全文获取类型
收费全文 | 1988篇 |
免费 | 42篇 |
专业分类
2030篇 |
出版年
2022年 | 12篇 |
2021年 | 26篇 |
2020年 | 15篇 |
2019年 | 25篇 |
2018年 | 44篇 |
2017年 | 25篇 |
2016年 | 34篇 |
2015年 | 30篇 |
2014年 | 67篇 |
2013年 | 97篇 |
2012年 | 101篇 |
2011年 | 139篇 |
2010年 | 103篇 |
2009年 | 70篇 |
2008年 | 73篇 |
2007年 | 79篇 |
2006年 | 76篇 |
2005年 | 67篇 |
2004年 | 64篇 |
2003年 | 58篇 |
2002年 | 79篇 |
2001年 | 88篇 |
2000年 | 66篇 |
1999年 | 33篇 |
1998年 | 19篇 |
1994年 | 9篇 |
1992年 | 27篇 |
1991年 | 32篇 |
1990年 | 29篇 |
1989年 | 28篇 |
1988年 | 28篇 |
1987年 | 32篇 |
1986年 | 26篇 |
1985年 | 29篇 |
1984年 | 27篇 |
1983年 | 22篇 |
1979年 | 15篇 |
1978年 | 9篇 |
1977年 | 10篇 |
1976年 | 11篇 |
1975年 | 22篇 |
1974年 | 19篇 |
1973年 | 20篇 |
1972年 | 17篇 |
1971年 | 17篇 |
1970年 | 14篇 |
1968年 | 18篇 |
1967年 | 13篇 |
1966年 | 11篇 |
1965年 | 9篇 |
排序方式: 共有2030条查询结果,搜索用时 0 毫秒
51.
Chertkov O Brown PJ Kysela DT de Pedro MA Lucas S Copeland A Lapidus A Del Rio TG Tice H Bruce D Goodwin L Pitluck S Detter JC Han C Larimer F Chang YJ Jeffries CD Land M Hauser L Kyrpides NC Ivanova N Ovchinnikova G Tindall BJ Göker M Klenk HP Brun YV 《Standards in genomic sciences》2011,5(3):287-297
The family Hyphomonadaceae within the Alphaproteobacteria is largely comprised of bacteria isolated from marine environments with striking morphologies and an unusual mode of cell growth. Here, we report the complete genome sequence Hirschia baltica, which is only the second a member of the Hyphomonadaceae with a published genome sequence. H. baltica is of special interest because it has a dimorphic life cycle and is a stalked, budding bacterium. The 3,455,622 bp long chromosome and 84,492 bp plasmid with a total of 3,222 protein-coding and 44 RNA genes were sequenced as part of the DOE Joint Genome Institute Program CSP 2008. 相似文献
52.
Stable differences have been found between haploid and diploid Mikado tomato plants with respect to quantitative characteristics of their vegetative and generative organs, whereas these plants were phenotypically similar with respect to qualitative characteristics, such as the bush habitus and the shapes of leaves, flowers, and fruit. A simple indirect method based on counting the chloroplasts in guard cells has been suggested to diagnose haploids. Analysis of meiosis during microspore formation in haploids has revealed considerable anomalies leading to heterogeneity and a high sterility rate of pollen, which has been confirmed by differences in DNA content. The data obtained suggest that formation of fertile gametes is accounted for by the absence of reduction division. It has been hypothesized that meiosis in haploids induces the genotypic variation that is subject to selection. 相似文献
53.
L. M. Skobeltsyna D. V. Pyshnyi I. G. Shishkina D. R. Tabatadze G. M. Dymshits V. F. Zarytova E. M. Ivanova 《Molecular Biology》2000,34(3):321-327
A new approach for detection of point mutations has been developed. The nonradioactive test system proposed is based on enzymatic
ligation of a tandem of three short oligonucleotides B∼pN8+pN4+pN′8 Bio in the presence of a complementary DNA template. The 5′-terminal octanucleotide B∼pN8 is immobilized on polymer methacrylate beads (B) and the 3′-terminal octanucleotide pN′8 Bio contains a biotin residue at the 3′-phosphate. Ligation of the tandem produces a 20-mer biotinylated oligonucleotide
on a polymer bead, which is then visualized via subsequent treatments with streptavidin-alkaline phosphatase conjugate and
chromogenic substrates. Intense staining of the polymer beads is observed when the amount of DNA template (20-mer oligonucleotide)
is as low as ∼10−14 mol. It is shown that practically no polymer staining is observed when the complex formed by the tandem and the 20-mer DNA
template contains a mismatch either in the tetranucleotide duplex or in the duplex of octanucleotide immobilized on the beads.
This suggests a possibility of using the presented approach in test systems for detection of point mutations in PCR-amplified
DNA fragments. 相似文献
54.
Wayne Reeve Rui Tian Sofie De Meyer Vanessa Melino Jason Terpolilli Julie Ardley Ravi Tiwari John Howieson Ronald Yates Graham O’Hara Mohamed Ninawi Hazuki Teshima David Bruce Chris Detter Roxanne Tapia Cliff Han Chia-Lin Wei Marcel Huntemann James Han I-Min Chen Konstantinos Mavromatis Victor Markowitz Natalia Ivanova Galina Ovchinnikova Ioanna Pagani Amrita Pati Lynne Goodwin Sam Pitluck Tanja Woyke Nikos Kyrpides 《Standards in genomic sciences》2013,9(2):243-253
Rhizobium leguminosarum bv. trifolii strain TA1 is an aerobic, motile, Gram-negative, non-spore-forming rod that is an effective nitrogen fixing microsymbiont on the perennial clovers originating from Europe and the Mediterranean basin. TA1 however is ineffective with many annual and perennial clovers originating from Africa and America. Here we describe the features of R. leguminosarum bv. trifolii strain TA1, together with genome sequence information and annotation. The 8,618,824 bp high-quality-draft genome is arranged in a 6 scaffold of 32 contigs, contains 8,493 protein-coding genes and 83 RNA-only encoding genes, and is one of 20 rhizobial genomes sequenced as part of the DOE Joint Genome Institute 2010 Community Sequencing Program. 相似文献
55.
Ovsiannikova Natalia L. Lavrushkina Svetlana V. Ivanova Anastasia V. Mazina Ludmila M. Zhironkina Oxana A. Kireev Igor I. 《Biochemistry. Biokhimii?a》2021,86(10):1288-1300
Biochemistry (Moscow) - One of the main factors associated with worse prognosis in oncology is metastasis, which is based on the ability of tumor cells to migrate from the primary source and to... 相似文献
56.
57.
Ivanova GD Arzumanov A Abes R Yin H Wood MJ Lebleu B Gait MJ 《Nucleic acids research》2008,36(20):6418-6428
Steric blocking peptide nucleic acid (PNA) oligonucleotides have been used increasingly for redirecting RNA splicing particularly in therapeutic applications such as Duchenne muscular dystrophy (DMD). Covalent attachment of a cell-penetrating peptide helps to improve cell delivery of PNA. We have used a HeLa pLuc705 cell splicing redirection assay to develop a series of PNA internalization peptides (Pip) conjugated to an 18-mer PNA705 model oligonucleotide with higher activity compared to a PNA705 conjugate with a leading cell-penetrating peptide being developed for therapeutic use, (R-Ahx-R)4. We show that Pip–PNA705 conjugates are internalized in HeLa cells by an energy-dependent mechanism and that the predominant pathway of cell uptake of biologically active conjugate seems to be via clathrin-dependent endocytosis. In a mouse model of DMD, serum-stabilized Pip2a or Pip2b peptides conjugated to a 20-mer PNA (PNADMD) targeting the exon 23 mutation in the dystrophin gene showed strong exon-skipping activity in differentiated mdx mouse myotubes in culture in the absence of an added transfection agent at concentrations where naked PNADMD was inactive. Injection of Pip2a-PNADMD or Pip2b-PNADMD into the tibealis anterior muscles of mdx mice resulted in ~3-fold higher numbers of dystrophin-positive fibres compared to naked PNADMD or (R-Ahx-R)4-PNADMD. 相似文献
58.
Anderson I Risso C Holmes D Lucas S Copeland A Lapidus A Cheng JF Bruce D Goodwin L Pitluck S Saunders E Brettin T Detter JC Han C Tapia R Larimer F Land M Hauser L Woyke T Lovley D Kyrpides N Ivanova N 《Standards in genomic sciences》2011,5(1):50-60
Ferroglobus placidus belongs to the order Archaeoglobales within the archaeal phylum Euryarchaeota. Strain AEDII12DO is the type strain of the species and was isolated from a shallow marine hydrothermal system at Vulcano, Italy. It is a hyperthermophilic, anaerobic chemolithoautotroph, but it can also use a variety of aromatic compounds as electron donors. Here we describe the features of this organism together with the complete genome sequence and annotation. The 2,196,266 bp genome with its 2,567 protein-coding and 55 RNA genes was sequenced as part of a DOE Joint Genome Institute Laboratory Sequencing Program (LSP) project. 相似文献
59.
Gorden DL Ivanova PT Myers DS McIntyre JO VanSaun MN Wright JK Matrisian LM Brown HA 《PloS one》2011,6(8):e22775
Background and Aims
The spectrum of nonalcoholic fatty liver disease (NAFLD) includes steatosis, nonalcoholic steatohepatitis (NASH), and progression to cirrhosis. While differences in liver lipids between disease states have been reported, precise composition of phospholipids and diacylglycerols (DAG) at a lipid species level has not been previously described. The goal of this study was to characterize changes in lipid species through progression of human NAFLD using advanced lipidomic technology and compare this with a murine model of early and advanced NAFLD.Methods
Utilizing mass spectrometry lipidomics, over 250 phospholipid and diacylglycerol species (DAGs) were identified in normal and diseased human and murine liver extracts.Results
Significant differences between phospholipid composition of normal and diseased livers were demonstrated, notably among DAG species, consistent with previous reports that DAG transferases are involved in the progression of NAFLD and liver fibrosis. In addition, a novel phospholipid species (ether linked phosphatidylinositol) was identified in human cirrhotic liver extracts.Conclusions
Using parallel lipidomics analysis of murine and human liver tissues it was determined that mice maintained on a high-fat diet provide a reproducible model of NAFLD in regards to specificity of lipid species in the liver. These studies demonstrated that novel lipid species may serve as markers of advanced liver disease and importantly, marked increases in DAG species are a hallmark of NAFLD. Elevated DAGs may contribute to altered triglyceride, phosphatidylcholine (PC), and phosphatidylethanolamine (PE) levels characteristic of the disease and specific DAG species might be important lipid signaling molecules in the progression of NAFLD. 相似文献60.
Turner JJ Fabani M Arzumanov AA Ivanova G Gait MJ 《Biochimica et biophysica acta》2006,1758(3):290-300
New candidates for development as potential drugs or virucides against HIV-1 infection and AIDS continue to be needed. The HIV-1 RNA leader sequence has many essential functional sites for virus replication and regulation that includes several highly conserved sequences. The review describes the historical context of targeting the HIV-1 RNA leader sequence with antisense phosphorothioate oligonucleotides, such as GEM 91, and goes on to describe modern approaches to targeting this region with steric blocking oligonucleotide analogues having newer and more advantageous chemistries, as well as recent studies on siRNA, towards the attainment of antiviral activity. Recent attempts to obtain improved cell delivery are highlighted, including exciting new developments in the use of peptide conjugates of peptide nucleic acid (PNA) as potential virucides. 相似文献