bluuebunny/crossref_metadata_2025_split huggingface dataset:
A mouse serum two‐dimensional gel map: Application to profiling burn injury and infection
Authors: Duan Xunbao , Yarmush David M. , Berthiaume François , Jayaraman Arul , Yarmush Martin L. 
Published: August 2004

AbstractWith the importance of mouse as a model to study human diseases and the human and rat plasma/serum two‐dimensional (2‐D) maps being extensively annotated, this study was aimed at constructing a detailed mouse serum 2‐D map. Serum proteins from two different inbred strains of mice (BALB/cJ and C57BL/6J) and mice subjected to two different inflammatory stimuli (20% burn injury and lipopolysaccharide (LPS) injection) were separated on overlapping gels covering pH 3–8 and stained with SYPRO Ruby dye. The tryptic peptides from the resolved spots were analyzed by mass spectrometry, leading to the identification of 38 different gene products. With the exception of major urinary proteins found in abundance in male C57BL/6J mice, little strain difference of the mouse serum 2‐D was observed. Many proteins detected in the mouse serum 2‐D map were not reported in human or rat serum 2‐D maps including epidermal growth factor receptor. Three major murine acute‐phase proteins (APPs), haptoglobin, serum amyloid A, and serum amyloid P, were highly induced by both inflammatory stimuli. Image analysis shows that the variations of APPs between these two inflammatory models were not uniform although LPS (100 μg/animal) in general was more effective than 20% burn injury in inducing APPs. Serum amyloid A, much more sensitive to endotoxin than burn injury, may represent a sensitive marker to differentiate these two different inflammatory states.
Formamide as solvent for capillary zone electrophoresis
Authors: Porras Simo P. , Kenndler Ernst 
Published: August 2004

AbstractA comprehensive investigation of a number of aspects when using formamide as background electrolyte solvent in capillary zone electrophoresis was presented. It included (i) the change of the ion mobility with ionic strength, (ii) the influence of the ionic strength on diffusion coefficients, and (iii) on the separation efficiency expressed by the maximum reachable plate numbers (when only longitudinal diffusion contributed to zone broadening), (iv) the effect of the solvent on pKa values (taken from the literature) of neutral and cation acids, (v) the establishment of the a pH scale in formamide by dissolving acids with known pKa values and their salts at defined proportion (thus circumventing the problem of calibrating the pH meter), (vi) the agreement between the experimentally derived and the theoretical dependence of the effective mobility on pH, (vii) the uptake of water of this hygroscopic solvent from the humidity of the environment and its consequence to the ion mobilities, pKa values, and the chemical stability of the solvent (e.g., hydrolysis), and finally (viii) the use of conductivity and indirect UV absorption to enable detection of analytes below the optical cutoff of formamide.
Detection of glutathione reductase after electrophoresis on native or sodium dodecyl sulfate polyacrylamide gels
Authors: Hou Wen‐Chi , Liang Hong‐Jen , Wang Ching‐Chiung , Liu Der‐Zen 
Published: August 2004

AbstractCommercial glutathione reductase (GR) from spinach and yeast (Saccharomyces cerevisiae) were stained on 7.5% native polyacrylamide gel electrophoresis (PAGE) gels or 15% sodium dodecyl sulfate (SDS)‐PAGE gels with or without further purification by a 2',5'‐ADP Sepharose 4B affinity column. For SDS‐PAGE gels, the SDS was removed first by washing twice with 25% isopropanol in 10 mM Tris‐HCl (pH 7.9) for 10 min. The gel was then dipped in a 50 mM Tris‐HCl buffer (pH 7.9) containing 4.0 mM oxidized glutathione (GSSG), 1.5 mM NADPH, and 2 mM 5,5'‐dithiobis(2‐nitrobenzoic acid) (DTNB) for 20 min. The GR activity was negatively stained in the dark by a solution containing 1.2 mM 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) and 1.6 mM phenazine methosulfate (PMS) for 5–10 min. The contrast between the clear zone of GR activity and the purple background was found in both native and SDS‐PAGE gels. This negative staining method can detect GR as little as 0.064 units and 0.0032 units, respectively, for spinach and yeast sources. Under reduced SDS‐PAGE gels, the GR activity band located on 72 kDa for spinach and 51 kDa for yeast. This fast and sensitive method could be used during enzyme purification and for characterization of GR from different sources under different physiological stages or conditions.
Prediction of wheat dough W and P/L inflation test parameters by capillary zone electrophoresis of a protein extract followed by multivariate regression
Authors: Sebastiano Roberto , Simó‐Alfonso Ernesto F. , Citterio Attilio , Ramis‐Ramos Guillermo 
Published: August 2004

AbstractA procedure for the evaluation of the wheat flour hardness, based on capillary electrophoresis of a protein extract in an isoelectric acidic buffer, was developed. The 13 flour samples were extracted twice, and two injections of each extract were made. Separations were performed in a background electrolyte (BGE) containing 40 mM aspartic acid, 6 M urea, and 0.5% hydroxyethylcellulose at 60°C. Using the normalized and corrected areas of 79 peaks and peak groups, a partial least squares regression (PLS1) model was able to predict the flour strength or dough deformation work (W) and the dough tenacity/ extensibility ratio (P/L) (Alveograph parameters) with an average relative standard deviation in the predictions of ± 3% and ±8%, respectively. These values amounted to a ± 6–8% and ± 11% with multiple linear regression (MLR) and PLS1 models constructed by measuring only 12 peaks and peak group areas on the electropherograms.
Charge density profiling of circulating human low‐density lipoprotein particles by capillary zone electrophoresis
Authors: Liu Mine‐Yine , McNeal Catherine J. , Macfarlane Ronald D. 
Published: August 2004

AbstractCapillary zone electrophoresis (CZE) has been utilized to profile the low‐density (LDL) particles in human blood serum in this study. A 5 mM sodium phosphate buffer, pH 7.40, was chosen as the most suitable CE buffer and an extensive ultrafiltration (UF) procedure was applied to purify the LDL sample. Two LDL particle species, LDL with lower mobility and LDL− with higher mobility were observed. The electropherograms were highly reproducible with good precision of effective mobilities, corrected peak areas (CPAs) and CPA ratio of LDL−/LDL. LDL particles shown on the electropherogram were also characterized by several procedures. The applications of Sigma HDL cholesterol reagent and CE on‐line 2‐propanol precipitation indicated that the two particle species shown in the electropherogram belong to LDL. The LDL particles were found to associate with the buoyant LDL fraction and the LDL− particles associate with the dense LDL fraction. This study utilizes CZE for the profiling of LDL isoforms and provides a new analytical method for the resolution of LDL subspecies. It demonstrates a high‐mobility LDL particle which circulates in healthy subjects and diminishes in atherosclerotic patients. Diminution of the high‐mobility LDL subspecies may be linked to minimal formation of arterial plaque in atherosclerotic patients.
Biased fragment distribution in MC simulation of protein folding
Authors: Martineau Eric , L'Heureux Pierre‐Jean , Gunn John R. 
Published: August 2004

AbstractMonte Carlo (MC) methods play an important role in simulations of protein folding. These methods rely on a random sampling of moves on a potential energy surface. To improve the efficiency of the sampling, we propose a new selection of trial moves based on an empirical distribution of three‐residue (triplet) conformations. This selection is compared to random combinations of the preferred conformations of the three amino acids, and it is shown that the new trial moves lead to finding structures closer to the native conformation. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 1895–1903, 2004
Positively curved cubic plane graphs are finite
Authors: Sun Liang , Yu Xingxing 
Published: August 2004

AbstractLet G be an infinite plane graph such that G is locally finite and every face of G is bounded by a cycle. Then G is said to be positively curved if, for every vertex x of G, ${1-{d{(x)}\over 2}+\sum _{x\in F}{1\over |F|}>0}$, where the summation is taken over all facial cycles F of G containing x and |F| denotes the number of vertices in F. Note that if G is positively curved then the maximum degree of G is at most 5. As a discrete analog of a result in Riemannian geometry, Higuchi conjectured that if G is positively curved then G is finite. In this paper, we establish this conjecture for cubic graphs. © 2004 Wiley Periodicals, Inc. J Graph Theory 47: 241–274, 2004
Effect of p75 neurotrophin receptor antagonist on disease progression in transgenic amyotrophic lateral sclerosis mice
Authors: Turner Bradley J. , Murray Simon S. , Piccenna Loretta G. , Lopes Elizabeth C. , Kilpatrick Trevor J. , Cheema Surindar S. 
Published: August 2004

AbstractNeurotrophin level imbalances and altered p75 neurotrophin receptor (p75NTR) expression are implicated in spinal motor neuron degeneration in human and mouse models of amyotrophic lateral sclerosis (ALS). Recently, elevated reactive astrocyte‐derived nerve growth factor (NGF) was linked to p75NTR‐expressing motor neuron death in adult transgenic ALS mice. To test the role of NGF‐dependent p75NTR‐mediated signalling in ALS, we examined the effects of a cyclic decapeptide antagonist of p75NTR ligand binding by using neurotrophin‐stimulated cell death assays and transgenic ALS mice. Murine motor neuron‐like (NSC‐34) cell cultures expressed full‐length and truncated p75NTR, tyrosine receptor kinase B (TrkB), and the novel neurotrophin receptor homolog‐2 (NHR2) but were TrkA deficient. Accordingly, treatment of cells with NGF induced dose‐dependent cell death, which was significantly blocked by the cyclic decapeptide p75NTR antagonist. Application of brain‐derived neurotrophic factor, neurotrophin‐3, or neurotrophin‐4 to cultures increased cell proliferation, and such trophic effects were abolished by pretreatment with the tyrosine kinase inhibitor K‐252a. Systemic administration of a modified cyclic decapeptide p75NTR antagonist conjugated to the TAT4 cell permeabilization sequence to presymptomatic transgenic SOD1G93A mice affected neither disease onset nor disease progression, as determined by hindlimb locomotor, grip strength, and survival analyses. These studies suggest that disrupting NGF‐p75NTR interactions by using this approach is insufficient to alter the disease course in transgenic ALS mice. Thus, alternate ligand‐independent pathways of p75NTR activation or additional NGF receptor targets may contribute to motor neuron degeneration in ALS mice. © 2004 Wiley‐Liss, Inc.
Increased diisopropylfluorophosphate‐induced toxicity in μ‐opioid receptor knockout mice
Authors: Tien Lu‐Tai , Fan Lir‐Wan , Ma Tangeng , Loh Horace H. , Ho Ing‐Kang 
Published: August 2004

AbstractThe potential involvement of μ‐opioid receptors in mediating the changes of toxic signs and muscarinic receptor bindings after acute administration of irreversible antiacetylcholinesterase diisopropylfluorophosphate (DFP) was investigated. DFP‐induced chewing movement and tremors were monitored for a period of 180 min in μ‐opioid receptor knockout and wild‐type mice. The autoradiographic studies of total, M1, and M2 muscarinic receptors were conducted using [3H]quinuclidinyl benzilate, [3H]pirenzepine, and [3H]AF‐DX384 as ligands, respectively. Saline‐treated μ‐opioid receptor knockout and wild‐type mice did not show chewing movement or tremors. Although DFP (1, 2, or 3 mg/kg, subcutaneous injection, s.c.)‐induced chewing movement and tremors were shown in a dose‐dependent manner, there were no significant differences in tremors induced by 1 or 2 mg/kg of DFP between μ‐opioid receptor knockout and wild‐type mice. There were also no significant differences in chewing movement induced by all doses of DFP between μ‐opioid receptor knockout and wild‐type mice. However, DFP (3 mg/kg)‐induced tremors in μ‐opioid receptor knockout mice were significantly increased over those in wild‐type controls. Acetylcholinesterase activity in the striatum of saline‐treated μ‐opioid receptor knockout mice was significantly higher than that of the wild‐type controls. After administration of DFP, acetylcholinesterase activity in the striatum of both μ‐opioid receptor knockout and wild‐type mice was significantly decreased (more than 36%, 58%, and 94% reduced at the doses of 1, 2, and 3 mg/kg, respectively) than that of their respective saline controls. M2 muscarinic receptor binding in saline‐treated μ‐opioid receptor knockout mice was significantly lower than that of the wild‐type controls in the striatum. However, there were no significant differences in total, M1, or M2 muscarinic receptor binding in the cortex, striatum, or hippocampus of μ‐opioid receptor knockout and wild‐type mice after DFP administration. Our data show increased DFP‐induced tremors, compensatory up‐regulation of acetylcholinesterase activity, and compensatory down‐regulation of M2 muscarinic receptors in the striatum of mice lacking μ‐opioid receptor gene. These results suggest that the enhancement of DFP‐induced tremors may be associated with the compensatory up‐regulation of acetylcholinesterase activity and compensatory down‐regulation of M2 muscarinic receptors in the striatum of μ‐opioid receptor knockout mice. © 2004 Wiley‐Liss, Inc.
Astrocytes and oligodendrocytes express different STOP protein isoforms
Authors: Galiano M.R. , Bosc C. , Schweitzer A. , Andrieux A. , Job D. , Hallak M.E. 
Published: August 2004

AbstractMany cell types contain subpopulations of microtubules that resist depolymerizing conditions, such as exposure to cold or to the drug nocodazole. This stabilization is due mainly to polymer association with STOP proteins. In mouse, neurons express two major variants of these proteins, N‐STOP and E‐STOP (120 kDa and 79 kDa, respectively), whereas fibroblasts express F‐STOP (42 kDa) and two minor variants of 48 and 89 kDa. N‐ and E‐STOP induce microtubule resistance to both cold and nocodazole exposure, whereas F‐STOP confers microtubule stability only to the cold. Here, we investigated the expression of STOP proteins in oligodendrocytes and astrocytes in culture. We found that STOP proteins were expressed in precursor cells, in immature and mature oligodendrocytes, and in astrocytes. We found that oligodendrocytes express a major STOP variant of 89 kDa, which we called O‐STOP, and two minor variants of 42 and 48 kDa. The STOP variants expressed by oligodendrocytes induce microtubule resistance to the cold and to nocodazole. For astrocytes, we found the expression of two STOP variants of 42 and 48 kDa and a new STOP isoform of 60 kDa, which we called A‐STOP. The STOP variants expressed by astrocytes induce microtubule resistance to the cold but not to nocodazole, as fibroblast variants. In conclusion, astrocytes and oligodendrocytes express different isoforms of STOP protein, which show different microtubule‐stabilizing capacities. © 2004 Wiley‐Liss, Inc.
PV thermal systems: PV panels supplying renewable electricity and heat
Authors: van Helden Wim G. J. , van Zolingen Ronald J. Ch. , Zondag Herbert A. 
Published: September 2004

AbstractWith PV Thermal panels sunlight is converted into electricity and heat simultaneously. Per unit area the total efficiency of a PVT panel is higher than the sum of the efficiencies of separate PV panels and solar thermal collectors. During the last 20 years research into PVT techniques and concepts has been widespread, but rather scattered. This reflects the number of possible PVT concepts and the accompanying research and development problems, for which it is the general goal to optimise both electrical and thermal efficiency of a device simultaneously. The aspects that can be optimised are, amongst others, the spectral characteristics of the PV cell, its solar absorption and the internal heat transfer between cells and heat‐collecting system. Another important level of optimisation is for the PVT device geometry and the integration into a system. The electricity and heat demand and the temperature level of the heat determine the choice for a certain system set‐up. With an optimal design, PVT systems can supply buildings with 100% renewable electricity and heat in a more cost‐effective manner than separate PV and solar thermal systems and thus contribute to the long‐term international targets on implementation of renewable energy in the built environment. Copyright © 2004 John Wiley & Sons, Ltd.
Regenbögen in Raum und Zeit: Ultrakurze Laserpulse
Authors: Grunwald Rüdiger , Steinmeyer Günter 
Published: August 2004

AbstractFortschritte auf dem Gebiet der Ultrakurzpulslaser stellen an Forschung und Technik neue Herausforderungen hinsichtlich Formung und Diagnostik komplexer Lichtfelder. Für die Kontrolle der zeitlichen und räumlichen Spektraleigenschaften werden neuartige Optiken entwickelt. Spiegel aus Mehrfachschichten mit trickreichem Design gestatten optimale Pulskompression. Mit verbesserter SPIDER‐Technik werden kürzeste Femtosekundenpulse messbar. Dispersionsarme Dünnschicht‐Mikrooptiken erlauben eine Analyse von Wellenpaketen in Raum und Zeit. Mit derartigen Komponenten können auch optische Riesenwellen, so genannte X‐Pulse, erzeugt werden.
Falten und fliegen: Papierflieger und ihre Physik
Authors: Gruber Werner 
Published: August 2004

AbstractMit Papierfliegern können wichtige Eigenschaften der Aerodynamik anschaulich vermittelt werden: ein Blatt Papier, ein paar Faltungen und schon kann man experimentieren. Allerdings sind beim Trimmen des Fliegers einige Punkte zu beachten. Besonders wichtig ist die Y‐Stellung der Flügel, die ihm Flugstabilität verleiht. Ist der Flieger fertig, dann gilt es, die dem Modell am besten angepasste Wurftechnik herauszufinden. Dazu variiert man Wurfgeschwindigkeit und Abwurfwinkel. Den Boden kann ein Papierflieger auf vier prinzipiell verschiedenen Flugkurven erreichen: Optimal ist die Gerade, dann fliegt er am weitesten.
Weltlabor im Herzen Europas: 50 Jahre CERN
Authors: Schopper Herwig 
Published: August 2004

AbstractVor 50 Jahren wurde unter dem Dach der UNESCO das europäische Teilchenlabor CERN gegründet. Erstes Hauptziel war der Bau des Protonen‐Synchrotrons, das einen Umfang von 200 m hatte und eine maximale Energie von 28 GeV lieferte. Eine neue Ära begann mit dem Protonenbeschleuniger mit einer Energie von 400 GeV, dem Super‐Proton‐Synchrotron, SPS. Mit ihm wurden 1983 die W‐ und Z‐Bosonen der schwachen Wechselwirkung entdeckt. Es folgte 1989 als bislang größte Anlage der Large Elektron‐Positron‐Collider, LEP, mit 27 km Umfang. Er wurde im Oktober 2000 stillgelegt, um im Tunnel Platz für das neue Projekt Large Hadron Collider, LHC, zu schaffen.
Lavalampen: Spielwiese
Authors: Ucke Christian 
Published: August 2004

AbstractIm Innern eine Lavalampe befinden sich zwei nicht mischbare Flüssigkeiten unterschiedlicher Dichte und unterschiedlicher temperaturabhängiger Wärmeausdehnung. Bei der Erwärmung kommt es zum Auftrieb der “Lava” in der “Matrix.” Für den Dauerbetrieb muss sich die Matrix in ausreichendem Maße abkühlen können, sonst kommt der Vorgang zum Erliegen. Beim Bau einer Riesenlavalampe an der TU München zeigte es sich, dass eine einfache lineare Vergrößerung aller Bauteile nicht zu einer funktionierenden Lampe führt.
Quarks & Gluonen im Superrechner: Quantenchromodynamik auf dem Gitter
Authors: Gattringer Christof 
Published: August 2004

AbstractDie Quantenchromodynamik (QCD) ist die heute gültige Quantenfeldtheorie der starken Wechselwirkung. Sie beschreibt die Dynamik des Zusammenspiels von Quarks und Gluonen. Weil die Gluonen mit sich selbst wechselwirken können, ist der traditionelle Zugang über eine Störungsentwicklung nur bei sehr hohen Energien anwendbar. Die elegante Übertragung auf ein vierdimensionales Raumzeit‐Gitter macht die QCD der numerischen Berechnung auf Supercomputern zugänglich. Damit können zentrale Probleme wie etwa Hadronmassen oder Matrixelemente bestimmt werden. Heute ist die Gitter‐QCD so weit entwickelt, dass sie ein tieferes Verständnis von der Natur der starken Wechselwirkung ermöglicht.
Hybrid‐Solarzellen mit Nanopartikeln
Authors: Leute Angelika 
Published: August 2004

AbstractDie organische Photovoltaik auf der Basis halbleitender Polymere bietet eine kostengünstige Alternative zu Solarzellen aus Silizium. Allerdings weisen die organischen Materialien relativ schlechte Ladungstransporteigenschaften auf. Hybrid‐Solarzellen, in denen Polymere mit geeigneten anorganischen Halbleitern kombiniert sind, besitzen einerseits die praktischen Vorteile der Organik und andererseits die hohe Elektronenbeweglichkeit der anorganischen Materialien. Wissenschaftler der Technischen Universität Eindhoven haben kürzlich Hybrid‐Solarzellen vorgestellt, die aus einem halbleitenden Polymer mit Zinkoxid‐Nanopartikeln bestehen.
Gezielte Umladung einzelner Goldatome
Authors: Repp Jascha , Meyer Gerhard 
Published: August 2004

AbstractMit einem Rastertunnelmikroskop lassen sich nicht nur Oberflächen atomar abbilden, es kann auch dazu genutzt werden, Atome auf einer Oberfläche zu manipulieren. Auf diese Weise ist es erstmals gelungen, den Ladungszustand einzelner Goldatome zu verändern, ohne diese dabei seitlich zu verschieben.
Besucher vom Mond
Authors: TB  
Published: August 2004

AbstractEin in Oman entdeckter Meteorit mit dem Namen Sayh al Uhaymir (SaU) 169 kam vom Mond. Forscher der Universität Bern ermittelten die chemische Zusammensetzung des himmlischen Gesteins und konnten daraus durch Vergleich mit Gestein der Apollo‐Missionen und Satellitendaten den Herkunftsort relativ genau eingrenzen. Demnach stammt SaU 169 aus dem Bereich des 25 km großen Kraters Lalande im Mare Imbrium.
Ein Rastertunnelmikroskop im Selbstbau
Authors: Panzer Oliver , Fuchs Harald 
Published: August 2004

AbstractSeit Anfang der achtziger Jahre macht das Rastertunnelmikroskop die Untersuchung von Oberflächen mit atomarer Genauigkeit möglich. Engagierte Schüler und Studienanfänger haben nun die Möglichkeit, sich selbst ein Bild des “Sub‐Mikrokosmos” zu machen: die Universität Münster präsentiert im Internet eine komplette Anleitung für den Aufbau eines einfachen Rastertunnelmikroskops für unter 1000 €.
Einstein in Prag
Authors: Hoffmann Dieter 
Published: August 2004

AbstractIm Dezember 1910 meldete das Prager Tageblatt die Berufung Albert Einsteins als Professor für mathematische Physik an die Deutsche Universität Prag. Doch erst im Januar unterzeichnete der österreichische Kaiser Franz Joseph die Berufungsurkunde, und zum Frühjahrssemester 1911 nahm Einstein seine Tätigkeit in der Moldaumetropole auf.
Schatten, Bild und Spiegelung
Authors: Schlichting H. Joachim 
Published: August 2004

AbstractWenn Licht von einer Fläche sowohl spiegelnd als auch diffus reflektiert wird, kann es zu überraschenden Situationen kommen. Spiegelbild und Schatten sehen sich beide oft zum Verwechseln ähnlich – wenn man nicht genau genug hinschaut.
Das Rastertunnelmikroskop – von der Störstellenanalyse zum Nanowerkzeug
Authors: Hennig Jochen 
Published: August 2004

AbstractMit dem Rastertunnelmikroskop steht der Forschung ein Instrument zur atomgenauen Oberflächenuntersuchung zur Verfügung, das seit seiner Entwicklung 1982 bereits eine wechselhafte Geschichte hinter sich hat.
Der rastlose Amerikaner
Authors: Loos Andreas 
Published: August 2004

AbstractIn der Schule, die er mit acht Jahren zum ersten Mal von innen sah, hielt man ihn nicht für allzu helle – schließlich hinkte der Kleine oft hinter der Klasse her. Und es hat etwas Tragisches, wenn der wohl berühmteste Erfinder aller Zeiten und Halter von 2000 Patenten im Alter über seinen Vater sagt: “Er dachte, ich sei dumm. Und ich meinte schon fast selbst, ich sei ein Dummkopf.”