全文获取类型
收费全文 | 1232篇 |
免费 | 57篇 |
国内免费 | 1篇 |
专业分类
1290篇 |
出版年
2022年 | 11篇 |
2021年 | 15篇 |
2020年 | 9篇 |
2019年 | 17篇 |
2018年 | 18篇 |
2017年 | 13篇 |
2016年 | 23篇 |
2015年 | 54篇 |
2014年 | 60篇 |
2013年 | 170篇 |
2012年 | 91篇 |
2011年 | 77篇 |
2010年 | 68篇 |
2009年 | 37篇 |
2008年 | 79篇 |
2007年 | 77篇 |
2006年 | 55篇 |
2005年 | 59篇 |
2004年 | 60篇 |
2003年 | 57篇 |
2002年 | 46篇 |
2001年 | 7篇 |
2000年 | 11篇 |
1999年 | 10篇 |
1998年 | 7篇 |
1997年 | 10篇 |
1996年 | 3篇 |
1995年 | 9篇 |
1994年 | 9篇 |
1993年 | 9篇 |
1992年 | 10篇 |
1991年 | 9篇 |
1990年 | 11篇 |
1989年 | 9篇 |
1988年 | 5篇 |
1987年 | 8篇 |
1986年 | 4篇 |
1985年 | 5篇 |
1984年 | 6篇 |
1983年 | 4篇 |
1982年 | 5篇 |
1981年 | 9篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 5篇 |
1974年 | 9篇 |
1973年 | 3篇 |
1972年 | 2篇 |
1970年 | 2篇 |
排序方式: 共有1290条查询结果,搜索用时 15 毫秒
991.
Effect of Lignocellulose-Derived Inhibitors on Growth of and Ethanol Production by Growth-Arrested Corynebacterium glutamicum R 总被引:1,自引:0,他引:1 下载免费PDF全文
Shinsuke Sakai Yoshiki Tsuchida Shohei Okino Osamu Ichihashi Hideo Kawaguchi Takashi Watanabe Masayuki Inui Hideaki Yukawa 《Applied microbiology》2007,73(7):2349-2353
In cellulosic ethanol production, pretreatment of a biomass to facilitate enzymatic hydrolysis inevitably yields fermentation inhibitors such as organic acids, furans, and phenols. With representative inhibitors included in the medium at various concentrations, individually or in various combinations, ethanol production by Corynebacterium glutamicum R under growth-arrested conditions was investigated. In the presence of various inhibitors, the 62 to 100% ethanol productivity retained by the C. glutamicum R-dependent method far exceeded that retained by previously reported methods. 相似文献
992.
Yoshiki Matsui Dominique Lombard Raphaël Massarelli Paul Mandel Henri Dreyfus 《Journal of neurochemistry》1986,46(1):144-150
Neurons in culture obtained from dissociated cerebral hemispheres of 8-day-old chick embryos showed measurable activities of galactosyl-, fucosyl-, and sialyl-transferases at the external surface of their plasma membrane. Important changes in these activities were observed during cell proliferation and maturation, in particular the surface fucosyltransferase activity, and/or the amount of intracellular fucosylated acceptors increased during synaptogenesis, between 3 and 5 days in culture (d.i.c.). A sodium dodecyl sulfate radioelectrophoretic analysis of the fucosylated neuronal acceptors labelled with [14C]fucose showed, during synaptogenesis, the high labelling of two protein bands of 116 and 50 X 10(3) daltons. The fucosylation of glycoconjugates occurred preferentially, in neurons, upon glycoproteins whereas in glial cell cultures glycolipids were more fucosylated. The reasons for such a difference are not yet understood but the results suggest that the surface fucosyltransferase activity and fucosylated proteins in particular may play a role during the synaptogenesis of neurons in culture. 相似文献
993.
Setsuo Takeuchi Yoshiki Kono Akira Kawarada Yasuo Ota Masayoshi Nakayama 《Bioscience, biotechnology, and biochemistry》2013,77(4):859-861
Aqueous 70% methanol extract of rice (Oryza sativa, var. Hadsaduri) hulls was found to contain an effective plant growth regulator, which was located at Rf 0.7 on a histogram on silica gel (Kieselgel GF254) TLC (iso-PrOH: 14% NH4OH, 10:2). After preliminary purification by ion exchange, the crude extract was repeatedly purified by column chromatography. The active substance thus obtained as colorless crystals was identical with authentic nicotinamide. The growth promotive effect of nicotinamide in co-operation with ammonium ion on the intact plant at low concentration was observed. 相似文献
994.
Regulation of synaptic acetylcholine concentrations by acetylcholine transport in rat striatal cholinergic transmission 下载免费PDF全文
995.
Masahiro Kajihara Martin Simuunza Ngonda Saasa George Dautu Akina Mori-Kajihara Yongjin Qiu Ryo Nakao Yoshiki Eto Hayato Furumoto Bernard M. Hangombe Yasuko Orba Hirofumi Sawa Edgar Simulundu Shuetsu Fukushi Shigeru Morikawa Masayuki Saijo Jiro Arikawa Swithine Kabilika Mwaka Monze Victor Mukonka Aaron Mweene Ayato Takada Kumiko Yoshimatsu 《PLoS neglected tropical diseases》2021,15(6)
Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne zoonosis with a high case fatality rate in humans. Although the disease is widely found in Africa, Europe, and Asia, the distribution and genetic diversity of CCHF virus (CCHFV) are poorly understood in African countries. To assess the risks of CCHF in Zambia, where CCHF has never been reported, epidemiologic studies in cattle and ticks were conducted. Through an indirect immunofluorescence assay, CCHFV nucleoprotein-specific serum IgG was detected in 8.4% (88/1,047) of cattle. Among 290 Hyalomma ticks, the principal vector of CCHFV, the viral genome was detected in 11 ticks. Phylogenetic analyses of the CCHFV S and M genome segments revealed that one of the detected viruses was a genetic reassortant between African and Asian strains. This study provides compelling evidence for the presence of CCHFV in Zambia and its transmission to vertebrate hosts. 相似文献
996.
997.
Yoshiki Nakamura Satoshi Simpo Minyeong Lee Takashi Oikawa Taeko Yoshii Koji Noda Yosuke Kuwahara Kenzo Kawasaki 《Biotechnic & histochemistry》2000,75(1):1-6
We observed the histology and tetracycline (TC) labeling in a single frontal section of alveolar bone of upper first molars of adolescent rats. A single injection of TC was administered intraperitonealy in adolescent rats. After three weeks, the upper jaws were immersed rapidly in liquid nitrogen and sectioned. Five micrometer unfixed, undecalcified frozen sections were cut and observed by light and fluorescence microscopy. Frontal sections of the upper first molar area revealed that the structural relationships among the roots, the periodontal ligament and the alveolar bone, and also between the cervical enamel and the attachment epithelium were well preserved. The TC labeling lines in the sections were very clear and distinguished new bone from old bone. The brightness of the lines differed among regions. An analysis of the brightness in the same section suggested a difference in the bone forming activity at the time of injection. 相似文献
998.
Norihiro Imai Michitaka Suzuki Kazuhiko Hayashi Masatoshi Ishigami Yoshiki Hirooka Takaya Abe Go Shioi Hidemi Goto Toyoshi Fujimoto 《PloS one》2015,10(5)
We showed previously that UBXD8 plays a key role in proteasomal degradation of lipidated ApoB in hepatocarcinoma cell lines. In the present study, we aimed to investigate the functions of UBXD8 in liver in vivo. For this purpose, hepatocyte-specific UBXD8 knockout (UBXD8-LKO) mice were generated. They were fed with a normal or high-fat diet, and the phenotypes were compared with those of littermate control mice. Hepatocytes obtained from UBXD8-LKO and control mice were analyzed in culture. After 26 wk of a high-fat diet, UBXD8-LKO mice exhibited macrovesicular steatosis in the periportal area and microvesicular steatosis in the perivenular area, whereas control mice exhibited steatosis only in the perivenular area. Furthermore, UBXD8-LKO mice on a high-fat diet had significantly lower concentrations of serum triglyceride and VLDL than control mice. A Triton WR-1339 injection study revealed that VLDL secretion from hepatocytes was reduced in UBXD8-LKO mice. The decrease of ApoB secretion upon UBXD8 depletion was recapitulated in cultured primary hepatocytes. Accumulation of lipidated ApoB in lipid droplets was observed only in UBXD8-null hepatocytes. The results showed that depletion of UBXD8 in hepatocytes suppresses VLDL secretion, and could lead to periportal steatosis when mice are fed a high-fat diet. This is the first demonstration that an abnormality in the intracellular ApoB degradation mechanism can cause steatosis, and provides a useful model for periportal steatosis, which occurs in several human diseases. 相似文献
999.
Sakayu Shimizu Masaaki Ishida Nobuo Kato Yoshiki Tani Koichi Ogata 《Bioscience, biotechnology, and biochemistry》2013,77(11):2215-2220
A methanol-utilizing yeast Kloeckera sp. No. 2201, when grown with methanol as a sole carbon and energy source, accumulated about three times much flavin as those grown with glucose, ethanol, or glycerol. A high proportion of the total flavin was FAD in methanol-grown cells. A remarkable derepression of FAD pyrophosphorylase accompanied by an inducible formation of an FAD-dependent alcohol oxidase which catalyzes oxidation of methanol, the first step in the oxidation sequence, was observed during growth of the yeast on methanol. Significant elevations of riboflavin synthetase and flavokinase were also found. Formate, as well as methanol, effectively induced both FAD pyrophosphorylase and methanol-oxidizing enzymes (alcohol oxidase, formaldehyde dehydrogenase, formate dehydrogenase, and catalase). Observations with other methanol-utilizing yeasts also gave essentially same results. These results led to the conclusion that cellular flavin level might be under control with level of flavoprotein physiologically required. 相似文献
1000.