全文获取类型
收费全文 | 13606篇 |
免费 | 1541篇 |
国内免费 | 298篇 |
专业分类
耳鼻咽喉 | 45篇 |
儿科学 | 332篇 |
妇产科学 | 111篇 |
基础医学 | 1838篇 |
口腔科学 | 122篇 |
临床医学 | 992篇 |
内科学 | 1582篇 |
皮肤病学 | 171篇 |
神经病学 | 593篇 |
特种医学 | 98篇 |
外科学 | 528篇 |
综合类 | 1200篇 |
现状与发展 | 1篇 |
预防医学 | 5859篇 |
眼科学 | 271篇 |
药学 | 738篇 |
中国医学 | 182篇 |
肿瘤学 | 782篇 |
出版年
2024年 | 20篇 |
2023年 | 443篇 |
2022年 | 750篇 |
2021年 | 873篇 |
2020年 | 776篇 |
2019年 | 779篇 |
2018年 | 833篇 |
2017年 | 828篇 |
2016年 | 827篇 |
2015年 | 865篇 |
2014年 | 1007篇 |
2013年 | 893篇 |
2012年 | 846篇 |
2011年 | 949篇 |
2010年 | 699篇 |
2009年 | 630篇 |
2008年 | 414篇 |
2007年 | 415篇 |
2006年 | 397篇 |
2005年 | 324篇 |
2004年 | 274篇 |
2003年 | 287篇 |
2002年 | 220篇 |
2001年 | 187篇 |
2000年 | 151篇 |
1999年 | 112篇 |
1998年 | 100篇 |
1997年 | 90篇 |
1996年 | 59篇 |
1995年 | 46篇 |
1994年 | 47篇 |
1993年 | 30篇 |
1992年 | 38篇 |
1991年 | 33篇 |
1990年 | 28篇 |
1989年 | 23篇 |
1988年 | 28篇 |
1987年 | 15篇 |
1986年 | 16篇 |
1985年 | 17篇 |
1984年 | 17篇 |
1983年 | 10篇 |
1982年 | 8篇 |
1981年 | 9篇 |
1980年 | 7篇 |
1979年 | 10篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1976年 | 3篇 |
1975年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
Hanisah Sharif Swati Acharya Gopal Krishna R. Dhondalay Gilda Varricchi Shoshanna Krasner-Macleod Wannada Laisuan Amy Switzer Madison Lenormand Elena Kashe Rebecca V. Parkin Yi Yi Merve Koc Oleksandra Fedina Gemma Vilà-Nadal Gianni Marone Aarif Eifan Guy W. Scadding David J. Fear Mohamed H. Shamji 《The Journal of allergy and clinical immunology》2021,147(2):663-676
- Download : Download high-res image (285KB)
- Download : Download full-size image
102.
流行性乙型脑炎病毒活疫苗株SA14-14-2基因稳定性研究 总被引:1,自引:0,他引:1
目的 通过研究流行性乙型脑炎活疫苗减毒株基因稳定性,从分子水平证实流行性乙型脑炎活疫苗的遗传稳定性。方法分析流行性乙型脑炎活疫苗主种子、工作种子及其相应的疫苗病毒E蛋白基因核苷酸和氨基酸序列,并与其强毒株和基因库中乙脑病毒减毒株(AF15119)比较。结果乙脑活疫苗主种子、工作种子及其相应的疫苗病毒的E蛋白基因核苷酸序列完全相同。这些病毒E蛋白的氨基酸序列与基因库中乙脑病毒弱毒株(AF315119)比较显示第E447位点氨基酸有差异。结论乙脑病毒活疫苗减毒株遗传学特性稳定。 相似文献
103.
人β防御素-2与前列腺癌特异性膜抗原嵌合蛋白真核表达质粒构建及其诱导的小鼠特异性免疫应答 总被引:2,自引:0,他引:2
探索人β防御素2 (h BD- 2 )和前列腺特异性膜抗原(PSMA)共表达重组核酸疫苗针对前列腺癌的免疫治疗。研究以pc DNA3.1为载体,构建重组质粒pc DNA3.1/PSMA和pc DNA3.1/h BD- 2 - PSMA,通过RT- PCR和免疫组化检测其表达。免疫小鼠后,进行血清中抗体检测,CD4 、CD8 T淋巴细胞数目测定及CTL 特异性杀伤作用检测。结果显示构建的质粒转染COS- 7细胞后能表达目的基因,免疫小鼠后能在体内持久表达,可以诱导产生特异性抗体,能有效的刺激T细胞增生,诱导特异性CTL 反应。当以h BD- 2作为免疫佐剂时,CTL 活性更强。本研究成功的构建了含PSMA的表达质粒,免疫小鼠可以诱导出有效的体液和细胞免疫,为前列腺癌的免疫治疗奠定了一定的实验基础 相似文献
104.
The Thy-1 antigens or rat brain and thymus have been isolated and chemically characterized, but those of mice have not been identified. Moreover, it is uncertain whether the antigens are glycolipids or glycoproteins. This study with highly purified preparations of gangliosides GM1, 1GD1a, GD1b and GT1b from bovine brain and several ganglioside fractions from mouse brain showed that Thy-1 activity does not reside in gangliosides, but rather in the chloroform-methanol-insoluble residue of brain remaining after extraction of gangliosides. The antigen could be solubilized from this residue with a non-ionic detergent. The antigenic activity of the solubilized preparation was heat-labile but resistant to periodate. The chemical properties of the Thy-1 antigen of mouse brain are discussed. 相似文献
105.
目的 研究牛膝提取物神经再生素(NRF)对体外培养的大鼠海马神经元生长的促进作用及其对生长相关蛋白-43(GAP-43)表达的影响.方法 以体外原代培养的胎鼠海马神经元为研究模型,通过相差显微镜采用Scion软件测量不同浓度NRF(0.25mg/L、0.5mg/L、1mg/L)、不同作用时间(6h、12h、24h)对海马神经元神经突起生长的影响;通过实时荧光定量PER观察NRF不同浓度(0.25mg/L、0.5mg/L、1.0mg/L)及不同作用时间(6h、12h、24h)对海马神经元GAP-43基因表达的影响;采用免疫荧光细胞化学法和Western blotting,观察不同浓度NRF(0.25mg/L、0.5mg/L、1.0mg/L)加药24h后,对海马神经元GAP-43表达的影响.结果 NRF可有效地促进海马神经元的生长,加药后24h作用浓度为1mg/L时,作用最强;实时荧光定量RT-PCR、免疫荧光细胞化学法和Western blotting的结果提示,NRF能增加体外培养的海马神经元GAP-43的表达,浓度为1.0mg/L时,作用最佳.结论 NRF能促进体外培养的海马神经元神经突起的生长和GAP-43基因的表达,表明NRF对海马神经元具有神经营养作用. 相似文献
106.
目的:探讨补肾化瘀解毒方药物血清对肺癌细胞耐药逆转作用及机制。方法:采用MTT及流式细胞术,分别观察补肾化瘀解毒方药物血清对肺癌A549/DDP耐药细胞的细胞毒作用和多药耐药相关蛋白(MRP)表达的影响。结果:补肾化瘀解毒方药物血清对肺癌耐药细胞有一定的杀伤作用,能增强顺铂(DDP)对肺癌敏感细胞和耐药细胞的杀伤作用,显著降低MRP的表达(P<0.01),但对维拉帕米(VRP)的协同逆转作用不明显。结论:补肾化瘀解毒方药物血清具有增效和耐药逆转作用,其机制可能与其抑制肺癌耐药细胞MRP的表达有关。 相似文献
107.
Turnquist HR Vargas SE Schenk EL McIlhaney MM Reber AJ Solheim JC 《Immunologic research》2002,25(3):261-269
Prior to the binding of antigenic peptide, a complex of chaperone proteins associates with the Major Histocompatibility Complex
(MHC) class I heavy chain/β2m heterodimer. Although each dornain of the MHC class I heavy chain contains amino acid resid uses that influence chaperone
binding, there are several pieces of evidence that point to an interaction between the MHC clas 1α2/α3 domains and tapasin.
In egard to the site on tapasin involved in the tapasin/MHC interface, we have found that a particular region of tapasin (containing
amino acid residues 334–342) is necessary for the binding of tapasin to the MHC class I heavy chain. Our results also indicate
that amino acids in this region of tapasin also affect the proportion of MHC class I open forms expressed at the cell surface
and MHC class I egress from the endoplasmic reticulurn. Based on these results and those obtained by other laboratories, a
model for MHC class I/tapasin interaction is proposed. 相似文献
108.
Hao Wang Ingeborg Barisic Maria Loane Marie‐Claude Addor Linda M. Bailey Miriam Gatt Kari Klungsoyr Olatz Mokoroa Vera Nelen Amanda J. Neville Mary O'Mahony Anna Pierini Anke Rissmann Christine Verellen‐Dumoulin Hermien E.K. de Walle Awi Wiesel Katarzyna Wisniewska Lolkje T.W. de Jong‐van den Berg Helen Dolk Babak Khoshnood Ester Garne 《American journal of medical genetics. Part A》2019,179(4):595-601
We aimed to assess prevalence, birth outcome, associated anomalies and prenatal diagnosis of congenital clubfoot in Europe using data from the EUROCAT network, and to validate the recording of congenital clubfoot as a major congenital anomaly by EUROCAT registries. Cases of congenital clubfoot were included from 18 EUROCAT registries covering more than 4.8 million births in 1995–2011. Cases without chromosomal anomalies born during 2005–2009, were randomly selected for validation using a questionnaire on diagnostic details and treatment. There was 5,458 congenital clubfoot cases of which 5,056 (93%) were liveborn infants. Total prevalence of congenital clubfoot was 1.13 per 1,000 births (95% CI 1.10–1.16). Prevalence of congenital clubfoot without chromosomal anomaly was 1.08 per 1,000 births (95% CI 1.05–1.11) and prevalence of isolated congenital clubfoot was 0.92 per 1,000 births (95% CI 0.90–0.95), both with decreasing trends over time and large variations in prevalence by registry. The majority of cases were isolated congenital clubfoot (82%) and 11% had associated major congenital anomalies. Prenatal detection rate of isolated congenital clubfoot was 22% and increased over time. Among 301 validated congenital clubfoot cases, diagnosis was confirmed for 286 (95%). In conclusion, this large population‐based study found a decreasing trend of congenital clubfoot in Europe after 1999–2002, an increasing prenatal detection rate, and a high standard of coding of congenital clubfoot in EUROCAT. 相似文献
109.
Ascoli V Scalzo CC Andreoni M Manente L Pistilli A Lo Coco F 《Virchows Archiv : an international journal of pathology》1999,435(6):612-615
We report the unusual occurrence of Kaposi’s sarcoma following asbestos-related malignant mesothelioma, in a human deficiency
virus (HIV)-negative Italian man. Seropositivity to human herpes virus 8 (HHV8) was documented at the time of mesothelioma
diagnosis and preceded the onset of Kaposi’ sarcoma with a time lapse of 13 months. HHV8 DNA was detected by polymerase chain
reaction in lesional Kaposi’s sarcoma but not within mesothelioma. By immunostaining, mesothelioma cells expressed interleukin-6
and platelet-derived growth factor, which are important for survival of Kaposi’s sarcoma cells. Besides the possibility of
a casual association, we hypothesize that mesothelioma-linked factors may have contributed to the development of Kaposi’sarcoma
in the presence of HHV8 infection.
Received: 12 April 1999 / Accepted: 24 June 1999 相似文献
110.
Marianne Quiding-Jrbrink Mekuria Lakew Inger Nordstrm Jacques Banchereau Eugene Butcher Jan Holmgren Cecil Czerkinsky 《European journal of immunology》1995,25(2):322-327
Circulating spontaneous antibody-secreting cells (ASC) induced by mucosal and systemic immunizations in human volunteers have been characterized with respect to differentiation stage and homing commitments. Irrespective of the immunization route, the large majority of ASC co-expressed CD19 and HLA-DR, which are normally lost during the transition of plasmablasts to plasmocytes, as well as CD38, a marker of activated B cell blasts, expressed also by plasmocytes. However, these cells expressed neither CD28, a molecule acquired by plasmocytes, nor CD22 and CD37, which are lost during the transition of plasmablasts to plasmocytes. Therefore, the large majority of ASC found in peripheral blood after oral and parenteral immunizations are terminally differentiated B cells, but not fully differentiated plasmocytes. As a whole, the mucosally derived ASC population seemed to be more homogenously differentiated. CD25 was detected on few ASC, whereas ASC expressing CD71 were more numerous, especially among systemically derived ASC. Almost all ASC expressed the adhesion molecules CD44 and α4-integrins, irrespective of immunization route. However, virtually all systemically derived ASC expressed L-selectin, recognizing the peripheral lymph node addressin, whereas only a minority of mucosally induced blood ASC expressed L-selectin. These studies are the first to demonstrate in humans that circulating precursors of mucosal B cell immunoblasts utilize organ-specific recognition mechanisms distinct from those of corresponding systemic B cells and appear to be more advanced in the B lineage maturation pathway. Specialization of receptor expression could explain both the unification of immune responses in diverse mucosal sites and the physiologic segregation of mucosal from non-mucosal immune mechanisms in humans. 相似文献