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Interconnected Self-Propagating Photopolymer Waveguides: An Alternative to Stereolithography for Rapid Formation of Lattice-Based Open-Cellular Materials
Recently, a new technique has been developed to create unique open-cellular materials with
micro-scale truss, or lattice features ranging from tens to hundreds of microns. These materials
are formed from a three-dimensional, interconnected array of self-propagating photopolymer
waveguides. By utilizing this self-propagating effect, three-dimensional open-cellular polymer
materials can be formed in seconds. In addition, intrinsic to the process is the ability to control
specific micro-lattice parameters which ultimately affect the bulk material properties. Unlike
stereolithography, this new fabrication technique is rapid (~ minutes to form an entire part) and
relies on a single two-dimensional exposure surface to form three-dimensional structures
(thickness > 25 mm possible). This combination of speed and planar scalability opens the
possibility for large-scale mass manufacturing. The utility of these new materials range from
lightweight energy absorbing structures to thermal management materials to bio-scaffolds.Mechanical Engineerin
Homology of Distributive Lattices
We outline the theory of sets with distributive operations: multishelves and
multispindles, with examples provided by semi-lattices, lattices and skew
lattices. For every such a structure we define multi-term distributive homology
and show some of its properties. The main result is a complete formula for the
homology of a finite distributive lattice. We also indicate the answer for
unital spindles and conjecture the general formula for semi-lattices and some
skew lattices. Then we propose a generalization of a lattice as a set with a
number of idempotent operations satisfying the absorption law.Comment: 30 pages, 3 tables, 3 figure
Shear-Mediated Dilation of the Internal Carotid Artery Occurs Independent of Hypercapnia.
Evidence for shear stress as a regulator of carotid artery dilation in response to increased arterial carbon dioxide was recently demonstrated in humans during sustained elevations in CO2 (hypercapnia); however, the relative contributions of CO2 and shear stress to this response remains unclear. We examined the hypothesis that, following a 30-second transient increase in arterial CO2 tension and consequent increase in internal carotid artery shear stress, internal carotid artery diameter would increase, indicating shear-mediated dilation, in the absence of concurrent hypercapnia. In 27 healthy participants the partial pressures of end-tidal O2 and CO2, ventilation (pneumotachography), blood pressure (finger-photoplethysmography), heart-rate (electrocardiogram), internal carotid artery flow, diameter and shear stress (high resolution duplex ultrasound) and middle cerebral artery blood velocity (transcranial Doppler) were measured during 4-minute steady state and transient 30-second hypercapnic tests (both +9mmHg CO2). Internal carotid artery dilation was lower in the transient, compared to the steady state hypercapnia (3.3±1.9% vs. 5.3±2.9%, respectively; P<0.03). Increases in internal carotid artery shear stress preceded increases in diameter in both the transient (time: 16.8±13.2s vs. 59.4±60.3s; P<0.01) and steady state (time: 18.2±14.2s vs. 110.3±79.6s; P<0.01) tests. Internal carotid artery dilation was positively correlated with shear rate area under the curve in the transient (r(2)=0.44; P<0.01), but not steady state (r(2)=0.02; P=0.53) trial. Collectively, these results suggest that hypercapnia induces shear-mediated dilation of the internal carotid artery in humans. This study further promotes the application and development of hypercapnia as a clinical strategy for the assessment of cerebrovascular vasodilatory function and health in humans
A Possibility of large electro-weak penguin contribution in B -> K pi modes
We discuss about a possibility of large electro-weak penguin contribution in
B -> K pi from recent experimental data. The several relations among the
branching ratios which realize when the contributions from tree type and
electro-weak penguin are small compared with the gluon penguin and can be
treated as the expansion parameters do not satisfy the data. The difference
comes from the r^2 terms which is the square of the ratio with the gluon
penguin and the main contribution comes from electro-weak penguin. We find that
the contribution from electro-weak penguin may be large to explain the
experimental data. If the magnitude estimated from experiment is quite large
compared with the theoretical estimation, then it may be including some new
physics effects.Comment: 11 pages, 1 figure, Typos correcte
Common Data Elements for National Institute of Mental Health–Funded Translational Early Psychosis Research
The National Institutes of Health has established the PhenX Toolkit as a web-based resource containing consensus measures freely available to the research community. The National Institute of Mental Health (NIMH) has introduced the Mental Health Research Core Collection as part of the PhenX Toolkit and recently convened the PhenX Early Psychosis Working Group to generate the PhenX Early Psychosis Specialty Collection. The Working Group consisted of two complementary panels for clinical and translational research. We review the process, deliberations, and products of the translational research panel. The Early Psychosis Specialty Collection rationale for measure selection as well as additional information and protocols for obtaining each measure are available on the PhenX website (https://www.phenxtoolkit.org). The NIMH strongly encourages investigators to use instruments from the PhenX Mental Health Research Collections in NIMH-funded studies and discourages use of alternative measures to collect similar data without justification. We also discuss some of the potential advances that can be achieved by collecting common data elements across large-scale longitudinal studies of early psychosis
Worldwide experience with a totally subcutaneous implantable defibrillator: Early results from the EFFORTLESS S-ICD registry
Aims The totally subcutaneous implantable-defibrillator (S-ICD) is a new alternative to the conventional transveno
Performance of the subcutaneous implantable cardioverter-defibrillator in patients with a primary prevention indication with and without a reduced ejection fraction versus patients with a secondary prevention indication
Background: The subcutaneous implantable defibrillator (S-ICD) provides an alternative to the transvenous ICD for the prevention of sudden cardiac death, but has not been well studied in the most commonly treated transvenous ICD patient population, namely, primary prevention (PP) patients with left ventricular dysfunction. Objective: The analyses in the present study were designed to compar
A proof of the uniform boundedness of solutions to the wave equation on slowly rotating Kerr backgrounds
We consider Kerr spacetimes with parameters a and M such that |a|<< M,
Kerr-Newman spacetimes with parameters |Q|<< M, |a|<< M, and more generally,
stationary axisymmetric black hole exterior spacetimes which are sufficiently
close to a Schwarzschild metric with parameter M>0, with appropriate geometric
assumptions on the plane spanned by the Killing fields. We show uniform
boundedness on the exterior for sufficiently regular solutions to the scalar
homogeneous wave equation. In particular, the bound holds up to and including
the event horizon. No unphysical restrictions are imposed on the behaviour of
the solution near the bifurcation surface of the event horizon. The pointwise
estimate derives in fact from the uniform boundedness of a positive definite
energy flux. Note that in view of the very general assumptions, the
separability properties of the wave equation on the Kerr background are not
used.Comment: 71 pages, 3 figure
Impact of sympathetic nervous system activity on post-exercise flow-mediated dilatation in humans
Transient reduction in vascular function following systemic large muscle group exercise has previously been reported in humans. The mechanisms responsible are currently unknown. We hypothesised that sympathetic nervous system activation, induced by cycle ergometer exercise, would contribute to post-exercise reductions in flow-mediated dilatation (FMD). Ten healthy male subjects (28 ± 5 years) undertook two 30 min sessions of cycle exercise at 75% HRmax. Prior to exercise, individuals ingested either a placebo or an α1-adrenoreceptor blocker (prazosin; 0.05 mg kg−1). Central haemodynamics, brachial artery shear rate (SR) and blood flow profiles were assessed throughout each exercise bout and in response to brachial artery FMD, measured prior to, immediately after and 60 min after exercise. Cycle exercise increased both mean and antegrade SR (P < 0.001) with retrograde SR also elevated under both conditions (P < 0.001). Pre-exercise FMD was similar on both occasions, and was significantly reduced (27%) immediately following exercise in the placebo condition (t-test, P = 0.03). In contrast, FMD increased (37%) immediately following exercise in the prazosin condition (t-test, P = 0.004, interaction effect P = 0.01). Post-exercise FMD remained different between conditions after correction for baseline diameters preceding cuff deflation and also post-deflation SR. No differences in FMD or other variables were evident 60 min following recovery. Our results indicate that sympathetic vasoconstriction competes with endothelium-dependent dilator activity to determine post-exercise arterial function. These findings have implications for understanding the chronic impacts of interventions, such as exercise training, which affect both sympathetic activity and arterial shear stress
Knowledge-based energy functions for computational studies of proteins
This chapter discusses theoretical framework and methods for developing
knowledge-based potential functions essential for protein structure prediction,
protein-protein interaction, and protein sequence design. We discuss in some
details about the Miyazawa-Jernigan contact statistical potential,
distance-dependent statistical potentials, as well as geometric statistical
potentials. We also describe a geometric model for developing both linear and
non-linear potential functions by optimization. Applications of knowledge-based
potential functions in protein-decoy discrimination, in protein-protein
interactions, and in protein design are then described. Several issues of
knowledge-based potential functions are finally discussed.Comment: 57 pages, 6 figures. To be published in a book by Springe
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