Contrast U-Net driven by sufficient texture extraction for carotid plaque detection.

Ischemic heart disease or stroke caused by the rupture or dislodgement of a carotid plaque poses a huge risk to human health. To obtain accurate information on the carotid plaque characteristics of patients and to assist clinicians in the determination and identification of atherosclerotic areas, which is one significant foundation work. Existing work in this field has not deliberately extracted texture information of carotid from the ultrasound images. However, texture information is a very important part of carotid ultrasound images. To make full use of the texture information in carotid ultrasound images, a novel network based on U-Net called Contrast U-Net is designed in this paper. First, the proposed network mainly relies on a contrast block to extract accurate texture information. Moreover, to make the network better learn the texture information of each channel, the squeeze-and-excitation block is introduced to assist in the jump connection from encoding to decoding. Experimental results from intravascular ultrasound image datasets show that the proposed network can achieve superior performance compared with other popular models in carotid plaque detection.

Assessment of fetal intraventricular diastolic fluid dynamics using ultrasound vector flow mapping.

OBJECTIVE: The purpose of this study was to investigate the feasibility of visualizing and quantifying the normal pattern of vortex formation in the left ventricle (LV) and right ventricle (RV) of the fetal heart during diastole using vector flow mapping (VFM). METHODS: A total of 36 healthy fetuses in the second trimester (mean gestational age: 23 weeks, 2 days; range: 22-24 weeks) were enrolled in the study. Color Doppler signals were recorded in the four-chamber view to observe the phase of the diastolic vortices in the LV and RV. The vortex area and circulation were measured, and parameters such as intraventricular pressure difference (IVPD), intraventricular pressure gradient (IVPG), and average energy loss (EL_AVG) were evaluated at different diastolic phases, including isovolumic relaxation (D1), early diastole (D2), and late diastole (D3). RESULTS: Healthy second-trimester fetal vortex formations were observed in both the LV and RV at the end of diastole, with the vortices rotating in a clockwise direction towards the outflow tract. There were no significant differences in vortex area and circulation between the two ventricles (p > 0.05). However, significant differences were found in IVPD, IVPG, and EL_AVG among the diastolic phases (D1, D2, and D3) (p < 0.05). Trends in IVPD, IVPG, and EL_AVG during diastole (D1-D2-D3) revealed increasing IVPD and EL_AVG values, as well as decreasing IVPG values. Furthermore, during D3, the RV exhibited significantly higher IVPD, IVPG, and EL_AVG compared to the LV (p > 0.05). CONCLUSION: VFM is a valuable technique for analyzing the formation of vortices in the left and right ventricles during fetal diastole. The application of VFM technology has the potential to enhance the assessment of fetal cardiac parameters.

Automatic segmentation of ultrasound images of carotid atherosclerotic plaque based on Dense-UNet.

BACKGROUND: Carotid atherosclerosis plaque rupture is an important cause of myocardial infarction and stroke. The effective segmentation of ultrasound images of carotid atherosclerotic plaques aids clinicians to accurately assess plaque stability. At present, this procedure relies mainly on the experience of the medical practitioner to manually segment the ultrasound image of the carotid atherosclerotic plaque. This method is also time-consuming. OBJECTIVE: This study intends to establish an automatic intelligent segmentation method of ultrasound images of carotid plaque. METHODS: The present study combined the U-Net and DenseNet networks, to automatically segment the ultrasound images of carotid atherosclerotic plaques. The same test set was selected and segmented using the traditional U-Net network and the ResUNet network. The prediction results of the three network models were compared using Dice (Dice similarity coefficient), and VOE (volumetric overlap error) coefficients. RESULTS: Compared with the existing U-Net network and ResUNet network, the Dense-UNet network exhibited an optimal effect on the automated segmentation of the ultrasound images. CONCLUSION: The Dense-UNet network could realize the automatic segmentation of atherosclerotic plaque ultrasound images, and it could assist medical practitioners in plaque evaluation.

Becoming Urban Citizens: A Three-Phase Perspective on the Social Integration of Rural-Urban Migrants in China.

This article attempts to provide an integrated conceptual framework for understanding how rural-urban migrants in China integrate into urban society. We propose a three-phase conceptual framework in which the social integration of rural-urban migrants is categorized into circular migration, urban settlement, and urban integration. We argue that the three phases differ with respect to the aims of migration, the identity of migrants, the key dimensions of social integration, the role of government, and the hukou policy. While the transition from circular migration to urban settlement is an outcome of economic development and change in demographic structure, as reflected by the economic conditions of rural-urban migrants, welfare expansion also plays a critical role during this process. We further hypothesize that the transition from urban settlement to urban integration will be a result of the social interaction between rural-urban migrants and local urbanites, within which social capital and cultural factors are vital. Since most rural-urban migrants are currently at the phase of urban settlement, we suggest that the Chinese government should enlarge welfare provisions to support their settlement in cities. This study contributes to improving the understanding of how to facilitate social integration of internal migrants in developing countries.

Bullying Victimization, Coping Strategies, and Depression of Children of China.

It is common knowledge that bullying victimization and coping strategies significantly affect the psychological well-being of children. However, which coping strategies are more effective at a particular level of bullying victimization is underexplored. Using survey data from 1,634 children from 10 schools in Wuhan, China, this study aims to investigate the abovementioned research gap. The results of factor analysis suggest that coping strategies of children in China can be divided into three types: help-seeking, avoidance, and self-defense. The results of multilevel modeling suggest that children adopting different coping strategies have distinct levels of depression. Help seekers show a significantly lower level of depression than self-defenders and avoiders. However, with increased bullying victimization, the effectiveness of the help-seeking strategy gradually decreases to offset the negative effect of bullying victimization on psychological well-being. Instead, those who adopt the self-defense strategy display a lower level of depression. The findings of this study suggest that there is no single coping strategy that is best for children, and the more effective strategy largely relies on the level of bullying victimization. The findings also imply that without external support, it is almost impossible for children to completely overcome the negative consequences of bullying on their own.

Acculturation, urban identity, and psychological well-being of rural-urban migrants in China.

Acculturation and identity are two significant determinants of the psychological well-being of migrants, but how they interactively affect psychological well-being is still underexplored. This study proposes an interactional perspective that links acculturation and urban identity to the psychological well-being of rural-urban migrants in China. Using data from the 2014 National Migrant Population Dynamic Monitoring Survey, the results of multilevel modeling indicate that both acculturation and urban identity significantly affect the psychological well-being of rural-urban migrants. Migrants who adopt the integration and assimilation strategy show better psychological well-being than those who adopt the separation and marginalization strategy. Rural-urban migrants who have a stronger sense of urban identity show better psychological well-being than those with a weaker sense of urban identity. Meanwhile, urban identity and acculturation also interactively affect the psychological well-being of rural-urban migrants. In particular, urban identity alleviates the negative pressure generated in the process of acculturation for those who adopt the acculturation strategy of separation. In addition, the effect of acculturation and urban identity on the psychological well-being of rural-urban migrants varies by migration distance. The research contributes to the literature by demonstrating that cultural identity and place identity interactively affect the psychological well-being of internal migrants.

In vitro dynamic bladder models for studying urinary tract infections: a narrative review.

Experimental models of the bladder are key to studying the pathogenic mechanism of catheter-related bacterial biofilm infection. Although numerous studies have reported multiple models, these model designs were heterogeneous. This study aimed to review the status quo and explore the problems associated with in vitro dynamic bladder models for studying urinary tract infections (UTIs). The PubMed and SinoMed databases were searched from their inception to February 2020. Studies regarding in vitro bladder models related to UTIs were reviewed based on a bibliometric evaluation of their basic characteristics and model analysis. A total of 74 papers and 44 bladder models were included in this study. The results were as follows: (I) urine transmission devices: 10 studies applied the gravity effect of culture media, while the others used peristaltic pumps, and 11 of them combined stirring or rotating forces. The flow rates in all studies ranged from 15 µL/min to 50 mL/min. (II) Bladder model: two studies reported on simulating the bladder using plastic bags, while the others reported on glass cylinders or fermenters with a capacity of 200 to 700 mL. E. coli and P. mirabilis were the main bacterial strains. (III) Infection carrier: six studies reported planktonic bacteria as their infection carrier, while 45 studies reported silica gel, rubber, polyurethane, silicone, polytetrafluoroethylene, or perfusion bag. (IV) Infection medium: 25 studies reported the culture medium. Thirty-two studies reported artificial urine, while 17 studies reported human urine. (V) Research analysis: 45 studies investigated the bacterial biofilm formation in the bladder model. Thirty-six studies compared the effects of various drug coatings, diverse material surfaces, or different materials. Only five studies compared distinct bladder models. The included studies' main defects were the single simulation of bladder urodynamics, divers parameter settings, and non-standard experimental modeling. Our analysis showed for the first time that in vitro dynamic bladder models could provide new ideas for exploring the mechanism and prevention of bacterial biofilm infection in urinary implanted biomaterials. Due to the limitations of the included studies, more high-quality studies are needed to verify the conclusions above further.

Psychological Distress in Urbanizing China: How Does Local Government Effectiveness Matter?

Despite growing literature identifying key individual, family, community, and environmental factors as causes for mental disorders during the process of urbanization, the role played by local government has not been taken into account. In this article, we investigate how the effectiveness of local government affects residents' levels of psychological distress in areas of China undergoing urbanization. We measure the effectiveness of local governments according to their success in promoting access to the social security system through the distribution of social security cards among citizens. We hypothesize that higher local government effectiveness will reduce residents' psychological distress by alleviating worries about medical expenses and elder care. Drawing on data from the 2018 Urbanization and Quality of Life Survey (N = 3229) conducted in 40 localities undergoing rural-urban transition, we estimate three-level mixed-effects regression models to test the research hypotheses, allowing random effects at the township/county and neighborhood levels while controlling for a series of individual attributes. The results demonstrate that local government effectiveness is negatively associated with residents' psychological distress: effective local governments alleviate worries about medical expenses and elder care, and thereby reduce psychological distress. The findings indicate that, to reduce residents' worries and psychological distress during the process of rural-urban transition, it is essential to improve local government effectiveness, particularly in promoting residents' access to the social security system. Beyond demonstrating how local government effectiveness matters for residents' psychological distress, our research also illustrates how to properly model locational parameters in analyses of individual well-being.

Risk Perception and Depression in Public Health Crises: Evidence from the COVID-19 Crisis in China.

Background: Scant attention has been paid to how risk perceptions of public health crises may affect people's mental health. Aims: The aims of this study are to (1) construct a conceptual framework for risk perception and depression of people in public health crises, (2) examine how the mental health of people in the crisis of Coronavirus Disease 2019 (COVID-19) is affected by risk perception and its associated factors, including distance perception of the crisis and support of prevention and control policies, and (3) propose policy recommendations on how to deal with psychological problems in the current COVID-19 crisis. Methods: Online questionnaire survey was implemented. A total of 6373 people visited the questionnaire online, 1115 people completed the questionnaire, and the number of valid questionnaires was 1081. Structural equation modeling was employed for data analysis. Results: Risk perception and its associated factors significantly affect the mental health of people in public health crises. Specifically, (1) distance perception of public health crises is negatively associated with depression among people, (2) affective risk perception is positively associated with depression of people in public health crises, (3) cognitive risk perception is negatively associated with depression of people in public health crises, and (4) support of prevention and control policies is negatively associated with depression of people in public health crises. Conclusion: The findings of this study suggest that risk perception plays an important role in affecting the mental health of people in a public health crisis. Therefore, health policies aiming to improve the psychological wellbeing of the people in a public health crisis should take risk perception into consideration.

An ecological investigation of resilience among rural-urban migrant adolescents of low socioeconomic status families in China.

The present study aims to explore the mechanism of resilience among rural-urban migrant adolescents of low socioeconomic status (SES) families in China with the ecological system perspective. Selecting 946 rural-urban migrant adolescents from the China Education Panel Survey, we used latent class analyses to distinguish different levels of resilience among migrant adolescents from low-SES families, and logistic regressions to identify factors associated with resilience and to examine the cumulative risk and protection models. The findings show that parental expectation, teacher support and organised neighbourhood are salient resilience-promoting factors; and resilience happens only if protective factors accumulate enough at multiple systems to compensate the negative effect of cumulative community risk. The study describes the importance of a protective environment in the domains of family, school and neighbourhood on the resilience of this group, and suggest intervention programmes should extend the paradigm from child-centred approach to environment-focused approach to potentiate the positive development of this population.

The effect of health on urban-settlement intention of rural-urban migrants in China.

Previous studies have not paid enough attention to the effect of health on urban-settlement intention of rural-urban migrants in China. Using survey data from the Rural Urban Migration in China project, this article examines how self-rated physical and mental health influence rural-urban migrants' intention to settle down in cities. First, the results show that both self-rated physical and mental health are significant factors influencing the migrants' intention to permanently move to cities. Second, the effect of physical health on rural-urban migrants' intentions to permanently reside in cities can be moderated by their length of urban residence. Third, the impact of health on rural-urban migrants' urban-settlement intention shows no generational differences. According to the research findings, this paper discusses how urban-settlement intention of rural-urban migrants based on health selection might impair urbanization, exacerbate health disparity between the rural and urban areas, and aggravate the burden on healthcare system in rural areas of China in the long run.

The Migration, Mental Stress, and Tobacco use of Internal Migrants in China: The Moderating Effect of the Social Context of the Host Society.

BACKGROUND: Previous studies on the relationship between mental stress and the tobacco use of internal migrants have not fully considered the social context of the host society. OBJECTIVES: This study aims to examine how mental stress influences cigarette smoking in internal migrants in China by considering the social context of the host society. METHODS: We used the RUMiC data that were collected in 15 cities distributed throughout 9 provinces of China. A total of 8,446 and 5,426 migrant workers were interviewed in 2008 and 2009, respectively. We selected individuals based on the criteria of age, salary, and hukou status. A total of 8,880 observations are valid for this study. This research used the logistic regression method to test the association between mental stress and the tobacco use of internal migrants. RESULTS: The results show that mental stress is not necessarily associated with the tobacco use of internal migrants. However, the effects of mental stress on tobacco use are moderated by the social context of the host society. CONCLUSIONS: This article calls for more attention to be paid to the moderate effect of social context in the host society on the association between mental stress and cigarette smoking of internal migrants. Moreover, this article underscores the importance of factors related to local societies in making and enacting tobacco control policies for migrants in developing countries.

[Present status and trend of heart fluid mechanics research based on medical image analysis].

With introduction of current main methods for heart fluid mechanics researches, we studied the characteristics and weakness for three primary analysis methods based on magnetic resonance imaging, color Doppler ultrasound and grayscale ultrasound image, respectively. It is pointed out that particle image velocity (PIV), speckle tracking and block match have the same nature, and three algorithms all adopt block correlation. The further analysis shows that, with the development of information technology and sensor, the research for cardiac function and fluid mechanics will focus on energy transfer process of heart fluid, characteristics of Chamber wall related to blood fluid and Fluid-structure interaction in the future heart fluid mechanics fields.

Intuitive visualization and quantification of intraventricular convection in acute ischemic left ventricular failure during early diastole using color Doppler-based echocardiographic vector flow mapping.

The aim of this study was to make an intuitive visualization of intraventricular convection (IC) and quantification of intraventricular convection velocity (ICV) in acute ischemic left ventricular (LV) failure of open-chest canines during early diastole contrast to the baseline conditions using color Doppler-based echocardiographic vector flow mapping (VFM). The animal care committee approved this prospective study. In 6 anesthetized open-chest beagle models, the emergence time and the emergence sites of IC in the LV cavity during early diastole were visualized at the standard apical 3-chamber (AP3c) views with the VFM at baseline conditions and after coronary artery ligation. The global ICV and the ICV at the basal, middle and apical levels of LV at the AP3c views at T1, T2, T3, T4, and T5 between both states were compared respectively (T1: the beginning of LV rapid filling period; T2: the middle of LV rapid filling period; T3: the peak of LV rapid filling period; T4: the middle of period of reduced filling; T5: the end of early diastole.). Acute ischemic LV failure with a marked increase in LV end diastolic volume and LV minimal diastolic pressure was induced by coronary artery ligation. The IC appeared only during the period of reduced filling at baseline conditions, and limited to the basal level of LV cavity. But the IC appeared throughout all the early diastole, and was seen almost occupying whole LV cavity during ischemia. The peak of the global ICV for both states appeared at T4. The global ICV at the AP3c views in acute ischemic failure LV cavity increased than those of baseline conditions at the T1 (6.593 ± 0.834 cm(2)/s vs. 0.000 ± 0.000 cm(2)/s, P < 0.001), T2 (9.457 ± 0.852 cm(2)/s vs. 0.000 ± 0.000 cm(2)/s, P < 0.001), T3 (14.765 ± 1.791 cm(2)/s vs. 2.030 ± 0.502 cm(2)/s, P < 0.001), T4 (25.392 ± 4.640 cm(2)/s vs. 6.688 ± 1.343 cm(2)/s, P < 0.001), and T5 (15.890 ± 3.159 cm(2)/s vs. 2.518 ± 0.869 cm(2)/s, P < 0.001). And the ICV at the basal, middle and apical levels at AP3c views in acute ischemic failure LV cavity also increased than those of baseline conditions at the same phase of early diastole (P < 0.01), except for the ICV at the LV basal level at T1. VFM is a powerful tool for visualization IC and quantification of ICV on profiles of LV flow fields, which can give intriguing insights into the subtle, flow-associated LV fluid dynamics of normal and abnormal cardiac function. It will be of great practical importance to elucidate the accurate physiological and the pathophysiological significance of the IC in further studies, so as to determine whether the cardiac function can be precisely evaluated with IC related index, and to incorporate VFM into clinical routine practice in the future.