bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nanostructured mesoporous g-Fe2O3: a novel photocatalyst for degradation of organic pollutants
Authors: Hrubiak A.B. , Khyzhun O.Yu. , Ostafiychuk B.K. , Moklyak V.V. , Yavorskyi Yu.V. , Lisovsky R.P. , Keush L.G. , Onyskiv B.B. 
Published: March 2021

The modified sol-gel synthesis technique was used to created of nanostructured maghemite (γ-Fe2O3). It has been shown that the molar concentration of the original precursors during synthesis affects on the average particle sizes, specific surface area, pore size distributions, optical and conductivity properties. The XPS metod allowed to establish features of electronic structure of the synthesized materials. Optimal conditions for the synthesis of nanostructured maghemite with mesoporous structure were selected. The mechanism of electrical conductivity formation for synthesized mesoporous materials was established. The width of the band gap is determined and its dependence on the molar concentration of precursors is established. The positive correlation between the specific surface area of γ-Fe2O3 samples and photocatalytic activity was installed - the photocatalytic activity of synthesized γ-Fe2O3 increase with growth of specific surface area of γ-Fe2O3 samples.
Solubility of Cu, Ni, Mn in Boron-Rich Fe-B-C Alloys
Authors: Sukhova O.V. 
Published: March 2021

In the present study, the microstructure development and mechanical properties of the cast boron-rich Fe–B–C alloys cooled at 10 and 103 K/s were investigated as functions of alloying elements additions. These alloys were prepared in the following compositional ranges: B (10–14 wt.%), C (0.1–1.2 wt.%), M (5 wt.%), where M – Cu, Ni or Mn, balance Fe. Structural properties were characterized by quantitative metallography, X-Ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy. Mechanical properties of the structural constituents, such as microhardness and fracture toughness, were measured by a Vickers indenter. Copper becomes negligibly incorporated into the phases Fe(B,C) and Fe2(B,C) of the Fe–B–C alloys, but solubility limit forces the remaining solute into the residual liquid. As a result, the globular Cu inclusions are seen in the structure. As compared with copper, nickel has higher solubility in the constituent phases, with preferential solubility observed in the Fe2(B,C) crystals, where Ni occupies Fe positions. Having limited solubility, nickel also forms secondary Ni4B3 phase at the Fe2(B,C) boundaries. Manganese was found to dissolve completely in the Fe–B–C alloys forming substitutional solid solutions preferentially with Fe(B,C) dendrites. By entering into the iron borides structure, Mn and Ni improve their ductility but lower microhardness. The peculiarities in the structure formation and properties of the doped boron-rich Fe–B–C alloys were explained with electronic structure of the alloying elements considered.
First principles DFT calculations of the optical properties of A4BX6 group crystals
Authors: Ilchuk H. , Solovyov M. , Lopatynskyi I. , Honchar F. , Tsyupko F. 
Published: March 2021

The results of investigating of the electron band energy structure and optical properties of A4BX6 (Tl4HgI6 and Tl4CdI6) group crystals are presented. The energy band structures of Tl4HgI6 and Tl4CdI6 crystals are calculated from the first principles within generalized gradient approximation (GGA). The band structure and reflection index were calculated using a pseudopotential method in the framework of density functional theory. Optical absorption edge in Tl4HgI6 and Tl4CdI6 is formed by direct optical transitions. The spectral dependence of the reflection index was calculated on the basis of the energy band results with using the Kramers–Kronig method. The spectra show pronounced anisotropy in E||a(b) and E||c polarizations. It was found the anomalous by large values of the birefringence (Δn > 0.18 for Tl4HgI6 and Δn > 0.03 for Tl4CdI6) in the visible and near infrared region.
Synthesis and Electrochemical Properties of Nanocrystalline Nickel Molybdate
Authors: Popovych O.M. , Budzulyak I.M. , Popovych O.V. , Rachiy B.I. , Ilnytskyi R.V. , Yablon L.S. , Morushko O.V. 
Published: March 2021

We have obtained nanocrystalline hydrate and alpha phase of nickel molybdate by a hydrothermal technique. On the basis of the obtained cyclic voltammetry data, we have evaluated the contribution of faradaic and non-faradaic processes to the total capacitance of molybdates under study. It was found that the specific capacitance of hydrate NiMoO4·H2O is 621 F/g at a scan rate of 1 mV / s and the specific capacitance of the α-NiMoO4 is 281 F/g. Cathodes for hybrid supercapacitors were formed on the basis of the obtained nickel molybdates. As a result of electrochemical studies, it was found that the specific capacitance of hybrid supercapacitor based on NiMoO4·H2O/C was 256 F/g at the current of 0.2 A/g, while the specific energy was 80 W h/kg and specific power – 304 W/kg and these results are higher below in the α-NiMoO4 /C-based hybrid supercapacitor.
Interaction of N-acetylneyraminic acid with surface of silica with fructose in aqueous solution
Authors: Ushakova L.M. , Demianenko E.M. , Terets M.I. , Lobanov V.V. , Kartel N.T. 
Published: March 2021

Quantum chemical simulation of the adsorption of N acetylneuraminic acid (NANA) on the surface of silica with the participation of the fructose molecule by the method of density functional theory B3LYP, 6-31G (d, p) was done. The influence of the solvent was taken into account in the supermolecular and continuum approximations, and a cluster approach was used for the adsorption complexes. NANA adsorption of the hydrated silica surface was considered as a process of replacement of water molecules on the silica surface by adsorbate molecules. Two schemes of influence of fructose molecule on NANA adsorption are considered. According to the first scheme, the hydrated NANA molecule interacts with the hydrated silicon-fructose adsorption complex. According to the second scheme, the cluster of hydrated silica interacts with the hydrated NANA-fructose complex. The energy of intermolecular interaction according to the scheme 1 is -9.2 kJ / mol, which is significantly lower compared to the same value with the participation of glucose or sucrose (-20.5 and -86.2 kJ / mol). Scheme 2 proved to be a thermodynamically unfavorable process, as its energy effect is +6.9 kJ / mol, in contrast to similar processes for glucose (-21.8) and sucrose (-87.7 kJ / mol). This confirms the experimental fact of the interaction of substances in a mixture of NANA with carbohydrates in relation to the interaction with silica in comparison with the interaction of substances with silica separately.
Escritura (registro) de las prácticas de enseñanza como una forma de producir conocimiento en las carreras de grado
Authors: García Vargas Silvia E. , Silva Santos Tatiane 
Published: March 2021

This article is part of an international research project called “Writing about teaching practices in undergraduate programs in Brazil, Costa Rica, and Honduras: record, analysis, and production of knowledge”, whose goal has been to discuss the role of writing in undergraduate courses at participating universities. Our analysis is about the discussion of the role of reading and writing in addition to presenting texts produced by professors from Universidade do Estado de Mato Grosso, Brazil and Universidad Nacional, Costa Rica in order to analyze the impact that writing time has for training and how this task should be seen by professors as a way to transform learning from the union of theory, practice, and the reflection carried out by the students.
O percurso escrito da observação no estágio supervisionado à sua leitura no curso de Letras
Authors: Clementino Chalegre Luana 
Published: March 2021

This paper seeks to verify the way in which students’ register occurs throughout their supervised internship and identify the difficulties that students have while communicating what they have observed in class in written form in their field diaries and their internship reports. We highlight the importance of keeping a record of the supervised internship, and to do this, it is necessary to plan how the internship is to be carried out. In other words, this activity cannot take place spontaneously because that would affect teachers’ future reflexive training. Thus, written records are of the utmost importance to organize thoughts and not lose track of events, thereby obtaining consistent data, which allows having more reliable field diaries and reports. In fact, this is not an easy activity to observe and record since that implies and requires resistance and insistence in the search of a coherent text with the experiences lived in the classroom. This paper has been developed as part of the project A escrita sobre as práticas de ensino em licenciaturas do Brasil, da Costa Rica e de Honduras: registro, análise e produção de conhecimento (Chamada Universal MCTI/CNPq Nº 14/2014).
Mechanisms of programmed cell death
Authors: A Ali Azzwali Abdu-Alhameed , Elsayed Azab  Azab 
Published: March 2021

The present review aims to spotlight on the mechanisms and stages of programmed cell death. Apoptosis, known as programmed cell death, is a homeostatic mechanism that generally occurs during development and aging in order to keep cells in tissue. It can also act as a protective mechanism, for example, in immune response or if cells are damaged by toxin agents or diseases. In cancer treatment, drugs and irradiation used in chemotherapy leads to DNA damage, which results in triggering apoptosis through the p53 dependent pathway in cancer treatment, drugs and irradiation used in chemotherapy leads to DNA damage, which results in triggering apoptosis through the p53 dependent pathway. Corticosteroids can cause apoptotic death in a number of cells. A number of changes in cell morphology are related to the different stages of apoptosis, which includes nuclear DNA fragmentation, cell shrinkage, chromatin condensation, membrane blebbing, and the formation of apoptotic bodies. There are three pathways for apoptosis, the intrinsic (mitochondrial) and extrinsic (death receptor) are the two major paths that are interlinked and that can effect one another. Conclusion: It can be concluded that apoptosis is a homeostatic mechanism that generally occurs during development and aging in order to keep cells in tissue. Drugs and irradiation used in chemotherapy leads to DNA damage, which results in triggering apoptosis through the p53 dependent pathway. The apoptosis, stages are includes nuclear DNA fragmentation, cell shrinkage, chromatin condensation, membrane blebbing, and the formation of apoptotic bodies. There are three pathways for apoptosis.
Improvement in cell growth and ethanol productivity of Saccharomyces cerevisiae due to poultry litter biochar
Authors: A Agblevor Foster , Diallo Oumou 
Published: March 2021

The effect of poultry litter biochar on Saccharomyces cerevisiae growth and ethanol fermentation was investigated for glucose, steam exploded corn stover and poplar wood. S. cerevisiae grew faster in both anaerobic and aerobic biochar medium than the control media. For the same initial concentration of glucose, the biochar medium glucose was consumed in 12 hours compared to 24 hours for control and the maximum ethanol productivity were higher for the biochar compared to the control medium. When the initial glucose concentration was increased the maximum ethanol productivity for the biochar media was more than two times that for the control. Similarly, addition of poultry litter biochar to steam exploded poplar wood and corn stover improved the ethanol productivity depending on the amount of biochar added to the fermentation medium. Thus, biochar is an effective additive to reduce ethanol fermentation time
Investigating entrance channel influences in the fusion of some heavy–ion systems
Authors: Girma Asnake , Fessahatsion Amanuel 
Published: March 2021

The dynamics of heavy-ion fusion reaction involved in the interaction of 12C,14N and 16O projectiles with,59Co, 51V,128Te and165Ho targets at≈3-8MeV/nucleon speciﬁc energies was studied. This study focus on the correlation between entrance channel properties and incomplete fusion reaction. The experimentally measured excitation functions of various reaction products populated by complete and/or incomplete fusions of 12C+59Co, 128Te,14N+128Teand 16O+ 51V, 165Hoprojectile-target systems available in the literature. Were compared and analyzed with the predicted excitation functions, using the statistical model code PACE4. For representative non-α-emitting channels, the experimentally measured excitation functions were, in general, found to be in good agreement with the theoretical predictions. However, for α-emitting channels in the present systems, the measured excitation functions were higher than the predictions of the theoretical model code, which may be credited to incomplete fusion reactions at these energies. An attempt was made to approximate the incomplete fusion fraction that explains the relative importance of incomplete fusion processes. The incomplete fusion fraction was found to be sensitive to the projectile energy and mass-asymmetry of the entrance channel
Complications after simultaneous prepectoral breast reconstruction using polyurethane-coated implants in patients with breast cancer
Authors: Vlasova M. Yu. , Zikiryakhodzhaev A. D. , Reshetov I. V. , Usov F. N. , Saribekyan E. K. , Shirokikh I. M. , Gerasimov A. N. , Khakimova Sh. G. , Starkova M. V. , Ablitsova N. V. , Tregubova А. V. , Berestok T. S. 
Published: March 2021

Background. The development and improvement of reconstructive breast surgery provides medical, psychological and social rehabilitation of cancer patients, allowing them to achieve the best cosmetic and functional results. The trend towards the return of prepectoral reconstruction is associated not only with the improvement of mastectomy techniques, but also with implant coating and the emergence of highly cohesive silicone gel filling of implants. The use of polyurethane-coated endoprostheses in prepectoral reconstruction provides more reliable fixation to the surrounding tissues and allows reconstruction of the mammary glands without additional covering of the endoprosthesis.Objective: to improve the results of surgical treatment when performing a one-stage reconstruction by pre-rectal placement of polyurethanecoated implants in breast cancer. Materials and methods. In the period from April 2017 to September 2020 at the Department of Oncology and Reconstructive Plastic Surgery of the Breast and Skin of P.A. Herzen Moscow Oncology Research Institute performed 340 prepectoral breast reconstructions (direct-toimplant) using polyurethane-coated implants in breast cancer patients. A group of patients was analyzed (n = 208).Results. We noted the following complications: prolonged seroma (more than 30 days) in 39 (18.6 %) patients, red breast syndrome in 31 (14.8 %) patients, capsular contracture III–IV degree by J.L. Baker in 43 (20.57 %) patients, protrusion/extrusion of the endoprosthesis in 23 (11 %) patients, suture divergence in 8 (3.8 %) patients, necrosis in 8 (3.8 %) patients, infectious complications in 14 (6.7 %) patients, ripping in 10 (4.8 %) patients. Also, 2 (0.95 %) patients had a violation of the integrity of the endoprosthesis, and 2 (0.95 %) patients had rotation of the endoprosthesis. Conclusions. Prepectoral breast reconstruction can be used as an alternative to subpectoral reconstruction in primary operable forms of breast cancer with sufficient thickness of integumentary tissues.
Possibilities of mammography, ultrasound, and MRI in the differential diagnosis of microcarcinomas of various biological subtypes of invasive breast cancer
Authors: Alieva G. S. , Korzhenkova G. P. , Kolyadina I. V. 
Published: March 2021

Objective:to study the radiological and sonographic features of microcarcinomas of various biological subtypes.Materials and methods.The analysis included 59 patients (median age – 55 years) with invasive breast cancer (BC) pT1a–bN0M0 stages at the N.N. Blokhin Russian Cancer Research Center. The frequency of distribution of luminal A, luminal B HER2 negative, HER2 positive (HER2+) and triple negative subtypes of BC was 39 %, 23.7 %, 23.7 % and 6.8 %, respectively. The analysis of key radiological characteristics and sonographic features of microcarcinomas with different biological structures associated with the diagnosis according to the BI-RADS criteria was carried out.Results.Tumors with luminal A and B subtypes had the most characteristic of malignancy (presence of a node ± microcalcinates), which allowed us to establish the category of BI-RADS 4–5 in mammography (MMG) in 82 % and 88.9 % of patients, respectively. Triple negative cancer is characterized by the presence of a node without microcalcifications; the BI-RADS 4–5 category is exposed in 75 % of cases. Maximum of the difficulties noted in the diagnosis of HER2+ subtype: 4 type density BC (18.2 % of cases), absence of tumor site during surgery in 57.1 % of cases and atypical characteristics of the node (16.7 %) and iso/hypodense structure node (33.4 %) resulted in high frequency of false-negative results in MMG (BI-RADS 0–3 35.7 %), p = 0.049. In addition, HER2+ early BC has proven to be the most difficult subtype for sonographic diagnosis too. The absence of a tumor node in sonography in 14.2 % of cases, as well as its atypical characteristics (iso/hyper echogenicity in 16.7 % of cases and the absence of an acoustic shadow in 18.2 % of patients) led to a high frequency of BI-RADS 0 (21.4 %), which required further examination of these patients.Conclusions.HER2+ early BC was the most difficult biological subtype for MMG and sonographic diagnostics
Occult breast cancer. Literature review and case series
Authors: Khodorovich О. S. , Solodkiy V. A. , Kalinina-Masri A. A. , Bliznyukov О. Р. , Sherstneva T. V. , Lazukina I. A. , Kanakhina L. B. 
Published: March 2021

Background. Currently, there are several forms of breast cancer (BC): nodular, diffuse, edematous-infiltrative, mastitis-like form, as well as Paget’s cancer. A special form of BC is the hidden or occult form. Taking into account the analysis of methods for the diagnosis and treatment of occult BC, it is important that this form of the disease is detected at a later stage. It includes axillary lymphadenopathy and histologically appears to be a metastatic lesion of the lymph nodes from undetectable invasive BC.Materials and methods. We conducted a thorough analysis of domestic and foreign literature and described two clinical examples with authentic documentation of the results of the examination and treatment. The article describes in detail the schemes of drug treatment and descriptions of the results of morphological examination of the surgical material.Results. Given the complexity of the diagnostic stage, the clinical form of the course of diseases, the described clinical examples can be attributed specifically to the occult form of BC. An important and determining factor in treatment is the diagnostic stage using all possible methods, including positron emission tomography–computed tomography, breast magnetic resonance imaging and trepan-biopsy of regional lymph nodes, followed by the determination of the molecular biological subtype of the tumor.Conclusions. In this article, the presented data confirm the general statement about the uniqueness of this disease, which requires a more detailed and multidisciplinary approach at the stage of diagnosis and determination of treatment tactics.
Prognostic value of microRNA assessment in cervical epithelial cells of patients with mild dysplasia
Authors: Knyazeva M. S. , Prisyazhnaya Т. S. , Zabegina L. M. , Smirnova О. A. , Mikhetko A. A. , Berlev I. V. , Malek A. V. 
Published: March 2021

Background. Currently, there are no reliable markers for the prognosis of the low-grade squamous intraepithelial lesion (LSIL) of the cervical epithelium. Scientific literature provides with inconsistent recommendations regarding the management of the young patients with a cytological diagnosis of LSIL. The progression of cervical dysplasia and the development of cervical cancer are associated with characteristic alterations of the microRNA expression profile.Objective: to assess the prognostic value of microRNA in LSIL. Materials and methods. Samples (cytological smears) obtained from patients diagnosed with LSIL (n = 36), but with a different course of the disease over the next 6–12 months. Analysis of miRNA expression was carried out by the method of “two-tailed” reverse transcription and subsequent PCR.Results. The expression level of miR-126, miR-21, miR-1246, miR-182 was statistically significantly different in the compared groups, but the predictive value of the analysis of individual molecules was low (AUC <0.65). Calculation of the concentration ratios of the “reciprocal” pairs of microRNAs made it possible to obtain a more effective prognostic marker. ROC analysis of such ratios (miR-126/miR-182, miR-21/miR-182, miR-1246/miR-182) yielded AUC values: 0.82–0.89, sensitivity: 0.71–0.92; specificity: 0.86.Conclusions. Analysis of a panel of microRNA marker molecules in the material of the cervical epithelium and calculation of the concentration ratios of “reciprocal” pairs is a promising method for prognosis of LSIL course.
Cervical cancer incidence in the Siberian Federal District
Authors: Zhuikova L. D. , Odintsova I. N. , Ananina О. A. , Pikalova L. V. , Lyakhova N. Р. 
Published: March 2021

Background. When planning preventive measures and providing specialized care, it is important to take into account the epidemiology of malignant neoplasms.Objective: to analyze the incidence of cervical cancer in 10 territories of the Siberian Federal District.Materials and methods. Based on the data of the Federal State Statistics Service, the incidence of cervical cancer and the quality of cancer care were analyzed in 10 cancer centers for the years 2005–2019. Results. During the study period, an increase in the incidence of cervical cancer was observed in the Siberian Federal District. The maximum increase in the incidence rate was observed in most territories of the Tyva Republic (102.3 %). The decrease in the incidence rate was recorded in the Altai Republic (–15.4 %) and Tomsk Oblast (–14.3 %). The age-specific incidence rates were stable in patients aged 65 years and older, and a 1.4-fold increase was observed in women of the reproductive age (20–44 years). The highest incidence rates were observed in the age groups 35–39 years (37.8 %) and 40–44 years (42.0 %). The improvement in the rates of quality of cancer care indicated the high proportion of morphologically verified cancers, early cancer detection and high proportion of patients who were followed up for 5 years or more. The rates of late-stage cervical cancer and one-year mortality remain high.Conclusions. From 2004 to 2019, an increase in the incidence of cervical cancer was observed in the female population of the Siberian Federal District. The highest risk of cervical cancer was observed in women of the reproductive age (20–44 years). It is necessary to develop and organize anti-cancer measures to improve cancer care