Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 21.508
Filter
1.
Biomaterials ; 313: 122814, 2025 Feb.
Article in English | MEDLINE | ID: mdl-39243672

ABSTRACT

Radiotherapy as a mainstay of in-depth cervical cancer (CC) treatment suffers from its radioresistance. Radiodynamic therapy (RDT) effectively reverses radio-resistance by generating reactive oxygen species (ROS) with deep tissue penetration. However, the photosensitizers stimulated by X-ray have high toxicity and energy attenuation. Therefore, X-ray responsive diselenide-bridged mesoporous silica nanoparticles (DMSNs) are designed, loading X-ray-activated photosensitizer acridine orange (AO) for spot blasting RDT like Trojan-horse against radio-resistance cervical cancer (R-CC). DMSNs can encapsulate a large amount of AO, in the tumor microenvironment (TME), which has a high concentration of hydrogen peroxide, X-ray radiation triggers the cleavage of diselenide bonds, leading to the degradation of DMSNs and the consequent release of AO directly at the tumor site. On the one hand, it solves the problems of rapid drug clearance, adverse distribution, and side effects caused by simple AO treatment. On the other hand, it fully utilizes the advantages of highly penetrating X-ray responsive RDT to enhance radiotherapy sensitivity. This approach results in ROS-induced mitochondria damage, inhibition of DNA damage repair, cell cycle arrest and promotion of cancer cell apoptosis in R-CC. The X-ray responsive DMSNs@AO hold considerable potential in overcoming obstacles for advanced RDT in the treatment of R-CC.


Subject(s)
Nanoparticles , Silicon Dioxide , Humans , Animals , X-Rays , Nanoparticles/chemistry , Female , Silicon Dioxide/chemistry , Mice , Uterine Cervical Neoplasms/therapy , Uterine Cervical Neoplasms/drug therapy , Uterine Cervical Neoplasms/pathology , Reactive Oxygen Species/metabolism , Photosensitizing Agents/pharmacology , Photosensitizing Agents/therapeutic use , Radiation Tolerance/drug effects , Tumor Microenvironment/drug effects , Mice, Nude , HeLa Cells , Mice, Inbred BALB C , Apoptosis/drug effects , Cell Line, Tumor
2.
Nat Commun ; 15(1): 8092, 2024 Sep 16.
Article in English | MEDLINE | ID: mdl-39285181

ABSTRACT

Both copper (Cu2+/+) and iodine (I-) are essential elements in all living organisms. Increasing the intracellular concentrations of Cu or I ions may efficiently inhibit tumor growth. However, efficient delivery of Cu and I ions into tumor cells is still a challenge, as Cu chelation and iodide salts are highly water-soluble and can release in untargeted tissue. Here we report mitochondria-targeted Cu-I cluster nanoparticles using the reaction of Cu+ and I- to form stable bovine serum albumin (BSA) radiation-induced phosphors (Cu-I@BSA). These solve the stability issues of Cu+ and I- ions. Cu-I@BSA exhibit bright radioluminescence, and easily conjugate with the emission-matched photosensitizer and targeting molecule using functional groups on the surface of BSA. Investigations in vitro and in vivo demonstrate that radioluminescence under low-dose X-ray irradiation excites the conjugated photosensitizer to generate singlet oxygen, and combines with the radiosensitization mechanism of the heavy atom of iodine, resulting in efficient tumor inhibition in female mice. Furthermore, our study reveals that BSA protection causes the biodegradable Cu-I clusters to release free Cu and I ions and induce cell death by modulating mitochondrial function, damaging DNA, disrupting the tricarboxylic acid cycle, decreasing ATP generation, amplifying oxidative stress, and boosting the Bcl-2 pathway.


Subject(s)
Copper , Iodides , Mitochondria , Serum Albumin, Bovine , Animals , Copper/chemistry , Mitochondria/drug effects , Mitochondria/metabolism , Mitochondria/radiation effects , Female , X-Rays , Mice , Iodides/chemistry , Iodides/metabolism , Serum Albumin, Bovine/chemistry , Serum Albumin, Bovine/metabolism , Humans , Cell Line, Tumor , Photosensitizing Agents/pharmacology , Mice, Inbred BALB C , Nanoparticles/chemistry , Neoplasms/metabolism , Neoplasms/pathology , Neoplasms/drug therapy , Neoplasms/radiotherapy
3.
Nat Commun ; 15(1): 8240, 2024 Sep 19.
Article in English | MEDLINE | ID: mdl-39300124

ABSTRACT

The poor 5-year survival rate for bladder cancers is associated with the lack of efficient diagnostic and treatment techniques. Despite cystoscopy-assisted photomedicine and external radiation being promising modalities to supplement or replace surgery, they remain invasive or fail to provide real-time navigation. Here, we report non-invasive fractionated photodynamic therapy of bladder cancer with full-course real-time near-infrared-II imaging based on engineered X-ray-activated nanotransducers that contain lanthanide-doped nanoscintillators with concurrent emissions in visible and the second near-infrared regions and conjugated photosensitizers. Following intravesical instillation in mice with carcinogen-induced autochthonous bladder tumours, tumour-homing peptide-labelled nanotransducers realize enhanced tumour regression, robust recurrence inhibition, improved survival rates, and restored immune homeostasis under X-ray irradiation with accompanied near-infrared-II imaging. On-demand fractionated photodynamic therapy with customized doses is further achieved based on quantifiable near-infrared-II imaging signal-to-background ratios. Our study presents a promising non-invasive strategy to confront the current bladder cancer dilemma from diagnosis to treatment and prognosis.


Subject(s)
Photochemotherapy , Photosensitizing Agents , Urinary Bladder Neoplasms , Animals , Urinary Bladder Neoplasms/diagnostic imaging , Urinary Bladder Neoplasms/drug therapy , Urinary Bladder Neoplasms/pathology , Photochemotherapy/methods , Mice , Photosensitizing Agents/therapeutic use , X-Rays , Cell Line, Tumor , Female , Humans , Infrared Rays
4.
Nano Lett ; 24(37): 11690-11696, 2024 Sep 18.
Article in English | MEDLINE | ID: mdl-39225657

ABSTRACT

Precise monitoring of biomolecular radiation damage is crucial for understanding X-ray-induced cell injury and improving the accuracy of clinical radiotherapy. We present the design and performance of lanthanide-DNA-origami nanodosimeters for directly visualizing radiation damage at the single-particle level. Lanthanide ions (Tb3+ or Eu3+) coordinated with DNA origami nanosensors enhance the sensitivity of X-ray irradiation. Atomic force microscopy (AFM) revealed morphological changes in Eu3+-sensitized DNA origami upon X-ray irradiation, indicating damage caused by ionization-generated electrons and free radicals. We further demonstrated the practical applicability of Eu3+-DNA-origami integrated chips in precisely monitoring radiation-mediated cancer radiotherapy. Quantitative results showed consistent trends with flow cytometry and histological examination under comparable X-ray irradiation doses, providing an affordable and user-friendly visualization tool for preclinical applications. These findings provide new insights into the impact of heavy metals on radiation-induced biomolecular damage and pave the way for future research in developing nanoscale radiation sensors for precise clinical radiography.


Subject(s)
DNA , Lanthanoid Series Elements , Microscopy, Atomic Force , DNA/chemistry , DNA/analysis , Humans , Lanthanoid Series Elements/chemistry , X-Rays , DNA Damage , Europium/chemistry
5.
Sensors (Basel) ; 24(17)2024 Sep 05.
Article in English | MEDLINE | ID: mdl-39275686

ABSTRACT

Bone mineral density (BMD) varies with aging and both systemic and local diseases; however, such evidence is lacking in feline medicine. This may be due to the need for general anesthesia in cats for direct BMD measurements using dual-energy X-ray absorptiometry (DXA) or quantitative computed tomography (QCT). In this study, computed digital absorptiometry (CDA), an indirect relative BMD-measuring method, was optimized to select an X-ray tube setting for the quantitative assessment of the feline knee joint. The knee joints of nine cats were radiographically imaged and processed using the CDA method with an aluminum density standard and five X-ray tube settings (from 50 to 80 kV; between 1.2 and 12 mAs). The reference attenuation of the X-ray beam for ten steps (S1-S10) of the density standard was recorded in Hounsfield units (HU), compared between X-ray tube settings, and used to determine the ranges of relative density applied for radiograph decomposition. The relative density decreased (p < 0.0001) with an increase in kV and dispersed with an increase in mAs. Then, the percentage of color pixels (%color pixels), representing ranges of relative density, was compared among S1-S10 and used for the recognition of background artifacts. The %color pixels was the highest for low steps and the lowest for high steps (p < 0.0001), regardless of X-ray tube settings. The X-ray tube setting was considered the most beneficial when it effectively covered the lowest possible HU ranges without inducing background artifacts. In conclusion, for further clinical application of the CDA method for quantitative research on knee joint OA in cats, 60 kV and 1.2 mAs settings are recommended.


Subject(s)
Absorptiometry, Photon , Bone Density , Knee Joint , Animals , Cats , Bone Density/physiology , Absorptiometry, Photon/methods , Knee Joint/diagnostic imaging , Tomography, X-Ray Computed/methods , X-Rays
6.
Int J Mol Sci ; 25(17)2024 Aug 31.
Article in English | MEDLINE | ID: mdl-39273430

ABSTRACT

Recent epidemiological studies have shown that patients with right-sided breast cancer (RBC) treated with X-ray irradiation (IR) are more susceptible to developing cardiovascular diseases, such as arrhythmias, atrial fibrillation, and conduction disturbances after radiotherapy (RT). Our aim was to investigate the mechanisms induced by low to moderate doses of IR and to evaluate changes in the cardiac sympathetic nervous system (CSNS), atrial remodeling, and calcium homeostasis involved in cardiac rhythm. To mimic the RT of the RBC, female C57Bl/6J mice were exposed to X-ray doses ranging from 0.25 to 2 Gy targeting 40% of the top of the heart. At 60 weeks after RI, Doppler ultrasound showed a significant reduction in myocardial strain, ejection fraction, and atrial function, with a significant accumulation of fibrosis in the epicardial layer and apoptosis at 0.5 mGy. Calcium transient protein expression levels, such as RYR2, NAK, Kir2.1, and SERCA2a, increased in the atrium only at 0.5 Gy and 2 Gy at 24 h, and persisted over time. Interestingly, 3D imaging of the cleaned hearts showed an early reduction of CSNS spines and dendrites in the ventricles and a late reorientation of nerve fibers, combined with a decrease in SEMA3a expression levels. Our results showed that local heart IR from 0.25 Gy induced late cardiac and atrial dysfunction and fibrosis development. After IR, ventricular CSNS and calcium transient protein expression levels were rearranged, which affected cardiac contractility. The results are very promising in terms of identifying pro-arrhythmic mechanisms and preventing arrhythmias during RT treatment in patients with RBC.


Subject(s)
Calcium , Mice, Inbred C57BL , Sympathetic Nervous System , Animals , Mice , Sympathetic Nervous System/radiation effects , Sympathetic Nervous System/metabolism , Female , Calcium/metabolism , X-Rays , Heart/radiation effects , Heart/physiopathology , Atrial Remodeling/radiation effects
7.
Rev. Flum. Odontol. (Online) ; 3(65): 65-75, set-dez.2024. ilus
Article in English | LILACS, BBO - Dentistry | ID: biblio-1567853

ABSTRACT

O odontoma é o mais comum tumor odontogênico, definido como malformação benigna, geralmente descoberto na segunda década de vida, durante a investigação de erupção tardia de dentes adjacentes ou retenção prolongada de dentes decíduos. O odontoma é subdividido em composto e complexo. O Odontoma classificado como Composto é constituído por um conjunto de estruturas similares a dentes, de formas e tamanhos diversos, cercados por uma área delgada radiolúcida. Já o Odontoma Complexo se assemelha a uma massa calcificada que apresenta a mesma radiopacidade do tecido dentário, também cercado por uma área delgada radiolúcida. Ocasionalmente, esses dois aspectos podem ser vistos em uma mesma lesão. Frequentemente os odontomas podem provocar um aumento de volume ósseo local devido ao seu desenvolvimento. O diagnóstico é feito através de exames radiográficos de rotina e quando necessário pode-se também lançar mão de Radiografias Panorâmicas e Tomografia Computadorizada Cone Beam com o intuito de verificar sua extensão, as malformações e alterações de erupção causadas aos dentes adjacentes, assim como a classificação do tumor. Este relato de caso apresenta um Odontoma Composto-Complexo em um paciente de 13 anos, do sexo masculino, atendido em 2016 na Clínica de Diagnóstico Bucal II da Universidade Federal Fluminense, que apresentou elementos dentários 22 e 23 impactados, retenção prolongada do elemento 63 e aumento de volume na região anterior do lado esquerdo da maxila. Para obtenção do diagnóstico foram realizadas: Radiografias Periapicais, Radiografia Panorâmica e Tomografia Computadorizada Cone Beam. O objetivo deste trabalho foi elucidar as formas de diagnóstico por imagem que foram utilizadas neste caso clínico e quais as vantagens de cada exame.


Odontomas are the most common type of odontogenic tumors, defined as a benign malformation, usually diagnosed in the second decade of life, during the investigation of late adjacent teeth eruption or a delay in exfoliation of deciduous teeth. They are divided into two types: compound and complex. The odontoma classified as compound is composed of multiple small tooth-like structures, in several shapes and sizes, surrounded by a thin radiolucent rim. On the other hand, complex odontomas resemble a mass of calcified tissue that presents the same dental tissue radiopacity, also surrounded by a thin radiolucent rim. Occasionally, both aspects can be seen in the same lesion. Often, odontomas can cause a local increase in bone volume due to their development. The diagnosis is made through routine radiographic examination and, when it is necessary, it is possible to make use of panoramic radiographies and cone beam computed tomography with the purpose of verifying its extension, malformations and erupted alterations caused to the adjacent teeth, as well as the tumor classification. This case report presents a Compound-Complex Odontoma in a 13-year-old male patient, treated in 2016 at the Oral Diagnosis Clinic II of the Federal Fluminense University. He presented impacted teeth 22 and 23, delayed eruption of tooth 63 and volume increase in the left anterior maxilla site. Aiming the patient's diagnosis, the following exams were necessary: periapical radiographies, panoramic radiography, cone beam computed tomography. The aim of this paper is to explain the different image diagnostic tools which were used in this clinical study and what are the advantages of each exam.


Subject(s)
Humans , Male , Adolescent , Tooth, Impacted , X-Rays , Diagnostic Imaging , Radiography, Panoramic , Odontoma , Cone-Beam Computed Tomography
8.
Nihon Hoshasen Gijutsu Gakkai Zasshi ; 80(9): 944-954, 2024 Sep 20.
Article in Japanese | MEDLINE | ID: mdl-39143013

ABSTRACT

PURPOSE: The purpose of this study was to evaluate the protective performance of several new radiation-protective clothing and to clarify issues of quality control. METHODS: The composition of the shielding elements was analyzed using X-ray fluorescence analysis, and the energy spectrum of transmitted X-rays was measured. Furthermore, the lead equivalent and uniformity were measured from the transmitted X-ray doses according to Japanese industrial standards (JIS). Uniformity was evaluated by transmitting X-ray images of each radiation protective clothing in addition to the conventional method. RESULTS: The energy spectrum showed K-absorption edges of lead, bismuth, tin, etc., which were detected in the composition analysis. The multi-layered protective material maintained higher shielding ability at high tube voltages. In addition, X-ray images of the radiation-protective clothing showed uneven density and dots, and the differences in uniformity measurement methods and points that didn't meet the required shielding capacity were seen. CONCLUSION: The current JIS does not allow accurate evaluation of the lead equivalent and uniformity, so visual evaluation of X-ray images is important. It is necessary to establish standardized standards for quality control performed by each facility.


Subject(s)
Lead , Protective Clothing , Radiation Protection , Protective Clothing/standards , Radiation Protection/instrumentation , Radiation Protection/methods , X-Rays , Quality Control , Spectrometry, X-Ray Emission , Radiation Dosage
9.
J Radiat Res ; 65(5): 591-602, 2024 Sep 24.
Article in English | MEDLINE | ID: mdl-39154379

ABSTRACT

A Monte Carlo simulation was used to assess the performance of a collimated hollow X-ray microbeam for subcellular cytoplasm irradiation. A high-Z coaxial collimation structure with an inner core for nucleus shielding was investigated. Two key performances, the extraction efficiency (cytoplasm dose per unit incident fluence) and the dose contrast (cytoplasm-to-nucleus dose ratio), were evaluated regarding the influences of the material, geometry and physical arrangements of the collimator, target dish and incident beam source. Simulation results demonstrate that a gold coaxial structure with a practical collimation geometry of a 1-mm length, 10-µm inner diameter and 200-µm outer diameter, with the top exit closely attached (with a minimized air gap) to the bottom of a cell dish with a 3-µm thick Mylar film is recommended for cytoplasm irradiation of adherent mammalian cells. For a synchrotron source in the energy range < 10 keV, a dose contrast of approximately 100 can be achieved. For a bremsstrahlung source <30-kV tube voltage, a dose contrast of approximately 50-100 can still be achieved. General principles are summarized with further explanations of the performance of the hollow X-ray microbeam.


Subject(s)
Cytoplasm , Monte Carlo Method , Cytoplasm/radiation effects , X-Rays , Computer Simulation , Humans , Animals
10.
Phys Med Biol ; 69(17)2024 Aug 29.
Article in English | MEDLINE | ID: mdl-39146972

ABSTRACT

Objective.Time-of-flight (TOF) scatter rejection requires a total timing jitter, including the detector timing jitter and the x-ray source's pulses width, of 50 ps or less to mitigate most of the effects of scattered photons in radiography and CT imaging. However, since the total contribution of the source and detector to the timing jitter can be retrieved during an acquisition with nothing between the source and detector, it can be demonstrated that this contribution may be partially removed to improve the image quality.Approach.A scatter correction method using iterative deconvolution of the measured time point-spread function estimates the number of scattered photons detected in each pixel. To evaluate the quality of the estimation, GATE was used to simulate the radiography of a water cylinder with bone inserts, and a head and torso in a system with total timing jitters from 100 ps up to 500 ps full-width-at-half-maximum (FWHM).Main results.With a total timing jitter of 200 ps FWHM, 89% of the contrast degradation caused by scattered photons was recovered in a head and torso radiography, compared to 28% with a simple time threshold method. Corrected images using the estimation have a percent root-mean square error between 2% and 14% in both phantoms with timing jitters from 100 to 500 ps FWHM which is lower than the error achieved with scatter rejection alone at 100 ps FWHM.Significance.TOF x-ray imaging has the potential to mitigate the effects of the scattering contribution and offers an alternative to anti-scatter grids that avoids loss of primary photons. Compare to simple TOF scatter rejection using only a threshold, the deconvolution estimation approach has lower requirements on both the source and detector. These requirements are now within reach of state-of-the-art systems.


Subject(s)
Image Processing, Computer-Assisted , Phantoms, Imaging , Scattering, Radiation , Humans , Image Processing, Computer-Assisted/methods , Time Factors , Photons , Tomography, X-Ray Computed , Head/diagnostic imaging , X-Rays
11.
Phys Med Biol ; 69(17)2024 Aug 30.
Article in English | MEDLINE | ID: mdl-39159669

ABSTRACT

Objective.Proton therapy administers a highly conformal dose to the tumour region, necessitating accurate prediction of the patient's 3D map of proton relative stopping power (RSP) compared to water. This remains challenging due to inaccuracies inherent in single-energy computed tomography (SECT) calibration. Recent advancements in spectral x-ray CT (xCT) and proton CT (pCT) have shown improved RSP estimation compared to traditional SECT methods. This study aims to provide the first comparison of the imaging and RSP estimation performance among dual-energy CT (DECT) and photon-counting CT (PCCT) scanners, and a pCT system prototype.Approach.Two phantoms were scanned with the three systems for their performance characterisation: a plastic phantom, filled with water and containing four plastic inserts and a wood insert, and a heterogeneous biological phantom, containing a formalin-stabilised bovine specimen. RSP maps were generated by converting CT numbers to RSP using a calibration based on low- and high-energy xCT images, while pCT utilised a distance-driven filtered back projection algorithm for RSP reconstruction. Spatial resolution, noise, and RSP accuracy were compared across the resulting images.Main results.All three systems exhibited similar spatial resolution of around 0.54 lp/mm for the plastic phantom. The PCCT images were less noisy than the DECT images at the same dose level. The lowest mean absolute percentage error (MAPE) of RSP,(0.28±0.07)%, was obtained with the pCT system, compared to MAPE values of(0.51±0.08)%and(0.80±0.08)%for the DECT- and PCCT-based methods, respectively. For the biological phantom, the xCT-based methods resulted in higher RSP values in most of the voxels compared to pCT.Significance.The pCT system yielded the most accurate estimation of RSP values for the plastic materials, and was thus used to benchmark the xCT calibration performance on the biological phantom. This study underlined the potential benefits and constraints of utilising such a novelex-vivophantom for inter-centre surveys in future.


Subject(s)
Phantoms, Imaging , Plastics , Protons , Tomography, X-Ray Computed , Image Processing, Computer-Assisted/methods , Animals , Cattle , Calibration , X-Rays
12.
Radiat Prot Dosimetry ; 200(14): 1365-1371, 2024 Sep 10.
Article in English | MEDLINE | ID: mdl-39193892

ABSTRACT

This study aims to provide radiation reference levels in orthopaedic surgery. A total of 753 procedures were collected within 1 y. Categories containing several similar procedures were created based on four criteria: same anatomical area, same level of complexity, only single procedures, and at least 10 cases per category. Exposure was defined in terms of air kerma-area product, fluoroscopy time, and air kerma at the patient entrance reference point. For common procedures, median effective doses to patient were calculated using the Monte Carlo Software PCXMC. Most irradiating procedure in this study i.e. intramedullary nailing of the proximal femur was equivalent to an air kerma at the patient entrance reference point of 37.1 mGy, which is ~50 times lower than the threshold for acute deterministic effects of radiation. Optimization remains a must to reduce the dose while maintaining the image quality and reducing the likelihood of stochastic effects.


Subject(s)
Monte Carlo Method , Radiation Dosage , Humans , Fluoroscopy/methods , Orthopedic Procedures , X-Rays , Male , Female , Adult
13.
Toxins (Basel) ; 16(8)2024 Jul 25.
Article in English | MEDLINE | ID: mdl-39195739

ABSTRACT

Food crops around the world are commonly contaminated with Aspergillus flavus, which can produce the carcinogenic mycotoxin aflatoxin B1 (AFB1). The objective of this study is to test an X-ray irradiation sterilization method for studying AFB1 in contaminated maize samples in the laboratory. Maize that had been naturally contaminated with 300 ppb AFB1 by the growth of aflatoxigenic A. flavus was ground and then irradiated at 0.0, 1.0, 1.5, 2.0, 2.5, and 3.0 kGy. A. flavus was quantified by dilution plating on potato dextrose agar (PDA) and modified Rose Bengal media (MDRB) for viability and qPCR for gene presence. AFB1 was quantified by HPLC and ELISA. A. flavus viability, but not gene copies, significantly decreased with increasing doses of radiation (PDA: p < 0.001; MDRB: p < 0.001; qPCR: p = 0.026). AFB1 concentration did not significantly change with increasing doses of radiation (HPLC: p = 0.153; ELISA: p = 0.567). Our results imply that X-ray irradiation is an effective means of reducing viable A. flavus without affecting AFB1 concentrations. Reducing the hazard of fungal spores and halting AFB1 production at the targeted dose are important steps to safely and reproducibly move forward research on the global mycotoxin challenge.


Subject(s)
Aflatoxin B1 , Aspergillus flavus , Zea mays , Zea mays/microbiology , Zea mays/radiation effects , Aflatoxin B1/radiation effects , Aspergillus flavus/radiation effects , Aspergillus flavus/growth & development , Aspergillus flavus/metabolism , Aspergillus flavus/drug effects , X-Rays , Food Contamination/prevention & control , Food Irradiation/methods , Microbial Viability/radiation effects , Microbial Viability/drug effects
14.
PLoS One ; 19(8): e0307259, 2024.
Article in English | MEDLINE | ID: mdl-39172955

ABSTRACT

BACKGROUND AND AIM: Calibrated pelvic X-ray images are needed in the preoperative planning of total hip arthroplasty (THA) to predict component sizes. Errors and mismatch in the size of one or more components are reported, which can lead to clinically relevant complications. Our aim is to investigate whether we can solve the fundamental problem of X-ray calibration and whether traditional X-ray still has a place in preoperative planning despite improved radiological alternatives. METHODS: Based on geometric and radiographic principles, we estimate that the magnification factor is adapted to the X-ray device and depends strongly on the source-image distance of the device. We analyse the errors of the various calibration methods and investigate which narrow range can be expected to show that the center of rotation is sufficiently accurate. Based on the results of several CT-scans we defined an adapted magnification factor and validated the degree of measurement accuracy. RESULTS: The true magnification of objects on X-ray images depends mainly on the device settings. Stem size prediction is possible to a limited extent, with an error margin of 4.3%. Components can be predicted with a safety margin of one size up and down as with CT or 3D images. The prerequisite is that the source-image distance is greater than or equal to 120 cm, the table-image distance is known, and the object-image distance is estimated according to the patient's BMI. We defined a device-adapted magnification factor that simplifies the templating routine and can be used to obtain the most reliable preoperative dimensional measurements that can be expected from X-ray images. We found the error margin of the magnification factor with the highest degrees of prediction and precision. CONCLUSION: Preoperative planning is reliable and reproducible using X-ray images if calibration is performed with the device-adapted magnification factor suggested in this paper.


Subject(s)
Arthroplasty, Replacement, Hip , Humans , Arthroplasty, Replacement, Hip/methods , Arthroplasty, Replacement, Hip/instrumentation , Calibration , Tomography, X-Ray Computed/methods , Preoperative Care/methods , X-Rays
15.
Appl Radiat Isot ; 212: 111472, 2024 Oct.
Article in English | MEDLINE | ID: mdl-39142226

ABSTRACT

This research focused on the determination of scatter radiation levels in x-ray rooms during chest radiography. 108 patients were examined. Four x-ray machines (A, B, C, and D) were used during the research from three centers. Three positions were considered in this study; position Q just beside the (Bucky stand), position R, which is 150 cm from the left of the Bucky stand towards the door and position T, 200 cm from the Bucky stand to the radiographer's protective screen respectively. Two machines (A and B) from center 1 and one machine from center 2 (C) and one machine from center 3 (D). The body mass index (BMI) of the participants ranged from 20 to 25 kgm-2 with mean value of 23.97 kgm-2. The background radiation level was read using Radalert 100 m before any exposure, and the mean background level was 0.298 mR/h. The mean of the scatter radiation doses obtained from positions Q with respect to the four machines A, B, C, and D, were 0.109, 0.201, 0.204, 0.200 mR/h (9.166, 16.903, 17.156, 16.819 mSv/yr) and their standard deviations were ±0.052, ±0.053, ±0.064, and ±0.081 respectively. The results were comparable with previous studies. The study recommends staff education and training in determination of radiation levels for enhanced work safety.


Subject(s)
Radiation Dosage , Radiography, Thoracic , Scattering, Radiation , Humans , Male , Female , Adult , Middle Aged , Occupational Exposure/analysis , Radiation Protection , X-Rays , Aged
16.
Phys Med Biol ; 69(18)2024 Sep 13.
Article in English | MEDLINE | ID: mdl-39134027

ABSTRACT

Objective.This work explores the enhancement of ionization clustering and its radial dependence around a gold nanoparticle (NP), indicative of the induction of DNA lesions, a potential trigger for cell-death.Approach.Monte Carlo track structure simulations were performed to determine (a) the spectral fluence of incident photons and electrons in water around a gold NP under charged particle equilibrium conditions and (b) the density of ionization clusters produced on average as well as conditional on the occurrence of at least one interaction in the NP using Associated Volume Clustering. Absorbed dose was determined for comparison with a recent benchmark intercomparison. Reported quantities are normalized to primary fluence, allowing to establish a connection to macroscopic dosimetric quantities.Main results.The modification of the electron spectral fluence by the gold NP is minor and mainly occurs at low energies. The net fluence of electrons emitted from the NP is dominated by electrons resulting from photon interactions. Similar to the known dose enhancement, increased ionization clustering is limited to a distance from the NP surface of up to200nm. The number of clusters per energy imparted is increased at distances of up to150nm, and accordingly the enhancement in clustering notably surpasses that of dose enhancement. Smaller NPs cause noticeable peaks in the conditional frequency of clusters between50nm-100nmfrom the NP surface.Significance.This work shows that low energy electrons emitted by NPs lead to an increase of ionization clustering in their vicinity exceeding that of energy imparted. While the electron component of the radiation field plays an important role in determining the background contribution to ionization clustering and energy imparted, the dosimetric effects of NPs are governed by the interplay of secondary electron production by photon interaction and their ability to leave the NP.


Subject(s)
Gold , Metal Nanoparticles , Monte Carlo Method , Gold/chemistry , Metal Nanoparticles/chemistry , X-Rays , Electrons , Photons
17.
Food Res Int ; 192: 114758, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39147491

ABSTRACT

The geographical origin of Panax ginseng significantly influences its nutritional value and chemical composition, which in turn affects its market price. Traditional methods for analyzing these differences are often time-consuming and require substantial quantities of reagents, rendering them inefficient. Therefore, hyperspectral imaging (HSI) in conjunction with X-ray technology were used for the swift and non-destructive traceability of Panax ginseng origin. Initially, outlier samples were effectively rejected by employing a combined isolated forest algorithm and density peak clustering (DPC) algorithm. Subsequently, random forest (RF) and support vector machine (SVM) classification models were constructed using hyperspectral spectral data. These models were further optimized through the application of 72 preprocessing methods and their combinations. Additionally, to enhance the model's performance, four variable screening algorithms were employed: SelectKBest, genetic algorithm (GA), least absolute shrinkage and selection operator (LASSO), and permutation feature importance (PFI). The optimized model, utilizing second derivative, auto scaling, permutation feature importance, and support vector machine (2nd Der-AS-PFI-SVM), achieved a prediction accuracy of 93.4 %, a Kappa value of 0.876, a Brier score of 0.030, an F1 score of 0.932, and an AUC of 0.994 on an independent prediction set. Moreover, the image data (including color information and texture information) extracted from color and X-ray images were used to construct classification models and evaluate their performance. Among them, the SVM model constructed using texture information from X -ray images performed the best, and it achieved a prediction accuracy of 63.0 % on the validation set, with a Brier score of 0.181, an F1 score of 0.518, and an AUC of 0.553. By implementing mid-level fusion and high-level data fusion based on the Stacking strategy, it was found that the model employing a high-level fusion of hyperspectral spectral information and X-ray images texture information significantly outperformed the model using only hyperspectral spectral information. This advanced model attained a prediction accuracy of 95.2 %, a Kappa value of 0.912, a Brier score of 0.027, an F1 score of 0.952, and an AUC of 0.997 on the independent prediction set. In summary, this study not only provides a novel technical path for fast and non-destructive traceability of Panax ginseng origin, but also demonstrates the great potential of the combined application of HSI and X-ray technology in the field of traceability of both medicinal and food products.


Subject(s)
Algorithms , Hyperspectral Imaging , Panax , Support Vector Machine , Panax/classification , Panax/chemistry , Hyperspectral Imaging/methods , Light , X-Rays
18.
Int J Mol Sci ; 25(15)2024 Jul 28.
Article in English | MEDLINE | ID: mdl-39125823

ABSTRACT

The effects of low-dose radiation exposure remain a controversial topic in radiation biology. This study compares early (0.5, 4, 24, 48, and 72 h) and late (5, 10, and 15 cell passages) post-irradiation changes in γH2AX, 53BP1, pATM, and p-p53 (Ser-15) foci, proliferation, autophagy, and senescence in primary fibroblasts exposed to 100 and 2000 mGy X-ray radiation. The results show that exposure to 100 mGy significantly increased γH2AX, 53BP1, and pATM foci only at 0.5 and 4 h post irradiation. There were no changes in p-p53 (Ser-15) foci, proliferation, autophagy, or senescence up to 15 passages post irradiation at the low dose.


Subject(s)
Autophagy , Cell Proliferation , Cellular Senescence , DNA Repair , Fibroblasts , Humans , Fibroblasts/radiation effects , Fibroblasts/metabolism , Autophagy/radiation effects , Cellular Senescence/radiation effects , DNA Repair/radiation effects , X-Rays/adverse effects , Cell Proliferation/radiation effects , Tumor Suppressor p53-Binding Protein 1/metabolism , Histones/metabolism , Dose-Response Relationship, Radiation , Tumor Suppressor Protein p53/metabolism , Tumor Suppressor Protein p53/genetics , Cells, Cultured , DNA Damage/radiation effects
19.
Int J Mol Sci ; 25(15)2024 Aug 02.
Article in English | MEDLINE | ID: mdl-39126012

ABSTRACT

Exposure to ionizing radiation can result in the development of a number of diseases, including cancer, cataracts and neurodegenerative pathologies. Certain occupational groups are exposed to both natural and artificial sources of radiation as a consequence of their professional activities. The development of non-invasive biomarkers to assess the risk of exposure to ionizing radiation for these groups is of great importance. In this context, our objective was to identify epigenetic and molecular biomarkers that could be used to monitor exposure to ionizing radiation. The impact of X-ray exposure on the miRNAs profile and the level of cf mtDNA were evaluated using the RT-PCR method. The levels of pro-inflammatory cytokines in their blood were quantified using the ELISA method. A significant decrease in miR-19a-3p, miR-125b-5p and significant increase in miR-29a-3p was observed in the blood plasma of individuals exposed to X-ray. High levels of pro-inflammatory cytokines and cf mtDNA were also detected. In silico identification of potential targets of these miRNAs was conducted using MIENTURNET. VDAC1 and ALOX5 were identified as possible targets. Our study identified promising biomarkers such as miRNAs and cf mtDNA that showed a dose-dependent effect of X-ray exposure.


Subject(s)
Biomarkers , DNA, Mitochondrial , Epigenesis, Genetic , MicroRNAs , Humans , MicroRNAs/blood , MicroRNAs/genetics , DNA, Mitochondrial/blood , DNA, Mitochondrial/genetics , Epigenesis, Genetic/radiation effects , Biomarkers/blood , X-Rays/adverse effects , Male , Occupational Exposure/adverse effects , Adult , Middle Aged , Cytokines/blood , Cytokines/genetics , Female
20.
Sci Rep ; 14(1): 18007, 2024 08 03.
Article in English | MEDLINE | ID: mdl-39097627

ABSTRACT

Within the scope of this investigation, we carried out experiments to investigate the potential of the Vision Transformer (ViT) in the field of medical image analysis. The diagnosis of osteoporosis through inspection of X-ray radio-images is a substantial classification problem that we were able to address with the assistance of Vision Transformer models. In order to provide a basis for comparison, we conducted a parallel analysis in which we sought to solve the same problem by employing traditional convolutional neural networks (CNNs), which are well-known and commonly used techniques for the solution of image categorization issues. The findings of our research led us to conclude that ViT is capable of achieving superior outcomes compared to CNN. Furthermore, provided that methods have access to a sufficient quantity of training data, the probability increases that both methods arrive at more appropriate solutions to critical issues.


Subject(s)
Neural Networks, Computer , Osteoporosis , Osteoporosis/diagnostic imaging , Humans , X-Rays , Image Processing, Computer-Assisted/methods , Algorithms
SELECTION OF CITATIONS
SEARCH DETAIL