bluuebunny/crossref_metadata_2025 huggingface dataset:
Transformation of fine structure of lamellar pearlite under deformation of rail steel
Authors: Gromov V. E. , Aksenova K. V. , Ivanov Yu. F. , Kuznetsov R. V. , Kormyshev V. E.
Published: March 2023

The defective substructure of polycrystalline bodies causes substructural hardening and mechanical properties. Perlite, which is the main structural component of rails, undergoes a significant transformation during deformation, which is accompanied by a number of processes. In this paper, the methods of modern physical materials science were used to study and analyze the defective substructure of perlite of lamellar morphology and the properties of rail steel subjected to destruction under deformation conditions by single-axis stretching of flat samples. It was established that the ultimate strength varies from 1247 to 1335 MPa, and the relative deformation to failure – from 0.69 to 0.75. The formation of three zones of the fracture surface was observed: fibrous, radial and shear zones. Their shape and sizes were analyzed. Deformation of rail steel is accompanied by destruction of cementite plates of perlite colonies and repeated release of nanoscale particles of tertiary cementite approximately 8.3 nm in size in the volume of ferrite plates. The main mechanisms of destruction of cementite plates are cutting and dissolution. The dislocation substructure is represented by a chaotic distribution of dislocations and their clusters. The scalar density of dislocations in ferrite increases from 3.2·1010 cm–2 in the initial state to 7.9·1010 cm–2 when it is destroyed. Deformation is accompanied by formation of internal stress fields, manifested in the form of bending extinction contours. The sources of stress fields are the interface of cementite and ferrite plates, as well as grain boundaries. Fragmentation of ferrite and cementite plates was revealed. The average size of cementite fragments is 9.3 nm. In fracture zone of the rail steel sample, rotation of perlite grains was noted, indicating the presence of a rotational mode of deformation. Electron microscopic images of cementite plates show a change in the contrast, which may be associated with the formation of Cottrell’s atmospheres.
Formation of grain structure and microhardness of Ni3Al intermetallic compound as a result of SHS extrusion
Authors: Akimov K. O. , Ivanov K. V. , Figurko M. G. , Ovcharenko V. E.
Published: March 2023

In the work the possibility of improving the strength properties of Ni3Al intermetallic compound by reducing its average grain size was studied using the example of microhardness. The authors investigated the effect of reaction mixture deformation during self-propagating high-temperature synthesis (SHS) on the grain size and microhardness of Ni3Al intermetallic compound. SHS extrusion was carried out on the experimental stand, which allows continuous monitoring of synthesis parameters. It was established that one of the key factors affecting the characteristics of the grain structure and microhardness is degree of the synthesis product deformation. An increase in diameter of the extrusion hole from 3 to 5 mm leads to an increase in the maximum linear displacement of the press plunger due to active output of the material through a hole of the larger diameter. The above assumes a decrease in the material resistance to deformation when pressure is applied and an increase in degree of the material deformation inside the die and its decrease in the extruded material. Furthermore, the average grain size of Ni3Al remaining in the mold volume after synthesis decreases by 40 % (from 7 to 5 μm), and the material that passed through the extrusion hole increases by 2 times (from 3 to 6 µm). Compared to Ni3Al obtained by SHS compaction, the average grain size of the extruded intermetallic compound is 5.6 times smaller (from 17 to 3 μm). A decrease in the average grain size of extruded Ni3Al leads to an increase in microhardness by 600 MPa. The results obtained make it possible to develop recommendations for producing intermetallic compounds and alloys based on them with a fine grain size and high microhardness.
Study of pipe steel resistance to deformation in laboratory conditions and on the data from industrial rolling with the use of machine learning tools
Authors: Zinyagin A. G. , Muntin A. V. , Kryuchkova M. O.
Published: March 2023

The study of resistance to deformation of various steel grades is one of the key issues for the adequate operation of automation systems, which makes it possible to obtain rolled products with the required accuracy in terms of geometric characteristics. In addition, knowledge of deformation resistance is important in the design of rolling mill equipment. In the literature, the values ​​of deformation resistance in the overwhelming majority of cases are given in the form of coefficients of various equations (for example, Hensel-Spittel). However, these formulas often have limitations in the range of technological parameters where they give an acceptable result. It should also be considered that dozens of steel grades are produced at modern rolling mills, and their chemical composition can vary over a wide range depending on the final thickness of rolled products, customer requirements, or based on economic considerations (the most advantageous alloying composition). The study of the rheological properties of such a quantity of materials in the laboratory is expensive, long-term, and labor-intensive, and the literature sources do not provide completeness of the data. The article shows that, using data from industrial rolling mills and machine learning methods, it is possible to obtain information about the rheology of the material with satisfactory accuracy, which makes it possible to avoid laboratory studies. Carrying out such studies is possible due to the high saturation of modern rolling mills with various sensors and measuring instruments. Comparison of the results from industrial data was carried out with the values ​​of the deformation resistance obtained on the Gleeble machine. Based on this comparison, the model was trained based on gradient boosting to take into account the features of the technological process in industrial production.
Effect of B2O3 on viscosity of high-magnesia blast furnace slag
Authors: Vusikhis A. S. , Leont’ev L. I. , Gulyaeva R. I. , Sergeeva S. V. , Tyushnyakov S. N.
Published: March 2023

Metallurgical companies in the Urals account for 50 – 60 % of local raw materials. Its deficit is compensated by the use of materials imported from Central Russia, the Kola Peninsula and Kazakhstan. Replacing them with the local raw materials would increase the competitiveness of metal produced in the Urals, so the question of assessing the possibility of replacing imported raw materials with local ones is very relevant. Such raw materials could be siderite ores from the Bakal deposit. They are not in demand by metallurgists because of their low iron content and high magnesium content. With growth of siderites in a charge the magnesium oxide content in slag increases that influences its viscosity and makes it difficult or impossible to smelt using more than 20 % of siderites. The use of boron oxide has been suggested to liquefy the slag. The synthetic slag containing 26.8 % CaO, 38.1 % SiO2 , 11.8 % Al2O3 , 23.6 % MgO, simulating composition of slag from MMK blast-furnace smelting with the addition of 30 % of burnt siderites is short and unstable. The temperature corresponding to the slag viscosity at the blast furnace outlet (0.5 Pa·s) is 1390 °C and the temperature corresponding to the melting point (viscosity 2.5 Pa·s) is 1367 °C. If boric anhydride is added to such a slag, it becomes long and stable. In the melts, when the proportion of B2O3 is increased from 0 to 12 %, the temperature at which the slag viscosity is 0.5 Pa·s and 2.5 Pa·s decreases to 1260 °C, and 1100 °C, respectively. This makes it possible to significantly increase the siderite content in blast furnace charge.
Impact of barium and strontium on calcium recovery level in ladle treatment of steel by complex modifiers with alkaline-earth metals
Authors: Bakin I. V. , Shapovalov A. N. , Kalyaskin A. V. , Kuznetsov M. S.
Published: March 2023

Increasingly rigid requirements in terms of the steel products quality are forcing the technical experts of metallurgical production to look for new solutions to stabilize the steel quality. Much attention is paid to ladle treatment technologies and selection well-minded composition of modifiers, which makes it possible to reduce steel contamination by non-metallic inclusions. To solve this problem, complex modifiers containing both calcium and other alkaline-earth metals (barium and strontium) are used. The paper presents the results of the pilot scale tests of steel ladle treatment by complex modifiers with alkaline-earth metals (Si, Ca, Ba) in steel production with increased requirements to non-metallic inclusions in conditions of electric furnace steelmaking shop of JSC “Ural Steel”. During experimental work it was possible to reduce the maximum contamination score profile rolled steel from pipe steel grades for brittle silicates (GOST 1778) from 4.0 to 1.5 – 2.5, for non-deforming silicates from 4.0 to 3.0 – 3.5. The substitution of SK40 grade silicocalcium for experimental modifiers led to an improvement in the strength properties of rolled products, both in tensile tests and in impact bending tests at low temperatures. The indicated impact was observed in all variants of consumption the experimental master alloys. It is noted that with an increasing in the consumption of master alloys, the positive effect on the steel mechanical properties enhanced. It was established that the replacement of silicocalcium with experimental variants of master alloys made it possible to increase the calcium recovery by an average of 1.6 times when using Si – Ca – Ba, and by an average of 2.4 times when using Si – Ca – Ba – Sr. The use of complex modifiers made it possible to obtain the target value of residual calcium in the sample at significantly lower calcium consumption.
KRİPTO PARA PİYASASINDA VOLATİL DAVRANIŞLARIN ASİMETRİK STOKASTİK VOLATİLİTE MODELİ İLE TESTİ
Authors: GUBADLI Magsud , SARIKOVANLIK Vedat
Published: March 2023

Bu çalışmada, kripto piyasasının önde gelen altı kripto para biriminin (Bitcoin, Stellar, Litecoin, Ethereum, Tether ve Ripple) volatil yapısı, asimetrik ilişki ve/ve ya kaldıraç etkisinin var olup olmadığı test edilmektedir. 09/11/2017-31/07/2022 dönemini kapsayan ve WinBUGS uygulaması ile yapılan bu çalışmada öncelikle logaritmik fark alınarak getiri serisi hesaplanmıştır. Bu kapsamda 100.000 tekrarla örneklem sınaması yapılmış olup katsayıların başlangıç eğiliminden çıkması için tahminlerin ilk 10.000 örneklemi dışlanarak kalan 90.000 örneklemle analiz gerçekleştirilmiştir. Asimetrik stokastik volatilite modeli tahmin sonuçlarına göre kripto para birimlerinin oynaklık kalıcılığı, oynaklığın öngörülebilirliği ve para birimlerinin kendi getirilerinin şoku ile oynaklıklarının etkisi arasındaki korelasyon düzeyi ilgili parametreler ile değerlendirilmiştir. Belirtilen zaman aralığında çalışmamızda kullanılan tüm kripto para birimleri için yoğun bir volatilite kümelenmesi olduğu gözlemlenmiştir. Bu volatilitenin sürekli olduğu ve düşük öngörülebilirliğin varlığı ampirik olarak asimetrik stokastik volatilite modeli ile elde edilen bulgular arasındadır. Ayrıca çalışmanın sonuçlarına göre Ethereum kripto para birimi dışındaki diğer beş para biriminin hiçbirinde ne kaldıraç etkisi ne de asimetrik ilişkisinin hiçbiri gözlemlenmemiştir.
THE CAUSALITY BETWEEN AGRICULTURAL RAW MATERIALS AND ECONOMIC POLICY UNCERTAINTY: EVIDENCE FROM THE TIME-VARYING GRANGER CAUSALITY
Authors: TUNÇ Ahmet , SAVAŞ Savaş , BARAK Doğan
Published: March 2023

This paper aims to examine the time-varying dynamics of the causality interaction between agricultural raw materials commodity prices and the US economic policy uncertainty (EPU). To this end, we use monthly data for the period spanning from January 1992 to November 2021. We employ a time-varying Granger causality test to provide empirical evidence about the time-varying dynamics of the causality interaction and thereby revealing potential heterogeneities of these interactions during major historical events. The results show that causality running from EPU to agricultural raw materials, as well as causality running from agricultural raw materials to EPU, exhibits time-varying dynamics. More specifically, the findings reveal that causality generally tended to run from agricultural raw materials to EPU for most of the 2000-2014 period, but reversed with the US-China trade war and the Covid-19 pandemic period. This result highlights the importance of modeling the potential causality interactions in the economic uncertainty-commodity prices nexus within a dynamic framework and implies that these interactions cannot be considered independently of the prevailing economic, political and global conditions.
ÖNEMİ BELİRSİZ ATİPİLİ HASTALARDAKİ POSTOPERATİF HİSTOPATOLOJİK MALİGNİTE VARLIĞI
Authors: BAŞÇEKEN Salim İlksen , TİKİCİ Deniz
Published: March 2023

Amaç

Tiroid kanseri en sık görülen endokrin malignitesidir

ve klinik görünümü nodüllerle karakterizedir. Tiroid

patolojileri için yapılan biyopsilerde ‘Önemi belirsiz

atipi’ (ÖBA) literatürdeki farklı malignite oranları nedeniyle

klinisyenler için önemli bir endişe kaynağıdır. Bu

çalışmada, AUS tanısı alan ve tiroid cerrahisi geçiren

hastalarda malignite oranlarını güncel literatür ışığında

sunmayı amaçladık.

Gereç ve Yöntem

2016-2021 yılları arasında kliniğimizde ince iğne aspirasyon

biyopsisinde (İİAB) ÖBA tanısı alan ve tiroid

cerrahisi uygulanan 174 hastanın demografik ve histopatolojik

verileri retrospektif olarak analiz edildi. Hastalar

histopatolojik özelliklerine göre malign ve benign

olarak iki gruba ayrıldı. Gruplar arasındaki istatistiksel

anlamlılık Ki-kare ve Student t-testleri kullanılarak belirlenmiştir.

P değeri 0.05).

Sonuç

Bethesda sınıflamasına göre ÖBA için malignite oranı

%15-30 olarak belirtilmiştir. Çalışmamızda malignite

oranı, ülkemizde yapılan benzer çalışmalara benzer

olarak, %43.5 saptanmıştır. ÖBA tanısıyla tiroid cerrahisi

planlanan vakalarda, yüksek malignite olasılığı

nedeniyle, lobektomiye alternatif olarak total tiroidektomi

de bir seçenek olarak düşünülmelidir.
Results of complex treatment of patients with locally advanced squamous cell carcinoma of the paranasal sinuses and nasal cavity using induction chemotherapy
Authors: Dеshkina T.   I. , Bolotina L.  V. , Gevorkov A.  R. , Boyko A.  V. , Kornietskaya A.  L. , Polyakov A. P. , Golubev P.   V. , Sydykova R.  S. , Fedenko A. A.
Published: March 2023

Introduction. About 600 new cases of malignant neoplasms of the paranasal sinuses and nasal cavity are detected annually in Russia. To date, there are no randomized trials to determine the optimal treatment algorithm for this group of patients. Data on the use of induction chemotherapy in squamous cell carcinoma of sino-nasal tract are limited to a small series of clinical observations and, often, are retrospective in nature.

Aim. Evaluation of the effectiveness of induction chemotherapy in patients with locally advanced squamous cell carcinoma of the paranasal sinuses and nasal cavity.

Materials and methods. Since 2012, 22 patients with locally advanced cancer of the paranasal sinuses and nasal cavity have been treated in our center, who underwent 3-component induction chemotherapy according to the TPF protocol. Evaluation of the effectiveness of treatment was carried out according to the criteria of Response evaluation criteria in solid tumors 1.1 (RECIST 1.1). Patients with a decrease in the tumor size by 30 % or more, were followed by radiation therapy in doses of 66–70 Gy. Patients with a residual tumor underwent surgery after the end of chemoradiotherapy.

Results. In 21 patients available for analysis, overall response rate after induction chemotherapy was 71 %: complete response was registered in 3 (14 %) patients, partial response in 12 (57 %), stable disease in 4 (19 %). Progression disease after 3 courses of induction chemotherapy was detected in 2 (10 %) patients.

Conclusions. Thus, induction chemotherapy in patients with squamous cell carcinoma of sino-nasal tractseems to be a promising direction for investigation, that can significantly improve the long-term results of treatment of this category of patients and help to avoid of disabling surgery in some of them.
Results of treatment of patients with poorly differentiated carcinoma of the thyroid gland
Authors: Isaev P. A. , Polkin V. V. , Severskaya N. V. , Ilyin A. A. , Plugar A. K. , Ivanov S. A. , Kaprin A. D.
Published: March 2023

Introduction. Poorly differentiated carcinoma of the thyroid gland (PDTC) is characterised by aggressive, high rate of tumor growth, massive infiltration, early lymphogenous and hematogenous dissemination. Ways to improve treatment outcomes include developing individual treatment programmes. Given the unsatisfactory results of the treatment, the search for combined treatment options is well founded.

Materials and methods. An analysis was made of the treatment of PDTC in patients from May 2014 to July 2021. The study included 24 patients aged 22 to 81 years (9 (37.5 %) men and 15 (62.5 %) women). Surgical treatment was performed in 14 (58.3 %) cases. In 8 (33.3 %) cases, a course of radioiodine therapy with a total dose of 3–4 Gbq was performed in the postoperative period. Seven (29.2 %) patients underwent external beam radiation therapy. In 2 (8.3 %) cases, chemotherapy with carboplatin was performed simultaneously with external beam radiation therapy. Four (16.7 %) patients were prescribed lenvatinib. For one reason or another, 9 (37.5 %) patients did not receive treatment.

Results. For patients not treated, the overall survival rate was 5.8 ± 0.5 months, for patients treated – 9.6 ± 1.0 months (p <0.00095). According to the index Lenvatinib showed a significant increase in the general group of patients – up to 15 months.

Conclusion. Combined treatment in the form of a combination of surgical, radiation and chemotherapeutic methods at PDTC, allows to achieve much higher survival. In order to achieve longer-term stabilization, further research is needed on new ways to enhance the anti-tumor effect of modern drugs.
Comparison of transoral and combined approach for surgical treatment of moderately advanced tongue and floor of the mouth cancer
Authors: Karpenko A.   V. , Sibgatullin R.  R. , Boyko A.  A. , Nikolayeva O. M.
Published: March 2023

Introduction. Surgical approach for oral cancer treatment is one of the key factors that determines oncologic effectiveness, risk of postoperative complications, need for reconstructive methods etc. Currently, there exists lack of strict criteria for using one or another approaches based on the sound scientific evidence for a primary tumor of given depth of invasion.

Aim. The aim of the study is a retrospective comparative analysis of oncologic efficiency of transoral and combined approaches for surgical treatment of tongue and floor of the mouth moderately advanced carcinoma.

Materials and methods. 75 patients aged between 30 and 80 years with tongue and floor of the mouth squamous cell carcinoma with depth of invasion from 10 to 20 mm were included into the study. In 29 cases the tumor was resected transorally (Group 1), in 45 – via combined approach (Group 2). Group 2 patients had more advanced tumors both locally and regionally. 13 patients of Group 1 and 27 patients of Group 2 underwent adjuvant radiotherapy. The following parameters were used for comparative analysis: the rate of local and regional recurrence, locoregional control, the rate of distant metastasis and Kaplan–Meyer overall survival.

Results. Mean follow up was 33.77 ± 27.72 months (range 14–115 months). The rate of local and regional recurrence was higher in Group 2 (20 % vs 10.3 % and 22.2 % vs 17.2 % respectively). Locoregional control was better in Group 1 (72.4 % vs 62.2 %). The difference for neither of the above-mentioned parameters did not reach statistical significance. Median survival was statistically significantly better in Group 1: 66 ± 17.42 months vs 23 ± 3.85 months (p = 0.030). Poorer treatment results in Group 2 can be explained by a higher proportion of patients with more advanced tumors in this group.

Conclusion. The results of the present study do not allow to conclude that combined approach has oncologic advantage over less aggressive transoral approach for tumors with depth of invasion from 10 to 20 mm. It is questionable to recommend the combined approach as a universal one for lesions with such a stage of local invasiveness.
Targeted therapy of anaplastic thyroid cancer
Authors: Nikiforovich P.  A. , Polyakov A. P. , Sleptsov I.   V. , Boyko N.  S. , Gronskaya Yu.  A. , Timofeeva N.   I. , Chernikov R.  A.
Published: March 2023

Introduction. Anaplastic thyroid cancer (ATC) is a very rare malignant tumor of the thyroid comprising 1–2 % of all thyroid cancers. In this pathology, response rate for standard systemic therapy is less than 15 %, and long-term results remain unsatisfactory. Additionally, there are no data conclusively showing that cytotoxic chemotherapy improves survival or quality of life in patients with ATC.

Aim. To improve the results of treatment of patients with ATC through evaluation of the effectiveness of targeted therapy in cases of BRAFV600E mutation.

Materials and methods. The multicenter prospective study included 29 patients with ATC IVB–C, T4a–bN1a–bM0–1. The patients were divided into 2 groups. The Group 1 (control) included 15 patients with resectable / nonresectable, metastatic / nonmetastatic ATC (without BRAFV600E mutation), stages IVB–C who received standard types of treatment (surgical intervention, radiation, and chemotherapy). The Group 2 consisted of 14 patients with nonresectable or metastatic ATC, stages IVB–C, who received combination therapy (surgical intervention, radiation, and chemotherapy) with inclusion of inhibitors of BRAF dabrafenib and trametinib in neoadjuvant and adjuvant regimens.

Results. The study showed the effectiveness of targeted therapy with inhibitors of BRAF mutations in treatment of locally advanced non-operable metastatic ATC with BRAFV600E mutation. Overall response (complete response + partial response) in the Group 1 was 0 %, in the Group 2 it was 64 %. Therefore, treatment scheme dabrafenib + trametinib is a prmising approach to combination targeted therapy in patients with ATC and BRAFV600E mutation. C

onclusion. Dabrafenib + trametinib is a promising combination targeted therapy option for patients with ATC with a BRAFV600 mutation demonstrates a high overall response rate, a prolonged duration of response, and an increase in survival rates with controlled toxicity.
Proton beam therapy in repeat irradiation of recurrent head and neck tumors: analysis of short-term results
Authors: Smyk D. I. , Gulidov I. A. , Gordon K. B. , Gogolin D. V. , Dyuzhenko S. S. , Semenov A. V.
Published: March 2023

Introduction. Recurrence of head and neck tumors occurs in 50 % of cases and usually has locoregional character. Due to the characteristics of dose distribution, proton beam therapy is a promising treatment option for patients with recurrences of tumors in this location who previously underwent radiation therapy.

Aim. To evaluate the effectiveness and tolerability of repeat irradiation using active scanning proton beam therapy in patients with recurrent head and neck tumors who previously underwent radiation therapy.

Materials and methods. Between November of 2015 and December of 2020, 40 patients with locoregional recurrence of head and neck tumors underwent treatment using active scanning proton beam therapy at the A. F . Tsyb Medical Radiological Research Center – branch of the National Medical Research Radiological Center. Median cumulative dose of primary irradiation was 64.5 Gy. Median time between primary and repeat irradiation was 35.7 months, mean irradiated volume of the repeat course was 94.5 cm3. Proton beam therapy was performed using standard mode (2 isoGy) and accelerated hypofractionation (2.4 isoGy / 3 isoGy) with mean equivalent cumulative dose of 56.4 Gy (α / β = 10). Radiation toxicity was evaluated using the Radiation Therapy Oncology Group European (RTOG) / Organization for Research and Treatment of Cancer (EORTC) scale.

Results. Treatment response was achieved in 34 (85 %) patients: in 17 (42.5 %) patients, stable disease was observed; in 10 (25 %) patients, partial response was observed; and in 7 (17.5 %) patients, complete response was observed. In 6 (15 %) cases, disease progression was diagnosed at first follow-up examination. One- and two-year locoregional control, progression-free survival and overall survival were 58.4 / 19.8; 44.5 / 19.8 and 82.3 / 38.8 % respectively with median follow-up duration of 14.2 months. Median survival was 19.5 months. Grade III and above early radiation toxicity was observed in 3 (7.5 %) patients. In total, 6 (15 %) cases of grade III complications and 2 (5 %) episodes of carotid artery rupture leading to death were observed. Overall frequency of complications of grade III and higher was 20 %.

Conclusion. Repeat irradiation using proton beam therapy can be considered an effective and safe treatment method for patients with recurrent head and neck tumors. Dosimetric and radiobiological benefits of proton beams allow to achieve balance between high doses and radiation exposure in previously irradiated tissues.
Experience of using a supraclavicular flap in reconstruction of oral cavity defects
Authors: Berdigylyjov M. T. , Zaderenko I. A. , Kropotov M. A. , Aliyeva S. B. , Stelmakh D. K. , Dobrokhotova V. Z. , Berdigylyjova G. Sh.
Published: March 2023

Introduction. In case of cancer of the oral mucosa at the first stage, the standard treatment approach is radical surgical intervention, with the formation of extensive defects leading to aesthetic and functional disorders. Taking into account the characteristics of defects, choosing a flap is a difficult task. Currently, there is a wide selection of regional and microvascular free flaps. However, not all flaps meet the requirements. The supraclavicular fasciocutaneous flap, being a regional flap, has a number of advantages: easy to harvest, reliable due to the constancy of the vascular pedicle, primary closure of the donor site, scarcity of hair, the possibility of closing various defects of the oral cavity.

 Aim. To evaluate the possibility of using a supraclavicular flap in patients with oral cancer to restore the defects after surgical treatment.

Materials and methods. The study included 10 patients with malignant tumors of the oral cavity who underwent surgical intervention with defect replacement using supraclavicular flap at the N. N. Blokhin National Medical Research Center of Oncology between February of 2015 and May of 2021. In 4 cases, buccal mucosa was affected; in 3 cases, the retromolar area; in 1 case, oral floor mucosa; in 1 case, mandibular alveolar ridge; in 1 case, mobile tongue. Flap sizes were 5–10 × 5–8 cm. Three (3) patients had history of radiotherapy, and 1 of them had a radical dose.

Results. In 4 patients without previous radiotherapy, partial flap necrosis was observed. In 1 patient, sutural diastasis in the oral cavity after partial flap necrosis was diagnosed. There were no cases of total flap necrosis and fistula formation. Suture dehiscence in the donor bed was observed in 1 patient only.

Conclusion. Use of supraclavicular flap is an option for oral cavity defect replacement after surgical intervention in patients with malignant tumors of the oral cavity producing satisfactory esthetic and functional results. The advantages of this flap are simple flap dissection, reliability of vascular pedicle, flexibility, possibility of replacing large defects, scant hair coverage.
Central airway stenting in oncology
Authors: Krylovetskaya M. A. , Makarova M. V. , Komarov I. G. , Malikhova O. A. , Cherkes L. V.
Published: March 2023

Introduction. Malignant central airway obstruction and malignant tracheoesophageal fistula in the context of tumor development are potentially life-threatening conditions which usually require immediate intervention. Airway stenting is one of the safest and most effective methods of airway patency restoration in patients with malignant obstruction of the central airways and restoration of continuity in patients with malignant tracheoesophageal fistula.

Aim. To evaluate the significance of self-expandable metal stents in palliative treatment of patients with malignant central airway obstruction and malignant tracheoesophageal fistula.

Materials and methods. Between 2017 and 2021 at the N. N. Blokhin National Medical Research Center of Oncology, 55 patients were observed and treated and underwent trachea stenting per the results of bronchoscopy in combination with esophagogastroduodenoscopy. The 1st group included 25 patients with malignant tracheoesophageal fistulas, the 2nd group included 30 patients with malignant central airway obstruction.

Results. In the 1st group, stenting was successful in 25 (100 %) cases which allowed to adequately seal the fistula. Stent migration was observed in 1 (4 %) patient with tracheoesophageal fistula in the context of stenosing cancer of the thoracic esophagus. In the 2nd group, stenting was successful in 30 (100 %) cases. Stent migration was not observed in this patient group. In both groups, there were no complications after stent implantation. Installation of tracheal stent allowed to improve patients’ quality of life and provide a possibility for successful special treatment through low-trauma manipulation.

Conclusion. According to the obtained data, endoscopic trachea stenting is the most important method of palliative treatment of tumor-related trachea lesions with development of tracheoesophageal fistulas, malignant central airway obstructions and associated sub- and decompensated pulmonary insufficiency.
Methylation of the tumor associated genes in head and neck squamous cell carcinoma
Authors: Kurevlev S. V. , Tskhovrebova L. V. , Aghajanyan A. V. , Fatkhudinov T. Kh. , Gordon K. B. , Azova M. M.
Published: March 2023

Introduction. Head and neck cancer is a heterogenous group of malignant tumors of different etiologies, molecular mechanisms of which are still insufficiently studied.

Aim. Investigation of DNA methylation status of some tumor associated genes (RASSF1A, RASSF2, RASSF5, CDO1, MEST and WIF1) in patients with head and neck squamous cell carcinoma.

Materials and methods. The DNA methylation level of normal and tumor tissues was analyzed using bisulfite conversion and methylation-sensitive high-resolution melting in 25 patients (21 men and 4 women) diagnosed with neck squamous cell carcinoma.

Results. There were significant differences in levels of DNA methylation between tumor and normal tissues in the CDO1 and WIF1 genes in all groups and subgroups of patients (larynx and other cancers, squamous cell carcinoma keratinizing and non-keratinizing, primary and recurrent tumor, smokers and non-smokers). The methylation level in the CDO1 gene in tumor tissue was significantly increased in the T4 and T3 stage subgroups compared to T2.

Conclusion. The increased level of methylation of the CDO1 and WIF1 genes, as well as changes in their expression are among the molecular mechanisms involved in the neck squamous cell carcinoma development. They can be considered as prognostic and diagnostic markers for this pathology.
Retrospective comparison of individual risk factors hemithyroidectomy and thyroidectomy in patients with papillary carcinoma of the thyroid gland in combination with autoimmune thyroiditis
Authors: Ryabchenko E. V.
Published: March 2023

Introduction. Papillary thyroid carcinoma is the most common subtype of thyroid cancer as it comprises 95 % of cases. Frequently, this pathology develops in the presence of autoimmune thyroiditis (Hashimoto’s thyroiditis) which is the main cause of hypothyroidism in various rich in iodine regions. Papillary thyroid carcinoma is characterized by good prognosis, however some patients experience recurrence which depends on the volume of surgical intervention.

Aim. To compare clinical outcomes and complications after hemithyroidectomy (HE) and thyroidectomy (TE) in patients with papillary thyroid carcinoma secondary to autoimmune thyroiditis.

Materials and methods. The retrospective study included 2031 patients with papillary thyroid carcinoma. Considering individual risk factors, 67 patients were excluded from the HE group, and 588 patients were excluded from the TE group. Each group included 688 patients for whom data were matched. Such individual factors as age, sex, primary tumor size, extrathyroidal invasion, multifocal tumor and cervical lymph node metastasis were taken into account.

Results. During 10‑year follow-up, recurrence was diagnosed in 26 (3.8 %) patients of the HE group and 11 (1.6 %) patients of the TE group. Relative risk of recurrence was significantly lower after TE than after HE (risk ratio (RR) 0.41; 95 % confidence interval (CI) 0.21–0.81; р = 0.01). In the HE group, for the majority of patients recurrence was observed in the contralateral lobe of the thyroid (84.6 %). In the TE group, there were no recurrences in all patients. There were no significant differences between the groups after exclusion of recurrence in the contralateral thyroid lobe (RR 2.75; 95 % CI 0.08–8.79; р = 0.08). In the TE group, the number of patients with transient and permanent hypothyroidism in the TE group was significantly higher than in the HE group (р <0.001).

Conclusion. Hemithyroidectomy is appropriate for the majority of patients with papillary thyroid carcinoma in the absence of extrathyroidal invasion in the neighboring tissues per preoperative examination. For patients after HE, preoperative and postoperative diagnostic examinations are important as most recurrences develop in the contralateral thyroid lobe.
Distant metastasis of alveolar rhabdomyosarcoma with pancreatic parameningeal localization in children: clinical case series
Authors: Rodina A. D. , Polyakov V.  G. , Gorbunova T.  V. , Merkulov O.  A. , Kashanina A.  L. , Odzharova A. A. , Stroganova A.  M.
Published: March 2023

Rhabdomyosarcoma is a malignant neoplasm that develops from embryonic mesenchymal cells, with an annual incidence of 4.3 cases per 1,000,000 children. The prevalence of the tumor process is estimated on the basis of data from a comprehensive examination, including magnetic resonance imaging with intravenous contrast, ultrasound examination of the primary focus of regional and distant metastasis zones, computed tomography and radioisotope studies. The overall 5-year survival rate for localized rhabdomyosarcoma reaches 70 %. During the initial diagnosis, distant metastasis to the lungs, bones, and bone marrow is detected, which significantly worsens the prognosis in 20–25 % of patients. The factors of an extremely unfavorable prognosis for the course of alveolar rhabdomyosarcoma are the occurrence of regional and distant metastases before the start of specific treatment, dissemination of the tumor lesion during treatment, and the presence of translocation of the 13q14 sector. Publications contain data on a high (11.2 %) prevalence of metastases of alveolar rhabdomyosarcoma in the pancreas. In the presence of metastatic lesions of the pancreas, surgical treatment is effective only in combination with chemoradiotherapy. Long-term results of treatment of this cohort of children are unsatisfactory due to the high risk of recurrence and dissemination of the tumor.

Aim. To study risk factors, evaluate methods and prospects for the treatment of children with metastatic pancreatic lesions in parameningeal alveolar rhabdomyosarcoma. The article considers three clinical cases of such a lesion. We would like to draw the attention of pediatric oncologists and radiologists to the possible association of metastases in the pancreas in children with localization of rhabdomyosarcoma in the head and neck region, which requires improvement of examination protocols in this group of patients.
Efficacy of two-stage approach for interventional treatment of coexistent atrial fibrillation and typical atrial flutter for sinus rhythm maintenance in long-term: a prospective controlled clinical trial
Authors: Khamnagadaev Igor A. , Kovalev Igor A. , Bulavina Irina A. , Kokov Mikhail L. , Zotov Aleksandr S. , Troitskiy Aleksandr V. , Khamnagadaev Igor I. , Shkolnikova Maria A. , Kokov Leonid S.
Published: March 2023

Background: Atrial fibrillation (AF) and coexistent typical atrial flutter (AFL) interventional treatment strategy remains unresolved in cardiology and cardiovascular surgery. Results of this approach remain suboptimal. There are several approaches to the interventional treatment of patients with coexistent AF and AFL: simultaneous pulmonary vein isolation (PVI) and cavotricuspid isthmus (CTI) radiofrequency catheter ablation (RFCA), PVI or CTI RFCA only and two-stage approach. To our knowledge, cumulative efficacy of two-stage approach has not been previously reported.
The aim. This study aimed to evaluate the efficacy of two-stage approach for interventional treatment of coexistent AF and AFL for sinus rhythm maintenance in long-term.
Methods: Patients (pts) (n=34) with AF and AFL aged 41–82 years (11 women) were divided into two groups (1:1): «One-stage Approach» (group 1; n=17): PVI+СTI RFСA and «Two-stage approach» (group 2; n=17): first stage — CTI RFCA (group 2.1); second stage — PVI in case of AF recurrence after RFCA (group 2.2). Primary endpoint (PEP) was defined as any recurrent atrial tachyarrhythmia at the end of follow-up; group 2 events have been considered after PVI. Secondary endpoint (SEP) — recurrent any atrial tachyarrhythmia in groups 1 and 2 after CTI RFCA in group 2. PEP and SEP were evaluated at the end of the «blind period» (3 months after procedure).
Results: Registered recurrent atrial tachyarrhythmia in pts who reached PEP or SEP was AF. AFL has not been detected in any cases. PEP was noted in 8 (47.06%) pts in group 1 and 1 (5.88%) pts in group 2. Further, SEP was observed in 3 pts (17.65%) in group 1 and in 4 (23.53%) pts in group 2 (p=0.671). The probability of long-term maintenance of sinus rhythm was significantly higher in «Two-stage approach» than in «One-stage approach» (94.12% and 52.94%, respectively, p=0.001). Significant differences in procedure length and fluoroscopy time have been found. Those were longer in group 1 compared to group 2.1 (p 0.001) and in group 2.2 compared to group 2.1 (procedure duration — p 0.001; fluoroscopy time — p=0.013). No differences were noted in length of procedure and fluoroscopy time between groups 1 and 2.2 (p=0.374 and p=0.028, respectively).
Conclusion: The «two-stage approach» for interventional treatment of coexistent AF and AFL results in better long-term arrhythmia-free survival than «one-stage approach» (94.12% and 52.94%, respectively, p=0.001). CTI RFCA alone in pts with coexistent AF and AFL cause 23.53% AF recurrence rate and associated with shorter procedure duration and fluoroscopy time compared to simultaneous PVI and CTI RFCA (p 0.001).
The case of food botulism F
Authors: Nikolaeva Irina V. , Gilmullina Fayruza S. , Kazancev Aleksander Yu. , Fatkullin Bulat Sh.
Published: March 2023

This case describes a rare case of food botulism F in a 42-year-old man, which developed after he ate dried fish. The disease proceeded in a severe form with the development of ophthalmoplegia, tetraparesis, and respiratory failure. Monovalent antitoxic serums against botulinum toxins A, B, and E were administered to the patient. However, on the third day of the disease, he developed fulminant toxic myocarditis with asystole. Despite successful resuscitation, the patient developed a post-resuscitation disease and anoxic encephalopathy. The disease was complicated by severe aspiration pneumonia caused by Klebsiella pneumoniae (ESBL+). The duration of mechanical ventilation was 12 days. His hemodynamics stabilized on the eighth day of illness, and on the 19th day of illness, physical activity and a state of minimal consciousness appeared. The patient was transferred to the rehabilitation department on the 22nd day of the illness.
Doctors should be informed about the possibility of the development and severity of botulism caused by botulinum toxin type F. It is necessary to introduce polyvalent antibotulinic serum into clinical practice, including antitoxins against rare types of botulinum toxin.
Express method for determining the sensitivity of pathogens of bacterial complications in COVID-19 to bacteriophages
Authors: Kraeva Lyudmila A. , Konkova Lidiya S. , Burgasova Olga A. , Dolinny Sergey V.
Published: March 2023

BACKGROUND: In recent years, there has been a catastrophic increase in the resistance of bacterial strains to antibacterial drugs. The spread of the novel coronavirus disease (COVID-19) pandemic has led to the overuse of antibiotics, which has led to an even greater spread of resistant strains in hospitals. Given the accumulated positive experience in using bacteriophages, it is advisable to use them in patients after determining the sensitivity of each strain of isolated bacteria to bacteriophages. Since Klebsiella pneumoniae was the most frequently isolated bacteria in complicated forms of COVID-19, it became necessary to determine the sensitivity of these and other gram-negative bacteria to the corresponding bacteriophages.
AIM: This study aims to reduce the time for determining the sensitivity of an isolated microorganism culture to bacteriophages by developing an express method.
MATERIALS AND METHODS: The study used 30 strains of pan-resistant Gram-negative microorganisms from the collection of the Museum of the Laboratory of Medical Bacteriology of the Pasteur Research Institute of Epidemiology and Microbiology in St. Petersburg: Klebsiella pneumoniae (n=10), Escherichia coli (n=10), Pseudomonas aeruginosa (n=10), and also preparations of bacteriophages manufactured by JSC NPO Microgen: Bacteriophage Klebsiella polyvalent purified; Bacteriophage coliproteus; Pseudomonas aeruginosa bacteriophage.
RESULTS: Of the strains studied, 4 out of 10 studied K. pneumoniae strains, 6 out of 10 E. coli strains, and 7 out of 10 P. aeruginosa strains were susceptible to polyvalent bacteriophage preparations. Reliable results were obtained 3 hours after the sensitivity of isolated cultures to bacteriophages was established, which is undoubtedly the most important finding of the study.
CONCLUSION: The developed method for determining the sensitivity of gram-negative bacteria to bacteriophages enables reducing the study time by 6 times (up to 3 hours), which affects the timing of etiotropic therapy selection with bacteriophages for each patient.
Antimicrobial properties of oxygen-active disinfectants
Authors: Gerasimov Vladimir N. , Kharseeva Galina G. , Gaitrafimova Aigul R. , Bystrova Elena V. , Fedorova Ludmila S.
Published: March 2023

Oxygen-active disinfectants are widely used for the nonspecific prevention of infectious diseases: hydrogen peroxide, chlorine dioxide, potassium fluoride peroxyhydrate, perborates, persulfates, perphosphates, and percarbonates. These compounds have a broad spectrum of antimicrobial activity against bacteria (including Mycobacterium tuberculosis), viruses, fungi, and spores of bacilli.
The primary exposure targets exposure for oxygen-containing disinfectants are proteins and lipids in the cytoplasmic membranes of bacterial cells and the spore membranes of bacterial spores. When a bacterial cell is exposed to hydrogen peroxide at the stage of contact with the cytoplasmic membrane, hydrogen peroxide decomposes into highly reactive hydroxyl radicals, which have a destructive effect on the membranes. Hydroxyl radicals are powerful oxidizing agents, have a short existence and interact with lipids, proteins, and nucleic acids. Lipid oxidation, mainly unsaturated fatty acids, leads to increased membrane permeability. During the membrane protein oxidation consisting of amino acids with disulfide bonds, the latter are converted into SH-radicals, forming cross-links at amino groups and resulting in protein-lipid complexes. The proteins are oxidized and denatured, leading to cell death. Hydroxyl radicals and other intermediate decomposition products of hydrogen peroxide, such as hydronium cation (Н3О+) and perhydroxylanion (НО2-), have damaging effects.
This article analyzes scientific papers on the mechanism of action of oxygen-active disinfectants on vegetative cells and bacterial spores.
An Adaptive Confidentiality Security Service Enhancement Protocol Using Image-Based Key Generator for Multi-Agent Ethernet Packet Switched Networks
Authors: Abukhait Jafar J. , Saleh Ma’en S.
Published: March 2023

Conventional network Security Protocols provide different types of security services that establish secure connections between network nodes making them robust against different security threats. The security establishment process depends on sharing security keys between connected devices. The level of security provided by such security protocols is static and irrelevant to the status of the network. In this paper, we propose an adaptive security-aware lottery-EDF scheduler for limited resources Ethernet packet switched networks using GAIA multi-agent approach. The proposed system adopts a periodic non-shared cryptographic key-generation process of different sizes (i.e., 64 bits, 128 bits, 160 bits, and 512 bits) using the textural features of digital images stored on a central image-server. The proposed system deploys a security enhancement unit that adaptively enhances the confidentiality security-service level for the real-time packets according to feedback from a congestion control scheme that is based on network resource estimation technique, hence making the network robust against the spoofing security threat while preserving the overall network performance metrics (NPMs). By simulating a real-time Ethernet packet switched network, extensive simulation results show the efficiency of the adaptive proposed protocol over the static-security and IPSec protocols in guaranteeing the QoS requirements for the real-time flows in terms of destination’s buffer consumption and average total packet delays.
Effectiveness of Combining Oketani and Oxytocin Massage on The Breastmilk Production
Authors: Indrayani Triana , Choirunnisa Risza , Lumprom Orachorn
Published: March 2023

Background: The percentage of exclusive breastfeeding for babies aged 0-5 months was 71.58% in 2021. This figure is still below the target of 80%. Meanwhile, the coverage of exclusive breastfeeding in West Java was recorded at 77.00% in 2022. Breastfeeding revolves around two mechanisms, namely, production and release. Objective: To determine the effect of the combination of oketani massage and oxytocin massage on breastmilk production in postpartum mothers. Methods: This research was conducted from July to November 2022 at the L TPMB. This study utilized a quantitative approach with a quasi-experimental design using a pre and post-test with a control design. The sample consisted of 100 respondents divided into experimental and control groups. In this case, the intervention was given to the experimental group in the form of oxytocin massage and oketani massage 1 to 2 times a day for 3 days for 3-5 minutes. Meanwhile, the control group was only given oxytocin massage treatment. The instrument used in this study was the Observation Sheet Procedure to identify the breastmilk production in postpartum mothers on day 1 and was measured again on day 7 through the smooth release of breastmilk. In addition, the instrument was made by the researcher according to Standard Operation Procedures. The analysis used was the man Whitney test. Result: Oketani massage could be performed as an independent and routine prophylactic intervention. Conclusion: The combination of oketani massage and oxytocin massage had a significant effect on breastmilk adequacy.