全文获取类型
收费全文 | 1087篇 |
免费 | 87篇 |
国内免费 | 17篇 |
出版年
2024年 | 2篇 |
2023年 | 26篇 |
2022年 | 48篇 |
2021年 | 61篇 |
2020年 | 35篇 |
2019年 | 49篇 |
2018年 | 51篇 |
2017年 | 40篇 |
2016年 | 32篇 |
2015年 | 43篇 |
2014年 | 67篇 |
2013年 | 74篇 |
2012年 | 48篇 |
2011年 | 77篇 |
2010年 | 34篇 |
2009年 | 43篇 |
2008年 | 56篇 |
2007年 | 48篇 |
2006年 | 30篇 |
2005年 | 36篇 |
2004年 | 30篇 |
2003年 | 28篇 |
2002年 | 17篇 |
2001年 | 21篇 |
2000年 | 19篇 |
1999年 | 8篇 |
1998年 | 12篇 |
1997年 | 8篇 |
1996年 | 11篇 |
1995年 | 13篇 |
1994年 | 13篇 |
1993年 | 9篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1990年 | 11篇 |
1989年 | 6篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1986年 | 6篇 |
1985年 | 11篇 |
1984年 | 15篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1979年 | 5篇 |
1978年 | 7篇 |
1977年 | 4篇 |
1976年 | 2篇 |
1975年 | 5篇 |
1974年 | 4篇 |
排序方式: 共有1191条查询结果,搜索用时 15 毫秒
41.
IntroductionHuman Papillomavirus (HPV) 16 E6 serum antibodies are common in people with HPV-related oropharyngeal cancers (HPV-OPC), but not the general population. We explored HPV16 seroprevalence in people with and without oral HPV16 infection, the cause of HPV-OPC.MethodsOral rinse samples were collected semiannually and tested for 36 types of HPV DNA by PCR. HPV16 E6 serum antibodies were tested at the visit of first oral HPV detection in participants with prevalent (n = 54), or incident (n = 39) oral HPV16 DNA; or at baseline in matched participants with no oral HPV16 DNA (n = 155) using multiplex serology assay. Predictors of seropositivity were examined using logistic regression.ResultsHPV16 E6 seropositivity (7.5% vs 0.7%; p = 0.005) but not seropositivity to the other HPV16 antigens, was significantly more common in those with than without oral HPV16 infection. There were only 8 HPV16 E6 seropositive participants, but oral HPV16 DNA remained a strong predictor of E6 seropositivity after adjustment for other risk factors (aOR = 14.6 95%CI, 1.7–122.5). Seroprevalence was similar in those with prevalent (7.4%; 4/54), and incident (7.7%; 3/39) oral HPV16 infection (p = 1.00). E6 seroprevalence was associated with reduced oral HPV16 clearance, but was not statistically significant (HR = 0.65 95% CI, 0.16–2.70).Seropositive participants were primarily male (87.5%), HIV-positive (75.0%; median CD4 cell-count of 840) and had oral HPV16 DNA (87.5%). History of an HPV-related cancer (0/8) or HPV-related anogenital dysplasia (1/8) was rare, and 4 participants had recent screening showing no anogenital dysplasia.DiscussionHPV16 E6 seropositivity was higher among people with than without oral HPV16 infection, despite no known anogenital disease in these participants. 相似文献
42.
目的:分析和比较选择性环氧合酶-2 (Cox-2)抑制剂塞来昔布、5-脂氧合酶(5-Lox)抑制剂齐留通及Cox/5-Lox双酶抑制剂利克飞龙对酒精相关性口腔癌的抑制作用。方法:选择66只C57BL/6小鼠,分为阴性对照组、模型组(4NQO组)、阳性对照组、齐留通干预组、塞来昔布干预组和利克飞龙干预组。阴性对照组不做任何处理,其余各组饮用50μg/m L四硝基喹啉-1-氧化物(4NQO)溶液16周后,阳性对照组及各干预组以8%酒精溶液代替饮用水喂养8周,同时开始分别用三蒸水和同等药量的齐留通、塞来昔布、利克飞龙(100 mg·kg-1·d-1)灌胃8周;于24周处死动物,取舌行组织病理学观察、BrdU免疫组化染色、蛋白质印迹法(Western-blot)检测舌组织中5-Lox、Cox-2蛋白的表达。结果:饮用酒精后,口腔癌发生率从16.7%增加到58.3%,5-Lox、Cox-2蛋白表达显著增加癌组织中BrdU阳性率显著升高。齐留通干预后,口腔癌发生率(41.7%)显著降低,5-Lox表达显著减少,Cox-2表达显著增加,Brd U阳性率显著降低;塞来昔布干预后,口腔癌发生率(50.0%)显著降低,Cox-2表达显著减少,5-Lox表达显著增加,BrdU阳性率显著降低;利克飞龙干预后,口腔癌发生率(25%),Brd U阳性率与阳性对照组、齐留通干预组和塞来昔布干预组相比均显著降低,5-Lox、Cox-2蛋白表达比阳性对照组显著减少(P0.05)。结论:酒精促进口腔癌变的过程可能与5-Lox和Cox-2的表达上调关系密切;齐留通和塞来昔布可以分别抑制5-Lox和Cox-2活性,使口腔癌的发生率显著降低;利克飞龙对口腔癌的抑制作用优于齐留通和塞来昔布。 相似文献
43.
Caio Loureiro Salgado Emmanoel Loss Dias Lorenzzo Lyrio Stringari Luciana Polaco Covre Reynaldo Dietze Fausto Edmundo Lima Pereira Herbet Leonel de Matos Guedes Bartira Rossi-Bergmann Daniel Claudio Oliveira Gomes 《Microbes and infection / Institut Pasteur》2019,21(7):328-335
The use of adjuvants in vaccine formulations is a well-established practice to improve immunogenicity and protective immunity against diseases. Previously, we have demonstrated the feasibility of intranasal vaccination with the antigen of killed Leishmania amazonensis promastigotes (LaAg) against experimental leishmaniasis. In this work, we sought to optimize the immunogenic effect and protective immunity against murine visceral leishmaniasis conferred by intranasal delivery of LaAg in combination with a synthetic TLR1/TLR2 agonist (Pam3CSK4). Intranasal vaccination with LaAg/PAM did not show toxicity or adverse effects, induced the increase of delayed-type hypersensitivity response and the production of inflammatory cytokines after parasite antigen recall. However, mice vaccinated with LaAg/PAM and challenged with Leishmania infantum presented significant reduction of parasite burden in both liver and spleen, similar to those vaccinated with LaAg. Although LaAg/PAM intranasal vaccination had induced higher frequencies of specific CD4+ and CD8+ T cells and increased levels of IgG2a antibody isotype in serum, both LaAg and LaAg/PAM groups presented similar levels of IL-4 and IFN-y and decreased production of IL-10 when compared to controls. Our results provide the first evidence of the feasibility of intranasal immunization with antigens of killed Leishmania in association with a TLR agonist, which may be explored for developing an effective and alternative strategy for vaccination against visceral leishmaniasis. 相似文献
44.
45.
46.
V. Oberemok K. Laikova I. Golovkin L. Kryukov R. Kamenetsky-Goldstein 《Plant biology (Stuttgart, Germany)》2022,24(1):3-8
A plant’s associated biota plays an integral role in its metabolism, nutrient uptake, stress tolerance, pathogen resistance and other physiological processes. Although a virome is an integral part of the phytobiome, a major contradiction exists between the holobiont approach and the practical need to eradicate pathogens from agricultural crops. In this review, we discuss grapevine virus control, but the issue is also relevant for numerous other crops, including potato, cassava, citrus, cacao and other species. Grapevine diseases, especially viral infections, cause main crop losses. Methods have been developed to eliminate viruses and other microorganisms from plant material, but elimination of viruses from plant material does not guarantee protection from future reinfection. Elimination of viral particles in plant material could create genetic drift, leading in turn to an increase in the occurrence of pathogenic strains of viruses. A possible solution may be a combination of virus elimination and plant propagation in tissue culture with in vitro vaccination. In this context, possible strategies to control viral infections include application of plant resistance inducers, cross protection and vaccination using siRNA, dsRNA and viral replicons during plant ‘cleaning’ and in vitro propagation. The experience and knowledge accumulated in human immunization can help plant scientists to develop and employ new methods of protection, leading to more sustainable and healthier crop production. 相似文献
47.
48.
Viruses have become a prominent issue in public health, politics and economics due to the Covid-19 pandemic. Yet they have still met little attention in educational research, although misconceptions concerning viruses may contribute to antibiotics misuse, disbelief in existence of viruses and distrust in vaccination. We investigated knowledge and attitudes in Austria concerning Covid-19, viruses in general and vaccination. We conducted two cross-sectional online surveys. Study A was performed Austrian-wide (N = 1027), study B specifically targeted Austrian students from middle and high schools (N = 1728). Several participants did not believe in the existence of SARS-CoV-2. General vaccination damage was highly overrated. Many defined viruses as unicellular organisms or bacteria, and 6-10 % believed that they can be killed by antibiotics. Very many participants were unable to identify, whether a specific disease was caused by a virus or another pathogen. Knowledge was significantly correlated with level of education/grade and interest in virology. Additionally, willingness to become vaccinated was significantly correlated with knowledge. Many participants felt insufficiently informed about viruses at school. We strongly recommend that virus-related school education must highly improve to enable the population to correctly assess health-related information, counter fake news and come to scientifically informed decisions. 相似文献
49.
50.
Galea-Lauri J Wells JW Darling D Harrison P Farzaneh F 《Cancer immunology, immunotherapy : CII》2004,53(11):963-977
Dendritic cells (DCs) primed with tumor antigens (Ags) can stimulate tumor rejection. This study was aimed at evaluating the polarization of T-cell responses using various DC Ag-priming strategies for vaccination purposes. DCs cocultured with irradiated apoptotic tumor cells, DC-tumor fusions, and DCs pulsed with freeze-thaw tumor lysate Ags served as Ag-primed DCs, with EG7 tumor cells (class II negative) expressing OVA as the model Ag. DCs loaded with class I– and class II–restricted OVA synthetic peptides served as controls. Primed DCs were assessed by the in vitro activation of B3Z OVA-specific CD8 T cells and the proliferation of OVA-specific CD8 and CD4 T cells from OT-I and OT-II TCR transgenic mice, respectively. In vivo responses were measured by tumor regression following treatment with Ag-primed DCs and by CTL assays. Quantification of IL-2, IL-4, IL-5, IFN-, and TNF- by cytometric bead array (CBA) assay determined the polarization of TH1/TH2 responses, whereas H-2 Kb /SIINFEKL tetramers monitored the expansion of OVA-specific T cells. DC-EG7 hybrids stimulated both efficient class I and class II OVA responses, showing that DC-tumor hybrids are also capable of class II cross-presentation. The hybrids also induced the most potent CTLs, offered the highest protection against established EG7 tumors and also induced the highest stimulation of IFN- and TNF- production. DCs cocultured with irradiated EG7 were also effective at inducing OVA-specific responses, however with slightly reduced potency to those evoked by the hybrids. DCs loaded with lysates Ags were much less efficient at stimulating any of the OVA-specific T-cell responses, showed very little antitumor protection, and stimulated a weak TH1 response, overbalanced by an IL-5 TH2 response. The strategy of Ag-loading clearly influences the ability of DCs to polarize T cells for a TH1/TH2 response and thus determines the outcome of the elicited immune response, during various vaccination protocols.Abbreviations DC
Dendritic cell
- FSC
Forward scatter
- SSC
Side scatter
- TC
Tumor cells
This work was supported by Grant 9853 from the Leukaemia Research Fund, UK; a JRC studentship from GKT; and the Lewis Family Research Trust 相似文献