全文获取类型
收费全文 | 10952篇 |
免费 | 588篇 |
国内免费 | 76篇 |
专业分类
耳鼻咽喉 | 128篇 |
儿科学 | 139篇 |
妇产科学 | 85篇 |
基础医学 | 1447篇 |
口腔科学 | 257篇 |
临床医学 | 634篇 |
内科学 | 2782篇 |
皮肤病学 | 277篇 |
神经病学 | 1013篇 |
特种医学 | 489篇 |
外科学 | 2006篇 |
综合类 | 56篇 |
一般理论 | 1篇 |
预防医学 | 270篇 |
眼科学 | 143篇 |
药学 | 586篇 |
中国医学 | 23篇 |
肿瘤学 | 1280篇 |
出版年
2023年 | 86篇 |
2022年 | 127篇 |
2021年 | 328篇 |
2020年 | 148篇 |
2019年 | 236篇 |
2018年 | 276篇 |
2017年 | 224篇 |
2016年 | 295篇 |
2015年 | 298篇 |
2014年 | 355篇 |
2013年 | 397篇 |
2012年 | 650篇 |
2011年 | 732篇 |
2010年 | 422篇 |
2009年 | 394篇 |
2008年 | 584篇 |
2007年 | 677篇 |
2006年 | 666篇 |
2005年 | 659篇 |
2004年 | 616篇 |
2003年 | 583篇 |
2002年 | 590篇 |
2001年 | 205篇 |
2000年 | 193篇 |
1999年 | 204篇 |
1998年 | 142篇 |
1997年 | 146篇 |
1996年 | 95篇 |
1995年 | 114篇 |
1994年 | 57篇 |
1993年 | 76篇 |
1992年 | 100篇 |
1991年 | 90篇 |
1990年 | 101篇 |
1989年 | 85篇 |
1988年 | 81篇 |
1987年 | 89篇 |
1986年 | 68篇 |
1985年 | 64篇 |
1984年 | 24篇 |
1983年 | 31篇 |
1982年 | 26篇 |
1981年 | 22篇 |
1980年 | 22篇 |
1979年 | 43篇 |
1978年 | 26篇 |
1975年 | 20篇 |
1974年 | 18篇 |
1973年 | 18篇 |
1972年 | 17篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
DNA typing of HLA in the patients with moyamoya disease 总被引:2,自引:0,他引:2
Takuya K. Inoue Kiyonobu Ikezaki Takehiko Sasazuki Takashi Ono Nobuhiro Kamikawaji Toshio Matsushima Masashi Fukui 《Journal of human genetics》1997,42(4):507-515
Summary Moyamoya disease is a clinical entity demonstrating a chronic occlusion of the cerebrovascular system. Although some possible
etiological factors have been postulated, the etiology of this disease is still unknown. So far, some investigations have
suggested the association between moyamoya disease and HLA in the serological typing. However, DNA typing of HLA have not
been performed yet. Thus, we performed DNA-typing of HLA in the unrelated Japanese patients with definite moyamoya disease,
using the polymerase chain reaction-sequence specific oligonucleotide probe (PCR-SSOP) technique. In the total patients,DQB1*0502 had a positive association with the disease. On the other hand,DRB1*0405 andDQB1*0401 showed a negative association. In comparing the early-onset and late-onset groups, two groups did not share the same disease
associated alleles at all. Thus, the etiology of moyamoya disease seem to have a genetic background. Furthermore, different
genetic factors might also be involved in the difference between the early-onset and late-onset groups. 相似文献
102.
Yasunari Nakamoto Shuichi Kaneko Masao Honda Masashi Unoura Jaehun Cheong Akihisa Harada Kouji Matsushima Kenichi Kobayashi Seishi Murakami 《Journal of medical virology》1994,42(4):374-379
The question was asked whether a predicted envelope protein, considered to be processed from the polyprotein precursor encoded by the putative E2/NS1 region of the hepatitis C virus (HCV) genome, may be observed in HCV-infected humans. Two polyclonal antibodies against recombinant E2/NS1 proteins were prepared and their reactivity tested against liver extracts from HCV-infected patients by immunoblotting analysis. A band corresponding to a size of 44 kDa was detected in liver extracts from patients who were positive for the HCV-specific antibody anti-C100-3 but not in liver extracts from patients who did not have anti-C100-3 antibody. Additionally, no band was detected using preimmune sera or antisera which had been preabsorbed with recombinant E2/NS1 proteins. Deglycosylation studies demonstrated that the 44 kDa protein was a glycosylated form of a 38 kDa protein which corresponds to the predicted molecular weight of the putative E2/NS1 protein. These results suggest that the 44 kDa protein is a product of the E2/NS1 region. Frequent observation of the 44 kDa band in cases of chronic active hepatitis C suggests a correlation between the expression of this protein and the progression of hepatitis. © 1994 Wiley-Liss, Inc. 相似文献
103.
Hironobu Tawaraya Showgo Ohkoshi Kenji Kuwana Masashi Watanabe Tomoteru Kamimura And Hitoshi Asakura 《Journal of medical virology》1995,45(4):367-372
Mass screening for hepatitis C virus antibody was carried out in 875 inhabitants (313 men and 562 women) of a town in Japan with a high rate of hepatitis B virus infection. The overall rate of positivity for anti-HCV was 8.8% (6.4% in men and 10,1% in women). The rate of positivity for hepatitis B virus surface antigen was 11.2%. Five subjects (0.6%) were positive for both markers. HCV-RNA was detected in 65 (88.4%) of 77 individuals who were positive for anti-HCV and in 1 (1.5%) of 60 individuals negative for anti-HCV. The genotype of the HCV genome was determined by PCR analysis using type-specific primers in 60 individuals. HCV type 1b was detected in 51 subjects (85%), type 2a in 3 subjects (5%), and type 2b in 6 subjects (10%). None of the individuals was infected with more than one genotype. The nucleotide sequences of the partial nonstructural 5 region of HCV type 1b genotype obtained from 6 individuals showed at least 92.0% homology in the nucleotide sequence, and 94.8% homology in the amino acid sequence. Homology among these clones was greater than their homology with previously described type 1 b sequences. The findings suggest that there was a specific local origin of HCV infection, although it was not possible to identify any single source of HCV infection. The results also indicate the presence of asymptomatic HCV carriers. © 1995 Wiley-Liss, Inc. 相似文献
104.
Motoneurons innervating the posterior belly of the digastric muscle were identified in the monkey, cat, dog, guinea pig and rat by the HRP method. After injections of horseradish peroxidase (HRP) into the posterior belly of the digastric muscle, two groups of HRP-labeled motoneurons were observed; the rostral group was seen as a small cluster of neurons in the lateral reticular area along the medial border of the descending root of the facial nerve, and the neurons of the caudal group were distributed among the ascending root fibers of the facial nerve. The distribution pattern of these neurons corresponded to that of the accessory facial nucleus neurons. The accessory facial nucleus was lacking in the rabbit in which the posterior digastric (PD) muscle is nonexistent. 相似文献
105.
Sugauchi F Orito E Kato H Suzuki S Kawakita S Sakamoto Y Fukushima K Akiba T Yoshihara N Ueda R Mizokami M 《Journal of medical virology》2003,69(1):33-40
Hepatitis B virus (HBV) genotypes have distinct geographical distribution. HBV sequences among hepatitis B carriers in Malawi have not been evaluated thus far. HBsAg serotype and genotype of HBV was determined in 20 serum samples from Malawian chronic HBV carriers, and two complete genomes and 13 entire pre-S2/S genes were sequenced directly. Genotype A HBV isolates were found in all of the samples, and serotype with adw2 and ayw2 were detected in three and 17 samples, respectively. In phylogenetic analyses, two complete genomes were classified into a subgroup A' that was described previously in South African isolates of the virus, and were separated from HBV isolates in Western countries with nucleotide differences ranging from 4.1-6.2%. The separation of subgroup A' was also evident in the tree topology of the entire pre-S1/S2, X and precore/core region, but not evident in the small-S region. The nucleotide divergences in subgroup A' were higher than those among genotype A without subgroup A' in the complete genomes as well as each of four open reading frames. All of the 13 pre-S2/S sequences were classified into the subgroup A', and clustered with known HBV isolates with ayw2 in carriers from South Africa and Zimbabwe. Three amino acids in the pre-S2/S gene were characteristic of subgroup A' with ayw2. In conclusion, unique HBV isolates of subgroup A' with ayw2 are prevalent in Malawi, and subgroup A' with a relatively higher nucleotide diversity may be a HBV isolate characteristic of the indigenous population of some African countries. 相似文献
106.
107.
Regulation of tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) and TRAIL receptor expression in human neutrophils 总被引:14,自引:0,他引:14 下载免费PDF全文
Kamohara H Matsuyama W Shimozato O Abe K Galligan C Hashimoto S Matsushima K Yoshimura T 《Immunology》2004,111(2):186-194
Tumour necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a member of the TNF superfamily, which is capable of inducing apoptosis in many cell types, including tumour and virus-infected cells, but rarely in normal cells. Expression of TRAIL mRNA and TRAIL receptors has previously been detected in neutrophils; however, the expression of TRAIL protein and the regulation of TRAIL and TRAIL receptor expression in these cells remain unknown. Here we report, for the first time, that neutrophils constitutively express TRAIL protein on their cell surface and that the TRAIL protein is shed during culture. TNF-alpha is a down-regulator of TRAIL expression, whereas IFN-gamma up-regulates the expression of TRAIL. Neutrophils did not express a detectable level of TRAIL-R1 or -R4, but constitutively expressed a low, but substantial, level of TRAIL-R2 and a high level of TRAIL-R3. Although the level of TRAIL-R2 was not significantly altered during culture under different experimental conditions, approximately 30% of TNF-alpha-treated cells rapidly lost their high-level TRAIL-R3 expression, whereas the majority of IFN-gamma-treated cells retained a high level of TRAIL-R3 expression. Anti-TRAIL neutralizing antibody significantly inhibited neutrophil apoptosis during cultures in medium alone, or in the presence of TNF-alpha or IFN-gamma. Thus, our study identified human neutrophils as a cellular source of TRAIL and suggests that neutrophil-derived TRAIL may play a role in immune surveillance. Our results also suggest a role for the TRAIL/TRAIL receptor system in neutrophil apoptosis. 相似文献
108.
Hitoshi Nishimura Masashi Emoto Kenji Hiromatsu Shunsuke Yamamoto Keiko Matsuura Hiroshi Gomi Toshio Ikeda Shigeyoshi Itohara Yasunobu Yoshikai 《European journal of immunology》1995,25(5):1465-1468
The secretion of tumor necrosis factor (TNF)-α from macrophages is regulated by both priming and triggering signals. We found that macrophages from mice lacking γδ T cells [T cell receptor (TCR) δ?/- mice], which lack the gene encoding the δ chain, produced only small amounts of TNF-α in response to lipopolysaccharide (LPS) and showed a reduced level of expression of CD14. Pre-incubation of macrophages from TCR δ-/- mice with γδ T cells from their TCR δ+/- littermates restored their capacity to produce TNF-α in response to LPS. The priming activity of γδ T cells was in part inhibited by neutralizing anti-interferon (IFN)-γ monoclonal antibodies. Collectively, these results suggest that γδ T cells play a role in priming macrophages to a steady state of activation via IFN-γ secretion, which allows them to produce TNF-α when exposed to LPS. 相似文献
109.
Maki Yoshikawa Masashi Hosokawa Kazuo Miyashita Hoyoku Nishino Takeshi Hashimoto 《Nutrients》2021,13(4)
Fucoxanthin (Fx) has preventive effect against muscle atrophy and myotube loss in vitro, but it has not yet been examined in vivo. Therefore, we aimed to investigate the effect of Fx on dexamethasone (Dex)-induced muscle atrophy and fat mass in mice. ICR mice were fed with Fx diets from 2 weeks before Dex treatment to the end of the study. Muscle atrophy was induced in the mice by oral administration of Dex. Body weight was significantly lower by Dex treatment. Visceral fat mass in the Fx-treated group were significantly lower than those in the control group. The Dex-induced decrease in tibialis anterior muscle mass was ameliorated by Fx treatment. Fx treatment significantly attenuated muscle lipid peroxidation compared with the control and Dex-treated groups. The phosphorylation of AMPK was significantly higher in the Dex-treated group than in the control group. The expression of cytochrome c oxidase (COX) IV was significantly higher in the Fx-treated group than in the control group. These results suggest that Fx may be a beneficial material to prevent muscle atrophy in vivo, in addition to the effect of fat loss. 相似文献
110.
Nakagawa Ichiro Park HunSoo Kotsugi Masashi Motoyama Yasushi Myochin Kaoru Takeshima Yasuhiro Matsuda Ryosuke Nishimura Fumihiko Yamada Syuichi Takatani Tsunenori Kichikawa Kimihiko Nakase Hiroyuki 《Neurosurgical review》2021,44(3):1493-1501
Neurosurgical Review - The present study aimed to determine the incidence of intraprocedural motor-evoked potential (MEP) changes and to correlate them with intraprocedural ischemic complications... 相似文献