Search Results (2,190)

Background and Objectives: Primary vesicoureteral reflux (VUR) is a common pediatric urological disorder that can lead to significant renal morbidity if undetected or improperly managed. Ultrasound (US) plays a pivotal role in its assessment, providing a radiation-free tool to prenatal assessment, diagnosis, treatment, and long-term follow-up. This study aims to systematically review the literature on the use of US in pediatric primary VUR, emphasizing its applications in prenatal and postnatal diagnosis, intraoperative guidance, and follow-up monitoring. Methods: A systematic review of the literature was performed on PubMed in accordance with PRISMA guidelines. The research strategy used the following keywords: Ultrasound Vesicoureteral reflux, VUR Ultrasound, and VUR Sonography. A total of 2222 records were initially identified. After screening titles and abstracts for relevance, 2165 studies were excluded because they did not focus on ultrasound procedures, did not specify age limits, were redundant, involved non-homogeneous populations, or were unavailable in full text. Results: Prenatal US enables early identification of urinary tract anomalies suggestive of VUR, facilitating targeted postnatal evaluation. Postnatally, contrast-enhanced voiding ultrasound (CEVUS) offers a non-ionizing method for VUR confirmation or exclusion. Intraoperatively, US improves the accuracy and efficacy of bulking agent placement, potentially enhancing surgical outcomes. In follow-up, US remains essential for both conservatively managed and surgically treated patients, enabling timely detection of complications or recurrence. Conclusions: Ultrasound represents a useful tool in the management of pediatric primary VUR, applicable across all clinical stages, avoiding radiation exposure, and improving surgical effectiveness and follow-up management. Full article

Breast cancer remains a leading cause of global mortality. According to international cancer data, significant progress has been made in treating breast cancer; however, metastasis and drug resistance continue to be the primary causes of mortality for many patients. This study investigated the modulation of apoptosis-related genes in response to ionizing radiation and estrogen exposure based on a human breast epithelial cell model (MCF-10F and its transformed variants: Estrogen, Alpha3, Alpha5, Tumor2) previously established, where cells were treated with high linear energy transfer alpha particles, with or without 17β-estradiol. Gene expression profiling was performed using an Affymetrix U133A microarray, and bioinformatic analyses assessed differential expression, estrogen receptor status, and correlations with overall survival. Distinct gene expression patterns emerged across cell lines and tumor subtypes. TP53 expression correlated positively with TP63, BIK, CFLAR, BIRC3, and BCLAF1. TP63, PERP, CFLAR, BCLAF1, GULP1, and BIRC3 were elevated in normal tissue, whereas BIK, PHLDA2, and BBC3 were upregulated in tumors. ER-positive tumors exhibited higher TP63, BIK, BCLAF1, and BBC3 expression, while ER-negative tumors showed increased PERP, CFLAR, BIRC3, and PHLDA2. Notably, elevated BCLAF1 expression was associated with poorer survival in Luminal A patients, and high PHLDA2 expression correlated with reduced survival in Luminal B cases. These findings indicate that resistance to apoptosis is a fundamental mechanism in breast cancer progression and therapeutic evasion. Breast tumors selectively alter the expression of key genes to promote growth, evade apoptosis, and develop therapeutic resistance. The differential expression and correlations of these apoptosis-related genes highlight their potential as molecular targets for future personalized cancer therapies and as valuable biomarkers for prognostic stratification and predicting therapeutic response. Full article

Radiotherapy employs high-energy X-rays to precisely target tumor tissues while minimizing damage to the surrounding healthy structures. Although its clinical efficacy is well established, the immunomodulatory effects of ionizing radiation remain complex and context-dependent. This study investigated the biological effects of radiotherapeutic doses on immune cells by evaluating lymphocyte viability, phenotypic profiles, and cytokine expression levels. Peripheral blood mononuclear cells (PBMCs) were isolated from six healthy donors and irradiated with 0, 2, or 6 Gy using a 6 MV linear accelerator (LINAC). Dose validation with an ionization chamber demonstrated strong agreement between estimated and measured values (intraclass correlation coefficient = 1, 95% CI). Immune subsets, including T cells (CD3+), helper T cells (CD3+CD4+), cytotoxic T cells (CD3+CD8+), regulatory T cells (CD3+CD4+Foxp3+), and natural killer (CD3-CD56+) cells, along with intracellular cytokines interleukin-12 (IL-12) and interferon-gamma (IFN-γ), were analyzed via flow cytometry at multiple time points. The results showed a significant, dose-dependent decline in overall lymphocyte viability (p < 0.01) compared to control. Cytotoxic T cells were the most radiosensitive, followed by helper and regulatory T cells, while NK cells were the most radioresistant. IL-12 expression initially increased post-irradiation, while IFN-γ levels remained variable. These findings demonstrate that radiation induces distinct alterations in immune phenotypes and cytokine profiles, which may shape the immune response. Immune profiling following irradiation may therefore provide valuable insights for optimizing combination strategies that integrate radiotherapy and immunotherapy in cancer treatment. Full article

Patients presenting with abdominal pain and/or distension require rapid diagnostics to narrow the differential diagnosis from a long list of obstructive gastrointestinal (GI) pathologies that may appear clinically similar but warrant distinct management. While the workup of abdominal distension currently centers around computed tomography (CT), this modality is costly, requires radiation exposure, and necessitates patient transport, potentially delaying care. In contrast, point-of-care ultrasound (POCUS) avoids ionizing radiation and the need for patient transport while providing some insight into the gastrointestinal size and function. While POCUS cannot currently replace CT in the definitive diagnosis of GI obstructive pathologies, it remains a promising tool to help with the initial triage and monitoring responses to therapy for several causes of functional and/or mechanical GI obstruction, such as gastric dilation, ileus, and small bowel obstruction. Because the obstruction severity and features can evolve over time, POCUS enables serial examinations to monitor the progression or resolution. This manuscript reviews characteristic sonographic findings that help distinguish obstructive GI conditions and highlights practical techniques for integrating gastric and intestinal POCUS to improve diagnostic accuracy and expedite treatment. Full article

Background: Inflammatory Bowel Disease (IBD), comprising Crohn’s disease and ulcerative colitis, requires accurate assessment over time. Imaging techniques play a crucial role in diagnosis, monitoring disease activity, and guiding therapeutic response. This review summarizes the current evidence on radiologic imaging techniques in IBD, focusing on intestinal ultrasound (IUS), computed tomography enterography (CTE), magnetic resonance enterography (MRE), and other emerging technologies. Methods: A literature review was conducted using PubMed, EMBASE, Scopus, and the Cochrane Library, encompassing publications up to 31 October 2024. Results: IUS offers a non-invasive tool for assessing bowel wall thickness, vascularity, and complications. CTE and MRE provide detailed visualization of luminal and extraluminal disease, with MRE preferred for routine monitoring due to the absence of ionizing radiation. Standardized indices and scoring systems aid in objective disease activity assessment. Emerging technologies like Positron Emission Tomography (PET)/MRI and radiomics show promise in combining metabolic and morphological information for complex cases. Conclusions: Imaging has a central role in IBD management, with IUS, CTE, and MRE demonstrating high diagnostic accuracy. Radiomics and Artificial Intelligence (AI) are paving the way for precision imaging. Integrating advanced imaging techniques, scoring systems, and AI-driven analytics represents a transformative step toward more effective and individualized care for patients with IBD. Full article

Lead halide perovskites, including single-cation (MAPbI₃, FAPbI₃, CsPbI₃) and mixed-cation (Cs_0.12FA_0.88PbI₃, Cs_0.1MA_0.15FA_0.75PbI₃) compositions, are promising for both space photovoltaics and γ-ray detection due to their tunable optoelectronic properties. However, their response to high-energy radiation remains critical for reliable operation. We performed Monte-Carlo simulations using GEANT4 to investigate photon interactions (0.1–90 MeV) with perovskites of varying composition and thickness (1 cm to 1 μm). Results indicate that heavy atoms (Pb, I) dominate photoelectric absorption and scattering, broadly similar absorbed energies and event rates across compositions. Cs-containing perovskites exhibit slightly higher absorption and ionization, whereas FA- and MA-rich compositions show reduced photoelectric and Rayleigh scattering. Layer thickness strongly influences the radiation response: ultrathin films display fewer interactions with higher per-event energy, while millimeter-scale layers achieve efficient absorption and enable pair-production events at MeV energies. The sequence of dominant processes follows the expected energy dependence: photoelectric effect at low energies, Compton and Rayleigh scattering at intermediate energies, and pair production at high energies. These findings demonstrate that perovskite γ-interaction is primarily governed by heavy-atom content, with A-site cations fine-tuning the process balance, and that device performance for detection or photovoltaics depends critically on layer thickness. Full article

Proton therapy enables precise dose delivery to tumors while sparing healthy tissues, offering significant advantages over conventional radiotherapy. Accurate prediction of biological doses requires detailed knowledge of radiation interactions with biological targets, especially DNA, a key site of radiation-induced damage. While most biophysical models (LEM, mMKM, NanOx) rely on water as a surrogate, this simplification neglects the complexity of real biomolecules. In this work, we calculate the stopping power and range of protons in liquid water, dry DNA, and hydrated DNA using semi-empirical cross sections for ionization, electronic excitation, electron capture, and electron loss by protons and neutral hydrogen in the 10 keV–100 MeV energy range. Additionally, ionization cross sections for uracil are computed to explore potential differences between DNA and RNA damage. Our results show excellent agreement with experimental and ab initio data, highlighting significant deviations in stopping power and range between water and DNA. Notably, the stopping power of DNA exceeds that of water at most energies, reducing proton ranges in dry and hydrated DNA by up to 20% and 26%, respectively. These findings provide improved input for Monte Carlo simulations and biophysical models, enhancing RBE predictions and dose accuracy in hadrontherapy. Full article

Objective: This study was conducted to evaluate the potential radioprotective and therapeutic effects of dexmedetomidine (DEX), a selective α2-adrenergic receptor (α2AR) agonist, against ionizing X-ray-induced small intestinal injury in a dose-dependent manner. Methods: Male Sprague Dawley rats were randomly categorized into four groups. These groups were the Control, Ionizing Radiation (IR, 8 Gy X-ray), IR+DEX 100 µg/kg, and IR+DEX 200 µg/kg. DEX was administered intraperitoneally to the treatment groups 30 min before radiation exposure. All groups were sacrificed 24 h following irradiation. Firstly, the small intestinal tissues were evaluated histopathologically (H&E staining). Subsequently, levels of malondialdehyde (MDA) and glutathione (GSH), as markers of oxidative stress, were measured, and immunohistochemical expression of Caspase-3 and 8-hydroxy-2′-deoxyguanosine (8-OHdG) was analyzed. Results: In the IR group, significant histopathological alterations were observed, including villus atrophy and villus loss due to fusion, crypt loss, and mucosal degeneration. Additionally, there was an increase in MDA levels, a decrease in GSH levels, and a marked elevation in the expression of Caspase-3 and 8-OHdG. In the DEX-treated groups, particularly at the 200 µg/kg dose, significant improvements were noted in these parameters. It was determined that the histological architecture was largely preserved, oxidative stress was reduced, and apoptosis was suppressed. Conclusion: The findings suggest that DEX may effectively reduce X-ray-induced small intestinal injury in a dose-dependent manner, and that this effect is mediated through antioxidant and anti-apoptotic mechanisms. DEX holds potential for the prevention or treatment of radiation-induced gastrointestinal toxicities. Full article

Exposure to ionising radiation may be hazardous to living beings, including humans. Ionising radiation exposure has been shown to cause hepatic dysfunction or even liver cancer in persons receiving radiation therapy who do not have liver disease. Changes in hepatic enzyme values may suggest radiation-induced stress on liver cells. Then this experimental study examined the effect of different doses of radiation on the liver enzymes aspartate aminotransferase (AST), alkaline phosphatase (ALP), and alanine aminotransferase (ALT). Methods: Six equal groups of thirty-six New Zealand white rabbits weighing 3 and 5 kg each were formed. The rabbits received total body radiation doses of 0 Gy (Control group), 0.053 Gy, 0.11 Gy, 0.21 Gy, 0.42 Gy, and 0.84 Gy on days, 1, 3, and 5 and week 1, week 2, week 3, and week 4. Generalised Linear Mixed Models (GLMMs) were used to compare the data statistically. Results: There was a significant rise in the serum liver enzyme levels; aspartate aminotransferase (AST), alkaline phosphatase (ALP), and alanine aminotransferase (ALT) all showed a statistically significant time effect after the application of different radiation doses. Based on the group effect of radiation, AST and ALP, but not ALT, showed statistically significant findings. Full article

In our previous study, adipose-derived stem cells (ASCs) cultured in a three-dimensional (3D) organotypic system exhibited mesenchymal-to-epithelial transition (MET) features, including cobblestone morphology and increased expression of E-cadherin and CK18. In this study, we investigated whether ionizing radiation could reverse this phenotype via epithelial–mesenchymal transition (EMT) and examined the involvement of Notch signaling. Mouse ASCs were cultured in Matrigel-based 3D organotypic conditions and exposed to 8 Gy of γ-radiation, and EMT- and Notch-related gene and protein expression were assessed 96 h post-irradiation using ATP viability assays, RT-qPCR, and Western blotting. Exposure to 8 Gy significantly reduced cell viability in 2D ASCs to 49.50 ± 6.50% compared with 61.02 ± 5.77% in 3D organoids (p < 0.0001). Irradiated 3D organoids showed EMT-like changes, including an increase of ~2.5-fold in fibronectin and an increase of ~2.0-fold in Twist1 expression, while epithelial CK18 was modestly elevated. Notch signaling was concurrently activated, with Notch1 and Jagged1 increasing by more than twofold and Fra-1 being significantly upregulated. Pretreatment with 20 μM of the γ-secretase inhibitor (GSI) kept cell viability above 90% and suppressed radiation-induced fibronectin, Twist1, Notch1, and Jagged1 expression. These findings indicate that ionizing radiation promotes EMT in 3D-cultured ASCs and reverses prior epithelialization, with Notch signaling playing a key regulatory role. The 3D ASC organoid model may thus provide a physiologically relevant platform for investigating radiation-induced plasticity and potential antifibrotic interventions. Full article

This study aims to evaluate the effects of total ionizing dose (TID) radiation on the performance of n−MOSFET current mirrors. We propose an ovel experimental approach to analyze the interaction between charge trapping in the MOSFET gate oxide and the resulting current mirror degradation by subjecting devices to TID doses from 50 krad(Si) to 300 krad(Si) using a 60Co gamma source Experimental data show that threshold voltage shifts by up to 1.31 V and transconductance increases by 27%. This degradation leads to this a reduction of more than 10% in current mirror output accuracy occurs at the highest dose. These quantitative criteria establish a clear benchmark for assessing the impact of TID on current mirror performance. These effects are attributed to positive charge trapping in the gate oxide and at the Si–SiO₂ interface induced by ionizing radiation. This study focuses exclusively on radiation effects; electrical stress phenomena such as over−voltage or electrostatic discharge (ESD) are not addressed. The results highlight the critical importance of accounting for TID effects when designing high−performance n−MOSFET current mirrors for radiation−hardened applications. Full article

In the paper we consider the pulsed disturbances caused in the ionosphere by an extreme G5-level geomagnetic superstorm on 10 May 2024, and by the X1.0 and M-class solar flares on 8 May 2024, which preceded the storm. Particular attention is paid to the short-term delays and the sequence of disturbance appearance in the ionosphere and geomagnetic field during these extreme events. The results of a continuous Doppler sounding of the ionosphere on an inclined radio path with a sampling frequency of 25 Hz were used, as well as the data of a ground-based mid-latitude fluxgate magnetometer LEMI-008, and an induction magnetometer IMS-008, which operated with a sampling frequency of 66.6 Hz. Ionization of the ionosphere by the intense X-ray and extreme ultraviolet radiation of solar flares was accompanied by the equally sudden and similarly timed disturbances in the Doppler frequency shift (DFS) of the ionospheric signal, which had an amplitude of 2.0–5.8 Hz. The largest pulsed burst in DFS was registered 68 s after an X1.0 flare on 8 May 2024 at the time when the change of the X-ray flux was at its maximum. Following onto the effect in the ionosphere, a disturbance in the geomagnetic field appeared with a time delay of 35 s. This disturbance is a secondary one that arose as a consequence of the ionosphere response to the solar flare. It was likely driven by the contribution of ionospheric currents and electric fields, which modified the Earth’s magnetic field. On 10 May 2024, a G5-level geomagnetic superstorm with a sudden commencement triggered an impulsive reaction in the ionosphere. A response in DFS at the calculated reflection altitude of the sounding radio wave of 267.5 km was detected 58 s after the commencement of the storm. The sudden impulsive changes in Doppler frequencies showed a bipolar character, reflecting complex dynamic transformations in the ionosphere at the geomagnetic storm. Consequently, the DFS amplitude initially rose to 5.5 Hz over 86 s, and then its sharp drop to $-3.2$ Hz followed. Using the instruments that operated in a mode with a high temporal resolution allowed us to identify for the first time the impulsive nature of the ionospheric reaction, the time delays, and the sequence of disturbance appearances in the ionosphere and geomagnetic field in response to the X1.0 solar flare on 8 May 2024 as well as to the sudden commencement of the extreme G5-level geomagnetic storm on 10 May 2024. Full article

During the clinical use of photobiomodulation (PBM) to manage radiotherapy-induced side effects, tumor tissue may be exposed to low-intensity laser light. Therefore, it is necessary to evaluate potential unintended PBM stimulation of tumor cells when PBM combines with ionizing radiation (IR). We investigated the effects of PBM (0.3 J/cm²) on the cell cycle, mitochondrial potential, and cell death of HeLa Kyoto cells, comparing pre-irradiation (PBM→IR) and post-irradiation (IR→PBM) exposure to 2 Gy, 4 Gy, and 6 Gy of ionizing radiation. PBM prior to IR induced the radiation-induced arrest in the G₂/M phase of the cell cycle. PBM after IR resulted in a partial release of cells from the radiation-induced arrest in the G₀/G₁ phase, along with a decrease in the number of apoptotic cells and cells with depolarized mitochondrial membranes compared to samples treated with IR only. These findings provide a basis for further research into PBM timing to improve radiotherapy outcomes. Full article

Hypoxia-induced radioresistance in non-small cell lung cancer (NSCLC) hinders radiotherapy efficacy. Fractionated schedules exploit reoxygenation between fractions to reverse this resistance, but the effects of post-irradiation reoxygenation remain unclear and may depend on radiation quality. We investigated survival, cell cycle progression, cytokine secretion, and gene expression in hypoxic (1 % O₂) and reoxygenated A549 cells irradiated with X-rays or carbon ions. Colony-forming assays revealed an Oxygen Enhancement Ratio (OER) > 1 for both hypoxic and reoxygenated cells after X-rays, indicating persistent radioresistance; carbon ion OER ≈ 1 reflected oxygen-independent cytotoxicity. Hypoxia weakened radiation-induced G₂ arrest, and this was unaffected by reoxygenation. IL-6 secretion increased after X-rays and IL-8 after carbon ions exposure; both were enhanced under hypoxia and reoxygenation. RNA sequencing revealed that hypoxia induced a pro-survival, epithelial-to-mesenchymal transition (EMT)-promoting, and immune-evasive transcriptional program, which was largely reversed by reoxygenation but without increased clonogenic killing. These findings indicate that short-term reoxygenation after irradiation can normalize hypoxia-driven transcriptional changes yet does not restore radiosensitivity, supporting the advantage of high-linear energy transfer (LET) carbon ions for targeting resistant hypoxic NSCLC cells. Full article

Oral squamous cell carcinoma (SCC) is typically found in middle-aged or elderly individuals, is more common in men than women, can occur at any mucosal site, and is associated with a poor prognosis. The primary risk factors for oral SCC include the use of tobacco, betel nut, or areca nut, and excessive alcohol consumption. A comprehensive management plan for oral SCC typically involves a multidisciplinary team approach with surgery being the primary treatment approach, with or without radiotherapy. Radiotherapy is an essential component in the management of oral SCC, with its application guided by both tumour- and patient-related factors. It may be employed as a definitive, adjuvant, or palliative modality, depending on tumour stage, resectability, surgical margins, histopathological characteristics, as well as the patient’s overall health, financial considerations, and personal preferences. Effective radiotherapy for oral SCC inevitably leads to various tissue toxicities, which can vary among patients. These variations are primarily influenced by patient-specific characteristics, tumour-specific factors, and aspects related to the radiotherapy itself. Some of the complications resulting from ionizing radiation (IR) include oral mucositis, facial dermatitis, salivary gland dysfunction, trismus, and osteoradionecrosis, along with their management strategies. Full article