bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anti‐oxidant and pro‐oxidant behaviour of bucillamine
Authors: Kładna Aleksandra , Aboul‐Enein Hassan Y. , Kruk Irena , Michalska Teresa , Lichszteld Krzysztof 
Published: January 2006

AbstractBucillamine (BUC) is used clinically for the treatment of rheumatoid arthritis. Some of the pharmacological action of BUC has been reported as being dependent on the production of reactive oxygen species (ROS). In this paper the reactivity of BUC with superoxide anion radical (O2•−) generated from potassium superoxide/18‐crown‐6 ether dissolved in DMSO, hydroxyl radical (HO•) produced in the Cu2+–H2O2 reaction, peroxyl radical (ROO•) from 2,2′‐azobis (2‐amidino‐propane) dichloride decomposition, and singlet oxygen (1O2) from a mixture of alkaline aqueous H2O2 and acetonitrile, have been investigated. Chemiluminescence, fluorescence, electron paramagnetic resonance (EPR) spin‐trapping techniques and the deoxyribose and oxygen radical absorbance capacity towards ROO• (ORACROO) assays were used to elucidate the anti‐ and pro‐oxidative behaviours of BUC towards ROS. The results indicated that BUC efficiently inhibited chemiluminescence from the O2•−‐generating system at relatively high concentrations (0.5–2 mmol/L); however, at lower concentrations (<0.5 mmol/L) the drug enhanced light emission. The behaviour of BUC was correlated with a capacity to decrease the chemiluminescence signal from the Cu2+–H2O2 system; scavenging HO• was effective only at high concentrations (1–2 mmol/L) of the drug. Bucillamine also prevented deoxyribose degradation induced by HO• in a dose‐dependent manner, reaching maximal inhibition (24.5%) at a relative high concentration (1.54 mmol/L). Moreover, BUC reacts with ROO•; the relative ORACROO was found to be 0.34 µmol/L Trolox equivalents/µmol sample. The drug showed quenching of 1O2‐dependent 2,2,6,6‐tetramethylpiperidine‐N‐oxide radical formation from 2,2,6,6‐tetramethyl‐piperidine (e.g. 90% inhibition was found at 1 mmol/L concentration). The results showed that BUC may directly scavenge ROS or inhibit reactions generating them. However, the drug may have pro‐oxidant activity under some reaction conditions. Copyright © 2006 John Wiley & Sons, Ltd.
Release of bovine serum albumin from a hydrogel‐cored biodegradable polymer fiber
Authors: Crow B. B. , Nelson K. D. 
Published: January 2006

AbstractWe have developed a novel biodegradable, polymeric fiber construct that is coextruded using a wet‐spinning process into a core‐sheath format with a polysaccharide pre‐hydrogel solution as the core fluid and poly(L‐lactic acid) (PLLA) as the sheath. The biodegradable, biocompatible fibers were extruded from polymeric emulsions comprised of solutions of various molecular weights of PLLA dissolved in chloroform and containing dispersed, protein‐free aqueous phases comprising up to 10% of the emulsion volume. Biologically sensitive agents can be loaded via a dispersed aqueous phase in the polymer, and/or directly into the polysaccharide. We show that this core‐sheath fiber format will load a model protein that can be delivered for extended periods in vitro. Bovine serum albumin (BSA) was loaded into the fiber core as a model protein. We have shown that the greater the volume of the protein‐free aqueous phase dispersed into the polymeric continuous‐phase emulsion, the greater the total release of BSA encapsulated by a core gel comprised of 1% sodium alginate solution. We conclude this fiber format provides a promising vehicle for in vivo delivery of biological molecules. Its biocompatibility and biodegradability also allow for its use as a possible substrate for tissue engineering applications. © 2006 Wiley Periodicals, Inc. Biopolymers 81: 419–427, 2006This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Effect of the Solvent on the Conformation of a Depsipeptide: NMR‐Derived Solution Structure of Hormaomycin in DMSO from Residual Dipolar Couplings in a Novel DMSO‐Compatible Alignment Medium
Authors: Reinscheid Uwe M. , Farjon Jonathan , Radzom Markus , Haberz Peter , Zeeck Axel , Blackledge Martin , Griesinger Christian 
Published: January 2006

AbstractThe macrocyclic compound hormaomycin has been investigated by NMR spectroscopy and by restrained molecular‐dynamics simulations. Measurement of residual dipolar couplings induced by dissolving the depsipeptide in a polyacrylamide gel compatible with DMSO and their incorporation into the structure calculation of the title compound improved the precision of the family of structures. In DMSO the macrocyclic ring shows two β‐turns, whose positions in the sequence differ from those found in the CDCl3 solution structure and in the crystal structure obtained from hexylene glycol/H2O (50:50). The bulky side chain consisting of a 3‐(2‐nitrocyclopropyl)alanine and a chlorinated N‐hydroxypyrrole moiety is flexible in DMSO.
Identification of New Acceptor Specificities of Glycosyltransferase R with the Aid of Substrate Microarrays
Authors: Seibel Jürgen , Hellmuth Hendrik , Hofer Bernd , Kicinska Anna‐Maria , Schmalbruch Bodo 
Published: January 2006

AbstractFinding opportunities to construct sugar motifs and to transfer them to targets of biological relevance and rapid identification of glycosylation events are important goals for glycobiology and a field of increasing interest. Here we have applied an enzyme microarray screening system for the identification of new acceptor specificities of the glycosyltransferase R (GTFR) from Streptococcus oralis (E.C. 2.4.1.5), which was able to effect the synthesis of sugar motifs in short times and with low amounts of substrate. These observations resulted in the development of a convenient α‐glycosylation by the non‐Leloir glycosyltransferase GTFR, with sucrose as substrate and with different alcohols and amino acid derivatives as acceptors, for the synthesis of glycoethers and glycosylated amino acids not observed with the use of familiar GTFs with high sequence homology.
Effect of Alkali Metal Coordination on Gas‐Phase Chemistry of the Diphosphate Ion: The MH2P2O7− Ions
Authors: Pepi Federico , Ricci Andreina , Rosi Marzio , Di Stefano Marco 
Published: January 2006

AbstractSystematic experimental and theoretical studies on anionic phosphate species in the gas phase are almost nonexistent, even though they could provide a benchmark for enhanced comprehension of their liquid‐phase chemical behavior. Gaseous MH2P2O7− ions (M=Li, Na, K, Rb, Cs), obtained from electrospray ionization of solutions containing H4P2O7 and MOH or M salts as a source of M+ ions were structurally assayed by collisionally activated dissociation (CAD) mass spectrometry and theoretical calculations at the B3LYP/6‐31+G* level of theory. The joint application of mass spectrometric techniques and theoretical methods allowed the MH2P2O7− ions to be identified as having a structure in which the linear diphosphate anion is coordinated to the M+ ion (I) and provides information on gas‐phase isomerization processes in the [PO3⋅⋅⋅MH2PO4]− clusters II and the [P2O6⋅⋅⋅M⋅⋅⋅H2O]− clusters IV. Studies of gas‐phase reactivity by Fourier transform ion cyclotron resonance (FTICR) and triple quadrupole (TQ) mass spectrometry revealed that the MH2P2O7− ions react with selected nucleophiles by clustering, proton transfer and addition–elimination mechanisms. The influence of the coordination of alkali metal ions on the chemical behavior of pyrophosphate is discussed.
A Novel Method for Time‐Resolved Fluorimetric Determination and Imaging of the Activity of Peroxidase, and Its Application to an Enzyme‐Linked Immunosorbent Assay
Authors: Lin Zhihong , Wu Meng , Wolfbeis Otto S. , Schäferling Michael 
Published: January 2006

AbstractA new type of fluorescence assay for the determination of peroxidase (POx) activity is presented. The assay is based on the indication of the enzymatic consumption of H2O2(HP), using a fluorescent europium–tetracycline (Eu3TC) complex as indicator. On addition of HP, this complex forms a highly fluorescent adduct (Eu3TC–HP), which is decomposed in the presence of POx to form the weakly fluorescent europium–tetracycline (Eu3TC). Hence, the activity of the enzyme can be directly determined by means of the luminescent Eu3TC complex as indicator. The POx assay demonstrated herein was elaborated starting from a spectral characterization of the complex systems involved. Due to the long lifetime of lanthanide luminescence, both steady‐state and time‐resolved luminescence assays can easily be performed. The time‐resolved assay can quantify POx in the range from 4.0×10−5to 5.9×10−3U mL−1, with a limit of detection of 1.0×10−5U mL−1. The effects of POx inhibitors such as cyanide, hydroxylamine, and azide have also been studied. In addition, a time‐resolved fluorescent detection method for a POx‐based enzyme‐linked immunosorbent assay (ELISA) has been developed, which is demonstrated in a sandwich model assay with bovine IgG serving as analyte. Furthermore, a time‐resolved fluorescent imaging method is demonstrated that makes use of a straightforward imaging set‐up adjusted to the optical properties of the europium reagent.
Optical Processing with Photochromic Switches
Authors: Raymo Françisco M. , Tomasulo Massimiliano 
Published: January 2006

AbstractThe absorbance, fluorescence, and refractive index of a photochromic material can be modulated under the influence of optical stimulations. The reversible modification of these macroscopic properties is a result of photoinduced transformations at the molecular level. These processes can be exploited to mediate the interplay of optical signals and offer the opportunity to design and implement photonic devices for optical processing based on molecular components.
Synthesis of Fullerene Adducts with Terpyridyl‐ or Pyridylpyrrolidine Groups in trans‐1 Positions
Authors: Zhang Sheng , Lukoyanova Olena , Echegoyen Luis 
Published: January 2006

AbstractTwo C60 hexakis‐adducts (2 and 3) were synthesized by using a protection–deprotection strategy. The symmetric fullerene tetrakis‐adduct 8 was obtained by anthracene removal from the hexakis‐adduct 7. Reaction of 8 with terpyridylglycine or pyridylglycine afforded two hexakis‐adducts, 2 and 3. By using the retro‐cyclopropanation reaction, the four malonate addends located on the equatorial belt of the hexakis‐adducts were removed to afford two trans‐1 bis‐adducts, 4 and 5, with terpyridyl‐ or pyridylpyrrolidine groups. The structures of 2 and 3 were confirmed by matrix‐assisted laser desorption ionization time‐of‐flight (MALDI‐TOF) mass spectrometry, and 1H, 13C, and COSY NMR, and UV‐visible spectroscopy. The cyclic voltammograms of fullerene multiadducts 2, 3, and 9 show irreversible reductions. Self‐assembled monolayers (SAMs) of 1 and 3 were formed on gold surfaces through nitrogen adsorption. SAMs of 3 represent the first example of a fullerene hexakis‐adduct formed on gold surfaces through nitrogen adsorption. Controlled potential electrolyses (CPE) were conducted to prepare trans‐1 bis‐adducts 4 and 5 modified with terpyridyl and pyridyl groups.
Synthesis of Calix[4]arene Derivatives with NLO Properties
Authors: Bai Zhu , Zhang Chao‐Zhi , Lu Guo‐Yuan , Liu Fang 
Published: January 2006

AbstractThe new chromophore compounds with NLO properties were prepared by Knoevenagel condensation from formyl or diformyl calix[4]arene and isophorone derivatives in the presence of piperidine and acetic acid, respectively. In these chromophore calix[4]arenes, the ring locked trienes were employed as the conjugation bridge and electron acceptor in D‐π‐A units. The NMR spectra demonstrated that they existed in a cone conformation and consequently non‐conjugated D‐π‐A units could be oriented at nearly the same direction.
Reduction and Coupling Reaction of Carbonyl Compounds by Aluminum Powder and a Small Amount of Oxalic Acid in Water
Authors: Yuan Shi‐Zhen , Wang Zhi‐Yong , Li Zhen 
Published: January 2006

AbstractA convenient pinacol coupling of aromatic aldehydes and aryl methyl ketones has been achieved with high yields by aluminum powder in the presence of oxalic acid in water. However, the diastereoselectivities of pinacols were not satisfying, and most aliphatic aldehydes and diaryl ketones have been found to be unreactive under the same conditions.
Tin‐Indium Mediated and Microwave Assisted Propargylation of Aldehydes with Propargyl Bromide
Authors: Li Qian‐Rong , Gu Cheng‐Zhi , Yin Hao 
Published: January 2006

AbstractA rapid and regioselective preparation of homopropargyl alcohols was reported. In the presence of SnCl2‐C6H5Me3NBr and microwave irradiation, the mixture of tin‐indium and propargyl bromide reacted quickly with aldehydes in aqueous media to produce the homopropargyl alcohols exclusively in high yields. For benzaldehydes bearing different substituents, electronic effect of the substituents affected the reaction, the electron‐withdrawing groups promoting the reaction and the electron‐donating groups impeding the reaction. The reactions of benzaldehydes bearing an orthosubstituent group on the phenyl ring with propargyl bromide may yield a mixture of regioisomers (homopropargyl and homoallenyl alcohols) or a single homoallenic alcohol due to the steric effect.
Microbial Hydroxylation of Quinovic Acid Glycoside by Streptomyces griseus ACCT 13273
Authors: Cheng Zhi‐Hong , Yu Bo‐Yang , Guo Yin‐Long , Qiu Sheng‐Xiang 
Published: January 2006

AbstractMicrobial transformation of a triterpene glycoside, quinovic acid 3‐O‐β‐D‐quinovopyranoside by Streptomyces griseus ACCT 13273 was achieved with the aim of generating new bio‐active derivatives. Preparative‐scale biotransformation with standard two‐stage fermentation protocol afforded a new oxidized metabolite, as a result of the hydroxylation of the methyl group at C‐30, which was difficult to achieve by chemical means. The metabolite was elucidated based on extensive NMR and high‐resolution mass spectral analyses.
Mitoxantrone, carboplatin, cytosine arabinoside, and methylprednisolone followed by autologous peripheral blood stem cell transplantation
Authors: Sorá Federica , Piccirillo Nicola , Chiusolo Patrizia , Laurenti Luca , Marra Roberto , Bartolozzi Francesco , Leone Giuseppe , Sica Simona 
Published: January 2006

AbstractBACKGROUNDThe objective of the current study was to evaluate a salvage chemotherapy regimen consisting of mitoxantrone, carboplatin, cytosine arabinoside, and methylprednisolone (MiCMA) for the treatment of patients with primary refractory or recurrent non‐Hodgkin lymphoma (NHL).METHODSFrom September 1991 to August 2002, 94 consecutive patients ages 16–60 years who had either recurrent or refractory NHL (mainly diffuse large‐cell lymphomas) were treated on the MiCMA protocol. Patients had peripheral blood stem cells collected successfully for autologous stem cell transplantation after two or three cycles of MiCMA.RESULTSSixty‐four of 85 evaluable patients achieved a response to the MiCMA regimen: 24 patients (26%) achieved a complete response and 40 patients (44%) achieved a partial response, for a total response rate of 70%. Sixty‐two patients underwent autologous stem cell transplantation. After a median follow‐up of 58 months, 47 patients (55%) remained alive; among these patients, 32 were free of disease (37%). No toxic deaths related to MiCMA were observed. Three patients died of infectious complications after transplantation.CONCLUSIONSThe current results suggested that MiCMA chemotherapy is an effective therapeutic alternative salvage regimen for patients with primary refractory or recurrent NHL. Response rates, overall survival, and freedom from disease progression were found to be associated significantly with response to MiCMA. Peripheral blood stem cell transplantation was feasible in virtually all patients, and its outcome was influenced strongly by chemosensitivity. Cancer 2006. © 2006 American Cancer Society.
A new node organization mechanism of a campus Grid and performance analysis
Authors: Deng Zhiqun , Dai Guanzhong , Xie Ting , Zhou Daowu , Mu Dejun , Zhang Xinjia 
Published: January 2006

AbstractThis paper proposes a new node organization mechanism in the storage service provided by the Campus Grid Service Environment. The advantage of this architecture is its ability to aggregate nodes in the order of millions; the corresponding storage space aggregated can attain a petabyte level, which is a significant improvement in comparison with other campus Grids. Furthermore, this architecture is scalable and it can allow more nodes to join the storage pool to increase the storage space. The multilevel linked lists were first developed in order to organize the storage resources that are contributed by the nodes in the campus network. Subsequently, the algorithms were presented to analyze the mechanisms of the nodes: joining and leaving; storage resource scheduling and allocation; and unallocated storage space management. The performance of this system was investigated by employing a stochastic fluid model as the storage space changes with time as a result of the variation of the number of nodes. With this analytical model, the function between the storage allocation probability and the number of nodes was obtained. If more nodes join the campus Grid, the aggregated storage space will provide more available storage resources. If the storage resources allocation rate is less than the storage resources release rate, the available storage resources will increase and vice versa. Copyright © 2006 John Wiley & Sons, Ltd.
DartGrid: a semantic infrastructure for building database Grid applications
Authors: Chen Huajun , Wu Zhaohui , Mao Yuxin , Zheng Guozhou 
Published: January 2006

AbstractIn the presence of a Database Grid where a huge number of highly diverse, widely distributed, autonomously managed databases can be involved in a sharing cycle, database tools and middleware should be well suited for schema mediation and query processing in a semantically meaningful way. In this paper, an implemented system called DartGrid is presented. DartGrid is intended to provide a semantic infrastructure for building database grid applications. We explore the essential and fundamental roles played by Resource Description Framework (RDF) semantics for database grids and implement a set of semantically enabled tools and grid services such as semantic browser, semantic mapping tools, ontology service, semantic query service and semantic registration service. We propose an RDF‐View‐based approach for relational schema mediation and describe the view‐based semantic query rewriting algorithm implemented in DartGrid. DartGrid has been used to build a real database grid application for Traditional Chinese Medicine in China. Copyright © 2006 John Wiley & Sons, Ltd.
Growth and electrical properties of flash evaporated AgGaTe2 thin films
Authors: Patel B. H. , Patel S. S. 
Published: January 2006

AbstractThin films have been prepared by flash evaporation technique of a stoichiometric bulk of AgGaTe2 compound in vacuum and analysed using X‐ray diffraction, transmission electron microscopy, selected area diffraction and energy dispersive analysis of X‐rays. The effect of substrate temperature on the structural properties – grain size, film orientation, composition, and stoichiometry of the films have been studied. It was found that the polycrystalline, stoichiometric films of AgGaTe2 can be grown in the substrate temperature range of 473K < Ts < 573K. The influence of substrate temperature (Ts) on the electrical characteristics‐ Resistivity, Hall Mobility, Carrier concentration of AgGaTe2 thin films were studied. The electrical resistivity was found to decrease with increase in substrate temperature up to 573K and then increases. The variation of activation energy of AgGaTe2 thin films were also investigated. The implications are discussed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth and characterization of cadmium magnesium tetra thiocyanate crystals
Authors: Gunasekaran S. , Ponnusamy S. 
Published: January 2006

AbstractCadmium Magnesium Tetra Thiocyanate, CdMg(SCN)4, [CMTC] belongs to bimetallic thiocyanate complexes. CMTC crystals has been grown by solution growth technique at room temperature. The morphologies of the grown crystals are identified by single crystal analysis. Also the Powder X‐ray Diffractogram of the crystal has been recorded and the various planes of reflection are identified. The title compound crystallizes under triclinic structure with lattice parameters a = 10.0976 Å, b = 7.5015 Å, c = 5.7720 Å and β = 90.2135°. The presence of magnesium and cadmium in the grown crystals were confirmed through Atomic Absorption Spectroscopy. The grown crystals are analysed qualitatively by Fourier Transform Infrared (FTIR) and Fourier Transform Raman spectral measurements. The transmittance spectrum of the crystal in the UV‐Visible region has been recorded and analysed. The dielectric measurements for the crystals were carried out in the microwave region. The thermal stabilities of the crystals were studied by using different thermal analyses like Thermo Gravimetric Analysis (TGA), Differential Thermal Analysis (DTA) and Differential Scanning Calorimetry (DSC). (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigation on defects in Lu2SiO5:Ce crystals grown by Czochralski method
Authors: Ren Guohao , Qin Laishun , Li Huanying , Lu Sheng 
Published: January 2006

AbstractCerium‐doped lutetium oxyorthosilicate crystals (Lu2SiO5:Ce) with dimension of ∅︁50 × 60 mm were grown by Czochralski method from an inductively heated iridium crucible. The vaporized substance during growth was examined with XRD and proved to be SiO2. The vertical and the screw strips existing on the surface of the boule were observed with optical microscope and tested with electron microprobe. They are confirmed to be iridium from the crucible and harmful to the crystal growth. The cleavage orientation of LSO was proved to be (110) and it is one of factors to cause crystal cracking. The scattering particles in LSO crystals are analyzed to be mainly composed of Lu2O3 inclusions. Two possible origins on these inclusions are proposed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis and X‐ray structure of two conformational isomers of [Zn(medpt)(SCN)2], medpt = bis (3 – aminopropyl)methylamine
Authors: Guha S. , Mukherjee A. K. , Maji T. K. , Ray Chaudhuri N. 
Published: January 2006

AbstractTwo conformational isomers of [Zn (medpt)(NCS)2], medpt=bis(3‐aminopropyl) methylamine, (1) and (2) have been synthesised and the crystal structures are determined using single crystal X‐ray diffraction. The structures of the complexes have been solved by Patterson method and refined by full‐matrix least‐ squares techniques to R1 = 0.0524 for (1) and R1 = 0.0506 for (2), respectively. The geometry around the Zn(II) centre in both isomers is distorted trigonal bipyramidal. The two pendent thiocyanate moieties in (1), with Zn–N–C angles 167.9(4)–173.9(4)º, coordinate the mental centre almost linearly while the corresponding coordinations in (2) are significantly bent [Zn–N–C angles 150.8(3)–153.1(2)°]. Intermolecular N–H…S hydrogen bonds stabilise the crystal packing in the complexes forming infinite chains parallel to the [100] direction. The combinations of molecular chains generate three/two dimensional supramolecular framework in complexes (1) and (2). (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)