全文获取类型
收费全文 | 118506篇 |
免费 | 9457篇 |
国内免费 | 5222篇 |
专业分类
耳鼻咽喉 | 449篇 |
儿科学 | 2766篇 |
妇产科学 | 1228篇 |
基础医学 | 23144篇 |
口腔科学 | 1118篇 |
临床医学 | 8972篇 |
内科学 | 30596篇 |
皮肤病学 | 1670篇 |
神经病学 | 3871篇 |
特种医学 | 1847篇 |
外国民族医学 | 12篇 |
外科学 | 6002篇 |
综合类 | 16271篇 |
现状与发展 | 31篇 |
预防医学 | 12637篇 |
眼科学 | 867篇 |
药学 | 11417篇 |
29篇 | |
中国医学 | 4548篇 |
肿瘤学 | 5710篇 |
出版年
2024年 | 175篇 |
2023年 | 1383篇 |
2022年 | 3591篇 |
2021年 | 4316篇 |
2020年 | 3767篇 |
2019年 | 3860篇 |
2018年 | 3768篇 |
2017年 | 3746篇 |
2016年 | 4286篇 |
2015年 | 4780篇 |
2014年 | 7258篇 |
2013年 | 7780篇 |
2012年 | 7278篇 |
2011年 | 8006篇 |
2010年 | 6584篇 |
2009年 | 6161篇 |
2008年 | 6073篇 |
2007年 | 6058篇 |
2006年 | 5533篇 |
2005年 | 4796篇 |
2004年 | 4093篇 |
2003年 | 3575篇 |
2002年 | 2893篇 |
2001年 | 2673篇 |
2000年 | 2159篇 |
1999年 | 1901篇 |
1998年 | 1738篇 |
1997年 | 1567篇 |
1996年 | 1332篇 |
1995年 | 1355篇 |
1994年 | 1215篇 |
1993年 | 977篇 |
1992年 | 828篇 |
1991年 | 675篇 |
1990年 | 592篇 |
1989年 | 535篇 |
1988年 | 496篇 |
1987年 | 385篇 |
1986年 | 324篇 |
1985年 | 742篇 |
1984年 | 655篇 |
1983年 | 509篇 |
1982年 | 508篇 |
1981年 | 428篇 |
1980年 | 367篇 |
1979年 | 330篇 |
1978年 | 275篇 |
1977年 | 203篇 |
1976年 | 211篇 |
1975年 | 164篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
以地高辛甙元随机引物法标记HBV-DNA探针,以此探针检测慢性乙型肝炎患者的血清、肝组织,同时以ELISA法检测血清HBeAg、HBcAb。结果:血清NBeAg阳性率27%(10/37),血清HBV-DNA检出率57.1%(20/35),两者有显著性差异。血清HBcAb阳性率78.4%(29/37),肝组织HBV-DNA检出率83.8%(31/37),两者无显著性差异。血清与肝组织HBV-DNA检出率有显著性差异。提示:血清HBV-DNA检测是较HBeAg更为准确客观反映血液带毒状况的指标。而准确反映肝脏带毒状况的指标是肝组织HBV-DNA检测。当HBeAg阴转,血清HBV-DNA阴性而肝组织HBV-DNA阳性时,需注意肝硬化及肝癌的发生。 相似文献
92.
Pamela E. B. Rodgers-Johnson Frederick W. Hickling Aggrey Irons Bruce K. Johnson Maureen Irons-Morgan Gary A. Stone Clarence J. Gibbs 《Journal of molecular neuroscience : MN》1996,28(1-3):237-243
Reports of an 18-fold higher incidence of schizophrenia among second-generation Afro-Caribbeans, and especially Jamaican migrants
in the United Kingdom were soon called “an epidemic of schizophrenia,” with the inference that a novel virus, likely to be
perinatally transmitted, was a possible etiological agent. This intriguing observation led us to explore a possible link with
human T-cell lymphotropic virus type one (HTLV-I), because it is a virus that is endemic in the Caribbean Islands, is perinatally
transmitted, known to be neuropathogenic, and the cause of a chronic myelopathy (tropical spastic paraparesis/ HTLV-I associated
myelopathy). We therefore examined inpatients at the Bellevue Mental Hospital, Kingston, Jamaica and did standard serological
tests for retroviruses HTLV-I and HTLV-II and HIV-I and HIV-II on 201 inpatients who fulfilled ICD-9 and DSM III-R criteria
for schizophrenia. Our results produced important negative data, since the seropositivity rates for HTLV-I, the most likely
pathogen, were no greater than the seropositivity range for HTLV-I carriers in this island population, indicating that HTLV-I
and the other retroviruses tested do not play a primary etiological role in Jamaican schizophrenics. 相似文献
93.
用多粘菌素B琼脂糖亲和层析法清除内毒素,结果表明:5ml多粘菌素B层析柱的总吸附内毒素能力为450 μg,用此法可完全清除体液或各种液体中的内毒素,对血清及腹水中的内毒素也有明显的吸附作用,而其他各种主要成分(除内毒素外)经过处理后无明显改变。去氧胆酸是一种强有力的去污剂,可使已饱和的柱子复活,复活率达85%左右。该方法有简便,可靠,吸附能力大,柱子的复活率高等优点。本方法的建立为内毒素血症的治疗展示了新的前景。 相似文献
94.
Masanobu Satake Manabu Inuzuka Katsuya Shigesada Tsuneyuki Oikawa Yoshiaki Ito 《Cancer science》1992,83(7):714-722
The core sequence of the enhancer of murine leukemia virus (MuLV) long terminal repeat is highly conserved in a large number of MuLV strains and appears to play an essential role when SL3-3 or Moloney strains induce T cell lymphoma in mice. We found by using the electrophoretic mobility shift assay that a polyomavirus enhancer core-binding protein, PEBP2, bound to this core motif of MuLV. We also noted that PEBP2 in several hematopoietic cell lines derived from B lymphocyte, macrophage and myelocyte lineages migrated significantly faster than the authentic PEBP2 detected in NIH3T3 (ibroblasts. Interestingly, PEBP2 detected in the cell lines of T lymphocyte lineage appeared to contain both types, which were indistinguishable in electrophoretic mobility from those of NIH3T3 and of B lymphocyte, macrophage and myelocyte lineages. The treatment of the nuclear extract containing PEBP2 with phosphatase generated PEBP3, which is a subcomponent of PEBP2 and retained the same DNA-binding specificity as PEBP2. The altered mobility of hematopoietic cell-derived or T lymphocyte-derived PEBP2 was found to be due to the alteration of the mobility of PEBP3. Based on the distinct mobility of PEBP2/3 of T lymphocytes from those of other hematopoietic cells, we discuss the implication of PEBP2 in MuLV-induced T cell leukemia and T cell-specific gene expression. 相似文献
95.
短暂性脑缺血发作患者血浆中TXB2和PGF1α含量检测 总被引:3,自引:0,他引:3
本文用放射免疫法测定47例短暂性脑缺血发作(TIA)患者血浆中血栓素B_2(TXB_2)和6酮-前列腺F_(1α)(PGF_(1α))的含量。结果发现TIA患者血浆中TXB_2含量增高,PGF_(1α)降低;头颅CT或MRI示有小灶性梗塞者及TIA发作持续时间长于30min者TXB_2升高和PGF_(1α)降低更显著。治疗3个月后,血浆PGF_(1α)显著增高。TXB_2和PGF_(1α)在体内的失平衡是急性脑血管疾病发病的重要机理之一。 相似文献
96.
五型病毒性肝炎的暴露因素与临床表现的比较 总被引:2,自引:1,他引:1
比较急性病毒性肝炎患者感染打危险因素,同时比较五型肝炎的症状和体征。连续收集急性病毒性肝炎患者血清293份,用ELISA法检测了五型肝炎病毒的病原学指标,并进行了流赞美同学调查。暴露因素:丙肝的肠道外暴露外明显多于甲肝;甲肝和戊肝有较高的“甲肝”患者接触史;乙肝,丙肝和丁肝有高的“乙肝”接触史,与甲肝,戊肝相比差异显著。 相似文献
97.
Iain L. Campbell 《Journal of neuroimmunology》1996,71(1-2)
To elucidate the possible involvement of the inducible nitric oxide synthase (iNOS) and NO in the development of lymphocytic choriomeningitis (LCM), the consequences of inhibition of iNOS by the inhibitor aminoguanidine was examined in mice following intracerebral infection with LCM virus (LCMV). Aminoguanidine administration to mice infected with LCMV completely blocked increased plasma nitrate/nitrite levels and led to increased proinflammatory cytokine gene expression at early stages of lesion development in the brain, enhanced clinical severity and decreased survival time. The levels of LCMV recovered from the brain of aminoguanidine treated mice did not differ from those in infected control mice. These findings argue against either an anti-viral or pathogenic role of NO in LCM but rather suggest a possible protective action of this mediator. 相似文献
98.
Abstract. A patient with immune-mediated thrombocytopenia (ITP) and chronic hepatitis C virus (HCV) infection for 11 years was given immunosuppressive treatment because of an activation of his ITP. After 6 weeks of treatment with cyclophosphamide, cyclosporin A and cortisone the patient decided not to continue taking his medication. One month later he was readmitted to hospital due to fever, cough and jaundice. Clinical investigation revealed his condition to be caused by an activation of his HCV infection. It is concluded that, in parallel to the situation in hepatitis B, immunosuppressive treatment of patients with HCV infection may lead to increased viral replication, resulting in severe liver damage when immunocompetence is regained. 相似文献
99.
The normally expressed κ immunoglobulin light chain gene repertoire and somatic mutations studied by single-sided specific polymerase chain reaction (PCR); frequent occurrence of features often assigned to autoimmunity 下载免费PDF全文
L JUUL L HOUGS V ANDERSEN A SVEJGAARD T BARINGTON 《Clinical and experimental immunology》1997,109(1):194-203
The expressed human κ light chain gene repertoire utilized by healthy individuals was studied by two different single-sided specific PCR techniques to avoid bias for certain V genes. A total of 103 rearranged κ sequences from peripheral blood mononuclear cells from healthy individuals were cloned from cDNA and assigned to the Vκ and Jκ germ-line genes with the closest overall homology. The use of cDNA rather than genomic DNA focused the analysis on activated B cells rich in mRNA. Accordingly, the sequences represented the applied repertoire and almost all were somatically mutated. V genes from the Jκ-proximal duplication unit of the κ locus were almost exclusively used. A total of 65% of the sequences could be assigned to four or five genes: A27 (humkv325), L6 (Vg), L2 (humkv328), and A3 and/or A19. N additions and P nucleotides were quite common and found in 32% and 21% of the sequences, respectively. Extended CDR3s more than nine residues in length were found in 18% of the sequences, and in 71% of cases this was due to insertion of an extra proline residue. This proline was usually explained from the germ-line sequences involved. These results are in good agreement with those of previous repertoire studies using potentially V-gene-biased techniques. Thus, it is clear that restricted V-gene usage, common N and P additions, and extended CDR3 regions are normal features and not, as has been claimed, characteristics of pathological autoantibodies. 相似文献
100.