全文获取类型
收费全文 | 10521篇 |
免费 | 989篇 |
国内免费 | 440篇 |
专业分类
耳鼻咽喉 | 28篇 |
儿科学 | 257篇 |
妇产科学 | 103篇 |
基础医学 | 2973篇 |
口腔科学 | 118篇 |
临床医学 | 976篇 |
内科学 | 1454篇 |
皮肤病学 | 273篇 |
神经病学 | 287篇 |
特种医学 | 174篇 |
外国民族医学 | 4篇 |
外科学 | 597篇 |
综合类 | 2043篇 |
现状与发展 | 2篇 |
预防医学 | 511篇 |
眼科学 | 66篇 |
药学 | 736篇 |
3篇 | |
中国医学 | 455篇 |
肿瘤学 | 890篇 |
出版年
2024年 | 9篇 |
2023年 | 92篇 |
2022年 | 196篇 |
2021年 | 380篇 |
2020年 | 357篇 |
2019年 | 292篇 |
2018年 | 274篇 |
2017年 | 311篇 |
2016年 | 285篇 |
2015年 | 282篇 |
2014年 | 411篇 |
2013年 | 454篇 |
2012年 | 403篇 |
2011年 | 464篇 |
2010年 | 385篇 |
2009年 | 349篇 |
2008年 | 400篇 |
2007年 | 438篇 |
2006年 | 488篇 |
2005年 | 439篇 |
2004年 | 443篇 |
2003年 | 489篇 |
2002年 | 366篇 |
2001年 | 373篇 |
2000年 | 331篇 |
1999年 | 295篇 |
1998年 | 292篇 |
1997年 | 330篇 |
1996年 | 239篇 |
1995年 | 235篇 |
1994年 | 245篇 |
1993年 | 191篇 |
1992年 | 156篇 |
1991年 | 147篇 |
1990年 | 119篇 |
1989年 | 107篇 |
1988年 | 102篇 |
1987年 | 81篇 |
1986年 | 52篇 |
1985年 | 138篇 |
1984年 | 113篇 |
1983年 | 67篇 |
1982年 | 93篇 |
1981年 | 85篇 |
1980年 | 48篇 |
1979年 | 37篇 |
1978年 | 14篇 |
1977年 | 22篇 |
1976年 | 17篇 |
1975年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
制备大量的具有显著抗肿瘤活性的LAK细胞是确保IL-2/LAK疗法发挥抗肿瘤作用的前提。本文介绍增强LAK活性和LAK数量的有效的制备方法。IL-2的诱导剂量、不同材料(脾细胞、淋巴结细胞、外周血淋巴细胞、胸腺细胞等)的LAK产生的时间动力学及多种LAK细胞增强剂的协同应用,从而获得高效价和大数量的LAK细胞。 相似文献
82.
Analysis of T Cell Receptor Variability in Fresh Tumor-infiltrating Lymphocytes from Human Head and Neck Cancer 总被引:1,自引:1,他引:0
Kazuaki Chikamatsu Masao Eura Koji Nakano Yuichi Kanzaki Hiroaki Matsuoka Keisuke Masuyama Takeru Ishikawa 《Cancer science》1994,85(6):626-632
In this study, we analyzed T cell receptor (TCR) gene rearrangements in tumor-infiltrating lymphocytes (TIL) freshly obtained from 15 patients with head and neck cancer using the reversely transcribed polymerase chain reaction (RT-PCR) method. These TILs showed preferential expression of Vα10, Vα8 and Vα1, detected in 13 (87%), 11 (73%), and 9 cases (60%), respectively. The TCRVβ gene revealed diversity without preferential usage. The head and neck region is exposed to bacteria and viruses, so it is possible that the tumor site can become infected and accumulate T cells involved in infection and inflammation. Therefore, we also investigated TCR gene usage in T cells infiltrating in chronic sinusitis mucosa to address the question of whether the Vα1, Vα8, and Vα10 subfamilies are characteristic in TIL from squamous cell carcinoma of head and neck. TCR Vα10 gene usage was also the most common in Vα segment in T cells infiltrating the sinus mucosa, but Vα and Vα8 were not detected in the T cells in sinusitis. These results indicate that the Vα10 subfamily, the preferred T cell population in both TIL and T cells in inflammatory disease, might he involved mainly in inflammation or infection. On the other hand, Vα1 and Vα8 appear to be relatively specific populations for antitumor immunity in head and neck cancer. 相似文献
83.
本实验应用二十一种抗人白细胞分化抗原的单克隆抗体。通过ABC(avidin-biotin peroxidase complex)免疫酶标方法对十二例淋巴细胞白血病病人进行了免疫表型分析。提示单克隆抗体在淋巴细胞白血病病人的临床分型、治疗及预后估计上很有意义。粒、淋双表达白血病其本质不明,因而治疗上至今还没有一个理想的方案。 相似文献
84.
应用T淋巴细胞亚群单克隆抗体对类固醇治疗前后哮喘患者外周血T淋巴细胞亚群的变化进行检测,结果提示:类固醇治疗后OKT8较治疗前增高,OKT4/OKT8比值较治疗前降低并且接近正常,说明T淋巴细胞是类固醇作用的靶细胞,类固醇可直接影响T细胞亚群分布,发挥其非特异性抗炎作用。 相似文献
85.
目的比较从人外周血单核细胞及脐血CD34+细胞诱导树突细胞(DC)的方法及其特性.方法用淋巴细胞分离液分离外周血单个核细胞,贴壁法获得单核细胞;经GM-CSF及IL-4诱导获得DC.磁性活化细胞分选系统(MACS)分选脐血CD34+细胞,以GM-CSF、IL-4、TNF-α、SCF、FL、TPO等细胞因子诱导获得DC.用电镜、普通显微镜观察DC形态;流式细胞仪分析DC表型;同种混合淋巴细胞反应(allo-MLR)观察DC刺激T淋巴细胞增殖的能力.结果外周血单核细胞在因子GM-CSF、IL-4、TNF-α,脐血CD34+细胞在GM-CSF、IL-4、TNF-α、SCF、FL、TPO等因子作用下,可生成DC,并表达相应的DC分化抗原CD14、CD80、CD83、CD86、HLA-DR.脐血CD34+细胞具有较强的扩增能力,经2周诱导,体系细胞数可增加173.8士26.7倍,两种来源的DC均能刺激同种异体淋巴细胞的增殖反应.结论外周血单核细胞与脐血CD34+细胞,在体外均可诱导成DC,并具有相应的DC分化抗原和功能. 相似文献
86.
目的 根据小鼠神经元与T淋巴细胞具有共同抗原Thy-1的特点,利用鼠脑组织制备兔抗鼠T淋巴细胞血清。方法 提取鼠脑组织与弗氏完全佐剂混合,制成油包水乳剂, 免疫2只家兔后,采血,分离血清,用鼠脾淋巴细胞做凝集试验及补体依赖的细胞毒试验确定其活性。结果 制备的抗血清可与鼠脾淋巴细胞发生反应,2只兔抗血清凝集试验的效价分别为1:640及1:1280。抗血清1:320倍稀释后与鼠脾淋巴细胞做补体依赖的细胞毒试验,特异性细胞毒性均为32%。结论 用鼠脑组织制备抗鼠T淋巴细胞血清是一种可行的方法。 相似文献
87.
Gayle M. Davey Sonya L. Schober Bart T. Endrizzi Angela K. Dutcher Stephen C. Jameson Kristin A. Hogquist 《The Journal of experimental medicine》1998,188(10):1867-1874
During T cell development, thymocytes which are tolerant to self-peptides but reactive to foreign peptides are selected. The current model for thymocyte selection proposes that self-peptide–major histocompatibility complex (MHC) complexes that bind the T cell receptor with low affinity will promote positive selection while those with high affinity will result in negative selection. Upon thymocyte maturation, such low affinity self-peptide–MHC ligands no longer provoke a response, but foreign peptides can incidentally be high affinity ligands and can therefore stimulate T cells. For this model to work, thymocytes must be more sensitive to ligand than mature T cells. Contrary to this expectation, several groups have shown that thymocytes are less responsive than mature T cells to anti-T cell receptor for antigen (TCR)/CD3 mAb stimulation. Additionally, the lower TCR levels on thymocytes, compared with T cells, would potentially correlate with decreased thymocyte sensitivity. Here we compared preselection thymocytes and mature T cells for early activation events in response to peptide–MHC ligands. Remarkably, the preselection thymocytes were more responsive than mature T cells when stimulated with low affinity peptide variants, while both populations responded equally well to the antigenic peptide. This directly demonstrates the increased sensitivity of thymocytes compared with T cells for TCR engagement by peptide–MHC complexes. 相似文献
88.
V. P. Chernyshov E. V. Vykhovanets I. I. Slukvin Yu. A. Antipkin A. N. Vasyuk E. F. Klimenko 《Bulletin of experimental biology and medicine》1998,126(2):835-838
Examination of thyroid function and immune status of children living on the territories polluted by radionuclides in 1993–1994
revealed131I-dependent thyroid autoimmune reactions. These data indicate a possible effect of131I on the pituitary-thyroid and immune systems of children living on the radiation controlled territories.
Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 126, No. 8, pp. 216–220, August, 1998 相似文献
89.
对28例Graves病的可溶性白介素2受体(sIL2R)和各种甲状腺激素以及甲状腺自身抗体治疗前后比较,并进行逐步回归,结果表明:治疗后Graves病患者除TSH外,各种甲状腺激素及甲状腺自身抗体显著降低(P<001),并对sIL2R的上升与下降呈显著相关。 相似文献
90.
Cytotoxic T lymphocytes (CTL) recognize antigens derived from endogenously expressed proteins presented on the cell surface in the context of major histocompatibility complex (MHC) class I molecules. Because CTL are effective in antiviral and antitumor responses, the delivery of antigens to the class I pathway has been the focus of numerous efforts. Generating CTL by immunization with exogenous proteins is often ineffective because these antigens typically enter the MHC class II pathway. This review focuses on the usefulness of bacterial toxins for delivering antigens to the MHC class I pathway. Several toxins naturally translocate into the cytosol, where they mediate their cytopathic effects, and the mechanisms by which this occurs has been elucidated. Molecular characterization of these toxins identified the functional domains and enabled the generation of modified proteins that were no longer toxic but retained the ability to translocate into the cytosol. Thus, these modified toxins could be examined for their ability to carry peptides or whole proteins into the cytosolic processing pathway. Of the toxins studied—diphtheria, pertussis, Pseudomonas, and anthrax—the anthrax toxin appears the most promising in its ability to deliver large protein antigens and its efficiency of translocation. 相似文献