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101.
Lachlan H. Yee Vibeke Aagaard Angela Johnstone Matthew Lee Staffan J. Kjelleberg Mike Manefield 《Biodegradation》2010,21(6):947-956
The biodegradation of chlorinated organics in vadose zone soils is challenging owing to the presence of oxygen, which inhibits
reductive dehalogenation reactions and consequently the growth of dehalorespiring microbes. In addition, the hydraulic conductivity
of vadose zone soils is typically high, hence attempts to remediate such zones with biostimulation solutions are often unsuccessful
due to the short residence times for these solutions to act upon the native bacterial community. In this study we have identified
sodium alginate as a hydrogel polymer that can be used to increase the residence time of a nutrient solution in an unsaturated
sandy soil. Additionally we have identified neutral red as a redox active compound that can catalyse the reductive dechlorination
of the chlorinated organic hexachloro-1,3-butadiene by activated sludge fed with lactate and acetate. Finally we have shown
that a nutrient solution amended with neutral red and sodium alginate can lower the redox potential and reduce hexachloro-1,3-butadiene
concentrations in a contaminated vadose zone soil. 相似文献
102.
Adam C. Naj Gary W. Beecham Eden R. Martin Paul J. Gallins Eric H. Powell Ioanna Konidari Patrice L. Whitehead Guiqing Cai Vahram Haroutunian William K. Scott Jeffery M. Vance Michael A. Slifer Harry E. Gwirtsman John R. Gilbert Jonathan L. Haines Joseph D. Buxbaum Margaret A. Pericak-Vance 《PLoS genetics》2010,6(9)
Genome-wide association studies (GWAS) of late-onset Alzheimer disease (LOAD) have consistently observed strong evidence of association with polymorphisms in APOE. However, until recently, variants at few other loci with statistically significant associations have replicated across studies. The present study combines data on 483,399 single nucleotide polymorphisms (SNPs) from a previously reported GWAS of 492 LOAD cases and 496 controls and from an independent set of 439 LOAD cases and 608 controls to strengthen power to identify novel genetic association signals. Associations exceeding the experiment-wide significance threshold () were replicated in an additional 1,338 cases and 2,003 controls. As expected, these analyses unequivocally confirmed APOE''s risk effect (rs2075650, ). Additionally, the SNP rs11754661 at 151.2 Mb of chromosome 6q25.1 in the gene MTHFD1L (which encodes the methylenetetrahydrofolate dehydrogenase (NADP+ dependent) 1-like protein) was significantly associated with LOAD (; Bonferroni-corrected P = 0.022). Subsequent genotyping of SNPs in high linkage disequilibrium () with rs11754661 identified statistically significant associations in multiple SNPs (rs803424, P = 0.016; rs2073067, P = 0.03; rs2072064, P = 0.035), reducing the likelihood of association due to genotyping error. In the replication case-control set, we observed an association of rs11754661 in the same direction as the previous association at P = 0.002 ( in combined analysis of discovery and replication sets), with associations of similar statistical significance at several adjacent SNPs (rs17349743, P = 0.005; rs803422, P = 0.004). In summary, we observed and replicated a novel statistically significant association in MTHFD1L, a gene involved in the tetrahydrofolate synthesis pathway. This finding is noteworthy, as MTHFD1L may play a role in the generation of methionine from homocysteine and influence homocysteine-related pathways and as levels of homocysteine are a significant risk factor for LOAD development. 相似文献
103.
Kent Langel Staffan Lindberg Dana Copolovici Piret Arukuusk Rannar Sillard Űlo Langel 《International journal of peptide research and therapeutics》2010,16(4):247-255
Cell-penetrating peptides (CPPs) are able to efficiently internalize into cells and can therefore be used as vectors for non-viral
cellular delivery of different cargoes. Previous studies have shown that hydrophobic modifications of different CPPs can increase
their transfection efficiency dramatically. In this study we have modified the cell penetrating-peptide transportan 10 (TP10)
with a variety of hydrophobic molecules to determine the role of hydrophobicity in the uptake of these molecules. The results
can be used to synthesize more efficient delivery vectors. To evaluate how these constructs are able to transport cargoes
into cells we used 2′-OMe splice correcting oligonucleotides. Non-covalent peptide-cargo complexes were formed and their transfection
efficiency was measured using a luciferase readout system. The hydrophobicity of the novel modifications was correlated with
their biological efficacy. We determined the most efficient range of hydrophobicity for TP10 analogs for delivering oligonucleotides
into cells. In order to assess how the transfection efficacy of these particles is dependent on their size the hydrodynamic
diameter of the formed nanoparticles was measured using dynamic light scattering. These findings will be used to develop highly
efficient non-viral gene therapy vectors. 相似文献
104.
Philip D. Round Bengt Hansson David J. Pearson Peter R. Kennerley Staffan Bensch 《Journal of avian biology》2007,38(2):133-138
We present compelling evidence of the continued existence of the large-billed reed warbler Acrocephalus orinus , hitherto known only from the unique type specimen collected in NW India 139 years ago. Morphological and genetic analyses of an unusual Acrocephalus warbler mist-netted south-west of Bangkok, Thailand, on 27 March 2006, confirmed its identity as A. orinus , and revealed that it was heterozygous at four out of eight microsatellite markers, indicating the continued existence of a viable population whose breeding and wintering areas are still unknown. 相似文献
105.
Molecular investigation of the distribution, abundance and diversity of the genus Pseudoalteromonas in marine samples 总被引:3,自引:0,他引:3
The genus Pseudoalteromonas has attracted interest because it has frequently been found in association with eukaryotic hosts, and because many Pseudoalteromonas species produce biologically active compounds. One distinct group of Pseudoalteromonas species is the antifouling subgroup containing Pseudoalteromonas tunicata and Ps. ulvae, which both produce extracellular compounds that inhibit growth and colonization by different marine organisms. PCR primers targeting the 16S rRNA gene of the genus Pseudoalteromonas and the antifouling subgroup were developed and applied in this study. Real-time quantitative PCR (qPCR) was applied to determine the relative bacterial abundance of the genus and the antifouling subgroup, and denaturing gradient gel electrophoresis (DGGE) was applied to study the diversity of the genus in 11 different types of marine samples from Danish coastal waters. The detection of Ps. tunicata that contain the antifouling subgroup was achieved through specific PCR amplification of the antibacterial protein gene (alpP). The Pseudoalteromonas species accounted for 1.6% of the total bacterial abundance across all samples. The Pseudoalteromonas diversity on the three unfouled marine organisms Ciona intestinalis, Ulva lactuca and Ulvaria fusca was found to be low, and Ps. tunicata was only detected on these three hosts, which all contain accessible cellulose polymers in their cell walls. 相似文献
106.
Englund H Sehlin D Johansson AS Nilsson LN Gellerfors P Paulie S Lannfelt L Pettersson FE 《Journal of neurochemistry》2007,103(1):334-345
Amyloid-beta (Abeta) protofibrils are known intermediates of the in vitro Abeta aggregation process and the protofibrillogenic Arctic mutation (APPE693G) provides clinical support for a pathogenic role of Abeta protofibrils in Alzheimer's disease (AD). To verify their in vivo relevance and to establish a quantitative Abeta protofibril immunoassay, Abeta conformation dependent monoclonal antibodies were generated. One of these antibodies, mAb158 (IgG2a), was used in a sandwich ELISA to specifically detect picomolar concentrations of Abeta protofibrils without interference from Abeta monomers or the amyloid precursor protein (APP). The specificity and biological significance of this ELISA was demonstrated using cell cultures and transgenic mouse models expressing human APP containing the Swedish mutation (APPKN670/671ML), or the Swedish and Arctic mutation in combination. The mAb158 sandwich ELISA analysis revealed presence of Abeta protofibrils in both cell and animal models, proving that Abeta protofibrils are formed not only in vitro, but also in vivo. Furthermore, elevated Abeta protofibril levels in the Arctic-Swedish samples emphasize the usefulness of the Arctic mutation as a model of enhanced protofibril formation. This assay provides a novel tool for investigating the role of Abeta protofibrils in AD and has the potential of becoming an important diagnostic assay. 相似文献
107.
Dennis Hasselquist ?rjan ?stman Jonas Waldenstr?m Staffan Bensch 《Journal of Ornithology》2007,148(4):401-409
We studied the prevalence and intensity of the haemosporidian blood parasite Haemoproteus payevskyi in great reed warblers at Lake Kvismaren (6 years) and Lake Segersj? (3 years) in Sweden. Based on microscopic inspection
of slides from 282 adult birds, 20.6% showed infection of H. payevskyi in circulating red blood cells in at least 1 year. For parasite prevalence, there was no difference between years, sex, and
age classes. However, parasite intensity was higher in females than in males, and this was most pronounced in 1-year-old birds.
Individuals scored to carry parasites in year
n
were more likely to show parasite infection year
n + 1 than birds scored to be parasite-free in year
n
. None of 99 juvenile birds examined at the breeding site in late summer, 4–9 weeks after hatching, showed infection of H. payevskyi. Parasite intensity in infected adult birds decreased in the course of the breeding season and no new or relapse infections
were observed during this period. Thus, our data imply that in the great reed warbler, a long-distance migrant to tropical
Africa, transmission of H. payevskyi occurs on wintering sites or at stopover sites during migration. 相似文献
108.
Neutrophil extracellular traps (NETs) are considered to be part of the human innate immunity because they trap and kill pathogens. NETs are formed by activated neutrophils and consist of a DNA backbone with embedded antimicrobial peptides and enzymes. They are involved in host defense during pneumococcal pneumonia, streptococcal necrotizing fasciitis, appendicitis and insemination. Recently, bacterial virulence factors that counteract NETs have been identified. These include the degradation of the NET-backbone by DNases enabling the liberation of bacteria from NETs, as well as capsule formation, which reduces bacterial trapping. Furthermore, pathogens can resist NET-mediated killing by adding positive charge to their cell surface. 相似文献
109.
Albiger B Dahlberg S Sandgren A Wartha F Beiter K Katsuragi H Akira S Normark S Henriques-Normark B 《Cellular microbiology》2007,9(3):633-644
Toll-like receptor 9 (TLR9) induces an inflammatory response by recognition of unmethylated CpG dinucleotides, mainly present in prokaryotic DNA. So far, TLR9-deficient mice have been shown to be more sensitive than wild-type mice to viral, but not to bacterial infections. Here, we show that mice deficient in TLR9 but not in TLR1, TLR2, TLR4 and TLR6 or IL-1R/IL-18R are more susceptible to a respiratory tract bacterial infection caused by Streptococcus pneumoniae. Intranasal challenge studies revealed that TLR9 plays a protective role in the lungs at an early stage of infection prior to the entry of circulating inflammatory cells. Alveolar as well as bone marrow-derived macrophages deficient in either TLR9 or the myeloid adaptor differentiation protein MyD88 were impaired in pneumococcal uptake and in pneumococcal killing. Our data suggest that in the airways, pneumococcal infection triggers a TLR9 and MyD88-dependent activation of phagocytic activity from resident macrophages leading to an early clearance of bacteria from the lower respiratory tract. 相似文献
110.
Sandra Muschiol Murat Balaban Staffan Normark Birgitta Henriques‐Normark 《BioEssays : news and reviews in molecular, cellular and developmental biology》2015,37(4):426-435
Transport of DNA across bacterial membranes involves complex DNA uptake systems. In Gram‐positive bacteria, the DNA uptake machinery shares fundamental similarities with type IV pili and type II secretion systems. Although dedicated pilus structures, such as type IV pili in Gram‐negative bacteria, are necessary for efficient DNA uptake, the role of similar structures in Gram‐positive bacteria is just beginning to emerge. Recently two essentially very different pilus structures composed of the same major pilin protein ComGC were proposed to be involved in transformation of the Gram‐positive bacterium Streptococcus pneumoniae – one is a long, thin, type IV pilus‐like fiber with DNA binding capacity and the other one is a pilus structure that was thicker, much shorter and not able to bind DNA. Here we discuss how competence induced pili, either by pilus retraction or by a transient pilus‐related opening in the cell wall, may mediate DNA uptake in S. pneumoniae. 相似文献