scholarly journals Определение коэффициента диффузии растворов метиленового синего в дентине зуба человека с помощью спектроскопии отражения и их антибактериальная активность при лазерном воздействии-=SUP=-*-=/SUP=-

2019 ◽  
Vol 126 (6) ◽  
pp. 832
Author(s):  
А.А. Селифонов ◽  
О.Г. Шаповал ◽  
А.Н. Микеров ◽  
В.В. Тучин

The work is devoted to the determination of the diffusion coefficients of methylene blue in pure aqueous solution and in a micellar solution of a cationic surfactant in human tooth dentinal sections in vitro using diffuse reflectance optical spectroscopy and the free diffusion model. The determination of the diffusion coefficient of methylene blue for an aqueous solution is (6.74 ± 1.32) • 10−6 cm2/s and (1.93 ± 0.24) • 10−6 cm2/s for methylene blue in micellar solution. Studies of toxicity in daylight in the absence of laser radiation of methylene blue solutions in water and in solution of cetylpyridinium chloride, as well as the photodynamic effect of laser radiation (662 nm) on cells of Candida albicans, Staphylococcus aureus FDA 209P and Lactobacillus were carried out. The effect of laser radiation has a pronounced suppressive effect on all the studied microbial strains.

2008 ◽  
Vol 16 (4) ◽  
pp. 275-279 ◽  
Author(s):  
Evandro Watanabe ◽  
Juliane Maria Guerreiro Tanomaru ◽  
Andresa Piacezzi Nascimento ◽  
Fumio Matoba-Júnior ◽  
Mario Tanomaru-Filho ◽  
...  

Author(s):  
І. V. Yatsenko ◽  
◽  
I. V. Zabarna ◽  
N. M. Bogatko ◽  
K. A. Rodionova ◽  
...  

To search and use of alternative sources of animal protein is an urgent problem in Ukraine. In this aspect, snail meat is interesting, due to its nutritional value. Meat contains protein, essential vitamins and amino acids for humans, and does not contain cholesterol and unhealthy fats. There is no a comprehensive system for monitoring the safety and quality of snail meat in the system of state control of Ukraine for compliance with food legislation. Consequently, the question of determination of its safety, including and the degree of freshness is an urgent task. The method of determination of the level of freshness of snail meat, according to the content of the enzyme reductase with 0,1 % aqueous solution of methylene blue, was developed. This authors` approach is proposed both a qualitative and quantitative method to determine the degree of freshness of snail meat, according to other methods its safety determination. It has an advantage against existing methods because the safety of snail meat could be determine in different technological processing at different storage times by qualitative indicators of bacterial contamination of meat, depending on the level of freshness. According to the results of this method, it is able to obtain quantitative indicators of bacterial contamination of freshness of snail meat with the aim to determine its level. It was carried out that in fresh snail meat there is a discoloration in the meat extract after thermostating during 2,5 hours or it does not discolor (there is a stable blue color) – up to 103 CFU/g. In snail meat of dubious freshness, the meat extract is discolored in period from 40 minutes up to 2,5 h (104-105 CFU/g); in stale snail meat, discoloration of the meat extract is achieved in 20–40 minutes (106 CFU/g and more). The developed method of determination the freshness of snail meat according to the content of the enzyme reductase with 0,1% aqueous solution of methylene blue can be used in production laboratories at producing capacity for production, processing, sale and storage of snail meat, as well as in state laboratories of the State Food and Consumer Services of Ukraine. In addition, obtained data could make the basis for the development of normative documents in the system of state control over the safety of snail meat in Ukraine.


2009 ◽  
pp. 125-133 ◽  
Author(s):  
Eva Loncar ◽  
Miroslava Radeka ◽  
Snezana Petrovic ◽  
Andrea Skapin ◽  
Ognjen Rudic ◽  
...  

The photocatalytically active mesoporous coatings, based on titanium dioxide sols (Degussa), of the fired clay roofing tiles substrate were prepared by using poly(ethylene glycol) (PEG) M-600 and M-4000, as the structure directing agents. The coatings were deposited using spray technique followed by thermal treatment. Photocatalytic activity of the TiO2 coatings was evaluated by aqueous solution of methylene blue as model dye, deposited on the top of the coatings, after irradiation with UV light. The results were compared with the photocatalytic efficiency of some commercial self-cleaning products (clay roofing tiles, glass). The newly design coatings showed an interesting decolourisation performance (over 30 % after 24 h). It appeared that the procedure of photocatalytic activity determination, in the case of porous substrates, should be renewed by a preadsorption process.


Pharmacia ◽  
2020 ◽  
Vol 67 (2) ◽  
pp. 63-69
Author(s):  
Liliya Logoyda ◽  
Maksym Herasymiuk ◽  
Dariya Popovych ◽  
Svitlana Pidruchna ◽  
Vitaliy Hlushok ◽  
...  

Aim. An understanding of the role that transporters, in particular P-glycoprotein (P-gp), can play in the absorption, distribution, metabolism and excretion (ADME) of candidate drugs, and an assessment of how these processes might impact on toxicity and the potential for drug-drug interactions in the clinic, is required to support drug development and registration. It is therefore necessary to validate preclinical assays for the in vitro evaluation of candidate drugs as substrates or inhibitors of human P-gp. 2. A simple, rapid HPLC MS/MS method was developed for determination of verapamil hydrochloride from confluent Caco-2 monolayers and from aqueous solution. Materials and methods. Chromatography was achieved on Discovery C18, 50 × 2.1 mm, 5 μm column. Samples were chromatographed in a gradient mode (eluent A (acetonitrile – water – formic acid, 5 : 95 : 0.1 v/v), eluent B (acetonitrile – formic acid, 100 : 0.1 v/v)). The initial content of the eluent B is 0%, which increases linearly by 1.0 min to 100% and to 1.01 min returns to the initial 0%. The mobile phase was delivered at a flow rate of 0.4 mL/min into the mass spectrometer ESI chamber. The sample volume was 5 μl. Results. Under these conditions, verapamil hydrochloride was eluted at 1.08 min. A linear response function was established at 1 – 100 ng/mL. The regression equation for the analysis was Y = 0.0162x + 0.00391 with coefficient of correction (R2) = 0.9992. According to the Caco-2 test results, verapamil showed low permeability. It should be noted that the recovery value for verapamil hydrochloride is 102.69%. The within-run coefficients of variation ranged between 0.336% and 0.617% for verapamil. The within-run percentages of nominal concentrations ranged between 98.82% and 100.62% for verapamil. The between-run coefficients of variation ranged between 0.334% and 0.612% for verapamil. The between-run percentages of nominal concentrations ranged between 98.97% and 101.76% for verapamil. The assay values on both the occasions (intra- and inter-day) were found to be within the accepted limits. Conclusion. From results of analysis, it can be concluded that developed method is simple and rapid for determination of verapamil hydrochloride from confluent Caco-2 monolayers and from aqueous solution. Acquired results demonstrate that proposed strategy can be effortlessly and advantageously applied for examination of verapamil hydrochloride from Caco-2 cell monolayers.


1998 ◽  
Vol 61 (4) ◽  
pp. 469-475 ◽  
Author(s):  
FABIO GALVANO ◽  
AMEDEO PIETRI ◽  
TERENZIO BERTUZZI ◽  
ANDREA PIVA ◽  
LUIGI CHIES ◽  
...  

In vitro affinity tests were conducted to test the effectiveness of 19 activated carbons (ACs), hydrated sodium calcium aluminosilicate (HSCAS) and sepiolite (S) in binding ochratoxin A (OA) and deoxynivalenol (DON) from solution. Relationships between adsorption ability and physicochemical parameters of ACs (surface area, iodine number, methylene blue Index) were tested. When 5 ml of a 4-μg/ml aqueous solution of OA was treated with 2 mg of AC, the ACs adsorbed 0.80 to 99.86% of the OA. HSCAS and S were not effective in binding OA. In two saturation tests carried out with increased amounts of OA (5 ml of 10- and 50-μg/ml aqueous Solutions of OA, respectively), three ACs also showed high adsorption ability (adsorbing 92.23 to 96.57% of the OA). When 5 ml of a 4-μg/ml aqueous solution of DON was treated with 10 mg of AC, ACs adsored 1.83 to 98.93% of the DON. HSCAS and S were not effective in binding DON. An overall relation of adsorption ability to the physicochemical parameters of ACs was observed. The methylene blue index was more reliable than iodine number and surface area in predicting ability of ACs to adsorb OA and DON. Based on the data observed on the present study as well as on aflatoxin B1 and fumonisin B1 from previous studies, it is concluded that ACs have high in vitro affinity for chemically different mycotoxins, and can be considered as potential multi-mycotoxin-sequestering agents. However, the ability to bind the main mycotoxins singly or in combination should be confirmed by in vivo investigations. Moreover, information on the amounts of AC to be added to feeds, and on the possible long-term effect on absorption of essential nutrients are needed.


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