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排序方式: 共有564条查询结果,搜索用时 15 毫秒
81.
Ioana Simon Piroska Virag Benjamin Salmon Viorica Tarmure Mihaela Baciut 《Analytical letters》2019,52(7):1097-1111
The objective of this study was to determine the molecular and biochemical changes in dental pulp stem cells (DPSCs) due to consecutive low-dose ionizing radiation exposures using label-free Raman micro-spectroscopy (RMS). Ionizing radiation produces biological damage leading to health effects of varying severity. The effects and subsequent health implications caused by exposure to low-dose radiation, such as diagnostic exposure, remain ambiguous. We identified Raman biomarkers characteristic to low-dose cone beam computed tomography (CBCT) irradiation of the DPSCs. The biomarkers were monitored inside the cells using the relative intensity distribution of the 785 and 1734?cm?1 bands. The control cells presented a higher relative intensity of the nucleic acid specific Raman bands, whereas the irradiated cells revealed an increased intensity of the lipid-induced bands. The results obtained in this study demonstrate the capability of RMS for the detection of cell response to diagnostic radiation dose levels. This may indicate the potential of the technique for future applications such as monitoring the radiation responses in pediatric patients suffering repeated radiological exposures. 相似文献
82.
Crisan Manuela Vlase Gabriela Plesu Nicoleta Petric Mihaela Croitor Lilia Kravtsov Victor Chumakov Yurii Bourosh Paulina Vlase Titus 《Journal of Thermal Analysis and Calorimetry》2018,132(1):343-351
Journal of Thermal Analysis and Calorimetry - In the present studies, the thermal behaviour of NaUO2BO3 has been investigated. This compound is a potential product of interaction between the... 相似文献
83.
Mihaela Dochia Dorina Chambre Simona Gavrilaş Cristian Moisă 《Journal of Thermal Analysis and Calorimetry》2018,132(3):1489-1498
The nature of the complexing agents used in the bioscouring process of cotton fabrics aiming to eliminate the non-cellulosic compounds (pectin, waxes, etc.) and to improve the hydrophilic and wetting properties influences the thermal behaviour and the FT-IR spectra of the textile materials. In this paper, we study the influence of the experimental conditions and complexing agent nature (sodium citrate or disodium EDTA salt) on the pectin elimination in bioscouring treatment of cotton fabric by FT-IR and TG/DTG/DTA analysis. The changes from FT-IR spectra of the specific bands (absorbance intensity at 2916, 2852, 1732 and 1640/1642 cm?1) were evaluated. The thermal behaviour of the investigated samples’ fabric by using TG/DTG/DTA analysis was studied at 30–600 °C temperature range, in air atmosphere. All samples showed three mass-loss steps due to the elimination of humidity, decomposition of the non-cellulosic and cellulosic components (main degradation stage of the samples) and thermo-oxidative decomposition of the formed degradation products. The Tonset values corresponding to the main decomposition step, the mass-loss values (%Δm) and the % residual mass (at 600 °C) were influenced by the complexing agent nature as well as the concentration and the action time of the commercial enzyme product. In addition, the calcium content of some samples treated with and without ultrasound was determined using atomic absorption spectroscopy method (AAS) in order to correlate the results with TG/DTG/DTA analysis. The obtained results have shown that the synergistic action of experimental conditions (enzyme concentration, pH, enzyme product action time, ultrasound) and the presence of sodium citrate as a biodegradable complexing agent led to the elimination of a higher amount of pectin from the cotton samples than that eliminated when using EDTA. 相似文献
84.
Calu Larisa Badea Mihaela Čelan Korošin Nataša Chifiriuc Mariana Carmen Bleotu Coralia Stanică Nicolae Silvestro Luigi Maurer Martin Olar Rodica 《Journal of Thermal Analysis and Calorimetry》2018,134(3):1839-1850
Journal of Thermal Analysis and Calorimetry - A novel series of complexes ML(ClO4)·nH2O (M: Co, Ni, Cu, Zn; HL: 2-[(E)-(1H-1,2,4-triazol-3-ylimino)methyl]phenol) have been synthesized and... 相似文献
85.
Nicoleta Petrea Răzvan Petre Andrada Pretorian Constantin Toader Vasile Şomoghi Florentina Neaţu Mihaela Florea Ştefan Neaţu 《Comptes Rendus Chimie》2018,21(3-4):339-345
The catalytic methanolysis of the chemical warfare nerve agents soman, sarin, and VX was investigated by using Cu or Zn complexes. Although VX withstood decontamination, the decomposition yield being around 96%, the soman and sarin deposited on different surfaces were almost fully destroyed under ambient conditions. The catalytic tests performed on a wide range of contaminated surfaces confirm the activity of the investigated catalytic systems, these complexes being suitable, from an economical point of view, for use in the formulation of a possible decomposition kit with military or civilian applicability. 相似文献
86.
Alberti A Benaglia M Guerra M Gulea M Macciantelli D Masson S 《Organic letters》2008,10(15):3327-3330
The direct EPR detection of thioacyl radicals has been reported only once, while thioacyl nitroxides remain an elusive species. We failed to detect the thioacyl radicals from two thioaldehydes and from phosphoryldithioformates but have obtained EPR evidence that thioacyl radicals react with 2-methyl-2-nitrosopropane to give thiocarbonyloxyaminyls rather than thioacyl nitroxides. The results of DFT calculations support this unexpected reactivity of thioacyls, while making questionable their previous EPR identification. 相似文献
87.
Adina Raducan Alexandra Olteanu Mihaela Puiu Dumitru Oancea 《Central European Journal of Chemistry》2008,6(1):89-92
The kinetics of the reaction between malachite green (MG) and sodium hydroxide (MG fading) was studied using a spectrophotometric
method in the presence of two cationic surfactants, cetyl-benzyl-dimethyl-ammonium chloride (CBDAC) and hexadecyl-trimethylammonium
bromide (HTAB) and one anionic surfactant, sodium dodecyl sulphate (SDS) at concentrations below and above critical micellar
concentrations. The cationic surfactants have a catalytic effect, while the anionic surfactant has an inhibitory effect on
the reaction. A kinetic model describing the influence of surfactant on reaction rate was developed. The results are discussed
on the basis of electrostatic and hydrophobic interactions between the kinetic micelles and malachite green.
相似文献
88.
89.
Balaban MC Eichhöfer A Buth G Hauschild R Szmytkowski J Kalt H Balaban TS 《The journal of physical chemistry. B》2008,112(17):5512-5521
The title dicyano compound was synthesized via cyanation and it self-assembles in nonpolar solvents giving red-shifted and broad absorption maxima just as the bacteriochlorophylls which are encountered in the light-harvesting organelles of early photosynthetic bacteria. In the crystal, stacks are formed through a hierarchic combination of pi-stacking and a CN-Zn electrostatic interaction. Push-pull 15-N,N-dialkylamino-5-cyano congeners could be obtained in high yields using a solvent- and catalyst-free direct amination of meso-bromoporphyrins. Importantly, the fluorescence of the self-assembled species due to the very orderly manner in which the chromophores are arranged is not entirely quenched and has a surprisingly long lifetime of over 1 ns. This lends hope of using the trapped energy in biomimetic hybrid solar cells. 相似文献
90.
Laura Mureşan Ruben Ronda Valera Ivo Frébort Ionel Catalin Popescu Elisabeth Csöregi Mihaela Nistor 《Mikrochimica acta》2008,163(3-4):219-225
A selective and sensitive method is presented for biogenic amines (BA) determination. The novelty consists in coupling a highly selective electrochemical biosensor to a weak acid cation-exchange column for online detection of amines. A bienzyme design, based on a recently isolated amine oxidase from grass pea and commercial horseradish peroxidase, was used for the biosensor construction. The enzymes were co-immobilized on the surface of a graphite electrode together with the electrochemical mediator (Os-redox polymer). The electrochemical detection was performed at a low applied potential (?50 mV vs. Ag/AgCl, KCl0.1 M), where biases from interferences are minimal. The separation and determination of six BA, with relevance in food analysis (tyramine, putrescine, cadaverine, histamine, agmatine and spermidine), were investigated. Irrespective of the BA nature, the amine oxidase-based biosensor showed a linear response up to 5 mM, and its sensitivity decreases in the following order: cadaverine, putrescine, spermidine, agmatine, histamine and tyramine. The approach was used to estimate the BA content in fish samples, after their extraction with methanesulfonic acid. 相似文献