Effect of high pressure CO2 sorption on the stability of metalorganic framework MOF-177 at different temperatures

The silver particles were grown in situ on the surface of wood by the silver mirror method and modified with stearic acid to acquire a surface with superhydrophobic and antibacterial properties. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray energy spectroscopy (XPS) were used to analyze the reaction mechanism of the modification process. Scanning electron microscopy (SEM) and contact angle tests were used to characterize the wettability and surface morphology. A coating with a micro rough structure was successfully constructed by the modification of stearic acid, which imparted superhydrophobicity and antibacterial activity to poplar wood. The stability tests were performed to discuss the stability of its hydrophobic performance. The results showed that it has good mechanical properties, acid and alkali resistance, and UV stability. The durability tests demonstrated that the coating has the function of water resistance and fouling resistance and can maintain the stability of its hydrophobic properties under different temperatures of heat treatment.

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An assessment of methanolysis and other factors used in the analysis of carbohydrate-containing materials

Biochemical Journal ◽

10.1042/bj1251009 ◽

1971 ◽

Vol 125 (4) ◽

pp. 1009-1018 ◽

Cited By ~ 353

Author(s):

R. E. Chambers ◽

J. R. Clamp

Keyword(s):

Hydrochloric Acid ◽

Analytical Procedure ◽

Internal Standard ◽

Inorganic Contaminants ◽

Rotary Evaporation ◽

Silver Salts ◽

Methanolic Hydrochloric Acid ◽

Different Temperatures ◽

The Stability ◽

Analytical System

The stability of monosaccharides in methanolic hydrochloric acid of different strengths and at different temperatures was determined. They are generally stable for 24h in methanolic 1m- and 2m-hydrochloric acid at both 85°C and 100°C, but undergo considerable destruction in methanolic 4m- and 6m-hydrochloric acid at 100°C. Analysis of glycopeptides and oligosaccharides of known composition showed that release of carbohydrate was complete within 3h in methanolic 1m-hydrochloric acid at 85°C. Removal of methanolic hydrochloric acid by rotary evaporation resulted in considerable losses of monosaccharides, which could be prevented by prior neutralization. Methanolysis caused extensive de-N-acetylation of acetamidohexoses, so that a re-N-acetylation step is necessary in the analytical procedure. The addition of acetic anhydride for this purpose also prevented loss of internal standard by adsorption on the insoluble silver salts used in neutralization. Several trimethylsilylating agents were studied and suitable conditions are recommended. The effects on the analytical system of water and some common organic and inorganic contaminants are assessed.

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Effect of food processing on the antioxidant activity of flavones from Polygonatum odoratum (Mill.) Druce

Open Life Sciences ◽

10.1515/biol-2021-0010 ◽

2021 ◽

Vol 16 (1) ◽

pp. 92-101

Author(s):

Guanghui Xia ◽

Xinhua Li ◽

Zhen Zhang ◽

Yuhang Jiang

Keyword(s):

Antioxidant Activity ◽

High Pressure ◽

Food Processing ◽

Yeast Fermentation ◽

Pressure Treatment ◽

Processing Methods ◽

High Pressure Treatment ◽

Effect Of Food ◽

The Stability

Abstract Polygonatum odoratum (Mill.) Druce (POD) is a natural plant widely used for food and medicine, thanks to its rich content of a strong antioxidant agent called homoisoflavones. However, food processing methods could affect the stability of POD flavones, resulting in changes to their antioxidant activity. This study attempts to evaluate the antioxidant activity of POD flavones subject to different processing methods and determines which method could preserve the antioxidant activity of POD flavones. Therefore, flavones were extracted from POD samples, which had been treated separately with one of the four processing methods: extrusion, baking, high-pressure treatment, and yeast fermentation. After that, the antioxidant activity of the flavones was subject to in vivo tests in zebrafish embryos. The results show that yeast fermentation had the least disruption to the antioxidant activity of POD flavones, making it the most suitable food processing method for POD. By contrast, extrusion and high-pressure treatment both slightly weakened the antioxidant activity of the flavones and should be avoided in food processing. The research results provide a reference for the development and utilization of POD and the protection of its biological activity.

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Influence of study model, baseline catalytic concentrations and analytical system on the stability of serum alanine aminotransferase

Advances in Laboratory Medicine / Avances en Medicina de Laboratorio ◽

10.1515/almed-2020-0021 ◽

2020 ◽

Vol 1 (2) ◽

Author(s):

Josep Miquel Bauça ◽

Andrea Caballero ◽

Carolina Gómez ◽

Débora Martínez-Espartosa ◽

Isabel García del Pino ◽

...

Keyword(s):

Alanine Aminotransferase ◽

Experimental Models ◽

Individual Variability ◽

Serum Samples ◽

Multicentric Study ◽

Different Temperatures ◽

The Stability ◽

Analytical System ◽

Definition Of ◽

Analytical Platforms

AbstractObjectivesThe stability of the analytes most commonly used in routine clinical practice has been the subject of intensive research, with varying and even conflicting results. Such is the case of alanine aminotransferase (ALT). The purpose of this study was to determine the stability of serum ALT according to different variables.MethodsA multicentric study was conducted in eight laboratories using serum samples with known initial catalytic concentrations of ALT within four different ranges, namely: <50 U/L (<0.83 μkat/L), 50–200 U/L (0.83–3.33 μkat/L), 200–400 U/L (3.33–6.67 μkat/L) and >400 U/L (>6.67 μkat/L). Samples were stored for seven days at two different temperatures using four experimental models and four laboratory analytical platforms. The respective stability equations were calculated by linear regression. A multivariate model was used to assess the influence of different variables.ResultsCatalytic concentrations of ALT decreased gradually over time. Temperature (−4%/day at room temperature vs. −1%/day under refrigeration) and the analytical platform had a significant impact, with Architect (Abbott) showing the greatest instability. Initial catalytic concentrations of ALT only had a slight impact on stability, whereas the experimental model had no impact at all.ConclusionsThe constant decrease in serum ALT is reduced when refrigerated. Scarcely studied variables were found to have a significant impact on ALT stability. This observation, added to a considerable inter-individual variability, makes larger studies necessary for the definition of stability equations.

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