173 research outputs found
Depairing critical current achieved in superconducting thin films with through-thickness arrays of artificial pinning centers
Large area arrays of through-thickness nanoscale pores have been milled into
superconducting Nb thin films via a process utilizing anodized aluminum oxide
thin film templates. These pores act as artificial flux pinning centers,
increasing the superconducting critical current, Jc, of the Nb films. By
optimizing the process conditions including anodization time, pore size and
milling time, Jc values approaching and in some cases matching the
Ginzburg-Landau depairing current of 30 MA/cm^2 at 5 K have been achieved - a
Jc enhancement over as-deposited films of more than 50 times. In the field
dependence of Jc, a matching field corresponding to the areal pore density has
also been clearly observed. The effect of back-filling the pores with magnetic
material has then been investigated. While back-filling with Co has been
successfully achieved, the effect of the magnetic material on Jc has been found
to be largely detrimental compared to voids, although a distinct influence of
the magnetic material in producing a hysteretic Jc versus applied field
behavior has been observed. This behavior has been tested for compatibility
with currently proposed models of magnetic pinning and found to be most closely
explained by a model describing the magnetic attraction between the flux
vortices and the magnetic inclusions.Comment: 9 pages, 10 figure
Mobile/Modular BSL-4 Containment Facilities Integrated into a Curation Receiving Laboratory for Restricted Earth Return Missions
NASA robotic sample return missions designated Category V Restricted Earth Return by the NASA Planetary Protection (PP) Office require sample containment and biohazard testing upon return to Earth. Since the 1960s, sample containment from an unknown extraterrestrial biohazard have been related to the highest containment standards and protocols known to modern science. Today, this is Biosafety Level (BSL) 4 containment. In the U.S., the Biosafety in Microbiological and Biomedical Laboratories publication authored by the U.S. Department of Health and Human Services (HHS): Public Health Service, Centers for Disease Control and Prevention, and the National Institutes of Health houses the primary recommendations, standards, and design requirements for all BSL labs. Past mission concept studies for constructing a NASA Curation Receiving Laboratory with an integrated BSL-4 quarantine and biohazard testing facility have been estimated in the hundreds of millions of dollars (USD). As an alternative option, we have conducted a trade study for constructing a mobile and/or modular sample containment laboratory that would meet all BSL-4 and planetary protection standards and protocols at a fraction of the cost. Mobile and modular BSL-2 and 3 facilities have been successfully constructed and deployed world-wide for government testing of pathogens and pharmaceutical production. Our study showed that a modular BSL-4 construction could result in ~ 90% cost reduction when compared to traditional BSL-4 construction methods without compromising the preservation of the samples or Earth. For the design/construction requirements of a mobile/modular BSL-4 containment, we used the established HHS document standards and protocols for manipulation of agents in Class III Biosafety Cabinets (BSC; i.e., negative pressure gloveboxes) that are currently followed in operational BSL-4 facilities in the U.S
Dna2 is a structure-specific nuclease, with affinity for 5'-flap intermediates
Dna2 is a nuclease/helicase with proposed roles in DNA replication, double-strand break repair and telomere maintenance. For each role Dna2 is proposed to process DNA substrates with a 5'-flap. To date, however, Dna2 has not revealed a preference for binding or cleavage of flaps over single-stranded DNA. Using DNA binding competition assays we found that Dna2 has substrate structure specificity. The nuclease displayed a strong preference for binding substrates with a 5'-flap or some variations of flap structure. Further analysis revealed that Dna2 recognized and bound both the single-stranded flap and portions of the duplex region immediately downstream of the flap. A model is proposed in which Dna2 first binds to a flap base, and then the flap threads through the protein with periodic cleavage, to a terminal flap length of ~5 nt. This resembles the mechanism of flap endonuclease 1, consistent with cooperation of these two proteins in flap processing
Superconductor-ferromagnet nanocomposites created by co-deposition of niobium and dysprosium
We have created superconductor-ferromagnet composite films in order to test
the enhancement of critical current density, Jc, due to magnetic pinning. We
co-sputter the type-II superconductor niobium (Nb) and the low-temperature
ferromagnet dysprosium (Dy) onto a heated substrate; the immiscibility of the
two materials leads to a phase-separated composite of magnetic regions within a
superconducting matrix. Over a range of compositions and substrate
temperatures, we achieve phase separation on scales from 5 nm to 1 micron. The
composite films exhibit simultaneous superconductivity and ferromagnetism.
Transport measurements show that while the self-field Jc is reduced in the
composites, the in-field Jc is greatly enhanced up to the 3 T saturation field
of Dy. In one instance, the phase separation orders into stripes, leading to
in-plane anisotropy in Jc.Comment: 7 pages, 7 figures. Matches the version published in SUST: Added one
reference and some discussion in Section
PenQuest Volume 1, Number 2
Table of Contents for this Volume:
Untitled by Julie Ambrose
Night by Judith Gallo
Untitled by Judy Gozdur
the shamans by Charles Riddles
Untitled by Jerry Connell
Untitled by Laura Woods
Untitled by LEMA
Wicked Bird by Laura Jo Last
Untitled by Rick Dentos
Untitled by Jeni Moody
Untitled by Bettie W. Kwibs
Untitled by Joann Stagg
The Protector Stood by Laura Jo Last
Visions of Salome by Charles Riddles
Untitled by Thomas Tutten
Kennesaw Line by Don Ova-Dunaway
Stone Blood by Mary Ellen C. Wofford
Untitled by Roger Whitt Jr.
Untitled by C. Wingate
Untitled by Doug Dorey
Untitled by Karen Blumberg
Untitled by Beverly Oviatt
Untitled by Virginia Shrader
The Crapulous Credo of Charles C. by Charles Riddles
the brave and the true by David Reed
Untitled by Charles Gutierrez
Canoe Creek by Patricia Kraft
Untitled by Linda Bobinger
The Man in the Iron Lung by Patricia Kraft
Untitled by Roger Whitt, Jr.
Childish Things by Kathleen Gay
Untitled by Joseph Avanzini
The Lover by Mary S. Aken
Untitled by Ann Harrington
And He Taketh Away by David Reed
Untitled by Mary Graham
Untitled by Melody A. Cummons
Untitled by Karen Blumberg
To The Poets by Judith Gallo
Untitled by Ann Harringto
Randomized trials fit for the 21st century. A joint opinion from the European Society of Cardiology, American Heart Association, American College of Cardiology, and the World Heart Federation
© The Author(s) 2022. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (https://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. The articles are identical except for minor stylistic and spelling differences in keeping with each journal's style. When citing this article, a citation from any of the journals listed is appropriate. For commercial re-use, please contact [email protected] controlled trials are the cornerstone for reliably evaluating therapeutic strategies. However, during the past 25 years, the rules and regulations governing randomized trials and their interpretation have become increasingly burdensome, and the cost and complexity of trials has become prohibitive. The present model is unsustainable, and the development of potentially effective treatments is often stopped prematurely on financial grounds, while existing drug treatments or non-drug interventions (such as screening strategies or management tools) may not be assessed reliably. The current ‘best regulatory practice’ environment, and a lack of consensus on what that requires, too often makes it unduly difficult to undertake efficient randomized trials able to provide reliable evidence about the safety and efficacy of potentially valuable interventions. Inclusion of underrepresented population groups and lack of diversity also remain among the
challenges.info:eu-repo/semantics/publishedVersio
Phenomenology of bipolar disorder not otherwise specified in youth: a comparison of clinical characteristics across the spectrum of manic symptoms
Controversy surrounds the diagnostic categorization of children with episodic moods that cause impairment, but do not meet DSM-IV criteria for bipolar I (BD-I) or bipolar II (BD-II) disorder. This study aims to characterize the degree to which these children, who meet criteria for bipolar disorder not otherwise specified (BD-NOS), are similar to those with full syndromal BD, versus those with no bipolar spectrum diagnosis (no BSD)
Examining the Proposed Disruptive Mood Dysregulation Disorder Diagnosis in Children in the Longitudinal Assessment of Manic Symptoms Study
To examine the proposed disruptive mood dysregulation disorder (DMDD) diagnosis in a child psychiatric outpatient population. Evaluation of DMDD included 4 domains: clinical phenomenology, delimitation from other diagnoses, longitudinal stability, and association with parental psychiatric disorders
The nuclear receptor PPARγ selectively inhibits Th17 differentiation in a T cell–intrinsic fashion and suppresses CNS autoimmunity
T helper cells secreting interleukin (IL)-17 (Th17 cells) play a crucial role in autoimmune diseases like multiple sclerosis (MS). Th17 differentiation, which is induced by a combination of transforming growth factor (TGF)-β/IL-6 or IL-21, requires expression of the transcription factor retinoic acid receptor–related orphan receptor γt (RORγt). We identify the nuclear receptor peroxisome proliferator–activated receptor γ (PPARγ) as a key negative regulator of human and mouse Th17 differentiation. PPARγ activation in CD4+ T cells selectively suppressed Th17 differentiation, but not differentiation into Th1, Th2, or regulatory T cells. Control of Th17 differentiation by PPARγ involved inhibition of TGF-β/IL-6–induced expression of RORγt in T cells. Pharmacologic activation of PPARγ prevented removal of the silencing mediator for retinoid and thyroid hormone receptors corepressor from the RORγt promoter in T cells, thus interfering with RORγt transcription. Both T cell–specific PPARγ knockout and endogenous ligand activation revealed the physiological role of PPARγ for continuous T cell–intrinsic control of Th17 differentiation and development of autoimmunity. Importantly, human CD4+ T cells from healthy controls and MS patients were strongly susceptible to PPARγ-mediated suppression of Th17 differentiation. In summary, we report a PPARγ-mediated T cell–intrinsic molecular mechanism that selectively controls Th17 differentiation in mice and in humans and that is amenable to pharmacologic modulation. We therefore propose that PPARγ represents a promising molecular target for specific immunointervention in Th17-mediated autoimmune diseases such as MS
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