全文获取类型
收费全文 | 26570篇 |
免费 | 3131篇 |
国内免费 | 1980篇 |
专业分类
耳鼻咽喉 | 171篇 |
儿科学 | 313篇 |
妇产科学 | 243篇 |
基础医学 | 2963篇 |
口腔科学 | 623篇 |
临床医学 | 3760篇 |
内科学 | 3561篇 |
皮肤病学 | 296篇 |
神经病学 | 1306篇 |
特种医学 | 938篇 |
外国民族医学 | 23篇 |
外科学 | 2585篇 |
综合类 | 4778篇 |
现状与发展 | 5篇 |
一般理论 | 3篇 |
预防医学 | 2182篇 |
眼科学 | 648篇 |
药学 | 2925篇 |
46篇 | |
中国医学 | 2178篇 |
肿瘤学 | 2134篇 |
出版年
2024年 | 159篇 |
2023年 | 653篇 |
2022年 | 1536篇 |
2021年 | 1800篇 |
2020年 | 1397篇 |
2019年 | 1134篇 |
2018年 | 1114篇 |
2017年 | 1083篇 |
2016年 | 1011篇 |
2015年 | 1462篇 |
2014年 | 1658篇 |
2013年 | 1579篇 |
2012年 | 1985篇 |
2011年 | 2208篇 |
2010年 | 1457篇 |
2009年 | 1260篇 |
2008年 | 1401篇 |
2007年 | 1287篇 |
2006年 | 1209篇 |
2005年 | 1142篇 |
2004年 | 712篇 |
2003年 | 685篇 |
2002年 | 570篇 |
2001年 | 410篇 |
2000年 | 421篇 |
1999年 | 438篇 |
1998年 | 261篇 |
1997年 | 273篇 |
1996年 | 169篇 |
1995年 | 177篇 |
1994年 | 150篇 |
1993年 | 91篇 |
1992年 | 105篇 |
1991年 | 87篇 |
1990年 | 99篇 |
1989年 | 73篇 |
1988年 | 90篇 |
1987年 | 54篇 |
1986年 | 48篇 |
1985年 | 32篇 |
1984年 | 13篇 |
1983年 | 15篇 |
1981年 | 13篇 |
1979年 | 19篇 |
1977年 | 10篇 |
1975年 | 11篇 |
1974年 | 10篇 |
1973年 | 15篇 |
1969年 | 14篇 |
1966年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
Autoimmunity to Spermatozoa and the Testis 总被引:2,自引:0,他引:2
102.
J chain deficiency in human IgM monoclonal antibodies produced by Epstein-Barr virus-transformed B lymphocytes 总被引:1,自引:0,他引:1
Six human IgM monoclonal antibodies against Pseudomonas aeruginosa were purified and characterized. On agarose-acrylamide sodium dodecyl sulfate (SDS) gels run under nonreducing conditions, IgM monoclonal antibodies showed variable amounts of a slower migrating form of IgM in addition to the one co-migrating with plasma IgM. Protein blotting with anti-J chain antibody showed that the slower migrating form did not contain J chain. Analysis of one of the monoclonal antibodies by sucrose gradient centrifugation showed that the J chain-deficient form sedimented faster than the complete IgM. It is known that IgM preparations lacking J chain sediment faster by sucrose gradient centrifugation analysis and tend to form hexamers. The slower migrating form of IgM we observed on SDS gels under nonreducing conditions could be hexameric IgM. Further evaluation of this monoclonal antibody demonstrated that both forms of IgM had the same antigen-binding activity. Glycosylation of the light chain was demonstrated in two of the monoclonal antibodies. 相似文献
103.
白细胞介素1,肿瘤坏死因子α和脂多糖对人脐静脉内皮细胞表达 … 总被引:5,自引:0,他引:5
目的 观察细胞因子白细胞介素1(IL-1)β、肿瘤坏死因子(TNF)α和脂多糖(LPS)是否诱导人脐静脉内皮细胞表达单核细胞趋化蛋白1(MCP-1)mRNA及蛋白。方法 选取生长汇合的人脐胸脉内皮细胞,在其培养基中分别加入终浓度为2ng/ml的IL-1β、20ng/ml的TNFβ和100ng/ml的LPS,37℃共育4h后,按照一步法提取其总RNA,用γ-^22P标记的寡核苷酸dot blot分析 相似文献
104.
Luna VM Wang M Ono F Gleason MR Dallman JE Mandel G Brehm P 《Journal of neurophysiology》2004,92(4):2003-2009
On initial formation of neuromuscular junctions, slow synaptic signals interact through an electrically coupled network of muscle cells. After the developmental onset of muscle excitability and the transition to fast synaptic responses, electrical coupling diminishes. No studies have revealed the functional importance of the electrical coupling or its precisely timed loss during development. In the mutant zebrafish shocked (sho) electrical coupling between fast muscle cells persists beyond the time that it would normally disappear in wild-type fish. Recordings from sho indicate that muscle depolarization in response to motor neuron stimulation remains slow due to the low-pass filter characteristics of the coupled network of muscle cells. Our findings suggest that the resultant prolonged muscle depolarizations contribute to the premature termination of swimming in sho and the delayed acquisition of the normally rapid touch-triggered movements. Thus the benefits of gap junctions during early synapse development likely become a liability if not inactivated by the time that muscle would normally achieve fast autonomous function. 相似文献
105.
淋巴结血管内T细胞淋巴瘤1例报道及文献复习 总被引:1,自引:0,他引:1
目的 探讨血管内淋巴瘤 (IVL)的临床病理特征。方法 对 1例腹股沟淋巴结IVL临床、病理组织学及免疫表型进行观察分析并复习文献。结果 男性 31岁 ,不明原因高热伴消瘦 5 0天 ,右腹股沟直径 1cm淋巴结 1枚 ,B超示肝脏轻度增大 ,血LDH明显升高伴ESR及转氨酶轻度升高 ,外周血WBC 3 3× 10 7/L ,骨髓像、多种病原及各肿瘤相关抗原检测均无异常。病理活检 :腹股沟淋巴结大部分破坏 ,代之以大量扩张的中小血管 ,腔内充满大量异型淋巴样细胞 ,局部伴管壁、管周浸润并累及结外脂肪组织。瘤细胞免疫表型CD4 5、CD4 5RO、CD3阳性 ,CK、CD6 8、CD79α、CD2 0均阴性 ,血管壁及内皮细胞CD31、CD34阳性。行CHOP化疗后症状缓解 ,现仍在随访中。结论 IVL是一罕见的非霍奇金淋巴瘤 ,好发于中枢神经系统及皮肤 ,其他部位少见 ,绝大数为B细胞型 ,T型罕见 ,以浅表淋巴结活检确诊者尚无报道。临床表现有一定提示性 ,确诊靠组织病理学检查 ,部分病例对化疗敏感 ,但多数病例预后差 相似文献
106.
Saheki T Kobayashi K Iijima M Horiuchi M Begum L Jalil MA Li MX Lu YB Ushikai M Tabata A Moriyama M Hsiao KJ Yang Y 《Molecular genetics and metabolism》2004,81(Z1):S20-S26
Citrin is a mitochondrial aspartate glutamate carrier primarily expressed in the liver, heart, and kidney. We found that adult-onset type II citrullinemia is caused by mutations in the SLC25A13 gene that encodes for citrin. In this report, we describe the frequency of SLC25A13 mutations, the roles of citrin as a member of the urea cycle and as a member of the malate-aspartate shuttle, the relationship between its functions and symptoms of citrin deficiency, and therapeutic issues. 相似文献
107.
转染survivin反义mRNA对Jurkat淋巴瘤细胞生长和化疗敏感性的影响 总被引:2,自引:0,他引:2
目的 研究转染survivin反义mRNA对Jurkat淋巴瘤细胞生长的影响以及转染后淋巴瘤细胞对化疗药物的敏感性。方法 构建survivin反义mRNA真核表达质粒pcDNA3.1-反义(As)survivin;利用脂质体转染法将其转入高表达survivin mRNA T淋巴母细胞淋巴瘤Jurkat细胞系,用逆转录聚合酶链反应(RT—PCR)、免疫组织化学SP法、Western印迹法检测细胞中survivin表达;用细胞计数、流式细胞术(FCM)检测其细胞生长曲线、细胞凋亡指数,并进行光镜、电镜形态学观察;并对转染pcDNA3.1-Assurvivin前后Jurkat细胞分别加入4-羟基-环磷酰胺(CTX)、甲氨蝶呤(MTX)72h后,常规MTT检测细胞存活率。结果 RT—PCR检测转染pcDNA3.1-Assurvivin后48h、5和6周Jurkat细胞survivin mRNA表达,发现survivin mRNA表达皆低于对照组;转染后survivin蛋白表达也明显降低。转染pcDNA3.1-Assurvivin后Jurkat细胞生长倍增时间(52h)明显延长;用FCM检测细胞凋亡发现,转染pcDNA3.1-Assurvivin后Jurkat细胞凋亡指数[20.2%(48h)]明显高于对照组(转染空质粒和未转染组,2.1%和1.3%);5和6周为6.2%和6.8%,明显高于未转染细胞(1.3%和1.0%)。光镜、电镜观察见转染细胞出现较多凋亡细胞及一些变性肿胀细胞;MTT检测结果显示Jurkat细胞转染前后,经化疗药物4-羟基-环磷酰胺和甲氨蝶呤作用,转染细胞的抑制率明显大于未转染组,差异有统计学意义(P〈0.05)。结论 survivin基因对Jurkat细胞系的生长起着重要的作用,抑制survivin基因表达在T淋巴母细胞淋巴瘤治疗中可能有重要的意义,该基因似可能作为治疗的靶点。 相似文献
108.
Prevalence of Antibodies to Hepatitis E Virus in Veterinarians Working with Swine and in Normal Blood Donors in the United States and Other Countries 总被引:27,自引:0,他引:27
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
X. J. Meng B. Wiseman F. Elvinger D. K. Guenette T. E. Toth R. E. Engle S. U. Emerson R. H. Purcell 《Journal of clinical microbiology》2002,40(1):117-122
Hepatitis E virus (HEV) is endemic in many developing and some industrialized countries. It has been hypothesized that animals may be the source of infection. The recent identification of swine HEV in U.S. pigs and the demonstration of its ability to infect across species have lent credence to this hypothesis. To assess the potential risk of zoonotic HEV infection, we tested a total of 468 veterinarians working with swine (including 389 U.S. swine veterinarians) and 400 normal U.S. blood donors for immunoglobulin G anti-HEV. Recombinant capsid antigens from a U.S. strain of swine HEV and from a human HEV strain (Sar-55) were each used in an enzyme-linked immunosorbent assay. The anti-HEV prevalence assayed with the swine HEV antigen showed 97% concordance with that obtained with the human HEV antigen (kappa = 92%). Among the 295 swine veterinarians tested from the eight U.S. states (Minnesota, Indiana, Nebraska, Iowa, Illinois, Missouri, North Carolina, and Alabama) from which normal blood donor samples were available, 26% were positive with Sar-55 antigen and 23% were positive with swine HEV antigen. In contrast, 18% of the blood donors from the same eight U.S. states were positive with Sar-55 antigen and 17% were positive with swine HEV antigen. Swine veterinarians in the eight states were 1.51 times more likely when tested with swine HEV antigen (95% confidence interval, 1.03 to 2.20) and 1.46 times more likely when tested with Sar-55 antigen (95% confidence interval, 0.99 to 2.17) to be anti-HEV positive than normal blood donors. We did not find a difference in anti-HEV prevalence between veterinarians who reported having had a needle stick or cut and those who had not or between those who spent more time (> or = 80% of the time) and those who spent less time (< or = 20% of the time) working with pigs. Similarly, we did not find a difference in anti-HEV prevalence according to four job categories (academic, practicing, student, and industry veterinarians). There was a difference in anti-HEV prevalence in both swine veterinarians and blood donors among the eight selected states, with subjects from Minnesota six times more likely to be anti-HEV positive than those from Alabama. Age was not a factor in the observed differences from state to state. Anti-HEV prevalence in swine veterinarians and normal blood donors was age specific and paralleled increasing age. The results suggest that swine veterinarians may be at somewhat higher risk of HEV infection than are normal blood donors. 相似文献
109.
急性髓系白血病中CD64表达的敏感性及特异性研究 总被引:1,自引:0,他引:1
研究急性髓系白血病(AML)免疫分型中CD64的敏感性和特异性.用系列抗原对132例AML患者的骨髓细胞进行直接标记,并用流式细胞术进行分析.结果表明:在AML中,CD64对急性粒-单细胞白血病(M4)和急性单核细胞白血病(M5)中敏感性最高(分别为96.4%和100%),在其他AML(M0、M1、M2、M3,M6、M7)中表达均较低.CD64对M4和M5中的特异性为56.5%.因此,CD64有助于AML中M4、M5的鉴别诊断. 相似文献
110.
浅谈中国传统文化与当代心理治疗 总被引:5,自引:0,他引:5
当代中国的心理治疗有待“本土化”。传统文化中的中华民族心理特征具有务实 ,重视人与自然、社会和谐关系的特点 ,不彰显个性而有所节制。心理治疗在当代应吸取传统文化里的人生哲学、超越而丰富的精神世界及中医养生术所蕴含的有益元素 相似文献