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131.
Moberg P Nilsson S Ståhl A Eriksson AC Glaser E Mäler L 《Journal of molecular biology》2004,336(5):1129-1140
We have isolated, characterized and determined the three-dimensional NMR solution structure of the presequence of ATPsynthase F1beta subunit from Nicotiana plumbaginifolia. A general method for purification of presequences is presented. The method is based on overexpression of a mutant precursor containing a methionine residue introduced at the processing site, followed by CNBr-cleavage and purification of the presequence on a cation-exchange column. The F1beta presequence, 53 amino acid residues long, retained its native properties as evidenced by inhibition of in vitro mitochondrial import and processing at micromolar concentrations. CD spectroscopy revealed that the F1beta presequence formed an alpha-helical structure in membrane mimetic environments such as SDS and DPC micelles (approximately 50% alpha-helix), and in acidic phospholipid bicelles (approximately 60% alpha-helix). The NMR solution structure of the F1beta presequence in SDS micelles was determined on the basis of 518 distance and 21 torsion angle constraints. The structure was found to contain two helices, an N-terminal amphipathic alpha-helix (residues 4-15) and a C-terminal alpha-helix (residues 43-53), separated by a largely unstructured 27 residue long internal domain. The N-terminal amphipathic alpha-helix forms the putative Tom20 receptor binding site, whereas the C-terminal alpha-helix is located upstream of the mitochondrial processing peptidase cleavage site. 相似文献
132.
Cohen M Reichenstein M Everts-van der Wind A Heon-Lee J Shani M Lewin HA Weller JI Ron M Seroussi E 《Genomics》2004,84(2):374-383
133.
Lina Nilsson Annelie Pamrén Tohidul Islam Kristoffer Brännström Solmaz A. Golchin Nina Pettersson Irina Iakovleva Linda Sandblad Anna L. Gharibyan Anders Olofsson 《Journal of molecular biology》2018,430(17):2722-2733
The pathological Aβ aggregates associated with Alzheimer's disease follow a nucleation-dependent path of formation. A nucleus represents an oligomeric assembly of Aβ peptides that acts as a template for subsequent incorporation of monomers to form a fibrillar structure. Nuclei can form de novo or via surface-catalyzed secondary nucleation, and the combined rates of elongation and nucleation control the overall rate of fibril formation. Transthyretin (TTR) obstructs Aβ fibril formation in favor of alternative non-fibrillar assemblies, but the mechanism behind this activity is not fully understood. This study shows that TTR does not significantly disturb fibril elongation; rather, it effectively interferes with the formation of oligomeric nuclei. We demonstrate that this interference can be modulated by altering the relative contribution of elongation and nucleation, and we show how TTR's effects can range from being essentially ineffective to almost complete inhibition of fibril formation without changing the concentration of TTR or monomeric Aβ. 相似文献
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135.
Jenny A. Bosson Anders Blomberg Nikolai Stenfors Ragnberth Helleday Frank J. Kelly Annelie F. Behndig Ian S. Mudway 《PloS one》2013,8(12)
Background
Ozone concentrations are predicted to increase over the next 50 years due to global warming and the increased release of precursor chemicals. It is therefore urgent that good, reliable biomarkers are available to quantify the toxicity of this pollutant gas at the population level. Such a biomarker would need to be easily performed, reproducible, economically viable, and reflective of ongoing pathological processes occurring within the lung.Methodology
We examined whether blood neutrophilia occurred following a controlled ozone challenge and addressed whether this could serve as a biomarker for ozone-induced airway inflammation. Three separate groups of healthy subjects were exposed to ozone (0.2 ppm, 2h) and filtered air (FA) on two separate occasions. Peripheral blood samples were collected and bronchoscopy with biopsy sampling and lavages was performed at 1.5h post exposures in group 1 (n=13), at 6h in group 2 (n=15) and at 18h in group 3 (n=15). Total and differential cell counts were assessed in blood, bronchial tissue and airway lavages.Results
In peripheral blood, we observed fewer neutrophils 1.5h after ozone compared with the parallel air exposure (-1.1±1.0x109 cells/L, p<0.01), at 6h neutrophil numbers were increased compared to FA (+1.2±1.3x109 cells/L, p<0.01), and at 18h this response had fully attenuated. Ozone induced a peak in neutrophil numbers at 6h post exposure in all compartments examined, with a positive correlation between the response in blood and bronchial biopsies.Conclusions
These data demonstrate a systemic neutrophilia in healthy subjects following an acute ozone exposure, which mirrors the inflammatory response in the lung mucosa and lumen. This relationship suggests that blood neutrophilia could be used as a relatively simple functional biomarker for the effect of ozone on the lung. 相似文献136.
Allander T Andreasson K Gupta S Bjerkner A Bogdanovic G Persson MA Dalianis T Ramqvist T Andersson B 《Journal of virology》2007,81(8):4130-4136
We have previously reported on a system for large-scale molecular virus screening of clinical samples. As part of an effort to systematically search for unrecognized human pathogens, the technology was applied for virus screening of human respiratory tract samples. This resulted in the identification of a previously unknown polyomavirus provisionally named KI polyomavirus. The virus is phylogenetically related to other primate polyomaviruses in the early region of the genome but has very little homology (<30% amino acid identity) to known polyomaviruses in the late region. The virus was found by PCR in 6 (1%) of 637 nasopharyngeal aspirates and in 1 (0.5%) of 192 fecal samples but was not detected in sets of urine and blood samples. Since polyomaviruses have oncogenic potential and may produce severe disease in immunosuppressed individuals, continued searching for the virus in different medical contexts is important. This finding further illustrates how unbiased screening of respiratory tract samples can be used for the discovery of diverse virus types. 相似文献
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138.
Duperron S Bergin C Zielinski F Blazejak A Pernthaler A McKiness ZP DeChaine E Cavanaugh CM Dubilier N 《Environmental microbiology》2006,8(8):1441-1447
Bathymodiolus azoricus and Bathymodiolus puteoserpentis are symbiont-bearing mussels that dominate hydrothermal vent sites along the northern Mid-Atlantic Ridge (MAR). Both species live in symbiosis with two physiologically and phylogenetically distinct Gammaproteobacteria: a sulfur-oxidizing chemoautotroph and a methane-oxidizer. A detailed analysis of mussels collected from four MAR vent sites (Menez Gwen, Lucky Strike, Rainbow, and Logatchev) using comparative 16S rRNA sequence analysis and fluorescence in situ hybridization (FISH) showed that the two mussel species share highly similar to identical symbiont phylotypes. FISH observations of symbiont distribution and relative abundances showed no obvious differences between the two host species. In contrast, distinct differences in relative symbiont abundances were observed between mussels from different sites, indicating that vent chemistry may influence the relative abundance of thiotrophs and methanotrophs in these dual symbioses. 相似文献
139.
Hartwig W Lehmann Annelie Plentz Philipp von Landenberg Esther Müller-Godeffroy Susanne Modrow 《Arthritis research & therapy》2003,6(1):R1
Children with rheumatic oligoarthritis and polyarthritis frequently establish persistent parvovirus B19 infections that may
be associated with the production of antiphospholipid antibodies (anti-PL IgG). In this study we analysed the influence of
high-dose intravenous immunoglobulin (IVIG) therapy on virus load, on the level of anti-PL IgG and its potential capacity
to improve the patients' clinical status. Four juvenile patients with long-lasting polyarticular rheumatic diseases and persistent
parvovirus B19 infection, associated in three cases with the presence of antibodies against β2-glycoprotein I (anti-β2GPI IgG), were treated with two cycles of IVIG on five successive days (0.4 g/kg per day). Clinical parameters including scores
of disease activity, virus load and anti-PL IgG levels were determined before, during and after treatment. Two patients showed
a complete remission that has lasted 15 months. During that period they showed neither clinical nor laboratory signs of inflammation.
Viral DNA was not detectable in serum, and a decrease in anti-β2GPI IgG was observed. As assessed by the Childhood Health Assessment Questionnaire and the Health-related Quality of Life
Questionnaire for Children, both patients were no longer restricted in their activities of daily living and no impact on the
health-related quality of life was observed. In one patient the therapy failed: there was no improvement of symptoms and no
decrease in virus load or inflammatory parameters. In the fourth patient, clinical and laboratory parameters did not improve
despite a decrease in both viral load and anti-PL IgG. Our results show that the use of IVIG to treat parvovirus B19-triggered
polyarticular rheumatic disease of childhood might offer an opportunity to improve this disabling condition. 相似文献
140.