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1.
Sensors (Basel) ; 24(17)2024 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-39275424

RESUMO

The early detection of liver fibrosis is of significant importance. Deep learning analysis of ultrasound backscattered radiofrequency (RF) signals is emerging for tissue characterization as the RF signals carry abundant information related to tissue microstructures. However, the existing methods only used the time-domain information of the RF signals for liver fibrosis assessment, and the liver region of interest (ROI) is outlined manually. In this study, we proposed an approach for liver fibrosis assessment using deep learning models on ultrasound RF signals. The proposed method consisted of two-dimensional (2D) convolutional neural networks (CNNs) for automatic liver ROI segmentation from reconstructed B-mode ultrasound images and one-dimensional (1D) CNNs for liver fibrosis stage classification based on the frequency spectra (amplitude, phase, and power) of the segmented ROI signals. The Fourier transform was used to obtain the three kinds of frequency spectra. Two classical 2D CNNs were employed for liver ROI segmentation: U-Net and Attention U-Net. ROI spectrum signals were normalized and augmented using a sliding window technique. Ultrasound RF signals collected (with a 3-MHz transducer) from 613 participants (Group A) were included for liver ROI segmentation and those from 237 participants (Group B) for liver fibrosis stage classification, with a liver biopsy as the reference standard (Fibrosis stage: F0 = 27, F1 = 49, F2 = 51, F3 = 49, F4 = 61). In the test set of Group A, U-Net and Attention U-Net yielded Dice similarity coefficients of 95.05% and 94.68%, respectively. In the test set of Group B, the 1D CNN performed the best when using ROI phase spectrum signals to evaluate liver fibrosis stages ≥F1 (area under the receive operating characteristic curve, AUC: 0.957; accuracy: 89.19%; sensitivity: 85.17%; specificity: 93.75%), ≥F2 (AUC: 0.808; accuracy: 83.34%; sensitivity: 87.50%; specificity: 78.57%), and ≥F4 (AUC: 0.876; accuracy: 85.71%; sensitivity: 77.78%; specificity: 94.12%), and when using the power spectrum signals to evaluate ≥F3 (AUC: 0.729; accuracy: 77.14%; sensitivity: 77.27%; specificity: 76.92%). The experimental results demonstrated the feasibility of both the 2D and 1D CNNs in liver parenchyma detection and liver fibrosis characterization. The proposed methods have provided a new strategy for liver fibrosis assessment based on ultrasound RF signals, especially for early fibrosis detection. The findings of this study shed light on deep learning analysis of ultrasound RF signals in the frequency domain with automatic ROI segmentation.


Assuntos
Aprendizado Profundo , Estudos de Viabilidade , Cirrose Hepática , Fígado , Redes Neurais de Computação , Ondas de Rádio , Ultrassonografia , Humanos , Cirrose Hepática/diagnóstico por imagem , Cirrose Hepática/patologia , Ultrassonografia/métodos , Masculino , Fígado/diagnóstico por imagem , Fígado/patologia , Feminino , Pessoa de Meia-Idade , Adulto , Idoso , Processamento de Imagem Assistida por Computador/métodos
2.
Sensors (Basel) ; 24(17)2024 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-39275695

RESUMO

The noninvasive measurement and sensing of vital bio signs, such as respiration and cardiopulmonary parameters, has become an essential part of the evaluation of a patient's physiological condition. The demand for new technologies that facilitate remote and noninvasive techniques for such measurements continues to grow. While previous research has made strides in the continuous monitoring of vital bio signs using lasers, this paper introduces a novel technique for remote noncontact measurements based on radio frequencies. Unlike laser-based methods, this innovative approach offers the advantage of penetrating through walls and tissues, enabling the measurement of respiration and heart rate. Our method, diverging from traditional radar systems, introduces a unique sensing concept that enables the detection of micro-movements in all directions, including those parallel to the antenna surface. The main goal of this work is to present a novel, simple, and cost-effective measurement tool capable of indicating changes in a subject's condition. By leveraging the unique properties of radio frequencies, this technique allows for the noninvasive monitoring of vital bio signs without the need for physical contact or invasive procedures. Moreover, the ability to penetrate barriers such as walls and tissues opens new possibilities for remote monitoring in various settings, including home healthcare, hospital environments, and even search and rescue operations. In order to validate the effectiveness of this technique, a series of experiments were conducted using a prototype device. The results demonstrated the feasibility of accurately measuring respiration patterns and heart rate remotely, showcasing the potential for real-time monitoring of a patient's physiological parameters. Furthermore, the simplicity and low-cost nature of the proposed measurement tool make it accessible to a wide range of users, including healthcare professionals, caregivers, and individuals seeking to monitor their own health.


Assuntos
Frequência Cardíaca , Ondas de Rádio , Humanos , Monitorização Fisiológica/métodos , Monitorização Fisiológica/instrumentação , Frequência Cardíaca/fisiologia , Sinais Vitais/fisiologia , Taxa Respiratória/fisiologia
3.
Sensors (Basel) ; 24(17)2024 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-39275704

RESUMO

In vivo phosphorus-31 (31P) magnetic resonance spectroscopy (MRS) imaging (MRSI) is an important non-invasive imaging tool for studying cerebral energy metabolism, intracellular nicotinamide adenine dinucleotide (NAD) and redox ratio, and mitochondrial function. However, it is challenging to achieve high signal-to-noise ratio (SNR) 31P MRS/MRSI results owing to low phosphorus metabolites concentration and low phosphorous gyromagnetic ratio (γ). Many works have demonstrated that ultrahigh field (UHF) could significantly improve the 31P-MRS SNR. However, there is a lack of studies of the 31P MRSI SNR in the 10.5 Tesla (T) human scanner. In this study, we designed and constructed a novel 31P-1H dual-frequency loop-dipole probe that can operate at both 7T and 10.5T for a quantitative comparison of 31P MRSI SNR between the two magnetic fields, taking into account the RF coil B1 fields (RF coil receive and transmit fields) and relaxation times. We found that the SNR of the 31P MRS signal is 1.5 times higher at 10.5T as compared to 7T, and the power dependence of SNR on magnetic field strength (B0) is 1.9.


Assuntos
Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Fósforo , Razão Sinal-Ruído , Humanos , Imageamento por Ressonância Magnética/métodos , Imageamento por Ressonância Magnética/instrumentação , Espectroscopia de Ressonância Magnética/métodos , Fósforo/química , Ondas de Rádio , Isótopos de Fósforo , Imagens de Fantasmas
4.
Phys Med Biol ; 69(18)2024 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-39168156

RESUMO

Simultaneous positron emission tomography (PET)/magnetic resonance imaging provides concurrent information about anatomic, functional, and molecular changes in disease. We are developing a second generation MR-compatible RF-penetrable TOF-PET insert. The insert has a smaller scintillation crystal size and ring diameter compared to clinical whole-body PET scanners, resulting in higher spatial resolution and sensitivity. This paper reports the initial system performance of this full-ring PET insert. The global photopeak energy resolution and global coincidence time resolution, 11.74 ± 0.03 % FWHM and 238.1 ± 0.5 ps FWHM, respectively, are preserved as we scaled up the system to a full ring comprising 12, 288 LYSO-SiPM channels (crystal size: 3.2 × 3.2 × 20 mm3). Throughout a ten-hour experiment, the system performance remained stable, exhibiting a less than 1% change in all measured parameters. In a resolution phantom study, the system successfully resolved all 2.8 mm diameter rods, achieving an average VPR of 0.28 ± 0.08 without TOF and 0.24 ± 0.07 with TOF applied. Moreover, the implementation of TOF in the Hoffman phantom study also enhanced image quality. Initial MR compatibility studies of the full PET ring were performed with it unpowered as a milestone to focus on looking for material and geometry-related artifacts. During all MR studies, the MR body coil functioned as both the transmit and receive coil, and no observable artifacts were detected. As expected, using the body coil also as the RF receiver, MR image signal-to-noise ratio exhibited degradation (∼30%), so we are developing a high quality receive-only coil that resides inside the PET ring.


Assuntos
Encéfalo , Imageamento por Ressonância Magnética , Imagens de Fantasmas , Tomografia por Emissão de Pósitrons , Tomografia por Emissão de Pósitrons/instrumentação , Imageamento por Ressonância Magnética/instrumentação , Encéfalo/diagnóstico por imagem , Ondas de Rádio , Imagem Multimodal/instrumentação , Fatores de Tempo , Processamento de Imagem Assistida por Computador/métodos , Humanos
5.
Artigo em Inglês | MEDLINE | ID: mdl-39200630

RESUMO

In this systematic review, the potential role of in vivo RF-EMF exposure combined with the administration of well-known carcinogens in tumor promotion/progression is assessed. A total of 25 papers were included in the review. Each paper was assessed for Risk of Bias and for the attribution of the quality category. A meta-analysis was conducted on 18 studies, analyzing data for nine different organs/tumors to assess the potential increased risk for the onset of tumors as well as the effects on survival. A descriptive review was performed for the remaining seven eligible papers. In most cases, the results of the meta-analysis did not reveal a statistically significant difference in tumor onset between the sham and co-exposed samples. There was a numerically small increase in the risk of malignant tumors observed in the kidney and liver, as well as benign lung tumors. The level of evidence for health effects indicated "inadequate" evidence for an association between in vivo co-exposure to RF-EMF and known carcinogens and the onset of malignant or benign tumors in most of the analyzed tissues. Nevertheless, the limited number of eligible papers/studies for most of the analyzed tissues suggests that these results cannot be considered definitively conclusive.


Assuntos
Campos Eletromagnéticos , Ondas de Rádio , Humanos , Ondas de Rádio/efeitos adversos , Campos Eletromagnéticos/efeitos adversos , Animais , Carcinogênese/efeitos da radiação , Carcinógenos/toxicidade , Neoplasias/etiologia
6.
Biomed Phys Eng Express ; 10(5)2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39173647

RESUMO

This study introduces a novel volume coil design that features two slotted end-plates connected by six rungs, resembling the traditional birdcage coil. The end rings are equipped with six evenly distributed circular slots, inspired by Mansfield's cavity resonator theory, which suggests that circular slots can generate a baseline resonant frequency. One notable advantage of this proposed coil design is its reduced reliance on electronic components compared to other volume coils, making it more efficient. Additionally, the dimensions of the coil can be theoretically computed in advance, enhancing its practicality. To evaluate the performance and safety of the coil, electromagnetic field and specific absorption rate simulations were simulated using a cylindrical saline phantom and the finite element method. Furthermore, a transceiver coil prototype optimized for 7 Tesla and driven in quadrature was constructed, enabling whole-body imaging of rats. The resonant frequency of the coil prototype obtained through experimental measurements closely matched the theoretical frequency derived from Mansfield's theory. To validate the coil design, phantom images were acquired to demonstrate its viability and assess its performance. These images also served to validate the magnetic field simulations. The experimental results aligned well with the simulation findings, confirming the reliability of the proposed coil design. Importantly, the prototype coil showcased significant improvements over a similarly-sized birdcage coil, indicating its potential for enhanced performance. The noise figure was lower in the prototype versus the birdcage coil (NFbirdcage-NFslotcage= 0.7). Phantom image data were also used to compute the image SNR, giving SNRslotcage/SNRbirdcage= 34.36/24.34. By proving the feasibility of the coil design through successful rat whole-body imaging, the study provides evidence supporting its potential as a viable option for high-field MRI applications on rodents.


Assuntos
Desenho de Equipamento , Imageamento por Ressonância Magnética , Imagens de Fantasmas , Ondas de Rádio , Animais , Imageamento por Ressonância Magnética/métodos , Imageamento por Ressonância Magnética/instrumentação , Ratos , Simulação por Computador , Campos Eletromagnéticos , Análise de Elementos Finitos , Campos Magnéticos , Imagem Corporal Total/métodos , Imagem Corporal Total/instrumentação
7.
Sensors (Basel) ; 24(16)2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39205070

RESUMO

Investigations of human brain disorders are frequently conducted in rodent models using magnetic resonance imaging. Due to the small specimen size and the increase in signal-to-noise ratio with the static magnetic field strength, dedicated small-bore animal scanners can be used to acquire high-resolution data. Ultra-high-field (≥7 T) whole-body human scanners are increasingly available, and they can also be used for animal investigations. Dedicated sensors, in this case, radiofrequency coils, are required to achieve sufficient sensitivity for the high spatial resolution needed for imaging small anatomical structures. In this work, a four-channel transceiver coil array for rat brain imaging at 7 T is presented, which can be adjusted for use on a wide range of differently sized rats, from infants to large adults. Three suitable array designs (with two to four elements covering the whole rat brain) were compared using full-wave 3D electromagnetic simulation. An optimized static B1+ shim was derived to maximize B1+ in the rat brain for both small and big rats. The design, together with a 3D-printed adjustable coil housing, was tested and validated in ex vivo rat bench and MRI measurements.


Assuntos
Encéfalo , Imageamento por Ressonância Magnética , Animais , Imageamento por Ressonância Magnética/instrumentação , Imageamento por Ressonância Magnética/métodos , Ratos , Encéfalo/diagnóstico por imagem , Razão Sinal-Ruído , Ondas de Rádio , Desenho de Equipamento , Humanos , Imagens de Fantasmas
8.
J R Soc Interface ; 21(217): 20240133, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39110232

RESUMO

The magnetic compass sense of migratory songbirds is thought to derive from magnetically sensitive photochemical reactions in cryptochromes located in photoreceptor cells in the birds' retinas. More specifically, transient radical pairs formed by light-activation of these proteins have been proposed to account for the birds' ability to orient themselves using the Earth's magnetic field and for the observation that radiofrequency magnetic fields, superimposed on the Earth's magnetic field, can disrupt this ability. Here, by means of spin dynamics simulations, we show that it may be possible for the birds to orient in a monochromatic radiofrequency field in the absence of the Earth's magnetic field. If such a behavioural test were successful, it would provide powerful additional evidence for a radical pair mechanism of avian magnetoreception.


Assuntos
Campos Magnéticos , Animais , Criptocromos/metabolismo , Ondas de Rádio , Planeta Terra , Aves Canoras/fisiologia , Modelos Biológicos , Orientação/fisiologia , Migração Animal/fisiologia
9.
Bioresour Technol ; 412: 131373, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39209234

RESUMO

Sludge pretreatment plays a crucial role in solubilizing particulate matters to release organic matter for subsequent anaerobic fermentation (AF). This study innovatively combines radio frequency (RF) heating and alkaline treatment, and finds that the combined pretreatment achieved a sludge disintegration rate of 35.11 %, which is 15.19 % and 8.48 % higher than single RF or alkaline pretreatment. The dissociated ions from the alkali are conducive to RF action on sludge. Furthermore, the combined pretreatment significantly benefits the subsequent AF experiments, resulting in a 9-fold increase in volatile fatty acids production. Considering cost-effectiveness, the optimal operating condition is a 10-minute RF treatment at pH 10 with a total cost of 4.35 × 10-3 dollars per kg soluble chemical oxygen demand (SCOD) increased. These findings provide a foundational basis for the development of a novel technology for sludge pretreatment.


Assuntos
Ácidos Graxos Voláteis , Fermentação , Esgotos , Anaerobiose , Ondas de Rádio , Concentração de Íons de Hidrogênio , Álcalis/farmacologia , Análise da Demanda Biológica de Oxigênio , Calefação , Temperatura Alta
10.
J Control Release ; 373: 853-866, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39094632

RESUMO

Radiofrequency-responsive nanoparticles (RFNPs) have drawn increasingly attentions as RF energy absorbing antenna to enhance antitumor efficacy of radiofrequency ablation (RFA). However, it remains a huge challenge for inorganic RFNPs to precisely synergize RFA with other antitumor modes in a clinically acceptable way on bio-safety and bio-compatibility. In this work, RF-responsive black phosphorus (BP) nanogel (BP-Pt@PNA) was successfully fabricated by crosslinking coordination of cisplatin with BP and temperature sensitive polymer PNA. BP-Pt@PNA exhibited strong RF-heating effect and RF-induced pulsatile release of cisplatin. Under RF irradiation, BP-Pt@PNA exhibited cytotoxic enhancement on 4T1 cells. By the synergistic effect of BP and cisplatin, BP-Pt@PNA achieved RF-stimulated systemic immune effect, thus induced enhance suppression on tumor growth and metastasis. Moreover, BP-Pt@PNA realized long-term drug retention in tumor and favorable embolization to tumor-feeding arteries. With high drug loading capacity and favorable bio-safety and bio-degradability, BP-Pt@PNA is expected as an ideal RFNP for precisely synergizing RFA with other antitumor modes in clinical application.


Assuntos
Antineoplásicos , Cisplatino , Camundongos Endogâmicos BALB C , Nanogéis , Fósforo , Cisplatino/administração & dosagem , Cisplatino/química , Cisplatino/farmacologia , Fósforo/química , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Nanogéis/química , Feminino , Ondas de Rádio , Camundongos , Neoplasias/terapia , Neoplasias/tratamento farmacológico , Polietilenoimina/química , Terapia Combinada , Liberação Controlada de Fármacos , Reagentes de Ligações Cruzadas/química , Polietilenoglicóis/química , Polietilenoglicóis/administração & dosagem
11.
J Alzheimers Dis ; 100(s1): S223-S241, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39177605

RESUMO

Background: While drainage/removal of fluid and toxins from the brain by cerebrospinal fluid (CSF) directly into venous blood is well-known, a second drainage route has recently been (re)discovered-meningeal lymphatic vessels (mLVs)-which are responsible for up to half of total brain fluid/toxin drainage. The cytokine vascular endothelial growth factor (VEGF) increases mLV diameter and numbers to increase mLV drainage, resulting in increased mLV drainage. Alzheimer's disease (AD) is characterized by low plasma and CSF levels of VEGF. Objective: To determine if non-invasive transcranial radiofrequency wave treatment (TRFT), through modulation of VEGF levels in blood and CSF, can affect removal of toxins tau and amyloid-ß (Aß) from the brain. Methods: Eight mild/moderate AD subjects were given twice-daily 1-hour TRFT sessions at home by their caregivers. Blood and CSF samples were taken at baseline and following completion of 2 months of TRFT. Results: In plasma and/or CSF, strong baseline correlations between VEGF levels and AD markers (t-tau, p-tau, Aß1-40, Aß1-42) were eliminated by TRFT. This effect was primarily due to TRFT-induced increases in VEGF levels in AD subjects with low or unmeasurable "baseline" VEGF levels. These increased VEGF levels were associated with increased clearance/drainage of tau and Aß from the brain, likely through VEGF's actions on mLVs. Conclusions: A new mechanism of TRFT is identified (facilitation of brain tau and Aß clearance via VEGF) that is likely contributory to TRFT's reversal of cognitive impairment in AD subjects. TRFT may be particularly effective for cognitive benefit in AD subjects who have low VEGF levels.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides , Encéfalo , Fator A de Crescimento do Endotélio Vascular , Proteínas tau , Humanos , Doença de Alzheimer/terapia , Doença de Alzheimer/metabolismo , Proteínas tau/líquido cefalorraquidiano , Proteínas tau/metabolismo , Peptídeos beta-Amiloides/metabolismo , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Fator A de Crescimento do Endotélio Vascular/metabolismo , Fator A de Crescimento do Endotélio Vascular/líquido cefalorraquidiano , Masculino , Feminino , Idoso , Encéfalo/metabolismo , Idoso de 80 Anos ou mais , Pessoa de Meia-Idade , Fragmentos de Peptídeos/líquido cefalorraquidiano , Ondas de Rádio
12.
PLoS One ; 19(8): e0305987, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39116190

RESUMO

Cognitive radio networks (CRN) enable wireless devices to sense the radio spectrum, determine the frequency state channels, and reconfigure the communication variables to satisfy Quality of Service (QoS) needs by reducing energy utilization. In CRN, spectrum sensing is an essential process that is highly challenging and can be addressed by several traditional techniques, such as energy detection, match filtering, etc. For now, the current models' performance is impacted by the comparatively low Signal to Noise Ratio (SNR) of recognized signals and the insignificant quantity of traditional signal samples. This research proposals a new spectral sensing technique for cognitive radio networks (SST-CRN) that addresses the drawbacks of predictable energy detection models. With the use of a deep belief network (DBN), the suggested model contributes to accomplish a nonlinear threshold based on the chicken swarm algorithm (CSA). The proposed DBN enabled SST-CRN technique goes through two phases in a organized process: offline and online. Throughout the offline phase, the DBN model is methodically trained on pre-gathered data, developing the aptitude to identify problematic patterns and examples from the spectral features of the radio environment. This stage involves extensive feature extraction, validation, and model development to ensure that the DBN can professionally represent complicated spectral dynamics. Additionally, online spectrum sensing is conducted during the real communication phase to enable real-time adaptation to dynamic changes in the spectrum environment. Offline spectrum sensing is typically performed during a devoted sensing period before actual communication begins. When combined with DBN's deep learning capabilities and CSO's innate nature-inspired algorithms, a synergistic framework is created that enables CRNs to explore and allocate incidences on their own with astonishing accuracy. The proposed solution considerably improves the spectrum efficiency and resilience of CRNs by harnessing the power of DBN, which leads to more effective resource utilization and less interference. The Simulation results show that our proposed strategy produces more accurate spectrum occupancy assessments. The result parameters such as probability of detection, SNR of -24dB, the SST-CRN perfect has increased a developed Pd of 0.810, whereas the existing methods RMLSSCRN-100 and RMLSSCRN-300 have accomplished a lower Pd of 0.577 and 0.736, respectively. Our deep learning methodology uses convolutional neural networks to automatically learn and adapt to dynamic and complicated radio environments, improving accuracy and flexibility over classic spectrum sensing approaches. Future research might focus on improving CSO algorithms to better optimize the spectrum sensing process, enhancing the reliability of DBN-enabled sensing techniques.


Assuntos
Algoritmos , Galinhas , Animais , Tecnologia sem Fio , Redes de Comunicação de Computadores , Aprendizado Profundo , Ondas de Rádio , Razão Sinal-Ruído , Cognição/fisiologia , Modelos Teóricos , Redes Neurais de Computação
13.
Front Public Health ; 12: 1425023, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39185122

RESUMO

The influence of weak radio-frequency electromagnetic field (RF-EMF) on living organisms raises new concern because of the Industrial, Scientific, and Medical (ISM) frequency band at 6.78 MHz being promoted by the AirFuel Alliance for mid-range wireless power transfer (WPT) applications and product development. Human exposure to the RF-EMF radiation is unavoidable. In this study, we employed in vitro cell culture and molecular biology approach coupled with integrated transcriptomic and proteomic analyses to uncover the effects of RF-EMF on cells at molecular and cellular levels. Our study has demonstrated that weak RF-EMF is sufficient to exert non-thermal effects on human umbilical vein endothelial cells (HUVEC). Exposure of weak RF-EMF promotes cell proliferation, inhibits apoptosis and deregulates ROS balance. Alteration of several signaling pathways and key enzymes involved in NADPH metabolism, cell proliferation and ferroptosis were identified. Our current study provide solid evidence for the first time that the present safety standards that solely considered the thermal effect of RF-EMF on cell tissue are inadequate, prompt response and modification of existing Guidelines, Standards and Regulation are warranted.


Assuntos
Apoptose , Proliferação de Células , Campos Eletromagnéticos , Células Endoteliais da Veia Umbilical Humana , NADP , Ondas de Rádio , Espécies Reativas de Oxigênio , Humanos , Espécies Reativas de Oxigênio/metabolismo , NADP/metabolismo , Ondas de Rádio/efeitos adversos , Campos Eletromagnéticos/efeitos adversos , Transdução de Sinais
14.
Skin Res Technol ; 30(9): e13898, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39213160

RESUMO

BACKGROUND: Bipolar microneedling radiofrequency (RF) treatment generates different patterns of thermal reactions, depending on the skin impedance and RF treatment parameters, including the frequency, power, conduction time, settings of sub-pulse packs, and penetrating depth and type of microneedles used. We compared the effect of sequential delivery of 1- and 2-MHz bipolar RF energy to in vivo minipig skin on thermal tissue reaction. METHODS: RF treatments at frequencies of 1 and 2 MHz were sequentially delivered to minipigs' skin in vivo. A histological study was performed to analyze RF-induced skin reactions at 1-h and at 3-, 7-, and 14-days post-treatment. RESULTS: The skin specimens demonstrated that the two different frequencies of RF treatment generated mixed patterns of the peri-electrode coagulative necrosis (PECN) according to the experimental settings and tissue impedance. In the PECN zone, the tissue coagulation induced by the first RF treatment was surrounded by the effect of the later RF treatment at the other RF frequency. In the inter-electrode non-necrotic thermal reaction zone, the effect of the latter RF treatment was widespread and deep through the dermis, which had received RF treatment at the other frequency first. The delivery of pulsed-type RF energy at sub-pulse packs of 6 or 10 provided effective RF delivery over long conduction time without excessive thermal damage of the epidermis. Nonetheless, by sequential delivery of two different RF frequencies, RF-induced tissue reactions were found to be markedly enhanced. CONCLUSION: The sequential delivery of 1- and 2-MHz RF energy induces novel histological patterns of tissue reactions, which can synergistically enhance the thermostimulatory effects of each RF setting. Moreover, variations in patterns of tissue reactions can be generated by regulating the order of frequencies and the number of sub-pulse packs of RF used.


Assuntos
Agulhas , Pele , Porco Miniatura , Animais , Suínos , Pele/efeitos da radiação , Pele/patologia , Necrose , Ondas de Rádio , Terapia por Radiofrequência/métodos , Terapia por Radiofrequência/instrumentação , Indução Percutânea de Colágeno
15.
Biomed Phys Eng Express ; 10(5)2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39094607

RESUMO

Magnetic Resonance Imaging (MRI) employs a radiofrequency electromagnetic field to create pictures on a computer. The prospective biological consequences of exposure to radiofrequency electromagnetic fields (RF EMFs) have not yet been demonstrated, and there is not enough evidence on biological hazards to offer a definite response concerning possible RF health dangers. Therefore, it is crucial to research the health concerns in reaction to RF EMFs, considering the entire exposure in terms of patients receiving MRI. Monitoring increases in temperaturein-vivothroughout MRI scan is extremely invasive and has resulted in a rise in the utilization of computational methods to estimate distributions of temperatures. The purpose of this study is to estimate the absorbed power of the brain exposed to RF in patients undergoing brain MRI scan. A three-dimensional Penne's bio-heat equation was modified to computationally analyze the temperature distributions and potential thermal effects within the brain during MRI scans in the 0.3 T to 1.5 T range (12.77 MHz to 63.87 MHz). The instantaneous temperature distributions of thein-vivotissue in the brain temperatures measured at a time, t = 20.62 s is 0.2 °C and t = 30.92 s is 0.4 °C, while the highest temperatures recorded at 1.03 min and 2.06 min were 0.4 °C and 0.6 °C accordingly. From the temperature distributions of thein-vivotissue in the brain temperatures measured, there is heat build-up in patients who are exposed to electromagnetic frequency ranges, and, consequently, temperature increases within patients are difficult to prevent. The study has, however, indicated that lengthier imaging duration appears to be related to increasing body temperature.


Assuntos
Encéfalo , Simulação por Computador , Campos Eletromagnéticos , Imageamento por Ressonância Magnética , Ondas de Rádio , Radiometria , Imageamento por Ressonância Magnética/métodos , Humanos , Encéfalo/diagnóstico por imagem , Encéfalo/efeitos da radiação , Radiometria/métodos , Temperatura , Imagens de Fantasmas
16.
Int J Mol Sci ; 25(16)2024 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-39201275

RESUMO

The widespread use of wireless communication devices has necessitated unavoidable exposure to radiofrequency electromagnetic fields (RF-EMF). In particular, increasing RF-EMF exposure among children is primarily driven by mobile phone use. Therefore, this study investigated the effects of 1850 MHz RF-EMF exposure at a specific absorption rate of 4.0 W/kg on cortical neurons in mice at postnatal day 28. The results indicated a significant reduction in the number of mushroom-shaped dendritic spines in the prefrontal cortex after daily exposure for 4 weeks. Additionally, prolonged RF-EMF exposure over 9 days led to a gradual decrease in postsynaptic density 95 puncta and inhibited neurite outgrowth in developing cortical neurons. Moreover, the expression levels of genes associated with synapse formation, such as synaptic cell adhesion molecules and cyclin-dependent kinase 5, were reduced in the cerebral cortexes of RF-EMF-exposed mice. Behavioral assessments using the Morris water maze revealed altered spatial learning and memory after the 4-week exposure period. These findings underscore the potential of RF-EMF exposure during childhood to disrupt synaptic function in the cerebral cortex, thereby affecting the developmental stages of the nervous system and potentially influencing later cognitive function.


Assuntos
Neurônios , Ondas de Rádio , Sinapses , Animais , Camundongos , Sinapses/efeitos da radiação , Sinapses/metabolismo , Neurônios/efeitos da radiação , Neurônios/metabolismo , Ondas de Rádio/efeitos adversos , Campos Eletromagnéticos/efeitos adversos , Córtex Cerebral/efeitos da radiação , Córtex Cerebral/metabolismo , Espinhas Dendríticas/efeitos da radiação , Espinhas Dendríticas/metabolismo , Memória/efeitos da radiação , Aprendizagem em Labirinto/efeitos da radiação , Masculino , Quinase 5 Dependente de Ciclina/metabolismo , Quinase 5 Dependente de Ciclina/genética , Crescimento Neuronal/efeitos da radiação , Aprendizagem/efeitos da radiação , Córtex Pré-Frontal/efeitos da radiação , Córtex Pré-Frontal/metabolismo , Proteína 4 Homóloga a Disks-Large/metabolismo
17.
ScientificWorldJournal ; 2024: 3801604, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39105157

RESUMO

The deployment of 5 G wireless technology has generated considerable interest and debate regarding its potential effects on human health. This work provides a comprehensive overview of the current scientific understanding of the potential health implications associated with 5 G technology. Drawing upon a wide range of research studies, reviews, and expert opinions, we explore the implications through which 5 G signals interact with the human body. This work presents a balanced perspective, summarizing both the potential benefits of 5 G technology, such as improved data transfer speeds, reduced latency, and enhanced connectivity, as well as concerns that have been raised about its effects on human's tissues. We discuss various aspects of health impacts, including thermal and nonthermal effects, focusing on the existing research on radiofrequency electromagnetic fields and their potential to cause adverse health outcomes. Simulation results show the negative effect of radio waves on human's tissues.


Assuntos
Campos Eletromagnéticos , Ondas de Rádio , Humanos , Ondas de Rádio/efeitos adversos , Campos Eletromagnéticos/efeitos adversos , Tecnologia sem Fio
18.
J Evid Based Integr Med ; 29: 2515690X241246293, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39135397

RESUMO

The objective were to evaluate the effects of supplementation of standardized dry extract of Rosmarinus officinalis (RO) and the application of aesthetic radiofrequency on the oxidative stress markers catalase (CAT), superoxide dismutase (SOD), non-protein thiols (NP-SH), and thiobarbituric acid reactive species (TBARS) and the biochemical markers triglycerides, total cholesterol, high density lipoprotein (HDL) cholesterol, glutamic-oxaloacetic transaminase (TGO/AST), pyruvic-glutamic transaminase (TGP/ALT), gamma glutamyl transpeptidase (gamma-GT), and creatinine. This study included 32 women received the aesthetic therapy to reduce localized fat. They were divided into the control group (n = 8) receiving placebo capsules and the intervention group (n = 24) subdivided into Group A, B, and C, each with eight members receiving supplementation with 100, 500, and 1000 mg/day of standardized dry extract of RO, respectively. The Universal Trial Number (UTN) - U1111-1274-6255. Supplementation with RO (500 mg/day) demonstrated a reduction in oxidative stress (quantified with through a significant increase in NP-SH and a reduction in SOD and CAT enzymes). The radiofrequency aesthetic treatment did not promote an increase in oxidative stress; however, it caused significant changes in total cholesterol, HDL cholesterol, and creatinine. RO is a plant with antioxidant effects and its oral consumption is safe in selected women subjects in hepatic and renal markers.


Assuntos
Suplementos Nutricionais , Estresse Oxidativo , Extratos Vegetais , Rosmarinus , Humanos , Feminino , Estresse Oxidativo/efeitos dos fármacos , Método Duplo-Cego , Rosmarinus/química , Adulto , Extratos Vegetais/farmacologia , Ondas de Rádio , Superóxido Dismutase/metabolismo , Superóxido Dismutase/sangue , Pessoa de Meia-Idade , Biomarcadores/sangue , Antioxidantes/farmacologia , Catalase/metabolismo , Catalase/sangue , Adulto Jovem
19.
Compr Rev Food Sci Food Saf ; 23(5): e13425, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39136978

RESUMO

Thermal processing is commonly employed to ensure the quality and extend the shelf-life of fruits and vegetables. Radio frequency (RF) heating has been used as a promising alternative treatment to replace conventional thermal processing methods with advantages of rapid, volumetric, and deep penetration heating characteristics. This article provides comprehensive information regarding RF heating uniformity and applications in processing of fruit and vegetable products, including disinfestation, blanching, drying, and pasteurization. The dielectric properties of fruits and vegetables and their products have also been summarized. In addition, recommendations for future research on RF heating are proposed to enhance practical applications for fruits and vegetables processing in future.


Assuntos
Manipulação de Alimentos , Frutas , Ondas de Rádio , Verduras , Frutas/química , Verduras/química , Manipulação de Alimentos/métodos , Pasteurização/métodos , Temperatura Alta
20.
Front Public Health ; 12: 1419525, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39145180

RESUMO

Background: The widespread use of radiofrequency (RF) sources, ranging from household appliances to telecommunications devices and military equipment, raises concerns among people and regulatory agencies about the potential health risks of RF exposure. Consequently, several in vitro and in vivo studies have been done to investigate the biological effects, in particular non-thermal, of this non-ionizing radiation. To date, this issue is still being debated due to the controversial results that have been reported. Furthermore, the impact of different RF signal modulations on biological systems remains poorly investigated. The present in vitro study aims to evaluate the cytotoxicity and genotoxicity of continuous or pulsed 1.6 GHz RF in human dermal fibroblasts (HDF). Methods: HDF cultures were exposed to continuous and pulsed 1.6 GHz RF, for 2 h, with Specific Absorption Rate (SAR) of 0.4 W/kg. The potential biological effects of 1.6 GHz RF on HDF were assessed with a multi-methodological approach, analyzing the effects on cell cycle, ultrastructure, protein expression, mitotic spindle, CREST stained micronuclei, chromosome segregation and γ-H2AX/53BP1 foci. Results: 1.6 GHz RF exposure modified proteins expression and morphology of HDF. Specifically, the expression of different heat-shock proteins (HSP) (i.e., HSP-90, HSP-60, and HSP-25) and phospho-AKT were affected. In addition, both continuous and pulsed RF modified the cytoskeletal organization in HDF and increased the number of lysosomes, while the formation of autophagosomes was observed only after pulsed RF exposure. Mitotic spindle anomalies were also found after exposure. However, no significant effect was observed on cell cycle, chromosome segregation, CREST-stained micronuclei and γ-H2AX/53BP1 foci. Conclusion: The results of the present study show the absence of genotoxic damage in 1.6 GHz RF exposed HDF and, although mitotic spindle alterations were observed, they did not have an aneugenic effect. On the other hand, changes in some proteins expression and cell ultrastructure in exposed HDF suggest that RF can potentially induce cell alterations at the morphological and molecular levels.


Assuntos
Fibroblastos , Ondas de Rádio , Humanos , Fibroblastos/efeitos da radiação , Ondas de Rádio/efeitos adversos , Dano ao DNA , Ciclo Celular/efeitos da radiação , Células Cultivadas
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