全文获取类型
收费全文 | 1047篇 |
免费 | 56篇 |
出版年
2022年 | 9篇 |
2021年 | 6篇 |
2020年 | 4篇 |
2019年 | 7篇 |
2018年 | 10篇 |
2017年 | 11篇 |
2016年 | 8篇 |
2015年 | 24篇 |
2014年 | 20篇 |
2013年 | 67篇 |
2012年 | 33篇 |
2011年 | 44篇 |
2010年 | 29篇 |
2009年 | 26篇 |
2008年 | 64篇 |
2007年 | 52篇 |
2006年 | 56篇 |
2005年 | 62篇 |
2004年 | 55篇 |
2003年 | 68篇 |
2002年 | 73篇 |
2001年 | 21篇 |
2000年 | 13篇 |
1999年 | 21篇 |
1998年 | 24篇 |
1997年 | 28篇 |
1996年 | 19篇 |
1995年 | 27篇 |
1994年 | 20篇 |
1993年 | 23篇 |
1992年 | 14篇 |
1991年 | 13篇 |
1990年 | 14篇 |
1989年 | 9篇 |
1988年 | 13篇 |
1987年 | 9篇 |
1986年 | 12篇 |
1985年 | 7篇 |
1984年 | 8篇 |
1983年 | 11篇 |
1982年 | 9篇 |
1981年 | 7篇 |
1980年 | 4篇 |
1979年 | 5篇 |
1978年 | 10篇 |
1977年 | 8篇 |
1975年 | 4篇 |
1974年 | 3篇 |
1972年 | 6篇 |
1970年 | 6篇 |
排序方式: 共有1103条查询结果,搜索用时 31 毫秒
51.
Jun-ichi Shimizu Mikio Uehara Masazumi Watanabe 《Bioscience, biotechnology, and biochemistry》2013,77(5):1339-1344
Experiments were done to investigate the volatile components in botrytized grape must and transformation of terpenoids in terpene-supplemented grape must by Botrytis cinerea. Twenty-eight compounds were identified in the volatile concentrate of botrytized must with a combined gas chromatograph-mass spectrometer. No terpenoids were detected in the concentrate. Linalool or terpinen-4-ol decreased a lot when Botrytis cinerea was cultured in the must with these terpenes for 15 days. In linalool-supplemented botrytized must 9 identified and 3 unidentified terpenes were found, while only geranial was detected in terpinen-4-ol-supplemented botrytized must. Botrytis cinerea did not produce terpenoid in grape must without terpenes, but transformed linalool added to grape must into some other monoterpenes. 相似文献
52.
Tetsuko Takabe Mikio Nishimtjra Takashi Akazawa 《Bioscience, biotechnology, and biochemistry》2013,77(10):2137-2142
The isolation of the photosynthetically competent chloroplast preparations was undertaken by means of the density gradient centrifugation on the modified silica sol “Percoll.” A clear separation of the intact chloroplast sustaining the high photosynthetic activities (light dependent CO2 fixation ca. 130μmol/mg Chl·hr) was established. The contamination of mitochondria and peroxisomes was estimated to be less than 3% by measuring the activities of their marker enzymes. The chloroplasts were proved to be free from endoplasmic reticulum and cytosol. The photosynthetic CO2 fixation of the isolated chloroplast preparations was saturated by illumination of the light intensity of 20,000 Lux (12 mW/cm2, 400~750 nm). 相似文献
53.
Takayoshi Higuchi Mikio Shimada Hideo Ōhashi 《Bioscience, biotechnology, and biochemistry》2013,77(12):1459-1465
Characterization of S-adenosylmethionine: catechol O-methyltransferase (EC. 2. 1. 1.6) isolated from bamboo shoot was carried out. Ferulic and sinapic acids which are believed to be lignin precursors are formed by the mediation of the enzyme, and the enzyme activity increased progressively during the lignification of bamboo shoots. Evidences suggest that this enzyme may contribute to the synthesis of lignin precursors. 相似文献
54.
Although the electrolytically obtained DPNH was not completely oxidized by usual dehydrogenases or diaphorases, one of the authors noticed that its absorption band at 340 mμ disappeared completely when it was incubated with the extract of mung been seedlings. The reaction was found to be stimulated by the addition of methylene blue, and the product was identified as DPN. Thus, the reaction resembled that of diaphorase, although it was less specific to the configuration of DPNH. But unlike usual diaphorase, it required a cofactor, which was neither flavins nor metallic ion, but an unidentified acidic substance. General properties of the enzyme and the cofactor are reported in this article. 相似文献
55.
Mikio Kawamori Yasushi Morikawa Yoriko Shinsha Kenichiro Takayama Seigo Takasawa 《Bioscience, biotechnology, and biochemistry》2013,77(10):2875-2879
The development of agar plate screening techniques has allowed the isolation of mutants of Trichoderma reesei capable of synthesizing cellulase under the conditions of a high concentration of glucose. Mutants resistant to catabolite repression by glycerol or glucose were isolated on Walseth’s cellulose (WC) agar plates containing 5% glycerol or 5% glucose, respectively. Mutants resistant to catabolite repression by glycerol were not derepressed enough for the production of cellulase on WC agar plates containing 5% glucose or in flask cultures with a mixture of 1% Avicel and 3% glucose. On the contrary, two mutant strains resistant to catabolite repression by glucose (KDD-10 and DGD-16) produced large clearing zones on WC agar plates containing 5% glucose. Both strains could begin to produce CMCase even in the presence of residual glucose and finally produced 1.5 times the CMCase activity, in flask cultures on 1% Avicel and 3% glucose, than that with 1% Avicel alone. These results suggest that KDD-10 and DGD-16 are comparatively derepressed by glucose for cellulase production. 相似文献
56.
Mikio Shimizu Ryo Okachi Kazuo Kimura Takashi Nara 《Bioscience, biotechnology, and biochemistry》2013,77(8):1655-1661
Penicillin acylase (EC 3.5.1.11) of Kluyvera citrophila KY7844 was purified approximately 120-fold by DEAE-cellulose chromatography, hydroxyapatite chromatography and isoelectro-focusing fractionation. The purified enzyme, with an approximate molecular weight of 63,000, appeared to be homogeneous in disc electrophoretic analysis, and showed isoelectric point (Ip) 8.12 and 13.0 units/mg of specific activity for cephalexin hydrolysis. The Michaelis constant (Km) for cephalexin and for 7-[1-(1H)-tetrazolylacetamido]-desacetoxycephalosporanic acid ((1H) T-7ADCA) was 1.4 mM and 3.6 mM, respectively. This enzyme was capable of producing (1H) T-7ADCA in 80% yield from 1-(1H)-tetrazolylacetate methylester and 7-aminodesacetoxycephalosporanic acid. 相似文献
57.
Crude cell-free extracts from Cellulomonas fimi contain cellobiose phosphorylase which cleaves cellobiose into glucose and glucose-1-phosphate in the presence of inorganic phosphate. With the aid of this enzyme, two samples of C14-cellobiose labeled in reducing or non-reducing glucosyl moiety were prepared from uniformly labeled C14-glucose or C14-glucose-1-phosphate as substrate, respectively. The labeled preparations have been shown to be radiochemically pure. Analyses of the anaerobic fermentation products from C14-cellobiose by resting cell suspensions showed that both glucose moieties were fermented almost equivalently. However, relatively small differences in specific activities of the products revealed that significantly larger amounts of formic acid and smaller amounts of acetic acid were produced from the reducing glucose moiety than from the other half of the molecule. Succinic and lactic acids appeared to be produced almost equally from both moieties. 相似文献
58.
Yoshimasa Taniguchi Yasuko Matsukura Harumi Taniguchi Hideki Koizumi Mikio Katayama 《Bioscience, biotechnology, and biochemistry》2013,77(10):1684-1694
The bitter acids in hops (Humulus lupulus L.) and beer, such as α-, β-, and iso-α-acids, are known to affect beer quality and display various physiological effects. However, these compounds readily oxidize, and the effect of the oxides on the properties of beer or their potential health benefits are not well understood. In this study, we developed a simple preparative method for the bitter acid oxide fraction derived from hops and designated the constituents as matured hop bitter acids (MHBA). HPLC-PDA-ESI/HRMS and MS2 revealed that MHBA are primarily composed of α-acid-derived oxides, which possess a common β-tricarbonyl moiety in their structures similar to α-, β-, and iso-α-acids. We also developed a quantitative analytical method of whole MHBA by HPLC, which showed high precision and reproducibility. Using our newly developed method, the concentration of whole MHBA in several commercial beers was evaluated. Our results will promote the study of bitter acid oxides. 相似文献
59.
The dynamic behavior of organelles is essential for plant survival under various environmental conditions. Plant organelles, with various functions,migrate along actin filaments and contact other types of organelles, leading to physical interactions at a specific site called the membrane contact site. Recent studies have revealed the importance of physical interactions in maintaining efficient metabolite flow between organelles.In this review, we first summarize peroxisome function under different environmental conditions and growth stages to understand organelle interactions. We then discuss current knowledge regarding the interactions between peroxisome and other organelles, i.e., the oil bodies, chloroplast, and mitochondria from the perspective of metabolic and physiological regulation, with reference to various organelle interactions and techniques for estimating organelle interactions occurring in plant cells. 相似文献
60.
Elissa Chairani Takao Fuchigami Hirofumi Koyama Yusuke Ono Mikio Iijima Michiko Kishida Toshiro Kibe Norifumi Nakamura Shosei Kishida 《Biochemistry and Biophysics Reports》2022
Ameloblastoma is an odontogenic tumor located in the bone jaw with clinical characteristics of extensive bone resorption. It is a locally invasive tumor with a high recurrence rate despite adequate surgical removal. In bone disease, tumors and other cells including osteoblasts, osteoclasts, and osteocytes in the bone microenvironment contribute to the pathogenesis of tumor growth. However, the effect of osteoblasts on ameloblastoma cells is not well-understood, and there has been limited research on interactions between them.This study investigated interactions between ameloblastoma cells and osteoblasts using a human ameloblastoma cell line (AM-3 ameloblastoma cells) and a murine pre-osteoblast cell line (MC3T3-E1 cells). We treated each cell type with the conditioned medium by the other cell type. We analyzed the effect on cytokine production by MC3T3-E1 cells and the production of MMPs by AM-3 cells. Treatment with AM-3-conditioned medium induced inflammatory cytokine production of IL-6, MCP-1, and RANTES from MC3T3-E1 cells. The use of an IL-1 receptor antagonist suppressed the production of these inflammatory cytokines by MC3T3-E1 cells stimulated with AM-3-conditioned medium. The MC3T3-E1-conditioned medium triggered the expression of MMP-2 from AM-3 cells. Furthermore, we have shown that the proliferation and migration activity of AM-3 cells were accelerated by MC3T3-E1 conditioned media.In conclusion, these intercellular signalings between ameloblastoma cells and osteoblasts may play multiple roles in the pathogenesis of ameloblastoma. 相似文献