PHOSPHATE LOAD AS THE EVOLUTIONARY DRIVING FORCE FOR THE DEVELOPMENT OF A HIGH FILTRATION RATE BASED EXCRETORY ORGAN: A HYPOTHESIS

1993 ◽  
Vol 4 (1-2) ◽  
Author(s):  
A. Ilani
Keyword(s):  
Driving Force ◽  
Filtration Rate ◽  
Excretory Organ

Kidney function of the American eel Anguilla rostrata

1975 ◽  
Vol 228 (2) ◽  
pp. 420-431 ◽  
Author(s):  
B Schmidt-Nielsen ◽  
JL Renfro
Keyword(s):  
Driving Force ◽  
Filtration Rate ◽  
Distal Part ◽  
Distal Tubule ◽  
Fluid Secretion ◽  
Urine Flow ◽  
Water Reabsorption ◽  
American Eel ◽  
Ion Secretion ◽  
Urine Formation

Urine formation in the eel, acclimated to freshwater (FW) and seawater (SW) was studied. SW eels maintained higher plasma and urine osmotic and ionic concentrations than FW eels. Polyethylene-1,2-glycol-14C (PEG-14C) clearance was 29% greater than methoxy-inulin-3H clearance. PEG-14C clearance was considered to be the glomerular filtration rate (GFR). The GFR of SW and FW eels did not differ. Urine flow rate in SW eels was one-third of that in FW eels. The primary urinary solutes in both groups were Na and Cl. Apparently, tubular fluid secretion occurred in FW and, to a lesser degree, in SW eels. With the assumption that water reabsorption was secondary to Na reabsorption in the kidney, the clearance data were used to evaluate all possible explanations for what appeared to be fluid secretion. The data were inconsistent with the possibility that GFR had been underestimated due to glomerular sieving of PEG or active or passive reabsorption of the marker, but consistent with tubular fluid secretion. Furosemide caused diuresis in both groups of eels apparently by inhibition of Na reabsorption in the distal tubule, but it had no effect on the apparent tubular fluid secretion. Tubular ion secretion could not be conclusively implicated as a driving force for fluid secretion. However, the possibility of K, Ca, or Mg secretion in a proximal segment followed by reabsorption in a more distal part of the nephron was not ruled out.

In situ TEM Studies of agglomeration of sub-nanometer Ru layers in Ru/C multilayers

1992 ◽  
Vol 50 (1) ◽  
pp. 256-257
Author(s):  
Tai D. Nguyen ◽  
Ronald Gronsky ◽  
Jeffrey B. Kortright
Keyword(s):  
Layered Structure ◽  
Driving Force ◽  
High Energy ◽  
Superior Performance ◽  
In Situ Tem ◽  
Rayleigh Instability ◽  
Practical Applications ◽  
Transmission Electron ◽  
Diffraction Patterns

Nanometer period Ru/C multilayers are one of the prime candidates for normal incident reflecting mirrors at wavelengths < 10 nm. Superior performance, which requires uniform layers and smooth interfaces, and high stability of the layered structure under thermal loadings are some of the demands in practical applications. Previous studies however show that the Ru layers in the 2 nm period Ru/C multilayer agglomerate upon moderate annealing, and the layered structure is no longer retained. This agglomeration and crystallization of the Ru layers upon annealing to form almost spherical crystallites is a result of the reduction of surface or interfacial energy from die amorphous high energy non-equilibrium state of the as-prepared sample dirough diffusive arrangements of the atoms. Proposed models for mechanism of thin film agglomeration include one analogous to Rayleigh instability, and grain boundary grooving in polycrystalline films. These models however are not necessarily appropriate to explain for the agglomeration in the sub-nanometer amorphous Ru layers in Ru/C multilayers. The Ru-C phase diagram shows a wide miscible gap, which indicates the preference of phase separation between these two materials and provides an additional driving force for agglomeration. In this paper, we study the evolution of the microstructures and layered structure via in-situ Transmission Electron Microscopy (TEM), and attempt to determine the order of occurence of agglomeration and crystallization in the Ru layers by observing the diffraction patterns.

The nucleation of cavities at grain boundaries

1987 ◽  
Vol 45 ◽  
pp. 288-291
Author(s):  
P. J. Goodhew
Keyword(s):  
Surface Tension ◽  
Surface Energy ◽  
Grain Boundaries ◽  
Radiation Damage ◽  
Impurity Concentration ◽  
Driving Force ◽  
Nucleation And Growth ◽  
Phase Boundaries ◽  
Cavity Nucleation ◽  
Spherical Bubble

Cavity nucleation and growth at grain and phase boundaries is of concern because it can lead to failure during creep and can lead to embrittlement as a result of radiation damage. Two major types of cavity are usually distinguished: The term bubble is applied to a cavity which contains gas at a pressure which is at least sufficient to support the surface tension (2g/r for a spherical bubble of radius r and surface energy g). The term void is generally applied to any cavity which contains less gas than this, but is not necessarily empty of gas. A void would therefore tend to shrink in the absence of any imposed driving force for growth, whereas a bubble would be stable or would tend to grow. It is widely considered that cavity nucleation always requires the presence of one or more gas atoms. However since it is extremely difficult to prepare experimental materials with a gas impurity concentration lower than their eventual cavity concentration there is little to be gained by debating this point.

The driving force of craniopharyngioma growth

2014 ◽  
Vol 122 (03) ◽  
Author(s):  
C Stache ◽  
A Hölsken ◽  
SM Schlaffer ◽  
A Hess ◽  
M Metzler ◽  
...  
Keyword(s):  
Driving Force

Clinical Renal Function Testing by External Double Isotope Monitoring Technique

1971 ◽  
Vol 10 (01) ◽  
pp. 16-24
Author(s):  
J. Fog Pedersen ◽  
M. Fog Pedersen ◽  
Paul Madsen
Keyword(s):  
Renal Function ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Plasma Flow ◽  
Filtration Rate ◽  
Renal Plasma Flow ◽  
Correlation Coefficients ◽  
Feedback System ◽  
Effective Renal Plasma Flow ◽  
Advantages And Disadvantages

SummaryAn accurate catheter-free technique for clinical determination simultaneouslyof glomerular filtration rate and effective renal plasma flow by means of radioisotopes has been developed. The renal function is estimated by the amount of radioisotopes necessary to maintain a constant concentration in the patient’s blood. The infusion pumps are steered by a feedback system, the pumps being automatically turned on when the radiation measured over the patient’s head falls below a certain preset level and turned off when this level is again readied. 131I-iodopyracet was used for the estimation of effective renal plasma flow and125I-iothalamate estimation of the glomerular filtration rate. These clearances were compared to the conventional bladder clearances and good correlation was found between these two clearance methods (correlation coefficients 0.97 and.90 respectively). The advantages and disadvantages of this new clearance technique are discussed.

Failure to control inflammation as a driving force of symptoms and phenotype in the NSG mouse model of ulcerative colitis

2018 ◽  
Author(s):  
H Jodeleit ◽  
P Palamides ◽  
O Al-amodi ◽  
G Beikircher ◽  
S Schönthaler ◽  
...  
Keyword(s):  
Ulcerative Colitis ◽  
Mouse Model ◽  
Driving Force ◽  
Nsg Mouse
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