bluuebunny/crossref_metadata_2025_split huggingface dataset:
The impact of interchain hydrogen bonding on β‐hairpin stability is readily predicted by molecular dynamics simulation
Authors: Niebling Stephan , Danelius Emma , Brath Ulrika , Westenhoff Sebastian , Erdélyi Máté 
Published: May 2015

ABSTRACTPeptides are frequently used model systems for protein folding. They are also gaining increased importance as therapeutics. Here, the ability of molecular dynamics (MD) simulation for describing the structure and dynamics of β‐hairpin peptides was investigated, with special attention given to the impact of a single interstrand sidechain to sidechain interaction. The MD trajectories were compared to structural information gained from solution NMR. By assigning frames from restraint‐free MD simulations to an intuitive hydrogen bond on/off pattern, folding ratios and folding pathways were predicted. The computed molecular model successfully reproduces the folding ratios determined by NMR, indicating that MD simulation may be straightforwardly used as a screening tool in β‐hairpin design. © The Authors. Biopolymers Published by Wiley Periodicals, Inc. Biopolymers (Pept Sci) 104: 703–706, 2015.
Water‐soluble chiral metallopeptoids
Authors: Baskin Maria , Maayan Galia 
Published: May 2015

ABSTRACTMetal ions play a significant role in the activity of biological systems including catalysis, recognition and folding. Therefore, introducing metal ions into peptidomimetic oligomers is a potential way for creating biomimetic metal complexes toward applications in sensing, recognition, drug design and catalysis. Herein we report the design, synthesis and characterization of water‐soluble chiral N‐substituted glycine oligomers, “peptoids,” with one and two distinct intramolecular binding sites for metal ions such as copper and cobalt. We demonstrate for the first time the incorporation of the chiral hydrophilic group (S)‐(+)‐1‐methoxy‐2‐propylamine (Nsmp) within peptoid sequences, which provides both chirality and water solubility. Two peptoids, a heptamer, and a dodecamer bearing two and four 8‐hydroxyquinoline (HQ) groups respectively as metal‐binding ligands, were synthesized on solid support using the submonomer approach. Using UV‐titrations and ESI‐MS analysis we demonstrate the creation of a novel metallopeptoid bearing two metal ions in distinct binding sites via intramolecular chelation. Exciton couplet circular dichroism (ECCD) demonstrated chiral induction from the chiral non‐helical peptoids to the metal centers. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 104: 577–584, 2015.
Untangling Self‐Blame and Mother‐Blame in Women's and Children's Perspectives on Maternal Protectiveness in Domestic Violence: Implications for Practice
Authors: Moulding Nicole T. , Buchanan Fiona , Wendt Sarah 
Published: May 2015

Research into maternal protectiveness in domestic violence has focused either on women's experiences of mothering or children's experiences of growing up in domestic violence. This paper reports on a qualitative research study with both mothers and individuals who grew up in domestic violence that sought to explore perspectives on, and experiences of, maternal protectiveness in the two groups. The study used a feminist social constructionist theoretical perspective and a relational empowerment methodology, and involved interviews with nine mothers and 16 individuals who grew up in domestic violence. Thematic analysis revealed the different ways that mothers and children approached the question of so‐called ‘failure to protect’. Analysis revealed that themes of self‐blame by the mothers and mother‐blame by those who grew up in domestic violence were common, with three main thematic categories capturing the ways in which blame was constructed: (1) centring feminine traits; (2) self‐blame and guilt; and (3) the double bind of protection. The paper explores the gendered discourses about mothering and femininity that frame practices of self‐blame and mother‐blame, elaborating the double bind of protection that women face. The paper also explores the implications for practitioners who work with domestic violence in balancing the need to strengthen connections between mothers and children and, at the same time, safeguard children. Copyright © 2015 John Wiley & Sons, Ltd.‘Thematic analysis revealed the different ways that mothers and children approached the question of so‐called ‘failure to protect’’Key Practitioner MessagesMothers commonly blame themselves for so-called ‘failure to protect’ their children in domestic violence.Individuals who grew up in violence often blame their mothers for ‘failure to protect’.Mother‐blame draws on a range of femininity and victim‐blaming discourses that can entangle women and children further in violence.Practitioners can encourage communication between mothers and children to repair relationships after violence.
Hydrogen Production by a Photosynthetic Bacterium: Some Analytical Solutions
Authors: Rasi Muthuramalingam , Rajendran Lakshmanan 
Published: May 2015

AbstractThe mathematical model for hydrogen production by the photosynthetic bacterium Rhodobacter capsulatus in a batch photobioreactor is discussed. An analytical method – the homotopy perturbation method – is presented to solve the nonlinear differential equations that describe the biomass formation, substrate utilization, and hydrogen production with respect to time. Approximate analytical expressions for the concentrations of biomass, substrate and hydrogen are derived for various values of the relevant parameters. The analytical results are compared with experimental data. In addition, the sensitivity of the kinetic parameters is also analyzed. The time required to achieve the maximum growth of biomass and complete degradation of the substrate is reported.
Smart Hybrid Polymers for Advanced Damascene Electroplating: Combination of Superfill and Leveling Properties
Authors: Hai Nguyen Thi Minh , Broekmann Peter 
Published: May 2015

AbstractA successful bottom‐up fill of single Damascene test features is achieved by using a two‐component additive package consisting of bis‐(sodium‐sulfopropyl)‐disulfide (SPS) and Imep polymers (polymerizates of imidazole and epichlorohydrin). In addition, a remarkable leveling effect is observed. Clearly, the Imep additive combines bottom‐up fill capabilities with leveling characteristics in one single polymer component. These unique hybrid properties of the Imep are rationalized on the basis of an extended N‐NDR (N‐shaped negative differential resistance) being present in the linear‐sweep voltammogram of the SPS/Imep additive system during Cu electrodeposition.
Homogenisieren einer nichtnewtonschen Petrolkoks/Wasser‐Suspension mit zweiflügligen Axialrührern
Authors: Altwasser Sebastian , Sperling Reinhard , Wollny Stefan , Klatt Detlef 
Published: May 2015

AbstractPetrolkoks/Wasser‐Suspension können in einem Brennprozess zur Synthesegas‐Herstellung verwendet werden. Der nichtnewtonsche Charakter der Suspension kann zur Bildung von Kavernen führen, wodurch aufgrund von Konzentrationsgradienten ein ungleichmäßiges Verbrennen resultiert. Eine Machbarkeitsstudie für die Verwendung eines RUAX®‐Rührers als zwei‐ und dreistufiges System mit unterschiedlichen Drehzahlen für das Suspendieren von Petrolkoks in Wasser wird vorgestellt. Die Rheologie der Suspension wurde mit verschiedenen Messtechniken untersucht. In einem weiteren Schritt erfolgte die Durchführung von CFD‐Simulationen für verschiedene Konfigurationen. Die ermittelte Kavernengröße wird mit Ergebnissen eines Literaturmodells verglichen.
Basic design methodology for a prilling tower
Authors: Saleh Saad N. , Ahmed Shakir M. , Al‐mosuli Dawood , Barghi Shahzad 
Published: May 2015

AbstractA design methodology was developed for prilling towers based on simultaneous heat, mass, and momentum balances. Basic principles of the prilling process and related sub‐models were considered for production of relatively mono‐size prills. The method was employed in the design of a prilling tower for production of ammonium nitrate prills from a highly concentrated solution. A special showerhead spray, operating under laminar conditions in a Rayleigh jet break‐up regime, was designed to enhance production of mono‐size prills. Air was used at ambient conditions. The droplets leaving the showerhead fall through the air stream in a counter‐current fashion. Heat transfer from particles to air includes cooling in the fully liquid state, solidification, and cooling in the fully solid state.The Computational Fluid Dynamics (CFD) simulation revealed the formation of a quiescent zone around the nozzle discharge region, which had a significant effect on decreasing the secondary disintegration of the droplets, and hence narrowed down the size distribution towards the desired value. The size of the produced prills was larger than the predicted value due to the formation of ammonia bubbles inside the prills.
Novel surfactant delivery system for controlling surfactant adsorption onto solid surfaces. Part II: Dynamic adsorption tests
Authors: Alhassawi Hassan , Romero‐Zerón Laura 
Published: May 2015

AbstractDuring surfactant flooding in enhanced oil recovery (EOR), surfactant adsorption onto rock surfaces constitutes a serious shortcoming because as the chemical slug flows through the oil reservoir, surfactant is lost to adsorption before it reaches the target residual oil saturation zones, which renders the process technically inefficient and uneconomical.This work is the second phase of a wider study aimed at the evaluation of a new technology to control surfactant adsorption onto solid surfaces by using a surfactant delivery system based on surfactant/β‐CD inclusion complexes. This complexation was confirmed through surface tensiometry, 1H NMR and FTIR spectroscopy, and microscopic studies (TEM and SEM). The performance of the surfactant delivery system in controlling surfactant adsorption was evaluated through dynamic adsorption tests using different mixtures of solid adsorbents (sandstone, shale, and kaolinite).Dynamic adsorption data show reductions of surfactant adsorption ranging from 50–92 % for all the adsorbents tested; therefore, the surfactant delivery system seems to be highly effective in inhibiting surfactant adsorption onto solid surfaces. This new technology has great potential for EOR chemical flooding applications.
Tribology and oxidation studies of fatty acid sulfide derivatives synthesized via thiol‐ene “Click” additions
Authors: Sammaiah Arukali , Padmaja Korlipara V. , Prasad Rachapudi B. N. 
Published: May 2015

The synthesis of sulfide derivatives via thiol‐ene addition reactions of methyl oleate and methyl 10‐ undecenoate as substrates is reported. The substrate fatty acids contained a terminal double bond in methyl 10‐undecenoate and an internal double bond in methyl oleate. Thiol‐ene addition of unsaturated fatty acid ester derivatives with hydroxy and amine functionality on the fatty acids was carried out under thermal conditions. The synthesized products were characterized by 1H, 13C NMR, FT‐IR, and GC‐MS analysis and evaluated for their antioxidant, extreme pressure (EP), and antiwear (AW) properties in base oil namely, epoxy jatropha fatty acid n‐butyl esters (EJB). Synthesized products exhibited comparable antioxidant efficacy to butylated hydroxyl toluene (BHT). All four synthesized sulfide derivatives significantly enhanced the weld point of the base oil EJB and exhibited comparable performance to TCP (tricresyl phosphate) at 1 wt% level. Methyl 9(10)‐(2‐hydroxyethylthio) octadecanoate at 0.5% concentration exhibited considerable improvement in the wear scar of base oil from 0.834 to 0.422 mm. The synthesized sulfide derivatives have potential as multifunctional additives for biolubricant basestocks.Practical applications: Synthesis of multifunctional additives via thiol‐ene addition under thermal conditions. The prepared sulfide derivatives were found to exhibit good antioxidant, antiwear, and extreme pressure additives. The synthesized additives exhibited comparable performance to commercial additives. The products are potential biobased alternatives for commercial additives.Sulfide derivatives as multifunctional additives.
Ash Sintering Behavior of Lignite in Catalyzed Steam Gasification with Kaolin as Additive
Authors: Zhang Ji‐guang , Zhang Li , Yang Zhong‐qing , Yan Yun‐fei , Ran Jing‐yu 
Published: May 2015

AbstractAn investigation of the ash sintering characteristics of LLI lignite with kaolin additive during K2CO3‐catalyzed steam gasification was conducted in this study. The ash samples were prepared using a catalytic gasification system at 1073 K under steam atmosphere. Experiments on the sintering behavior were performed using a pressure‐drop sintering device under inert N2. Results showed that when increasing the concentration of K2CO3 from 0 to 10 wt %, the ash sintering temperature decreased and the ash molten degree become more serious. The potassium‐containing compounds arcanite and kaliophilite can trigger the occurrence of sintering on reactions with other minerals to facilitate the formation of liquid phases and then result in a lower ash sintering temperature. Besides, kaolin can increase ash sintering temperature and ease the melt degree of ashes. Kaolin can react with other minerals to generate more refractory silicon oxide and decrease the fluxing arcanite and amorphous materials in ashes.
Robust and Powerful Affected Sibpair Test for Rare Variant Association
Authors: Lin Keng‐Han , Zöllner Sebastian 
Published: May 2015

ABSTRACTAdvances in DNA sequencing technology facilitate investigating the impact of rare variants on complex diseases. However, using a conventional case‐control design, large samples are needed to capture enough rare variants to achieve sufficient power for testing the association between suspected loci and complex diseases. In such large samples, population stratification may easily cause spurious signals. One approach to overcome stratification is to use a family‐based design. For rare variants, this strategy is especially appropriate, as power can be increased considerably by analyzing cases with affected relatives. We propose a novel framework for association testing in affected sibpairs by comparing the allele count of rare variants on chromosome regions shared identical by descent to the allele count of rare variants on nonshared chromosome regions, referred to as test for rare variant association with family‐based internal control (TRAFIC). This design is generally robust to population stratification as cases and controls are matched within each sibpair. We evaluate the power analytically using general model for effect size of rare variants. For the same number of genotyped people, TRAFIC shows superior power over the conventional case‐control study for variants with summed risk allele frequency ; this power advantage is even more substantial when considering allelic heterogeneity. For complex models of gene‐gene interaction, this power advantage depends on the direction of interaction and overall heritability. In sum, we introduce a new method for analyzing rare variants in affected sibpairs that is robust to population stratification, and provide freely available software.
Quantitative assessment of CO2 storage capacity by using of hydrogeochemical and isotope data for deep saline aquifers
Authors: Li Yiman , Pang Zhonghe 
Published: May 2015

AbstractCO2 sequestration in deep saline aquifers presents a viable option for CO2 emissions mitigation while accurate evaluation of CO2 storage capacity is central to effective site selection. Existing methods are mostly based on consideration of trapping mechanisms, which is problematic in accurate determination of the storage efficiency factor and exposes results to considerable error. Many studies simply adopt DOE figures, which can't represent diverse geological conditions across the globe. A new geochemical‐based method is proposed which considers CO2 trapping states rather than trapping mechanisms. It is especially effective for site‐scale CO2 storage capacity calculation with single injection well and a timeframe of a hundred to a thousand years. This method considers injected CO2 trapped in forms of free state and soluble state, but excludes the mineral trapping state. Effective pore volume is calculated based on two simplified models of CO2 plume within effective affecting radius in which trigonal pyramidal and cylindrical models represent minimum and maximum volume, respectively. Calculations of free CO2 saturation and the ratio of dissolved inorganic carbonate contributed by CO2 dissolution are used to calculate effective CO2 storage capacity in forms of free and soluble state, respectively. Isotope and hydrogeochemical data changes pre‐ and post‐CO2 injection are used to calculate free CO2 saturation and ratio of dissolved inorganic carbonate contributed by CO2 dissolution. Numerical simulation with calibration by measured values and calculation of CO2 consumption per unit weight of rock is suggested to assess CO2 trapped by mineral state at timeframe of tens of thousands years.© 2015 Society of Chemical Industry and John Wiley & Sons, Ltd
Mode of formation of the Nile Gorge in northern Egypt: a study by DEM‐SRTM data and GIS analysis
Authors: Abdelkareem Mohamed , El‐Baz Farouk 
Published: May 2015

AbstractThis is an overview of the mode of formation of the Nile Gorge in northern Egypt. It is based on the interpretation of the Shuttle Radar Topography Mission (SRTM) data along with detailed analysis of landsat image, geological map and seismic data. The results show that the current course of the Nile was caused by a differential uplift of two plateaus: Ma'aza, to the east, and Western Desert plateau, to the west of the river. This uplift is caused by dynamic forces resulting from subsurface convection processes. It also contributed to the formation of several drainage systems, basins and structural features. Abundant faults and fractures that are parallel to the Nile Valley on both flanks that are associated with uplift are proven to be contemporaneous with formation of the river. We conclude that understanding of the uplift is crucial to visualizing the Nile course and its geodynamic formation. The information derived from the SRTM data reveals invaluable knowledge in support of the presented remotely sensed geological features. The paper clearly explains the stages of formation of the Nile segments in space and time and structural controls on the path of the Nile River in Egypt. Copyright © 2015 John Wiley & Sons, Ltd.
Physical Organic Chemistry by Any Other Name Would Smell as Sweet
Authors: Chapin Brette M. , Anslyn Eric V. 
Published: May 2015

AbstractThe techniques and thought processes of the field of physical organic chemistry, focused on small organic molecule structure and reactivity, have been taken up by numerous other fields, including, but not limited to, sensor design, organometallics, organic materials, organocatalysis, and supramolecular chemistry. The unifying principles of each field stem from physical organic chemistry pursuits. The insights, terminology, and lessons, as well as the experimental and computational techniques of physical organic chemistry currently permeate nearly all fields of organic chemistry. Thus, although the number of individuals that call themselves physical organic chemists is dwindling, we should recognize this as the inevitable outcome, revealing the strength of the discipline—it is so powerful that all areas of organic chemistry have adopted it, and therefore, we are all physical organic chemists at heart. This manuscript sets forth to highlight this conclusion by showing how several recent studies in fields not historically recognized as physical organic can be described as being so. The message is upbeat; organic chemists have a common background and language that emanates from physical organic chemistry, irrespective of the titles we each associate ourselves with.
Effects of storage medium and UV photofunctionalization on time‐related changes of titanium surface characteristics and biocompatibility
Authors: Shen Jian‐Wei , Chen Yun , Yang Guo‐Li , Wang Xiao‐Xiang , He Fu‐Ming , Wang Hui‐Ming 
Published: May 2015

AbstractStorage in aqueous solution and ultraviolet (UV) photofunctionalization are two applicable methods to overcome the biological aging and increase the bioactivity of titanium. As information regarding the combined effects of storage medium and UV photofunctionalization has never been found in published literatures, this study focused on whether appropriate storage methods and UV photofunctionalization have synergistic effects on the biological properties of aged titanium surfaces. Titanium plates and discs were sandblasted and acid etched and then further prepared in five different modes as using different storage mediums (air or dH2O) for 4 weeks and then with or without UV treatment. The surface characteristics were evaluated with scanning electron microscopy, contact angle measurements, and X‐ray photoelectron spectroscopy. MC3T3‐E1 cells were cultured on the surfaces, and cellular morphology, proliferation, alkaline phosphatase activity, and osteocalcin release were evaluated. The results showed that nanostructures were observed on water‐stored titanium surfaces with a size of about 15 × 20 nm2. UV treatment was effective to remove the hydrocarbon contamination on titanium surfaces stored in either air or water. UV photofunctionalization further enhanced the already increased bioactivity of modSLA on initial cell attachment, proliferation, alkaline phosphatase activity, and osteocalcin release. Overall, UV photofunctionalization was effective in further enhancing the already increased bioactivity by using dH2O as storage medium, and the effect of UV treatment was much more overwhelming than that of the storage medium. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 932–940, 2016.
Effect of PEO coating on bubble behavior within a polycarbonate microchannel array: A model for hemodialysis
Authors: Coblyn Matthew , Truszkowska Agnieszka , Mohammadi Mahshid , Heintz Keely , McGuire Joseph , Sharp Kendra , Jovanovic Goran 
Published: May 2015

AbstractObstruction of fluid flow by stationary bubbles in a microchannel hemodialyzer decreases filtration performance and increases damage to blood cells through flow maldistribution. A polyethylene oxide (PEO)–polybutadiene (PB)–polyethylene oxide surface modification, previously shown to reduce protein fouling and water/air contact angle in polycarbonate microchannel hemodialyzers, can improve microchannel wettability and may reduce bubble stagnation by lessening the resistive forces that compete with fluid flow. In this study, the effect of the PEO–PB–PEO coating on bubble retention in a microchannel array was investigated. Polycarbonate microchannel surfaces were coated with PEO–PB–PEO triblock polymer via radiolytic grafting. Channel obstruction was measured for coated and uncoated microchannels after injecting a short stream of air bubbles into the device under average nominal water velocities of 0.9 to 7.2 cm/s in the channels. The presence of the PEO coating reduced obstruction of microchannels by stationary bubbles within the range of 1.8 to 3.6 cm/s, average nominal velocity. Numerical simulations based on the lattice Boltzmann method indicate that beneficial effects may be due to the maintenance of a lubricating, thin liquid film around the bubble. The determined effective range of the PEO coating for bubble management serves as an important design constraint. These findings serve to validate the multiutility of the PEO–PB–PEO coating (bubble lubrication, biocompatibility, and therapeutic loading). © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 941–948, 2016.