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Lorch JM Meteyer CU Behr MJ Boyles JG Cryan PM Hicks AC Ballmann AE Coleman JT Redell DN Reeder DM Blehert DS 《Nature》2011,480(7377):376-378
White-nose syndrome (WNS) has caused recent catastrophic declines among multiple species of bats in eastern North America. The disease's name derives from a visually apparent white growth of the newly discovered fungus Geomyces destructans on the skin (including the muzzle) of hibernating bats. Colonization of skin by this fungus is associated with characteristic cutaneous lesions that are the only consistent pathological finding related to WNS. However, the role of G. destructans in WNS remains controversial because evidence to implicate the fungus as the primary cause of this disease is lacking. The debate is fuelled, in part, by the assumption that fungal infections in mammals are most commonly associated with immune system dysfunction. Additionally, the recent discovery that G. destructans commonly colonizes the skin of bats of Europe, where no unusual bat mortality events have been reported, has generated further speculation that the fungus is an opportunistic pathogen and that other unidentified factors are the primary cause of WNS. Here we demonstrate that exposure of healthy little brown bats (Myotis lucifugus) to pure cultures of G. destructans causes WNS. Live G. destructans was subsequently cultured from diseased bats, successfully fulfilling established criteria for the determination of G. destructans as a primary pathogen. We also confirmed that WNS can be transmitted from infected bats to healthy bats through direct contact. Our results provide the first direct evidence that G. destructans is the causal agent of WNS and that the recent emergence of WNS in North America may represent translocation of the fungus to a region with a naive population of animals. Demonstration of causality is an instrumental step in elucidating the pathogenesis and epidemiology of WNS and in guiding management actions to preserve bat populations against the novel threat posed by this devastating infectious disease. 相似文献
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F. C. Camargo A. F. Lehner J. D. Harkins C. G. Hughes W. Karpiesiuk J. Boyles W. E. Woods T. Tobin 《Chromatographia》2004,60(7-8):371-378
Trimetoquinol (TMQ) (1-(3,4,5-trimethoxybenzyl)-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline, m.w. 345) is the prototype tetrahydroisoquinoline pharmaceutical. TMQ is marketed as a bronchodilator in human medicine; in horse racing, TMQ is listed as an Association of Racing Commissioners International (ARCI) class 3 foreign substance. As such, TMQ is considered to have the potential to affect racing performance in horses, and a validated qualitative confirmatory method is required to regulate its use in racing. We selected 8 g kg–1 of TMQ IV as a safe and effective dose for studies on its metabolism and analytical detection in horses. We developed a solid phase extraction method for recovery of TMQ and its metabolites from equine urine, identified suitable high performance liquid chromatographic conditions for these substances and our internal standard, papaverine, and developed a highly sensitive ESI(+)-LC-MS-MS method (estimated LOD, 100 pg mL–1) for TMQ and its major metabolites in equine urine. Multiple Reaction Monitoring (MRM) analysis of unhydrolyzed post-administration urine showed small amounts of unchanged TMQ, along with glucuronide, methylated, and sulfated metabolites, with glucuronide metabolites predominating. Following glucuronidase hydrolysis, recovered parent TMQ peaked at relatively high concentrations (>300 ng mL–1) within 1 h of administration and thereafter declined. The methylated metabolites of TMQ peaked later and at comparable total concentrations, and thereafter declined more slowly. These data suggest that glucuronide hydrolysis of post-administration urine samples will allow recovery of readily identifiable quantities of parent TMQ. These findings, combined with the highly sensitive LC-MS-MS detection of parent TMQ described herein suggest that glucuronide hydrolysis of post-administration urine, followed by LC-MS-MS or other analysis, will allow effective regulatory control of this agent in racing horses.Published as # 351 from the Equine Pharmacology, Therapeutics and Toxicology Program at the Maxwell H. Gluck Equine Research Center and Department of Veterinary Science, University of Kentucky. Published as Kentucky Agricultural Experiment Station Article # 04-14-048 with the approval of the Dean and Director, College of Agriculture and the Kentucky Agricultural Experimental Station.Revised: 8 June and 12 July 2004 相似文献
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Glass fillers were suface modified by direct formation of a silicon-carbon non-hydrolyzable linkage between glass and coupling agent. The grafted silane monolayer was evaluated by infrared spectroscopy. Samples were subjected to hydrolytic conditions to compare their surface treatment stability with traditional surface treatment hydrolytic stability. Composite specimens were fabricated and their mechanical properties were compared with traditional aminopropylsilane coupling agent treatment. 相似文献
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J. Michael Robinson Masood Ahmed Nicky J. Alaniz Timothy R. Boyles Chris D. Brasher Kimberly A. Floyd Preston L. Holland Laura D. Maruffo Terry L. Mcmahan Stan Middleton Kevin D. O'Hara Marcia J. Pack Brandon D. Reynolds Romelia R. Rodriquez Dennis E. Sawyer Elena Sharp Sharai L. Simpson Clint L. Vanlandingham Rebecca S. Velasquez Brian M. Welch C. David Wright 《Journal of heterocyclic chemistry》1998,35(1):65-69
Alternative complimentary syntheses of penta-substituted pyridine rings with full regiochemical control of substituents were studied as a method for the synthesis of Streptonigrin ( 1 ). Various α-substituted acetophenones 2 were reacted with enones 3 in acetic acid/ammonium acetate and air to afford penta-substituted pyridines 4 . α-Substituents that could provide a source of exocyclic nitrogen at position 3 of these Steptonigrin ring-C models proved to be the limiting factor. However, an inverse “3+2+1” cyclocondensation of α-cyanochalcone 5c with 2-furyl ethyl ketone ( 6b ) afforded the desired model 6-(2-furyl)-5-methyl2,4-diphenyl-3-pyridinecarbonitrile ( 4g ) in 75% yield. 相似文献
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James G. Boyles Sidney Toby 《Journal of polymer science. Part A, Polymer chemistry》1967,5(7):1705-1716
The polymerization of gaseous monomeric formaldehyde has been studied. The effects of the following variables have been investigated: temperature, initial monomer pressure, surface-to-volume ratio of reaction vessel, thickness of polymer deposit, and partial pressure of added oxygen. A three-step mechanism is proposed which successfully accounts for the results of experiments in which monomer is allowed to deposit on the bare wall of the reaction vessel. When a sufficient amount of polymer has been laid down, the termination reaction becomes negligible and a limiting two-step mechanism holds. The present results combined with literature values from work done on the depolymerization reaction give the activation energy of the propagation and termination reactions to be 14.2 ± 0.6 and 7.8 ± 0.9 kcal./mole, respectively. Although the reaction is heterogeneous, the activation energies are independent of surface-to-volume ratios within the experimental error. The nature of the polymer active sites is considered and these are thought to be hydroxyl groups. The results of work done with added oxygen show a small inhibitory effect. 相似文献
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A. F. Lehner C. G. Hughes W. Karpiesiuk F. C. Camargo J. D. Harkins W. E. Woods J. Bosken J. Boyles A. Troppmann T. Tobin 《Chromatographia》2004,59(1):S79-S84
Salmeterol is a β2-adrenergic agonist and an Association of Racing Commissioners International (ARCI) class 3 drug. Trade names of its xinafoate salt are Arial (Dompé), Salmetedur (Menarini), and Serevent (Glaxo). Salmeterol is routinely used to increase ease of breathing in race horses during their training. Due to its bronchodilating and central nervous system stimulant properties, its administration to a horse just prior to race time has the potential to affect the horse’s performance, therefore a reliable method of analysis for this compound is necessary. This paper describes a method for the identification and quantitation of salmeterol in equine urine using liquid-liquid extraction followed by liquid chromatography and tandem mass spectrometry (LC-MS-MS). Urine salmeterol concentrations peaked at about 2 h post-dose following administration of 500 ug both intravenously and intratracheally at concentrations of 14 ng mL?1 and 4 ng mL?1, respectively. Serum concentrations at 30 min were below the minimum level of quantitation. 相似文献