bluuebunny/crossref_metadata_2025 huggingface dataset:
Positive solutions to a third order nonlocal boundary value problem with a parameter
Authors: Szajnowska Gabriela , Zima Miros�awa
Published: January 2024

We present some sufficient conditions for the existence of positive solutions to a third order differential equation subject to nonlocal boundary conditions. Our approach is based on the Krasnosel'skii-Guo fixed point theorem in cones and the properties of the Green's function corresponding to the BVP under study. The main results are illustrated by suitable examples.
Meso‐SiO2–C12EO10OH–CF3SO3H—A Novel Proton‐Conducting Solid Electrolyte
Authors: Halla J.D. , Mamak M. , Williams D.E. , Ozin G.A.
Published: February 2003

This paper describes the synthesis and characterization of a novel mesostructured solid electrolyte composite material, denoted meso‐SiO2–C12EO10OH–CF3SO3H. A lyotropic non‐ionic surfactant–triflic acid–silicate liquid crystal is used as a supramolecular template for a “one‐pot” synthesis of the material. Within this structure, the oligoethyleneoxide head groups of the non‐ionic surfactant that is imbibed within the channels of hexagonal mesoporous silica act in a crown‐ether‐like fashion towards the protons. The structure and dynamics of the silicate–oligo(ethylene oxide)surfactant–triflic acid co‐assembly has been studied via several analytical techniques. These methods include polarized optical microscopy (POM), powder X‐ray diffraction (PXRD), transmission electron microscopy (TEM), multinuclear nuclear magnetic resonance (NMR) spectroscopy, thermogravimetric analysis (TGA), and Fourier transform (FT) Raman spectroscopy. Together these results imply that the protons coordinate to the oxygen atoms of the ethylene oxide units on the non‐ionic surfactant and the compound has the structural integrity of the silicified liquid crystal. AC impedance spectroscopy was used to determine the proton conductivity of the meso‐SiO2–C12EO10OH–CF3SO3H composite material at different relative humidity values giving some insight into its potential utility as a proton conducting solid electrolyte in a proton‐exchange membrane fuel cell.
Single‐Crystalline Films of the Homologous Series InGaO3(ZnO)m Grown by Reactive Solid‐Phase Epitaxy
Authors: Ohta H. , Nomura K. , Orita M. , Hirano M. , Ueda K. , Suzuki T. , Ikuhara Y. , Hosono H.
Published: February 2003

Single‐crystalline thin films of the homologous series InGaO3(ZnO)m (where m is an integer) are fabricated by the reactive solid‐phase epitaxy (R‐SPE) method. Specifically, the role of ZnO as epitaxial initiator layer for the growth mechanism is clarified. High‐temperature annealing of bilayer films consisting of an amorphous InGaO3(ZnO)5 layer deposited at room temperature and an epitaxial ZnO layer on yttria‐stabilized zirconia (YSZ) substrate allows for the growth of single‐crystalline film with controlled chemical composition. The epitaxial ZnO thin layer plays an essential role in determining the crystallographic orientation, while the ratio of the thickness of both layers controls the film composition.
Preparation of Metallic Films on Elastomeric Stamps and Their Application for Contact Processing and Contact Printing
Authors: Schmid H. , Wolf H. , Allenspach R. , Riel H. , Karg S. , Michel B. , Delamarche E.
Published: February 2003

The formation of permanent or reversible metallic patterns on a substrate has applications in microfabrication and analytical techniques. Here, we investigate how to metallize an elastomeric stamp, either for processing of a substrate mediated by the proximity between the metal on the stamp and an active layer on the substrate, or for contact printing of the metal from a stamp to a substrate. The stamps were made from poly(dimethylsiloxane) (PDMS) and were modified before metallizing them with Au by adding to or removing from their bulk mobile silicone residues, by oxidizing their surface with an O2‐plasma, by surface‐fluorination via silanization, or by priming them with a Ti layer. The interplay between the adhesion of the different layers defines two categories of application: contact processing and contact printing. Contact processing corresponds to keeping the metal on the stamp after contacting a substrate; it is reversible and nondestructive, and useful to define transient electrical contacts or quench fluorescence on a surface, for example. Contact printing occurs when the metal on the stamp adheres to the printed surface. Contact printing can transfer a metal, layers of metals, or an oxide onto a substrate with submicrometer lateral resolution. The transfer can be total or localized to the regions of contact, depending on the morphology of the metal on the stamp and/or the surface chemistry of the substrate.
Hybrid Solar Cells Based on Nanoparticles of CuInS2 in Organic Matrices
Authors: Arici E. , Sariciftci N.S. , Meissner D.
Published: February 2003

We report on solution‐processed hybrid solar cells consisting of a nanocrystalline inorganic semiconductor, CuInS2, and organic materials. Synthesis of quantized CuInS2 nanoparticles was performed using a colloidal route, where the particle surface was shielded by an organic surfactant. First attempts were made to use nanocrystalline CuInS2 with fullerene derivatives to form flat‐interface donor–acceptor heterojunction solar cells. We investigated also bulk heterojunctions by replacing the CuInS2 single layer by a blend of CuInS2 and p‐type polymer (PEDOT:PSS; poly(3,4‐ethylenedioxythiophene:poly(styrene sulfonic acid) in the same cell configuration. Bulk heterojunction solar cells show better photovoltaic response with external quantum efficiencies up to 20 %.
Pores in III–V Semiconductors
Authors: Föll H. , Langa S. , Carstensen J. , Christophersen M. , Tiginyanu I.M.
Published: February 2003

The paper reviews electrochemically etched pores in III–V compound semiconductors (GaP, InP, GaAs) with emphasis on nucleation and formation mechanisms, pore geometries and morphologies, and to several instances of self‐organization. Self‐ organization issues include the formation of single‐crystalline two‐dimensional hexagonal arrays of pores with lattice constants as small as 100 nm found in InP, synchronized and unsynchronized diameter oscillations coupled to current and voltage oscillations, and pore domain formation. The findings are discussed in relation to pores observed in silicon. Some novel properties of the porous layers obtained in III–V compounds are briefly described.
New Iridium Complexes as Highly Efficient Orange–Red Emitters in Organic Light‐Emitting Diodes
Authors: Duan J.P. , Sun P.P. , Cheng C.H.
Published: February 2003

Two new iridium complexes with pyrazine derivatives as ligands (see Figure) were synthesized. The electroluminescent devices based on these metal complexes emit orange–red light at ∼ 610 nm with exceedingly high brightness and external quantum, current, and power efficiencies.
Nanobelts, Nanocombs, and Nanowindmills of Wurtzite ZnS
Authors: Ma C. , Moore D. , Li J. , Wang Z.L.
Published: February 2003

Nanostructures of wurtzite‐structured zinc sulfide, which is unlikely to be stable at room temperature under conventional conditions, have been synthesized by a simple physical process. Morphologies with belt‐ (see Figure), saw‐, comb‐, and windmill‐like nanostructures have been observed and characterized using a variety of imaging techniques.
Synthesis of Cable‐Like Copper Nanowires
Authors: Yen M.‐Y. , Chiu C.‐W. , Hsia C.‐H. , Chen F.‐R. , Kai J.‐J. , Lee C.‐Y. , Chiu H.‐T.
Published: February 2003

Cable‐like copper nanowires (1–10 μm in length and 15–80 nm in diameter) with an insulating poly(dimethylsiloxane) (PDMS) sheath (5–10 nm in thickness, see Figure) have been successfully synthesized by a solvent‐free reaction between CuCl and (Me3Si)4Si in the presence of PDMS in sealed tubes. The wire formation mechanism is proposed to be vapor–solid reaction growth.
Metallic Sub‐Nanometer MoS2–xIy Nanotubes
Authors: Remskar M. , Mrzel A. , Sanjines R. , Cohen H. , Lévy F.
Published: February 2003

MoS2–x nanotubes of sub‐nanometer diameter show metallic behavior when studied using scanning tunnelling microscopy. Single nanotubes and those self‐assembled into narrow MoS2–xIy bundles can be manipulated by voltage pulses to form nanotube associations. Spontaneous alignment, manipulation using an electrical field gradient, and easy cutting to size the tubes enables their use in advanced nano‐device technology.
A Simple Method for the Attachment of Polymer Films on Solid Substrates
Authors: Yan M. , Harnish B.
Published: February 2003

The immobilization of polymer thin films on solid substrates has been achieved using a very simple method, involving spin coating the polymer, followed by UV irradiation. A robust film remains on the substrate surface after solvent extraction. The procedure could be employed to fabricate patterned polymer thin films via photolithography (see Figure).
Enhanced Electrical Conductivity of Self‐Assembled, Layered Molecular Composites of Metallo‐Backbone Polymer and Polyaniline
Authors: Lee S.‐H. , Yuan Z. , Lee C.‐W.
Published: February 2003

Polymers with metallo backbones and pendant alkoxy groups (see Figure) are intercalated into a conducting polymer system of polyaniline–camphor sulfonic acid (PANI–CSA). The use of properly designed self‐assembled, layered metallic backbones, which are compatible with anions and Lewis bases of the doped PANI, is shown to improve not only the electrical conductivity but also the solubility of PANI–CSA.
Optical identifications in the Marano field XMM‐Newton survey
Authors: Lamer G. , Wagner S. , Zamorani G. , Mignoli M. , Hasinger G. , Giedke K. , Staubert R.
Published: February 2003

The “Marano field”, a deep optical quasar survey field, has been observed by the XMM Newton EPIC camera with 16 overlapping pointings totalling at ∼ 120 ksec integration time. Source detection in the merged observations resulted in more than 600 X‐ray sources. Here we present the status of optical follow up observations which were undertaken to identify and classify the newly found X‐ray sources.
The SHEEP survey: Observing the hardest of the hard with Chandra
Authors: Georgantopoulos I. , Nandra K. , Brotherton M. , Ptak A. , Zezas A. , Papadakis I.
Published: February 2003

Our ASCA hard (5‐10 keV) SHEEP (Survey High Energy Extragalactic Populations) survey covers 39 deg2 and contains 69 sources down to a limiting flux of 10–13 erg cm–2 s–1. 35 of the sources have ROSAT counterparts and therefore reliable optical identifications. The ‘soft’ SHEEP/ROSAT sample appears to be dominated by QSOs and Seyfert‐1 galaxies. For the remaining 34 sources we are obtaining Chandra snapshot (5 ksec) and KPNO spectroscopic observations. Here, we report some preliminary results from this campaign. Although the sample with spectroscopic identifications is still very limited, it appears that we are observing a mixture of QSOs (one at a redshift of z = 0.5 is heavily obscured) and Narrow Line Galaxies.
The CYDER survey: first results
Authors: Castander F.J. , Treister E. , Maza J. , Coppi P.S. , Maccarone T.J. , Zepf S.E. , Guzmán R. , Ruiz M.T.
Published: February 2003

We present the Calán‐Yale Deep Extragalactic Research (CYDER) Survey. The broad goals of the survey are the study of stellar populations, the star formation history of the universe and the formation and evolution of galaxies. The fields studied include Chandra deep pointings in order to characterize the X‐ray faint populations. Here we present the results on the first fields studied. We find that the redshift distribution is consistent with that found in the Chandra Deep Field North. The distribution of hardness ratios is, however, softer in our sample. We find a high redshift quasar, CXOCY J125304.0‐090737 at z = 4.179, which suggests that the abundance of low luminosity high redshift quasars may be larger than what would be expected from reasonable extrapolations from the quasar optical luminosity function.
Galactic X‐ray surveys
Authors: Ebisawa K. , Yamauchi S. , Bamba A. , Ueno M. , Senda A.
Published: February 2003

We review highlights of the results obtained from recent Galactic X‐ray survey observations, in particular ASCA Galactic center and plane surveys and our Chandra deep survey on the (l, b) ≈ (28°.5, 0°.0) region. Strong hard X‐ray diffuse components are observed from Galactic ridge, center and bulge, and they have both thermal and non‐thermal spectral components. Dozens of discrete and extended sources have been discovered on the Galactic plane, which also indicate thermal and/or non‐thermal X‐ray energy spectra. They are often associated with radio sources and are considered to be SNR candidates. Most of the hard X‐ray point sources in the outer part of the Galactic plane are considered to be background AGNs, while fraction of the Galactic hard X‐ray sources (such as quiescent dwarf novae) increases toward the Galactic center. Most of the soft X‐ray sources on the Galactic plane are presumably nearby active stars.
The XMM‐Newton serendipitous source catalogue
Authors: Watson M.G. , Pye J.P. , Denby M. , Osborne J.P. , Barret D. , Boller Th. , Brunner H. , Ceballos M.T. , Dellaceca R. , Fyfe D.J. , Lamer G. , Maccacaro T. , Michel L. , Motch C. , Pietsch W. , Saxton R.D. , Schröder A.C. , Stewart I.M. , Tedds J.A. , Webb N.
Published: February 2003

We describe the production, properties and scientific potential of the XMM‐Newton catalogue of serendipitous X‐ray sources. The first version of this catalogue is nearing completion and is planned to be released in early 2003.
Do sub‐mm sources and quasars form an evolutionary sequence?
Authors: Almaini O.
Published: February 2003

The high redshift sub‐mm sources discovered by SCUBA are widely believed to represent the dust‐enshrouded formation of massive elliptical galaxies. Given the strong evidence for a link between the formation of the spheroid and the growth of the central black hole, one might expect to see a luminous quasar at the nucleus of every SCUBA source. Somewhat surprisingly, however, only a very small fraction (∼ 5%) are detected in X‐rays. In this paper I discuss some of the implications of these results and discuss the accumulating evidence that sub‐mm sources and quasars may represent different stages in the evolutionary sequence of a massive proto‐spheroid.
ROSITA
Authors: Predehl P. , Friedrich P. , Hasinger G. , Pietsch W.
Published: February 2003

The Max‐Planck‐Institut für extraterrestrische Physik, the Astrophysikalisches Institut Potsdam, and the Institut für Astronomie und Astrophysik of the university of Tübingen, together with European cooperation partners and ESA, plan to install an X‐ray telescope on the International Space Station (ISS). The mission ROSITA (ROentgen Survey with an Imaging Telescope Array) will perform the first imaging all‐sky survey in the medium energy X‐ray range up to 10 keV with an unprecedented spectral and angular resolution. The main scientific goals are (1) to detect systematically all obscured accreting Black Holes in nearby galaxies and altogether about 50,000 AGN in the 2‐10 keV band, (2) to detect the hot intergalactic medium of several ten thousand galaxy clusters, and (3) to study in detail the physics of galactic X‐ray source populations, like pre‐main sequence stars, supernova remnants, and X‐ray binaries. In the hard X‐ray band (above 2 keV) the ROSITA survey will have a hundred times higher sensitivity and a hundred times better angular resolution than the last all‐sky survey in this band, which was performed about 25 years ago. In the soft band (0.5‐2 keV) the ROSITA survey will be more sensitive and have a substantially better energy and also angular resolution than the ROSAT all‐sky survey. The telescope will consist of seven 27‐fold nested Wolter‐1 mirror systems, the type already flown on ABRIXAS, and a novel detector system currently being developed by MPE on the basis of the successful XMM pn‐CCD technology. Major improvements of the new camera are a higher time and energy resolution.
DUET – The Dark Universe Exploration Telescope
Authors: Jahoda K.
Published: February 2003

DUET, a proposed NASA Midex class mission, will produce a catalog of ∼ 20,000 X‐ray selected clusters and groups of galaxies suitable for detailed cosmological investigations. We present the cosmological constraints achievable by DUET, the functional requirements of the survey, and briefly describe an instrument/mission design capable of achieving these requirements. The advantages of an X‐ray survey for constraining the nature and amount of dark energy and dark matter are emphasized. Constraints on cosmological parameters are precise and complementary to other approaches. The density of dark energy, dark matter, and neutrinos will be measured with a statistical uncertainty of 0.5%, 0.5%, and 0.2% of the critical density and the dark energy equation of state can be measured to ±0.2 if dark energy and dark matter contribute ∼2/3 and ∼1/3 of the critical density as currently believed. DUET is a multi‐national collaboration led by GSFC with substantial contributions from groups in the US, Europe, and Japan.
Flow cytometric detection of β‐D‐glucuronidase gene in wild‐type bacterial cells using in‐situ PCR
Authors: Sachidanandham Ramaiah , Gin Karina Yew‐Hoong
Published: February 2003

An in situ PCR‐based flow cytometry method useful for monitoring the presence or absence of the β‐D‐glucuronidase gene in Escherichia coli has been developed. A single‐step fixation and permeabilization procedure, which maintained cell integrity at the elevated temperatures used during thermal cycling in the presence of PCR reagents, was demonstrated. We have chosen a shorter DNA sequence of length 147 bp for the PCR. Cells subjected to in situ PCR using fluorescein‐12‐dUTP as a label, showed the presence of uid both in epifluorescence microscopic examination and flow cytometric analysis. Multi‐parametric analysis of flow cytometric profiles revealed that the efficiency of labeling was found to be high. The potential of in situ PCR for the detection of uid in intact coliform cells was then successfully tested with a fecal coliform isolated from the coastal waters of Singapore. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 82: 127–133, 2003.
Free intracellular amino acid pools during autonomous oscillations in Saccharomyces cerevisiae
Authors: Hans Michael A. , Heinzle Elmar , Wittmann Christoph
Published: February 2003

In the present work dynamic changes of free intracellular amino acid pools during autonomous oscillations of Saccharomyces cerevisiae were quantified in glucose‐limited continuous cultivations. At a dilution rate of D = 0.22 h−1 cyclic changes with a period of 120 min were found for many variables such as carbon dioxide production rate, dissolved oxygen, pH, biomass content, and various metabolite concentrations. On the basis of the observed dynamic patterns, free intracellular amino acids were classified to show oscillatory, stationary, or chaotic behavior. Amino acid pools such as serine, alanine, valine, leucine, or lysine were subjected to clear oscillations with a frequency of 120 min, identical to that of other described cultivation variables, indicating that there is a direct correlation between the periodic changes of amino acid concentrations and the metabolic oscillations on the cellular level. The oscillations of these amino acids were unequally phase‐delayed and had different amplitudes of oscillation. Accordingly, they exhibited different patterns in phase plane plots vs. intracellular trehalose. Despite the complex and marked metabolic changes during oscillation, selected intracellular amino acids such as histidine, threonine, isoleucine, or arginine remained about constant. Concentrations of glutamate and glutamine showed a chaotic behavior. However, the ratio of glutamate to glutamine concentration was found to be oscillatory, with a period of 60 min and a corresponding figure eight‐shaped pattern in a plot vs. trehalose concentration. Considering the described diversity, it can be concluded that the observed periodic changes are neither just the consequence of low or high rates of protein biosynthesis/degradation nor correlated to changing cell volumes during oscillation. The ratio between doubling time (189 min) and period of oscillation of intracellular amino acids (120 min) was 1:6. The fact that there is a close relationship between doubling time and period of oscillation underlines that the described autonomous oscillations are cell‐cycle‐associated. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 82: 143–151, 2003.
Metabolic analysis of the synthesis of high levels of intracellular human SOD in Saccharomyces cerevisiae rhSOD 2060 411 SGA122
Authors: Gonzalez Ramon , Andrews Barbara A. , Molitor Julia , Asenjo Juan A.
Published: February 2003

The synthesis of human superoxide dismutase (SOD) in batch cultures of a Saccharomyces cerevisiae strain using a glucose‐limited minimal medium was studied through metabolic flux analysis. A stoichiometric model was built, which included 78 reactions, according to metabolic pathways operative in these strains during respirofermentative and oxidative metabolism. It allowed calculation of the distribution of metabolic fluxes during diauxic growth on glucose and ethanol. Fermentation profiles and metabolic fluxes were analyzed at different phases of diauxic growth for the recombinant strain (P+) and for its wild type (P−). The synthesis of SOD by the strain P+ resulted in a decrease in specific growth rate of 34 and 54% (growth on glucose and ethanol respectively) in comparison to the wild type. Both strains exhibited similar flux of glucose consumption and ethanol synthesis but important differences in carbon distribution with biomass/substrate yields and ATP production 50% higher in P−. A higher contribution of fermentative metabolism, with 64% of the energy produced at the phosphorylation level, was observed during SOD production. The flux of precursors to amino acids and nucleotides was higher in the recombinant strain, in agreement with the higher total RNA and protein levels. Lower specific growth rates in strain P+ appear to be related to the decrease in the rate of synthesis of nonrecombinant protein, as well as a decrease in the activities of the pentose phosphate (PP) pathway and TCA cycle. A very different way of entry into the stationary phase was observed for each strain: in the wild‐type strain most metabolic fluxes decreased and fluxes related to energy reserve synthesis increased, while in the P+ strain the flux of 22 reactions (including PP pathway and amino acids biosynthesis) related to SOD production increased their fluxes. Changes in SOD production rates at different physiological states appear to be related to the differences in building blocks availability between respirofermentative and oxidative metabolism. Using the present expression system, ideal conditions for SOD synthesis are represented by either active growth during respirofermentative metabolism or transition from a growing to a nongrowing state. An increase in SOD flux could be achieved using an expression system nonassociated to growth and potentially eliminating part of the metabolic burden. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 82: 152–169, 2003.
Compression of biocompatible liquid‐filled HSA‐alginate capsules: Determination of the membrane mechanical properties
Authors: Carin Muriel , Barthès‐Biesel Dominique , Edwards‐Lévy Florence , Postel Caroline , Andrei Diana Cristina
Published: February 2003

Compression experiments between two parallel plates are performed on a series of biocompatible HSA‐alginate capsules with two different membrane thicknesses. The capsule geometry and size as well as the average membrane thickness are first measured. The compression set‐up is fitted with a sensitive force transducer that allows measurement of the compression force as a function of plate separation. The response of the capsule is analyzed by assuming different constitutive models for the membrane, where the shear and surface dilatation effects are accounted. An apparent area dilatation modulus is then computed for different values of the plate separation and required to remain constant as the capsule deformation increases. This allows identification of plausible constitutive laws for the membrane material. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 82: 207–212, 2003.
Self‐assembly of Pseudomonas fluorescens lipase into bimolecular aggregates dramatically affects functional properties
Authors: Fernández‐Lorente Gloria , Palomo José M. , Fuentes Manuel , Mateo Cesar , Guisán José M. , Fernández‐Lafuente Roberto
Published: February 2003

It has been found that lipase from Pseudomonas fluorescens (PFL) is able to aggregate into bimolecular structures (MW around 66 kD) even at moderate enzyme concentrations. At very low enzyme concentrations and in the presence of detergents, the same enzyme displayed a unimolecular structure with a molecular weight of 33 kD. Both enzyme structures displayed different functional properties. First, the bimolecular structure was much more stable than the unimolecular species (the bimolecular structure maintained over 80% of initial activity after 72 hours at 45°C, while the unimolecular structure retained only around 30% of initial activity after 4 hours of incubation under the same experimental conditions); and the bimolecular form presented a higher optimal T. Second, the unimolecular form showed a much lower KM for ethyl butyrate than the bimolecular form. Third, the interfacial activation in biphasic substrate‐aqueous milieu was higher for the bimolecular form. Fourth, the unimolecular structure was less active but much more enantioselective than the unimolecular species in the model reaction used. It is proposed that the bimolecular aggregates of PFL might be formed by two open lipase molecules (mutual interfacial activation), in intimate contact, and that the bimolecular form represents an example of “pseudo‐quaternary” structure. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 82: 232–237, 2003.
Oxidation of 4‐bromophenol by the recombinant fused protein cellulose‐binding domain‐horseradish peroxidase immobilized on cellulose
Authors: Levy Ilan , Ward Gary , Hadar Yitzhak , Shoseyov Oded , Dosoretz Carlos G.
Published: February 2003

A fused protein consisting of cellulose‐binding domain (CBD) and horseradish peroxidase (HRP) was constructed and expressed in Escherichia coli. Refolded recombinant CBD‐HRP (95% recovery yield) was bound to microcrystalline cellulose and applied for the oxidation of a model toxic phenol, 4‐bromophenol (BP). Oxidation of BP by CBD‐HRP resulted in the formation of dimers to pentamers as evidenced by mass spectrometry analysis. When immobilized, the vast majority of the oxidation products adsorbed to the cellulose matrix. CBD‐HRP (0.75 pyrogallol units) bound to 0.1 g cellulose was packed in a column, connected to an HPLC pump and monitoring system, and column performance and capacity were studied under various operating conditions. When performance was studied as a function of BP loading rate at a constant H2O2 loading rate of 1500 nmol/min, Vappmax and Kmapp were calculated to be 5.29 ± 0.46 μmol mL min and 644.9 ± 114.3 μM, respectively. Immobilized CBD‐HRP exhibited enhanced stability to H2O2 and oxidized considerably more BP than free CBD‐HRP. Inclusion of gelatin, which suppresses product‐dependent inactivation, further increased the amount of BP oxidation. These findings may have potential impact in terms of enzyme supply in high‐rate treatment of wastewater contaminated with toxic phenols, since the susceptibility of peroxidases to both H2O2 ‐ and product‐dependent inactivation demands continuous supply of fresh enzyme. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 82: 223–231, 2003.
Proteome analysis of the plasma membrane of Mycobacterium tuberculosis
Authors: Sinha Sudhir , Arora Shalini , Kosalai K. , Namane Abdelkader , Pym Alex S. , Cole Stewart T.
Published: February 2003

The plasma membrane of Mycobacterium tuberculosis is likely to contain proteins that could serve as novel drug targets, diagnostic probes or even components of a vaccine against tuberculosis. With this in mind, we have undertaken proteome analysis of the membrane of M. tuberculosis H37Rv. Isolated membrane vesicles were extracted with either a detergent (Triton X114) or an alkaline buffer (carbonate) following two of the protocols recommended for membrane protein enrichment. Proteins were resolved by 2D‐GE using immobilized pH gradient (IPG) strips, and identified by peptide mass mapping utilizing the M. tuberculosis genome database. The two extraction procedures yielded patterns with minimal overlap. Only two proteins, both HSPs, showed a common presence. MALDI–MS analysis of 61 spots led to the identification of 32 proteins, 17 of which were new to the M. tuberculosis proteome database. We classified 19 of the identified proteins as ‘membrane‐associated’; 14 of these were further classified as ‘membrane‐bound’, three of which were lipoproteins. The remaining proteins included four heat‐shock proteins and several enzymes involved in energy or lipid metabolism. Extraction with Triton X114 was found to be more effective than carbonate for detecting ‘putative’ M. tuberculosis membrane proteins. The protocol was also found to be suitable for comparing BCG and M. tuberculosis membranes, identifying ESAT‐6 as being expressed selectively in M. tuberculosis. While this study demonstrates for the first time some of the membrane proteins of M. tuberculosis, it also underscores the problems associated with proteomic analysis of a complex membrane such as that of a mycobacterium. Copyright © 2002 John Wiley & Sons, Ltd.
Heterologous expression and purification systems for structural proteomics of mammalian membrane proteins
Authors: Mus‐Veteau Isabelle
Published: February 2003

Membrane proteins (MPs) are responsible for the interface between the exterior and the interior of the cell. These proteins are implicated in numerous diseases, such as cancer, cystic fibrosis, epilepsy, hyperinsulinism, heart failure, hypertension and Alzheimer's disease. However, studies on these disorders are hampered by a lack of structural information about the proteins involved. Structural analysis requires large quantities of pure and active proteins. The majority of medically and pharmaceutically relevant MPs are present in tissues at very low concentration, which makes heterologous expression in large‐scale production‐adapted cells a prerequisite for structural studies. Obtaining mammalian MP structural data depends on the development of methods that allow the production of large quantities of MPs. This review focuses on the different heterologous expression systems, and the purification strategies, used to produce large amounts of pure mammalian MPs for structural proteomics. Copyright © 2002 John Wiley & Sons, Ltd.
SMAD7 is a prognostic marker in patients with colorectal cancer
Authors: Boulay Jean‐Louis , Mild Gabriele , Lowy Adam , Reuter Juergen , Lagrange Magali , Terracciano Luigi , Laffer Urban , Herrmann Richard , Rochlitz Christoph
Published: February 2003

Chromosomal region 18q21 is frequently deleted in colorectal cancer (CRC) and is associated with poor prognosis. Potential tumor suppressor mechanisms altered by 18q21 deletion include mediation of TGFβ signaling by SMADs. Following the definition of SMAD4 deletion as a negative predictive marker for chemotherapy benefit in patients with CRC, we aimed to evaluate the clinical relevance of the deletion of other SMAD genes clustered in this region: SMAD2 and SMAD7 in 264 CRC biopsies from a previous clinical study. In contrast to SMAD2 deletion, for which no clinical relevance was observed, hazard ratios (HR) in a multivariate analysis associated with SMAD7 deletion [overall survival (OS): HR = 0.43, p = 0.0012; disease‐free survival (DFS): HR = 0.50, p = 0.0033] indicated a favorable outcome for these patients. In addition, SMAD7 duplication had a hazardous effect on survival [OS: HR = 2.10, p = 0.020; DFS: HR = 2.06, p = 0.015]. Moreover, the HRs associated with one additional copy of SMAD7 were 1.76, p = 0.00024 [OS] and 1.64, p = 0.00048 [DFS] respectively, showing a graded effect of SMAD7 on patient outcome depending on gene copy number that suggests a dose‐and‐effect basis. Since SMAD7 blocks TGFβ signaling, these data are consistent with the loss of SMAD7 rendering carcinoma cells more sensitive to cell growth arrest/apoptotic effect of TGFβ, whereas gain of SMAD7 function might result in TGFβ resistance, thereby emphasizing the role of TGFβ in tumor suppression. © 2003 Wiley‐Liss, Inc.
Optimal excitation‐emission wavelengths for autofluorescence diagnosis of bladder tumors
Authors: Zheng Wei , Lau Weber , Cheng Christopher , Soo Khee Chee , Olivo Malini
Published: February 2003

Tissue autofluorescence depends on endogenous fluorophores in the tissue, which undergo a change associated with malignant transformation. This change can be detected as an alteration in the spectral profile and intensity of autofluorescence. Our purpose was to determine the optimal excitation and emission wavelengths for autofluorescence diagnosis of bladder cancer. A total of 52 bladder tissue specimens were obtained from 25 patients undergoing mucosal biopsies or surgical resections of bladder tumors. Light‐induced autofluorescence measurements were performed to study the spectroscopic differences between normal and malignant bladder tissue. Fluorescence excitation wavelengths varying from 220 to 500 nm were used to induce tissue autofluorescence, and emission spectra were measured in the 280–700 nm range. These spectra were then combined to construct 2‐dimensional fluorescence excitation‐emission matrices (EEMs). Significant changes in fluorescence intensity of EEMs were observed between normal and tumor bladder tissues, the most marked differences being at the excitation wavelengths of 280 and 330 nm. The diagnostic algorithm based on the combination of the fluorescence peak intensity ratios of I350/I470 at 280 nm excitation and I390/I470 at 330 nm excitation yielded a sensitivity of 100% [95% confidence interval (CI) 0.95–1.0] and specificity of 100% (95% CI 0.90–1.0). The results of the present fluorescence EEM study demonstrate that autofluorescence spectroscopy can distinguish malignant from normal bladder tissue and that excitation wavelengths of 280 and 330 nm are the most significant for differentiation between normal and malignant bladder mucosae with a high degree of diagnostic accuracy. © 2003 Wiley‐Liss, Inc.
Tumor‐specific antigens in cutaneous T‐cell lymphoma: Expression and sero‐reactivity
Authors: Eichmüller Stefan , Usener Dirk , Thiel Daniela , Schadendorf Dirk
Published: February 2003

Cutaneous T‐cell lymphoma (CTCL) is a heterogeneous group of extra‐nodal non‐Hodgkin lymphomas with primary manifestation in the skin with poor treatment options in the advanced stages. As basis for future immune‐therapeutic strategies we have investigated the possible expression of tumor‐specific targets in CTCL focusing mainly on so‐called cancer‐germline genes. cDNAs derived from 20 CTCL tissues and 4 CTCL cell lines were tested with 15 gene‐specific and 4 gene family‐specific primers by RT‐PCR and confirmative Northern blotting. The most frequently detected mRNAs were LAGE‐1 (55% with only partial coexpression of the splicing variants), cTAGE‐1 (35%), MAGE‐A9 (27%) and the GAGE‐3–7 group (35%). Furthermore, we could detect NY‐ESO‐1 (21%) and a MAGE‐A subgroup (15%), whereas sub‐specification of the latter proved absence of MAGE‐A1, ‐A2, ‐A3, ‐A6 and ‐A12. SCP‐1 was found in only one specimen and a several antigens could not been detected in any tumor tissue or cell line (MAGE‐B, GAGE‐1,2,8 and all 4 RAGE genes). 90% of all CTCL samples were positive for at least 1 of the frequent mRNAs in RT‐PCR (LAGE‐1, NY‐ESO‐1, cTAGE‐1, MAGE‐A9, or GAGE‐3to7). Using a secondary SEREX approach we could detect sero‐reactivity in sera of CTCL patients against recombinant cTAGE‐1 (10/29), GAGE (3/19), MAGE‐A1 (1/18), ‐A3 (1/18), ‐A6 (2/18) and ‐A9 (4/18) protein, but not against LAGE‐1a, MAGE‐A4b or MAGE‐A12 protein (n = 19). We conclude, that certain cancer‐germline genes can be detected frequently in CTCL and are able to elicit a systemic immune response. These candidate genes might therefore be promising targets for immunotherapeutic interventions in CTCL. © 2003 Wiley‐Liss, Inc.
Macrophages in tumor‐draining lymph node with different characteristics induce T‐cell apoptosis in patients with advanced stage‐gastric cancer
Authors: Takahashi Akihiro , Kono Koji , Ichihara Fumiko , Sugai Hidemitsu , Amemiya Hideki , Iizuka Hidehiko , Fujii Hideki , Matsumoto Yoshiro
Published: February 2003

A host's immune‐defense system is suppressive by many factors in patients with cancer. We have previously shown one possible mechanism behind the T‐cell dysfunction, whereby H2O2 secreted from macrophages in tumor‐draining lymph node (MTDL) induced T‐cell dysfunction with down‐regulation of TCR ζ molecules. In the present study, we analyzed how MTDL affect T cells, with a particular focus on T‐cell apoptosis, by co‐culturing MTDL with autologous peripheral blood T cells in gastric cancer. Moreover, we characterized the MTDL according to surface marker, oxygen‐burst capacity and intracellular cytokine status. T‐cell apoptosis was significantly induced in comparison to T‐cell alone control in patients with advanced disease, concomitant to the elevated caspase activity and following impaired T‐cell function. In patients with early disease, no significant difference was seen in the proportions of T cells that underwent apoptosis between T cells plus MTDL and T cells alone. Moreover, the addition of a selective scavenger of H2O2, catalase inhibited the apoptosis of T cells co‐cultured with MTDL in patients with advanced disease. In the characterization of MTDL, the production of H2O2 in MTDL from advanced disease was significantly higher than that in early disease. The amounts of intracellular IL‐10 and IL‐12 in MTDL in advanced disease were significantly higher than those in early disease. These results indicated that MTDL induced apoptosis of autologous T cells and this T‐cell dysfunction was mediated by H2O2 derived from MTDL. Furthermore, the characteristics of MTDL including the capacity of oxygen‐burst and intracellular cytokine production were different depending on the disease progression. © 2003 Wiley‐Liss, Inc.
Health profiles in 5836 long‐term cancer survivors
Authors: Schultz Pamela N. , Beck Martha L. , Stava Charles , Vassilopoulou‐Sellin Rena
Published: February 2003

Increasingly, prolonged survival follows the diagnosis of cancer. Cancer therapies result in complex and lasting health effects that create unique health‐care needs for the survivors but are poorly understood (especially in survivors of adult cancers). Cancer survivors were asked to respond to a mailed health survey and provide medical and social information pertaining to their cancer experience. Information about demographics and perceived disease‐related medical problems was analyzed. We analyzed the response of 5,836 survivors of adult cancers. Two‐thirds of the responses came from women, and the response rate was 51% in both sexes. The mean interval since cancer diagnosis was 18.0 ± 8.5 years. Younger survivors and men were more likely to report that cancer had affected their health. The health effect most commonly reported by survivors was arthritis/osteoporosis (26% of respondents). Survivors of Hodgkin's disease prominently reported thyroid and lung problems (33.8% of responders with the diagnosis). Prior diagnosis of lymphoma was associated with frequent mention of memory loss (14.7%). The passage of time decreased some perceived effects (memory loss) but increased others (arthritis/osteoporosis, cataracts). Compared with the general population, the incidence of several age‐ and gender‐adjusted health conditions in cancer survivors is different. This group of cancer survivors reported generally good health but outlined multiple lasting medical problems. The health survey described represents 1 approach to the development of comprehensive information about the health needs of cancer survivors. © 2003 Wiley‐Liss, Inc.
The molecular pharmacology of symplostatin 1: A new antimitotic dolastatin 10 analog
Authors: Mooberry Susan L. , Leal Rachel M. , Tinley Tina L. , Luesch Hendrik , Moore Richard E. , Corbett Thomas H.
Published: February 2003

Symplostatin 1, an analog of dolastatin 10, was recently isolated from cyanobacteria of the genus Symploca. Symplostatin 1 is a potent inhibitor of cell proliferation with IC50 values in the low nanomolar range and it exhibits efficacy against a variety of cancer cell types. Symplostatin 1 caused the formation of abnormal mitotic spindles and accumulation of cells in metaphase at concentrations that had only minor effects on interphase microtubules. At higher concentrations, symplostatin 1 caused the loss of interphase microtubules. Cell cycle analysis revealed that symplostatin 1 caused G2/M arrest, consistent with its effects on mitotic spindles. Symplostatin 1 initiated the phosphorylation of Bcl‐2, formation of micronuclei and activation of caspase 3, indicating induction of apoptosis. The cellular effects of symplostatin 1 are consistent with other antimitotic tubulin‐targeting drugs. Tubulin polymerization experiments indicated that symplostatin 1 potently inhibits the assembly of purified tubulin, suggesting that tubulin may be its intracellular target. Some microtubule‐targeting agents are reported to have antiangiogenic activity and therefore the effects of symplostatin 1 on endothelial cell proliferation and invasion were evaluated. Symplostatin 1 was found to be a potent inhibitor of both endothelial cell proliferation and invasion. Because of its potent and broad activity in vitro, symplostatin 1 was evaluated in vivo. Symplostatin 1 was active against murine colon 38 and murine mammary 16/C; however, it was poorly tolerated and the mice were slow to recover from the toxicity. The data indicate that symplostatin 1 has a mechanism of action similar to dolastatin 10. © 2003 Wiley‐Liss, Inc.
Conditions ensuring starter induced 1‐factorizations are not isomorphic
Authors: Ihrig E.
Published: February 2003

In general, it is difficult to determine whether two starter induced 1‐factorizations of K2n are isomorphic. However, when one of the 1‐factorizations has a unique starter group to within conjugacy, we show that two starter induced 1‐factorizations on K2n are isomorphic, if and only if, the corresponding starters are isomorphic. Two starters are isomorphic if there is a group isomorphism between the respective starter groups which takes one starter to the other. It is relatively easy to check whether starters are isomorphic in many examples. The difficulty comes in showing there is a unique starter group to within conjugacy. A number of sufficient conditions for this are given; one such condition is the assumption that the 1‐factorization be irreducible, a condition which applies to all almost perfect 1‐factorizations. Also, generalized Mullin Nemeth starters are introduced and discussed in this context. © 2003 Wiley Periodicals, Inc. J Combin Designs 11: 124–143, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jcd.10023
Some results on the existence of large sets of t‐designs
Authors: Khosrovshahi G. B. , Tayfeh‐Rezaie R.
Published: February 2003

A set of trivial necessary conditions for the existence of a large set of t‐designs, LS[N](t,k,ν), is $N\big | {{\nu \hskip -3.1 \nu}-i \choose k-i}$ for i = 0,…,t. There are two conjectures due to Hartman and Khosrovshahi which state that the trivial necessary conditions are sufficient in the cases N = 2 and 3, respectively. Ajoodani‐Namini has established the truth of Hartman's conjecture for t = 2. Apart from this celebrated result, we know the correctness of the conjectures for a few small values of k, when N = 2 and t ≤ 6, and also when N = 3 and t ≤ 4. In this article, we show that similar results can be obtained for infinitely many values of k. © 2003 Wiley Periodicals, Inc. J Combin Designs 11: 144–151, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jcd.10027
Lower bounds estimation of factor‐covering design sizes
Authors: Ido Nobuhiko , Kikuno Tohru
Published: February 2003

Factor‐covering designs have been studied with the aim of making efficient suites of test cases for software testing. One of the major concerns in these studies is the construction of factor‐covering designs of smaller sizes. In this paper, we propose a method of estimating the lower bounds of the sizes. The proposed method is based on two assumptions that a test design has parameters of the same range, and that all the values in the range are tested equally. © 2003 Wiley Periodicals, Inc. J Combin Designs 11: 89–99, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jcd.10039
Intracellular fibroblast growth factor produces effects different from those of extracellular application on development of avian cochleovestibular ganglion cells in vitro
Authors: Bilak Masako M. , Hossain Waheeda A. , Morest D. Kent
Published: February 2003

In an avian coculture system, the neuronal precursors of the cochleovestibular ganglion typically migrated from the otocyst and differentiated in response to soluble fibroblast growth factor (FGF‐2), which had free access to FGF receptors on the cell surface. Free FGF‐2 switched cells from a proliferation mode to migration, accompanied by increases in process outgrowth, fasciculation, and polysialic acid expression. Microsphere‐bound FGF‐2 had some of the same effects, but in addition it increased proliferation and decreased fasciculation and polysialic acid. As shown by immunohistochemistry, FGF‐2 that was bound to latex microspheres depleted the FGF surface receptor protein, which localized with the microspheres in the cytoplasm and nucleus. For microsphere‐bound FGF‐2, the surface receptor‐mediated responses to FGF‐2 appear to be limited and the door opened to another venue of intracellular events or an intracrine mechanism. © 2003 Wiley‐Liss, Inc.
Oxidative neuronal death caused by glutamate uptake inhibition in cultured hippocampal neurons
Authors: Himi Toshiyuki , Ikeda Masayuki , Yasuhara Tadashi , Murota Sei‐itsu
Published: February 2003

Glutamate transporters are coupled with cystine/glutamate antiporters to supply cystine as a component of glutathione, an important antioxidant. We sought evidence that L‐trans‐pyrrolidine‐2,4‐dicarboxylate (PDC) enhances glutamate‐induced neuronal damage not only via the N‐methyl‐D‐aspartate (NMDA) receptor mediated pathway, but also through induction of oxidative stress. Cultured hippocampal cells were exposed to glutamate (100 μM) for 5 min, washed and incubated for 18 hr with PDC (200 μM). PDC, increasing the neuronal death to 147% of that induced by glutamate alone, depleted glutathione in the culture, and produced dichloro‐dihydro‐fluorescein‐diacetate‐positive reactive oxygen species in neurons. N‐acetylcysteine (2 mM) not only reduced PDC‐enhanced neuronal death but also recovered glutathione and abolished the reactive oxygen species in these neurons. Threo‐β‐benzyloxyaspartate, another type of glutamate transporter inhibitor, also induced glutathione depletion in the glutamate‐preloaded cells, suggesting the involvement of glutamate transporter blocking in glutathione depletion. The NMDA receptor antagonist MK‐801, although partially effective in reducing PDC toxicity, slightly recovered glutathione level but did not reduce the reactive oxygen species even at a high concentration (100 μM). N‐acetylcysteine, dimethylsulfoxide, alpha‐phenyl‐N‐butyl nitrone and glutathione ethylester prevented neuronal death enhanced by PDC, but superoxide dismutase and catalase did not. Our study provides evidence that the block of glutamate uptake by PDC exerts toxicity on glutamate‐pretreated neurons not only through the accumulation of extracellular glutamate and subsequent activation of the NMDA receptor but also through depletion of glutathione and generation of reactive oxygen species. © 2002 Wiley‐Liss, Inc.