bluuebunny/crossref_metadata_2025_split huggingface dataset:
DNA Binding by a New Metallointercalator that Contains a Proflavine Group Bearing a Hanging Chelating Unit
Authors: Bazzicalupi Carla , Bencini Andrea , Bianchi Antonio , Biver Tarita , Boggioni Alessia , Bonacchi Sara , Danesi Andrea , Giorgi Claudia , Gratteri Paola , Ingraín Antonio Marchal , Secco Fernando , Sissi Claudia , Valtancoli Barbara , Venturini Marcella 
Published: September 2007

AbstractThe new bifunctional molecule 3,6‐diamine‐9‐[6,6‐bis(2‐aminoethyl)‐1,6‐diaminohexyl]acridine (D), which is characterised by both an aromatic moiety and a separate metal‐complexing polyamine centre, has been synthesised. The characteristics of D and its ZnII complex ([ZnD]) (protonation and metal‐complexing constants, optical properties and self‐aggregation phenomena) have been analysed by means of NMR spectroscopy, potentiometric, spectrophotometric and spectrofluorimetric techniques. The equilibria and kinetics of the binding process of D and [ZnD] to calf thymus DNA have been investigated at I=0.11 M (NaCl) and 298.1 K by using spectroscopic methods and the stopped‐flow technique. Static measurements show biphasic behaviour for both D–DNA and [ZnD]–DNA systems; this reveals the occurrence of two different binding processes depending on the polymer‐to‐dye molar ratio (P/D). The binding mode that occurs at low P/D values is interpreted in terms of external binding with a notable contribution from the polyamine residue. The binding mode at high P/D values corresponds to intercalation of the proflavine residue. Stopped‐flow, circular dichroism and supercoiled‐DNA unwinding experiments corroborate the proposed mechanism. Molecular‐modelling studies support the intercalative process and evidence the influence of NH+⋅⋅⋅O interactions between the protonated acridine nitrogen atom and the oxygen atoms of the polyanion; these interactions play a key role in determining the conformation of DNA adducts.
Synthesis and Structure of Novel Sugar‐Substituted Bipyridine Complexes of Rhenium and 99m‐Technetium
Authors: Gottschaldt Michael , Koth Daniel , Müller Dirk , Klette Ingo , Rau Sven , Görls Helmar , Schäfer Bernhard , Baum Richard P. , Yano Shigenobu 
Published: September 2007

AbstractNovel ligands have been obtained from the reaction of 4,4′‐dibromomethyl‐2,2′‐bipyridine with 2,3,4,6‐tetra‐O‐acetyl‐β‐D‐glucopyranosylthiol, 2,3,4,6‐tetra‐O‐acetyl‐β‐D‐galactopyranosylthiol or 2,3,4,6‐tetra‐O‐acetyl‐α‐D‐thioacetylmannopyranoside in which the sugar residues are thioglycosidically linked to the bipyridine in the 4,4′‐position. Cleavage of the acetyl groups affords hydrophilic symmetric ligands with free hydroxyl groups. Reaction of the new glycoconjugated ligands (L) with [Re(CO)5Cl] yields fluorescent complexes of general formula [Re(L)(CO)3Cl], which were characterised by mass spectrometry, elemental analysis and 1H and 13C NMR, IR, UV/Vis and fluorescence spectroscopy. These complexes exhibit excellent solubility and stability in organic solvents or water, depending on the residues of the sugar. One complex, namely tricarbonyl‐4,4′‐bis[(2,3,4,6‐tetra‐O‐acetyl‐β‐D‐glycopyranosyl)thiomethyl]‐2,2′‐bipyridinerheniumtricarbonylo chloride, has been characterised by X‐ray crystallography. A non‐symmetric structure of the complexes could be assigned. Radiolabelling of the unprotected ligands with [99mTc(H2O)3(CO)3]+ affords the corresponding water‐soluble technetium complexes (in quantitative yields), which were characterised by their HPLC radiation traces. The formed complexes are stable for several hours in the presence of histidine but show partial ligand‐exchange after one day.
Evidence for the Intermediacy of Wheland–Meisenheimer Complexes in SEAr Reactions of Aminothiazoles with 4,6‐Dinitrobenzofuroxan
Authors: Boga Carla , Del Vecchio Erminia , Forlani Luciano , Goumont Régis , Terrier François , Tozzi Silvia 
Published: September 2007

AbstractReactions of DNBF with a series of 2‐aminothiazoles (1 a–f) to afford thermodynamically stable C‐bonded σ‐adducts have been investigated in acetonitrile. A most significant finding emerged on recording NMR spectra immediately after mixing of equimolar amounts of DNBF and the unsubstituted 2‐aminothiazole (1 a) in Me2SO: namely, that the formation of 9 a is preceded by that of a short‐lived intermediate species X. From the 1H NMR parameters characterizing this intermediate, as well as the dependence of its lifetime on the experimental conditions—the presence of excess DNBF over 1 a increases the lifetime of X while an excess of base (1 a) accelerates its conversion into 9 a—it is convincingly demonstrated that the structure of X combines the presence of a positively charged Wheland complex moiety (with regard to the thiazole ring) with that of a negatively charged Meisenheimer complex moiety (with regard to the benzofuroxan system). So far, only one intermediate of this type (noted WM) has been successfully characterized, in the reactions of DNBF with 1,3,5‐tris(N,N‐dialkylamino)benzenes. Among the key features supporting the intermediacy of X along the reaction coordinate leading to 9 a is the fact that the reactions of DNBF with 1 a in the presence of an alcohol (MeOH, EtOH, nPrOH) produce new adducts arising from the addition of an alcohol molecule to the thiazole moiety of WM‐1 a. Reflecting the presence of three chiral centres, these species are formed as mixtures of several diastereomers that could all be characterized in their racemic forms in ethanol. These findings generalize the previous report on the formation of Wheland–Meisenheimer carbon–carbon complexes in homocyclic series.
The Isolation of Basic Proteins by Solid‐Phase Extraction with Multiwalled Carbon Nanotubes
Authors: Du Zhuo , Yu Yong‐Liang , Chen Xu‐Wei , Wang Jian‐Hua 
Published: September 2007

AbstractMultiwalled carbon nanotubes (MWCNTs) have been employed for the first time as sorbents for the isolation of basic proteins from other protein species in biological sample matrices by solid‐phase extraction (SPE). A microcolumn packed with MWCNTs was incorporated after appropriate pretreatment into a sequential injection system, which facilitates online selective sorption of basic protein species (hemoglobin and cytochrome c in this particular case). The retained protein species were afterwards separated from each other by sequential elution from the microcolumn through the employment of appropriate eluents. A 0.025 mol L−1 phosphate buffer solution of pH 8.0 facilitated the efficient collection of hemoglobin, while a 0.5 mol L−1 NaCl solution ensured the quantitative recovery of the retained cytochrome c. With a sample loading volume of 2.0 mL, enrichment factors of 11 and 15 were derived for hemoglobin and cytochrome c, along with retention efficiencies of 100 % for both species and recovery rates of 98 and 90 %, respectively. A sampling frequency of 8 h−1 was achieved, and the precisions were 3.0 % and 0.8 % (RSD) for hemoglobin and cytochrome c at a concentration of 5.0 μg mL−1. The practical applicability of this system was demonstrated by processing of human whole blood for isolation of hemoglobin, and satisfactory results were obtained by assay with SDS‐PAGE.
Formation of ZSM‐22 Zeolite Catalytic Particles by Fusion of Elementary Nanorods
Authors: Hayasaka Kazuaki , Liang Duoduo , Huybrechts Ward , De Waele Bart R. , Houthoofd Kristof J. , Eloy Pierre , Gaigneaux Eric M. , van Tendeloo Gustaaf , Thybaut Joris W. , Marin Guy B. , Denayer Joeri F. M. , Baron Gino V. , Jacobs Pierre A. , Kirschhock Christine E. A. , Martens Johan A. 
Published: September 2007

AbstractAn ZSM‐22 aluminosilicate zeolite was synthesized using the hydrothermal gel method at 150 °C. Products obtained after different synthesis times were characterized using various techniques and catalytic testing. Massive formation of ZSM‐22 nanocrystals occurs after only a short synthesis time, appearing as isolated rods with a cross section of 12±4 nm. Nanorods have aluminum enriched at their external surface. Later in the crystallization process nanorods align and fuse sideways, whereby the external surface is systematically converted into an internal micropore surface. The formation of aluminum bearing micropores by the joining of nanorod surfaces is responsible for the enhanced catalytic activity. For this, the zeolite synthesis of nanoscale crystallites is ineffective for enhancing catalytic activity.
L'ingénierie des connaissances pour la modélisation du raisonnement dans une tâche de diagnostic: Application à la recherche et sauvetage
Authors: Schvartz Stéphane , Abi‐Zeid Irène , Tourigny Nicole 
Published: September 2007

AbstractThis paper pertains to the application of knowledge engineering methods to aeronautical search and rescue in Canada. We modelled at the knowledge level the reasoning process of a search mission coordinator when conducting a diagnosis task to determine the routes likely followed by a missing aircraft overland. Knowledge engineering allowed us to develop a reasoning model based on documents and on interviews with domain experts. Our study was conducted in the CommonKADS knowledge modelling framework. The proposed model was validated by domain experts and implemented in a rule‐based system prototype. Copyright © 2007 ASAC. Published by John Wiley & Sons, Ltd.
Two New Nitronyl Nitroxide Radicals and Their Complexes with M(hfac)2 [M=Co(II), Ni(II), Mn(II)]: Syntheses, Crystal Structures, and Magnetic Characterizations
Authors: Yu Yan‐Xin , Hu Huai‐Ming , Zhang De‐Qing , Wang Zhi‐Yong , Zhu Dao‐Ben 
Published: September 2007

AbstractTwo new nitronyl nitroxides with amido units L1 and L2 were synthesized and characterized. Reactions of L1 and L2 with M(hfac)2 [hfachexafluoroacetylacetonate, MCo(II), Ni(II), Mn(II)] afforded five hetero‐spin complexes L1Co(hfac)2, L1Ni(hfac)2, L2Co(hfac)2, L2Ni(hfac)2 and L2Mn(hfac)2. The crystal structures and magnetic characterizations of L1, L2 and their metal complexes LM(hfac)2 were described and discussed. Crystal structural analysis shows that both the carbonyl oxygen and the nitroxide oxygen are coordinated to the metal ions. Strong antiferromagetic coupling between the nitronyl nitroxides and metal ions were observed for all the five LM(hfac)2 complexes.
Studies on the Interaction of Dinitratobis(phen) Cadmium Complex with DNA
Authors: Yuan Cai‐Xia , Wu Yan‐Bo , Wei Yi‐Bin , Yang Pin , Zhu Miao‐Li 
Published: September 2007

AbstractDNA‐binding properties of the dinitratobis(phen) cadmium complex [Cd(phen)2(NO3)2] (where phen1,10‐phenanthroline) have been investigated with absorption titration, fluorescence spectroscopy, viscosity measurement, molecular modeling and density functional theory (DFT) calculations. The results indictate DNA‐binding mode of the complex to be weak groove binding rather than partial intercalative interaction expected of the extended planar aromatic phen ring. In addition, the DNA cleavage study was carried out by gel electrophoresis experiment. The results showed that the complex both hardly cleaves pBR322 DNA in the absence and present ascorbate. So it is suggested that the formation of cadmium complex can decrease cadmium toxicity to some extents.
Effects of Ti and Co on the Electrochemical Characteristics of MgNi‐Based Alloy Electrodes
Authors: Feng Yan , Jiao Li‐Fang , Yuan Hua‐Tang , Zhao Ming 
Published: September 2007

Abstract Mg‐based hydrogen storage alloys MgNi, Mg0.9Ti0.1Ni and Mg0.9Ti0.1Ni0.9Co0.1 were successfully prepared by means of mechanical alloying (MA). The structure and the electrochemical characteristics of these Mg‐based materials were also studied. The results of X‐ray diffraction (XRD) and scanning electron microscopy (SEM) show that the main phases of the alloys exhibit amorphous structures, and trace of Ni co‐exists. The charge‐discharge cycle tests indicate these alloys have good electrochemical active characteristics. And the cycle stability of Ti and Co doped alloy was better than that of MgNi alloy. After 50 cycle charge‐discharge, the discharge capacity of the Mg0.9Ti0.1Ni0.9Co0.1 alloy was much better than that of MgNi and Mg0.9Ti0.1Ni alloys. The discharge capacity of Mg0.9Ti0.1Ni0.9Co0.1 was 102.8% higher than that of MgNi alloy, and 45.49% higher than that of the Mg0.9Ti0.1Ni alloy. During the process of charge‐discharge cycle test, the main reason for the electrode capacity fading is the corrosion of Mg to Mg(OH)2 on the surface of alloys. The Tafel polarization test indicates Ti and Co improve the anticorrosion in an alkaline solution. The EIS results suggest that proper amount of Ti and Co doping improve the electrochemical catalytical activity on the Mg‐based alloy surface significantly.
A New Nanogold‐Labeled Immunoresonance Scattering Spectral Probe for Determination of Trace IgG
Authors: Jiang Zhi‐Liang , Li Yan , Sun Shuang‐Jiao , Chen Bing 
Published: September 2007

AbstractA kind of 9 nm gold nanoparticles was prepared with the trisodium citrate and used to label goat anti‐human IgG to obtain an IgG immunoresonance scattering spectral probe. In pH 5.8 buffer solution and in the presence of polyethylene glycol (PEG), the immune reaction between gold‐labeled goat anti‐human IgG and IgG took place, and the resonance scattering intensity at 580 nm (I580 nm) was enhanced greatly. The enhanced intensity ΔIRS is proportional to the IgG concentration from 1.3 to 1.5×103 ng·mL−1, with a detection limit of 0.78 ng·mL−1. This assay showed high sensitivity and good selectivity for quantitative determination of IgG in human serum, with satisfactory results.
Extractive Spectrophotometric Determination of Fluconazole by Ion‐pair Complex Formation with Bromocresol Green
Authors: Jalali Fahimeh , Rajabi Mohammad J. 
Published: September 2007

AbstractAn extraction‐spectrophotometric method for the determination of trace amounts of fluconazole was described. Fluconazole was effectively extracted as a 1:1 ion‐pair complex with bromocresole green (BCG) at pH 3.0 into chloroform, followed by spectrophotometric determination at 420 nm. Beer′s law was obeyed over the range of 4–50 µg·mL−1 of fluconazole with a detection limit of 3.7 µg·mL−1. The method is simple, rapid and sensitive. The procedure was applied to the determination of fluconazole in pharmaceutical preparations as well as its recovery from a blood serum sample.
Reaction of Alkanesulfinyl Chloride with Grignard Reagents: a Convenient Synthesis of Alkyl Sulfoxides
Authors: Li Xiao‐Bo , Liu Jin‐Tao 
Published: September 2007

AbstractAlkyl sulfoxides were synthesized in good yields from the reaction of alkanesulfinyl chloride with Grignard reagents in the presence of zinc chloride.
Ligand Bridged and Bis‐ligand Coordinated Titanium Complexes: Synthesis, Structure and Relevance to Phenylacetylene Hydroanilination Catalysis
Authors: Han Xiao‐Yu , Li Ya‐Hong , Wei Hua , Zhang Yong 
Published: September 2007

AbstractTwo ligand bridged binuclear titanium complexes Ti2(bppda)3(NMe2)2·3THF (1) and Ti2(bppda)3(NEt2)2·3THF (2) and one bis‐ligand coordinated mononuclear complex Ti(bppda)2 (3) (ligand: H2bppdaN,N′‐Bis(2‐pyrrylmeth‐ylidene)‐1,2‐phenylenediamine) were synthesized by adjusting the ratio of the starting materials and the reaction speed. The complexes were fully characterized with NMR, elemental analysis and X‐ray crystal diffraction. The catalytic activity of the complex 1 to phenylacetylene hydroanilination reaction was also investigated.
Organogels Derived from Potassium 8‐Nitroquinolinecarboxylate
Authors: Hu Hai‐Yu , Yang Yong , Xiang Jun‐Feng , Chen Chuan‐Feng 
Published: September 2007

AbstractA new class of organogels derived from potassium 8‐nitroquinolinecarboxylate was selectively formed inTHF/MeOH (V:V=1:1), and their superstructures were characterized by atomic force microscopy, scanning electron microscopy and transmission electron microscopy.
Characterization of a multiple epigenetic marker panel for lung cancer detection and risk assessment in plasma
Authors: Hsu Han‐Shui , Chen Tsz‐Pei , Hung Chein‐Hui , Wen Chiao‐Kai , Lin Rou‐Kai , Lee Hui‐Chen , Wang Yi‐Ching 
Published: September 2007

AbstractBACKGROUND.Methylation patterns may be useful biomarkers of cancer detection and risk assessment.METHODS.The methylation status of 6 genes, including a candidate tumor suppressor gene (BLU), the cadherin 13 gene (CDH13), the fragile histidine triad gene (FHIT), the cell cycle control gene p16, the retinoic acid receptor β gene (RARβ), and the Ras association domain family 1 gene (RASSF1A), was examined in plasma samples, corresponding tumor tissues, and normal lung tissues from a group of 63 patients with lung cancer and in plasma samples from 36 cancer‐free individuals. The detection rate of the p16 gene was validated in a test group of 20 patients with lung cancer.RESULTS.The concordance of methylation in tumor tissues and plasma samples was 86%, 87%, 80%, 75%, 76%, and 84% for the BLU, CDH13, FHIT, p16, RARβ, and RASSF1A genes, respectively. The test group showed a similar concordance for p16 methylation detection. Multiple logistic regression analysis showed that the odds ratio for having lung cancer was 10.204 for individuals with p16 methylation (P = .013) and 9.952 for individuals with RASSFIA methylation (P = .019). After several trial tests, the authors established that methylation for ≥2 of the 6 markers met the criterion for an elevated risk of cancer. Comparisons yielded a sensitivity of 73%, a specificity of 82%, and a concordance of 75% between the methylation patterns in tumor tissues and in corresponding plasma samples. The detection rate was relatively high in cigarette smokers with advanced squamous cell lung cancer.CONCLUSIONS.The current results indicated that multiple epigenetic markers in the plasma, especially the p16 and RASSF1A genes, can be used for lung cancer detection. This methylation marker panel should improve the detection of cancer or the risk assessment for lung cancer in combination with conventional diagnostic tools. Cancer 2007. © 2007 American Cancer Society.
Electromechanical analysis of electrostatic nano‐actuators using the differential quadrature method
Authors: Hsu Ming‐Hung 
Published: September 2007

AbstractThe nonlinear analysis of nanoelectromechanical systems using the differential quadrature model is investigated. The differential quadrature method is applied to overcome the difficulty of determining the nonlinear equation of motion. The characteristics of various combinations of curved electrodes and cantilever beams are considered to optimize the design. Various nano‐actuators, such as the cantilever beam actuator, are derived and simulated to examine the feasibility of applying the differential quadrature method to the nonlinear deflection in solving the nano‐actuator problem. The effects of the electrode shapes, the lengths of the actuators, and the moments of inertia of the actuators on the pull‐in behavior of the cantilever actuators in electrostatic nanoelectromechanical systems are investigated. The differential quadrature approach is used to generate the electrostatic field equations in matrix form. Copyright © 2007 John Wiley & Sons, Ltd.
An efficient graph‐theoretical force method for three‐dimensional finite element analysis
Authors: Kaveh A. , Koohestani K. 
Published: September 2007

AbstractIn this paper an efficient method is developed for the formation of null bases of finite element models (FEMs) composed of tetrahedron elements, corresponding to highly sparse and banded flexibility matrices. This is achieved by associating special graphs with the FEM and selecting appropriate subgraphs and forming the self‐stress systems on these subgraphs. The efficiency of the present method is illustrated through two examples. Copyright © 2007 John Wiley & Sons, Ltd.
Development of New Glass Composite Membranes and their Properties for Low Temperature H2/O2 Fuel Cells
Authors: Uma T. , Nogami M. 
Published: September 2007

AbstractA new glass electrolyte formed by constant amounts of titanium oxide (TiO2) and various amount of phosphotungstic acid (PWA) doped P2O5–SiO2 is prepared using the sol‐gel process. The structural formation is confirmed by Fourier infrared spectroscopy (FTIR) and from thermogravimetric and differential thermal analysis (TG/DTA) measurements, the glasses display good thermal stability. Further characterisation is undertaken by N2 adsorption/desorption measurements, proton conductivity and hydrogen permeability analyses and a H2/O2 fuel cell test is also performed. The glass materials with large pores and specific surface area are suitable for use as the electrolyte in H2/O2 fuel cells. The effect of TiO2 processing with constant amount of PWA in phosphosilicate glasses, is investigated and discussed. The hydrogen permeability is 1.57×10−11 mol cm−1 s−1 Pa−1 at 110 °C for 0.8 mm thick glass; a power density of 46.3 mW cm−2 at 125 mA cm−2 and a current density of 175 mA cm−2 is obtained (T=28 °C, relative humidity).
First Kinetic Determination of Partition Coefficients for Organic Compounds between the Three Microenvironments of AOT‐Based Microemulsions
Authors: García‐Río Luis , Méndez María 
Published: September 2007

AbstractKinetic data for the hydrolysis of N‐picolinoylimidazole (I) and 2,4‐dinitrophenylpicolinate (II) in AOT [bis(2‐ethylhexyl) sodium sulfosuccinate] microemulsions are used to determine for the first time the two partition constants for each substrate (i.e. Kwi and Koi, corresponding to the incorporation of substrate molecules from water microdroplets and the continuous medium, respectively, into the interface). Application of the pseudophase formalism to the partition constants allowed the rate constant in each phase to be determined. The rate of hydrolysis of II increased with decreasing polarity of the medium; as a result, the hydrolysis reaction took place largely at the interface. On the other hand, the rate of hydrolysis of acylimidazole I decreased with decreasing polarity, possibly as a result of changes in the resonance structures of the reagent causing the hydrolysis process to occur preferentially in water microdroplets.
Behavior of phosphorus impurities during Czochralski growth of high‐purity germanium single crystals
Authors: Gusev A. V. , Gavva V. A. 
Published: September 2007

AbstractThe effect of evaporation of phosphorus impurities from the melt is investigated as well as the contaminating effect of quartz glass crucibles on residual content and distribution of this impurities by length of high‐purity germanium single crystals. The residual content of phosphorus impurities is mainly influenced by the contaminating effect of crucible material and its distribution by length of crystals is described by the model accounting for the impurities income from crucible material. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nucleation kinetics, growth, solubility and dielectric studies of L‐proline cadmium chloride monohydrate semi organic nonlinear optical single crystal
Authors: Kandasamy A. , Mohan R. , Lydia Caroline M. , Vasudevan S. 
Published: September 2007

AbstractNucleation parameters such as solubility, induction period, interfacial energy and metastable zone width have been investigated for the aqueous solution growth of a semi‐organic nonlinear optical (NLO) material of L‐Proline cadmium chloride monohydrate (L‐PCCM) single crystal. Metastable zone width and induction period values were determined experimentally in order to optimize the growth parameters. The grown crystals are transparent (dimensions: 16 x 8 x 5 mm3) and characterized by powder X‐Ray Diffraction and dielectric studies. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)