ABSTRACT
The ability to control the properties of twisted bilayer transition metal dichalcogenides in situ makes them an ideal platform for investigating the interplay of strong correlations and geometric frustration. Of particular interest are the low energy scales, which make it possible to experimentally access both temperature and magnetic fields that are of the order of the bandwidth or the correlation scale. In this manuscript, we analyze the moiré Hubbard model, believed to describe the low energy physics of an important subclass of the twisted bilayer compounds. We establish its magnetic and the metal-insulator phase diagram for the full range of magnetic fields up to the fully spin-polarized state. We find a rich phase diagram including fully and partially polarized insulating and metallic phases of which we determine the interplay of magnetic order, Zeeman-field, and metallicity, and make connection to recent experiments.
ABSTRACT
Observation of the neutrinoless double ß decay is the only practical way to establish that neutrinos are their own antiparticles1. Because of the small masses of neutrinos, the lifetime of neutrinoless double ß decay is expected to be at least ten orders of magnitude greater than the typical lifetimes of natural radioactive chains, which can mimic the experimental signature of neutrinoless double ß decay2. The most robust identification of neutrinoless double ß decay requires the definition of a signature signal-such as the observation of the daughter atom in the decay-that cannot be generated by radioactive backgrounds, as well as excellent energy resolution. In particular, the neutrinoless double ß decay of 136Xe could be established by detecting the daughter atom, 136Ba2+, in its doubly ionized state3-8. Here we demonstrate an important step towards a 'barium-tagging' experiment, which identifies double ß decay through the detection of a single Ba2+ ion. We propose a fluorescent bicolour indicator as the core of a sensor that can detect single Ba2+ ions in a high-pressure xenon gas detector. In a sensor made of a monolayer of such indicators, the Ba2+ dication would be captured by one of the molecules and generate a Ba2+-coordinated species with distinct photophysical properties. The presence of such a single Ba2+-coordinated indicator would be revealed by its response to repeated interrogation with a laser system, enabling the development of a sensor able to detect single Ba2+ ions in high-pressure xenon gas detectors for barium-tagging experiments.
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We present simulations of stochastic fluid dynamics in the vicinity of a critical endpoint belonging to the universality class of the Ising model. This study is motivated by the challenge of modeling the dynamics of critical fluctuations near a conjectured critical endpoint in the phase diagram of quantum chromodynamics (QCD). We focus on the interaction of shear modes with a conserved scalar density, which is known as model H. We show that the observed dynamical scaling behavior depends on the correlation length and the shear viscosity of the fluid. As the correlation length is increased or the viscosity is decreased we observe a crossover from the dynamical exponent of critical diffusion, z≃4, to the expected scaling exponent of model H, z≃3. We use our method to investigate the time-dependent correlation function of non-Gaussian moments M^{n}(t) of the order parameter. We find that the relaxation time depends in a nontrivial manner on the power n.
ABSTRACT
We introduce a spin-symmetry-broken extension of the connected determinant algorithm [Riccardo Rossi, Determinant diagrammatic Monte Carlo algorithm in the thermodynamic limit, Phys. Rev. Lett. 119, 045701 (2017).PRLTAO0031-900710.1103/PhysRevLett.119.045701]. The resulting systematic perturbative expansions around an antiferromagnetic state allow for numerically exact calculations directly inside a magnetically ordered phase. We show new precise results for the magnetic phase diagram and thermodynamics of the three-dimensional cubic Hubbard model at half-filling. With detailed computations of the order parameter in the low to intermediate-coupling regime, we establish the Néel phase boundary. The critical behavior in its vicinity is shown to be compatible with the O(3) Heisenberg universality class. By determining the evolution of the entropy with decreasing temperature through the phase transition we identify the different physical regimes at U/t=4. We provide quantitative results for several thermodynamic quantities deep inside the antiferromagnetic dome up to large interaction strengths and investigate the crossover between the Slater and Heisenberg regimes.
ABSTRACT
Gray et al.'s (2003) Sexual Fantasy Questionnaire (SFQ) is becoming an increasingly used self-report measure of sexual fantasy use. The current study analyzed the factorial structure and construct validity of the behavioral items of the SFQ using a nomological network of other sexuality-related measures in a large German-speaking sample (N = 846). Participants' (27.7% females) mean age was 30.8 years (SD = 11.0). Exploratory factor analysis revealed a 65-item scale comprising five-factors, which were termed: normophilic sexual fantasies, sexualized aggression, sexualized submission, submissive courtship, and bodily functions. This German version of the SFQ was found to have high construct validity indicated by its association with other related constructs. Based on these results, we argue that the SFQ is a valid self-report measure that can be used in both research and clinical practice (foremost the factors sexualized aggression and sexualized submission). Suggestions for future research are discussed in light of the results and the study's limitations.
Subject(s)
Fantasy , Sexual Behavior , Humans , Female , Adult , Male , Surveys and Questionnaires/standards , Sexual Behavior/psychology , Factor Analysis, Statistical , Reproducibility of Results , Germany , Middle Aged , Psychometrics , Adolescent , Young Adult , Self Report/standardsABSTRACT
BACKGROUND: There are conflicting data on a potential association between obesity and atopic dermatitis (AD). The purpose of this study was to investigate the relationship between obesity and AD disease severity. METHODS: Patients from the TREATgermany registry cohort were divided into three groups according to their body mass index (BMI). Due to low numbers, underweight patients (BMI <18.5 kg/m2) were excluded from the analysis. Physician- and patient-reported disease severity scores as well as additional phenotypic characteristics were evaluated for association with BMI. Generalized linear mixed models and multinomial logit models, respectively, were applied to investigate the association of BMI, age, sex and current systemic AD treatment with disease severity. RESULTS: This study encompassed 1416 patients, of which 234 (16.5%) were obese (BMI ≥30 kg/m2). Obesity was associated with lower educational background and smoking. Otherwise, obese and non-obese AD patients had similar baseline characteristics. Increased BMI was associated with higher oSCORAD (adjusted ß: 1.24, 95% CI: 1.05-1.46, p = 0.013) and Patient-oriented eczema measure (POEM) (adjusted ß: 1.09, 95% CI: 1.01-1.17, p = 0.038). However, the absolute difference in the overall oSCORAD was small between obese and non-obese AD patients (Δ oSCORAD = 2.5). Allergic comorbidity was comparable between all three groups, with the exception of asthma which was more pronounced in obese patients (p < 0.001). DISCUSSION: In this large and well-characterized AD patient cohort, obesity is significantly associated with physician- and patient-assessed measures of AD disease severity. However, the corresponding effect sizes were low and of questionable clinical relevance. The overall prevalence of obesity among the German AD patients was lower than in studies on other AD cohorts from different countries, which confirms previous research on the German population and suggests regional differences in the interdependence of AD and obesity prevalence.
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There are multiple ways to report risk scale results. Varela et al. (2014) found that Static-99R results were interpreted differently by prospective jurors based on risk level (high vs low) and an interaction between risk level and risk communication format (categorical, absolute estimate, and risk ratio). We adapted and extended Varela et al.'s (2014) study using updated Static-99R norms, recruiting a population-wide sample (n = 166), and adding variables assessing the personality factors 'cognitive motivation' (i.e., need for cognition) and 'attitudinal affect' (i.e., attitudes toward sex offenders, authoritarianism). We found a main effect of risk level and no effect of either communication format or the interaction between the two. Adding the personality variables increased explained variance from 9% to 34%, suggesting risk perception may be more about the personality of the person receiving the information than the information itself. We also found an interaction between attitudes toward sex offenders and risk level. Our results suggest risk perception might be better understood if personality factors are considered, particularly attitudes toward sex offenders. Because biases/personality of the person receiving the information are unknown in real world settings we argue that sharing multiple methods for communicating risk might be best and more inclusive.
Subject(s)
Criminals , Sex Offenses , Humans , Risk Assessment/methods , Criminals/psychology , Prospective Studies , Sex Offenses/psychology , PersonalityABSTRACT
Invited for the cover of this issue are Klaus Müller-Buschbaum and co-workers at Giessen University. The image depicts an aluminium-based MOF as a novel material for the capture of iodine radioisotopes from a potential gas atmosphere exposure. Read the full text of the article at 10.1002/chem.202104171.
Subject(s)
Iodine , Cations , Humans , Iodides , MetalsABSTRACT
Eight cationic, two-dimensional metal-organic frameworks (MOFs) were synthesized in reactions of the group 13 metal halides AlBr3 , AlI3 , GaBr3 , InBr3 and InI3 with the dipyridyl ligands 1,2-di(4-pyridyl)ethylene (bpe), 1,2-di(4-pyridyl)ethane (bpa) and 4,4'-bipyridine (bipy). Seven of them follow the general formula 2 ∞ [MX2 (L)2 ]A, M=Al, In, X=Br, I, A- =[MX4 ]- , I- , I3 - , L=bipy, bpa, bpe. Thereby, the porosity of the cationic frameworks can be utilized to take up the heavy molecule iodine in gas-phase chemisorption vital for the capture of iodine radioisotopes. This is achieved by switching between I- and the polyiodide I3 - in the cavities at room temperature, including single-crystal-to-single-crystal transformation. The MOFs are 2D networks that exhibit (4,4)-topology in general or (6,3)-topology for 2 ∞ [(GaBr2 )2 (bpa)5 ][GaBr4 ]2 â bpa. The two-dimensional networks can either be arranged to an inclined interpenetration of the cationic two-dimensional networks, or to stacked networks without interpenetration. Interpenetration is accompanied by polycatenation. Due to the cationic character, the MOFs require the counter ions [MX4 ]- , I- or I3 - counter ions in their pores. Whereas the [MX4 ]- , ions are immobile, iodide allows for chemisorption. Furthermore, eight additional coordination polymers and complexes were identified and isolated that elaborate the reaction space of the herein reported syntheses.
ABSTRACT
Homoleptic, 3D coordination polymers of the formula 33 ∞ [Ln(3-PyPz)3 ] and 3 ∞ [Ln(4-PyPz)3 ], (3-PyPz)- =3-(3-pyridyl)pyrazolate anion, (4-PyPz)- =3-(4-pyridyl)pyrazolate anion, both C8 H6 N3 - , Ln=Sm, Eu, Gd, Tb, Dy, were obtained as highly luminescent frameworks by reaction of the lanthanide metals (Ln) with the aromatic heterocyclic amine ligands 3-PyPzH and 4-PyPzH. The compounds form two isotypic series of 3D coordination polymers and exhibit fair thermal stability up to 360 °C. The luminescence properties of all ten compounds were determined in the solid state, with an antenna effect through ligand-metal energy transfer leading to high efficiency of the luminescence displayed by good quantum yields of up to 74 %. The emission is mainly based on ion-specific lanthanide-dependent intra 4 f-4 f transitions for Tb3+ : green, Dy3+ : yellow, Sm3+ : orange-red, Eu3+ : red. For the Gd3+ -containing compounds, the yellow emission of ligand triplet-based phosphorescence is observed at room temperature and 77â K. Co doping of the Gd-containing frameworks with Eu3+ and Tb3+ allow further shifting of the chromaticity towards white light emission.
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Objectives: When psychotherapists encounter an older patient with depression and death wishes, especially when burdened by physical illness, they may be subject to judgmental biases. This study investigates how this group of patients with highest suicide risk may experience discrimination both on age and health status. Methods: Using a 2 × 2 [chronological age x physical health status] vignette design, psychotherapists (N = 147) were randomly presented with one of the four variants of a case describing a patient with depression and death wishes (i.e., 78 years old + poor physical health; 78 years old + normal physical health; 48 years old + poor physical health; 48 years old + normal physical health). Afterward, participants' attitudes toward the case were assessed. Results: In case of the hypothetical patient's old age and poor health status, participants did not underestimate the pathological significance of his death wishes, but nevertheless showed less optimistic treatment attitudes and less confidence in psychotherapeutic treatment. Conclusions: Psychotherapists' age bias and health bias may serve as two potentially fatal factors influencing the provision of mental health services. Clinical Implications: Psychotherapists may contribute to better mental health-care provision of older adults with depression and the prevention of late-life suicide by increasing awareness of their age and health bias.
Subject(s)
Mental Health Services , Psychotherapists , Aged , Attitude , Bias , Humans , PsychotherapyABSTRACT
Cellulose nanocrystals (CNCs) are unique, lightweight materials that possess high elastic modulus and tensile strength, making them of great interest in the formation of nanocomposite materials. However, efficient design of the composite material is essential in translating the mechanical properties of the individual CNCs into the nanocomposite film. In this work, we demonstrate the formation of structured CNC/acrylic dispersions by physical blending of the anionic CNCs with charged acrylic latex particles. By blending with large cationic latex particles, the CNCs adsorbed onto the acrylic latex surface while blending with small latex particles led to the inverse structure. Films were cast from these dispersions and the physical properties were compared with the aim of understanding the influence of the initial structure of the hybrid dispersion on the structure of the final film. A significant difference in the mechanical properties was observed based on the position of the CNCs in the initial dispersion. Adsorption of latex particles onto the CNC surface led to a random distribution of nonconnected CNCs, which contributed little to improving the Young's modulus, while adsorption of CNC onto the latex led to a honeycomb CNC network and a large increase in the Young's modulus. This work underlines the importance of particle structure on the structure and mechanical properties of nanostructured films.
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Currently, stem cell donor registries include more than 35 million potential donors worldwide to provide HLA-matched stem cell products for patients in need of an unrelated donor transplant. DKMS is a leading stem cell donor registry with more than 9 million donors from Germany, Poland, the United States, the United Kingdom, India and Chile. DKMS donors have donated hematopoietic stem cells more than 80,000 times. Many aspects of donor registry work are closely related to topics from immunogenetics or population genetics. In this two-part review article, we describe, analyse and discuss these areas of donor registry work by using the example of DKMS. Part 1 of the review gives a general overview on DKMS and includes typical donor registry activities with special focus on the HLA system: high-throughput HLA typing of potential stem cell donors, HLA haplotype frequencies and resulting matching probabilities, and donor file optimization with regard to HLA diversity.
Subject(s)
Hematopoietic Stem Cell Transplantation , Histocompatibility Testing/methods , Registries , Unrelated Donors , Chile , Genetics, Population , Germany , HLA Antigens/genetics , HLA Antigens/immunology , Haplotypes , High-Throughput Nucleotide Sequencing , Humans , Immunogenetics , India , Poland , United Kingdom , United StatesABSTRACT
DKMS is a leading stem cell donor registry with more than 9 million donors. Donor registry activities share many touch points with topics from immunogenetics or population genetics. In this two-part review article, we deal with these aspects of donor registry work by using the example of DKMS. In the second part of the review, we focus on donor typing of non-HLA genes, the impact of donor age, gender and CMV serostatus on donation probabilities, the identification of novel HLA, KIR and MIC alleles by high-throughput donor typing, the activities of the Collaborative Biobank and pharmacogenetics in the donor registry context.
Subject(s)
HLA Antigens/genetics , Registries , Stem Cells/immunology , Tissue Donors , Alleles , Blood Grouping and Crossmatching , Genotype , Hematopoietic Stem Cell Transplantation , Histocompatibility Testing , ImmunogeneticsABSTRACT
closo-Borate anions [closo-BnXn]2- are part of the most famous textbook examples of polyhedral compounds. Substantial differences in their reactivity and interactions with other compounds depending on the substituent X and cluster size n have been recognized, which favor specific closo-borates for different applications in cancer treatment, chemical synthesis, and materials science. Surprisingly, a fundamental understanding of the molecular properties underlying these differences is lacking. Here, we report our study comparing the electronic structure and reactivity of closo-borate anions [closo-BnXn]2- (X = Cl, Br, I, n = 10, 11, 12 in all combinations) in the gas phase and in solution. We investigated the free dianions and the ion pairs [nBu4N]+[closo-BnXn]2- by gas phase anion photoelectron spectroscopy accompanied by theoretical investigations. Strong similarities in electronic structures for n = 10 and 11 were observed, while n = 12 clusters were different. A systematic picture of the development in electronic stability along the dimension X is derived. Collision induced dissociation shows that fragmentation of the free dianions is mainly dependent on the substituent X and gives access to a large variety of boron-rich molecular ions. Fragmentation of the ion pair depends strongly on n. The results reflect the high chemical stability of clusters with n = 10 and 12, while those with n = 11 are much more prone to dissociation. We bridge our study to the condensed phase by performing comparative electrochemistry and reactivity studies on closo-borates in solution. The trends found at the molecular level are also reflected in the condensed-phase properties. We discuss how the gas phase values allow evaluation of the influence of the condensed phase on the electronic stability of closo-borates. A synthetic method via an oxidation/chlorination reaction yielding [closo-B10Cl10]2- from highly chlorinated {closo-B11} clusters is introduced, which underlines the intrinsically high reactivity of the {closo-B11} cage.
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Blow flies are important tools in forensic entomology, as they feed and develop on human bodies. This fact can be used to estimate the minimum post mortem interval (PMImin), by classifying the age of the immature stages found on corpses. The capacity to also be able to classify the age of adult flies, or even empty puparia, could increase the timeframe for a PMImin. However, the association of older developmental stages, such as adult flies or their empty cases, with a human cadaver may be challenged, as such specimens could stem from another food source. Analyzing the stable carbon (δ13C) and nitrogen (δ15N) isotopes in such specimens could be helpful here, as the isotope signatures reflect those of the food sources. We compared the δ15N and δ13C signatures of tissue from humans and 12 additional species by elemental analyzer-isotope ratio mass spectrometry (EA-IRMS). We did the same for adult flies and empty puparia of the blow fly Lucilia sericata, which were derived from juvenile stages developed on tissues from the mentioned species. The isotope signatures for the adult flies and their empty puparia linearly mirrored the isotope signatures for the respective tissues on which they developed as larvae. Results such as these are useful to indicate the flies' nutritional history, but they do not provide the same kind of evidence that a DNA analysis would. As individual dietary habits, global distribution and environmental effects can influence isotope ratios, we strongly recommend to analyzing entomological traces and muscle tissues of potential donors or for other food sources.
Subject(s)
Carbon Isotopes/analysis , Diptera/chemistry , Feeding Behavior , Nitrogen Isotopes/analysis , Postmortem Changes , Animals , Entomology , Forensic Sciences/methods , Humans , Mass Spectrometry , Muscle, Skeletal/chemistry , Pupa/chemistryABSTRACT
In forensic science, reconstructing the timing of events occurring during a criminal offense is of great importance. In some cases, the time when particular evidence was left on a crime scene is a critical matter. The ability to estimate the fingerprint age would raise the evidentiary value of fingerprints tremendously. For this purpose the most promising approach is the analysis of changes in the chemical compositions of fingerprint residues in the course of aging. The focus of our study is the identification of human specific compounds in fingerprint residues, characterized by a significant aging behavior that could analytically be used for the age determination of fingerprints in future. The first challenge is the sensitive detection of trace amounts of relevant human specific fingerprint compounds. Highly sensitive LC-MS methods were developed for the reliable structure identification of unsaturated triglycerides and their natural degradation products in order to proof the aging mechanism that takes place in fingerprint residues. Thus our results build the fundamental basis for further forensic method development and potential application in forensic investigation. Ozonolysis was found to be one of the major lipid degradation pathways in fingerprint residues in ambient air. High-resolution tandem mass spectrometry (HRMS2) was carried out to identify the ozonolysis products (TG48:0-monoozonide) formed under exposure to the highly reactive ozone in atmospheric air. The obtained products were confirmed by matrix assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI). Despite several challenges and limitations in the age estimation of fingerprints, the identification of individual degradation products of specific unsaturated lipids in aged fingerprint samples represents a significant analytical progress, resulting in a strong increase in the validity of chemical analysis of fingerprints.