Multi- k spin ordering in CaFe₃Ti₄O₁₂ stabilized by spin-orbit coupling and further-neighbor exchange

Orthogonal spin ordering is rarely observed in magnetic oxides because nearest-neighbor symmetric Heisenberg superexchange interactions usually dominate. We have discovered that in the quadruple perovskite CaFe₃Ti₄O₁₂, where only the S = 2 Fe²⁺ ion is magnetic, long-range magnetic order consisting of an unusual arrangement of three interpenetrating orthogonal sublattices is stabilized. Each magnetic sublattice corresponds to a set of FeO₄ square planes sharing a common orientation. This multi-k magnetic spin ordering is the result of fourth-neighbor spin couplings with a strong easy-axis anisotropy. In an applied magnetic field, each sublattice tends towards ferromagnetic alignment, but remains polarized by internal magnetic fields generated by the others, thus stabilizing in a noncollinear canted ferromagnetic structure. CaFe₃Ti₄O₁₂ provides a rare example of how nontrivial long-range spin order can arise when near-neighbor Heisenberg superexchange is quenched

Telomere Length Shows No Association with BRCA1 and BRCA2 Mutation Status

This study aimed to determine whether telomere length (TL) is a marker of cancer risk or genetic status amongst two cohorts of BRCA1 and BRCA2 mutation carriers and controls. The first group was a prospective set of 665 male BRCA1/2 mutation carriers and controls (mean age 53 years), all healthy at time of enrolment and blood donation, 21 of whom have developed prostate cancer whilst on study. The second group consisted of 283 female BRCA1/2 mutation carriers and controls (mean age 48 years), half of whom had been diagnosed with breast cancer prior to enrolment. TL was quantified by qPCR from DNA extracted from peripheral blood lymphocytes. Weighted and unweighted Cox regressions and linear regression analyses were used to assess whether TL was associated with BRCA1/2 mutation status or cancer risk. We found no evidence for association between developing cancer or being a BRCA1 or BRCA2 mutation carrier and telomere length. It is the first study investigating TL in a cohort of genetically predisposed males and although TL and BRCA status was previously studied in females our results don't support the previous finding of association between hereditary breast cancer and shorter TL

Parathyroid adenoma apoplexy as a temporary solution of primary hyperparathyroidism: a case report

<p>Abstract</p> <p>Introduction</p> <p>The natural history of patients with spontaneous parathyroid necrosis is unknown. In this case report we describe the clinical course, laboratory, radiographic, bone densitometry tests, parathyroid ultrasonography and scintigraphy examinations of a patient performed over a period of eight years after she first presented with a sudden episode of spontaneous resolution of primary hyperparathyroidism (PHPT).</p> <p>Case presentation</p> <p>A 24-year-old woman with a clinical history and laboratory and radiographic tests compatible with PHPT suffered a sudden episode of cervical pain and presented with clinical evidence of hypocalcemia. Biopsy of a cervical nodule revealed necrotic material compatible with ischemia of the parathyroid. The follow-up of the patient presented four distinct phases: the first, which lasted two years, was compatible with a period of bone hunger during which it was necessary to introduce calcitriol and calcium carbonate. During this period, the patient showed bone mass gain. The second phase was characterized by normalization of calcium and parathyroid hormone levels and its end was difficult to define. During the third phase there was a recurrence of hypercalcemia associated with elevated parathyroid hormone (PTH) levels and loss of bone mass. The last phase corresponded to the interval after parathyroidectomy, which was characterized by normalization of serum levels of calcium and PTH, as well as bone mass gain.</p> <p>Conclusion</p> <p>This case report indicates that spontaneous resolution of PHPT by adenoma necrosis is potentially temporary. Thus, in cases in which a conservative approach is chosen, clinical and laboratory follow-up is indispensable. Bone mass measurement is a useful tool in the follow-up of these cases. However, this option exposes the patient to a potential roller-coaster ride of bone mass gain and loss, whose long term consequences are still unknown.</p

Treatment-resistant major depressive disorder: Canadian expert consensus on definition and assessment

Background: Treatment-resistant depression (TRD) is a debilitating chronic mental illness that confers increased morbidity and mortality, decreases the quality of life, impairs occupational, social, and offspring development, and translates into increased costs on the healthcare system. The goal of this study is to reach an agreement on the concept, definition, staging model, and assessment of TRD. Methods: This study involved a review of the literature and a modified Delphi process for consensus agreement. The Appraisal of Guidelines for Research & Evaluation II guidelines were followed for the literature appraisal. Literature was assessed for quality and strength of evidence using the grading, assessment, development, and evaluations system. Canadian national experts in depression were invited for the modified Delphi process based on their prior clinical and research expertize. Survey items were considered to have reached a consensus if 80% or more of the experts supported the statement. Results: Fourteen Canadian experts were recruited for three rounds of surveys to reach a consensus on a total of 27 items. Experts agreed that a dimensional definition for treatment resistance was a useful concept to describe the heterogeneity of this illness. The use of staging models and clinical scales was recommended in evaluating depression. Risk factors and comorbidities were identified as potential predictors for treatment resistance. Conclusions: TRD is a meaningful concept both for clinical practice and research. An operational definition for TRD will allow for opportunities to improve the validity of predictors and therapeutic options for these patients

USE OF SPECIES OF URBAN TREES IN ENVIRONMENTAL POLLUTION BIOMONITORING

O biomonitoramento consiste na utiliza\ue7\ue3o de organismos vivos para apontar poss\uedveis polui\ue7\uf5es ambientais. Objetivou-se neste estudo avaliar a influ\ueancia da intensidade do tr\ue1fego urbano na disponibilidade de elementos e s\uf3lidos em suspens\ue3o, bem como identificar a potencialidade no ac\ufamulo e reten\ue7\ue3o das subst\ue2ncias em diferentes esp\ue9cies arb\uf3reas, utilizando suas folhas como biomonitores passivos e de acumula\ue7\ue3o. Como amostras utilizaram-se folhas de \ue1rvores coletadas em duas \ue1reas no munic\uedpio de Vit\uf3ria da Conquista - BA: com tr\ue2nsito de ve\uedculos e atividades antr\uf3picas moderadas; e em uma zona de maior tr\ue1fego e com atividades intensas. Foram determinados o material particulado (MP) depositado nas folhas pelo m\ue9todo gravim\ue9trico e os elementos Fe, Cu, Ni, Co e Cd por espectrometria de absor\ue7\ue3o at\uf4mica em forno de grafite (EAA FG). O Fe se distinguiu significativamente das demais vari\ue1veis, com concentra\ue7\uf5es superiores aos outros metais. Utilizaram-se an\ue1lises estat\uedsticas multivariadas para a interpreta\ue7\ue3o dos dados. A an\ue1lise de agrupamento hier\ue1rquico separou dois grupos de acordo com a espacialidade e a an\ue1lise de componentes principais permitiu a explica\ue7\ue3o desta tend\ueancia amostral. Um grupo foi constitu\ueddo por MP, Fe e Cd, pelo fato de serem originados do desgaste dos ve\uedculos e queima de combust\uedveis f\uf3sseis. As esp\ue9cies da fam\uedlia Fabaceae apresentaram uma maior similaridade em rela\ue7\ue3o ao elemento Cu, isto, porque a atividade metab\uf3lica do Cu tem comportamento inversamente proporcional \ue0 concentra\ue7\ue3o de nitrog\ueanio. O tr\ue2nsito de ve\uedculos influiu diretamente na disponibilidade de alguns elementos t\uf3xicos e na concentra\ue7\ue3o de part\uedculas s\uf3lidas depositadas. Conclui-se que a esp\ue9cie influi no ac\ufamulo dos elementos qu\uedmicos e apresentam diferentes potenciais de capta\ue7\ue3o. A arboriza\ue7\ue3o pode ser utilizada como biomonitora passiva de acumula\ue7\ue3o.Biomonitoring is the use of living organisms to identify possible environmental pollution. The objective of this study was to evaluate the influence of intensity of urban traffic in the availability of elements and suspended solids as well as identify the potential in the accumulation and retention of substances in different tree species using its leaves as passive biomonitors and for accumulation. As samples we used tree leaves collected from two areas in the municipality of Vitoria da Conquista (BA state), with transit vehicles and moderate human activities, and in a zone of increased traffic and intense activities. We determined the particulate matter (MP) deposited in the leaves by the gravimetric method and the elements Fe, Cu, Ni, Co and Cd by atomic absorption spectrometry with graphite furnace (GF AAS). Fe was significantly distinguished from other variables, with higher concentrations than other metals. The data was interpreted by multivariate analysis. Cluster analysis separated two groups, one consisting of MP, Fe and Cd, because they are originated from the wear and tear of vehicles and burning fossil fuels. The species of the family Fabaceae showed greater similarity to Cu element, namely, because the Cu metabolic activity is inversely proportional to the concentration of nitrogen behavior. The vehicle traffic directly influenced the availability of some toxic elements and the concentration of the deposited solid particles. It is concluded that the species influences the accumulation of chemical elements and have different catchment potentials. The trees can be utilized as biomonitors which are passive of accumulation

Comparison of coronary heart disease genetic assessment with conventional cardiovascular risk assessment in primary care: reflections on a feasibility study

This study assesses the feasibility of collecting genetic samples and self-reported outcome measures after cardiovascular risk assessment, and presenting the genetic test results to participants. Coronary heart disease (CHD) genetic tests are increasingly available through direct-to-consumer marketing, but their potential clinical impact on cardiovascular risk assessment is unclear. Observational study in 10 British general practices in Central England. A total of 320 individuals, who had completed conventional cardiovascular risk assessment, were offered CHD genetic test, with follow-up outcome questionnaire at eight months for lifestyle change and State-Trait Anxiety. A total of 119 (37%) participants returned genetic test specimens, with over a third reporting family history of CHD in a specified relative; 79 (66.4%) were categorized above-average risk on conventional cardiovascular risk assessment, 65 of whom (82.3%) were only average risk on genetic assessment. The dietary fat questionnaire was poorly completed while study participation was not associated with increased anxiety (mean increase in anxiety score=2.1; 95% CI −0.1–4.3; P=0.06). As a feasibility study, over a third of individuals offered genetic testing in primary care, as part of CVD risk assessment, took up the offer. Although intervention did not appear to increase anxiety, this needs further evaluation. To improve generalizability and effect size, future studies should actively engage individuals from wider socio-economic backgrounds who may not have already contemplated lifestyle change. The current research suggests general practitioners will face the clinical challenge of patients presenting with direct-to-consumer genetic results that are inconsistent with conventional cardiovascular risk assessment

Anoxia- and hypoxia-induced expression of LDH-A* in the Amazon Oscar, Astronotus crassipinis

Adaptation or acclimation to hypoxia occurs via the modulation of physiologically relevant genes, such as erythropoietin, transferrin, vascular endothelial growth factor, phosphofructokinase and lactate dehydrogenase A. In the present study, we have cloned, sequenced and examined the modulation of the LDH-A gene after an Amazonian fish species, Astronotus crassipinis (the Oscar), was exposed to hypoxia and anoxia. In earlier studies, we have discovered that adults of this species are extremely tolerant to hypoxia and anoxia, while the juveniles are less tolerant. Exposure of juveniles to acute hypoxia and anoxia resulted in increased LDH-A gene expression in skeletal and cardiac muscles. When exposed to graded hypoxia juveniles show decreased LDH-A expression. In adults, the levels of LDH-A mRNA did not increase in hypoxic or anoxic conditions. Our results demonstrate that, when given time for acclimation, fish at different life-stages are able to respond differently to survive hypoxic episodes

Green turtles (Chelonia mydas) foraging at Arvoredo Island in Southern Brazil: Genetic characterization and mixed stock analysis through mtDNA control region haplotypes

We analyzed mtDNA control region sequences of green turtles (Chelonia mydas) from Arvoredo Island, a foraging ground in southern Brazil, and identified eight haplotypes. Of these, CM-A8 (64%) and CM-A5 (22%) were dominant, the remainder presenting low frequencies (< 5%). Haplotype (h) and nucleotide (π) diversities were 0.5570 ± 0.0697 and 0.0021 ± 0.0016, respectively. Exact tests of differentiation and AMOVA ΦST pairwise values between the study area and eight other Atlantic foraging grounds revealed significant differences in most areas, except Ubatuba and Rocas/Noronha, in Brazil (p > 0.05). Mixed Stock Analysis, incorporating eleven Atlantic and one Mediterranean rookery as possible sources of individuals, indicated Ascension and Aves islands as the main contributing stocks to the Arvoredo aggregation (68.01% and 22.96%, respectively). These results demonstrate the extensive relationships between Arvoredo Island and other Atlantic foraging and breeding areas. Such an understanding provides a framework for establishing adequate management and conservation strategies for this endangered species