454 research outputs found
Hidden zero-temperature bicritical point in the two-dimensional anisotropic Heisenberg model: Monte Carlo simulations and proper finite-size scaling
By considering the appropriate finite-size effect, we explain the connection
between Monte Carlo simulations of two-dimensional anisotropic Heisenberg
antiferromagnet in a field and the early renormalization group calculation for
the bicritical point in dimensions. We found that the long length
scale physics of the Monte Carlo simulations is indeed captured by the
anisotropic nonlinear model. Our Monte Carlo data and analysis confirm
that the bicritical point in two dimensions is Heisenberg-like and occurs at
T=0, therefore the uncertainty in the phase diagram of this model is removed.Comment: 10 pages, 11 figure
Predicting delirium in older non-intensive care unit inpatients: development and validation of the DELIrium risK Tool (DELIKT)
BACKGROUND
Effective delirium prevention could benefit from automatic risk stratification of older inpatients using routinely collected clinical data.
AIM
Primary aim was to develop and validate a delirium prediction model (DELIKT) suitable for implementation in hospitals. Secondary aim was to select an anticholinergic burden scale as a predictor.
METHOD
We used one cohort for model development and another for validation with electronically available data collected within the first 24 h of admission. Included were patients aged ≥ 65, hospitalised ≥ 48 h with no stay > 24 h in an intensive care unit. Predictors, such as administrative and laboratory variables or an anticholinergic burden scale, were selected using a combination of feature selection filter method and forward/backward selection. The final model was based on logistic regression and the DELIKT was derived from the β-coefficients. We report the following performance measures: area under the curve, sensitivity, specificity and odds ratio.
RESULTS
Both cohorts were similar and included over 10,000 patients each (mean age 77.6 ± 7.6 years) with 11% experiencing delirium. The model included nine variables: age, medical department, dementia, hemi-/paraplegia, catheterisation, potassium, creatinine, polypharmacy and the anticholinergic burden measured with the Clinician-rated Anticholinergic Scale (CrAS). The external validation yielded an AUC of 0.795. With a cut-off at 20 points in the DELIKT, we received a sensitivity of 79.7%, specificity of 62.3% and an odds ratio of 5.9 (95% CI 5.2, 6.7).
CONCLUSION
The DELIKT is a potentially automatic tool with predictors from standard care including the CrAS to identify patients at high risk for delirium
The Pulsed Neutron Beam EDM Experiment
We report on the Beam EDM experiment, which aims to employ a pulsed cold
neutron beam to search for an electric dipole moment instead of the established
use of storable ultracold neutrons. We present a brief overview of the basic
measurement concept and the current status of our proof-of-principle Ramsey
apparatus
Study of the One- and Two-Band Models for Colossal Magnetoresistive Manganites Using the Truncated Polynomial Expansion Method
Considerable progress has been recently made in the theoretical understanding
of the colossal magnetoresistance (CMR) effect in manganites. The analysis of
simple models with two competing states and a resistor network approximation to
calculate conductances has confirmed that CMR effects can be theoretically
reproduced using non-uniform clustered states. In this paper, the recently
proposed Truncated Polynomial Expansion method (TPEM) for spin-fermion systems
is tested using the double-exchange one-band, with finite Hund coupling , and two-band, with infinite , models. Two dimensional lattices
as large as 4848 are studied, far larger than those that can be handled
with standard exact diagonalization (DIAG) techniques for the fermionic sector.
The clean limit (i.e. without quenched disorder) is here analyzed in detail.
Phase diagrams are obtained, showing first-order transitions separating
ferromagnetic metallic from insulating states. A huge magnetoresistance is
found at low temperatures by including small magnetic fields, in excellent
agreement with experiments. However, at temperatures above the Curie transition
the effect is much smaller confirming that the standard finite-temperature CMR
phenomenon cannot be understood using homogeneous states. By comparing results
between the two methods, TPEM and DIAG, on small lattices, and by analyzing the
systematic behavior with increasing cluster sizes, it is concluded that the
TPEM is accurate to handle realistic manganite models on large systems. Our
results pave the way to a frontal computational attack of the colossal
magnetoresistance phenomenon using double-exchange like models, on large
clusters, and including quenched disorder.Comment: 14 pages, 17 figure
Inpatient opioid prescribing patterns and their effect on rehospitalisations: a nested case-control study using data from a Swiss public acute hospital.
AIMS OF THE STUDY
Opioid prescriptions have increased in Switzerland, even though current guidelines warn of their harms. If opioids for postoperative analgesia are not tapered before hospital discharge, patients are at risk of adverse events such as constipation, drowsiness, dependence, tolerance and withdrawal. The aim of this study was to investigate and quantify the potential association between opioids prescribed at discharge from hospital and rehospitalisation.
METHODS
We conducted a nested case-control study using routinely collected electronic health records from a Swiss public acute hospital. Cases were patients aged 65 years or older admitted between November 2014 and December 2018, with documented opioid administration on the day of discharge and rehospitalisation within 18 or 30 days after discharge. Each case was matched to five controls for age, sex, year of hospitalisation and Charlson Comorbidity Index. We calculated odds ratios for 18-day and 30-day rehospitalisation based on exposure to opioids using a conditional logistic regression adjusted for potential confounders. Secondary analyses included stratifications into morphine-equivalent doses of <50 mg, 50-89 mg and ≥90 mg, and co-prescriptions of gabapentinoids and benzodiazepines.
RESULTS
Of 22,471 included patients, 3144 rehospitalisations were identified, of which 1698 were 18-day rehospitalisations and 1446 were 30-day rehospitalisations. Documented opioid administration on the day of discharge was associated with 30-day rehospitalisation after adjustment for confounders (adjusted odds ratio 1.48; 95% CI 1.25-1.75, p 50 mg were rare.
CONCLUSIONS
Patients receiving opioids on the day of discharge were 48% more likely to be readmitted to hospital within 30 days. Clinicians should aim to discontinue opioids started in hospital before discharge if possible. Patients receiving an opioid prescription should be educated and monitored as part of opioid stewardship programmes
Mott Transition of MnO under Pressure: Comparison of Correlated Band Theories
The electronic structure, magnetic moment, and volume collapse of MnO under
pressure are obtained from four different correlated band theory methods; local
density approximation + Hubbard U (LDA+U), pseudopotential self-interaction
correction (pseudo-SIC), the hybrid functional (combined local exchange plus
Hartree-Fock exchange), and the local spin density SIC (SIC-LSD) method. Each
method treats correlation among the five Mn 3d orbitals (per spin), including
their hybridization with three O orbitals in the valence bands and their
changes with pressure. The focus is on comparison of the methods for rocksalt
MnO (neglecting the observed transition to the NiAs structure in the 90-100 GPa
range). Each method predicts a first-order volume collapse, but with variation
in the predicted volume and critical pressure. Accompanying the volume collapse
is a moment collapse, which for all methods is from high-spin to low-spin (5/2
to 1/2), not to nonmagnetic as the simplest scenario would have. The specific
manner in which the transition occurs varies considerably among the methods:
pseudo-SIC and SIC-LSD give insulator-to-metal, while LDA+U gives
insulator-to-insulator and the hybrid method gives an insulator-to-semimetal
transition. Projected densities of states above and below the transition are
presented for each of the methods and used to analyze the character of each
transition. In some cases the rhombohedral symmetry of the
antiferromagnetically ordered phase clearly influences the character of the
transition.Comment: 14 pages, 9 figures. A 7 institute collaboration, Updated versio
Influence of temperature on intra- and interspecific resource utilization within a community of lepidopteran maize stemborers
Competition or facilitation characterises intra-and interspecific interactions within communities of species that utilize the same resources. Temperature is an important factor influencing those interactions and eventual outcomes. The noctuid stemborers, Busseola fusca and Sesamia calamistis and the crambid Chilo partellus attack maize in sub-Saharan Africa. They often occur as a community of interacting species in the same field and plant at all elevations. The influence of temperature on the intra-and interspecific interactions among larvae of these species, was studied using potted maize plants exposed to varying temperatures in a greenhouse and artificial stems kept at different constant temperatures (15 degrees C, 20 degrees C, 25 degrees C and 30 degrees C) in an incubator. The experiments involved single-and multispecies infestation treatments. Survival and relative growth rates of each species were assessed. Both intra-and interspecific competitions were observed among all three species. Interspecific competition was stronger between the noctuids and the crambid than between the two noctuids. Temperature affected both survival and relative growth rates of the three species. Particularly at high temperatures, C. partellus was superior in interspecific interactions shown by higher larval survival and relative growth rates. In contrast, low temperatures favoured survival of B. fusca and S. calamistis but affected the relative growth rates of all three species. Survival and relative growth rates of B. fusca and S. calamistis in interspecific interactions did not differ significantly across temperatures. Temperature increase caused by future climate change is likely to confer an advantage on C. partellus over the noctuids in the utilization of resources (crops)
Evaluation of the association of anticholinergic burden and delirium in older hospitalised patients - A cohort study comparing 19 anticholinergic burden scales
AIMS
A recent review identified 19 anticholinergic burden scales (ABSs) but no study has yet compared the impact of all 19 ABSs on delirium. We evaluated whether a high anticholinergic burden as classified by each ABS is associated with incident delirium.
METHOD
We performed a retrospective cohort study in a Swiss tertiary teaching hospital using data from 2015-2018. Included were patients aged ≥65, hospitalised ≥48 hours with no stay >24 hours in intensive care. Delirium was defined twofold: (i) ICD-10 or CAM and (ii) ICD-10 or CAM or DOSS. Patients' cumulative anticholinergic burden score, calculated within 24 hours after admission, was classified using a binary (<3: low, ≥3: high burden) and a categorical approach (0: no, 0.5-3: low, ≥3: high burden). Association was analysed using multivariable logistic regression.
RESULTS
Over 25 000 patients (mean age 77.9 ± 7.6 years) were included. Of these, (i) 864 (3.3%) and (ii) 2770 (11.0%) developed delirium. Depending on the evaluated ABS, 4-63% of the patients were exposed to at least one anticholinergic drug. Out of 19 ABSs, (i) 14 and (ii) 16 showed a significant association with the outcomes. A patient with a high anticholinergic burden score had odds ratios (ORs) of 1.21 (95% confidence interval [CI]: 1.03-1.42) to 2.63 (95% CI: 2.28-3.03) for incident delirium compared to those with low or no burden.
CONCLUSION
A high anticholinergic burden within 24 hours after admission was significantly associated with incident delirium. Although prospective studies need to confirm these results, discontinuing or substituting drugs with a score of ≥3 at admission might be a targeted intervention to reduce incident delirium
F-18-Fluorodeoxyglucose (FDG) Positron-Emission Tomography of Echinococcus multilocularis Liver Lesions: Prospective Evaluation of its Value for Diagnosis and Follow-up during Benzimidazole Therapy
Background:: Long-term benzimidazole therapy benefits patients with non-resectable alveolar echinococcosis (AE). Methods to assess early therapeutic efficacy are lacking. Recently, AE liver lesions were reported to exhibit increased F-18-fluorodeoxyglucose (FDG) uptake in positron emission tomography (PET). To assess the value of FDG-PET for diagnosis and follow-up of AE patients. Patients/Methods:: Twenty-six consecutive patients with newly diagnosed AE were enrolled. Baseline evaluation included CT and FDG-PET. Thirteen patients (11 women; median age 50 years, range 40-76) were resected, the remaining 13 (8 women; median age 60 years, range 39-72) had non-resectable disease, were started on benzimidazoles, and CT and FDG-PET were repeated at 6, 12 and 24 months of therapy. Twelve consecutive patients with newly diagnosed cystic echinococcosis (CE) of the liver were also subjected to baseline FDG-PET. Results:: In 21/26 AE patients, baseline PET scans showed multifocally increased FDG uptake in the hepatic lesions' periphery, while liver lesions were FDG negative in 11/12 CE patients. Thus, sensitivity and specificity of FDG-PET for AE vs. CE were 81% and 92%, respectively. In 5 of 10 non-resectable patients with increased baseline FDG uptake, the intensity of uptake decreased (or disappeared) during benzimidazole therapy, in 3 by ≥2 grades within the initial 6 months. Conclusions:: FDG-PET is a sensitive and specific adjunct in the diagnosis of suspected AE and can help in differentiating AE from CE. The rapid improvement of positive PET scans with benzimidazole therapy in some patients indicates that absent FDG uptake does not necessarily reflect parasite viabilit
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