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Abstract Background The literature shows that social support is an important factor influencing health behaviors. This study aimed to explore the relationships and intrinsic pathways of social support, loneliness, economic income, and health behaviors among older adults during the Corona Virus Disease 2019 (COVID-19) pandemic, and to provide a theoretical basis for the implementation of health behaviors interventions for older adults. Methods A cluster-random-sampling survey was adopted within two towns in Dongguan, China. Demographic characteristics, social support, loneliness, economic income and health behaviors were measured. The Social Support Appraisals scale (SS-A), the ULS-8 Loneliness Scale, and the Self-rated abilities for health practice scale (SRAHPS) were used to measure social support, loneliness, and health behaviors in older adults, respectively. A moderated mediation model was built to examine the relationships among social support, loneliness, economic income, and health behaviors using the SPSS PROCESS 4.0 macro. We conducted bootstrapping of regression estimates with 5000 samples and a 95% confidence interval. Results 621 older adults completed the questionnaire. Most of the participants were female, accounting for 75.0%, and the average age was 81.11 years (SD = 8.11). The median (interquartile range) of the participants’ average monthly economic income was 800 (500–1000)RMB. The results of the mediation analysis showed that loneliness partly mediated the relationship between social support and health behaviors (B = 0.024, 95%CI: 0.007, 0.042), with the mediating effect accounting for 4.56% of the total effect. The moderation mediation analysis revealed a positive moderating role of economic income in the relationship between social support and loneliness (B = 0.114, 95%CI: 0.054, 0.174). Specifically, the relationship between social support and loneliness was found to be weaker for older adults with a high economic income compared to those with a lower economic income. Conclusion The provision of enhanced social support and the alleviation of loneliness among older adults during an epidemic can facilitate the development of healthy behaviours, particularly among those who are economically disadvantaged.

AbstractThis study was designed to explore the expression and the diagnostic value of vascular endothelial growth factor (VEGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) in pernicious placenta previa (PPP) combined placental accreta/increta. A total of 140 PPP patients were enrolled and divided into two groups: 56 patients with placenta accreta/increta (PA group), and 84 patients without placenta accreta/increta (non-PA group). In the same period, 46 pregnant women without PPP who had undergone caesarean section were selected as controls. The levels of VEGF and sFlt-1 in serum were detected by enzyme-linked immunosorbent assay. Diagnostic efficiency of VEGF and sFlt-1 in serum were evaluated by receiver operating characteristics curve. It was found that both VEGF and sFlt-1 had diagnostic value for PPP and placenta accreta/increta combined PPP. In addition, the levels of VEGF and sFlt-1 could be used to distinguish placenta accreta from placenta increta. VEGF was negatively correlated with sFlt-1 in PPP patients. In summary, the levels of VEGF and sFlt-1 could be used as auxiliary indicators to diagnose PPP and distinguish between placenta accreta and increta.KEY POINTSThe levels of VEGF and sFlt-1 could be used to distinguish placenta accreta from placenta increta.VEGF is negatively correlated with sFlt-1 in PPP patients.The levels of VEGF and sFlt-1 could be used as auxiliary indicators to diagnose PPP and distinguish between placenta accreta and increta.

Establishing a positive peer climate in elementary school classrooms is an important goal for educators because peer dynamics are thought to affect academic learning. Thus, it is important to (a) understand the relationship between children's peer dynamics and academic functioning, and (b) identify teacher practices that influence both peer processes and academic outcomes. In this pilot study, we explored whether specific teacher strategies that promote positive behaviors in children and positive peer dynamics influence children's better academic enablers, as well as whether they do so indirectly via improving peer sociometric ratings. Such teacher strategies may be particularly relevant for supporting children who demonstrate impairment in both social and academic domains, such as children at risk for attention-deficit/hyperactivity disorder (ADHD). Thus, we also examined whether these relationships differ for children with elevated ADHD symptoms and peer problems (i.e., target students), relative to classmates (i.e., non-target students). Participants were 194 children in the classrooms of 12 teachers (grades K-4) who participated in an open-trial pilot study of the school-based version of the Making Socially Accepting Inclusive Classrooms (MOSAIC) program. In the fall and spring of a school year, we assessed children's sociometric ratings received from peers, and academic enabler skills as rated by teachers. Throughout one academic year, we obtained assessments of teachers' use of MOSAIC strategies (observed and self-reported). Results showed that, after accounting for fall academic enablers, the teacher strategy of CARE time (involving one-on-one interaction with the student to build the teacher-student relationship) was positively associated with spring academic enablers. However, findings did not support the hypothesized indirect effect of peer sociometric ratings on the relationship between teacher strategy use and academic enablers, or the moderated indirect effect by target student status. Implications for future research and classroom interventions are discussed.

In view of the high dielectric constant of magnetic nanoparticles, this paper intends to use it as a new type of microwave absorbing medium to accelerate the microwave pyrolysis process of oily sludge. Microwave thermogravimetric reaction and pyrolysis product staged collection devices were established, respectively. The main stage of pyrolysis process of oily sludge was divided based on the thermogravimetric experiments. Mechanism was studied through the characteristics of pyrolysis products and reaction kinetics simulation. Experimental results showed that the addition of magnetic ZnFe2O4 particle did not change the microwave pyrolysis process of oily sludge and the pyrolysis efficiency could be improved. Pyrolysis process was divided into three stages, rapid heating and water evaporation stage (20~150 °C), light component evaporation stage (150~240 °C) and heavy component cracking stage (240~300 °C). Due to the addition of magnetic ZnFe2O4 particles, the content of C4~C12 increased by 3.5%, and the content of C18+ decreased by 4.1%, indicating that more recombinant components participated in the reaction pyrolysis to form light gas components. The kinetic analysis showed that the activation energy of oily sludge decreased by 36.49% and the pre-exponential factor decreased by 91.39% in stage III, indicating that magnetic nanoparticles had good catalytic activity.

The Arsenic (As) concentration in different tissues of maize was analyzed using a set of RIL populations derived from an elite hybrid, Nongda108. The results showed that the trend of As concentration in the four measured tissues was leaves>stems>bracts>kernels. Eleven QTLs for As concentration were detected in the four tissues. Three QTLs for As concentration in leaves were mapped on chromosomes 1, 5, and 8, respectively. For As concentration in the bracts, two QTLs were identified, with 9.61% and 10.03% phenotypic variance. For As concentration in the stems, three QTLs were detected with 8.24%, 14.86%, and 15.23% phenotypic variance. Three QTLs were identified for kernels on chromosomes 3, 5, and 7, respectively, with 10.73%, 8.52%, and 9.10% phenotypic variance. Only one common chromosomal region between SSR marker bnlg1811 and umc1243 was detected for QTLs qLAV1 and qSAC1. The results implied that the As accumulation in different tissues in maize was controlled by different molecular mechanism. The study demonstrated that maize could be a useful plant for phytoremediation of As-contaminated paddy soil, and the QTLs will be useful for selecting inbred lines and hybrids with low As concentration in their kernels.

With the emergence of "Internet + higher education," online teaching platforms have become increasingly important, particularly for practical teaching courses. The study of oil and gas storage and transportation is a fundamental and essential course for students in this major. In light of the issues related to limited space, lack of openness, and low student enthusiasm for traditional experimental teaching methods, an online experimental teaching platform for oil and gas storage and transportation was developed. This platform is based on the WeChat mini-program and follows the principles of cross-platform computability, user friendliness, and low investment. Its aim is to explore effective learning models for mobile devices. This study compares and analyzes the differences in classroom effects before and after the implementation of the WeChat learning platform. The study examines the design of the platform, teaching session cases, and the analysis of application effects. The research utilizes questionnaires and statistical data as research methods. The results indicate that the WeChat online teaching platform has significantly improved the enthusiasm and learning outcomes of students in the independent learning of experimental courses. It has received high recognition from both teachers and students and has greatly enhanced the quality of teaching. This has considerable potential for further promotion. [ABSTRACT FROM AUTHOR]

In this study, the flow properties of singlephase liquid in circular pipes with different wettabilities at different flow regions were simulated by FLUENT software. The slip effect of wetting interface was characterized by directly setting the slip boundary condition on wall. The effect of apparent contact angle on the pressure drop and frictional resistance of #26 white oil in laminar flow was analyzed. The effects of pipe diameter and surface wettability on the flow property of tap water in turbulent flow were studied. The characteristics of flow field and velocity distribution under different flow regions were discussed respectively. The verification of experimental data showed that the numerical simulation method and boundary conditions were reliable and accurate. The simulation results showed that the pressure drop of white oil decreased with the increase of contact angle in the same pipe diameter. The frictional resistance of white oil was negatively correlated with the slip velocity on wall, that is, the greater the slip velocity, the smaller the frictional resistance. In different pipe diameters, the greater the increase of contact angle and the smaller the pipe diameter, the more obvious the influence of surface wettability on the pressure drop of liquid. [ABSTRACT FROM AUTHOR]

In this work, the effects of combining a surfactant/alkali on the stability of heavy-oil-in-water emulsions are analyzed by use of bottle testing, spinning-drop interfacial-tension (IFT) meters, microscopes, conductivity meters, zeta-potential analyzer Turbiscan laboratory expert stabilizer, and Anton Paar rheometer. The experimental results showed that the formulated surfactant (BS-12 and OP-10) had an optimal mass ratio (1:2), and the water-separation rates initially decreased sharply as the concentrations of the surfactant increased, before decreasing moderately until reaching a minimum value. The formulated alkali solution exerted a positive synergistic effect in tandem with the surfactant at low alkali concentrations. In this way, an increasing number of petroleum soaps are produced by reactions between the alkali solutions and the active components in heavy crude oil. However, the effect was reversed at high alkali concentrations, where the compression of the alkali on the electric double layer was more significant. Images of the emulsions taken with a microscope showed that the sizes of the oil droplets were the smallest when the alkali concentration was 0.2% and mass ratio of NaOH and TEA (triethanolamine) was 1:1, which indicated that the amount of petroleum soap produced reached the maximum at this point. In addition, TEA, as a type of surface-active molecule, can form cross-multiple adsorption and hydrogen-bonding structure with surfactant and petroleum soap at the water/oil interface. When the oil/water ratio was 7:3, the water-separation rate reached its lowest point 5.33% for 3 hours. In addition, the emulsion stabilized by the surfactant and the compositional alkali possesses salt tolerance and temperature resistance. When the concentration of the bivalent salt (CaCl2 and MgCl2) increased to 0.01mol·L-1, the water-separation rate was less than 20%, and when the temperature increased from 30 to 60°C, the growth of back-scattering (BS) value was less than 2%. [ABSTRACT FROM AUTHOR]

A laboratory study was conducted to remediate petroleum contaminated soils using microwave irradiation, and the traditional method of electric heating was also used for comparison purpose. The feasibility of the microwave irradiation method was evaluated in aspects of the reaction time, petroleum removal efficiency and energy consumption level. Meanwhile, the impacts of microwave irradiation mode and soil conditions on petroleum removal efficiency were also investigated, with a thermodynamic model of soils specifically developed. The results showed that microwave irradiation was better than the traditional heating method in remediating petroleum contaminated soils with less energy consumed. Also, microwave irradiation time, microwave power, soil moisture content and soil petroleum content had all imposed significant impacts on the remediation efficiency, and the results obtained from the model were basically consistent with the experiment results. Therefore, the findings from this study are of significance in real-world applications of microwave irradiation for the remediation of petroleum contaminated soils. [ABSTRACT FROM AUTHOR]

Deepwater surface BOP (surface blowout prevention, SBOP) drilling differs from conventional riser drilling system. To analyze the dynamic response of this system, the riser-conductor was considered as a beam with varied cross-sections subjected to loads throughout its length; then an equation of motion and free vibration of the riser-conductor string for SBOP was developed. The finite difference method was used to solve the equation of motion in time domain and a semianalytical approach based on the concept of section division and continuation was proposed to analyze free vibration. Case simulation results show that the method established for SBOP system natural frequency analysis is reasonable. The mode shapes of the riser-conductor are different between coupled and decoupled methods. The soil types surrounding the conductor under mudline have tiny effect on the natural frequency. Given that some papers have discussed the response of the SBOP riser, this work focused on the comparison of the dynamic responses on the wellhead and conductor with variable conditions. The dynamic lateral displacement, the bending moment, and the parameters’ sensitivity of the wellhead and the conductor were analyzed.

Using a finite element model, this paper investigates the torsional vibration of a drill string under combined deterministic excitation and random excitation. The random excitation is caused by the random friction coefficients between the drill bit and the bottom of the hole and assumed as white noise. Simulation shows that the responses under random excitation become random too, and the probabilistic distribution of the responses at each discretized time instant is obtained. The two points, entering and leaving the stick stage, are examined with special attention. The results indicate that the two points become random under random excitation, and the distributions are not normal even when the excitation is assumed as Gaussian white noise.