The push-out test was carried out in order to study the shear performance of perfobond ribs (PBL) and puzzle (PZ) shape composite dowel shear connectors which are used in corrugated steel-concrete ...composite bridge decks. By considering the influencing factors of transversal reinforcement, elliptical holes and bonding friction forces, eight specimens were designed and prepared. The load-slip curves were obtained, and the static mechanical properties, including bearing capacity, slip, shear stiffness, and ductility factor, were analyzed. The formula of bearing capacity and load-slip curve were proposed. The results showed a clear deformation of the transversal reinforcement of both the two types of shear connectors. The dominating failure mode of both the shear connectors was the double plane shearing of the concrete dowel. The load-slip curves of the two types of shear connectors followed the same trend. The PZ shape composite dowel performed better in ultimate bearing capacity, ductility, and shear stiffness than the PBL shear connector. Elliptical holes in a PZ shape composite dowel significantly increased the ultimate bearing capacity. The shear stiffness increased with transversal reinforcement and reduced with elliptical holes. For PBL shear connectors, the strain change in the C1 area near the loading point was most apparent. While, the A1 and B1 areas were stress concentration locations for PZ shape composite dowel shear connectors. The two formulas were in good agreement with the test results.
Abstract
Background
Studies had shown that social integration was related to the utilization of medical services. Few studies investigated the relationship between social integration and medical ...returns among the elderly. None research had ever clarified the effect of social integration on medical returns among the migrant elderly following children (MEFC) to new cities. This study aimed to explore the association between social integration and medical returns among the MEFC in Jinan, China.
Method
This cross-sectional study included 627 MEFC in Jinan China. Social integration was evaluated by economic integration, acculturation, and identification. Medical return was assessed by asking the subjects whether go back to hometown to use the medical services when ill. Chi-squared test and multivariable logistic regression were applied to analyze the association between social integration and medical returns of the MEFC.
Results and discussion
It was found that 20.3% of the MEFC had a medical return. As for social integration, those who had not joined local medical insurance (OR = 3.561, 95% CI 1.577–8.039,
p
= 0.002) and were unwilling to stay for a long time (OR = 2.600, 95% CI 1.620–4.174,
p
= 0.001) were more likely to have a medical return. Furthermore, our findings showed that the MEFC who were accompanied by one or more (OR = 1.568, 95% CI 1.027–2.392,
p
= 0.037) were more likely to have a medical return than those who migrated alone.
Conclusion
Negative relationship between social integration and medical returns was found among the MEFC, which means the better social integration of the MEFC would generally have fewer medical return, as well as the better refunding connections of the medical insurance between the current residence and hometown.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This study assessed university students' knowledge and precaution practices of Novel Coronavirus (COVID-19) in South Korea, China, and Japan, and investigated their depressive states during the ...pandemic. This cross-sectional survey collected data from 821 respondents, using an anonymous online questionnaire designed by the Yonsei Global Health Center, from 23 March to 20 April 2020, which included socio-demographic questions, knowledge and perceptions of COVID-19, preventative practices, and the Patient Health Questionnaire-9 (PHQ-9) scale to assess mental health. High proportions of respondents showed good knowledge of the transmission pathways and information related to COVID-19. Contact history as well as concerns about family members and the disease showed statistically significant distinctions by nationality and gender. On the whole, all participants reported good levels of preventative practices. The Chinese group reported the highest preventative practice scores; and females scored higher than males. Moreover, the Japanese group showed the most severe depressive states; overall, females experienced more severe depression than males. Thus, authorities should especially emphasize the importance of COVID-19 precautions to males. Educational departments and health authorities should observe the mental health of university adults during the pandemic and plan interventions to improve it.
ObjectivesAs the fast population ageing in the past few decades, China has also witnessed an increase in the number of migrant elderly following children (MEFC). This study aims to examine the ...relationship between MEFC’s social support, smartphone usage and loneliness in Jinan, China.DesignCross-sectional survey.SettingShandong Province, China.ParticipantsThe participants were 656 MEFC aged 60 years or above.Primary and secondary outcome measuresLoneliness was measured by an eight-item version of the University of California Los Angeles Loneliness Scale (ULS-8). A t-test and one-way Analysis of Variance (ANOVA) were conducted to compare the level of loneliness across different sociodemographic variables, social support indicators and smartphone usage indicators. Structural equation modelling was used to validate the association between the above variables.ResultsThe MEFC’s mean score on the ULS-8 was 12.82±4.05, indicating a relatively lower level of loneliness. It was found that social support and smartphone usage exerted negative effects on loneliness of the MEFC, and the standardised direct effects were −0.165 (95% CI −0.257 to −0.070) and −0.094 (95% CI −0.180 to −0.003), respectively. Social support was found to be positively associated with smartphone usage of the MEFC, and the standardised direct effect was 0.147 (95% CI 0.052 to 0.246).ConclusionsThe loneliness of the MEFC was relatively low and was clarified to be negatively associated with social support and smartphone usage. Effective intervention measures on social support and smartphone usage to alleviate loneliness among the MEFC in China were recommended based on this study.
Particle swarm optimization and neural network algorithm are very novel computer intelligent algorithms, and with the development of computer technology, these algorithms have been applied to various ...fields. Because of obvious advantages, in this paper, the particle swarm optimization and neural network algorithms were applied to English teaching. English is an international language, and the teaching of English is the basis of learning English. Therefore, the study of English teaching can promote the process of internationalization, which is more convenient to spread the knowledge of different countries, and it also makes the economic trades between different countries go on faster. Therefore, the use of particle swarm optimization in the training of the neural network and its application in English teaching are subjects that are worthy of study. In this paper, the current research status at home and abroad was firstly analyzed, and the shortcomings of the traditional algorithms were improved; then, the improved algorithm was applied to the study of English teaching; finally, the effectiveness of the algorithm was verified by the experiment simulation.
Abstract
Background
With the accelerated urbanization and aging population in China, more and more migrant older with children (MOC) moved to new cities. Previous studies mainly explored the ...acculturation of MOC, yet few focused on the health conditions of this vulnerable group. This study aimed to investigate the effects of oral health and social support on health-related quality of life (HRQOL) of MOC in Weifang, China.
Method
This study was a cross-sectional study and participants were selected by multi-stage cluster random sampling in Weifang, China. The HRQOL was assessed via the 12-item Short-Form Health Survey (SF-12) which included the mental component summary (MCS) and the physical component summary (PCS). The oral health was evaluated by the Geriatric Oral Health Assessment Index (GOHAI). The social support was administered using the Social Support Rating Scale (SSRS). Descriptive analysis was used to describe participants’ sociodemographic variables, oral health and social support. Univariate analysis and binary logistic regression analysis was used to investigate the association between the social support, oral health and HRQOL.
Results and discussion
It was found that 25.0% of MOC were defined as MCS poor and PCS poor, respectively. Those participants with average and low monthly household income compared to those around them, average and poor oral health, and low levels of social support were more likely to have poor PCS. Those with temporary residence permits, fair and poor oral health, and medium and low levels of social support were more likely to report poor MCS.
Conclusion
Results indicated that better social support and oral health led to higher HRQOL of MOC. Implications for the government, communities and families of MOC were given to improve their HRQOL.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
There is an urgent need for suitable nitrogen nutrition models for Southwest China, which take into account nutritional differences at the cultivar level, to provide scientific guidance for ...cultivar-specific fertilizer applications during maize production. In this study, the nitrogen-efficient maize cultivar Zhenghong 311 and the nitrogen-inefficient maize cultivar Xianyu 508 were used in a three-year field experiment and a 2-year field pot experiment with nitrogen application rates ranging from 0 to 450 kg·hm
−2
to construct a critical nitrogen dilution curve model for each maize cultivar. The usefulness of this model to diagnose nitrogen status and evaluate maize fertilization needs was subsequently analyzed. We found that the critical nitrogen concentration in maize aboveground tissues was a power function of the biomass, described by the equations N
c
= 26.126 W
−0.292
and N
c
= 25.826 W
−0.302
for ZH 311 and XY 508 cultivars, respectively. The fitting degree of these equations was significant or highly significant, demonstrating the suitability of these models to diagnose N deficiency and fertilization needs in maize plants grown in the hilly areas of central Sichuan. A very significant linear positive correlation between the nitrogen nutrient index (NNI) and nitrogen concentration in the aboveground tissues was detected. Based on this, we calculated the nitrogen concentration (Nt) for an NNI equal to 1 at different maize growth stages in both cultivars and observed that the Nt value can be used as a reference index for nitrogen nutrition diagnosis. Additionally, we found a highly significant quadratic convex function relationship between the NNI (
y
) and the nitrogen fertilizer level (
x
). The following regression equations were derived for these maize cultivars with the data obtained from each growth period along five consecutive years (2011–2015):
y
ZH 311
= − 0.000005
x
2
+ 0.003074
x
+ 0.553206 (
R
2
= 0.5432**) and
y
XY 508
= − 0.000004
x
2
+ 0.002914
x
+ 0.512555 (
R
2
= 0.6279**). For an NNI value equal to 1, the nitrogen application level required was 224.07 kg·hm
−2
for ZH 311 and 283.01 kg·hm
−2
for XY 508, indicating that the suitable application rate for the nitrogen-efficient cultivar is lower than that for the nitrogen-inefficient cultivar. Our experimental data reinforce the concept that selecting nitrogen-efficient maize cultivars is an effective technical measure to reduce nitrogen input needs and increase nitrogen use efficiency during maize production.
College students, considered to be the driving force of society, are highly vulnerable to COVID-19. At a time when facing a new pandemic wave in 2022, China's policy was in contrast with that of ...Korea. We investigated the phobia levels of international Chinese college students studying in Korea.
This study aimed to investigate the relationship between the frequency of use and trust of information sources, and COVID-19 phobia (C19P) among Chinese college students studying in Korea before ending related restrictions.
This study employed a cross-sectional design, conducting an online survey among Chinese college students studying in Korea from April 8-15, 2022 (before Korea ended the limitations due to COVID-19). Data about 319 respondents were analyzed, including socio-demographics, information variables, knowledge, attitudes, practices (KAP), and C19P. Hierarchical regression analysis with different models was used to examine the relationship between information trust, KAP, and C19P.
Results showed that students performed well in knowledge and preventive practices, had diverse sources of getting information related to COVID-19, and highly depended on the internet and news. Students who perceived a higher severity of infection showed higher levels of COVID-19 phobia. The tendency to wear masks with family/friends, avoid crowded places, and not agree with Korean government mitigation policies reported higher levels of COVID-19 phobia.
More authority and proactive communication strategies, such as consultations or education programs, are needed for international students to alleviate their phobias and psychological stress.
Introduction 2-Amino-1-methyl-6-phenylimidazole 4,5-b pyridine (PhIP), a heterocyclic amine (HAA), is found in meat products heated at high temperatures. However, PhIP is a mutagenic and potential ...carcinogenic compound. Cassiae semen, a type of medicine and food homology plant, is abundant in China and has been less applied for inhibiting heterocyclic amines. Methods To investigate the inhibitory effect of cassiae semen extract on PhIP formation within a model system and elucidate the inhibitory mechanism, an ultrasonic-assisted method with 70% ethanol was used to obtain cassiae semen extract, which was added to a model system (0.6 mmol of phenylalanine: creatinine, 1:1). PhIP was analyzed by LC–MS to determine inhibitory effect. The byproducts of the system and the mechanism of PhIP inhibition were verified by adding the extract to a model mixture of phenylacetaldehyde, phenylacetaldehyde and creatinine. Results The results indicated that PhIP production decreased as the concentration of cassiae semen extract increased, and the highest inhibition rate was 91.9%. Byproduct (E), with a mass–charge ratio of m/z 199.9, was detected in the phenylalanine and creatinine model system but was not detected in the other systems. The cassiae semen extract may have reacted with phenylalanine to produce byproduct (E), which prevented the degradation of phenylalanine by the Strecker reaction to produce phenylacetaldehyde. Discussion Cassiae semen extract consumed phenylalanine, which is the precursor for PhIP, thus inhibiting the formation of phenylacetaldehyde and ultimately inhibiting PhIP formation. The main objective of this study was to elucidate the mechanism by which cassiae semen inhibit PhIP formation and establish a theoretical and scientific foundation for practical control measures.
Percutaneous thermal ablation is an important treatment for lung cancer and is widely used in hospitals. Puncture biopsy is generally required for pathological diagnosis before or after thermal ...ablation. Pathological diagnosis provides both evidence of benign and malignant lesions for ablation therapy and is of important significance for the next step in disease management. Furthermore, the sequence of ablation and biopsy affects the accuracy of pathological diagnosis, the complete ablation rate of thermal ablation, and incidence of surgery‐related complications. Ultimately, it may affect the patient's benefit from local treatment. This article reviews the research progress of traditional asynchronous biopsy followed by ablation, the emerging methods of synchronous biopsy followed by ablation, and synchronous ablation followed by biopsy in the last decade.
Key points
The sequence of ablation and biopsy affects the accuracy of pathological diagnosis, the complete ablation rate of thermal ablation, and the incidence of surgical‐related complications.
This article reviewed the recent 10 years' literature on the surgical sequence of biopsy and ablation for lung tumors, the advantages, disadvantages and indications of different orders were analyzed.
This article reviews the research progress of traditional asynchronous biopsy followed by ablation, the emerging methods of synchronous biopsy followed by ablation, and synchronous ablation followed by biopsy in the last decade.
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