6,625 research outputs found

    Self-Maintained Coherent Oscillations in Dense Neutrino Gases

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    We present analytical solutions to the nonlinear equations describing the behavior of a gas of neutrinos with two flavors. Self-maintained coherent flavor oscillations are shown to occur when the gas density exceeds a critical value determined by the neutrino masses and the mean neutrino energy in the gas. Similar oscillations may have occurred in the early Universe.Comment: To appear in Physical Review D, July 199

    Discovery of Stable and Selective Antibody Mimetics from Combinatorial Libraries of Polyvalent, Loop-Functionalized Peptoid Nanosheets.

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    The ability of antibodies to bind a wide variety of analytes with high specificity and high affinity makes them ideal candidates for therapeutic and diagnostic applications. However, the poor stability and high production cost of antibodies have prompted exploration of a variety of synthetic materials capable of specific molecular recognition. Unfortunately, it remains a fundamental challenge to create a chemically diverse population of protein-like, folded synthetic nanostructures with defined molecular conformations in water. Here we report the synthesis and screening of combinatorial libraries of sequence-defined peptoid polymers engineered to fold into ordered, supramolecular nanosheets displaying a high spatial density of diverse, conformationally constrained peptoid loops on their surface. These polyvalent, loop-functionalized nanosheets were screened using a homogeneous Förster resonance energy transfer (FRET) assay for binding to a variety of protein targets. Peptoid sequences were identified that bound to the heptameric protein, anthrax protective antigen, with high avidity and selectivity. These nanosheets were shown to be resistant to proteolytic degradation, and the binding was shown to be dependent on the loop display density. This work demonstrates that key aspects of antibody structure and function-the creation of multivalent, combinatorial chemical diversity within a well-defined folded structure-can be realized with completely synthetic materials. This approach enables the rapid discovery of biomimetic affinity reagents that combine the durability of synthetic materials with the specificity of biomolecular materials

    Competing Demands for Time and Self-Care Behaviors, Processes of Care, and Intermediate Outcomes Among People With Diabetes: Translating Research Into Action for Diabetes (TRIAD)

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    ObjectiveTo determine whether competing demands for time affect diabetes self-care behaviors, processes of care, and intermediate outcomes.Research design and methodsWe used survey and medical record data from 5,478 participants in Translating Research Into Action for Diabetes (TRIAD) and hierarchical regression models to examine the cross-sectional associations between competing demands for time and diabetes outcomes, including self-management, processes of care, and intermediate health outcomes.ResultsFifty-two percent of participants reported no competing demands, 7% reported caregiving responsibilities only, 36% reported employment responsibilities only, and 6% reported both caregiving and employment responsibilities. For both women and men, employment responsibilities (with or without caregiving responsibilities) were associated with lower rates of diabetes self-care behaviors, worse processes of care, and, in men, worse HbA(1c).ConclusionsAccommodations for competing demands for time may promote self-management and improve the processes and outcomes of care for employed adults with diabetes

    Geometrical analysis of warp knit auxetic fabrics

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    Despite considerable interests that have been shown on the formation, properties and characteristics of auxetic knit structures there remains a dearth of information about the fundamental geometrical analytics of warp knit auxetic fabrics. This paper examines the geometrical model of auxetic warp knit structure and validates its characteristics with data obtained from experimental analysis of nine recently produced warp knit auxetic fabrics

    Bimodal Coherence in Dense Self-Interacting Neutrino Gases

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    Analytical solutions are obtained to the nonlinear equations describing neutrino oscillations when explicit neutrino-antineutrino asymmetries are present. Such a system occurs in the early Universe if neutrinos have a non-zero chemical potential. Solutions to the equations lead to a new type of coherent behavior governed by two modes. These bimodal solutions provide new insights into dense neutrino gases and into neutrino oscillations in the early Universe, thereby allowing one to surmise the flavor behavior of neutrinos with a non-zero chemical potential.Comment: 21 pages in Latex, 11 figures packaged in one Postscript file. Figures also obtainable as 20 gif files at http://www.sci.ccny.cuny.edu/~ssamuel/bimodalfigs.html Revision on 4/19/96 was to pack the figures more sensibly. This paper is to appear in a May issue of Phys. Rev.

    Impact of obesity on surgical outcomes following laminectomy for spinal metastases

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    To determine the effect of obesity (body mass index >30 kg/m(2)) on perioperative morbidity and mortality after surgical decompression of spinal metastases. Methods: The American College of Surgeons National Surgical Quality Improvement Program database is a large multicenter clinical registry that collects preoperative risk factors, intraoperative variables, and 30-day postoperative morbidity and mortality outcomes from hospitals nationwide. Current Procedural Terminology codes were used to query the database for adults who underwent decompression with laminectomy for treatment of metastatic spinal lesions between 2010 and 2014. Patients were separated into 2 cohorts based on the presence of absence of obesity. Univariate analysis and multivariate logistic regression analysis were used to analyze the effect of obesity on perioperative morbidity and mortality. Results: There was a significantly higher rate of venous thromboembolism (VTE; obese 6.6% vs nonobese 4.2%; P = .01) and pulmonary complications (obese 2.6% vs nonobese 2.2%; P = .046) in the obese group compared with the nonobese group. The nonobese group had prolonged hospitalization (obese 62.0% vs nonobese 69.0%; P = .001) and a higher incidence of blood transfusions (obese 26.8% vs nonobese 34.2%; P < .001). On multivariate analysis, obesity was found to be an independent risk factor for VTE (odds ratio = 1.75, confidence interval = 1.17-2.63, P = .007). Conclusions: Obese patients were predisposed to an elevated risk of VTE following laminectomy for spinal metastases. Early postoperative mobilization and a low threshold to evaluate for perioperative VTE are important in these patients in order to appropriately diagnose and treat these complications and minimize morbidity93254259sem informaçãosem informaçã
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