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1.
Clin Chim Acta ; : 119839, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38964570

RESUMO

Immunoassays are important tools in diagnosing giardiasis, though there are several controversies inherent in the existing methods. We conducted a systematic review and meta-analysis to assess the pooled diagnostic accuracy of immunoassays in detecting the gastrointestinal disease-causing parasite Giardia lamblia. Our comprehensive search, which included PubMed, Scopus, and ScienceDirect from 2000 up until 2023, resulted in 34 studies reporting the performance of 24 different immunoassays. The overall pooled sensitivity and specificity of immunoassays and subgroup analyses were determined. Notably, ImmunoCardSTAT® and RIDASCREEN® Giardia were the most used assays (n = 6 studies each). They exhibited sensitivity and specificity of 84 % and 99 % and 93 % and 99 %, respectively. Sub-group analysis on the type of immunoassays (without the case-control studies) showed that commercial ELISA had higher sensitivity (96 %) compared to a commercial immunochromatographic (88 %), which justifies the difference of sensitivity between ImmunoCardSTAT® and RIDASCREEN® Giardia. However, the applicability between these two in clinical settings, replacing the gold standard, should be considered including the time, equipment requirement, and budget. Samples from symptomatic patients showed higher sensitivity (92 %) compared to asymptomatic patients (79 %). Overall, immunoassays can be a practical replacement for the current gold standard, but more information should be gathered regarding the cost of providing more conclusive suggestions on these findings.

2.
Int J Biol Macromol ; 267(Pt 1): 131183, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38580016

RESUMO

Corneal blindness is commonly treated through corneal replacement with allogeneic corneal donors, which may face shortage. Regarding this issue, xenogeneic alternatives are explored. Fish scale-derived scaffolds (FSSs) are among the alternatives due to the lower risk of infection and abundant sources of raw materials. Unfortunately, the information about mechanical, optical, chemical, and biological performances of FSSs for corneal replacements is still scattered, as well as about the fabrication techniques. This study aims to gather scattered pieces of information about the mentioned performances and fabrication techniques of FSSs for corneal replacements. Sorted from four scientific databases and using the PRISMA checklist, eleven relevant articles are collected. FSSs are commonly fabricated using decellularization and decalcification processes, generating FSSs with parallel multilayers or crossed fibers with topographic microchannels. In the collected studies, similar mechanical properties of FSSs to native tissues are discovered, as well as good transparency, light remittance, but poorer refractive indexes than native tissues. Biological evaluations mostly discuss histology, cell proliferations, and immune responses on FSSs, while only a few studies examine the vascularization. No studies completed comprehensive evaluations on the four properties. The current progress of FSS developments demonstrates the potential of FSS use for corneal replacements.


Assuntos
Córnea , Alicerces Teciduais , Animais , Alicerces Teciduais/química , Córnea/cirurgia , Humanos , Transplante de Córnea/métodos , Escamas de Animais/química , Peixes , Engenharia Tecidual/métodos
3.
Sci Rep ; 14(1): 6842, 2024 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-38514731

RESUMO

Previous research has primarily focused on pre-processing parameters such as design, material selection, and printing techniques to improve the strength of 3D-printed prosthetic leg sockets. However, these methods fail to address the major challenges that arise post-printing, namely failures at the distal end of the socket and susceptibility to shear failure. Addressing this gap, the study aims to enhance the mechanical properties of 3D-printed prosthetic leg sockets through post-processing techniques. Fifteen PLA + prosthetic leg sockets are fabricated and reinforced with four materials: carbon fiber, carbon-Kevlar fiber, fiberglass, and cement. Mechanical and microstructural properties of the sockets are evaluated through axial compression testing and scanning electron microscopy (SEM). Results highlight superior attributes of cement-reinforced sockets, exhibiting significantly higher yield strength (up to 89.57% more than counterparts) and higher Young's modulus (up to 76.15% greater). SEM reveals correlations between microstructural properties and socket strength. These findings deepen the comprehension of 3D-printed prosthetic leg socket post-processing, presenting optimization prospects. Future research can focus on refining fabrication techniques, exploring alternative reinforcement materials, and investigating the long-term durability and functionality of post-processed 3D-printed prosthetic leg sockets.


Assuntos
Membros Artificiais , Desenho de Prótese , Implantação de Prótese , Pressão , Fibra de Carbono , Impressão Tridimensional
4.
Heliyon ; 10(4): e26660, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38404809

RESUMO

Previous works had successfully demonstrated the clinical effectiveness of unilateral external fixator in treating various types of fracture, ranging from the simple type, such as oblique and transverse fractures, to complex fractures. However, literature that investigated its biomechanical analyses to further justify its efficacy is limited. Therefore, this paper aimed to analyse the stability of unilateral external fixator for treating different types of fracture, including the simple oblique, AO32C3 comminuted, and 20 mm gap transverse fracture. These fractures were reconstructed at the distal diaphysis of the femoral bone and computationally analysed through the finite element method under the stance phase condition. Findings showed a decrease in the fixation stiffness in large gap fracture (645.2 Nmm-1 for oblique and comminuted, while 23.4 Nmm-1 for the gap fracture), which resulted in higher displacement, IFM and stress distribution at the pin bone interface. These unfavourable conditions could consequently increase the risk of delayed union, pin loosening and infection, as well as implant failure. Nevertheless, the stress observed on the fracture surfaces was relatively low and in controlled amount, indicating that bone unity is still allowable in all models. Briefly, the unilateral fixation may provide desirable results in smaller fracture gap, but its usage in larger gap fracture might be alarming. These findings could serve as a guide and insight for surgeons and researchers, especially on the biomechanical stability of fixation in different fracture types and how will it affect bone unity.

5.
PLoS One ; 19(2): e0298738, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38412167

RESUMO

INTRODUCTION: Wireless communication connects billions of people worldwide, relying on radiofrequency electromagnetic fields (RF-EMF). Generally, fifth-generation (5G) networks shift RF carriers to higher frequencies. Although radio, cell phones, and television have benefitted humans for decades, higher carrier frequencies can present potential health risks. Insects closely associated with humans (such as mosquitoes) can undergo increased RF absorption and dielectric heating. This process inadvertently impacts the insects' behaviour, morphology, and physiology, which can influence their spread. Therefore, this study examined the impact of RF exposure on Ae. aegypti mosquitoes, which are prevalent in indoor environments with higher RF exposure risk. The morphologies of Ae. aegypti eggs and their developments into Ae. aegypti mosquitoes were investigated. METHODS: A total of 30 eggs were exposed to RF radiation at three frequencies: baseline, 900 MHz, and 18 GHz. Each frequency was tested in triplicate. Several parameters were assessed through daily observations in an insectarium, including hatching responses, development times, larval numbers, and pupation periods until the emergence of adult insects. RESULTS: This study revealed that the hatching rate for the 900 MHz group was the highest (79 ± 10.54%) compared to other exposures (p = 0.87). The adult emergence rate for the 900 MHz group was also the lowest at 33 ± 2.77%. A significant difference between the groups was demonstrated in the statistical analysis (p = 0.03). CONCLUSION: This work highlighted the morphology sensitivity of Ae. aegypti eggs and their developments in the aquatic phase to RF radiation, potentially altering their life cycle.


Assuntos
Aedes , Animais , Adulto , Humanos , Aedes/fisiologia , Larva , Comunicação , Ondas de Rádio/efeitos adversos
6.
Simul Healthc ; 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38329823

RESUMO

INTRODUCTION: Manikins are tools used in simulation training for medical students to develop important skills, one of which is immunization. However, conventional manikins often do not resemble the actual size of an infant's arm or leg. This study aimed to determine the impact of using actual-size manikins on students' knowledge and practical skills, evaluate their confidence in immunization practice, and assess students' responses and feedback regarding the practice using actual-size manikins. METHODS: This was a quasi-experimental study involving medical students at the Faculty of Medicine, Universitas Indonesia, from October 2020 to April 2021. Students in the intervention group used newly developed actual-size infant arm and leg manikins, while the control group used conventional manikins. All students underwent the objective structured clinical examination (OSCE) and the scores were compared between the 2 groups. Within the intervention group, data on pretest and posttest scores, feedback questionnaires, and self-confidence assessments were also obtained and analyzed. RESULTS: A total of 205 students were included. Statistically significant difference was found in the OSCE scores between the intervention and control groups (P < 0.01). Students in the intervention group (n = 108) showed significant improvement in knowledge scores after the workshop (P < 0.01). Most students (81.7%) expressed confidence in administering vaccines to live patients after practicing with manikins. In addition, 98.2% of students (n = 107) acknowledged the benefits of practicing with actual-size manikins in accurately determining the injection sites. CONCLUSIONS: Simulation with the actual-size manikins significantly improved students' knowledge and practical immunization skills, leading to increased confidence and competence in their immunization skills.

7.
Adv Mater ; 36(11): e2311458, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38059415

RESUMO

The reversal of halide ions is studied under various conditions. However, the underlying mechanism of heat-induced reversal remains unclear. This work finds that dynamic disorder-induced localization of self-trapped polarons and thermal disorder-induced strain (TDIS) can be co-acting drivers of reverse segregation. Localization of polarons results in an order of magnitude decrease in excess carrier density (polaron population), causing a reduced impact of the light-induced strain (LIS - responsible for segregation) on the perovskite framework. Meanwhile, exposing the lattice to TDIS exceeding the LIS can eliminate the photoexcitation-induced strain gradient, as thermal fluctuations of the lattice can mask the LIS strain. Under continuous 0.1 W cm⁻2 illumination (upon segregation), the strain disorder is estimated to be 0.14%, while at 80 °C under dark conditions, the strain is 0.23%. However, in situ heating of the segregated film to 80 °C under continuous illumination (upon reversal) increases the total strain disorder to 0.25%, where TDIS is likely to have a dominant contribution. Therefore, the contribution of entropy to the system's free energy is likely to dominate, respectively. Various temperature-dependent in situ measurements and simulations further support the results. These findings highlight the importance of strain homogenization for designing stable perovskites under real-world operating conditions.

8.
PLoS One ; 18(12): e0293890, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38064428

RESUMO

In the era of globalization, financial development plays a key role in socioeconomic and environmental development. However, its adverse consequences on human life, environmental hazards, and high energy consumption cannot be ignored. Thus, this study investigates the non-linear relationship between globalization, financial development, and energy consumption for BRICS economies. In doing so, we have applied second-generation tests to identify cross-sectional dependence in the data. Cross-sectional augmented Dickey-Fuller (CADF) and Cross-sectional Im-Pesaran Shin (CIPS) have been performed to find the stationary level of variables. The long-term equilibrium link between the investigated variables has been established in continuance using the Westerlund Cointegration test. The Dynamic Seemingly Unrelated Regression (DSUR) indicates that U-shaped relationships exist for financial development and globalization with energy consumption. Conversely, there is an inverted U-shaped relationship exist between economic growth and energy consumption in BRICS. The Dumitrescu-Hurlin panel causality test findings show that a unidirectional link runs from energy consumption to financial development, economic growth to energy consumption, and globalization towards energy usage. Important policy implications have also been discussed.


Assuntos
Dióxido de Carbono , Desenvolvimento Econômico , Humanos , Estudos Transversais , Internacionalidade , Políticas , Energia Renovável
9.
J Autism Dev Disord ; 2023 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-37987948

RESUMO

PURPOSE: Accepting and adapting to the child's diagnosis of Autism Spectrum Disorder (ASD) can be challenging for parents. We aimed to assess domains of parental adjustment namely despair, self-blame, and acceptance among parents whose children were diagnosed with ASD. METHODS: A cross-sectional study was conducted among 111 parents of children with autism who attended Child and Adolescent Psychiatry Unit (CAPU), in a university teaching hospital in Kuala Lumpur, Malaysia. Sociodemographic profiles of both parents and children were gathered. Parental adjustment focusing on parental self-blame, despair and acceptance were assessed using self-reported questionnaires namely Adjustment to the Diagnosis of Autism (ADA). RESULTS: Higher level of despair was associated with parents who have medical illness (ß = 0.214, p = 0.016) and children who received antipsychotic medications (ß = 0.329, p < 0.001). Parents with tertiary education (ß = -0.207, p = 0.023) and those with autistic child attended school (ß = -0.200, p = 0.037) have lower level of despair. Parents with medical illness (ß = 0.245, p = 0.008), child receiving antipsychotic medications (ß = 0.251, p = 0.005), Chinese ethnicity (ß = 0.185, p = 0.04), and child's gender (ß = 0.283, p = 0.003) were significantly associated with higher level of self-blame. Lower acceptance was found among Chinese parents (ß = -0.264, p = 0.005) while married parents had higher acceptance levels (ß = 0.215, p = 0.022). CONCLUSION: Parental adjustment involving domains of despair, self-blame, and acceptance were significantly associated with ethnicity of parents, educational level, parents' marital status and medical illness, as well as the ASD children's schooling status and type of medications used.

10.
PeerJ Comput Sci ; 9: e1623, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37869451

RESUMO

Due to global warming and climate change, the poultry industry is heavily impacted, especially the broiler industry, due to the sensitive immune system of broiler chickens. However, the continuous monitoring and controlling of the farm's environmental parameters can help to curtail the negative impacts of the environment on chickens' health, leading to increased meat production. This article presents smart solutions to such issues, which are practically implemented, and have low production and operational costs. In this article, an Internet of Things (IoT) based environmental parameters monitoring has been demonstrated for the poultry farmhouse. This system enables the collection and visualization of crucially sensed data automatically and reliably, and at a low cost to efficiently manage and operate a poultry farm. The proposed IoT-based remote monitoring system collects and visualizes environmental parameters, such as air temperature, relative humidity (RH), oxygen level (O2), carbon dioxide (CO2), carbon monoxide (CO), and ammonia (NH3) gas concentrations. The wireless sensor nodes have been designed and deployed for efficient data collection of the essential environmental parameters that are key for monitoring and decision-making process. The hardware is implemented and deployed successfully at a site within the control shed of the poultry farmhouse. The results revealed important findings related to the environmental conditions within the poultry farm. The temperature inside the control sheds remained within the desired range throughout the monitoring period, with daily average values ranging from 32 °C to 34 °C. The RH showed slight variations monitoring period, ranging from 65% to 75%, with a daily average of 70%. The O2 concentration exhibited an average value of 17% to 18.5% throughout the monitoring period. The CO2 levels showed occasional increases, reaching a maximum value of 1,100 ppm. However, this value was below the maximum permissible level of 2,500 ppm, indicating that the ventilation system was effective in maintaining acceptable CO2 levels within the control sheds. The NH3 gas concentration remained consistently low throughout the duration, with an average value of 50 parts per million (ppm).

11.
Front Psychiatry ; 14: 1218715, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37840803

RESUMO

Interpersonal psychotherapy (IPT) is a highly regarded evidence-based psychotherapy that aims to alleviate the suffering of clients and improve their interpersonal functioning. Research has demonstrated the effectiveness of IPT in depressive, bipolar and eating disorders. IPT also focuses on grief and loss as a problem area to help clients address and process their grief symptoms, leading them to reach a phase of finding meaning. However, traumatic grief which is characterized by someone who has both symptoms of trauma and grief can further complicate treatment. As for Posttraumatic Stress Disorder (PTSD), IPT can be a choice of treatment by addressing perceived isolation and emotional dysregulation through mobilizing adequate social support. This case study highlights the efficacy of IPT in treating complicated grief with traumatic experiences caused by the loss of a loved one during the COVID-19 pandemic, without undergoing exposure-based therapy. The treatment course consisted of 12 sessions scheduled twice weekly, and the client received antidepressant medication augmented with antipsychotic medication. After undergoing IPT, the client experienced an improvement in symptoms, gradual recovery of functional disability, and more meaningful interpersonal relationships. The case study presented provides evidence to suggest that IPT is a promising treatment approach for individuals struggling with trauma related to grief.

12.
Cureus ; 15(9): e46180, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37905281

RESUMO

Purpose The purpose of this study is to retrospectively analyze single-operation success (SOS) rates of pneumatic retinopexy (PR) for the treatment of rhegmatogenous retinal detachment (RRD) and to identify the predictors of treatment outcomes. Methods Sixty-one eyes of 61 patients who underwent PR for RRD during a period of 12 years were included in this study. Patient demographics along with pre-treatment clinical characteristics were recorded. Treatment outcomes in terms of best-corrected visual acuity (BCVA) and anatomical characteristics were reported including any post-operative complications. Visual outcomes were compared according to pre-treatment characteristics and between groups of the eyes achieving SOS and those requiring additional surgery. Results SOS was achieved in 37 (61%) eyes. Twenty-four (39%) eyes required one (36%) or two (3%) additional procedures. There was no significant association between pre-treatment characteristics and treatment failure. SOS eyes had significantly better visual outcomes (P=0.002), and so did those with macula-on status (P=0.003). New/missed breaks (9.8%) and proliferative vitreoretinopathy (PVR) (4.9%) were the most common causes of failure. Conclusions We found PR to be a beneficial technique for the treatment of RRD in this cohort. PR remains the least invasive treatment modality, and as a cost-effective technique, it is especially useful in low/middle-income countries such as Pakistan.

13.
Artigo em Inglês | MEDLINE | ID: mdl-37858012

RESUMO

Since the end of the twentieth century, the world has observed a considerable upsurge in carbon emissions as several countries have surfaced as industrial centers and production monsters worldwide. The present study contributes to the existing literature examining the effects of carbon-based emissions, industrial value added, trade openness, transport services, railway lines, and globalization index on per capita GDP growth in China. The study covers a period of 40 years, from 1982 to 2021, introducing the impact of railway transport on GDP growth in contemporary environmental empirics. A vector error correction model (VECM) was applied to achieve the study's envisaged objectives. The findings of this study reveal that carbon emissions are responsible for the reduction of per capita GDP growth in China. On the contrary, industrial value added, transport services, railway lines, and globalization index positively support the per capita GDP growth-dependent variable. The study proposes that pragmatic policies are needed to control pollution resulting from carbon emissions. The eventual effect of maintaining greenhouse gases is expected to assist in achieving sustainable growth of per capita GDP leading to the accomplishment of sustainable development goals in the economy.

14.
Sensors (Basel) ; 23(13)2023 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-37447678

RESUMO

The advancements and reliance on digital data necessitates dependence on information technology. The growing amount of digital data and their availability over the Internet have given rise to the problem of information security. With the increase in connectivity among devices and networks, maintaining the information security of an asset has now become essential for an organization. Intrusion detection systems (IDS) are widely used in networks for protection against different network attacks. Several machine-learning-based techniques have been used among researchers for the implementation of anomaly-based IDS (AIDS). In the past, the focus primarily remained on the improvement of the accuracy of the system. Efficiency with respect to time is an important aspect of an IDS, which most of the research has thus far somewhat overlooked. For this purpose, we propose a multi-layered filtration framework (MLFF) for feature reduction using a statistical approach. The proposed framework helps reduce the detection time without affecting the accuracy. We use the CIC-IDS2017 dataset for experiments. The proposed framework contains three filters and is connected in sequential order. The accuracy, precision, recall and F1 score are calculated against the selected machine learning models. In addition, the training time and the detection time are also calculated because these parameters are considered important in measuring the performance of a detection system. Generally, decision tree models, random forest methods, and artificial neural networks show better results in the detection of network attacks with minimum detection time.


Assuntos
Filtração , Tecnologia da Informação , Internet , Aprendizado de Máquina , Redes Neurais de Computação
15.
PLoS One ; 18(7): e0283862, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37506072

RESUMO

BACKGROUND AND AIMS: There is growing evidence on the contribution of psychological factors to internet addiction; yet it remains inconsistent and deserves further exploration. The aim of this study was to determine the relationship between the psychological symptoms (Attention Deficit Hyperactivity Disorder (ADHD) symptoms, stress, depression, anxiety and loneliness) and internet addiction (IA) among the university students in Malaysia. MATERIALS AND METHODS: A total of 480 students from different faculties in a Malaysian public university participated in this study. They were selected by simple random sampling method. They completed self-administered questionnaires including the Malay Version of Internet Addiction Test (MVIAT)) to measure internet addiction and Adult Self-Report Scale (ASRS) Symptom Checklist, Depression Anxiety Stress Scales (DASS) and UCLA Loneliness Scale (Version 3) to assess for ADHD symptoms, depression, anxiety, stress, and loneliness respectively. RESULTS: The prevalence of IA among university students was 33.33% (n = 160). The respondents' mean age was 21.01 ± 1.29 years old and they were predominantly females (73.1%) and Malays (59.4%). Binary logistic regression showed that gender (p = 0.002; OR = 0.463, CI = 0.284-0.754), ADHD inattention (p = 0.003; OR = 2.063, CI = 1.273-3.345), ADHD hyperactivity (p<0.0001; OR = 2.427, CI = 1.495-3.939), stress (p = 0.048; OR = 1.795, CI = 1.004-3.210) and loneliness (p = 0.022; OR = 1.741, CI = 1.084-2.794) were significantly associated with IA. CONCLUSION: A third of university students had IA. In addition, we found that those who were at risk of IA were males, with ADHD symptoms of inattention and hyperactivity, who reported stress and loneliness. Preventive strategy to curb internet addiction and its negative sequelae may consider these factors in its development and implementation.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade , Comportamento Aditivo , Masculino , Adulto , Feminino , Humanos , Adulto Jovem , Malásia/epidemiologia , Transtorno do Deficit de Atenção com Hiperatividade/psicologia , Universidades , Transtorno de Adição à Internet , Comportamento Aditivo/complicações , Comportamento Aditivo/epidemiologia , Comportamento Aditivo/diagnóstico , Ansiedade/diagnóstico , Estudantes/psicologia , Internet
16.
Materials (Basel) ; 16(9)2023 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-37176180

RESUMO

Total hip arthroplasty (THA) is most likely one of the most successful surgical procedures in medicine. It is estimated that three in four patients live beyond the first post-operative year, so appropriate surgery is needed to alleviate an otherwise long-standing suboptimal functional level. However, research has shown that during a complete THA procedure, a solid hip implant inserted in the femur can damage the main arterial supply of the cortex and damage the medullary space, leading to cortical bone resorption. Therefore, this study aimed to design a porous hip implant with a focus on providing more space for better osteointegration, improving the medullary revascularisation and blood circulation of patients. Based on a review of the literature, a lightweight implant design was developed by applying topology optimisation and changing the materials of the implant. Gyroid and Voronoi lattice structures and a solid hip implant (as a control) were designed. In total, three designs of hip implants were constructed by using SolidWorks and nTopology software version 2.31. Point loads were applied at the x, y and z-axis to imitate the stance phase condition. The forces represented were x = 320 N, y = -170 N, and z = -2850 N. The materials that were used in this study were titanium alloys. All of the designs were then simulated by using Marc Mentat software version 2020 (MSC Software Corporation, Munich, Germany) via a finite element method. Analysis of the study on topology optimisation demonstrated that the Voronoi lattice structure yielded the lowest von Mises stress and displacement values, at 313.96 MPa and 1.50 mm, respectively, with titanium alloys as the materials. The results also indicate that porous hip implants have the potential to be implemented for hip implant replacement, whereby the mechanical integrity is still preserved. This result will not only help orthopaedic surgeons to justify the design choices, but could also provide new insights for future studies in biomechanics.

17.
Waste Manag ; 166: 25-34, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37141784

RESUMO

Industrial plastic waste is growing globally at an alarming rate and environmental pollution from traditional landfill disposal and incineration treatments are of great concern. As a strategy to reduce plastic pollution, value-added composite materials from industrial plastic wastes reinforced with recycled nylon fibers for use in floor paving tile applications were developed. This is to address the disadvantages of existing ceramic tiles which are relatively heavy, brittle, and expensive. The plastic waste composite structures were produced via compression molding technique at an optimized randomly oriented constant fiber volume fraction of 50 wt% after the initial sorting, cleaning, drying, pulverizing, and melt-mixing. The molding temperature, pressure, and time for the composite's structures were 220 ℃, 65 kg.cm-3, and 5 min respectively. The composites' thermal, mechanical, and microstructural properties were characterized in accordance with appropriate ASTM standards. From the results obtained, the differential scanning calorimetry (DSC) of mixed plastic wastes and nylon fiber wastes showed a processing temperature range of 130-180 ℃, and 250 ℃ respectively. Thermal degradation temperature (TGA) of the plastic and nylon fiber waste composites were stable above 400 ℃ with maximum bending strength, however, the reinforced plastic waste sandwiched composite structures had outstanding mechanical properties indicating unique characteristics suitable for floor paving tiles. Hence, the current research has developed tough and lightweight tiles composites that are economically viable, and their application will contribute to the development of the building and construction sectors thereby reducing about 10-15% of annual plastic waste generation and a sustainable environment.


Assuntos
Resíduos Industriais , Plásticos , Resíduos Industriais/análise , Nylons , Incineração , Temperatura
18.
Nanomaterials (Basel) ; 13(5)2023 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-36903783

RESUMO

Enhancing the participation of the lattice oxygen mechanism (LOM) in several perovskites to significantly boost the oxygen evolution reaction (OER) is daunting. With the rapid decline in fossil fuels, energy research is turning toward water splitting to produce usable hydrogen by significantly reducing overpotential for other half-cells' OER. Recent studies have shown that in addition to the conventional adsorbate evolution mechanism (AEM), participation of LOM can overcome their prevalent scaling relationship limitations. Here, we report the acid treatment strategy and bypass the cation/anion doping strategy to significantly enhance LOM participation. Our perovskite demonstrated a current density of 10 mA cm-2 at an overpotential of 380 mV and a low Tafel slope (65 mV dec-1) much lower than IrO2 (73 mV dec-1). We propose that the presence of nitric acid-induced defects regulates the electronic structure and thereby lowers oxygen binding energy, allowing enhanced LOM participation to boost OER significantly.

19.
Simul Healthc ; 18(2): 135-143, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35363667

RESUMO

INTRODUCTION: Pap smear training is commonly conducted using simulators before practicing with humans. Unfortunately, existing simulators do not well simulate the biomechanical properties of pelvic tissues, and this may negatively impact the training outcome. In this study, we used finite element analysis (FEA) to identify a material that most accurately simulates pelvic tissues in terms of biomechanical properties for fabricating gynecologic training simulators. The selected material was then used to fabricate a vagina and cervix model using a hybrid technique of fused deposition modeling and molding to qualitatively confirm the structural integrity of the simulator. METHODS: The vagina and cervix were reconstructed in a 3-dimensional feature according to geometrical parameters reported in the literature. The biomechanical compliance of the simulators was investigated by comparing 5 materials-RTV615, Dragon Skin 10, Dragon Skin 30, Dragon Skin FX-Pro, and Ecoflex 00-30-and a pelvic tissue model (control) using 2 FEA modules. The structural mechanics module simulated the insertion and opening of a vaginal speculum, and the (1) horizontal opening of the vagina and peak von Mises stress at the anterior and (2) posterior walls of the vagina were obtained. The explicit dynamics module estimated (1) the fracture stress during punch biopsies and (2) maximum perpendicular deformation of the cervix before break. The most biomechanically compliant material was subsequently used to fabricate the simulator using the hybrid technique. RESULTS: From the FEA, the horizontal opening of the vagina, peak von Mises stress at the anterior wall of the vagina, peak von Mises stress at the posterior wall of the vagina fracture stress, and maximum perpendicular deformation of the cervix before break were obtained; the results of Dragon Skin 10 and the control were most similar. Therefore, the simulator was fabricated using the material. A qualitative evaluation of the simulator by the naked eye verified its structural integrity. CONCLUSIONS: Of the materials studied, the FEA results showed that Dragon Skin 10 was the most accurate material for simulating pelvic tissues in terms of the biomechanical properties in a gynecologic training simulator. The simulator was also successfully fabricated using the hybrid technique. Further studies may also involve experimental testing to support the simulation results.


Assuntos
Colo do Útero , Vagina , Humanos , Feminino , Simulação por Computador
20.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-996577

RESUMO

@#Medical implants are normally used in clinical practice to treat most orthopaedics situations involving bone fractures, deformities, dislocation, and lengthening. It should be noted that specific measures regarding biomechanical and biomaterial characteristics are required for a successful post-surgery procedure. Biomechanical evaluations on the medical implants could be performed by utilising computer and engineering technology. One of them is in silico studies using finite element method that could be simulated in high-performance computer. However, various assumptions are required in computer simulation, such as the constraints on data input and computer resources. This review paper discusses current approaches of constructing a finite element model of human bone with specific material properties for upper limb such as the shoulder joint, humerus, elbow joint, radius and wrist joint. Previous related literatures were reviewed from selected keywords and search engines. To narrow the literature search in this study, inclusion and exclusion criteria of the literature searching were applied. We looked at the current level of knowledge in this field and offered recommendations for future study. In conclusion, studies from previous literature have demonstrated several ways for developing mathematical models and simulating medical implants.

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