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71.
72.
The article describes a computational model for the simulation of the emergence of social structure or social order, respectively. The model is theoretically based on the theory of social typifying by Berger and Luckmann. It consists of interacting artificial actors (agents), which are represented by two neural networks, an action net, and a perception net. By mutually adjusting of their actions, the agents are able to constitute a self‐organized social order in dependency of their personal characteristics and certain features of their environment. A fictitious example demonstrates the applicability of the model to problems of extra‐terrestrial robotics. © 2007 Wiley Periodicals, Inc. Complexity 12: 41–52, 2007 相似文献
73.
Mihaela Carmen Balaban Cyril Chappaz-Gillot Olaf Fuhr Christian Roussel 《Tetrahedron》2009,65(18):3733-193
meso-Bromoporphyrins can be conveniently substituted by primary and secondary amines in a metal catalyst-free reaction which gives access to a large variety of meso-N-substituted derivatives. In some cases, considerable acceleration of this amination can be effected under microwave irradiation. The amino anchor on the porphyrin skeleton is useful for constructing novel self-assembling porphyrinoids as demonstrated by a single crystal X-ray analysis as well as stationary absorption and fluorescence spectroscopies. 相似文献
74.
Tibor Rozsa Mihaela Duma Laurian Vlase Ioana Ionuţ Adrian Pîrnău Brînduşa Tiperciuc Ovidiu Oniga 《Journal of heterocyclic chemistry》2015,52(4):999-1006
Thiazole and bisthiazole derivatives represent a prevalent scaffold in the antimicrobial drug discovery. Therefore, we have decided to synthesize some new series of 4,5′‐bisthiazoles. A total of 17 compounds were synthesized, their structural elucidation being based on elemental analysis (C,H,N,S) and spectroscopic data (MS and 1H NMR). Their in vitro antimicrobial activities were assessed against several Gram‐positive and Gram‐negative bacteria strains and also against one fungal strain (Candida albicans) using the difusimetric method. Some of the compounds showed modest to good antibacterial activity against Gram‐negative Escherichia coli and Salmonella typhimurium and Gram‐positive Staphylococcus aureus and Bacillus cereus bacterial strains. All of the synthesized compounds showed moderate to very good antifungal activity against C. albicans. 相似文献
75.
Mihaela Florentina Ursache Loredana Dumitraşcu Nicoleta Stănciuc 《高分子科学杂志,A辑:纯化学与应用化学》2017,54(5):316-322
Sea buckthorn is a natural food ingredient rich in carotenoids, tocopherols, sterols, flavonoids, lipids, vitamins, tannins and minerals. In this study, we investigated the themostability of the complex formed between α-lactalbumin (α-LA) with carotenoids from sea buckthorn berries extract (CSB) in the temperature range of 25°C to 100°C. The heat induced conformational changes of the α-LA-CSB complex were studied by using fluorescence and molecular modeling techniques. Phase diagram indicated the presence of more than one structurally distinct species as an indicator that temperature influenced the conformation of α-LA. Intrinsic fluorescence studies revealed that carotenoids trapped into the core of α-LA do not bind in locations close to tryptophan (Trp) residues. The synchronous spectra indicated that the interaction between α-LA and CSB had no apparent influence on the local conformation of Trp and tyrosine (Tyr) microenvironments within protein structure. Quenching studies with acrylamide showed that Trp residues had the highest exposure at 80°C, being least accessible to quencher at 60°C. In agreement with the fluorescence spectroscopy observations, the in silico analysis at single molecules level indicated a significant increase of 46.42 Å2 and 80.07 Å2 of the total accessible surface area of Trp and Tyr residues, respectively with the temperature increase from 25°C to 90°C. Concerning the thermodynamic properties of the α-LA-β-carotene model, the molecular modeling results indicate that the thermal treatment is not favorable for preserving the stability of the complex. 相似文献
76.
Peter?ConstantinEmail authorView authors OrcID profile Tarek?Elgindi Mihaela?Ignatova Vlad?Vicol 《Journal of Nonlinear Science》2017,27(1):197-211
We consider a model of electroconvection motivated by studies of the motion of a two-dimensional annular suspended smectic film under the influence of an electric potential maintained at the boundary by two electrodes. We prove that this electroconvection model has global in time unique smooth solutions. 相似文献
77.
Synthesis and Antimicrobial Activity of Some New N‐substituted‐5‐arylidene‐thiazolidine‐2,4‐diones
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Anca Stana Brînduşa Tiperciuc Mihaela Duma Laurian Vlase Ovidiu Crişan Adrian Pîrnău Ovidiu Oniga 《Journal of heterocyclic chemistry》2014,51(2):411-417
A total of 17 new N‐substituted derivatives ( 2b , 2c , 2d , 2e , 2f , 2g , 2h , 2i , 2j , 2k and 3b , 3c , 3d , 3e , 3f , 3g , 3h ) of 5‐((2‐phenylthiazol‐4‐yl)methylene) thiazolidine‐2,4‐dione ( 2a ) and 5‐(2,6‐dichloro‐ benzylidene)thiazolidine‐2,4‐dione ( 3a ) were synthesized. The structural elucidation of the newly synthesized compounds was based on elemental analysis and spectroscopic data (MS, 1H NMR, 13C NMR), and their antimicrobial activities were assessed in vitro against several strains of Gram‐positive and Gram‐negative bacteria and one fungal strain (Candida albicans) as growth inhibition diameter. Some of them showed modest to good antibacterial activity against Gram‐negative Escherichia coli and Salmonella typhimurium and Gram‐positive Staphylococcus aureus, Bacillus cereus, and Enterococcus fecalis bacterial strains, whereas almost all the compounds were inactive against Listeria monocytogenes. All of the synthesized compounds showed moderate to very good activity against C. albicans. 相似文献
78.
Alexandru C. Razus Liviu Birzan Mihaela Cristea Eugenia Andreea Dragu Anamaria Hanganu 《Monatshefte für Chemie / Chemical Monthly》2011,40(9):1271-1282
Abstract
Two synthesis strategies were used for the generation of azulene-1-yl diazenes substituted at C-3 with a phenyl-chalcogenyl moiety, the synthesis of azulenes substituted at C-3 followed by azo-coupling and azulene substitution at C-3 in azulene-azo dyes. The last synthetic route seems to give more satisfactory results for the synthesis of the desired chalcogenic derivatives. Another target of this study was to investigate the changes induced by the phenyl-chalcogenic substitution on the NMR and UV-vis spectra, and also to compare this effect with the one exerted by halogen atoms and by strongly electron donating groups such as AcNH or PhCOO. Whereas the latter groups exhibit a strong influence on the NMR and UV-vis spectra, PhS, PhSe, or PhTe groups as well as halogen atoms produce only a small effect because of the moderate change in electron distribution over the entire molecule. 相似文献79.
Simple and low cost biosensor based on screen-printed electrode for sensitive detection of some alkylphenols was developed, by entrapment of HRP in a nanocomposite gel based on single-walled carbon nanotubes (SWCNTs) and 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) ionic liquid. Raman and FTIR spectroscopy, CV and EIS studies demonstrate the interaction between SWCNTs and ionic liquid. The nanocomposite gel, SWCNT-[BMIM][PF6] provides to the modified sensor a considerable enhanced electrocatalytic activity toward hydrogen peroxide reduction. The HRP based biosensor exhibits high sensitivity and good stability, allowing a detection of the alkylphenols at an applied potential of −0.2 V vs. Ag/AgCl, in linear range from 5.5 to 97.7 μM for 4-t-octylphenol and respectively, between 5.5 and 140 μM for 4-n-nonylphenol, with a response time of about 5 s. The detection limit was 1.1 μM for 4-t-octylphenol, and respectively 0.4 μM for 4-n-nonylphenol (S/N = 3). 相似文献
80.
Silvestro L Gheorghe M Iordachescu A Ciuca V Tudoroniu A Rizea Savu S Tarcomnicu I 《Analytical and bioanalytical chemistry》2011,401(3):1023-1034
A new sensitive and fast quantitative analytical method for the simultaneous determination of clopidogrel, its main metabolite
clopidogrel carboxylic acid, and the newly described acyl glucuronide metabolite, in human plasma samples, is presented. The
analytical procedures (plasma storage, handling, and extract storage in the autosampler) were optimized in order to avoid
back-conversion; a known drawback in measurements of clopidogrel. Clopidogrel acyl glucuronide was confirmed as a major source
of back-conversion to the parent drug in the presence of methanol, and thorough stability experiments were carried out to
find the most appropriate conditions for an accurate analysis of clopidogrel and the two metabolites. The method was validated
by assessing selectivity, sensitivity, linearity, accuracy, and precision for all three analytes, in accordance to Food and
Drug Administration guidelines. Spiked quality controls in plasma as well as incurred samples were used to verify back-conversion
in the selected conditions, with results meeting European Medicines Agency acceptance criteria (concentrations within 80–120%
of the first reading). The method was then applied to a pharmacokinetic study, and for the first time, a pharmacokinetic curve
of clopidogrel acyl glucuronide in human plasma is presented. The concentrations ranged up to 1,048.684 ng/mL, with a mean
of 470.268 ng/mL, while clopidogrel had a mean C
max of 1.348 ng/mL; these orders of magnitude show how much the back-conversion of this metabolite may influence clopidogrel
quantification if it is not properly controlled. 相似文献