4,587 research outputs found

    Type-1.5 Superconductors

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    We demonstrate the existence of a novel superconducting state in high quality two-component MgB2 single crystalline superconductors where a unique combination of both type-1 (kappa_1 0.707) superconductor conditions is realized for the two components of the order parameter. This condition leads to a vortex-vortex interaction attractive at long distances and repulsive at short distances, which stabilizes unconventional stripe- and gossamer-like vortex patterns that we have visualized in this type-1.5 superconductor using Bitter decoration and also reproduced in numerical simulations.Comment: accepted in Phys. Rev. Let

    Optothermotronic effect as an ultrasensitive thermal sensing technology for solid-state electronics

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    The thermal excitation, regulation, and detection of charge carriers in solid-state electronics have attracted great attention toward high-performance sensing applications but still face major challenges. Manipulating thermal excitation and transport of charge carriers in nanoheterostructures, we report a giant temperature sensing effect in semiconductor nanofilms via optoelectronic coupling, termed optothermotronics. A gradient of charge carriers in the nanofilms under nonuniform light illumination is coupled with an electric tuning current to enhance the performance of the thermal sensing effect. As a proof of concept, we used silicon carbide (SiC) nanofilms that form nanoheterostructures on silicon (Si). The sensing performance based on the thermal excitation of charge carriers in SiC is enhanced by at least 100 times through photon excitation, with a giant temperature coefficient of resistance (TCR) of up to −50%/K. Our findings could be used to substantially enhance the thermal sensing performance of solid-state electronics beyond the present sensing technologies

    A review of the MSCA ITN ECOSTORE - Novel complex metal hydrides for efficient and compact storage of renewable energy as hydrogen and electricity

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    Hydrogen as an energy carrier is very versatile in energy storage applications. Developments in novel, sustainable technologies towards a CO2-free society are needed and the exploration of all-solid-state batteries (ASSBs) as well as solid-state hydrogen storage applications based on metal hydrides can provide solutions for such technologies. However, there are still many technical challenges for both hydrogen storage material and ASSBs related to designing low-cost materials with low-environmental impact. The current materials considered for all-solid-state batteries should have high conductivities for Na+, Mg2+ and Ca2+, while Al3+-based compounds are often marginalised due to the lack of suitable electrode and electrolyte materials. In hydrogen storage materials, the sluggish kinetic behaviour of solid-state hydride materials is one of the key constraints that limit their practical uses. Therefore, it is necessary to overcome the kinetic issues of hydride materials before discussing and considering them on the system level. This review summarizes the achievements of the Marie Skłodowska-Curie Actions (MSCA) innovative training network (ITN) ECOSTORE, the aim of which was the investigation of different aspects of (complex) metal hydride materials. Advances in battery and hydrogen storage materials for the efficient and compact storage of renewable energy production are discussed

    Mass Dependence of M3Y-Type Interactions and the Effects of Tensor Correlations

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    The mass dependence of the M3Y-type effective interactions and the effects of tensor correlations are examined. Two-body nuclear matrix elements are obtained by the lowest order constrained variational (LOCV) technique with and without tensor correlations. We have found that the tensor correlations are important especially in the triplet-even (TE) and tensor-even (TNE) channels in order to reproduce the G-matrix elements obtained previously. Then M3Y-type potentials for inelastic scattering are obtained by fitting our two-body matrix elements to those of a sum of Yukawa functions for the mass numbers A=24, A=40 and A=90.Comment: 13 pages, 6 table

    Sources of Multidrug Resistance in Patients With Previous Isoniazid-Resistant Tuberculosis Identified Using Whole Genome Sequencing: A Longitudinal Cohort Study

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    Background Meta-analysis of patients with isoniazid-resistant tuberculosis given standard first-line anti-tuberculosis treatment indicated an increased risk of multi-drug resistant tuberculosis (MDR-TB) emerging (8%), compared to drug-sensitive tuberculosis (0.3%). Here we use whole genome sequencing (WGS) to investigate whether treatment of patients with pre-existing isoniazid resistant disease with first-line anti-tuberculosis therapy risks selecting for rifampicin resistance, and hence MDR-TB. Methods Patients with isoniazid-resistant pulmonary TB were recruited and followed up for 24 months. Drug-susceptibility testing was performed by Microscopic observation drug-susceptibility assay (MODS), Mycobacterial Growth Indicator Tube (MGIT) and by WGS on isolates at first presentation and in the case of re-presentation. Where MDR-TB was diagnosed, WGS was used to determine the genomic relatedness between initial and subsequent isolates. De novo emergence of MDR-TB was assumed where the genomic distance was five or fewer single nucleotide polymorphisms (SNPs) whereas reinfection with a different MDR-TB strain was assumed where the distance was 10 or more SNPs. Results 239 patients with isoniazid-resistant pulmonary tuberculosis were recruited. Fourteen (14/239, 5.9%) patients were diagnosed with a second episode of tuberculosis that was multi-drug resistant. Six (6/239, 2.5%) were identified as having evolved MDR-TB de novo and six as having been re-infected with a different strain. In two cases the genomic distance was between 5-10 SNPs and therefore indeterminate. Conclusions In isoniazid-resistant TB, de novo emergence and reinfection of MDR-TB strains equally contributed to MDR development. Early diagnosis and optimal treatment of isoniazid resistant TB are urgently needed to avert the de novo emergence of MDR-TB during treatment

    Regularity of Edge Ideals and Their Powers

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    We survey recent studies on the Castelnuovo-Mumford regularity of edge ideals of graphs and their powers. Our focus is on bounds and exact values of  reg I(G)\text{ reg } I(G) and the asymptotic linear function  reg I(G)q\text{ reg } I(G)^q, for q1,q \geq 1, in terms of combinatorial data of the given graph G.G.Comment: 31 pages, 15 figure

    Born-Infeld-type phantom on the brane world

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    We study the evolution of Born-Infeld-type phantom in the second Randall-Sundrum brane scenario, and find that there exists attractor solution for the potential with a maximum, which implies a cosmological constant at the late time. Especially, we discuss the BI model of constant potential without and with dust matter. In the weak tension limit of the brane, we obtain an exact solution for the BI phantom and scale factor and show that there is no big rip during the evolution of the brane.Comment: 5 pages, 2 figures, Reference added, Phys. Rev. D in pres

    Reproductive Safety of Trazodone After Maternal Exposure in Early Pregnancy: A Comparative ENTIS Cohort Study.

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    Trazodone is indicated for the treatment of major depressive disorder, but more frequently prescribed off-label at lower doses for insomnia in women of childbearing age. The aim of this study was to assess the risks linked to trazodone exposure during pregnancy for which limited safety data are available. This multicenter, observational prospective cohort study compared pregnancy outcomes in women exposed to trazodone in early pregnancy against those in a reference group of women exposed to a selective serotonin reuptake inhibitors (SSRIs) between 1996 and 2021. The sample included 221 trazodone and 869 SSRI-exposed pregnancies. Exposure to trazodone in the first trimester was not associated with a significant difference in the risk of major congenital anomalies (trazodone [1/169, 0.6%]; SSRI [19/730, 2.6%]; adjusted odds ratio, 0.2; 95% confidence interval, 0.03-1.77). The cumulative incidences of live birth were 61% and 73% in the trazodone and reference group, respectively (25% vs 18% for pregnancy loss and 14% vs 10% for pregnancy termination). Trazodone exposure was not associated with a significantly increased risk of pregnancy termination and pregnancy loss. The rate of small for gestational age infants did not differ between the groups. This study did not reveal a significant difference in the risk of major congenital anomalies after first trimester exposure to trazodone, compared with SSRI exposure. Although this study is the largest so far, these results call for confirmation through further studies

    Langevin Simulation of Thermally Activated Magnetization Reversal in Nanoscale Pillars

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    Numerical solutions of the Landau-Lifshitz-Gilbert micromagnetic model incorporating thermal fluctuations and dipole-dipole interactions (calculated by the Fast Multipole Method) are presented for systems composed of nanoscale iron pillars of dimension 9 nm x 9 nm x 150 nm. Hysteresis loops generated under sinusoidally varying fields are obtained, while the coercive field is estimated to be 1979 ±\pm 14 Oe using linear field sweeps at T=0 K. Thermal effects are essential to the relaxation of magnetization trapped in a metastable orientation, such as happens after a rapid reversal of an external magnetic field less than the coercive value. The distribution of switching times is compared to a simple analytic theory that describes reversal with nucleation at the ends of the nanomagnets. Results are also presented for arrays of nanomagnets oriented perpendicular to a flat substrate. Even at a separation of 300 nm, where the field from neighboring pillars is only \sim 1 Oe, the interactions have a significant effect on the switching of the magnets.Comment: 19 pages RevTeX, including 12 figures, clarified discussion of numerical technique

    Client preferences and acceptability for medical abortion and MVA as early pregnancy termination method in Northwest Ethiopia

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    <p>Abstract</p> <p>Background</p> <p>Increasing access to safe abortion services is the most effective way of preventing the burden of unsafe abortion, which is achieved by increasing safe choices for pregnancy termination. Medical abortion for termination of early abortion is said to safe, effective, and acceptable to women in several countries. In Ethiopia, however, medical methods have, until recently, never been used. For this reason it is important to assess women's preferences and the acceptability of medical abortion and manual vacuum aspiration (MVA) in the early first trimester pregnancy termination and factors affecting acceptability of medical and MVA abortion services.</p> <p>Methods</p> <p>A prospective study was conducted in two hospitals and two clinics from March 2009 to November 2009. The study population consisted of 414 subjects over the age of 18 with intrauterine pregnancies of up to 63 days' estimated gestation. Of these 251 subjects received mifepristone and misoprostol and 159 subjects received MVA. Questionnaires regarding expectations and experiences were administered before the abortion and at the 2-week follow-up visit.</p> <p>Results</p> <p>The study groups were similar with respect to age, marital status, educational status, religion and ethnicity. Their mean age was about 23, majority in both group completed secondary education and about half were married. Place of residence and duration of pregnancy were associated with method choice. Subjects undergoing medical abortions reported significantly greater satisfaction than those undergoing surgical abortions (91.2% vs 82.4%; <it>P </it>< .001). Of those women who had medical abortion, (83.3%) would choose the method again if needed, and (77.4%) of those who had MVA would also choose the method again. Ninety four percent of women who had medical abortion and 86.8% of those who had MVA would recommend the method to their friends.</p> <p>Conclusions</p> <p>Women receiving medical abortion were more satisfied with their method and more likely to choose the same method again than were subjects undergoing surgical abortion. We conclude that medical abortion can be used widely as an alternative method for early pregnancy termination.</p
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