Use Of Laser Radiation Research Articles

The use of laser radiation to assess the bowel viability in an experiment

Aims: To investigate the possibility of using laser rays scattering indicators to assess the bowel viability. Methodology: 30 white rats. A loop of the middle part of the small bowel (SB) with the mesentery was ligated in 10 rats. A loop of the middle part of the large bowel (LB) with the mesentery was ligated in 10 rats. The width of the laser rays at wavelengths λ=0.63 and λ=0.4 μm scattering zone (WLRSZ) was measured (in millimeters) on the afferent (AP), efferent (EP) and ligated (LP) parts of the bowel’s walls in the in 6 hours. Sections of bowels were taken for histological examination. The data obtained by measurements in 10 healthy animals were the control. Results: In AP revealed morphological disorders without signs of necrosis, in EP revealed minor changes, in LP revealed necrosis. We used the ratio of the WLRSZ at wavelengths λ=0.63/λ=0.4 μm. Control ratio on SB and LB didn’t differ significantly. AP ratio on SB and LB was not significantly different, but was significantly different from the control. EP ratio on SB and LB was not significantly different and did not differ significantly from the control, but differed significantly from the indicators on the AP. LP ratio indicators on SB and LB was not significantly different, but significantly different from the control, indicators on AP and EP. Conclusion: 1. The ratio of the laser rays at the wavelengths λ=0.63/λ=0.4 μm scattering zone width is statistically significantly different in the bowel parts without deviated viability, with morphological deviations without signs of necrosis, and with necrosis. 2. Ratio indicators > 1.58 units indicate preserved viability, indicators in the range of 1.4-1.35 units indicate morphological deviations without necrosis, indicators < 1.2 units indicate bowel necrosis. 3. The determination of this ratio should be used in patients to assess its informativeness. Aims: To investigate the possibility of using laser rays scattering indicators to assess the bowel viability. Methodology: 30 white rats. A loop of the middle part of the small bowel (SB) with the mesentery was ligated in 10 rats. A loop of the middle part of the large bowel (LB) with the mesentery was ligated in 10 rats. The width of the laser rays at wavelengths λ=0.63 and λ=0.4 μm scattering zone (WLRSZ) was measured (in millimeters) on the afferent (AP), efferent (EP) and ligated (LP) parts of the bowel’s walls in the in 6 hours. Sections of bowels were taken for histological examination. The data obtained by measurements in 10 healthy animals were the control. Results: In AP revealed morphological disorders without signs of necrosis, in EP revealed minor changes, in LP revealed necrosis. We used the ratio of the WLRSZ at wavelengths λ=0.63/λ=0.4 μm. Control ratio on SB and LB didn’t differ significantly. AP ratio on SB and LB was not significantly different, but was significantly different from the control. EP ratio on SB and LB was not significantly different and did not differ significantly from the control, but differed significantly from the indicators on the AP. LP ratio indicators on SB and LB was not significantly different, but significantly different from the control, indicators on AP and EP. Conclusion: 1. The ratio of the laser rays at the wavelengths λ=0.63/λ=0.4 μm scattering zone width is statistically significantly different in the bowel parts without deviated viability, with morphological deviations without signs of necrosis, and with necrosis. 2. Ratio indicators > 1.58 units indicate preserved viability, indicators in the range of 1.4-1.35 units indicate morphological deviations without necrosis, indicators < 1.2 units indicate bowel necrosis. 3. The determination of this ratio should be used in patients to assess its informativeness.

Upravlyaemaya lazernym izlucheniem spin-volnovaya interferentsiya v neregulyarnoy magnonnoy strukture

Using experimental and numerical investigation, we demonstrate laser-controlled propagation and interaction of spin waves in an irregular magnetic structure in the geometry of the Mach–Zehnder interferometer. It is shown that the use of laser radiation for heating one of the interferometer arms leads to controlled interference of a spin-wave signal in the output section. The yttrium–iron garnet film heating under the action of laser radiation is measured experimentally. Using micromagnetic modeling, the evolution of the spin-wave interference pattern under the action of laser heating of one of the interferometer arm is demonstrated. The results of this study ensure a simple solution for developing tunable spin-wave interferometers for the paradigm of the magnonic logics.

Spectroscopy of Testicular Tissues as a Tool for Azoospermia Visualization During Micro-TESE and IVF: a Feasibility Study

Non-obstructive azoospermia observed in 10% of infertile men and 0,6% of all men is the most severe form of male infertility. The histological structure of testicular tissue in patients with non-obstructive azoospermia is heterogeneous and is represented by various disorders of spermatogenesis. The only way to achieve pregnancy in the families of patients with non-obstructive azoospermia is the method of in vitro fertilization with intracellular sperm injection. The most effective method of detecting spermatozoa suitable for in vitro fertilization in testicles is the micro-TESE method. It is based on a subjective visual assessment of tissues and allows detecting spermatozoa in non-obstructive azoospermia only in 38-60% of cases. To increase the effectiveness of micro-TESE, the method used must be objective, high-specific, safe for reproductive cells, and also implemented during the operation in real time. The existing approaches to solving the problem of identifying seminal tubules with preserved spermatogenesis, such as multiphoton microscope, Raman spectroscopy, optical coherence tomography and etc., are either associated with the use of laser radiation with unproven safety or cannot be implemented intraoperatively and operationally. The paper considers the possibility of creating a specialized microsurgical system for intraoperative evaluation of testicular tissues histological structure using the spatial distribution of its spectral characteristics. We proposed to implement such a system based on multispectral imaging of the studied tissues with real-time data processing and displaying the results using augmented reality methods. The reflectance spectrum of testicular tissue with varying degrees of preservation of spermatogenesis in the visible and near infrared spectral ranges was studied. Spectral regions were identified that potentially provide the best differentiation of healthy tissues and tissues with impaired spermatogenesis. The described approach can be implemented intraoperatively and safely and may serve to automate and objectify the diagnosis of testicular tissues in micro-TESE.

Selective Patterned Growth of ZnO Nanoneedle Arrays

Abstract Nanostructured coatings are widely used to improve the sensitivity of various types of sensors by increasing the active surface area compared to smooth films. However, for certain applications (in some cases), it may be necessary to achieve selectivity in the coating process to ensure that nanostructures only form in specific areas leaving interelectrode spaces free of nanostructures. This article discusses several methods for creating intricate ZnO nanostructured patterns, including area selective application of Zn acetate seeds followed by hydrothermal growth, selective thermal decomposition of zinc acetate via laser irradiation followed by hydrothermal growth, and the electrochemical deposition method. These methods enable ZnO nanostructures to grow onto designated surface areas with customised, patterned shapes, and they are rapid, cost-effective, and environmentally benign. The article examines the process of producing a nanostructured coating with a complex shape and discusses several factors that can impact the quality of the final product. These include the influence of the thermocapillary flows and the “coffee stain” effect on the deposition of a seed layer of zinc oxide from an ethanol solution of zinc acetate. Additionally, the study found that using a protective screen during the growth of nanostructures can reduce the occurrence of unintended parasitic structures in areas lacking a seed layer. Overall, the article presents various techniques and strategies to improve the quality of nanostructured coatings. We have proven that the use of laser radiation to create a seed layer does not impact the final morphology of the resulting nanostructures. However, when combined with computer-controlled technology, this approach allows for the creation of intricate patterns made up of micrometre-sized lines which cannot be achieved by using other methods. The article also demonstrates an electrochemical technique for obtaining zinc oxide nano-structures that can selectively coat metal electrodes without requiring a seed layer.

COMPARATIVE ANALYSIS AND SIMULATION OF WELDING MODES DURING THE CONSTRUCTION OF THE MAIN PIPELINE USING AUTOMATED TECHNOLOGIES

In the present work, the technology of laser welding of the circumferential joints of pipes of the main gas pipeline was studied on the basis of the existing certain experience of its application at the facilities of the gas transmission system and an assessment was made of the possibility of using it as an alternative to automatic arc welding during construction and repair and restoration work. An analysis was made of the use of laser radiation for orbital welding of main pipelines, which showed that the use of this technology makes it possible to increase the productivity of the welding process, to obtain more favorable structures in the seam and in the transition zone, and to ensure a high level of mechanical properties and weld density. Temperature and deformation conditions in the zone of the welded joint help to reduce the likelihood of hot and cold cracking.Modeling of a pipeline section with welded joints made by automatic arc welding and laser welding (hereinafter referred to as LS) was carried out. When modeling welded joints, their geometric parameters for the compared welding technologies were taken into account, as well as the area and volume of the deposited metal, which theoretically correspond to natural values. Loads were applied to the pipe section with a welded seam, imitating three types of mechanical tests: tension, compression and bending, which occur in the case of thermal deformations and soil subsidence during pipeline operation.In the course of the study, stresses were determined in the cross section of a welded joint obtained using two welding technologies, which show the level of mechanical properties of the weld. A comparative analysis and evaluation of the operational reliability of the main gas pipeline with welded joints made by modern automated welding technologies has been carried out.

ANALYSIS OF THE EFFECTIVENESS OF USING A LASER PHOTODYNAMIC SYSTEM FOR THE TREATMENT OF CHRONIC APICAL PERIODONTITIS. CLINICAL CASES SERIES

Background/Aim: The objective of study analysis of the effectiveness of using a laser photodynamic system for the treatment of chronic apical periodontitis. Materials and Methods: The study included 66 patients aged 18 to 60 years with a diagnosis of chronic apical periodontitis in whom 90 root canals were treated. The diagnosis was established on the basis of the patient's complaints, clinical and instrumental studies, X-ray data. The patients were divided equally into two groups and underwent endodontic treatment. In the root canals of patients of the first group, disinfection was carried out by the method of photodynamic therapy. Then the canal was obturated with gutta-percha pins and sealer, the tooth was restored. In patients of the 2nd group, after instrumental and medical treatment, the root canals were sealed with a temporary material "Kalasept" (Sweden) based on calcium hydroxide, and the tooth was restored with a temporary glass ionomer cement "Vitremer" (3M ESPE). process of the rarefaction focus. Results: The evaluation of the results of treatment was carried out in terms of 1-14 days, 6 and 12 months after the final filling of the root canals. positive dynamics in a short time was observed in 93.9% of patients. cases in patients of the 1st group and in 72.7% in patients of the 2nd group. Complications arose in patients of the 1st group in 6.1% of cases. In the 2nd group in 27.3% of cases, which is almost 4.5 times more than in the 1st group. When comparing 2 methods of treatment after 6 months, clinical well-being was observed in patients of the 1st group in 96.9% and in the 2nd group in 81.8% of cases. The percentage of complications that occurred was 3.1% in patients of the 1st group and 18.2% in the 2nd group. Complete healing of the focus in the bone tissue was observed in 84.8% of cases in patients of the 1st group and in 66.6% of cases in patients of the 2nd group. Partial healing of the bone tissue focus was observed in 18.1% and 15.1% of cases in the 1st and 2nd groups. Conclusion: The use of laser radiation in preparing the root canal for obturation in the treatment of chronic forms of periodontitis made it possible to reduce the number of complications by almost 1.5 times and accelerate the healing process of the rarefaction focus.

Special Issue “Laser Technologies in Metal-Based Materials”

The first publication, analyzing the prospects for the use of laser radiation, was published under the authorship of the American physicist Arthur Shawlow in November 1960 (Schawlow, A [...]

Endovenous laser coagulation of varicose veins: evolution continues

The article discusses the evolution of the endovenous laser ablation technique for the treatment of varicose vein disease of lower extremities. The history of studies aimed at improving the endovenous laser ablation is provided. The authors described the features of endovenous laser ablation with wavelengths from λ = 0.445 to 1.94 µm, alongside with edge- and radial-emitting working fibers, as well as fibers with radiation absorption at its distal end. The physical and biophysical mechanisms of the most popular to-date method for outpatient treatment of varicose vein disease of lower extremities are reviewed. The propagation process of laser radiation in the scattering medium is described, and the important role of the radiation scattering effect on the depth of its penetration into biological tissues is shown. The processes that take place during endovenous laser ablation are considered. The difference in physical processes that take place during the use of laser radiation mainly absorbed by hemoglobin (hemoglobin-absorbed range) and by water (water-absorbed range) is described. Expedience of simulating the processes that take place during endovenous laser ablation with the use of blood plasma has been substantiated. The blood plasma simulation demonstrated the decisive action of laser-induced boiling on thermal damage to the vein wall, which causes its fibrous transformation. It has been shown that the use of radial-emitting fibres during intense boiling generates steam bubbles around the site of radiation coupling. The contents of such steam bubbles do not absorb radiation, which thus reaches the venous wall, causing its symmetrical thermal damage. The advantages of using water-absorbing radiation with a wavelength of λ = 1.94 µm in conjunction with a radial-emitting fibre have been substantiated.

TISSUE EXPRESSION OF NEURONAL PROTEINS DURING SCIATIC NERVE REGENERATION AND INFLUENCE OF DIFFERENT SPECTRUM LASER RADIATION

Aim: To determine the effect of laser irradiation of different spectrum on the expression of neuronal proteins (GFAP, S100, NSE and NF-L) in the sciatic nerve during its regeneration after crossing and surgical suturing. Materials and methods: The experiment was performed on 60 laboratory rats of the Wistar line (200-250 g) with crossing of the left sciatic nerve and sutur¬ing with an epineural suture end to end 30 minutes after neurotomy. 90 days later, an immunohistochemical study was performed using specific antibodies (Thermo Fisher Scientific; USA). Results: A study of the marker of non-myelin Schwann GFAP cells showed their pronounced activation with germination in nerve thickness and the formation of weaves of processes around regenerated nerve fibers. The number of S-100-positive myelin Schwann cells decreased, the heterogeneity of their color and the loss of processes were determined. It showed a general decrease in the intensity of NSE- and NF-L-positive staining of nerve fibers regenerated after neurotomy, which was less pronounced when irradiated with a laser with a wavelength of 450-480 nm and 520 nm. Conclusions: In general, the use of laser radiation had a positive effect on the repair of nerve fibers after neurotomy. According to the immunohistochemical study of neuromarkers, the effect of laser irradiation of the blue spectrum was the most effective.

Photobiomodulation surgery of the soft palate

The purpose of the work: To familiarize specialist in the field of laser ENT surgery with the stages of the historical development of surgical care for patients with ronchopathy and obstructive sleep apnea syndrome, to evaluate the effectiveness of traditional uvulopalatoplasty metods and to justify the introduction info practice of the use of laser radiation for uvulopalatoplasty and its modifications. To increase the effectiveness of laser uvulopalatoplasty and its application in patients with ronchopathy and obstructive sleep apnea syndrome of any severity, a method of laser sculptural uvulopalatoplasty based on the use of carbon dioxide laser radiation in the "Super pulse" mode with a scanning device is proposed.

Experimental substantiation for the safety of the use of laser radiation with a wavelength of 445±40 nm in dental practice

The aim of the study was to determine the temperature parameters when exposed to the area of the attached keratinized gum by laser irradiation and to compile clinical recommendations based on the data obtained. The study was conducted on laboratory animals (mature male rats of the Wistar breed) in accordance with Russian and international rules for conducting preclinical studies. The temperature of the keratinized gum was determined by contact method using low level laser therapy (LLLT) at a laser irradiation wavelength of 445±40 nm, a power of 0.5 W with a distance from the tip of the light guide to the gum surface of 2.5—3 mm (group I) and 4.5—5 mm (group II). As a result of the study, it was found that when exposed to low level laser irradiation (LLLI) with a wavelength of 445±40 nm and a distance of 4.5—5 mm from the tip of the light guide to the gum surface, the temperature increase of the gum tissues on average is 8.37±0.296°C, which does not exceed the threshold temperature index. Low level laser therapy with these parameters can be recommended for use in dental practice after conducting appropriate clinical studies.

Phase change memory materials and their applications

Over the past 30 years, phase change memory materials based on chalcogenide semiconductors have rapidly developed from laboratory prototypes to materials extensively used as functional layers in various devices. First of all, this concerns compounds of the Ge–Sb–Te system, which can be reasonably considered as full-fledged functional materials. The review presents a current view of the control of properties of phase change memory materials by their chemical and structural modification. Both the existing and prospective applications of these materials are highlighted. The discussion of chemical modification focuses on popular dopants such as bismuth, tin, oxygen and nitrogen and also refractory metals. In the discussion of structural modification, the use of laser radiation is considered in detail. Currently, this is a key trend in increasing the operation speed of devices based on phase change memory materials. Data on the formation of periodic surface structures in these materials are highlighted and it is emphasized that this effect could find application in nanophotonics and optoelectronics in the near future.<br> The bibliography includes 336 references

Trophic Ulcers of the Lower Extremities: Possibilities of Conservative Treatment

The purpose of the study was to evaluate the effectiveness of low-intensity laser radiation in the complex treatment of trophic ulcers of the lower extremities in patients with varicose veins based on objective criteria. Materials and methods. Clinical and histomorphological studies were performed on patients aged 15 to 75 years who were treated for small and medium stage II ulcers on the lower extremities at the Training and Surgical Clinic of the Azerbaijan Medical University and the Central Hospital of the Gazakh region. The criteria for inclusion in the study were men and women of the above mentioned age, and the presence of ulcerative necrotic lesions of the lower extremities. The exclusion criteria were heart failure, systemic diseases, oncological diseases, hormone therapy, and pregnancy. The patients included in the study groups were comparable in age and sex characteristics, the volume of ulcerative lesions of the lower extremities, the duration of the disease and the somatic state. In the main group, in the treatment of trophic ulcers of the lower extremities of small and medium sizes, Venocoryl ointment, low-intensity laser radiation and endovenous laser ablation using a modified ptfe-coated cylindrical light guide were used. The control group included 25 patients, in whose regional treatment only standard retro-specific methods of treatment using endovenous laser ablation were used. The comparison group included 25 patients who underwent endovenous laser ablation and were prescribed Venocoryl ointment. The experimental groups included 21 men and 54 women aged 15 to 75 years. Results and discussion. The rate of healing of trophic ulcerative wounds during the second month after the start of therapy in the main group in patients of the main group was 0.131 ± 0.008 cm2 per day, in the comparison group – 0.125 ± 0.007 cm2; in the control group – 0.072 ± 0.004 cm2 per day. When observing patients for up to 6 months, the following was noted: in the main group, after the application of the laser, it was possible to completely heal the wound defect in 21 patients (84%) in the main group, 17 patients in the comparison group (68%) and 13 patients in the control group (52%). In the course of the research, it was found that in the main group for the first month there is an active process of epithelization and a reduction, against this background, of the ulcer, and, despite the decrease in the rate of reparative processes in this group, the ulcer epithelializes much earlier and faster. Conclusion. The high rate of healing with the use of laser radiation, compared with standard treatment, was maintained throughout the study period

Моделювання умов отримання наноструктур в алюмінієвих сплавах при дії іонізуючого випромінювання

The use of laser radiation as a source of ionizing radiation to obtain nanostructured and submicrostructured layers on aluminum alloys requires the determination of the necessary technological parameters. Therefore, a theoretical study of ionizing radiation on aluminum alloy AK8 was conducted according to the previously proposed model. When choosing the region in the material of the aluminum alloy, where nanostructures can be formed under the action of ionizing radiation, apply different lengths of ions. Because of the theoretical study of the formation of nanostructures in the surface layer of the aluminum alloy AK8, the temperature distribution in the zone of ionizing radiation at different depths of the material was obtained. Temperature fields for different heat flux densities q1 = 106 W/m2 and q2 = 105 W/m2 were also constructed. The obtained temperature fields for heat flux q1 showed that with increasing depth of the material, the temperature decreases from 2480 to 650 K. The values of maximum temperatures on the material surface are slightly higher than necessary to obtain nanostructures at lower depths maximum temperatures decrease to nanostructures can be realized. Simultaneously, under the action of heat flux q2 = 105 W/m2, the maximum surface temperature decreased to values of 1950 K, and at depth it was 550 K. and was equal to 106 K/s at q2. All these confirmed the possibility of creating conditions for the formation of nanostructures. Due to the temperature range obtained from the calculated temperature fields, the depths of the aluminum alloy where nanostructures can be formed were determined. Studies of the effect of laser radiation spot size on the surface of the material on the formation of nanostructures were also conducted, which showed that when exposed to a spot size of 3 · 103 to 10-3 m, the possibility of nanostructures is significantly reduced, while reducing the spot size to 10-4 m leads to a significant increase in the possibility of forming nanostructures. To estimate the possible volume of nanostructures, the dependence of the nanocluster size on the heat flux density in the range from 107 to 1010 W / m2 and its action time in the range from 10-9 to 10-3 s were considered. The dependence of the maximum temperature on the heat flux density and the time of its action is also constructed. All this allows you to choose the technological parameters of laser radiation to obtain nanostructured layers on aluminum alloys, and the ability to determine the size of nanostructures allows you to predict the physical and mechanical characteristics of the surface layers of processing materials. These studies may be of interest to specialists in strengthening the surfaces of aluminum alloys and further studies of nanostructures.

Using laser in the treatment of chronic skin diseases

In most cases, the treatment of skin diseases, especially chronic processes, is a difficult task due to the low effectiveness of the traditional methods of treatment, the emergence of drug resistance, the development of frequent allergic and other adverse reactions. In total, the impact of the above factors has led to the need to find new ways and methods in the treatment of dermatological lesions. Against the background of using ultrasound, cryotherapy and magnetotherapy, good efficiency was also noted as a result of exposure to laser beams. For the first time, the laser began to be used to treat skin diseases about 40 years ago. When laser radiation is applied to the skin, the processes of photostimulation, photothermolysis and photodynamic reactions occur in its layers. Photostimulation processes began to be used to activate wound healing, and photodynamic reactions were used to treat acne vulgaris, vitiligo, psoriasis, urticaria, and lichen planus. At the same time, low-intensity laser radiation is used for therapeutic purposes, and high-intensity laser radiation is used in surgical practice, in particular, for the removal of warts, papillomas, and genital warts. The use of laser radiation in the treatment of skin diseases contributes to the activation of tissue respiration processes, a decrease in the activity of free radicals, and the stabilization of lipid complexes of cell membranes. In general, improvement in the condition after laser therapy is noted in 40–80 % of patients.

EFFECT F INFRARED LASER RADIATION AND AMINO ACID INTAKE ON THE VASCULAR BED ADAPTATION OF THE IN TERMUSCULAR CONNECTIVE TISSUE 158 TO PHYSICAL ACTIVITY

The aim of the study was to analyze the effect of laser irradiation and branched chain amino acids (BCAAs) on the restructuring of the vascular component of m. biceps femoris during systematic swimming training. Material and methods. The experiment was conducted on 25 rats divided into 5 groups: 1) intact control, 2) dynamic control, 3) training with amino acid intake, 4) training with infrared laser exposure, 5) training with laser exposure and amino acid intake. Tissue samples of the biceps femoral muscle were fixed with formalin with further use of classical histological wiring. Morphometric analysis of the digital image of objects was carried out. Results. Exposure of infrared laser radiation, as well as the use of amino acids, contributes to a reliable increase in the area of the vascular bed relative to the area of connective tissue. When the studied factors were combined, statistically significant differences were found with isolated laser or amino acid exposure groups. Conclusions. The intake of amino acids and the use of laser radiation stimulates the increase of vascular bed area during the training cycle

Laser Reconstruction of Spinal Discs Experiments and Clinic

Degenerative disease of the intervertebral discs (DDD) is currently a serious problem facing the world community. The surgical methods and conservative therapy used today, unfortunately, do not stop the pathological process, but serve as a palliative method that temporarily relieves pain and improves the patient’s quality of life. Therefore, at present, there is an active search for new methods of treating DDD. Among new techniques of treatment, biological methods, and minimally invasive surgery, including the use of laser radiation, which, depending on the laser parameters, can cause ablative or modifying effects on the disc tissue, have acquired considerable interest. Here, we analyze a new approach to solving the DDD problem: laser tissue modification. This review of publications is focused on the studies of the physicochemical foundations and clinical applications of a new method of laser reconstruction of intervertebral discs. Thermomechanical action of laser radiation modifies tissue and leads to its regeneration as well as to a long-term restoration of disc functions, elimination of pain and the return of patients to normal life.

ИЗМЕНЕНИЯ ТЕМПЕРАТУРНЫХ ПОЛЕЙ И МИКРОЦИРКУЛЯЦИИ В СТЕНКАХ ПИЛОНИДАЛЬНЫХ КИСТ КОПЧИКОВОЙ ОБЛАСТИ ВО ВРЕМЯ И ПОСЛЕ ЛАЗЕРИНДУЦИРОВАННОЙ ТЕРМОТЕРАПИИ

Introduction. As of today, many options for conservative and surgical treatment of patients with pilonidal cysts have been developed. Our studies on the use of laser radiation in the treatment of epithelial coccygeal passage, which began in 2007, showed its positive clinical effect, which is expressed in a decrease in the number of complications and relapses. The principle of the method is the thermal ablation of the walls of the coccygeal passage with laser radiation. The aim. To study the effect of high-intensity laser radiation on the tissues of pilonidal cyst in patients with epithelial coccygeal passage, in order to improve the results of their treatment. Materials and methods. The study was conducted from 2018 to 2021. The patients were divided into 2 groups depending on the type of surgical treatment. The first group consisted of 124 patients who underwent cyst excision with primary sutures. The second group included 60 patients who underwent laser-induced interstitial thermotherapy. To study microcirculatory changes in the tissues of the pilonidal cyst while doing operational injury, SPECTROTEST (Spectro Analytical Instruments, Germany) spectrometer was used. Results. We have revealed changes in microcirculation and tissue saturation parameters depending on the type of surgical treatment. In the first group, a statistically significant microcirculatory and tissue saturation disorders were found in the walls of postoperative wounds. In the second group, microcirculatory disorders were less pro-nounced, and their normalization occurred much earlier. This indicates the absence of ischemia of the surrounding tissues around the treated area. Temperatures in the walls of pilonidal cysts at laser-induced interstitial thermom-etry vary from 56 to 65 °C, which are the temperatures of destruction of proteins that make up the structure of the cyst walls. On the surface and in the tissues surrounding the cyst, the maximum recorded temperature was 40 °C, and this does not cause protein destruction. Conclusions. High-intensity laser radiation leads to obliteration of the cystic cavity, the formation of scar tissue, the elimination of specific symptoms and the decrease in the risk of recurrence of pilonidal disease, which is confirmed by spectroscopy, thermometry and histological studies.

Estimation of response time of laser complex data processing nodes

The work is devoted to problem of information exchange between elements and devices of a telecommunication network for laser technological complex. The laser complex is a combination of hardware and software designed to carry out operations based on the use of laser radiation. Laser complex structure provides a possibility of remote control through a client-server system built on the basis of TCP/IP protocol. The main requirements for industrial network of the complex are performance and predictability of information delivery time. To solve this problem, a probabilistic model for calculating the numerical characteristics of the distribution of requests timeout for external commands from control/monitoring nodes is proposed.

Laser pyrolyzed organosilazane‐based Al/ZrO2 composite coating on stainless steel: Resulting microstructure and mechanical properties

AbstractProtective ceramic‐based coatings are frequently the most suitable solutions for problems like corrosion and wear. It has been shown that the precursor technology is suitable for the preparation of ceramic coatings by pyrolysis in a furnace. However, the required high temperature for the preparation of the ceramic coatings limits this approach to high temperature‐resistant substrates. A very innovative approach to overcome this restriction is the use of laser radiation as a thermal source for the pyrolysis of the preceramic polymer. In this paper, we report on a coating system, for steel substrates, consisting of a polysilazane (Durazane 2250) bond coat and a hard and dense top‐coat composed of an organosilazane (Durazane 1800) with tetragonal ZrO2 particles and aluminum flakes as fillers pyrolyzed using Nd:YVO4 laser. The aluminum fillers led to a significant increase in absorption of the laser energy leading to the formation of a dense coating with a thickness up to 20 μm and a mainly cellular/columnar‐dendritic microstructure. The microstructure, mechanical, and tribological behaviors of these composite coatings are reported and compared to those of laser pyrolyzed glass/ZrO2‐filled polysilazane‐based coatings reported in the literature.