全文获取类型
收费全文 | 4324篇 |
免费 | 283篇 |
国内免费 | 1篇 |
出版年
2021年 | 31篇 |
2019年 | 24篇 |
2018年 | 44篇 |
2017年 | 45篇 |
2016年 | 58篇 |
2015年 | 76篇 |
2014年 | 107篇 |
2013年 | 377篇 |
2012年 | 189篇 |
2011年 | 165篇 |
2010年 | 116篇 |
2009年 | 122篇 |
2008年 | 189篇 |
2007年 | 205篇 |
2006年 | 202篇 |
2005年 | 209篇 |
2004年 | 200篇 |
2003年 | 209篇 |
2002年 | 231篇 |
2001年 | 105篇 |
2000年 | 95篇 |
1999年 | 119篇 |
1998年 | 67篇 |
1997年 | 61篇 |
1996年 | 44篇 |
1995年 | 47篇 |
1994年 | 40篇 |
1993年 | 53篇 |
1992年 | 92篇 |
1991年 | 71篇 |
1990年 | 69篇 |
1989年 | 65篇 |
1988年 | 48篇 |
1987年 | 62篇 |
1986年 | 46篇 |
1985年 | 57篇 |
1984年 | 60篇 |
1983年 | 49篇 |
1982年 | 52篇 |
1981年 | 51篇 |
1980年 | 28篇 |
1979年 | 44篇 |
1978年 | 48篇 |
1977年 | 37篇 |
1976年 | 30篇 |
1975年 | 30篇 |
1974年 | 28篇 |
1973年 | 23篇 |
1972年 | 21篇 |
1967年 | 20篇 |
排序方式: 共有4608条查询结果,搜索用时 15 毫秒
991.
Sachiko Hojo Mikiko Tokiya Masami Mizuki Mikio Miyata Kumiko T. Kanatani Airi Takagi Naomi Tsurikisawa Setsuko Kame Takahiko Katoh Takuya Tsujiuchi Hiroaki Kumano 《Bioelectromagnetics》2016,37(6):353-372
The purpose of the present study was to evaluate the validity and reliability of a Japanese version of an electromagnetic hypersensitivity (EHS) questionnaire, originally developed by Eltiti et al. in the United Kingdom. Using this Japanese EHS questionnaire, surveys were conducted on 1306 controls and 127 self‐selected EHS subjects in Japan. Principal component analysis of controls revealed eight principal symptom groups, namely, nervous, skin‐related, head‐related, auditory and vestibular, musculoskeletal, allergy‐related, sensory, and heart/chest‐related. The reliability of the Japanese EHS questionnaire was confirmed by high to moderate intraclass correlation coefficients in a test–retest analysis, and high Cronbach's α coefficients (0.853–0.953) from each subscale. A comparison of scores of each subscale between self‐selected EHS subjects and age‐ and sex‐matched controls using bivariate logistic regression analysis, Mann–Whitney U‐ and χ2 tests, verified the validity of the questionnaire. This study demonstrated that the Japanese EHS questionnaire is reliable and valid, and can be used for surveillance of EHS individuals in Japan. Furthermore, based on multiple logistic regression and receiver operating characteristic analyses, we propose specific preliminary criteria for screening EHS individuals in Japan. Bioelectromagnetics. 37:353–372, 2016. © 2016 The Authors. Bioelectromagnetics Published by Wiley Periodicals, Inc. 相似文献
992.
Toku Kanaseki Takeshi Miyatsuka Yoshio Fujitani Hirotaka Watada Yoshihide Tsujimoto Shigeomi Shimizu 《The EMBO journal》2016,35(18):1991-2007
Autophagy is a cellular process that degrades subcellular constituents, and is conserved from yeast to mammals. Although autophagy is believed to be essential for living cells, cells lacking Atg5 or Atg7 are healthy, suggesting that a non‐canonical degradation pathway exists to compensate for the lack of autophagy. In this study, we show that the budding yeast Saccharomyces cerevisiae, which lacks Atg5, undergoes bulk protein degradation using Golgi‐mediated structures to compensate for autophagy when treated with amphotericin B1, a polyene antifungal drug. We named this mechanism Golgi membrane‐associated degradation (GOMED) pathway. This process is driven by the disruption of PI(4)P‐dependent anterograde trafficking from the Golgi, and it also exists in Atg5‐deficient mammalian cells. Biologically, when an Atg5‐deficient β‐cell line and Atg7‐deficient β‐cells were cultured in glucose‐deprived medium, a disruption in the secretion of insulin granules from the Golgi occurred, and GOMED was induced to digest these (pro)insulin granules. In conclusion, GOMED is activated by the disruption of PI(4)P‐dependent anterograde trafficking in autophagy‐deficient yeast and mammalian cells. 相似文献
993.
994.
995.
Small ruminant lentiviral Vif proteins commonly utilize cyclophilin A,an evolutionarily and structurally conserved protein,to degrade ovine and caprine APOBEC3 proteins 下载免费PDF全文
Miyu Moriwaki Naoko Misawa Fengrong Ren Tomoko Kobayashi Yoshio Koyanagi Kei Sato 《Microbiology and immunology》2016,60(6):427-436
Mammals have co‐evolved with retroviruses, including lentiviruses, over a long period. Evidence supporting this contention is that viral infectivity factor (Vif) encoded by lentiviruses antagonizes the anti‐viral action of cellular apolipoprotein B mRNA editing enzyme catalytic polypeptide‐like 3 (APOBEC3) of the host. To orchestrate E3 ubiquitin ligase complex for APOBEC3 degradation, Vifs utilize mammalian proteins such as core‐binding factor beta (CBFB; for primate lentiviruses) or cyclophilin A (CYPA; for Maedi–Visna virus [MVV]). However, the co‐evolutionary relationship between lentiviral Vif and the mammalian proteins associated with Vif‐mediated APOBEC3 degradation is poorly understood. Moreover, it is unclear whether Vif proteins of small ruminant lentiviruses (SRLVs), including MVV and caprine arthritis encephalitis virus (CAEV), commonly utilize CYPA to degrade the APOBEC3 of their hosts. In this study, molecular phylogenetic and protein homology modeling revealed that Vif co‐factors are evolutionarily and structurally conserved. It was also found that not only MVV but also CAEV Vifs degrade APOBEC3 of both sheep and goats and that CAEV Vifs interact with CYPA. These findings suggest that lentiviral Vifs chose evolutionarily and structurally stable proteins as their partners (e.g., CBFB or CYPA) for APOBEC3 degradation and, particularly, that SRLV Vifs evolved to utilize CYPA as their co‐factor in degradation of ovine and caprine APOBEC3. 相似文献
996.
Shin Yamamoto Yusuke Oshima Takashi Saitou Takao Watanabe Teruki Miyake Osamu Yoshida Yoshio Tokumoto Masanori Abe Bunzo Matsuura Yoichi Hiasa Takeshi Imamura 《Biochemistry and Biophysics Reports》2016
Non-alcoholic steatohepatitis (NASH) is a common liver disorder caused by fatty liver. Because NASH is associated with fibrotic and morphological changes in liver tissue, a direct imaging technique is required for accurate staging of liver tissue. For this purpose, in this study we took advantage of two label-free optical imaging techniques, second harmonic generation (SHG) and auto-fluorescence (AF), using two-photon excitation microscopy (TPEM). Three-dimensional ex vivo imaging of tissues from NASH model mice, followed by image processing, revealed that SHG and AF are sufficient to quantitatively characterize the hepatic capsule at an early stage and parenchymal morphologies associated with liver disease progression, respectively. 相似文献
997.
Lipoprotein lipase (LPL) and hepatic triglyceride lipase (HTGL) were purified to homogeneity from human postheparin plasma. Molecular, catalytic and immunological properties of the purified enzymes were investigated. The native molecular weights of LPL and HTGL were 67,200 and 65,500, respectively, by gel chromatography. The subunit molecular weights of LPL and HTGL were 60,600 and 64,600, respectively, suggesting that these enzymes are catalytically active in a monomeric form. In addition, the purified LPL and HTGL each gave a single protein band when they were detected as glycoproteins with a probe of concanavalin A. The purified enzyme preparations were free of detectable antithrombin III by Western blot analysis. Catalytic properties of the purified enzymes were examined using triolein-gum arabic emulsion and triolein particles stabilized with phospholipid monolayer as substrates. LPL catalyzed the complete hydrolysis of triolein to free oleate and monooleate in the presence of apolipoprotein C-II. Apparent Km values for triolein and apolipoprotein C-II were 1.0 mM and 0.6 microM, and Vmax was 40.7 mmol/h per mg. HTGL hydrolyzed triolein substrate at a rate much slower than LPL, and produced mainly free oleate with little monooleate. Apparent Km and Vmax values were 2.5 mM and 16.1 mmol/h per mg, respectively. Polyclonal antibodies were developed against the purified LPL and HTGL. The purity and specificity of these antisera were ascertained by immunotitration, Ouchterlony double diffusion and Western blot analyses. The anti-human LPL and anti-human HTGL antiserum specifically reacted with the corresponding either native or denaturated enzyme, indicating that two enzymes were immunologically distinct. We developed an assay system for LPL and HTGL in human PHP by selective immunoprecipitation of each enzyme with the corresponding antiserum. 相似文献
998.
The development of porcine zona pellucida using monoclonal antibodies: II. Electron microscopy 总被引:2,自引:0,他引:2
J Takagi M Dobashi Y Araki Y Imai M Hiroi A Tonosaki F Sendo 《Biology of reproduction》1989,40(5):1103-1108
Following our previous study on the immunohistochemistry of porcine zonae pellucidae (ZP), we undertook the present study to localize the components of the ZP with immunoelectron microscopy, using three types of anti-porcine-ZP monoclonal antibodies (Mabs), named STA-1, STA-2, and STA-3. Some organelles of the oocyte were seen to react with STA-2 and STA-3 prior to ZP formation. As soon as a follicle began to mature, STA-2 and STA-3 reacted with the perinuclear space and the endoplasmic reticular membrane of the oocyte. The follicle first reacted with STA-1 at the secondary follicle stage. At this stage, the positive reaction involved the follicular cell layer as well as the oocyte and ZP. Positive reaction was scattered within and limited to the interfollicular cell space and was never found in the cytoplasm of follicular cells. At the antral follicle stage, the oocyte was surrounded by a thick, electron-dense ZP. A strong reaction was observed in the outer layer, but no significant reaction occurred in the inner layer. The convex and ragged outer margin of the ZP was characterized by the strongest reaction. 相似文献
999.
Masanobu Kitagawa Yoshio Kuwashima Tetsuo Nemoto Sachiko Seki Osamu Matsubara Tsutomu Kasuga 《Virchows Archiv. B, Cell pathology including molecular pathology》1989,58(1):365-370
The dynamics of lymphoid cell subpopulations in bronchoalveolar lavage fluid (BALF) and the systemic lymphoid organs of mice
after intravenous injection of B16 melanoma cells were examined with a fluorescence-activated cell sorter. The lymphoid cell
subpopulations of BALF and mediastinal lymph nodes showed significant changes in numbers and proportions, while those of other
lymphoid organs including inguinal lymph nodes, thymus and spleen, showed little change. In week 1, the cells with a Thy-1.2+, Lyt-1+, L3T4−, Lyt-2− phenotype and asialo-Gm1+ cells in BALF significantly increased and L3T4+ cells slightly increased in number. By week 3, the numbers of Lyt-2+ cells in BALF markedly increased in number (by about 90 times) compared with controls. The number of Thy1.2+ cells in mediastinal lymph nodes also increased significantly by week 3. Mice that had been pretreated with an immunosuppressive
dose of cyclophosphamide were also inoculated intravenously with B16 melanoma cells. In these mice, a significantly increased
number of pleural tumors developed and the number of Thy-1.2+ cells in BALF was markedly reduced from week 1 to 3. The results indicate that L3T4 and Lyt-2 double negative T-cells and
natural killer (NK) cells may be generated and/or mobilized to the lung in an early phase of experimental metastasis of B16
melanoma cells and that at a later stage, when multiple metastases develop, T-cells with a Lyt-2+ phenotype markedly increase, probably as an expression of a host reaction against proliferating metastatic tumor cells. 相似文献
1000.
Toshihiro Yasuda Yoko Ikehara Sayuri Takagi Keiko Mizuta Koichiro Kishi 《Human genetics》1989,82(1):89-91
Summary Sera from transgenic mice (TM) carrying human genes of 1-acid glycoprotein (orosomucoid or ORM) have been analyzed by isoelectrofocusing and subsequent immuno-blotting with antihuman ORM antibodies. With this technique it is possible to reveal selectively the human protein secreted in the TM sera. Orosomucoid bands present in TM sera have been compared with those of the most common human ORM phenotypes to correlate the products of specific genes to previously identified genetic variants. In this paper, we report the identification of the genes encoding for variants ORM1 F1 and ORM2 A, which are genes AGP-A and AGP-B/B respectively. The nucleotide sequences of these genes are known; therefore a direct correlation between variants and specific amino acid sequences can be established. 相似文献