bluuebunny/crossref_metadata_2025 huggingface dataset:
The enterprise capital structure management model
Authors: Bagatska K , Batrakova T , Silakova H , Klymash N , Vialets O
Published: August 2021

Purpose. To create management algorithms for the enterprises capital structure and mathematical formalization of optimization of this structure. To investigate the dynamics of changes in the share of profitable enterprises to assess, analyze and forecast changes in the capital structure of homogeneous groups of enterprises. Methodology. Both empirical and theoretical methods of cognition are used to conduct the research. Methods of scientific observation and comparison are used to form the topic of scientific work, goals and objectives of the study. Methods of analysis and synthesis, induction and deduction, abstraction are used to determine the essential features of capital structure management. Methods of system structuring and modeling are used to create a mathematical model. The analogy method is used to find the weight factor of the objective function. The axiomatic method and the method of convergence from the abstract to the concrete were used for the practical application of the mathematical model, in particular, to analyze the dynamic index of related companies, stratified by size, industry, and so on. Findings. The dynamics of the preconditions for changing the capital structure is studied, the regularities of this change for groups of homogeneous enterprises are revealed. The uneven influence of the crisis on the approaches to the formation of capital structure in groups of homogeneous enterprises is revealed, and the reasons for this are investigated. The similarity of tendencies of formation of capital structure in groups of inhomogeneous enterprises is pointed out. A correlation was found between the decrease in the share of equity and a significant prevalence of external borrowing with an increase in net loss. Moreover, it is established that enterprises, whose total amount of equity and current liabilities is stable and comparable in size with external borrowing, show a decrease in losses. Originality. Algorithms for capital structure management and a mathematical model for optimizing capital structure are proposed. A method of comparative analysis of changes in capital structure for homogeneous groups of enterprises has been introduced, which provides an opportunity to assess the impact of external risks and crisis factors in the past and predict the necessary changes in capital structure during both the new crisis and after the crisis. Practical value. The developed algorithms and mathematical model can be used in research and management practice to manage capital structure. Useful for different categories of professionals are approaches to the analysis of capital structure, the results of the analysis of the causes of change, the study on trends and their consequences for homogeneous enterprises.
Comparative analysis of public management models
Authors: Ingram K , Nitsenko V
Published: August 2021

Purpose. Comparative assessment on the relevance of paradigms that lead to the development of new public administration models. Methodology. A comparative analysis was conducted in the research in order to provide a comprehensive understanding, from occupational and academic viewpoints, on the existing public administration models, which are traditional public administration, new public management and new public governance, spatial features which contribute to new paradigmatic exemplars and viewpoints. Findings. There are some important aspects in the understanding of paradigms in public administration models. To that extent the overall framework of public administration models are paradigms that constantly shift when a crisis occurs. This demonstrates that the new developed public administration models will not always fit in one paradigm, and can exist in a hybrid state where various characteristics of other paradigms overlap the other. Identifying these characteristics aids in determining the applicability of current models to regulating governance and management of public sector entities and functions as well as its designation. Originality. Previous research indicates that numerous attempts in understanding and developing a systematic approach to the order of public administration have been made. To date, the development of public administration as a discipline is perceived as a succession of overlapping paradigms. Notwithstanding this, public administration still remains the single most important aspect of bureaucracies in the world. With the government deciding on all aspects of civil society in capitalist, socialist and democratic states the objectives of public administration are termed to be in a continuous state of paradigm shift. Paradigms provide solutions and determine whether areas of a particular phenomenon are problematic and many public administrative practitioners have often adopted the paradigmatic assumptions that politicians, officials, and citizens are motivated by self-interest, and will perceive the development in public administration in this light. Practical value. The work provides an interpretation on the functions and prospects of public administration as a discipline that lead to the development and transition from traditional public administration (TPA) to new public management (NPM), then new public governance (NPG) and further on to other post-new public management models.
Methodological approach to the credit worthiness estimation of counterparties at mining enterprises
Authors: Kylnytska Ye.V , Gluhova S.V , Kitchenko O.M
Published: August 2021

Purpose. Development of a comprehensive methodological approach to the credit worthiness estimation of counterparties in the mining industry as a part of a conservative credit policy. Methodology. The tasks set in the article have been solved by using modern general scientific and special methods: abstract and logical method for the implementation of theoretical generalizations, the conclusions and recommendations formation; the hierarchy analysis method to justify the priority of structural parameters for credit worthiness estimation of counterparties of mining enterprises. Moreover, the authors own previous research results regarding receivables management are used. Findings. The structural parameter priority of the credit worthiness estimation of counterparties at mining enterprises within the conservative credit policy has been propose`d, which is substantiated by the hierarchy analysis method. Synthesizing the formed hierarchical model and theoretical achievements on the issues of receivables management, a structural and logical sequence of the credit worthiness estimation of counterparties of mining enterprises has been developed. Originality. A comprehensive methodological approach to the credit worthiness estimation of counterparties in the mining industry within a conservative credit policy has been developed. Compared to the existing ones, it is a clear algorithm of estimation stages based on a hierarchical model of structural parameters of credit worthiness estimation. The advantages of the authors development are: system flexibility at the stage of formation of criterion base and structural components; clear formalization of results; detailed structuring of evaluation parameters; the possibility of forming a clear unambiguous conclusion about the credit worthiness estimation of counterparties of mining enterprises; compliance of the methodological tools of the estimation system to current trends in the mining industry. Practical value. A comprehensive methodological approach to the credit worthiness estimation of counterparties in the mining industry is used to achieve the effective planning, regulation, control, rational organization of relations in the field of cash flow.
Student survey as a tool for quality assurance in higher education: the case of Ukrainian university
Authors: Liuta O , Lieonov S , Artyukhov A , Sushko-Bezdenezhnykh M , Dluhopolskyi O
Published: August 2021

Purpose. To determine the level of students interest in internal quality assurance, particularly in passing the survey and changing the teaching quality level and improving teachers pedagogical skills. Methodology. For the data collection, a questionnaire was used which included closed-end questions on the quality of teaching and open questions in terms of comments and recommendations of higher education students on the quality of teaching and several questions concerning the share of classes in the discipline attended by the students, ECTS scores, received by students from the relevant disciplines and the average score for the entire period of study. Findings. Sumy State University (SSU) introduced an online survey of students as the main consumers of educational services regarding the quality of teaching disciplines. Over the last 3 academic years, there has been an increase in the number of teachers whose activities are evaluated by students. There has been an increase in the number of teachers who, according to students, show excellence in teaching, which is a positive trend. If in the 20172018 academic year the number of such teachers in SSU was 57people, then in the 20192020 academic year, it increased by 35% to 77 people. Quality level Above average was determined for 120 teachers in the 20172018 academic year, and in the 20192020 academic year, their number increased by 30% and amounted to 156 people. It is noteworthy that in the 20192020 academic year compared to 20172018, there is a reduction in the number of teachers from 71 to 66 people (7%), who demonstrated the level of teaching Low. Originality. Survey of students on the quality of teaching educational components, on the one hand, allows monitoring students satisfaction with methods used by the teacher in training and communicating with students, and on the other hand, it is a method to control the institutions authority over the educational service quality and the HEIs mission implementation. It also indicates an increase in students interest in participating in higher educations internal quality assurance. An important factor influencing the positive dynamics of the teaching quality level is that each semester teachers receive a detailed analysis of students answers with a visual display for each questionnaire, as well as their comments and suggestions for teaching the relevant discipline through the information service Personal teachers office based on the results of the survey. Practical value. According to the analysis results of the received information, managerial decisions can be developed and implemented to improve the content and practice of educational components implementation, improving the professional skills of research and teaching staff, advancement of best pedagogical practices.
Measurement of the difference in the geomagnetic induction between the magnetometer pillars of the geomagnetic observatory of the Ukrainian Antarctic Akademik Vernadsky station
Authors:   State Institution National Antarctic Scientific Center, Ministry of Education and Science of Ukraine, Kyiv, 01601, Ukraine, Leonov M. , Otruba Yu. ,   State Institution National Antarctic Scientific Center, Ministry of Education and Science of Ukraine, Kyiv, 01601, Ukraine
Published: August 2021

The article describes the features of measurements of spatial inhomogeneities of the geomagnetic field between the pillars of magnetometers in the measuring pavilion, which were carried out at the geomagnetic observatory of the Ukrainian Antarctic Akademik Vernadsky station in 2015. Some preliminary results of these measurements are also given. The concept of the timescaled value of the geomagnetic field induction is introduced, which is convenient for compensating for time changes of the real geomagnetic induction and bringing it to one reference level of induction. The differences in geomagnetic induction between pillars are obtained as the differences in time-scaled values of the geomagnetic induction on the pillars. The technique allows comparing long-term series of measurements of field inhomogeneities at important points in space. The main objectives are to increase the accuracy of measurements of local inhomogeneities of the geomagnetic field in the measuring pavilion of the geomagnetic observatory of the Ukrainian Antarctic Akademik Vernadsky station and to determine the differences in the geomagnetic induction between the pillars on which the magnetometer sensors are installed. Obtaining numerical values of the differences in the geomagnetic induction between the pillars as objective criteria needed to assess the accuracy of the data in the final processing of geomagnetic observatory data. The method of comparison of two series of data is used: one obtained by the scalar magnetometer installed in the observatory as a mandatory stationary device, and the other obtained during measurements with a mobile magnetometer at the desired points in space. Compensation of temporal changes of the geomagnetic field by time-scaling the measurement readings of the mobile magnetometer relative to one reference value and thus, bringing them to one selected and fixed time epoch. Special geometric scheme of mobile measurements in the space around the pillars with magnetometer sensors or at important points in space. A rough estimate of method errors. Based on the analysis of the obtained data, the efficiency of the method and its acceptable potential accuracy were confirmed. We obtained approximate numerical values of the differences in the geomagnetic field induction between the pillars on which the magnetometer sensors are installed. Further increase in the accuracy of determining these differences is possible using modern devices of high accuracy and GPS-synchronization of mobile measurements.
Ice sheet velocity tracking by Sentinel-1 satellite images at Graham Coast Kyiv Peninsula
Authors:   Odesa Mechnikov National University, Odesa, 65082, Ukraine, Kadurin S. , Andrieieva K. ,   Odesa Mechnikov National University, Odesa, 65082, Ukraine
Published: August 2021

The study of Antarctic glaciers and ice sheets velocity is one of the most discussed topics. Such high interest in this topic is primarily because the ice from the Antarctic glaciers, which gets to the ocean, significantly affects the ocean level and the global climate. Development of modern satellite technologies for Earth remote sensing made it possible to elaborate a number of methods for ice sheets’ displacements estimation and calculation of such displacements velocities. This work uses remote sensing data from the satellite system Copernicus Sentinel-1 to estimate the ice cover velocities in the Kyiv Peninsula in the time interval from December 2020 to March 2021. To this end, 10 radar images of the study area from early December to the end of March were used with an interval of 12–14 days. All selected images were analyzed in pairs to establish changes on the surface for the selected time interval. GRD-format images from Copernicus Sentinel-1 satellite, corrected for Earth's ellipsoid shape, were used. Based on the offset tracking operation, we calculated the speeds of ice cover movements within the Kyiv Peninsula for each pair of images with approximately two weeks' time difference. As a result, the speed of ice movements varies considerably and at the glacier mouth can reach 3.5–4 meters per day. Also, the rate of ice displacement in the glacier body changed over time. Thus, the highest ice velocities were in the glacier's mouth. However, short-term time intervals of intensification were recorded for the rear and even the marginal parts of the glaciers in contact with the ice sheet. Thus, the lowest part of the glacier activating sequence leads to the upper part shifting. Notably, this increase in the displacement of ice cover was recorded in February, one of the warmest months in this part of Antarctica.
FINITE ELEMENT ANALYSIS PADA DINDING PENAHAN TANAH SIMPANG UNDERPASS UNIVERSITAS LAMPUNG
Authors: Sahfitri Putri Indah
Published: August 2021

Dinding Penahan Tanah yang berfungsi untuk menahan tanah lepas atau alami dan mencegah keruntuhan tanah yang miring atau lereng yang kemantapannya tidak dapat dijamin oleh lereng tanah itu sendiri. Studi ini menganalisis perilaku deformasi yang terjadi pada dinding penahan tanah Proyek Underpass Universitas Lampung dari STA 0+80 s/d 0+160 dengan menggunakan metode Finite Element Analysis (FEA). Dinding penahan tanah kantilever setinggi 5,27m pada STA 0+140 dipilih pada pemodelan ini. Dinding berfungsi untuk menahan gaya-gaya vertikal di atasnya dan gaya horizontal dibelakang dinding. Pengaruh beban gempa juga dimasukkan dalam analisis. Hasil menunjukkan bawah dinding aman terhadap gaya-gaya yang bekerja dengan faktor keamanan sebesar 1,351 (lebih besar dari 1,25 sebagai syarat minimum) dengan total deformasi yang terjadi akibat beban lajur dan beban gempa sebesar 1,43 meter.
ANALISIS PENGARUH JUMLAH SUDU TERHADAP EFISIENSI TURBIN PELTON DENGAN TEKANAN KONSTAN
Authors: Tonadi Een
Published: August 2021

One of the renewable energy sources that can be used for electricity generation is the Pelton turbine. The purpose of this study was to determine the effect of the number of blades on the efficiency of a Pelton turbine with constant pressure. This research was conducted at the Unihaz mechanical engineering laboratory by varying the number of blades, namely 9 blade turbines and 12 blades. Tests were carried out by giving load gradually to the turbine until the turbine rotor rotation stopped rotating. The results show that in the turbine test with blades 9 the maximum rotation achieved is 698.2 rpm and the maximum rotor rotation is 714.5 rpm at blade 12. Likewise, the torque coefficient and power coefficient achieved by the turbine with 12 are greater when compared to the 9 blades. Meanwhile, the efficiency that can be achieved by turbines with 9 blades is 71% and at 12 blades is 79%. From this it can be concluded that the number of blades affects the rotation, torque coefficient, power coefficient and efficiency of the Pelton turbine with constant pressure.
PENILAIAN KEPUASAN PELANGGAN DENGAN APLIKASI SURVEI PADA PDAM KOTA BENGKULU
Authors: Khairil Khairil
Published: August 2021

Customer satisfaction is a major reason in the service or goods business. The company will get a big profit if the customer is satisfied with the ideal service provided. The purpose of this study was to find the level of satisfaction of the PDAM's performance on customer service by making an online satisfaction survey application. The research method used is system requirements analysis, designing system requirements, coding translating the system with a programming language, implementing the system and maintaining any changes to the system. The results of the study show that the satisfaction survey application can make it easier for customers to send complaints about the service quality of PDAM Kota Bengkulu. With the PDAM polling application, it is faster to take action according to complaints from customers.
De la teoría narrativa de la identidad a los principios del pensamiento complejo de Morín
Authors: Bravo-Huaynates Guido
Published: August 2021

El presente artículo propone un recorrido teórico de la discusión sobre la identidad personal, que se inicia considerando el punto de vista empirista, expresado en los planteamientos de Locke s. XVII y Hume s. XVIII, en esta línea argumentativa, también se recogen las tres tesis de Parfitt (1986) sobre la identidad personal, que intentan reducir la identidad a la experiencia almacenada en un cerebro y, por tanto, destaca el predominio absoluto de la posición epistemológica de la identidad. Luego, se contrapone esta posición con la Teoría Narrativa de Ricoeur, (1996) quien refuta las tesis de Parfitt, señalando aporías en el interior mismo del armazón intelectual de las tesis referidas. Luego, de haber neutralizado el proyecto de Parfitt, Ricoeur plantea la dualidad “carácter y promesa” como modelos opuestos de Identidad, para ello, el citado autor recupera las nociones de “ídem e ipse” como constituyentes del primer modelo de identidad personal, el mismo que considera como invariante relacional, y lo opone a la “promesa”, siendo éstos, dos modelos, con los cuáles propone una Teoría de Identidad Narrativa. La metodología empleada considera un patrón inductivo y cronológico. Como fuente principal para el recojo de datos se tomó en cuenta el análisis documental, asimismo la experiencia recogida a lo largo del doctorado en Pensamiento Complejo de Multiversidad Mundo Real y la experiencia laboral y profesional. Se encontró que Ricoeur logra establecer la reconciliación entre la ontología y la epistemología del ser en la discusión sobre la identidad personal, con lo cual ubica la discusión de la identidad en el campo de la complejidad. Se concluye que, a partir de esta reconciliación, pueden considerarse puntos de contacto o puentes de abordaje de dicha teoría a partir de los Principios del Pensamiento Complejo de Morín (1994).
The Osteoporotic Condition as a Predictive Factor for Hemorrhagic Transformation in Acute Cardioembolic Stroke
Authors: Won Yu Deok , Kim Jae-Min , Ryu Je-Il , Koh Seong-Ho , Han Myung-Hoon , Cheong Jin-Hwan
Published: August 2021

Objective : Hemorrhagic transformation (HT) can be occurred after acute cerebral infarction. HT can worse symptoms in severe cases and adversely affect long-term prognosis. As bone and vascular smooth muscle are composed of type 1 collagen, we aimed to identify a potential relationship between bone mineral density (BMD) and HT after acute cardioembolic stroke.Methods : As an indicator of BMD, we used mean frontal skull Hounsfield unit (HU) values on brain computed tomography (CT). Multivariative hazard ratios were calculated using Cox regression analysis to identify whether the osteoporotic condition was an independent predictor of HT after acute cardioembolic stroke.Results : This 11-year analysis enrolled 506 patients who diagnosed as acute cardioembolic infarction. The first tertile of skull HU value was an independent predictor of HT development compared to the third tertile (hazard ratio, 2.12; 95% confidence interval, 1.13–3.98; p=0.020). We observed no interactions between age and skull HU with respect to HT statistically.Conclusion : The results of this study revealed an association between osteoporotic conditions and HT development after acute cardioembolic stroke. A convenient method to measure the cancellous bone HU value of the frontal skull using brain CT images may be useful for predicting HT in patients with acute cerebral infarction.
Evaluación del impacto de la integración de vehículos eléctricos en un circuito de distribución utilizando OpenDSS
Authors: Barrios Dariel , Sáez Yessica , Collado Edwin , González Guadalupe
Published: August 2021

La llegada de vehículos eléctricos a Panamá va en aumento y se estima que para el 2030 de un 10% a un 20% la flota de vehículos privados será eléctricos, por lo que es necesario realizar un estudio para conocer los efectos que tendrá una recarga masiva de vehículos en las redes de distribución. En este trabajo se realizó un análisis de los parámetros eléctricos de la red, y las consecuencias que trae la variación de estos en los conductores y los transformadores en un sistema de distribución de energía. El análisis se enfocó en el sector residencial, con dos casos de estudio, utilizando data del comportamiento real de residencias en Panamá. Los resultados obtenidos demuestran que es indispensable evaluar las redes de distribución de nuestro sistema eléctrico nacional, para que exista una coordinación entre lo propuesto en las políticas energéticas nacionales y la realidad de la planificación, mantenimiento y operación de las redes de distribución eléctrica.
Hallazgos preliminares sobre la eficacia del programa Crianza Reflexiva para cuidadores de niños entre 4 y 12 años de edad
Authors: Alkabes-Esquenazi Louise , Díaz-Hernández Rubén , Zapata Johana , Oviedo Diana C. , González Flores Sergio
Published: August 2021

El Programa Crianza Reflexiva es un método para fomentar en los cuidadores, una mejor conexión, una mayor curiosidad en el mundo interno de los niños y un mayor disfrute de las interacciones con sus hijos. Los cuidadores, al estar conscientes de los estados mentales de sus hijos y de los suyos propios, cultivan la función reflexiva y/o mentalización y la seguridad emocional de ellos. El objetivo de esta investigación es medir la efectividad del programa Crianza Reflexiva en cuidadores de niños de 4 a 12 años, en la ciudad de Panamá. Se realizó un ensayo controlado aleatorizado con tres mediciones, un pre-test, una post-test y un follow-up a tres meses. Una muestra de cuarenta cuidadores de niños entre 4 y 12 años de edad, fueron incluidos en el estudio y asignados de manera aleatoria a uno de dos grupos: control (n=20) y experimental (n=20). En los tres momentos de medición los participantes completaron cuestionarios de autoreporte para medir el estrés parental (PSI-SF), la eficacia parental (BPES), la función reflexiva parental (PRFQ) y la regulación emocional de niños (SDQ y ERC). Los resultados preliminares obtenidos mediante modelos de efectos mixtos permiten identificar que el programa de crianza reflexiva tuvo un efecto significativo, sobre el interés y curiosidad de los padres acerca de los estados mentales de sus hijos, sobre el estrés parental, y sobre los problemas externalizantes de sus hijos. Los efectos se mantuvieron a los tres meses de seguimiento. Estos hallazgos aportan evidencia sobre la efectividad del programa Crianza Reflexiva
Ideación suicida, síntomas depresivos e involucramiento afectivo en adolescentes escolarizados del 2019
Authors: Sánchez, M. Maricarmen
Published: August 2021

Introducción. La adolescencia es una etapa donde se presentan múltiples cambios físicos, sociales y psicológicos, y se observa mayor vulnerabilidad a experimentar condiciones de salud mental y conductas de riesgo que pueden conducir a presentar ideación suicida. El objetivo de este estudio consistió en realizar un cribado sobre la presencia de ideación suicida, síntomas depresivos e involucramiento afectivo. Método. No experimentaltransversal de tipo descriptivo-correlacional. La muestra fue de 122 adolescentes con edades entre 15-18 años. Resultados. El 30.3% de adolescentes reportó presencia de ideación suicida. De este grupo con ideación suicida el 70.3% presentó sintomatología depresiva en niveles moderados y graves. En cuanto al involucramiento afectivo funcional, el 51.4% lo presenta y el 48.6% reporta ausencia; el aspecto de involucramiento disfuncional, el 45.6% lo presenta y el 48.6% reporta ausencia. Se encontró una correlación negativa promedio entre depresión e involucramiento afectivo funcional (r =-0.48), y una correlación positiva baja entre depresión e involucramiento afectivo disfuncional (r=0.14). Conclusiones. Los adolescentes reportaron presencia de ideación suicida y síntomas depresivos altos, de igual manera se observa que mucho de estos adolescentes no perciben dentro de su entorno familiar vínculos afectivos que puedan cumplir un rol protector. Se observó lo vital que es indagar sobre la presencia de la ideación suicida en ámbitos escolares.
USO DE APLICACIONES MÓVILES PARA GESTIÓN DE PEDIDOS Y HÁBITOS DE CONSUMO EN RESTAURANTES
Authors: Caballero Ricardo , De León Marcos , Espinosa Karla , Gómez David , Miranda Dennis , Miranda Mauriseth , Ortíz Milagros
Published: August 2021

Debido a las restricciones implementadas para evitar la propagación de COVID-19, muchos restaurantes enfrentaron desafíos como cierres temporales o permanentes, disminución de ingresos y gastos en nuevos equipos sanitarios. Para mantener una alta competitividad, los restaurantes tuvieron que repensar la forma de llegar a los clientes sin ningún contacto. Por lo tanto, se incrementó el uso de aplicaciones móviles para la gestión de pedidos, así como los servicios de entrega y recogida. El objetivo de esta investigación es describir nuevos hábitos de consumo en restaurantes de la provincia de Chiriquí durante el inicio de la pandemia.
Impact of an IUCN national Red List of threatened flora on scientific attention
Authors: Andrade RS , Freitas L
Published: August 2021

Red Lists are thought to attract attention to the conservation of threatened species. Determining the impact of these lists on the attention of scientists is a matter of consequence for biodiversity conservation. We evaluated trends in mentions of Brazilian angiosperm plants in the biodiversity conservation literature and tested the effect of the Red List of Brazilian Flora (RLBF) publication on these mentions. We collected mentions in the literature available in Google Scholar from the years 1990-2020, for 2449 Brazilian angiosperm species assessed in different IUCN categories. We used a Bayesian structural time-series method to test the effect of the RLBF publication on the number of mentions for the set of species in the IUCN categories, angiosperm families, and plants of commercial interest. The results showed a gap in mentions for many threatened and Data Deficient species in the scientific literature. We also found that the mentions were biased toward species of commercial interest and were unrelated to their threat status. Publication of the RLBF positively affected the number of mentions for IUCN threat categories and for more than half of the angiosperm families. These results were obtained after a few species of commercial interest were excluded from each treated group. This study suggests that the Red List assessments are essential to determine priorities for resource allocation to scientific activities. However, this effect was not sufficient to reduce the bias in scientific attention. Our findings support the need to stimulate more effective programs to fund research on threatened plant species.
Activity of paraoxonase 1 and lipid profile in healthy children
Authors: Sumegová K , Nagyová Z , Waczulíková I , Žitňanová I , Ďuračková Z
Published: August 2021

Paraoxonase 1 (PON1) seems to have a relevant role in detoxifying processes and in atherosclerosis. The aim of this study was to determine PON1 activity, the total antioxidant capacity, as well as entire lipid profile in children for screening of possible risk of atherosclerosis development. Serum PON1 arylesterase/paraoxonase activities were determined spectrophotometrically. The total antioxidant capacity of the serum was measured by TEAC method. Parameters of lipid profile were analyzed by routine laboratory methods. It has been shown that PON1 arylesterase/ paraoxonase activities were very similar to values found in adults. In children, no significant correlation between PON1 arylesterase activity and HDL was observed. PON1 paraoxonase activity correlated only with atherogenic index. PON1 arylesterase activity was significantly higher in girls than in boys. The antioxidant capacity was inversely related to the body mass index. In this study, PON1 activity was determined in healthy children aged 11 to 12 years and we found a similarity in PON1 activities of children and adults. Moreover, the results of our study support the hypothesis that higher body weight of children may contribute to a greater risk for development of atherosclerosis in which oxidative stress plays a role.
Distribution and interrelationship of ubiquitin proteasome pathway component activities and ubiquitin pools in various porcine tissues
Authors: Patel MB , Majetschak M
Published: August 2021

The ubiquitin-proteasome pathway fulfills major biological functions, but its physiologic tissue distribution and the interrelationship between pathway component activities and ubiquitin pools are unknown. Therefore, we analyzed free and conjugated ubiquitin, ubiquitin-protein ligation rates (UbPL) and chymotryptic- and tryptic-like proteasome peptidase activities in porcine skeletal muscle, heart, lung, liver, spleen and kidney (n=5 each). There were considerable differences between tissues (p<0.05 for all parameters). Lung and spleen showed high levels of free and conjugated ubiquitin and high UbPL. Proteasome activities were highest in kidney and heart. There were linear relationships between tryptic-like and chymotryptic-like proteasome peptidase activities (r(2) = 0.624, p<0.001) and between free and conjugated ubiquitin tissue levels (r(2) = 0.623, p<0.001). Tissue levels of free and conjugated ubiquitin correlated linear with UbPL (p<0.005), but they were not correlated with proteasome peptidase activities. The results suggest that tissue ubiquitin pools are tightly regulated and indicate a constant proportion of conjugated ubiquitin. They further support the hypothesis that ubiquitin-protein ligase systems, and probably deubiquitylating enzymes, are key regulators of ubiquitin homeostasis. The detected differences are suggestive of tissue-specific roles of ubiquitin-proteasome pathway components. Besides the known importance of the ubiquitin proteasome pathway in heart, kidney and the immune system, the results suggest the lung as another organ in which ubiquitin proteasome pathway components may also significantly contribute to disease processes.
Diurnal variation of 6β-hydroxycortisol in cardiac patients
Authors: Mičuda S , Šišpera L , Hodač M , Pařízek P , Fuksa L , Brčáková E , Cerman J , Cermanová J , Martínková J
Published: August 2021

The 24-hour urinary excretion of 6-beta-hydroxycortisol (6beta-OHC) and the urinary ratio of 6beta- hydroxycortisol/cortisol (6beta-OHC/UFC) have been proposed as noninvasive probes for human cytochrome P450 3A4 isoform (CYP3A4). In this study, we evaluated within- and between-day variability of 6beta-OHC excretion and 6beta-OHC/UFC ratio in nine Caucasian men with cardiac disease. Each study participant was asked to collect 24-hour urine specimens during four consecutive days in five standardized time intervals. Concentrations of UFC and 6beta-OHC were determined by immunoassay and the high-performance liquid chromatographic (HPLC) method, respectively. The HPLC method was accurate and precise, as indicated by the recovery rate of 96.5-103.3 % and less than 5.2 % and 6.3 % of the coefficient of variation for within-run and between-run assay, respectively. In patients, diurnal variations in UFC and 6beta-OHC excretion were parallel. Consequently, 6beta-OHC/UFC ratio remained stable during the day. Both, 6beta-OHC excretion and 6beta-OHC/UFC ratio showed significant relationship between 24-hour value and values measured in corresponding collection periods with best correlations obtained from night interval (22.00-06.00, r = 0.86-0.91). These results indicated that urinary 6beta-OHC excretion and 6beta-OHC/UFC ratio measured in overnight/morning urine could precisely reflect 24-hour values even in severely ill patients. In addition, a simple and sensitive HPLC method was described for determination of 6beta-OHC in urine.
Time-Resolved Monitoring of the Oxygen Transfer Rate of Chinese Hamster Ovary Cells Provides Insights Into Culture Behavior in Shake Flasks
Authors: Ihling Nina , Munkler Lara Pauline , Berg Christoph , Reichenbächer Britta , Wirth Johannes , Lang Dietmar , Wagner Roland , Büchs Jochen
Published: August 2021

Cultivations of mammalian cells are routinely conducted in shake flasks. In contrast to instrumented bioreactors, reliable options for non-invasive, time-resolved monitoring of the culture status in shake flasks are lacking. The Respiration Activity Monitoring Respiration Activity Monitoring System system was used to determine the oxygen transfer rate (OTR) in shake flasks. It was proven that the OTR could be regarded as equal to the oxygen uptake rate as the change of the dissolved oxygen concentration in the liquid phase over time was negligibly small. Thus, monitoring the oxygen transfer rate (OTR) was used to increase the information content from shake flask experiments. The OTR of a Chinese hamster ovary cell line was monitored by applying electrochemical sensors. Glass flasks stoppered with cotton plugs and polycarbonate flasks stoppered with vent-caps were compared in terms of mass transfer characteristics and culture behavior. Similar mass transfer resistances were determined for both sterile closures. The OTR was found to be well reproducible within one experiment (standard deviation <10%). It correlated with changes in cell viability and depletion of carbon sources, thus, giving more profound insights into the cultivation process. Culture behavior in glass and polycarbonate flasks was identical. Monitoring of the OTR was applied to a second culture medium. Media differed in the maximum OTR reached during cultivation and in the time when all carbon sources were depleted. By applying non-invasive, parallelized, time-resolved monitoring of the OTR, the information content and amount of data from shake flask experiments was significantly increased compared to manual sampling and offline analysis. The potential of the technology for early-stage process development was demonstrated.
Role of PDGF-A/B Ligands in Cardiac Repair After Myocardial Infarction
Authors: Kalra Kunal , Eberhard Joerg , Farbehi Nona , Chong James J. , Xaymardan Munira
Published: August 2021

Platelet-derived growth factors (PDGFs) are powerful inducers of cellular mitosis, migration, angiogenesis, and matrix modulation that play pivotal roles in the development, homeostasis, and healing of cardiac tissues. PDGFs are key signaling molecules and important drug targets in the treatment of cardiovascular disease as multiple researchers have shown that delivery of recombinant PDGF ligands during or after myocardial infarction can reduce mortality and improve cardiac function in both rodents and porcine models. The mechanism involved cannot be easily elucidated due to the complexity of PDGF regulatory activities, crosstalk with other protein tyrosine kinase activators, and diversity of the pathological milieu. This review outlines the possible roles of PDGF ligands A and B in the healing of cardiac tissues including reduced cell death, improved vascularization, and improved extracellular matrix remodeling to improve cardiac architecture and function after acute myocardial injury. This review may highlight the use of recombinant PDGF-A and PDGF-B as a potential therapeutic modality in the treatment of cardiac injury.
Efficient Colorimetric Fluoride Anion Sensor Based on π-Conjugated Carbazole Small Molecule
Authors: Deng Zhifeng , Wang Cheng , Li Junqiang , Zheng Meng
Published: August 2021

The ability to detect fluoride anions with high selectivity and sensitivity by using the naked eye is crucial yet challenging. In this study, a novel, simple conjugated organic dye, N-tert-butyldimethylsilyl-3,6-diiodocarbazole (CA-TBMDS) was developed and used for the first time as a colorimetric sensor for fluoride. CA-TBMDS was found to be a highly sensitive fluoride chemosensor, with a detection limit as low as 3 × 10−5 M. The reaction of CA-TBMDS with fluoride anions in a tetrahydrofuran solution resulted in a color change from colorless to yellow under ambient light, which can be discriminated by the naked eye. The sensor operated via intermolecular proton transfer between the amide units and the fluoride anion, as confirmed by proton nuclear magnetic resonance titration. CA-TBMDS is not only highly sensitive to fluoride anions, but also exhibits high sensitivity in the presence of various ions. This work demonstrates that N-butyldimethylchlorosilane-based organic dyes have prospective utility as a type of fluoride anion chemosensor.
Safety of a Novel Listeria monocytogenes-Based Vaccine Vector Expressing NcSAG1 (Neospora caninum Surface Antigen 1)
Authors: Pownall William Robert , Imhof Dennis , Trigo Nerea Fernandez , Ganal-Vonarburg Stephanie C. , Plattet Philippe , Monney Camille , Forterre Franck , Hemphill Andrew , Oevermann Anna
Published: August 2021

Listeria monocytogenes(LM) has been proposed as vaccine vector in various cancers and infectious diseases since LM induces a strong immune response. In this study, we developed a novel and safe LM-based vaccine vector platform, by engineering a triple attenuated mutant (Lm3Dx) (ΔactA, ΔinlA, ΔinlB) of the wild-type LM strain JF5203 (CC 1, phylogenetic lineage I). We demonstrated the strong attenuation of Lm3Dx while maintaining its capacity to selectively infect antigen-presenting cells (APCs)in vitro. Furthermore, as proof of concept, we introduced the immunodominantNeospora caninum(Nc) surface antigen NcSAG1 into Lm3Dx. The NcSAG1 protein was expressed by Lm3Dx_SAG1 during cellular infection. To demonstrate safety of Lm3Dx_SAG1in vivo, we vaccinated BALB/C mice by intramuscular injection. Following vaccination, mice did not suffer any adverse effects and only sporadically shed bacteria at very low levels in the feces (<100 CFU/g). Additionally, bacterial load in internal organs was very low to absent at day 1.5 and 4 following the 1stvaccination and at 2 and 4 weeks after the second boost, independently of the physiological status of the mice. Additionally, vaccination of mice prior and during pregnancy did not interfere with pregnancy outcome. However, Lm3Dx_SAG1 was shed into the milk when inoculated during lactation, although it did not cause any clinical adverse effects in either dams or pups. Also, we have indications that the vector persists more days in the injected muscle of lactating mice. Therefore, impact of physiological status on vector dynamics in the host and mechanisms of milk shedding requires further investigation. In conclusion, we provide strong evidence that Lm3Dx is a safe vaccine vector in non-lactating animals. Additionally, we provide first indications that mice vaccinated with Lm3Dx_SAG1 develop a strong and Th1-biased immune response against the Lm3Dx-expressed neospora antigen. These results encourage to further investigate the efficiency of Lm3Dx_SAG1 to prevent and treat clinical neosporosis.
The Predictive Value of N-Terminal Probrain Natriuretic Peptide for Infection in Patients With Acute Myocardial Infarction
Authors: Dai YiNing , Wan XiaoLiang , Liu Can , Duan ChongYang , Shao Shuai , Chen HongHuan , Wang Litao , Lin JiJin , Xue Ling , Chen JiYan , He PengCheng , Liu YuanHui , Tan Ning
Published: August 2021

Background: Infections increase the risk of poor outcomes in patients with ST-elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI). However, predicting patients at a high risk of developing infection remains unclear. Moreover, the value of N-terminal probrain natriuretic peptide (NT-proBNP) for predicting infection is still unknown. Thus, we aimed to assess the relationship between NT-proBNP and the following development of infection, and clinical adverse outcomes in patients with STEMI undergoing PCI.

Methods: STEMI patients undergoing PCI were consecutively enrolled from January 2010 to July 2016 and divided into groups according to baseline NT-proBNP levels: tertiles T1 (<988 pg/mL), T2 (988–3520 pg/mL), and T3 (≥3520 pg/mL). The primary endpoint was infection during hospitalization.

Results: A total of 182 (27%) patients developed in-hospital infection. The incidence of infection increased from T1 to T3 (10.5, 17.7, and 54.5%, P < 0.001). NT-proBNP was an independent risk factor (adjusted odds ratio = 1.39, 95% confidence interval (CI) = 1.12–1.73, P = 0.003) and presented accurately predicting infection (area under curve = 0.774). Multivariate cox analysis showed that NT-proBNP was a significant risk factor for major adverse clinical events (MACE) at follow-up (adjusted HR = 1.92, 95% CI = 1.61–2.29, P < 0.001).

Conclusion: The baseline NT-proBNP level has a good predictive value for infection and MACE in STEMI patients undergoing PCI.
Formation of Bubble-Loop Complexes During Helium Radiation in Fe-9Cr Steel
Authors: Shi Tiantian , Liu Wenbo , Su Zhengxiong , Yan Xu , Lu Chenyang , Yang Zhaoxi , He Xinfu , Yan Wei , Yun Di
Published: August 2021

In the present study, the Fe-9Cr model alloy was irradiated with 240 keV He2+ at 550°C with a dose of 0.5 dpa at the peak damage region. The depth distribution of bubbles in Fe-9Cr alloy was investigated by transmission electron microscopy (TEM). The experimental results revealed that the spatial distribution of bubbles along the depth is different. In the region with higher helium concentration and irradiation dose, the bubbles inclined to be situated inside the plane of loops, forming a structure of “bubble-loop complex.” However, in regions where the helium concentration and irradiation dose are relatively low, the number of “bubble-loop complexes” significantly decreased. In addition, the Burgers vector of “bubble-loop complexes” was identified as <100> type. Radiation-induced enrichment of Cr atoms at the “bubble-loop complexes” was also quantitatively estimated by energy-dispersive X-ray spectroscopy (EDS) in the scanning TEM mode.
Transcription Factors of CAT1, EFG1, and BCR1 Are Effective in Persister Cells of Candida albicans-Associated HIV-Positive and Chemotherapy Patients
Authors: Aboualigalehdari Elham , Tahmasebi Birgani Maryam , Fatahinia Mahnaz , Hosseinzadeh Mehran
Published: August 2021

Background

Biofilm is an accumulation of cells, which are formed on mucosal surfaces of the host as well as on medical devices. The inherent resistance of Candida strains producing biofilms to antimicrobial agents is an important and key feature for biofilm growth, which can lead to treatment failure. This resistance is due to the regulatory increase of the output pumps, the presence of extracellular matrix, and the existence of persister cells. Persister cells are phenotypic variants that have MICs similar to antibiotic-sensitive populations and are able to tolerate high doses of antibiotics. The current study investigated the possible role of EFG1, BCR1, and CAT1 in the establishment or maintenance of persister cells in Candida albicans strains that produce biofilms.

Methods

After identifying Candida isolates by molecular methods, C. albicans isolates were confirmed by sequencing. Isolation of persister cells and determination of their MIC were performed by microdilution method. Then, RNA extraction and cDNA synthesis were performed from 60 C. albicans isolates under promoting and inducing conditions. Afterward, the mean expression of BCR1, EFG1, and CAT1 genes in both persister and non-persister groups was calculated using real-time qPCR. Phylogeny tree of persister and non-persister group isolates was drawn using ITS fragment.

Results

A total of 77 persister isolates were taken from the oral cavity of HIV patients as well as from patients undergoing chemotherapy. Biofilm intensity in persister isolates separated from HIV-infected patients was different from the non-persister group. The mean fold change of BCR1 (10.73), CAT1 (15.34), and EFG1 (2.41) genes in persister isolates was significantly higher than these genes in isolates without persister.

Conclusion

It can be concluded that the most important factor in the production of persister cells is biofilm binding and production, not biofilm development or mature biofilm production, which was found in the expression of BCR1 gene without change in the expression of EFG1 gene in the persister group. Also, catalase plays an essential role in the production of persister in C. albicans biofilm producers with ROS detoxification.