On the effect of ballistic overflow on the temperature dependence of the quantum efficiency of InGaN/GaN multiple quantum well light-emitting diodes

The dependences of the quantum efficiency of InGaN/GaN multiple quantum well light-emitting diodes on the temperature and excitation level are studied. The experiment is performed for two luminescence excitation modes. A comparison of the results obtained during photo- and electroluminescence shows an additional (to the loss associated with Auger recombination) low-temperature loss in the high-density current region. This causes inversion of the temperature dependence of the quantum efficiency at temperatures lower than 220–300 K. Analysis shows that the loss is associated with electron leakage from the light-emitting-diode active region. The experimental data are explained using the ballistic-overflow model. The simulation results are in qualitative agreement with the experimental dependences of the quantum efficiency on temperature and current density

Clinical and laboratory characteristics of the patterns of chronic kidney disease in patients with type 2 diabetes

BACKGROUND: A growing body of evidence demonstrates increasing prevalence of normoalbuminuric chronic kidney disease (NA-CKD) in subjects with type 2 diabetes (T2D), while proportion of albuminuric pattern is decreasing. AIMS: To determine the clinical and laboratory parameters associated with different patterns of CKD in patients with T2D. METHODS: This observational, single-center, cross-sectional study included 360 patients with T2D duration ≥10 years. Patients with urinary albumin/creatinine ratio (UACR) <3 mg/mmol and estimated glomerular filtration rate (eGFR) >60 ml/min/1.73 m2 were classified as no-CKD group (n=89). Patients with UACR <3 mg/mmol and eGFR <60 ml/min/1.73 m2 formed NA-CKD group (n=111). Individuals with eGFR ≥60 ml/min/1.73 m2 and UACR mg/mmol ≥3 were recorded as albuminuric with preserved renal function (A-CKD–, n=87). Patients with eGFR <60 ml/min/1.73 m2 and UACR mg/mmol ≥3 mg/mmol were considered as albuminuric CKD group (A-CKD+, n=73). Urinary nephrin and podocin, the podocyte injury markers, and whey acidic protein four-disulfide core domain protein 2 (WFDC-2), a marker of tubulointerstitial involvement, was assessed by ELISA and compared to control (20 non-diabetic subjects). RESULTS: Age ≥65 years (p=0.0001), duration of T2D ≥15 years (p=0.0009), female sex (p=0.04), and therapy with diuretics (p=0.0005) were found as risk factors for NA-CKD. The risk factors for A-CKD were male sex (p=0.01), smoking (p=0.01), waist-to-hip ratio >1 (p=0.01) and HbA1c levels >8% (p=0.005). The duration of T2D ≥15 years (p=0.01) and the use of dihydropyridine calcium channel blockers (p=0.01) were associated with A-CKD+. In T2D groups, the urinary excretion of nephrin and podocin was increased (all p<0.001), more markedly in albuminuric individuals (p<0.01 vs. NA-CKD). WFDC-2 excretion was increased in men from all diabetic groups (p<0.05) and in women with decreased eGFR only (p<0.05 vs. the control and NA-CKD). CONCLUSIONS: The CKD patterns in T2D are heterogeneous according to their clinical and laboratory characteristics. The changes in the excretion of nephrin and podocin indicate the association of albuminuric patterns with podocyte injury. A decrease in eGFR in women with T2D is associated with an increase in urinary excretion of WFDC-2, tubulointerstitial fibrosis marker

INTERACTIONS BETWEEN ANXIETY LEVELS AND LIFE HABITS CHANGES IN GENERAL POPULATION DURING THE PANDEMIC LOCKDOWN: DECREASED PHYSICAL ACTIVITY, FALLING ASLEEP LATE AND INTERNET BROWSING ABOUT COVID-19 ARE RISK FACTORS FOR ANXIETY, WHEREAS SOCIAL MEDIA USE IS NOT

Background. The COVID-19 pandemic has substantially contributed to increased anxiety rates among the general population worldwide. Pandemic-related health anxiety and worries about getting COVID-19 can lead to generalized anxiety and anxiety somatization, which, together with insalubrious daily life habits, are risk factors of worsening somatic health in people with SARS-Cov-2 infection. Subjects and methods: The current study is a part of the COMET-G project (40 countries, n=55589; approved by the Ethics Committee of the Aristotle University of Thessaloniki), which represents an intermediate analysis of data collected anonymously via online links from a national sample of the Russian general population (n=9936, 31.09±12.16 y.o., 58.7% females) to estimate anxiety using STAI-S and self-reported changes in anxiety and life habits (physical activity, nutrition and weight, internet use, sleep) during the lockdown. All statistical calculations (descriptive statistics, between group comparisons using chi-square test, MANOVA, ANOVA, significant at p<0.05) were performed with IBM SPSS 27. Results: Overall STAI-S scores were 29+- 5.4, a subjective feeling of anxiety increase was reported in 40.3% of respondents (43.9% significantly > in females), worsening to clinical anxiety in 2.1% (2.4% > in females). 54.2% of respondents reported decreased physical activity, 33.1% gained weight, 72% used internet more often, 52.6% experienced worries related to the information about COVID-19 (56.8% > in females). 88% experienced worsened sleep quality, 69.2% stayed up until late, 23.2% took sleeping pills, and 31% had nightmares in which they felt trapped. To ANOVA, such life habits as reduced physical activity during the lockdown, increased time spent online, internet browsing about COVID-19, tendency to stay up late, use of sleeping pills and disturbing dreams with scenario of being trapped were significantly related to worsening of clinical anxiety. However, eating behaviour, weight changes, and social media use did not contribute to the clinical anxiety increase. Conclusions: Factors of decreased physical activity and sleep disturbances related to the lockdown, as well as excessive internet browsing for information about COVID-19, emerged as risk factors for increased anxiety, more notably in women than in men. Preventive measures should be targeted against relevant factors imparting anxiety in the vulnerable population

INTERACTIONS BETWEEN ANXIETY LEVELS AND LIFE HABITS CHANGES IN GENERAL POPULATION DURING THE PANDEMIC LOCKDOWN: DECREASED PHYSICAL ACTIVITY, FALLING ASLEEP LATE AND INTERNET BROWSING ABOUT COVID-19 ARE RISK FACTORS FOR ANXIETY, WHEREAS SOCIAL MEDIA USE IS NOT

Background. The COVID-19 pandemic has substantially contributed to increased anxiety rates among the general population worldwide. Pandemic-related health anxiety and worries about getting COVID-19 can lead to generalized anxiety and anxiety somatization, which, together with insalubrious daily life habits, are risk factors of worsening somatic health in people with SARS-Cov-2 infection. Subjects and methods: The current study is a part of the COMET-G project (40 countries, n=55589; approved by the Ethics Committee of the Aristotle University of Thessaloniki), which represents an intermediate analysis of data collected anonymously via online links from a national sample of the Russian general population (n=9936, 31.09±12.16 y.o., 58.7% females) to estimate anxiety using STAI-S and self-reported changes in anxiety and life habits (physical activity, nutrition and weight, internet use, sleep) during the lockdown. All statistical calculations (descriptive statistics, between group comparisons using chi-square test, MANOVA, ANOVA, significant at p<0.05) were performed with IBM SPSS 27. Results: Overall STAI-S scores were 29+- 5.4, a subjective feeling of anxiety increase was reported in 40.3% of respondents (43.9% significantly > in females), worsening to clinical anxiety in 2.1% (2.4% > in females). 54.2% of respondents reported decreased physical activity, 33.1% gained weight, 72% used internet more often, 52.6% experienced worries related to the information about COVID-19 (56.8% > in females). 88% experienced worsened sleep quality, 69.2% stayed up until late, 23.2% took sleeping pills, and 31% had nightmares in which they felt trapped. To ANOVA, such life habits as reduced physical activity during the lockdown, increased time spent online, internet browsing about COVID-19, tendency to stay up late, use of sleeping pills and disturbing dreams with scenario of being trapped were significantly related to worsening of clinical anxiety. However, eating behaviour, weight changes, and social media use did not contribute to the clinical anxiety increase. Conclusions: Factors of decreased physical activity and sleep disturbances related to the lockdown, as well as excessive internet browsing for information about COVID-19, emerged as risk factors for increased anxiety, more notably in women than in men. Preventive measures should be targeted against relevant factors imparting anxiety in the vulnerable population

Innovation in Training

The article deals with connection between the professional activities of specialists and innovation. It is shown that the professional level requires management skills and innovation. It is shown that an innovative model in education implies more innovative initiatives in the educational system, training methods and improving the quality of education

Remote Radio-Physical Harbingers of Drought in Steppes of the South of Western Siberia

Methods for remote sensing of the underlying surface in the microwave range based on moisture dependence of soil emissivity were successfully used in monitoring droughts and assessing water availability of the studied territories. Soil moisture influence on soil cover emissivity calibrated in units of the radio brightness temperature (TB) was studied. We used values of TB derived from SMOS satellite data. This paper presents the results of a comparative analysis of soil, meteorological conditions and physical characteristics of soils in the test territories of the Kulunda Plain. The experimental data were applied in computing trends of TB and physical temperature (T) described by linear dependencies. Volume fractions of water (W) in soil were calculated based on the satellite sensing data, the results of field studies and laboratory measurements of dielectric characteristics of soils. A map scheme of spatial distribution of W was constructed and the influences of snow cover, precipitation and surface wind velocity on drought were analyzed. The comprehensive analysis of remote, field and laboratory data suggest that the rate of change in the brightness temperature (dTBH/dD—up to 17 K per day), which characterizes the rate of fall in volume humidity of soil (ΔW—up to 0.009 cm3/cm3 per day), can be used as a short-term radio-physical harbinger of drought. An experimental dependence of the rate of change in radio brightness temperature on the rate of change in soil moisture was established

Diffusion of magnesium in LED structures with InGaN/GaN quantum wells at true growth temperatures 860-980°C of p-GaN

The results of an investigation of Mg diffusion in blue LED structures with InGaN/GaN quantum wells are presented for various growth temperatures of the p-GaN layer. The values of the diffusion coefficient estimated for true growth temperatures of 860, 910, and 980°C were 7.5·10–17, 2.8·10–16, and 1.2·10–15 cm2/s, respectively. The temperature values given in the work were measured on the surface of the growing layer in situ using a pyrometer. The calculated activation energy for the temperature dependence of the diffusion coefficient was 2.8 eV

Diffusion of magnesium in LED structures with InGaN/GaN quantum wells at true growth temperatures 860-980°C of p-GaN

The results of an investigation of Mg diffusion in blue LED structures with InGaN/GaN quantum wells are presented for various growth temperatures of the p-GaN layer. The values of the diffusion coefficient estimated for true growth temperatures of 860, 910, and 980°C were 7.5·10–17, 2.8·10–16, and 1.2·10–15 cm2/s, respectively. The temperature values given in the work were measured on the surface of the growing layer in situ using a pyrometer. The calculated activation energy for the temperature dependence of the diffusion coefficient was 2.8 eV