Intracoronary stents may potentially alleviate some of the problems associated with coronary angioplasty. Since the anatomy and physiology of swine coronary arteries closely resemble those of humans, ...the response to implantation of the Glanturco-Roubin, balloon-expandable, flexible stent was studied in this model. Additionally, the effect of aspirin, 1 mg/kg/day orally, on this response was evaluated. Eighteen Hanford minature swine underwent stenting of the left anterior descending coronary artery. Two died within 24 hours of stent implantation. The 16 survivors were put to death at 4 (n = 4), 11 (n = 4), 28 (n = 4), 56 (n = 3), and 180 (n = 1) days. Angiographically, reduction of stent lumen diameter of 0.1 to 1.3 mm was observed and was maximum at 11 days, with gradual improvement at subsequent time periods. Scanning electron microscopy, transmission electron microscopy, and light microscopy showed early disruption of subjacent endothelium, and adherence of platelets to exposed subendothelium and stent wires. Microthrombi were readily apparent. At 11 days, intimal thickening, made up predominantly of smooth muscle cells with abundant extracellular matrix, was observed and covered the stent wires. At 28 days, regression of intimal thickening was apparent and a confluent endothelium with flow-directed orientation was seen. At 56 and 180 days, the luminal surface was smooth; intimal thickening averaged 525 microns over the stent wires and 55 microns away from the wires. Findings in aspirin-treated animals were similar to results in those that did not receive aspirin. Thus in this swine model, stent implantation results in a time-dependent and self-limited vascular response.
From the vantage point of this practicing fire protection engineer, the most significant change in the last 10 years with regard to fire-related human behavior has been the considerable increase in ...the awareness and education of fire professionals on the topic. A few years later, the SFPE Engineering Guide to Human Behavior in Fires was published and became a vital source for guidance on occupant characteristics, human response to cues, decision-making and movement for direct implementation into the performance-based process.
Spatial, spectral and temporal variations in operating conditions are major contributors to the expected variability/uncertainty in system performance. The ratio of signal-to-noise ratio (SNR) based ...on climatological data to a standard atmosphere is the primary performance metric used, with results presented in the form of histograms and maps of worldwide LADAR performance variation. This metric is assessed at 2 wavelengths, 1.0642 microns and 1.557 microns, for a number of widely dispersed land and maritime locations worldwide over oblique and vertical air to surface paths in which anticipated clear air aerosols and location specific heavy rain and 150 m thick fog occur. Seasonal, boundary layer, and time of day variations for a range of relative humidity percentiles are also considered. In addition to realistic vertical profiles of molecular and aerosol extinction, air-to-ground cloud free line of sight (CFLOS) probabilities as a function of location for this geometry are computed. Observations from the current study strongly indicate that use of the standard atmosphere to predict performance will produce overly optimistic, in many cases extremely so, estimates of expected performance. Locally heavy rain, when present, severely limits LADAR system performance at these wavelengths. Some operational capability exists for vertical looks through fog.
Published in Journal of Applied Remote Sensing, v3 article 033521, 31 March 2009.
The Sociology of Katrina Brunsma, David L; Overfelt, David; Picou, Steven J ...
2010, 2010-09-16
eBook
The second edition of The Sociology of Katrina again brings together the nation's top sociological researchers in an effort to catalogue and deepen our understanding of the modern catastrophe of ...Hurricane Katrina. The new edition has been updated and revised throughout, including data about recovery efforts and conditions, and discussions of social issues like education, health care, crime, and the economy. This edition features a new chapter focused on the Katrina experience for people in the primary impact area, or "ground zero," five years after the storm.
Ephs regulate growth cone repulsion, a process controlled by the actin cytoskeleton. The guanine nucleotide exchange factor (GEF) ephexin1 interacts with EphA4 and has been suggested to mediate the ...effect of EphA on the activity of Rho GTPases, key regulators of the cytoskeleton and axon guidance. Using cultured
ephexin1
−/−
mouse neurons and RNA interference in the chick, we report that ephexin1 is required for normal axon outgrowth and ephrin-dependent axon repulsion. Ephexin1 becomes tyrosine phosphorylated in response to EphA signaling in neurons, and this phosphorylation event is required for growth cone collapse. Tyrosine phosphorylation of ephexin1 enhances ephexin1’s GEF activity toward RhoA while not altering its activity toward Rac1 or Cdc42, thus changing the balance of GTPase activities. These findings reveal that ephexin1 plays a role in axon guidance and is regulated by a switch mechanism that is specifically tailored to control Eph-mediated growth cone collapse.
Ocular light exposure has important influences on human health and well-being through modulation of circadian rhythms and sleep, as well as neuroendocrine and cognitive functions. Prevailing patterns ...of light exposure do not optimally engage these actions for many individuals, but advances in our understanding of the underpinning mechanisms and emerging lighting technologies now present opportunities to adjust lighting to promote optimal physical and mental health and performance. A newly developed, international standard provides a SI-compliant way of quantifying the influence of light on the intrinsically photosensitive, melanopsin-expressing, retinal neurons that mediate these effects. The present report provides recommendations for lighting, based on an expert scientific consensus and expressed in an easily measured quantity (melanopic equivalent daylight illuminance (melaponic EDI)) defined within this standard. The recommendations are supported by detailed analysis of the sensitivity of human circadian, neuroendocrine, and alerting responses to ocular light and provide a straightforward framework to inform lighting design and practice.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The primary aim of the Million Hearts initiative is to prevent 1 million cardiovascular events over 5 years. Concordant with the Million Hearts' focus on achieving more than 70% performance in the ..."ABCS" of aspirin for those at risk, blood pressure control, cholesterol management, and smoking cessation, we outline the cardiovascular events that would be prevented and a road map to achieve more than 70% participation in cardiac rehabilitation (CR)/secondary prevention programs by the year 2022. Cardiac rehabilitation is a class Ia recommendation of the American Heart Association and the American College of Cardiology after myocardial infarction or coronary revascularization, promotes the ABCS along with lifestyle counseling and exercise, and is associated with decreased total mortality, cardiac mortality, and rehospitalizations. However, current participation rates for CR in the United States generally range from only 20% to 30%. This road map focuses on interventions, such as electronic medical record-based prompts and staffing liaisons that increase referrals of appropriate patients to CR, increase enrollment of appropriate individuals into CR, and increase adherence to longer-term CR. We also calculate that increasing CR participation from 20% to 70% would save 25,000 lives and prevent 180,000 hospitalizations annually in the United States.
Of all cells implicated in the pathology of rheumatoid arthritis (RA), neutrophils possess the greatest cytotoxic potential, owing to their ability to release degradative enzymes and reactive oxygen ...species. Neutrophils also contribute to the cytokine and chemokine cascades that accompany inflammation, and regulate immune responses via cell-cell interactions. Emerging evidence suggests that neutrophils also have a previously unrecognised role in autoimmune diseases: neutrophils can release neutrophil extracellular traps (NETs) containing chromatin associated with granule enzymes, which not only kill extracellular microorganisms but also provide a source of autoantigens. For example, citrullinated proteins that can act as neoepitopes in loss of immune tolerance are generated by peptidylarginine deiminases, which replace arginine with citrulline residues, within neutrophils. Indeed, antibodies to citrullinated proteins can be detected before the onset of symptoms in patients with RA, and are predictive of erosive disease. Neutrophils from patients with RA have an increased tendency to form NETs containing citrullinated proteins, and sera from such patients contain autoantibodies that recognize these proteins. Thus, in addition to their cytotoxic and immunoregulatory role in RA, neutrophils may be a source of the autoantigens that drive the autoimmune processes underlying this disease.
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