bluuebunny/crossref_metadata_2025_split huggingface dataset:
Raman and IR study on copper binding of histamine
Authors: Torreggiani A. , Tamba M. , Bonora S. , Fini G. 
Published: June 2003

AbstractA comparative Raman and FTIR study of histamine (Hm), a small hormone present in a wide selection of living organisms, and its complexes with copper(II) at different pH values was carried out. Both the Raman and IR spectra present some marker bands useful for the identification of the structure of the species predominating in the Cu(II) aqueous and alcoholic systems. In particular, Raman spectroscopy appears to be a useful tool for analyzing the tautomeric equilibrium of the imidazole ring of Hm, because some bands (i.e., νC4C5) appear at different wavenumbers, depending on whether the imidazole moiety is in the Nτ‐H (tautomer I) or Nπ‐H (tautomer II) protonated form. In aqueous solutions the manner in which Hm binds to Cu(II) depends on the pH. At basic pH the most relevant species formed are a dimer, [Cu2L2H−2]2+, and a monomeric complex, [CuL]2− or [CuL2]+. On the contrary, by decreasing the pH, Hm acts as a mono‐ or bidentate ligand, giving rise to two types of monomeric complexes, [CuLH]2− and [CuL]2− or [CuL2]+. With respect to the Cu(II)–Hm alcoholic system, both the aminic group and the imidazole ring (tautomer I) take part in the Cu(II) coordination, leading to the formation of the [CuL]2− or [CuL2]+ monomeric complex. © 2003 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy), 2003
Mapping functional associations in the entire genome of Drosophila melanogaster using fusion analysis
Authors: Iliopoulos Ioannis , Enright Anton J. , Poullet Patrick , Ouzounis Christos A. 
Published: June 2003

AbstractWe have previously shown that the detection of gene fusion events can contribute towards the elucidation of functional associations of proteins within entire genomes. Here we have analysed the entire genome of Drosophila melanogaster using fusion analysis and two additional constraints that improve the reliability of the predictions, viz. low sequence similarity and low degree of paralogy of the component proteins involved in a fusion event. Imposing these constraints, the total number of unique component pairs is reduced from 18 654 to a mere 220 cases, which are expected to represent some of the most reliably detected functionally associated proteins. Using additional information from sequence databases, we have been able to detect pairs of functionally associated proteins with important functions in cellular and developmental pathways, such as spermatogenesis and programmed cell death. Copyright © 2003 John Wiley & Sons, Ltd.
ORF organization and gene recognition in the yeast genome
Authors: Luo Liaofu , Li Hong , Zhang Lirong 
Published: June 2003

AbstractSome rules on gene recognition and ORF organization in the Saccharomyces cerevisiae genome are demonstrated by statistical analyses of sequence data. This study includes: (a) The random frame rule—that the six reading frames W1, W2, W3, C1, C2 and C3 in the double‐stranded genome are randomly occupied by ORFs (related phenomena on ORF overlapping are also discussed). (b) The inhomogeneity rule—coding and non‐coding ORFs differ in inhomogeneity of base composition in the three codon positions. By use of the inhomogeneity index (IHI), one can make a distinction between coding (IHI > 14) and non‐coding (IHI ≤ 14) ORFs at 95% accuracy. We find that ‘spurious’ ORFs (with IHI ≤ 14) are distributed mainly in three classes of ORFs, namely, those with ‘similarity to unknown proteins’, those with ‘no similarity’, or ‘questionable ORFs’. The total number of spurious ORFs (which are unlikely to be regarded as coding ORFs) is estimated to be 470. (c) The evaluation of ORF length distribution shows that below 200 amino acids the occurrence of ATG initiator ORFs is close to random. Copyright © 2003 John Wiley & Sons, Ltd.
Association of polymorphisms in the human IL4 and IL5 genes with atopic bronchial asthma and severity of the disease
Authors: Freidin Maxim B. , Kobyakova Olga S. , Ogorodova Ludmila M. , Puzyrev Valery P. 
Published: June 2003

AbstractTwo polymorphisms in the IL4 (G/C 3′‐UTR) and IL5 (C‐703T) genes were studied in a sample of families whose probands had atopic bronchial asthma (BA) (66 families, n = 183) and in a group of non‐cognate individuals with the severe form of the disease (n = 34). The samples were collected from the Russian population in the city of Tomsk (Russia). Using the transmission/disequilibrium test (TDT), a significant association of allele C‐703 IL5 with BA was established (TDT = 4.923, p = 0.007 ± 0.0007). The analysis of 40 individuals with mild asthma and 49 patients with the severe form of the disease revealed a negative association of genotype GG IL4 (OR = 0.39, 95% CI = 0.15–0.99, p = 0.035), and also a trend towards a positive association of the GC IL4 genotype (OR = 2.52, 95% CI = 0.98–6.57, p = 0.052) with mild BA. There was a concordance of the clinical classification of BA severity with the ‘genotype’ (McNemar's X2 test with continuity correction constituted 0.03, d.f. = 1, p = 0.859). These results suggest that polymorphisms in the IL4 and IL5 genes contribute to the susceptibility to atopic BA and could determine the clinical course of the disease. Copyright © 2003 John Wiley & Sons, Ltd.
Methylation analysis of several tumour suppressor genes shows a low frequency of methylation of CDKN2A and RARB in uveal melanomas
Authors: Zeschnigk Michael , Tschentscher Frank , Lich Christina , Brandt Birgit , Horsthemke Bernhard , Lohmann Dietmar R. 
Published: June 2003

AbstractWe have investigated the frequency of methylation of several tumour suppressor genes in uveal melanoma. As the loss of one copy of chromosome 3 (monosomy 3), which is found in about half of these tumours, is tightly associated with metastatic disease, a special emphasis was laid on genes located on this chromosome, including the fragile histidine triad (FHIT), von Hippel–Lindau (VHL), β‐catenin (CTNNB1), activated leukocyte cell adhesion molecule (ALCAM) and retinoic acid receptor‐β2 (RARB) genes. In addition, the methylation patterns of the CpG‐rich regions 5′ of the E‐cadherin ( CDH1), p16/cyclin‐dependent kinase inhibitor 2 A (CDKN2A) and retinoblastoma (RB1) genes were analysed by bisulphite genomic sequencing or methylation‐specific PCR (MSP). Furthermore, the SNRPN and D15S63 loci, which are located in the imprinted region of chromosome 15, were included in the study. Aberrant methylation was detected in nine of 40 tumours analysed: The imprinted SNRPN and D15S63 loci were hypermethylated in three tumours, all of which retained both copies of chromosome 3. Methylated RARB alleles were detected in three tumours, whereas in three other tumours CDKN2A was found to be methylated. As we did not find RARB and CDKN2A preferentially methylated in tumours with monosomy 3, which is a significant predictor of metastatic disease, we suggest that these genes may play a causative role in the formation of uveal melanoma but not in the development of metastases. Copyright © 2003 John Wiley & Sons, Ltd.
Ordering and Clathrate Hydrate Formation in Co‐deposits of Xenon and Water at Low Temperatures
Authors: Nakayama Hirokazu , Klug Dennis D. , Ratcliffe Christopher I. , Ripmeester John A. 
Published: June 2003

AbstractLocal ordering in co‐deposits of water and xenon atoms produced at low temperatures can be followed uniquely by 129Xe NMR spectroscopy. In water‐rich samples deposited at 10 K and observed at 77 K, xenon NMR results show that there is a wide distribution of arrangements of water molecules around xenon atoms. This starts to order into the definite coordination for the structure I, large and small cages, when samples are annealed at ∼140 K, although the process is not complete until a temperature of 180 K is reached, as shown by powder Xray diffraction. There is evidence that Xe⋅20 H2O clusters are prominent in the early stages of crystallization. In xenon‐rich deposits at 77 K there is evidence of xenon atoms trapped in Xe⋅20 H2O clusters, which are similar to the small hydration shells or cages observed in hydrate structures, but not in the larger water clusters consisting of 24 or 28 water molecules. These observations are in agreement with results obtained on the formation of Xe hydrate on the surface of ice surfaces by using hyperpolarized Xe NMR spectroscopy. The results indicate that for the various different modes of hydrate formation, both from Xe reacting with amorphous water and with crystalline ice surfaces, versions of the small cage are important structures in the early stages of crystallization.
The Quest for PdII–PdII Interactions: Structural and Spectroscopic Studies and Ab Initio Calculations on Dinuclear [Pd2(CN)4(μ‐diphosphane)2] Complexes
Authors: Xia Bao‐Hui , Che Chi‐Ming , Zhou Zhong‐Yuan 
Published: June 2003

AbstractStructural and spectroscopic properties of and theoretical investigations on dinuclear [Pd2(CN)4(P–P)2] (P–P=bis(dicyclohexylphosphanyl)methane (1), bis(dimethylphosphanyl)methane (2)) and mononuclear trans‐[Pd(CN)2(PCy3)2] (3) complexes are described. Xray structural analyses reveal Pd⋅⋅⋅Pd distances of 3.0432(7) and 3.307(4) Å in 1 and 2, respectively. The absorption bands at λ>270 nm in 1 and 2 have 4d${_{\sigma }^{{\ast}}}$→5pσ electronic‐transition character. Calculations at the CIS level indicate that the two low‐lying dipole‐allowed electronic transition bands in model complex [Pd2(CN)4(μ‐H2PCH2PH2)2] at 303 and 289 nm are due to combinations of many orbital transitions. The calculated interaction‐energy curve for the skewed dimer [{trans‐[Pd(CN)2(PH3)2]}2] is attractive at the MP2 level and implies the existence of a weak PdII–PdII interaction.
Rational Design of a Ferromagnetic Trinuclear Copper(II) Complex with a Novel in‐situ Synthesised Metalloligand
Authors: Tong Ming‐Liang , Wu Yin‐Miao , Tong Ye‐Xiang , Chen Xiao‐Ming , Chang Ho‐Chol , Kitagawa Susumu 
Published: June 2003

AbstractAn interesting ferromagnetic linear trinuclear copper(II) compound containing an in‐situ synthesised functional ligand has been rationally obtained and crystallographically characterised, confirming a new route to magnetic polynuclear clusters. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Sensitive Adsorptive Stripping Voltammetric Methodologies for the Determination of Melatonin in Biological Fluids
Authors: Corujo‐Antuña J. L. , Martínez‐Montequín S. , Fernández‐Abedul M. T. , Costa‐García A. 
Published: June 2003

AbstractThe reversible redox process that melatonin presented on carbon paste electrodes was the basis of a sensitive methodology for the determination of this hormone. From all the processes presented by this hormone, this was never used before as the basis of voltammetric measurements for melatonin determination. Therefore, parameters that affected the cyclic voltammetric signal were studied. A limit of detection as low as 9×10−11 M was obtained when optimized alternating current voltammetry was employed. The reproducibility was excellent due to an adequate pretreatment of the solid electrode (RSD=2.7%, n=10). A comparison with methodologies that employ different electrochemical techniques from the point of view of their analytical characteristics was made. This methodology has proved to be suitable for the determination of melatonin in biological fluids.
Construction and Characterization of Ru(II)Tris(bipyridine)‐Based Silica Thin Film Electrochemiluminescent Sensors
Authors: Armelao Lidia , Bertoncello Renzo , Gross Silvia , Badocco Denis , Pastore Paolo 
Published: June 2003

AbstractRu(II) tris‐bipyridine based ECL sensors were produced by embedding the complex inside silica glass thin films deposited via a sol‐gel dipping procedure on K‐glass conducing substrates. Films were prepared starting from a pre‐hydrolyzed ethanolic solution of Si(OC2H5)4 and Ru(bpy)3Cl2. Transparent, crack‐free and homogeneous reddish silica layers, having a thickness of 200±20 nm, were obtained. The films, either deposited at room temperature or thermally annealed at 100, 200 and 300 °C for 30 h, were structurally and chemically characterized. Ru(bpy)3Cl2 thermal stability was previously checked by thermogravimetric analysis (TGA). The films were investigated by X‐Ray photoelectron spectroscopy (XPS), secondary ion mass spectrometry (SIMS) and UV‐vis spectroscopy. XPS in‐depth profiles revealed a homogeneous distribution of the ruthenium complex inside the silica thin layers. SIMS data suggested that the embedded Ru(bpy)3Cl2 did not react with oxygen inside the oxygen‐rich silica matrix to give Ru‐O bonds. Electrochemical and ECL characterization of the thin film electrodes were made by means of cyclic voltammetry (CV) and controlled potential step experiments. The ECL sensor showed a diffusive redox behavior of the Ru(bpy)32+/Ru(bpy)33+ system. Light emission produced from the reaction between oxalic acid and the electrogenerated Ru(bpy)33+ was larger and stable when thermally treated electrodes were used after a suitable hydration period. The 300 °C treated sample was the best performing sensor both in terms of low complex leakage and sensitivity. Calibration plots relative to oxalic acid were obtained both in stationary and in flowing solutions in the concentration range 2×10−6−3×10−4 M. A linear behavior appeared in the former case, while in the latter a slight curvature was evident as a consequence of a finite diffusion time of the analyte inside the thin film. The signal repeatability, obtained by multiple 100 μL of 10−5 M oxalic acid injections in flowing solutions, was better than 4%. The obtained detection limit (computed as three times the standard deviation of the base‐line noise) was 10−6 M as oxalic acid.
Biodegradation of aromatic hydrocarbons in a compost biofilter
Authors: Torkian Ayoob , Dehghanzadeh Reza , Hakimjavadi M 
Published: June 2003

AbstractTwo laboratory‐scale biofilters filled with the same type of packing material were operated at different gas flow rates and influent concentrations of toluene and xylene in order to investigate their performance in treating waste gas streams. The columns contained a mixture of municipal compost as a base material and wood chips as a bulking agent in an 80:20 ratio; the porosity was 54%. Microbial acclimation was achieved by addition of nutrient‐enriched solution along with pollutants for a week by daily mixing and natural aeration. During the start‐up of the systems with inlet concentrations of 20 and 70 ppm for toluene and xylene, respectively, high biomass growth resulted in pressure drops in excess of 2000 Pam−1. Under steady state conditions, the response of each biofilter to variations in contaminant mass loading was studied by either changing the influent concentration or flow rate of the inlet waste stream. The results show that organic loading rates of up to 110 and 150 gm−3h−1 can be handled without any indication of the elimination capacity being saturated. However, maintaining the pressure drop below 1000 Pam−1 to avoid operational problems, optimal organic loading rates for toluene and xylene of 78 ± 8 and 80 ± 14 gm−3h−1 respectively are suggested for an HRT value of 60 s. Under these conditions, elimination capacities of 73 ± 4 and 73 ± 14 gm−3h−1 and removal efficiencies of 94 ± 6% and 91 ± 8% were achieved for toluene and xylene, respectively. Copyright © 2003 Society of Chemical Industry
Kinetics, degradation pathway and reaction mechanism of advanced oxidation of 4‐nitrophenol in water by a UV/H2O2 process
Authors: Zhang Wenbing , Xiao Xianming , An Taicheng , Song Zhiguang , Fu Jiamo , Sheng Guoying , Cui Mingchao 
Published: June 2003

AbstractPhotooxidation of 4‐nitrophenol (4‐NP) in water by the UV/H2O2 advanced oxidation process was carried out in order to investigate the kinetics and pathway of 4‐NP degradation. The experimental results showed that the photodegradation of 4‐NP accorded well with pseudo‐first order kinetics. The effects of different parameters, such as H2O2 dosage, pH value and various anion scavengers on the degradation of 4‐NP have been investigated in detail. It was found that acidic conditions are more favorable to the degradation of 4‐NP but many anions, such as HCO3−, NO3− and Cl−, slow down the photooxidation rate of 4‐NP. Hydroquinone, 1,2,4‐trihdroxybenzene, 4‐nitropyrogallol, and 4‐nitrocatechol were tentatively identified as the intermediates of 4‐NP degradation by GC/MS after samples were derivatized by N,O‐bis(trimethylsilyl)‐trifluoroacetamide (BSTFA). A degradation pathway was proposed to account for the observed intermediates produced during 4‐NP degradation by the UV/H2O2 process. Copyright © 2003 Society of Chemical Industry
Enzymatic hydrolysis of dissolved corn stalk hemicelluloses: reaction kinetics and modeling
Authors: Belkacemi Khaled , Hamoudi Safia 
Published: June 2003

AbstractThe enzymatic hydrolysis of hemicelluloses as a filtrate originating from aqueous/steam pretreated corn stalks was carried out using commercial enzyme systems of several activities composed of cellulases and β‐D‐xylosidases from Aspergillus niger. The hydrolysis was conducted using free enzymes in aqueous substrate solution at a temperature of 30 °C and a pH of 5. Saccharification corresponding to 90% of potential simple sugar release was obtained after 10 h using 0.12 activity units (U) of Cellulases_1 complex per mg of dissolved solids present in the filtrate. Synergetic action of Cellulases_1 enzyme complex and β‐D‐xylosidases proved to be effective for the hydrolysis of plant hemicelluloses. A lumped model based on the Michaelis–Menten approach successfully described the fate of the lumped variables describing the hydrolysis of the overall kinetics of corn stalk hemicelluloses. The maximum saccharification rate evolved with the cellulases concentration as $V_{{\max_{i}}}^{{\rm app}} = K \cdot [{Cellulases}]^{n}$. This overall and pseudokinetic tendency was comparable to those reported in the literature for more simple systems employing a defined substrate and a pure hydrolytic enzyme. The n‐value was found to be in the range of 0.1–0.9 depending on the substrate lump involved in the reaction system. Copyright © 2003 Society of Chemical Industry
Synthesis, characterization and immunochemical evaluation of cephalosporin antigenic determinants
Authors: Sánchez‐Sancho Francisco , Perez‐Inestrosa Ezequiel , Suau Rafael , Montañez María I. , Mayorga Cristobalina , Torres Maria J. , Romano Antonino , Blanca Miguel 
Published: June 2003

AbstractLack of knowledge of the exact chemical structure of cephalosporin antigenic determinants has hindered clinical interpretation of adverse reactions to these drugs and delayed understanding of the mechanisms involved in the specific recognition and binding of IgE molecules to these antigenic determinants. We further resolve the relationship between structure and activity of proposed antigenic chemicals, including the rational design and synthesis of these haptenic structures. Comparative RAST inhibition studies of the synthesized molecules revealed that they were recognized by IgE antibodies induced by cephalosporin antibiotics. Thus, these data indicate that recognition is mainly directed to the acyl side chain and to the β‐lactam fragment that remains linked to the carrier protein in the cephalosporin conjugation course. Copyright © 2003 John Wiley & Sons, Ltd.
Effect of tillage and rotation on organic carbon forms of chernozemic soils in Saskatchewan
Authors: Wu Tianyun , Schoenau Jeff J. , Li Fengmin , Qian Peiyuan , Malhi Sukhdev S. , Shi Yuanchun 
Published: June 2003

AbstractThe effects of selected tillage and rotation systems on soil organic carbon and its fractions were studied on Chernozemic soils in south‐western and east‐central Saskatchewan. After practicing a no‐till fallow unfertilized‐wheat rotation for 7 years on an Orthic Brown Chernozem in south‐western Saskatchewan, total soil organic carbon (TOC) in the 0 – 5 cm and 5 – 10 cm layers was slightly lower than the tillage fallow‐unfertilized wheat comparable treatment. However, light fraction of organic carbon (LFOC) was similar in the two treatments. Comparison of the tillage fallow‐unfertilized wheat to a treatment involving conversion to a fertilized continuous cropping system for 10 years showed TOC increased slightly in the two depths and LFOC increased by 24 % and 29 % in the 0 – 5 cm and 5 – 10 cm layer, respectively, of the continuous cropping treatment. Microbial biomass carbon (MB‐C) was increased significantly at the 5 – 10 cm depth. After conversion of fallow‐wheat to alfalfa as perennial forage for 10 years, TOC increased by 80 % and 27 %, LFOC by 245 % and 286 %, and HFOC by 63 % and 20 % at 0 – 5 cm and 5 – 10 cm depths, respectively, compared to the tilled cereal‐fallow system. Meanwhile, water soluble organic carbon (WSOC) was not affected but MB‐C increased significantly.In an Orthic Black Chernozem in east‐central Saskatchewan, the depletion and restoration of organic carbon was observed when native sod was changed into cropland and then back to grassland. For example, the TOC of cropland under cereal‐fallow rotation for 62 years decreased by 42 % and 33 % at 0 – 5 cm and 5 – 10 cm depths, respectively, compared to native sod. The LFOC decreased by 79 % and 74 % in the layers, and reductions in WSOC and MB‐C were even greater. After cropland was re‐seeded to grassland for 12 years, the concentration of total organic carbon was increased by 16 % and 22 % while the mass of organic carbon was the same as the cropland in the two layers. The LFOC and MB‐C amounts in the grass seed‐down were double that of the cropped land, but the amounts of TOC, LFOC, and MB‐C in grass seed‐down were still significantly lower than the native sod.
Epoetin alpha, epoetin beta and darbepoetin alfa: Two‐dimensional gel electrophoresis isoforms characterization and mass spectrometry analysis
Authors: Caldini Anna , Moneti Gloriano , Fanelli Alessandra , Bruschettini Alessia , Mercurio Stefano , Pieraccini Giuseppe , Cini Elisabetta , Ognibene Agostino , Luceri Francesca , Messeri Gianni 
Published: June 2003

AbstractSince 1989 recombinant human erythropoietin (rhEPO) has been used as a drug for the correction of anemia, but the misuse of rhEPO as an ergogenic agent among athletes is a widespread doping practice. As a consequence there is a need for developing reference methods for the detection of rhEPO in biological fluids, and to be able to differentiate the recombinant from the natural protein. Recombinant human erythropoietin differs from its natural counterpart in the glycidic part of the molecule. Three different commercial recombinant products Epoetin alpha (Eprex, Janssen Cilag), Epoetin beta (Neorecormon, Roche) and Darbepoetin alfa (Nespo, Dompè) have been used to evaluate the performance of two‐dimensional gel electrophoresis (2‐DE) and mass spectrometry (MS) for the separation of isoforms and the identification of the proteins respectively. All the compounds studied were well separated by means of 2‐DE: Epoetin alpha and beta focused in the same isoelectric point region giving rise to six and eight spots respectively, whereas Darbepoetin alfa was found in a more acidic zone with two spots. Results obtained with micro high‐performance liquid chromatography‐electrospray ionization‐time of flight (TOF) MS and matrix‐assisted laser desorption/ionization‐time of flight MS for the three rhEPOs are reported. These preliminary results suggest that by means of 2‐DE and MS it should be possible to reveal the presence of rhEPOs for antidoping purposes.