No abstract

Longitudinal studies of aging concerning individuals with comparable lifestyle, diet, health profile, socioeconomic status, and income remain extraordinarily rare. The purposes of our ongoing project are as follows: (i) to collect extensive data on biological and medical aspects of aging in the Polish population, (ii) to determine factors affecting the rate and course of aging, (iii) to understand how aging unfolds as a dynamic and malleable process in ontogeny, and (iv) to find novel predictors of longevity. Our investigation followed 142 physically healthy asylum inmates, including 68 males and 74 females, for at least 25 years from the age of 45 years onward. Cross-sectional assessment involved 225 inmates, including 113 males and 112 females. All the patients lived for a very long time under similar and good environmental conditions at the hospital in Cibórz, Lubuskie Province. They maintained virtually the same daily schedule and lifestyle. The rate and direction of changes with age in selected anthropometric and physiological traits were determined using ANOVA, t-test, and regression analysis. There were sex differences in the rate and pattern of age-related changes in certain characteristics such as relative weight, red blood cell count, monocyte count, thymol turbidity value, systolic blood pressure, and body temperature. Body weight, the body mass index (BMI), and total bilirubin level increased with advancing age, while body height decreased with age in both sexes. In conclusion, the aging process was associated with many regressive alterations in biological traits in both sexes but the rate and pattern of these changes depended on biological factors such as age and sex. There were only few characteristics which did not change significantly during the period under study. On the basis of comparison between the pattern of longitudinal changes with aging and the pattern of cross-sectional changes with age in the analyzed traits, we were able to predict which pattern of changes is associated with longer lifespan.

The connection between the rate of height loss in older people and their general health status has been well documented in the medical literature. Our study was aimed at furthering the characterization of this interrelationship in the context of health indices and mortality in a hospitalized population of Polish adults. Data were collated from a literature review and from a longitudinal study of aging carried out in the Polish population which followed 142 physically healthy inmates, including 68 men and 74 women, for at least 25 years from the age of 45 onwards. Moreover, cross-sectional data were available from 225 inmates, including 113 men and 112 women. These subjects were confined at the same hospital. ANOVA, t-test, and regression analysis were employed. The results indicate that the onset of height loss emerges in the fourth and five decade of life and there is a gradual acceleration of reduction of height at later stages of ontogeny in both sexes. Postmenopausal women experience a more rapid loss of height compared with men. The individuals who had higher rate of loss of height (≥3 cm/decade) tend to be at greater risk of cardiovascular events and all-cause mortality. In conclusion, our findings suggest that a systematic assessment of the rate of loss of height can be useful for clinicians caring for elderly people because of its prognostic value in terms of morbidity and mortality.

No abstract

The presently observed rapid increase in photovoltaic (PV) micro-installation connections to low-voltage networks, resulting from numerous financial support programmes, European Union (EU) energy policy and growing social awareness of environmental and economic issues, raise the question if PV inverters widely available in EU market fulfil the numerous technical requirements specified in European and Polish regulations. The paper presents the results of an experimental study carried out on three PV Inverters widely available in the EU in accordance with the EU network code NC RfG, standard EN 50549-1:2019 and internal Polish distribution system operators’ (DSOs’) regulations, governing PV inverter cooperation with the low-voltage distribution network. The laboratory test stand scheme and its description are presented. In each test, at least one of the inverters encountered issues, either with the operation in required frequency ranges (one PV inverter), activating reactive power control modes (all three PV inverters), maintaining required power generation gradient after tripping (one PV inverter) or under-voltage ride through immunity (one PV inverter). The obtained results have shown that all tested PV inverters did not meet requirements that are the key to maintaining reliable and safe operation of transmission and distribution electrical networks.