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1.
Papatheodorou Nikolaos Kouroupetroglou Georgios Pino Alexandros Giannopoulos Panagiotis-Alexios Makris Gerasimos Papageorgiou Charalambos 《Universal Access in the Information Society》2021,20(2):321-331
Universal Access in the Information Society - We present an investigation of the systematic differences in upper limb motor skills between children with learning disabilities (LDs) and children... 相似文献
2.
Panagiotis Papageorgiou 《New Review of Information Networking》2015,20(1-2):214-218
Through the Preservation of Complex Objects Symposia (POCOS), leading researchers and practitioners have managed to propose strategies for preserving digital art and computer games. The same is not true for the preservation of archaeological visualizations. This article therefore discusses the following question: “Can emulation be employed to effectively preserve obsolete computer visualizations from the Archaeology domain?” Guidelines and test results coming from this work would be of great benefit to the archaeological community, and would contribute knowledge to other research communities, specifically those interested in similar data types/3D visualizations. 相似文献
3.
Elisavet Ioannou Anastassios C. Papageorgiou Nikolaos E. Labrou 《International journal of molecular sciences》2022,23(13)
The extensive application of herbicides in crop cultivation has indisputably led to the emergence of weed populations characterized by multiple herbicide resistance (MHR). This phenomenon is associated with the enhanced metabolism and detoxifying ability of endogenous enzymes, such as phi class glutathione transferases (GSTFs). In the present work, a library of mutant GSTFs was created by in vitro directed evolution via DNA shuffling. Selected gstf genes from the weeds Alopecurus myosuroides and Lolium rigidum, and the cereal crops Triticum durum and Hordeum vulgare were recombined to forge a library of novel chimeric GSTFs. The library was activity screened and the best-performing enzyme variants were purified and characterized. The work allowed the identification of enzyme variants that exhibit an eight-fold improvement in their catalytic efficiency, higher thermal stability (8.3 °C) and three-times higher inhibition sensitivity towards the herbicide butachlor. The crystal structures of the best-performing enzyme variants were determined by X-ray crystallography. Structural analysis allowed the identification of specific structural elements that are responsible for kcat regulation, thermal stability and inhibition potency. These improved novel enzymes hold the potential for utilization in biocatalysis and green biotechnology applications. The results of the present work contribute significantly to our knowledge of the structure and function of phi class plant GSTs and shed light on their involvement in the mechanisms of MHR. 相似文献
4.
5.
George Z. Papageorgiou Vasilios Tsanaktsis Dimitrios G. Papageorgiou Stylianos Exarhopoulos Maria Papageorgiou Dimitrios N. Bikiaris 《Polymer》2014
Poly(butylene 2,5-furan dicarboxylate) (PBF) is an alipharomatic polyester that can be prepared using monomers derived from renewable resources such as 2,5-furan dicarboxylic acid and 1,4-butanediol. In the present work the thermal behavior of PBF was studied. Multiple melting was observed during heating traces of samples isothermally crystallized from the melt using differential scanning calorimetry (DSC). The wide angle X-ray diffraction (WAXD) patterns did not reveal the presence of a second crystal population, or a crystal transition upon heating. DSC study showed that the phenomena are closely related to recrystallization. Temperature modulated DSC (TMDSC) tests indeed evidenced enhanced recrystallization. The equilibrium melting point was estimated to be 184.5 °C using the linear Hoffman–Weeks extrapolation. The heat of fusion of the pure crystalline polymer was found equal to 129 J/g or (27.35 kJ/mol), a little lower than that of PBT. The Lauritzen–Hoffman secondary nucleation theory was used and the surface energy values and the work of chain folding were found to be comparable to those of PBT, but quite lower than those of poly(ethylene terephthalate) (PET). The non-isothermal crystallization on cooling and the cold-crystallization of quenched samples were also studied. Condensed spherulites were observed on isothermal crystallization under large supercoolings by using polarized optical microscopy (POM), while the spherulites turned to ring-banded morphology at higher temperatures. In every case the nucleation density was high. 相似文献
6.
Konstantinos N. Kontogiannopoulos Andreana N. Assimopoulou Konstantinos Dimas Vassilios P. Papageorgiou 《European Journal of Lipid Science and Technology》2011,113(9):1113-1123
Alkannin and shikonin are naturally occurring hydroxynaphthoquinones with a well‐established spectrum of wound healing, antimicrobial, anti‐inflammatory, and antioxidant activities. Recently, extensive scientific effort has been focused on their effectiveness on several tumors and mechanism(s) of antitumor activity. Liposomes have been proved as adequate drug carriers offering significant advantages over conventional formulations, such as controlled release and targeted drug delivery, leading to the appearance of several liposomal formulations in the market, some of them concerning anticancer drugs. The aim of the present study was to prepare shikonin‐loaded liposomes for the first time in order to enhance shikonin therapeutic index. An optimized technique based on the thin film hydration method was developed and liposomes characterization was performed in terms of their physicochemical characteristics, drug entrapment efficiency, and release profile. Results indicated the successful incorporation of shikonin into liposomes, using both 1,2‐dipalmitoylphosphatidylcholine and egg phosphatidylcholine lipids. Liposomes presented good physicochemical characteristics, high entrapment efficiency and satisfactory in vitro release profile. In vitro cytotoxicity of liposomes was additionally tested against three human cancer cell lines (breast, glioma, and non‐small cell lung cancer) showing a moderate growth inhibitory activity. Practical applications: Shikonin is a naturally occurring hydroxynaphthoquinone and extensive scientific research (in vitro, in vivo, and clinical trials) has been conducted during the last years, focusing on its effectiveness on several tumors and mechanism(s) of antitumor action. The purpose of this work was to prepare and characterize shikonin‐loaded liposomes as a new drug delivery system for shikonin. Liposomal formulations provide significant advantages over conventional dosage forms, such as controlled release and targeted drug delivery for anticancer agents. Thus, liposomes could reduce shikonin's side effects, enhance selectivity to cancer cells and protect shikonin from internal biotransformations and instability matters (oxidization and polymerization). Furthermore, liposomal delivery helps overcome the low aqueous solubility of shikonin, which is the major barrier to its oral and internal administration, since it cannot be dissolved and further absorbed from the receptor. 相似文献
7.
In this work, a mixed integer linear programming (MILP) model is proposed for the multi-class data classification problem using a hyper-box representation. The latter representation is particularly suitable for capturing disjoint data regions. The objective function used is the minimisation of the total number of misclassified data samples. In order to improve the training and testing accuracy of our approach, an iterative solution procedure is developed to assign potential multiple boxes to each single class. Finally, the applicability of the proposed approach is demonstrated through a number of illustrative examples. According to the computational results obtained, the proposed optimisation-based approach is competitive in terms of prediction accuracy when compared with various standard classifiers. 相似文献
8.
Kalatzis I Piliouras N Ventouras E Papageorgiou CC Rabavilas AD Cavouras D 《Computer methods and programs in biomedicine》2004,75(1):11-22
A computer-based classification system has been designed capable of distinguishing patients with depression from normal controls by event-related potential (ERP) signals using the P600 component. Clinical material comprised 25 patients with depression and an equal number of gender and aged-matched healthy controls. All subjects were evaluated by a computerized version of the digit span Wechsler test. EEG activity was recorded and digitized from 15 scalp electrodes (leads). Seventeen features related to the shape of the waveform were generated and were employed in the design of an optimum support vector machine (SVM) classifier at each lead. The outcomes of those SVM classifiers were selected by a majority-vote engine (MVE), which assigned each subject to either the normal or depressive classes. MVE classification accuracy was 94% when using all leads and 92% or 82% when using only the right or left scalp leads, respectively. These findings support the hypothesis that depression is associated with dysfunction of right hemisphere mechanisms mediating the processing of information that assigns a specific response to a specific stimulus, as those mechanisms are reflected by the P600 component of ERPs. Our method may aid the further understanding of the neurophysiology underlying depression, due to its potentiality to integrate theories of depression and psychophysiology. 相似文献
9.
Elpiniki I. Papageorgiou Csaba Huszka Jos De Roo Nassim Douali Marie-Christine Jaulent Dirk Colaert 《Computer methods and programs in biomedicine》2013
This study aimed to focus on medical knowledge representation and reasoning using the probabilistic and fuzzy influence processes, implemented in the semantic web, for decision support tasks. Bayesian belief networks (BBNs) and fuzzy cognitive maps (FCMs), as dynamic influence graphs, were applied to handle the task of medical knowledge formalization for decision support. In order to perform reasoning on these knowledge models, a general purpose reasoning engine, EYE, with the necessary plug-ins was developed in the semantic web. The two formal approaches constitute the proposed decision support system (DSS) aiming to recognize the appropriate guidelines of a medical problem, and to propose easily understandable course of actions to guide the practitioners. The urinary tract infection (UTI) problem was selected as the proof-of-concept example to examine the proposed formalization techniques implemented in the semantic web. The medical guidelines for UTI treatment were formalized into BBN and FCM knowledge models. To assess the formal models’ performance, 55 patient cases were extracted from a database and analyzed. The results showed that the suggested approaches formalized medical knowledge efficiently in the semantic web, and gave a front-end decision on antibiotics’ suggestion for UTI. 相似文献
10.
Evgenios P. Avgerinos Nikolaos S. Papageorgiou 《Dynamical Systems: An International Journal》1991,6(1):17-32
In this paper we examine the variational stability of infinite-dimensional optimal control problems governed by nonlinear evolution equations. Our tools are the Kuratowski—Mosco convergence of sets and the corresponding τ-convergence of functions. We prove the τ-convergence of cost functional and the convergence of the values of the problems, and we examine the variational stability of the solution and reachable sets. These results are then applied to a sequence of nonlinear parabolic distributed-parameter optimal control problems 相似文献