Extrinsic (P32)/Intrinsic (P31) Phosphorus Clearance Ratio in Man

1954 ◽  
Vol 6 (1) ◽  
pp. 25-27 ◽  
Author(s):  
G østung
Keyword(s):  
Clearance Ratio

Experimental Measurements of the Flow and Heat Transfer of a Square Jet Impinging on an Array of Square Pin Fins

2002 ◽  
Author(s):  
Johnny S. Issa ◽  
Alfonso Ortega
Keyword(s):  
Heat Transfer ◽  
Thermal Resistance ◽  
Flow Behavior ◽  
Jet Impingement ◽  
Tip Clearance ◽  
Heat Sinks ◽  
Clearance Ratio ◽  
Cross Sectional ◽  
Pressure Loss Coefficient ◽  
Air Jet

An experimental investigation was conducted to explore the flow behavior, pressure drop, and heat transfer due to free air jet impingement on square in-line pin fin heat sinks (PFHS) mounted on a plane horizontal surface. A parametrically consistent set of aluminum heat sinks with fixed base dimension of 25 × 25 mm was used, with pin heights varying between 12.5 mm and 22.5 mm, and fin thickness between 1.5 mm and 2.5 mm. A 6:1 contracting nozzle having a square outlet cross sectional area of 25 × 25 mm was used to blow air at ambient temperature on the top of the heat sinks with velocities varying from 2 to 20 m/s. The ratio of the gap between the jet exit and the pin tips to the pin height, the so-called tip clearance ratio, was varied from 0 (no tip clearance) to 1. The stagnation pressure recovered at the center of the heat sink was higher for tall pins than short pins. The pressure loss coefficient showed a little dependence on Re, increased with increasing pin density, and pin diameter, and decreased with increasing pin height and clearance ratio. The overall base-to-ambient thermal resistance decreased with increasing Re number, pin density and pin diameter. Surprisingly, the dependence of the thermal resistance on the pin height and clearance ratio was shown to be mild at low Re, and to vanish at high Re number.

Net urate reabsorption in the Dalmatian coach hound with a note on automated measurement of urate in species with low plasma urate

1982 ◽  
Vol 60 (12) ◽  
pp. 1499-1504 ◽  
Author(s):  
B. Moulin ◽  
P. Vinay ◽  
N. Duong ◽  
A. Gougoux ◽  
G. Lemieux
Keyword(s):  
Glomerular Filtration Rate ◽  
Creatinine Clearance ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Progressive Reduction ◽  
Clearance Ratio ◽  
Plasma Urate ◽  
Urate Reabsorption ◽  
Dalmatian Dog ◽  
Pyrazinoic Acid

A progressive reduction of renal blood flow and glomerular filtration rate induced by the stepwise clamping of a Goldblatt clamp increases the urate over creatinine clearance ratio from 1.2 to 1.9 in normal urate-secreting Dalmatian dogs. These clearance data support the existence of a predominant postreabsorptive secretory flux of urate in the normal Dalmatian dog. In contrast, in Dalmatians loaded with pyrazinoic acid which suppresses urate secretion, net reabsorption of urate is unmasked and the urate over creatinine clearance ratio decreases with the progressive reduction in glomerular filtration rate (down to 0.44). It is concluded that the net reabsorption of urate measured by conventional clearance techniques after pharmacologic depression of the urate secretory flux probably reflects true urate reabsorption in the nephron of this species.

scholarly journals MYOHEMOGLOBINURIA

1941 ◽  
Vol 74 (3) ◽  
pp. 187-196 ◽  
Author(s):  
Charles L. Yuile ◽  
William F. Clark
Keyword(s):  
Molecular Weight ◽  
Plasma Concentration ◽  
Creatinine Clearance ◽  
Glomerular Filtration ◽  
Renal Clearance ◽  
Renal Excretion ◽  
Clearance Ratio ◽  
A Value ◽  
Blood Hemoglobin

When myohemoglobin is injected intravenously into dogs, in amounts ranging from 0.75 to 1.50 gm., it is rapidly eliminated from the plasma and approximately 65 per cent is excreted by the kidneys in from 1½ to 2½ hours. Myohemoglobin does not appear in the urine below a threshold plasma concentration which is slightly under 20 mg. per 100 cc. but above this level the rate of renal excretion is directly proportional to the plasma concentration. The maximum myohemoglobin/creatinine clearance ratio averages 0.58 contrasted with a value of 0.023 for blood hemoglobin. This indicates that the rate of renal clearance of myohemoglobin is twenty-five times more rapid than that of blood hemoglobin. Evidence is presented that the excretory mechanism is essentially similar for the two substances but that differences in molecular weight account for different rates of glomerular filtration.

The Optimum Groove Geometry for Spiral Groove Viscous Pumps

1990 ◽  
Vol 112 (2) ◽  
pp. 409-414 ◽  
Author(s):  
Yuichi Sato ◽  
Kyosuke Ono ◽  
Akihiko Iwama
Keyword(s):  
Differential Equation ◽  
Flow Rate ◽  
Groove Width ◽  
Design Parameters ◽  
Width Ratio ◽  
Maximum Pressure ◽  
Spiral Groove ◽  
Clearance Ratio ◽  
Viscous Pump ◽  
Outflow Rate

The optimum geometries of disk and cylindrical sprial groove viscous pumps to provide the maximum pressure or flow rate are investigated theoretically. The geometrical design parameters, such as the groove angle, groove to ridge clearance ratio, groove width ratio and ridge clearance ratio, are considered as functions of meridional coordinate. Results are obtained from the solution of a differential equation for the smoothed overall pressure distribution of a spiral groove viscous pump. It is found that outflow rate increases with the increase of groove to ridge clearance ratio λ, and that for each value of λ there exist “optimum” values of groove angle and groove width ratio, which give a maximum outflow rate. However, the increase of λ decreases the ridge clearance.

scholarly journals A novel CASR variant in a family with familial hypocalciuric hypercalcaemia and primary hyperparathyroidism

2020 ◽  
Vol 2020 ◽  
Author(s):  
Satyanarayana V Sagi ◽  
Hareesh Joshi ◽  
Jamie Trotman ◽  
Terence Elsey ◽  
Ashwini Swamy ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Primary Hyperparathyroidism ◽  
Organ Damage ◽  
Urinary Calcium ◽  
Interesting Case ◽  
List Type ◽  
Loss Of Function ◽  
Clearance Ratio ◽  
Hormone Levels ◽  
Severe Hypercalcaemia

Summary Familial hypocalciuric hypercalcaemia (FHH) is a dominantly inherited, lifelong benign disorder characterised by asymptomatic hypercalcaemia, relative hypocalciuria and variable parathyroid hormone levels. It is caused by loss-of-function pathogenic variants in the calcium-sensing receptor (CASR) gene. Primary hyperparathyroidism (PHPT) is characterised by variable hypercalcaemia in the context of non-suppressed parathyroid hormone levels. Unlike patients with FHH, patients with severe hypercalcaemia due to PHPT are usually symptomatic and are at risk of end-organ damage affecting the kidneys, bone, heart, gastrointestinal system and CNS. Surgical resection of the offending parathyroid gland(s) is the treatment of choice for PHPT, while dietary adjustment and reassurance is the mainstay of management for patients with FHH. The occurrence of both FHH and primary hyperparathyroidism (PHPT) in the same patient has been described. We report an interesting case of FHH due to a novel CASR variant confirmed in a mother and her two daughters and the possible coexistence of FHH and PHPT in the mother, highlighting the challenges involved in diagnosis and management. Learning points: Familial hypocalciuric hypercalcaemia (FHH) and primary hyperparathyroidism (PHPT) can coexist in the same patient. Urinary calcium creatinine clearance ratio can play a role in distinguishing between PHPT and FHH. Genetic testing should be considered in managing patients with PHPT and FHH where the benefit may extend to the wider family. Family segregation studies can play an important role in the reclassification of variants of uncertain significance. Parathyroidectomy has no benefit in patients with FHH and therefore, it is important to exclude FHH prior to considering surgery. For patients with coexisting FHH and PHPT, parathyroidectomy will reduce the risk of complications from the severe hypercalcaemia associated with PHPT.

scholarly journals Familial Hypocalciuric Hypercalcaemia (FHH): A Case Report

2018 ◽  
Vol 3 (09) ◽  
Author(s):  
Tivya Kulasegaran ◽  
Pranav Kumar
Keyword(s):  
Differential Diagnosis ◽  
Case Report ◽  
Parathyroid Hormone ◽  
Autosomal Dominant ◽  
Genetic Test ◽  
Calcium Sensor ◽  
Clearance Ratio ◽  
Autosomal Dominant Disorder ◽  
Casr Gene ◽  
Inactivating Mutation

Familial hypocalciuric hypercalcaemia (FHH) is a rare genetic autosomal dominant disorder, with 3 variants described. An inactivating mutation in the calcium sensor receptor (CASR) gene causes the subtype 1, which represents 65% of the cases. Inactivation of Ca-sensing receptors (CaSR) can also lead to hypercalcemia associated with increased parathyroid hormone (PTH) secretion.[1] It is characterised by causes mild asymptomatic hypercalcemia[2] and hypocalciuria with normal or elevated PTH. FHH is generally asymptomatic and treatment is not needed. Differential diagnosis with primary hyperparathyroidism (PHPT) is crucial and based on calcium-creatinine clearance ratio (CCCR), which, when under 0.02 points to the diagnosis of FHH.[3] Genetic test is necessary for confirmation.[4]

Sign in / Sign up

Export Citation Format

Share Document