bluuebunny/crossref_metadata_2025 huggingface dataset:
Ink‐Jet Printing, Self‐Assembled Polyelectrolytes, and Electroless Plating: Low Cost Fabrication of Circuits on a Flexible Substrate at Room Temperature
Authors: Cheng Kevin , Yang Ming‐Huan , Chiu Wanda W. W. , Huang Chieh‐Yi , Chang Jane , Ying Tai‐Fa , Yang Yang
Published: February 2005

Summary: The driving forces behind the development of flexible electronics are their flexibility, lightweightedness, and potential for low‐cost manufacturing. However, because of physical limitations, traditional thermal processes cause deformations in the flexible substrate. As a result, the adhesion quality of the printed wires is deteriorated. This article reviews recent developments in printing circuits on a flexible substrate by combining self‐assembled polyelectrolytes, ink‐jet printing of a catalyst, and electroless plating of metals. The limitations and potential applications of this technology are also discussed. Experiments implementing this technology demonstrated significant results. By a vibration‐induced assistance during an ink‐jet printing catalyst process, line width and blurring can be controlled to within ±3% variation. Following the IPC 6013 standard for flexible electronics, the results after thermal cycling (288 °C, 6 times) and a hot oil test (260 °C, 3 times) indicated that the metallic circuit had retained excellent adhesion properties and electric characteristics. We also report the first successful demonstration of a metal film in a via‐hole inner wall on a flexible substrate. This novel fabrication method is ideal for the realization of large area, flexible electronics and future multilayer flexible substrate application, such as flexible display, chip on flexible substrate, etc., particularly where traditional lithographic processes can not be applied.

Flexible high‐density circuit on an FR‐4 substrate (left) and picture of via hole with copper inner wall (right).

magnified image

Flexible high‐density circuit on an FR‐4 substrate (left) and picture of via hole with copper inner wall (right).
Ink‐Jet Printing of Luminescent Ruthenium‐ and Iridium‐Containing Polymers for Applications in Light‐Emitting Devices
Authors: Tekin Emine , Holder Elisabeth , Marin Veronica , de Gans Berend‐Jan , Schubert Ulrich S.
Published: February 2005

Summary: Defined films of luminescent ruthenium(II) polypyridyl‐poly(methyl methacrylate) (PMMA) and iridium(III) polypyridyl‐polystyrene (PS) copolymers could be prepared by ink‐jet printing. The copolymers were deposited on photoresist‐patterned glass substrates. Films as thin as 120 nm could be printed with a roughness of 1 to 2%. In addition, the film thickness could be varied in a controlled way through the number of droplets deposited per unit area. The topography of the ink‐jet printed films was analyzed utilizing an optical profilometer. The absorbance and emission spectra were measured using fast parallel UV‐vis and fluorescence plate reader.

Photo of the solutions of luminescent ruthenium (left) and iridium (right) containing polymers in a glass microtiter plate (top). The subsequently prepared films using ink‐jet dispensing techniques are shown below.

magnified image

Photo of the solutions of luminescent ruthenium (left) and iridium (right) containing polymers in a glass microtiter plate (top). The subsequently prepared films using ink‐jet dispensing techniques are shown below.
Nitroxide‐Mediated Polymerization of Styrene in a Continuous Tubular Reactor
Authors: Enright Thomas E. , Cunningham Michael F. , Keoshkerian Barkev
Published: February 2005

Summary: Nitroxide‐mediated polymerization of styrene in a continuous tubular reactor has been demonstrated for the first time. The polymerization kinetics in the tubular reactor are similar to those in a batch reactor. The number average molecular weight increases linearly with conversion, and chain extension experiments were successful, indicating that the living nature of the polymerization is maintained in the tubular reactor.

Evolution of molecular weight as measured by GPC for chain‐extended latex in continuous tubular reactor.

magnified image

Evolution of molecular weight as measured by GPC for chain‐extended latex in continuous tubular reactor.
Hospital usage of antibacterial agents in relation to size and type of hospital and geographical situation
Authors: Blix Hege Salvesen , Hartug Stig
Published: February 2005

Purpose

The objective of this study was to evaluate the level of use and therapy profile of antibacterial agents in hospitals. Further to explore whether type, size or geographical situation influenced antibacterial agents used.

Methods

Antibacterial use during 1998–1999, in 13 hospitals, including emergency, referral and university hospitals from all health regions in Norway, were collected retrospectively. Drugs were classified according to the ATC classification and the ATC/DDD index 2001 and standardised bed‐days were used.

Results

Total annual use varied significantly between hospitals (p < 0.01), mean 47.5 DDD/100 bed‐days. Neither size, type of hospital, nor were geographical situations predictors for total hospital use of antibacterial agents. Therapy patterns were approximately similar all over the country. Beta‐lactamase sensitive penicillins were most frequently used in all hospitals. University hospitals and large hospitals used more 3rd generation cephalosporins. Small hospitals used more penicillins with extended specter.

Conclusions

Size, type and geographical situation do not influence the level of antibacterial use in Norwegian hospitals. However, therapeutic choice of antibacterial agents differs and seems to be influenced by hospital size and hospital type. Copyright © 2005 John Wiley & Sons, Ltd.
Synthesis and characterization of random and block copolymers with pendant rhenium diimine complexes by controlled radical polymerization
Authors: Tse Chui Wan , Lam Lillian Sze Man , Man Ka Yan Kitty , Wong Wing Tak , Chan Wai Kin
Published: February 2005

We report the polymerization of rhenium‐containing methacrylates by atom transfer radical polymerization. The structure of the monomer was confirmed by X‐ray crystallography, which showed the bulkiness of the metal‐complex moiety. The rhenium complexes were polymerized in the presence of copper(I) bromide, 1,1,4,7,7‐pentamethyldiethylenetriamine, and methyl 2‐bromopropionate. They were copolymerized with methyl methacrylate in different monomer ratios. An ABA triblock copolymer was also synthesized with poly(methyl methacrylate) as the macroinitiator. When 2,2′‐bipyridine was used as the ligand for the copper catalyst in the polymerizations, it underwent a ligand exchange process with the iminopyridine ligand in the monomer. The neutral rhenium complex in the homopolymers and copolymers could be converted into ionic forms by the replacement of the chloride with an imidazole ligand, and the solubility of the resulting ionic polymers was greatly enhanced. The photosensitizing properties of the doped and undoped polymer films were investigated by the measurement of the photocurrent response under an externally applied electric field. The photoconductivities of the polymers were approximately 10−12–10−13 Ω−1 cm−1. The experimental quantum efficiencies were simulated with Onsager's theory, and they showed that the initial quantum yield and thermalization distance were 10−3 and 1.7 nm, respectively. Transmission electron microscopy showed that the rhenium complexes aggregated to form domains with dimensions of approximately 20–30 nm. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1292–1308, 2005
Deposition of Well‐Defined Fluoropolymer Nanospheres on PET Substrate by Plasma Polymerization of Heptadecafluorodecyl Acrylate and Their Potential Application as a Protective Layer
Authors: Feng Jia Chun , Huang Wei , Fu Guo Dong , Kang En‐Tang , Neoh Koon‐Gee
Published: February 2005

Summary: Fluoropolymer films consisting of well‐defined nanospheres were deposited via pulsed plasma polymerization of 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10‐heptadecafluorodecyl acrylate (HDFA) on flexible poly(ethylene terephthalate) (PET) substrates. The morphology of the nanostructured fluoropolymer films was studied by field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). The mean diameter (Dm) and standard deviation in diameter (SD) of the fluoropolymer nanospheres, as derived from the surface FESEM images of the films, were about 17 nm and 2 nm, respectively. The formation of highly uniform and well‐structured nanospheres was achieved through the removal of the reactive species and the monomer in‐between successive plasma bursts. The interspersed cleaning and monomer‐free purging process eliminated the post‐plasma polymerization effect (polymerization carried out by the persisting radicals and ions on the nanoparticle surface during the plasma‐off period) and allowed a better control of the particle growth. The chemical composition of the nanostuctured fluoropolymer films was studied by X‐ray photoelectron spectroscopy (XPS). The performance of the nanostructured fluoropolymer film as a barrier against water absorption and its effect on the transparency of the PET substrate in the visible region, upon prolonged exposure to water at an elevated temperature, were also evaluated.

AFM image of the surface of the PET substrate covered with a fluoropolymer film of deposited nanospheres.

image

AFM image of the surface of the PET substrate covered with a fluoropolymer film of deposited nanospheres.
Initiation and Microbial‐Disinfection Characteristics of Wide‐Gap Atmospheric‐Pressure Glow Discharge Using Soft X‐Ray Ionization
Authors: Ohkawa Hiroshi , Akitsu Tetsuya , Tsuji Masao , Kimura Hideo , Fukushima Kinpei
Published: February 2005

Summary: A wide‐gap (up to 30 mm) radio frequency (RF) glow discharge was realized at atmospheric pressure, using soft X‐ray photo‐emission, pre‐ionization. The RF glow plasma was excited with an automated matching system, at industrial frequencies (13.56 and 27.12 MHz), in helium or helium‐diluted oxygen. Antibacterial effects were examined using spore‐forming bacteria: Bacillus atrophaeus, Bacillus subtilis, Geobacillus stearothermophilus, Bacillus pumilis, and selected species of bacteria, a mold, and a yeast‐like fungus: Pseudomonas aeroginosa, Salmonella enteritidis, Enterobactor aerogenes, Lactobacillus plantarum, Staphylococcus aureus, Candida albicans, and Aspergillus niger.

Experimental comparison of disinfection time using dry‐heat treatment and plasma treatment at 90 °C.

image

Experimental comparison of disinfection time using dry‐heat treatment and plasma treatment at 90 °C.
Access of Plasma Polymerization and Plasma Induced Vapor Phase Grafting Processes to High Aspect Ratio Trenches in Polymeric Microstructures Analyzed by XPS
Authors: Besch Wilfried , Schröder Karsten , Ohl Andreas
Published: February 2005

Summary: The results of scanning XPS investigations are reported. These were performed to investigate the access of different plasma processes to high aspect ratio trenches. Polystyrene test specimens containing special trench structures were treated by plasma polymerization or by plasma induced vapor phase grafting of allylamine. Highly resolved C1s peak spectra and the ratio of the nitrogen peak areas to the basic CHx peak were analyzed. Pulsed microwave and pulsed RF plasma polymerization of allylamine resulted in different inhomogeneous nitrogen content distributions on the side walls of the trenches. A depletion of the nitrogen content was observed for both processes. For the microwave process, the nitrogen content was also influenced by the aspect ratio, which varied from 2 to 10 for a trench depth of 3.5 mm. At the expense of chemical uniformity, a high N/C value was obtained by the pulsed MW plasma process. Vapor phase grafting of allylamine created inner surface functionalization which was rather uniform in terms of chemical composition and thickness.

Scheme showing the analyzed part of the test specimen. It presents the side walls of the trench for measurement. The position of highly resolved C1s peak measurements is indicated as an open circle.

image

Scheme showing the analyzed part of the test specimen. It presents the side walls of the trench for measurement. The position of highly resolved C1s peak measurements is indicated as an open circle.
Photoacoustic and photoluminescence studies of H+ ion‐implanted n‐GaAs
Authors: Srinivasan R. , Sanjeeviraja C. , Ramachandran K.
Published: February 2005

The surface of silicon‐doped GaAs (100) grown by the vertical Bridgman method has been implanted with H+ ions at 30 keV for various doses from 1014 to 1017 cm–2 and studied using photoacoustic and photoluminescence spectroscopy to understand the effects of hydrogen ion implantation on GaAs:Si. The results are compared with Raman measurements. All the measurements confirm the sign change of charge carriers at a dose of 1015 cm–2. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ellipsometric spectroscopy on polycrystalline CuIn1–xGaxSe2: Identification of optical transitions
Authors: El Haj Moussa G. W. , Ajaka M. , El Tahchi M. , Eid E. , Llinares C.
Published: February 2005

Bulk materials have been synthesized by the Bridgman technique using the elements Cu, Ga, In, Se. Bulk samples have been characterized by EDS (Energy Dispersive Spectrometer), hot point, X‐ray diffraction, photoluminescence and spectroscopic ellipsometry (SE). The samples used were well crystallized and lended strong support to the achievement of a good stoechiometry. Energy levels above the gap in the band scheme were determined by measuring the dielectric function at ambient temperature for energies lying between 1.5 and 5.5 eV. Many transitions were observed above the gap for different samples of CuIn1–xGaxSe2 (0 ≤ x ≤ 1) alloy. Spectroscopic ellipsometry gave evidence for the interpretation of the choice of gap values which were compatible with that obtained from solar spectrum [1]. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Epitaxial Lift‐Off for large area thin film III/V devices
Authors: Schermer J. J. , Mulder P. , Bauhuis G. J. , Voncken M. M. A. J. , van Deelen J. , Haverkamp E. , Larsen P. K.
Published: February 2005

The present work describes the study and improvement of the Epitaxial Lift‐Off (ELO) technique, which is used to separate III/V device structures from their GaAs substrates. As a result the ELO method, initially able to separate millimetre sized GaAs layers with a lateral etch rate of about 0.3 mm/h, has been developed to a process capable to free entire 2″ epitaxial structures from their substrates with etch rates up to 30 mm/h. It is shown that with the right deposition and ELO strategy, the thin‐film III/V structures can be adequately processed on both sides. In this way semi‐transparent, bifacial solar cells on glass were produced with a total area efficiency in excess of 20% upon front side illumination and more than 15% upon back side illumination. The cell characteristics indicate that, once the thin film processing has been optimized, ELO cells require a significantly thinner base layer than regular III/V cells on a GaAs substrate and at the same time have the potential to reach a higher efficiency. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical method based on Magnus expansion and a new shooting method for eigenvalues of Schrödinger equation
Authors: Liu Xue‐Shen , Ding Pei‐Zhu
Published: February 2005

The one‐dimensional time‐independent Schrödinger equation is transformed into the Hamiltonian canonical equation by means of the Legendre transformation, the numerical method based on the Magnus expansion and the Taylor expansion of the matrix exponential are applied to the numerical solutions, and a new shooting method for eigenvalues is presented. The method is applied to the calculations of the one‐dimensional harmonic oscillator, a doubly anharmonic oscillator, and a Morse potential. The numerical results are in good agreement with the exact results. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
HGLM versus conditional estimators for the analysis of clustered binary data
Authors: Kang Weechang , Lee Moo‐Song , Lee Youngjo
Published: February 2005

Clustered binary data arise frequently in medical research such as cross‐over clinical trials and twin studies. For the analysis of such data either a random‐effects model or a conditional likelihood approach can be used. In this paper, we compare numerically the random‐effects model estimator and the conditional likelihood estimator and discuss their relative merits for the analysis of binary data. Copyright © 2005 John Wiley & Sons, Ltd.
Mixed modelling to characterize genotype–phenotype associations
Authors: Foulkes A. S. , Reilly M. , Zhou L. , Wolfe M. , Rader D. J.
Published: February 2005

We propose using mixed effects models to characterize the association between multiple gene polymorphisms, environmental factors and measures of disease progression. Characterizing high‐order gene–gene and gene–environment interactions presents an analytic challenge due to the large number of candidate genes and the complex, undescribed interactions among them. Several approaches have been proposed recently to reduce the number of candidate genes and post hoc approaches to identify gene–gene interactions are described. However, these approaches may be inadequate for identifying high‐order interactions in the absence of main effects and generally do not permit us to control for potential confounders. We describe how mixed effects models and related testing procedures overcome these limitations and apply this approach to data from a cohort of subjects at risk for cardiovascular disease. Four (4) genetic polymorphisms in three genes of the same gene family are considered. The proposed modelling approach allows us first to test whether there is a significant genetic contribution to the variability observed in our disease outcome. This contribution may be through main effects of multi‐locus genotypes or through an interaction between genotype and environmental factors. This approach also enables us to identify specific multi‐locus gentoypes that interact with environmental factors in predicting the outcome. Mixed effects models provide a flexible statistical framework for controlling for potential confounders and identifying interactions among multiple genes and environmental factors that explain the variability in measures of disease progression. Copyright © 2005 John Wiley & Sons, Ltd.
Existence of lipid vesicles containing platelet-activating factor in endothelial cell lysate
Authors: Kojima S. , Nara K. , Inada Y. , Hirose S. , Saito Y.
Published: February 2005

Platelet aggregation activity due to platelet-activating factor (PAF) was detected at high molecular weight (HMW) and low molecular weight fractions after gel-filtration chromatography of cell lysate of endothelial cells. [3H]PAF added to the cell lysate was similarly distributed after chromatography. The radioactivity associated with HMW fraction was not reduced by digesting the lysate with trypsin, suggesting that PAF was not making complexes with proteins but was included in lipid vesicles in cell lysate. Further evidence showed that an unknown specific factor(s) was needed to form these PAF-containing lipid vesicles. Radioactivity was not found in HMW fraction when [3H]PAF was mixed with cell lysate of vascular smooth muscle cells. When monomeric PAF was added to endothelial cell lysate, the specific activity of aggregation decreased to the level exerted by endogenous PAF-containing lipid vesicles due to incorporation into lipid vesicles. PAF in the form of lipid vesicles was more stable in plasma than monomeric form.
Insulin antagonizes the phagocytosis stimulating action of histamine in Tetrahymena
Authors: Csaba G. , Darvas Zsuzsa
Published: February 2005

Histamine increased specifically the phagocytic activity of the unicellular Tetrahymena, whereas insulin had no influence on it. Insulin antagonized the phagocytosis stimulating action of histamine after simultaneous exposure and after preexposure two days earlier as well, although in the latter case to a lesser degree. Double exposure to a combination of histamine + insulin didn't influence the phagocytic activity at all, demonstrating the histamine antagonizing effect of insulin in this model.
Transferrin binding of bone marrow cells and metabolic activity of erythrocytes after 5 Gy irradiation
Authors: Sancho Pilar , Cuenllas Elvira , Gaitan Soledad , Tejero Concepción
Published: February 2005

The effect of total body irradiation (5 Gy) on functional mouse erythroid lineage has been studied. The transferrin binding capacity by bone marrow cells and the activity of glycolytic regulatory enzymes and intracellular levels of 2,3 bisphosphoglycerate in peripheral blood erythrocytes have been determined. Results obtained along one year post-irradiation period suggest a complete recovery in the erythroid cell lineage with respect to the biological endpoints investigated.
Intestinal absorption of biotin and biocytin in the rat
Authors: Dakshinamurti K. , Chauhan J. , Ebrahim H.
Published: February 2005

The uptake of biotin and biocytin was investigated in rat intestine using the everted sac technique. It has been shown that at biotin and biocytin concentrations !ess than 40 and 50 nM respectively, absorption proceeds by a saturable process, whereas at higher concentrations uptake by passive diffusion predominates. Fractionation of solublized brush border preparations indicates that biotinidase is the only protein which binds biotin in this preparation.
Biochemical topology: From vectorial metabolism to morphogenesis
Authors: Harold Franklin M.
Published: February 2005

In living cells, many biochemical processes are spatially organized: they have a location, and often a direction, in cellular space. In the hands of Peter Mitchell and Jennifer Moyle, the chemiosmotic formulation of this principle proved to be the key to understanding biological energy transduction and related aspects of cellular physiology. For H. E. Huxley and A. F. Huxley, it provided the basis for unravelling the mechanism of muscle contraction; and vectorial biochemistry continues to reverberate through research on cytoplasmic transport, motility and organization. The spatial deployment of biochemical processes serves here as a point of departure for an inquiry into morphogenesis and self-organization during the apical growth of fungal hyphae.
The osmochemistry of electron-transfer complexes
Authors: Rich P. R.
Published: February 2005

Detailed molecular mechanisms of electron transfer-driven translocation of ions and of the generation of electric fields across biological membranes are beginning to emerge. The ideas inherent in the early formulations of the chemiosmotic hypothesis have provided the framework for this understanding and have also been seminal in promoting many of the experimental approaches which have been successfully used. This article is an attempt to review present understanding of the structures and mechanisms of several osmoenzymes of central importance and to identify and define the underlying features which might be of general relevance to the study of chemiosmotic devices.
Narcissus mosaic virus: a potexvirus with an encapsidated subgenomic messenger RNA for coat protein
Authors: Short Margaret N. , Davies Jeffrey W.
Published: February 2005

Narcissus-mosaic-virus RNA is translated into a coat-protein-sized product in wheat-germ cell-free extracts. This protein was shown to be very similar to authentic coat protein by partial proteolysis in SDS/polyacrylamide-gel electrophoresis, and by serology. Fractionation of the RNA revealed a small RNA molecule of approx. 840 nucleotides, which alone coded for the coat protein. This subgenomic RNA was found to be encapsidated in a short virus particle.
Increased thermal stability of solubilized chromatin after poly(ADP-ribose) synthesis
Authors: States J. Christopher , Janakidevi K.
Published: February 2005

A hyperthermic shift in the hyperchromicity curve of thermally denatured swine aortic-smooth-muscle-cell chromatin solubilized by digestion of nuclei with micrococcal nuclease was observed after the chromatin was incubated under conditions to allow poly(ADP-ribose) synthesis by the endogenous poly(ADP-ribose) polymerase. When the order of solubilization and poly(ADP-ribosyl)ation was reversed, a smaller proportion of the solubilized chromatin exhibited greater thermal stability. Nuclease digestion of nuclei preincubated for poly(ADP-ribose) synthesis revealed no difference in kinetics of digestion or fragment size distribution compared to that of control nuclei. Poly(ADP-ribose) synthesis in these nuclei was proportionately greater in the chromatin fraction most resistant to solubilization by micrococcal nuclease treatment.
Phosphorus-31 NMR studies of smooth muscle from guinea-pig taenia coli
Authors: Vogel Hans J. , Lilja Hans , Hellstrand per
Published: February 2005

Phosphorus-31 NMR spectra of superfused isometrically mounted guinea-pig taenia coli were obtained using a horizontal probe at 103.2 MHz. The spectra showed resonances for ATP, phosphocreatine (PCr), and a sugar phosphate resonance. The PCr/ATP ratio was between 1.5 and 2.0 consistent with chemical analysis of tissue extracts. The level of PCr, but not of ATP, decreases reversibly during contraction or inhibition of respiration. These conditions did not cause substantial changes in the intracellular pH, which was 7.0 ± 0.1.
Presence of a dinucleotide fold in cholera toxin: Possible approach to chemoprophylaxis?
Authors: Dorai D. Thambi
Published: February 2005

The ADP-ribosyltransferase activity of the A1. subunit of cholera toxin is specifically inhibited by the dye cibacron blue 3GA. The presence of a ‘dinucleotide fold’ in the A1 subunit is thus established for the first time. This specific inhibition observed in vitro is successfully exploited in vivo for the inhibition of the diarrheal response brought out by the pure toxin in the rabbit ileal-loop test.
Detection of barbiturate-induced surface changes in cerebrocortical synaptosomes by phase partitioning in an aqueous two-phase system
Authors: Arregui M. P. , Pérez-Martos A. , López-Pérez M. J.
Published: February 2005

The barbiturates tested in this work (barbital, phenobarbital, thiopental and pentobartial) modify the partition of synaptosomes in a Dextran T500-poly(ethylene glycol) 4000 two-phase system. Under adequate experimental conditions, the drugs increase the partition into the upper phase and this effect appears to be due to an action on the biological material and not on the interface potential of the system. This conclusion can be drawn from the fact that synaptosomes preincubated with low concentrations (0.1 mM) of barbital and pentobarbital maintained an increased partition into the upper phase. The extent of the effect observed appeared to be inversely proportional to the hydrophobicity of the drugs since phenobarbital and barbital showed a higher effect than thiopental and pentobarbital. Dithionite-induced anoxia, rotenone and ouabain also induced a similar increase of partition of synaptosomes into the upper phase, suggesting that the surface changes detected by phase partitioning modification of synaptosomes could be somehow related to the bioenergetic maintenance of the membrane ATPase.
Up-modulation of phorbol dibutyrate receptors by carbachol and arachidonic acid in rat prostatic epithelial cells
Authors: García-Paramio M. P. , Carmena M. J. , Prieto J. C.
Published: February 2005

Phorbol dibutyrate (PDBu) binding to rat prostatic epithelial cells has been measured as an indirect determination of protein kinase C in this cell system. Analysis of [3H]PDBu binding using competitive displacement demonstrated a single class of PDBu receptors with a Kd=141 nM and a binding capacity of 4.8 pmol PDBu bound/mg cell protein. Raising cytosolic Ca2+ levels by redistribution of intracellular Ca2+ after cell treatment with carbachol or arachidonic acid (which also affects the bulk biophysical properties of the cell membrane) resulted in up-regulation of the available number of PDBu receptors. These results appear to be a consequence of PKC translocation from the cytosolic compartment to the plasma membrane after a cytosolic Ca2+ increase, confirming previous results in other cell systems.
Increased insulin receptor binding in erythrocytes from growth hormone-deficient children
Authors: Dávila N. , Barceló B. , Carranza M. C. , Calle C.
Published: February 2005

Erythrocytes from growth hormone-deficient children (GHd-children) (n=10) showed a statistically significant increase in insulin binding at low unlabeled insulin concentrations, together with a threefold decrease in apparent receptor affinity, as compared to control children (C) (n=11). Scatchard analysis of the binding data using the two-site model revealed that both the receptor concentration R1 [GHd-children 0.10±0.01 ng/ml and C 0.03±0.002 ng/ml] and the dissociation constant KD1 [GHd-children (0.48±0.05)×10−9M and C (0.19±0.01)×10−9M] for high affinitylow capacity sites were significantly increased in erythrocytes from GHd-children, while neither receptor concentrations (R2) nor the dissociation constant (KD2) for low affinity-high capacity sites proved to be altered. These events were accompanied by a normal sensitivity to insulin as well as glucose tolerance in the GHd-group. The meaning of the increased insulin binding with normal insulin sensitivity in GH-deficiency is discussed.
dATP accumulation and ATP depletion in platelets in adenosine deaminase deficiency: Significance for the immune response?
Authors: Simmonds H. A. , Goday A. , Morris G. S. , Fairbanks L. D. , Levinsky R. J.
Published: February 2005

High levels of dATP and dADP, accompanied by ATP depletion, were found in the platelets of two ADA-deficient children with severe combined immunodeficiency (SCID). In vitro studies demonstrated that even normal platelets had the ability to make dATP from deoxyadenosine (dAR) under physiological conditions. This capability was greatly enhanced by conditions simulating ADA deficiency. These results question whether the platelet has a specific role in the normal immune response.
The determination of flux through phenylalanine hydroxylase and homogentisate oxidase in isolated hepatocytes
Authors: Fisher Michael J. , Pogson Christopher I.
Published: February 2005

The metabolic fate of [4-3H]phenylalanine incubated with isolated hepatocytes has been investigated. Analysis of3H2O production and fluorimetric estimation of tyrosine production has allowed calculation of flux through phenylalanine hydroxylase and homogentisate oxidase. The resulting flux determinations are physiologically relevant and hormonally sensitive.
Increased DNA topoisomerase I activity in aging human cell chromatin
Authors: Hamelin Claude , Cousineau Lise , Dion Michel , Yelle Jocelyn
Published: February 2005

Chromatin-associated DNA topoisomerase I activity was measured in human diploid fibroblasts during in vitro aging. No diilerence was detected as a function of cell age in the nicking and the closing activities of the DNA-unwinding enzyme. The capacity of type-I topoisomerase to relax superhelical DNA molecules was, however, increased in aged cells. An age-related increase in nucleoprotein content was also observed.
A role for polyamines in stimulus-secretion coupling in the pancreatic β-cell
Authors: Bungay P. J. , Potter J. M. , Griffin M.
Published: February 2005

Measurement of the content of polyamines in pancreatic islets indicated that no significant change in their concentration took place during glucose-stimulated insulin release. The finding, together with the absence of any effect of α-difluoromethylornithine on glucosestimulated insulin release suggested that rapid synthesis of polyamines is not involved in stimulus-secretion coupling in the β-cell. The concentration of polyamines found in islets were high enough for them to act as substrates for the Ca2+-dependent islet transglutaminase during insulin release. This was further demonstrated by the ability of islet transglutaminase to incorporate [14C]putrescine into proteins from islet homogenates and by the demonstration of an increase in the covalent incorporation of [14C]putrescine into the proteins of intact islets following their challenge with glucose. Unlike monoamine substrates of transglutaminase, putrescine failed to effectively inhibit insulin release when its intracellular concentration was increased. A role for polyamines in the secretory process through their incorporation into islet proteins is suggested.
The fumarate reductase system as a site of anthelmintic attack in Ascaris suum
Authors: Barrowman Margaret M. , Marriner Susan E. , Bogan James A.
Published: February 2005

Various benzimidazole compounds have been shown to be highly eIIective as inhibitors (up to 50% reduction of activity) in vitro of the helminth-specilic enzyme, fumarate reductase, of Ascaris suum. Anthelmintically active and inactive benzimidazoles were similarly effective as inhibitors of enzyme activity. Albendazole-induced inhibition of Iumarate reductase was not observed when the enzyme was preincubated with NADH.
Differential solubility of subcomponents of rat glomerular basement membrane
Authors: Taylor Sarah A. , Price Robert G.
Published: February 2005

Marked differences were found in the electrophoretic profiles and amino-acid compositions of components prepared from rat glomerular basement membrane (GBM) by a number of different solubilization procedures. Treatment with reducing agent resulted in a simplified electrophoretic pattern which was characterized by the presence of a major collagenous component with a mol. wt, of 150 000. In contrast, detergent solubilized mainly lower-mol.-wt, material which had a more polar amino-acid composition. When both reagents were used together the majority of the basement-membrane material was so Jubilized within 2 h and components with mol. wts, of 170 000 and 135 000 were predominant in the pro-α region of the gel. Treatment for a further 16 h was required to solubilize higher-mol.-wt, material and to achieve maximum solubility of components in the pro-α region with mol. wts, of 185 000 and 150 000. These methods provide a means of separating subcomponents of rat GBM while avoiding the problems of degradation inherent in enzymatic procedures.
Unimpaired thermogenic response to noradrenaline in genetic (ob/ob) and hypothalamic (MSG) obese mice
Authors: Duloo A. G. , Miller D. S.
Published: February 2005

The thermogenic response to noradrenaline administration was investigated at 25° in two models of obese mice (genetic ob/ob obesity of the ‘QEC’ strain and monosodium-glutamate-induced obesity) and in their respective lean littermates. Subcutaneous injections of a low dose of noradrenaline (I00 μg/kg body wt.) eJevated metabolic rate by about 3096 in both obese models but not in their respective lean counterparts. In contrast, the increase in metabolic rate after injections of a high dose of noradrenaline (600 μg/kg body wt.) was of a similar magnitude in both lean and obese animals: metabolic rate was increased by 70–80%. These results indicate that the overall whole body thermogenic capacity is unimpaired at room temperature in this ‘QEC’ strain of ob/ob mice and in the hypothalamic damaged obese mice. Obesity in these models is therefore not associated with a reduced ability to respond to noradrenaline but could rather be due to a failure to release noradrenaline.
Brown fat activity in fasted and refed rats
Authors: Rothwell Nancy J. , Saville M. Elizabeth , Stock Michael J.
Published: February 2005

Four days of fasting in the rat reduced brown-adipose-tissue (BAT) mass, mitochondrial protein, and tissue protein content. Specific binding of guanosine diposphate (GDP) to BAT mitochondria was depressed by 55% in 4d-fasted rats. Rats fasted for 3 d, and then refed a single carbohydrate meal (40 kJ), showed a significant increase in specific GDP-binding (27% above fasted) 24 h later, and a large increase in total binding. Specific activities of cytochrome oxidase and α-glycerophosphate dehydrogenase in BAT mitochondria were not significantly affected by fasting or refeeding. These results suggest that BAT may be partly responsible for the fall in metabolic rate associated with fasting and the delayed increase after carbo-hydrate refeeding. These effects may be due to changes in the mitochondrial proton-conductance pathway in brown fat.
Partial characterization of human complement factor H by protein and cDNA sequencing: Homology with other complement and non-complement proteins
Authors: Ripoche J. , Day A. J. , Willis A. C. , Belt K. T. , Campbell R. D. , Sim R. B.
Published: February 2005

Factor H, a control protein of the human complement system, is closely related in functional activity to two other complement control proteins, C4b-binding protein (C4bp) and complement receptor type 1 (CR1). C4bp is known to have an unusual primary structure consisting of eight homologous units each about 60 amino acids long. Such units also occur in the N-terminal regions of the complement proteins C2 and factor B, and in the non-complement serum glycoprotein β2I. Amino acid sequencing, and sequencing of a factor H cDNA clone, show that factor H also contains internal repeating units, and is homologous to the proteins listed above.
A new “marker” protein for astrocytes
Authors: Singh Rajkumari , Singh Bhagirath , Malhotra S. K.
Published: February 2005

A monoclonal antibody (Mab J1-31) has been produced by using human brain homogenate as immunogen in mouse. Double-label immunofluorescence microscopy on cryostat sections of human, rabbit and rat brain, reveals staining of cells that are also stained with antiserum to glial fibrillary acidic protein (GFAP, a commonly used marker protein for astrocytes). However, there is no decrease in staining due to Mab J1-31 in sections incubated in antiserum to GFAP prior to incubation with the J1-31 ascites fluid. Immunoprecipitation of aqueous and detergent extracts of brain homogenate gives a single band at 30K by SDS PAGE followed by autoradiography. Immunoelectron microscopy shows that the J1-31 antigen is associated with the cytoskeleton. Thus, the Mab J1-31 recognizes a new protein present in GFAP positive cells (astrocytes) in the brain.
Immunological detection of cDNA clones encoding the uncoupling protein of brown adipose tissue: Evidence for an antigenic determinant within the C-terminal eleven amino acids
Authors: Ridley Robert G. , Patel Hasmukh V. , Parfett Craig L. J. , Olynyk Kimberly A. , Reichling Susanna , Freeman Karl B.
Published: February 2005

Poly(A)+ RNA was isolated from brown adipose tissue of cold acclimated rats and a fraction enriched for uncoupling protein mRNA was used to generate a cDNA library in pBR 322, Immunological screening of 1,500 colonies with an affinity-purified antiserum against the uncoupling protein yielded five positive clones, pUCPratl–5. Clone pUCPrat2 encoded the C-terminal 54 amino acids of rat uncoupling protein and exhibited 90% amino acid homology with the hamster protein. Clones pUCPrat3–5 encoded only the C-terminal 11 amino acids suggesting that an antigenic determinant lies within this sequence.
Compressive and rarefactive ion-acoustic solitons in a two component electron plasma
Authors: McKENZIE J. F. , DOYLE T. B. , HELLBERG M. A. , VERHEEST F.
Published: February 2005

In this paper an analysis is given for the conditions under which compressive and rarefactive ion-acoustic solitons may exist in a plasma containing two electron populations, one hot and the other cool. Compressive solitons exist in the collective Mach number range $1\,{<}\,M\,{<}\,M_{\rm c}$, which, for a given abundance ratio of the cool population, translates into an annular region in the ion-acoustic Mach numbers space. The upper limit $M_{\rm c}$ corresponds to a degenerate sonic point for the protons in which they tend to an infinite compression and are brought to rest at the wave centre. To form a charge neutral point in the rarefactive regime (a prerequisite to the existence of rarefactive solitons) it is necessary that the ‘scale height’ of the hot electrons be sufficiently large that their number density, which is nearly constant, approximately balances that of the protons, before the cool electrons experience their ‘atmospheric lid’. Furthermore, a sufficient condition for the existence of rarefactive solitons is found by requiring a solution to the wave structure equation at the ‘lid’. The case of very hot electrons (highly sub-ion-acoustic) is considered, and various parameter regimes in which compressive and rarefactive solitons exist are evaluated in this super-hot electron approximation, both for the polytropic case, $\gamma \neq 1$, and the isothermal case, $\gamma = 1$. This approximation is formally equivalent to the problem of a bi-ion plasma, including a super-massive negative species.
Negative energy waves
Authors: LASHMORE-DAVIES C. N.
Published: February 2005

A brief history of the concept of negative energy waves in fluid and plasma media is given. The theory of microwave tubes is highlighted, where the small signal power theorem was first derived, which led to the interpretation of these devices in terms of the interaction of positive and negative energy waves. Three examples are described to illustrate the use of negative waves in stability problems. The first is concerned with the Kelvin–Helmholtz instability in neutral fluids. The second comes from a kinetic theory of instability in a collisionless shock wave in a magnetized plasma, and the third is concerned with the effect of a resistive wall and plasma flow on the magnetohydrodynamic stability of a magnetically confined plasma. The paper ends with some general conclusions.
Asymptotic treatment of the three-wave nonlinear parametric interaction
Authors: FUCHS V.
Published: February 2005

A novel integral representation suitable for the study of asymptotic ($L/L_{0}\,{\gg}\,1$, $L$ being the plasma length and $L_{0}$ the basic gain length) stability of the inhomogeneous three-wave interaction is formulated and applied to the special case of uniform gain and ramp wavenumber mismatch. The absolute instability condition is $\kappa L_{0} \,{<}\, \pi /8$ ($\kappa$ being the mismatch gradient), with the wave conversion performed in a zone of width $4/\kappa L_{0}$ located at the boundary of wave incidence.
Relativistic self-compression approaching the Schwinger limit
Authors: SHUKLA PADMA K. , ELIASSON BENGT , MARKLUND MATTIAS
Published: February 2005

The effects of relativistic mass increase is considered in the context of intense laser–plasma interactions. It is found that the result of the relativistic effect is to enhance the self-compression and collapse of the intense laser pulse, making it possible to reach the Schwinger field limit, at which pair creation would need to be considered.
Modulated dust-acoustic wave packets in a plasma with non-isothermal electrons and ions
Authors: KOURAKIS I. , SHUKLA P. K.
Published: February 2005

The Nonlinear self-modulation of dust acoustic waves is studied in the presence of non-thermal (non-Maxwellian) ion and electron populations. By employing a multiple scale technique, a nonlinear Schrödinger-type equation (NLSE) is derived for the wave amplitude. The influence of non-thermality, in addition to obliqueness (between the propagation and modulation directions), on the conditions for modulational instability to occur is discussed. Different types of localized solutions (envelope excitations) which may possibly occur are discussed, and the dependence of their characteristics on physical parameters is traced. The ion deviation from a Maxwellian distribution comes out to be more important than the electron analogous deviation alone. Both yield a de-stabilizing effect on (the amplitude of) DAWs propagating in a dusty plasma with negative dust grains, and thus favour the formation of bright- (rather than dark-) type envelope structures (solitons) in the plasma. A similar tendency towards amplitude de-stabilization is found for the case of the presence of positively charged dust in the plasma.
Noether methods for fluids and plasmas
Authors: BRIZARD A. J.
Published: February 2005

Two applications of the Noether method for fluids and plasmas are presented based on the Euler–Lagrange and Euler–Poincaré variational principles, which depend on whether the dynamical fields are to be varied independently or not, respectively. The relativistic cold laser–plasma equations, describing the interaction between an intense laser field with a cold relativistic electron plasma, provide a useful set of equations amenable to both variational formulations. The derivation of conservation laws by the Noether method proceeds from the Noether equation, whose form depends on the variational formulation used. As expected, the expressions for the energy–momentum conservation laws are identical in both variational formulations. The connection between the two Lagrangian densities is shown to involve the mass conservation and Lin constraints associated with the cold relativistic electron fluid.
Parametric excitation of neutrino pairs by electron plasma waves
Authors: MENDONÇA J. T. , SERBETO A. , BINGHAM R. , SHUKLA P. K.
Published: February 2005

The collective coupling of neutrinos and anti-neutrinos in a dense plasma is considered. Such a coupling is provided by the existence of electron plasma waves. These waves can parametrically excite neutrino–anti-neutrino pairs, and the parametric decay rate is established. This stimulated process for neutrino pair production can eventually become dominant over the single particle decay rates characteristic of the usual Urca process and provide an alternative mechanism for the neutrino cooling of collapsing neutron stars.
AT FEVER PITCH: THE MUSIC OF JÖRG WIDMANN
Authors: Lack Graham
Published: February 2005

Just as a young grand master chooses, with a degree of self-acknowledgement, an opening that creates space for key playing strengths at a later stage, Jörg Widmann seems with every new work to alight on an initial strategy (usually in the form of just a single sound or a complex but discrete sonic entity) which not only occasions further related ideas in the composer's imagination but also reveals feasible compositional paths through the new material. In performance, this simultaneity of creation – in which the primary gesture is clearly a microcosm of the piece itself – may be perceived too in real time by the audience. Any closer analogy with the game of chess breaks down at this point: Widmann's openings remain ambiguous, marked by both a tentative approach and moved by a desire for more telling blows to render a score complete. Music – or the calling to write it, at least – remains nonetheless a considerable opponent. And the sense of the composer finding his bearings at the outset (one might say the onset) of a piece is palpable. A febrile tension is created.
Holliger's Violin Concerto
Authors: Palmer Peter
Published: February 2005

HOLLIGER: Violin Concerto, ‘Hommage à Louis Soutter’. YSAŸE: Sonata op. 27, No. 3, ‘Ballade’ for solo violin. Thomas Zehetmair (vln), SWR Sinfonieorchester c. Heinz Holliger. ECM New Series 476 1941.