bluuebunny/crossref_metadata_2025 huggingface dataset:
Probing the Hydrophobic Pocket of the Active Site in the Particulate Methane Monooxygenase (pMMO) from Methylococcus capsulatus (Bath) by Variable Stereoselective Alkane Hydroxylation and Olefin Epoxidation
Authors: Ng Kok‐Yaoh , Tu Li‐Chun , Wang Yane‐Shih , Chan Sunney I. , Yu Steve S.‐F.
Published: March 2008

pMMO from M. capsulatus (Bath) oxidizes straight‐chain C1–C5 alkanes and alkenes to form their corresponding 2‐alcohols and epoxides. According to experiments performed with cryptically chiral ethane and D,L‐[2‐2H1,3‐2H1]butane, the reactions proceed through the concerted O‐atom insertion mechanism. However, when propene and but‐1‐ene are used as epoxidation substrates, the enantiomeric excesses (ees) of the enzymatic products are only 18 and 37 %, respectively. This relatively poor stereoselectivity in the enzymatic epoxidation presumably reflects low stereochemical differentiation between the re and si faces in the hydrophobic pocket of the active site. Further insights into the reaction mechanism are now provided by studies on trans‐but‐2‐ene, which reveal only the D,L‐2,3‐dimethyloxirane products, and on cis‐but‐2‐ene, which yield only the meso product. These observations indicate that the enzymatic epoxidation indeed proceeds through electrophilic syn addition. To achieve better facial selectivity, we have also used 3,3,3‐trifluoroprop‐1‐ene as the substrate. The products obtained are 90 % (2S)‐oxirane. When 1,1,1‐trifluoropropane is the substrate, the hydroxylation at the 2‐carbon exhibits an inverse chiral selectivity relative to that seen with normal butane, if we consider the size of the CF3 group in the fluorinated propane to be comparable to one of the ethyl groups in butane. These experiments are beginning to delineate the factors that influence the orientations of various substrates in the hydrophobic cavity of the active site in the enzyme.
Dynorphin and stress‐related peptides in rat locus coeruleus: Contribution of amygdalar efferents
Authors: Reyes B.A.S. , Drolet G. , Van Bockstaele E.J.
Published: March 2008

The interaction between the stress axis and endogenous opioid systems has gained substantial attention, because it is increasingly recognized that stress alters individual sensitivity to opiates. One site at which opiates and stress substrates may interact to have global effects on behavior is within the locus coeruleus (LC). We have previously described interactions of several opioid peptides [e.g., proopiomelanocortin, enkephalin (ENK)] with the stress‐related peptide corticotropin‐releasing factor (CRF) in the LC. To examine further the interactions among dynorphin (DYN), ENK, and CRF in the LC, sections were processed for detection of DYN and CRF or DYN and ENK in rat brain. DYN‐ and CRF‐containing axon terminals overlapped noradrenergic dendrites in this region. Dual immunoelectron microscopy showed coexistence of DYN and CRF; 35% of axon terminals containing DYN were also immunoreactive for CRF. In contrast, few axon terminals contained both DYN and ENK. A potential DYN/CRF afferent is the central nucleus of the amygdala (CeA). Dual in situ hybridization showed that, in CeA neurons, 31% of DYN mRNA‐positive cells colocalized with CRF mRNA, whereas 53% of CRF mRNA‐containing cells colocalized with DYN mRNA. Finally, to determine whether limbic DYN afferents target the LC, the CeA was electrolytically lesioned. Light‐level densitometry of DYN labeling in the LC showed a significant decrease in immunoreactivity on the side of the lesion. Taken together, these data indicate that DYN‐ and CRF‐labeled axon terminals, most likely arising from amygdalar sources, are positioned dually to affect LC function, whereas DYN and ENK function in parallel. J. Comp. Neurol. 508:663–675, 2008. © 2008 Wiley‐Liss, Inc.
The Antimalarial Artemisone is an Efficient Heme Alkylating Agent
Authors: Bousejra‐El Garah Fatima , Meunier Bernard , Robert Anne
Published: March 2008

The reductive activation by iron(II)‐heme of artemisone, a C‐10 substituted derivative of the antimalarial artemisinin, generates covalent heme‐drug adducts in high yields. This result confirms that the substitution at C‐10 of artemisinin does not alter the alkylating ability of artemisinin derivatives when activated by a redox‐active metal center. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Loss prediction in switched reluctance motors using finite element method
Authors: Faiz J. , Ganji B. , Carstensen C. E. , De Doncker R. W.
Published: March 2008

In the present paper, a core loss model for switched reluctance motor (SRM) is developed using ANSYS finite element package. In this model, the flux waveform in one part of the magnetic circuit of the motor is predicted by analysis of the motor with finite element method (FEM), and then the flux waveforms in other sections of the motor are determined using this predicted flux waveform. To validate the obtained flux waveforms, they are compared with those predicted solely by analysis of the motor with FEM. Since the flux waveforms are completely non‐sinusoidal, three different methods based on the Steinmetz equation are utilized to estimate the core loss, and the estimated loss are compared with measured data. For the measurement, an experimental set‐up is introduced and various aspects of the core loss measurement of SRM are discussed. Copyright © 2008 John Wiley & Sons, Ltd.
A BAC transgenic mouse model to analyze the function of astroglial SPARCL1 (SC1) in the central nervous system
Authors: Weimer Jill M. , Stanco Amelia , Cheng Jr‐Gang , Vargo Ana C. , Voora Santhi , Anton E. S.
Published: March 2008

Extracellular matrix associated Sparc‐like 1 (SC1/SPARCL1) can influence the function of astroglial cells in the developing and mature central nervous system (CNS). To examine SC1's significance in the CNS, we generated a BAC transgenic mouse model in which Sc1 is expressed in radial glia and their astrocyte derivatives using the astroglial‐specific Blbp (Brain‐lipid binding protein; [Feng et al., (1994) Neuron 12:895–908]) regulatory elements. Characterization of these Blbf‐Sc1 transgenic mice show elevated Sc1 transcript and protein in an astroglial selective pattern throughout the CNS. This model provides a novel in vivo system for evaluating the role of SC1 in brain development and function, in general, and for understanding SC1's significance in the fate and function of astroglial cells, in particular. © 2008 Wiley‐Liss, Inc.
Monitoring of FLT3 phosphorylation status and its response to drugs by flow cytometry in AML blast cells
Authors: Grafone Tiziana , Palmisano Michela , Nicci Chiara , Martelli Alberto Maria , Emanuela Ottaviani , Storti Sergio , Baccarani Michele , Martinelli Giovanni
Published: March 2008

FLT3 mutation and overexpression in most acute myeloid leukaemia (AML) patients make this tyrosine kinase receptor an attractive therapeutic target. FLT3 kinase inhibitors are actually in clinical trials, thus it is critical to develop a reproducible and standardized method for screening of FLT3 activation and for monitoring its inhibition in response to drug in AML patients. We developed a flow cytometry method to analyse phosphorylated FLT3 (P‐FLT3) in samples with <105 cells. The method was first validated in FLT3 wild‐type (HL60/WT) and mutant (MV4‐11/ITD+) as well as FLT3 negative (K562) cell lines. The method also proved to be reproducible in AML patient samples. Analysis was performed after exposure to drugs (CEP‐701 and SU11657), in vitro and in vivo. In response to increasing drug concentrations, there was a linear reduction in P‐FLT3. Intracellular flow cytometry analysis correlated with Western blot and XTT assays; flow cytometry data also correlated with FLT3 mutational status. The results highlight a rapid method to detect P‐FLT3 protein at the single cell level by flow cytometry which enables an accurate assessment of FLT3 kinase activity in blast cells in response to novel tyrosine kinase inhibitors. Copyright © 2008 John Wiley & Sons, Ltd.
Long‐term evaluation of a calcium phosphate bone cement with carboxymethyl cellulose in a vertebral defect model
Authors: Kobayashi Hideo , Fujishiro Takaaki , Belkoff Stephen M. , Kobayashi Naomi , Turner A. Simon , Seim Howard B. , Zitelli Joseph , Hawkins Monica , Bauer Thomas W.
Published: March 2008

We investigated histological and compressive properties of a calcium phosphate bone cement (BoneSource® (CPC); Stryker Orthopaedics, Mahwah, New Jersey) plus carboxymethyl cellulose (CMC) using a sheep vertebral bone void model. Bone voids were surgically created in L3 and L5 in each of 40 sheep, and the voids were filled with the cement. Histological and radiographic evaluations were performed on one vertebral body from each animal at either: 0, 3, 6, 12, 24, or 36 months after surgery; mechanical testing was performed on operated and non‐operated vertebral bodies from 35 sheep. Undecalcified sections were digitized, and the area of the original defect, new bone formation, empty space, fibrous tissue, and residual cement were quantified with histomorphometry. Decalcified sections were evaluated qualitatively. The cement was biocompatible, extremely osteoconductive and underwent steady resorption and replacement by bone and bone marrow. Histomorphometry showed variations in the rate of cement remodeling among animals in each time group, but on average, at 36 months the original defect area was occupied by ∼14% bone, 82% cement, and 4% bone marrow. Even in animals that had greater resorption of cement, there was good bone ingrowth with no fibrous tissue. Compressive testing did not reveal a significant difference in the mechanical properties between vertebral bodies augmented with cement and non‐augmented controls, irrespective of the postoperative time. BoneSource mixed with CMC had adequate osteoconductivity, biocompatibility, and adequate compressive strength. There was variability among animals, but histology suggests that considerable cement was still present in most samples after 36 months. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Do crocodilians get the flu? Looking for influenza A in captive crocodilians
Authors: Davis Lisa Marie , Spackman Erica
Published: March 2008

It is well established that several wild aquatic bird species serve as reservoirs for the influenza A virus. It has also been shown that the influenza A virus can be transmitted to mammalian species such as tigers and domestic cats and dogs through ingestion of infected birds. Another group of animals that should also be considered as potential hosts for the influenza A virus are the crocodilians. Many crocodilian species share aquatic environments with wild birds that are known to harbor influenza viruses. In addition, many large crocodilians utilize birds as a significant food source. Given these factors in addition to the close taxonomic proximity of aves to the crocodilians, it is feasible to ask whether crocodilian species may also harbor the influenza A virus. Here we analyzed 37 captive crocodilians from two locations in Florida (plus 5 wild bird fecal‐samples from their habitat) to detect the presence of influenza A virus. Several sample types were examined. Real‐time RT‐PCR tests targeting the influenza A matrix gene were positive for four individual crocodilians—Alligator sinensis, Paleosuchus trigonatus, Caiman latirostris and Crocodylus niloticus. Of the seven serum samples tested with the avian influenza virus agar gel immunodiffusion assay, three showed a nonspecific reaction to the avian influenza virus antigen—A. sinensis, P. trigonatus and C. niloticus (C. latirostris was not tested). Viable virus could not be recovered from RT‐PCR‐positive samples, although this is consistent with previous attempts at viral isolation in embryonated chicken eggs with crocodilian viruses. J. Exp. Zool. 309A:571–580, 2008. © 2008 Wiley‐Liss, Inc.
The daguerreotype surface as a SERS substrate: characterization of image deterioration in plates from the 19th century studio of Southworth & Hawes
Authors: Centeno Silvia A. , Meller Taina , Kennedy Nora , Wypyski Mark
Published: March 2008

Dramatic condition changes were noted in a group of daguerreotypes during a 10 month‐long exhibition featuring masterworks of the prominent Boston‐based studio of Southworth & Hawes. The changes took the form of a hazy, extended white surface layer and of white spots that partially obscured the images after between four weeks and 10 months of exhibition. Raman spectroscopy, complemented by in situ scanning electron microscopy–energy dispersive X‐ray spectrometry (SEM–EDS), was used to nondestructively characterize this form of image deterioration in eight representative daguerreotypes from the studio. Raman proved to be a sensitive technique to noninvasively identify the compounds on the plates due to the fact that their Ag surfaces behave as surface‐enhanced Raman scattering (SERS) substrates. A band at ca 242 cm−1 assigned to the AgCl stretching mode was observed in the areas where a white surface layer or white spots are present. In some of the areas probed, substituted aromatic compounds were also detected. The presence of AgCl bonds on daguerreotype surfaces has profound implications for their exhibition and preservation due to the photosensitivity of silver chloride in the ultraviolet–visible range, which can generate metallic silver that would redeposit on the surfaces. The possible sources of the compounds detected on the surfaces of the plates are discussed. Copyright © 2008 John Wiley & Sons, Ltd.
Evaluation of three different mobile Raman microscopes employed to study deteriorated civil building stones
Authors: Martínez‐Arkarazo I. , Smith D. C. , Zuloaga O. , Olazabal M. A. , Madariaga J. M.
Published: March 2008

Three different Raman spectrometers were used to analyse the original composition and the degradation products formed on natural outcrops and building materials under influences of urban and industrial pollutants and a marine environment. A Renishaw portable Raman instrument was used to check the efficiency of two ultramobile instruments for the identification of the products of decay of diverse carbonaceous stones taken from three areas located at different distances from the coast. Satisfactory results were obtained in measurements of original compounds such as quartz and calcium carbonate. Differentiation between the polymorphic forms calcite and aragonite was possible with the Renishaw RA100 and BWTEK BWS415 i‐Raman instruments, the ones provided with higher spectral resolutions. Concerning the degradation products, gypsum (CaSO4· 2H2O) and amorphous carbon (soot) were detected in samples from three locations, but the most damaged stones are those of Aixerrota, which show higher amounts of both decay products, identified by the three Raman instruments, as the main agent responsible for stone decay. Some nitrate compounds were determined in a mortar sample from the location of the highest impacted environment (Aixerrota), and whewellite (CaC2O4· H2O) and weddellite (CaC2O4· 2H2O) appeared in some sandstones from Arriluze and joint mortars from Aixerrota derived from micro‐organism activity. However, the ultramobile equipments were not capable of detecting the presence of nitrates and oxalates, due to high fluorescence (DeltaNu) and thermo‐decomposition (BWTEK) problems. Copyright © 2008 John Wiley & Sons, Ltd.
Thiol‐immobilized silver nanoparticle aggregate films for surface enhanced Raman scattering
Authors: Caro Carlos , López‐Cartes Carlos , Zaderenko Paula , Mejías José A.
Published: March 2008

We report a novel method for the fabrication of films of silver nanoparticle aggregates that are strongly attached to Si substrates (Thiol‐immobilized silver nanoparticle aggregates or TISNA). The attachment is achieved by chemically modifying the surface of a Si(100) surface in order to provide SH groups covalently linked to the substrate and then aggregating silver nanoparticles on these thiol covered surfaces. The transmission electron microscopy (TEM), scanning electron microscopy (SEM) and atomic force microscopy (AFM) characterization show a high coverage with single nanoparticles or small clusters and a partial coverage with fractal aggregates that provide potential hot spots for surface enhanced Raman scattering (SERS). We have confirmed the SERS activity of these films by adsorbing rhodamine 6G and recording the Raman spectra at several concentrations. By using the silver‐chloride stretching band as an internal standard, the adsorbate bands can be normalized in order to correct for the effects of focusing and aggregate size, which determine the number of SERS active sites in the focal area. This allows a quantitative use of SERS to be done. The adsorption–desorption of rhodamine 6G on TISNA films is reversible. These features make our TISNA films potential candidates for their use in chemical sensors based on the SERS effect. Copyright © 2008 John Wiley & Sons, Ltd.
Vibrational and surface‐enhanced Raman spectra of vanillic acid
Authors: Clavijo E. , Menéndez J. R. , Aroca R.
Published: March 2008

The 3‐methoxy‐4‐hydroxybenzoic acid or vanillic acid (VA) is a naturally occurring molecule important in winemaking. The spectral fingerprints of VA observed in the infrared and Raman spectra are assigned to fundamental vibrational wavenumbers supported by quantum chemical computations. The surface‐enhanced Raman scattering (SERS) of the VA has been obtained in silver colloidal solutions making possible analytical applications for detection of VA at picomole concentrations. Copyright © 2008 John Wiley & Sons, Ltd.
Genetic variants in germline TP53 and MDM2 SNP309 are not associated with early onset colorectal cancer
Authors: Khan Sajid A. , Idrees Kamran , Forslund Ann , Zeng Zhaoshi , Rosenberg Shoshana , Pincas Hanna , Barany Francis , Offit Kenneth , LaQuaglia Michael P. , Paty Philip B.
Published: March 2008

Background and Objectives

Colorectal cancer (CRC) arising in patients under age 30 is a rare disease, and few cases have been reported within Li‐Fraumeni kindreds. To determine how often alterations in the p53 pathway genes contribute to disease susceptibility, we have evaluated patients with early onset CRC for the presence of germline variants in the p53 gene and MDM2 SNP309.

Methods

Thirty‐five patients with CRC diagnosed before age 30 were included in this study‐based on tissue availability. DNA samples from peripheral blood leukocytes were analyzed for constitutional mutations and polymorphisms in p53 as well as polymorphisms in MDM2 SNP309.

Results

No mutations were found in exons 4–10 of the p53 gene. The frequencies of polymorphisms in p53 and in MDM2 SNP309 did not differ from rates previously reported for normal control populations, and no polymorphism in either gene could be associated with early onset CRC.

Conclusions

Neither germline variants in p53 nor MDM2 SNP309 play an underlying role in the development of very early onset CRC. For the large majority of cases, the genetic basis of this disease remains unknown. J. Surg. Oncol. 2008;97:621–625. © 2008 Wiley‐Liss, Inc.
Self‐Assembly of Arborescent Polystyrene‐graft‐Poly(ethylene oxide) Copolymers at the Air/Water Interface
Authors: Njikang Gabriel N. , Cao Lan , Gauthier Mario
Published: March 2008

AFM imaging was used to investigate the influence of molecular structure and composition on the formation of Langmuir monolayers by arborescent PS‐graft‐PEO copolymers at the air/water interface. Even without compression, these molecules associate spontaneously at the air/water interface and form stable monolayers that are easily transferred onto solid substrates as Langmuir/Blodgett films. The copolymers either form aggregates with a low association level, large island‐like clusters, or ribbon‐like superstructures. The different behaviors of the copolymers are rationalized in terms of the influence of their composition and of the structure of the arborescent PS cores on the assembly process.

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The Effect of Activation/Deactivation Processes on the Microcomposition and Microsequence Structure of Controlled/Living Copolymers
Authors: Shi Ying , Qin Xuelian , Guo Yumei , Xie Meiran , Zhang Yiqun
Published: March 2008

A new method is proposed to study the process of controlled/living radical copolymerization as well as the structures of the products. Computer simulation has been carried out to produce this LRP or CRP propagation including the activation/deactivation process. The information about segment distribution was obtained for the first time. The results show that under a stationary condition, controlled/living copolymer's composition and sequence distribution are totally identical to those prepared from the conventional free radical copolymerization (FRcP). In other words, the activation/deactivation process of controlled/living radical copolymerization has no effect on copolymer's microcomposition and microsequence structure.

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p16INK4adownregulation is involved in immortalization of primary human prostate epithelial cells induced by telomerase
Authors: Shao Genze , Balajee Adayabalam S. , Hei Tom K. , Zhao Yongliang
Published: March 2008

Prostate cancer is a major cause of cancer death among male population. Therefore, development of appropriate model systems is critical for understanding the molecular basis of prostate cancer progression. In this study, introduction of human telomerase (hTERT) into normal human prostate epithelial cells (PrECs) renders them higher telomerase activity, elongated telomere length and an extended proliferative lifespan. The immortal mass culture of PrEC–hTERT cell line with stabilized telomere length has been established using hTERT transfection. However, activation of hTERT alone appears to be insufficient for immortalization of PrEC cells because methylation ofp16INK4apromoter has been found to be involved in the immortalization process. p53 was functionally intact and no mutations ofp53gene were identified in the immortalized PrECs. In addition, the immortal PrECs show a near diploid complement of chromosomes albeit a few reciprocal and non‐reciprocal translocations are identified. They are anchorage dependent and do not form tumors in immunosuppressed host animals. Therefore, premalignantly transformed human PrECs provide a valuable model for prostate cancer research. © 2008 Wiley‐Liss, Inc.
Pleiotrophin inhibits transforming growth factor β1‐induced apoptosis in hepatoma cell lines
Authors: Park Tae Jun , Jeong Bo Ra , Tateno Chise , Kim Hong Seok , Ogawa Tomohiro , Lim In Kyoung , Yoshizato Katsutoshi
Published: March 2008

Pleiotrophin (PTN) is a hepatocyte growth factor and considered to play roles in liver fibrogenesis and hepatocarcinogenesis. In this study we examined the mechanism of the action of PTN in these pathological processes. First, we confirmed that hepatic stellate cells (HSCs) and Kupffer cells, and also later hepatocytes in hyperplastic nodules increased PTN mRNA expressions during carbon tetrachloride‐induced liver fibrosis. Then, the relationship between PTN and transforming growth factor β1 (TGFβ1), a known potent pro‐fibrogenetic cytokine, in carcinogenesis was investigated using hepatoma cell lines. Huh‐7 human hepatoma cells weakly expressed PTN, but HepG2 human hepatoma cells and FaO rat hepatoma cells did not. Recombinant (r) TGFβ1 induced the cultured Huh‐7 cells to undergo apoptosis, which was inhibited by rPTN. Huh‐7 cells became resistant to TGFβ1‐, but not mitomycin C‐induced apoptosis when transfected with PTN gene, indicating the specificity of the PTN anti‐apoptotic activity. Poly ADP ribose polymerase, procaspase‐8 and procaspase‐3 were not cleaved in the TGFβ1‐reluctant cells. The TGFβ1‐induced caspase‐3 activation was also suppressed in Huh‐7 and FaO cells both transduced with PTN gene‐bearing adenoviruses. In summary, PTN was expressed in HSCs, Kupffer cells, and hepatocytes in fibrotic liver. We propose that PTN specifically antagonizes the TGFβ1 activity during liver fibrosis. © 2008 Wiley‐Liss, Inc.
Task‐specific craniocervical dystonia
Authors: Schramm Axel , Naumann Markus , Reiners Karlheinz , Classen Joseph
Published: March 2008

The pathophysiology of dystonia is incompletely understood. Unlike many other focal dystonias, cervical dystonia, a frequent dystonia leading to twisting of the head, does not appear to be related to overuse or acquisition of a demanding motor skill. Here, we report development of task‐specific dystonia of the neck muscles in a 67‐year‐old patient following bilateral traumatic arm amputation at the age of 15. To compensate for the amputation, the patient learned to write with a pen held in his mouth. After several years of practicing this unusual and demanding skill, symptoms of task‐specific cervical dystonia (CD) developed. This dystonia later became permanent, and independent of the motor activity that initially triggered the dystonic muscular contractions. This singular case raises the possibility that the pathophysiology of CD may share common elements with that of focal dystonias in different body regions. © 2008 Movement Disorder Society
Conservation properties of the bridging domain method for coupled molecular/continuum dynamics
Authors: Xu Mei , Belytschko Ted
Published: March 2008

An overlaid domain decomposition method, called the bridging domain method, for the coupled simulation of molecular/continuum systems is analyzed. In this method, compatibility between the atomistic and the continuum subdomains is enforced by Lagrange multipliers. Two forms are considered: (1) a consistent constraint form, which employs the exact non‐diagonal Lagrange multiplier equations and thus enforces compatibility exactly, but is computationally demanding and (2) a diagonalized constraint form, which is computationally more efficient. It is shown that the consistent constraint form conserves linear momentum, angular momentum and energy. The diagonalized constraint form dissipates energy. The diagonalized form is shown to be more effective in suppressing spurious reflections at the interface. Copyright © 2008 John Wiley & Sons, Ltd.
Representation of elastomers in industrial applications
Authors: Baaser H.
Published: March 2008

A material model is presented to describe inelastic effects in elastomeric components. In static cases, stress softening and permanent deformations are identified as cause of inelasticity. Both effects are covered separately in the constitutive law. This permits the largely modular design of a material description on the basis of user interfaces in commercial FE programs and allows for easier parameter adjustment as the effects can be clearly allocated and identified. The hyperelastic part of the material answer is defined by any freely chosen function of the strain energy, while the inelastic part is of a non‐linear, isotropic hardening type. The presented model is realized in the ABAQUS Finite Element system. The efficiency of the implementation is shown on an example from the hydraulic sealing technology. Further on, we discuss a modification applied to finite viscoelasticity to represent amplitude dependence as observed our in experiments. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Newton methods for nonlinear inverse problems with random noise
Authors: Bauer Frank , Hohage Thorsten , Munk Axel
Published: March 2008

We study the convergence of regularized Newton methods applied to nonlinear operator equations in Hilbert spaces if the data are perturbed by random noise. We show that under certain conditions it is possible to achieve the minimax rates of the corresponding linearized problem if the smoothness of the solution is known. If the smoothness is unknown and the stopping index is determined by Lepskij's balancing principle, we show that the rates remain the same up to a logarithmic factor due to adaptation. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A two immiscible liquids penetration model for surface‐driven capillary flows
Authors: Fazio Riccardo , Iacono Salvatore , Jannelli Alessandra , Cavaccini Giovanni , Pianese Vittoria
Published: March 2008

This is a mathematical and numerical study of liquid dynamics in a horizontal capillary. We present a two‐liquids model which takes into account the effects of real phenomena like the outside flow dynamics. Moreover, we report on results obtained by an adaptive numerical method. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Linear interpolation for image conversion between square structure and hexagonal structure
Authors: He Xiangjian , Li Jianmin
Published: March 2008

Spiral Architecture (SA) is a relatively new and powerful image structure consisting of hexagonal pixels arranged in a onedimensional coordinate system. However, all the existing hardware for capturing image and for displaying image are produced based on traditional square image structure. In this paper, we present a software approach to represent an image on SA based on linear interpolation method. We perform edge detection on SA to demonstrate the advantages of image processing on SA. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The influence of semi‐rigid connections on the shakedown of elasto‐plastic frames
Authors: Kaliszky Sándor , Lógó János
Published: March 2008

The main structural elements of steel framed multi‐storey structures are the columns, the beams and their connections. The assumption has been widely applied in the past that the connections are either rigid or pinned. The actual behaviour of the connections is however somewhere between these limits, they are semi‐rigid. The aim of this paper is to analyze the effect of the semi‐rigid connections on the shakedown of steel structures under multi‐parameter static loading. In the analysis, to control the plastic behavior of the structure, bound on the complementary strain energy of the residual forces is applied. The formulation of the problem yields to nonlinear mathematical programming. The results of the numerical calculation show that the semi‐rigid connections can influence significantly the magnitude of the shakedown parameter. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Elliptic grid generation methods for scattering from multiple obstacles
Authors: Villamizar Vianey , Acosta Sebastian
Published: March 2008

A novel finite difference time domain method for acoustic scattering on generalized curvilinear coordinates is briefly described. Scattering over two‐dimensional complex regions consisting of multiple scatterers are analyzed. The grid generation algorithm decomposes regions with finite number of holes to contiguous single‐hole subregions. Individual grids are obtained for each subregions and they are matched with smoothness across interfaces. The new algorithm is an extension to multiple obstacles of the technique introduced in [V. Villamizar, M. Weber, Boundary‐Conforming Cordinates with Grid Line Control for Acoustic Scattering from Complexly Shaped Obstacles, Numer. Meth. Part Differ. Equ. 23 (2007) 1445–1467]. The method is successfully applied to approximate the pressure field resulting from the acoustic scattering of a plane wave from two complexly‐shaped obstacles. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Configurational‐force‐based structural updates and adaptive remeshing strategies
Authors: Zimmermann Dominik , Miehe Christian
Published: March 2008

The application of configurational forces in h ‐adaptive strategies for fracture mechanics and inelasticity is investigated. Starting from a global Clausius‐Planck inequality, dual equilibrium conditions are derived by means of a Coleman‐type exploitation method. The remaining reduced dissipation inequality is used for the derivation of evolution equations for the internal variables. In fracture mechanics, crack loading conditions as well as a normality rule for the crack propagation are obtained. In the discrete setting, the crack propagation is governed by a configurational‐force‐driven update of the geometry model. The material balance equation is used to set up a h ‐adaptive refinement indicator. A relative global criterion is defined used for the decision on mesh refinement. In addition, a criterion on the element level is evaluated controlling the local refinement procedure. The capability of the proposed procedures is demonstrated by means of numerical examples. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
For the majority of patients with diabetes blood pressure and lipid management is not in line with recommendations. Results from a large population‐based cohort in Germany
Authors: Raum Elke , Lietzau Susanne , Stegmaier Christa , Brenner H. , Rothenbacher Dietrich
Published: March 2008

Objective

To evaluate the management of cardiovascular risk factors in a population‐based cohort of adults with diabetes mellitus in Germany.

Design and Measurements

For the 9953 participants (50–74 years of age) of the ESTHER study, diabetes mellitus, hypertension, dyslipidemia and the respective medication were documented at baseline by their primary care physician. Blood pressure was taken and lipid levels were determined from a blood sample drawn at recruitment. Lifestyle factors (smoking, BMI, physical activity) were documented by the participants. Prevalence of pharmacotherapy for and control of hypertension and dyslipidemia among diabetic patients with these diagnoses were assessed and determinants were evaluated by multiple logistic regression.

Results

Diabetes mellitus was present in 1375 participants (14.2%). Almost 78% of diabetic participants had physician diagnosed hypertension, 86.0% received pharmacotherapy, but only 12.8% of those with anti‐hypertensive medication achieved blood pressure levels below 130/85 mmHg. Obese participants were more likely to receive anti‐hypertensive pharmacotherapy than non‐obese ones: adjusted odds ratio (OR, 95% confidence interval (CI)): 3.58 (1.86–6.87). Gender had no influence on anti‐hypertensive pharmacotherapy. Older diabetic patients with hypertension were less likely to have sufficient blood pressure control than younger ones. Dyslipidemia was documented in 50% of diabetic patients. Diabetic participants with coronary heart disease or hypertension were more likely to receive lipid‐lowering pharmacotherapy than those without these conditions (adjusted OR 1.85 (95%CI 1.19–2.89) and 2.59 (95%CI 1.41–4.74), respectively).

Conclusions

For most elderly with diabetes cardiovascular risk factor management continues to be not in line with recommendations. Copyright © 2008 John Wiley & Sons, Ltd.
Missing item imputation for quality‐of‐life instruments with application to asthma quality‐of‐life questionnaires
Authors: Wang Jixian , Rapatz Guenter , Lowy Adam , Olson Sabine , Kuebler Juergen
Published: March 2008

There has been increasing use of quality‐of‐life (QoL) instruments in drug development. Missing item values often occur in QoL data. A common approach to solve this problem is to impute the missing values before scoring. Several imputation procedures, such as imputing with the most correlated item and imputing with a row/column model or an item response model, have been proposed. We examine these procedures using data from two clinical trials, in which the original asthma quality‐of‐life questionnaire (AQLQ) and the miniAQLQ were used. We propose two modifications to existing procedures: truncating the imputed values to eliminate outliers and using the proportional odds model as the item response model for imputation. We also propose a novel imputation method based on a semi‐parametric beta regression so that the imputed value is always in the correct range and illustrate how this approach can easily be implemented in commonly used statistical software. To compare these approaches, we deleted 5% of item values in the data according to three different missingness mechanisms, imputed them using these approaches and compared the imputed values with the true values. Our comparison showed that the row/column‐model‐based imputation with truncation generally performed better, whereas our new approach had better performance under a number scenarios. Copyright © 2008 John Wiley & Sons, Ltd.
Retracted and replaced:Impact of observational error on the validation of ensemble prediction systems
Authors: Candille G. , Talagrand O.
Published: March 2008

This article has been retracted and replaced.Please see retraction notice DOI:10.1002/qj.273.

Replacement article DOI:10.1002/qj.268 published in QJ 134:633 Part B.
Novel possibilities in the study of isolated carbon nanotubes
Authors: Avdoshenko Stanislav M. , Ioffe Il'ya N. , Kozlov Andrey A. , Markov Vitaliy Yu. , Nikolaev Evgeniy N. , Sidorov Lev N.
Published: March 2008

We report the first detection of carbon nanotubes in the gas phase in a matrix‐assisted laser desorption/ionization (MALDI) mass spectrometric experiment. These observations open the possibility of studying isolated nanotubes in the gas phase by means of various spectroscopic methods and a possible way to separate them. Copyright © 2008 John Wiley & Sons, Ltd.
Determination of selected non‐authorized insecticides in peppers by liquid chromatography time‐of‐flight mass spectrometry and tandem mass spectrometry
Authors: Mezcua Milagros , Ferrer Carmen , García‐Reyes Juan F. , Martínez‐Bueno María Jesús , Albarracín Micaela , Claret María , Fernández‐Alba Amadeo R.
Published: March 2008

In this work, two analytical methods based on liquid chromatography coupled to electrospray time‐of‐flight mass spectrometry (LC/ESI‐TOFMS) and tandem mass spectrometry (LC/ESI‐MS/MS) are described for the identification, confirmation and quantitation of three insecticides non‐authorized in the European Union (nitenpyram, isocarbophos and isofenphos‐methyl) but detected in recent monitoring programmes in pepper samples. The proposed methodologies involved a sample extraction procedure using liquid‐liquid partition with acetonitrile followed by a cleanup step based on dispersive solid‐phase extraction. Recovery studies performed on peppers spiked at different fortification levels (10 and 50 µg kg−1) yielded average recoveries in the range 76–100% with relative standard deviation (RSD) (%) values below 10%. Identification, confirmation and quantitation were carried out by LC/TOFMS and LC/MS/MS using a hybrid triple quadrupole linear ion trap (QqLIT) instrument in multiple‐reaction monitoring (MRM) mode. The obtained limits of quantitation (LOQs) were in the range 0.1–5 µg kg−1, depending on each individual technique. Finally, the proposed methods were successfully applied to the analysis of suspected pepper samples. Copyright © 2008 John Wiley & Sons, Ltd.
Computer‐aided diagnosis using morphological features for classifying breast lesions on ultrasound
Authors: Huang Y.‐L. , Chen D.‐R. , Jiang Y.‐R. , Kuo S.‐J. , Wu H.‐K. , Moon W. K.
Published: March 2008

Objectives

To develop and evaluate a computer‐aided diagnosis (CAD) system with automatic contouring and morphological analysis to aid in the classification of breast tumors using ultrasound.

Methods

We evaluated 118 breast lesions (34 malignant and 84 benign tumors). Each tumor contour was automatically extracted from the digitized ultrasound image. Nineteen practical morphological features from the extracted contour were calculated and principal component analysis (PCA) was applied to find independent features. A support vector machine (SVM) classifier utilized the selected principal vectors to identify the breast tumor as benign or malignant. In this study, all the cases were sampled with k‐fold cross‐validation (k = 10) to evaluate the performance by receiver–operating characteristics (ROC) curve analysis.

Results

The areas under the ROC curves for the proposed CAD systems using all morphological features and the lower‐dimensional principal vector were 0.91 and 0.90, respectively. The classification ability for breast tumors using morphological information was good.

Conclusions

This system differentiates benign from malignant breast tumors well and therefore provides a clinically useful second opinion. Moreover, the morphological features are nearly setting‐independent and thus available to various ultrasound machines. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Cost-effectiveness of cemented versus cementless total hip arthroplasty. A Markov decision analysis based on implant cost
Authors: Marinelli M. , Soccetti A. , Panfoli N. , de Palma L.
Published: March 2008

Background

Probabilistic decision analysis is a means of reflecting the uncertainty parameter in models and of presenting it in a comprehensible manner to decision-makers.

Materials and methods

A cost-effectiveness model was constructed to compare the cementless and cemented total hip prostheses implanted at our department in terms of lifetime costs and quality-adjusted life-years (QALY). Revision rates were obtained from the Orthopaedic Prosthesis Register of the Laboratory of Medical Technology, Istituti Ortopedici Rizzoli, Bologna, Italy.

Results

The risk of early revision (at 5 years of follow-up) for cementless and cemented prostheses was 1.6% and 1.4%, respectively, resulting in equal QALY for the two implant types. Analysis of mean cost and QALY indicated that use of either implant is not associated with cost savings.

Discussion

Management with cementless or cemented total hip prostheses in a theoretical cohort of 70-year-old patients with fracture of the femoral neck or arthritis involving the hip is not significantly different according to the probabilistic results from the model.
Effects of growth factors and kinase inhibitors on the properties of human adipose‐stromal cells in different culture conditions
Authors: Cheon Sang Jin , Kim Jeung Il , Lee Jung Sub
Published: March 2008

The best‐fit environments for the proliferation and differentiation of human adipose tissue‐derived stromal cells (hADSCs) may require specific media and stimuli. The characteristics of hADSCs cultured in different media might be different. We evaluated the effects of growth factors on the proliferation and differentiation of hADSCs and compared the effects of these growth factors on hADSCs cultured in different serum‐contained media. The effects of kinase inhibitors on the proliferation of hADSCs were also examined.

The combination of insulin—transferrin—selenium (ITS) and fibroblast growth factor (FGF) induced the greatest increase in proliferation, while the combination of ITS and epidermal growth factor (EGF) showed the second‐greatest effect in the human serum (HS)‐contained media. By contrast, in the fetal bovine serum (FBS)‐contained media, ITS had little effect while FGF had better results than the combination of ITS and EGF. The inhibitory potency of the kinase inhibitors was different in the two different media. These results suggest that hADSCs may have different characteristics according to the culture conditions, and that extrapolations of results from animal studies, using FBS media, may not correlate to findings in human studies using HS.
Calcium‐sensing receptors induce apoptosis in cultured neonatal rat ventricular cardiomyocytes during simulated ischemia/reperfusion
Authors: Jiang Chun‐ming , Han Li‐Ping , Li Hong‐Zhu , Qu Ying‐Bo , Zhang Zhuo‐Ran , Wang Rui , Xu Chang‐qing , Li Wei‐ming
Published: March 2008

Calcium‐sensing receptors (CaSRs) are G‐protein coupled receptors which regulate systemic calcium homeostasis and also participate in cell proliferation, differentiation and apoptosis. We have previously shown that CaSR can induce apoptosis in isolated rat adult hearts and in normal rat neonatal cardiomyocytes. However, no knowledge exists concerning the role of CaSR in apoptosis induced by ischemia and reperfusion in neonatal cardiac myocytes. Therefore, in the present study, we incubated primary neonatal rat ventricular cardiomyocytes in ischemia‐mimetic solution for 2 h, then re‐incubated them in a normal culture medium for 24 h to establish a model of simulated ischemia/reperfusion (I/R). We assayed the apoptotic ratio of the cardiomyocytes by flow cytometry; observed morphological alterations by transmission electron microscope; analyzed the expression of caspase‐3, Bcl‐2, CaSR, extracellular signal‐regulated protein kinase (ERK), and Fas/Fas ligand (FasL) by Western blotting; and measured the concentration of intracellular calcium by Laser Confocal Scanning Microscopy. The results showed that simulated I/R increased the expression of CaSR and cardiomyocyte apoptosis. GdCl3, a specific activator of CaSR, further enhanced CaSR expression, along with increases in intracellular calcium and apoptosis in cardiomyocytes during I/R. Activation of CaSR down‐regulated Bcl‐2 expression, up‐regulated caspase‐3 and Fas/FasL expression and stimulated ERK1/2 phosphorylation. In summary, CaSR is involved in I/R injury and apoptosis of neonatal rat ventricular cardiomyocytes by inhibiting Bcl‐2, inducing calcium overload and activating the Fas/FasL death receptor pathway.
Management of cancer pain in Korea
Authors: Lee Sang Chul
Published: March 2008

Pain occurs in up to 70% of patients with advanced cancer and in about 65% of patients dying from non‐malignant disease. Pain can be controlled in most cases (about 80%) using a simple, stepwise approach and a limited number of analgesics as set out in the World Health Organization (WHO) analgesic ladder. About 10% of patients will require more complex, sometimes invasive, management to control their pain, leaving the remaining 10% with cancer pain that is difficult to control. A high prevalence of undertreated cancer pain has indeed been reported in several clinical settings.

In Korea, approximately 100,000 new cases of cancer are diagnosed each year, and incidence has increased in the past 15 years. Recently, the management of cancer pain has received increased attention from healthcare professionals such as pain physicians, oncologists, and palliative care providers. In 2001, the guidelines on cancer pain management were distributed to Korean physicians by the Korean Society of Hospice and Palliative Care. However, little data are available concerning the management of cancer pain in Korea.

There are many measures available to manage cancer pain in Korea. Examples are medication (NSAIDs, opioids etc.), nerve block and neurolysis, ketamine infusion therapy, radiofrequecy, vertebroplasty and so on.

The management of pain is an essential component of a comprehensive approach to patients with cancer for the entire course of the disease, and there is no reason for these patients to have ongoing pain with the full range of drugs and strategies currently available.
Predicting pain and pain responses to opioids
Authors: Wilder‐Smith Clive H.
Published: March 2008

The mechanisms behind the wide individual variability in pain experience and relief are an area of intense research activity. Predicting individual clinical pain and the responsiveness to analgesics should increase the efficacy and tolerability of analgesic treatments, and improve the overall treatment outcome. Several factors have shown validity in the prediction of pain, with most studies having been performed in postoperative pain. These factors include younger age, female gender, multiple psychosocial contributors (e.g. negative affect, somatisation, depressive mood, expectations, anxiety), pre‐existing physical comorbidities and pain, information provided by carers, and the nature of the pain insult. Recent studies have shown quantitiative sensory testing at high stimulus intensity (e.g. pain thresholds), as well as specific genetic factors and the functional testing of the endogenous pain modulatory pathways as emerging useful tools in the study of individual pain variability.

Many of the above factors are also relevant in the prediction of analgesic responsiveness. The predominant pain characteristics, pain chronicity and neuroplastic changes, opioid‐related genetic factors and psychological factors (including placebo response components) are major determinants of analgesic efficacy. Prediction of analgesia using quantitative sensory tests has been studied with some success.

Better prediction of individual pain and analgesic responsiveness promises to improve pain control and general treatment outcome, and reduce adverse events as well as costs. Further prospective studies with interdisciplinary input validating the usefulness of predictive variables within algorithms are encouraged in large patient cohorts.