bluuebunny/crossref_metadata_2025_split huggingface dataset:
Protein Structural Ensembles Visualized by Solvent Paramagnetic Relaxation Enhancement
Authors: Gong Zhou , Gu Xin‐Hua , Guo Da‐Chuan , Wang Jin , Tang Chun 
Published: December 2016

AbstractA protein can be in different conformations when fulfilling its function. Yet depiction of protein structural ensembles remains difficult. Here we show that the accurate measurement of solvent paramagnetic relaxation enhancement (sPRE) in the presence of an inert paramagnetic cosolute allows the assessment of protein dynamics. Demonstrated with two multi‐domain proteins, we present a method to characterize protein microsecond–millisecond dynamics based on the analysis of the sPRE. Provided with the known structures of a protein, our method uncovers an ensemble of structures that fully accounts for the observed sPRE. In conjunction with molecular dynamics simulations, our method can identify protein alternative conformation that has only been theorized before. Together, our method expands the application of sPRE beyond structural characterization of rigid proteins and complements the established PRE NMR technique.
Bioreaction Engineering Leading to Efficient Synthesis of L‐Glyceraldehyd‐3‐Phosphate
Authors: Molla Getachew S. , Kinfu Birhanu M. , Chow Jennifer , Streit Wolfgang , Wohlgemuth Roland , Liese Andreas 
Published: December 2016

AbstractEnantiopure L‐glyceraldehyde‐3‐phosphate (L‐GAP) is a useful building block in natural biological and synthetic processes. A biocatalytic process using glycerol kinase from Cellulomonas sp. (EC 2.7.1.30) catalyzed phosphorylation of L‐glyceraldehyde (L‐GA) by ATP is used for the synthesis of L‐GAP. L‐GAP has a half‐life of 6.86 h under reaction conditions. The activity of this enzyme depends on the Mg2+ to ATP molar ratio showing maximum activity at the optimum molar ratio of 0.7. A kinetic model is developed and validated showing a 2D correlation of 99.9% between experimental and numerical data matrices. The enzyme exhibits inhibition by ADP, AMP, methylglyoxal and Ca2+, but not by L‐GAP and inorganic orthophosphate. Moreover, equal amount of Ca2+ exerts a different degree of inhibition relative to the activity without the addition of Ca2+ depending on the Mg2+ to ATP molar ratio. If the Mg2+ to ATP molar ratio is set to be at the optimum value or less, inorganic hexametaphosphate (PPi6) suppresses the enzyme activity; otherwise PPi6 enhances the enzyme activity. Based on reaction engineering parameters such as conversion, selectivity and specific productivity, evaluation of different reactor types reveals that batchwise operation via stirred‐tank reactor is the most efficient process for the synthesis of L‐GAP.
Systematic interpolation method predicts protein chromatographic elution with salt gradients, pH gradients and combined salt/pH gradients
Authors: Creasy Arch , Barker Gregory , Carta Giorgio 
Published: December 2016

AbstractA methodology is presented to predict protein elution behavior from an ion exchange column using both individual or combined pH and salt gradients based on high‐throughput batch isotherm data. The buffer compositions are first optimized to generate linear pH gradients from pH 5.5 to 7 with defined concentrations of sodium chloride. Next, high‐throughput batch isotherm data are collected for a monoclonal antibody on the cation exchange resin POROS XS over a range of protein concentrations, salt concentrations, and solution pH. Finally, a previously developed empirical interpolation (EI) method is extended to describe protein binding as a function of the protein and salt concentration and solution pH without using an explicit isotherm model. The interpolated isotherm data are then used with a lumped kinetic model to predict the protein elution behavior. Experimental results obtained for laboratory scale columns show excellent agreement with the predicted elution curves for both individual or combined pH and salt gradients at protein loads up to 45 mg/mL of column. Numerical studies show that the model predictions are robust as long as the isotherm data cover the range of mobile phase compositions where the protein actually elutes from the column.
A Metal‐Free, Nonconjugated Polymer for Solar Photocatalysis
Authors: Irigoyen‐Campuzano Rafael , González‐Béjar María , Pino Eduardo , Proal‐Nájera Jose B. , Pérez‐Prieto Julia 
Published: December 2016

AbstractHeterogeneous catalysts that can absorb light over the solar range are ideal for green photocatalysis. Recently, attention has been directed towards the generation of novel solar‐light photocatalysts, in particular, metal‐free polymers. Herein, it is demonstrated that a metal‐free, nonconjugated, anthraquinone‐based copolymer (poly[1,4‐diamine‐9,10‐dioxoanthracene‐alt‐(benzene‐1,4‐dioic acid)] (COP)) with a strong absorption in the visible region is effective as a sunlight heterogeneous photocatalyst. As a proof of concept, it has been used to mineralize 2,5‐dichlorophenol (2,5‐DCP) in water under air and sunlight irradiation. The photocatalytic efficiency of COP compares well with that of TiO2‐P25 when the reaction is carried out in a solar photoreactor in acid medium. Steady‐state and time‐resolved (absorption and emission) studies performed on COP suspended in 6:4 DMF/H2O have provided valuable information about the COP species generated under different pH conditions. Steady‐state absorption and fluorescence data are consistent with the existence of a tautomeric equilibrium between the 9,10‐keto and 1,10‐iminoketo quinoid forms for the anthraquinone in the ground state. Moreover, in basic media, transient absorption measurements showed the presence of two bands ascribed to the tautomeric triplet excited states, whereas only one of the triplets was observed in acid medium. A mechanism for the photocatalyzed degradation of 2,5‐DCP by COP is proposed on the basis of these observations.
Modulation of Excess Electron Transfer through LUMO Gradients in DNA Containing Phenanthrenyl Base Surrogates
Authors: Roethlisberger Pascal , Kaliginediand Veerabhadrarao , Leumann Christian J. 
Published: December 2016

AbstractThe modulation of excess electron transfer (EET) within DNA containing a dimethylaminopyrene (C‐AP) as an electron donor and 5‐bromouracil (BrdU) as an electron acceptor through phenanthrenyl pairs (phen‐R) could be achieved by modifying the phenanthrenyl base surrogates with electron withdrawing and donating groups. Arranging the phenanthrenyl units to form a descending LUMO gradient increased the EET efficiency compared to the electron transfer through uniform LUMOs or an ascending LUMO gradient.
Mild Oxalic‐Acid‐Catalyzed Hydrolysis as a Novel Approach to Prepare Cellulose Nanocrystals
Authors: Xu Wenyang , Grénman Henrik , Liu Jun , Kronlund Dennis , Li Bin , Backman Peter , Peltonen Jouko , Willför Stefan , Sundberg Anna , Xu Chunlin 
Published: December 2016

AbstractThe traditional method to isolate cellulose nanocrystals (CNCs) is to subject cellulosic materials to strong acid hydrolysis by mineral acids, which usually causes problems such as corrosion of equipment, the need for large amounts of water, the difficulty of acid recovery, and over‐degradation of cellulose. Thus, a green and sustainable approach for the preparation of CNCs was developed where mild acid hydrolysis with diluted oxalic acid was used. The reaction kinetics of different preparation parameters, such as reaction temperature, oxalic acid dose, addition of HCl, and reaction time were thoroughly investigated. A high yield of up to 85 % was achieved by mild oxalic acid hydrolysis in comparison to the yield of 35 % using the most common approach with sulfuric acid hydrolysis. The CNCs from the above approach have a high thermal stability, that is, a maximum thermal degradation temperature of 350 °C in comparison to 200 °C when sulfuric acid hydrolysis was used. Importantly, oxalic acid solutions were readily recovered, and exhibited consistently high performance in several continuous runs of reaction. The hydrolysates contained mostly monomeric sugars, which could be further utilized for chemical or biofuel production.
Precursor States of Organic Adsorbates on Semiconductor Surfaces are Chemisorbed and Immobile
Authors: Pecher Lisa , Tonner Ralf 
Published: December 2016

AbstractThe front cover artwork is provided by Aaron Beller (Faculty of Arts, Philipps‐Universität Marburg) in collaboration with the authors. The image shows how the firm grip of a dative bond, indicated by a black arrow, prevents a weakly adsorbed ethylene molecule from moving on the Si(001) surface. Read the full text of the article at 10.1002/cphc.201601129.
Supramolecular Isoguanosine Assemblies Form Hydrogels with Excellent Long‐Term Stability
Authors: Zhao Hang , Schäfer Andreas H. , Seela Frank 
Published: December 2016

AbstractSupramolecular nucleoside‐based hydrogels have the potential to be utilized in drug delivery, regenerative medicine and for the construction of nanoscopic devices. Isoguanosine, its 2′‐deoxyribonucleoside and the 2′‐deoxy‐2′‐fluororibonucleoside form hydrogels in alkali metal salt solutions. Gel stability depends on the metal ions used (Li+, Na+, K+, Rb+, Cs+). All isoguanosine gels show long‐term stability of several months, whereas guanosine gels collapse within minutes or hours. Rheological data confirm a 15 times higher hydrogel stability for isoguanosine compared to guanosine. Isoguanosine gel stability covers a broad pH range (pH 3–10), and the stability at physiological Na+ ion concentration is striking. SEM images reveal that isoguanosine self‐assembles into helical stacked fibers that are interconnected whereas guanosine forms discrete ribbons. Moreover, isoguanosine gels display excellent loading and release ability for small molecules.
Strategy for Extending the Stability of Bio‐oil‐Derived Phenolic Oligomers by Mild Hydrotreatment with Ionic‐Liquid‐Stabilized Nanoparticles
Authors: Kim Kwang Ho , Brown Robert C. , Daugaard Tannon , Tivol William F. , Auer Manfred , Simmons Blake , Singh Seema 
Published: December 2016

AbstractThe development of catalytic transformations and processes is essential to utilize bio‐oil and lignin derivatives. Metal nanoparticles (M‐NPs) stabilized in ionic liquids (ILs) are promising for the catalytic hydrotreatment of bio‐oil because the properties of the catalyst system can be customized by combining the appropriate IL and metal nanoparticles. Herein, we demonstrate an experimental approach to stabilize lignin‐derived phenolics isolated from bio‐oil with ruthenium NPs stabilized by an ionic copolymer in 1‐ethyl‐3‐methylimidazolium acetate ([C2C1Im][OAc]). The mild hydrotreatment of phenolic oligomers (POs) was performed with the synthesized M‐NP catalyst at 100 °C for 6 h. Hydrotreatment of the POs resulted in enhanced thermal stability of the POs by as much as a factor of three, as determined by the aging index and by reducing reactive functionalities, which was also confirmed by NMR spectroscopy and GC analysis. The results support our hypothesis that M‐NPs stabilized in ILs can effectively stabilize POs under mild conditions, which could be applicable to any lignin‐derived phenolic.
Anodic Behavior of the Aluminum Current Collector in Imide‐Based Electrolytes: Influence of Solvent, Operating Temperature, and Native Oxide‐Layer Thickness
Authors: Meister Paul , Qi Xin , Kloepsch Richard , Krämer Elisabeth , Streipert Benjamin , Winter Martin , Placke Tobias 
Published: December 2016

AbstractThe inability of imide salts to form a sufficiently effective passivation layer on aluminum current collectors is one of the main obstacles that limit their broad application in electrochemical energy‐storage systems. However, under certain circumstances, the use of electrolytes with imide electrolyte salts in combination with the aluminum current collector is possible. In this contribution, the stability of the aluminum current collector in electrolytes containing either lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) or lithium fluorosulfonyl‐(trifluoromethanesulfonyl) imide (LiFTFSI) as conductive salt was investigated by electrochemical techniques, that is, cyclic voltammetry (CV) and chronocoulometry (CC) in either room‐temperature ionic liquids or in ethyl methyl sulfone. In particular, the influence of the solvent, operating temperature, and thickness of the native oxide layer of aluminum on the pit formation at the aluminum current collector surface was studied by means of scanning electron microscopy. In general, a more pronounced aluminum dissolution and pit formation was found at elevated temperatures as well as in solvents with a high dielectric constant. An enhanced thickness of the native aluminum oxide layer increases the oxidative stability versus dissolution. Furthermore, we found a different reaction rate depending on dwell time at the upper cut‐off potential for aluminum dissolution in TFSI‐ and FTFSI‐based electrolytes during the CC measurements; the use of LiFTFSI facilitated the dissolution of aluminum compared to LiTFSI. Overall, the mechanism of anodic aluminum dissolution is based on: i) the attack of the Al2O3 surface by acidic species and ii) the dissolution of bare aluminum into the electrolyte, which, in turn, is influenced by the electrolyte's dielectric constant.
A series‐coupled LC quadrature oscillator using phase/amplitude calibration
Authors: Ghonoodi Hojat , Naimi Hossein Miar 
Published: December 2016

SummaryIn this paper, an analytic approach for the estimation of the phase and amplitude error in series coupled LC quadrature oscillator (SC‐QO) is proposed. The analysis results show that imbalances in source voltage of coupling transistor because of mismatches between LC tanks are the main source of the phase and amplitude error in this oscillator. For compensation of the phase and amplitude error, a phase and amplitude‐tunable series coupled quadrature oscillator is designed in this paper. A phase shift generation circuit, designed using an added coupling transistor, can control the coupling transistor source voltage. The phase and amplitude error can simply be controlled and removed by tuning the phase shifter, while this correction does not have undesirable impact on phase noise. In fact, the proposed SC‐QO generates a phase shift in the output current, which reduces the resonator phase shift (RPS) and improves phase noise. The phase and amplitude tunable SC‐QO is able to correct the phase error up to ±12°, while amplitude imbalances are reduced as well. To evaluate the proposed analysis, a 4.5‐GHz CMOS SC‐QO is simulated using the practical 0.18‐μm TSMC CMOS technology with a current consumption of 2 mA at 1.8‐V supply voltage. Copyright © 2016 John Wiley & Sons, Ltd.
Characterizing severe and enduring anorexia nervosa: An empirical approach
Authors: Wildes Jennifer E. , Forbush Kelsie T. , Hagan Kelsey E. , Marcus Marsha D. , Attia Evelyn , Gianini Loren M. , Wu Wei 
Published: December 2016

AbstractTargeted approaches for the treatment of severe and enduring anorexia nervosa (SE‐AN) have been recommended, but there is no consensus definition of SE‐AN to inform research and clinical practice. This study aimed to take initial steps toward developing an empirically based definition of SE‐AN by characterizing associations among putative indicators of severity and chronicity in eating disorders. Patients with AN (N = 355) completed interviews and questionnaires at treatment admission and discharge; height and weight were assessed to calculate body mass index (BMI). Structural equation mixture modeling was used to test whether associations among potential indicators of SE‐AN (illness duration, treatment history, BMI, binge eating, purging, quality‐of‐life) formed distinct subgroups, a single group with one or more dimensions, or a combination of subgroups and dimensions. A three‐factor (dimensional), two‐profile (categorical) mixture model provided the best fit to the data. Factor 1 included eating disorder behaviors; Factor 2 comprised quality‐of‐life domains; Factor 3 was characterized by illness duration, number of hospitalizations, and admission BMI. Profiles differed on eating disorder behaviors and quality‐of‐life, but not on indicators of chronicity or BMI. Factor scores, but not profile membership, predicted outcome at discharge from treatment. Data suggest that patients with AN can be classified on the basis of eating disorder behaviors and quality‐of‐life, but there was no evidence for a chronic subgroup of AN. Rather, indices of chronicity varied dimensionally within each class. Given that current definitions of SE‐AN rely on illness duration, these findings have implications for research and clinical practice.
Experimental and Neural Network Modeling of Partial Uptake for a Carbon Dioxide/Methane/Water Ternary Mixture on 13X Zeolite
Authors: Abdul Kareem Firas A. , Shariff Azmi M. , Ullah Sami , Garg Sahil , Dreisbach Frieder , Keong Lau Kok , Mellon Nurhayati 
Published: December 2016

AbstractIn this work, GERG2008 EoS embedded in a volumetric–gravimetric technique was utilized to measure multicomponent partial uptakes into the mixture. The sophisticated combination may overlap recent theoretical measurements and replace it with real‐time and experimental selective adsorption analysis. 13X zeolite was utilized as a solid adsorbent for the adsorption of binary and ternary CO2/CH4/H2O mixtures. Premixed and preloaded water vapor was studied at 323 K temperature and up to 10 bar pressure. The isotherms of individual components within the mixture were identified and compared to the adsorption data of the pure components for assured benchmarking and validation. Artificial neural network (ANN) modeling was used to predict ternary mixtures. The ANN results showed a good agreement with the experimental data. Moreover, simulated configurations by utilizing an ANN model reflected the high consistency. We identified the behavior of the single components in ternary and higher multicomponent mixtures.
Tailoring Electrocatalytic Properties of Solid Oxide Fuel Cell Composite Cathodes Based on (La0.8Sr0.2)0.95MnO3+δ and Doped Cerias Ce1–xLnxO2–δ (Ln=Gd, La, Er, Pr, Tb and x=0.1–0.2)
Authors: Navarrete L. , Balaguer M. , Vert V. B. , Serra J. M. 
Published: December 2016

AbstractComposites made of different doped cerias and (La0.8Sr0.2)0.95MnO3+δ were studied as potential solid oxide fuel cell cathodes. Tb, Pr, Gd and Er have been introduced as ceria dopants to enhance the electrocatalytic properties of (La0.8Sr0.2)0.95MnO3+δ composites fabricated within. Different electrochemical behaviors were observed for the studied composites depending on lanthanide cation nature, i.e., whether they can exhibit different oxidation states or not. Specifically, (La0.8Sr0.2)0.95MnO3+δ/ceria composites with a mixed valence dopants (Tb and Pr) in the CeO2 structure are the best performing and present a limiting step at low frequencies; whereas those with ceria‐doping elements with fixed oxidation state (Gd and Er) exhibit the limiting processes at higher frequencies. This fact is related to the higher magnitude of the TPB enlargement in the composite cathode achieved thanks to the promotion of mixed ionic‐electronic conductivity in the Pr/Tb‐doped ceria phase. The best cathode performance was obtained with (La0.8Sr0.2)0.95MnO3+δ_Ce0.8Pr0.2O2–δ cathodes with the lowest values for the polarization resistance in the 900–700 °C temperature range.
“I wish my people can be like the ducks”: Children's references to internal states with siblings and friends from early to middle childhood
Authors: Leach Jamie , Howe Nina , DeHart Ganie 
Published: December 2016

AbstractThe present study investigated children's internal state language during play with their sibling and friend across early and middle childhood. Specifically, the category type of internal state language (e.g., cognitions and goals), referent (e.g., own and other), and associations with children's birth order were examined. A total of 65 (T1: Time 1) and 46 (T2: Time 2) children were observed at age 4 and 3 years later when children were aged 7 with their sibling and with their friend in two separate play sessions at home. Videos were transcribed and coded for the frequency and category of internal state language. Children referenced cognitions more often with their sibling than friend at T2. Children's references to shared internal states (e.g., “we”) were more frequent at T2 than T1 across relationship contexts. Time effects were found when the category and referent of internal state language were cross‐tabulated (e.g., references to shared goals plus one's own cognitions were more characteristic at T2 than T1). Birth‐order effects were evident at T1 with younger children referencing goals and cognitions with their sibling more often than older children. Results provide new insight into children's use of internal state language across relationship contexts and developmental periods.HighlightThe purpose of the present study was to compare children's category type and referent of internal state language across sibling and friend relationships and from early to middle childhood. Results demonstrated that children showed higher rates of cognitive terms at middle childhood, particularly with their sibling, and referred to shared internal states more at middle childhood than early childhood. Findings highlight the importance of considering social context and a longitudinal design when observing children's internal state language during play.
Oil and gas development influences big‐game hunting in Wyoming
Authors: Dorning Monica A. , Garman Steven L. , Diffendorfer Jay E. , Semmens Darius J. , Hawbaker Todd J. , Bagstad Kenneth J. 
Published: December 2016

ABSTRACTDevelopment from extracting oil and gas resources can have unintended effects on multiple ecosystem functions, with cascading effects on wildlife, ecosystem services, and local economies. Big‐game hunting opportunities may be closely related to these effects, but empirical analyses of impacts of energy development on hunting are limited. We examined the influence of oil and gas development density on harvest efficiency, or harvest per unit of hunter effort, within all hunt areas in Wyoming, USA, from 2008 to 2014 for 3 big‐game species: elk (Cervus canadensis), mule deer (Odocoileus hemionus), and pronghorn (Antilocapra americana). Using harvest/hunter day as the response variable, we compared linear mixed‐effects models for each species that included total well density (i.e., all wells constructed up to the year of record), active well density (i.e., only those wells currently producing oil or gas in that year), or neither as a predictor variable. We used well densities as indicators of development in the absence of data specifying the locations of other oil and gas infrastructure (e.g., roads, well pads). Models also accounted for the fixed effects of road density, hunter density, proportion of the area that is public land with unrestricted hunter access, proportion of the area that is forested, year of observation, and random effects of variation among hunt areas nested within associated game herd units. Presence of oil and gas wells had a positive influence on harvest efficiency for elk and mule deer. Although there was no overall effect to pronghorn, there was a negative influence of wells on juvenile pronghorn harvest efficiency. Changes in harvest efficiency due to expanding oil and gas development could alter the time spent hunting by hunters and their chances of harvesting an animal. This could have subsequent impacts on hunter satisfaction, game populations, and economic revenue generated from recreational hunters. © 2016 The Wildlife Society.