Silicone Elastomer Uptake Method for Determination of Free 1‐Alkyl‐2‐Pyrrolidone Concentration in Micelle and Hydroxypropyl‐β‐Cyclodextrin Systems Used in Skin Transport Studies

2008 ◽  
Vol 97 (1) ◽  
pp. 368-380 ◽  
Author(s):  
Kevin S. Warner ◽  
Dalia S. Shaker ◽  
Sarah Molokhia ◽  
Qingfang Xu ◽  
Jinsong Hao ◽  
...  
Keyword(s):  
Silicone Elastomer ◽  
Transport Studies ◽  
Skin Transport ◽  
Uptake Method

scholarly journals Determination of 2D poloidal maps of the intrinsic W density for transport studies in JET-ILW

2018 ◽  
Vol 89 (11) ◽  
pp. 113501 ◽  
Author(s):  
Marco Sertoli ◽  
Joanne Flanagan ◽  
Mikhail Maslov ◽  
Costanza Maggi ◽  
Ivor Coffey ◽  
...  
Keyword(s):  
Transport Studies

BIOASSAY OF SEAWATER: I. A 14C UPTAKE METHOD FOR THE DETERMINATION OF CONCENTRATIONS OF VITAMIN B12 IN SEAWATER

1966 ◽  
Vol 12 (1) ◽  
pp. 175-183 ◽  
Author(s):  
A. F. Carlucci ◽  
S. B. Silbernagel
Keyword(s):  
Internal Standard ◽  
Natural Seawater ◽  
Centric Diatom ◽  
Inhibitory Effects ◽  
Internal Standards ◽  
Sterile Medium ◽  
Seawater Samples ◽  
C Assimilation ◽  
Uptake Method

A method is described employing 14CO2 uptake by the marine centric diatom Cyclotella nana (clone 13-1) for the bioassay of vitamin B12 in seawater. Seawater samples were filter sterilized, supplemented with sterile medium constituents, and diluted with a similarly supplemented, charcoal-treated filtered seawater. Samples or diluted samples, internal standards, and external standards were inoculated with the diatom such that the initial concentration of cells was approximately 1 × 104 per milliliter. The bioassay flasks were incubated for 47 hours, 14C as Na214CO2 was added, and 14C assimilation was measured after a 2-hour exposure. The rate of uptake of 14C could be related to B12 concentrations when these were in the range of 0.05 to 3.0 μμg B12 per milliliter. A 49-hour incubation time was selected since cells required time to adapt to seawaters collected from different locations. The concentration of B12 in a seawater sample was calculated from the radiocarbon uptake, the percentage of the internal standard recovered, and the dilution factor. The method is more sensitive than that described by Gold from which it was derived, and takes into account the serious inhibitory effects found in many samples of natural seawater. The limit of sure detection is about 0.05 μμg B12 per ml and the standard deviation of the method was about 0.3 μμg per ml when measuring 1.4 μμg B12 per ml in inhibitory seawater.

A simple method for evaluation of Rb+ transport and Na(+)-K+ pump stoichiometry in adherent cells

1991 ◽  
Vol 260 (6) ◽  
pp. C1341-C1346 ◽  
Author(s):  
N. Longo ◽  
L. D. Griffin ◽  
L. J. Elsas
Keyword(s):  
Simultaneous Determination ◽  
Human Fibroblasts ◽  
Flame Photometry ◽  
Adherent Cells ◽  
Experimental Conditions ◽  
Simple Method ◽  
Cultured Fibroblasts ◽  
Transport Studies ◽  
Transport Inhibitors

This report describes a method based on flame photometry for the evaluation of transmembrane Rb+ transport and Na(+)-K+ pump stoichiometry in adherent cells. In monolayers of cultured fibroblasts, the rates of 86Rb+, an isotope widely used as a K+ congener in transport studies, and nonradioactive Rb+ influx were equivalent when measured in the absence and presence of the transport inhibitors ouabain and bumetanide. Ouabain- and bumetanide-sensitive Rb+ fluxes were also equal with the two methods. Flame photometry allowed the simultaneous determination of intracellular [Na+] in the same sample in which Rb was measured. The incubation of human fibroblasts with ouabain for 5 min promoted a significant increase in intracellular [Na+]. Under appropriate experimental conditions, the ratio between the rate of ouabain-promoted increase in intracellular [Na+] and ouabain-sensitive Rb+ influx was 1.4, close to the theoretical value of 1.5 corresponding to a Na(+)-K+ pump stoichiometry of 3 Na+ extruded from the cell in exchange for 2 K+.

scholarly journals The Origin–Destination Matrix Development

2019 ◽  
Vol 290 ◽  
pp. 06010
Author(s):  
Vasile Dragu ◽  
Eugenia Alina Roman
Keyword(s):  
Factor Model ◽  
Stage Structure ◽  
Decision Making Process ◽  
Transport Models ◽  
Second Stage ◽  
Transport Studies ◽  
System Requirements ◽  
Actual Mobility

Transport studies are conducted for a better understanding of the actual mobility and for developing transport forecasting models to predict the future transport demand and the changes in travel patterns. Transport planning involves the decision-making process for potential improvements to a community’ s roadway infrastructure. The first transport models used to analyze globally the transport system requirements while nowadays models were rethought as a demand – supply interaction reflecting the correlation between transport and socio-economic development. The transport forecasting methodology use a four stage structure consisting of: trip generation, trip distribution, modal split, traffic assignment. In the second stage of the model, the generated trips for each zone are distributed to all other zones based on the choice of destination. The trip pattern is represented by means of an origin-destination (O-D) matrix. The Growth Factor Model and the Gravity Model are two methods to distribute trips among destinations. The two methods for developing the O-D Matrix are presented and criticized in this paper, showing the similarities and differences between them and highlighting the implications for rigorous determination of future transport demand. A case study is done to emphasize the differences between these models and their implications in carrying out transport studies.

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