longitudinal heat conduction is an important parameter in the cryogenic field, especially in cryogenic heat exchangers. in the present work, the parasitic effect of tube wall longitudinal heat conduction on temperature measurement has been studied in cryogenic laminar hydrogen flow. the effects of various parameters such as wall cold end temperature, wall thermal conductivity, gas volumetric fl...

A method is presented to partially transfer nuclear spin polarization from one isotope S to another isotope I by the way of heteronuclear spin couplings, while minimizing the loss of spin order to other degrees of freedom. The desired I spin polarization to be detected is a design parameter, while the sequence of pulses at the two Larmor frequencies is optimized to store the greatest unused S s...

The paper presents the first known longitudinal study of the relationship between loneliness, depressive symptoms, and suicide ideation in adolescence, in a stratified sample of high school students (Time 1 N = 1009; 57 % female; Time 2 N = 541; 60 % female). Cross-lagged structural equation modeling indicated that depressive symptoms led to more loneliness across time, whereas loneliness did n...

BACKGROUND Adolescents' sleep duration and subjective psychological well-being are related. However, few studies have examined the relationship between sleep duration and subjective psychological well-being longitudinally across adolescence - a time of profound biological and psychosocial change. The aim of this longitudinal study was to investigate whether shorter sleep duration in adolescents...

conclusions alterations in consumption of whole grains, vegetables, and added sugars are associated with body weight change, suggesting that it could be helpful in weight control. results in men, weight loss was significantly predicted only by decreased intake of added sugars (or: 2.21, 95% ci: 1.06-4.63). in women, weight gain was significantly predicted by decreased intake of whole grains (or...

background menarche is considered as a milestone in the women’s reproductive life. most existing studies on factors influencing menarcheal age had cross-sectional designs and their finding were controversial. objectives we aimed to determine some factors affecting the age at menarche in a cohort study with an average of ten-year follow-up; the study was conducted within the framework of tehran ...