bluuebunny/crossref_metadata_2025_split huggingface dataset:
SIMPLE‐type preconditioners for the Oseen problem
Authors: ur Rehman M. , Vuik C. , Segal G. 
Published: November 2008

AbstractIn this paper, the steady incompressible Navier–Stokes equations are discretized by the finite element method. The resulting systems of equations are solved by preconditioned Krylov subspace methods. Some new preconditioning strategies, both algebraic and problem dependent are discussed. We emphasize on the approximation of the Schur complement as used in semi implicit method for pressure‐linked equations‐type preconditioners. In the usual formulation, the Schur complement matrix and updates use scaling with the diagonal of the convection–diffusion matrix. We propose a variant of the SIMPLER preconditioner. Instead of using the diagonal of the convection–diffusion matrix, we scale the Schur complement and updates with the diagonal of the velocity mass matrix. This variant is called modified SIMPLER (MSIMPLER). With the new approximation, we observe a drastic improvement in convergence for large problems. MSIMPLER shows better convergence than the well‐known least‐squares commutator preconditioner which is also based on the diagonal of the velocity mass matrix. Copyright © 2008 John Wiley & Sons, Ltd.
Identification of a potential “hotspot” DNA region in the RUNX1 gene targeted by mitoxantrone in therapy‐related acute myeloid leukemia with t(16;21) translocation
Authors: Ottone Tiziana , Hasan Syed Khizer , Montefusco Enrico , Curzi Paola , Mays Ashley N. , Chessa Luciana , Ferrari Antonella , Conte Esmeralda , Noguera Nelida Inés , Lavorgna Serena , Ammatuna Emanuele , Divona Mariadomenica , Bovetti Katia , Amadori Sergio , Grimwade David , Lo‐Coco Francesco 
Published: November 2008

AbstractThe translocation t(16;21) involving RUNX1 (AML1) and resulting in the RUNX1‐CBFA2T3 fusion is a rare but recurrent abnormality mostly found in therapy‐related acute myeloid leukemia (t‐AML) associated with agents targeting topoisomerase II (topo II). We characterized, at the genomic level, the t(16;21) translocation in a patient who developed t‐AML after treatment of multiple sclerosis with mitoxantrone (MTZ). Long template nested PCR of genomic DNA followed by direct sequencing enabled the localization of RUNX1 and CBFA2T3 (ETO2) breakpoints in introns 5 and 3, respectively. Sequencing of the cDNA with specific primers showed the presence of the expected RUNX1‐CBFA2T3 fusion transcript in leukemic cells. The RUNX1 intron 5 breakpoint was located at nucleotide position 24,785. This region contained an ATGCCCCAG nucleotide sequence showing ∼90% homology to a “hotspot” DNA region ATGCCCTAG present in intron 6 of PML previously identified in therapy‐related acute promyelocytic leukemia cases arising following treatment with MTZ. This study suggests a wider distribution in the human genome, and particularly at genes involved in chromosome translocations observed in t‐AML, of DNA regions (hotspot) targeted by specific topo II drugs. © 2008 Wiley‐Liss, Inc.
An FGF‐responsive astrocyte precursor isolated from the neonatal forebrain
Authors: Lin Grace , Goldman James E. 
Published: November 2008

AbstractGliogenesis in the mammalian CNS continues after birth, with astrocytes being generated well into the first two postnatal weeks. In this study, we have isolated an A2B5+ astrocyte precursor (APC) from the postnatal rat forebrain, which is capable of differentiating into mature astrocytes in serum‐free medium without further trophic support. Exposure to basic fibroblast growth factor (bFGF) selectively induces the APCs to proliferate, forming clusters of vimentin+ cells, which, within 2 weeks, differentiate into GFAP+ astrocytes. While bFGF functions as a potent mitogen, neither is it necessary to induce or maintain astrocyte differentiation, nor is it capable of maintaining the precursors in an immature, proliferative state. APCs exit the cell cycle and differentiate, even in the continued presence of fibroblast growth factor alone or in combination with other mitogenic factors such as platelet‐derived growth factor. Under the culture conditions used, it was not possible to cause the astrocytes to re‐enter cell cycle. After transplantation into the neonatal forebrain, APCs differentiated exclusively into astrocytes, regardless of brain region. Initially distributed widely within the forebrain, the precursors are most greatly concentrated within the subventricular zone (SVZ) and subcortical white matter, where they are maintained throughout postnatal development. APCs can be isolated from the SVZ and white matter of animals as late as 4 weeks after birth. © 2008 Wiley‐Liss, Inc.
Sigma receptors suppress multiple aspects of microglial activation
Authors: Hall Aaron A. , Herrera Yelenis , Ajmo Craig T. , Cuevas Javier , Pennypacker Keith R. 
Published: November 2008

AbstractDuring brain injury, microglia become activated and migrate to areas of degenerating neurons. These microglia release proinflammatory cytokines and reactive oxygen species causing additional neuronal death. Microglia express high levels of sigma receptors, however, the function of these receptors in microglia and how they may affect the activation of these cells remain poorly understood. Using primary rat microglial cultures, it was found that sigma receptor activation suppresses the ability of microglia to rearrange their actin cytoskeleton, migrate, and release cytokines in response to the activators adenosine triphosphate (ATP), monocyte chemoattractant protein 1 (MCP‐1), and lipopolysaccharide (LPS). Next, the role of sigma receptors in the regulation of calcium signaling during microglial activation was explored. Calcium fluorometry experiments in vitro show that stimulation of sigma receptors suppressed both transient and sustained intracellular calcium elevations associated with the microglial response to these activators. Further experiments showed that sigma receptors suppress microglial activation by interfering with increases in intracellular calcium. In addition, sigma receptor activation also prevented membrane ruffling in a calcium‐independent manner, indicating that sigma receptors regulate the function of microglia via multiple mechanisms. © 2008 Wiley‐Liss, Inc.
17β‐estradiol and progesterone prevent cuprizone provoked demyelination of corpus callosum in male mice
Authors: Acs Peter , Kipp Markus , Norkute Akvile , Johann Sonja , Clarner Tim , Braun Alena , Berente Zoltan , Komoly Samuel , Beyer Cordian 
Published: November 2008

AbstractSex hormones, for example, estrogen and progesterone, are thought to affect and delay progression of multiple sclerosis (MS) in pregnant women. Although both steroid hormones are neuroprotective in the brain and elevated during pregnancy, only estrogen was tested in clinical trials. To evaluate the role of 17β‐estradiol (E) and progesterone (P) in prevention demyelination, young adult male mice were fed with cuprizone for a defined time interval and simultaneously treated with steroids by repeated injections into the neck region. The status of myelination was analyzed by magnetic resonance imaging and conventional histological staining. The individual application of E and P resulted only in a moderate prevention of demyelination in the corpus callosum (CC). The combined treatment with both steroid hormones counteracted the process of demyelination. Expression of the mature (PLP and MBP) and premature (PDGF‐α‐R) oligodendrocyte markers were significantly increased after hormone application in the affected CC. In addition, both hormones stimulated astrogliosis and the expression of IGF‐1. Microglial invasion in demyelinated CC was pronounced and additionally localized in the midline of CC after hormone treatment. These data show that sex steroids can protect the brain from demyelination and stimulate remyelination. It appears that only the administration of both hormones is fully effective. The beneficial steroid effect requires interactions with oligodendrocytes possibly by preventing their degeneration or recruitment from precursor cells which are stimulated to remyelinated fibers. The positive hormonal influence on myelination in the CNS may be a future therapeutically strategy for the treatment of MS. © 2008 Wiley‐Liss, Inc.
Astrocytic calcium signals induced by neuromodulators via functional metabotropic receptors in the ventral respiratory group of neonatal mice
Authors: Härtel Kai , Schnell Christian , Hülsmann Swen 
Published: November 2008

AbstractA controlled, periodic exchange of air between lungs and atmosphere requires a neuronal rhythm generated by a network of neurons in the ventral respiratory group (VRG) of the brainstem. Glial cells, e.g. astrocytes, have been shown to be supportive in stabilizing this neuronal activity in the central nervous system during development. In addition, a variety of neuromodulators including serotonin (5‐HT), Substance P (SP), and thyrotropin‐releasing hormone (TRH) stimulate respiratory neurons directly. If astrocytes in the VRG, like their neuronal neighbors, are also directly stimulated by neuromodulators, they might indirectly affect the respiratory neurons and consequently the respiratory rhythm. In the present study, we provide support for this concept by demonstrating expression of NK1‐R, TRH‐R, and 5‐HT2‐R in astrocytes of the VRG with immunohistochemistry. Additionally, we showed that the external application of the neuromodulators 5‐HT, SP, and TRH activate calcium transients in VRG astrocytes. Consequently, we postulate that in the VRG of the neonatal mouse, neuromodulation by SP, TRH, and serotonin also involves astrocytic calcium signaling. © 2008 Wiley‐Liss, Inc.
Neurodevelopmental impairment: Predictors of its impact on the families of extremely low birth weight infants at 18 months
Authors: Stephens Bonnie E. , Bann Carla M. , Poole W. Kenneth , Vohr Betty R. 
Published: November 2008

AbstractEffects on a family of a child with chronic illness have been described. The Impact on Family Scale (IOF) was developed to measure these effects. The impact of extremely low birth weight (ELBW) infants with neurodevelopmental impairment on families is unknown. This study determined IOF scores for families of ELBW infants with increasing degree of impairment at 18 months and identified factors that increase vulnerability to impact. A total of 3,849 ELBW infant survivors born at the 16 centers of the National Institute of Child Health and Human Development Neonatal Research Network between January 1993 and February 2001 were assessed at 18 to 22 months. Infants were divided into four groups by degree of impairment. IOF scores were analyzed by impairment group. Multivariate analyses assessed effects of impairment, social/demographic factors, unmet service needs, and resource utilization on the IOF. A total of 1,624 (42.2%) infants had moderate/severe impairment. Increasing severity of impairment was associated with higher IOF scores. Severity of impairment contributed 6% of variance to the IOF scores. Twenty‐one percent of variance was contributed by additional medical needs, low socioeconomic status (SES), and lack of social support. Although increasing severity of impairment impacts families of ELBW infants, significantly more impact is contributed by additional medical needs, low SES, and lack of social support.
On the basis‐set dependence of local and integrated electron density properties: Application of a new computer program for quantum‐chemical density analysis
Authors: Volkov Anatoliy , Koritsanszky Tibor , Chodkiewicz Michal , King Harry F. 
Published: November 2008

AbstractA new computer program for post‐processing analysis of quantum‐chemical electron densities is described. The code can work with Slater‐ and Gaussian‐type basis functions of arbitrary angular momentum. It has been applied to explore the basis‐set dependence of the electron density and its Laplacian in terms of local and integrated topological properties. Our analysis, including Gaussian/Slater basis sets up to sextuple/quadruple‐zeta order, shows that these properties considerably depend on the choice of type and number of primitives utilized in the wavefunction expansion. Basis sets with high angular momentum (l= 5 orl= 6) are necessary to achieve convergence for local properties of the density and the Laplacian. In agreement with previous studies, atomic charges defined within Bader's Quantum Theory of Atoms in Molecules appear to be much more basis‐set dependent than the Hirshfeld's stockholder charges. The former ones converge only at the quadruple‐zeta/higher level with Gaussian/Slater functions. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2009
Apoptotic endothelial cells demonstrate increased adhesiveness for human mesenchymal stem cells
Authors: Potapova Irina A. , Cohen Ira S. , Doronin Sergey V. 
Published: November 2008

AbstractMesenchymal stem cells (MSCs) participate in the wound healing process in mammalians. Adhesion of MSCs to endothelium is a key step in the homing of MSCs circulating in the bloodstream to the sites of injury and inflammation. Because endothelial cells (ECs) may become apoptotic under certain pro‐inflammatory conditions, we investigated the effects of pro‐inflammatory, TNF‐α and IL‐1β, and pro‐apoptotic agents, actinomycin D, cycloheximide, okadaic acid, wortmannin, and staurosporine, on human MSCs (hMSCs) adhesion to ECs. Treatment of ECs with pro‐apoptotic agents markedly increased adhesion of hMSCs to ECs. This adhesion correlated with reduction of mitochondrial membrane potential, inhibition of NADH dehydrogenases, and release of von Willebrand factor (vWF) by ECs. Treatment of ECs with exogenous vWF also stimulated hMSC adhesion. These data provide evidence that apoptosis of ECs may regulate homing of hMSCs to the sites of tissue injury. These results are consistent with the hypothesis that activation of apoptotic signaling pathways in ECs releases vWF which regulates hMSC adhesion to ECs. J. Cell. Physiol. 219: 23–30, 2009. © 2008 Wiley‐Liss, Inc.
Trends in the start of the wet season over Africa
Authors: Kniveton D. R. , Layberry R. , Williams C. J. R. , Peck Mika 
Published: November 2008

AbstractA quarter of a century of daily rainfall data from the Global Telecommunications System are used to define the temporal and spatial variability of the start of the wet season over Africa and surrounding extreme south of Europe and parts of the Middle East. From 1978 to 2002, the start of the wet season arrived later in the year for the majority of the region, as time progressed. In some parts of the continent, there was an annual increase in the start date of up to 4 days per year. On average, the start of the wet season arrived 9–21 days later from 1978 to 2002, depending on the threshold used to define the start of the rains (varying from 10–30 mm over 2 days, with no dry period in the following 10 days). It is noted that the inter‐annual variability of the start of the wet season is high with the range of start dates varying on average from 116 to 142 days dependent on the threshold used to determine the start date. These results may have important implications for agriculturists on all levels (from the individual farmer to those responsible for regional food supply), as knowledge of potential future climate changes starts to play an increasingly important role in the agricultural decision‐making process, such as sowing and harvesting times. Copyright © 2008 Royal Meteorological Society
Distally based sural fasciomyocutaneous flap: Anatomic study and modified technique for complicated wounds of the lower third leg and weight bearing heel
Authors: Chang Shi‐Min , Zhang Kai , Li Hai‐Feng , Huang Yi‐Gang , Zhou Jia‐Qian , Yuan Feng , Yu Guang‐Rong 
Published: November 2008

AbstractThe reconstruction of the distal third leg and weight‐bearing heel, especially when complicated with infection and/or dead space, remains a challenge in reconstructive surgery. The distally based sural neurofasciomyocutaneous flap has been proved a valuable tool in repair of the soft tissue defects of those areas. In this report, we present the results of the anatomical study on vascular communication between the suprafascial sural neurovascular axis and the deep gastrocnemius muscle and a modified technique in clinical applications for reconstruction of the soft tissue defects in the distal lower leg and heel. Six lower limbs of fresh cadavers were injected with red gelatin and dissected. A constant vascular connection with average four musculo‐fasciocutaneous perforators with diameter 0.2–0.5 mm was identified in the overlapping area between the suprafascial sural neurovascular axis and the deep gastrocnemius muscle. Based on these findings, a modified distally based sural neurofasciomyocutaneous flap including the distal gastrocnemius muscle component was designed and used for repairs of the soft tissue defects in the distal lower limb and plantar heel pad in six patients. The blood supplies of flaps comprised either the peroneal perforator and adipofascial pedicle or the peroneal perforator only. The average size of the fasciocutaneous flap was 51 cm2, and the muscle component 17.7 cm2. All flaps survived uneventfully. Our results suggest that this technical modification could provide wider range for applications of the distally based sural neurofasciomyocutaneous flap in repair of the soft tissue defects of the lower extremity and heel. © 2008 Wiley‐Liss, Inc. Microsurgery, 2009.
Determination of the Robin coefficient in a nonlinear boundary condition for a steady‐state problem
Authors: Slodička Marián , Lesnic Daniel 
Published: November 2008

AbstractIn this paper, a constant heat transfer coefficient present in a nonlinear Robin‐type boundary condition associated with an elliptic equation is reconstructed uniquely from a single boundary energy measurement. Two types of such boundary energy measurement are considered, and solvability theorems for the solution of the resulting nonlinear inverse problems are provided. Further, one‐dimensional numerical results are presented and discussed. Copyright © 2008 John Wiley & Sons, Ltd.
On an initial‐boundary value problem for a wide‐angle parabolic equation in a waveguide with a variable bottom
Authors: Dougalis V. A. , Sturm F. , Zouraris G. E. 
Published: November 2008

AbstractWe consider the third‐order Claerbout‐type wide‐angle parabolic equation (PE) of underwater acoustics in a cylindrically symmetric medium consisting of water over a soft bottom B of range‐dependent topography. There is strong indication that the initial‐boundary value problem for this equation with just a homogeneous Dirichlet boundary condition posed on B may not be well‐posed, for example when B is downsloping. We impose, in addition to the above, another homogeneous, second‐order boundary condition, derived by assuming that the standard (narrow‐angle) PE holds on B, and establish a priori H2 estimates for the solution of the resulting initial‐boundary value problem for any bottom topography. After a change of the depth variable that makes B horizontal, we discretize the transformed problem by a second‐order accurate finite difference scheme and show, in the case of upsloping and downsloping wedge‐type domains, that the new model gives stable and accurate results. We also present an alternative set of boundary conditions that make the problem exactly energy conserving; one of these conditions may be viewed as a generalization of the Abrahamsson–Kreiss boundary condition in the wide‐angle case. Copyright © 2008 John Wiley & Sons, Ltd.
Blood–spinal cord barrier permeability in experimental spinal cord injury: dynamic contrast‐enhanced MRI
Authors: Cohen David M. , Patel Chirag B. , Ahobila‐Vajjula Pallavi , Sundberg Laura M. , Chacko Tessy , Liu Shi‐Jie , Narayana Ponnada A. 
Published: November 2008

AbstractAfter a primary traumatic injury, spinal cord tissue undergoes a series of pathobiological changes, including compromised blood–spinal cord barrier (BSCB) integrity. These vascular changes occur over both time and space. In an experimental model of spinal cord injury (SCI), longitudinal dynamic contrast‐enhanced MRI (DCE‐MRI) studies were performed up to 56 days after SCI to quantify spatial and temporal changes in the BSCB permeability in tissue that did not show any visible enhancement on the post‐contrast MRI (non‐enhancing tissue). DCE‐MRI data were analyzed using a two‐compartment pharmacokinetic model. These studies demonstrate gradual restoration of BSCB with post‐SCI time. However, on the basis of DCE‐MRI, and confirmed by immunohistochemistry, the BSCB remained compromised even at 56 days after SCI. In addition, open‐field locomotion was evaluated using the 21‐point Basso–Beattie–Bresnahan scale. A significant correlation between decreased BSCB permeability and improved locomotor recovery was observed. Copyright © 2008 John Wiley & Sons, Ltd.
Error estimation and adaptivity for discontinuous failure
Authors: Pannachet T. , Sluys L. J. , Askes H. 
Published: November 2008

AbstractDiscontinuous failure is simulated via the introduction of a geometrical discontinuity. The cohesive zone is modelled via the use of the partition‐of‐unity property of the finite element interpolation. By this approach, a crack can pass through the elements without any restriction to the underlying mesh. Despite such a feature, it has been confirmed that a sufficiently fine mesh discretization still needs to be ensured in order to obtain a correct crack path and mechanical response. The p‐adaptive scheme, driven by error in an energy norm measure or a goal‐oriented measure, has been examined due to its implementational simplicity. The results have shown that, if considering only increasing the polynomial degree, the p‐approach can greatly improve the results. Copyright © 2008 John Wiley & Sons, Ltd.
Comparative proteome profiling of MCF10A and 184A1 human breast epithelial cells emphasized involvement of CDK4 and cyclin D3 in cell proliferation
Authors: Bhaskaran Nimesh , Lin Kah Wai , Gautier Aude , Woksepp Hanna , Hellman Ulf , Souchelnytskyi Serhiy 
Published: November 2008

AbstractAcquiring high proliferation rate is crucial for carcinogenic transformation of cells. We report here proteome profiling of human breast epithelial cells with low (184A1) and high (MCF10A) proliferation rates. We identified 183 proteins in 184A1 and 318 proteins in MCF10A cells. These datasets provide the most comprehensive proteome annotations of 184A1 and MCF10A cells. Proteins were taken for identification from 2‐D gels in a systematic and unbiased way. Functional clustering of the identified proteins showed similarities in distribution of proteins to the same functional domains, indicating similarities in proteomes of 184A1 and MCF10A cells. Among observed differences in protein expression, we validated correlation of expression of endogenous cyclin‐dependent kinase 4 (CDK4), cyclin D3, cdc25B, and p38γ with cell proliferation. Furthermore, down‐regulation of CDK4 and cyclin D3 with specific siRNA inhibited cell proliferation, which emphasized the role of CDK4 and cyclin D3 in enhancement of cell proliferation rate of human breast epithelial cells.
Mass spectrometry in clinical proteomics – from the present to the future
Authors: Palmblad Magnus , Tiss Ali , Cramer Rainer 
Published: November 2008

AbstractMS is an important analytical tool in clinical proteomics, primarily in the disease‐specific discovery, identification and characterisation of proteomic biomarkers and patterns. MS‐based proteomics is increasingly used in clinical validation and diagnostic method development. The latter departs from the typical application of MS‐based proteomics by exchanging some of the high performance of analysis for the throughput, robustness and simplicity required for clinical diagnostics. Although conventional MS‐based proteomics has become an important field in clinical applications, some of the most recent MS technologies have not yet been extensively applied in clinical proteomics. In this review, we will describe the current state of MS in clinical proteomics and look to the future of this field.