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In the present study, the effects of human physiological activity levels on the fatigue life of a porous magnesium scaffold have been investigated. First, the dynamic immersion and biomechanical testing are carried out on a porous magnesium scaffold to simulate the physiological conditions. Then, a numerical data analysis and computer simulations predict the implant failure values. A 3D CAD bone scaffold model was used to predict the implant fatigue, based on the micro-tomographic images. This study uses a simulation of solid mechanics and fatigue, based on daily physiological activities, which include walking, running, and climbing stairs, with strains reaching 1000–3500 µm/mm. The porous magnesium scaffold with a porosity of 41% was put through immersion tests for 24, 48, and 72 h in a typical simulated body fluid. Longer immersion times resulted in increased fatigue, with cycles of failure (Nf) observed to decrease from 4.508 × 1022 to 2.286 × 1011 (1.9 × 1011 fold decrease) after 72 hours of immersion with a loading rate of 1000 µm/mm. Activities played an essential role in the rate of implant fatigue, such as demonstrated by the 1.1 × 105 fold increase in the Nf of walking versus stair climbing at 7.603 × 1011 versus 6.858 × 105, respectively. The dynamic immersion tests could establish data on activity levels when an implant fails over time. This information could provide a basis for more robust future implant designs.

The selection of biomaterials for bearing in total hip arthroplasty is very important to avoid various risks of primary postoperative failure for patients. The current investigation attempts to analyze the Tresca stress of metal-on-metal bearings with three different materials, namely, cobalt chromium molybdenum (CoCrMo), stainless steel 316L (SS 316L), and titanium alloy (Ti6Al4V). We used computational simulations using a 2D axisymmetric finite element model to predict Tresca stresses under physiological conditions of the human hip joint during normal walking. The simulation results show that Ti6Al4V-on-Ti6Al4V has the best performance to reduce Tresca stress by 45.76% and 39.15%, respectively, compared to CoCrMo-on-CoCrMo and SS 316L-on-SS 316L.

In designing porous scaffolds, permeability is essential to consider as a function of cell migration and bone tissue regeneration. Good permeability has been achieved by mimicking the complexity of natural cancellous bone. In this study, a porous scaffold was developed according to the morphological indices of cancellous bone (porosity, specific surface area, thickness, and tortuosity). The computational fluid dynamics method analyzes the fluid flow through the scaffold. The permeability values of natural cancellous bone and three types of scaffolds (cubic, octahedron pillar, and Schoen’s gyroid) were compared. The results showed that the permeability of the Negative Schwarz Primitive (NSP) scaffold model was similar to that of natural cancellous bone, which was in the range of 2.0 × 10−11 m2 to 4.0 × 10−10 m2. In addition, it was observed that the tortuosity parameter significantly affected the scaffold’s permeability and shear stress values. The tortuosity value of the NSP scaffold was in the range of 1.5–2.8. Therefore, tortuosity can be manipulated by changing the curvature of the surface scaffold radius to obtain a superior bone tissue engineering construction supporting cell migration and tissue regeneration. This parameter should be considered when making new scaffolds, such as our NSP. Such efforts will produce a scaffold architecturally and functionally close to the natural cancellous bone, as demonstrated in this study.

Abstract This study optimizes biocomposite filaments composed of polylactic acid (PLA), magnesium (Mg), and polyethylene glycol (PEG) for bone scaffold applications via 3D printing. Using Response Surface Methodology, extrusion parameters including temperature, screw speed, and Mg and PEG proportions were optimized to achieve a consistent filament diameter of 1.75 mm, meeting 3D printing standards. Extrusion temperature significantly influenced filament diameter by reducing PLA viscosity at higher temperatures. Screw speed impacted diameter uniformity and density, while Mg enhanced filament strength but posed challenges in uniform distribution. PEG improved flexibility, mitigating Mg-induced stiffness. Scanning electron microscopy revealed voids and uneven Mg inclusions, indicating areas for process enhancement. These findings advance the development of optimized biocomposite filaments, providing a foundation for improved fabrication techniques in bone tissue engineering.

Mica is a group of clay minerals that are frequently used to fabricate electrical and thermal insulators and as adsorbents for the treatment of cationic pollutants. However, conventional subtractive manufacturing has the drawback of poor three-dimensional (3D) shape control, which limits its application. In this study, we propose digital light processing (DLP)-based additive manufacturing (AM) as one of the most effective ways to address this drawback. Two major challenges for the ceramic DLP process are the production of a homogeneous and stable slurry with the required rheological properties and the maintenance of printing precision. The mica green body was fabricated using a 53 vol.% solid loading slurry through DLP, which exhibited good dimensional resolution under an exposure energy dose of 10 mJ/cm2. The precise, complex 3D structure was maintained without any defects after debinding and sintering at 1000 °C. The use of ceramic AM to overcome the shape-control limitations of mica demonstrated in this study offers great potential for expanding the applications of mica.

Families of children with Cerebral Palsy (CP) often experience extreme poverty, compounded by limited livelihood opportunities and the added demands of caregiving, which further restrict their ability to earn an income. Targeted livelihood interventions may help improve their economic well-being. This study aimed to assess the cost-effectiveness of livelihood interventions to improve household incomes of ultra-poor families of children with CP in rural Bangladesh. This was a mixed-methods study utilising a subgroup of a pragmatic, open-label, cluster randomised controlled trial (RCT). This subgroup was part of the \"Supporting People in Extreme Poverty with Rehabilitation and Therapy (SUPPORT CP)\" trial (ACTRN12619001750178), which was implemented in three rural subdistricts of Sirajganj district, Bangladesh. This RCT involved 251 children across three arms- integrated microfinance-based livelihood and community-based rehabilitation (IMCBR), community-based rehabilitation (CBR), and care-as-usual. We investigated 80 children with CP whose parents received an IMCBR program as part of the SUPPORT CP trial. Additionally, in-depth interviews were conducted with 21 participants from the IMCBR arm. Descriptive statistics to depict respondent characteristics and the average return on investment (ROI) were calculated to evaluate the most cost-effective livelihood support. Furthermore, thematic analysis was performed with the interview data to explore the advantages and disadvantages of different livelihood products. The parents/caregivers of included children with CP were given five forms of livelihood support: Chickens (n = 3, 15 for each), Sewing machine (n = 11, 1 for each), Ghee making utensils (n = 1, 1 for each), Lamb (n = 7, 2 for each), and Goat (n = 59, 2 for each). The average cost of livelihood intervention per family was 65⸱9 USD. The net return on investment after 12 months was 59.0% for lamb, 70.0% for ghee-making tools, 24.0% for goat, 34.0% for sewing machines, and -25.0% for chicken. Lambs proved to be advantageous due to their sustainability, minimal space requirements, and disease resistance. This study suggests that the provision of lambs as livelihood support is the most effective intervention for empowering ultra-poor families with CP in Bangladesh. This experience can potentially enhance the well-being of ultra-poor families in Bangladesh and other low- and middle-income countries.

The COVID-19 pandemic has impacted national and household food security in Indonesia. The objectives of this study were to: (1) identify the socio-economic characteristics of Indonesian households related to food security, (2) analyze the factors that have affected household food security during the COVID-19 pandemic, and (3) provide recommendations for improving programs to increase household food security. The study was conducted in eight provinces in Indonesia, namely North Sumatra, Lampung, West Java, Central Java, East Java, South Kalimantan, South Sulawesi, and West Nusa Tenggara. Data collection was carried out from April to July 2020. The results showed that 50.63% of the households surveyed were food insecure. The binary-logit-regression-model results showed that variables of gender, age, family size, education, occupation, income, and expenditure on food had a significant effect on household food security status. Variables that had a positive influence on household food security were gender, age, education, occupation, income, and food expenditure. On the other hand, household size had a negative effect on household food security. The marginal effect of gender was 0.035, age was 0.058, education was 0.192, type of work was 0.016, income level was 0.521, and food expenditure was 0.114, while for the number of family members the marginal effect was 15.725. This study was conducted in eight provinces affected by COVID-19, using the Household-Food- Insecurity-Access-Scale and binary-logit model approaches, which had never been performed before. Policy and program recommendations for increasing household food security in Indonesia are presented.

Poverty is a key contributor to delayed diagnosis and limited access to early intervention and rehabilitation for children with cerebral palsy (CP) in rural Bangladesh. 97% of families of children with CP live below the poverty line in Bangladesh. Therefore, in low-and middle-income countries (LMICs), efforts to improve outcomes for children with CP (including health-related quality of life, motor function, communication, and nutritional attainments) should also include measures to improve family economic and social capital. We propose a randomised controlled trial (RCT) to evaluate the effectiveness of an integrated microfinance/livelihood and community-based rehabilitation (IMCBR) program for ultra-poor families of children with CP in rural Bangladesh. This will be a cluster RCT comparing three arms: (a) integrated microfinance/livelihood and community-based rehabilitation (IMCBR); (b) community-based rehabilitation (CBR) alone; and (c) care-as-usual (i.e. no intervention). Seven clusters will be recruited within each arm. Each cluster will consist of 10 child-caregiver dyads totalling 21 clusters with 210 dyads. Parents recruited in the IMCBR arm will take part in a microfinance/livelihood program and Parent Training Module (PTM), their children with CP will take part in a Goal Directed Training (GDT) program. The programs will be facilitated by specially trained Community Rehabilitation Officers. The CBR arm includes the same PTM and GDT interventions excluding the microfinance/livelihood program. The care-as-usual arm will be provided with information about early intervention and rehabilitation. The assessors will be blinded to group allocation. The duration of the intervention will be 12 months; outcomes will be measured at baseline, 6 months, 12 months, and 18 months. This will be the first RCT of an integrated microfinance/livelihood and CBR program for children with CP in LMIC settings. Evidence from the study could transform approaches to improving wellbeing of children with CP and their ultra-poor families.

Purpose>The purpose of this study is to examine how and when supervisors’ bottom-line mentality (BLM) influences workplace cheating behavior. Specifically, the authors draw upon social exchange theory (Blau, 1964) and the negative reciprocity norm (Gouldner, 1960) argument, to explain that supervisor BLM is likely related to organizational cynicism and subsequently those employees may engage in cheating behavior as a way to make things even with the organization. Furthermore, the authors theorized that organizational cynicism and supervisors’ BLM via organizational cynicism, increase cheating behavior among employees with a weak moral identity.Design/methodology/approach>To test the current model, the authors collected data from 232 employees working in various Pakistani firms.Findings>The results affirmed the authors’ moderated-mediation model. The positive indirect effects of supervisors’ BLM on workplace cheating behavior, through organizational cynicism, are moderated by employees’ moral identity.Originality/value>This is the first study that examine the mediating and moderating role of organizational cynicism and employees’ moral identity in the relationship between supervisors’ BLM and workplace cheating behavior.

Due to various concerns about the use of metal-on-metal that is detrimental to users, the use of metal as acetabular cup material was later changed to ultra high molecular weight polyethylene (UHMWPE). However, the wear on UHMWPE releases polyethylene wear particles, which can trigger a negative body response and contribute to osteolysis. For reducing the wear of polyethylene, one of the efforts is to investigate the selection of metal materials. Cobalt chromium molybdenum (CoCrMo), stainless steel 316L (SS 316L), and titanium alloy (Ti6Al4V) are the frequently employed materials. The computational evaluation of contact pressure was carried out using a two-dimensional axisymmetric model for UHMWPE acetabular cup paired with metal femoral head under gait cycle in this study. The results show Ti6Al4V-on-UHMWPE is able to reduce cumulative contact pressure compared to SS 316L-on-UHMWPE and CoCrMo-on-UHMWPE. Compared to Ti6Al4V-on-UHMWPE at peak loading, the difference in cumulative contact pressure to respective maximum contact pressure is 9.740% for SS 316L-on-UHMWPE and 11.038% for CoCrMo-on-UHMWPE.