bluuebunny/crossref_metadata_2025 huggingface dataset:
Los desafíos del sorteo a la democracia, los desafíos de la democracia al sorteo
Authors: Moreno Pestaña José Luis
Published: January 2018

En este artículo se estudian las contribuciones presentadas en el número monográfico sobre Sorteo y democracia de Daimon-Revista internacional de Filosofía (nº 72, sept-dic. 2017). El texto explica, primero, cómo el sorteo nace de otro modo de abordar la tradición en historia de las ideas y las instituciones republicanas y demoráticas. En segundo lugar, el artículo muestra, siempre con este número de la revista como referente, cómo el sorteo abre un nuevo campo de debates acerca de cómo profundizar nuestras prácticas democráticas. 
Rapports sociaux de sexe dans la recherche biomédicale : une lecture de la production de savoirs dans les publications féministes anglophones
Authors: Flores Espínola Artemisa
Published: January 2018

L’analyse féministe a porté une attention particulière aux sciences explorant la sexualité ou le comportement des sexes comme les sciences biomédicales. Cet article étudie les publications féministes anglophones sur la recherche biomédicale, en se plaçant dans la perspective des deux objectifs qui fondent le projet épistémologique féministe : d’une part, établir les apports de la critique féministe à la mise en évidence du sexisme et de l’androcentrisme dans la pratique scientifique ; d’autre part, proposer et soutenir des pratiques scientifiques féministes qui engagent à la libération des femmes, dans une perspective d’égalité sociale et politique, et ce, en expliquant comment de telles propositions moralement et politiquement engagées sont à même de permettre la production d’un nouveau mode de connaissance (Anderson, 1995). Après avoir retracé les origines et la nature des critiques féministes « réformistes », ce texte s’intéresse aux critiques « révolutionnaires » en mobilisant les épistémologies sociales, notamment celle de Longino. Comment les « épistémologies féministes » participent-elles d’une transformation des pratiques scientifiques (pour les sciences sociales comme pour les sciences biomédicales) et partant, d’une nouvelle forme de connaissance ?
Des brèches dans le mur : inégalités sociales, sociologie et savoirs d’expérience
Authors: McAll Christopher
Published: January 2018

Les sociétés inégalitaires doivent se protéger du regard critique de ceux et celles qui s’en perçoivent comme les victimes. Présenter ces inégalités comme inévitables et justes devient alors d’autant plus nécessaire qu’elles risquent d’engendrer un ressentiment qui peut déclencher une demande de changement social radical. Comment la sociologie peut-elle maintenir une distance critique vis-à-vis d’arguments qui cherchent à légitimer les inégalités, afin de participer à la production d’une société plus égalitaire ? Ce texte suggère des brèches pour sortir des espaces de connaissance emmurés qui protègent les inégalités. Il s’agit, dans un premier temps, de revenir sur les approches qui voient dans les inégalités une condition relevant des individus eux-mêmes. Par la suite, sont examinées les perspectives selon lesquelles les inégalités sociales sont perçues comme découlant de rapports entre groupes sociaux, chaque type de rapport étant associé à la production d’un certain type de savoir racisant ou naturalisant. Dans un troisième temps, est abordé le rôle des sciences sociales dans la construction des « murs » qui protègent les inégalités sociales. Est proposée alors une lecture critique de l’État technobureaucratique, conçu comme contribuant à la production des inégalités. Le texte se termine par un appel pour une sociologie qui s’allie avec d’autres acteurs du monde social, reconnaisse les savoirs fondés sur l’expérience de vie et d’intervention et participe à la transformation de l’État social et de sa capacité de produire une société plus égalitaire et plus libre.
Les enjeux méthodologiques et épistémologiques du croisement des savoirs entre personnes en situation de pauvreté, praticien.ne.s et universitaires
Authors: Carrel Marion , Loignon Christine , Boyer Sophie , De Laat Marianne
Published: January 2018

À partir de la recherche en croisement des savoirs ÉQUIsanTÉ, menée à Montréal entre chercheures en santé, personnes en situation de pauvreté et professionnel.le.s de la santé, l’article (élaboré collectivement) explore quelques-unes des questions théoriques, épistémologiques et éthiques soulevées par ce mode alternatif de production de connaissances. Parmi les questions les plus débattues sur le plan méthodologique figurent la non-mixité partielle ainsi que le statut et le rôle des associations qui militent aux côtés des personnes en situation de pauvreté. Sur le plan épistémologique, nous avons également analysé la portée d’une telle démarche en matière de connaissances et ses effets en matière d’émancipation. L’article propose ainsi de contribuer au débat scientifique sur ce que l’on pourrait appeler une « épistémologie post-pauvreté », en écho aux épistémologies féministes et postcolonialistes.
Codification and Legal Sources in the Albanian Legal System: Comparative Approach to Legal Systems
Authors: Olldashi Enkeleda
Published: January 2018

The civil law system entered the codification path during the 19th century, enabling the creation of uniformity, such as drafting a civil code and building a new (national) identity. The structure of the code suggests that it provides a comprehensive, internally coherent set of rules for private law. The adopted civil codes secure lawyers a systematic and coherent foundation for the legal system and legal reasoning. Codification allowed laws to be in an easily identified document easily. Traditionally, the civil law system has been subject to several codification and consolidation processes during different periods in time, influenced from political, social or economic reforms. In Albania after the proclamation of the Monarchy, work began on the preparation of various codes, with the crucial one being the Civil Code. The first Albanian Civil Code entered in force on the 1st of April 1929. This process was the first step for the Albanian Legislator to compare the secularity of the European legal framework to that of the Ottoman Empire. In 1991, the end of the communist era in Albania was marked by bringing the transformation of the economy into a market-oriented system and the creation of a legal system that protected the right of private property. The Albanian system as a continental system has developed a system based on systematic approach to laws, a procedure known as dogmatic approach. It has created an internal system of laws based on generally codified norms and principles. The purpose of this paper is to explain the impact of political, social or economic reforms in the codification process and the nature of legal sources in Albania.
Stromule extension along microtubules coordinated with actin-mediated anchoring guides perinuclear chloroplast movement during innate immunity
Authors: Kumar Amutha Sampath , Park Eunsook , Nedo Alexander , Alqarni Ali , Ren Li , Hoban Kyle , Modla Shannon , McDonald John H , Kambhamettu Chandra , Dinesh-Kumar Savithramma P , Caplan Jeffrey Lewis
Published: January 2018

Dynamic tubular extensions from chloroplasts called stromules have recently been shown to connect with nuclei and function during innate immunity. We demonstrate that stromules extend along microtubules (MTs) and MT organization directly affects stromule dynamics since stabilization of MTs chemically or genetically increases stromule numbers and length. Although actin filaments (AFs) are not required for stromule extension, they provide anchor points for stromules. Interestingly, there is a strong correlation between the direction of stromules from chloroplasts and the direction of chloroplast movement. Stromule-directed chloroplast movement was observed in steady-state conditions without immune induction, suggesting it is a general function of stromules in epidermal cells. Our results show that MTs and AFs may facilitate perinuclear clustering of chloroplasts during an innate immune response. We propose a model in which stromules extend along MTs and connect to AF anchor points surrounding nuclei, facilitating stromule-directed movement of chloroplasts to nuclei during innate immunity.
Inhibition of oxidative stress in cholinergic projection neurons fully rescues aging-associated olfactory circuit degeneration in Drosophila
Authors: Hussain Ashiq , Pooryasin Atefeh , Zhang Mo , Loschek Laura F , La Fortezza Marco , Friedrich Anja B , Blais Catherine-Marie , Üçpunar Habibe K , Yépez Vicente A , Lehmann Martin , Gompel Nicolas , Gagneur Julien , Sigrist Stephan J , Grunwald Kadow Ilona C
Published: January 2018

Loss of the sense of smell is among the first signs of natural aging and neurodegenerative diseases such as Alzheimer’s and Parkinson’s. Cellular and molecular mechanisms promoting this smell loss are not understood. Here, we show that Drosophila melanogaster also loses olfaction before vision with age. Within the olfactory circuit, cholinergic projection neurons show a reduced odor response accompanied by a defect in axonal integrity and reduction in synaptic marker proteins. Using behavioral functional screening, we pinpoint that expression of the mitochondrial reactive oxygen scavenger SOD2 in cholinergic projection neurons is necessary and sufficient to prevent smell degeneration in aging flies. Together, our data suggest that oxidative stress induced axonal degeneration in a single class of neurons drives the functional decline of an entire neural network and the behavior it controls. Given the important role of the cholinergic system in neurodegeneration, the fly olfactory system could be a useful model for the identification of drug targets.
The French press: a repeatable and high-throughput approach to exercising zebrafish (Danio rerio)
Authors: Usui Takuji , Noble Daniel W.A. , O’Dea Rose E. , Fangmeier Melissa L. , Lagisz Malgorzata , Hesselson Daniel , Nakagawa Shinichi
Published: January 2018

Zebrafish are increasingly used as a vertebrate model organism for various traits including swimming performance, obesity and metabolism, necessitating high-throughput protocols to generate standardized phenotypic information. Here, we propose a novel and cost-effective method for exercising zebrafish, using a coffee plunger and magnetic stirrer. To demonstrate the use of this method, we conducted a pilot experiment to show that this simple system provides repeatable estimates of maximal swim performance (intra-class correlation [ICC] = 0.34–0.41) and observe that exercise training of zebrafish on this system significantly increases their maximum swimming speed. We propose this high-throughput and reproducible system as an alternative to traditional linear chamber systems for exercising zebrafish and similarly sized fishes.
High Angular Resolution Measurements of the Anisotropy of Reflectance of Sea Ice and Snow
Authors: Goyens C. , Marty S. , Leymarie E. , Antoine D. , Babin M. , Bélanger S.
Published: January 2018

We introduce a new method to determine the anisotropy of reflectance of sea ice and snow at spatial scales from 1 m2 to 80 m2 using a multispectral circular fish‐eye radiance camera (CE600). The CE600 allows measuring radiance simultaneously in all directions of a hemisphere at a 1° angular resolution. The spectral characteristics of the reflectance and its dependency on illumination conditions obtained from the camera are compared to those obtained with a hyperspectral field spectroradiometer manufactured by Analytical Spectral Device, Inc. (ASD). Results confirm the potential of the CE600, with the suggested measurement setup and data processing, to measure commensurable sea ice and snow hemispherical‐directional reflectance factor, HDRF, values. Compared to the ASD, the reflectance anisotropy measured with the CE600 provides much higher resolution in terms of directional reflectance (N = 16,020). The hyperangular resolution allows detecting features that were overlooked using the ASD due to its limited number of measurement angles (N = 25). This data set of HDRF further documents variations in the anisotropy of the reflectance of snow and ice with the geometry of observation and illumination conditions and its spectral and spatial scale dependency. Finally, in order to reproduce the hyperangular CE600 reflectance measurements over the entire 400–900 nm spectral range, a regression‐based method is proposed to combine the ASD and CE600 measurements. Results confirm that both instruments may be used in synergy to construct a hyperangular and hyperspectral snow and ice reflectance anisotropy data set.
Fluid Migration in a Subducting Viscoelastic Slab
Authors: Morishige M. , van Keken P. E.
Published: January 2018

Metamorphic dehydration reactions in a subducting slab release fluids that trigger arc volcanism and are thought to be responsible for intermediate‐depth seismicity. The fluid flow from the source is controlled by buoyancy and compaction pressure which is modified by viscous and elastic effects. In this paper, we investigate how fluid migrates in viscoelastic slab by using 2‐D and 3‐D numerical models based on a theory of two‐phase flow. When bulk viscosity is sufficiently low, viscosity plays a dominant role and fluid goes up almost vertically soon after its release producing porosity waves. When a higher bulk viscosity is assumed, a large amount of fluid is trapped in a high porosity region produced by the fluid source and migrates along the source except for a case where the ratio of permeability (K) to fluid viscosity (μ) is relatively low. We also find that porosity increases in the deeper part of the fluid source in cases with intermediate and low values of
. In 3‐D, fluid focusing occurs where the slab bends away from the trench causing a local increase in porosity and compaction pressure. These findings may help us explain several types of observations in subduction zones including slow earthquakes at the plate interface, low seismic wave velocities in the oceanic crust, double seismic zones in the slab, and shallow subduction angle at the bend of the slab.
Crystallographic Preferred Orientation of Olivine in Sheared Partially Molten Rocks: The Source of the “a‐c Switch”
Authors: Qi Chao , Hansen Lars N. , Wallis David , Holtzman Benjamin K. , Kohlstedt David L.
Published: January 2018

To investigate the mechanism that produces the crystallographic preferred orientations (CPO) characteristic of sheared partially molten rocks of mantle composition, we analyzed the microstructures of samples of olivine plus 7% basaltic melt deformed in torsion to shear strains as large as
13.3. Electron backscattered diffraction (EBSD) observations reveal a CPO characterized by a weak a‐c girdle in the shear plane that develops by
4. This CPO, which exhibits a slightly stronger alignment of [001] than [100] axes in the shear direction, changes little in both strength and distribution with increasing stress and with increasing strain. Furthermore, it is significantly weaker than the CPO observed for dry, melt‐free olivine aggregates. Orientation maps correlated with grain shape measurements from tangential, radial, and transverse sections indicate that olivine grains are longer along [001] axes than along [100] axes and shortest along [010] axes. This morphology is similar to that of olivine grains in a mafic melt. We conclude that the weak a‐c girdle observed in sheared partially molten rocks reflects contributions from two processes. Due to their shape‐preferred orientation (SPO), grains rotate to align their [001] axes parallel to the flow direction. At the same time, dislocation glide on the (010)[100] slip system rotates [100] axes into the flow direction. The presence of this CPO in partially molten regions of the upper mantle significantly impacts the interpretation of seismic anisotropy and kinematics of flow.
Large‐Amplitude Extremely Low Frequency Hiss Waves in Plasmaspheric Plumes
Authors: Su Zhenpeng , Liu Nigang , Zheng Huinan , Wang Yuming , Wang Shui
Published: January 2018

Whistler‐mode extremely low frequency hiss emissions commonly exist in the plasmasphere and the plasmaspheric plume and contribute to the precipitation loss of the radiation belt electrons. How these hiss waves are generated remains a critical unanswered question. Here we report the large‐amplitude (up to 1.5 nT) hiss waves in the plasmaspheric plumes, nearly an order of magnitude stronger than previous observations. These waves are found to propagate toward higher latitudes, and the corresponding frequency dependence of wave power can be qualitatively (but not quantitatively) explained by the modeled linear instability of hot electrons near the equator. At the high‐frequency end of hiss spectra, the discrete rising tones are shown to emerge, similar to the situation of whistler‐mode chorus in the plasmatrough. These data and modeling suggest that these large‐amplitude hiss waves were generated within the plasmaspheric plume probably through a combination of linear and nonlinear instabilities of hot electrons.
EUV Irradiance Inputs to Thermospheric Density Models: Open Issues and Path Forward
Authors: Vourlidas A. , Bruinsma S.
Published: January 2018

One of the objectives of the NASA Living With a Star Institute on “Nowcasting of Atmospheric Drag for low Earth orbit (LEO) Spacecraft” was to investigate whether and how to increase the accuracy of atmospheric drag models by improving the quality of the solar forcing inputs, namely, extreme ultraviolet (EUV) irradiance information. In this focused review, we examine the status of and issues with EUV measurements and proxies, discuss recent promising developments, and suggest a number of ways to improve the reliability, availability, and forecast accuracy of EUV measurements in the next solar cycle.
Synthesis of Nanostructured PbO@C Composite Derived from Spent Lead‐Acid Battery for Next‐Generation Lead‐Carbon Battery
Authors: Hu Yuchen , Yang Jiakuan , Hu Jingping , Wang Junxiong , Liang Sha , Hou Huijie , Wu Xu , Liu Bingchuan , Yu Wenhao , He Xiong , Kumar R. Vasant
Published: January 2018

Lead‐carbon batteries could provide better performance on high‐rate partial‐state‐of‐charge (HRPSoC) cycles than lead‐acid batteries (LABs), making them promising for the new‐generation of hybrid electric vehicles. The addition of carbon allotropes to the negative active material (NAM) could induce a significant improvement to the battery performance. Herein, an environmentally friendly strategy is demonstrated to prepare lead oxide and carbon (PbO@C) composite by pyrolyzing the lead citrate precursor derived from the spent lead paste of LABs. When the PbO@C composite is used as an additive to the NAM of lead‐carbon batteries, the utilization efficiency of the NAM is improved from 56.9% to 72.5%, and the cycle life of the cell in HRPSoC is tremendously extended by four times compared with the control one. The enhancement in battery performance is attributed to the hydrophilic carbon in the composite, which acts as a 3D electroosmotic pump facilitating electrolyte diffusion, and hindering the tendency to excess sulfation during the HRPSoC operation. This proposed research provides a sustainable and scalable strategy to recycle the discarded/spent LABs into high‐performance lead‐carbon batteries.
2D WC/WO3 Heterogeneous Hybrid for Photocatalytic Decomposition of Organic Compounds with Vis–NIR Light
Authors: Wang Song Ling , Zhu Ye , Luo Xin , Huang Yun , Chai Jianwei , Wong Ten It , Xu Guo Qin
Published: January 2018

Developing catalysts to improve charge‐carrier transfer and separation is critical for efficient photocatalytic applications driven by low‐energy photons. van der Waals stacking of 2D materials has opened up opportunities to engineer heteromaterials for strong interlayer excitonic transition. However, fabrication of 2D heteromaterials with clean and seamless interfaces remains challenging. Here, a 2D tungsten carbide/tungsten trioxide (WC/WO3) heterogeneous hybrid in situ synthesized by a chemical engineering method has been reported. The hybrid comprises of layer‐by‐layer stacked WC and WO3 monolayers. The WC and specific interfacial interfaces between the WC and WO3 layers exhibit synergetic effects, promoting interfacial charge transfer and separation. Binderless WC performing platinum‐like behavior works as a potential substitute for noble metals and accelerates multielectron oxygen reduction, consequently speeding up the photocatalytic decomposition of organic compounds over the WO3 catalyst. The specific interfacial interaction between WC and WO3 layers potentially improves interfacial charge transfer from conduction band of WO3 to WC. In the absence of noble metals, the WC/WO3 hybrid as a catalyst exhibits distinct decomposition of organic compounds with vis–NIR light (λ = 400–800 nm). This finding provides a cost‐effective approach to capture low‐energy photons in environmental remediation applications.
Multiwalled Carbon Nanotubes Induced Hypotension by Regulating the Central Nervous System
Authors: Ma Xiaowei , Zhong Lin , Guo Hongbo , Wang Yifeng , Gong Ningqiang , Wang Yuqing , Cai Jun , Liang Xing‐Jie
Published: January 2018

Cardiovascular disease is the leading cause of death worldwide. Normal blood pressure is very important for overall well‐being and unexpected decrease in blood pressure may cause many detrimental consequences. The attractive properties of multiwalled carbon nanotubes (MWCNTs) entice their usage in many cutting edge brain‐specific therapies. However, the effects of MWCNTs to the central nervous system are not fully understood. In this work, the authors report that carbon nanotubes can significantly cause blood pressure to fall down when introduced into the brain at very low dosage. It is found that MWCNTs induce increased expression of neuronal nitric oxide synthase in the medulla cardiovascular center, which consequently attenuate sympathetic nerve activity and cause decrease in blood pressure and heart rate. In addition, MWCNTs promote acetylation and nuclear translocation of nuclear factor‐κB in brain cells. This work illustrates how CNTs can potentially change blood pressure by interrupting the central nervous system and is significant to the biomedical applications of CNTs.
A Facile Method to Fabricate Anisotropic Hydrogels with Perfectly Aligned Hierarchical Fibrous Structures
Authors: Mredha Md. Tariful Islam , Guo Yun Zhou , Nonoyama Takayuki , Nakajima Tasuku , Kurokawa Takayuki , Gong Jian Ping
Published: January 2018

Natural structural materials (such as tendons and ligaments) are comprised of multiscale hierarchical architectures, with dimensions ranging from nano‐ to macroscale, which are difficult to mimic synthetically. Here a bioinspired, facile method to fabricate anisotropic hydrogels with perfectly aligned multiscale hierarchical fibrous structures similar to those of tendons and ligaments is reported. The method includes drying a diluted physical hydrogel in air by confining its length direction. During this process, sufficiently high tensile stress is built along the length direction to align the polymer chains and multiscale fibrous structures (from nano‐ to submicro‐ to microscale) are spontaneously formed in the bulk material, which are well‐retained in the reswollen gel. The method is useful for relatively rigid polymers (such as alginate and cellulose), which are susceptible to mechanical signal. By controlling the drying with or without prestretching, the degree of alignment, size of superstructures, and the strength of supramolecular interactions can be tuned, which sensitively influence the strength and toughness of the hydrogels. The mechanical properties are comparable with those of natural ligaments. This study provides a general strategy for designing hydrogels with highly ordered hierarchical structures, which opens routes for the development of many functional biomimetic materials for biomedical applications.
Lipid and Nucleic Acid Chemistries: Combining the Best of Both Worlds to Construct Advanced Biomaterials
Authors: Baillet Julie , Desvergnes Valérie , Hamoud Aladin , Latxague Laurent , Barthélémy Philippe
Published: January 2018

Hybrid synthetic amphiphilic biomolecules are emerging as promising supramolecular materials for biomedical and technological applications. Herein, recent progress in the field of nucleic acid based lipids is highlighted with an emphasis on their molecular design, synthesis, supramolecular properties, physicochemical behaviors, and applications in the field of health science and technology. In the first section, the design and the study of nucleolipids are in focus and then the glyconucleolipid family is discussed. In the last section, recent contributions of responsive materials involving nucleolipids and their use as smart drug delivery systems are discussed. The supramolecular materials generated by nucleic acid based lipids open new challenges for biomedical applications, including the fields of medicinal chemistry, biosensors, biomaterials for tissue engineering, drug delivery, and the decontamination of nanoparticles.
Real‐Time and High‐Resolution Bioimaging with Bright Aggregation‐Induced Emission Dots in Short‐Wave Infrared Region
Authors: Qi Ji , Sun Chaowei , Zebibula Abudureheman , Zhang Hequn , Kwok Ryan T. K. , Zhao Xinyuan , Xi Wang , Lam Jacky W. Y. , Qian Jun , Tang Ben Zhong
Published: January 2018

Fluorescence imaging in the spectral region beyond the conventional near‐infrared biological window (700–900 nm) can theoretically afford high resolution and deep tissue penetration. Although some efforts have been devoted to developing a short‐wave infrared (SWIR; 900–1700 nm) imaging modality in the past decade, long‐wavelength biomedical imaging is still suboptimal owing to the unsatisfactory materials properties of SWIR fluorophores. Taking advantage of organic dots based on an aggregation‐induced emission luminogen (AIEgen), herein microscopic vasculature imaging of brain and tumor is reported in living mice in the SWIR spectral region. The long‐wavelength emission of AIE dots with certain brightness facilitates resolving brain capillaries with high spatial resolution (≈3 µm) and deep penetration (800 µm). Owning to the deep penetration depth and real‐time imaging capability, in vivo SWIR microscopic angiography exhibits superior resolution in monitoring blood–brain barrier damage in mouse brain, and visualizing enhanced permeability and retention effect in tumor sites. Furthermore, the AIE dots show good biocompatibility, and no noticeable abnormalities, inflammations or lesions are observed in the main organs of the mice. This work will inspire new insights on development of advanced SWIR techniques for biomedical imaging.
Impact of Sr‐Incorporation on Cr Oxidation and Water Dissociation in La(1–x)SrxCrO3
Authors: Stoerzinger Kelsey A. , Du Yingge , Ihm Kyuwook , Zhang Kelvin H. L. , Cai Jun , Diulus J. Trey , Frederick Ryan T. , Herman Gregory S. , Crumlin Ethan J. , Chambers Scott A.
Published: January 2018

The oxidation and reduction of metal oxides and their interaction with the environment play a critical role in material stability and the ability to catalyze reactions. The local change in valence and formation of surface adsorbates affect the oxide electronic structure and chemical reactivity, yet are challenging to probe experimentally. In this paper a detailed study of the oxidation and reduction of Cr in the perovskite oxide family of La(1–x)SrxCrO3 using ambient pressure X‐ray photoelectron spectroscopy is presented. The incorporation of Sr increases the propensity to oxidize at the surface, leading to the presence of Cr4+ and Cr6+ principally confined to the top unit cell when in equilibrium with O2 gas. These acidic sites are readily reduced to Cr3+ in equilibrium with H2O vapor, and the resultant amount of hydroxyls formed from the dissociation of H2O is directly proportional to the density of surface sites formerly oxidized. The quantification of the redox stability of La(1–x)SrxCrO3 and the relationship between the extent of oxidation, reduction, and hydroxylation with Sr yield important insight into the surface functionality during electrochemical applications.
Recovery and Recycling of Chiral Iridium(N,P Ligand) Catalysts from Hydrogenation Reactions
Authors: Müller Marc‐André , Gruber Stefan , Pfaltz Andreas
Published: January 2018

Despite the high efficiency and broad scope of chiral iridium(N,P ligand) complexes as catalysts for asymmetric hydrogenation, the problem of catalyst recovery and recycling has so far attracted little attention. We have found that at the end of a hydrogenation reaction, iridium(N,P ligand) catalysts form dimeric Ir(III) dihydride complexes, which can be converted back to the original precatalysts by addition of COD. Based on these findings, a practically simple protocol for catalyst recovery was devised. The recovered complexes showed essentially the same reactivity and enantioselectivity as the original catalysts. Especially large‐scale applications and hydrogenations of less reactive substrates that require high catalyst loadings will benefit from this protocol that allows recovery and reuse of expensive iridium complexes.

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High Strength Adhesives from Catechol Cross‐Linking of Zein Protein and Plant Phenolics
Authors: Schmidt Gudrun , Hamaker Bruce R. , Wilker Jonathan J.
Published: January 2018

Corn zein is a nontoxic protein that has found use in adhesive and coating materials for pharmaceutical, biomedical, and food applications. The degradability and amphiphilic properties of zein are attractive for materials design. Unmodified zein polymers, however, have drawbacks when it comes to adhesive strength, water resistance, and wet adhesion. Here, compositions of zein plus plant‐based phenolics including catechol, tannic acid, juglone, caffeic acid, quercetin, and gallic acid are examined. Combinations of zein with phenolic components from plants provide high strength adhesive bonding. These catechol‐containing phenolics may present an analogy to the cross‐linking chemistry of catechol found in mussel‐mimetic adhesives. Bonding is tested on dry and wet aluminum substrates using lap shear configurations. In each case, bond strengths are substantial and exceed the minimal bonding of zein only controls. Maximum adhesion for zein + catechol is 8 ± 1 MPa. Under similar conditions, commercial Super Glue bonds at 8 ± 2 MPa. Further results involve examinations of bond persistence on substrates submerged under water. Such results indicate that proper formulation efforts yield strong adhesives with some water resistance. These studies show that benign components from food can provide performance comparable to the petroleum‐based materials in current wide spread use.
Solid‐state foaming of epoxy resin under hypergravity and simulated microgravity
Authors: Quadrini Fabrizio , Tedde Giovanni Matteo , Santo Loredana , van Loon Jack J.W.A.
Published: January 2018

Solid‐state foaming of epoxy resins has been performed under simulated microgravity by the random positioning machine (RPM) and under hypergravity by the large diameter centrifuge (LDC). More than 50 tests have been performed in static and dynamic conditions in different experimental configurations. Longitudinal, radial, and volumetric foaming ratios have been extracted from foaming tests, and correlated with the applied gravity conditions. Results show that the gravity vector has two opposite effects; the first on the flow front movement and the second on the contact between the sample and the oven. The second effect seems to be stronger, and the important role of heat transfer is confirmed. Nevertheless, effects related to apply centrifugal forces have been found and discussed, above all in the case of LDC tests.
Biomimetic Bipolar Microcapsules Derived from Staphylococcus aureus for Enhanced Properties of Lithium–Sulfur Battery Cathodes
Authors: Wu Wenlu , Pu Jun , Wang Jian , Shen Zihan , Tang Haiyan , Deng Zhentao , Tao Xinyong , Pan Feng , Zhang Huigang
Published: January 2018

Lithium–sulfur (Li–S) batteries suffer from some serious issues, such as volume expansion, polysulfide migration, and so on, which lead to inferior rate properties, low Coulombic efficiency, and poor cycling stability. To a great extent, the significantly changing polarities, conductivities, and solubilities of sulfur species complicate these issues and make them hard to deal with. In this study, a biomimetic bipolar microcapsule is developed via bacteria fermentation and chemical modification. The biomimetic hierarchical microcapsule has a nonpolar core to load active materials and a polar shell to “selectively” control mass transport in and out. Each capsule acts as a microreactor, which adsorbs sulfur with the porous carbon core, retards polysulfide migration with the polar TiO2 shell, and only facilitates lithium ion diffusion through the shell. The advantages of bipolar microcapsules are able to concurrently address S hosting, electron conducting, and polysulfide migration issues in particle scales instead of electrode scales. Because the resulting sulfur cathodes effectively interact with all sulfur species and confine them inside microcapsules, those intractable issues that lead to poor cycling properties are significantly managed. Thus, a high specific capacity and excellent cycling stability are achieved by using this novel structure design.
Stochastic back‐off algorithm for simultaneous design, control, and scheduling of multiproduct systems under uncertainty
Authors: Koller Robert W. , Ricardez‐Sandoval Luis A. , Biegler Lorenz T.
Published: January 2018

An algorithm that employs the back‐off method to provide optimal solutions for integration of design, control, and scheduling for multiproduct systems is presented, featuring a flexibility and feasibility analysis. The algorithm employs Monte Carlo (MC) sampling to generate a large number of random realizations, and simulate the system to determine feasibility. Back‐off terms are determined and incorporated into a new flexibility analysis to approximate the effect of stochastic uncertainty and disturbances. Through successive iterations, the algorithm converges, terminating on a solution that is robust to a specified level of process variability due to stochastic realizations in the disturbances and uncertain parameters. The proposed algorithm has been successfully applied to a multiproduct continuous stirred tank reactor for which optimal design, control, and scheduling decisions are identified, subject to stochastic uncertainty and disturbance. The present approach has been compared to a critical‐set (multiscenario) method showing the benefits and limitations of both approaches. © 2018 American Institute of Chemical EngineersAIChE J, 64: 2379–2389, 2018
Highly efficient methane reforming over a low‐loading Ru/γ‐Al2O3 catalyst in a Pd‐Ag membrane reactor
Authors: Simakov David S. A. , Román‐Leshkov Yuriy
Published: January 2018

Natural gas can be reformed to syngas (CH4 + H2O = CO + 3H2), at temperatures above 850°C. Membrane catalytic reformers can provide high CH4 conversions at temperatures below 650°C, by separating H2 from the reactive mixture. Traditional Ni‐based catalysts suffer from low activity at low temperatures and deactivate rapidly by coking, particularly at low steam/carbon ratios. In this study, an ultralow loading (0.15 wt %) Ru/γ‐Al2O3 catalyst was implemented in a lab‐scale membrane reformer, using a supported 5μm Pd‐Ag film membrane. Methane conversions above 90% were achieved at 650°C, 8 bar, and H2O/CH4 = 2, 3 with contact times of ca. 10 s. The system generated up to 3.5 mol of ultrapure H2 per mol of CH4 fed, with a maximum power density of 0.9 kW/L. No significant deactivation was observed after 200 h time on stream, even when using low H2O:CH4 ratios. © 2018 American Institute of Chemical Engineers AIChE J, 64: 3101–3108, 2018
Halogenbrücken in Lösung: Anionenerkennung, Templat‐gestützte Selbstorganisation und Organokatalyse
Authors: Tepper Ronny , Schubert Ulrich S.
Published: January 2018

Die Halogenbrücke beruht auf einer attraktiven Wechselwirkung zwischen einem elektrophilen, kovalent gebundenen Halogensubstituenten und einer Lewis‐Base. Der Schwerpunkt dieser supramolekularen Wechselwirkung lag zwar bisher weitestgehend auf ihrer theoretischen sowie kristallographischen Untersuchung, aber auch ihre Verwendung in Lösung weckte speziell in den letzten Jahren sehr großes Interesse. Dieser Kurzaufsatz beleuchtet ausgewählte Neuerungen auf diesem hoch aktuellen Gebiet und fokussiert sich dabei auf den Einsatz von Halogenbrücken‐basierten Rezeptoren zur Anionenerkennung, templatgestützten Selbstorganisation und Organokatalyse in Lösung.
Solvent‐Free Enzyme Activity: Quick, High‐Yielding Mechanoenzymatic Hydrolysis of Cellulose into Glucose
Authors: Hammerer Fabien , Loots Leigh , Do Jean‐Louis , Therien J. P. Daniel , Nickels Christopher W. , Friščić Tomislav , Auclair Karine
Published: January 2018

Mechanochemistry enables enzymatic cleavage of cellulose into glucose without bulk solvents, acids, other aggressive reagents, or substrate pre‐treatment. This clean mechanoenzymatic process (coined RAging) is also directly applicable to biomass, avoids many limitations associated with the use of cellulases, and produces glucose concentrations greater than three times that obtained by conventional methods.
Isotope Substitution of Promiscuous Alcohol Dehydrogenase Reveals the Origin of Substrate Preference in the Transition State
Authors: Behiry Enas M. , Ruiz‐Pernia J. Javier , Luk Louis , Tuñón Iñaki , Moliner Vicent , Allemann Rudolf K.
Published: January 2018

The origin of substrate preference in promiscuous enzymes was investigated by enzyme isotope labelling of the alcohol dehydrogenase from Geobacillus stearothermophilus (BsADH). At physiological temperature, protein dynamic coupling to the reaction coordinate was insignificant. However, the extent of dynamic coupling was highly substrate‐dependent at lower temperatures. For benzyl alcohol, an enzyme isotope effect larger than unity was observed, whereas the enzyme isotope effect was close to unity for isopropanol. Frequency motion analysis on the transition states revealed that residues surrounding the active site undergo substantial displacement during catalysis for sterically bulky alcohols. BsADH prefers smaller substrates, which cause less protein friction along the reaction coordinate and reduced frequencies of dynamic recrossing. This hypothesis allows a prediction of the trend of enzyme isotope effects for a wide variety of substrates.
Preparation and Characterization of Ni‐Modified Graphene Oxide Complex as an Efficient Catalyst for the Synthesis of Sulfides via Reaction of Arylhalides with S8 or Thiourea
Authors: Ghafouri‐Nejad Raziyeh , Hajjami Maryam , Nejat Razieh
Published: January 2018

In this work, complex of Ni‐modified graphene oxide was prepared and characterized using FT‐IR spectroscopy, SEM, XRD, TGA and ICP‐OES techniques. This compound used as an efficient and recoverable catalyst for the C–S coupling reaction using sulfur‐transfer reagents (S8 or thiourea). The catalyst was easily separated using a simple filtration and reusable without significant loss of their catalytic efficiency.
Novel Pyrazoline‐based Organometallic Compounds Containing Ferrocenyl and Quinoline units: Synthesis, Characterization and Microbial susceptibilities
Authors: Parveen Humaira , Alatawi Raedah Aiyed Suliman , Alsharif Meshari A. , Alahmdi Mohammed Issa , Mukhtar Sayeed , Khan Salman Ahmad , Hasan Sadaf , Khan Asad U.
Published: January 2018

Some novel pyrazoline‐based organometallic compounds were synthesized as new leads in antimicrobial chemotherapy. The structures of compounds were elucidated by different spectroscopic techniques and elemental analyses. All compounds were investigated for in vitro antimicrobial studies against fifteen ATTC bacterial and fungal strains. The microbial susceptibility of these compounds revealed that all the tested compounds gave good minimum inhibitory concentration (MIC) values against the tested organisms that are either similar or even better than the reference drugs amoxicillin and fluconazole, which gave MIC values 8‐64 μg/ml against bacterial and 64 μg/ml against fungal strains, respectively. Among all compounds, compound (4d)

1‐(5‐(4‐chlorophenyl)‐3‐ferrocenyl‐4,5‐dihydropyrazol‐1‐yl)‐2‐quinolin‐8‐yloxy) ethanone, emerged out the most promising antimicrobial organometallic derivative with MIC values against all the strains ranging from 8‐32 μg/ml. Other compounds gave a range of MIC values between 16‐64 μg/ml against S. bovis, 16‐32 μg/ml against E. coli, and C. tropicalis except compound (4d) which gave MIC 8 μg/ml against S. bovis and E. coli, whereas 32 μg/ml against C. tropicalis. Collectively, these compounds gave a lower MIC value between 32‐64 μg/ml against both of the biofilm forming strains namely, P. aeruginosa and S. mutans. The results of microbial susceptibility concluded that these novel organometallic compounds are new leads in antimicrobial chemotherapy and can be very useful for further optimization work on microbial chemotherapy.
Soil polymer conditioner based on montmorillonite‐poly(acrylic acid) composites
Authors: Lerma Tulio A. , Palencia Manuel , Combatt Enrique M.
Published: January 2018

The constant deterioration of the soil as a result of natural and anthropogenic processes produces decrease of soil fertility and agricultural production, increase in the cost of food, desertification, and loss of water resources. The objective of this work was to develop a hybrid composite that structural and functionally mimics the humified structure of soils for the development of remediation strategies based on geotransformation of degraded soils. For that, two different strategies for the modification of clay surface were evaluated: (i) covalent linking using trichlorovinylsilane and (ii) electrostatic interaction using N‐vinylbenzyl‐N‐triethyl ammonium chloride. Later, modified clay was characterized and used as crosslinking agent during the free‐radical polymerization of acrylic acid. Particulate nanostructured polymers were characterized and their water absorption capacity, cationic exchange capacity, and ionic retention capacity were determined. Results showed that clay‐poly(acrylic acid) composites can be obtained by described methodology. In addition, materials with 60 and 80% w/w of modified MMT were obtained with particulate shape, high water absorption capacity (273%–568%), high cationic exchange capacity (124–666 meq+/100 g) and high ionic retention capacity (108–194 and 263–313 meq/100 g for major and minor elements, respectively). Finally, it was concluded that synthesized materials mimic structural and functionally the humified structure of soils. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46211.
Secretory expression of negative regulatory region of human Notch1 in Escherichia coli and preparation of a functional polyclonal antibody
Authors: Zhang Dengyang , Sun Tianzhu , Yan Jingyun , Wang Xuanjun , Sheng Jun
Published: January 2018

Notch signaling is a highly conserved pathway existed in multicellular organisms. It plays roles in normal human body development, human cancer initiation, progression and metastasis. The Notch negative regulatory region (NRR) is critical for Notch signaling, and cleavage at the S2 site in the NRR ultimately leads to the activation of Notch signaling. To study the function of human NRR1, we expressed the recombinant human NRR1 (rhNRR1) domain in Escherichia coli. After purification, rhNRR1 was obtained with approximately 94% purity according to SDS‐PAGE analysis. Furthermore, the polyclonal anti‐rhNRR1 serum raised by immunizing mouse with the purified rhNRR1 was able to reduce the generation of active form of Notch1 intracellular domain in HeLa cells, which implied the raised antibody could recognize and bind the natural conformation of Notch1 NRR. Preparation of rhNRR1 by this way is convenient, time‐consuming, and could be used to the preparation of anti‐NRR1 therapeutic antibody.
Gene–gene interaction between MSX1 and TP63 in Asian case‐parent trios with nonsyndromic cleft lip with or without cleft palate
Authors: Liu Dongjing , Schwender Holger , Wang Mengying , Wang Hong , Wang Ping , Zhu Hongping , Zhou Zhibo , Li Jing , Wu Tao , Beaty Terri H.
Published: January 2018

Background

Small ubiquitin‐like modification, also known as sumoylation, is a crucial post‐translational regulatory mechanisms involved in development of the lip and palate. Recent studies reported two sumoylation target genes, MSX1 and TP63, to have achieved genome‐wide level significance in tests of association with nonsyndromic clefts. Here, we performed a candidate gene analysis considering gene–gene and gene–environment interaction for SUMO1, MSX1, and TP63 to further explore the etiology of nonsyndromic cleft lip with or without cleft palate (NSCL/P).

Methods

A total of 130 single‐nucleotide polymorphisms (SNPs) in or near SUMO1, MSX1, and TP63 was analyzed among 1,038 Asian NSCL/P trios ascertained through an international consortium. Conditional logistic regression models were used to explore gene–gene (G × G) and gene–environment (G × E) interaction involving maternal environmental tobacco smoke and multivitamin supplementation. Bonferroni correction was used for G × E analysis and permutation tests were used for G × G analysis.

Results

While transmission disequilibrium tests and gene–environment interaction analysis showed no significant results, we did find signals of gene–gene interaction between SNPs near MSX1 and TP63. Three pairwise interactions yielded significant p values in permutation tests (rs884690 and rs9290890 with p = 9.34 × 10−5 and empirical p = 1.00 × 10−4, rs1022136 and rs4687098 with p = 2.41 × 10−4 and empirical p = 2.95 × 10−4, rs6819546 and rs9681004 with p = 5.15 × 10−4 and empirical p = 3.02 × 10−4).

Conclusion

Gene–gene interaction between MSX1 and TP63 may influence the risk of NSCL/P in Asian populations. Our study provided additional understanding of the genetic etiology of NSCL/P and underlined the importance of considering gene–gene interaction in the etiology of this common craniofacial malformation.
Does the reason matter? How student‐reported reasons for school absence contribute to differences in achievement outcomes among 14–15 year olds
Authors: Hancock Kirsten J. , Gottfried Michael A. , Zubrick Stephen R.
Published: January 2018

While an emerging body of research has examined the effects of school absences on student outcomes, there is comparatively little research examining the different reasons contributing to school absence, how common these reasons are, and the extent to which different types of absences are differentially associated with achievement. To address these gaps, we used data from the Longitudinal Study of Australian Children to examine the reasons for school absence as reported by 14–15 year olds and how these reasons relate to achievement outcomes in Year 9. Only 7% of 14–15 year olds indicated they had been absent in the previous six months without parental consent, of which 46% indicated the most recent absence was due to problems at school. Of the 90% of students who had been absent with parental consent, only 6% said the most recent absence was due to problems at school. After controlling for student, family and school characteristics and Year 7 achievement, Year 9 achievement was most strongly associated with absences related to student‐ or family‐level reasons. While schools typically bear the responsibility for monitoring and responding to absenteeism, the drivers of absence may not be related to factors that schools can realistically address. For schools, addressing absenteeism requires a dual approach of preventing avoidable absences and mitigation strategies for when either avoidable or unavoidable absences occur.