bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Low-Level Laser Therapy as an Adjunct for Orthodontic Retention: A Systematic Review of Human and Animal Studies
Authors: Shan Zhiyi , Wong Ka Wai Frank , McGrath Colman , Gu Min , Yang Yanqi
Published: May 2020

Background: Low-level laser therapy (LLLT) has been verified effective in tooth-movement acceleration and pain alleviation during active orthodontic treatment, but its function remains inconclusive post-treatment. This systematic review aims to evaluate the effects of LLLT as an adjunct retention regimen following active orthodontic tooth movement (OTM).Methods: This review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Six databases (Cochrane Central Register of Controlled Trials, MEDLINE, Embase, Pubmed, Scopus, ProQuest) were comprehensively searched for human and animal studies published till December 2019 and screened according to our eligibility criteria. The risk of bias was assessed based on the Cochrane Handbook for Systematic Reviews of Interventions and Systematic Review Center for Laboratory Experiment Tool. Two independent reviewers performed all procedures in duplicate. Any disagreement was resolved by discussion or consultation with a third reviewer.Results: A total of 394 records were identified from the initial search. Following screening, 15 full-text articles were reviewed for eligibility (ĸ>0.90), and ultimately, eight studies (three human studies and five animal studies) were included in this review. The key outcomes considered were ‘preventing tooth relapse’ and ‘rehabilitating root resorption’. Two controlled clinical trials (CCTs) and one animal study supported the preventive effects of LLLT on the relapse of post-orthodontic tooth positions. In contrast, two animal studies reported opposing findings. Regarding the rehabilitation of root resorption, evidence supported the reparative potential of LLLT in orthodontic force-induced root resorption. Overall, there was a high risk of bias among studies, except for one randomised controlled trial. Due to the substantial heterogeneity among studies in terms of their types, participants, designs, LLLT settings and variables of interest, it was not feasible to conduct a meta-analysis; therefore, a qualitative synthesis is presented.Conclusion: The quality of evidence for LLLT contributing to the maintenance of orthodontic outcomes or a better treatment prognosis remains low. There is considerable controversy over the effects of LLLT on orthodontic relapse. However, the use of LLLT after OTM has promising reparative effects for root resorption and is generally recommended.
An emerging marker predicting the severity of COVID-19: Neutrophil-Lymphocyte Count Ratio
Authors: Zhang Minping , Xiao Enhua , Liu Jiayi , Cai Yeyu , Yu Qizhi
Published: May 2020

Background: To analyze clinical features and laboratory indicators and identify the markers of exacerbation in COVID-19.
Methods: We reviewed clinical histories of 177 patients with confirmed COVID-19. The patients were categorized into mild group (153 patients) and severe group (24 patients). The baseline demographic and laboratory indicators of all patients were collected, including the neutrophil-lymphocyte count ratio (NLCR) and C-reactive protein to albumin ratio (CAR). Receiver operating characteristic curve (ROC) analysis was performed to search for indicators predicting exacerbation in COVID-19 patients, and acquiring the area under the curves (AUCs), sensitivity, specificity and cut-off value.
Results: The age of the severe group were significantly older than those of the mild group (P <0.01). Fever was the typical symptom in all COVID-19 patients. Cough and fatigue were manifested in mild group, yet severe patients were more prominent in dyspnea. The laboratory indicators showing that the mild group mainly had an elevated C-reactive protein; the severe group had a decreased lymphocyte count and lymphocyte ratio. WBC, neutrophil count, neutrophil ratio, D-dimer, AST, ALT, LDH, BUN, CRP levels increased. Furthermore, compared to mild group, WBC, neutrophil count, neutrophil ratio (Neut%), D-dimer, total bilirubin, albumin, AST, ALT, LDH, BUN, creatine kinase, CRP, CAR, NLCR were significantly higher, the lymphocyte count, lymphocyte ratio, and APTT were significantly lower in severe group (P<0.05). The ROC indicating that NLCR, Neut%, CAR, CRP, and LDH were better at distinguishing mild and severe patients. The AUCs of NLCR was larger than others (NLCR>Neut%>CAR>CRP>LDH: 0.939>0.925>0.908>0.895>0.873), which suggested that NLCR was the optimal maker; a cut-off value for NLCR of 6.15 had 87.5% sensitivity and 97.6% specificity for predicting exacerbation in COVID-19 patients.
Conclusions: The different types of COVID-19 had significant differences in age, clinical symptoms and laboratory indicators, and severe patients might be easier to suffer from the multiple organ damage. An elevated NLCR may indicate that the disease was progressing towards exacerbation. It was essential to dynamically monitor the serum NLCR levels which contributed to evaluate the patient's condition and efficacy. NLCR could be used as a novel, highly specific and sensitive marker for predicting severity of COVID-19 patients.
Management of oncology patients receiving anti-cancer treatment in the COVID-19 pandemic
Authors: Namal Esat , Dinc Nur , Saglam Sezer , Ozturk Ali Vefa , Koculu Safiye , Yir Asiye , Cevik Esin , Sabet Soheyl , Sokmen Bedriye Koyuncu , Gurcan Nagihan Inan , Tokat Yaman , Ciftci Cavlan
Published: May 2020

Background/Aim: Severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) has deeply affected life all over the World. The World Health Organization named this disease as COVID-19. The most important factor in the transmission of the disease is asymptomatic carriers. We’ve tested all oncology patients, that receive anti-cancer therapy, for COVİD-19 to prevent asymptomatic oncology patients from spreading infection and to make the decision to postpone chemotherapy in infected patients. Then, we analyzed the clinical and radiological findings of infected patients.Materials and Methods: Oncology patients who have indications of receiving anti-cancer treatment in the hospital were tested for COVID-19, two day prior to their treatment even if they were asymptomatic by collecting nasopharyngeal and oropharyngeal swab specimens for RT-PCR for viral RNA detection. Positive patients, underwent inspiratory phase of chest computed tomography (CT) examination. Infected patients were given the recommended treatment for COVID-19. Anti-cancer treatment of all patients that had positive PCR results was delayed for 14 days.Results: PCR test was positive in 28 of 312 patients that we tested, and the positivity rate was 8.9%. Three patients (10.7%) had symptoms; 2 of whom had dyspnea and cough, and 1 had headache, and 25 patients (89.3%) had no symptoms.Conclusion: In oncology patients, who are receiving anti-cancer treatment, we have to recognize the asymptomatic COVID-19 infection. We recommend testing for COVID-19 in oncology patients receiving chemotherapy, periodically or before each anti-cancer treatment, in order to continue their treatment without any problems and to prevent the risk of transmission.
The effect of passive exposure to tobacco smoke on the immune response in children with asthma
Authors: Wawrzyniak Agata , Lipinska-Opalka Agnieszka , Kalicki Boleslaw , Kloc Malgorzata
Published: May 2020

IntroductionThere are a few publications about the impact of tobacco smoke on the children’s immune system. Material and MethodsThe study group consisted of 43 children with asthma.. The control group consisted of 37 healthy children. The exposure to tobacco smoke was assessed by the presence of the cotinine in the urine. ResultsThe group of children with asthma exposed to tobacco smoke had significantly higher levels of the IL-1 and lower levels IL-4 than children not exposed to the passive smoking. The children from the control group exposed to tobacco smoke had a significantly higher concentration of IL-4 than unexposed children. In the whole analyzed population, there was a significant correlation between the presence of cotinine and the concentration of IL-1 and CRP. ConclusionIn this study we found that the passive exposure to tobacco smoke has the immunomodulatory effects on the immune system.
Practice and perception of Bangladeshi adults toward COVID-19: a cross-sectional study
Authors: Wadood Md. Abdul , Lee Lai Lee , Huq Md. Monimul , Mamun ASMA , Mohd Suhaili , Hossain Md. Golam
Published: May 2020

Background: The coronavirus disease 2019 (COVID-19) has continued to spread across the world with increasing number of confirmed cases and death. Preventive measures have still been the only way of slowing down the transmission and prevention of the deadly disease. Practice of preventive guidelines and perception about the disease is important in this regard. We aimed to study on practice to prevent and perception toward COVID-19 among Bangladeshi adults during the rapid rise of the outbreak.Methods: For this cross-sectional study, we conducted an online survey to collect data from 320 Bangladeshi adults during the period of 10-20 April, 2020 with a self-developed questionnaire. For measuring their level of practice, a general question was asked to participants, “Are you properly following the guidelines recommended by WHO to avoid COVID-19? Four type of perceptions; (i) seriousness, (ii) susceptibility, (iii) efficacy, and (iv) carry out the measures of the disease were considered for measuring risk of perception. Frequency distribution, Chi-square (χ2) test and binary logistic regression model were utilized in this study. Results: More than 71% of participants had good practice of always following the guidelines of the World Health Organization to prevent COVID-19. Logistic regression model demonstrated that people living in urban area (p<0.01), high education (p<0.01), rich (p<0.01) and joint family (p<0.01) had the most contributions to good practice. The average risk perception among participants was 3.05±0.75 (median, 3.00) (95% CI of mean: 2.96-3.13). More than 27% participants showed high risk perceptions. It was found that males (p<0.05), high educated (p<0.05), rich (p<0.01), service holders (0.05) and younger adults (p<0.05) had higher odds of high risk perception.Conclusions: The good practice of preventive guidelines and risk perception toward COVID-19 among Bangladeshi adults were satisfactory but not of the expected level. High socioeconomic status and education were significantly correlated with appropriate practice and perception during the peak time of the COVID-19 pandemic. Government should take step to increase the level of practice to avoid and perception toward COVID-19 among Bangladeshi people during the pandemic.
Chloroquine drug and Graphene complex for treatment of COVID-19
Authors: Mohammadi Saeedeh , Esmailpour Mohammad , Mohammadi Mina
Published: May 2020

This paper is a new step in helping the treatment of coronavirus by improving the performance of chloroquine drug. For this purpose, we propose a complex of chloroquine drug with graphene nanoribbon (GNR) scheme. We compute the structural and electrical properties and absorption of chloroquine (C18H26ClN3) and GNR complex using the density functional theory (DFT) method. By creating a drug and GNR complex, the density of states of electrons increases and the energy gap decreases compared to the chloroquine. Also, using absorption calculations and spectrums such as infrared and UV-Vis spectra, we showed that GNR is a suitable structure for creating chloroquine drug complex. Our results show that the dipole moment, global softness and electrophilicity for the drug complex increases compared to the non-complex state. Our calculations can be useful for increasing performance and reducing the side effects of chloroquine, and thus can be effective in treating coronavirus.
Complex Solution of Ecological and Economic Problems of Traffic Jams
Authors: Matsenko Oleksandr M. , Kovalev Yaroslav S. , Tkachenko Olena M. , Chorna Yaroslava V.
Published: May 2020

The article explores the congestion level in traffic of motor vehicles and its negative environmental and economic consequences in case of Kiev. The amount of pollution from traffic jams in Kiev and the number of vehicles which got into them in 2009-2018 is analyzed. The loss of earnings on the side of automobile owners from their standby are calculated with corresponding quantitative expressions found and described. For the course of the research, the methods of system-structural and comparative analysis were used for analyzing the environmental and economic problems of modern automobile systems; methods of formal logical analysis were used for substantiating the innovative infrastructure of transport routes. Separately economic and statistical methods were used in the study for trends development, structure analysis, and estimation of the influence of road congestion on the environmental and economic sphere. Pearson test has indicated a close relationship between the number of cars in Kiev and the number of values from traffic jams in environmental and economic sphere. Solutions to this problem are offered in forms of automated traffic control systems, improvisation of organizational and technical methods for the distribution of traffic flows over time, namely reverse traffic, road junctions, smart traffic lights, road extension, and the transition to alternative modes of transport. In all countries of the world there are new research methods that affect pollutants from motor vehicles. It is proved that they are forced by the recipients. In addition, landscaping can improve landscape design, reduce greenhouse gas emissions, surface water runoff and noise pollution. In this regard the policy implication of the research are aimed to eliminate the negative consequences from the use of vehicles during traffic jams, and the necessary number of trees for planting in Kiev is calculated.

Key words: motor transport, congestion, traffic jam, motor vehicle, greening, compensation effect, lost profits, losses.
Forming the System of Sustainable Development Indicators for Biosocial Economy Assessment
Authors: Fedyna Svitlana M.
Published: May 2020

The paper compares frequently used methods for sustainable development assessing. We studied the systems of sustainable development indicators for assessing its individual areas (in particular, economic, environmental and social), and also analyzed aggregate indices designed for a comprehensive assessment of development both at the macro level and at the level of specific individual territorial units. For each methodology, the structures of index systems were presented with their breakdown into spheres and blocks / categories, and the main disadvantages of each methodology were determined. Among the methodologies considered are the following: the methodology proposed by the Global Biopact, indicator systems from the OECD Green Growth Strategy and World Bank indicators. The work carried out a structural analysis and explored the content of aggregated indices: Social Progress Index, Environmental Efficiency Index, Global Climate Change Adaptation Index and Human Development Index. The listed systems of indicators and indices are used at the global level, their use for Ukraine needs to be adapted. The adaptation of such techniques to the Ukrainian realities was shown on the example of a system of indicators based on the goals of sustainable development. Each goal has a number of tasks, the implementation of which is necessary to achieve it. For each task, several indicators are proposed for assessing the level of their implementation, an analysis of these indicators showed that for Ukraine, metadata has not been defined for indicators for most of the goals. In the above methods, indicators for assessing the bioeconomic direction (with the exception of biodiversity) are almost not presented, therefore, the development of a model for assessing the biosocial economy requires the inclusion of indicators characterizing bioresources, biotechnologies, and bioenergy.

Key words: index, indicator, sustainable development, biosocial economy, bioeconomics, biodiversity, sustainable development goals.
Septic cardiopathy: disputable issues and prospects
Authors: Kozlov I. A. , Tyurin I. N.
Published: May 2020

The objective: to present current information about definitions, etiopathogenesis, clinical, laboratory and hemodynamic manifestations of septic cardiopathy, based on published data and the results of our own research.

Results: septic cardiopathy is the most important pathogenetic component of sepsis, and cardiac dysfunction makes a significant contribution to its outcomes. It is found out that after staying in the intensive care unit for 3-4 days, the level of the inactive part of the precursor of the B-type natriuretic peptide (NT-proBNP) > 3,450 pg/ml indicates of the risk of death: area under ROC curve (AUC) 0.708 (p = 0.0041), sensitivity 63.6%, and specificity 66.7%. At the same time, NT-proBNP > 5,250 pg/ml is associated with the use of inotropic drugs: AUC 0.769 (p = 0.0007), sensitivity 76.9%, specificity 79.0%. The article describes the detection of septic cardiopathy using transpulmonary thermodilution and calculation of such indices as afterload-related cardiac performance and cardiac function index. Data on the age-related parameters of central hemodynamics and risk of pathological decrease in certain blood circulation indices characteristic of older patients are presented. The article discusses the feasibility of treating septic cardiopathy as a variant of acute heart failure, which can be manifested not only by a decreased systolic function (low left ventricular ejection fraction) but also by increased end-diastolic pressure in the ventricles (diastolic dysfunction) with a normal left ventricular ejection fraction.
Principles of anesthetic management of surgeries in diabetes patients
Authors: Neymark M. I.
Published: May 2020

The objective: to describe the modern aspects of perioperative management of diabetes patients.

Results:glycemic level correction makes the main task of preoperative preparation. The article presents modern approaches to solving this problem in emergency and planned surgery, target parameters of blood glucose concentration, criteria of patients' readiness for surgery. The principles of choosing the anesthesia method, features of regional anesthesia, and infusion therapy are discussed.
Management of anemia in patients in the pre- and postoperative period and critically ill patients
Authors: Khalikova E. Yu. , Silaev B. V.
Published: May 2020

The objective: to provide information and discuss the most justified and rational ways of anemia management in the perioperative period and in critically ill patients.

Results: anemia as a syndrome associated with the perioperative period and critical conditions occurs in patients of the intensive care unit in 30–70% of cases. Currently, there is a clear trend towards restrictive blood transfusion tactics, the individualization of the anemic status of the patient, as well as the personalization of the treatment. Alternative approaches to blood transfusion are encouraged to improve the oxygen transport function of the blood, including the use of iron supplements in adult patients with hypoferric anemia and treatment with drugs that stimulate erythropoiesis.
New genome editing technologies in the treatment of X-linked adrenoleukodystrophy
Authors: Voinova V. Yu. , Shkolnikova M. А. , Nikolaeva E. A.
Published: May 2020

X-linked adrenoleukodystrophy is a severe progressive neurological disease that is predominantly found in male patients and caused by mutations in the X-linked ABCD1 gene encoding peroxisome transport protein. The disease is clinically characterized by two main phenotypes: the most severe infant cerebral form and adrenomyeloneuropathy. The disease is treated by allogeneic transplantation of hematopoietic cells from a healthy donor to stop progression, and gene therapy with a self-activating lentiviral vector, the carrier of the functional gene ABCD1. Each method has its own limitations. The authors present and theoretically substantiate an alternative approach to the treatment of adrenoleukodystrophy; they propose to modify the autologous CD34+ cells from the patient using genomic editing, in order to replace the mutant DNA sequence of ABCD1 gene with a wild-type sequence, while replacing the mutant protein in the edited cells. The edited autologous CD34+ cells can be introduced by their transplantation into the bone marrow or by a series of repeated intravenous infusions. This method will allow avoiding both the search for a donor and the graft-versus-host reaction
Alagille syndrome in children
Authors: Volynets G. V. , Nikitin A. V. , Skvortsova T. A.
Published: May 2020

Alagill syndrome is a rare genetic disease with an autosomal dominant type of inheritance, which is characterized by chronic intrahepatic cholestasis due to an abnormality of the biliary tree in combination with multiple malformations. It presents certain difficulties in diagnosing little children, when it is necessary to accurately determine the cause of cholestasis and the tactics of further treatment.

Objective. To analyze clinical manifestations and laboratory parameters in children with Alagill syndrome.

Characteristics of children and research methods. The authors carried out a retrospective continuous analysis of the clinical and diagnostic manifestations of Alagill syndrome in 21 children (10 boys and 11 girls) aged from 1 month to 14 years 5 months (average age 5 years ± 1 year). They studied their history of life and illness, assessed the course of pregnancy, first clinical manifestations of the disease, the results of clinical and diagnostic tests at the beginning of the disease and the analyses conducted at the place of residence and during the first hospitalization. All children underwent ultrasound examination of the abdomen and biochemical blood test.

Results. When analyzing clinical and diagnostic criteria of children with Alagille syndrome we found the following diagnostically important criteria: the threat of termination of pregnancy in mothers, fetal hypotrophy, prolonged neonatal period of jaundice, which may further persist and be accompanied by hepato / hepatosplenomegaly (more common for children above 3 months old), hypo-/ acholic stool, which occasionally occur in 3-month-old children, coagulopathy, more characteristic of children under 3 months old, as well as changes in biochemical blood parameters: the cytolytic activity – 2–5 times above the limits, hyperbilirubinemia (with a predominance of direct bilirubin fraction) – 3–7 times above the limits, gamma glutamyl – 2–7 times above the limits.

Conclusion. Alagill syndrome should be diagnosed as early as possible to determine further treatment tactics. A detailed history, analysis of clinical and diagnostic manifestations of the disease, especially changes in biochemical blood tests are important for the diagnostics of this disease.
The role of endothelial cell precursors in the blood of pregnant women and newborn children
Authors: Popova I. G. , Sitnikova O. G. , Nazarov S. B. , Kuzmenko G. N. , Kharlamova N. V.
Published: May 2020

The authors analyzed the literature data on the importance of the content and determination of the endothelial progenitor cells in the blood of pregnant women and newborns. The endothelial progenitor cells reflect the condition of the endothelium, its damage or regenerative capacity and they play an important role in the regulation of vascularization. The number of endothelial progenitor cells and molecular markers regulating their functions in the blood of a pregnant woman and a newborn may be of diagnostic importance for the prediction and diagnosis of pregnancy complications in the mother and perinatal pathology in newborns, which is relevant for the search for methods of targeted correction of these disorders.
Rotavirus infection and immunity: discussion issues of clinical and immunological studies
Authors: Gorbunov S. G. , Mazankova L. N. , Os’kin A. N.
Published: May 2020

The article reflects the literature data on the immune response mechanisms to rotavirus infection. The authors note that innate immunity factors play the leading role in protecting the organism from rotavirus. They demonstrate that both cellular and humoral components of the immune system are important in the pathogenesis of rotavirus infection. The protective effect is based on the activation of interferon and other cytokines, as well as TLR – innate immune receptor for double-stranded rotavirus RNA. The authors also describe the age-related aspects of the immune response, which cause a higher susceptibility to rotavirus in the neonatal period and its reduction with age.
The Y chromosome disomy syndrome (47, XYY) in children with mental retardation, deviations of sex development and different genome anomalies: molecular cytogenetic studies
Authors: Vorsanova S. G. , Solovyev I. V. , Kurinnaya O. S. , Kravets V. S. , Kolotii A. D. , Demidova I. A. , Sharonin V. O. , Yurov Yu. B. , Yurov I. Yu.
Published: May 2020

The article present the results of retrospectively analyzed children (4424 boys) with mental and psychomotor retardation, congenital malformations and/or developmental micro anomalies. 23 children had various forms of Y chromosome dysomy syndrome. The frequency of this syndrome in the studied cohort was 0.52%; and in this connection the authors discussed the role of Y-chromosome in the origin of mental retardation. Besides, the chromosome instability in sex and somatic cells is supposed to be a common mechanism of different chromosomal anomalies. The authors discussed the possibility of cytogenetic and molecular cytogenetic diagnosis, and also clinical polymorphism of the syndrome. The authors established the necessity of molecular cytogenetic technologies in the diagnosis of different forms of the syndrome, including mosaic forms and isodicentric chromosomes-connected forms. The severity of clinical symptoms doesn’t depend on presence of regular or mosaic forms of the syndrome. The study assumes a possible connection of clinical polymorphism with mosaisism, associated with the presence of abnormal cells (cell lines) in different tissues, together with the role of Y chromosome in the origin of mental retardation in children with Y- chromosome disomy syndrome and other chromosomal anomalies. The authors underline the necessity of molecular cytogenetic diagnosis of different forms of the syndrome for correct medical and genetic consultation.
Dynamics of the incidence in the 15–17-year-old men in the Russian Federation
Authors: Banteva M. N. , Manoshkina Е. M. , Matveev E. N.
Published: May 2020

In recent decades, the Russian Federation has seen an increase in the incidence of the population, including children and adolescents.

Objective: to identify trends in the incidence and “to chronize” the pathology of young men in the Russian Federation. Using the method of descriptive statistics, the authors analyzed the overall and for the first time recorded incidence in 15–17-year-old men in 2000–2017. The authors noted a 35,8% increase in the overall incidence rate and a 35,4% increase in the for the first time recorded incidence rate. The maximum increase in the overall incidence is observed in the following classes: neoplasms (2,6 times), blood and bloodforming organs diseases (2 times), congenital anomalies (malformations; 1,8 times), circulatory system diseases (1,7 times), the musculoskeletal system and connective tissue diseases (1,6 times), endocrine and metabolic disorders (1,5 times). Based on theoverall and for the first time registered incidence the authors calculated the “chronicity” of diseases. With a general growth rate of this indicator of 0,3% there is a significant growth of this indicator for certain diseases: mental disorders and behavioral disorders (2,1 times), congenital anomalies (malformations; 1,9 times), endocrine system diseases, metabolic disorders (1,5 times).
Surgical treatment of epilepsy in a teenager with tuberous sclerosis
Authors: Polyanskaya M. V. , Vasilyev I. G. , Chadaev V. A. , Demushkina A. A , Khondkaryan G. Sh. , Zavadenko N. N. , Alikhanov A. A.
Published: May 2020

Tuberous sclerosis is one of the genetically determined neurodermal syndromes, characterized by focal epilepsy, which is resistant to drug therapy in most cases. Tuberous sclerosis has not been surgically treated for a long time due to the multifocal nature of brain damage. However, using new instrumental methods the surgeon can isolate tuber – “drivers”, responsible for epileptic induction, which, therefore, can be a target for surgical removal. The article presents a clinical case of the treatment of pharmacoresistant epilepsy in a 17-year-old girl with tuberous sclerosis and normal neuropsychiatric and cognitive status; the surgeon managed to achieve a complete regression of seizures after the surgical removal of one of the tubers. Using a multimodal complex of examinations, including high-resolution magnetic resonance imaging and invasive electroencephalographic monitoring, the surgeon managed to identify the “inductor” tuber associated with the epileptic initiation zone among multiple cortical tubers. This section of the cerebral cortex was subjected to surgical resection. For the entire postoperative period (16 months) there were no seizures and antiepileptic drugs were canceled; cognitive processes, memory were improved. Thus, active surgical tactics may be effective in more than 50% of patients with tuberous sclerosis and pharmacoresistant epilepsy. This case confirms the need for a multidisciplinary examination prior to the surgery in patients with tuberous sclerosis.
Medical and legal problems of nursing children with extremely low body weight
Authors: Komkova G. N. , Basova A. V.
Published: May 2020

The authors analyzed the Russian legislation, scientific literature and law enforcement practice on the nursing of newborns with extremely low body weight. They used the normative legal acts, scientific articles and court decisions on this topic. There were identified the problems of legal regulation of medical care to newborns with extremely low body weight, as well as the facts of infringement of the rights of doctors in cases of mortality of such children. The authors concluded that the legal regulation of medical care for children with extremely low body weight requires further improvement, careful analysis by medical specialists, since from a legal point of view there is no balance between the interests of children born with extremely low body weight, their parents and doctors.
The impact of labor unions on corporate tax avoidance: evidence from Korea
Authors: Shin Ilhang , Park Sorah
Published: May 2020

This study examines the effect of labor unions on corporate tax avoidance activities. Labor union is an important stakeholder in terms of corporate governance; thus, managers may engage in certain accounting choices that reflect union members’ position to improve the relation with labor union. This paper empirically investigates whether managers engage in tax avoidance activities to secure financial resources for workers’ pay when the negotiation power of labor unions is higher. The empirical analysis is based on a sample of firms listed in the Korean stock market from 2001 to 2008. The authors find that companies, where labor unions are organized, have a significantly higher level of tax avoidance activities. Also, the authors attempt to examine the effect of labor unions’ bargaining power on tax avoidance. While the union membership ratio is not significantly related to tax avoidance, labor unions that belong to upper-level labor organizations significantly affect the increasing tax avoidance activity, on average. Moreover, companies that join an aggressive labor organization (‘Minju’ Federation) show a significantly higher level of tax avoidance activity, compared to those joining a moderate labor organization (‘Hanguk’ Federation). Furthermore, the authors show that such an effect of labor unions on tax avoidance is significant for companies, which are not affiliated with large business groups (‘chaebols’). This result suggests that chaebol group management is not under pressure to negotiate with union members due to higher reputation costs. The findings of this paper offer academic and practical implications that capital market participants need to understand labor unions’ effect on management’s accounting choices.
Numerical simulation analysis of hybrid impact cutting and its comparison with torsional impact cutting
Authors: Zeng Yijin , Liu Weiji , Ding Shidong , Zhu Xiaohua
Published: May 2020

Hybrid impact drilling is a new drilling method proposed in recent years, the PDC (polycrystalline diamond compact) bit impacts the rock in torsional and axial directions during its rotation. From the perspective of field application, hybrid impact drilling can increase the rate of penetration (ROP), especially in hard heterogeneous formations. However, its rock breaking mechanism and difference from torsional impact drilling are not clear, this leads to aimless in choosing these two drilling methods. In this paper, the quasi-3D numerical simulation model of hybrid impact cutting is carried out to investigate the rock breaking mechanism, including the chip formation, mechanical specific energy (MSE) etc. moreover, its comparison with torsional impact cutting is also conducted for evaluating the applicability of these two methods for the same formation. The results show that, the rock breaking efficiency of hybrid impact cutting is higher than torsional impact cutting for shallow depth of cut (DOC), on the contrary, the rock breaking efficiency of hybrid impact cutting is more lower for the medium DOC; but for the deep DOC, both of these two cutting methods cannot improve the rock breaking efficiency. The axial impact amplitude and frequency have large influence on rock breaking efficiency, the optimal axial impact amplitude and frequency exist for specific formation. Both of these drilling methods are not applicable to soft formations. This study leads to an enhanced understanding of rock breaking mechanisms in hybrid impact drilling, and contributes to the improvement in the design of impact tools and determination of the related parameters.
Effects of variable parameters on the behaviour of the single flexibly-mounted rod in a closely-packed array
Authors: Upnere Sabine , Jekabsons Normunds , Dementjevs Sergejs , Wohlmuther Michael
Published: May 2020

Experiments of flow-induced vibrations using a closely-packed triangular rods array with a pitch-to-diameter ratio of 1.1 in water cross-flow were carried out to analyse the detected effects of system parameters in the frequency domain and vibration amplitudes. Single flexibly mounted rod with two degrees of freedom at each end of it was located in the second or the fourth row in the bundle with 21 row. Influence of increasing/decreasing flow, the test rod mass and support stiffness changes were analysed. Reynolds number based on the freestream velocity and a rod diameter was up to 1.64·104. Accelerometers and laser sensors were used to measure the time-varying response of the test rod. FFT approach was adopted to reconstruct the displacements from accelerometer measurements. Experimental results show that the behaviour of the flexibly-mounted rod is dependent on the flow time-history. Dominant flow-dependent and flow-independent frequencies were observed in the frequency domain. Changes in the frequency spectrum introduced by the test rod mass and support stiffness were identified. Oscillation regime of the test rod when the state equilibrium position becomes unstable with the limited oscillations was detected. Metamodeling approach was applied to develop mathematical approximation using three parameters: flow rate, stiffness coefficient and frequency ratio. Good accordance has been found between the inverse model and laboratory experiments.
Electrolytic capacitor life time calculation under varying operating conditions
Authors: Dzhunusbekov Erlan J. , Orazbayev Sagi A.
Published: May 2020

A fair evaluation of an electrolytic capacitor time to failure is important for the design and development of electronic devices. In practice, it is required to consider variable operating conditions, for example, weather temperature fluctuations or load variations. Based on the principle of Miner’s fatigue accumulation and reasonable approximations, the general formulas are derived that take into account weather temperature changes. The outdoor air temperature was modeled by the sum of components like averaged seasonal changes, averaged daily temperature changes and random temperature fluctuations. An Easy-to-use analytical formulas for the electrolytic capacitor life time estimation were obtained, in which the contribution of each individual temperature phenomenon can be evaluated. The impact of these components on the non-linear estimation formula by the Miner's principle has been clarified for some example climatic regions. Also, the capacitor life time estimation formula under particularly scheduled variable load was derived for example. The resulting formulas are useful for engineering calculations of the reliability of electronic devices exposed to weather temperature changes.
Influence of characteristic parameters of signal on fault feature extraction of singular value method
Authors: Zhou Xintao , Cui Yahui , Ma Na , Liu Xiayi , Li Longlong , Wang Lihua
Published: May 2020

The detection of mechanical fault signals by singular value decomposition is a commonly used method in fault diagnosis. The delay time of the fault signal time series and the rationality of the value of the phase space embedding dimension, as well as the fluctuation of the characteristic parameters of the fault signal, will cause the singular value decomposition method to have a greater impact on the accuracy of fault feature identification and diagnosis. In this article, the simulation model of the similarity signal is established by the combination of the autocorrelation function method and the Cao’s algorithm. Then, the delay time of the signal sequence and the optimal value of the embedded dimension are obtained through simulation. Next, using this method to study the fluctuation of the characteristic parameters such as the frequency, amplitude and initial phase of the signal, the relationship between the characteristic parameters of the signal and the singular value of the signal is obtained. Finally, through the experimental study of the pitting corrosion of the gear tooth surface, the vibration of the fault feature is obtained. The research shows that the combination of autocorrelation function method and Cao's algorithm can calculate the optimal characteristic parameters for the singular value decomposition method and improve the ability of the method to identify fault features.
Rolling element bearing weak fault diagnosis based on spatial correlation and ALIFD
Authors: Zhao Lei , Zhang Yongxiang , Zhu Danchen
Published: May 2020

Vibration signals of rolling element bearings during operation are always very complex, random strongly and broadband. Adaptive Local Iterative Filtering Decomposition (ALIFD) can overcome the smoothness and adaptive flaws of Iterative Filtering Decomposition (IFD), but it is so susceptible to random noise that it’s less effective. Here, spatial correlation was proposed. Firstly, the signal was denoised by spatial correlation and decomposed into several modes by ALIFD. Finally, the envelope demodulation was analyzed to extract fault feature. The simulating signal analysis and bearing fault simulator show that this method can be available for separating different frequencies of bearing fault vibration signals.
The computational method of substructure’s frequency response function in transfer path analysis
Authors: Chen Ke , Li Ning , Jiang Shaowei
Published: May 2020

The multi-degree-of-freedom coupled vibration system with “engine-mount-body” as the transfer path was divided into active substructure (engine), passive substructure (body) and linking components (mounts) between active and passive substructure. According to the dynamic equation of multi-degree-of-freedom coupling vibration system, the computational method of the substructure’s Frequency Response Function (FRF) was proposed. For the coupled vibration system of the real vehicle’s transfer path, the computational method of the substructure’s FRF was used to obtain the FRF of substructure and dynamic mount stiffness based on the FRF of system obtained by the hammering test. Combining the dynamic mount stiffness with the vibration acceleration of the active and passive sides of the mount, the operating load was identified based on the mount-stiffness method of the transfer path analysis. Combining the operating load with the FRF of substructure to analyze the contribution of the transfer path, the contribution of each path to the target location (the Z-direction of the front floor of the cab) was presented. The correctness of the computational method of the substructure’s FRF was presented by calculating the vibration isolation ratio of the mount, which provided theoretical support for the research of dynamic characteristics of the substructure and linking components.
Multiple root resonance of tandem mill
Authors: Xiao Biao , Yan Xiaoqiang
Published: May 2020

The multiple-root resonance theory is introduced. The multiple-root resonance region is defined, and it includes the sub-multiple-root resonance region and complete-multiple-root resonance region. It is proved that the vibration mode shapes are identical if the natural frequencies are similar in size. The dynamic analysis of the 3-DOF model is investigated, and the results show that the variations of the mass ratio and stiffness ratio induce the natural frequencies approaching and forming a multiple-root resonance. The dynamic analysis of the tandem mill is made to study the multiple-root vibration, and the results show that with the increase in mass ratio, the 6th and 7th-order natural frequencies continue approaching one another and converge at the 5th-order natural frequency. The finite element analysis of the rolling mill shows that there are two similar natural frequencies in the rolling mill, and the vibration modes are not identical but have large vertical-component vibrations. The field test shows that the multiple-root resonance occurs in the tandem mill; after the foundation reconstruction, the multiple-root resonance is replaced by resonance with one dominant frequency, and the vibration is reduced.
Two-span bridge under moving load – numerical and experimental approach
Authors: Valašková Veronika , Kuchárová Daniela , Melcer Jozef
Published: May 2020

From the point of view of bridge structures, the moving load is one of the most important components of the load. The analysis of the influence of moving load on bridges is carried out numerically or experimentally and can be traced in the literature since the year 1849. The first impulse was the collapse of the Chester Rail Bridge in England in the year 1847. The present paper analyses the effect of the moving load on a two-span bridge, both numerical and experimental way. The planar model of the vehicle and the bridge is adopted. The bridge is modeled as Bernoulli-Euler beam. The heavy vehicle is modeled as a discrete computational model with 8 degrees of freedom. Two approaches are used in numerical modeling. For the first time, the task is solved by the finite element method in the environment of the program system ADINA. The Newmark's method is used for the solution of equations of motion. The classic approach is used for the second time. A discrete computational model of a bridge with two degrees of freedom is used. Equations of motion are solved numerically in the environment of program system MATLAB by the Runge-Kutta 4th order method. The influence of vehicle speed on vertical deflections in the middle of individual bridge fields is analyzed in the speed range from 0 to 130 km/h with a step of 5 km/h. The detailed comparison of both numerical approaches is made at a vehicle speed of 70 km/h. The deflections of the bridge and the deflection of the vehicle are compared with each other. The correctness of the assumptions used in the numerical solutions was verified by measurement on a model beam in the laboratory. The results of the experimental tests were compared with the results of the numerical solution.
Artificial neural network system analysis and Kriging methodology for estimation of non-revenue water ratio
Authors: Şişman Eyüp , Kizilöz Burak
Published: May 2020

The non-revenue water (NRW) ratio parameter is significantly important for performance evaluation of water distribution systems. In order to evaluate the NRW ratio, the variables influencing this parameter should be determined. Therefore, the first aim of the paper is to define the variables which are influential on the estimation of the NRW ratio and then analyze these variables by using artificial neural networks (ANNs) methodology by means of 50 models with one, two, three, and four-variable input. Secondly, in this study, the NRW ratios have been predicted for the first time by using the Kriging methodology through only two variables. By using the data measured in 12 district meter areas (DMA) in Kocaeli, 60 models in total have been established for NRW ratio prediction through the ANN and Kriging methodologies. The ANN models are closed-box models and therefore the interpretation of the ANN model results requires higher expert opinion. As a consequence, the results show that Kriging model graphs produce much more useful information than ANN models in terms of application and interpretation.
A sand composite with surface gel coating containing alkylamine toward the removal and immobilization of complex metal ions from electroplating wastewater
Authors: Chen Feng , Tao Wenhong , Ng Dickon H. L. , Zhang Luteng , Liu Shiquan
Published: May 2020

SiO2 gel was formed on the grain surface of silica sand by hydrolysis and condensation of tetraethyl orthosilicate in water with the addition of 1-butylamine. The resultant product was a composite consisting of sand grains with mesoporous silica coating containing alkylamine inside. This composite exhibited basicity in the wastewater from copper electroplating due to its release of amine. As a result, the strongly acidic wastewater was neutralized and the co-precipitation of complex metal ions occurred. It was shown that up to 12 major metal ions in the wastewater could be simultaneously removed under static condition at room temperature by using the sand composite. The Fe and Cu in the wastewater could be removed completely, while the concentrations of Al, Cd, Ti, V, and Zn in the wastewater were reduced by two to three orders of magnitude. After the removal of multiple metal ions from the electroplating wastewater, the used sand was further applied as a raw material for making a silicate glass. The glass was chemically stable and thus the heavy metal ions from the wastewater were immobilized.