Rubber and plastics hoses. Determination of ultra-violet resistance under static conditions

1989 ◽  
Keyword(s):  
Ultra Violet ◽  
Static Conditions

scholarly journals Na delivery and ENaC mediate flow regulation of collecting duct endothelin-1 production

2012 ◽  
Vol 302 (10) ◽  
pp. F1325-F1330 ◽  
Author(s):  
Meghana M. Pandit ◽  
Kevin A. Strait ◽  
Toshio Matsuda ◽  
Donald E. Kohan
Keyword(s):  
Plasma Membrane ◽  
Collecting Duct ◽  
Extracellular Fluid ◽  
Na Channel ◽  
Endothelin 1 ◽  
Flow Response ◽  
Mrna Content ◽  
Static Conditions ◽  
Biologic System

Collecting duct (CD) endothelin-1 (ET-1) is an important autocrine inhibitor of Na and water transport. CD ET-1 production is stimulated by extracellular fluid volume expansion and tubule fluid flow, suggesting a mechanism coupling CD Na delivery and ET-1 synthesis. A mouse cortical CD cell line, mpkCCDc14, was subjected to static or flow conditions for 2 h at 2 dyn/cm2, followed by determination of ET-1 mRNA content. Flow with 300 mosmol/l NaCl increased ET-1 mRNA to 65% above that observed under static conditions. Increasing perfusate osmolarity to 450 mosmol/l with NaCl or Na acetate increased ET-1 mRNA to ∼184% compared with no flow, which was not observed when osmolarity was increased using mannitol or urea. Reducing Na concentration to 150 mosmol/l while maintaining total osmolarity at 300 mosmol/l with urea or mannitol decreased the flow response. Inhibition of epithelial Na channel (ENaC) with amiloride or benzamil abolished the flow response, suggesting involvement of ENaC in flow-regulated ET-1 synthesis. Aldosterone almost doubled the flow response. Since Ca2+ enhances CD ET-1 production, the involvement of plasma membrane and mitochondrial Na/Ca2+ exchangers (NCX) was assessed. SEA0400 and KB-R7943, plasma membrane NCX inhibitors, did not affect the flow response. However, CGP37157, a mitochondrial NCX inhibitor, abolished the response. In summary, the current study indicates that increased Na delivery, leading to ENaC-mediated Na entry and mitochondrial NCX activity, is involved in flow-stimulated CD ET-1 synthesis. This constitutes the first report of either ENaC or mitochondrial NCX regulation of an autocrine factor in any biologic system.

scholarly journals II. The wave-lengths of A, a , and of prominent lines in the infra-red of the solar spectrum

1883 ◽  
Vol 36 (228-231) ◽  
pp. 137-138
Keyword(s):  
Solar Spectrum ◽  
Ultra Violet ◽  
Infra Red

M. Fievez has recently sent me a map of the solar spectrum from C to A* inclusive, and as part of this region is one which I have been measuring, I have examined the new publication with great interest. Photography and eye measurements do not exactly coincide in the detail of the grouping of the little a group as far as A, and A itself is shown by M. Fievez’s map as wanting some details which appear in the photographs. Thus in the photographs there are some seventeen lines, whilst in M. Fievez’s map there are but thirteen. Between A and a there are several lines of marked intensity in the photograph which are not shown in the new map. The wave-lengths of the different lines from above “ a ” to A are not the same as those given by Fievez, when they are taken from comparison photo-graphs of the 1st order of the red and 2nd of the ultra-violet on the same plate, or when checked by photographs of the 2nd order of the red with the 3rd order of the green taken in a similar manner. In my paper, “Phil. Trans.,” Part II, 1880, I gave a method of using mirrors by which this could be effected, but since Professor Rowland introduced his concave gratings this is much more readily carried out. He has kindly furnished me with gratings for the purpose, having about 14,400 lines to the inch, with focal distances of 7 feet 6 inches and 12 feet 6 inches respectively. These have been employed in determining the wave-lengths of this part of the spectrum. Cornu’s map was used as a reference for the ultra-violet wave-lengths, and Ångström’s map for those in the blue and green. The two maps may be taken as equally exact. The determination of A has been made by Maseart, Smyth, and others, besides Ångström and Langley, with discordant results. I think the above may be taken as accurate as are Cornu’s and Ångström maps.

scholarly journals Bioanalytical Method Development and Validation for Determination of Sulfasalazine in Rabbit Plasma by HPLC-UV

2021 ◽  
Vol 33 (7) ◽  
pp. 1692-1698
Author(s):  
S.S. Jadiya ◽  
N. Upmanyu ◽  
S. Arulmozhi ◽  
V. Jain ◽  
S. Sankaran ◽  
...  
Keyword(s):  
High Performance ◽  
Method Development ◽  
High Efficiency ◽  
Internal Standard ◽  
Ultra Violet ◽  
Precipitation Method ◽  
Pharmacokinetic Studies ◽  
Rabbit Plasma ◽  
Bioanalytical Method

In present study, an advanced, simple and a rapid reverse phase high performance liquid chromatography (RP-HPLC) method was developed for the quantitative determination of sulfasalazine in rabbit plasma. Sulfasalazine was separated using Chromatopak C-18 basic peerless (250 mm × 4.6 mm, 5μ) column in an isocratic mode using mobile phase consisting of the mixture of 10mM Ammonium acetate pH adjusted to 4.5 and acetonitrile (70:30 v/v) with a flow rate of about 1.0 mL/min at ambient temperature. An ultra-violet detection of sulfasalazine and the internal standard was carried out at 362 nm. Both sulfasalazine and internal standard (IS, 4-hydroxy benzoate) were extracted from plasma matrices with high efficiency using a simple protein precipitation method. The method was found to be highly selective with no carryover effects. Linearity of sulfasalazine was found with the range of 2.5-100 μg/mL with the value of r2 > 0.995 a correlation coefficient. At all three quality control levels, developed bioanalytical method was found as repeatable and reproducible as well. The average recoveries of sulfasalazine from plasma were in the range of 95.59-97.16%. The bioanalytical samples showed good and acceptable stability of sulfasalazine solution at different storage, packaging and handling conditions. Hence, in conclusion, the validated and developed HPLC-UV method could be effectively utilized for determination of sulfasalazine in pharmacokinetic studies involving novel formulations.

STUDIES ON THE DETERMINATION OF PENTOSANS BY ULTRA-VIOLET ABSORPTION SPECTRUM

1958 ◽  
Vol 14 (12) ◽  
pp. 914-919
Author(s):  
Masamichi Okubo ◽  
Koji Nakajima ◽  
Takuji Yoshiwara
Keyword(s):  
Absorption Spectrum ◽  
Ultra Violet

Rocket Determination of the Ultra-Violet Reflectivity of the Moon

1967 ◽  
Vol 1 (1) ◽  
pp. 11-11 ◽  
Author(s):  
J. H. Carver ◽  
B. H. Horton
Keyword(s):  
Wavelength Range ◽  
Full Moon ◽  
Ultra Violet ◽  
Lunar Phase ◽  
Atmospheric Ozone ◽  
The Moon

We have used rocket-borne photometers to determine the ultra-violet flux of the full moon in the wavelength range 2400-2900A where atmospheric ozone prevents ground-based observations. The lunar fluxes determined in two rocket firings from Woomera on 9th December, 1965, and 30th August, 1966, are summarized in the Table. The results for the two firings have been corrected to full moon values on the assumption that the lunar phase law is the same at these ultra-violet wavelengths as it is in the visible.

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