Transverse field effects on the competition between antiferromagnetic and cluster spin-glass phases

We investigate a disordered cluster Ising antiferromagnet in the presence of a transverse field. By adopting a replica cluster mean-field framework, we analyze the role of quantum fluctuations in a model with competing short-range antiferromagnetic and intercluster disordered interactions. The model exhibits paramagnetic (PM), antiferromagnetic (AF), and cluster spin-glass (CSG) phases, which are separated by thermal and quantum phase transitions. A scenario of strong competition between AF and CSG unveils a number of interesting phenomena induced by quantum fluctuations, including a quantum PM state and quantum driven criticality. The latter occurs when the thermally driven PM-AF discontinuous phase transition becomes continuous at strong transverse fields. Analogous phenomena have been reported in a number of systems, but a description of underlying mechanisms is still required. Our results indicate that quantum driven criticality can be found in a highly competitive regime of disordered antiferromagnets, which is in consonance with recent findings in spin models with competing interactions.

Probing the Effects of Strong Electromagnetic Fields with Charge-Dependent Directed Flow in Pb-Pb Collisions at the LHC

The first measurement at the LHC of charge-dependent directed flow (v_{1}) relative to the spectator plane is presented for Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV. Results are reported for charged hadrons and D^{0} mesons for the transverse momentum intervals p_{T}>0.2  GeV/c and 3<p_{T}<6  GeV/c in the 5%-40% and 10%-40% centrality classes, respectively. The difference between the positively and negatively charged hadron v_{1} has a positive slope as a function of pseudorapidity η, dΔv_{1}/dη=[1.68±0.49(stat)±0.41(syst)]×10^{-4}. The same measurement for D^{0} and D[over ¯]^{0} mesons yields a positive value dΔv_{1}/dη=[4.9±1.7(stat)±0.6(syst)]×10^{-1}, which is about 3 orders of magnitude larger than the one of the charged hadrons. These measurements can provide new insights into the effects of the strong electromagnetic field and the initial tilt of matter created in noncentral heavy ion collisions on the dynamics of light (u, d, and s) and heavy (c) quarks. The large difference between the observed Δv_{1} of charged hadrons and D^{0} mesons may reflect different sensitivity of the charm and light quarks to the early time dynamics of a heavy ion collision. These observations challenge some recent theoretical calculations, which predicted a negative and an order of magnitude smaller value of dΔv_{1}/dη for both light flavor and charmed hadrons.

Evidence of Spin-Orbital Angular Momentum Interactions in Relativistic Heavy-Ion Collisions

The first evidence of spin alignment of vector mesons (K^{*0} and ϕ) in heavy-ion collisions at the Large Hadron Collider (LHC) is reported. The spin density matrix element ρ_{00} is measured at midrapidity (|y|<0.5) in Pb-Pb collisions at a center-of-mass energy (sqrt[s_{NN}]) of 2.76 TeV with the ALICE detector. ρ_{00} values are found to be less than 1/3 (1/3 implies no spin alignment) at low transverse momentum (p_{T}<2  GeV/c) for K^{*0} and ϕ at a level of 3σ and 2σ, respectively. No significant spin alignment is observed for the K_{S}^{0} meson (spin=0) in Pb-Pb collisions and for the vector mesons in pp collisions. The measured spin alignment is unexpectedly large but qualitatively consistent with the expectation from models which attribute it to a polarization of quarks in the presence of angular momentum in heavy-ion collisions and a subsequent hadronization by the process of recombination.

Anti-BP180 autoantibody levels at diagnosis correlate with 1-year mortality rates in patients with bullous pemphigoid

BACKGROUND

Bullous pemphigoid (BP) is the most frequent autoimmune blistering disease mainly affecting elderly patients. Among several published risk factors, a recent post hoc analysis linked anti-BP180 autoantibodies (AABs) to fatal outcomes in BP. To date, this finding has not been confirmed independently.

OBJECTIVE

To investigate the potential of anti-BP180-AAB levels as a marker of prognosis and to identify a cut-off level indicative of an increased risk for early death. Secondly, to characterize parameters associated with mortality.

METHODS

Retrospective, single-centre study of BP patients diagnosed between 2001 and 2012. Analyses included epidemiological and patient- and disease-specific characteristics as well as immunological parameters at diagnosis and during follow-up. Standardized mortality ratios as well as uni- and multivariate regression analyses were calculated.

RESULTS

One hundred patients (56 women, 44 men) with a median age of 81 years (interquartile range 74-86) were followed up for a median of 775 days (interquartile range 162-1617). One-year mortality rates were 25.0% implying a 2.4-fold increased risk of death compared with the general population. High anti-BP180 autoantibody levels at diagnosis (CI₉₅ 1.30-2.89; P = 0.001), dementia (CI₉₅ 1.13-6.72; P =0.03), length of hospitalization (CI₉₅ 1.16-2.41; P = 0.01) and age (CI₉₅ 1.23-4.19; P = 0.009) correlated significantly with 1-year mortality. BP180-AAB concentrations of ≥61 U/mL characterized a subgroup of patients with a particular higher risk for early death compared with the general population (CI₉₅ 1.81-3.81; P < 0.0001).

CONCLUSION

In bullous pemphigoid, serum concentrations of BP180 autoantibodies at diagnosis could help to identify patients at risk for death within the first year after diagnosis (cut-off value 61 U/mL).

Micro-Scale Device-An Alternative Route for Studying the Intrinsic Properties of Solid-State Materials: The Case of Semiconducting TaGeIr

An efficient application of a material is only possible if we know its physical and chemical properties, which is frequently obstructed by the presence of micro- or macroscopic inclusions of secondary phases. While sometimes a sophisticated synthesis route can address this issue, often obtaining pure material is not possible. One example is TaGeIr, which has highly sample-dependent properties resulting from the presence of several impurity phases, which influence electronic transport in the material. The effect of these minority phases was avoided by manufacturing, with the help of focused-ion-beam, a μm-scale device containing only one phase-TaGeIr. This work provides evidence for intrinsic semiconducting behavior of TaGeIr and serves as an example of selective single-domain device manufacturing. This approach gives a unique access to the properties of compounds that cannot be synthesized in single-phase form, sparing costly and time-consuming synthesis efforts.

Clitoral reduction: Technical note

Clitoral hypertrophy is a rare genital malformation that can be congenital or acquired. In congenital forms, the most common cause is adrenal hyperplasia. The acquired forms are caused by endocrinological diseases, benign tumours or cysts. Idiopathic clitoral hypertrophies can be detected after the elimination of secondary causes. A complete assessment is needed to treat the origin of clitoridomegaly. The hypertrophy is often increased or unmasked during sexual arousal with the appearance of a true vulvar appendage in erection. It is often accompanied by a hypertrophy of the clitoral hood and can cause psychological suffering with an impact on the quality of sexual life. When the cause of clitoral hypertrophy is diagnosed, treated or stabilized, the plastic surgeon may be called upon for surgical correction. Reconstructive surgery in this area has evolved considerably since the historical clitoral amputations which led to the current technique of partial resection with sparing the dorsal neurovascular pedicle of the clitoris as described by Professor Paniel. We propose a modified conservative technique to treat clitoral hypertrophy and the clitoral hood and present two clinical cases: ventral reduction clitoridoplasty with preservation of the neurovascular pedicle associated with a chevron plasty of the clitoral hood and a lipofilling of the labia majora. The postoperative follow-up is simple with reports of great satisfaction from patients regarding their quality of life.

Hepatocellular Carcinoma Surveillance in a Cohort of Chronic Hepatitis C Virus-Infected Patients with Cirrhosis

BACKGROUND

Six-monthly hepatocellular carcinoma (HCC) screening in cirrhotic patients has been recommended since 2011. HCC prognosis is associated with diagnosis at an early stage. We examined the prevalence and correlates of 6-monthly HCC surveillance in a cohort of HCV-infected cirrhotic patients.

METHODS

Data were obtained from the medical records of patients receiving care from four hospitals between January 2011 and December 2016. Frequencies and logistic regression were conducted.

RESULTS

Of 2,933 HCV-infected cirrhotic patients, most were ≥ 60 years old (68.5%), male (62.2%), White (65.8%), and had compensated cirrhosis (74.2%). The median follow-up period was 3.5 years. Among these patients, 10.9% were consistently screened 6 monthly and 21.4% were never screened. Patients with a longer history of cirrhosis (AOR = 0.86, 95% CI = 0.80-0.93) were less likely to be screened 6 monthly while decompensated cirrhotic patients (AOR = 1.39, 95% CI = 1.06-1.81) and cirrhotic patients between 18 and 44 years (AOR = 2.01, 95% CI = 1.07-3.74) were more likely to be screened 6 monthly compared to compensated cirrhotic patients and patients 60 years and older respectively. There were no significant differences by race, gender, or insurance type.

CONCLUSION

The prevalence of consistent HCC surveillance remains low despite formalized recommendations. One in five patients was never surveilled. Patients with a longer history of cirrhosis were less likely to be surveilled consistently despite their greater HCC risk. Improving providers' knowledge about current HCC surveillance guidelines, educating patients about the benefits of consistent HCC surveillance, and systemic interventions like clinical reminders and standing HCC surveillance protocols can improve guideline-concordant surveillance in clinical practice.

EndoPredict® in early hormone receptor-positive, HER2-negative breast cancer

Purpose

Evaluating consecutive early breast cancer patients, we analyzed both the impact of EndoPredict^® on clinical decisions as well as clinico-pathological factors influencing the decision to perform this gene expression test.

Methods

Hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (HER2)-negative early breast cancer patients treated between 2011 and 2016 were included in this study to investigate the role of EndoPredict^® (EPclin) in the treatment of early breast cancer. A main study aim was to analyze the changes in therapy recommendations with and without EPclin. In addition, the impact of clinico-pathological parameters for the decision to perform EPclin was examined by Pearson's chi-squared test (χ²-test) and Fisher's exact test as well as univariate and multivariate logistic regressions.

Results

In a cohort of 869 consecutive early HR-positive, HER-negative breast cancer patients, EPclin was utilized in 156 (18.0%) patients. EPclin led to changes in therapy recommendations in 33.3% (n = 52), with both therapy escalation in 19.2% (n = 30) and de-escalation in 14.1% (n = 22). The clinico-pathological factors influencing the use of EPclin were age (P < 0.001, odds ratio [OR] 0.498), tumor size (P = 0.011, OR 0.071), nodal status (P = 0.021, OR 1.674), histological grade (P = 0.043, OR 0.432), and Ki-67 (P < 0.001, OR 3.599).

Conclusions

EPclin led to a change in therapy recommendations in one third of the patients. Clinico-pathological parameters such as younger age, smaller tumor size, positive nodal status, intermediate histological grade and intermediate Ki-67 had a significant influence on the use of EndoPredict^®.

Electronic supplementary material

The online version of this article (10.1007/s10549-020-05688-1) contains supplementary material, which is available to authorized users.

Comparative Neuropsychiatry: White Matter Abnormalities in Children and Adolescents with Schizophrenia, Bipolar Affective Disorder, and Obsessive-Compulsive Disorder

Background:

There is considerable evidence that white matter abnormalities play a key role in the pathogenesis of a number of major psychiatric disorders, including schizophrenia, bipolar affective disorder, and obsessive-compulsive disorder. Few studies, however, have compared white matter abnormalities early in the course of the illness.

Methods:

A total of 102 children and adolescents participated in the study, including 43 with early-onset schizophrenia, 13 with early-onset bipolar affective disorder, 17 with obsessive-compulsive disorder, and 29 healthy controls. Diffusion tensor imaging scans were obtained on all children and the images were assessed for the presence of non-spatially overlapping regions of white matter differences, a novel algorithm known as the pothole approach.

Results:

Patients with early-onset schizophrenia and early-onset bipolar affective disorder had a significantly greater number of white matter potholes compared to controls, but the total number of potholes did not differ between the two groups. The volumes of the potholes were significantly larger in patients with early-onset bipolar affective disorder compared to the early-onset schizophrenia group. Children and adolescents with obsessive-compulsive disorder showed no differences in the total number of white matter potholes compared to controls.

Conclusions:

White matter abnormalities in early-onset schizophrenia and bipolar affective disorder are more global in nature, whereas children and adolescents with obsessive-compulsive disorder do not show widespread differences in FA.

Scattering Studies with Low-Energy Kaon-Proton Femtoscopy in Proton-Proton Collisions at the LHC

The study of the strength and behavior of the antikaon-nucleon (K[over ¯]N) interaction constitutes one of the key focuses of the strangeness sector in low-energy quantum chromodynamics (QCD). In this Letter a unique high-precision measurement of the strong interaction between kaons and protons, close and above the kinematic threshold, is presented. The femtoscopic measurements of the correlation function at low pair-frame relative momentum of (K^{+}p⊕K^{-}p[over ¯]) and (K^{-}p⊕K^{+}p[over ¯]) pairs measured in pp collisions at sqrt[s]=5, 7, and 13 TeV are reported. A structure observed around a relative momentum of 58  MeV/c in the measured correlation function of (K^{-}p⊕K^{+}p[over ¯]) with a significance of 4.4σ constitutes the first experimental evidence for the opening of the (K[over ¯]^{0}n⊕K^{0}n[over ¯]) isospin breaking channel due to the mass difference between charged and neutral kaons. The measured correlation functions have been compared to Jülich and Kyoto models in addition to the Coulomb potential. The high-precision data at low relative momenta presented in this work prove femtoscopy to be a powerful complementary tool to scattering experiments and provide new constraints above the K[over ¯]N threshold for low-energy QCD chiral models.

Single-particle imaging by x-ray free-electron lasers-How many snapshots are needed?

X-ray free-electron lasers (XFELs) open the possibility of obtaining diffraction information from a single biological macromolecule. This is because XFELs can generate extremely intense x-ray pulses that are so short that diffraction data can be collected before the sample is destroyed. By collecting a sufficient number of single-particle diffraction patterns, the three-dimensional electron density of a molecule can be reconstructed ab initio. The quality of the reconstruction depends largely on the number of patterns collected at the experiment. This paper provides an estimate of the number of diffraction patterns required to reconstruct the electron density at a targeted spatial resolution. This estimate is verified by simulations for realistic x-ray fluences, repetition rates, and experimental conditions available at modern XFELs. Employing the bacterial phytochrome as a model system, we demonstrate that sub-nanometer resolution is within reach.

Extended induction chemotherapy does not improve the outcome for high-risk neuroblastoma patients: results of the randomized open-label GPOH trial NB2004-HR

BACKGROUND

Long-term survival of high-risk neuroblastoma patients is still below 50% despite intensive multimodal treatment. This trial aimed to address whether the addition of two topotecan-containing chemotherapy courses compared to standard induction therapy improves event-free survival (EFS) of these patients.

PATIENTS AND METHODS

An open-label, multicenter, prospective randomized controlled trial was carried out at 58 hospitals in Germany and Switzerland. Patients aged 1-21 years with stage 4 neuroblastoma and patients aged 6 months to 21 years with MYCN-amplified tumors were eligible. The primary endpoint was EFS. Patients were randomly assigned to standard induction therapy with six chemotherapy courses or to experimental induction chemotherapy starting with two additional courses of topotecan, cyclophosphamide, and etoposide followed by standard induction chemotherapy (eight courses in total). After induction chemotherapy, all patients received high-dose chemotherapy with autologous hematopoietic stem cell rescue and isotretinoin for consolidation. Radiotherapy was applied to patients with active tumors at the end of induction chemotherapy.

RESULTS

Of 536 patients enrolled in the trial, 422 were randomly assigned to the control arm (n = 211) and the experimental arm (n = 211); the median follow-up time was 3.32 years (interquartile range 1.65-5.92). At data lock, the 3-year EFS of experimental and control patients was 34% and 32% [95% confidence Interval (CI) 28% to 40% and 26% to 38%; P = 0.258], respectively. Similarly, the 3-year overall survival of the patients did not differ [54% and 48% (95% CI 46% to 62% and 40% to 56%), respectively; P = 0.558]. The response to induction chemotherapy was not different between the arms. The median number of non-fatal toxicities per patient was higher in the experimental group while the median number of toxicities per chemotherapy course was not different.

CONCLUSION

While the burden for the patients was increased by prolonging the induction chemotherapy and the toxicity, the addition of two topotecan-containing chemotherapy courses did not improve the EFS of high-risk neuroblastoma patients and thus cannot be recommended. CLINICAL TRIALS.

GOV NUMBER

NCT number 03042429.

Field-induced glassy state in disordered cluster antiferromagnets

We investigate the role of antiferromagnetic spin clusters on the glassiness induced by uniform and random fields. We consider an antiferromagnetic disordered model that is treated within the replica method, resulting in an effective single-cluster problem. Our results show that regimes of weak and intermediate disorder are suitable for highly unusual phenomena. For the case of a uniform field, cluster polarization can favor a cluster spin-glass state, i.e. the magnetic field increases the freezing temperature at intermediate disorders. In addition, random fields introduce local perturbations that allow uncompensated cluster states, supporting cluster freezing even at very weak disorders. The theoretical framework presented here can be useful for the understanding of phenomena observed in magnetic glassy systems that have spin clusters as building blocks instead of individual spins. In particular, we suggest that our results can help to explain the magnetic behaviour of the rare earth TbIn_0.99Mn_0.01O₃, which has been recently proposed to be composed of antiferromagnetic clusters, presenting a field-induced increase of the freezing temperature.