bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study of the interaction of hexa‐amine cobalt (III) ion with DNA by a resonance light scattering technique and its analytical application
Authors: Li Zheng‐ping , Li Yan‐kun , Wang Yu‐cong 
Published: August 2005

AbstractThe effect of hexa‐amine cobalt cations on the DNA condensation in aqueous solution was investigated by resonance light scattering (RLS). When the relative concentration of hexa‐amine cobalt (III) cations to DNA is in the appropriate range, the cations will induce DNA condensation and aggregation, which results in a strong RLS spectrum characterized by a peak at 290.0 nm. The RLS technique is a powerful tool for monitoring DNA condensation and, under optimal conditions, the enhanced RLS intensity at 290.0 nm was proportional to the concentration of DNA in the range 0.01–6.0 µg/mL. Based on this, a sensitive and convenient analysis method for the microdetermination of DNA was established. The detection limit (3 s) of calf thymus DNA by the proposed method is 1.9 ng/mL and few substances interfere in the DNA determination. Copyright © 2005 John Wiley & Sons, Ltd.
Use of molecule imprinting–chemiluminescence method for the determination of tamoxifen in breast cancer sufferers' urine
Authors: Nie Fei , Lu Jiuru , He Yunhua , Du Jianxiu 
Published: August 2005

AbstractThe reaction between soluble Mn(IV) and tamoxifen can produce chemiluminescence and formaldehyde can enhance this chemiluminescence reaction. A tamoxifen molecular imprinted polymer (MIP) was synthesized and its adsorption selectivity to tamoxifen in aqueous solution was evaluated. Using a synthesized tamoxifen MIP as the recognition material and a soluble Mn(IV)–formaldehyde–tamoxifen chemiluminesence system as the detection system, a new molecule imprinting–chemiluminesence method of determination of tamoxifen was established. The response range of this method was 1.0 × 10−7–6.0 × 10−6 g/mL, with a linear correlation coefficient of 0.997. The detection limit was 4 × 10−8 g/mL. The relative standard deviation for 5.0 × 10−7 g/mL tamoxifen solution was 4.1% (n = 9). Copyright © 2005 John Wiley & Sons, Ltd.
Spectral and kinetic studies on the interaction between oxyhaemoglobin and peroxynitrite: a comparison with hydrogen peroxide
Authors: Wang Rui‐yong , Ji Mi‐na , Cai Ru‐xiu , Lu Ying‐tang 
Published: August 2005

AbstractInteraction between oxyhaemoglobin and peroxynitrite was studied using stopped‐flow rapid‐scan spectrophotometry. The influence of pH, peroxynitrite concentration and temperature on the pseudo‐first‐order rate constants was studied and the activation energy calculated. The kinetic curve for the oxyhaemoglobin–peroxynitrite reaction showed that a fast reaction occurred in the initial seconds, followed by a slow process of decrease in absorbance. The biphasic reaction kinetics of oxyhaemoglobin with peroxynitrite or hydrogen peroxide demonstrated the existence of an intermediary species. For the first time a rapid‐scan stopped‐flow spectrophotometry study is presented, yielding spectral and kinetic data of the reaction. Copyright © 2005 John Wiley & Sons, Ltd.
Synthesis and fluorescence properties of the europium(III) chelate of a polyacid derivative of terpyridine
Authors: Wang Zhen , Yuan Jingli , Matsumoto Kazuko 
Published: August 2005

AbstractA new polyacid derivative ligand of biphenyl‐substituted terpyridine, [4′‐(biphenyl‐4′″‐yl)‐2,2′:6′2″‐terpyridine‐6,6″‐diyl]bis(methylenenitrilo)tetrakis(acetic acid) was synthesized, and the fluorescence properties of its Eu3+ and Tb3+ chelates were investigated. The Eu3+ chelate of the ligand is strongly fluorescent, with a fluorescence quantum yield of 0.156, molar absorption coefficient of 2.95 × 104 mol/L/cm at molar absorption maximum of 336 nm, and fluorescence lifetime of 1.29 ms, whereas its Tb3+ chelate is non‐fluorescent. Copyright © 2005 John Wiley & Sons, Ltd.
A novel flow‐injection chemiluminescence system for the determination of guanine
Authors: Mei Yang , Ran Liu , Dongyan Hou , Yuying Guo 
Published: August 2005

AbstractA novel flow‐injection chemiluminescence (CL) method for the determination of guanine was developed. The procedure is based on the CL reaction of guanine with hydrogen peroxide in borax buffer (pH 8.5) with Co2+ as a catalyst. The calibration graph is linear within the range of 3 × 10−7–9 × 10−5 g/mL. A detection limit of 1 × 10−7 g/mL, along with a relative standard deviation of 2.23% (3 × 10−7 g/mL guanine, n = 11), were obtained. The present procedure was applied to the measurement of guanine in urine with recoveries of 97.5–107.5%. A possible CL mechanism of the reaction system is proposed. Copyright © 2005 John Wiley & Sons, Ltd.
Study on effects of cyclodextrins on the photolysis of dissolved anthracene by fluorometry
Authors: Chunmao Li , Junze Mu , Yong Zhang 
Published: August 2005

AbstractA simple, fast and effective fluorescence method for studying on photolysis of dissolved anthracene (An) in cyclodextrins (CDs) aqueous solutions was developed. With this method the effects of five kinds of cyclodextrin on photolysis of dissolved An were investigated. It was found that all of the CDs promoted the photolysis of An, due to the incorporation of An into the cavity of CDs, in which self‐quenching of triplet‐state An was inhibited and the lifetime of singlet‐state An was prolonged. Hence, the possibility of the attack of oxygen on An was enhanced and more singlet‐state oxygen was produced. The effect of cavity size and steric hindrance of substituents of CDs on photolysis of An was explored. The order of the promotion effect for the five kinds of CDs was as follows: HPCD(hydroxypropyl‐β‐CD) > DMCD(heptakis(2,6‐di‐O‐methyl)‐β‐CD > β‐CD > γ‐CD > α‐CD. Copyright © 2005 John Wiley & Sons, Ltd.
Chemiluminescence micro‐flow‐injection analysis on a chip
Authors: Zhang Zhujun , He Deyong , Liu Wei , Lv Yi 
Published: August 2005

AbstractChemiluminescence microflow‐injection analysis (µFIA) systems on a chip have been developed. The technology of laser ablation was used to fabricate the microchannels on the polymethyl methacrylate (PMMA) chip. The three sampling structure, including double‐tee sampling structure, microvalve sampling structure and injection pump with accurate time control, were used. The microcolumn for specific molecular recognition, including molecularly imprinted polymer, enzyme and bacteria, were used to enhance selectivity. These µFIA systems have been applied to clinical analysis, assessment of food safety, in vivo and real‐time determination of drugs, and pharmacokinetics studies. Copyright © 2005 John Wiley & Sons, Ltd.
Chemiluminescence microflow injection analysis system on a chip for the determination of uric acid without enzyme
Authors: He Deyong , Zhang Zhujun , Huang Ying , Hu Yufei , Zhou Houjiang , Chen Dinglong 
Published: August 2005

AbstractA new microflow injection analysis (µFIA) system on a chip coupled with chemiluminescence (CL) for the non‐enzymatic determination of uric acid is described. The µFIA system produced by using two transparent poly(methylmethacrylate) (PMMA) chips measured 50 × 40 × 5 mm, the microchannels, etched by CO2 laser, were 200 µm wide and 100 µm deep, and the volume of the reaction area (RA) was about 1.2 µL. The injection pump, with accurate time control, monitored all reagents, including the sample. The uric acid was sensed by the chemiluminescence reaction between luminol and ferricyanide. The linear range of the uric acid concentration was 0.8–30 mg/L and the detection limit was 0.5 mg/L (S/N = 3). The relative standard deviation was 4.42% for 5 mg/L uric acid (n = 8). The proposed method has been successfully applied to the non‐separation determination of uric acid in human serum and urine. Copyright © 2005 John Wiley & Sons, Ltd.
Application of functional group modified substrate in room‐temperature phosphorescence, I—β‐cyclodextrin modified paper substrate for enrichment and determination of fluorene and acenaphthene
Authors: Zhu Ruohua , Wang Peilong , Wang Xiangfeng 
Published: August 2005

AbstractA novel method for the determination of fluorene and acenaphthene on solid phase extraction–room‐temperature phosphorescence (SPE–RTP) was studied. β‐cyclodextrin (β‐CD) was chemically bonded onto chromatography paper by reaction with epichorohydrin in an ultrasonic bath. The RTP signal of fluorene and acenaphthene included on the β‐CD‐modified paper was increased more than 10 times compared with non‐modified filter paper, indicating the formation of the inclusion complex. The conditions for the of RTP of compounds were studied in detail. The linear ranges of fluorene and acenaphthene concentrations to the RTP intensity were over two orders of magnitude (8.0 × 10−7–4.0 × 10−5 mol/L for fluorene) with a correlation coefficient of 0.999. The concentration limits of detection for fluorene and acenaphthene were 1.11 × 10−8 mol/L and 3.8 × 10−7 mo/L, respectively. When the sampling volume was 10 µL, the absolute LODs for fluorene and acenaphthene were 18.4 pg/spot and 0.58 ng/spot, respectively. The modified filter paper was used for solid phase extraction (SPE) and the retention behaviour of fluorene and acenaphthene was examined. The enrichment efficiency of the analytes was higher than 100‐fold. The SPE–RTP coupling technique was applied directly to the determination of fluorene and acenaphthnene in environmental water samples. Copyright © 2005 John Wiley & Sons, Ltd.
Perturbations induced by synthetic peptides from hepatitis G virus structural proteins in lipid model membranes: a fluorescent approach
Authors: Larios Cristina , Casas Jorge , Mestres Concepció , Haro Isabel , Alsina M. Asunción 
Published: August 2005

AbstractThe name HGV/GBV‐C remains as an acronym for hepatitis G virus (HGV) and GB virus‐C (GBV‐C), strain variants of this enveloped RNA virus independently but simultaneously discovered in 1995. Nowadays there is no evidence that it causes hepatitis in humans either during initial infection or after long‐term carriage, but it has been recently related with HIV regarding the inhibition of progression to AIDS.The overall genomic organization of HGV/GBV‐C is similar to that of hepatitis C virus (HCV) and other members of the Flavivirus family in Hepacivirus genus. Although a stretch of conserved, hydrophobic amino acids within the envelop glycoprotein of HCV has been proposed as the virus fusion peptide, the mode of entry of GBV‐C/HGV into target cells is at present unknown. In the present work, sequences derived from the structural E2‐protein of HGV/GBV‐C have been selected by means of semiempirical methods and then synthesized manually following solid‐phase methodologies. Their ability to induce perturbations in model membranes has been analysed by measuring the penetration of such peptides in lipid monolayers and by a series of experiments based on tryptophan peptide fluorescence emission spectra. Besides, release of vesicular contents to the medium was monitored by the ANTS/DPX assay. The membrane destabilization properties of these peptides was found very related with the lenght of the sequence. Copyright © 2005 John Wiley & Sons, Ltd.
Effect of a laminin amphiphatic sequence on DPPC ordered bilayers
Authors: Reig F. , Juvé A. , Ortiz A. , Sospedra P. , Alsina M. A. 
Published: August 2005

AbstractA peptide sequence, stearoyl‐GESIKVAVS(NH2), related to a laminin fragment, has been synthesized. Formation of aggregates was controlled by titrating a sodium anilinonaphthalene sulphonate (ANS) solution with peptide and recording fluorescence intensity increases. The results show that this system experiences a sudden increase in fluorescence at peptide concentrations around 2.5 × 10−4 mol/L. The interaction of this hydrophobic peptide with DPPC vesicles has been studied using fluorescence techniques. Its influence on the microviscosity of bilayers was determined by studying polarization/temperature dependence for ANS and diphenyl hexatriene (DPH) fluorescent probes. With both markers the presence of peptide promotes a clear increase in anisotropy values. This indicates a rigidifying effect. Leakage studies carried out with liposomes loaded with carboxyfluorescein (CF) indicate a stabilizing effect of the peptide on bilayers, in agreement with results obtained with fluorescent probes. Copyright © 2005 John Wiley & Sons, Ltd.
Neopterin in renal cell carcinoma: inhalational administration of interleukin‐2 is not accompanied by a rise of urinary neopterin
Authors: Melichar Bohuslav , Solichová Dagmar , Svobodová Iveta , Melicharová Karolina 
Published: August 2005

AbstractInhalational administration of interleukin‐2 (IL‐2) is effective in controlling renal cell carcinoma (RCC) lung metastases with minimal toxicity. Neopterin is an indicator of systemic immune activation in metastatic cancer and is increased after systemic IL‐2 administration. Urinary neopterin was investigated in 13 patients with metastatic RCC and 18 controls. In seven patients, urinary neopterin was followed before and after treatment with inhalational IL‐2. Neopterin was measured by highperformance liquid chromatography and creatinine was determined by Jaffé reaction. Urinary neopterin was significantly increased in patients with metastatic RCC compared to controls (257 ± 263 µmol/mol creatinine vs. 110 ± 41 µmol/mol creatinine; Mann–Whitney U‐test, p < 0.05). Median survival was significantly longer in patients with urinary neopterin <173 µmol/mol creatinine compared to patients with neopterin ≥173 µmol/mol creatinine (698 vs. 245 days; log‐rank test, p < 0.05). No significant increase was observed after inhalational IL‐2 therapy (147 ± 101 vs. 153 ± 54 µmol/mol creatinine). We conclude that urinary neopterin is increased in patients with metastatic RCC, and higher neopterin concentrations are indicative of poor prognosis. The absence of an increase in urinary neopterin after inhalational IL‐2 therapy is in accord with the lack of significant systemic toxicity. Copyright © 2005 John Wiley & Sons, Ltd.
Flow‐injection with enhanced chemiluminescence detection of ofloxacin in human plasma
Authors: Zhang Xianhua , Ouyang Jin , Zhai Suodi , Huang Guangming , Zhao Huichun 
Published: August 2005

AbstractA simple, rapid and sensitive method for the determination of ofloxacin in plasma has been developed based on flow‐injection analysis with enhanced chemiluminescence (CL) detection. This method employs the CL reaction of cerium(IV) and sulphite sensitized by a Tb(III)–ofloxacin complex. Plasma samples were deproteinized with acetonitrile before analysis. Under optimal conditions, the method allowed the quantitative analysis of ofloxacin in plasma over the range of 22.5–900 ng/mL with a detection limit of 7.5 ng/mL (3σ). The intra‐day and inter‐day precision was < 3.0% (n = 11) and < 7.0% (n = 3), respectively. The method was a convenient tool, rapid (20 s/analysis) and well suited for pharmacokinetics studies in which thousands of samples must be analysed daily. It was applied to pharmacokinetics studies of ofloxacin. Copyright © 2005 John Wiley & Sons, Ltd.
Separation and determination of bupivacaine in plasma by capillary electrophoresis with tris(2,2′‐bipyridyl)ruthenium(II) electrochemiluminescence detection
Authors: Wu Yayan , Li Tian , Liang Heng , Xue Jing 
Published: August 2005

AbstractA new, rapid, selective and sensitive method is described for determination of bupivacaine by capillary electrophoresis coupled with tris(2,2′‐bipyridyl)ruthenium(II) [Ru(bpy)32+] electrochemiluminescence detection. The influence of parameters such as detection potential, Ru(bpy)32+ concentration, buffer concentration and pH, injection time and separation voltage on separation efficiency and ECL peak intensity was systematically investigated. Under optimized conditions, the calibration curve was linear in the range 0.02–10 µg/mL. The RSD was 4.0% (n = 6). The detection limit was 3 ng/mL. The recoveries obtained were about 90%. This method was tested in the analysis of plasma samples taken from a rat after it had received bupivacaine injections. Copyright © 2005 John Wiley & Sons, Ltd.
Immunosorbent assay microchip system for analysis of human immunoglobulin G on MagnaBind™ carboxyl derivatized beads
Authors: Chen Tian , Lei Jian‐Du , Tong Ai‐Jun 
Published: August 2005

AbstractAn immunosorbent assay system was integrated into a PMVS microchip. MagnaBind™ carboxyl derivatized beads were introduced into a microchannel, and then human immunoglobulin G (IgG) was bound to the bead surface in the microchannel of the chip. Immunoreaction was conducted in the microchannel for the bead‐bounded antigen IgG with the antibody FITC‐labelled IgG. On‐chip detection was performed using a laser‐induced fluorescence (LIF) system. The integration shortened the overall analysis time from 7 h to less than 40 min. Copyright © 2005 John Wiley & Sons, Ltd.
A research on determination of explosive gases utilizing cataluminescence sensor array
Authors: Cao Xiaoan , Zhang Xinrong 
Published: August 2005

AbstractIn this paper, we propose a model of a sensor array system, which consists of three cataluminescence sensors based on nanosized SrCO3, γ‐Al2O3 and BaCO3 as catalysts, for quantitative analysis of the explosive gases of propane, n‐butane and iso‐butane in a mixture. Six linear regression equations of the cataluminescence intensity vs. the gas concentrations in the range 2000–10 000 ppm were established from the sensor array system at two working temperatures, as the explosive gases show different sensitivity to the three sensors. The least squares method was employed for solving the simultaneous equations and quantifying the concentrations of the three components. The detection limits (3σ) of propane, n‐butane and iso‐butane on SrCO3, γ‐Al2O3 and BaCO3 sensors are 50, 40 and 20 ppm, 80, 60 and 40 ppm, and 20, 10 and 5 ppm, respectively. The concentrations of two artificial samples containing the tertiary mixture were analysed with satisfactory results. Copyright © 2005 John Wiley & Sons, Ltd.
Synthesis of Yb3+/Er3+ co‐dopants sodium yttrium fluoride up‐conversion fluorescence materials
Authors: Huang Minwen , Meng Fanyi 
Published: August 2005

AbstractYb3+/Er3+ co‐dopants sodium yttrium fluoride micro‐powders were synthesized by a combustion method and the luminescence properties investigated. The results indicated that the up‐conversion material synthesized by this method has high up‐conversion efficiency and the fluorescence spectrum peak was sharp. Copyright © 2005 John Wiley & Sons, Ltd.
Oxygen profiles and biomass distribution in biopellets of Aspergillus niger
Authors: Hille A. , Neu T.R. , Hempel D.C. , Horn H. 
Published: September 2005

AbstractMorphology of fungal pellets has a significant influence on mass transfer and turnover processes in submerged cultures. There are many reports in literature that biomass is not distributed homogeneously over the pellet radius, yet quantitative data is rare. This study presents a method for the quantification of fungal pellet structure (Aspergillus niger). Confocal laser scanning microscopy (CLSM) is used in combination with image analysis freeware (Image J). Hyphal distribution is resolved spatially in radial direction. Quantitative morphological parameters are derived from digital images especially from the peripheral regions of the pellet that are not oxygen limited. This morphological information is combined with data of microelectrode measurements in the same pellets. Results show that the morphological parameters obtained can describe the impact of pellet structure on oxygen gradients much better than average biomass density. It is concluded that CLSM and image analysis are powerful tools not only to generate valuable data for quantitative description of pellet morphology. In addition, this data may be used in mathematical models to improve predictions of mass transfer and substrate conversion in mycelial aggregates. © 2005 Wiley Periodicals, Inc.
Rapid separation and determination of aconitine alkaloids in traditional Chinese herbs by capillary electrophoresis using 1‐butyl‐3‐methylimidazoium‐based ionic liquid as running electrolyte
Authors: Qi Shengda , Cui Shuya , Cheng Yuqiao , Chen Xingguo , Hu Zhide 
Published: September 2005

AbstractA novel and very simple capillary electrophoretic method for analyzing aconitine components in Aconitum plants was developed using 1‐butyl‐3‐methylimidazoium tetrafluoroborate (1B‐3MI‐TFB)‐based ionic liquid as running electrolyte solution for the first time. The optimum conditions were 35 mM 1B‐3MI‐TFB solution (pH 8.50) and 15 kV applied voltage. The detection was performed at 254 nm. Aconitine, meaconitine and hypaconitine in Aconitum plants were separated and identified within 5 min. The recoveries were 91.0–103.0% for hypaconitine, 92.8–96.2% for aconitine and 96.0–106.6% for mesaconitine, respectively. Compared with other methods, the analytical time was decreased 4–8‐fold and the effect of Joule heating was weaker because the current was smaller. Copyright © 2005 John Wiley & Sons, Ltd.
A review of chromatographic methods for the assessment of phospholipids in biological samples
Authors: Peterson Brianna L. , Cummings Brian S. 
Published: September 2005

AbstractPhospholipids are important constituents of all living cell membranes. Lipidomics is a rapidly growing field that provides insight as to how specific phospholipids play roles in normal physiological and disease states. There are many analytical methods available for the qualitative and quantitative determination of phospholipids. This review provides a summary of the methods that were historically used such as thin layer chromatography, gas chromatography and high‐performance liquid chromatography. In addition, an introduction to applications of interfacing these traditional chromatographic techniques with mass spectrometry is provided. Copyright © 2005 John Wiley & Sons, Ltd.
Pseudoazurin–Nitrite Reductase Interactions
Authors: Impagliazzo Antonietta , Krippahl Ludwig , Ubbink Marcellus 
Published: September 2005

AbstractThe nitrite reductase‐binding site on pseudoazurin has been determined by using NMR chemical‐shift perturbations. It comprises residues in the hydrophobic patch surrounding the exposed copper ligand His81 as well as several positively charged residues. The binding site is similar for both redox states of pseudoazurin, despite differences in the binding mode. The results suggest that pseudoazurin binds in a well‐defined orientation. Docking simulations provide a putative structure of the complex with a binding site on nitrite reductase that has several hydrophobic and polar residues as well as a ridge of negatively charged side chains and a copper‐to‐copper distance of 14 Å.
Porphyrin‐Functionalized Dendrimers: Synthesis and Application as Recyclable Photocatalysts in a Nanofiltration Membrane Reactor
Authors: Chavan Suhas A. , Maes Wouter , Gevers Lieven E. M. , Wahlen Joos , Vankelecom Ivo F. J. , Jacobs Pierre A. , Dehaen Wim , De Vos Dirk E. 
Published: August 2005

AbstractThe convergent synthesis of a series of porphyrin‐functionalized pyrimidine dendrimers has been accomplished by a procedure involving the nucleophilic aromatic substitution (NAS) as a key reaction step. The resulting dendritic porphyrin catalysts show high activity in the light‐induced generation of singlet oxygen (1O2) from ground‐state oxygen. These materials are synthetically useful photosensitizers for the oxidation of various olefinic compounds to the corresponding allylic hydroperoxides. Catalytic activities and regio‐ and stereoselectivities of the dendritic photosensitizers are comparable to those observed for mononuclear porphyrin catalysts. Recycling of the dendrimer‐enlarged homogeneous photocatalysts was possible by solvent‐resistant nanofiltration (SRNF) by using an oxidatively stable membrane consisting of a polysiloxane polymer and ultrastable Y zeolite as inorganic filler. Moreover, this membrane technology provides a safe way to isolate the hydroperoxide products under very mild conditions. The membrane showed high retention for the macromolecular catalysts, even in chlorinated solvents, but some oxidative degradation of the porphyrin units of the dendrimer was observed over multiple catalytic runs.