bluuebunny/crossref_metadata_2025 huggingface dataset:
Risk models and scores for metabolic syndrome: a systematic review
Authors: Ibrahim Musa Saulawa , Pang Dong , Pappas Yannis , Randhawa Gurch
Published: November 2020

Background: Metabolic syndrome - ‘a clustering of risk factors which includes hypertension, central obesity, impaired glucose metabolism with insulin resistance, and dyslipidaemia’ is linked with increased risk of CVD, T2DM and all-cause mortality. Despite the high number of models and scores for assessing the risk of developing MetS, there is hardly any used in research or practical setting. Hence, we conducted a systematic review to determine the performance of risk models and scores for predicting MetS.Methods: Following the methods proposed by EPPI-Centre, we systematically searched MEDLINE, CINAHL, PUBMED and Web of Science to identify studies that either derive or validate risk models or scores for predicting the risk of MetS. Search was originally done in September 2018 and updated in September 2020. Data concerning models’ statistical properties as well as details of internal or external validations were extracted. Tables were used to compare various components of models and statistical properties. Finally, PROBAST was used to assess the methodological quality (risk of bias) of included studies.Results: A total of 27 studies reporting about the development, validation or both of MetS risk models were included. There is significant heterogeneity between studies in terms of geography/demographics, data type and methodological approach. Majority of the models or risk scores were developed or validated using data from cross-sectional studies, or routine data. Various combinations of risk factors (predictors) were considered significant in the respective final model. Similarly, different criteria were used in the diagnosis of MetS, but, NCEP criteria including its modified versions were by far the most widely used (32.5%). There is generally poor reporting quality across the studies, especially concerning statistical data. Any form of internal validation is either not conducted, or not reported in nearly a fifth of the studies. Only two (2) risk models or scores were externally validatedConclusions: There is an abundance of MetS models in the literature. But, their usefulness is doubtful, due to limitations in methodology, poor reporting and lack of external validation and impact studies. Therefore, researchers in the future should focus more on externally validating/ applying such models in a different setting.Protocol:The protocol of this study can be found at https://bmjopen.bmj.com/content/9/9/e027326PROSPERO registration number CRD42019139326
Serious non-fatal unintentional injuries among in-school adolescents in Sri Lanka: results from the 2016 Sri Lankan Global School-Based Health Survey
Authors: Wickramasinghe Sashimali , Gunawardena Nalika , Punyadasa Dhanusha , Gunawardena Shanthi , Wickramasinghe Champika , Lokubalasooriya Ayesha , Peiris Renuka , Senanayake Sameera
Published: November 2020

Background Unintentional injuries among adolescents is a major public health problem the world over. A great majority of the annual deaths among adolescents is due to unintentional injuries; it is also the leading cause of death among adolescents in the world. The aim of this study was to estimate the incidence of injuries and their associated factors among school going adolescents aged 13-17 years using data from the most recent Global School-Based Health Survey (GSHS) conducted in Sri Lanka.Methods A cross-sectional survey was conducted using a self-administered questionnaire, among 3,262 adolescents attending government schools. The sample was selected through a two-staged cluster sampling technique. In the first stage, 40 schools were selected using probabilities proportional to school enrollment size, from all schools in the country that have classes in grades 8-12. Then, from the selected schools, classes were selected using systematic equal probability sampling with a random start. The weighted prevalence was calculated, and logistic regression analysis was conducted in order to determine the correlates.Results During the 12 months before the survey, 35.8% (95% CI-30.7 - 41.1) of the students reported being seriously injured one or more times. The injuries were more common among males, but were equally common among the two different age groups (13-15 age group vs 16-17 age group). The most common type of injury was cut or stab wounds (5.5%), followed by broken bones/dislocated joints (5.3%). Multivariable analysis revealed that only a few factors were associated with injury, such as being of the male sex, being bullied, being physically attacked, and/or being in a physical fight.Conclusion This study demonstrated that the prevalence of serious unintentional injuries among school going adolescents is a major public health problem in Sri Lanka. This timely and comprehensive survey would help policy makers and researchers identify the unmet needs related to adolescent injuries. Furthermore, evidence generated form the study should be given due consideration when designing school-based interventions to prevent adolescent injuries.
Influence of Orthodontic Treatment with Premolar Extraction on the Spatial Position of Maxillary Third Molars in Adult Patients: A Retrospective Cohort Cone-bean Computed Tomography Study
Authors: Pan Fangwei , Yang Zhentao , Wang Jian , Cai Ruilie , Liu Jialing , Zhang Chenghao , Liao Wen
Published: November 2020

Background: Based on low-dose radiation Cone-bean computed tomography (CBCT) images, This study aims to establish a space coordinate system, which offers more precise and comparable evaluation on changes of maxillary third molars influenced by orthodontic treatment with premolar extraction in adults. The system suggests promising application prospect in future studies related to CBCT superimposition and evaluation for its feasibility and efficiency.Methods: Forty-nine maxillary third molars from 27 patients (mean age, 20.78 years) were included. CBCT images were obtained before and after orthodontic treatment with premolars extracted (mean treatment duration, 31.47 months). The changes in the position, angulation, and rotation of the third molars were evaluated with a space coordinate system using four landmarks: anterior nasal spine (ANS), posterior nasal spine (PNS), left and right orbitales.Results: After orthodontic treatment, the third molars moved forward (adjusted mean, 1.44 mm) (p < 0.001) and downward (adjusted mean, 2.87 mm) (p < 0.001) accompanied by outward rotation of the crowns (adjusted mean, 5.38°) (p = 0.001), while changes in angulation were insignificant.Conclusions: This was the first study to systematically investigate the spatial position change of maxillary third molars in adult patients who received orthodontic treatment with premolar extraction. During the process, maxillary third molars moved downward and forward accompanied by outward rotation of the crowns. Orthodontists should take tooth movement potential into consideration when making extraction plans.
Anthropometric changes in children under 7 years old in Nanjing, China from 1995 to 2015
Authors: Chen Ling , Chen Ying , Dong Jing , Li Xi Ling , Yao Tian Hong , Li Yue , Tong Mei Ling , Zhang Min
Published: November 2020

Background: To date, there have been several reports about long-term changes in physical growth in children of different races around the world. However, limited studies on this change have been reported in Nanjing, China. We decided to assess long-term changes in body weight, length/height and head circumference in children (0-7 years old) in Nanjing over the past two decades from 1995 to 2015 and the relationship between socioeconomic development and the change of physical growth.Methods: The results for body weight, length/height and head circumference in 0-to 7-year-old children were obtained from three repeated cross-sectional surveys that were performed by using the same methods in the same urban and suburban areas of Nanjing in 1995, 2005 and 2015. The differences in mean values between urban and suburban boys and girls and the increases per decade were compared. Socioeconomic indicators were collected and analysed.Results: There was positive long-term growth in height and weight of children in Nanjing from 1995 to 2015, measurements increased 0.3-3.00 kg in weight and 1.0-3.8 cm in height for boys, 0.23-2.18 kg in weight and 1.3-3.6 cm in height for girls in urban areas (except children under 15 months), as well as 0.32-4.15 kg in weight and 1.1-7.4 cm in height for boys, 0.26-2.95 kg in weight and 1.2-6.3 cm in height for girls in suburban areas (except children under 8 months). Compared with the first decade, the changes of mean values in height and weight of urban children in the second decade were smaller. In contrast, the long-term change of suburban children still kept fast growth rate. Before 2.5 years old, negative increases in weight and height in urban children were observed in second decade. Urban-suburban difference of weight and height became smaller in 2015. The growth of head circumference from 1995 to 2015 underwent a small long-term change, especially of urban children. Conclusion: The increased long-term physical growth due to rapid social and economic development would disappear, and genetic potential might have been seen.
Mesenchymal Stem Cells Secreted-Prostaglandin E2 Ameliorates Acute Liver Failure via Attenuation Cell Death and Regulation of Macrophage Polarization
Authors: Wang Jinglin , Liu Yang , Ding Haoran , Shi Xiaolei , Ren Haozhen
Published: November 2020

Background: Acute liver failure (ALF) is an acute inflammatory liver disease with high mortality. Previous preclinical and clinical trials have confirmed that mesenchymal stem cell (MSC) is a promising therapeutic approach, however the effect is not satisfied as the underlying molecular mechanisms of MSC in treating ALF remain unclear.Methods: MSC isolated from 4- to 6-week-old C57BL/6 mice were used to treat ALF. Histological and serological parameters were analyzed to evaluate the efficacy of MSC. We explored the molecular mechanism of MSC in the treatment of ALF by detecting liver inflammatory response and hepatocyte death.Results: In this study, we found that therapeutic potential of MSC on ALF dependent on secretion of prostaglandin E2 (PGE2), a bioactive lipid. MSC-derived PGE2 inhibited TGF-β-activated kinase 1 (TAK1) signaling and NLRP3 inflammasome activation in liver macrophages to decrease the production of inflammatory cytokines. Meanwhile, macrophages in liver could be induced to anti-inflammatory (M2) macrophages by MSC-derived PGE2 via STAT6 and mechanistic target of rapamycin (mTOR) signaling, which then to promote inflammatory resolution and limit liver injury. Finally, administrating of EP4 antagonist significantly ameliorated the therapeutic ability of MSC, which promoted liver inflammation and decreased M2 macrophages.Conclusions: Our results indicate that PGE2 might be a novel important mediator of MSC on treating ALF, which through inhibiting liver inflammatory response and hepatocyte death.
Pathological Responses to Low-Dose Irradiation and Pepleomycin in Oral Squamous Cell Carcinoma are Predictive of Locoregional Control
Authors: Katagiri Tomohiro , Ohyama Yoshio , Miyamoto Hideo , Egawa Yuki , Moriki Toshiaki , Hasegawa Kazuki
Published: November 2020

BackgroundThe prognosis of advanced oral cancer remains dismal. While multimodal therapy is beneficial, maintaining the quality of life of long-term survivors is important. Therefore, risk-adapted treatment regimens need to be designed. We herein investigated whether pathological responses in oral cancer patients treated with preoperative chemoradiotherapy predict locoregional recurrence.MethodsWe retrospectively reviewed the data of 51 oral cancer patients who received preoperative radiotherapy and concurrent pepleomycin, followed by curative surgery at our institution between January 2009 and June 2018. Each patient received preoperative external beam irradiation to the primary tumor and lymphatics (2 Gy per day for approximately 3 weeks) concurrent with pepleomycin (2.5 mg/day). Surgery was performed approximately 3-4 weeks after the completion of preoperative chemoradiotherapy. Pathological responses were defined based on the grading system of Oboshi and Shimosato.ResultsEight, 22, 16, and 5 patients had Oboshi and Shimosato grades 2a, 2b, 3, and 4, respectively. Favorable pathological responses (grades 3 and 4) were observed in 41.2% of patients (21 out of 51 patients). The pathological response and number of pathological lymph node metastases were identified as signiﬁcant prognostic factors for locoregional control in the univariate analysis. Three-year locoregional control rates were 100% and 56.6% in patients with favorable and unfavorable pathological responses, respectively.ConclusionsThe present study demonstrated that pathological tumor responses to preoperative chemoradiotherapy are a useful predictive factor for locoregional control.
DeepEnzyPred: A Bi-Layered Deep Learning Framework for prediction of Bacteriophage Enzymes and their Sub-Hydrolases Enzymes via Novel Multi Level- Multi Thresholds Feature Selection technique
Authors: Wang Yu , KHAN ZAHEER ULLAH , Ali Shaukat , Hayat Maqsood
Published: November 2020

BackgroundBacteriophage or phage is a type of virus that replicates itself inside bacteria. It consist of genetic material surrounded by a protein structure. Bacteriophage plays a vital role in the domain of phage therapy and genetic engineering. Phage and hydrolases enzyme proteins have a significant impact on the cure of pathogenic bacterial infections and disease treatment. Accurate identification of bacteriophage proteins is important in the host subcellular localization for further understanding of the interaction between phage, hydrolases, and in designing antibacterial drugs. Looking at the significance of Bacteriophage proteins, besides wet laboratory-based methods several computational models have been developed so far. However, the performance was not considerable due to inefficient feature schemes, redundancy, noise, and lack of an intelligent learning engine. Therefore we have developed an anovative bi-layered model name DeepEnzyPred. A Hybrid feature vector was obtained via a novel Multi-Level Multi-Threshold subset feature selection (MLMT-SFS) algorithm. A two-dimensional convolutional neural network was adopted as a baseline classifier.ResultsA conductive hybrid feature was obtained via a serial combination of CTD and KSAACGP features. The optimum feature was selected via a Novel Multi-Level Multi-Threshold Subset Feature selection algorithm. Over 5-fold jackknife cross-validation, an accuracy of 91.6 %, Sensitivity of 63.39%, Specificity 95.72%, MCC of 0.6049, and ROC value of 0.8772 over Layer-1 were recorded respectively. Similarly, the underline model obtained an Accuracy of 96.05%, Sensitivity of 96.22%, Specificity of 95.91%, MCC of 0.9219, and ROC value of 0.9899 over layer-2 respectivily.ConclusionThis paper presents a robust and effective classification model was developed for bacteriophage and their types. Primitive features were extracted via CTD and KSAACGP. A novel method (MLMT-SFS ) was devised for yielding optimum hybrid feature space out of primitive features. The result drew over hybrid feature space and 2D-CNN shown an excellent classification. Based on the recorded results, we believe that the developed predictor will be a valuable resource for large scale discrimination of unknown Phage and hydrolase enzymes in particular and new antibacterial drug design in pharmaceutical companies in general.
A qualitative assessment of the sexual-health education, training and service needs of young adults in Tehran
Authors: Sheikhansari Narges , Abraham Charles , Denford Sarah , Eftekhar Mehrdad
Published: November 2020

Background: Sexual Health and Relationships Education (SHRE) provides individuals with the knowledge and skills set which helps them to manage risky behaviors and take informed decisions and to protect themselves against STIs, risky behavior and unintended pregnancy. Such education is minimally provided in Iranian schools and universities and previous research has indicated demand and need for SHRE among different social groups. This study explored Iranian young adults’ sexual health education, training and service needs and ways to improve or augment the existing provision.Design and methods: A qualitative design was employed. Semi-structured interviews were conducted with a sample of 25 young adults who lived in Tehran, Iran and have volunteered to participate in our study. Transcripts were analyzed using thematic analysis.Results: Participants explained their need and demand for sexual health education and healthcare. They highlighted existing barriers such as lack of reliable resources, taboo and cultural barriers and lack of trust and protected confidentiality to gaining sexual health information and seeking related advice and healthcare. This has resulted in ambiguities and misconceptions, including those regarding the cause and transmission of STIs and correct use of contraceptions.They unanimously expressed their dissatisfaction with the limitedly available sexual health education and provided recommendations for an improved provision, including holding mixed gender extracurricular workshops with a comprehensive approach to sexual health and relationships education.Conclusions: There is a clear need and demand for provision of relevant and reliable sexual health and relationships education to young adults, which needs to be addressed in order for young adults to make informed choices and limit their risky sexual behavior.
Subcutaneous nanotherapy repurposes the immunosuppressive mechanism of rapamycin to enhance allogeneic islet graft viability
Authors: Burke Jacqueline , Zhang Xiaomin , Bobbala Sharan , Frey Molly , Fuentes Carolina , Haddad Helena , Allen Sean , Richardson Reese , Ameer Guillermo , Scott Evan
Published: November 2020

Oral rapamycin administration rapamycin is plagued by poor bioavailability and wide biodistribution. Thus, this pleotropic mTOR inhibitor has a narrow therapeutic window, numerous side effects and provides inadequate transplantation protection. Parental formulation was not possible due to rapamycin’s hydrophobicity (log P 4.3). Here, we demonstrate that subcutaneous rapamycin delivery via poly(ethylene glycol)-b-poly(propylene sulfide)(PEG-b-PPS) polymersome (PS) nanocarriers modulates cellular biodistribution of rapamycin to change its immunosuppressive mechanism for enhanced efficacy while minimizing side effects. While oral rapamycin inhibits naïve T cell proliferation directly, subcutaneously administered rapamycin-loaded polymersomes (rPS) instead modulated Ly-6Clow monocytes and tolerogenic semi-mature dendritic cells, with immunosuppression mediated by CD8+ Tregs and rare CD4+ CD8+ double-positive T cells. As PEG-b-PPS PS are uniquely non-inflammatory, background immunostimulation from the vehicle was avoided, allowing immunomodulation to be primarily attributed to rapamycin’s cellular biodistribution. Repurposing mTOR inhibition significantly improved maintenance of normoglycemia in a clinically relevant, MHC-mismatched, allogeneic, intraportal (liver) islet transplantation model. These results demonstrate the ability of engineered nanocarriers to repurpose drugs for alternate routes of administration by rationally controlling cellular biodistribution.
The Impact of the COVID-19 Pandemic on Maternal and Perinatal Health: A Scoping Review
Authors: Kotlar Bethany , Gerson Emily , Petrillo Sophia , Langer Ana , Tiemeier Henning
Published: November 2020

Introduction: Maternal health is a critical public health issue, and the Coronavirus Disease 2019 (COVID-19) pandemic has had a multifaceted impact on the health and wellbeing of pregnant individuals and mothers. Methods: A scoping review was conducted to compile evidence on direct and indirect impacts of the pandemic on maternal health and provide an overview of the most significant outcomes thus far. Working papers and news articles were considered appropriate evidence along with peer-reviewed publications in order to capture rapidly evolving updates. Narrative descriptions were written about subject areas for which the authors found the most evidence.Results: While the search yielded numerous publications, most studies were methodologically weak. Pregnant individuals were not found to experience more severe symptoms than the general population, and intrauterine, vertical, and breastmilk transmission were unlikely. Labor, delivery, and breastfeeding guidelines for COVID-19 positive patients varied. Severe increases in maternal mental health issues, such as clinically relevant anxiety and depression, were reported. Domestic violence appeared to spike. Prenatal care visits decreased, healthcare infrastructure was strained, and potentially harmful policies implemented with little evidence. Women were more vulnerable to losing their income due to the pandemic than men, and working mothers struggled with increased childcare demands. Conclusion:Pregnant women and mothers were not found to be at higher risk for COVID-19 than the general population, however they seem to face disproportionate adverse socio-economic consequences. High income and low- and middle-income countries alike faced significant struggles. Further resources should be directed towards quality epidemiological studies.
Implementation strategy fidelity evaluation for a multidisciplinary Chest Injury Protocol (ChIP)
Authors: Kourouche Sarah , Curtis Kate , Munroe Belinda , Watts Michael , Balzer Sharyn , Buckley Tom
Published: November 2020

BackgroundBlunt chest wall injuries can lead to complications, especially without early intervention. A blunt chest injury protocol (ChIP) was developed to help improve consistency of evidence-based care following admission to emergency. Implementation strategy fidelity is the extent to which the strategies of implementation are delivered in line with the intended plan. The aim of this paper was to assess fidelity to the strategies of the implementation plan developed for ChIP. MethodsA retrospective evaluation of strategies used for implementation was performed, specifically the behaviour change techniques (BCTs). BCTs were used as part of an implementation plan derived based on the Behaviour Change Wheel from results from a staff survey at two hospitals. Levels of implementation or adaptation for BCTs were scored by implementers as follows; ‘Were the behaviour change interventions implemented?’ (0 = ‘not implemented’, 1 = partially-implemented, and 2 = fully-implemented); ‘Were adaptations made to the implementation plan?’. Scored 1 (many changes from plan) to 4 (just as planned). Free text explanation to their responses was also collected with supporting evidence and documentation (such as emails, implementation checklists, audit reports, and incident reports). ResultsThere was high overall fidelity of 97.6% for BCTs partially or fully implemented. More than three quarters (32/42, 76.2%) of the BCTs were fully-implemented with an additional 9/42 (21.4%) partially implemented. BCTs that were not fully implemented were social support, feedback on behaviour, feedback on outcomes of behaviour, adding objects to the environment, and restructuring the environment. The modes of delivery with poorer implementation or increased adaptations were clinical champions and audit/feedback.ConclusionsThis study advances implementation theory and research by presenting a novel method of evaluating implementation strategy fidelity, combining previously used methods. The systematic use and application of the behaviour change wheel was used to develop an implementation plan and was associated with high implementation strategy fidelity. A fidelity checklist developed during the implementation process may help implementers assess fidelity. Trial registration Trial registered on ANZCTR. Registration number ACTRN12618001548224, date approved 17/09/2018
Enhancing Consumer Horticulture’s Millennial Outreach: Social Media, Retail, and Public Garden Perspectives
Authors: McGinnis Esther , Rihn Alicia , Bumgarner Natalie , Krishnan Sarada , Cole Jourdan , Sclar Casey , Khachatryan Hayk
Published: November 2020

The millennial generation, born between 1981 and 1996, is the largest demographic age group in the United States. This generation of plant enthusiasts has experienced financial setbacks; nevertheless, they collectively wield immense economic power. In 2018, this generation made one-quarter of all horticulture purchases. Consumer horticulture (CH) is challenged to develop targeted programming and outreach methods to connect with this influential and information-hungry generation. To examine the possibilities, the CH and Master Gardener Professional Interest Group held a workshop on 23 July 2019, in Las Vegas, NV, at the American Society for Horticultural Science (ASHS) annual conference. The workshop first actively engaged participants to build points of connection by discussing nontraditional terminology that resonates with younger audiences. Suggested terminology included plant parent, plant enthusiast, plant babies, apartment-friendly, sustainable, and urban agriculture. After the opening discussion, three presentations explored innovative content, marketing and outreach in the areas of social media, retail promotions, and public gardens. The social media presentation focused on building a two-way partnership with millennials on Instagram that emphasized shared values of sustainability, local foods, and wellness. During the second presentation, the speaker highlighted retail point-of-sale promotions that appeal to younger audiences. The final presentation described creative programming used by botanical gardens to engage younger visitors. A facilitated discussion followed the presentations to identify and evaluate techniques and content that could be incorporated into CH research, teaching, and extension to reach and interact with new millennial audiences. Based on the workshop presentations and the facilitated discussions, the ASHS CH and Master Gardener Professional Interest Group concluded that more CH professionals should engage in social media outreach tailored to the needs and preferences of younger generations. To support this valuable outreach, research of consumer behavior and retail marketing should be encouraged to identify the preferred terminology and subject matter that appeal to millennials. Finally, CH can learn from and partner with public gardens as they implement multidisciplinary programming and exhibitions.
Evaluation of anisotropy of mechanical properties of carbon steel flat products
Authors:   Irkutsk National Research Technical University, Osipok Tatiana , Zaides Semen ,   Irkutsk National Research Technical University
Published: November 2020

The purpose of the article is to establish experimentally the effect of material inhomogeneity on the characteristics of strength ( σ в, σ 0.2) and plasticity (δ) on example of a rolled steel sheet. Uniaxial tensile testing was carried out on flat samples of hot-rolled sheet made of St3 alloy cut in three directions relative to rolling: along, across and at the angle of 450. The heterogeneity of structure was established by studying the fracture surface of the destroyed samples after tensile testing. A metallographic research and micromechanical testing (measurement of microhardness) of sections parallel to the fracture surface were carried out as well. The uniaxial tensile testing of flat samples resulted in obtaining the values of the characteristics of strength ( σ в, σ 0.2) and plasticity (δ). The analysis of fracture patterns, microstructure and microhardness values of the material allowed to reveal the structural heterogeneity caused by the presence of fibrousness and a banded ferrite-pearlite structure oriented along the deformation direction. The formation reason of the latter was the presence of oriented non-metallic inclusions - elongated plastic sulfides. The study determined that the material under investigation features the anisotropy of mechanical properties and structural heterogeneity. The values of the ultimate strength ( σ в) and yield strength ( σ 0.2) decrease from the longitudinal direction to the transverse direction (relative to the rolling direction) and vice versa (from the transverse to longitudinal direction) in the first case probably due to the influence of non-metallic inclusions (plastic sulfides) and, as a result, the banded ferrite-pearlite structure; in the second case due to the influence of fiber direction. The values of the relative elongation (δ) decrease from the longitudinal direction to the direction at an angle of 450 and then increase to the transverse direction as a result of different hardening of the material during plastic deformation. This is proved by the obtained microhardness values of the investigated sections and the values of the maximum applied loads during the tensile test. The obtained values are obviously the result of the influence of fiber orientation relative to the existing maximum tensile stresses.
Controlled spindle supports as a tool for ensuring machining quality
Authors:   Komsomolsk-na-Amure State University, Sablin Pavel , Kosmynin Alexander ,   Komsomolsk-na-Amure State University, Shchetinin Vladimir ,   Komsomolsk-na-Amure State University
Published: November 2020

The purpose of the work is to provide conditions for machined workpiece surface quality control based on the use of gas-magnetic supports in machine-tool systems (on example of the 3K227A internal grinding machine). To model the trajectory of tool and workpiece mutual movement the methods of nonlinear dynamics are used. The literature data on the problem are analyzed and experimental studies are carried out. Based on the considered issues of controlling the dynamic stability of technological systems under machining by means of contactless controlled gas-magnetic supports of spindle units, a scheme for adaptive control of the machine-tool system is proposed. It allows in many respects to eliminate external mechanical effects on the technological system, internal vibrations caused by drives and moving parts, as well as to compensate temperature deformations of the spindle unit frame and body. An adaptive control system based on gas-magnetic supports of the spindle assembly and the workpiece, as well as the control systems of the position of workpiece and tool (on example of 3K227A internal grinding machine) are demonstrated in action. The gas-magnetic support control system developed at Komsomolsk-na-Amure State Technical University makes it possible to set the position of the rotor axis with the accuracy of 0.1 microns. The study results obtained lead to the conclusion that the control of two adaptive links on the gas-magnetic supports, i.e., the spindle assembly of the tool and the spindle assembly of the workpiece, allows to achieve a rotation accuracy of up to 0.2 microns. The methods of nonlinear dynamics make it possible to construct an attractor (trajectory) of the tool tip movement in the real time, which provides a possibility to affect the input parameters of the machining process and thereby to control the output parameters. In addition to this, the control system of machine-tool system dynamic stability is applicable to other processing types as well, including edge cutting machining.
Identification of measuring part elements of numerical relay protection by its response time
Authors:   National Research Tomsk Polytechnic University, Andreev Mikhail , Suvorov Aleksey ,   National Research Tomsk Polytechnic University, Rudnik Vladimir ,   National Research Tomsk Polytechnic University
Published: November 2020

The purpose of the study is to develop an identification method of a specific implementation of the elements of the measuring part (intermediate converters, analog filters) and partially computational-logical part (digital filters) of a microprocessor relay protection by the signal actuation time, which, unlike the existing approaches allows to identify and exclude the delays introduced by the executive protection elements. The method of directed graphs is used to form a mathematical model of the measuring part of the microprocessor relay protection. The solution formed as a result of differential equations is implemented using the method of analog implicit continuous integration. The time delays introduced by the input protection circuits are determined as follows: identical signals are fed to the terminal and the mathematical model of protection; signal actuation time is recorded, where the time starting point is the moment the input signal reaches the setpoint and the end point is the moment of the actuation signal occurrence. Having studied 144 different combinations of measuring part elements (intermediate converters, analog filters) and digital filters with a finite impulse response of microprocessor relay protection, the most “optimal” combination has been chosen, which features the least deviation from the response time of a real device in all studied modes as compared with other combinations. The proposed identification method of input circuit elements of microprocessor (numerical) protection is the main way to bring the model closer to a real device. It also enables to receive a table of “typical” response times of protections with the different structure of the measuring part and depending on the specific type of protection terminal choose in practice a predetermined “optimal” internal composition of protection used when setting up protection using their mathematical models.
Simulation of combined reduction of iron and non-ferrous metals (nickel, copper, lead and zinc) from oxide melts by converted methane
Authors:   Institute of Metallurgy Ural Branch of Russian Academy of Sciences, Vusikhis Alexander , Leontiev Leopold ,   Institute of Metallurgy Ural Branch of Russian Academy of Sciences, Selivanov Evgeniy ,   Institute of Metallurgy Ural Branch of Russian Academy of Sciences, Chentsov Viktor ,   Institute of Metallurgy Ural Branch of Russian Academy of Sciences
Published: November 2020

The purpose of the article is to assess the application possibility of methane of various conversion methods (СО2, Н2О, О2) for combined reduction of iron and non-ferrous metals (nickel, copper, lead and zinc) from B2O3-CaO-Fe2O3-МеО oxide melts in the temperature range of 1273-1673 K. Thermodynamic modeling is carried out using a technique, which allows to estimate the variations in phase compositions depending on the amount of the reducing agent induced. The technique differs from the known ones by sequential calculation cycles with the removal of the formed gases and the metal phase from the working fluid composition. It is found that regardless of gas composition the process goes on in several stages. In the case of the combined reduction of iron and nickel (lead or zinc), the first stage is reduction of Fe2O3 to Fe3O4 and FeO. The content of Fe2O3 decreases, while the contents of FeO and Fe3O4 increase (at the end of the stage the content of Fe3O4 reaches its maximum value). At the second stage, there is the transition of Fe3O4 → FeO when the values of the contents of Fe2O3 and Fe3O4 decrease to negligible values. The third stage features the manifestation of the metallic phase. In the case of the combined reduction of iron and copper, the process can be divided into three stages according to the variations of the content of iron oxides, and into two stages according to the variations of the content of CuO and Cu2O. The first stage of iron reduction ends at the moment when the content of magnetite reaches its maximum value, the second stage finishes when the metallic phase appears. The first stage of copper reduction includes the transition of CuO to Cu2O and achievement of the maximum value of Cu2O content. The second stage includes the reduction of copper from Cu2O. A gas with the increased content of hydrogen, which corresponds to methane steam reforming is shown to be the most effective reducing agent. The results obtained make it possible to predict the parameters of the metal reduction process during oxide systems bubbling by methane conversion products. The results will be useful for the development of technologies for selective reduction of metals.
Adjustment of cutting modes based on the data of numerical simulation of a tool-workpiece system dynamics taking into account resonances
Authors:   Irkutsk National Research Technical University, Kostin Pavel , Lukyanov Anatoly ,   Irkutsk State Transport University, Aleinikov Dmitry ,   Irkutsk National Research Technical University
Published: November 2020

The purpose of the work is to adjust the cutting modes for the manufacturing process of the Cover-Bracket part, which are set in accordance with the recommendations of the electronic catalog CoroPlus ToolGuide by the tool manufacturer Sandvik. This correction is required in order to improve the dynamic stability of machining. The problem of cutting mode adjustment is solved through the use of the methods of numerical simulation of the tool-workpiece system dynamics with regard to the resonances in the Femap engineering analysis program with Nastran. Recommendations are given for cutting modes taking into account the technical capabilities of the machine-tool and tooling, as well as the volume of the material removed with no reference for the dynamic properties of the tool and machine-tool. It is shown that at the 7th and 8th technological transitions the resonant vibrations are observed in the milling tool-workpiece system and the ratio of forces on the cutting edges of milling tools changes up to 245%, which leads to their uneven wear and decreases machining quality. It is found out that the oscillations of the processing forces can be represented as a sum of several harmonics of the rotational and tooth mesh frequencies. The results obtained show that the problem of deviation from the resonant frequencies can be solved not only by lowering the spindle speed, but also by changing the manufacturing process. Recommended change in the sequence of the technological transitions 7 and 8 allows to avoid resonance frequencies without reducing the performance level and machine at the maximum permissible cutter speed of 18,000 rpm. Under this approach, the first harmonics of the tooth mesh frequencies will be outside the resonant zone. In the future, it is planned to supplement the model with the dynamic characteristics of the machine-tool, tool and equipment.
Communication and Social Skills in Education of Health Occupation Students
Authors:   Department for Health Studies, University of Zadar, Zadar, Klarin Mira , Antičević Vesna ,   The University Department of Health Studies, University of Split, Split, Kardum Goran ,   Faculty of Humanities and Social Sciences, University of Split, Split, Proroković Ana ,   Department of Psychology, University of Zadar, Zadar, Sindik Joško ,   Institute for Anthropological Research, Zagreb
Published: November 2020

The aim was to investigate whether social skills’ training (SST) influences attitudes towards communication skills learning and to validate the Communication Skills Attitudes Scale (CSAS) among students of health studies in the Republic of Croatia. SST (10 workshops) was implemented for this purpose. Seventy 1st year students in four Croatian university health studies were randomly selected to take part in the training and 169 students were part of the control group. CSAS was administered at the beginning and end of training to both groups. The results indicated good metric characteristics in relation to CSAS and its two-factor structure (positive attitude scale and negative attitude scale). Furthermore, we did not record significant changes in attitudes towards communication skills learning in both groups. However, pursuant to average results from the subscales attitudes towards communication skills learning, we noticed that negative attitudes tend to decrease and positive tend to increase. This indicates that 10 workshops might have been insufficient in order to change attitudes. Keywords: validation, communication and social skills, training
The economic and social drivers of renewable energy development in OECD countries
Authors: Melnyk Leonid , Sommer Hanna , Kubatko Oleksandra , Rabe Marcin , Fedyna Svitlana
Published: November 2020

There are continuous research and practical interest to combine different renewable sources within one Smart Grid network. The paper aims to estimate the influence of key economic and social drivers of renewable energy and Smart Grid promotion in OECD member countries. The random effect of the generalized least squares method was used to estimate the empirical model based on the World Bank, OECD, Heritage Foundation, and World Energy Council datasets for a panel of 36 OECD counties. For the empirical estimation, the dependent variables considered are energy renewable electricity output and energy trilemma index, taken as two proxies for Smart Grid development. The results suggest that an increase in GDP p. c. in national economies by 10,000 USD leads on average to a 3.9% decrease in renewable electricity output during 2001–2015. The richer the society, the less renewable energy sources were used for power generation in a group of OECD countries. The last is also supported by the fact that gross fixed capital formation treated as a percentage value of GDP is negatively correlated with structural changes in renewable energy output. The empirical conclusion is that during the study period, OECD countries were mainly oriented to economic growth, which was achieved by consuming non-renewable energy resources, and limited attention was paid to sustainability and Millennium Development Goals. The paper provides policy recommendations for Smart Grid development and points in the future research within OECD countries. AcknowledgmentsComments from the Editor and anonymous referees have been gratefully acknowledged. Leonid Melnyk gratefully acknowledges financial support from the Ministry of Education and Science of Ukraine (0118U003578). Oleksandra Kubatko gratefully acknowledges financial support from the Ministry of Education and Science of Ukraine (0119U100766) and National Research Foundation of Ukraine (2020.01/0135).
A comparative study of phenomenological hysteretic models with application to recycled rubber-fibre reinforced bearings
Authors: Ravichandran Nagavinothini
Published: November 2020

The present study investigates the capability of different hysteresis models in representing the nonlinear behaviour of Recycled Rubber-Fibre Reinforced Bearings (RR-FRBs). A recently developed class of uniaxial phenomenological models is considered along with the Bouc-Wen Model (BWM). In particular, Bilinear Model (BM) and Exponential Model (EM), belonging to the class of above-mentioned phenomenological models, are used. The restoring force-displacement loops of RR-FRBs obtained from the different models are compared with the experimental studies retrieved from the literature. These first results show that the EM not only can accurately predict the behaviour of RR-FRBs, but it also requires a significantly lower computational time. Furthermore, to investigate the capability of the models in predicting the complete response of base-isolated structures, nonlinear time history analyses are carried out on a base-isolated rigid block with RR-FRBs. The response time histories of the rigid block and the restoring force-displacement loops obtained by using the EM are found to be in close agreement with the results obtained by adopting the BWM. In addition, the EM computational time is only 0.25 % of BWM. This clearly demonstrates the efficiency of EM in the seismic response analyses of base-isolated structures with RR-FRBs.
THE RUSSIAN CONSTITUTIONAL REFORM 2020 AND JUDICIAL POWER: INDEPENDENCE AND AUTONOMY
Authors: SALENKO Alexander V.
Published: November 2020

This article studies the content and results of the Russian constitutional reform in 2020, initiated by the President of the Russian Federation, which aimed to change the aspects of the public authorities’ functioning. The main goal of this research paper is to analyze the content of the constitutional amendments, which directly affected the Russian Judicial Power. The author systematizes and analyzes the constitutional amendments, which have reformed the Russian system of public power, initially established by the Russian Constitution in 1993.
The research focuses on the status and real role of the judiciary in the modern system of separation of powers in Russia. The Russian Constitutional Reform 2020 is studied on the basis of traditional methods of scientific research and by the use of special legal research methods (historical and legal, comparative legal and formal legal analysis).
The author concludes that the constitutional amendments of 2020 have actually entailed a real reform of the judiciary. Firstly, there was an unreasonable and unmotivated reduction in the number of judges of the Constitutional Court of Russia (from 19 to 11 people); the author believes that the actual number of judges in the future may drop to 6. Secondly, the competence of the Russian Constitutional Court has significantly changed, which entrusted this constitutional body with quasi-political powers to conduct preliminary abstract normative control of acts that have not entered into legal force, which de-facto draws the Court into the legislative process and negatively affects the possibility to challenge the constitutionality of such normative acts in the future by the submission of constitutional complaint. Thirdly, in the course of the constitutional reform of 2020, the procedure for terminating the powers of judges was revised, and now judges can be removed from their posts on the initiative of the Russian President with the formal support of the Federation Council. The author comes to the general conclusion that the Russian Constitutional Reform 2020 has weakened the judicial power, compared with other branches of power.
THE ROLE OF “THIRD PLACES” IN THE COMMUNICATIONS OF MODERN STUDENTS
Authors: AKULICH Maria M. , Mokk Elina A.
Published: November 2020

In the conditions of intensive development of the information society, the problem of achieving and maintaining a balance of off- and online communications is becoming more relevant. This is especially significant for students, who study most actively and use various information technologies.
The purpose of this study lies in exploring the role of “third places” in the communications of modern students. The authors have employed a systematic approach, the method of structural and functional analysis and a sociological survey during the study to explore the space and define the system of “third places” in a modern city. Theoretical approaches and concepts that reveal the role of “third places” in the communications of man and society are addressed. In their theoretical and empirical analysis, the authors have employed R. Oldenburg’s concept of “third places” as the main one. The authors’ definition of “third places” is explained.
The empirical research reveals “third places” with prioritization among students, and their relevance in urban environments. The frequency of visits has been determined and the needs of young people structured through the “third places” approach.
The authors have studied students’ readiness to communicate with each other and strangers, using the opportunity of new acquaintances. The results have revealed that 33% of students have their own circle of contacts in “third places” and usually spend time with friends and acquaintances, family or relatives, much less often in loneliness and classmates. In the process of informal offline communication in “third places”, students do not completely disconnect from online communication.
In general, the survey data indicate a certain success in the “third places” performing one of its main functions — providing opportunities for free informal communication, expanding the circle of acquaintances. In order to maintain and develop traditional communications in the student community, it is strategically important to develop a system of “third places” that satisfy the needs of young people.