bluuebunny/crossref_metadata_2025_split huggingface dataset:
Organic transistors using α‐octithiophene and α, ω‐dihexyl‐α‐octithiophene: Influence of oligomer length versus molecular ordering on mobility
Authors: Hajlaoui Riadh , Fichou Denis , Horowitz Gilles , Nessakh Belkacem , Constant Mathieu , Garnier Francis 
Published: May 2005

The efficiency of organic field‐effect transistors (OFETs) based on high‐purity α‐octithiophene (α‐8T) and its alkylated derivative DHα‐8T (see Figure) has been investigated, particular attention being paid to the influence of oligomer length, material purity, and film ordering on OFET performance, especially field effect mobility. The question of whether the mobility of the oligothiophenes keeps on increasing with chain length is discussed. magnified image
Direct observation of chemical reactions in silica‐coated gold and silver nanoparticles
Authors: Mulvaney Paul , Giersig Michael , Ung Thearith , Liz‐Marzán Luis M. 
Published: May 2005

The direct observation of chemical reactions of single particles in real time has been achieved using silver nano‐particles covered in a 10 nm silica shell (see cover). Transmission electron micrographs reveal how molecular iodine diffuses through the shell and reacts with Ag, giving AgI. A single AgI particle (mid‐gray) is shown to form on the surface of the silica while the Ag core shrinks. magnified image
Aromatic Poly(1, 3, 4‐Oxadiazoe)s as Advanced materials
Authors: Schulz Burkhard , Bruma Maria , Brehmer Ludwig 
Published: May 2005

The specialized‐performance polymers poly(arylene‐1,3‐oxadiazole)s—see Figure for an example—have high‐value end uses based on their electronic, optical, and thermal properties. The syntheses, solid‐state structure, properties, and applications of poly(arylene‐1,3,4‐oxadiazole)s are reviewed. magnified image
Multiplexing optical systems: Multicolor‐bifluorescent‐biredox photochromic mixtures
Authors: Tsivgoulis Gerasimos M. , Lehn Jean‐Marie 
Published: May 2005

Optical memory systems that exhibit multiplexity and multifunctionality may allow high‐density storage and multiple addressing and readout. In a first step towards such systems, it is shown that two‐component mixtures of dithienylethene compounds (e.g., see Figure) can be switched reversibly between four different color states, using light as a trigger. The fluorescence of redox behavior increases the multiplexity (see front cover). magnified image
Structures and properties of MeDTDM salts
Authors: Misaki Yohji , Taniguchi Masateru , Miura Takeshi , Fujiwara Hideki , Yamabe Tokio , Kawamoto Tadashi , Mori Takehiko 
Published: May 2005

Unsymmetric tetrathifulvalene (TTF) derivatives, especially when fused with 1,3‐dithiol‐2‐ylidenes (DT‐TTFs), have yielded a large number of metallic salts and even some superconductors. The synthesis and characterization of teh methyl‐substituted DT‐TTF MeDTDM (see Figure) are reported as part of the search for new superconductors, the conductivities and X‐ray structure analysis of the new metallic salts being emphasized. magnified image
Oligophenylenevinylenes for light‐emitting diodes
Authors: Goodson Theodore , Li Wenjie , Gharavi Ali , Yu Luping 
Published: May 2005

Details of the structure–property correlation in organic light‐emitting diodes (LEDs) are reported for the oligophenylenevinylene (OPV) system. The electroluminescence (EL) characteristics of 6‐OPV (n equals; 2 in the Figure) and 10‐OPV (n equals; 4 in the Figure) are compared and an explanation is proposed for the shift and broadening of the EL spectra under different driving voltages. magnified image
Magnetic field induced reversed (Negative) magnetization for electrochemically deposited Tc = 260 K Oxidized Films of Chromium Cyanide Magnets
Authors: Buschmann Wayne E. , Paulson Scott C. , Wynn Charles M. , Girtu Mihai A. , Epstein Arthur J. , White Henry S. , Miller Joel S. 
Published: May 2005

Molecule‐based magnets with high ordering temperatures Tc (above room temperature) include some mixed‐oxide hexacyanometallates. The example studied here, Cr2.12(CN)6 · ½ H2O (the Figure shows its crystalline and amorphous phases), is shown to have Tc equals; 260 K and exhibit negative (reverse) magnetization. An explanation is suggested for this behavior and the temperature and field dependences of the magnetization. magnified image
Solvent‐assisted microcontact molding: A convenient method for fabricating three‐dimensional structures on surfaces of polymers
Authors: King Enoch , Xia Younan , Zhao Xiao‐Mei , Whitesides George M. 
Published: May 2005

Solvent‐assisted micro‐contact molding (SAMIM), a non‐photo‐lithographic technique for fabriation of patterned, quasi‐three‐dimensional structures on surfaces of many different polymers, is described. The basis of the technique–an embossing/molding process in which a solvent softens a polymer–is out lined and many examples are given. The Figure shows a polystyrene structure produced using SAMIM with acetone as the solvent. magnified image
Molecular Recognition of Organized Assemblies via hydrogen bonding in aqueous media
Authors: Paleos Constantinos M. , Tsiourvas Dimitris 
Published: May 2005

Molecular recognition of non‐biological systems in aqueous media presents problems arising from the inherent difficulty of formation of host‐guest systems. Examples are given for recognition occurring at the air‐water interface—the most common type, where receptors from a monolayer at the interface (see Figure)—or in micelles or vesicles. The particular role of directional hydrogen‐bonding interactions is emphasized.magnified image
A novel family of amorphous molecular materials containing an oligothiophene moiety as color‐tunable emitting materials for organic electroluminescent devices
Authors: Noda Tetsuya , Ogawa Hiromitsu , Noma Naoki , Shirota Yasuhiko 
Published: May 2005

The color of light emitted by organic electroluminescent devices can be tuned between light blue and orange in the family of materials presented here simply by varying the conjugation length (n = 1 to 4, see Figure) of the oligothiophene moiety. The synthesis of the amorphous molecular materials and the optical behavior of single‐layer electroluminescent devices based on them—see also the cover—are described.magnified image
Bioluminescent assay of D‐3‐hydroxybutyrate in serum
Authors: Raunio Raimo P. , Leivo Pekka V. , Kuusinen Anne M. 
Published: May 2005

AbstractAn enzymatic assay of D‐3‐hydroxybutyrate in which the hydroxybutyrate dehydrogenase reaction is coupled to the bacterial oxidoreductase—uciferase system is described. The bioluminescent assay is based on either, end‐point, or on initial velocity measurements. This simple and rapid assay requires a single serum sample of 10 μl. Its linear range covers two orders of magnitude from 10−6 mol/I upwards. This assay is suitable for the routine determination of D‐3‐hydroxybutyrate in human blood with good accuracy.
Factors affecting the measurement of chemiluminescence in stimulated human polymorphonuclear leucocytes
Authors: Harber Michael J. , Topley Nicholas 
Published: May 2005

AbstractOptimum conditions were established for the generation and measurement of luminoldependent chemiluminescence (CL) in human polymorphonuclear leucocytes (PMNL) stimulated with a variety of particulate and soluble agents. Several factors had a particular influence on the kinetics of CL stimulated by the chemotactic peptide N‐formyl‐L‐methionyl‐L‐leucyl‐L‐phenylalanine (fMLP). Two peaks, both azide‐sensitive, were observed at 21°C and 25°C. but these increased in magnitude and merged t o give a single, early peak when the temperature was increased t o 37°C. Pre‐exposure of PMNL to a buffer containing calcium was essential for the expression of both phases of fMLP‐stimulated CL, while the second peak decreased dramatically if the cells were stored at 4°C for 4 hours before assay. In contrast, storage of PMNL at 4°C for up t o 8 hours in a buffer without divalent cations did not alter the kinetics or magnitude of CL induced by other stimuli, and had the benefit of minimizing the rate of cell aggregation. This study confirms that measurement of luminol‐dependent CL in stimulated PMNL is a useful analytical tool, but shows that careful attention t o experimental design is required t o ensure that the observed CL provides a true measure of the parameter under investigation.
A rapid enhanced chemiluminescent immunoassay for allergen‐specific IgE antibodies
Authors: Stiles Heather J. , Bicknell Helen J. , Matthews Jayne A. 
Published: May 2005

AbstractAn enhanced chemiluminescent immunoassay is described for the measurement of allergen‐specific IgE antibodies. The assay is demonstrated for pollen from four grass species. A comparison was made between results obtained by this method and those obtained by the radioallergosorbent (RAST) procedure; a high degree of correlation (r = 0.95) was found for D. glomerata specific IgE. The assay is rapid and can be carried out in under 1 hour. The advantages of the luminescent assay as compared with the RAST procedure are discussed.
Lampteromyces bioluminescence—1. Identification of riboflavin as the light emitter in the mushroom L. japonicus
Authors: Isobe Minoru , Uyakul Duangchan , Goto Toshio 
Published: May 2005

AbstractThe bioluminescence of the luminous mushroom, Lampteromyces japonicus, was studied by using the mushroom gills and also the luminous mycelia, the latter being cultured from the isolated spores and grown in a potato sucrose medium. The luminescence intensity of the mushroom gills and the cultured mycelia was measured in an aqueous suspension under various conditions. The original intensity was enhanced by exposing the luminous cells to oxygen for several hours or to acids or bases for a short period. This enhancement enabled measurement of their bioluminescence spectra which were identical to the fluorescence spectrum of riboflavin, having a maximum at 524 nm. The green fluorescent substance was extracted with cold water from the mushroom and it was identified as riboflavin by spectroscopic and chromatographic analyses. Riboflavin was concluded to be the light emitter of this mushroom.
Synthesis and chemiluminescence of copolymers of 5‐amino‐8‐vinyl‐phthalazine‐1, 4(2H,3H)‐dione with methyl methacrylate or styrene, and of α, ω‐bis[5‐amino‐phthalazine‐1,4 (2H,3H)‐dion‐]8‐yl alkanes [=α, ω‐bis(6‐luminyl) alkanes]: Investigations on an intramolecular ‘distance effect’
Authors: Gundermann Karl‐Dietrich , Lieske Dieter , Haase Brigitte , Baca Brigitte Hartmann‐Azanza 
Published: May 2005

AbstractOligomers of 5‐amino‐8‐vinyl‐phthalazine‐1,4(2H,3H)‐dione exhibit about 0.05% of the chemiluminescence quantum yield of the corresponding ‘monomer unit’, i.e. 5‐amino‐8‐ethyl‐phthalazine‐1,4(2H,3H)‐dione which has a similar quantum yield to luminol. The quantum yields of copolymers of 5‐amino‐8‐vinyl‐phthalazine‐1,4(2H,3H)‐dione (1a) with methyl methacrylate or with styrene increase up to 1000‐fold, relative to the quantum yield of oligomers of (1a). Thus the monomer units of methyl methacrylate or styrene appear to act as ‘spacers’ between the lumigenic groups.α,ω‐Bis[(5‐amino‐phthalazine‐1,4(2H,3H)‐dion‐)8‐yl] alkanes show an analogue ‘distance’ effect: the chemiluminescence quantum yield increases with increasing alkane chain length.As the fluorescence of the corresponding amino phthalates (which are intermediates in the synthesis of the phthalazine diones) is only slightly influenced by the distance between the lumigenic groups it is suggested that a mainly chemical ‘distance effect’ is working here: the smaller the intramolecular distance between the hydrazide groups the more inhibition exists in respect of the oxidative reaction producing the luminol‐type chemiluminescence.
Bioluminescent enzyme immunoassay for progesterone using monoclonal antibodies and glucose‐6‐phosphate dehydrogenase labels
Authors: Brochu Michèle , Carrié Marie‐Luce , Térouanne Béatrice , Bélanger Alain , Nicolas Jean‐Claude 
Published: May 2005

AbstractBacterial luciferase, NAD(P): FMN oxidoreductase and anti‐mouse immunoglobulin were co‐immobilized on Sepharose 4B. This reagent together with a progesterone glucose‐6‐phosphate dehydrogenase conjugate and various anti‐progesterone monoclonal antibodies was used to develop a non‐separation bioluminescent immunoassay for progesterone. This monoclonal antibody based assay was sensitive and reliable and using the tracer progesterone‐11‐acetate‐glucose‐6‐phosphate dehydrogenase, the majority of the monoclonal antibodies give a better sensitivity with this enzymatic tracer than that obtained with an iodinated tracer.In a second assay design progesterone‐glutathione was co‐immobilized with bacterial luciferase and NAD(P): FMN oxidoreductase on Sepharose 4B and three monoclonal antibodies were labelled with glucose‐6‐phosphate dehydrogenase. With aqueous progester‐one standards, this assay gave comparable sensitivity to the bioluminescent enzyme immunoassay using the second antibody immunoadsorbant and to an RIA but was unsuitable for plasma samples.
Inhibition of luminol‐dependent luminescence and simultaneous generation of native luminescence of activated human polymorphonuclear leukocytes by addition of albumin
Authors: Roschger Paul , Graninger Wolfgang , Klima Herbert 
Published: May 2005

AbstractLuminol‐dependent luminescence (LDL) and luminol‐independent, native luminescence (NL) of polymorphonuclear leukocytes were investigated with respect to the effects generated by the addition of albumin to the reaction medium. The cells were activated: (1) by simple surface attachment to a hydrophilic plastic, (2) by opsonized zymosan, (3) by phorbol myristate acetate, (4) by formylmethionyl‐leucyl‐phenylalaline. Both kinds of emissions were recorded simultaneously using a method of spectral discrimination. The addition of albumin resulted in an inhibition of LDL, which coincided with a generation of NL. The extent of the inhibition of LDL depended on the type of stimulus used. Maximum inhibition occurred with cells activated by attachment to plastic surfaces and minimum inhibition was observed with cells stimulated by opsonized zymosan. Different contributions of extracellularly released reactive oxygen‐species may be responsible for this. It appears possible to discriminate between intra‐ and extracellular sites of oxygen‐metabolites production using albumin simultaneously as extracellular quencher of LDL and as luminescent probe for NL.
Bioluminescent assay of ATPase activity in embryonic material using firefly luciferase
Authors: Hanocq‐Quertier J. , Baltus E. , Schram E. 
Published: May 2005

AbstractThe continuous bioluminescent assay of ATP has been adapted to the study of Mg2+‐dependent ATPases, including the (Na+,K+) pump, in amphibian tissues.A discrete bioluminescent assay procedure for ATPase has also been developed. Components of the firefly luciferase assay reagent modify the observed ATPase activity but this can be circumvented by performing discrete instead of continuous measurements of enzyme activity. In assays with commercial ATPase preparations the continuous bioluminescent assay procedure gave ATPase activities 2.2‐fold lower than obtained with the discrete procedure. In Xenopus oocyte or egg homogenates, in contrast, the total ATPase activity measured is stimulated eight times by the luciferase reagent, mainly through an unexplained activation of a Mg2+‐independent ATPase. In other tissues, such as Xenopus brain homogenates, both the continuous and discrete monitoring procedures are equally suitable for the determination of ATPase activity.
Lipopolysaccharide‐dependent enhancement of adherence‐mediated chemiluminescence response of polymorphonuclear leukocytes
Authors: Dwenger A. , Schweitzer Gertraud , Funck Monika 
Published: May 2005

AbstractAdherence of resting polymorphonuclear leukocytes to nylon fibre increased the chemiluminescence response (CL) from 99400 to 910300 cpm/25000 PMNL. This effect could be amplified by lipopolysaccharide (LPS) priming of granulocytes in a dose‐dependent fashion. The results of nylon fibre adherence experiments suggest an in vitro model that might approximate certain conditions of in vivo PMNL‐endothelial adherence and respiratory burst activation, and these reactions of polymorphonuclear leukocytes may contribute to the pathomechanisms of the Adult Respiratory Distress Syndrome.
Chemiluminescent determination of choline in cerebrospinal fluid and red blood cells
Authors: Molini G. , Verzé S. , Tosca P. , Zerbi F. , Savoldi F. 
Published: May 2005

AbstractThe concentration of choline in the cerebrospinal fluid (CSF) of patients affected by primary dementia and in red blood cells (RBC) of depressed patients before and after treatment with lithium salts was determined using a chemiluminescent assay. The mean CSF concentration of choline was found to be 60 pmoles/ml (SD = 20 pmoles/ml) and this was lower than values obtained previously by spectrophotometric‐colorimetric methods. Mean RBC choline concentrations before and after therapy with lithium salts were 20 nmoles/ml (SD = 16 nmoles/ml and 328 nmoles/ml (SD = 206 nmoles/l) respectively and these are similar to those reported previously (obtained by chemiluminescent and non‐chemiluminescent methods).
Determination of sterilization effectiveness by measuring bacterial growth in a biological indicator through firefly luciferase determination of ATP
Authors: Webster Joann J. , Walker Billy G. , Ford Sharon R. , Leach Franklin R. 
Published: May 2005

AbstractA bioluminescence procedure for measurement of microbial ATP allows a rapid determination of the effectiveness of autoclave sterilization. This determination is achieved faster than detection of acid production in a biological indicator via a pH indicator. Bacterial outgrowth from spores on test strips of the biological indicator was detected by measurement of ATP using the firefly luciferase reaction. A measureable increase in ATP was found after 5 hours of incubation of a biological indicator that had been treated under sterilizing conditions that produced 75% sterility of the biological indicator as measured by acid production. This is a marked improvement over the 24‐48 hours of incubation currently required.
Extra‐weak chemiluminescence of drugs. VIII. Extra‐weak chemiluminescence arising from the amino‐carbonyl reaction
Authors: Kurosaki Yuichiro , Sato Hideaki , Mizugaki Michinao 
Published: May 2005

AbstractExtra‐weak chemiluminescence (CL) from amino‐carbonyl reactions of L‐lysine with various sugars and aldehydes in aqueous solution was examined. Amongst the aldehydes and sugars tested, glycolaldehyde and D‐arabinose produced the highest CL intensity. The CL of the amino‐carbonyl reaction reached a maximum after about 60 minutes. The CL was pH dependent, and a linear relation between CL intensity and hydroge‐ion concentration was demonstrated. Low oxygen levels inhibited CL and no CL was produced in nitrogen purged solutions. Addition of cupric or ferrous ion, decreased the CL. The involvement of free radical intermediates was demonstrated by ESR. Our findings suggest that the CL of the amino‐carbonyl reaction arises from free radicals derived from melanoidines or their intermediates. CL should prove useful for evaluating the stability of crude drugs extracted from natural resources that contain various amino acid derivatives protein and sugar components.
Bioluminescent flow sensors: L‐lactate dehydrogenase activity determination in serum
Authors: Girotti Stefano , Bassoli Cinzia , Cascione Maria Loredana , Ghini Severino , Carrea Giacomo , Bovara Roberto , Roda Aldo , Motta Roberto , Petilino Roberto 
Published: May 2005

AbstractThe catalytic activity of serum L‐lactate dehydrogenase (LDH), was determined by monitoring the NADH produced by LDH with bacterial bioluminescent enzymes immobilized on a nylon coil.The LDH reaction of L‐lactate with NAD took place in a flow‐through mixing coil that preceded the bioluminescent detector coil. The response was linear from 1 to 5000 U/l at 37°C and from 3 to 2000 U/l at 25°C. The intra‐ and inter‐assay reproducibility (CV%) were less than 10% and recovery range was 92% to 110%. The results agreed well with those obtained with a spectrophotometric method.
A sensitive CCD image system for detection of chemiluminescent reactions
Authors: Jansen Eugène H. J. M. , Buskens Carin A. F. , van den Berg Rijk H. 
Published: May 2005

AbstractA new ultra‐sensitive light detection system is described for the detection of chemiluminescence reactions. The system consists of a CCD camera equipped with a two‐stage image intensifier coupled to an image analysis system with real‐time filtering capabilities. The sensitivity was determined with the enhanced chemiluminescence system using horseradish peroxidase as label. Additional possibilities for further increase in sensitivity and the potential use in immuoassays and other applications are discussed.
The effect of quenchers on the chemiluminescence of luminol and lucigenin
Authors: Bottu G. 
Published: May 2005

AbstractThe chemiluminescence of luminol and lucigenin is often used to detect the production of reactive oxygen derivatives by phagocytic cells. Also, several quenchers and enzyme inhibitors are used to determine which oxygen derivatives are responsible for the observed effects. In the present work we have assessed the reliability of dimethylthiourea and cysteamine (OH. quenchers), desferrioxamine (iron chelator) and diethyldithiocarbamate (superoxide dismutase inhibitor). They all react with CIO− and are also strong inhibitors of the luminescence of luminol catalysed by horseradish peroxidase (HRP); cysteamine and diethyldithiocarbamate also react with H2O2. NaN3 is an inhibitor of myeloperoxidase and a quencher of singlet O2, but we found that under certain conditions it can amplify the the luminescence of luminol triggered by CIO− or Fenton's reagent. A complex of copper and penicillamine that had been proposed as an \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm O}_{\rm 2} ^{\bar .} $\end{document} quencher, quenches all luminescent reactions studied. On the other hand, we were able to confirm the relative specificity of other quenchers: taurine for CIO−, benzoate for OH. and mannitol for both OH. and ‘crypto‐OH.’.
Measurement of phagocyte chemiluminescence using a microtitre plate luminometer
Authors: Blair Andrea L. , Cree Ian A. , Beck J. Swanson 
Published: May 2005

AbstractThe use of chemiluminescence techniques to study the interaction between bacteria and phagocytes has been useful for examining the extent to which serum factors, such as opsonins, are important in internalization of the organisms and the response of the cell to phagocytosed bacteria. However, such methods have been limited by the number of experiments which can be performed at one time using most commercial luminometers. However, the recent introduction of the Amerlite microtitre plate luminometer allows the measurement of chemiluminescence responses in 96‐well microtitre plates. Using this instrument, lucigenin‐enhanced chemiluminescence can be detected from as few as 5000 cells (polymorphonuclear leukocytes or monocytes) per well with a 1:10 ratio of cells to zymosan particles opsonized with 10% serum. The opsonic capacity of up to 100 sera can be measured in triplicate wells in a single experiment using four microtitre plates and polymorphonuclear leukocytes prepared from less than 40 ml freshly obtained venous blood. We are currently using this technique to investigate the effect of serum opsonins on the interaction between normal human polymorphonuclear leukocytes and monocytes with mycobacteria of three species (Mycobacterium leprae, M. tuberculosis, and M. aviumintracellulare). Other possible applications of this method are discussed.