Predicting the recurrence of spontaneous intracerebral hemorrhage using a machine learning model

BackgroundRecurrence can worsen conditions and increase mortality in ICH patients. Predicting the recurrence risk and preventing or treating these patients is a rational strategy to improve outcomes potentially. A machine learning model with improved performance is necessary to predict recurrence.MethodsWe collected data from ICH patients in two hospitals for our retrospective training cohort and prospective testing cohort. The outcome was the recurrence within one year. We constructed logistic regression, support vector machine (SVM), decision trees, Voting Classifier, random forest, and XGBoost models for prediction.ResultsThe model included age, NIHSS score at discharge, hematoma volume at admission and discharge, PLT, AST, and CRP levels at admission, use of hypotensive drugs and history of stroke. In internal validation, logistic regression demonstrated an AUC of 0.89 and precision of 0.81, SVM showed an AUC of 0.93 and precision of 0.90, the random forest achieved an AUC of 0.95 and precision of 0.93, and XGBoost scored an AUC of 0.95 and precision of 0.92. In external validation, logistic regression achieved an AUC of 0.81 and precision of 0.79, SVM obtained an AUC of 0.87 and precision of 0.76, the random forest reached an AUC of 0.92 and precision of 0.86, and XGBoost recorded an AUC of 0.93 and precision of 0.91.ConclusionThe machine learning models performed better in predicting ICH recurrence than traditional statistical models. The XGBoost model demonstrated the best comprehensive performance for predicting ICH recurrence in the external testing cohort

Association of Aortic Stiffness and Cognitive Decline: A Systematic Review and Meta-Analysis

Background: Increased aortic stiffness has been found to be associated with cognitive function decline, but the evidence is still under debate. It is of great significance to elucidate the evidence in this debate to help make primary prevention decisions to slow cognitive decline in our routine clinical practice.Methods: Electronic databases of PubMed, EMBASE, and Cochrane Library were systematically searched to identify peer-reviewed articles published in English from January 1, 1986, to March 16, 2020, that reported the association between aortic stiffness and cognitive function. Studies that reported the association between aortic pulse wave velocity (PWV) and cognitive function, cognitive impairment, and dementia were included in the analysis.Results: Thirty-nine studies were included in the qualitative analysis, and 29 studies were included in the quantitative analysis. The aortic PWV was inversely associated with memory and processing speed in the cross-sectional analysis. In the longitudinal analysis, the high category of aortic PWV was 44% increased risk of cognitive impairment (OR 1.44; 95% CI 1.24–1.85) compared with low PWV, and the risk of cognitive impairment increased 3.9% (OR 1.039; 95% CI 1.005–1.073) per 1 m/s increase in aortic PWV. Besides, meta-regression analysis showed that age significantly increased the association between high aortic PWV and cognitive impairment risk.Conclusion: Aortic stiffness measured by aortic PWV was inversely associated with memory and processing speed and could be an independent predictor for cognitive impairment, especially for older individuals

Do family-planning workers in China support provision of sexual and reproductive health services to unmarried young people?

OBJECTIVE: To ascertain the perspectives of family-planning service providers in eight sites in China on the provision of sexual and reproductive health services to unmarried young people. METHODS: Data were drawn from a survey of 1927 family-planning workers and 16 focus group discussions conducted in eight sites in China in 1998-99. FINDINGS: Family-planning workers recognized the need to protect the sexual health of unmarried young people and were unambiguous about the need for government agencies to provide information and education on sexual and reproductive health to unmarried young people; however, perceptions about the appropriate age for and content of such education remained conservative. While about 70% of family-planning workers were willing to provide contraceptives to unmarried young people, and about 60% approved government provision of contraceptive services to unmarried young people, only one quarter agreed that the services could be extended to senior high schools. CONCLUSION: Family-planning workers in China are ambivalent about the provision of sexual and reproductive health services to unmarried young people, which potentially poses a significant obstacle to the adoption of safe sex behaviours by young people, as well as to the provision of sexual and reproductive health information and services to young unmarried people in China. Training programmes for family-planning workers are urgently needed to address this issue

Do family-planning workers in China support provision of sexual and reproductive health services to unmarried young people?

OBJECTIVE: To ascertain the perspectives of family-planning service providers in eight sites in China on the provision of sexual and reproductive health services to unmarried young people. METHODS: Data were drawn from a survey of 1927 family-planning workers and 16 focus group discussions conducted in eight sites in China in 1998-99. FINDINGS: Family-planning workers recognized the need to protect the sexual health of unmarried young people and were unambiguous about the need for government agencies to provide information and education on sexual and reproductive health to unmarried young people; however, perceptions about the appropriate age for and content of such education remained conservative. While about 70% of family-planning workers were willing to provide contraceptives to unmarried young people, and about 60% approved government provision of contraceptive services to unmarried young people, only one quarter agreed that the services could be extended to senior high schools. CONCLUSION: Family-planning workers in China are ambivalent about the provision of sexual and reproductive health services to unmarried young people, which potentially poses a significant obstacle to the adoption of safe sex behaviours by young people, as well as to the provision of sexual and reproductive health information and services to young unmarried people in China. Training programmes for family-planning workers are urgently needed to address this issue

A study on the micromechanical behavior of Ti-55531 titanium alloy with lamellar microstructure by in-situ neutron diffraction

High strength titanium alloys are promising materials for heavy component parts in the aviation industry. The limited combination of strength and ductility requires an understanding of deformation and stress partitioning between constituent phases. The micromechanical behaviors of Ti-55531 titanium alloy with lamellar microstructure are investigated by in-situ neutron diffraction. The phase strain and lattice strain evolution of α and β phase at loading direction and transverse direction are determined. The results show that the micromechanical behaviors of oriented grains of α and β phase are obviously different. Furthermore, the stress partitioning between α and β phase during the deformation is clearly illustrated. It is found that the β matrix is subjected to higher stress than α precipitates. In addition, the intergranular and interphase microstress is quantitatively characterized. It is found that the intergranular microstress in the β phase grains is predominant among these microstresses. Combining the in-situ neutron diffraction with microstructure characterization, the present work provides a guide for further microstructure optimization

A study on the micromechanical behavior of Ti-55531 titanium alloy with lamellar microstructure by in-situ neutron diffraction

High strength titanium alloys are promising materials for heavy component parts in the aviation industry. The limited combination of strength and ductility requires an understanding of deformation and stress partitioning between constituent phases. The micromechanical behaviors of Ti-55531 titanium alloy with lamellar microstructure are investigated by in-situ neutron diffraction. The phase strain and lattice strain evolution of α and β phase at loading direction and transverse direction are determined. The results show that the micromechanical behaviors of oriented grains of α and β phase are obviously different. Furthermore, the stress partitioning between α and β phase during the deformation is clearly illustrated. It is found that the β matrix is subjected to higher stress than α precipitates. In addition, the intergranular and interphase microstress is quantitatively characterized. It is found that the intergranular microstress in the β phase grains is predominant among these microstresses. Combining the in-situ neutron diffraction with microstructure characterization, the present work provides a guide for further microstructure optimization

Unveiling the dynamic softening mechanism via micromechanical behavior for a near-β titanium alloy deformed at a high strain rate

For near-β high-strength titanium alloys, rheological softening is the key step during thermal deformation to determine the microstructure and mechanical properties. Nevertheless, the intrinsic softening mechanism during the rheological stage is still an open question due to the special complexity of the process. In this study, the deformation process of near-β titanium alloy TC18 (Ti–5Al–5Mo–5V–1Cr–1Fe, wt.%) in a dual-phase region at a high strain rate was investigated. The micromechanical behavior of TC18 alloy during thermal deformation at 785 °C and 0.1/s was revealed by using in-situ high-energy X-ray diffraction (HEXRD). The stress partitioning and microstructure evolution mechanism for this alloy were discussed in detail. It has been confirmed that the main softening mechanisms of TC18 alloy during thermal deformation are dynamic recovery (DR) and continuous dynamic recrystallization (cDRX). The stress partitioning between constituent phases featured by higher stress in the α phase than in the β phase induces an inhomogeneous strain field near α phase lamellae to promote the dislocation pile-up in subgrains. The cDRX process of β grains is composed of dislocation slipping, DR and subgrains formation, and transformation of recrystallized grains with high-angle grain boundaries (HAGB). Schmid factor and micro stress have a remarkable effect on dynamic recrystallization (DRX) behavior. The soft β//LD oriented grains are more likely to undergo cDRX than the hard β//LD oriented grains. This work may have implications for understanding the deformation mechanism and provide a fundamental basis for selecting appropriate processing technology for near-β titanium alloys

Young internal migrants’ major health issues and health seeking barriers in Shanghai, China: a qualitative study

Abstract Background China is experiencing a sizeable rural-urban flow, which may influence the health of internal migrant youth deeply. Disadvantages in the city are highly likely to contribute to health issues among the young internal migrant population. The current qualitative study is to explore how internal migrant young people view the health issues they face, and the services and opportunities they could seek in their host community. Methods Data were collected from 90 internal migrant youth aged between 15 and 19 years old and 20 adult service providers who worked with them in a community of Shanghai, where the population of internal migrants was relatively large. Four types of qualitative research methods were used, including key informant interviews with adults, in-depth interviews with adolescents, a photovoice activity with adolescents and community mapping & focus group discussions with adolescents. Guided by the ecological systems framework and the acculturation theory, thematic analysis was conducted using ATLAS.Ti 7.0 software. Results While younger migrants had a limited understanding of health, elder migrant youths were more sensitive to societal and political factors related to their health. Mental health and health risk behaviors such as smoking, violence and premarital unsafe sex were thought as major health issues. Internal migrant youths rarely seek health information and services initiatively from formal sources. They believed their health concerns weren’t as pressing as the pressure coming from the high cost of living, the experience of being unfairly treated and the lack of opportunities. Participants also cited lack of family and social support, lack of awareness and supportive policies to get access to community and public services as impacting health factors. Conclusions The study’s findings provide the insight to the social contexts which influence the health experience, health seeking behaviors, and city adaptation of young internal migrants in their host community. This research stresses the importance of understanding social networks and structural barriers faced by migrant youth in vulnerable environments. A multidimensional social support is essential for internal migrant youth facing present and potential health risks

The Portevin–Le Chatelier Effect of Cu–2.0Be Alloy during Hot Compression

The Portevin–Le Chatelier effect of Cu–2.0Be alloy was investigated using hot isothermal compression at varying strain rates (0.01–10 s−1) and temperature (903–1063 K). An Arrhenius-type constitutive equation was developed, and the average activation was determined. Both strain-rate-sensitive and temperature-sensitive serrations were identified. The stress–strain curve exhibited three types of serrations: type A at high strain rates, type B (mixed A + B) at medium strain rates, and type C at low strain rates. The serration mechanism is mainly affected by the interaction between the velocity of solute atom diffusion and movable dislocations. As the strain rate increases, the dislocations outpace the diffusion speed of the solute atoms, limiting their ability to effectively pin the dislocations, resulting in lower dislocation density and serration amplitude. Moreover, the dynamic phase transformation triggers the formation of nanoscale dispersive β phases, which impede dislocation and cause a rapid increase in the effective stress required for unpinning, leading to the formation of mixed A + B serrations at 1 s−1