bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and characterization of phenolic resol resin blended with silica sol and PVA
Authors: Fang Zucheng , Suo Jinping 
Published: July 2010

AbstractThe phenolic resol resin (PF) has a wide application in industry, but its poor tensile ductility and insufficient mechanical strength have severely limited its application. To overcome these limitations, in this study, the mixtures of silica sol and poly(vinyl acohol) (PVA) were used to modify the PF. The structure, morphology, mechanical properties, and thermal stability of these hybrid materials were investigated by FTIR, SEM, tensile shear test (TSS), and TG. FTIR spectra indicated that the multiple reactive functional silanol group SiOH on the surface of SiO2 particles reacted with PVA and PF. Compared with pure PF, the composite 50‐50‐3% exhibited the maximum shear strength which increased by 158%, whereas the elongation at break increased by 63%. Morphological results agreed well with the mechanical properties. The TG results suggested that the composite material 50‐50‐3% and pure PF had almost the same thermal stability because silica sol and PVA had opposite effects on the heat resistance of the hybrid materials. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Mechanical and morphological properties of polycarbonate and montmorillonite filled epoxy hybrid composites
Authors: Bakar M. , Kostrzewa M. , Okulska‐Bożek M. , Jacewicz E. 
Published: July 2010

AbstractThis work investigates the effect of polycarbonate (PC) and montmorillonite (MMT) content on the properties and morphology of epoxy resin (EP). Izod impact strength (IS), flexural strength and critical stress intensity factor (KC) were estimated as function of modifiers content. The values of IS and KC parameters increased by respectively 150% and 90% with the addition of 5 wt % PC. Hybrid compositions containing 1 wt % MMT and 5 wt % PC exhibited the best mechanical properties. Indeed, the addition of 1 wt % MMT to EP modified with 5 wt % PC caused enhancement of IS values by 100% in comparison with neat EP. SEM micrographs revealed that the enhancement mechanism of mechanical properties might be due to extensive yielding of EP associated with the formation of stratified elongated structures. Moreover, differential scanning calorimetry analysis revealed that the addition of nanoclay to EP resulted in a decrease of the glass transition temperature. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Self‐oscillatory neck propagation in polymers
Authors: Bazhenov Sergey 
Published: July 2010

AbstractThe oscillatory neck propagation during cold drawing of PET was studied. The mechanism of self‐oscillations is heat instability of neck propagation. Oscillations are observed at high velocities when the draw stress increases with an increase in cross‐head speed. Neck propagation is described by three equations, which were solved numerically. The solution of these equations predicts appearance of oscillations at high elongation velocities in agreement with experimental observations. The necessary condition of appearance of oscillations in any polymer is existence of some interval of cross‐head speeds V, where the draw stress decreases with an increase in V. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
On the interpretation of metastable zone width in anti‐solvent crystallization
Authors: Sangwal K. 
Published: July 2010

AbstractConsidering nonlinear dependence of solute concentration on anti‐solvent–solvent composition a modified Nývlt‐like equation based on traditional power‐law relation between nucleation rate and developing supersaturation and a new equation based on the classical theory of three‐dimension nucleation are proposed to explain the dependence of anti‐solvent addition rate on metastable zone width defined as excessive anti‐solvent composition in anti‐solvent crystallization. The experimental data on the metastable zone width in anti‐solvent crystallization of benzoic acid are analyzed and discussed from the standpoint of these equations. It is found that the new approach based on the classical nucleation theory provides better insight into the processes involved in anti‐solvent crystallization. Analysis of the experimental results on anti‐solvent crystallization of benzoic acid [D. O'Grady, M. Barret, E. Casey, and B. Glennon, Trans. IChemE A 85, 945, (2007)] revealed that: (1) the value of metastable zone width for a solvent–anti‐solvent system is determined by the solute–solvent and solute–anti‐solvent interactions, (2) the dependence of the metastable zone width on stirring is associated with the enthalpy of mixing, and (3) the new approach predicts a threshold anti‐solvent addition rate associated with the setting up of an equilibrium between solvent and anti‐solvent and a maximum anti‐solvent addition rate connected with the induction period tind for the onset of crystallization. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Overdense Plasma Operation in the WEGA Stellarator
Authors: Otte M. , Laqua H.P. , Marsen S. , Podoba Y. , Preinhaelter J. , Stange T. , Urban J. , Wagner F. , Zhang D. 
Published: July 2010

AbstractOn WEGA stellarator electron Bernstein waves have been applied for plasma heating. The excitation of the electrostatic Bernstein waves was possible due to an efficient two‐step OXB mode conversion process from electromagnetic waves. Overdense plasma operation was reached in argon and helium and, rather surprisingly, a supra‐thermal electron component could be detected (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Apoptosis of mesenchymal stem cells induced by hydrogen peroxide concerns both endoplasmic reticulum stress and mitochondrial death pathway through regulation of caspases, p38 and JNK
Authors: Wei Hua , Li Zongwei , Hu Shengshou , Chen Xi , Cong Xiangfeng 
Published: July 2010

AbstractPoor survival of mesenchymal stem cells (MSCs) compromised the efficacy of stem cell therapy for myocardial infarction. The increase of exogenous reactive oxygen species (ROS) in infracted heart is one of the important factors that challenged the survival of donor MSCs. In the study we aimed to evaluate the effect of oxidative stress on the cell death of MSCs and investigate its mechanisms in order to help with the identification of new biological compounds to reduce donor cells damage. Apoptosis of MSCs were evaluated with Hoechst 33342 staining and flow cytometry analysis. The mitochondrial membrane potential of MSCs was analyzed with JC‐1 staining. Signaling pathways involved in H2O2 induced apoptosis were analyzed with Western blot. H2O2 induced apoptosis of MSCs in a dose‐ and time‐dependent manner. H2O2 induced apoptosis of MSCs via both endoplasmic reticulum (ER) and mitochondrial pathways rather than extrinsic apoptosis pathway. H2O2 caused transient rather than sustained activation of p38 and JNK with no effect on ERK1/2 pathway. P38 was involved in the regulation of early apoptosis of MSCs while JNK was involved in the late apoptosis. P38 directed both ER stress and mitochondria death pathway in the early apoptosis. In conclusion, exogenous ROS was a major factor to induce apoptosis of MSCs. Both ER stress and mitochondria death pathway were involved in the apoptosis of MSCs. H2O2 activated p38 that directed the above two pathways in the regulation of early apoptosis of MSCs while JNK was involved in the late apoptosis of MSCs. J. Cell. Biochem. 111: 967–978, 2010. © 2010 Wiley‐Liss, Inc.
Protein kinase Cδ and caspase‐3 modulate TRAIL‐induced apoptosis in breast tumor cells
Authors: Yin Shuping , Sethi Seema , Reddy Kaladhar B. 
Published: July 2010

AbstractThis report describes that protein kinase C delta (PKCδ) overexpression prevents TRAIL‐induced apoptosis in breast tumor cells; however, the regulatory mechanism(s) involved in this phenomenon is(are) incompletely understood. In this study, we have shown that TRAIL‐induced apoptosis was significantly inhibited in PKCδ overexpressing MCF‐7 (MCF7/PKCδ) cells. Our data reveal that PKCδ inhibits caspase‐8 activation, a first step in TRAIL‐induced apoptosis, thus preventing TRAIL‐induced apoptosis. Inhibition of PKCδ using rottlerin or PKCδ siRNA reverses the inhibitory effect of PKCδ on caspase‐8 activation leading to TRAIL‐induced apoptosis. To determine if caspase‐3‐induced PKCδ cleavage reverses its inhibition on caspase‐8, we developed stable cell lines that either expresses wild‐type PKCδ (MCF‐7/cas‐3/PKCδ) or caspase‐3 cleavage‐resistant PKCδ mutant (MCF‐7/cas‐3/PKCδ mut) utilizing MCF‐7 cells expressing caspase‐3. Cells that overexpress caspase‐3 cleavage‐resistant PKCδ mutant (MCF‐7/cas‐3/PKCδmut) significantly inhibited TRAIL‐induced apoptosis when compared to wild‐type PKCδ (MCF‐7/cas‐3/PKCδ) expressing cells. In MCF‐7/cas‐3/PKCδmut cells, TRAIL‐induced caspase‐8 activation was blocked leading to inhibition of apoptosis when compared to wild‐type PKCδ (MCF‐7/cas‐3/PKCδ) expressing cells. Together, these results strongly suggest that overexpression of PKCδ inhibits caspase‐8 activation leading to inhibition of TRAIL‐induced apoptosis and its inhibition by rottlerin, siRNA, or cleavage by caspase‐3 sensitizes cells to TRAIL‐induced apoptosis. Clinically, PKCδ overexpressing tumors can be treated with a combination of PKCδ inhibitor(s) and TRAIL as a new treatment strategy. J. Cell. Biochem. 111: 979–987, 2010. © 2010 Wiley‐Liss, Inc.
Distinct intracellular vesicle transport mechanisms are selectively modified by spastin and spastin mutations
Authors: Fuerst Julia C. , Henkel Andreas W. , Stroebel Armin , Welzel Oliver , Groemer Teja W. , Kornhuber Johannes , Bönsch Dominikus 
Published: July 2010

AbstractSpastin is a microtubule severing ATPase that regulates intracellular and axonal transport of vesicles. Intracellular vesicle trafficking was analyzed in differentiated SH‐SY5Y‐neuroblastoma cells, transfected with spastin wild‐type and three spastin mutations (ΔN, K388R, S44L) to investigate spastin‐mediated effects on the velocity of vesicles, stained with LysoTracker Red®. The vesicle velocity varied considerably between mutations and detailed analysis revealed up to five distinct velocity classes. Microtubule severing by overexpressed wild‐type spastin caused reduced vesicle velocity. S44L and ΔN mutations, which were functionally impaired, showed similar velocities as control cells. K388R‐transfected cells exhibited an intermediate velocity profile. The results support the idea that spastin mutations not only alter axonal transport, but in addition regulate intracellular trafficking in the cell soma as well. J. Cell. Physiol. 226: 362–368, 2011. © 2010 Wiley‐Liss, Inc.
Highly Conducting Polypyrrole/Cellulose Nanocomposite Films with Enhanced Mechanical Properties
Authors: Sasso Claudia , Zeno Elisa , Petit‐Conil Michel , Chaussy Didier , Belgacem Mohamed Naceur , Tapin‐Lingua Sandra , Beneventi Davide 
Published: July 2010

AbstractPPy was synthesised by oxidative chemical polymerisation using xylan, CMC and NFC as additives. Conducting nanocomposite films were cast from aqueous slurries using doped PPy particles, CMC and NFC as the conducting and reinforcing phase, respectively. NFC‐based composites had higher conductivity and lower mechanical properties than CMC‐based homologues. SEM analysis showed that in PPy/NFC composites, PPy and NFC were arranged in two entangled networks, whereas, in PPy/NFC composites, CMC formed a continuous matrix around PPy particles, thus limiting conductivity. Mechanical properties of nanocomposite films were interpreted as reflecting the presence of different structures when using NFC or CMC as reinforcing phase.magnified image
Ring‐Opening Metathesis Polymerization‐Based Synthesis of CaCO3 Nanoparticle‐Reinforced Polymeric Monoliths for Tissue Engineering
Authors: Weichelt Franziska , Frerich Bernhard , Lenz Solvig , Tiede Stefanie , Buchmeiser Michael R. 
Published: July 2010

AbstractPorous monolithic materials have been prepared via ring‐opening metathesis polymerization from norborn‐2‐ene and a 7‐oxanorborn‐2‐ene‐based cross‐linker in the presence of porogenic solvents (i.e., 2‐propanol and toluene) and norborn‐2‐enephosphonate surface‐modified CaCO3 nanoparticles, using the 3rd‐generation Grubbs‐initiator RuCl2(Py)2(IMesH2)(CHPh). The experimental setup and the conditions chosen allowed for the manufacturing of polymeric monoliths characterized by a homogeneous distribution of the inorganic nanoparticles throughout the polymeric monolith. Depending on the nanoparticle content, the macropore diameters could be varied in the 30–120 µm regime. Noteworthy, the addition of nanoparticles did not affect the phase separation‐triggered formation of the monolithic matrix nor the meso‐ and microporosity as evidenced by N2‐adsorption experiments.magnified image
Evaluation of the Canadian fire weather index system in an eastern Mediterranean environment
Authors: Dimitrakopoulos A. P. , Bemmerzouk A. M. , Mitsopoulos I. D. 
Published: July 2010

AbstractThe Fire Weather Index module of the Canadian Forest Fire Danger Rating System (CFFDRS) was evaluated during two consecutive fire seasons in the Mediterranean environment of Crete, Greece. The Duff Moisture Code (DMC), the Drought Code (DC), the Buildup Index (BUI) and the Fire Weather Index (FWI) were highly correlated to fire occurrence but only moderately to area burned. Logistic regression was applied in order to classify the FWI values into fire danger classes appropriate for the Mediterranean environments, as follows: 0–38 Low, 39–48 Moderate, 49–59 High, > 60 Extreme. The new classification was necessary because the existing Canadian fire danger classes were found inapt for the dry and extremely fire prone eastern Mediterranean climate of Crete. After the modification, the fluctuation of the FWI values predicted more successfully the days of high fire risk, as proved by the actual fire occurrence. High correlation was found between measured litter (L layer) moisture values and those predicted by the Fine Fuel Moisture Code (FFMC). The use of an equilibrium duff moisture content value lower than 20% in Mediterranean environments, would probably improve the Duff Moisture Code (DMC) predictions. The Drought Code (DC) was poorly correlated to the upper soil moisture content. Overall, the FWI demonstrated several aptitudes related to its potential use as a meteorological fire danger rating index in Mediterranean regions. However, long–term studies are necessary to determine the precise range of each fire danger class according to fire occurrence data. Copyright © 2010 Royal Meteorological Society
Ligand‐induced changes in the conformational stability and flexibility of glutamate dehydrogenase and their role in catalysis and regulation
Authors: Wacker Sarah A. , Bradley Michael J. , Marion Jimmy , Bell Ellis 
Published: July 2010

AbstractBovine glutamate dehydrogenase (GDH) is allosterically regulated and requires substrate‐induced subunit interactions for maximum catalytic activity. Steady‐state and presteady‐state kinetics indicate that the rate‐limiting step depends on the nature of the substrate and are likely associated with conformational fluctuations necessary for optimal hydride transfer. Deuterated glutamate shows a steady‐state isotope effect but no effect on the presteady‐state burst rate, demonstrating that conformational effects are rate limiting for hydride transfer while product release is overall rate limiting for glutamate. Guanidine hydrochloride unfolding, heat inactivation, and differential scanning calorimetry demonstrate the effects of alternative substrates, glutamate and norvaline, on conformational stability. Glutamate has little effect on overall stability, whereas norvaline markedly stabilizes the protein. Limited proteolysis demonstrates that glutamate had a variety of effects on local flexibility, whereas norvaline significantly decreased conformational fluctuations that allow protease cleavage. Dynamic light scattering suggests that norvaline stabilizes all interfaces in the hexamer, whereas glutamate had little effect on trimer–trimer interactions. The substrate glutamate exhibits negative cooperativity and complex allosteric regulation but has only minor effects on global GDH stability, while promoting certain local conformational fluctuations. In contrast, the substrate norvaline does not show negative cooperativity or allow allosteric regulation. Instead, norvaline significantly stabilizes the enzyme and markedly slows or prevents local conformational fluctuations that are likely to be important for cooperative effects and to determine the overall rate of hydride transfer. This suggests that homotropic allosteric regulation by the enzymatic substrate involves changes in both global stability and local flexibility of the protein.
The negative effect of distraction on performance of robot‐assisted surgical skills in medical students and residents
Authors: Suh Irene H. , Chien Jung‐Hung , Mukherjee Mukul , Park Shi‐Hyun , Oleynikov Dmitry , Siu Ka‐Chun 
Published: July 2010

AbstractBackgroundModern surgical practice often requires multitasking in operating rooms, generally full of distractions. The purpose of this research was to investigate the effect of distraction on robot‐assisted surgical skill performance in medical students and residents.MethodsFourteen subjects performed a suture‐tying task with the da Vinci™ surgical system with distractive secondary tasks simultaneously. The time to task completion, speed and the total distance travelled were analysed. Two‐way repeated‐measures ANOVA were applied. The scores of secondary tasks were analysed.ResultsA significant secondary task effect was found with an increase of the time to task completion (p = 0.003) and decreased average speed (p < 0.001). The performance of secondary task for residents was significantly better than students.ConclusionsThe performance of a robot‐assisted surgical task was negatively affected by secondary tasks. However, residents with more surgical experience demonstrated a larger attention capacity for multitasking. Therefore, understanding how medical trainees respond to the distractive secondary tasks while performing robot‐assisted surgical task is important in developing a surgical training programme based on the concept of attention. Copyright © 2010 John Wiley & Sons, Ltd.
Simple yet stable bearing‐only navigation
Authors: Krajník Tomáš , Faigl Jan , Vonásek Vojtěch , Košnar Karel , Kulich Miroslav , Přeučil Libor 
Published: July 2010

AbstractThis article describes a simple monocular navigation system for a mobile robot based on the map‐and‐replay technique. The presented method is robust and easy to implement and does not require sensor calibration or structured environment, and its computational complexity is independent of the environment size. The method can navigate a robot while sensing only one landmark at a time, making it more robust than other monocular approaches. The aforementioned properties of the method allow even low‐cost robots to effectively act in large outdoor and indoor environments with natural landmarks only. The basic idea is to utilize a monocular vision to correct only the robot's heading, leaving distance measurements to the odometry. The heading correction itself can suppress the odometric error and prevent the overall position error from diverging. The influence of a map‐based heading estimation and odometric errors on the overall position uncertainty is examined. A claim is stated that for closed polygonal trajectories, the position error of this type of navigation does not diverge. The claim is defended mathematically and experimentally. The method has been experimentally tested in a set of indoor and outdoor experiments, during which the average position errors have been lower than 0.3 m for paths more than 1 km long. © 2010 Wiley Periodicals, Inc.
Effect of poly(vinyl)pyrrolidone on the zeta potential and water loss of raw and Na‐rich Saudi bentonite
Authors: Al Juhaiman Layla A. , Mekhamer Wafaa K. , Al‐Boajan Abeer M. 
Published: July 2010

AbstractThe influence of poly (vinyl) pyrrolidone (PVP) adsorption on the zeta potential and water loss of raw Saudi bentonite (B) and Na‐rich Saudi bentonite (Na‐B) suspensions was investigated. Phase analysis of raw Saudi bentonite was characterized by XRD, and chemical analysis was investigated by XRF. Adsorption study was performed by patch technique. The zeta potential and water loss of B and Na‐B suspensions were measured at different PVP concentrations. PVP adsorption on B was fitted by Freundlich model. For Na‐B, the adsorption isotherm closely fitted the Langmuir model and showed a higher affinity and greater adsorbed amount of PVP than B. Before addition of PVP the zeta potentials of B and Na‐B suspensions were − 30 and − 41 mV, respectively. In presence of PVP the zeta potential of raw bentonite suspension decreased, then increased with increasing PVP concentration; the reverse trend was observed in the case of Na‐B suspension. The presence of PVP greatly influenced the water loss of B dispersion but had a slight effect in the case of Na‐B. Copyright © 2010 John Wiley & Sons, Ltd.
Electrochemical noise analysis of pitting corrosion of J55 steel in NaCl + NaHCO3 electrolytes
Authors: Zhang Jun , Zhao Wenzhen 
Published: July 2010

AbstractElectrochemical noise (EN) was used to study the pitting corrosion of J55 steel in NaCl/NaHCO3 electrolytes. Below critical ratio for Cl− to HCO−, the corrosion rate increased with added NaCl, and conversely, decreased above that level. Also, the critical ratio was between 1 and 1.66. The PSD for potential and current noise were linear and rather gently sloped. J55 casing steel was quite sensitive to NaCl/NaHCO3 electrolytes. Copyright © 2010 John Wiley & Sons, Ltd.
Epileptogenic insult alters endogenous adenosine control on long‐term changes in synaptic strength by theta pattern stimulation in hippocampus area CA1
Authors: Salmani Mahmoud Elahdadi , Fathollahi Yaghoub , Mirnajafizadeh Javad , Semnanian Saeed 
Published: July 2010

AbstractThe impact of theta patterning of the stimulation on the kindling effects of pentylenetetrazol (PTZ) was studied in rat hippocampus area CA1 in vitro. A potential involvement of adenosine A1 receptors was also examined. Primed‐bursts stimulation (PBs) and theta pulse stimulation (TPS) were used as patterned activities. Stimulus patterns were applied to the Schaffer collateral afferents of hippocampal slices from both control and PTZ‐kindled rats, the field excitatory postsynaptic potentials (fEPSP) and population spikes (PS) were simultaneously recorded from stratum radiatum and stratum pyramidale, respectively. Experiments were carried out in the presence or absence of the adenosine A1 receptor antagonist CPX. The following changes in kindled vs. control slices were observed. PBs was unable to produce both fEPSP LTP and PS LTP in untreated slices. When A1 receptor antagonist CPX was applied before PBs, both fEPSP LTP and PS LTP were elicited. PS LTP was selectively depressed by TPS (applied at 60 min after LTP induction) exclusively when A1 receptors were blocked, while TPS failed to depress PS LTP in untreated PBs‐exposed slices. These findings suggest that seizing entails lasting changes in hippocampus area CA1 so that LTP induction by PBs is masked due to intensive adenosine release which in turn prevents TPS to induce PS LTD in epileptic CA1 network. Synapse, 2010. © 2010 Wiley‐Liss, Inc.
Philosophy of mind
Authors: Rey Georges 
Published: July 2010

AbstractPhilosophy of mind concerns questions about mental phenomena that empirical research alone can't settle, such as the nature of mental states and which sorts of things can have them—only living things, or also machines? Settling them requires reflection on such phenomena as consciousness, rationality, and intentionality; the ‘explanatory gaps’ that seem to exist between these; and underlying physical phenomena and the different strategies—dualist, eliminativist, physicalist, and functionalist—that have been proposed for dealing with them. Copyright © 2010 John Wiley & Sons, Ltd.This article is categorized under:Philosophy > Foundations of Cognitive Science