全文获取类型
收费全文 | 393篇 |
免费 | 16篇 |
出版年
2021年 | 7篇 |
2020年 | 4篇 |
2019年 | 5篇 |
2018年 | 10篇 |
2017年 | 4篇 |
2016年 | 8篇 |
2015年 | 13篇 |
2014年 | 13篇 |
2013年 | 24篇 |
2012年 | 24篇 |
2011年 | 18篇 |
2010年 | 7篇 |
2009年 | 10篇 |
2008年 | 9篇 |
2007年 | 19篇 |
2006年 | 15篇 |
2005年 | 13篇 |
2004年 | 13篇 |
2003年 | 13篇 |
2002年 | 22篇 |
2001年 | 9篇 |
2000年 | 9篇 |
1999年 | 6篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 4篇 |
1995年 | 6篇 |
1994年 | 2篇 |
1993年 | 5篇 |
1992年 | 20篇 |
1991年 | 3篇 |
1990年 | 9篇 |
1989年 | 7篇 |
1988年 | 2篇 |
1987年 | 5篇 |
1986年 | 4篇 |
1985年 | 7篇 |
1984年 | 2篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1979年 | 6篇 |
1978年 | 2篇 |
1976年 | 2篇 |
1974年 | 4篇 |
1973年 | 3篇 |
1972年 | 3篇 |
1971年 | 5篇 |
1970年 | 2篇 |
排序方式: 共有409条查询结果,搜索用时 437 毫秒
11.
N Taniguchi K Yanagisawa A Makita M Naiki 《The Journal of biological chemistry》1985,260(8):4908-4913
The enzyme which catalyzes the transfer of galactose from UDP-galactose to lactosylceramide (LacCer) was obtained in a 32,000-fold purified and apparently homogeneous form from rat liver by a procedure involving affinity chromatography on UDP-hexanolamine-Sepharose and LacCer-Sepharose. The enzyme is composed of two nonidentical subunits whose apparent molecular weights are 65,000 and 22,000. Methylation and hydrolysis of the product formed by incubation of the enzyme with UDP-galactose and [3H]LacCer yielded 2,3,6-tri-O-methyl-[3H]galactose, indicating that a galactose residue was introduced to position C-4 of the terminal galactose of the LacCer. The product also specifically reacted with monoclonal antibody directed to globotriaosylceramide (Gal alpha 1-4Gal beta 1-4Glc beta 1-1Cer). This indicates that the purified enzyme is exclusively alpha 1-4-galactosyltransferase. Studies on substrate specificity indicate that the purified enzyme is highly specific for the synthesis of GbOse3Cer and is clearly distinct from the enzymes responsible for the formation of iGbOse3Cer (Gal alpha 1-3Gal beta 1-4Glc-Cer) and blood group-B substance, which possess alpha 1-3 galactosidic linkages at the nonreducing termini. The enzyme is also distinct from the alpha 1-4-galactosyltransferase which catalyzes the formation of galabiaosylceramide (Gal alpha 1-4Gal beta 1-1Cer) and IV4Gal-nLacOse4 (P1 antigen). These studies represent the first report of the properties of a highly purified alpha-galactosyltransferase catalyzing the transfer of sugar residues to glycolipids. 相似文献
12.
Arylsulfatase a from normal human lung and lung tumors showed different patterns of microheterogeneity 总被引:1,自引:0,他引:1
Arylsulfatase A was purified from human lung to apparent homogeneity as determined by electrophoresis in the presence of sodium dodecyl sulfate. The enzyme from normal lung as well as that from lung adenocarcinoma showed considerable microheterogeneity when examined by isoelectric focussing, with an isoelectric point (pI) ranging from 5.1 to 4.6. The tumor enzyme was more heterogeneous and contained more acidic components than the normal lung enzyme. The cause of the charge heterogeneity was examined by treatment with exogenous hydrolases. Upon treatment with sialidase, phosphatase or endo-beta-N-acetylglucosaminidase H (endoglycosidase H), the acidic enzyme forms shifted to an alkaline region on isoelectric focussing gels. Combined treatment of the arylsulfatase A with endoglycosidase H and sialidase resulted in complete loss of the most acidic components to give the less acidic components with pI 5.1, 5.0, and 4.9. These results strongly suggest that the charge heterogeneity of arylsulfatase A is due not only to sialylation but also to phosphorylation at the carbohydrate moiety of the enzyme, and the extent of substitution by acidic groups is markedly increased in the tumor enzyme. 相似文献
13.
Possible site of flavonoid synthesis in the photosynthetic apparatus (Short Communication) 下载免费PDF全文
Koshi Saito 《The Biochemical journal》1974,144(2):431-432
Chloroplasts were prepared in aqueous suspension from buckwheat (Fagopyrum esculentum Moench.) seedlings, and the incorporation of [1-(14)C]acetic acid into quercetin (3,5,7,3',4'-pentahydroxyflavone) by the isolated chloroplast preparations was investigated. 相似文献
14.
T Koshi T Edano K Arai C Suzuki Y Ehara M Hirata M Ohkuchi T Okabe 《Biochemical and biophysical research communications》1992,186(3):1322-1326
Injection of 0.3 nmol/kg endothelin(ET)-1 into the ear vein of conscious rabbits induced a significant increase in body temperature. ETB receptor specific agonist, namely 4-Ala-ET-1, also caused an elevation of the body temperature in a dose-dependent manner by injection into the ear vein of rabbit. These results suggest that ET play important roles in regulation of body temperature through selective stimulation of ETB receptor. 相似文献
15.
Using a maximum-likelihood formalism, we have developed a method with which to reconstruct the sequences of ancestral proteins. Our approach allows the calculation of not only the most probable ancestral sequence but also of the probability of any amino acid at any given node in the evolutionary tree. Because we consider evolution on the amino acid level, we are better able to include effects of evolutionary pressure and take advantage of structural information about the protein through the use of mutation matrices that depend on secondary structure and surface accessibility. The computational complexity of this method scales linearly with the number of homologous proteins used to reconstruct the ancestral sequence. 相似文献
16.
Suzuki Y Murakami T Kawakubo K Haruna Y Takenaka K Goto S Makita Y Ikawa S Gunji A 《Journal of gravitational physiology : a journal of the International Society for Gravitational Physiology》1994,1(1):P57-P58
To this day, many studies have suggested that prolonged bed rest (BR) affects on muscle mass and strength not only in gravity muscles but also in ungravity muscles. However, it is still unclear whether the decrease in regional muscle strength after BR is due to the alterations in the corresponding muscle mass, or not. On the other hand, if BR decreases the mass of antigravity muscles (UGM) as well as muscle strength and then increases tissue compliance of the antigravity muscles, orthostatic tolerance capacity will be decreased by the reduction in cardiac output (CO) in spite of the increase in myocardial contractility because the more decrease in venous return due to the more increase in blood pooling within the compliant tissues of the lower body. However, this is also unclear. To make these questions clear, the present study investigated the regional muscle mass and strength and orthostatic tolerance capacity before and after 20 days of bed rest in young subjects. 相似文献
17.
Akifumi Makita Yasuo Konno Noboru Fujita Ken′ichi Takada Etsuji Hamabata 《Ecological Research》1993,8(2):215-224
The recovery process of aSasa tsuboiana population after a mass flowering and death in 1977 was investigated by 15 years of observation in the Hira Mountains, Kinki
district, western Japan. Seed production was high (6600–13 800 seeds m−2 inSasa plots and 3900 seeds m−2 in a forest plot) but emergent seedling density was low (14–21 seedlings m−2), probably because of seed predation byMicrotus montebelli occurring between seed shedding and the next spring. The seedling density had decreased further by the next year and theS. tsuboiana population recovered from only a limited number of seedlings. In spite of such a low initial density, theS. tsuboiana population was able to regenerate successfully and attained the previous full stand height in 7–16 years.Miscantbus sinensis invaded and delayed the recovery ofS. tsuboiana in one plot, butS. tsuboiana became dominant as it caught up with the height ofM. sinensis. Seedling growth patterns, such as frequent tillering, the onset of rhizome extension in the early stage of seedling growth
and frequent culm production from rhizomes, played important roles in the successful regeneration ofS. tsuboiana. 相似文献
18.
Yukio Takahata Naoki Koyama Michael A. Huffman Koshi Norikoshi Hisayo Suzuki 《Primates; journal of primatology》1995,36(4):571-574
Based on a sample of 237 live births recorded over a period of 30 years, a tendency for longer interbirth intervals following
the birth of daughters than sons was recognized, in the provisioned Arashiyama troop of Japanese macaques. This may indicate
that female infants were more costly to produce than male infants. This tendency seemed to be independent of a mother’s rank. 相似文献
19.
Nobukazu Araki Yoichiro Takashima Takashi Makita 《Histochemistry and cell biology》1995,104(4):257-265
The redistribution and fate of colchicine-induced alkaline phosphatase (ALPase) in rat hepatocytes were investigated by electron microscopic enzyme cytochemistry and biochemistry. ALPase activity markedly increased in rat hepatocytes after colchicine treatment (2.0 mg/kg body weight, intraperitoneal injection). At 20–24 h after colchicine treatment, the liver showed the highest activity of ALPase. Thereafter, ALPase activity decreased and returned to normal levels at 48 h. In normal hepatocytes from control rats, ALPase activity was seen only on the bile canalicular membrane. However, at 20–24 h after colchicine treatment, colchicine-induced ALPase was redistributed in the sinusoidal and lateral (basolateral) membranes as well as in the bile canalicular membrane. At 30–36 h after colchicine treatment, ALPase activity on the basolateral membrane gradually decreased. In contrast, ALPase in the bile canalicular membrane increased along with the enlargement of bile canaliculi, suggesting that ALPase in the basolateral membrane had been transported to the bile canalicular membrane. Furthermore, ALPase-positive vesicles, cisternae and autophagosome-like structures were frequently seen in the cytoplasm. ALPase was also positive in some lysosomal membranes. ALPase in hepatocytes at 48 h after colchicine treatment returned to almost the same location as in control hepatocytes. Altogether, it is suggested that excessively induced ALPase is at least partially retrieved by invagination of the bile canalicular membrane and then transported to lysosomes for degradation. In addition, this study indicates that excess plasma membrane might be a possible origin of autophagosomal membrane. 相似文献
20.
Koshi Saito Hamako Obata-Sasamoto Shin-Ichi Hatanaka Hiroshi Noguchi Ushio Sankawa Atsushi Komamine 《Phytochemistry》1982,21(2):474-476
Isolation and identification of l-3-carboxy-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline and l-1-methyl-3-carboxy-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline from seeds and callus of S. hassjoo are described. Administration of [β-14C]-labelled DOPA to a callus culture of this legume resulted in the incorporation of radioactivity into l-3-carboxy-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline, l-1-methyl-3-carboxy-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline and stizolobic acid, which was confirmed by constant specific radioactivity after co-crystallization with authentic samples of each compound. 相似文献