bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ion‐Specific Assembly of Strong, Tough, and Stiff Biofibers
Authors: Mittal Nitesh , Benselfelt Tobias , Ansari Farhan , Gordeyeva Korneliya , Roth Stephan V. , Wågberg Lars , Söderberg L. Daniel 
Published: October 2019

AbstractDesigning engineering materials with high stiffness and high toughness is challenging as stiff materials tend to be brittle. Many biological materials realize this objective through multiscale (i.e., atomic‐ to macroscale) mechanisms that are extremely difficult to replicate in synthetic materials. Inspired from the architecture of such biological structures, we here present flow‐assisted organization and assembly of renewable native cellulose nanofibrils (CNFs), which yields highly anisotropic biofibers characterized by a unique combination of high strength (1010 MPa), high toughness (62 MJ m−3) and high stiffness (57 GPa). We observed that properties of the fibers are primarily governed by specific ion characteristics such as hydration enthalpy and polarizability. A fundamental facet of this study is thus to elucidate the role of specific anion binding following the Hofmeister series on the mechanical properties of wet fibrillar networks, and link this to the differences in properties of dry nanostructured fibers. This knowledge is useful for rational design of nanomaterials and is critical for validation of specific ion effect theories. The bioinspired assembly demonstrated here is relevant example for designing high‐performance materials with absolute structural control.
Pyridiniumsalze als redoxaktive Reagenzien zur Übertragung funktioneller Gruppen
Authors: Rössler Simon L. , Jelier Benson J. , Magnier Emmanuel , Dagousset Guillaume , Carreira Erick M. , Togni Antonio 
Published: October 2019

AbstractIn diesem Aufsatz sind die jüngsten Fortschritte beim Verständnis und Design von N‐funktionalisierten Pyridiniumsalzen als redoxaktivierte Einelektronentransfer‐Reagenzien zur Übertragung funktioneller Gruppen zusammengefasst. Anhand einer Auswahl an repräsentativen Methoden werden Reaktivität und grundlegende Fortschritte in diesem sich rasch entwickelnden Bereich diskutiert. Diese Reagenzien weisen zwei grundsätzlich divergierende Reaktionspfade auf: homolytische Fragmentierung zur Freisetzung des N‐gebundenen Substituenten als entsprechendes Radikal oder eine alternative, heterolytische Fragmentierung zur Freisetzung eines radikalischen Pyridiniumkations. Die elementaren Schritte der durch Einelektronentransfer induzierten Fragmentierung werden kritisch diskutiert.
A Triazole‐Substituted Aryl Iodide with Omnipotent Reactivity in Enantioselective Oxidations
Authors: Abazid Ayham H. , Nachtsheim Boris J. 
Published: October 2019

AbstractA widely applicable triazole‐substituted chiral aryl iodide is described as catalyst for enantioselective oxidation reactions. The introduction of a substituent in ortho‐position to the iodide is key for its high reactivity and selectivity. Besides a robust and modular synthesis, the main advantage of this catalyst is the excellent performance in a plethora of mechanistically diverse enantioselective transformations, such as spirocyclizations, phenol dearomatizations, α‐oxygenations, and oxidative rearrangements. DFT‐calculations of in situ generated [hydroxy(tosyloxy)iodo]arene isomers give an initial rational for the observed reactivity.
Effect of pH on the physicochemical properties of starch films
Authors: Sakkara Seema , Nataraj Divya , Venkatesh Krishna , Xu Yixiang , Patil Jagadish H. , Reddy Narendra 
Published: October 2019

ABSTRACTWe demonstrate a simple approach of using highly alkaline starch solutions to obtain films with high flexibility and improved water resistance. Extensive studies have been done to develop films from starch, primarily for food applications. However, films developed from starch are brittle and generally chemical modifications or plasticizers are used to improve the flexibility and other properties of starch films. Such modifications make starch expensive, decrease biodegradability, and affect the morphology and subsequent processing of starch. In this research, we have prepared films using starch solutions at pH between 3 and 11. Starch solutions having different pHs were made into films and the tensile, thermal properties, and resistance to water were studied. It was found that preparing starch with pH 11 solution imparts high flexibility without any apparent physical damage. Films prepared under strong acidic and alkaline conditions also had considerably reduced hydrophilicity, which is required for food packaging and other applications. The films prepared at alkaline pH show nearly 50% reduction in water sorption and an increase in elongation. The films obtained from alkaline pH are flexible and water resistant and can potentially be used to develop various bioproducts. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48563.
Fabrication of althea officinalis loaded electrospun nanofibrous scaffold for potential application of skin tissue engineering
Authors: Ghaseminezhad Keyhan , Zare Mohadeseh , Lashkarara Saba , Yousefzadeh Maryam , Aghazadeh Mohandesi Jamshid 
Published: October 2019

ABSTRACTThe Althea Officinalis (AO) extract is well known as a traditional herbal drug for its wound healing ability owing to the anti‐inflammatory and antimicrobial properties. Furthermore, its mucilaginous properties provide moisturizing and nutritional effects on skin cell proliferation. Therefore, AO extract can be applied in the temporary skin substitute for the ability to expedite the therapy duration. In this study, different concentrations of AO extract (0, 5, 10, 15, and 20 wt %) were incorporated into the nanofibrous scaffolds to study their potential for the skin tissue repairing. The desired scaffolds were prepared by electrospinning the blend of poly(ε‐caprolactone) and gelatin as a synthesized and natural polymer. The electrospun nanofibers were characterized by SEM, FTIR, DSC, TGA, tensile, AO extract release, and cellular culture tests. This study proposed incorporating the AO extract into the nanofibrous scaffolds for accelerating the skin tissue repairing and the optimized amount of AO extract as about 15% was introduced for offering the most desirable electrospun scaffolds for this application. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48587.
Effects of compatibilizer on the mechanical, rheological, and shape memory behaviors of poly(lactic acid) and poly(MnBM) blends
Authors: Kim Sung Kyu , Jang Robin , Kim Woo Nyon 
Published: October 2019

ABSTRACTThe effects of compatibilizer on the morphological, mechanical, rheological, and shape memory properties of poly(lactic acid) (PLA) and poly(methyl methacrylate‐block‐n‐butyl acrylate‐block‐methyl methacrylate) (Poly(MnBM)) (80/20) blend were investigated. From the morphological results, the addition of 1 wt% SAN‐MAH as a compatibilizer showed minimum Poly(MnBM) domain size among the blends with the SAN‐MAH in the amounts from 0 to 7 wt%. Tensile and flexural strengths, and complex viscosity of the blends showed maximum when the SAN‐MAH content was 1 wt%, which suggested the increased compatibility between the PLA and Poly(MnBM) phases. From the above results, the optimum compatibilizer content of the PLA and Poly(MnBM) blend was 1 wt%. The recovery ratio of tensile energy was found to be 83 and 56% for the PLA/Poly(MnBM) blend with and without the SAN‐MAH (1 wt%), respectively. Upon blending the PLA and Poly(MnBM) (80/20) with SAN‐MAH (1 wt%), the increase of recovered tensile energy was observed, and that the brittleness of PLA was improved to be ductile which resulted an improved shape memory behavior of the blend. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2020,137, 48591.
Sitagliptin protects liver against aflatoxin B1‐induced hepatotoxicity through upregulating Nrf2/ARE/HO‐1 pathway
Authors: Ji Yujiang , Nyamagoud Sanatkumar B. , SreeHarsha Nagaraja , Mishra Anurag , Gubbiyappa Shiva K. , Singh Yogendra 
Published: October 2019

ABSTRACTDipeptidyl peptidase‐4 inhibitor (DPP‐4 inhibitor) such as sitagliptin has been presented as antidiabetic drugs and has numerous restorative advantages over different diseases; however, its defensive role against aflatoxin b1 (AFB1) liver toxicity has not been previously examined. Wistar rats (65 weeks, male) were utilized in the investigation. Animals were divided into five different groups (n = 10): control; AFB1; AFB1 + Sita (50); AFB1 + Sita (100); and Sita (100). Sitagliptin significantly (*p ≤ .05, **p ≤ .01, and ***p ≤ .001) altered the levels of various serum liver enzymes (lactate dehydrogenase, alkaline phosphate, aspartate aminotransferase, and alanine aminotransferase). It decreased the concentration of an oxidative stress marker, that is, malondialdehyde and increased the level of antioxidant enzymes such as reduced glutathione, catalase, superoxide dismutase, and glutathione peroxidase in AFB1‐administered rats. It also improved the Nrf2 expression and HO‐1 level in AFB1‐intoxicated rats. This investigation discusses innovative evidence on the protective role of sitagliptin against AFB1‐induced hepatotoxicity in rats.
Intestine‐on‐chip device increases ECM remodeling inducing faster epithelial cell differentiation
Authors: De Gregorio Vincenza , Corrado Brunella , Sbrescia Simone , Sibilio Sara , Urciuolo Francesco , Netti Paolo A. , Imparato Giorgia 
Published: October 2019

AbstractAn intestine‐on‐chip has been developed to study intestinal physiology and pathophysiology as well as intestinal transport absorption and toxicity studies in a controlled and human similar environment. Here, we report that dynamic culture of an intestine‐on‐chip enhances extracellular matrix (ECM) remodeling of the stroma, basement membrane production and speeds up epithelial differentiation. We developed a three‐dimensional human intestinal stromal equivalent composed of human intestinal subepithelial myofibroblasts embedded in their own ECM. Then, we cultured human colon carcinoma‐derived cells in both static and dynamic conditions in the opportunely designed microfluidic system until the formation of a well‐oriented epithelium. This low cost and handy microfluidic device allows to qualitatively and quantitatively detect epithelial polarization and mucus production as well as monitor barrier function and ECM remodeling after nutraceutical treatment.
A Platelet Graphitic Nanofiber‐Carbon Nanotube Hybrid for Efficient Oxygen Evolution Reaction
Authors: Ali Zulfiqar , Mehmood Mazhar , Ahmad Jamil , Li Xin , Majeed Abdul , Tabassum Hassina , Hou Peng‐Xiang , Liu Chang 
Published: October 2019

AbstractCarbon nanostructures with a high‐density of active sites are needed as catalysts for the oxygen evolution reaction (OER). Here we report a platelet graphitic nanofiber‐carbon nanotube (PGNF‐CNT) hybrid electrocatalyst prepared by chemical vapor deposition. The material is composed of interconnected CNTs and nanofibers consisting of graphitized carbon layers stacked at different angles to the fiber axis with a large number of exposed edges. These unique structural characteristics give the hybrid a high density of active sites, fast electron transfer and a large number of mass transport paths. As a result, the material has an excellent electrocatalytic activity for OER with an overpotential of 0.28 V at a current density of 10 mA cm−2, which is much better than those of Ir/C and previously‐reported carbonaceous catalysts.
Electrochemical and Chemical Instability of Vanadium Nitride in the Synthesis of Ammonia Directly from Nitrogen
Authors: Manjunatha Revanasiddappa , Karajić Aleksandar , Teller Hanan , Nicoara Katherina , Schechter Alex 
Published: October 2019

AbstractRecently, vanadium nitride (VN) was proposed as an active catalyst for a challenging electrochemical nitrogen reduction reaction (NRR) to ammonia. In this study, the stability of vanadium‐nitride in electrolyte solutions of different pH values was studied under selected cathodic potentials. Intensive leaching of vanadium ions and nitrogen constituents into the bulk of the electrolyte solution was confirmed from ICP‐OES and UV‐Vis results.
Ni(OH)2 Nanosheet Electrocatalyst toward Alkaline Urea Electrolysis for Energy‐Saving Acidic Hydrogen Production
Authors: Chen Jingting , Ci Suqin , Wang Genxiang , Senthilkumar Nangan , Zhang Mengtian , Xu Qiuhua , Wen Zhenhai 
Published: October 2019

AbstractIt is highly attractive to develop efficient water electrolysis route to implement hydrogen generation in a low‐cost way, which while requires excess energy to surmount the activation barriers majorly limited by oxygen evolution reaction at anode side. Herein, we report an acid‐alkali asymmetric‐electrolyte electrolyzer (AAAE) that can achieve substantial energy saving for electrolysis hydrogen generation, thanks to the assistance of electrochemical neutralization energy (ENE) and urea oxidation reaction (UOR). To this end, free‐standing Ni(OH)2 nanosheets on carbon cloth (Ni(OH)2−NSs/CC) is fabricated as catalytic anode for alkaline UOR, which manifests impressively high catalytic activity with delivering 10 mA cm−2 at 1.32 V and long‐term durability. The as‐developed AAAE only requires an applied voltage of 0.66 V to release the electrolysis current of 10 mA cm−2, yielding the H2 Faraday efficiency close to 100 % along with H2 production rate of 183.8 μmol h−1.
Synergism of Interface and Electronic Effects: Bifunctional N‐Doped Ni3S2/N‐Doped MoS2 Hetero‐Nanowires for Efficient Electrocatalytic Overall Water Splitting
Authors: Xu You , Chai Xingjie , Ren Tianlun , Yu Hongjie , Yin Shuli , Wang Ziqiang , Li Xiaonian , Wang Liang , Wang Hongjing 
Published: October 2019

AbstractThe realization of water electrolysis on the basis of highly active, cost‐effective electrocatalysts is significant yet challenging for achieving sustainable hydrogen production from water. Herein, N‐doped Ni3S2/N‐doped MoS2 1D hetero‐nanowires supported by Ni foam (N‐Ni3S2/N‐MoS2/NF) are readily synthesized through a chemical transformation strategy by using NiMoO4 nanowire array growth on Ni foam (NiMoO4/NF) as the starting material. With the in situ generation of Ni3S2/MoS2 heterointerfaces within nanowires and the incorporation of N− anions, an extraordinary hydrophilic nature with abundant, well‐exposed active sites and optimal reaction dynamics for both oxidation and reduction of water are obtained. Attributed to these properties, as‐converted N‐Ni3S2/N‐MoS2/NF exhibits highly efficient electrocatalytic activities for both hydrogen and oxygen evolution reactions under alkaline conditions. The superior bifunctional properties of N‐Ni3S2/N‐MoS2/NF enable it to effectively catalyze the overall water‐splitting reaction.
Multi‐C−C/C−N‐Coupled Light‐Emitting Aliphatic Terpolymers: N−H‐Functionalized Fluorophore Monomers and High‐Performance Applications
Authors: Mahapatra Manas , Dutta Arnab , Roy Joy Sankar Deb , Das Ujjal , Banerjee Snehasis , Dey Sanjit , Chattopadhyay Pijush Kanti , Maiti Dilip K. , Singha Nayan Ranjan 
Published: October 2019

AbstractTo circumvent costly fluorescent labeling, five nonconventional, multifunctional, intrinsically fluorescent aliphatic terpolymers (1–5) have been synthesized by C−C/C−N‐coupled, solution polymerization of two non‐emissive monomers with protrusions of fluorophore monomers generated in situ. These scalable terpolymers were suitable for sensing and high‐performance exclusion of CuII, logic function, and bioimaging. The structures of the terpolymers, in situ attachment of fluorescent monomers, aggregation‐induced enhanced emission, bioimaging ability, and super adsorption were investigated by 1H and 13C NMR, EPR, FTIR, X‐ray photoelectron, UV/Vis, and atomic absorption spectroscopy, thermogravimetric analysis, high‐resolution transmission electron microscopy, dynamic light scattering, solid‐state fluorescence, fluorescence imaging, and fluorescence lifetime measurements, as well as by isotherm, kinetics, and thermodynamic studies. The geometries and electronic structures of the fluorophores and the absorption and emission properties of the terpolymers were examined by DFT, time‐dependent DFT, and natural transition orbital analyses. For 1, 2, and 5, the limits of detection were determined to be 1.03×10−7, 1.65×10−7, and 1.77×10−7 m, respectively, and the maximum adsorption capacities are 1575.21, 1433.70, and 1472.21 mg g−1, respectively.
Halogen versus Hydrogen Bonding in Binary Cocrystals: Novel Conformation a Coformer with [2+2] Photoreactivity of Criss‐Crossed C=C Bonds
Authors: Quentin Jay , MacGillivray Leonard R. 
Published: October 2019

AbstractA series of cocrystals involving the hydrogen‐ and halogen‐bond donor coformers catechol (cat) and 1,2‐diiodotetrafluorobenzene (1,2‐di‐I‐tFb), respectively, is reported. Each coformer forms a cocrystal with each of the three symmetric bipyridines trans‐1,2‐bis(n‐pyridyl)ethylene (n,n′‐bpe, where: n=n′=2, 3, 4). Four novel cocrystals (cat) ⋅ (3,3′‐bpe), 2(1,2‐di‐I‐tFb) ⋅ (2,2′‐bpe), 2(1,2‐di‐I‐tFb) ⋅ (3,3′‐bpe), and (1,2‐di‐I‐tFb) ⋅ (4,4′‐bpe) comprise components that assemble by either O−H⋅⋅⋅N hydrogen bonds (cat) or N⋅⋅⋅I halogen bonds (1,2‐di‐I‐tFb). In (cat) ⋅ (3,3′‐bpe), cat acts as a template to support an intermolecular [2+2] photocycloaddition of 3,3′‐bpe. The reactivity occurs via a one‐dimensional (1D) hydrogen‐bonded tape with stacked and criss‐crossed olefins that react stereoselectively and quantitatively to form rctt‐tetrakis(3‐pyridyl)cyclobutane (3,3′‐tpcb). The reactivity of the criss‐crossed olefins is facilitated by a hitherto not reported cis‐gauche conformation adopted by cat. The stereochemistry of 3,3′‐tpcb is confirmed in the cocrystal 2(cat) ⋅ (3,3′‐tpcb).
Short‐term geomorphological and riparian vegetation responses to a 40‐year flood on a braided, dryland river
Authors: González Eduardo , Shafroth Patrick B. , Lee Steven R. , Leverich Glen T. , Real De Asua Rafael , Sherry Rebecca A. , Ostoja Steven M. , Orr Bruce K. 
Published: October 2019

AbstractIn December 2010, a 40‐year flood occurred in the lower Virgin River (SE Nevada, southwestern United States), a braided river segment with riparian vegetation largely dominated by invasive shrubs in the genus Tamarix. We assessed geomorphological and vegetation responses to this large magnitude disturbance event by comparing pre‐ and post‐flood remote sensing and field survey data in four river reaches. Analyses of orthophotos and light detection and ranging‐derived topography showed that both the active channel area and channel width increased between 80% and 258%, representing an increase from 13% to 30% of the total river corridor area. Erosion predominated in the outer bends of the enlarged channel and deposition in the pre‐flood channel, causing local avulsions of the low‐flow channel. Field‐based topographic data recorded before and after the flood in 385 plots also showed that deposition occurred in parts of the floodplain that were not eroded. Two thirds of woody vegetation cover (mainly dominated by Tamarix, with some native shrub Pluchea sericea) was lost in areas that eroded (~20% of the river corridor). In the remaining ~80% of stable river corridor (aggrading or no change in elevation) Tamarix remained dominant. Following erosion, but also where sediment deposition predominated under the Tamarix canopy, the most common colonizing vegetation in the understory was comprised of annual plants, especially Salsola tragus. Our study supported previous studies describing large floods in braided rivers; we documented the first phase of a cycle of channel widening and increase in vegetation heterogeneity that is commonly followed by narrowing and vegetation homogenization.
Macroclimate and local hydrological regime as drivers of fen vegetation patterns in Tierra del Fuego (Argentina)
Authors: Pérez‐Haase Aaron , Iturraspe Rodolfo , Ninot Josep M. 
Published: October 2019

AbstractIn southern South America, a sharp macroclimatic gradient is found, triggered by the Pacific oceanic influence through the Andes. Mires are substantial landscape units along the gradient, where they play varying roles through the area and include varying plant communities. In this study, we analysed the relationship between vegetation and main abiotic factors in the minerotrophic mires (fens) at two different scales.We chose three fens in Isla Grande from Cordillera and Magellanic Steppe zones and their ecotone. There we characterized the distinct habitats by means of monitoring the water table fluctuations, the peat and the groundwater chemistry, and the vascular plant species composition.The main floristic patterns were revealed by means of classification and ordination of 75 vegetation plots. Thus, we classified the relevés through multivariate analyses into six plant community types, two of which found in each fen. Behind the floristic distinctiveness of each site and each community type, structural vegetation descriptors such as species richness were similar. Overall, water table variables and groundwater chemistry showed the most important environmental differences between fens.Our data point that the main environmental force driving vegetation patterns was the macroclimatic gradient, which shapes the regional floristic pools. This gradient would be also responsible for modifying the local conditions of the fen habitats, mostly in the form of broadening the hydrological conditions within the fens of the Steppe. At each fen, the hydrological regime is the main factor in the distribution of vascular plants, particularly through the varying water table depths.
Comparative Assessment of the Sensitivity of Fish Early-Life Stage, Daphnia, and Algae Tests to the Chronic Ecotoxicity of Xenobiotics: Perspectives for Alternatives to Animal Testing
Authors: Teixidó Elisabet , Leuthold David , de Crozé Noémie , Léonard Marc , Scholz Stefan 
Published: October 2019

Abstract
No-observed-effect concentrations (NOECs) are used in environmental hazard classification and labeling of chemicals and their environmental risk assessment. They are typically obtained using standard tests such as the fish early-life stage (FELS) toxicity test, the chronic Daphnia reproduction test, and the algae growth inhibition test. Given the demand to replace and reduce animal tests, we explored the impact of the FELS toxicity test on the determination of effect concentrations by comparing the FELS toxicity test and the Daphnia and algae acute or chronic toxicity tests. Lowest-observed-effect concentrations (LOECs) were used instead of NOECs for better comparison with median lethal or effect concentration data. A database of FELS toxicity data for 223 compounds was established. Corresponding Daphnia and algae toxicity tests were identified using established databases (US Environmental Protection Agency ECOTOX, Organisation for Economic Co-operation and Development QSAR Toolbox, eChemPortal, EnviroTox, and OpenFoodTox). Approximately 9.5% of the investigated compounds showed a 10-fold higher sensitivity with the FELS toxicity test in comparison with the lowest effect concentrations obtained with any of the other tests. Some of these compounds have been known or considered as endocrine disrupting, or are other non-narcotic chemicals, indicating that the higher sensitivity in the FELS toxicity test is related to a specific mechanism of action. Targeting these mechanisms by alternative test systems or endpoints, using fish embryos for instance, may allow reduction or replacement of the FELS toxicity test or may allow us to prioritize compounds for conduction of the FELS toxicity test. Environ Toxicol Chem 2019;39:30–41. © 2019 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.