bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nanostructures and Functionalities in Polymer Thin Films
Authors: Stamm Manfred , Minko Sergiy , Tokarev Igor , Fahmi Amir , Usov Denys 
Published: September 2004

AbstractSeveral examples of self‐organization in thin polymer films are considered for the fabrication of nanopatterned surfaces and nanoscopic objects. Mixed polymer brushes of statistical distribution at the surface, composed of two immiscible polymers covalently bonded to the substrate phase, segregate in the sub‐micrometer scale. Interplay between lateral and perpendicular (sandwich‐like) segregation effects switching behavior of the thin films upon exposure to different environments. The switching between brush morphologies is used for the fabrication of adaptive/responsive surfaces. Fabrication of nano‐domains based on microphase segregation in block‐copolymer systems is used for structures with lateral dimensions as small as 5‐50 nm. The ordered copolymer structures are applied as templates for the fabrication of membranes, nanofibers and nanoparticles.
Strain‐Controlled Tensile Deformation Behavior and Relaxation Properties of Isotactic Poly(1‐butene) and Its Ethylene Copolymers
Authors: Al‐Hussein Mahmoud , Strobl Gert 
Published: September 2004

AbstractThe tensile deformation behaviour of poly(1‐butene) and two of its ethylene copoloymers was studied at room temperature. This was done by investigating true stress‐strain curves at constant strain rates, elastic recovery and stress relaxation properties and in‐situ WAXS patterns during the deformation process. As for a series of semicrystalline polymers in previous studies, a strain‐controlled deformation behaviour was found. The differential compliance, the recovery properties and the stress relaxation curves changed simultaneously at well‐defined points. The strains at which these points occurred along the true stress‐strain remained constant for the different samples despite their different percentage crystallinities. The well‐defined way in which the different samples respond to external stresses complies with the granular substructure of the crystalline lamellae in a semicrystalline polymer.
Short latency afferent inhibition and facilitation in patients with writer's cramp
Authors: Kessler Kirn R. , Ruge Diane , Ilić Tihomir V. , Ziemann Ulf 
Published: September 2004

AbstractPatients with writer's cramp (WC) show abnormalities of sensorimotor integration possibly contributing to their motor deficit. We studied sensorimotor integration by determining short‐latency afferent inhibition (SAI) in 12 WC patients and 10 age‐matched healthy controls. A conditioning electrical median nerve stimulus was followed 14 to 36 msec later by transcranial magnetic stimulation of the contralateral primary motor cortex, and motor evoked potentials (MEP) were recorded from the relaxed or contracting abductor pollicis brevis muscle (APB). SAI was normal in WC but during APB relaxation SAI was followed by abnormal MEP facilitation, which was absent during APB contraction and in the controls. These findings suggest that somatosensory short‐latency inhibitory input into the primary motor cortex is normal in WC, whereas a later excitatory input, which very likely reflects the long‐latency reflex II, is exaggerated. © 2004 Movement Disorder Society
Parkinsonism, FXTAS, and FMR1 premutations
Authors: Toft Mathias , Aasly Jan , Bisceglio Gina , Adler Charles H. , Uitti Ryan J. , Krygowska‐Wajs Anna , Lynch Timothy , Wszolek Zbigniew K. , Farrer Matthew J. 
Published: September 2004

AbstractThe presence of late‐onset neurological symptoms in male carriers of premutation expansions of the fragile X mental retardation 1 (FMR1) gene has been described recently. One of the clinical symptoms in this fragile X–associated tremor/ataxia syndrome (FXTAS) is parkinsonism. To test the possible association between expanded FMR1 alleles and Parkinson's disease (PD), we determined the size of the FMR1 CGG repeat in 414 male cases of clinically diagnosed parkinsonism, the majority of whom had PD. None of our patients had expanded FMR1 repeats within the premutation range (55–200 CGG repeats). Five patients (1.2%) carry intermediate‐size alleles (41–54 CGG repeats). Expansions within the FMR1 gene are not associated with PD in our study. © 2004 Movement Disorder Society
On blow‐up rate for sign‐changing solutions in a convex domain
Authors: Giga Yoshikazu , Matsui Shin'ya , Sasayama Satoshi 
Published: September 2004

AbstractThis paper studies a growth rate of a solution blowing up at time T of the semilinear heat equation ut − Δu − ∣u∣p−1 u=0 in a convex domain D in ℝn with zero‐boundary condition. For a subcritical p ∈ (1,(n+2)/(n−2)) a growth rate estimate ∣u(x,t)∣⩽C(T−t)−1/(p−1), x ∈ D, t ∈ (0,T) is established with C independent of t provided that D is uniformly C2. The estimate applies to sign‐changing solutions. The same estimate has been recently established when D=ℝn by authors. The proof is similar but we need to establish Lh – Lk estimate for a time‐dependent domain because of the presence of the boundary. Copyright © 2004 John Wiley & Sons, Ltd.
Evolution completeness of separable solutions of non‐linear diffusion equations in bounded domains
Authors: Galaktionov V. A. 
Published: September 2004

AbstractAs a basic example, we consider the porous medium equation (m > 1)
equation image

where Ω ⊂ ℝN is a bounded domain with the smooth boundary ∂Ω, and initial data $u_0 \thinspace \varepsilon L^{\infty} \cap L^{1}$. It is well‐known from the 1970s that the PME admits separable solutions $u_{k}(x,t) = t^{-1/(m-1)} \psi_{ k}(x), \, k = 0,1,2,\ldots,$, where each ψk ≠ 0 satisfies a non‐linear elliptic equation $\Delta (|\psi_{ k}|^{m-1} \psi_k)+ 1/(m-1) \psi_k = 0\, in \,\Omega, \psi_{ k} = 0\, on \, \partial \Omega$. Existence of at least a countable subset Φ = {ψk} of such non‐linear eigenfunctions follows from the Lusternik–Schnirel'man variational theory from the 1930s. The first similarity pattern t−1/(m−1)ψ0(x), where ψ0 > 0 in Ω, is known to be asymptotically stable as t → ∞ and attracts all nontrivial solutions with u0 ⩾ 0 (Aronson and Peletier, 1981).We show that if Φ is discrete, then it is evolutionary complete, i.e. describes the asymptotics of arbitrary global solutions of the PME. For m = 1 (the heat equation), the evolution completeness follows from the completeness‐closure of the orthonormal subset Φ = {ψk} of eigenfunctions of the Laplacian Δ in L2. The analysis applies to the perturbed PME and to the p‐Laplacian equations of second and higher order. Copyright © 2004 John Wiley & Sons, Ltd.
Investigation of time‐domain characteristics of thin‐wire antennas
Authors: Li Hui Feng , Chen Zhi Ning , Li Le‐Wei 
Published: September 2004

AbstractIn this paper, the transient response of thin‐wire dipoles is investigated using a time‐domain integral‐equation method. First, an antenna system comprising two straight wire dipoles is numerically analyzed using the direct method and the separation method, and is verified by the measurement. The separation method enables us to consider the transmitting antenna and the receiving antenna separately during the antenna‐system design process. Secondly, the transient response of an antenna excited by pulses with different time duration is investigated. The response strongly depends on the time duration of the pulse. Lastly, the directional characteristics are demonstrated by the gain for dipoles and V‐dipoles. The received pulses by antenna systems composed of V‐dipoles are discussed. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 253–258, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20435
Effects of early seizures on later behavior and epileptogenicity
Authors: Holmes Gregory L. 
Published: September 2004

AbstractBoth clinical and laboratory studies demonstrate that seizures early in life can result in permanent behavioral abnormalities and enhance epileptogenicity. Understanding the critical periods of vulnerability of the developing nervous system to seizure‐induced changes may provide insights into parallel or divergent processes in the development of autism. In experimental rodent models, the consequences of seizures are dependent on age, etiology, seizure duration, and frequency. Recurring seizures in immature rats result in long‐term adverse effects on learning and memory. These behavioral changes are paralleled by changes in brain connectivity, changes in excitatory neurotransmitter receptor distribution, and decreased neurogenesis. These changes occur in the absence of cell loss. Although impaired cognitive function and brain changes have been well‐documented following early‐onset seizures, the mechanisms of seizure‐induced dysfunction remain unclear. MRDD Research Reviews 2004;10:101–105. © 2004 Wiley‐Liss, Inc.
Sleep and arousal mechanisms in experimental epilepsy: Epileptic components of NREM and antiepileptic components of REM sleep
Authors: Shouse M. N. , Scordato J. C. , Farber P. R. 
Published: September 2004

AbstractNeural generators related to different sleep components have different effects on seizure discharge. These sleep‐related systems can provoke seizure discharge propagation during nonrapid eye movement (NREM) sleep and can suppress propagation during REM sleep. Experimental manipulations of discrete physiological components were conducted in feline epilepsy models, mostly in the systemic penicillin epilepsy model of primary generalized epilepsy and the amygdala kindling model of the localization‐related seizure disorder, temporal lobe epilepsy. The sleep–wake state distribution of seizures was quantified before and after discrete lesions, systemic and localized drug administration, and/or photic stimulation, as well as in relation to microdialysis of norepinephrine. We found that (1) neural generators of synchronous EEG oscillations—including tonic background slow waves and phasic “arousal” events (sleep EEG transients such as sleep spindles and k‐complexes)—combine to promote electrographic seizure propagation during NREM and drowsiness, and antigravity muscle tone permits seizure‐related movement; (2) neural generators of asynchronous neuronal discharge patterns reduce electrographic seizures during alert waking and REM sleep, and skeletal motor paralysis blocks seizure‐related movement during REM; (3) there are a number of similarities between amygdala‐kindled kittens and children with Landau–Kleffner Syndrome (LKS) that suggest a link among seizures, sleep disorders, and behavioral abnormalities/regression. MRDD Research Reviews 2004;10:117–121. © 2004 Wiley‐Liss, Inc.
Localization and early time course of TGF‐β1 mRNA expression in dystrophic muscle
Authors: Gosselin Luc E. , Williams Jacqueline E. , Deering Melissa , Brazeau Daniel , Koury Stephen , Martinez Daniel A. 
Published: September 2004

AbstractFibrosis is a common pathological feature observed in muscle from patients with Duchenne muscular dystrophy (DMD). In the dystrophic (mdx) mouse model of DMD, the diaphragm is more severely affected than other skeletal muscles. The level of transforming growth factor‐beta1 (TGF‐β1), an inflammatory cytokine, is significantly elevated in mdx diaphragm. However, little is known about the onset of TGF‐β1 messenger ribonucleic acid (mRNA) expression, or which cells express the mRNA. In this study, we characterized the location and time course of expression of TGF‐β1 mRNA in diaphragm from mdx mice. TGF‐β1 mRNA was significantly elevated in mdx diaphragm at 6 and 9 but not 12 weeks of age, and these changes corresponded with changes in type I collagen mRNA and hydroxyproline concentration. Mononucleated cells localized to areas of fiber necrosis highly expressed the TGF‐β1 transcript in mdx diaphragm. Neutralization of TGF‐β1 by decorin administration resulted in a 40% reduction in the level of diaphragm muscle type I collagen mRNA. These findings support a role for TGF‐β1 during the early stages of fibrogenesis in dystrophic diaphragm muscle. Therapeutic interventions aimed at neutralizing this cytokine may be beneficial in slowing the development of fibrosis in DMD. Muscle Nerve, 2004
Detection of bioradicals by in vivo L‐band electron spin resonance spectrometry
Authors: Fujii Hirotada , Berliner Lawrence J. 
Published: September 2004

AbstractThe applications of in vivo electron paramagnetic resonance (EPR) or electron spin resonance (ESR) spectroscopy have been impressive over a relatively short period despite the many obstacles which had to be overcome, such as dielectric absorption and biodestruction. The loop–gap resonators and modified loop coil systems have emerged as the most suitable resonators for in vivo EPR experiments. This paper briefly discusses instrumental aspects as a prelude to several examples related to the in vivo monitoring and detection of bioradicals. Recent progress in detection of bioradicals induced by drugs or chemicals is discussed with regard to nitrosocompounds, nitric oxide and metals in vivo. A clinical EPR application is also discussed. Copyright © 2004 John Wiley & Sons, Ltd.
Assessment of tumor oxygenation by electron paramagnetic resonance: principles and applications
Authors: Gallez Bernard , Baudelet Christine , Jordan Bénédicte F. 
Published: September 2004

AbstractThis review paper attempts to provide an overview of the principles and techniques that are often termed electron paramagnetic resonance (EPR) oximetry. The paper discusses the potential of such methods and illustrates they have been successfully applied to measure oxygen tension, an essential parameter of the tumor microenvironment. To help the reader understand the motivation for carrying out these measurements, the importance of tumor hypoxia is first discussed: the basic issues of why a tumor is hypoxic, why these hypoxic microenvironments promote processes driving malignant progression and why hypoxia dramatically influences the response of tumors to cytotoxic treatments will be explained. The different methods that have been used to estimate the oxygenation in tumors will be reviewed. To introduce the basics of EPR oximetry, the specificity of in vivo EPR will be discussed by comparing this technique with NMR and MRI. The different types of paramagnetic oxygen sensors will be presented, as well as the methods for recording the information (EPR spectroscopy, EPR imaging, dynamic nuclear polarization). Several applications of EPR for characterizing tumor oxygenation will be illustrated, with a special emphasis on pharmacological interventions that modulate the tumor microenvironment. Finally, the challenges for transposing the method into the clinic will also be discussed. Copyright © 2004 John Wiley & Sons, Ltd.
Protective mechanisms of Pycnogenol® in ethanol‐insulted cerebellar granule cells
Authors: Siler‐Marsiglio Kendra I. , Paiva Michael , Madorsky Irina , Serrano Yahaira , Neeley Andy , Heaton Marieta B. 
Published: September 2004

AbstractPycnogenol® (PYC), a patented combination of bioflavonoids extracted from the bark of French maritime pine (Pinus maritima), inhibits apoptosis and necrosis of developing neurons exposed acutely to ethanol (EtOH). The present study shows that the protective mechanisms of PYC in EtOH‐exposed postnatal day 9 cerebellar granule cells (P9 CGCs) include (1) reduction of reactive oxygen species (ROS) production; (2) counteraction of suppressed copper/zinc superoxide dismutase (Cu/Zn SOD) and glutathione peroxidase/reductase (GSH‐Px/GSSG‐R) system activities; (3) upregulation of Cu/Zn SOD protein expression; (4) mitigation of the EtOH‐mediated exacerbation of catalase (CAT) activity; and, (5) specific binding and inhibition of active caspase‐3. These results indicate that the mechanisms by which PYC antagonizes EtOH‐induced oxidative stress include oxidant scavenging and modulation of endogenous, cellular proteins. Using findings from the present and previous studies, a model delineating the mechanisms of EtOH effects on the system of antioxidant enzymes in developing CGCs is presented. © 2004 Wiley Periodicals, Inc. J Neurobiol, 2004
Prolonged moderate elevation of corticosterone does not affect hippocampal anatomy or cell proliferation rates in mountain chickadees (Poecile gambeli)
Authors: Pravosudov Vladimir V. , Omanska Alicja 
Published: September 2004

AbstractChronic stress and corresponding chronic elevations of glucocorticoid hormones have been widely assumed to have deleterious effects on brain anatomy and functions such as learning and memory. In particular, it has been suggested that chronic elevations of glucocorticoid hormones result in death of hippocampal neurons and in reduced rates of hippocampal neurogenesis. It is not clear, however, if any increase in glucocorticoid levels has negative effects on hippocampal anatomy as many animals regularly maintain moderately elevated levels of glucocrticoids over long periods of time under natural energetically demanding conditions. We used unbiased stereological methods to investigate whether mountain chickadees (Poecile gambeli) implanted for 49 days with continuous time‐release corticosterone pellets, designed to approximately double the baseline corticosterone levels, differed from placebo‐implanted chickadees in their hippocampal anatomy and cell proliferation rates. We found no significant differences between corticosterone and placebo‐implanted birds in either telencephalon volume, volume of the hippocampal formation, or the total number of hippocampal neurons. Cell proliferation rates, measured as the total number of BrdU‐labeled cells in the ventricular zone adjacent either to the hippocampus or to the mesopallium, were also not significantly different between corticosterone and placebo‐implanted chickadees. Our results suggest that prolonged moderate elevation of corticosterone might not provide the suggested deleterious effects on hippocampal anatomy and neurogenesis in food‐caching birds and, as we have shown previously, it actually enhances spatial memory. © 2004 Wiley Periodicals, Inc. J Neurobiol, 2005
Distinct temporal genetic signatures of neurogenic and gliogenic cues in cortical stem cell cultures
Authors: Sauvageot Claire , Dahia Patricia L. , Lipan Ovidiu , Park John K. , Chang Mi‐Sook , Alberta John A. , Stiles Charles D. 
Published: September 2004

AbstractCortical progenitor cells from rat embryos give rise to neurons or glia following exposure to platelet derived growth factor (PDGF) or ciliary neurotrophic factor (CNTF), respectively. Both growth factors impart their developmental cues quickly through a transcription‐dependent mechanism. Do the alternate developmental responses to PDGF and CNTF reflect induction of qualitatively distinct genes? Alternatively, do the same genes respond to each growth factor, but with quantitatively distinct kinetics? Using differential library screening and custom cDNA microarrays we show that a common set of genes responds to either growth factor. However, quantitative differences in the onset and duration of gene induction equate to the expression of factor‐specific gene signatures. Multitissue cluster analysis also reveals tissue‐specific gene signatures that may play important roles in the developing brain. © 2004 Wiley Periodicals, Inc. J Neurobiol, 2005
The endogenous cannabinoid system and its role in nociceptive behavior
Authors: Cravatt Benjamin F. , Lichtman Aron H. 
Published: September 2004

AbstractThe analgesic properties of exogenous cannabinoids have been recognized for many years and suggest a regulatory role for the endogenous cannabinoid (“endocannabinoid”) system in mammalian nociceptive pathways. The endocannabinoid system includes: (1) at least two families of lipid signaling molecules, the N‐acyl ethanolamines (e.g., anandamide) and the monoacylglycerols (e.g., 2‐arachidonoyl glycerol); (2) multiple enzymes involved in the biosynthesis and degradation of these lipids, including the integral membrane enzyme fatty acid amide hydrolase; and (3) two G‐protein coupled receptors, CB1 and CB2, which are primarily localized to the nervous system and immune system, respectively. Here, we review recent genetic, behavioral, and pharmacological studies that have tested the function of the endocannabinoid system in pain sensation. Collectively, these investigations support a role for endocannabinoids in modulating behavioral responses to acute, inflammatory, and neuropathic pain stimuli. © 2004 Wiley Periodicals, Inc. J Neurobiol 61: 149–160, 2004
Antinociceptive and nociceptive actions of opioids
Authors: Ossipov Michael H. , Lai Josephine , King Tamara , Vanderah Todd W. , Malan T. Philip , Hruby Victor J. , Porreca Frank 
Published: September 2004

AbstractAlthough the opioids are the principal treatment options for moderate to severe pain, their use is also associated with the development of tolerance, defined as the progressive need for higher doses to achieve a constant analgesic effect. The mechanisms which underlie this phenomenon remain unclear. Recent studies revealed that cholecystokinin (CCK) is upregulated in the rostral ventromedial medulla (RVM) during persistent opioid exposure. CCK is both antiopioid and pronociceptive, and activates descending pain facilitation mechanisms from the RVM enhancing nociceptive transmission at the spinal cord and promoting hyperalgesia. The neuroplastic changes elicited by opioid exposure reflect adaptive changes to promote increased pain transmission and consequent diminished antinociception (i.e., tolerance). © 2004 Wiley Periodicals, Inc. J Neurobiol 61: 126–148, 2004
Voltage‐gated sodium channels and pain pathways
Authors: Wood John N. , Boorman James P. , Okuse Kenji , Baker Mark D. 
Published: September 2004

AbstractAcute, inflammatory, and neuropathic pain can all be attenuated or abolished by local treatment with sodium channel blockers such as lidocaine. The peripheral input that drives pain perception thus depends on the presence of functional voltage‐gated sodium channels. Remarkably, two voltage‐gated sodium channel genes (Nav1.8 and Nav1.9) are expressed selectively in damage‐sensing peripheral neurons, while a third channel (Nav1.7) is found predominantly in sensory and sympathetic neurons. An embryonic channel (Nav1.3) is also upregulated in damaged peripheral nerves and associated with increased electrical excitability in neuropathic pain states. A combination of antisense and knock‐out studies support a specialized role for these sodium channels in pain pathways, and pharmacological studies with conotoxins suggest that isotype‐specific antagonists should be feasible. Taken together, these data suggest that isotype‐specific sodium channel blockers could be useful analgesics. © 2004 Wiley Periodicals, Inc. J Neurobiol 61: 55–71, 2004
Volumetric locking in natural neighbour Galerkin methods
Authors: González D. , Cueto E. , Doblaré M. 
Published: September 2004

AbstractThe behaviour of natural neighbour Galerkin mixed approximation is described at the incompressible limit. Traditional natural elements based on the Sibson mixed interpolation do not verify the LBB (or inf–sup) condition. Here, a study of the possible benefits of enriching the interpolation is considered using the partition of unity paradigm. Different enrichments were tested leading to different reproducing properties. Results concerning the numerical verification of the inf–sup tests are addressed. Also the convenience of using different approximations developed in this work is analysed. Enrichment with the polynomial field {1, xy} seems to verify the LBB condition. Its behaviour has proven to be very similar to the MINI Finite Element, widely used in the literature. Examples proving these results are provided. Copyright © 2004 John Wiley & Sons, Ltd.