The role of temperature and Coulomb correlation in stabilization of CsCl-phase in FeS under pressure

The iron-sulfur system is important for planetary interiors and is intensely studied, particularly for better understanding of the cores of Mars and Earth. Yet, there is a paradox about high-pressure stability of FeS: ab initio global optimization (at DFT level) predicts a Pmmn phase (with a distorted rocksalt structure) to be stable at pressures above ~120 GPa, which has not yet been observed in the experiments that instead revealed a CsCl-type phase which, according to density functional calculations, should not be stable. Using quasiharmonic free energy calculations and the dynamical mean field theory, we show that this apparent discrepancy is removed by proper account of electron correlations and entropic effects.Comment: 5 pages, 3 figure

Alignment in Gamma-Hadron Families of Cosmic Rays

Alignment of main fluxes of energy in a target plane is found in families of cosmic ray particles detected in deep lead X-ray chambers. The fraction of events with alignment is unexpectedly large for families with high energy and large number of hadrons. This can be considered as evidence for the existence of coplanar scattering of secondary particles in interaction of particles with superhigh energy, $E_0 > 10^{16}$ eV. Data analysis suggests that production of most aligned groups occurs low above the chamber and is characterized by a coplanar scattering and quasiscaling spectrum of secondaries in the fragmentation region. The most elaborated hypothesis for explanation of alignment is related to the quark-gluon string rupture. However, the problem of theoretical interpretation of our results still remains open.Comment: 15 pages, 2 tables, 6 figures (not included), Stanford University preprint SU-ITP-94-2

Down syndrome and postoperative complications after paediatric cardiac surgery: a propensity-matched analysis

OBJECTIVESThe incidence of congenital heart disease is approximately 50%, mostly related to endocardial cushion defects. The aim of our study was to investigate the postoperative complications that occur after paediatric cardiac surgery.METHODSOur perioperative data were analysed in paediatric patients with Down syndrome undergoing cardiac surgery. We retrospectively analysed the data from 2063 consecutive paediatric patients between January 2003 and December 2008. After excluding the patients who died or had missing data, the analysed database (before propensity matching) contained 129 Down patients and 1667 non-Down patients. After propensity matching, the study population comprised 222 patients and 111 patients had Down syndrome.RESULTSBefore propensity matching, the occurrences of low output syndrome (21.2 vs 32.6%, P = 0.003), pulmonary complication (14 vs 28.7%, P < 0.001) and severe infection (11.9 vs 22.5%, P = 0.001) were higher in the Down group. Down patients were more likely to have prolonged mechanical ventilation [median (interquartile range) 22 (9-72) h vs 49 (24-117) h, P = 0.007]. The total intensive care unit length of stay [6.9 (4.2-12.4) days vs 8.3 (5.3-13.2) days, P = 0.04] and the total hospital length of stay [17.3 (13.3-23.2) days vs 18.3 (15.1-23.6) days, P = 0.05] of the Down patients were also longer. Mortality was similar in the two groups before (3.58 vs 3.88%, P = 0.86) and after (5.4 vs 4.5%, P = 1.00) propensity matching. After propensity matching, there was no difference in the occurrence of adverse events.CONCLUSIONSAfter propensity matching Down syndrome was not associated with increased mortality or complication rate following congenital cardiac surgery

Copper-catalysed selective hydroamination reactions of alkynes

The development of selective reactions that utilize easily available and abundant precursors for the efficient synthesis of amines is a long-standing goal of chemical research. Despite the centrality of amines in a number of important research areas, including medicinal chemistry, total synthesis and materials science, a general, selective and step-efficient synthesis of amines is still needed. Here, we describe a set of mild catalytic conditions utilizing a single copper-based catalyst that enables the direct preparation of three distinct and important amine classes (enamines, α-chiral branched alkylamines and linear alkylamines) from readily available alkyne starting materials with high levels of chemo-, regio- and stereoselectivity. This methodology was applied to the asymmetric synthesis of ​rivastigmine and the formal synthesis of several other pharmaceutical agents, including ​duloxetine, ​atomoxetine, ​fluoxetine and ​tolterodine.National Institutes of Health (U.S.) (GM58160

Anesthesiologists' and surgeons' perceptions about routine pre-operative testing in low risk patients: application of the Theoretical Domains Framework to identify factors that influence physicians' decisions to order pre-operative tests

Background Routine pre-operative tests for anesthesia management are often ordered by both anesthesiologists and surgeons for healthy patients undergoing low-risk surgery. The Theoretical Domains Framework (TDF) was developed to investigate determinants of behaviour and identify potential behaviour change interventions. In this study, the TDF is used to explore anaesthesiologists’ and surgeons’ perceptions of ordering routine tests for healthy patients undergoing low-risk surgery. Conclusion We identified key factors that anesthesiologists and surgeons believe influence whether they order pre-operative tests routinely for anesthesia management for a healthy adults undergoing low-risk surgery. These beliefs identify potential individual, team, and organisation targets for behaviour change interventions to reduce unnecessary routine test ordering. Methods Sixteen clinicians (eleven anesthesiologists and five surgeons) throughout Ontario were recruited. An interview guide based on the TDF was developed to identify beliefs about preoperative testing practices. Content analysis of physicians’ statements into the relevant theoretical domains was performed. Specific beliefs were identified by grouping similar utterances of the interview participants. Relevant domains were identified by noting the frequencies of the beliefs reported, presence of conflicting beliefs, and perceived influence on the performance of the behaviour under investigation. Results Seven of the twelve domains were identified as likely relevant to changing clinicians’ behaviour about pre-operative test ordering for anesthesia management. Key beliefs were identified within these domains including: conflicting comments about who was responsible for the test-ordering (Social/professional role and identity); inability to cancel tests ordered by fellow physicians (Beliefs about capabilities and social influences); and the problem with tests being completed before the anesthesiologists see the patient (Beliefs about capabilities and Environmental context and resources). Often, tests were ordered by an anesthesiologist based on who may be the attending anesthesiologist on the day of surgery while surgeons ordered tests they thought anesthesiologists may need (Social influences). There were also conflicting comments about the potential consequences associated with reducing testing, from negative (delay or cancel patients’ surgeries), to indifference (little or no change in patient outcomes), to positive (save money, avoid unnecessary investigations) (Beliefs about consequences). Further, while most agreed that they are motivated to reduce ordering unnecessary tests (Motivation and goals), there was still a report of a gap between their motivation and practice (Behavioural regulation)

Old puzzle of incommensurate crystal structure of calaverite AuTe2 and predicted stability of novel AuTe compound

Gold is a very inert element, which forms relatively few compounds. Among them is a unique material-mineral calaverite, AuTe2. Besides being the only compound in nature from which one can extract gold on an industrial scale, it is a rare example of a natural mineral with incommensurate crystal structure. Moreover, it is one of few systems based on Au, which become superconducting (at elevated pressure or doped by Pd and Pt). Using ab initio calculations we theoretically explain these unusual phenomena in the picture of negative charge-transfer energy and self-doping, with holes being largely in the Te 5p bands. This scenario naturally explains incommensurate crystal structure of AuTe2, and it also suggests a possible mechanism of superconductivity. An ab initio evolutionary search for stable compounds in the Au-Te system confirms stability of AuTe2 and AuTe3 and leads to a prediction of an as yet unknown stable compound AuTe, which until now has not been synthesized. © 2018 National Academy of Sciences. All rights reserved.ACKNOWLEDGMENTS. We are grateful to G. Sawatzky, S.-W. Cheong, P. Becker, and L. Bohaty for discussions. This work was supported by the UralBranch of Russian Academy of Sciences (18-10-2-37), by the RussianFoundation of Basic Research (16-32-60070), by the Federal Agency of Scientific Organizations (“spin” AAAA-A18-118020290104-2), by the Russian Ministry of Science and High Education (02.A03.21.0006), by Russian President Council on Science (MD-916.2017.2), by the DFG (SFB 1238), and by the German Excellence Initiative. A.R.O. thanks the Russian Science Foundation (16-13-10459). V.V.R. was supported by Project 5-100 of Moscow Institute of Physics and Technology, and computations were performed on the Rurik supercomputer

Velo-Cardio-Facial Syndrome

Purpose of review: Velo-cardio-facial syndrome has emerged from obscurity to become one of the most researched disorders this past decade. It is one of the most common genetic syndromes in humans, the most common contiguous gene syndrome in humans, the most common syndrome of cleft palate, and the most common syndrome of conotruncal heart malformations. Velo-cardio-facial syndrome has an expansive phenotype, a factor reflected in the wide range of studies that cover both clinical features and molecular genetics. In this review, we cover multiple areas of research during the past year, including psychiatric disorders, neuroimaging, and the delineation of clinical features. Recent findings: The identification of candidate genes for heart anomalies, mental illness, and other clinical phenotypes has been reported in the past year with a focus on TBX1 for cardiac and craniofacial phenotypes and COMT and PRODH for psychiatric disorders. The expansive phenotype of velo-cardio-facial syndrome continues to grow with new behavioral and structural anomalies reported. Treatment issues are beginning to draw attention, although most authors continue to focus on diagnostic issues. Summary: Its high population prevalence, estimated to be as common as 1:2000 has sparked a large amount of research, as has the model the syndrome serves for identifying the causes of mental illness and learning disabilities, but it is obvious that more information is needed. Intensive scrutiny of velo-cardio-facial syndrome will undoubtedly continue for many years to come with the hope that researchers will turn more of their attention to treatment and treatment outcomes

22q11.2 Deletion Syndrome: Are Motor Deficits More Than Expected for IQ Level?

To examine motor function in children with 22q11.2 deletion syndrome (22q11.2) and a Full Scale IQ (FSIQ) comparable control group. This study was part of a prospective study of neuropsychological function in children 9 to 15 years of age with 22q11.2 and community control subjects and included children from these two populations with comparable FSIQs. Verbal IQs on the WISC-R for 40 children with 22q11.2 (88.4) and 24 community control subjects (87.2) were not different (P=.563). However, the performance IQs were (22q11.2; 81.1 vs community controls; 89.3;

Apoptosis screening of human chromosome 21 proteins reveals novel cell death regulators

The functional analysis of chromosome 21 (Chr21) proteins is of great medical relevance. This refers, in particular, to the trisomy of human Chr21, which results in Down’s syndrome, a complex developmental and neurodegenerative disease. In a previous study we analyzed 89 human Chr21 genes for the subcellular localization of their encoded proteins using a transfected-cell array technique. In the present study, the results of the follow-up investigation are presented in which 52 human Chr21 genes were over-expressed in HEK cells using the transfected-cell array platform, and the effect of this protein over-expression on the induction of apoptosis has been analyzed. We found that the over-expression of two Chr21 proteins (claudin-14 and -8) induced cell death independent of the classic caspase-mediated apoptosis. Our results strongly suggest the functional involvement of claudins in the control of the cell cycle and regulation of the cell death induction mechanism