全文获取类型
收费全文 | 163篇 |
免费 | 7篇 |
国内免费 | 2篇 |
出版年
2021年 | 2篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2016年 | 3篇 |
2015年 | 3篇 |
2014年 | 7篇 |
2013年 | 6篇 |
2012年 | 11篇 |
2011年 | 7篇 |
2010年 | 9篇 |
2009年 | 9篇 |
2008年 | 8篇 |
2007年 | 5篇 |
2006年 | 7篇 |
2005年 | 6篇 |
2004年 | 7篇 |
2003年 | 5篇 |
2002年 | 3篇 |
2001年 | 8篇 |
2000年 | 4篇 |
1999年 | 5篇 |
1998年 | 9篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 6篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 5篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1986年 | 2篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有172条查询结果,搜索用时 31 毫秒
1.
2.
Litman GW; Rast JP; Shamblott MJ; Haire RN; Hulst M; Roess W; Litman RT; Hinds- Frey KR; Zilch A; Amemiya CT 《Molecular biology and evolution》1993,10(1):60-72
Immunoglobulins are encoded by a large multigene system that undergoes
somatic rearrangement and additional genetic change during the development
of immunoglobulin-producing cells. Inducible antibody and antibody-like
responses are found in all vertebrates. However, immunoglobulin possessing
disulfide-bonded heavy and light chains and domain-type organization has
been described only in representatives of the jawed vertebrates. High
degrees of nucleotide and predicted amino acid sequence identity are
evident when the segmental elements that constitute the immunoglobulin gene
loci in phylogenetically divergent vertebrates are compared. However, the
organization of gene loci and the manner in which the independent elements
recombine (and diversify) vary markedly among different taxa. One striking
pattern of gene organization is the "cluster type" that appears to be
restricted to the chondrichthyes (cartilaginous fishes) and limits
segmental rearrangement to closely linked elements. This type of gene
organization is associated with both heavy- and light-chain gene loci. In
some cases, the clusters are "joined" or "partially joined" in the germ
line, in effect predetermining or partially predetermining, respectively,
the encoded specificities (the assumption being that these are expressed)
of the individual loci. By relating the sequences of transcribed gene
products to their respective germ-line genes, it is evident that, in some
cases, joined-type genes are expressed. This raises a question about the
existence and/or nature of allelic exclusion in these species. The
extensive variation in gene organization found throughout the vertebrate
species may relate directly to the role of intersegmental
(V<==>D<==>J) distances in the commitment of the individual
antibody-producing cell to a particular genetic specificity. Thus, the
evolution of this locus, perhaps more so than that of others, may reflect
the interrelationships between genetic organization and function.
相似文献
3.
4.
Virologica Sinica - 3h-31 of Heliothis virescens ascovirus 3h (HvAV-3h) is a highly conserved gene of ascoviruses. As an early gene of HvAV-3h, 3h-31 codes for a non-structural protein (3H-31) of... 相似文献
5.
In the present investigation, -galactosidase was solubilized into Aerosol OT (AOT)/isooctane reverse micelles. Kinetic data for the hydrolysis of o-nitrophenyl--D-galactopyranoside (ONPG) at different pH values and molar ratios of water to AOT (Wo) were collected. It was observed that the usual kinetic model used for -galactosidase catalysis in aqueous systems failed to represent the experimental data. A bounded water model, however, showed a better correlation between enzymatic activity and Wo. In contrast to the aqueous system, controlling the water concentration in the reverse micelles allows the rate constants for the reaction between water molecules and glycosyl-enzyme complexes to be evaluated. 相似文献
6.
Background
In addition to known protein-coding genes, large amounts of apparently non-coding sequence are conserved between the human and mouse genomes. It seems reasonable to assume that these conserved regions are more likely to contain functional elements than less-conserved portions of the genome. 相似文献7.
The membrane theory is used to study the recently observed nanomechanical bending of cantilevers, which have processed biomolecular adsorption or biochemical reactions. To be different from entropy-controlling bending mechanism discussed before, we propose that the flexoelectric effect induces cantilever bending. With the introduction of flexoelectric spontaneous curvature, the relation between the bending and biopolymer character is constructed by a simple analytical formula. The cantilever motion induced by adsorption of single-strand DNA and DNA hybridization reaction is quantified analytically and our results show good agreement with experiments. 相似文献
8.
van Dijken JP Bauer J Brambilla L Duboc P Francois JM Gancedo C Giuseppin ML Heijnen JJ Hoare M Lange HC Madden EA Niederberger P Nielsen J Parrou JL Petit T Porro D Reuss M van Riel N Rizzi M Steensma HY Verrips CT Vindeløv J Pronk JT 《Enzyme and microbial technology》2000,26(9-10):706-714
To select a Saccharomyces cerevisiae reference strain amenable to experimental techniques used in (molecular) genetic, physiological and biochemical engineering research, a variety of properties were studied in four diploid, prototrophic laboratory strains. The following parameters were investigated: 1) maximum specific growth rate in shake-flask cultures; 2) biomass yields on glucose during growth on defined media in batch cultures and steady-state chemostat cultures under controlled conditions with respect to pH and dissolved oxygen concentration; 3) the critical specific growth rate above which aerobic fermentation becomes apparent in glucose-limited accelerostat cultures; 4) sporulation and mating efficiency; and 5) transformation efficiency via the lithium-acetate, bicine, and electroporation methods. On the basis of physiological as well as genetic properties, strains from the CEN.PK family were selected as a platform for cell-factory research on the stoichiometry and kinetics of growth and product formation. 相似文献
9.
10.
Fluorescence spectroscopy in combination with UV–Vis absorption spectroscopy were employed to investigate the binding of an
antibacterial drug Ciprofloxacin (CPFX) to bovine serum albumin (BSA) under the physiological conditions. In the discussion
of the quenching mechanism, it was proved that the fluorescence quenching of BSA by CPFX is a result of the formation of CPFX-BSA
complex. Binding parameters were determined using the modified Stern-Volmer equation and Scatchard equation to provide a measure
of the binding affinity between CPFX and BSA. The results of thermodynamic parameters ΔG, ΔH, ΔS, at different temperatures indicate that the electrostatic interactions play a major role for CPFX-BSA association. Site
marker competitive experiments indicated that the binding of CPFX to BSA primarily took place in site I. Furthermore, the
effect of metal ions to CPFX-BSA system was studied, and the distance r between donor (BSA) and acceptor (CPFX) was obtained according to fluorescence resonance energy transfer (FRET). The conformation
of BSA upon CPFX binding was evaluated by measuring synchronous fluorescence properties of the CPFX-BSA complex. 相似文献