bluuebunny/crossref_metadata_2025 huggingface dataset:
Ginkgolide C Alleviates Myocardial Ischemia/Reperfusion-Induced Inflammatory Injury via Inhibition of CD40-NF-κB Pathway
Authors: Zhang Rui , Han Dan , Li Zhenyu , Shen Chengwu , Zhang Yahui , Li Jun , Yan Genquan , Li Shasha , Hu Bo , Li Jiangbing , Liu Ping
Published: February 2018

Increasing evidence shows that inflammation plays a vital role in the occurrence and development of ischemia/reperfusion (I/R). Suppression of excessive inflammation can ameliorate impaired cardiac function, which shows therapeutic potential for clinical treatment of myocardial ischemia/reperfusion (MI/R) diseases. In this study, we investigated whether Ginkgolide C (GC), a potent anti-inflammatory flavone, extenuated MI/R injury through inhibition of inflammation. In vivo, rats with the occlusion of the left anterior descending (LAD) coronary artery were applied to mimic MI/R injury. In vitro, primary cultured neonatal ventricular myocytes exposed to hypoxia/reoxygenation (H/R) were applied to further discuss the anti-H/R injury property of GC. The results revealed that GC significantly improved the symptoms of MI/R injury, as evidenced by reducing infarct size, preventing myofibrillar degeneration and reversing the mitochondria dysfunction. Moreover, histological analysis and Myeloperoxidase (MPO) activity measurement showed that GC remarkably suppressed Polymorphonuclears (PMNs) infiltration and ameliorated the histopathological damage. Furthermore, GC pretreatment was shown to improve H/R-induced ventricular myocytes viability and enhance tolerance of inflammatory insult, as evidenced by suppressing expression of CD40, translocation of NF-κB p65 subunit, phosphorylation of IκB-α, as well as the activity of IKK-β. In addition, downstream inflammatory cytokines modulated by NF-κB signaling were effectively down-regulated both in vivo and in vitro, as determined by immunohistochemistry and ELISA. In conclusion, these results indicate that GC possesses a beneficial effect against MI/R injury via inflammation inhibition that may involve suppression of CD40-NF-κB signal pathway and downstream inflammatory cytokines expression, which may offer an alternative medication for MI/R diseases.
From Thermal Inspection to Updating a Numerical Model of a Race Bicycle: Comparison with Structural Dynamics Approach
Authors: Steenackers Gunther , Peeters Jeroen , Verspeek Simon , Ribbens Bart
Published: February 2018

Carbon fiber bicycle frames are complex-shaped structures and are prone to delaminations and difficult to inspect. The use of finite element model updating is common in structural dynamics but not so common in active thermography inspection. However, there are many advantages to using thermography when inspecting bicycle frames. These include the fact that the inspection can be performed in situ, can cover large areas, and is a quantitative method. In this paper, a numerical model of a bicycle frame will be updated and optimized by the surface temperature distribution captured with pulsed thermography. These results will be compared and benchmarked against frequency response function (FRF) measurement data as a reference. The chosen temperature decay measurements to be used as reference data will be of key importance. The goal of this manuscript is to compare both measurement results and model predictabilities after performing finite element model updating with respect to accuracy and speed.
Synthesis of Aligned TiO2 Nanofibers Using Electrospinning
Authors: Kim Jae-Hun , Lee Jae-Hyoung , Kim Jin-Young , Kim Sang Sub
Published: February 2018

In this work, aligned TiO2 nanofibers (NFs) were synthesized using an electrospinning technique with a two-piece Al collector. The effects of processing parameters, including the calcination temperature, applied voltage, and needle-to-Al-collector distance, were studied. The final phase of TiO2 was determined using the calcination temperature; calcination at 500 °C resulted in the formation of anatase phase, whereas calcination at 600 °C resulted in the formation of rutile phase. In addition, with the increase of calcination temperature, the diameter of the synthesized NFs decreased owing to the sintering and coalescence of nanograins existing in individual NFs. A specially designed collector configuration resulted in the parallel alignment of TiO2 NFs. The needle-to-collector distance and applied voltages caused the change in diameter and alignment of NFs. The diameter had an inverse relation with the needle-to-collector distance, and an optimal value of applied voltage was required to achieve TiO2 NFs with the smallest diameter. Furthermore, with the increase of applied voltage, the morphology of TiO2 NFs changed from an aligned to a disordered state.
Innovative Hybrid Modeling of Wind Speed Prediction Involving Time-Series Models and Artificial Neural Networks
Authors: Do Nascimento Camelo Henrique , Sérgio Lucio Paulo , Verçosa Leal Junior João , Von Glehn dos Santos Daniel , Cesar Marques de Carvalho Paulo
Published: February 2018

This work proposes hybrid models combining time-series models (using linear functions) and artificial intelligence (using a nonlinear function) that can be used to provide monthly mean wind speed predictions for the Brazilian northeast region. These might be useful for wind power generation; for example, they could acquire important information on how the local wind potential can be usable for a possible wind power plant through understanding future wind speed values. To create the proposed hybrid models, it was necessary to set the wind speed variable as a dependent variable of exogenous variables (i.e., pressure, temperature, and precipitation). Thus, it was possible to consider the meteorological characteristics of the study regions. It is possible to verify the hybrid models’ efficiency in providing perfect adjustments to the observed data. This statement is based on the low values found in the error statistical analysis, i.e., an error of approximately 5.0% and a Nash–Sutcliffe coefficient near to 0.96. These results were certainly important in predicting the wind speed time-series, which was similar to the observed wind speed time-series profile. Great similarities of maximums and minimums between the series were evident and showed the capacity of the models to represent the seasonality characteristics.
Effects of Sterilization Cycles on PEEK for Medical Device Application
Authors: Kumar Amit , Yap Wai Teng , Foo Soo Leong , Lee Teck Kheng
Published: February 2018

The effects of the sterilization process have been studied on medical grade thermoplastic polyetheretherketone (PEEK). For a reusable medical device, material reliability is an important parameter to decide its lifetime, as it will be subjected to the continuous steam sterilization process. A spring nature, clip component was selected out of a newly designed medical device (patented) to perform this reliability study. This clip component was sterilized for a predetermined number of cycles (2, 4, 6, 8, 10, 20…100) at 121 °C for 30 min. A significant decrease of ~20% in the compression force of the spring was observed after 30 cycles, and a ~6% decrease in the lateral dimension of the clip was observed after 50 cycles. No further significant change in the compression force or dimension was observed for the subsequent sterilization cycles. Vickers hardness and differential scanning calorimetry (DSC) techniques were used to characterize the effects of sterilization. DSC results exhibited no significant change in the degree of cure and melting behavior of PEEK before and after the sterilization. Hardness measurement exhibited an increase of ~49% in hardness after just 20 cycles. When an unsterilized sample was heated for repetitive cycles without the presence of moisture (121 °C, 10 and 20 cycles), only ~7% of the maximum change in hardness was observed.
Targeting Leukemia Stem Cells in the Bone Marrow Niche
Authors: Tasian Sarah K. , Bornhäuser Martin , Rutella Sergio
Published: February 2018

The bone marrow (BM) niche encompasses multiple cells of mesenchymal and hematopoietic origin and represents a unique microenvironment that is poised to maintain hematopoietic stem cells. In addition to its role as a primary lymphoid organ through the support of lymphoid development, the BM hosts various mature lymphoid cell types, including naïve T cells, memory T cells and plasma cells, as well as mature myeloid elements such as monocyte/macrophages and neutrophils, all of which are crucially important to control leukemia initiation and progression. The BM niche provides an attractive milieu for tumor cell colonization given its ability to provide signals which accelerate tumor cell proliferation and facilitate tumor cell survival. Cancer stem cells (CSCs) share phenotypic and functional features with normal counterparts from the tissue of origin of the tumor and can self-renew, differentiate and initiate tumor formation. CSCs possess a distinct immunological profile compared with the bulk population of tumor cells and have evolved complex strategies to suppress immune responses through multiple mechanisms, including the release of soluble factors and the over-expression of molecules implicated in cancer immune evasion. This chapter discusses the latest advancements in understanding of the immunological BM niche and highlights current and future immunotherapeutic strategies to target leukemia CSCs and overcome therapeutic resistance in the clinic.
Respiratory-Gated Proton Beam Therapy for Hepatocellular Carcinoma Adjacent to the Gastrointestinal Tract without Fiducial Markers
Authors: Mizuhata Miu , Takamatsu Shigeyuki , Shibata Satoshi , Bou Sayuri , Sato Yoshitaka , Kawamura Mariko , Asahi Satoko , Tameshige Yuji , Maeda Yoshikazu , Sasaki Makoto , Kumano Tomoyasu , Kobayashi Satoshi , Yamamoto Kazutaka , Tamamura Hiroyasu , Gabata Toshifumi
Published: February 2018

The efficacy of proton beam therapy (PBT) for hepatocellular carcinoma (HCC) has been reported, but insertion of fiducial markers in the liver is usually required. We evaluated the efficacy and toxicity of respiratory-gated PBT without fiducial markers for HCC located within 2 cm of the gastrointestinal tract. From March 2011 to December 2015 at our institution, 40 patients were evaluated (median age, 72 years; range, 38–87 years). All patients underwent PBT at a dose of 60 to 80 cobalt gray equivalents (CGE) in 20 to 38 fractions. The median follow-up period was 19.9 months (range, 1.2–72.3 months). The median tumor size was 36.5 mm (range, 11–124 mm). Kaplan–Meier estimates of the 2-year overall survival, progression-free survival, and local tumor control rates were 76%, 60%, and 94%, respectively. One patient (2.5%) developed a grade 3 gastric ulcer and one (2.5%) developed grade 3 ascites retention; none of the remaining patients developed grade >3 toxicities (National Cancer Institute Common Terminology Criteria for Adverse Events ver. 4.0.). This study indicates that PBT without fiducial markers achieves good local control without severe treatment-related toxicity of the gastrointestinal tract for HCC located within 2 cm of the gastrointestinal tract.
A Year in the Life of a Public Park: Route-Making, Vigilance and Sampling Time Whilst Walking
Authors: Medford Wayne
Published: February 2018

This paper offers a systematic, experimental, walking methodology to facilitate an ethnography of a major urban public park undertaken in the north-east of England in 2009–10. Ethnography puts the body in-place, placing the senses within the streams of life to be observed through experience; walking is one means of so doing. Walking traditions have frequently been used to observe, record and analyse the minutiae of urban life, with recent qualitative methodologies seeking to use walking to underpin ethnographies. Walking must negotiate the specificity of place and time, with all walks taking place in a real-world of materially, spatially, complex, vital and rhythmic landscapes. My aim was to systematically capture some of these patterns. Ethnographies typically use sustained field-based immersion; yet, some research utilises sampling strategies to guide observational procedures. Combining these methodologies allowed me to develop a methodology with three objectives: to create a series of routes to be followed; routes which allowed me to both scan and closely observe distant, and proximate, surroundings; and to construct a diurnal, weekly “sampling” frame, which allowed me to “immerse” myself within the park’s life through repeatedly walking these routes, building up a picture of everyday life, whilst (hopefully) capturing unscheduled events.
The Use of Manual Vacuum Aspiration in the Treatment of Incomplete Abortions: A Descriptive Study from Three Public Hospitals in Malawi
Authors: Odland Maria Lisa , Membe-Gadama Gladys , Kafulafula Ursula , Jacobsen Geir W. , Kumwenda James , Darj Elisabeth
Published: February 2018

Malawi has a high maternal mortality rate, of which unsafe abortion is a major cause. About 140,000 induced abortions are estimated every year, despite there being a restrictive abortion law in place. This leads to complications, such as incomplete abortions, which need to be treated to avoid further harm. Although manual vacuum aspiration (MVA) is a safe and cheap method of evacuating the uterus, the most commonly used method in Malawi is curettage. Medical treatment is used sparingly in the country, and the Ministry of Health has been trying to increase the use of MVA. The aim of this study was to investigate the treatment of incomplete abortions in three public hospitals in Southern Malawi during a three-year period. All medical files from the female/gynecological wards from 2013 to 2015 were reviewed. In total, information on obstetric history, demographics, and treatment were collected from 7270 women who had been treated for incomplete abortions. The overall use of MVA at the three hospitals during the study period was 11.4% (95% CI, 10.7–12.1). However, there was a major increase in MVA application at one District Hospital. Why there was only one successful hospital in this study is unclear, but may be due to more training and dedicated leadership at this particular hospital. Either way, the use of MVA in the treatment of incomplete abortions continues to be low in Malawi, despite recommendations from the World Health Organization (WHO) and the Malawi Ministry of Health.
The Interrelationship between Family Violence, Adolescent Violence, and Adolescent Violent Victimization: An Application and Extension of the Cultural Spillover Theory in China
Authors: Xia Yiwei , Li Spencer , Liu Tzu-Hsuan
Published: February 2018

The current study is the first study to emphasize family systems, violent norms, and violent peer association as three domains of the social environment that influence both adolescent violent offending and victimization among Chinese adolescents using a longitudinal sample. Under the framework of cultural spillover theory, the purpose of the current study was to explore how these three factors influenced adolescent violent offending and victimization. A total of 1192 middle and high school students were randomly selected from one of the largest cities in Southwest China. Structural equation model analysis was applied to investigate the direct and indirect effect of violence in the family system on violent offending and victimization. The results indicated that violent offending and victimization overlapped among Chinese adolescents. Violent peer association and acceptance of the violence norm fully mediated the effect of violence in the family system on violent offending, and partially mediated the effect of violence in the family system on violent victimization. In conclusion, adolescents who had experienced violence in their family system were more likely to be exposed to violent peer influences and to accept violent norms, which increased the likelihood of violence perpetration and victimization later in their life.
A Metabolomic Approach to Predict Breast Cancer Behavior and Chemotherapy Response
Authors: Cardoso Marcella , Santos Juliana , Ribeiro Marcelo , Talarico Maria , Viana Lais , Derchain Sophie
Published: February 2018

Although the classification of breast carcinomas into molecular or immunohistochemical subtypes has contributed to a better categorization of women into different therapeutic regimens, breast cancer nevertheless still progresses or recurs in a remarkable number of patients. Identifying women who would benefit from chemotherapy could potentially increase treatment effectiveness, which has important implications for long-term survival. Metabolomic analyses of fluids and tissues from cancer patients improve our knowledge of the reprogramming of metabolic pathways involved in resistance to chemotherapy. This review evaluates how recent metabolomic approaches have contributed to understanding the relationship between breast cancer and the acquisition of resistance. We focus on the advantages and challenges of cancer treatment and the use of new strategies in clinical care, which helps us comprehend drug resistance and predict responses to treatment.
Resveratrol and Pterostilbene Exhibit Anticancer Properties Involving the Downregulation of HPV Oncoprotein E6 in Cervical Cancer Cells
Authors: Chatterjee Kaushiki , AlSharif Dina , Mazza Christina , Syar Palwasha , Al Sharif Mohamed , Fata Jimmie E.
Published: February 2018

Cervical cancer is one of the most common cancers in women living in developing countries. Due to a lack of affordable effective therapy, research into alternative anticancer compounds with low toxicity such as dietary polyphenols has continued. Our aim is to determine whether two structurally similar plant polyphenols, resveratrol and pterostilbene, exhibit anticancer and anti-HPV (Human papillomavirus) activity against cervical cancer cells. To determine anticancer activity, extensive in vitro analyses were performed. Anti-HPV activity, through measuring E6 protein levels, subsequent downstream p53 effects, and caspase-3 activation, were studied to understand a possible mechanism of action. Both polyphenols are effective agents in targeting cervical cancer cells, having low IC50 values in the µM range. They decrease clonogenic survival, reduce cell migration, arrest cells at the S-phase, and reduce the number of mitotic cells. These findings were significant, with pterostilbene often being more effective than resveratrol. Resveratrol and to a greater extent pterostilbene downregulates the HPV oncoprotein E6, induces caspase-3 activation, and upregulates p53 protein levels. Results point to a mechanism that may involve the downregulation of the HPV E6 oncoprotein, activation of apoptotic pathways, and re-establishment of functional p53 protein, with pterostilbene showing greater efficacy than resveratrol.
The Selected Method and Tools for Performance Measurement in the Green Supply Chain—Survey Analysis in Poland
Authors: Tundys Blanka , Wiśniewski Tomasz
Published: February 2018

The methods and tools for the performance measurement and evaluation of the green supply chain management are very important elements for the construction and function of this type of supply chain. The result is a presentation of the considerations underlying a very general model, which presents some selected tools, but no breakdown of individual industries. The considerations undertaken are important and have scientific added value as usually in practice, a very large number of tools are used to assess the supply chain, which are not always correlated or adapted to the specificity of the chain. It is worth pointing out which of the already used or completely new tools and methods will be most useful for assessing the green supply chain. The structure of the paper covers the theoretical and empirical. It includes an introduction, our goals and hypotheses, state of the art, methodology, empirical findings, and discussion. We present the definitional differences between green and sustainable supply chains and focus on the selection and identification of methods for the framework model for evaluating the green supply chain. In the next step, the theoretical and selected method and tools were compared to a survey of Poland. On the basis of the survey, we present the findings and discussions found in this area. The main methodology used includes a literature review, a survey analysis using a questionnaire and statistical tools. The survey was carried out in 2015 in sample organizations in Poland. The research results showed that organizations were aware of the environmental elements of measuring and assessing the supply chain from an environmental point of view, but their use depended on many factors: the area, size of the organization, or the industry. If certain boundary conditions are met and the organizations are aware of the essence of environmental aspects in the chain, then they are applying green measures to the supply chain. These findings provide a glimpse into the measurement system and show that organizations still have yet to understand the essence of green and sustainable performance measurement, the meaning of its application, and the benefits it brings. However, traditional measurement still plays a large role, so it is important to reflect on how to convince organizations to pay more attention to environmental aspects, while at the same time applying a green supply chain assessment model. These results are a framework in which to start building a green supply chain assessment model. The empirical research aimed to answer the question of whether theoretical and sustainable management tools have already played a role in perceiving and assessing the green supply chain.
In vitro analysis of colistin-carbapenem combination activity against Acinetobacter spp infection
Authors: Soudeiha Micheline , Sokhn Elie S , Daoud Ziad , Sarkis Dolla
Published: February 2018

Introduction: Increasing carbapenem resistance in Acinetobacter spp calls for the appraisal of alternative strategies in Acinetobacter spp infection therapy. This study aims at evaluating colistin-carbapenem combination against Acinetobacter spp using the checkerboard, Etest, and time-kill methods.

Methodology: One hundred nonrepetitive Acinetobacter spp isolates were collected from patients admitted at the Saint-George-Hospital-University-Medical-Center over a one year period. The identification was performed using the API20NE and confirmed by the amplification of the blaOXA-51-like. Susceptibility to colistin, and carbapenems were determined using the Etest, microdilution methods and interpreted according to the CLSI, 2015. Detection of the carbapenemases was performed by PCR amplification method. Clonality was determined by the 3-Locus PCR-typing and ERIC-PCR methods. The synergistic potential of the combination was determined by calculating the Fractional-Inhibitory-Concentration-Index, which determines a synergistic, additive, indifferent or antagonistic effect.

Results: In our study (84%) of the isolates were carbapenem resistant. Only one strain showed resistance to colistin. (99%) and (77%) of the Acinetobacter spp isolates harbored blaOXA-51-like and blaOXA-23-like respectively. (86.2%) of the A.baumannii isolates pertained to the International Clone II. An additive effect of the colistin-carbapenem combination was determined using the 3 methods. A decrease of 2.6 and 2.8 folds in the MIC of colistin was showed in colistin-meropenem and colistin-imipenem, respectively (p < 0.001). The Colistin-meropenem showed better effects when compared to colistin-imipenem (p < 0.05). Only a few isolates showed a synergistic effect in the time-kill assay.

Conclusion: Our study showed that the decrease in the MIC of colistin following colistin-carbapenem combination might be a promising antimicrobial approach for treating carbapenem-resistant Acinetobacter spp.
Increase of blaOXA-23-like in Acinetobacter baumannii at a tertiary care center in Lebanon between 2007 and 2013
Authors: Kanj Souha S , Tayyar Ralph , Shehab Marwa , El-Hafi Bassam , Rasheed Sari S , Kissoyan Kohar Annie , Kanafani Zeina A , Hanna Wakim Rima , Kara Zahreddine Nada , Araj George F , Dbaibo Ghassan , Matar Ghassan M
Published: February 2018

Introduction: The multi-drug resistant nature of Acinetobacter baumannii isolates have rendered many broad-spectrum antimicrobial agents ineffective against them. The purpose of this retrospective study is to define and compare the molecular characteristics of A. baumannii isolates from patients at a tertiary care center in Lebanon from two outbreaks, the first in 2007-2008, as part of a case-controlled study involving A. baumannii cases admitted to the ICU, and the second in 2013.
Methodology: A total of 148 A. baumannii clinical isolates were collected from various clinical specimens during 2007-2008 and 2013. All A. baumannii isolates were screened for blaOXA-23-like and blaOXA-51-like genes of carbapenem resistance. Additionally, in an effort to assess the degree of the isolates’ genomic relatedness, random amplification of polymorphic DNA (RAPD) was performed.
Results: There was an increase in the prevalence of blaOXA-23-like and blaOXA-51-like genes between the two time periods; however, only 22% isolate genomic relatedness was calculated between 2007-2008 and 2013. Taking 80% as a margin of compatibility, 31 distinct clusters containing 2 to 11 strains were observed when both time periods were analyzed.
Conclusion: The presence of numerous clusters accompanied by a predominant increase in the prevalence of blaOXA-23-like between 2007 and 2013 suggests a horizontal transmission of the gene within various strains of the species, contributing to the persistent increase in carbapenem resistance over the years. Therefore, infection control measures are required with compliance among all healthcare workers.
Integrated assessment of urban green infrastructure condition in Karlovo urban area by in-situ observations and remote sensing
Authors: Dimitrov Stelian , Georgiev Georgi , Georgieva Margarita , Gluschkova Maria , Chepisheva Ventsislava , Mirchev Plamen , Zhiyanski Miglena
Published: February 2018

The knowledge about urban green infrastructure (UGI) is important for maintaining the quality of life in cities, suburbs and the fringes of metropolitan areas. The perspective of rapid urban sprawl generates the need for establishment and use of adequate systems for monitoring the condition of the urban ecosystems and green spaces. This triggers the search for a stronger link between the condition of urban green infrastructure and its capacity to supply ecosystem services (ES). In this paper are presented the results of the assessment of the health status of tree and shrub vegetation in UGI of Karlovo through an integrated application of in-situ observation and remote sensing using Unmanned Aerial Vehicle (UAV) technology. The study showed that the implementation of this flexible approach provides rapid and low-cost results, with good quality of the generated information. This makes the approach appropriate as a basis for monitoring of green systems in urbanised areas, with subsequent detailed investigation of solitary trees for cataclysms and epiphytotics of native species and rapid detection for the population of invasive insect and pathogen’s in order to prevent their distribution in new areas.
Assessment and mapping the dynamics of soil properties in selected forest stands from the region of Central Balkan National Park in the context of ecosystem services
Authors: Yaneva Rositsa , Zhiyanski Miglena , Markoff Ivailo , Sokolovska Maria , Nedkov Stoyan
Published: February 2018

Forests set natural conditions and embody a repository of biological diversity that represents a myriad of ecosystem services for human well-being. The spatial patterns and the forest ecosystems’ dynamics over time make the forests of particular environmental significance for the provision of ecosystem services. The terrestrial biodiversity and the sustainable management strategies' demand for mapping and assessment of the dynamics for the condition of forest ecosystems by drawing attention to the soil properties. In order to take on that task, the data series obtained by the International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests) for the period 1986–2016 were found as appropriate quantitative indicators that convey information about the ecosystem’s capacity to provide certain regulating ecosystem services. The ICP Forests Level I sites, located in the Central Balkan region, provide consistent information, which is collected on a regular basis about observed forest stands.

The primary focus of the present research is to conduct a biophysical assessment of the forest ecosystems and to define their overall condition regarding two time series – the periods 1992/1993 and 2015. This study attempts to introduce an innovative approach and aims at linking the existing ICP Forests network dataset with the ecosystem services concept and the identified spatial units from the CORINE Land Cover (CLC) polygons for the territory of Central Balkan National Park. On this basis and through the implementation of GIS techniques, the dynamics of soil properties in selected forest ecosystems was analysed with regard to their capacity to supply relevant ecosystems services, which were assessed and mapped. The biophysical data provides robust information on the ecosystem services and the results show the variations in the capacity of different forest sub-types to provide ecosystem services within a well-defined land cover unit. Additionally, the research work intended to review the generated outcomes with reference to the DPSIR (driver-pressure-state-impact-response) method by giving feedback on the changes in the terrestrial ecosystems in the last 25 years. Further application of the mapping approach in assisting the communication in the decision- making process is also discussed.
Relação entre a formação continuada e os recursos tecnológicos, na percepção de professores da educação superior
Authors: Ribeiro Alexandra Ferreira Martins , Vieira Alboni Marisa Dudeque Pianovski
Published: February 2018

O olhar deste estudo voltou-se às autobiografias dos professores das ‘licenciaturas de matemática’ das instituições de ensino superior de caráter privado em Curitiba. A pesquisa teve como objetivo geral investigar sua percepção acerca da relação entre a formação continuada e os recursos tecnológicos e desdobrou-se nos seguintes objetivos: analisar as percepções docentes acerca do uso dos recursos tecnológicos na formação continuada e examinar como os docentes compreendem sua aplicação na relação entre professor e aluno no processo de ensino e aprendizagem. A metodologia utilizada é de caráter bibliográfico com pesquisa de campo, contando com os estudos de Brito e Purificação (2011), Rasco e Recio (2013), Gimeno Sacristán (2013), Tardif (2014) e Kenski (2015). Na pesquisa de campo, utilizaram-se os procedimentos teórico-metodológicos da História Oral para a realização das sete entrevistas feitas com os docentes que atuavam nas ‘licenciaturas de matemática’ em Curitiba. Verificou-se que eles percebem as possibilidades e os desafios do uso dos recursos tecnológicos tanto na formação continuada, quanto na relação entre professor e aluno. Dentre as possibilidades, a formação continuada em tempos e espaços flexíveis; dentre os desafios, acompanhar a rapidez das inovações e sua aplicação em sala de aula.
Acesso e permanência na educação superior: estratégias de ingresso mobilizadas no ‘Colégio Militar de Campo Grande’
Authors: Maciel Carina Elisabeth , Assis Jacira Helena do Valle Pereira , Silva Miriam Ferreira de Abreu da
Published: February 2018

A trajetória de estudantes, em especial no que tange a acesso e permanência na educação superior, está intrinsecamente relacionada ao processo de escolarização, isto é, é determinada pela estruturação e ampliação do capital escolar na educação básica. Neste texto são discutidas as estratégias mobilizadas por uma escola pública de prestígio – como o Colégio Militar de Campo Grande –, que contribuem para o ingresso na educação superior. Busca-se compreender como os agentes e a instituição - colégio, famílias e estudantes - desenham um projeto que culmina em aprovações em cursos de nível superior no País e na região. As fontes utilizadas são relatórios oficiais do Sistema Colégio Militar do Brasil e o periódico do CMCG, dentre outros, - analisados com base em estudos bourdieusianos. Os resultados sinalizam que o Colégio Militar reúne elementos de ordem pedagógica e simbólica que geram ações e sentimentos de pertença em seus estudantes, que, uma vez mobilizados, produzem resultados positivos de acesso à educação superior.
Implicações do SiSU no processo de democratização do acesso à educação superior: o caso da Unemat
Authors: Lima Elizeth Gonzaga dos Santos , Malange Fernando Cezar Vieira , Borges Luiz Francisco
Published: February 2018

A política nacional de democratização do acesso à educação superior do MEC, instituída pelo Sistema de Seleção Unificada (SiSU), traz consigo mecanismos com propósitos de democratizar as vagas nos cursos superiores públicos. Em 2012, a Universidade do Estado de Mato Grosso (Unemat) aderiu ao SiSU; assim, em 2013, passa a ter duas principais formas de seleção (SiSU no primeiro semestre e vestibular no segundo semestre) de cada ano. Pesquisas realizadas afirmaram que o ingresso na Unemat já era democratizado. A questão que levantamos neste estudo é: com a adesão ao SiSU, o ingresso continuou democratizado? Assim, o objetivo da presente pesquisa é compreender a adesão ao SiSU no câmpus Universitário de Cáceres e sua relação com o processo de democratização da IES. Foi aqui adotada como tipo de pesquisa a abordagem quanti-qualitativa. O procedimento metodológico ocorreu em três etapas: análise documental; análise do banco de dados – Enem - e análise de dados do vestibular. Os instrumentos de pesquisa foram os questionários socioeconômicos do Enem e do vestibular/Unemat. Os resultados evidenciaram que houve várias mudanças na Unemat após a implementação do SiSU como forma de ingresso. Tais mudanças foram introduzidas no perfil acadêmico, nas políticas institucionais, na gestão administrativa e na gestão pedagógica.
Expansão e interiorização das universidades federais no período de 2003 a 2014: perspectivas governamentais em debate
Authors: Camargo Arlete Maria Monte de , Araújo Israel Martins
Published: February 2018

A redução da influência do setor público na educação superior brasileira ocorreu desde o final do século passado, motivada pela falta de investimentos nesse setor. Os governos Lula da Silva (2003-2006) (2007-2011) mantiveram o fomento ao segmento privado, direcionando investimentos ao setor público com a preocupação em criar novas universidades federais com a perspectiva de interiorizá-las, já que a sede da maioria dessas universidades estava concentrada nas capitais dos estados. Dilma Rousseff (2011-2014) orientou-se pela mesma linha de seu antecessor, procurando dar continuidade a abertura de universidades no interior do país. Neste trabalho analisou-se a constituição dessa política com foco na interiorização, integração e regionalização da educação superior, base do processo de criação dessas universidades, que ocorre contraditoriamente às restrições orçamentárias existentes. Além do levantamento bibliográfico sobre a temática, utilizou-se dados secundários referentes à taxa de escolarização de educação superior e os sítios das universidades pesquisadas. Apesar das contradições que acompanham essa política, há indícios de que a política contribuiu para a diminuição das assimetrias regionais existentes no país, o que não impede que outros critérios tenham sido igualmente considerados.
Políticas, Gestão e Direito a Educação Superior: Novos Modos de Regulação e Tendências em Construção
Authors: Mancebo Deise , Silva Júnior João Dos Reis , Oliveira João Ferreira de
Published: February 2018

O presente texto problematiza e busca analisar as tendências em construção em educação superior no Brasil na educação superior brasileira, bem como as mudanças e novas regulações que vêm ocorrendo depois de um período de clara expansão, considerando as políticas e ações projetadas para esse campo na conjuntura de crise que se desenha nos últimos anos. Ele sintetiza um estudo de caráter exploratório; sua construção apoia-se em pesquisa bibliográfica e análise documental de problemáticas convergentes e necessárias à compreensão do tema, mas também na consulta a estatísticas existentes, adotando, portanto, uma perspectiva de análise que conjuga aspectos quantitativos e qualitativos. Conclui apontando desafios e alternativas no campo dos movimentos sociais e políticos.
Effect on Structure and Properties of Cement-Based Materials by Polymer-Modified Metakaolin Slurry
Authors: Zhang Jun Hua , Yuan Kai , Shui Zhong He , Wang Yi Yu
Published: February 2018

It is not easy to disperse metakaolin in the cement concrete uniformly. The reunite phenomenon caused by lamellar structure and fine particles can reduce the properties of concrete. The fluidity of mortar were studied by recombining polyethylene glycol (PEG), sodium methyl-dinaphthalene sulfonate (NNO) and hydroxyethyl cellulose (HEC) with the metakaolin slurry, and then the internal structural properties of the different cement-based materials were analysed. The experimental results showed that when the ratio of MK and H2O was 35 : 65, the metakaolin slurry could reduce the adverse effect of metakaolin on the fluidity of mortar to a certain extent. The slurry prepared by P1N2H2, P2N1H2 and P2N1H1 composite dispersant dispersed more uniformly in the mortar than other groups. The hydration caused by these types of slurry during cement formation consumed Ca(OH)2 crystals sufficiently, which led to generating more dense C-S-H gel structure in the final cement-based materials.
Effect of Cold Rolling Reduction on Recrystallization Behaviors of AA5754 Sheets in a Short Annealing Time
Authors: Liu Zhen Shan , Zhao Pi Zhi , Zhao Jing Wei
Published: February 2018

With the development of light-weighting vehicles, AA5754 sheets are widely utilized as automotive structure material. Its strength and formability are greatly related to the recrystallization process. The recrystallization behavior of AA5754 sheets at high temperature in short time (in minutes) was rarely reported. In present work AA5754 sheets with cold rolling reduction from 58 to 75% was annealed in short time (max 6 min) at 310 and 320°C. Its recrystallization behavior was studied by means of microstructure observation and tensile testing. Microstructure shows that the incubation time varies in the range of 30-120 seconds with cold rolling reduction. The incubation time becomes shorter with the higher cold rolling reduction. According to the tensile strength, the recrystallization kinetics was expressed with JMAK equation. The JMAK equation fitted with recrystallization time gives a better agreement with experimental results than that fitted with annealing time. The calculated apparent activation energy for recrystallization decreases with the increasing cold rolling reduction, indicating that the recrystallization occurred much easier in AA5754 sheet with higher cold rolling reduction.
Segregation and Precipitation Behavior of Phosphorus in a Ni-Fe-Cr Base Wrought Superalloy
Authors: Zhang Sha , Zhang An Wen , Wang Wei Yang , Xin Xin , Zhang Kai
Published: February 2018

The segregation and precipitation behavior of phosphoruswas studied in aNi-Fe-Cr base wroughtsuperalloy. The precipitation behavior of phosphides in the alloy contained 0.025% Pwas examined after soaking at 750-1080°C to determine the precipitation temperature range of MNP-type phosphide. The microstructuresunder these various conditions wereinvestigated by scanning electron microscope(SEM) and energy dispersive spectroscopy (EDS). The precipitation temperature of the phosphide in the alloy was determined to be in the range of 850-1040 °C and the precipitation peak temperature was around 980°C.In addition, the melting temperatureof the phosphide was determined to be between 1200 °C and 1250 °C. The current results indicate the tendency of phosphorus segregated at grain boundaries.
Influence of Silicon on Nucleation and Growth Process of Spherical Graphite in Ni-C Alloys Solidification Structure
Authors: Meng Di , Wang Xue Tao , Zheng Hong Liang , Tian Xue Lei
Published: February 2018

Plasma etching, SEM and quantitative metallographic analysis technology were used to study the influence of Si on nucleation and growth process of spherical graphite in Ni-C alloys solidification microstructure. Pure Si, Ni-Si alloys and Fe-Si alloys were added into Ni-C melts respectively, and the solid microstructures were compared. The density, diameter size and roundness of spherical graphite were studied in this work to reveal the influence of Si on the morphology of graphite. The Ni-C alloy was etched by plasma etch, and the morphologies and composition of graphite nucleus were observed by scanning electron microscope (SEM) and electron energy spectrum analysis (EDS). The results suggested that the high Si melt zone in melt strongly promoted the enrichment and carbide of graphite, which both promoted the nucleation and growth of graphite. The change in Si content had a large effect on the roundness of the graphite, the higher the Si content, the better the roundness of the graphite.
Rate Theory for Dislocation Loops Evolution in AL-6XN Austenitic Stainless Steel under Proton Irradiation
Authors: Yu Yan Xia , Guo Li Ping , Shen Zheng Yu , Long Yun Xiang , Zheng Zhong Cheng , Tang Rui
Published: February 2018

The average size and density evolution of dislocation loops in AL-6XN austenitic stainless steel, a candidate fuel cladding material for supercritical water-cooled reactor, under proton irradiation were simulated through a rate theory model. The simulation results exhibit relatively good agreement with the experimental results at 563 K. The size and density of defect clusters are calculated under irradiation temperature between 550 K and 900 K and irradiation doses up to 15 dpa which satisfies the working condition in supercritical water-cooled reactor. The fast nucleation between self-interstitials happens at the initial stage of irradiation. The average size of dislocation loops increases while the average density of these loops reduces with the increasing temperature, and the average density approaches to a constant when irradiated at higher irradiation doses. The mechanism is discussed based on the variation of rate constants of defect reactions and the variation of the diffusion coefficients of interstitials and dislocation loops with dose and temperature.
Influence of Sc Addition on the Corrosion Behavior of Medium Strength Al-Zn-Mg Alloy
Authors: Li Zhao Ming , Jiang Hai Chang , Wang Yun Li , Zhang Duo , Yan De Sheng , Rong Li Jian
Published: February 2018

In this paper, the effect of Sc addition (0.06 wt%) on the corrosion behavior of medium strength Al-Zn-Mg alloy is investigated by mass loss measurements, electrochemical experiment, intergranular corrosion and exfoliation corrosion tests. The results indicate the addition of Sc reduces the relative weight loss and enhances pitting performance as a result of grain refinement. The improved intergranular corrosion and exfoliation corrosion resistance caused by minor Sc addition are mainly attributed to the delay in both the initiation and advance stages of local corrosion.
A Facile Method of Preparing Core/Shell Cu@Mo Powders
Authors: Wang De Zhi , Zhang Yu Qing , Duan Bo Hua
Published: February 2018

In this work, Molybdenum trioxide and conventional copper particles were used as precursors, reduced in hydrogen atmosphere. Then Cu@Mo Powders were successfully synthesized. Effects of reduction temperature on the microstructure of the composite powders and the performance of the intermediate product (molybdenum dioxide) were investigated. Results show that 700°C is the optimal reduction temperature, because Mo is reduced from its oxide and forms a coating layer on the surface of copper particles tightly without serious crack. Mo-20wt.% Cu composite powders where Cu is coated uniformly with continuous molybdenum layer are successfully obtained by co-reduction method.
Deformation Behavior and Microstructure Evolution of 6063 Alloy during Hot Compression
Authors: Yu Zhu Hua , Zhang Da Tong , Zhang Wen , Qiu Cheng
Published: February 2018

Hot compression tests of homogenized 6063 Al alloy were carried out in the temperatures range from 390°C to 510°C and strain rates from 1s-1 to 20s-1 on a Gleeble-3500 thermal simulation machine. The results showed that the flow stress decreased with increasing deformation temperature or decreasing strain rate. The dynamic softening effect was more obvious when the alloy was deformed at strain rate of 20 s-1. The Arrhenius-type constitutive equation with strain compensation can accurately describe the flow stress of 6063 aluminum alloy during hot compression. Shear bands appeared in grains interior when the alloy deformed at high strain rates, corresponding to high Zenner-Hollomon (Z) parameters. When deformed under the conditions with low Z parameters, the dynamic recrystallization started occurred.
Preparation and Characterization of Flame Retardant PET Fiber via Melt Blending
Authors: Xu Hui Ling , Bao Hong Kun , Wang Chao Sheng , Wang Hua Ping
Published: February 2018

Poly(ethylene terephthalate) (PET) fiber with excellent flame retardant property was prepared with introducing a containing phosphorus flame retardant 10-(2’,5’-dihydroxyphenyl) -9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (ODOPB) into PET by melt blending method. The intrinsic viscosity of the modified PET was decreased after melt blending, indicated that ODOPB could promote the degradation of PET. The addition of ODOPB can increase the amount of carbon residue of PET, which can effectively reduce the heat transfer. The movement and regularity of PET molecular chain are affected by ODOPB, resulting in the reducing of the crystallization of PET. The Raman curves indicate that the addition of ODOPB can improve the regularity of carbon layer, which is conducive to achieve the effect of flame retardant. When the mass fraction of P is 0.7 %, the limiting oxygen index of sample reaches 32.4% and UL-94 vertical reaches V-2, the fiber fracture strength is 2.6 cN/dtex, which has excellent flame retardant and mechanical properties.
Synthesis and Thermoelectric Properties of WO3/Cu2SnSe3 Composites
Authors: Wu Di , Ning Ji Ai , Zhao De Gang , Wang Xue Zhen , Liu Na
Published: February 2018

In this study, nanometer WO3 powder was uniformly dispersed into the Cu2SnSe3 powder by ball milling process, and the WO3/Cu2SnSe3 thermoelectric composite was prepared by spark plasma sintering (SPS). The results showed that the nano-WO3 particles were mainly distributed in the grain boundary of Cu2SnSe3 matrix, and the grain growth of Cu2SnSe3 was inhibited. The addition of nano-WO3 could enhance the electrical conductivity of Cu2SnSe3, and while the Seebeck coefficient increased slightly for the 0.4% WO3/Cu2SnSe3 composite. The thermal conductivity was not decreased until the content of WO3 exceeded 1.6%. The highest thermoelectric figure of merit ZT of 0.177 was achieved at 700 K for 0.4% WO3/Cu2SnSe3 composite. The enhancement of ZT value of WO3/Cu2SnSe3 thermoelectric material was mainly attributed to the improvement of the electrical properties.
Effects of Calcination Temperature on the Microstructure and Adsorption Properties of Attapulgite Microspheres
Authors: Yan Shu , Pan Yi Ming , Wang Lu , Zhang Xiao Yan , Liu Jing Jing , Yang Jin Long
Published: February 2018

The attapulgite microspheres were produced by spray drying method and calcination process subsequently. The effects of calcination temperature on the microstructure and adsorption properties of methylene blue(MB) were investigated systematically. Results show that the median diameter of the microspheres increases after calcination. The adsorption capacity and removal efficiency of MB reaches the maximum values(96.62mg/g and 96.6%) after calcined at 600°C and decreases with the temperature increasing. The adsorption process can be described better by the pseudo-second-order kinetic model and fit the the Langmuir equation. The attapulgite microsphere shows good adsorption properties, which may be used as potential applications in various dyeing wastewater fields.