bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diversity and fluctuation of spine morphology in CA1 pyramidal neurons after transient global ischemia
Authors: Ruan Yi‐Wen , Lei Zhigang , Fan Yuan , Zou Bende , Xu Zao C. 
Published: August 2008

AbstractDendritic spines form postsynaptic components of excitatory synapses in CA1 pyramidal neurons and play a key role in excitatory signal transmission. Transient global ischemia is thought to induce excitotoxicity that triggers delayed neuronal death in the CA1 region. However, the mechanism underlying structural changes of excitatory synapses after ischemia is not completely understood. Here, we demonstrate how dendritic spines change in their density and structure at an acute stage after transient global ischemia. Intracellular staining in vivo showed that the total spine density in basal, proximal, and distal apical dendrites increased at 12 hr and 24 hr after ischemia, but returned to control levels at 48 hr after ischemia. Consistent increase of spine density mainly appeared in non‐late depolarizing postsynaptic potential neurons, although late depolarizing postsynaptic potential neurons also showed slight increases in spine density in these dendrites at the same intervals after ischemia. Golgi staining showed increased spine density occurred in less swollen dendrites but decreased spine density appeared in severely swollen dendrites at 12 and 24 hr after ischemia. In addition, the density and percentage of stubby spines reduced at 12 hr and 48 hr, whereas the density of thin spines increased at 12 hr after ischemia. The density and percentage of filopodia increased nearly fivefold at 24 hr after ischemia. Moreover, the density of mushroom spines doubled and its percentage increased by 150% at 48 hr after ischemia. These morphological changes of spines may be related to neuronal injury in CA1 pyramidal neurons after ischemia. © 2008 Wiley‐Liss, Inc.
Raman spectroscopic study of the mineral guilleminite Ba(UO2)3(SeO3)2(OH)4·3H2O
Authors: Frost Ray L. , Čejka Jiří , Dickfos Marilla J. 
Published: August 2008

AbstractThe Raman spectrum of the mineral guilleminite Ba[(UO2)3O2(SeO3)2](H2O)3 was studied and complemented by the infrared spectrum of this mineral. Both spectra were interpreted and compared with the spectra of marthozite, larisaite, haynesite and piretite, all of which should have the same phosphuranylite anion sheet topology. The presence of symmetrically distinct water molecules and hydrogen bonds was inferred from the spectra. This is in agreement with the crystal structural analysis of guilleminite. UO bond lengths in uranyl and OH···O hydrogen bond lengths were calculated from the Raman and/or infrared spectra of guilleminite. Copyright © 2008 John Wiley & Sons, Ltd.
Raman spectroscopic study of the selenite mineral mandarinoite Fe2Se3O9·6H2O
Authors: Frost Ray L. , Keeffe Eloise C. 
Published: August 2008

AbstractSelenites and tellurites may be subdivided according to formula and structure. There are five groups, based upon the formulae (a) A(XO3), (b) A(XO3·) xH2O, (c) A2(XO3)3·xH2O, (d) A2(X2O5) and (e) A(X3O8). Of the selenites, molybdomenite is an example of type (a); chalcomenite, clinochalcomenite, cobaltomenite and ahlfeldite are minerals of type (b); mandarinoite Fe2Se3O9·6H2O is an example of type (c). Raman spectroscopy has been used to characterise the mineral mandarinoite. The intense, sharp band at 814 cm−1 is assigned to the symmetric stretching (Se3O9)6− units. Three Raman bands observed at 695, 723 and 744 cm−1 are attributed to the ν3 (Se3O9)6− anti‐symmetric stretching modes. Raman bands at 355, 398 and 474 cm−1 are assigned to the ν4 and ν2 bending modes. Raman bands are observed at 2796, 2926, 3046, 3189 and 3507 cm−1 and are assigned to OH stretching vibrations. The observation of multiple OH stretching vibrations suggests the non‐equivalence of water in the mandarinoite structure. The use of the Libowitzky empirical function provides hydrogen bond distances of 2.633(9) Å (2926 cm−1), 2.660(0) Å (3046 cm−1), 2.700(0) Å (3189 cm−1) and 2.905(3) Å (3507 cm−1). The sharp, intense band at 3507 cm−1 may be due to hydroxyl units. It is probable that some of the selenite units have been replaced by hydroxyl units. Copyright © 2008 John Wiley & Sons, Ltd.
Pressure‐induced phase transitions in L‐leucine crystal
Authors: Façanha Filho P. F. , Freire P. T. C. , Melo F. E. A. , Lemos V. , Mendes Filho J. , Pizani P. S. , Rossatto D. Z. 
Published: August 2008

AbstractRaman spectra of a crystal of L‐leucine, an essential amino acid, were obtained for pressures between 0 and 6 GPa. The results show anomalies at three pressure values, one between 0 and 0.46 GPa, another between 0.8 and 1.46 GPa, and a third at P ∼ 3.6 GPa. The first two anomalies are characterized by the disappearance of lattice modes (which can indicate occurrence of phase transitions), the appearance of several internal modes, or the splitting of modes of high wavenumbers. The changes of internal modes are related to CH and CH3 unit motions as well as hydrogen bonds, as can be inferred from the behavior of bands associated with CO2− moieties. The third anomaly is a discrete change of the slopes of the wavenumber versus pressure plots for most modes observed. Further, decompression to ambient pressure generates the original Raman spectrum, showing that the pressure‐induced anomalies undergone by L‐leucine crystals are reversible. Copyright © 2008 John Wiley & Sons, Ltd.
Differentiation and quantification of xylene isomers by combining headspace solid‐phase microextraction/gas chromatography and self‐ion molecule reaction in an ion trap tandem mass spectrometry
Authors: Yang Chih‐Hao , Khan Nadeem Ahmad , Wu Hui‐Fen 
Published: August 2008

AbstractA headspace solid‐phase microextraction (HS‐SPME) method using polydimethylsiloxane (PDMS)‐coated fiber coupling with GC/self‐ion molecule reaction (SIMR)/MS/MS (GC/SIMR/MS/MS) has been developed for the differentiation of o‐, m‐, and p‐xylene isomers. The optimization parameters of this method are: extraction time 20 min, stirring rate 1200 rpm, sampling temperature 28°C, and salt concentration 5%. The LODs were found to be in the range of 3–9 ng/mL under the SIM mode of GC/MS. The RSDs were below 1% (n = 5). The linear dynamic range of the calibration curve was from 0.05 to 10.0 μg/mL with correlation coefficient (r2) > 0.9089. The advantages of this technique are sensitive, selective, ease of operation, simple device, solvent free, and extremely little sample consumption. This technique is the first example using SIMR combined MS/MS applied in the GC/MS and it can be applied to other volatile compounds for future application.
Robust open tubular layer ofS‐ketoprofen imprinted polymer for chiral LC separation
Authors: Zaidi Shabi Abbas , Cheong Won Jo 
Published: August 2008

AbstractThis study is about the preparation of an open tubular capillary column of molecularly imprinted polymer (MIP) and its application to chiral separation by μLC. A non‐covalentin‐situmolecular imprinting polymerization protocol was used to synthesize theS‐ketoprofen MIP. A special procedure was employed to secure formation of an open tubular and rigid MIP layer in a silica capillary of 100 μm id. The capillary was filled with the reaction mixture, sealed, and placed in a water bath at 50°C for 3 h. Then it was flushed with a 0.5 MPa nitrogen flow for 5 min, and was again placed in the water bath for 2 h to complete MIP formation. Methacrylic acid (MAA) has been known to be an inefficient functional monomer in preparation of MIP of an acid molecule. However, MAA was used with ethylene glycol dimethacrylate in preparation of theS‐ketoprofen MIP in this study. The open tubular structure and the μLC mode of separation enabled free optimization without any restriction, thus a very good resolution (R= 4.7) of ketoprofen enantiomers was achieved when a mobile phase composed of 30% acetonitrile and 70% acetate buffer at pH 4.5 was used with 5 mbar inlet pressure. This may be partially attributed to the open tubular structure of our MIP, enabling low column back‐pressure and free optimization of eluent composition, as well as to the small capillary dimensions. Our MIP capillary column also showed some versatility in chiral separation, thus a good chiral separation was observed for naproxen, ibuprofen, and fenoprofen enantiomers.
Resonance Rayleigh scattering for detection of proteins in HPLC
Authors: Lu Xin , Luo Zhihui , Liu Chengwei , Zhao Shulin 
Published: August 2008

AbstractAn HPLC–resonance Rayleigh scattering (RRS) (HPLC–RRS) detection system is described for separation and detection of proteins. This system is based on the modification of a commercial HPLC instrument involving the addition of a pump and a T‐shaped interface, and a common fluorescence detector was used for detection. The detection principle is based on the change of RRS intensity of the ion‐association complex formed from biebrich scarlet (BS) and protein. The RRS signal was detected at λex = λem = 376 nm. The utility of the presented method was demonstrated by the separation and determination of four proteins involving cytochrome (Cyt‐c), lysozyme (Lys), HSA, and γ‐globulin (γ‐Glo). An LOD of 0.2–1.0 μg/mL was reached and a linear range was found between peak area and concentration in the range of 0.20–3.0 μg/mL for Cyt‐c, 0.25–2.5 μg/mL for Lys, 1.5–10 μg/mL for HSA, and 2.0–15 μg/mL for γ‐Glo, with linear regression coefficients all above 0.99. The method presented has been applied to determine HSA and γ‐Glo in human serum samples synchronously.
On‐Line multitasking analytical proteomics: How to separate, reduce, alkylate and digest whole proteins in an on‐Line multidimensional chromatography system coupled to MS
Authors: Tran Bao Quoc , Loftheim Håvard , Reubsaet Leon , Lundanes Elsa , Greibrokk Tyge 
Published: August 2008

AbstractAn on‐Line multidimensional system has been developed, consisting of pH gradient strong anion exchange chromatography of native proteins in the first dimension with subsequent trapping and on‐column reduction/alkylation on C4 trap columns and RP separation of the alkylated proteins in the second dimension followed by on‐column tryptic digestion and electrospray MS detection. The system was evaluated using model proteins and a human urine sample. Compared to the commonly used in‐solution alkylation method, the developed on‐column method provides an equivalent efficiency. The recovery from the C4 trap columns of the alkylated proteins relative to the native state was from 94 to 102%. On‐column tryptic digestion was satisfactory for many, but not for all proteins. The whole analytical procedure was performed on‐Line with packed capillary columns for a total time of 320 min for the first ion exchange fraction, with additional 60 min for each subsequent fraction.
Supercritical fluid extraction for identification and determination of volatile metabolites from Angelica dahurica by GC‐MS
Authors: Chen Qinhua , Li Peng , He Jing , Zhang Zhuo , Liu Jia 
Published: August 2008

AbstractThe volatile components of Angelica dahurica were obtained by supercritical fluid extraction (SFE) method. These oils obtained were analyzed by GC‐MS (identification and determination of metabolites). The compounds were identified according to their retention indices and mass spectra (electron impact (EI), 70 eV). The effects of different parameters, such as pressure, temperature, flow rate of CO2, and the amount of modifier, on the SFE of A. dahurica oil were investigated. A total of 50 compounds of SFE extracts were identified. Phellopterin (PO), isoimperatorin (IO), imperatorin (IM), alloimperatorin (AM), byakangelicin, isooxypeucedanin, and pimpinellin were the major coumarin compounds identified in A. dahurica SFE extracts. The quantitations of PO, IO, IM, and AM were then accomplished. The calibration curves showed good linearity (R2 >0.99) in the concentration ranges tested. The recoveries were higher than 85%, with RSDs less than 10%. The GC‐MS method was successfully validated and applied to the quantitation of A. dahurica.
Retracted:Comments on ‘Upper bound solution to elasticity problems: A unique property of the linearly conforming point interpolation method (LC‐PIM)’ by G. R. Liu and G. Y. Zhang, International Journal for Numerical Methods in Engineering, DOI: 10.1002/nme.2204
Authors: Liu G. R. , Zhang Guiyong 
Published: August 2008

AbstractThe following article from International Journal for Numerical Methods in Engineering, Comments on ‘Upper bound solution to elasticity problems: A unique property of the linearly conforming point interpolation method (LC‐PIM)’ by G. R. Liu and G. Y. Zhang, published online on 15 August 2008 in Wiley InterScience (www.interscience.wiley.com), has been retracted by agreement between the authors, the journal Editor‐in‐Chief, Ted Belytschko and John Wiley & Sons, Ltd. The retraction has been agreed due to the article being published out of sequence with a related article and with insufficient citation details.
A time‐parallel implicit method for accelerating the solution of non‐linear structural dynamics problems
Authors: Cortial Julien , Farhat Charbel 
Published: August 2008

AbstractThe parallel implicit time‐integration algorithm (PITA) is among a very limited number of time‐integrators that have been successfully applied to the time‐parallel solution of linear second‐order hyperbolic problems such as those encountered in structural dynamics. Time‐parallelism can be of paramount importance to fast computations, for example, when space‐parallelism is unfeasible as in problems with a relatively small number of degrees of freedom in general, and reduced‐order model applications in particular, or when reaching the fastest possible CPU time is desired and requires the exploitation of both space‐ and time‐parallelisms. This paper extends the previously developed PITA to the non‐linear case. It also demonstrates its application to the reduction of the time‐to‐solution on a Linux cluster of sample non‐linear structural dynamics problems. Copyright © 2008 John Wiley & Sons, Ltd.
Upper and lower bounds in limit analysis: Adaptive meshing strategies and discontinuous loading
Authors: Muñoz J. J. , Bonet J. , Huerta A. , Peraire J. 
Published: August 2008

AbstractUpper and lower bounds of the collapse load factor are here obtained as the optimum values of two discrete constrained optimization problems. The membership constraints for Von Mises and Mohr–Coulomb plasticity criteria are written as a set of quadratic constraints, which permits one to solve the optimization problem using specific algorithms for Second‐Order Conic Program (SOCP). From the stress field at the lower bound and the velocities at the upper bound, we construct a novel error estimate based on elemental and edge contributions to the bound gap. These contributions are employed in an adaptive remeshing strategy that is able to reproduce fan‐type mesh patterns around points with discontinuous surface loading. The solution of this type of problems is analysed in detail, and from this study some additional meshing strategies are also described. We particularise the resulting formulation and strategies to two‐dimensional problems in plane strain and we demonstrate the effectiveness of the method with a set of numerical examples extracted from the literature. Copyright © 2008 John Wiley & Sons, Ltd.
A local multigrid X‐FEM strategy for 3‐D crack propagation
Authors: Rannou J. , Gravouil A. , Baïetto‐Dubourg M. C. 
Published: August 2008

AbstractA multiscale method for 3‐D crack propagation simulation in large structures is proposed. The method is based on the extended finite element method (X‐FEM). The asymptotic behavior of the crack front is accurately modeled using enriched elements and no remeshing is required during crack propagation. However, the different scales involved in fracture mechanics problems can differ by several orders of magnitude and industrial meshes are usually not designed to account for small cracks. Enrichments are therefore useless if the crack is too small compared with the element size. To overcome this drawback, a project combining different numerical techniques was started. The first step was the implementation of a global multigrid algorithm within the X‐FEM framework and was presented in a previous paper (Eur. J. Comput. Mech. 2007; 16:161–182). This work emphasized the high efficiency in cpu time but highlighted that mesh refinement is required on localized areas only (cracks, inclusions, steep gradient zones). This paper aims at linking the different scales by using a local multigrid approach. The coupling of this technique with the X‐FEM is described and computational aspects dealing with intergrid operators, optimal multiscale enrichment strategy and level sets are pointed out. Examples illustrating the accuracy and efficiency of the method are given. Copyright © 2008 John Wiley & Sons, Ltd.
Transient heat conduction in a medium with multiple spherical cavities
Authors: Gordeliy Elizaveta , Crouch Steven L. , Mogilevskaya Sofia G. 
Published: August 2008

AbstractThis paper considers a transient heat conduction problem for an infinite medium with multiple non‐overlapping spherical cavities. Suddenly applied, steady Dirichlet‐, Neumann‐ or Robin‐type boundary conditions are assumed. The approach is based on the use of the general solution to the problem of a single cavity and superposition. Application of the Laplace transform and the so‐called addition theorem results in a semi‐analytical transformed solution for the case of multiple cavities. The solution in the time domain is obtained by performing a numerical inversion of the Laplace transform. A large‐time asymptotic series for the temperature is obtained. The limiting case of infinitely large time results in the solution for the corresponding steady‐state problem. Several numerical examples that demonstrate the accuracy and the efficiency of the method are presented. Copyright © 2008 John Wiley & Sons, Ltd.
An efficient numerical method for solid–liquid transitions in optical rewritable recording
Authors: Brusche J. H. , Segal A. , Vuik C. 
Published: August 2008

AbstractMelting and solidification processes are encountered in a variety of industrial applications. Examples include the steel industry, food processing and the recording of data in optical data storage. The phase transition, induced by a heat source, can be described by a two‐phase Stefan formulation. To solve such highly non‐linear moving boundary problems within industrially relevant domains, we propose an extension to 3D space of the temperature‐based method described by Fachinotti et al. (Int. J. Numer. Meth. Engng 1999; 44(12):1863–1884). By the use of discontinuous spatial integration accurate solutions can be efficiently obtained for isothermal problems that are driven by the boundary conditions. However, the temperature approach can fail for isothermal problems that are driven by an (external) source. This is remedied by introducing an artificial mushy region around the melting temperature. The developed method has been applied to 3D optical rewritable recording simulations. Copyright © 2008 John Wiley & Sons, Ltd.
Lattice Boltzmann simulation of dispersion in two‐dimensional tidal flows
Authors: Banda Mapundi K. , Seaïd Mohammed , Thömmes Guido 
Published: August 2008

AbstractA lattice Boltzmann method (LBM) is applied to problems of dispersion in two‐dimensional water flows. The water flow is modelled by shallow water equations. A two‐distribution lattice Boltzmann equation algorithm is presented to solve the pollutant transport problem within the framework of shallow water flow. One distribution models the shallow water flow. The other distribution models the pollutant transport. Flow characteristics and concentration profiles of dispersive species are obtained at various flow regimes. For fast water flow, the concentration profiles are highly affected by the flow advection and become completely different from those at slow water flow. Numerical results are presented for pollutant transport in bounded and open channel flows. The proposed LBM is also used to simulate a pollution event in the Strait of Gibraltar. The obtained results indicate that the present method is useful for the investigation of transport phenomena by shallow water flows in complex geometries and practical flow problems. Copyright © 2008 John Wiley & Sons, Ltd.
A palaeopathological investigation of the third intercondylar tubercle of Parsons
Authors: Mays S. , Cooper L. 
Published: August 2008

AbstractThe third intercondylar tubercle of Parsons (TITP) is a bony protuberance which is sometimes present on the tibial plateau. It corresponds to the insertion of the anterior fibres of the anterior cruciate ligament (ACL). Reasons why TITP is present in some knees and not others are at present unclear. TITP is studied in knee joints from 68 adult individuals from a medieval cemetery. Associations are investigated with age, sex, knee osteoarthritis, clinical and subclinical DISH, and skeletal signs of trauma, with the aim of evaluating existing ideas on the causation of TITP. Only trauma showed an association with the presence of TITP. The results offer support for the aetiology of trauma to the ACL in the formation of TITP. Copyright © 2008 John Wiley & Sons, Ltd.
Numerical methods for the chemical master equation and applications to stochastic models or receptor oligomerisation
Authors: MacNamara Shev , Burrage Kevin , Sidje Roger B. 
Published: August 2008

AbstractThe chemical master equation is an important model for studying chemical kinetics, especially in the context of systems biology where noise is known to play an important role and so a discrete and stochastic framework is required. However due to the high dimensional nature of the equations it has often been felt to be too difficult to tackle numerically, although recently much progress has been made. Here some novel numerical methods are presented and applied to stochastic models of receptor oligomerisation, which have previously been studied only by simulation. This gives a novel perspective on these models and suggests some insights into the phenomena of the role they play in buffering cell signals. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fracture mechanical behaviour of visco‐elastic materials
Authors: Näser Bastian , Kaliske Michael , Dal Hüsnü 
Published: August 2008

AbstractThe material force approach is an efficient, elegant and accepted means to compute the J‐integral as a fracture mechanical parameter for elastic and inelastic materials. With the formulation of a multiplicative split of the deformation gradient at hand, rate‐dependent (visco‐elastic) materials based on the Bergström‐Boyce‐Model can be investigated. For these investigations, the so‐call material body forces have to be computed to separate the driving force acting on the inelastic zone around the crack tip from the driving force acting on the crack tip itself, representing the crack driving force or the J‐integral, respectively. For that purpose, the complete balance for the material motion problem for rate‐dependent, inelastic materials has to be known and the balance has to be fulfilled at every nodal point in a finite element discretization.In this contribution, the so‐called dwell effect should serve as an example for the application of the material force method for inelastic materials. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Experiments in non‐smooth mechanics with a passive‐actuated robotic arm
Authors: Welge‐Luessen Tobias 
Published: August 2008

AbstractThis paper describes various experiments for the parameter identification of a two‐link passive‐actuated robot manipulator. The proposed experiments can be used to determine the flexible properties of the physical structure, especially of both arms and of the shafts within the joints connecting them. In addition experiments for the major joint elements, namely the motor and the electromagnetically powered brake are being presented. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)