 | 751篇 |
基础医学 | 12101篇 |
口腔科学 | 1310篇 |
临床医学 | 5804篇 |
内科学 | 9473篇 |
皮肤病学 | 932篇 |
神经病学 | 4103篇 |
特种医学 | 1673篇 |
外国民族医学 | 29篇 |
外科学 | 3246篇 |
综合类 | 14083篇 |
现状与发展 | 24篇 |
一般理论 | 3篇 |
预防医学 | 3741篇 |
眼科学 | 1126篇 |
药学 | 6002篇 |
5篇 | |
中国医学 | 3246篇 |
肿瘤学 | 7774篇 |
出版年
2024年 | 167篇 |
2023年 | 742篇 |
2022年 | 1587篇 |
2021年 | 2081篇 |
2020年 | 1912篇 |
2019年 | 1792篇 |
2018年 | 1706篇 |
2017年 | 1963篇 |
2016年 | 2266篇 |
2015年 | 2283篇 |
2014年 | 3510篇 |
2013年 | 4577篇 |
2012年 | 3738篇 |
2011年 | 4562篇 |
2010年 | 3666篇 |
2009年 | 3724篇 |
2008年 | 3905篇 |
2007年 | 4244篇 |
2006年 | 4020篇 |
2005年 | 3721篇 |
2004年 | 3337篇 |
2003年 | 2922篇 |
2002年 | 2539篇 |
2001年 | 2328篇 |
2000年 | 1985篇 |
1999年 | 1648篇 |
1998年 | 1402篇 |
1997年 | 1200篇 |
1996年 | 872篇 |
1995年 | 758篇 |
1994年 | 572篇 |
1993年 | 378篇 |
1992年 | 293篇 |
1991年 | 236篇 |
1990年 | 218篇 |
1989年 | 144篇 |
1988年 | 115篇 |
1987年 | 81篇 |
1986年 | 68篇 |
1985年 | 86篇 |
1984年 | 55篇 |
1983年 | 32篇 |
1982年 | 43篇 |
1981年 | 29篇 |
1980年 | 22篇 |
1979年 | 19篇 |
1978年 | 14篇 |
1977年 | 9篇 |
1976年 | 6篇 |
1973年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Severe myoclonic epilepsy (SMEI) or Dravet syndrome is caused by mutations of the SCN1A gene that encodes voltage-gated sodium channel alpha-1 subunit. Recently, we generated and characterized a knock-in (KI) mice with an SCN1A nonsense mutation that appeared in three independent SMEI patients. The SCN1A-KI mice well reproduced the SMEI disease phenotypes. Both homozygous and heterozygous knock-in mice developed epileptic seizures within the first postnatal month. In heterozygous knock-in mice, trains of evoked action potentials in inhibitory neurons exhibited pronounced spike amplitude decrement late in the burst but not in pyramidal neurons. We further showed that in wild-type mice the Nav1.1 protein is expressed dominantly in axons and moderately in somata of parbalbumin (PV) – positive inhibitory interneurons. Our immunohistochemical observations of the Nav1.1 are clearly distinct to the previous studies, and our findings has corrected the view of the Nav1.1 protein distribution. The data indicate that Nav1.1 plays critical roles in the spike output from PV interneurons and further, that the specifically altered function of these inhibitory circuits may contribute to epileptic seizures in the mice. These information should contribute to the understanding of molecular pathomechanism of SMEI and to develop its effective therapies. 相似文献
12.
13.
Regulation of erythropoietin production 总被引:6,自引:0,他引:6
14.
高度近视的病因学研究进展 总被引:9,自引:0,他引:9
高度近视发生的内因、外因,包括遗传倾向,相关基因定位,巩膜胶原白体免疫学说,视网膜生物活性物质失调学说,环境因素等,本研究就这些因素对高度近视发病的影响做一综述。现统一的认识有:①高度近视具有明显的遗传倾向。②迄今为止,已找到4个高度近视相关基因,它们的遗传方式均为常染色体显性遗传。③高度近视的巩膜组织病理改变和胶原代谢障碍引发了人们对高度近视免疫相关基因的深入研究。已发现HLAⅡ类基因与部分高度近视具有相关性。④视网膜中存在的生物活性物质直接或间接参与了形觉剥夺性近视的形成。⑤环境因素并非高度近视发病的决定因素,它仅起一定程度的促进作用。将今后的工作重点放在高度近视基因定位的研究,基因表达的调控及巩膜胶原代谢、网膜生物活性物质之间的关系研究上,无疑会进一步揭示高度近视的病因,为防治高度近视开辟新途径。 相似文献
15.
16.
Chandipura virus (CHPV) has emerged as an important pediatric encephalitis-causing pathogen with very high mortality in India. No specific vaccine or treatment is available till date. We attempted to prepare a candidate vaccine employing recombinant CHPV Glycoprotein (rGp). The Glycoprotein gene (G-gene) of CHPV was expressed using Baculovirus expression system. The rGp was purified by HPLC and used for mice immunization, 3 doses, and 4 weeks apart. One microgram rGp was found to be optimum. Sero-conversion was observed as early as 2nd week by detecting anti-CHPV IgG antibodies. Antibody titres were immunogen-concentration dependent. Intracerebral challenge of the immunized mice with 100 LD50 of the homologous strain demonstrated 90% protection. In in vitro neutralization, antibodies from the immunized mice were able to neutralize heterologous viruses. There was 60% T cell proliferation observed against rGp in immunized mice. The study shows that rGp induces both arms of immune response and represents an ideal vaccine candidate for further evaluations. 相似文献
17.
瘢痕疙瘩是烧伤外科研究的重要课题,其形成机制尚未完全明确,本文就其在遗传机制、免疫作用、细胞增殖与胶原代谢、细胞因子等方面的研究进展进行综述。 相似文献
18.
Hideaki Iwaki Kazuyoshi Johnin Susumu Kageyama Chul Jang Kim Takahiro Isono Tatsuhiro Yoshiki 《International journal of urology》2007,14(10):918-923
OBJECTIVES: Vesicoureteral reflux (VUR) is the most common congenital urinary tract anomaly. This disease can pose a major threat to the kidneys as twenty percent of patients with endstage renal disease are reported to have VUR. Although genetic studies for uroplakin III (UPIII) have been reported recently, no study has focused on UPIII gene expression in VUR patients. We describe here the up-regulation of UPIII mRNA in exfoliated urinary cells from primary VUR patients. METHODS: A real-time RT-PCR for UPIII mRNA was performed on exfoliated urothelial cells from 18 primary VUR and 38 control samples. UPIII mRNA copies were calculated for each sample. The statistical differences were assessed by the Mann-Whitney U test. Receiver operator characteristic curves were constructed for analysis of the diagnostic values. RESULTS: UPIII mRNA was found to be up-regulated to a greater extent in VUR than in control exfoliated urinary cells (mean +/- SE: 497.0 +/- 178.5 copies vs. 69.0 +/- 10.0 copies, respectively, P < 0.001). In evaluating the measurement of urinary UPIII mRNA as a screening test for VUR, the sensitivity was 77.8% and the specificity was 76.3% by the best diagnostic cutoff point. CONCLUSIONS: This is the first report demonstrating up-regulation of UPIII in mRNA levels in VUR patients. We submit that the quantitative measurement of urinary UPIII mRNA has a potential of developing into the first non-invasive screening test for VUR. 相似文献
19.
Tae-Jin Song M.D. Ph.D. David P. Eisenberg M.D. Prasad S. Adusumilli M.D. Michael Hezel B.S. Yuman Fong M.D. 《Journal of gastrointestinal surgery》2006,10(4):532-542
The rising incidence of hepatocellular carcinoma (HCC) in western countries, along with the poor prognosis offered by present-day
treatment modalities, makes novel therapies for this disease necessary. Oncolytic herpes simplex viruses (HSV) are replication-competent
viruses that are highly effective in the treatment of a wide variety of experimental models of human malignancies. This study
seeks to investigate the effectiveness of oncolytic herpes viruses in the treatment of primary HCC cell lines. Sixteen commercially
available human HCC cell lines were studied. G207 is an attenuated, replication-competent, oncolytic HSV engineered to selectively
replicate within cancer cells. Cell lines were tested for viral sensitivity to G207 and their ability to support viral replication
using standard cytotoxicity and viral replication assays. Eleven of 16 cell lines were moderately to highly sensitive to G207
viral oncolysis. HCC cell lines additionally demonstrated the ability to support viral replication in vitro with as high as
800-fold amplification of the administered viral dose observed. G207 is cytotoxic to, and efficiently replicates within, HCC
cell lines in vitro. From these data, we suggest that oncolytic HSV therapy may have a role in the treatment of HCC, and in
vivo studies are warranted.
Presented in part at the 2005 American Hepato-Pancreato-Biliary Association Congress, Hollywood, Florida, April 14–17, 2005.
Supported by grants R01CA75461 and R01CA72632 from the National Institutes of Health, and by grant MBC-99366 from the American
Cancer Society (Yuman Fong). 相似文献
20.
目的探讨自发性高血压大鼠颈动脉中抑癌基因P53和原癌基因c-jun、c-fos、c-myc mRNA的表达.方法用逆转录聚合酶链式反应检测两种基因的表达水平.正常雄性大鼠作为对照组.结果 SHR颈动脉中,抑癌基因P53和原癌基因c-jun、c-fos、c-myc均有高表达,较WKY差异有显著性(P<0.05).结论自发性高血压大鼠颈动脉组织中抑癌基因P53和原癌基因c-jun、c-fos、c-myc均有高表达,癌基因的活化可能与自发性高血压大鼠颈动脉血管重构有关. 相似文献