全文获取类型
收费全文 | 8436篇 |
免费 | 455篇 |
国内免费 | 5篇 |
出版年
2022年 | 24篇 |
2021年 | 77篇 |
2020年 | 61篇 |
2019年 | 61篇 |
2018年 | 94篇 |
2017年 | 80篇 |
2016年 | 184篇 |
2015年 | 267篇 |
2014年 | 266篇 |
2013年 | 556篇 |
2012年 | 499篇 |
2011年 | 543篇 |
2010年 | 332篇 |
2009年 | 306篇 |
2008年 | 531篇 |
2007年 | 565篇 |
2006年 | 529篇 |
2005年 | 513篇 |
2004年 | 581篇 |
2003年 | 445篇 |
2002年 | 458篇 |
2001年 | 126篇 |
2000年 | 112篇 |
1999年 | 120篇 |
1998年 | 106篇 |
1997年 | 85篇 |
1996年 | 83篇 |
1995年 | 87篇 |
1994年 | 77篇 |
1993年 | 68篇 |
1992年 | 85篇 |
1991年 | 101篇 |
1990年 | 79篇 |
1989年 | 71篇 |
1988年 | 73篇 |
1987年 | 58篇 |
1986年 | 49篇 |
1985年 | 40篇 |
1984年 | 42篇 |
1983年 | 35篇 |
1982年 | 38篇 |
1981年 | 36篇 |
1980年 | 40篇 |
1979年 | 30篇 |
1978年 | 31篇 |
1977年 | 35篇 |
1976年 | 23篇 |
1974年 | 28篇 |
1973年 | 30篇 |
1972年 | 23篇 |
排序方式: 共有8896条查询结果,搜索用时 15 毫秒
41.
Makoto Yanai Takeshi Sugai Kenji Mori 《Bioscience, biotechnology, and biochemistry》2013,77(8):2373-2377
(S)-2-Hydroxy-β-ionone of 96% e.e. was synthesized from (S)-3-hydroxy-2,2-dimethyl cyclohexanone, which was easily obtained by the baker’s yeast reduction of 2,2-dimethylcyclohexane-l,3-dione. 相似文献
42.
43.
Takeshi Sassa Katsuhiro Suzuki Emi Haruki 《Bioscience, biotechnology, and biochemistry》2013,77(1):303-304
Quinolactacide isolated from Penicillium citrinum F 1539 was synthesized and evaluated for its insecticidal activities. The key steps of the total synthesis were an acyl migration reaction of the enol ester intermediate and dehydrogenation of tetrahydroquinolactacide with manganese dioxide. The synthesized quinolactacide showed 100% and 42% mortality against the green peach aphid (Myzus persicae) and diamondback moth (Plutella xylostella) at 500 ppm, respectively. 相似文献
44.
H. Ueda Takeshi Baba Nobuo Terada Yasuko Kato Shigeo Tsukahara Shinichi Ohno 《Histochemistry and cell biology》1997,108(3):243-248
It is known that the retina contains the protein dystrophin in the ribbon synapse, but the ultrastructural analysis is not
yet fully elucidated. Our previous study reported that dystrophin is localized under the rod cell membranes in rat retinas.
In the present study, we have investigated the relationship between dystrophin-rich regions of rod cell membranes and other
neuronal processes in mouse retinas with a monoclonal antibody raised against the human dystrophin C-terminus. Immunoblotting,
immunofluorescence stainings, and immunoelectron microscopy were employed. Immunoblotting analysis indicated that mouse retinas
possessed some of the dystrophin isoforms of approximately 260 kDa, 140 kDa, and 70 kDa molecular weight. Confocal images
showed a punctate appearance in the outer plexiform layer, as previously described. Immunoelectron microscopy showed that
dystrophin immunoreactive products were always observed at submembranous dense regions of the rod spherule abutting bipolar
processes. These results suggest that retinal dystrophin may be closely involved in signal transmission from rods to bipolar
cells.
Accepted: 7 May 1997 相似文献
45.
Muhammet Uyanik Takeshi Yasui Kazuaki Ishihara 《Bioorganic & medicinal chemistry letters》2009,19(14):3848-3851
The hypervalent iodine-catalyzed oxylactonization of ketocarboxylic acids to ketolactones was achieved in the presence of iodobenzene (10 mol %), p-toluenesulfonic acid monohydrate (20 mol %) and meta-chloroperbenzoic acid as a stoichiometric co-oxidant. 相似文献
46.
Isolation and characterization of an extremely thermophilic,cellulolytic, anaerobic bacterium 总被引:4,自引:0,他引:4
Masahito Taya Haruyuki Hinoki Toshiyuki Yagi Takeshi Kobayashi 《Applied microbiology and biotechnology》1988,29(5):474-479
Summary A cellulolyticm obligately anaerobic, extreme thermophile (strain NA10) was isolated from an alkaline hot spring in Nagano Prefecture, Japan. The microorganism was a non-spore-forming, flagellated rod which had a negative reaction to Gram stain, and occurred singly or in pairs. The growth temperature was between 50° C and 85° C with the optimum at 75° C, and the growth pH was between 6.0 and 9.5 with the optimum at 8.1. The anaerobe characteristically fermented cellulose, and produced acetic acid, H2, CO2 (main products) and lactic acid (minor product). The DNA had a base composition of 37.7 mol% guanine+cytosine content. 相似文献
47.
Shaista Shaikh Charles D Cox Takeshi Nomura Boris Martinac 《Channels (Austin, Tex.)》2014,8(4):321-326
Mechanosensitive (MS) ion channels are molecular sensors that detect and transduce signals across prokaryotic and eukaryotic cell membranes arising from external mechanical stimuli or osmotic gradients. They play an integral role in mechanosensory responses including touch, hearing, and proprioception by opening or closing in order to facilitate or prevent the flow of ions and organic osmolytes. In this study we use a linear force model of MS channel gating to determine the gating membrane tension (γ) and the gating area change (ΔA) associated with the energetics of MscS channel gating in giant spheroplasts and azolectin liposomes. Analysis of Boltzmann distribution functions describing the dependence of MscS channel gating on membrane tension indicated that the gating area change (ΔA) was the same for MscS channels recorded in both preparations. The comparison of the membrane tension (γ) gating the channel, however, showed a significant difference between the MscS channel activities in these two preparations. 相似文献
48.
49.
50.
Takuo Kosuge Hiroshi Zenda Kunio Tsuji Takeshi Yamamoto Hiroko Narita 《Bioscience, biotechnology, and biochemistry》2013,77(5):693-696
Distribution of tetramethylpyrazine (T.M.P.) in Japanese fermented foodstuffs was investigated by more accurate analytical method.Namely, the method was successful when trapping T.M.P. with picric acid after flash evaporation of the foodstuffs, followed by analysis with gas chromatography.T.M.P. was detected in many Japanese fermented foodstuffs, especially in Miso, Soy sause and Natto, which suggests that alkylpyrazines may play an important role as flavor of those foodstuffs. 相似文献