bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of crosslinking on the performance of a collagen‐derived biomaterial as an implant for soft tissue repair: A rodent model
Authors: de Castro Brás Lisandra E. , Proffitt Joanne L. , Bloor Steve , Sibbons Paul D. 
Published: September 2010

AbstractOne of the main problems in healthcare is the loss of tissues resulting from diseases, post‐surgery complications or trauma. As a result there is a need for biomaterials designed to promote tissue regeneration and improve wound healing. This study assessed the effect of crosslinking of a porcine dermal collagen matrix with regard to strength of implant/host tissue integration, implant biocompatibility and general healing in a rodent model. Permacol™, a crosslinked acellular collagenous biomaterial was compared with its noncrosslinked equivalent at 3, 6, and 12 months postsubcutaneous implantation. Both matrices were well tolerated and showed no evidence of inflammation or adverse responses either in the host tissue or implants. Progressive integration of the implants with the surrounding tissue was observed. Cellular response was similar for both collagenous matrices although, at 3 and 6 months, noncrosslinked implants showed a significantly higher level of cellular penetration than crosslinked implants. However, at 12 months crosslinked implants showed significantly higher levels of cellular density, neo‐vascularisation and integration with host tissue. Additionally, at long term, noncrosslinked implants lost volume suggesting some absorption. The crosslinking process does not seem to be detrimental to cellular response and biocompatibility. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010.
Preparation and characterization of novel alkali‐activated nano silica cements for biomedical application
Authors: Lin Qing , Lan Xianghui , Li Yanbao , Ni Yaru , Lu Chunhua , Chen Yixin , Xu Zhongzi 
Published: September 2010

AbstractThe major goal of this study was to investigate and characterize novel Ca(OH)2‐activated nano silica (SiO2) cements for the potential application as a bone cement. Novel Ca(OH)2‐activated nano‐SiO2 powders composed of Ca(OH)2 and nano‐SiO2 were easily prepared, and the deionized water was used as the liquid phase. The initial and final setting times of Ca(OH)2‐activated nano‐SiO2 cements with liquid to powder (L/P) ratios of 1.00–1.33 mL g−1 range from 50 ± 1 to 120 ± 3 min and 96 ± 2 to 190 ± 5 min, respectively. The calorimetric curves indicate that the heat liberations of Ca(OH)2‐activated nano‐SiO2 cements (105.57–138.01 J g−1) are lower than that of C3S (about 150 J g−1). The Ca(OH)2‐activated nano‐SiO2 pastes are injectable under general extrusion force of 100 N, and their compressive strengths with suitable L/P ratios are 5–9 MPa, which is comparable with that of cancellous bone. The in vitro bioactivity of the Ca(OH)2‐activated nano‐SiO2 cement pastes were investigated by soaking in simulated body fluid for various periods. The results show amorphous apatite deposits on the paste surfaces after soaking in simulated body fluid for 2 h. With the prolonged soaking time, amorphous apatite transforms into crystalline apatite after soaking for 1 day. The Ca(OH)2‐activated nano‐SiO2 cements have short setting times, low heat liberation, injectability, suitable compressive strength, and excellent in vitro bioactivity, and may be used as bioactive bone cements for bone regeneration. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010.
Optimal selection of biological tissue using the energy dissipated in the first loading cycle
Authors: Rojo Francisco J. , Páez José M. García , Jorge‐Herrero Eduardo , Atienza José M. , Millán Isabel , Rocha Aurora , de Córdova Alfonso Hoyos Fernández , Guinea Gustavo V. 
Published: September 2010

AbstractCalf pericardium, similar to that used in the manufacturing of prosthetic valve cusps, was fatigue tested. After six batches of 100 cycles of 1 MPa of loading pressure, half of the samples broke. The mean energy dissipated in the first cycle by the surviving samples was 0.16 J, which is lower than the 0.28 J dissipated by the specimens that broke (p = 0.005). The hysteresis of the first cycle was characteristic and different from the following ones and correlated superbly with fatigue resistance. Setting a threshold value for the energy of the first cycle of 0.20 J, the performance index (the percentage of true predictions) was almost 80%, and the area under the ROC curve was 0.823 (maximum value is 1). When including the mean thickness in the selection parameters, as an indirect measure of the specimen mass, the performance index grew over 95%, meaning that the error of the predictions was less than 5%. Combining both parameters in one, a high performance index is maintained at 87.5% and the area under the ROC curve increases to 0.917. This non‐destructive method should help optical methods in the process of selecting the most appropriate and homogenous biological material. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010.
An alginate hydrogel dura mater replacement for use with intracortical electrodes
Authors: Nunamaker Elizabeth A. , Kipke Daryl R. 
Published: September 2010

AbstractThe collagenous dura mater requires a secure closure following implantation of neural prosthetic devices to avoid complications due to cerebrospinal fluid leakage and infections. Alginate was previously suggested for use as a dural sealant. The liquid application and controllable gelling conditions enable alginate to conform to the unique geometries of a neural prosthetic device and the surrounding dura mater to create a barrier with the external environment. In this study, we evaluated the use of alginate as a method to securely reclose a dural defect and seal around an untethered microscale neural probe in the rabbit model. After 3 days and 3 weeks, the sealing strength of alginate remained eight times greater than normal rabbit intracranial pressure and similar in both the presence and absence of a penetrating neural probe. For time points up to 3 months, there was no significant difference in dura mater fibrosis or thickness between alginate and controls. Application of alginate to a dural defect results in a watertight seal that remains intact while the dura mater reforms. These findings indicate that alginate is an effective tool for sealing around microscale neural probes and suggests broader application as a sealant for larger neural prosthetic devices. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010.
Simple method to prepare size‐controllable gold nanoparticles in solutions and their applications on surface‐enhanced Raman scattering
Authors: Yu Chung‐Chin , Liu Yu‐Chuan , Yang Kuang‐Hsuan , Tsai Hui‐Yen 
Published: September 2010

AbstractWe report here, for the first time, a simple method to prepare size‐controllable Au nanoparticles (NPs) in aqueous solutions from bulk Au substrates. First, chitosan (Ch)‐capped Au‐containing complexes were prepared by electrochemical oxidation–reduction cycles in 0.1 N NaCl and 1 g/l Ch solutions. Then the solutions were heated from room temperature to boiling at different heating rates to synthesize size‐controllable Au NPs. The particle sizes of the prepared Au(111) NPs could be controlled from 5 to 30 nm with an increase of the heating rate during preparation. Experimental results indicate that the prepared Au(111) NPs with diameters ranging from 10 to 30 nm can serve as surface‐enhanced Raman scattering active probes for molecules of rhodamine 6G. Copyright © 2010 John Wiley & Sons, Ltd.
Short‐time photodecay dynamics of meso‐tetra(p‐hydroxyphenyl)porphine in the condensed phase explored via resonance Raman spectroscopy and density functional theory calculation
Authors: Wu Zhangzhu , Xu Jun , Wan Junmin , Zheng Xuming , Wang Huigang , Tan Yao 
Published: September 2010

AbstractResonance Raman (RR) spectra of free‐base meso‐tetra(p‐hydroxyphenyl)porphine(THPP) were obtained with 397.9, 416 and 514 nm excitation wavelengths, and density functional calculations were carried out to help the elucidation of the photorelaxation dynamics of Soret (Bx and By bands) electronic transitions and the RR spectra of THPP. The RR spectrum indicates that the Franck–Condon (FC) region photorelaxation dynamics for the S0 → S5 excited electronic state is predominantly along the totally symmetric CmphC stretching and the CβCβ stretchingand simultaneously along the asymmetric (CmCα)as stretching, ν(phCC)asstretching, δ(NH)s and γ(CβH) vibrational relaxation processes, while that for S0 → S4 electronic state is predominantly along the CmphC stretching and pyrrole breathing. The excited‐state structural dynamics of THPP determined from the RR spectra shows that internal conversion (IC) By → Bx electronic relaxation occurs in tens of femtoseconds, and the short‐time dynamics is interpreted using the time‐dependent wave packet theory and Herzberg–Teller (vibronic coupling) contributions. Copyright © 2010 John Wiley & Sons, Ltd.
High‐Performance Polybenzoxazine Nanocomposites Containing Multifunctional POSS Cores Presenting Vinyl‐Terminated Benzoxazine Groups
Authors: Huang Kai‐Wei , Kuo Shiao‐Wei 
Published: September 2010

AbstractWe have prepared a new class of polybenzoxazine/POSS nanocomposites through the reactions of a multifunctional vinyl‐terminated VBa‐POSS with a VBa monomer at various compositional ratios. The incorporation of the silsesquioxane core units into the polybenzoxazine matrix significantly hindered the mobility of the polymer chains and enhanced the thermal stability of these hybrid materials. Increasing the POSS content in these hybrids improved their thermal and mechanical properties, relative to those of the neat polybenzoxazine, because of hydrogen bonding between the siloxane groups of the POSS core units and the OH groups of the polybenzoxazine moieties, as adjudged using FTIR spectroscopy.
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Synthesis of Tung‐Oil‐Based Reactive Diluents
Authors: Wutticharoenwong Kosin , Soucek Mark D. 
Published: September 2010

AbstractThree new reactive diluents were prepared from tung oil using a Diels‐Alder reaction. The dienophiles were methacryloxypropyl trimethoxysilane (MAS), 2,2,2‐trifluoroethyl methacrylate (TFM) and triallyl ether acrylate (TAEA). The chemical structures were evaluated using 1H NMR, 13C NMR, FT‐IR, GPC and MALDI‐TOF‐MS. Spectra evidence (NMR, MS) indicated that a six‐member ring were formed in all three reactions indicating a Diels‐Alder adduct. The reactive diluents were formulated with a soya‐based alkyd to evaluate viscosity reduction and drying time. The viscosity of alkyd was reduced up to 70% using the reactive diluents. The drying time for the autoxidative reactive diluents with alkyds were 1.8‐1‐7 times faster than alkyd alone.
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Responsive Hybrid Polymeric/Metallic Nanoparticles for Catalytic Applications
Authors: Zhang Jian‐Tao , Wei Gang , Keller Thomas F. , Gallagher Hilary , Stötzel Christian , Müller Frank A. , Gottschaldt Michael , Schubert Ulrich S. , Jandt Klaus D. 
Published: September 2010

AbstractThe aims of the current study were to synthesize new responsive polymeric microgels with embedded silver nanoparticles and then to employ these particles as catalyst for reduction reactions. To these ends, stimuli‐responsive microgels from PNIPAAm and the chitosan derivative were firstly synthesized by free radical precipitation polymerization. Then, silver nanoparticles were synthesized inside these microgel networks by in situ reduction of AgNO3. These microgels were temperature/pH sensitive with a phase transition temperature of 32–35 °C in water at pH = 3 and 8, respectively. The catalytic activity of the Ag nanoparticles for the reduction of 4‐nitrophenol can be tuned through the swelling or collapse of the responsive microgel network hosting the active nanoparticles.
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Synthesis of Organosilane‐Modified Carbon Nanofibers and Influence of Silane Coating Thickness on the Performance of Polyethylene Nanocomposites
Authors: Wood Weston , Kumar Sandeep , Zhong Wei‐Hong 
Published: September 2010

AbstractSilane coatings with different thicknesses were synthesized on CNFs for reinforcement of polyethylene composites. The thickness of the silane coating was adjusted by using a basic catalyst to increase the overall reactivity of the silane groups, resulting in a thick coating of ≈46 nm (ca. 90% increase in fiber diameter). DMA performed on the polyethylene composites showed a substantial increase in storage modulus from 1.68 to 2.34 GPa (40%) at low temperatures in the composite with the thick silane coating (≈46 nm) at a low loading of 0.4 wt.‐%. We believe that the silane‐treated nanofillers with thick coatings are very promising for high‐performance nanocomposites with non‐polar polymer matrices.
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Folding of Polyalanine into Helical Hairpins
Authors: Palenčár Peter , Bleha Tomáš 
Published: September 2010

AbstractThe variation of the secondary structure and dimensions of long PA peptides was examined by means of all‐atom MD simulations. It was found that on cooling, instead of straight helices, hairpin‐like structures with two and three parallel helical legs were formed. The exclusive population of hairpins in PA at room temperature was proved by the bimodality of the distribution functions of the end‐to‐end distance and the radius of gyration. The helix‐turn‐helix motif revealed in PA simulations is pertinent for the structure of transmembrane proteins. The potential energy analysis showed a crucial role of the van der Waals forces in stabilization of the hairpins. It was underlined that this is a feature shared with folding of hydrocarbon chains, such as PE, into the crystal lamellae.
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Current Awareness in NMR in Biomedicine
Authors:   John Wiley & Sons, Ltd.
Published: September 2010

AbstractIn order to keep subscribers up‐to‐date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of NMR in biomedicine. Each bibliography is divided into 12 sections: 1 Reviews; 2 General; 3 Technology; 4 Contrast Agents; 5 Brain and Nerves; 6 Neuropathology; 7 Cancer; 8 Cardiac, Vascular and Respiratory Systems; 9 Liver, Kidney and Other Organs; 10 Muscle and Orthopaedic; 11 Plants, Micro‐organisms and Parasites; 12 Others. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted.
Condition number bounds and mesh quality
Authors: Branets L. , Carey G. F. 
Published: September 2010

AbstractWe analyze the effect of mesh distortion on the condition number of the representative mass matrix M and stiffness matrix K arising in a typical finite element scheme. Bounds are stated for the respective condition numbers in terms of the Jacobian of the map from a reference element. These results are then used to construct the related bounds in terms of representative metrics for mesh distortion. These bounds are easily pre‐computable and provide a new explicit mathematical relation between matrix conditioning and mesh quality metrics. Numerical studies for a 2D test problem using a representative cell quality metric demonstrate the upper bound property and the dependence on cell quality for a quadrilateral cell. Analogous results for a 3D test problem under progressive symmetric mesh distortion of an interior hexahedral cell are also provided, as well as a study on a complex 3D geometry. We conclude by presenting practical adaptive mesh grading applications employing aforementioned mesh quality metrics. Copyright © 2010 John Wiley & Sons, Ltd.
An enhanced energy conserving time stepping algorithm for frictionless particle contacts
Authors: Bravo R. , Pérez‐Aparicio J. L. , Laursen T. A. 
Published: September 2010

AbstractAn Enhanced Energy Conserving Algorithm (EECA) formulation for time integration of frictionless contact–impact problems is presented. In it the energy, linear and angular momentum are conserved for every contact using an enhanced Penalty method. Previous formulations for these problems have shown that the total bodies' energy decreases for contact due to an artificial energy transfer between the penalty spring and the contacting bodies. Consequently, they are not able to reproduce a physical response after a single contact, introducing errors in trajectories and velocities.Through the conserving balance equations, EECA computes a physical response by inserting for every contact an additional amount of linear momentum and contact force. The structure of these equations defines the additional linear momentum to restore the energy and the enhanced Penalty method based on a spring and a dashpot. This method approximately enforces the first and second Kuhn–Tucker conditions.The new algorithm has been applied to several frictionless rigid problems using the Discrete Element Method. The first two problems consist of the simulation and analytical comparison of the Newton's Cradle and Carom problems (billiard pool problem). The last two are the hopper filling process and the breaking of a pool ball's triangular arrangement, both of which involve a medium number of contacts. Application of this formulation will be straightforward to elastic and general‐shaped bodies using the Finite Element Method. Copyright © 2010 John Wiley & Sons, Ltd.
A simple multi‐directional absorbing layer method to simulate elastic wave propagation in unbounded domains
Authors: Semblat Jean‐François , Lenti Luca , Gandomzadeh Ali 
Published: September 2010

AbstractThe numerical analysis of elastic wave propagation in unbounded media may be difficult due to spurious waves reflected at the model artificial boundaries. This point is critical for the analysis of wave propagation in heterogeneous or layered solids. Various techniques such as Absorbing Boundary Conditions, infinite elements or Absorbing Boundary Layers (e.g. Perfectly Matched Layers) lead to an important reduction of such spurious reflections. In this paper, a simple absorbing layer method is proposed: it is based on a Rayleigh/Caughey damping formulation which is often already available in existing Finite Element softwares. The principle of the Caughey Absorbing Layer Method is first presented (including a rheological interpretation). The efficiency of the method is then shown through 1D Finite Element simulations considering homogeneous and heterogeneous damping in the absorbing layer. 2D models are considered afterwards to assess the efficiency of the absorbing layer method for various wave types and incidences. A comparison with the PML method is first performed for pure P‐waves and the method is shown to be reliable in a more complex 2D case involving various wave types and incidences. It may thus be used for various types of problems involving elastic waves (e.g. machine vibrations, seismic waves, etc.). Copyright © 2010 John Wiley & Sons, Ltd.
Worst‐case analysis of distributed parameter systems with application to the 2D reaction–diffusion equation
Authors: Kishida Masako , Braatz Richard D. 
Published: September 2010

AbstractIt is well known that optimal control trajectories can be highly sensitive to perturbations in the model parameters. Computationally efficient numerical algorithms are presented for the worst‐case analysis of the effects of parametric uncertainties on boundary control problems for finite‐time distributed parameter systems. The approach is based on replacing the full‐order model of the system with a power series expansion that is analyzed by linear matrix inequalities or power iteration, which are polynomial‐time algorithms. Theory and algorithms are provided for computing the most positive and most negative worst‐case deviation in a state or output, in contrast to the ‘two‐sided’ deviations normally computed in worst‐case analyses. Application to the Dirichlet boundary control of the reaction–diffusion equation to track a desired two‐dimensional concentration field illustrates the promise of the approach. Copyright © 2010 John Wiley & Sons, Ltd.
Optimal control of the atmospheric reentry of a space shuttle by an homotopy method
Authors: Hermant Audrey 
Published: September 2010

AbstractThis paper deals with the optimal control problem of the atmospheric reentry of a space shuttle with a second‐order state constraint on the thermal flux. We solve the problem using the shooting algorithm combined with an homotopy method, which automatically determines the structure of the optimal trajectory (composed of one boundary arc and one touch point). Copyright © 2010 John Wiley & Sons, Ltd.
Photovoltaics literature survey (No. 81)
Authors: Shrestha Santosh 
Published: September 2010

AbstractIn order to help keep readers up‐to‐date in the field each issue of Progress in Photovoltaics will contain a list of recently published journal articles most relevant to its aims and scope. This list is drawn from an extremely wide range of journals, including IEEE Transactions on Electron Devices, Journal of Applied Physics, Applied Physics Letters, Progress in Photovoltaics and Solar Energy Materials and Solar Cells. To assist the reader, the list is separated into broad categories, but please note that these classifications are by no means strict. Also note that inclusion in the list is not an endorsement of a paper's quality. If you have any suggestions please email Santosh Shrestha at s.shrestha@unsw.edu.au.
Hydrogen abstraction from H‐donor substrates by the 6‐CF3‐benzotriazol‐N‐oxyl radical (TFNO)
Authors: Tadesse Mahelet Aweke , Galli Carlo , Gentili Patrizia 
Published: September 2010

AbstractThe aminoxyl radical 6‐trifluoromethyl‐benzotriazol‐N‐oxyl (TFNO) has been generated from the parent hydroxylamine 6‐CF3‐1‐hydroxy‐benzotriazole (TFBT) by one‐electron oxidation with a CeIV salt and characterized by spectrophotometry and cyclic voltammetry (CV). Rate constants of H‐abstraction (kH) by TFNO from a number of H‐donor benzylic substrates have been determined spectrophotometrically in MeCN solution at 25 °C. A radical H‐atom transfer (HAT) route of oxidation is substantiated for TFNO by several pieces of evidence. The kinetic data also testify the relevance of stereoelectronic effects upon the HAT reactivity of TFNO. Copyright © 2010 John Wiley & Sons, Ltd.
Application of activation hardness in perturbed pericyclic reactions: a case study involving electrocyclic ring opening reactions of heterocyclobutenes
Authors: Jaccob M. , Sheeba Jem I. , Giri Santanab , Venuvanalingam P. , Chattaraj P. K. 
Published: September 2010

AbstractCyclobutene undergoes electrocyclic ring opening through conrotatory mode to give 1,3‐butadiene and similarly its skeletally substituted analogues viz. phosphetene, thietene, oxetene and azetene isomerize to give their respective heterodienes. Quantum mechanical investigations on these perturbed pericyclic isomerizations at B3LYP level with 6‐31G(d) and 6‐311 + G(d,p) basis sets reveal that hetero ‐ atoms significantly lower the barrier and alter the reaction free energies. Interestingly frontier orbital correlation diagram shows that σ and σ* levels are perturbed significantly while π and π* levels undergo little changes during the reaction; the lone pairs on hetero – atoms are slightly stabilized in the TS. This results in σ becoming HOMO in the TSs of phosphetene and thietene isomerizations and σ* becoming LUMO in all the cases. This necessitates defining hardness values based on closely interacting frontier orbitals for reactants and TSs and use them to compute activation hardness values to interpret relative reactivity. Copyright © 2010 John Wiley & Sons, Ltd.