Abstract
We report an unusual pressure-induced superconducting state that coexists with an antiferromagnetic ordering of Eu
2+
moments and shows a large upper critical field comparable to the Pauli ...paramagnetic limit in EuTe
2
. In concomitant with the emergence of superconductivity with
T
c
≈ 3–5 K above
P
c
≈ 6 GPa, the antiferromagnetic transition temperature
T
N
(
P
) experiences a quicker rise with the slope increased dramatically from d
T
N
/d
P
= 0.85(14) K/GPa for
P
≤
P
c
to 3.7(2) K/GPa for
P
≥
P
c
. Moreover, the superconducting state can survive in the spin-flop state with a net ferromagnetic component of the Eu
2+
sublattice under moderate magnetic fields
μ
0
H
≥ 2 T. Our findings establish the pressurized EuTe
2
as a rare magnetic superconductor possessing an intimated interplay between magnetism and superconductivity.
At the end of a rush lasting over half a century, in which CMOS technology has been experiencing a constant and breathtaking increase of device speed and density, Moore's law is approaching the ...insurmountable barrier given by the ultimate atomic nature of matter. A major challenge for 21st century scientists is finding novel strategies, concepts and materials for replacing silicon-based CMOS semiconductor technologies and guaranteeing a continued and steady technological progress in next decades. Among the materials classes candidate to contribute to this momentous challenge, oxide films and heterostructures are a particularly appealing hunting ground. The vastity, intended in pure chemical terms, of this class of compounds, the complexity of their correlated behaviour, and the wealth of functional properties they display, has already made these systems the subject of choice, worldwide, of a strongly networked, dynamic and interdisciplinary research community.
Oxide science and technology has been the target of a wide four-year project, named Towards Oxide-Based Electronics (TO-BE), that has been recently running in Europe and has involved as participants several hundred scientists from 29 EU countries. In this review and perspective paper, published as a final deliverable of the TO-BE Action, the opportunities of oxides as future electronic materials for Information and Communication Technologies ICT and Energy are discussed. The paper is organized as a set of contributions, all selected and ordered as individual building blocks of a wider general scheme. After a brief preface by the editors and an introductory contribution, two sections follow. The first is mainly devoted to providing a perspective on the latest theoretical and experimental methods that are employed to investigate oxides and to produce oxide-based films, heterostructures and devices. In the second, all contributions are dedicated to different specific fields of applications of oxide thin films and heterostructures, in sectors as data storage and computing, optics and plasmonics, magnonics, energy conversion and harvesting, and power electronics.
Our meta-analysis assessed the efficacy of statins on the risk of fracture, bone mineral density (BMD), and the markers of bone metabolism by collecting data from 33 clinical trials. We found that ...statin treatment was associated with bone metabolism. And statins seemed to be more effective on male patients with osteoporosis. The efficacy of statins for the treatment of osteoporosis has been controversial in previous studies and meta-analyses. Our meta-analysis was conducted to examine in detail the efficacy of statins on osteoporosis. We searched PubMed, Embase, and the Cochrane Library databases for clinical trials from inception to May 2016. We included studies that described the effect of statins on the risk of fracture, BMD, or bone turnover markers. Moreover, we also conducted subgroup analyses according to the skeleton site, patient gender, and length of follow-up. A total of 33 studies which included 23 observational studies (16 cohort studies and 7 case-control studies) and 10 randomized controlled trials (RCTs) were evaluated. These 33 studies included 314,473 patients in statin group and 1,349,192 patients in control group. Statins decreased the risk of overall fractures (OR = 0.81, 95% CI 0.73–0.89) and hip fractures (OR = 0.75, 95% CI 0.60–0.92). Furthermore, the use of statins was associated with increased BMD at the total hip (standardized mean difference (SMD) = 0.18, 95% CI 0.00–0.36) and lumbar spine (SMD = 0.20, 95% CI 0.07–0.32) and improved the bone formation marker, osteocalcin (OC) (SMD = 0.21, 95% CI 0.00–0.42). However, there was no positive effect on vertebral fractures, upper extremity fractures, BMD at the femoral neck, bone-specific alkaline phosphatase (BALP), and serum C-terminal peptide of type I collagen (S-CTX). Also, compared with male subgroups, the effect on female subgroups was only slightly positive or of no statistical significance. Our meta-analysis indicates that statin treatment may be associated with a decreased risk of overall fractures and hip fractures, an increased BMD at the total hip, BMD at the lumbar spine, and OC. Moreover, our results also show that statin treatment may have a greater effect on male patients than on female patients.
Staphylococcus aureus is an important human pathogen that causes skin and soft tissue abscesses. Abscess formation is not unique to staphylococcal infection and purulent discharge has been widely ...considered a physiological feature of healing and tissue repair. Here we present a different view, whereby S. aureus deploys specific virulence factors to promote abscess lesions that are distinctive for this pathogen. In support of this model, only live S. aureus is able to form abscesses, requiring genes that act at one or more of four discrete stages during the development of these infectious lesions. Protein A and coagulases are distinctive virulence attributes for S . aureus, and humoral immune responses specific for these polypeptides provide protection against abscess formation in animal models of staphylococcal disease.
We evaluate the influence of pressure on the thermoelectric power factors PF ≡
S
2
σ
of pristine and Na-doped SnSe crystals by measuring their electrical conductivity
σ
(
T
) and Seebeck coefficient
...S
(
T
) up to ∼22 kbar with a self-clamped piston-cylinder cell. For both cases,
σ
(
T
) is enhanced while
S
(
T
) reduced with increasing pressure as expected, but their imbalanced variations lead to a monotonic enhancement of PF under pressure. For pristine SnSe,
σ
(290 K) increases by ∼4 times from ∼10.1 to 38 S cm
−1
, while
S
(290 K) decreases by only ∼12% from 474 to 415 μV K
−1
, leading to about three-fold enhancement of PF from 2.24 to 6.61 μW cm
−1
K
−2
, which is very close to the optimal value of SnSe above the structural transition at ∼800 K at ambient pressure. In comparison, the PF of Na-doped SnSe at 290 K is enhanced moderately by ∼30% up to 20 kbar. In contrast, the PF of isostructural black phosphorus with a simple band structure was found to decrease under pressure. The comparison with black phosphorus indicates that the multi-valley valence band structure of SnSe is beneficial for the enhancement of PF by retaining a large Seebeck coefficient under pressure. Our results also provide experimental confirmation on the previous theoretical prediction that high pressure can be used to optimize the thermoelectric efficiency of SnSe.
The thermoelectric power factor of SnSe is enhanced by three times under a hydrostatic pressure of 22.5 kbar.
Summary
In this meta-analysis, we evaluated the association between serum 25-hydroxyvitamin D (25(OH) vitamin D) level and the risk of total fractures and hip fractures. Low serum 25(OH) vitamin D ...level is associated with an increased risk of total and hip fractures.
Introduction
Data on the association between serum 25(OH) vitamin D level and the risk of fractures are conflicting. This study aimed to provide a summary of prospective cohort or nested case–control studies on the association between serum 25(OH) vitamin D level and the risk of total fractures and hip fractures.
Methods
We identified relevant studies by searching the PubMed, EMBASE, and OVID databases from their inception to June 1, 2016. We included published prospective cohort or nested case–control studies evaluating the associations of serum 25(OH) vitamin D level with the fracture risk. Two reviewers abstracted the data independently. Relative risks (RRs) with 95% confidence intervals (CIs) were derived throughout the whole analysis.
Results
Sixteen prospective cohort studies and three nested case–control studies were included. We found that low serum 25(OH) vitamin D level was significantly associated with the risk of total fractures (RR 1.25, 95% CI 1.06–1.43;
I
2
= 31.3%,
p
for heterogeneity = 0.15) and hip fractures (RR 1.48, 95% CI 1.29–1.68;
I
2
= 0%,
p
for heterogeneity = 0.51). The hip fracture risk was increased by 40% for each SD decrease in serum 25(OH) vitamin D level (RR 1.40, 95% CI 1.20–1.61;
I
2
= 0%,
p
for heterogeneity = 0.51). The per SD decrease in serum 25(OH) vitamin D level was not associated with the increased risk of total fractures (RR 1.14, 95% CI 0.93–1.35;
I
2
= 63.2%,
p
for heterogeneity = 0.04).
Conclusions
Our study suggests that low serum 25(OH) vitamin D level is associated with increased risks of total and hip fractures. In the analyzed studies, the per SD decrease in serum 25(OH) vitamin D level was associated with the hip fracture risk but not with the total fracture risk.
Millimeter-sized MnBi2Te4 single crystals are grown out of a Bi-Te flux and characterized using magnetic, transport, scanning tunneling microscopy, and spectroscopy measurements. The magnetic ...structure of MnBi2Te4 below TN is determined by powder and single-crystal neutron diffraction measurements. Below TN = 24 K, Mn2+ moments order ferromagnetically in the ab plane but antiferromagnetically along the crystallographic c axis. The ordered moment is 4.04(13)μB/Mn at 10 K and aligned along the crystallographic c axis in an A-type antiferromagnetic order. Below TN, the electrical resistivity drops upon cooling or when going across the metamagnetic transition in increasing magnetic fields. A critical scattering effect is observed in the vicinity of TN in the temperature dependence of thermal conductivity, indicating strong spin-lattice coupling in this compound. Yet, no anomaly is observed in the temperature dependence of thermopower around TN. Fine tuning of the magnetism and/or electronic band structure is needed for the proposed topological properties of this compound. The growth protocol reported here might be applied to grow high-quality crystals where the electronic band structure and magnetism can be finely tuned by chemical substitutions.
Sensory hair cells are mechanoreceptors of the auditory and vestibular systems and are crucial for hearing and balance. In adult mammals, auditory hair cells are unable to regenerate, and damage to ...these cells results in permanent hearing loss. By contrast, hair cells in the chick cochlea and the zebrafish lateral line are able to regenerate, prompting studies into the signaling pathways, morphogen gradients and transcription factors that regulate hair cell development and regeneration in various species. Here, we review these findings and discuss how various signaling pathways and factors function to modulate sensory hair cell development and regeneration. By comparing and contrasting development and regeneration, we also highlight the utility and limitations of using defined developmental cues to drive mammalian hair cell regeneration.
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