2,306 research outputs found
Comments on "Vortex Glass and Lattice Melting Transitions in a YNi_2B_2C Single Crystal"
Recently, Mun et.al. (Phys. Rev. Lett., 76, 2790 (1996)) have published their
results on single crystal YNi_2B_2C, claiming that their experimental
observations can be explained in terms of formation of Vortex Glass and Lattice
melting. Our experiments, carried out on samples obtained from the SAME source,
reveal a much richer phase diagram and span wider regions of experimental
parameter space than Mun et. al. that encompasses most of their observations.
We speculate that this material has anomalous intrinsic properties and the
results cannot be explained by simple models about the flux lattice.Comment: 1 page, LaTeX type, 1 PostScript figure, Uses PRABIB.STY file, 600
dpi PS file available at http://sagar.physics.neu.edu/preprints.html To
appear in Physical Review Letter
Moved by the tears of others: emotion networking in the heritage sphere
There is no heritage without emotional sharing and clashing. This article explores the involvement of divergent emotions in heritage making by discussing the debate series of Imagine IC and the Reinwardt Academy and zooming in on the commemoration of slavery and imagery of ‘Black Pete’ in the Netherlands. We introduce ‘emotion networking’ as a methodology to approach present-day heritage production, aiming for a novel approach to engage with ‘the collective’
Critical State Flux Penetration and Linear Microwave Vortex Response in YBa_2Cu_3O_{7-x} Films
The vortex contribution to the dc field (H) dependent microwave surface
impedance Z_s = R_s+iX_s of YBa_2Cu_3O_{7-x} thin films was measured using
suspended patterned resonators. Z_s(H) is shown to be a direct measure of the
flux density B(H) enabling a very precise test of models of flux penetration.
Three regimes of field-dependent behavior were observed: (1) Initial flux
penetration occurs on very low field scales H_i(4.2K) 100Oe, (2) At moderate
fields the flux penetration into the virgin state is in excellent agreement
with calculations based upon the field-induced Bean critical state for thin
film geometry, parametrized by a field scale H_s(4.2K) J_c*d 0.5T, (3) for very
high fields H >>H_s, the flux density is uniform and the measurements enable
direct determination of vortex parameters such as pinning force constants
\alpha_p and vortex viscosity \eta. However hysteresis loops are in
disagreement with the thin film Bean model, and instead are governed by the low
field scale H_i, rather than by H_s. Geometric barriers are insufficient to
account for the observed results.Comment: 20 pages, LaTeX type, Uses REVTeX style files, Submitted to Physical
Review B, 600 dpi PostScript file with high resolution figures available at
http://sagar.physics.neu.edu/preprints.htm
Improved LIDT values for dielectric dispersive compensating mirrors applying ternary composites
The present contribution is addressed to an improved method to fabricate dielectric dispersive compensating mirrors (CMs) with an increased laser induced damage threshold (LIDT) by the use of ternary composite layers. Taking advantage of a novel in-situ phase monitor system, it is possible to control the sensitive deposition process more precisely. The study is initiated by a design synthesis, to achieve optimum reflection and GDD values for a conventional high low stack (HL)n. Afterwards the field intensity is analyzed, and layers affected by highest electric field intensities are exchanged by ternary composites of TaxSiyOz. Both designs have similar target specifications whereby one design is using ternary composites and the other one is distinguished by a (HL)n. The first layers of the stack are switched applying in-situ optical broad band monitoring in conjunction with a forward re-optimization algorithm, which also manipulates the layers remaining for deposition at each switching event. To accomplish the demanded GDD-spectra, the last layers are controlled by a novel in-situ white light interferometer operating in the infrared spectral range. Finally the CMs are measured in a 10.000 on 1 procedure according to ISO 21254 applying pulses with a duration of 130 fs at a central wavelength of 775 nm to determine the laser induced damage threshold. © 2016 SPIE. Downloading of the abstract is permitted for personal use only.DFG/EXC/QUESTVolkswagen StiftungBMBF/13N1155
Specific Polyunsaturated Fatty Acids Can Modulate in vitro Human moDC2s and Subsequent Th2 Cytokine Release
Allergy is becoming a rapidly increasing problem worldwide, and in vitro models are frequently used to study the mechanisms behind the different types of allergic response. The dendritic cell (DC)\u2013T-cell model can be used to study sensitization. However, lipopolysaccharide (LPS) is often used to maturate the DCs, but it gives rise to a DC1 phenotype, whereas Th2-driven inflammatory diseases such as allergy are characterized by the involvement of the DC2 phenotype. Our aim was to create a DC2\u2013T-cell human model (human moDC2s) to study in vitro sensitization and validate the model using polyunsaturated fatty acids (PUFAs) that were previously shown to have immunomodulatory properties. We found that the generated DC2s expressed OX40L and drove naive T-cells into IL-13 production of CD4+ effector T-cells. In line with in vivo findings, n 123 long-chain (LC)PUFA docosahexaenoic acid (DHA) effectively decreased the DC2's surface expression of OX40L, as well as the IL-12p40 and IL-23 cytokine production by DC2s and subsequently lowered IL-13 production by DC2-induced effector T-cells. Similar cytokine production effects were found with eicosapentaenoic acid (EPA) and arachidonic acid (AA), whereas linoleic acid (LA) increased OX40L surface expression and subsequent T-cell-derived IL-13/IFN\u3b3 ratios, suggesting an increased risk of allergy development. Altogether, these data show that human moDC2s are able to induce Th2-type IL-13 secretion by T-cell differentiated in the presence of these DC2s and that this model can be differentially modulated by PUFAs. These results are in line with previous in vivo studies using PUFAs, indicating that this model may be of use to predict in vivo outcomes
Thin superconducting disk with B-dependent Jc: Flux and current distributions
The critical state in a superconducting thin circular disk with an arbitrary
magnetic field dependence of the critical sheet current, Jc(B), is analyzed.
With an applied field Ba perpendicular to the disk, a set of coupled integral
equations for the flux and current distributions is derived. The equations are
solved numerically, and flux and current profiles are presented graphically for
several commonly used Jc(B) dependences. It is shown that for small Ba the flux
penetration depth can be described by an effective Bean model with a
renormalized Jc entering the leading term. We argue that these results are
qualitatively correct for thin superconductors of any shape. The results
contrast the parallel geometry behavior, where at small Ba the B-dependence of
the critical current can be ignored.Comment: RevTeX, 7 pages including 8 figure
Melatonin treatment in children with therapy-resistant monosymptomatic nocturnal enuresis
Objective: To evaluate the effects of exogenous melatonin on the frequency of wet nights, on the sleep-wake cycle, and on the melatonin profile in children with therapy-resistant MNE. Patients and methods: 24 patients were included. Patients had to maintain a diary including time of sleep and arousal, and whether they had a dry or a wet bed in the morning. We measured baseline melatonin profiles in saliva. Hereafter, patients were randomized to synthetic melatonin or placebo. After 3 and 6 months we evaluated the frequency of enuresis and the melatonin profiles. Results: 11 patients were randomized to melatonin, 13 to placebo. We evaluated melatonin profiles of 7 patients in the melatonin group and of 8 in the placebo group. We observed a change in profile in the melatonin group, but we did not observe a difference in the sleep-wake cycle or the frequency of wet nights in either group. Conclusion: This is the first time exogenous melatonin has been evaluated in the treatment of MNE. Although we observed a change in melatonin profile after the use of exogenous melatonin, we did not observe a change in enuresis frequency or in the sleep-wake cycle of this select group of patients. (C) 2011 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved
Numerical simulations of a swimmer’s head and cap wearing different types of goggles
The aim of this study was to analyse the effect of swimming goggles on swimming hydrodynamics by numerical simulations. An elite swimmer volunteered for this research. The swimmer's head was scanned both without goggles, and while wearing 3 different types of goggles (Nikko, Ankor and Swedish). Numerical simulations were conducted at 2 m/s with the Fluent code. The condition without goggles showed the highest viscous drag (1.65Â N), followed by the Ankor (1.64Â N), Swedish (1.63Â N) and Nikko (1.62Â N) goggles, respectively. The highest pressure drag was found in the situation without goggles (11.34Â N), followed by the Ankor (10.87Â N), Nikko (10.78Â N) and Swedish (10.20Â N) goggles. The condition without goggles presented the highest total drag (12.99Â N), followed by the Ankor (12.52Â N), Nikko (12.40Â N) and Swedish (11.83Â N) goggles. Thus, Swedish goggles yields the best hydrodynamics, followed by the Nikko and Ankor goggles and lastly without goggles. Thus, goggles minimise the swimmer's drag comparing to not wearing any. The design of the goggles may impose varying drag forces and therefore it is advised to use goggles at least in competition.This work was supported by the Portuguese Foundation for Science and Technology, I.P. [UIDB04045/2020].info:eu-repo/semantics/publishedVersio
Transcatheter edge-to-edge repair of tricuspid regurgitation in the Netherlands:state of the art and future perspectives
Despite the high prevalence and adverse clinical outcomes of severe tricuspid regurgitation (TR), conventional treatment options, surgical or pharmacological, are limited. Surgery is associated with a high peri-operative risk and medical treatment has not clearly resulted in clinical improvements. Therefore, there is a high unmet need to reduce morbidity and mortality in patients with severe TR. During recent years, several transcatheter solutions have been studied. This review focuses on the transcatheter edge-to-edge repair of TR (TTVR) with respect to patient selection, the procedure, pre- and peri-procedural echocardiographic assessments and clinical outcomes. Furthermore, we highlight the current status of TTVR in the Netherlands and provide data from our initial experience at the University Medical Centre Groningen
Growth Diagrams for Individual Finger Strength in Children Measured with the RIHM
Background: Although grip and pinch strength provide a more global measure of a large number of digits and muscles, measuring strength of individual fingers or the thumb can provide additional and more detailed information regarding hand strength. Questions/purposes: We developed growth diagrams for individual finger strength in children. Patients and Methods: We measured thumb palmar abduction, thumb opposition, and thumb flexion in the metacarpophalangeal joint, and abduction of the index and little fingers in 101 children (4-12 years old) using a myometer. We recorded hand dominance, gender, height, and weight. All measurements were performed in a randomized order by the same researcher. We developed statistical models for drawing growth diagrams using estimated percentiles for each strength measurement. Separate models for dominant and nondominant hands of boys and girls were developed, in addition to a combined model. Results: Because there was no difference in strength between boys and girls and between dominant and nondominant hands, both hands and genders were combined in one growth diagram for each measurement. The normative data were presented in a table format and in growth diagrams for each myometer measurement. Conclusions: These diagrams can be used for pediatric patients such as patients with congenital malformations or neuromuscular disorders who receive interventions or therapy aimed at function of the hand, fingers, or thumb. The growth diagrams facilitate distinguishing between the effects of growth and intervention on strength development
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