bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stability of global and exponential attractors for a three‐dimensional conserved phase‐field system with memory
Authors: Mola Gianluca 
Published: May 2009

AbstractWe consider a conserved phase‐field system on a tri‐dimensional bounded domain. The heat conduction is characterized by memory effects depending on the past history of the (relative) temperature ϑ, which is represented through a convolution integral whose relaxation kernelkis a summable and decreasing function. Therefore, the system consists of a linear integrodifferential equation for ϑ, which is coupled with a viscous Cahn–Hilliard type equation governing the order parameter χ. The latter equation contains a nonmonotone nonlinearityϕand the viscosity effects are taken into account by a term −αΔ∂tχ, for some α⩾0. Rescaling the kernelkwith a relaxation time ε>0, we formulate a Cauchy–Neumann problem depending on ε and α. Assuming a suitable decay ofk, we prove the existence of a family of exponential attractors {ℰα,ε} for our problem, whose basin of attraction can be extended to the whole phase–space in the viscous case (i.e. when α>0). Moreover, we prove that the symmetric Hausdorff distance of ℰα,εfrom a proper lifting of ℰα,0tends to 0 in an explicitly controlled way, for any fixed α⩾0. In addition, the upper semicontinuity of the family of global attractors {𝒜α,ε} as ε→0 is achieved for any fixed α>0. Copyright © 2009 John Wiley & Sons, Ltd.
Characterization of response to radiation mediated gene therapy by means of multimodality imaging
Authors: Haney Chad R. , Parasca Adrian D. , Fan Xiaobing , Bell Rebecca M. , Zamora Marta A. , Karczmar Gregory S. , Mauceri Helena J. , Halpern Howard J. , Weichselbaum Ralph R. , Pelizzari Charles A. 
Published: May 2009

AbstractImaging techniques are under development to facilitate early analysis of spatial patterns of tumor response to combined radiation and antivascular gene therapy. A genetically modified, replication defective adenoviral vector (Ad.EGR‐TNFα), injected intratumorally, mediates infected cells to express tumor necrosis factor alpha (TNFα), which is increased after exposure to radiation. The goal of this study was to characterize an image based “signature” for response to this combined radiation and gene therapy in mice with human prostate xenografts. This study is part of an imaged guided therapy project where such a signature would be useful in guiding subsequent treatments. Changes in the tumor micro‐environment were assessed using MRI registered with electron paramagnetic resonance imaging which provides images of tissue oxygenation. Dynamic contrast‐enhanced MRI was used to assess tissue perfusion. When compared with null vector (control) treatment, the ratio of contrast agent (Gd‐DTPA‐BMA) washout rate to uptake rate was lower (P = 0.001) after treatment, suggesting a more balanced perfusion. Concomitantly, oxygenation significantly increased in the treated animals and decreased or did not change in the control animals (P < 0.025). This is the first report of minimally invasive, quantitative, absolute oxygen measurements correlated with tissue perfusion in vivo. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Motion artifact correction in free‐breathing abdominal MRI using overlapping partial samples to recover image deformations
Authors: White M. J. , Hawkes D. J. , Melbourne A. , Collins D. J. , Coolens C. , Hawkins M. , Leach M. O. , Atkinson D. 
Published: May 2009

AbstractThis article presents a method to reconstruct liver MRI data acquired continuously during free breathing, without any external sensor or navigator measurements. When the deformations associated with k‐space data are known, generalized matrix inversion reconstruction has been shown to be effective in reducing the ghosting and blurring artifacts of motion. This article describes a novel method to obtain these nonrigid deformations. A breathing model is built from a fast dynamic series: low spatial resolution images are registered and their deformations parameterized by overall superior–inferior displacement. The correct deformation for each subset of the subsequent imaging data is then found by comparing a few lines of k‐space with the equivalent lines from a deformed reference image while varying the deformation over the model parameter. This procedure is known as image deformation recovery using overlapping partial samples (iDROPS). Simulations using 10 rapid dynamic studies from volunteers showed the average error in iDROPS‐derived deformations within the liver to be 1.43 mm. A further four volunteers were imaged at higher spatial resolution. The complete reconstruction process using data from throughout several breathing cycles was shown to reduce blurring and ghosting in the liver. Retrospective respiratory gating was also demonstrated using the iDROPS parameterization. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Antibiotics taken for other illnesses and spontaneous clearance of Helicobacter pylori infection in children
Authors: Broussard Cheryl S , Goodman Karen J , Phillips Carl V , Smith Mary Ann , Fischbach Lori A , Day R Sue , Aragaki Corinne C 
Published: May 2009

AbstractPurposeFactors that determine persistence of untreated Helicobacter pylori (H. pylori) infection in childhood are not well understood. We estimated risk differences for the effect of incidental antibiotic exposure on the probability of a detected clearance at the next test after an initial detected H. pylori infection.MethodsThe Pasitos Cohort Study (1998–2005) investigated predictors of H. pylori infection in children from El Paso, Texas, and Juarez, Mexico. Children were screened for infection at 6‐month target intervals from 6 to 84 months of age, using the 13C‐urea breath test corrected for body‐size‐dependent variation in CO2 production. Exposure was defined as courses of any systemic antibiotic (systemic) or those with anti‐H. pylori action (HP‐effective) reported for the interval between initial detected infection and next test. Binomial regression models included country of residence, mother's education, adequacy of prenatal care, age at infection, and interval between tests.ResultsOf 205 children with a test result and antibiotic data following a detected infection, the number of children who took ≥1 course in the interval between tests was 74 for systemic and 33 for HP‐effective. The proportion testing negative at the next test was 66% for 0 courses, 72% for ≥1 systemic course, and 79% for ≥1 HP‐effective course. Adjusted risk differences (95%CI) for apparent clearance, comparing ≥1 to 0 courses were 10% (1–20%) for systemic and 11% (0–21%) for HP‐effective.ConclusionsIncidental antibiotic exposure appears to influence the duration of childhood H. pylori infection but seems to explain only a small portion of spontaneous clearance. Copyright © 2009 John Wiley & Sons, Ltd.
Dimensional stability of single‐site ethylene copolymers in rotational molding
Authors: Bellehumeur C.T. , Medina A. , Xu H. 
Published: May 2009

AbstractThe dimensional stability of ethylene copolymers in rotational molding was studied by comparing the warpage observed for a series of conventional and single‐site catalyzed ethylene copolymers. Bench‐scale molding trials were carried out under controlled molding conditions. The rapid cooling of the mold using a water spray resulted in greater warpage. Under such conditions, molded parts made using the single‐site resins showed less warpage compared to the Ziegler‐catalyzed copolymers with otherwise comparable densities. The Ziegler‐catalyzed copolymers were characterized by a faster crystallization rate, and were shown to generate larger crystallinity gradients through the part thickness during the cooling process. Second to temperature gradients, crystallinity gradients are a leading cause for the development of residual stresses and causing warpage. Differences in the crystallization rates between single‐site and Ziegler‐catalyzed copolymers are discussed based on their intermolecular comonomer distributions. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Comparison of orbital and linear vibration welding of thermoplastics
Authors: Grewell David A. , Benatar Avraham 
Published: May 2009

AbstractThis work was conducted to determine if there were any benefits with orbital vibration welding compared to linear vibration welding. The experiments were conducted using standard full‐factorial designs with each process and each material. Four materials, polypropylene/polyethylene copolymer (PP/PE), polycarbonate (PC), acrylonitrile‐butadiene‐styrene (ABS) and Nylon (PA), were studied with each process. The equipment used was a modified Branson VW‐4 with an orbital head that had isolated magnets. The same machine was used to weld with both linear and orbital motions. This was achieved by modifying the controlling parameters of the drive. It was found that compared to linear vibration welding, orbital welding had a reduction of cycle time by 36% and 50% in Phase I and Phase III, respectively. It was also found that orbital welding dissipated 56% and 100% more power than linear vibration welding in Phase I and Phase III, respectively. In addition, it was seen that orbital welding was able to universally join unsupported walls with higher strengths and better consistency compared to linear welding. Other benefits included: a difference in the appearance of weld flash and small increase in weld strength. Some of the limitations of orbital welding that were identified included the effects of disengagement and residual stresses. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
An innovative method of die design and evaluation of flow balance for thermoplastics extrusion profiles
Authors: Zolfaghari Abbas , Behravesh Amir Hossein , Shakouri Ehsan , Soury Ehsan 
Published: May 2009

AbstractIn this article, a computational and experimental method for flow balancing of a U‐shaped die profile with nonuniform thicknesses is presented. The approach was to implement a flow restricting mechanism along the melt flow path. A parametric study based on the restrictor dimensions was carried out to attain a preliminary optimal design. Simulations were performed using Fluent software to analyze the flow velocity at the die exit. Experimental study was then carried out at various restrictor positions for the purpose of attaining a desirable flow balance. The velocity at various segments of the die exit was measured utilizing an innovative procedure by implementing the “separating blades.” Experimental findings were compared with those of simulations which showed an acceptable agreement. The results suggest that a flexible die can be designed to achieve a flow balance under various processing conditions. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Ground temperatures in permafrost south of treeline, Mackenzie Delta, Northwest Territories
Authors: Kanigan J. C. N. , Burn C. R. , Kokelj S. V. 
Published: May 2009

AbstractSurface conditions and ground temperatures from 50‐cm to 20‐m depth were measured at 26 forested sites in the Mackenzie Delta, to determine if differences in forest structure and organic cover between four common white spruce forest community types were associated with variations in ground temperature. The mean annual temperature at 1‐m depth was lowest (−4.4°C) in the closed/spruce‐feathermoss (CSF) community associated with a thick canopy and thin snow cover, and highest in the recent permafrost of the spruce/alder‐bearberry (SAB) community (−1.0°C) with an open canopy and deep snow. The open‐canopy spruce/crowberry‐lichen (SCL) forest, with a thick surface organic cover and deep snow, had a higher mean annual temperature at 1‐m depth (−2.1°C) than the CSF forest, indicating the importance of canopy cover for snow accumulation and ground heat loss in winter. Seasonal and inter‐annual variation of 4‐m ground temperatures was greatest beneath the CSF community, highlighting the importance of greater winter cooling due to a thin snow cover and a lower unfrozen water content. Temperatures at 20‐m depth ranged from −0.6°C to −1.5°C in SAB forests, and were significantly lower in CSF, open/spruce‐feathermoss and SCL communities (−1.6°C to −2.9°C). Variation in near‐surface temperatures between spruce forest types diminishes with depth due to the thermal influence of water bodies. There was no significant variation of ground temperatures at 20‐m depth within spruce forest communities in different parts of the delta. Copyright © 2009 John Wiley & Sons, Ltd. and Her Majesty the Queen in right of Canada.
Stratigraphy and palaeoenvironments of Richards Island and the eastern Beaufort Continental Shelf during the last glacial‐interglacial cycle
Authors: Murton Julian B. 
Published: May 2009

AbstractThe Pleistocene lithostratigraphy exposed on northern Richards Island comprises seven units that correlate with the offshore seismostratigraphy of the eastern Beaufort Continental Shelf. Land‐sea correlations, cryostratigraphic observations and proxy indicators of environmental change provide a record of palaeoenvironmental history that commences before the last glacial‐interglacial cycle. After the high sea‐level stand of the Last (Sangamonian) Interglaciation, marine regression exposed a large area of the eastern Beaufort Shelf to cold subaerial conditions and permafrost aggradation. Northward progradation of a braided river system was abruptly replaced by aeolian activity, probably as a result of diversion of the palaeo‐Porcupine River by the advancing Laurentide Ice Sheet during the Late Wisconsinan. Glaciation of Richards Island by the Mackenzie palaeo‐ice stream was brief (sometime between ∼22 000 and 16 000 cal. yr BP), and deglaciation had certainly commenced by 14 300 cal. yr BP and perhaps by ∼16 000 cal. yr BP or earlier. Major fluvial erosion during the Last Glacial‐Interglacial Transition incised cross‐shelf valleys and formed a regional erosion surface. The Holocene marine transgression trimmed some of the erosion surface and offshore, covered it with marine deposits. Copyright © 2009 John Wiley & Sons, Ltd.
Temporal expression profiling of the effects of secreted factors from prostate stromal cells on embryonal carcinoma stem cells
Authors: Pascal Laura E. , Vêncio Ricardo Z.N. , Goo Young Ah , Page Laura S. , Shadle Christina P. , Liu Alvin Y. 
Published: May 2009

AbstractBACKGROUNDThere is a growing body of evidence indicating that epigenetic influences originating from stromal cells in the immediate microenvironment may play a role in carcinogenesis. Determining the molecular mechanisms involved in stromal–stem cell interaction could provide critical insight into prostate development and disease progression, particularly with regard to their relationship to and influence on the putative cancer stem cell.METHODSProstate and bladder stromal cells prepared from tissue specimens were co‐cultured with the pluripotent embryonal carcinoma cell line NCCIT. Transcriptome analysis was used to characterize NCCIT cell response to prostate or bladder signaling.RESULTSA systems approach demonstrated that prostate stromal cells were capable of inducing gene expression changes in NCCIT through secreted factors. Induction led to a loss of embryonic stem cell markers, with concurrent up‐regulation of many genes characteristic of stromal mesenchyme cells as well as some of epithelial and cancer stem cells. Bladder stromal signaling produced gene expression changes different from those of prostate signaling.CONCLUSIONSThis study indicates that paracrine stromal cell signaling can affect cancer stem cell response in an organ‐specific manner and may provide insight for future development of treatment strategies such as differentiation therapy. Prostate 69:1353–1365, 2009. © 2009 Wiley‐Liss, Inc.
Tuning the orthorhombic–rhombohedral phase transition temperature in sodium potassium niobate by incorporating barium zirconate
Authors: Wang Ruiping , Bando Hiroshi , Katsumata Tetsuhiro , Inaguma Yoshiyuki , Taniguchi Hiroki , Itoh Mitsuru 
Published: May 2009

AbstractWe report that the orthorhombic–rhombohedral phase transition temperature in sodium potassium niobate could be tuned from lower to higher than room temperature by incorporating barium zirconate into it. It is revealed that when barium zirconate is between 8 mol% and 15 mol%, the solid solution exhibits rhombohedral symmetry at room temperature. Rietveld analysis shows that the space group of the rhombohedral phase is R3m. It is suggested that a relatively larger B‐cation favors the low‐temperature phase which is a common phenomenon for perovskite ferroelectrics. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Glabridin inhibits lipopolysaccharide‐induced activation of a microglial cell line, BV‐2, by blocking NF‐κB and AP‐1
Authors: Park Sun Hong , Kang Jong Soon , Yoon Yeo Dae , Lee Kiho , Kim Kang‐Jeon , Lee Ki Hoon , Lee Chang Woo , Moon Eun‐Yi , Han Sang‐Bae , Kim Bong Hee , Kim Hwan Mook , Park Song‐Kyu 
Published: May 2009

AbstractGlabridin, a flavonoid present in licorice root, is known to have antiinflammatory and cardiovascular protective activities. The present study reports an inhibitory effect of glabridin on microglial activation. Glabridin dose‐dependently attenuated lipopolysaccharide (LPS)‐induced production of inflammatory mediators, including nitric oxide, tumor necrosis factor‐α and interleukin‐1β, in BV‐2 cells, a murine microglia cell line. Moreover, mRNA expression of these inflammatory mediators was also suppressed by glabridin in LPS‐stimulated BV‐2 cells. Further study demonstrated that glabridin inhibited LPS‐induced DNA binding activity of NF‐κB and AP‐1 in BV‐2 cells. Collectively, the results presented in this report demonstrate that glabridin inhibits the production of inflammatory mediators in BV‐2 cells and this is mediated, at least in part, by blocking NF‐κB and AP‐1 activation. The results suggest that glabridin might be a potential therapeutic agent for the treatment of neuroinflammatory and neurodegenerative diseases. Copyright © 2009 John Wiley & Sons, Ltd.
Orbital‐dependent magnetic properties of molecular cluster containing high‐spin Co(II) ions
Authors: Wang Fan , Zhao Fei , Wang Bing‐Wu , Wang Ming‐Wei , Zhang Yuan‐Zhu , Wang Wei , Gao Song , Chen Zhi‐Da 
Published: May 2009

AbstractTo shed light on magnetic properties of the magnetic exchange molecular cluster containing the constituent metal ion with unquenched orbital angular momentum, as representative examples two octahedrally coordinated high‐spin Co(II)‐cluster complexes were synthesized and characterized: complex (1) [Co3(Hbzp)6][ClO4]2· 2CH3OH·H2O (bzp = 2‐benzoylpyridine) with a linear core Co(III)‐Co(II)‐Co(III) and complex (2) [Co4L(N3)4(CH3CN)4](ClO4)4·2H2O (L = Macrocyclic schiff base of tetra‐2,6‐pyridinedicarboxaldehyde‐tetra‐ethane‐1,2‐diamine) comprised by two nearly independent Co(II)‐dimers. Following Lines' isotropic exchange approximation the magnetic interaction effective Hamiltonian was introduced, which includes the exchange interactions, the spin‐orbit coupling, the low‐symmetry crystal field, and the intercluster exchange interaction. On the basis of the irreducible tensor operator approach to solve Hamiltonian we have coded the software, BJMAG package, and performed the best‐fit procedure for experimentally temperature variable magnetic susceptibilities for the complexes (1) and (2). The best‐fit parameters were obtained as follows: λ = −126 cm−1, Δ = 432 cm−1, κ = 0.96, mJ′ = 2.7 cm−1 for the complex (1) and λ = −165 cm−1, Δ = 960 cm−1, κ = 0.95, J′ = 9 cm−1, mJ′ = −0.1 cm−1 for the complex (2). To further elucidate the individual role of each interaction in the employed model, the effects of the key factors governing the magnetic properties on temperature variable magnetic susceptibilities were examined in detail. The significance of the intercluster exchange interactions at low temperatures was briefly discussed and a self‐consistent molecular field to calculate the thermally average spin of the nearest neighbor in the intercluster interaction was proposed. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
The biophysical basis of Benveniste experiments: Entropy, structure, and information in water
Authors: Widom Allan , Srivastava Yogendra , Valenzi Vincenzo 
Published: May 2009

AbstractBenveniste had observed that highly dilute (and even in the absence of physical molecules) biological agents still triggered relevant biological systems. Some of these experiments were reproduced in three other laboratories who cosigned the article, (Davenas et al., Nature 1988, 333, 816). Further works, [(Medical Hypotheses 2000, 54, 33), (Rivista di Biologia/Biology Forum 97, 2004, 169)], showed that molecular activity in more than 50 biochemical systems and even in bacteria could be induced by electromagnetic signals transferred through water solutes. The sources of the electromagnetic signals were recordings of specific biological activities. These results suggest that electromagnetic transmission of biochemical information can be stored in the electric dipole moments of water in close analogy to the manner in which magnetic moments store information on a computer disk. The electromagnetic transmission would enable in vivo transmissions of the specific molecular information between two functional biomolecules. In the present work, the physical nature of such biological information storage and retrieval in ordered quantum electromagnetic domains of water will be discussed. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Energetics of 1,n‐didehydro‐polyene diradicals and performance of reduced multireference coupled‐cluster method
Authors: Li Xiangzhu , Paldus Josef 
Published: May 2009

AbstractThe reduced multireference coupled‐cluster method with singles and doubles (RMR CCSD) and its RMR CCSD(T) version are employed to study the energetics of 1,n‐didehydro‐polyenes. The RMR CCSD method accounts for quasi‐degeneracy by exploiting a multireference (MR) CISD wave function as an external source of the most important (primary) triples and quadruples while the subsequent perturbative correction for the secondary triples leads to RMR CCSD(T). The resulting energies are compared with those yielded by the standard single‐reference (SR) CCSD and CCSD(T) approaches. We first determine the optimal geometry for each species considered. Using the CC methods just mentioned we then compute the energy of the lowest‐lying singlet and triplet states, the implied singlet‐triplet splitting, and determine the spin multiplicity of the ground state. We point out the relationship between the degree of the diradical character, the extent of quasi‐degeneracy or the MR nature of the state considered, the distance separating the radical centers and, finally, the size of the largest doubly excited cluster amplitude in the CC wave functions. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Unusual low‐intensity regime in laser‐induced molecular photodissociation
Authors: Lefebvre R. , Atabek O. 
Published: May 2009

AbstractPrevious investigations of laser‐induced photodissociation of a diatomic molecule (Atabek et al., Phys Rev A 2006, 74, 063412 and Atabek and Lefebvre, Phys Rev A 2008, 78, 043419) have shown that some of the Floquet eigenstates have the property that at some critical intensities their width is vanishing. These intensities are wavelength dependent. We exploit further this property by showing that by a proper choice of the wavelength, the critical intensity for a Floquet state originating from a given field‐free vibrational state can be made vanishingly small. In such a case, the rate increases with intensity in an abnormally slow way. The wavelengths, which are required to reach this regime, can be derived accurately from the semiclassical criterion to obtain a zero‐width resonance. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009