Interaction between adolescent sleep rhythms and gender in an obese population

BACKGROUND The obesity rate of adolescents is gradually increasing,which seriously affects their mental health,and sleep plays an important role in adolescent obesity.AIM To investigate the relationship between sleep rhythm and obesity among adolescents and further explores the interactive effect of sleep rhythm and gender on adolescent obesity,providing a theoretical basis for developing interventions for adolescent obesity.METHODS Research data source Tianjin Mental Health Promotion Program for Students.From April to June 2022,this study selected 14201 students from 13 middle schools in a certain district of Tianjin as the research subject using the convenient cluster sampling method.Among these students,13374 accepted and completed the survey,with an effective rate of 94.2%.The demographic data and basic information of adolescents,such as height and weight,were collected through a general situation questionnaire.The sleep rhythm of adolescents was evaluated using the reduced version of the morningness-eveningness questionnaire.RESULTS A total of 13374 participants(6629 females,accounting for 49.56%;the average age is 15.21±1.433 years)were analyzed.Among them,the survey showed that 2942 adolescent were obesity,accounting for 22%and 2104 adolescent were overweight,accounting for 15.7%.Among them,1692 male adolescents are obese,with an obesity rate of 25.1%,higher than 18.9%of female adolescents.There is a statistically significant difference between the three groups(χ2=231.522,P<0.000).The obesity group has the smallest age(14.94±1.442 years),and there is a statistical difference in age among the three groups(F=69.996,P<0.000).Obesity rates are higher among individuals who are not-only-child,have residential experience within six months,have family economic poverty,and have evening-type sleep(P<0.05).Logistic regression analysis shows a correlation between sleep rhythm and adolescent obesity.Evening-type sleep rhythm can increase the risk of obesity in male adolescents[1.250(1.067-1.468)],but the effect on female obesity is not remarkable.Further logistic regression analysis in the overall population demonstrates that the interaction between evening-type sleep rhythm and the male gender poses a risk of adolescent obesity[1.122(1.043-1.208)].CONCLUSION Among adolescents,the incidence of obesity in males is higher than in females.Evening-type sleep rhythm plays an important role in male obesity but has no significant effect on female obesity.Progressive analysis suggests an interactive effect of sleep rhythm and gender on adolescent obesity,and the combination of evening-type sleep and the male gender promotes the development of adolescent obesity.In formulating precautions against adolescent obesity,obesity in male adolescents with evening-type sleep should be a critical concern.

Modeling of deformation energy at elevated temperatures and its application in Mg-Li-Al-Y alloy

To control the superplastic flow and fracture and examine the variation in deformation energy,the stress and grain size of Mg-7.28Li-2.19Al-0.091Y alloy were obtained using tensile testing and microstructure quantification,and new high temperature deformation energy models were established.Results show that the grain interior deformation energy increases with increasing the strain rate and decreases with increasing the temperature.The variation in the grain boundary deformation energy is opposite to that in the grain interior deformation energy.At a given temperature,critical cavity nucleation energy decreases with increasing strain rate and cavity nucleation becomes easy,whereas at a given strain rate,critical cavity nucleation energy increases with increasing temperature and cavity nucleation becomes difficult.The newly established models of the critical cavity nucleation radius and energy provide a way for predicting the initiation of microcrack and improving the service life of the forming parts.

Structural and mechanical properties of 7075 alloy strips fabricated by roll-casting in a static magnetic field

The influences of a 0.2 T static magnetic field on the microstructure of 7075 aluminum alloys sheets produced with a twin-roll continuous caster at 675℃ were investigated in this paper. Under a uniform magnetic field, the primary dendrites were refined and tended to be equiaxed. The microstructure consisted of an intermediate case between dendritic and equiaxed grains. Moreover, the use of an external static field in the twin-roll casting process can reduce heat discharge, resulting in a decrease in undercooling, and may also account for the abatement of segregation bands. In addition, the static magnetic field effectively improved the solute mixing capacity, and the added atoms more easily diffused from precipitates to theα-Al matrix, which resulted in an increase in the mechanical properties of the rolled sheets. Specimens prepared both in the presence of a static magnetic field and in the absence of a static magnetic field exhibited brittle-fracture characteristics.

Texture evolution and mechanical properties of Al-Mg-Si alloys at different intermediate annealing temperatures

Intermediate annealing treatment produces different effects on the state of particles in Al-Mg-Si alloy sheets,thereby affecting their recrystallization textures and formability.To improve the formability of the sheets,the effects of different intermediate annealing temperatures on the texture evolution and mechanical properties of these sheets for automotive applications were studied using optical microscope(OM),scanning electron microscope(SEM) and tensile tests.The results reveal that intermediate annealing temperature has a significant influence on the recrystallization textures and average plastic strain ratio(r).After solution treatment,all the alloy sheets possess similar recrystallization texture components comprising of cubeND {100}<310> and P {011}<122> orientations,whereas a characteristic strong cube-oriented {100} <001>texture is observed only in the alloy annealed at a temperature of 380℃.However,in comparison with the alloy not annealed,and the alloy annealed at 550℃,the alloy annealed at 380℃ possesses a lower average r value.Furthermore,the relationship between textures and r value was analyzed by using the Taylor full constraints model in this study.

Distribution uniformity of added elements in twin-roll cast Al–Zn–Mg–Cu alloy by multi-electromagnetic fields

The micromorphology and the concentration o massive precipitates produced by twin-roll casting(TRC processes without and with multi-electromagnetic fields fo Al–Zn–Mg–Cu alloy at 670 °C were investigated in detai by means of optical microscopy(OM) and electron probe micro analyzer(EPMA). The results clearly show tha under a 0.2 T static magnetic field, the macro-segregation bands are remarkably alleviated according to the order o uniform static magnetic field, half-wave oscillating elec tromagnetic field as well as alternating oscillating elec tromagnetic field, as compared with the non-field TRC process(B = 0). Moreover, under the alternating oscillat ing electromagnetic TRC process, almost all segregation bands disappear. Additionally, through the observation on a smaller scale, the netlike precipitates elongated and broken by electromagnetic force, and replaced by numerous bulk depositions. EPMA analysis shows that the added atoms are diffused from deposition to a(Al) matrix, resulting in that the solute concentration in and around the precipitates is tending toward uniformity and stability.

Automated microfluidic chip system for radiosynthesis of PET imaging probes

Positron emission tomography(PET)is a powerful non-invasive molecular imaging technique for the early detection,characterization,and"real-time"monitoring of disease,and for investigating the efficacy of drugs(Phelps,2000;Ametamey et al.,2008).The development of molecular probes bearing shortlived positron-emitting radionuclides,such as 18F(half-life 110 min)or HC(half-life 20 min),is crucial for PET imaging to collect in vivo metabolic information in a time-efficient manner(Deng et al.,2019).

The importance of vitellogenin receptors in the oviposition of the pond wolf spider, Pardosa pseudoannulata

Vitellogenin receptor(VgR)is crucial for vitellogenin(Vg)uptake by oocytes.VgR is less known in Arachnida,especially in spiders.Different from only one VgR in an arthropod species,two VgRs,VgR-1 and VgR-2,were found in the pond wolf spider,Pardosa pseudoannulata.Both VgRs had the typical domains of the low-density lipoprotein receptor family except for the absence of the ligand-binding domain 1 in VgR-2.Spatiotemporal expression profiles showed that two VgR genes were consistently highly expressed in females and their ovaries,but VgR-1 was 48-fold that of VgR-2 in ovaries.The transcriptional level of VgR-1 was significantly downregulated by RNAi,but it did not work for VgR-2 although several trials were performed.Vg-1 and Vg-2 might be the ligands of VgR-1 because their expressions were also decreased in the dsVgR-1-treated females.Silencing VgR-1 prolonged the pre-oviposition period by 56 h.The expression of VgRs and Vgs were upregulated by juvenile hormones(JHs),which suggested that JHs were the essential factors to vitellogenesis in the spider.The present study revealed the importance of VgR-1 in the spider oviposition,which will improve the understanding on VgR physiological functions in spiders.

Improvement of Bonding Strength of Horizontal Twin-Roll Cast Steel/Aluminum Clad Sheet by Electromagnetic Fields

Electromagnetic field is an available online method to increase bonding strength of clad sheet manufactured by horizontal twin-roll casting （HTRC）. In this paper, an electric current pulse （ECP） and a complex field （static magnetic field （SMF） together with ECP） are exerted during HTRC of steel/aluminum clad sheet. The produced clad sheet has good appearance, and no visible defects exist at the bonding interface. The inter-diffusion zone at Fe/A1 interface in ECP and SMF＋ECP sheets is 3 and 4 μm, respectively, and the latter increases slightly compared with that in non-field sheet. The average peel strengths （APS） of ECP and SMF＋ECP sheet are 14 and 21 N/mm, respectively, which increase by 2 and 9 N/mm compared with 12 N/mm of non-field sheet. The APS increment in SMF＋ECP sheet is resulted from the increment of interface bonding spots and the enhancement of inter-diffusion zone width.