bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation on static and dynamic performance of a hinge configuration with integrated dielectric elastomers
Authors: Zhang Chi , Chen Hualing , Li Bo , Wang Yanjie , Liu Lei , Li Dichen 
Published: November 2014

ABSTRACTA rigid hinge frame combined with pre‐stretched dielectric elastomer (DE) films can form an active biological agonist–antagonist configuration. In this structure, the DE films undergo a constant deformation under a static voltage as well as specific reciprocating rotation under an alternative voltage. To theoretically investigate the static and dynamic performance, we establish the kinetic equation of the active hinge configuration. The computational static rotary angle exhibits a good fit with the experimental data from literature. Based on this model, static performance of this configuration when DE undergoes uniaxial and pure shear deformation is investigated. Subject to a small perturbation, the configuration may oscillate around the equilibrium state and the natural frequency can be obtained. By varying the pre‐stretch ratios, applied voltage, layer number, and the rotational inertia of the hinge, we can tune the natural frequency at a wide range. When the voltage is sinusoidal and varies continuously, the configuration resonates at multiple frequencies of excitation, known as harmonic and superharmonic resonance. Our research may serve as a guide to optimal design and provide insights into the performance of the hinge configuration, which can effectively expand the structure's application fields. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41630.
Natural rubber/leather waste composite foam: A new eco‐friendly material and recycling approach
Authors: Garcia Nelissa Gonçalves , dos Reis Elton Aparecido Prado , Budemberg Eduardo Roque , Agostini Deuber Lincon da Silva , Salmazo Leandra Oliveira , Cabrera Flávio Camargo , Job Aldo Eloizo 
Published: November 2014

ABSTRACTThis article describes a new approach of recycling the leather waste (shavings) using it as filler in natural rubber foams composites. The foams were prepared using different amounts of leather waste (0–60 parts per hundred of rubber) and submitted to morphological (SEM microscopy) and mechanical analyses (cyclic stress–strain compression). The increase of leather shavings on the composite causes an increase of viscosity in the mixture, which reflects in the foaming process. This results in smaller and fairly uniform cells. Furthermore, expanded rubber has the biggest cell size, with more than 70% of cell with 1000 µm, while the composite with the higher concentration of leather has around 80% of total number of cells with 100–400 µm. The mechanical parameters were found to depend on the leather dust concentration. Moreover, the stiffness rises with the increase of leather shavings; consequently, the compression force for expanded rubber was 0.126 MPa as well as the composite with higher concentration of leather was 7.55 MPa. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41636.
Synthesis and application of nonionic polyacrylamide with controlled molecular weight for fracturing in low permeability oil reservoirs
Authors: Zhao Guang , Dai Caili , Wang Siyu , Zhao Mingwei 
Published: November 2014

ABSTRACTNonionic polyacrylamide (NPAM) with controlled molecular weight was successfully synthesized as a gel fracturing fluid by aqueous solution polymerization. The effects of the monomer concentration, initiator concentration, reaction time, feeding temperature and reaction temperature on the molecular weight were systematically investigated through single‐factor and orthogonal experiments. The NPAM molecular weight can be controlled by adjusting these factors. The decisive factor is the acrylamide concentration, whereas the initiator concentration and feeding temperature are secondary factors. These synthetic NPAMs can be crosslinked with zirconium acetate to produce a gel fracturing fluid for use in low permeability oil reservoirs. Gel fracturing fluids based on synthetic NPAMs have high shear resistance, low filtration performance, easy gel breaking performance, good proppant carrying capability and low core damage capability. By adjusting the NPAM or crosslinker concentrations, the gel fracturing fluid can be adapted for use in low permeability oil reservoirs for a wide temperature range (60–120°C). © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41637.
A new cation‐modified Al‐polyacrylamide flocculant for solid–liquid separation in waste drilling fluid
Authors: Zhang Yongming , Miao Zongcheng , Zou Jing 
Published: November 2014

ABSTRACTA new cation‐modified Al‐polyacrylamide (CAPAM) flocculant was prepared by the in situ polymerization of acrylamide (AM) and (2‐methacryloyloxyethyl) trimethyl ammonium chloride (DMC) with Al(OH)3 sol. The optimum preparation conditions were obtained by a one‐factor experimental design: as the amount of AlCl3 was fixed at 0.025 mol, the polymerization time, polymerization temperature, n(AM) : n(AlCl3), n(DMC) : n(AlCl3), and n(K2S2O8) : n(AM) were 4 h, 70°C, 8, 0.9, and 1.82 × 10−3, respectively. The CAPAM was characterized by thermogravimetric analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy. The solid–liquid separation performance of the CAPAM was evaluated in terms of water content. The CAPAM showed better flocculation performance than cationic polyacrylamide and polyaluminum sulfate at a fixed concentration of 0.3% in waste drilling fluid and tended to perform well in alkaline solution. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41641.
Sulphurous additives for polystyrene: Influencing decomposition behavior in the condensed phase
Authors: Braun Ulrike , Eisentraut Paul , Fuchs Sabine , Deglmann Peter 
Published: November 2014

ABSTRACTThe thermal decomposition behaviour of polystyrene (PS) containing sulphur and phosphorus additives was investigated, using thermogravimetry coupled with Fourier transform infrared spectroscopy (TGA‐FTIR). It was found that the additives influence the decomposition process of the polymer in the condensed phase, resulting in a decrease in styrene monomer formation and an increase in styrene oligmer derivatives. Via reference measurements with binary mixtures it was found that the presence of sulphur additives influences the radicalic decomposition process of PS. In combination with quantum chemical calculations it was concluded that this is due to the formation of radicals that abstract hydrogen from the polymer matrix at lower temperatures, disfavouring the radicalic decomposition pathway leading to styrene. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2015,132, 41665.
Effect of the composition of methanol−water mixtures on tacticity of poly(N‐ethylacrylamide) gel
Authors: Biswas Chandra Sekhar , Sulu Elvan , Hazer Baki 
Published: November 2014

ABSTRACTTwo series of macroporous poly(N‐ethylacrylamide) (PNEAM) gels are synthesized in different composition of methanol–water mixtures (xm = 0, 0.06, 0.13, 0.21, 0.31, and 0.43; where xm = mole fraction of methanol) in presence as well as in the absence of 0.1M Y(OTf)3 Lewis acid as additive. The gels synthesized in the absence of Lewis acid are atactic and in the presence of the same are isotactic. Synthesis of the corresponding linear PNEAM homopolymers shows that, the isotacticity (meso dyad, %) of the resulted polymers increases for the gels prepared in the presence of Lewis acid (LA) and remains constant for the gel prepared in the absence of LA, respectively, with the increase in the concentration of the synthesis solvent methanol. SEM micrographs reveal that, the hydrogels synthesized in the presence of LA are more porous than the gels prepared in the absence of LA. Swelling ratio of all the hydrogels decreases with the increase in the temperature and LA gels show higher swelling ratio values than non LA gels (NLA). Deswelling rate of the hydrogels prepared in methanol–water mixture in presence of LA is faster than the hydrogels prepared in absence of LA. Moreover, reswelling rate increases with increase in the isotacticity of the PNEAM segment in the gel. All these results have been explained on the basis of the formation of highly porous hydrogels with higher isotactic PNEAM chain segment in the presence of LA in methanol–water mixtures. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41668.
Concentration effect on aggregation and dissolution behavior of poly(N‐isopropylacrylamide) in water
Authors: Yan Yongbin , Huang Lianghui , Zhang Quan , Zhou Hu 
Published: November 2014

ABSTRACTThe concentration effect on aggregation and dissolution behavior of poly(N‐isopropylacrylamide) (PNIPAM) in water was studied. Three concentration regimes with different phase behavior were identified by differential scanning calorimetry (DSC). Further optical, light‐scattering, and rheological studies indicated that the appearance of different regimes arose from their corresponding solution structures below lower critical solution temperature (LCST): free chains and small clusters in regime I, large clusters in regime II, and a gel‐like network in regime III. Different solution structures below LCST led to different phase‐separated patterns formed above LCST: colloidal particles in regime I, large precipitate in regime II, and the sponge‐like solid in regime III, which was well understood based on the overlapping parameter P. Different phase‐separated patterns therefore resulted in different remixing behavior as observed by DSC. This work suggests that the swelling and collapse behavior of PNIPAM based hydrogels was controlled through the design of their phase‐separated patterns, and therefore provided a way to develop high performance thermo‐sensitive materials. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2015,132, 41669.
Morphological Features of Herbst Corpuscles in the Oropharynx of the Ostrich (Struthio camelus) and Emu (Dromaius novaehollandiae)
Authors: Crole Martina R. , du Plessis Lizette , Soley John T. 
Published: November 2014

ABSTRACTThe distribution of Herbst corpuscles in the oropharynx of the ostrich and emu has recently been documented. However, although the morphology of these mechanoreceptors is well known in neognathous birds, little structural information is available on the Herbst corpuscles of ratites. Tissue sections from those regions of the oropharynx known to possess a high concentration of Herbst corpuscles were sampled from ostrich and emu heads collected after slaughter and prepared for light and transmission electron microscopy. Intra‐oral Herbst corpuscles in the ostrich and emu displayed the same basic components (capsule, outer zone, inner core and axon) described in neognathous birds. However, some important differences were observed, notably, the presence of myofibroblasts in the capsule, sensory cilia in cells of the outer layers, a relatively larger, less organized outer zone and narrower inner core, and variations in the shape of the axon. The previously unreported presence of myofibroblasts in the capsule possibly indicates its ability to contract, thus altering the tension of the capsule, which in turn has implications for the conduction of vibrational stimuli. The sensory cilia in the myofibroblasts of the capsule bordering the outer zone, and in the fibroblasts of the outer zone itself, may play a regulatory role in controlling the contraction of the capsule. Such a function has not previously been reported for Herbst corpuscles in any species of bird. Anat Rec, 298:783–796, 2015. © 2014 Wiley Periodicals, Inc.
Transcription Factor CREB is Involved in CaSR‐mediated Cytoskeleton Gene Expression
Authors: Huang Shuaishuai , Ren Yu , Wang Ping , Li Yanyuan , Wang Xue , Zhuang Haihui , Fang Rong , Wang Yuduo , Liu Ningsheng , Hehir Michael , Zhou Jeff X. 
Published: November 2014

ABSTRACTOur previous studies illustrated that a steady increase of intracellular calcium concentration ([Ca2+]i) was important for maintaining microtubules (MTs) rearrangement in apoptotic cells. However, little is known about the effect of calcium sensing receptor (CaSR)‐mediated increase in [Ca2+]i on cytoskeleton gene expression. We examined the impact of taxol or CaSR agonist/antagonist on the regulation of [Ca2+]i concentration, cytoskeleton arrangement, phosphorylated CREB and cytoskeleton gene expressions in HeLa cells with dominant negative plasmid of CREB (PM). This study demonstrated that Gdcl3 (a specific CaSR agonist) evoked a rapid increase of [Ca2+]i, formed a rigid bundle of MTs which surrounded the nucleus and decreased the cytoskeleton gene expressions in HeLa cells. These effects were rescued by addition of NPS2390 (a specific CaSR antagonist). Moreover, CaSR activity affected cytoskeleton gene expression through transcription factor CREB. Histoscores of pCREB immunoreactivity in tissues of cervical adenocarcinoma, renal clear cell carcinoma, and diffuse large B‐cell lymphoma were markedly increased compared with non malignant tissue. These data demonstrate, for the first time, that CaSR‐mediated increase in [Ca2+]i probably modulate cytoskeleton organization and gene expression via transcription factor CREB. Anat Rec, 298:501–512, 2015. © 2014 Wiley Periodicals, Inc.
Teat Morphology Characterization With 3D Imaging
Authors: Vesterinen Heidi M. , Corfe Ian J. , Sinkkonen Ville , Iivanainen Antti , Jernvall Jukka , Laakkonen Juha 
Published: November 2014

ABSTRACTThe objective of this study was to visualize, in a novel way, the morphological characteristics of bovine teats to gain a better understanding of the detailed teat morphology. We applied silicone casting and 3D digital imaging in order to obtain a more detailed image of the teat structures than that seen in previous studies. Teat samples from 65 dairy cows over 12 months of age were obtained from cows slaughtered at an abattoir. The teats were classified according to the teat condition scoring used in Finland and the lengths of the teat canals were measured. Silicone molds were made from the external teat surface surrounding the teat orifice and from the internal surface of the teat consisting of the papillary duct, Fürstenberg's rosette, and distal part of the teat cistern. The external and internal surface molds of 35 cows were scanned with a 3D laser scanner. The molds and the digital 3D models were used to evaluate internal and external teat surface morphology. A number of measurements were taken from the silicone molds. The 3D models reproduced the morphology of the teats accurately with high repeatability. Breed didn't correlate with the teat classification score. The rosette was found to have significant variation in its size and number of mucosal folds. The internal surface morphology of the rosette did not correlate with the external surface morphology of the teat implying that it is relatively independent of milking parameters that may impact the teat canal and the external surface of the teat. Anat Rec, 298:1359–1366, 2015. © 2014 Wiley Periodicals, Inc.
Carbohydrate‐binding module tribes
Authors: Carvalho Caio C. , Phan Ngoc N. , Chen Yingfei , Reilly Peter J. 
Published: November 2014

ABSTRACTAt present, 69 families of carbohydrate‐binding modules (CBMs) have been isolated by statistically significant differences in the amino acid sequences (primary structures) of their members, with most members of different families showing little if any homology. On the other hand, members of the same family have primary and tertiary (three‐dimensional) structures that can be computationally aligned, suggesting that they are descended from common protein ancestors. Members of the large majority of CBM families are β‐sandwiches. This raises the question of whether members of different families are descended from distant common ancestors, and therefore are members of the same tribe. We have attacked this problem by attempting to computationally superimpose tertiary structure representatives of each of the 53 CBM families that have members with known tertiary structures. When successful, we have aligned locations of secondary structure elements and determined root mean square deviations and percentages of similarity between adjacent amino acid residues in structures from similar families. Further criteria leading to tribal membership are amino acid chain lengths and bound ligands. These considerations have led us to assign 27 families to nine tribes. Eight of the tribes have members with β‐sandwich structures, while the ninth is composed of structures with β‐trefoils. © 2014 Wiley Periodicals, Inc. Biopolymers 103: 203–214, 2015.
The response of DNA length and twist to changes in ionic strength
Authors: Manning Gerald S. 
Published: November 2014

ABSTRACTWe examine twist‐stretch coupling of unconstrained DNA using polyelectrolyte theory as applied to a line‐charge model along with published data on the ionic‐strength dependence of the twist angle. We conclude that twist‐stretch coupling is negative: environmental changes that stretch free DNA, unconstrained by externally applied pulling or twisting forces, are accompanied by unwinding of the double helix. We also analyze a helical model and conclude that the observed unwinding of the DNA helix when ionic strength is decreased is driven by radial swelling of the helix. © 2014 Wiley Periodicals, Inc. Biopolymers 103: 223–226, 2015.
Influence of a cis,syn‐cyclobutane pyrimidine dimer damage on DNA conformation studied by molecular dynamics simulations
Authors: Knips Alexander , Zacharias Martin 
Published: November 2014

ABSTRACTThe photo‐induced formation of cis‐syn‐cyclobutane pyrimidine dimers (CPD) is a highly mutagenic and cancerogenic DNA lesion. In bacteria photolyases can efficiently reverse the dimer formation employing a light‐driven reaction after looping out the CPD damaged bases into the enzyme active site. The exact mechanism how the repair enzyme identifies a damaged site within a large surplus of undamaged DNA is not fully understood. The CPD damage may alter the DNA structure and dynamics already in the absence of the repair enzyme which can facilitate the initial binding of a photolyase repair enzyme. To characterize the effect of a CPD damage, extensive comparative molecular dynamics (MD) simulations on duplex DNA with central regular or CPD damaged nucleotides were performed supplemented with simulations of the DNA‐photolyase complex. Although no spontaneous flipping out transitions of the damaged bases were observed, the simulations showed significant differences in the conformational states of regular and CPD damage DNA. The isolated damaged DNA adopted transient conformations which resembled the global shape of the repair enzyme bound conformation more closely compared to regular B‐DNA. In particular, these conformational changes were observed in most of helical and structural parameters where the protein bound DNA differs drastically from regular B‐DNA. It is likely that the transient overlap of isolated DNA with the enzyme bound DNA conformation plays a decisive role for the specific and rapid initial recognition by the repair enzyme prior to the looping out process of the damaged DNA. © 2014 Wiley Periodicals, Inc. Biopolymers 103: 215–222, 2015.
Effective radiation doses associated with non‐invasive versus invasive assessment of coronary anatomy and physiology
Authors: Toth G.G. , Ntalianis A. , Ntarladimas Y. , de Booij M. , De Winter O. , Barbato E. , Pilet B. , Van Mieghem C. , Wijns W. , De Bruyne B. 
Published: November 2014

ObjectivesTo compare the effective radiation dose (ERD) needed to obtain information on coronary anatomy and physiology by a non‐invasive versus an invasive diagnostic strategy.BackgroundKnowledge of anatomy and physiology is needed for management of patients with coronary artery disease (CAD). There is, however, a growing concern about detrimental long‐term effects of radiation associated with diagnostic procedures.MethodsIn a total of 671 patients with suspected CAD, we compared the ERD needed to obtain anatomical and physiological information through a non‐invasive strategy or an invasive strategy. The non‐invasive strategy consisted of coronary computed tomography angiography (CCTA) and single photon emission computed tomography (SPECT). The invasive strategy included coronary angiography (CA) and fractional flow reserve (FFR) measurement. In 464 patients, the data were acquired in Period 2009 and in 207 the data were acquired in Period 2011 (after each period, the CCTA‐ and the CA‐equipment had been upgraded).ResultsFor the Period 2009 total ERD of the non‐invasive approach was significantly larger compared to the invasive approach (28.45 ± 5.37 mSv versus 15.79 ± 7.95 mSv, respectively; P < 0.0001). For Period 2011, despite the significant decrease in ERD for both groups (P < 0.0001 for both), the ERD remained higher for the non‐invasive approach compared to the invasive approach (16.67 ± 10.45 mSv vs. 10.36 ± 5.87 mSv, respectively; P < 0.0001). Simulation of various diagnostic scenarios showed cumulative radiation dose is the lowest when a first positive test is followed by an invasive strategy.ConclusionTo obtain anatomic and physiologic information in patients with suspected CAD, the combination of CA and FFR is associated with lower ERD than the combination of CCTA and SPECT. © 2014 Wiley Periodicals, Inc.
Potential risk factors of re‐intervention after endovascular repair for type B aortic dissections
Authors: Zhang Lei , Zhou Jian , Lu Qingsheng , Zhao Zhiqing , Bao Junmin , Jing Zaiping 
Published: November 2014

ObjectivesTo assess the potential risk factors of re‐intervention after thoracic endovascular aortic repair (TEVAR).BackgroundTEVAR has been chosen as a less invasive alternative for Type B aortic dissections (TBADs); however, the potential risk factors of re‐intervention remain unclear. Methods: A total of 252 TBADs patients initially treated with TEVAR between September 1998 and July 2012 were retrospectively reviewed. The indications for the initial TEVAR were 32 aorta enlargement (24 chronic), 71 malperfusion, 46 rupture (32 chronic), 67 refractory pain (54 chronic), and 44 refractory hypertension (38 chronic). The patients were stratified into single‐intervention group and multi‐intervention group.ResultsThe mean age was 54.1 years with 81.7% of male. We found the time from symptom onset to TEVAR was longer in multi‐intervention group (17 vs. 112.5 days, P = 0.006). Higher proportions of chronic dissection and smoking occurred in multi‐intervention group (53.9% vs. 79.2% and 43.9% vs. 70.8%, P = 0.018 and 0.012, respectively). The differences of oversizing, operation time, contrast medium dose, and blood loss between the groups were significant (13.8 ± 2.4% vs. 16.4 ± 2.9%, 92.5 vs. 196 minutes, 110 vs. 210 ml, 100 vs. 300 ml; P < 0.001, <0.001, =0.002, and =0.003, respectively). The mortality within 30 days was 2.4% and the rates of stoke, paraplegia and retrograde dissection were 3.6%, 5.6% and 0.8%, respectively. The most common reasons of re‐intervention were endoleaks, new dissections and incomplete thrombosis of the false lumen.Conclusionswe concluded that chronic phase, smoking and too big oversizing were potential risk factors of re‐intervention. © 2014 Wiley Periodicals, Inc.