Stress, development and mental health study, the follow-up study of Finnish TAM cohort from adolescence to midlife: cohort profile

PurposeThis cohort profile describes the Stress, development and mental health study (TAM), which is a cohort study investigating risk and protective factors as well as longitudinal associations regarding mental health and well-being from adolescence to midlife. This interdisciplinary cohort study operates, for example, in the fields of public health, social medicine, psychiatry and the life course perspective.ParticipantsIn 1981 (n=2242, 98.0% of the target population), 1982 (n=2191, 95.6%) and 1983 (n=2194, 96.7%) during school classes, surveys were conducted to all Finnish-speaking pupils (mostly born 1967) in the Tampere region in Finland. Participants of the school study at age 16 in 1983 (n=2194) comprised the base population for the longitudinal data and were followed-up using postal questionnaires in the years 1989, 1999, 2009 and 2019 at ages 22 (n=1656, 75.5% of the age 16 participants), 32 (n=1471, 67.0%), 42 (n=1334, 60.8%) and 52 (n=1160, 52.9%).Findings to dateThe self-reported questionnaires include information on physical and mental health (eg, depression and mood disorders, anxiety disorders), health behaviour and substance misuse (eg, alcohol, tobacco and exercise), socioeconomic conditions, psychosocial resources (eg, self-esteem), social relationships and support, life events, etc. The numerous studies published to date have examined mental health and various factors from several perspectives such as risk and protective factors, individual developmental paths (eg, trajectories) and pathway models (mediation and moderation).Future plansCurrent and future research areas include, for example, longitudinal associations between mental health (eg, depressive symptoms, self-esteem) and (1) substance use (alcohol and tobacco), (2) family transitions (eg, parenthood, relationship status) and (3) retirement. Next follow-up is planned to be conducted at the latest at age 62 in 2029. Before that it is possible to link the data with cause-of-death register.

Stress and its correlates among medical students in six medical colleges: an attempt to understand the current situation

Background Medical students encounter various stressors during their studies. The study aimed to assess stress levels, sources, and associated determinants among Sudanese medical students. An online questionnaire-based study was conducted among 617 undergraduate medical students of 6 different universities in Sudan. A 19-item questionnaire was utilized to assess stress sources, in addition to demographics, stress manifestations, and coping strategies. Results The overall prevalence of stress was 31.7% (p < 0.01). The main sources of stress were time pressure, heavy workload, fear of failure, and examination frequency. One-third of students indicated that they experienced at least one source of psychosocial- and teaching-related stress. Female medical students were more significantly stressed due to academics than males. Also, fourth- and fifth-year students were academically more stressed in comparison to the first-year students. Poisson regression analysis model showed that first-year students were less stressed than the final-year students in relation to academics (odds = 0.888, P = 0.003). Male medical students, across all study years, were far less stressed than females (odds = 0.901, P = 0.000153). Expectedly, ‘studying medicine by choice’ was associated with decreased odds for psychosocial stressors (odds = 0.885, P = 0.00781), and improved model-fit (chi-squared = 6.8952, P = 0.008643). Also, the year of study was a predictor of teaching-related stress development. Conclusions Female medical students were more stressed due to academics than males. On the other hand, final-year students were more academically stressed than first-year students. Female medical students were likely having stress related to academic stress development, while being first-year medical student was a predictor of not developing academic stress. Studying medicine by choice’ was associated with ability to cope against stress.

Study of hepatoprotective effect of bearberry leaves extract under insulin resistance in rats

The aim of our study was to evaluate the antidiabetic and hepatoprotective efficacy of dry extract from bearberry leaves enriched with arginine in dexamethasone induced IR. Materials and methods. IR was induced in rats by low dose intraperitoneally injections of dexamethasone. Dexamethasone-induced IR in rats was treated by bearberry leaves extract enriched with arginine. Thus, animals were randomized into several groups including intact animals and animals, which administered reference compounds and medications. The activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamine transferase (GGT) were determined in blood serum and liver homogenate, in addition, in blood serum we measured lactate dehydrogenase (LDH) activity and lactate level and glycogen content liver tissue. Also, for the purpose of our experiment, in liver tissue were determined: thiobarbituric acid reactive substances (TBARS), diene conjugates (DC), and reduced glutathione (GSH) content; and superoxide dismutase (SOD), glutathione peroxidase (Gpx), and catalase (CAT) activities. All indices were determined using generally accepted unified methods or commercially available kits. Results. Long-term dexamethasone administration led to an increase in AST, ALT and GGT overall activity in the liver homogenate and serum; this could be the result of increased permeability of hepatocyte plasma membranes, as well as their enhanced synthesis in the liver. Studied extract ameliorate these indices of liver injury. Evaluation of indices that reflected oxidative stress and the antioxidant system status in liver confirmed oxidative stress development in IR rats` liver. Administration of arginine enriched bearberry leaves extract decrease TBARS and DC content in liver tissue, at the same time, improve SOD, Gpx, and CAT activities and increase GSH content. Conclusions. Bearberry leaves dry extract enriched with arginine inhibit oxidative stress development, improve membrane integrity, and normalize some indices of carbohydrate metabolism, particularly glycogen content in liver and lactate level in blood.

Structure and Properties of Alkaline Cement and Concrete and Choice of Factors That Affect Service Life

The chapter covers the results of influence of changes in proportions between Portland cement and slag content, along with different quantities of alkali components in the cement systems on their heat of hydration and the effect of this during their hardening on character of internal stresses development and crack opening in concrete. The correlation between heat of hydration of the cements during hardening, strength of the concrete and stress development, and the dependence of this relationship on technical and technological factors were received. A new structure-based model for the durability (cracking) assessment of the alkaline cement concrete with heat of hydration and deformation properties during hardening as the input was received.

Strain Monitoring of an Aluminium Joint with an Optical System

The stresses distribution can be easily determined in the cross-section of the elements but in a joint, the distribution of stresses is more complicated. Its complexity is also increased if stiffeners are added to the joint and if the connecting bolts are not positioned in a regular configuration. An aluminium cantilever with a two bolts connection is experimentally tested to determine the real capacity. Stiffeners reduce the stress intensity in the connection, but they are prone to instability problems if they are subjected to compression. In order to determine the real stress development in the stiffeners, the Digital Image Correlation (DIC) technique was used. This technique determines the strains in the loaded parts which then can be equivalated to the stress distribution. The paper presents the stress development in the compressed stiffeners of an aluminium joint considering also improvement solution for increasing the bending capacity by reducing the instability parameters.

Thermal stress analysis of disc brake using analytical and numerical methods

This article presents study of the thermal stress development in brake disc and the associated life cycle of the disc. The thermal stress analysis of disc brake under the first brake application and the influences of thermal loads on stress development of the disc have been investigated. The temperature distribution was conducted as a function of disc thickness and braking time. The study was done on the disc brake of Sports Utility Vehicle with a model of DD6470C. Partial solution approach was used to solve analytical temperature distribution through the thickness. The model was done using representative areas of the disc exposed to high temperature whose distribution result was obtained as a function of disc thickness and braking time. The solutions of coupled thermal transient fields and stress fields were obtained based on thermal-structural coupled analysis. Based on the model developed for the study, the positions of high and low stress formations were investigated, and it has been observed that thermal stress and temperature gradient show similar behavior through the thickness of disc. Generally, high temperature and stress components were found on the rubbing surfaces of the disc.