bluuebunny/crossref_metadata_2025 huggingface dataset:
Um estudo sobre influenciadores digitais: comportamento digital e identidade em torno de marcas de moda e beleza em redes sociais online
Authors: Grieger Jenifer Daiane , Botelho-Francisco Rodrigo Eduardo
Published: June 2019

Este projeto se propõe a estudar os influenciadores digitais, identificando e descrevendo como se dá a construção identitária em torno de marcas do segmento de moda e beleza brasileiras na Internet promovidas por influenciadores digitais. Os influenciadores digitais usam seus perfis para conversar com seu público sobre pautas cotidianas, o que inclui hábitos de consumo, comportamentos, estilo de vida etc. Propondo um estudo exploratório, utilizando como instrumento a netnografia, que trata das mediações tecnológicas adotadas no contexto social e transpostas para os ambientes digitais em rede aos procedimentos clássicos da pesquisa, o estudo tem objetivo de: 1) compreender a configuração atual do mercado de influenciadores de redes sociais online no segmento de moda e beleza no Brasil; 2) investigar o comportamento digital de influenciadores digitais e seus seguidores; 3) analisar as interações entre seguidores e influenciadores digitais; 4) identificar e caracterizar elementos de construção identitária em torno de marcas a partir das interações entre influenciadores e outros atores sociais na rede.
VELOCITY-BASED MODELING OF THE THERMAL LOAD FOR A FORMULA SAE’S DISK BRAKE SIMULATION
Authors: Redin M. C. , Bez L. F. , Rodrigues L. J.
Published: June 2019

This paper proposes a methodology for the estimation of a disk brake’s thermal load based on its vehicle’s velocity, where this thermal load serves as an input for a numerical simulation. The load is estimated through a balance between variation in the mechanical energy of the vehicle and the energy dissipated via aerodynamic and rolling drag forces. The RS Racing UFRGS team provided the vehicle’s data and geometry, and the velocity data was taken from a real endurance competition. The thermal load thus calculated is then used as input for a 3D transient finite element model containing the disk and the wheel hub. The results are consistent with what is expected by the RS Racing UFRGS team. Based on the results of the 3D transient model, two more simplified analysis are viable: one in permanent regime, which achieves a temperature distribution within the oscillation presented on the transient model; and also a 2D analysis which can be made by the replacement of the wheel hub with an equivalent global heat transfer coefficient.
TEMPORAL VARIABILITY OF LONGITUDINAL SEDIMENT TRANSPORT ON THE BRAZILIAN CONTINENTAL SHELF
Authors: Trombetta T. B. , Marques W. C. , Oleinik P. H. , Guimarães R. C. , Leal T. F. , Bendô A. R. , Lopes B. V. , Kirinus E. P.
Published: June 2019

The sediment transported along the coast can alter the existing balance in certain environments, causing or accelerating erosive processes, and resulting in economic and environmental damages. In this way, predicting changes in the coastal zone and understanding the beach processes is an essential source of information for the elaboration of coastal management plans. In this context, the present work aims to estimate the alongshore sediment transport (LST) in several sectors of the Brazilian Coast, identifying the annual average and the predominant transport. This study was conducted for the period between the years 1979 and 2015, using computational modeling to investigate the behavior of the waves, and empirical formulas to calculate the LST rates. In addition, the temporal variability was investigated through the wavelet analysis. The results showed a great diversity in the wave climate behavior along the Brazilian Coast, presenting a good correlation in terms of magnitude between the estimation of LST and past studies in the different sectors analyzed. The place where transport has become pronounced understands the sector between Alagoas and Rio Grande do Norte states, while the opposite was observed in the Southern part of Bahia. The wavelet analysis showed that the spectrum of LST time series has a significant amount of energy for processes with a seasonal and annual variability, indicating that the northern regions of Brazil are most affected by the interannual processes. In this sense, informations along the Brazilian coast are presented, that may be considered in future projects, involving the sustainable management of the coastal zones.
IMPLEMENTATION AND TESTING OF A POWER MATRIX-BASED WAVE ENERGY CONVERSION MODEL AND THE EFFECT SIMULATED ON THE WAVE FIELD — CASE STUDY OF LAGUNA, SC, BRAZIL
Authors: Oleinik P. H. , Marques W. C.
Published: June 2019

Electrical energy has become an essential resource for mankind and, as the population and technological dependency grow, also does the electricity demand. This necessity boosted numerous studies which focus on clean and renewable energy sources. Ocean wave energy is one of the most environmentally friendly sources of energy since it does not emit pollutants to the atmosphere and does not produce harmful waste. Another positive point about ocean waves is that they are inexhaustible, therefore a power plant could, potentially, provide energy indefinitely. Hence the object of this study is to estimate the wave energy reduction caused by the presence of wave energy conversion (WEC) devices near the coastline of Laguna, Brazil. In order to study the coastal impact of a WEC farm, the third generation sea state model TOMAWAC was used to simulate the waves on the Southern Brazilian Shelf under two different conditions, with and without the presence of an array of WECs. The results show that the mean significant wave height in the blockaded area undergoes a slight drop, caused by the presence of the WECs, which do not appear in the other scenario. But this reduction of the significant wave height is negligible compared to the order of magnitude of the wave height itself.
NUMERICAL STUDY OF THE GEOMETRIC INFLUENCE OF A FIN IN A CYLINDRICAL HEAT EXCHANGER FOR MELTING OF PCM
Authors: Spengler F. C. , Oliveira B. , Oliveski R. C. , Rocha L. A. O.
Published: June 2019

The thermal heat storage it’s an effective way to suit the energy availability with the demand schedule. It can be stored in the means of sensible or latent heat, the latter applying a material denominated Phase Change Material (PCM), which is provided as organic compounds, hydrated salts, paraffins, among others. The latent heat storage systems offer several advantages, like the practically isothermal process of loading and unloading and the high energy density. However, the low thermal conductivity makes the cycle prolonged on these systems, restricting its applicability. Applying computational fluid dynamics, the behavior of the PCM melting process was studied in cylindrical cavities with horizontal and vertical fins, aiming the optimization of the fin geometry. In this way the fin area was kept constant, varying its aspect ratio. The numerical model was validated with results from the literature and it’s composed of the continuity, momentum and energy equations increased by the phase change model. Qualitative and quantitative results are presented, referring to mesh independence, contours of velocity, net fraction and temperature at different moments of the process. The results of the study indicate that the position of the fin in the heat exchanger influences the melting process, although the vertical fins have a faster total melting process, horizontal fins can reach larger partial liquid fractions in less time in the heat exchanger. Such as the position of the fin, the increase of its length propitiates the reduction of the melting time, evidencing the optimal aspect ratio.
Editorial
Authors: Vargas Jose V. C.
Published: June 2019

O editorial de Engenharia Térmica deste número informa aos leitores que desde 2018 a revista iniciou o registrode DOI para todos os artigos científicos. Inclusive, foram atribuídos DOI a todos os artigos publicados na revista desde o primeiro número.Infelizmente, na primeira implementação dos DOI a todos os artigos anteriormente publicados, houve o erro de todos os artigos serem registrados com o ano de 2018. No entanto, a Universidade Federal do Paraná, UFPR, Brasil, que abriga a produção da revista, corrigiu em maio de 2019 o registro dos anos de todos os artigos anteriormente publicados em seus respectivos DOI, que permanecerão com os mesmos números originalmente atribuídos a eles para evitar dificuldades para os autores em divulgar seus artigos. Apesar dessa correção ter ocorrido, ainda é necessário que o sistema Google faça a reindexação desses artigos com seus dados corretos, o que tipicamente requer em torno de seis meses, momento em que as informações ficarão corretas na internet. Assim, espera-se que até o final de 2019 o problema esteja completamente resolvido. É importante destacar que todos os artigos publicados a partir de 2018 estão com os dados de DOI corretos. Para os artigos publicados antes de 2018, recomenda-se aos autores que registrem os artigos em seus currículos apenas com o ISSN da revista.A missão de Engenharia Térmica é a de documentar o progresso científico em áreas relacionadas à engenharia térmica (e.g., energia, petróleo, combustíveis renováveis). Nós estamos confiantes que continuaremos a receber submissões de artigos que contribuam para o progresso da ciência.
Reviewer Acknowledgements for English Linguistics Research, Vol. 8, No. 2
Authors: Su Camille
Published: June 2019

English Linguistics Research (ELR) would like to acknowledge the following reviewers for their assistance with peer review of manuscripts for this issue. Many authors, regardless of whether ELR publishes their work, appreciate the helpful feedback provided by the reviewers. Their comments and suggestions were of great help to the authors in improving the quality of their papers. Each of the reviewers listed below returned at least one review for this issue.
INVESTIGATION OF LOCAL AND MODAL BASED ACTIVE VIBRATION CONTROL STRATEGIES ON THE EXAMPLE OF AN ELASTIC SYSTEM
Authors: PEUKERT Christoph , PÖHLMANN Patrick , MERX Marcel , IHLENFELDT Steffen , MÜLLER Jens
Published: June 2019

Nowadays, feed axes are often equipped with multiple parallel-acting actuators in order to increase the dynamics of the machine tool. Also, additional actuators for active damping are widely used. Normally, the drives or actuators are controlled independently without consideration for the impact on each other. In contrast, by using the modal space control, the system can be decoupled and the modal control loops can be adjusted independently. This control approach is particularly suitable for motion systems, such as machine tools, which have more drives or actuators than degrees of freedom of movement. This paper deals with the pre-investigation of the modal-based vibration control for machine tools with additional actuators. The object of investigation is an elastic system with a movable saddle. The modal-based control is compared with a local control approach. The results obtained experimentally on the test rig are presented. The modal control is superior since, with the modal approach, each control loop corresponds to a specific vibration mode, and the control law for this loop is designed to provide
the desired performance of the control system at the corresponding resonance frequency. The parameterisation of the control loops is simplified by modal control, since the modes can be controlled independently.
Dopłata jako forma dokapitalizowania spółki osobowej – aspekty prawno-podatkowe
Authors: Sobiech Agnieszka , Sobiech Maciej
Published: June 2019

Funkcjonująca spółka osobowa może wymagać dokapitalizowania. Zasadniczym sposobem dostarczenia kapitału jest wniesienie wkładu pieniężnego bądź niepieniężnego. To rozwiązanie wymaga zmiany umowy spółki i wywołuje takie same skutki podatkowe jak przy zawiązywaniu nowej spółki. Podobnie jak w spółkach kapitałowych zastosować można również metody zwrotne w postaci pożyczek, depozytu nieprawidłowego, zwrotnych dopłat lub bezzwrotne, takie jak np. zawarcie umowy darowizny czy bezzwrotne dopłaty. W praktyce wspólnicy spółek osobowych często zasilają spółki, tworząc kapitał zapasowy czy rezerwowy, i podejmują uchwały o dokonaniu wpłat (czy dopłat) na ten kapitał. Brak szczególnych regulacji powoduje swobodę w ustalaniu sposobu dokapitalizowania spółek osobowych. Ta różnorodność form rodzi problemy w określeniu skutków podatkowych poszczególnych czynności, tym bardziej że ustawy o podatkach dochodowych nie zawierają w tym zakresie szczególnych rozwiązań i konsekwencje podatkowe powstają na zasadach ogólnych.
Regulating bodies: the moral panic of child sexuality in the digital era
Authors: Witting Sabine K.
Published: June 2019

Mit zunehmendem Zugang zum Internet hat sich das explorative Verhalten von Kindern zu Sexualität auch auf den Onlinebereich ausgeweitet. Dies führte zu einer Wiederbelebung der moralischen Panik rund um die kindliche Sexualität, insbesondere in Bezug auf das wachsende Phänomen des einvernehmlichen „Sextings“ zwischen Minderjährigen. Diese moralische Panik wird durch die Sorge um sexuellen Missbrauch und sexuelle Ausbeutung von Kindern im Kontext von „Kinderpornographie“ noch weiter befeuert. In dem Bestreben, Kinder vor solchen Straftaten zu schützen, wird einvernehmliches „Sexting“ zwischen Minderjährigen in manchen Ländern als Produktion und Verbreitung von „Kinderpornographie“ gewertet und führt so zur Strafverfolgung beteiligter Kinder als SexualstraftäterInnen. Das Recht auf Schutz vor sexuellem Missbrauch und Ausbeutung ist hier das dominierende Narrativ. Dieser Artikel argumentiert, dass die Kriminalisierung von Kindern aufgrund einvernehmlicher sexueller Erkundungen im Online-Raum kontraproduktiv für das Ziel des Kinderschutzes ist. Stattdessen sollten Länder in Fällen von einvernehmlichen „Sexting“ zwischen Minderjährigen einen auf Rechten basierenden Ansatz verfolgen und die widerstreitenden Interessen von Autonomie und Kinderschutz dadurch ausgleichen, dass sie das einvernehmliche „Sexting“ zwischen Minderjährigen aus dem Geltungsbereich der „Kinderpornografie“ ausschließen.
Meinungsfreiheit in der digitalen Welt
Authors: Dräger Regina
Published: June 2019

The communication via internet is simple. Thanks to low access barriers and widespread occasions for unimpeded development it is almost an ideal medium for the exchange of ideas and therefore seems particularly suited for the exercise of constitutional freedom. Yet, wherever the freedom of expression is exercised it must also be able to develop its protective functions and it is within this context that the open structure constitutes a challenge to the interpretation of fundamental rights. In order to counteract the premature conclusion that new situations require new solutions, it is advisable to first take a closer look at established structures and ways of interpreting fundamental rights. In particular the approaches and structural concepts inherent in Helmut Ridder’s concept of fundamental rights and its evolution to the transsubjective dimension of fundamental rights could be of use for a concept of fundamental rights that appears to be adequate to these and possibly also future challenges.
The Effect of Leverage on Corporate Cash Holdings: Evidence from Indonesian Manufacturing Firms
Authors: Wijaya Anggita Langgeng , Bandi Name
Published: June 2019

The objective of this research is to test the impact of leverage on corporate cash holdings for sample of manufacturing companies enlisted on the Indonesian Stock Exchange over the period 2006-2007. Population of this research is all of manufacturing companies on the Indonesian Stock Exchange. The sampling method is purposive. The study hypothesis was tested using multiple regressions. The results show that leverage has a negative influence on corporate cash holdings. Indonesian manufacturing firms with high leverage can hold cash in small amounts because debt is a substitute for corporate cash holdings.
Church Father of the Twentieth Century
Authors: Batlogg Andreas R. , O’Meara Thomas F. ,   Philosophy Documentation Center
Published: June 2019

Andreas Battlogg, S.J., one of the supervising editors, discusses the conclusion of the publication of Karl Rahner's Sämtliche Werke in over thirty volumes along with its impact on the study of theology now and in the future.
José Leonilson e a poesia na fissura
Authors:   Universidade Federal do Rio Grande do Sul, Beck Ana Lucia
Published: June 2019

A obra de José Leonilson é uma das produções mais emblemáticas da arte contemporânea brasileira e das mais significativas para a reflexão acerca da relação entre as linguagens verbal e visual. Sua produção é um caso notável de inserção de palavras na produção plástica. Trata-se, porém, de uma inserção na qual além de possuírem estatuto poético as palavras adquirem sentido pela sua apresentação formal e pela característica espacial dos desenhos, pinturas e bordados. Entendemos que tal produção seja significativa para que se reflita sobre as metodologias de análise propostas pela área interartes, uma vez que se apresenta capaz de aferir a eficácia de tais metodologias. Nesse sentido, propomos uma análise da metodologia e nomenclatura de análise propostas inicialmente por Leo Hoeck para os estudos interartes frente à análise de alguns trabalhos de Leonilson. A iniciativa se justifica frente ao desafio de pensarem-se as implicações do uso de tais metodologias para a tradução da obra de Leonilson para o idioma inglês, por exemplo. Basearemos a análise inicialmente em breve reflexão sobre algumas bibliografias relativas à relação entre artes e literatura, bem como procederemos à análise de trabalhos de Leonilson frente também a seu interesse pela poesia.
Alt henger sammen – Hverdagslogistikk og små barns muligheter for tilhørighet i barnehagen
Authors: Eide Brit , Winger Nina , Wolf Kristin Danielsen
Published: June 2019

I det kvalitative forskningsprosjektet «Små barns hverdagsliv i barnehager – deltakelse, tilhørighet og verdighet» har vi, gjennom en mikroetnografisk tilnærming, studert ulike sider av hverdagslivet i et utvalg barnehager med ulike organiseringsmåter. Vi har blant annet satt søkelyset på sammenhenger mellom barnehagens organisering og små barns muligheter for handlingsrom, well-being og livskvalitet. Resultatene fra studien viser at hverdagene, særlig i de store fleksible barnehagene, er preget av til dels utfordrende hverdagslogistikk. Det kreves både tilpassing og evne og vilje til fleksibilitet for at dagene skal gli så «friksjonsfritt» som mulig. I denne artikkelen spør vi i hvilken grad små barn gis muligheter for tilhørighet og deltakelse i barnehagen når hverdagene i stor grad preges av stramme organisatoriske rammer og stadige forflytninger. Materialet fra barnehagene er drøftet i lys av perspektiver på well-being og nyere relevant barnehageforskning.
Nøkkelord: Barnehage, hverdagsliv, logistikk, tilhørighet
Effects of stream grazers with different functional traits on the spatial heterogeneity of periphyton mats
Authors: Katano Izumi , Doi Hideyuki
Published: June 2019

Background

Grazing activity on periphytic mats determines mat structure and spatial heterogeneity. Spatial complexity in stream periphyton is highly divergent and may depend on the functional traits of the different primary consumers species (i.e., grazers) such as mouthpart morphology, feeding behavior, and feeding activity. We evaluated the effect of grazing by three species having different functional traits on periphytic mat structure with a focus on mohthpart morphology.

Methods

An enclosure experiment was conducted in a stream located in the Nara Prefecture of Japan using two caddisflies with scraping mouthparts, Micrasema quadriloba and Glossosoma, and one mayfly, Epeorus, with brushing mouthparts. The spatial heterogeneity of chlorophyll a(Chl a) was evaluated, and the periphytic mat was analyzed using scanning electron microscopy (SEM) after a 12-d feeding experiment.

Results

Our results showed the differences in the spatial heterogeneity of the periphytic mats, such as differences in Chl a levels, grazed by the different grazing species. The strongest effect on the spatial heterogeneity and periphytic abundance was observed for Micrasema quadriloba, a caddisfly species with scraping mouthparts. Epeorus mayfly, with brushing mouthparts and high-mobility behavior, produced the weakest effect on spatial heterogeneity. Glossosoma caddisflies had moderate effects on periphytic spatial heterogeneity and abundance. Our results suggest that differences in grazing effects are largely dependent on grazer mouthparts and behavior.
Analytical Study of a System of Dierence Equation
Authors: Sanbo Abdualrazaq , Elsayed Elsayed M.
Published: June 2019

We study the qualitative behavior of a predator-prey model, where the carrying capacity of the predators environment is proportional to the number of prey. The considered system is given by the following rational difference equations:

where the initial conditions x-2; x-1; x0; y-2; y-1; y0 are arbitrary positive real numbers. Also, we give specic form of the solutions of some special cases of this equation. Some numerical examples are given to verify our theoretical results.
A Microfluidic System for One‐Chip Harvesting of Single‐Cell‐Laden Hydrogels in Culture Medium
Authors: Nan Lang , Yang Zhenyu , Lyu Hao , Lau Kitty Yu Yeung , Shum Ho Cheung
Published: June 2019

Single‐cell analysis has shown great potential to fully quantify the distribution of cellular behaviors among a population of individuals. Through isolation and preservation of single cells in the aqueous phase, droplet encapsulation followed by gelation enables high‐throughput analysis in biocompatible microgels. However, the lack of control over the number of cells encapsulated and complicated gelation processes significantly limit its efficiency. Here, a microfluidic system for one‐chip harvesting of single‐cell‐laden microgels is presented. Through ultraviolet irradiation, an on‐chip gelation technique is seamlessly combined with droplet generation to realize high‐throughput fabrication of microscale hydrogels in microfluidic channel. Moreover, a sorting module is introduced to simultaneously complete cell‐laden microgel selection and transfer into culture medium. To demonstrate the efficiency of this method, two types of single cells are respectively encapsulated and collected, showing desirable single‐cell encapsulation and cell viability. This technique realizes integrated droplet gelation, microgel sorting, and transfer into culture medium, allowing high‐throughput analysis of single cells and comprehensive understanding of the cellular specificity.
AFM Study of pH‐Dependent Adhesion of Single Protein to TiO2 Surface
Authors: Dong Yihui , Laaksonen Aatto , Cao Wei , Ji Xiaoyan , Lu Xiaohua
Published: June 2019

The effect of pH‐induced electrostatic conditions on the molecular interaction force of a single lysozyme molecule with TiO2 is investigated using atomic force microscopy (AFM). The force between the charged or neutral lysozyme molecule and the TiO2 surface is measured at different pH from 3.6 to 10.8. It is found to be directly proportional to the contact area, given by an effective diameter of the lysozyme molecule, and is further qualitatively verified by the AFM‐measured friction coefficients. The results of the Derjaguin–Landau–Verwey–Overbeek theory show that the pH can change the surface charge densities of both lysozyme and TiO2, but the molecular interaction force at different pH is only dependent on the pH‐induced effective diameter of lysozyme. The molecular interaction forces, quantified at the nanoscale, can be directly used to design high‐performance liquid chromatography measurements at macroscale by tuning the retention time of a protein under varied pH conditions. They can also be applied to develop a model for predicting and controlling the chromatographic separations of proteins.
Tailoring Spectral and Temporal Properties of Semiconductor Nanowire Lasers
Authors: Zapf Maximilian , Sidiropoulos Themistoklis , Röder Robert
Published: June 2019

Semiconductor optoelectronics have contributed tremendously to various aspects of the technological progress in the past. Recently, they also stimulate research in nanophotonics seeking to overcome the inherent limitations of electronic integrated circuits and satisfy the growing demand for faster on‐chip communications. In particular, nanowire (NW) lasers generate coherent light at the nanoscale and meanwhile work consistently at room temperature covering a huge spectral range from the ultraviolet down to the mid‐infrared depending on the NW material. The underlying physics of their electronic and photonic systems are also studied very recently, thus NW lasers become relevant as an emergent tool for a variety of practical applications. In this review, the origins determining the emission wavelength of the device are explained, and approaches toward efficient improvement of the NW laser devices in terms of emission energy tunability are summarized. The optical mode field distribution strongly influences the emission dynamics of the nanolaser device; it will be highlighted how increasing the light–matter interaction in plasmonic type nanolasers causes a significant acceleration of their temporal emission dynamics. Both spectral and temporal tuning will help to solve scientific and engineering challenges forging semiconductor nanowire lasers into powerful tools for nanosensing, nanospectroscopy, and nanotechnology.
Cascade‐Type Prelithiation Approach for Li‐Ion Capacitors
Authors: Anothumakkool Bihag , Wiemers‐Meyer Simon , Guyomard Dominique , Winter Martin , Brousse Thierry , Gaubicher Joel
Published: June 2019

An industry‐relevant method for pre‐lithiation of lithium‐ion capacitors to balance the first charge irreversibility is demonstrated, which addresses the prime bottleneck for their market integration. Based on a composite positive electrode that integrates pyrene monomers and an insoluble lithiated base, Li3PO4, a “cascade‐type” process involving two consecutive irreversible reactions is proposed: i) oxidative electropolymerization of the pyrene moieties releases electrons and protons; ii) protons are captured by Li3PO4 and exchanged for a stoichiometric amount of Li+ into the electrolyte. (1H, 19F, and 31P) NMR spectroscopy, operando X‐ray diffraction, and Raman spectroscopy support this mechanism. By decoupling the irreversible source of lithium ions from electrons, the cascade‐type pre‐lithiation allows the simultaneous enhancement of the capacity of the positive electrode, thanks to p‐doping of the resulting polymer. Remarkably, the proton scavenging properties of Li3PO4 also boost the polymerization process, which enables a 16% increase in capacity without detrimental effect on power properties and cyclability. Full cells integrating a cheap carbon black based negative electrode, show much‐improved capacity of 17 mAh g‐1electrodes (44 F g‐1electrodes, 3–4.4 V) and excellent stability over 2200 cycles at 1 A g‐1. Thanks to its versatile chemistry and flexibility this approach in principle can be applied to any kind of ion‐battery.
Quantifying and Understanding Voltage Losses Due to Nonradiative Recombination in Bulk Heterojunction Organic Solar Cells with Low Energetic Offsets
Authors: Rosenthal Katie D. , Hughes Michael P. , Luginbuhl Benjamin R. , Ran Niva A. , Karki Akchheta , Ko Seo‐Jin , Hu Huawei , Wang Ming , Ade Harald , Nguyen Thuc‐Quyen
Published: June 2019

Open‐circuit voltage (VOC) losses in organic photovoltaics (OPVs) inhibit devices from reaching VOC values comparable to the bandgap of the donor–acceptor blend. Specifically, nonradiative recombination losses (∆Vnr) are much greater in OPVs than in silicon or perovskite solar cells, yet the origins of this are not fully understood. To understand what makes a system have high or low loss, an investigation of the nonradiative recombination losses in a total of nine blend systems is carried out. An apparent relationship is observed between the relative domain purity of six blends and the degree of nonradiative recombination loss, where films exhibiting relatively less pure domains show lower ∆Vnr than films with higher domain purity. Additionally, it is shown that when paired with a fullerene acceptor, polymer donors which have bulky backbone units to inhibit close π–π stacking exhibit lower nonradiative recombination losses than in blends where the polymer can pack more closely. This work reports a strategy that ensures ∆Vnr can be measured accurately and reports key observations on the relationship between ∆Vnr and properties of the donor/acceptor interface.
Chiral phosphoric triamide‐based polymers for enantioseparation
Authors: Ahmadabad Fatemeh Karimi , Pourayoubi Mehrdad , Bakhshi Hadi
Published: June 2019

Novel optical isomers of phosphoramide‐methacrylate monomers were synthesized and used for the preparation of corresponding polymers and hydrogels as chiral absorbents. In order to direct enantioseparation, two simple and inexpensive methods were designed: (a) immobilization of the chiral polymers on glass beads as packing material for the separation columns and (b) filling of chiral hydrogels in tea bags to fabricate separation bags. The specific rotations for R‐ and S‐monomers were + 22.0° and − 21.8°, while those for R‐ and S‐polymers were + 20.8° and − 22.1°, respectively. The enantioseparation of (±)‐α‐methylbenzylamine, DL‐alanine, DL‐valine, DL‐tartaric acid, DL‐phenylalanine, and omeprazole was evaluated. The maximum enantioseparation (optical purity) of 97% was observed for (±)‐α‐methylbenzylamine by S‐hydrogel. Chiral hydrogels resulted in enantioseparations with higher purities (up to 97%) comparing to the chiral polymers, but in longer times (2–3 days). The desorption process easily occurred from the absorbed columns or bags. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48034.
On construction of single‐arm two‐stage designs with consideration of both response and toxicity
Authors: Yin Huan , Wang Weizhen , Zhang Zhongzhan
Published: June 2019

When establishing a treatment in clinical trials, it is important to evaluate both effectiveness and toxicity. In phase II clinical trials, multinomial data are collected in m‐stage designs, especially in two‐stage () design. Exact tests on two proportions, for the response rate and for the nontoxicity rate, should be employed due to limited sample sizes. However, existing tests use certain parameter configurations at the boundary of null hypothesis space to determine rejection regions without showing that the maximum Type I error rate is achieved at the boundary of null hypothesis. In this paper, we show that the power function for each test in a large family of tests is nondecreasing in both and ; identify the parameter configurations at which the maximum Type I error rate and the minimum power are achieved and derive level‐α tests; provide optimal two‐stage designs with the least expected total sample size and the optimization algorithm; and extend the results to the case of . Some R‐codes are given in the Supporting Information.
The Application of microRNAs in Biomaterial Scaffold‐Based Therapies for Bone Tissue Engineering
Authors: Arriaga Marco A. , Ding May‐Hui , Gutierrez Astrid S. , Chew Sue Anne
Published: June 2019

In recent years, the application of microRNAs (miRNAs) or anti‐microRNAs (anti‐miRNAs) that can induce expression of the runt‐related transcription factor 2 (RUNX2), a master regulator of osteogenesis, has been investigated as a promising alternative bone tissue engineering strategy. In this review, biomaterial scaffold‐based applications that have been used to deliver cells expressing miRNAs or anti‐miRNAs that induce expression of RUNX2 for bone tissue engineering are discussed. An overview of the components of the scaffold‐based therapies including the miRNAs/anti‐miRNAs, cell types, gene delivery vectors, and scaffolds that have been applied are provided. To date, there have been nine miRNAs/anti‐miRNAs (i.e., miRNA‐26a, anti‐miRNA‐31, anti‐miRNA‐34a, miRNA‐135, anti‐miRNA‐138, anti‐miRNA‐146a, miRNA‐148b, anti‐miRNA‐221, and anti‐miRNA‐335) that have been incorporated into scaffold‐based bone tissue engineering applications and investigated in an in vivo bone critical‐sized defect model. For all of the biomaterial scaffold‐based miRNA therapies that have been developed thus far, cells that are transfected or transduced with the miRNA/anti‐miRNA are loaded into the scaffolds and implanted at the site of interest instead of locally delivering the miRNA/anti‐miRNAs directly from the scaffolds. Thus, future work may focus on developing biomaterial scaffolds to deliver miRNAs or anti‐miRNAs into cells in vivo.
HPLC–UV method for temozolomide determination in complex biological matrices: Application for in vitro, ex vivo and in vivo studies
Authors: Michels Luana R. , Fachel Flávia N.S. , Azambuja Juliana H. , Gelsleichter Nicolly E. , Braganhol Elizandra , Teixeira Helder F.
Published: June 2019

A high‐performance liquid chromatography method for temozolomide (TMZ) determination in complex biological matrices was developed and validated for application in in vitro, ex vivo and in vivo studies of new nanotechnology‐based systems for TMZ nasal delivery. The method was able to quantify TMZ in nanoemulsions, following cellular uptake, in the porcine nasal mucosa and in mouse plasma and brain. Analyses were performed on a C18 column at 35°C, under UV detection at 330 nm. The mobile phase was methanol–acetic acid 0.5% (30:70, v/v), eluted at an isocratic flow rate of 1.1 mL/min. The method was found to be specific, precise, accurate, robust and linear (0.05 to 5 μg/mL) for TMZ determination in all matrices. No interference of TMZ degradation products was found under various stress conditions such as acidic, alkaline, oxidative, light and thermal exposure, demonstrating stability. The method was applied for the quantification of TMZ in different matrices, i.e. the efficiency of nanoemulsions in vitro in increasing TMZ cellular uptake, ex vivo TMZ permeation and retention in the porcine nasal mucosa tissue, and for in vivo TMZ quantification in mouse brain following intranasal nanoemulsion administration compared with free TMZ.
Apelin and stem cells: the role played in the cardiovascular system and energy metabolism
Authors: Esmaeili Shahnaz , Bandarian Fatemeh , Esmaeili Behnaz , Nasli‐Esfahani Ensieh
Published: June 2019

Apelin, a member of the adipokine family, is widely distributed in the body and exerts cytoprotective effects on many organs. Apelin isoforms are involved in different physiological processes, including regulation of the cardiovascular system, cardiac contractility, angiogenesis, and energy metabolism. Several investigations have been performed to study the effect of apelin on stem cell therapy. This review aims to summarize the literature representing the effects of apelin on stem cell properties. Furthermore, this review discusses the therapeutic potential of apelin‐treated stem cells for cardiovascular diseases and demonstrates the effect of stem cells overexpressing apelin on energy metabolism. Stem cells with their unique characteristics play a crucial role in the maintenance of tissue integrity. These cells participate in tissue regeneration via multiple mechanisms. Although preclinical and clinical studies have demonstrated the therapeutic potential of stem cells in various diseases, their application in regenerative medicine has not been efficient. A number of strategies such as genetic modification or treatment of stem cells with different factors have been used to improve the efficacy of cell therapy and to increase their survival after transplantation. This article reviews the effect of apelin treatment on the efficacy of cell therapy.
Nationwide outcomes of aortic valve replacement for pure aortic regurgitation in Germany 2008–2015
Authors: Stachon Peter , Kaier Klaus , Heidt Timo , Bothe Wolfgang , Zirlik Andreas , Zehender Manfred , Bode Christoph , von zur Mühlen Constantin
Published: June 2019

Background

Transcatheter aortic valve replacement (TAVR) is routinely used in patients with severe aortic stenosis at increased operative risk. Due to potential technical difficulties, TAVR is not recommended for pure aortic regurgitation (AR). Smaller studies reported its use in AR, but data from big registries are lacking. The present study analyzes the nationwide use of surgical aortic valve replacement (SAVR) and TAVR in patients with AR from 2008 until 2015.

Methods

We identified 138,237 cases of aortic valve replacement in Germany based on ICD and OPS codes.

Results

Of 13.2% SAVR‐cases and 1.3% of TAVR cases were performed in AR. AR patients undergoing SAVR were younger with lower logistic EuroSCORE (stenosis: 6.1 ± 5.6; AR: 4.5 ± 4.9). Nevertheless, stroke rates, bleedings, prolonged mechanical ventilation, and in‐hospital mortality were higher (mortality: stenosis 2.6%, AR: 4.7%). In the TAVR group, patients with AR were at higher operative risk (logistic EuroSCORE: transfemoral (TF)‐TAVR: stenosis: 14.3 ± 10.4; AR: 17.3 ± 13.3. Transapical (TA)‐TAVR: stenosis: 16.1 ± 11.4; AR: 15.7 ± 12.2). Stroke rates were lower, but bleedings and prolonged ventilation occurred more frequently after TF‐TAVR in AR compared to stenosis. The mortality varied markedly (TF‐TAVR: 15.2% in 2011; 2.8% in 2015; TA‐TAVR: 17.7% in 2012 and 0% in 2014).

Conclusion

TAVR is off‐label used in AR in clinical practice. TAVR seems to be a safe option for AR with regard to in‐hospital outcomes. However, further research evaluating long‐term outcomes is required to establish the feasibility of TAVR in pure AR.
Keramische Membranen in der Membrandestillation
Authors: Schnittger Johann , Weyd Marcus , Voigt Ingolf , Lerch André
Published: June 2019

Makroporöse TiO2‐Membranen konnten erfolgreich mit Perfluoroalkylsilanen hydrophobiert werden und anschließend mittels liquid entry pressure (LEP)‐Tests charakterisiert und in der Membrandestillation (MD) getestet werden. Es konnte gezeigt werden, dass der LEP stark von der Porengröße und Feedbeschaffenheit beeinflusst wird. In der Vakuum‐MD konnten die höchsten Permeatflüsse erreicht werden. In der Air‐gap‐MD und der Vakuum‐MD konnten Rückhalte von über 99,9 % und hervorragende Produktwasserqualitäten erzielt werden.
Experimental methods in chemical engineering: Artificial neural networks–ANNs
Authors: Panerati Jacopo , Schnellmann Matthias A. , Patience Christian , Beltrame Giovanni , Patience Gregory S.
Published: June 2019

Artificial neural networks (ANNs) are one of the most powerful and versatile tools provided by artificial intelligence and they have now been exploited by chemical engineers for several decades in countless applications. ANNs are computational tools providing a minimalistic mathematical model of neural functions. Coupled with raw data and a learning algorithm, they can be applied to tasks such as modelling, classification, and prediction. Recently, their popularity has grown remarkably and they now constitute one of the most relevant research areas within the fields of artificial intelligence and machine learning. ANNs are large collections of simple classifiers called neurons. Chemical engineers apply them to model complex relationships, predict reactor performance, and to automate process controllers. ANNs can leverage their ability to learn and exploit large data sets, but they can also get stuck in local minima or overfit and are difficult to reverse engineer. In 2016 and 2017, ANNs were cited in 13 245 Web of Science (WoS) articles, 538 of which were in chemical engineering; the top WoS categories were electrical & electronic engineering (1615 occurrences) artificial intelligence (1253), and energy & fuels (980). The top 4 journals mentioning ANNs were Neural Computing & Applications (117), Neurocomputing (84), Energies (76), and Renewable & Sustainable Energy Reviews (76). In the near future, as larger data sets become available (and arduous to analyze), chemical engineers will be able to apply and leverage more sophisticated ANN architectures.
Comparison of environmental flows from a habitat suitability perspective: A case study in the Naeseong‐cheon Stream in Korea
Authors: Kim Seung Ki , Choi Sung‐Uk
Published: June 2019

Environmental flow is the amount of water flow required to maintain the health of a river ecosystem. Environmental flow includes both optimal flow and minimum flow. The former is the amount of flow that guarantees the complete function of a stream ecosystem, whereas the latter is the amount of flow below which the stability and health of a stream ecosystem cannot be maintained. This study attempts to compare environmental flows computed by various environmental flow methodologies, including hydrological methods, hydraulic rating methods, and habitat simulation methods. For the habitat simulation method, physical habitat simulations were carried out using habitat suitability curves for Zacco platypus. The study site is a 20‐km‐long reach of the Naeseong‐cheon Stream downstream from the Youngju Dam in Korea. The Naeseong‐cheon Stream is a moderately sized stream (order 8) with a normal flow of 4.1 m3/s. It was found that environmental flows vary greatly depending on the selection of methodologies. Specifically, the minimum flows by the hydrological methods were significantly smaller than those by the hydraulic rating methods or the habitat simulation methods, and the optimal flow by the hydraulic rating method is much larger than those by the other two methods. Physical habitat simulations for various minimum flows revealed that the minimum flow by the hydrological methods might fail to provide the minimum requirement for an aquatic habitat.
Is yield curve predicting a US recession in 2020?
Authors: Tokic Damir
Published: June 2019

The yield curve spread has predicted every US recession. As of mid‐2019, the inverted yield curve spread is flashing a warning sign about a possible US recession in 2020. This article explains the yield curve spread, and discusses the possible 2020 recession triggers.
Prevalence and characteristics of methicillin‐resistant Staphylococcus aureus colonization among healthcare professionals in a university hospital in Japan
Authors: Yamasaki Fumi , Takeuchi Seisho , Uehara Yoshio , Matsushita Masahide , Arise Kazumi , Morimoto Norihito , Seo Hiromi
Published: June 2019

Background

Asymptomatic carriers of methicillin‐resistant Staphylococcus aureus (MRSA) are important sources of nosocomial transmission. MRSA may be transmitted from hospitalized patients to healthcare professionals and vice versa.

Methods

The prevalence of MRSA colonization among forty‐five healthcare professionals in a Japanese hospital was determined by performing surveillance cultures to identify unrecognized carriers of MRSA. All MRSA isolates were evaluated using multilocus sequence typing (MLST) to identify the transmission routes.

Results

The proportion of MRSA colonization was significantly higher in healthcare professionals (11.1%) than in community residents (0.72%; P < 0.0001) or admission case (2.5%; P = 0.018). MLST analysis revealed that both the ST8 and ST764 strains were identified in residents, patients, and healthcare professionals. MRSA colonization was more frequently observed among physicians (4/13; 31%) than nurses (1/32; 3%) (P = 0.020).

Conclusion

Multilocus sequence typing results suggest that ST8 and ST764 are involved in the occurrence of nosocomial MRSA infections. These findings emphasize the necessity for the effective education of physicians to prevent MRSA transmissions.
A single miRNA and miRNA sponge expression system for efficient modulation of miR‐223 availability in mammalian cells
Authors: Huerta‐Zavala Mariel Lizbeth , Lopez‐Castillejos Erika Sicahui , Requenez‐Contreras José Luis , Granados‐Riveron Javier Tadeo , Aquino‐Jarquin Guillermo
Published: June 2019

Background

Hundreds of microRNAs (miRNAs), comprising small non‐coding RNAs of 20–24 nucleotides, have been discovered, although the entirety of their biological functions is poorly understood. Overexpression or suppression approaches are commonly performed to investigate the function of specific miRNAs. In the present study, we focused on generating a lentiviral vector‐based strategy that enables hsa‐miR‐223‐3p (miR‐223) overexpression and suppression in the target cells for functional analysis of this miRNA easily and rapidly.

Methods

The sequence that gives rise to miR‐223 and the sequence generating the sponge RNA with four binding sites for miR‐223 were cloned in pLVX‐shRNA2 vector. The functionality of the vector to overexpress miR‐223 was evaluated by quantitative reverse transcriptase‐polymerase chain reaction (qRT‐PCR) assays, whereas the post‐transcriptional regulation exerted by miR‐223 was evaluated by luciferase reporter assays in AD‐293 cells. The anti‐miR‐223 sponge activity with one binding site for miR‐223 (pmCherry‐anti‐miR‐223) was confirmed by qRT‐PCR and the restoration of its target (IKKα) was evaluated by western blot assays in Jurkat cells.

Results

The pLVX‐miR‐223 vector is functional for over‐expressing miR‐223 and regulates the mRNA of MDR1/ABCB1 at the post‐transcriptional level in AD‐293 cells. The anti‐miR‐223 sponge with one miR‐223 binding site efficiently modulates the miR‐223 availability and not the one with four sites. The over‐expression of anti‐miR‐223 correlated with a decrease in the levels of miR‐223 and, consequently, with an increase in the expression level of the IKKα protein in Jurkat cells.

Conclusions

This single miRNA and miRNA sponge expression system specifically alters the availability of miR‐223 in mammalian cells.
Suppression of Notch Signaling in Osteoclasts Improves Bone Regeneration and Healing
Authors: Goel Peeyush N. , Moharrer Yasaman , Hebb John H. , Egol Alexander J. , Kaur Gurpreet , Hankenson Kurt D. , Ahn Jaimo , Ashley Jason W.
Published: June 2019

Owing to the central role of osteoclasts in bone physiology and remodeling, manipulation of their maturation process provides a potential therapeutic strategy for treating bone diseases. To investigate this, we genetically inhibited the Notch signaling pathway in the myeloid lineage, which includes osteoclast precursors, using a dominant negative form of MAML (dnMAML) that inhibits the transcriptional complex required for downstream Notch signaling. Osteoclasts derived from dnMAML mice showed no significant differences in early osteoclastic gene expression compared to the wild type. Further, these demonstrated significantly lowered resorption activity using bone surfaces while retaining their osteoblast stimulating ability using ex vivo techniques. Using in vivo approaches, we detected significantly higher bone formation rates and osteoblast gene expression in dnMAML cohorts. Further, these mice exhibited increased bone/tissue mineral density compared to wild type and larger bony calluses in later stages of fracture healing. These observations suggest that therapeutic suppression of osteoclast Notch signaling could reduce, but not eliminate, osteoclastic resorption without suppression of restorative bone remodeling and, therefore, presents a balanced paradigm for increasing bone formation, regeneration, and healing. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2089–2103, 2019