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排序方式: 共有361条查询结果,搜索用时 15 毫秒
211.
212.
Mechanical failure modes leading to cracks or breeches in proton exchange membrane fuel cells are driven by mechanical forces associated with swelling from water uptake and shrinkage from dehumidifi-cation. To determine the magnitude of compressive mechanical stress imposed by water swelling in a proton exchange fuel-cell membrane, the osmotic pressure of water in a perfluorosulfonic acid ionomer (Nafion? N 117) membrane was measured using a hydrostatic piston-cylinder device with an in-situ hydrophilic frit. Experiments indicate that hydrostatic stresses greater than 103.5 MPa are created in a membrane when swollen with water at 23℃ suggesting that pressure from water swelling can distort Nafion N 117-based structures as the osmotic pressure is of the same order of magnitude as the flow stress of Nafion N 117. 相似文献
213.
214.
With the rapid development of mobile communication equipment, the significant role of social media platforms is realized in social media marketing. To determine the effect of instant messaging social media platform characteristics on consumers’ purchase intention, we collected We Chat user data and designed an empirical model based on the technology acceptance theory. Analysis of 388 qualified surveys revealed significant positive effects of instant messaging social media platform characteristic... 相似文献
215.
Davis EE Zhang Q Liu Q Diplas BH Davey LM Hartley J Stoetzel C Szymanska K Ramaswami G Logan CV Muzny DM Young AC Wheeler DA Cruz P Morgan M Lewis LR Cherukuri P Maskeri B Hansen NF Mullikin JC Blakesley RW Bouffard GG;NISC Comparative Sequencing Program Gyapay G Rieger S Tönshoff B Kern I Soliman NA Neuhaus TJ Swoboda KJ Kayserili H Gallagher TE Lewis RA Bergmann C Otto EA Saunier S Scambler PJ Beales PL Gleeson JG Maher ER Attié-Bitach T Dollfus H Johnson CA Green ED Gibbs RA Hildebrandt F 《Nature genetics》2011,43(3):189-196
Ciliary dysfunction leads to a broad range of overlapping phenotypes, collectively termed ciliopathies. This grouping is underscored by genetic overlap, where causal genes can also contribute modifier alleles to clinically distinct disorders. Here we show that mutations in TTC21B, which encodes the retrograde intraflagellar transport protein IFT139, cause both isolated nephronophthisis and syndromic Jeune asphyxiating thoracic dystrophy. Moreover, although resequencing of TTC21B in a large, clinically diverse ciliopathy cohort and matched controls showed a similar frequency of rare changes, in vivo and in vitro evaluations showed a significant enrichment of pathogenic alleles in cases (P < 0.003), suggesting that TTC21B contributes pathogenic alleles to ~5% of ciliopathy cases. Our data illustrate how genetic lesions can be both causally associated with diverse ciliopathies and interact in trans with other disease-causing genes and highlight how saturated resequencing followed by functional analysis of all variants informs the genetic architecture of inherited disorders. 相似文献
216.
Alison Adam 《Annals of science》2013,70(3):241-243
We study here the reception by their contemporaries of Antoine de Villon's and étienne de Clave's anti-Aristotelian, almost materialistic and atomistic theses, which they intended to support publicly in Paris in 1624, using (al)chemical experiments to this purpose. After surveying the intellectual context which could have then nourished an atomism based upon (al)chemical experiments, we go on to show how these theses, far from having been perceived as prominently atomistic, were condemned by the contemporaries above all because of the theological implications of their provocative anti-Aristotelism. Alchemy itself was not directly implicated in the case of the theses. On the contrary, the theses were perceived as an alien body within the alchemical tradition. 相似文献
217.
A recurrent 15q13.3 microdeletion syndrome associated with mental retardation and seizures 总被引:1,自引:0,他引:1
Sharp AJ Mefford HC Li K Baker C Skinner C Stevenson RE Schroer RJ Novara F De Gregori M Ciccone R Broomer A Casuga I Wang Y Xiao C Barbacioru C Gimelli G Bernardina BD Torniero C Giorda R Regan R Murday V Mansour S Fichera M Castiglia L Failla P Ventura M Jiang Z Cooper GM Knight SJ Romano C Zuffardi O Chen C Schwartz CE Eichler EE 《Nature genetics》2008,40(3):322-328
We report a recurrent microdeletion syndrome causing mental retardation, epilepsy and variable facial and digital dysmorphisms. We describe nine affected individuals, including six probands: two with de novo deletions, two who inherited the deletion from an affected parent and two with unknown inheritance. The proximal breakpoint of the largest deletion is contiguous with breakpoint 3 (BP3) of the Prader-Willi and Angelman syndrome region, extending 3.95 Mb distally to BP5. A smaller 1.5-Mb deletion has a proximal breakpoint within the larger deletion (BP4) and shares the same distal BP5. This recurrent 1.5-Mb deletion contains six genes, including a candidate gene for epilepsy (CHRNA7) that is probably responsible for the observed seizure phenotype. The BP4-BP5 region undergoes frequent inversion, suggesting a possible link between this inversion polymorphism and recurrent deletion. The frequency of these microdeletions in mental retardation cases is approximately 0.3% (6/2,082 tested), a prevalence comparable to that of Williams, Angelman and Prader-Willi syndromes. 相似文献
218.
FCGR3B copy number variation is associated with susceptibility to systemic, but not organ-specific, autoimmunity 总被引:13,自引:0,他引:13
Fanciulli M Norsworthy PJ Petretto E Dong R Harper L Kamesh L Heward JM Gough SC de Smith A Blakemore AI Froguel P Owen CJ Pearce SH Teixeira L Guillevin L Graham DS Pusey CD Cook HT Vyse TJ Aitman TJ 《Nature genetics》2007,39(6):721-723
Naturally occurring variation in gene copy number is increasingly recognized as a heritable source of susceptibility to genetically complex diseases. Here we report strong association between FCGR3B copy number and risk of systemic lupus erythematosus (P = 2.7 x 10(-8)), microscopic polyangiitis (P = 2.9 x 10(-4)) and Wegener's granulomatosis in two independent cohorts from the UK (P = 3 x 10(-3)) and France (P = 1.1 x 10(-4)). We did not observe this association in the organ-specific Graves' disease or Addison's disease. Our findings suggest that low FCGR3B copy number, and in particular complete FCGR3B deficiency, has a key role in the development of systemic autoimmunity. 相似文献
219.
Tarpey PS Raymond FL Nguyen LS Rodriguez J Hackett A Vandeleur L Smith R Shoubridge C Edkins S Stevens C O'Meara S Tofts C Barthorpe S Buck G Cole J Halliday K Hills K Jones D Mironenko T Perry J Varian J West S Widaa S Teague J Dicks E Butler A Menzies A Richardson D Jenkinson A Shepherd R Raine K Moon J Luo Y Parnau J Bhat SS Gardner A Corbett M Brooks D Thomas P Parkinson-Lawrence E Porteous ME Warner JP Sanderson T Pearson P Simensen RJ Skinner C Hoganson G Superneau D Wooster R Bobrow M 《Nature genetics》2007,39(9):1127-1133
220.
Nucleotide sequence of the yeast plasmid 总被引:86,自引:0,他引:86
The nucleotide sequence of the yeast DNA plasmid (2 mu circle) from Saccharomyces cerevisiae strain A364A D5 has been determined. The plasmid contains 6,318 base pairs, including two identical inverted repeats of 599 base pairs. Possible functions are suggested, and attributes of an improved vector for cloning foreign DNAs in yeast are discussed. 相似文献