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31.
Panagiota-Yiolanda Stergiou Athanasios Foukis Helen Sklivaniti Paraskevi Zacharaki Maria Papagianni Emmanuel M. Papamichael 《Applied biochemistry and biotechnology》2012,168(3):672-680
In this study, the production and optimization of extracellular lipase from Kluyveromyces marxianus IFO 0288 was investigated by using optimized nutritional and cultural conditions in a yeast medium containing glucose as the carbon source in fully aerobic batch fermentation (150?rpm). The influence of four fermentation parameters (type of lipidic source, initial culture pH, temperature, and length of fermentation) on growth and lipase production was investigated and evaluated using the conventional ??one variable at a time?? approach and response surface methodology. An 18-fold increase in lipase production during 65?h of fermentation was obtained with optimized nutritional (0.5?% olive oil) and cultivation (pH?6.5, 35?°C) conditions by employing the conventional optimization method. By applying the response surface methodology technique the initial pH value of 6.4 and temperature of 32.5?°C were identified as optimal and led to further improvements (up to 18-fold) of extracellular lipase production. The results provide, for the first time, evidence that K. marxianus has the potential to be used as an efficient producer of extracellular lipase with prospective application in a variety of industrial and biotechnological areas. 相似文献
32.
Fotios Pasiouras Chrysovalantis Gaganis Constantin Zopounidis 《European Journal of Operational Research》2007,180(3):1317-1330
All UK companies are required by company law to prepare financial statements that must comply with law and accounting standards. With the exception of very small companies, financial accounts must then be audited by UK registered auditors who must express an opinion on whether these statements are free from material misstatements, and have been prepared in accordance with legislation and relevant accounting standards (unqualified opinion) or not (qualified opinion). The objective of the present study is to explore the potentials of developing multicriteria decision aid models for reproducing, as accurately as possible, the auditors’ opinion on the financial statements of the firms. A sample of 625 company audited years with qualified statements and 625 ones with unqualified financial statements over the period 1998–2003 from 823 manufacturing private and public companies is being used in contrast to most of the previous works in the UK that have mainly focused on very small or very large public companies. Furthermore, the models are being developed and tested using the walk-forward approach as opposed to previous studies that employ simple holdout tests or resampling techniques. Discriminant analysis and logit analysis are also used for comparison purposes. The out-of-time and out-of-sample testing results indicate that the two multicriteria decision aid techniques achieve almost equal classification accuracies and are both more efficient than discriminant and logit analysis. 相似文献
33.
J.N. Carney D.C. Colley M.F. James M. Jobes G.T. Jones J.B. Kinson K.M. Storr D.C. Watkins W. Dunwoodie A. Grant Y. Goldschmidt-Clermont F. Muller M. Nikolic Z. Sekera A. Stergiou 《Nuclear Physics B》1976,107(3):381-421
The reactions , and K+p → K0Δ++ have been systematically studied for eleven incident momenta between 3.0 and 16.0 GeV/c. Cross sections, differential cross sections and density matrix elements are presented. For K1(890) production the contributions from natural and unnatural parity exchanges have also been separated into I = 0 and I = 1 components. Effective trajectories have been extracted in the case of natural parity exchange, and also for Δ++ production. 相似文献
34.
Anastasios Stergiou Karam Asad Andreas Kourtellaris Dr. Nikos Chronakis Dr. Nikos Tagmatarchis 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(22):5751-5756
Bisazafullerene (C59N)2 has been functionalized under aerobic conditions with cyclo-[2]-octylmalonate through a Mannich-type reaction, furnishing the corresponding monoadduct. A regioselective tether-directed Bingel cyclopropanation reaction was then carried out on the azafullerene core to yield a single bisadduct. Spectroscopic analysis of the formed bisadduct showed it to have a C1 symmetrical structure, making it inherently chiral. Single-crystal X-ray analysis revealed the addition pattern of the azafullerene bisadduct to be equatorialface. Examination of the optical properties showed the evolution of new absorption bands, which can be used as signatures for the characterization of equatorialface bisadducts of C59N. Finally, redox assays showed that the LUMO level of the equatorialface bisadduct was increased compared to that of the parent (C59N)2. 相似文献
35.
Georgios A. Koulis Aristeidis S. Tsagkaris Panagiota A. Katsianou Panagiotis-Loukas P. Gialouris Ioannis Martakos Fotis Stergiou Alberto Fiore Eleni I. Panagopoulou Sofia Karabournioti Carsten Baessmann Noud van der Borg Marilena E. Dasenaki Charalampos Proestos Nikolaos S. Thomaidis 《Molecules (Basel, Switzerland)》2022,27(14)
Honey is a highly consumed commodity due to its potential health benefits upon certain consumption, resulting in a high market price. This fact indicates the need to protect honey from fraudulent acts by delivering comprehensive analytical methodologies. In this study, targeted, suspect and non-targeted metabolomic workflows were applied to identify botanical origin markers of Greek honey. Blossom honey samples (n = 62) and the unifloral fir (n = 10), oak (n = 24), pine (n = 39) and thyme (n = 34) honeys were analyzed using an ultra-high-performance liquid chromatography hybrid quadrupole time-of-flight mass spectrometry (UHPLC-q-TOF-MS) system. Several potential authenticity markers were revealed from the application of different metabolomic workflows. In detail, based on quantitative targeted analysis, three blossom honey markers were found, namely, galangin, pinocembrin and chrysin, while gallic acid concentration was found to be significantly higher in oak honey. Using suspect screening workflow, 12 additional bioactive compounds were identified and semi-quantified, achieving comprehensive metabolomic honey characterization. Lastly, by combining non-targeted screening with advanced chemometrics, it was possible to discriminate thyme from blossom honey and develop binary discriminatory models with high predictive power. In conclusion, a holistic approach to assessing the botanical origin of Greek honey is presented, highlighting the complementarity of the three applied metabolomic approaches. 相似文献
36.
37.
Tangoulis V Malamatari DA Soulti K Stergiou V Raptopoulou CP Terzis A Kabanos TA Kessissoglou DP 《Inorganic chemistry》1996,35(17):4974-4983
Two mixed-valence Mn(III)Mn(II) complexes and a homo-valence Mn(II) trinuclear manganese complex of stoichiometry Mn(III)Mn(II)Mn(III)(5-Cl-Hsaladhp)(2)(AcO)(4)(MeOH)(2).4CH(3)OH (1a), Mn(III)Mn(II)Mn(III) (Hsaladhp)(2)(AcO)(2)(5-Cl-Sal)(2)(thf)(2) (3a) and Mn(II)Mn(II)Mn(II) (AcO)(6)(pybim)(2) (1b) where H(3)saladhp is a tridentate Schiff base ligand and pybim a neutral bidentate donor ligand, have been structurally characterized by using X-ray crystallography. The structurally characterized mixed-valence complexes have strictly 180 degrees Mn(III)-Mn(II)-Mn(III) angles as required by crystallographic inversion symmetry. The complexes are valence trapped with two terminal Mn(III) ions showing Jahn-Teller distortion along the acetate or salicylate-Mn(III)-X axis. The Mn.Mn separation is 3.511 ? and 3.507 ? respectively. The mixed-valence complexes have S = (3)/(2) ground state and the homovalence complex S = (5)/(2), with small antiferromagnetic exchange J couplings, -5.6 and -1.8 cm(-1), respectively, while the powder ESR spectra at 4 K show a broad low field signal with g approximately 4.3 for Mn(III)Mn(II)Mn(III) and a broad temperature-dependent signal at g = 2 for Mn(II)Mn(II)Mn(II). Crystal data for 1a: [C(36)H(60)O(20)N(2)Cl(2)Mn(3)], triclinic, space group P&onemacr;, a = 9.272(7) ?, b = 11.046(8) ?, c = 12.635(9) ?, alpha = 76.78(2) degrees, beta = 81.84(2) degrees, gamma = 85.90(2) degrees, Z = 1. Crystal data for 3a: [C(48)H(56)O(18)N(2)Cl(2)Mn(3)], monoclinic, space group P2(1)/n, a = 8.776(3) ?, b = 22.182(7) ?, c = 13.575(4) ?, beta = 94.44(1) degrees, Z = 2. Crystal data for 1b: [C(36)H(36)O(12)N(6)Mn(3)], triclinic, space group P&onemacr;, a = 13.345(6) ?, b = 8.514(4) ?, c = 9.494(4) ?, alpha = 75.48(1) degrees, beta = 75.83(1) degrees, gamma = 76.42(1) degrees, Z = 1. 相似文献
38.
39.
Fotios Pasiouras Chrysovalantis Gaganis Constantin Zopounidis 《European Journal of Operational Research》2010
The purpose of the present study is the development of classification models for the identification of acquirers and targets in the Asian banking sector. We use a sample of 52 targets and 47 acquirers that were involved in acquisitions in 9 Asian banking markets during 1998–2004 and match them by country and time with an equal number of non-involved banks. The models are developed and validated through a tenfold cross-validation approach using two multicriteria decision aid techniques. For comparison purposes we also develop models through discriminant analysis. The results indicate that the multicriteria decision aid models are more efficient that the ones developed through discriminant analysis. Furthermore, in all the cases the models are more efficient in distinguishing between acquirers and non-involved banks than between targets and non-involved banks. Finally, the models with a binary outcome achieve higher accuracies than the ones which simultaneously distinguish between acquirers, targets and non-involved banks. 相似文献
40.
V. C. Stergiou E. Sarantopoulou Y. S. Raptis E. Anastassakis N. T. Pelekanos A. Arnoult 《高压研究》2013,33(1-6):101-107
Abstract Single and multiple quantum wells (QWs) of CdTe/Cd1?xZnxTe, of different composition (x), grown on a Cd1?xZnxTe (001) substrate are studied by Raman spectroscopy at low temperature, under resonance conditions. Two of the three phonon deformation potentials (PDPs) of the LO phonon of CdTe are calculated using the observed phonon frequency shifts due to a lattice-misfit bisotropic strain. 相似文献