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11.
Cristina Bucur Mihaela Badea Mariana Carmen Chifiriuc Coralia Bleotu Emilia Elena Iorgulescu Irinel Adriana Badea Maria Nicoleta Grecu Veronica Lazăr Oana-Irina Patriciu Dana Marinescu Rodica Olar 《Journal of Thermal Analysis and Calorimetry》2014,115(3):2179-2189
Novel complexes of M2LCl4·nH2O type (M:Ni, n = 4; M:Cu, n = 3 and M:Zn, n = 0; L: ligand resulted from 1,4-phenylenediamine, 3,6-diazaoctane-1,8-diamine and formaldehyde one-pot condensation) were synthesized and characterised by microanalytical, ESI–MS, IR, UV–Vis, 1H NMR and EPR spectra, magnetic data at room temperature and molar conductivities as well. The electrochemical behaviour of complexes was investigated by cyclic voltammetry. Simultaneous TG/DTA measurements were performed in order to evidence the thermal behaviour of the obtained complexes. Processes such as water elimination, fragmentation and oxidative degradation of the organic ligand as well as chloride elimination occurred during thermal decomposition. The antimicrobial assays demonstrate that the compounds exhibited good antibacterial activity, especially against S. aureus and E. coli strains, the most active being the copper(II) complex, which also exhibited the most prominent anti-biofilm effect, suggesting its potential use for the development of new antimicrobial agents. The biological activity was correlated with log P ow values. All complexes disrupt the membrane integrity of HCT 8 tumour cells. 相似文献
12.
Mihaela Badea Larisa Calu Mariana Carmen Chifiriuc Coralia Bleotu Alexandra Marin Sebastian Ion Gabriela Ioniţă Nicolae Stanică Luminiţa Măruţescu Veronica Lazăr Dana Marinescu Rodica Olar 《Journal of Thermal Analysis and Calorimetry》2014,118(2):1145-1157
A series of complexes of type [ML(CH3COO)(OH2)2] (M: Co, Ni; HL: 2-[(E)-1H-1,2,4-triazol-3-ylimino)methyl]phenol)) and [M2L2(CH3COO)2(OH2)n] (M: Cu, n = 2; M: Zn, n = 0) were synthesised by template condensation. The compounds were characterised with microanalytical, ESI–MS, IR, electronic, EPR spectra and magnetic data at room temperature. Based on the IR and ESI–MS spectra, a dinuclear structure with the acetate as bridge was proposed for Cu(II) and Zn(II) complexes. The dinuclear structure of Cu(II) complex is also consistent with both magnetic behaviour and EPR spectrum. The thermal analyses have evidenced processes as water elimination, acetate decomposition, as well as oxidative degradation of the Schiff base. The final decomposition product was the most stable metal oxide as indicated by powder X-ray diffraction. The cobalt and copper compounds exhibited a broad spectrum of antibacterial activity towards both planktonic and biofilm-embedded cells. The complexes exhibit a low cytotoxicity except for Cu(II) species that induces the early apoptosis for the HEp 2 cells. 相似文献
13.
Mihaela Badea Rodica Olar Dana Marinescu Gina Vasile 《Journal of Thermal Analysis and Calorimetry》2008,92(1):209-214
A series of new complexes with mixed ligands of the type [ML(C3H3O2)2]·nH2O (((1)
M=Mn, n=1; (2)
M=Co(II), n=2; (3)
M=Ni(II), n=4; (4)
M=Cu(II), n=1.5; (5)
M=Zn(II), n=0; L=3-amino-1,2,4-triazole and (C3H3O2)=acrylate anion) were synthesized and characterised by chemical analysis and IR data. In all complexes the 3-amino-1,2,4-triazole
acts as bridge while the acrylate acts as bidentate ligand except for complex (5) where it is found as unidentate. The thermal behaviour steps were investigated in nitrogen flow. The thermal transformations
are complex processes according to TG and DTG curves including dehydration, acrylate ion and 3-amino-1,2,4-triazole degradation
respectively. The final products of decomposition are the most stable metal oxides, except for complex (4) that leads to metallic copper. 相似文献
14.
Aliona Ghendov-Mosanu Daniela Cojocari Greta Balan Antoanela Patras Ildiko Lung Maria-Loredana Soran Ocsana Opri Elena Cristea Rodica Sturza 《Molecules (Basel, Switzerland)》2022,27(5)
The article focuses on the optimization of the extraction process of biologically active compounds (BAC) from grape marc—a by-product of the wine industry. The influence of temperature, specifically 30 °C, 45 °C and 65 °C, and ethanol concentration in solutions, specifically 0–96% (v/v) on the extraction yield of polyphenols, flavonoids, tannins and anthocyanins, were investigated. The composition of individual polyphenols, anthocyanins and organic acids, antioxidant activity (DPPH and ABTS) and CIELab chromatic characteristics of the grape marc extracts (GME), were characterized. The microbiostatic and microbicidal effects in direct contact of GME with pathogenic microorganisms, Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, were determined in vitro. The influence of extraction parameters on the total polyphenol content (TPC), total flavonoid content (TFC), tannin content (TC), total anthocyanin content (TAC) and their interdependencies were studied using information analysis. A mathematical model was developed on cubic spline functions. The analysis of individual compounds showed the presence of a wide range of flavonoids (procyanidin B2, procyanidin B1, hyperoside and quercetin), flavones (catechin), hydroxybenzoic acid derivatives (gallic, protocatechuic, p-hydroxybenzoic acids, m-hydroxybenzoic acid, syringic acid), hydroxycinic acid derivatives and ferulic acid methyl ester. The malvidol-3-glucoside was the main anthocyanin identified in the extract. A high amount of tartaric acid was also found. GME showed significant antimicrobial activity against Gram-positive bacteria and lower activity against Gram-negative bacteria. 相似文献
15.
Two proofs are given, one combinatorial, the other by character theory, for the identity, ∏λa1! a2! … an! = ∏λ1a12a2 … nan, where λ ranges over all partitions λ = (1a12a2 … nan) of n. The two demonstrations yield a simple proof of the known formula, det2T(n) = [∏λ1a12a2 … nan]2, where T(n) is the matrix formed by the character table of Sn. Finally a sufficient condition is given so that the permanent of T(n) is zero. 相似文献
16.
Closed kernel systems of the coalition matrix turn out to correspond to cones of games on which the core correspondence is
additive and on which the related barycentric solution is additive, stable and continuous. Different perfect cones corresponding
to closed kernel systems are described.
Received: December 2001/Revised: July 2002
RID="*"
ID="*" This note contains the new results, which were presented by the first author in an invited lecture at the XIV Italian
Meeting on Game Theory and Applications in Ischia, July 2001. The lecture was dedicated to Irinel Dragan on the occasion of
his seventieth birthday. 相似文献
17.
F. Le Normand C.S. Cojocaru O. Ersen L. Gangloff R. Alexandrescu I. Morjan 《Applied Surface Science》2007,254(4):1058-1066
Iron-based nanoparticles are prepared by a laser-induced chemical vapor deposition (CVD) process. They are characterized as body-centered Fe and Fe2O3 (maghemite/magnetite) particles with sizes ≤5 and 10 nm, respectively. The Fe particles are embedded in a protective carbon matrix. Both kind of particles are dispersed by spin-coating on SiO2/Si(1 0 0) flat substrates. They are used as catalyst to grow carbon nanotubes by a plasma- and filaments-assisted catalytic CVD process (PE-HF-CCVD). Vertically oriented and thin carbon nanotubes (CNTs) were grown with few differences between the two samples, except the diameter in relation to the initial size of the iron particles, and the density. The electron field emission of these samples exhibit quite interesting behavior with a low turn-on voltage at around 1 V/μm. 相似文献
18.
Valentina Uivarosi Mihaela Badea Rodica Olar Dana Marinescu Teodor Octavian Nicolescu George Mihai Nitulescu 《Journal of Thermal Analysis and Calorimetry》2011,105(2):645-650
Three new complexes with ligands belong to the fluoroquinolone class having the general formula [RuL2Cl2]Cl nH2O ((1) L: norfloxacin (nf), n = 4; (2) L: ciprofloxacin (cp), n = 3; (3) L: enrofloxacin (enro), n = 5) were synthesized and characterized by chemical analysis UV–Vis and IR spectroscopy. In all complexes fluoroquinolone
derivative acts as bidentate chelate ligand. The thermal behavior steps were investigated in synthetic air flow. The thermal
transformations are complex processes according to TG and DTG curves including dehydration, quinolone derivative degradation,
as well as RuCl3 conversion in RuO2. 相似文献
19.
Popescu C. Voicu I. Alexandrescu R. Morjan I. Dumitras D. Popescu M. Fatu D. 《Journal of Thermal Analysis and Calorimetry》1999,56(1):183-189
This paper reports on the synthesis of various iron oxides by the IR laser processing of different iron salts. X-ray diffraction
techniques were used to characterize the reaction products. Some differences in terms of crystallite size and isotropy between
these oxides and those obtained from the same salt by thermal means are described and explained.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
20.
Cristina R. Dias Rodica Zãvoianu M. Farinha Portela 《Reaction Kinetics and Catalysis Letters》2002,77(2):317-324
The acid-base properties of several NiMoO4 catalysts supported on two silicas and prepared by different methods have been studied by temperature-programmed desorption of NH3. The catalytic behavior in the oxidative dehydrogenation of isobutane for two NiMoO4 catalysts with different acid-base properties are compared. 相似文献