bluuebunny/crossref_metadata_2025 huggingface dataset:
Antioxidant potential and low-density lipoprotein cholesterol (LDL-c) uptake of
the black seed and honey mixture on human hepatocellular carcinoma (HepG2)
cells
Authors: Mohd Isa N.S. , Ng J.S. , Tufail Ahmad F. , Kassim M.N.I. , H. Norhayati , Yusof H.M.
Published: December 2021

High lipid levels especially low-density-lipoprotein cholesterol (LDL-c) are associated
with increased risk of cardiovascular (CVD) and coronary heart disease (CHD). Both
black seed (Nigella sativa L.) and honey are well-known in the hypolipidemic potential
and have CVD protective effects. In the present study, LDL-c uptake of the black seed and
honey mixture was tested on HepG2 cells. Antioxidant activities of black seed and honey
mixtures were determined through the 2, 2’-diphenyl-1-picrylhydrazyl (DPPH) assay. The
anticancer potential of black seed and honey mixtures in HepG2 cells was performed
using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cytotoxicity
assay. Black seed possessed the highest antioxidant activities with EC50 6.54 mg/mL as
compared to honey with EC50 value 9.56 mg/mL while the black seed and honey mixture
have EC50 between black seed and honey. From the results obtained, no synergistic effect
was observed in the mixtures as the EC50 values were within the range of black seed and
honey. Furthermore, no significant difference (p>0.05) among ratios (1:1, 2:1 and 1:2).
However, the decrease in cell proliferation was the highest in black seed and honey
mixture at 1:1 ratio (p<0.05) than individually treated black seed and honey. Thus, the
black seed and honey mixture at ratio 1:1 was the most potent anticancer agent with an
IC50 value of 7.44 μg/mL. The present study illustrated that black seed and honey mixtures
possess a lipid-lowering effect via LDL-c uptake in HepG2 cells (p<0.05). The highest
LDL-c uptake was observed at 15 μg/mL with the treatment of black seed and honey
mixture at 1:2 ratio which was 294.4%. Further studies should be conducted on primary
human liver cells to further justify the correlation between the antioxidant level and LDLc uptake mechanism of black seed and honey mixtures.
Effect of blanching, acid type, and temperature on the extraction of anthocyanin
from Tibouchina semidecandra flower
Authors: Daniella S. , Kartawiria I.S. , Marpaung A.M.
Published: December 2021

Extraction is the most common way to obtain anthocyanins from their natural matrices.
During the extraction, the anthocyanin may degrade due to the heat and acidic solvent. The
objectives of this research were to determine the best acidic aqueous solution and
temperature to extract anthocyanin from Tibouchina semidecandra flower and to decide if
the blanching process has a significant effect on the extracted anthocyanin. The T.
semidecandra petals were separated into two groups: steam blanched for 6 mins and
without blanching. Both were dried for 24 hrs at 45°C and powdered. The extract was
prepared by macerating the powdered petal into pH 3 aqueous solutions made of three
different acids (citric, malic, and hydrochloric acid, respectively) in a water bath shaker at
various temperatures (30, 45, 60, and 75°C) for an hour. The extracts were then filtered,
centrifuged, and analysed for their colour intensity, browning index, monomeric
anthocyanin, polymeric anthocyanin, and total phenolic content. The best method to obtain
the highest colour intensity, monomeric anthocyanin, total phenolic content, and lowest
browning index was using steam-blanched dried petal, citric or malic acid as solvent and
extraction temperature at 60°C. The total monomeric anthocyanin and phenolic content of
the extract was 3.63±0.35 mg/g dried petal and 74.47±11.47 mg/g dried petal, respectively.
Giving Birth on a Beach Women's Experiences of Using Virtual Reality in Labour A Pragmatic Mixed Methods Approach
Authors:   , Massov Lorna
Published: December 2021

Birth is a normal physiological process, and many women want a natural birth. However, there is worldwide concern over the increasing use of epidural analgesia and other pharmacological pain relief methods for women in labour. This tendency renders birth non-physiological by increasing the use of obstetric interventions with associated risks. Women use a range of non-pharmacological pain relief methods to reduce labour pain intensity, to help manage labour pain and to induce relaxation. The purpose of this study was to explore the experiences of women using virtual reality (VR) as a non-pharmacological method of pain relief in labour and to determine whether there was an effect on labour pain intensity. Virtual reality has been shown to be an effective distraction technique in other acute pain settings and also reduces anxiety.

This study used a pragmatic mixed method approach with a sequential exploratory design, combining in-depth antenatal and postnatal interviews with an intervention study in labour in a cross-over within-subjects trial. Thematic analysis was used to analyse the qualitative data.

Twenty-six pregnant women were recruited to the study. Fourteen participants reported their pain and had their heart rate and blood pressure measured during active labour while using and not using VR. There were significantly lower reported pain scores (6.14 compared to 7.61, p =<.001) and maternal heart rate (79.86 beats per minute compared to 85.57, p = .033) and mean arterial pressure (88.78 mmHg compared to 92.61 mmHg, p = .022) were lower when using VR during active labour. These differences were all statistically significant. Findings from qualitative postnatal interviews indicated a positive response to the use of VR in labour. Several themes were identified in the data. The first theme, Impact of VR on Labour, described the impact of VR on labour in terms of distraction, relaxation, enjoyment and a positive birth experience. The second theme, Managing the Pain, describes how VR was used by the women to manage their labour pain using breathing techniques and gaining a sense of control. In the third theme, The Challenges and Surprises of Using VR in Labour, women’s narratives recounted the various challenges of using the VR technology. Despite these challenges, ninety-four percent of women reported that they would use VR in labour again and would recommend it to a pregnant friend.

This study provides a unique and original contribution to the field of VR in labour and birth. It is consistent with other recent findings of reduced pain with the use of VR, and links decreased pain scales to heart rate and blood pressure, the physiological markers of pain. It also identifies VR as an acceptable and positive experience in the management of labour pain. Results from this study have the potential to inform design for future labour specific VR environments and expand its application in the field of biomedical technology.
Discreet Synthesizer Allowing new ambient music to emerge through composition on semi-modular synths
Authors:   , Waters Sonya
Published: December 2021

Defining ambient music through exploring the intentions, creative processes and listening objectives of ambient composers. Aspects that have influenced ambient music, loops, drones, environmental sound, aural architecture
Quality of Life as a Predictor of Psychological Distress and Self Esteem among Prisoners
Authors: Saeed Wizra , Irfan Saira , Nawab Sana , Amtullah
Published: December 2021

Purpose: One of the most vulnerable areas for poor mental health is prisons. This study was conducted to investigate whether quality of life predicts psychological distress and self-esteem among prisoners as well as to look at any gender differences that might exist.

Design/Methodology/Approach: This study utilized a correlational design carried through the survey method. A purposive sampling technique was used to collect the data from prisoners. The sample (N=200) included 100 male and 100 female prisoners. The sample was selected from Lahore, Faisalabad, Sahiwal, and Gujranwala jails. The age range of the participants was 20 to 50 (M = 38.12, SD=6.50). Data was collected through validated questionnaires.

Findings: Regression analysis indicates quality of life as a significant negative predictor of psychological distress and significant positive predictor of self-esteem. Compared to female prisoners, male prisoners have higher self-esteem and a better quality of life. Female prisoners have higher levels of psychological distress than male prisoners.

Implications/Originality/Value: These findings highlight the need to improve mental health services in prisons.
Pre-Service Teachers’ Computer Self-Efficacy and the Use of Computers
Authors: Chibisa Admire , Tshabalala Mswazi Gladson , Maphalala Mncedisi Christian
Published: December 2021

The purpose of this study was to examine the effects of pre-service teachers’ computer self-efficacy on their use of computers. The research used a quantitative design whose data were collected by using a structured five-point Likert scale questionnaire with responses ranging from 1(strongly agree) to 5(strongly disagree). Simple random sampling was used to select a representative sample of 400 participants from a population of 4000 pre-service teachers, of which 332 of them were successfully returned, yielding a response rate of 83%. The study employed the Technology-Acceptance Model with eight constructs, namely; demographic influence (DI), social influence (SI), basic computer skills (CS), access to computers (AC), perceived ease of use (PEOU), perceived usefulness (PU), computer self-efficacy (CSE), and actual computer use (AU). Factor analysis was used to analyse the data generated from the survey, with the help of PLS-SEM, using the SmartPLS software version 3.0. The findings of the study indicated that each of the identified factors in the model had a significant effect on CSE. In essence, the identified explanatory variables explained 73.7% of the variance in CSsE. The four independent variables explained 45.4% of the variance in PU of computers and 66.5% of the variance in PEOU of computer use. The CSE model also explained 60.6% of the variance in computer use. In order to develop a strong CSE for pre-service teachers, it is recommended that higher education institutions ensure that all students have access to the necessary computers, proper connectivity, and skilled technicians.
Assessing for Learning: Teacher Training in Practice Involving 14 Postgraduate Certificate in Education (PGCE) Students
Authors: du Plessis Elize E. C.
Published: December 2021

In this age of answerability, assessment is a dominant factor that can either promote or weaken learners’ education internationally. Yet many of the usual practices followed by institutions show that assessments in the classroom continue to be a challenge for teachers. This signifies that assessment is either not well understood or not done effectively during all stages of education. The study reported in this article attempted firstly to detect how prepared teachers were to perform assessments for learning, and secondly to enhance teachers’ assessment practices. It focused on the qualities of good assessment practices, different methods of assessment, types of assessment, and feedback and assessment to enhance learning in the classroom. A qualitative approach was used, involving 14 participants who had completed a postgraduate certificate in education (PGCE) at a distance teaching institution. Results revealed inter alia a need for longer teaching practice periods, the use of taxonomies on different cognitive levels, and subject-specific workshops. It is recommended that more practical examples, like lecture videos, taxonomies, and rubrics, should be employed, and assessment processes should embrace technology.
Predictors of Behavioural Intentions of Teachers to Adopt and Use Information and Communication Technologies in Secondary Schools in Zimbabwe
Authors: Rudhumbu Norman , Du Plessis Elizabeth , Mudau Patience Kelebogile
Published: December 2021

The use of information and communication technologies (ICTs) also known as educational technology in the teaching and learning context, has become a new normal in all sectors of education world-wide. The most important driver of the use of ICT in education has been the rapid advances in technology and to some extent, natural disasters such as COVID-19 that has affected access to education across all sectors of the education system. As a result, it has become very important that teachers in secondary schools adopt ICT for their teaching. This study therefore seeks to establish factors influencing the behavioural intentions of secondary school teachers to adopt ICT in Zimbabwe. A sample of 251 teachers were selected using stratified random sampling strategy from 10 secondary schools to participate in the study. A structured questionnaire adapted from the Oscarson Scale for Measuring Adoption-proneness (OSMA) was used for data collection. Results of the study showed that the use of technology in teaching, professional development, attitudes toward ICT, gender and ICT support services have a significant influence on the behavioural intentions of secondary school teachers to adopt ICT. A number of challenges that affected the adoption of ICT in secondary schools were also identified. The study has implications on both policy and practice with regard to the adoption of ICT in secondary schools.
“I Teach the way I believe”: EFL Teachers’ Pedagogical Beliefs in Technology Integration and its Relationship to Students’ Motivation and Engagement in the COVID 19 Pandemic Year
Authors: D’ Souza Russell , Shet Jayashree Premkumar , Alanya-Beltran Joel , Tongkachok Korakod , Hipolito-Pingol Geena , Mohamed Sameem Mohamed Aboobucker
Published: December 2021

This study aimed to investigate language teachers' pedagogical concepts and attitudes and the effect of these on students' motivation and engagement levels. Its results were based on a cross-sectional correlational research survey which was conducted online. The participants in the study were chosen at random from among 205 language teachers (n= 205) and 317 language students (n= 317) from various higher educational institutions in Asian countries. Results of the study of language teachers revealed that the respondents' pedagogical ideas and orientations were positive when it came to using technology-based teaching in their language classroom. Results of gender differences indicated that female language teachers showed a firmer belief in student-centered online language learning than their male counterparts. On the other hand, males are more likely than females to utilize technology in the language classroom, and their attitudes relating to it are more favorable than those of their female counterparts. The levels of language learning motivation and engagement among students were also investigated. The findings also showed a high level of language learning engagement among both male and female students. Furthermore, the test of relationship showed that the firmer the instructors' belief in the importance of student-centered teaching and the incorporation of technology in the language classroom, the more driven and engaged the students are in language learning. Students' motivation and involvement in online language learning are not related to their views about the significance of instructors in their life, which is contrary to what many people believe. When it comes to incorporating technology into language courses, there are several pedagogical assumptions that enable EFL teachers to do so effectively. More broadly stated, this study has implications for increasing language instructors' digital literacy to develop more motivating, productive, and engaging language courses for 21st-century learning to improve language students' digital literacy.
Improving Students’ Critical Thinking through Oral Questioning in Mathematics Teaching
Authors: Mahmud Muhammad Sofwan , Wan Pa Wan Ahmad Munsif , Zainal Mohd Syazwan , Mohd Drus Nadia Fasha
Published: December 2021

The use of effective oral questioning in the teaching of mathematics can stimulate students' thinking and encourage them to think critically. As a result, this study was carried out to identify the oral questions used by teachers when teaching mathematics. This can encourage students' critical thinking. This was a qualitative study in the form of a case study conducted in six schools in a Malaysian state with a total of six study participants. They were chosen on purpose based on the specific criteria set by the researcher. The data was collected using observation methods, interviews, and field notes to gain an in-depth picture of the phenomena studied. The study findings were analyzed using the continuous comparison method to identify the themes and subthemes involved. The researchers used several methods to improve the validity and reliability of this study, including triangulation, the consent of the study participants, peer reviews, audit trails, researcher bias, and a long period in the field. According to the study findings, mathematics teachers frequently use three types of oral questions to encourage their students to think critically: prompting questions, reflective questions, and clarification questions. These types of oral questions are effective at encouraging students to think critically when trying to solve mathematical problems. This study implies that teachers should use caution when asking oral questions so that the students' thinking is stimulated, rather than focusing on memorizing important mathematical algorithms and procedures.
The Autonomy of Indonesian EFL Students: A Mixed Method Investigation
Authors: Melvina M , Sri Lengkanawati Nenden , Wirza Yanty
Published: December 2021

The present study sought to scrutinize undergraduate EFL students’ learning autonomy in a state university in Indonesia. This study employed a triangulation study of mixed-method design by distributing questionnaires and conducting interviews to get quantitative and qualitative data. The questionnaire was distributed to 40 second year participants enrolled in listening, speaking, reading, and writing for academic purposes classes, whereas 15 participants were selected for the interview Descriptive statistics and thematic analysis were used to analyse the data collected from the questionnaire and the interview. Findings revealed that the level of students’ learner autonomy was classified as moderate level of autonomy. This indicated that Indonesian undergraduate students were considered somewhat autonomous learners. In addition, the Indonesian undergraduate students defined learner autonomy as independent learning with or without the teacher’s assistance, students responsible for their own learning, and learner autonomy was the student’s self-awareness and self-initiated to learn outside the classroom to find ways of learning and collaborate with others. The study recommended that teachers should consistently develop learner autonomy in their teaching practice.
The Use of Critical Thinking Activities through Workshops to improve EFL Learners' Speaking Skills
Authors: Pinza-Tapia Eliana , Toro Vanessa , Salcedo-Viteri Karina , Paredes Fabian
Published: December 2021

Speaking is considered to be the most complex skill to master by EFL (English as a foreign language) learners. Unfortunately, Ecuadorian students do not reach the desired speaking level. To address this issue, this mixed-method study aims at identifying the impact of critical thinking activities through workshops, in order to improve learners’ speaking skills.  This study was conducted at public high schools in the different provinces of Ecuador. The sample consisted of 635 students from the tenth grade of elementary school and the first and second grades of senior high school. The data-collection instruments were a pre-test, and a post-test, to find out the students´ CEFR speaking level, and an observation grid to discover students’ attitude and performance concerning oral communication skills. Additionally, five different workshops, based on the use of critical thinking activities were carried out. The results led us to the conclusion that critical thinking workshops have a positive impact on students’ speaking skills. They allowed students to use accurate grammar, vocabulary, and to improve their fluency and pronunciation, in order to communicate their ideas orally.
Recommendations to Improve the Usability of Mobile Learning for Preschool Teachers in Africa: A Systematic Scoping Review
Authors: de Wit Monique , Plastow Nicola Ann
Published: December 2021

Poor quality preschool teacher training is a significant contributor to children not achieving school readiness. With technological development, electronic and mobile learning offer accessible and affordable options for this training, however, there is a lack of design evidence for the African context. This interdisciplinary education- and computer-science study aims to provide evidence-based recommendations for improving the usability of mLearning modules for preschool teachers in Africa. A scoping review guided by Arksey and O’Malley’s framework, the PRISMA reporting guidelines for scoping reviews, and Levac et al. guidelines, was conducted. Databases searched included Africa Wide Information, ERIC, CIHNAL, and Academic Search Premier. Two researchers completed a blind-review process for article inclusion and framework analysis, using 10 usability attributes with inductive grouping of data under each attribute to form sub-categories. Overlapping themes were coded to formulate usability recommendations within WeftQDA. The search yielded 909 articles and, after title and abstract screening, 123 were selected for full text review. Seventeen articles (n=17) met the inclusion criteria and were included in the final review. All studies included an African partner, and largely included part-time learning for degree purposes and professional development using mLearning, eLearning, and videos. Nineteen recommendations were developed to improve the usability of mLearning training applications for preschool teachers in Africa, with contextual relevance emerging as a new usability attribute. Development of mLearning training modules for preschool teachers in Africa should include user centred design, heuristic evaluation and usability assessment, to ensure the sustainability of both mLearning and change in classroom teaching practices.
Las enfermedades respiratorias y los nuevos retos de la pediatría actual
Authors: Castro Poveda Michelle Andrea , Tapia Toral Mauro Miguel , Chan Macías Shuyin Bernarda , Chan Macías Miosoty Meylin , Guaigua López Silvia Marcela , Reinoso Tapia Stefanie Cristina , Salinas Martínez René David , Martínez Ruiz Gabriela Elizabeth , Vásquez Gaibor Andrés Alberto , Naranjo Albán Shesnarda Maritza
Published: December 2021

A inicios de esta tercera década del siglo XXI, la amenaza para la sobrevivencia de toda la especie humana, e incluso sobre el planeta tal como lo conocemos hoy, se ha hecho mucho más patente. El cambio climático se evidencia con enorme dureza en la cantidad de fenómenos atmosféricos que trascurren con inusual severidad, modificando los patrones de ocurrencia tanto geográficos como de periodicidad. Este año ocurrieron inundaciones en países de Europa por los elevados récords de pluviosidad, simultáneamente con las oleadas de calor, alcanzando temperaturas no registradas anteriormente, mientras en unas regiones los huracanes y en otras los tifones se presentaron con enorme poder destructivo. No es casualidad entonces que a finales de 2019 emergiera una inusual y extraordinaria amenaza que haría tambalear las capacidades de acción y reacción de muchos gobiernos y sociedades, que sin distingos de desarrollo industrial y riquezas, causara la mortalidad de millones de personas, obligando a dichos gobiernos a tomar decisiones que paralizarían las economías: la pandemia originada por la aparición de un nuevo Coronavirus en China, el SARS-CoV-2, causante de la enfermedad conocida como Covid-19. Este es el contexto en que se elabora el presente texto, destinado a refrescar la divulgación de conocimiento científico actualizado respecto a las infecciones respiratorias que atacan a los infantes a lo largo de los años, pero con mayor fuerza en determinadas temporadas y localidades.
Geç Dönem Osmanlı Mimarisinde Bölgesel Bir Süsleme: Bacini (Şanlıurfa Örnekleri Üzerinden Bir Değerlendirme)
Authors: POLAT Turgay
Published: December 2021

Bacini, en bilinen anlamıyla mimari eserlerin çeşitli yerlerine süsleme ve renk katmak maksadıyla seramik kapların yerleştirilmesiyle elde edilen bir süsleme tekniğidir. Avrupa’da 18. yüzyıldan itibaren keşfedilip yayınlanmaya başlanan bu teknik hakkında ülkemizde maalesef birkaç yayın dışında çalışma yapılmamıştır. Özellikle Avrupa’da yayınlanan çalışmalarda Anadolu’dan Selçuklu dönemine ait birkaç yapıya değinilerek Avrupa’daki örnekler detaylıca anlatılmaktadır. İlk ortaya çıkış yeri belli olmayan bu teknik ile Anadolu’da, Avrupa’daki kullanım şekillerinden bazı farklılıklar olmakla birlikte hem Selçuklu hem de Osmanlı dönemi eserlerinde karşılaşmak mümkündür. Osmanlı mimarisinde özellikle 18. yüzyıl ve sonrası gibi geç bir dönemde sadece belirli bir bölgede kullanılıyor olması da Osmanlı mimarisi içinde bölgesel etkenleri gözler önüne sermektedir. Ayrıca bu süslemelerde kullanılan seramiklerin üretim yerleri ve teknikleri dönemin ticari hayatı ve beğenileri gibi çeşitli alanlarda fikirler edinmemizi sağlamaktadır. Şanlıurfa’da Osmanlı camileri üzerinden bacini süslemeleri, ülkemizin Güney ve Güneydoğu’sunda yer alan Adıyaman, Gaziantep, Kahramanmaraş, Kilis ve Hatay gibi şehirlerdeki eserlerle birlikte anlatmak, Osmanlı mimari süslemesinde az bilinen bu tekniğin aslında oldukça yoğun bir kullanım alanına sahip olduğu ispatlanmış olacaktır.
Titration of weak base fibrous anion exchangers in the presence of complex-forming divalent cations
Authors: Soldatov V. S. , Shachenkova L. N. , Kasandrovich E. G. , Nesteronok P. V.
Published: December 2021

Curves of potentiometric titration of fully protonized fibrous ion exchangers with potassium hydroxide against the background of 1 M KCl in the presence of chlorides of Ni2+, Со2+, Сu2+ and Ca2+ were obtained. The ion exchangers were synthesized by modifying of industrial polyacrylonitrile fiber with diethylenetriamine and triethylenetetraamine and predominantly contained functional groups R-CO-NH- (CH2CH2NH)nH (n = 2 or 3) and a small amount of carboxyl groups. The sorption of Ni2+, Со2+, Сu2+ и Ca2+by ion exchangers was calculated from the data obtained depending on the pH of the medium. It was found that the investigated ion exchangers with high selectivity sorb heavy metal ions in a wide range of acidity of solutions (pH 2–9) due to the formation of metal-polymer complexes with polyamine functional groups. The maximum sorption capacity is 1.5–2.7 and 4–5 meq/g for ion exchangers with n = 2 and 3, respectively.
On water solubility of С17–С24 alkylbenzolsulphoic acids used as an additive to motor oils
Authors: Karpinchik E. V. , Yuzhik L. I. , AgabekovInstitute V. E.
Published: December 2021

Using the nephelometric method, the water solubility of C17–C24 alkylbenzenesulfonic acids has been studied. The results of the study made it possible to develop a technique for measuring the solubility of alkylbenzenesulfonic acids used in the production of additives for motor oils. Using the methodology in scientific and industrial laboratories, it is possible to determine the content of ABSA in mixtures with water and to qualify this substance according to the criterion of water solubility when assigning the appropriate code in the Commodity Nomenclature of Foreign Economic Activity.
Nanocomposites based on apatitic tricalcium phosphate and autofibrin
Authors: Glazov I. E. , Krut’ko V. K. , Vlasov R. A. , Musskaya O. N. , Kulak A. I.
Published: December 2021

Nanocomposites based on apatitic tricalcium phosphate in an autofibrin matrix were obtained by precipitation at a Ca/P ratio of 1.50, pH 9 and a maturation time from 30 min to 7–14 days. The resorbability of nanocomposites was determined by the composition of calcium phosphates, which, during long-term maturation, formed as the calcium-deficient hydroxyapatite with a Ca/P ratio of 1.66, whereas biopolymer matrix favored the formation of more soluble calcium phosphates with a Ca/P ratio of 1.53–1.59. It was found that the fibrin clot stabilized, along with apatitic tricalcium phosphate, the phase of amorphous calcium phosphate, which after 800 °C was transformed into resorbable α-tricalcium phosphate. Citrated plasma inhibited the conversion of apatitic tricalcium phosphate into stoichiometric hydroxyapatite, which also facilitated the formation of resorbable β-tricalcium phosphate after 800 °C. The combined effect of the maturation time and the biopolymer matrix determined the composition, physicochemical and morphological properties of nanocomposites and the possibililty to control its extent of resorption
Synthesis of chalcone-based pyrimidine derivatives and their antimicrobial activity
Authors: Martsinkevich D. S. , Chernyavskaya K. F. , Tarasevich V. A.
Published: December 2021

A series of substituted chalcones and pyrimidine derivatives on their base was synthesized. Obtained compounds were tested for antimicrobial activity and ability to increase activity of known antimicrobial substances. Pyrimidine products shown good activity against Staphylococcus aureus and Candida tropicalis. These compounds also could increase activity of modified polyguanidines against Staphylococcus aureus.
Preparation and characterization of recombinant human glutathione transferase P1 and screening of novel enzyme inhibitors
Authors: Gilevich S. N. , Brechka Yu. V.
Published: December 2021

Human glutathione transferase P1 (GSTP1) plays an important role in the second phase of xenobiotic biotransformation and in the regulation of apoptotic signal pathways. Directed screening of new enzyme inhibitors is an actual task since selective suppression of GSTP1 activity in tumor cells may substantially increase their sensitivity to chemotherapy. Known methods to obtain recombinant GSTP1 with a hexahistidine tag in the structure are complex, laborious, and suffer from significant losses of the enzyme activity. With the aim to create a simple and effective bacterial expression system for tagless GSTP1 posessing native structure and high activity, in the present work the full-length gstp1 gene was cloned into the pTXB1 plasmid vector, followed by transformation of E. coli cells. The optimized expression level amounted to 30–32 mg of the enzyme per liter of broth. Using glutathione-containing affinity membranes, the purified enzyme was isolated from bacterial lysate with the yield of 75.7 % and specific activity of 102.6 U/mg protein. The enzyme homogeneity was confirmed by gel-electrophoretic and mass-spectrometric data. Physico-chemical and catalytic properties of recombinant GSTP1 practically coincided with those of the native erythrocytary enzyme. The results of in silico and in vitro screening allowed to reveal structural factors and interactions determining the efficiency of the enzyme inhibition by carbocyclic and N-heterocyclic ligands. The preferable orientation of “good” inhibitors in the GSTP1 H-site was also established. Three strong enzyme inhibitors were found: 1,10-phenanthroline-5,6-dione, Alizarin Red S, and indigo carmine, with their respective IC50values of 31, 16 and 2.3 μM. The new inhibitors are of certain interest for the development of novel lead structures with potential antitumor activity.
Synthesis of new thiazolo[3,2-a]pyrimidine derivatives and in silico analysis of their bioactivity
Authors: Mineeva I. V. , Faletrov Y. V. , Starovoytova V. A. , Shkumatov V. M.
Published: December 2021

An effective method of synthesis thiazolo[3,2-a]pyrimidine derivatives was developed and the compounds with n-pentyl or β-acetoxycyclopropyl as well as fluorescent benzo[f]coumarin substituents were obtained with yields 60 % and more. Using computational (in silico) approaches we demonstrated the ability of the obtained compounds to permeate lipid bilayer as well as their affinity to some protein kinases (compounds 4 and 6 bind with a protein kinase AKT1 with PDB code 3о96; Autodock Vina-computed energy of binding (Ebind) values were -10.9 and -10.6 kcal/mol, respectively), acethylcholine esterase and some human cytochromes P450 (for P450 3A4, pdb 5vcd, Ebind -12.3 kcal/mol).
Heat-insulating porous material based on glauconite-containing sands and aleurites of the Novodvorskoye deposit of the Republic of Belarus
Authors: Barantseva S. E. , Pazniak A. I. , Klimosh Y. A. , Azaranka I. M. , Hundzilovich N. N. , Pospelov A. V.
Published: December 2021

The results on the research of heat-insulating porous ceramic materials produced using overburden rocks of the Novodvorsk deposit of Pinsk district of the Brest region as the main component of raw materials are presented in the study and the use of bulk rock consisting of glauconite sands and aleurites is recommended. Low-melting clay, basalt and a blowing agent are used as additional components, rational combination of which would ensure the forming ability of ceramic masses and the required set of the physicochemical properties of the material. The dependence of the bulk density, swelling coefficient, coefficient of thermal conductivity on the chemical and mineral composition of the used and raw materials is established, wich is the criteria for choosing composition with the maximum use of overburden and the necessary plasticity of the ceramic mass required for the molding process of raw granules. The obtained results can serve as a basis for the large-scale use of not only the minerals of the Novodvorsk deposit (basalts and tuffs), but also associated – glauconite-containing overburden. This will make a significant contribution to the expanding the mineral resource base of the Republic of Belarus.
Surface and optical properties of calcium carbonate paper
Authors: Ismailov I. I. , Babakhanova Kh. A. , Sadriddinov A. A. , Babahanova M. A. , Saidova D. Sh.
Published: December 2021

The article investigates the surface and optical properties of calcium carbonate paper obtained at the UzbekChinese enterprise Fergana stone paper company (Uzbekistan), in order to identify the possibility of their use at printing enterprises for printing multicolor products using traditional printing methods. According to the results of a quantitative assessment of the surface quality by the indirect Beck method, we can say that paper sample 1 has a smoothness like coated paper (750–1500 s), paper samples 2 and 3 – like calendered paper, so that these paper samples can be recommended for prints with increased quality requirements. Smaller values of roughness Ra and small depressions, expressed by darkening in the topographic AFM images, characterized sufficient homogeneity and density of the structure. It was also revealed that the surface of the paper samples has a high ability to specularly reflect the incident light, since the percentage of surface reflection is similar to that of coated papers. Samples of paper have a whiteness of about 90 % and do not have a tint, since the difference between the maximum and minimum values of the reflection coefficients on a white stack is not more than 10 %. The tested paper samples can be recommended without restrictions for double-sided printing, since the opacity index is more than 92 %.
Protective Langmuir–Blodgett coatings based on long-chain fatty acids
Authors: Akulova V. M. , Salamianski A. E. , Melnikova G. B. , Nekrashevich D. A. , Sinkevich Yu. V. , Chishankov I. G. , Agabekov V. E.
Published: December 2021

The morphology and tribotechnical properties of Langmuir–Blodgett (LB) monolayers and multilayers of some fatty acids, such as nervonic (NA), cerotic (CA) and montanic acids (OCA), was investigated. It was established that the wear resistance of silicon surface coated by LB monolayer of OCA is greater by 11 and 1.3 times in comparison with the LB monomolecular films of NA and CA, respectively. The multilayer of OCA, formed by 140 layers, increases the stability of steel surface by 35 times.
Enzymatic hydrolysis of plant raw materials: state and prospects
Authors: Boltovsky V. S.
Published: December 2021

Plant raw materials are practically an inexhaustible natural resource, since they are constantly renewed in the process of plant photosynthesis, which determines the prospects for their use for industrial processing in various ways, including hydrolytic. The main biopolymer components of plant biomass in terms of their quantitative content are polysaccharides, the hydrolytic processing of which by acidic or enzymatic hydrolysis leads to the formation of monosaccharides and various products obtained from them. This review of scientific literature analyzes theoretical concepts and the current state of research on the development, improvement and prospects for the use of enzymatic hydrolysis of plant raw materials. The efficiency of this process and the composition of the resulting products largely depend on the features of the supramolecular structure of cellulose, the content of hemicelluloses and lignin in the raw material, the balance and activity of the cellulase complex of enzymes. It is shown that the main directions of development and improvement of the processes of enzymatic hydrolysis of plant raw materials at present are the production and use of more effective strains of microorganisms that produce highly active enzymes, the directed creation of complex enzymes (hydrolyzing not only cellulose, but also hemicellulose, as well as destroying lignin), the development of methods for pretreatment of raw materials to increase the reactivity of cellulose and remove lignin and improve the processes of fermentolysis.
Blood serum myokine irisin and adipocytokine levels in newborns small for gestational age at birth
Authors: Prylutskaya V. A. , Sukalo A. V. , Goncharik A. V.
Published: December 2021

In recent years, a number of the studies of myokine irisin in adults and isolated in newborns have been carried out. The role of adipocytokines in the growth and development of the fetus and children has been shown.

The aim of the study was to assess the levels of myokine irisin and adipocytokines in newborns small for gestational age at birth and to analyze the relationship between the parameters of the hormonal status of children and their mothers.

49 newborns and their mothers were examined. Two groups were identified: group 1 (Gr1) – newborns small for gestational age (n = 24), group 2 (Gr2) – newborns appropriate for gestational age (n = 25). The levels of irisin and adipocytokines in the blood serum were determined by the enzyme immunoassay.

Newborns small for gestational age had significantly lower levels of leptin and IGF-1 in the umbilical cord blood compared to children with physical development corresponding to the gestational age. There were no significant differences in the irisin content of cord blood serum in newborn Gr1 compared with Gr2. The presence of significant positive correlations between the level of irisin in the umbilical cord blood of newborns small for gestational age and the body weight at birth was established. In Gr1, a positive relationship was found between the irisin levels of mothers and newborns (r = 0.518, p = 0.028). The differences in the irisin content between the groups were established, taking into account the delivery mode (p = 0.0104).

The revealed statistically significant differences in the concentrations of the analyzed metabolic markers in mother–child pairs, their relationship with clinical and anthropometric parameters substantiate the possibility of using irisin and adipocytokines as predictors in predicting the formation of metabolic disorders of infants small for gestational age.
Pulmonary fibrosis as an outcome of COVID-19 pneumonia
Authors: Kalenchic T. I. , Kabak S L. , Korenevskaya I. V.
Published: December 2021

In this study, we report three cases of persistent  severe respiratory failure and radiological signs of diffuse pulmonary fibrosis in patients after COVID-19 related pneumonia. Chest CT criteria for a diagnosis of pulmonary fibrosis include the presence of traction bronchiectasis and parenchymal bands (linear opacities), as well as numerous small subpleural cystic air spaces (honeycombing). The study found that all cases of fibrosis were associated with such risk factors as male gender, old age, and multicomorbidity. Chest CT of one patient with acute respiratory distress syndrome showed radiographic characteristics of pulmonary fibrosis together with the presence of ground glass opacities (GGO) – the main CT feature of COVID-19 pneumonia. In two other patients, CT features of pulmonary fibrosis appeared in about 2 months after the hospital stay.

Thus, pulmonary fibrosis is severe and rapidly progressive complication of COVID-19 pneumonia with a poor prognosis, especially in patients with multiple risk factors.
Features of engraftment and rejection of ear alatransplants in laboratory rats
Authors: Astrowski A. A. , Raduta H. F. , Bakunovich A. A. , Yarashenka Yu. V. , Shuryberka A. V. , Shatrova V. O. , Buko V. U. , Semenenya I. N.
Published: December 2021

A method for revealing genetic affinity between laboratory rats has been developed, which is based on the transplantation of ear skin-chondrocyte allografts onto the surface of a full-thickness skin defect. On the example of Wistar rats (laboratory rats were taken from three research institutes), it was shown that the rejection of allografts occurs in the interval between 8 and 21 days with the same genetic differences that existed between the animals. However, at the same time, only those structures of ear allografts such as the dermis, epidermis and its derivatives die and are rejected, but the layers of chondrocytes are submerged under the granulation tissue and remain in a viable position for at least 210 days. The latter phenomenon is probably due to the membranes that cover the chondrocytes and act as an immunological barrier.
Study of the correlation between the clinical manifestations of the inflammatory periodontal diseases and the microbiome of periodontal pathogenic microflora in young representatives of a mixed population of the European region
Authors: Tikhomirova E. A. , Zudina I. V. , Slazhneva E. S. , Orekhova L. Yu. , Denisova Yu. L. , Rubnikovich S. P. , Loboda E. S. , Atrushkevich V. G.
Published: December 2021

The age of inflammatory periodontal disease (PD) manifestations has tended to decrease over the past decades. The study of the range of periodontal pathogens in young people and their influence on the PD manifestation contributes to the predictor identification for the early prevention of this pathology.

The aim was to study the correlation between the range of periodontal pathogens in the dentoalveolar sulcus/periodontal pocket (DS/PC) contents and the clinical PD manifestations in young people.

We examined 28 patients (23.1 ± 0.93 years) with dental biofilm-induced gingivitis (BG), 24 patients (30.7 ± 0.6 years) with aggressive periodontitis (AgP), and 87 clinically periodontally healthy patients (21.1 ± 0.49 years) (Control). The hygiene index and the periodontal status were determined in all patients. DNA of five periodontal pathogens was identified by PCR in the DS/PC contents. The statistical analysis was performed in Statistica 13.3. The critical significance level was p ≤ 0.05.

DNA was not observed in 60.9 % of the control group samples and 7.1 % of the BG group samples. In other cases, the bacteria were found separately and as part of bacterial complexes. P.g. and T.f. were most often detected in all groups. P.g. (U = 474, р < 0.01) and A.a. (U = 209, р >< 0.05) significantly contributed to the plaque formation in the control group, T.d. – in BG and AgP groups (U = 37.5, р >< 0.05 and U = 34, р >< 0.05, respectively). In the AgP group, purulent discharge was more often recorded if T.d. was detected in the PC contents (χ2  = 5.53, р >< 0.05). T.f. + P.i. and P.g. + T.f. + P.i. complexes were exclusively associated with PD. Complexes of four bacteria were found only in the AgP group. The association of periodontal pathogens and their complexes with different PD forms was revealed.>< 0.01) and A.a. (U = 209, р <0.05) significantly contributed to the plaque formation in the control group, T.d. – in BG and AgP groups (U = 37.5, р <0.05 and U = 34, р <0.05, respectively). In the AgP group, purulent discharge was more often recorded if T.d. was detected in the PC contents (χ2  = 5.53, р <0.05). T.f. + P.i. and P.g. + T.f. + P.i. complexes were exclusively associated with PD. Complexes of four bacteria were found only in the AgP group.

The association of periodontal pathogens and their complexes with different PD forms was revealed.
Characteristics and features of the formation of humoral immunity after immunization with Sputnik V and Vero Cell vaccines
Authors: Amvrosieva T. V. , Belskaya I. V. , Bohush Z. F. , Paklonskaya N. V. , Kaltunova Yu. B. , Kazinetz O. N.
Published: December 2021

The presented work contains an analysis of seroprevalence, tension, and duration of post-vaccination immunity to the SARS-CoV-2 coronavirus in the residents of the Republic of Belarus after immunization with two vaccine preparations available in the country: Sputnik V and Vero Cell.

It was found that seroconversion after the injection of the Vero Cell vaccine occurred significantly later than after the Sputnik V vaccine (p < 0.001). Nevertheless, two-stage immunization with the vaccines provided a sufficiently high efficiency of the inoculated antibodies to the S protein of the COVID-19 pathogen: the proportion of seropositive persons reached 99.19 [96.89; 99.97] % for Sputnik V and 96.03 [90.81; 98.53] % for Vero Cell. The efficiency of antibody formation after immunization with the Vero Cell vaccine was lower in older persons (in the group > 65 years). The proportion of individuals with the highest IgG score for the SARS-CoV-2 S protein was higher after the Sputnik V administration compared to that in response to the Vero Cell vaccine (p < 0.05), and gradually decreased over time. However, no significant decrease in the level of seropositive individuals after 90 days from the start of immunization with the both vaccine preparations was detected. In COVID-19 survivors immunized with the Sputnik V vaccine, the quantitative indicators of post-vaccination antibodies reached their peak values after 1 dose of the vaccine. The obtained results complement the accumulated world science and practical information on the problem of the postvaccination immunity formation in the context of the use of different drugs against COVID-19.>< 0.001). Nevertheless, two-stage immunization with the vaccines provided a sufficiently high efficiency of the inoculated antibodies to the S protein of the COVID-19 pathogen: the proportion of seropositive persons reached 99.19 [96.89; 99.97] % for Sputnik V and 96.03 [90.81; 98.53] % for Vero Cell. The efficiency of antibody formation after immunization with the Vero Cell vaccine was lower in older persons (in the group > 65 years). The proportion of individuals with the highest IgG score for the SARS-CoV-2 S protein was higher after the Sputnik V administration compared to that in response to the Vero Cell vaccine (p < 0.05), and gradually decreased over time. However, no significant decrease in the level of seropositive individuals after 90 days from the start of immunization with the both vaccine preparations was detected. In COVID-19 survivors immunized with the Sputnik V vaccine, the quantitative indicators of post-vaccination antibodies reached their peak values after 1 dose of the vaccine.

The obtained results complement the accumulated world science and practical information on the problem of the postvaccination immunity formation in the context of the use of different drugs against COVID-19.