bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measuring effect of the blooming of chemical curatives on the rate of cyclic fatigue crack growth in natural rubber filled with a silanized silica nanofiller
Authors: Saeed Farhan , Ansarifar Ali , Ellis Robert J. , Haile‐Meskel Yared 
Published: October 2011

AbstractTwo rubber compounds with different amounts of chemical curatives were prepared by mixing natural rubber with a high loading of a sulfur‐bearing silanized precipitated amorphous white silica nanofiller. The chemical bonding between the filler and rubber was optimized via the tetrasulfane groups of the silane by adding a sulfenamide accelerator and zinc oxide. The rubber compounds were cured and stored at ambient temperature for 65 days before they were tested. One compound showed extensive blooming as a function of storage time. Thin tensile strips of the rubber vulcanizates containing an edge crack were repeatedly stressed at constant strain amplitude and test frequency at ambient temperature and crack length c was measured as a function of the number of cycles n. The cut growth per cycle, dc/dn, was calculated and plotted against the tearing energy, T. The blooming of the chemical curatives increased dc/dn by up to an order of magnitude at a constant T. This was due to the reagglomeration of the chemical curatives in the rubber and also within a thin layer approximately 15 to 20 μm in size beneath the rubber surface. Under repeated stressing, cracks grew through the relatively weak agglomerated areas in the rubber and this caused the rate of crack growth to increase at a constant T. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Preparation, characterization, and protein loading properties of N‐acyl chitosan nanoparticles
Authors: Cho Youngjin , Kim Jun Tae , Park Hyun Jin 
Published: October 2011

AbstractVarious N‐acyl chitosans with propionyl‐, hexanoyl‐, nonanoyl‐, lauroyl‐, pentadecanoyl‐, and stearoyl‐groups were synthesized and self‐aggregated N‐acyl chitosan nanoparticles (CSNPs) were prepared by sonication. By the modification with N‐acyl groups, CSNPs increased their hydrophobic character and changed its structural features to be more suitable as a delivery carrier. The mean diameters of bovine serum albumin (BSA)‐loaded N‐acyl CSNPs ranged from 138 to 551 nm. Uniform particle size distribution of BSA‐loaded N‐acyl CSNPs was observed. The protein loading efficiency of N‐acyl CSNPs was about 94–95% with lower BSA concentration (0.1 mg/mL) and not significantly different with acyl chain length. With higher BSA concentration (1.0 mg/mL), however, the highest protein loading efficiency was observed with lauroyl and pentadecanoyl CSNPs. The results suggest that lauroyl and pentadecanoyl CSs are interesting candidates for protein delivery system. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Investigation of solid supported dendrimers for water disinfection
Authors: Gangadharan D. , Dhandhala Nirav , Dixit Dhara , Thakur Rajendra Singh , Popat Kiritkumar Mangaldas , Anand P. S. 
Published: October 2011

AbstractPolystyrene copolymer beads supported dendrimer was synthesized and investigated for its biological applications. Macroporous cross‐linked polystyrene copolymer beads were synthesized using suspension polymerization. Two successive generations of di(chloroethyl) amine‐type end group functionality was formed on the polystyrene copolymer beads. Elemental analysis, Fourier transform infrared spectra, and solid state13C NMR spectra were employed to characterize the polymer bound dendrimer. The polymer bound dendrimer was tested for antibacterial action against both Gram‐positive and Gram‐negative bacteria. The activity against both types of organism increased with an increase in the nitrogen atoms in the polymer back bone. The dendritic structure containing both amino and di(chloroethyl) groups showed significant reduction in the bacterial count when kept in 20 mL autoclaved water with bacterial cultures having an initial count in the range of 12–83 × 106CFU/mL. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Mechanical properties and morphology of polypropylene‐calcium carbonate nanocomposites prepared by dynamic packing injection molding
Authors: Gao Xueqin , Deng Cong , Ren Chao , Zhang Jie , Li Zhongming , Shen Kaizhi 
Published: October 2011

AbstractIn this article, dynamic packing injection molding (DPIM) technology was used to prepare injection samples of Polypropylene‐Calcium Carbonate (PP/CaCO3) nanocomposites. Through DPIM, the mechanical properties of PP/nano‐CaCO3 samples were improved significantly. Compared with conventional injection molding (CIM), the enhancement of the tensile strength and impact strength of the samples molded by DPIM was 39 and 144%, respectively. In addition, the tensile strength and impact strength of the PP/nano‐CaCO3 composites molded by DPIM increase by 21 and 514%, respectively compared with those of pure PP through CIM. According to the SEM, WAXD, DSC measurement, it could be found that a much better dispersion of nano‐CaCO3 in samples was achieved by DPIM. Moreover, γcrystal is found in the shear layer of the DPIM samples. The crystallinity of PP matrix in DPIM sample increases by 22.76% compared with that of conventional sample. The improvement of mechanical properties of PP/nano‐CaCO3 composites prepared by DPIM attributes to the even distribution of nano‐CaCO3 particles and the morphology change of PP matrix under the influence of dynamic shear stress. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Preparation of PE nanocomposites using pristine nano clay via alkyl ammonium solution injection in a twin‐screw extruder
Authors: Sarikhani K. , Abdollahi S. , Garmabi H. 
Published: October 2011

AbstractIn this study, saline water was used as a preintercalating agent for pristine clay surface to assist clay dispersion in one‐step melt state process. The solution contains dodecyl trimethyl ammonium chloride salt in distilled water and was injected into the twin‐screw extruder using a high pressure dosing pump. To investigate the effect of dissolution of alkyl salt on clay dispersion, two samples with the same compositions were prepared through both salt solution and pure water injection which was compared with organo‐modified prepared sample. The resultant compounds were characterized using x‐ray diffraction (XRD), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and dynamic rheological measurements (RMS). Tensile and notched‐Izod impact properties of the samples were measured as well. The XRD results showed no peak for the sample containing 2 wt % pristine clay, prepared via injection of salt solution representing exfoliated microstructure. In addition, TEM images showed proper dispersion and distribution of clay platelets in the matrix. Furthermore, RMS results showed that the slop of the storage modulus has been declined and for the sample using saline, the variation was prominent as a result of network structure formation. Tensile results also showed an increase of tensile modulus in the range of about 22% for the sample containing 2 wt % clay. Izod impact strength in the sample prepared via injection of salt solution showed fracture energy comparable to neat polyethylene. Additionally, the crystallization data in terms of degree of crystallinity, melting, and crystallization temperatures of samples represented no noticeable change compared to neat polyethylene. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Modification of cement with succinic anhydride‐based hyperbranched polyesteramide
Authors: Amin Amal , Darweesh Hassan M. , Ramadan Ahmed M. , Morsi Samir M. M. , Ayoub Magdy M. H. 
Published: October 2011

AbstractTwo hyperbranched polyesteramides (HYP1 and HYP2) were prepared by reacting succinic anhydride (ScAn) with both of diisopropanolamine (DiPA) and diethanolamine, respectively, via one‐pot polycondensation reaction. The prepared polymers were analyzed using gel permeation chromatography, infrared spectra, and 1HNMR. The resulting hydroxyl‐ended resins have been successfully applied as polymeric admixtures in two types of cements such as Ordinary Portland cement and Portland limestone cement. The water of consistency decreased by addition of the hyperbranched polymers in both types of cements. Better hydration was observed by incorporation of small amounts of polymers. The infrared spectra and scanning electron microscopy photos of Ordinary Portland cement and Portland limestone cement pastes premixed with HYP1 and HYP2 showed no effect on the chemical composition of the cement hydrates where only the morphology and the crystallinity of the formed hydrates were changed. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
A study on nanofiller effects of serpentine in polypropylene matrix
Authors: Tan Semra , Tinçer Teoman 
Published: October 2011

AbstractThe nanocomposite materials were prepared using serpentine as filler and polypropylene (PP) as the matrix in the presence of maleic anhydride grafted polypropylene (PP‐g‐MA) compatibilizer. The melt intercalation was carried out following serpentine modification with a quaternary salt of cetyl‐trimethyl‐ammonium bromide. The structure of nanocomposites was shown by X‐ray diffraction (XRD) and transmission electron microscopy (TEM) studies. Thermal analysis performed by differential scanning calorimetry (DSC) demonstrated that the nanocomposites have higher percentage crystallinity when compared to neat PP. Dynamic mechanical analysis (DMA) revealed that the storage and loss moduli values of the nanocomposites are better than those of the matrix resin. Tensile properties of nanocomposites are significantly different from PP, e.g., the Young's modulus of the nanocomposite with 2 wt % serpentine and 6 wt % PP‐g‐MA (PP‐2,6Q) was found to be 2065 MPa, i.e., nearly 190.8% increase over the PP matrix. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Comparative Structural Analysis of α‐Glucosidase Inhibitors on Difference Species: A Computational Study
Authors: Narayana Moorthy N. S. Hari , Ramos Maria J. , Fernandes Pedro A. 
Published: October 2011

AbstractStructural feature analysis of chlorogenic acid derivatives made up of varying lengths of alkyl groups as α‐glucosidases inhibitors were performed by QSAR techniques. The statistically significant models derived from the study were validated by leave one out, Y‐randomization and test set methods. The predictive capacity of the models was assessed by its validation parameters such as crossvalidated correlation coefficients (Q2), predictive residual analysis and other correlation parameters. The results obtained from the study show that the models were constructed with vsurf like properties (vsurf_ID4, vsurf_ID7 and vsurf_CW8), partial charge (Q_VSA_FNEG) and conformation dependent charged (dipoleX) descriptors. The integy moments of hydrophobicity descriptors (ID4 and ID7) are contributed for the inhibitory activity of the α‐glucosidases enzymes of both the species. The vsurf_ID7 descriptor has contributed significantly (negatively) for the inhibitory activity prediction of α‐glucosidases enzymes of S. cerevisiae. The partial negative charge on the surface of the molecules is detrimental for the activity, which reveals that the active site of the enzymes may have negatively charged groups. The pharmacophore analysis results also confirm the presence of hydrophilic properties on the vdW surface of the molecules. These results explain that the active sites of α‐glucosidase enzymes of both the species have the same environment for the interaction. The alkyl side chain on the molecules is important for the pharmacokinetic behavior of the molecules and reduces the interaction energy of the molecules with the water. Hence, these results will be useful for designing novel molecules with multiple activities.
Synthesis and Anticholinesterase Activity and Cytotoxicity of Novel Amide Derivatives
Authors: Altintop Mehlika Dilek , Kaplancikli Zafer Asim , Ozdemir Ahmet , Turan‐Zitouni Gülhan , Temel Halide Edip , Akalın Gülşen 
Published: October 2011

AbstractIn the present study, some amide derivatives were synthesized and their potential anticholinesterase properties were investigated. N‐(Benzothiazol‐2‐yl)‐2‐[(5‐amino/methyl‐1,3,4‐thiadiazol‐2‐yl)thio]acetamide derivatives were obtained by nucleophilic substitution of 2‐chloro‐N‐(benzothiazole‐2‐yl)acetamide derivatives with appropriate 1,3,4‐thiadiazole‐2‐thioles. The chemical structures of the compounds were elucidated by 1H‐NMR, 13C‐NMR and FAB+‐MS spectral data and elemental analyses. Each amide derivative was evaluated for its ability to inhibit AChE and BuChE using a modification of Ellman's spectrophotometric method. The compounds were also investigated for their cytotoxic properties using MTT assay. 2‐(5‐Amino‐1,3,4‐thiadiazol‐2‐yl)thio‐N‐(benzothiazol‐2‐yl)acetamide derivatives have anticholinesterase activity, whereas 2‐(5‐methyl‐1,3,4‐thiadiazol‐2‐yl)thio‐N‐(benzothiazol‐2‐yl)acetamide derivatives have no inhibitory effect on enzyme activity. Among these compounds, it is clear that compound IIh is the most potent derivative.
Solutions of the generalized Sylvester matrix equation and the application in eigenstructure assignment
Authors: Yang Chunlei , Liu Jianzhou , Liu Yu 
Published: October 2011

AbstractIn this paper, a numerical solution to the problem of eigenstructure assignment for descriptor systems is investigated. To this end, we obtain numerical solutions of the generalized Sylvester matrix equation AV + BW = EVF using an iterative method. Based on the presented solution of this equation, an approach using a generalized inverse matrix for eigenstructure assignment in continuous descriptor system via descriptor variable feedback u = Kx is proposed. Finally, some numerical results show the effectiveness of the proposed approach.Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
A novel in situ probe for oxygen uptake rate measurement in mammalian cell cultures
Authors: Behr Larissa , Joeris Klaus , Burnett Mark , Scheper Thomas 
Published: October 2011

AbstractThe newly developed in situ oxygen uptake rate (in situ OUR) probe presented in this article is based on the in situ microscope technology platform. It is designed to measure the oxygen uptake rate (OUR) of mammalian cells, an important parameter for metabolic flux analysis, inside a reactor (in situ) and in real‐time. The system isolates a known volume of cell culture from the bulk inside the bioreactor, monitors the oxygen consumption over time, and releases the sample again. The sample is mixed during the measurement with a new agitation system to keep the cells in suspension and prevent oxygen concentration gradients. The OUR measurement system also doubles as a standard dissolved oxygen (DO) probe for process monitoring when it is not performing OUR measurements. It can be equipped with two different types of optical sensors (i.e., DO, pH) simultaneously or a conventional polarographic DO‐probe (Clark type). This new probe was successfully tested in baby hamster kidney perfusion cell cultures. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2012
Multivariate quality control solved by one‐class partial least squares regression: identification of adulterated peanut oils by mid‐infrared spectroscopy
Authors: Xu Lu , Cai Chen‐Bo , Deng De‐Hua 
Published: October 2011

The Partial least squares class model (PLSCM) was recently proposed for multivariate quality control based on a partial least squares (PLS) regression procedure. This paper presents a case study of quality control of peanut oils based on mid‐infrared (MIR) spectroscopy and class models, focusing mainly on the following aspects: (i) to explain the meanings of PLSCM components and make comparisons between PLSCM and soft independent modeling of class analogy (SIMCA); (ii) to correct the estimation of the original PLSCM confidence interval by considering a nonzero intercept term for center estimation; (iii) to investigate the potential of MIR spectroscopy combined with class models for identifying peanut oils with low doping concentrations of other edible oils.It is demonstrated that PLSCM is actually different from the ordinary PLS procedure, but it estimates the class center and class dispersion in the framework of a latent variable projection model. While SIMCA projects the original variables onto a few dimensions explaining most of the data variances, PLSCM components consider simultaneously the explained variances and the compactness of samples belonging to the same class. The analysis results indicate PLSCM is an intuitive and easy‐to‐use tool to tackle one‐class problems and has comparable performance with SIMCA. The advantages of PLSCM might be attributed to the great success and well‐established foundations of PLS. For PLSCM, the optimization of model complexity and estimation of decision region can be performed as in multivariate calibration routines. Copyright © 2011 John Wiley & Sons, Ltd.
Transformation of the {Fe(NO)2}9 Dinitrosyl Iron Complexes (DNICs) into S‐Nitrosothiols (RSNOs) Triggered by Acid–Base Pairs
Authors: Tsou Chih‐Chin , Liaw Wen‐Feng 
Published: October 2011

AbstractS‐Nitrosation of the coordinated thiolate of dinitrosyl iron complexes (DNICs) to generate S‐nitrosothiols (RSNOs) was demonstrated. Transformation of [{(NO)2Fe(μ‐StBu)}2] (1‐tBuS) into the {Fe(NO)2}9 DNIC [(NO)2Fe(StBu)(MeIm)] (2‐MeIm) occurs under addition of 20 equiv of 1‐methylimidazole (MeIm) into a solution of 1‐tBuS in THF. The dynamic interconversion between {Fe(NO)2}9 [(NO)2Fe(S‐NAP)(dmso)] (2‐dmso) (NAP=N‐acetyl‐D‐penicillamine) and [{(NO)2Fe(μ‐S‐NAP)}2] (1‐NAP) was also observed in a solution of complex 1‐NAP in DMSO. In contrast to the reaction of complex 2‐MeIm and bis(dimethylthiocarbamoyl) disulfide ((DTC)2) to yield {Fe(NO)}7 [(NO)Fe(DTC)2] (3) (DTC=S2CNMe2) accompanied by (tBuS)2 and NO(g), transformation of {Fe(NO)2}9 2‐MeIm (2‐dmso) into RSNOs (RS=tBuS, NAP‐S) along with complex 3 induced by the Brønsted acid solution of (DTC)2 demonstrated that Brønsted acid may play a critical role in triggering S‐nitrosation of the coordinated thiolate of DNICs 2‐MeIm (or 2‐dmso) to produce RSNOs. That is, DNIC‐mediated S‐nitrosation requires a Brønsted acid–Lewis base pair to produce RSNO. Transformation of DNICs into RSNOs may only occur on the one‐thiolate‐containing {Fe(NO)2}9 DNICs, in contrast to protonation of the two‐thiolate‐containing DNICs [(NO)2Fe(SR)2]− by Brønsted acid to yield [{(NO)2Fe(μ‐SR)}2]. These results might rationalize that the known protein‐Cys‐SNO sites derived from DNICs were located adjacent to acid and base motifs, and no protein‐bound SNO characterized to date has been directly derived from [protein–(cysteine)2Fe(NO)2] in biology.
Invasion triangle: an organizational framework for species invasion
Authors: Perkins Lora B. , Leger Elizabeth A. , Nowak Robert S. 
Published: October 2011

AbstractSpecies invasion is a complex, multifactor process. To encapsulate this complexity into an intuitively appealing, simple, and straightforward manner, we present an organizational framework in the form of an invasion triangle. The invasion triangle is an adaptation of the disease triangle used by plant pathologists to help envision and evaluate interactions among a host, a pathogen, and an environment. Our modification of this framework for invasive species incorporates the major processes that result in invasion as the three sides of the triangle: (1) attributes of the potential invader; (2) biotic characteristics of a potentially invaded site; and (3) environmental conditions of the site. The invasion triangle also includes the impact of external influences on each side of the triangle, such as climate and land use change. This paper introduces the invasion triangle, discusses how accepted invasion hypotheses are integrated in this framework, describes how the invasion triangle can be used to focus research and management, and provides examples of application. The framework provided by the invasion triangle is easy to use by both researchers and managers and also applicable at any level of data intensity, from expert opinion to highly controlled experiments. The organizational framework provided by the invasion triangle is beneficial for understanding and predicting why species are invasive in specific environments, for identifying knowledge gaps, for facilitating communication, and for directing management in regard to invasive species.
CD8α+ and CD8α− DC subsets from BCG‐infected mice inhibit allergic Th2‐cell responses by enhancing Th1‐cell and Treg‐cell activity respectively
Authors: Gao Xiaoling , Bai Hong , Cheng Jianjun , Fan Yijun , Wang Shuhe , Jiao Lei , Xiu Nan , Yang Xi 
Published: October 2011

AbstractThe hygiene hypothesis has suggested an inhibitory effect of infections on allergic diseases, but the related mechanism remains unclear. We recently reported that DCs played a critical role in Mycobacterium bovis Bacille Calmette–Guérin (BCG)‐mediated inhibition of allergy, which depended on IL‐12 and IL‐10‐related mechanisms. Here, we tested the hypothesis that BCG infection could modulate the function of DC subsets, which might in turn inhibit allergic responses through different mechanisms. We sorted CD8α+ and CD8α− DCs from BCG‐infected mice and tested their ability to modulate Th2‐cell responses to ovalbumin (OVA) using in vitro and in vivo approaches. We found that both DC subsets could inhibit the allergic Th2‐cell response in both a DC:T‐cell co‐culture system and after adoptive transfer. These subsets exhibited different co‐stimulatory marker expression and cytokine production patterns and were different in inducing Th1 and Treg cells. Specifically, we found that CD8α+ DCs produced higher IL‐12, inducing higher Th1 cell response, while CD8α− DCs expressed higher ICOS‐L and produced higher IL‐10, inducing CD4+CD25+FoxP3+Treg cells with IL‐10 production and membrane‐bound TGF‐β expression. The finding suggests that one infection may inhibit allergy by both immune deviation and regulation mechanisms through modulation of DC subsets.
Synthesis of Hydrogen Polyoxides H2O4 and H2O3 and Their Characterization by Raman Spectroscopy
Authors: Levanov Alexander V. , Sakharov Dmitri V. , Dashkova Anna V. , Antipenko Ewald E. , Lunin Valeri V. 
Published: October 2011

AbstractHydrogen tetroxide (H2O4) and hydrogen trioxide (H2O3) have been prepared in relatively large quantities as components of peroxy radical condensates. The polyoxides were characterized by the Raman spectra of the oxygen framework. Lines at 500, 756, and 878 cm–1 correspond to skeletal oscillations of H2O3 in the condensate (OOO bend, asymmetric OO stretch, symmetric OO stretch). Lines at 449, 589, 624, 827, and 865 cm–1 match the skeletal vibrations of H2O4 (OOO bend 1, OOO bend 2, center OO stretch, asymmetric OO stretch, symmetric OO stretch). The line of the O4 torsion vibration of hydrogen tetroxide was not observed experimentally. The assignment was confirmed by B3LYP/6‐31+G(d,p) calculations of the vibrational spectra. According to the information available in the literature, this work is the only report of the preparation of H2O4 in significant concentrations and its Raman spectrum. For the first time convincing evidence is provided for the existence of hydrogen tetroxide (in low‐temperature solids).