全文获取类型
收费全文 | 1868篇 |
免费 | 84篇 |
国内免费 | 4篇 |
出版年
2021年 | 13篇 |
2020年 | 10篇 |
2019年 | 10篇 |
2018年 | 15篇 |
2017年 | 15篇 |
2016年 | 42篇 |
2015年 | 46篇 |
2014年 | 61篇 |
2013年 | 126篇 |
2012年 | 111篇 |
2011年 | 127篇 |
2010年 | 76篇 |
2009年 | 60篇 |
2008年 | 103篇 |
2007年 | 112篇 |
2006年 | 132篇 |
2005年 | 110篇 |
2004年 | 124篇 |
2003年 | 114篇 |
2002年 | 112篇 |
2001年 | 28篇 |
2000年 | 32篇 |
1999年 | 27篇 |
1998年 | 25篇 |
1997年 | 28篇 |
1996年 | 20篇 |
1995年 | 18篇 |
1994年 | 17篇 |
1993年 | 14篇 |
1992年 | 23篇 |
1991年 | 19篇 |
1990年 | 14篇 |
1989年 | 21篇 |
1988年 | 15篇 |
1987年 | 12篇 |
1986年 | 8篇 |
1985年 | 9篇 |
1984年 | 14篇 |
1983年 | 14篇 |
1982年 | 10篇 |
1981年 | 9篇 |
1980年 | 4篇 |
1979年 | 9篇 |
1978年 | 6篇 |
1974年 | 4篇 |
1972年 | 4篇 |
1971年 | 3篇 |
1967年 | 3篇 |
1966年 | 4篇 |
1965年 | 5篇 |
排序方式: 共有1956条查询结果,搜索用时 62 毫秒
61.
62.
Akiko Kusunoki Akira Wada Naoko Kurosaki Tohru Kimura Kazuyuki Takai Naoki Yamamoto 《Nucleosides, nucleotides & nucleic acids》2013,32(6-7):1705-1708
Abstract CXCR4 is both a chemokine receptor and an entry co-receptor for the T-cell line-adapted human immunodeficiency virus type 1 (HIV-1). To find a more efficacious therapeutic treatement of acquied immunodeficiency syndrome, we exmined the effects of antisense oligonucleotides on CXCR4 production. COS cells, stably expressing CXCR4 and CD4, were incubated with several kinds of oligonucleotides. Total human p24 antigen production was determined using an enzyme-linked immunosorbent assay system. An antisense phosphorothioate-modified oligonucleotide, complementary to the translation region of the CXCR4 mRNA, showed minimal inhibition of p24 antigen production at the high concentration of 2μM. On the other hand, the antisense phosphorothioate oligonucleotide, when used with transfection reagents, showed high efficiency at low concentrations, and confirmed the sequence-specific action. Interestingly, the oligonucleotide with the natual phosphodiester backbone, when used with the transfection reagents, also had high functional effects, comparable to the modified oligonucleotide. This defines the prerequisite criteria necessary for the design and the application of antisense oligonucleotides against HIV-1 in vivo. 相似文献
63.
Takayuki Abe Toshihmi Hatta Kazuyuki Takai Hideki Nakashima Tomoyuki Yokota Hiroshi Takaku 《Nucleosides, nucleotides & nucleic acids》2013,32(1-3):471-478
Abstract We have demonstrated that antisense phosphorothioate oligonucleotides (S-ODNs) inhibit influenza virus A replication in MDCK cells. Phosphorothioate and liposomally encapsulated oligonucleotides with two target sites (PB1 and PB2) were synthesized and tested for virus-induced cytopathogenicity effects by a MTT assay using MDCK cells. The liposomally encapsulated S-ODNs complementary to the sites of the PB2-AUG initiation codon showed highly inhibitory effects. On the other hand, the inhibitory effect of the liposomally encapsulated S-ODNs targeted to PB1 was considerably decreased in comparison with the PB2 target sites. The liposomally encapsulated oligonucleotides exhibited higher inhibitory activity than the free oligonucleotides. The activities of the modified oligonucleotides are effectively enhanced by using the liposomal carrier. 相似文献
64.
65.
Yumeko Hayashi Yoshiki Ishii Mitsumi Hata-Suzuki Ryo Arai Kazuyuki Chibana Akihiro Takemasa Takeshi Fukuda 《Respiratory research》2013,14(1):29
Background
Dendritic cells (DCs) are professional antigen-presenting cells that play a crucial role in the initiation and modulation of immune responses. Human circulating blood DCs are divided into two major subsets: myeloid DCs (mDCs); and plasmacytoid DCs (pDCs). Furthermore, mDCs are subdivided into two subsets: Th1-promoting mDCs (mDC1s); and Th2-promoting mDCs (mDC2s). Although CD1a, CD1c, and CD141 are generally used for classifying mDC subsets, their adequacy as a specific marker remains unclear. We performed this study to compare circulating mDC, pDC, mDC1, and mDC2 subsets between Th1- and Th2-mediated diseases using CD1a and CD141, and to analyze the adequacy of CD1a and CD141 as a marker for mDC1s and mDC2s, respectively.Methods
Thirty patients with sarcoidosis, 23 patients with atopic diseases, such as atopic bronchial asthma, and 23 healthy subjects as controls were enrolled in this study. Peripheral blood DC subsets were analyzed with flow cytometry according to expressions of CD11c, CD123, CD1a, and CD141. For functional analysis, we measured interleukin (IL) 12p40 levels produced by the sorted mDC subsets.Results
The sarcoidosis group showed decreased total DC (P < 0.05) and mDC counts (P < 0.05) compared to controls. The atopy group showed decreased CD1a+mDC count (P < 0.05), and increased CD1a-mDC count (P < 0.05) compared to controls. CD141+mDC count in the atopy group was higher than controls (P < 0.05). Sorted CD1a+mDCs produced higher levels of IL-12p40 than CD1a-mDCs (P = 0.025) and CD141+mDCs (P = 0.018).Conclusions
We conclude that decreased count of CD1a+mDC and increased count of CD141+mDC may reflect the Th2-skewed immunity in atopic diseases. The results of IL-12 levels produced by the sorted mDC subsets suggested the adequacy of CD1a and CD141 as a marker for mDC1 and mDC2, respectively, in vivo. 相似文献66.
Kentaro Inoue Jun Wada Jun Eguchi Atsuko Nakatsuka Sanae Teshigawara Kazutoshi Murakami Daisuke Ogawa Takahiro Terami Akihiro Katayama Atsuhito Tone Izumi Iseda Kazuyuki Hida Masao Yamada Tomohisa Ogawa Hirofumi Makino 《PloS one》2013,8(10)
We analyzed the urine samples of patients with type 2 diabetes at various stages of diabetic nephropathy by lectin microarray to identify a biomarker to predict the progression of diabetic nephropathy. Japanese patients with type 2 diabetes at various stages of nephropathy were enrolled and we performed lectin microarray analyses (n = 17) and measured urinary excretion of fetuin-A (n = 85). The increased signals of urine samples were observed in Siaα2-6Gal/GalNAc-binding lectins (SNA, SSA, TJA-I) during the progression of diabetic nephropathy. We next isolated sialylated glycoproteins by using SSA-lectin affinity chromatography and identified fetuin-A by liquid chromatography–tandem mass spectrometer. Urinary excretion of fetuin-A significantly increased during the progression of albuminuria (A1, 0.40±0.43; A2, 0.60±0.53; A3 1.57±1.13 ng/gCr; p = 7.29×10−8) and of GFR stages (G1, 0.39±0.39; G2, 0.49±0.45; G3, 1.25±1.18; G4, 1.34±0.80 ng/gCr; p = 3.89×10−4). Multivariate logistic regression analysis was employed to assess fetuin-A as a risk for diabetic nephropathy with microalbuminuria or GFR<60 mL/min. Fetuin-A is demonstrated as a risk factor for both microalbuminuria and reduction of GFR in diabetic nephropathy with the odds ratio of 4.721 (1.881–11.844) and 3.739 (1.785–7.841), respectively. Collectively, the glycan profiling analysis is useful method to identify the urine biomarkers and fetuin-A is a candidate to predict the progression of diabetic nephropathy. 相似文献
67.
Background
The way we formulate a mathematical model of an infectious disease to capture symptomatic and asymptomatic transmission can greatly influence the likely effectiveness of vaccination in the presence of vaccine effect for preventing clinical illness. The present study aims to assess the impact of model building strategy on the epidemic threshold under vaccination.Methodology/Principal Findings
We consider two different types of mathematical models, one based on observable variables including symptom onset and recovery from clinical illness (hereafter, the “observable model”) and the other based on unobservable information of infection event and infectiousness (the “unobservable model”). By imposing a number of modifying assumptions to the observable model, we let it mimic the unobservable model, identifying that the two models are fully consistent only when the incubation period is identical to the latent period and when there is no pre-symptomatic transmission. We also computed the reproduction numbers with and without vaccination, demonstrating that the data generating process of vaccine-induced reduction in symptomatic illness is consistent with the observable model only and examining how the effective reproduction number is differently calculated by two models.Conclusions
To explicitly incorporate the vaccine effect in reducing the risk of symptomatic illness into the model, it is fruitful to employ a model that directly accounts for disease progression. More modeling studies based on observable epidemiological information are called for. 相似文献68.
69.
Yasuhiro Umemura Junko Yoshida Masashi Wada Yoshiki Tsuchiya Yoichi Minami Hitomi Watanabe Gen Kondoh Junji Takeda Hitoshi Inokawa Kyoji Horie Kazuhiro Yagita 《PloS one》2013,8(6)
We previously reported emergence and disappearance of circadian molecular oscillations during differentiation of mouse embryonic stem (ES) cells and reprogramming of differentiated cells, respectively. Here we present a robust and stringent in vitro circadian clock formation assay that recapitulates in vivo circadian phenotypes. This assay system first confirmed that a mutant ES cell line lacking Casein Kinase I delta (CKIδ) induced ∼3 hours longer period-length of circadian rhythm than the wild type, which was compatible with recently reported results using CKIδ null mice. In addition, this assay system also revealed that a Casein Kinase 2 alpha subunit (CK2α) homozygous mutant ES cell line developed significantly longer (about 2.5 hours) periods of circadian clock oscillations after in vitro or in vivo differentiation. Moreover, revertant ES cell lines in which mutagenic vector sequences were deleted showed nearly wild type periods after differentiation, indicating that the abnormal circadian period of the mutant ES cell line originated from the mutation in the CK2α gene. Since CK2α deficient mice are embryonic lethal, this in vitro assay system represents the genetic evidence showing an essential role of CK2α in the mammalian circadian clock. This assay was successfully applied for the phenotype analysis of homozygous mutant ES cells, demonstrating that an ES cell-based in vitro assay is available for circadian genetic screening. 相似文献
70.
Akira Ainai Elly van Riet Ryo Ito Kazuyuki Ikeda Kyosuke Senchi Tadaki Suzuki Shin-ichi Tamura Hideki Asanuma Takato Odagiri Masato Tashiro Takeshi Kurata Pretty Multihartina Vivi Setiawaty Krisna Nur Andriana Pangesti Hideki Hasegawa 《Microbiology and immunology》2020,64(4):313-325
Intranasally administered influenza vaccines could be more effective than injected vaccines, because intranasal vaccination can induce virus-specific immunoglobulin A (IgA) antibodies in the upper respiratory tract, which is the initial site of infection. In this study, immune responses elicited by an intranasal inactivated vaccine of influenza A(H5N1) virus were evaluated in healthy individuals naive for influenza A(H5N1) virus. Three doses of intranasal inactivated whole-virion H5 influenza vaccine induced strong neutralizing nasal IgA and serum IgG antibodies. In addition, a mucoadhesive excipient, carboxy vinyl polymer, had a notable impact on the induction of nasal IgA antibody responses but not on serum IgG antibody responses. The nasal hemagglutinin (HA)-specific IgA antibody responses clearly correlated with mucosal neutralizing antibody responses, indicating that measurement of nasal HA-specific IgA titers could be used as a surrogate for the mucosal antibody response. Furthermore, increased numbers of plasma cells and vaccine antigen-specific Th cells in the peripheral blood were observed after vaccination, suggesting that peripheral blood biomarkers may also be used to evaluate the intranasal vaccine-induced immune response. However, peripheral blood immune cell responses correlated with neutralizing antibody titers in serum samples but not in nasal wash samples. Thus, analysis of the peripheral blood immune response could be a surrogate for the systemic immune response to intranasal vaccination but not for the mucosal immune response. The current study suggests the clinical potential of intranasal inactivated vaccines against influenza A(H5N1) viruses and highlights the need to develop novel means to evaluate intranasal vaccine-induced mucosal immune responses. 相似文献