全文获取类型
收费全文 | 186篇 |
免费 | 9篇 |
出版年
2021年 | 2篇 |
2020年 | 2篇 |
2019年 | 5篇 |
2018年 | 1篇 |
2017年 | 3篇 |
2016年 | 1篇 |
2015年 | 4篇 |
2014年 | 3篇 |
2013年 | 7篇 |
2012年 | 9篇 |
2011年 | 4篇 |
2010年 | 4篇 |
2009年 | 4篇 |
2008年 | 7篇 |
2007年 | 9篇 |
2006年 | 5篇 |
2005年 | 7篇 |
2004年 | 5篇 |
2003年 | 9篇 |
2002年 | 5篇 |
2001年 | 3篇 |
2000年 | 6篇 |
1999年 | 4篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 5篇 |
1995年 | 5篇 |
1994年 | 6篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 7篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1973年 | 4篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1969年 | 2篇 |
1965年 | 1篇 |
排序方式: 共有195条查询结果,搜索用时 15 毫秒
91.
Lipomyces starkeyi is an oleaginous yeast, and has been classified in four distinct groups, i.e., sensu stricto and custers α, β, and γ. Recently,
L. starkeyi clusters α, β, and γ were recognized independent species, Lipomyces mesembrius, Lipomyces doorenjongii, and Lipomyces kockii, respectively. In this study, we investigated phylogenetic relationships within L. starkeyi, including 18 Japanese wild strains, and its related species, based on internal transcribed spacer sequences and evaluated
biochemical characters which reflected the phylogenetic tree. Phylogenetic analysis showed that most of Japanese wild strains
formed one clade and this clade is more closely related to L. starkeyi s.s. clade including one Japanese wild strain than other clades. Only three Japanese wild strains were genetically distinct
from L. starkeyi. Lipomyces mesembrius and L. doorenjongii shared one clade, while L. kockii was genetically distinct from the other three species. Strains in L. starkeyi s.s. clade converted six sugars, d-glucose, d-xylose, l-arabinose, d-galactose, d-mannose, and d-cellobiose to produce high total lipid yields. The Japanese wild strains in subclades B, C, and D converted d-glucose, d-galactose, and d-mannose to produce high total lipid yields. Lipomyces mesembrius was divided into two subclades. Lipomyces mesembrius CBS 7737 converted d-xylose, l-arabinose, d-galactose, and d-cellobiose, while the other L. mesembrius strains did not. Lipomyces doorenjongii converted all the sugars except d-cellobiose. In comparison to L. starkeyi, L. mesembrius, and L. doorenjongii, L. kockii produced higher total lipid yields from d-glucose, d-galactose, and d-mannose. The type of sugar converted depended on the subclade classification elucidated in this study. 相似文献
92.
Gene duplication of endothelin 3 is closely correlated with the hyperpigmentation of the internal organs (Fibromelanosis) in silky chickens 总被引:1,自引:0,他引:1
Shinomiya A Kayashima Y Kinoshita K Mizutani M Namikawa T Matsuda Y Akiyama T 《Genetics》2012,190(2):627-638
During early development in vertebrates, pluripotent cells are generated from the neural crest and migrate according to their presumptive fate. In birds and mammals, one of the progeny cells, melanoblasts, generally migrate through a dorsolateral route of the trunk region and differentiate to melanocytes. However, Silky is an exceptional chicken in which numerous melanoblasts travel via a ventral pathway and disperse into internal organs. Finally, these ectopic melanocytes induce heavy dermal and visceral melanization known as Fibromelanosis (Fm). To identify the genetic basis of this phenotype, we confirmed the mode of inheritance of Fm as autosomal dominant and then performed linkage analysis with microsatellite markers and sequence-tagged site markers. Using 85 backcross progeny from crossing Black Minorca chickens (BM-C) with F(1) individuals between White Silky (WS) and BM-C Fm was located on 10.2-11.7 Mb of chicken chromosome 20. In addition, we noticed a DNA marker that all Silky chickens and the F(1) individuals showed heterozygous genotyping patterns, suggesting gene duplication in the Fm region. By quantitative real-time PCR assay, Silky line-specific gene duplication was detected as an ~130-kb interval. It contained five genes including endothelin 3 (EDN3), which encoded a potent mitogen for melanoblasts/melanocytes. EDN3 with another three of these duplicated genes in Silky chickens expressed almost twofold of those in BM-C. Present results strongly suggest that the increase of the expression levels resulting from the gene duplication in the Fm region is the trigger of hypermelanization in internal organs of Silky chickens. 相似文献
93.
The topics focusing on functionalization of gold nanorods have been reviewed with a view toward their advanced uses. In most
cases, as-prepared gold nanorods are hydrophilic and protected by surfactants, since anisotropic growth of gold nanorods by
chemical, electrochemical, and photo-induced methods is carried out in aqueous media in the presence of surfactants and additives.
Since solvophilicity of gold nanorods predominantly affects on their optical properties, the control of dispersity of gold
nanorods in matrices has been performed, without loss of their optical characters, by surface modification and hybridization
with small molecules or polymers. As a result of the functionalization procedure, the capability of self-assembly of gold
nanorods has been improved. Furthermore, the examples of application using gold nanorods demonstrate that gold nanorod is
a promising material. 相似文献
94.
95.
We recently identified plant acetylcholinesterases (E.C.3.1.1.7; AChEs) homologous to the AChE purified from a monocotyledon,
maize, that are distinct from the animal AChE family. In this study, we purified, cloned and characterized an AChE from a
dicotyledon, siratro. The full-length cDNA of siratro AChE is 1,441 nucleotides, encoding a 382-residue protein that includes
a signal peptide. This AChE is a disulfide-linked 125-kDa homotrimer consisting of 41–42 kDa subunits, in contrast to the
maize AChE, which exists as a mixture of disulfide and non-covalently linked 88-kDa homodimers. The plant AChEs apparently
consist of various quaternary structures, depending on the plant species, similar to the animal AChEs. We compared the enzymatic
properties of the dimeric maize and trimeric siratro AChEs. Similar to electric eel AChE, both plant AChEs hydrolyzed acetylthiocholine
(or acetylcholine) and propionylthiocholine (or propionylcholine), but not butyrylthiocholine (or butyrylcholine), and their
specificity constant was highest against acetylcholine. There was no significant difference between the enzymatic properties
of trimeric and dimeric AChEs, although two plant AChEs had low substrate turnover numbers compared with electric eel AChE.
The two plant AChE activities were not inhibited by excess substrate concentrations. Thus, similar to some plant AChEs, siratro
and maize AChEs showed enzymatic properties of both animal AChE and animal BChE. On the other hand, both siratro and maize
AChEs exhibited low sensitivity to the AChE-specific inhibitor neostigmine bromide, dissimilar to other plant AChEs. These
differences in enzymatic properties of plant AChEs may reflect the phylogenetic evolution of AChEs.
Kosuke Yamamoto and Yoshie S. Momonoki contributed equally to this work. 相似文献
96.
Y Nagumo H Oguri Y Shindo S Sasaki T Oishi M Hirama Y Tomioka M Mizugaki T Tsumuraya 《Bioorganic & medicinal chemistry letters》2001,11(15):2037-2040
Monoclonal antibodies (mAbs), 4H2 and 6H7, were prepared previously using a protein conjugate of a 1:1 epimeric mixture of the synthetic ABC-ring fragments of ciguatoxin (CTX), 3 and 4. Here, the interactions of these mAbs with the fragments of CTX and CTX3C, 3 and 5, were investigated by surface plasmon resonance (SPR) spectroscopy in an attempt to clarify an antigenic determinant. Compared with the previous synthesis, the fragment 3 possessing the 2S configuration was synthesized from tri-O-acetyl-D-glucal much more effectively. The mAb 4H2 was already known to show a dose-dependent binding to the bovine serum albumin (BSA) conjugate of 3, but not to that of 5. The present SPR study of 4H2 demonstrates that the A-ring side chain of 3 plays a decisive role as an epitope. Therefore, SPR can effectively replace the ELISA method for the analysis of mAbs. 相似文献
97.
The ir spectra of σ–nitrophenylthio-tetra- and hexa-γ-benzyl-L -glutamate ethylamides were measured at different concentrations in chloroform and ethylene dichloride. The molar extinction coefficients of two bands, each for the amide I and A modes, were observed as indicating the content of β structure and the fraction of hydrogen bonds; they were analyzed for elucidating the hydrogen-bonded state of peptide residues in the σ and β conformations of oligopeptides. While the content of β structure of the tetra-peptide increases with increasing concentration, the hexapeptide is in the β conformation above the critical concentration only. The fraction of hydrogen bonds remains finite even at infinite dilution or below the critical concentration, indicating the intramolecular hydrogen-bonding in the σ—form. As the fundamental structure of folded forms having only intramolecular hydrogen bonds, the 27 ribbon is most likely. With increasing concentration or above the critical concentration, the extended forms are stabilized by the intermolecular hydrogen bonds between residues of the β-form. The β-form is present only when intermolecular hydrogen bonds link two residues in an antiparallel way. Possible structures of the oligopeptides in the σ– and β conformations in the two solvents are described briefly. 相似文献
98.
Naito Y Minamihara T Ando A Marutani T Oguri S Nagata Y 《Bioscience, biotechnology, and biochemistry》2001,65(1):86-93
In the early stage of ripening of cherry-tomato fruits (Lycopersicon esculentum var. cherry), the lectin activity increased logarithmically and reached a plateau at day 10 after flowering. During purification of lectin from ripe and unripe fruits, a 42-kDa protein was found abundantly in unripe fruits. The protein cross-reacted with anti-cherry-tomato-lectin serum, retained chitin-binding ability, but showed no lectin activity. Comparative studies between the structure of the lectin and the 42-kDa protein were done. N-Terminal amino acid sequences of the lectin, peptides derived from the S-pyridylethylated lectin, and fragments generated by limited proteolysis of the native lectin showed that the lectin was comprised of three domains, Hyp-rich, Cys-rich, and Gln-rich, and the alignment of them was as this order from the N-terminus. Studies on the 42-kDa protein showed that it contained two of the three domains, Cys-rich and Gln-rich, but the amino acid sequence analysis showed that the protein should be a product of another gene. 相似文献
99.
Proteome analysis of rat hippocampal neurons by multiple large gel two-dimensional electrophoresis 总被引:1,自引:0,他引:1
The goal of the present study was to detect as many protein spots as possible in mammalian cells using two-dimensional gel electrophoresis (2-DE). For proteome analysis, it is of importance to reveal as many proteins as possible. A single standard 2-DE gel (pH 3-10, 18 cm x 20 cm, 13.5% gel) could detect 853 spots from proteins of cultured rat hippocampal neurons when visualized by silver staining. To increase the resolution of the separation and the number of detectable proteins by 2-DE, we utilized seven different narrow pH range immobilized pH gradients in the first dimension. In the second dimension, fourteen long SDS polyacrylamide gels were used: seven 7.5% gels for the separation of high molecular mass proteins (> or = 40 kDa) and seven 13.5% gels for the separation of low molecular mass proteins (< or = 40 kDa). Three hundred and sixty microg of proteins from cultured hippocampal neurons were loaded on to individual gels and visualized by silver staining. All 14 gel images were assembled into a 70 cm x 67 cm cybergel that contained 6677 protein spots, thereby indicating that the utilization of the present strategy led to a 783% increase in the number of detected spots in comparison to the standard procedure. Loading double the amount (720 microg) of proteins on to a 13.5% gel led to a 184% increase in the number of detected spots, thereby indicating that the present strategy has a potential to display more protein spots in the cybergels. 相似文献
100.
Yamamoto M Mise M Matsumoto S Ito S Gohyama N Ishida S Sagara Y Omiecinski CJ Oguri K Yamada H 《Journal of biochemical and molecular toxicology》2004,18(3):124-130
Potential mechanisms were investigated whereby CYP2B18, a cytochrome P450 gene exhibiting high constitutive expression but only low levels of phenobarbital-inducibility in the guinea pig liver, may be differentially regulated versus the highly inducible rat CYP2B2 gene. To comparatively assess potential regulatory sequences associated with CYP2B18, a guinea pig genomic library was screened enabling isolation of the CYP2B18 gene. The genomic screening process resulted in the identification of at least four closely-related CYP2B18 genes, designated here as CYP2B18A-D. Of these isolates, CYP2B18A exhibited sequence identical to that of the CYP2B18 cDNA. Further, the deduced amino acid sequence of the CYP2B18 cDNA was identical to that of N-terminal and internally-derived peptide sequences obtained in this investigation from CYP2B18 protein isolated from guinea pig liver. Genomic structural sequences were derived for CYP2B18A, together with the respective 5'-upstream and intronic regions of the gene. Comparison of the CYP2B18A and CYP2B2 gene sequences revealed the lack of repetitive LINE gene sequences in CYP2B18A, putative silencing elements that effect neighboring genes, although these sequences were present in both 5'-upstream and 3'-downstream regions of CYP2B2. We determined that the phenobarbital-responsive enhancer module was absent from the 5'-upstream region as well as the intronic regions of CYP2B18A gene. We hypothesize that the compromised phenobarbital inducibility of CYP2B18A stems from its lack of a functional phenobarbital responsive enhancer module. 相似文献