全文获取类型
收费全文 | 52780篇 |
免费 | 5660篇 |
国内免费 | 4281篇 |
专业分类
耳鼻咽喉 | 446篇 |
儿科学 | 538篇 |
妇产科学 | 524篇 |
基础医学 | 5560篇 |
口腔科学 | 896篇 |
临床医学 | 6401篇 |
内科学 | 6952篇 |
皮肤病学 | 526篇 |
神经病学 | 2401篇 |
特种医学 | 1957篇 |
外国民族医学 | 20篇 |
外科学 | 5180篇 |
综合类 | 11421篇 |
现状与发展 | 10篇 |
一般理论 | 2篇 |
预防医学 | 4477篇 |
眼科学 | 1286篇 |
药学 | 5853篇 |
42篇 | |
中国医学 | 4076篇 |
肿瘤学 | 4153篇 |
出版年
2024年 | 217篇 |
2023年 | 804篇 |
2022年 | 2116篇 |
2021年 | 2616篇 |
2020年 | 2126篇 |
2019年 | 1827篇 |
2018年 | 1796篇 |
2017年 | 1753篇 |
2016年 | 1690篇 |
2015年 | 2523篇 |
2014年 | 2919篇 |
2013年 | 2823篇 |
2012年 | 3576篇 |
2011年 | 3895篇 |
2010年 | 2735篇 |
2009年 | 2119篇 |
2008年 | 2430篇 |
2007年 | 2818篇 |
2006年 | 2649篇 |
2005年 | 2297篇 |
2004年 | 2559篇 |
2003年 | 3133篇 |
2002年 | 2808篇 |
2001年 | 2255篇 |
2000年 | 1452篇 |
1999年 | 1017篇 |
1998年 | 665篇 |
1997年 | 614篇 |
1996年 | 405篇 |
1995年 | 371篇 |
1994年 | 325篇 |
1993年 | 198篇 |
1992年 | 208篇 |
1991年 | 182篇 |
1990年 | 156篇 |
1989年 | 149篇 |
1988年 | 115篇 |
1987年 | 100篇 |
1986年 | 77篇 |
1985年 | 73篇 |
1984年 | 29篇 |
1983年 | 23篇 |
1982年 | 15篇 |
1981年 | 19篇 |
1980年 | 15篇 |
1979年 | 6篇 |
1978年 | 8篇 |
1977年 | 5篇 |
1976年 | 6篇 |
1975年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Shinichiro Nanko Akira Ueki Mineko Hattori Xiao Y. Dai Tsukasa Sasaki Rimmei Fukuda Kazuhiko Ikeda Hajime Kazamatsuri 《American journal of medical genetics. Part A》1994,54(4):361-364
Parkinson's disease is thought to be caused by a combination of unknown environmental, genetic, and degenerative factors. Evidence from necropsy brain samples and pharmacokinetics suggests involvement of dopamine receptors in the pathogenesis or pathophysiology of Parkinson's disease. Genetic association studies between Parkinson's disease and dopamine D2, D3 and D4 receptor gene polymorphisms were conducted. The polymorphism was examined in 71 patients with Parkinson's disease and 90 controls. There were no significant differences between two groups in allele frequencies at the D2, D3, and D4 dopamine receptor loci. Our findings do not support the hypothesis that susceptibility to Parkinson's disease is associated with the dopamine receptor polymorphisms examined. © 1994 Wiley-Liss, Inc. 相似文献
52.
Direct evidence for the involvement of carbohydrate sequences in human sperm-zona pellucida binding 总被引:2,自引:0,他引:2
Several lines of evidence indicate that mammalian fertilization is
initiated via a binding process that is dependent upon the recognition of
oligosaccharide sequences associated with zona pellucida (ZP)
glycoproteins. Here, specific chemical and enzymatic methods were employed
to modify human ZP and to test their effects on sperm binding in the
hemizona assay system (HZA). Periodate oxidation of human ZP under very
mild conditions (10 min, 0 degrees C, 1 mM sodium m- periodate) that
attacks only terminal sialic acid resulted in a 30% loss of human sperm
binding in the HZA [hemizona index (HZI) = 70.2 +/- 10.9, n = 22; P <
0.05]. Periodate oxidation under mild conditions (1 h, 23 degrees C, 10 mM
sodium m-periodate) caused a 40% decrease in binding (HZI = 60.8 +/- 10.3;
n = 24; P< 0.01). Treatment of human ZP with neuraminidase caused a
substantial increase in sperm binding to human ZP (HZI = 297 +/- 45, n =
22; P < 0.01). These findings indicate that there are sialic acid
dependent binding sites coexisting with binding sites that are obscured by
sialic acid. To determine the periodate sensitivity of these obscured
sites, hemizona were first digested with neuraminidase and subsequently
subjected to mild periodate oxidation. The combined enzymatic and chemical
treatments caused a 79% decrease in sperm binding compared to control
hemizona (HZI = 20.7 +/- 4.4, n = 16; P < 0.001). Human sperm-ZP
interaction was also increased by digestion of human ZP with
endo-beta-galactosidase (HZI = 710 +/- 232, n = 14; P < 0.01),
indicating that potential binding sites for spermatozoa are also obscured
by lactosaminoglycan sequences. These studies support a definitive role for
the involvement of ZP-associated glycans in the binding of human
spermatozoa to oocytes.
相似文献
53.
54.
Testicular carcinoids are rare and the majority are of primary testicular origin. Testicular carcinoids can also be secondary from extra-testicular primary tumors, but the incidence is even less common. The case described here is a patient who initially had an infiltrating cecal carcinoid with hepatic metastasis. Following surgery, he was managed with octreotide and had close monitoring of the levels of serum serotonin and its urinary metabolite. He experienced a fairly indolent clinical course and 5 years after excision of the primary cecal carcinoid, his hepatic lesion has virtually been unchanged. However, he developed a secondary testicular metastasis. He has otherwise remained well, without evidence of metastases elsewhere on imaging studies. 相似文献
55.
Favorably tipping the balance between cytopathic and regulatory T cells to create transplantation tolerance 总被引:23,自引:0,他引:23
Therapeutic application of broadly reactive anti-T cell antibodies can lead not only to potent immunosuppression but also to profound and long-lived T cell depletion. We reasoned that a strategy that almost exclusively targets activated cytopathic donor reactive T cells and spares immunoregulatory networks might prove to be an exceptionally potent and highly selective means of producing long-term engraftment and tolerance. Herein we show that the combined administration of rapamycin and agonist IL-2- and antagonist IL-15-related cytolytic fusion proteins provides for long-term engraftment/tolerance in exceptionally stringent allotransplant models by (1) limiting the early expansion of activated T cells, (2) preserving and even exaggerating their subsequent apoptotic clearance, and (3) further amplifying the depletion of these activated T cells by antibody-dependent mechanisms, while (4) preserving CD4+CD25+ T cell-dependent immunoregulatory networks. 相似文献
56.
Thomas M Morgan Lan Xiao Patrick Lyons Bethany Kassebaum Harlan M Krumholz John A Spertus 《BMC medical genetics》2008,9(1):66
Background
Many candidate genes have been reported to be risk factors for acute coronary syndrome (ACS), but their impact on clinical prognosis following ACS is unknown. 相似文献57.
58.
小鼠单次经口灌服司帕沙星4、20和100mg/kg后,动物的活动正常,未出现兴奋的抑制作用;小鼠单次经口灌服司帕沙星4、20和100mg/kg,与戊巴比妥钠镇静催眠无明显协同作用;给猫静脉注射司帕沙星4、16和64mg/kg,对动物呼吸和心血管系统无明显影响。 相似文献
59.
Jin H Kang Y Xiao C Zhu K Ma Y Xie Q Ma J Xie Q He C Yang Z Sun Z Zhang X Chen M Zhang F Wang B 《Viral immunology》2005,18(3):539-548
Prime-boost strategy has been exhibited its potency to enhance immune responses, which would be important to the success to develop a vaccine against the foot-and-mouth disease virus (FMDV). An eukaryotic expression construct encoding the FMDV capsid VP1 protein with a recombinant VP1 protein or a commercial FMDV vaccine were tested in the prime-boost strategy in mice and cattle trials. The levels of induced specific antibodies, T cell proliferations, and DTH activities were significantly higher in the prime-boost groups than in those vaccinated with DNA, protein or FMDV vaccine alone. More importantly, the levels of neutralizing antibodies in the former groups were significantly higher than others and could last for at least four months in cattle trials. This study suggests that the prime-boost strategy significantly improves the effective immunity and may provide a longer protection against FMDV infection. 相似文献
60.
我们对采用PCR和聚丙烯酰胺凝胶电泳鉴别出的37例DNA完全来自父方的遗传学完全性葡萄胎(g-CHM)进行基因组中CTTtriplex系统各基因座位(CSF1PO、TPOX和TH01)等位基因分布的分析,并初步研究了这些等位基因分布与临床预后的关系。结果显示,在37例g-CHM中,CSF1PO座位中3个等位基因(11,12和14)和TPOX座位中的1个等位基因(11)的出现率与它们在北京地区人群中的基因频率差异显著;g-CHM中CSF1PO、TPOX和TH01基因座位杂合度显著低于北京地区人群的杂合度(P值均远小于0.01);在23例良性g-CHM和10例侵袭性g-CHM中:CSF1PO座位的等位基因10、11在良性中的出现率高于在侵袭性g-CHM中(P=0.026148),等位基因12在良性中的出现率低于在侵袭性g-CHM中(P=0.023879);TPOX座位的等位基因8在良性中的出现率高于在侵袭性g-CHM中(P=0.004322),而等位基因11在良性中的出现率低于其在侵袭性g-CHM中(P=0.008671)。上述结果提示,葡萄胎基因组中存在某些等位基因分布与在人群中的分布不同,而且葡萄胎是否具有侵袭性也和某些等位基因的出现率过高或过低有相关性,这些与侵袭性有关的等位基因可能成为预测葡萄胎是否具有侵袭性的标志物。 相似文献