bluuebunny/crossref_metadata_2025 huggingface dataset:
Estrategias Didácticas que Fomenten el Cuidado y Conservación del Agua
Authors: Montilla Rangel Enma Rosa
Published: January 2018

La presente investigación tiene como objetivo fundamental desarrollar estrategias didácticas que fomenten el cuidado y conservación del agua en el CEIB Barinitas. Parroquia Barinitas, Municipio Bolívar del estado Barinas. La naturaleza de la investigación estuvo enmarcada bajo el paradigma cualitativo y el tipo de investigación es la investigación acción, bajo un diseño de campo con un apoyo descriptivo cumpliendo las cuatro (4) fases planteadas por Murcia (1994), (Diagnostico, Planificación, Ejecución y Evaluación). La técnica aplicada para recabar la información fue la entrevista y la observación participante. De la misma manera, se utilizó como instrumento un guion de entrevista. Asimismo, para dar respuestas a las preguntas formuladas en el guion de entrevista se tomaron como informantes claves a tres (3) docentes pertenecientes a la institución en estudio. Los criterios de calidad de la investigación se basaron en fiabilidad, credibilidad, sistematicidad, confianza, transferibilidad y la confirmabilidad del instrumento. Para llevar a cabo el análisis e interpretación de la información se realizó a través del proceso de triangulación de datos. Los resultados obtenidos arrojaron la necesidad de ejecutar un plan acción para el fomento, cuidado y preservación del agua en los niños y niñas del Centro de Educación Inicial Bolivariano, Barinitas. Como conclusión se evidencio la intensión de los docentes de participar en jornadas de capacitación para mejorar las estrategias didácticas que fomenten el cuidado y preservación del agua en los educandos. y se recomendó a los directivos y coordinadores pedagógicos llevar un seguimiento y control para que las estrategias sean incorporadas a las clases diarias.
Conservación del Ambiente Basado en la Construcción de Cercas Vivas
Authors: Veras Burgos Nancy Yuraima
Published: January 2018

La presente investigación reflexiona sobre la conservación del ambiente, considerando, la necesidad de preservar los recursos naturales de una manera cónsona con el desarrollo de la educación ambiental , en tal sentido plantea como meta fundamental desarrollar un plan para la conservación del ambiente basado en la construcción de cercas vivas  en la  escuela básica pablo María Alisa Barinas estado Barinas, para los aportes teóricos que sustentan la investigación se consultaron, diferentes autores y enfoque relativos a la conservación del medio ambiente. La misma se desarrollará dentro del paradigma cualitativo y centrado en una investigación acción participante, en relación al diseño es de campo, por cuanto la recolección de datos se realizó directamente de los sujetos investigados, en lo que respecta a los informantes, se tomaron, cuatros (04) sujetos objetos de estudio, en cuanto a la técnica de recolección de datos se utilizó la entrevista y la observación. Finalmente, los resultados formarán la propuesta de aplicación para contribuir en la construcción de las cercas vivas.
Planeación Transdisplinaria de Proyectos de Aprendizaje
Authors: Mora Belandria Luis Alberto
Published: January 2018

Los proyectos de aprendizaje posibilitan al docente reconocer sus experiencias, conocimientos, habilidades, fortalezas, debilidades, potencialidades para decidir qué y cómo enseñar; permiten la contextualización de componentes de las áreas del conocimiento con visión holística y sistémica, al tomar del entorno datos, acontecimientos, saberes que contribuyan a la formación humanista e integral de los educandos, al desarrollo de su conciencia social, al logro del perfil del nuevo ciudadano que aspira la sociedad. Éste en su proceso de gestión potenciará la reconstrucción del pensamiento para lograr la enseñanza. El estudio generó referentes teóricos de la planeación transdisciplinaria de los proyectos de aprendizaje; enmarcado en enfoque cualitativo, apoyado en el método documental, utilizando la validez y fiabilidad hermenéutica-dialéctica, con los procesos de investigación cualitativa: categorización, estructuración, contrastación y teorización. Se evidenció que los docentes en la planeación de los proyectos de aprendizaje muestran una actitud mecánica y rutinaria, lo cual no permite ver la relación sistémica del proceso de planificación, existe fragmentación, el docente no logra la transdisciplinariedad del currículo debido a su visión positivista de la realidad. Se tiene que dirigir una perspectiva docente con base a la reconstrucción epistemológica de su actuación con base a la transdisciplinariedad.
Impacto de la Educación Continua en Docentes de la UNAE Amazonia, Ecuador
Authors: Rodríguez Rensoli Madelin , García Felipe Wilfredo
Published: January 2018

El objetivo del presente trabajo es socializar los resultados investigativos logrados en la evaluación de actitudes, valores y estados emocionales en docentes que transitaron por el Programa de Educación Continua, desarrollado por la UNAE Amazonía. Se utilizaron las Tablas de Diferencial Semántico (TDS) para identificar los cambios positivos que iban ocurriendo en ellos durante la implementación de estrategias metodológicas innovadoras en la enseñanza y aprendizaje. Lograr un cambio positivo del docente para involucrarse en procesos de cambios en su práctica pedagógica implicó un acompañamiento permanente en la identificación de las problemáticas a las que se enfrentaban, así como, en el diseño e implementación de alternativas de solución acordes a las exigencias del nuevo currículo orientado por el Ministerio de Educación en el país.
Responsabilidad Social Empresarial en el Contexto de las Relaciones Laborales en las PYMES
Authors: Villegas González Yalenis del Valle
Published: January 2018

El presente artículo investigativo se desarrolló con la finalidad, de describir la Responsabilidad Social Empresarial en el contexto de las relaciones Laborales y su contexto para generar cambios actitudinales y transformaciones en las Pequeñas y Medianas Empresas (PYMES) que repercutan en la transformación de los procesos empresariales, para la producción y productividad, contribuyendo al bienestar social y al medio ambiente, repercutiendo en la calidad de vida individual. La presente investigación se justifica como una visión emergente de las nuevas realidades del contexto empresariales de las Pymes. Teóricamente permite relacionar las variables, responsabilidad social empresarial, relaciones laborales y Pymes, que servirán como referencia y apoyo a otras investigaciones relacionadas a la temática abordada. Metodológicamente se empleó el método hermenéutico, orientado con una metodología de tipo documental mediante la revisión de bibliografía disponible sobre el tema, con un diseño bibliográfico de carácter descriptivo apoyada con un paradigma cualitativo. La población sometida a objeto de estudio está conformada por entrevistas de seis empresarios de forma aleatoria, el análisis discursivo de las entrevistas por las fuentes documentales, provenientes de diversos medios como son: libros, revistas, tesis, internet, artículos. Los resultados obtenidos infieren que la transformación de las políticas de empresariales y la RSE en el contexto de las relaciones laborales y con el medio deben involucrar la práctica responsable y espontánea por parte de las empresas y no como una imposición del Estado, para lograr una visión holística y sistémica con respecto a la RSE, satisfaciendo las necesidades y demandas de su entorno.
True Grit? Making a Scientific Object and Pedagogical Tool
Authors: Kirchgasler Christopher
Published: January 2018

The educability of personal qualities has garnered attention for its potential to raise student achievement. This investigation asks how one such quality—grit—has become a commonsensical way to think about differences among students. As a history of the present, grit is approached as a cultural thesis that links individualism to narratives of American exceptionalism and historical progress. This thesis is embodied in contemporary school reforms to “get gritty” in order to close achievement gaps. A danger of these reforms is how pedagogies of grit generate classificatory regimes that divide people by the display of particular attitudes and behaviors. As grit travels globally, it decontextualizes social and economic inequalities and explains them as owing to the intrinsic qualities of people.
Intramedullary Nailing of Both Bone Forearm Fractures in Children by Rush Nails and Titanium Elastic Nails
Authors: Dwivedi Rajeev , Joshi Ruban , Byanjankar Subin , Panthi Sagar , Shrestha Rahul , Ale Som
Published: January 2018

INTRODUCTION: Forearm fractures are common upper limb injuries among children and usually treated nonoperatively. Failure of nonoperative treatment, open injuries and multiple fractures are the indications for surgery in paediatric both bone forearm fractures.  Intramedullary (IM) nailing is considered as minimally invasive procedure with excellent to fair outcomes but it is not free of complications. We reviewed the results and compared the outcomes of IM fixation by Rush nails with titanium elastic nails (TENs), to understand the risks and complications associated with this procedures. MATERIAL AND METHODS: We performed a retrospective review of all paediatric patients treated for diaphyseal forearm fractures from January 2011  to  December  2015.  Complications  were  classified  according  to  modified  Clavien-Dindo  complication classification system. Outcomes were graded depending upon complication grade along with range of motion of forearm. RESULTS: There was no statistically significant difference for mean time to fracture union between the Rush nailing (10.56 weeks ) group and TENs nailing group (9.85weeks) (P = 0.43). There was no statistically significant difference in outcomes between Rush nailing and TENs nailing group p=0.65. In Rush nailing group outcomes were excellent in 16 (64%), good in 7(28%), fair in 2( 8%) patients and no poor outcome were noted. In TENs nailing group outcomes were excellent in 11 (55%) , good in 6 (30%), fair in 3 (15%) patients and no poor outcomes were noted.  CONCLUSION: Fixation of pediatric forearm fractures by intramedullary Rush nails and titanium elastic nails (TENs) are minimally invasive procedures and results are excellent to fair with acceptable complication rates. Since Rush nails are easily available and affordable in developing countries like ours we can prefer Rush nails for intramedullary fixation of paediatric forearm fracture when indicated.   Journal of Universal College of Medical Sciences (2016) Vol.04 No.01 Issue 13, Page: 10-15
Multi Vehicle-Type Right Turning Gap-Acceptance and Capacity Analysis at Uncontrolled Urban Intersections
Authors: Abhigna Doddapaneni , Brahmankar Dipak P. , Ravishankar Kodavanti Venkata Raghavendra
Published: January 2018

Intersections are the critical zones where conflicting, merging and diverging movements influence the intersection capacity. Uncontrolled intersections in particular pose dangerous situations to vehicular traffic. During peak vehicular flow, the unpredictable crossing behavior of minor stream vehicles induces delay and reduces the capacity of the intersection. Capacity at uncontrolled intersections is typically measured either by gap acceptance method, empirical regression approaches and conflict technique. Gap acceptance is an important characteristic for analyzing uncontrolled intersections. The behavior of different vehicle types and gap of subject vehicle type from minor street taking right turn to merge with major traffic stream is analyzed using gap acceptance method. The objective of the current study is to analyze the effect of major stream vehicle type combinations on the minor stream vehicle gap-acceptance behavior and to determine the capacity of the minor stream taking into account the influence of the right turning vehicles. The capacity of minor stream calculated using Highway Capacity Manual (HCM) 2010, Luttenin’s model, and Tanner’s model are compared. It is observed that two wheelers are more aggressive than three wheelers for most of the major stream vehicular combinations observed in this study.
The Combined Magneto Hydrodynamic and Electric Field Effect on an Unsteady Maxwell Nanofluid Flow over a Stretching Surface under the Influence of Variable Heat and Thermal Radiation
Authors: Khan Hameed , Haneef Muhammad , Shah Zahir , Islam Saeed , Khan Waris , Muhammad Sher
Published: January 2018

The manuscript is a presentation of the combined effect of magnetic and electric field on unsteady flow of Maxwell nanofluid over a stretching surface with thermal radiations. The flow of Maxwell nanofluid is assumed to be in an unsteady state. The basic governing equations changed to a group of differential equations, using proper similarity variables. The obtained modeled equations are nonlinear and coupled. An optimal approach is used to acquire the solution of the modeled problem analytically. The effects of electric field, magnetic field and thermal radiations on Maxwell nanofluid are the main focus in this study. The impact of the Skin friction on velocity profile, Nusselt number on temperature profile and Sherwood number on concentration profile are studied numerically. The influential behavior of the unsteady parameter λ , magnetic parameter M , electric parameter E , radiation parameter R d , Maxwell parameter β , thermophoresis parameter N t , Prandtl number Pr , Schmidt number S c , space dependent coefficient A and temperature dependent coefficient B on the velocity f ( h ) , concentration ϕ ( η ) and temperature θ ( η ) are analyzed and studied. The consequences are drawn graphically to see the physical significance of the problem.
Effect of Meniscus Damping Ratio on Drop-on-Demand Electrohydrodynamic Jetting
Authors: Kim Samuel , Kang Heuiseok , Kang Kyungtae , Lee Sang , Cho Kwan , Hwang Jun
Published: January 2018

Drop-on-demand (DOD) electrohydrodynamic (EHD) jet printing uses a nozzle and pulsated electric fields to eject small ink droplets of functional material to the appointed spot of a substrate at the appointed time, which offers solutions of high resolution patterning for fabrication of printed electronics, bioengineering, and display. Because the EHD jet connects fine drops to yield a fine pattern, it is essential to realize high throughput by generating drops quickly and reliably. In this study, the characteristics of jetting frequency were experimentally investigated as a function of nozzle dimensions by measuring response of jetting frequency to pulsating frequency which is varying from 1 Hz to 2000 Hz. The results showed that, even when the nozzle diameter is the same, the other dimensions of the nozzle significantly change the response of jetting to high pulsating frequency. Using a linear damping model describing hydrodynamic motion of ink inside the nozzle, the different behavior of the jetting frequency was explained via the different damping ratio of the oscillating ink: contrary to an underdamped system, an overdamped system supports a jetting frequency higher than the natural frequency.
Non-Clinical Contribution to Clinical Trials during Lead Optimization Phase
Authors: Martínez Muñoz Lázara
Published: January 2018

This manuscript comments on guidelines related to requirements for clinical trials for new drugs and the importance of considering regulatory criteria in the planning phase, in order to enhance the utility of data generated in basic research. Suggestions are made for optimizing regulatory management to improve the likelihood of acceptance of pre-clinical data prior to Clinical Phase I trials (early clinical trials).
Multi-Model Projections of River Flood Risk in Europe under Global Warming
Authors: Alfieri Lorenzo , Dottori Francesco , Betts Richard , Salamon Peter , Feyen Luc
Published: January 2018

Knowledge on the costs of natural disasters under climate change is key information for planning adaptation and mitigation strategies of future climate policies. Impact models for large scale flood risk assessment have made leaps forward in the past few years, thanks to the increased availability of high resolution climate projections and of information on local exposure and vulnerability to river floods. Yet, state-of-the-art flood impact models rely on a number of input data and techniques that can substantially influence their results. This work compares estimates of river flood risk in Europe from three recent case studies, assuming global warming scenarios of 1.5, 2, and 3 degrees Celsius from pre-industrial levels. The assessment is based on comparing ensemble projections of expected damage and population affected at country level. Differences and common points between the three cases are shown, to point out main sources of uncertainty, strengths, and limitations. In addition, the multi-model comparison helps identify regions with the largest agreement on specific changes in flood risk. Results show that global warming is linked to substantial increase in flood risk over most countries in Central and Western Europe at all warming levels. In Eastern Europe, the average change in flood risk is smaller and the multi-model agreement is poorer.
Implementation and Validation of Semi-Implicit WENO Schemes Using OpenFOAM®
Authors: Martin Tobias , Shevchuk Ivan
Published: January 2018

In this article, the development of high-order semi-implicit interpolation schemes for convection terms on unstructured grids is presented. It is based on weighted essentially non-oscillatory (WENO) reconstructions which can be applied to the evaluation of any field in finite volumes using its known cell-averaged values. Here, the algorithm handles convex cells in arbitrary three-dimensional meshes. The implementation is parallelized using the Message Passing Interface. All schemes are embedded in the code structure of OpenFOAM® resulting in the access to a huge open-source community and the applicability to high-level programming. Several verification cases and applications of the scalar advection equation and the incompressible Navier-Stokes equations show the improved accuracy of the WENO approach due to a mapping of the stencil to a reference space without scaling effects. An efficiency analysis indicates an increased computational effort of high-order schemes in comparison to available high-resolution methods. However, the reconstruction time can be efficiently decreased when more processors are used.
Rare-Earth Tantalates and Niobates Single Crystals: Promising Scintillators and Laser Materials
Authors: Dou Renqin , Zhang Qingli , Gao Jinyun , Chen Yuanzhi , Ding Shoujun , Peng Fang , Liu Wenpeng , Sun Dunlu
Published: January 2018

Rare-earth tantalates, with high density and monoclinic structure, and niobates with monoclinic structure have been paid great attention as potential optical materials. In the last decade, we focused on the crystal growth technology of rare-earth tantalates and niobates and studied their luminescence and physical properties. A series of rare-earth tantalates and niobates crystals have been grown by the Czochralski method successfully. In this work, we summarize the research results on the crystal growth, scintillation, and laser properties of them, including the absorption and emission spectra, spectral parameters, energy levels structure, and so on. Most of the tantalates and niobates exhibit excellent luminescent properties, rich physical properties, and good chemical stability, indicating that they are potential outstanding scintillators and laser materials.
Throat Patch Variation in Tayra (Eira barbara) and the Potential for Individual Identification in the Field
Authors: Villafañe-Trujillo Álvaro , López-González Carlos , Kolowski Joseph
Published: January 2018

The importance of identifying individuals of a population has been extensively documented in several species of carnivores, including some species of mustelids. This information is used in many kinds of ecological studies including density estimation, behavioral ecology and analyses of animal movement patterns. The objective of the present study was to determine if individual variation in the throat patches of Tayra (Eira barbara) permits individual identification. We examined 275 specimens from museum collections to determine the morphological variation of the throat patch in Eira barbara specimens collected throughout its distribution. We found differences in the shape and size of the throat patches significant enough to allow discrimination of individuals that display a throat patch (88.0% of 252 complete specimens). The proposed identification criterion was applied to photographic records obtained from a wild population using camera traps in the Peruvian Amazon. From nineteen images (54.0% of all images) in which the throat patch was visible, nine different individuals were identified and two of these were recaptured on multiple occasions.
Environmental Sustainability and Energy-Efficient Supply Chain Management: A Review of Research Trends and Proposed Guidelines
Authors: Centobelli Piera , Cerchione Roberto , Esposito Emilio
Published: January 2018

This paper conducts a structured review on the topic of energy efficiency and environmental sustainability in the supply chain management context to define research trends on the topic and identify research gaps. The review is carried out using the largest databases of peer-reviewed literature (Scopus and Web of Science). A sample of 122 papers focusing on the topic of energy-efficient and sustainable supply chain management was selected and analyzed through descriptive and content analysis. The review highlights that despite there is a growing research trend on the topic, different research gaps remain to be covered. These gaps concern the factors influencing energy efficiency and environmental sustainability initiatives, the classification of energy efficiency and environmental sustainability initiatives, the impact of energy efficiency and environmental sustainability on supply chain performance, the customer perspective in sustainable and energy-efficient supply chain, and the different technologies supporting the energy efficiency and environmental sustainability initiatives. The research gaps and the research questions identified offer the opportunity to identify areas of investigation to design future research directions and propose guidelines in the field of supply chain management.
District Heating Expansion Potential with Low-Temperature and End-Use Heat Savings
Authors: Nielsen Steffen , Grundahl Lars
Published: January 2018

District heating has the potential to play a key role in the transition towards a renewable energy system. However, the development towards reduced heat demands threatens the feasibility of district heating. Despite this challenge, opportunity exists in the form of fourth generation district heating, which operates at lower temperatures and enables better renewable integration. This article investigates this challenge by examining the district heating potential within three scenarios: The first is a reference scenario with current heat demand and temperatures, the second includes heat demand savings and the third includes reduced grid temperatures in addition to heat savings. To examine the scenarios, two models are developed. The first is a heat atlas model, in which heat demands are mapped on an address level. The second model assesses district heating expansion potentials based on economic costs. The models are applied using an example case of The Northern Region of Denmark. The article concludes that the district heating potential is highest in the reference scenario. When heat savings are introduced, district heating expansions, in most cases, will not be feasible. Introducing low-temperature district heating modestly increases the feasible expansion potential. This general conclusion is highly dependent on the specific system examined.
Study on a Battery Thermal Management System Based on a Thermoelectric Effect
Authors: Zhang Chuan-Wei , Xu Ke-Jun , Li Lin-Yang , Yang Man-Zhi , Gao Huai-Bin , Chen Shang-Rui
Published: January 2018

As is known to all, a battery pack is significantly important for electric vehicles. However, its performance is easily affected by temperature. In order to address this problem, an enhanced battery thermal management system is proposed, which includes two parts: a modified cooling structure and a control unit. In this paper, more attention has been paid to the structure part. According to the heat generation mechanism of a battery and a thermoelectric chip, a simplified heat generation model for a single cell and a special cooling model were created in ANSYS 17.0. The effects of inlet velocity on the performance of different heat exchanger structures were studied. The results show that the U loop structure is more reasonable and the flow field distribution is the most uniform at the inlet velocity of 1.0 m/s. Then, on the basis of the above heat exchanger and the liquid flow velocity, the cooling effect of the improved battery temperature adjustment structure and the traditional liquid temperature regulating structure were analyzed. It can be seen that the liquid cooling structure combined with thermoelectric cooling demonstrates a better performance. With respect to the control system, the corresponding hardware and software were also developed. In general, the design process for this enhanced battery thermal management system can provide a wealth of guidelines for solving similar problems. The H commutation circuit, matrix switch circuit, temperature measurement circuit, and wireless communication modules were designed in the control system and the temperature control strategy was also developed.
Analytical Determination of Energy Release in a Coal Mass
Authors: Zhang Chengguo , Tahmasebinia Faham , Canbulat Ismet , Vardar Onur , Saydam Serkan
Published: January 2018

In underground mining, it is not currently feasible to forecast a coal burst incident. A coal burst usually includes suddenly abrupt energy release in line with the significant deformed shape in a coal mass as well as coal ejection. The major source of the released energy is the energy stored in the coal. The effect of geological characteristics in the coal on the possible released energy due to material and joint damping is classified as a current silent issue. Therefore, innovative research is needed to understand the influence of coal’s joint and cleat characters (directions and densities) on the possible energy release and/or dissipation. A simple and novel analytical solution is developed in this paper to calculate the amount of released energy due to varying joint density. A broad validation is conducted by comparing the outcomes of the developed analytical model with the results of a three-dimensional numerical simulation using the commercial discrete element package 3DEC. An appropriate agreement has been observed between the results from the numerical modelling and the suggested closed form solution. The paper derives a novel analytical solution to calculate the amount of released energy in coal with different joint densities.
Numerical Simulation of Fluid Flow through Fractal-Based Discrete Fractured Network
Authors: Wang Wendong , Su Yuliang , Yuan Bin , Wang Kai , Cao Xiaopeng
Published: January 2018

Abstract: In recent years, multi-stage hydraulic fracturing technologies have greatly facilitated the development of unconventional oil and gas resources. However, a quantitative description of the “complexity” of the fracture network created by the hydraulic fracturing is confronted with many unsolved challenges. Given the multiple scales and heterogeneity of the fracture system, this study proposes a “bifurcated fractal” model to quantitatively describe the distribution of induced hydraulic fracture networks. The construction theory is employed to generate hierarchical fracture patterns as a scaled numerical model. With the implementation of discrete fractal-fracture network modeling (DFFN), fluid flow characteristics in bifurcated fractal fracture networks are characterized. The effects of bifurcated fracture length, bifurcated tendency, and number of bifurcation stages are examined. A field example of the fractured horizontal well is introduced to calibrate the accuracy of the flow model. The proposed model can provide a more realistic representation of complex fracture networks around a fractured horizontal well, and offer the way to quantify the “complexity” of the fracture network in shale reservoirs. The simulation results indicate that the geometry of the bifurcated fractal fracture network model has a significant impact on production performance in the tight reservoir, and enhancing connectivity of each bifurcate fracture is the key to improve the stimulation performance. In practice, this work provides a novel and efficient workflow for complex fracture characterization and production prediction in naturally-fractured reservoirs of multi-stage fractured horizontal wells.
Application of H∞ Robust Control on a Scaled Offshore Oil and Gas De-Oiling Facility
Authors: Durdevic Petar , Yang Zhenyu
Published: January 2018

The offshore de-oiling process is a vital part of current oil recovery, as it separates the profitable oil from water and ensures that the discharged water contains as little of the polluting oil as possible. With the passage of time, there is an increase in the water fraction in reservoirs that adds to the strain put on these facilities, and thus larger quantities of oil are being discharged into the oceans, which has in many studies been linked to negative effects on marine life. In many cases, such installations are controlled using non-cooperative single objective controllers which are inefficient in handling fluctuating inflows or complicated operating conditions. This work introduces a model-based robust H

∞

control solution that handles the entire de-oiling system and improves the system’s robustness towards fluctuating flow thereby improving the oil recovery and reducing the environmental impacts of the discharge. The robust H

∞

control solution was compared to a benchmark Proportional-Integral-Derivative (PID) control solution and evaluated through simulation and experiments performed on a pilot plant. This study found that the robust H

∞

control solution greatly improved the performance of the de-oiling process.
Effects of the Dietary Tryptophan and Aspartate on the Immune Response of Meagre (Argyrosomus regius) after Stress
Authors: Gonzalez-Silvera Daniel , Herrera Marcelino , Giráldez Inmaculada , Esteban María
Published: January 2018

Stress is one of the main problems of farmed fish, where it has been seen to result in a variety of disorders and negative effects. It is considered very important to minimize such effects and one option is the use of dietary additives. In the present experiment, meagre (Argyrosomus regius) specimens were fed three different diets: a control diet consisting of a commercial feed, a tryptophan-supplemented diet and an aspartate-supplemented diet. For each diet, fish were divided into three subgroups: non-stressed (resting), exposed to crowding or air-exposed. Just before the stress, and one and six hours post-stress, serum samples were taken to study several immune parameters (protease, antiprotease, peroxidase and lysozyme) and the bactericidal activity against three fish-pathogenic bacteria (Vibrio angillarum, V. harveyi and Photobacterium damselae subsp. piscicida). The results demonstrated that feeding the animals with the supplemented diets modulates the seric immune parameters, particularly when animals were stressed by air exposure.
Renal Tubule Repair: Is Wnt/β-Catenin a Friend or Foe?
Authors: Gewin Leslie
Published: January 2018

Wnt/β-catenin signaling is extremely important for proper kidney development. This pathway is also upregulated in injured renal tubular epithelia, both in acute kidney injury and chronic kidney disease. The renal tubular epithelium is an important target of kidney injury, and its response (repair versus persistent injury) is critical for determining whether tubulointerstitial fibrosis, the hallmark of chronic kidney disease, develops. This review discusses how Wnt/β-catenin signaling in the injured tubular epithelia promotes either repair or fibrosis after kidney injury. There is data suggesting that epithelial Wnt/β-catenin signaling is beneficial in acute kidney injury and important in tubular progenitors responsible for epithelial repair. The role of Wnt/β-catenin signaling in chronically injured epithelia is less clear. There is convincing data that Wnt/β-catenin signaling in interstitial fibroblasts and pericytes contributes to the extracellular matrix accumulation that defines fibrosis. However, some recent studies question whether Wnt/β-catenin signaling in chronically injured epithelia actually promotes fibrosis or repair.
Visualization and Quantitative 3D Analysis of Intraocular Melanoma and Its Vascularization in a Hamster Eye
Authors: Leszczyński Bartosz , Śniegocka Martyna , Wróbel Andrzej , Pędrys Roman , Szczygieł Małgorzata , Romanowska-Dixon Bożena , Urbańska Krystyna , Elas Martyna
Published: January 2018

A tumor vasculature network undergoes intense growth and rebuilding during tumor growth. Traditionally, vascular networks are histologically examined using parameters such as vessel density determined from two-dimensional slices of the tumor. Two-dimensional probing of a complicated three-dimensional (3D) structure only provides partial information. Therefore, we propose the use of microcomputed tomography (micro-CT) imaging to analyze the evolution of a tumor vasculature in an experimental ocular tumor model. A Bomirski Hamster Melanoma was implanted in the anterior chamber of a hamster eye. Ultrasound (US) imaging of the same tumor was performed in vivo, and the vascular results obtained using the two methods were compared. Normal ocular tissues, a tumor, and a tumor vascular structure were revealed with high accuracy using micro-CT. The vessels that grew within the tumor were chaotic, leaky, and contained many convoluted micro-vessels and embolizations. They comprised 20–38% of the tumor mass. The blood flow in the larger functional vessels was in the range from 10 to 25 mm/s, as determined by in vivo Doppler US. The micro-CT imaging of the hamster eyeball enabled both qualitative and quantitative 3D analyses of the globe at a histological level. Although the presented images were obtained ex vivo, micro-CT noninvasive imaging is being developed intensively, and high-resolution in vivo imaging is feasible.
Current Perspectives of Telomerase Structure and Function in Eukaryotes with Emerging Views on Telomerase in Human Parasites
Authors: Dey Abhishek , Chakrabarti Kausik
Published: January 2018

Replicative capacity of a cell is strongly correlated with telomere length regulation. Aberrant lengthening or reduction in the length of telomeres can lead to health anomalies, such as cancer or premature aging. Telomerase is a master regulator for maintaining replicative potential in most eukaryotic cells. It does so by controlling telomere length at chromosome ends. Akin to cancer cells, most single-cell eukaryotic pathogens are highly proliferative and require persistent telomerase activity to maintain constant length of telomere and propagation within their host. Although telomerase is key to unlimited cellular proliferation in both cases, not much was known about the role of telomerase in human parasites (malaria, Trypanosoma, etc.) until recently. Since telomerase regulation is mediated via its own structural components, interactions with catalytic reverse transcriptase and several factors that can recruit and assemble telomerase to telomeres in a cell cycle-dependent manner, we compare and discuss here recent findings in telomerase biology in cancer, aging and parasitic diseases to give a broader perspective of telomerase function in human diseases.
The Prevalence of Helicobacter pylori in Estonian Bariatric Surgery Patients
Authors: Šebunova Natalja , Štšepetova Jelena , Sillakivi Toomas , Mändar Reet
Published: January 2018

Helicobacter pylori (Hp) is one of the most important human pathogens that can cause duodenal and gastric ulcers, gastritis and stomach cancer. Hp infection is considered to be a cause of limiting access to bariatric surgery. The aim of this study was to determine the prevalence of Hp in patients with obesity going into bariatric surgery and to reveal the relationship between Hp and clinical data. The study group was formed of 68 preoperative bariatric surgery patients (body mass index (BMI) 44.7 ± 4.8). Gastric biopsies (antrum and corpus) were used for histological and molecular (caqA and glmM genes) examinations. The PCR method revealed Hp infection in 64.7% of obese patients that is higher in comparison with histological analysis (55.9%). The prevalence of cagA and glmM genes in antrum mucosa was 45.6% and 47.0% while in the corpus it was 41.2% and 38.3%, respectively. The coincidence of both cagA and glmM virulence genes in the antrum and corpus mucosa was 33.8% and 22.1%, respectively. Either of the genes was found in 58.8% of antrum and 57.3% of corpus mucosa. Presence of caqA and glmM genes was in association with active and atrophic chronic gastritis. In conclusion, our study demonstrated that two thirds of morbidly obese patients undergoing bariatric surgery are infected with Hp and have a high prevalence of cagA and glmM virulence genes that points out the necessity for diagnostics and treatment of this infection before surgery.
Deciphering the Functional Composition of Fusogenic Liposomes
Authors: Kolašinac Rejhana , Kleusch Christian , Braun Tobias , Merkel Rudolf , Csiszár Agnes
Published: January 2018

Cationic liposomes are frequently used as carrier particles for nucleic acid delivery. The most popular formulation is the equimolar mixture of two components, a cationic lipid and a neutral phosphoethanolamine. Its uptake pathway has been described as endocytosis. The presence of an aromatic molecule as a third component strongly influences the cellular uptake process and results in complete membrane fusion instead of endocytosis. Here, we systematically varied all three components of this lipid mixture and determined how efficiently the resulting particles fused with the plasma membrane of living mammalian cells. Our results show that an aromatic molecule and a cationic lipid component with conical molecular shape are essential for efficient fusion induction. While a neutral lipid is not mandatory, it can be used to control fusion efficiency and, in the most extreme case, to revert the uptake mechanism back to endocytosis.
Regulation of Three Virulence Strategies of Mycobacterium tuberculosis: A Success Story
Authors: Zondervan Niels , Van Dam Jesse , Schaap Peter , Martins dos Santos Vitor , Suarez-Diez Maria
Published: January 2018

Tuberculosis remains one of the deadliest diseases. Emergence of drug-resistant and multidrug-resistant M. tuberculosis strains makes treating tuberculosis increasingly challenging. In order to develop novel intervention strategies, detailed understanding of the molecular mechanisms behind the success of this pathogen is required. Here, we review recent literature to provide a systems level overview of the molecular and cellular components involved in divalent metal homeostasis and their role in regulating the three main virulence strategies of M. tuberculosis: immune modulation, dormancy and phagosomal rupture. We provide a visual and modular overview of these components and their regulation. Our analysis identified a single regulatory cascade for these three virulence strategies that respond to limited availability of divalent metals in the phagosome.
Mechanical Properties of Stainless-Steel Structures Fabricated by Composite Extrusion Modelling
Authors: Lieberwirth Clemens , Sarhan Mohamed , Seitz Hermann
Published: January 2018

Composite Extrusion Modelling (CEM) is a new additive manufacturing process for metal that uses Metal Injection Moulding (MIM) materials. The MIM material is printed on a build plate using a moveable extruder. Subsequently, the printed greenparts are debinded and sintered in a two-step oven process. In contrast to beam-based additive processes, the microstructure of the part is not generated layer-wise by melting and solidifying small areas, but in a steady manner during sintering from the outside of the part to the inside, in order to create dense metal parts. In this study, various structures were printed and sintered in order to investigate the mechanical properties and dimensional properties of the resulting stainless-steel structures, and their dependence on the infill percentage. The measured density of the dense sintered parts is 7.47 g/cm3 and the sintering shrinkage is in the range from 14.6 to 16.8%. The compressive strength (σdm50) of the specimens varies in the range from 1220 to 2345 MPa dependent on the infill percentage. The measured density and the sintering shrinkage are very close to the values specified by the manufacturer of the MIM material.
The Application of Chemical Foaming Method in the Fabrication of Micro Glass Hemisphere Resonator
Authors: Xie Jianbing , Chen Lei , Xie Hui , Zhou Jinqiu , Liu Guangcheng
Published: January 2018

Many researchers have studied the miniaturization of the hemisphere resonator gyroscope for decades. The hemisphere resonator (HSR), as the core component, has a size that has been reduced to the submillimeter level. We developed a method of batch production of micro-hemisphere shell resonators based on a glass-blowing process to obtain larger hemisphere shells with a higher ratio of height to diameter (H/D), we introduced the chemical foaming process (CFP) and acquired an optimized hemisphere shell; the contrasted and improved H/D of the hemisphere shell are 0.61 and 0.80, respectively. Finally, we increased the volume of glass shell resonator by 51.48 times while decreasing the four-node wineglass resonant frequencies from 7.24 MHz to 0.98 MHz. The larger HSR with greater surface area is helpful for setting larger surrounding drive and sense capacitive electrodes, thereby enhancing the sensitivity of HSR to the rotation. This CFP method not only provides more convenience to control the shape of a hemisphere shell but also reduces non-negligible cost in the fabrication process. In addition, this method may inspire some other research fields, e.g., microfluidics, chemical analysis, and wafer level package (WLP).
Hemimorphite Flotation with 1-hydroxydodecylidene-1,1-diphosphonic acid and Its Mechanism
Authors: Tan Wen , Liu Guangyi , Qin Jingqin , Fan Hongli
Published: January 2018

1-hydroxydodecylidene-1,1-diphosphonic acid (HDDPA) was prepared and first applied in flotation of hemimorphite. HDDPA exhibited superior flotation performances for recovery of hemimorphite in comparison with lauric acid, and it also possessed good selectivity against quartz flotation under pH 7.0–11.0. Contact angle results revealed that HDDPA preferred to attach on hemimorphite rather than quartz and promoted the hydrophobicity of hemimorphite surfaces. In the presence of HDDPA anions, the zeta potential of hemimorphite particles shifted to more negative value even if hemimorphite was negatively charged, inferring a strong chemisorption of hemimorphite to HDDPA. The Fourier transform infrared (FTIR) recommended that HDDPA might anchor on hemimorphite surfaces through bonding the oxygen atoms of its P(=O)–O groups with surface Zn(II) atoms. X-ray photoelectron spectroscopy (XPS) gave additional evidence that the Zn(II)-HDDPA surface complexes were formed on hemimorphite.
A Facile Route toward the Increase of Oxygen Content in Nanosized Zeolite by Insertion of Cerium and Fluorinated Compounds
Authors: Komaty Sarah , Anfray Clément , Zaarour Moussa , Awala Hussein , Ruaux Valérie , Valable Samuel , Mintova Svetlana
Published: January 2018

Enriching oxygen content within nanosized zeolite X (as synthesized Na-X) by insertion of cerium (ion exchanged Ce-X) and functionalization with bromoperfluoro-n-octane (fluorinated F-X) is reported. The materials were fully characterized by powder X-ray diffraction (XRD), dynamic light scattering (DLS), zeta potential, thermogravimetric analysis (TGA), nitrogen adsorption, and nuclear magnetic resonance (19F NMR). The O2 adsorption in the zeolite samples at various concentrations (0 to 165 Torr) at −196 °C was studied by in situ FTIR. The modification of nanosized zeolites did not alter their colloidal stability, crystallinity, porosity, and particle size distribution. The inclusion of cerium and bromoperfluoro-n-octane considerably increase the oxygen capacity by 33% for samples Ce-X and F-X in comparison to the as-synthesized Na-X zeolite. Further, toxicity tests revealed that these materials are safe, which opens the door for their implementation in medical applications, where controlled delivery of oxygen is highly desirable.
Quercetin Suppresses CYR61-Mediated Multidrug Resistance in Human Gastric Adenocarcinoma AGS Cells
Authors: Hyun Ho , Moon Jeong , Cho Somi
Published: January 2018

Cysteine-rich angiogenic inducer 61 (CYR61) is an extracellular matrix-associated protein involved in survival, tumorigenesis, and drug resistance. Therefore, we examined the effects of flavones against CYR61-overexpressing human gastric adenocarcinoma AGS (AGS-cyr61) cells, which show remarkable resistance to 5-fluorouracil (5-FU), adriamycin (ADR), tamoxifen (TAM), paclitaxel (PAC), and docetaxel (DOC). Among the tested flavones, quercetin had the lowest 50% inhibitory concentration (IC50) and significantly reduced the viability of AGS-cyr61 cells compared with AGS cells. Quercetin: (1) reduced multidrug resistance-associated protein 1 and nuclear factor (NF)-kappa B p65 subunit levels; (2) reversed multidrug resistance (MDR); (3) inhibited colony formation and induced caspase-dependent apoptosis; and (4) suppressed migration and down-regulated epithelial–mesenchymal transition-related proteins in AGS-cyr61. Moreover, AGS-cyr61 cells treated with quercetin concentrations close to the IC50 and simultaneously treated with 5-FU or ADR in the sub-lethal range showed strong synergism between quercetin and these two drugs. These findings indicate that CYR61 is a potential regulator of drug resistance and that quercetin may be a novel agent for improving the efficacy of anticancer drugs in AGS-cyr61 cells.
Evaluation of the Validity and Reliability of the Chinese Healthy Eating Index
Authors: Yuan Ya-Qun , Li Fan , Wu Han , Wang Ying-Chuan , Chen Jing-Si , He Geng-Sheng , Li Shu-Guang , Chen Bo
Published: January 2018

The Chinese Healthy Eating Index (CHEI) is a measuring instrument of diet quality in accordance with the Dietary Guidelines for Chinese (DGC)-2016. The objective of the study was to evaluate the validity and reliability of the CHEI. Data from 12,473 adults from the China Health and Nutrition Survey (CHNS)-2011, including 3-day–24-h dietary recalls were used in this study. The CHEI was assessed by four exemplary menus developed by the DGC-2016, the general linear models, the independent t-test and the Mann–Whitney U-test, the Spearman’s correlation analysis, the principal components analysis (PCA), the Cronbach’s coefficient, and the Pearson correlation with nutrient intakes. A higher CHEI score was linked with lower exposure to known risk factors of Chinese diets. The CHEI scored nearly perfect for exemplary menus for adult men (99.8), adult women (99.7), and the healthy elderly (99.1), but not for young children (91.2). The CHEI was able to distinguish the difference in diet quality between smokers and non-smokers (P < 0.0001), people with higher and lower education levels (P < 0.0001), and people living in urban and rural areas (P < 0.0001). Low correlations with energy intake for the CHEI total and component scores (|r| < 0.34, P < 0.01) supported the index assessed diet quality independently of diet quantity. The PCA indicated that underlying multiple dimensions compose the CHEI, and Cronbach’s coefficient α was 0.22. Components of dairy, fruits and cooking oils had the greatest impact on the total score. People with a higher CHEI score had not only a higher absolute intake of nutrients (P < 0.001), but also a more nutrient-dense diet (P < 0.001). Our findings support the validity and reliability of the CHEI when using the 3-day–24-h recalls.