scholarly journals Новый сценарий кинетики зарядки диэлектриков при облучении электронами средних энергий

2021 ◽  
Vol 63 (4) ◽  
pp. 483
Author(s):  
Э.И. Рау ◽  
А.А. Татаринцев

The goal of this paper is first to critical review the charging phenomena occurring during electron deposition in insulating materials. In this research we focus on the elucidation of the charging kinetics including the effects of the electron emission increasing and the electron-radiation defect creation. In order to avoid some misinterpretation and contradiction of the experimental results we include three fundamental key factors. The first, in the consideration we include the density of the initial (intrinsic) and radiation-induced trapping sites, second, we take into account the role of the primary thermalized electrons in the emission, and third, the charging phenomena in steady-state phase is regulated by the electronic filed, generated during charging.

2017 ◽  
Vol 63 (4) ◽  
pp. 660-665
Author(s):  
Yelena Tyuryaeva

The article is devoted to various aspects of the use of intraluminal brachytherapy (IB) in treatment for esophageal cancer (EC). A critical review of the use of IB as a component of combined radiotherapy/chemoradiotherapy in neoadjuvant treatment regimens, for definitive CRT, as well as in palliative treatment of non-operable tumors of this localization is given. The contradictory data on the effectiveness of brachytherapy with locally distributed, inoperable EC are summarized. A separate section relates to the prospects for incorporating brachytherapy into combined treatment of early esophageal cancer. Carried out analysis testifies to the necessity of standardization of summary and daily doses of irradiation depending on the indications to the IB.


2019 ◽  
Vol 26 (11) ◽  
pp. 800-818
Author(s):  
Zujian Xiong ◽  
Xuejun Li ◽  
Qi Yang

Pituitary Tumor Transforming Gene (PTTG) of human is known as a checkpoint gene in the middle and late stages of mitosis, and is also a proto-oncogene that promotes cell cycle progression. In the nucleus, PTTG works as securin in controlling the mid-term segregation of sister chromatids. Overexpression of PTTG, entering the nucleus with the help of PBF in pituitary adenomas, participates in the regulation of cell cycle, interferes with DNA repair, induces genetic instability, transactivates FGF-2 and VEGF and promotes angiogenesis and tumor invasion. Simultaneously, overexpression of PTTG induces tumor cell senescence through the DNA damage pathway, making pituitary adenoma possessing the potential self-limiting ability. To elucidate the mechanism of PTTG in the regulation of pituitary adenomas, we focus on both the positive and negative function of PTTG and find out key factors interacted with PTTG in pituitary adenomas. Furthermore, we discuss other possible mechanisms correlate with PTTG in pituitary adenoma initiation and development and the potential value of PTTG in clinical treatment.


Author(s):  
Dr. Raghavendra Naik ◽  
Shweta Vekariya ◽  
R. N. Acharya ◽  
Sneha D. Borkar

The concept of Pathya (wholesome diet) is an unique contribution of Ayurveda, which plays an important role in prevention and management of many diseases. “Shakavarga”, a category under dietetics in classical texts of Ayurveda enlisted different vegetables with their properties and indications in different disease conditions. These vegetables can be prescribed as Pathya (wholesome diet) in clinical practice. In the present review, plants described under Shakavarga, indicated as Pathya in different diseases related to Pranavaha Srotas (Respiratory system) were compiled from 15 different Ayurvedic classical texts. Critical analysis of the compiled data reveals that out of 332 vegetables described under Shakavarga, 44 are indicated in respiratory disease like Shvasa (Dyspnoea/Asthma), Kasa (Cough), Peenasa (Chronic rhinitis) and Hikka (Hiccup). Among them, botanical identity of 42 classical plants has been established and maximum number of vegetables belongs to the family cucurbitaceae (10) followed by solanaceae (4). Some of these vegetables have been reported for their various pharmacological activities related to prevention and management of diseases related to Pranavaha Srotas (Respiratory system). These vegetables are reported for their anti-inflammatory (16), antioxidant (14), anti-allergic (6) and antitussive (3) activities. The observed result may be helpful in use of vegetables as Pathya (wholesome diet) and planning further scientific studies about the efficacy of these plants on prevention as well as management of respiratory diseases.


Author(s):  
Sean Platt ◽  
Diva R. Salomao ◽  
Jose Pulido

Abstract Introduction Little has been published about the choroidal vascular changes that occur years after radiation exposure. The aim of this study was to review the histological changes observed in the choroidal vasculature following radiotherapy for uveal melanoma. Methods Records from a single institution were retrospectively reviewed from June 7, 2007 to June 7, 2017; 101 patients with a diagnosis of uveal melanoma that underwent enucleation had their records reviewed. Out of these, a total of 26 eyes had undergone plaque brachytherapy prior to enucleation, which had been performed at a mean time of 7.2 years (range from 0 years to 30 years) after the initial plaque placement. A histopathologic analysis was conducted on all 26 eyes with special emphasis on the choroidal changes. Of these 26 eyes, 18 demonstrated evidence of radiation-induced vasculopathy. Results Of the 18 eyes, 10/18 (55%) had radiation retinopathy and 16/18 (89%) had radiation choroidal vasculopathy. One patient had a phthisical eye, and the choroid could not be evaluated because the characteristics of the vasculature could not be determined. Nine cases had vitreous hemorrhage (50%), all cases had radiation retinopathy, and 8/9 (89%) had radiation choroidopathy. Of the 16 cases with radiation choroidal vasculopathy, 3/16 (19%) had only intratumoral radiation choroidal vasculopathy, 3/16 (19%) had only extratumoral radiation choroidal vasculopathy, and, thus, 10/16 (32%) had both intratumoral and extratumoral radiation choroidal vasculopathy. In patients with radiation choroidal vasculopathy, 2/16 (13%) had hyalinization of the choroidal vessels. Another 3/16 (19%) cases with radiation choroidal vasculopathy had ectatic vessels. The other 11/16 (68%) had evidence of both hyalinization of the choroidal vessels as well as ectatic vessels in the choroid. Histological evidence of radiation retinopathy and choroidopathy were seen in 69% of eyes enucleated after receiving radiation therapy, which, in some cases, also had vitreous hemorrhage. Polypoidal choroidal vasculopathy, choroidal neovascularization, and retinal choroidal anastomoses (RAP-type lesions) were seen in 12 of the 16 eyes (75%). Discussion/Conclusion Irradiation of malignant tumors of the eye causes not only radiation retinopathy but also radiation choroidopathy. The role of radiation choroidopathy in the subsequent visual loss following radiotherapy and the role of anti-VEGF therapy needs to be recognized and distinguished from radiation retinopathy. Our data adds to the prior limited knowledge that radiation affects the choroid and can induce specific phenotypes similar to the clinical spectrum of CNV, PCV, and RAP.


2021 ◽  
Vol 22 (14) ◽  
pp. 7713
Author(s):  
Alyssa Tidmore ◽  
Sucharita M. Dutta ◽  
Arriyam S. Fesshaye ◽  
William K. Russell ◽  
Vania D. Duncan ◽  
...  

Exposure of rodents to <20 cGy Space Radiation (SR) impairs performance in several hippocampus-dependent cognitive tasks, including spatial memory. However, there is considerable inter-individual susceptibility to develop SR-induced spatial memory impairment. In this study, a robust label-free mass spectrometry (MS)-based unbiased proteomic profiling approach was used to characterize the composition of the hippocampal proteome in adult male Wistar rats exposed to 15 cGy of 1 GeV/n 48Ti and their sham counterparts. Unique protein signatures were identified in the hippocampal proteome of: (1) sham rats, (2) Ti-exposed rats, (3) Ti-exposed rats that had sham-like spatial memory performance, and (4) Ti-exposed rats that impaired spatial memory performance. Approximately 14% (159) of the proteins detected in hippocampal proteome of sham rats were not detected in the Ti-exposed rats. We explored the possibility that the loss of the Sham-only proteins may arise as a result of SR-induced changes in protein homeostasis. SR-exposure was associated with a switch towards increased pro-ubiquitination proteins from that seen in Sham. These data suggest that the role of the ubiquitin-proteome system as a determinant of SR-induced neurocognitive deficits needs to be more thoroughly investigated.


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