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Background: The number of frail older people is increasing worldwide, and all countries will be confronted with their growing needs for healthcare and social support. The aim of this umbrella review was to summarize the evidence on the factors associated with frailty in older people, using a socioecological approach. Methods: PubMed (MEDLINE), Scopus, Web of Science, ScienceDirect, Hinari (research4life), and the Trip database were systematically searched up to April 2023. Systematic reviews of observational studies that explored factors associated with frailty in older adults aged 60 years and over were considered for inclusion. No language, geographical or setting restrictions were applied. However, we excluded systematic reviews that investigated frailty factors in the context of specific diseases. The Joanna Briggs Institute Critical Appraisal Checklist for Systematic Reviews and Research Syntheses and the ROBIS tool were used to assess the quality and risk of bias in the included studies. Results: Forty-four systematic reviews were included, covering 1,150 primary studies with approximately 2,687,911 participants overall. Several risk factors, protective factors and biomarkers were found to be associated with frailty, especially in community-dwelling older people, including 67 significant associations from meta-analyses. The certainty of the evidence was rated as moderate or reached moderate levels for seven factors relevant to older people. These factors include depression (OR 4.66, 95% CI 4.07 to 5.34), loneliness (OR 3.51, 95% CI 2.70 to 4.56), limitations in activities of daily living (OR 2.59, 95% CI 1.71 to 3.48), risk of malnutrition (OR 3.52, 95% CI 2.96 to 4.17), Dietary Inflammatory Index score (OR 1.24, 95% CI 1.16 to 1.33), maximal walking speed (Standardized Mean Difference (SMD) -0.97, 95% CI -1.25 to -0.68), and self-reported masticatory dysfunction (OR 1.83, 95% CI 1.55 to 2.18). Additionally, only greater adherence to a Mediterranean diet showed a high level of evidence (OR 0.44, 95% CI 0.31 to 0.64). Conclusions: This umbrella review will provide guidance for prevention strategies and clinical practice by promoting healthy lifestyles and addressing all modifiable risk factors associated with frailty. Future systematic reviews should consider heterogeneity and publication bias, as these were the main reasons for downgrading the level of evidence in our review. Registration: PROSPERO 2022, CRD42022328902. [ABSTRACT FROM AUTHOR]

In this paper, the influence of the Coefficient of Thermal Expansion (CTE) on the thermal stress analysis of laminated composite plates is explored. By introducing the undetermined integral terms in the displacement field, a new simple and efficient higher-order shear deformation theory is formulated for the thermo-mechanical behavior of thick laminated composite plates. This formulation aims to reduce the number of generated unknowns. Typically, a reduced order of the governing partial differential equations is expressed using the principle of virtual displacements. By using Navier's technique, closed-form solutions are derived for laminated composite plates under thermal and/or mechanical loading. Unfortunately, several traditional research investigations significantly depend on the rule of the mixture to determine reliable CTE for composites. This paper offers and examines a variety of analytical micromechanics-based models for estimating CTE in laminated composite materials, incorporating into consideration different considerations. The obtained results are compared to those given by other alternative plate theories, and the efficiency and accuracy of the present theory are demonstrated for the thermomechanical behavior of laminated composite plates. This study reviews and applies several micromechanics-based models, contrary to previous investigations. Laminated composite plates could delaminate or crack due to the matrix material's longitudinal CTE, affecting fiber volume fraction and stacking sequence. Micromechanics-based approaches are important when arbitrary thermo-mechanical characteristics can generate inaccuracies. Interestingly, micromechanics-based models can estimate effective CTE. Schapery, Chamberlain, and Chamis provide models with identical longitudinal CTE. For increasing fiber volume fractions, Chamberlain's model is more sensitive to increasing fiber volume fractions. Mechanical stress changes laminated plate behavior more than thermal loading. Although all presented micromechanical-based models have simplified representations, this research attempts to provide a standard for future investigations. The use of detailed micromechanical-based models stimulates further progress in understanding and utilizing complex composite plates. [ABSTRACT FROM AUTHOR]

Quasi-3D high-order shear deformation theories (HSDT) are often more effective for investigating advanced composite thick plates than two-dimensional (2D) theories. The present study examines the specific dimensionality effect of quasi-3D HSDT theories through-thickness stretching on the free vibration behavior of thin-thick rectangular plates. For this purpose, a 3D displacement field defined by only five unknowns is proposed. Besides, it contains a stretching component that contributes to the whole behavior of the plate. The results of the 2D model are compared to the results of the quasi-3D model. In addition, several factors, such as the aspect ratio, geometrical ratio, and material index, illustrate the influence of dimensionality. Young's modulus and densities should be graded in the direction of thickness. The motion equations are deduced based on Hamilton's principle. According to the boundary condition type, Navier's solution method is used for solving the obtained equations. The results show that the inclusion of the stretching component would increase the dynamic response of the thick advanced composite plates. Moreover, the influence of dimensionality is less significant for pure ceramic plates. [ABSTRACT FROM AUTHOR]

Background: Breast cancer patients in sub-Saharan Africa experience long time intervals between their first presentation to a health care facility and the start of cancer treatment. The role of the health system in the increasing treatment time intervals has not been widely investigated. This review aimed to identify existing information on health system factors that influence diagnostic and treatment intervals in women with breast cancer in sub-Saharan Africa to contribute to the reorientation of health policies in the region.Methods: PubMed, ScienceDirect, African Journals Online, Mendeley, ResearchGate and Google Scholar were searched to identify relevant studies published between 2010 and July 2020. We performed a qualitative synthesis in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Related health system factors were extracted and classified according to the World Health Organization's six health system building blocks. The quality of qualitative and quantitative studies was assessed by using the Critical Appraisal Skills Program Quality-Assessment Tool and the National Institute of Health Quality Assessment Tool, respectively. In addition, we used the Confidence in the Evidence from Reviews of Qualitative Research tool to assess the evidence for each qualitative finding.Results: From 14,184 identified studies, this systematic review included 28 articles. We identified a total of 36 barriers and 8 facilitators that may influence diagnostic and treatment intervals in women with breast cancer. The principal health system factors identified were mainly related to human resources and service delivery, particularly difficulty accessing health care, diagnostic errors, poor management, and treatment cost.Conclusion: The present review shows that diagnostic and treatment intervals among women with breast cancer in sub-Saharan Africa are influenced by many related health system factors. Policy makers in sub-Saharan Africa need to tackle the financial accessibility to breast cancer treatment by adequate universal health coverage policies and reinforce the clinical competencies for health workers to ensure timely diagnosis and appropriate care for women with breast cancer in this region. [ABSTRACT FROM AUTHOR]

Advanced mechanical and structural applications require accurate assessment and better knowledge of the damage state during elaboration and service. The development of life prediction methodologies for Glass Fiber Reinforced Polymers (GFRPs) has increased with the use of composites in different industries. It is important to develop through thickness degradation analyses due to ageing in order to predict its effect on the lifetime of composite structures. This study aims to model the moisture absorption, the concentration of the absorbed fluid and the reduction of mechanical properties in the through the thickness direction of a GFRPs structure. The water absorption behavior of woven glass fiber reinforced cyanate ester composites used in the plenum of the air conditioning pack of aircraft environmental control system has been modeled. The combined models describe the diffusion procedure primarily at material level and continuously at structure level. The amount of the absorbed moisture can be crucial for the mechanical behavior of the structure. Therefore, there is a need for a better understanding of the evolution of mechanical properties during ageing. The procedure utilizes the results of the diffusion model to calculate the moduli degradation during the water uptake process. Predictive models have been proposed by considering different sections throughout the thickness and provide a solid background for modeling the long term behavior of a structure exposed at different temperature and different time period. This work performed the numerical studies on the effect of moisture, temperature and presents some useful instructions for the evaluation of such composite structures. [ABSTRACT FROM AUTHOR]

The objective of this work lies in the three-dimensional study of the thermo mechanical behavior of a blade of a centrifugal compressor. Numerical modeling is performed on the computational code "ABAQUS" based on the finite element method. The aim is to study the impact of the change of types of blades, which are defined as a function of wheel output angle β2, on the stress fields and displacements coupled with the variation of the temperature. This coupling defines in a realistic way the thermo mechanical behavior of the blade where one can note the important concentrations of stresses and displacements in the different zones of its complex form as well as the effects at the edges. It will then be possible to prevent damage and cracks in the blades of the centrifugal compressor leading to its failure which can be caused by the thermal or mechanical fatigue of the material with which the wheel is manufactured. [ABSTRACT FROM AUTHOR]

While students in the health sciences occupy pivotal roles in the Moroccan COVID-19 response and vaccination campaigns, factors associated with COVID-19 vaccine acceptability among students have not been reported. This study aimed to determine the willingness and identify predictive attitudes and beliefs of COVID-19 vaccine acceptance among health science students in Morocco. A cross-sectional, self-administered online questionnaire was conducted among students of the Mohammed VI University of Health Sciences in Casablanca, Morocco in January 2021. In total, 1272 students participated. Univariate and multivariate logistic regression models were used to calculate odds ratios and 95% confidence intervals. Overall, 26.9% of participants reported being willing to receive the COVID-19 vaccine. Between genders, male students were more likely to accept the vaccine. Regarding individual attitudes and beliefs about COVID-19 infection, students with greater confidence in COVID-19 information, and higher perceived likelihood and perceived severity of infection were more likely to be willing to get the vaccine. Concerning a COVID-19 vaccine, students who reported lower levels of perceived harm and higher levels of perceived vaccine effectiveness were more willing to get vaccinated. Our findings help guide future efforts to tailor communication and identify strategies to increase COVID-19 vaccine uptake among students. [ABSTRACT FROM AUTHOR]

Matrix polymer composite materials are increasingly required especially for high-performance applications. Sadly, these materials are subjected to degradation in a given environment. Indeed, the aromatic structure of the matrix makes it not only sensitive to the effects of certain solvents, but also susceptible to the reorganization of chains over time. This last phenomenon is known as ageing and leads to the loss of initial physical and mechanical properties of the matrix. Degradation problem due to the exposure to the environment is one of the most critical affecting phenomena in the use of composite materials in various structures. The objective of this work is to present a study of temperature and humidity effects on plates of polymer matrix materials. The hygrothermal effects are analysed in a study of water concentration evolution through the plate thickness (Fick's model). The second part of this work deals with the determination of water concentrations in composite material plates using a probabilistic method. It also aims to demonstrate the importance of probabilistic methods in the field of composite materials and to study uncertainty regarding the unpredictable variables. [ABSTRACT FROM AUTHOR]