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81.
Valentina Grumezescu Irina Negut Rodica Cristescu Alexandru Mihai Grumezescu Alina Maria Holban Florin Iordache Mariana Carmen Chifiriuc Roger J. Narayan Douglas B. Chrisey 《Molecules (Basel, Switzerland)》2021,26(12)
Staphylococcus aureus (Gram-positive) and Pseudomonas aeruginosa (Gram-negative) bacteria represent major infectious threats in the hospital environment due to their wide distribution, opportunistic behavior, and increasing antibiotic resistance. This study reports on the deposition of polyvinylpyrrolidone/antibiotic/isoflavonoid thin films by the matrix-assisted pulsed laser evaporation (MAPLE) method as anti-adhesion barrier coatings, on biomedical surfaces for improved resistance to microbial colonization. The thin films were characterized by Fourier transform infrared spectroscopy, infrared microscopy, and scanning electron microscopy. In vitro biological assay tests were performed to evaluate the influence of the thin films on the development of biofilms formed by Gram-positive and Gram-negative bacterial strains. In vitro biocompatibility tests were assessed on human endothelial cells examined for up to five days of incubation, via qualitative and quantitative methods. The results of this study revealed that the laser-fabricated coatings are biocompatible and resistant to microbial colonization and biofilm formation, making them successful candidates for biomedical devices and contact surfaces that would otherwise be amenable to contact transmission. 相似文献
82.
Brito Ciro José Miarka Bianca García-Pastor Teresa Pérez Diego Ignácio Valenzuela Marins Joao Carlos Bouzas Sillero-Quintana Manuel 《Journal of Thermal Analysis and Calorimetry》2021,145(5):2467-2475
Journal of Thermal Analysis and Calorimetry - This study investigated the thermal skin (Tsk) response of lower limbs in older adults with or without osteoarthritis before and after a concurrent... 相似文献
83.
Martina Palomba Italo Franco Coelho Dias Ornelio Rosati Francesca Marini 《Molecules (Basel, Switzerland)》2021,26(11)
In recent years, vinyl selenones were rediscovered as useful building blocks for new synthetic transformations. This review will highlight these advances in the field of multiple-bond-forming reactions, one-pot synthesis of carbo- and heterocycles, enantioselective construction of densely functionalized molecules, and total synthesis of natural products. 相似文献
84.
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
85.
Marina Nídia Ferreira dos Santos Costa Marcos Antônio Pena Muniz Charles Alberto Brito Negrão Carlos Emmerson Ferreira da Costa Maria Louze Nobre Lamarão Luiz Morais José Otávio Carréra Silva Júnior Roseane Maria Ribeiro Costa 《Journal of Thermal Analysis and Calorimetry》2014,115(3):2269-2275
The Pracaxi oil—(Pentaclethra macroloba) contains high concentrations of fatty acids with emollient action that contribute to skin hydration. The use of this oil is supported by the utilization of natural resources thus enabling regional development and social contribution. The objective of this study was to characterize the P. macroloba oil by thermogravimetry (TG, DTG, and DTA), gas chromatography, Fourier transform infrared spectroscopy (FT-IR), and oxidation stability—Rancimat, aiming at the quality control of plant raw material. Three samples of crude oil sold by Amazon Oil Industry (Ananindeua, Pará, Brazil) were studied. The analysis of these oil samples showed different fatty acids, especially the behenic, oleic, linoleic, and lignoceric acids totalizing approximately 96 % of the grease composition and in smaller percentage arachidic, lauric, myristic, palmitic, and linolenic acids were found. The major acids have wide medicinal use. According to the TG/DTG curve, thermal stability was observed up to 220 °C, indicating a greater mass loss related to the dehydration and elimination of volatile substances. The thermal decomposition process occurred in the range of 430–450° C according to the DTG curve. The absorption spectrum in the infrared region (FT-IR) showed well-defined bands confirming the presence of functional groups present in the oil. Tests in a Rancimat have shown an induction period between 8 and 10 h demonstrating that the samples are in agreement with the standards required by ANP No. 14/2012 which requires at least 6 h of testing. 相似文献
86.
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
87.
Multivalent Recognition of Concanavalin A by {Mo132} Glyconanocapsules—Toward Biomimetic Hybrid Multilayers 下载免费PDF全文
Dr. Mihail Barboiu Dr. Zineb Mouline Dr. Mihaela Silion Erol Licsandru Prof. Bogdan C. Simionescu Dr. Eugene Mahon Dr. Mariana Pinteala 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(22):6678-6683
Herein, we consider Müller’s spherical, porous, anionic, molybdenum oxide based capsule, (NH4)42‐ [{(MoVI)MoVI5O21(H2O)6}12{MoV2O4(CH3COO)}30]?10 CH3COONH4? 300 H2O≡(NH4)42? 1 a ?crystal ingredients≡ 1 , {Mo132}, as an effective sugar‐decorated nanoplatform for multivalent lectin recognition. The ion‐exchange of NH4+ ions of 1 with cationic‐sugars, D ‐mannose‐ammonium chloride ( 2 ) or D ‐glucose‐ammonium chloride ( 3 ) results in the formation of glyconanocapsules (NH4)42?n 2 n? 1 a and (NH4)42?m 3 m? 1 a . The Mannose (NH4)42?n 2 n? 1 a capsules bind selectively Concanavalin A (Con A) in aqueous solution, giving an association avidity constant of ${K{{{\rm multi}\hfill \atop {\rm a}\hfill}}}$ =4.6×104 M ?1 and an enhancement factor of β=K${{{{\rm multi}\hfill \atop {\rm a}\hfill}}}$ /K${{{{\rm mono}\hfill \atop {\rm ass}\hfill}}}$ =21.9, reminiscent of the formation of “glycoside clusters” on the external surface of glyconanocapsule. The glyconanocapsules (NH4)42?n 2 n? 1 a and (NH4)42?m 3 m? 1 a self‐assemble in “hybrid multilayers” by successive layer‐by‐layer deposition of (NH4)42?n 2 n? 1 a or (NH4)42?m 3 m? 1 a and Con A. These architectures, reminiscent of versatile mimics of artificial tissues, can be easily prepared and quantified by using quartz crystal microgravimetry (QCM). The “biomimetic hybrid multilayers” described here are stable under a continual water flow and they may serve as artificial networks for a greater depth of understanding of various biological mechanisms, which can directly benefit the fields of chemical separations, sensors or storage‐delivery devices. 相似文献
88.
Exploring the Molecular Structure of Imidazolium–Silica‐Based Nanoparticle Networks by Combining Solid‐State NMR Spectroscopy and First‐Principles Calculations 下载免费PDF全文
Dr. Marie‐Alexandra Neouze Martin Kronstein Dr. Marco Litschauer Dr. Michael Puchberger Dr. Cristina Coelho Prof. Christian Bonhomme Prof. Christel Gervais Dr. Frederik Tielens 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(46):15188-15196
A DFT‐based molecular model for imidazolium–silica‐based nanoparticle networks (INNs) is presented. The INNs were synthesized and characterized by using small‐angle X‐ray scattering (SAXS), NMR spectroscopy, and theoretical ab initio calculations. 11B and 31P HETCOR CP MAS experiments were recorded. Calculated 19F NMR spectroscopy results, combined with the calculated anion–imidazolium (IM) distances, predicted the IM chain density in the INN, which was also confirmed from thermogravimetric analysis/mass spectrometry results. The presence of water molecules trapped between the nanoparticles is also suggested. First considerations on possible π–π stacking between the IM rings are presented. The predicted electronic properties confirm the photoluminescence emissions in the correct spectral domain. 相似文献
89.
We present a method to build potential energy surfaces with the correct permutational symmetry of identical atoms. It is explained and applied to an A $_2$ B $_2$ molecular system. This method allows us to use different reference geometries, which are often needed in large molecules. 相似文献
90.
Mariana Pokrass Doron Azulay Isaac Balberg Nurit Atar Raz Gvishi Menachem Nathan 《Journal of Sol-Gel Science and Technology》2014,70(3):517-527
Electrical properties of multi-walled carbon nanotubes (MWNTs)/hybrid-glass nanocomposites prepared by the fast-sol–gel reaction were investigated in light of percolation theory. A good correlation was found between the experimental results and the theory. We obtained a percolation threshold ? c = 0.22 wt%, and a critical exponent of t = 1.73. These values are reported for the first time for a silica-based system. The highest conductivity measured on the MWNT/hybrid-glass nanocomposites was σ ≈ 10?3(Ω cm)?1 for 2 wt% carbon nanotube (CNT) loading. The electrical conductivity was at least 12 orders of magnitude higher than that of pure silica. Electrostatic force microscopy and conductive-mode atomic force microscopy studies demonstrated conductivity at the micro-level, which was attributed to the CNT dispersed in the matrix. It appears that the dispersion in our MWNT/hybrid-glass system yields a particularly low percolation threshold compared with that of a MWNT/silica-glass system. Materials with electrical conductivities described in this work can be exploited for anti-static coating. 相似文献