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101.
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103.
Cafarchia C Otranto D Campbell BE Latrofa MS Guillot J Gasser RB 《Electrophoresis》2007,28(8):1176-1180
Members of the genus Malassezia are budding yeasts, characterized by a thick cell wall. Recently, these yeasts have received attention as emerging pathogens. They are common commensals on the skin of animals and can become pathogenic under the influence of various predisposing factors. Central to studying their taxonomy, systematics, and ecology and to diagnosis is the accurate identification of species or operational taxonomic units. To overcome the limitations of current phenotypic and biochemical methods of identification, a PCR-coupled SSCP approach, utilizing sequence variation (0.4-33.5%) in short regions (approximately 250-270 bp) of the first internal transcribed spacer (ITS-1) of nuclear ribosomal DNA and the chitin synthase-2 gene (chs-2), was assessed for the identification and differentiation of different species/genotypes of Malassezia, characterized previously by DNA sequencing. Genomic DNA samples (n = 30) from Malassezia isolates cultured from canine skin scrapings were assessed by SSCP analysis of the two different genetic loci, and unequivocal delineation between genotypes and species was achieved. This SSCP approach is considered to provide a practical tool for the rapid and reliable genetic characterization of Malassezia genotypes/species from dogs and for investigating their population genetics and ecology. It will also provide a powerful tool for studies of Malassezia isolates from other animal species. 相似文献
104.
Stefania?Gaudino Chiara?Galas Maria?Belli Sabrina?Barbizzi Paolo?de?Zorzi Radojko?Ja?imovi? Zvonka?Jeran Alessandra?Pati Umberto?SansoneEmail author 《Accreditation and quality assurance》2007,12(2):84-93
The measurement of trace-element concentration in soil, sediment and waste, is generally a combination of a digestion procedure
for dissolution of elements and a subsequent measurement of the dissolved elements. “Partial” and “total” digestion methods
can be used in environmental monitoring activities. To compare measurement results obtained by different methods, it is crucial
to determine and to maintain control of the bias of the results obtained by these methods. In this paper, ICP-MS results obtained
after matrix digestion with modified aqua regia (HCl+HNO3+H2O2) method and two “total” digestion methods (microwave aqua regia+HF and HNO3+HF) are compared with those obtained by instrumental neutron activation analysis, a non-destructive analytical method for
the determination of the total mass concentrations of inorganic components in environmental matrices. The comparison was carried
out on eight agricultural soil samples collected in one test area and measured by k0-INAA and ICP-MS to determine As, Co, Cr, Sb and Zn mass concentration. The bias of results for As, Cd, Co, Cr, Cu, Ni, Pb,
Sb and Zn of the three digestion methods were assessed using selected measurement standards. This paper highlights that the
digestion procedure is an integral part of the measurement and can affect the measurement result in environmental analysis. 相似文献
105.
Oxytetracycline as environmental contaminant in arable lands 总被引:2,自引:0,他引:2
Brambilla G Patrizii M De Filippis SP Bonazzi G Mantovi P Barchi D Migliore L 《Analytica chimica acta》2007,586(1-2):326-329
Oxytetracycline (OXY) is a broad-range antimicrobial routinely used in pig production, at doses in the range of few g/kg of medicated feed, during the weaning period. It could persist at ppm level in pig liquid manure that routinely is used for organic fertilisation. In the present work we describe a methodology to study OXY environmental fate in arable land where crops are cultivated for animal feeding purposes. A liquid-liquid extraction followed by metal chelate affinity chromatography was applied to environmental samples of manures and soils drawn within a case-control study. Extracts were then analysed by high performance liquid chromatography with UV/DAD detection, using a reverse phase column, and expressing the results as 4-epioxytetracycline epimer. Results indicate OXY is well retained at mg kg(-1) levels in soil exposed to contaminated pig manure fertilisation. Such compartment could constitute an abiotic reservoir for the systemic and/or for the external contamination of corn. 相似文献
106.
Citrus aurantium (bitter orange) is a plant belonging to the family Rutaceae, whose fruit extracts have been used recently for the treatment of obesity. The most important biologically active constituents of the C. aurantium fruits are phenethylamine alkaloids (i.e. octopamine, synephrine, tyramine, N-methyltyramine and hordenine). Synephrine is a primary synthesis compound with pharmacological activities such as vasoconstriction, elevation of blood pressure and relaxation of bronchial muscle. Synephrine is present in the peel and the edible part of Citrus fruit. Of the adrenergic amines of natural origin, synephrine has been found to be the main constituent of C. aurantium fruits and extracts; the other alkaloids are either absent or present in only low concentrations. It is known that synephrine and the other amines found in C. aurantium have adverse effects on the cardiovascular system, owing to adrenergic stimulation. In light of the great commercial proliferation of C. aurantium herbal medicines in recent years, this review provides an overview of various extraction, separation and detection techniques employed for the qualitative and quantitative determination of the alkaloids in C. aurantium and related species. The application of chromatographic and electrophoretic methods for the separation and determination of these active components in C. aurantium plant material and derivatives are described. Since synephrine is a chiral compound, enantioselective chromatographic and electrophoretic techniques for the analysis of synephrine enantiomers in natural products are presented. Furthermore, examples of identification of these active compounds in complex matrices by hyphenated methods, such as gas chromatography-mass spectrometry and high-performance liquid chromatography-mass spectrometry, are described. The advantages and limitations of these separation and identification methods are assessed and discussed. 相似文献
107.
Marilena Muraglia Carlo Franchini Filomena Corbo Antonio Scilimati Vincenzo Tortorella Maria Stefania Sinicropi Annamaria De Luca Michela De Bellis Diana Conte Camerino 《Journal of heterocyclic chemistry》2007,44(5):1099-1103
108.
Bellezza F Cipiciani A Quotadamo MA Cinelli S Onori G Tacchi S 《Langmuir : the ACS journal of surfaces and colloids》2007,23(26):13007-13012
The adsorption of myoglobin (Mb) onto phosphate grafted-zirconia (ZrO2-P) nanoparticles was studied in terms of conformational studies and thermal stability, determined by circular dichroism (CD), differential scanning calorimetry (DSC), and atomic force microscopy (AFM). The changes in protein structure have been correlated with the catalytic activity of free and adsorbed Mb. CD and DSC studies indicate marked rearrangements in Mb structure upon adsorption onto phosphate-grafted zirconia nanoparticles. These structural rearrangements of Mb could be responsible for the loss of catalytic activity observed for the adsorbed Mb. In particular, the conformational changes due to the adsorption process induced a reduction of kcat and KM. AFM measurements indicate that the interaction with the grafted-zirconia nanoparticles also affects the morphology of the bound protein, inducing the nucleation of prefibrillar-like aggregates. 相似文献
109.
Lucia De Crescentini Gianfranco Favi Giacomo Mari Gianluca Ciancaleoni Marcello Costamagna Stefania Santeusanio Fabio Mantellini 《Molecules (Basel, Switzerland)》2021,26(21)
Here we report the synthesis of interesting 3-alkyl-4-hydroxy-1-aryl-4-(propa-1,2-dienyl)1H-pyrazol-5(4H)-ones and 9-alkyl-7-aryl-1-oxa-7,8-diazaspiro[4.4]nona-3,8-dien-6-ones, starting from 1,2-diaza-1,3-dienes (DDs) and propargyl alcohol. The reaction proceeds through a sequence Michael-type nucleophilic attack/cyclization/[2,3]-Wittig rearrangement. In the same way, the reaction between the aforementioned DDs and allyl alcohol furnished 4-allyl-4-hydroxy-3-alkyl-1-aryl-1H-pyrazol-5(4H)-ones. A DFT study was also carried out, in order to have decisive clarifications about the mechanism. 相似文献
110.
Valentina Verdoliva Giuseppe Digilio Michele Saviano Stefania De Luca 《Molecules (Basel, Switzerland)》2021,26(20)
Aziridine derivatives involved in nucleophilic ring-opening reactions have attracted great interest, since they allow the preparation of biologically active molecules. A chemoselective and mild procedure to convert a peptide cysteine residue into lanthionine via S-alkylation on aziridine substrates is presented in this paper. The procedure relies on a post-synthetic protocol promoted by molecular sieves to prepare lanthionine-containing peptides and is assisted by microwave irradiation. In addition, it represents a valuable alternative to the stepwise approach, in which the lanthionine precursor is incorporated into peptides as a building block. 相似文献