bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrical percolation behavior of carbon fiber and carbon nanotube polymer composite foams: Experimental and computational investigations
Authors: Behbahani Alireza Foroozani , Motlagh Ghodratollah Hashemi , Ziaee Morteza , Nikravan Goolia 
Published: July 2015

ABSTRACTThe effect of foaming on the electrical percolation of polymer composites was simulated by a random sequential additional (RSA) process. Polystyrene composites containing various amounts of carbon fiber (CF) and carbon nanotubes (CNTs) were prepared through melt blending in an internal mixer and subsequently compression‐molded to solid and foam sheets. The electrical conductivity (EC) and percolation threshold (Pc) of both the solid and foam composites were determined to evaluate the simulation results. The experimental results show that the EC of the CF composites decreased with foaming, whereas for the CNT composites, no significant change was observed. The RSA process was used to construct the microstructure of the solid and foam composites and predict their Pcs. Several parameters, including the fiber aspect ratio, bubble volume fraction, and bubble size, were studied by the simulation approach. The Pcs obtained by simulation showed good agreement with the experimental values. When bubbles were excluded to define the volume fraction of the filler, the foam composites with bubbles, close to the fibers in size, had approximately the same Pcs as the solid composites. Better agreement between the experimental and simulation results was found for the foam composites with 30 vol % bubbles rather than those with 15 vol %. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42685.
Silver nanoparticle incorporated poly(l‐lactide‐co‐glycolide) nanofibers: Evaluation of their biocompatibility and antibacterial properties
Authors: Góra Aleksander , Prabhakaran Molamma P. , Eunice Goh Tze Leng , Lakshminarayanan Rajamani , Ramakrishna Seeram 
Published: July 2015

ABSTRACTThe objective of this work is the fabrication of poly(l‐lactide‐co‐glycolide) or PLGA (with LA/GA ratios of 50/50 and 75/25) nanofibers containing silver nanoparticles (AgNPs) by the method of electrospinning. The incorporation of AgNPs in PLGA was carried out in three different concentrations (1, 3, 6 w/w %).The electrospun nanofibers were evaluated for their morphology by scanning electron microscopy and their fiber diameters ranged between 487 and 781 nm. Integration of AgNPs within the fibers was verified by spectroscopy studies, while the mechanical properties of the developed fibers were found comparable to the mechanical properties of the human skin. Proliferation of human dermal fibroblasts (HDF) demonstrated minimal cytotoxicity on fibers containing 1 wt % and 3 wt % of AgNPs, while 6 wt % of AgNPs inhibited cell proliferation. Antimicrobial activity was studied using three different strains of Gram‐positive and Gram‐negative bacteria. Results of the HDF proliferation and antimicrobial studies showed that the electrospun PLGA75/25 containing 3 wt % AgNP can function as a suitable substrate for wound dressing, compared to the other scaffolds of this study. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42686.
Enhanced poly(γ‐glutamic acid) production by H2O2‐induced reactive oxygen species in the fermentation of Bacillus subtilis NX‐2
Authors: Tang Bao , Zhang Dan , Li Sha , Xu Zongqi , Feng Xiaohai , Xu Hong 
Published: July 2015

AbstractEffects of reactive oxygen species (ROS) on cell growth and poly(γ‐glutamic acid) (γ‐PGA) synthesis were studied by adding hydrogen peroxide to a medium of Bacillus subtilis NX‐2. After optimizing the addition concentration and time of H2O2, a maximum concentration of 33.9 g/L γ‐PGA was obtained by adding 100 µM H2O2 to the medium after 24 H. This concentration was 20.6% higher than that of the control. The addition of diphenyleneiodonium chloride (ROS inhibitor) can interdict the effect of H2O2‐induced ROS. Transcriptional levels of the cofactors and relevant genes were also determined under ROS stress to illustrate the possible metabolic mechanism contributing to the improve γ‐PGA production. The transcriptional levels of genes belonging to the tricarboxylic acid cycle and electron transfer chain system were significantly increased by ROS, which decreased the NADH/NAD+ ratio and increased the ATP levels, thereby providing more reducing power and energy for γ‐PGA biosynthesis. The enhanced γ‐PGA synthetic genes also directly promoted the formation of γ‐PGA. This study was the first to use the ROS control strategy for γ‐PGA fermentation and provided valuable information on the possible mechanism by which ROS regulated γ‐PGA biosynthesis in B. subtilis NX‐2.
Kinetics and Reactor Modeling of the Steam Reforming of Methanol over a Mn‐Promoted Cu/Al Catalyst
Authors: Shi Huancong , Ibrahim Hussameldin , Elamin Mohanned M. , Idem Raphael , Tontiwachwuthikul Paitoon 
Published: July 2015

AbstractThe kinetics of the steam reforming of methanol (SRM) was studied in a packed‐bed reactor over a Mn‐promoted Cu/Al2O3 catalyst under defined conditions. A Langmuir‐Hinshelwood‐Hogan‐Watson (LHHW)‐type mechanism that assumes the dissociative adsorption of methanol on two distinct active sites as the rate‐controlling step was found to satisfactorily describe the SRM reaction with activation energies of 77.3 and 64.5 kJ mol−1 at low and high temperature, respectively. No mass or heat transfer limitations were observed under the experimental conditions used in this study. A reactor model was also developed, validated, and employed to predict the conversion, temperature, and concentration profiles. The axial dispersion had no influence on the temperature distribution but the effect was more pronounced on the methanol conversion.
Roughened Zn‐Doped Ru–Ti Oxide Water Oxidation Electrocatalysts by Blending Active and Activated Passive Components
Authors: Kishor Koshal , Saha Sulay , Gupta Manish Kumar , Bajpai Anshumaan , Chatterjee Moitrayee , Sivakumar Sri , Pala Raj Ganesh S. 
Published: July 2015

AbstractAn approach to decreasing the overpotential, increasing the stability, and optimizing the noble‐metal composition of electrocatalysts for the oxygen evolution reaction (OER) in acidic media is demonstrated. Essential components of this approach are: 1) combining an active (unstable Ru) component with a dopant (Zn)‐activated passive (stable Ti) element, 2) blending these elements by co‐electrodeposition in an acidic environment in which dissolution of the unstable component (excess Ru) promotes roughness, and 3) further increasing the roughness of the resultant electrode through chemical inhomogeneity by the incorporation of Ti and through structural inhomogeneity by incorporation of Zn in RuO2. The composition of the electrode with the maximal activity is Ru0.258Ti0.736Zn0.006Ox, and its activity is four times higher than that of RuO2. The electrochemical stability towards the OER follows the order RuTiZn>RuTi>RuZn>Ru. This design strategy provides a facile method to improve activity without compromising stability.
Development and Validation of an Analytical Model for Predicting Chronoamperometric Responses of Random Arrays of Micro‐ and Nanodisk Electrodes
Authors: Sliusarenko Oleksii , Oleinick Alexander , Svir Irina , Amatore Christian 
Published: July 2015

AbstractQuantitative theoretical investigations based on a 3D Brownian motion approach established that our previous “cylindrical” approximation remains valid even for drastically irregular arrays. This result led us to propose a simple analytical equation that can be used to predict the chronoamperometric behavior of such commonly used irregular arrays, taking into account the statistical distributions of the Voronoi cells built around the disk electrodes.
Graphenes as Efficient Metal‐Free Fenton Catalysts
Authors: Espinosa Juan C. , Navalón Sergio , Primo Ana , Moral Mónica , Sanz Javier Fernández , Álvaro Mercedes , García Hermenegildo 
Published: July 2015

AbstractReduced graphene oxide exhibits high activity as Fenton catalyst with HO. radical generation efficiency over 82 % and turnover numbers of 4540 and 15023 for phenol degradation and H2O2 consumption, respectively. These values compare favorably with those achieved with transition metals, showing the potential of carbocatalysts for the Fenton reaction.
Efficient Self‐Assembly of Di‐, Tri‐, Tetra‐, and Hexavalent Hosts with Predefined Geometries for the Investigation of Multivalency
Authors: Linder Igor , Leisering Stefan , Puttreddy Rakesh , Rades Nadine , Rissanen Kari , Schalley Christoph A. 
Published: July 2015

AbstractCoordination‐driven self‐assembly of differently shaped di‐ to hexavalent crown‐ether host molecules is described. A series of [21]crown‐7‐ and [24]crown‐8‐substituted bipyridine and terpyridine ligands was synthetized in a “toolbox” approach. Subsequent coordination to 3d transition metal and ruthenium(II) ions provides an easy and fast access to host assemblies with variable valency and pre‐defined orientations of the crown‐ether moieties. Preliminary isothermal calorimetry (ITC) titrations provided promising results, which indicated the host complexes under study to be suitable for the future investigation of multivalent and cooperative binding. The hosts described herein will also be suitable for the construction of various multiply threaded mechanically interlocked molecules.
Morphology‐Tunable Fluorescent Nanoparticles: Synthesis, Photophysical Properties and Two‐Photon Cell Imaging
Authors: Hu Xiaoming , Yin Chao , Hu Wenbo , Yang Zhen , Li Jie , Li Xiang , Lu Xiaomei , Zhao Hui , Tang Yufu , Fan Quli , Huang Wei 
Published: July 2015

AbstractA novel water‐soluble fluorescent amphiphile based on amino polyethylene glycol (PEG‐NH2) substituted oligo(p‐phenyleneethynylene) (OPE) was designed and synthesized successfully. Taking anion OPE amphiphile as a comparison, the photophysical features were investigated through ultraviolet absorption (UV) and photoluminescence (PL) analyses. Due to the hydrophobic‐hydrophilic property of the OPE conjugated molecule, self‐assembled nanoparticles with the size ranging from 19.6 to 93.5 nm along with the change of morphology from "grain" to "strawberry" were conveniently prepared via adjusting concentrations of OPE aqueous solution. Interestingly, after aging for a period of time, homogeneous hollow nanospheres were spontaneously constructed with a diameter of about 200 nm. Cytotoxicity test and cellular uptake behavior of the nanoparticles were further investigated to evaluate their potential biomedical applications. Subsequently, the promising applications of two‐photon cell imaging were explored using human pancreatic cancer cells (PANC‐1 cells), which indicated that the nanoparticles were mainly located within the cell cytoplasm.
Toward Eco‐friendly Green Organic Semiconductors: Recent Advances in Spiro[fluorene‐9,9′‐xanthene] (SFX)‐Based Optoelectronic Materials and Devices
Authors: Sun Mingli , Xu Ruochen , Xie Linghai , Wei Ying , Huang Wei 
Published: July 2015

AbstractGreen organic semiconductors (GOS) have the four‐element features, including biomass as stuffs, synthesis with the pot, atom and step economic (PASE) route, eco‐friendly fabrication processes in aqueous phase, and recyclable devices, capturing the trend of organic electronics in the future. Herein, we reviewed the efforts that have been made on GOS by our group. We first made a brief introduction of organic (opto)electronics, followed by the design strategies of GOSs based on spirofluorenes. Concretely, we described the discovery of one‐pot protocol to spirofluorenres and a pot‐atom‐step economic (PASE) platform of spiro[fluorene‐9,9′‐xanthene] (SFX) for the molecular design of organic semiconductors, as well as a state‐of‐the‐art nanocrystalline films with eco‐friendly procedures. Then, we highlighted the progress on SFX‐based organic semiconductors in the organic light‐emitting diode (OLED) field. Finally, we conducted a summary on SFXs in OLED and an outlook on green semiconductors starting from biomass, via one‐pot to spirofluorenes, to water‐phase devices.
Photocatalysis using a Wide Range of the Visible Light Spectrum: Hydrogen Evolution from Doped AgGaS2
Authors: Yamato Kohei , Iwase Akihide , Kudo Akihiko 
Published: July 2015

AbstractDoping of nickel into AgGaS2 yields a new absorption band, at a wavelength longer than the intrinsic absorption band of the AgGaS2 host. The doped nickel forms an electron donor level in a forbidden band of AgGaS2. The nickel‐doped AgGaS2 with rhodium co‐catalyst shows photocatalytic activity for sacrificial H2 evolution under the light of up to 760 nm due to the transition from the electron donor level consisting of Ni2+ to the conduction band of AgGaS2. Apparent quantum yields for the sacrificial H2 evolution at 540–620 nm are about 1 %. Moreover, the nickel‐doped AgGa0.75In0.25S2 also responds to near‐IR light, up to 900 nm.
Spore sensitivity to sunlight and freezing can restrict dispersal in wood‐decay fungi
Authors: Norros Veera , Karhu Elina , Nordén Jenni , Vähätalo Anssi V. , Ovaskainen Otso 
Published: July 2015

AbstractAssessment of the costs and benefits of dispersal is central to understanding species' life‐history strategies as well as explaining and predicting spatial population dynamics in the changing world. While mortality during active movement has received much attention, few have studied the costs of passive movement such as the airborne transport of fungal spores. Here, we examine the potential of extreme environmental conditions to cause dispersal mortality in wood‐decay fungi. These fungi play a key role as decomposers and habitat creators in forest ecosystems and the populations of many species have declined due to habitat loss and fragmentation. We measured the effect of simulated solar radiation (including ultraviolet A and B) and freezing at −25°C on the spore germinability of 17 species. Both treatments but especially sunlight markedly reduced spore germinability in most species, and species with thin‐walled spores were particularly light sensitive. Extrapolating the species' laboratory responses to natural irradiance conditions, we predict that sunlight is a relevant source of dispersal mortality at least at larger spatial scales. In addition, we found a positive effect of spore size on spore germinability, suggesting a trade‐off between dispersal distance and establishment. We conclude that freezing and particularly sunlight can be important sources of dispersal mortality in wood‐decay fungi which can make it difficult for some species to colonize isolated habitat patches and habitat edges.
Impedimetric Aptasensor Based on Disposable Graphite Electrodes Developed for Thrombin Detection
Authors: Eksin Ece , Erdem Arzum , Kuruc Ayben Pınar , Kayi Hilal , Öğünç Aylin 
Published: July 2015

AbstractThe impedimetric aptasensor for Thrombin (THR) was developed for the first time herein by measuring changes at the charge‐transfer resistance, Rct upon to proteinaptamer complex formation. After covalent activation of pencil graphite electrode (PGE) surface using covalent agents, amino linked aptamer (APT) was immobilized onto activated PGE surface. Then APT‐THR interaction was explored by electrochemical impedance spectroscopy (EIS). After the optimization of experimental conditions (e.g., APT and THR concentration, immobilization and interaction times), the selectivity of impedimetric aptasensor was tested in the presence of other biomolecules: factor Va and bovine serum albumine (BSA) both in buffer media, or in diluted fetal bovine serum (FBS).
Methyl‐CpG‐Binding Protein (MBD) Family: Epigenomic Read‐Outs Functions and Roles in Tumorigenesis and Psychiatric Diseases
Authors: Gigek Carolina Oliveira , Chen Elizabeth Suchi , Smith Marilia Arruda Cardoso 
Published: July 2015

ABSTRACTEpigenetics is the study of the heritable changes on gene expression that are responsible for the regulation of development and that have an impact on several diseases. However, it is of equal importance to understand how epigenetic machinery works. DNA methylation is the most studied epigenetic mark and is generally associated with the regulation of gene expression through the repression of promoter activity and by affecting genome stability. Therefore, the ability of the cell to interpret correct methylation marks and/or the correct interpretation of methylation plays a role in many diseases. The major family of proteins that bind methylated DNA is the methyl‐CpG binding domain proteins, or the MBDs. Here, we discuss the structure that makes these proteins a family, the main functions and interactions of all protein family members and their role in human disease such as psychiatric disorders and cancer. J. Cell. Biochem. 117: 29–38, 2016. © 2015 Wiley Periodicals, Inc.
Surface‐engineered Saccharomyces cerevisiae cells displaying redesigned CadR for enhancement of adsorption of cadmium (II)
Authors: Tao Hu‐Chun , Li Peng‐Song , Liu Qi‐Song , Su Jie , Qiu Guo‐Yu , Li Zi‐Gang 
Published: July 2015

AbstractBACKGROUNDThe use of cell‐surface display technology to express recombinant proteins on a microbial cell surface can enhance metal adsorption to microbial cells. The transcription factor CadR of Pseudomonas putida shows highly selective affinity with Cd2+.RESULTSCadR was genetically engineered by truncating 47 N‐terminal amino acids and 21 C‐terminal amino acids in order to maximize its expression efficiency while maintaining its metal‐binding domain. The redesigned CadR (named T68CadR) was then displayed with Saccharomyces cerevisiae a‐agglutinin cell‐surface display system. This engineering approach enhanced the H+/OH− buffering capacity and the Cd2+ adsorption capacity of yeast cells. The surface‐engineered cells also performed well at mesophilic and higher temperatures (30–50 °C) under neutral or alkalescent conditions. With an initial concentration of 1.0 mg L−1, the Cd2+ removal efficiency remained 85% when the concentration of Na+ changed from 0 to 400 mmol L−1 (pH 7.8). The surface‐engineered cells also showed highly selective adsorption to Cd2+ in the presence of Zn2+ and Pb2+.CONCLUSIONST68CadR displayed yeast cells constructed in this study provide an option to selectively remove Cd in water. It also might be promising as a tool to determine CadR's Cd‐binding mechanism and to improve its selectivity and affinity to Cd2+. © 2015 Society of Chemical Industry
Combination of column adsorption and supercritical fluid extraction for recovery of dissolved essential oil from distillation waste water of Yulania liliiflora
Authors: Lei Gaoming , Mao Peizhi , He Minqing , Wang Longhu , Liu Xuesong , Zhang Anyun 
Published: July 2015

AbstractBACKGROUNDAromatic waste water is the main by‐product of industrial essential oil distillation. To recover the dissolved essential oil from this distillation waste water, an approach combining column adsorption (CA) and supercritical fluid extraction (SFE) was proposed. Yulania liliiflora was selected as a case study. Activated carbon of mixed porosity was employed and quantitative desorption of the adsorbed oil was achieved using supercritical carbon dioxide (SC–CO2).RESULTSThe optimized condition of CA‐SFE was 18 MPa, 308 K, dynamic extraction for 60 min and CO2 flow rate of 3.6 g min−1. A recovery of 0.668 ± 0.050 g kg−1 (n = 3) was achieved for the dissolved oil from distillation waste water, significantly higher (P < 0.05) than that obtained by liquid–liquid extraction (LLE) (0.405 ± 0.032 g kg−1, n = 3). Yulania liliiflora recovered oil was rich in eucalyptol (52.6–55.2%), α‐terpineol (15.2–18.1%) and terpinen‐4‐ol (8.1–8.7%).CONCLUSIONThe CA‐SFE approach is highly efficient and especially suitable for large‐scale application. The recovered essential oil is valued for being rich in organoleptically important and biologically active compounds. © 2015 Society of Chemical Industry
Effect of spinach aqueous extract on wound healing in experimental model diabetic rats with streptozotocin
Authors: Rahati Sara , Eshraghian Mohammadreza , Ebrahimi Abdolali , Pishva Hamideh 
Published: July 2015

AbstractBACKGROUNDChronic ulcer is still a serious issue for diabetic patients. Diabetes is a prevalent cause of ulcer regeneration delay and (or) disruption. SinceSpinacia oleraceaextract contains compounds with anti‐oxidative and anti‐inflammatory effects, this may be effective in accelerating the healing process of ulcers, especially diabetic ulcers. Hence, this study examined the effect ofSpinacia oleraceaaqueous extract on ulcer regeneration in an experimental animal model.RESULTSMacroscopic examination of the wounds of the control group and spinach aqueous extract group between 7 and 21 days compared with diabetic group, significant changes were observed (P< 0.05). On microscopic examination, epithelial tissue formation, formation of granulation tissue and new blood vessels in the spinach aqueous extract group and non‐diabetic group compared to the diabetic group showed significant improvements (P< 0.05). Also, significant differences in vascular endothelial growth factor were observed between groups on days 3 and 7 (P< 0.05).CONCLUSIONTheSpinacia oleraceaaqueous extract can be effective in regenerating diabetic ulcers. It affects the speed and structure of the ulcer. © 2015 Society of Chemical Industry
Urolithins, gut microbiota‐derived metabolites of ellagitannins, inhibit LPS‐induced inflammation in RAW 264.7 murine macrophages
Authors: Piwowarski Jakub P. , Kiss Anna K. , Granica Sebastian , Moeslinger Thomas 
Published: July 2015

ScopeEllagitannin‐rich food products and medicinal plant materials were shown to have beneficial effects toward intestinal inflammation. Due to the questionable bioavailability of ellagitannins their gut microbiota metabolites‐urolithins have come to be regarded as potential factors responsible for biological activities observed in vivo. The aim of the study was to determine the influence of the three most abundant bioavailable ellagitannin gut microbiota metabolites‐urolithins A, B, and C on inflammatory responses in RAW 264.7 murine macrophages, which are involved in the pathogenesis of intestine inflammation.Methods and resultsUrolithins A, B, and C decreased NO production via inhibition of the iNOS protein and mRNA expression. They decreased the expression of IL‐1β, TNF‐α, and IL‐6 mRNA in LPS challenged RAW 264.7 murine macrophages. A clear inhibition of NF‐κB p65 nuclear translocation and p50 DNA‐binding activity was associated with the observed anti‐inflammatory activities of urolithins. Among the tested compounds urolithin A had the strongest anti‐inflammatory activity.ConclusionThe anti‐inflammatory effects of urolithins at concentrations that are physiologically relevant for gut tissues (≥40 μM), as revealed in this study, support the data from in vivo studies showing the beneficial effects of ellagitannin‐rich products toward intestinal inflammation.