bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and evaluation of collagen–chitosan–hydroxyapatite nanocomposites for bone grafting
Authors: Wang Xiaoliang , Wang Xiaomin , Tan Yanfei , Zhang Bo , Gu Zhongwei , Li Xudong 
Published: May 2008

AbstractIncorporation of hydroxyapatite (HA) into the matrix of collagen (Col) and chitosan (Chi) by in situ synthesis was introduced to prepare nanocomposites. Structural investigations of the pure Col–Chi mixture validated the influence of Chi on Col assembly, but the molecular interactions between Col and Chi was partially depressed during the intervention of in situ HA synthesis, as revealed by FTIR and DSC analyses. A series of Col–Chi–HA (CCHA) nanocomposites with varying HA content were thereby prepared by a sequential method, involving in situ synthesis in the Col–Chi system, then gelling at 25°C and subsequently washing the resultant elastic gel followed by dehydration consolidation. The structural characteristics and biological properties of the dehydrated CCHA nanocomposites were further evaluated by using XRD, FTIR, TG, and SEM analyses and the osteoblast culture experiment. Formation of a well integrated microstructure of organic fibers (ca. 90 nm in size) and dense matrix including inorganic aggregates (less than 30 nm in size) was found in these nanocomposites. Rat Ros 17/2.8 Osteoblasts proliferated and attached well on the surface of both CCHA nanocomposite and Col–Chi mixture. These results indicated that in situ HA synthesis in the Col–Chi system provided a feasible route for bone grafting nanocomposites. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Improvement in molecule exchange efficiency in Gibbs ensemble Monte Carlo: Development and implementation of the continuous fractional component move
Authors: Shi Wei , Maginn Edward J. 
Published: May 2008

AbstractThe continuous fractional component Monte Carlo (CFC MC) move (J Chem Theory Comput, 2007, 3, 1451) is extended to the Gibbs ensemble. The algorithm is validated against conventional simulations for the Lennard Jones fluid and a flexible water model. The method is also used to compute the vapor‐liquid coexistence densities of a model for SO2. The CFC molecule exchange move relies on the gradual insertion and deletion of molecules in conjunction with a self‐adapting bias potential. As a result, the method does not require the formation of spontaneous voids in the dense fluid phase to be successful, leading to molecule exchange acceptance probabilities that are nearly independent of temperature. For example, over 1% of the vapor‐liquid molecule exchange moves are successful for water at 280 K, whereas advanced rotational and configurational bias methods have success rates of less than 0.03%. The CFC move can be combined with other Monte Carlo moves to enable efficient simulation of dense strongly associating fluids that are to this point infeasible to model with standard methods. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2008
Interactions between the L1 cell adhesion molecule and ezrin support traction‐force generation and can be regulated by tyrosine phosphorylation
Authors: Sakurai Takeshi , Gil Orlando D. , Whittard John D. , Gazdoiu Mihaela , Joseph Todd , Wu James , Waksman Adam , Benson Deanna L. , Salton Stephen R. , Felsenfeld Dan P. 
Published: May 2008

AbstractAn Ig superfamily cell‐adhesion molecule, L1, forms an adhesion complex at the cell membrane containing both signaling molecules and cytoskeletal proteins. This complex mediates the transduction of extracellular signals and generates actin‐mediated traction forces, both of which support axon outgrowth. The L1 cytoplasmic region binds ezrin, an adapter protein that interacts with the actin cytoskeleton. In this study, we analyzed L1–ezrin interactions in detail, assessed their role in generating traction forces by L1, and identified potential regulatory mechanisms controlling ezrin–L1 interactions. The FERM domain of ezrin binds to the juxtamembrane region of L1, demonstrated by yeast two‐hybrid interaction traps and protein binding analyses in vitro. A lysine‐to‐leucine substitution in this domain of L1 (K1147L) shows reduced binding to the ezrin FERM domain. Additionally, in ND7 cells, the K1147L mutation inhibits retrograde movement of L1 on the cell surface that has been linked to the generation of the traction forces necessary for axon growth. A membrane‐permeable peptide consisting of the juxtamembrane region of L1 that can disrupt endogenous L1–ezrin interactions inhibits neurite extension of cerebellar cells on L1 substrates. Moreover, the L1–ezrin interactions can be modulated by tyrosine phosphorylation of the L1 cytoplasmic region, namely, Y1151, possibly through Src‐family kinases. Replacement of this tyrosine together with Y1176 with either aspartate or phenylalanine changes ezrin binding and alters colocalization with ezrin in ND7 cells. Collectively, these data suggest that L1–ezrin interactions mediated by the L1 juxtamembrane region are involved in traction‐force generation and can be regulated by the phosphorylation of L1. © 2008 Wiley‐Liss, Inc.
Caveat emptor, caveat venditor: buyers and sellers beware the tender trap
Authors: Harris Ian , Mainelli Michael , Jones Haydn 
Published: May 2008

Abstract

Suppliers increasingly find themselves required to put in competitive tenders in order to win business, especially public sector contracts. Indeed, large organizations of all kinds, including NGOs, increasingly require their suppliers to go through structured tendering processes. But often those structured tendering processes are inappropriate for the procurement situation, leading to non‐optimal results for both buyers and sellers.

Copyright © 2008 John Wiley & Sons, Ltd.
Strategic knowledge management: creating comparative advantages
Authors: Kasper Helmut , Mühlbacher Jürgen , Müller Barbara 
Published: May 2008

Abstract

Knowledge management can be seen as an important precondition to build dynamic capabilities and comparative advantages (Teece et al., 1997). In this article we look at the interdependencies among knowledge management, the market segment chosen, and the strategy of multinational companies.

Based on the theoretical literature about dynamic capabilities and competition, we will build a model on the relationship of knowledge management and strategic management. We support the theoretical results with the findings of four cases involving multinational companies.

We differentiate among four settings of knowledge management and corporate strategy, depending on the dynamics of the market (external focus), the rate of innovation (internal focus), and the dominant kind of knowledge used in an industry.

Copyright © 2008 John Wiley & Sons, Ltd.
Drop test simulation of a sample tomato with finite element method
Authors: Kabas Onder , Celik H Kursat , Ozmerzi Aziz , Akinci İbrahin 
Published: May 2008

AbstractBACKGROUND: The aim of this study was to investigate deformation behaviour of a biological material upon crashing. The 50 samples for the study were randomly selected from harvested tomatoes.RESULT: Mechanical parameters were obtained by a compression test of the chosen cherry tomato samples. The behaviour of the drop characteristics of cherry tomato was investigated using finite element simulation, and deformation characteristics were determined by a combination of the finite element results and measured data. A comparison between experimental data and finite element simulation shows that the two sets of results agree well.CONCLUSION: The results of this study provide the foundation for further investigations of the mechanical parameters of fruits and vegetables by using finite element simulations. Copyright © 2008 Society of Chemical Industry
Explicit analytical solutions of the generalized Burger and Burger–Fisher equations by homotopy perturbation method
Authors: Rashidi M.M. , Ganji D.D. , Dinarvand S. 
Published: May 2008

AbstractIn this article, we apply the homotopy perturbation method (HPM) to obtain approximate analytical solutions of the generalized Burger and Burger‐Fisher (B–F) equations. Several numerical examples are given to illustrate the efficiency of the HPM. Comparison of the result obtained by the present method with exact solution reveals that the accuracy and fast convergence of the new method. It is predicted that the HPM can be found wide application in engineering problems. © 2008 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2009
Improved Schwarz methods for an elliptic problem in a nonconvex domain with discontinuous coefficients
Authors: Chniti Chokri 
Published: May 2008

AbstractA matching of singularities in domain decomposition methods with angular domains has been introduced in (Chniti et al., CRAS 342 (2006), 883‐886; Chniti et al., to appear) with the model operator ‐ Δ. This article verifies that the same approach is appropriate for other second order elliptic operators ‐ div(a∇) with a variable coefficient a= a(θ) which is discontinuous with respect to the angular variable θ. © 2008 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2009
The cross‐cultural adaptation of the disability of arm, shoulder and hand (DASH): a systematic review
Authors: Alotaibi Naser M. 
Published: May 2008

AbstractA systematic review of cross‐cultural adaptations of the Disability of Arm, Shoulder and Hand into other languages was undertaken focusing on the translation and adaptation process, the problems during the translation process and proposed solutions. Nine articles were selected for analysis. All were written in English and addressed the qualitative issues of the cross‐cultural adaptation process. The results demonstrated strong evidence that translation, adaptation and technical issues are most influential in the cross‐cultural adaptation process. Awareness, understanding and incorporation of these issues will assist in future translations and adaptations of occupational therapy evaluation tools for use in other countries with different cultures. Implications for occupational therapy education, practice and research are discussed. Copyright © 2008 John Wiley & Sons, Ltd.
Number of genomic imbalances correlates with the overall survival for adrenocortical cancer in childhood
Authors: Loncarevic Ivan F. , Hering Antje , Posorski Nicole , Linden Tobias , Hoyer Heike , Bucsky Peter 
Published: May 2008

AbstractBackgroundAdrenocortical tumours (ACT) in children are rare and, if malignant, often associated with poor prognosis. Relevant cytogenetic factors for prognosis are hardly available.ProceduresWe analysed 14 adrenocortical cancers (ACC) of children by comparative genomic hybridisation (CGH).ResultsThe total number of genomic imbalances ranged from 1 to 17 in individual tumour samples. The most common imbalances were +1q (57%), +12p (50%), +12q (50%), +1p (43%), +7q (42%), +9q (42%), +15q (42%), and −4q (57%), −11q (57%), −4p (42%), and −16q (42%). The median number of genomic changes was 5.5 (n = 8) in pT1–pT2 and 15.5 (n = 6) in pT3‐pT4 tumours. The median number was 4 in the eight patients, who remain in remission more than 51 months and 15.5 in the six patients, who have died from the disease within 44 months. Moreover, all seven patients with less than 10 individual imbalances were in remission (median follow‐up 72 months), while all but one patient with 10 and more individual imbalances (n = 7) have died from the disease (median survival time 30 months). Comparison of the data from children and adults revealed characteristic differences. Gain of 1p and loss of 4p, 4q and 16q are frequent in childhood and rare in adults. Inversely, loss of 1p is rare in childhood but frequent in adult ACT.ConclusionThe number of CGH imbalances appeared to have a predictive value for overall survival in paediatric ACC. Pediatr Blood Cancer 2008;51:356–362. © 2008 Wiley‐Liss, Inc.
Management of retinoblastoma with proximal optic nerve enhancement on MRI at diagnosis
Authors: Armenian Saro H. , Panigrahy Ashok , Murphree A. Linn , Jubran Rima F. 
Published: May 2008

AbstractBackgroundIn North America, retinoblastoma rarely presents with gross clinical evidence of tumor involving the optic nerve. Extent of microscopic tumor infiltration into the postlaminar optic nerve is a significant risk factor for metastasis, especially if there is tumor at the cut end. Due to poor outcomes in patients with metastatic disease, historical treatment for patients with clinical evidence of extraocular optic nerve involvement has included upfront enucleation followed by aggressive adjuvant chemotherapy. Additional orbital irradiation is advocated for individuals with optic nerve involvement at the surgical margin. Little is known about the role of neoadjuvant therapy in the setting of orbital optic nerve enhancement on magnetic resonance imaging (MRI) at diagnosis.MethodsA retrospective review of consecutive retinoblastoma cases at Childrens Hospital Los Angeles over a 3‐year period (2004–2006) found to have gadolinium contrast enhancement in the proximal portion of optic nerve on MRI at diagnosis.ResultsNine patients fit the inclusion criteria. Two had secondary glaucoma of a sufficient degree to cause an enlarged eye (buphthalmos). Median age at presentation was 17 months (2–36 months). All patients received neoadjuvant chemotherapy prior to enucleation. Only two received external beam radiation. All are disease‐free with a median follow‐up of 22 months (12–41 months).ConclusionsNeoadjuvant chemotherapy is well tolerated prior to enucleation of retinoblastoma‐containing eyes associated with contrast enhancement of the proximal optic nerve on MRI at diagnosis. Such an approach may be used to decrease intensity or duration of chemotherapy and need for external beam radiation. Pediatr Blood Cancer 2008;51:479–484. © 2008 Wiley‐Liss, Inc.
MRI abnormalities of the brain in one‐year‐old children with sickle cell anemia
Authors: Wang Winfred C. , Pavlakis Steven G. , Helton Kathleen J. , McKinstry Robert C. , Casella James F. , Adams Robert J. , Rees Renee C. 
Published: May 2008

AbstractBackgroundSickle cell anemia (SCA) frequently results in damage to the central nervous system (CNS), but the age of onset of these effects is uncertain. We performed MRI examinations of the brain in infants with SCA, who were evaluated as part of the multicenter randomized double‐blinded Pediatric Hydroxyurea Phase III Clinical Trial (BABY HUG).MethodsDetermination of eligibility for enrollment in the trial originally required baseline MRI and magnetic resonance angiography (MRA) of the brain. A standardized imaging protocol was utilized across eight clinical centers. MRI/MRA exams were reviewed by a panel of three neurology/neuroradiology readers and interpretations reported to the coordinating center. Results were correlated with patient age, gender, history, WBC count, platelet count, hemoglobin (Hb), HbF level, score on the Bayley Scales of Infant Development, and velocity on transcranial Doppler ultrasonography (TCD).ResultsTwenty‐three subjects with HbSS were examined at average age 13.7 months (range 10–18 months); 13 were male. Three (13%, CI: 3–34%) had silent infarcts on MRI, two in the right frontal area and one bilaterally. None had MRA abnormalities. The lesions were correlated with increased right‐sided TCD velocity and low HbF level, but not with age, history, Hb level, developmental score, or left‐sided velocity.ConclusionsSilent brain infarcts occur in a small but significant number of infants with SCA as early as a year of age. This finding indicates a need for thorough evaluation of the CNS very early in life in children with SCA in order to develop timely intervention strategies. Pediatr Blood Cancer 2008;51:643–646. © 2008 Wiley‐Liss, Inc.
A novel type of optically active helical polymers: Synthesis and characterization of poly(N‐propargylureas)
Authors: Deng Jianping , Luo Xiaofeng , Zhao Weiguo , Yang Wantai 
Published: May 2008

AbstractThis article presents two novel artificial helical polymers, substituted polyacetylenes with urea groups in side chains. Poly(4) and poly(5) can be obtained in high yields (≥97%) and with moderate molecular weights (11,000–14,000). Poly(4) contains chiral centers in side chains, and poly(5) is an achiral polymer. Both of the two polymers adopted helical structures under certain conditions. More interestingly, poly(4) exhibited large specific optical rotations, resulting from the predominant one‐handed screw sense. The helical conformation in poly(5) was stable against heat, while poly(4) underwent conformational transition from helix to random coil upon increasing temperature from 0 to 55 °C. Solvents had considerable influence on the stability of the helical conformation in poly(4). The screw sense adopted by the helices was also largely affected by the nature of the solvent. Poly(4‐co‐5)s formed helical conformation and showed large optical rotations, following the Sergeants and Soldiers rule. By comparing the present two polymers (with one NH groups) with the three polymers previously reported (with two NH groups in side chains), the nature of the hydrogen bonds formed between the neighboring urea groups played big roles in the formation of stable helical conformation. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4112–4121, 2008
Synthesis of a new organogelator based on block structures of co‐oligoamide‐6
Authors: Thuillez J. , Thouraud F. , Fleury E. 
Published: May 2008

AbstractA series of new bisurea derivatives having in common two co‐oligoamide arms have been synthesized and characterized by NMR, SEC, DSC, SEM, and optical microscopy. These compounds are only soluble at high temperature in aprotic polar solvent. By cooling the solutions, gelation occurs if the concentration of these bisurea derivatives is higher than 3% (w/w). Comparisons with derivatives devoid of oligoamide arms leading no gelation suggest that two kinds of interaction are necessary to get the self‐assembling, namely intermolecular hydrogen‐bonding between urea groups and between oligoamide arms. As these interactions induce interconnections in several directions, the possibility of building the long classical fibrous structures is limited. Accordingly, the ultrastructure of the gel consists only of short interconnected fibers. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4122–4129, 2008
Novel temperature‐ and pH‐responsive graft copolymers composed of poly(L‐glutamic acid) and poly(N‐isopropylacrylamide)
Authors: He Chaoliang , Zhao Changwen , Guo Xinhua , Guo Zhaojun , Chen Xuesi , Zhuang Xiuli , Liu Shuying , Jing Xiabin 
Published: May 2008

AbstractA series of novel temperature‐ and pH‐responsive graft copolymers, poly(L‐glutamic acid)‐g‐poly(N‐isopropylacrylamide), were synthesized by coupling amino‐semitelechelic poly(N‐isopropylacrylamide) with N‐hydroxysuccinimide‐activated poly(L‐glutamic acid). The graft copolymers and their precursors were characterized, by ESI‐FTICR Mass Spectrum, intrinsic viscosity measurements and proton nuclear magnetic resonance (1H NMR). The phase‐transition and aggregation behaviors of the graft copolymers in aqueous solutions were investigated by the turbidity measurements and dynamic laser scattering. The solution behavior of the copolymers showed dependence on both temperature and pH. The cloud point (CP) of the copolymer solution at pH 5.0–7.4 was slightly higher than that of the solution of the PNIPAM homopolymer because of the hydrophilic nature of the poly(glutamic acid) (PGA) backbone. The CP markedly decreased when the pH was lowered from 5 to 4.2, caused by the decrease in hydrophilicity of the PGA backbone. At a temperature above the lower critical solution temperature of the PNIPAM chain, the copolymers formed amphiphilic core‐shell aggregates at pH 4.5–7.4 and the particle size was reduced with decreasing pH. In contrast, larger hydrophobic aggregates were formed at pH 4.2. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4140–4150, 2008
Properties of ZnO(0001) layers grown by metalorganic chemical vapor deposition on GaN(0001) templates
Authors: Ive T. , Ben‐Yaacov T. , Asamizu H. , Van de Walle C. G. , Mishra U. , DenBaars S. P. , Speck J. S. 
Published: May 2008

AbstractThe cover picture of this issue of physica status solidi (c) has been taken from the article [1].
Komplexe Dachformen und ihre Anforderungen an die Unterkonstruktion
Authors: Fick Karlfriedrich , Ramich Alexander , Thiebes Robert 
Published: May 2008

AbstractIn den letzten zwei Dekaden sind die gestalterischen Anforderungen an die Formen von Dächern aus rollgeformten Aluminium‐Profiltafeln stark gestiegen, von einfachen Rechteckformen, über konvex oder konkav gerundete und konisch geschnittene, zu planmäßig ausgebauchten oder eingeschnürten Tafeln für Gebäudehüllen in Ellipsen‐ oder Hyperbelform. Mittels neuer Rollformtechniken können mittlerweile Profiltafeln hergestellt werden, die keine Symmetrie bezüglich ihrer Längsachse mehr aufweisen, sondern, eingeschnürt und ausgebaucht, in der Fläche ihres breiten Gurtes verschwenkt und dazu noch gebogen sein können.An zwei spektakulären Bauausführen der letzten Jahre wird gezeigt, welch immenser Aufwand in Vorbereitung und Ausführung – von der Tragwerks‐ bis zur Verlegeplanung und von der Unterkonstruktion mit ihrer Vermessung bis zur eigentlichen Dachdeckung – getrieben werden muss, um derart räumlich verformte Profiltafeln zu konstruieren, herzustellen und zu verarbeiten, damit die Anforderungen des Bauherrn und Planers an die sthetik und die Funktion der Aluminium‐Profiltafeln, und die damit gestaltete Gebäudehülle, erfüllt werden können.
Durchknöpftragfähigkeit der Befestigungsmittel von Sandwichelementen bei direkter Befestigung
Authors: Misiek Thomas , Saal Helmut , Kathage Karsten 
Published: May 2008

AbstractVergleichende Untersuchungen zu den unterschiedlichen in Europa angewendeten Prüfverfahren zur Ermittlung der Durchknöpftragfähigkeit der Verbindungen von Sandwichelementen ließen ein Sicherheitsdefizit bei den in Deutschland üblichen Versuchen mit Bügelproben vermuten. Im Rahmen eines durch das Deutsche Institut für Bautechnik geförderten Forschungsprojektes konnte diese Vermutung zumindest teilweise entkräftet werden.