Linear magnetoresistance in compensated graphene bilayer

We report a nonsaturating linear magnetoresistance in charge-compensated bilayer graphene in a temperature range from 1.5 to 150 K. The observed linear magnetoresistance disappears away from charge neutrality ruling out the traditional explanation of the effect in terms of the classical random resistor network model. We show that experimental results qualitatively agree with a phenomenological two-fluid model taking into account electron-hole recombination and finite-size sample geometry

Social Jetlag Inhibits Exercise-Induced Adaptations in the Heart and Alters Markers of Mitochondrial Dynamics

Social jetlag (SJL), or the shifting of behavior and sleep times between weekdays and weekends, is a pervasive form of circadian rhythm disruption that affects nearly 70% of the population to some extent. The magnitude of SJL can be determined by the difference in the mid-sleep phase between weekends and weekdays. Higher levels of SJL have been associated with lower levels of cardiorespiratory fitness, and increased incidence of cardiometabolic disease, which may be due, in part, to mitochondrial dysfunction. However, no studies to date have evaluated the effects of long term SJL on cardiac mitochondrial dynamics. PURPOSE: To determine the effect of SJL on mitochondrial fission and fusion signaling in the heart, and if exercise protects the heart against SJL. METHODS: Male C57BL/6 mice (n = 40) were allocated to four groups (n = 10/group): 1) Control Light:Dark cycle, Sedentary (CON-SED), 2) Control Light:Dark cycle, Exercise (CON-EX), 3) SJL, sedentary (SJL-SED), or SJL, exercise (SJL-EX). SJL was implemented by delaying the LD cycle 4 hours on ‘Fridays,’ and advancing the LD cycle on Mondays. Exercise was provided ad libitum with a disc. Conditions persisted for 6 weeks at which point hearts were harvested for gravimetric analysis and western blotting of markers of mitochondrial dynamics. RESULTS: Exercise caused myocardial hypertrophy in both control and SJL LD conditions (Main Effect – EX, p \u3c 0.05), with no difference between CON and SJL conditions. We did not observe any significant differences in mitochondrial content (OXPHOS antibody cocktail, p \u3e 0.05), SJL decreased expression of mitochondrial fusion proteins MFN1 and OPA1 (Main Effect – SJL, p \u3c 0.05). Importantly, SJL inhibited exercise-induced increases in MFN2 (p \u3c 0.05), suggesting that SJL specifically ameliorates some exercise-induced adaptations in mitochondrial dynamics in the heart. CONCLUSION: These findings suggest that exercise induces adaptations in mitochondrial dynamics, potentially increasing mitochondrial function, and SJL may disrupt mitochondrial dynamics both in the sedentary and exercise trained states

TRACE ELEMENTS CONTENTS DYNAMICS IN WHOLE BLOOD IN CHILDREN WITH END STAGE RENAL DISEASE RECEIVING DIALYSIS

Homeostasis disorders in kidneys damage is accompanied by the accumulation or reduction of trace elements as a component of Chronic Kidney Disease (CKD) progression. The degree of trace elements misbalanced depends on the stage of CKD. The deep disorders are most common during renal replacement therapy (RRT), especially in children due to anatomic and physiological immaturity. Materials and methods: We investigated the 20 trace elements blood concentrations in 42 children with CKD V D depending on RRT duration used the technique of inductive coupled plasma mass-spectrometry (ICPMS). Results: There is detected significant increase of cobalt (in 3,80 times), cadmium (2,66), lead (2,44) and nickel (7,19) in patients with statistically weighty decrease in vanadium (1,49), chromium (1,62), arsenic (9,45), strontium (2,02), barium (5,29), rubidium (2,69 and zinc (1,46). It was found the increasing levels of aluminum, chromium and zinc in RRT duration enlargement (p<0,05). Conclusions: The course of CKD V D in children is accompanied with substantial and multidirectional changes in trace elements blood levels that characterized by a predominance of accumulation processes versus elimination depending the RRT duration

Comparative analysis of main clinical features in melanoma patients with and without sentinel lymph node biopsy

Introduction. Sentinel lymph node biopsy is fundamental in the treatment and prognosis of cutaneous malignant melanoma. This study aims to identify differences in baseline clinical characteristics and survival of patients with melanoma with and without a sentinel lymph node biopsy (SLNB) performed.  Material and methods. In 2018, a retrospective study of 151 patients with malignant melanoma (MM) was conducted. The patients were hospitalized at the Second Clinic of University Hospital — Pleven, from 2012 to 2017. The patients were divided into two groups: Group A included 58 (38.4%) patients with SLNB performed; Group B included 93 (61.6%) patients who did not undergo SLNB. A double-detection method was used while performing SLNB.  Results. The incidence of achromatic malignant melanoma is significantly higher in patients without SLNB (12 or 12.9%) than in patients with SLNB (2 or 3.4%) — c2 = 3.796, df = 1, p = 0.051. Of all 151 patients in the study, 46 died, representing 30.5% of patients with melanoma. The mortality rate was higher in the patients without SLNB (32.3% vs. 27.6% in Group A). However, the differences in the two groups are not statistically significant.  Conclusions. Patients with achromatic melanoma have significantly fewer sentinel lymph node (SLN) biopsies performed because of a late diagnosis. Most of our patients are diagnosed at a later stage when lymphatic metastases are already present, which leads to a significant increase in lymph node dissections performed. There is no significant difference in mortality and survival in the SLNB and non-SLNB groups

ЗНАЧЕННЯ ГІПЕРЕОЗИНОФІЛЬНОГО СИНДРОМУ В ДИФЕРЕНЦІЙНІЙ ДІАГНОСТИЦІ ТУБЕРКУЛЬОЗУ ЛЕГЕНЬ

У статті наведено дані про частоту і рівень еозинофілії у хворих, госпіталізованих в стаціонар із підозрою на туберкульоз легень. Збільшення еозинофілів констатовано у 24,9 % пацієнтів, які  потребували дообстеження з метою встановлення діагнозу та призначення адекватного лікування

Agreement of body adiposity index (BAI), bioimpedance analysis and ultrasound scanning in determining body fat

BACKGROUND: The steadily increasing number of people with obesity requires the development of simple and accurate methodological approaches to assess the absolute and relative amount of body fat mass. The body adiposity index (BAI) is one of the indices proposed to assess the body fat percentage. However, the comparison analysis of common methods, i.e., of bio-electrical impedance analysis and ultrasound scanning, and BAI was not performed for the Russian population.AIM: Comparison analysis of the body fat percentage estimates by bio-electrical impedance analysis, ultrasound scanning, and body adiposity index in the group of adult male and females.MATERIALS AND METHODS: An examination of healthy males and females from Moscow was conducted. Height, weight, waist and hip circumferences were measured. The body fat percentage was obtained by bio-electrical impedance analysis — BIA (ABC-02 Medas), ultrasound scanning — US (BodyMetrixTM, IntelaMetrix), and body adiposity index.RESULTS: 263 females and 134 males aged 18 to 73 years participated in the study. Correlation coefficients between BAI values and the body fat percentage obtained by BIA and US were 0.749 and 0.763 (p&lt;0.000), respectively. Comparison of body fat percentage measurements obtained by BAI, BIA and US showed the low agreement (ССС&lt;0.90) between BAI and other methods in pooled sample as well as in the female and male groups. Comparison of the US and BAI methods revealed higher level of agreement (ССС=0.84 [0.80–0.86]) and no systematic bias. Lower level of agreement was obtained in the group of males.CONCLUSION: Conducted study allows to conclude that, at the individual level, BAI is not an appropriate method for estimating the body fat percentage relatively to other indirect methods. However, all three methods can be used in the group of pooled males and females when testing at the population level

Attitudes towards vaccination against COVID-19 among athletes of Russian national teams in comparison with non-athletes aged 18 to 40

The purpose of this work was to study the attitude of the Russian population to vaccination against COVID-19. Vaccination attitudes in young adults were studied both in the general population and among those who are professionally involved in sports, since attitudes towards health and the initial level of physical resources are important for forming attitudes towards vaccination. A total of 2579 people aged 18 to 40 were examined. Of these, 2233 are from the general population, 346 are high performance athletes.Methods. This was a cohort cross-sectional study. A specially designed questionnaire was used, located on Internet resources 2 months after the start of mass vaccination in Russia.Results. In the group of elite athletes, there are significantly more people who consider vaccination unnecessary or treat it indifferently, and a smaller proportion of those who consider it useful or doubt its effectiveness as compared to the general population of the same age. Low adherence to vaccination may be associated with fear of potential complications. Among elite athletes, there are significantly more people who are seriously afraid of complications from vaccination — 143 (41.3 %), compared to the first group of respondents — 745 (33.4 %) (p &lt; 0.01, φ = 2.839). Probably, these concerns are related to the crucial importance of health and physical condition for professional athletes.Conclusions. It is advisable to develop recommendations for vaccination against COVID-19 for elite athletes, which will describe in detail the benefits of vaccination for athletes, possible side effects, their frequency and impact on the training process