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991.
Deep inspirations (DIs) have a dilatory effect on airway smooth muscle (ASM) that helps to prevent or reduce more severe bronchoconstriction in healthy individuals. However, this bronchodilation appears to fail in some asthmatic patients or under certain conditions, and the reason is unclear. Additionally, quantitative effects of the frequency and magnitude of DIs on bronchodilation are not well understood. In the present study, we used a computational model of bronchoconstriction to study the effects of DI volumes, time intervals between intermittent DIs, relative speed of ASM constriction, and ASM activation on bronchoconstriction and the emergence of ventilation defects (VDefs). Our results showed a synergistic effect between the volume of DIs and the time intervals between them on bronchoconstriction and VDefs. There was a domain of conditions with sufficiently large volumes of DIs and short time intervals between them to prevent VDefs. Among conditions without VDefs, larger volumes of DIs resulted in greater airway dilation. Similarly, the time interval between DIs, during which the activated ASM re-constricts, affected the amplitude of periodic changes in airway radii. Both the relative speed of ASM constriction and ASM activation affected what volume of DIs and what time interval between them could prevent the emergence of VDefs. In conclusion, quantitative characteristics of DIs, such as their volume and time interval between them, affect bronchoconstriction and may contribute to difficulties in asthma. Better understanding of the quantitative aspects of DIs may result in novel or improved therapeutic approaches. 相似文献
992.
993.
994.
Ulrich Winkler 《Molecular & general genetics : MGG》1965,97(1):75-78
Summary In phageKappa which has been irradiated extracellularly with different UV-doses about 75% of the lethal damage can be nullified by adsorption to stationary wildtype-cells ofSerratiaHy and maximum photoreactivation. Assuming that the two hits necessary for a UV-inducedc-premutation are photoreactivated at once the photoreactivable sector among the premutations is about 71%; this would mean that the photoreactivating enzyme inSerratiaHy can not distinguish between premutations and lethal lesions. However, if these two hits are photoreactivated separately the photoreactivable sector would be only 45%. At present one can not decide between these two possiblities.
Mit 1 Textabbildung 相似文献
Mit 1 Textabbildung 相似文献
995.
Summary A system of four phages is described which permits the differentiation of staphylococci in phage group II into about ten distinct
patterns which are dependent on lysogenicity (see table 5). All phages are propagated on one propagating strain. Weak reactions
are rare. The new patterns II A, II B ... to II K correlated reasonably with the patterns of theWilliams andRippon system. 相似文献
996.
Moritz Winkler 《Plant Systematics and Evolution》1874,24(11):345-351
Ohne Zusammenfassung 相似文献
997.
Summary Phage T6 and T7 did not reproduce in mutants ofE. coli auxotrophic for the amino acids methionine, leucine, serine, proline, histidine, tyrosine, phenylalanine and tryptophane
unless these amino acids were present in the medium. Very small amounts of these auxotrophic factors (0.01 γ/ml) are able
to support phage multiplication. Much care has to be taken to avoid impurities in the medium and to deplete the endogenous
reserves of the host cells. 相似文献
998.
Wilibald Winkler 《Plant Systematics and Evolution》1878,28(1):7-8
Ohne Zusammenfassung 相似文献
999.
Moriz Winkler 《Plant Systematics and Evolution》1866,16(1):13-21
Ohne Zusammenfassung 相似文献
1000.
The ADP/ATP carrier from yeast (AAC-2) is uniquely suited for the assignment of the binding center by photoaffinity labeling 总被引:3,自引:0,他引:3
The ADP/ATP carrier from yeast was photoaffinity-labeled in mitochondria with 2-azido-[alpha-32P]ATP in a binding-center-specific, i.e. carboxyatractylate-sensitive, manner. After isolation, fragmentation possibilities unique for the yeast AAC-2 could be exploited to assign the insertion to a narrow range of the sequence. The CNBr fragment 115-210 contained all the incorporated label which corresponds to the second domain within the triple-domain primary structure of the AAC. With hydroxylamine cleavage directed to the Asn 171-Gly 172 site, all the label was found in the C-terminal 16 kDa fragment. Thus the 2-azido-ATP incorporation is clearly delimited to the 172-210 segment. 8-Azido-[alpha-32P]ATP could be site-specifically incorporated only in isolated AAC since it has a much lower affinity for AAC than 2-azido-ATP. The label was also exclusively found in the 172-210 region. With both forms no incorporation into the C-terminal region was found, as claimed for bovine AAC. The labeled segment contains Lys 179 and 182 which are homologous to bovine Lys 162 and 165 and which have been proposed to be in the translocation path. 相似文献