Jahn-Teller versus quantum effects in the spin-orbital material LuVO3

We report on combined neutron and resonant x-ray scattering results, identifying the nature of the spin-orbital ground state and magnetic excitations in LuVO3 as driven by the orbital parameter. In particular, we distinguish between models based on orbital Peierls dimerization, taken as a signature of quantum effects in orbitals, and Jahn-Teller distortions, in favor of the latter. In order to solve this long-standing puzzle, polarized neutron beams were employed as a prerequisite in order to solve details of the magnetic structure, which allowed quantitative intensity-analysis of extended magnetic excitation data sets. The results of this detailed study enabled us to draw definite conclusions about classical vs quantum behavior of orbitals in this system and to discard the previous claims about quantum effects dominating the orbital physics of LuVO3 and similar systems.Comment: Phys. Rev. B 91, 161104(R) (2015

Machine Learning Identifies Clinical and Genetic Factors Associated With Anthracycline Cardiotoxicity in Pediatric Cancer Survivors

BackgroundDespite known clinical risk factors, predicting anthracycline cardiotoxicity remains challenging.ObjectivesThis study sought to develop a clinical and genetic risk prediction model for anthracycline cardiotoxicity in childhood cancer survivors.MethodsWe performed exome sequencing in 289 childhood cancer survivors at least 3 years from anthracycline exposure. In a nested case-control design, 183 case patients with reduced left ventricular ejection fraction despite low-dose doxorubicin (≤250 mg/m2), and 106 control patients with preserved left ventricular ejection fraction despite doxorubicin >250 mg/m2 were selected as extreme phenotypes. Rare/low-frequency variants were collapsed to identify genes differentially enriched for variants between case patients and control patients. The expression levels of 5 top-ranked genes were evaluated in human induced pluripotent stem cell-derived cardiomyocytes, and variant enrichment was confirmed in a replication cohort. Using random forest, a risk prediction model that included genetic and clinical predictors was developed.ResultsThirty-one genes were differentially enriched for variants between case patients and control patients (p -15). A risk prediction model for cardiotoxicity that included clinical and genetic factors had a higher prediction accuracy and lower misclassification rate compared to the clinical-only model. In vitro inhibition of gene-associated pathways (PI3KR2, ZNF827) provided protection from cardiotoxicity in cardiomyocytes.ConclusionsOur study identified variants in cardiac injury pathway genes that protect against cardiotoxicity and informed the development of a prediction model for delayed anthracycline cardiotoxicity, and it also provided new targets in autophagy genes for the development of cardio-protective drugs. (Preventing Cardiac Sequelae in Pediatric Cancer Survivors [PCS2]; NCT01805778)

Reply to "Comment on: 'Case for a U(1)π_\pi Quantum Spin Liquid Ground State in the Dipole-Octupole Pyrochlore Ce2Zr2O7\mathrm{Ce}_2\mathrm{Zr}_2\mathrm{O}_7' "

In his comment [arXiv:2209.03235], S. W. Lovesey argues that our analysis of neutron scattering experiments performed on Ce$_2$Zr$_2$O$_7$ is invalid. Lovesey argues that we have not properly accounted for the higher-order multipolar contributions to the magnetic scattering and that our use of pseudospin-$1/2$ operators to describe the scattering is inappropriate. In this reply, we show that the multipolar corrections discussed by Lovesey only become significant at scattering wavevectors exceeding those accessed in our experiments. This in no way contradicts or undermines our work, which never claimed a direct observation of scattering from higher-order multipoles. We further show that Lovesey's objections to our use of pseudospins are unfounded, and that the pseudospin operators are able to describe all magnetic scattering processes at the energy scale of our experiments, far below the crystal field gap. Finally, we comment on certain assumptions in Lovesey's calculations of the scattering amplitude which are inconsistent with experiment.Comment: 6 pages, 1 figur

Benzene exposure and risk of colorectal cancer by anatomical subsite in the Norwegian offshore petroleum workers cohort

Objective To investigate the association between low levels of benzene exposure (≤0.879 parts per million [ppm]-years) and risk of colorectal cancer (CRC) including its anatomical subsites. Methods Among 25,347 male workers in the Norwegian Offshore Petroleum Workers (NOPW) cohort with offshore work history (1965–1998), 455 CRC cases were diagnosed 1999–2021. We compared these with a subcohort (n = 2031) drawn from the full cohort. Work histories were linked to a previously developed industry-specific benzene job-exposure matrix (JEM). Cox regression for case-cohort analyses was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for CRC, adjusted for age, body mass index, smoking, alcohol intake, red/processed meat intake, and physical activity. Results Risks of CRC increased with increasing benzene exposure. For all CRC, the HRs (95% CI) for the most exposed [quartile 4] vs. the unexposed were 1.32 (0.96 to 1.81, [0.177–0.879 ppm-years]; p-trend = 0.085) for cumulative, 1.52 (1.11 to 2.07, [17–34 years]; p-trend = 0.032) for duration, and 1.56 (1.15 to 2.12, [0.015–0.046 ppm]; p-trend = 0.005) for average intensity of benzene exposure. For right-sided colon cancer, the association was most evident for exposure duration (HR = 2.25 (1.33 to 3.80), quartile 4 [17–34 years] vs. unexposed; p-trend = 0.007). Sensitivity analyses showed consistent associations. Conclusion This study found positive exposure-response associations between low-level benzene exposure and CRC risk in offshore petroleum workers. These findings add to emerging evidence that benzene can be associated with solid tumours including lung and bladder, which potentially has important occupational and public health implications.publishedVersio

Children's very low food security is associated with increased dietary intakes in energy, fat, and added sugar among Mexican-origin children (6-11 y) in Texas border Colonias

<p>Abstract</p> <p>Background</p> <p>Food insecurity among Mexican-origin and Hispanic households is a critical nutritional health issue of national importance. At the same time, nutrition-related health conditions, such as obesity and type 2 diabetes, are increasing in Mexican-origin youth. Risk factors for obesity and type 2 diabetes are more common in Mexican-origin children and include increased intakes of energy-dense and nutrient-poor foods. This study assessed the relationship between children's experience of food insecurity and nutrient intake from food and beverages among Mexican-origin children (age 6-11 y) who resided in Texas border <it>colonias</it>.</p> <p>Methods</p> <p>Baseline data from 50 Mexican-origin children were collected in the home by trained <it>promotora</it>-researchers. All survey (demographics and nine-item child food security measure) and 24-hour dietary recall data were collected in Spanish. Dietary data were collected in person on three occasions using a multiple-pass approach; nutrient intakes were calculated with NDS-R software. Separate multiple regression models were individually fitted for total energy, protein, dietary fiber, calcium, vitamin D, potassium, sodium, Vitamin C, and percentage of calories from fat and added sugars.</p> <p>Results</p> <p>Thirty-two children (64%) reported low or very low food security. Few children met the recommendations for calcium, dietary fiber, and sodium; and none for potassium or vitamin D. Weekend intake was lower than weekday for calcium, vitamin D, potassium, and vitamin C; and higher for percent of calories from fat. Three-day average dietary intakes of total calories, protein, and percent of calories from added sugars increased with declining food security status. Very low food security was associated with greater intakes of total energy, calcium, and percentage of calories from fat and added sugar.</p> <p>Conclusions</p> <p>This paper not only emphasizes the alarming rates of food insecurity for this Hispanic subgroup, but describes the associations for food insecurity and diet among this sample of Mexican-origin children. Child-reported food insecurity situations could serve as a screen for nutrition problems in children. Further, the National School Lunch and School Breakfast Programs, which play a major beneficial role in children's weekday intakes, may not be enough to keep pace with the nutritional needs of low and very low food secure Mexican-origin children.</p

Benzene exposure and risk of colorectal cancer by anatomical subsite in the Norwegian offshore petroleum workers cohort

OBJECTIVE: To investigate the association between low levels of benzene exposure (≤0.879 parts per million [ppm]-years) and risk of colorectal cancer (CRC) including its anatomical subsites. METHODS: Among 25,347 male workers in the Norwegian Offshore Petroleum Workers (NOPW) cohort with offshore work history (1965-1998), 455 CRC cases were diagnosed 1999-2021. We compared these with a subcohort (n = 2031) drawn from the full cohort. Work histories were linked to a previously developed industry-specific benzene job-exposure matrix (JEM). Cox regression for case-cohort analyses was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for CRC, adjusted for age, body mass index, smoking, alcohol intake, red/processed meat intake, and physical activity. RESULTS: Risks of CRC increased with increasing benzene exposure. For all CRC, the HRs (95% CI) for the most exposed [quartile 4] vs. the unexposed were 1.32 (0.96 to 1.81, [0.177-0.879 ppm-years]; p-trend = 0.085) for cumulative, 1.52 (1.11 to 2.07, [17-34 years]; p-trend = 0.032) for duration, and 1.56 (1.15 to 2.12, [0.015-0.046 ppm]; p-trend = 0.005) for average intensity of benzene exposure. For right-sided colon cancer, the association was most evident for exposure duration (HR = 2.25 (1.33 to 3.80), quartile 4 [17-34 years] vs. unexposed; p-trend = 0.007). Sensitivity analyses showed consistent associations. CONCLUSION: This study found positive exposure-response associations between low-level benzene exposure and CRC risk in offshore petroleum workers. These findings add to emerging evidence that benzene can be associated with solid tumours including lung and bladder, which potentially has important occupational and public health implications

Case for a U⁡(1)� Quantum Spin Liquid Ground State in the Dipole-Octupole Pyrochlore Ce2⁢Zr2⁢O7

International audienceThe Ce 3þ pseudospin-1=2 degrees of freedom in the pyrochlore magnet Ce 2 Zr 2 O 7 are known to possess dipole-octupole character, making it a candidate for novel quantum spin liquid ground states at low temperatures. We report new polarized neutron diffraction at low temperatures, as well as heat capacity (C p) measurements on single crystal Ce 2 Zr 2 O 7. The former bears both similarities and differences with that measured from the canonical dipolar spin ice compound Ho 2 Ti 2 O 7 , while the latter rises sharply at low temperatures, initially plateauing near 0.08 K, before falling off toward a high temperature zero beyond 3 K. Above ∼ 0.5 K, the C p dataset can be fit to the results of a quantum numerical linked cluster calculation, carried out to fourth order, that allows estimates for the terms in the near-neighbor XYZ Hamiltonian expected for such dipole-octupole pyrochlore systems. Fits of the same theory to the temperature dependence of the magnetic susceptibility and unpolarized neutron scattering complement this analysis. A comparison between the resulting best-fit numerical linked cluster calculation and the polarized neutron diffraction shows both agreement and discrepancies, mostly in the form of zone-boundary diffuse scattering in the non-spin-flip channel, which are attributed to interactions beyond near neighbors. The lack of an observed thermodynamic anomaly and the constraints on the near-neighbor XYZ Hamiltonian suggest that Ce 2 Zr 2 O 7 realizes a Uð1Þ π quantum spin liquid state at low temperatures, and one that likely resides near the boundary between dipolar and octupolar character

The use of ultrasound in endemic Burkitt lymphoma in Cameroon

Background: As ultrasound (US) has become more widely available in sub-Saharan Africa, emerging evidence suggests that the prevalence of abdominal disease in endemic Burkitt lymphoma (eBL) is higher than previous estimates. This retrospective chart review was designed to assess: (1) abdominal US utilisation, (2) the incidence of abdominal disease at diagnosis, (3) correlation of extent of disease at diagnosis with overall and event-free survival (EFS). Procedure: The charts of 95 consecutive children with eBL diagnosed between April 2006 and 2008 and treated according to the Malawi 2002/03 protocol at the Banso Baptist Hospital in Cameroon were examined for demographics, clinical presentation, diagnostic workup and outcome. Analysis was performed using descriptive statistics, Z-tests and Student's t-tests. Results: Fifty of 95 presumptive eBL patients (52.7%) had fine needle aspirate (FNA) confirmation of their tumours. Ninety-four of 95 had an US at diagnosis. US was superior to clinical exam in demonstrating abdominal disease (P<0.001). There was no significant difference between the rates of jaw (73%) and abdominal disease (82%) identified by US at diagnosis. EFS among patients whose disease was upgraded by US (64%) was better that of the patients with clinically diagnosed stage 3 disease. Conclusions: We demonstrate that US provides more accurate staging of eBL than clinical examination. Abdominal involvement is more common than previously reported and appears to be as frequent as disease of the jaw at presentation. Further study should determine if more accurate staging with US is useful in risk-stratifying treatment. © 2011 Wiley Periodicals, Inc