bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of an enhanced luminol chemiluminescence reaction using 4‐[4,5‐di(2‐pyridyl)‐1H‐imidazol‐2‐yl]phenylboronic acid to photographic detection of horseradish peroxidase on a membrane
Authors: Kuroda Naotaka , Murasaki Naoko , Wada Mitsuhiro , Nakashima Kenichiro 
Published: January 2005

AbstractPhotographic detection of horseradish peroxidase (HRP) on a membrane by the luminol–hydrogen peroxide–HRP chemiluminescence reaction using 4‐[4,5‐di(2‐pyridyl)‐1H‐imidazol‐2‐yl]phenylboronic acid (DPPA) as an enhancer is described. The method is based on the long‐lived chemiluminescence emission obtained by using DPPA. Under the optimum conditions, as little as 0.10 ng (ca. 2.3 fmol) and 0.20 ng (ca. 4.6 fmol) per spot of HRP on a membrane were detected as visible spots with exposure time of 60 and 10 min, respectively, by using an instant photographic film and a camera luminometer. The proposed method was highly sensitive and was successfully applied to the detection of HRP conjugates as an alternative to the colorimetric method using a chromogenic substrate in a commercially available assay kit of Western blotting. Copyright © 2001 John Wiley & Sons, Ltd.
Intrinsic fluorescence of enzymes and fluorescence of chemically modified enzymes for analytical purposes: a review
Authors: Galbán Javier , Andreu Yolanda , Sierra Jose F. , de Marcos Susana , Castillo Juan R. 
Published: January 2005

AbstractIn recent years our research group has developed new alternatives for fluorescence enzymatic determinations. First, we observed that the intrinsic fluorescence of enzymes changes during enzymatic reactions, proportionally to the substrate concentration, avoiding the combination of the enzymatic reaction with a fluorophore‐involving reaction. The main disadvantage of this method is that the excitation and emission wavelengths of the enzymes are in the UV region of the spectrum. An alternative to overcome this problem consisted of covalently bonding the enzyme to a fluorophore. In this paper, an overview is given of all of the applications and future developments on both types of alternatives that we have developed. Apart from the analytical charactersitics of the methods, we have also reviewed all of the information about mathematical models we have elaborated to date. Copyright © 2001 John Wiley & Sons, Ltd.
Importance of the ionization states of m‐THPC for its HPLC fluorescence detection
Authors: Desroches M.‐C. , Bourdon O. , Morokro Y. , Chaminade P. , Blais J. , Prognon P. , Kasselouri A. 
Published: January 2005

AbstractAn original, rapid and sensitive high‐performance liquid chromatographic (HPLC) method has been developed for the detection of 5, 10, 15, 20 tetra‐meso‐hydroxyphenylchlorine (m‐THPC), a photosensitizer used in the photodynamic therapy (PDT) of cancers. Chromatographic separation was carried out on a C8 Zorbax® column (80 × 4 mm, 5 µm). The mobile phase was an ethanol/aqueous sulphuric acid, pH 2.0 (65/35 v/v), in an isocratic mode yielding to rapid analysis (3.1 min) with narrow peaks. As the fluorescence intensity was found to be highly pH‐dependent and to increase with pH values, a post‐column device prior to the fluorescence detection (λexc = 423 nm, λem = 650 nm) was used to allow the addition of a 0.05 mol/L Na2HPO4 solution to the mobile phase. Compared to standard conditions, a 300% increase of the fluorescence intensity was obtained for optimized operating conditions using experimental design. The validation of this analytical method showed that the response function was linear for concentrations up to 1000 µg/L (1.47 × 10−6 mol/L) with a detection limit of 188 pg (S/N = 3). Copyright © 2001 John Wiley & Sons, Ltd.
Relationship between conformation of polysaccharides ­in the dilute regime and their interaction with a phospholipid bilayer
Authors: Girod S. , Cara L. , Maillols H. , Salles J. P. , Devoisselle J. M. 
Published: January 2005

AbstractInteractions between polysaccharides and phospholipid bilayers have already been demonstrated in the literature but little is known about the influence of macromolecule conformations related to the solvent characteristics (pH, ions, ionic strength). In this study we have investigated the conformation of iono‐ and thermo‐sensitive polysaccharides, iota‐ and kappa‐carrageenans, and their interaction with a dimyristoylphosphatidylcholine (DMPC) model bilayer. The study was performed in two different media (NaCl 150 mmol/L, pH 6.5, and NaCl 300 mmol/L, pH 6.5). In the first part, the iota‐ and kappa‐carrageenan samples have been characterized by size exclusion chromatography (SEC) coupled with a multi‐angle laser light‐scattering detector (MALLS). The SEC–MALLS results clearly show polysaccharide chain association at high ionic strength. In the second part, the polysaccharide–membrane interaction has been studied, using fluorescent probes embedded in the membrane. The thermotropic properties of the membrane were investigated by fluorescence depolarization of 1‐(4‐trimethylammonium‐phenyl)‐6‐phenyl‐1,3,5‐hexatriene (TMA‐DPH). The membrane surface accessibility was evaluated by fluorescence quenching of 2‐(9‐anthroyloxy) stearic acid (2‐AS). Whatever the ionic strength tested, the polysaccharide presence notably enhances the membrane fluidity below the Tm. This sign of an interaction in the polar level of the membrane is more marked at low NaCl concentration. In contrast, the liposomes bilayer accessibility is drastically lowered when increasing the ionic strength. This is induced by macromolecular chain adsorption on the liposome surface, enhanced by the polysaccharide chain association. An ionic strength enhancement induces a conformational modification of the polysaccharide chains which modifies their ability to interact with the bilayer. Copyright © 2001 John Wiley & Sons, Ltd.
Exploiting sensitive laser‐induced fluorescence detection on electrophoretic microchips for executing rapid clinical diagnostics
Authors: Ferrance Jerome , Landers James P. 
Published: January 2005

AbstractFluorescence is used as a sensitive detection technique for current clinical diagnostics procedures involving slab gel separations of DNA. In transferring electrophoretic separations to smaller formats, first capillaries and then microchips, the size of the sample being separated has decreased considerably, making it necessary to routinely detect a few hundred molecules of each component in the sample. Laser‐induced fluorescence detectors provide high sensitivity and can be employed in both direct and indirect modes to detect clinically relevant compounds. A number of examples show that there is no loss of clinical diagnostic capability in moving these analyses to microchip devices. Microchips also allow for parallel processing of samples by incorporating multiple channels in a single device, with a number of strategies possible for using LIF detection in these multiplex systems. Copyright © 2001 John Wiley & Sons, Ltd.
Kinetic analysis of bacterial bioluminescence in water–organic media
Authors: Sukovataya I. E. , Tyulkova N. A. 
Published: January 2005

AbstractThe interaction of luciferases from two types of luminous bacteria, Photobacterium leiognathi and Vibrio harveyi, with their substrates [the photorecovered FMNH2 and long‐chain aldehydes—decanal (C10), dodecanal (C12) and tetradecanal (C14)] in water–organic media was analysed using kinetic graphical methods. Moderate concentrations of organic solvents have been demonstrated to activate the bioluminescence, while higher concentrations inhibit it. The interactions of these effectors with luciferases show different types of kinetics, which depend on concentrations of solvents, kinds of enzymes and substrates. The apparent value of the Michaelis constant, Km, for C14 of both luciferases and for C10 of luciferase V. harveyi is enhanced with increasing concentration of the organic solvent, but Km for C12 and C10 of luciferase P. leiognathi decreases. Obviously, at the specific binding of aldehydes with luciferases in the first case, hydrophobic interactions are realized, but in second, the electrostatic interactions are realized. The series of changes in parameters of bioluminescence reaction catalysed by different luciferases is obviously determined by their structural peculiarities. Copyright © 2001 John Wiley & Sons, Ltd.
Design and synthesis of chemiluminescent substrates with high luminescent efficiency in an aqueous system: 5‐tert‐butyl‐4,4‐dimethyl‐2,6,7‐trioxabicyclo[3.2.0]heptanes bearing a 3‐hydroxy‐4‐(1‐iminoethyl)phenyl moiety at the 1‐position
Authors: Matsumoto Masakatsu , Sakuma Toshimitsu , Watanabe Nobuko 
Published: January 2005

AbstractA CIEEL‐active dioxetane bearing a 4‐acetyl‐3‐hydroxyphenyl moiety has very recently been found to emit light effectively, even in an aqueous system, albeit with a very slow CIEEL decay rate. As an attempt to improve the CIEEL decay rate of this type of dioxetane, three dioxetanes, in which a carbonyl in the 4‐acetyl‐3‐hydroxyphenyl moiety was modified into an oxime, oxime O‐methyl ether, or semicarbazone, were synthesized. These three dioxetanes decomposed to emit light far more rapidly than the parent 4‐acetyl‐3‐hydroxyphenyl‐substituted dioxetane. Among them, a dioxetane bearing a 3‐hydroxy‐4‐(1‐methoxyiminoethyl) phenyl, namely an oxime O‐methyl ether derivative, gave high chemiluminescent efficiency. As for a semicarbazone derivative, decrease of the chemiluminescent yield was minimal, even in an aqueous system. Copyright © 2001 John Wiley & Sons, Ltd.
Chemiluminescent acridan phosphate labelling compounds for detection in gels
Authors: Akhavan‐Tafti Hashem , DeSilva Renuka , Sugioka Katsuaki , Handley Richard S. , Schaap A. Paul 
Published: January 2005

AbstractWe have developed a chemiluminescent acridan phosphate labelling compound which produces a flash of light upon chemical triggering. Sequential treatment of the label with acid and a strong base, one of which contains a peroxide, initiates light emission as a rapid flash lasting 1–2 s. Labelling of analytes with these compounds permits their direct detection in a non‐enzymatic assay format. Representative compounds have been linked to BSA as a model protein analyte and detected by chemiluminescence assay. Light intensity correlated with the amount of BSA over six orders of magnitude, permitting the detection of 50 amol of protein in solution. We have also demonstrated for the first time that labelled proteins can be separated by electrophoresis without destruction of the label and that chemiluminescence can be produced and detected directly in the gel. The ease, speed and sensitivity of detection by this new method should enable the development of simpler assays for a wide variety of analytes. Copyright © 2001 John Wiley & Sons, Ltd.
Influence of carbon disulphide on hydroxyl radicals in the phenanthroline chemiluminescence system
Authors: Jian Le , Chiang Huai 
Published: January 2005

AbstractWe investigated the effects of carbon disulphide (CS2) on hydroxyl radical generation using the phenanthroline chemiluminescence system. The influence of CS2 on the phenanthroline chemiluminescence system without CuSO4 and vitamin C were tested. The results showed that CS2 enhanced the emission intensity of chemiluminescence and advanced the peak time of the chemiluminescence. There was a dose–effect relationship between CS2 concentrations (0–160 mg/ml) and chemiluminescence peak intensity (r = 0.955, R2 = 0.913, p = 0.003), as well as CS2 concentrations and peak time (r = −0.927, R2 = 0.860, p = 0.008). The enhanced chemiluminescence induced by CS2 could be inhibited by thiourea, and the inhibition rate gradually deceased along with increasing CS2 concentration (r = −0.816, R2 = 0.666, p = 0.048). When the system was free of CuSO4 and vitamin C, CS2 also induced the emission of chemiluminescence intensity. We conclude from these results that CS2 can induce the phenanthroline chemiluminescence system to generate hydroxyl radicals and advance the peak time, and that thiourea can inhibit the effect. The mechanism may be explained by a catalytic effect of CS2 directly on H2O2. Copyright © 2001 John Wiley & Sons, Ltd.
A study of common interferences with the forensic luminol test for blood
Authors: Quickenden T. I. , Creamer J. I. 
Published: January 2005

AbstractA wide range of domestic and industrial substances that might be mistaken for haemoglobin in the forensic luminol test for blood were examined. The substances studied were in the categories of vegetable or fruit pulps and juices; domestic and commercial oils; cleaning agents; an insecticide; and various glues, paints and varnishes. A significant number of substances in each category gave luminescence intensities that were comparable with the intensities of undiluted haemoglobin, when sprayed with the standard forensic solution containing aqueous alkaline luminol and sodium perborate. In these cases the substance could be easily mistaken for blood when the luminol test is used, but in the remaining cases the luminescence intensity was so weak that it is unlikely that a false‐positive test would be obtained. In a few cases the brightly emitting substance could be distinguished from blood by a small but detectable shift of the peak emission wavelength. The results indicated that particular care should be taken to avoid interferences when a crime scene is contaminated with parsnip, turnip or horseradish, and when surfaces coated with enamel paint are involved. To a lesser extent, some care should be taken when surfaces covered with terracotta or ceramic tiles, polyurethane varnishes or jute and sisal matting are involved. Copyright © 2001 John Wiley & Sons, Ltd.
Aerobic biodegradation of N‐nitrosodimethylamine (NDMA) by axenic bacterial strains
Authors: Sharp Jonathan O. , Wood Thomas K. , Alvarez‐Cohen Lisa 
Published: January 2005

AbstractThe water contaminant N‐nitrosodimethylamine (NDMA) is a probable human carcinogen whose appearance in the environment is related to the release of rocket fuel and to chlorine‐based disinfection of water and wastewater. Although this compound has been shown to be biodegradable, there is minimal information about the organisms capable of this degradation, and little is understood of the mechanisms or biochemistry involved. This study shows that bacteria expressing monooxygenase enzymes functionally similar to those demonstrated to degrade NDMA in eukaryotes have the capability to degrade NDMA. Specifically, induction of the soluble methane monooxygenase (sMMO) expressed by Methylosinus trichosporium OB3b, the propane monooxygenase (PMO) enzyme of Mycobacterium vaccae JOB‐5, and the toluene 4‐monooxygenases found in Ralstonia pickettii PKO1 and Pseudomonas mendocina KR1 resulted in NDMA degradation by these strains. In each of these cases, brief exposure to acetylene gas, a suicide substrate for certain monooxygenases, inhibited the degradation of NDMA. Further, Escherichia coli TG1/pBS(Kan) containing recombinant plasmids derived from the toluene monooxygenases found in strains PKO1 and KR1 mimicked the behavior of the parent strains. In contrast, M. trichosporium OB3b expressing the particulate form of MMO, Burkholderia cepacia G4 expressing the toluene 2‐monooxygenase, and Pseudomonas putida mt‐2 expressing the toluene sidechain monooxygenase were not capable of NDMA degradation. In addition, bacteria expressing aromatic dioxygenases were not capable of NDMA degradation. Finally, Rhodococcus sp. RR1 exhibited the ability to degrade NDMA by an unidentified, constitutively expressed enzyme that, unlike the confirmed monooxygenases, was not inhibited by acetylene exposure. © 2005 Wiley Periodicals, Inc.
RuII Complexes Incorporating Tetrathiamacrocycles: Synthesis and Conformational Analysis
Authors: Adams Harry , Amado A. M. , Félix Vitor , Mann Brian E. , Antelo‐Martinez Jorge , Newell Mike , Ribeiro‐Claro Paulo J. A. , Spey Sharon E. , Thomas James A. 
Published: January 2005

AbstractThe synthesis of a series of RuII complexes incorporating thiacrown ligands ([12]ane‐S4, [14]ane‐S4, [16]ane‐S4), as well as 2,2′‐bipyridine (bpy) or pyridine, is reported. Structural studies on these complexes have been carried out using a variety of techniques. Detailed 1H NMR spectroscopic studies on the previously reported [Ru([12]ane‐S4)(bpy)]2+ (1) reveal that—contrary to earlier reports—the observed fluxional 1H NMR behavior is not due to chemical exchange involving cleavage of the bpy RuN bond but is, in fact, due to lone‐pair inversion of coordinated macrocyclic sulfur donor atoms. This phenomenon is also observed for the [14]ane‐S4 and [16]ane‐S4 analogues of 1. For the first time, using a combination of X‐ray crystallography, more detailed 1H NMR experiments, and computational methods, an in‐depth study on the energetics and dynamics of invertomer formation and conversion for macrocyclic coordination complexes has been carried out. These studies reveal that the steric constraints of assembling each sulfur macrocycle and bpy ligand around the octahedral RuII center lead to close intramolecular contacts. These contacts are largely dependent on the orientation of the electron lone pairs of equatorial sulfur donor atoms and correlate with the comparative stability of the different invertomeric forms. Thus, the conformational preferences of the three macrocyles in [Ru([n]ane‐S4)(bpy)]2+ complexes are determined by steric rather than electronic effects.
Tuning Single Nucleotide Discrimination in Polymerase Chain Reactions (PCRs): Synthesis of Primer Probes Bearing Polar 4′‐C‐Modifications and Their Application in Allele‐Specific PCR
Authors: Gaster Jens , Marx Andreas 
Published: January 2005

AbstractThere are many methods available for the detection of nucleotide variations in genetic material. Most of these methods are applied after amplification of the target genome sequence by the polymerase chain reaction (PCR). Many efforts are currently underway to develop techniques that can detect single nucleotide variations in genes either by means of, or without the need for, PCR. Allele‐specific PCR (asPCR), which reports nucleotide variations based on either the presence or absence of a PCR‐amplified DNA product, has the potential to combine target amplification and analysis in one single step. The principle of asPCR is based on the formation of matched or mismatched primer–target complexes by using allele‐specific primer probes. PCR amplification by a DNA polymerase from matched 3′‐primer termini proceeds, whereas a mismatch should obviate amplification. Given the recent advancements in real‐time PCR, this technique should, in principle, allow single nucleotide variations to be detected online. However, this method is hampered by low selectivity, which necessitates tedious and costly manipulations. Recently, we reported that the selectivity of asPCR can be significantly increased through the employment of chemically modified primer probes. Here we report further significant advances in this area. We describe the synthesis of various primer probes that bear polar 4′‐C‐modified nucleotide residues at their 3′ termini, and their evaluation in real‐time asPCR. We found that primer probes bearing a 4′‐C‐methoxymethylene modification have superior properties in the discrimination of single nucleotide variations by PCR.
Synthesis of trans‐1, trans‐2, trans‐3, and trans‐4 Bisadducts of C60 by Regio‐ and Stereoselective Tether‐Directed Remote Functionalization
Authors: Sergeyev Sergey , Schär Michael , Seiler Paul , Lukoyanova Olena , Echegoyen Luis , Diederich François 
Published: January 2005

AbstractThe double Bingel reaction of fullerene C60 with bismalonates attached to a Tröger base derived tether afforded trans‐1, trans‐2, trans‐3, and trans‐4 bisadducts with excellent regioselectivity. In particular, enantiomerically pure bisadducts with inherently chiral trans‐2 or trans‐3 addition patterns were prepared starting from enantiomerically pure bismalonates. The absolute configuration of the trans‐2 and trans‐3 bisadducts was established from their CD spectra. The excellent diastereoselectivity in the double additions to give the trans‐2 bisadducts is particularly remarkable given the large distance between the two reacting bonds in opposite hemispheres of the fullerene that is spanned by the tether. Now, all inherently chiral double addition patterns are readily available by tether‐directed functionalization using appropriate chiral, nonracemic spacers.
Preparation of MoO3‐V2O5Nanowires with Controllable Mo/V Ratios inside SBA‐15 Channels Using a Chemical Approach with Heteropoly Acid
Authors: Yue Bin , Tan De‐Jun , Yan Shi‐Run , Zhou Yan , Zhu Ka‐Ke , Pan Jian‐Feng , Zhuang Ji‐Hua , He He‐Yong 
Published: January 2005

AbstractA new approach was developed to fabricate nanowires of mixed oxides MoO3‐V2O5inside the channels of mesoporous silica SBA‐15. The method involves functionalization of the channel surface of SBA‐15 with aminosilane groups, immobilization of Keggin‐type molybdovanadophosphoric acids through an acid‐base interaction, and heat treatment. The immobilization of the heteropolyacid containing mixed addenda makes the molar ratio of the loaded components controllable. The formation of the MoO3‐V2O5nanowires inside the channels was monitored by variable temperaturein situXRD. The materials obtained by heat treatment at 400 °C for 5 h were characterized by TEM, N2‐sorption measurements, laser Raman spectra and UV‐Vis diffuse reflectance spectra. Further heat treatment of the MoO3‐V2O5nanowires inside the SBA‐15 channels at higher temperature (700 °C) destroys the framework integrity of SBA‐15 by complete sublimation of MoO3through the SBA‐15 channel walls.
Determination of Carbohydrazide and Kinetics of Condensation reaction of Carbohydrazide with Malachite Green by Spectrophotometry
Authors: Wu Tao , Zhang Tong‐Lai , Chen Hong‐Yan , Zhang Jian‐Guo 
Published: January 2005

AbstractThe kinetics of the condensation reaction of malachite green and carbohydrazide was studied by spectrophotometry in aqueous solution in the temperature range of 15.0–22.0 °C. The reaction was found to be second‐order overall, first‐order with respect to each reactant. The effect of ionic strength on the reaction has negative salt effect in the range of 0.2–1.0 mol˙L–1. A mechanism of the reaction between malachite green and carbohydrazide was proposed, and the rate equation derived from the mechanism can explain all experimental observations properly. Based on this reaction, a method of determining the content of carbohydrazide in the concentration range of (0.02–0.5)×10−3 mol·L−1 was proposed.
Study on the Interaction of Ternary Complex Pd(II)‐2,2′‐bipyridine‐L‐asparagic acid with DNA
Authors: Gao En‐Jun , Zhao Shu‐Min , Zhang Dan , Liu Qi‐Taob 
Published: January 2005

AbstractThe ternary complex Pd(II)‐2,2′‐bipyridine‐L‐asparagic acid was synthesized and characterized by elemental analysis, IR‐spectra and molar conductance. The formula of the complex is Pd(bipy)(L‐asp). The interaction of the complex with DNA has been studied by UV‐spectra, fluorescence spectra, CD‐spectra and gel electrophoresis. The results showed that the interaction of the complex with DNA performed mainly in intercalative mode and the extent of interaction was dependent on the concentration of the complex.
Fluorescence Study on the Interaction between Naproxen and Yeast DNA
Authors: Ye Bao‐Fen , Zhang Zhi‐Jie , Ju Huang‐Xian 
Published: January 2005

AbstractThe interaction between naproxen and yeast DNA was studied using fluorescence spectrometry and ultra‐violet (UV) spectrometry. The addition of yeast dsDNA to naproxen solution resulted in a strong fluorescence quenching. Both the Stern‐Volmer and the Scatchard plots of the fluorescence quenching showed a curve with two slopes and a threshold DNA concentration of about 100 µmol·L−1. The interaction between naproxen and the dsDNA was found to be a groove binding mode by UV spectra, the influence of ion strength and I− quenching effect. This mode was independent on DNA concentration. However, the increase in DNA concentration changed the binding constant K of naproxen to yeast dsDNA and the number of binding sites in DNA base pairs (n).