γ radiation
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2022 ◽  
Author(s):  
Aliya A. Gaisina ◽  
Arif A. Mekhtiev ◽  
Afag N. Nurullayeva ◽  
Grigoriy M. Palatnikov ◽  
Elshan N. Shamilov

Abstract High levels of background γ-radiation exist in the suburbs of Baku, Azerbaijan. We examined the impact of radiation on erythrocyte nuclear pathologies, levels of cytochrome P-450, and serotonin-modulating anticonsolidation protein (SMAP) in the tissues of the hens from three settlements with different levels of background radiation. Higher levels of radiation resulted in increased nuclear pathologies, upregulation of tissue SMAP levels, and downregulation of cytochrome P-450.We also carried out controlled dosage studies on Wistar male rats which showed significant upregulation of heat shock proteins with molecular mass 70 kDa (HSP70) in the bone marrow 3 and 5 h later of SMAP intraperitoneal administration. Administration of SMAP to rats 3 h prior to γ-radiation exposure (8 Gy) provided significant protection to somatic cell nuclei. We conclude that SMAP can provide protection from the genotoxic effects of γ-radiation through upregulation of HSP70 or the transformation of chromatin into a condensed, more protective conformational state.


2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Zhiyong Liu ◽  
Jing Liu ◽  
Dan Hu ◽  
Juanjuan Du ◽  
Donglu Liu ◽  
...  

Objective. Radiation-induced heart disease (RIHD) is a common sequela of thoracic irradiation. At the same time, nerve remodeling is involved in the progression of heart disease. However, the activation of the nerve remodeling related genes in radiation-induced heart disease is still lacking. Methods. In this study, C57BL/J mice was anesthetized by intraperitoneal injection with pentobarbital sodium (2%, 40 mg/kg), and radiation was delivered using a cobalt-60 (60Co) teletherapy unit (Cirus). When the mice were anesthetized, none of them showed the signs of peritonitis, pain, or discomfort. The mice hearts were exposed to a γ-radiation field of 5   mm × 5   mm . The total dose of γ-radiation was 3 Gy/day for each animal for 5 consecutive days. The mice were executed by severed neck, and its limbs were weak. Quantitative Polymerase Chain Reaction (qPCR) and immunohistochemistry were used to explore the possible mechanism of arrhythmia in patients with RIHD. Results. Our results demonstrated that Growth-Associated Protein 43 (GAP43) was increased significantly after radioactive heart injury compared with the control group. Moreover, the protein expression of Tyrosine hydroxylase (TH) and Choline acetyl-transferase (CHAT) was significantly decreased compared with the control group and gradually increased with time rend. The nerve growth factor (NGF) was remarkably increased after radiation-induced heart injury compared with the control group. Immunohistochemistry results indicated that the nerve growth factors GAP43 and NGF were significantly increased after radiation-induced heart injury. Conclusions. Chest radiotherapy could activate the neural modeling related genes in RIHD. This may provide a new treatment plan for the future treatment of heart problems caused by chest radiotherapy.


2021 ◽  
Author(s):  
Ihor Fodchuk ◽  
Andrii Kuzmin ◽  
Olena Maslyanchuk ◽  
Ivan Hutsuliak ◽  
Mykola Solodkyi ◽  
...  

Author(s):  
Xue Li ◽  
Juanjuan Yi ◽  
Jiaqing Zhu ◽  
Changcheng Zhao ◽  
Yan Cui ◽  
...  

2021 ◽  
Vol 34 ◽  
pp. 40-47
Author(s):  
D.N. Doikov ◽  
A.V. Yushchenko

The induced γ-ray emissions are considered in contact cataclysmic binary systems with strong magnetic fields near white dwarfs and companion’s stars’ components. He-C-O atoms in white dwarf’s atmospheres collide with flows falling to poles as a magnetic column. Near white dwarf’s surface the falling flows with speed reaches 3 ∙ 10 6  m /s   and creates sufficient conditions for nuclear γ-radiation emission. The cross sections of nuclear γ-radiation emission are presented in 0.1 – 150 MeV energy intervals depending on the colliding atoms and particles. The mass loss from binary components is of the order of   ̇ ≈ (10 −11 − 10 −7 )Msun. We considered the collisions of p – He, α – He, p – C, α – C, p – N, α – N, p – O, α – O, C – He, C – C, C – N, C – O, N – He, N – C, N – N, N – O, O – He, O – C, O – N, and O – O types. Monochromatic energy luminosities Lγ in the above energy intervals for different modes in cataclysmic systems were calculated taking into account the loss of mass M , chemical composition and dynamics of fluxes incident on the magnetic poles. We found the dependencies between   Lγ    and chemical composition and calibrated the synthetic γ-spectra in the above pointed energy intervals. It has been concluded that power flyers are detected from p-p detonation in surface layers in white dwarf’s atmospheres. From calculation we estimated that p-p detonation time scale is in frame of the 0.07-0.1 sec. From which it is concluded that in some surface p-p explosions in the column of the magnetic field are produce significant number of positrons who has a sufficient probability to inject beyond the atmosphere of a white dwarf. It has been shown that the induce γ-ray spectroscopy together with positron spectroscopy are opens new possibilities for diagnostics of the flayers in AM Her polar system. The mechanism of triple detonation, which leads to the explosion of type I supernovae, is proposed. In this context, it is assumed that SN I type explosions occur in white dwarfs with masses not reaching the Chandrasekhar limit. The neutron formation in the matter that are in an explosive state after p-p detonation is considered separately.


Author(s):  
Merlin Behling ◽  
Felix Wezel ◽  
Peter P Pott

Detection of metastasis spread at an early stage of disease in lymph nodes can be achieved by imaging techniques, such as PET and fluoride-marked tumor cells. Intraoperative detection of small metastasis can be problematic especially in minimally invasive surgical settings. A γ-radiation sensor can be inserted in the situs to facilitate intraoperative localization of the lymph nodes. In the minimally invasive setting, the sensor must fit through the trocar and for robot-aided interventions, a small, capsule-like device is favorable. Size reduction could be achieved by using only a few simple electronic parts packed in a single-use sensor-head also leading to a low-cost device. This paper first describes the selection of an appropriate low-cost diode, which is placed in a sensor head (Ø 12 mm) and characterized in a validation experiment. Finally, the sensor and its performance during a detection experiment with nine subjects is evaluated. The subjects had to locate a 137Cs source (138 kBq activity, 612 keV) below a wooden plate seven times. Time to accomplish this task and error rate were recorded and evaluated. The time needed by the subjects to complete each run was 95 ± 68.1 s for the first trial down to 40 ± 23.9 s for the last. All subjects managed to locate the 137Cs source precisely. Further reduction in size and a sterilizable housing are prerequisites for in vitro tests on explanted human lymph nodes and finally in vivo testing.


2021 ◽  
Vol 2086 (1) ◽  
pp. 012136
Author(s):  
D S Dmitrieva ◽  
V V Davydov ◽  
V Y Rud

Abstract The necessity of improving the metrological characteristics and functional capabilities of the fiber-optic sensor for measurements at the large distances (more than 10 km) is substantiated. The new method for constructing a communication line with the fiber-optic sensor for controlling exposure dose in a large range of its variation (several orders of magnitude) in a remote mode is proposed. The functional capabilities of the sensor are determined; its connection setup and measurement limits are developed. The experimental results are presented.


2021 ◽  
Vol 16 (12) ◽  
pp. P12011
Author(s):  
D. Ponomarev ◽  
D. Filosofov ◽  
J. Khushvaktov ◽  
A. Lubashevskiy ◽  
I. Rozova ◽  
...  

Abstract Novel NaIL detector (5 × 6 inch) was investigated for its neutron detection in wide energy range. It has been found that the detector together with its known ability to detect the γ-radiation it also allows to distinguish neutron signals in three quasi-independent ways. It is sensitive to neutron fluxes on a level down to 10-3 cm-2 s-1. In this work intrinsic α-background and neutron detection sensitivity for the NaIL detector were obtained. Experimental data was compared with results of Geant4 Monte Carlo (MC).


Photonics ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 540
Author(s):  
George I. Lambrou ◽  
Anna Tagka ◽  
Athanasios Kotoulas ◽  
Argyro Chatziioannou ◽  
George K. Matsopoulos

The optical properties of biological systems can be measured by imaging and microscopy methodologies. The use of X-rays, γ-radiation and electron microscopy provides information about the contents and functions of the systems. The need to develop imaging methods and analyses to measure these optical properties is increasing. On the other hand, biological samples are easily penetrated by a high-energy input, which has revolutionized the field of tissue optical properties and has now reached a point where light can be applied in the diagnosis and treatment of diseases. To this end, developing methodologies would allow the in-depth study of optical properties of tissues. In the present work, we review the literature focusing on optical properties of biological systems and tissues. We have reviewed the literature for related articles on biological samples’ optical properties. We have reported on the theoretical concepts and the applications of Monte Carlo simulations in the studies of optical properties of biological samples. Optical properties of biological samples are of paramount importance for the understanding of biological samples as well as for their applications in disease diagnosis and therapy.


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