bluuebunny/crossref_metadata_2025_split huggingface dataset:
Compatibilization and development of layered silicate nanocomposites based of unsatured polyester resin and customized intercalation agent
Authors: Torre Luigi , Chieruzzi Manuela , Kenny Josè M. 
Published: November 2009

AbstractIn this study a procedure for the preparation of compatibilized nanoclays was used to produce effective nanocomposites based on unsatured polyester (UP) resin. A compatibilization procedure of the filler with a selected surfactant has been developed and optimized, the effect of organic modifiers on the synthesized nanocomposites properties was studied. Moreover, polyester/clay nanocomposites were prepared. In particular, samples were prepared using two different mixing methods. The properties and formation processes of the nanocomposites obtained using the two methods were compared. X‐ray diffraction studies revealed the formation of intercalated/exfoliated nanocomposites structures. The effect of processing parameters, used for both the compatibilization procedure and the preparation of nanocomposites, was studied. Dynamic mechanical, thermal analysis, and rheological tests were performed to investigate the formation mechanism of UP/montmorillonite nanocomposite. In particular, mechanical properties of nanocomposites were studied using dynamic mechanical analysis and tensile tests. Mechanical, rheological, and thermal characterization have confirmed the validity of the used approach to compatibilize the nanoclay and to produce nanocomposites. Tensile strength and Young's modulus were modified by the loading of the organoclays. Furthermore, the rheology of the nanocomposite formulation provided processing information, while mechanical and dynamic mechanical characterization was performed on the nanocomposites produced with the newly compatibilized formulation. The results have shown that nanocomposites with better mechanical properties can be obtained through the selection of an appropriate compatibilization process. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Preparation and characterization of novel hybrid of bio‐assisted mineralized Zn‐Al layered double hydroxides using chitosan as a template
Authors: Depan Dilip , Singh Raj Pal 
Published: November 2009

AbstractThe purpose of this study was to prepare and characterize a novel nanohybrid prepared from the template‐assisted mineralization of Zn‐Al Layered Double Hydroxide (LDH) onto the surface of Chitosan (CSI), with an emphasis on morphology, biocompatibility, and its use as an efficient drug carrier agent. The as prepared LDH is highly crystalline, with platelet‐like morphology and curved tactoids when nucleated onto the surface of CSI. Our results indicate that the OH and NH functional moieties on CSI can direct an ordered structure of LDH, due to the electrostatic interaction between biopolymer and inorganic lamellae. We have been successful to intercalate an anti‐inflammatory drug, Sodium Ibuprofen (Ibu), into LDH, through conventional coprecipitation method. LDHs are endowed with great potential for delivery vector because their stacked layers lead to safe reservation of biofunctional molecules or genes, and their ion exchangeability and solubility in acidic media (pH < 4) give rise to the controlled release of drug molecules. According to the cell‐growth studies, LDHs are found as cell viable up to the concentration of 500 μg/mL. This study reveals that LDH not only plays a role of a biocompatible‐delivery matrix but also facilitates a significant increase in the delivery efficiency. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
The effect of ram‐pressure stripping and starvation on the star formation properties of cluster galaxies
Authors: Boselli A. , Boissier S. , Cortese L. , Gavazzi G. 
Published: November 2009

AbstractWe have combined UV to radio centimetric observations of resolved galaxies in the Virgo cluster with multizone, chemospectrophotometric models of galaxy evolution especially tailored to take into account the effects of the cluster environment (ram pressure stripping and starvation). This exercise has shown that anemic spirals with truncated radial profiles of the gas component and of the young stellar populations, typical in rich clusters of galaxies, have been perturbed by a recent (∼100 Myr) ram pressure stripping event induced by their interaction with the cluster intergalactic medium. Starvation is not able to reproduce the observed truncated radial profiles. Both ram pressure and starvation induce a decrease of the stellar surface brightness of the perturbed disc, and thus can hardly be invoked to explain the formation of lenticular galaxies inhabiting rich clusters, which are characterised by higher surface brightnesses than early type spirals of similar luminosity. In dwarfs the ram pressure stripping event is so efficient to totally remove their gas thus stopping on short time scales (<2 Gyr) their star formation activity. Low luminosity star forming discs can be transformed in dE galaxies (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cool gas accretion, thermal evaporation, and quenching of star formation in elliptical galaxies
Authors: Nipoti C. 
Published: November 2009

AbstractThe most evident features of colour‐magnitude diagrams of galaxies are the red sequence of quiescent galaxies, extending up to the brightest elliptical galaxies, and the blue cloud of star‐forming galaxies, which is truncated at a luminosity L ∼ L*. The truncation of the blue cloud indicates that in the most massive systems star formation must be quenched. For this to happen the virial‐temperature galactic gas must be kept hot and any accreted cold gas must be heated. The elimination of accreted cold gas can be due to thermal evaporation by the hot interstellar medium, which in turn is prevented from cooling by feedback from active galactic nuclei (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The effect of clouds on the dynamical and chemical evolution of gas‐rich dwarf galaxies
Authors: Recchi S. , Hensler G. 
Published: November 2009

AbstractWe study the effects of clouds on the dynamical and chemical evolution of gas‐rich dwarf galaxies, in particular focusing on two model galaxies similar to IZw18 and NGC 1569. We consider both scenarios, clouds put at the beginning of the simulation and continuously created infalling ones. Due to dynamical processes and thermal evaporation, the clouds survive only a few tens of Myr, but during this time they act as an additional cooling agent and the internal energy ofcloudy models is typically reduced by 20–40% in comparison with models without clouds. The clouds delay the development of large‐scale outflows, therefore helping to retain a larger amount of gas inside the galaxy. However, especially in models with continuous creation of infalling clouds, their bullet effect can pierce the expanding supershell and create holes through which the superbubble can vent freshly produced metals. Moreover, assuming a pristine chemical composition for the clouds, their interaction with the superbubble dilutes the gas, reducing the metallicity (by up to ∼0.4 dex) with respect to the one attained by diffuse models (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Probing evolutionary mechanisms in galaxy clusters: H I in Abell 1367
Authors: Scott T.C. , Bravo‐Alfaro H. , Brinks E. , Cortese L. , Boselli A. 
Published: November 2009

AbstractWe are carrying out a programme of CO and interferometric H I observations in the nearby galaxy cluster Abell 1367. The aim is to better understand the processes driving the evolution of the ISM in late‐type galaxies in the cluster environment. Abell 1367 is a dynamically young cluster. We have determined the H I content and g – i colour from AGES (Cortese 2008) and SDSS, respectively, of its bright late‐type galaxies (spirals) in a volume centred on the NW subcluster. We use a combination of these characteristics, both of which are indicative of evolutionary history, to classify each spiral into one of four evolutionary states. This analysis revealed the cluster contains spirals in a wide range of evolutionary states. VLA D‐array imaging centred on the NW subcluster indicates most galaxies in that field have their H I intensity maximum offset relative to its optical counterpart, implying a recent and strong disturbance. The direction of this offset is not always consistent with a simple scenario of ram pressure stripping by the cluster's high density intra‐cluster medium (ICM) (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
SCG0018‐4854: A young and dynamic compact group
Authors: Presotto V. , Temporin S. , Pompei E. , Iovino A. 
Published: November 2009

AbstractIt is widely recognized in the literature that processes taking place within the group environment are among the main drivers of galaxy evolution. SCG0018‐4854 is a compact group of galaxies located at a distance of v ∼ 3200 km s–1. It is composed of four galaxy members, very close to each other on the sky: their median projected distance is only ∼20 Kpc (H = 70 km s–1Mpc–1). The remarkably high local galaxy density coupled with the low velocity dispersion (∼100 km s–1) characterizing this group, makes SCG001 8‐4854 a test case to study in detail the interplay between the environment and the galaxy properties. We present here some of the properties of the group members that are related to their mutual interaction, as derived from our kinematical and morphological analysis (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Smooth, undisturbed dwarf spheroidal galaxies in the Perseus cluster core: Implications for dark matter content
Authors: Penny Sj. , Conselice Cj. , De Rijcke S. , Held E.V. 
Published: November 2009

AbstractUsing deep HST/ACS observations of the core of the Perseus Cluster, we identify a large population of dwarf elliptical galaxies down to MV = –12. All these dwarfs are remarkably smooth in appearance, showing no evidence for internal features that could be the result of tidal processes or star formation induced by the cluster potential. Based on these observations and the relatively large sizes of these dwarfs, we argue that at least some must have a large dark matter component to prevent their disruption by the cluster potential. We further derive a new method to quantify the dark matter content of cluster dSphs without the use of kinematics, which are impossible to obtain at these distances. We find that mass‐to‐light ratios for dwarfs in the core of the Perseus Cluster are comparable to those found for Local Group dSphs, ranging between M⊙/L⊙ ≈ 1 and 120. This is evidence that dwarf spheroidals reside in dark matter subhalos that protect them from tidal processes in the cores of dense clusters (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transport of cosmic rays in the nearby starburst galaxy NGC 253
Authors: Heesen V. , Beck R. , Krause M. , Dettmar R.‐J. 
Published: November 2009

AbstractRadio halos require the coexistence of extra‐planar cosmic rays and magnetic fields. Because cosmic rays are injected and accelerated by processes related to star formation in the disk, they have to be transported from the disk into the halo. A vertical large‐scale magnetic field can significantly enhance this transport. We observed NGC 253 using radio continuum polarimetry with the Effelsberg and VLA telescopes. The radio halo of NGC 253 has a dumbbell shape with the smallest vertical extension near the center. With an estimate for the electron lifetime, we measured the cosmic‐ray bulk speed as 300 ± 30 km s–1 which is constant over the extent of the disk. This shows the presence of a “disk wind” in NGC 253. We propose that the large‐scale magnetic field is the superposition of a disk (r, ϕ) and halo (r, z) component. The disk field is an inward‐pointing spiral with even parity. The conical (even) halo field appears in projection as an X‐shaped structure, as observed in other edge‐on galaxies. Interaction by compression in the walls of the superbubbles may explain the observed alignment between the halo field and the lobes of hot Hα and soft X‐ray emitting gas. The disk wind is a good candidate for the transport of small‐scale helical fields, required for efficient dynamo action, and as a source for the neutral hydrogen observed in the halo (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Morphological properties of isolated galaxies vs. isolation criteria
Authors: Vavilova I.B. , Melnyk O.V. , Elyiv A.A. 
Published: November 2009

AbstractWe studied the morphological properties of isolated galaxies samples in dependence on the isolation parameter and properties of primary catalogs. With this aim we identified the samples of single and isolated galaxies from SDSS DR5 (Single and QIsol) with the 3D Voronoi tessellation method (Elyiv et al. 2009). We found that in comparison with other samples of isolated galaxies, the QIsol sample contains an excess of late‐type galaxies, especially with a low luminosity and BCG/Im/Irr morphology. We also showed that the fractions of early type galaxies in QIsol SDSS DR5 sample and samples 2MIG (Karachentseva et al. 2010) and CIG (Karachentseva et al. 1973; Hernandez‐Toledo et al. 2008) are in a good agreement (16–19 %), but Allam's (Allam et al. 2005) and Prada's (Prada et al. 2003) SDSS DR1 samples show a higher excess of the early type galaxies that can be explained by the selection criteria and morphology definition method. We found a weak relation between isolation parameter and color index for the Single sample that may indicate that even in the low dense environment the morphology density relation is observed. We conclude that morphological properties of the resulting sample of isolated galaxies are highly dependent on the primary catalogue from which the galaxies were selected. Moreover, the selection criterion is also important but plays a secondary role in the resulting morphological content, color indices distribution and other parameters of the isolated galaxy samples. Only four galaxies are common in the 2MIG, QIsol, and CIG samples, namely UGC5184, UGC6121, UGC8495, and UGC9598, that allows to consider them as really most isolated galaxies (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
NGC 1275: Baryonic cycing in the Perseus cluster of galaxies
Authors: Gallagher J.S. 
Published: November 2009

AbstractNGC 1275, the central galaxy of the Perseus cluster, contains a remarkable cool ISM. This gas is arrayed in a series of filaments extending over 30 kpc with an extension of 70 kpc to the north. These emit substantial cooling line radiation from HII, a hot H2 zone, and CO in a cool molecular region which contains most of the gas mass. This contribution briefly discusses some of the issues raised by the existence of this remarkable ISM system, including its connections to galactic feedback processes (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Early‐type dwarf galaxies in clusters: A mixed bag with various origins?
Authors: Lisker T. 
Published: November 2009

AbstractThe formation ofearly‐type dwarf(dE) galaxies, the most numerous objects in clusters, is believed tobe closely connected to the physical processes that drive galaxy cluster evolution, like galaxy harassment and ram‐pressure stripping. However, the actual significance ofeach mechanism for building the observed cluster dE population is yet unknown. Several distinct dE subclasses were identified, which show significant differences in their shape, stellar content, and distribution within the cluster. Does this diversity imply that dEs originate from various formation channels? Does “cosmological” formation play a role as well? I try to touch on these questions in this brief overview of dEs in galaxy clusters (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Disk galaxies and their environment
Authors: Kautsch S.J. , Gallagher J.S. , Grebel E.K. 
Published: November 2009

AbstractEnvironments of disk‐dominated galaxies and simple disk systems‐compared to systems with bulges‐provide a means to explore how environment relates to galaxy morphology. Our approach focuses on systems with edge‐on disks where disk‐to‐bulge ratios and disk flattening can be unambiguously determined and focuses on simple disks as evolutionary tracers. We study possible physical neighbors around the target disk galaxies and seek statistical relationships between local galaxy density and galaxy morphology. Galaxies consisting of simple stellar disks exist in environments ranging from the relatively the isolated field to moderate density galaxy groups. This distribution overlaps with that of systems with prominent bulges, although galaxies with large bulges are systematically rarer at low densities. The presence of simple disk galaxies in isolation and also in moderate density galaxy groups suggests that simple disks develop naturally in low density regions but have a limited ability to survive significant interactions with other galaxies. Simple disks thus are rare in denser galaxy systems where galaxy transformations are frequently driven by intense initial merging and later strong interactions (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Remote control laboratory via Internet using Matlab and Simulink
Authors: Puerto R. , Jiménez L.M. , Reinoso O. 
Published: November 2009

AbstractThis article describes the general architecture and application of a remote laboratory for teaching control theory based in Matlab/Simulink. The proposed system allows solving the time and spatial limitations of laboratories that rely on real physical systems used in control courses. In this way, control lab assignments with various physical processes present in the remote laboratories can be performed. Also, some examples that show the validity and applicability of the presented architecture are introduced. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 18: 694–702, 2010; View this article online at wileyonlinelibrary.com; DOI 10.1002/cae.20274
Synthesis of Optically Active Amines Employing Recombinant ω‐Transaminases in E. coli Cells
Authors: Koszelewski Dominik , Göritzer Madeleine , Clay Dorina , Seisser Birgit , Kroutil Wolfgang 
Published: November 2009

AbstractVarious recombinant ω‐transaminases, overexpressed in E. coli cells and employed as whole‐cell catalysts, are tested for the synthesis of enantiomerically pure amines from the corresponding prochiral ketones. Optically pure (S)‐amines are obtained by formal reductive amination, consuming just ammonia and a cheap reducing agent (formate) with up to 99 % ee and 97 % yield. The other enantiomer was accessible by employing the same ω‐transaminases in a kinetic resolution starting from racemic amines. A ω‐transaminase derived from an Arthrobacter species displayed the highest stereoselectivity for all substrates tested, both for the kinetic resolution of rac‐amines and for the amination of ketones.
Parallel vector analysis based soft resolution of spectral data from pH‐metric titration using symmetry constraint
Authors: Kompany‐Zareh Mohsen , Gholami Somayeh 
Published: November 2009

AbstractIn this study, a soft method is proposed to calculate concentration and spectral profiles for the two‐way spectral data from dissociation equilibria of polyprotic acids (HnA). This method has four main distinct steps: (i) a fixed size moving window evolving factor analysis (FSMWEFA) was used to identify the local rank map, (ii) WFA was applied to calculate the concentration profiles of HnA and An− (selection of the window for application of WFA was performed using EFA), (iii) PVA was used to calculate Hn − 1A to HA spectral profiles, and (iv) a symmetry constraint, in addition to the non‐negativity constraint, was utilized to obtain the unique concentration and spectral profiles from different acceptable sets of profiles. In the absence of any selective region in the spectral data, the proposed soft method resulted in unique solution without rotational ambiguity. This study is the first application of symmetry constraint on concentration profiles. The rotational ambiguity drastically decreased on considering the constraint of symmetry of the Hn − 1A and HA concentration profiles, in addition to non‐negativity of profiles. Simulated examples were used to confirm these approaches. Effect of closeness of dissociation constants on the estimated values of constants was investigated. The results showed that when the difference between pKa values is more than 1.2, the obtained errors in the estimation of pKa values are less than about 6.5%. The considered real data were from pH‐metric titration of fluorescein. The obtained spectral and concentration profiles and the estimated pKa values for fluorescein were in good agreement with the previously reported data. Copyright © 2009 John Wiley & Sons, Ltd.
Procalcitonin levels predict clinical course and progression‐free survival in patients with medullary thyroid cancer
Authors: Walter Martin A. , Meier Christian , Radimerski Tanja , Iten Fabienne , Kränzlin Marius , Müller‐Brand Jan , de Groot Jan Willem B. , Kema Ido P. , Links Thera P. , Müller Beat 
Published: November 2009

AbstractBACKGROUND:Procalcitonin has been well established as an important marker of sepsis and systemic infection. The authors evaluated the diagnostic and predictive value of calcitonin and its prohormone procalcitonin in medullary thyroid cancer.METHODS:The authors systematically explored the ability of calcitonin and procalcitonin to identify medullary thyroid cancer and predict the endpoints local recurrence and distant metastases, as well as the progression‐free survival. Patients with C‐cell hyperplasia; patients after thyroidectomy for differentiated thyroid cancer, goiter, or Graves disease; and healthy subjects served as controls. The study was performed in accordance with the Reporting Recommendations for Tumor Marker Prognostic Studies of the National Cancer Institute.RESULTS:Sixty‐nine medullary thyroid cancer patients and 96 controls were included (median observed interval: 10.9 years [range, 1.4‐47.5 years]; 981.8 patient‐years). The 1‐year, 5‐year, 10‐year, and 20‐year recurrence rates were 9%, 34%, 45%, and 56%, respectively. Calcitonin had a higher diagnostic accuracy for detecting medullary thyroid cancer than procalcitonin (area under the curve [AUC], 0.94; 95% confidence interval [95% CI], 0.90‐0.99 vs AUC, 0.89; 95% CI, 0.83‐0.95 [P = .038]). The procalcitonin:calcitonin ratio predicted disease progression (AUC, 0.63; 95% CI, 0.51‐0.75 [P = .036]) and progression‐free survival (hazards ratio, 1.49; 95% CI, 1.09‐2.04 [P = .013]).CONCLUSIONS:The results of the current study indicate a superior diagnostic accuracy of calcitonin and an independent predictive value of the procalcitonin:calcitonin ratio. These findings may lead to improved diagnostic and therapeutic strategies for medullary thyroid cancer patients. Cancer 2010. © 2010 American Cancer Society.
Global regularity and convergence of a Birkhoff‐Rott‐α approximation of the dynamics of vortex sheets of the two‐dimensional Euler equations
Authors: Bardos Claude , Titi Edriss S. , Linshiz Jasmine S. 
Published: November 2009

AbstractWe present an α‐regularization of the Birkhoff‐Rott equation (BR‐α equation), induced by the two‐dimensional Euler‐α equations, for the vortex sheet dynamics. We show the convergence of the solutions of Euler‐α equations to a weak solution of the Euler equations for initial vorticity being a finite Radon measure of fixed sign, which includes the vortex sheets case. We also show that, provided the initial density of vorticity is an integrable function over the curve with respect to the arc length measure, (i) an initially Lipschitz chord arc vortex sheet (curve), evolving under the BR‐α equation, remains Lipschitz for all times, (ii) an initially HölderC1, β, 0 ≤ β < 1, chord arc curve remains inC1, βfor all times, and finally, (iii) an initially HölderCn, β,n≥ 1, 0 < β < 1, closed chord arc curve remains so for all times. In all these cases the weak Euler‐α and the BR‐α descriptions of the vortex sheet motion are equivalent. © 2009 Wiley Periodicals, Inc.