scholarly journals Determination of the rheological properties of Matrigel for optimum seeding conditions in microfluidic cell cultures

AIP Advances ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 125332 ◽  
Author(s):  
K. I. W. Kane ◽  
E. Lucumi Moreno ◽  
C. M. Lehr ◽  
S. Hachi ◽  
R. Dannert ◽  
...  
Keyword(s):  
Rheological Properties ◽  
Cell Cultures

scholarly journals STUDY OF ANTI-VIRUS ACTIONS OF METABOLITES OF LACTOBACTERIA

2020 ◽  
Vol 73 (7) ◽  
pp. 1484-1488
Author(s):  
Svetlana V. Kalinichenko ◽  
Kristina V. Melentyevа ◽  
Hans Manee ◽  
Natalia V. Dubinina ◽  
Natalia V. Zvereva ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Antiviral Activity ◽  
Cell Cultures ◽  
Lactobacillus Rhamnosus ◽  
Culture Fluid ◽  
Probiotic Strain ◽  
Maximum Tolerated Dose ◽  
Clinical Strains ◽  
Coxsackie B

The aim: of the work was to study the antiviral activity of the metabolites of the probiotic strain Lactobacillus rhamnosus GG (LGG or ATCC 53103) regarding clinical strains of enteroviruses (Coxsackie B-5, ECNO21) isolated from the feces of intestinal infections. Materials and methods: The object of the study was substrate-dependent cell cultures of HeLa, Vero, Hep-2 lines. The titer of the virus was determined by the presence of a clear cytopathic action (CPA) in the monolayer infected cells of the virus. Results: Determination of the enteric virus infections activity in the culture fluid showed that in samples with the LGG metabolites, the infections activity of the clinical strains of enteroviruses decreased after 24 hours, at 1.5-1.7 (p <0.05) times, and after 96 hours in 3, 6 – 5,7 times (p <0,01). the processing of cell cultures by metabolites in the amount of 0.3 mg / ml contributed to a decrease in the titer of viruses by 2.77 ± 0.11 lg TCDD50 / cm3, 2.83 ± 0.11 lg TCD50 / cm3 and 2.94 ± 0.13 lg TCD50 / cm3 for Vero, HeLa and Hep-2 line cells in 24 hours. Conclusions: It has been experimentally determined that the maximum tolerated dose (MTD) of L. rhamnosus GG metabolites was 0.3 μg / ml for all cultures of cell lines. Determination of the antiviral activity of L. rhamnosus GG metabolites in clinical viruses of enteroviruses (Coxsackie B-5 and ECNO-21) showed a decrease in infection activity in 1.5-1.7 times, (p <0.05) of clinical trials in clinical trials enteroviruses.

Determination of Thermal Conductivity of Soils: A Need for Computing Heat Loss Through Buried Submarine Pipelines

1982 ◽  
Vol 22 (04) ◽  
pp. 558-562 ◽  
Author(s):  
P.C. Rawat ◽  
S.L. Agarwal
Keyword(s):  
Thermal Conductivity ◽  
Steady State ◽  
Crude Oil ◽  
Rheological Properties ◽  
Heat Loss ◽  
Experimental Results ◽  
Dry Density ◽  
Empirical Relationships ◽  
Thermal Conductivities

Abstract An important parameter required for computing heat loss through buried submarine pipelines transporting crude oil is the thermal conductivity of soils. This paper describes an apparatus designed for determination of the thermal conductivity of soils at the desired moisture/ density condition in the laboratory under steady-state conditions. Experimental results on the three soils studied show that thermal conductivity increases as dry density increases at a constant moisture content and that it increases as water content increases at constant dry density. These results confirm the trends isolated earlier by Kersten. The experimental results are compared with the available empirical relationships. Kersten's relation is observed to predict the thermal conductivity of these soils reasonably. The predictions from Makowski and Mochlinski's relation (quoted by Szilas) are not good but improve if the sum of silt and clay fractions is treated as a clay fraction in the computation. Introduction Submarine pipelines are used extensively for transporting crude oil from offshore to other pipelines offshore or onshore. These pipelines usually are steel pipes covered with a coating of concrete. They often are buried some depth below the mudline. The rheological properties of different crude oils vary, and their viscosities increase with a decrease in temperature. Below some temperature, the liquid oil tends to gel. Therefore, for efficient transportation, the crude must be at a relatively high temperature so that it has a low viscosity. The temperature of the soil/water system surrounding a submarine pipeline is usually lower than that of oil. This temperature difference induces heat to flow from the oil to the environment, and the temperature of the oil decreases as it travels along the length of the pipeline. One must ensure that this temperature reduction does not exceed desirable limits dictated by the rheological properties of oil and by the imperatives of efficient economic properties of oil and by the imperatives of efficient economic transportation. Thus the analytical problem is to predict the temperature of crude in the pipeline some distance away from the input station. To do so, knowledge of the overall heat transfer coefficient for the pipeline is required, for which, in turn, it is necessary to know the thermal conductivities of the oil, the pipeline materials and its coating, and the soil. This paper presents thermal conductivities of soils determined in the laboratory under steady-state conditions and also presents a comparison of the test results of three soils with values determined from existing empirical relationships. Literature Review Heat moves spontaneously from higher to lower temperatures. In a completely dry porous body, transmission of heat can take place not only by conduction through the solid framework of the body and the air in the pores but also by convection and radiation between the walls of a pore and by macro- and microdistillation. In soils, however, it can be ascribed essentially to conduction, a molecular phenomenon that can be expressed in terms of experimentally determined coefficients of conductivity or resistivity, although these actually may include microdistillation and other mechanisms. SPEJ p. 558

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