bluuebunny/crossref_metadata_2025_split huggingface dataset:
Column chromatographic prefractionation leads to the detection of 543 different gene products in human fetal brain
Authors: Shin Joo‐Ho , Krapfenbauer Kurt , Lubec Gert 
Published: June 2005

AbstractIn a previous publication a large series of proteins were identified in fetal human brain by the use of two‐dimensional electrophoresis (2‐DE) with subsequent matrix‐assisted laser desorption/ionization‐time of flight (MALDI‐TOF) and MALDI‐tandem time‐of‐flight (TOF/TOF) analysis. Further identification of many more different spots by traditional 2‐DE without additional step such as narrow immobilized ph gradient (IPG) strips or prefractionation seems unlikely and we therefore decided to separate extracted brain proteins by ion‐exchange chromatography using a TSK gel DEAE‐5PW column followed by 2‐DE of individual fractions and analysis by MALDI‐TOF/TOF with LIFT technology in fetal brain of the early second trimester. About 1880 protein spots corresponding to 543 different gene products were identified. These proteins included housekeeping, signaling, cytoskeletal, metabolic, antioxidant, and neuron/synaptosomal specific proteins. Among these, 314 gene products (314/543, 57.8%), which have never been detected in traditional 2‐DE of human fetal brain, were observed by this method. This updated map of fetal brain proteins may serve as data base and reference map for fetal brain proteins, and the methodology applied may be used as a valuable analytical tool for the basis of protein expressional studies in health and disease.
Chrispaulia, a new genus of mud star (Asteroidea, Goniopectinidae) from the Cretaceous of England
Authors: Gale Andrew S. 
Published: June 2005

AbstractThe asteroid species Nymphaster radiatus Spencer is redescribed in detail and placed in a new genus, Chrispaulia. Newly collected associated ossicles including ambulacral, adambulacral, marginal, terminal and actinal plates demonstrate that this taxon is a member of the family Goniopectinidae (order Paxillosida, suborder Cribellina), rather than of the Goniasteridae (order Valvatida) as hitherto presumed. This is the first fossil record of the Goniopectinidae, which is a small and rather uncommon family in Recent seas. Living Cribellina are specialized deposit feeders which burrow into muddy substrates in moderately deep marine to abyssal environments. The restriction of C. radiatus to Cretaceous muds and marly chalks, taken in conjunction with morphological evidence, leads to the conclusion that this species had a similar life style. The occurrence of fossil Cribellina is reviewed and the Cretaceous (Campanian) genus Paleoctenodiscus from Mexico is assigned to the Porcellanasteridae. Copyright © 2005 John Wiley & Sons, Ltd.
Rapid and reactive nitric oxide production by astrocytes in mouse neocortical slices
Authors: Buskila Yossi , Farkash Shai , Hershfinkel Michal , Amitai Yael 
Published: June 2005

AbstractNitric oxide (NO), a cellular signaling molecule, is produced in the brain by both neurons and astrocytes. While neurons are capable of rapid release of small amounts of NO serving as neurotransmitter, astrocytic NO production has been demonstrated mainly as a slow reaction to various stress stimuli. Little is known about the role of astrocyte‐produced NO. Using the NO indicator 4,5‐diaminofluorescein‐2 diacetate (DAF‐2DA) and acute slices from mouse brain, we distinguished neurons from astrocytes based on their different fluorescence kinetics and pattern, cellular morphology, electrophysiology, and responses to selective nitric oxide synthase (NOS) inhibitors. Typically, astrocytic fluorescence followed neuronal fluorescence with a delay of 1–2 min and was dependent on the inducible NOS isoform (iNOS) activity. Western blot analysis established the presence of functional iNOS in the neocortex. An assay for cell death revealed that most DAF‐2DA‐positive neurons, but not astrocytes, were damaged. Whole cell recordings from astrocytes confirmed that these cells maintained their membrane potential and passive properties during illumination and afterward. Induction of excitotoxicity by brief application of glutamate triggered an immediate and intense astrocytic response, while high‐frequency electrical stimulation failed to do so. The present study demonstrates, for the first time, rapid and massive iNOS‐dependent NO production by astrocytes in situ, which appears to be triggered by acute neuronal death. These data may bear important implications for our theoretical understanding and practical management of acute brain insults. © 2005 Wiley‐Liss, Inc.
Anti‐disialosyl antibodies mediate selective neuronal or Schwann cell injury at mouse neuromuscular junctions
Authors: Halstead Susan K. , Morrison Ian , O'Hanlon Graham M. , Humphreys Peter D. , Goodfellow John A. , Plomp Jaap J. , Willison Hugh J. 
Published: June 2005

AbstractThe human paralytic neuropathy, Miller Fisher syndrome (MFS) is associated with autoantibodies specific for disialosyl epitopes on gangliosides GQ1b, GT1a, and GD3. Since these gangliosides are enriched in synaptic membranes, anti‐ganglioside antibodies may target neuromuscular junctions (NMJs), thereby contributing to disease symptoms. We have shown previously that at murine NMJs, anti‐disialosyl antibodies induce an α‐latrotoxin‐like effect, electrophysiologically characterized by transient massive increase of spontaneous neurotransmitter release followed by block of evoked release, resulting in paralysis of the muscle preparation. Morphologically, motor nerve terminal damage, as well as perisynaptic Schwann cell (pSC) death is observed. The relative contributions of neuronal and pSC injury to the paralytic effect and subsequent repair are unknown. In this study, we have examined the ability of subsets of anti‐disialosyl antibodies to discriminate between the neuronal and glial elements of the NMJ and thereby induce either neuronal injury or pSC death. Most antibodies reactive with GD3 induced pSC death, whereas antibody reactivity with GT1a correlated with the extent of nerve terminal injury. Motor nerve terminal injury resulted in massive uncontrolled exocytosis with paralysis. However, pSC ablation induced no acute (within 1 h) electrophysiological or morphological changes to the underlying nerve terminal. These data suggest that at mammalian NMJs, acute pSC injury or ablation has no major deleterious influence on synapse function. Our studies provide evidence for highly selective targeting of mammalian NMJ membranes, based on ganglioside composition, that can be exploited for examining axonal–glial interactions both in disease states and in normal NMJ homeostasis. © 2005 Wiley‐Liss, Inc.
Olfactory ensheathing cells and olfactory nerve fibroblasts maintain continuous open channels for regrowth of olfactory nerve fibres
Authors: Li Ying , Field Pauline M. , Raisman Geoffrey 
Published: June 2005

AbstractThe ensheathing cells of the olfactory nerves are arranged end‐to‐end to form a continuous channel enclosing the olfactory axons from their origin in the olfactory mucosa to their termination in the olfactory bulb. On their outer surface, the olfactory ensheathing cell channels have a basal lamina and an outer encirclement of olfactory nerve fibroblasts. We present an anatomical model of the ensheathing arrangements for the entire transit of the olfactory axons from the horizontal basal cells of the mucosa through the nerves to the superficial astrocytes of the bulb. We used intracranial section of the olfactory nerves to induce a rapid retrograde loss of olfactory neurons and degeneration of their axons, followed by replacement of the neurons from stem cells in the mucosa and growth of the newly formed axons along the olfactory nerves. The olfactory ensheathing cells survive and play a vital role in this process. Unlike Schwann cells in damaged peripheral nerve, the olfactory ensheathing cells neither divide nor migrate. They are actively phagocytic for removal of the degenerating axons, and provide continuous stable open channels along which adventitious cells such as erythrocytes and macrophages can travel, and along which the newly formed axons can regenerate. We suggest that the persistence of these open channels is an important element in the effectiveness of the regeneration. These properties, which the olfactory ensheathing cells exert in collaboration with olfactory nerve fibroblasts, may also be involved in the reparative effects of these cells when transplanted into lesions of the spinal cord. © 2005 Wiley‐Liss, Inc.
How the turtle forms its shell: a paracrine hypothesis of carapace formation
Authors: Cebra‐Thomas Judith , Tan Fraser , Sistla Seeta , Estes Eileen , Bender Gunes , Kim Christine , Riccio Paul , Gilbert Scott F. 
Published: June 2005

AbstractWe propose a two‐step model for the evolutionary origin of the turtle shell. We show here that the carapacial ridge (CR) is critical for the entry of the ribs into the dorsal dermis. Moreover, we demonstrate that the maintenance of the CR and its ability to attract the migrating rib precursor cells depend upon fibroblast growth factor (FGF) signaling. Inhibitors of FGF allow the CR to degenerate, with the consequent migration of ribs along the ventral body wall. Beads containing FGF10 can rearrange rib migration in the chick, suggesting that the CR FGF10 plays an important role in attracting the rib rudiments. The co‐ordinated growth of the carapacial plate and the ribs may be a positive feedback loop (similar to that of the limbs) caused by the induction of Fgf8 in the distal tips of the ribs by the FGF10‐secreting mesenchyme of the CR. Once in the dermis, the ribs undergo endochrondral ossification. We provide evidence that the ribs act as signaling centers for the dermal ossification and that this ossification is due to bone morphogenetic proteins secreted by the rib. Thus, once the ribs are within the dermis, the ossification of the dermis is not difficult to achieve. This relatively rapid means of carapace formation would allow for the appearance of turtles in the fossil record without obvious intermediates. J. Exp. Zool. (Mol. Dev. Evol.) 304B, 2005. © 2005 Wiley‐Liss, Inc.
Effect of low‐dose irradiation on shelf life and microbiological safety of sliced carrot
Authors: Kamat AS , Ghadge N , Ramamurthy MS , Alur MD 
Published: June 2005

AbstractMinimally processed non‐irradiated carrots (sliced) exhibited diverse microflora at initial level. During storage, bacterial number increased with the presence of pathogenic bacteria accompanied by a loss of total solids. On the other hand γ‐irradiation at an optimal dose of 2 kGy offered a pathogen‐free, hygienic product with insignificant losses in nutrients such as in sucrose, total carotenes and ascorbic acid content in comparison to controls and 2‐ to 4‐fold increased in shelf‐life at refrigeration temperature. The D10 values of pathogens like Escherichia coli and Yersinia enterocolitica in carrot paste were in a lower range (0.12–0.26 kGy) compared with that of Listeria monocytogenes (0.3–0.5 kGy). The validity of the processing treatment (2 kGy) was challenged by artificially inoculating Listeria monocytogenes in the product. Thus, minimally processed carrots (sliced) are amenable to radiation treatment for extended storage stability and microbial safety. Copyright © 2005 Society of Chemical Industry
Microrobotics and MEMS‐Based Fabrication Techniques for Scaffold‐Based Tissue Engineering
Authors: Zhang Han , Hutmacher Dietmar W. , Chollet Franck , Poo Aun Neow , Burdet Etienne 
Published: June 2005

AbstractSummary: Scaffold based tissue engineering strategies use cells, biomolecules and a scaffold to promote the repair and regeneration of tissues. Although scaffold‐based tissue engineering approaches are being actively developed, most are still experimental, and it is not yet clear what defines an ideal scaffold/cell construct. Solid free form fabrication (SFF) techniques can precisely control matrix architecture (size, shape, interconnectivity, branching, geometry and orientation). The SFF methods enable the fabrication of scaffolds with various designs and material compositions, thus providing a control of mechanical properties, biological effects and degradation kinetics. This paper reviews the application of micro‐robotics and MEMS‐based fabrication techniques for scaffold design and fabrication. It also presents a novel robotic technique to fabricate scaffold/cell constructs for tissue engineering by the assembly of microscopic building blocks.Scaffold design for a single step pop‐up assembly.magnified imageScaffold design for a single step pop‐up assembly.
Luminescent Bis(benzoxazolyl)stilbene as a Molecular Probe for Poly(propylene) Film Deformation
Authors: Pucci Andrea , Bertoldo Monica , Bronco Simona 
Published: June 2005

AbstractSummary: Poly(propylene) (PP) films containing different concentrations of bis(benzoxazolyl)stilbene (BBS) have been prepared by melt processing. We demonstrate that the emission characteristics of PP films depend on BBS concentration and polymer deformation. A well‐defined excimer band is observed with more than 0.2 wt.‐% of BBS, conferring to the film a green luminescence. During drawing (130 °C) the PP reorganisation breaks the BBS excimer‐type arrangement, leading to the prevalence of the blue emission of the single molecules. We have efficiently applied the photophysics of this commercial stilbene derivative to the production of powerful tools acting as an internal probe for PP deformation.Picture of oriented PP/BBS‐0.5 film taken under excitation with a long‐range UV lamp (λ = 366 nm). During drawing, the macromolecular chains reorganisation is able to break the BBS excimer‐type arrangement leading to the prevalence of the blue emission of the single molecules.magnified imagePicture of oriented PP/BBS‐0.5 film taken under excitation with a long‐range UV lamp (λ = 366 nm). During drawing, the macromolecular chains reorganisation is able to break the BBS excimer‐type arrangement leading to the prevalence of the blue emission of the single molecules.
Living Ziegler‐Natta Polymerizations: True or False?
Authors: Busico Vincenzo , Talarico Giovanni , Cipullo Roberta 
Published: June 2005

AbstractBased on the recent literature, the synthesis of novel polyolefin architectures via Ziegler‐Natta chemistry under living conditions appears to be a promising and fast‐growing area. In this paper, the appropriateness of the term “living” as applied to the said context is discussed in mechanistic terms, and the potential and the limitations of the field are outlined with the aid of two paradigmatic case histories (i.e., propene polymerization in the presence of bis(phenoxy‐imine)Ti and bis(phenoxy‐amine)Zr catalysts).
Anionic Polymerization of New Dual‐Functionalized Styrene and α‐Methylstyrene Derivatives Having Styrene or α‐Methylstyrene Moieties
Authors: Hirao Akira , Kitamura Masahiro , Hayashi Mayumi , Loykulnant Surapich , Sugiyama Kenji 
Published: June 2005

AbstractAnionic polymerizations of four new dual‐functionalized styrene and α‐methylstyrene derivatives, 3‐(4‐(4‐isopropenylphenoxy)butyl)styrene (4), 3‐(4‐(2‐isopropenylphenoxy)butyl)‐α‐methylstyrene (5), 4‐(4‐(4‐isopropenylphenoxy)butyl)‐α‐methylstyrene (6), and 4‐(4‐(2‐vinylphenoxy)butyl)styrene (7), were carried out in THF at ‐78 °C with sec‐BuLi as an initiator. Both 4 and 5 underwent anionic polymerization in a living manner to quantitatively afford functionalized polystyrenes and poly(α‐methylstyrene)s having α‐methylstyrene moiety in each monomer unit and precisely controlled chain lengths. On the other hand, insoluble polymers were obtained by the anionic polymerization of 6 and 7 under the same conditions. The positional effect of substituent on anionic polymerization was discussed.
Trialkylsilyl‐Protected Functional Initiators for Stereospecific Anionic Polymerization of Methacrylates
Authors: Kitayama Tatsuki , Kitaura Takehiro 
Published: June 2005

AbstractAnionic polymerizations of methyl methacrylate with trialkylsilyl‐protected lithium benzylamides were conducted in the presence of aluminum compounds such as n‐Bu3Al. When the Me3Si‐protected amide was used, the carbonyl attack took place to some extent to form a methacrylamide derivative with slightly lower initiator efficiency (∼0.9). In the case of i‐Pr3Si‐protected amide, the carbonyl addition was completely suppressed. The obtained polymers had narrow molecular weight distribution and carried benzylamino end‐group, as revealed by NMR analysis, which is readily accessible for further chemical transformations such as acylation with acryloyl chloride and debenzylation with H2/Pd‐C. Difuntional initiators with protected groups were also examined.
Anionic Polymerization Chemistry of Epoxides: Electron‐Transfer Processes
Authors: Quirk Roderic P. , Pickel Deanna L. , Hasegawa Hiroaki 
Published: June 2005

AbstractThe reaction of poly(styryl)lithium (PSLi) with styrene oxide (SO) in benzene solution has been investigated. In addition to the functionalized polymer (83.5 wt %) the product mixture consisted of unfunctionalized polymer (9 wt %) and a dimeric product (5.6 wt %). The structure of the dimeric product was determined to be the head‐to‐head dimer. The regiochemistry of the addition reaction was unselective: 53 mol % addition to the methylene carbon and 47 mol % corresponding to addition to the hindered, methine carbon. Based on the formation of the dimer and the lack of regioselectivity, a pathway involving electron transfer from PSLi to SO was proposed. To further investigate the propensity to react via this electron‐transfer mechanism, the SO functionalization of the adduct of PSLi with 1,1‐diphenylethylene was investigated as well as the functionalization of PSLi with 1,1‐diphenylethylene oxide.
Submicron Sized Hollow Polymer Particles: Preparation and Properties
Authors: Pavlyuchenko Valery N. , Sorochinskaya Olga V. , Primachenko Oleg N. , Ivanchev Sergey S. 
Published: June 2005

AbstractThe considered method for obtaining hollow polymer particles is based on the following pathway: (1) preparation of a carboxylated core latex by emulsion copolymerization of acrylic monomers with methacrylic acid, (2) synthesis of a core‐shell latex comprising a styrene (co)polymer shell, (3) neutralization of the core carboxylic groups with a base followed by the core ionization and hydration to a high degree, shell expansion and formation of water‐filled hollows. A number of approaches to improve the hydrophilic core – hydrophobic shell compatibility and enlarge the hollow volume are considered. The synthesized hollow particles are of a submicron size with the relative hollow volume Vhol : Vpart.= 0.43 – 0.64. Methods for cationic hollow particle latex preparation by anionic latex recharging with a cationic surfactant or acidic melamine resin are discussed. Recharging with a melamine resin is shown to afford hollow particles with an external polymer shell providing a high thermal stability of the particles.
Macroporous Silica Monoliths Derived from Glyceroxysilanes: Controlling Gel Formation and Pore Structure
Authors: Zheng Zhang , Chen Yang , Hodgson Richard J. , Brook Michael A. , Brennan John D. 
Published: June 2005

AbstractDiglycerylsilane (DGS), a member of the family of sugar‐based silanes, is converted into monolithic silica at low temperatures and at mild pH. These materials are suitable for the entrapment of proteins under conditions that generally offer protection against denaturation, particularly when compared to analogous silicas prepared from tetraethoxysilane (TEOS). However, the resulting monoliths did not have sufficient porosity to permit flow and, thus, could not be utilized as monolithic chromatographic supports for frontal affinity chromatography (FAC). It was demonstrated that poly(ethylene oxide) can be used to induce spinodal decomposition of the DGS‐derived sol, prior to gelation, leading to a meso‐ and macroporous silica monolith after cure, as demonstrated by nitrogen sorption analysis. High molecular weight PEO is required for effective phase separation to take place: below 10000 MW, no such phase separation occurs under the conditions employed. The amount and molecular weight of PEO is critical to the timing of gelation. If too much PEO is present, or ionic strength is increased, gelation occurs before it is possible to fill the chromatography column with the sol, while too little results in a lack of macropores. Proteins entrapped in this material are shown to be of comparable stability to those prepared in the absence of PEO, and can be used to chromatographically screen, with MS detection, potential drug candidates by changes in retention resulting from ligand binding.
Simultaneous radiofrequency (RF) heating and magnetic resonance (MR) thermal mapping using an intravascular MR imaging/RF heating system
Authors: Qiu Bensheng , El‐Sharkawy Abdel‐Monem , Paliwal Vaishali , Karmarkar Parag , Gao Fabao , Atalar Ergin , Yang Xiaoming 
Published: June 2005

AbstractPrevious studies have confirmed the possibility of using an intravascular MR imaging guidewire (MRIG) as a heating source to enhance vascular gene transfection/expression. This motivated us to develop a new intravascular system that can perform MR imaging, radiofrequncy (RF) heating, and MR temperature monitoring simultaneously in an MR scanner. To validate this concept, a series of mathematical simulations of RF power loss along a 0.032‐inch MRIG and RF energy spatial distribution were performed to determine the optimum RF heating frequency. Then, an RF generator/amplifier and a filter box were built. The possibility for simultaneous RF heating and MR thermal mapping of the system was confirmed in vitro using a phantom, and the obtained thermal mapping profile was compared with the simulated RF power distribution. Subsequently, the feasibility of simultaneous RF heating and temperature monitoring was successfully validated in vivo in the aorta of living rabbits. This MR imaging/RF heating system offers a potential tool for intravascular MR‐mediated, RF‐enhanced vascular gene therapy. Magn Reson Med 54:226–230, 2005. © 2005 Wiley‐Liss, Inc.
Correction of MR image distortions induced by metallic objects using a 3D cubic B‐spline basis set: Application to stereotactic surgical planning
Authors: Skare S. , Andersson J.L.R. 
Published: June 2005

AbstractMetallic implants in MRI cause spin‐echo (SE) images to be distorted in the slice and frequency‐encoding directions. Chang and Fitzpatrick (IEEE Trans Med Imaging 1992;11:319–329) proposed a distortion correction method (termed the CF method) based on the magnitude images from two SE acquisitions that differ only in the polarity of the frequency‐encoding and slice‐selection gradients. In the present study we solved some problems with the CF method, primarily by modeling the field inhomogeneities as a single 3D displacement field built by 3D cubic B‐splines. The 3D displacement field was applied in the actual distortion direction in the slice/frequency‐encoding plane. To account for patient head motion, a 3D rigid body motion correction was also incorporated in the model. Experiments on a phantom containing an aneurysm clip showed that the knot spacing between the B‐splines is a very important factor in both the final image quality and the processing speed. Depending on the knot spacing and the image volume size, the number of unknowns range from a few thousands to over 100,000, leading to processing times ranging from minutes to days. Optimal knot spacing, a means of increasing the processing speed, and other parameters are investigated and discussed. Magn Reson Med 54:169–181, 2005. © 2005 Wiley‐Liss, Inc.