bluuebunny/crossref_metadata_2025_split huggingface dataset:
Calreticulin – a multifaced protein
Authors: Kanduła Zuzanna , Lewandowski Krzysztof 
Published: May 2021

Summary
Calreticulin (CALR) is a highly conserved multi-function protein that primarily localizes within the lumen of the endoplasmic reticulum (ER). It participates in various processes in the cells, including glycoprotein chaperoning, regulation of Ca2+ homeostasis, antigen processing and presentation for adaptive immune response, cell adhesion/migration, cell proliferation, immunogenic cell death, gene expression and RNA stability. The role of CALR in the assembly, retrieval and cell surface expression of MHC class I molecules is well known. A fraction of the total cellular CALR is localized in the cytosol, following its retro-translocation from the ER. In the cell stress conditions, CALR is also expressed on the cell surface via an interaction with phosphatidylserine localized on the inner leaflet of the plasma membrane. The abovementioned mechanism is relevant for the recognition of the cells, as well as immunogenicity and phagocytic uptake of proapoptotic and apoptotic cells.
Lastly, the presence of CALR exon 9 gene mutations was confirmed in patients with myeloproliferative neoplasms. Their presence results in an abnormal CALR structure due to the loss of its ER-retention sequence, CALR extra-ER localisation, the formation of a complex with thrombopoietin receptor, and oncogenic transformation of hematopoietic stem cells. It is also known that CALR exon 9 mutants are highly immunogenic and induce T cell response. Despite this fact, CALR mutant positive hematopoietic cells emerge. The last phenomenon is probably the result of the inhibition of phagocytosis of the cancer cells exposing CALR mutant protein by dendritic cells.
Inhaled corticosteroids and incident pneumonia in patients with asthma: Systematic review and meta-analysis
Authors: Bansal Vikas , Mangi Muhammad A. , Johnson Margaret M. , Festic Emir 
Published: May 2021

<p><strong>Objectives</strong>. To systematically review all available studies on inhaled corticosteroid use and incident pneumonia in asthma patients. <strong>Methods</strong>. We performed a literature search from January 1, 1993, through August 15, 2015, using PubMed, Medline, CENTRAL, EMBASE, Scopus, ISI, Regulatory Documents, Web of Science and manufacturers’ web clinical trial registries with multiple search terms. We included studies that compared the risk of incident pneumonia among patients utilizing and not utilizing inhaled corticosteroids. We then summarized risk estimates into two random-effect meta-analyses; one including randomized controlled trials and another one including observational studies. <strong>Results</strong>. Fourteen studies were estimable; ten randomized controlled trials included 19,098 participants and four observational studies included 44,016 participants. There was no heterogeneity in randomized trials and summed risk ratio demonstrated the use of inhaled corticosteroids was protective of pneumonia; risk ratio 0.74, 95% CI 0.57to 0.95, p=0.02. On the contrary, observational studies showed summed odds ratio of 1.97; 95% CI 1.87to 2.07, p&lt;0.0001, I²=0%, suggesting increased risk of pneumonia with use of inhaled corticosteroids in asthma patients. <strong>Conclusions</strong>: Inhaled corticosteroids<br />are associated with decreased risk of incident pneumonia in patients with asthma based on meta-analysis of available randomized trials. Although observational studies in similar patients suggested higher risk of pneumonia, the inherent methodological limitations confer lower grade of confidence in these studies.</p>
Brain abscess due to Aggregatibacter aphrophilus and Bacteroides uniformis
Authors: Bogdan Maja , Zujić Atalić Vlasta , Hećimović Ivan , Vuković Dubravka 
Published: May 2021

<p><strong>Objective</strong>. The aim of this report was to describe the occurrence of a bacterial brain abscess in a healthy individual, without any predisposing condition. <strong>Case report</strong>. A thirteen-year old boy was admitted to the Department of Neurosurgery after the onset of vomiting, headache and dizziness. A neurological deficit was detected during the physical examination so urgent magnetic resonance imaging of the brain was performed, revealing an intrahemispheric, right positioned solitary expansive mass with ring enhancement. Purulent material was obtained during osteoplastic craniotomy with total extirpation of the brain abscess. Aggregatibacter aphrophilus and Bacteroides uniformis were isolated. The patient’s general condition improved and the neurological deficit subsided as a result of the prompt recognition and treatment of this life threatening condition. <strong>Conclusion</strong>. To achieve a favourable clinical outcome, prompt recognition and surgical treatment of a brain abscess are of primary importance,followed by administration of appropriate antimicrobial therapy. To our best knowledge, this is the first report of this combination of microorganisms as the cause of a brain abscess.</p>
Pediatric advanced stage nasopharyngeal carcinoma - case report
Authors: Roganović Jelena , Matijašić Nuša , Maurizio Mascarin 
Published: May 2021

<p><strong>Objective</strong>. Nasopharyngeal carcinoma is an extremely rare pediatric malignancy predominantly occurring in adolescent males. Its multifactorial pathogenesis is most strongly associated with the exposure to<br />Epstein-Barr virus in genetically susceptible hosts. In younger patients, more aggressive biological behavior has been observed, although the overall survival is better compared to adults. Due to its rarity and nonspecific clinical presentation, the diagnosis in children is often delayed and misinterpreted. <strong>Case report</strong>. We report a case of a 16-year-old boy with stage IVB nasopharyngeal carcinoma. He presented with a painless palpable neck mass, nasal congestion and a history of occasional epistaxis and headaches. Four years after the completion of a multimodal treatment, the patient is in complete remission. <strong>Conclusion</strong>. Although exceedingly rare, pediatricians should consider nasopharyngeal carcinoma in the differential diagnosis of palpable neck masses, especially in male adolescents. A multidisciplinary approach in the diagnosis, treatment, supportive care and follow-up is of utmost importance.</p>
An Investigation of the Structural Dynamics of a Racing Yacht
Authors: Louarn Frederic , Temarel Pandeli 
Published: May 2021

The dynamic behaviour of a WOR 60 is investigated using three dimensional hydroelasticity theory. Global structural responses (e.g. stresses) in waves are obtained corresponding to the upright as well as to the more realistic heeled sailing configurations, revealing the connection between the ballast keel and the hull as being a critical area of the structure.
For the "dry hull" analysis, a global finite element model has been developed, incorporating the hull and deck shell, the internal structure, the ballast keel and the rig together with rigging loads. The modular nature of the model has been used to assess the relative influence of each of the aforementioned components upon the required characteristic dynamic properties (e.g. natural frequencies and principal mode shapes).
Regarding the "wet hull" analysis, a three dimensional Green's function technique, using pulsating sources distributed over the wetted surface, provides a numerical solution to the case of the yacht sailing in regular waves at arbitrary heading. Principal coordinates for the rigid body motions and flexible distortions of interest are evaluated and the latter are used to obtain the dynamic stresses in waves using modal summation.
This paper will describe the modelling techniques used and discuss the applicability / limitations of hydroelasticity theory regarding this type of structures in the light of the results obtained for the upright and heeled operational conditions, as well as from the point of view of design aspects such as "L" and "T" keel configurations. The ABS design criteria will provide a practical reference for comparing the results from the dynamic analysis.
PCSAIL, A Velocity Prediction Program for a Home Computer
Authors: Martin David E. , Beck Robert F. 
Published: May 2021

An Excel Velocity Prediction Program has been developed to allow for rapid evaluation of yacht performance at the initial design stage. The required input consists of only the basic hull and sail dimensions. Empirical equations, based on these basic dimensions, are used for initial estimates of required hull parameters. As the design progresses the user can easily replace these default values with refined estimates or actual values. Because of its simplicity, and short turn around time, the program has been used as a teaching aid at the University of Michigan. Reconstruction of the program, PCSAIL, may be made with equations and other information provided in the Appendix.
The Excel "Solver" has been found to be a reliable means of finding the equilibrium boat speed and heel angle. It seeks the maximum boat speed by adjusting the sail flattening factor, F, and reef, R, and the lateral location of the "movable crew." In the case of a hinged centerboard, or dagger- board, it will also adjust the draft for maximum boat speed.
For sloop rigs the program will also take in the jib and set the spinnaker, at the appropriate wind angle, in order to gain maximum boat speed. The program plots the speed "polar," and velocity made-good, and determines the tacking angles.
Prácticas universitarias innovadoras sobre las ventajas educativas y desventajas de los entornos MOOC
Authors: Vázquez-Cano Esteban , López-Meneses Eloy , Gómez-Galán José , Parra-González María Elena 
Published: May 2021

Las tecnologías de la información y la comunicación han revolucionado el mundo tal como lo conocíamos antes de su uso y aplicabilidad a la vida diaria. Este uso también se ha trasladado al campo educativo y ha transformado la forma en que se aprende y se enseña hoy. En medio de este panorama, los cursos abiertos masivos en línea emergen como una oportunidad disponible para que todos puedan aprender, lo que ha causado muchos cambios en el campo educativo. Este estudio se presenta como una investigación sobre prácticas universitarias innovadoras para analizar las ventajas y desventajas de estos MOOC en el entorno de la educación superior. Entre las principales ventajas analizadas, destacamos su gratuidad, el establecimiento de redes de colaboración y la flexibilidad horaria, mientras que entre las desventajas podemos destacar el abandono, que algunos cursos no están adaptados o disponibles para dispositivos fáciles o falta de seguimiento. La idea principal es que una vez que se conocen las ventajas y desventajas de los MOOC, se debe alentar a los primeros, dados los grandes beneficios que conllevan para la educación; y, a su vez, tratar de resolver las desventajas que se han visto que conducen al uso de MOOC, a fin de promover la efectividad de su uso.
Information and communication technologies have revolutionized the world as we knew it before its use and applicability to daily life. This use has also moved to the educational field and has transformed the way it is learned and taught today. In the midst of this panorama, Massive Online Open Courses emerge as an opportunity available for everyone to learn, which has caused many changes in the educational field. This study is presented as an investigation into innovative university practices to analyze the advantages and disadvantages of these MOOCs in the Higher Education environment. Among the main advantages analyzed, we highlight its gratuity, the establishment of collaboration networks and time flexibility, while among the disadvantages we can highlight the abandonment, that some courses are not adapted or available for easy devices or lack of follow-up. The main idea is that once the advantages and disadvantages of MOOCs are known, the former should be encouraged, given the great benefits they entail for education; and in turn try to solve the disadvantages that have been seen that lead to the use of MOOCs, in order to promote the effectiveness of their use.
Análisis crítico del concepto “aprendizaje ubicuo” a través de la Cartografía Conceptual
Authors: Velázquez Gatica Belén , López Martínez Rocío Edith 
Published: May 2021

El concepto “aprendizaje ubicuo” se ha criticado por su carácter tecnocéntrico, debido a que enfatiza los aspectos tecnológicos por encima de los educativos. No obstante, una vez que el aprendizaje ubicuo evolucione hacia un concepto educativo, sus aportes podrán alcanzar mayor relevancia y pertinencia en el marco de la ubicuidad y sus aplicaciones en el aprendizaje. Por tal motivo, el objetivo del presente trabajo fue realizar una revisión documental sobre el término aprendizaje ubicuo, para elaborar un análisis crítico que apoye en su desarrollo. Para ello, se utilizó el método de Cartografía Conceptual, a través de un procedimiento en cuatro fases: 1) Búsqueda de documentos pertinentes a la investigación; 2) Definición de criterios de inclusión y exclusión de documentos; 3) Análisis de datos con categorías analíticas (Noción, Caracterización, Categorización, Diferenciación, Clasificación y Vinculación); 4) Interpretación de resultados. El resultado principal sugiere que el aprendizaje ubicuo maduró conceptualmente, debido a la incorporación de dos enfoques: el aprendizaje continuo y el personalizado. No obstante, estos enfoques se basan en ideales del aprendizaje, por lo que es necesario precisar conceptos que apoyen la perspectiva del aprendizaje ubicuo a la hora de establecer prácticas educativas concretas.
The concept of “ubiquitous learning” has been criticized due to its technocentric nature, which emphasizes technological aspects over educational ones. However, once ubiquitous learning evolves into an educational concept, its contributions may become more relevant and pertinent in the context of ubiquity and its applications in learning. For this reason, the objective of this work was to carry out a documentary review on the term ubiquitous learning, to make a critical analysis that supports its development. The Conceptual Cartography method was used, through a four-phase procedure: 1) Search for documents relevant to the research; 2) Definition of inclusion and exclusion criteria for documents; 3) Data analysis with analytical categories (Notion, Characterization, Categorization, Differentiation, Classification and Linkage); 4) Interpretation of results. The main result suggests that ubiquitous learning matured conceptually, due to the incorporation of two approaches: continuous and personalized learning. However, these approaches are based on learning ideals, so it is necessary to specify concepts that support the ubiquitous learning perspective when establishing concrete educational practices.
Compromiso, motivación y persistencia de participantes en xMOOC
Authors: Guajardo-Leal Brenda Edith , Gallardo Córdova Katherina Edith 
Published: May 2021

Los cursos masivos y abiertos en línea (MOOC, por sus siglas en inglés Massive, Open Online Courses) se presentan como una modalidad educativa innovadora, económica y de fácil acceso, que ofrece la oportunidad de democratizar la educación en nuestro tiempo. Si bien el interés en estos cursos está en aumento, la tasa de participación de los estudiantes disminuye significativamente a medida que avanzan en las actividades, por lo que la eficiencia terminal suele ser baja. Este estudio cualitativo con diseño de caso múltiple estudió el compromiso, la motivación y la persistencia de los participantes de xMOOC a través del análisis de voces detalladas y descripción profunda de las perspectivas de los participantes, para comprender mejor las formas en las participan de esta modalidad educativa. Los hallazgos revelaron diferencias entre los grupos de alto, medio y bajo rendimiento en las distintas dimensiones del compromiso y persistencia, así como semejanzas en las necesidades psicológicas básicas de competencia, autonomía y relación. Aunque la muestra fue pequeña, fue posible hacer recomendaciones para la toma de medidas específicas con respecto al diseño, la política, la práctica, la teoría y la investigación posterior en cursos en línea masivos y abiertos.
Massive Open Online Courses (MOOC) are presented as an innovative, affordable and easily accessible educational modality, offering the opportunity to democratize education in our time. While interest in these courses is on the rise, the participation rate of students decreases significantly as they progress through activities, so terminal efficiency is often low. This qualitative study with multiple case design studied the engagement, motivation and persistence of xMOOC participants through detailed voice analysis and in-depth description of participants' perspectives, to better understand the ways in which they participate in this educational modality. The findings revealed differences between the high, medium and low performance groups in the different dimensions of engagement and persistence, as well as similarities in the basic psychological needs of competence, autonomy and relationship. Although the sample was considered small, it was possible to make recommendations for specific actions regarding design, policy, practice, theory, and subsequent research in massive open online courses.
Saberes digitales en el profesorado universitario. Estudio en una escuela mexicana.
Authors: Lara Rivera José Alejandro , Cabero Almenara Julio 
Published: May 2021

Se presenta una investigación empírica que evalúa los saberes digitales en profesores de educación superior, los datos fueron recopilados en una institución mexicana ubicada en el noroeste del país. La muestra es probabilística aleatoria simple compuesta por 224 profesores clasificados desde las variables Edad, Grado académico y Género, ya que, se trabajó con el hipotético de que los conocimientos tecnológicos están relacionados con estos factores. Con la finalidad de buscar relación estadística en el agrupamiento de los datos, se realizó un factorial exploratorio por Kaiser-Meyer-Olkin (KMO) y prueba de esfericidad de Bartlett con el método de extracción de componentes principales y rotación varimax. Se aceptaron solo los factores con un autovalor superior a 1 y un peso factorial por ítem superior al 0.40. Posteriormente se realizaron pruebas estadísticas no paramétricas para identificar relaciones desde las variables de cruce. Los hallazgos dan cuenta de que la Edad de los profesores es un factor diferenciador para la apropiación de saberes digitales.
An empirical research is presented that assesses digital knowledge in higher education teachers, the data was collected in a Mexican institution located in the northwest of the country. The sample is simple random probabilistic composed of 224 teachers classified according to the variables Age, Academic Degree and Gender, since the hypothetical was worked on that technological knowledge is related to these factors. In order to find a statistical relationship in the grouping of data, an exploratory factorial was performed by Kaiser-Meyer-Olkin (KMO) and Bartlett's sphericity test with the principal component extraction method and varimax rotation. Only factors with an eigenvalue greater than 1 and a factorial weight per item greater than 0.40 were accepted. Subsequently, non-parametric statistical tests were performed to identify relationships from the crossover variables. The findings show that the age of the teachers is a differentiating factor for the appropriation of digital knowledge.
EFFECT ON DEGREE OF PHOSPHORIC ACID NEUTRALIZATION ON PROPERTIES OF NITRATE-CONTAINING NITROGEN-PHOSPHORUS-POTASSIUM FERTILIZERS
Authors: Kolpakov Viacheslav M. , Norov Andrey M. , Pagaleshkin Denis A. , Fedotov Pavel S. , Kochetova Inna M. , Petropavlovskiy Igor’ A. 
Published: May 2021

Основной задачей данной работы является обоснование оптимального технологического режима производства нитроаммофоски с уравновешенным содержанием питательных веществ. В статье на примере азотно-фосфорно-калийного удобрения марки 17:17:17 представлены результаты исследования зависимости химического и фазового состава, а также структуры и физико-механических характеристик гранулированных образцов от степени нейтрализации промышленной экстракционной фосфорной кислоты аммиаком, выраженной значением мольного отношения [NH3]:[H3PO4]. Приведены методики синтеза, гранулирования и изучения свойств образцов удобрений. Отмечены особенности процесса гранулирования удобрений, полученных с различной степенью нейтрализации: образцы с мольным отношением от 1,0 до 1,2 налипают на стенки гранулятора, образуя крупные агломераты из отдельных гранул; при увеличении мольного отношения более 1,2 и выше наблюдается стабилизация процесса гранулирования, образуются гранулы близкой к сферичной формы; при значениях мольного отношения более 1,6 полученные гранулы начинают интенсивно истираться между собой в тарелке гранулятора. Определены значения статической прочности и среднего диаметра гранул, слеживаемости и коэффициента гигроскопичности образцов удобрений. Предложено объяснение полиэкстремального характера зависимостей свойств удобрений от степени нейтрализации. Выполнен количественный рентгенофазовый анализ кристаллической фазы при различной степени нейтрализации. Описана зависимость изменения фазового состава кристаллической части удобрений при увеличении степени нейтрализации. Показано влияние примесей, вносимых с экстракционной фосфорной кислотой, на коэффициент гигроскопичности удобрений, измельченных до состояния порошка. Представлены микрофотографии сколов гранул. Предложены оптимальные значения мольного отношения [NH3]:[H3PO4] при получении наиболее востребованных удобрений марки 17:17:17.
THERMOGRAVIMETRIC AND KINETIC STUDY OF FUEL PELLETS FROM BIOMASS OF HERACLEUM SOSNOWSKYI MANDEN
Authors: Polina Irina N. , Mironov Mikhail V. , Belyy Vladimir A. 
Published: May 2021

The comprehensive study of the process of thermal decomposition of fuel pellets from Heracleum Sosnowskyi biomass was carried out. Kinetic parameters of the process were determined based on thermo-gravimetric analysis in comparison with a sample of wood pellets from coniferous wood. The biomass of heracleum Sosnowskyi was collected in the village of Vylgort, Komi Republic, dried to atmospheric-dry state, ground to mean diameter dm<0.25 mm. The elemental composition, the content of the main components, the value of the thermal effect of the initial plant raw materials are determined. The features of the thermal decomposition of samples are established. Kinetic studies of samples pressed at 10 kN were carried out in air environment at heating rate of 5, 10 and 15 °C/min in the temperature range from 25 to 1000 °C using differential methods of Friedman and Ozawa-Flyn-Wall. Comparative analysis of softwood pellets and fuel pellets of hogweed Sosnowskyi confirmed the possibility of using the latter as an independent energy fuel, and as an additive to pellets without significantly reducing their quality characteristics. The results of the presented studies can be used to develop technology and equipment for burning fuel pellets for the purpose of rational extraction of thermal energy.
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