Shape-controlled monolayer MoSe2 flakes by chemical vapor deposition towards tuning the photoluminescence emission

In this study, we report on the controllable chemical vapor deposition (CVD) synthesis of monolayer MoSe2 flakes with different shapes such as hexagons, triangles, sawtooth hexagons, dendrites and fractals deposited on SiO2/Si substrates. This broad range of morphologies is due to the change in the vapor composition resulting from the confinement of the MoO3 and Se vapor and to the variation in the growth rate of the variable shaped MoSe2 crystals. It is also revealed that the photoluminescence (PL) response of the MoSe2 flakes is strongly affected by their shape and size. Our findings will open new avenues towards achieving morphology-controlled monolayer MoSe2 flakes for optoelectronic and energy harvesting systems.This work was supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding Contracts UIDB/04540/2020, UIDB/00100/2020 and UIDB/04650/2020. The author C. G. acknowledges a scholarship funded by the UIDB/04540/2020 contract. The author K. G. would like to thank the statutory grant (No. 8211104160) of Department of Quantum Technologies of Wroclaw University of Science and Technology

Exercise capacity and cardiac hemodynamic response in female ApoE/LDLR^{-/-} mice : a paradox of preserved V'O_{2max} and exercise capacity despite coronary atherosclerosis

We assessed exercise performance, coronary blood flow and cardiac reserve of female ApoE/LDLR-/- mice with advanced atherosclerosis compared with age-matched, wild-type C57BL6/J mice. Exercise capacity was assessed as whole body maximal oxygen consumption (V'O2max), maximum running velocity (vmax) and maximum distance (DISTmax) during treadmill exercise. Cardiac systolic and diastolic function in basal conditions and in response to dobutamine (mimicking exercise-induced cardiac stress) were assessed by Magnetic Resonance Imaging (MRI) in vivo. Function of coronary circulation was assessed in isolated perfused hearts. In female ApoE/LDLR-/- mice V'O2max, vmax and DISTmax were not impaired as compared with C57BL6/J mice. Cardiac function at rest and systolic and diastolic cardiac reserve were also preserved in female ApoE/LDLR-/- mice as evidenced by preserved fractional area change and similar fall in systolic and end diastolic area after dobutamine. Moreover, endothelium-dependent responses of coronary circulation induced by bradykinin (Bk) and acetylcholine (ACh) were preserved, while endothelium-independent responses induced by NO-donors were augmented in female ApoE/LDLR-/- mice. Basal COX-2-dependent production of 6-keto-PGF1α was increased. Concluding, we suggest that robust compensatory mechanisms in coronary circulation involving PGI2- and NO-pathways may efficiently counterbalance coronary atherosclerosis-induced impairment in V'O2max and exercise capacity

Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

What matters for life satisfaction among the oldest-old? Evidence from China

The world population is aging rapidly and the well-being of older people is of great interest. Therefore, this study investigates the determinants of life satisfaction among the oldest-old (i.e. individuals aged 80 or over) in China. Materials and methods We use the 2011/2012 Chinese Longitudinal Healthy Longevity Survey data (n = 6530) for this paper. Logistic regression is used to analyse the effects of socio-demographic, economic, health, instrumental activities of daily living, family and community factors on life satisfaction and depression among the oldest-old in China. Results Our analysis confirms the significance of many factors affecting life satisfaction among the oldest-old in China. Factors that are correlated with life satisfaction include respondent’s sex, education, place of residence, self-rated health status, cognitive ability (using mini mental state examination), regular physical examination, perceived relative economic status, access to social security provisions, commercialized insurances, living arrangements, and number of social services available in the community (p<0.05 for all these variables). Although life satisfaction is negatively associated with instrumental activities of daily living (β = -0.068, 95%CI = -.093—.043), and depression (β = -0.463, 95%CI = -.644—.282), the overall effect of self-rated health status is positive (p<0.001). This confirms the primacy of health as the determinant of well-being among the oldest-old. Conclusions Majority of the oldest-old in China rated their life satisfaction as good or very good. Our findings show that health and economic status are by far the most significant predictors of life satisfaction. Our finding on the primacy of health and relative income as determinants of well-being among the oldest-old, and the greater influence of self-rated health status over objective health measures is consistent with the findings of many past studies. Our results suggest that efforts should be directed at enhancing family support as well as health and social service provisions in the community to improve life satisfaction of older people

Fatores de influência no comportamento de compra de alimentos por crianças

A escolha alimentar nas sociedades contemporâneas passa, inevitavelmente, pelo comércio, pois o alimento constitui-se mercadoria que é consumida, assim como tantos outros bens e serviços. Atualmente muitas crianças já definem sozinhas suas escolhas alimentares, provocando a atenção tanto de empresas como de organizações preocupadas com sua nutrição. Utilizando o modelo BPM (Behavioral Perpective Model), criado por Foxall (2010), fundamentado na psicologia do consumidor e estruturado na tríplice contingência de Skinner, analisaram-se os fatores que influenciam crianças em seu comportamento de compra de alimentos. Tendo como sujeitos 175 alunos com idades compreendidas entre 10 e 12 anos, identificaram-se 35 variáveis que foram classificadas entre estímulos antecedentes (cenário ou histórico de aprendizado) e consequentes (reforço utilitário ou informativo) no comportamento de compra. Verificou-se que os estímulos reforçadores (consequentes) têm maior grau de importância para a decisão de compra de alimentos desses sujeitos do que os estímulos antecedentes, sendo que as consequências utilitárias são mais influentes do que as informativas. Conclui-se que os atributos dos produtos, como sabor e qualidade, têm maior influência na decisão de compra do que os estímulos ambientais, como as promoções e publicidade dos alimentos.Food choice in contemporary societies is, inevitably, a buying decision. Food is a product that is consumed, like so many other goods and services. Nowadays many children choose their food themselves, which attracts attention not only from companies that develop products and advertising for that segment, but also organizations concerned with their nutrition. This paper analyzed the factors that influence children's food purchasing behavior using the Perpective Behavioral Model (BPM) created by Foxall (2010), which in turn is based on consumer psychology and structured on Skinner's triple contingency. The subjects were 175 students between 10 and 12 years old. Thirty-five variables were identified and classified as antecedent stimuli (setting or learning history) or purchase reinforcers (utilitarian or informational reinforcement). It was seen that reinforcement stimuli (consequent stimuli) are more important to these children's decisions than antecedent stimuli, and that utilitarian consequences are more influential than informational consequences. It was concluded that product attributes such as taste and quality have greater influence on purchasing decisions than environmental stimuli such as promotions and food advertising

Separation of Individual Thermal Double-Donor Levels by Laplace Deep-Level Transient Spectroscopy

Thermal double donors (TDDs) are created by heat treatment of Czochralski‐grown Si at temperatures around 450 °C. A family of individual defects with very similar donor (TDDn0/+ with n = 0–16) and double‐donor (TDDn+/++) levels is known today. The close‐level positions of the individual TDDs result in broad and asymmetric deep‐level transient spectroscopy (DLTS) peaks. Herein, Laplace DLTS are used to study this asymmetry. Several well‐separated Laplace DLTS peaks are resolved in our samples. Metastable properties of the TDDs are taken as advantages to identify the double‐donor levels (++/+) of TDD0, TDD1, and TDD2