Point group symmetry of cadmium arsenide thin films determined by convergent beam electron diffraction

Cadmium arsenide (Cd3As2) is one of the first materials to be discovered to belong to the class of three-dimensional topological semimetals. Reported room temperature crystal structures of Cd3As2 reported differ subtly in the way the Cd vacancies are arranged within its antifluorite-derived structure, which determines if an inversion center is present and if Cd3As2 is a Dirac or Weyl semimetal. Here, we apply convergent beam electron diffraction (CBED) to determine the point group of Cd3As2 thin films grown by molecular beam epitaxy. Using CBED patterns from multiple zone axes, high-angle annular dark-field images acquired in scanning transmission electron microscopy, and Bloch wave simulations, we show that Cd3As2 belongs to the tetragonal 4/mmm point group, which is centrosymmetric. The results show that CBED can distinguish very subtle differences in the crystal structure of a topological semimetal, a capability that will be useful for designing materials and thin film heterostructures with topological states that depend on the presence of certain crystal symmetries.Comment: Accepted for publication in Physical Review Material

Effect of Facilitated Tucking with the Nurse and a Simulated Hand on Physiological Pain Index During Vein Puncture on Premature Infants

BACKGROUND AND OBJECTIVE: Painful and stressful stimuli increase catecholamine, heart rate, blood pressure and increase the intracranial pressure of the baby. Facilitated tucking is a simple technique that makes the baby control her body better. Therefore, this study was performed to compare the effects of fetal status with hands of nurses and simulated hand on the physiological indices of pain during venipuncture in preterm infants. METHODS: The present experimental study was performed on 99 preterm infants admitted to the intensive care unit of Amin and Shahid Beheshti hospitals of Isfahan and in three groups of 33 patients (two groups of test and one control group). In one of the test groups during venipuncture procedure neonates were placed in facilitated tucking by nurse’s hand and in the other group by simulated hands. Before, during and after the intravenous route, the respiratory rate, pulse rate and arterial oxygen saturation were recorded using monitors. FINDINGS: The mean of arterial oxygen saturation during and after venipuncture in the nurses' hand group were (93.04±6.13) and (94.3±56.44) and in simulated hand group were (95.2±21.11) and (94.2±50.86%) which had no significant difference (p<0.05). Between the mean respiratory rate, during and after the venipuncture in the nurses' hand (49.9±85.88) and (54.11±03.85) with simulated hand group (50.64±11.48) and (57.10±96.82) was not significantly different. CONCLUSION: The results of the study showed that the use of nursing hands and simulated hands to put a premature infant in a facilitated tucking is effective equally in controlling the physiological indices

Two rare variants that affect the same amino acid in CFTR have distinct responses to ivacaftor

Some residues in the cystic fibrosis transmembrane conductance regulator (CFTR) channel are the site of more than one CFTR variant that cause cystic fibrosis. Here, we investigated the function of S1159F and S1159P, two variants associated with different clinical phenotypes, which affect the same pore-lining residue in transmembrane segment 12 that are both strongly potentiated by ivacaftor when expressed in CFBE41o− bronchial epithelial cells. To study the single-channel behaviour of CFTR, we applied the patch-clamp technique to Chinese hamster ovary cells heterologously expressing CFTR variants incubated at 27°C to enhance channel residence at the plasma membrane. S1159F- and S1159P-CFTR formed Cl− channels activated by cAMP-dependent phosphorylation and gated by ATP that exhibited thermostability at 37°C. Both variants modestly reduced the single-channel conductance of CFTR. By severely attenuating channel gating, S1159F- and S1159P-CFTR reduced the open probability (Po) of wild-type CFTR by ≥75% at ATP (1 mM); S1159F-CFTR caused the greater decrease in Po consistent with its more severe clinical phenotype. Ivacaftor (10–100 nM) doubled the Po of both CFTR variants without restoring Po values to wild-type levels, but concomitantly, ivacaftor decreased current flow through open channels. For S1159F-CFTR, the reduction of current flow was marked at high (supersaturated) ivacaftor concentrations (0.5–1 μM) and voltage-independent, identifying an additional detrimental action of elevated ivacaftor concentrations. In conclusion, S1159F and S1159P are gating variants, which also affect CFTR processing and conduction, but not stability, necessitating the use of combinations of CFTR modulators to optimally restore their channel activity

Enhanced Critical Field of Superconductivity at an Oxide Interface

The nature of superconductivity and its interplay with strong spin-orbit coupling at the KTaO3(111) interfaces remains a subject of debate. To address this problem, we grew epitaxial LaMnO3/KTaO3(111) heterostructures. We show that superconductivity is robust against the in-plane magnetic field, with the critical field of superconductivity reaching 25 T in optimally doped heterostructures. The superconducting order parameter is highly sensitive to carrier density. We argue that spin-orbit coupling drives the formation of anomalous quasiparticles with vanishing magnetic moment, providing the condensate significant immunity against magnetic fields beyond the Pauli paramagnetic limit. These results offer design opportunities for superconductors with extreme resilience against magnetic field

Microbial contamination of keyboards and electronic equipment of ICU (Intensive Care Units) in Kashan University of medical sciences and health service hospitals

Microbial contamination of computer keyboards and inanimate surfaces of electronic equipment in ICU (Intensive Care Units) can have a significant role for ICU-acquired colonization and a spectrum of nosocomial infections. The aim of this study was to survey the incidence of bacterial contamination and the distribution of species of computer keyboards and inanimate surfaces of bed side equipment in ICUs in Kashan University of medical sciences and health service hospitals. This descriptive, cross-sectional study was done on 75 computer keyboards and inanimate surfaces electronic equipment in 5 ICUs during 2016�2017. Samples were collected from computer keyboards and electronic equipment with normal saline rinsed swabs. Samples were Cultivated on Blood Agar (BA), and MacConkey Agar (MAC) and growing bacteria were identified based on their morphology and biochemical properties. Seventy six (76) out of 75 computer Keyboards and electronic equipment were contaminated with bacteria and fungi. The most contamination pertained to gram positive bacteria (70.7) and the most isolated bacteria were coagulase-negative staphylococci. The highest contamination rates were found on computer keyboards and electronic equipment of which were nurses. � This study demonstrates that monitoring inanimate surfaces and considering these surfaces as source of nosocomial infections is necessary. � In total, Seventy six (76) out of 75 computer keyboards and electronic equipment in ICUs had positive culture. � It can be concluded that it is necessary for ICUs of Kashan university of medical sciences and Health service hospitals to have practical and regular program to reduce nosocomial infections. © 2019 The Author(s