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排序方式: 共有212条查询结果,搜索用时 15 毫秒
11.
Aris E. Giannakas Constantinos E. Salmas Areti Leontiou Dimitrios Moschovas Maria Baikousi Eleni Kollia Vasiliki Tsigkou Anastasios Karakassides Apostolos Avgeropoulos Charalampos Proestos 《Molecules (Basel, Switzerland)》2022,27(4)
Today, the use of natural biodegradable materials in the production processes is more and more adopted by industry to achieve cyclic economy targets and to improve environmental and human health indexes. Active packaging is the latest trend for food preservation. In this work, nanostructures were prepared by incorporation of thyme oil with natural natrium-montmorillonite and organo-montmorillonite with two different techniques, direct impregnation and the green evaporation–adsorption process. Such nanostructures were mixed with poly-L-lactic-acid for the first time via an extrusion molding process to develop a new packaging film. Comparisons of morphological, mechanical, and other basic properties for food packaging were carried out via XRD, FTIR, TG, SEM/EDS, oxygen and water vapor permeation, and antimicrobial and antioxidant activity for the first time. Results showed that poly-L-lactic-acid could be modified with clays and essential oils to produce improved active packaging films. The final product exhibits food odor prevention characteristics and shelf-life extension capabilities, and it could be used for active packaging. The films based on OrgMt clay seems to be more promising, while the thyme oil addition improves their behavior as active packaging. The PLLA/3%TO@OrgMt and PLLA/5%TO@OrgMt films were qualified between the tested samples as the most promising materials for this purpose. 相似文献
12.
Let Φ be a finite root system of rank n and let m be a nonnegative integer. The generalized cluster complex Δm(Φ) was introduced by S. Fomin and N. Reading. It was conjectured by these authors that Δm(Φ) is shellable and by V. Reiner that it is (m + 1)-Cohen-Macaulay, in the sense of Baclawski. These statements are proved in this paper. Analogous statements are shown
to hold for the positive part Δ+m(Φ) of Δm(Φ). An explicit homotopy equivalence is given between Δ+m(Φ) and the poset of generalized noncrossing partitions, associated to the pair (Φ, m) by D. Armstrong. 相似文献
13.
The biological activities of the enantiomeric rhodium(III)-nicotine complexes trans-[Rh(S-(–)-nicH+)4Cl2](PF6)5, trans-[Rh(R-(+)-nicH+)4Cl2](PF6)5 (97% enantiomerically pure) and trans-[Rh(RS-(±)-nicH+)4Cl2](PF6)5 were examined in detail on the Gram positive bacteria B. subtilis. Minimal inhibitory concentrations and exponential phases for each complex were calculated: the complexes were bactericidal at certain concentrations. Novel stereoselective phenomena are reported. 相似文献
14.
The solubilities of three cinnamic acid esters, namely, methyl ferulate, methyl p-coumarate, and methyl sinapate, have been measured in mixed solvent systems of tert-butanol with 1-butyl-3-methyl-imidazolium hexafluorophosphate ([BMIM][PF6]), 1-butyl-3-methyl-imidazolium tetrafluoroborate ([BMIM][BF4]) and 1-methyl-3-octyl-imidazolium tetrafluoroborate ([OMIM][BF4]) at 303.15 and 321.15 K, and in mixed solvent systems of ethyl acetate with [BMIM][BF4] and [OMIM][BF4] at 303.15 K. In eight cases, out of the 22 data sets, an additive behaviour of the solubility was observed, positive deviations from additivity were observed in six cases, a positive synergistic effect in five cases, and, finally, negative deviations from additivity in the remaining three cases. Prediction of the solubilities of the solutes in the various ternary systems was performed with the NRTL and UNIQUAC activity coefficient models. The binary interaction parameters of the models between solute and solvent molecules were taken from the literature. When the parameters between the solvent molecules are fitted to literature data, satisfactory predictions are not always obtained. On the other hand, very good predictions are obtained when only one of the two interaction parameters between the two solvent molecules is fitted to one single point of the solubility isotherm and the other interaction parameter is set equal to zero. 相似文献
15.
Natassa Pippa Eleni Kaditi Stergios Pispas Costas Demetzos 《Journal of nanoparticle research》2013,15(6):1-16
In this study, we report on the self assembly behavior and on stability studies of mixed (chimeric) nanosystems consisting of dipalmitoylphosphatidylcholine (DPPC) and poly(2-methyl-2-oxazoline)-grad-poly(2-phenyl-2-oxazoline) (MPOx) gradient copolymer in aqueous media and in fetal bovine serum (FBS). A gamut of light scattering techniques and fluorescence spectroscopy were used in order to extract information on the size and morphological characteristics of the nanoassemblies formed, as a function of gradient block copolymer content, as well as temperature. The hydrodynamic radii (R h) of nanoassemblies decreased in the process of heating up to 50 °C, while the fractal dimension (d f) values, also increased. Indomethacin was successfully incorporated into these chimeric nanocarriers. Drug release was depended on the components ratio. The present studies show that there are a number of parameters that can be used in order to alter the properties of chimeric nanosystems, and this is advantageous to the development of “smart” nanocarriers for drug delivery. 相似文献
16.
Eleni E. Moushi Theocharis C. Stamatatos Vassilios Nastopoulos George Christou Anastasios J. Tasiopoulos 《Polyhedron》2009,28(9-10):1814-1817
The reaction of [Mn(O2CMe)2] · 4H2O with pdH2 (1,3-propanediol) or mpdH2 (2-methyl-1,3-propanediol) in the presence of NaN3 in MeCN/py (py = pyridine) results in the formation of two new one-dimensional coordination polymers composed of a [MnIII6MnII11(μ4-O)8(μ3-N3)4]25+ octahedral unit. The peripheral ligation is completed by pd2? (or mpd2?), acetate, pyridine and μ-1,3-N3? ligands. The latter bridges each Mn17 unit to its neighboring one, resulting in the formation of the two 1-D coordination polymers. Variable-temperature dc magnetic susceptibility studies indicate the existence of predominantly ferromagnetic interactions and a resulting giant ground state spin within the Mn17 units and intermolecular antiferromagnetic exchange interactions between the neighboring Mn17 units that result in diamagnetic ground spin states for both polymeric compounds. 相似文献
17.
An experimental and theoretical study of butyl methacrylate in situ radical polymerization kinetics in the presence of graphene oxide nanoadditive
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Marios Michailidis George D. Verros Eleni A. Deliyanni Eleftherios G. Andriotis Dimitris S. Achilias 《Journal of polymer science. Part A, Polymer chemistry》2017,55(8):1433-1441
The butyl methacrylate radical polymerization kinetics in the presence of graphene oxide nanoadditive is studied both experimentally and theoretically. The experimental study includes the formation of graphite oxide from the oxidation of graphite and its subsequent transformation to graphene oxide (GO) after ultrasonication and in situ polymerization. Monomer conversion versus time was monitored gravimetrically at various reaction temperatures and initial GO fractions. Formation of GO was verified by X‐ray diffraction spectra and the number and weight average molecular weights of the final polymer were obtained from GPC measurements. A detailed theoretical kinetic model was further developed. The model predictions were found to be in satisfactory agreement with the experimental data. The presence of GO was found to result in reduced initiator efficiency verified theoretically and explained through side reactions of primary radicals. Finally, nanocomposites showed enhanced thermal stability compared to neat PBMA. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 1433–1441 相似文献
18.
A Hot‐Segment‐Based Approach for the Design of Cross‐Amyloid Interaction Surface Mimics as Inhibitors of Amyloid Self‐Assembly
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Dr. Erika Andreetto Dipl.‐Chem. Eleni Malideli Dr. Li‐Mei Yan Dipl.‐Ing. Michael Kracklauer MSc. Karine Farbiarz Dipl.‐Chem. Marianna Tatarek‐Nossol Prof. Dr. Gerhard Rammes M. Sc. Elke Prade Tatjana Neumüller Dr. Andrea Caporale M. Sc. Anna Spanopoulou B. Sc. Maria Bakou Prof. Dr. Bernd Reif Prof. Dr. Aphrodite Kapurniotu 《Angewandte Chemie (International ed. in English)》2015,54(44):13095-13100
The design of inhibitors of protein–protein interactions mediating amyloid self‐assembly is a major challenge mainly due to the dynamic nature of the involved structures and interfaces. Interactions of amyloidogenic polypeptides with other proteins are important modulators of self‐assembly. Here we present a hot‐segment‐linking approach to design a series of mimics of the IAPP cross‐amyloid interaction surface with Aβ (ISMs) as nanomolar inhibitors of amyloidogenesis and cytotoxicity of Aβ, IAPP, or both polypeptides. The nature of the linker determines ISM structure and inhibitory function including both potency and target selectivity. Importantly, ISMs effectively suppress both self‐ and cross‐seeded IAPP self‐assembly. Our results provide a novel class of highly potent peptide leads for targeting protein aggregation in Alzheimer’s disease, type 2 diabetes, or both diseases and a chemical approach to inhibit amyloid self‐assembly and pathogenic interactions of other proteins as well. 相似文献
19.
Eleni Kalogria Athanasia Varvaresou Spyridon Papageorgiou Evaggelia Protopapa Ioannis Tsaknis Alexios Matikas Irene Panderi 《Chromatographia》2014,77(19-20):1275-1281
This article describes the development and validation of a selective high-performance liquid chromatography method that allows, after liquid–liquid extraction and pre-column derivatization reaction with quercetin, the quantification of aluminium chlorohydrate in antiperspirant creams. Chromatographic separation was achieved on an XTerra MS C18 analytical column (150 × 3.0 mm i.d., particle size 5 μm) using a mobile phase of acetonitrile:water (15:85, v/v) containing 0.08 % trifluoroacetic acid at a flow rate of 0.30 mL min?1. Ultraviolet spectrophotometric detection at 415 nm was used. The assay was linear over a concentration range of 3.7–30.6 μg mL?1 for aluminium with a limit of quantitation of 3.74 μg mL?1. Quality control samples (4.4, 17.1 and 30.6 μg mL?1) in five replicates from five different runs of analysis demonstrated intra-assay precision (% coefficient of variation <3.8 %), inter-assay precision (% coefficient of variation <5.4 %) and an overall accuracy (% recovery) between 96 and 101 %. The method was used to quantify aluminium in antiperspirant creams containing 11.0, 13.0 and 16.0 % (w/w) aluminium chlorohydrate, respectively. 相似文献
20.
Eleni Kaditi Grigoris Mountrichas Stergios Pispas Author vitae 《European Polymer Journal》2011,(4):415-434
Anionic polymerization is the oldest known living/controlled polymerization methodology that leads to well defined macromolecules. It has been also used, with considerable success, for the synthesis of amphiphilic block copolymers (AmBC), a class of functional copolymers having interesting self-assembling properties and high potential for applications in various technological fields. The use of mild and effective post-polymerization functionalization/chemical modification reactions on block copolymers has substantially increased the synthetic capabilities of anionic polymerization methodologies, toward the creation of a variety of AmBC. In this feature article we review work done on these directions in the last ten years. Some perspectives and future work on this particular field of polymer science are also discussed. 相似文献