Radiation-Induced Degradation of Organic Compounds and Radiation Technologies for Purification of Aqueous Systems

Environmental application of radiation technologies is an important part of radiation processing. Radiation treatment of aqueous systems contaminated with organic compounds is a promising method of water and wastewater purification and corresponding technologies are being developed. In this chapter, the following aspects of radiation treatment process are considered: sources of contamination and major contaminants of water and wastewater; primary processes in aqueous systems initiated by ionizing radiation; principal ways of contaminant conversion as consequences of primary processes (complete mineralization of organic compounds, partial decomposition of organic molecules resulted in detoxification, decolorization, disinfection of polluted water, and improvement in biological degradation of contaminant, polymerization of monomers’ contaminants, oxidation-reduction processes, and coagulation of colloids); sources of ionizing radiation; and main equipment applied in radiation technologies of aqueous system purification

Numerical Modeling and Clinical Evaluation of Pulsed Dye Laser and Copper Vapor Laser in Skin Vascular Lesions Treatment

Introduction: Different yellow lasers have been successfully used for the treatment of vascular lesions. This study is aimed to ascertain the role and efficiency of copper vapor lasers (CVLs) and pulsed dye lasers (PDLs) for the treatment of vascular lesions using numerical modeling and to compare results with our clinical experience. In this study we aimed to develop criteria for the choice of more efficient laser exposure mode, investigate more relevant modes of laser irradiation to ensure selective photothermolysis of target vessels, and compare the CVL and PDL efficiency in the course of patients with skin vascular lesions (SVL) treatment.Methods: We performed numerical simulation of the processes of heating a vessel with CVL and PDL to temperatures at which its coagulation could occur. Calculated fluencies were compared with clinical results of laser therapy performed on 1242 patients with skin hemangiomas and vascular malformations (SHVM), including 635 patients treated with CVL and 607 patients treated with PDL. PDL and CVL provided excellent results in 40 and ten days after treatment. The treatment was not painful. Patients did not need anesthesia. Postoperative crusts were greater with PDL than with CVL.Results: Results of computer simulation of a selective vessel heating using PDL and CVL radiation are presented. By results obtained, depth of the location and sizes of vessels that could be selectively heated to more than 75°C are determined.Conclusion: Based on calculated and clinical data, the heating mode for dysplastic vessels using a series of CVL micropulses could be regarded to be safer and more efficient than the mode of a PDL short, powerful pulse

Rhinophyma Treatment by Copper Vapor Laser With the Computerized Scanner

Introduction: Rhinophyma is recognized as a common and severe skin disease manifested as progressive thickening of the nasal skin due to hypertrophy of the soft tissue. The most severe complication of rhinophyma is telangiectasis. So far the pathogenetic approach for the treatment of rhinophyma should be based on the removal of the dysplastic vessels to provide the appropriate revascularization of the involved skin area.Case Report: This study presented the experience of the treatment of rhinophyma with the copper vapor laser (CVL) designed with the computerized scanner device. A 52-year-old elderly Caucasian male patient with typical clinical signs of rhinophyma was successfully managed during three sessions of CVL treatment. CVL emits light with a wavelength of 578 nm, exposure time of 0.2 seconds. The settings used for the CVL in scanner mode were set at 1.2 W. The scanner device has a hexagonal frame with a maximum width of 12 mm with the distance of 1 mm between centers of laser spots. The CVL treatment resulted in a restoration of the natural appearance of the nose without side effect during 18 months after treatment.Conclusion: The described clinical case demonstrates excellent results of the management of rhinophyma by means of the scanned CVL. CVL treatment was associated with the removal both of dysplastic superficial skin vessels, the solution of the inflammation, decline of the sebum production and the disappearance of the nasal hypertrophy

Electrospark method for obtaining nanopowders

In the paper, a metallic FexOy nanopowder was obtained by the electrospark method. The used electrospark installation consists of the electrode system, mobility system, system for measuring processing parameters (oscilloscope and current sensor, HV voltage divider, manovacuum meter), source of current pulses, vacuum system (vacuum pump, gas cylinders with working gas, gas routes, gas taps). The specific feature of the installation is the use of a power supply circuit of two generators with different voltage levels operating for one interelectrode gap. This generator circuit makes it possible to change the treatment parameters in wide ranges (pulse duration 10–100 ?s, pulse energy 0.1–0.6 J, pulse repetition rate 0.1–5 kHz). It will enable to choose the optimal ratio between the energy expended and the maximum yield of the product, as well as to study the influence of treatment parameters on the composition and properties of the resulting powder. The morphology and phase composition of the FexOy synthesized metal powder was studied

Treatment of Congenital Melanocytic Nevi With a Dual-Wavelengths Copper Vapor Laser: A Case Series

Introduction: Congenital melanocytic nevus (CMN) is a severe challenge for dermatology. This pigmented skin lesion is undesirable for patients because of its localization in open areas of the body. Various visible and near-infrared laser systems and intense pulsed light (IPL) sources have been applied for CMN treatment. However, post-traumatic hyperpigmentation, structural changes, atrophy, and scarring due to non-specific thermal damage have been observed. Many patients have shown recurrence after treatment. Therefore, it highlights the need for testing new laser modalities for the management of CMN.Methods: Two adult II Fitzpatrick phototype patients (a 55-year-old male and a 30-year-old female) with middle-sized facial CMN (on the forehead and lower eyelid) are presented. All patients were treated with dual-wavelength copper vapor laser (CVL) radiation at 511 nm and 578 nm wavelengths with a power ratio of 3:2. The average power was 0.7-0.85 W with an exposure time of 0.3 seconds. The spot size amounted to 1 mm.Results: Both patients showed complete resolution of CMN after CVL treatments. CMN became crusted within a few days after the laser treatment and peeled off within seven days. No recurrences were observed during the follow-up period up to 24 months.Conclusion: The middle-sized CMN can be successfully treated with dual-wavelength CVL radiation. DOI: 10.34172/jlms.2021.0

Treatment of basal cell cancer with a pulsed copper vapor laser: A Case Series

Introduction: Basal cell carcinoma (BCC) is the most prevalent form of non-melanoma skin cancer commonly arising in elderly patients. Currently, many laser systems are applied for the treatment of BCC. However, up to the present, there have been several reports concerning ocular side effects due to the laser procedure in the borders of the periorbital area. This determines the feasibility of testing new laser surgical modes for the management of periorbital BCC. This stuay aimed to estimate both the efficacy, the early post-radiated side effects and long-term outcomes of the CVL treatment of periorbital BCC.Methods: Two men and 6 women aged 50 to 77 years were diagnosed with periorbital BCC according to the data of both the clinical evaluation and histological examination of the tissue samples taken from the involved area. Six months after the laser treatment, the histological examination of skin samples from the borderline of the irradiated area was made again. All patients were followed for 24 months after the laser treatment of BCC. The laser treatment was administered during one session of copper vapor laser (CVL) (Yakhroma-Med model). The treatment included CVL radiation with a wavelength of 511 nm and 578 nm, in the ratio of 3:2. The power level was set up to 3 W, and the exposure time was equal from 200 to 600 ms. The pulse duration accounted for 15 ns. The diameter of the light spot on the skin surface amounted to 1 mm.Results: Dual-wavelengths CVL treatment of periorbital BCC provided a complete elimination of malignant cells and dysplastic vessels during one procedure. The duration of skin healing amounted to 2-4 weeks. There were neither ocular injuries or pronounced skin side effects nor relapses within 24 months after the laser procedure.Conclusion: CVL treatment of periorbital BCC provides relevant cosmetic results without ocular injuries and relapses