bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of chemical structure, antimicrobial, cytotoxic and mechanism of action of Syzygium aromaticum essential oil on foodborne pathogens
Authors: Behbahani Behrooz Alizadeh , Noshad Mohammad , Falah Fereshteh
Published: November 2019

In this study, chemical composition (gas chromatography-mass spectroscopy), chemical structure (fourier transform infrared spectroscopy) and antioxidant potential (β-carotene bleaching assay and DPPH/ABTS-radical scavenging activity tests) of Syzygium aromaticum essential oil (SAEO) were evaluated. Eugenol (75.11%) was found to be the major compound of SAEO. Eugenol, as the main chemical constituent of SAEO, showed its signature peaks in the wavenumber range of 720 – 1250 cm-1, ascribing to the C=C region. The antimicrobial activity of SAEO on Escherichia coli, Staphylococcus aureus, Listeria innocua and Pseudomonas aeruginosa were evaluated. The scanning electron microscopy (SEM) was then applied to unravel the antibacterial mechanism of SAEO on E. coli as the most resistant strain and L. innocua as the most sensitive strain. The MTT assay was also used to investigate the cytotoxicity effect of SAEO on human colonic cancer cell lines (HT29 cell line) and the highest cytotoxic effect was observed at 200 mg.mL-1 concentration of SAEO. The SEM micrographs revealed that the SAEO treatment was able to manifestly increase the cell permeabilization and membrane integrity disruption. This means that the entirety of the cell membranes was remarkably affected by the essential oil, which could lead to cytoplasm secretion and subsequent cell death. The data strongly suggest that SAEO had a potential antioxidant, antimicrobial and cytotoxicity activity.
The amino acid profile after addition of humic acids and phytobiotics into diet of broiler chicken
Authors: Haščí­k Peter , Pavelková Adriana , Tkáčová Jana , Čuboň Juraj , Bobko Marek , Kačániová Miroslava , Arpášová Henrieta , Čech Matej
Published: November 2019

The aim of the study was analysed the effect of humic acids separately and humic acids in combination with phytobiotic as garlic and oregano powder on amino acid (AA) profile of the most valuable parts of Ross 308 chicken. A total of 200 pcs Ross 308 broiler chickens of mixed sex were randomly divided into 4 groups (n=50): control group (C) without supplementation, experiment group E1 (2% humic acids), E2 (80% humic acids and 20% garlic powder) and E3 (90% humic acids and 10% oregano powder). Fattening period lasted for 42 days and all groups were kept under the same conditions. After slaughter, the AA profiles of breast and thigh samples were determined. In comparison with control group, 6 out of 10 AA was significantly affected (p ≤0.05) by used dietary supplementation - Met, Cys and His in thigh and Leu, Phe, His and Arg in breast muscle. AA composition of breast muscle was positively affected mainly by humic acids and 10% oregano powder supplementation (E3), while thigh muscle by humic acids and 20% garlic powder (E2). The highest obtained AA in breast muscle was Leu (2.02 g.100 g-1) in E3 group and thigh muscle His (1.15 g.100 g-1) in E2 group (p ≤0.05). In conclusion, humic acids and 10% oregano powder supplementation (E3) elicited to the best AA profile of chicken breast muscle but also the worst AA profile in thigh muscle so the effect of such a supplementation is disputable. On the other hand, humic acids and 20% garlic powder supplementation resulted into slight increase of AA in both breast and thigh muscle (E2).
Tangible Rewards or Intangible Rewards - Which Play Most Significant Role in Increasing Job-Hopping Behavior in Generation Y Employees in Pakistan?
Authors: Saif Uresha , Siddiqui Danish Ahmed
Published: November 2019

Job hopping in the modern world is one of the major challenges that can be perceived in the current workforce market in Generation Y. The determination of this exploration is to scrutinize among tangible or intangible rewards, which plays most significant role in increasing job-hopping behavior in Generation Y employees in Pakistan. Tangible rewards were factored in 1. Market Competitive Pay, 2. Monetary Benefits and 3. Performance Incentives, whereas intangible rewards include 1. Quality of Work, 2. Work Life Balance, 3. Inspiration & Values, 4. Organization Environment and 5. Future Growth & Opportunity. The data was collected by means of close ended likert scale based questionnaire from 201 employees who belong to different industries in Pakistan. Confirmatory factor analysis & Structured Equation Modelling were used for the examination. The study found that job hopping is optimistically associated with intangible rewards in Gen Y employees & negatively associated with tangible rewards.  This research provides insight to employers which factors must be considered while developing strategies for employees’ compensation and retention in order to retain their competent employees and minimize job hopping behavior in Generation Y employees.
EVIDÊNCIAS DE VALIDADE PARA A ESCALA BAPTISTA DE DEPRESSÃO VERSÃO HOSPITAL-AMBULATÓRIO (EBADEP-HOSP-AMB)
Authors: Da Silva Cremasco Gabriela , Nunes Baptista Makilim
Published: November 2019

O objetivo do estudo foi buscar evidências de validade baseadas na relação com variáveis externas para a Escala Baptista de Depressão Versão Hospital-Ambulatório (EBADEP-HOSP-AMB). Participaram 210 pacientes renais crônicos em hemodiálise, com idades entre 18 e 82 anos (M=53,40; DP=14,40), sendo 112 (53,3%) do sexo masculino. Foram aplicados um questionário sociodemográfico/saúde, juntamente com a EBADEP-HOSP-AMB, a Escala Hospitalar de Ansiedade e Depressão (HADS) e a Escala de Pensamentos Depressivos (EPD). As aplicações ocorreram de forma individual durante as sessões de hemodiálise. Foi verificada a relação entre os instrumentos além de possíveis diferenças de média em função das variáveis sociodemográficas. Os principais resultados indicaram correlações significativas de magnitudes moderadas a altas entre os instrumentos. Também foi observado que as mulheres e aqueles que relataram ter diagnóstico de depressão obtiveram escores mais elevados na maioria das escalas apresentando mais sintomatologia depressiva e pensamentos depressivos, bem como ansiedade.
CONSIDERAÇÕES SOBRE A FORMAÇÃO DO PSICÓLOGO NO BRASIL: REVISÃO SISTEMÁTICA
Authors: Prates Bianca Veiga , Feitosa Ellen Araújo Lima , Monteiro Paulo Souza , Castelo Branco Paulo Coelho
Published: November 2019

Objetivamos analisar o estado corrente de produções sobre a formação do psicólogo nas bases SciELO e PePSIC, segundo uma revisão sistemática de 118 artigos, categorizados conforme ano, periódico, autoria, filiação, região, tipo de pesquisa, método e tema. Os resultados demonstram: aumento de produções nesta década; concentração de publicações na revista Psicologia: Ciência e Profissão; ampla variedade de autores e filiações, com proeminência de produções no sudeste; preponderância de metodologias empíricas que usam análise documental; prevalência de temáticas relacionadas à formação acadêmico-científica. Indicamos que existe uma dispersão sobre o que seria formação do psicólogo. Há muitos estudiosos que fazem incursões pontuais sobre o tema. Necessita-se de mais discussões sobre a formação nos interiores brasileiros, que atualmente concentram a maioria de alunos matriculados. Concluímos com um questionamento sobre as diferenças formativas de um psicólogo graduado na capital daquele educado em uma instituição interiorizada.
A arquitetura e a cidade no jogo fotográfico
Authors: Vieira César Bastos de Mattos
Published: November 2019

Se, inicialmente, a fotografia tirou proveito da arquitetura e da cidade, como modelos para provar a capacidade do aparato tecnológico de ser capaz de registrar de forma direta uma determinada cena, depois, tornou-se uma das principais ferramentas de apresentação e apreensão, no campo da arquitetura e do urbanismo. Entretanto, de certo modo, parece não serem estudadas as consequências das demandas fundamentais da fotografia – distância, luz e ordenamento – e os programas inseridos dentro do equipamento na alteração e/ou limitação do registro fotográfico. Este trabalho busca problematizar de que maneira este “jogo fotográfico” altera e, porque não especular?, direciona no sentido da construção de um imaginário limitado da “realidade” de edificações e cidades, onde o que não é passível de ser fotografado não existe.
SHIP SAFETY AT HAZARDOUS SITUATIONS ON EXAMPLES OF ANTI-DEFECT PROTECTION SIMULATOR
Authors: Haberek Roman , Chmieliński Mirosław , Pietrukaniec Leszek
Published: November 2019

The paper presents a deployment of a simulator of Ship Anti-defect Protection (SAP) as a modern method of training the crews of service ships of the Polish Navy on anti-defect countermeasures. Ship’s safety is a complex question of many aspects. For instance, making the proper decisions and following the binding rules depends on the sea experience and training, whereas the process of training takes place both at sea cruises and at training centres. The paper deals with the questions of warship’s safety when a fire starts in various places of the ship. Identification of defects and their types, and methods and tools for their repair are described. The SAP simulator was built by using modern computer technologies and a large projection screen being a section of a cylindrical surface.
Doublings
Authors: Therezo Rodrigo ,   Philosophy Documentation Center
Published: November 2019

This article attempts to read the very concept of reading as articulated and problematized by Derrida’s newly discovered Geschlecht III. I argue that Derrida enacts a reading of Heidegger in Geschlecht III in ways that help us understand the strong sense Derrida gives this word. In the article’s first part, I dwell on Derrida’s—and Heidegger’s—(quasi)methodological precautions that problematize the traditional concept of reading so as to open the way for a reading of Heidegger that does not bank on the metaphysical presuppositions the very same Heidegger warns us against time and again. In the second part, I turn to Derrida’s topotypological examples that show us what traditional methodology problematically presupposes when “reading” Heidegger. The article ends by turning to the Derridean notion of “overprinting”—and the uncanny effects of doubling it implies—as a way to think about what it means to read and countersign Heidegger’s text.
Estudio sobre el patrimonio de la ciudad de Lorca en educación primaria
Authors: Martínez de Miguel López Silvia , Salmerón Aroca Juan Antonio , Serrano Ruiz María Luz
Published: November 2019

Resumen: El objetivo de este trabajo es analizar el nivel de conocimientos, que posee el alumnado de educación primaria de Lorca (Murcia), acerca de los bienes culturales de la ciudad después del seísmo que asoló a la ciudad en 2011. En el marco de un diseño de investigación no experimental, de tipo exploratorio, se empleó un cuestionario creado ad hoc, que fue aplicado a 156 escolares de educación primaria. Los resultados del estudio muestran una evidente capacidad de mejora respecto al nivel de conocimiento y grado de frecuentación del alumnado al patrimonio histórico artístico. Se concluye que, a pesar de más de un lustro de rehabilitación del patrimonio lorquino, sin embargo, el conocimiento por parte del alumnado es todavía escaso frente a sus posibilidades pedagógicas, siendo necesario promover e incrementar su frecuentación, difusión, divulgación y conocimiento desde la escuela.Abstract: The objective of this work is to analyze the level of knowledge of primary education students about the cultural and museum heritage, after having suffered the earthquake that devastated the city on 2011. A non-experimental research design, of an exploratory type, was used an ad hoc questionnaire, which was applied to 156 primary school students. The results of the study show an evident improvement in the level of knowledge and degree of attendance of the local cultural heritage.  It is concluded that, despite after more than a few years of rehabilitation of the lorquino heritage, however, the knowledge of the students is still low compared to their pedagogical possibilities, being necessary to promote and to increase their frequency, dissemination, dissemination and knowledge from school.
El arte digital y su relación con la violencia de género
Authors: Segura-Mariño Adriana Graciela , García-Umaña Andrés
Published: November 2019

Resumen: Los medios digitales permiten una comunicación más directa que los tradicionales. Los activistas pueden optimizar su labor al encontrar nuevas formas de difundir mensajes, construidos en formatos audiovisuales con un componente estratégico para contrarrestar problemas sociales, como la violencia de género. Con esta investigación se pretende determinar si el arte digital es una herramienta persuasiva contra este problema en el entorno online. Esto se resolvió a través de dos etapas: la primera consta de una revisión bibliográfica; la segunda consiste en el análisis de contenidos sobre el desarrollo de las acciones online de artivistas que luchan contra la violencia de género, y sobre los proyectos influyentes (según ONU Mujeres y el Festival Iberoamericano de la Publicidad – FIAP) que se han realizado en distintos contextos geográficos, identificando su difusión en plataformas de comunicación, los formatos, contenidos, audiencia y engagement. Se detectó que no se aprovecha estratégicamente la comunicación 2.0; los pocos artivistas que tienen presencia en Internet se limitan a convocar a acciones offline; si bien los proyectos influyentes rompen estereotipos y promueven la participación de la audiencia, no se dirigen a los adolescentes, que son quienes más utilizan Internet. El trabajo multidisciplinario es clave para diseñar soportes altamente visuales y persuasivos.Abstract: Digital media allow a more direct communication than traditional media. Activists can optimize their work finding new ways to spread messages, which are built in audiovisual formats with a strategic component to counteract social problems, such as gender violence. The objective of this research is to determine if digital art is a persuasive tool against this problem in the online environment. This was resolved through two stages: the first one consists of a bibliographic review; the second one consists of a content analysis on the development of online actions by artivists who work against violence of gender, and on the influential projects (according to UN Women and the Ibero-American Advertising Festival - FIAP) that have been carried out in different geographical contexts, identifying their diffusion in communication platforms, the formats, contents, audience and engagement. It was detected that 2.0 communication is not used strategically; the few artivists with presence on the Internet only call for offline actions; Although influential projects break stereotypes and promote audience participation, they do not target adolescents, the ones who most use the Internet. Multidisciplinary work is key to designing highly visual and persuasive supports.
Diálogos desde los estudios eidéticos: disposiciones, complejidades y temas pendientes
Authors: Díaz Herrera Claudio
Published: November 2019

Reseña de la obra/ Book Review: Devés, Eduardo y Kozel, Andrés (2018). Estudios eidéticos. Una conversación desde el Sur sobre la vida de las ideas y la reconfiguración de un espacio disciplinar. Santiago de Chile: Ariadna ediciones, 315 p. ISBN: 978-956-393-532-5
Juan Carlos Barroso (1925-1995): un testimonio de la renovación artística de postguerra
Authors: D' Agosto Forteza Sonia
Published: November 2019

Resumen: En las primeras décadas de la Postguerra española muchos artistas de capitales de provincia intentaron renovar sus propios ambientes culturales. Algunos de ellos fueron artistas menores que el tiempo ha olvidado, como es el caso del pintor jerezano, Juan Carlos Barroso Jiménez. En este artículo vamos a rescatar su trayectoria vital y artística a través del estudio de sus obras, con la intención de introducirnos en los distintos lenguajes estéticos que empleó, entre ellos, las interpretaciones del clasicismo pictórico, el cubismo de corte cezaniano heredado de Vázquez Díaz y el fauvismo transmitido por los pintores de la Segunda Escuela de Vallecas.Abstract: In the first decades of the Spanish Postwar period, many artists from provincial towns tried to restart their cultural environments. Some of them were minor artists that time had forgotten, as is the case of the painter from Jerez, Juan Carlos Barroso Jiménez. In this article we will try to rescue his personal and artistic trajectory by studying his works, with the intention of learning the different aesthetic languages that he used. Among them, the interpretations of pictorial classicism, the Cezanian cubism inherited from Vázquez Díaz and the fauvism inherited from by the painters of the Second School of Vallecas.
Teatro de animação na escola: procedimentos e reflexões
Authors: Rodrigues Eder Sumariva
Published: November 2019

Tem-se por objetivo neste artigo a apresentação de reflexões pedagógicas desenvolvidas com as linguagens do Teatro de Animação em escolas da rede municipal de ensino de Florianópolis/SC com alunos do quinto ao nono ano. Estas experiências pedagógicas que incluem o Teatro de Sombras e o Teatro de Máscaras ocorreram entre 2016 e 2018 na rede municipal de ensino de Florianópolis. Na primeira parte desse texto, descrevo os procedimentos pedagógicos utilizados durante as aulas de artes cê- nicas e, no segundo momento, reflexões acerca da ausência/presença e da importância do Teatro de Animação na escola. Palavras-chave: Pedagogia. Teatro de Máscaras. Teatro de Sombras. Teatro de Animação. Escola.
BIOMIMETIC APPROACHES TO STUDY OF PROPERTIES OF MEDICINAL SUBSTANCES
Authors: Melnikova Nina B. , Solovyova Olga N. , Evgeni N. Kochetkov Evgeni N.
Published: November 2019

The review is devoted to an assessment of the current level of use of biomimetic approaches to the study of the properties of known drugs and the development of new drugs. In this review, we consider the main biological functions of superoxide dismutase, namely the catalytic decomposition of toxic superoxide anion of oxygen to the molecular form of oxygen and protection against induced apoptosis. The biomimetic enzymes-Mn- and TEMPO-containing equivalents of superoxide dismutase SOD with antitumor and antioxidant activity were discussed more detail. The relationship between the properties and activity of SOD mimetics with their structure among them the nature of the anion and ligands, the coordination number, the geometry of the presence of conjugated bonds, and other parameters of the molecules. The study of the properties of Mn-SOD mimetics makes it possible to develop a new class of drugs successfully tested by in vivo and in vitro experiments and which are at the stages of clinical trials. Stable TEMPO radicals containing compounds are able to perform SOD functions, exhibiting antioxidant activity in relation not only to superoxide-anion, but also to peroxynitrile, and moreover to act as a spin label. The biomimetic membrane systems (monolayers, planar lipid bilayers, liposomes and other nano-sized objects) are discussed too for studying properties in in vitro experiments and for delivering potent and medicinal substances. The biomimetic approach combination allows to create the new promising drugs, including those based on SOD mimetics, and to develop the synthetic analogues of biologically active substances and methods of their delivery. The advantages of such dosage forms are lower toxicity of the preparations, lack of immunogenicity and a decrease in the dose of potent drugs.
EXTRACTION METHODS OF CLEANING OF MOTOR FUEL
Authors: Seidova Sabina A.
Published: November 2019

In paper the results of the carried out analysis of literary data on preparation of motor fuels of high quality by extraction method of purification of the corresponding oil distillates with use of compounds of various class as a selective solvent have been presented. In particular, the results of comparative analysis of existing methods of the extraction purification of distillates of motor fuels from unnecessary components – aromatic hydrocarbons, sulphur-containing compounds and resinous substances with use of organic solvents and ion-liquid compositions as a selective solvent have been presented. The advantage of the extraction method of purification of motor fuels determined by possibility of the process at low temperature and pressure, by absence of necessity of application of the expensive catalysts, by possibility of regeneration and reuse of solvent, etc. in comparison with widely used hydrogenation method has been shown. The lacks of the organic solvents used as an extractant have been also listed and due to the ecological problems the use of non-volatile, thermally stable ion-liquid compositions as a selective solvent in the processes of purification of the distillates, intended for preparation a high quality target products, such as diesel fuel, gasoline, base oils for various purposes has been substantiated. In paper the results of systematic investigations carried out at the Institute of Petrochemical Processes of Azerbaijan National Academy of Sciences with the participation of the authors themselves, concerning the selective purification of the oil fractions of various composition and viscosity with use of ionic liquids synthesized on the basis of formic and acetic acids composition have been also presented. By carried out analysis it has been shown the perspectivity of application of the ion-liquid compositions as an extractant in the processes of the selective purification of the oil distillates.
METHOD OF EVALUATING CHANGES IN TEMPERATURE AND MOISTURE CONTENT USING ELECTROMAGNETIC DRYING OF SAMPLE OF ARBITRARY SHAPE
Authors: Afanasiev Anatoly M. , Popov Gleb. A. , Siplivy Boris N.
Published: November 2019

Analytical methods were used to study the process of removing moisture from the sample of arbitrary shape, located in the working chamber of the installation for drying by electromagnetic waves. The sample is blown by the air flow and exposed to two types of radiation, having a large and, accordingly, small compared to the size of the sample penetration depth. To increase the uniformity of blowing and heat treatment, the sample is rotated. The equations of heat and mass transfer theory are used as a mathematical model of drying Lykov in a medium with constant thermal coefficients. Using transformations of three types - averaging over turnaround time, averaging over coordinates, and transition to time asymptotics - the original equations are reduced to a form that contains only numerical characteristics of functions.  On the basis of these relations, formulas for the values called characteristic temperature and moisture content differences, which characterize the degree of heterogeneity of the corresponding fields, are proposed. The introduced differences depend on the thermophysical parameters of the material, the typical size of the sample (for the ball – diameter), as well as on the power of generators of electromagnetic waves with a large and small penetration depth. In the case of a ball, the characteristic differences give the exact values of the temperature difference and the moisture content difference between the surface of the ball and its center. The results of the work allow to organize electromagnetic drying, in which at a high intensity of moisture evaporation from the surface of the sample there is no overheating of the material (due to a large temperature drop) or its destruction from mechanical deformations (due to a large difference in moisture content).
POLYMERIC COMPOSITION FOR PURIFICATION OF WASTEWATER FROM VARIOUS IMPURITIES IN TEXTILE INDUSTRY
Authors: Amonova Matluba M. , Ravshanov Kazokmurod A.
Published: November 2019

This article deals with the development of new and improvement of traditional methods of wastewater treatment of dyening and finishing industries. The composition was developed on the basis of local natural minerals (bentonite Navahermosa origin, sodium bisulfite, polyacrylamide and aluminium sulphate) for the treatment of wastewater of the textile industry. The influence of bentonite particle size on the degree of wastewater discoloration at different flow rates was studied. With a range of wastewater supply flow rates from 0.5 to 2.0 m/s with a particle size of bentonite adsorbent in the range of 0.25-1.0 nm, the maximum degree of wastewater bleaching is achieved and it is in the range of 84-87%. For microporous adsorbents (CAD-100 and CAD-200) the effectiveness of the discoloration also does not depend on the particle size and ranges from 85 to 87 %.  It was found that, for fine-pored adsorbents (BKA-100 and BKA-200), the efficiency of discoloration also practically does not depend on the particle size and ranges from 85 to 87 %. The highest degree of wastewater treatment according to the proposed composition, apparently due to the fact that in the adsorption process, in addition to the sorption of sewage impurities on the surface of adsorbents, there is a sorption of ions and molecules of dissolved substances on the surfaces of air bubbles and their removal in the foam layer. The wastewater treatment parameters of the dyeing and finishing shop using the bentonite composite adsorbent show that the degree of removal of contaminants by the method developed by us is much higher compared to the sedimentation of aluminum or iron oxyhydrates with adsorbed contaminants. Moreover, the effects of reducing the value of COD and concentration of the surfactant in the wastewater was, on average, 65 % and 82 %, and compared to the effects of reducing the same parameters at defending precipitation of oxyhydrates at 48-54 % and 54-61 %, respectively.
INFLUENCE OF LIQUID-PHASE OXIDATIVE TREATMENTS ON STRUCTURE AND HYDROPHILITY OF CARBON NANOTUBES
Authors: Tabulina Lyudmila V. , Komissarov Ivan V. , Rusalskaya Tamara G. , Shulitsky Boris G. , Shaman Yuri P. , Bazarova Marina I.
Published: November 2019

Carbon nanotubes (CNTs) were synthesized by gas phase chemical deposition (CVD) using methane as a hydrocarbon reagent and using a catalyst of iron oxide deposited on fine aluminum oxide, as well as the same catalyst with the addition of molybdenum oxide deposited on fine magnesium oxide. The synthesized materials were treated with concentrated nitric acid (HNO3) or a mixture of concentrated nitric and sulfuric acids (HNO3 / H2SO4) in a volume ratio of 2: 1, at a temperature of 110-120 ° C for 1 h. Some of them were subjected to peroxide action (H2O2) before oxidative acid treatments for 1-2 h at a temperature of 100-110 ° C. Structural features, elemental compositions of synthesized CNTs were investigated before and after liquid-phase oxidative treatments by methods such as transmission electron microscopy, Raman spectroscopy, X-ray energy dispersive spectroscopy, X-ray phase analysis. In this work, the ability of CNTs that were undergone treatment in various oxidizing environments to form stable concentrated aqueous suspensions was studied. It was established that the initial defectity of the CNT molecules significantly affects the hydrophilic properties of oxidized CNT modifications. This causes their different ability to form concentrated, stable aqueous suspensions, predetermines the choice of combinations of oxidizing liquid-phase treatments that most contributing to this. It was revealed that HNO3 and HNO3 / H2SO4 mixture at the used temperature conditions of treatments and their duration do not have a strong destructive effect on the structure of CNT. The oxidative effect of these reagents on the molecules of this material is manifested mainly in defective places. The cleaning of the catalytic components of the synthesis from the catalytic components contributes to the more efficient purification of HNO3 / H2SO4 with the formation of stable aqueous suspensions from the molecules of this material, and this does not depend on the characteristics of the synthesis of the CNTs.
MORPHOLOGICAL FEATURES AND WETTABILITY OF POLYTETRAFLUOROETHYLENE SURFACE TEXTURED BY LASER ABLATION
Authors: Vitrik Oleg B. , Kulchin Yuriy N. , Egorkin Vladimir S. , Sinebryukhov Sergey L. , Gnedenkov Sergey V.
Published: November 2019

In this paper, the morphological features of textures with non-uniform wettability created using femtosecond laser ablation of polytetrafluoroethylene substrates have been studied. Covering the surface of polytetrafluoroethylene with microcraters in accordance with a proper design a texture in the form of periodically located microcollets could be created. The period of the location of the columns is the same over the entire surface and is selected in the range from 15 to 100 microns. In the case when the period lies within 30–100 µm, the diameter of the bars is ~ 20 µm. If in the range of 15–20 µm, then this diameter decreases accordingly to ~ 10 µm. Depending on the pulse energy, the height of the pillars could be smoothly changed from 0 to 60 μm. However, to create a superhydrophobic concentrator, textures with the greatest depth were used so that the height of the columns does not limit the stability of the superhydrophobic state by the sagging mechanism. It was established that on the surface of each pillar during the process of laser ablation, a relief with a two-modal roughness in the form of short drop-shaped projections of the material covered with spherical globules is additionally formed. Thus, in one stage of laser micromachining, it is possible to create a surface with a three-modal roughness – microcolumns, drop-shaped projections and spherical globules. The process of droplet evaporation is represented by two main modes of constant contact angle and constant contact diameter, when the latter ceases to decrease and remains constant until the complete evaporation of the drop. As a result, a precipitate of the substance dissolved in a drop is formed on the substrate. It has been established that in the interval 0 <τ <0.9, evaporation occurs in the constant contact angle mode.
MODELING PROCESS OF DESTRUCTION OF PARTICLES OF CEMENT AT INITIAL STAGE OF HYDRATION
Authors: Filimonova Olga N. , Enyutina Marina V. , Khvostov Anatoly A. , Ryashskih Viktor I.
Published: November 2019

The substantiation the existence of the destruction period of cement particles during the hydration of concrete into fragments, in size significantly larger than the average size of molecules is presented. An idealized structure of the cell representation for the cement grain and the water surrounding it in the form of nested spheres is adopted. The outer sphere does not change its coordinates, and the inner sphere imitating the cement grain decreases in the course of the process due to the transfer of the formed fragments into the inter-spherical space filled with water. The assumption is made that the concentration field is uniform and varies along the radius. The crushing process is described using a physical model of "pseudo-dissolution" and is based on the formulation of Fick's law. By introducing the rate of destruction associated with the movement of the interfacial boundary, a mathematical model is formulated in the form of an initial boundary value problem for the diffusion-type equation in a spherical coordinate system. By introducing a special coordinate system, the formulated initial-boundary value problem is transformed into a problem with fixed boundaries. Integration of the obtained system is performed numerically using an explicit finite-difference scheme. The computational experiment confirmed the efficiency of the proposed algorithm, which allowed to conduct a qualitative analysis of the model, which showed the correctness of the assumptions made in the formulation of the mathematical model. It is found that in a spherical cell containing an average cement grain, the fragments are localized near the interfacial surface due to the weak influence of the diffusion transfer mechanism. The estimation of the average size of the fragments, which are significantly larger than the average molecular size, further confirmed the hypothesis of the existence of the period of destruction of cement grains in the initial stage of concrete hydration.
First confirmation of the shell-boring oyster parasite Polydora websteri (Polychaeta: Spionidae) in Washington State, USA
Authors: Martinelli Julieta , Lopes Heather , Hauser Lorenz , Jimenez-Hidalgo Isadora , King Teri L , Padilla-Gamino Jacqueline , Rawson Paul , Spencer Laura , Williams Jason , Wood Chelsea
Published: November 2019

Invasions by the spionid polychaete Polydora websteri have resulted in the collapse of oyster aquaculture industries in Australia, New Zealand, and Hawaii. These worms burrow into the shells of bivalves, creating unsightly mud blisters that are unappealing to consumers and, when nicked during shucking, release mud and detritus that can foul oyster meats. Recent sightings of mud blisters on the shells of Pacific oysters (Crassostrea gigas) in Puget Sound, Washington, suggest a new spionid polychaete invasion. To determine the identity of the polychaete causing these mud blisters, we obtained Pacific oysters from two locations in Puget Sound and examined them for blisters and burrows associated with spionid infection. We then extracted polychaetes and sequenced mitochondrial (cytochrome c oxidase I [COI]) and nuclear (18S rRNA) genes to obtain species-level identifications for a subset of these worms. Our data confirm that P. websteri is present in mud blisters of Puget Sound oysters, constituting the first confirmed record of this species in Washington State. The presence of non-native P. websteri could threaten the sustainability of oyster aquaculture in Washington, which currently produces more shellfish than any other US state.
Persistent Mycobacterium tuberculosis infection in mice requires PerM for successful cell division
Authors: Wang Ruojun , Kreutzfeldt Kaj , Botella Helene , Vaubourgeix Julien , Schnappinger Dirk , Ehrt Sabine
Published: November 2019

The ability of Mycobacterium tuberculosis (Mtb) to persist in its host is central to the pathogenesis of tuberculosis, yet the underlying mechanisms remain incompletely defined. PerM, an integral membrane protein, is required for persistence of Mtb in mice. Here, we show that perM deletion caused a cell division defect specifically during the chronic phase of mouse infection, but did not affect Mtb’s cell replication during acute infection. We further demonstrate that PerM is required for cell division in chronically infected mice and in vitro under host-relevant stresses because it is part of the mycobacterial divisome and stabilizes the essential divisome protein FtsB. These data highlight the importance of sustained cell division for Mtb persistence, define condition-specific requirements for cell division and reveal that survival of Mtb during chronic infection depends on a persistence divisome.
A Review on Common Methods for Characterizing Graphene Oxide (GO)
Authors: Shafiul Islam Md.
Published: November 2019

Graphene oxide, two-dimensional material with the thickness of 1.1±0.2 nm, has gained attention to a greater extent in the field of science for its radically distinctive properties: physical, chemical, optical as well as electrical etc. Graphene oxide (monolayer sheet) has been synthesized by oxidizing graphite (millions of layer) to graphite oxide (multilayers) which has been converted into graphene oxide via exfoliation followed by sonication and centrifugation - a method mentioned as Modified Hummer Method. I focus on the chemical structure of graphene oxide. However, I discuss the different analytical methods such as UV-Visible spectroscopy, Atomic Force Microscopy (AFM), X-ray Photoelectron Spectroscopy (XPS), Fourier Transform Infrared Spectroscopy (FTIR) as well as X-ray Diffraction pattern for characterizing the graphene oxide. Furthermore, this review covers the analytical evaluation of graphene oxide and discuss the past, present and future of graphene oxide in the scientific world.
Corporate Governance Dimensions and Organizational Performance: A Pragmatic Investigation from Nigerian Banks
Authors: Olabamiji Ogunlade
Published: November 2019

This study seeks to examine the impact of corporate governance dimensions on organization Performance with specific reference to the Nigerian Banking Industry. Data were sourced via the audited financial statements of the selected bank for a period of five years between 2013 and 2018. Data analysis was performed with the aid of multiple regression analysis and Pearson Product Moment Correlation Coefficient. The result establishes that positive relationship exists between Board independence and organizational performance measured by earnings per share and return on equity. The result further affirms that Board size and Chief executive duality have an inverse effect on organizational performance measured by earnings per share and return on equity. The implication of this that the abolition of Chief executive duality and small Board size would save guide the shareholder interest and enhances effective monitoring and control. Thus, it will attract both foreign and local investors to invest in the banking sector in Nigeria.
Improvements of Crop Production through Integrated Soil Fertility Management in Ethiopia
Authors: Wato Tamirat
Published: November 2019

Agriculture plays a central role within the Ethiopian economy. In our country, concerning 85% of total population depends on agriculture and its product. This implies agriculture provides a good portion of national product growth. In spite of the importance of this sector, production and productivity area units restricted by varied biophysical, social and economic aspects. Soil fertility decline is one of the central issues that scale back Ethiopian agriculture and at last, it ends up in poverty and starvation. The main causes of those entrenched challenges are the land degradation showed in type of soil fertility decline, as introduced by varied hindrances as deforestation, overgrazing and through a consequence of wearing away, deposit, pollution, etc. Hence, the core objectives of this review are to evaluate the soil fertility status in Ethiopia, the sources of soil fertility decline and find improved resolutions to soil fertility in Ethiopia. As the physiological factors of the country are rugged with dynamical sorts of soils, preponderantly the upland wherever regarding 90% of the tillable land is concentrated, difficulties such as soil erosion, meager and incessant cultivation are the chief reasons of soil fertility loss. Thus, the application of combined soil fertility management approach with presence and mixture of manure, compost, crop rotation, soil protection practices provides improved production and saves the soil fertility standing to an improved level. The apply undertaken by the government of Ethiopia, is that the application of optimum rate of fertilizers, but it's not thriving as a results of various factors like amendment of agroecology, edaphic factors, the social and economic state of affairs of the farmer, repair to property combined soil fertility management to get high yield while not compromising the soil fertility position within the future, this can be broad and needed to be followed.
Blood–Brain Barrier
Authors: Peterson Darryl R
Published: November 2019

The blood–brain barrier consists of specialised endothelial cells primarily lining brain capillaries. It serves to restrict and control the movement of substances between the general circulation and brain extracellular fluid. It participates in regulating the volume and composition of fluid within and surrounding the central nervous system through specific transport processes and thus contributes to its homoeostasis. Some of these processes may be regulated hormonally or modulated by adjacent cells including astrocytes and pericytes. The barrier function of the blood–brain barrier is due to (1) tight junctions that restrict the movement of substances between the endothelial cells, (2) specific transport proteins that determine which substances can cross the barrier transcellularly and (3) enzymes that may degrade or alter substances prior to passage. Systemically administered drugs intended to treat neurological disorders must be designed to bypass the restrictive elements of the blood–brain barrier. Pathological conditions associated with the central nervous system may alter blood–brain barrier function.

Key Concepts

The blood–brain barrier regulates brain extracellular fluid.

Brain capillaries form a tight barrier except in specialised areas.

Tight junctions restrict paracellular movement of substances across the blood–brain barrier.

Astrocytes and pericytes contribute to differentiation and function of the blood–brain barrier.

Transport across the blood–brain barrier may be passive or active.

Enzymes contribute a metabolic barrier to the blood–brain barrier.

Delivery of drugs to the brain requires a strategy to by‐pass the blood–brain barrier.

Blood–brain barrier function may be altered in the context of neurological disorders.
Microstructural Evolution and Mechanical Behavior of Cu/Nb Multilayer Composites Processed by Accumulative Roll Bonding
Authors: Ding Chaogang , Xu Jie , Li Xuewen , Shan Debin , Guo Bin , Langdon Terence G.
Published: November 2019

Cu/Nb multilayer composites with minimum individual layer thicknesses of ≈2.8 μm are achieved by accumulative roll bonding (ARB). The microstructural evolution and mechanical properties of these composites are investigated with different layer thicknesses after ARB processing. The results show that there is no visible interfacial reaction between the Cu and Nb layers, and the kernel average misorientation (KAM) distributions in electron backscatter diffraction (EBSD) maps remain in steady state during the third to seventh ARB cycles. The tensile testing results demonstrate that the yield strength increases with decreasing layer thickness in Cu/Nb multilayer composites. A simultaneous increase of strength and elongation is achieved by regulating the laminated structures. Microstructure and fracture analysis indicate that the simultaneous increase of strength and elongation is attributable to the high density of bimetal interfaces, which act as a barrier for dislocation mobility and crack propagation.
The Bright X‐Ray Stimulated Luminescence of HfO2 Nanocrystals Activated by Ti Ions
Authors: Villa Irene , Moretti Federico , Fasoli Mauro , Rossi Antonella , Hattendorf Bodo , Dujardin Christophe , Niederberger Markus , Vedda Anna , Lauria Alessandro
Published: November 2019

The recent trends in scintillator technologies stimulate research efforts toward the development of novel materials morphologies, such as nanoparticles, able to efficiently convert ionizing radiations into light. For example, scintillating nanoparticles attract great interest in medical oncological therapies. In this work, the structural and morphological properties of HfO2:Ti nanoparticles with Ti concentrations from 0.03 to 10 mol% and subjected to calcination up to 1000 °C are thoroughly characterized; moreover, X‐ray photoelectron spectroscopy reveals the incorporation of Ti in both Ti (III) and Ti (IV) chemical states in as prepared samples, while the exclusive presence of Ti(IV) is unambiguously identified in calcined nanoparticles. The optical emission under X‐ray excitation evidences an intense Ti (IV)‐related luminescence at 2.5 eV in high temperature calcined samples with a few microseconds scintillation lifetime, and efficiency comparable to that of Bi4Ge3O12 reference scintillator. Finally, the competitive role of defects in charge carriers capture is demonstrated by the monotonic increase of the 2.5 eV band during prolonged X‐ray irradiation, more evident for nanoparticles with titanium concentration below 1 mol%. HfO2:Ti may also find application in X‐ray triggered oncological therapies by using the Ti (IV)‐related bright radioluminescence to excite photosensitizer molecules for singlet oxygen generation.
Es ist im Kleingedruckten: Löschbare dreidimensionale lasergedruckte Mikro‐ und Nanostrukturen
Authors: Gräfe David , Walden Sarah L. , Blinco James , Wegener Martin , Blasco Eva , Barner‐Kowollik Christopher
Published: November 2019

Der 3D‐Druck in allen Dimensionen ist in der Wissenschaft‐ und Industrieforschung derzeit ein dynamisches Thema, da er ein enormes Potenzial hat, die Fertigungsindustrie radikal zu verändern. Wegen der dem Fertigungsprozess innewohnenden Besonderheit erfordern 3D‐Druckstrukturen häufig zusätzliches Trägermaterial, um komplexe Merkmale strukturell zu unterstützen. Dieses Trägermaterial muss nach dem Druck – manchmal auch subtraktive Fertigung genannt – entfernt werden, ohne die verbleibende Struktur zu beeinträchtigen. Eine elegante Lösung für dieses Problem ist der Einsatz von Photolacken mit labilen Bindungen, die eine kontrollierte Spaltung mit spezifischen Auslösern nach dem Druck ermöglichen. In diesem Kurzaufsatz diskutieren wir Design, Auflösung, Spaltungseigenschaften und aktuelle Einschränkungen ausgewählter Beispiele. Darüber hinaus teilen wir unsere Sichtweise auf mögliche labile Bindungen und den entsprechenden Spaltauslöser mit, von denen wir glauben, dass sie vielversprechendes Potenzial für zukünftige Anwendungen haben und das Repertoire der verfügbaren spaltbaren Photolacke sinnvoll erweitern werden.
Asymmetric Synthesis of a Fused Tricyclic Hydronaphthofuran Scaffold by Desymmetric [2+2+2] Cycloaddition
Authors: Teng Qi , Mao Wenxiu , Chen Dong , Wang Zhen , Tung Chen‐Ho , Xu Zhenghu
Published: November 2019

A rhodium(I)‐BINAP‐catalyzed highly enantioselective [2+2+2] cycloaddition of enynes with alkynes has been developed. Diverse fused tricyclic hydronaphthofuran scaffolds with three consecutive stereogenic centers were constructed in one step from easily available materials with excellent chemo‐, regio‐, diastereo‐, and enantioselectivity. Notable features of these reactions include 100 % atom economy, very broad scope, and mild reaction conditions.
Lichtgesteuerte Polymerisation von Dopamin auf DNA‐Origami im Nanometer‐Regime
Authors: Winterwerber Pia , Harvey Sean , Ng David Y. W. , Weil Tanja
Published: November 2019

Durch die Installation eines strahlungssensitiven Polymerisationssystems auf DNA‐Origami kann eine zeitliche und räumliche Kontrolle über die Bildung von Polydopamin im Nanobereich erreicht werden. Präzise angeordnete G‐Quadruplex Strukturen auf dem DNA‐Origami‐Templat fungieren als Ankerpunkte für die Einlagerung des Photosensibilisators Protoporphyrin IX. Die Bestrahlung mit sichtbarem Licht induziert die mehrstufige Oxidation von Dopamin zu Polydopamin, welche zu polymeren Ablagerungen an vordefinierten Positionen des Origami‐Gerüsts führt. Die photochemische Natur dieses Prozesses gewährt eine exklusive Steuerbarkeit der Polydopamin‐Bildung, da die Lichtquelle einfach an‐ und ausgeschaltet werden kann. Das so erhaltene Polymer‐DNA‐Hybridmaterial weist eine signifikant erhöhte Stabilität im Vergleich zum Ausgangsmaterial auf und ebnet damit den Weg für biomedizinische und chemische Anwendungen, die im Allgemeinen durch die Instabilität von DNA limitiert sind.
Eine unerwartete transanulare [4+2]‐Cycloaddition während der Gesamtsynthese von (+)‐Norcembren 5
Authors: Breunig Michael , Yuan Po , Gaich Tanja
Published: November 2019

Eine enantioselektive Totalsynthese des Diterpenoids (+)‐Norcembren 5 ausgehend von einfachen, gut zugänglichen Bausteinen wird berichtet. Schlüsselschritte unserer Synthese sind eine Ringschluss‐Metathese und eine Auxiliar‐basierte enantioselektive 1,4‐Addition. Im Zuge dieser Synthese wurde ein hochoxygeniertes pentacyclisches Ringsystem etabliert, das in einer spontanen transannularen [4+2]‐Cycloaddition gebildet wurde.