Journal of Biomedical Physics and Engineering最新文献

Background: Nowadays, the growing use of non-ionizing electromagnetic radiation has raised concerns about its potential health effects.

Objective: In this work, an animal model exposed to Wi-Fi and jammer signals was used to examine the effects of non-ionizing electromagnetic radiation on kidney and liver function.

Material and methods: In this experimental study, twenty-one male Wistar Albino rats were separated into three groups: Wi-Fi, jammer, and sham groups. The animals were exposed to electromagnetic radiation for two hours per day for two weeks. Blood samples and kidney and liver tissues were collected and analyzed for various biochemical parameters.

Results: The findings of this study showed a mild inflammatory response in both tissues after exposure to the fields. However, no notable or serious alterations were noted in the groups under study. The Wi-Fi and jammer signals had no significant impact on creatinine, albumin, blood urea nitrogen, cholesterol, high-density lipoprotein, triglycerides, albumin/globulin ratio, total bilirubin, direct bilirubin, and alkaline phosphatase levels. However, the jammer group revealed a notable decline in low-density lipoprotein compared to the sham group. Significant differences were observed in the levels of aspartate aminotransferase and alanine aminotransferase between the Wi-Fi and sham groups but not between the other groups.

Conclusion: This work emphasizes the importance of considering individual organ characteristics in response to electromagnetic radiation exposure. Prolonged or closer exposure to the radiation source may significantly affect the organ function.

Blue-blocking lenses, including both spectacles and intraocular lenses, are designed to selectively reduce the intensity of short-wavelength visible light and UV radiation using a chromophore. Unlike standard spectacle lenses, which only offer varying degrees of UV protection, blue-blocking lenses provide additional benefits such as enhancing visual performance, reducing eye fatigue from digital screens, protecting the retina from phototoxicity, and minimizing disruption of the circadian rhythm caused by blue light-emitting devices used in the evening. Research has shown that the length of the eye tends to increase over time, especially during the first 10 months of life, indicating the importance of this period in eye development. The Purkinje shift is a phenomenon where the eye becomes more sensitive to blue light in the dark, and it is a normal physiological process. However, there is concern that prolonged use of blue-cut lenses in children may affect the development of eye length and contribute to an increase in refractive eye disorders.

Background: Hemiplegic Cerebral Palsy (HCP) causes significant motor impairments, due to disrupted Functional Connectivity (FC) between brain regions. Low-Frequency Repetitive Transcranial Magnetic Stimulation (LF-rTMS) has emerged as a potential therapeutic technique for restoring FC and motor recovery.

Objective: This study aimed to evaluate the effects of LF-rTMS on FC in children with spastic HCP.

Material and methods: This Randomized Controlled Trial (RCT) included ten children with spastic HCP, aged 4 to 13 years. Six children received 12 sessions of LF-rTMS, while four in the control group underwent 12 sessions of sham stimulation. Functional Magnetic Resonance Imaging (fMRI) was used to assess intra- and interhemispheric FC during passive knee movements of the affected limb.

Results: LF-rTMS induced region-specific reductions in interhemispheric FC, particularly between the contralesional ventral premotor area (cPMv) and both the ipsilesional primary somatosensory cortex (iS1) (for effect size T=-2.60, P-value=0.048, FDR-corrected) and the ipsilesional primary motor area (iM1) (T=-2.45, P-value=0.048, FDR-corrected). These findings suggest modulation of interhemispheric motor-sensory pathways. Concurrently, localized increases in FC were observed in contralesional regions, and FC decreased between the ipsilesional Supplementary Motor Area (SMA) and the secondary somatosensory cortex (S2) (T=-3.11, P-value=0.041, FDR-corrected).

Conclusion: LF-rTMS may modulate FC and hold promise as a rehabilitative intervention for improving motor function in children with HCP.

Background: Diabetic retinopathy (DR), a diabetes complication, causes blindness by damaging retinal blood vessels. While deep learning has advanced DR diagnosis, many models face issues like inconsistent performance, limited datasets, and poor interpretability, reducing their clinical utility.

Objective: This research aimed to develop and evaluate a deep learning structure combining Convolutional Neural Networks (CNNs) and transformer architecture to improve the accuracy, reliability, and generalizability of DR detection and severity classification.

Material and methods: This computational experimental study leverages CNNs to extract local features and transformers to capture long-range dependencies in retinal images. The model classifies five types of retinal images and assesses four levels of DR severity. The training was conducted on the augmented APTOS 2019 dataset, addressing class imbalance through data augmentation techniques. Performance metrics, including accuracy, Area Under the Curve (AUC), specificity, and sensitivity, were used for metric evaluation. The model's robustness was further validated using the IDRiD dataset under diverse scenarios.

Results: The model achieved a high accuracy of 94.28% on the APTOS 2019 dataset, demonstrating strong performance in both image classification and severity assessment. Validation on the IDRiD dataset confirmed its generalizability, achieving a consistent accuracy of 95.23%. These results indicate the model's effectiveness in accurately diagnosing and assessing DR severity across varied datasets.

Conclusion: The proposed Artificial intelligence (AI)-powered diagnostic tool improves diabetic patient care by enabling early DR detection, preventing progression and reducing vision loss. The proposed AI-powered diagnostic tool offers high performance, reliability, and generalizability, providing significant value for clinical DR management.

Background: Nanocoating of biomedical materials has emerged as a crucial emerging discipline, to enhance tribological behaviors, durability, and performance of materials.

Objective: This study aimed to investigate the tribological characteristics of substrates coated with Hydroxyapatite (HAp) and Silica glass (SiO2).

Material and methods: In this experimental study, the substrates were Ti-6Al-4V, a widely used titanium alloy for osseointegration implants. The substrates were coated with 90% HAp and 10% SiO2 via the plasma cold spray technique. The friction examination was analyzed at room temperature and under the Simulated Body Fluid (SBF) condition using the pin-on-disc technique.

Results: The microstructural analysis confirmed the coated technique in producing a nano-sized layer. While the pin-on-disc test indicates that nanocoated Ti-6Al-4V specimens have a significantly higher average coefficient of friction than uncoated specimens, surface roughness is the primary contributor.

Conclusion: Through microstructure properties and tribological behavior, the coated alloy may provide a benefit in circumstances, in which lubrication availability is restricted or undesirable, such as when the implant comes into contact with the bone interface.

Background: Cross-coherence is used to evaluate the correlation between two sources of signals and to evaluate the power transfer between input and output of two linear sources. Visual evoked potential (VEP) is used to study the visual pathway of patients according to the ISCEV standard.

Objective: The cross-coherence analysis is used to examine the interconnections between channels across two age groups mature and young.

Material and methods: This experimental and analysis study implements a statistical method based on coherence analysis horizontally, vertically, and diagonally across the brain hemisphere. It investigates and discriminates the VEP responses related to age in two groups, matured and young.

Results: The coherence results compared in both the time and frequency domains for the two age groups. In the young age group, there is greater coherence between the occipital lobes compared to the frontal lobes in horizontal coherence. The diagonal coherence in the young age group was less than 0.4, whereas it exceeded 0.4 and 0.5 in the mature age group for the time and frequency domains, respectively.

Conclusion: The frequency coherence shows the spectrum of an alpha wave of frequency 15 Hz in the matured group. The vertical coherence of matured age group shows an extra peak in the range of late Alpha wave at 25 Hz compared to that in the young age group. The diagonal coherence shows the frequency peak of the Alpha wave at 15 Hz in the matured age group. While the young group shows the late Alpha wave at around 25 Hz.

Background: High-intensity Focused Ultrasound (HIFU) is a rapidly developing non-invasive treatment method for tumors in recent years.

Objective: The present study aimed to investigate the lesion and temperature effects of HIFU combined with different concentrations and volumes of ethanol on porcine liver.

Material and methods: In this experimental study, different concentrations and volumes of ethanol were injected into the focal area of porcine liver using B-mode ultrasound, and the focal temperature was monitored using a k-type needle thermocouple. The peak negative pressure and sound intensity at the focal point of porcine liver were calculated by Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation. Further, the presence of cavitation effects within porcine liver was further determined by ultrasound hyperechoic. The differences in lesion volume and temperature, caused by different concentrations and volumes of ethanol on porcine liver, were measured.

Results: HIFU irradiation combined with ethanol injection caused greater lesion volume and higher focal temperature in porcine liver. At the same HIFU irradiation power, an increase in the volume of ethanol resulted in an increase in lesion volume and focal temperature. At a fixed volume of ethanol injected and HIFU irradiation power, higher ethanol concentrations resulted in higher lesion volumes and focal temperature.

Conclusion: The combination of HIFU and ethanol synergistically affects the lesion of porcine liver, manifested as the larger the ethanol concentration and volume, the larger the lesion volume and the higher the focal temperature.

Background: Radiomics with single Region of Interest (ROI) and single-sequence Magnetic Resonance Imaging (MRI) may facilitate the segmentation reproducibility and radiomics workflow due to a time-consuming and complicated delineation of that in multi-sequence MRI images.

Objective: This study aimed to evaluate the performance of the radiomics approach in grading glioma based on a single-ROI delineation as Gross Tumor Volume (GTV) in a single - sequence as contrast-enhanced T1-weighted MRI.

Material and methods: This retrospective study was conducted on contrast-enhanced T1 weighted (CE T1W) MRI images of 60 grade II and 60 grade III glioma patients. The GTV regions were manually delineated. Radiomics features were extracted per patient. The segmentation reproducibility of the robust features was evaluated in several repetitions of GTV delineation. Finally, a linear Support Vector Machine (SVM) assessed the classification performance of the robust features.

Results: Four significant robust features were selected for training the model (P-value<0.05). The average Intraclass Correlation Coefficient (ICC) of the four features was 0.96 in several repetitions of GTV delineation. The linear SVM model differentiated grades II and III of glioma with an Area Under the Curve (AUC) of 0.9 in the training group.

Conclusion: High predicting power for glioma grading can be achieved with radiomics analysis by a single-ROI delineated on a single-sequence MRI image (CE T1W). In addition, single-ROI segmentation can increase radiomics reproducibility.

Natural selection, a cornerstone of evolutionary biology, shapes the adaptations organisms develop to survive environmental pressures. This paper explores how natural selection drives biological adaptations to radiation exposure. We examine the genetic mechanisms at play, exemplified by the enhanced DNA repair capabilities observed in bacteria like Escherichia coli (E. coli) following exposure to radiation. We then investigate adaptations in humans residing in high-background radiation areas, highlighting potential genetic variations for radiation resistance. Finally, the contemporary relevance of natural selection is discussed, emphasizing its role in the emergence of antibiotic-resistant bacteria and the need for sustainable medical practices. By studying these adaptations, we gain a deeper understanding of evolution and its implications for medicine, conservation, and our overall understanding of life.