bluuebunny/crossref_metadata_2025_split huggingface dataset:
Glycerol Isopropyl Ethers: Direct Synthesis from Alcohols and Synthesis by the Reduction of Solketal
Authors: Samoilov Vadim O. , Onishchenko Maria O. , Ramazanov Dzhamalutdin N. , Maximov Anton L. 
Published: March 2017

AbstractThe catalytic reduction of solketal ((2,2‐dimethyl‐1,3‐dioxolan‐4‐yl)methanol) over bifunctional heterogeneous palladium catalysts is proposed as an alternative to the synthesis of glycerol isopropyl ethers by the etherification of glycerol. The direct synthesis of glycerol isopropyl ethers from isopropanol and glycerol requires severe conditions (T=130–150 °C, p(H2)=20–35 bar) and a large excess of isopropanol to reach a considerable yield. The main reaction products in the catalytic reduction of solketal are glycerol mono‐ and di‐isopropyl ethers and solketal isopropyl ether. Solketal conversion over Al‐HMS‐supported palladium catalysts (T=120 °C and p(H2)=20 bar) affords a mixture of ethers with a high degree of conversion (87 %), 78 % selectivity, and excellent regioselectivity between isomeric ethers. Zeolite‐BEA‐supported palladium catalysts also exhibit high activity but much lower selectivity because of intense acetone aldol condensation. The effects of Si/Al ratios in BEA zeolites and Al‐HMS aluminosilicates and the amounts of supported palladium (1 and 2 wt %) on the properties of the catalysts at different reaction temperatures and hydrogen pressures are considered.
All‐Weather Solar Cells: A Rising Photovoltaic Revolution
Authors: Tang Qunwei 
Published: March 2017

AbstractSolar cells have been considered as one of the foremost solutions to energy and environmental problems because of clean, high efficiency, cost‐effective, and inexhaustible features. The historical development and state‐of‐the‐art solar cells mainly focus on elevating photoelectric conversion efficiency upon direct sunlight illumination. It is still a challenging problem to realize persistent high‐efficiency power generation in rainy, foggy, haze, and dark‐light conditions (night). The physical proof‐of‐concept for all‐weather solar cells opens a door for an upcoming photovoltaic revolution. Our group has been exploring constructive routes to build all‐weather solar cells so that these advanced photovoltaic technologies can be an indication for global solar industry in bringing down the cost of energy harvesting. How the all‐weather solar cells are built without reducing photo performances and why such architectures can realize electricity outputs with no visible‐light are discussed. Potential pathways and opportunities to enrich all‐weather solar cell families are envisaged. The aspects discussed here may enable researchers to develop undiscovered abilities and to explore wide applications of advanced photovoltaics.
B‐Site Cation Ordered Double Perovskites as Efficient and Stable Electrocatalysts for Oxygen Evolution Reaction
Authors: Sun Hainan , Chen Gao , Zhu Yinlong , Liu Bo , Zhou Wei , Shao Zongping 
Published: March 2017

AbstractSimple disordered perovskite oxides have been intensively exploited as promising electrocatalysts for the oxygen evolution reaction (OER) towards their application in water splitting, reversible fuel cells, and rechargeable metal‐air batteries. Here, the B‐site cation‐ordered double perovskites Ba2BixSc0.2Co1.8−xO6−δ, with two types of cobalt local environments, are demonstrated to be superior electrocatalysts for OER in alkaline solution, demonstrating ultrahigh catalytic activity. In addition, no obvious performance degradation is observed for the Ba2Bi0.1Sc0.2Co1.7O6−δ sample after a continuous chronopotentiometry test. The critical role of the ordered [Co2+] and [Sc3+, Bi5+, Co3+] dual environments in improving OER activity is exhibited. These results indicate that B‐site cation‐ordered double perovskite oxides may represent a new class of promising electrocatalysts for the OER in sustainable energy storage and conversion systems.
Optimal Design of Laboratory and Pilot‐Plant Experiments Using Multiobjective Optimization
Authors: Forte Esther , von Harbou Erik , Burger Jakob , Asprion Norbert , Bortz Michael 
Published: March 2017

AbstractPerforming an experimental design prior to the collection of data is in most circumstances important to ensure efficiency. The focus of this work is the combination of model‐based and statistical approaches to optimal design of experiments. The knowledge encoded in the model is used to identify the most interesting range for the experiments via a Pareto optimization of the most important conflicting objectives. Analysis of the trade‐offs found is in itself useful to design an experimental plan. This can be complemented using a factorial design in the most interesting part of the Pareto frontier.
UbFluor: A Fluorescent Thioester to Monitor HECT E3 Ligase Catalysis
Authors: Krist David T. , Foote Peter K. , Statsyuk Alexander V. 
Published: March 2017

AbstractHECT E3 ubiquitin ligases (∼28 are known) are associated with many phenotypes in eukaryotes and are important drug targets. However, assays used to screen for small molecule inhibitors of HECT E3s are complex and require ATP, Ub, E1, E2, and HECT E3 enzymes, producing three covalent thioester enzyme intermediates E1∼Ub, E2∼Ub, and HECT E3∼Ub (where ∼ indicates a thioester bond), and mixtures of polyubiquitin chains. To reduce the complexity of the assay, we developed a novel class of fluorescent probes, UbFluor, that act as mechanistically relevant pseudosubstrates of HECT E3s. These probes undergo a direct transthiolation reaction with the catalytic cysteine of HECT E3s, producing the catalytically active HECT E3∼Ub thioester accompanied by fluorophore release. Thus, a fluorescence polarization assay can continuously monitor UbFluor consumption by HECT E3s, and changes in UbFluor consumption rendered by biochemical point mutations or small molecule modulation of HECT E3 activity. © 2017 by John Wiley & Sons, Inc.
One‐Time Password Generation and Two‐Factor Authentication Using Molecules and Light
Authors: Naren Gaowa , Li Shiming , Andréasson Joakim 
Published: March 2017

AbstractHerein, we report the first example of one‐time password (OTP) generation and two‐factor authentication (2FA) using a molecular approach. OTPs are passwords that are valid for one entry only. For the next login session, a new, different password is generated. This brings the advantage that any undesired recording of a password will not risk the security of the authentication process. Our molecular realization of the OTP generator is based on a photochromic molecular triad where the optical input required to set the triad to the fluorescent form differs depending on the initial isomeric state.
Analysis of mtDNA/nDNA Ratio in Mice
Authors: Quiros Pedro M. , Goyal Aashima , Jha Pooja , Auwerx Johan 
Published: March 2017

AbstractMitochondrial DNA (mtDNA) lacks the protection provided by the nucleosomes in the nuclear DNA and does not have a DNA repair mechanism, making it highly susceptible to damage, which can lead to mtDNA depletion. mtDNA depletion compromises the efficient function of cells and tissues and thus impacts negatively on health. Here, we describe a brief and easy protocol to quantify mtDNA copy number by determining the mtDNA/nDNA ratio. The procedure has been validated using a cohort of young and aged mice. © 2017 by John Wiley & Sons, Inc.
A Mouse Model for Ocular Surface Staphylococcus aureus Infection
Authors: Zhang Zhiyong , Abdel‐Razek Osama , Wang Guirong 
Published: March 2017

AbstractCreation of an appropriate animal model that accurately reflects the disease and host immune response to bacterial infection in humans is a major challenge in ocular‐surface infection research. For decades, mice have been the ideal small animal model for ocular‐surface infection research because of the availability and relatively low cost of various genetic backgrounds, targeted defects, and immunologic reagents. By employing different combinations of mouse and bacterial strains, murine infection models can be used to explore a complete picture of bacterial infection and innate immunity of the ocular surface. A murine model of Staphylococcus aureus infection under normal ocular circumstances is presented here as a convenient and tractable model system in which to study mammalian host responses to pathogens. © 2017 by John Wiley & Sons, Inc.
Using Morpholinos to Control Gene Expression
Authors: Moulton Jon D. 
Published: March 2017

AbstractMorpholino oligonucleotides are stable, uncharged, water‐soluble molecules used to block complementary sequences of RNA, preventing processing, read‐through, or protein binding at those sites. Morpholinos are typically used to block translation of mRNA and to block splicing of pre‐mRNA, though they can block other interactions between biological macromolecules and RNA. Morpholinos are effective, specific, and lack non‐antisense effects. They work in any cell that transcribes and translates RNA, but must be delivered into the nuclear/cytosolic compartment to be effective. Morpholinos form stable base pairs with complementary nucleic acid sequences but apparently do not bind to proteins to a significant extent. They are not recognized by any proteins and do not undergo protein‐mediated catalysis—nor do they mediate RNA cleavage by RNase H or the RISC complex. This work focuses on techniques and background for using Morpholinos. © 2017 by John Wiley & Sons, Inc.
Synthesis of Geranyl‐2‐Thiouridine‐Modified RNA
Authors: Wang Rui , Haruehanroengra Phensinee , Sheng Jia 
Published: March 2017

AbstractThis unit describes the chemical synthesis of the S‐geranyl‐2‐thiouridine (ges2U) phosphoramidite and its incorporation into RNA oligonucleotides through solid‐phase synthesis. Starting from the 2‐thiouracil nucleobase and the protected ribose, the 2‐thiouridine is synthesized and the geranyl functionality is introduced into the 2‐thio position by using geranyl bromide as the geranylating reagent before the conversion of this modified nucleoside into a phosphoramidite building block. The modified phosphoramidite is used to make the geranyl‐RNA oligonucleotides with a solid‐phase DNA synthesizer. These RNA strands are then purified by ion‐exchange HPLC before further structural and functional studies, such as base pairing and enzyme recognition, can be done. © 2017 by John Wiley & Sons, Inc.
Characterization of Quadruplex DNA Structure by Circular Dichroism
Authors: del Villar‐Guerra Rafael , Gray Robert D. , Chaires Jonathan B. 
Published: March 2017

AbstractCircular dichroism (CD) is a phenomenon that arises from the differential absorption of left‐ and right‐handed circularly polarized light, and may be seen with optically active molecules. CD spectroscopy provides useful spectral signatures for biological macromolecules in solution, and provides low‐resolution structural information about macromolecular conformation. CD spectroscopy is particularly useful for monitoring conformational changes in macromolecules upon environmental perturbations. G‐quadruplex structures show unique CD spectral signatures, and CD is an important tool for characterizing their formation and global structure. This protocol offers step‐by‐step methods for determining reliable and reproducible CD spectra of quadruplex structures and normalizing the spectra for presentation. CD spectra properly normalized with respect to quadruplex concentration and path length are required to facilitate accurate comparison of results among laboratories. The standard operating procedures proposed are recommended to make such comparison accurate and informative. © 2017 by John Wiley & Sons, Inc.
Facile Access to Bromonucleosides Using Sodium Monobromoisocyanurate (SMBI)
Authors: Maity Jyotirmoy , Srivastava Smriti , Sanghvi Yogesh S. , Prasad Ashok K. , Stromberg Roger 
Published: March 2017

AbstractBromonucleosides constitute a significant class of molecules and are well known for their biological activity. 5‐Bromouridine, 5‐bromo‐2′‐deoxyuridine, 5‐bromouridine‐5′‐triphosphate, and nucleotides containing 5‐bromouridine have been tested and used for numerous biological studies. 8‐Bromopurine nucleosides have been used as essential precursors for the synthesis of nucleosides with fluorescent properties. This unit describes protocols for the synthesis of bromonucleosides using sodium monobromoisocyanurate (SMBI) in a straightforward way. Reactions are carried out at room temperature, and aqueous solvent mixtures are used to dissolve the nucleosides. Sodium azide is used as catalyst for the bromination of pyrimidine nucleosides, and no catalyst is necessary for the bromination of purine nucleosides. Unprotected 2′‐deoxy pyrimidine and 2′‐deoxy purine nucleosides are treated with SMBI to afford C‐5 bromo pyrimidine and C‐8 bromo purine nucleosides, respectively. This methodology has been found to be efficient for the synthesis of bromonucleosides on gram scale with consistently high yields. © 2017 by John Wiley & Sons, Inc.
Screening the Effect of Water Vapour on Gas Adsorption Performance: Application to CO2 Capture from Flue Gas in Metal–Organic Frameworks
Authors: Chanut Nicolas , Bourrelly Sandrine , Kuchta Bogdan , Serre Christian , Chang Jong‐San , Wright Paul A. , Llewellyn Philip L. 
Published: March 2017

AbstractA simple laboratory‐scale protocol that enables the evaluation of the effect of adsorbed water on CO2 uptake is proposed. 45 metal–organic frameworks (MOFs) were compared against reference zeolites and active carbons. It is possible to classify materials with different trends in CO2 uptake with varying amounts of pre‐adsorbed water, including cases in which an increase in CO2 uptake is observed for samples with a given amount of pre‐adsorbed water. Comparing loss in CO2 uptake between “wet” and “dry” samples with the Henry constant calculated from the water adsorption isotherm results in a semi‐logarithmic trend for the majority of samples allowing predictions to be made. Outliers from this trend may be of particular interest and an explanation for the behaviour for each of the outliers is proposed. This thus leads to propositions for designing or choosing MOFs for CO2 capture in applications where humidity is present.
Production and Application of Lignosulfonates and Sulfonated Lignin
Authors: Aro Thomas , Fatehi Pedram 
Published: March 2017

AbstractLignin is the largest reservoir of aromatic compounds on earth and has great potential to be used in many industrial applications. Alternative methods to produce lignosulfonates from spent sulfite pulping liquors and kraft lignin from black liquor of kraft pulping process are critically reviewed herein. Furthermore, options to increase the sulfonate contents of lignin‐based products are outlined and the industrial attractiveness of them is evaluated. This evaluation includes sulfonation and sulfomethylation of lignin. To increase the sulfomethylation efficiency of lignin, various scenarios, including hydrolysis, oxidation, and hydroxymethylation, were compared. The application of sulfonated lignin‐based products is assessed and the impact of the properties of these products on the characteristics of their end‐use application is critically evaluated. Sulfonated lignin‐based products have been used as dispersants in cement admixtures and dye solutions more than other applications, and their molecular weight and degree of sulfonation were crucial in determining their efficiency. The use of lignin‐based sulfonated products in composites may result in an increase in the hydrophilicity of some composites, but the sulfonated products may need to be desulfonated with an alkali and/or oxygen prior to their use in composites. To be used as a flocculant, sulfonated lignin‐based products may need to be cross‐linked to increase their molecular weight. The challenges associated with the use of lignin‐based products in these applications are comprehensively discussed herein.
Contact networks reveal potential for interspecific interactions of sympatric wild felids driven by space use
Authors: Lewis Jesse S. , Logan Kenneth A. , Alldredge Mat W. , Theobald David M. , VandeWoude Sue , Crooks Kevin R. 
Published: March 2017

AbstractCompetitive interactions between species are fundamental to understanding species assemblages, community dynamics, and ecological processes. Anthropogenic landscape change, particularly resulting from urbanization, can alter interspecific interactions; however, different forms of urbanization are predicted to have contrasting effects on competitive interactions. We developed contact networks between bobcats and pumas to evaluate (1) the potential for interspecific interactions between wild felids and (2) how space‐use metrics might change along the urban gradient, including low‐density exurban development, wildland–urban interface, and wildland habitat, at both the population and individual level. We used an extensive telemetry data set for bobcats and pumas across multiple study areas to evaluate four space‐use metrics: space‐use overlap (used to define potential interactions among animals) and three additional contact network metrics, including degree (the number of potentially interacting animals), in‐strength (sum of space‐use overlap for animals), and equivalent social connectivity (ESC; considering both space‐use extent and the amount of space‐use overlap). Space‐use extent was an important predictor of potential social interactions as measured by space‐use metrics. Bobcats appeared to have a greater opportunity to interact with female pumas based on space‐use overlap, degree, and in‐strength, which demonstrates that relative scale of space‐use extent among animals could be important for understanding interactions; ESC, however, was greater between bobcats and male pumas, likely due to the larger space‐use extent by male compared to female pumas and the positive relationship between space‐use extent and ESC. In addition, pumas and male bobcats exhibited a greater opportunity to interact, based on space‐use overlap, degree, and in‐strength, and demonstrated higher ESC compared to female bobcats. Counter to our predictions, felids associated with urbanized grids or with greater amounts of urbanization in their extent of space use did not appear to exhibit greater values of space‐use metrics compared to animals with less exposure to urbanization; these results appear consistent with previous research evaluating population characteristics of felids across broad scales in our study areas. Greater ESC for male pumas and male bobcats suggests that males could be particularly important for facilitating connectivity of some ecological processes, such as the transmission of disease, through interspecific contact networks.
Asymmetry of weathering‐limited hillslopes: the importance of diurnal covariation in solar insolation and temperature
Authors: Pelletier Jon D. , Swetnam Tyson L. 
Published: March 2017

AbstractHillslope asymmetry, i.e. variation in hillslope form as a function of slope aspect and/or mean solar insolation, has been documented in many climates and geologic contexts. Such patterns have the potential to help us better understand the hydrologic, ecologic, and geomorphologic processes and feedbacks operating on hillslopes. Here we document asymmetry in the fraction of hillslope relief accommodated by cliffs in weathering‐limited hillslopes of drainage basins incised into the East Kaibab Monocline (northern Arizona) and Raplee Ridge Monocline (southern Utah) of the southern Colorado Plateau. We document that south‐ and west‐facing hillslopes have a larger proportion of hillslope relief accommodated by cliffs compared with north‐ and east‐facing hillslopes. Cliff abundance correlates positively with mean solar insolation and, by inference, negatively with soil/rock moisture. Solar insolation control of hillslope asymmetry is an incomplete explanation, however, because it cannot account for the fact that the greatest asymmetry occurs between southwest‐ and northeast‐facing hillslopes rather than between south‐ and north‐facing hillslopes in the study sites. Modeling results suggest that southwest‐facing hillslopes are more cliff‐dominated than southeast‐facing hillslopes of the same mean solar insolation in part because potential evapotranspiration rates, which control the soil/rock moisture that drives weathering, are controlled by the product of solar insolation and a nonlinear function of surface temperature, together with the fact that southwest‐facing hillslopes receive peak solar insolation during warmer times of day compared with southeast‐facing hillslopes. The dependence of water availability on both solar insolation and surface temperature highlights the importance of the diurnal cycle in controlling water availability, and it provides a general explanation for the fact that vegetation cover tends to exhibit the greatest difference between northeast‐ and southwest‐facing hillslopes in the Northern Hemisphere and between southeast‐ and northwest‐facing hillslopes in the Southern Hemisphere. Copyright © 2017 John Wiley & Sons, Ltd.
Chronic effects of copper in oysters Crassostrea hongkongensis under different exposure regimes as shown by NMR-based metabolomics
Authors: Cao Chen , Wang Wen-Xiong 
Published: March 2017

Abstract

Traditional metal toxicity tests on organisms have mainly focused on continuous exposure at a fixed concentration. However, organisms are more likely exposed to pollutants intermittently in estuarine environments that are significantly impacted by anthropogenic activity. The present study examined whether different copper (Cu) exposure regimes at an equivalent dose can induce different metabolomics effects on the oysters. An estuarine oyster Crassostrea hongkongensis was exposed to Cu continuously or intermittently at an equal dose (time × concentration) for 6 wk. Continuous exposure regimes included 2 doses of 3.3 μg/L for 24 h and 20 μg/L for 24 h, with corresponding equal doses of 2 intermittent exposure regimes of 20 μg/L for 4 h and 120 μg/L for 4 h, respectively. Time-course measurements suggested that Cu bioaccumulation was comparable at equal low doses between the continuous regime (3.3 μg/L for 24 h) and the intermittent regime (20 μg/L for 4 h), but there was considerable difference for the high dose under different regimes. Nuclear magnetic resonance (NMR)-based metabolomics suggested that continuous and intermittent Cu exposures led to similar metabolite variation pattern in gills at an equal high dose, including decreased amino acids (e.g., aspartate, glycine, isoleucine, leucine, lysine, phenylalanine, threonine, and valine), lower energy-related compounds (e.g., adenosine triphosphate/adenosine diphosphate, acetate, citrate, and glycogen), and altered osmolytes (e.g., homarine and taurine). These biomarkers indicated disturbance of osmotic regulation and energy metabolism induced by Cu exposure regardless of regime. In addition, the 4-h intermittent Cu exposure resulted in slightly fewer adverse effects compared with the corresponding equal-dose continuous exposure. Oysters appeared to recover during the intervals of Cu exposure. The results indicated that metabolomic effects induced by Cu were more dose dependent than the Cu exposure regime. Environ Toxicol Chem 2017;36:2428–2435. © 2017 SETAC