Singlet-triplet splittings in free and self-trapped excitons

We discuss the available experimental data for the singlet-triplet splitting of free and self-trapped excitons in alkali halides. These data are analysed quantitatively using the pseudopotential method of Bartram, Stoneham and Gash. The predictions confirm the trend emerging from the observed data, namely that the splittings are systematically lower for the self-trapped systems. This difference comes principally from the spread of the self-trapped hole onto two ions, and would not be expected, for example, if the hole were localised on a single site

Impact of breastfeeding on infectious disease hospitalisation: the Children of 1997 cohort

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A brief group intervention using a cognitive-behavioural approach to reduce postnatal depressive symptoms: a randomised controlled trial

Key Messages: 1. Postnatal women preferred psychotherapy to pharmacotherapy for reduction of postnatal depression. ; 2. A brief, cognitive-behavioural, group intervention with 6 weekly sessions significantly reduced depressive symptoms and was well received by postnatal women. ; 3. This brief group intervention could be further tested as an integral part of postnatal care to complement existing services and reduce waiting time

AVALIAÇÃO DA APRENDIZAGEM À LUZ DA PEDAGOGIA HISTÓRICO-CRÍTICA: contribuições para a formação de professores

Essa dissertação tem como objeto de estudo a avaliação da aprendizagem na educação infantil e, dessa forma, realizamos um levantamento da literatura que evidencia a ausência de produções sobre essa temática, sobretudo, com base no referencial da pedagogia histórico-crítica, o que acarretou inquietações que nos mobilizaram a desenvolver essa pesquisa, pois é imprescindível evidenciar as contribuições dessa teoria pedagógica para a organização dos processos avaliativos. Tomando como base de análise o referencial da pedagogia histórico-crítica, elegemos as seguintes questões de pesquisa: 1) Qual a predominância teórica nos estudos da área da avaliação da aprendizagem escolar e quais os fundamentos epistemológicos subjacentes às produções sobre avaliação da aprendizagem? 2) Que fundamentos epistemológicos têm subsidiado as Diretrizes Curriculares Nacionais para a Educação Infantil (DCNEI), no que se refere à avaliação da aprendizagem? 3) Que contradições são evidenciadas nas discussões em torno da avaliação na educação infantil? Considerando o tema dessa pesquisa, estabelecemos como objetivo geral analisar, à luz da pedagogia histórico-crítica, a predominância dos estudos na área da avaliação da aprendizagem escolar na educação infantil, buscando as suas contradições e possibilidades. Assim, delimitamos como objetivos específicos: identificar a concepção de avaliação e os fundamentos epistemológicos mais predominantes nas produções acadêmicas encontradas na Biblioteca Digital Brasileira de Teses e Dissertações (BDTD); examinar os fundamentos epistemológicos que têm subsidiado as Diretrizes Curriculares Nacionais para Educação Infantil sobre a avaliação da aprendizagem escolar; elucidar as contradições presentes nas discussões sobre a avaliação da aprendizagem na Educação Infantil. Qual a predominância nos estudos na área da avaliação da aprendizagem escolar e quais os fundamentos epistemológicos adjacentes às produções sobre avaliação da aprendizagem? Que contradições são evidenciadas nas discussões em torno da avaliação na educação infantil? Diante de tais contradições, quais as contribuições da pedagogia histórico-crítica para a compreensão da avaliação da aprendizagem? Essa pesquisa é de natureza teórica, de cunho bibliográfico e documental. Os resultados apontam duas contradições em torno das discussões sobre a avaliação na educação infantil: não percebemos, nos documentos analisados nem nos autores mais citados nas produções acadêmicas, uma ruptura com o ideário defendido pela lógica neoliberal, mas sim um alinhamento a este, o que vai de encontro ao reais e necessários interesses da classe trabalhadora. Tendo em vista a hegemonia de um discurso que se vincula ao ideário do aprender a aprender, outra contradição decorrente dessa aliança com o projeto neoliberal refere-se ao crescente esvaziamento dos conteúdos escolares, sejam eles históricos, artísticos ou filosóficos. Nossa defesa é a de que a educação infantil necessita ter o ensino como eixo para sua organização. Buscando sinalizar alguns elementos sobre a avaliação da aprendizagem no âmbito da pedagogia histórico-crítica, entendemos que ela se constitui como atividade mediadora no interior da prática educativa, na medida em que se interpõe entre a atividade de ensino e a atividade de aprendizagem. Entender a avaliação como atividade mediadora significa superar a ideia de mediação como elo ou ponte e entendê-la como movimento da atividade que se interpõe sobre os polos da atividade de ensino (professor) e da atividade de aprendizagem (aluno), captando suas relações e ultrapassando-as, promovendo a transformação de todo o conjunto

Antenatal anxiety in the first trimester: Risk factors and effects on anxiety and depression in the third trimester and 6-week postpartum

Objective: Anxiety is common among pregnant women. However, research attention in the area of reproductive mental health has mainly focused on postpartum depression in past decades. Given adverse outcomes of antenatal anxiety, there is an urgent need to fill the research gaps. The objectives of the present study were to determine the prevalence of antenatal anxiety symptoms and examine the risk factors and effects of anxiety symptoms in early pregnancy on anxiety and depressive symptoms in later pregnancy and early postpartum period. Methodology: A prospective longitudinal design with quantitative approach was adopted. A consecutive sample of 1470 Chinese pregnant women from hospitals in Hong Kong was invited to participate in the study and was assessed using standardized instruments on 3 time points including first and third trimesters of pregnancy and 6-week postpartum. Results: The results showed that 17.7% of pregnant women manifested anxiety symptoms in the first trimester of pregnancy. Single mothers, younger mothers, mothers who smoked before pregnancy and mothers who received low education level reported significantly higher levels of anxiety symptoms in the first trimester. Unwanted pregnancy, low self esteem, low marital satisfaction and perceived low social support were significant psychosocial risk factors for anxiety symptoms in the first trimester. Anxiety symptoms in the first trimester were independent predictors for anxiety symptoms in the third trimester ( QUOTE β = 0.26, t = 5.74, p < 0.001), however anxiety symptoms in the first trimester no longer significantly predicted anxiety and depressive symptoms in 6 weeks postpartum after adjusting for the effects of potential confounders. Discussions: The present study points to the need for greater research and clinical attention to antenatal anxiety given that antenatal anxiety is a prevalent problem and has serious impacts on maternal well-being. Such findings also contribute to the understanding of maternal anxiety and have implications for the design of effective identification, prevention and treatment of these significant clinical problemspublished_or_final_versio

BaBi₂O₆: A Promising n-Type Thermoelectric Oxide with the PbSb₂O₆ Crystal Structure

Thermoelectric materials offer the possibility of enhanced energy efficiency due to waste heat scavenging. Based on their high-temperature stability and ease of synthesis, efficient oxide-based thermoelectrics remain a tantalizing research goal; however, their current performance is significantly lower than the industry standards such as Bi_{2}Te_{3} and PbTe. Among the oxide thermoelectrics studied thus far, the development of n-type thermoelectric oxides has fallen behind that of p-type oxides, primarily due to limitations on the overall dimensionless figure of merit, or ZT, by large lattice thermal conductivities. In this article, we propose a simple strategy based on chemical intuition to discover enhanced n-type oxide thermoelectrics. Using state-of-the-art calculations, we demonstrate that the PbSb_{2}O_{6}-structured BaBi_{2}O_{6} represents a novel structural motif for thermoelectric materials, with a predicted ZT of 0.17–0.19. We then suggest two methods to enhance the ZT up to 0.22, on par with the current best earth-abundant n-type thermoelectric at around 600 K, SrTiO_{3}, which has been much more heavily researched. Our analysis of the factors that govern the electronic and phononic scattering in this system provides a blueprint for optimizing ZT beyond the perfect crystal approximation

Associations between maternal urinary iodine assessment, dietary iodine intakes and neurodevelopmental outcomes in the child: A Systematic Review

Abstract Objective Mild to moderate iodine deficiency during pregnancy has been associated with adverse neurodevelopmental outcomes in offspring. Few research studies to date combine assessment of urinary iodine (UIC and/or ICr), biomarkers that best reflect dietary intake, with reported dietary intake of iodine rich foods in their assessment of iodine deficiency. Thus, a systematic review was conducted to incorporate both these important measures. Design Using PRISMA guidelines, a comprehensive search was conducted in three electronic databases (EMBASE®, MedLine® and Web of Science®) from January 1970–March 2021. Quality assessment was undertaken using the Newcastle Ottawa Scale. Eligible studies included reported assessment of iodine status through urinary iodine (UIC and/or ICr) and/or dietary intake measures in pregnancy alongside neurodevelopmental outcomes measured in the children. Data extracted included study author, design, sample size, country, gestational age, child age at testing, cognitive tests, urinary iodine assessment (UIC in μg/L and/or ICr in μg/g), dietary iodine intake assessment and results of associations for the assessed cognitive outcomes. Results Twelve studies were included with nine reporting women as mild-moderately iodine deficient based on World Health Organization (WHO) cut-offs for urinary iodine measurements < 150 μg/l, as the median UIC value in pregnant women. Only four of the nine studies reported a negative association with child cognitive outcomes based on deficient urinary iodine measurements. Five studies reported urinary iodine measurements and dietary intakes with four of these studies reporting a negative association of lower urinary iodine measurements and dietary iodine intakes with adverse offspring neurodevelopment. Milk was identified as the main dietary source of iodine in these studies. Conclusion The majority of studies classified pregnant women to be mild-moderately iodine deficient based on urinary iodine assessment (UIC and/or ICr) and/or dietary intakes, with subsequent offspring neurodevelopment implications identified. Although a considerable number of studies did not report an adverse association with neurodevelopmental outcomes, these findings are still supportive of ensuring adequate dietary iodine intakes and urinary iodine monitoring throughout pregnancy due to the important role iodine plays within foetal neurodevelopment. This review suggests that dietary intake data may indicate a stronger association with cognitive outcomes than urinary iodine measurements alone. The strength of this review distinguishes results based on cognitive outcome per urinary iodine assessment strategy (UIC and/or ICr) with dietary data. Future work is needed respecting the usefulness of urinary iodine assessment (UIC and/or ICr) as an indicator of deficiency whilst also taking account of dietary intakes

Determinants of serum 25-hydroxyvitamin D in Hong Kong

Vitamin D plays an important role in skeletal health throughout life. Some studies have hypothesised that vitamin D may reduce the risk of other diseases. Our study aimed to estimate age-specific and sex-specific serum 25-hydroxyvitamin D (25(OH)D) status and to identify the determinants of serum 25(OH)D status in Hong Kong, a subtropical city in southern China. In 2009-2010, households in Hong Kong were followed up to identify acute respiratory illnesses, and sera from 2694 subjects were collected in three to four different study phases to permit measurement of 25(OH)D levels at different times of the year. A questionnaire survey on diet and lifestyle was conducted among children, with simultaneous serum collection in April and May 2010. The mean of serum 25(OH)D levels in age groups ranged from 39 to 63 nmol/l throughout the year with the mean values in all age groups in spring below 50 nmol/l. Children aged 6-17 years, and girls and women had significantly lower serum 25(OH)D levels than adults, and boys and men, respectively (all P< 0·001). We estimated that serum 25(OH)D levels in Hong Kong followed a lagged pattern relative to climatic season by 5 weeks with lowest observed levels in early spring (March). For children aged 6-17 years, reporting a suntan, having at least 1 servings of fish/week and having at least 1 serving of eggs/week were independently associated with higher serum 25(OH)D levels. Adequate sunlight exposure and increased intake of dietary vitamin D could improve vitamin D status, especially for children and females in the winter and spring.postprin

Inertia based microfluidic capture and characterisation of circulating tumour cells for the diagnosis of lung cancer

Background: Routine clinical application of circulating tumour cells (CTCs) for blood based diagnostics is yet to be established. Despite growing evidence of their clinical utility for diagnosis, prognosis and treatment monitoring, the efficacy of a robust platform and universally accepted diagnostic criteria remain uncertain. We evaluate the diagnostic performance of a microfluidic CTC isolation platform using cytomorphologic criteria in patients undergoing lung cancer surgery. Methods: Blood was processed from 51 patients undergoing surgery for known or suspected lung cancer using the ClearBridge ClearCell FX systemTM (ClearBridge Biomedics, Singapore). Captured cells were stained on slides with haematoxylin and eosin (H&E) and independently assessed by two pathologist teams. Diagnostic performance was evaluated against the pathologists reported diagnosis of cancer from surgically obtained specimens. Results: Cancer was diagnosed in 43.1% and 54.9% of all cases. In early stage primary lung cancer, between the two reporting teams, a positive diagnosis of CTCs was made for 50% and 66.7% of patients. The agreement between the reporting teams was 80.4%, corresponding to a kappa-statistic of 0.61±0.11 (P<0.001), indicating substantial agreement. Sensitivity levels for the two teams were calculated as 59% (95% CI, 41–76%) and 41% (95% CI, 24–59%), with a specificity of 53% for both. Conclusions: The performance of the tested microfluidic antibody independent device to capture CTCs using standard cytomorphological criteria provides the potential of a diagnostic blood test for lung cancer

The actions of methotrexate on endothelial cells are dependent on the shear stress-induced regulation of one carbon metabolism

Objectives: The disease-modifying anti-rheumatic drug methotrexate (MTX) is recognized to reduce cardiovascular risk in patients with systemic inflammatory diseases. However, the molecular basis for these cardioprotective effects remains incompletely understood. This study evaluated the actions of low-dose MTX on the vascular endothelium. Methods: Human endothelial cells (EC) were studied under in vitro conditions relevant to inflammatory arthritis. These included culture in a pro-inflammatory microenvironment and exposure to fluid shear stress (FSS) using a parallel plate model. Respectively treated cells were analyzed by RNA sequencing and quantitative real-time PCR for gene expression, by immunoblotting for protein expression, by phosphokinase activity arrays, by flow cytometry for cell cycle analyses and by mass spectrometry to assess folate metabolite levels. Results: In static conditions, MTX was efficiently taken up by EC and caused cell cycle arrest concurrent with modulation of cell signaling pathways. These responses were reversed by folinic acid (FA), suggesting that OCM is a predominant target of MTX. Under FSS, MTX did not affect cell proliferation or pro-inflammatory gene expression. Exposure to FSS downregulated endothelial one carbon metabolism (OCM) as evidenced by decreased expression of key OCM genes and metabolites. Conclusion: We found that FSS significantly downregulated OCM and thereby rendered EC less susceptible to the effects of MTX treatment. The impact of shear stress on OCM suggested that MTX does not directly modulate endothelial function. The cardioprotective actions of MTX likely reflect direct actions on inflammatory cells and indirect benefit on the vascular endothelium