排序方式: 共有19条查询结果,搜索用时 15 毫秒
1.
Andreea Irina Barzic Iuliana Stoica Dana-Ortansa Dorohoi 《Journal of Macromolecular Science: Physics》2016,55(6):575-590
New drug delivery systems based on hydroxypropyl cellulose (HPC) and different percents of glucose were prepared and characterized to check their suitability as UV resistant patches. The spectral absorption properties of the HPC and HPC-glucose blends before and after UV irradiation were analyzed. The surface polarity and hydrophilicity were correlated with the morphology of the films and analyzed with respect to the UV exposure time and the embedded amount of glucose. The effects of UV radiation on in vitro evaluation of glucose release from the HPC films are reported. The mechanism involved in the drug release process, evaluated using the Korsmeyer-Peppas equation, was dependent on the introduced amount of glucose and less on the UV exposure time. A more polar, smoother, and less dense surface releases the glucose over larger periods of time, making the system with lower percents of glucose more adequate for the pursued purpose. 相似文献
2.
Carmen Felicia Dascălu Beatrice Carmen Zelinschi Dana Ortansa Dorohoi Alexandru Ioan Cuza 《光谱学快报》2013,46(6):378-382
The transmission factor of multilayer Wood filters containing quartz and rutile layers was simulated in order to avoid the experimental trials for obtaining optical filters with predicted transmission. The main refractive indices of uniaxial crystals—quartz and rutile—were interferometrically determined and Cauchy constants were obtained by simulation. The transmission factor of optical devices consisting of quartz and rutile layers was simulated using the Maple Program. 相似文献
3.
Diaconu I Melniciuc-Puică N Dorohoi D Aflori M 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2007,68(3):536-541
The birefringence of MBBA, determined from the channeled spectra, decreases when the wavelength increases, showing a normal dispersion. The changes induced by an external electrostatic field acting perpendicular on the nematic director in the birefringence values were evidenced. The birefringence increases with the electrostatic field intensity which enhances the preferential alignment by the big values of the electric dipole moments induced parallel to the long MBBA molecule. The main refractive indices were interferometrically measured for three visible monochromatic radiations and the birefringence values were concordant with those estimated from the channeled spectra. The main molecular polarizabilities were estimated. 相似文献
4.
Cezarina Morosanu Larisa Popescu Liviu Sacarescu Dana Ortansa Dorohoi Lacramioara Anca Oprica 《Molecular Crystals and Liquid Crystals》2020,698(1):38-45
AbstractThe biomedical applications of magnetic nanoparticles require the surface modification with organic, hydrophilic molecules, able to ensure the stability of the resulted colloidal suspensions. We present the quantum mechanical approach of two molecules developing stable interfaces with magnetic Co0.5Fe2.5O4 nanoparticles. Sodium oleate, and citric acid, ensuring steric and respectively electrostatic stabilization are comparatively analyzed. The roles of dipole moment and frontier orbitals energies were emphasized to better understanding of some interface phenomena for the optimization of magnetic nanoparticle suspension preparation. Further, practical yielding of colloidal Co0.5Fe2.5O4 nanoparticles by coating with sodium oleate and respectively with citric acid is discussed. 相似文献
5.
Andreea Irina Barzic Dan Gheorghe Dimitriu Dana Ortansa Dorohoi 《International Journal of Polymer Analysis and Characterization》2015,20(6):565-571
The proposed method of channeled spectrum employs the recorded channeled spectrum of an optical active polymer solution placed between two crossed polarizers. The approach allows the evaluation of the optical rotatory dispersion of poly(propylene oxide) in benzene. The specific rotation, circular birefringence, and dispersion parameter depend on the wavelengths of the maxima and minima from the channeled spectrum. 相似文献
6.
3‐(p‐Bromo‐phenyl)‐pyridazinium‐benzoyl methylid (BPPBM) participates in solution at 3 + 3 dipolar thermal dimerization that can be spectrally monitored by the extinction in its visible intramolecular charge transfer (ICT) band. The attenuation of ICT band intensity shows the decrease of the BPPBM concentration with the increasing of dimer concentration. The complex kinetics of light‐assisted dimerization process was studied taking into account that the thermodynamic equilibrium is reached after more than 24 h. On the basis of general order of reaction theory, we found that the dimerization reaction must be described as a multistep mechanism. The rate constants of the dimerization reactions in ethanol (k = 0.00897 s?1) and benzene (k = 0.00774 s?1) solutions were correlated with the BPPBM and dimer structural features established by using the HyperChem 5.02 simulation program package. A kinetic mechanism of 3 + 3 dipolar thermal dimerization for the studied ylid is proposed. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 230–239, 2008 相似文献
7.
Ion Hurjui Andrei Neamtu Valeria Harabagiu Dana Ortansa Dorohoi Loredana Liliana Hurjui 《Journal of solution chemistry》2018,47(9):1492-1502
1,6-Diphenyl-1,3,5-hexatriene is one of the most used fluorescent labels in cell membrane fluidity studies. However, its solubility in aqueous biological media is low and an initial solubilizing step is necessary. In this study, the authors present spectroscopic and computational results in order to explain the striking displacement observed in electronic spectra (absorption and fluorescence) in different solvents. The experimental results were correlated with those obtained by molecular dynamics simulations of multicomponent solutions, which revealed non-homogenous microscopic regions formation in the ternary aqueous DPH solutions. 相似文献
8.
Ana Cezarina Morosanu Andreea Celia Benchea Daniela Babusca Dana Ortansa Dorohoi 《Analytical letters》2017,50(17):2725-2739
ABSTRACTQuercetin was subjected to a quantum-mechanical analysis and energetic and electro-optic parameters were evaluated. A solvatochromic study was used to estimate the dipole moment of quercetin in the excited state and to determine the angle between the dipole moments of this molecule in the electronic states responsible for the visible absorption band. The contribution of each type of intermolecular interactions to the total spectral shift experimentally recorded in quercetin solution was also established in this study. 相似文献
9.
Daniela Babusca Larisa Popescu Liviu Sacarescu Dana Ortansa Dorohoi Dorina Creanga Lacramioara Anca Oprica 《Molecular Crystals and Liquid Crystals》2020,698(1):56-64
AbstractWe have designed an experimental study dedicated to silver nanotoxicity using a suspension of citrate-silver nanoparticles, obtained by photochemical reduction. Fine granularity of generally symmetrical shape nanoparticles were evidenced by tansmission electron microscopy. The localized surface plasmon resonance spectral band revealed the intensification of silver nanoparticle formation under UV exposure. The nanotoxicity of silver nanoparticles was tested on cereal sprouts by measuring the concentrations of chlorophylls and carotenes in the green tissue. The differences between control samples, supplied with distilled water and test samples, loaded with different volumes of silver nanoparticles suspension were analyzed statistically, and compared with literature reports. 相似文献
10.