Dynamics of the penetration boundaries of solar protons during a strong magnetic storm

The variations in the equatorial penetration boundary of solar protons with E sub p = 0.9 to 8.0 MeV during a strong magnetic storm of April 3 to 5, were analyzed. The dynamics of this boundary is compared with the dynamics of the outer trapping boundary of electrons with E sub e = - 0.3 to 0.6 MeV. The solar-proton penetration and the structure of the real magnetic field are studied. The unique data on the thin structure of development of a magnetospheric substorm were obtained for the first time

Treatment of patients with anterior urethral strictures: the role of perineal urethrostomy

The article reviews the 2000-2020 literature on the use of perineal urethrostomy in the treatment of patients with anterior urethral strictures. Historical issues of the development of urethrostomy techniques are considered. The algorithms to choose the method of treatment of urethral strictures in favor of perineal urethrostomy are highlighted, according to the guidelines of the world's professional urological associations. The performance indicators of perineal urethrostomy were studied considering the age characteristics of the patients, the etiological genesis of the strictures, their length and location, as well as depending on the surgical technique and the follow-up period. Considerable attention is paid to studies devoted to the analysis of the functional results of urethrostomy, as well as the quality of life of patients associated with urination and sexual activity. Data are presented on the incidence of early and late surgical complications, including urethrostomy stenosis, as one of the most common. An analysis of studies evaluating factors that negatively affect the outcome of surgery was carried out. The main reasons for the growing demand for the technique in surgery for complex anterior urethral strictures and the importance of the technique among other treatment methods are discussed

Optical study of oriented double-Se8-ring clusters and luminescent Se2− anions in LTA at extremely high selenium loading density

peer reviewedRecently, LTA-Se(1–8) samples with 1–8 Se atoms per cavity (simplified unit cell, large cavity + sodalite cage) obtained via adsorption at the temperature of ∼450 °C were reported. It was shown that single Se8 or single Se12 ring are formed in the large LTA cavities, Se8/Se12 ring concentration ratio decreasing with an increase in the Se loading density. Contrary, in the present work, using Se vapour adsorption at ∼550 °C, we succeeded in encapsulation of ∼17 Se atoms per cavity (LTA-Se(17)) with a significant increase in the Se8/Se12 concentration ratio manifesting double Se8-ring cluster formation in the most of the LTA large cavities, which is a step towards cluster crystal fabrication. According to our polarization/orientation Raman spectroscopic study of LTA-Se(17) single crystals, the orientations of the Se8 and Se12 appeared to be similar to those in previously investigated LTA-Se(1–8). Importantly, luminescent Se2− anions, oriented along the LTA 4-fold axes and located in the sodalite cages, are detected via Raman polarization/orientation dependencies of LTA-Se(17). Bright Se2− light emission with a maximum at ∼1.56 eV and vibronic structure is observed in the 1.3–1.8 eV spectral range. We show that the anions experience a compression in LTA which is slightly relaxing with a decrease in temperature producing an anomalous Raman band downshift. The compression of Se2− in LTA is weaker/stronger than that in sodalite/cancrinite, luminescence band photon energy depending on its strength. High concentration of regularly arranged Se2− in LTA suggests considering LTA-Se(17) as an important novel light-emitting material

Surgical treatment of extended spongy urethral strictures in men: minimizing the risks of narrowing in the anastomotic zones between the buccal graft and the native urethra using the dorsal inlay technique

Introduction. Currently, the most common method of treating extended urethral strictures is augmentation urethroplasty using oral mucosa grafts. Analysis of the long-term outcomes of this surgery type shows a high incidence of relapses and complications.Purpose of the study. To improve the outcomes of augmentation urethroplasty, in particular the dorsal inlay (Asopa) technique, in patients with extended spongy urethral strictures by minimizing the risk of recurrent strictures.Materials and methods. The study is based on an analysis of the surgery in 90 patients (aged 18-72 years) with extended spongy urethral strictures. Seventy patients (group I) underwent dorsal inlay augmentation urethroplasty according to the Asopa technique, and 20 patients (group II) — according to the author's modified technique. Statistical data analysis was carried out using the SPSS ver.26 software (SPSS Inc. Chicago, IL, USA).Results. A comparative analysis of the course of the early postoperative period showed a lower number of complications in group II patients compared to group I — 20.0% versus 34.3%, respectively. The recurrent strictures were registered for groups I and II in 18.8% and 5.6% of cases 6 months after surgery, respectively. The recurrent urethral narrowing was most often localized in the area of distal anastomosis between the buccal graft and the native urethra in patients from both groups.Conclusion. The modified dorsal inlay augmentation urethroplasty technique developed and implemented in clinical practice by increasing the internal urethral lumen in the areas of proximal and distal anastomosis between the buccal graft and the native spongy urethral body allows minimizing the risks of recurrent urethral narrowing after augmentation urethroplasty

Pathomorphism of buccal grafts used in surgery of extensive bulbar urethral strictures: immunohistochemical analysis

Introduction. The adverse effects of urine on unadapted tissues are known. This is also entirely relevant for buccal grafts used in augmentation urethroplasty, where these effects have not been thoroughly studied so far.Objective. To assess the ongoing pathomorphosis in buccal grafts used for urethral augmentation of extensive strictures in the bulbous region and to evaluate how much urine influences their histological transformation following surgery.Materials & methods. The study included 15 patients with extensive strictures of the bulbous urethra, who underwent a two-stage augmentation urethroplasty with buccal grafts. The grafts pathomorphosis was studied 6 months after the first surgery stage where urethrotomy had been performed with graft augmentation of the dorsal semicircle and the formation of distal and proximal neomeatuses. Natural urination through the latter was restored on days 14 – 20 following the surgery. During the second stage, six months later, urethral tubularisation was performed with two preliminary biopsies of the proximal and distal segments of the grafts implanted in the areas of the neomeatuses formed earlier. The distal area of the graft had no contact with urine, while this contact has occurred in the proximal segment since restoration of natural urination. In biopsy specimens, pathomorphosis of the grafts was studied using immunohistochemical markers: vimentin, clone SRL33; CD34, clone QBEnd/10; MSA HHF-35; СD3, clone LN10; Bcl-2, clone bcl-2\100\D5; CK-HMW 34BE-12.Results. It was found that inflammation was minimal in areas of grafts implanted that had no contact with urine, while in areas where such contact occurred it was verified to be pronounced even 6 months after the operation. On the submucosal level, this was manifested by an uneven arrangement of collagen fibers, a dysplastically developed vascular network, uneven proliferation of the endothelium with swelling and loss of cellular connectivity, in contrast to areas where there was no contact with urine. In such areas, the graft submucosa had a dense collagen framework with organized microvasculature and uniform epithelial surface.Conclusion. The impact of urine on buccal grafts used in augmentation urethroplasty is characterised by the disorganisation of its collagen framework, with a pronounced inflammatory component and the “reactivity” of the epithelial lining to the “toxic agent” that persists even 6 months after surgery. This may underlie the risk of a stenosis relapse in the proximal anastomosis area

INVESTIGATION OF STRUCTURE AND MECHANICAL PROPERTIES EVOLUTION FOR BERYLLIUM FOILS DURING COLD ROLLING AND HEAT TREATMENT USING EBSD ANALYSIS

Investigations of beryllium structure evolution during cold rolling and high-vacuum heat treatment by different regimes were performed in this work using EBSD analysis. It’s established that combination of large total strain at cold rolling and short-term high-vacuum annealings is necessary to beryllium fine-grained microstructure formation in thin foils and the required complex of mechanical properties obtaining. The proportion of crystallites with favorable {0001} type texture grows in foils as total strain at cold rolling increases. This promotes to plastic properties increase due to additional non–basic slip systems activation during deformation.В работе при помощи методов EBSD анализа выполнены исследования эволюции структуры бериллиевых фольг при холодной прокатке и высоковакуумной термической обработке по различным режимам. Установлено, что для формирования мелкозернистой структуры бериллия в тонких фольгах и получения высокого уровня механических свойств необходимо использование больших суммарных деформаций при холодной прокатке в сочетании с кратковременными высоковакуумными отжигами. Увеличение суммарной степени деформации при холодной прокатке приводит к увеличению доли кристаллитов с благоприятной компонентой текстуры в фольге типа {0001}, которая способствует повышению пластических свойств за счет активации дополнительных небазисных систем скольжения при деформации.Работа выполнена при финансовой поддержке гранта Президента Российской Федерации (соглашение № МК–1402.2017.8)

Phase Composition and Microstructure of Ti-Nb Alloy Produced by Selective Laser Melting

The phase composition and microstructure of Ti-Nb alloy produced from composite titanium and niobium powder by selective laser melting (SLM) was studied. Produced monolayered Ti-Nb alloy enhanced the formation of fine-grained and medium-grained zones with homogeneous element composition of 36-38% Nb mass interval. Alloy phase composition responded to [beta]-alloy substrate phase (grain size was 5-7 pm) and non-equilibrium martensite [alpha]"- phase (grain size was 0.1-0.7 [mu]m). [alpha]"-phase grains were found along [beta]-phase grain boundaries and inside grains, including decreased niobium content. Alloy microhardness varied within 4200-5500 MPa

Multi-stage urethroplasy for anterior urethral strictures: objective parameters of long-term efficacy and patient-reported outcomes

Introduction. Multi-stage urethral surgery is used in cases of the most complex urethral strictures. The evaluation of surgical treatment results given by patients is a significant criterion for the efficacy of urethroplasty along with the assessment of urethral patency through instrumental examinations.Objective. To evaluate the long-term efficacy of multistage urethroplasty for complex anterior urethral strictures considering the patients' quality of life and satisfaction with the surgical outcomes.Materials and methods. The study included 73 patients aged 18 – 84 years with anterior urethral strictures who underwent multi-stage urethroplasty in 2010 – 2019. Surgical and functional outcomes of urethroplasty were assessed through general blood and urine tests, physical examination, uroflowmetry, and retrograde urethrography and urethroscopy in case of urinary disorders.  Subjective parameters of treatment efficacy were studied using questionnaires: International Prostate Symptom Score (IPSS); Quality of life (QoL); Patient-reported Outcome Measure for Urethral Stricture Surgery (USS-PROM); Patient Global Impression of Improvement (PGI-I).Results. Recurrent urethral stricture was detected in 19 (26,0%) patients with the average follow-up period being 65 months. Independent urination was restored in 71 (97.3%) cases, including repeated interventions. After surgery, there was a significant increase in urinary flow rate parameters (Q max: 8.1 vs 19.1 ml/s, p < 0.0001; Q ave: 5.5 vs 10.7 ml/s; p = 0.0004), decrease in residual urine volume (62.4 vs 18.6 ml, p < 0.0001), decrease in total IPSS score (18.7 vs 5.7 points; p < 0.0001) and QoL index (4.3 vs 1 .8 points, p < 0.0001). A comparative analysis of preoperative and postoperative USS-PROM questionnaire results demonstrated an improvement in indicators assessing LUTS (12.9 vs 3.4 points; p < 0.0001; 3.6 vs 1.7 points; p < 0.0001), and urination-associated quality of life (2.6 vs 0.6 points; p < 0.0001) and overall health (EQ-5D index: 0.73 vs 0.91 points; p = 0.025; EQ-VAS: 68.0 vs 88.1 points, p = 0.004). Fifty-seven (81.4%) men were “very satisfied” or “satisfied” with the treatment outcomes, while nine (12.9%) respondents noted a moderate effect of residual urinary disorders on the quality of life. Significantly higher satisfaction was observed among cystostomy patients and in cases where repeated interventions were unnecessary.Conclusion. Multi-stage urethroplasty for complex anterior urethral strictures achieves efficacy in 97.3% of cases and is accompanied by high levels of quality of life and patient’s satisfaction during long-term follow-up

Precise measurement of RudsR_{\text{uds}} and RR between 1.84 and 3.72 GeV at the KEDR detector

The present work continues a series of the KEDR measurements of the $R$ value that started in 2010 at the VEPP-4M $e^+e^-$ collider. By combining new data with our previous results in this energy range we measured the values of $R_{\text{uds}}$ and $R$ at nine center-of-mass energies between 3.08 and 3.72 GeV. The total accuracy is about or better than $2.6\%$ at most of energy points with a systematic uncertainty of about $1.9\%$. Together with the previous precise $R$ measurement at KEDR in the energy range 1.84-3.05 GeV, it constitutes the most detailed high-precision $R$ measurement near the charmonium production threshold.Comment: arXiv admin note: text overlap with arXiv:1610.02827 and substantial text overlap with arXiv:1510.0266