bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chromium supplementation improves glucose tolerance in diabetic Goto‐Kakizaki rats
Authors: Abdourahman Aicha , Edwards John G. 
Published: July 2008

AbstractChromium supplementation (Cr) may be useful in the management of diabetes and appears to improve some aspects of glucose handling. However, several studies have used either high doses of Cr supplementation or have placed control animals on a Cr‐deficient diet. We therefore wanted to test whether Cr dosages in the ranges that more closely approximate recommended levels of supplementation in humans are efficacious in glycemic control under normal dietary conditions. Euglycemic Wistar or diabetic Goto‐Kakizaki (GK) rats (a model of nonobese NIDDM) were assigned to water (control) or chromium picolinate (Cr‐P) supplementation (1 or 10 mg/kg/day) groups for up to 32 weeks. Glucose tolerance was tested following an overnight fast by injecting sterile glucose (1.0 g/kg, i.p.) and then measuring blood glucose at select times to determine the sensitivity to glucose by calculation of the area under the curve. Cr‐P did not significantly alter the growth of the animals. In the euglycemic Wistar rats, Cr‐P supplementation did not alter the response to a glucose tolerance test. In the GK rats, Cr‐P supplementation significantly improved glucose tolerance at both levels of Cr‐P supplementation (1 mg/kg/day: H20; 100 ± 11%; Cr‐P 70 ± 8%; 10 mg/kg/day: H20; 100 ± 10%; Cr‐P 66 ± 9 %). Cr‐P supplementation produced a small improvement in some indices of glycemic control. There were no differences observed for the two levels of Cr‐P supplementation suggested that we did not identify a threshold for Cr‐P effects, and future studies may use lower doses to find a threshold effect for improving glucose tolerance in diabetics. © 2008 IUBMB IUBMB Life, 60(8): 541–548, 2008
Versatile laser‐based cell manipulator
Authors: Maghelli Nicola , Tolić‐Nørrelykke Iva M. 
Published: July 2008

AbstractHere we describe a two‐photon microscope and laser ablation setup combined with optical tweezers. We tested the setup on the fission yeast Schizosaccharomyces pombe, a commonly used model organism. We show that long‐term imaging can be achieved without significant photo‐bleaching or damage of the sample. The setup can precisely ablate sub‐micrometer structures, such as microtubules and mitotic spindles, inside living cells, which remain viable after the manipulation. Longer exposure times lead to ablation, while shorter exposures lead to photo‐bleaching of the target structure. We used optical tweezers to trap intracellular particles and to displace the cell nucleus. Two‐photon fluorescence imaging of the manipulated cell can be performed simultaneously with trapping. The combination of techniques described here may help to solve a variety of problems in cell biology, such as positioning of organelles and the forces exerted by the cytoskeleton. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Zinc oxide: A case study in contemporary computational solid state chemistry
Authors: Catlow C. Richard A. , French Samuel A. , Sokol Alexey A. , Al‐Sunaidi Abdullah A. , Woodley Scott M. 
Published: July 2008

AbstractComputational techniques have been applied to study a broad range of chemical and physical properties of zinc oxide. Both interatomic‐potential and density functional theory methods are used to investigate structural, thermodynamic, surface, and defect properties. We survey the structures and energies of nano‐particulate zinc oxide. © 2008 Wiley Periodicals, Inc. J Comput Chem 2008
A combined ab initio and Franck‐Condon factor simulation study on the photodetachment spectrum of ScO2−
Authors: Lee Edmond P. F. , Mok Daniel K. W. , Chau Foo‐Tim , Dyke John M. 
Published: July 2008

AbstractRestricted‐spin coupled‐cluster single‐double plus perturbative triple excitation {RCCSD(T)} potential energy functions (PEFs) of the $ \tilde X $2B2 state of ScO2 and the $ \tilde X $1A1 state of ScO2− were computed, employing the augmented correlation‐consistent polarized‐weighted core‐valence quadruple‐zeta (aug‐cc‐pwCVQZ) basis set for Sc and augmented correlation‐consistent polarized valence quadruple‐zeta (aug‐cc‐pVQZ) basis set for O, and with the outer core Sc 3s23p6 electrons being explicitly correlated. Franck‐Condon factors, which include allowance for Duschinsky rotation and anharmonicity, were calculated using the computed RCCSD(T) PEFs, and were used to simulate the first photodetachment band of ScO2−. The simulated spectrum matches well with the corresponding experimental 355 nm photodetachment spectrum of Wu and Wang, J Phys Chem A 1998, 102, 9129, confirming the assignment of the photodetachment spectrum and the reliability of the RCCSD(T) PEFs used. Further calculations on low‐lying electronic states of ScO2 gave adiabatic relative electronic energies (Te's) of, and vertical excitation energies (Tv's) to, the $ \tilde A $2A1, $ \tilde B $2B1, and $ \tilde C $2A2 states of ScO2 (from the $ \tilde X $2B2 state of ScO2), as well as electron affinities (EAs) and vertical detachment energies (VDEs) to these neutral states from the $ \tilde X $1A1 state of ScO2−. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2009
Enveloping triangulation method for detecting internal cavities in proteins and algorithm for computing their surface areas and volumes
Authors: Buša Ján , Hayryan Shura , Hu Chin‐Kun , Skřivánek Jaroslav , Wu Ming‐Chya 
Published: July 2008

AbstractDetection and quantitative characterization of the internal cavities in proteins remain an important topic in studying protein structure and function. Here we propose a new analytical method for detecting the existence of cavities in proteins. The method is based on constructing the special enveloping triangulation enclosing the cavities. Based on this method, we develop an algorithm and a fortran package, CAVE, for computing volumes and surface areas of cavities in proteins. We first test our method and algorithm in some artificial systems of spheres and find that the calculated results are consistent with exact results. Then we apply the package to compute volumes and surface areas of cavities for some protein structures in the Protein Data Bank. We compare our calculated results with those obtained by some other methods and find that our approach is reliable. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2009
Force‐field modeling through quantum mechanical calculations: Molecular dynamics simulations of a nematogenic molecule in its condensed phases
Authors: Cacelli Ivo , Lami Carlo Federico , Prampolini Giacomo 
Published: July 2008

AbstractInteraction energy of the 4‐n‐pentyloxy‐4′‐cyanobiphenyl (5OCB) dimer is computed at MP2 level, for many geometrical arrangements using the Fragmentation Reconstruction Method (FRM). DFT calculations are performed for a number of geometries of the monomer. The resulting database is used to parameterize an atomistic intra‐ and inter‐molecular force‐field suitable for classical bulk simulations. Several structural and dynamical properties in 5OCB isotropic and liquid crystalline phases are computed from molecular dynamics simulation mainly in the NPT ensemble. Lengthy runs (more than 70 ns) and large sample sizes (up to 806 molecules) were used to determine the nematic to isotropic transition temperature up to a precision of few K. Good agreement was found in most of the investigated properties, thus validating the accuracy of the proposed model potential, only derived by quantum mechanical calculations. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2009
Møller–Plesset perturbation energies and distances for HeC20 extrapolated to the complete basis set limit
Authors: Varandas A. J. C. 
Published: July 2008

AbstractThe potential energy surface for the C20–He interaction is extrapolated for three representative cuts to the complete basis set limit using second‐order Møller–Plesset perturbation calculations with correlation consistent basis sets up to the doubly augmented variety. The results both with and without counterpoise correction show consistency with each other, supporting that extrapolation without such a correction provides a reliable scheme to elude the basis‐set‐superposition error. Converged attributes are obtained for the C20– He interaction, which are used to predict the fullerene dimer ones. Time requirements show that the method can be drastically more economical than the counterpoise procedure and even competitive with Kohn‐Sham density functional theory for the title system. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2009
Modeling high pressure reactivity in unsaturated systems: Application to dimethylacetylene
Authors: Mediavilla C. , Tortajada J. , Baonza V. G. 
Published: July 2008

AbstractA general model is introduced to study pressure‐induced reactivity on unsaturated systems in the condensed state. The model is applied here to dimethylacetylene (DMA) in the solid phase II (C/2m) because it has been proposed that two DMA molecules can react to form tetramethyl‐cyclobutadiene (TMCBD). The proposed reaction process has been modeled by studying the structural and electronic changes undergone by two DMA molecules as they approach each other preserving the crystal symmetry of phase II. Both monodeterminantal (MP2 and DFT) and multideterminantal (CASSCF and MRMP2) methodologies were used to check the reliability of our model in predicting the reactivity of the system under compression. In all cases, structural results are in agreement with low‐temperature diffraction experiments for the solid phase II. Our model indicates that DMA is expected to form the TMCBD dimer at intermolecular distances close to 2 Å. This value is in excellent agreement with previous calculations on the existence of long carbon–carbon bonds. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2009
Application of semiempirical long‐range dispersion corrections to periodic systems in density functional theory
Authors: Kerber Torsten , Sierka Marek , Sauer Joachim 
Published: July 2008

AbstractEwald summation is used to apply semiempirical long‐range dispersion corrections (Grimme, J Comput Chem 2006, 27, 1787; 2004, 25, 1463) to periodic systems in density functional theory. Using the parameters determined before for molecules and the Perdew‐Burke‐Ernzerhof functional, structure parameters and binding energies for solid methane, graphite, and vanadium pentoxide are determined in close agreement with observed values. For methane, a lattice constant a of 580 pm and a sublimation energy of 11 kJ mol−1 are calculated. For the layered solids graphite and vanadia, the interlayer distances are 320 pm and 450 pm, respectively, whereas the graphite interlayer energy is −5.5 kJ mol−1 per carbon atom and layer. Only when adding the semiempirical dispersion corrections, realistic values are obtained for the energies of adsorption of C4 alkenes in microporous silica (−66 to −73 kJ mol−1) and the adsorption and chemisorption (alkoxide formation) of isobutene on acidic sites in the micropores of zeolite ferrierite (−78 to −94 kJ mol−1). As expected, errors due to missing self‐interaction correction as in the energy for the proton transfer from the acidic site to the alkene forming a carbenium ion are not affected by the dispersion term. The adsorption and reaction energies are compared with the results from Møller‐Plesset second‐order perturbation theory with basis set extrapolation. © 2008 Wiley Periodicals, Inc. J Comput Chem 2008
Acyclic systems of representatives and acyclic colorings of digraphs
Authors: Aharoni Ron , Berger Eli , Kfir Ori 
Published: July 2008

AbstractA natural digraph analog of the graph theoretic concept of “an independent set” is that of “an acyclic set of vertices,” namely a set not spanning a directed cycle. By this token, an analog of the notion of coloring of a graph is that of decomposition of a digraph into acyclic sets. We extend some known results on independent sets and colorings in graphs to acyclic sets and acyclic colorings of digraphs. In particular, we prove bounds on the topological connectivity of the complex of acyclic sets, and using them we prove sufficient conditions for the existence of acyclic systems of representatives of a system of sets of vertices. These bounds generalize a result of Tardos and Szabó. We prove a fractional version of a strong‐acyclic‐coloring conjecture for digraphs. © 2008 Wiley Periodicals, Inc. J Graph Theory 59: 177–189, 2008
On planar intersection graphs with forbidden subgraphs
Authors: Pach János , Sharir Micha 
Published: July 2008

AbstractLet ${\cal C}$ be a family of n compact connected sets in the plane, whose intersection graph $G({\cal C})$ has no complete bipartite subgraph with k vertices in each of its classes. Then $G({\cal C})$ has at most n times a polylogarithmic number of edges, where the exponent of the logarithmic factor depends on k. In the case where ${\cal C}$ consists of convex sets, we improve this bound to O(n log n). If in addition k = 2, the bound can be further improved to O(n). © 2008 Wiley Periodicals, Inc. J Graph Theory 59: 205–214, 2008
Polycyanurate Thermoset Networks with High Thermal, Mechanical, and Hydrolytic Stability Based on Liquid Multifunctional Cyanate Ester Monomers with Bisphenol A and AF Units
Authors: Yameen Basit , Duran Hatice , Best Andreas , Jonas Ulrich , Steinhart Martin , Knoll Wolfgang 
Published: July 2008

AbstractTwo cyanate ester monomers (CEMs) based on oligomeric aryl ether (OAE) derivatives of bisphenol AF and bisphenol A, with multiple reactive cyanate groups, were developed as technologically highly relevant thermosets. These CEMs are liquids processable at room temperature and can be crosslinked by cyclotrimerization of the cyanate groups to form extended polycyanurate (PC) networks at lower temperatures (<265 °C) than many existing CEMs. The cured PCs have high Tgs (>280 °C), with excellent thermal, mechanical, and dielectric properties. PC nanorods with diameters of 65 or 380 nm could be moulded in porous alumina templates from the OAE‐CEMs. The high aspect ratio nanorods with a length in the order of 100 µm were hydrolytically stable upon extended exposure to boiling water.magnified image
Dual Electric Field Induced Alignment of Electrospun Nanofibers
Authors: Acharya Manoranjan , Arumugam Ganesh Kumar , Heiden Patricia A. 
Published: July 2008

AbstractA dual‐field method is described to produce aligned fibers by electrospinning. By applying a secondary electric field perpendicular to the primary field, control over the orientation of the fibers on the collector is obtained. The dual‐field approach is used in conjunction with dual electrodes and a rotating collector. Both approaches were used to electrospin poly(lactic acid) fibers under conditions intended to produce fibers with a diameter greater then 400 nm to aid observation by optical microscopy and digital photography. Digital photography was used to visualize a large area of aligned fiber and image analysis software was used to quantify the degree of alignment. Fibers aligned with the aid of a dual field showed better alignment than those from a single electric field under otherwise identical conditions.magnified image
A new constraint qualification for the formula of the subdifferential of composed convex functions in infinite dimensional spaces
Authors: Boţ Radu Ioan , Grad Sorin‐Mihai , Wanka Gert 
Published: July 2008

AbstractIn this paper we work in separated locally convex spaces where we give equivalent statements for the formulae of the conjugate function of the sum of a convex lower‐semicontinuous function and the precomposition of another convex lower‐semicontinuous function which is also K ‐increasing with a K ‐convex K ‐epi‐closed function, where K is a nonempty closed convex cone. These statements prove to be the weakest constraint qualifications given so far under which the formulae for the subdifferential of the mentioned sum of functions are valid. Then we deliver constraint qualifications inspired from them that guarantee some conjugate duality assertions. Two interesting special cases taken from the literature conclude the paper. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Bi‐commutators of fractional integrals on product spaces
Authors: Chen Wengu , Han Yongsheng , Miao Changxing 
Published: July 2008

AbstractRecently Lacey extended Chanillo's boundedness result of commutators with fractional integrals to a higher parameter setting. In this paper, we extend Lacey's result to higher dimensional spaces by a different method. Our method is in terms of the dual relationship between product BMO and product Hardy space and the maximal function characterization of product Hardy spaces obtained by S.‐Y.Chang and R. Fefferman. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On a generalized dimension of self‐affine fractals
Authors: He Xing‐Gang , Lau Ka‐Sing 
Published: July 2008

AbstractFor ad×dexpanding matrixA, we de.ne a pseudo‐normw(x) in terms ofAand use this pseudo‐norm (instead of the Euclidean norm) to define the Hausdorff measure and the Hausdorff dimension dimwHEfor subsetsEinRd. We show that this new approach gives convenient estimations to the classical Hausdorff dimension dimwHE, and in the case that the eigenvalues ofAhave the same modulus, then dimwHEand dimHEcoincide. This setup is particularly useful to study self‐affine setsTgenerated byϕj(x) =A–1(x+dj),dj∈Rd,j= 1, …,N. We use it to investigate the fractality ofTfor the case that {ϕj}Nj=1satisfying the open set condition as well as the cases without the open set condition. We extend some well‐known results in the self‐similar sets to the self‐af.ne sets. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An exterior boundary value problem in Minkowski space
Authors: López Rafael 
Published: July 2008

AbstractIn three‐dimensional Lorentz–Minkowski space 𝕃3, we consider a spacelike plane Π and a round disc Ω over Π. In this article we seek the shapes of unbounded surfaces whose boundary is ∂ Ω and its mean curvature is a linear function of the distance to Π. These surfaces, called stationary surfaces, are solutions of a variational problem and governed by the Young–Laplace equation. In this sense, they generalize the surfaces with constant mean curvature in 𝕃3. We shall describe all axially symmetric unbounded stationary surfaces with special attention in the case that the surface is asymptotic to Π at the infinity. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Strong convergence of an iterative method for non‐expansive mappings
Authors: Song Yisheng , Chen Rudong 
Published: July 2008

AbstractLet E be a real reflexive Banach space having a weakly continuous duality mapping Jφ with a gauge function φ, and let K be a nonempty closed convex subset of E. Suppose that T is a non‐expansive mapping from K into itself such that F (T) ≠ ∅︁. For an arbitrary initial value x0 ∈ K and fixed anchor u ∈ K, define iteratively a sequence {xn } as follows:
xn +1 = αn u + βn xn + γn Txn , n ≥ 0,
where {αn }, {βn }, {γn } ⊂ (0, 1) satisfies αn +βn + γn = 1, (C 1) limn →∞ αn = 0, (C 2) ∑∞n =1 αn = ∞ and (B) 0 < lim infn →∞ βn ≤ lim supn →∞ βn < 1. We prove that {xn } converges strongly to Pu as n → ∞, where P is the unique sunny non‐expansive retraction of K onto F (T). We also prove that the same conclusions still hold in a uniformly convex Banach space with a uniformly Gâteaux differentiable norm or in a uniformly smooth Banach space. Our results extend and improve the corresponding ones by C. E. Chidume and C. O. Chidume [Iterative approximation of fixed points of non‐expansive mappings, J. Math. Anal. Appl. 318, 288–295 (2006)], and develop and complement Theorem 1 of T. H. Kim and H. K. Xu [Strong convergence of modified Mann iterations, Nonlinear Anal. 61, 51–60 (2005)]. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Gauges for the self‐similar sets
Authors: Wen Sheng‐You , Wen Zhi‐Xiong , Wen Zhi‐Ying 
Published: July 2008

AbstractFor a self‐similar set E with the open set condition we completely determine the class of its Hausdorff gauges and the class of its prepacking gauges. Moreover, its Hausdorff measures and its packing premeasures with respect to the corresponding gauges are estimated. Without the open set condition we prove that a doubling gauge function is a packing gauge of E if and only if it is a prepacking gauge of E. Also, we give some extensions and applications of these results. Here a gauge function is called a Hausdorff, a prepacking, and a packing gauge of a set, if with respect to the function the set has positive and finite Hausdorff measure, packing premeasure, and packing measure, respectively. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Some remarks on essential self‐adjointness and ultracontractivity of a class of singular elliptic operators
Authors: Pang Michael M. H. 
Published: July 2008

AbstractWe study the properties of essential self‐adjointness on C∞c (ℝN ) and semigroup ultracontractivity of a class of singular second order elliptic operators
equation image
defined in L2 (ℝN , σ–a –N (x) dx) with Dirichlet boundary conditions, where a, b ∈ ℝ and σ: ℝN → (0, ∞) is a C∞‐function satisfying
c‐1(1 + |x |) ≤ σ (x) ≤ c (1 + |x |) (x ∈ ℝN).
We also obtain sharp short time upper and lower diagonal bounds on the heat kernel of e –Ht. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Functionalization of Crosslinked Vesicles by Co‐Self‐Assembly of a Gelable Diblock Copolymer and Mercaptosilane
Authors: Xiong Ming , Chen Yongming , Maskos Michael 
Published: July 2008

AbstractHerein, a convenient and general method to simultaneously fix and functionalize polymeric vesicles with sulphydryl groups by the co‐self‐assembly of poly(ethylene oxide)‐block‐poly[3‐(triethoxysilyl)propyl methacrylate] (PEO‐b‐PTESPMA) and 3‐mercaptopropyltrialkoxysilane in an aqueous solution is reported. The presence of sulphydryl groups across the vesicle membrane has been confirmed by using an energy‐filtered technique during TEM analysis and by capturing Au nanoparticles.magnified image
Inorganic–organic hybrid alginate beads with LCST near human body temperature for sustained dual‐sensitive drug delivery
Authors: Shi Jun , Liu Lihua , Liu Xiaopei , Sun Ximeng , Cao Shaokui 
Published: July 2008

AbstractIn order to obtain dual‐stimuli‐responsive (temperature/pH) alginate beads that exhibit LCST close to human body temperature for sustained drug release applications, poly (NIPAAm‐co‐AAm) hydrogel (with LCST 37.5°C) were selected and associated with calcium alginate to prepare inorganic–organic hybrid biomineralized polysaccharide alginate beads via a one‐step method in this paper. Scanning electron microscopy (SEM) and energy dispersive X‐ray spectrometer (EDS) results demonstrated that calcium phosphate could not only be found in the surface but also in the cross‐section of biomineralized polysaccharide beads. Both equilibrium swelling and indomethacin release behavior were found to be pH‐ and thermo‐responsive. In addition, indomethacin release profile could be sustained with a inorganic–organic hybrid membrane: the release amount reached 96% within 4 hr for the unmineralized beads, while a drug release of only 64% obtained after subjecting the biomineralized polysaccharide beads to the same treatment. These results indicate that the biomineralized polysaccharide membrane could prevent the permeability of the encapsulated drug and reduce the drug release rate effectively. The studied system has the potential to be used as an effective smart sustainable delivery system for biomedical applications. Copyright © 2008 John Wiley & Sons, Ltd.