bluuebunny/crossref_metadata_2025 huggingface dataset:
Reaprendizagem de conceitos com o auxílio de recursos didáticos: experiências de formação no programa pró-letramento
Authors: Nascimento Ana Maria Porto do , Silva Américo Junior Nunes da , Oliveira Marcos Andre Teles Luna , Santos Adelaide Batista Corado , Silva Lidiane Carla Oliveira Franco
Published: January 2018

Este relato versa sobre a experiência vivenciada durante a formação de professores dos Anos Iniciais do Ensino Fundamental, na área de Matemática do Programa Pró-Letramento, realizado no Estado da Bahia. Os formadores articularam os saberes disciplinares e pedagógicos na busca de promover aos professores cursistas um processo de reaprendizagem significativa e o (re)pensar da prática pedagógica respeitando-se as especificidades dos educandos. A interação entre formador, orientador de estudo e professor cursista diferenciou o trabalho realizado e contribuiu na proposição de atividades de ensino que se aproximaram do trabalho em sala de aula, promovendo a (re)significação de tais atividades pelos professores para posterior utilização com os alunos. Será objeto de análise o trabalho realizado com os conteúdos de Números e Operações explorados nos fascículos 1 e 2 do Programa Pró-Letramento. Os recursos didáticos colocaram-se como instrumentos mediadores na reaprendizagem de conceitos pelos professores em formação.
Research Commentary: When and Why Replication Studies Should be Published: Guidelines for Mathematics Education Journals
Authors: Star Jon R.
Published: January 2018

The present issue of JRME features three articles—Melhuish (2018); Jamil, Larsen, and Hamre (2018); and Thanheiser (2018)—that involve, at least to some degree, replication of prior published studies. In each of these articles, the authors provide a clear rationale for the importance of the work, and in all three cases, the importance of replication of prior work is discussed. The authors of these three articles point out that the scientific community writ large values replication, and they also note that replication is quite rare in educational research generally and in mathematics education research more specifically.
Research Commentary: A Rejoinder: A Reflection on the Evolution of a Replication Study
Authors: Jamil Faiza M.
Published: January 2018

I appreciate the opportunity to respond to the thoughtful comments made by Alan Schoenfeld (2018) and Jon Star (2018) in their commentaries on replication studies in this issue of JRME, including their comments on our study of teacher expectancy effects (Jamil, Larsen, & Hamre, 2018). I have decided to write this rejoinder in the form of a personal reflection. As academics, we carry the tremendous burden of expertise, and perhaps that is partly why, as pointed out by Schoenfeld (2018), the academic reward system focuses so heavily on novelty and innovation. With our expertise, we are supposed to have all the answers, solve all the problems, and do so in brilliant, new ways. Replication studies are undervalued because they not only, by definition, recreate past research but, perhaps, also bring into question another scholar‧s expertise. Star (2018) even states that one of the three criteria of an outstanding replication study is that it “convincingly shows that there is reason to believe that the results of the original study may be flawed” (p. 99). Although this rigorous examination is precisely the way to build trust in the quality of our findings and move the field forward, it is also what makes it challenging to have candid conversations about what we do not know.
Tilblivelse
Authors: Knabe Martin
Published: January 2018

Digt af Martin Knabe.
Historien, tiden og fortiden. Om billedet af historieskrivningen i Oplysningstiden
Authors: Eskildsen Kasper Risbjerg
Published: January 2018

Kasper Risbjerg Eskildsen: “History, Time, and the Past. On the Image of History Writing in the Enlightenment”During the 18th century, the image of the historian changed dramatically. The proper historian was no longer a man of the world, who wrote from personal experience, but a professional, who gained his authority from his training and academic background. The essay investigates this transformation through images of history writing and argues that the shift in the image of the historian was connected to a new sense of the precarity of the past and to a new divide between history and the past. *Online-version adskiller sig fra den trykte version.
A MOBILIDADE REVISITADA: CAPITAL, TRABALHO E SUBJETIVAÇÃO/Revisiting mobility: capital, labor and subjectivation
Authors: Leite Ana Carolina Gonçalves , Giavarotti Daniel Manzione , Kluck Erick Gabriel , Boechat Cássio Arruda , Toledo Carlos de Almeida
Published: January 2018

Apresentamos um panorama de debates sobre a questão migratória brasileira, focando mobilidade espacial ou territorial da população. Discutimos contribuições teóricas e tipologias daquele campo, além do papel do planejamento na reprodução do mesmo. Explicitamos os limites dos troncos neoclássico e histórico-estrutural a partir da abordagem da mobilidade do trabalho e problematizamos a última por sua perspectiva ontológica do trabalho. Apontamos, por fim, o caráter fetichista de uma sociabilidade assentada no trabalho e no tautológico processo de valorização do valor, na qual pesquisador e produção de conhecimento se reproduzem como partes constitutivas da relação. ABSTRACTFrom 1990s reviews of theoretical perspectives on migratory studies we here propose an analysis and a critique of one of them. With this paper, we highlight the decisive contributions of the theory of the labor mobility enabling to question the separation between the structural determinations claimed by the so-called historical-structural approach and the subjective will claimed by the neoclassic approach, besides the role performed by the discourses over migration and the mechanisms played by them as forms of controlling the space, the labor and the worker. However, we aim at moving the controversy further by proposing a critical reading of this very perspective in order to reveal its limits concerning the ontological conceptualization of labor in which its stands. Finally, we reflect upon the contemporary critical conditions of labor mobility and upon the position of crisis administration undertaken by the State planning together with the scientific production that supports it, what makes essential the critique even of those subjects who produce migratory studies. Keywords: Mobility of Labor; Critique of Labor; Fetishism.
Biotea: semantics for Pubmed Central
Authors: Garcia Alexander , Lopez Federico , Garcia Leyla , Giraldo Olga , Bucheli Victor , Dumontier Michel
Published: January 2018

A significant portion of biomedical literature is represented in a manner that makes it difficult for consumers to find or aggregate content through a computational query. One approach to facilitate reuse of the scientific literature is to structure this information as linked data using standardized web technologies. In this paper we present the second version of Biotea, a semantic, linked data version of the open-access subset of PubMed Central that has been enhanced with specialized annotation pipelines that uses existing infrastructure from the National Center for Biomedical Ontology. We expose our models, services, software and datasets. Our infrastructure enables manual and semi-automatic annotation, resulting data are represented as RDF-based linked data and can be readily queried using the SPARQL query language. We illustrate the utility of our system with several use cases. Our datasets, methods and techniques are available at http://biotea.github.io.
Heteroassociative storage of hippocampal pattern sequences in the CA3 subregion
Authors: de Camargo Raphael Y. , Recio Renan S. , Reyes Marcelo B.
Published: January 2018

Background

Recent research suggests that the CA3 subregion of the hippocampus has properties of both autoassociative network, due to its ability to complete partial cues, tolerate noise, and store associations between memories, and heteroassociative one, due to its ability to store and retrieve sequences of patterns. Although there are several computational models of the CA3 as an autoassociative network, more detailed evaluations of its heteroassociative properties are missing.

Methods

We developed a model of the CA3 subregion containing 10,000 integrate-and-fire neurons with both recurrent excitatory and inhibitory connections, and which exhibits coupled oscillations in the gamma and theta ranges. We stored thousands of pattern sequences using a heteroassociative learning rule with competitive synaptic scaling.

Results

We showed that a purely heteroassociative network model can (i) retrieve pattern sequences from partial cues with external noise and incomplete connectivity, (ii) achieve homeostasis regarding the number of connections per neuron when many patterns are stored when using synaptic scaling, (iii) continuously update the set of retrievable patterns, guaranteeing that the last stored patterns can be retrieved and older ones can be forgotten.

Discussion

Heteroassociative networks with synaptic scaling rules seem sufficient to achieve many desirable features regarding connectivity homeostasis, pattern sequence retrieval, noise tolerance and updating of the set of retrievable patterns.
A gene expression-based risk model reveals prognosis of gastric cancer
Authors: Deng Xiaorong , Xiao Qun , Liu Feng , Zheng Cihua
Published: January 2018

Background

The prognosis of gastric cancer is difficult to determine, although clinical indicators provide valuable evidence.

Methods

In this study, using screened biomarkers of gastric cancer in combination with random forest variable hunting and multivariable Cox regression, a risk score model was developed to predict the survival of gastric cancer. Survival difference between high/low-risk groups were compared. The relationship between risk score and other clinicopathological indicators was evaluated. Gene set enrichment analysis (GSEA) was used to identify pathways associated with risk scores.

Results

The patients with high risk scores (median overall survival: 20.2 months, 95% CI [16.9–26.0] months) tend to exhibit early events compared with those with low risk scores (median survival: 70.0 months, 95% CI [46.9–101] months, p = 1.80e–5). Further validation was implemented in another three independent datasets (GSE15459, GSE26253, GSE62254). Correlation analyses between clinical observations and risk scores were performed, and the results indicated that the risk score was not significantly associated with gender, age and primary tumor size but was significantly associated with grade and tumor stage. In addition, the risk score was also not influenced by radiation therapy. Cox multivariate regression and three-year survival nomogram suggest that the risk score is an important indicator of gastric cancer prognosis. GSEA was used to identified KEGG pathways significantly associated with risk score, and signaling pathways involved in focal adhesion and the TGF-beta signaling pathway were identified.

Conclusion

The risk score model successfully predicted the survival of 1,294 gastric cancer samples from four independent datasets and is among the most important indicators in clinical clinicopathological information for the prognosis of gastric cancer. To our knowledge, it is the first report to predict the survival of gastric cancer using optimized expression panel.
Role of mitochondrial ROS in the brain: from physiology to neurodegeneration
Authors: Angelova Plamena R. , Abramov Andrey Y.
Published: January 2018

Mitochondria are key cell organelles in that they are responsible for energy production and control many processes from signalling to cell death. The function of the mitochondrial electron transport chain is coupled with the production of reactive oxygen species (ROS) in the form of superoxide anion or hydrogen peroxide. As a result of the constant production of ROS, mitochondria are protected by highly efficient antioxidant systems. The rapidly changing levels of ROS in mitochondria, coupled with multiple essential cellular functions, make ROS apt for physiological signalling. Thus, mutations, environmental toxins and chronic ischaemic conditions could affect the mitochondrial redox balance and lead to the development of pathology. In long‐living and non‐mitotic cells such as neurons, oxidative stress induced by overproduction of mitochondrial ROS or impairment of the antioxidant defence results in a dysfunction of mitochondria and initiation of the cell death cascade. Mitochondrial ROS overproduction and changes in mitochondrial redox homeostasis have been shown to be involved in both a number of neurological conditions and a majority of neurodegenerative diseases. Here, we summarise the involvement of mitochondrial ROS in the mechanism of neuronal loss of major neurodegenerative disorders.
Substitution of one calcium‐binding amino acid strengthens substrate binding in a thermophilic alginate lyase
Authors: Wang Bing , Ji Shi‐Qi , Ma Xiao‐Qing , Lu Ming , Wang Lu‐Shan , Li Fu‐Li
Published: January 2018

Ligand binding is sensitive to temperatures since noncovalent bonds between the binding site and ligand could be broken by heat. How metal ion‐binding amino acids in alginate lyase evolve to achieve tight substrate binding in a hostile environment remains unknown. An endolytic alginate lyase AlgAT0 specifically cleaved the M–G glycosidic bond and released disaccharides as the main end product. Four conserved calcium‐binding sites were predicted and the supplement of Ca2+ led to enhanced substrate binding and protein stability. Among the four conserved calcium‐binding sites, one substitution of aspartate for glutamate in AlgAT0 was proved to stimulate Ca2+ affinity. This study suggested that substrate affinity of polysaccharide lyases could be improved by tight binding to Ca2+ via one amino acid substitution.
The Effective Transmissivity of a Plane‐Walled Fracture With Circular Cylindrical Obstacles
Authors: Jasinski Lukasz , Dabrowski Marcin
Published: January 2018

Stimulated and propped fractures provide the conductive pathways in low matrix permeability rocks. We study the impact of fracture aperture and proppant size and fraction on the effective transmissivity of a stimulated fracture filled with a partial monolayer of proppant grains. The proppant grains are treated as circular cylindrical obstacles, and the fracture walls are planar. The key geometric parameters are the obstacle fraction f and the ratio between the fracture aperture and the obstacle diameter α. We use three‐dimensional Stokes flow numerical simulations to demonstrate that the fracture flow model given by the Reynolds equations may largely overestimate the flow rate. To circumvent the inability of the Reynolds model to fulfill the no‐slip boundary condition at the rims of the obstacles, we use the Brinkman flow model adapted to the case of fracture flow. The relative difference between the effective transmissivities computed with the Stokes and Brinkman models for systems with multiple obstacles is below 10% for fractions up to 0.5. We use the Brinkman model to study the effective transmissivity of a plane‐walled fracture with circular cylindrical obstacles. Systematic numerical simulations show that the normalized effective transmissivity is predominantly dependent on f and α, and the effects of obstacle ordering are minor. The presented numerical results can be used by petroleum engineers for estimating transmissivities of propped fractures under in situ conditions. The model can also be applied to microfluidic systems and for deriving first‐order estimates of the effective transmissivity of rough‐walled, natural fractures with load‐bearing contact areas.
Seismic Attenuation and Stiffness Modulus Dispersion in Porous Rocks Containing Stochastic Fracture Networks
Authors: Hunziker Jürg , Favino Marco , Caspari Eva , Quintal Beatriz , Rubino J. Germán , Krause Rolf , Holliger Klaus
Published: January 2018

Understanding seismic attenuation and modulus dispersion mechanisms in fractured rocks can result in significant advances for the indirect characterization of such environments. In this paper, we study attenuation and modulus dispersion of seismic waves caused by fluid pressure diffusion (FPD) in stochastic 2‐D fracture networks, allowing for a state‐of‐the‐art representation of natural fracture networks by a power law length distribution. To this end, we apply numerical upscaling experiments consisting of compression and shear tests to our samples of fractured rocks. The resulting P and S wave attenuation and modulus dispersion behavior is analyzed with respect to the density, the length distribution, and the connectivity of the fractures. We focus our analysis on two manifestations of FPD arising in fractured rocks, namely, fracture‐to‐background FPD at lower frequencies and fracture‐to‐fracture FPD at higher frequencies. Our results indicate that FPD is sensitive not only to the fracture density but also to the geometrical characteristics of the fracture length distributions. In particular, our study suggests that information about the local connectivity of a fracture network could be retrieved from seismic data. Conversely, information about the global connectivity, which is directly linked to the effective hydraulic conductivity of the probed volume, remains rather difficult to infer.
The Variability and Interpretation of Earthquake Source Mechanisms in The Geysers Geothermal Field From a Bayesian Standpoint Based on the Choice of a Noise Model
Authors: Mustać Marija , Tkalčić Hrvoje , Burky Alexander L.
Published: January 2018

Moment tensor (MT) inversion studies of events in The Geysers geothermal field mostly focused on microseismicity and found a large number of earthquakes with significant non‐double‐couple (non‐DC) seismic radiation. Here we concentrate on the largest events in the area in recent years using a hierarchical Bayesian MT inversion. Initially, we show that the non‐DC components of the MT can be reliably retrieved using regional waveform data from a small number of stations. Subsequently, we present results for a number of events and show that accounting for noise correlations can lead to retrieval of a lower isotropic (ISO) component and significantly different focal mechanisms. We compute the Bayesian evidence to compare solutions obtained with different assumptions of the noise covariance matrix. Although a diagonal covariance matrix produces a better waveform fit, inversions that account for noise correlations via an empirically estimated noise covariance matrix account for interdependences of data errors and are preferred from a Bayesian point of view. This implies that improper treatment of data noise in waveform inversions can result in fitting the noise and misinterpreting the non‐DC components. Finally, one of the analyzed events is characterized as predominantly DC, while the others still have significant non‐DC components, probably as a result of crack opening, which is a reasonable hypothesis for The Geysers geothermal field geological setting.
Highly Efficient Nonlinear Optical Conversion in Waveguiding GaSe Nanoribbons with Pump Pulses Down to a Femto‐Joule Level
Authors: Liao Feng , Wang Yu , Peng Tao , Peng Jian , Gu Zhaoqi , Yu Huakang , Chen Tao , Yu Jiaxin , Gu Fuxing
Published: January 2018

Layered GaSe flakes have revealed strongest second‐harmonic (SH) generation among all the two‐dimensional (2D) atomic crystals measured up to now. However, the unique feature of physical atomic thickness at nanometer scale prevents their practical applications in efficient nonlinear optical conversion due to limited light–matter interaction length. In this work, high quality single‐crystal GaSe nanoribbons (NRs) are fabricated and demonstrated as waveguides with good performance. By taking advantage of the strong confinement and long interaction length of the waveguiding approach, significantly enhanced nonlinear light–matter interaction is observed in GaSe NRs. Based on transverse SH generation, a single GaSe NR‐configured optical auto‐correlator is constructed for ultrashort pulse characterization. Because of the large second‐order nonlinear susceptibility, high sensitivity down to few femto‐joule (fJ) is realized. To the best of our knowledge, this is the highest energy sensitivity among the reported nanoscale auto‐correlators. Such NR waveguides and devices are highly compatible with standard optical fiber systems. The presented results may enable the construction of future energy efficient nonlinear photonic circuitry, chips, and devices.
Sorption behavior of methylene blue and rhodamine B mixed dyes onto chitosan graft poly (acrylic acid‐co‐2‐acrylamide‐2‐methyl propane sulfonic acid) hydrogel
Authors: Tang Yaoji , He Tengteng , Liu Yangwenyi , Zhou Bin , Yang Rui , Zhu Linhui
Published: January 2018

Chitosan graft poly(acrylic acid‐co‐2‐acrylamide‐2‐methyl propane sulfonic acid) (CTS‐g‐P(AA‐co‐AMPS)) hydrogel is prepared and used to remove methylene blue (MB) and rhodamine B (RB) mixed dyes from aqueous solutions. The effect of adsorption conditions, including the initial concentrations of dye solutions, contact time, initial pH values, ionic strength, and the adsorbent dosage, on the adsorption capacities is investigated. The maximal adsorption capacity for MB and RB is 936.0 and 556.9 mg/g, respectively. The adsorption isotherms of the mixed dyes are discussed using the extended Langmuir (EL) and the extended Freundlich (EF) isotherm equations. It indicates that the adsorption of both dyes is in good agreement with the extended Freundlich isotherm. Meanwhile, the adsorption processes of both dyes are spontaneous. Adsorption kinetics is in accordance with the pseudo‐second‐order kinetic equation. It is concluded that the available adsorption sites are shared by both kinds of the dye molecules. The difference of the maximal adsorption capacities of the two dyes is due to their different affinity to the adsorbent.
Modularized Extracellular Vesicles: The Dawn of Prospective Personalized and Precision Medicine
Authors: Tao Shi‐Cong , Guo Shang‐Chun , Zhang Chang‐Qing
Published: January 2018

Extracellular vesicles (EVs) are ubiquitous nanosized membrane vesicles consisting of a lipid bilayer enclosing proteins and nucleic acids, which are active in intercellular communications. EVs are increasingly seen as a vital component of many biological functions that were once considered to require the direct participation of stem cells. Consequently, transplantation of EVs is gradually becoming considered an alternative to stem cell transplantation due to their significant advantages, including their relatively low probability of neoplastic transformation and abnormal differentiation. However, as research has progressed, it is realized that EVs derived from native‐source cells may have various shortcomings, which can be corrected by modification and optimization. To date, attempts are made to modify or improve almost all the components of EVs, including the lipid bilayer, proteins, and nucleic acids, launching a new era of modularized EV therapy through the “modular design” of EV components. One high‐yield technique, generating EV mimetic nanovesicles, will help to make industrial production of modularized EVs a reality. These modularized EVs have highly customized “modular design” components related to biological function and targeted delivery and are proposed as a promising approach to achieve personalized and precision medicine.
Stretchable Polymer Semiconductors for Plastic Electronics
Authors: Wang Ging‐Ji Nathan , Gasperini Andrea , Bao Zhenan
Published: January 2018

Conjugated polymers have evolved significantly in the past decade and have proven to be more than poorly conducting plastics. Instead, improved understanding has resulted in respectable charge‐carrier mobilities and power‐conversion efficiencies achieved by various donor‐acceptor‐type semiconducting polymers. However, their advantages in mechanical flexibility and deformability seem to have conflicting molecular design requirements from those for high charge‐carrier transporting properties. It is therefore a challenge to enhance the mechanical compliance of semiconducting polymers suitable for stretchable device applications. This progress report starts with a brief introduction to fracture mechanics and mechanical characterization techniques for thin polymer films, in order to consider the limitations and rationalization of current definition and parameters for stretchability. It then surveys different strategies that can be applied to improve the mechanical robustness and stretchability of polymer semiconductors, in particular focusing on molecular design aspects such as molecular weight and regioregularity, structural modifications in the polymer backbone and side chain, and postpolymerization modifications including blending and cross‐linking. Finally, directions for future development of next‐generation stretchable conjugated polymers are indicated.
Mimic the Photosystem II for Water Oxidation in Neutral Solution: A Case of Co3O4
Authors: Ni Bing , Wang Kai , He Ting , Gong Yue , Gu Lin , Zhuang Jing , Wang Xun
Published: January 2018

The photosystem II (PSII) in green plants exhibits marvelous oxygen production in neutral environments. However, artificially developed oxygen evolution catalysts (OECs) show much less activity, and the oxygen evolution reaction (OER) is now becoming a bottleneck in many energy‐related issues. Here, the PSII is mimicked to design an efficient OER system in neutral environments by introducing an oleylamine (OAm) organic layer to cap the Co3O4 OEC, and employing buffers as proton shuttles in the system. Consequently, the activity is largely enhanced. The current density can reach 10 mA cm−2 at an overpotential (η) of 390 mV in the best case in neutral environment. The turnover frequency is 0.0117 at η of 400 mV, almost the same as that in 1 m KOH solutions. The surface chemistry of the Co3O4 OEC indicates that the OAm can promote the activity. The reason that buffers as proton shuttles can greatly facilitate the reaction is ascribed to the proton‐coupled electron transfer process in the OER mechanism. These results may stimulate new perspectives on mimicking natural systems as well as new insights in electrocatalysis.
Enhanced Cyclability of Lithium–Oxygen Batteries with Electrodes Protected by Surface Films Induced via In Situ Electrochemical Process
Authors: Liu Bin , Xu Wu , Tao Jinhui , Yan Pengfei , Zheng Jianming , Engelhard Mark H. , Lu Dongping , Wang Chongmin , Zhang Ji‐Guang
Published: January 2018

Although the rechargeable lithium–oxygen (Li–O2) batteries have extremely high theoretical specific energy, the practical application of these batteries is still limited by the instability of their carbon‐based air‐electrode, Li metal anode, and electrodes, toward reduced oxygen species. Here a simple one‐step in situ electrochemical precharging strategy is demonstrated to generate thin protective films on both carbon nanotubes (CNTs), air‐electrodes and Li metal anodes simultaneously under an inert atmosphere. Li–O2 cells after such pretreatment demonstrate significantly extended cycle life of 110 and 180 cycles under the capacity‐limited protocol of 1000 mA h g−1 and 500 mA h g−1, respectively, which is far more than those without pretreatment. The thin‐films formed from decomposition of electrolyte during in situ electrochemical precharging processes in an inert environment, can protect both CNTs air‐electrode and Li metal anode prior to conventional Li–O2 discharge/charge cycling, where reactive reduced oxygen species are formed. This work provides a new approach for protection of carbon‐based air‐electrodes and Li metal anodes in practical Li–O2 batteries, and may also be applied to other battery systems.
Coupled Supercapacitor and Triboelectric Nanogenerator Boost Biomimetic Pressure Sensor
Authors: Zou Jingdian , Zhang Meng , Huang Jinrong , Bian Jie , Jie Yang , Willander Magnus , Cao Xia , Wang Ning , Wang Zhong Lin
Published: January 2018

With the fast development of supercapacitor and triboelectric nanogenerator (TENG), it is now possible to fabricate biomimetic pressure sensors with high flexibility and sustainability. Herein, an ultrathin supercapacitor is fabricated with the paper sheet and the solid electrolyte for storing energy generated by TENG. With a sandwich design, the triboelectrodes sandwiched within the two solid supercapacitors can not only store electrical energy by a wireless energy transfer mode but also help TENG imitate the receptor's unique characteristics by simultaneously measuring both static and dynamic pressures in a self‐driven mode. In addition, the voltage of the supercapacitor increases linearly with the vibration times, which hints that this integrated device also endows functions such as vibration counting and frequency computing. This work contributes to new strategies for making multifunctional biomimetic electronics that promote the development of artificial intelligence.
Solubilities of solid n‐alkanes in methane: Data analysis and models assessment
Authors: Campestrini Marco , Stringari Paolo
Published: January 2018

This article reviews the results of experiments underway since 1950 studying the solid solubility of n‐alkanes (from ethane up to n‐triacontane) in methane and the factors influencing the global phase equilibrium behavior of the related binary mixtures. The methodology used consists of a series of comparisons of data in the composition‐temperature and pressure‐temperature diagrams. The kind of global phase diagram of the binary mixtures of methane referred to in the present article is found to be dependent of the ratio between the triple‐point temperature of the generic n‐alkane and the critical‐point temperature of methane. The Peng‐Robinson (1976), Predictive Soave‐Redlich‐Kwong, and Predictive Peng‐Robinson (1978) equations of state have been applied and compared with respect to the calculation of bivariant, univariant, and invariant equilibrium data involving solid n‐alkanes in binary mixture with methane. The fugacities of the solid n‐alkanes have been calculated by means of the so‐called classic approach. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2219–2239, 2018
Synthesis and Chemical Transformations of Fluorosulfates
Authors: Revathi Lekkala , Ravindar Lekkala , Leng Jing , Rakesh Kadalipura Puttaswamy , Qin Hua‐Li
Published: January 2018

Fluorosulfates are readily available electrophiles that can be prepared from the reactions of phenol or alcohol derivatives with sulfuryl fluoride, fluorosulfonic acid, sulfuryl chloride fluoride, and fluorosulfonic anhydride. This Focus Review covers most of the synthetic strategies that have been reported for the construction of fluorosulfates, as well as their application as versatile building blocks in a variety of synthetic transformations, such as catalyzed amination, cross‐coupling, sulfur(VI) fluoride exchange, carbonylation, hydrolysis, alcoholysis, and as alternatives to organic halides or triflates in organic chemistry.
Rhodium‐Catalyzed Enantioselective Formal [4+1] Cycloaddition of Diazooxindoles and the Danishefsky Diene
Authors: Cao Fei , Hu Fang , Xie Qi‐Mei , Luo Gao‐Ya , Chu Wen‐Dao , He Long , Liu Quan‐Zhong
Published: January 2018

Optically enriched cyclopentenones are synthetically versatile molecules, and their rapid and efficient straightforward assembly from simple starting materials is highly desired. Herein, we report a rhodium‐catalyzed enantioselective formal [4+1] cycloaddition of diazooxindoles and the Danishefsky diene. The formation of cyclopentenones proceeds via ring expansion of the vinylcyclopropanes formed in situ via cyclopropanation. The optically and highly structurally enriched indoline spirocyclopentenone bearing an all‐carbon stereocenter was formed in a one‐pot, two‐step manner in good to excellent yields and enantioselectivities (up to 90 % ee).
Electrifying Organic Synthesis
Authors: Wiebe Anton , Gieshoff Tile , Möhle Sabine , Rodrigo Eduardo , Zirbes Michael , Waldvogel Siegfried R.
Published: January 2018

The direct synthetic organic use of electricity is currently experiencing a renaissance. More synthetically oriented laboratories working in this area are exploiting both novel and more traditional concepts, paving the way to broader applications of this niche technology. As only electrons serve as reagents, the generation of reagent waste is efficiently avoided. Moreover, stoichiometric reagents can be regenerated and allow a transformation to be conducted in an electrocatalytic fashion. However, the application of electroorganic transformations is more than minimizing the waste footprint, it rather gives rise to inherently safe processes, reduces the number of steps of many syntheses, allows for milder reaction conditions, provides alternative means to access desired structural entities, and creates intellectual property (IP) space. When the electricity originates from renewable resources, this surplus might be directly employed as a terminal oxidizing or reducing agent, providing an ultra‐sustainable and therefore highly attractive technique. This Review surveys recent developments in electrochemical synthesis that will influence the future of this area.
Design and synthesis of a magnetic hierarchical porous organic polymer: A new platform in heterogeneous phase‐transfer catalysis
Authors: Mouradzadegun Arash , Ganjali Mohammad Reza , Mostafavi Mahsa Alsadat
Published: January 2018

Recyclable phase transfer catalysts containing magnetic nanoparticles (MNPs) have been known as a major trend towards sustainable catalysts. In this study, a novel class of magnetic porous polymer on the basis of calix[4]resorcinarene was synthesized starting from silica‐coated Fe3O4 core‐shell nanoparticles. This compound was found as an efficient phase transfer catalyst to the conversion of benzyl halides into benzyl azides and cyanides in good yields. The catalyst could be used at least for five consecutive cycles without appreciable loss in the catalytic activity.
Fe3O4/MIL‐101(Fe) nanocomposite as an efficient and recyclable catalyst for Strecker reaction
Authors: Mostafavi Mohammad Mahdi , Movahedi Farnaz
Published: January 2018

A highly porous metal‐organic framework, MIL‐101(Fe), was prepared by a solvothermal method in the presence of amino‐modified Fe3O4@SiO2 nanoparticles, in order to achieve Fe3O4/MIL‐101(Fe) nanocomposite, which was characterized by XRD, FT‐IR, SEM, TEM, BET, and VSM. This hybrid magnetic nanocomposite was employed as heterogeneous catalyst for α‐amino nitriles synthesis through three‐component condensation reaction of aldehydes (ketones), amines, and trimethylsilyl cyanide in EtOH, at room temperature. The recoverability and reusability was admitted for the heterogeneous magnetic catalyst; no significant reduction of catalytic activity was observed even after five consecutive reaction cycles.
Evaluation of UiO‐66 metal organic framework as an effective sorbent for Curcumin's overdose
Authors: Molavi Hossein , Zamani Mostafa , Aghajanzadeh Mozhgan , Kheiri Manjili Hamidreza , Danafar Hossein , Shojaei Akbar
Published: January 2018

Metal organic frameworks (MOFs) UiO‐66 (UiO stands for University of Oslo) and NH2‐UiO‐66 were prepared and characterized as sorbent (antidotal agents) for curcumin (CUR) adsorption. The structure of products were characterized by X‐ray powder diffraction (XRD), Field emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA), Attenuated Total Reflectance‐Fourier transform infrared spectroscopy (ATR‐FTIR), and N2 adsorption–desorption measurements. FESEM showed NH2‐UiO‐66 displayed symmetrical crystals with triangular base pyramid morphology, with the particle size around 100 nm and uniform size distribution. Adsorption capacities of CUR/MOFs with different mass ratios in the feed were investigated in the present study, and this investigation revealed that when the CUR/MOFs with mass ratio was around 0.4, the absorption capacity of NH2‐UiO‐66 had tended to maximum. Although, functionalization reduced the specific surface area and free volume, introducing polar amine groups could improve the affinity of NH2‐UiO‐66 respect to CUR. Kinetic studies showed that the kinetic data are well fitted with the pseudo‐ second‐order model. MTT assay revealed that MOFs at the concentration range of 0–560 μg/ml had no cytotoxic effect on the Human Foreskin Fibroblast normal cell line (HFF‐2). These results suggest that these MOFs could be safe as sorbent for adsorb CUR from the body.
Design, synthesis, and pharmacological evaluation of fluorinated azoles as anti‐tubercular agents
Authors: Gholap Somnath , Tambe Macchindra , Nawale Laxman , Sarkar Dhiman , Sangshetti Jaiprakash , Damale Manoj
Published: January 2018

Design, synthesis, and biological screening of 2,2‐dimethyl‐2,3‐dihydrobenzofuran tethered 1,3,4‐oxadiazole derivatives as anti‐tubercular agents were described. The synthesis of the target compounds was conducted by a series of reaction schemes. All the synthesized compounds were characterized by IR, 1H NMR, 13C NMR, and mass spectrometry. The therapeutic potential of the synthesized compounds was confirmed by molecular docking studies. Among the synthesized compounds, 12a, 12c, 12d, 12e, 12g, and 12j were found to be more active against non‐replicating than against replicating cultures of Mycobacterium tuberculosis H37Ra ex vivo and in vitro. These compounds exhibit minimum inhibitory concentration (MIC) values in the range of 2.31–23.91 μg/mL. The cytotoxicity study was conducted against the cell lines THP‐1, A549 and PANC‐1, and the compounds were observed to be non‐toxic to host cells. Molecular docking was conducted with InhA (FabI/ENR) and suggested the antimycobacterial potential of the synthesized compounds. The investigation presented here was found to be adventitious for the development of new therapeutic agents against Mycobacterium infection.
The Attraction Effect in Experience‐based Decisions
Authors: Hadar Liat , Danziger Shai , Hertwig Ralph
Published: January 2018

Previous demonstrations of the attraction effect were limited to explicitly described attribute values (including numerically indexed attributes, such as gambles' outcomes and their likelihoods, or perceptual attributes, such as rectangles' height and width). However, in many real‐life decisions, such as the choice of a preferred grocer, people decide based on their past experience with the options' attributes (e.g., the frequency and magnitude of product discounts over time). We examine whether the attraction effect extends from description‐based to experience‐based choice between gambles. Our results demonstrate that the attraction effect exists but is less prevalent in experience‐based than in description‐based choice. This is because the dominance relationship, necessary for the attraction effect to occur, is more difficult to recognize in experience‐based choice. Yet, when dominance is recognized, people may use it to guide difficult trade‐off choices. We discuss practical implications. Copyright © 2018 John Wiley & Sons, Ltd.
Preparation and application of sulfated xylan as a flocculant for dye solution
Authors: Liu Zhongming , Xu Dingding , Kong Fangong , Wang Shoujuan , Yang Guihua , Fatehi Pedram
Published: January 2018

The main purpose of this study is to explore the sulfation of xylan to produce an anionic flocculant, sulfated xylan, for removing ethyl violet dye from simulated dye solutions. In this work, xylan was sulfated with chlorosulfonic acid in N, N‐dimethylformamide solvent and the reaction conditions were optimized using a response surface methodology. It was observed that the maximum degree of substitution of 1.1 was obtained for sulfated xylan under the conditions of 3.71 chlorosulfonic acid/xylan molar ratio, 70°C and 7 h reaction time. The resulting sulfated xylan had a charge density of −3.12 mmol/g and molecular weight (Mw) of 22,300 g/mol. Furthermore, elemental and thermogravimetric analyses, Fourier transform infrared spectroscopy and proton nuclear magnetic resonance (1H‐NMR) confirmed the sulfation of xylan. The application of sulfated xylan as a flocculant for decolorizing the simulated ethyl violet dye wastewater was studied. The results indicated that 97% of dye was removed from 50 mg/L dye solution at the sulfated concentration of 175 mg/L and pH 9, but unmodified xylan was ineffective in flocculating and removing dye segments. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:529–536, 2018
Highly Oxygen Non‐Stoichiometric BaSc0.25Co0.75O3‐δ as a High‐Performance Cathode for Intermediate‐Temperature Solid Oxide Fuel Cells
Authors: Liu Bo , Sunarso Jaka , Zhang Yuan , Yang Guangming , Zhou Wei , Shao Zongping
Published: January 2018

Lowering the operating temperature of solid oxide fuel cells (SOFCs) is highly desirable to reduce the cost and increase the lifetime, which relies upon the development of a cathode component with high oxygen reduction reaction (ORR) activity at a lower temperature. Herein, we report the characterization of high‐performance BaScxCo1‐xO3‐δ (x=0, 0.125, 0.25, and 0.375) perovskite SOFC cathodes. Unlike BaCoO3‐δ, which adopts 2H‐hexagonal perovskite structure, the replacement of 25 mol % of Co with Sc stabilizes the cubic structure, which also leads to the significant reduction in area specific resistances and their activation energies between 650 and 500 °C (for BaSc0.25Co0.75O3‐δ) relative to the non‐doped BaCoO3‐δ. In this temperature range, BaSc0.25Co0.75O3‐δ displayed a remarkably high ORR activity compared to Ba0.5Sr0.5Co0.8Fe0.2O3‐δ (BSCF), the current cathode benchmark. We attribute such superior ORR performance to the higher oxygen non‐stoichiometries of BaSc0.25Co0.75O3‐δ relative to BSCF, which also translates to the higher oxygen bulk diffusion and surface exchange coefficients for the former compared to the latter. As a result, a single fuel cell based on an anode‐supported 20 μm thick samarium‐doped ceria electrolyte and BaSc0.25Co0.75O3‐δ cathode achieved a very high peak power density of 1723 mW cm−2 at 650 °C. We also demonstrated the possibility to increase the ORR activity of the BaSc0.25Co0.75O3‐δ cathode by impregnation of a low amount of silver.
A rapid, maskless 3D prototyping for fabrication of capillary circuits: Toward urinary protein detection
Authors: Yan Sheng , Zhu Yuanqing , Tang Shi‐Yang , Li Yuxing , Zhao Qianbin , Yuan Dan , Yun Guolin , Zhang Jun , Zhang Shiwu , Li Weihua
Published: January 2018

Proteinuria is an established risk marker for progressive renal function loss and patients would significantly benefit from a point‐of‐care testing. Although extensive work has been done to develop the microfluidic devices for the detection of urinary protein, they need the complicated operation and bulky peripherals. Here, we present a rapid, maskless 3D prototyping for fabrication of capillary fluidic circuits using laser engraving. The capillary circuits can be fabricated in a short amount of time (<10 min) without the requirements of clean‐room facilities and photomasks. The advanced capillary components (e.g., trigger valves, retention valves and retention bursting valves) were fabricated, enabling the sequential liquid delivery and sample‐reagent mixing. With the integration of smartphone‐based detection platform, the microfluidic device can quantify the urinary protein via a colorimetric analysis. By eliminating the bulky and expensive equipment, this smartphone‐based detection platform is portable for on‐site quantitative detection.
Ba‐doping to Improve the Cycling Stability of LiNi0.5Mn0.5O2 Cathode Materials for Batteries Operating at High Voltage
Authors: Liu Zeyu , Zheng Hong , Tan Li , Yuan Silan , Yin Haiyan
Published: January 2018

LiNi0.5−xBaxMn0.5O2 (x=0, 0.03, 0.05, 0.08) samples were prepared by using a combination of co‐precipitation and solid‐state methods. All of the cathode materials were analyzed by inductively coupled plasma mass spectrometry (ICP‐MS), X‐ray diffraction (XRD), Rietveld refinement, X‐ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). The results of them show that we have successfully prepared the target materials, and Ba‐doping can keep the structure stable and lower Li/Ni cation mixing. In addition, Ba‐doping does not change the structure, the chemical states, or the morphology of LiNi0.5Mn0.5O2. The electrochemical properties of the samples were explored systematically by rate performance and charge–discharge tests at room temperature and high temperature. The performances of the cathode materials indicate that 5 mol % Ba‐doping of LiNi0.5Mn0.5O2 can improve the capacity retention at 0.2 C by approximately 41 % and 13 %, at room temperature and 60 °C, respectively. in the range between 2.5 and 4.8 V. In addition, the 5 mol % Ba‐doped material shows better rate performances than that of the un‐doped material, especially at higher current densities. Cyclic voltammetry (CV) and electrochemical impedance spectroscope (EIS) tests were used to analyze the reason for the improved electrochemical properties, which may be attributed to lower Li/Ni cation mixing, higher structural stability, lower polarization, and lower charge transfer resistance.
Development of dementia in patients with femoral neck fracture who experience postoperative delirium—A three‐year follow‐up study
Authors: Olofsson B. , Persson M. , Bellelli G. , Morandi A. , Gustafson Y. , Stenvall M.
Published: January 2018

Objectives

It remains unclear to what extent postoperative delirium (POD) affects the incidence of dementia in hip fracture patients, and the methods used to detect delirium and dementia require validation. The aim of this study was to investigate the development of dementia within 3 years of femoral neck fracture repair surgery, with a focus on POD as a potential predictive factor.

Methods

Patients were assessed for cognition, delirium, depression, psychological well‐being, and nutritional status during their hospitalization as well as 4, 12, and 36 months after the operation. Logistic regression models were used to analyse factors associated with POD and factors associated with the development of dementia.

Results

The study sample consisted of 135 patients without a history of dementia, of whom 20 (14.8%) were delirious preoperatively and 75 (55.5%) postoperatively. Three years after their operations, 43/135 patients (31.8%) were diagnosed with dementia. A greater portion of patients diagnosed with dementia (39/43, 90.6%) than patients with no dementia (36/92, 39.1%) were included among the 75 patients who had experienced POD (P < 0.001). In a logistic regression model, after adjustment for covariates (age, sex, diabetes, delirium pre‐and postoperatively, hyperactive delirium, days with delirium, urinary tract infection, and Mini Nutritional Assessment score), POD emerged an independent predictor for the development of new dementia (odds ratio, 15.6; 95% confidence interval, 2.6–91.6) within 3 years after the operation.

Conclusion

Geriatric hip fracture patients who exhibit POD should be monitored closely for the development of dementia.