全文获取类型
收费全文 | 540篇 |
免费 | 34篇 |
国内免费 | 2篇 |
出版年
2022年 | 2篇 |
2021年 | 6篇 |
2020年 | 3篇 |
2019年 | 6篇 |
2018年 | 6篇 |
2017年 | 6篇 |
2016年 | 15篇 |
2015年 | 23篇 |
2014年 | 22篇 |
2013年 | 35篇 |
2012年 | 27篇 |
2011年 | 38篇 |
2010年 | 18篇 |
2009年 | 18篇 |
2008年 | 29篇 |
2007年 | 30篇 |
2006年 | 37篇 |
2005年 | 30篇 |
2004年 | 35篇 |
2003年 | 27篇 |
2002年 | 21篇 |
2001年 | 14篇 |
2000年 | 8篇 |
1999年 | 8篇 |
1998年 | 6篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 7篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1990年 | 9篇 |
1989年 | 8篇 |
1988年 | 9篇 |
1987年 | 3篇 |
1986年 | 5篇 |
1985年 | 5篇 |
1984年 | 7篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1981年 | 5篇 |
1980年 | 3篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1971年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1958年 | 2篇 |
1956年 | 1篇 |
排序方式: 共有576条查询结果,搜索用时 31 毫秒
121.
Higuchi Kiyoko; Nishizawa Naoko-Kishi; Yamaguchi Hirotaka; Rmheld Volker; Marschner Horst; Mori Satoshi 《Journal of experimental botany》1995,46(8):1061-1063
In vitro nicotianamine synthase activity was measured in tobaccounder Fe-deficient or Fe-sufficient conditions. Its activitywas not induced by Fe-deficiency, in contrast to barley roots,implying that the molecular biological regulation of nicotianaminesynthase in response to Fe-deficiency may be different betweentobacco and barley. Key words: Barley, Fe-deficiency, ferric reduction, nicotianamine synthase, tobacco 相似文献
122.
Summary InCyclamen persicum Anneke, explants from the various vegetative organs of aseptic seedling formed embryoids. The optimal responses were recorded in Murashige and Skoog (MS) medium enriched with 5.0µM 2,4-dichlorophenoxyacetic acid (2,4-D), 0.5µM kinetin and 3–6% sucrose. Embryogenesis was enhanced at higher temperature of 25–30°C. On the other hand, light inhibited embryogenesis. Histological and morphological studies confirmed that the embryoids were indeed somatic embryos.Abbreviations MS
Murashige and Skoog
- 2,4-D
2,4-dichlorophenoxyacetic acid 相似文献
123.
Juliet Kiyoko Sugai Jean-Philippe Delgenes 《Journal of industrial microbiology & biotechnology》1995,14(1):46-51
Summary Cell extracts ofCandida guilliermondii grown ind-xylose,l-arabinose,d-galactose,d-glucose,d-mannose and glycerol as sole carbon sources possessed NADPH-dependent aldose reductase activity, but no NADH-dependent activity was detected.d-xylose andl-arabinose were the best inducers of aldose reductase activity. The highest enzyme activity ind-xylose orl-arabinose-grown cells was observed first withl-arabinose followed byd-xylose as substrates of the enzymatic reaction. However, only low activity was found ind-glucose,d-mannose andd-galactose-grown cells, indicating that these carbon sources cause catabolite repression. Enzyme activities induced ind-xylose-grown cells were twice as high as those obtained from the cells under resting conditions. Furthermore, the level of induction of aldose reductase activity depended on the initial concentration ofd-xylose. The present study shows that aldose reductase activity may be efficiently induced by pentose sugars of hemicellulosic hydrolysates and weakly by hemicellulosic hexoses. 相似文献
124.
Ken Tanigawa Morad Bensidhoum Noboru Takamura Hiroyuki Namba Shunichi Yamashita Hubert de Verneuil Cécile Ged 《Human genetics》1996,97(5):557-560
The molecular basis of the uroporphyrinogen III synthase (UROIIIS) deficiency was investigated in two members of a Japanese
family. This defect in heme biosynthesis is responsible for a rare autosomal recessive disease: congenital erythropoietic
porphyria (CEP) or Günther’s disease. The first patient was homoallelic for a novel missense mutation: a T to C transition
of nucleotide 634 that predicted a serine to proline substitution at residue 212 (S212P). The second patient appeared heteroallelic,
carrying the same missense mutation and a nonsense mutation: a C to T change at nucleotide 745, resulting in a premature stop
at codon 249, instead of a glutamine (Q249X). The corresponding mutated proteins were expressed in Escherichia coli and no residual activity was observed. A family study was also performed to determine the carrier status.
Received: 18 July 1995 相似文献
125.
126.
Yuki Taga Masashi Kusubata Kiyoko Ogawa-Goto Shunji Hattori 《The Journal of biological chemistry》2016,291(2):837-847
3-Hydroxyproline (3-Hyp), which is unique to collagen, is a fairly rare post-translational modification. Recent studies have suggested a function of prolyl 3-hydroxylation in fibril assembly and its relationships with certain disorders, including recessive osteogenesis imperfecta and high myopia. However, no direct evidence for the physiological and pathological roles of 3-Hyp has been presented. In this study, we first estimated the overall alterations in prolyl hydroxylation in collagens purified from skin, bone, and tail tendon of 0.5–18-month-old rats by LC-MS analysis with stable isotope-labeled collagen, which was recently developed as an internal standard for highly accurate collagen analyses. 3-Hyp was found to significantly increase in tendon collagen until 3 months after birth and then remain constant, whereas increased prolyl 3-hydroxylation was not observed in skin and bone collagen. Site-specific analysis further revealed that 3-Hyp was increased in tendon type I collagen in a specific sequence region, including a previously known modification site at Pro707 and newly identified sites at Pro716 and Pro719, at the early ages. The site-specific alterations in prolyl 3-hydroxylation with aging were also observed in bovine Achilles tendon. We postulate that significant increases in 3-Hyp at the consecutive modification sites are correlated with tissue development in tendon. The present findings suggest that prolyl 3-hydroxylation incrementally regulates collagen fibril diameter in tendon. 相似文献
127.
Sumiko Nakamura Junji Katsura Kiyoko Kato 《Bioscience, biotechnology, and biochemistry》2016,80(2):329-340
We searched for the easy and simple method to measure the novel indicators which reflect not only AAC, but also (RS) based on pasting properties using RVA. Novel indexes such as SB/Con and Max/Fin (Maximum viscosity/Minimum viscosity) ratios had a very high correlation with proportion of intermediate and long chains of amylopectin; Fb1+2+3 (DP ≧ 13). In Japonica polished rice, estimation formulae for AAC and RS content were developed using novel indexes based on pasting properties by RVA, and these equations showed determination coefficients of 0.89 and 0.80 for calibration and 0.71 and 0.75 for validation test. We developed the estimation formulae for AAC and RS content for Japonica starch samples. These equations showed determination coefficients of 0.86 and 1.00 for calibration and 0.76 and 0.83 for validation test, which showed that these equations can be applied to the unknown rice samples. 相似文献
128.
M Hayakawa S Sugiyama T Takamura K Yokoo M Iwata K Suzuki F Taki S Takahashi T Ozawa 《Biochemical and biophysical research communications》1986,137(1):424-430
An epoxy derivative of linoleate, 9,10-epoxy-12-octadecenoate, was demonstrated to be biosynthesized by neutrophils from various sources such as canine and human blood, and guinea-pig peritonea. It was nominated as leukotoxin from its 'toxic' activity onto mitochondrial respiration. From the reaction mixture of leukocytes with linoleate, an isomer of leukotoxin, 12,13-epoxy-9-octadecenoate, and a 'non-toxic' hydroxy derivative of linoleate, 9-hydroxy-12-octadecenoate, were detected. Such a cascade reaction of linoleate by leukocytes was discussed. Biosynthesis of leukotoxin by neutrophils was substantially enhanced by the presence of calcium ion and calcium-ionophore, A23187. Neutrophils contained leukotoxin, ca. 7 f moles/cell, which was extractable by 60% ethanol, but little of the isomer. 相似文献
129.
A highly sensitive method for quantitative analysis of phospholipid molecular species by high-performance liquid chromatography 总被引:2,自引:0,他引:2
A highly sensitive method was developed for quantitative analysis of phospholipid molecular species. Diradylglycerols prepared from phospholipids with phospholipase C were converted to the anthroyl-diradylglycerol derivatives, which could be separated into molecular species and sensitively quantified by reverse-phase HPLC using a fluorescence detector. All the molecular species of the derivatives had the same peak area per mole, and the peak areas were proportional to the amounts of the derivatives. Quantification could be carried out at the femtomole level. 相似文献
130.
Sedimentation of phytoplankton populations dominated by Microcystis in a shallow lake 总被引:1,自引:0,他引:1
The sedimentary flux of phytoplankton was measured using sedimenttraps in a shallow hypertrophic lake (Lake Kasumigaura), whereMicrocystis bloomed, from June to November 1983 The sedimenttraps were set at 0.5, 1.5 and 3.0 m depth in Takahamairi Bay(3.5 m depth). Microcystis spp. (including M.aerugmosa and M.viridis)in the traps were rare until early August, but increased thereafter.Sinking rates of Microcystis were 0.0045, 0.020 and 0.24 m day1in JuneAugust, September and October respectively, whichwere far lower than those of Melosira (0.21.7 m day1)and Syncdra (0.21.0 m day1). The total sedimentaryfluxes of POC and that of algal carbon during the study periodwere 283.2 and 96.7 gC m2 which were 59.5% and 20.3%of the gross primary production (475.8 gC m2) respectively.The sedimentary flux of living algae measured by algal countswas large in June but small in August and September. On theother hand, the flux of detritus obtained by subtracting totalalgal carbon from POC was small in June and July but large inAugust and September. Therefore diatoms, which appeared mostlyin June, tended to sink as live algae, while Microcystis sankas detritus after being decomposed or consumed in the waterIt was concluded from the results of carbon budget calculationsand the respiration rate of the 1- to 20-µm fraction thatthe activity of decomposers or consumers increased greatly inthe short period at the end of the bloom of Microcystis. 相似文献