全文获取类型
收费全文 | 1015篇 |
免费 | 45篇 |
出版年
2022年 | 7篇 |
2021年 | 10篇 |
2020年 | 12篇 |
2019年 | 10篇 |
2018年 | 11篇 |
2017年 | 13篇 |
2016年 | 23篇 |
2015年 | 37篇 |
2014年 | 35篇 |
2013年 | 57篇 |
2012年 | 58篇 |
2011年 | 39篇 |
2010年 | 30篇 |
2009年 | 34篇 |
2008年 | 32篇 |
2007年 | 33篇 |
2006年 | 41篇 |
2005年 | 21篇 |
2004年 | 28篇 |
2003年 | 44篇 |
2002年 | 38篇 |
2001年 | 36篇 |
2000年 | 37篇 |
1999年 | 27篇 |
1998年 | 14篇 |
1996年 | 16篇 |
1995年 | 7篇 |
1994年 | 8篇 |
1993年 | 6篇 |
1992年 | 21篇 |
1991年 | 16篇 |
1990年 | 13篇 |
1989年 | 9篇 |
1988年 | 33篇 |
1987年 | 14篇 |
1986年 | 24篇 |
1985年 | 16篇 |
1984年 | 14篇 |
1983年 | 5篇 |
1982年 | 7篇 |
1979年 | 9篇 |
1977年 | 7篇 |
1975年 | 10篇 |
1974年 | 15篇 |
1973年 | 14篇 |
1972年 | 20篇 |
1971年 | 12篇 |
1969年 | 4篇 |
1968年 | 4篇 |
1967年 | 6篇 |
排序方式: 共有1060条查询结果,搜索用时 250 毫秒
961.
A Ota 《The International journal of biochemistry》1982,14(2):111-118
1. Several enzyme activities were examined during the initial sporulating phase in Saccharomyces cerevisiae. 2. Catalase activity increased obviously after transfer to sporulation medium. 3. Catalase is probably considered to play an essential role in sporulation. 4. Both activities of inorganic pyrophosphatase and glycerol-2-phosphatase decreased. 5. Conditions necessary for sporulation were suggested. 相似文献
962.
Tetsuya Seki Masafumi Ota Hiroto Hirano Kiyotaka Nakagawa 《Bioscience, biotechnology, and biochemistry》2020,84(9):1870-1885
ABSTRACT
Capsaicinoids are responsible for the pungent flavor of peppers (Capsicum sp.). The cultivar CH-19 Sweet is a non-pungent pepper mutant that biosynthesizes the low-pungent capsaicinoid analogs, capsinoids. Capsinoids possess important pharmaceutical properties. However, capsinoid concentrations are very low in CH-19 Sweet, and Capsicum cultivars with high content capsinoids are desirable for industrial applications of capsinoids. Habanero, Bhut Jolokia, and Infinity are species of Capsicum chinense, and have strong pungency and intense fruity flavors. In the present study, we report new cultivars with high concentrations of capsinoids (more than ten-fold higher than in CH-19 Sweet), and showed that these cultivars (Dieta0011-0301 and Dieta0011-0602 from Bhut Jolokia, Dieta0041-0401 and Dieta0041-0601 from Infinity) are of nutritional and medicinal value and have fruity aromas. We also obtained a vanilla bean flavor, vanillyl alcohol, and vanillyl ethyl ether from capsinoids in the fruit of these cultivars following the addition of ethanol at room temperature. 相似文献
963.
Genes from Nine Genomes Are Separated into Their Organisms in the Dinucleotide Composition Space 总被引:1,自引:0,他引:1
A set of 16 kinds of dinucleotide compositions was used to analyzethe protein-encoding nucleotide sequences in nine complete genomes:Escherichia coli, Haemophilus influenzae, Helicobacter pylori,Mycoplasma genitalium, Mycoplasma pneumoniae, Synechocystissp., Methanococcus jannaschii, Archaeoglobus fulgidus, and Saccharomycescerevisiae. The dinucleotide composition was significantly differentbetween the organisms. The distribution of genes from an organismwas clustered around its center in the dinucleotide compositionspace. The genes from closely related organisms such as Gram-negativebacteria, mycoplasma species and eukaryotes showed some overlapin the space. The genes from nine complete genomes togetherwith those from human were discriminated into respective clusterswith 80% accuracy using the dinucleotide composition alone.The composition data estimated from a whole genome was closeto that obtained from genes, indicating that the characteristicfeature of dinucleotides holds not only for protein coding regionsbut also noncoding regions. When a dendrogram was constructedfrom the disposition of the clusters in the dinucleotide space,it resembled the real phylogenetic tree. Thus, the distinctfeature observed in the dinucleotide composition may reflectthe phylogenetic relationship of organisms. 相似文献
964.
Hidetoshi Ota 《Population Ecology》1998,40(2):189-204
This paper analyzes the phylogeographical patterns of amphibian and reptile lineages distributed in the Ryukyu islands south
of the Tokara Gap on the basis of relevant distributional data and phylogenetic hypotheses hitherto published. Results indicate
the numerical dominance of highly relict lineages in the central Ryukyus, and the occurences of a few more or less relict
lineages in the Miyako Group as well. On the other hand, most species and subspecies endemic to the Yaeyama Group or to the
Yaeyama and Miyako Groups are considered to be direct consequences of vicariance with adjacent regions. Three major hypotheses
regarding the Cenozoic paleogeography of the central and the southern Ryukyus are examined in the light of the present results
and a modified hypothesis is proposed accordingly. 相似文献
965.
966.
Masao Ota Takeshi Seki Kendo Kiyosawa Seiichi Furuta Kunihiko Hino Toshiro Kondo Hirofumi Fuskushima Kimiyoshi Tsuji Hidetoshi Inoko 《Immunogenetics》1992,36(1):49-55
Fifty-one patients with autoimmune hepatitis have been studied for HLA association by conventional serology and also by modified polymerase chain reaction-restriction fragment lenght polymorphism (PCR-RFLP) genotyping.HLA-DR4 was significantly associated with autoimmmune hepatitis (46 of 51 patients, 90.2%). DNA typing of the DRB1 gene for 43 DR4-positive patients by using the PCR-RFLP technique revealed that of 43 patients, 33 had DRB1
*
0405 (Dw15), five had DRB1
*
0406 (DwKT2), four had DRB1
*
0403 (Dw13a), two had DRB1
*
0401 (Dw4), two of 43 had DRB1
*
0407 (Dw13b) and one had DRB1
*
0408 (Dw14b). Thus, there was no significant difference in Dw frequencies between DR4-positive patients and DR4-positive healthy subjects. These findings suggest that the DR4-specific sequence (Val 11 and His 13 at amino acid positions 11 and 13, respectively), but not particular Dw-associated DR4 sequence, in the first domain of the DRB1 chain contributes to susceptibility to autoimmune hepatitis among Japanese. Interestingly, all five of the DR4-negative patients had the DR2 specificity (DRB1
1502 or 1601). Taken together, these results imply that the basic amino acids at position 13, which is present only on the DR2 and DR4 B1 molecules (Arg on DR2 and His on DR4), are most important for determining the predisposition to autoimmune hepatitis.
Address correspondence and offprint requests to: M. Ota. 相似文献
967.
S Ota 《Journal of biochemistry》1966,59(5):463-468
968.
J Nakayama H Ota T Katsuyama M Kanai T Taki Y Hirabayashi Y Suzuki 《Histochemistry》1992,97(4):303-310
Immunohistochemical distributions of carbohydrate antigens based on the type 2 chain in normal as well as fetal and neoplastic tissues of human gastrointestinal tract were investigated with a monoclonal antibody (MAb) H11 (specific for type 2 chain) alone and in combination with the two MAbs MSG15 (for alpha 2----6 sialylated type 2 chain) and IB9 (for the alpha 2----6 sialylated type 2 chain and glycoproteins having NeuAc alpha 2----6Gal-NAc), and 188C1 (for short- and long-chain Lex antigens) and FH2 (for the long-chain Lex antigen). In the pyloric mucosa of secretors, the type 2 chain is oncodevelopmentally expressed, but in non-secretors it is detected in surface mucous cells of normal gastric mucosa. The alpha 2----6 sialylation, which is confined to endocrine cells of normal pyloric mucosa, occurs in fetal and carcinoma tissues. Irrespective of the secretor status, the short- and the long-chain Lex antigens can be detected in mature and immature glandular mucous cells of normal gastric mucosa, respectively; both antigens are also expressed in fetal and carcinoma tissues. In the colon, the type 2 chain and its alpha 2----6 sialylated counterpart are expressed in an oncodevelopmental manner. The short- and the long-chain Lex antigens are significantly enhanced in colonic carcinoma. The glycoproteins with NeuAc alpha 2----6GalNAc residues appear in gastric and colonic carcinoma as well as intestinalized gastric mucosa and transitional mucosa. Thus, some of these antigens were distinctively expressed in certain epithelial cells lining the normal gastrointestinal tract depending on maturation and patients' secretor status, and some were oncodevelopmental or carcinoma-associated antigens of the human gastrointestinal tract. 相似文献
969.
970.