bluuebunny/crossref_metadata_2025 huggingface dataset:
Cyclic changes in messenger RNAs encoding inhibin/activin subunits in the ovary of the golden hamster (Mesocricetus auratus)
Authors: Arai Koji Y , Kishi Hisashi , Onodera Satoshi , Jin Wanzhu , Watanabe Gen , Suzuki Akira K , Takahashi Shinji , Kamada Toshihiko , Nishiyama Toshio , Taya Kazuyoshi
Published: June 2005

To elucidate changing patterns of inhibin/activin subunit mRNAs in the ovary of the golden hamster (Mesocricetus auratus) during the oestrous cycle, inhibin/activin subunit cDNAs of this species were cloned and ribonuclease protection assay and in situ hybridization were carried out. Inhibin α-subunit mRNA was localized in granulosa cells of primary, secondary, tertiary and atretic follicles throughout the 4-day oestrous cycle. It was also expressed in luteal cells on days 1 (oestrus), 2 (metoestrus) and 3 (dioestrus). βA-subunit mRNA was localized in granulosa cells of large secondary (>200 μm) and tertiary follicles throughout the oestrous cycle. βB-subunit mRNA was confined to granulosa cells of large secondary and tertiary follicles. Both α- and βA-subunit mRNAs were also found in ovarian interstitial cells and theca interna cells of tertiary and atretic follicles in the evening of day 4 (pro-oestrus). A striking increase in βA-subunit mRNA levels was also observed during the preovulatory period. The expression pattern of βA-subunit mRNA during the preovulatory period is unique and not found in other species. An i.v. injection of anti-luteinizing hormone-releasing hormone (LHRH) serum before the LH surge abolished the expression of α- and βA-subunit mRNAs in ovarian interstitial cells and theca interna cells. The treatment also abolished the preovulatory increase in βA-subunit mRNA. Furthermore, administration of human chorionic gonadotrophin (hCG), which followed the injection of anti-LHRH serum, restored the expression patterns of α- and βA-subunit mRNAs. The present study revealed that the golden hamster showed a unique expression pattern of βA-subunit mRNA in response to the LH surge.
Plasma leptin and ghrelin in the neonatal rat: interaction of dexamethasone and hypoxia
Authors: Bruder Eric D , Jacobson Lauren , Raff Hershel
Published: June 2005

Ghrelin, leptin, and endogenous glucocorticoids play a role in appetite regulation, energy balance, and growth. The present study assessed the effects of dexamethasone (DEX) on these hormones, and on ACTH and pituitary proopiomelanocortin (POMC) and corticotropin-releasing hormone receptor-1 (CRHR1) mRNA expression, during a common metabolic stress – neonatal hypoxia. Newborn rats were raised in room air (21% O2) or under normobaric hypoxia (12% O2) from birth to postnatal day (PD) 7. DEX was administered on PD3 (0.5 mg/kg), PD4 (0.25 mg/kg), PD5 (0.125 mg/kg), and PD6 (0.05 mg/kg). Pups were studied on PD7 (24 h after the last dose of DEX). DEX significantly increased plasma leptin and ghrelin in normoxic pups, but only increased ghrelin in hypoxic pups. Hypoxia alone resulted in a small increase in plasma leptin. Plasma corticosterone and pituitary POMC mRNA expression were decreased 24 h following the last dose of DEX, whereas plasma ACTH and pituitary CRHR1 mRNA expression had already increased (normoxia and hypoxia). Hypoxia alone increased corticosterone, but had no effect on ACTH or pituitary POMC and CRHR1 mRNA expression. Neonatal DEX treatment, hypoxia, and the combination of both affect hormones involved in energy homeostasis. Pituitary function in the neonate was quickly restored following DEX-induced suppression of the hypothalamic–pituitary–adrenal axis. The changes in ghrelin, leptin, and corticosterone may be beneficial to the hypoxic neonate through the maintenance of appetite and shifts in intermediary metabolism.
Salivary glands as a potential gene transfer target for gene therapeutics of some monogenetic endocrine disorders
Authors: Voutetakis Antonis , Bossis Ioannis , Kok Marc R , Zhang Weitian , Wang Jianghua , Cotrim Ana P , Zheng Changyu , Chiorini John A , Nieman Lynnette K , Baum Bruce J
Published: June 2005

Salivary glands (SGs) exhibit several important features which are also common to endocrine glands: self-containment due to a surrounding capsule, highly efficient protein production and the ability to secrete proteins into the bloodstream. We have hypothesized that SGs are potentially useful as gene transfer targets for the correction of inherited monogenetic endocrine disorders. In the present communication, we extend our studies and attempt to test our hypothesis by comparing the efficacy of two commonly used viral vectors and the resulting serum and salivary distribution of transgene encoded hormones.

A low dose (5 ×109 particles) of either an adenoviral serotype 5 (Ad5) vector encoding the human erythropoietin (hEPO) cDNA or an adeno-associated virus sero-type 2 (AAV2) vector encoding either the hEPO or human growth hormone (hGH) cDNA was administered to individual submandibular SGs of Balb/c mice. Serum and salivary hEPO and hGH levels were determined at defined time points. Two additional recombinant viruses encoding enhanced green fluorescence protein (GFP) were also used (AdGFP and AAVGFP) in order to perform immunohistochemical analyses of transgenic protein localization in SG sections post-administration.

AAV2 vectors led to stable gene transfer unlike the results with the Ad5 vectors. Indeed, in one mouse we observed hEPO production for a period of two years after administration of AAVhEPO to SGs. hEPO, which is a constitutive pathway secretory protein, was readily secreted into the bloodstream from the SGs, yielding therapeutically adequate serum levels. Conversely, hGH, a regulated secretory pathway protein, was preferentially secreted into saliva.

SGs may be an attractive candidate target tissue for gene therapeutics of some monogenetic endocrine deficiency disorders. At present, AAV2 vectors seem particularly useful for such applications, and transgenes encoding constitutive secretory pathway hormones are more suitable for this application with SGs than those encoding regulated secretory pathway hormones.
Liquid crystals— new compounds, new applications
Authors: Eidenschink Rudolf
Published: May 2005

Low molecular weight liquid crystals have been used extensively in electrooptic displays. New non‐polymer thermotropic materials (see figure for an example) have now opened the way to further technical applications such as anisotropic reaction media, brake and clutch systems, laser optics and, ofcourse, more varied electrooptic devices.

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Is everything O. K. with solid‐state chemistry?
Authors: Boldyrev Vladimir
Published: May 2005

The deficiencies in the teaching and representation of solid‐state chemistry are two of the topics addressed including the classification of this branch of science within IUPAC. The options presented are based on the answers given to a questionnaire by some of the world's leading chemists and suggestions are made for improvement.
Electrochemical coupling of dialkylated sexithiophene
Authors: Delabouglise Didier , Hmyene Mohamed , Horowitz Gilles , Yassar Abderrahim , Garnier Francis
Published: May 2005

A fusible, soluble sexithiopphene is reeported and it is shown that this material can be electropolymerized to form thin polymeric layers which exhibit well‐defined redox behavior and high contrast electrochromism. This is an important step towards increasing the conjugation lenght in these materials, efforts which had previously been hampered by the insoluble nature of oligomers with six or more thiophene units.
The quest for magnetic polymers—caveat emptor
Authors: Miller Joel S.
Published: May 2005

Numerous reports claiming ferromagnetic behavior in organic polymers exist; however, the reported materials have been plagued by ill‐defined compositions, low yields on a magnetic basis, and poor reproducibility. Such low values of saturation magnetization (i.e., ≪ 5600 emuG/mol spin) cause serious concern as to whether the magnetic behavior arises from extrinsic sources and thus obligate the researcher to provide a persuasive case that when a material has a low saturation magnetization, suggesting thrtt the magnetic fraction is only a small portion of the bulk, that the magnetic behavior is in fact intrinsic and not of extrinsic origin. In several cases, when reinvestigated, the magnetic behavior of reported polymeric magnetic materials has been attributed to extrinsic sources. In the cases where extrinsic sources have not been identified, verification of the magnetic behavior has not been reported by independent laboratories. Thus, to date there have not been any reports of a bulk polymer that have stood the test of confirmation for ferromagnetic or even ferrimagnetic behaviour. Hence, caveat physics—scientist beware.
Molecular electronics on the virgin islands
Authors: Aviram Ari
Published: May 2005

Gregory Girolami of the University of Illinois reports on an ACS session on “Molecular Routes to Materials”, and Ari Aviram of the IBM Watson Research Center gives his impessions on the “Molecular Electronics–Science and Technology” conference held recently on the Virgin islands.
Laser floating zone growth of textured Ag/(Bi,Pb)SrCaCuO superconductors
Authors: de la Fuente German F. , Huang Yi‐Bing , Badia Antonio , Lera Francisco , Rillo Conrado , Navarro Rafael , Ibáñez Rafael , Beltrán Daniel
Published: May 2005

Superconducting composite wires and tapes based on textured Ag/(Bi,Pb)SrCaCuO materials can be produced using the laser floating zone technique. The method allows the production of pure (see figure) and Ag‐containing fibers from molten polycrystalline precursors and an investigations of the relationship between microstructure and properties of the fibers.

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Synthesis and characterization of new annelated terheterocycles
Authors: Bäuerle Peter , Götz Günther , Emerle Peter , Port Helmut
Published: May 2005

New annelated terheterocycles have been synthesized and their properties compared with those of the parent systems. The new compounds have mixed structural elements coming from benzo[c]heterocycles, which combine an o‐quinoidal π‐system. The preceding article in this issue, from Lorcy and Cava, describes similar but independent work.
A new class of self‐assembled monolayers: Organic thiols on gallium arsenide
Authors: Bain Colin D.
Published: May 2005

The spontaneous assembly of long chain thiols on the clean oxide‐free surface of gallium arsenide has recently been reported by a group at Penn State University. In the past, the substrates on which this was possible were restricted to the group 10 and 11 metals Au, Ag, Pt, and Cu, and the oxides of silicon, aluminum and silver. The work and its consequences for GaAs‐based microelectronics are discussed.
STM‐based nanotechnology: The japanese challenge
Authors: Grey François
Published: May 2005

Japan is launching an ambitious ten‐year nanotechnology project, the goal of which is the “ultimate manipulation of atoms and molecules”. An important aspect of this project is the use of the scanning tunneling microscope (STM) to modify materials on the nanometer scale. Another five‐year Japanese project devoted entirely to STM‐controlled atom‐scale fabrication is already nearing completion. Japanese industrial laboratories have also produced some outstanding results in this area of research. This article reviews recent Japanese efforts in STM‐based nanotechnology and attempts to put these in a worldwide perspective.
Functionalized langmuir–blodgett films—toward the construction of molecular devices
Authors: Tachibana Hiroaki , Matsumoto Mutsuyoshi
Published: May 2005

Control of the orientation of component molecules in Langmuir–Blodgett (LB) films is important for their use in molecular electronics. Cyclodextrins can be given a particular orientation at the air‐water interface by introducing long alkyl chains through the amino, sulfinyl, and sulfide groups (see Figure). This article reviews progress in molecular‐component and supramolecular LB films and photochemical switching systems constructed from them.

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Low power nonlinear optical response of C60 and C70 fullerene solutions
Authors: Henari Fryad Z. , MacNamara Shane , Stevenson Orla , Callaghan Joseph , Weldon Declan , Blau Werner J.
Published: May 2005

Solutions of C60 and C70 exhibit a large third‐order nonlinear response, even when investigated with low‐power visible lasers. The remarkably large nonlinearity observed is attributed to a combined effect of thermally induced nonlinear refractive index changes and simultaneous nonlinear absorption. Fullerenes have the potential for applications in all‐optical devices if they retain the same properties as in solution when dispersed in a transparent polymer matrix.
Synthesis, crystal structure, magnetic properties, and spin densities of a triazole‐nitronyl‐nitroxide radical
Authors: Pei Yu , Kahn Olivier , Aebersold Michael A. , Ouahab Lahcène , Le Berre Françoise , Pardi Luca , Tholence Jean Louis
Published: May 2005

A triazole‐nitronyl‐nitroxide radical (see Figure) combining a 1,2,4‐triazole function—which plays an important role in the field of spin transition compounds—and a nitronyl nitroxide radical— a magnetic building blick used in organic magnets — is reported. Its synthesis, crystyal structure, magnetic properties and spin densities are described.

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The tomographic atom probe: New dimensions in materials analysis
Authors: Deconoihout Bernard , Chambreland Sylvain , Blavette Didier
Published: May 2005

The tomographic atom prob (TAP) is the most advanced of the three‐dimemsional atom probes currently in use. Atom probes are unique in that both the lateral and the depth resolution are high. The genera; development of atom probes and the principle of operation ot the TAP, in which the sample is field evaporated atomic loayer by atomic layer, are outlined. The analysis of a nickel base superalloy is given as an example of an application in metallurgy.
High coordination number calamitic metallomesogens
Authors: Bruce Duncan W.
Published: May 2005

Metal‐containing liquid crystals are a rapidly expanding field. Approavhes to the design and synthesis of high coordination number complexes with liquid crystal properties, such as the mesomorphic ferrocenes in the for example orthometallated imines, are discussed.

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Nanoporous tin(IV) sulfides: Thermochemical properties
Authors: Jiang Tong , Ozin Geoffrey A. , Bedard Robert L.
Published: May 2005

The porosity, the integrity of the framework and any envisaged applications of sulfide‐based nanoporous layered materials produced using organic templates, depend upon the stability of the materials with respect to the thermally induced template removal process. Here, the thermochemical properties of two such materials are examined using a variety of techniques and conclusions drawn concerning the thermal stability range and the reconstructio processes which take place.
Uniform colloidal particles in solution: Formation mechanisms
Authors: Ocaña Manuel , Rodriguez‐Clemente Rafael , Serna Carlos J.
Published: May 2005

Monodisperse colloids have found a wide range of technolgoical applications, in fields as diverse as ceramics, pigments, and catalysis. Recent work in analyzing the mechanism of formation of the particles is reviewed, and the facotrs influencing the size and shape of the colloids, such as the SiO2 particles shown in the Figure, are discussed.

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Silver‐selective electrodes based on supported liquid membranes
Authors: Casabó Jaume , Teixidor Francesç , Escriche Luis , Viñas Clara , Pérez‐Jiménez Consuelo
Published: May 2005

Transport‐assisted membranes are materials that can perform specific chemical separation and chemical determination tasks. These membranes are conventional polymeric or ceramic membranes incorporating a carrier. The use of this technology in the development of ion‐selective electrodes using a variety of cyclic ethers and thioethers (e.g. see Figure) is reviewed.

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“Inverted” polymer light‐Emitting diodes on cylindrical metal substrates*
Authors: Westerweele Ed , Smith Paul , Heeger Alan J.
Published: May 2005

A cylindrical polymer‐based light‐emitting diode is reported. An aluminum rod is used simultaneously as a substrate and as the electron‐injecting electrode, and a soluble derivative of poly‐p‐phenylenevinylene, and polyaniline are used as the electroluminescent layer and the hole‐injecting electrode respectively. The materials are dip‐coated directly from solution simplifying the production process. It is thought that the optimization of the materials used in this novel structure will lead to performance enhancement.
Novel gold‐dithiol nano‐networks with non‐metallic electronic properties
Authors: Brust Mathias , Schiffrin David J. , Bethell Donald , Kiely Christopher J.
Published: May 2005

Stable nanostructured networks of quantum‐sized particles have been prepared “see Figure” using self‐assembly techniques. Here, two new techniques are reported for the preparation of non‐metallic composite materials comprising nanometersized gold particles self assembled into a 3‐D network by means of organic dithiols

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Template synthesis of graphitic nanotubules*
Authors: Parthasarathy Ranjani V. , Phani K. L. N. , Martin Charles R.
Published: May 2005

Ensembles of graphite‐based nanotubes (see Fig.) have been produced by extending a template approach successfully used for metals and semiconductors to carbons. The outer andinner diameters of the tubules can be controlled by varying the time allowed for the polymerization of acrylonitrile within the pores of a nanotubes formed in the pores are subsequently graphitized at high temperatures to form the graphitized nanotubes

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The influence of surface structure on the discotic liquid crystalline alignment. an infrared spectroscopy study
Authors: Perora Tunic S. , Vij Prof. Jagdish K.
Published: May 2005

The type of alignment achieved with discotic liquid crystals is important for a number of applications. It is found to depend decisively on the structure of the substrate. Infrared dichroism experiments are used to study the alignment of truxene and triphenylene cores (see Fig.) on amorphous silicon and polycrystalline ZnSe substrates, revealing considerable differences and hinting at the opportunity to tune the alignment of the materials

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Synthetic hollow aluminophosphate microspheres**
Authors: Oliver Scott , Ozin Geoffrey A. , Coombs Neil
Published: May 2005

Hollow aluminophosphate microspheres, based on mesolamellar surfactant bilayer aluminophosphate composite material, have been synthesized in polyethylene glycol by an alkylamine surfactant based method. The surface of the spheres displays patterns of surface impressions as well as fine morphological detail withi the spherical features.
The IRC in materials for high‐performance applications
Authors: Loretto Michael H.
Published: May 2005

The Interdisciplinary Research Centre based in Birmingham and Swansea concentrates on the study and development of high‐performance materials. The Director of the IRC presents the structure, funding, and aims of the Centre and discusses the relevance of the work carried out with Government and contract funding for industry and academia.
Scanning tunneling microscopy analysis of epitaxially crystallized IV‐VI semiconductor surfaces and pn‐junctions of IV‐VI heterostructures
Authors: Stocker Wolfgang , Böttner Harald , Tacke Maurus , Cantow Hans‐Joachim
Published: May 2005

The characteristics of pn semiconductor junctions and the epitaxial layers at the interface are of great interest for the optimization of heterostructure device performance. Here, an STM study of narrow gap lead chalcogenide heterostructures is presented, providing insight into the influence of chemisorption of, for example, oxygen on the structure of the interface.
On the quinoid structure of poly(isothianaphthene): A vibrational spectroscopic study
Authors: Zerbi Giuseppe , Magnoni Maria Chiara , Hoogmartens Ivan , Kiebooms Raphael , Carleer Robert , Vanderzande Dirk , Gelan Jan
Published: May 2005

The low band gap polyconjugated aromatic material PITN (see figure, left) is shown, on the basis of te results of Raman spectroscopy, to in fact have the quinoid structure in its electronic ground state. This is the first demonstration that these technologically interesting materials adopt the quinoid structure

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Synthesis, crystal structure, and magnetic properties of 5‐methyl‐l,2,4‐triazole‐nitronyl nitroxide: A one‐dimensional compound with unusually large ferromagnetic intermolecular interactions
Authors: Kahn Olivier , Lang Andreas , Pei Yu , Ouahab Lahcène
Published: May 2005

Triazole nitronyl nitroxide radicals and their derivatives are open‐shell molecules with potential applications as building blocks for the synthesis of multi‐property molecular materials. The title compound (see figure) exhibits exceptionally strong ferromagnetic interactions. Its synthesis, crystallographic data and magnetic properties are described. Possible mechanisms for the origin of these properties are suggested.

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Mesomorphic behavior of new double swallow‐tailed compounds
Authors: Weissflog Wolfgang , Letko Iris , Diele Siegmar , Pelzl Gerhard
Published: May 2005

Double swallow‐tailed compounds are special cases of tetracatenar mesogens (mesogens consisting of a rod‐like core and two half‐disc shaped moieties), where the branches are not attached directly to the terminal rings. Experiments are reported in which the middle part of the core and the length of the terminal chains were varied. The resulting effects on the transition temperatures and phase behavior are described and trends pointed out.
Amperometric biosensors produced by immobilization of redox enzymes at polythiophene‐modified electrode surfaces
Authors: Hiller Markus , Kranz Christine , Huber Johanna , Bäuerle Peter , Schuhmann Wolfgang
Published: May 2005

The use of polythiophene films for the immobilization of enzymes at electrodes is shown to have advantages over other conducting polymer films. Two methods by which the enzymes can be immobilized—entrapment and covalent immobilization at the surface—are described and compared. The improved stability of polythiophene against oxidation in ambient environments is expected to enable the construction of biosensors with improved sensor characteristics and lifetime.
Dental implant materials: Surface modification and interface phenomena
Authors: Rupp Frank , Geis‐Gerstorfer Jürgen , Geckeler Kurt E.
Published: May 2005

Interactions of biomaterials with hard and soft tissue, blood, or saliva are primarily controlled by the surface properties of the materials. Titanium and its alloys, in particular, have been shown to be biocompatible for many orthopedic and dental implant applications, but the surfaces of the metal still need modification in order to achieve bioactive or bioinert performance. Current methods and future trends in surface treatment of dental implant materials are presented and phenomena the implant‐bioenvironment interface highlighted.
Cooperative proton‐electron transfer in a supramolecular structure of meso‐1,2‐bis‐(4‐dimethylaminophenyl)‐1,2‐ethanediol and bis(4‐cyanobenzylidene)ethylenediamine
Authors: Felderhoff Michael , Steller Ingo , Reyes‐Arellano Alicia , Boese Roland , Sustmann Reiner
Published: May 2005

A supramolecular 1:1 complex of the title compounds undergoes light‐induced cooperative proton‐electron transfer which can be switched back by warming to 60°C. The complex (see Figure) is found to exhibit a unique from the photochromism, meaning that it could have potential in optical switching (with termal back switching) or optical data storage applications.

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The optical behavior of lyotropic liquid crystalline polymer gel networks: Dependence on temperature
Authors: Seeboth Arno , Holzbauer Hans‐Rainer
Published: May 2005

Gel networks with interesting optical properties have been prepared on the basis of a highly ordered aqueous polymer lyotropic liquid crystalline phase, embedded in a thermally stable polymer network. The optical transparency changes reversibly with an increasing or decreasing temperature of a few degrees up to a contrast ratio of 85:1. Different lyotropic phases exist in close proximity in the system, for example a schlieren texture (see Figure) and a radial droplet structure.

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Formation of columnar mesophases by rod‐like molecules: Facial amphiphilic p‐Terphenyl derivatives
Authors: Tschierske Carsten , Hildebrandt Frank , Schröter Jörg A. , Wendorff Joachim H. , Festag Reinhard , Wittenberg Michael
Published: May 2005

The liquid‐crystalline behavior of rod‐like mesogens is normally associated with the formation of smectic layer structures. However, it is shown that the introduction of large hydrophilic groups in a lateral position, such as in the Figure, can lead to columnar mesophases. The formation of columnar mesophases by rod‐like molecules is suggested to be a more general phenomenon than currently thought.

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Photoinduced switching in nanocomposites of azobenzene and molecular sieves
Authors: Marlow Frank , Hoffmann Katrin , Caro Jürgen
Published: May 2005

A model system for the photoinduced rearrangement of adsorbates in molecular sieves—composites that hold promise as materials with new electronic and optical properties—is the photoinduced cis–trans isomerization of azobenzene (Az) in the zeolites AIPO4‐5, ZSM‐5, and silicalite −1. A spectroscopic investigation presented demonstrates that reversible intrazeolite isomerization of Az causes large changes in the optical properties of the composites, e.g., in absorbance and birefringence, making the materials of interest for optical switching.
Polyazulenes and Polybiazulenes: Chiroptical Switching and Electron Transfer Properties of Structurally Segmented Systems
Authors: Porsch Michael , Sigl‐Seifert Gabriele , Daub Jörg
Published: May 2005

The characterization of polyazulenes is reported with regard to two main aspects. First, results of circular dichroism spectroelectrochemistry of a carbohydrate‐modified azulene indicate that structural reorganization and chiroptical switching occur on oxidative doping. Second, the investigation of phenylene/azulene polymeric films with meta‐ or para‐phenylenes as bridging units provides information about electron transport and shows that phenylenic bridging allows structurally separated electron‐transfer‐active subunits to be created within the polymeric chain.
New low‐dimensional solids: Tellurium‐rich alkali metal tellurides
Authors: Sheldrick William S. , Wachhold Michael , Jobic Stephane , Brec Raymond , Canadell Enric
Published: May 2005

The crystal and electronic structure of several recently reported tellurium‐rich alkali metal tellurides is discussed. Some of these materials contain defective square planar tellurium lattices, which on the basis of band structure calculations are expected to be new low‐dimensional metals. The structural interrelations between some of these new phases can be understood once the primordial template role of the alkali metal as well as the secondary Te…Te interactions are considered. Tellurium‐rich alkali metal tellurides seem to be promising materials in the search for new solids with interesting structural and electronic properties.
Modeling of the PGSS process by crystallization and atomization
Authors: Li Jun , Rodrigues Miguel , Paiva Alexandre , Matos Henrique A. , Gomes de Azevedo Edmundo
Published: May 2005

A particles from gas‐saturated solution (PGSS) process for the model system hydrogenated palm oil (HPO) with CO2 was implemented and particle information, including size, size distribution, and morphology, is reported. The PGSS process in a capillary nozzle is modeled to be in steady, one‐dimensional, inviscid, and two‐phase (CO2‐rich phase and liquid HPO/CO2 phase) annular‐mist flow. The Peng–Robinson equation of state is applied for the nonideality of the binary CO2/HPO and the fluid hydrodynamic equations of two phases are established to describe the system's pressure, temperature, velocity, and density along the nozzle. The aerosol dynamic equation for the crystallization of HPO in the CO2‐rich phase is used to explain the HPO crystal formation and growth under supercooling and supersaturation. For the liquid HPO/CO2 phase, the atomization mechanism in terms of the interaction of the two phases gives HPO droplet information. The coupled model equations are numerically solved to obtain the HPO particle size and particle size distribution at the nozzle exit under several operating conditions. Different distribution modes are found, in agreement with the experimentally obtained particle spectra, an indication of the soundness of the model's particle formation mechanisms. Particles produced by atomization usually prevail over those formed from crystallization; yet, there exist special operating conditions under which the rapid expansion of supercritical solution (RESS) mechanism cannot be neglected and melt crystallization may be significant. The comparison between theoretical and experimental particle morphologies indicates that atomization may produce mainly spherical but relatively large particles; melt crystallization provides amorphous crystal particles, and the RESS process gives small and irregular crystals. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Morphology, mechanical and viscoelastic properties of nitrile rubber/epoxidized natural rubber blends
Authors: Mathai Asha Elizabeth , Thomas Sabu
Published: May 2005

A new class of blend membranes from blends of nitrile rubber (NBR) and epoxidized natural rubber (ENR) has been prepared and their morphology, miscibility, mechanical, and viscoelastic properties have been studied. The ebonite method was used to study the blend morphology of the membranes. The morphology of the blends indicated a two‐phase structure in which the minor phase is dispersed as domains in the major continuous phase. The performance of NBR/ENR blend membranes has been studied from the mechanical measurements. The viscoelastic behavior of the blends has been analyzed from the dynamic mechanical data. An attempt was made to relate the viscoelastic behavior with the morphology of the blends. Various composite models have been used to predict the experimental viscoelastic data. The area under the linear loss modulus curve was larger than that obtained by theoretical group contribution analysis. The homogeneity of the system was further evaluated by Cole–Cole analysis. Finally, a master curve for the modulus of the blend was generated by applying the time–temperature superposition principle. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1561–1573, 2005
Synthesis and modification of epoxy‐ and hydroxy‐functional microspheres
Authors: Falk Benjamin , Crivello James V.
Published: May 2005

This article describes the synthesis and surface modification of epoxy‐ and hydroxy‐functional polymeric microspheres. The functionalized microspheres were synthesized using aqueous and nonaqueous cationic suspension photopolymerizations using multifunctional silicon‐containing epoxy monomers with iodonium salt photoinitiators. Although generally solid microspheres were obtained using these techniques, macroporous spheres could be obtained though the use of porogens. Various rapid and facile acid‐ and base‐catalyzed ring‐opening addition reactions were performed on the epoxy‐functional microspheres. These reactions include the additions of mercaptans, acid chlorides, isocyanates, amines, sodium azide, water, and alcohols. Similar functionalization reactions were performed on the hydroxy‐functional microspheres. The particle size and size distribution were determined using scanning electron microscopy. Fourier transform infrared spectroscopy was used to monitor the functionalization reactions. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1574–1585, 2005
Boric acid recovery using polymer filtration: Studies with alkyl monool, diol, and triol containing polyethylenimines
Authors: Smith Barbara F. , Robison Thomas W. , Carlson Bryan J. , Labouriau Andrea , Khalsa Guru Rattan K. , Schroeder Norman C. , Jarvinen Gordon D. , Lubeck Christopher R. , Folkert Susan L. , Aguino Dominic I.
Published: May 2005

Three water‐soluble polymers containing linear alkyl monool, 1,2‐diol, and 1,2,3‐triol groups, mostly on the primary amines of polyethylenimine, were synthesized, characterized, and tested for their ability to recover boric acid. The boron‐binding capacities of these polymers and the backbone polyethylenimine were determined by titration, ultrafiltration, and inductively coupled plasma/atomic emission spectroscopy analysis. At low boron concentrations, the 1,2,3‐triol polymer performed better than the 1,2‐diol, whereas at high boron concentrations, the 1,2‐diol outperformed the 1,2,3‐triol. 11B‐NMR spectroscopy and retention studies with various salt concentrations indicated that boron interacted with these two polymers by means of ion pairing with the protonated amines and by borate ester formation. For the monool and the polyethylenimine backbone, the mechanism for boron binding was ion pairing only. These polymers are under consideration for the selective recovery and recycling of enriched boric acid used in the primary coolant loop of pressurized water nuclear reactors. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1590–1604, 2005
Moisture sorption/desorption behavior of various manmade cellulosic fibers
Authors: Okubayashi Satoko , Griesser Ulrich J. , Bechtold Thomas
Published: May 2005

The kinetics of dynamic water vapor sorption and desorption on viscose, modal, cotton, wool, down, and polyester fibers and lyocell knit fabrics were investigated according to the parallel exponential kinetics (PEK) model. The total equilibrium moisture regain (Minf(total)) in all the materials decreased with increasing temperature. However, the partial equilibrium fast sorption, determined by PEK simulation at 60% relative humidity (RH) and 36°C, was larger than that at 20°C, whereas the partial equilibrium slow sorption was smaller. The characteristic times in fast sorption (τ1) and in slow sorption (τ2) for lyocell were reduced when the conditions were changed from 60% RH and 20°C to 36°C, whereas those for the other fibers increased. Lyocell exhibited the highest Minf(total) value and the lowest τ1 and τ2 values, and this suggested high equilibrium moisture content and fast moisture uptake/release, that is, high moisture accessibility for lyocell. The relationships between the moisture regain, hysteresis, water retention capacity, and Brunauer–Emmett–Teller surface volume in the materials were also examined. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1621–1625, 2005
Study on ethylene (co)polymerization and its kinetics catalyzed by a reversible crosslinked polystyrene‐supported metallocene catalyst
Authors: Wang Wenqin , Wang Li , Wang Jianfeng , Ma Zhenli , Wang Jianjun
Published: May 2005

A well‐defined linear polystyrene with cyclopentadienes groups was prepared and characterized. The cyclopentadienes groups performed a Diels–Alder reaction to form the reversible crosslinking of the support. In olefin polymerization the crosslinked active species transformed noncrosslinked active species via MAO. The influence of the reversibility of network on olefin polymerization was investigated. The polystyrene‐supported metallocene catalyst showed high activity and stable polymerization process in olefin polymerization. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1632–1636, 2005
Thermally processed keratin films
Authors: Barone Justin R. , Schmidt Walter F. , Liebner Christina F. E.
Published: May 2005

Keratin obtained from poultry feathers was modified with glycerol, which acted as a plasticizer. Films were prepared by pressing the modified keratin at temperatures concurrent with typical polymer processing temperatures. The films were completely cohesive as opposed to partially cohesive if pressed under the same conditions without glycerol. The films were “tough” and the mechanical properties show similarities to the properties of commercially available commodity thermoplastics. The keratin films were produced in a few minutes without reducing or oxidizing agents. The keratin films could have potential applications for which environmentally friendly materials are needed, such as food packaging or mulching films. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1644–1651, 2005
A portable silicon photodiode luminometer
Authors: Marks K. , Killeen P. , Goundry J. , Gibbons J. , Bunce R.
Published: May 2005

A simple, inexpensive, battery‐powered, portable luminometer which is based on a silicon photodiode is described. The instrument is intended to measure the light produced by chemiluminescent and bioluminescent reactions. The devic shows a good detection limit and, in a bioluminescent reaction for adenosine 5′‐triphosphate (ATP), detected 0.5 pmol in 1ml of aqueous solution. The instrument measures irradiance from 10−13 to 10−11 W cm−2 at the sensor, within the range 300 to 900nm.
Sensitivity limitations encountered in enhanced horseradish peroxidase catalysed chemiluminescence
Authors: Motsenbocker M. A.
Published: May 2005

Conditions for the enhanced horseradish peroxidase (HRP) catalysed reaction between luminol and hydrogen peroxide were optimized to determine detection limits for HRP conjugated to antibody fragment (HRP‐Fab) in solution phase. Light output was linear with respect to HRP‐Fab concentration but became nonlinear at low HRP‐Fab concentrations when an accelerator (enhancer) of the reaction was used. para‐Phenylphenol was a more effective enhancer than p‐iodophenol at HRP‐Fab concentrations below 20 pmol/l. The detection limit for HRP‐Fab was 1.2 femtomoles in the absence of p‐phenylphenol and 0.08 femtomole in the presence of p‐phenylphenol. The acceleration of peroxidase activity at the lowest HRP‐Fab concentrations occurred after an incubation time period of up to five minutes. This lag time limited the sensitivity and the mechanism for it was sought. Preincubation experiment results indicated that the lag time phenomenon may involve a reversible alteration in HRP catalytic activity and that enhancer, peroxide, luminol and HRP‐Fab had to be incubated together some time before maximum activation could occur.
Continuous‐flow bioluminescent dtermination of ATP in platelets using firefly luciferase immobilized on epoxy methacrylate
Authors: Carrea Giacomo , Bovara Roberto , Girotti Stefano , Ferri Elida , Ghini Severino , Roda Aldo
Published: May 2005

Firefly luciferase was immobilized on epoxy methacrylate beads and used for a continuous‐flow assay of ATP extracted from platelets. The immobilized luciferase had a half‐life of 3 days at 25°C; there was a 25% recovery of luciferase activity upon immobilization, and ca 50 reactors were made from 1 mg of commercial enzyme. The sensitivity of the assay was 0.3 pmol of ATP, and the response was linear between 1 and 500 pmol of ATP. The content of platelets obtained with the present method correlated well with those obtained using soluble luciferase.
Pholasin chemiluminescence detects mostly superoxide anion released from activated human neutrophils
Authors: Müller T. , Davies E. V. , Campbell A. K.
Published: May 2005

The bioluminescent oxygen metabolite indicator protein pholasin was characterized with respect to the type and location of reactive oxygen metabolites detected in suspensions of stimulated human neutrophils. Whereas pholasin detected reactive oxygen metabolites from neutrophil suspensions stimulated with soluble agents, particulate stimulants were apparently not effective triggering agents for pholasin‐dependent neutrophil chemiluminescence. Neutrophils stimulated with fMet‐Leu‐Phe (1 to 100 nmol/l) showed maximum pholasin‐dependent chemiluminescence 45 to 60s after stimulation. The time of maximum chemiluminescence was virtually independent of fMet‐Leu‐Phe concentration. In contrast, the time to reach maximum light emission increased from 60s with 100 nmol/l phorbol ester to 295s with 1 nmol/l phorbol ester. Significant inhibition of stimulated chemiluminescence was caused by both superoxide dismutase (20 μg/ml, 80% inhibition) and reduction of the oxygen concentration in the incubation medium to less than 0.5 μmol/l (95% inhibition). In contrast, the myeloperoxidase inhibitor sodium azide (0.1 nmol/l) afforded only 50% inhibition of the pholasin‐dependent neutrophil chemiluminescence. Our results show that pholasin detects superoxide radicals released from cells stimulated by soluble stimulants but not intracellular oxidative activity elicited by particulate stimulants.
Determination of oil oxidation by an aldehyde‐requiring mutant of luminous bacteria
Authors: Berkovich A , Cogan U. , Ulitzur S.
Published: May 2005

A simple, rapid bioluminescence test (BT) for the determination of lipid oxidation is described. The test utilizes an aldehyde‐requiring dark mutant of Vibrio harveyi (M42) that emits light in the presence of long chain (C8‐C16) aliphatic aldehydes. The procedure consists of treating the oil or fat with Co2+ ion in ethanolic medium at alkaline pH. This treatment facilitates the decomposition of the hydroperoxides into long‐chain aldehydes, part of which is used by the bacteria to produce light. The test was evaluated with corn, soybean and safflower oils, and shows excellent correlation with the commonly used peroxide value assay.
Alkali‐labile luminol derivatives as labels for quantitative binding studies with polyionic macromolecules
Authors: Richards S. J. , Wusteman F. S.
Published: May 2005

Acylated derivatives of luminol (5‐amino‐2,3‐dihydro‐1,4‐phthalazinedione) bearing a carboxyl or amino group can be linked by amide bonds to a macromolecule requiring labelling. Though themselves of low quantum yield these compounds are alkali‐labile and can be detected at a similar level of sensitivity to the parent compound luminol. These cheap, readily accessible compounds are less hydrophobic than other currently employed chemiluminescent labels. They also lack a positively charged nitrogen atom which could complicate their covalent linkage to polyanionic compounds. They thus appear well suited for labelling heparin and other macromolecules which interact with the luminal surface of blood vessels.
Regulatory mutants of the Vibrio harveyi lux system
Authors: Cao J. G. , Swartzman E. , Miyamoto C. , Meighen E.
Published: May 2005

Regulatory mutants of the luminescent bacterium, Vibrio harveyi, have been isolated whose light emission can be stimulated by extracts of the growth media. Chloroform extracts of conditioned media in which V. harveyi has been grown can increase light emission in one of the dark mutants, D34, over 103‐fold. An increase in the level of the mRNA and the enzymes associated with the lux system can also be demonstrated.

Analysis of the expression of the lux system in Escherichia coli transformed with DNA from the D34 regulatory mutant demonstrates that the mutation resides outside the luciferase structural genes. The results suggest that the decrease in light emission in the regulatory mutants may be due to a mutation in synthesis of an autoinducer analogous to that found for the Vibrio fischeri lux system.
Development and evaluation of luminescence‐based sandwich assay for plasma lactoferrin as a marker for sepsis and bacterial infections in paediatric medicine
Authors: Maacks Susanne , Yuan Hui‐Zhen , Wood William Graham
Published: May 2005

An immunoluminometric assay for plasma lactoferrin has been developed and used to study the levels in children and neonates with viral and bacterial infections. The reference range for plasma lactoferrin was 50–250 μg/l. Lactoferrin levels were significantly higher in patients with bacterial versus viral infections.
Generation of triplet carbonyl compounds during peroxidase catalysed reactions
Authors: Cilento Giuseppe
Published: May 2005

Peroxidases, acting as oxidase upon appropriate substrates, generate carbonyl compounds in the electronically excited triplet state. These excited species can transfer energy as demonstrated by the appearance of the acceptor fluorescence or induced photochemistry concomitant with the disappearance of phosphorescence. Cholorophyll, an efficient emissive acceptor, either naturally present or artificially incorporated into organelles and cells, allows the in situ detection of biologically generated excited species.

With neutrophils, the myeloperoxidase promoted acetone phosphorescence can readily be detected. In other cases, e.g. triplet benzaldehyde, it is possible to observe emission from lipid peroxidation initiated by the triplet carbonyl compound.
Characterization of a chimeric aequorin molecule expressed in myeloma cells
Authors: Casadei Jan , Powell Michael J. , Kenten John H.
Published: May 2005

We have constructed a chimeric aequorin consisting of a fragment of the anti‐NP immunoglobulin gene fused to the aequorin gene. Expression in a myeloma cell line has produced a Fab′‐like molecule that has the ability to bind NIP specifically and generate bioluminescent activity. It takes approximately 8 h at 4 °C in the presence of 2‐mercaptoethanol and coelenterazine to regenerate luminescent activity. While the flash kinetics of this recombinant molecule are similar to native aequorin, its quantum efficiency is ten times lower. Preliminary studies have been conducted to ascertain its usefulness for immunoassays. We have shown for this chimeric aequorin 7 × 10−19 moles can be detected in solution, also it can be used in a solid‐phase assay and is stably stored at −70°C for at least 2 months.
New, sensitive, radioactive‐free bioluminescence‐enhanced detection system in protein blotting and nucleic acid hybridization
Authors: Hauber Regina , Miska Werner , Schleinkofer Ludwig , Geiger Reinhard
Published: May 2005

A relatively simple, very sensitive bioluminescence‐enhanced detection system for protein blotting and nucleic acid hybridization is described. The method utilizes antibodies conjugated with alkaline phosphatase or nucleotide probes complexed with alkaline phosphatase. Then the alkaline phosphatase takes part in a reaction by releasing D‐luciferin (Photinus pyralis) from D‐luciferin‐O‐phosphate. Liberated D‐luciferin reacts with luciferase, ATP and oxygen under light emission. Light is measured using the Argus‐100 a photon counting camera system or photographic films. Bound alkaline phosphatase conjugated antibodies or hybridized nucleotide probes can be visualized. The limit of detection is at present 5 to 50 fg of protein (IgG), corresponding, for example to 30 to 300 × 10−21 mol. This means a much higher sensitivity of the detection system in comparison to systems used at present. Experiments concerning nucleic acid hybridization and visualization of the emitted light by a photon counting camera (Argus‐100) are under investigation.
Improved ATP methodology for biomass assays
Authors: Schram Eric , van Witzenburg Anne Weyens
Published: May 2005

ATP methodology needs to be further standardized and improved in order to avoid the pitfalls that have sometimes hampered its application to biomass assays. The following steps have been reconsidered as far as the bacteriological applications is concerned:

destruction of free and somatic ATP: replacement of apyrase by mammalian ATPase, more readily accessible to specific inhibition;

extraction of bacterial ATP: protection of luciferase by lipids against inhibitory effect of cationic detergents with production of a constant light response.

New methods are proposed for the calibration of luminometers and for the matching of sample holders in multichannel instruments.

The limit of sensitivity of ATP assays is discussed in the light of currently available reagents and instruments.