Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 24
Filtrar
1.
Sci Rep ; 14(1): 12751, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38830919

RESUMO

The study examines the using of Aboodh residual power series method and the Aboodh transform iteration method (ATIM) to analyze modified Korteweg-de Vries equation (mKdV) beside coupled Burger's equations in the framework of the Caputo operator. These sets of equations represent the non-linear wave description for various physical systems. Through APM and ATIM, the solution for the coupled Burger's equations and the mKdV equation get accurate dynamics information that will reveal the nature of their interactions. Using mathematically proven techniques and computational simulations, the developed methods' efficiency and reliability are illustrated in the complex behaviors of these nonlinear wave equations, so that we can gain deeper insights into their complex dynamics. The research is aimed at an increase of the knowledge about the fractional calculus utilization for nonlinear wave motion and it also provides analytical tools for an analysis of wave acting in different scientific and engineering areas.

2.
Sci Rep ; 14(1): 10629, 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38724523

RESUMO

In this manuscript, the well-known stochastic Burgers' equation in under investigation numerically and analytically. The stochastic Burgers' equation plays an important role in the fields of applied mathematics such as fluid dynamics, gas dynamics, traffic flow, and nonlinear acoustics. This study is presented the existence, approximate, and exact stochastic solitary wave results. The existence of results is shown by the help of Schauder fixed point theorem. For the approximate results the proposed stochastic finite difference scheme is constructed. The analysis of the proposed scheme is analyzed by presented the consistency and stability of scheme. The consistency is checked under the mean square sense while the stability condition is gained by the help of Von-Neumann criteria. Meanwhile, the stochastic exact solutions are constructed by using the generalized exponential rational function method. These exact stochastic solutions are obtained in the form of hyperbolic, trigonometric and exponential functions. Mainly, the comparison of both numerical and exact solutions are analyzed via simulations. The unique physical problems are constructed from the newly constructed soliton solutions to compare the numerical results with exact solutions under the presence of randomness. The 3D and line plots are dispatched that are shown the similar behavior by choosing the different values of parameters. These results are the main innovation of this study under the noise effects.

3.
Sci Rep ; 14(1): 10516, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38714736

RESUMO

In this paper, we consider the stochastic fractional Chen Lee Liu model (SFCLLM). We apply the mapping method in order to get hyperbolic, elliptic, rational and trigonometric stochastic fractional solutions. These solutions are important for understanding some fundamentally complicated phenomena. The acquired solutions will be very helpful for applications such as fiber optics and plasma physics. Finally, we show how the conformable derivative order and stochastic term affect the exact solution of the SFCLLM.

4.
Cureus ; 15(5): e39372, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37362519

RESUMO

Our case report confirms adrenal insufficiency following three weeks of monkeypox infection in an immunocompetent patient. As there is no specific treatment for monkeypox, steroid replacement therapy remains the cornerstone of managing adrenal insufficiency. By highlighting the importance of early identification and tracing in our case report, we contribute to the growing body of knowledge on monkeypox and emphasize the importance of identifying adrenal insufficiency and other complications like meningoencephalitis, prompting a significant early intervention that can help manage these complications effectively, potentially improving patient outcomes. In addition, understanding disease progression by tracing monkeypox cases provides valuable information on the disease's natural history, including the timeline and sequence of symptoms, associated complications, and outcomes, to avoid any small chance related to our lack of validated knowledge or incorrect assessment of the disease or the associated complications between an exposure and an effect in the target organs.

5.
Data Brief ; 48: 109160, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37168595

RESUMO

Machine learning (ML) techniques are widely adopted in manufacturing systems for discovering valuable patterns in shopfloor data. In this regard, machine learning models learn patterns in data to optimize process parameters, forecast equipment deterioration, and plan maintenance strategies among other uses. Thus, this article presents the dataset collected from an assembly line known as the FASTory assembly line. This data contains more than 4,000 data samples of conveyor belt motor driver's power consumption. The FASTory assembly line is equipped with web-based industrial controllers and smart 3-phase energy monitoring modules as an expansion to these controllers. For data collection, an application was developed in a timely manner. The application receives a new data sample as JavaScript Object Notation (JSON) every second. Afterwards, the application extracts the energy data for the relevant phase and persists it in a MySQL database for the purpose of processing at a later stage. This data is collected for two separate cases: static case and dynamic case. In the static case, the power consumption data is collected under different loads and belt tension values. This data is used by a prognostic model (Artificial Neural Network (ANN)) to learn the conveyor belt motor driver's power consumption pattern under different belt tension values and load conditions. The data collected during the dynamic case is used to investigate how the belt tension affects the movement of the pallet between conveyor zones. The knowledge obtained from the power consumption data of the conveyor belt motor driver is used to forecast the gradual behavioural deterioration of the conveyor belts used for the transportation of pallets between processing workstations of discrete manufacturing systems.

6.
Public Health Res (Southampt) ; 11(2): 1-185, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-37254700

RESUMO

Background: Link worker social prescribing enables health-care professionals to address patients' non-medical needs by linking patients into various services. Evidence for its effectiveness and how it is experienced by link workers and clients is lacking. Objectives: To evaluate the impact and costs of a link worker social prescribing intervention on health and health-care costs and utilisation and to observe link worker delivery and patient engagement. Data sources: Quality Outcomes Framework and Secondary Services Use data. Design: Multimethods comprising (1) quasi-experimental evaluation of effects of social prescribing on health and health-care use, (2) cost-effectiveness analysis, (3) ethnographic methods to explore intervention delivery and receipt, and (4) a supplementary interview study examining intervention impact during the first UK COVID-19 lockdown (April-July 2020). Study population and setting: Community-dwelling adults aged 40-74 years with type 2 diabetes and link workers in a socioeconomically deprived locality of North East England, UK. Intervention: Link worker social prescribing to improve health and well-being-related outcomes among people with long-term conditions. Participants: (1) Health outcomes study, approximately n = 8400 patients; EuroQol-5 Dimensions, five-level version (EQ-5D-5L), study, n = 694 (baseline) and n = 474 (follow-up); (2) ethnography, n = 20 link workers and n = 19 clients; and COVID-19 interviews, n = 14 staff and n = 44 clients. Main outcome measures: The main outcome measures were glycated haemoglobin level (HbA1c; primary outcome), body mass index, blood pressure, cholesterol level, smoking status, health-care costs and utilisation, and EQ-5D-5L score. Results: Intention-to-treat analysis of approximately 8400 patients in 13 intervention and 11 control general practices demonstrated a statistically significant, although not clinically significant, difference in HbA1c level (-1.11 mmol/mol) and a non-statistically significant 1.5-percentage-point reduction in the probability of having high blood pressure, but no statistically significant effects on other outcomes. Health-care cost estimates ranged from £18.22 (individuals with one extra comorbidity) to -£50.35 (individuals with no extra comorbidity). A statistically non-significant shift from unplanned (non-elective and accident and emergency admissions) to planned care (elective and outpatient care) was observed. Subgroup analysis showed more benefit for individuals living in more deprived areas, for the ethnically white and those with fewer comorbidities. The mean cost of the intervention itself was £1345 per participant; the incremental mean health gain was 0.004 quality-adjusted life-years (95% confidence interval -0.022 to 0.029 quality-adjusted life-years); and the incremental cost-effectiveness ratio was £327,250 per quality-adjusted life-year gained. Ethnographic data showed that successfully embedded, holistic social prescribing providing supported linking to navigate social determinants of health was challenging to deliver, but could offer opportunities for improving health and well-being. However, the intervention was heterogeneous and was shaped in unanticipated ways by the delivery context. Pressures to generate referrals and meet targets detracted from face-to-face contact and capacity to address setbacks among those with complex health and social problems. Limitations: The limitations of the study include (1) a reduced sample size because of non-participation of seven general practices; (2) incompleteness and unreliability of some of the Quality and Outcomes Framework data; (3) unavailability of accurate data on intervention intensity and patient comorbidity; (4) reliance on an exploratory analysis with significant sensitivity analysis; and (5) limited perspectives from voluntary, community and social enterprise. Conclusions: This social prescribing model resulted in a small improvement in glycaemic control. Outcome effects varied across different groups and the experience of social prescribing differed depending on client circumstances. Future work: To examine how the NHS Primary Care Network social prescribing is being operationalised; its impact on health outcomes, service use and costs; and its tailoring to different contexts. Trial registration: This trial is registered as ISRCTN13880272. Funding: This project was funded by the National Institute for Health and Care Research (NIHR) Public Health Research programme, Community Groups and Health Promotion (grant no. 16/122/33) and will be published in full in Public Health Research; Vol. 11, No. 2. See the NIHR Journals Library website for further project information.


Social prescribing happens when health-care staff refer patients to a link worker. Link workers support and help patients to access community services to improve their health and well-being. Social prescribing is popular within the NHS, but there is little evidence that it works. We looked at a social prescribing model being delivered in a disadvantaged area in north-east England.


Assuntos
COVID-19 , Diabetes Mellitus Tipo 2 , Humanos , Adulto , Diabetes Mellitus Tipo 2/tratamento farmacológico , Controle de Doenças Transmissíveis , Inglaterra/epidemiologia , Pessoal de Saúde
7.
Sci Rep ; 13(1): 4870, 2023 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-36964185

RESUMO

In this work, prepared nanoparticle samples of Ni1-xCrx with a fixed ratio of platinum (3%) were synthesized and loaded onto carbon nanofibers, which were produced by an electrospinning technique and carbonized at 900 °C for 7 h in an argon atmosphere. A variety of analysis techniques were applied to examine the stoichiometry, structure, surface morphology, and electrochemical activity. The carbonization process produces carbon nanofibers decorated with metal nanoparticles. Typical fibre diameters are 250-520 nm. The fibre morphologies of the treated samples don't exhibit any overt alterations. A study of the samples' methanol electrocatalytic capabilities was conducted. Cyclic voltammetry, chronoamperometry, and electrochemical impedance measurements were used to investigate catalytic performance and electrode stability as a function of electrolyte concentration, scan rate, and reaction time. The electrooxidation reaction's activation energy is increased, and the electrode's stability is increased, when Cr is added to Ni. In sample C3, the maximum current density (JPE) was 170.3 mA/cm2 at 0.8 V with an onset potential of 0.352 V. Utilizing our electrocatalysts, the electrooxidation of methanol involves a mix of kinetic and diffusion control limiting reactions. This study has shown how to fabricate a powerful Ni-Pt-Cr-based methanol electrooxidation catalyst using a novel approach.

8.
Eur J Health Econ ; 24(3): 399-412, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35688994

RESUMO

OBJECTIVE: We aimed to develop an EQ-5D-5L value set for Romania. METHODS: In line with the EuroQoL standardized valuation protocol, computer-assisted interviews were conducted face-to-face in a representative sample in Romania (November 2018-November 2019). Valuation methods included composite time trade-off and discrete choice experiment tasks. Several models were tested, including models that accounted for data censoring, panel structure of the data, heteroscedasticity, conditional logit, and hybrid models. The final model was selected based on logical consistency, theoretical considerations, and use of all available data. We compared our value set with other value sets from Central and Eastern Europe region. RESULTS: Data from 1493 respondents was used to estimate the value set. A censored hybrid model corrected for heteroscedasticity was selected to represent the value set. The highest decrements in utility were observed for the pain/discomfort dimension (0.375), followed by the mobility dimension (0.293). Health utilities ranged from 1.000 to - 0.323 and 1.3% of the values were negative. The model was corrected with survey weights to better reflect the representativeness of the sample, but the first two coefficients of the self-care dimension stopped being logically consistent. Differences were found between the Romanian, Hungarian and Polish EQ-5D-5L value sets. Good agreement was noted with the Romanian EQ-5D-3L value set, with a swap between pain/discomfort and mobility in ranking of dimensions. CONCLUSION: A value set for EQ-5D-5L is now available for Romania. This will push one-step further the development of health technology assessment and encourage more health-related quality-of-life research to be conducted locally.


Assuntos
Nível de Saúde , Qualidade de Vida , Humanos , Romênia , Inquéritos e Questionários , Polônia
9.
Health Technol Assess ; 26(51): 1-112, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36541454

RESUMO

BACKGROUND: Malnutrition worsens the health of frail older adults. Current treatments for malnutrition may include prescribed oral nutritional supplements, which are multinutrient products containing macronutrients and micronutrients. OBJECTIVE: To assess the effectiveness and cost-effectiveness of oral nutritional supplements (with or without other dietary interventions) in frail older people who are malnourished or at risk of malnutrition. DATA SOURCES: MEDLINE, EMBASE, Cochrane Library, Scopus, CINAHL (Cumulative Index to Nursing and Allied Health Literature) and grey literature were searched from inception to 13 September 2021. REVIEW METHODS: A systematic review and meta-analysis was conducted to evaluate the effectiveness and cost-effectiveness of oral nutritional supplements in frail older people (aged ≥ 65 years) who are malnourished or at risk of malnutrition (defined as undernutrition as per National Institute for Health and Care Excellence guidelines). Meta-analysis and network meta-analysis were undertaken, where feasible, along with a narrative synthesis. A cost-effectiveness review was reported narratively. A de novo model was developed using effectiveness evidence identified in the systematic review to estimate the cost-effectiveness of oral nutritional supplements. RESULTS: Eleven studies (n = 822 participants) were included in the effectiveness review, six of which were fully or partly funded by industry. Meta-analyses suggested positive effects of oral nutritional supplements compared with standard care for energy intake (kcal) (standardised mean difference 1.02, 95% confidence interval 0.15 to 1.88; very low quality evidence) and poor mobility (mean difference 0.03, p < 0.00001, 95% confidence interval 0.02 to 0.04; very low quality evidence) but no evidence of an effect for body weight (mean difference 1.31, 95% confidence interval -0.05 to 2.66; very low quality evidence) and body mass index (mean difference 0.54, 95% confidence interval -0.03 to 1.11; very low quality evidence). Pooled results for other outcomes were statistically non-significant. There was mixed narrative evidence regarding the effect of oral nutritional supplements on quality of life. Network meta-analysis could be conducted only for body weight and grip strength; there was evidence of an effect for oral nutritional supplements compared with standard care for body weight only. Study quality was mixed; the randomisation method was typically poorly reported. One economic evaluation, in a care home setting, was included. This was a well-conducted study showing that oral nutritional supplements could be cost-effective. Cost-effectiveness analysis suggested that oral nutritional supplements may only be cost-effective for people with lower body mass index (< 21 kg/m2) using cheaper oral nutritional supplements products that require minimal staff time to administer. LIMITATIONS: The review scope was narrow in focus as few primary studies used frailty measures (or our proxy criteria). This resulted in only 11 included studies. The small evidence base and varied quality of evidence meant that it was not possible to determine accurate estimates of the effectiveness or cost-effectiveness of oral nutritional supplements. Furthermore, only English-language publications were considered. CONCLUSIONS: Overall, the review found little evidence of oral nutritional supplements having significant effects on reducing malnutrition or its adverse outcomes in frail older adults. FUTURE WORK: Future research should focus on independent, high-quality, adequately powered studies to investigate oral nutritional supplements alongside other nutritional interventions, with longer-term follow-up and detailed analysis of determinants, intervention components and cost-effectiveness. STUDY REGISTRATION: This study is registered as PROSPERO CRD42020170906. FUNDING: This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 51. See the NIHR Journals Library website for further project information.


WHAT WAS THE QUESTION?: Malnutrition, in the form of undernutrition, is very common in frail older people. Dietary advice is recommended (e.g. adding nutrients to meals) for older adults who are malnourished, while powdered or liquid supplements (oral nutritional supplements) can be prescribed to those who are malnourished or at risk of becoming malnourished. In this study, we reviewed previous studies to see if oral nutritional supplements (as a form of dietary support) work at reducing malnutrition in frail older adults and whether or not they are value for money. WHAT DID WE DO?: We searched for studies up to September 2021 on frail older people who were at risk of malnutrition or were malnourished in care homes, hospitals or the community in any country. We included studies that measured malnutrition and the consequences of malnutrition, quality of life, survival, costs and hospitalisations. We assessed the difference in malnutrition between those receiving oral nutritional supplements and those receiving usual care or other dietary (or nutritional) interventions. We also looked at the value for money of oral nutritional supplements. WHAT DID WE FIND?: We found 12 studies (11 studies looking at whether the supplements worked and one study looking at value for money). Most of which were of low quality, and many were funded by industry. Studies often did not report on longer-term effects, or how older people felt about the supplements. There was no clear or strong evidence that oral nutritional supplements worked or were value for money in reducing malnutrition or its consequences (such as the ability to perform everyday tasks). WHAT DOES THIS MEAN?: There is weak evidence for oral nutritional supplements in frail older adults. Future high-quality studies should be independent, assess longer-term effects, and have better reporting on factors that influence the impacts of oral nutritional supplements.


Assuntos
Idoso Fragilizado , Desnutrição , Idoso , Humanos , Qualidade de Vida , Desnutrição/terapia , Análise Custo-Benefício , Peso Corporal
10.
Wellcome Open Res ; 7: 194, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36320450

RESUMO

Background: Requiring access to sensitive data can be a significant obstacle for the development of health models in the Health Economics & Outcomes Research (HEOR) setting. We demonstrate how health economic evaluation can be conducted with minimal transfer of data between parties, while automating reporting as new information becomes available. Methods: We developed an automated analysis and reporting pipeline for health economic modelling and made the source code openly available on a GitHub repository. The pipeline consists of three parts: An economic model is constructed by the consultant using pseudo data. On the data-owner side, an application programming interface (API) is hosted on a server. This API hosts all sensitive data, so that data does not have to be provided to the consultant. An automated workflow is created, which calls the API, retrieves results, and generates a report. Results: The application of modern data science tools and practices allows analyses of data without the need for direct access - negating the need to send sensitive data. In addition, the entire workflow can be largely automated: the analysis can be scheduled to run at defined time points (e.g. monthly), or when triggered by an event (e.g. an update to the underlying data or model code); results can be generated automatically and then be exported into a report. Documents no longer need to be revised manually. Conclusions: This example demonstrates that it is possible, within a HEOR setting, to separate the health economic model from the data, and automate the main steps of the analysis pipeline.

12.
Lancet Healthy Longev ; 3(10): e654-e666, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36116457

RESUMO

BACKGROUND: Current management of malnutrition can include prescribed oral nutritional supplements (ONS); however, there is uncertainty whether these supplements are effective in people who are older (≥65 years) and frail. We assessed the effectiveness, cost-effectiveness, and adherence and acceptability of ONS in frail older people who are malnourished or at risk of malnutrition. METHODS: In this systematic review and meta-analysis, five bibliographic databases (MEDLINE, EMBASE, Cochrane Library, Scopus, and CINAHL) and grey literature sources were searched from inception to Sept 13, 2021, to identify studies assessing the effectiveness and cost-effectiveness of ONS (with or without other dietary interventions) in frail older people who are malnourished or at risk of malnutrition. Multiple reviewers independently did study screening, data extraction, and risk of bias assessment. Quality was assessed using version 1.0 of the Cochrane risk of bias tool for randomised controlled trials (RCTs), and the BMJ Drummond checklist was used to assess the quality of the included cost-effectiveness study. A meta-analysis was done for the effectiveness review; for the other reviews, a narrative synthesis approach was used. This systematic review and meta-analysis was registered on PROSPERO, CRD42020170906. FINDINGS: Of 8492 records retrieved and screened, we included 11 RCTs involving 822 participants, six of which were fully or partly funded by industry. For the majority of the outcomes for which meta-analyses were possible (11/12), Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) assessments suggested that the evidence was of very low certainty. Results suggested that ONS might have a slightly positive effect on energy (kcal) intake (standardised mean difference 1·02 [95% CI 0·15 to 1·88]; I2=87%; four studies), protein intake (standardised mean difference 1·67 [-0·03 to 3·37; I2=97%; four studies), and mobility (mean difference 0·03 [0·02 to 0·04]; I2=0%; four studies), compared with standard care. Narrative syntheses suggested that the effect of ONS on quality of life, compared with standard care, was mixed. In the identified studies, there was very little information related to active components, determinants, or acceptability of interventions. One economic evaluation, done in a care home setting, showed that ONS could be cost-effective. INTERPRETATION: We found little evidence of ONS reducing malnutrition or its associated adverse outcomes in older people who are frail. High-quality, non-industry-funded, adequately powered studies reporting on short-term and long-term health outcomes, determinants, and participant characteristics are needed. FUNDING: UK National Institute of Health and Care Research (NIHR) Health Technology Assessment (NIHR128729).


Assuntos
Idoso Fragilizado , Desnutrição , Idoso , Análise Custo-Benefício , Humanos , Desnutrição/terapia , Qualidade de Vida , Avaliação da Tecnologia Biomédica
13.
Elife ; 112022 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-35731202

RESUMO

Working in Africa provides neuroscientists with opportunities that are not available in other continents. Populations in this region exhibit the greatest genetic diversity; they live in ecosystems with diverse flora and fauna; and they face unique stresses to brain health, including child brain health and development, due to high levels of traumatic brain injury and diseases endemic to the region. However, the neuroscience community in Africa has yet to reach its full potential. In this article we report the outcomes from a series of meetings at which the African neuroscience community came together to identify barriers and opportunities, and to discuss ways forward. This exercise resulted in the identification of six domains of distinction in African neuroscience: the diverse DNA of African populations; diverse flora, fauna and ecosystems for comparative research; child brain health and development; the impact of climate change on mental and neurological health; access to clinical populations with important conditions less prevalent in the global North; and resourcefulness in the reuse and adaption of existing technologies and resources to answer new questions. The article also outlines plans to advance the field of neuroscience in Africa in order to unlock the potential of African neuroscientists to address regional and global mental health and neurological problems.


Assuntos
Ecossistema , Neurociências , África , Criança , Mudança Climática , Saúde Global , Humanos
14.
Sci Rep ; 12(1): 4925, 2022 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-35322077

RESUMO

Favipiravir has antiviral activity against influenza, West Nile virus, and yellow fever virus and against flaviviruses. The objective of this pilot study was to compare three arms: favipiravir; hydroxychloroquine; standard care (no specific SARS-CoV-2 treatment) only, in symptomatic patients infected by SARS-CoV-2 in an open-labelled randomized clinical trial. The trial was registered with Bahrain National Taskforce for Combatting COVID-19 on the 7th of May 2020 (registration code: NCT04387760). 150 symptomatic patients with COVID-19 disease were randomized into one of three arms: favipiravir, hydroxychloroquine, or standard care only. The primary outcome was the clinical scale at the end of study follow up (day 14 or on discharge/death) based on a points scale. The secondary outcomes were viral clearance, biochemical parameter changes and mortality at 30-days. Baseline characteristics did not differ between groups. The proportion of patients who achieved a clinical scale < 2 did not differ between groups. The favipiravir-treated and hydroxychloroquine-treated group showed increased viral clearance (OR, 95%CI 2.38, 0.83-6.78, OR, 95%CI 2.15, 0.78-5.92, respectively) compared to standard care, but this was not significant. The biochemical profile did not differ between groups, except for the platelet count (P < 0.03) and uric acid (P < 0.004) that were higher with favipiravir-treatment. Primary or secondary outcome measures did not differ between favipiravir, hydroxychloroquine, and standard therapy for mild to moderate COVID-19 disease; therefore, whilst favipiravir therapy appeared safe with a trend to increased viral clearance, there was no superior therapeutic utility.Clinical trials registration. NCT04387760. Registration date: 07/05/2020.


Assuntos
Tratamento Farmacológico da COVID-19 , Hidroxicloroquina , Amidas , Humanos , Hidroxicloroquina/uso terapêutico , Projetos Piloto , Pirazinas , SARS-CoV-2
15.
Polymers (Basel) ; 15(1)2022 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-36616457

RESUMO

A casting technique was used to prepare poly(vinyl alcohol) (PVA) blend polymers with different concentrations of Nylon-6,6 to increase the free-volume size and control the ionic conductivity of the blended polymers. The thermal activation energy for some blends is lower than that of pure polymers, indicating that their thermal stability is somewhere in between that of pure Nylon-6,6 and pure PVA. The degree of crystallinity of the blend sample (25.7%) was lower than that of the pure components (41.0 and 31.6% for pure Nylon-6,6 and PVA, respectively). The dielectric properties of the blended samples were investigated for different frequencies (50 Hz-5 MHz). The σac versus frequency was found to obey Jonscher's universal power law. The calculated values of the s parameter were increased from 0.53 to 0.783 for 0 and 100 wt.% Nylon-6,6, respectively, and values less than 1 indicate the hopping conduction mechanism. The barrier height (Wm) was found to increase from 0.33 to 0.72 for 0 and 100 wt.% Nylon-6,6, respectively. The ionic conductivity decreases as the concentration of Nylon-6,6 is blended into PVA because increasing the Nylon-6,6 concentration reduces the number of mobile charge carriers. Positron annihilation lifetime (PAL) spectroscopy was used to investigate the free volume's nanostructure. The hole volume size grows exponentially with the concentration of Nylon-6,6 mixed with PVA. The Nylon-6,6/PVA blends' free-volume distribution indicates that there is no phase separation in the blended samples. Mixing PVA and Nylon-6,6 resulted in a negative deviation (miscible blends), as evidenced by the interaction parameter's negative value. The strong correlation between the free-volume size and other macroscopic properties like ionic conductivity suggests that the free-volume size influences these macroscopic properties.

16.
Sensors (Basel) ; 21(14)2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-34300366

RESUMO

The utilization of robotic systems has been increasing in the last decade. This increase has been derived by the evolvement in the computational capabilities, communication systems, and the information systems of the manufacturing systems which is reflected in the concept of Industry 4.0. Furthermore, the robotics systems are continuously required to address new challenges in the industrial and manufacturing domain, like keeping humans in the loop, among other challenges. Briefly, the keeping humans in the loop concept focuses on closing the gap between humans and machines by introducing a safe and trustworthy environment for the human workers to work side by side with robots and machines. It aims at increasing the engagement of the human as the automation level increases rather than replacing the human, which can be nearly impossible in some applications. Consequently, the collaborative robots (Cobots) have been created to allow physical interaction with the human worker. However, these cobots still lack of recognizing the human emotional state. In this regard, this paper presents an approach for adapting cobot parameters to the emotional state of the human worker. The approach utilizes the Electroencephalography (EEG) technology for digitizing and understanding the human emotional state. Afterwards, the parameters of the cobot are instantly adjusted to keep the human emotional state in a desirable range which increases the confidence and the trust between the human and the cobot. In addition, the paper includes a review on technologies and methods for emotional sensing and recognition. Finally, this approach is tested on an ABB YuMi cobot with commercially available EEG headset.


Assuntos
Robótica , Automação , Eletroencefalografia , Emoções , Humanos , Indústrias
17.
Results Phys ; 26: 104432, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34150484

RESUMO

COVID-19 has become a world wide pandemic since its first appearance at the end of the year 2019. Although some vaccines have already been announced, a new mutant version has been reported in UK. We certainly should be more careful and make further investigations to the virus spread and dynamics. This work investigates dynamics in Lotka-Volterra based Models of COVID-19. The proposed models involve fractional derivatives which provide more adequacy and realistic description of the natural phenomena arising from such models. Existence and boundedness of non-negative solution of the fractional model is proved. Local stability is also discussed based on Matignon's stability conditions. Numerical results show that the fractional parameter has effect on flattening the curves of the coexistence steady state. This interesting foundation might be used among the public health strategies to control the spread of COVID-19 and its mutated versions.

18.
Data Brief ; 35: 106912, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33732826

RESUMO

The vast adoption of machine learning techniques in developing smart solutions increases the need of training and testing data. This data can be either collected from physical systems or created using simulation tools. In this regard, this paper presents a set of data collected using a digital twin known as the FASTory Simulator. The data contains more than 100 K events which are collected during a simulated assembly process. The FASTory simulator is a replica of a real assembly line with web-based industrial controllers. The data have been collected using specific-developed orchestrator. During the simulated process, the orchestrator was able to record all the events that occurred in the system. The provided data contains raw JavaScript Object Notation (JSON) formatted data and filtered Comma Separated Values (CSV) formatted data. This data can be exploited in machine learning for modelling the behaviour of the production systems or as testing data for optimization solution for the production system. Finally, this data has been utilized in a research for comparing different data analysis approaches including Knowledge-based systems and data-based systems.

19.
Preprint em Inglês | medRxiv | ID: ppmedrxiv-20249053

RESUMO

IntroductionCoronavirus disease (COVID-19) caused by the novel coronavirus SARS-CoV-2 is an infectious disease which has evolved into a worldwide pandemic. Growing evidence suggests that individuals with pre-existing comorbidities are at higher risk of a more serious COVID-19 illness. Sickle cell disease (SCD) is an inherited hemoglobinopathy which increases the susceptibility to infections and as a consequent has higher risks of morbidity and mortality. The impact of COVID-19 on SCD patients could lead to further increase in disease severity and mortality. Studies that examine the effect of SCD on COVID-19 outcomes are lacking. This study aims to determine whether SCD is a risk factor for severe COVID-19 infection in regards to the requirement of non-invasive ventilation/high flow nasal cannula (NIV/HFNC), mechanical intubation (MV) or death. MethodsRetrospective cohort study which included COVID-19 patients admitted to four Ministry of Health COVID-19 treatment facilities in Bahrain during the period of 24, February 2020, to 31, July 2020. All SCD patients with COVID-19 were included and compared to randomly selected non-SCD patients with COVID-19. Data for the selected patients were collected from the medical records. Multivariate logistic regression models were used to control for confounders and estimate the effect of SCD on the outcomes. ResultsA total of 1,792 patients with COVID-19 were included; 38 of whom were diagnosed with SCD as well. In the SCD group, one (2.6%) patient required NIV/HFNC, one (2.6%) required MV and one (2.6%) death occurred. In comparison, 56 (3.2%) of the non-SCD patients required NIV/HFNC, 47 (2.7%) required MV and death occurred in 58 (3.3%) patients. Upon adjusting for confounders, SCD had an odds ratio of 1.847 (95% CI: 0.39 - 8.83; p=0.442). ConclusionOur results indicate that SCD is not a risk factor for worse disease outcomes in COVID-19 patients.

20.
Beilstein J Nanotechnol ; 11: 807-813, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32509494

RESUMO

Single-layer vanadium nitride (VN) and bilayer Pd0.96Fe0.04/VN and VN/Pd0.92Fe0.08 thin-film heterostructures for possible spintronics applications were synthesized on (001)-oriented single-crystalline magnesium oxide (MgO) substrates utilizing a four-chamber ultrahigh vacuum deposition and analysis system. The VN layers were reactively magnetron sputtered from a metallic vanadium target in Ar/N2 plasma, while the Pd1- x Fe x layers were deposited by co-evaporation of metallic Pd and Fe pellets from calibrated effusion cells in a molecular beam epitaxy chamber. The VN stoichiometry and Pd1- x Fe x composition were controlled by X-ray photoelectron spectroscopy. In situ low-energy electron diffraction and ex situ X-ray diffraction show that the 30 nm thick single-layer VN as well as the double-layer VN(30 nm)/Pd0.92Fe0.08(12 nm) and Pd0.96Fe0.04(20 nm)/VN(30 nm) structures have grown cube-on-cube epitaxially. Electric resistance measurements demonstrate a metallic-type temperature dependence for the VN film with a small residual resistivity of 9 µΩ·cm at 10 K, indicating high purity and structural quality of the film. The transition to the superconducting state was observed at 7.7 K for the VN film, at 7.2 K for the Pd0.96Fe0.04/VN structure and at 6.1 K for the VN/Pd0.92Fe0.08 structure with the critical temperature decreasing due to the proximity effect. Contrary to expectations, all transitions were very sharp with the width ranging from 25 mK for the VN film to 50 mK for the VN/Pd0.92Fe0.08 structure. We propose epitaxial single-crystalline thin films of VN and heteroepitaxial Pd1- x Fe x /VN and VN/Pd1- x Fe x (x ≤ 0.08) structures grown on MgO(001) as the materials of a choice for the improvement of superconducting magnetic random access memory characteristics.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...