scholarly journals A Comparison of Calcium Aggregation and Ultracentrifugation Methods for the Preparation of Rat Brain Microsomes for Drug Metabolism Studies

Pharmacology ◽  
2021 ◽  
pp. 1-6
Author(s):  
Barent N. DuBois ◽  
Farideh Amirrad ◽  
Reza Mehvar
Keyword(s):  
Calcium Chloride ◽  
High Speed ◽  
Chloride Concentration ◽  
Microsomal Protein ◽  
Protein Yield ◽  
Aggregation Method ◽  
Low Speed ◽  
Adult Rat ◽  
Brain Microsomes

Preparation of brain microsomes by the calcium chloride aggregation method has been suggested as an alternative to the ultracentrifugation method. However, the effects of the calcium chloride concentration on the quality of the microsomal fractions are not known. Brain microsomes were prepared from the adult rat brains using the high-speed ultracentrifugation and low-speed calcium chloride (10–100 mM) aggregation methods (<i>n</i> = 5–6 per group). The microsomal protein yield (spectrometry), the cytochrome P450 reductase (CPR) activity (spectrometry), and the monooxygenase activities (UPLC-MS/MS) of CYP2D and CYP2E1 were determined in the obtained fractions. Increasing the concentrations of calcium chloride progressively increased the protein yield of the low-speed microsomal fractions. However, the increased yield was associated with a significant decrease in the activities of CPR, CYP2D, and CYP2E1. Additionally, the CYP2D and CYP2E1 activities were significantly correlated with the CPR activities of the fractions. In conclusion, when an ultracentrifuge is available, preparation of brain microsomes by the ultracentrifugation method might be preferable. However, the calcium aggregation method at a calcium chloride concentration of 10 mM is an acceptable alternative to the ultracentrifuge method.

scholarly journals Combination of mild heat and calcium chloride treatment on the texture and bioactive compounds of purple shallot

Food Research ◽  
2020 ◽  
Vol 4 (5) ◽  
pp. 1681-1687
Author(s):  
N.M. Thuy ◽  
N.T.M. Tuyen ◽  
N.V. Tai
Keyword(s):  
Water Temperature ◽  
Calcium Chloride ◽  
Bioactive Compounds ◽  
Chloride Concentration ◽  
Hot Water ◽  
Raw Material ◽  
Total Phenolic ◽  
Agricultural Crop ◽  
Mild Heat

Purple shallot (Allium ascalonicum L.) is one of the most tropical agricultural crop widely used as a food seasoning. It is a highly commercial and important commodity by the food industry, not only based on its economic value but also the bioactive compounds. Pretreatment is widely used before processing of agro-products to improve the quality of these products. In this study, the influences of the pretreatment were conducted by the combination of mild temperature ranging from 45 to 55°C and different concentrations of calcium chloride (from 0.25 to 0.75%) on the quality of raw purple shallot used for further study (e.g. freeze-drying and pickling). The samples were analyzed for the firmness, bioactive compounds (total phenolic, total flavonoid and quercetin content) and antioxidant activity. The results showed that mild water temperature and calcium chloride concentration were influent on the firmness and bioactive compounds of raw material. The addition of calcium can enhance the beneficial action of mild heat treatments on sensory properties of purple shallot. The optimal conditions of the process were stabilized with the desired function, obtained at 50°C of mild hot water temperature dipping and 0.64% of calcium chloride concentration.

Surface Quality of Finishing Cut by WEDM in Gas

2007 ◽  
Vol 24-25 ◽  
pp. 91-96
Author(s):  
Tong Wang ◽  
Xin Fu Zhang ◽  
Xue Fang Zhao ◽  
M. Kunieda
Keyword(s):  
Surface Quality ◽  
High Speed ◽  
Electrochemical Etching ◽  
Removal Rate ◽  
Low Speed ◽  
The Wire ◽  
High Removal Rate ◽  
Discharge Gap

This paper studies on a newly developed method, WEDM in gas, and discribes the features of finishing dry-WEDMed surface, such as narrower discharge gap length, higher surface straightness accuracy and no electrochemical etching actions. Low-speed WEDM removal rate in gas can be improved by increasing the wire winding speed. High-speed WEDM in gas has a significant advantage as high removal rate beyond the abovementioned good points, which is available for improving conventional high-speed WEDM quality.

Do You Name Speedy Objects Faster Than Slow Objects: SPEEDED NAMING OR NAMING SPEED? THE AUTOMATIC EFFECT OF OBJECT SPEED ON PERFORMANCE

2018 ◽  
Author(s):  
Moshe Shay Ben-Haim ◽  
Eran Chajut ◽  
Ran Hassin ◽  
Daniel Algom
Keyword(s):  
High Speed ◽  
Mental Representations ◽  
Reading Aloud ◽  
Naming Task ◽  
Naming Speed ◽  
Low Speed ◽  
Everyday Objects ◽  
Pictures And Words

we test the hypothesis that naming an object depicted in a picture, and reading aloud an object’s name, are affected by the object’s speed. We contend that the mental representations of everyday objects and situations include their speed, and that the latter influences behavior in instantaneous and systematic ways. An important corollary is that high-speed objects are named faster than low-speed objects despite the fact that object speed is irrelevant to the naming task at hand. The results of a series of 7 studies with pictures and words support these predictions.

scholarly journals Splatters and Aerosols Contamination in Dental Aerosol Generating Procedures

2021 ◽  
Vol 11 (4) ◽  
pp. 1914
Author(s):  
Pingping Han ◽  
Honghui Li ◽  
Laurence J. Walsh ◽  
Sašo Ivanovski
Keyword(s):  
Particle Size ◽  
Disease Transmission ◽  
High Speed ◽  
Low Speed ◽  
Dental Procedures ◽  
Dental Equipment ◽  
Produce Contamination ◽  
Fluorescein Dye ◽  
Filter Papers ◽  
Airborne Disease

Dental aerosol-generating procedures produce a large amount of splatters and aerosols that create a major concern for airborne disease transmission, such as COVID-19. This study established a method to visualise splatter and aerosol contamination by common dental instrumentation, namely ultrasonic scaling, air-water spray, high-speed and low-speed handpieces. Mock dental procedures were performed on a mannequin model, containing teeth in a typodont and a phantom head, using irrigation water containing fluorescein dye as a tracer. Filter papers were placed in 10 different locations to collect splatters and aerosols, at distances ranging from 20 to 120 cm from the source. All four types of dental equipment produced contamination from splatters and aerosols. At 120 cm away from the source, the high-speed handpiece generated the greatest amount and size (656 ± 551 μm) of splatter particles, while the triplex syringe generated the largest amount of aerosols (particle size: 1.73 ± 2.23 μm). Of note, the low-speed handpiece produced the least amount and size (260 ± 142 μm) of splatter particles and the least amount of aerosols (particle size: 4.47 ± 5.92 μm) at 120 cm. All four dental AGPs produce contamination from droplets and aerosols, with different patterns of distribution. This simple model provides a method to test various preventive strategies to reduce risks from splatter and aerosols.

High-Speed Imaging to Study an Auto-Oscillating Vocal Fold Replica for Different Initial Conditions

2017 ◽  
Vol 09 (05) ◽  
pp. 1750064 ◽  
Author(s):  
A. Van Hirtum ◽  
X. Pelorson
Keyword(s):  
Vocal Fold ◽  
High Speed ◽  
Initial Conditions ◽  
Vocal Folds ◽  
High Speed Imaging ◽  
Human Voice ◽  
Manual Intervention ◽  
Geometrical Features ◽  
Upstream Pressure

Experiments on mechanical deformable vocal folds replicas are important in physical studies of human voice production to understand the underlying fluid–structure interaction. At current date, most experiments are performed for constant initial conditions with respect to structural as well as geometrical features. Varying those conditions requires manual intervention, which might affect reproducibility and hence the quality of experimental results. In this work, a setup is described which allows setting elastic and geometrical initial conditions in an automated way for a deformable vocal fold replica. High-speed imaging is integrated in the setup in order to decorrelate elastic and geometrical features. This way, reproducible, accurate and systematic measurements can be performed for prescribed initial conditions of glottal area, mean upstream pressure and vocal fold elasticity. Moreover, quantification of geometrical features during auto-oscillation is shown to contribute to the experimental characterization and understanding.

Nonlinear transport of rarefied Couette flows from low speed to high speed

2020 ◽  
Vol 32 (11) ◽  
pp. 112021
Author(s):  
Jihui Ou ◽  
Jie Chen
Keyword(s):  
High Speed ◽  
Nonlinear Transport ◽  
Low Speed

scholarly journals Energy Absorption Characteristics of PVC Coarse Aggregate Concrete under Impact Load

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Shi Hu ◽  
Huaming Tang ◽  
Shenyao Han
Keyword(s):  
Compressive Strength ◽  
Energy Absorption ◽  
High Speed ◽  
Coarse Aggregate ◽  
Specific Energy Absorption ◽  
Low Speed ◽  
High Speed Impact ◽  
Aggregate Content ◽  
Dynamic Compressive Strength ◽  
Absorption Characteristics

AbstractIn this paper, polyvinyl chloride (PVC) coarse aggregate with different mixing contents is used to solve the problems of plastic pollution, low energy absorption capacity and poor damage integrity, which provides an important reference for PVC plastic concrete used in the initial support structures of highway tunnels and coal mine roadway. At the same time, the energy absorption characteristics and their relationship under different impact loads are studied, which provides an important reference for predicting the energy absorption characteristics of concrete under other PVC aggregate content or higher impact speed. This study replaced natural coarse aggregate in concrete with different contents and equal volume of well-graded flaky PVC particles obtained by crushing PVC soft board. Also, slump, compression, and splitting strength tests, a free falling low-speed impact test of steel balls and a high-speed impact compression test of split Hopkinson pressure bar (SHPB) were carried out. Results demonstrate that the static and dynamic compressive strength decreases substantially, and the elastic modulus and slump decrease slowly with the increase of the mixing amount of PVC aggregate (0–30%). However, the energy absorption rate under low-speed impact and the specific energy absorption per MPa under high-speed impact increase obviously, indicating that the energy absorption capacity is significantly enhanced. Regardless of the mixing amount of PVC aggregate, greater strain rate can significantly enhance the dynamic compressive strength and the specific energy absorption per MPa. After the uniaxial compression test or the SHPB impact test, the relative integrity of the specimen is positively correlated with the mixing amount of PVC aggregate. In addition, the specimens are seriously damaged with the increase of the impact strain rate. When the PVC aggregate content is 20%, the compressive strength and splitting strength of concrete are 33.8 MPa and 3.26 MPa, respectively, the slump is 165 mm, the energy absorption rate under low-speed impact is 89.5%, the dynamic compressive strength under 0.65 Mpa impact air pressure is 58.77 mpa, and the specific energy absorption value per MPa is 13.33, which meets the requirements of shotcrete used in tunnel, roadway support and other impact loads. There is a linear relationship between the energy absorption characteristics under low-speed impact and high-speed impact. The greater the impact pressure, the larger the slope of the fitting straight line. The slope and intercept of the fitting line also show a good linear relationship with the increase of impact pressure. The conclusions can be used to predict the energy absorption characteristics under different PVC aggregate content or higher-speed impact pressure, which can provide important reference for safer, more economical, and environmental protection engineering structure design.

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