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1.
Occup Med (Lond) ; 72(1): 17-24, 2022 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-34693972

RESUMO

BACKGROUND: Anxiety and depression account for considerable cost to organizations, driven by both presenteeism (reduced performance due to attending work while ill) and absenteeism. Most research has focused on the impact of depression, with less attention given to anxiety and comorbid presentations. AIMS: To explore the cross-sectional relationship between depression and anxiety (individually and comorbidly) on workplace performance and sickness absence. METHODS: As part of a larger study to evaluate a mental health app, 4953 working Australians were recruited. Participants completed in-app assessment including demographic questions, the Patient Health Questionnaire-9, two-item Generalized Anxiety Disorder and questions from the World Health Organization Health and Work Performance Questionnaire. Cut-off scores were used to establish probable cases of depression alone, anxiety alone and comorbidity. RESULTS: Of the total sample, 7% met cut-off for depression only, 13% anxiety only, while 16% were comorbid. Those with comorbidity reported greater symptom severity, poorer work performance and more sickness absence compared to all other groups. Presenteeism and absenteeism were significantly worse in those with depression only and anxiety only compared to those with non-clinical symptom levels. Although those with depression alone tended to have poorer outcomes than the anxiety-only group, when sample prevalence rates were considered, the impact on presenteeism was comparable. CONCLUSIONS: Workplace functioning is heavily impacted by depression and anxiety both independently and where they co-occur. While comorbidity and more severe depression presentations stand out as impairing, workplace interventions should also prioritize targeting of anxiety disorders (and associated presenteeism) given their high population prevalence.


Assuntos
Absenteísmo , Depressão , Ansiedade/epidemiologia , Transtornos de Ansiedade/epidemiologia , Austrália/epidemiologia , Comorbidade , Depressão/epidemiologia , Depressão/psicologia , Humanos , Inquéritos e Questionários , Local de Trabalho/psicologia
2.
Anaesthesia ; 76 Suppl 1: 40-52, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33426663

RESUMO

Utilisation of regional anaesthesia is increasing globally; however, it remains challenging to determine the overall benefit of individual regional anaesthesia procedures. Like any peri-operative intervention, the benefit to the patient and healthcare system must outweigh any patient risk or resource implications. This review aims to identify markers of success in regional anaesthesia, categorise these into an objective framework and rationalise suggestions on how measuring outcomes in regional anaesthesia can be used to develop the widespread performance of this evolving subspecialty. This framework of measuring success of regional anaesthesia contains four pillars: patient-centred, population-centred, healthcare-centred and training-centred outcomes. Each pillar of success contains several outcomes which provide a structure for the measurement and development of regional anaesthesia success on a global scale.


Assuntos
Anestesia por Condução/normas , Anestesia por Condução/efeitos adversos , Humanos , Medição de Risco , Resultado do Tratamento
3.
J Anat ; 236(1): 132-141, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31512233

RESUMO

Placental function is essential for fetal development and establishing the foundations for lifelong health. The placental villous stroma is a connective tissue layer that supports the fetal capillaries and villous trophoblast. All the nutrients that cross the placenta must also cross the stroma, and yet little is known about this region. This study uses high-resolution three-dimensional imaging to explore the structural complexity of this region within the placental villi. Serial block-face scanning electron microscopy and confocal microscopy were used to image the placental villous stroma in three-dimensions. Transmission electron microscopy (TEM) was used to generate high resolution two-dimensional images. Stereological approaches were used to quantify volumes of stromal constituents. Three-dimensional imaging identified stromal extracellular vesicles, which constituted 3.9% of the villous stromal volume. These stromal extracellular vesicles were ovoid in shape, had a median length of 2750 nm (range 350-7730 nm) and TEM imaging confirmed that they were bounded by a lipid bilayer. Fifty-nine per cent of extracellular vesicles were in contact with a fibroblast-like stellate cell and these vesicles were significantly larger than those where no contact was observed. These stellate cells formed local networks with adherent junctions observed at contact points. This study demonstrates that the villous stroma contains extracellular macrovesicles which are considerably larger than any previously described in tissue or plasma. The size and abundance of these macrovesicles in the villous stroma highlight the diversity of extracellular vesicle biology and their roles within connective tissues.


Assuntos
Vilosidades Coriônicas/ultraestrutura , Vesículas Extracelulares/ultraestrutura , Placenta/ultraestrutura , Feminino , Humanos , Microscopia Confocal , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Placenta/citologia , Gravidez
4.
J Exp Biol ; 223(Pt 20)2020 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-32820028

RESUMO

Fundamental scaling relationships influence the physiology of vital rates, which in turn shape the ecology and evolution of organisms. For diving mammals, benefits conferred by large body size include reduced transport costs and enhanced breath-holding capacity, thereby increasing overall foraging efficiency. Rorqual whales feed by engulfing a large mass of prey-laden water at high speed and filtering it through baleen plates. However, as engulfment capacity increases with body length (engulfment volume∝body length3.57), the surface area of the baleen filter does not increase proportionally (baleen area∝body length1.82), and thus the filtration time of larger rorquals predictably increases as the baleen surface area must filter a disproportionally large amount of water. We predicted that filtration time should scale with body length to the power of 1.75 (filter time∝body length1.75). We tested this hypothesis on four rorqual species using multi-sensor tags with corresponding unoccupied aircraft systems-based body length estimates. We found that filter time scales with body length to the power of 1.79 (95% CI: 1.61-1.97). This result highlights a scale-dependent trade-off between engulfment capacity and baleen area that creates a biomechanical constraint to foraging through increased filtration time. Consequently, larger whales must target high-density prey patches commensurate to the gulp size to meet their increased energetic demands. If these optimal patches are absent, larger rorquals may experience reduced foraging efficiency compared with smaller whales if they do not match their engulfment capacity to the size of targeted prey aggregations.


Assuntos
Metabolismo Energético , Comportamento Alimentar , Animais , Fenômenos Biomecânicos , Tamanho Corporal , Baleias
5.
Nature ; 513(7519): 530-3, 2014 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-25209667

RESUMO

A quantitative understanding of sources and sinks of fixed nitrogen in low-oxygen waters is required to explain the role of oxygen-minimum zones (OMZs) in controlling the fixed nitrogen inventory of the global ocean. Apparent imbalances in geochemical nitrogen budgets have spurred numerous studies to measure the contributions of heterotrophic and autotrophic N2-producing metabolisms (denitrification and anaerobic ammonia oxidation, respectively). Recently, 'cryptic' sulphur cycling was proposed as a partial solution to the fundamental biogeochemical problem of closing marine fixed-nitrogen budgets in intensely oxygen-deficient regions. The degree to which the cryptic sulphur cycle can fuel a loss of fixed nitrogen in the modern ocean requires the quantification of sulphur recycling in OMZ settings. Here we provide a new constraint for OMZ sulphate reduction based on isotopic profiles of oxygen ((18)O/(16)O) and sulphur ((33)S/(32)S, (34)S/(32)S) in seawater sulphate through oxygenated open-ocean and OMZ-bearing water columns. When coupled with observations and models of sulphate isotope dynamics and data-constrained model estimates of OMZ water-mass residence time, we find that previous estimates for sulphur-driven remineralization and loss of fixed nitrogen from the oceans are near the upper limit for what is possible given in situ sulphate isotope data.


Assuntos
Água do Mar/química , Enxofre/análise , Amônia/metabolismo , Anaerobiose , Organismos Aquáticos/metabolismo , Nitrogênio/metabolismo , Fixação de Nitrogênio , Oxirredução , Oxigênio/análise , Oxigênio/metabolismo , Isótopos de Oxigênio , Enxofre/química , Enxofre/metabolismo , Isótopos de Enxofre
6.
Mol Psychiatry ; 23(4): 892-903, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-28416809

RESUMO

Chronic stress can be a precipitating factor in the onset of depression. Lentiviral-mediated knockdown of HCN1 protein expression and reduction of functional Ih produce antidepressant behavior. However, whether h-channels are altered in an animal model of depression is not known. We found that perisomatic HCN1 protein expression and Ih-sensitive physiological measurements were significantly increased in dorsal but not in ventral CA1 region/neurons following chronic unpredictable stress (CUS), a widely accepted model for major depressive disorder. Cell-attached patch clamp recordings confirmed that perisomatic Ih was increased in dorsal CA1 neurons following CUS. Furthermore, when dorsal CA1 Ih was reduced by shRNA-HCN1, the CUS-induced behavioral deficits were prevented. Finally, rats infused in the dorsal CA1 region with thapsigargin, an irreversible inhibitor of the SERCA pump, exhibited anxiogenic-like behaviors and increased Ih, similar to that observed following CUS. Our results suggest that CUS, but not acute stress, leads to an increase in perisomatic Ih in dorsal CA1 neurons and that HCN channels represent a potential target for the treatment of major depressive disorder.


Assuntos
Depressão/metabolismo , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/metabolismo , Canais de Potássio/metabolismo , Estresse Psicológico/fisiopatologia , Potenciais de Ação , Animais , Antidepressivos/metabolismo , Região CA1 Hipocampal/metabolismo , Canais de Cátion Regulados por Nucleotídeos Cíclicos , Transtorno Depressivo Maior/metabolismo , Modelos Animais de Doenças , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/genética , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/fisiologia , Masculino , Neurônios/metabolismo , Técnicas de Patch-Clamp/métodos , Canais de Potássio/genética , Canais de Potássio/fisiologia , Ratos , Ratos Sprague-Dawley , Estresse Psicológico/metabolismo , Tapsigargina/farmacologia
7.
J Dairy Sci ; 102(12): 10887-10902, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31548054

RESUMO

The European livestock sector has a significant deficit of high-quality protein feed ingredients. Consequently there is interest in using locally grown protein grain crops to partially or completely replace imported protein feeds in dairy cow rations. Field bean (FB; Vicia faba) has been identified as a locally grown crop with significant potential. The current study was designed to examine the effects of FB on cow performance and nutrient utilization in the diet of early-lactation dairy cows, including high levels of FB (up to 8.4 kg/cow per day). The experiment used 72 dairy cows in a 3-treatment continuous design (from calving until wk 20 of lactation). All cows were given ad libitum access to a mixed ration comprising grass silage and concentrates [45:55 on a dry matter (DM) basis]. Concentrates offered contained either 0, 349, or 698 g of FB/kg of concentrate (treatments FB0, FB-Low, and FB-High, respectively), with FB completely replacing soybean meal, rapeseed meal, maize gluten, and wheat in the concentrate for the FB-High treatment. Following completion of the 20-wk experiment, ration digestibility, nutrient utilization, and methane (CH4) production were measured using 4 cows from each treatment. Neither silage DM intake, total DM intake, nor milk yield were affected by treatment. Cows on FB0 had a higher milk fat content than those on FB-High, and cows on FB0 and FB-Low had higher milk protein contents than did those on FB-High. Field bean inclusion increased the degree of saturation of milk fat produced. Milk fat yield, milk protein yield, and milk fat plus protein yield were higher with FB0 than with either FB-Low or FB-High. Treatment had no effect on the digestibility of DM, organic matter, nitrogen (N), gross energy, or neutral detergent fiber, whereas digestibility of acid detergent fiber was higher with FB0 than with FB-High. Neither the efficiency of gross energy or N utilization, nor any of the CH4 production parameters examined, were affected by treatment. Similarly, none of the fertility or health parameters examined were affected by treatment. The reduction in milk fat observed may have been due to the higher starch content of the FB-High diet, and the reduction in milk protein may have been due to a deficit of methionine in the diet. It is likely that these issues could be overcome by changes in ration formulation, thus allowing FB to be included at the higher range without loss in performance.


Assuntos
Ração Animal , Bovinos , Vicia faba , Animais , Brassica rapa , Dieta/veterinária , Digestão , Feminino , Lactação , Metano/biossíntese , Leite/química , Proteínas do Leite , Poaceae , Silagem/análise , Glycine max , Zea mays
8.
J Anat ; 232(6): 1025-1030, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29520782

RESUMO

Current tissue-clearing protocols for imaging in three dimensions (3D) are typically applied to optimally fixed, small-volume rodent brain tissue - which is not representative of the tissue found in diagnostic neuropathology laboratories. We present a method to visualise the cerebral cortical vasculature in 3D in human post-mortem brain tissue which had been preserved in formalin for many years. Tissue blocks of cerebral cortex from two control cases, two Alzheimer's brains and two cases from Alzheimer's patients immunised against Aß42 were stained with fluorescent Lycopersicon esculentum agglutinin (Tomato lectin), dehydrated and cleared using an adapted three-dimensional imaging of solvent cleared organs (3DISCO) protocol to visualise the vascular endothelium. Tissue was imaged using light sheet and confocal microscopy and reconstructed in 3D using amira software. The method permits visualisation of the arrangement of the parallel penetrating cortical vasculature in the human brain. The presence of four vascular features including anastomosis, U-shaped vessels, spiralling and loops were revealed. In summary, we present a low cost and simple method to visualise the human cerebral vasculature in 3D compatible with prolonged fixation times (years), allowing study of vascular involvement in a range of normative and pathological states.


Assuntos
Córtex Cerebral/irrigação sanguínea , Circulação Cerebrovascular , Técnicas de Preparação Histocitológica , Imageamento Tridimensional/métodos , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino
9.
Allergy ; 73(9): 1871-1880, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29688579

RESUMO

BACKGROUND: Effective inhibition of plasma kallikrein may have significant benefits for patients with hereditary angioedema due to deficiency of C1 inhibitor (C1-INH-HAE) by reducing the frequency of angioedema attacks. Avoralstat is a small molecule inhibitor of plasma kallikrein. This study (OPuS-2) evaluated the efficacy and safety of prophylactic avoralstat 300 or 500 mg compared with placebo. METHODS: OPuS-2 was a Phase 3, multicenter, randomized, double-blind, placebo-controlled, parallel-group study. Subjects were administered avoralstat 300 mg, avoralstat 500 mg, or placebo orally 3 times per day for 12 weeks. The primary efficacy endpoint was the angioedema attack rate based on adjudicator-confirmed attacks. RESULTS: A total of 110 subjects were randomized and dosed. The least squares (LS) mean attack rates per week were 0.589, 0.675, and 0.593 for subjects receiving avoralstat 500 mg, avoralstat 300 mg, and placebo, respectively. Overall, 1 subject in each of the avoralstat groups and no subjects in the placebo group were attack-free during the 84-day treatment period. The LS mean duration of all confirmed attacks was 25.4, 29.4, and 31.4 hours for the avoralstat 500 mg, avoralstat 300 mg, and placebo groups, respectively. Using the Angioedema Quality of Life Questionnaire (AE-QoL), improved QoL was observed for the avoralstat 500 mg group compared with placebo. Avoralstat was generally safe and well tolerated. CONCLUSIONS: Although this study did not demonstrate efficacy of avoralstat in preventing angioedema attacks in C1-INH-HAE, it provided evidence of shortened angioedema episodes and improved QoL in the avoralstat 500 mg treatment group compared with placebo.


Assuntos
Angioedemas Hereditários/prevenção & controle , Inibidores Enzimáticos/uso terapêutico , Calicreína Plasmática/antagonistas & inibidores , Administração Oral , Adulto , Angioedemas Hereditários/diagnóstico , Angioedemas Hereditários/tratamento farmacológico , Progressão da Doença , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/efeitos adversos , Inibidores Enzimáticos/farmacocinética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Qualidade de Vida , Recidiva , Resultado do Tratamento
10.
Epidemiol Infect ; 147: e28, 2018 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-30326986

RESUMO

During the summer of 2016, the Hawaii Department of Health responded to the second-largest domestic foodborne hepatitis A virus (HAV) outbreak in the post-vaccine era. The epidemiological investigation included case finding and investigation, sequencing of RNA positive clinical specimens, product trace-back and virologic testing and sequencing of HAV RNA from the product. Additionally, an online survey open to all Hawaii residents was conducted to estimate baseline commercial food consumption. We identified 292 confirmed HAV cases, of whom 11 (4%) were possible secondary cases. Seventy-four (25%) were hospitalised and there were two deaths. Among all cases, 94% reported eating at Oahu or Kauai Island branches of Restaurant Chain A, with 86% of those cases reporting raw scallop consumption. In contrast, a food consumption survey conducted during the outbreak indicated 25% of Oahu residents patronised Restaurant Chain A in the 7 weeks before the survey. Product trace-back revealed a single distributor that supplied scallops imported from the Philippines to Restaurant Chain A. Recovery, amplification and sequence comparison of HAV recovered from scallops revealed viral sequences matching those from case-patients. Removal of product from implicated restaurants and vaccination of those potentially exposed led to the cessation of the outbreak. This outbreak further highlights the need for improved imported food safety.

11.
Nature ; 483(7389): 320-3, 2012 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-22388817

RESUMO

Interpretations of major climatic and biological events in Earth history are, in large part, derived from the stable carbon isotope records of carbonate rocks and sedimentary organic matter. Neoproterozoic carbonate records contain unusual and large negative isotopic anomalies within long periods (10-100 million years) characterized by δ(13)C in carbonate (δ(13)C(carb)) enriched to more than +5 per mil. Classically, δ(13)C(carb) is interpreted as a metric of the relative fraction of carbon buried as organic matter in marine sediments, which can be linked to oxygen accumulation through the stoichiometry of primary production. If a change in the isotopic composition of marine dissolved inorganic carbon is responsible for these excursions, it is expected that records of δ(13)C(carb) and δ(13)C in organic carbon (δ(13)C(org)) will covary, offset by the fractionation imparted by primary production. The documentation of several Neoproterozoic δ(13)C(carb) excursions that are decoupled from δ(13)C(org), however, indicates that other mechanisms may account for these excursions. Here we present δ(13)C data from Mongolia, northwest Canada and Namibia that capture multiple large-amplitude (over 10 per mil) negative carbon isotope anomalies, and use these data in a new quantitative mixing model to examine the behaviour of the Neoproterozoic carbon cycle. We find that carbonate and organic carbon isotope data from Mongolia and Canada are tightly coupled through multiple δ(13)C(carb) excursions, quantitatively ruling out previously suggested alternative explanations, such as diagenesis or the presence and terminal oxidation of a large marine dissolved organic carbon reservoir. Our data from Namibia, which do not record isotopic covariance, can be explained by simple mixing with a detrital flux of organic matter. We thus interpret δ(13)C(carb) anomalies as recording a primary perturbation to the surface carbon cycle. This interpretation requires the revisiting of models linking drastic isotope excursions to deep ocean oxygenation and the opening of environments capable of supporting animals.


Assuntos
Ciclo do Carbono/fisiologia , Animais , Canadá , Isótopos de Carbono/análise , Sedimentos Geológicos/química , História Antiga , Mongólia , Namíbia , Oceanos e Mares , Água do Mar/química
12.
Support Care Cancer ; 26(2): 549-555, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28856448

RESUMO

CONTEXT: There are no prospective pediatric trials evaluating olanzapine for chemotherapy-induced nausea and vomiting (CINV) prevention. OBJECTIVE: This study evaluated the feasibility of a trial of olanzapine to evaluate the contribution of olanzapine to CINV control in pediatric oncology patients. METHODS: Patients < 18 years receiving CINV prophylaxis with ondansetron/granisetron/palonosetron ± dexamethasone ± aprepitant were eligible to participate in this prospective, single-arm, open-label study. All patients received olanzapine (0.14 mg/kg/dose; max 10 mg/dose) once daily orally starting before the first chemotherapy dose and continuing for up to four doses after the last chemotherapy administration. A future trial was considered feasible if mean time to enroll 15 patients was ≤ 12 months/site, ≥ 12/15 took at least half of the planned olanzapine doses, and ≤ 3/15 experienced significant sedation or dizziness despite dose reduction. The proportion of children who experienced complete CINV control (no nausea, vomiting, or retching) was described. RESULTS: Fifteen patients (range 4.1-17.4 years) participated; mean recruitment period was 9.3 months/site. All patients took at least half of the planned olanzapine doses. Six patients experienced sedation which resolved with olanzapine dose reduction (N = 5) or bedtime administration (N = 1). Olanzapine was stopped in one patient with blurry vision and in another with increased plasma GGT values. In both the acute and delayed phases, eight patients experienced complete control of vomiting but almost all (14/15) had nausea. CONCLUSION: A pediatric trial of olanzapine for CINV control is feasible. Our findings will inform the design of a future study.


Assuntos
Antieméticos/uso terapêutico , Náusea/tratamento farmacológico , Olanzapina/uso terapêutico , Vômito/tratamento farmacológico , Adolescente , Antieméticos/administração & dosagem , Antieméticos/farmacologia , Criança , Pré-Escolar , Estudos de Viabilidade , Feminino , Humanos , Masculino , Náusea/induzido quimicamente , Olanzapina/administração & dosagem , Olanzapina/farmacologia , Vômito/induzido quimicamente
13.
BMC Psychiatry ; 18(1): 166, 2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29859060

RESUMO

BACKGROUND: Depression is a commonly occurring disorder linked to diminished role functioning and quality of life. The development of treatments that overcome barriers to accessing treatment remains an important area of clinical research as most people delay or do not receive treatment at an appropriate time. The workplace is an ideal setting to roll-out an intervention, particularly given the substantial psychological benefits associated with remaining in the workforce. Mobile health (mhealth) interventions utilising smartphone applications (apps) offer novel solutions to disseminating evidence based programs, however few apps have undergone rigorous testing. The present study aims to evaluate the effectiveness of a smartphone app designed to treat depressive symptoms in workers. METHODS: The present study is a multicentre randomised controlled trial (RCT), comparing the effectiveness of the intervention to that of an attention control. The primary outcome measured will be reduced depressive symptoms at 3 months. Secondary outcomes such as wellbeing and work performance will also be measured. Employees from a range of industries will be recruited via a mixture of targeted social media advertising and Industry partners. Participants will be included if they present with likely current depression at baseline. Following baseline assessment (administered within the app), participants will be randomised to receive one of two versions of the Headgear application: 1) Intervention (a 30-day mental health intervention focusing on behavioural activation and mindfulness), or 2) attention control app (mood monitoring for 30 days). Participants will be blinded to their allocation. Analyses will be conducted within an intention to treat framework using mixed modelling. DISCUSSION: The results of this trial will provide valuable information about the effectiveness of mhealth interventions in the treatment of depressive symptoms in a workplace context. TRIAL REGISTRATION: The current trial is registered with the Australian and New Zealand Clinical Trials Registry ( ACTRN12617000547347 , Registration date: 19/04/2017).


Assuntos
Protocolos Clínicos/normas , Terapia Cognitivo-Comportamental/instrumentação , Depressão/terapia , Smartphone/instrumentação , Adulto , Depressão/diagnóstico , Transtorno Depressivo/terapia , Feminino , Humanos , Masculino , Aplicativos Móveis , Ensaios Clínicos Controlados Aleatórios como Assunto , Projetos de Pesquisa , Telemedicina , Terapia Assistida por Computador/métodos , Resultado do Tratamento
14.
Phys Rev Lett ; 119(25): 257203, 2017 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-29303352

RESUMO

The inference of Ying et al. [Europhys. Lett. 104, 67005 (2013)EULEEJ0295-507510.1209/0295-5075/104/67005] of a composition-induced change from c-axis ordered-moment alignment in a collinear A-type antiferromagnetic (AFM) structure at small x to ab-plane alignment in an unknown AFM structure at larger x in Ca_{1-x}Sr_{x}Co_{2-y}As_{2} with the body-centered tetragonal ThCr_{2}Si_{2} structure is confirmed. Our major finding is an anomalous magnetic behavior in the crossover region 0.2≲x≲0.3 between these two phases. In this region the magnetic susceptibility vs temperature χ_{ab}(T) measured with magnetic fields H applied in the ab plane exhibit typical AFM behaviors with cusps at the Néel temperatures of ∼ 65 K, whereas χ_{c}(T) and the low-temperature isothermal magnetization M_{c}(H) with H aligned along the c axis exhibit extremely soft ferromagneticlike behaviors.

15.
Phys Rev Lett ; 119(14): 147201, 2017 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-29053286

RESUMO

Inelastic neutron scattering measurements on the itinerant antiferromagnet CaCo_{2-y}As_{2} at a temperature of 8 K reveal two orthogonal planes of scattering perpendicular to the Co square lattice in reciprocal space, demonstrating the presence of effective one-dimensional spin interactions. These results are shown to arise from near-perfect bond frustration within the J_{1}-J_{2} Heisenberg model on a square lattice with ferromagnetic J_{1} and hence indicate that the extensive previous experimental and theoretical study of the J_{1}-J_{2} Heisenberg model on local-moment square spin lattices should be expanded to include itinerant spin systems.

16.
J Neurooncol ; 133(3): 581-587, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28508928

RESUMO

Embryonal tumors are a heterogeneous group of central nervous system (CNS) tumors whose subgroups have varying incidence and outcome. Despite these differences, they are often grouped as a single entity for study purposes. To date, there are no Canadian multi-institutional studies examining the incidence and outcome of all embryonal subtypes. The current study is an observational study reviewing embryonal tumors in all patients less than 36 months of age diagnosed with a CNS tumor in Canada from 1990 to 2005. Embryonal tumors accounted for 26.9% of all CNS tumors. Medulloblastomas were the highest proportion of the embryonal tumors at 61.5%. Atypical teratoid/rhabdoid tumors (AT/RT) had the second highest proportion of embryonal tumors at 18%. The proportion of primitive neuroectodermal tumors (PNET) was 16%, with 2.6 and 1.9% for congenital medulloepithelioma and ependymoblastoma tumors, respectively. AT/RT and PNET were more common in younger age groups. Medulloblastoma became more prevalent with increasing age, with its highest prevalence in the 25 to 36 month age group. Survival rates for our Canadian population at 18 and 24 months were 0.74 and 0.68 for medulloblastoma, 0.64 and 0.60 for PNET, and 0.36 and 0.29 for AT/RT, respectively. Overall, our data are comparable with published international rates for embryonal tumors. These incidence and outcome figures can guide future research into these rare tumors.


Assuntos
Neoplasias do Sistema Nervoso Central/epidemiologia , Neoplasias Embrionárias de Células Germinativas/epidemiologia , Canadá/epidemiologia , Neoplasias do Sistema Nervoso Central/terapia , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Neoplasias Embrionárias de Células Germinativas/terapia , Análise de Sobrevida
17.
J Arthroplasty ; 32(3): 818-823, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27693054

RESUMO

BACKGROUND: This 10-year follow-up compares health-related quality of life (HRQL) and reoperations in 100 subjects who were randomized to receive posterior cruciate ligament substituting (PS) or posterior cruciate ligament retaining (CR) total knee arthroplasty. We previously reported 2-year results. METHODS: Subjects were enrolled preoperatively and randomized at surgery. Subjects completed HRQL questionnaires at all evaluation points. Subjects were re-evaluated at 2 and 10 years with reoperations determined through regional medical record review and patient report. RESULTS: Over 10 years, 25 (25%) subjects died, 2 subjects were revised and withdrew, and 11 (11%) subjects were lost to follow-up. Of survivors, 62 of 75 (83%) were evaluated at 10 years. Twenty-eight (37%) subjects provided HRQL, radiographic, and reoperation status, 28 (37%) subjects completed HRQL evaluations and reoperation status only, and 6 (8%) subjects provided radiographic and reoperation follow-up. Both groups retained good HRQL between 2 and 10 years with no group differences noted (P > .35). One revision (CR subject), secondary to deep joint infection, occurred within 2 years with 1 further revision (PS subject) occurring at 3 years postoperatively. One subject (PS subject) required manipulation under anesthesia within 3 months of surgery. Four subjects required late patellar resurfacing (1 CR subject, 3 PS subjects) but were retained in the 10-year evaluation. Overall, reoperations were not significantly different between groups (P = .26). CONCLUSION: Over 10 years postoperatively, both the PS and CR total knee arthroplasty performed well with subjects reporting acceptable levels of HRQL up to 10 years postoperatively; low levels of revision or reoperation were reported in both groups.


Assuntos
Artroplastia do Joelho/métodos , Prótese do Joelho , Ligamento Cruzado Posterior/cirurgia , Desenho de Prótese , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Dor Pós-Operatória , Período Pós-Operatório , Qualidade de Vida , Amplitude de Movimento Articular , Reoperação , Inquéritos e Questionários
18.
J Women Aging ; 28(5): 418-30, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27143397

RESUMO

This is an interview-based study focused on how professional baby boomer women negotiate and narrate postretirement lives. This group came of age in the 1960s and represents a socially privileged segment of the baby boomer generation, a cohort that created new gendered pathways in employment. Today, these retired professional women are attempting to make sense of their multilayered complex and changing realities. In their accounts, the most salient themes are shifting identity, embodiment, and relationships. By using what we call a relational lens, we will show how many aspects of postretirement life, for these professional women, are mediated by changing relationships-relationships to time, work identity, friends and family, and body. Through these individual and relational contexts we see how female professional baby boomer retirees grapple with liberation and loss, autonomy and control, ongoing gendered work, and rebalancing in a new chapter of life. Perhaps most importantly, we see how learning about self in this stage of life, and perhaps across the life course, takes place largely in the context of relationships.


Assuntos
Imagem Corporal , Emprego/psicologia , Relações Interpessoais , Qualidade de Vida , Aposentadoria/psicologia , Idoso , Feminino , Identidade de Gênero , Humanos , Pessoa de Meia-Idade , Pesquisa Qualitativa
19.
Phys Rev Lett ; 115(13): 137001, 2015 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-26451577

RESUMO

In the iron pnictide superconductors, theoretical calculations have consistently shown enhancements of the static magnetic susceptibility at both the stripe-type antiferromagnetic and in-plane ferromagnetic (FM) wave vectors. However, the possible existence of FM fluctuations has not yet been examined from a microscopic point of view. Here, using ^{75}As NMR data, we provide clear evidence for the existence of FM spin correlations in both the hole- and electron-doped BaFe_{2}As_{2} families of iron-pnictide superconductors. These FM fluctuations appear to compete with superconductivity and are thus a crucial ingredient to understanding the variability of T_{c} and the shape of the superconducting dome in these and other iron-pnictide families.

20.
Phys Rev Lett ; 114(21): 217001, 2015 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-26066451

RESUMO

X-ray magnetic circular dichroism (XMCD) measurements on single-crystal and powder samples of Ba_{0.6}K_{0.4}Mn_{2}As_{2} show that the ferromagnetism below T_{C}≈100 K arises in the As 4p conduction band. No XMCD signal is observed at the Mn x-ray absorption edges. Below T_{C}, however, a clear XMCD signal is found at the As K edge which increases with decreasing temperature. The XMCD signal is absent in data taken with the beam directed parallel to the crystallographic c axis indicating that the orbital magnetic moment lies in the basal plane of the tetragonal lattice. These results show that the previously reported itinerant ferromagnetism is associated with the As 4p conduction band and that distinct local-moment antiferromagnetism and itinerant ferromagnetism with perpendicular easy axes coexist in this compound at low temperature.

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