bluuebunny/crossref_metadata_2025 huggingface dataset:
The DETERMINATION OF AMILORIDE VIA QUENCHED CONTINUOUS FLUORESCENCE OF AZO DYE USING LOW-PRESSURE MERCURY LAMP TUBE (UV-LIGHT) AND MULTI SOLAR CELLS AT 2 X 90° AS A DETECTORS
Authors: NAFEA HUDA MUAYAD , TURKEY NAGHAM S.
Published: September 2020

Objective: The aim of the method was to develop a novel, simple and rapid fluorometric method determination of Amiloride (AMD) in pure form and pharmaceutical drugs via fluorescence measurements.

Methods: The method depends on fluorescence quenching of 2H-chromene azo dye (2-(4-nitrophenyl)-N-(4-(phenyldiazenyl)-2H-chromen-4-amine) upon adding Amiloride (AMD) using homemade ISNAG 2 X 90° multi solar cell via low-pressure mercury lamp at two significant wavelengths 184.9 and 253.7 nm combined with continuous flow injection analysis.

Results: Under the optimized conditions, the fluorescence quenching linear working range and percentage linearity (r2%) was (0.03-8 mmol/l) and 98.78 %, respectively. The suggested method was effectively applied to the determination of AMD in two different pharmaceutical drugs and compared with the classical method (UV-vis spectrophotometry at λ=540 nm).

Conclusion: The proposed and established method is simple, direct, and efficient. The statistical comparison results using a t-test at 95% confidence interval that was applied to compare the new and classical method showed there are no significant differences between the two methods.
PREPARATION, CHARACTERIZATION AND STUDIES OF PHYSICOCHEMICAL AND BIOLOGICAL PROPERTIES OF DRUGS COATING LACTOSE IN FLUIDIZED BEDS
Authors: USPENSKAYA E. V. , PLETENEVA T. V. , SYROESHKIN A. V. , TARABRINA I. V.
Published: September 2020

Objective: Study physicochemical properties and activity of biotechnological drugs coating lactose particles in fluidized beds for the development of a prospective approach of their identification.

Methods: Lactose monohydrate as pharmaceutical excipient; affinity-purified polyclonal rabbit antibodies to recombinant human interferon-gamma as a drug substance; Pilotlab fluid bed apparatus was used for lactose powder saturation with solutions of pharmaceutical substances to the point of granulation (pelletizing); inverse light scattering method (2D-LS) for analysis of micron vibrations frequency spectra of samples surfaces for light intensity distribution in time by values of d1, d2, d3 primary descriptors; low angel and dynamic laser light scattering (LALLS, DLS) methods for distribution of lactose-water (LW) supramolecular complexes into volume fractions (micron "size spectra"), using the Master Sizer 2000 instrument and Zeta Sizer Nano ZS instrument in the nanoscale; Spirotox method for research of biological activity to determine the activation energy (Ea) values of cell death in solutions of tested samples.

Results: Changes in 2D-LS scattering time on sample surfaces, described by topological descriptors, made it possible to clearly differentiate the intact lactose from fluidized samples by specific corridors in coordinates di=F(t). The calculated activation energy (Ea) values of cell biosensor death process in solutions of drugs coating lactose allow to characterize the biological activity of it in the initial (by Ea increase) and activated state (by Ea decrease) after the creation of intra-laboratory transmucosal conditions. A unique dimensional spectrum of LW complexes in the nanoscale range was obtained by DLS. The differences between samples in the distribution of LW complexes in the size range from 1 µm to 125 µm was showed by LALLS.

Conclusion: The developed approach, including Сhemometrics, laser and biotesting methods can be used for qualitative the analysis tasks as well as for analytical control of the fluidization process in cases where identifiable pharmaceutical substances are not distinguishable by traditional analytical methods.
NANOPARTICLE FORMULATION OF BIOFLAVONOIDS FOR ENHANCED ANTI-CANCER ACTIVITY
Authors: KUMAR S. SATHESH , SHANMUGASUNDARAM P. , KOMALA M. , BHARGAVI B. , PADMAVATHY J.
Published: September 2020

Among the natural sources, plant origin drugs constitute around 25% which includes various secondary metabolites such as bioflavonoids, alkaloids, terpenes, saponins, glucosides, and lignans. The bioflavonoids belonging to the polyphenol group shows many beneficial effects like hepatoprotective, antioxidant, antibacterial, anticancer, anti-inflammatory and antiviral. The main objective of this article is to collectively present the research data published worldwide about the anticancer activity of bioflavonoids by loading them in novel formulations. Thus, the present review explored the novel formulations of the bioflavonoids with improved pharmacokinetic properties along with the enhanced anticancer activity. The major drawback with bioflavonoids is its poor solubility and bioavailability, which restricts the usage of bioflavonoids in the treatment of cancer in the market worldwide. Novel drug delivery system seems to possess many benefits like site-specific drug delivery along with minimal side effects and improves pharmaceutical and therapeutic properties of drugs compared to a conventional dosage form of bioflavonoids. The scope for improvement of anticancer activity of bioflavonoids by incorporating in novel pharmaceutical formulations like nanoparticles is very high, and it has to be considered as a potential area of research.
COVID-19: EPIDEMIOLOGY, PATHOGENICITY AND GLOBAL UPDATES
Authors: SINGH MANJINDER , NAGPAL MANJU , SINGH VARINDER , SHARMA AMEYA , DHINGRA GITIKA ARORA , MAMAN PARAMJOT , PURI VIVEK
Published: September 2020

Novel coronavirus (COVID-19) is a highly contagious virus that originated from China and has become a major threat in the current time. Presently, finding an effective treatment strategy for COVID-19 is in infancy. Worldwide, numerous clinical trials employing different treatment strategies (antiviral drugs and vaccines) are in progress to develop an effective therapeutic regimen against COVID-19. Literature related to the epidemiology, mortality, pathogenicity, treatment strategies and clinical data was studied and database was collected using various search engines such as j-gate, google scholar, scihub, pubmed, sciencedirect etc. The present review systematically summarises the published information about epidemiology, various stages of pandemic, mortality, pathogenicity, modes of transmission, clinical characteristics, methods of prevention, ongoing treatment strategies and drugs under clinical trials associated with COVID-19 with a hope to avoid possible threatening of the lives of millions of human beings and provide directions for future studies.
WOUND HEALING CONCEPTS: CONTEMPORARY PRACTICES AND FUTURE PERSPECTIVES
Authors: FURTADO SHARON C. , SRINIVASAN BHARATH , ABRAHAM SINDHU
Published: September 2020

The advancements in the development of wound dressings have seen tremendous growth in the past few decades. Wound healing approach has majorly shifted from dry healing to moist healing. There has been a significant advancement in our understanding of the underlying physiology involved in wound healing and the associated systemic factors having a direct or indirect influence on the healing. This has resulted in the development of wound dressings designed to treat specific types of wounds. The present review discusses the physiology of wound healing, followed by different factors that contribute to healing. The advancements in wound dressings with their merits and limitations, newer approaches in wound care i.e., hyperbaric oxygen, negative pressure therapy, skin substitutes and role of growth factors in wound healing, have been highlighted. In addition, more recent approaches for effective wound care like smart devices with sensing, reporting and responding functions are discussed.
A REVIEW ON PROPERTIES, APPLICATIONS AND TOXICITIES OF METAL NANOPARTICLES
Authors: G. SANGEETHA , N. USHA , R. NANDHINI , P. KAVIYA , G. VIDHYA , B. CHAITHANYA
Published: September 2020

Nanotechnology is a broad and novel technology related to all branches of science. However, in the Pharmaceutical industry, it plays an immense role in the drug delivery system. Nanotechnology applied on metal-based drug delivery systems varies; the size ranges from 100 nm or less. Metallic nanoparticles are existing the world from the 4th century. The noble metals, like gold and silver have attracted many researchers in the class of anticancer and anti-microbial. Metallic nanoparticles are not only used in the biomedical applications also have major functions in the domain of textiles, agriculture, photography, etc. Various metals are found in various applications in the biomedical industries. At the same time, the metallic nanoparticles have been evidences of remarkable toxicity in various studies. The rationale behind this topic was that the properties, applications and toxicity of individual metal nanoparticles. As this study have not been compiled and reported. So, in the current review, the gap was filled. The main sources for the preparation of the manuscript are Pubmed, Elsevier and google scholars. Keywords used includes metallic nanoparticles, reported toxicity of metals in drug delivery, applications of metals in drug delivery, history of novel metals in drug delivery, etc. Approximately 400 reviews and academic papers were reviewed to compose the manuscript and sorted by reference to the need for a manuscript.
OCULAR DRUG DELIVERY SYSTEM: CHALLENGES AND APPROACHES
Authors: RAJ VISHAL KUMAR , MAZUMDER RUPA , MADHRA MONIKA
Published: September 2020

The ocular drug delivery deviates through a number of anatomical and physiological barriers, which have been a bottleneck for the ophthalmologists. The ocular barriers, static and dynamic, decrease the absorption of the therapeutic agents and the entry of the xenobiotics. Thus, a conventional ocular dosage form has various disadvantages of its use in ocular diseases. Hence, an ideal ocular delivery system has always been aimed, where the bioavailability of a drug is maintained for a longer period of time. The present review aims to focus on the drawbacks of the conventional ocular therapy and the advantages of designing novel delivery systems, with their certain specific advantages in ocular pharmacokinetics and the enhancement of bioavailability. These novel approaches emphasize on the benefits of various ocular drug delivery systems, like eye ointments, gels and use of viscosity enhancers, prodrugs, penetration enhancers, microparticles, liposomes, niosomes, ocular inserts, implants, intravitreal injections, nanoparticles, nanosuspension, microemulsion, dendrimers, in situ gels, iontophoresis and periocular injections. The compiled data presented in this review will act as a good information resource and reference point for further researches in the field of ocular drug delivery aiming non-invasive sustained release of drugs in the anterior and posterior segments of the eye.
OCULAR DELIVERY OF NATAMYCIN SOLID LIPID NANOPARTICLE LOADED MUCOADHESIVE GEL: FORMULATION, CHARACTERIZATION AND IN VIVO STUDY
Authors: ABDELMONEM REHAB , EL-NABARAWI MOHAMED A. , ATTIA ALSHIMAA M. , TEAIMAA MAHMOUD
Published: September 2020

Objective: This study aimed to develop a novel topical ocular system of natamycin (NAT) by formulating and evaluating of NAT-solid lipid nanoparticle (SLN) loaded on mucoadhesive gels to improve its therapeutic activity and reduce the frequency of dosage to assist patient compliance.

Methods: SLNs were prepared using lipids and Tween 80 or Pluronic F127 as stabilizers via modified high shear homogenization and ultrasound techniques. The prepared SLNs were characterized for particle size (PS), zeta potential (ZP), polydispersity index (PI), and entrapment efficiency percentage (EE %). The morphological examination for chosen SLNs was done using a transmission electron microscope (TEM). Carbapol 940 and Hydroxypropyl methylcellulose (HPMC) was incorporated with selected NAT-SLNs to form mucoadhesive gels. The prepared NAT-SLN gels were evaluated for drug content, mucoadhesion force, release study, and in vitro microbiological activity. In vivo study for the chosen formulae was done to evaluate its efficacy against keratitis in rabbits.

Results: NAT-SLNs exhibited high EE % up to 99.167% and PS ranging from 128.35 to 1719.5 nm, with negatively charged ZP that confirmed the stability of SLNs. The NAT-SLN gels provided the high mucoadhesive force with a controlled release manner compared with the marketed-product MP. The in vivo experimental studies and histopathological examination showed the superiority of G2 (NAT-SLN (5% Pluronic F127 and 1:1 mixed lipid) 4% HPMC) over MP against Candida keratitis.

Conclusion: According to the obtained results, G2 provided an effective pharmaceutical system against fungal keratitis in a controlled release manner compared with MP for reducing dosage frequency.
PROSPECT OF STEM CELL THERAPY TO AVOID CYTOKINE STORM IN SEVERE COVID-19
Authors: PAWITAN J. A.
Published: September 2020

Severe COVID-19 cases are mostly due to severe inflammatory reaction and cytokine storm, which may lead to multiple organ failure and death. Until recently, there is no proven effective treatment for severe COVID-19. Mesenchymal stem cells (MSCs) have anti-inflammatory and regenerative properties. Therefore, they are supposed to work on COVID-19, which has failed to recover using other treatments. Therefore, studies are needed to determine the best tissue source of MSCs, the dose, repeat, and route of administration. For this review, we searched various databases, i.e. Pubmed, Science Direct, Springer, and WHO website using keywords: “mesenchymal stem cells” and “COVID-19” at 7 May 2020, without time limits. Various clinical trials on the use of MSCs for COVID-19 were registered, and initial results were reported. Initial results were promising but should be interpreted cautiously, as one was a case report, another one was case series, and one was a preliminary study of seven treated patients compared to three controls, where the baseline conditions were unequal. Therefore, well design randomized clinical trials are needed to get more robust prove.
Desinformación y crisis sanitaria: alcances y oportunidades para las bibliotecas
Authors: Hernández Jonathan
Published: September 2020

El objetivo del presente trabajo es presentar un panorama general de la desinformación en internet ocasionada por la crisis de salud de la covid-19, la enfermedad infecciosa causada por el coronavirus descubierto en diciembre de 2019. Se resalta la importancia de la información veraz en tiempo de crisis y se exponen algunos ejemplos que el sector bibliotecario ha desarrollado para mitigar los alcances de la desinformación.
Bibliotecas frente a la pandemia COVID-19: fundamentos y acciones en latinoamérica
Authors: Quitral Q. Yerko Andrés
Published: September 2020

La pandemia asociada a COVID-19 ha generado grandes cambios a nivel mundial, replanteando metodologías de trabajo y convivencia, debido fundamentalmente al distanciamiento social y al uso de métodos de bioseguridad. El actual panorama de respuesta de las instituciones patrimoniales y culturales latinoamericanas, tales como bibliotecas, archivos y museos frente a la COVID-19 es malo, debido a que en la práctica no presentan (desde antes a la pandemia) espacios adecuados para realizar procedimientos de aislamiento o cuarentena para sus objetos. Además, en un gran porcentaje, tampoco cuentan con implementos de bioseguridad básicos y procedimientos técnicos actualizados.Las instituciones que albergan bienes patrimoniales, históricos o culturales y que desarrollen trabajos de investigación, exposición o préstamos, deben asegurar la entrega de dicha información como un bien cultural necesario para la sociedad, integrando planes de bioseguridad, tanto para la salud de los trabajadores como para la conservación del patrimonio.
El devenir de la medicina mexicana a través del archivo histórico de la Facultad de Medicina de la UNAM
Authors: Martínez Barbosa María Xóchitl , Zacarías Prieto Jorge
Published: September 2020

El Archivo Histórico de la Facultad de Medicina de la Universidad Nacional Autónoma de México (UNAM), instituido a mediados del siglo XX, salvaguarda la memoria de la Escuela de Medicina de México, conocida primero como Establecimiento de Ciencias Médicas, hasta la Facultad de Medicina actual. La mayor riqueza documental de este archivo corresponde al siglo xix, pero con el paso del tiempo el acervo se ha ido enriqueciendo a través de donaciones de instituciones y particulares, así como de transferencias documentales de información producida en el siglo XX.El acervo conserva documentos que ofrecen una variedad de posibilidades para su investigación, sobre todo tomando en cuenta el creciente interés hacia la investigación por la historia de la salud y de la medicina en México, con estudios renovados que aportan nuevas visiones del devenir de las prácticas sanadoras, de la educación médica, de las instituciones de atención y asistencia médicas, entre otros temas viables para estudiar.
Biblioteca virtual SciELO: Acceso e indexación abiertos para las revistas académicas. Balance de 15 años de la colección SciELO-México
Authors: Sánchez Pereyra Antonio
Published: September 2020

Este trabajo tiene los siguientes objetivos: 1) retomar los antecedentes y productos de información que precedieron al sistema scielo para encontrar las líneas de continuidad así como las aportaciones específicas de este sistema, destacando su carácter pionero a nivel mundial como proyecto de acceso abierto y a nivel regional por la implementación de una metodología de publicación basada en metadatos e interoperables, así como por la creación del primer índice de citación en la región; 2) describir las características propias del desarrollo de la colección SciELO-México, haciendo énfasis en las fuentes de financiamiento que han hecho posible la sustentabilidad de una iniciativa de acceso abierto de este tipo; 3) realizar un balance de los logros así como de las limitaciones y agendas pendientes.
Coronavirus: se busca una vacuna
Authors: Cristina Rosas María
Published: September 2020

Frente a la pandemia provocada por el COVID-19, la comunidad internacional se ha volcado en la búsqueda de una vacuna. Sin embargo, en la historia de la humanidad queda de manifiesto que es difícil producir una vacuna en corto tiempo –normalmente el proceso toma de 10 a 20 años–, sobre todo por la necesidad de garantizar que sea inocua y segura. Actualmente existen vacunas solamente contra 26 enfermedades. La única enfermedad erradicada al día de hoy, gracias a la vacunación, es la viruela. Incluso si se lograra en corto tiempo tener una vacuna contra el covid-19 hay obstáculos que dicho antídoto enfrentará, entre otros los políticos, el movimiento antivacunas, el acceso para todos quienes la necesiten, etcétera. El camino se antoja difícil, sobre todo porque se corre el riesgo, como pasó con el terrorismo tras el 11 de septiembre de 2001, de sobredimensionar a las enfermedades de cara al nuevo coronavirus, dejando de lado una agenda integral, amplia y que mire al bosque, no sólo al árbol.
Los estudios de género en la UNAM: La biblioteca Rosario Castellanos del CIEG, UNAM
Authors: González Ordaz Cintia Elizabeth , Jiménez Escobar Alba , Franco Escobar Óscar
Published: September 2020

Este texto expone el proceso formativo de la Biblioteca “Rosario Castellanos”. Señala la importancia de elementos como los vínculos sociales del feminismo en México, el interés académico por los temas de género, y su impulso institucional en la unam. Entre dichos elementos identificamos como objeto central el resguardo de un acervo especializado (a través de distintas prácticas y disciplinas) a la manera de un bajo continuo de los proyectos académicos del Centro de Estudios de la Mujer, el Programa Universitario de Estudios de Género y el Centro de Investigaciones y Estudios de Género. Por último, se anuncian los proyectos actuales de la BRC (Biblioteca “Rosario Castellanos”), sus servicios, catálogos, archivos y bases de datos.
Why group size makes a difference for leader–member exchange quality
Authors: Li Hu , Huang Shiqi , Liu Li
Published: September 2020

Previous studies have shown the positive effect of high-quality leader–member exchange (LMX) on members' task performance, but further research is needed to establish if this effect varies according to boundary conditions. In this study we examined the effect of group size on
the LMX process by constructing a framework integrating social exchange and social comparison theories. We predicted that decreasing group size would enhance the relationship between LMX and members' task performance. Specifically, we anticipated that the positive relationship between LMX
and task performance would be strongest for members working in small groups with high LMX differentiation. By analyzing data collected from 368 supervisor–subordinate dyads employed at 39 bank branches in southeast China, we found that the positive relationship between LMX and task performance
was stronger for employees working in smaller groups than for those working in large groups. However, the three-way interaction term was not significant. The findings enhance understanding of the role played by group structure factors in the process of how LMX influences members' task performance.
Investigating Learner Silent and Verbal Responses to Tasks
Authors: Bao Dat , Ye Yongde
Published: September 2020

This article reports a study on EFL/ESL learner perceptions of classroom tasks with reference to verbal or non-verbal participation, that is, how much speech and silence would be employed in response to a rage of task types. Data were collected from 260 learners from Indonesia and the Philippines. The article begins by explaining why silence and speech are the focus of the discussion. Secondly, it shares the literature review on how silence works in language learning and why it deserves a place in classroom teaching. Thirdly, it highlights classroom tasks that trigger silent processing and explain why this is the case. Finally, there are recommendations for task design in which similar activity types are introduced to assist the learning of reflective students.
Falencias en derechos humanos en tiempos de pandemia del Coronavirus
Authors: Sánchez Marlenne , Sánchez Walter
Published: September 2020

En la incertidumbre de estar viviendo en tiempos de pandemia del COVID-19, nos preguntamos sobre qué está pasando en realidad, respecto a los derechos humanos en el discurso y en su aplicación por el Estado. Qué otra lectura podemos darle. Este ensayo tiene como objetivo motivar infinidad de interrogantes y deslizar distintas aristas de investigación científica vinculadas con la aparición mundial de la pandemia por SARS-CoV-2, desde la perspectiva de la vigencia y respeto de los derechos humanos, algunas de cuyas falencias han quedado expuestas principalmente en el Perú. Tras una contextualización inicial del tema, describimos la situación mundial en general y de nuestro país en particular, relacionada con la aparición y expansión de la enfermedad infecciosa llamada COVID-19; en cuyo examen y realidad se advierten insolvencias en la vigencia y observancia de algunos derechos humanos. Éstos se derivan de problemas de estructura social y económica del país, que ahora se agudizan dentro de la situación inédita a la que nos ha llevado el COVID-19. La desigualdad de oportunidades, la informalidad, la pobreza y la migración entre otras condiciones, repercuten en la salud y la vida del más vulnerable y necesitado en nuestro país.
Modelamiento matemático de la mortalidad por COVID-19 en China
Authors: Marín Machuca Olegario , Vargas Ayala Jessica Blanca , Marín Sánchez Ulert , Alvarado Zambrano Fredy Anibal , Lon Kan Prado Elena Elizabeth , Marín Sánchez Obert
Published: September 2020

Se ha desarrollado un modelo matemático que permita analizar el comportamiento de la mortalidad en la República Popular de China ocasionado por COVID-2019. Se aplicó el modelo logístico para los datos reportados entre 11 de enero y el 12 de abril del 2020. El modelo formulado fue linealizado y planteado en dos formas. La primera, evaluando el factor de corrección B, que hace las veces de cantidad máxima de fallecidos. Se determinaron los parámetros A, k y r, obteniendo el modelo (Ecuación 7), con un coeficiente de correlación r=-0,9660 y el coeficiente de determinación r^2×100=93,31 %. La segunda forma, con el mismo valor de B, introduciendo un factor de corrección para la variable independiente, t, que hace las veces de “periodo”. Se determinaron los parámetros A, k y r, obteniendo el modelo (Ecuación 10), con un coeficiente de correlación r=-0,9668 y el coeficiente de determinación r^2×100=93,48 %; lo que demuestra buena estimación del modelo (Ecuación 7 y Ecuación 10). Asimismo, se evaluó la velocidad de mortalidad, derivando, ordinariamente los modelos (Ecuación 7 y Ecuación 10), obteniendo los modelos de velocidad (Ecuación 8 y Ecuación 11); concluyendo que la máxima velocidad de mortalidad fue de 118 personas por día el día 24 de febrero de 2020.
Estrategia nacional peruana contra la propagación de la pandemia del coronavirus (COVID-19)
Authors: Alvarado Karina , Alvarado Susan , Esenarro Doris , Rodríguez Ciro , Iannacone Jose , Alvariño Lorena , Vásquez Wilson
Published: September 2020

La presente investigación es el estudio del caso Perú sobre las estrategias implementadas por el gobierno peruano a partir de la detección del paciente cero con el objetivo de contener la propagación de la pandemia por el coronavirus COVID-19 decretada por la OMS. Se detalla el comportamiento de la evolución de la cantidad de infectados a partir del 6 marzo al 24 de abril 2020. El primer grupo de medidas se adoptaron a partir de la detección del paciente cero hasta la declaración por la OMS (Organización Mundial de la Salud) como pandemia, acompañado de la implementación de protocolos acoplados a nuestro sistema de salud y medidas tomadas por el gobierno peruano mediante Decreto Supremo 008-2020-SA declarando emergencia sanitaria a nivel nacional por un plazo de 90 días. Posteriormente se pasó a tomar una serie de medidas evaluadas desde el 12 al 26 de marzo y del 27 de marzo al 24 de abril 2020, fecha que finaliza el presente estudio, detallando las estrategias consideradas por el gobierno peruano contra la propagación del coronavirus COVID-19. Entre las principales acciones adoptadas por el gobierno peruano ante COVID-19 tenemos: (1) restricciones de movilización de personas; (2) suspensión de reuniones y eventos públicos y privados; (3) cierre de fronteras a nivel internacional y el traslado de personas a diferentes departamentos en territorio peruano; (4) suspensión de clases en instituciones educativas (educación básica, centro de educación técnicas productivas y universidades), y (5) facilidades e incentivos económicos asistenciales.
Hybrid Power System Design for Damping Electromechanical Modes of Oscillation in Grid Connected Machines
Authors: Ul Islam Syed Sanjar , kumar Santosh
Published: September 2020

Due to the natural intermittent nature of wind and solar PV, autonomous wind/PV systems for renewable energy typically require energy storage or other sources of production to form a hybrid system. in this paper objective of the designing of a grid dynamics controller equipped with IGBT based bridge structure for stabilizing various electrical parameters on the grid system while its renewable energy-based grid integration. And the controller has to be designed with modulation technique, for both voltage and current at particular frequency following stabilization which is both simple in implementation and operation. And the comparative analysis of techniques used has to be carried out with AI-based optimization algorithms for studying its effectiveness. The results of the THD % of voltage in the system having no controller was found to be 3.32 %.  in the system having adaptive neural PSO switching of grid dynamics controller, the distortion level came down to 1.96%. The hybrid system with solar wind energy was further integrated with the grid and was analyzed for the rotor angle stability in the two machines. It was concluded that out of the three controls for grid dynamics controller the artificial intelligence-based adaptive neural PSO switching was found to be best with maximum stability of machines.
Are women really more affected by vasovagal syncope than men?
Authors: Alboni Paolo , Messop Anny Carole , Lauri Alessandro , Furlan Raffaello
Published: September 2020

It is commonly reported that vasovagal syncope (VVS) is more frequent in women. Presently, this issue has never been investigated. The purpose of this review was to evaluate, through an extensive review of the literature, whether women are really more affected by VVS than men. The gender distribution was investigated in individuals with classical and nonclassical VVS. The database PubMed was searched using the terms ‘syncope’, ‘vasovagal syncope’, ‘neurally mediated syncope’ and ‘tilt testing’. Twelve studies dealing with classical and 75 with nonclassical VVS were eligible. In the individuals with classical (N = 1861) and nonclassical VVS (N = 9696), a trend towards a greater percentage of women emerged (P = 0.14 and 0.07, respectively). In the total population with VVS (N = 11 557), the percentage of women was significantly higher than that of men (58 versus 42%, P = 0.03). Most of the individuals were young or middle-aged. In 84% of the studies, the percentage of women was greater than that of men. A separate analysis was carried out in older VVS patients (≥60 years) and only two studies were eligible to be evaluated. Considering that almost all the studies were carried out in the western nations, where the number of men and women is almost superimposable until the age of 65 years and a bias by gender has never been reported in the management of VVS, these data strongly suggest that young and middle-aged women are more affected by VVS than their male counterparts. At present, data are too scant to draw a definitive conclusion in older VVS patients.
Clinical management of electrical storm: a current overview
Authors: Guarracini Fabrizio , Casella Michela , Muser Daniele , Barbato Gaetano , Notarstefano Pasquale , Sgarito Giuseppe , Marini Massimiliano , Grandinetti Giuseppe , Mariani Marco V. , Boriani Giuseppe , Ricci Renato P. , De Ponti Roberto , Lavalle Carlo
Published: September 2020

The number of patients affected by electrical storm has been continuously increasing in emergency departments. Patients are often affected by multiple comorbidities requiring multidisciplinary interventions to achieve a clinical stability. Careful reprogramming of cardiac devices, correction of electrolyte imbalance, knowledge of underlying heart disease and antiarrhythmic drugs in the acute phase play a crucial role. The aim of this review is to provide a comprehensive overview of pharmacological treatment, latest transcatheter ablation techniques and advanced management of patients with electrical storm.
Early intervention or watchful waiting for asymptomatic severe aortic valve stenosis: a systematic review and meta-analysis
Authors: Ullah Waqas , Gowda Smitha Narayana , Khan Muhammad Shayan , Sattar Yasar , Al-khadra Yasser , Rashid Muhammad , Mohamed Mohamed O. , Alkhouli Mohamad , Kapadia Samir , Bagur Rodrigo , Mamas Mamas A. , Fischman David L. , Alraies M. Chadi
Published: September 2020

Background

The management of patients with severe but asymptomatic aortic stenosis is challenging. Evidence on early aortic valve replacement (AVR) versus symptom-driven intervention in these patients is unknown.

Methods

Electronic databases were searched, articles comparing early-AVR with conservative management for severe aortic stenosis were identified. Pooled adjusted odds ratio (OR) was computed using a random-effect model to determine all-cause and cardiovascular mortality.

Results

A total of eight studies consisting of 2201 patients were identified. Early-AVR was associated with lower all-cause mortality [OR 0.24, 95% confidence interval (CI) 0.13–0.45, P ≤ 0.00001] and cardiovascular mortality (OR 0.21, 95% CI 0.06–0.70, P = 0.01) compared with conservative management. The number needed to treat to prevent 1 all-cause and cardiovascular mortality was 4 and 9, respectively. The odds of all-cause mortality in a selected patient population undergoing surgical AVR (SAVR) (OR 0.16, 95% CI 0.09–0.29, P ≤ 0.00001) and SAVR or transcatheter AVR (TAVR) (OR 0.53, 95% CI 0.35–0.81, P = 0.003) were significantly lower compared with patients who are managed conservatively. A subgroup sensitivity analysis based on severe aortic stenosis (OR 0.24, 95% CI 0.11–0.52, P = 0.0004) versus very severe aortic stenosis (OR 0.20, 95% CI 0.08–0.51, P = 0.0008) also mirrored the findings of overall results.

Conclusion

Patients with asymptomatic aortic valve stenosis have lower odds of all-cause and cardiovascular mortality when managed with early-AVR compared with conservative management. However, because of significant heterogeneity in the classification of asymptomatic patients, large scale studies are required.
Modeling drive wheels of hoisting machines with rubber cables
Authors: Perekutnev V. E. , Zotov V. V.
Published: September 2020

Upgrading of hoisting machines aims to improve their performance, to reduce risk of accidents, and to cut down operational and capital costs. One of the redesign solutions is replacement of steel cables by rubber cables. This novation can extend life of pulling members, decrease diameters of drive and guide wheels and, consequently, elements of the whole hoisting machines: rotor, reducing gear, motor. This engineering novation needs re-designing of hoisting machines; thus, the new design should be validated, in particular, strength characteristics of the machine members. This article considers a drive wheel of a hoisting machine with a pulling belt. In order to justify the potential range of design parameters with regard to safety factor, the numerical models of different-design drive wheels are developed and their operation with pulling belt (rubber cable) is simulated in the SolidWorks environment. The data on the stress state of the wheel elements are analyzed, the most loaded points are identified, and the maximal stresses on the sidewall surface and in the spokes of wheels of different designs are plotted.
Geological and geochemical signs and criteria of potential mineralization in the Tangaralakh intrusion
Authors: Miroshnikova L. K. , Mezentsev A. Yu. , Semenyakina N. V. , Kotel'nikova E. M.
Published: September 2020

The scope of the discussion embraces the problems connected with development and improvement of geological information processing methods and systems, as well as modeling of primary mineral deposits in exploration of side rock mass and deep horizons of the deposits under mining and in new areas with intent to discover potential copper-nickel sulphide mineralization. The target of the research is the geological and geochemical preconditions and signs of sulphide mineralization in the potentially ore-bearing Tangaralakh field adjacent to the deposits of the Talnakh ore-magmatic system. The integrated research is based on the conventional different-rank geological, geochemical, magmatic, structural, tectonic, lithological and stratigraphical preconditions and signs of sulphide copper-nickel platinum-bearing ore in the Norilsk Region. The geochemical search of ore objects in the Norilsk Region provided the best results in case of the geological and structural analysis of spatial interactions between geochemical abnormalities as the geochemical zonality is yet the chief factor in the mineralization prediction. This method of improvement of geological-geochemical information processing and modeling of mineral deposits was tested in geological-geochemical modeling of the Talnakh ore province bodies. From the research findings, the structural and tectonic conditions of localization of the potentially ore-bearing Tangaralakh intrusion were determined. The structural modeling of geochemical field of the mineralization revealed the types of geochemical associations marking different compositions of sulphide mineralization in disseminated ore in different sections of the Tangaralakh intrusion. It is found that the geochemical zonality coincides with the mineral zonality of the disseminated ore horizon formed at different stages of orogenesis. The similarity elements are found in the geological-geochemical models of the Tangaralakh potentially ore-bearing ore field and Talnakh ore field (ore-magmatic system).
Modeling propagation of laser-ultrasonic probing pulse in stratified medium by the method of ABCD matrices
Authors: Pashkin A. I. , Vinnikov V. A.
Published: September 2020

The modern methods of modeling acoustic wave travel in stratified media are reviewed, and the necessity of a new and faster technique is justified. The method of modeling elastic wave propagation based on signal conditioning using ABCD matrices and a Python soft ware is described. The theoretical framework and the mathematical algorithm of the presented method are discussed. The main calculations of the main physical and mathematical relations of the method implementation in the program are given. The model signal is correlated with the test signal obtained from a medium with pre-set parameters. The temporal shapes and spectra of the signal inside an optical-acoustic converter are presented for two cases. In the first case, the optical-acoustic converter has a free surface (boundary with air); in the second case, the optical-acoustic converter is pressed to a steel plate. Based on the obtained data, the applicability of the method to modeling acoustic signal propagation in flat and stratified medium is proved. The critical advantage of the proposed modeling approach is high calculating speed of the signal shape and spectrum at any point of the medium and at any assigned time.
Theoretical research of heat exchange between air flow and shaft lining subject to convective heat transfer
Authors: Semin M. A. , Levin L. Yu.
Published: September 2020

The heat and mass transfer in a mine shaft under construction is researched theoretically under temperature conditions in the shaft lining lower than the temperature of air flow fed in the shaft via a ventilation duct. The research was aimed to ensure stable airing of mine shafts in the period of construction before cutting a shaft-to-shaft connection with artificial freezing of surrounding rock mass. The multi-parametric numerical modeling of nonstationary aeroand thermo-dynamic parameters in a mine shafts was performed using 3D convective heat transfer model in ANSYS. It is found that convective heat can exert considerable influence on the heat and mass exchange in the air space of the shaft when the shaft lining temperature is lower than the temperature of air flow from the ventilation duct at the shaft bottom. Inside the shaft, the back convective flows appear and air circulates in convective cells, which increases air flow rate in the shaft. As a consequence, the heat transfer factor at the shaft lining-air interface is much higher than the calculated factor without regard to the convective heat. The influence of the temperature difference at the air and shaft lining interface and the shaft lining roughness on the average values of the heat transfer factor and heat flow at the shaft lining and air interface is investigated. The empirical formulas are proposed for calculating the heat transfer factor and specific heat flow at the shaft lining and air interface depending on the temperature difference, shaft diameter and roughness of walls of underground openings.
Treatment of water inflow from flooded underground mines
Authors: Kulikova A. A. , Stelmakhov A. A. , Bacheva T. A. , Tsymbal M. N.
Published: September 2020

The study focuses on the adverse effect exerted on the environment by temporary shutdown and closure of underground mines by means of flooding. Closure of underground mines only terminates the structural and technological transformation of geological rock mass while detrimental effect on the natural environment of underground mines remains and even becomes more severe sometimes. Some hazards are revealed, which initiate new phenomena and processes, and are mainly connected with flooding of underground mines. Such hazards are groundwater rise, flow of water from flooded mines to operating mines, ground surface deformation due to subsidence and entry of pollutants in underground aquifers and surface water bodies. In terms of a flooded mine in East Donbass, the method of catchment of water outlet from the flooded mine and dispersion to a man-made biological pond is described. The biological pond is split into zones. First, there is a shallow place with planting for activation of growth of iron bacteria; here, removal of iron ions from mine water takes place. Then, water flows to the pond for the further bio-oxidation and treatment of water up to the standard MAC. The article offers recommendations on making of the biological pond and a trench for water flow from mine. The required volumes and sizes of the biological pond, trench and activation zone for iron bacteria are calculated. Treated mine water, via a dam, will be fed to a water storage reservoir.
Improvement of subsoil use waste management
Authors: Ulanov A. Yu. , Bahmin V. I. , Korobova O. S.
Published: September 2020

The information available on the volume and resource potential of subsoil use waste accumulated in the territory of Russia is generalized. The majority of the subsoil use waste is the result of activities of now closed mines and processing plants. The expert evaluations of the resource potential of different-kind subsoil use waste are presented. It is emphasized that the level of geological studies of subsoil use waste is low, the factual information on such waste is incomplete, and it is necessary to initiate and compose a unified national cadastre of subsoil use waste. It is required to undertake large-scale geological studies of the accumulated subsoil use waste in order to evaluate their resource potential and environmental impact. The indicated problems preventing commercial-scale processing of subsoil use waste include contradictions of the effective legislation and taxation in the subsoil use waste management. The measures aimed to improve the national policy in the sphere of subsoil use waste management are proposed, including foundation of a special federal agency for subsoil use waste management and shaping of an integrated management system encompassing all life stages of such waste.
Formation of water chemistry in the Modonkul river under the action of mine drainage effluent
Authors: Khazheeva Z. I. , Sanzhanova S. S.
Published: September 2020

The Dzhida ore field in the Zakamensk district of Buryatia features high concentration of mineralization within a small area. The Dzhida deposit is composed of complex ore. The ore field contains commercial-value primary deposits: Pervomai stockwork of molybdenum, Kholtoson tungsten lode and Inkur stockwork of tungsten. The Modonkul river catchment basin lies inside the Dzhida ore field. A real threat to the town of Zakamensk is created by manmade sand-bulk (old) tailings and slurry dump. By now, the concentrated flow of natural and man-made sand enters the low terrace and floodplain of the Modonkul river in the form of a talus train. This study is focused on the influence of the mine drainage effluent and the Inkur tributary on the water chemistry in the Modonkul river. 80 water samples were taken from the surface layer 0-0.5 m thick at five stations. Physicochemical indices of water were measured at the water sampling points, and the water chemistry was analyzed in a laboratory. In the background conditions, cations and anions in the Modonkul water chemistry range in decreasing order as follows: Са2+ > Mg2+ > Na++К+ и HCO - > SO 2- > Cl-. In the zone of mixture of natural and mine process water, the chemistry changes: from hydrocarbonate to sulfate (anion), from calcium-magnesium to sodium-calcium (cation). Downstream the natural chemistry changes to the hydrocabonate-sulfate composition, with prevailing content of calcium in cations. Iron content of water lowers 3-4 times after influx of mine effluents, while the contents of Mn, Zn, Co and Cd grow and then decrease downstream.
Influence exerted by underground excavation shape and by effective stresses on the formation of a tensile strain zone at a depth greater than 1 km
Authors: Nguyen Van Min , Eremenko V. A. , Sukhorukova M. A. , Shermatova S. S.
Published: September 2020

The article presents the studies into the secondary stress field formed in surrounding rock mass around underground excavations of different cross-sections and the variants of principal stresses at a mining depth greater than 1 km. The stress-strain analysis of surrounding rock mass around development headings was performed in Map3D environment. The obtained results of the quantitative analysis are currently used in adjustment of the model over the whole period of heading and support of operating mine openings. The estimates of the assumed parameters of excavations, as well as the calculations of micro-strains in surrounding rock mass by three scenarios are given. During heading in the test area in granite, dense fracturing and formation of tensile strain zone proceeds from the boundary of e ≥ 350me and is used to determine rough distances from the roof ( H roof) and sidewalls ( H side) of an underground excavation to the 3 boundary e = 350me (probable rock fracture zone). The modeling has determined the structure of secondary stress and strain fields in the conditions of heading operations at great depths.
Optimized control over modes of hydraulic percussion cutting heads of mining machines
Authors: Smirnov Yu. M. , Kenzhin B. M. , Smakova N. S. , Zhurunova M. A.
Published: September 2020

The main cause of the disagreement between the actual and calculated output data of hydraulic percussion mining machines is the erroneous feed of manipulation signals by the control units. For the maximal fitting of the calculated and actual figures, the continuous method of control action using the third time derivative of the law of motion of the main function element is accepted, namely, the accuracy. The mathematical models of control using displacement, velocity and acceleration are developed. The service factors of mining machines are found. Based on the theory of control and the mathematical logic theory, the logical circuits of formation of manipulation signals in each phase of the working cycle are developed. The main elements are converters, integrators and accumulators ensuring decomposition of elements of the logical circuits and further generation of appropriate control action. It is found that the simplest way is to generate the control action for acceleration of the key function element. For the developed circuits, it is recommended to use general charts of the control action change, implementable for a certain design of hydraulic percussion cutting heads in certain operating conditions.
Editorial
Authors: Arboleda Franco Santiago Adolfo
Published: September 2020

Esta edición de la revista Praxis Educación y Pedagogía resulta ser un peldaño más que se sube, en el camino de consolidar una publicación que, desde el suroccidente colombiano, comparta con la comunidad educativa nacional e internacional, producción intelectual del campo de conocimientos de la Educación y la Pedagogía, haciendo su aporte desde lo pretendido en nuestra política editorial.