Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 256
Filtrar
1.
Skin Res Technol ; 30(9): e70040, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39221858

RESUMO

BACKGROUND: Skin cancer is one of the highly occurring diseases in human life. Early detection and treatment are the prime and necessary points to reduce the malignancy of infections. Deep learning techniques are supplementary tools to assist clinical experts in detecting and localizing skin lesions. Vision transformers (ViT) based on image segmentation classification using multiple classes provide fairly accurate detection and are gaining more popularity due to legitimate multiclass prediction capabilities. MATERIALS AND METHODS: In this research, we propose a new ViT Gradient-Weighted Class Activation Mapping (GradCAM) based architecture named ViT-GradCAM for detecting and classifying skin lesions by spreading ratio on the lesion's surface area. The proposed system is trained and validated using a HAM 10000 dataset by studying seven skin lesions. The database comprises 10 015 dermatoscopic images of varied sizes. The data preprocessing and data augmentation techniques are applied to overcome the class imbalance issues and improve the model's performance. RESULT: The proposed algorithm is based on ViT models that classify the dermatoscopic images into seven classes with an accuracy of 97.28%, precision of 98.51, recall of 95.2%, and an F1 score of 94.6, respectively. The proposed ViT-GradCAM obtains better and more accurate detection and classification than other state-of-the-art deep learning-based skin lesion detection models. The architecture of ViT-GradCAM is extensively visualized to highlight the actual pixels in essential regions associated with skin-specific pathologies. CONCLUSION: This research proposes an alternate solution to overcome the challenges of detecting and classifying skin lesions using ViTs and GradCAM, which play a significant role in detecting and classifying skin lesions accurately rather than relying solely on deep learning models.


Assuntos
Algoritmos , Aprendizado Profundo , Dermoscopia , Neoplasias Cutâneas , Humanos , Dermoscopia/métodos , Neoplasias Cutâneas/diagnóstico por imagem , Neoplasias Cutâneas/classificação , Neoplasias Cutâneas/patologia , Interpretação de Imagem Assistida por Computador/métodos , Bases de Dados Factuais , Pele/diagnóstico por imagem , Pele/patologia
2.
Appl Radiat Isot ; 214: 111481, 2024 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-39260315

RESUMO

In diagnostic radiology, the air kerma is an essential parameter. Radiologists consider the air kerma, when calculating organ doses and dangers to patients. The intensity of the radiation beam is represented by the air kerma, which is the value of energy wasted by a photon as it travels through air. Because of the heel effect in X-ray sources, air kerma varies throughout the field of medical imaging systems. One possible contributor to this discrepancy is the X-ray tube's voltage. In this study, an approach has been proposed for predicting the air kerma anywhere inside the field of X-ray beams utilized in medical diagnostic imaging systems. As a first step, a diagnostic imaging system was modelled using the Monte Carlo N-Particle platform. We used a tungsten target and aluminum and beryllium filters of varying thicknesses to recreate the X-ray tube. The air kerma has been measured in different parts of the conical X-ray beam that is working at 30, 50, 70, 90, 110, 130, and 150 kV. This gives enough data for training neural networks. The voltage of the X-ray tube, filter type, filter thickness, and the coordinates of each point used to calculate the air kerma were all inputs to the MLP neural network. The MLP architecture, known for its significant advancements in research and expanding applications, was trained to predict the quantity of air kerma as its output. Specifically, by considering X-ray tube filters of varying thicknesses, the trained MLP model demonstrated its capability to accurately predict the air kerma at every point within the X-ray field for a range of X-ray tube voltages typically used in medical diagnostic radiography (30-150 kV).

3.
Environ Monit Assess ; 196(10): 964, 2024 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-39304543

RESUMO

Uncontrolled human activity and nature are causing the deterioration of Saint Martin Island, Bangladesh's only tropical island, necessitating sustainable land use strategies and ecological practices. Therefore, the present study measures the land use/cover transition from 1974 to 2021, predicts 2032 and 2042, and constructs the spatiotemporal features of the Landscape Ecological Risk Index based on land use changes. The study utilized Maximum Likelihood Classification (MLC) on Landsat images from 1974, 1988, 2001, 2013, and Sentinel 2B in 2021, achieving ≥ 80% accuracy. The MLP-MC approach was also used to predict 2032 and 2042 LULC change patterns. The eco-risk index was developed using landscape disturbance and vulnerability indices, Bayesian Kriging interpolation, and spatial autocorrelations to indicate spatial clustering. The research found that settlements increased from 2.06 to 28.62 ha between 1974 and 2021 and would cover 41.22 ha in 2042, causing considerable losses in agricultural areas, waterbodies, sand, coral reefs, and vegetation. The area under study showed a more uniform and homogenous environment as Shannon's diversity and evenness scores decreased. The ecological risk of Saint Martin Island increased from 4.31 to 31.05 ha between 1974 and 2042 due to natural and human factors like erosion, tidal bores, population growth, coral mining, habitat destruction, and intensive agricultural practices and tourism, primarily in Nazrul Para, Galachipa, and Western Dakhin Para. The findings will benefit St. Martin Island stakeholders and policymakers by providing insights into current and potential landscape changes and land eco-management.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Monitoramento Ambiental , Sistemas de Informação Geográfica , Ilhas , Tecnologia de Sensoriamento Remoto , Bangladesh , Monitoramento Ambiental/métodos , Medição de Risco/métodos , Humanos , Teorema de Bayes
4.
Talanta ; 280: 126793, 2024 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-39222596

RESUMO

Dry matter content (DMC), firmness and soluble solid content (SSC) are important indicators for assessing the quality attributes and determining the maturity of kiwifruit. However, traditional measurement methods are time-consuming, labor-intensive, and destructive to the kiwifruit, leading to resource wastage. In order to solve this problem, this study has tracked the flowering, fruiting, maturing and collecting processes of Ya'an red-heart kiwifruit, and has proposed a non-destructive method for kiwifruit quality attribute assessment and maturity identification that combines fluorescence hyperspectral imaging (FHSI) technology and chemometrics. Specifically, first of all, three different spectral data preprocessing methods were adopted, and PLSR was used to evaluate the quality attributes (DMC, firmness, and SSC) of kiwifruit. Next, the differences in accuracy of different models in discriminating kiwifruit maturity were compared, and an ensemble learning model based on LightGBM and GBDT models was constructed. The results indicate that the ensemble learning model outperforms single machine learning models. In addition, the application effects of the 'Convolutional Neural Network'-'Multilayer Perceptron' (CNN-MLP) model under different optimization algorithms were compared. To improve the robustness of the model, an improved whale optimization algorithm (IWOA) was introduced by modifying the acceleration factor. Overall, the IWOA-CNN-MLP model performs the best in discriminating the maturity of kiwifruit, with Accuracytest of 0.916 and Loss of 0.23. In addition, compared with the basic model, the accuracy of the integrated learning model SG-MSC-SEL was improved by about 12%-20 %. The research findings will provide new perspectives for the evaluation of kiwifruit quality and maturity discrimination using FHSI and chemometric methods, thereby promoting further research and applications in this field.


Assuntos
Actinidia , Frutas , Imageamento Hiperespectral , Actinidia/química , Actinidia/crescimento & desenvolvimento , Imageamento Hiperespectral/métodos , Frutas/química , Frutas/crescimento & desenvolvimento , Quimiometria , Redes Neurais de Computação , Qualidade dos Alimentos , Fluorescência , Controle de Qualidade
5.
PeerJ Comput Sci ; 10: e2208, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39145220

RESUMO

Many advanced super-resolution reconstruction methods have been proposed recently, but they often require high computational and memory resources, making them incompatible with low-power devices in reality. To address this problem, we propose a simple yet efficient super-resolution reconstruction method using waveform representation and multi-layer perceptron (MLP) for image processing. Firstly, we partition the original image and its down-sampled version into multiple patches and introduce WaveBlock to process these patches. WaveBlock represents patches as waveform functions with amplitude and phase and extracts representative feature representations by dynamically adjusting phase terms between tokens and fixed weights. Next, we fuse the extracted features through a feature fusion block and finally reconstruct the image using sub-pixel convolution. Extensive experimental results demonstrate that SRWave-MLP performs excellently in both quantitative evaluation metrics and visual quality while having significantly fewer parameters than state-of-the-art efficient super-resolution methods.

6.
Psychiatry Res Neuroimaging ; 343: 111858, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39106532

RESUMO

Autism is a neurodevelopmental disorder that manifests in individuals during childhood and has enduring consequences for their social interactions and communication. The prediction of Autism Spectrum Disorder (ASD) in individuals based on the differences in brain networks and activities have been studied extensively in the recent past, however, with lower accuracies. Therefore in this research, identification at the early stage through computer-aided algorithms to differentiate between ASD and TD patients is proposed. In order to identify features, a Multi-Layer Perceptron (MLP) model is developed which utilizes logistic regression on characteristics extracted from connectivity matrices of subjects derived from fMRI images. The features that significantly contribute to the classification of individuals as having Autism Spectrum Disorder (ASD) or typically developing (TD) are identified by the logistic regression model. To enhance emphasis on essential attributes, an AND operation is integrated. This involves selecting features demonstrating statistical significance across diverse logistic regression analyses conducted on various random distributions. The iterative approach contributes to a comprehensive understanding of relevant features for accurate classification. By implementing this methodology, the estimation of feature importance became more dependable, and the potential for overfitting is moderated through the evaluation of model performance on various subsets of data. It is observed from the experimentation that the highly correlated Left Lateral Occipital Cortex and Right Lateral Occipital Cortex ROIs are only found in ASD. Also, it is noticed that the highly correlated Left Cerebellum Tonsil and Right Cerebellum Tonsil are only found in TD participants. Among the MLP classifier, a recall of 82.61 % is achieved followed by Logistic Regression with an accuracy of 72.46 %. MLP also stands out with a commendable accuracy of 83.57 % and AUC of 0.978.


Assuntos
Transtorno do Espectro Autista , Imageamento por Ressonância Magnética , Humanos , Transtorno do Espectro Autista/diagnóstico por imagem , Transtorno do Espectro Autista/fisiopatologia , Imageamento por Ressonância Magnética/métodos , Masculino , Feminino , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Adolescente , Criança , Adulto , Adulto Jovem , Algoritmos
7.
Plants (Basel) ; 13(16)2024 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-39204736

RESUMO

Accurate segmentation of the stem of pumpkin seedlings has a great influence on the modernization of pumpkin cultivation, and can provide detailed data support for the growth of pumpkin plants. We collected and constructed a pumpkin seedling point cloud dataset for the first time. Potting soil and wall background in point cloud data often interfere with the accuracy of partial cutting of pumpkin seedling stems. The stem shape of pumpkin seedlings varies due to other environmental factors during the growing stage. The stem of the pumpkin seedling is closely connected with the potting soil and leaves, and the boundary of the stem is easily blurred. These problems bring challenges to the accurate segmentation of pumpkin seedling point cloud stems. In this paper, an accurate segmentation algorithm for pumpkin seedling point cloud stems based on CPHNet is proposed. First, a channel residual attention multilayer perceptron (CRA-MLP) module is proposed, which suppresses background interference such as soil. Second, a position-enhanced self-attention (PESA) mechanism is proposed, enabling the model to adapt to diverse morphologies of pumpkin seedling point cloud data stems. Finally, a hybrid loss function of cross entropy loss and dice loss (HCE-Dice Loss) is proposed to address the issue of fuzzy stem boundaries. The experimental results show that CPHNet achieves a 90.4% average cross-to-merge ratio (mIoU), 93.1% average accuracy (mP), 95.6% average recall rate (mR), 94.4% F1 score (mF1) and 0.03 plants/second (speed) on the self-built dataset. Compared with other popular segmentation models, this model is more accurate and stable for cutting the stem part of the pumpkin seedling point cloud.

8.
Intell Syst Appl ; 222024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-39206419

RESUMO

In this study, we present a novel graph-based methodology for an accurate classification of cardiac arrhythmia diseases using a single-lead electrocardiogram (ECG). The proposed approach employs the visibility graph technique to generate graphs from time signals. Subsequently, informative features are extracted from each graph and then fed into classifiers to match the input ECG signal with the appropriate target arrhythmia class. The six target classes in this study are normal (N), left bundle branch block (LBBB), right bundle branch block (RBBB), premature ventricular contraction (PVC), atrial premature contraction (A), and fusion (F) beats. Three classification models were explored, including graph convolutional neural network (GCN), multi-layer perceptron (MLP), and random forest (RF). ECG recordings from the MIT-BIH arrhythmia database were utilized to train and evaluate these classifiers. The results indicate that the multi-layer perceptron model attains the highest performance, showcasing an average accuracy of 99.02%. Following closely, the random forest achieves a strong performance as well, with an accuracy of 98.94% while providing critical intuitions.

9.
Diagnostics (Basel) ; 14(16)2024 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-39202259

RESUMO

Background: Dengue hemorrhagic fever (DHF) is the most prevalent and fastest-growing vector-borne disease globally, with symptoms ranging from mild to severe and, in some cases, fatal. Quang Nam province in Vietnam can serve as a model for dengue epidemiological study, as it is an endemic region for DHF with a tropical climate, which significantly constrains the health system. However, there are very few epidemiological and microbiological reports on Dengue virus (DENV) serotypes in this region due to the limited availability of advanced surveillance infrastructure. Aims of the study: This study aims to (1) assess the PCR positivity rates among hospitalized patients with clinical Dengue presentation; (2) identify the circulating DENV serotypes; and (3) assess the impact of secondary DENV infections on outbreak severity by detecting the presence of DENV-specific IgG antibodies in the plasma of DENV-infected patients. Materials and methods: Blood samples from patients clinically diagnosed with DHF and admitted to Quang Nam General Hospital (2020-2022) were analyzed. RNA extraction was performed using the NKDNA/RNAprep MAGBEAD kit, followed by Multiplex Reverse Transcription real-time Polymerase Chain Reaction (MLP RT-rPCR) for DENV detection and serotype identification. Positive samples were further tested for DENV-specific IgG antibodies using an enzyme-linked immunosorbent assay (ELISA). Results: The PCR positivity rate among hospitalized patients was approximately 68% throughout the study period. A significant shift in DENV serotypes was observed, with DENV-2 initially dominant and later giving way to DENV-1. IgG was detected in nearly half of the MPL RT-rPCR-positive samples, indicating secondary DENV infections. Conclusions: Our study highlights persistent dengue prevalence and dynamic shifts in DENV serotypes in Quang Nam province, emphasizing the need for improved diagnostic strategies and timely sample collection. The significant serotype shifts and the presence of IgG in hospitalized patients suggest potential severe outcomes from recurrent DENV infections, possibly linked to antibody-dependent enhancement (ADE) effect, underscoring the importance of advanced surveillance, vector control, vaccination campaigns, and public education to predict and prevent future DHF epidemics.

10.
Front Psychol ; 15: 1425471, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39144589

RESUMO

Objective: This study aims to precisely model the nonlinear relationship between university students' literature reading preferences (LRP) and their levels of anxiety and depression using a multilayer perceptron (MLP) to identify reading-related risk factors affecting anxiety and depression among university students. Methods: In this cross-sectional study, an internet-based questionnaire was conducted among 2,092 undergraduate students (aged 18-22, 62.7% female, from seven provinces in China). Participants completed a customized questionnaire on their LRP, followed by standardized assessments of anxiety and depression using the Generalized Anxiety Disorder 7-item Scale and the Beck Depression Inventory, respectively. An MLP with residual connections was employed to establish the nonlinear relationship between LRP and anxiety and depression. Results: The MLP model achieved an average accuracy of 86.8% for predicting non-anxious individuals and 81.4% for anxious individuals. In the case of depression, the model's accuracy was 90.1% for non-depressed individuals and 84.1% for those with depression. SHAP value analysis identified "Tense/Suspenseful-Emotional Tone," "War and Peace-Thematic Content," and "Infrequent Reading-Reading Habits" as the top contributors to anxiety prediction accuracy. Similarly, "Sad-Emotional Tone Preference," "Emotional Depictions-Thematic Content," and "Thought-Provoking-Emotional Tone" were the primary contributors to depression prediction accuracy. Conclusion: The MLP accurately models the nonlinear relationship between LRP and mental health in university students, indicating the significance of specific reading preferences as risk factors. The study underscores the importance of literature emotional tone and themes in mental health. LRP should be integrated into psychological assessments to help prevent anxiety and depression among university students.

11.
Sensors (Basel) ; 24(14)2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39066004

RESUMO

The carbon content as received (Car) of coal is essential for the emission factor method in IPCC methodology. The traditional carbon measurement mechanism relies on detection equipment, resulting in significant detection costs. To reduce detection costs and provide precise predictions of Cars even in the absence of measurements, this paper proposes a neural network combining MLP with an attention mechanism (MSA-Net). In this model, the Attention Module is proposed to extract important and potential features. The Skip-Connections are utilized for feature reuse. The Huber loss is used to reduce the error between predicted Car values and actual values. The experimental results show that when the input includes eight measured parameters, the MAPE of MSA-Net is only 0.83%, which is better than the state-of-the-art Gaussian Process Regression (GPR) method. MSA-Net exhibits better predictive performance compared to MLP, RNN, LSTM, and Transformer. Moreover, this article provides two measurement solutions for thermal power enterprises to reduce detection costs.

12.
Phys Eng Sci Med ; 47(3): 1245-1258, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38900229

RESUMO

The ECG is a crucial tool in the medical field for recording the heartbeat signal over time, aiding in the identification of various cardiac diseases. Commonly, the interpretation of ECGs necessitates specialized knowledge. However, this paper explores the application of machine learning algorithms and deep learning algorithm to autonomously identify cardiac diseases in diabetic patients in the absence of expert intervention. Two models are introduced in this study: The MLP model effectively distinguishes between individuals with heart diseases and those without, achieving a high level of accuracy. Subsequently, the deep CNN model further refines the identification of specific cardiac conditions. The PTB-Diagnostic ECG dataset commonly used in the field of biomedical signal processing and machine learning, particularly for tasks related to electrocardiogram (ECG) analysis. a widely recognized dataset in the field, is employed for training, testing, and validation of both the MLP and CNN models. This dataset comprises a diverse range of ECG recordings, providing a comprehensive representation of cardiac conditions. The proposed models feature two hidden layers with weights and biases in the MLP, and a three-layer CNN, facilitating the mapping of ECG data to different disease classes. The experimental results demonstrate that the MLP and deep CNN based models attain accuracy levels of up to 90.0% and 98.35%, and sensitivity 97.8%, 95.77%, specificity 88.9%, 96.3% F1-Score 93.13%, 95.84% respectively. These outcomes underscore the efficacy of deep learning approaches in automating the diagnosis of cardiac diseases through ECG analysis, showcasing the potential for accurate and efficient healthcare solutions.


Assuntos
Diabetes Mellitus , Eletrocardiografia , Redes Neurais de Computação , Humanos , Aprendizado Profundo , Cardiopatias/diagnóstico por imagem , Algoritmos , Processamento de Sinais Assistido por Computador
13.
Sensors (Basel) ; 24(11)2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38894186

RESUMO

Smart wearable sensors are increasingly integrated into everyday life, interfacing with the human body to enable real-time monitoring of biological signals. This study focuses on creating high-sensitivity capacitive-type sensors by impregnating polyester-based 3D spacer fabric with a Carbon Nanotube (CNT) dispersion. The unique properties of conductive particles lead to nonlinear variations in the dielectric constant when pressure is applied, consequently affecting the gauge factor. The results reveal that while the fabric without CNT particles had a gauge factor of 1.967, the inclusion of 0.04 wt% CNT increased it significantly to 5.210. As sensor sensitivity requirements vary according to the application, identifying the necessary CNT wt% is crucial. Artificial intelligence, particularly the Multilayer Perception (MLP) model, enables nonlinear regression analysis for this purpose. The MLP model created and validated in this research showed a high correlation coefficient of 0.99564 between the model predictions and actual target values, indicating its effectiveness and reliability.

14.
J Imaging Inform Med ; 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38839675

RESUMO

Skin cancer is one of the most frequently occurring cancers worldwide, and early detection is crucial for effective treatment. Dermatologists often face challenges such as heavy data demands, potential human errors, and strict time limits, which can negatively affect diagnostic outcomes. Deep learning-based diagnostic systems offer quick, accurate testing and enhanced research capabilities, providing significant support to dermatologists. In this study, we enhanced the Swin Transformer architecture by implementing the hybrid shifted window-based multi-head self-attention (HSW-MSA) in place of the conventional shifted window-based multi-head self-attention (SW-MSA). This adjustment enables the model to more efficiently process areas of skin cancer overlap, capture finer details, and manage long-range dependencies, while maintaining memory usage and computational efficiency during training. Additionally, the study replaces the standard multi-layer perceptron (MLP) in the Swin Transformer with a SwiGLU-based MLP, an upgraded version of the gated linear unit (GLU) module, to achieve higher accuracy, faster training speeds, and better parameter efficiency. The modified Swin model-base was evaluated using the publicly accessible ISIC 2019 skin dataset with eight classes and was compared against popular convolutional neural networks (CNNs) and cutting-edge vision transformer (ViT) models. In an exhaustive assessment on the unseen test dataset, the proposed Swin-Base model demonstrated exceptional performance, achieving an accuracy of 89.36%, a recall of 85.13%, a precision of 88.22%, and an F1-score of 86.65%, surpassing all previously reported research and deep learning models documented in the literature.

15.
Biomimetics (Basel) ; 9(6)2024 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-38921244

RESUMO

The need for non-interactive human recognition systems to ensure safe isolation between users and biometric equipment has been exposed by the COVID-19 pandemic. This study introduces a novel Multi-Scaled Deep Convolutional Structure for Punctilious Human Gait Authentication (MSDCS-PHGA). The proposed MSDCS-PHGA involves segmenting, preprocessing, and resizing silhouette images into three scales. Gait features are extracted from these multi-scale images using custom convolutional layers and fused to form an integrated feature set. This multi-scaled deep convolutional approach demonstrates its efficacy in gait recognition by significantly enhancing accuracy. The proposed convolutional neural network (CNN) architecture is assessed using three benchmark datasets: CASIA, OU-ISIR, and OU-MVLP. Moreover, the proposed model is evaluated against other pre-trained models using key performance metrics such as precision, accuracy, sensitivity, specificity, and training time. The results indicate that the proposed deep CNN model outperforms existing models focused on human gait. Notably, it achieves an accuracy of approximately 99.9% for both the CASIA and OU-ISIR datasets and 99.8% for the OU-MVLP dataset while maintaining a minimal training time of around 3 min.

16.
Waste Manag ; 186: 205-213, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-38924981

RESUMO

Multilayer film packaging (MLP) waste was decomposed completely at 500 °C. Catalysts were employed to convert residue polymer to waxes via pyrolysis at 500 °C. The activities achieved from using mordenite (Si/Al = 10), H-ZSM-5 (Si/Al = 25), MCM-41, and Al-MCM-41 (Si/Al ratio of 25, 50, and 75) catalysts were studied. The yield and property of the wax were improved with the use of the catalysis with various acidity and porous structure. The low yield of the waxes, when using mordenite and H-ZSM-5 catalysts, was caused by the microporous structure and strong acidic properties of the catalysts resulting in larger amount of gas production. The MCM-41 catalyst modified with various aluminum content raised the wax yield to 60 %. Al-MCM-41(50) produced the largest amount of wax when compared to Al-MCM-41(25), Al-MCM-41(75), and MCM-41. The mild acidity and mesoporous structure of Al-MCM-41(50) significantly enhanced the paraffins structure of the obtained waxes over other structures, while lower Si/Al ratios favored the conversion of paraffins toward olefin structure. The pyrolysis of MLP with Al-MCM-41(50) produced paraffins and olefins with the middle carbon ranging (C11-20) which were similar quality to pharmaceutical grade of petroleum wax. The spent catalysts of Al-MCM-41 series gradually decreased in wax yield and paraffins composition during the sequential MLP pyrolysis; however, the activity of catalysts was recovered after calcination of the spent catalysts. Furthermore, the viscosity of waxes obtained from Al-MCM-41(50) was 2384 Pa.s at 25 °C similar to the viscosity from commercial petroleum jelly base of 2333 Pa.s.


Assuntos
Pirólise , Ceras , Ceras/química , Catálise , Embalagem de Produtos , Eliminação de Resíduos/métodos
17.
Cells ; 13(11)2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38891079

RESUMO

The transmembrane proteoglycan syndecan-4 is known to be involved in the hypertrophic response to pressure overload. Although multiple downstream signaling pathways have been found to be involved in this response in a syndecan-4-dependent manner, there are likely more signaling components involved. As part of a larger syndecan-4 interactome screening, we have previously identified MLP as a binding partner to the cytoplasmic tail of syndecan-4. Interestingly, many human MLP mutations have been found in patients with hypertrophic (HCM) and dilated cardiomyopathy (DCM). To gain deeper insight into the role of the syndecan-4-MLP interaction and its potential involvement in MLP-associated cardiomyopathy, we have here investigated the syndecan-4-MLP interaction in primary adult rat cardiomyocytes and the H9c2 cell line. The binding of syndecan-4 and MLP was analyzed in total lysates and subcellular fractions of primary adult rat cardiomyocytes, and baseline and differentiated H9c2 cells by immunoprecipitation. MLP and syndecan-4 localization were determined by confocal microscopy, and MLP oligomerization was determined by immunoblotting under native conditions. Syndecan-4-MLP binding, as well as MLP self-association, were also analyzed by ELISA and peptide arrays. Our results showed that MLP-WT and syndecan-4 co-localized in many subcellular compartments; however, their binding was only detected in nuclear-enriched fractions of isolated adult cardiomyocytes. In vitro, syndecan-4 bound to MLP at three sites, and this binding was reduced in some HCM-associated MLP mutations. While MLP and syndecan-4 also co-localized in many subcellular fractions of H9c2 cells, these proteins did not bind at baseline or after differentiation into cardiomyocyte-resembling cells. Independently of syndecan-4, mutated MLP proteins had an altered subcellular localization in H9c2 cells, compared to MLP-WT. The DCM- and HCM-associated MLP mutations, W4R, L44P, C58G, R64C, Y66C, K69R, G72R, and Q91L, affected the oligomerization of MLP with an increase in monomeric at the expense of trimeric and tetrameric recombinant MLP protein. Lastly, two crucial sites for MLP self-association were identified, which were reduced in most MLP mutations. Our data indicate that the syndecan-4-MLP interaction was present in nuclear-enriched fractions of isolated adult cardiomyocytes and that this interaction was disrupted by some HCM-associated MLP mutations. MLP mutations were also linked to changes in MLP oligomerization and self-association, which may be essential for its interaction with syndecan-4 and a critical molecular mechanism of MLP-associated cardiomyopathy.


Assuntos
Miócitos Cardíacos , Ligação Proteica , Sindecana-4 , Animais , Humanos , Ratos , Linhagem Celular , Miócitos Cardíacos/metabolismo , Sindecana-4/metabolismo , Sindecana-4/genética
18.
Sensors (Basel) ; 24(10)2024 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-38794065

RESUMO

This study focuses on advancing the field of remote sensing image target detection, addressing challenges such as small target detection, complex background handling, and dense target distribution. We propose solutions based on enhancing the YOLOv7 algorithm. Firstly, we improve the multi-scale feature enhancement (MFE) method of YOLOv7, enhancing its adaptability and precision in detecting small targets and complex backgrounds. Secondly, we design a modified YOLOv7 global information DP-MLP module to effectively capture and integrate global information, thereby improving target detection accuracy and robustness, especially in handling large-scale variations and complex scenes. Lastly, we explore a semi-supervised learning model (SSLM) target detection algorithm incorporating unlabeled data, leveraging information from unlabeled data to enhance the model's generalization ability and performance. Experimental results demonstrate that despite the outstanding performance of YOLOv7, the mean average precision (MAP) can still be improved by 1.9%. Specifically, under testing on the TGRS-HRRSD-Dataset, the MFE and DP-MLP models achieve MAP values of 93.4% and 93.1%, respectively. Across the NWPU VHR-10 dataset, the three models achieve MAP values of 93.1%, 92.1%, and 92.2%, respectively. Significant improvements are observed across various metrics compared to the original model. This study enhances the adaptability, accuracy, and generalization of remote sensing image object detection.

19.
Sci Rep ; 14(1): 11756, 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38783024

RESUMO

Visual place recognition (VPR) involves obtaining robust image descriptors to cope with differences in camera viewpoints and drastic external environment changes. Utilizing multiscale features improves the robustness of image descriptors; however, existing methods neither exploit the multiscale features generated during feature extraction nor consider the feature redundancy problem when fusing multiscale information when image descriptors are enhanced. We propose a novel encoding strategy-convolutional multilayer perceptron orthogonal fusion of multiscale features (ConvMLP-OFMS)-for VPR. A ConvMLP is used to obtain robust and generalized global image descriptors and the multiscale features generated during feature extraction are used to enhance the global descriptors to cope with changes in the environment and viewpoints. Additionally, an attention mechanism is used to eliminate noise and redundant information. Compared to traditional methods that use tensor splicing for feature fusion, we introduced matrix orthogonal decomposition to eliminate redundant information. Experiments demonstrated that the proposed architecture outperformed NetVLAD, CosPlace, ConvAP, and other methods. On the Pittsburgh and MSLS datasets, which contained significant viewpoint and illumination variations, our method achieved 92.5% and 86.5% Recall@1, respectively. We also achieved good performances-80.6% and 43.2%-on the SPED and NordLand datasets, respectively, which have more extreme illumination and appearance variations.

20.
Res Vet Sci ; 174: 105310, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38795430

RESUMO

Current research aims to generate an alternative model to classical methods in the determination of subclinical mastitis at 4 levels (healthy, suspicious, subclinical, and clinical). For this purpose, multilayer perceptron (MLP) artificial neural networks (ANN) was developed as test model. 5 variables from the physical properties of milk somatic cell count (SCC), electrical conductivity (EC), pH, density, and temperature at fore milking (TFM) were included in the model in the classification of mastitis. Model performance was validated on test data (%25) and compared with the multinomial logistic regression (MNLR). MLP model has shown a satisfactory performance with an accuracy of 95.14% and - 141 of AIC score better than the control model (MNLR) of 80.27% and - 133 AIC despite using higher number of parameters (104). Since the main problem is to diagnose subclinical mastitis, which does not cause any visible symptoms, it was important to distinguish between absolute subclinical (suspicious excluded positives) and absolute healthy (suspicious included positives) ones. Therefore, optimum cut-off threshold was evaluated for these two different scenarios with only variable SCC the gold standard indicator of subclinical mastitis and results were compared in the interpretation of model performance. The results show that the 5-variable MLP model exhibits a high sensitivity of 93.22% (AUC = 0.95 for healthy ones) at low cutoff thresholds as well. New studies should provide a better understanding by evaluating economics, sustainability, animal welfare and health aspects together to determine the optimal threshold value.


Assuntos
Aprendizado Profundo , Mastite Bovina , Leite , Animais , Mastite Bovina/diagnóstico , Leite/química , Leite/citologia , Feminino , Bovinos , Contagem de Células/veterinária , Redes Neurais de Computação , Índice de Gravidade de Doença
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA