bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermal, mechanical, and water vapor barrier behavior of polypropylene composite containing modified kaolinite
Authors: Albach Breidi , Munaro Marilda , Santos Pedro H. , Zawadzki Sônia F. , Schreiner Wido H. , Rampon Daniel S. , Barbosa Ronilson V. 
Published: September 2017

ABSTRACTPolypropylene composites containing modified kaolinite were prepared using melt processing and the morphological, thermal, mechanical and their water barrier properties were analyzed. To improve compatibility with polypropylene, kaolinite was modified with silane as a coupling agent. Characterization techniques (X‐ray diffraction, Fourier transform infrared spectroscopy, and X‐ray photoelectron spectroscopy) confirmed the effective grafting of these compounds on the surface and edges of the kaolinite with no functionalization on the inner surface. The differential scanning calorimetry and X‐ray diffraction techniques demonstrated that the addition of grafted kaolinite affected the iPP crystallinity. The thermogravimetric analysis helped to determine the thermal stability of the composites, being this, dependent on the amount of kaolinite and silane. The stress–strain tests demonstrated an increase in Young's modulus and obtained a 70% reduction in water vapor permeation. These improvements were mainly related to the increased compatibility between the iPP/Kaol interfaces promoted by the silane. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45785.
Influence of body composition on disposition of the highly fat distributed compound as analysed by physiologically based pharmacokinetic (PBPK) modeling and simulation
Authors: Goto Akihiko , Tagawa Yoshihiko , Moriya Yuu , Sato Sho , Yamamoto Masami , Wakabayashi Takeshi , Tsukamoto Tetsuya , DeJongh Joost , van Steeg Tamara J. , Moriwaki Toshiya , Asahi Satoru 
Published: September 2017

AbstractA recent study suggested that the pharmacokinetics (PK) of highly fat distributed compounds can be affected by acute changes in the volume of adipose tissue. The present study investigates possible influences of body composition on the disposition of the highly lipophilic compound TAK‐357 in two rat strains. Physiologically based PK (PBPK) modeling and simulation was applied on single and multiple dose PK data of TAK‐357 in obese Wistar fatty rats and Wistar lean rats having approximately 45% and 13% body fat, respectively. The observed effects of an elevated fat mass in Wistar fatty rats on the plasma concentrations appeared to be partly compensated for by other differences between the two rat strains. A decrease in the tissue to blood partition coefficients under high body fat conditions was identified as another factor contributing to the difference in PK. A higher lipid content in the plasma in high body fat animals may result in relatively lower tissue to blood partition coefficients. PBPK‐based simulations indicate that the plasma concentrations of lipophilic compounds in high body fat conditions can differ by up to two‐times at steady‐state. This confirms that there is only a small impact of body composition change on the plasma concentration of highly lipophilic drugs and that the need for therapeutic dose adjustments may be limited.
Antimicrobial activity of lysozyme isoforms: Key molecular features
Authors: Derde Melanie , Vié Véronique , Walrant Astrid , Sagan Sandrine , Lechevalier Valérie , Guérin‐Dubiard Catherine , Pezennec Stéphane , Cochet Marie‐Françoise , Paboeuf Gilles , Pasco Maryvonne , Baron Florence , Gautier Michel , Jan Sophie , Nau Françoise 
Published: September 2017

AbstractIncreasing bacterial resistance towards antibiotics has stimulated research for novel antimicrobials. Proteins acting on bacterial membranes could be a solution. Lysozyme has been proven active against E. coli by disruption of both outer and cytoplasmic membranes, with dry‐heating increasing lysozyme activity. Dry‐heated lysozyme (DH‐L) is a mixture of isoforms (isoaspartyl, native‐like and succinimide lysozymes), giving rise to two questions: what effects does each form have, and which physicochemical properties are critical as regards the antibacterial activity? These issues were investigated by fractionating DH‐L, analyzing structural properties of each fraction, and testing each fraction in vivo on bacteria and in vitro on membrane models. Positive net charge, hydrophobicity and molecular flexibility of the isoforms seem key parameters for their interaction with E. coli membranes. The succinimide lysozyme fraction, the most positive, flexible and hydrophobic, shows the highest antimicrobial activity, induces the strongest bacterial membrane disruption and is the most surface active on model lipid monolayers. Moreover, each fraction appears less efficient than DH‐L against E. coli, indicating a synergetic cooperation between lysozyme isoforms. The bacterial membrane modifications induced by one isoform could facilitate the subsequent action of the other isoforms.
Factors associated with motor complications in Parkinson's disease
Authors: Kadastik‐Eerme Liis , Taba Nele , Asser Toomas , Taba Pille 
Published: September 2017

AbstractObjectivesLevodopa is the most effective therapy for treating Parkinson's disease (PD); however, side effects such as dyskinesias and motor fluctuations may occur after some years of its usage. The aims of this study were to assess the frequency of and factors associated with motor complications among PD patients on levodopa treatment.MethodsIn a cross‐sectional study carried out in 2010–2013, clinical data and treatment details were collected. Logistic regression expressed by odd ratios (OR) and 95% confidence intervals (CI) was conducted to examine the effects of several independent variables on the occurrence of motor complications.ResultsA total of 455 patients were enrolled, among whom 374 were on levodopa. Analysis was performed in 328 patients whose exact duration of levodopa treatment was known. Among patients included in the analysis, 25.9% experienced motor complications; of these, 21% had dyskinesias and 20.1% had motor fluctuations. Based on logistic regression, statistically significant factors associated with the occurrence of motor complications were younger age at onset of the disease, higher levodopa equivalent daily dose (LEDD), shorter time to levodopa initiation, and akinetic‐rigid dominant phenotype of PD.ConclusionsThis study suggests that postponing the start of levodopa therapy and maintaining low daily doses of levodopa might reduce the risk of motor complications. Our results confirm that due to higher risk of motor complications, effectively treating patients with akinetic‐rigid dominant phenotype of PD might be more challenging than for patients whose dominant symptom is tremor.
Involvement of RPL11 in the enhancement of P53 stability by a podophyllum derivative, a topoisomerase II inhibitor
Authors: Wang Huai , Feng Jiang , Zhou Tong , Wei Lijun , Zhou Jianming 
Published: September 2017

AbstractIn previous work, we presented experimental and theoretical evidence that D‐3F or 4‐N‐(2‐Amino‐3‐fluoropyridine)‐4‐deoxidation‐4′‐demethylepipofophyllotoxin induced G2/M phase arrest and apoptosis, purportedly by increasing the expression of P53. However, the precise mechanism of D‐3F action is currently unknown. Here, we investigated the mechanism by which D‐3F treatment induces increased expression of P53. This study showed that D‐3F definitively inhibited the activity of topoisomerase II in a dose‐dependent manner and resulted in DNA damage. The results were in overall agreement with modeling and docking studies performed on D‐3F. In addition, D‐3F increased the levels of P53 and P21 in HeLa cells in a dose‐dependent manner, this in turn prolonged the half‐life of P53. Taken together, these data suggested that D‐3F‐mediated transient enhancement of P53 stabilization may be critical for the P53/P21 signalling pathway leading to G2/M phase arrest on HeLa cells. Furthermore, D‐3F downregulated the phosphorylation of E3 ubiquitin‐protein ligase murine double minute 2 (Mdm2) at Ser166, inhibited Mdm2‐mediated ubiquitination of P53, and released 60S ribosomal protein L11 (RPL11) from the nucleolus into the nucleoplasm. To conclude, the topoisomerase II inhibitor D‐3F causes P53 to accumulate in HeLa cell lines by enhancing its stability as a result of DNA‐damage induced RPL11 relocalization and subsequent blocking of the P53‐Mdm2 feedback loop.
Cervical cancer stem‐like cells: systematic review and identification of reference genes for gene expression
Authors: de Campos Rafael P. , Schultz Iago C. , de Andrade Mello Paola , Davies Samuel , Gasparin Manuela S. , Bertoni Ana P. S. , Buffon Andréia , Wink Márcia R. 
Published: September 2017

AbstractCervical cancer is the fourth most common cancer affecting women worldwide. Among many factors, the presence of cancer stem cells, a subpopulation of cells inside the tumor, has been associated with a worse prognosis. Considering the importance of gene expression studies to understand the biology of cervical cancer stem cells (CCSC), this work identifies stable reference genes for cervical cancer cell lines SiHa, HeLa, and ME180 as well as their respective cancer stem‐like cells. A literature review was performed to identify validated reference genes currently used to normalize RT‐qPCR data in cervical cancer cell lines. Then, cell lines were cultured in regular monolayer or in a condition that favors tumor sphere formation. RT‐qPCR was performed using five reference genes: ACTB, B2M, GAPDH, HPRT1, and TBP. Stability was assessed to validate the selected genes as suitable reference genes. The evaluation validated B2M, GAPDH, HPRT1, and TBP in these experimental conditions. Among them, GAPDH and TBP presented the lowest variability according to the analysis by Normfinder, Bestkeeper, and ΔCq methods, being therefore the most adequate genes to normalize the combination of all samples. These results suggest that B2M, GAPDH, HPRT1, and TBP are suitable reference genes to normalize RT‐qPCR data of established cervical cancer cell lines SiHa, HeLa, and ME180 as well as their derived cancer stem‐like cells. Indeed, GAPDH and TBP seem to be the most convenient choices for studying gene expression in these cells in monolayers or spheres.
A new one‐step procedure for pulmonary valve implantation of the melody valve: Simultaneous prestenting and valve implantation
Authors: Boudjemline Younes 
Published: September 2017

AbstractObjectivesTo describe a new modification, the one‐step procedure, that allows interventionists to pre‐stent and implant a Melody valve simultaneously.BackgroundPercutaneous pulmonary valve implantation (PPVI) is the standard of care for managing patients with dysfunctional right ventricular outflow tract, and the approach is standardized.MethodsPatients undergoing PPVI using the one‐step procedure were identified in our database. Procedural data and radiation exposure were compared to those in a matched group of patients who underwent PPVI using the conventional two‐step procedure.ResultsBetween January 2016 and January 2017, PPVI was performed in 27 patients (median age/range, 19.1/10–55 years) using the one‐step procedure involving manual crimping of one to three bare metal stents over the Melody valve. The stent and Melody valve were delivered successfully using the Ensemble delivery system. No complications occurred. All patients had excellent hemodynamic results (median/range post‐PPVI right ventricular to pulmonary artery gradient, 9/0–20 mmHg). Valve function was excellent. Median procedural and fluoroscopic times were 56 and 10.2 min, respectively, which significantly differed from those of the two‐step procedure group. Similarly, the dose area product (DAP), and radiation time were statistically lower in the one‐step group than in the two‐step group (P < 0.001 for all variables). After a median follow‐up of 8 months (range, 3–14.7), no patient underwent reintervention, and no device dysfunction was observed.ConclusionsThe one‐step procedure is a safe modification that allows interventionists to prestent and implants the Melody valve simultaneously. It significantly reduces procedural and fluoroscopic times, and radiation exposure.
Uveal myxoid leiomyosarcoma in a horse
Authors: Grosås Siv , Østevik Liv , Revold Tobias , Ottesen Nina , Ropstad Ernst‐Otto 
Published: September 2017

Key Clinical MessageA uveal leiomyosarcoma of a horse is reported. There are few published reports of intraocular tumors in horses. Intraocular tumors challenge animal welfare by causing uveitis, glaucoma, and loss of vision. Knowledge regarding treatment of intraocular tumors with globe preservation is sparse, and further investigations on this topic are required.
Photocatalytic CO2 Reduction under Continuous Flow High‐Purity Conditions: Influence of Light Intensity and H2O Concentration
Authors: Dilla Martin , Mateblowski Alina , Ristig Simon , Strunk Jennifer 
Published: September 2017

AbstractThe present study deals with fundamental investigations on the effect of light energy and intensity on the photocatalytic reduction of CO2 on TiO2 P25 under high purity continuous flow conditions. In accordance with previous works, gas chromatographic (GC) online detection identified CH4 as the main product of photocatalytic CO2 reduction. It was found that the product formation is dependent on the light intensity, which verifies that CH4 is formed in a photon induced process on TiO2. A variation of the light intensity revealed that charge carrier recombination is more strongly enhanced compared to the charge transfer reaction to adsorbed species. On these grounds, the rate of CH4 formation increases only by the square root of the light intensity. Furthermore, product formation is predominantly a UV photon driven process. A further part of this study investigated the effect of H2O on the CH4 formation. The photocatalytic removal of carbon‐containing species and the CO2 reduction can already proceed with traces of adsorbed H2O, whereas a continuous flow of gaseous H2O results in an inhibition of product formation. Based on our study, we can identify highly promising routes for photocatalyst improvement.
Characterization of Carbenes via Hydrogenation Energies, Stability, and Reactivity: What's in a Name?
Authors: Vasiliu Monica , Peterson Kirk A. , Arduengo Anthony J. , Dixon David A. 
Published: September 2017

AbstractThe hydrogenation energies and singlet–triplet (S–T) splittings at the G3MP2 level of theory have been calculated for a wide range of carbenes. The carbene, :CXY with different substituents (X, Y=H, CN, NC, F, Cl, OH, OCH3, CH3, CF3, SiH3, SiMe3, phenyl, CH=O, PH2, and NH2) at the carbenic carbon center, immidazole‐based carbenes, Bertrand's carbenes, and Seppelt's CF3CSF3 were studied. The stable carbenes are singlets with large S–T splittings and with the least exothermic hydrogenation energies. The singlet ground state immidazole‐based carbenes are calculated to have the least exothermic hydrogenation energies (−15 to −30 kcal mol−1) and the largest S–T gaps. The singlet ground states of the Bertrand carbenes have more exothermic hydrogenation (ca. −67 kcal mol−1) energies and much smaller S–T gaps. The more exothermic reaction energies arise due to the need to make the phosphorus planar in the carbene so that it can donate into the empty p‐orbital at the carbene carbon center. The bending potential at the carbene carbon center in the Bertrand compounds is very flat with a large XC:Y angle. Seppelt's CF3CSF3 appears to be energetically similar to the Bertrand system, probably due to the required adjustments for geometric distortions at the sulfur center.
Difluoroacetic Acid as a New Reagent for Direct C−H Difluoromethylation of Heteroaromatic Compounds
Authors: Tung Truong Thanh , Christensen Søren Brøgger , Nielsen John 
Published: September 2017

AbstractA technically simple procedure for direct C−H difluoromethylation of heteroaromatic compounds using off‐the‐shelf difluoroacetic acid as the difluoromethylating reagent has been developed. Mono‐difluoromethylation versus bis‐difluoromethylation is controlled as the result of the reaction temperature. The reactions described here enable access to the late‐stage C−H mono‐ and bis‐difluoromethylation for preparation of tool compounds for chemical biology and provide access to this hitherto untapped substituent for drug discovery.
Systematic Design of a Butadiene Telomerization Process: The Catalyst Makes the Difference
Authors: Recker Sebastian , Gordon Charles M. , Peace Amy , Redepenning Christian , Marquardt Wolfgang 
Published: September 2017

AbstractA conceptual design study for a butadiene telomerization process is presented. The impact of catalyst selection on the process economics is included into the design study by an optimization‐based approach relying on shortcut models. In comparison to the established process, investment cost of the novel designed process increase only marginally, while operating costs decrease by more than 75 %. Preliminary pilot‐plant experiments indicate, however, that the economically favorable reaction concept is not stable. Consequently, alternative immobilization strategies are briefly investigated to guide future research.
Characterization of four petrologic end members from Alberta oil sands and comparison between different mines and sampling times
Authors: Geramian Mirjavad , Ivey Douglas G. , Liu Qi , Etsell Thomas H. 
Published: September 2017

The current research was performed on four petrologic end members samples from Syncrude's North Mine collected in 2012 (NM12), i.e. marine clay (MC), marine sand (MS), estuarine clay (EC), and estuarine sand (ES). The mineralogical compositions of the four petrological end members were determined using X‐ray diffraction (XRD), quantitative XRD (QXRD), elemental analysis, and particle size distribution (PSD) measurements.Bulk samples from the four petrologic end members, after bitumen removal, were mainly composed of clay minerals (kaolinite, illite, chlorite, and mixed‐layer expandable clays) and non‐clay minerals such as quartz, carbonates, feldspars, and traces of TiO2 minerals, gypsum, and pyrite. Bulk samples of the clay end members were composed of significantly higher amounts of clay minerals and lower amounts of quartz compared with the bulk samples of the sand end members. XRD analysis of oriented preparations (air dried‐54 % RH and ethylene glycolated) of the < 0.2 μm fractions of the four end members showed that interstratified illite‐smectite of high (∼30 %) and low (∼10 %) expandability were observed only in clay‐rich end members, i.e. NM12‐EC and MC, respectively. Kaolinite‐smectite was only found in the < 0.2 μm fraction of the NM12‐MC with an expandability between 5 and 10 %. Interstratification of illite‐smectite was observed in the < 0.2 μm fraction of NM09‐MC and EC samples but the expandability was only 10 % for both fractions. However, kaolinite‐smectite was not found in the same fraction for NM09‐MC and EC. ES and EC had the highest and lowest bitumen contents, respectively, for the NM12, NM09, and AM10 samples.
Insight into the Interactions of Amyloid β‐Sheets with Graphene Flakes: Scrutinizing the Role of Aromatic Residues in Amyloids that Interact with Graphene
Authors: Božinovski Dragana M. , Petrović Predrag V. , Belić Milivoj R. , Zarić Snežana D. 
Published: September 2017

AbstractThe interaction of amyloid β‐sheet segments with graphene‐flake models is investigated by using DFT calculations. The structure of β‐sheets of selected amyloid segments is based on crystal structures obtained from the Protein Data Bank. Our study, based on DFT calculations for model systems, indicates that the interaction in amyloid–graphene aggregates can be stronger than the interaction in the respective amyloid–amyloid aggregates. The results also indicate an important specific role of aromatic sidechains in amyloid–graphene interactions. This work confirms recent experimental evidence that graphene and its modifications inhibit the aggregation of β‐amyloid peptides.
Iridium Clusters Encapsulated in Carbon Nanospheres as Nanocatalysts for Methylation of (Bio)Alcohols
Authors: Liu Qiang , Xu Guoqiang , Wang Zhendong , Liu Xiaoran , Wang Xicheng , Dong Linlin , Mu Xindong , Liu Huizhou 
Published: September 2017

AbstractC−H methylation is an attractive chemical transformation for C−C bonds construction in organic chemistry, yet efficient methylation of readily available (bio)alcohols in water using methanol as sustainable C1 feedstock is limited. Herein, iridium nanocatalysts encapsulated in yolk–shell‐structured mesoporous carbon nanospheres (Ir@YSMCNs) were synthesized for this transformation. Monodispersed Ir clusters (ca. 1.0 nm) were encapsulated in situ and spatially isolated within YSMCNs by a silica‐assisted sol–gel emulsion strategy. A selection of (bio)alcohols (19 examples) was selectively methylated in aqueous phase with good‐to‐high yields over the developed Ir@YSMCNs. The improved catalytic efficiencies in terms of activity and selectivity together with the good stability and recyclability were contributable to the ultrasmall Ir clusters with oxidation chemical state as a consequence of the confinement effect of YSMCNs with interconnected nanostructures.
Light‐Driven Hydrogen Evolution by Nickel‐Substituted Rubredoxin
Authors: Stevenson Michael J. , Marguet Sean C. , Schneider Camille R. , Shafaat Hannah S. 
Published: September 2017

AbstractAn enzymatic system for light‐driven hydrogen generation has been developed through covalent attachment of a ruthenium chromophore to nickel‐substituted rubredoxin (NiRd). The photoinduced activity of the hybrid enzyme is significantly greater than that of a two‐component system and is strongly dependent on the position of the ruthenium phototrigger relative to the active site, indicating a role for intramolecular electron transfer in catalysis. Steady‐state and time‐resolved emission spectra reveal a pathway for rapid, direct quenching of the ruthenium excited state by nickel, but low overall turnover numbers suggest initial electron transfer is not the rate‐limiting step. This approach is ideally suited for detailed mechanistic investigations of catalysis by NiRd and other molecular systems, with implications for generation of solar fuels.