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Proceedings of the National Academy of... May 2023The brain is assumed to be hypoactive during cardiac arrest. However, animal models of cardiac and respiratory arrest demonstrate a surge of gamma oscillations and...
The brain is assumed to be hypoactive during cardiac arrest. However, animal models of cardiac and respiratory arrest demonstrate a surge of gamma oscillations and functional connectivity. To investigate whether these preclinical findings translate to humans, we analyzed electroencephalogram and electrocardiogram signals in four comatose dying patients before and after the withdrawal of ventilatory support. Two of the four patients exhibited a rapid and marked surge of gamma power, surge of cross-frequency coupling of gamma waves with slower oscillations, and increased interhemispheric functional and directed connectivity in gamma bands. High-frequency oscillations paralleled the activation of beta/gamma cross-frequency coupling within the somatosensory cortices. Importantly, both patients displayed surges of functional and directed connectivity at multiple frequency bands within the posterior cortical "hot zone," a region postulated to be critical for conscious processing. This gamma activity was stimulated by global hypoxia and surged further as cardiac conditions deteriorated in the dying patients. These data demonstrate that the surge of gamma power and connectivity observed in animal models of cardiac arrest can be observed in select patients during the process of dying.
Topics: Animals; Humans; Gamma Rays; Brain; Electroencephalography; Heart Arrest; Heart
PubMed: 37126719
DOI: 10.1073/pnas.2216268120 -
Sensors (Basel, Switzerland) Sep 2022The history of Compton cameras began with the detection of radiation sources originally for applications in astronomy. A Compton camera is a promising γ-ray detector... (Review)
Review
The history of Compton cameras began with the detection of radiation sources originally for applications in astronomy. A Compton camera is a promising γ-ray detector that operates in the wide energy range of a few tens of keV to MeV. The γ-ray detection method of a Compton camera is based on Compton scattering kinematics, which is used to determine the direction and energy of the γ-rays without using a mechanical collimator. Although the Compton camera was originally designed for astrophysical applications, it was later applied in medical imaging as well. Moreover, its application in environmental radiation measurements is also under study. Although a few review papers regarding Compton cameras have been published, they either focus very specifically on the detectors used in such cameras or the particular applications of Compton cameras. Thus, the aim of this paper is to review the features and types of Compton cameras and introduce their applications, associated imaging algorithms, improvement scopes, and their future aspects.
Topics: Algorithms; Diagnostic Imaging; Gamma Rays; Monte Carlo Method
PubMed: 36236474
DOI: 10.3390/s22197374 -
PeerJ 2023Mutation breeding is one of the effective techniques used for improving desired traits such as yield quality and quantity in economic crops. The present study aims to...
Mutation breeding is one of the effective techniques used for improving desired traits such as yield quality and quantity in economic crops. The present study aims to develop oil and protein contents in addition to high yield attributes in soybean using gamma rays as a mutagen. Seeds of the soybean genotypes Giza 21, Giza 22, Giza 82, Giza 83 and 117 were treated with gamma rays doses 50, 100, 200 and 300 Gy. Plants were then scored based on morphological parameters correlated with yield quantity including plant height, seed weight and valuable protein and oil contents. Mutant lines exhibiting the highest yield attributes were selected and used as parents for M2 generation. The M2 progeny was further assessed based on their ability to maintain their yield attributes. Twenty mutant lines were selected and used as M3 lines. The yield parameters inferred a positive effect of gamma irradiation on the collected M3 mutant lines compared to their parental genotypes. 100 Gy of gamma rays gave the highest effect on the number of pods, branches and seeds per plant in addition to protein content, while 200 Gy was more effective in increasing plant height, number of pods per plant, and oil content. Six mutant lines scored the highest yield parameters. Further assessment inferred an inverse relationship between oil and protein content in most of the tested cultivars with high agronomic features. However, four mutant lines recorded high content of oil and protein besides their high seed yield as well, which elect them as potential candidates for large-scale evaluation. The correlation among examined parameters was further confirmed principal component analysis (PCA), which inferred a positive correlation between the number of pods, branches, seeds, and seed weight. Conversely, oil and protein content were inversely correlated in most of yielded mutant lines. Together, those findings introduce novel soybean lines with favorable agronomic traits for the market. In addition, our research sheds light on the value of using gamma rays treatment in enhancing genetic variability in soybean and improving oil, protein contents and seed yield.
Topics: Soybean Oil; Gamma Rays; Plant Breeding; Glycine max; Mutation
PubMed: 38025746
DOI: 10.7717/peerj.16395 -
Cancer Research Aug 2022Radionuclide irradiators (137Cs and 60Co) are commonly used in preclinical studies ranging from cancer therapy to stem cell biology. Amidst concerns of radiological...
UNLABELLED
Radionuclide irradiators (137Cs and 60Co) are commonly used in preclinical studies ranging from cancer therapy to stem cell biology. Amidst concerns of radiological terrorism, there are institutional initiatives to replace radionuclide sources with lower energy X-ray sources. As researchers transition, questions remain regarding whether the biological effects of γ-rays may be recapitulated with orthovoltage X-rays because different energies may induce divergent biological effects. We therefore sought to compare the effects of orthovoltage X-rays with 1-mm Cu or Thoraeus filtration and 137Cs γ-rays using mouse models of acute radiation syndrome. Following whole-body irradiation, 30-day overall survival was assessed, and the lethal dose to provoke 50% mortality within 30-days (LD50) was calculated by logistic regression. LD50 doses were 6.7 Gy, 7.4 Gy, and 8.1 Gy with 1-mm Cu-filtered X-rays, Thoraeus-filtered X-rays, and 137Cs γ-rays, respectively. Comparison of bone marrow, spleen, and intestinal tissue from mice irradiated with equivalent doses indicated that injury was most severe with 1-mm Cu-filtered X-rays, which resulted in the greatest reduction in bone marrow cellularity, hematopoietic stem and progenitor populations, intestinal crypts, and OLFM4+ intestinal stem cells. Thoraeus-filtered X-rays provoked an intermediate phenotype, with 137Cs showing the least damage. This study reveals a dichotomy between physical dose and biological effect as researchers transition to orthovoltage X-rays. With decreasing energy, there is increasing hematopoietic and intestinal injury, necessitating dose reduction to achieve comparable biological effects.
SIGNIFICANCE
Understanding the significance of physical dose delivered using energetically different methods of radiation treatment will aid the transition from radionuclide γ-irradiators to orthovoltage X-irradiators.
Topics: Animals; Cesium Radioisotopes; Gamma Rays; Mice; Whole-Body Irradiation; X-Rays
PubMed: 35919990
DOI: 10.1158/0008-5472.CAN-22-0656 -
Scientific Reports Apr 2021Preliminary study has been made of black human hair, carbon concentration of some 53%, a model in examining the potential of hair of the human head in retrospective and...
Preliminary study has been made of black human hair, carbon concentration of some 53%, a model in examining the potential of hair of the human head in retrospective and emergency biodosimetry applications, also offering effective atomic number near to that of water. The hair samples were exposed to [Formula: see text]Co gamma rays, delivering doses from 0 to 200 Gy. Structural alterations were observed, use being made of Raman and photoluminescence (PL) spectroscopy. Most prominent among the features observed in the first-order Raman spectra are the D and G peaks, appearing at 1370 [Formula: see text] and 1589 [Formula: see text] respectively, the intensity ratio [Formula: see text] indicating dose-dependent defects generation and annealing of structural alterations. The wavelengths of the PL absorption and emission peaks are found to be centred at [Formula: see text] nm and [Formula: see text] nm, respectively. The hair samples mean band gap energy ([Formula: see text]) post-irradiation was found to be [Formula: see text] eV, of the order of a semiconductor and approximately two times the [Formula: see text] of other carbon-rich materials reported via the same methodology.
Topics: Elements; Female; Gamma Rays; Hair; Humans; Luminescence; Spectrometry, X-Ray Emission; Spectrum Analysis, Raman
PubMed: 33846448
DOI: 10.1038/s41598-021-86942-4 -
The Journal of Biological Chemistry Aug 1946
Topics: Gamma Rays; Humans; Proline
PubMed: 21001157
DOI: No ID Found -
Frontiers in Immunology 2022
Topics: Gamma Rays; Vaccine Development
PubMed: 36700215
DOI: 10.3389/fimmu.2022.1075335 -
International Journal of Molecular... Jan 2022Genetic variations are an important source of germplasm diversity, as it provides an allele resource that contributes to the development of new traits for plant...
Genetic variations are an important source of germplasm diversity, as it provides an allele resource that contributes to the development of new traits for plant breeding. Gamma rays have been widely used as a physical agent for mutation creation in plants, and their mutagenic effect has attracted extensive attention. However, few studies are available on the comprehensive mutation profile at both the large-scale phenotype mutation screening and whole-genome mutation scanning. In this study, biological effects on M generation, large-scale phenotype screening in M generation, as well as whole-genome re-sequencing of seven M phenotype-visible lines were carried out to comprehensively evaluate the mutagenic effects of gamma rays on . A total of 417 plants with visible mutated phenotypes were isolated from 20,502 M plants, and the phenotypic mutation frequency of gamma rays was 2.03% in . On average, there were 21.57 single-base substitutions (SBSs) and 11.57 small insertions and deletions (InDels) in each line. Single-base InDels accounts for 66.7% of the small InDels. The genomic mutation frequency was 2.78 × 10/bp/Gy. The ratio of transition/transversion was 1.60, and 64.28% of the C > T events exhibited the pyrimidine dinucleotide sequence; 69.14% of the small InDels were located in the sequence with 1 to 4 bp terminal microhomology that was used for DNA end rejoining, while SBSs were less dependent on terminal microhomology. Nine genes, on average, were predicted to suffer from functional alteration in each re-sequenced line. This indicated that a suitable mutation gene density was an advantage of gamma rays when trying to improve elite materials for one certain or a few traits. These results will aid the full understanding of the mutagenic effects and mechanisms of gamma rays and provide a basis for suitable mutagen selection and parameter design, which can further facilitate the development of more controlled mutagenesis methods for plant mutation breeding.
Topics: Arabidopsis; Gamma Rays; Genome, Plant; Mutation; Mutation Rate; Phenotype; Plant Breeding; Whole Genome Sequencing
PubMed: 35054839
DOI: 10.3390/ijms23020654 -
Human & Experimental Toxicology 2022Although ionizing radiation (IR) has been of immense value to human life due to its involvement in several fields, it doesn't eliminate that exposure to IR results in an...
BACKGROUND
Although ionizing radiation (IR) has been of immense value to human life due to its involvement in several fields, it doesn't eliminate that exposure to IR results in an array of biological consequences, including oxidative stress, inflammation, and death. Thus, this study aimed to explore the curative effect of trans-Resveratrol (t-Res) on hepatic and renal injury in a rat model exposed to single and fractionated doses of γ-rays.
METHODS
Rats exposed to a single dose of IR (6 Gy, as an acute effect) or a fractionated dose of IR (2 Gy/time/3 days, day after day; to imitate a chronic impact) were treated with t-Res. Then, the radio-protective effect of t-Res was investigated via biochemical and histological estimations in the liver and kidney of rats in the different groups.
RESULTS
The data displayed a significant amelioration in biochemical and histological indices in the liver and kidney of rats exposed to IR doses and treated with t-Res. Particularly, t-Res reduced the oxidative stress milieu through decreasing HIF-1α, ROS, and MDA levels associated with increased CAT activity and Nrf-2 gene expression. Also, t-Res improved the inflammatory status via a decrease in TNF-α, NF-κB, SOCS-3, and HSP-70 genes expression linked with elevations in SIRT-1 and P53 genes expression.
CONCLUSION
It could be concluded that t-Res had hepatoprotective and renoprotective effects against the deleterious consequences of γ-rays exposure due to its antioxidant and anti-inflammatory properties.
Topics: Humans; Rats; Animals; Resveratrol; Kidney; Liver; Gamma Rays; Radiation, Ionizing
PubMed: 36458495
DOI: 10.1177/09603271221142817 -
Sensors (Basel, Switzerland) Dec 2022In order to detect special nuclear materials and other radioactive materials in Security and Defense scenarios, normally, a combination of neutron and gamma-ray...
In order to detect special nuclear materials and other radioactive materials in Security and Defense scenarios, normally, a combination of neutron and gamma-ray detection systems is used. In particular, to avoid illicit traffic of special nuclear materials and radioactive sources/materials, radiation portal monitors are placed at seaports to inspect shipping-container cargo. Despite their large volume (high efficiency), these detection systems are expensive, and therefore only a fraction of these containers are inspected. In this work, a novel mobile radiation detection system is presented, based on an EJ-200 plastic scintillator for the detection of gamma rays and beta particles, and a neutron detector EJ-426HD plastic scintillator (with Li) embedded in a compact and modular moderator. The use of silicon photomultipliers in both detectors presented advantages such as lightweight, compactness, and low power consumption. The developed detection system was integrated in a highly maneuverable multirotor. Monte Carlo simulations were validated by laboratory measurements and field tests were performed using real gamma-ray and neutron sources. The detection and localization within one meter was achieved using a maximum likelihood estimation algorithm for Cs sources (4 MBq), as well as the detection of Am-beryllium (1.45 GBq) source placed inside the shipping container.
Topics: Scintillation Counting; Gamma Rays; Neutrons; Radiation Monitoring; Plastics
PubMed: 36616926
DOI: 10.3390/s23010329