Conditions for the first palladium-catalyzed chemoselective protodecarboxylation of polyenoic acids to give the desired polyenes in good yields are presented. The reactions proceed under mild conditions using either a Pd(0) or Pd(II) catalyst and tolerate a variety of aryl and aliphatic substitutions. Unique aspects of the reaction include the requirement of phosphines, water, and a polyene adjacent to the carboxylic acid.
View Article and Find Full Text PDFAn active sonar system is used to image wide areas of the continental shelf environment by long-range echo sounding at low frequency. The bistatic system, deployed in the STRATAFORM area south of Long Island in April-May of 2001, imaged a large number of prominent clutter events over ranges spanning tens of kilometers in near real time. Roughly 3000 waveforms were transmitted into the water column.
View Article and Find Full Text PDFJ Neurosci Nurs
October 1999
Aggressive physical behaviour (APB) is common in persons with dementia and often leads to negative consequences such as use of restraints and staff member burnout. For the past several years, a group of nurse researchers has collaborated to develop a model that views dementia behaviors as need-driven but dementia-compromised. The model posits that background variables of the demented person interact with proximal (or current situational) variables to produce APB.
View Article and Find Full Text PDFBackground: Prejunctional receptors for angiotensin II (A-II) and norepinephrine (NE) have been reported to facilitate NE release. If operative in patients with congestive heart failure (CHF), such receptors could participate in positive feedback cycles amplifying sympathoactivation.
Methods And Results: A-II and isoproterenol (ISO) would increase regional NE spillover via facilitation of presynaptic release of NE in the forearm circulation of patients with chronic stable CHF.
Background: Progressive ventricular remodeling after myocardial damage is associated with a poor prognosis. Optimal prevention of the histopathological processes involved in remodeling requires a more complete understanding of the mechanisms involved in initiating and maintaining these structural changes. Since the sympathetic nervous system and the renin-angiotensin system may be involved in the remodeling process, the structural effects of pharmacological inhibitors have been evaluated in a canine model of localized myocardial injury resulting from transmyocardial DC shock.
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