bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization and Suitability of Nigerian Barites for Different Industrial Applications
Authors: Otoijamun Itohan , Kigozi Moses , Adetunji Adelana Rasak , Onwualu Peter Azikiwe
Published: March 2021

This work aimed to characterize barite samples from selected different locations in Nigeria and determine their suitability for various industrial applications. The properties determined include mineralogy, chemical composition, morphology, functional groups, and specific gravity. Samples were obtained from ten locations in Nasarawa and Taraba states as well as a standard working sample (WS) obtained from a drilling site. The samples were characterized using scanning electron microscope and energy dispersive X-ray (SEM-EDX), Fourier infrared analysis (FTIR), and X-ray diffraction (XRD). Specific gravity (SG) was determined using the pycnometer method. Results of SEM-EDX analysis show that the WS has a Ba-S-O empirical composition of 66.5% whereas these of the ten samples investigated vary between 59.36% and 98.86%. The FTIR analysis shows that the functional groups of S-O, SO42−, Ba-S-O, OH of the ten samples match that of the WS. Results of XRD show that the ten samples have the same mineralogical composition as the WS and all meet American Petroleum Institute (API) standards for industrial barite. Similar matching results are shown from EDXRF spectra intensity, position, and composition analysis of the ten samples compared to the WS. Specific gravity (SG) results show that six out of the ten samples have SG above 4.2 which is the recommended minimum for the American Petroleum Institute (API) standard. The other four samples will require beneficiation to meet the standard for drilling mud application. Using all the parameters of the assessment together, results show that while some (6) of the samples can be used for drilling fluid application, some (4) require beneficiation but all ten samples can be used for other industrial applications including healthcare, construction, plastic, cosmetics, paper, and rubber industries. The results of the study can be used for value addition in developing beneficiation procedures, processes, and technology for purification along with new materials for the industries.
Recognition of Hydrophilic Cyclic Compounds by a Water-Soluble Cavitand
Authors: Wan Yun-Hui , Zhu Yu-Jie , Rebek Julius , Yu Yang
Published: March 2021

A water-soluble deep cavitand bearing amides on the upper rim and trimethyl ammonium groups on the feet was synthesized. The open-ended cavity is stabilized by the intramolecular hydrogen bonds formed between the adjacent amides, and the introduction of trimethylammonium imparts to the cavitand good solubility in water. The cavitand exhibits high binding affinity and selectivity to hydrophilic molecules in water. With certain guests, such as cyclohexyl alcohols, amines and acids, the recognition involves the synergistic action of hydrogen bonding with hydrophobic effects. The binding phenomena are interpreted in terms of a fixed solvent cage presented by the host to the guest.
Synthesis and Identification of Epoxy Derivatives of 5-Methylhexahydroisoindole-1,3-dione and Biological Evaluation
Authors: Torrent Kariny B. A. , Alvarenga Elson S.
Published: March 2021

Cyclic imides belong to a well-known class of organic compounds with various biological activities, promoting a great interest in compounds with this functional group. Due to the structural complexity of some molecules and their spectra, it is necessary to use several spectrometric methods associated with auxiliary tools, such as the theoretical calculation for the structural elucidation of complex structures. In this work, the synthesis of epoxy derivatives of 5-methylhexahydroisoindole-1,3-diones was carried out in five steps. Diels–Alder reaction of isoprene and maleic anhydride followed by reaction with m-anisidine afforded the amide (2). Esterification of amide (2) with methanol in the presence of sulfuric acid provided the ester (3) that cyclized in situ to give imides 4 and 4-ent. Epoxidation of 4 and 4-ent with meta-chloroperbenzoic acid (MCPBA) afforded 5a and 5b. The diastereomers were separated by silica gel flash column chromatography, and their structures were determined by analyses of the spectrometric methods. Their structures were confirmed by matching the calculated 1H and 13C NMR chemical shifts of (5a and 5b) with the experimental data of the diastereomers using MAE, CP3, and DP4 statistical analyses. Biological assays were carried out to evaluate the potential herbicide activity of the imides. Compounds 5a and 5b inhibited root growth of the weed Bidens pilosa by more than 70% at all the concentrations evaluated.
The Inhibitory Effects of Plant Derivate Polyphenols on the Main Protease of SARS Coronavirus 2 and Their Structure–Activity Relationship
Authors: Nguyen Thi Thanh Hanh , Jung Jong-Hyun , Kim Min-Kyu , Lim Sangyong , Choi Jae-Myoung , Chung Byoungsang , Kim Do-Won , Kim Doman
Published: March 2021

The main protease (Mpro) is a major protease having an important role in viral replication of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the novel coronavirus that caused the pandemic of 2020. Here, active Mpro was obtained as a 34.5 kDa protein by overexpression in E. coli BL21 (DE3). The optimal pH and temperature of Mpro were 7.5 and 37 °C, respectively. Mpro displayed a Km value of 16 μM with Dabcyl-KTSAVLQ↓SGFRKME-Edans. Black garlic extract and 49 polyphenols were studied for their inhibitory effects on purified Mpro. The IC50 values were 137 μg/mL for black garlic extract and 9–197 μM for 15 polyphenols. The mixtures of tannic acid with puerarin, daidzein, and/or myricetin enhanced the inhibitory effects on Mpro. The structure–activity relationship of these polyphenols revealed that the hydroxyl group in C3′, C4′, C5′ in the B-ring, C3 in the C-ring, C7 in A-ring, the double bond between C2 and C3 in the C-ring, and glycosylation at C8 in the A-ring contributed to inhibitory effects of flavonoids on Mpro.
Editorial: Trends in Optical/Laser Spectroscopy and Applications
Authors: Pascu Mihail Lucian
Published: March 2021

Optics and optical spectroscopy are dynamic fields that are developing very fast nowadays, triggered by (i) the need to go deeper in the scientific approach to nature’s processes and phenomena, (ii) the evolution of applications in technological and industrial processes, art conservation, environment protection and cosmic space, and (iii) the sometimes hard to predict evolutions of knowledge in science, life sciences, artistic culture, technology and industrial processes [...]
Was Pauling Mistaken about Metals?
Authors: Savin Andreas
Published: March 2021

Pauling described metallic bonds using resonance. The maximum probability domains in the Kronig–Penney model can show a picture of it. When the walls are opaque (and the band gap is large) the maximum probability domain for an electron pair essentially corresponds to the region between the walls: the electron pairs are localized within two consecutive walls. However, when the walls become transparent (and the band gaps closes), the maximum probability domain can be moved through the system without a significant loss in probability.
An Integrative Approach of an In Vitro Measurement of the Digestibility of Triacylglycerols of Human Milk
Authors: Pérez-Gálvez Antonio , Calvo María Visitación , Aguayo-Maldonado Josefa , Fontecha Javier
Published: March 2021

Several studies have been published regarding the effect of different factors on the digestion of milk lipids, considering their natural structural arrangement as milk fat globules and the efficiency of the digestive enzymes in the lipolysis of such complex structures. During digestion, the lipolytic products are dispersed in vesicles and micelles, which are the source for absorption of digested lipids. Therefore, it is necessary to consider the isolation of the micellar phase from the digesta to appropriately determine the amounts and classes of lipids which are bioaccessible. This study presents an integrative approach that included an isolation procedure to separate the micellar fraction from undigested and non-micellar parts, and the distribution of digested milk lipids in micelles determined directly through chromatographic techniques. Four groups of five full term mothers donated colostrum or mature milk. Two sets of samples were analyzed directly (raw), and two sets were pasteurized and then analyzed. Our data revealed that the profile of digested milk lipids is different depending on the lactation period and processing stage, while the carbon atom number distribution of the digested triacylglycerols in the micellar fraction provides a substantial information regarding the acylglycerols species that are less available for absorption.
Protective Effect of Two Alkaloids from Hippophae rhamnoides Linn. against Doxorubicin-Induced Toxicity in H9c2 Cardiomyoblasts
Authors: Zhou Wenna , Ouyang Jian , Hu Na , Li Gang , Wang Honglun
Published: March 2021

Background: Doxorubicin (Dox) is one of the most frequently prescribed anti-cancer drugs. However, clinical application with Dox is limited due to its potentially fatal cumulative cardiotoxicity. N-p-coumaroyl-4-aminobutan-1-ol (alk-A), an organic amide alkaloid and hippophamide (alk-B), a rare pyridoindole alkaloid were successfully obtained by purification and separation of seabuckthorn seed residue in our previous research. This study was undertaken to investigate the protective effect of alk-A and alk-B against Dox-induced embryonic rat cardiac cells (H9c2 cells) apoptosis. Methods: H9c2 cells were treated with Dox (2.5 µM) in the presence of alk-A and alk-B (10, 20, and 40 µM) and incubated for 24 h. Results: It was shown that pretreatment of the H9c2 cells with alk-A and alk-B significantly reduced Dox-induced apoptosis. Alk-A and alk-B both inhibited reactive oxygen species (ROS) production and suppressed cleaved-caspase-3 protein expression and the activation of JNK (Jun N-terminal kinases), as well as increasing ATP levels, favoring mitochondrial mitofusin protein expression, and relieving damage to mitochondrial DNA. Conclusions: These results suggest that alk-A and alk-B can inhibit Dox-induced apoptosis in H9C2 cardiac muscle cells via inhibition of cell apoptosis and improvement of mitochondrial function, while alk-B showed more protection. Alk-B could be a potential candidate agent for protecting against cardiotoxicity in Dox-exposed patients.
Computational Study of the Electron Spectra of Vapor-Phase Indole and Four Azaindoles
Authors: Chong Delano P.
Published: March 2021

After geometry optimization, the electron spectra of indole and four azaindoles are calculated by density functional theory. Available experimental photoemission and excitation data for indole and 7-azaindole are used to compare with the theoretical values. The results for the other azaindoles are presented as predictions to help the interpretation of experimental spectra when they become available.
Physiological and Immunological Changes Associated with Oral Microbiota When Using a Thermoplastic Retainer
Authors: Al-lehaibi Wurood kh. , Al-makhzomi Khulood A. , Mohammed Hani Sh. , Enezei Hamid Hammad , Alam Mohammad Khursheed
Published: March 2021

Background: The study examined the oral microbiota, physiological and immunological changes in patients using thermoplastic retainers during three months of use. Methods: The study included several steps. Firstly, 10 swabs were collected from the buccal and palatal surfaces of the teeth of the patients, approximately 2 mL of saliva was collected from the same patients and 2 mL of saliva was collected from 10 healthy people to measure the pH and secretory IgA level. This was followed by the isolation and identfication of the bacterial isolates in the patient samples. Then, isolate susceptibility toward chlorhexidine (CHX) and their adhesion ability to thermoplastic retainer surfaces was measured. In addition to that the study estimated the numbers of Lactobacillus and Streptooccus mutans colonies during three months and finally, a comparsion of pH acidity and IgA level between the patients and healthy people was performed. The results showed the predominant bacteria during the three months were Lactobacillus spp. and Streptococcus spp. followed by different rates of other bacteria. Raoultella ornithinolytica showed more resistance to CHX while Lactobacillus spp. showed more sensitivity. Streptococcus mutans colony levels were higher than Lactobacillus spp. colonies during the three months, also S. mutans had the highest value in adherence to retainer thermoplastic. Finally, pH acidity showed a highly significant difference (p ≤ 0.05) in the third month, like IgA levels (p ≤ 0.05). Conclusions: According to the results obtained from the current study, the researchers noted that the thermoplastic retainers helped change the oral cavity environment.
Assessment of Protocol Impact on Subjectivity Uncertainty When Analyzing Peripheral Blood Mononuclear Cell Flow Cytometry Data Files
Authors: Grant Rebecca , Coopman Karen , Silva-Gomes Sandro , Campbell Jonathan , Kara Bo , Braybrook Julian , Petzing Jon
Published: March 2021

Measured variability of product within Cell and Gene Therapy (CGT) manufacturing arises from numerous sources across pre-analytical to post-analytical phases of testing. Operators are a function of the manufacturing process and are an important source of variability as a result of personal differences impacted by numerous factors. This research uses measurement uncertainty in comparison to Coefficient of Variation to quantify variation of participants when they complete Flow Cytometry data analysis through a 5-step gating sequence. Two study stages captured participants applying gates using their own judgement, and then following a diagrammatical protocol, respectively. Measurement uncertainty was quantified for each participant (and analysis phase) by following Guide to the Expression of Uncertainty in Measurement protocols, combining their standard deviations in quadrature from each gating step in the respective protocols. When participants followed a diagrammatical protocol, variation between participants reduced by 57%, increasing confidence in a more uniform reported cell count percentage. Measurement uncertainty provided greater resolution to the analysis processes, identifying that most variability contributed in the Flow Cytometry gating process is from the very first gate, where isolating target cells from dead or dying cells is required. This work has demonstrated the potential for greater usage of measurement uncertainty within CGT manufacturing scenarios, due to the resolution it provides for root cause analysis and continuous improvement.
Dual-Cation Electrolytes Crosslinked with MXene for High-Performance Electrochromic Devices
Authors: Bae Soyoung , Kim Youngno , Kim Jeong Min , Kim Jung Hyun
Published: March 2021

MXene, a 2D material, is used as a filler to manufacture polymer electrolytes with high ionic conductivity because of its unique sheet shape, large specific surface area and high aspect ratio. Because MXene has numerous -OH groups on its surface, it can cause dehydration and condensation reactions with poly(4-styrenesulfonic acid) (PSSA) and consequently create pathways for the conduction of cations. The movement of Grotthuss-type hydrogen ions along the cation-conduction pathway is promoted and a high ionic conductivity can be obtained. In addition, when electrolytes composed of a conventional acid or metal salt alone is applied to an electrochromic device (ECD), it does not bring out fast response time, high coloration efficiency and transmittance contrast simultaneously. Therefore, dual-cation electrolytes are designed for high-performance ECDs. Bis(trifluoromethylsulfonyl)amine lithium salt (LiTFSI) was used as a source of lithium ions and PSSA crosslinked with MXene was used as a source of protons. Dual-Cation electrolytes crosslinked with MXene was applied to an indium tin oxide-free, all-solution-processable ECD. The effect of applying the electrolyte to the device was verified in terms of response time, coloration efficiency and transmittance contrast. The ECD with a size of 5 × 5 cm2 showed a high transmittance contrast of 66.7%, fast response time (8 s/15 s) and high coloration efficiency of 340.6 cm2/C.
Cellulose Nanofiber-Based Nanocomposite Films Reinforced with Zinc Oxide Nanorods and Grapefruit Seed Extract
Authors: Roy Swarup , Kim Hyun Chan , Panicker Pooja S. , Rhim Jong-Whan , Kim Jaehwan
Published: March 2021

Here, we report the fabrication and characterization of cellulose nanofiber (CNF)-based nanocomposite films reinforced with zinc oxide nanorods (ZnOs) and grapefruit seed extract (GSE). The CNF is isolated via a combination of chemical and physical methods, and the ZnO is prepared using a simple precipitation method. The ZnO and GSE are used as functional nanofillers to produce a CNF/ZnO/GSE film. Physical (morphology, chemical interactions, optical, mechanical, thermal stability, etc.) and functional (antimicrobial and antioxidant activities) film properties are tested. The incorporation of ZnO and GSE does not impact the crystalline structure, mechanical properties, or thermal stability of the CNF film. Nanocomposite films are highly transparent with improved ultraviolet blocking and vapor barrier properties. Moreover, the films exhibit effective antimicrobial and antioxidant actions. CNF/ZnO/GSE nanocomposite films with better quality and superior functional properties have many possibilities for active food packaging use.
Surface-Enhanced Raman Spectroscopy for Bisphenols Detection: Toward a Better Understanding of the Analyte–Nanosystem Interactions
Authors: Roschi Eleonora , Gellini Cristina , Ricci Marilena , Sanchez-Cortes Santiago , Focardi Claudia , Neri Bruno , Otero Juan Carlos , López-Tocón Isabel , Smulevich Giulietta , Becucci Maurizio
Published: March 2021

Silver nanoparticles functionalized with thiolated β-cyclodextrin (CD-SH) were employed for the detection of bisphenols (BPs) A, B, and S by means of surface-enhanced Raman spectroscopy (SERS). The functionalization of Ag nanoparticles with CD-SH leads to an improvement of the sensitivity of the implemented SERS nanosensor. Using a multivariate analysis of the SERS data, the limit of detection of these compounds was estimated at about 10−7 M, in the range of the tens of ppb. Structural analysis of the CD-SH/BP complex was performed by density functional theory (DFT) calculations. Theoretical results allowed the assignment of key structural vibrational bands related to ring breathing motions and the inter-ring vibrations and pointed out an external interaction due to four hydrogen bonds between the hydroxyl groups of BP and CD located at the external top of the CD cone. DFT calculations allowed also checking the interaction energies of the different molecular species on the Ag surface and testing the effect of the presence of CD-SH on the BPs’ affinity. These findings were in agreement with the experimental evidences that there is not an actual inclusion of BP inside the CD cavity. The SERS sensor and the analysis procedure of data based on partial least square regression proposed here were tested in a real sample consisting of the detection of BPs in milk extracts to validate the detection performance of the SERS sensor.
Modeling and Measurement of Thermal Effect in a Flashlamp-Pumped Direct-Liquid-Cooled Split-Disk Nd:LuAG Ceramic Laser Amplifier
Authors: Ji Shengzhe , Huang Wenfa , Feng Tao , Pan Long , Wang Jiangfeng , Lu Xinghua , Jiang Benxue , Fan Wei , Li Xuechun
Published: March 2021

In this paper, a model to predict the thermal effects in a flashlamp-pumped direct-liquid-cooled split-disk Nd:LuAG ceramic laser amplifier has been presented. In addition to pumping distribution, the model calculates thermal-induced wavefront aberration as a function of temperature, thermal stress and thermal deformation in the gain medium. Experimental measurements are carried out to assess the accuracy of the model. We expect that this study will assist in the design and optimization of high-energy lasers operated at repetition rate.
The Distribution of Minerals in Crucial Plant Parts of Various Elderberry (Sambucus spp.) Interspecific Hybrids
Authors: Imenšek Nataša , Sem Vilma , Kolar Mitja , Ivančič Anton , Kristl Janja
Published: March 2021

In view of growing requirements of the food industry regarding elderberries (genus Sambucus), a need to increase their productivity and improve their chemical composition has emerged. With this purpose in mind, numerous elderberry interspecific hybrids have been created. In the present work, the content of minerals in their crucial plant parts was studied. It was also investigated whether superior genotypes regarding the mineral composition of berries and inflorescences could be predicted at early stages of plant development. The results showed that elderberry leaves contained the highest amounts of Ca, Mg, Mn, Zn, and Sr, while K and P were predominant in fruit stalks. Fe and Al prevailed in roots and Cu in bark. Although berries showed lower mineral content compared to other plant parts, their mineral content is not negligible and could be comparable to other commonly consumed berries. Genotypes with a favorable mineral content of inflorescences and berries could be predicted on the basis of known mineral composition of their shoots and leaves. The study also indicates that S. nigra genotypes and the majority of interspecific hybrids analyzed are suitable for further genetic breeding or cultivation.
Seedling Responses to Organically-Derived Plant Growth Promoters: An Effects-Based Approach
Authors: Hodge Simon , Merfield Charles N. , Liu Wendy Y. Y. , Tan Heng W.
Published: March 2021

Organically-derived biofertilizers and biostimulants, developed from harvested materials such as seaweed and waste from animal and fish processing, are currently the subject of much fundamental and applied research. These products have significant potential in reducing synthetic fertilizer inputs to horticultural, arable, and pasture-based agricultural systems, although there is frequently some ambiguity over the magnitude and consistency of any positive effects these products may have on plant performance. This study examined the effects of organically-derived plant growth promoters (PGPs) available in New Zealand on the early vegetative growth of 16 plant species maintained under glasshouse conditions. When applied as a root drench to low nutrient potting mix, the effects of the PGPs on seedling shoot growth were strongly related to the NPK contents of the applied solutions. Any positive effects on shoot growth were, on average, reduced when the seedlings were maintained in higher nutrient growing media. Applying the PGPs at concentrations twice, and four times, the recommended concentration, only caused further growth responses when the PGPs contained high levels of nutrients. Applying the PGPs as a foliar spray had negligible effects on shoot growth. Overall, the results of these trials suggest that the positive effects of applying some organically-derived PGPs on seedling growth are a function of the PGP nutrient content, and not due to any indirect effects related to phytohormone pathways or modification of rhizosphere microorganisms.
Implementation and Parameter Analysis of the Knock Phenomenon of a Marine Dual-Fuel Engine Based on a Two-Zone Combustion Model
Authors: Zou Fang-kun , Zeng Hong , Wang Huai-yu , Wang Xin-xin , Xu Zhao-xin
Published: March 2021

The stable working window of a dual-fuel engine is narrow, and it is prone to knock during operation. The occurrence of knock limits the load and torque output of a dual-fuel engine, and even causes engine damage in severe cases. The existing volumetric model of marine dual-fuel engine has little research on the related problems of knock simulation. In order to analyze the causes of knock phenomenon and the influence of operating parameter changes on knock, under the Matlab/Simulink simulation environment, a quasi-dimensional model was established with MAN 8L51/60DF dual-fuel engine as the prototype, and the model was calibrated using the bench data. The knock intensity index coefficient (KI) was used as the evaluation index of knock intensity. Three parameters, the intake air temperature, compression ratio, and natural gas intake, were selected as variables to simulate the engine. According to the analysis of the simulation results, the influence of the parameter changes on the occurrence of engine knock phenomenon and knock intensity could be further studied. The results showed that the combination of the KI model and the quasi-dimensional model could effectively and accurately predict the engine performance and knock trend. The change of gas inlet quality, compression ratio, and inlet temperature could promote the occurrence of detonation, the engine knock could be avoided by controlling the intake air temperature below 336 K, compression ratio not exceeding 15 or the intake volume of natural gas per cycle not exceeding 11.25 g/cycle.
Pressure Relief by Blasting Roof Cutting in Close Seam Group Mining under Thick Sandstone to Enhance Gas Extraction for Mining Safety
Authors: Gao Kui , Huang Ping , Liu Ze-Gong , Liu Jian , Wang Fei , Shu Chi-Min
Published: March 2021

Close seam group mining under thin immediate roofs and thick sandstone walls is typically performed with a strong mine pressure and gas concentration, which pose considerable risks to miners. In this study, the mechanism of pressure relief and permeability enhancement to enhance gas extraction for mining safety through blasting roof cutting were investigated through theoretical analyses, numerical simulations, and laboratory tests. The results revealed that, near the blast-hole, which produced numerous cracks, blasting disturbed the integrity of the thick-layer roofs and redistributed the stress near the blast-hole, which prevented violent mine pressure caused by excessive fracture distances on the thick and hard roofs, reduced the additional load on the support, increased vertical gas migration, and ameliorated the effect of gas drainage caused by high-level boreholes. The field applications of forced roof cutting through deep-hole blasting in the II 7224N face of the Renlou coal mine (Huaibei, Anhui, PR China) demonstrated that the occurrence of excessive pressure on the fully mechanized mining hydraulic support was prevented. The gas extraction volume of high-level boreholes was maintained at 6–8 m3/min; the extraction concentration was stable at approximately 35%; and the gas concentration in the upper corner of the coal face was lessened from 7% to <1%, which ensured normal mining in the coal face. The current results can provide data reference and a theoretical basis for roof management and gas control of the same type of coal face.
Measurement and Calibration of the Parameters for Discrete Element Method Modeling of Rapeseed
Authors: Cao Xiulong , Li Zehua , Li Hongwei , Wang Xicheng , Ma Xu
Published: March 2021

The discrete element method (DEM) for modeling the behavior of particulate material is highly dependent on the use of appropriate and accurate parameters. In this study, a seed metering DEM simulation was used to measure, calibrate, and verify the physical and interactional parameters of rapeseed. The coefficients of restitution and static friction between rapeseeds and three common materials (aluminum alloy, acrylic, and high-density polyethylene) were measured using free drop and sliding ramp tests, respectively. The angle of repose was determined using a hollow cylinder experiment, which was duplicated using a DEM simulation, to examine the effects of static and rolling friction coefficients on the angle of repose. Response surface optimization was performed to determine the optimized model parameters using a Box–Behnken design test. A metering device was made with three materials, and rapeseed seeding was simulated at different working speeds to verify the calibrated parameters. The validation results showed that the relative errors between the seed metering model and experiments for the single qualified seeding, missed seeding, and multiple seeding rates were −0.15%, 3.29%, and 5.37%, respectively. The results suggest that the determined physical and interactional parameters of rapeseed can be used as references for future DEM simulations.
Um novo olhar? A (des)construção do fazer jornalístico tradicional nas colunas políticas de Eliane Brum no El País
Authors:   , Quadros Ana Resende
Published: March 2021

A proposta do trabalho é fazer uma análise de conteúdo, aos moldes de Bardin (2011), das colunas políticas publicadas por Eliane Brum no site do jornal global El País ao longo do ano de 2019 com o objetivo de averiguar se é possível e, se sim, de que forma, uma associação entre o jornalismo político e o jornalismo literário na internet. Para tanto, serão analisadas as temáticas tratadas por Brum em seus textos e sua proximidade com o jornalismo do Acontecimento ou do Desacontecimento, as fontes e personagens abordados, a proximidades e afastamentos dos textos de Brum com as características das colunas políticas, do jornalismo literário e do webjornalismo. Ao longo deste trabalho, foi possível perceber que Eliane Brum optou por não usar recursos literários com frequência. Isso não quer dizer, porém, que seja impossível usar esses recursos em textos políticos escritos para a internet.
O desafio da transição das turmas de 5º ano para o 6º ano do ensino fundamental: o caso da Escola Estadual Domingos Pimenta de Figueiredo
Authors:   , Damas César Emanuel Sampaio
Published: March 2021

Este trabalho é desenvolvido no âmbito do Mestrado Profissional em Gestão e Avaliação da Educação (PPGP) do Centro de Políticas Públicas e Avaliação da Educação da Universidade Federal de Juiz de Fora (CAEd/UFJF). A pesquisa apresenta o caso de gestão que discute o desafio de transição de turmas de 5º ano dos Anos Iniciais do Ensino Fundamental para o 6° ano dos Anos Finais do Ensino Fundamental na Escola Estadual Domingos Pimenta de Figueiredo (EEDPF), situada na cidade de Capelinha - MG, que apresenta variação do rendimento entre essas duas etapas. Neste sentido, a pesquisa tem como objetivo geral compreender de que forma vem ocorrendo a transição dos alunos do 5º para o 6º ano do Ensino Fundamental nessa instituição de ensino entre os anos de 2015 a 2019. São objetivos específicos desta pesquisa: (i) descrever o processo de transição de turmas de 5º ano dos Anos Iniciais do Ensino Fundamental para o 6° ano dos Anos Finais do Ensino Fundamental na EEDPF; (ii) analisar os resultados de avaliações e as especificidades pedagógicas do 5° e do 6° ano do Ensino Fundamental da Escola Estadual Domingos Pimenta de Figueiredo; e (iii) propor um Plano de Ação Educacional (PAE) que vise colaborar para a transição do 5° para o 6° ano do Ensino Fundamental da instituição, de forma a possibilitar o bom desempenho e a aprendizagem dos alunos. Para a discussão teórica, trazemos autores como Gatti (2003), Hoffmann (2000, 2013), Luckesi (2000, 2005), entre outros. Para a obtenção dos dados, utilizamos, como metodologia, a pesquisa qualitativa por meio de entrevistas com roteiro semiestruturado com as especialistas em educação (supervisoras) e questionários com professores dos Anos Iniciais e Finais e com alunos que fizeram a transição dessas etapas na escola. Os resultados da pesquisa indicam a necessidade de a gestão escolar articular ações com os diversos segmentos da comunidade escolar para a implementação de uma proposta curricular integrada capaz de atender às especificidades e ao tempo de cada aluno. De posse dessas análises, construiu-se um PAE cujas ações foram propostas a partir da necessidade de promover uma melhor organização e acompanhamento entre os segmentos Anos Iniciais e Anos Finais, a fim de minimizar a queda de resultados dos alunos; promover uma maior apropriação e integração curricular na instituição; proporcionar uma reflexão e trocas de experiências na busca da integração curricular; integrar a comunidade escolar por meio de momentos, como rodas de conversas; motivar o protagonismo dos alunos através das lideranças de turmas; e sensibilizar os estudantes para a construção de seus projetos de vida.
Conjunto didático de ótica: uma proposta prática para o ensino de luz e cor
Authors:   , Morais Cristian Nunes de
Published: March 2021

Este trabalho apresenta o desenvolvimento e a aplicação de um conjunto didático óptico associado a uma sequência didática construtivista para o ensino de conceitos de luz branca, reflexão e dispersão da luz e percepção de cor. O conjunto didático é composto por um espectrógrafo e uma Caixa de Luz, construídos com materiais acessíveis e de baixo custo, e permite que os fenômenos ópticos sejam apresentados de maneira atrativa para os alunos. Na Caixa de Luz, LEDs coloridos permitem observar a reflexão da luz e a formação da luz branca, além das possíveis combinações entre LEDs diferentes para trabalhar a percepção de cores, permitindo discutir os sistemas RGB e CMKY. O conjunto possui também corantes que permitem trabalhar as combinações de pigmentos e comparar os dois sistemas. O fidget spinner, um brinquedo popular, é utilizado para trabalhar as combinações de cores e a formação de luz branca. Esse conjunto foi aplicado em uma turma de alunos do terceiro ano do ensino médico de uma escola pública estadual da periferia de Juiz de Fora, MG, orientado por uma sequência didática para o ensino de luz e cor. A aplicação ocorreu em quatro aulas de 50 minutos em maio de 2019. A análise dos resultados obtidos em sala de aula, juntamente com os relatórios elaborados pelos alunos, permitiu o aperfeiçoamento do produto para sua atual configuração. Conclui-se que o Produto Final, constituído pelo conjunto óptico e pela sequência didática, atingiu a expectativa inicial, estimulando os alunos a interagir com os fenômenos observados para encontrar as respostas para as situações didáticas propostas. As atividades sugeridas motivaram a participação dos alunos em grupo, estimulando o debate em sala de aula, e criando um ambiente de aprendizagem ativo e favorável.
FDG PET Görüntülemelerin Kantitatif Değerlendirilmesi
Authors: SEZGİN Ceren , PARLAK Yasemin , MÜTEVELİZADE Gözde , GÜMÜŞER Gül , S.BİLGİN Elvan
Published: March 2021

Pozitron emisyon tomografi/ bilgisayarlı tomografi onkolojik vakalarda tanı, evreleme, prognoz ve tedaviye yanıt için giderek artan kullanım alanına sahiptir. PET’in en büyük avantajı radyofarmasötik uptake’ini ölçebilmek ve en çok kullanılan parametre olan standardize uptake değeri (SUV) şeklinde sayısal sonuç vermesidir. SUV hesaplamaları rekonstrükte edilmiş PET ve BT görüntülerinden elde edilir. 18F-FDG PET/BT bulgularından elde edilen semikantitatif ölçümler (SUV) benign-malign lezyon ayırımında en önemli parametrelerdir. SUV ölçüm farklılıkları, onkolojik hastalarda tedavi yanıtı ve tedavi planlaması için yarı kantitatif bir görüntüleme biyobelirteci olan PET tabanlı ölçümün klinik etkinliğini değiştirir.
Hepatobiliyer Hastalıklarda Tanıya Yönelik Görüntüleme Yöntemlerinden Endoskopik Retrograd Kolanjiopankreatografi ve Manyetik Rezonans Kolanjiopankreatografinin Etkinliğinin Karşılaştırılması
Authors: BAYKAN Ahmed Ramiz , BURAN Tahir , GERÇEKER Emre , YÜCEYAR Hakan , TARHAN Serdar , KASAP Elmas , PEKİNDİL Gökhan
Published: March 2021

Amaç: Manyetik rezonans kolanjiopankreatografinin tanıya yönelik etkinliğini tanıda altın standart olarak kabul edilen endoskopik retrograd kolanjiopankreatografi ile kıyaslayarak değerlendirmeyi planladık.

Gereç ve yöntem: Celal Bayar Üniversite hastanesi gastroenteroloji kliniğine 2012-2014 yılları arasında başvurup, Manyetik rezonans kolanjiopankreatografi ve sonrasında endoskopik retrograd kolanjiopankreatografi yapılan hastaların dosyaları retrospektif olarak incelendi

Bulgular: Çalışmaya 53 erkek, 57 kadın toplam 110 hasta dâhil edildi. Hastaların ortalama yaşı 63,56±16,897 olarak saptandı. Endoskopik retrograd kolanjiopankreatografi altın standart olarak alındığında ve kanülasyon sağlanamayan hastalar çıkarıldığında koledokolitizis için manyetik rezonans kolanjiopankreatografinin sensitivitesi (%66,6), spesifitesi (%82,8) olarak saptandı. Manyetik rezonans kolanjiopankreatografinin pozitif prediktif değeri (%86,9), negatif prediktif değeri (%59,1) olarak saptandı. 5 mm ve büyük taşlar dikkate alındığında, manyetik rezonans kolanjiopankreatografinin duyarlılığının %91,9’ a çıktığı görüldü. Hepatobiliyer malignitelerde, manyetik rezonans kolanjiopankreatografinin sensitivitesi (%69,56), spesifitesi (%100) olarak saptandı. Manyetik rezonans kolanjiopankreatografinin hepatobiliyer maligniteler için pozitif prediktif değeri (%100), negatif prediktif değeri (%91,13) olarak saptandı.

Sonuç: Hepatobiliyer hastalıkların tanısını koymada göstermiş olduğu yüksek sensitivite ve spesifite değerleri nedeni ile manyetik rezonans kolanjiopankreatografi, günümüzde tanı alanında endoskopik retrograd kolanjiopankreatografinin yerini büyük ölçüde almıştır. Teknolojinin gelişmesi ile birlikte daha iyi görüntü kalitesi sonucu tanı alanında bu etkinliğinin daha çok büyümesi beklenmektedir
Potensi Isolat Kamir Filosfer Buah Cabai sebagai Antagonis Terhadap Patogen Antraknosa
Authors: Sulaiman Ahmad , Rianto Fadjar , Sarbino Sarbino
Published: March 2021

Anthracnose disease in chili is caused by C. acutatum. This disease can cause a decrease in quality and production of chili pepper. The use of biological control agents can be an alternative in controlling of C. acutatum. The use of biological agents is more environmentally friendly and reduces the negative effects of synthetic pesticides. This study aims to obtain yeast isolates from the phyllosphere that have the potential to suppress anthracnose disease. The research was carried out at the Laboratory of Diseases at the Faculty of Agriculture, Tanjungpura University, Pontianak from July to October 2019. Yeast isolation used a pouring plate method on the media YGCA after the yeast on the fruit surface was enriched in liquid media YGC during 24 hours. Yeast antagonism test against C. acutatum using the dual culture method, conidia viability, and the ability of pathogens to infect fruit. The results of the isolation obtained 8 yeast isolates in healthy chili of Gada variety. Antagonism test obtained 3 yeast isolates with the highest inhibitory to C. acutatum growth, isolates K2, K3 and K5. Inhibition is greater than 50%. Based on the severity index of the disease in the hypovirulent test, the three yeast isolates were not pathogenic. In the in vivo test with the immersion method, both using yeast cells and filtrate showed that yeast cells could inhibit the growth of C. acutatum infection ability better than yeast filtrate. All yeast isolates can suppress the growth of C. acutatum with a different percentage of disease.
Angeborene Stoffwechselkrankheiten beim Erwachsenen: Wie sieht es in der Schweiz aus?
Authors: Tran Christel , Superti-Furga Andrea , Hochuli Michel
Published: March 2021

Angeborene Stoffwechselkrankheiten (ASK) sind die Folge eines genetischen Defektes von Enzymen oder regulierenden Eiweissen, die in einige metabolische Prozesse eingreifen. Ziel dieses Artikels ist es, eine Übersicht des Netzwerkes zu geben, das sich um die ASK im Erwachsenenalter gebildet hat, und die Besonderheiten der Betreuung dieser Patienten anhand einiger emblematischen Fällen zu beschreiben.
Proposal for a digital forensic investigation model in accordance with the legislation in Mexico
Authors: Ortega-Laurel Carlos , Sandoval-Gutierrez Jacobo , Lopez-Sauceda Juan , Serrano-Orozco Adan Fernando
Published: March 2021

In this paper we collect and observes the existing digital forensic investigation models, which are essentially the application of information systems and communications engineering for forensic purposes. In addition, a review of the federal criminal situation in Mexico is presented (through the revision of the regulations in the Federal Criminal Code), because the Code indirectly describes the reality of what can be prosecuted and admitted as evidence, criminally speaking, with the application of digital forensic investigation models in Mexico. This is due to the significant deficiency in the proposal of digital forensic investigation models, in which there is not enough emphasis on the potential admissibility of the evidence gathered through the models, to give attention to the need to provide “evidence” to Institutions responsible for the impartation of justice, as if doing digital forensic investigation to be a technological issue and not as it really is: a socio-legal-technological issue. Therefore, considering the criminal reality in Mexico, locating the practices of existing models that make sense in accordance with the norm, an abbreviated model is proposed that really helps successful prosecutions.
Integración de Actuadores Hidráulicos para los Sistemas Secundarios de Moldeo y Liberación en Moldes de Inyección de Plástico
Authors: Reyes-Castrejon Daniel Enrique , Bonilla-Blancas Angélica Elizabeth , Figueroa-Estrada Eduardo , Salazar-Pereyra Martín
Published: March 2021

The manufacture of plastic products in the current markets demands the use of technologies that allow the molding of components with highly complex geometries and every time the time to manufacture is reduced. The presence of subsystems for the molding and release of negative structures increases the complexity of the mould, as well as the time required for the manufacture and adjust of the mould, since it is traditionally used mechanisms with angular pins. In this work the design of an injection mould is made for a component with negatives, which uses a system with actuator for the secondary molding and release of the negative structure according to the mould partition line. The mold is also design for the same component with the use of a secondary system of moulding totally mechanical and of conventional use. The analysis of the design and operation between a secondary mechanical molding system and a system with actuator for molding and releasing negative structures in plastic injection molds, alternative for reducing costs and times of Manufacturing.
Efecto de parámetros de mínima cantidad de lubricación en reducción de desgaste de herramienta
Authors: Martínez-Ramírez Israel , Gutiérrez-Rivera Miguel Ernesto , Espinoza-Torres Isaí , Rodríguez-Flores Javier
Published: March 2021

The objective of this work is to determine the influence of Minimum Quantity Lubrication (MQL) parameters on flank wear during face milling. Furthermore, the values of each factor in which the MQL resulted to be effective were determined. A designed experiment with two level, three factor and two replicas was used to test tool wear on P45 grade inserts at relatively high cutting speed (~900 m/min) on steel AISI 1045. A commercial MQL system was used with vegetable base lubricant non soluble in water. Results show that amount of lubricant and vertical angle are key factors that affects the effectiveness of the process. A response surface equation was obtained in order to determine the zones in which the factors resulted in the lowest tool wear. A flank wear decrease of 7 times, respect to the maximum observed, was found by using low level of air flow, low level of vertical angle and high level of lubricant.
Análisis termodinámico de las condiciones de operación de los ciclos combinados turbina de gas-vapor con uno, dos y tres niveles de presión
Authors: Méndez-Cruz Ladislao Eduardo , Salazar-Pereyra Martín , Lugo-Leyte Raúl , Pérez-Bedolla Rafael
Published: March 2021

The technology of gas-steam turbine combined cycles is once of the most viable options for the generation of electric power with lower costs of production per kilowatt-hour and environmental, considering that the type of fuel should be gas natural. In the Mexican Republic, the projections of power generation to 2018 through the use of this technology, it establishes the possibility to install new power generation plants with pressures of 100 to 160 bar, and temperatures of 538 to 580°C. Another option it’s the repowering of the thermoelectric plants and cogeneration gas-steam turbines projects. Therefore, in this paper present a thermodynamic analysis of the configurations of combined cycles of one, two and three pressure levels with the objective in order to establish a parametric analysis of the power generation capacity, as well the thermal efficiency and Heat Rate based on the characteristics of the gas and steam turbines, likewise the quality of the last expansion stage has considered as a restriction to delimit the pressure of the steam domes of each level.
Oztibarreko mintzoaz eta haren lexikoaz
Authors: Camino Lertxundi Iñaki
Published: March 2021

Saioak hasieran Baxenabarreko euskaraz dagoen ikuspegi orokorra aurkezten du eta Hazparnek ezker-eskuin eta goi-behe hizkuntzaren aldetik ukan duen eraginaz proposamen bat egiten. Ondotik oztibartarren abeltzain-gizarteaz eta eskualdeko jendeen hartu-emanez ohar batzuk egiten dira. Hizkuntzaren atalean alderdi foniko eta morfosintaktikoez aurkezpen zabalxea egin da, non ageri baita Oztibarreko mintzoa Baxenabarreko erdigune-erdigunekoa dela, ez duela berezko ezaugarririk eta ondoko mintzoekin  komunikazio-maila gora duela, nahiz badiren ekialde honetara heldu ez diren berrikuntza zenbait; bestalde, ahal izan den heinean hondarreko mendeetako hizkuntza-bilakabide batzuen berri ere eskaini da. Lexikoaz eta item lexikoen aldaera fonikoez egin den azterketak erakusten dituen bi lotura sendoenak, Garazi alderat eta Zuberoa alderat doazenak dira; Landibarren Baxenabarre mendebaleko euskararen eragin poxi bat ere ageri da. Oro har mintzo bateratuxea ageri zaigu Oztibarrekoa eta Garaziko eskualdean luke kiderik hurbilena.
La carta bilingüe de Matxin de Zalba (1416). El iceberg lingüístico navarro
Authors: Monteano Sorbet Peio
Published: March 2021

La carta escrita en romance navarro y en euskera que en 1416 se intercambiaron dos altos funcionarios nos descubre una élite social y política de Navarra que conoce, habla y es capaz de escribir ambas lenguas y que utiliza ese bilingüismo como elemento de poder. Si el euskera no tuvo un uso escrito, no fue por falta de prestigio o por dificultades atribuibles a la propia lengua. La navarrización de la administración y de la corte desde comienzos del siglo XV fue en parte consecuencia del crecimiento demográfico de la población  vascohablante, que pudo rondar el 80 por ciento de los navarros. Todo ello invita a reformular nuestra visión de la situación lingüística de Navarra y de la convivencia de ambas lenguas durante los últimos siglos de la Edad Media, utilizando la documentación, pero siendo conscientes también de sus limitaciones.
Saroi entitate geografikoaren banaketa, esanahia eta etorkia toponimiaren argitan
Authors: Zaldua Etxabe Luis Mari
Published: March 2021

Hona dakargun saioaren helburua saroi entitate geografikoaren banaketaz, esanahiaz nahiz etorkiaz baliagarri gerta daitezkeen argibideak ematea da, euskal toponimian kausitzen diren elementuen izaera finkatzen laguntzea alegia, bide batez, euskararen arlo fonikoaren, morfologiaren edota lexikoaren historia ikertzeko erabilgarriak izan daitezkeen datuak bilduz eta sailkatuz. Saroiak itxuratzen dituzten ezaugarriak, edota haien bilakaera, onomastikaren eskutik zenbateraino ezagut daitezkeen ere ikusi nahi dugu, saroien jatorriak argitzeke baitirau.