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1.
Diagnostics (Basel) ; 13(21)2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37958260

RESUMO

Retinal blood vessel segmentation is a valuable tool for clinicians to diagnose conditions such as atherosclerosis, glaucoma, and age-related macular degeneration. This paper presents a new framework for segmenting blood vessels in retinal images. The framework has two stages: a multi-layer preprocessing stage and a subsequent segmentation stage employing a U-Net with a multi-residual attention block. The multi-layer preprocessing stage has three steps. The first step is noise reduction, employing a U-shaped convolutional neural network with matrix factorization (CNN with MF) and detailed U-shaped U-Net (D_U-Net) to minimize image noise, culminating in the selection of the most suitable image based on the PSNR and SSIM values. The second step is dynamic data imputation, utilizing multiple models for the purpose of filling in missing data. The third step is data augmentation through the utilization of a latent diffusion model (LDM) to expand the training dataset size. The second stage of the framework is segmentation, where the U-Nets with a multi-residual attention block are used to segment the retinal images after they have been preprocessed and noise has been removed. The experiments show that the framework is effective at segmenting retinal blood vessels. It achieved Dice scores of 95.32, accuracy of 93.56, precision of 95.68, and recall of 95.45. It also achieved efficient results in removing noise using CNN with matrix factorization (MF) and D-U-NET according to values of PSNR and SSIM for (0.1, 0.25, 0.5, and 0.75) levels of noise. The LDM achieved an inception score of 13.6 and an FID of 46.2 in the augmentation step.

2.
Sensors (Basel) ; 23(20)2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37896692

RESUMO

One of the most prevalent diseases affecting women in recent years is breast cancer. Early breast cancer detection can help in the treatment, lower the infection risk, and worsen the results. This paper presents a hybrid approach for augmentation and segmenting breast cancer. The framework contains two main stages: augmentation and segmentation of ultrasound images. The augmentation of the ultrasounds is applied using generative adversarial networks (GAN) with nonlinear identity block, label smoothing, and a new loss function. The segmentation of the ultrasounds applied a modified U-Net 3+. The hybrid approach achieves efficient results in the segmentation and augmentation steps compared with the other available methods for the same task. The modified version of the GAN with the nonlinear identity block overcomes different types of modified GAN in the ultrasound augmentation process, such as speckle GAN, UltraGAN, and deep convolutional GAN. The modified U-Net 3+ also overcomes the different architectures of U-Nets in the segmentation process. The GAN with nonlinear identity blocks achieved an inception score of 14.32 and a Fréchet inception distance of 41.86 in the augmenting process. The GAN with identity achieves a smaller value in Fréchet inception distance (FID) and a bigger value in inception score; these results prove the model's efficiency compared with other versions of GAN in the augmentation process. The modified U-Net 3+ architecture achieved a Dice Score of 95.49% and an Accuracy of 95.67%.


Assuntos
Neoplasias da Mama , Processamento de Imagem Assistida por Computador , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Ultrassonografia , Ultrassonografia Mamária , Neoplasias da Mama/diagnóstico por imagem
3.
Sensors (Basel) ; 23(15)2023 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-37571505

RESUMO

With the onset of 5G technology, the number of users is increasing drastically. These increased numbers of users demand better service on the network. This study examines the millimeter wave bands working frequencies. Working in the millimeter wave band has the disadvantage of interference. This study aims to analyze the impact of different interference conditions on unmanned aerial vehicle use scenarios, such as open-air gatherings and indoor-outdoor sports stadiums. Performance analysis was carried out in terms of received power and path loss readings.

4.
Sensors (Basel) ; 23(14)2023 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-37514719

RESUMO

With the development of the Internet of Things (IoT), the number of devices will also increase tremendously. However, we need more wireless communication resources. It has been shown in the literature that non-orthogonal multiple access (NOMA) offers high multiplexing gains due to the simultaneous transfer of signals, and massive multiple-input-multiple-outputs (mMIMOs) offer high spectrum efficiency due to the high antenna gain and high multiplexing gains. Therefore, a downlink mMIMO NOMA cooperative system is considered in this paper. The users at the cell edge in 5G cellular system generally suffer from poor signal quality as they are far away from the BS and expend high battery power to decode the signals superimposed through NOMA. Thus, this paper uses a cooperative relay system and proposes the mMIMO NOMA double-mode model to reduce battery expenditure and increase the cell edge user's energy efficiency and sum rate. In the mMIMO NOMA double-mode model, two modes of operation are defined. Depending on the relay's battery level, these modes are chosen to utilize the system's energy efficiency. Comprehensive numerical results show the improvement in the proposed system's average sum rate and average energy efficiency compared with a conventional system. In a cooperative NOMA system, the base station (BS) transmits a signal to a relay, and the relay forwards the signal to a cluster of users. This cluster formation depends on the user positions and geographical restrictions concerning the relay equipment. Therefore, it is vital to form user clusters for efficient and simultaneous transmission. This paper also presents a novel method for efficient cluster formation.

5.
Sensors (Basel) ; 23(2)2023 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-36679767

RESUMO

Mobile applications have rapidly grown over the past few decades to offer futuristic applications, such as autonomous vehicles, smart farming, and smart city. Such applications require ubiquitous, real-time, and secure communications to deliver services quickly. Toward this aim, sixth-generation (6G) wireless technology offers superior performance with high reliability, enhanced transmission rate, and low latency. However, managing the resources of the aforementioned applications is highly complex in the precarious network. An adversary can perform various network-related attacks (i.e., data injection or modification) to jeopardize the regular operation of the smart applications. Therefore, incorporating blockchain technology in the smart application can be a prominent solution to tackle security, reliability, and data-sharing privacy concerns. Motivated by the same, we presented a case study on public safety applications that utilizes the essential characteristics of artificial intelligence (AI), blockchain, and a 6G network to handle data integrity attacks on the crime data. The case study is assessed using various performance parameters by considering blockchain scalability, packet drop ratio, and training accuracy. Lastly, we explored different research challenges of adopting blockchain in the 6G wireless network.


Assuntos
Inteligência Artificial , Blockchain , Reprodutibilidade dos Testes , Inteligência , Agricultura , Segurança Computacional
6.
J Imaging ; 8(7)2022 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-35877634

RESUMO

Because of the large variabilities in brain tumors, automating segmentation remains a difficult task. We propose an automated method to segment brain tumors by integrating the deep capsule network (CapsNet) and the latent-dynamic condition random field (LDCRF). The method consists of three main processes to segment the brain tumor-pre-processing, segmentation, and post-processing. In pre-processing, the N4ITK process involves correcting each MR image's bias field before normalizing the intensity. After that, image patches are used to train CapsNet during the segmentation process. Then, with the CapsNet parameters determined, we employ image slices from an axial view to learn the LDCRF-CapsNet. Finally, we use a simple thresholding method to correct the labels of some pixels and remove small 3D-connected regions from the segmentation outcomes. On the BRATS 2015 and BRATS 2021 datasets, we trained and evaluated our method and discovered that it outperforms and can compete with state-of-the-art methods in comparable conditions.

7.
Urology ; 78(3): 511-4, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21782225

RESUMO

OBJECTIVE: To evaluate the frequency and potential risk factors for infection-related complications after transrectal prostate biopsy and to propose adjustments in current antimicrobial prophylaxis recommendations. METHODS: During 2008-2010, 107 patients underwent transrectal ultrasound-guided biopsies of the prostate at our institution. Charts were reviewed for infection-related complications within 30 days of the procedure. Potential risk factors were evaluated, including age, diabetes mellitus, chronic constipation/diverticular disease, prior use of quinolones, enema and prostatitis, on the pathology report. For patients with acute prostatitis, urine and blood samples were assessed for bacteriology and antibiotic susceptibility. RESULTS: Of our 107 patients, acute prostatitis developed in 10 (9.3%). The most significant risk factor was prior use of a fluoroquinolone antimicrobial, with acute prostatitis developing in 7 (17.1%) of 41 patients who had used a fluoroquinolone compared with 3 (4.5%) of 66 patients who had not (P=.042). Patients who received an enema before the procedure were slightly less likely to develop prostatitis (P=.061). Of 8 positive specimens, the organisms isolated were Escherichia coli in 6, Klebsiella pneumoniae in 1, and Staphylococcus epidermidis in one. Isolated Gram-negative organisms were fluoroquinolone-resistant in 85.7% of samples. CONCLUSION: Prior fluoroquinolone intake is a significant risk factor behind a rising incidence of acute prostatitis after transrectal prostate biopsy. Identified pathogens are mostly Gram-negative organisms with a high rate of fluoroquinolone resistance. Alternative prophylaxis regimens for the biopsy procedure should be considered in patients with recent quinolone intake.


Assuntos
Antibacterianos/uso terapêutico , Infecções Bacterianas/etiologia , Biópsia por Agulha/efeitos adversos , Fluoroquinolonas/uso terapêutico , Próstata/patologia , Prostatite/etiologia , Doença Aguda , Idoso , Idoso de 80 Anos ou mais , Infecções Bacterianas/tratamento farmacológico , Farmacorresistência Bacteriana , Humanos , Masculino , Pessoa de Meia-Idade , Prostatite/tratamento farmacológico , Prostatite/microbiologia , Fatores de Risco
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