bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dispersive liquid–liquid microextraction based on the solidification of deep eutectic solvent for the determination of benzoylureas in environmental water samples
Authors: Zeng Haozhe , Qiao Kexin , Li Xin , Yang Miyi , Zhang Sanbing , Lu Runhua , Li Jing , Gao Haixiang , Zhou Wenfeng 
Published: September 2017

AbstractWe present a novel dispersive liquid–liquid microextraction method based on the solidification of deep eutectic solvent coupled with high‐performance liquid chromatography with a variable‐wavelength detection for the detection of five benzoylureas in real water samples. In this work, a green solvent consisting of 1‐octyl‐3‐methylimidazolium chloride and 1‐dodecanol was used as an extraction solvent, yielding the advantages of material stability, low density, and a suitable freezing point near room temperature. Parameters that significantly affect extraction efficiency were optimized by the one‐factor‐at‐a‐time approach. Under optimal conditions, the recoveries of five target compounds were obtained ranging from 87.39 to 98.05% with correlation coefficients ranging from 0.9994 to 0.9997 for pure water. The limits of detection were in the range of 0.09–0.16 μg/L. The enrichment factors were in the range of 171–188. Linearities were achieved in the range of 0.5–500 μg/L. The proposed method was successfully applied to determine benzoylureas in environmental water samples with a satisfactory recovery of approximately 81.38–97.67%.
Quantifying small‐magnitude soil erosion: Geomorphic change detection at plot scale
Authors: Balaguer‐Puig Matilde , Marqués‐Mateu Ángel , Lerma José Luis , Ibáñez‐Asensio Sara 
Published: September 2017

AbstractSoil erosion is a big concern in bare soils from burnt areas and agricultural lands that lack a vegetation cover. In those unprotected soils, intense rain episodes, typical in Mediterranean climate, cause severe soil erosion processes that have been well studied previously using a number of procedures, such as the geomorphic change detection (GCD) method. This method uses digital elevation models (DEMs) of the soil surface and determines the morphological changes in terms of both erosion and deposition by DEMs of difference (DoDs). However, some types of soil erosion, such as diffuse and sheet erosion, may have a small magnitude, at a millimetre scale, and their determination requires methods adapted to that scale. In this paper, we analyse the suitability of the GCD method to account for small magnitude soil erosion. We present a laboratory procedure and setup to represent and quantify sediment budget in small experimental soil plots through differences of DEMs obtained from images using photogrammetric structure from motion. This study explores several key aspects of the technique: establishment of a common reference system for DEMs; determination of errors in the generation of DEMs; selection of appropriate criteria to obtain reliable changes in DoDs; error propagation using Monte Carlo simulation; and validation of the procedure by comparing the results with actual sediments collected during the experiment. Results showed an overestimation of 13% in accumulated soil loss and confirmed that GCD approach with structure from motion‐based DoDs is a suitable method to quantify small‐magnitude erosion events.
Complex Brush‐Like Macromolecular Architectures via Anionic and Ring Opening Metathesis Polymerization: Synthesis, Characterization, and Thermal Properties
Authors: Theodosopoulos George V. , Bitsi Spyridoula‐Lida , Pitsikalis Marinos 
Published: September 2017

AbstractCombination of anionic and ring opening metathesis (ROMP) polymerizations is conducted for the synthesis of different series of brush polymers adopting the macromonomer methodology. Specifically, poly(tert‐butoxystyrene) (PtBOS), polystyrene (PS), and poly(ethylene oxide) (PEO) macromonomers, having end norbornene groups, are prepared by anionic polymerization techniques and suitable termination reactions or functional anionic initiators. These macromonomers are either homopolymerized or copolymerized by ROMP employing Ruthenium Grubbs catalysts of the 1st or 3rd generation leading to the formation of polymer brushes. Using this synthetic approach, PtBOS polymacromonomers, PtBOS‐PEO block and random copolymacromonomers, and PtBOS‐PS random copolymacromonomers are prepared. Acidic hydrolysis of the tert‐butoxy groups of the PtBOS brushes affords the corresponding polyhydroxystyrene (PSOH) brushes. Subsequent activation of the hydroxyl groups upon reaction with triphenylmethyl potassium and addition of ethylene oxide lead to the formation of PEO brushes on the PSOH brushes (brush on brush structures). These materials are thoroughly characterized by size exclusion chromatography, and 1H‐NMR spectroscopy. The thermal properties are studied by differential scanning calorimetry, thermogravimetric analysis , and differential thermogravimetry.
Cyclic Poly(l‐lactide) via Ring‐Expansion Polymerization by Means of Dibutyltin 4‐Tert‐Butylcatecholate
Authors: Kricheldorf Hans R. , Weidner Steffen M. , Scheliga Felix 
Published: September 2017

AbstractFive new catalysts are prepared from dibutyltin oxide and catechol (HCa), 2,3‐dihydroxynaphthalene (NaCa), 4‐tert‐butyl catechol (BuCa), 4‐cyano catechol (CyCa), and 4‐benzoyl catechol (BzCa), but only BuCa gives useful results. When benzyl alcohol is used as an initiator, linear chains having benzyl ester end groups are formed in a slow polymerization process. In contrast to cyclic or noncyclic dibutyltin bisalkoxides, neat BuCa yields cyclic poly(l‐lactide)s via a fast ring‐expansion polymerization. Under certain conditions, a high‐melting crystalline phase (T
m = 191 °C) is obtained. At 160 °C and short reaction times even‐numbered cycles are slightly prevailing, but, surprisingly, at 120 °C, odd‐numbered cycles are predominantly formed. These results definitely prove that a ring‐expansion mechanism is operating.
Stability of Adsorbed Polystyrene Nanolayers on Silicon Substrates
Authors: Jiang Naisheng , Cheung JustinM. , Guo Yichen , Endoh Maya K. , Koga Tadanori , Yuan Guangcui , Satija Sushil K. 
Published: September 2017

AbstractThe solid–polymer melt interface is of great scientific interest due to its vital importance in governing a wide array of physical and mechanical properties of polymer thin films. Recent studies have elucidated the coexistence of two different chain conformations of polymer chains adsorbed on a solid (i.e., loosely adsorbed chains and flattened chains). In this work, film stabilities of the polystyrene (PS) “interfacial sublayer” (composed of outer loosely adsorbed chains and inner flattened chains) and flattened layer (composed of the lone flattened chains) prepared on silicon (Si) substrates are investigated. The atomic force microscopy studies reveal that the as‐rinsed PS flattened layer is subjected to spinodal‐like dewetting during a post‐thermal annealing process even at temperatures below the bulk glass transition temperature. Furthermore, it is found that the surface morphology of the flattened layer can be reversibly changed from a homogeneous pattern under good solvent conditions to spinodal‐like droplets under poor solvent conditions. By contrast, it is found that the PS interfacial sublayer remains stable under both good and poor solvent conditions. These findings illuminate the role which density variations within the adsorbed layers play in the mechanism behind the wetting‐dewetting transition.
Influence of Anion and Crosslink Density on the Ionic Conductivity of 1,2,3‐Triazolium‐Based Poly(ionic liquid) Polyester Networks
Authors: Nguyen Anh , Rhoades Taylor C. , Johnson R. Daniel , Miller Kevin M. 
Published: September 2017

AbstractCovalently crosslinked, 1,2,3‐triazolium‐containing poly(ionic liquid) networks are prepared using Michael addition polymerization. Crosslink density and counteranion are varied in order to decipher the relationships between poly(ionic liquid) (PIL) structure and their thermal, mechanical, and conductive properties. An increase in acrylate concentration leads to a higher crosslink density, as reflected by an increase in the differential scanning calorimetry Tg, dynamic mechanical analyzer E′, and a decrease in the ionic conductivity. Most notable with variable counteranion PILs is that analysis of the ionic conductivity curves reveals a common “crossover” point at ≈85 °C (same acrylate:acetoacetate ratio). Below this crossover temperature, the ionic conductivity appears to be more dependent upon network/polymer chain dynamics. Above 85 °C, the conductivity correlates best with the size of the counteranion. All of the PILs reported here exhibit good ionic conductivities (10−6 to 10−8 S cm−1@25 °C, 30% RH), supporting the notion that 1,2,3‐triazolium‐containing PILs represent a vastly underrated electroactive material platform.
An eigenvalue approach for the automatic scaling of unknowns in model‐based reconstructions: Application to real‐time phase‐contrast flow MRI
Authors: Tan Zhengguo , Hohage Thorsten , Kalentev Oleksandr , Joseph Arun A. , Wang Xiaoqing , Voit Dirk , Merboldt K. Dietmar , Frahm Jens 
Published: September 2017

AbstractThe purpose of this work is to develop an automatic method for the scaling of unknowns in model‐based nonlinear inverse reconstructions and to evaluate its application to real‐time phase‐contrast (RT‐PC) flow magnetic resonance imaging (MRI). Model‐based MRI reconstructions of parametric maps which describe a physical or physiological function require the solution of a nonlinear inverse problem, because the list of unknowns in the extended MRI signal equation comprises multiple functional parameters and all coil sensitivity profiles. Iterative solutions therefore rely on an appropriate scaling of unknowns to numerically balance partial derivatives and regularization terms. The scaling of unknowns emerges as a self‐adjoint and positive‐definite matrix which is expressible by its maximal eigenvalue and solved by power iterations. The proposed method is applied to RT‐PC flow MRI based on highly undersampled acquisitions. Experimental validations include numerical phantoms providing ground truth and a wide range of human studies in the ascending aorta, carotid arteries, deep veins during muscular exercise and cerebrospinal fluid during deep respiration. For RT‐PC flow MRI, model‐based reconstructions with automatic scaling not only offer velocity maps with high spatiotemporal acuity and much reduced phase noise, but also ensure fast convergence as well as accurate and precise velocities for all conditions tested, i.e. for different velocity ranges, vessel sizes and the simultaneous presence of signals with velocity aliasing. In summary, the proposed automatic scaling of unknowns in model‐based MRI reconstructions yields quantitatively reliable velocities for RT‐PC flow MRI in various experimental scenarios.
New Era in shared cellular networks: Moving into open and virtualized platform
Authors: Narmanlioglu Omer , Zeydan Engin 
Published: September 2017

SummarySoftware‐defined networking (SDN) concept provides many features including hardware abstraction, programmable networking and centralized policy control. This allows benefiting from recently developed open source frameworks to build service platforms from a dynamic softwarized ecosystem of networking. There are two major technologies for building the next generation mobile network: Radio Access Network (RAN) sharing and Cloud RAN (C‐RAN). RAN sharing ensures efficient usage of network equipment among multiple mobile network operators (MNOs) and C‐RAN benefits installation, evolution, management, and performance improvements. One of the main benefits that can be used along with these features is dynamic virtualization of RAN and core/backhaul networks to ensure network sharing among multiple MNOs for efficient usage of their network infrastructures. In this work, we propose an SDN‐based C‐RAN architecture managed by C‐RAN controllers, which are integrated with a virtualization controller that is crucial for core/backhaul network sharing of the proposed next generation cellular network architecture. We further provide a use case study of shared mobile architecture for channel‐aware remote radio head (RRH) assignment to multiple MNOs. Two C‐RAN–aided cooperative algorithms, named ANCESTOR and MORGAN, that ensure load balancing among RRHs and better received signal strength levels are provided. Moreover, by selecting MNO assignments judiciously, MORGAN is shown to converge to a pure strategy Nash Equilibrium with high probability in the shared network architecture. The results reveal the proposed methods' performance advantages over static distribution and convergence properties.
Synthesis and electromagnetic shielding behaviour of poly(o‐toluidine)/red mud composite
Authors: Gairola S.P. , Pande Anu , Gairola Preeti , Sharma Sudesh , Purohit L.P. , Dhawan S.K. 
Published: September 2017

This paper is an attempt to find out application of red mud in controlling electromagnetic pollution. Composite of PoT/RM has been prepared by in‐situ chemical oxidative polymerization and has been tested for electromagnetic shielding effectiveness. Red mud here acted as a filler material. The incorporation of 50 wt% red mud in the polymer matrix results in a shielding effectiveness of 8.9 dB in 8.2 to 12.4 GHz frequency range (X‐band). Furthermore, the structural analysis, morphology, and magnetization have been studied using XRD, TEM, and VSM techniques, respectively. TEM image of the composite shows the distribution of red mud particles in the polymer matrix. The magnetization decreases on incorporation of red mud in the polymer matrix.
Constituting of a new surface‐initiating system on polymeric microspheres and preparation of basic protein surface‐imprinted material in aqueous solution
Authors: Gao Baojiao , Chen Tao , Cui Kunli 
Published: September 2017

In this work, a new surface‐initiating system was constituted on the surfaces of cross‐linked polyvinyl alcohol (CPVA) microspheres, and on this basis, papain surface‐imprinted material was successfully prepared in aqueous solution. CPVA microspheres were modified with chlorethamin as reagent, and so a mass of primary amino group was introduced onto CPVA microspheres. Whereupon, a surface initiating system (−NH2/S2O82−) was formed at the interface between the microspheres and aqueous solution, in which papain as template protein, 4‐styrene sulfonate (SSS) as functional monomer, N,N′‐methylenebisacrylamide (MBA) as cross‐linker and (NH4)2S2O8 as initiator were all dissolved. In neutral solution, the polypeptide chains of papain as a basic protein were positively charged, and the molecules of anionic monomer SSS would spontaneously gather around papain polypeptide chain, forming complex by right of strong electrostatic interaction. The free radicals produced on CPVA microspheres initiated the monomer SSS around papain polypeptide chain and the cross‐linker MBA to produce graft/cross‐linking polymerization, and at the same time, papain macromolecules were embed in the cross‐linked networks. As a result, the graft/cross‐linking polymerizing of SSS and the molecule imprinting of papain were synchronously carried out, and papain surface‐imprinted material, MIP‐PSSS/CPVA microspheres, was obtained. The experimental results show that the papain surface‐imprinted material has excellent binding affinity and high recognition selectivity for papain. The binding capacity of MIP‐PSSS/CPVA microspheres for papain reaches 44 mg/g, and relative to another basic protein, trypsin (TRY) as contrast protein, the selectivity coefficient of MIP‐PSSS/CPVA microspheres for papain is 14.35, displaying very high recognition specificity.
Vitamin D deficiency and outcomes in pediatric hematopoietic stem cell transplantation
Authors: Beebe Kristen , Magee Kyrie , McNulty Annmarie , Stahlecker Jennifer , Salzberg Dana , Miller Holly , Mirea Lucia , Adams Roberta , Ngwube Alexander 
Published: September 2017

AbstractBackgroundPediatric patients undergoing hematopoietic stem cell transplantation (HSCT) are frequently diagnosed with vitamin D deficiency, which may impact outcomes.Objectives: To estimate the prevalence of vitamin D deficiency and examine its association with short‐term survival in pediatric HSCT patients.MethodsPatients undergoing HSCT at Phoenix Children's Hospital were retrospectively identified. Routine serum 25‐hydroxyvitamin D measurements were described prior to transplant and at 100 days and 1‐year post‐HSCT. Associations of pre‐HSCT vitamin D groups (i.e., normal ≥30 ng/ml, insufficient 20–29 ng/ml, and deficient <30 ng/ml) with demographics, clinical factors, and outcomes were examined using nonparametric tests and Cox proportional hazards analyses.Results: Among 72 study subjects, the median vitamin D pre‐HSCT was 26 ng/ml (range: 19–34 ng/ml). Levels were insufficient and deficient in 25 (35%) and 20 (28%) patients, respectively, with only two (3%) patients on supplemental therapy pre‐HSCT. Despite supplemental therapy provided to 46 (74%) subjects, insufficient/deficient rates did not significantly change between pre‐HSCT and 100 days post‐HSCT, but mean vitamin D levels significantly increased by 1‐year post‐HSCT (P = 0.01).Vitamin D pre‐HSCT was not associated with the development of acute or chronic graft‐versus‐host disease (GVHD) or delayed engraftment. Overall 1‐year survival was significantly lower for patients with deficient (65%) compared to normal (93%) pre‐HSCT vitamin D (P = 0.001).ConclusionSuboptimal vitamin D levels are common in pediatric patients scheduled to receive HSCT and are associated with lower overall 1‐year survival. Further study is warranted to delineate the mechanisms underlying the role of vitamin D in successful HSCT.
Resistance mechanism of Fusarium fujikuroi to phenamacril in the field
Authors: Hou Yi‐Ping , Qu Xiang‐Pu , Mao Xue‐Wei , Kuang Jing , Duan Ya‐Bing , Song Xiu‐shi , Wang Jian‐Xin , Chen Chang‐Jun , Zhou Ming‐Guo 
Published: September 2017

AbstractBACKGROUNDRice bakanae disease, mainly caused by Fusarium fujikuroi, is an important disease of rice. Phenamacril has been used to control the disease for a few years in China. In 2016, nine phenamacril‐resistant strains were found in the field in Zhejiang Province. The aim of the study was to clarify the mechanism of resistance of F. fujikuroi to phenamacril and the fitness of resistant strains.RESULTSThe nine F. fujikuroi strains examined were highly resistant to phenamacril. Eight of them had the point mutation TCA (Ser) → CCA (Pro) at codon 219 in the Myosin‐5 protein, while the other had the point mutation TCA (Ser) → TTA (Leu) at codon 219. Myosin‐5 replacement between resistant and sensitive strains confirmed that the point mutation in Myosin‐5 caused the resistance of F. fujikuroi to phenamacril. Docking of phenamacril into the modeled binding pocket of Myosin‐5 showed that the affinity between phenamacril and Myosin‐5 decreased and a hydrogen bond could not be formed between phenamacril and the amino acid at codon 219 after it changed to Pro or Leu. There was no cross‐resistance between phenamacril and other fungicides. The eight resistant strains containing the point mutation S219P had almost the same fitness as the sensitive strains, while the one resistant strain containing the point mutation S219 L showed decreased mycelial growth, sporulation and pathogenicity.CONCLUSIONIn the field, the point mutation S219P or S219 L in Myosin‐5 conferred high resistance to phenamacril in F. fujikuroi. The point mutation S219P did not affect the fitness of F. fujikuroi, while the point mutation S219 L decreased its fitness. © 2017 Society of Chemical Industry
Aqueous Extracts of Wild Mushrooms Show Antimicrobial and Antiadhesion Activities against Bacteria and Fungi
Authors: Klančnik Anja , Megušar Polona , Sterniša Meta , Jeršek Barbara , Bucar Franz , Smole Možina Sonja , Kos Janko , Sabotič Jerica 
Published: September 2017

Mushrooms represent promising sources of novel bioactive compounds and can be applied as innovative strategies to control microbial contamination and infection via the food chain. We characterized aqueous extracts from 21 wild basidiomycete mushrooms and the cultivated oyster mushroom, Pleurotus ostreatus, as putative sources of antimicrobial and antiadhesive compounds. Broth microdilutions and adhesion to a polystyrene surface were evaluated on Gram‐positive and Gram‐negative bacteria and on fungi. The aqueous extracts tested showed antimicrobial and antiadhesive activities against these microorganisms. Biochemical analyses of the P. ostreatus extract indicated the involvement of several compounds with different molecular masses. Copyright © 2017 John Wiley & Sons, Ltd.
Electron affinity of modified benzene
Authors: Driver Nicholas , Jena Purusottam 
Published: September 2017

AbstractThe electron affinities of organic molecules obeying Hückel's rule of aromaticity are vanishingly small, if not negative. For example, benzene, a classic example of an aromatic molecule, has an electron affinity of −1.15 eV. Using density functional theory, we have systematically calculated the electron affinities and vertical detachment energies of C6H6 by substituting H with halogen (F) and superhalogen (BO2) moieties, as well as replacing one of the C atoms with B. The ground state geometries were obtained by examining about 330 isomers. The electron affinities are found to steadily increase with these substitutions/replacements, even surpassing that of Cl, the element with the highest electron affinity in the periodic table, in the case of C5BH(BO2)5. In some special cases such as C6H5(BO2) the electron affinity and vertical detachment energy differ by as much as 5 eV, indicating substantial changes in the geometry as the electron is removed from the anion. We hope that the ability to change the negative electron affinity of C6H6 to large positive values by substituting H and/or replacing C atom will motivate experimental studies.
Aluminum‐poor hexacarbalane structures: The transition from localized organoaluminum structures to delocalized polyhedra
Authors: Attia Amr A. A. , Lupan Alexandru , King Robert Bruce 
Published: September 2017

AbstractThe series of hexacarbalanes C6Aln–6Men (n = 7–11) represent a progression from localized organoaluminum structures to delocalized polyhedral structures en route to experimentally known 13‐ and 14‐vertex hexacarbalanes such as (AlMe)8(CCH2Ph)5(µ4H), (AlMe)8(CCH2Ph)5(CCPh), [R4N+]2[(AlH)8(CR)6], and (AlNMe3)2(AlR)6(CR)6. In this connection, the lowest energy seven‐vertex C6AlMe7 structure has a tetrahapto benzene ring with the four AlC(cage) bonding interactions required to give the aluminum the favored octet configuration. Related eight‐vertex C6Al2Me8 structures are found with a benzene ring bound to an Al2 unit with a short AlAl distance of ∼2.55 Å suggesting a formal double bond. However, the lowest energy C6Al2Me8 structure has a dialuminacyclobutene unit fused to a tricyclohexane unit through an Al2 edge. Other relatively low‐energy C6AlMe7 and C6Al2Me8 structures consist of a six‐carbon hexatriene chain either forming a seven‐membered C6Al ring in the seven‐vertex structure or acting as a “flyover” between an Al2 unit. The lowest energy nine‐vertex hexacarbalane C6Al3Me9 has two separate C3 units bridged by both an Al2 pair and a single aluminum atom. Higher energy C6Al3Me9 hexacarbalanes contain a pentadienyl chain and an isolated carbon atom with an imbedded bonded Al3 triangle. The low‐energy 10‐vertex C6Al4Me10 structures have a central Al4 butterfly with nonbonding distances between the wingtips ranging from 3.35 to 3.91 Å. The lowest energy 11‐vertex C6Al5Me11 structure has a central Al4 quadrilateral with a diagonal bridged by the fifth aluminum atom. Higher energy C6Al5Me11 structures have an edge rather than a diagonal of the central Al4 quadrilateral bridged by the fifth aluminum atom.