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Nanomaterials (Basel, Switzerland) Jan 2022This paper proposes a new graphene gamma- and beta-radiation sensor with a backend RF ring oscillator transducer employed to convert the change in the graphene...
This paper proposes a new graphene gamma- and beta-radiation sensor with a backend RF ring oscillator transducer employed to convert the change in the graphene resistivity due to ionizing irradiation into a frequency output. The sensor consists of a CVD monolayer of graphene grown on a copper substrate, with an RF ring oscillator readout circuit in which the percentage change in frequency is captured versus the change in radiation dose. The novel integration of the RF oscillator transducer with the graphene monolayer results in high average sensitivity to gamma irradiation up to 3.82 kΩ/kGy, which corresponds to a percentage change in frequency of 7.86% kGy in response to cumulative gamma irradiation ranging from 0 to 1 kGy. The new approach helps to minimize background environmental effects (e.g., due to light and temperature), leading to an insignificant error in the output change in frequency of the order of 0.46% when operated in light versus dark conditions. The uncertainty in readings due to background light was analyzed, and the error in the resistance was found to be of the order of 1.34 Ω, which confirms the high stability and selectivity of the proposed sensor under different background effects. Furthermore, the evolution of the graphene's lattice defect density due to radiation was observed using Raman spectroscopy and SEM, indicating a lattice defect density of up to 1.780 × 10/cm at 1 kGy gamma radiation, confirming the increase in the graphene resistance and proving the graphene's sensitivity. In contrast, the graphene's defect density in response to beta radiation was 0.683 × 10/cm at 3 kGy beta radiation, which is significantly lower than the gamma effects. This can be attributed to the lower p-doping effect caused by beta irradiation in ambient conditions, compared with that caused by gamma irradiation. Morphological analysis was used to verify the evolution of the microstructural defects caused by ionizing irradiation. The proposed sensor monitors the low-to-medium cumulative range of ionizing radiations ranging from 0 to 1 kGy for gamma radiation and 0 to 9 kGy for beta radiation, with high resolution and selectivity, filling the research gap in the study of graphene-based radiation sensors at low-to-medium ionizing radiation doses. This range is essential for the pharmaceutical and food industries, as it spans the minimum range for affecting human health, causing cancer and DNA damage.
PubMed: 35159652
DOI: 10.3390/nano12030305 -
EuroIntervention : Journal of EuroPCR... Oct 2013In small clinical trials, sympathetic renal denervation using radiofrequency (RF) energy shows promise in treating resistant hypertension. However, the RF procedure is...
AIMS
In small clinical trials, sympathetic renal denervation using radiofrequency (RF) energy shows promise in treating resistant hypertension. However, the RF procedure is lengthy and is associated with pain during ablation. Vascular brachytherapy, a proven treatment for in-stent restenosis, has the potential to cause nerve fibrosis. The purpose of the present study was to assess the safety and feasibility of renal artery brachytherapy for sympathetic renal denervation.
METHODS AND RESULTS
A total of 10 normotensive domestic swine underwent vascular brachytherapy to left and right renal arteries using the Beta-Cath 3.5 Fr delivery system at doses of 25 Gy (n=8) and 50 Gy (n=8) at 2 mm from the source centre. These groups were compared to untreated arteries that served as control (n=4). Follow-up obtained at one or two months included angiogram, intravascular ultrasound, and histopathology analysis. The vascular brachytherapy procedure was safe and no apparent angiographic or ultrasound injuries to the vessel were seen. Histology showed a varying degree of thermal injury more pronounced in the 50 Gy group. The majority of examined nerves showed some degree of injury; there was a dose-related effect on nerve injury severity. There were varying degrees of arteriolar changes in the examined sections, with most showing a 2-20% degree of endothelial cell loss.
CONCLUSIONS
This initial feasibility and safety study of renal nerve denervation, mediated by low and intermediate β-radiation dosages, indicates that this approach can cause nerve fibrosis while avoiding significant damage to the renal artery.
Topics: Animals; Beta Particles; Blood Pressure; Brachytherapy; Humans; Renal Artery; Splanchnic Nerves; Sympathectomy
PubMed: 24169134
DOI: 10.4244/EIJV9I6A118 -
Scientific Reports Jan 2021Positron (β) emitting radionuclides have been used for positron emission tomography (PET) imaging in diagnostic medicine since its development in the 1950s. Development...
Positron (β) emitting radionuclides have been used for positron emission tomography (PET) imaging in diagnostic medicine since its development in the 1950s. Development of a fluorinated glucose analog, fluorodeoxyglucose, labelled with a β emitter fluorine-18 (F-FDG), made it possible to image cellular targets with high glycolytic metabolism. These targets include cancer cells based on increased aerobic metabolism due to the Warburg effect, and thus, F-FDG is a staple in nuclear medicine clinics globally. However, due to its attention in the diagnostic setting, the therapeutic potential of β emitters have been overlooked in cancer medicine. Here we show the first in vitro evidence of β emitter cytotoxicity on prostate cancer cell line LNCaP C4-2B when treated with 20 Gy of F. Monte Carlo simulation revealed thermalized positrons (sub-keV) traversing DNA can be lethal due to highly localized energy deposition during the thermalization and annihilation processes. The computed single and double strand breakages were ~ 55% and 117% respectively, when compared to electrons at 400 eV. Our in vitro and in silico data imply an unexplored therapeutic potential for β emitters. These results may also have implications for emerging cancer theranostic strategies, where β emitting radionuclides could be utilized as a therapeutic as well as a diagnostic agent once the challenges in radiation safety and protection after patient administration of a radioactive compound are overcome.
Topics: Beta Particles; Cell Line, Tumor; Electrons; Fluorodeoxyglucose F18; Humans; Male; Positron-Emission Tomography; Prostatic Neoplasms; Radiation Dosage; Radiopharmaceuticals
PubMed: 33510222
DOI: 10.1038/s41598-021-81910-4 -
Dalton Transactions (Cambridge, England... Nov 2007Monoclonal antibodies have become a viable strategy for the delivery of therapeutic, particle emitting radionuclides specifically to tumor cells to either augment... (Review)
Review
Monoclonal antibodies have become a viable strategy for the delivery of therapeutic, particle emitting radionuclides specifically to tumor cells to either augment anti-tumor action of the native antibodies or to solely take advantage of their action as targeting vectors. Proper and rational selection of radionuclide and antibody combinations is critical to making radioimmunotherapy (RIT) a standard therapeutic modality due to the fundamental and significant differences in the emission of either alpha- and beta-particles. The alpha-particle has a short path length (50-80 microm) that is characterized by high linear energy transfer (100 keV microm(-1)). Actively targeted alpha-therapy potentially offers a more specific tumor cell killing action with less collateral damage to the surrounding normal tissues than beta-emitters. These properties make targeted alpha-therapy an appropriate therapy to eliminate minimal residual or micrometastatic disease. RIT using alpha-emitters such as (213)Bi, (211)At, (225)Ac, and others has demonstrated significant activity in both in vitro and in vivo model systems. Limited numbers of clinical trials have progressed to demonstrate safety, feasibility, and therapeutic activity of targeted alpha-therapy, despite having to traverse complex obstacles. Further advances may require more potent isotopes, additional sources and more efficient means of isotope production. Refinements in chelation and/or radiolabeling chemistry combined with rational improvements of isotope delivery, targeting vectors, molecular targets, and identification of appropriate clinical applications remain as active areas of research. Ultimately, randomized trials comparing targeted alpha-therapy combined with integration into existing standards of care treatment regimens will determine the clinical utility of this modality.
Topics: Alpha Particles; Antibodies, Monoclonal; Humans; Neoplasms; Radioimmunotherapy
PubMed: 17992276
DOI: 10.1039/b704726f -
Medicine Jul 2015This study aimed to evaluate dosimetric characteristics based on Monte Carlo (MC) simulations for a proposed beta emitter bioglass 188Re seed for internal radiotherapy... (Meta-Analysis)
Meta-Analysis Review
This study aimed to evaluate dosimetric characteristics based on Monte Carlo (MC) simulations for a proposed beta emitter bioglass 188Re seed for internal radiotherapy applications. The bioactive glass seed has been developed using the sol-gel technique. The simulations were performed for the seed using MC radiation transport code to investigate the dosimetric factors recommended by the AAPM Task Group 60 (TG-60). Dose distributions due to the beta and photon radiation were predicted at different radial distances surrounding the source. The dose rate in water at the reference point was calculated to be 7.43 ± 0.5 cGy/h/μCi. The dosimetric factors consisting of the reference point dose rate, D(r0,θ0), the radial dose function, g(r), the 2-dimensional anisotropy function, F(r,θ), the 1-dimensional anisotropy function, φan(r), and the R90 quantity were estimated and compared with several available beta-emitting sources. The element 188Re incorporated in bioactive glasses produced by the sol-gel technique provides a suitable solution for producing new materials for seed implants applied to brachytherapy applications in prostate and liver cancers treatment. Dose distribution of 188Re seed was greater isotropic than other commercially attainable encapsulated seeds, since it has no end weld to attenuate radiation. The beta radiation-emitting 188Re source provides high doses of local radiation to the tumor tissue and the short range of the beta particles limit damage to the adjacent normal tissue.
Topics: Brachytherapy; Humans; Radioisotopes; Radiometry; Rhenium
PubMed: 26181543
DOI: 10.1097/MD.0000000000001098 -
Journal of Nuclear Medicine : Official... Sep 2017In recent years, new α-particle-, β-particle-, and Auger electron-emitting radiometals-such as Cu, Sc, Ho, Tb, Tb, Pb/Bi, Ac, and Bi-have been produced and evaluated... (Review)
Review
In recent years, new α-particle-, β-particle-, and Auger electron-emitting radiometals-such as Cu, Sc, Ho, Tb, Tb, Pb/Bi, Ac, and Bi-have been produced and evaluated (pre)clinically for therapeutic purposes. In this short review article, the most important routes of production of these radiometals are critically discussed, as are examples of their application in preclinical and clinical studies.
Topics: Alpha Particles; Animals; Beta Particles; Electrons; Humans; Metals; Radiochemistry; Radioisotopes
PubMed: 28864619
DOI: 10.2967/jnumed.116.186825 -
Materials (Basel, Switzerland) Nov 2022The crystals of (Lu,Gd)(Ga,Al)O multicomponent garnets with high density ρ and effective atomic number Z are characterized by high scintillation efficiency and a light...
Scintillation Characteristics of the Single-Crystalline Film and Composite Film-Crystal Scintillators Based on the Ce-Doped (Lu,Gd)(Ga,Al)O Mixed Garnets under Alpha and Beta Particles, and Gamma Ray Excitations.
The crystals of (Lu,Gd)(Ga,Al)O multicomponent garnets with high density ρ and effective atomic number Z are characterized by high scintillation efficiency and a light yield value up to 50,000 ph/MeV. During recent years, single-crystalline films and composite film/crystal scintillators were developed on the basis of these multicomponent garnets. These film/crystal composites are potentially applicable for particle identification by pulse shape discrimination due to the fact that α-particles excite only the film response, γ-radiation excites only the substrate response, and β-particles excite both to some extent. Here, we present new results regarding scintillating properties of selected (Lu,Gd)(Ga,Al)O:Ce single-crystalline films under excitation by alpha and beta particles and gamma ray photons. We conclude that some of studied compositions are indeed suitable for testing in the proposed application, most notably LuGdAlGaO:Ce film on the GAGG:Ce substrate, exhibiting an α-particle-excited light yield of 1790-2720 ph/MeV and significantly different decay curves excited by α- and γ-radiation.
PubMed: 36431411
DOI: 10.3390/ma15227925 -
International Journal of Molecular... Aug 2022Glycogen is an easily accessible source of energy for various processes. In hepatocytes, it can be found in the form of individual molecules (β-particles) and their...
Glycogen is an easily accessible source of energy for various processes. In hepatocytes, it can be found in the form of individual molecules (β-particles) and their agglomerates (α-particles). The glycogen content in hepatocytes depends on the physiological state and can vary due to the size and number of the particles. Using biochemical, cytofluorometric, interferometric and morphometric methods, the number of β-particles in rat hepatocytes was determined after 48 h of fasting at different time intervals after glucose refeeding. It has been shown that after starvation, hepatocytes contain ~1.6 × 10 β-particles. During refeeding, their number of hepatocytes gradually increases and reaches a maximum (~5.9 × 10) at 45 min after glucose administration, but then quickly decreases. The data obtained suggest that in cells there is a continuous synthesis and degradation of particles, and at different stages of life, one or another process predominates. It has been suggested that in the course of glycogenesis, pre-existing β-particles are replaced by those formed de novo. The main contribution to the deposition of glycogen is made by an increase in the glucose residue number in its molecules. The average diameter of β-particles of glycogen during glycogenesis increases from ~11 nm to 21 nm.
Topics: Animals; Fasting; Glucose; Glycogen; Hepatocytes; Liver; Rats; Starvation
PubMed: 36012534
DOI: 10.3390/ijms23169263 -
Journal of Nuclear Medicine : Official... Jul 2018The use of radioactive sources to deliver cytotoxic ionizing radiation to disease sites dates back to the early 20th century, with the discovery of radium and its... (Review)
Review
The use of radioactive sources to deliver cytotoxic ionizing radiation to disease sites dates back to the early 20th century, with the discovery of radium and its physiologic effects. α-emitters are of particular interest in the field of clinical oncology for radiotherapy applications. The first part of this review explored the basic radiochemistry, high cell-killing potency, and availability of α-emitting radionuclides, together with hurdles such as radiolabeling methods and daughter redistribution. The second part of this review will give an overview of the most promising and current uses of α-emitters in preclinical and clinical studies.
Topics: Alpha Particles; Animals; Beta Particles; Humans; Radiochemistry; Translational Research, Biomedical
PubMed: 29496984
DOI: 10.2967/jnumed.117.204651 -
Nuclear Medicine Review. Central &... 2011Isotope therapy is one of the methods used in primary hyperthyroidism. The therapy is based on short-range beta radiation emitted from radioactive iodine. Radioiodine... (Review)
Review
Isotope therapy is one of the methods used in primary hyperthyroidism. The therapy is based on short-range beta radiation emitted from radioactive iodine. Radioiodine administration must always be preceded by pharmacological normalization of thyroid function. Otherwise, post-radiation thyrocyte destruction and thyroid hormones release may lead to hyperthyroidism exacerbation. Indications for radioiodine therapy in Graves-Basedow disease include recurrent hyperthyroidism after thyrostatic treatment or thyroidectomy and side-effects observed during thyrostatic treatment. In toxic nodule, isotope therapy is the first choice therapy. Radioiodine is absorbed only in autonomous nodule. Therefore, it destroys only this area and does not damage the remaining thyroid tissue. In toxic goitre, radioiodine is used mostly in recurrent nodules. Absolute contraindications for radioiodine treatment are pregnancy and lactation. Relative contraindications are thyroid nodules suspected of malignancy and age under 15 years. In patients with thyroid nodules suspected of malignancy, radioiodine treatment may be applied as a preparation for surgery, if thyrostatic drugs are ineffective or contraindicated. In children, radioiodine therapy should be considered in recurrent toxic goitre and when thyrostatic drugs are ineffective. In patients with Graves-Basedow disease and thyroid-associated orbitopathy, radioiodine treatment may increase the inflammatory process and exacerbate the ophthalmological symptoms. However, thyroid-associated orbitopathy cannot be considered as a contraindication for isotope therapy. The potential carcinogenic properties of radioiodine, especially associated with tissues with high iodine uptake (thyroid, salivary glands, stomach, intestine, urinary tract, breast), have not been confirmed.
Topics: Contraindications; Humans; Hyperthyroidism; Iodine Radioisotopes; Radionuclide Imaging
PubMed: 21751169
DOI: No ID Found