bluuebunny/crossref_metadata_2025_split huggingface dataset:
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. magnified image
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. magnified image
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. magnified image
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. magnified image
New low‐dimensional solids: Tellurium‐rich alkali metal tellurides
Authors: Sheldrick William S. , Wachhold Michael , Jobic Stephane , Brec Raymond , Canadell Enric 
Published: May 2005

AbstractThe 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

AbstractA 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

AbstractA 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

AbstractThis 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

AbstractThree 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

AbstractThe 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

AbstractA 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

AbstractKeratin 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

AbstractA 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

AbstractConditions 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

AbstractFirefly 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

AbstractThe 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

AbstractA 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

AbstractAcylated 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

AbstractRegulatory 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

AbstractAn 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

AbstractPeroxidases, 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

AbstractWe 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

AbstractA 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

AbstractATP 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.