Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
1.
Jpn J Radiol ; 42(2): 145-157, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37733205

RESUMO

The effectiveness and precision of disease diagnosis and treatment have increased, thanks to developments in clinical imaging over the past few decades. Science is developing and progressing steadily in imaging modalities, and effective outcomes are starting to show up as a result of the shorter scanning periods needed as well as the higher-resolution images generated. The choice of one clinical device over another is influenced by technical disparities among the equipment, such as detection medium, shorter scan time, patient comfort, cost-effectiveness, accessibility, greater sensitivity and specificity, and spatial resolution. Lately, computational algorithms, artificial intelligence (AI), in particular, have been incorporated with diagnostic and treatment techniques, including imaging systems. AI is a discipline comprised of multiple computational and mathematical models. Its applications aided in manipulating sophisticated data in imaging processes and increased imaging tests' accuracy and precision during diagnosis. Computed tomography (CT), positron emission tomography (PET), and Single Photon Emission Computed Tomography (SPECT) along with their corresponding radiation detectors have been reviewed in this study. This review will provide an in-depth explanation of the above-mentioned imaging modalities as well as the radiation detectors that are their essential components. From the early development of these medical instruments till now, various modifications and improvements have been done and more is yet to be established for better performance which calls for a necessity to capture the available information and record the gaps to be filled for better future advances.


Assuntos
Inteligência Artificial , Tomografia por Emissão de Pósitrons , Humanos , Tomografia por Emissão de Pósitrons/métodos , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Tomografia Computadorizada por Raios X/métodos , Sensibilidade e Especificidade
2.
Biomed Phys Eng Express ; 10(3)2024 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-38513277

RESUMO

Iron oxide nanoparticles (Fe2O3NPs) were synthesized utilizingMentha spicatasourced from Cyprus as a stabilizing agent. The study delved into assessing the antimicrobial, cytotoxic, anti-proliferative, and anti-migratory potential of Fe2O3 NPs through disc diffusion, trypan blue, and 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay, respectively. Characterization of the synthesized Fe2O3 NPs was conducted using Fourier-transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), UV-vis spectroscopy (UV-vis), scanning electron microscopy (SEM), and energy-dispersive x-ray spectroscopy (EDX). The FTIR, XRD, and SEM-EDX spectra confirmed the successful formation of Fe2O3 NPs. The analysis of UV-vis spectra indicates an absorption peak at 302 nm, thereby confirming both the successful synthesis and remarkable stability of the nanoparticles. The nanoparticles exhibited uniform spherical morphology and contained Fe, O, and N, indicating the synthesis of Fe2O3NPs. Additionally, the Fe2O3NPs formed through biosynthesis demonstrated antimicrobial capabilities againstEscherichia coliandBacillus cereus. The significant anti-migratory potential on MDA-MB 231 human breast cancer cells was observed with lower concentrations of the biosynthesized Fe2O3NPs, and higher concentrations revealed cytotoxic effects on the cells with an IC50of 95.7µg/ml. Stable Fe2O3NPs were synthesized usingMentha spicataaqueous extract, and it revealed antimicrobial activity onE. coliandB. cereus, cytotoxic, anti-proliferative and anti-migratory effect on highly metastatic human breast cancer cell lines.


Assuntos
Anti-Infecciosos , Neoplasias da Mama , Nanopartículas Metálicas , Humanos , Feminino , Compostos Férricos/química , Nanopartículas Metálicas/química , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier , Neoplasias da Mama/tratamento farmacológico , Nanopartículas Magnéticas de Óxido de Ferro
3.
Diagnostics (Basel) ; 14(4)2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38396419

RESUMO

One of the most challenging and prevalent side effects of LVAD implantation is that of right heart failure (RHF) that may develop afterwards. The purpose of this study is to review and highlight recent advances in the uses of AI in evaluating RHF after LVAD implantation. The available literature was scanned using certain key words (artificial intelligence, machine learning, left ventricular assist device, prediction of right heart failure after LVAD) was scanned within Pubmed, Web of Science, and Google Scholar databases. Conventional risk scoring systems were also summarized, with their pros and cons being included in the results section of this study in order to provide a useful contrast with AI-based models. There are certain interesting and innovative ML approaches towards RHF prediction among the studies reviewed as well as more straightforward approaches that identified certain important predictive clinical parameters. Despite their accomplishments, the resulting AUC scores were far from ideal for these methods to be considered fully sufficient. The reasons for this include the low number of studies, standardized data availability, and lack of prospective studies. Another topic briefly discussed in this study is that relating to the ethical and legal considerations of using AI-based systems in healthcare. In the end, we believe that it would be beneficial for clinicians to not ignore these developments despite the current research indicating more time is needed for AI-based prediction models to achieve a better performance.

4.
Heliyon ; 10(8): e28770, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38644846

RESUMO

The urgent need to mitigate the severe environmental impacts of climate change necessitates a transition to a low-carbon energy infrastructure, crucial for decarbonization and achieving global sustainability goals. This study investigates the decarbonization trajectories of five major economies and significant carbon emitters: the United States of America (USA), China, Japan, Germany, and India. We focus on evaluating two decarbonization scenarios for power generation. Scenario 1 explores the use of a generic storage system for reducing critical excess electricity production (CEEP), maintaining the same thermal power plant capacity as in the reference year 2021. In contrast, Scenario 2 models thermal power plants to meet the exact electricity demand without introducing a new electricity storage system. The primary aim is to assess the feasibility and implications of achieving a 100% share of renewable and nuclear energy by 2030 and 2050 in these countries. EnergyPLAN software was utilized to model and simulate the electricity systems of these countries. The two scenarios represent different degrees of renewable energy integration, demonstrating possible transitional pathways towards an environmentally friendly electricity generation system. The study provides a comparative analysis of the outcomes for each country, focusing on carbon emissions reduction and the impact on annual total costs in 2030 and 2050. Results show that by 2030, China could reduce its emissions by 88.5% and 85.14% in Scenarios 1 and 2, relative to 2021 levels. From the two scenarios considered in all the countries, India records the highest percentage reduction while Germany has the least percentage emission in reference to 2021, with a potential decrease of 90.63% and 52.42% respectively. By 2050, carbon emissions in the USA will be reduced by 83% and 79.8% using Scenario 1 and Scenario 2 decarbonization pathways. This research significantly contributes to understanding the decarbonization potential of global electricity generation. It provides vital data for policymakers, energy planners, and stakeholders involved in developing sustainable energy policies.

5.
Sci Rep ; 14(1): 6737, 2024 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-38509174

RESUMO

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a single-stranded RNA virus that caused the outbreak of the coronavirus disease 2019 (COVID-19). The COVID-19 outbreak has led to millions of deaths and economic losses globally. Vaccination is the most practical solution, but finding epitopes (antigenic peptide regions) in the SARS-CoV-2 proteome is challenging, costly, and time-consuming. Here, we proposed a deep learning method based on standalone Recurrent Neural networks to predict epitopes from SARS-CoV-2 proteins easily. We optimised the standalone Bidirectional Long Short-Term Memory (Bi-LSTM) and Bidirectional Gated Recurrent Unit (Bi-GRU) with a bioinspired optimisation algorithm, namely, Bee Colony Optimization (BCO). The study shows that LSTM-based models, particularly BCO-Bi-LSTM, outperform all other models and achieve an accuracy of 0.92 and AUC of 0.944. To overcome the challenge of understanding the model predictions, explainable AI using the Shapely Additive Explanations (SHAP) method was employed to explain how Blackbox models make decisions. Finally, the predicted epitopes led to the development of a multi-epitope vaccine. The multi-epitope vaccine effectiveness evaluation is based on vaccine toxicity, allergic response risk, and antigenic and biochemical characteristics using bioinformatic tools. The developed multi-epitope vaccine is non-toxic and highly antigenic. Codon adaptation, cloning, gel electrophoresis assess genomic sequence, protein composition, expression and purification while docking and IMMSIM servers simulate interactions and immunological response, respectively. These investigations provide a conceptual framework for developing a SARS-CoV-2 vaccine.


Assuntos
COVID-19 , Vacinas Virais , Abelhas , Humanos , Animais , Vacinas contra COVID-19 , COVID-19/prevenção & controle , SARS-CoV-2 , Epitopos de Linfócito B , Epitopos de Linfócito T , Biologia Computacional/métodos , Simulação de Acoplamento Molecular
6.
Sci Rep ; 14(1): 10375, 2024 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-38710737

RESUMO

Tuberculosis (TB) a disease caused by Mycobacterium tuberculosis (Mtb) poses a significant threat to human life, and current BCG vaccinations only provide sporadic protection, therefore there is a need for developing efficient vaccines. Numerous immunoinformatic methods have been utilized previously, here for the first time a deep learning framework based on Deconvolutional Neural Networks (DCNN) and Bidirectional Long Short-Term Memory (DCNN-BiLSTM) was used to predict Mtb Multiepitope vaccine (MtbMEV) subunits against six Mtb H37Rv proteins. The trained model was used to design MEV within a few minutes against TB better than other machine learning models with 99.5% accuracy. The MEV has good antigenicity, and physiochemical properties, and is thermostable, soluble, and hydrophilic. The vaccine's BLAST search ruled out the possibility of autoimmune reactions. The secondary structure analysis revealed 87% coil, 10% beta, and 2% alpha helix, while the tertiary structure was highly upgraded after refinement. Molecular docking with TLR3 and TLR4 receptors showed good binding, indicating high immune reactions. Immune response simulation confirmed the generation of innate and adaptive responses. In-silico cloning revealed the vaccine is highly expressed in E. coli. The results can be further experimentally verified using various analyses to establish a candidate vaccine for future clinical trials.


Assuntos
Mycobacterium tuberculosis , Redes Neurais de Computação , Vacinas contra a Tuberculose , Vacinas contra a Tuberculose/imunologia , Mycobacterium tuberculosis/imunologia , Humanos , Simulação de Acoplamento Molecular , Desenvolvimento de Vacinas/métodos , Epitopos/imunologia , Tuberculose/prevenção & controle , Tuberculose/imunologia , Antígenos de Bactérias/imunologia , Antígenos de Bactérias/química
7.
PLoS One ; 19(4): e0294625, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38578767

RESUMO

The resilience of a country during the COVID-19 pandemic was determined based in whether it was holistically prepared and responsive. This resilience can only be identified through systematic data collection and analysis. Historical evidence-based response indicators have been proven to mitigate pandemics like COVID-19. However, most databases are outdated, requiring updating, derivation, and explicit interpretation to gain insight into the impact of COVID-19. Outdated databases do not show a country's true preparedness and response capacity, therefore, it undermines pandemic threat. This study uses up-to-date evidence-based pandemic indictors to run a cross-country comparative analysis of COVID-19 preparedness, response capacity, and healthcare resilience. PROMETHEE-a multicriteria decision making (MCDM) technique-is used to quantify the strengths (positive) and weaknesses (negative) of each country's COVID-19 responses, with full ranking (net) from best to least responsive. From 22 countries, South Korea obtained the highest net outranking value of 0.1945, indicating that it was the most resilient, while Mexico had the lowest (-0.1428). Although countries were underprepared, there was a robust response to the pandemic, especially in developing countries. This study demonstrates the performance and response capacity of 22 key countries to resist COVID-19, from which other countries can compare their statutory capacity ranking in order to learn/adopt the evidence-based responses of better performing countries to improve their resilience.


Assuntos
COVID-19 , Resiliência Psicológica , Humanos , COVID-19/epidemiologia , Pandemias , Coleta de Dados , Bases de Dados Factuais
8.
PLoS One ; 19(7): e0305728, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39046956

RESUMO

It is well-known that the Tseng algorithm and its modifications have been successfully employed in approximating zeros of the sum of monotone operators. In this study, we restored various thoracic diseases' computerized tomography (CT) images, which were degraded with a known blur function and additive noise, using a modified Tseng algorithm. The test images used in the study depict calcification of the Aorta, Subcutaneous Emphysema, Tortuous Aorta, Pneumomediastinum, and Pneumoperitoneum. Additionally, we employed well-known image restoration tools to enhance image quality and compared the quality of restored images with the originals. Finally, the study demonstrates the potential to advance monotone inclusion problem-solving, particularly in the field of medical image recovery.


Assuntos
Algoritmos , Doenças Torácicas , Tomografia Computadorizada por Raios X , Humanos , Tomografia Computadorizada por Raios X/métodos , Doenças Torácicas/diagnóstico por imagem
9.
Brain Sci ; 14(6)2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38928561

RESUMO

Disease prediction is greatly challenged by the scarcity of datasets and privacy concerns associated with real medical data. An approach that stands out to circumvent this hurdle is the use of synthetic data generated using Generative Adversarial Networks (GANs). GANs can increase data volume while generating synthetic datasets that have no direct link to personal information. This study pioneers the use of GANs to create synthetic datasets and datasets augmented using traditional augmentation techniques for our binary classification task. The primary aim of this research was to evaluate the performance of our novel Conditional Deep Convolutional Neural Network (C-DCNN) model in classifying brain tumors by leveraging these augmented and synthetic datasets. We utilized advanced GAN models, including Conditional Deep Convolutional Generative Adversarial Network (DCGAN), to produce synthetic data that retained essential characteristics of the original datasets while ensuring privacy protection. Our C-DCNN model was trained on both augmented and synthetic datasets, and its performance was benchmarked against state-of-the-art models such as ResNet50, VGG16, VGG19, and InceptionV3. The evaluation metrics demonstrated that our C-DCNN model achieved accuracy, precision, recall, and F1 scores of 99% on both synthetic and augmented images, outperforming the comparative models. The findings of this study highlight the potential of using GAN-generated synthetic data in enhancing the training of machine learning models for medical image classification, particularly in scenarios with limited data available. This approach not only improves model accuracy but also addresses privacy concerns, making it a viable solution for real-world clinical applications in disease prediction and diagnosis.

10.
Brain Commun ; 6(6): fcae372, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39494363

RESUMO

The scarcity of medical imaging datasets and privacy concerns pose significant challenges in artificial intelligence-based disease prediction. This poses major concerns to patient confidentiality as there are now tools capable of extracting patient information by merely analysing patient's imaging data. To address this, we propose the use of synthetic data generated by generative adversarial networks as a solution. Our study pioneers the utilisation of a novel Pix2Pix generative adversarial network model, specifically the 'image-to-image translation with conditional adversarial networks,' to generate synthetic datasets for brain tumour classification. We focus on classifying four tumour types: glioma, meningioma, pituitary and healthy. We introduce a novel conditional deep convolutional neural network architecture, developed from convolutional neural network architectures, to process the pre-processed generated synthetic datasets and the original datasets obtained from the Kaggle repository. Our evaluation metrics demonstrate the conditional deep convolutional neural network model's high performance with synthetic images, achieving an accuracy of 86%. Comparative analysis with state-of-the-art models such as Residual Network50, Visual Geometry Group 16, Visual Geometry Group 19 and InceptionV3 highlights the superior performance of our conditional deep convolutional neural network model in brain tumour detection, diagnosis and classification. Our findings underscore the efficacy of our novel Pix2Pix generative adversarial network augmentation technique in creating synthetic datasets for accurate brain tumour classification, offering a promising avenue for improved disease prediction and treatment planning.

11.
PLoS One ; 19(4): e0297476, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38635754

RESUMO

This paper mainly addressed the study of the transmission dynamics of infectious diseases and analysed the effect of two different types of viruses simultaneously that cause immunodeficiency in the host. The two infectious diseases that often spread in the populace are HIV and measles. The interaction between measles and HIV can cause severe illness and even fatal patient cases. The effects of the measles virus on the host with HIV infection are studied using a mathematical model and their dynamics. Analysing the dynamics of infectious diseases in communities requires the use of mathematical models. Decisions about public health policy are influenced by mathematical modeling, which sheds light on the efficacy of various control measures, immunization plans, and interventions. We build a mathematical model for disease spread through vertical and horizontal human population transmission, including six coupled nonlinear differential equations with logistic growth. The fundamental reproduction number is examined, which serves as a cutoff point for determining the degree to which a disease will persist or die. We look at the various disease equilibrium points and investigate the regional stability of the disease-free and endemic equilibrium points in the feasible region of the epidemic model. Concurrently, the global stability of the equilibrium points is investigated using the Lyapunov functional approach. Finally, the Runge-Kutta method is utilised for numerical simulation, and graphic illustrations are used to evaluate the impact of different factors on the spread of the illness. Critical factors that effect the dynamics of disease transmission and greatly affect the rate and range of the disease's spread in the population have been determined through a thorough analysis. These factors are crucial in determining the expansion of the disease.


Assuntos
Doenças Transmissíveis , Infecções por HIV , Sarampo , Humanos , Modelos Biológicos , Modelos Teóricos , Doenças Transmissíveis/epidemiologia , Sarampo/prevenção & controle
12.
Sci Rep ; 14(1): 11781, 2024 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-38783089

RESUMO

This study explored the application of machine learning in predicting post-treatment outcomes for chronic neck pain patients undergoing a multimodal program featuring cervical extension traction (CET). Pre-treatment demographic and clinical variables were used to develop predictive models capable of anticipating modifications in cervical lordotic angle (CLA), pain and disability of 570 patients treated between 2014 and 2020. Linear regression models used pre-treatment variables of age, body mass index, CLA, anterior head translation, disability index, pain score, treatment frequency, duration and compliance. These models used the sci-kit-learn machine learning library within Python for implementing linear regression algorithms. The linear regression models demonstrated high precision and accuracy, and effectively explained 30-55% of the variability in post-treatment outcomes, the highest for the CLA. This pioneering study integrates machine learning into spinal rehabilitation. The developed models offer valuable information to customize interventions, set realistic expectations, and optimize treatment strategies based on individual patient characteristics as treated conservatively with rehabilitation programs using CET as part of multimodal care.


Assuntos
Dor Crônica , Aprendizado de Máquina , Cervicalgia , Tração , Humanos , Cervicalgia/terapia , Feminino , Masculino , Pessoa de Meia-Idade , Dor Crônica/terapia , Adulto , Tração/métodos , Resultado do Tratamento , Vértebras Cervicais
13.
Sci Rep ; 14(1): 10180, 2024 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-38702384

RESUMO

In this manuscript, a mathematical model known as the Heimburg model is investigated analytically to get the soliton solutions. Both biomembranes and nerves can be studied using this model. The cell membrane's lipid bilayer is regarded by the model as a substance that experiences phase transitions. It implies that the membrane responds to electrical disruptions in a nonlinear way. The importance of ionic conductance in nerve impulse propagation is shown by Heimburg's model. The dynamics of the electromechanical pulse in a nerve are analytically investigated using the Hirota Bilinear method. The various types of solitons are investigates, such as homoclinic breather waves, interaction via double exponents, lump waves, multi-wave, mixed type solutions, and periodic cross kink solutions. The electromechanical pulse's ensuing three-dimensional and contour shapes offer crucial insight into how nerves function and may one day be used in medicine and the biological sciences. Our grasp of soliton dynamics is improved by this research, which also opens up new directions for biomedical investigation and medical developments. A few 3D and contour profiles have also been created for new solutions, and interaction behaviors have also been shown.


Assuntos
Membrana Celular , Membrana Celular/fisiologia , Bicamadas Lipídicas/química , Bicamadas Lipídicas/metabolismo , Humanos , Modelos Neurológicos , Modelos Biológicos , Modelos Teóricos
14.
Diagnostics (Basel) ; 14(9)2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38732335

RESUMO

BACKGROUND: In planning radiotherapy treatments, computed tomography (CT) has become a crucial tool. CT scans involve exposure to ionizing radiation, which can increase the risk of cancer and other adverse health effects in patients. Ionizing radiation doses for medical exposure must be kept "As Low As Reasonably Achievable". Very few articles on guidelines for radiotherapy-computed tomography scans are available. This paper reviews the current literature on radiation dose optimization based on the effective dose and diagnostic reference level (DRL) for head, neck, and pelvic CT procedures used in radiation therapy planning. This paper explores the strategies used to optimize radiation doses, and high-quality images for diagnosis and treatment planning. METHODS: A cross-sectional study was conducted on 300 patients with head, neck, and pelvic region cancer in our institution. The DRL, effective dose, volumetric CT dose index (CTDIvol), and dose-length product (DLP) for the present and optimized protocol were calculated. DRLs were proposed for the DLP using the 75th percentile of the distribution. The DLP is a measure of the radiation dose received by a patient during a CT scan and is calculated by multiplying the CT dose index (CTDI) by the scan length. To calculate a DRL from a DLP, a large dataset of DLP values obtained from a specific imaging procedure must be collected and can be used to determine the median or 75th-percentile DLP value for each imaging procedure. RESULTS: Significant variations were found in the DLP, CTDIvol, and effective dose when we compared both the standard protocol and the optimized protocol. Also, the optimized protocol was compared with other diagnostic and radiotherapy CT scan studies conducted by other centers. As a result, we found that our institution's DRL was significantly low. The optimized dose protocol showed a reduction in the CTDIvol (70% and 63%), DLP (60% and 61%), and effective dose (67% and 62%) for both head, neck, and pelvic scans. CONCLUSIONS: Optimized protocol DRLs were proposed for comparison purposes.

15.
J Med Imaging Radiat Sci ; 55(2): 272-280, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38594085

RESUMO

INTRODUCTION: Radiologists have extensively employed the interpretation of chest X-rays (CXR) to identify visual markers indicative of COVID-19 infection, offering an alternative approach for the screening of infected individuals. This research article presents CovMediScanX, a deep learning-based framework designed for a rapid and automated diagnosis of COVID-19 from CXR scan images. METHODS: The proposed approach encompasses gathering and preprocessing CXR image datasets, training deep learning-based custom-made Convolutional Neural Network (CNN), pre-trained and hybrid transfer learning models, identifying the highest-performing model based on key evaluation metrics, and embedding this model into a web interface called CovMediScanX, designed for radiologists to detect the COVID-19 status in new CXR images. RESULTS: The custom-made CNN model obtained a remarkable testing accuracy of 94.32% outperforming other models. CovMediScanX, employing the custom-made CNN underwent evaluation with an independent dataset also. The images in the independent dataset are sourced from a scanning machine that is entirely different from those used for the training dataset, highlighting a clear distinction of datasets in their origins. The evaluation outcome highlighted the framework's capability to accurately detect COVID-19 cases, showcasing encouraging results with a precision of 73% and a recall of 84% for positive cases. However, the model requires further enhancement, particularly in improving its detection of normal cases, as evidenced by lower precision and recall rates. CONCLUSION: The research proposes CovMediScanX framework that demonstrates promising potential in automatically identifying COVID-19 cases from CXR images. While the model's overall performance on independent data needs improvement, it is evident that addressing bias through the inclusion of diverse data sources during training could further enhance accuracy and reliability.


Assuntos
COVID-19 , Aprendizado Profundo , Radiografia Torácica , Humanos , COVID-19/diagnóstico por imagem , Radiografia Torácica/métodos , SARS-CoV-2 , Redes Neurais de Computação
16.
Braz J Biol ; 84: e284361, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39140507

RESUMO

Coronary Artery Disease (CAD) is a global health concern, with diagnostic modalities and risk factors that exhibit regional variations. This study, conducted at the Islamabad Diagnostic Center, Pakistan, aimed to provide a comprehensive assessment of CAD prevalence, severity, and associated risk factors, while also evaluating the diagnostic accuracy of Computed Tomography Coronary Test (CTT) and Exercise Treadmill Test (ETT) in a cohort of 2909 patients. Among the patients assessed via CT Coronary scans, CAD was universally observed, presenting with varying degrees of severity. Our findings indicated that 24.5% of patients had mild CAD, 28.6% exhibited mild to moderate CAD, 16.3% were diagnosed with moderate CAD, 18.4% demonstrated moderate to severe CAD, and 20.4% displayed severe CAD. This spectrum underscores the diverse nature of CAD within the study population. In addition to CTT, we conducted a detailed evaluation of ETT results in 49 patients. These results revealed that 55.1% of patients tested positive for ischemia during the exercise test, emphasizing the prevalence of cardiac stress and underlying CAD. Conversely, 32.7% of patients exhibited negative ETT results, indicating favorable cardiac tolerance during physical activity. A subset of patients yielded non-diagnostic or inconclusive results, necessitating further clinical assessment. Disease history analysis showed a dichotomy within the cohort, with 20.4% having a known medical history and 79.6% possessing an unknown disease history, highlighting the importance of comprehensive medical records in clinical practice. Hypertension, a critical cardiovascular risk factor, was identified in 87.8% of patients, underscoring its significance. Smoking history displayed notable variation, with 69.4% categorized as smokers, 14.3% as ex-smokers, and 10.2% as non-smokers. Lipid profile analysis indicated that 69.4% of patients had abnormal lipid levels. To assess the diagnostic accuracy of CTT and ETT, we calculated Positive Predictive Values (PPV) and Negative Predictive Values (NPV). CTT exhibited a PPV of approximately 5.99% and an NPV of approximately 4.40%, whereas ETT displayed a higher PPV of around 26.44% and a substantially higher NPV of about 49.24%. This study offers valuable insights into CAD prevalence, severity, and associated risk factors in a Pakistani cohort, emphasizing the importance of holistic risk assessment and tailored interventions in clinical practice. Our findings also highlight the diagnostic utility of ETT in CAD assessment.


Assuntos
Doença da Artéria Coronariana , Teste de Esforço , Humanos , Teste de Esforço/métodos , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/diagnóstico , Paquistão/epidemiologia , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , Fatores de Risco , Idoso , Prevalência , Índice de Gravidade de Doença , Tomografia Computadorizada por Raios X , Angiografia Coronária
17.
Sci Total Environ ; 858(Pt 2): 159697, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36334664

RESUMO

The growing increase in groundwater (GW) salinization in the coastal aquifers has reached an alarming socio-economic menace in Saudi Arabia and various places globally due to several natural and anthropogenic activities. Hence, evaluating the GW salinization is paramount to safeguarding the water resources planning and management. This study presents three different scenarios viz.: real field investigation, experimental laboratory analysis (using ion chromatography (IC) and inductively coupled plasma mass spectrometry (ICP-MS), etc.), and artificial intelligence (AI) based metaheuristic optimization (MO) algorithms in Saudi Arabia. The main purpose of this study is to validate the obtained experimental-based analysis using hybrid MO techniques comprising of adaptive neuro-fuzzy inference system (ANFIS) hybridized with genetic algorithm (GA), particle swarm optimization (PSO), and biogeography-based optimization (BBO) for identification of GW salinization in the coastal region of eastern Saudi Arabia. Additionally, ArcGIS 10.3 software generates the prediction map based on ANFIS-GA, ANFIS-PSO, and ANFIS-BBO. Feature selection was assessed using the PSO algorithm, and four indices evaluated the estimated models, namely, root mean square error (RMSE), mean absolute error (MAE), mean absolute percentage error (MAPE), and standard deviation (SD). The simulated results are based on three variable input combinations, which showed that the ANFIS-PSO (MAE = 0.00439) algorithm had the highest accuracy (99 %), followed by the ANFIS-GA (MAE = 0.00767) and ANFIS-BBO (MAE = 0.0132) algorithms. Besides, Ca2+, Na+, Mg2+, and Cl- were the most influential parameters. The accuracy also demonstrated the potential reliability of MO algorithms based on spatial distribution mapping. The employed approach proved to be merit and reliable tool for water resources decision-makers in the coastal aquifer of Saudi Arabia. This approach is believed to improve water scarcity as one of the essential targets for Goal 6 of Sustainable Development Vision 2030 and the Kingdom in general.


Assuntos
Lógica Fuzzy , Água Subterrânea , Inteligência Artificial , Heurística , Arábia Saudita , Reprodutibilidade dos Testes , Algoritmos
18.
Sci Rep ; 13(1): 10972, 2023 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-37414803

RESUMO

Modern smart coating systems are increasingly exploiting functional materials which combine multiple features including rheology, electromagnetic properties and nanotechnological capabilities and provide a range of advantages in diverse operations including medical, energy and transport designs (aerospace, marine, automotive). The simulation of the industrial synthesis of these multi-faceted coatings (including stagnation flow deposition processes) requires advanced mathematical models which can address multiple effects simultaneously. Inspired by these requests, this study investigates the interconnected magnetohydrodynamic non-Newtonian movement and thermal transfer in the Hiemenz plane's stagnation flow. Additionally, it explores the application of a transverse static magnetic field to a ternary hybrid nanofluid coating through theoretical and numerical analysis. The base fluid (polymeric) considered is engine-oil (EO) doped with graphene [Formula: see text], gold [Formula: see text] and Cobalt oxide [Formula: see text] nanoparticles. The model includes the integration of non-linear radiation, heat source, convective wall heating, and magnetic induction effects. For non-Newtonian characteristics, the Williamson model is utilized, while the Rosseland diffusion flux model is used for radiative transfer. Additionally, a non-Fourier Cattaneo-Christov heat flux model is utilized to include thermal relaxation effects. The governing partial differential conservation equations for mass, momentum, energy and magnetic induction are rendered into a system of coupled self-similar and non-linear ordinary differential equations (ODEs) with boundary restrictions using appropriate scaling transformations. The dimensionless boundary value problem that arises is solved using the bvp4c built-in function in MATLAB software, which employs the fourth-order Runge-Kutta (RK-4) method. An extensive examination is conducted to evaluate the impact of essential control parameters on the velocity [Formula: see text], induced magnetic field stream function gradient [Formula: see text] and temperature [Formula: see text] is conducted. The relative performance of ternary, hybrid binary and unitary nanofluids for all transport characteristics is evaluated. The inclusion of verification of the MATLAB solutions with prior studies is incorporated. Fluid velocity is observed to be minimized for the ternary [Formula: see text]-[Formula: see text]-[Formula: see text] nanofluid whereas the velocity is maximized for the unitary cobalt oxide [Formula: see text] nanofluid with increasing magnetic parameter ([Formula: see text] Temperatures are elevated with increment in thermal radiation parameter (Rd). Streamlines are strongly modified in local regions with greater viscoelasticity i.e. higher Weissenberg number [Formula: see text]. Dimensionless skin friction is significantly greater for the ternary hybrid [Formula: see text]-[Formula: see text]-[Formula: see text] nanofluid compared with binary hybrid or unitary nanofluid cases.


Assuntos
Temperatura Alta , Óxidos , Fenômenos Físicos , Condutividade Elétrica
19.
Sci Rep ; 13(1): 11643, 2023 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-37468495

RESUMO

Recently, the International Energy Agency (IEA) released a comprehensive roadmap for the global energy sector to achieve net-zero emission by 2050. Considering the sizeable share of (Sub-Sahara) Africa in the global population, the attainment of global energy sector net-zero emission is practically impossible without a commitment from African countries. Therefore, it is important to study and analyze feasible/sustainable ways to solve the energy/electricity poverty in Africa. In this paper, the energy poverty in Africa and the high renewable energy (RE) potential are reviewed. Beyond this, the generation of electricity from the abundant RE potential in this region is analyzed in hourly timestep. This study is novel as it proposes a Sub-Sahara Africa (SSA) central grid as one of the fastest/feasible solutions to the energy poverty problem in this region. The integration of a sizeable share of electric vehicles with the proposed central grid is also analyzed. This study aims to determine the RE electricity generation capacities, economic costs, and supply strategies required to balance the projected future electricity demand in SSA. The analysis presented in this study is done considering 2030 and 2040 as the targeted years of implementation. EnergyPLAN simulation program is used to simulate/analyze the generation of electricity for the central grid. The review of the energy poverty in SSA showed that the electricity access of all the countries in this region is less than 100%. The analysis of the proposed central RE grid system is a viable and sustainable option, however, it requires strategic financial planning for its implementation. The cheapest investment cost from all the case scenarios in this study is $298 billion. Considering the use of a single RE technology, wind power systems implementation by 2030 and 2040 are the most feasible options as they have the least economic costs. Overall, the integration of the existing/fossil-fueled power systems with RE technologies for the proposed central grid will be the cheapest/easiest pathway as it requires the least economic costs. While this does not require the integration of storage systems, it will help the SSA countries reduce their electricity sector carbon emission by 56.6% and 61.8% by 2030 and 2040 respectively.

20.
Heliyon ; 9(10): e20196, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37780778

RESUMO

In this work, tank drainage phenomena for in-compressible and isothermal fluid having unsteady fluid flow for third order fluid is studied. Analytical solution of the proposed problem is obtained using perturbation method subject to proper boundary conditions. No-slip condition is used because of fluid will have zero velocity relative to a solid boundary. Object of this work is to find out the velocity profile, flow rate, time required to empty a tank (time efflux) and mathematical relation of time and depth of the tank. Influence of different parameter over velocity profile, effect of radius of the tank over depth, effect of radius of piper over flow rate and effect of depth over flow rate are examined graphically using mathematica. Velocity profile of this model is compared with newtonian fluid's while assuming epsilon as a zero using graph and table from which it is clear that third order fluid posses greater velocity then Newtonian fluid.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA