195 research outputs found
Direct Observation of an Incommensurate Charge Density Wave in the BiS2-based Superconductor NdO1-xFxBiS2
The nature of superconductivity in BiS-based superconductors has been
controversial while ab-initio calculations proposed this system in close
proximity to a charge-density-wave (CDW) phase. Using high-energy high-flux
X-ray diffraction, we reveal an intrinsic and long-range CDW phase coexisting
with superconductivity in NdOFBiS superconductor ( = 0.37
and 0.3). The CDW wavevector in NdOFBiS correspond
Q = (0.17, 0.17, 0.5) and is associated with transverse atomic
displacements. Interestingly, this wavevector does not match theoretical
expectations based on either phonon softening or Fermi surface nesting. In
NdOFBiS, where the superconducting transition temperature
is highest, the CDW satellites are slightly broader and weaker compared to
NdOFBiS, possibly suggesting the competition with the
superconductivity. Lastly, we measure a thermal diffuse scattering across the
superconducting transition temperature and find no meaningful changes in favor
of the unconventional pairing mechanism. Our result suggests the importance of
understanding CDW which might hold a key to the superconductivity in the
BiS-based superconductor.Comment: 7 pages, 3 figures, Supplementary to be uploade
Definitive Evidence for Order-by-Quantum-Disorder in Er2Ti2O7
Here we establish the systematic existence of a U(1) degeneracy of all
symmetry-allowed Hamiltonians quadratic in the spins on the pyrochlore lattice,
at the mean-field level. By extracting the Hamiltonian of Er2Ti2O7 from
inelastic neutron scattering measurements, we then show that the
U(1)-degenerate states of Er2Ti2O7 are its classical ground states, and
unambiguously show that quantum fluctuations break the degeneracy in a way
which is confirmed by experiment. This is the first definitive observation of
order-by-disorder in any material. We provide further verifiable consequences
of this phenomenon, and several additional comparisons between theory and
experiment.Comment: 4.5 pages, 3 figures, 7.5 pages of Supplemental Material, 8
supplemental figure
Hygiene in the United States Brow Shaping Industry: A Benchmarking Report
Purpose: To provide a current benchmark of hand hygiene and brow cleansing in the brow shaping industry across the United States of America.
Background: Brow abscesses have been linked to the microtrauma associated with brow shaping. This paper provides an understanding of normative standards of hand hygiene and brow cleansing in the brow shaping industry at both the regional and national levels.
Methods: This project involved a phone survey of 255 brow salons across the United States – 5 from the most populous city in every state and Washington, D.C. Uni- and multivariate associations between regional and national brow hygiene practices were explored using chi-square testing and multinomial logistic regression modeling.
Results: Of 255 brow salons included in this study, 137 performed waxing (54%), 72 performed threading (28%) and 46 performed both (18%). Hand hygiene was required at 97% of brow salons, most commonly using alcohol-based sanitizer (59%), hand washing (22%), or some combination of the two (16%). Brow cleansing was required at 80% of salons, with the vast majority using an alcohol-based cleanser (75%). Multinomial logistic regression analysis of hand and brow hygiene methods, including hand hygiene frequency and service type, failed to show regionally predictive differences. Hand hygiene was performed more routinely than brow hygiene nationwide (p\u3c0.01).
Conclusions: The brow shaping industry is performing hand hygiene nearly across the board, but would benefit from increased rates of brow cleansing
Delaying histone deacetylase response to injury accelerates conversion into repair Schwann cells and nerve regeneration
The peripheral nervous system (PNS) regenerates after injury. However, regeneration is often compromised in the case of large lesions, and the speed of axon reconnection to their target is critical for successful functional recovery. After injury, mature Schwann cells (SCs) convert into repair cells that foster axonal regrowth, and redifferentiate to rebuild myelin. These processes require the regulation of several transcription factors, but the driving mechanisms remain partially understood. Here we identify an early response to nerve injury controlled by histone deacetylase 2 (HDAC2), which coordinates the action of other chromatin-remodelling enzymes to induce the upregulation of Oct6, a key transcription factor for SC development. Inactivating this mechanism using mouse genetics allows earlier conversion into repair cells and leads to faster axonal regrowth, but impairs remyelination. Consistently, short-term HDAC1/2 inhibitor treatment early after lesion accelerates functional recovery and enhances regeneration, thereby identifying a new therapeutic strategy to improve PNS regeneration after lesion
Prevalence of Cancer in Adult Patients with Atopic Dermatitis:A Nationwide Study
Abstract is missing (Short communication
Disorder raises the critical temperature of a cuprate superconductor
With the discovery of charge density waves (CDW) in most members of the
cuprate high temperature superconductors, the interplay between
superconductivity and CDW has become a key point in the debate on the origin of
high temperature superconductivity. Some experiments in cuprates point toward a
CDW state competing with superconductivity, but others raise the possibility of
a CDW-superconductivity intertwined order, or more elusive pair-density wave
(PDW). Here we have used proton irradiation to induce disorder in crystals of
LaBaCuO and observed a striking 50% increase of
accompanied by a suppression of the CDW. This is in clear
contradiction with the behaviour expected of a d-wave superconductor for which
both magnetic and non-magnetic defects should suppress . Our
results thus make an unambiguous case for the strong detrimental effect of the
CDW on bulk superconductivity in LaBaCuO. Using tunnel
diode oscillator (TDO) measurements, we find evidence for dynamic layer
decoupling in PDW phase. Our results establish irradiation-induced disorder as
a particularly relevant tuning parameter for the many families of
superconductors with coexisting density waves, which we demonstrate on
superconductors such as the dichalcogenides and LuIrSi.Comment: 10 pages, 7 figure
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