The Experts below are selected from a list of 63 Experts worldwide ranked by ideXlab platform
E. G. Afonin - One of the best experts on this subject based on the ideXlab platform.
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REDUCIBILITY OF DIPHENYLPHOSPHINIC ACID
CRI «Electronics», 2017Co-Authors: E. G. Afonin, G. G. Aleksandrov, A. L. IlinskiyAbstract:The phase homogeneity of diphenylphosphinic acid (С6H5)2PO2H purified by benzol or aqueous solution recrystallization is proved by X-ray powder diffraction analysis. The thermal behavior of the compound is studied by method of derivatography. The solubility of the compound in the multiple inorganic and organic solvents media is estimated. The results of experimental study of diphenylphosphinic acid decomposition in the reactions with oxidants of different chemical nature (nitric acid, permanganate, dichromate, vanadate, bismuthate, cerium (+4), hexacyanoferrate (+3), hydrogen peroxide, peroxydisulfate, Hypochlorite, Sodium benzenesulfonemonochloramide, bromate, periodate, iodate, manganese dioxide, lead dioxide) in aqueous media are given. Large amount of strong oxidant is required for breaking of both C–P chemical bonds in the molecule of diphenylphosphinic acid
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EXPERIMENTAL STUDY OF DIHEPTYLAND DIOCTYLPHOSPHINIC ACIDS REDUCIBILITY IN AQUEOUS MEDIA
CRI «Electronics», 2017Co-Authors: E. G. AfoninAbstract:The brief review of higher dialkylphosphinic acids applications and of solid metal(+2,+3,+4) dialkylphosphinates is given. The solubility of R2PO2H, R = C7H15, C8H17, in the multiple inorganic and organic solvents media is estimated (0,23 and 0,16 mol/l in 96% ethanol at 23 °C). The methods of crystallizational purification are presented. The results of experimental study of dialkylphosphinic acid decomposition in the reactions with oxidants of different chemical nature (permanganate, dichromate, vanadate, bismuthate, cerium(+4), hexacyanoferrate(+3), diperiodatocuprate(+3), diperiodatoargentate(+3), diperiodatonickelate(+4), sulfuric acid, nitric acid, hydrogen peroxide, peroxydisulfate, Hypochlorite, Sodium benzenesulfonemonochloramide, bromate, periodate, iodate, manganese dioxide, lead dioxide) in aqueous media are given. Large amount of strong oxidant is required for breaking of both C–P chemical bonds in the molecule of higher dialkylphosphinic acid
Paulo De Tarso Barbosa Sampaio - One of the best experts on this subject based on the ideXlab platform.
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ormosia excelsa benthseed asepsis for the initiation of an in vitro
BMC Proceedings, 2014Co-Authors: Daniel Da Silva, Flavio Mauro Souza Bruno, Angela Maria Imakawa, Nadia Raposo, Paulo De Tarso Barbosa SampaioAbstract:Ormosia excels Benth. is an Amazon medicinal plant popularly known as Tento amarelo which belongs to the Fabaceae family and is used in the treatment and prevention of diseases, once its seed extract is being tested to fight tooth decays[1]. It is also used in the timber industry to make cudgels, banks and canoes. Moreover, the seeds are often used in popular craftsworks [2-4]. The aim of this study was to develop an aseptic protocol to determine the best type and concentration of bactericidal and fungicidal agents for disinfection of seeds. The study was conducted at the College of Technology/University of Amazonas Plant Tissue Culture Lab, Manaus/AM where 90 Tento amarelo seeds were obtained from the Native Seed Amazon Center. They were washed with neutral ODD® detergent and rinsed with running water for a minute. Then, they were immersed in 0.2% (w/v) Derosal solution for an hour under 100 rpm constant orbital stirring, followed by a bath in a 70% ethanol solution for 1 minute and finally immersed in a Hypochlorite Sodium solution at 0.25%, 0.50% and 1.0% (w/v) concentrations respectively, for 30 minutes under the same stirring. Subsequently, the explants were washed three times with sterile distilled water and inoculated on MS sterile basal culture medium. After 30 days, the explants were evaluated for the presence or absence of fungi and bacteria, as well as their survival rate. The experimental design was completely randomized and statistical analysis used simple percentages. There was no statistically significant difference between treatments of Hypochlorite Sodium at 0.25% and 1.0% (w/v) concentrations, respectively since both provided the same level of alive and axenic explants (100%). It was observed that even with long period of exposure of the seeds to Hypochlorite Sodium and Derosal, these antimicrobial agents have been effective, since they are not toxic to the seeds of this kind. Even when exposed to high concentrations of these antimicrobial agents, the seeds remained alive and vigorous after germination. Treatments that present high and efficient decontamination effects are indicated for Tento amarelo seed asepsis as this species has a good performance for in vitro germination. We can come to the conclusion that it is possible to start an Ormosia excelsa Benth in vitro culture, from this asepsis.
A. L. Ilinskiy - One of the best experts on this subject based on the ideXlab platform.
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REDUCIBILITY OF DIPHENYLPHOSPHINIC ACID
CRI «Electronics», 2017Co-Authors: E. G. Afonin, G. G. Aleksandrov, A. L. IlinskiyAbstract:The phase homogeneity of diphenylphosphinic acid (С6H5)2PO2H purified by benzol or aqueous solution recrystallization is proved by X-ray powder diffraction analysis. The thermal behavior of the compound is studied by method of derivatography. The solubility of the compound in the multiple inorganic and organic solvents media is estimated. The results of experimental study of diphenylphosphinic acid decomposition in the reactions with oxidants of different chemical nature (nitric acid, permanganate, dichromate, vanadate, bismuthate, cerium (+4), hexacyanoferrate (+3), hydrogen peroxide, peroxydisulfate, Hypochlorite, Sodium benzenesulfonemonochloramide, bromate, periodate, iodate, manganese dioxide, lead dioxide) in aqueous media are given. Large amount of strong oxidant is required for breaking of both C–P chemical bonds in the molecule of diphenylphosphinic acid
Daniel Da Silva - One of the best experts on this subject based on the ideXlab platform.
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ormosia excelsa benthseed asepsis for the initiation of an in vitro
BMC Proceedings, 2014Co-Authors: Daniel Da Silva, Flavio Mauro Souza Bruno, Angela Maria Imakawa, Nadia Raposo, Paulo De Tarso Barbosa SampaioAbstract:Ormosia excels Benth. is an Amazon medicinal plant popularly known as Tento amarelo which belongs to the Fabaceae family and is used in the treatment and prevention of diseases, once its seed extract is being tested to fight tooth decays[1]. It is also used in the timber industry to make cudgels, banks and canoes. Moreover, the seeds are often used in popular craftsworks [2-4]. The aim of this study was to develop an aseptic protocol to determine the best type and concentration of bactericidal and fungicidal agents for disinfection of seeds. The study was conducted at the College of Technology/University of Amazonas Plant Tissue Culture Lab, Manaus/AM where 90 Tento amarelo seeds were obtained from the Native Seed Amazon Center. They were washed with neutral ODD® detergent and rinsed with running water for a minute. Then, they were immersed in 0.2% (w/v) Derosal solution for an hour under 100 rpm constant orbital stirring, followed by a bath in a 70% ethanol solution for 1 minute and finally immersed in a Hypochlorite Sodium solution at 0.25%, 0.50% and 1.0% (w/v) concentrations respectively, for 30 minutes under the same stirring. Subsequently, the explants were washed three times with sterile distilled water and inoculated on MS sterile basal culture medium. After 30 days, the explants were evaluated for the presence or absence of fungi and bacteria, as well as their survival rate. The experimental design was completely randomized and statistical analysis used simple percentages. There was no statistically significant difference between treatments of Hypochlorite Sodium at 0.25% and 1.0% (w/v) concentrations, respectively since both provided the same level of alive and axenic explants (100%). It was observed that even with long period of exposure of the seeds to Hypochlorite Sodium and Derosal, these antimicrobial agents have been effective, since they are not toxic to the seeds of this kind. Even when exposed to high concentrations of these antimicrobial agents, the seeds remained alive and vigorous after germination. Treatments that present high and efficient decontamination effects are indicated for Tento amarelo seed asepsis as this species has a good performance for in vitro germination. We can come to the conclusion that it is possible to start an Ormosia excelsa Benth in vitro culture, from this asepsis.
Montañez Izquierdo, Vanessa Yelina - One of the best experts on this subject based on the ideXlab platform.
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Métodos convencionales, rápidos y alternativos para el control microbiológico de la higiene en superficies
'Universitat Autonoma de Barcelona', 2013Co-Authors: Montañez Izquierdo, Vanessa YelinaAbstract:Las superficies contaminadas representan una de las principales vías de transmisión de microorganismos a lo largo de la cadena alimentaria, y se sitúan como el segundo factor más frecuente de contaminación cruzada de los alimentos. Dentro de la industria alimentaria, además de las superficies duras de trabajo (vidrio, metal y materiales poliméricos), la ropa del personal y otros materiales textiles (sintéticos y naturales) utilizados durante el procesado de los alimentos también son consideradas una fuente potencial para transferir microorganismos patógenos a los alimentos. Por tanto, el proceso de lavado de textiles debe poseer adicionalmente un efecto desinfectante. En este sentido, es necesario aplicar métodos que permitan un control microbiológico adecuado sobre ambos tipos de superficies, mediante el uso de herramientas para evaluar satisfactoriamente la contaminación y la aplicación de tratamientos, convencionales o alternativos, que disminuyan o eliminen de manera eficiente los microorganismos, principalmente cuando estos se encuentran dentro de un biofilm. Un método alternativo interesante para el control de la contaminación microbiana es el uso de bacteriófagos (fagos). En este estudio se comparó el método de cultivo convencional, la microscopía de epifluorescencia directa (DEM) y la PCR en tiempo real (RTi-PCR) para el recuento de Staphylococcus aureus sobre superficies textiles de algodón. El método que mostró mejor sensibilidad fue el cultivo (0,38 log10 UFC cm-2), seguido por la RTi-PCR (2,13 log10 UFC cm-2). Mientras que, la DEM presentó una sensibilidad menor (4,12 log10 UFC cm-2) y además resultó ser laboriosa para el recuento microbiológico en textiles. También, evaluamos el efecto desinfectante del lavado estándar sobre S. aureus y Candida albicans en superficies textiles a diferentes temperaturas con ocho agentes desinfectantes resultantes de la combinación de dos detergentes (Polvo y Líquido) y tres agentes blanqueadores. Los agentes desinfectantes base Polvo frente a sus respectivas combinaciones base Líquido, presentaron mejor efecto desinfectante. La adición de hipoclorito de sodio, como agente blanqueador, mejoró eficientemente el efecto bactericida y fungicida de ambos detergentes, incluso a temperatura ambiente. En tanto, la adición de percarbonato de sodio mostró mejor efecto desinfectante con el incremento de temperatura (a 40 °C). Por el contrario, la adición de peróxido de hidrógeno, no mejoró sustancialmente el grado de desinfección. Así, después del hipoclorito de sodio, el percarbonato de sodio se convierte en la mejor elección, ya que además presenta un menor impacto negativo al medio ambiente. Por último, se aplicó la DEM para evaluar la efectividad del fago P100 en el control de biofilms de Listeria monocytogenes sobre superficies de acero inoxidable. El fago P100 fue capaz de disgregar los biofilms a temperatura ambiente. Las mayores reducciones de L. monocytogenes en un menor tiempo se obtuvieron con concentraciones de fago mayores a 7 log10 UFP ml-1. El método de cultivo mostró reducciones del patógeno a niveles indetectables; sin embargo la tinción vital reveló la presencia de células viables, que representarían un riesgo de contaminación cruzada. El fago P100 puede proporcionar una medida adyuvante para controlar la contaminación de superficies de acero inoxidable con biofilms de L. monocytogenes. La DEM resultó ser una buena herramienta para evaluar rápida y adecuadamente el efecto del fago P100.Contaminated surfaces are one of the main routes of transmission of microorganisms throughout the food chain, and are placed as the second most common factor of cross-contamination. In food industry, besides hard surfaces (glass, metal, and organic polymeric materials), staff clothing and various textile materials (synthetic and natural) used during food processing are also considered a potential source to transfer pathogens to food. Therefore, the textile wash process should possess additionally disinfecting effect. In this regard, it is necessary to implement measures to enable an appropriate microbiological control on both types of surfaces, using tools to assess contamination successfully and applying treatments, conventional or alternative, to reduce or eliminate microorganisms efficiently, especially when these are located within a biofilm. An interesting alternative method for controlling microbial contamination is the use of bacteriophages (phages). In this study, the count of Staphylococcus aureus on cotton fabrics obtained by the conventional culture method, the Direct Epifluorescence Microscopic (DEM), and Real-Time PCR (RTi-PCR) were compared. The conventional culture method showed better sensitivity (0.38 log10 CFU cm-2), followed by RTi-PCR (2.13 log10 CFU cm-2). Whereas, DEM showed the lowest sensitivity (4.12 log10 UFC cm-2), and furthermore proved to be laborious for microbiological count in textile fabrics. Also, we evaluated the disinfection effect of standard washing on S. aureus and Candida albicans in textile fabrics at various temperatures with eight disinfectant agents resulting from combination of two detergents (Powder and Liquid) and three bleaching agents. Powder-based disinfectant agents generally showed higher disinfection effect than their respective combinations in Liquid-based. Adding Sodium Hypochlorite as a bleaching agent enhanced efficiently the bactericidal and fungicidal effect of both detergents even at room temperature. Meanwhile, addition of Sodium percarbonate improved the disinfectant effectiveness with increasing temperature (40 ° C). Conversely, the addition of hydrogen peroxide did not substantially improve the degree of disinfection of detergents. Therefore, after the Sodium Hypochlorite, Sodium percarbonate becomes the best choice, since it also has a less negative impact on the environment. Finally, DEM was applied to evaluate the effectiveness of phage P100 for controlling Listeria monocytogenes biofilms on stainless steel surfaces. Phage P100 was able to disaggregate the biofilms at room temperature. Greater reductions of L. monocytogenes in less time occurred using phages concentrations higher than 7 log PFU ml-1. Cultivation method showed pathogen reduction to undetectable levels; however vital staining revealed the presence of viable cells, which represent a risk of cross contamination. Our data suggest that the phage P100 may provide an adjuvant measure to control the contamination of stainless steel surfaces with L. monocytogenes biofilms. In this study, DEM was a good tool to quickly and accurately assess the effect of phage P100