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111.
112.
A tomato cDNA inducible by salt stress and abscisic acid: nucleotide sequence and expression pattern 总被引:2,自引:0,他引:2
We have characterized a new tomato cDNA, TAS14, inducible by salt stress and abscisic acid (ABA). Its nucleotide sequence predicts an open reading frame coding for a highly hydrophilic and glycine-rich (23.8%) protein of 130 amino acids. Southern blot analysis of tomato DNA suggests that there is one TAS14 structural gene per haploid genome. TAS14 mRNA accumulates in tomato seedlings upon treatment with NaCl, ABA or mannitol. It is also induced in roots, stems and leaves of hydroponically grown tomato plants treated with NaCl or ABA. TAS14 mRNA is not induced by other stress conditions such as cold and wounding. The sequence of the predicted TAS14 protein shows four structural domains similar to the rice RAB21, cotton LEA D11 and barley and maize dehydrin genes. 相似文献
113.
The genomic organization and chromosomal location of theβ-tubulin isogenes inLeishmania donovani promastigotes has been studied by nucleic acid hybridization techniques using a cloned β-tubulin gene. We have cloned aβ-tubulin gene fragment, 3.3 kbp long, from genomic DNA ofLeishmania donovani using a heterologousβ-tubulin DNA as probe. Restriction maps of this clone have been prepared. It has been estimated that there are approximately
11–15 copies of theβ-tubulin genes per haploid genome. The majority of these isogenes are arranged in a tandem repeat with a length of 3.5 kbp
on a single chromosome. In addition a few dispersed gene copies at different chromosomal loci were detected by pulse field
gradient gel electrophoresis. Part of the internal coding region of the gene has been sequenced to confirm the identity of
theβ-tubulin clone and is found to be nearly identical to that ofLeishmania mexicana amazonensis. 相似文献
114.
Dianna M. Milewicz Peter H. Byers John Reveille Austin L. Hughes Madeleine Duvic 《Journal of molecular evolution》1996,42(2):117-123
Alu elements are a class of repetitive DNA sequences found throughout the human genome that are thought to be duplicated via an RNA intermediate in a process termed retroposition. Recently inserted Alu elements are closely related, suggesting that they are derived from a single source gene or closely related source genes. Analysis of the type III collagen gene (COL3A1) revealed a polymorphic Alu insertion in intron 8 of the gene. The Alu insertion in the COL3A1 gene had a high degree of nucleotide identity to the Sb family of Alu elements, a family of older Alu elements. The Alu sequence was less similar to the consensus sequence for the PV or Sb2 subfamilies, subfamilies of recently inserted Alu elements. These data support the observations that at least three source genes are active in the human genome, one of which is distinct from the PV and Sb2 subfamilies and predates either of these two subfamilies. Appearance of the Alu insertion in different ethnic populations suggests that the insertion may have occurred in the last 100,000 years. This Alu insert should be a useful marker for population studies and for marking COL3A1 alleles. 相似文献
115.
David M. Hwang Adam Dempsey Kiat-Tsong Tan Choong-Chin Liew 《Journal of molecular evolution》1996,43(5):536-540
HnifU, a gene exhibiting similarity tonifU genes of nitrogen fixation gene clusters, was identified in the course of expressed sequence tag (EST) generation from a
human fetal heart cDNA library. Northern blot of human tissues and polymerase chain reaction (PCR) using human genomic DNA
verified that the hnifU gene represented a human gene rather than a microbial contaminant of the cDNA library. Conceptual translation of the hnifU cDNA yielded a protein product bearing 77% and 70% amino acid identity to NifU-like hypothetical proteins fromHaemophilus influenzae andSaccharomyces cerevisiae, respectively, and 40–44% identity to the N-terminal regions of NifU proteins from several diazatrophs (i.e., nitrogen-fixing
organisms). Pairwise determination of amino acid identities between the NifU-like proteins of nondiazatrophs showed that these
NifU-like proteins exhibited higher sequence identity to each other (63–77%) than to the diazatrophic NifU proteins (40–48%).
Further, the NifU-like proteins of non-nitrogenfixing organisms were similar only to the N-terminal region of diazatrophic
NifU proteins and therefore identified a novel modular domain in these NifU proteins. These findings support the hypothesis
that NifU is indeed a modular protein. The high degree of sequence similarity between NifU-like proteins from species as divergent
as humans andH. influenzae suggests that these proteins perform some basic cellular function and may be among the most highly conserved proteins.
Correspondence to: C.-C. Liew 相似文献
116.
Six naturally occurring but rare alleles of sn-glycerol-3-phosphate dehydrogenase (Gpdh) in Drosophila melanogaster have been investigated in this study. They all belong to a class of Gpdh
UF
(ultra-fast) alleles, because their electrophoretic mobilities are faster than that of the Gpdh
F
(fast) allele. The Gpdh
UF
variants are widespread, and have been reported from five continents. DNA sequence analysis has shown that the change in electrophoretic mobility was in each allele caused by a single amino acid residue substitution in the encoded protein. In the Xiamen
UF
allele it is a substitution of lysine (AAA) to asparagine (AAT) in exon 1 (residue 3). An asparagine (AAT) to aspartate (GAT) change was found in exon 6 (residue 336) in the Iowa
UF
and Netherlands
UF
alleles. The mobility of the Raleigh
UF
allele was altered by a valine (GTG) to glutamate (GAG) substitution in exon 3 (residue 76). Two mutations were detected in the Brazzaville
UF
allele: a lysine (AAG) to methionine (ATG) substitution in exon 2 (residue 68) is responsible for the ultra-fast phenotype of this variant, while a tyrosine (TAT) to phenylalanine (TTT) substitution in exon 4 (residue 244) is not expected to alter the electrophoretic mobility of the encoded protein. These results indicate that the Gpdh
UF
alleles originate from different mutational events, and only two of them — Iowa
UF
and Netherlands
UF
— might share a common ancestry. The GPDH activity of the Iowa
UF
allele is intermediate between those of the Gpdh
S
and Gpdh
F
control stocks. The other Gpdh
UF
variants have lower activities than the controls: Xiamen
UF
-83%, Raleigh
UF
-80% and Brazzaville
UF
-73% of the Gpdh
F
control. 相似文献
117.
Pegasus, a novel transposable element, was discovered as a length polymorphism in the white gene of Anopheles gambiae. Sequence analysis revealed that this 535 bp element was flanked by 8 bp target site duplications and 8 bp perfect terminal inverted repeats similar to those found in many members of the Tcl family. Its small size and lack of long open reading frames preclude protein coding capacity. Southern analysis and in situ hybridization to polytene chromosomes demonstrated that Pegasus occurs in approximately 30 copies in the genomes of An. gambiae and its sibling species and is homogenous in structure but polymorphic in chromosomal location. Characterization of five additional elements by sequencing revealed nucleotide identities of 95% to 99%. Of 30 Pegasus-containing phage clones examined by PCR, only one contained an element exceeding 535 bp in length, due to the insertion of another transposable element-like sequence. Thus, the majority, if not all, extant Pegasus elements may be defective copies of a complete element whose contemporary existence in An. gambiae is uncertain. No Pegasus-hybridizing sequences were detected in nine other anophelines and three culicines examined, suggesting a very limited taxonomic distribution. 相似文献
118.
L. Zavalova S. Lukyanov I. Baskova E. Snezhkov S. Akopov S. Berezhnoy E. Bogdanova E. Barsova E. D. Sverdlov 《Molecular & general genetics : MGG》1996,253(1-2):20-25
We previously detected in salivary gland secretions of the medicinal leech (Hirudo medicinalis) a novel enzymatic activity, endo-ɛ(γ-Glu)-Lys isopeptidase, which cleaves isopeptide bonds formed by transglutaminase (Factor
XIIIa) between glutamine γ-carboxamide and the ɛ-amino group of lysine. Such isopeptide bonds, either within or between protein
polypeptide chains are formed in many biological processes. However, before we started our work no enzymes were known to be
capable of specifically splitting isopeptide bonds in proteins. The isopeptidase activity we detected was specific for isopeptide
bonds. The enzyme was termed destabilase. Here we report the first purification of destabilase, part of its amino acid sequence,
isolation and sequencing of two related cDNAs derived from the gene family that encodes destabilase proteins, and the detection
of isopeptidase activity encoded by one of these cDNAs cloned in a baculovirus expression vector. The deduced mature protein
products of these cDNAs contain 115 and 116 amino acid residues, including 14 highly conserved Cys residues, and are formed
from precursors containing specific leader peptides. No homologous sequences were found in public databases.
Received: 9 April 1996 / Accepted: 17 May 1996 相似文献
119.
Development of microsatellite markers and characterization of simple sequence length polymorphism (SSLP) in rice (Oryza sativa L.) 总被引:26,自引:0,他引:26
Microsatellite markers containing simple sequence repeats (SSR) are a valuable tool for genetic analysis. Our objective is to augment the existing RFLP map of rice with simple sequence length polymorphisms (SSLP). In this study, we describe 20 new microsatellite markers that have been assigned to positions along the rice chromosomes, characterized for their allelic diversity in cultivated and wild rice, and tested for amplification in distantly related species. Our results indicate that the genomic distribution of microsatellites in rice appears to be random, with no obvious bias for, or clustering in particular regions, that mapping results are identical in intersubspecific and interspecific populations, and that amplification in wild relatives ofOryza sativa is reliable in species most closely related to cultivated rice but becomes less successful as the genetic distance increases. Sequence analysis of SSLP alleles in three relatedindica varieties demonstrated the clustering of complex arrays of SSR motifs in a single 300-bp region with independent variation in each. Two microsatellite markers amplified multiple loci that were mapped onto independent rice chromosomes, suggesting the presence of duplicated regions within the rice genome. The availability of increasing numbers of mapped SSLP markers can be expected to increase the power and resolution of genome analysis in rice. 相似文献
120.
Linker insertion analysis of the FimH adhesin of type 1 fimbriae in an Escherichia coli fimH-null background 总被引:2,自引:0,他引:2
Mark A. Schembri Lars Pallesen Hugh Connell David L. Hasty Per Klemm 《FEMS microbiology letters》1996,137(2-3):257-263
Abstract The gene encoding the Escherichia coli FimH adhesin of type 1 fimbriae has been subjected to linker insertion mutagenesis. Amino acid changes were introduced at a number of positions spanning the entire sequence in order to probe the structure-function relationship of the FimH protein. The effect of these mutations on the ability of bacteria to express a D-mannose binding phenotype was assessed in a fimH null mutant (MS4) constructed by allelic exchange in the E. coli K-12 strain PC31. Mutations mapping at amino acid residues 36, 58 and 279 of the mature FimH protein were shown to completely abolish binding to D-mannose receptors. Differences in the level of fimbriation were also observed as a result of some of the mutations in the fimH gene. These mutants may prove useful in dissecting receptor-ligand interactions by defining regions of the FimH protein that are important in erythrocyte binding. 相似文献