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Sample records for 51cr-edta clearance method

  1. Determination of optimal sampling times for a two blood sample clearance method using (51)Cr-EDTA in cats.

    Vandermeulen, Eva; De Sadeleer, Carlos; Piepsz, Amy; Ham, Hamphrey R; Dobbeleir, André A; Vermeire, Simon T; Van Hoek, Ingrid M; Daminet, Sylvie; Slegers, Guido; Peremans, Kathelijne Y

    2010-08-01

    Estimation of the glomerular filtration rate (GFR) is a useful tool in the evaluation of kidney function in feline medicine. GFR can be determined by measuring the rate of tracer disappearance from the blood, and although these measurements are generally performed by multi-sampling techniques, simplified methods are more convenient in clinical practice. The optimal times for a simplified sampling strategy with two blood samples (2BS) for GFR measurement in cats using plasma (51)chromium ethylene diamine tetra-acetic acid ((51)Cr-EDTA) clearance were investigated. After intravenous administration of (51)Cr-EDTA, seven blood samples were obtained in 46 cats (19 euthyroid and 27 hyperthyroid cats, none with previously diagnosed chronic kidney disease (CKD)). The plasma clearance was then calculated from the seven point blood kinetics (7BS) and used for comparison to define the optimal sampling strategy by correlating different pairs of time points to the reference method. Mean GFR estimation for the reference method was 3.7+/-2.5 ml/min/kg (mean+/-standard deviation (SD)). Several pairs of sampling times were highly correlated with this reference method (r(2) > or = 0.980), with the best results when the first sample was taken 30 min after tracer injection and the second sample between 198 and 222 min after injection; or with the first sample at 36 min and the second at 234 or 240 min (r(2) for both combinations=0.984). Because of the similarity of GFR values obtained with the 2BS method in comparison to the values obtained with the 7BS reference method, the simplified method may offer an alternative for GFR estimation. Although a wide range of GFR values was found in the included group of cats, the applicability should be confirmed in cats suspected of renal disease and with confirmed CKD. Furthermore, although no indications of age-related effect were found in this study, a possible influence of age should be included in future studies. PMID:20452793

  2. 51Cr-EDTA plasma clearance in severe renal failure determined by one plasma sample

    Kamper, A L; Nielsen, S L

    1989-01-01

    sample clearance' formulas disregarding exact time of plasma sampling. This method might provide values 3.1 ml/min below or 2.9 ml/min above the established method of total 51Cr-EDTA plasma clearance, and would thus provide insufficient agreement. In the other method an estimate of plasma activity at......Two hundred and thirty-four measurements of standard 51Cr-EDTA plasma clearance were made in 50 patients with severe chronic renal failure. Based on these data two calculation methods were attempted using one plasma sample drawn 24 h after injection of 51Cr-EDTA. One of the methods used the 'one...... zero-time was derived from injected dose and body surface area. This method might provide values 1.5 ml/min below or 0.8 ml/min above the established method of 51Cr-EDTA plasma clearance, which would be acceptable for clinical purposes. It is concluded that exact plasma clearance of 51Cr-EDTA in severe...

  3. Conventional measurements of GFR using 51Cr-EDTA overestimate true renal clearance by 10 percent

    It is widely believed that measurement of the area under the plasma clearance curve (AUC) following a single intravenous injection of chromium-51 labelled ethylene diamine tetra-acetic acid (51Cr-EDTA) is a gold standard method for determining glomerular filtration rate (GFR). However, there are reports that 51Cr-EDTA may have a significant extrarenal clearance. The aim of this study was to identify the non-renal component of 51Cr-EDTA plasma clearance contributing to the AUC measurement of GFR. Seventy healthy postmenopausal women (mean age 60 years, range 45-79 years) were injected with 3 MBq 51Cr-EDTA and 0.25 MBq iodine-125 labelled human serum albumin and 11 blood samples taken between 0 and 4 h through an indwelling venous cannula. For the first 21 subjects, two complete urine collections were made 0-2 h and 2-4 h after injection, and for the final 49 patients, four 1-h urine collections were made. The mean 51Cr-EDTA total plasma clearance was 84 ml/min (range 50-132 ml/min). The mean ratio (SEM) of urine to total clearance determined from the cumulative 1-, 2-, 3- and 4-h data was 0.903 (0.018), 0.891 (0.013), 0.898 (0.011) and 0.899 (0.010) respectively and remained constant despite the mean urine concentration decreasing from 122% to 15%/litre during this period. A least squares fit to data from the 238 individual urine collections was used to determine the fraction of the total plasma clearance attributable to renal clearance, α0, and the residual urine volume, ΔV. The results were α0=0.910 (95% CI: 0.889-0.932) and ΔV=14 ml (95% CI: -4 to +34 ml). The overestimation of the true renal clearance of 51Cr-EDTA by the AUC method is believed to be due to the failure of the plasma clearance curve to reach the true terminal exponential by 2 h after injection as usually assumed. As a result, conventional measurements of GFR using 51Cr-EDTA overestimate the true renal clearance of tracer by approximately 10%. (orig.)

  4. Total plasma clearance versus urinary plasma clearance of (51)Cr-EDTA in patients with cirrhosis with and without fluid retention

    Henriksen, Ulrik Lütken; Hansen, Hanne B; Ring-Larsen, Helmer;

    2015-01-01

    Abstract Background and aim. In patients with fluid retention, the total plasma clearance of (51)Cr-EDTA (ClP) may overestimate the glomerular filtration rate (GFR). The present study was therefore undertaken in order to compare ClP with the urinary plasma clearance of (51)Cr-EDTA (ClU) in patients...... with cirrhosis with and without fluid retention. Material and methods. A total of 136 patients with cirrhosis (24 without fluid retention, 112 with ascites) received a quantitative intravenous injection of (51)Cr-EDTA followed by plasma and quantitative urinary samples for 5 hours. ClP was determined...... from the injected dose relative to the plasma concentration-time area, extrapolated to infinity. ClU was determined as urinary excretion relative to the plasma concentration-time area up to voiding. Results. In patients without fluid retention, the difference between ClP and ClU (ClP - ClU = ClΔ) was...

  5. Comparison of 51Cr-EDTA- with 99mTc-DTPA-slope-clearance for estimation of glomerular filtration rate using the one-compartment model

    Aim of this study is to determine the relationship between 51Cr-EDTA and 99mTc-DTPA slope clearance applying the 'one-compartment model'. Methods: The 'one-compartment model' was chosen to calculate and to compare the glomerular filtration rates of 25 patients with normal and pathological creatinin values after injection of 51Cr-EDTA and 99mTc-DTPA simultaneously. Results: The two clearance values correlated well (r=0.996), and the 99mTc-DTPA clearance was systematically higher (28%). The 99mTc-DTPA was calculated and compared after taking three plasma samples. Taking two samples, only minor differences were seen and the correlation was high (r=0.992). Conclusion: The results of this study encouraged us to adopt the use of 99mTc-DTPA instead of 51Cr-EDTA in determining the glomerular filtration applying the 'one-compartment model' in slope with two plasma samples. (orig.)

  6. Comparative study of conventional PAH and inulin clearance and slope clearance of 131I-o-hippuric acid and 51Cr-EDTA

    ''Classic'' PAH and inulin clearance were determined in 81 patients with renal anomalies or renal diseases of different genesis and severity. In addition, radioisotope nephrography was carried out after administration of I-131-o-hippuric acid, followed by administration of Cr-51-EDTA. The activity decrease was recorded by a sensor located over the patient's right shoulder; the activities of a serum sample and of the urine excreted after 21 or 31 min were measured, and the findings were compared with those of the classic method. The clearance data calculated on the basis of the soulder measurements were hardly compatible with those of the conventional method in the case of 131I-o-hippuric acid (r=0.54) and totally incompatible in the case of 51Cr-EDTA. This means that the method described by Oberhausen is the only accurate method available for a quantitative assessment of the renal function on the basis of measurements of the activity decrease in the body. The activity of urine excreted after 31 min (131I-hippuric acid:r=0.992, 51Cr-EDTA:r=0.79) is a sufficiently accurate parameter although it is inaccurate at PAH clearance, values > 130 ml/min and inulin clearance values > 30 ml/min. Of the many parameters of radioisotope nephrogram curves, in the case of 131I-o-hippuric acid only the parameters related to the ascent between 48 and 120 sec or to the secant ascent yield sufficient quantitative information for certain functional regions (r=0.9 resp. r=0.93). In the case of 51Cr-EDTA, semiquantitative information on the renal function can be obtained by constructing secants on the nephrogram curves (r=0.7 resp. r=0.72). Here as in the case of 131I-hippuric acid, the contribution of each kidney can be determined individually from the functional analysis of both kidneys. (orig.)

  7. What method to use for the renal clearance with {sup 51}Cr-E.D.T.A.: retrospective study among 1157 adults and 286 children; Quelle methode de mesure utiliser pour la clairance renale au 51Cr-EDTA: etude retrospective chez 1157 adultes et 286 enfants

    Lacoeuille, F.; Machefert, N.; Vervueren, L.; Berthelot, C.; Rakotonirina, H.; Le Jeune, J.J.; Couturier, O. [CHU d' Angers, Service de medecine nucleaire, 49 (France); Drablier, G.; Cahouet-Vannier, A. [CHU d' Angers, Service de pharmacie, 49 (France); Denizot, B. [CH Annemasse, service de medecine nucleaire, 74 (France)

    2010-07-01

    Purpose: in the objective to make our practices evolve and to limit the numbers of sampling for patients, we searched to determine if the methods used (4,2 or 1 sampling) to measure the renal clearance to {sup 51}Cr-EDTA give results comparable on the population of patients concerned by this examination. Conclusions: This study allowed to enlighten interchangeability between the four points and two points method for the population studied. It allows to consider a change in our practice for the profit of a two points methods. (N.C.)

  8. Gamma-variate plasma clearance versus urinary plasma clearance of (51) Cr-EDTA in patients with cirrhosis with and without fluid retention

    Fuglsang, Stefan; Henriksen, Ulrik L; Hansen, Hanne B;

    2016-01-01

    In patients with fluid retention, the plasma clearance of (51) Cr-EDTA (Clexp obtained by multiexponential fit) may overestimate the glomerular filtration rate (GFR). The present study was undertaken to compare a gamma-variate plasma clearance (Clgv) with the urinary plasma clearance of (51) Cr......-EDTA (Clu ) in patients with cirrhosis with and without fluid retention. A total of 81 patients with cirrhosis (22 without fluid retention, 59 with ascites) received a quantitative intravenous injection of (51) Cr-EDTA followed by plasma and quantitative urinary samples for 5 h. Clgv was determined from the...... injected dose relative to the plasma concentration-time area, obtained by a gamma-variate iterative fit. Clexp and Clu were determined by standard technique. In patients without fluid retention, Clgv , Clexp and Clu were closely similar. The difference between Clgv and Clu (Clgv - Clu = ΔCl) was mean -0...

  9. Over-estimation of glomerular filtration rate by single injection [51Cr]EDTA plasma clearance determination in patients with ascites

    Henriksen, Jens Henrik Sahl; Brøchner-Mortensen, J; Malchow-Møller, A; Schlichting, P

    1980-01-01

    The total plasma (Clt) and the renal plasma (Clr) clearances of [51Cr]EDTA were determined simultaneously in nine patients with ascites due to liver cirrhosis. Clt (mean 78 ml/min, range 34-115 ml/min) was significantly higher than Clr (mean 52 ml/min, range 13-96 ml/min, P < 0.005). The ascitic...... fluid-plasma activity ratio of [51Cr]EDTA increased throughout the investigation period (5h). The results suggest that [51Cr]EDTA equilibrates slowly with the peritoneal space which indicates that Clt will over-estimate the glomerular filtration rate by approximately 20 ml/min in patients with ascites...

  10. Evaluation of renal function in rats: Renal clearance of 99mTc-DTPA underestimates glomerular filtration rate (GFR) as compared with renal clearance of eH-inulin or 51 CR-EDTA

    The rat is the most commonly used experimental animal and frequently being used to examine the pathophysiology in renal disease. Thus, it is important to apply techniques where renal function is assessed accurately. A special challenge exists in chronic unilateral renal disease for accurate measurement of single kidney GFR (SKGFR). We therefore examined the possibility of developing a method where SK GFR is measured in rats from the plasma clearance of 99mTc-DTPA and the reno graphically determined renal split function. A detailed comparison of renal clearance (Clr) and plasma clearance (Clp) of 99mTc-DTPA with that of 51-Cr-EDTA and 3H-inulin was performed in conscious rats with permanent catheters in the carotic artery, jugular vein and the urinary bladder using the following protocols: 1) Comparison of Clr of 99mTc-DTPA with 3H-inulin using a constant infusion clearance technique with four periods (P1-P4)(n=11), 2) comparison of Clr of 99m Tc-DTPA with that of 51Cr-EDTA or 3H-inulin (n=8) 3) comparison of Clr of 51Cr-EDTA and 3H-inulin using a constant infusion clearance technique with Clp of 99mTc-DTPA using a single injection technique with plasma sampling 4 hours after injection (n=11) and 4) comparison of Clp of 51Cr-EDTA with 99mTc-DTPA using the single injection technique (n=5). The results surprisingly showed that Clr of 99mTc-DTPA consistently was significantly lower than Clr of 51Cr-EDTA (548±146 vs. 860±49 □1/min/100g (avg±std);p<0.01) and of 3H-inulin (548±146 vs. 975±135 □1/min/100g; p<0.01: Interestingly, Clr of 99mTc-DTPA was progressively reduced with time in contrast to a constant Clr of inulin (P1:693±108 vs 939±118; P2:591±94 vs 877±17, P3:594±74 vs 947±131; P4:569±78 vs 991±122). Furthermore, Clp of 99mTc-DTPA was significantly lower than Clp of 51Cr-EDTA (874±130 vs. 1092±43 □1/min/100g;p<(0.01). The average clearance ratio DTPA/EDTA using constant infusion was 0.65±0.15 and 0.80±0.15 after single injection. In

  11. Glomerular filtration rate measured by 51Cr-EDTA clearance: evaluation of captopril-induced changes in hypertensive patients with and without renal artery stenosis

    Anna Alice Rolim Chaves

    2010-01-01

    Full Text Available INTRODUCTION: Renal artery stenosis can lead to renovascular hypertension; however, the detection of stenosis alone does not guarantee the presence of renovascular hypertension. Renovascular hypertension depends on activation of the renin-angiotensin system, which can be detected by functional tests such as captopril renal scintigraphy. A method that allows direct measurement of the baseline and post-captopril glomerular filtration rate using chromium-51 labeled ethylenediamine tetraacetic acid (51Cr-EDTA could add valuable information to the investigation of hypertensive patients with renal artery stenosis. The purposes of this study were to create a protocol to measure the baseline and post-captopril glomerular filtration rate using 51Cr-EDTA, and to verify whether changes in the glomerular filtration rate permit differentiation between hypertensive patients with and without renal artery stenosis. METHODS: This prospective study included 41 consecutive patients with poorly controlled severe hypertension. All patients had undergone a radiological investigation of renal artery stenosis within the month prior to their inclusion. The patients were divided into two groups: patients with (n=21 and without renal artery stenosis, (n=20. In vitro glomerular filtration rate analysis (51Cr-EDTA and 99mTc-DMSA scintigraphy were performed before and after captopril administration in all patients. RESULTS: The mean baseline glomerular filtration rate was 48.6±21.8 ml/kg/1.73 m² in the group wuth renal artery stenosis, which was significantly lower than the GFR of 65.1±28.7 ml/kg/1.73m² in the group without renal artery stenosis (p=0.04. Captopril induced a significant reduction of the glomerular filtration rate in the group with renal artery stenosis (to 32.6±14.8 ml/kg/1.73m², p=0.001 and an insignificant change in the group without RAS (to 62.2±23.6 ml/kg/1.73m², p=0.68. Scintigraphy with technetium-99m dimercapto-succinic acid (DMSA did not show

  12. Glomerular filtration rate measured by {sup 51}Cr-EDTA clearance: evaluation of captopril-induced changes in hypertensive patients with and without renal artery stenosis

    Chaves, Anna Alice Rolim; Buchpiguel, Carlos Alberto; Praxedes, Jose Nery; Bortolotto, Luiz Aparecido; Sapienza, Marcelo Tatit, E-mail: annaalice100@yahoo.com.b [Universidade de Sao Paulo (USP), SP (Brazil). Faculdade de Medicina. Dept. de Neurologia

    2010-07-01

    Introduction: renal artery stenosis can lead to renovascular hypertension; however, the detection of stenosis alone does not guarantee the presence of renovascular hypertension. Renovascular hypertension depends on activation of the renin-angiotensin system, which can be detected by functional tests such as captopril renal scintigraphy. A method that allows direct measurement of the baseline and post-captopril glomerular filtration rate using chromium-51 labeled ethylenediamine tetraacetic acid ({sup 51}Cr-EDTA) could add valuable information to the investigation of hypertensive patients with renal artery stenosis. The purposes of this study were to create a protocol to measure the baseline and post-captopril glomerular filtration rate using {sup 51}Cr-EDTA, and to verify whether changes in the glomerular filtration rate permit differentiation between hypertensive patients with and without renal artery stenosis. Methods: this prospective study included 41 consecutive patients with poorly controlled severe hypertension. All patients had undergone a radiological investigation of renal artery stenosis within the month prior to their inclusion. The patients were divided into two groups: patients with (n=21) and without renal artery stenosis, (n=20). In vitro glomerular filtration rate analysis ({sup 51}Cr-EDTA) and {sup 99m}Tc-DMSA scintigraphy were performed before and after captopril administration in all patients. Results: the mean baseline glomerular filtration rate was 48.6+-21.8 ml/kg/1.73 m{sup 2} in the group with renal artery stenosis, which was significantly lower than the GFR of 65.1+-28.7 ml/kg/1.73m{sup 2} in the group without renal artery stenosis (p=0.04). Captopril induced a significant reduction of the glomerular filtration rate in the group with renal artery stenosis (to 32.6+-14.8 ml/kg/1.73m{sup 2}, p=0.001) and an insignificant change in the group without RAS (to 62.2+-23.6 ml/kg/1.73m{sup 2}, p=0.68). Scintigraphy with technetium-99m dimercapto

  13. Validation of calculated eGFR compared with 51Cr-EDTA clearance on a patient population from northern Jutland in Denmark

    Nielsen, Nikolaj Schandorph

    I mange år har man anvendt patienters plasma-creatinin niveau i blodet som et estimat for nyrefunktionen. I september 2010 blev der i Aalborg indført eGFR som etstimat på nyrefunktion ud fra plasma-creatinin. Det er kendt at GFR bestemt ved 51Cr-EDTA clearence er det bedste bud på patienters...... nyrefunktion, og derfor undersøges validiteten af eGFR i forhold til GFR bestemt ved 51Cr-EDTA clearence....

  14. Effect of background region of interest and time-interval selection on glomerular filtration ratio estimation by percentage dose uptake of (99m)Tc-DTPA in comparison with (51)Cr-EDTA clearance in healthy cats.

    Debruyn, Katrien; Vandermeulen, Eva; Saunders, Jimmy H; Dobbeleir, André A; Ham, Hamphrey R; Peremans, Kathelijne

    2013-08-01

    Evaluation of glomerular function is a useful part of the diagnostic approach in animals suspected of having renal disease. Time-interval and background region of interest (bg ROI) selection are determining factors when calculating the glomerular filtration ratio (GFR) based on percentage uptake of (99m)technetium-labelled diethylene triamine penta-acetic acid ((99m)Tc-DTPA). Therefore, three different time intervals (60-120 s, 120-180 s, 60-180 s) and three different bg ROIs (C-shape, caudolateral, cranial + caudal) were investigated. In addition, global GFRs based on percentage dose uptake of (99m)Tc-DTPA for the different time-intervals and bg ROIs were compared with the global GFR based on (51)chromium-ethylene diaminic tetra-acetic acid ((51)Cr-EDTA) plasma clearance in nine healthy European domestic shorthair cats. Paired Student's t-tests and linear regression analysis were used to analyse the data. Different time intervals seemed to cause significant variation (P <0.01) in absolute GFR values, regardless of the choice of bg ROI. Significant differences (P <0.01) between bg ROIs were only observed in the 120-180s time interval between the C-shape and cranial + caudal bg ROI, and between the caudolateral and cranial + caudal bg ROI. The caudolateral bg ROI in the 60-180 s time interval showed the highest correlation coefficient (r = 0.882) between (99m)Tc-DTPA and (51)Cr-EDTA, although a significant difference (P <0.05) was present between both techniques. PMID:23349527

  15. 51Cr-EDTA: a marker of early intestinal rejection in the rat

    Intestinal permeability was studied after accessory intestinal transplantation in Lewis rats. Five groups were evaluated: Group 1--isografts (N = 6); Group 2--Lewis X Brown Norway F1 (LBN-F1) allografts (N = 6); Group 3--isografts treated with CsA 2 mg/kg/day X 10 days (N = 6); Group 4--LBN-F1 allografts treated with CsA 2 mg/kg/day X 10 days (N = 6); Group 5--LBN-F1 allografts treated with CsA 4 mg/kg/day X 28 days (N = 6). Chromium-labeled ethylenedimianetetraacetate (51Cr-EDTA) was given through the proximal stoma of the graft. Renal clearance of 51Cr-EDTA and mucosal biopsies were followed post-transplant. The biopsies of the intestinal graft showed no rejection in Groups 1, 3, and 5; fulminant rejection in Group 2; and mild atypical rejection in Group 4. 51Cr-EDTA clearance was elevated in all groups during the first 7 days post-transplant. Thereafter, 51Cr-EDTA excretion fell to lower levels in the animals with histologically normal grafts (Groups 1, 3, and 5). 51Cr-EDTA excretion in Group 4 was increased with the first histological evidence of rejection on Day 14 and remained elevated until sacrifice (P less than 0.02 compared to Groups 3 and 5). A transient permeability defect occurs after intestinal grafting. Once the graft has recovered from this injury, 51Cr-EDTA is a sensitive marker for intestinal rejection

  16. Estimating GFR in children with 99mTc-DTPA renography: a comparison with single-sample 51Cr-EDTA clearance

    Gutte, Henrik; Møller, Michael L; Pfeifer, Andreas K; Thorup, Jørgen Mogens; Borgwardt, Line; Borgwardt, Lise; Kristoffersen, Ulrik S; Kjaer, Andreas

    2010-01-01

    Glomerular filtration rate (GFR) measurement by (51)Cr-ethylenediaminetetraacetic acid (EDTA) and blood sampling in children is usually cumbersome for the patient, parents and laboratory technicians. We have previously developed a method accurately estimating GFR in adults. The aim of the present...

  17. Intestinal permeability assessed by 51Cr-EDTA in rats with CCl4 - induced cirrhosis Permeabilidade intestinal ao 51-Cr-EDTA em ratos com cirrose induzida por CCl4

    Ana Regina L. Ramos

    2010-06-01

    Full Text Available CONTEXT: The straight relationship between cirrhosis and impaired intestinal barrier has not been elucidated yet. OBJECTIVES: To verify 51Cr-EDTA-intestinal permeability in rats with CCl4-induced cirrhosis and controls. METHOD: Fifty male Wistar rats weighing 150-180 g were separated in three groups: 25 animals received CCl4 0.25 mL/kg with olive oil by gavage with 12 g/rat/day food restriction for 10 weeks (CCl4-induced cirrhosis; 12 received the same food restriction for 10 weeks (CCl4-non exposed. Other 13 rats received indomethacin 15 mg/kg by gavage as positive control of intestinal inflammation. RESULTS: The median (25-75 interquartile range 51Cr-EDTA-IP values of cirrhotic and CCl4-non exposed rats were 0.90% (0.63-1.79 and 0.90% (0.60-1.52 respectively, without significant difference (P = 0.65. Animals from indomethacin group showed 51Cr-EDTA-IP, median 7.3% (5.1-14.7, significantly higher than cirrhotic and CCl4-non exposed rats (PCONTEXTO: A relação direta entre cirrose e alterações na barreira intestinal ainda não foi devidamente esclarecida. OBJETIVO: Verificar a permeabilidade intestinal ao 51Cr-EDTA em ratos com cirrose induzida por tetracloreto de carbono (CCl4 e controles. MÉTODO: Cinquenta ratos Wistar machos pesando 150-180 g foram separados em três grupos: 25 animais receberam CCl4 0,25 mL/kg diluído em óleo de oliva por gavagem com restrição dietética de 12 g/rato/dia por 10 semanas (grupo cirrose induzida por CCl4; 12 receberam a mesma restrição dietética por 10 semanas (grupo não exposto ao CCl4. Outros 13 ratos receberam indometacina 15 mg/kg por gavagem como controle positivo de inflamação intestinal. RESULTADOS: A mediana (intervalo interquartil 25-75 dos valores de permeabilidade intestinal ao 51Cr-EDTA dos grupos cirrose induzida por CCl4 e não exposto ao CCl4 foram 0,90% (0,63-1,79 e 0,90% (0,60-1,52, respectivamente, sem significância estatística (P = 0,65. Os animais do grupo indometacina

  18. (51Cr)EDTA intestinal permeability in children with cow's milk intolerance

    Schrander, J.J.; Unsalan-Hooyen, R.W.; Forget, P.P.; Jansen, J. (Academic Hospital Maastricht (Netherlands))

    1990-02-01

    Making use of ({sup 51}Cr)EDTA as a permeability marker, we measured intestinal permeability in a group of 20 children with proven cow's milk intolerance (CMI), a group of 17 children with similar complaints where CMI was excluded (sick controls), and a group of 12 control children. ({sup 51}Cr)EDTA test results (mean +/- SD) were 6.85 +/- 3.64%, 3.42 +/- 0.94%, and 2.61 +/- 0.67% in the group with CMI, the sick control, and the control group, respectively. When compared to both control groups, patients with cow's milk intolerance (CMI) showed a significantly increased small bowel permeability. We conclude that the ({sup 51}Cr)EDTA test can be helpful for the diagnosis of cow's milk intolerance.

  19. [51Cr]EDTA intestinal permeability in children with cow's milk intolerance

    Making use of [51Cr]EDTA as a permeability marker, we measured intestinal permeability in a group of 20 children with proven cow's milk intolerance (CMI), a group of 17 children with similar complaints where CMI was excluded (sick controls), and a group of 12 control children. [51Cr]EDTA test results (mean +/- SD) were 6.85 +/- 3.64%, 3.42 +/- 0.94%, and 2.61 +/- 0.67% in the group with CMI, the sick control, and the control group, respectively. When compared to both control groups, patients with cow's milk intolerance (CMI) showed a significantly increased small bowel permeability. We conclude that the [51Cr]EDTA test can be helpful for the diagnosis of cow's milk intolerance

  20. Intestinal permeability to [51Cr]EDTA in children with cystic fibrosis

    Intestinal permeability was investigated in 14 children with cystic fibrosis making use of [51Cr]EDTA as probe molecule. Ten normal young adults and 11 children served as controls. After oral administration of [51Cr]EDTA, 24 h urine was collected. Urinary radioactivity was calculated and results expressed as percentage of oral dose excreted in 24 h urine. Mean and SEM were as follows: 2.51 +/- 0.21, 2.35 +/- 0.24, and 13.19 +/- 1.72 for control children, normal adults, and cystic fibrosis patients, respectively. The permeability differences between cystic fibrosis patients and either control children or control adults are significant (p less than 0.001)

  1. Reversibility of increased intestinal permeability to 51Cr-EDTA in patients with gastrointestinal inflammatory diseases

    Intestinal permeability in adults with inflammatory gastrointestinal diseases was investigated by measuring the 24-h urinary excretion of orally administered 51Cr-EDTA. Eighty controls along with 100 patients with Crohn's disease, 46 patients with ulcerative colitis, 20 patients with gluten-sensitive enteropathy, and 18 patients with other diseases were studied. In controls, the median 24-h excretion was 1.34%/24 h of the oral dose. Patients with Crohn's disease (median 2.96%/24 h), ulcerative colitis (median 2.12%/24 h), and untreated gluten-sensitive enteropathy (median 3.56%/24 h) had significantly elevated urinary excretion of the probe compared to controls (p less than 0.0001). Increased 24-h urinary excretion of 51Cr-EDTA had a high association with intestinal inflammation (p less than 0.0001). Test specificity and sensitivity were 96% and 57%, respectively. A positive test has a 96% probability of correctly diagnosing the presence of intestinal inflammation, whereas a negative test has a 50% probability of predicting the absence of disease

  2. Intestinal permeability to (/sup 51/Cr)EDTA in children with Crohn's disease and celiac disease

    Turck, D.; Ythier, H.; Maquet, E.; Deveaux, M.; Marchandise, X.; Farriaux, J.P.; Fontaine, G.

    1987-07-01

    (/sup 51/Cr)EDTA was used as a probe molecule to assess intestinal permeability in 7 healthy control adults, 11 control children, 17 children with Crohn's disease, and 6 children with untreated celiac disease. After subjects fasted overnight, 75 kBq/kg (= 2 microCi/kg) /sup 51/Cr-labeled EDTA was given by mouth; 24-h urinary excretion of (/sup 51/Cr)EDTA was measured and expressed as a percentage of the total oral dose. Mean and SD were as follows: control adults 1.47 +/- 0.62, control children 1.59 +/- 0.55, and patients with Crohn's disease or celiac disease 5.35 +/- 1.94. The difference between control children and patients was statistically significant (p less than 0.001). These results show that intestinal permeability to (/sup 51/Cr)EDTA is increased among children with active or inactive Crohn's disease affecting small bowel only or small bowel and colon, and with untreated celiac disease. The (/sup 51/Cr)EDTA permeability test could facilitate the decision to perform more extensive investigations in children suspected of small bowel disease who have atypical or poor clinical and biological symptomatology.

  3. Arterio-venous concentration difference of [51Cr]EDTA after a single injection in man. Significance of renal function and local blood flow

    Rehling, M; Hyldstrup, L; Henriksen, Jens Henrik Sahl

    1989-01-01

    The present investigation was undertaken in order to study (1) the difference in arterial (Ca) and venous (Cv) concentration of [51Cr]EDTA (ethylenediaminetetraacetate) after a single intravenous injection, (2) the impact of different physiological variables on this difference, and (3) the error...

  4. Reassessment of a classical single injection 51Cr-EDTA clearance method for determination of renal function in children and adults. Part I: Analytically correct relationship between total and one-pool clearance

    Jødal, Lars; Brøchner-Mortensen, Jens

    2009-01-01

    and adults. Material and methods. Cl was determined in 149 subjects (M/F/children: 71/46/32) from a complete plasma concentration curve followed for 4-5 h after injection of 51Cr-EDTA (range of clearance: 8-183 mL/min/1.73 m²). Plasma volume, PV and the "missing" area under the plasma fraction curve......Background. Total plasma clearance of 51Cr-EDTA, Cl, is widely used as a measure of GFR. Commonly, only the final part of the plasma concentration curve is measured, and a one-pool clearance (slope-intercept clearance), Cl1, is computed. Empirically determined second-order polynomials of the......, a (minutes), not used for determination of Cl1, were measured. Results. The true relationship between Cl and Cl1 is given by Cl = Cl1/(1+f·Cl1), where f = a/PV. For men, women and children alike, the equation f = 0.0032·BSA-1.3 was applicable (BSA = body surface area in m²). Estimation errors on...

  5. Excretion of radionuclides in human breast milk following administration of 125I-fibrinogen, 99Tc/sup m/-MAA and 51Cr-EDTA

    Very few biokinetic and dosimetric data for estimating the absorbed dose to a breast-feeding child are available in the literature. The few available are usually case reports. We have measured the activity concentration in breast milk from one patient after administration of 125I-fibrinogen, from two patients after administration of 99Tc/sup m/-macroaggregated albumin, and from one patient after administration of 51Cr-EDTA. We have compared our data with earlier published results and estimated the absorbed dose to the breast-feeding child using biokinetic data presented in this work and recently published S-values for new-born children

  6. Mean retention time of 51Cr-EDTA and 103Ru-phenanthroline in the digestive tract of sheep and bulls after feeding on straw pellets

    Two lots of straw pellets (supplemented with 10% molasses), produced either with a 5 mm sieve in a hammer mill (lot A) or with a 12 mm sieve (lot B) from wheat straw, were tested with 4 sheep (wethers, average live weight 43 kg) and 4 bulls (average live weight 170 kg). After carrying out a digestibility experiment, the mean retention time, the 80% excretion of the markers and the transit time were ascertained with the help of 51Cr-EDTA and 103Ru-phenanthroline. The digestibility of carbohydrates (both crude fiber and N-free extractives) was significantly higher for the bulls than for the sheep. (author)

  7. Rapid decline in 51Cr-EDTA measured renal function during the first weeks following lung transplantation

    Hornum, M.; Iversen, M.; Steffensen, I.;

    2009-01-01

    We previously described a 54% decline in renal function at 6 months after lung transplantation (LTx). We hypothesized that this decline is a very early event following LTx. Thirty-one consecutive patients (16 females/15 males), mean age 49 (+/-13) years, with emphysema, cystic fibrosis....../bronchiectasis or idiopathic pulmonary fibrosis were included in an analysis of renal function before and after LTx. The glomerular filtration rate (GFR) was measured using the (51)Cr-ethylenediaminetetra acetic acid plasma clearance single injection technique (mGFR) at baseline before transplantation and at 1, 2.......0001), acute renal failure within 2 weeks post-LTx (p = 0.0003), use of heart and lung machine (p = 0.04), and the use of ephedrine (p = 0.048), as well as increasing age, older than 18 years at LTx (p = 0.006). These data demonstrate that renal function, measured with an isotope method, decreases dramatically...

  8. Rapid decline in 51Cr-EDTA measured renal function during the first weeks following lung transplantation

    Hornum, Mads; Iversen, Martin; Steffensen, Ida; Hovind, Peter; Carlsen, Jørn; Andersen, Lars Willy; Steinbrüchel, Daniel Andreas; Feldt-Rasmussen, Bo Friis

    2009-01-01

    /bronchiectasis or idiopathic pulmonary fibrosis were included in an analysis of renal function before and after LTx. The glomerular filtration rate (GFR) was measured using the (51)Cr-ethylenediaminetetra acetic acid plasma clearance single injection technique (mGFR) at baseline before transplantation and at 1, 2......We previously described a 54% decline in renal function at 6 months after lung transplantation (LTx). We hypothesized that this decline is a very early event following LTx. Thirty-one consecutive patients (16 females/15 males), mean age 49 (+/-13) years, with emphysema, cystic fibrosis...

  9. Arterio-venous concentration difference of [51Cr]EDTA after a single injection in man. Significance of renal function and local blood flow

    Rehling, M; Hyldstrup, Lars; Henriksen, Jens Henrik

    1989-01-01

    The present investigation was undertaken in order to study (1) the difference in arterial (Ca) and venous (Cv) concentration of [51Cr]EDTA (ethylenediaminetetraacetate) after a single intravenous injection, (2) the impact of different physiological variables on this difference, and (3) the error...... 180-300 min post-injection (p.i.) Cv was 5.9% higher than Ca (range 0.5-13.9%, P less than 0.001). The more reduced renal function, the smaller was the concentration difference. The areas under the arterial and the venous plasma concentration curves did not differ significantly at either 0-infinity or...... 0-300 min p.i. whereas the venous area 0-100 min p.i. underestimated the arterial area in the same period by 4.1% (P less than 0.05). In a computer simulation model, variation in the forearm capillary permeability-surface area product did not have any significant influence on the Cv-Ca difference...

  10. Kidney function measured by clearance. Methods and indications. An update; Zur Messung der Nierenfunktion durch Clearancebestimmungen. Methoden und Indikationen. Ein Update

    Durand, E. [Universitaetskrankenhaus Bicetre, Paris (France); Mueller-Suur, R. [Karolinska Inst., Danderyds Krankenhaus und Aleris Fysiologlab, Stockholm (Sweden)

    2010-09-15

    Renal function impairment can be monitored by many tests. Measurement of plasma-creatinine level is the most used method, 24 h plasma-creatininclearance with urine collection is used by others and also other alternative but indirect methods exist. However, the use of radionuclide-clearances is by far the easiest performed method with the highest accuracy and precision and gives very low irradiation dose. In the following we will discuss the different radiopharmaceuticals in use, their plus and minus, the different clearance methods in use, their limitations and give some clinically important indications to perform clearance investigations according to consensus reports. Summarizing the use of plasma clearance of 51-Cr-EDTA after a single injection with one blood sample can be generally recommended, however with some modifications in special clinical situations, which are pointed out. Please note, that this paper is, for a significant part, an update of a previous paper published 2003 in ''Der Nuklearmediziner'' (orig.)

  11. Simplified methods for assessment of renal function as the ratio of glomerular filtration rate to extracellular fluid volume

    Jødal, Lars; Brøchner-Mortensen, Jens

    2012-01-01

    contact with the ‘regulator’ (i.e. the kidneys). Aim: The aim of the present study was as follows: to analyse two published calculation methods for determining ECV and GFR/ECV; to develop a new simple and accurate formula for determining ECV; and to compare and evaluate these methods. Materials and...... methods: GFR was determined as 51Cr-EDTA clearance. The study comprised 128 individuals (35 women, 66 men and 27 children) with a full 51Cr-EDTA plasma concentration curve, determined from injection until 4–5 h p.i. Reference values for GFR and ECV were calculated from the full curve. One......-pool approximations Cl1 and V1 were calculated using only the final-slope curve. Four calculation methods were compared: simple one-pool values; GFR/ECV according to Peters and colleagues; ECV according to Brøchner-Mortensen (BM); and ECV according to a new method (JBM): y=2x – 1, where x = Cl1/Cl and y = V1/ECV...

  12. Method of mucociliary clearance assessment

    Danilova, Tatiana V.; Manturov, Alexey O.; Ermakov, Igor Y.; Mareev, Gleb O.; Mareev, Oleg V.

    2016-04-01

    The article is devoted to the research capabilities of mucociliary clearance in the nasal cavity and paranasal sinuses using modern techniques of digital video recording and processing. We describe the setup and software for this method and the results of our research. Using microscope and digital camera we can provide a good method to study mucociliary clearance and by usage of special software we able to measure some characteristic of nasal mucosae and its main function.

  13. Revisiting normal {sup 51}Cr-ethylenediaminetetraacetic acid clearance values in children

    Piepsz, A.; Tondeur, M. [Department of Radioisotopes, CHU St Pierre, Brussels (Belgium); Ham, H. [Department of Nuclear Medicine, UZ Ghent, Ghent (Belgium)

    2006-12-15

    Normal {sup 51}Cr-ethylenediaminetetraacetic acid (EDTA) clearance values as a function of age were published a number of years ago. These values were based on data from children with a normal left to right ratio and a normal appearance on DMSA scintigraphy, despite the presence of an acute renal infection. At that time, the authors were unaware that hyperfiltration is a common phenomenon in patients with acute renal infection and that their normal values could have been significantly overestimated. The present work therefore aimed to re-appraise these normal values. In a first step, in order to verify the previous results, the same type of population was selected, namely patients with present or past urinary tract infection but normal images and a normal left to right ratio on DMSA scintigraphy. In a second step, the selection was based on patients who had had no recent urinary tract infection. In both series, a single blood sample method was used for the evaluation of {sup 51}Cr-EDTA clearance. In the first group of patients, the results obtained were almost identical to those previously published. In the second group of patients, the results were significantly lower: after 2 years of age, the mean GFR value was 104 ml/min/1.73 m{sup 2} (10th and 90th percentiles 81 and 135 ml/min/1.73 m{sup 2}, respectively), compared with 117 ml/min/1.73 m{sup 2} in the first group. The data of the second group are probably more representative of the true normal GFR values and can be applied to the entire paediatric population. (orig.)

  14. The clearance concept with special reference to determination of glomerular filtration rate in patients with fluid retention

    Henriksen, Ulrik L; Henriksen, Jens H

    2014-01-01

    be assessed to obtain a correct measurement of the glomerular filtration rate (GFR). In theory, total plasma clearance with late samples (24-h, 48-h) may be applied in patients with fluid retention, but validation hereof has not been performed. Until such studies are completed, it is recommended that......In subjects without fluid retention, the total plasma clearance of a renal filtration indicator (inulin, (99m) Tc-DTPA, (51) Cr-EDTA) is close to the urinary plasma clearance. Conversely, in patients with fluid retention (oedema, pleural effusions, ascites), there is a substantial discrepancy...... patients with fluid retention have their GFR measured by a urinary plasma clearance technique with controlled quantitativeurinary sampling within a few hours after indicator injection....

  15. Måling af nyrefunktion under cytostatisk behandling

    Hartlev, Louise Brøndt; Bøje, Charlotte Rotbøl; Bluhme, Henrik;

    2008-01-01

    INTRODUCTION: Some cytostatics, used in the treatment of cancer, are excreted by the kidneys and may be nephrotoxic. The glomerular filtration rate (GFR) represents a method for reliable assessement of the 51Cr-EDTA plasma clearance before and during treatment with nephrotoxic drugs. The aim of...

  16. Clearance detector and method for motion and distance

    Xavier, Patrick G. (Albuquerque, NM)

    2011-08-09

    A method for correct and efficient detection of clearances between three-dimensional bodies in computer-based simulations, where one or both of the volumes is subject to translation and/or rotations. The method conservatively determines of the size of such clearances and whether there is a collision between the bodies. Given two bodies, each of which is undergoing separate motions, the method utilizes bounding-volume hierarchy representations for the two bodies and, mappings and inverse mappings for the motions of the two bodies. The method uses the representations, mappings and direction vectors to determine the directionally furthest locations of points on the convex hulls of the volumes virtually swept by the bodies and hence the clearance between the bodies, without having to calculate the convex hulls of the bodies. The method includes clearance detection for bodies comprising convex geometrical primitives and more specific techniques for bodies comprising convex polyhedra.

  17. Aspects of osseous, peritoneal and renal handling of bisphosphonate during peritoneal dialysis: a methodological study

    Joffe, P; Henriksen, Jens Henrik Sahl

    1996-01-01

    -acetic acid (51Cr-EDTA). Eight patients on CAPD were studied cross-sectionally. The mean plasma clearances of 99mTc-MBP and 51Cr-EDTA in the steady state (4h) were 38.2 and 12.2 ml min-1 (p < 0.01), the peritoneal clearances (0-4 h) were 5.2 and 7.2 ml min-1 (p < 0.01), and the renal clearances (0-4 h) were 2......Tc-MBP equal the clearances of 51Cr-EDTA is correct from a clinical point of view. We found that the uptake of the tracers in soft tissue and the renal handling of 51Cr-EDTA and 99mTc-MBP are also similar. The differences between the clearance values for 51Cr-EDTA and 99mTc-MBP may be explained by their...

  18. Stability, protein binding and clearance studies of [99mTc]DTPA. Evaluation of a commercially available dry-kit

    Rehling, M

    1988-01-01

    quality of a commercial [99mTc]DTPA preparation (C.I.S., France) with reference to stability, protein binding and accuracy of the determined plasma clearance values as a measure of GFR. The stability of the preparations was studied by thin-layer chromatography, the in vitro protein binding by Sephadex...... filtration after incubation with human serum albumin and in vivo protein binding by filtration of human plasma. The accuracy of the plasma clearance values was investigated by comparison with the simultaneously measured plasma clearance of [51Cr]EDTA. There was no detectable free pertechnetate or hydrolysed...... reduced technetium in eight vials five and six hours after the preparation. The in vitro protein binding 10 (20), 120 and 300 min after the preparation of eight vials was 2.3% (0.8%), 0.2% and 0.1%, respectively. The in vivo protein binding in 12 patients 5, 90 and 180 min after the injection was 0.3%, 0...

  19. Reliability of a 99sp(m)Tc-DTPA gamma camera technique for determination of single kidney glomerular filtration rate

    In a recent paper we described a method for calculation of single kidney glomerular filtration rate (SKGFR) from the 99sp(m)Tc-DTPA renogram obtained by gamma camera. In this paper the reliability of the method was compared to other methods for estimation of GFR in 20 unilaterally nephrectomized patients. The values for SKGFR obtained from the renograms and from the estimated endogenous creatinine clearances according to serum creatinine concentration and a nomogram were both accurate. The reliability of the renography method was significantly better judged by less variance in the estimates. SKGFR calculated from the plasma clearance of 51Cr-EDTA overestimated the renal clearance of inulin on an average by 11.3%. No difference was found in the variance of the values obtained from the renograms and from the plasma clearances of 51Cr-EDTA compared to the renal clearance of inulin. Apart from the inaccuracy in the GFR values calculated from the plasma clearance of 51Cr-EDTA, the reliability of these two methods was equal. (author)

  20. Influence of renal function on the elimination of morphine and morphine glucuronides

    Wolff, Jesper; Bigler, Dennis Richard; Christensen, C B; Rasmussen, S N; Andersen, H B; Tønnesen, K H

    1988-01-01

    The influence of renal function, measured by 51Cr-EDTA clearance, on morphine and morphine glucuronide kinetics has been studied in 13 patients after a single i.v. injection of morphine. Unconjugated morphine and morphine glucuronides were measured by a sensitive, specific RIA after extraction from...... plasma. No significant correlation was found between total body clearance of unconjugated morphine and 51Cr-EDTA clearance. However, patients with renal insufficiency had impaired elimination of morphine glucuronides, and the apparent clearance was significantly correlated with the 51Cr-EDTA clearance (r...

  1. A simple method for the verification of clearance levels for non-radioactive solid waste

    ANSTO's radiopharmaceutical production laboratories generate 25 m3 of solid waste per month. Most of this waste is not radioactive. Up until recently the non-radioactive waste was cleared from the controlled area and stored for 10 halflives prior to disposal as normal solid refuse. To eliminate the storage and ''double handling'' of the large quantities of non-radioactive waste a simple clearance method was devised to allow direct disposal. This paper describes how clearance levels were determined. Here the term ''clearance level'' is used as a general term for the release of material regardless of whether it was previously subject to regulatory control. This contrasts with the IAEA definition of a clearance level and highlights a potential problem with the implementation of exemption levels to keep material out of regulatory control and the use of clearance levels to allow removal of materials from regulatory control. Several common hand held contamination monitors were tested to determine their limits of detection and ability to meet these clearance levels. The clearance method includes waste segregation and size limitation features to ensure the waste is monitored in a consistent manner, compatible with the limits of detection. The clearance levels achieved were subsequently found to be compatible with some of the unconditional clearance levels in IAEA-TECDOC-855 and the measurement method also meets the required features of that document. The ANSTO non-radioactive waste clearance system has been in operation for more than 12 months and has proved simple and effective to operate. Approximately 12m3 of the solid waste is now been treated directly as normal solid refuse. This paper describes the ANSTO clearance system, the contamination monitor tests and details practical problems associated with the direct monitoring of solid waste, including averaging of the activity in the package. The paper also briefly highlights the potential problem with the use of exempted

  2. Evaluation of total renal function from 99mTc-MAG3 scintigraphy in children

    Aim: The aim of the present study was to evaluate the usefulness of dynamic scintigraphy in the assessment of total renal function in children. The Patlak slope of 99mTc-MAG3 renography curves were compared to the plasma clearance values of 51Cr-EDTA. Material and methods: The study sample consisted of 53 boys and 33 girls with various nephrologic disorders, referred for routine clinical reasons. The median age of the subjects was 5.1 years (range 0.3 - 14.1 years). Imaging procedure. In supine position, the patient received a bolus injection of 1 MBq/kg, (minimum 10 MBq) 99mTc-MAG3 and a posterior dynamic gamma camera registration was performed for 21 min using 1 frame per second during the first minute and thereafter 10 seconds frames. Data analysis. Time-activity curves were generated from manually drawn heart and renal regions of interest. The MAG3 uptake was calculated from the Patlak-Rutland plot of each kidney by linear curve fitting until the beginning of the excretory phase. A sum of the slope values was used as a measure of total renal MAG3 uptake. Cr-EDTA clearance. Glomerular filtration rate (GFR) was measured from the plasma clearance of 51Cr-EDTA using single injection, multiple-sample technique. After intravenous injection of 51Cr-EDTA (74 kBq/kg for children up to 7 years, 37 kBq/kg for children older than 7 years), blood samples were drawn at 5, 10, 15, 45, 60, 120 and 180 min for radioactivity measurement. The GFR was calculated according to Broechner-Mortensen and expressed in ml/min. Results: The absolute 51Cr-EDTA clearance varied from 9 to 143 ml/min. There was a close linear relationship between 51Cr-EDTA clearance and MAG3 uptake (Fig). The correlation coefficient was 0.90 and the regression equation (y=43.5 x + 664). Conclusions: In the present study, there was a good correlation between plasma clearance of 51Cr-EDTA and the sum of the Patlak slopes. The regression equation can be utilised to transform the 99mTc-MAG3 uptake to an estimate

  3. Glomerular filtration rate estimated from the uptake phase of 99mTc-DTPA renography in chronic renal failure

    Petersen, L J; Petersen, J R; Talleruphuus, U;

    1999-01-01

    The purpose of the study was to compare the estimation of glomerular filtration rate (GFR) from 99mTc-DTPA renography with that estimated from the renal clearance of 51Cr-EDTA, creatinine and urea.......The purpose of the study was to compare the estimation of glomerular filtration rate (GFR) from 99mTc-DTPA renography with that estimated from the renal clearance of 51Cr-EDTA, creatinine and urea....

  4. A computer program for unilateral renal clearance calculation by a modified Oberhausen method

    A FORTAN program is presented which, on the basis of data obtained with NUKLEOPAN M, calculates the glomerular filtration rate with sup(99m)Tc-DTPA, the unilateral effective renal plasma flow with 131I-hippuran, and the parameters for describing the isotope rephrogram (ING) with 131I-hippuran. The results are calculated fully automatically upon entry of the data, and the results are processed and printed out. The theoretical fundamentals of ING and whole-body clearance calculation are presented as well as the methods available for unilateral clearance calculation, and the FORTAN program is described in detail. The standard values of the method are documented, as well as a comparative gamma camera study of 48 patients in order to determine the accuracy of unilateral imaging with the NUKLEOPAN M instrument, a comparison of unilateral clearances by the Oberhausen and Taplin methods, and a comparison between 7/17' plasma clearance and whole-body clearance. Problems and findings of the method are discussed. (orig./MG)

  5. A camera based calculation of 99m Tc-MAG-3 clearance using conjugate views method

    Background: measurement of absolute or different renal function using radiotracers plays an important role in the clinical management of various renal diseases. Gamma camera quantitative methods is approximations of renal clearance may potentially be as accurate as plasma clearance methods. However some critical factors such as kidney depth and background counts are still troublesome in the use of this technique. In this study the conjugate-view method along with some background correction technique have been used for the measurement of renal activity in99mTc- MAG3 renography. Transmission data were used for attenuation correction and the source volume was considered for accurate background subtraction. Materials and methods: the study was performed in 35 adult patients referred to our department for conventional renography and ERPF calculation. Depending on patients weight approximately 10-15 mCi 99 Tc-MAG3 was injected in the form of a sharp bolus and 60 frames of 1 second followed by 174 frames of 10 seconds were acquired for each patient. Imaging was performed on a dual-head gamma camera(SOLUS; SunSpark10, ADAC Laboratories, Milpitas, CA) anterior and posterior views were acquired simultaneously. A LEHR collimator was used to correct the scatter for the emission and transmission images. Buijs factor was applied on background counts before background correction (Rutland-Patlak equation). gamma camera clearance was calculated using renal uptake in 1-2, 1.5-2.5, 2-3 min. The same procedure was repeated for both renograms obtained from posterior projection and conjugated views. The plasma clearance was also directly calculated by three blood samples obtained at 40, 80, 120 min after injection. Results: 99 Tc-MAG3 clearance using direct sampling method were used as reference values and compared to the results obtained from the renograms. The maximum correlation was found between conjugate view clearance at 2-3 min (R=0.99, R2=0.98, SE=15). Conventional posterior

  6. Body counter

    The paper gives a survey on some applications of the whole body counter in clinical practice and a critical study of its application as a routine testing method. Remarks on the necessary precautions are followed by a more detailed discussion of the determination of the natural potassium content, the iron metabolism, the vitamin B12 test, investigations of the metabolism of the bone using 47Ca and 85Sr, investigations with iodine and iodine-labelled substances, clearance investigations (in particular the 51Cr EDTA clearance test), as well as the possibilities of neutron activation in vivo. (ORU/AK)

  7. Measuring method for clearance of slightly contaminated scrap-metal

    The method is based on the measurement of dose rates by means of thermoluminescent dosemeters. It can be used for activity levels down to 400 Bq per kg and it has a measuring error of +-40%. The necessary recording time is approx. one week. (G.B.)

  8. A parameters optimization method for planar joint clearance model and its application for dynamics simulation of reciprocating compressor

    Hai-yang, Zhao; Min-qiang, Xu; Jin-dong, Wang; Yong-bo, Li

    2015-05-01

    In order to improve the accuracy of dynamics response simulation for mechanism with joint clearance, a parameter optimization method for planar joint clearance contact force model was presented in this paper, and the optimized parameters were applied to the dynamics response simulation for mechanism with oversized joint clearance fault. By studying the effect of increased clearance on the parameters of joint clearance contact force model, the relation of model parameters between different clearances was concluded. Then the dynamic equation of a two-stage reciprocating compressor with four joint clearances was developed using Lagrange method, and a multi-body dynamic model built in ADAMS software was used to solve this equation. To obtain a simulated dynamic response much closer to that of experimental tests, the parameters of joint clearance model, instead of using the designed values, were optimized by genetic algorithms approach. Finally, the optimized parameters were applied to simulate the dynamics response of model with oversized joint clearance fault according to the concluded parameter relation. The dynamics response of experimental test verified the effectiveness of this application.

  9. Estimation of hurdle clearance parameters using a monocular human motion tracking method.

    Krzeszowski, Tomasz; Przednowek, Krzysztof; Wiktorowicz, Krzysztof; Iskra, Janusz

    2016-09-01

    This paper presents a method of monocular human motion tracking for estimation of hurdle clearance kinematic parameters. The analysis involved 10 image sequences of five hurdlers at various training levels. Recording of the sequences was carried out under simulated starting conditions of a 110 m hurdle race. The parameters were estimated using the particle swarm optimization algorithm and they are based on analysis of the images recorded with a 100 Hz camera. The proposed method does not involve using any special clothes, markers, inertial sensors, etc. As the quality criteria, the mean absolute error and mean relative error were used. The level of computed errors justifies the use of this method to estimate hurdle clearance parameters. PMID:26838547

  10. Interscapular brown adipose tissue blood flow in the rat. Determination with 133xenon clearance compared to the microsphere method

    Astrup, A; Bülow, J; Madsen, J

    1984-01-01

    The xenon clearance method was adapted to continuous measurement of interscapular brown adipose tissue (ISBAT) blood flow in anesthetized rats. The ISBAT-blood partition coefficient for xenon was determined to 3.6 ml X g-1. The blood flow values obtained by Xe clearance were compared with flow...

  11. Comparison of 99mTc-MAG3 plasma clearance calculating methods [Bubeck and Russell (1996) methods] by single blood sampling

    This study was a comparison of the Bubeck and Russell (1996) methods, both of which are used to calculate 99mTc-MAG3 plasma clearance by single blood sampling in consideration of the distribution volume of patients. Quadratic polynominal approximation showed a strong correlation between the plasma clearance values obtained by the two methods. The quantitative values obtained by the Bubeck method tended to be lower than those obtained by the Russell (1996) method in the high clearance range. However, in the low to medium clearance range (below 250 ml/min/1.73 m2), there was almost no difference between the values, and the relationship between the values obtained by the two methods could be expressed by a straight regression line. A comparison of plasma clearance values according to difference in blood sampling time (35 min and 44 min sampling) in adults showed that there was no significant change in clearance regardless of the state of renal function. Correlation of the renal uptake rate obtained by the Bubeck method using a gamma camera could be expressed by a good straight regression line that passed around the origin of the coordinates. The results showed that, although the plasma clearance values obtained by the Bubeck method tended to be underestimated in the high clearance range compared with the values obtained by the Russell (1996) method, there was a very good correlation between the values obtained by the Bubeck method and renal uptake rate. (author)

  12. Measurement of glomerular filtration rate in adults: accuracy of five single-sample plasma clearance methods

    Rehling, M; Rabøl, A

    1989-01-01

    After an intravenous injection of a tracer that is removed from the body solely by filtration in the kidneys, the glomerular filtration rate (GFR) can be determined from its plasma clearance. The method requires a great number of blood samples but collection of urine is not needed. In the present...... determined simultaneously. Using these clearance values as reference the accuracy of six simplified methods were studied: five single-sample methods and one five-sample method. The standard error of estimate (SEE) of the single-sample methods ranged from 4.2 to 7.5 ml min-1 using EDTA, and from 3.8 to 6.3 ml...... min-1 using DTPA. SEE of the five-samples method was 3.0 ml min-1 (EDTA) and 3.1 ml min-1 (DTPA). The single-sample methods given by Christensen & Groth (1986) and by Tauxe (1986) are recommended for daily use, as SEE was small even at low GFR values. In patients with GFR less than 80 ml min-1, in...

  13. Large kidneys predict poor renal outcome in subjects with diabetes and chronic kidney disease.

    Vendrely Benoit; Beauvieux Marie-Christine; Barthe Nicole; Raffaitin Christelle; Montaudon Michel; Laurent François; Lasseur Catherine; Garcia Magalie; Rigalleau Vincent; Chauveau Philippe; Combe Christian; Gin Henri

    2010-01-01

    Abstract Background Renal hypertrophy occurs early in diabetic nephropathy, its later value is unknown. Do large kidneys still predict poor outcome in patients with diabetes and Chronic Kidney Disease (CKD)? Methods Seventy-five patients with diabetes and CKD according to a Glomerular Filtration Rate (GFR, by 51Cr-EDTA clearance) below 60 mL/min/1.73 m2 or an Albumin Excretion Rate above 30 mg/24 H, had an ultrasound imaging of the kidneys and were cooperatively followed during five years by ...

  14. Stress analysis method for clearance-fit joints with bearing-bypass loads

    Naik, R. A.; Crews, J. H., Jr.

    1989-01-01

    Within a multi-fastener joint, fastener holes may be subjected to the combined effects of bearing loads and loads that bypass the hole to be reacted elsewhere in the joint. The analysis of a joint subjected to search combined bearing and bypass loads is complicated by the usual clearance between the hole and the fastener. A simple analysis method for such clearance-fit joints subjected to bearing-bypass loading has been developed in the present study. It uses an inverse formulation with a linear elastic finite-element analysis. Conditions along the bolt-hole contact arc are specified by displacement constraint equations. The present method is simple to apply and can be implemented with most general purpose finite-element programs since it does not use complicated iterative-incremental procedures. The method was used to study the effects of bearing-bypass loading on bolt-hole contact angles and local stresses. In this study, a rigid, frictionless bolt was used with a plate having the properties of a quasi-isotropic graphite/epoxy laminate. Results showed that the contact angle as well as the peak stresses around the hole and their locations were strongly influenced by the ratio of bearing and bypass loads. For single contact, tension and compression bearing-bypass loading had opposite effects on the contact angle. For some compressive bearing-bypass loads, the hole tended to close on the fastener leading to dual contact. It was shown that dual contact reduces the stress concentration at the fastener and would, therefore, increase joint strength in compression. The results illustrate the general importance of accounting for bolt-hole clearance and contact to accurately compute local bolt-hole stresses for combined bearings and bypass loading.

  15. A simple method for the separation and quantitation of radiolabeled thyroid hormones in thyroxine clearance studies

    A method was developed to facilitate the separation and quantitation of radiolabeled thyroxine in plasma for thyroxine clearance studies. Following intravenous injection of radioactive thyroxine, the radiolabeled thyroid hormones were isolated from plasma protein and polar metabolites by solid phase extraction on a C18 sorbent bed. The individual thyroid hormones were then separated by ion-pair reversed phase chromatography and sequentially eluted through a UV detector and radiochromatographic detector. The radioactivity of individual radiolabeled thyroid hormones was corrected for recovery of carrier as determined from UV absorbance. The recoveries of thyroxine and 3,5,3'-triiodothyronine (T3) were 96% and 101%, respectively

  16. On the method for calculating unilateral renal clearance using 99mTc-MAG3 renal uptake ratio

    It has been reported that the renal clearance of 99mTc-mercaptoacetyltriglycine (99mTc-MAG3), a newly developed 99mTc-labeled renal tubular agent, effectively reflects renal plasma flow and serves as a useful parameter of renal function. In this study, we investigated on the method for calculating unilateral renal clearance of 99mTc-MAG3 using renal uptake ratio (RUR) and the conversion formula between RUR and renal clearance. Renography by 99mTc-MAG3 was performed in 38 cases with various renal functions and the renal clearance was estimated by three reported methods of one-point-venous-sampling. The results by Bubeck method were most consistent with the individual clinical data. The difference in the methodology of sample measurement or the type of scintillation camera did not affect the values of RUR. The correlation between renal clearance and RUR was not significantly different among the three groups of data acquisition time for RUR, i.e., 1-2 min., 1.5-2.5 min., and 2-3 min. after tracer injection. In summary, Bubeck method and RUR between 1-3 min. after injection seems to be suitable for the establishment or the conversion formula. Using this formula unilateral renal clearance of 99mTc-MAG3 could be reliably estimated without venous sampling. (author)

  17. Escaping the correction for body surface area when calculating glomerular filtration rate in children

    Piepsz, Amy; Tondeur, Marianne [CHU St. Pierre, Department of Radioisotopes, Brussels (Belgium); Ham, Hamphrey [University Hospital Ghent, Department of Nuclear Medicine, Ghent (Belgium)

    2008-09-15

    {sup 51}Cr ethylene diamine tetraacetic acid ({sup 51}Cr EDTA) clearance is nowadays considered as an accurate and reproducible method for measuring glomerular filtration rate (GFR) in children. Normal values in function of age, corrected for body surface area, have been recently updated. However, much criticism has been expressed about the validity of body surface area correction. The aim of the present paper was to present the normal GFR values, not corrected for body surface area, with the associated percentile curves. For that purpose, the same patients as in the previous paper were selected, namely those with no recent urinary tract infection, having a normal left to right {sup 99m}Tc MAG3 uptake ratio and a normal kidney morphology on the early parenchymal images. A single blood sample method was used for {sup 51}Cr EDTA clearance measurement. Clearance values, not corrected for body surface area, increased progressively up to the adolescence. The percentile curves were determined and allow, for a single patient, to estimate accurately the level of non-corrected clearance and the evolution with time, whatever the age. (orig.)

  18. Measurement of blood flow volume of ocular muscles by Xe-133 clearance method

    The blood flow volume of the ocular muscles was measured in 8 normal volunteers and 12 cases with miscellaneous opthalmic diseases by Xe-133 clearance method. The average of blood flow volume in the normal subjects was 7.45 ± 2.07 ml/min/100 g, and the blood flow volume ratio of right eye to left eye was 0.94 ± 0.07. The blood flow volume of the ocular muscles was decreased in the cases with stenosis of the internal carotid artery (n = 4, 4.3 ± 2.1 ml/min/100 g), glaucoma (n = 3, 4.7 ± 4.1 ml/min/100 g), arterial scleroses (n = 2, 3.8 ± 0.2 ml/min/100 g) and Takayasu's disease (n = 2, 5.6 ± 0.4 ml/min/100 g), and was increased in the acute inflammatory disease (n = 2, 21.5 ± 2.5 ml/min/100 g). Measurement of the blood flow volume of the ocular muscles using Xe-133 clearance method is useful to evaluate the circulatory abnormality in the ophthalmic diseases. (author)

  19. Radiolabel ratio method for measuring pulmonary clearance of intratracheal bacterial challenges

    Calculation of bacterial clearance is a fundamental step in any study of in situ lung antibacterial defenses. A method is described whereby about 85% of a radiolabeled bacterial inoculum was consistently introduced into the bronchopulmonary tree of a mouse by the intratracheal route. Mice were then killed 1 and 4 hours later; their lungs were removed aseptically and homogenized, and viable bacteria and radiolabel counts were determined. Radiolabel counts fell slowly, and more than 80% of the original radiolabel was still present in homogenized lung samples from animals sacrificed 4 hours after challenge. Bacteria/isotope ratios for the bacterial inoculum and homogenized lung samples from animals sacrificed immediately after challenge were very similar. Bacterial clearance values were the same whether computed from bacterial counts alone or according to a radiolabel ratio method whereby the change in the bacteria/isotope ratio in ground lung aliquots was divided by a similar ratio from bacteria used to inoculate animals. Some contamination resulted from oral streptococci being swept into the bronchopulmonary free during the aspiration process. This contamination was not a problem when penicillin was incorporated into the agar and penicillin-resistant strains were used for the bacterial challenges

  20. COMPARISON OF TWO METHODS TO INCREASE TIP CLEARANCE AND ITS EFFECT ON PERFORMANCE OF TURBOCHARGER CENTRIFUGAL COMPRESSOR STAGE

    SYED Noman Danish; MA Chaochen; YANG Ce; L(U) Wei

    2007-01-01

    Tip clearance between the blade tip and casing of a centrifugal compressor can be varied through two methods: by changing the blade height (M1) or by changing the casing diameter (M2). Numerical simulations are carried out to compare these two methods and their effect on the stage and impeller performance. The impeller and diffuser are connected through rotor Stator boundary using frozen rotor approach. Overall stage performance and the flow configuration have been investigated for nine tip clearance levels from no gap to 1 mm. Impeller and diffuser performances are also presented separately. It has been found that the overall and impeller performance are comparatively better for Ml below tip clearance of 0.5 mm whereas M2 is found advantageous above 0.5 mm of tip clearance. Both M1 and M2 show performance degradation with the increase in tip clearance. Two models have been proposed for the stage total pressure ratio and efficiency, which are found to be in agreement with experimental results. The impeller efficiency and the pressure ratio are found to be maximum at tip clearance of 0.1 mm for both the cases however minimum diffuser effectiveness is also observed at the same clearance level. Diffuser effectiveness is found to be maximum at zero gap for both cases. As it is practically impossible to have zero gap for unshrouded impellers so it is concluded that the Optimum thickness is 0.5 mm onwards for Ml and 0.5 mm for M2 in terms of diffuser effectiveness. Mass averaged flow parameters, entropy, blade loading diagram and relative pressure fields are presented, showing the loss production within the impeller passage with tip clearance.

  1. Method to improve the blade tip-timing accuracy of fiber bundle sensor under varying tip clearance

    Duan, Fajie; Zhang, Jilong; Jiang, Jiajia; Guo, Haotian; Ye, Dechao

    2016-01-01

    Blade vibration measurement based on the blade tip-timing method has become an industry-standard procedure. Fiber bundle sensors are widely used for tip-timing measurement. However, the variation of clearance between the sensor and the blade will bring a tip-timing error to fiber bundle sensors due to the change in signal amplitude. This article presents methods based on software and hardware to reduce the error caused by the tip clearance change. The software method utilizes both the rising and falling edges of the tip-timing signal to determine the blade arrival time, and a calibration process suitable for asymmetric tip-timing signals is presented. The hardware method uses an automatic gain control circuit to stabilize the signal amplitude. Experiments are conducted and the results prove that both methods can effectively reduce the impact of tip clearance variation on the blade tip-timing and improve the accuracy of measurements.

  2. Measuring glomerular filtration rate using 51Cr-EDTA: body surface area normalization before or after Bröchner-Mortensen correction?

    Pottel, Hans; Hoste, Liesbeth; De Waele, Liesbeth; Braat, Elke; Baete, Kristof; Goffin, Karolien; Levtchenko, Elena; Gheysens, Olivier

    2014-01-01

    Guidelines for measuring glomerular filtration rate (GFR) using Cr-EDTA require normalizing of GFR for body surface area (BSA) before applying the Bröchner-Mortensen (BM) correction. The guideline explicitly mentions the importance of performing BSA normalization before BM correction and that this is particularly important in children in whom the effects of BSA normalization are largest.

  3. Novel Cytochrome P450 Reaction Phenotyping for Low-Clearance Compounds Using the Hepatocyte Relay Method.

    Yang, Xin; Atkinson, Karen; Di, Li

    2016-03-01

    A novel cytochrome P450 (P450) reaction phenotyping method for low-clearance compounds has been developed for eight P450 enzymes (CYP1A2, 2B6, 2D6, 2C8, 2C9, 2C19, 3A, and 3A4) and pan-cytochrome using the hepatocyte relay approach. Selective mechanism-based inhibitors were used to inactivate the individual P450 enzymes during preincubation, and inactivators were removed from the incubation before adding substrates to minimize reversible inhibition and maximize inhibitor specificity. The inhibitors were quite selective for specific P450 isoforms using the following inhibitor concentrations and preincubation times: furafylline (1 µM, 15 minutes) for CYP1A2, phencyclidine (20 µM, 15 minutes) for 2B6, paroxetine (1.8 µM, 15 minutes) for CYP2D6, gemfibrozil glucuronide (100 µM, 30 minutes) for 2C8, tienilic acid (15 µM, 30 minutes) for 2C9, esomeprazole (8 µM, 15 minutes) for 2C19, troleandomycin (25 µM, 15 minutes) for 3A4/5, CYP3cide (2 µM, 15 minutes) for 3A4, and 1-aminobenzotriazole (1 mM, 30 minutes) supplemented with tienilic acid (15 µM, 30 minutes) for pan-cytochrome. The inhibitors were successfully applied to the hepatocyte relay method in a 48-well format for P450 reaction phenotyping of low-clearance compounds. This novel method provides a new approach for determining the fraction metabolized of low-turnover compounds that are otherwise challenging with the traditional methods, such as chemical inhibitors with human liver microsomes and hepatocytes or human recombinant P450 enzymes. PMID:26700955

  4. The parasite clearance curve

    White NJ

    2011-01-01

    Abstract Parasite clearance rates are important measures of anti-malarial drug efficacy. They are particularly important in the assessment of artemisinin resistance. The slope of the log-linear segment in the middle of the parasite clearance curve has the least inter-individual variance and is the focus of therapeutic assessment. The factors affecting parasite clearance are reviewed. Methods of presentation and the approaches to analysis are discussed.

  5. Optical Method for Real-Time Turbine Blade Tip Clearance Measurement Project

    National Aeronautics and Space Administration — Monitoring and controlling blade tip clearance of high pressure turbines are important for maintaining the integrity of the engine during its operating points and...

  6. Calculating Clearances for Manipulators

    Copeland, E. L.; Peticolas, J. D.; Ray, L. D.

    1983-01-01

    Set of algorithms rapidly calculates minimum safe clearances for remote manipulators. Such calculations are used in design of trajectories for manipulators to ensure they do not accidentally strike surrounding objects. Structural parts are considered as cylindrical shells having circular plane areas for ends. Clearance calculation method offers special benefits in industrial robotics, particularly in automated machining.

  7. Beta-2-microglobulin excretion: an indicator of long term nephrotoxicity during cis-platinum treatment?

    Sørensen, P G; Nissen, Mogens Holst; Groth, S; Rørth, M

    1985-01-01

    To evaluate the value of beta-2-microglobulin as an indicator of acute and long-term cis-platinum-induced nephrotoxicity, 51Cr-EDTA clearance and serum concentration and urinary excretion of beta-2-microglobulin were measured in 18 patients treated with a regimen including cis-platinum. Before......-microglobulin remained unchanged. The decrease in 51Cr-EDTA clearance was not correlated to either the peak increase in the beta-2-microglobulin excretion or to the time of occurrence of the peak (R = 0.3). Thus, it is not possible to predict the long-term nephrotoxicity of cis-platinum by measuring the beta-2...

  8. Monitoring kidney function in type 2 diabetic patients with incipient and overt diabetic nephropathy

    Rossing, Peter; Rossing, Kasper; Gaede, Peter;

    2006-01-01

    The purpose of this study was to assess agreement between glomerular filtration rate (GFR) and the decline in GFR estimated with the Modification of Diet in Renal Disease (MDRD) Study Group equation or the Cockcroft-Gault formula and measured by the plasma clearance of 51Cr-EDTA.......The purpose of this study was to assess agreement between glomerular filtration rate (GFR) and the decline in GFR estimated with the Modification of Diet in Renal Disease (MDRD) Study Group equation or the Cockcroft-Gault formula and measured by the plasma clearance of 51Cr-EDTA....

  9. Mucociliary clearance

    Munkholm, Mathias; Mortensen, Jann

    2014-01-01

    Mucociliary clearance has long been known to be a significant innate defence mechanism against inhaled microbes and irritants. Important knowledge has been gathered regarding the anatomy and physiology of this system, and in recent years, extensive studies of the pathophysiology related to lung...... diseases characterized by defective mucus clearance have resulted in a variety of therapies, which might be able to enhance clearance from the lungs. In addition, ways to study in vivo mucociliary clearance in humans have been developed. This can be used as a means to assess the effect of different...... pharmacological interventions on clearance rate, to study the importance of defective mucus clearance in different lung diseases or as a diagnostic tool in the work-up of patients with recurrent airway diseases. The aim of this review is to provide an overview of the anatomy, physiology, pathophysiology, and...

  10. Method and system for measuring gate valve clearances and seating force

    Casada, Donald A.; Haynes, Howard D.; Moyers, John C.; Stewart, Brian K.

    1996-01-01

    Valve clearances and seating force, as well as other valve operational parameters, are determined by measuring valve stem rotation during opening and closing operations of a translatable gate valve. The magnitude of the stem rotation, and the relative difference between the stem rotation on opening and closing provides valuable data on the valve internals in a non-intrusive manner.

  11. Catchment conceptualisation for examining applicability of chloride mass balance method in an area of historical forest clearance

    H. Guan; Love, A.; C. T. Simmons; Ding, Z; Hutson, J

    2009-01-01

    Among various approaches for estimating groundwater recharge, chloride mass balance (CMB) method is one of the most frequently used, in particular, for arid and semiarid regions. Widespread native vegetation clearance, common history in many areas globally, has changed land surface boundary condition, posing a question whether the current system has reached new chloride equilibrium for CMB application. To examine CMB applicability for catchments, conceptual catchment types of various chloride...

  12. Catchment conceptualisation for examining applicability of chloride mass balance method in an area with historical forest clearance

    H. Guan; Love, A. J.; C. T. Simmons; Hutson, J; Ding, Z

    2010-01-01

    Of the various approaches for estimating groundwater recharge, the chloride mass balance (CMB) method is one of the most frequently used, especially for arid and semiarid regions. Widespread native vegetation clearance, common in many areas globally, has changed the land surface boundary condition, posing the question as to whether the current system has reached new chloride equilibrium, required for a CMB application. Although a one-dimensional CMB can be applied at a point where the water a...

  13. PC-1 amino acid variant (K121Q) has no impact on progression of diabetic nephropathy in type 1 diabetic patients

    Jacobsen, Peter; Grarup, Niels; Tarnow, Lise; Parving, Hans-Henrik; Pedersen, Oluf

    2002-01-01

    Recently, an amino acid variant (K121Q) in the glycoprotein PC-1 (Q allele) has been associated with faster progression of diabetic nephropathy, as estimated by calculated creatinine clearance. We tested the impact of the PC-1 (K121Q) variant on loss of glomerular filtration rate (GFR) measured b...... the [(51)Cr]EDTA plasma clearance technique....

  14. In situ method for measurements of community clearance rate on shallow water bivalve populations

    Hansen, Benni W.; Dolmer, Per; Vismann, Bent

    2011-01-01

    air lift connected to a SCUBA diver pressure tank generating a continuous and gentle water circulation. This ensures a complete mixture of suspended particles, and thereby, a maximum filtration by the bivalves. An in situ fluorometer was mounted to record plant pigment reduction due to mussel...... clearance in real-time. To calibrate the in situ fluorometer triplicate water samples were obtained initially in each of the bivalve filtration measurements. The water samples were filtrated, extracted, and later analyzed for plant pigment concentration on a laboratory spectrophotometer. The main conclusion......An open-top chamber was designed for measuring ambient community clearance rate on undisturbed bivalve populations in the field. The chamber was pressed 5-10 cm down in the sediment on the mussel bed. It holds approximately 30-40 cm water column equal to a volume of 43-77 L. It was provided with an...

  15. Experimental and clinical studies on dynamic circulation of intervertebral discs by radiation clearance method

    Few studies on the mechanism of dynamic circulation in intervertebral discs are reported. The purpose of this study is to clarify the dynamic mechanism of circulation in the lumbar intervertebra discs with radioisotope clearance, experimentally and clinically. Rabbits were used as experimental animals and were divided into two groups, normal and artificially injured. I131-sodium was injected into them and the clearance was followed. Injected I131-sodium was cleared in the order of; 1) discs with injured annulus fibrosus, 2) discs with injection of α-chymotrypsin, 3) discs with injuries in the border between vertebral body and annulus fibrosus, 4) and normal discs. Human degenerated discs were also used for this study. In the clinical cases, I131-sodium was cleared faster in the degenerated discs than in the normal. The pathway for I131-sodium to be cleared is supposed to be extravascular and interstitial spaces in the disc. (author)

  16. Analysis of Robot Accuracy Assessed via its Joint Clearance by Virtual Prototyping Method

    GUO Ling; WANG Li-hong; ZHANG Yu-ru

    2004-01-01

    This paper discusses how joint clearance influences robot end effector positioning accuracy and a robot accuracy analysis approach based on a virtual prototype is proposed. First, a 5-DOF( Degree of freedom) rneurosurgery robot was introduced. Then we built its virtual prototype, made movement planning and measured the manipulator tip accuracy, through which this robot accuracy portrait was obtained. Finally,in order to validate the robot accuracy analysis approach which is based on a virtual prototype, the result was compared with that from a model built by robot forward kinematics and robot differential kinematics.The robot accuracy analysis approach presented in this paper gives a new way to enhance robot design quality, and help to optimize the control and programming of the robot.

  17. Effect of renal nerve activity on tubular sodium and water reabsorption in dog kidneys as determined by the lithium clearance method

    Abildgaard, U; Holstein-Rathlou, N H; Leyssac, P P

    1986-01-01

    reabsorption of sodium and water increased significantly by 9 +/- 2% and 8 +/- 2%. Low-frequency electrical stimulation of the distal nerve bundle of the denervated kidney caused a significant decrease in urine flow rate (37 +/- 6%), sodium clearance (31 +/- 4%), lithium clearance (17 +/- 5%) and in fractional......The reliability of the lithium clearance method in studies of the effect of renal nerve activity upon tubular sodium and water handling in the dog kidney was investigated. Following unilateral acute surgical denervation of the kidney a significant increase in urinary flow rate (40 +/- 7%), sodium...... lithium clearance (18 +/- 5%). Calculated absolute proximal reabsorption rate increased significantly by 17 +/- 3%, while calculated absolute rates of distal sodium and water reabsorption decreased significantly by 16 +/- 5% and 16 +/- 5%. These changes in tubular sodium and water reabsorption during...

  18. Study on clearance system

    The clearance system is a legal word to define as 'the waste not requiring treatment as radioactive waste' on the regulatory control. JNES supports NISA on the approval and the confirmation of clearance measurement by the operator. The objective of this study is to establish technical base of the validation method of the clearance measurement for various objects. In reactor facilities, the statistical sampling measurement technique may be applied to large scale objects. In this study, the criteria of the techniques were examined, and the strategy for setting of radioactivity concentration evaluation level was prepared. In uranium processing facilities, simulation sources to apply to a validity confirmation examination of the measuring equipment were made, and these applicability and problem were studied. The method of the validity evaluation of the performance confirmation of the measuring equipment was devised by measurement experiment using this source. The manual for unexpected incidents which maintained in FY2011 was reviced by reflection of the experience of the radioactivity concentration measurement of disaster waste contaminated by the accident of Fukushima Dai-ichi NPS. JNES also supports NISA technically for the issue on influence of fall out from Fukushima Dai-ichi NPS on clearance system and NR system. In addition, the latest situation of a clearance system operated in Europe was studied. (author)

  19. Validation of the flow-through chamber (FTC and steady-state (SS methods for clearance rate measurements in bivalves

    Poul S. Larsen

    2011-09-01

    To obtain precise and reliable laboratory clearance rate (filtration rate measurements with the ‘flow-through chamber method’ (FTC the design must ensure that only inflow water reaches the bivalve's inhalant aperture and that exit flow is fully mixed. As earlier recommended these prerequisites can be checked by a plot of clearance rate (CR versus increasing through-flow (Fl to reach a plateau, which is the true CR, but we also recommend to plot percent particles cleared versus reciprocal through-flow where the plateau becomes the straight line CR/Fl, and we emphasize that the percent of particles cleared is in itself neither a criterion for valid CR measurement, nor an indicator of appropriate ‘chamber geometry’ as hitherto adapted in many studies. For the ‘steady-state method’ (SS, the design must ensure that inflow water becomes fully mixed with the bivalve's excurrent flow to establish a uniform chamber concentration prevailing at its incurrent flow and at the chamber outlet. These prerequisites can be checked by a plot of CR versus increasing Fl, which should give the true CR at all through-flows. Theoretically, the experimental uncertainty of CR for a given accuracy of concentration measurements depends on the percent reduction in particle concentration (100×P from inlet to outlet of the ideal ‘chamber geomety’. For FTC, it decreases with increasing values of P while for SS it first decreases but then increases again, suggesting the use of an intermediate value of P. In practice, the optimal value of P may depend on the given ‘chamber geometry’. The fundamental differences between the FTC and the SS methods and practical guidelines for their use are pointed out, and new data on CR for the blue mussel, Mytilus edulis, illustrate a design and use of the SS method which may be employed in e.g. long-term growth experiments at constant algal concentrations.

  20. Study on clearance system

    The clearance system is a legal system to release 'the radioactive waste not requiring treatment as radioactive waste' from the regulatory control. JNES supports NISA on approval and confirmation of clearance measurement and judgment developed by the operator. The objective of this study is to establish technical base of the validation method of the clearance measurement for various objects. In reactor facilities, the bulk measurement technique or the statistical sampling measurement technique may be applied to large scale objects or concrete walls. In this study, the criteria of those techniques were examined. In uranium processing facilities, it is important to confirm surface state of the object in case of detecting alpha rays. The result of the examination about the influence of the surface rust in the uranium clearance measurement by the alpha ray measurement showed that the pollution was distributed in rust layer uniformly. This result will be reflected to the revision of the Ministerial Ordinance on Clearance in 2011FY. To develop a manual for unexpected incidents, the response procedure for an unexpected incident was prepared, including a response system. (author)

  1. Study on the delay phenomenon in various types of deltopectoral flaps using the xenon-133 clearance method

    During the past five years, we have measured the skin blood flow in various types of deltopectoral flaps by the Xenon-133 clearance method and have studied the delay phenomenon and optimum transfer time. The clearance rate of the first component, indicating the skin blood flow, was compared individually before and successively after a delay procedure at the deltoid region by taking the pre-operative value as 100 percent. The changes in the skin blood flow in the flaps were studied for the following five groups in order to ascertain if there were any differences in recovery patterns. 1) Type I (U-shaped, undermined D-P flap): In 25 cases, the regional blood flow decreased once, recovering to control values within one to three weeks. In some cases, the recovery exceeded the control values after 10 days. 2) Type II (U-shaped, raised deltoid flap): In 18 cases, recovery of the skin blood flow was slower than in Type I, reaching control values in the second to third week. 3) Type III (lining D-P flap with a split-skin graft): In 10 cases, the skin blood flow was better than in Type I, with recovery exceeding control values after one week and continuing to increase with time. 4) Type IV (tubed D-P flap): Recovery of the skin blood flow was observed at two to four days showing better than in Type I. This procedure was considered to be highly reliable and to have wide indications. 5) Type V (bipedicled, raised D-P flap): Recovery of the skin blood flow was higher in the base than in the deltoid region, but the difference gradually decreased post-operatively with time. The time of the lateral incision was found to be critical because of the influence of the possibility of occurrence of a post-operative inversion of the recovery rate. (author)

  2. Study on clearance system

    The clearance system is a legal system to release 'the radioactive waste not requiring treatment as radioactive waste' from the regulatory control. JNES supports Nuclear Regulatory Agency on approval and confirmation of clearance measurement and judgment developed by the operator. The objective of this study is to establish technical base of the validation method of the clearance measurement for various objects. In uranium processing facilities, simulation sources emitting alpha-rays is used in a validity confirmation examination of the measuring equipment. In this study, these sources were examined by measuring alpha and beta spectra to evaluate the applicability and problem of these sources. In addition, the measuring method detecting gamma-rays was examined. This method can be applied to complicated objects. As a part to develop a manual for unexpected incidents in clearance system, a quick method for measurement of Strontium 90 was examined. In addition, the measuring methods for the judgment of the influence of fallout and for NR (Non-Radioactive) confirmation were examined. (author)

  3. Dynamic Ground Clearance

    Hamache, Violette

    2013-01-01

    The purpose of this work is to develop a test method which will consider the variation of the ground clearance when driving, the so-called dynamic ground clearance. This has been done through the analysis of a specific application: the tractors in grain used in Brazil. Series of real life tests are run in order to obtain data on the tire compressions and the suspension travels. The tractor used is a 6x4 and is loaded with a trailer. When investigating critical cases, the minimum dynamic groun...

  4. Catchment conceptualisation for examining applicability of chloride mass balance method in an area with historical forest clearance

    H. Guan

    2010-07-01

    Full Text Available Of the various approaches for estimating groundwater recharge, the chloride mass balance (CMB method is one of the most frequently used, especially for arid and semiarid regions. Widespread native vegetation clearance, common in many areas globally, has changed the land surface boundary condition, posing the question as to whether the current system has reached new chloride equilibrium, required for a CMB application. Although a one-dimensional CMB can be applied at a point where the water and chloride fluxes are locally in steady state, the CMB method is usually applied at a catchment scale owing to significant lateral flows in mountains. The applicability of the CMB method to several conceptual catchment types of various chloride equilibrium conditions is examined. The conceptualisation, combined with some local climate conditions, is shown to be useful in assessing whether or not a catchment has reached new chloride equilibrium. The six conceptual catchment types are tested with eleven selected catchments in the Mount Lofty Ranges (MLR, a coastal hilly area in South Australia having experienced widespread historical forest clearance. The results show that six of the eleven catchments match a type VI chloride balance condition (chloride non-equilibrium with a gaining stream, with the ratios of stream chloride output (O over atmospheric chloride input (I, or catchment chloride O/I ratios, ranging from 2 to 4. Two catchments match a type V chloride balance condition (chloride non-equilibrium with a losing stream, with catchment chloride O/I ratios about 0.5. For these type V and type VI catchments, the CMB method is not applicable. The results also suggest that neither a chloride O/I ratio less than one nor a low seasonal fluctuation of streamflow chloride concentration (a factor below 4 guarantees a chloride equilibrium condition in the study area. A large chloride O/I value (above one and a large fluctuation of streamflow chloride

  5. Determination of the liver clearance of 131 J-bromosulfophthalein with partially shielded whole-body counter - method and clinical results

    The aim of the study consisted first of all in working out a procedure to determine the liver clearance of 131J-bromosulfophthalien according to the Oberhausen method and to inquire into the usability and sphere of validity of the Oberhausen approach. Subsequently a collective of patients was to be tested in order to find out whether it is possible with the aid of the clearance value to differentiate between persons with healthy livers and persons with liver disturbances respectively to assess the severity of a functional liver disorder. As the investigations were carried through as a part of the clinical routine, the information obtained by the clearance concept as compared to sequential scintiscanning and compartment analysis was to be investigated at the same time. (orig./MG)

  6. Prediction of two-sample 99mTc-diethylene triamine pentaacetic acid plasma clearance from single-sample method

    The objective of this study was to develop an equation to predict dual plasma sample method (DPSM) 99mTc-diethylene triamine pentaacetic acid (99mTc-DTPA) plasma clearance from single plasma sample method (SPSM), and to clarify the condition in which DPSM can be substituted by SPSM in measurement of glomerular filtration rate (GFR). Patients with chronic kidney disease (CKD) were selected. Watson modified Christensen and Groth equation was used to calculate 99mTc-DTPA plasma clearance by SPSM (sGFR). The equation recommended by the Nephrourology Committee of the Society of Nuclear Medicine was used to calculate 99mTc-DTPA plasma clearance by DPSM (tGFR) in each patient. The difference between sGFR and tGFR was expressed as percent of the average of these two methods, and tGFR was predicted from sGFR. Plasma creatinine was measured by the kinetic picrate method, and GFR estimated by abbreviated modification of diet in renal disease (MDRD) equation (aGFR) and Cockcroft-Gault equation (cGFR) were evaluated as criteria in selection of DPSM and SPSM. Three hundred and sixty-nine patients with CKD were selected (208 male and 161 female). The average age and body weight were 51.4±15.5 years and 67.2±12.5 kg, respectively. The causes of CKD were glomerular disease, renal arterial stenosis, chronic tubulointerstitial disease, and other causes or causes unknown. The average tGFR was 62.9±36.5 ml/min/1.73 m2, ranging from 1-180 ml/min/1.73 m2. sGFR was significantly correlated with tGFR (r=0.9194, p2; in contrast, then tGFR was±30 ml/min/1.73 m2, the difference was constant (-1.1%, 95% confidence interval -18.3%, 16.1%), and tGFR could be predicted from sGFR using the equation: predicted tGFR (ml/min/1.73 m2)=7 4244+0.7318 x sGFR+0.0022 x sGFR2 (n=299, r2=0.9428, p2, the diagnostic sensitivity of a cut off value of aGFR=45 ml/min/1.73 m2 was 91.8%, and recommended as a criterion in the selection of DPSM and SPSM. When GFR ≥30 ml/min/1.73 m2, tGFR can be predicted from s

  7. A single-injection, two-sample method for measuring renal 99mTc-MAG3 clearance in both children and adults

    We present a method for estimating 99mTc-MAG3 clearance from both a single injection and two blood samples that is valid for both adults and children. It was obtained by fitting a scaled two-compartment model (having only two adjustable parameters) to adult and pediatric data from multiple centers

  8. Identifying Minefields and Verifying Clearance: Adapting Statistical Methods for UXO Target Detection

    Gilbert, Richard O.; O' Brien, Robert F.; Wilson, John E.; Pulsipher, Brent A.; McKinstry, Craig A.; J. T. Broach, Russell S. Harmon, John H. Holloway, Jr.

    2003-09-01

    It may not be feasible to completely survey large tracts of land suspected of containing minefields. It is desirable to develop a characterization protocol that will confidently identify minefields within these large land tracts if they exist. Naturally, surveying areas of greatest concern and most likely locations would be necessary but will not provide the needed confidence that an unknown minefield had not eluded detection. Once minefields are detected, methods are needed to bound the area that will require detailed mine detection surveys. The US Department of Defense Strategic Environmental Research and Development Program (SERDP) is sponsoring the development of statistical survey methods and tools for detecting potential UXO targets. These methods may be directly applicable to demining efforts. Statistical methods are employed to determine the optimal geophysical survey transect spacing to have confidence of detecting target areas of a critical size, shape, and anomaly density. Other methods under development determine the proportion of a land area that must be surveyed to confidently conclude that there are no UXO present. Adaptive sampling schemes are also being developed as an approach for bounding the target areas. These methods and tools will be presented and the status of relevant research in this area will be discussed.

  9. Prediction of renal function (GFR) from cystatin C and creatinine in children: Body cell mass increases accuracy of the estimate

    Andersen, Trine Borup; Jødal, Lars; Bøgsted, Martin; J. Erlandsen, Erland; Eskild-Jensen, Anni; Frøkiær, Jørgen; Brøchner-Mortensen, Jens

    using robust regression in a forward, stepwise procedure. GFR (mL/min) was the dependent variable. The accuracy and precision of the prediction model were compared to other prediction models from the literature, using k-fold cross-validation. Local constants and coefficients were calculated for all...... glomerular filtration followed by catabolization in the tubular cells. We hypothesized that production rate is proportional to body cell mass (BCM) and inferred GFR (mL/min) to be proportional to BCM/CysC. MATERIAL AND METHODS: GFR was determined with 51Cr-EDTA-clearance in 131 children (52 girls, 79 boys....... CONCLUSION: The new equation predicts GFR with higher accuracy than other equations. Endogenous methods are, however, still not accurate enough to replace exogenous markers when GFR must be determined with high accuracy....

  10. Catchment conceptualisation for examining applicability of chloride mass balance method in an area of historical forest clearance

    H. Guan

    2009-11-01

    Full Text Available Among various approaches for estimating groundwater recharge, chloride mass balance (CMB method is one of the most frequently used, in particular, for arid and semiarid regions. Widespread native vegetation clearance, common history in many areas globally, has changed land surface boundary condition, posing a question whether the current system has reached new chloride equilibrium for CMB application. To examine CMB applicability for catchments, conceptual catchment types of various chloride equilibrium conditions are defined. The conceptualization, combined with some local climate conditions, is demonstrated to be useful in examining whether a catchment has reached new chloride equilibrium. The six conceptual catchment types are tested with eleven selected catchments in the Mount Lofty Ranges (MLR, a coastal hilly area in South Australia having experienced historical widespread forest clearance. The results show that six of the eleven catchments match type VI chloride balance condition (chloride non-equilibrium with a gaining stream, with the ratio of stream chloride output over atmospheric chloride input (catchment chloride O/I ranging from 2 to 4. Two catchments match type V chloride balance condition (chloride non-equilibrium with a losing stream, with catchment chloride O/I values about 0.5. For these catchments, the CMB method is not appropriate to apply. The results also suggest that neither a below-one chloride O/I value nor a low seasonal fluctuation of streamflow chloride concentration (a factor below 4 guarantees a chloride equilibrium condition in the study area. But a large chloride O/I value (above one and a large fluctuation of streamflow chloride concentration (a factor of 10 and above generally indicates either a chloride disequilibrium, or cross-catchment water transfer, or both, for which CMB is not applicable. Based on the regression between chloride O/I values and annual precipitation for type VI catchments, a catchment with

  11. Comparison of glomerular filtration rates by dynamic renal scintigraphy and dual-plasma sample clearance method in diabetic nephropathy

    Objective: To evaluate the accuracy of renal scintigraphy for the estimation of glomerular filtration rates (dGFR) in patients with diabetic nephropathy as compared to the conventional dual-plasma sample clearance method (pscGFR). Methods: Forty-six patients with diabetic nephropathy underwent both dynamic renal scintigraphy and dual-plasma sample measurement after 99Tcm-DTPA injection. Paired student t-test and correlation analysis were performed to compare dGFR and pscGFR (normalized to body surface area, 1.73 m-2). Results: The mean dGFR was higher than mean pscGFR ((51.08±26.78)ml·min-1 vs (44.06±29.43)ml·min-1, t=4.209, P=0.000). The dGFR correlated with pscGFR (r=0.923, P=0.000) linearly (regression equation: pscGFR=1.015 x dGFR -7.773, F=254.656, P=0.000). Conclusions: dGFR correlated well with pscGFR. Although it could not absolutely replace the latter in patients with diabetic nephropathy, dGFR could reasonably evaluate the filtration function for these patients. (authors)

  12. 50 years follow-up on plasma creatinine levels after spinal cord injury

    Elmelund, Marlene; Oturai, P S; Biering-Sørensen, F

    2014-01-01

    119 patients with a traumatic SCI during the years 1944-1975 were included in the study. P-creatinine measurements, results from renography and glomerular filtration rate (GFR) measured with 51Cr-EDTA clearance were obtained from medical records and analyzed using a linear mixed model and linear...... regression analyses. RESULTS: When compared with median p-creatinine level in the first 5-year period after injury, the level of p-creatinine was stable throughout the first 30 years and decreased significantly after the 30th until 45th year post injury. Only patients with a functional distribution outside......STUDY DESIGN: Retrospective chart review. OBJECTIVES: To investigate the role of plasma creatinine (p-creatinine) in monitoring renal deterioration in patients up to 50 years after spinal cord injury (SCI). SETTING: The Clinic for Spinal Cord Injuries, Rigshospitalet, Denmark. METHODS: A total of...

  13. GFR Prediction From Cystatin C and Creatinine in Children

    Andersen, Trine Borup; Jødal, Lars; Boegsted, Martin; Erlandsen, Erland Jørn; Morsing, Anni; Frøkiær, Jørgen; Brøchner-Mortensen, Jens

    2012-01-01

    area, and SCr is serum creatinine level. The accuracy and precision of these models were compared with 7 previously published prediction models using random subsampling cross-validation. Local constants and coefficients were calculated for all models. Root mean square error, R2, and percentage of...... predictions within ±10% and ±30% of the reference GFR were calculated for all models. Based on 1,000 runs of the cross-validation procedure, median values and 2.5th and 97.5th quantiles of the validation parameters were calculated. Reference Test GFR measurement by 51Cr-EDTA clearance. Results The BCM model...... GFR <60 mL/min/1.73 m2. Lack of independent validation cohort. Conclusions The novel BCM model predicts GFR with higher accuracy than previously published models. The weight model is almost as accurate as the BCM model and allows for GFR estimation without knowledge of BCM. However, endogenous methods...

  14. Renal impairment and late toxicity in germ-cell cancer survivors

    Lauritsen, J.; Mortensen, M. S.; Kier, M. G. G.; Christensen, I. J.; Agerbaek, M.; Gupta, Ramneek; Daugaard, G.

    2015-01-01

    cohort of germ-cell cancer survivors. Patients and methods BEP-treated patients (N = 1206) were identified in the Danish DaTeCa database, and merged with national registers to identify late toxicity. GFR were measured (51Cr-EDTA clearance) before and after treatment and at 1, 3 and 5-year follow-up. The...... renal function, had an increased risk of CVD and death. This risk depended on chronic kidney disease stage before treatment but not after treatment. ΔGFR had no influence on risk of late toxicity [death: hazard ratio (HR) 1.06, P = 0.50; CVD: HR 0.97, P = 0.61]. Conclusions Renal function after BEP is...

  15. Clearance gap flow: extended pneumatic measurements and simulations by discontinuous Galerkin finite element method

    Hála Jindřich

    2016-01-01

    Full Text Available In the present paper, new results of measurements of the compressible viscous fluid flow in narrow channels with parallel walls under the conditions of aerodynamic choking are presented. Investigation was carried out using the improved test section with enhanced capability to accurately set the parallelism of the channel walls. The measurements were performed for the channels of the dimensions: length 100 mm, width 100 mm and for various heights in the range from 0.5 mm to 4 mm. The results in the form of distribution of the static pressure along the channel axis including the detailed study of the influence of the deviation from parallelism of the channel walls are compared with previous measurements and with numerical simulations performed using an in-house code based on Favre averaged system of Navier-Stokes equations completed with turbulence model of Spalart and Allmaras and a modification of production term according to Langtry and Sjolander. The spatial discretization of the governing equations is performed using the discontinuous Galerkin finite element method which ensures high order spatial accuracy of the numerical solution.

  16. Clearance gap flow: extended pneumatic measurements and simulations by discontinuous Galerkin finite element method

    Hála, Jindřich; Luxa, Martin; Bublík, Ondřej; Prausová, Helena; Vimmr, Jan

    2016-03-01

    In the present paper, new results of measurements of the compressible viscous fluid flow in narrow channels with parallel walls under the conditions of aerodynamic choking are presented. Investigation was carried out using the improved test section with enhanced capability to accurately set the parallelism of the channel walls. The measurements were performed for the channels of the dimensions: length 100 mm, width 100 mm and for various heights in the range from 0.5 mm to 4 mm. The results in the form of distribution of the static pressure along the channel axis including the detailed study of the influence of the deviation from parallelism of the channel walls are compared with previous measurements and with numerical simulations performed using an in-house code based on Favre averaged system of Navier-Stokes equations completed with turbulence model of Spalart and Allmaras and a modification of production term according to Langtry and Sjolander. The spatial discretization of the governing equations is performed using the discontinuous Galerkin finite element method which ensures high order spatial accuracy of the numerical solution.

  17. In vitro catheter and sorbent-based method for clearance of radiocontrast material during cerebral interventions

    Background: Contrast-induced acute kidney injury is a severe condition resulting from the use of radiology contrast in patients with predisposing factors. Hypothesis: We hypothesized that a novel system including a device containing polymer resin sorbent beads and a custom-made suctioning catheter could efficiently remove contrast from an in vitro novel model of circulatory system (MOCS) mimicking the cerebral circulation. Methods: A custom-made catheter was built and optimized for cerebral venous approach. The efficiency of a system made of a polymer resin sorbent beads column (CST 401, Cytosorbents) and this particular catheter was tested in the MOCS running a solution composed of 0.9% saline and radio-contrast. During two series of 18 cycles of first-pass experiments we assessed the catheter's suctioning efficiency and the system's ability to clear radio-contrast injected into the MOCS's cerebral arterial segment. We also assessed the functioning and reliability of the MOCS. Results: Mean suctioning efficiency of the catheter was 84% ± 24%. The polymer sorbent column contrast removal rate was initially 96% and gradually decreased with subsequent cycles in a linear fashion during an experiment lasting approximately 90 minutes. The MOCS had a reliability of 0.9946×min−1 where 1 × min−1 was the optimum value. Conclusion: A system including a polymer resin sorbent beads column and a custom-made suctioning catheter had an excellent initial efficiency in quickly removing contrast from an artificial MOCS mimicking the cerebral circulation. MOCS is an inexpensive and relatively reliable custom-made system that can be used for training or testing purposes

  18. In vitro catheter and sorbent-based method for clearance of radiocontrast material during cerebral interventions

    Angheloiu, George O., E-mail: goangheloiu@drmc.org [Heart and Vascular Institute, University of Pittsburgh Medical Center, Pittsburgh, PA (United States); Department of Cardiology, Dubois Regional Medical Center, Dubois, PA (United States); Hänscheid, Heribert; Reiners, Christoph [Department of Nuclear Medicine, University of Würzburg, Würzburg (Germany); Anderson, William D. [Cardiology Department, Exempla Healthcare, Denver, CO (United States); Kellum, John A. [CRISMA Center, Department of Critical Care Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA (United States)

    2013-07-15

    Background: Contrast-induced acute kidney injury is a severe condition resulting from the use of radiology contrast in patients with predisposing factors. Hypothesis: We hypothesized that a novel system including a device containing polymer resin sorbent beads and a custom-made suctioning catheter could efficiently remove contrast from an in vitro novel model of circulatory system (MOCS) mimicking the cerebral circulation. Methods: A custom-made catheter was built and optimized for cerebral venous approach. The efficiency of a system made of a polymer resin sorbent beads column (CST 401, Cytosorbents) and this particular catheter was tested in the MOCS running a solution composed of 0.9% saline and radio-contrast. During two series of 18 cycles of first-pass experiments we assessed the catheter's suctioning efficiency and the system's ability to clear radio-contrast injected into the MOCS's cerebral arterial segment. We also assessed the functioning and reliability of the MOCS. Results: Mean suctioning efficiency of the catheter was 84% ± 24%. The polymer sorbent column contrast removal rate was initially 96% and gradually decreased with subsequent cycles in a linear fashion during an experiment lasting approximately 90 minutes. The MOCS had a reliability of 0.9946×min{sup −1} where 1 × min{sup −1} was the optimum value. Conclusion: A system including a polymer resin sorbent beads column and a custom-made suctioning catheter had an excellent initial efficiency in quickly removing contrast from an artificial MOCS mimicking the cerebral circulation. MOCS is an inexpensive and relatively reliable custom-made system that can be used for training or testing purposes.

  19. Gfr estimation using 99mTc DTPA gates method for assessment of early diabetic nephropathy - a comparison with 24-hour creatinine clearance

    To correlate Gates glomerular filtration rate (GGFR) using technetium-99m diethylene triaminepentacetic acid (99mTc DTPA) with 24-hour creatinine clearance (CRCL) and to establish relationship with duration of diabetes in patients with early diabetic nephropathy. Study Design: A cross-sectional comparative study carried out in Nuclear Medical Centre from Aug 2009 to Jan 2010 at Armed Forces Institute of Pathology (AFIP), Rawalpindi, Pakistan. Patients and Methods: A total of eighty three subjects were enrolled, who were divided into three groups; group 1 comprised 31 normotensive diabetics, group 2 had 37 hypertensive diabetics while group 3 had 15 normal subjects. The DTPA GFR and creatinine clearance in healthy subjects as well as diabetic patients were compared using the unpaired student's t-test. The linear association between GFR, creatinine clearance and disease duration was expressed by Pearson's correlation coefficient 'r' along with their significance levels. Results: Gates GFR showed hyperfiltration in normotensive diabetics (96.6 +- 3.3 ml/min/1.73 m/sub 2/), significantly (p<0.05) higher than controls (85.5 +- 5 ml/min/1.73 m/sub 2/), whereas hypertensive diabetics had a significantly lower (p<0.05) Gates GFR (76.8 +- 3.7) than that of controls. Significant degree of correlation existed between GGFR and CRCL in hypertensive diabetics (p<0.05, r=0.716) and controls (r=0.546). Gates GFR also showed good correlation with duration of diabetes in both diabetic groups as compared to that of CRCL. GGFR also correlated well with duration of hypertension 0.37 (0.31-0.43) as compared to CRCL 0.155 (0.15-0.16) in all groups. Conclusions: The 99mTc-DTPA clearance correlates significantly with 24-hour creatinine clearance as well as with disease duration and can provide a simple and convenient index of kidney function in patients of early diabetic nephropathy. (author)

  20. Re-entry flight clearance

    Juliana, S.

    2006-01-01

    The objective of the research was to identify and evaluate promising mathematical techniques for re-entry flight clearance. To fulfil this objective, two mathematical methods were investigated and developed: μ analysis for linear models and interval analysis for both linear and non-linear models. The stability of re-entry vehicles in the presence of model uncertainties was chosen as the clearance criterion, which is represented by two mathematical criteria: worst-case eigenvalues (linear...

  1. A combined study of Xe-133 clearance method and plethysmography for the estimate of shunt flow in the limb of the diabetic patients

    Disturbance of limb circulation is one of the major sign in the diabetic patients. Estimation of non-nutrient blood flow, ''Steal phenomenon'', in the legs of diabetic patients is useful for decision of therapy and prevention of diabetic gangrene. In this communication, the Xe-133 clearance method and the admittance plethysmography were simultaneously performed to estimate the non-nutrient shunt flow in the normal subjects and in the diabetic patients. From the Xe-133 clearance curve, blood flow rates in the muscle (Fm) and in the skin (Fs) were separately measured. When the volume percent of the calf tissues was expressed as 70% for the muscle and 10% for the skin, the relationship between the total blood flow (Fy) measured by the admittance plethysmography and the nutrient flow in the muscle and skin (Fn = 0.7Fm - 0.1Fs) was Fy = 1.09Fn + 0.05(ml/min/100g tissue). The sum of the blood flow in the bone and the non-nutrient shunt flow was about 11% of total blood flow in the calf. This value augmented by the peripheral heating, suggesting an increase of shunt flow. In the diabetic patients, the non-nutrient shunt flow increased associated with a reduction of the total flow in the calf. A combined study of the Xe-133 clearance method and the plethysmography is useful to estimate the non-nutrient flow in the pathologic condition of lower extremities

  2. Reliability of two different methods, whole body measurement and shoulder probe measurement, as judged from determinations of the renal clearance of orthoiodine hippuric acid

    This retrospective study was based on 1300 patients subjected to a series of radiopharmaceutical renal function studies, during which parallel determinations of the renal clearance rate were carried out using whole body measurements and shoulder probe measurements. It was the aim of this analysis to assess the reliability of shoulder probe measurements as compared to that of whole body measurements as well as their suitability for the diagnosis of postural perfusion disorders associated with nephroptosis and to define the generally acceptable normal ranges of the clearance of ortho-iodine hippuric acid on the basis of age and sex groups. As long as the values measured remained within normal limits, no major differences were discernable between the two methods. In reduced renal function, however, the shoulder probe measurements were biassed in a consistent way and tended to an overestimation of the renal performance that was proportionate to the degree of insufficiency. The intra-assay variations observed for the two methods did not differ from each other at a statistically significant level. The systematic error seen in connection with the shoulder probe measurements can in fact be easily eliminated. This method also offers the advantage of greater simplicity and can be carried out with the patient being in an upright position. Its suitability for the detection of postural perfusion disorders still remains to be proven in further studies. The results of the study are of clinical relevance inasfar as it was possible to determine lower limits of OJH clearance for the individual age and sex groups. (orig.)

  3. Validation of the flow-through chamber (FTC) and steady-state (SS) methods for clearance rate measurements in bivalves

    Larsen, Poul Scheel; Riisgård, Hans Ulrik

    2012-01-01

    a uniform chamber concentration prevailing at its incurrent flow and at the chamber outlet. These prerequisites can be checked by a plot of CR versus increasing Fl, which should give the true CR at all through-flows. Theoretically, the experimental uncertainty of CR for a given accuracy of...... can be checked by a plot of clearance rate (CR) versus increasing through-flow (Fl) to reach a plateau, which is the true CR, but we also recommend to plot percent particles cleared versus reciprocal through-flow where the plateau becomes the straight line CR/Fl, and we emphasize that the percent of...... be employed in e.g. long-term growth experiments at constant algal concentrations....

  4. Role of mucus in gastric mucosal injury induced by local ischemia/reperfusion.

    Seno, K; Joh, T; Yokoyama, Y; Itoh, M

    1995-09-01

    The role of gastric mucus was evaluated in a rat model of gastric epithelial damage induced by local ischemia/reperfusion (I/R) stress. In this model, blood-to-lumen chromium 51-labeled ethylenediaminetetraacetic acid (51Cr-EDTA) clearance served as an index of injury. Tetraprenyl acetone (TPA; 100 mg, 200 mg/kg IP) was used to stimulate mucus production. Administration of TPA increased both the hexosamine content in gastric tissue and the amount of alcian blue-periodic acid Schiff (AB-PAS) stained mucus in the mucosa in a dose-dependent manner. Increases in 51Cr-EDTA clearance induced by I/R were significantly attenuated by TPA in a dose-dependent manner. N-acetyl-L-cysteine (NAC; 0.6%, 0.8%) was perfused into the gastric lumen to assess the effect of reduction in mucus on the injury induced by I/R. Although mean values of hexosamine content were increased by perfusion with NAC, AB-PAS-stained mucus in the mucosa was significantly decreased in a dose-dependent manner. Perfusion of NAC did not change basal 51Cr-EDTA clearance but significantly exacerbated the increase in clearance induced by I/R in a dose-dependent manner. These results indicate that gastric mucus protects the gastric mucosa against I/R stress in vivo. PMID:7665977

  5. Skeletal muscle oxygen pressure fields in artificially ventilated, critically ill patients

    The MDO (Mehrdraht Dostmund Oberflaeche) oxygen electrode was used in a study of skeletal muscle oxygen pressure fields, presented as histograms, in critically ill patients artificially ventilated with gas mixtures of different oxygen concentrations. The histograms were compared with forearm blood flow measurements performed with strain gauge plethysmography. Local blood flow and permeability-surface area product (PS) were also studied by the simultaneous clearances of 133xenon and 51Cr-EDTA. The histogram distribution type was normal, i.e. approximately Gaussian, at arterial oxygen pressure levels between 10 and 18 kPa. At arterial oxygen pressures outside this range the histogram distribution types were abnormal, i.e. they showed a non-symmetrical distribution of oxygen pressure values, but their mean was approximately the same as in the normal histogram. However, there were significantly higher tissue oxygen pressure mean values in the patients (3.43 kPa) than in a group of healthy human volunteers (2.25 kPa). Mean forearm blood flow and the clearances of 133xenon and 51Cr-EDTA showed marked variations during the measurements both intraindividually and interindividually. Mean forearm blood flow and mean clearances of 133xenon showed opposite trends compared with arterial oxygen pressures. Mean clearances of 51Cr-EDTA and mean PS showed minor variations at the different arterial oxygen pressure levels. (author)

  6. Calculation of the renal clearance by dynamic measurement of the excreted activity

    Aim: In this paper we present a new method to measure the renal slope-clearance of Tc-99m-MAG-3 in a single-shot model (Excretion-clearance). Method: A renal scintigraphy with Tc-99m-MAG-3 was performed in 22 patients. The excreted activity of the tracer in the kidneys and the bladder was dynamically measured using a double-head gamma-camera. Additionally, the total absorption over the kidneys and the bladder was determined. The Excretion-clearance was calculated in a differential and an integral variant. Simultaneously the 2-compartment-clearance (Sapirstein-clearance), the Oberhausen-clearance and the Bubeck-clearance were calculated. Results: The Sapirstein-clearance is considered as the 'goldstandard' in a single-shot modell. The correlation of the Bubeck-clearance and the Oberhausen-clearance ranged from r=0.96 to r=0.97, the Excretion-clearance (differential-method) correlated with r=0.90. The absolute difference of the clearance-values was lowest comparing the Bubeck-clearance with the Sapirstein-clearance with an average difference of 11%, whereas the Excretion-clearance revealed at least an average difference of 21% and the Oberhausen-clearance of 24%. Discussion: The Excretion-clearance requires a more complicated protocoll measuring the clearance in comparison to the Bubeck-clearance. The results of the excretion-clearance differ more from the Sapirstein-clearance with regard to the examined patient population than the Bubeck-clearance. Regarding the theoretical basis of the methods, we expect advantages of the Excretion-clearance compared with the Bubeck-clearance in patients with compartmental disproportion or with a low clearance. We are going to prove this in combination with the above mentioned methodical improvements in a further study. (orig.)

  7. In vitro-in vivo extrapolation of quantitative hepatic biotransformation data for fish - I. A review of methods, and strategies for incorporating intrinsic clearance estimates into chemical kinetic models

    Nichols, John W.; Schultz, Irv R.; Fitzsimmons, Patrick N..

    2006-06-10

    Mammalian researchers have developed a stepwise approach to predict in vivo hepatic clearance from measurements of in vitro hepatic metabolism. The resulting clearance estimates have been used to screen drug candidates, identify potential drug-drug interactions, investigate idiosyncratic drug responses, and support toxicology risk assessments. In this report we review these methods, discuss their potential application to studies with fish, and describe how extrapolated values could be incorporated into well-known compartmental kinetic models. Empirical equations that relate extrapolation factors to chemical log Kow are given to facilitate the incorporation of metabolism data into bioconcentration and bioaccumulation models. Because they explicitly incorporate the concept of clearance, compartmental clearance volume models are particularly well suited for incorporating hepatic clearance estimates. The manner in which these clearance values are incorporated into a given model depends, however, on the measurement frame of reference. Procedures for the incorporation of in vitro metabolism data into physiologically based toxicokinetic (PBTK) models are also described. Unlike most compartmental models, PBTK models are developed to describe the effects of metabolism in the tissue where it occurs. In addition, PBTK models are well suited to modeling metabolism in more than one tissue.

  8. Renal clearance of melatonin

    Editorial Office

    1996-01-01

    Only two publications exist in which actual values for the renal clearance of intact melatonin in man is described. The melatonin clearance values were, however, obtained either after the oral intake of melatonin, or by applying different techniques for the determination of melatonin in urine and plasma. In this study, renal clearance of melatonin was determined during the hours where melatonin concentrations are relatively constant. Melatonin levels in plasma and urine respectively were e...

  9. Application of measuring 99mTc-MAG3 plasma clearance based on one-compartment model (MPC method) to renal transplantation

    Measurement of 99mTc-MAG3 plasma clearance (CLmag) based on one-compartment model (MPC method) was applied to renal transplantation and evaluated for the factors which might affect the calculated results, especially concerning renal depth. Correlation coefficient of CLmag between MPC method using real renal depth and Russell or Bubeck single sampling method was good (r=0.852 or 0.876, respectively). Regression equation between MPC method and Russell method was y=1.044x-3.0 and was more closer to y=x than that between MPC method and Bubeck method. CLmag of MPC method calculated by estimated renal depth from the abdominal thickness was also similar to that by real renal depth. Even if the fixed renal depth, 4 cm, was applied, the coefficient and regression equation between MPC method and Russell method were r=0.884 and y=1.004x-10.2. In conclusion, MPC method is applicable to the evaluation of renal transplants. Though measuring renal depth is best, calculation with fixed renal depth of 4 cm might be practically acceptable. (author)

  10. Security Clearance Tracking System

    National Archives and Records Administration — SCTS supports the adjudication process of private background investigations and clearances for potential employees, contractors, interns and student workers.

  11. Comparative animal studies for the determination of the extracellular space with several radioactively labelled substances

    The volume of the total extracellular space and of the extracellular space of the organs (liver, lungs, heart, spleen, brain) was determined with the aid of 5 radioactively labelled substances, each in 10 rats. The test substances (inulin-3H, 51Cr-EDTA, thiosulfate-35S, NH4-82Br, 60Co-vitamin B12) are described in the relevant literature as substances for the determination of the extracellular space and as clearance substances. (BSC/AK)

  12. Methods of precisely estimating the jacket pressure coefficient of controlled-clearance piston-cylinders at pressures up to 1 GPa

    Kajikawa, Hiroaki; Ide, Kazunori; Kobata, Tokihiko

    2011-10-01

    Deformational characteristics of a controlled-clearance piston-cylinder (CCPC) have been evaluated to precisely estimate the pressure dependence of its effective area. Among the experimentally accessible characteristics, the jacket pressure coefficient d, which denotes the relative change in the effective area due to applied jacket pressure pj, is examined in this paper. Two methods for precisely determining d at pressures up to 1 GPa are proposed. One is a comparative method that uses a set of a pressure balance and a multiplier as the tare gauge. The other is a new method that uses precise pressure transducers as monitoring devices. Both pj and weights loaded on the CCPC are changed so that the pressure generated by the CCPC remains constant, which is monitored by the transducers. d is estimated by the relative change in the weights loaded on the CCPC itself. Using the two methods, d for a 1 MPa kg-1 CCPC is measured at pressures up to 1 GPa. At each system pressure, d obtained by each method is approximated by a linear function of pj. The consistency of the fit values of d by the two methods is confirmed. The method using pressure transducers as monitoring devices is advantageous in terms of efficiency and operability especially at higher pressures.

  13. Turbomachinery Clearance Control

    Chupp, Raymond E.; Hendricks, Robert C.; Lattime, Scott B.; Steinetz, Bruce M.; Aksit, Mahmut F.

    2007-01-01

    Controlling interface clearances is the most cost effective method of enhancing turbomachinery performance. Seals control turbomachinery leakages, coolant flows and contribute to overall system rotordynamic stability. In many instances, sealing interfaces and coatings are sacrificial, like lubricants, giving up their integrity for the benefit of the component. They are subjected to abrasion, erosion, oxidation, incursive rubs, foreign object damage (FOD) and deposits as well as extremes in thermal, mechanical, aerodynamic and impact loadings. Tribological pairing of materials control how well and how long these interfaces will be effective in controlling flow. A variety of seal types and materials are required to satisfy turbomachinery sealing demands. These seals must be properly designed to maintain the interface clearances. In some cases, this will mean machining adjacent surfaces, yet in many other applications, coatings are employed for optimum performance. Many seals are coating composites fabricated on superstructures or substrates that are coated with sacrificial materials which can be refurbished either in situ or by removal, stripping, recoating and replacing until substrate life is exceeded. For blade and knife tip sealing an important class of materials known as abradables permit blade or knife rubbing without significant damage or wear to the rotating element while maintaining an effective sealing interface. Most such tip interfaces are passive, yet some, as for the high-pressure turbine (HPT) case or shroud, are actively controlled. This work presents an overview of turbomachinery sealing. Areas covered include: characteristics of gas and steam turbine sealing applications and environments, benefits of sealing, types of standard static and dynamics seals, advanced seal designs, as well as life and limitations issues.

  14. Wear analysis of revolute joints with clearance in multibody systems

    Bai, ZhengFeng; Zhao, Yang; Wang, XingGui

    2013-08-01

    In this work, the prediction of wear for revolute joint with clearance in multibody systems is investigated using a computational methodology. The contact model in clearance joint is established using a new hybrid nonlinear contact force model and the friction effect is considered by using a modified Coulomb friction model. The dynamics model of multibody system with clearance is established using dynamic segmentation modeling method and the computational process for wear analysis of clearance joint in multibody systems is presented. The main computational process for wear analysis of clearance joint includes two steps, which are dynamics analysis and wear analysis. The dynamics simulation of multibody system with revolute clearance joint is carried out and the contact forces are drawn and used to calculate the wear amount of revolute clearance joint based on the Archard's wear model. Finally, a four-bar multibody mechanical system with revolute clearance joint is used as numerical example application to perform the simulation and show the dynamics responses and wear characteristics of multibody systems with revolute clearance joint. The main results of this work indicate that the contact between the joint elements is wider and more frequent in some specific regions and the wear phenomenon is not regular around the joint surface, which causes the clearance size increase non-regularly after clearance joint wear. This work presents an effective method to predict wear of revolute joint with clearance in multibody systems.

  15. Comparative evaluation of iohexol and inulin clearance for glomerular filtration rate determinations

    The authors have evaluated iohexol as a filtration marker in 150 children. The clearance of iohexol was compared with that of inulin or with a formula clearance. The single-sample clearance of iohexol showed a good correlation with the clearance of inulin. The clearance of iohexol correlated well with the formula clearance. The optimal blood sampling time for iohexol clearance determinations appears to be between 120 and 180 min after injection, at least in patient with relatively normal filtration rates. It is concluded that iohexol clearance is an accurate method of determining the glomerular filtration rate in clinical practice. 25 refs., 5 figs

  16. Noninvasive clearance of airway secretions.

    Hardy, K A; Anderson, B D

    1996-06-01

    or airway malacia. Use of positive pressure to maintain airway patency in these children allows cephalad clearance of secretions. Patients with segmental atelectasis, particularly related to asthma, may benefit from intrapulmonary percussive ventilator, positive expiratory pressure, or PDPV. Prevention of postoperative atelectasis is particularly well suited to positive expiratory pressure, which is not as painful as techniques using oscillations. Neurologically abnormal patients who are unable to cooperate with any active method are also treated using intrapulmonary percussive ventilator, PDPV, and suctioning, if necessary. Musculoskeletal abnormalities, muscular dystrophies, myasthenia gravis, poliomyelitis, or other similar diseases require stabilization of bellows function. Optimizing ventilation in patients with such abnormalities may require positive pressure ventilation either during sleep or continuously. Externally applied pressure, such as with the In-Exsufflator or the cyclically inflated pneumatic belt, can augment the patient's own efforts and is sometimes helpful. Normalizing the vital capacity and functional residual capacity typically helps to improve the ability to cough and clear secretions. Assisted cough devices or maneuvers are described in other papers by Bach and Hill. Not all patients who have weak muscles require nocturnal or continuous support, and may benefit from positive expiratory pressure mask treatments. Further studies are sorely needed for this population. Long-term controlled trials are urgently needed to help establish the best types of treatment for patients with CF and bronchiectasis. Such studies will become more complicated by the introduction of new treatments, such as DNase and other therapies that alter secretions, and may begin to change mucociliary or cough clearance. The selection of appropriate outcome measures is central to studying these questions, and it is unclear which are the most important. (ABSTRACT TRUNCATED

  17. Renal Clearance of Nanoparticles

    Choi, Hak Soo; Liu, Wenhao; Misra, Preeti; Tanaka, Eiichi; Zimmer, John P.; Ipe, Binil Itty; Bawendi, Moungi G.; Frangioni, John V.

    2007-01-01

    The field of nanotechnology holds great promise for the diagnosis and treatment of human disease. However, the size and charge of most nanoparticles preclude their efficient clearance from the body as intact nanoparticles. Without such clearance or their biodegradation into biologically benign components, toxicity is potentially amplified and radiological imaging is hindered. Using quantum dots (QDs) as a model system, we have precisely defined the requirements for renal filtration and urinar...

  18. Optimisation-based clearance

    Varga, Andras

    2002-01-01

    The basic feature of the optimisation-based clearance approach is to reformulate the clearance problems as equivalent minimum distance problems for which ”anti”-optimisation is performed to determine the worst-case parameter combination/ flight condition leading to worst performance. The basic requirements for the applicability of the optimisation-based approach are the availability of suitable parametric models describing the overall nonlinear dynamics of the augmented aircraft and of accomp...

  19. Antiepidermal growth factor variant III scFv fragment: effect of radioiodination method on tumor targeting and normal tissue clearance

    Shankar, Sriram [Department of Radiology, Duke University Medical Center, Durham, NC 27710 (United States); Vaidyanathan, Ganesan [Department of Radiology, Duke University Medical Center, Durham, NC 27710 (United States); Kuan, C.-T. [Department of Pathology, Duke University Medical Center, Durham, NC 27710 (United States); Bigner, Darell D. [Department of Pathology, Duke University Medical Center, Durham, NC 27710 (United States); Zalutsky, Michael R. [Department of Radiology, Duke University Medical Center, Durham, NC 27710 (United States) and Department of Pathology, Duke University Medical Center, Durham, NC 27710 (United States) and Department of Biomedical Engineering, Duke University, Durham, NC 27708 (United States)]. E-mail: zalut001@duke.edu

    2006-01-15

    Introduction: MR1-1 is a single-chain Fv (scFv) fragment that binds with high affinity to epidermal growth factor receptor variant III, which is overexpressed on gliomas and other tumors but is not present on normal tissues. The objective of this study was to evaluate four different methods for labeling MR1-1 scFv that had been previously investigated for the radioiodinating of an intact anti-epidermal growth factor receptor variant III (anti-EGFRvIII) monoclonal antibody (mAb) L8A4. Methods: The MR1-1 scFv was labeled with {sup 125}I/{sup 131}I using the Iodogen method, and was also radiohalogenated with acylation agents bearing substituents that were positively charged-N-succinimidyl-3-[*I]iodo-5-pyridine carboxylate and N-succinimidyl-4-guanidinomethyl-3-[*I]iodobenzoate ([*I]SGMIB)-and negatively charged-N-succinimidyl-3-[*I]iodo-4-phosphonomethylbenzoate ([*I]SIPMB). In vitro internalization assays were performed with the U87MG{delta}EGFR cell line, and the tissue distribution of the radioiodinated scFv fragments was evaluated in athymic mice bearing subcutaneous U87MG{delta}EGFR xenografts. Results and Conclusion: As seen previously with the anti-EGFRvIII IgG mAb, retention of radioiodine activity in U87MG{delta}EGFR cells in the internalization assay was labeling method dependent, with SGMIB and SIPMB yielding the most prolonged retention. However, unlike the case with the intact mAb, the results of the internalization assays were not predictive of in vivo tumor localization capacity of the labeled scFv. Renal activity was dependent on the nature of the labeling method. With MR1-1 labeled using SIPMB, kidney uptake was highest and most prolonged; catabolism studies indicated that this uptake primarily was in the form of {epsilon}-N-3-[*I]iodo-4-phosphonomethylbenzoyl lysine.

  20. Generic Clearance Values

    This paper analyzes the Generic Clearance Values established for natural and artificial radionuclides with the objective of evaluating their degree of conservatism in views of adopting them into the regulatory body. Generic clearance values for natural radionuclides have been chosen by experts judgments as the optimum boundary between, on the one hand, the ubiquitous unmodified soil concentrations and, on the other hand, activity concentrations in ores, mineral sands, industrial residues and wastes. For artificial radionuclides the clearance levels have been derived from the scenarios postulated in the document Safety Reports Series 44 of the IAEA considering quantitative exemption criteria. A set of 8 scenarios were postulated covering external, ingestion and inhalation exposure pathways. For each radionuclide, the generic clearance level was derived as the more restrictive value obtained from the scenarios, that is the lowest ratio between the applicable individual dose and the dose per unit activity concentration (Bq/g). The individual dose was calculated by a formula depending on each scenario and pathway, with different parameters, such as exposure time, dosimetric factors, dilution factor, density of the material, geometric factors, etc. It was concluded that the basis and parameters used for the derivation of the generic clearance levels are quite conservative and therefore its the adoption in Argentina has been recommended. It is expected that their implementation will contribute to optimize the regulatory management system. (authors)

  1. Generic clearance values

    This paper analyzes the Generic Clearance Values established for natural and artificial radionuclides with the objective of evaluating their degree of conservatism in views of adopting them into the regulatory body. Generic clearance values for natural radionuclides have been chosen by experts judgments as the optimum boundary between, on one hand, the ubiquitous unmodified soil concentrations and, on the other hand, activity concentrations in ores, mineral sands, industrial residues and wastes. For artificial radionuclides the clearance levels have been derived from the scenarios postulated in the document 'Safety Reports Series Nr 44' of the IAEA considering quantitative exemption criteria. A set of 8 scenarios were postulated covering external, ingestion and inhalation exposure pathways. For each radionuclide, the generic clearance level was derived as the more restrictive value obtained from the scenarios, that is the lowest ratio between the applicable individual dose and the dose per unit activity concentration (Bq/g). The individual dose was calculated by a formula depending on each scenario and pathway, with different parameters, such as exposure time, dosimetric factors, dilution factor, density of the material, geometric factors, etc. It was concluded that the basis and parameters used for the derivation of the generic clearance levels are quite conservative and therefore its the adoption in Argentina has been recommended. It is expected that their implementation will contribute to optimize the regulatory management system. (author)

  2. Gamma-scintigraphy as a novel method to study the distribution and clearance rate of different muco adhesive nasal delivery systems

    Nasal route has a high potential for drug delivery. One important limiting factor for nasal drug delivery is the rapid clearance of drugs from the nasal cavity. Several nasal drug delivery systems including different kinds of microspheres and liposomes have been tried for encapsulation of drugs and increasing the residence time in nasal cavity. In this study clearance rate of three kinds of microspheres (Alginate, PLGA and Dextran) and four kinds of liposomes (neutral, cationic, fusogenic and cationic-fusogenic) was determined. Lactose powder was used as negative control. Technetium pertechnetate labeling and gamma scintigraphy was used for precise and quantitative measurement of clearance rate of these delivery system. 99mTc labeled microspheres and liposomes were prepared using technetium pertechnetate in the presence of a potent reducing agent, st annus chloride. The labeling procedure was set in a manner that each 150 micro litter of liposome suspensions and each 3-5 mg of microspheres contained 2 MBq of radioactivity. Labeling efficiency was calculated by paper chromatography using acetone as mobile phase. Each delivery system containing 2 MBq of activity was sprayed into right nostril of four healthy volunteers and immediately after spraying, anterior view of nasal cavity was measured by a large field gamma camera equipped with a low-energy high resolution parallel collimator. One minute static views were repeated each half hour until 4 hours. Clearance rates were compared using two ROI; the initial site of deposition of sprays, and all of nasal cavity to nasopharynx. Clearance rate of each one of microspheres and liposomes was calculated after applying the physical decay corrections. The labeling efficiency for liposomes and microspheres calculated as 41.2% and 60.7% respectively. The cleared percent of delivery systems after 4 hours was determined as follows: neutral liposomes 18.7±3.9% cationic liposomes 43.7±2.1%; fusogenic liposomes 32.8±2

  3. Mucociliary clearance in chronic sinusitis

    Birdi, Surinder Mohan; Singh, Sunder; Singh, Ajit

    1998-01-01

    Mucociliary clearance is an important defence mechanism of upper and lower respiratory tracts. Any disturbance in the mechanism leads to stagnation of secretions and secondary infection with prolonged mucociliary clearance time. The present study was undertaken to establish normal mucociliary clearance time in our region and to evaluate its diagnostic and prognostic potential in chronic sinusitis of variable duration with and without obstructive diseases.

  4. Segmental tubular sodium reabsorption in type 1 diabetes

    Dieperink, H; Eshøj, O; Leyssac, P P;

    1993-01-01

    Segmental tubular sodium reabsorption in Type 1 (insulin-dependent) diabetes was measured in 36 patients in a cross-sectional study including one group (n = 13) without significant albuminuria (UalbV < 30 mg 24 h-1), one group (n = 16) with albuminuria in the range from 30 to 300 mg 24 h-1, and a...... group (n = 7) with nephropathy (UalbV > 300 mg 24 h-1). Lithium clearance was used to measure end proximal delivery. From end proximal delivery, 51Cr-EDTA clearance (GFR) and sodium clearance, segmental tubular reabsorption was calculated. For all patients, GFR was directly correlated with end proximal...

  5. Phagocytic Clearance in Neurodegeneration

    Sokolowski, Jennifer D.; Mandell, James W.

    2011-01-01

    The cellular and molecular mechanisms of phagocytic clearance of apoptotic cells and debris have been intensely studied in invertebrate model organisms and in the mammalian immune system. This evolutionarily conserved process serves multiple purposes. Uncleared debris from dying cells or aggregated proteins can be toxic and may trigger exaggerated inflammatory responses. Even though apoptotic cell death and debris accumulation are key features of neurodegenerative diseases, relatively little ...

  6. Modelling mucociliary clearance

    Smith, D.J.; Gaffney, E.A.; Blake, J R

    2008-01-01

    Mathematical modelling of the fluid mechanics of mucociliary clearance (MCC) is reviewed and future challenges for researchers are discussed. The morphology of the bronchial and tracheal airway surface liquid (ASL) and ciliated epithelium are briefly introduced. The cilia beat cycle, beat frequency and metachronal coordination are described, along with the rheology of the mucous layer. Theoretical modelling of MCC from the late 1960s onwards is reviewed, and distinctions between ‘phenomenolog...

  7. Comparison of quantitative autoradiographic and xenon-133 clearance methods: correlation of gray and white matter cerebral blood flow with compartmental blood flow indices

    The relationships between CBF in gray and white matter to those of the fast and slow components of xenon-133 clearance curves remain uncertain. CBF was measured in 13 anaesthetized baboons under a variety of conditions, using both the xenon-133 clearance technique and [14C]iodoantipyrine quantitative autoradiography. There was a linear relationship between CBF, as determined by the stochastic (height/area) analysis of the clearance curve, and mean CBF determined from the autoradiograms (r = 0.94, p less than 0.001, slope = 0.86 +/- 0.09). There was also a linear correlation between the fast-flow component (measured with xenon-133) and blood flow in the cerebral gray matter (measured with [14C]iodoantipyrine) (r = 0.92, p less than 0.001, slope = 0.69 +/- 0.15) and between the slow-flow component (with xenon-133) and blood flow in white matter (with [14C]iodoantipyrine) (r = 0.79, p less than 0.01, slope = 0.81 +/- 0.10). In the primate brain, the fast- and slow-flow indices therefore appear to be representative of CBF in gray matter and white matter, respectively, whereas the stochastic analysis provides a stable measure of mean CBF within the tissue monitored

  8. Comparison of quantitative autoradiographic and xenon-133 clearance methods: correlation of gray and white matter cerebral blood flow with compartmental blood flow indices

    Tuor, U.I.; Fitch, W.; Graham, D.I.; Mendelow, A.D.

    1986-08-01

    The relationships between CBF in gray and white matter to those of the fast and slow components of xenon-133 clearance curves remain uncertain. CBF was measured in 13 anaesthetized baboons under a variety of conditions, using both the xenon-133 clearance technique and (14C)iodoantipyrine quantitative autoradiography. There was a linear relationship between CBF, as determined by the stochastic (height/area) analysis of the clearance curve, and mean CBF determined from the autoradiograms (r = 0.94, p less than 0.001, slope = 0.86 +/- 0.09). There was also a linear correlation between the fast-flow component (measured with xenon-133) and blood flow in the cerebral gray matter (measured with (14C)iodoantipyrine) (r = 0.92, p less than 0.001, slope = 0.69 +/- 0.15) and between the slow-flow component (with xenon-133) and blood flow in white matter (with (14C)iodoantipyrine) (r = 0.79, p less than 0.01, slope = 0.81 +/- 0.10). In the primate brain, the fast- and slow-flow indices therefore appear to be representative of CBF in gray matter and white matter, respectively, whereas the stochastic analysis provides a stable measure of mean CBF within the tissue monitored.

  9. Cystatin C or Creatinine for Detection of Stage 3 Chronic Kidney Disease in Anorexia Nervosa.

    Delanaye, Pierre; Cavalier, Etienne; RADERMECKER, Régis; Paquot, Nicolas; Depas, Gisèle; Chapelle, Jean-Paul; Scheen, André; Krzesinski, Jean-Marie

    2008-01-01

    Background: Patients with anorexia nervosa (AN) are at a high risk of renal failure. Chronic kidney disease (CKD) is often missed in these patients because the serum creatinine is a poor marker of kidney function. We studied the utility of cystatin C to detect renal failure in this population. Method: Twenty-seven AN patients were studied. Glomerular filtration rates (GFR) were measured with the chromium-51- ethylenediaminetetraacetate ((51)Cr-EDTA) method. We compared the ability of creatini...

  10. Experimental inflammation following dural application of complete Freund's adjuvant or inflammatory soup does not alter brain and trigeminal microvascular passage

    Lundblad, Cornelia; Haanes, Kristian A; Grände, Gustaf;

    2015-01-01

    migraine for many patients, their site of action remains unidentified. It has been suggested that during migraine attacks the leakiness of the blood-brain barrier (BBB) is altered, increasing the passage of anti-migraine drugs. This study aimed to investigate the effect of experimental inflammation......, following dural application of complete Freund's adjuvant (CFA) or inflammatory soup (IS) on brain and trigeminal microvascular passage. METHODS: In order to address this issue, we induced local inflammation in male Sprague-Dawley-rats dura mater by the addition of CFA or IS directly on the dural surface....... Following 2, 24 or 48 h of inflammation we calculated permeability-surface area product (PS) for [(51)Cr]-EDTA in the trigeminal ganglion (TG), spinal trigeminal nucleus, cortex, periaqueductal grey and cerebellum. RESULTS: We observed that [(51)Cr]-EDTA did not pass into the central nervous system (CNS) in...

  11. Glomerular filtration rate by 51chomium and 113mindium labeled EDTA in horses

    The glomerular filtration rate was determined in nine healthy horses, six male and three female, aged two to 12-year-old, by means of 51Cr and 113mIn labeled EDTA single injection technique. The glomerular filtration rate was calculated from the plasma disappearance curve and the volume of distribution of the radiotracer, 51Cr-EDTA or 113mIn-EDTA. The result (mean +- standard deviation) was 148.80 +- 26.42 m L.min-1.100 kg. It is concluded that the measurement of glomerular filtration rate by 51Cr-EDTA or 113mIn-EDTA by single injection technique eliminates the bladder catheterization, and for its simplicity, convenience, accuracy, and low dose of radiation, can be used in horses as a method of choice in clinical routine. (author)

  12. Glomerular filtration rate by {sup 51}chomium and {sup 113m}indium labeled EDTA in horses; Taxa de filtracao glomerular pelo EDTA marcado com {sup 51}cromo e com {sup 113m}indio em equinos

    Maliska, C.; D' Almeida, J.; Pellegrini, P.M.; Schimit, T.S. [Hospital Central do Exercito (HCE), Rio de Janeiro, RJ (Brazil). Servico de Medicina Nuclear; Pinho, W.R. [Centro de Ensino Superior, Valenca, RJ (Brazil). Fac. de Medicina Veterinaria; Lima, J.E.T. [Instituto Nacional do Cancer (INCa), Rio de Janeiro, RJ (Brazil). Servico de Medicina Nuclear

    2009-07-01

    The glomerular filtration rate was determined in nine healthy horses, six male and three female, aged two to 12-year-old, by means of {sup 51}Cr and {sup 113m}In labeled EDTA single injection technique. The glomerular filtration rate was calculated from the plasma disappearance curve and the volume of distribution of the radiotracer, {sup 51}Cr-EDTA or {sup 113m}In-EDTA. The result (mean +- standard deviation) was 148.80 +- 26.42 m L.min{sup -1}.100 kg. It is concluded that the measurement of glomerular filtration rate by {sup 51}Cr-EDTA or {sup 113m}In-EDTA by single injection technique eliminates the bladder catheterization, and for its simplicity, convenience, accuracy, and low dose of radiation, can be used in horses as a method of choice in clinical routine. (author)

  13. Site clearance working group

    NONE

    1997-03-01

    The Gulf of Mexico and Louisiana continue to be areas with a high level of facility removal, and the pace of removal is projected to increase. Regulations were promulgated for the Gulf of Mexico and Louisiana requiring that abandoned sites be cleared of debris that could interfere with fishing and shrimping activities. The site clearance regulations also required verification that the sites were clear. Additionally, government programs were established to compensate fishermen for losses associated with snagging their equipment on oil and gas related objects that remained on the water bottoms in areas other than active producing sites and sites that had been verified as clear of obstructions and snags. The oil and gas industry funds the compensation programs. This paper reviews the regulations and evolving operating practices in the Gulf of Mexico and Louisiana where site clearance and fisherman`s gear compensation regulations have been in place for a number of years. Although regulations and guidelines may be in place elsewhere in the world, this paper focuses on the Gulf of Mexico and Louisiana. Workshop participants are encouraged to bring up international issues during the course of the workshop. Additionally, this paper raises questions and focuses on issues that are of concern to the various Gulf of Mexico and Louisiana water surface and water bottom stakeholders. This paper does not have answers to the questions or issues. During the workshop participants will debate the questions and issues in an attempt to develop consensus opinions and/or make suggestions that can be provided to the appropriate organizations, both private and government, for possible future research or policy adjustments. Site clearance and facility removal are different activities. Facility removal deals with removal of the structures used to produce oil and gas including platforms, wells, casing, piles, pipelines, well protection structures, etc.

  14. Family study of antipyrine clearance.

    Blain, P G; Mucklow, J C; Wood, P; Roberts, D F; Rawlins, M D

    1982-01-01

    Antipyrine clearance was measured in 208 healthy volunteers from 78 families. After the values had been corrected for weight and sex, antipyrine clearance was observed to be significantly correlated between siblings (r = 0.590) and between spouses (r = 0.320), but not between parents and their offspring. After the clearance values had been corrected for tobacco and oral contraceptive use, there was still no significant correlation between parents and offspring. These results are incompatible ...

  15. An accredited infrastructure for clearance of decommissioning waste

    The nuclear research reactors and a hot-cell facility at the Riso site in Denmark have been closed and are in the process of being decommissioned. This has prompted the development of an accredited infrastructure called the Clearance Function. This function is responsible for the activity concentration measurements of the clearance candidates and for the demonstration of compliance with the clearance levels for the released objects. The Clearance Function comprises laboratory facilities, measuring equipment, measuring procedures, waste handling software, software for clearance related calculations and trained personnel. An accreditation of the Clearance Function has been granted from the accreditation body, DANAK, according to the international standard ISO/IEC 17025:2005. DANAK is a member of ILAC, the International Laboratory Accreditation Cooperation. The Clearance Function has been accredited to measure surface-specific and mass-specific activities using surface contamination monitors and high purity germanium detectors. The germanium detectors are characterised and in each measurement they are calibrated using the ISOCS (registered) calibration software. Activity concentration measurements can be made on items as a whole (one or several combined measurements) or on samples from an item. In the latter case a statistical method is used to evaluate whether the activity concentration is above or below the clearance level. The paper describes the different elements of the Clearance Function and the processing of items through the flow routes depending on the likely activity content and the distribution of activity. It is shown how uncertainties are incorporated in the clearance criteria. Experience from the first year of operation of the Clearance Function is reported. (author)

  16. An accredited infrastructure for clearance of decommissioning waste

    The nuclear research reactors and a hot-cell facility at the Riso site in Denmark have been closed and are in the process of being decommissioned. This has prompted the development of an accredited infrastructure called the Clearance Function. This function is responsible for the activity concentration measurements of the clearance candidates and for the demonstration of compliance with the clearance levels for the released objects. The Clearance Function comprises laboratory facilities, measuring equipment, measuring procedures, waste handling software, software for clearance related calculations and trained personnel. An accreditation of the Clearance Function has been granted from the accreditation body, DANAK, according to the international standard ISO/IEC 17025:2005. DANAK is a member of ILAC, the International Laboratory Accreditation Cooperation. The Clearance Function has been accredited to measure surface-specific and mass-specific activities using surface contamination monitors and high purity germanium detectors. The germanium detectors are characterised and in each measurement they are calibrated using the ISOCS calibration software. Activity concentration measurements can be made on items as a whole (one or several combined measurements) or on samples from an item. In the latter case a statistical method is used to evaluate whether the activity concentration is above or below the clearance level. The paper describes the different elements of the Clearance Function and the processing of items through the flow routes depending on the likely activity content and the distribution of activity. It is shown how uncertainties are incorporated in the clearance criteria. Experience from the first year of operation of the Clearance Function is reported. (author)

  17. Study to improve the precision of calculation of split renal clearance by gamma camera method using 99mTc-MAG3

    Both fundamental and clinical studies were performed to improve the precision with which split renal clearance is calculated from the relation between renal clearance and the total renal uptake rate by using 99mTc-MAG3, which is mainly excreted into the proximal renal tubules. In the fundamental study, the most suitable kidney phantom threshold values for the extracted renal outline were investigated with regard to size, radioactivity, depth of the kidney phantom, and radioactivity in the background. In the clinical study, suitable timing to obtain additional images for making the ROI and the standard point for calculation of renal uptake rate were investigated. The results indicated that, although suitable threshold values were distributed from 25% to 45%, differences in size, solution activity, and the position of the phantom or BG activity did not have significant effects. Comparing 1-3 min with 2-5 min as the time for additional images for ROI, we found that renal areas using the former time showed higher values, and the correlation coefficient of the regression formula improved significantly. Comparison of the timing for the start of data acquisition with the end of the arterial phase as a standard point of calculating renal uptake rate showed improvement in the latter. (author)

  18. Reforming Customs Clearance in Pakistan

    Ahmad, Manzoor

    2010-01-01

    Simple, fast, transparent customs clearance procedures encourage trade-and the resulting tariffs and related taxes raise government revenue and stimulate economic development. After outsourcing failed to make customs more efficient or increase revenue, in 2002 Pakistan began pursuing a modern single window system for customs clearance. In 2005 the system was introduced at the port of Karac...

  19. RATIONAL CUSTOMS CLEARANCE TECHNOLOGY CHOICE

    Shramenko, N.; Andriets, V.

    2008-01-01

    Issues concerning cargo delivery efficiencyincrease by choice of rational customs clearance technology have been considered. Three possible variants of customs clearance andmethods which allow to define the most rational version of cargo delivery in international road communication based on main efficiency criteria for definite distance have been presented.

  20. Analysis of conservativity analysis for clearance levels. Final report

    When deriving clearance levels for material from nuclear installations it is necessary to proceed with a certain degree of conservativity. This can, however, differ between various sets of clearance levels leading to inconsistencies between clearance pathways. The aim of the work therefore is to compare levels of conservativity for the following two sets of clearance levels: clearance levels for disposal as conventional waste and for metallic materials for recycling/reuse. A method was developed to quantify the degree of conservativity and make it comparable. The actual and future situation for disposal of (conventional) wastes in Germany was analysed. In addition, the masses, nuclide vectors, geographical distribution etc. for slightly radioactive material being cleared for conventional disposal was analysed and modelled and the resulting dose distributions were calculated. The values for the clearance levels were taken from the 1995 recommendation by the German Commission on Radiation Protection (SSK). By using realistic scenarios, the exposure was calculated for the personnel on the landfills and for persons of the general public being exposed via groundwater pathways. It could be shown that the trivial dose range will not be exceeded even if the masses of cleared material per landfill site exceed 100 Mg/a. Because of the types and distribution of nuclear installations in Germany and because of the nuclide vectors it is therefore not necessary to limit the masses per landfill sites. Clearance levels that are determined by the exposure pathways external exposure to and the inhalation of dust by the landfill personnel show a similar level of conservativity as those for metal scrap. This means that the clearance levels for gamma emitting nuclides are not overly restrictive. Although radiologically justified, raising the clearance levels would not lead to an increase of the material quantities because other nuclides of the respective nuclide vectors are limiting. In

  1. Antipyrene clearance in Indian villagers.

    Desai, N K; Sheth, U K; Mucklow, J C; Fraser, H S; Bulpitt, C J; Jones, S.W.; Dollery, C. T.

    1980-01-01

    1 Antipyrine clearance has been measured using saliva samples in 50 Maharashtrans from a village to the north of Bombay. 2 All subjects were very lean and were also anaemic probably as a result of hookworm infestation. 3 Antipyrine clearance was 36% faster than in White Londoners studied previously and more than twice as fast as in Asian immigrants living in London. 4 Clearance was 25% faster in men than in women but volume of distribution was also greater in men and mean half-lives did not d...

  2. Clearance of von Willebrand factor. : Clearance of von Willebrand factor

    Denis, Cécile; Christophe, Olivier; Oortwijn, Beatrijs,; Lenting, Peter,

    2008-01-01

    The life cycle of von Willebrand factor (VWF) comprises a number of distinct steps, ranging from the controlled expression of the VWF gene in endothelial cells and megakaryocytes to the removal of VWF from the circulation. The various aspects of VWF clearance have been the objects of intense research in the last few years, stimulated by observations that VWF clearance is a relatively common component of the pathogenesis of type 1 von Willebrand disease (VWD). Moreover, improving the survival ...

  3. Improved survival and renal prognosis of patients with type 2 diabetes and nephropathy with improved control of risk factors

    Andrésdóttir, Gudbjörg; Jensen, Majken; Carstensen, Bendix;

    2014-01-01

    become standard of care. RESEARCH DESIGN AND METHODS: All patients with type 2 diabetes and DN (n = 543) at the Steno Diabetes Center were followed during 2000-2010. GFR was measured yearly with 51Cr-EDTA plasma clearance. Annual decline in GFR was determined in patients with at least three measurements...... over a minimum of 3 years (∆GFR cohort, n = 286). Results were compared with historical data, obtained using identical criteria at our hospital, before implementation of current treatment guidelines. RESULTS: Baseline mean (SD) GFR was 74 (32) mL/min/1.73 m2. More than 93% received RAS inhibition...... onset of DN in the ∆GFR cohort was compared with that of our prior ∆GFR cohort from 1983 to 2003 (n = 227). Crude mortality risk was reduced by 42% and after age adjustment by 50% (P < 0.001 for both). In a multistate model accounting for competing risks of ESRD and death, prior cardiovascular disease...

  4. GFR prediction from cystatin C and creatinine in children: body cell mass increases accuracy of the estimate

    Andersen, Trine Borup; Jødal, Lars; Bøgsted, Martin;

    ) aged 2-14 years (mean 8.8 years). GFR was 14-147 mL/min/1.73m2 (mean 97 mL/min/1.73m2). BCM was estimated using bioimpedance spectroscopy (Xitron Hydra 4200). Log-transformed data on BCM/CysC, serum creatinine (SCr), body-surface-area (BSA), height x BSA/SCr, serum CysC, weight, sex, age, height, serum......AIM: To derive an accurate prediction model for estimating glomerular filtration rate (GFR) in children based primarily on the endogenous renal function marker cystatin C (CysC) and body cell mass (BCM). THEORY: Cystatin C is produced at a constant rate in all cells of the body and is excreted by...... glomerular filtration followed by catabolization in the tubular cells. We hypothesized that production rate is proportional to body cell mass (BCM) and inferred GFR (mL/min) to be proportional to BCM/CysC. MATERIAL AND METHODS: GFR was determined with 51Cr-EDTA-clearance in 131 children (52 girls, 79 boys...

  5. Detecting reduced renal function in children

    Andersen, Trine Borup; Jødal, Lars; Erlandsen, Erland J;

    2013-01-01

    using two cut-off levels, dividing renal function into normal or reduced, with an intermediate "gray zone" of indeterminable results.Methods Glomerular filtration rate was measured by plasma clearance of 51Cr-EDTA (13.7–147.4 mL/min/1.73 m2) in 119 children (age range 2.3–14.9 years).Reduced renal...... function was defined as a GFR of<82 mL/min/1.73 m2. SCr, SCysC, age-normalized creatinine (SCr-ratio), and eight published GFR-models were compared for their ability to correctly classify renal function as normal or reduced. Cut-off levels were determined so as to give 99 % certainty outside the gray zone.......Results The multivariable GFR-models by Schwartz et al. (J Am Soc Nephrol 2009; 20:629–637) and Zappitelli et al. (Am J Kidney Dis 2006; 48:221–230) and two models by Andersen et al. [Am J Kidney Dis 2012; 59(1):50–57: body cell mass (BCM)-model and Weight-model] performed significantly better than all other...

  6. Prediction of renal function (GFR) from cystatin C and creatinine in children: Body cell mass increases accuracy of the estimate

    Andersen, Trine Borup; Jødal, Lars; Bøgsted, Martin;

    ) aged 2-14 years (mean 8.8 years). GFR was 14-147 mL/min/1.73m2 (mean 97 mL/min/1.73m2). BCM was estimated using bioimpedance spectroscopy (Xitron Hydra 4200). Log-transformed data on BCM/CysC, serum creatinine (SCr), body-surface-area (BSA), height x BSA/SCr, serum CysC, weight, sex, age, height, serum......AIM: To derive an accurate prediction model for estimating glomerular filtration rate (GFR) in children based primarily on the endogenous renal function marker cystatin C (CysC) and body cell mass (BCM). THEORY: Cystatin C is produced at a constant rate in all cells of the body and is excreted by...... glomerular filtration followed by catabolization in the tubular cells. We hypothesized that production rate is proportional to body cell mass (BCM) and inferred GFR (mL/min) to be proportional to BCM/CysC. MATERIAL AND METHODS: GFR was determined with 51Cr-EDTA-clearance in 131 children (52 girls, 79 boys...

  7. Large kidneys predict poor renal outcome in subjects with diabetes and chronic kidney disease

    Vendrely Benoit

    2010-03-01

    Full Text Available Abstract Background Renal hypertrophy occurs early in diabetic nephropathy, its later value is unknown. Do large kidneys still predict poor outcome in patients with diabetes and Chronic Kidney Disease (CKD? Methods Seventy-five patients with diabetes and CKD according to a Glomerular Filtration Rate (GFR, by 51Cr-EDTA clearance below 60 mL/min/1.73 m2 or an Albumin Excretion Rate above 30 mg/24 H, had an ultrasound imaging of the kidneys and were cooperatively followed during five years by the Diabetology and Nephrology departments of the Centre Hospitalier Universitaire de Bordeaux. Results The patients were mainly men (44/75, aged 62 ± 13 yrs, with long-standing diabetes (duration:17 ± 9 yrs, 55/75 type 2, and CKD: initial GFR: 56.5 (8.5-209 mL/min/1.73 m2, AER: 196 (20-2358 mg/24 H. Their mean kidney lenght (108 ± 13 mm, 67-147 was correlated to the GFR (r = 0.23, p Conclusions Large kidneys still predict progression in advanced CKD complicating diabetes. In these patients, ultrasound imaging not only excludes obstructive renal disease, but also provides information on the progression of the renal disease.

  8. Renal function analysis by CT. CT clearance versus [sup 131]I-Hippuran clearance. Eine Nierenfunktionsanalyse durch die Computertomographie. CT-Clearance versus [sup 131]Jod-Hippuran-Clearance

    Kaltenborn, H.; Klose, K. (Johannes-Gutenberg-Universitaet Mainz, Radiologische Klinik (Germany))

    1992-06-01

    The CT clearance in a number of urological patients (39 patients, 25 with normal renal function) was studied by means of an ''area under curve'' (AUC) method, using a region of interest. 31 patients were given meglumine ioxithalamate and 8 patients Iopamidol as a contrast medium. Both for total and partial function there was highly significant correlation with isotope clearance with good reproducibility. The difference in the pharmacokinetics of the contrast media affected the absolute clearance values. (orig.).

  9. Lithium clearance in chronic nephropathy

    Kamper, A L; Holstein-Rathlou, N H; Leyssac, P P;

    1989-01-01

    1. Lithium clearance measurements were made in 72 patients with chronic nephropathy of different aetiology and moderate to severely reduced renal function. 2. Lithium clearance was strictly correlated with glomerular filtration rate, and there was no suggestion of distal tubular reabsorption of...... clearance data were independent of whether renal disease was of primarily glomerular or tubular origin and, further, were not influenced by long-term conventional antihypertensive treatment. 6. It is concluded that, even with a reduced kidney function, the data are compatible with the suggestion that...... lithium clearance may be a measure of the delivery of sodium and water from the renal proximal tubule. With this assumption it was found that adjustment of the sodium excretion in chronic nephropathy initially takes place in the distal parts of the nephron (loop of Henle, distal tubule and collecting duct...

  10. Measurement of nasal mucociliary clearance.

    Corbo, G M; Foresi, A; Bonfitto, P; Mugnano, A; Agabiti, N.; Cole, P J

    1989-01-01

    The saccharin test was carried out in a randomly selected sample of schoolchildren (142 boys and 153 girls, age range 11-14 years) to determine the variability and reproducibility of the test and to assess whether it could be used as a screening test for nasal mucociliary clearance. Nasal mucociliary clearance times were analysed according to clinical history (asthma, rhinitis, asthma with rhinitis, and acute upper respiratory tract infections), laboratory findings (positive skin test respons...

  11. Inherited Disorders of Bilirubin Clearance

    Memon, Naureen; Weinberger, Barry I; Hegyi, Thomas; Aleksunes, Lauren M

    2015-01-01

    Inherited disorders of hyperbilirubinemia may be caused by increased bilirubin production or decreased bilirubin clearance. Reduced hepatic bilirubin clearance can be due to defective 1) unconjugated bilirubin uptake and intrahepatic storage, 2) conjugation of glucuronic acid to bilirubin (e.g. Gilbert syndrome, Crigler-Najjar syndrome, Lucey-Driscoll syndrome, breast milk jaundice), 3) bilirubin excretion into bile (Dubin-Johnson syndrome), or 4) conjugated bilirubin re-uptake (Rotor syndrom...

  12. Distribution and clearance of radioactive aerosol on the nasal mucosa.

    McLean, J A; Bacon, J R; Mathews, K P; Thrall, J H; Banas, J M; Hedden, J; Bayne, N K

    1984-03-01

    The distribution and clearance of aerosolized radioactive technetium 99m pertechnate in physiologic buffered saline was analyzed in four human adult asymptomatic volunteers following delivery into one nostril in the same manner as for nasal challenge testing (i.e., 0.1 ml via a 251 DeVilbiss atomizer powered by a compressor delivering 0.10 +/- 0.01 gm/spray). For comparison, squeeze bottles and spray bottles from commercial sources, a 114 and a 127 DeVilbiss atomizer, and a pipette were employed. Lateral imagery via minicomputer processing was used to determine both distribution and clearance of the radiotracer. The counts after 1 minute were lower following pipette delivery than with the other devices. None yielded discernable , wide-spread distribution of aerosol throughout the nasal cavity. Following delivery from the 251 atomizer, mean clearance at 17 minutes was 60.0%. Similar clearance rates were obtained with the other spraying methods except for lower values with the squeeze bottle. Analysis of six hour clearance studies by linear regression showed a relatively rapid initial phase, which is probably due largely to mucociliary clearance, and a prolonged late phase related to the very slow disappearance of residual material located far anteriorly in the nose. Achieving good initial retention and rapid clearance of material deposited anteriorly in the nose are desirable attributes of devices employed for administering materials intranasally. PMID:6328631

  13. Comparison of renal clearance of 99mTc-DTPA and inulin 131I-hippurate and PAH as well as creatinine clearance in Wistar-rats

    Averages and standard deviations of 99mTc-DTPA and 131I-hippurate slope clearance were consecutively determined for 56 male Wistar rats, with a body-weight of 271 ± 69 g in a single investigation. Clearance of 99mTc-DTPA was 17.4 ± 3.4, that of 131I-hippurate was 34.3 ± 7.2 μl · s-1 per 100 g body weight. For 17 rats inulin and PAH clearances were determined after 3 days with the steady-state method with continuous infusion and 3-4 periods of urine collection. During the same periods endogeneous creatinine clearance was determined. 99mTc-DTPA slope clearance correlated well with inulin clearance, also the hippurate with the PAH clearance. The high values of the filtration fraction, calculated from radioisotope and chemical methods, and the low PAH extraction of 42% lead to the conclusion, that PAH and hippurate are incompletely eliminated by the rat kidney from plasma and therefore are inadequate for determining renal blood flow in rats. Creatinine clearance was 4.7 ± 1.38 μl · s-1 per 100 g body weight, much lower than that of inulin and 99mTc-DTPA. Therefore is assumed, that tubular reabsorption of creatinine occurs and creatinine clearance cannot serve for the evaluation of GFR in rats. For this, however, the clearance of 99mTc-DTPA seems well applicable in Wistar rats. (author)

  14. Nasal mucociliary clearance in coal mine workers

    Cinar, F.; Beder, L. [Karaelmas University, Kozlu Zonguldak (Turkey)

    2004-06-01

    The purpose of this study was to analyze the effect of coal dust particles on nasal mucociliary function in coal mine workers. Using the saccharin method, nasal mucociliary clearance was determined for 77 subjects, of which 39 who worked in a coal mine were actively exposed to coal dust whereas 38 were unexposed control subjects. The measurements were performed in the coal mine, at the level of 170 m below sea level. The average saccharin nasal transit time in coal mine workers, 12.61 (SD: 4.30) minutes, is longer, than that of the control subjects, 10.97 (SD: 3.22). Although the findings of this study demonstrate that the coal particles affect the nasal mucociliary clearance, the difference in saccharin nasal transit time between the two groups (exposed vs unexposed) is not statistically significant (P = 0.063).

  15. Comparison of renal clearance of 99mTc-DTPA and inulin, 131I-hippurate and PAH as well as of the creatinine clearance in Wistar rats

    Order of magnitude and standard deviation of 99mTc-DTPA and 131I-hippurate slope clearance were analyzed successively in 56 male Wistar rats. The clearance of 99mTc-DTPA was 17.4 ± 3.43 μl · s-1 (100 g b-w)-1, of 131I-hippurate 34.3 ± 7.21 μl · s-1 (100 g b-w)-1. In 17 rats inulin and PAH clearances were analyzed by steady state method with permanent infusion and 3 to 4 urine collection periods 3 days later. The endogeneous creatinine clearance was determined within the same periods. The 99mTc-DTPA slope clearance corresponded to the inulin clearance, as well as the hippurate clearance to the PAH clearance. The high filtration fraction calculated from nuclear medicine and chemical clearance methods and the low PAH extraction (42%) let suggest that PAH and hippurate are eliminated only incompletely from plasma in rat kidney and are unsuitable for determination of renal blood supply in rats. The creatinine clearance with 4.7 ± 1.38 μl · s-1 (100 g b-w)-1 was far beneath the clearance of inulin and 99mTc-DTPA, supposing that creatinine is reabsorbed tubularly in part and the creatinine clearance can not be used for valuation of the GFR in rats. However, for this the 99mTc-DTPA clearance in Wistar rats seems to be well suited. (author)

  16. SKIN KINETICS AND DERMAL CLEARANCE

    Prakash Shashi

    2012-08-01

    Full Text Available Availability of several therapeutic and cosmetic formulations for topical application has made the research on skin kinetics as a topic of current interest. Topical formulations are typically meant for local effect although there is always a chance that the low molecular weight chemicals are easily transported across the skin layer and make it available in the systemic circulation. Thus there is a major concern about the transport of chemical moieties following the topical application of cosmetics and therapeutic formulations and the real time measurement of the molecules in the skin layer has become obligatory. It is well known that the properties of both drug and the excipients have identical role in determining the skin permeability of chemical moieties. In the last decade several investigations have been carried out in this filed using several in vitro and in vivo models. This review provides a brief account on the basics of skin kinetics, parameters assessed, various techniques and methods adapted in skin kinetic studies. Moreover, we have also discussed about the micro-environment inside the skin layer and the possible mechanism of drug depot formation, skin metabolism and clearance of molecules from the skin layers.

  17. The renal handling of sodium and water is not affected by the standard-dose cisplatin treatment for testicular cancer

    Daugaard, G; Strandgaard, S; Holstein-Rathlou, N H;

    1987-01-01

    Renal clearances of 51Cr-EDTA, lithium, sodium and potassium were measured before and after each of four consecutive treatment series with cisplatin in 15 men with testicular cancer. Since lithium is reabsorbed like sodium and water in the proximal tubules, but not reabsorbed to any measurable...... all other parameters of glomerular filtration and renal sodium handling remained normal throughout the study (with the exception of a fall in fractional sodium excretion after the first treatment series). Plasma magnesium declined during all four treatment periods, signifying renal magnesium wasting....

  18. Pathogenesis and treatment of diabetic glomerulopathy

    Diabetic glomerulopathy is the consequence, at the glomerular level, of diabetes. Diagnosis is based on the association of proteinuria, arterial hypertension and an early reduction of glomerular filtration in a diabetic patient, generally insulin-dependent. Diabetic glomerulopathy is a complication of type I diabetes, which begins in childhood or adolescence, but can also be discovered in type II diabetes. A definite diagnosis requires histological evidences ; glomerular clearance measurements (125I-iodothalamate or 51Cr-EDTA) yield important information concerning glomerular filtration. The authors subsequently address pathogenesis and therapeutic regimens, and they report on the particularities of this condition in type II diabetes. (authors). 30 refs., 2 tabs

  19. [Bromsulphalein clearance in persons in occupational contact with pesticides].

    Mechkov, G; Petkova, V; Zakhariev, N

    1987-01-01

    In 46 persons (sprayers, disinfectors, technicians of the agricultural aviation) the bromsulphalein clearance is traced, during the active work season with pesticides, after the method of Caroly, Nys and Alliot. It is established, that the mean value of bromsulphalein clearance (8.91%) is lower than that of the referent group healthy persons (14.5%). In 14 (31.34%) of the examined the values of the clearance are under 10%. The changes of the last do not correlate closely to other indices of the liver function. As an explanation of the results the authors presuppose general pathogenetic relations between the metabolism of pesticides and of bromsulphalein in the liver cell, with inclusion of glutathione-S-transferase systems. The study allows to give a practical conclusion for the meaning of the bromsulphalein clearance and assessment of the pesticides effect in persons who are in professional contact with them. PMID:3441475

  20. Lithium clearance in chronic nephropathy

    Kamper, A L; Holstein-Rathlou, N H; Leyssac, P P;

    1989-01-01

    1. Lithium clearance measurements were made in 72 patients with chronic nephropathy of different aetiology and moderate to severely reduced renal function. 2. Lithium clearance was strictly correlated with glomerular filtration rate, and there was no suggestion of distal tubular reabsorption of...... lithium or influence of osmotic diuresis. 3. Fractional reabsorption of lithium was reduced in most patients with glomerular filtration rates below 25 ml/min. 4. Calculated fractional distal reabsorption of sodium was reduced in most patients with glomerular filtration rates below 50 ml/min. 5. Lithium...... lithium clearance may be a measure of the delivery of sodium and water from the renal proximal tubule. With this assumption it was found that adjustment of the sodium excretion in chronic nephropathy initially takes place in the distal parts of the nephron (loop of Henle, distal tubule and collecting duct...

  1. Lactate clearance in cardiorespiratory emergency

    Serena Greco

    2007-08-01

    Full Text Available Early goal directed therapy has been found to improve prognosis in septic patients, if the therapeutic goal is achieved within the first six hours. The aim of our study is to demonstrate that in patients with acute cardiorespiratory failure, rapid (within 2 hours lactate clearance can help define patients’ prognosis. 67 consecutive patients, admitted to our 16-bed Emergency Medicine ward for acute cardiorespiratory failure (age 75,9 ± 9,8 (APACHE II score 19,0 ± 4,1, were included in the study. Blood lactate concentration was read at admission and after 2, 6 and 24 hours. We evaluated mortality at seven days and the use of orotracheal intubation (patients with negative outcome vs. discharge or transfer to a non-emergency ward with subsequent discharge (patients with negative outcome. Lactate concentration at admission was 4,6 ± 2,5 mmol/l; lactate clearance (% at 2 hours was 40,4 ± 32,1 in patients with a positive outcome and –8,3 ± 5,0 in patients with a negative outcome (p < 0,05. Lactate clearance at 2 hours < 25% is correlated to a negative outcome with an 84,2% sensitivity and a 79,2% specificity. The positive predictive value was 61,5% and the negative predictive value was 92,2%. Systematic lactate clearance monitoring can be used in cases of acute cardiorespiratory insufficiency to identify patients with a high risk of negative outcome. In our study, low clearance at two hours was associated with an increase in mortality and/or the need for orotracheal intubation. Conversely, a clearance at two hours of > 25% in most cases confirms the therapeutic strategy undertaken. Serial evaluation of blood lactate concentration may therefore be useful in guiding treatment strategies.

  2. Inherited Disorders of Bilirubin Clearance

    Memon, Naureen; Weinberger, Barry I; Hegyi, Thomas; Aleksunes, Lauren M

    2016-01-01

    Inherited disorders of hyperbilirubinemia may be caused by increased bilirubin production or decreased bilirubin clearance. Reduced hepatic bilirubin clearance can be due to defective 1) unconjugated bilirubin uptake and intrahepatic storage, 2) conjugation of glucuronic acid to bilirubin (e.g. Gilbert syndrome, Crigler-Najjar syndrome, Lucey-Driscoll syndrome, breast milk jaundice), 3) bilirubin excretion into bile (Dubin-Johnson syndrome), or 4) conjugated bilirubin re-uptake (Rotor syndrome). In this review, the molecular mechanisms and clinical manifestations of these conditions are described, as well as current approaches to diagnosis and therapy. PMID:26595536

  3. Application of clearance automatic laser inspection system to clearance measurement of concrete waste

    Recently, the Clearance Automatic Laser Inspection System (CLALIS) has been developed for the clearance measurement of metal scraps. It utilizes three-dimensional (3D) laser scanning, y-ray measurement and Monte Carlo calculation, and has outstanding detection ability. For the clearance measurement of concrete segments, the effect of background (BG) gamma rays from natural radionuclides in the measurement target, such as K-40 and the radioactive decay products of Th-232 and U-238, should be compensated for to ensure adequate waste management. Since NE102A plastic scintillation detectors are used for y-ray measurement in CLALIS, it is impossible to distinguish between count rates of natural radionuclides and contaminants on the basis of gamma-ray energy information. To apply CLALIS to the clearance measurement of concrete segments, the original activity evaluation method was improved by adding a new compensation procedure. In this procedure, BG count rate due to natural radionuclides is estimated by a Monte Carlo calculation with pre-analyzed data of a representative sample of the measurement target. The activity concentration of natural radionuclides in concrete differs markedly depending on the production location of its components, such as cement and aggregates. In this study, using six mock concrete waste samples, which were composed of cement and fine aggregate from various production locations, the accuracy of BG compensation was experimentally estimated. In addition, the accuracy of calibration for concrete waste was also estimated using a number of mock concrete segments of small and large triangular prisms. By considering the uncertainties of BG compensation and calibration, the detection limit of CLALIS for concrete waste was estimated. As a result, it was revealed that CLALIS could be applied to the clearance measurement of concrete segments when the mass of the measurement target is greater than approximately 1.1 kg and the key radionuclide is Co-60

  4. The optimal clearance design of micro-punching die

    K.S. Lee

    2008-07-01

    Full Text Available Purpose: The purpose of this research paper is focused on the optimal clearance design of micro-punching die by abductive network and SA method.Design/methodology/approach: The punching data (input and wear size (output were collected for a training database. In order to select proper clearance to evaluate the wear of die, the abductive network was used to establish an efficient relationship between input parameters and output result. This can help to predict wear size under any degree of clearance and hence to replace worn punches and dies at the right time. A simulated annealing (SA optimization algorithm with a performance index is then applied to the neural network for searching the optimal clearance parameters, and obtains rather satisfactory result as compared with the corresponding experiment verification.Findings: This study aims to identify the relationship between clearance and service life of micro punches using the Neural Network, and to find relational data involving the service life of punches and punching parameters in non-metal blanking processes. The result can be used to estimate optimal clearance between punch and die for industrial applications.Research limitations/implications: In this study, the practical punching processes with different punching conditions were carried out for a set of training data. A trained model exhibited a relationship between service life and clearance of micro punch and die through an abductive network system. The predicted value of wear by abductive network is very close to the actual experimental value, with an error of less than 8%. This result satisfies the required standard for IC factory production.Originality/value: A good clearance design not only increases the quality of product manufactured, but also reduces product’s burr. As a result, the wear of punches and dies can be greatly reduced and the life expectancy of punching dies increased.

  5. Experimental study on fluid flow in arciform clearance

    邵俊鹏; 汤卉; 贾慧娟

    2002-01-01

    The system damping and dynamic characteristics can be further improved by properly increasing thedamping coefficient ξh. For a special hydraulic damping structure, an arciform damping clearance often used inFCS, a mathematical model has been established for fluid flow using the theory of laminar flow in the clearanceof parallel plates. Analytical calculations are made for fluid flow in the arciform clearance and relational expres-sion is deduced for flow rate along the arciform cleaance height, pressure difference, maximum arciform clear-ance height, the flow rate for the fluid flow in arciform clearance as well, and its simplified formula is obtainedby using the theory of hydrodynamics and the curve - fitting method. This paper consists of two sections: the firstsection focuses on the theoretical analysis by using the simplified mathematical model and the second sectionmainly describes experimental analysis. The simplified formula is corrected with experimental results by consid-erig various boundary conditions of the damping clearance. Experimental results show that this study of arciformdamping clearance is reliable and practical.

  6. Determination of glomerular filtration rate from plasma clearance with Tc99m.DTPA by single; two and multi-sample methods

    Background.The plasma sample method following a single injection of radioactive markers has been proved to be simple and accurate for the determination of glomerular filtration rate (GFR) in clinical practice. The aim of this study was to assess clinical accuracy of single-, two-and multi-sample methods. Patients and Methods. The study was performed on 50 patients with various degrees of renal dysfunction (29 males and 21 females; aged 27-90 years). As a reference the true GFR was determined by means of the two compartment model curve fitting 10 plasma following a single-injection of Tc99m-DTPA. The GFR was estimated by the three methods of single-, two and multi-sample between 75 and 300 min after the injection. The GFR by two and multi-sample methods was determined with the slope and intercept algorithm and its overestimation was corrected by Brochner-Mortensen's formula. Results. In all patients with a GFR between 12 and 169 ml/min/1.73m2, accuracy for the determination of GFR was identical in both the single-and five-sample methods. In 46 patients with a GFR higher than 30 ml/min/1.73m2, the single-sample method exhibited the lowest standard error of mean of difference in GFR. In 38 patients with a GFR lower than 120 ml/min/1.732, the two and five sample methods were more accurate than the single-sample one. The best combination of sampling time for the two samples was 120 min and 240 min after the injection. Conclusion. Accuracy of each plasma sample method depends on the preserved GFR. As a matter of practice, the single-sample method is the first choice for a patient who is expected to have a GFR higher than 30 ml/min/1.73m2. The two-sample method is indicated only in a patient with severe renal failure with a GFE lower than 30 ml/min/1.73m2 (au)

  7. 49 CFR 192.325 - Underground clearance.

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Underground clearance. 192.325 Section 192.325... Lines and Mains § 192.325 Underground clearance. (a) Each transmission line must be installed with at least 12 inches (305 millimeters) of clearance from any other underground structure not associated...

  8. 32 CFR 154.48 - Issuing clearance.

    2010-07-01

    ... 32 National Defense 1 2010-07-01 2010-07-01 false Issuing clearance. 154.48 Section 154.48 National Defense Department of Defense OFFICE OF THE SECRETARY OF DEFENSE SECURITY DEPARTMENT OF DEFENSE PERSONNEL SECURITY PROGRAM REGULATION Issuing Clearance and Granting Access § 154.48 Issuing clearance. (a) Authorities designated in paragraph...

  9. 30 CFR 56.11010 - Stairstep clearance.

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Stairstep clearance. 56.11010 Section 56.11010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Travelways § 56.11010 Stairstep clearance. Vertical clearance...

  10. 14 CFR 25.925 - Propeller clearance.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller clearance. 25.925 Section 25.925 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.925 Propeller clearance. Unless smaller clearances are substantiated,...

  11. Vest Chest Physiotherapy Airway Clearance is Associated with Nitric Oxide Metabolism

    Sisson, Joseph H.; Wyatt, Todd A.; Pavlik, Jacqueline A.; Pawanjit S. Sarna; Murphy, Peter J

    2013-01-01

    Background. Vest chest physiotherapy (VCPT) enhances airway clearance in cystic fibrosis (CF) by an unknown mechanism. Because cilia are sensitive to nitric oxide (NO), we hypothesized that VCPT enhances clearance by changing NO metabolism. Methods. Both normal subjects and stable CF subjects had pre- and post-VCPT airway clearance assessed using nasal saccharin transit time (NSTT) followed by a collection of exhaled breath condensate (EBC) analyzed for NO metabolites (NO x ). Results. VCPT s...

  12. 76 FR 47917 - Lead; Clearance and Clearance Testing Requirements for the Renovation, Repair, and Painting Program

    2011-08-05

    ... August 5, 2011 Part IV Environmental Protection Agency 40 CFR Part 745 Lead; Clearance and Clearance... AGENCY 40 CFR Part 745 RIN 2070-AJ57 Lead; Clearance and Clearance Testing Requirements for the... 2008 Lead Renovation, Repair, and Painting Program (RRP) rule, the EPA agreed to propose a number...

  13. Measurement of single kidney contrast media clearance by multiphasic spiral computed tomography: preliminary results

    Objective. We present preliminary results of a new method (hereinafter called 'CT-clearance') to measure single kidney contrast media clearance by performing multiphasic helical CT of the kidneys. CT-clearance was calculated according to an extension of the Patlak-Plot. In contrast to prior investigators, who repeatedly measured a single slice, this method makes it possible to calculate single kidney clearance from at least three spiral CTs, utilizing the whole kidney volume. Methods. Spiral CT of the kidneys was performed unenhanced and about 30 and 100 s after administration of about 120 ml iopromide. Sum-density of the whole kidneys and aortic density was calculated from this data. Using this data, renal clearance of contrast media was calculated by CT-clearance in 29 patients. As reference, Serum-clearance was calculated in 24 patients by application of a modified one-exponential slope model. Information on the relative kidney function was gained by renal scintigraphy with Tc99m-MAG-3 or Tc99m-DMSA in 29 patients. Results. Linear regression analysis revealed a correlation coefficient of CT-clearance with Serum-clearance of r=0.78 with Cl (CT) [ml/min]=22.2+1.03 * Cl (serum), n=24. Linear regression of the relative kidney function (rkf) of the right kidney calculated by CT-clearance compared to scintigraphy results provided a correlation coefficient r=0.89 with rkf(CT)[%]=18.6+0.58 * rkf(scintigraphy), n=29. Conclusion. The obtained results of contrast media clearance measured by CT-clearance are in the physiological range of the parameter. Future studies should be performed to improve the methodology with the aim of higher accuracy. More specifically, better determination of the aortic density curve might improve the accuracy

  14. Impaired tracheobronchial clearance in bronchiectasis.

    Currie, D C; Pavia, D; Agnew, J E; Lopez-Vidriero, M T; Diamond, P D; Cole, P J; Clarke, S. W.

    1987-01-01

    Tracheobronchial clearance was measured by a radioaerosol technique in 12 patients with bronchiectasis, seven patients with chronic obstructive lung disease expectorating mucoid sputum daily (group X), eight patients with chronic obstructive lung disease but negligible sputum expectoration (group Y), and 10 healthy subjects. The patients with bronchiectasis all expectorated purulent sputum daily (mean wet weight 47 g/day), had reduced forced expiratory volume in one second (FEV1) (mean 47.5% ...

  15. Age-dependence and intersubject variability of tracheobronchial particle clearance

    Robert Sturm

    2011-01-01

    Full Text Available SUMMARY.Background: The detailed study of tracheobronchial clearanceof inhaled particles represents one of the basic research questionsin lung medicine. The clearance efficiency varies in different agegroups and between males and females.The differences can bepartly clarified by the application of a well validated theoreticalapproach. This study applied a relevant model to children (1 year,5 years, 10 years, juveniles (15 years, and adults of different ages(18, 21, 25, 34, 50, and 60 years and to both sexes. Methods: Themathematical model used for clearance simulation is based on theconcept of a stochastic lung structure and considers both early fastmucociliary clearance and a later, slow clearance fraction, fs, effectedby particular uptake by tracheobronchial cells, e.g., macrophagesand epithelial cells. According to this model, the calculated mucusvelocities for each airway generation of the tracheobronchial compartmentare normalized to a respective tracheal mucus velocitythat is estimated for each of the age groups studied from an allometricfunction. Results: In general, tracheobronchial clearanceefficiency undergoes a significant increase from childhood to youngadulthood, reaching a maximum at 25-30 years and decreasingagain from about 30 years to 60 years. Conversely to the improvementof clearance, the continuous change of airway morphometrywith increasing age causes a decrease of the filtering effect in thetrachea and main bronchi, which is of marked importance in infants.The modelling results demonstrate differences in tracheobronchialclearance between males and females, generally in the range from0 to 5%, which are exclusively determined by the individual lunggeometry. Conclusions: Based on theoretical computations itcan be concluded that tracheobronchial clearance is a phenomenonthat depends on both age and sex. Biological studies are necessaryto determine the cellular and molecular mechanisms underlyingthe age-dependent development of

  16. Periodic response of multi-disk rotors with bearing clearances

    Kim, Y. B.; Noah, S. T.; Choi, Y. S.

    1991-02-01

    The forced steady state response of a multi-disk rotor system involving a clearance at one of the bearings is determined by using a harmonic balance approach. The impedance method is applied to each of the harmonic steady state components in order to reduce the system to its displacement at the non-linear bearing support. The results reveal the interrelated roles of the bearing clearance, mass eccentricity and side force in producing dangerous subharmonics. The significant effects of the strong non-linearity of a bearing clearance are studied as related to the various system parameters. The results show that the approach developed in this study is computationally superior to numerical integration methods in analyzing multi-disk rotor systems with strong non-linearity.

  17. Collimated in-situ gamma spectrometry: a new method for fast clearance measurements of large areas or building structures of nuclear facilities under decommissioning

    The ideas in the late sixties which led to the use of bare spectrometric radiation detectors like NaI(Tl), Ge(Li) or nowadays high-purity germanium detectors (wage) for field measurements (in-situ gamma spectrometry) were to get easy and rapid information about the radiological state of outdoor grounds after nuclear weapon tests or to estimate dose rates created by natural radioactive nuclides in the soil. In this cases, it was assumed, that there was no disturbance of the source-detector geometry for many hundred square meters around the detector. After the nuclear accident in Chernobyl in 1986 these advantages focussed strong scientific interest at the in-situ technique and in 1993 it was established in the German regulatory for immission surveillance after significant radioactive emissions. For unrestricted release in decommissioning 'in-situ gamma spectrometry may be the only method of achieving validation of the release criteria, particularly for large areas outside the buildings'. In a late phase of the decommissioning of a nuclear power plant all components containing a significant inventor of radioactivity are removed, leaving large surfaces with often poorly knows contamination levels. Taking in account only buildings of restricted areas in the next 50 years in Germany 7E3 Mg activated and 5E6 Mg contaminated concrete must be released from facilities under decommissioning. Before the ground and the building structures of the facility can be conventionally pulled down, the remaining radioactivity must be determined in order to check the radiological relevance of the concerned part of the plant and to decide the possible path of material release. The basis of assessment may be the so-called '10 μSv-concept'. (author)

  18. Development of the clearance level verification evaluation system. 2. Construction of the clearance data management system

    Clearance is defined as the removal of radioactive materials or radioactive objects within authorized practices from any further regulatory control by the regulatory body. In Japan, clearance level and a procedure for its verification has been introduced under the Laws and Regulations, and solid clearance wastes inspected by the national authority can be handled and recycled as normal wastes. The most prevalent type of wastes have generated from the dismantling of nuclear facilities, so the Japan Atomic Energy Agency (JAEA) has been developing the Clearance Level Verification Evaluation System (CLEVES) as a convenient tool. The Clearance Data Management System (CDMS), which is a part of CLEVES, has been developed to support measurement, evaluation, making and recording documents with clearance level verification. In addition, validation of the evaluation result of the CDMS was carried out by inputting the data of actual clearance activities in the JAEA. Clearance level verification is easily applied by using the CDMS for the clearance activities. (author)

  19. Exploring the influential factors in incident clearance time: Disentangling causation from self-selection bias.

    Ding, Chuan; Ma, Xiaolei; Wang, Yinhai; Wang, Yunpeng

    2015-12-01

    Understanding the relationships between influential factors and incident clearance time is crucial to make effective countermeasures for incident management agencies. Although there have been a certain number of achievements on incident clearance time modeling, limited effort is made to investigate the relative role of incident response time and its self-selection in influencing the clearance time. To fill this gap, this study uses the endogenous switching model to explore the influential factors in incident clearance time, and aims to disentangle causation from self-selection bias caused by response process. Under the joint two-stage model framework, the binary probit model and switching regression model are formulated for both incident response time and clearance time, respectively. Based on the freeway incident data collected in Washington State, full information maximum likelihood (FIML) method is utilized to estimate the endogenous switching model parameters. Significant factors affecting incident response time and clearance time can be identified, including incident, temporal, geographical, environmental, traffic and operational attributes. The estimate results reveal the influential effects of incident, temporal, geographical, environmental, traffic and operational factors on incident response time and clearance time. In addition, the causality of incident response time itself and its self-selection correction on incident clearance time are found to be indispensable. These findings suggest that the causal effect of response time on incident clearance time will be overestimated if the self-selection bias is not considered. PMID:26373988

  20. The influence of body posture on lithium clearance

    Kamper, A L; Strandgaard, S; Holstein-Rathlou, N H;

    1988-01-01

    fall in the sitting position, and fell significantly to 26 +/- 5 ml/min (p less than 0.025) in walking subjects. Absolute proximal tubular reabsorption rate of fluid correspondingly rose from 83 +/- 16 to 92 +/- 15 ml/min (p less than 0.005) and sodium clearance fell from 1.52 +/- 0.81 to 1.00 +/- 0...... during moderate physical activity. Hence, when renal tubular function is studied with the lithium clearance method, standardization of posture and physical activity is important. In such studies physical activity such as walking should particularly be avoided....

  1. The influence of body posture on lithium clearance

    Kamper, A L; Strandgaard, S; Holstein-Rathlou, N H; Munck, O; Leyssac, P P

    1988-01-01

    measured four times at 1-week intervals: two in the supine and one in the sitting position, and one when the subject was walking around. Glomerular filtration rate was not influenced by posture changes. On the contrary, lithium clearance, which in the supine position was 30 +/- 9 ml/min (1 SD), tended to...... during moderate physical activity. Hence, when renal tubular function is studied with the lithium clearance method, standardization of posture and physical activity is important. In such studies physical activity such as walking should particularly be avoided....

  2. Determination of Glomerular Filtration Rate with 51Cr, 58Co, 114mIn, 115mIn and 169Yb- Labelled EDTA and DTPA Complexes

    Some metal complexes are suitable for determination of the glomerular filtration rate (GFR). A series of labelled EDTA and DTPA complexes have been produced during the last two years by the Isotope Institute of the Hungarian Academy of Sciences. The common property of EDTA and DTPA complexes is their great stability, which is a major advantage over the iodinated compounds. We have demonstrated that none of the complexes used by us combine with plasma proteins or penetrate into the red blood cells. There is evidence that EDTA and DTPA leave the body exclusively by way of glomerular filtration. The results of more than 600 cases are presented. 169Yb EDTA was used in 315, 51Cr EDTA in 126, 114mIn EDTA in 83, 58Co DTPA in 72 and 115mIn EDTA in 28 cases for determination of GFR. The injected activity was 0.3 -4.0 μCi/kg body weight. In most cases the result has been compared with the 24-h endogenous creatine clearance, and in 50 cases with inulin clearance also. In general the single-shot method was used. Blood samples were taken about the first and the second hour after injection of the isotope. A formula is given for calculating GFR. In a few cases we administered the isotope in the same way as inulin (priming dose and constant plasma concentration sustained by an infusion pump). Our results show that the single-shot method is a very suitable one in routine clinical practice either in states of normal or reduced kidney function. Using the single-shot method for GFR determination is especially important in those cases where the collection of urine is impossible without using a catheter, which always entails the risk of infection. Results are reliable even in disorders of the urinary tract. During or after the procedure no side effects could be observed. (author)

  3. Kidney and lung injury in irradiated rats protected from acute death by partial-body shielding

    Ninety-six CD-1 male rats were exposed to gamma-ray doses (0-25 Gy) in increments of 5 Gy. One femur, the surgically exteriorized GI tract, and the oral cavity were shielded during irradiation to protect against acute mortality from injury to the hematopoietic system, small intestine, and oral cavity. In addition, the thoraxes of half of the animals from each dose group were shielded. At approximately monthly intervals from 2 to 10 months after irradiation the hematocrit, plasma urea nitrogen (PUN), and 51Cr-EDTA clearance were measured. During the study 20 thorax-shielded and 19 thorax-irradiated animals died. All rats whose thoraxes received 25 Gy irradiation and three out of seven rats whose thoraxes received 20 Gy died 1 to 3 months postirradiation with massive pleural fluid accumulation. Shielding the thoraxes prevented this mode of death at these doses. Kidney injury was judged to be the primary cause of death of all thorax-shielded animals and 15- and 20-Gy thorax-irradiated animals. Animals with kidney damage had elevated PUN and reduced 51Cr-EDTA clearance and hematocrits. The relative merits of each of these end points in assessing radiation-induced kidney injury after total-body exposure are discussed

  4. 55Co-EDTA for renal imaging using positron emission tomography (PET): a feasibility study

    The feasibility of imaging renal function with 55Co-ethylene diamine tetraacetic acid (EDTA) and dynamic positron emission tomography was investigated. A group of normal Wistar rats was injected intravenously with 55Co-EDTA and underwent dynamic positron emission tomography (PET) imaging in order to study the biodistribution. The time-activity curves of the heart (blood pool), both kidneys, liver, and bladder were observed. In two animals, blood and urinary clearances of 55Co-EDTA were compared with those for 51Cr-EDTA. In one animal, unilateral reduction in kidney function was induced and the right/left ratio for the kidneys was determined. The time-activity curves showed that 55Co-EDTA cleared rapidly from the blood pool (heart), whereas prompt and high target-to-background ratios for both kidneys were obtained. The entire tracer was cleared from the renal parenchyma by urinary excretion and collection of the activity in the bladder. No specific activity uptake was noticed in any other organ or tissue. The clearances of 55Co-EDTA and 51Cr-EDTA in blood were not significantly different, showing that the nature of the M++ has no influence on the in vivo behavior of EDTA. 55Co can be produced easily by cyclotron irradiation and 55Co-EDTA is a promising physiological tracer for nephrological research using PET

  5. The role of neutrophilic mediators in acute inflammation of the gut

    Activation of granulocytes within the lamina propria by luminally derived bacterial products may represent an important mechanism in the pathogenesis of inflammatory bowel disease. One objective of this thesis was to determine the effects of luminal perfusion with N-formyl-methionyl-leucyl-phenylalanine (FMLP), a bacterial product that attracts and activates granulocytes, on mucosal permeability in different regions of the rat small intestine and colon. Mucosal permeability was measured using the blood-to-lumen clearance of 51Cr-EDTA during luminal perfusion with FMLP dissolved in Tyrode's solution. Of the bowel segments studied, mucosal permeability was significantly increased only in the distal 10 cm of the ileum. In order to define the role of neutrophilic oxidants in FMLP-induced ileitis, we evaluated the protective effect of several free radical scavengers and antioxidant enzymes. Pretreatment with the either superoxide dismutase or catalase had no effect on the FMLP-induced increase in mucosal permeability. However, treatment with either Mn-desferrioxamine, PZ51, desferrioxamine, or dimethylsulfoxide significantly attenuated FMLP-induced mucosal damage. Non-oxidative toxins released from activated neutrophil may be another mechanism by which FMLP increases mucosal permeability. In order to investigate the role of neutrophilic proteases in FMLP-induced ileitis, the effects of the nonspecific protease inhibitor soybean trypsin inhibitor, and the elastase inhibitors MeOSuc-Ala-Ala-Pro-Val-CH2Cl(MAAPV) and Eglin C on the FMLP-induced increases in 51Cr-EDTA clearance were determined

  6. Lactate clearance in cardiorespiratory emergency

    Serena Greco; Giovanna Guiotto; Antonino Maffei; Stefania Martino; Giuseppe Romano; Fernando Schiraldi

    2007-01-01

    Early goal directed therapy has been found to improve prognosis in septic patients, if the therapeutic goal is achieved within the first six hours. The aim of our study is to demonstrate that in patients with acute cardiorespiratory failure, rapid (within 2 hours) lactate clearance can help define patients’ prognosis. 67 consecutive patients, admitted to our 16-bed Emergency Medicine ward for acute cardiorespiratory failure (age 75,9 ± 9,8) (APACHE II score 19,0 ± 4,1), we...

  7. Mucociliary and cough clearance as a biomarker for therapeutic development

    Bennett, William D; Daviskas, Evangelia; Hasani, Amir;

    2010-01-01

    A workshop/symposium on “Mucociliary and Cough Clearance (MCC/CC) as a Biomarker for Therapeutic Development” was held on October 21–22, 2008, in Research Triangle Park, NC, to discuss the methods for measurement of MCC/CC and how they may be optimized for assessing new therapies designed to...

  8. Mucociliary and cough clearance as a biomarker for therapeutic development

    Bennett, William D; Daviskas, Evangelia; Hasani, Amir;

    2010-01-01

    A workshop/symposium on “Mucociliary and Cough Clearance (MCC/CC) as a Biomarker for Therapeutic Development” was held on October 21–22, 2008, in Research Triangle Park, NC, to discuss the methods for measurement of MCC/CC and how they may be optimized for assessing new therapies designed to impr...

  9. Mucociliary clearance, airway inflammation and nasal symptoms in urban motorcyclists

    Brant, Tereza C S; Yoshida, Carolina T; Tomas de S. Carvalho; Nicola, Marina L; Jocimar. A. Martins; Lays M. Braga; Regiani C. de Oliveira; Vilma Leyton; Carmen S. de André; Saldiva, Paulo H. N.; Rubin, Bruce K.; Naomi K. Nakagawa

    2014-01-01

    OBJECTIVES: There is evidence that outdoor workers exposed to high levels of air pollution exhibit airway inflammation and increased airway symptoms. We hypothesized that these workers would experience increased airway symptoms and decreased nasal mucociliary clearance associated with their exposure to air pollution. METHODS:...

  10. The Clearance of Cyclosporine by Hemodialysis

    Venkataramanan, Raman; Ptachcinski, Richard J.; Burckart, Gilbert J.; YANG, SHIN L.; Starzl, Thomas E.; VAN THEIL, DAVID H.

    1984-01-01

    The pharmacokinetics of cyclosporine were studied in five liver transplant patients when they were on and off hemodialysis. There was no significant difference in the blood clearance of cyclosporine between these two periods. Less than 1 per cent of the dose of cyclosporine was recovered in the dialysate. The mean dialysis clearance was less than 1 ml/min. This represents less than 1 per cent of the total blood clearance of cyclosporine. Dosage alterations of cyclosporine during or after hemo...

  11. Revolute joints with clearance in multibody systems

    Flores, Paulo; Ambrósio, Jorge

    2004-01-01

    A computational methodology for dynamic analysis of multibody mechanical systems with joint clearance is presented in this work. Clearances always exist in real joints in order to ensure the correct relative motion between the connected bodies being the gap associated to them a result of machining tolerance, wear, and local deformations. Clearance at different joints is the source for impact forces, resulting in wear and tear of the joints, and consequently the degradation of the system perfo...

  12. Mucociliary clearance in early simple chronic bronchitis

    Tracheobronchial mucociliary clearance was measured in 37 patients with early simple chronic bronchitis. A non-invasive radio-aerosol technique with inhalation of 99Tcm labelled 5-μm polystyrene particles followed by assessment of radio-nuclide distribution by posterior gamma-camera scans was employed. The mucociliary clearance of the bronchitics was significantly slower than clearance of a non-smoker control group. An interim analysis of the effect of treatment with a surfactant stimulating drug, ambroxol, suggested a dosage-dependent tendency to a faster mucociliary clearance than seen in placebo-treated bronchitics. (author)

  13. Clearance of materials, buildings and land with low content of radioactive materials. Methodology and documentation

    The concepts and methods of clearance of materials originating from the decommissioning af the nuclear facilities at Risoe National Laboratory are described as well as procedures for clearance of buildings and land. The recommendations from international organisations as well as national regulation on clearance are presented. Methods for characterisation and separation of waste being candidate for clearance are presented.Di .erent methodologies for determining the content of radionuclides in candidate waste for clearance are discussed,and the need for and construction of a low-level laboratory for activity analyses in both bulky and less bulky subjects is described. Laboratory analyses, documentation of results and education of health physics personnel is presented. (au)

  14. Mucociliary clearance, airway inflammation and nasal symptoms in urban motorcyclists

    Tereza C.S. Brant

    2014-01-01

    Full Text Available OBJECTIVES: There is evidence that outdoor workers exposed to high levels of air pollution exhibit airway inflammation and increased airway symptoms. We hypothesized that these workers would experience increased airway symptoms and decreased nasal mucociliary clearance associated with their exposure to air pollution. METHODS: In total, 25 non-smoking commercial motorcyclists, aged 18-44 years, were included in this study. These drivers work 8-12 hours per day, 5 days per week, driving on urban streets. Nasal mucociliary clearance was measured by the saccharine transit test; airway acidification was measured by assessing the pH of exhaled breath condensate; and airway symptoms were measured by the Sino-nasal Outcome Test-20 questionnaire. To assess personal air pollution exposure, the subjects used a passive-diffusion nitrogen dioxide (NO2 concentration-monitoring system during the 14 days before each assessment. The associations between NO2 and the airway outcomes were analyzed using the Mann-Whitney test and the Chi-Square test. Clinicaltrials.gov: NCT01976039. RESULTS: Compared with clearance in healthy adult males, mucociliary clearance was decreased in 32% of the motorcyclists. Additionally, 64% of the motorcyclists had airway acidification and 92% experienced airway symptoms. The median personal NO2 exposure level was 75 mg/m3 for these subjects and a significant association was observed between NO2 and impaired mucociliary clearance (p = 0.036. CONCLUSION: Non-smoking commercial motorcyclists exhibit increased airway symptoms and airway acidification as well as decreased nasal mucociliary clearance, all of which are significantly associated with the amount of exposure to air pollution.

  15. Bronchoscintigraphy and pulmonary clearance of 99mTc-albumin colloid in study of mucociliary clearance

    A radioaerosol based method for measuring MC was introduced. It included an inhalation protocol that resulted in a predominant deposition of radioaerosol in the central bronchi and two simple procedures of evaluation: 1) a visual semi-quantitative bronchoscintigraphic analysis, and 2) a quantitative analysis of the retention of the radioactivity at different points after the inhalation. The results showed that bronchoscintigraphy was a simple technique that may be used to visualize a stimulation of mucociliary transport in the central airways of individuals that do not suffer from too much mucus hypersecretion. Comparison of the MC between individuals, however, should preferably be performed by the method of quantitative analysis of the radioactivity disappearance. A change of MC was found to be one of the first detectable effects on lung function of tobacco smoking. It could be effectively detected by measurement of radioaerosol clearance both by bronchoscintigraphy and simple quantification of the MC. The MC may be either acutely enhanced, reduced or not changed by smoking. Long-term smoking impairs MC. The enhancement of MC by β2-agonists was very limited in most patients with CF. In the hope of increasing mucus transport in patients with CF, these are treated with various chest physiotherapy techniques. The radioaerosol based method of measurement of MC could assess mucus clearance by chest physiotherapy and cough. (au)

  16. 30 CFR 56.7018 - Hand clearance.

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Hand clearance. 56.7018 Section 56.7018 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling § 56.7018 Hand clearance....

  17. Cortisol does not inhibit prednisolone clearance.

    Meffin, P J; Sallustio, B C; Purdie, Y J; Robson, R A; Wing, L M; Brooks, P M

    1985-01-01

    The disposition of prednisolone has been studied in eight male subjects with and without the concomitant administration of cortisol which produced plasma cortisol concentrations 10-fold higher than endogenous levels. The clearance and steady-state distribution volume of total prednisolone were increased as was the prednisolone free fraction but the clearance of unbound prednisolone was unaltered by cortisol co-administration.

  18. 30 CFR 56.11008 - Restricted clearance.

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Restricted clearance. 56.11008 Section 56.11008 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Travelways § 56.11008 Restricted clearance. Where...

  19. 28 CFR 524.74 - Activities clearance.

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Activities clearance. 524.74 Section 524.74 Judicial Administration BUREAU OF PRISONS, DEPARTMENT OF JUSTICE INMATE ADMISSION, CLASSIFICATION, AND TRANSFER CLASSIFICATION OF INMATES Central Inmate Monitoring (CIM) System § 524.74 Activities clearance. (a) Except as provided for in...

  20. 14 CFR 23.925 - Propeller clearance.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller clearance. 23.925 Section 23.925 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant General § 23.925 Propeller clearance. Unless...

  1. Vest Chest Physiotherapy Airway Clearance is Associated with Nitric Oxide Metabolism

    Joseph H. Sisson

    2013-01-01

    Full Text Available Background. Vest chest physiotherapy (VCPT enhances airway clearance in cystic fibrosis (CF by an unknown mechanism. Because cilia are sensitive to nitric oxide (NO, we hypothesized that VCPT enhances clearance by changing NO metabolism. Methods. Both normal subjects and stable CF subjects had pre- and post-VCPT airway clearance assessed using nasal saccharin transit time (NSTT followed by a collection of exhaled breath condensate (EBC analyzed for NO metabolites (. Results. VCPT shorted NSTT by 35% in normal and stable CF subjects with no difference observed between the groups. EBC concentrations decreased 68% in control subjects after VCPT (before = 115 ± 32 μM versus after = 37 ± 17 μM; . CF subjects had a trend toward lower EBC . Conclusion. We found an association between VCPT-stimulated clearance and exhaled levels in human subjects. We speculate that VCPT stimulates clearance via increased NO metabolism.

  2. Active generalized predictive control of turbine tip clearance for aero-engines

    Peng Kai; Fan Ding; Yang Fan; Fu Qiang; Li Yong

    2013-01-01

    Active control of turbine blade tip clearance continues to be a concern in design and con-trol of gas turbines. Ever increasing demands for improved efficiency and higher operating temper-atures require more stringent tolerances on turbine tip clearance. In this paper, a turbine tip clearance control apparatus and a model of turbine tip clearance are proposed;an implicit active generalized predictive control (GPC), with auto-regressive (AR) error modification and fuzzy adjustment on control horizon, is presented, as well as a quantitative analysis method of robust per-turbation radius of the system. The active clearance control (ACC) of aero-engine turbine tip clear-ance is evaluated in a lapse-rate take-off transient, along with the comparative and quantitative analysis of the stability and robustness of the active tip clearance control system. The results show that the resultant active tip clearance control system with the improved GPC has favorable steady-state and dynamic performance and benefits of increased efficiency, reduced specific fuel consump-tion, and additional service life.

  3. Effect of prior immobilization on muscular glucose clearance in resting and running rats

    In vitro studies have shown that prior disuse impairs the glucose clearance of red skeletal muscle because of a developed insensitivity to insulin. We studied whether an impaired glucose clearance is present in vivo in 42-h immobilized muscles of resting rats and, furthermore, whether the exercise-induced increase in glucose clearance of red muscles is affected by prior immobilization. The 2-[3H]deoxy-D-glucose (2DG) bolus injection method was used to determine glucose clearance of individual muscles. At rest, glucose clearance was markedly impaired in rats with previously immobilized red muscles compared with nonimmobilized control rats. During running, glucose clearance did not differ between muscles in previously immobilized and control rats. Insulin levels were always similar in the two groups and decreased during exercise. Intracellular nonphosphorylated 2DG was present in tissues with high glucose clearances. In conclusion, 42 h of immobilization markedly impairs glucose clearance of resting red muscle fibers in vivo. Apparently, physical inactivity in particular affects steps involved in insulin-mediated action that are not part of contraction-induced glucose uptake and metabolism. Presence of intracellular 2DG shows that separate determination of phosphorylated 2DG is necessary for accurate estimates of glucose metabolism and that accumulation of phosphorylated 2DG does not accurately reflect glucose transport

  4. A pre- and postoperative study of split isotope clearance in childhood

    In 1978 43 patients have been operated in the Department of Pediatric Surgery, Krankenhaus Muenchen-Schwabing, because of recurrent urinary-tract infections with ureterovesical reflux or obstructive urinary-tract diseases. In all patients a split whole body clearance-study with a method modified after the method of Muehle with 131J-Hippuran was carried out pre- or postoperatively, respectively. In 78,5% of these cases the clearance-results were corresponding to the results of X-ray examination; 6 of the remaining patients had a worse clearance result and 3 had a better result than the X-ray findings would have suggested. (orig.)

  5. Numerical analysis of bump foil bearings without nominal radial clearance

    LIU Zhan-sheng; XU Huai-jin; ZHANG Guang-hui

    2008-01-01

    Bump foil bearings without nominal radial clearance were analyzed. An air film thickness model and a bearing theoretical analytical model were developed accounting for air compressibility and foil deformation. To analyze hydrodynamic characteristics of bump foil beatings with different operating eccentricities, the air film thickness equation and Reynolds equation were coupled through pressure and solved by Newton-Raphson Method(NRM) and Finite Difference Method (FDM). The characteristics of an bump foil bearing model were dis-cussed including load carrying capacity, film thickness and pressure distributions. The results of simulation show that bump foil beating without nominal radial clearance can provide better stability and greater load capaci-ty. This numerical analytical method also reveals a good convergence in numerical calculation.

  6. Radial Clearance Control and Internal Leakage Analysis of a Tri-Proportion Controller

    LI Dai-jin; ZHANG Yu-wen; TANG Hao; DANG Jian-jun; LUO Kai

    2009-01-01

    The tri-propellant thermal propulsion system is one of the hottest subjects in the.field of underwater vehicles recently. To improve efficiency of underwater vehicles, a method of radial clearance control of the tri-proportion has been proposed. Based on analyzing the factors which influence the pressure decrease and leakage of the tri-proportion controller, a method is used for precision analysis and proportion adjustment by using the median optimizing theory. Analysis results show that accuracy of the proportion controller is dependent on all the leakage, while the leakage is decided by radial clearance and pressure; the leakage can be controlled effectively and the accuracy of the proportion can be improved with the radial clearance control method. The method of accuracy analysis and clearance control has value on the design of various hydraulic motors.

  7. Factors contributing to delay in parasite clearance in uncomplicated falciparum malaria in children

    Sijuade Abayomi

    2010-02-01

    Full Text Available Abstract Background Drug resistance in Plasmodium falciparum is common in many endemic and other settings but there is no clear recommendation on when to change therapy when there is delay in parasite clearance after initiation of therapy in African children. Methods The factors contributing to delay in parasite clearance, defined as a clearance time > 2 d, in falciparum malaria were characterized in 2,752 prospectively studied children treated with anti-malarial drugs between 1996 and 2008. Results 1,237 of 2,752 children (45% had delay in parasite clearance. Overall 211 children (17% with delay in clearance subsequently failed therapy and they constituted 72% of those who had drug failure, i.e., 211 of 291 children. The following were independent risk factors for delay in parasite clearance at enrolment: age less than or equal to 2 years (Adjusted odds ratio [AOR] = 2.13, 95% confidence interval [CI]1.44-3.15, P 50,000/ul (AOR = 2.21, 95% CI = 1.77-2.75, P 20000/μl a day after treatment began, were independent risk factors for delay in clearance. Non-artemisinin monotherapies were associated with delay in clearance and treatment failures, and in those treated with chloroquine or amodiaquine, with pfmdr 1/pfcrt mutants. Delay in clearance significantly increased gametocyte carriage (P Conclusion Delay in parasite clearance is multifactorial, is related to drug resistance and treatment failure in uncomplicated malaria and has implications for malaria control efforts in sub-Saharan Africa.

  8. Capillary permeability in adipose tissue

    Paaske, W P; Nielsen, S L

    1976-01-01

    A method for measurement of capillary permeability using external registration of gamma emitting isotopes after close arterial bolus injection was applied to the isolated inguinal fat pad in slightly fasting rabbits. An average extraction of 26 per cent for 51Cr-EDTA was found at a plasma flow of...... about 7 ml/100 g-min. This corresponds to a capillary diffusion capacity of 2.0 ml/100 g-min which is half the value reported for vasodilated skeletal muscle having approximately twice as great capillary surface area. Thus, adipose tissue has about the same capillary permeability during slight metabolic...

  9. Characterization and Clearance of m/s Sigyn

    M/s Sigyn was a 2044 ton ship that transported contaminated material between 1982 and 2013. Most of the transports were with spent nuclear fuel between Swedish nuclear power plants and the Swedish fuel repository, Clab. In addition to spent fuel, m/s Sigyn also transported big contaminated components, from nuclear power plants in Europe, to Studsvik for analysis or decontamination and melting. She also transported components from Swedish nuclear power plants to final disposal of short lived waste, SFR. Even though all transported items have been cleaned, checked and wrapped with plastics, some activity ended up as contamination onboard. In December 2013 it was decided that m/s Sigyn was subject for decommissioning due to her age. This Paper describes the method in which the activity onboard m/s Sigyn was characterized and clearance levels were calculated. This method for radiological characterization and clearance has recently been developed in Sweden, the method is efficient in that it does not need a big pre characterization survey. Only the nuclide distribution and history of the object, is needed to start the final survey. In the future there will be further development of the method, making it possible to reduce the number of measurements even more. This will further optimize the method and reduce the cost for final surveys and clearance. (authors)

  10. Influence of chronic dosing on theophylline clearance.

    Efthimiou, H; Morgan, D. J.; Ioannides-Demos, L; Raymond, K.; McLean, A. J.

    1984-01-01

    Theophylline clearance was studied in normal healthy volunteers before and after chronic oral dosing. Oral theophylline clearance showed a significant decrease (P less than 0.001) from 59.3 +/- 6.48 ml/min (mean +/- s.e. mean, n = 10) to 48.0 +/- 6.4 ml/min. Steady-state intravenous clearance decreased by 26 +/- 2% from 55.1 +/- 7.7 ml/min to 41.0 +/- 5.96 ml/min (mean +/- s.e. mean, n = 6; P less than 0.001) at constant steady-state intravenous test concentrations (mean 15.0 +/- 1.6 microgra...

  11. Nucleotide-mediated airway clearance.

    Schmid, Andreas; Clunes, Lucy A; Salathe, Mathias; Verdugo, Pedro; Dietl, Paul; Davis, C William; Tarran, Robert

    2011-01-01

    A thin layer of airway surface liquid (ASL) lines the entire surface of the lung and is the first point of contact between the lung and the environment. Surfactants contained within this layer are secreted in the alveolar region and are required to maintain a low surface tension and to prevent alveolar collapse. Mucins are secreted into the ASL throughout the respiratory tract and serve to intercept inhaled pathogens, allergens and toxins. Their removal by mucociliary clearance (MCC) is facilitated by cilia beating and hydration of the ASL by active ion transport. Throughout the lung, secretion, ion transport and cilia beating are under purinergic control. Pulmonary epithelia release ATP into the ASL which acts in an autocrine fashion on P2Y(2) (ATP) receptors. The enzymatic network describes in Chap. 2 then mounts a secondary wave of signaling by surface conversion of ATP into adenosine (ADO), which induces A(2B) (ADO) receptor-mediated responses. This chapter offers a comprehensive description of MCC and the extensive ramifications of the purinergic signaling network on pulmonary surfaces. PMID:21560046

  12. Kinetics of various sup(99m)Tc-Sn-pyrophosphate compounds in the rat. Pt. 1

    The kinetic data of two different sup(99m)Tc-Sn-pyrophosphate compounds (compound A and B) were evaluated in non-adult rats. Only compound A concentrated in bone. Both compounds dispersed rapidly in the intravascular as well as the extravascular space. The plasma protein bond of both compounds increased with time after injection and impaired both the renal clearance of both compounds and the bone clearance of compound A. The renal clearance of both compounds was somewhat above that of 51Cr-EDTA. It is concluded that compound A and B is mainly excreted by glomerular filtration. About one fourth of the glomerular filtrate of compound B is reabsorbed and accumulated by the tubular cells. (orig.)

  13. Pressure losses and flow field distortion induced by tip clearance of centrifugal and axial compressors

    Senoo, Yasutoshi

    1987-03-01

    The flow field near the tip of compressor rotor blades is distorted by leakage through the tip clearance and the performance of the compressor is deteriorated. The literature regarding the tip clearance of compressor blades consists of computational fluid mechanics and experimental studies on the flow field and the pressure loss. Empirical equations expressing the pressure loss and the efficiency drop are varied. They relate to the lift coefficient in different ways, depending upon the ways of understanding the mechanics of pressure losses. These methods are examined and compared. Also, a brief discussion is made on the optimum value of the tip clearance.

  14. Dual roles for hepatic lectin receptors in the clearance of chilled platelets

    Rumjantseva, Viktoria; Grewal, Prabhjit K; Wandall, Hans H;

    2009-01-01

    Rapid chilling causes glycoprotein-Ib (GPIb) receptors to cluster on blood platelets. Hepatic macrophage beta(2) integrin binding to beta-N-acetylglucosamine (beta-GlcNAc) residues in the clusters leads to rapid clearance of acutely chilled platelets after transfusion. Although capping the beta......-Morell receptor binding, become increasingly involved in platelet removal. Macrophages rapidly removed a large fraction of transfused platelets independent of their storage conditions. With prolonged platelet chilling, hepatocyte-dependent clearance further diminishes platelet recovery and survival after...... transfusion. Inhibition of chilled platelet clearance by both beta(2) integrin and Ashwell-Morell receptors may afford a potentially simple method for storing platelets in the cold....

  15. Deposition of aerosols and bronchial clearance measurements

    A special inhalative device is described for reproducible deposition patterns of radioactive aerosols to measure mucociliary and tussive clearance and to evaluate the effect of drugs on the bronchial tree is described. Additive actions on mucus transport exist between β2-agonists and theophylline, but not incombination with inhalative quarternary ammonium compounds (ipatropium and oxitropium bromide). Mucolytics are generally less effective on mucociliary clearance than β2-agonists and theophylline, positive, negative and nonresponders are ofter seen due to the different viscoelastic properties of the mucus. Mucus transport is more than mucociliary clearance. Two-phase gas/liquid movement and coughing are also important transport mechanisms for bronchial mucus. Therefore, bronchodilators enhance mucus transport by increasing airway patency, which increases total and regional air flow and improves cough clearance. (orig.)

  16. Compressor airfoil tip clearance optimization system

    Little, David A.; Pu, Zhengxiang

    2015-08-18

    A compressor airfoil tip clearance optimization system for reducing a gap between a tip of a compressor airfoil and a radially adjacent component of a turbine engine is disclosed. The turbine engine may include ID and OD flowpath boundaries configured to minimize compressor airfoil tip clearances during turbine engine operation in cooperation with one or more clearance reduction systems that are configured to move the rotor assembly axially to reduce tip clearance. The configurations of the ID and OD flowpath boundaries enhance the effectiveness of the axial movement of the rotor assembly, which includes movement of the ID flowpath boundary. During operation of the turbine engine, the rotor assembly may be moved axially to increase the efficiency of the turbine engine.

  17. Clearance of germ granules in the soma

    Sugimoto, Asako

    2009-01-01

    Germ granules are ribonucleoprotein complexes specifically segregated into germ cell lineages in diverse organisms. Recent studies indicate that multiple mechanisms are involved in the clearance of germ granules and their components in somatic cells in Caenorhabditis elegans embryos.

  18. Glial K(+) Clearance and Cell Swelling

    Macaulay, Nanna; Zeuthen, Thomas

    2012-01-01

    space into the glial cell are debated. Although spatial buffer currents may occur, their quantitative contribution to K(+) clearance is uncertain. The concept of spatial buffering of K(+) precludes intracellular K(+) accumulation and is therefore (i) difficult to reconcile with the K(+) accumulation...... repeatedly observed in glial cells during K(+) clearance and (ii) incompatible with K(+)-dependent glial cell swelling. K(+) uptake into non-voltage clamped cultured glial cells is carried out by the Na(+)/K(+)-ATPase and the Na(+)/K(+)/Cl(-) cotransporter in combination. In brain slices and intact optic...... nerve, however, only the Na(+)/K(+)-ATPase has been demonstrated to be involved in stimulus-evoked K(+) clearance. The glial cell swelling associated with K(+) clearance is prevented under conditions that block the activity of the Na(+)/K(+)/Cl(-) cotransporter. The Na(+)/K(+)/Cl(-) cotransporter is...

  19. The curious world of apoptotic cell clearance

    Weitzman, Jonathan B

    2004-01-01

    Analysis of knockout mice has brought into question the previously proposed role of the phosphatidylserine receptor (Ptdsr) in the clearance of apoptotic cell corpses, and has suggested important functions in regulating differentiation and inflammation.

  20. Exclusion, exemption, clearance European Union approach

    The presentation overviews the following issues: Euratom Basic Safety Standards; administrative requirements; radiation protection of the population. Scope of the Standards: natural radiation sources; exclusion. Exemption; Clearance; Import of radioactive scrap metal

  1. Mucociliary clearance, airway inflammation and nasal symptoms in urban motorcyclists

    Brant, Tereza C S; Yoshida, Carolina T; de S. Carvalho, Tomas; Marina L. Nicola; Jocimar A. Martins; Lays M. Braga; de Oliveira, Regiani C; Leyton, Vilma; Carmen S. de André; Saldiva, Paulo H N; Rubin, Bruce K; Naomi K. Nakagawa

    2014-01-01

    OBJECTIVES: There is evidence that outdoor workers exposed to high levels of air pollution exhibit airway inflammation and increased airway symptoms. We hypothesized that these workers would experience increased airway symptoms and decreased nasal mucociliary clearance associated with their exposure to air pollution. METHODS: In total, 25 non-smoking commercial motorcyclists, aged 18-44 years, were included in this study. These drivers work 8-12 hours per day, 5 days per week, driving on urba...

  2. Blade by Blade Tip Clearance Measurement

    A. G. Sheard

    2011-01-01

    This paper describes a capacitance-based tip clearance measurement system which engineers have used in the most demanding turbine test applications. The capacitance probe has survived extended use in a major European gas turbine manufacturer's high-temperature demonstrator unit, where it functioned reliably at a turbine entry temperature in excess of 1800 degrees Kelvin. This paper explores blade by blade tip clearance measurement techniques and examines probe performance under laboratory con...

  3. Clearance of inhaled particles in ankylosing spondylitis.

    Farquhar, D R; Chamberlain, M. J.; McCain, G A; Morgan, W K

    1989-01-01

    Patients with ankylosing spondylitis may uncommonly develop apical fibrobullous lung disease, the cause of which is unknown. It is postulated here that rigidity of the thoracic cage leads to reduced apical clearance of inhaled particles and may thereby predispose to chronic infection. Deposition and clearance of inhaled technetium-99m sulphur colloid particles were studied in eight male patients with ankylosing spondylitis who had chest wall rigidity (mean (SD) chest expansion 1.8 (1.07) cm) ...

  4. Reduction of antipyrine clearance in psoriasis.

    Marsden, J R; Williams, F M; Keys, B; Rawlins, M D; Shuster, S

    1984-01-01

    Antipyrine clearance was determined in 41 psoriatics and age-sex matched controls, using sequential measurements of salivary concentration. Antipyrine clearance and elimination rate constant were less in psoriatics (P less than 0.05) and apparent volumes of distribution were similar. These differences were greater between female psoriatics and controls (P less than 0.025; P less than 0.05) and the differences between male psoriatics and controls were not significant. Correlation of simultaneo...

  5. Extreme contagion in global habitat clearance

    Boakes, Elizabeth H.; Mace, Georgina M; Philip J K McGowan; Fuller, Richard A.

    2009-01-01

    Habitat clearance remains the major cause of biodiversity loss, with consequences for ecosystem services and for people. In response to this, many global conservation schemes direct funds to regions with high rates of recent habitat destruction, though some also emphasize the conservation of remaining large tracts of intact habitat. If the pattern of habitat clearance is highly contagious, the latter approach will help prevent destructive processes gaining a foothold in areas of contiguous in...

  6. Hemodialysis clearance of metronidazole and its metabolites.

    Lau, A. H.; Chang, C W; Sabatini, S

    1986-01-01

    Metronidazole is now being used with increasing frequency for various infectious conditions in patients with renal failure. It is commonly administered to septic patients who have developed acute renal failure requiring hemodialysis. The hemodialysis clearances of metronidazole and its metabolites were evaluated in nine renal failure patients on maintenance hemodialysis. The mean +/- standard deviation clearance and the extraction ratio were 106.9 +/- 16.3 ml/min and 0.65 +/- 0.08, respective...

  7. Modelling of Outer and Inner Film Oil Pressure for Floating Ring Bearing Clearance in Turbochargers

    Zhang, Hao; Shi, Zhanqun; Gu, Fengshou; Ball, Andrew

    2011-07-01

    Floating ring bearing is widely used in turbochargers to undertake the extreme condition of high rotating speed and high operating temperature. It is also the most concerned by the designers and users alike due to its high failure rate and high maintenance cost. Any little clearance change may result in oil leakage, which in turn cause blue smoke or black smoke according to leakage types. However, there is no condition monitoring of this bearing because it is almost impossible to measure the clearance especially the inner clearance, in which the inner oil film directly bears the high speed rotation. In stead of measuring clearance directly, this paper has proposed a method that uses film pressure as a measure to monitor the bearing clearance and its variation. A non-linear mathematical model is developed by using Reynolds equations with non-linear oil film pressure. A full description of the outer and inner film is provided along both axial and radial directions. A numerical simulation is immediately carried out. Variable clearance changes are investigated using the mathematical model. Results show the relationship between clearance and film pressure.

  8. Modelling of Outer and Inner Film Oil Pressure for Floating Ring Bearing Clearance in Turbochargers

    Zhang Hao; Shi Zhanqun; Gu Fengshou; Ball, Andrew, E-mail: h.zhang3@hud.ac.uk [University of Huddersfield, Huddersfield, HD1 3DH (United Kingdom)

    2011-07-19

    Floating ring bearing is widely used in turbochargers to undertake the extreme condition of high rotating speed and high operating temperature. It is also the most concerned by the designers and users alike due to its high failure rate and high maintenance cost. Any little clearance change may result in oil leakage, which in turn cause blue smoke or black smoke according to leakage types. However, there is no condition monitoring of this bearing because it is almost impossible to measure the clearance especially the inner clearance, in which the inner oil film directly bears the high speed rotation. In stead of measuring clearance directly, this paper has proposed a method that uses film pressure as a measure to monitor the bearing clearance and its variation. A non-linear mathematical model is developed by using Reynolds equations with non-linear oil film pressure. A full description of the outer and inner film is provided along both axial and radial directions. A numerical simulation is immediately carried out. Variable clearance changes are investigated using the mathematical model. Results show the relationship between clearance and film pressure.

  9. Turbulent Heat Transfer of a Finned Plate in a Duct as Tip Clearance Changes

    Fins are employed to enhance the cooling performance of a system. There are a number of studies relevant to geometry of fins. Meanwhile, the studies relevant to tip clearance, have not performed enough, which is the distance between the tips of the fins and the wall. We investigated the optimal tip clearance, which maximizes the heat transfers by experimental and numerical analyses with wider range of ReDh than the previous studies. Turbulent heat transfers of a finned plate were measured. For an extended range of tip clearance and ReDh than other studies. A joint experimental and numerical analyses was performed to measure heat transfers. Mass transfer experiments using electroplating system was used and FLUENT 6.3.26 was used for the calculation. For the narrow tip clearances below 5 mm, were investigated by numerical method only. The bypass flow to the tip clearance region contributes to heat transfer area at the tip clearance region and does not contributes that of the fin region. Thus, the optimal tip clearance was founded and it exists vicinity of 0.2 mm

  10. Turbulent Heat Transfer of a Finned Plate in a Duct as Tip Clearance Changes

    Park, Hae-Kyun; Chung, Bum-Jin [Kyung Hee University, Yongin (Korea, Republic of)

    2015-05-15

    Fins are employed to enhance the cooling performance of a system. There are a number of studies relevant to geometry of fins. Meanwhile, the studies relevant to tip clearance, have not performed enough, which is the distance between the tips of the fins and the wall. We investigated the optimal tip clearance, which maximizes the heat transfers by experimental and numerical analyses with wider range of Re{sub Dh} than the previous studies. Turbulent heat transfers of a finned plate were measured. For an extended range of tip clearance and Re{sub Dh} than other studies. A joint experimental and numerical analyses was performed to measure heat transfers. Mass transfer experiments using electroplating system was used and FLUENT 6.3.26 was used for the calculation. For the narrow tip clearances below 5 mm, were investigated by numerical method only. The bypass flow to the tip clearance region contributes to heat transfer area at the tip clearance region and does not contributes that of the fin region. Thus, the optimal tip clearance was founded and it exists vicinity of 0.2 mm.

  11. 19 CFR 4.61 - Requirements for clearance.

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Requirements for clearance. 4.61 Section 4.61 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY VESSELS IN FOREIGN AND DOMESTIC TRADES Foreign Clearances § 4.61 Requirements for clearance. (a) Application for clearance. A...

  12. 48 CFR 801.602-76 - Business clearance review.

    2010-10-01

    ... obtain a business clearance review prior to award of any contract, task or delivery order, or blanket... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Business clearance review... Authority, and Responsibilities 801.602-76 Business clearance review. (a) A business clearance review is...

  13. Effects and outcome of Tamsulosin more than just stone clearance after extracorporeal shock wave lithotripsy for renal calculi

    Objective: To determine the effect of Tamsulosin, as adjunctive medical therapy after Extracorporeal Shock Wave Lithotripsy for renal stones on rate of stone clearance, clearance time, pain intensity during stone clearance, steinstrasse formation and auxiliary surgical intervention required. Method: A prospective randomized controlled study was carried out in 120 patients who underwent ESWL for renal stones of 0.5-2.0 cm. They were randomized into study and control group in which Tamsulosin 0.4mg/day was given in former as an adjunctive medical therapy. All patients underwent ESWL every 2 weeks until complete stone clearance for 8 weeks. The parameters assessed were stone clearance, clearance time, pain intensity and effect on steinstrasse. Results: Of the 120 patients 60 were in each group. The stone clearance rate was greater in study than in control group, 58(96.7%) vs. 48(80%) respectively, (p<0.004). The mean stone clearance time was observed earlier in study group as compared to control group with significant statistical difference in stone size between 0.6-1.5 cm. The mean intensity of pain patients experienced according to Visual analogue scale (VAS) was significantly less in study group (p<0.002). The rate of steinstrasse formation was observed to be higher in control than in study group 15(25%) vs 6(10%) respectively(p<0.003), while its spontaneous clearance was higher in study group than in control group 83.3% vs 33.3% (p<0.03). Conclusion: Tamsulosin significantly increases stone clearance after shock wave lithotripsy for renal stones. It also appeared to facilitate earlier stone clearance, reduces severity of pain, reduces the incidence of steinstrasse formation and tends to facilitate its spontaneous clearance. (author)

  14. Preparation of iodine-125-labeled iothalamate for renal clearance measurements

    Iothalamate, a derivative of benzoic acid, is used as a contrast medium for renal function studies, particularly for measurement of glomerular filtration rate. Its chemical composition and clearance properties are similar to those of diatrizoate. The structural differences between these groups of iodinated benzoic acid derivatives are dependent on the groups attached at the 3- and 5-positions of 2,4,6-tri-iodobenzoic acid. The renal clearance of sodium iothalamate in humans closely approximates that of inulin, and it is used as a replacement for inulin in determining glomerular filtration rate. /sup 125/I-labeled iothalamate sodium can be prepared by the exchange-labeling method at pH 4.0. Iothalamate must first be isolated from the contrast medium preparation and purified before radioiodination. After radioiodination, the product is purified by means of precipitation and is then converted to the sodium salt

  15. Relationship of Insulin Sensitivity, Insulin Secretion, and Adiposity With Insulin Clearance in a Multiethnic Population

    Lorenzo, Carlos; Hanley, Anthony J.G.; Wagenknecht, Lynne E; Rewers, Marian J.; Stefanovski, Darko; Goodarzi, Mark O.; Haffner, Steven M

    2012-01-01

    OBJECTIVE We aimed to examine insulin clearance, a compensatory mechanism to changes in insulin sensitivity, across sex, race/ethnicity populations, and varying states of glucose tolerance. RESEARCH DESIGN AND METHODS We measured insulin sensitivity index (S I), acute insulin response (AIR), and metabolic clearance rate of insulin (MCRI) by the frequently sampled intravenous glucose tolerance test in 1,295 participants in the Insulin Resistance Atherosclerosis Study. RESULTS MCRI was positive...

  16. Clearance from the mouse brain by convection of interstitial fluid towards the ventricular system

    Bedussi, Beatrice; van Lier, Monique G. J. T. B.; Bartstra, Jonas W.; de Vos, Judith; Siebes, Maria; VanBavel, Ed; Bakker, Erik N.T.P.

    2015-01-01

    Background In the absence of a true lymphatic system in the brain parenchyma, alternative clearance pathways for excess fluid and waste products have been proposed. Suggested mechanisms for clearance implicate a role for brain interstitial and cerebrospinal fluids. However, the proposed direction of flow, the anatomical structures involved, and the driving forces are controversial. Methods To trace the distribution of interstitial and cerebrospinal fluid in the brain, and to identify the anat...

  17. Transient Proteolytic Modification of Mesenchymal Stromal Cells Increases Lung Clearance Rate and Targeting to Injured Tissue

    Kerkelä, Erja; Hakkarainen, Tanja; Mäkelä, Tuomas; Raki, Mari; Kambur, Oleg; Kilpinen, Lotta; Nikkilä, Janne; Lehtonen, Siri; Ritamo, Ilja; Pernu, Roni; Pietilä, Mika; Takalo, Reijo; Juvonen, Tatu; Bergström, Kim; Kalso, Eija

    2013-01-01

    This study showed that an alternative cell detachment of mesenchymal stromal/stem cells (MSCs) with pronase instead of trypsin significantly accelerated the lung clearance of the cells and, importantly, increased their targeting to an area of injury. Pronase detachment could be used as a method to improve the MSC lung clearance and targeting in vivo. This may have a major impact on the bioavailability of MSCs in future therapeutic regimes.

  18. Effect of Guide Vane Clearance Gap on Francis Turbine Performance

    Ravi Koirala

    2016-04-01

    Full Text Available Francis turbine guide vanes have pivoted support with external control mechanism, for conversion of pressure to kinetic energy and to direct them to runner vanes. This movement along the support is dependent on variation of load and flow (operating conditions. Small clearance gaps between facing plates and the upper and lower guide vane tips are available to aid this movement, through which leakage flow occurs. This secondary flow disturbs the main flow stream, resulting performance loss. Additionally, these increased horseshoe vortex, in presence of sand, when crosses through the gaps, both the surfaces are eroded. This causes further serious effect on performance and structural property by increasing gaps. This paper discusses the observation of the severity in hydropower plants and effect of clearance gaps on general performance of the Francis turbine through computational methods. It also relates the primary result with the empirical relation for leakage flow prediction. Additionally, a possible method to computationally estimate thickness depletion has also been presented. With increasing clearance gap, leakage increases, which lowers energy conversion and turbine efficiency along with larger secondary vortex.

  19. 75 FR 25037 - Lead; Clearance and Clearance Testing Requirements for the Renovation, Repair, and Painting Program

    2010-05-06

    ... Protection Agency 40 CFR Part 745 Lead; Clearance and Clearance Testing Requirements for the Renovation..., 2010 / Proposed Rules#0;#0; ] ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 745 RIN 2070-AJ57 Lead... 2008 Lead Renovation, Repair, and Painting Program (RRP) rule that established accreditation,...

  20. 75 FR 38959 - Lead; Clearance and Clearance Testing Requirements for the Renovation, Repair, and Painting...

    2010-07-07

    ... established in the Federal Register of May 6, 2010 (75 FR 25038) (FRL-8823-5). In that document, EPA proposed... AGENCY 40 CFR Part 745 RIN 2070-AJ57 Lead; Clearance and Clearance Testing Requirements for the... Federal Register of May 6, 2010, concerning several revisions to the 2008 Lead Renovation, Repair,...

  1. Technetium 99m mercaptoacetyltriglycine gamma camera clearance calculations: Methodological problems

    Major sources of errors in the gamma-camera methods for the calculation of renal clearance are the accuracy of background correction for obtaining the true renal time-activity curve and the validity of the externally recorded pre-cordial activity as an estimate of the plasmatic time-activity curve. With technetium 99m mercaptoacetyltriglycine (99mTc-MAG3), because of its high protein plasma binding, one could expect minimal extravascular diffusion and hence a more accurate externally detected plasmatic curve. The high extraction rate should reduce the influence of the background, but, on the other hand, the effect of hepatobiliary excretion on the calculation of renal clearance might be significant. Our results suggest that the hepatobiliary excretion of 99mTc-MAG3 does not influence the gamma-camera renal clearance determination, even in patients with low renal function. However, the pre-cordial curve does not reflect accurately the plasmatic disappearance curve; its calibration with a single plasma sample taken at the 20th min is responsible for significant errors, probably because of an unfavourable ratio between the intravascular and extravascular activities at the 20th min. (orig.)

  2. DOES BODY MASS INDEX INFLUENCE NASAL MUCOCILIARY CLEARANCE?

    Tamilselvan K, Latha R, Nirmala N, Susiganeshkumar E, Thananjayam A

    2015-01-01

    Full Text Available Background: The respiratory system is constantly exposed to particulate matter suspended in the inhaled air and one among the efficient mechanisms to trap and expel the particulate substances is the nasal and bronchial mucociliary clearance mechanism. This mucociliary clearance mechanism is influenced by both physiological and pathological factors that alter the functioning of the respiratory cilia and the overlying mucosal layer that traps the particulate agents. As Body mass index (BMI determines the health of a person by influencing various physiological parameters, this study has been planned to study the effect of normal and abnormal BMI (overweight and obese range on the nasal mucociliary clearance (NMC. Aim: To evaluate the effect of BMI on nasal mucociliary clearance (NMC. Materials & Methods: NMC was measured in 20 volunteers with normal BMI (18.5-22.9 Kg/m2 and 20 volunteers with BMI in overweight and obese range (23 Kg/m2 and above. The NMC time was recorded by the time the volunteers appreciated the sweet taste following the placement of ¼ of saccharin tablet (1mm x 1mm in the nostril referred as saccharin transit time (STT.Results: NMC was found to be prolonged in overweight and obese population and BMI has positive correlation with NMC as calculated by Pearson correlation with r value of 0.591 and p value 0.001 which is statistically significant. Conclusion: NMC time is prolonged in abnormal BMI referring to the impairment in the mucociliary escalator mechanism thus predisposing to disease states.

  3. Effect of high mannose glycan pairing on IgG antibody clearance.

    Liu, Yaoqing Diana; Flynn, Gregory C

    2016-05-01

    IgG antibodies contain N-linked glycans on the Fc portion of each heavy chain. The glycan on one heavy chain can either match the glycan on the other heavy chain (symmetrical pairing) or be different (asymmetrical pairing). These Fc glycans influence effector functions and can alter clearance rates. Previous studies showing that high mannose forms result in faster mAb clearance in humans were incapable of differentiating the impact of symmetrically vs. asymmetrically paired HM forms, and, therefore, the effect of pairing on clearance was not clear. Traditional analytical methods, which are used to measure glycans in such studies, do not determine the number of HM glycans per antibody. With a sensitive method designed to measure HM pairing, we followed the levels of symmetrically and asymmetrically paired HM on antibodies in human pharmacokinetic serum samples to determine the impact of Fc HM glycan pairing on therapeutic human IgG clearance in humans. The two HM paired forms cleared at the same rate, indicating that the effect on clearance was not proportional to the degree of modification. Since both forms can exist on therapeutic antibodies and the ratio can differ between products, measuring their relative levels is necessary to properly estimate effects on clearance. PMID:26992607

  4. Establishment and use of surgical rat models for assessment of organ specific in vivo clearance.

    Vestergaard, Bill

    2016-06-01

    models previously used as tools to investigate renal and hepatic clearance. An overview of the surgical procedures previously described for establishment of in vivo nephrectomy and hepatectomy models is given. Many different surgical methods have been employed in the attempt to make anephric or anhepatic in vivo models. The overall conclusion of the literature review was that a suitable clearance model would require only one surgical procedure. Furthermore, the clearance studies should be conducted immediately after completed surgery to decrease the impact on other clearance pathways and physiology in general. Paper II "The kidneys play an important role in the clearance of rFVIIa in rats" describes the establishment, validation and use of an in vivo model for assessment of renal clearance. The model employed was a rat nephrectomy model and the compounds investigated were inulin and rFVIIa. General physiology was assumed to be close to normal as rectal temperature, oxygen saturation and pulse were within normal range during the pharmacokinetic studies. Nephrectomy significantly reduced clearance of rFVIIa and almost completely abolished clearance of inulin. Thus, it was concluded that the nephrectomy model could be used in assessment of the relative importance of the kidneys in the clearance of rFVIIa and the data obtained indicate that renal clearance accounts for 50% of total body clearance of rFVIIa. Paper III "The kidneys play a central role in the clearance of rhGH in rats" addresses renal clearance of rhGH. The in vivo model established in Paper II was used in a pharmacokinetic study of rhGH to assess the relative importance of the kidneys in the clearance of rhGH. The conclusion drawn based on this study was that the kidneys account for 90% of total body clearance of rhGH in anaesthetized rats. Furthermore, it was noted that anaesthesia reduced clearance of rhGH by 36% compared to non-anaesthetized rats. In conclusion, establishment, validation and use of a rat

  5. Short-term effects of liraglutide on kidney function and vasoactive hormones in type 2 diabetes

    Skov, J.; Pedersen, M.; Holst, Jens Juul;

    2016-01-01

    change local renal blood perfusion or oxygenation. The fractional excretion of lithium increased 14% (p = 0.01) and sodium clearance tended to increase (p = 0.06). Liraglutide increased diastolic and systolic blood pressure (3 and 6 mm Hg) and heart rate (3 min(-1) ) (all p < 0.05). Angiotensin II...... diabetes. Measurements included (51) Cr-EDTA plasma clearance estimated glomerular filtration rate (GFR) and MRI-based renal blood flow (RBF), tissue perfusion and - oxygenation. RESULTS: Liraglutide had no effect on GFR (95% CI -6.8 to 3.6 ml/min/1.73 m(2) ) or RBF (95% CI -39 to 30 ml/min) and did not...

  6. Effect of metabolic regulation on renal leakiness to dextran molecules in short-term insulin-dependent diabetics

    Parving, H H; Rutili, F; Granath, K;

    1979-01-01

    were normalized within one to three weeks of effective insulin treatment. This rapid reversibility can hardly be explained by the previously demonstrated enlargement in glomerular size and filtration surface area, since these alterations remain unchanged after more than one month of insulin treatment......Renal clearance of dextran of two ranges of molecular size and glomerular filtration rate (GFR, 51Cr-EDTA) were measured in seven short-term insulin-dependent diabetics (mean age 25 years). Measurements were carried out in the same patient during good and poor metabolic regulation (plasma glucose....... The metabolic regulation did not influence the size-selective properties of the glomerular wall. Therefore, we suggest that the dominating mechanism involved in the GFR and renal dextran clearance alterations is functional, viz. increased filtration pressure....

  7. Atrial natriuretic peptide and renal adaptation to contralateral nephrectomy in healthy man

    Kamper, A L; Pedersen, E B; Strandgaard, S; Holstein-Rathlou, N H; Leyssac, P P; Skaarup, P; Hemmingsen, L; Holm, J; Munck, O

    1991-01-01

    adaptation to acute reduction in renal mass. Glomerular and tubular function was studied by measurements of the clearances of 51Cr-EDTA, lithium, sodium, potassium, and albumin. ANP was 7.4 +/- 3.1 pmol l-1 (mean +/- SD) before Nx and 8.7 +/- 6.1 pmol l-1 at 5 days after Nx and remained at this level through...... clearance had risen from 13 +/- 2 ml min-1 before Nx to 20 +/- 7 ml min-1 (p less than 0.01), and sodium and water balance was normal. To conclude, plasma ANP, AII, Aldo and AVP do not appear to be responsible for the hyperfiltration and depression of fractional proximal sodium and water reabsorption...... observed in recently uninephrectomized man with normal sodium and water balance....

  8. Studies on diphosphonate kinetics. Pt. 1

    To improve the understanding of diphosphonate affinity to metabolically active bone, the underlying diphosphonate kinetics have been evaluated and compared to Cr-EDTA kinetics. MDP binds to plasma proteins, varying from 25% initially to approximately 70% after 24 h. The renal clearance of diphosphonate is found to be equal to Cr-EDTA clearance. Using simultaneous bolus injection of 99Tc-MDP and 51Cr-EDTA, it has been possible to obtain a coarse estimate of bone uptake of MDP. This uptake is found to correlate well with s-alkaline phosphatase, but since MDP binding to bone is reversible, the plasma elimination curve is not monoexponential. Therefore it has not been possible to describe the uptake of MDP in bone mathematically. (orig.)

  9. Clearance Laboratory - Capability and measurement sensitivity

    A new low-level Clearance Laboratory has been built at the Risoe-site. Building materials with a low content of naturally occurring radionuclides have been used. To minimize transport of radon gas from soil into the laboratory the foundation has been supplied with a membrane. The laboratory has been equipped with two high-efficiency germanium detectors. These detectors will be used for clearance measurements on the predicted amount of 15,000 - 18,000 tonnes of non-active or nearly non-active materials, which will originate from the decommissioning of all the nuclear facilities at the Risoe-site. They will be used also for clearance measurements on buildings and land. Objects and materials to be measured for clearance are placed on a rotation table that can carry up to one tonne and can rotate once a minute to simulate some averaging of inhomogeneously distributed activity. Sensitivity and background measurements reveal that measuring times of 20 - 50 minutes would normally be sufficient to detect radionuclide concentrations of only a small fraction of the nuclide-specific clearance levels with a sufficiently low uncertainty. Probability calculations of the measurement capacity of the Clearance Laboratory indicate that the mean value of the total measuring time for all materials that potentially can be cleared would be 13 years with a 95% probability of being less than 25 years. The mean value of the annual amount of materials that can be measured in the laboratory is 600 tonnes with a 95% probability of being less than 1,200 tonnes. If needed, there is room for additional measuring systems to increase the capacity of the laboratory. (au)

  10. Mucociliary clearance from the calf lung.

    C.D. Jones

    1983-01-01

    Mucociliary clearance rate constants for ten calves were obtained using Technetium 99m-sulphur colloid complex. The mean rate constant measured at the lung for all calves was 0.012 (+/- 0.009) min-1 (half-life 58 minutes). The clearance rate constants obtained from measurements made at the larynx were higher (0.02 +/- 0.007 min-1), although not significantly higher, than those determined from measurements taken at the lung. The constants can be used to predict the particle burden on the lungs...

  11. Effects of airborne pollutants on mucociliary clearance.

    Wolff, R K

    1986-01-01

    The mucociliary clearance system is a first line of defense against inhaled agents, and so its compromise can adversely affect health. The purpose of this paper is to provide a review of data on the effect of in vivo air pollutant exposures on the clearance of test particles from airways. Data from both animals and humans are compared whenever possible, so that estimates of human health effects may be made. Mechanisms of action are also discussed, presenting the view that for low level exposu...

  12. Nasal mucociliary clearance in patients with tracheostomy

    Yadav, S. P. S.; Janab, Khan Shariq; Singh, Jagat; Ranga, Rupender K.

    2003-01-01

    Nasal mucociliary clearance (NMC) time was estimated in 30 tracheostomized patients (24 males & 6 females) in the age group of 13–55 years which was 7.04±0.38 minutes: The patients suffering from nose and paranasal sinus disorders; taking drugs like bromhexine; undergoing radiotherapy and smokers were excluded from the study. The nasal mucociliary clearance in 30 age & sex matched healthy controls was 9.16±0.62 minutes. The NMC was found to he significantly lowered in patients with tracheosto...

  13. Impact of Glycation on Antibody Clearance

    Yang, Jane; Primack, Ronya; Frohn, Mike; Wang, Wei; Luan, Peng; Retter, Marc W.; Flynn, Gregory C.

    2014-01-01

    Glycation of therapeutic proteins occurs during mammalian cell culture expression and upon administration to patients. Since the chemical attachment of mannose or other sugars via a chemical linker has been shown to increase a protein’s clearance rate in mice through the mannose receptor, we explored the effect of mannose glycation on the clearance of an IgG in mice. An IgG decorated with high levels of mannose (~18 mol/mol protein) through glycation did not clear faster in mice than the unde...

  14. Glycerol clearance in alcoholic liver disease.

    Johnston, D G; Alberti, K. G.; Wright, R; Blain, P G

    1982-01-01

    Glycerol clearance was studied by a primed dose-constant infusion technique in 14 patients with alcoholic liver disease and six normal control subjects. Fasting blood glycerol concentrations were raised in the alcoholic subjects (0.09 +/- 0.01 vs 0.06 +/- 0.01 mumol/l, p less than 0.05) and glycerol clearance was impaired (24.5 +/- 1.9 vs 37.5 +/- 3.2 ml/kg/min, p less than 0.005). Endogenous production rate of glycerol and distribution space at steady state were similar in alcoholic and cont...

  15. Pharmacologic agents for mucus clearance in bronchiectasis.

    Nair, Girish B; Ilowite, Jonathan S

    2012-06-01

    There are no approved pharmacologic agents to enhance mucus clearance in non-cystic fibrosis (CF) bronchiectasis. Evidence supports the use of hyperosmolar agents in CF, and studies with inhaled mannitol and hypertonic saline are ongoing in bronchiectasis. N-acetylcysteine may act more as an antioxidant than a mucolytic in other lung diseases. Dornase α is beneficial to patients with CF, but is not useful in patients with non-CF bronchiectasis. Mucokinetic agents such as β-agonists have the potential to improve mucociliary clearance in normals and many disease states, but have not been adequately studied in patients with bronchiectasis. PMID:22640851

  16. Comparing taxi clearance input layouts for advancements in flight deck automation for surface operations

    Cheng, Lara W. S.

    Airport moving maps (AMMs) have been shown to decrease navigation errors, increase taxiing speed, and reduce workload when they depict airport layout, current aircraft position, and the cleared taxi route. However, current technologies are limited in their ability to depict the cleared taxi route due to the unavailability of datacomm or other means of electronically transmitting clearances from ATC to the flight deck. This study examined methods by which pilots can input ATC-issued taxi clearances to support taxi route depictions on the AMM. Sixteen general aviation (GA) pilots used a touchscreen monitor to input taxi clearances using two input layouts, softkeys and QWERTY, each with and without feedforward (graying out invalid inputs). QWERTY yielded more taxi route input errors than the softkeys layout. The presence of feedforward did not produce fewer taxi route input errors than in the non-feedforward condition. The QWERTY layout did reduce taxi clearance input times relative to the softkeys layout, but when feedforward was present this effect was observed only for the longer, 6-segment taxi clearances. It was observed that with the softkeys layout, feedforward reduced input times compared to non-feedforward but only for the 4-segment clearances. Feedforward did not support faster taxi clearance input times for the QWERTY layout. Based on the results and analyses of the present study, it is concluded that for taxi clearance inputs, (1) QWERTY remain the standard for alphanumeric inputs, and (2) feedforward be investigated further, with a focus on participant preference and performance of black-gray contrast of keys.

  17. Effects of lung volume on clearance of solutes from the air spaces of lungs

    Several investigators have shown that the clearance rate of aerosolized 99mTc-labeled diethylenetriamine pentaacetate (DTPA, mol wt = 492, radius = 0.6 nm) from the air spaces of the lungs of humans and experimental animals increases with lung volume. To further investigate this phenomenon we performed a compartmental analysis of the 2-h clearance of DTPA from the lungs of anesthetized sheep using a new method to more accurately correct for the effects of DTPA recirculation. This analysis showed that the DTPA clearance in eight sheep ventilated with zero end-expired pressure was best described by a one-compartment model with a clearance rate of 0.42 +/- 0.15%/min. Ventilating eight sheep with an end-expired pressure of 10 cmH2O throughout the study increased the end-expired volume 0.4 +/- 0.1 liter BTPS and created a clearance curve that was best described by a two-compartment model. In these sheep 56 +/- 16% of the DTPA cleared from the lungs at a rate of 7.9 +/- 2.9%/min. The remainder cleared at a rate similar to that measured in the sheep ventilated with zero end-expired pressure (0.35 +/- 0.18%/min). Additional control and lung inflation experiments were performed using /sup 99m/Tc-labeled human serum albumin (mol wt = 66,000, radius = 3.6 nm). In six control sheep ventilated with zero end-expired pressure the albumin clearance was best described by a one-compartment model with a clearance rate of 0.06 +/- 0.02%/min. The clearance rate in six sheep with increased lung volume was slightly larger (0.09 +/- 0.02, P less than 0.05) but was well described by a one-compartment model

  18. The effects of tangential radiotherapy on lung clearance in breast cancer patients

    Purpose: The aim of this study was to investigate the effects of tangential radiotherapy (RT) on lung clearance in the patients with breast cancer by using 99mTc-DTPA aerosol scintigraphy. Material and methods: Thirty-three female patients [non-smoker: 20, ex-smoker: 13] performed surgery and systemic chemotherapy for breast carcinoma [47±13 years] were included in the study. All patients underwent 99mTc-DTPA aerosol scintigraphy prior to RT (preRT), midway through RT (midRT) and after RT (postRT). Total dose was 50 Gy in modified radical mastectomy and 60 Gy in lumpectomy (2 Gy/fraction). Posterior dynamic images of lungs were obtained immediately after the inhalation of 99mTc-DTPA aerosol. Results: Pulmonary function tests were normal in three measurements for all cases. In the ex-smokers, there was no significant difference among preRT, midRT and postRT clearance values in both lungs. PreRT lung clearance in non-smoker group did not differ from that in ex-smokers. However, the lung clearance for non-smoker group showed significantly increase following RT. Conclusion: In this study, we observed that tangential radiotherapy caused an increase in the lung clearance in the cases of non-smokers even in non-irradiated lung, and that the effect of RT on lung clearance was closely depended on smoking habit before RT

  19. Dynamic analysis of planar mechanical systems with clearance joints using a new nonlinear contact force model

    Wang, Xupeng; Liu, Geng; Ma, Shangjun [Northwestern Polytechnical University, Xi' an (China)

    2016-04-15

    We investigated the dynamic behavior of planar mechanical systems with clearance joints. First, the contact effect in clearance joint was studied using a new nonlinear contact force model, and the rationality of this model was verified by the results of numerical simulations, which are based on a journal and bearing contact model. Then, the dynamic characteristics of a planar slider-crank mechanism with clearance were analyzed based on the new nonlinear contact force model, and the friction effect of clearance joint was also considered using modified Coulomb friction model. Finally, the numerical results of the influence of clearance size on the acceleration of slider are presented, and compared with the published experimental results. The numerical and experimental results show that the new nonlinear contact force model presented in this paper is an effective method to predict the dynamic behavior of planar mechanical system with clearance joints, and appears to be suitable for a wide range of impact situations, especially with low coefficient of restitution.

  20. Metabolism of oxycodone in human hepatocytes from different age groups and prediction of hepatic plasma clearance

    MiiaTurpeinen

    2012-01-01

    Full Text Available Oxycodone is commonly used to treat severe pain in adults and children. It is extensively metabolized in the liver in adults, but the maturation of metabolism is not well understood. Our aim was to study the metabolism of oxycodone in cryopreserved human hepatocytes from different age groups (3 days, 2 and 5 months, 4 years, adult pool and predict hepatic plasma clearance of oxycodone using these data. Oxycodone (0.1, 1 and 10 µM was incubated with hepatocytes for 4 hours, and 1 µM oxycodone also with CYP3A inhibitor ketoconazole (1 µM. Oxycodone and noroxycodone concentrations were determined at several time points with liquid chromatography-mass spectrometry. In vitro clearance of oxycodone was used to predict hepatic plasma clearance, using the well-stirred model and published physiological parameters. Noroxycodone was the major metabolite in all batches and ketoconazole inhibited the metabolism markedly in most cases. A clear correlation between in vitro oxycodone clearance and CYP3A4 activity was observed. The predicted hepatic plasma clearances were typically much lower than the published median total plasma clearance from pharmacokinetic studies. In general, this in vitro to in vivo extrapolation method provides valuable information on the maturation of oxycodone metabolism that can be utilized in the design of clinical pharmacokinetic studies in infants and young children.

  1. Effect of prior immobilization on muscular glucose clearance in resting and running rats

    Vissing, J; Ohkuwa, T; Ploug, Thorkil;

    1988-01-01

    In vitro studies have shown that prior disuse impairs the glucose clearance of red skeletal muscle because of a developed insensitivity to insulin. We studied whether an impaired glucose clearance is present in vivo in 42-h immobilized muscles of resting rats and, furthermore, whether the exercise......-induced increase in glucose clearance of red muscles is affected by prior immobilization. The 2-[3H]deoxy-D-glucose (2DG) bolus injection method was used to determine glucose clearance of individual muscles. At rest, glucose clearance was markedly impaired in rats with previously immobilized red muscles compared...... with nonimmobilized control rats (red gastrocnemius 0.46 +/- 0.02 vs. 0.99 +/- 0.08 and soleus 1.10 +/- 0.30 vs. 3.97 +/- 0.54 ml.min-1.100 g-1, P less than 0.005). During running (18 m/min), glucose clearance did not differ between muscles in previously immobilized and control rats. Insulin levels...

  2. The Swedish nuclear industry way to approach higher demands on characterisation prior to clearance

    : 'Introduction/background' 'Legal framework', 'characterisation and categorisation', 'the clearance process', 'laboration' (practical work) and group discussions, 'measurement methods', and 'documents and quality assurance'. Even though only one block out of seven is named 'characterisation and categorisation' this topic is an essential part in all blocks from different perspectives. Robust characterisation of materials, waste and the facility itself as well as a focus on traceability and record keeping saves a lot of money in all stages of the clearance process but especially the decommissioning phase. A proper characterization of materials, waste and the facility itself as well as focus on traceability and record keeping saves a lot of money in all stages of the clearance process but especially the decommissioning phase. (authors)

  3. 次氯酸钠冲洗方式、温度和冲洗时间影响根管玷污层的清除效果%Flushing methods, temperature and flushing time of sodium hypochlorite affect the clearance effect on the smear layer of root canal

    后岷红; 陈敏; 李蕾; 张沙沙; 周冬艳; 吴丽更

    2015-01-01

    背景:根管预备中,次氯酸钠根管冲洗液清除玷污层的效果与冲洗液接触时间和面积、冲洗液的量、冲洗液温度、冲洗液浓度、冲洗方式等有关。目的:观察在不同冲洗方式、冲洗温度和冲洗时间下,3%次氯酸钠对根管玷污层的清除效果。方法:收集离体人单根前牙180颗,均采用机动ProTaper进行根管预备,以3%次氯酸钠冲洗根管,根据冲洗方式将其随机均分为根管主动清洗组、被动超声荡洗组和侧方开口冲洗针组3大组,再根据冲洗温度和每更换一根锉后的冲洗时间分别将每大组随机均分为6小组,分别为20℃30 s组、20℃60 s组、37℃30 s组、37℃60 s、60℃30 s组和60℃60 s组。扫描电镜观察各组根管玷污层清除效果。结果与结论:根管主动清洗组玷污层的总体清除效果优于被动超声荡洗组与侧方开口冲洗针组(P <0.05)。每组组内,在时间一定的情况下,60℃组的玷污层清除效果优于37℃组、20℃组(P <0.05);在温度一定的情况下,60 s组的玷污层清除效果优于30 s组(P <0.05);根冠1/3区的玷污层清除效果优于根中1/3区、根尖1/3区(P <0.05)。说明以根管主动清洗方式,采用60℃的3%次氯酸钠清洗60 s清除玷污层的效果最好。%BACKGROUND:In root canal preparation, the clearance effect of sodium hypochlorite for root canal irrigation on the smear layer is associated with the contact time and contact area of irrigation fluid, the amount of irrigation fluid, irrigation fluid temperature, irrigation fluid concentration, flushing methods and so on. OBJECTIVE:To investigate the clearance effect of 3% sodium hypochlorite on the smear layer of root canal under different flushing methods, flushing temperature and flushing time. METHODS:Totaly 180 isolated front teeth with single root were colected and root canal preparation was conducted using motorized ProTaper. The root canal was

  4. 32 CFR 154.16 - Security clearance.

    2010-07-01

    ..., such as guards, emergency service personnel, firemen, doctors, nurses, police, ambulance drivers, or... shall be accomplished in accordance with 32 CFR part 159. The investigative requirement shall be the... be processed for a security clearance in accordance with 32 CFR part 353 and the provisions of...

  5. Uptake and clearance of uranium by misgurnus

    The author studied the bioconcentration and clearance of uranium in misgurnus and determined bioconcentration factors (BCF) as well as uptake and depuration rate constants. The test was performed under semi-static conditions. The depuration of uranium was best described by a two-compartment first order kinetic model

  6. Clearance of seborrhoeic keratoses with topical dobesilate

    Cuevas, Pedro; Angulo, Javier; Salgüero, Irene; Giménez-Gallego, Guillermo

    2012-01-01

    A patient with two seborrhoeic keratoses in the face received a single daily application of dobesilate cream during 6 months. Dobesilate achieved complete clearance of the seborrhoeic keratosis lesions with good cosmoses, suggesting that this compound is a safe and efficient candidate in the treatment of seborrhoeic keratoses.

  7. 30 CFR 57.11008 - Restricted clearance.

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Restricted clearance. 57.11008 Section 57.11008 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Travelways and Escapeways Travelways-Surface and Underground §...

  8. 30 CFR 57.7018 - Hand clearance.

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Hand clearance. 57.7018 Section 57.7018 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling-Surface Only § 57.7018...

  9. 30 CFR 57.7028 - Hand clearance.

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Hand clearance. 57.7028 Section 57.7028 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling-Underground Only § 57.7028...

  10. 30 CFR 57.11010 - Stairstep clearance.

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Stairstep clearance. 57.11010 Section 57.11010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Travelways and Escapeways Travelways-Surface and Underground...

  11. Clearance measurements on a hot cell building

    A former hot-cell facility of Siemens AG, in which dose rates in excess of 99 Sv were still prevailing in 1999, was decontaminated and subjected, except for the basement, to radiological clearance measurements. The authorities released the building for demolition in November 2004. Demolition of the upper stories of the building was started immediately afterwards using conventional techniques. For decontamination, the actual cells themselves - rooms with one-meter-thick concrete walls - had been dismantled using diamond saws and the resulting concrete blocks sent off-site for further processing. Contamination was removed from the remaining ceilings, walls and floors by knocking off the plaster and milling away the screed. Material samples were taken to confirm that decontamination had been successful. It was only then that the actual clearance measurements began. The individual rooms were grouped together into logically arranged ''clearance steps'' to simplify documentation. Most of the measurements were performed by in-situ gamma spectroscopy, with and without collimation. In addition, numerous material specimens were removed, direct surface measurements performed using contamination monitors, and wipe tests carried out. Records were made of all measurements and sorted according to clearance steps before being submitted to the competent authorities as an application for release from regulatory control. After the authorities had taken their own verification measurements they issued their approval for release. (orig.)

  12. Tracheobronchial clearance studies in the guinea pig

    Tracheobronchial clearance in guinea pigs exposed to relatively monodisperse aerosols was studied. Two new techniques were developed which enabled tagging of polystyrene particles with 198Au and with a fluorescent dye. A procedure was also developed to generate polystyrene particles with a vibrating orifice generator. Seventy animals were exposed via inhalation to relatively monodisperse polystyrene aerosols. Following exposure, animals were radioactively counted at regular intervals, sacrificed at predetermined times, and the lungs were removed, inflated to a standard pressure, frozen in liquid nitrogen, and freeze-dried. The freeze-dried lungs were sectioned completely, examined with a fluorescent microscope, and measurements were made of airway diameters in which particles were found. The results indicated a significant penetration of particles to the distal bronchioles and air spaces for 7.9 μm (MMD) particles and a lesser, though still significant, penetration for 10.3 μm (MMD) particles. An anatomical model for guinea pig lung morphology was used to classify particular ranges of airway diameters into zones. These zones were used to specify a compartmental model for lung clearance and the experimental particle distributions were categorized using this model. Equations were then developed describing the compartmental clearance. Rate constants were then obtained and used to predict airway transport rates in specific lung generations.The predicted transport rates ranged from approximately 0.001 mm/min in the distal bronchioles to approximately 8 mm/min in the trachea. These values agree with previous models for airway transport rates, and are consistent with experimental determinations of tracheal transport rates. Transit times were calculated and the results indicate a 24 hr clearance time for tracheobronchial clearance in the guinea pig

  13. 19 CFR 122.26 - Entry and clearance.

    2010-04-01

    ... AIR COMMERCE REGULATIONS Private Aircraft § 122.26 Entry and clearance. Private aircraft, as defined... information as set forth in § 122.22(c), and grants electronic clearance via electronic mail or telephone....

  14. Standardizing the measurement of parasite clearance in falciparum malaria: the parasite clearance estimator

    Flegg Jennifer A; Guerin Philippe J; White Nicholas J; Stepniewska Kasia

    2011-01-01

    Abstract Background A significant reduction in parasite clearance rates following artesunate treatment of falciparum malaria, and increased failure rates following artemisinin combination treatments (ACT), signaled emergent artemisinin resistance in Western Cambodia. Accurate measurement of parasite clearance is therefore essential to assess the spread of artemisinin resistance in Plasmodium falciparum. The slope of the log-parasitaemia versus time relationship is considered to be the most ro...

  15. Effect of inhibitors of prostaglandin synthesis on hepatic drug clearance.

    Feely, J; Wood, A. J.

    1983-01-01

    The effect of inhibition of prostaglandin synthesis on the systemic clearance of indocyanine green and antipyrine was studied in seven subjects. Antipyrine clearance was not altered by indomethacin suggesting that oxidative metabolism was not affected. Both aspirin and indomethacin decreased the clearance of indocyanine green presumably by reducing liver blood flow. These results suggest that an effect of inhibitors of prostaglandin synthesis on hepatic drug clearance is likely to be confined...

  16. Diminished creatinine clearance in anorexia nervosa: reversal with weight gain.

    Boag, F.; Weerakoon, J; Ginsburg, J; Havard, C W; Dandona, P

    1985-01-01

    To assess whether patients with anorexia nervosa have abnormalities in creatinine clearance, we measured plasma creatinine concentration, urinary creatinine excretion, and creatinine clearance in 10 patients with anorexia nervosa before and during treatment. Urinary creatinine excretion and creatinine clearance were diminished in all patients. Nine patients had significant decreases in their plasma creatinine and creatinine clearance was increased even when corrected for body weight and body ...

  17. The clearance of albumin microspheres from an intramuscular injection site

    Human serum albumin microspheres of three different diameters were radiolabelled with indium-111, and a suspension injected into rabbit thigh muscle. Clearance from the intramuscular site was monitored for 2 weeks using gamma scintigraphy. The clearance rates were compared with the injection site clearance of non-biodegradable polystyrene microspheres. (U.K.)

  18. 14 CFR 27.661 - Rotor blade clearance.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Rotor blade clearance. 27.661 Section 27... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Rotors § 27.661 Rotor blade clearance. There must be enough clearance between the rotor blades and other parts of the structure...

  19. 14 CFR 29.661 - Rotor blade clearance.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Rotor blade clearance. 29.661 Section 29... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Rotors § 29.661 Rotor blade clearance. There must be enough clearance between the rotor blades and other parts of the structure...

  20. 49 CFR Appendix F to Part 512 - OMB Clearance

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false OMB Clearance F Appendix F to Part 512 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION CONFIDENTIAL BUSINESS INFORMATION Pt. 512, App. F Appendix F to Part 512—OMB Clearance The OMB clearance...

  1. 46 CFR 56.75-10 - Joint clearance.

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Joint clearance. 56.75-10 Section 56.75-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND APPURTENANCES Brazing § 56.75-10 Joint clearance. (a) The clearance between surfaces to be joined shall be no larger than is necessary to insure...

  2. Guangzhou Customs Guide to Clearance of Import/Export Goods

    2009-01-01

    @@ Management of the Enterprises Granted for Convenient and Quick Customs Clearance 1.What is the enterprise granted for convenient and quick customs clearance? Customs General Administration and the Ministry of Foreign Trade and Economic Cooperation jointly issued policy measures to facilitate customs clearance in 2001 to further support the development of hightech industries.The enterprise .

  3. 14 CFR 1260.63 - Customs clearance and visas.

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Customs clearance and visas. 1260.63 Section 1260.63 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION GRANTS AND COOPERATIVE AGREEMENTS General Special Conditions § 1260.63 Customs clearance and visas. Customs Clearance and Visas...

  4. NONLINEAR DYNAMIC SIMULATION OF AN AXIALLY SLIDE-SPIN ROCKET FLEXIBLE SYSTEM WITH CLEARANCE

    Zhu Huailiang; Zhang Fuxiang

    2005-01-01

    A hybrid approach is presented to investigate the dynamic behavior of an axially slide-spin flexible rocket with nonlinear clearance. The equations of motion of the flexible rocket are derived based upon Euler-Bernoulli beam theory and Hamilton principle and the finite element method. The characteristics of clearance between the spinning rocket and launcher are considered to be piecewise linear. Numerical solution is developed by direct integration method and demonstrates the validity of the method. The coupled dynamic behavior of axial motion and transverse vibrations of rocket are analyzed, and the influences of axially moving acceleration, spin speed, linking stiffness of elastic "shoes", and the nonlinearity of clearance on the motion attitude of rocket are studied.

  5. Thickness and clearance visualization based on distance field of 3D objects

    Masatomo Inui

    2015-07-01

    Full Text Available This paper proposes a novel method for visualizing the thickness and clearance of 3D objects in a polyhedral representation. The proposed method uses the distance field of the objects in the visualization. A parallel algorithm is developed for constructing the distance field of polyhedral objects using the GPU. The distance between a voxel and the surface polygons of the model is computed many times in the distance field construction. Similar sets of polygons are usually selected as close polygons for close voxels. By using this spatial coherence, a parallel algorithm is designed to compute the distances between a cluster of close voxels and the polygons selected by the culling operation so that the fast shared memory mechanism of the GPU can be fully utilized. The thickness/clearance of the objects is visualized by distributing points on the visible surfaces of the objects and painting them with a unique color corresponding to the thickness/clearance values at those points. A modified ray casting method is developed for computing the thickness/clearance using the distance field of the objects. A system based on these algorithms can compute the distance field of complex objects within a few minutes for most cases. After the distance field construction, thickness/clearance visualization at a near interactive rate is achieved.

  6. Mass transport in saturated porous media

    Equilibrium and kinetic sorption models were used to simulate the transport of reactive solutes, 85Sr and 51Cr-EDTA, through small-scale laboratory columns. The least squares fitting procedure was used to calculate the model parameters and to simulate experimental results. Parameters of equilibrium and kinetic models were also determined using time moments analysis. Both methods provide virtually identical estimates of the flow velocity and dispersion coefficient. There is, however, a difference in estimates of rate constants due to sensitivity of the moment calculation procedure to the tail of breakthrough curve. It was concluded that the application of both techniques ensures accuracy in parameter estimation. Equilibrium models based on linear and nonlinear isotherms as well as reversible first order and two-site kinetic models were used to simulate the observed 85Sr breakthrough curves. In view of a good agreement between measured results and those simulated using the two-site kinetic and equilibrium models it was concluded that the equilibrium model may be used for describing the radiostrontium behaviour. The application of two-site kinetic model for simulating 51Cr-EDTA breakthrough curve resulted in the excellent agreement between simulated and observed results. 23 refs

  7. Frequency and factors effecting non clearance of lower pole renal stones

    Renal stone disease is a major health hazard in Pakistan and extra-corporeal shockwave lithotripsy is one of comprehensive method used to treat these stones. The aim of this study is to determine the frequency of factors affecting the non-clearance of stone fragments of lower pole renal stone after extra corporeal shockwave lithotripsy. The study was done with the objective to determine the frequency the spatial anatomical factors which can influence the non-clearance of lower pole stone fragments after ESWL. Methods: One and nineteen (119) patients with lower pole renal stone less than 10 mm were subjected to maximum 3 sessions of extracorporeal shock wave lithotripsy. KUB radiographs, ultrasonography and intravenous urography were used as investigative tools for lower pole renal calyceal anatomy. X ray KUB and ultrasound were done after a week for clearance. Data was analysed with the help of SPSS version 10.0 and presented in the forms of tables and graphs. Results: There were 77 (64.71%) males and 42 (35.29%) females. Infundibulo-pelvic angle (IPA)>40 degree was present in 93 (78.15%), Infundibular length (IL) <22 mm in 107 (89.92%) and Infundibular width (IW) >4 mm was present in 100 (84.03%) patients. The frequency of stone non clearance was noted in 31 (26.05%). Infundibulo-pelvic angle (IPA)>40 degree (p=0.000), Infundibular length (IL)<22 mm (p=0.001) and Infundibular width (IW)>4 mm (p=0.046) were significant variables affecting stone clearance. Conclusion: The frequency of non-clearance of lower calyx of kidney stone is 26.05%. The clearance of fragments of the lower calyx kidney stones is affected by three spatial anatomical factors, i.e., Infundibulopelvic angle, Infundibular width and infundibular length. (author)

  8. Clearances of solid waste uranium by using gamma spectrometry

    Clearances of contaminated materials arising from desmantling or decommissioning must be provided with the result of measurement of radionuclide content in such materials. In this research, direct measurement of uranium in solid waste for a clearance requirement had been developed by using gamma spectrometric with HPGe detector. The measurement method was developed based on 1001 keV gamma energy of Pa-234m considering a self absorption, detector characteristic, background level factors. For validation purpose, this method was compared with a neutron activation analysis (NAA) techniques. Efficiency for 1001 keV of Pa-234m was 0,0991– 0,1369 cps/Bq on density of 0,51–1,81 g/cm3 with a minimum detectable level of 8–10 Bq/kg. This method was useful for high concentration of U-238 with a precision in acceptance criteria P < 1% and the gamma spectrometer showed a high performance with a value Zscore <1. (author)

  9. Dynamic clearance measure to evaluate locomotor and perceptuo-motor strategies used for obstacle circumvention in a virtual environment.

    Darekar, Anuja; Lamontagne, Anouk; Fung, Joyce

    2015-04-01

    Circumvention around an obstacle entails a dynamic interaction with the obstacle to maintain a safe clearance. We used a novel mathematical interpolation method based on the modified Shepard's method of Inverse Distance Weighting to compute dynamic clearance that reflected this interaction as well as minimal clearance. This proof-of-principle study included seven young healthy, four post-stroke and four healthy age-matched individuals. A virtual environment designed to assess obstacle circumvention was used to administer a locomotor (walking) and a perceptuo-motor (navigation with a joystick) task. In both tasks, participants were asked to navigate towards a target while avoiding collision with a moving obstacle that approached from either head-on, or 30° left or right. Among young individuals, dynamic clearance did not differ significantly between obstacle approach directions in both tasks. Post-stroke individuals maintained larger and smaller dynamic clearance during the locomotor and the perceptuo-motor task respectively as compared to age-matched controls. Dynamic clearance was larger than minimal distance from the obstacle irrespective of the group, task and obstacle approach direction. Also, in contrast to minimal distance, dynamic clearance can respond differently to different avoidance behaviors. Such a measure can be beneficial in contrasting obstacle avoidance behaviors in different populations with mobility problems. PMID:25682376

  10. The kidneys play an important role in the clearance of rFVIIa in rats

    Vestergaard, Bill; Appa, Rupa S.; Lykkesfeldt, Jens; Agersø, Henrik

    2014-01-01

    study was to evaluate the importance of the kidneys in the clearance process of rFVIIa after iv administration to rats using a nephrectomy model. MATERIALS AND METHODS: A nephrectomized rat model was established and validated using inulin, a compound primarily cleared by the kidneys, as a test substance...... use of mixed effects methods, where a pharmacokinetic model was used to simultaneously model all data from healthy, sham operated, and nephrectomized rats. RESULTS: Nephrectomized animals showed stable rectal temperature, SpO2 and pulse and as expected, clearance of inulin was essentially abolished...

  11. Numerical simulation of tip clearance flow passive control in axial turbine

    Li, Wei; Qiao, Wei-Yang; Xu, Kai-Fu; Luo, Hua-Ling

    2008-06-01

    This paper focuses on the effects of five different passive turbine tip clearance flow control methods on the tip clearance flow physics, which consists of a partial suction side squealer tip, a double squealer tip, a pressure side tip shelf with inclined squealer tip on a double squealer tip, a tip platform extension edge in pressure side and in suction side respectively. A pressure-correction based, 3D Reynolds-averaged Navier-Stokes equations CFD code with Reynolds Stress Model was adopted. The variable specific heat was considered. The detailed tip clearance flow field with different squealer rims was described with the streamline and the velocity vector. Accordingly, the mechanisms of five passive controls were elucidated; the effects of the passive controls on turbine efficiency and tip clearance flow field were illuminated. The results showed that the secondary flow loss near the outer casing including the tip leakage losses and the passage vortex losses could be reduced in all the five passive control methods. The turbine efficiency could be increased via the rational passive turbine tip clearance flow control. The Improved PS Squealer had the best effect on turbine efficiency, and the efficiency increased by 0.215%.

  12. Clearance of a Mucus Plug

    Bian, Shiyao; Zheng, Ying; Grotberg, James B.

    2008-11-01

    Mucus plugging may occur in pulmonary airways in asthma, chronic obstructive pulmonary disease (COPD) and cystic fibrosis. How to clear the mucus plug is essential and of fundamental importance. Mucus is known to have a yield stress and a mucus plug behaves like a solid plug when the applied stresses are below its yield stress τy. When the local stresses reaches τy, the plug starts to move and can be cleared out of the lung. It is then of great importance to examine how the mucus plug deforms and what is the minimum pressure required to initiate its movement. The present study used the finite element method (FEM) to study the stress distribution and deformation of a solid mucus plug under different pressure loads using ANSYS software. The maximum shear stress is found to occur near the rear transition region of the plug, which can lead to local yielding and flow. The critical pressure increases linearly with the plug length and asymptotes when the plug length is larger than the half channel width. Experimentally a mucus simulant is used to study the process of plug deformation and critical pressure difference required for the plug to propagate. Consistently, the fracture is observed to start at the rear transition region where the plug core connects the films. However, the critical pressure is observed to be dependent on not only the plug length but also the interfacial shape.

  13. Pulmonary clearance of vasoactive intestinal peptide.

    Barrowcliffe, M P; Morice, A; Jones, J G; Sever, P S

    1986-01-01

    Vasoactive intestinal peptide causes bronchodilatation when given intravenously but is less effective in both animals and man when given by inhalation. This difference may be due to poor transit of the peptide across the bronchial epithelium. To test this hypothesis pulmonary clearance of radiolabelled vasoactive intestinal peptide was measured in Sprague Dawley rats and compared with that of pertechnetate (TcO4-) and diethylene triamine pentaacetate (DTPA). Despite a molecular weight (MW) of...

  14. Bomb strike experiment for mine clearance operations

    Ray, Gregory P.

    2006-01-01

    The Bomb Strike Experiment for Mine Countermeasure Operations, currently sponsored through the Office of Naval Research mine impact burial prediction project, is part of a multi-year, comprehensive effort aimed at enhancing the Navyâ s fleet naval mine clearance capability and success. The investigation discussed in this paper examines the experimental and theoretical characteristics of a rigid body falling through the air, water, and sediment column at high speed. Several experiments were ...

  15. Stereoselective renal clearance of pindolol in humans.

    Hsyu, P H; Giacomini, K M

    1985-01-01

    In this study, pindolol, a beta-adrenoceptor blocking agent marketed as a racemic mixture, was used as a model compound to investigate stereoselective renal clearance of organic cations in human beings. Six normal subjects received an oral dose of 20 mg racemic pindolol. Heart rate and blood pressure were measured throughout the study. A stereospecific high performance liquid chromatographic procedure was used to quantitate the concentrations of d- and l-pindolol in plasma and urine. Renal cl...

  16. Antipyrine clearance during occupational exposure to styrene.

    Døssing, M

    1983-01-01

    Animal experiments have indicated that styrene, which is a widely used organic solvent, may induce the microsomal enzyme function of the liver. Thirteen workers with long-term exposure to styrene in a polyester plant were investigated. They worked at air concentrations about the maximal allowed time-weighted average concentration of styrene in most Western countries (50 ppm). The clearance of antipyrine was determined from saliva concentrations before and after three weeks free of exposure an...

  17. Clearance of bronchial secretions after major surgery

    Leur, Johannes Peter van de

    2005-01-01

    Minimally invasive airway suctioning is equally effective as routine endotracheal suctioning but results in less suction related adverse events, less recollection of suctioning and less stress. Thus, although it cannot be employed in all situations, minimally invasive airway suctioning should be the “default setting” for mucus clearance in ICU-patients. Special suction catheters should be marketed that do not pass the distal tip of the endotracheal tube. Alternatively, standard catheters can ...

  18. Promoter clearance by RNA polymerase II

    Luse, Donal S.

    2012-01-01

    Many changes must occur to the RNA polymerase II (pol II) transcription complex as it makes the transition from initiation into transcript elongation. During this intermediate phase of transcription, contact with initiation factors is lost and stable association with the nascent transcript is established. These changes collectively comprise promoter clearance. Once the transcript elongation complex has reached a point where its properties are indistinguishable from those of complexes with muc...

  19. Hemodialysis clearance of intravenously administered ribavirin.

    Kramer, T H; Gaar, G G; Ray, C G; Minnich, L; Copeland, J G; Connor, J. D.

    1990-01-01

    A patient with an implanted artificial heart, acute, anuric renal failure, and disseminated influenza virus type A infection received intravenous ribavirin. Drug elimination by hemodialysis was measured. Plasma dialysis clearance averaged 93.9 +/- 8.6 ml/min. The maximum amount of ribavirin removed from the body during one period of hemodialysis was 79.1 mg. Ribavirin is not removed in important quantities by hemodialysis.

  20. Immune clearance of highly pathogenic SIV infection

    Hansen, Scott G.; Piatak, Michael; Ventura, Abigail B.; Hughes, Colette M.; Gilbride, Roxanne M.; Ford, Julia C.; Oswald, Kelli; Shoemaker, Rebecca; Li, Yuan; Matthew S. Lewis; Gilliam, Awbrey N.; Xu, Guangwu; Whizin, Nathan; Burwitz, Benjamin J; Planer, Shannon L.

    2013-01-01

    Established infections with the human and simian immunodeficiency viruses (HIV, SIV) are thought to be permanent with even the most effective immune responses and anti-retroviral therapies (ART) only able to control, but not clear, these infections 1–4 . Whether the residual virus that maintains these infections is vulnerable to clearance is a question of central importance to the future management of millions of HIV-infected individuals. We recently reported that ~50% of rhesus macaques (RM)...

  1. ADSORBENTS USED IN THE CLEARANCE OF ENDOTOXIN

    YU Mei; LIU Tao; Hou Guanghui; YUAN Zhi

    2003-01-01

    A series of modified poly (methyl methacrylate, PMMA) resins were prepared and compared their adsorption abilities to endotoxin. The results showed that adsorbents, which were grafted with tertiary amine and long spacing arms, had the best adsorption capacities and good blood compatibility, It is hopeful to be used as adsorbent in hemoperfusion for clinical clearance of endotoxin. The influence of original concentration of endotoxin on adsorption and the adsorption mechanism were also investigated.

  2. Bronchoscintigraphy and pulmonary clearance of {sup 99{sup m}}Tc-albumin colloid in study of mucociliary clearance

    Mortensen, Jann

    1998-12-31

    A radioaerosol based method for measuring MC was introduced. It included an inhalation protocol that resulted in a predominant deposition of radioaerosol in the central bronchi and two simple procedures of evaluation: 1) a visual semi-quantitative bronchoscintigraphic analysis, and 2) a quantitative analysis of the retention of the radioactivity at different points after the inhalation. The results showed that bronchoscintigraphy was a simple technique that may be used to visualize a stimulation of mucociliary transport in the central airways of individuals that do not suffer from too much mucus hypersecretion. Comparison of the MC between individuals, however, should preferably be performed by the method of quantitative analysis of the radioactivity disappearance. A change of MC was found to be one of the first detectable effects on lung function of tobacco smoking. It could be effectively detected by measurement of radioaerosol clearance both by bronchoscintigraphy and simple quantification of the MC. The MC may be either acutely enhanced, reduced or not changed by smoking. Long-term smoking impairs MC. The enhancement of MC by {beta}{sub 2}-agonists was very limited in most patients with CF. In the hope of increasing mucus transport in patients with CF, these are treated with various chest physiotherapy techniques. The radioaerosol based method of measurement of MC could assess mucus clearance by chest physiotherapy and cough. (au) 141 refs.

  3. Determination of the renal clearance by reconstruction of the whole-body retention curve from the results of subsequent measurements

    Starting from routine renal clearance measurements in a partially shielded whole-body counter, generally applicable algorithms were developed empirically which permit the reconstruction of the total course of retention up to 28 min p.i. from e.g. the 12 min and 24 min values only. By formal differentiation the instanteneous slope of the decline in retention and thus the renal clearance can be calculated employing the whole-body counting principle. Integration yields the possibility of subtracting background from renograms to calculate single renal clearances. The method offers advantages in cases of reduced measurement geometry and/or low count rates. (orig.)

  4. Establishing exemption and clearance criteria by the regulatory authority

    This Project work discusses the relationship between the concepts of exemption and clearance, and their practical use in the overall scheme of regulatory control of practices. It also discusses how exemptions and clearance is established and the scope of its applications for regulatory control. The concept of general clearance levels for any type of material and any possible pathway of disposal is also introduced in this work. Guidance of the Group of Experts establishing scenarios for general clearance, parameter values, and a nuclide-specific list of calculated clearance levels is also presented. Regulatory authorities are required to develop guidance on exemption and clearance levels to assist licensees and registrants to know which practices and sources within practices are exempted from regulatory control and those to be cleared from further controls. Exemption and clearance levels are tools for assisting the Regulatory Authority to optimize the use of resources. (author)

  5. Initial effect of enalapril on kidney function in patients with moderate to severe chronic nephropathy

    Kamper, A L; Thomsen, H S; Nielsen, S L; Strandgaard, S

    1990-01-01

    Angiotensin converting enzyme (ACE) inhibitors has been suggested to halt the progression of chronic renal failure. As the initial step of a controlled trial of this hypothesis, it was investigated whether start of enalapril in patients with severe chronic nephropathy might cause a critical fall in...... their renal function. Thirty-one patients were studied, 26 on chronic antihypertensive treatment with drugs other than ACE inhibitors and 5 untreated normotensive. 51Cr-EDTA plasma clearance and renal technetium-99m dimercaptosuccinic acid (99mTc-DMSA) scintigraphy were made before and 24 h after start...... scintigrams showed no intrarenal activity defects. In conclusion, enalapril caused a fall in GFR, which was clinically acceptable in most of the patients....

  6. Renal uptake of dimercaptosuccinic acid and glomerular filtration rate in chronic nephropathy at angiotensin converting enzyme inhibition

    Kamper, A L; Thomsen, H S; Nielsen, S L; Strandgaard, S

    1990-01-01

    function. Scintigrams of the kidneys showed an unaltered distribution of DMSA during treatment. GFR estimated by 51Cr-EDTA plasma clearance fell by 14% (P less than 0.01), but renal uptake of 99mTc-DMSA increased by 10% (P less than 0.01). It is concluded that DMSA in chronic renal failure is mainly taken......Glomerular filtration rate (GFR) and renal uptake of dimercaptosuccinic acid (DMSA) were measured in 31 patients with progressive chronic nephropathy before and immediately after the start of treatment with angiotensin converting enzyme (ACE) inhibitor in order to control adverse effects on kidney...... up by the tubular cells from the peritubular capillaries since the uptake was unaffected by the acute decrease in GFR....

  7. Effect of increases in lung volume on clearance of aerosolized solute from human lungs

    To study the effect of increases in lung volume on solute uptake, we measured clearance of /sup 99m/Tc-diethylenetriaminepentaacetic acid (Tc-DTPA) at different lung volumes in 19 healthy humans. Seven subjects inhaled aerosols (1 micron activity median aerodynamic diam) at ambient pressure; clearance and functional residual capacity (FRC) were measured at ambient pressure (control) and at increased lung volume produced by positive pressure [12 cmH2O continuous positive airway pressure (CPAP)] or negative pressure (voluntary breathing). Six different subjects inhaled aerosol at ambient pressure; clearance and FRC were measured at ambient pressure and CPAP of 6, 12, and 18 cmH2O pressure. Six additional subjects inhaled aerosol at ambient pressure or at CPAP of 12 cmH2O; clearance and FRC were determined at CPAP of 12 cmH2O. According to the results, Tc-DTPA clearance from human lungs is accelerated exponentially by increases in lung volume, this effect occurs whether lung volume is increased by positive or negative pressure breathing, and the effect is the same whether lung volume is increased during or after aerosol administration. The effect of lung volume must be recognized when interpreting the results of this method

  8. Effect of increases in lung volume on clearance of aerosolized solute from human lungs

    Marks, J.D.; Luce, J.M.; Lazar, N.M.; Wu, J.N.; Lipavsky, A.; Murray, J.F.

    1985-10-01

    To study the effect of increases in lung volume on solute uptake, we measured clearance of /sup 99m/Tc-diethylenetriaminepentaacetic acid (Tc-DTPA) at different lung volumes in 19 healthy humans. Seven subjects inhaled aerosols (1 micron activity median aerodynamic diam) at ambient pressure; clearance and functional residual capacity (FRC) were measured at ambient pressure (control) and at increased lung volume produced by positive pressure (12 cmH2O continuous positive airway pressure (CPAP)) or negative pressure (voluntary breathing). Six different subjects inhaled aerosol at ambient pressure; clearance and FRC were measured at ambient pressure and CPAP of 6, 12, and 18 cmH2O pressure. Six additional subjects inhaled aerosol at ambient pressure or at CPAP of 12 cmH2O; clearance and FRC were determined at CPAP of 12 cmH2O. According to the results, Tc-DTPA clearance from human lungs is accelerated exponentially by increases in lung volume, this effect occurs whether lung volume is increased by positive or negative pressure breathing, and the effect is the same whether lung volume is increased during or after aerosol administration. The effect of lung volume must be recognized when interpreting the results of this method.

  9. The influence of annular seal clearance to the critical speed of the multistage pump

    In the multistage pump of high head, pressure difference in two ends of annular seal clearance and rotor eccentric would produce the sealing fluid force, the effect of which can be expressed by a damping and stiffness coefficient. It has a great influence on the critical speed of the rotor system. In order to research the influence of the annular seal to the rotor system, this paper used CFD method to conduct the numerical simulation for the flow field of annular seal clearance. The radial and tangential forces were obtained to calculate the annular dynamic coefficients. Also dynamic coefficient were obtained by Matlab. The rotor system was modeled using ANSYS finite software and the critical speed with and without annular seal clearance were calculated. The result shows: annular seal's fluid field is under the comprehensive effect of pressure difference and rotor entrainment. Due to the huge pressure difference in front annular seal, fluid flows under pressure difference; the low pressure difference results in the more obvious effect on the clearance field in back annular seal. The first order critical speed increases greatly with the annular seal clearance; while the average growth rate of the second order critical speed is only 3.2%; the third and fourth critical speed decreases little. Based on the above result, the annular seal has great influence to the first order speed, while has little influence on the rest

  10. Intrinsic Clearance of Xenobiotic Chemicals by Liver Microsomes: Assessment of Trophic Magnification Potentials.

    Guomao, Zheng; Yi, Wan; Jianying, Hu

    2016-06-21

    The use of trophic magnification factors (TMFs) to characterize the bioaccumulation potentials of chemicals was encouraged; however, the method for the assessment of trophic magnification potentials is still lacking. We optimized the in vitro assays used for the measurement of intrinsic clearance in liver microsomes by incorporating benzo[a]pyrene (B(a)P) as a benchmark compound. The intrinsic clearance of 40 compounds was then measured in microsomes from fish (weevers) and birds (quail); the characteristics of the trophic transfer of these 40 compounds were previously investigated in an aquatic food web in Bohai in northern China. Chemicals that are biotransformed at a rate similar to or higher than that of B[a]P in the microsomes of both weevers and quail (in vitro intrinsic clearance values, CL; CL/CLB[a]P: 0.1 to 2.4) generally exhibited no significant trophic magnification or dilution in the food web (TMF ≈ 1 or 1). The in vitro intrinsic clearance values of the target chemicals were found to be consistent with their respective trophic transfer behavior in the aquatic food web. Significant negative correlations were also found between the TMFs and the intrinsic clearance values of all target chemicals obtained in microsomes from both weevers and quail. Multiple linear regression analysis showed that biotransformation rates (CL/CLB[a]P) are a more important factor compared with the lipophilicity of the chemicals (log Kow) in the assessment of the trophic magnification of chemicals in the aquatic food web. PMID:27152959

  11. Clearance of materials resulting from the use of radionuclides in medicine, industry and research

    It has long been recognized that the use of sources of radiation should be regulated. The recommended regulatory approach is based on a system of notification and authorization exemplified by the IAEA International Basic Safety Standards for Protection Against Ionizing Radiation and for the Safety of Radiation Sources (BSS). However, some types of radiation source do not meet to be subject to regulatory control because they can only give rise to trivial radiation hazards. Such sources may be exempted or cleared from the requirements of regulatory control. Exemption applies to radiation sources which do not enter the regulatory control regime, while clearance is relevant to radiation sources which were within the regulatory regime but can be released because they present an insignificant risk to health. It is the latter situation which is the subject of this publication. While the emphasis of the report is on providing guidance on the clearance process and on methods for determining clearance leaves, taking account of site specific factors as appropriate, a set of conservatively derived generic clearance levels is also presented. These are expected to be of considerable help to users of small quantities of radionuclides in laboratories and hospitals and their regulators. They can be used, taking due account of the associated notes of caution, as reference levels for determining when clearance is the appropriate option for disposing of the materials

  12. Long-term clearance from small airways in subjects with ciliary dysfunction

    Hjelte Lena

    2006-05-01

    Full Text Available Abstract The objective of this study was to investigate if long-term clearance from small airways is dependent on normal ciliary function. Six young adults with primary ciliary dyskinesia (PCD inhaled 111 Indium labelled Teflon particles of 4.2 μm geometric and 6.2 μm aerodynamic diameter with an extremely slow inhalation flow, 0.05 L/s. The inhalation method deposits particles mainly in the small conducting airways. Lung retention was measured immediately after inhalation and at four occasions up to 21 days after inhalation. Results were compared with data from ten healthy controls. For additional comparison three of the PCD subjects also inhaled the test particles with normal inhalation flow, 0.5 L/s, providing a more central deposition. The lung retention at 24 h in % of lung deposition (Ret24 was higher (p 24 with slow inhalation flow was 73.9 ± 1.9 % compared to 68.9 ± 7.5 % with normal inhalation flow in the three PCD subjects exposed twice. During day 7–21 the three PCD subjects exposed twice cleared 9 % with normal flow, probably representing predominantly alveolar clearance, compared to 19 % with slow inhalation flow, probably representing mainly small airway clearance. This study shows that despite ciliary dysfunction, clearance continues in the small airways beyond 24 h. There are apparently additional clearance mechanisms present in the small airways.

  13. Radionuclide quantification of oropharyngeal clearance with and without pharyngitis

    Robbins, P.S.; Siegel, J.A.; Maurer, A.H.; Schachtel, B.P.; Malmud, L.S.

    1984-01-01

    The purpose of this study was to evaluate a new radionuclide method for quantifying oropharyngeal clearance (C) in 10 otherwise normal patients with and without pharyngitis (PH). Patients with objective evidence of PH initially swallowed 10 ml of water mixed with 1 mCi Tc-99m sulfur colloid and then performed a dry swallow each 15 seconds. This was repeated 1-4 weeks later when there was no evidence of pharyngitis (NP). Images were acquired using a high sensitivity collimator for 0.1 sec/image for 30 sec and 15 sec/image for an additional 270 sec. Time activity curves generated from a region of interest over the oropharynx were fit to a biexponential function, C = Ae/sup -k/1/sup t/ + Be/sup -k/2/sup t/; where A and B are the percent of activity clearing with fast and slow components, k/sub 1/, and k/sub 2/, respectively, with half times 0.693/k/sub l,2/. The T1/2 for the slow component was reproducible for PH and NP. The fast component was slightly prolonged with PH, but not to statistical significance (p>.2). The authors conclude that a biexponential model of clearance may be used to quantify oropharyngeal function, for patients with normal and abnormal swallowing.

  14. Quantification of clearance and creep in acetabular wear measurements

    Gregory, Thomas; Vandenbussche, Eric

    2016-01-01

    Background This study aimed to measure femoral head penetration before occurrence of real wear, and to quantify the portions attributable respectively to clearance and plastic deformations in various acetabular designs. Methods We analyzed CT scans from 15 patients at ‘day five’ after total hip arthroplasty (THA). All patients received Exafit® femoral stems and 28 mm heads: 5 patients had cemented Durasul® all-PE cups, 5 patients had un-cemented Allofit® metal-backed cups, and 5 patients had un-cemented Stafit® dual-mobility cups. We also analyzed CT scans of samples of the three head-cup combinations to compare in vivo and in vitro measurements. Results The mean femoral head penetration measured on ‘day five’ was lower for all-PE cups (0.196 mm) than for metal-backed cups (0.551 mm) and dual-mobility cups (0.634 mm). Conclusions The present study indicates that isolated measurements of femoral head penetration include 0.15–0.46 mm of radial clearance and 0.05–0.27 mm of creep, and confirms that the majority of so-called bedding-in observed in the first post-operative months is not entirely due to wear. PMID:27162781

  15. Radioactive waste management: Review on clearance levels and acceptance criteria legislation, requirements and standards

    In 2011 the joint research project Metrology for Radioactive Waste Management (MetroRWM) of the European Metrology Research Programme (EMRP) started with a total duration of three years. Within this project, new metrological resources for the assessment of radioactive waste, including their calibration with new reference materials traceable to national standards will be developed. This paper gives a review on national, European and international strategies as basis for science-based metrological requirements in clearance and acceptance of radioactive waste. - Highlights: • Legislation, requirements and standards in radioactive waste management. • Strategies and methods to maintain the relevant clearance levels and acceptance criteria. • International, European and national activity levels and limits for exemption and clearance of radioactive waste. • Requirements for acceptance for storage and final disposal of radioactive waste. • Metrological requirements for radioactive waste characterisation

  16. Renogram evaluation using an equation of balance for clearance and transit time determination

    A method of [123I]hippuran (OIH) renogram evaluation is proposed, which delivers transition rates for total and split renal clearance. It is based on the reconstruction of the true kidney input, using an equation of balance and a two-compartment model assumption of OIH kinetics. Results are compared with clearance determinations using whole body principles and transit time determination by deconvolution. It is shown that the reconstructed true input corresponds to the plasma activity while the vascular volume of distribution corresponds to the blood

  17. Four hour creatinine clearance is better than plasma creatinine for monitoring renal function in critically ill patients

    Pickering, John W; Frampton, Christopher M; Walker, Robert J.; Shaw, Geoffrey M.; Endre, Zoltán H

    2012-01-01

    Introduction Acute kidney injury (AKI) diagnosis is based on an increase in plasma creatinine, which is a slowly changing surrogate of decreased glomerular filtration rate. We investigated whether serial creatinine clearance, a direct measure of the glomerular filtration rate, provided more timely and accurate information on renal function than serial plasma creatinine in critically ill patients. Methods Serial plasma creatinine and 4-hour creatinine clearance were measured 12-hourly for 24 h...

  18. Clearance and release from control - An international perspective

    This paper tries to give an overview of the clearance, or release from regulatory control, on an international scale, including some of those countries where clearance has become or is about to become vital for D and D. The emphasis lies on the impact of clearance, and in particular of differences between clearance levels of various countries, on D and D. Relevance of clearance for D and D of nuclear installations Clearance is an essential part of waste management (or more general, material management) in nuclear installations, and in particular during the decommissioning phase where waste streams continues to arise. Of course, the relevance of clearance in a particular country depends on a number of factors, like: availability of a final repository and its price; prevailing decommissioning strategy; number of nuclear installations reaching decommissioning phase. This small selection of reasons why clearance may be of varying importance for different countries may already suffice to illustrate why up to now clearance has been developed and implemented in quite different ways. If one thinks of additional reasons that may influence clearance, like politics, the public opinion, availability of funds etc., the situation becomes even more complex. It is, however safe to draw the conclusion that countries with a certain number of nuclear installations which have been or will soon be shut down or which are already in the decommissioning phase will need to implement provisions for clearance. This has indeed been the case with countries like the UK, Germany, the USA, Sweden, and a number of others. It is not essential for clearance levels to be exactly equal between various countries. They may differ as long as the difference is not too large, e.g. the values fall into the same order of magnitude. This is the reason why for example Germany has no problems with clearance levels which differ from the EU recommendation RP 122 partially adopted in a number of EU countries

  19. Investigations of renal clearance in nuclear medicine

    Comparative investigations of PAH- and inulin-clearance and results of investigations with J-131-hippurate and Cr-51-EDTA, which were performed by a partly screened whole body counter including measurements of activity retention of blood samples, are showing good correlation. If the radio-isotope nephrography is worked out together with the decreased retention curve, separate results of the function of both kidneys can be given. Modifications which were tried to analyze a small part of the retention curve instead of the whole body are inaccurate, if they are below 300 ml/min. (orig.)

  20. Carbamazepine Clearance and Seizure Stability during Pregnancy

    Johnson, Emily L.; Stowe, Zachary N.; Ritchie, James C; Newport, D. Jeffrey; Newman, Melanee L.; Knight, Bettina; Pennell, Page B

    2014-01-01

    The aims of this study were to characterize the alterations in total and free carbamazepine (CBZ) and total and free carbamazepine-epoxide (CBZ-EPO) clearances during pregnancy; to calculate the change in free fractions of CBZ and CBZ-EPO during pregnancy; and to determine whether seizure worsening is associated with a low ratio to non-pregnant baseline concentration of total or free CBZ or CBZ-EPO. Women on CBZ were enrolled before conception or during pregnancy in this prospective, observat...

  1. Biodistribution and clearance of instilled carbon nanotubes in rat lung

    Rogerieux Françoise

    2008-12-01

    Full Text Available Abstract Background Constituted only by carbon atoms, CNT are hydrophobic and hardly detectable in biological tissues. These properties make biokinetics and toxicology studies more complex. Methods We propose here a method to investigate the biopersistence of CNT in organism, based on detection of nickel, a metal present in the MWCNT we investigated. Results and conclusion Our results in rats that received MWCNT by intratracheal instillation, reveal that MWCNT can be eliminated and do not significantly cross the pulmonary barrier but are still present in lungs 6 months after a unique instillation. MWCNT structure was also showed to be chemically modified and cleaved in the lung. These results provide the first data of CNT biopersistence and clearance at 6 months after respiratory administration.

  2. Study of blade clearance effects on centrifugal pumps

    Hoshide, R. K.; Nielson, C. E.

    1972-01-01

    A program of analysis, design, fabrication, and testing has been conducted to develop and experimentally verify analytical models to predict the effects of impeller blade clearance on centrifugal pumps. The effect of tip clearance on pump efficiency, and the relationship between the head coefficient and torque loss with tip clearance was established. Analysis were performed to determine the cost variation in design, manufacture, and test that would occur between unshrouded and shrouded impellers. An impeller, representative of typical rocket engine impellers, was modified by removing its front shroud to permit variation of its blade clearances. It was tested in water with special instrumentation to provide measurements of blade surface pressures during operation. Pump performance data were obtained from tests at various impeller tip clearances. Blade pressure data were obtained at the nominal tip clearance. Comparisons of predicted and measured data are given.

  3. Comparison of measurements of plasma clearance of Mebrofenine and of indocyanine green; Comparaison des mesures de clairance plasmatique de la mebrofenine et du vert d`indocyanine

    Maurel, G.; Coutris, G. [Service Central de Medecine Nucleaire, Hopital Saint Antoine (France); Vaubourdolle, M. [Laboratoire de Biochimie A, Hopital Saint Antoine (France); Attal, P.; Patureau, R.; Tabsoba, Th. [Service Central de Medecine Nucleaire, Hopital Saint Antoine (France); Mensch, B. [Laboratoire de Biophysique, CHU Saint Antoine (France); Askienazy, Pr.S. [Service Central de Medecine Nucleaire, Hopital Saint Antoine (France)

    1997-12-31

    The importance of clearance measurements in evaluating renal or hepatic function needs not further demonstration. The isotopic methods were proved in renal exploration but their utilization in exploration of hepato-biliary function needs to be evaluated. In this work we have compared the measurement of plasma clearance by Mebrofenine, a radiopharmaceutical of specifically hepatic elimination, with the reference method, the clearance of indocyanine green. On the basis of scintigraphic data from 23 patients who benefited by a hepato-biliary exploration by Mebrofenine-{sup 99m}Tc for pre-surgery account and surveillance, we have determined the plasma clearance of this radiopharmaceutical. The method makes use of the curve of normalized cardiac activity by a blood sampling, taken 60 minutes after injection. The measurement of the clearance of indocyanine green was effected within a delay inferior to 1 month from the moment of biliary scintigraphy. The average clearance of Mebrofenine-{sup 99m}Tc is of 553 ml/min for 1.73 m{sup 2} of corporal surface (typical interval is 374 ml/min), the value of indocyanine green is of 450 ml/min (typical interval is 229 ml/min). The two measurements of clearance are correlated (p = 0.05). In conclusion, the measurement of clearance by Mebrofenine-{sup 99m} appears to be adapted to the evaluation of hepato-biliary function

  4. Biodistribution and Clearance Test 186Re(V) - DMS A in Normal White Rats (A Strain of Wistar)

    186Re(V) - DMS A is a β-emitting radiopharmaceutical for medullary thyroid carcinoma therapy. Biodistribution and clearance tests of 186Re(V) - Dmsa was done by wet destruction method using concentrate liquid of nitric acid in the organ, blood and urine of normal white rats. Biodistribution test showed a smaller accumulation of activity per gram normal organ of the thyroid (1.80 ± 0.58% at 30 minutes after intravenous injection. The higher accumulation of activity was apparent in kidney, and then followed by lung and liver. Clearance test of 186Re(V) - DMS A showed a short enough blood clearance time with 2.75 ± 0.30% of the activity remained in the blood at 30 minutes after injection. The urine clearance of 186Re(V) - DMS A with in 24 hours after injection was 2.29 ± 0.91% of the activity per ml urine

  5. EC and IAEA guidance on exemption and clearance levels and implications on clearance in Germany

    Thierfeldt, S.; Woerlen, S.; Barthel, R. [Brenk Systemplanung GmbH, Aachen (Germany)

    2009-07-01

    The current EURATOM Basic Safety Standards (BSS), the Council Directive 96/29/EURATOM of 13 May 1996 [1], contain general provisions for clearance in Article 5 but no specific clearance levels (in terms of nuclide specific mass or surface related activity values). A set of levels has been developed in IAEA Safety Guide RSG-1.7 [5] (for details on the derivation see IAEA Safety Report 44 [6]) as general clearance levels and exemption values for large quantities for inclusion in the IAEA BSS [4]. This set of values has been proposed by the European Commission (EC) as an internationally harmonised set of clearance levels that could be incorporated into the BSS. Furthermore, the EC has proposed to use this set of values also as a new set of exemption values, replacing the current set of mass related exemption values of Annex I Table A Column 3 of the BSS. It was, however, decided that the technical background and further details of the derivation of the set of values should be evaluated before actually incorporating these values into the EURATOM BSS. Therefore, a study was commissioned by the European Commission, DG TREN, and has been prepared by Brenk Systemplanung GmbH in 2008 [7]. This study provides a basis for a decision whether the levels of RS-G-1.7 could be used as clearance levels for unconditional clearance and as a replacement for mass related exemption values in the BSS. It also compares the background and approach of the relevant documents (RS-G-1.7 and SR 44 of the IAEA and RP 122 part I [2] of the European Commission) and the way in which clearance levels have been derived (analysis of scenarios, parameter values and calculation codes). The comparison is performed and evaluated on a nuclide-specific basis, and conclusions are drawn where further evaluation of the values of RS-G-1.7 would be needed. In a second part, the study evaluates and discusses implications for practices not requiring reporting or authorisation under the current exemption values

  6. Clearance of materials, buildings and land with low content of radioactive materials. Methodology and documentation; Frigivelse af materialer og omraeder med lavt aktivitetsindhold. Metodebeskrivelse og dokumentation

    Hedemann Jensen, P.; Lauridsen, B.; Soegaard-Hansen, J.; Warming, L

    2003-06-01

    The concepts and methods of clearance of materials originating from the decommissioning af the nuclear facilities at Risoe National Laboratory are described as well as procedures for clearance of buildings and land. The recommendations from international organisations as well as national regulation on clearance are presented. Methods for characterisation and separation of waste being candidate for clearance are presented.Di .erent methodologies for determining the content of radionuclides in candidate waste for clearance are discussed,and the need for and construction of a low-level laboratory for activity analyses in both bulky and less bulky subjects is described. Laboratory analyses, documentation of results and education of health physics personnel is presented. (au)

  7. Immune modulation with sulfasalazine attenuates immunopathogenesis but enhances macrophage-mediated fungal clearance during Pneumocystis pneumonia.

    Jing Wang

    Full Text Available Although T cells are critical for host defense against respiratory fungal infections, they also contribute to the immunopathogenesis of Pneumocystis pneumonia (PcP. However, the precise downstream effector mechanisms by which T cells mediate these diverse processes are undefined. In the current study the effects of immune modulation with sulfasalazine were evaluated in a mouse model of PcP-related Immune Reconstitution Inflammatory Syndrome (PcP-IRIS. Recovery of T cell-mediated immunity in Pneumocystis-infected immunodeficient mice restored host defense, but also initiated the marked pulmonary inflammation and severe pulmonary function deficits characteristic of IRIS. Sulfasalazine produced a profound attenuation of IRIS, with the unexpected consequence of accelerated fungal clearance. To determine whether macrophage phagocytosis is an effector mechanism of T cell-mediated Pneumocystis clearance and whether sulfasalazine enhances clearance by altering alveolar macrophage phagocytic activity, a novel multispectral imaging flow cytometer-based method was developed to quantify the phagocytosis of Pneumocystis in vivo. Following immune reconstitution, alveolar macrophages from PcP-IRIS mice exhibited a dramatic increase in their ability to actively phagocytose Pneumocystis. Increased phagocytosis correlated temporally with fungal clearance, and required the presence of CD4(+ T cells. Sulfasalazine accelerated the onset of the CD4(+ T cell-dependent alveolar macrophage phagocytic response in PcP-IRIS mice, resulting in enhanced fungal clearance. Furthermore, sulfasalazine promoted a TH2-polarized cytokine environment in the lung, and sulfasalazine-enhanced phagocytosis of Pneumocystis was associated with an alternatively activated alveolar macrophage phenotype. These results provide evidence that macrophage phagocytosis is an important in vivo effector mechanism for T cell-mediated Pneumocystis clearance, and that macrophage phenotype can be altered

  8. Safe laparoscopic clearance of the common bile duct in emergently admitted patients with choledocholithiasis and cholangitis

    Plaudis, Haralds; Fokins, Vladimirs; Mukans, Maksims; Pupelis, Guntars

    2016-01-01

    Backgrounds/Aims Laparoscopic treatment of patients with choledocholithiasis and cholangitis is challenging due to mandatory recovery of the biliary drainage and clearance of the common bile duct (CBD). The aim of our study was to assess postoperative course of cholangitis and biliary sepsis after laparoscopic clearance of the CBD in emergently admitted patients with choledocholithiasis and cholangitis. Methods Emergently admitted patients who underwent laparoscopic clearance of the CBD were included prospectively and stratified in 2 groups i.e., cholangitis positive (CH+) or negative (CH-) group. Patient demographics, comorbidities, preoperative imaging data, inflammatory response, surgical intervention, complication rate and outcomes were compared between groups. Results Ninety-nine of a total 320 patients underwent laparoscopic clearance of the CBD, of which, 60 belonged to the acute cholangitis group (CH+) and 39 to the cholangitis negative group (CH-). Interventions were done on average 4 days after admission, operation duration was 95-105 min, and the conversion rate was 3-7% without differences in the groups. Preoperative inflammatory response was markedly higher in the CH+ group. Inflammation signs on intraoperative choledochoscopy were more evident in patients with cholangitis. Postoperative inflammatory response did not differ between the groups. The overall complication rate was 8.3% and 5.1%, respectively. Laparoscopic clearance of the CBD resulted in 1 lethal case (CH+ group), resulting in 1% mortality rate and a similar 12-month readmission rate. Conclusions Single-stage laparoscopic intraoperative US and choledochoscopy-assisted clearance of the CBD is feasible in emergently admitted patients with choledocholithiasis and cholangitis. PMID:27212991

  9. Kinetics of the Clearance of Radioactive Colloids from Blood and the Physicochemical Characteristics of Their Morphology

    We are familiar with the differences to be found in the literature as regards the clearance of radioactive colloids from blood: in some cases clearance efficiency is equal to unity and hepatic flow can be measured with 131I-C. A., while in other cases the efficiency is highly variable and the flow cannot be measured externally with 198Au. The purpose of the present study was to obtain a better understanding of the differences that have been encountered in blood clearance of the following Saclay colloidal solutions: 198Au S2 and S3 solutions, which differ only in the dilution technique, technetium-99m T-cK1 and indium-113m InK1, For this purpose clearance curves were recorded in the same subject with different isotopes. Healthy subjects showed only slight differences, cirrhosis patients much larger ones. The authors have also attempted to relate the differences encountered to the physico-chemical characteristics of the morphology of the colloidal particles involved. For this purpose we used - apart from electron microscopy, which could not resolve the dimensions of the actual kinetic particle (including solvation) - techniques which caused a minimum of perturbation in the state of the product under study, such as optical methods of analysis. Lastly, an attempt has been made to investigate how one could use such clearance kinetics in routine functional studies while minimizing the influence of the nature of the product. For this purpose we have compared fractional clearance, already a standard technique, with the extra-hepatic fixation index which has been used at the Service Hospitalier Frédéric Joliot since 1966. (author)

  10. Hepatic and Extrahepatic Insulin Clearance Are Differentially Regulated: Results From a Novel Model-Based Analysis of Intravenous Glucose Tolerance Data.

    Polidori, David C; Bergman, Richard N; Chung, Stephanie T; Sumner, Anne E

    2016-06-01

    Insulin clearance is a highly variable and important factor that affects circulating insulin concentrations. We developed a novel model-based method to estimate both hepatic and extrahepatic insulin clearance using plasma insulin and C-peptide profiles obtained from the insulin-modified frequently sampled intravenous glucose tolerance test. Data from 100 African immigrants without diabetes (mean age 38 years, body weight 81.7 kg, fasting plasma glucose concentration 83 mg/dL, and fasting insulin concentration 37 pmol/L) were used. Endogenous insulin secretion (calculated by C-peptide deconvolution) and insulin infusion rates were used as inputs to a new two-compartment model of insulin kinetics and hepatic and extrahepatic clearance parameters were estimated. Good agreement between modeled and measured plasma insulin profiles was observed (mean normalized root mean square error 6.8%), and considerable intersubject variability in parameters of insulin clearance among individuals was identified (the mean [interquartile range] for hepatic extraction was 25.8% [32.7%], and for extrahepatic insulin clearance was 20.7 mL/kg/min [11.7 mL/kg/min]). Parameters of insulin clearance were correlated with measures of insulin sensitivity and acute insulin response to glucose. The method described appears promising for future research aimed at characterizing variability in insulin clearance and the mechanisms involved in the regulation of insulin clearance. PMID:26993071

  11. Radioactive waste management and clearance of accelerator waste at CERN

    The European Organization for Nuclear Research (CERN, Geneva, CH) has been operating accelerators for high-energy physics for more than 50 years. The interactions of the accelerated particles (for example protons up to 450 GeV and soon up to 7 TeV) and their secondaries with matter in various nuclear processes lead to the activation of accelerator components and other material. The resulting range of radionuclides depends on the irradiation history and the composition of the material. If accelerator components come to the end of their operational lifetime they will be disposed of as waste. This waste requires radiological characterization in order to be either declared as radioactive waste or, if appropriate, to be cleared and released. Different methods for the evaluation of the radionuclide inventory of activated components are currently under investigation at CERN. Due to its international status, CERN defines and applies its own set of regulations for operational radiation protection, which are comparable, but not necessarily identical, to those of the two CERN Host States: France and Switzerland. In the context of radioactive waste management in general - and of clearance in particular - however, CERN has to take account of host regulations. The differences between the French and Swiss regulations have a practical impact on the procedures to be applied at CERN. This paper provides a description of operational radioactive waste management at CERN, with focus on the methods for the radiological characterisation of the waste. Examples of the application of 'clearance' and a comparison between the Swiss and the French regulations in this field are provided. (author)

  12. pH modulation and salivary sugar clearance of different chocolates in children: A randomized clinical trial

    SVSG Nirmala

    2016-01-01

    Full Text Available Background: Sugars that occur naturally in foods and those added in processed foods may act as the source for fermentable carbohydrates and may initiate caries process. Among all the foods consumed by children, chocolates form an important constituent. A wide variety of chocolates are available in the Indian market and very few studies have compared their acidogenicity and salivary sugar clearance. Objectives: To compare the acidogenicity and salivary sugar clearance of 6 different commercially available chocolates in the Indian market. Materials and Methods: Thirty subjects aged 10-15 years were selected randomly from one of the available public schools in Nellore city. Six commercially available chocolates in the Indian market were divided into three groups, unfilled (dark and milk chocolate, filled (wafer and fruit and nuts chocolate, and candy (hard milk and mango-flavored candy groups. Plaque pH values and salivary sugar clearance rates are assessed at baseline, 5, 10, 15, 20, and 30 min after consumption. All the data obtained were statistically evaluated using independent sample t-test and one-way ANOVA for multiple group comparisons. Results: Mango-flavored candy had maximum fall in plaque pH and least fall in plaque pH was recorded with milk chocolate. Fruit and nuts chocolate had a maximum clearance of salivary sugar and least fall in the salivary sugar clearance was recorded with dark chocolate. When the plaque pH and salivary sugar clearance of all the chocolates were assessed, it was seen that the values were statistically significant at all the time intervals (P < 0.05. Conclusion: Dark chocolate had a high fall in pH and milk chocolate had low salivary sugar clearance which signifies that unfilled chocolates are more cariogenic than other chocolates. Even though mango-flavored candy had maximum fall in plaque pH, its salivary sugar clearance was high.

  13. Research on the effect of wear-ring clearances to the axial and radial force of a centrifugal pump

    Varying of the wear-ring clearance not only has a distinct effect on the volumetric loss of the centrifugal pump, but also on the performance of the centrifugal pump including the axial and radial forces. Comparing with the experimental studies, numerical simulation methods have some special advantages, such as the low cost, fast and high efficiency, and convenient to get the detailed structure of the internal flow characteristics, so it has been widely used in the fluid machinery study in recent years. In order to study the effect of wear-ring clearance on the force performance of the centrifugal pump, based on the Reynolds Time-Averaged N-S equations and RNG k-ε turbulence model, a centrifugal pump with three variable styles of the wear-rings was simulated: Only the clearance of the front wear-ring was changed, only the clearance of the back wear-ring was changed and both were changed. Comparing with the experiment, numerical results show a good agreement. In the three changing styles of the clearance, the variable of the clearance of front wear-ring has the most influence on the axial force of the centrifugal pump, while has tiny effect on the radial force for all the conditions

  14. Research on the effect of wear-ring clearances to the axial and radial force of a centrifugal pump

    Zhao, W. G.; Y He, M.; Qi, C. X.; Li, Y. B.

    2013-12-01

    Varying of the wear-ring clearance not only has a distinct effect on the volumetric loss of the centrifugal pump, but also on the performance of the centrifugal pump including the axial and radial forces. Comparing with the experimental studies, numerical simulation methods have some special advantages, such as the low cost, fast and high efficiency, and convenient to get the detailed structure of the internal flow characteristics, so it has been widely used in the fluid machinery study in recent years. In order to study the effect of wear-ring clearance on the force performance of the centrifugal pump, based on the Reynolds Time-Averaged N-S equations and RNG k-ε turbulence model, a centrifugal pump with three variable styles of the wear-rings was simulated: Only the clearance of the front wear-ring was changed, only the clearance of the back wear-ring was changed and both were changed. Comparing with the experiment, numerical results show a good agreement. In the three changing styles of the clearance, the variable of the clearance of front wear-ring has the most influence on the axial force of the centrifugal pump, while has tiny effect on the radial force for all the conditions.

  15. 14 CFR 29.411 - Ground clearance: tail rotor guard.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ground clearance: tail rotor guard. 29.411... System Loads § 29.411 Ground clearance: tail rotor guard. (a) It must be impossible for the tail rotor to contact the landing surface during a normal landing. (b) If a tail rotor guard is required to...

  16. 14 CFR 27.411 - Ground clearance: tail rotor guard.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ground clearance: tail rotor guard. 27.411... System Loads § 27.411 Ground clearance: tail rotor guard. (a) It must be impossible for the tail rotor to contact the landing surface during a normal landing. (b) If a tail rotor guard is required to...

  17. 48 CFR 2452.237-75 - Clearance of contractor personnel.

    2010-10-01

    ... personnel. 2452.237-75 Section 2452.237-75 Federal Acquisition Regulations System DEPARTMENT OF HOUSING AND... Clauses 2452.237-75 Clearance of contractor personnel. As prescribed in 2437.110(e), insert the following clause in solicitations and contracts. Clearance of Contractor Personnel (OCT 1999) (a) General....

  18. 48 CFR 32.502-2 - Contract finance office clearance.

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Contract finance office clearance. 32.502-2 Section 32.502-2 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION... finance office clearance. The contracting officer shall obtain the approval of the contract finance...

  19. 48 CFR 1432.502-2 - Contract finance office clearance.

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Contract finance office clearance. 1432.502-2 Section 1432.502-2 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR... finance office clearance. The CO shall obtain approval of the bureau finance office prior to...

  20. 48 CFR 832.502-2 - Contract finance office clearance.

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Contract finance office clearance. 832.502-2 Section 832.502-2 Federal Acquisition Regulations System DEPARTMENT OF VETERANS AFFAIRS... finance office clearance. Contracting officers must obtain approval from the DSPE before taking...

  1. Mechanistic evaluation of virus clearance by depth filtration.

    Venkiteshwaran, Adith; Fogle, Jace; Patnaik, Purbasa; Kowle, Ron; Chen, Dayue

    2015-01-01

    Virus clearance by depth filtration has not been well-understood mechanistically due to lack of quantitative data on filter charge characteristics and absence of systematic studies. It is generally believed that both electrostatic interactions and sized based mechanical entrapment contribute to virus clearance by depth filtration. In order to establish whether the effectiveness of virus clearance correlates with the charge characteristics of a given depth filter, a counter-ion displacement technique was employed to determine the ionic capacity for several depth filters. Two depth filters (Millipore B1HC and X0HC) with significant differences in ionic capacities were selected and evaluated for their ability to eliminate viruses. The high ionic capacity X0HC filter showed complete porcine parvovirus (PPV) clearance (eliminating the spiked viruses to below the limit of detection) under low conductivity conditions (≤2.5 mS/cm), achieving a log10 reduction factor (LRF) of > 4.8. On the other hand, the low ionic capacity B1HC filter achieved only ∼2.1-3.0 LRF of PPV clearance under the same conditions. These results indicate that parvovirus clearance by these two depth filters are mainly achieved via electrostatic interactions between the filters and PPV. When much larger xenotropic murine leukemia virus (XMuLV) was used as the model virus, complete retrovirus clearance was obtained under all conditions evaluated for both depth filters, suggesting the involvement of mechanisms other than just electrostatic interactions in XMuLV clearance. PMID:25683459

  2. Clearance systems in the brain-implications for Alzheimer disease.

    Tarasoff-Conway, Jenna M; Carare, Roxana O; Osorio, Ricardo S; Glodzik, Lidia; Butler, Tracy; Fieremans, Els; Axel, Leon; Rusinek, Henry; Nicholson, Charles; Zlokovic, Berislav V; Frangione, Blas; Blennow, Kaj; Ménard, Joël; Zetterberg, Henrik; Wisniewski, Thomas; de Leon, Mony J

    2015-08-01

    Accumulation of toxic protein aggregates-amyloid-β (Aβ) plaques and hyperphosphorylated tau tangles-is the pathological hallmark of Alzheimer disease (AD). Aβ accumulation has been hypothesized to result from an imbalance between Aβ production and clearance; indeed, Aβ clearance seems to be impaired in both early and late forms of AD. To develop efficient strategies to slow down or halt AD, it is critical to understand how Aβ is cleared from the brain. Extracellular Aβ deposits can be removed from the brain by various clearance systems, most importantly, transport across the blood-brain barrier. Findings from the past few years suggest that astroglial-mediated interstitial fluid (ISF) bulk flow, known as the glymphatic system, might contribute to a larger portion of extracellular Aβ (eAβ) clearance than previously thought. The meningeal lymphatic vessels, discovered in 2015, might provide another clearance route. Because these clearance systems act together to drive eAβ from the brain, any alteration to their function could contribute to AD. An understanding of Aβ clearance might provide strategies to reduce excess Aβ deposits and delay, or even prevent, disease onset. In this Review, we describe the clearance systems of the brain as they relate to proteins implicated in AD pathology, with the main focus on Aβ. PMID:26195256

  3. 5 CFR 720.307 - Interagency report clearance.

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Interagency report clearance. 720.307 Section 720.307 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS (CONTINUED) AFFIRMATIVE EMPLOYMENT PROGRAMS Disabled Veterans Affirmative Action Program § 720.307 Interagency report clearance. The...

  4. 14 CFR 375.24 - Entry and clearance.

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Entry and clearance. 375.24 Section 375.24 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) SPECIAL REGULATIONS NAVIGATION OF FOREIGN CIVIL AIRCRAFT WITHIN THE UNITED STATES Rules Generally Applicable § 375.24 Entry and clearance. All...

  5. 33 CFR 160.115 - Withholding of clearance.

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Withholding of clearance. 160.115 Section 160.115 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY PORTS AND WATERWAYS SAFETY-GENERAL Control of Vessel and Facility Operations § 160.115 Withholding of clearance....

  6. 48 CFR 952.204-73 - Facility clearance.

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Facility clearance. 952.204-73 Section 952.204-73 Federal Acquisition Regulations System DEPARTMENT OF ENERGY CLAUSES AND FORMS SOLICITATION PROVISIONS AND CONTRACT CLAUSES Text of Provisions and Clauses 952.204-73 Facility clearance. As prescribed in 904.404(d)(5),...

  7. Benefits of Improved HP Turbine Active Clearance Control

    Ruiz, Rafael; Albers, Bob; Sak, Wojciech; Seitzer, Ken; Steinetz, Bruce M.

    2007-01-01

    As part of the NASA Propulsion 21 program, GE Aircraft Engines was contracted to develop an improved high pressure turbine(HPT) active clearance control (ACC) system. The system is envisioned to minimize blade tip clearances to improve HPT efficiency throughout the engine operation range simultaneously reducing fuel consumption and emissions.

  8. Allometric scaling for predicting human clearance of bisphenol A

    The investigation of interspecies differences in bisphenol A (BPA) pharmacokinetics (PK) may be useful for translating findings from animal studies to humans, identifying major processes involved in BPA clearance mechanisms, and predicting BPA PK parameters in man. For the first time, a large range of species in terms of body weight, from 0.02 kg (mice) to 495 kg (horses) was used to predict BPA clearance in man by an allometric approach. BPA PK was evaluated after intravenous administration of BPA in horses, sheep, pigs, dogs, rats and mice. A non-compartmental analysis was used to estimate plasma clearance and steady state volume of distribution and predict BPA PK parameters in humans from allometric scaling. In all the species investigated, BPA plasma clearance was high and of the same order of magnitude as their respective hepatic blood flow. By an allometric scaling, the human clearance was estimated to be 1.79 L/min (equivalent to 25.6 mL/kg.min) with a 95% prediction interval of 0.36 to 8.83 L/min. Our results support the hypothesis that there are highly efficient and hepatic mechanisms of BPA clearance in man. - Highlights: • Allometric scaling was used to predict BPA pharmacokinetic parameters in humans. • In all species, BPA plasma clearance approached hepatic blood flow. • Human BPA clearance was estimated to be 1.79 L/min

  9. Radioaerosol delivery and clearance in patients with respiratory failure

    A technique for radioaerosol delivery to patients requiring mechanical ventilation is described. Ventilation images and pulmonary radioaerosol clearance rates were successfully obtained in 35 patients regardless of ventilator type or level of positive end-expiratory pressure (PEEP). Those patients with noncardiogenic pulmonary edema (NPE) had significantly increased clearance rates relative to those patients in whom NPE was not present

  10. Allometric scaling for predicting human clearance of bisphenol A

    Collet, Séverine H., E-mail: s.collet@envt.fr; Picard-Hagen, Nicole, E-mail: n.hagen-picard@envt.fr; Lacroix, Marlène Z., E-mail: m.lacroix@envt.fr; Puel, Sylvie, E-mail: s.puel@envt.fr; Viguié, Catherine, E-mail: c.viguie@envt.fr; Bousquet-Melou, Alain, E-mail: a.bousquet-Melou@envt.fr; Toutain, Pierre-Louis, E-mail: pltoutain@wanadoo.fr; Gayrard, Véronique, E-mail: v.gayrard@envt.fr

    2015-05-01

    The investigation of interspecies differences in bisphenol A (BPA) pharmacokinetics (PK) may be useful for translating findings from animal studies to humans, identifying major processes involved in BPA clearance mechanisms, and predicting BPA PK parameters in man. For the first time, a large range of species in terms of body weight, from 0.02 kg (mice) to 495 kg (horses) was used to predict BPA clearance in man by an allometric approach. BPA PK was evaluated after intravenous administration of BPA in horses, sheep, pigs, dogs, rats and mice. A non-compartmental analysis was used to estimate plasma clearance and steady state volume of distribution and predict BPA PK parameters in humans from allometric scaling. In all the species investigated, BPA plasma clearance was high and of the same order of magnitude as their respective hepatic blood flow. By an allometric scaling, the human clearance was estimated to be 1.79 L/min (equivalent to 25.6 mL/kg.min) with a 95% prediction interval of 0.36 to 8.83 L/min. Our results support the hypothesis that there are highly efficient and hepatic mechanisms of BPA clearance in man. - Highlights: • Allometric scaling was used to predict BPA pharmacokinetic parameters in humans. • In all species, BPA plasma clearance approached hepatic blood flow. • Human BPA clearance was estimated to be 1.79 L/min.

  11. Study of global operational needs for mine clearance equipment

    Blagden, Paddy M.

    2003-09-01

    The Geneva International Centre for Humanitarian Demining studied the needs of landmine clearance groups for equipment to carry out specific functions of mine clearance. This was done on a global level, and useful results were obtained, which will provide the basis for further analysis.

  12. Guidance of clearance related standards in reactor facilities

    The reactor regulation law was amended in May 2005 to provide for the clearance system. The regulatory body confirmed radioactivity concentration of material and allowed the material be classified as 'material cleared from regulatory control'. The procedure of confirmation consisted of two steps; 1) methodology and 2) results, of measurement and assessment. Clearance related standards were issued as ordinance of Ministry and NISA information notice, which specified radioactive nuclides, radioactivity concentration, evaluation unit, how to decide radioactivity concentration, radiation measurement equipment and control of object material. This report was guidance of clearance related standards in reactor facilities with explanatory notes. By applying the clearance system, material of insignificant radiation level, which was part of concrete or metals generated from decommissioning of reactor facilities, could be released from regulatory control of radioactive waste as clearance material, and recycle of such material could result in reduction of radioactive waste amount. (T. Tanaka)

  13. Association of Continuous-Equivalent Urea Clearances with Death Risk in Intermittent Hemodialysis

    Aarne Vartia

    2016-01-01

    Full Text Available Background. Several reports describe favorable results from frequent hemodialysis, but due to the lack of unequivocal dose measures it is not clear whether the benefits are due to more efficient toxin removal or other factors. Methods. The associations with death risk of six continuous-equivalent urea clearance measures were compared in 57 conventional in-center hemodialysis treatment periods of 51 patients, together 114 patient years. The double pool dose measures were calculated with the Solute-Solver program and separately scaled to urea distribution volume or normalized with body surface area. Results. Mortality associated significantly with equivalent renal urea clearance (EKR scaled to urea distribution volume (V (p=0.033 and with EKR normalized with body surface area (BSA (p=0.044 but not with V-scaled (p=0.059 nor BSA-normalized (p=0.183 standard clearance (stdK. Women had significantly higher normalized protein catabolic rate (nPCR, EKR/V, and stdK/V than men but slightly lower BSA-normalized dose measures and lower mortality. Protein catabolic rate and dialysis dose correlated positively with each other and with survival. Conclusions. The prognostically most valid continuous-equivalent clearance in the present material was EKR/V, calculated from double pool urea generation rate, distribution volume, and time-averaged concentration.

  14. Site of deposition and factors affecting clearance of aerosolized solute from canine lungs

    The influence of several factors on lung solute clearance using aerosolized /sup 99m/Tc-diethylenetriaminepentaacetate was determined. The authors used a jet nebulizer-plate separator-balloon system to generate particles with an activity median aerodynamic diameter of 1.1 μm, administered the aerosol in a standard fashion, and determined clearance half times (t/sub 1/2/) with a gamma-scintillation camera. The following serial studies were performed in five anesthetized, paralyzed, intubated, mechanically ventilated dogs: (1) control, with ventilatory frequency (f) = 15 breaths/min and tidal volume (V/sub T/) = 15 ml/kg during solute clearance; (2) repeat control, for reproducibility; (3) increased frequency, with f = 25 breaths/min and V/sub T/ = 10 ml/kg; (4) positive end-expiratory pressure (PEEP) of 10 cmH2O; (5) unilateral pulmonary arterial occlusion (PAO); and (6) bronchial arterial occlusion (BAO). Control t/sub 1/2/ was 25 +/- 5 min and did not change in the repeat control, increased frequency, or BAO experiments. PEEP markedly decreased t/sub 1/2/ to 13 +/- 3 min (P < 0.01), and PAO increased it to 37 +/- 6 min (P < 0.05). We conclude that clearance from the lungs by our method is uninfluenced by increased frequency, increases markedly with PEEP, and depends on pulmonary, not bronchial, blood flow

  15. Numerical error evaluation for tip clearance flow calculations in a centrifugal compressor

    Dufour, Guillaume; CARBONNEAU, Xavier; Arbez, Pierre; Cazalbou, Jean-Bernard; Chassaing, Patrick

    2004-01-01

    Since globally mesh independent solution are still beyond available computer resources for industrial cases, a method to quantify locally the numerical error is proposed. The design of experiments method helps selecting mesh parameters that influence the tip clearance solution, so that additional meshes are computed to evaluate the numerical error on the shroud friction coefficient. In the field of CFD applied to turbomachinery, this study results from a partnership between ENSICA, Liebher...

  16. Nuclear regulation. NRC's security clearance program can be strengthened

    Because of the national security implications of its programs, the Nuclear Regulatory Commission (NRC) investigates the background of its employees and consultants as well as others to ensure that they are reliable and trustworthy. If the investigation indicates that an employee will not endanger national security, NRC grants a security clearance that allows access to classified information, material, and facilities. NRC also requires periodic checks for some clearance holders to ensure their continued clearance eligibility. The Chairman, Subcommittee on Environment, Energy, and Natural Resources, House Committee on Government Operations, asked GAO to review NRC's personnel security clearance program and assess the procedures that NRC uses to ensure that those who operate nuclear power plants do not pose a threat to the public. The Atomic Energy Act of 1954 requires NRC to conduct background investigations of its employees and consultants as well as others who have access to classified information, material, or facilities. To do this, NRC established a personnel security clearance program. Under NRC policies, a security clearance is granted after the Office of Personnel Management (OPM) or the Federal Bureau of Investigation checks the background of those applying for an NRC clearance. NRC also periodically reassesses the integrity of those holding the highest level clearance. NRC employees, consultants, contractors, and licensees as well as other federal employees hold approximately 10,600 NRC clearances. NRC does not grant clearances to commercial nuclear utility employees unless they require access to classified information or special nuclear material. However, the utilities have voluntarily established screening programs to ensure that their employees do not pose a threat to nuclear plants. NRC faces a dilemma when it hires new employees. Although its policy calls for new hires to be cleared before they start work, the security clearance process takes so long

  17. The role of blood lactate clearance as a predictor of mortality in children undergoing surgery for tetralogy of Fallot

    Ladha, Suruchi; Kapoor, Poonam Malhotra; Singh, Sarvesh Pal; Kiran, Usha; Chowdhury, Ujjwal Kumar

    2016-01-01

    Background: The identification of biomarkers for predicting morbidity and mortality, particularly in pediatric population undergoing cardiac surgery will contribute toward improving the patient outcome. There is an increasing body of literature establishing the clinical utility of hyperlactatemia and lactate clearance as prognostic indicator in adult cardiac surgical patients. However, the relationship between lactate clearance and mortality risk in the pediatric population remains to be established. Objective: To assess the role of lactate clearance in determining the outcome in children undergoing corrective surgery for tetralogy of Fallot (TOF). Methods and Study Design: A prospective, observational study. Setting: A tertiary care center. Study Population: Two hundred children undergoing elective surgery for TOF. Study Method: Blood lactate levels were obtained as baseline before operation (T0), postoperatively at admission to the cardiac intensive care unit after surgery (T1), and then at every 6 h for the first 24 h of Intensive Care Unit (ICU) stay (T6, T12, T18, and T24, respectively). The lactate clearance in the study is defined by the equation ([lactate initial – lactate delayed]/lactate initial) ×100%. Lactate clearance was determined at T1–T6, T1–T12, T1–T18, and T1–T24 time interval, respectively. The primary outcome measured was mortality. Secondary outcomes measured were the duration of mechanical ventilation, duration of inotropic requirement, and duration of ICU stay. Results: Eleven out of the two hundred patients enrolled in the study died. Nonsurvivors had higher postoperative lactate concentration (P 10%, relative to patients with a lactate clearance 10%) after 6 h have improved outcome compared with those with lower lactate clearance. PMID:27052060

  18. The role of blood lactate clearance as a predictor of mortality in children undergoing surgery for tetralogy of Fallot

    Suruchi Ladha

    2016-01-01

    Full Text Available Background: The identification of biomarkers for predicting morbidity and mortality, particularly in pediatric population undergoing cardiac surgery will contribute toward improving the patient outcome. There is an increasing body of literature establishing the clinical utility of hyperlactatemia and lactate clearance as prognostic indicator in adult cardiac surgical patients. However, the relationship between lactate clearance and mortality risk in the pediatric population remains to be established. Objective: To assess the role of lactate clearance in determining the outcome in children undergoing corrective surgery for tetralogy of Fallot (TOF. Methods and Study Design: A prospective, observational study. Setting: A tertiary care center. Study Population: Two hundred children undergoing elective surgery for TOF. Study Method: Blood lactate levels were obtained as baseline before operation (T0, postoperatively at admission to the cardiac intensive care unit after surgery (T1, and then at every 6 h for the first 24 h of Intensive Care Unit (ICU stay (T6, T12, T18, and T24, respectively. The lactate clearance in the study is defined by the equation ([lactate initial - lactate delayed]/lactate initial ×100%. Lactate clearance was determined at T1-T6, T1-T12, T1-T18, and T1-T24 time interval, respectively. The primary outcome measured was mortality. Secondary outcomes measured were the duration of mechanical ventilation, duration of inotropic requirement, and duration of ICU stay. Results: Eleven out of the two hundred patients enrolled in the study died. Nonsurvivors had higher postoperative lactate concentration (P 10%, relative to patients with a lactate clearance 10% after 6 h have improved outcome compared with those with lower lactate clearance.

  19. Measurement of tracheobronchial clearance after sauna in subjects with chronic bronchitis.

    van Hengstum, M; Festen, J.; Corstens, F.

    1991-01-01

    The effect of sauna on tracheobronchial clearance was studied in five male patients with chronic bronchitis by a radioaerosol technique. No enhancement of tracheobronchial clearance could be detected.

  20. Clearance and Exemption- Application in EU Member Status

    This paper summarises the findings of the European Commission project commissioned to provide information on the application of the concepts of exemption and clearance for practices according to Title III of Council Directive 96/29/EURATOM (Directive) of 13 May 1996 (Directive). The study collated and then evaluated information on the legal instruments and application of exemption and clearance in all EU Member States. It was found that most Member States in the EU have introduced new legislation to address the Directive within the past 2-3 years. Exemption has been implemented by the majority of Member States in a way consistent with Title III of the Directive. The area of greatest variation relates to the introduction of clearance levels. In most Member States clearance levels, when adopted, are not based on values published in guidance from the European Commission. It was found that there is a variation of up to four orders of magnitude between the clearance levels used in some Member States and those recommended in European Commission guidance. It is clear, following the review of implementation in Member States, that there is a need for additional guidance on various aspects of the implementation of the concepts of exemption and clearance; including on surface contamination levels and decay storage. Clearance guidance for small users such as universities and hospitals would also be welcomed. (Author) 9 refs

  1. Secretin enhances [14C]erythritol clearance in unanesthetized dogs

    To determine the effect of secretin infusion on clearance of inert markers into bile, unanesthetized dogs fitted with Thomas cannulas received continuous infusions of [14C]erythritol and [3H]inulin throughout study. Taurocholic acid administered sequentially at 9.0, 20.0, and 40.0 mumol/min enhanced [14C]erythritol clearance, and GIH secretin (3 units/min) administered along with TCA (40.0 mumol/min) increased [14C]erythritol clearance from 4.9 +/- 1.2 ml/10 min to 6.8 +/- 1.3 ml/10 min (P less than 0.001), but simultaneously measured [3H]inulin clearance was unaltered. Secretin alone also increased [14C]erythritol clearance but did not alter [3H]inulin clearance. The increase in [14C]erythritol clearance per unit increase in bile flow was less during secretin infusion than TCA. Thus, secretin increases [14C]erythritol transport through restricted channels, probably distal to the canaliculi. [14C]Erythritol may not be an accurate marker for canalicular bile flow in dogs during secretin infusion

  2. Female sex and IL28B, a synergism for spontaneous viral clearance in hepatitis C virus (HCV seroconverters from a community-based cohort.

    Charlotte H B S van den Berg

    Full Text Available BACKGROUND & AIMS: Since acute hepatitis C virus (HCV infection is often asymptomatic, it is difficult to examine the rate and determinants of spontaneous clearance. Consequently, these studies are subject to bias, which can potentially lead to biased rates of viral clearance and risk estimates. We evaluated determinants of spontaneous HCV clearance among HCV seroconverters identified in a unique community-based cohort. METHODS: Subjects were 106 drug users with documented dates of HCV seroconversion from the Amsterdam Cohort Study. Logistic regression was used to examine sociodemographic, behavioral, clinical, viral and host determinants, measured around acute infection, of HCV clearance. RESULTS: The spontaneous viral clearance rate was 33.0% (95% confidence interval (CI 24.2-42.8. In univariate analyses female sex and fever were significantly associated with spontaneous clearance. The favorable genotypes for rs12979860 (CC and rs8099917 (TT were associated with spontaneous clearance, although borderline significant. In multivariate analysis, females with the favorable genotype for rs12979860 (CC had an increased odds to spontaneously clear HCV infection (adjusted OR 6.62, 95% 2.69-26.13, whereas females with the unfavorable genotype were as likely as men with the favorable and unfavorable genotype to clear HCV. Chronic Hepatitis B infection and absence of HIV coinfection around HCV seroconversion also favor HCV clearance. CONCLUSIONS: This study shows that co-infection with HIV and HBV and genetic variation in the IL28B region play an important role in spontaneous clearance of HCV. Our findings suggest a possible synergistic interaction between female sex and IL28B in spontaneous clearance of HCV.

  3. The value of level III clearance in patients with axillary and sentinel node positive breast cancer.

    Dillon, Mary F

    2012-02-01

    BACKGROUND: The value of level III axillary clearance is contentious, with great variance worldwide in the extent and levels of clearance performed. OBJECTIVE: To determine rates of level III positivity in patients undergoing level I-III axillary clearance, and identify which patients are at highest risk of involved level III nodes. METHODS: From a database of 2850 patients derived from symptomatic and population-based screening service, 1179 patients who underwent level I-III clearance between the years 1999-2007 were identified. The pathology, surgical details, and prior sentinel nodes biopsies of patients were recorded. RESULTS: Eleven hundred seventy nine patients had level I-III axillary clearance. Of the patients, 63% (n = 747) were node positive. Of patients with node positive disease, 23% (n = 168) were level II positive and 19% (n = 141) were level III positive. Two hundred fifty patients had positive sentinel node biopsies prior to axillary clearance. Of these, 12% (n = 30) and 9% (n = 22) were level II and level III positive, respectively. On multivariate analysis, factors predictive of level III involvement in patients with node positive disease were tumor size (P < 0.001, OR = 1.36; 95% CI: 1.2-1.5), invasive lobular disease (P < 0.001, OR = 3.6; 95% CI: 1.9-6.95), extranodal extension (P < 0.001, OR = 0.27; 95% CI: 0.18-0.4), and lymphovascular invasion (P = 0.04, OR = 0.58; 95% CI: 0.35-1). Lobular invasive disease (P = 0.049, OR = 4.1; 95% CI: 1-16.8), extranodal spread (P = 0.003, OR = 0.18; 95% CI: 0.06-0.57), and having more than one positive sentinel node (P = 0.009, OR = 4.9; 95% CI: 1.5-16.1) were predictive of level III involvement in patients with sentinel node positive disease. CONCLUSION: Level III clearance has a selective but definite role to play in patients who have node positive breast carcinoma. Pathological characteristics of the primary tumor are of particular use in identifying those who are at various risk of level III nodal

  4. Effect of increased surface tension and assisted ventilation on /sup 99m/Tc-DTPA clearance

    Experiments were performed to determine the effects of conventional mechanical ventilation (CMV) and high-frequency oscillation (HFO) on the clearance of technetium-99m-labeled diethylenetriamine pentaacetate (/sup 99m/Tc-DTPA) from lungs with altered surface tension properties. A submicronic aerosol of /sup 99m/Tc-DTPA was insufflated into the lungs of anesthetized, tracheotomized rabbits before and 1 h after the administration of the aerosolized detergent dioctyl sodium sulfosuccinate (OT). Rabbits were ventilated by one of four methods: 1) spontaneous breathing; 2) CMV at 12 cmH2O mean airway pressure (MAP); 3) HFO at 12 cmH2O MAP; 4) HFO at 16 cmH2O MAP. Administration of OT resulted in decreased arterial PO2 (PaO2), increased lung wet-to-dry weight ratios, and abnormal lung pressure-volume relationships, compatible with increased surface tension. /sup 99m/Tc-DTPA clearance was accelerated after OT in all groups. The post-OT rate of clearance (k) was significantly faster (P less than 0.05) in the CMV at 12 cmH2O MAP [k = 7.57 +/- 0.71%/min (SE)] and HFO at 16 cmH2O MAP (k = 6.92 +/- 0.61%/min) groups than in the spontaneously breathing (k = 4.32 +/- 0.55%/min) and HFO at 12 cmH2O MAP (4.68 +/- 0.63%/min) groups. The clearance curves were biexponential in the former two groups. We conclude that pulmonary clearance of /sup 99m/Tc-DTPA is accelerated in high surface tension pulmonary edema, and this effect is enhanced by both conventional ventilation and HFO at high mean airway pressure

  5. Development of a computer system for support and documentation of clearance of buildings of nuclear installations - 59278

    Clearance of buildings of nuclear installations in Germany has to comply with general requirements laid down in Section 29 of the German Radiation Protection Ordinance (RPO; Strahlenschutzverordnung), clearance levels as stipulated in Table 1 of Annex III RPO and technical guidance given in the technical standard DIN 25457. Clearance procedures are usually proposed by the licensee and are made part of a decommissioning licence after appropriate review by the authorities. The clearance procedures consist of a radiological characterisation of the various parts of the buildings, a decontamination step if necessary, followed by measurements for checking the success of decontamination, and the actual decision measurements for demonstrating compliance with clearance levels. These three steps rely on various measurement methods, selected depending on the relevant radionuclides to be measured, like sampling with subsequent gamma spectrometry (and if necessary separate evaluation of beta and alpha emitting nuclides), measurements with surface contamination monitory and in situ gamma spectrometry. For a nuclear power plant, the number of samples taken during this procedure can easily reach a few 10, 000, while the number of single measurements can reach several 100, 000 single surface measurements and several 10, 000 measurements with in situ gamma spectrometry. This large number of data together with the correct interpretation according to the valid nuclide vector, the penetration depth of the contamination, the correction for radioactive decay etc have to be managed, which is a error-prone process if carried out manually or with insufficient support by customised software. For this reason, a versatile software tool has been developed by Brenk Systemplanung GmbH that supports the operator in all aspects of clearance of buildings, based on the extensive experience with various clearance procedures in nuclear power plants that Brenk Systemplanung has carried out in the past

  6. Clearance from the anterior chamber of RBCs from human diabetics

    Erythrocytes from diabetic patients manifest decreased deformability and increased adherence. These abnormal membrane properties may diminish the ability of erythrocytes (RBCs) from diabetics to undergo deformation in passage through the trabecular meshwork. Using sodium chromate Cr 51-labeled RBCs from type I diabetic patients with proliferative retinopathy and normal control subjects, we studied RBC clearance from the rabbit anterior chamber. The mean time for 50% clearance (T50) of RBCs from diabetics (76 hours) was significantly longer than that for RBCs from normal subjects (19.5 hours). In this model, RBCs from diabetics have a slower clearance from the anterior chamber than do RBCs from normal subjects

  7. Wind Power and Fault Clearance. Final Report

    Vikesjoe, Johnny; Messing, Lars (Gothia Power (Sweden))

    2011-04-15

    The increased penetration of wind power will increase the impact of wind power on the grid and thereby increase the importance of a clear guidance concerning the requirements on the protection system of the wind power units and the grid protection in connection to wind power units. The protection system should be able to satisfy the grid connection requirements, set by the TSO (Transmission System Operator) and the grid owners, as well as the general safety and security requirements, such as; personal safety, operational security and economic insurance, i.e. an insurance against economic losses. Vindforsk has appointed Gothia Power AB to perform a study concerning the fault clearance function in connection to wind power installations. The study is divided into two parts; Part 1: The first stage of the project handled the present praxis for the protection, including investigation of legal requirements, operational requirement and personal safety requirement applicable to wind power applications. Proposals for protection requirement for wind power units and the connecting grid are given. Basically 'normal' fault clearance requirements regarding speed, selectivity and redundancy can be used also in applications in connection to wind power. Part 2: The second part of the project results in a guideline for design of protection systems in connection to wind power. In this report mainly part 2 is covered. The main focus is given to clearance of faults in the grid connecting the wind power plants. Regarding internal faults and critical operation states within the wind power plant, a short discussion of feasible protection functions is given. Some critical fault cases in the grid have been identified and discussed: - Undetected islanding and failure of reclosing. There can be a risk of undetected island operation. In such cases it is recommended to use controlled autoreclosing in the vicinity of wind power generation. - Unwanted disconnection of a healthy feeder

  8. Clearance gap flow: simulations by discontinuous Galerkin method and experiments

    Prausová, H.; Bublík, O.; Vimmr, J.; Luxa, Martin; Hála, Jindřich

    Paris : E D P SCIENCES, 2015 - (Vít, T.; Dančová, P.), 02073-02073 ISSN 2100-014X. - (EPJ Web of Conferences. 92). [Experimental Fluid Mechanics 2014. Český Krumlov (CZ), 18.11.2014-21.11.2014] Institutional support: RVO:61388998 Keywords : numerical simulation * narrow channels * compressible fluid flow Subject RIV: BK - Fluid Dynamics

  9. A STUDY ON EGFR, CREATININE CLEARANCE & URINARY PROTEIN TO CREATININE RATIO IN CKD

    Ganga Bhavani

    2014-05-01

    Full Text Available There was a good correlation between Glomerular Filtration Rate (GFR values estimated by any of the 3 methods. Crcl correlated better with Cockcroft-Gault (CG eGFR than Modification of Diet in Renal Disease (MDRD eGFR and there was also a very good correlation between CG eGFR and MDRD eGFR. Based on this result we feel that in advanced CKD all 3 methods give similar GFR estimates but in earlier stages of Chronic Kidney Disease (CKD Creatinine clearance (Crcl gives higher estimate of GFR. Thus use of Crcl may wrongly classify patients into less severe stages of CKD which might lead to delay in initiation of proper treatment. MATERIALS AND METHODS: CKD patients were selected on the basis of serum creatinine levels. S.C > 2.5 mg/dl values were considered to be having CKD. 75 Samples were tested. Both males & females patients are taken in this study. Serum Creatinine & Urinary Creatinine by Jaffe’s method, Blood Urea by Urease method, Urinary Protein by Pyrogallol red method, estimation of GFR by three methods. Creatinine Clearance &eGFR by using Cockcroft- Gault& MDRD equations. RESULT: A total of 75 patients attending the nephrology department (P.E.S Medical College, Kuppamfor treatment and monitoring for chronic kidney disease where included in the present study. Serum creatinine, serum urea and creatinine clearance were measured in all these patients as per methods described under materials and methods. Estimated GFR (eGFR using CG (Cock croft and MDRD (Modification of Diet in renal disease formulae were calculated. Majority of the cases were complications due to long standing diabetes mellitus or hypertension. CONCLUSION: Creatinine Clearance over estimates GFR in early stages of CKD. Use of Crcl to assess GFR may not be proper to classify CKD into different stages. Any of the 3 methods (Crcl, CG eGFR and MDRD eGFR can be used as markers of GFR in advanced stages of CKD. MDRD eGFR is a better indicator of eGFR for staging CKD in early stages

  10. Metabolic clearance rate and urinary clearance of purified beta-core

    We injected a highly purified preparation of the beta-core molecule, a fragment of hCG beta excreted in pregnancy urine, into five men and three women to determine its kinetic parameters, MCR, and urinary clearance. The beta-core molecule was distributed in an initial volume [1950 +/- 156 (mean +/- SEM) mL/m2 body surface area] approximately equal to the estimated plasma volume. Its disappearance was multiexponential on a semilogarithmic plot, with a rapid phase t1/2 of 3.5 +/- 0.7 min and a slow phase t1/2 of 22.4 +/- 4.2 min. The transit time (the mean time spent by a molecule of beta-core in transit) was 20.6 +/- 2.1 min. The MCR was 192.0 +/- 8.0 mL/min.m2 body surface area. About 5% of the injected dose of beta-core was excreted into the urine in the first 30 min after injection, and low levels of excretion persisted for up to 7 days. The urinary clearance rate of beta-core was 13.7 +/- 1.4 mL/min.m2, accounting for about 8% of the elimination of beta-core from the plasma. The beta-core immunoreactivity in serum and urine was characterized by gel filtration and three independent RIA systems to show that its properties were indistinguishable from those of the injected beta-core. Serum levels of beta-core in pregnant women were less than 0.2 ng/mL, while the amounts excreted in their urine were as much as 5 mg/day. Based on these clearance parameters of beta-core in normal subjects, less than 0.2% of the beta-core excreted in pregnancy urine is derived by urinary clearance of plasma beta-core. Therefore, more than 99% of the beta-core excreted in pregnancy urine is derived from beta-core in a compartment separate from plasma. In particular, these data indicate that there is relatively little placental secretion of beta-core into plasma and that placental secretion does not account for the vast majority of beta-core in pregnancy urine

  11. Scintigraphic examination of mucociliary clearance; Die szintigrafische Untersuchung der mukoziliaeren Clearance

    Flierdt, E. van de; Haidl, P. [Gemeinschaftspraxis F. Radiologie und Nuklearmedizin, Muenchen (Germany); Abt. Pneumologie II, Fachkrankenhaus Kloster Grafschaft, Schmallenberg (Germany)

    2009-03-15

    Scintigraphic evaluation of mucociliary clearance (MC) is in consideration of some guidelines (choice of a suitable inhalator and standardization of inhalation procedure) simply practicable. Using a standardized median aerosol with a diameter of approximately 8 {mu}m a dynamic investigation over 60 min is sufficient. Depending on the medical problem MC can be calculated globally or regionally. Indications for the investigation of MC are primary ciliary dyskinesia, persistent cough of unknown origin as well as a possible regional disturbance of MC. Disturbances of MC occur before changes in spirometric pulmonary function tests. Therefore scintigraphic evaluation of MC is suited to early diagnosis of changes in mucociliary removal rates. (orig.)

  12. THE ROLE OF LACTATE CLEARANCE AS A PREDICTOR OF ORGAN DYSFUNCTION AND MORTALITY IN PATIENTS WITH SEVERE SEPSIS

    Bolvardi, Ehsan; Malmir, Jafar; Reihani, Hamidreza; Hashemian, Amir Masoud; Bahramian, Mehran; Khademhosseini, Peyman; Ahmadi, Koorosh

    2016-01-01

    Background: Little is known about biomarkers which are used to classification of patients in order to diagnosis severity of sepsis among clients of emergency units. It seems that Lactate’s clearance can be used in this regard. This study aimed to determine the relationship between Lactate’s clearance, mortality and organ’s dysfunction with severe sepsis. Materials and methods: In this study 90 patients with severe sepsis, were visited and examined exactly. Para clinical tests, serum venous lactate, organ’s dysfunction scores, Acute Physiology and Chronic Health Evaluation II (APACHE-II) and Sequential Organ Failure Assessment (SOFA) were applied upon admission and 6 hours after it. According to clinical and laboratory criteria, dysfunction in main organs were examined and Lactate’s Clearance was accounted. All the patients were cured according to early goal-directed therapy protocol. Results: Among the participants 49 and 41 were male and female respectively. The mean age of the group was 49.37±1.41. The patients were classified to groups, less or more than 10% lactate’s clearance. Mortality rate of the patients was 18.9% (17 people). Mean age of the dead group was 49.71±13.33. The mean of dysfunctional organs which is assessed in terms of clinical, laboratory and SOFA criteria was significantly higher among the dead group than other. The Lactate’s clearance in the dead group was significantly lower than the other group (p<.05). Conclusion: It was concluded that patients with severe sepsis is a marker which is related to tissue hypoxia, also lactate’s clearance increasing is related to drastic reduction in biomarkers, mortality, and incidence of organ’s dysfunction. Overall, patients with lower lactate’s clearance are counted a high risk group for mortality and organs’ dysfunction. PMID:27047270

  13. Comparative study for small computer supported clearance determination with 131iodine hippuran using CdTe detectors

    With the goal to work out a simple, non-invasive method for the total clearance determination also for immobile patients, we carried out this clearance study with CdTe semi-conductor detectors. The 131iodine hippuran clearance determination was carried out on 69 patients in the nuclear medicine department of the Radiological Policlinic in the framework of a routine diagnosis with ambulant and stationary patients with a gamma camera and a connecting evaluation system. At the same time we recorded the shoulder curves using two CdTe semi-conductor detectors and deposited the data in a portable semi-conductor memory. Next the hypotheses for the routine use with the inclusion of commercially common small computers was worked out. The plasma disappearance curves which were recorded over the shoulder region were evaluated with a small computer according to the method of the modified Oberhausen tables and the Oberhausen formula. (orig./DG)

  14. The influence of tip clearance on performance and internal flow condition of fluid food pump using low viscous fluid

    Fluid machines for fluid food have been used in wide variety of fields i.e. transportation, the filling, and for the improvement of quality of fluid foods. However, flow conditions of it are quite complicated because fluid foods are different from water. Therefore, design methods based on internal flow conditions have not been conducted. In this research, turbo-pumps having a small number of blades were used to decrease shear loss and keep wide flow passage. The influence of the tip clearance was investigated by the numerical analysis using the model with and without the tip clearance. In this paper, the influence of tip clearance on performances and internal flow conditions of turbo-pump using low viscous fluid were clarified by experimental and numerical analysis results. In addition, design methods based on the internal flow were considered. Further, the influences of viscosity on the performance characteristic and internal flow were investigated.

  15. Comparison of clearance determination with 131I-hippurate (split function ERPF) and 99mTc-DMSA

    The capacity of separated kidney function, estimated by means of 131I- or 123I-hippurate clearance, was compared with the capacity results from 99mTC-DMSA scintigraphy. There was found a good correlation (0.98) of the two methods. In patients with urine congestion the frequent high capacity in hippurate clearance in comparison to DMSA-scintigraphy on the affected kidney was evident. This results needs further investigations. In cases where it is necessary to evaluate the relative separated capacity of both sides, the hippurate clearance can be substituted by combination of DMSA-scintigraphy and isotope renogram. Considering surgical consequences, it is important to carry out both methods. (orig.)

  16. The compliance contact model of cylindrical joints with clearances

    Caishan Liu; Ke Zhang; Lei Yang; Keren Wang

    2005-01-01

    This paper is concerned with the determination of the normal force-displacement (NFD) relation for the contact problem of cylindrical joints with clearance. A simple formulation for this contact problem is developed by modeling the pin as a rigid wedge and the elastic plate as a simple Winkler elastic foundation. The numerical results show that the normal displacement relation based on Hertz theory is only valid for the case of large clearance with a small normal load, and the NFD relation based on Persson theory is only effective in the case of very small clearance. The proposed approximate model in this paper gives better results than Hertz theory and Persson theory in a large range of clearances as seen from the comparison with the results of FEM.

  17. IFNL4 affects clearance of hepatitis C virus

    Scientists have discovered a new human interferon gene, Interferon Lambda 4 (IFNL4), that affects clearance of the hepatitis C virus. They also identified an inherited genetic variant within IFNL4 that predicts how people respond to treatment for hepatit

  18. Design Optimization of Ground Clearance of Domestic Cars

    Debojyoti Mitra

    2010-07-01

    Full Text Available Drag and lift forces plays a vital role in the performance and stability of vehicles. Less drag means less fuel consumption and hence less vehicular pollution. Also, lower lift force means higher chance of adhesion of the car body with the ground causing less overturning of the vehicle, which improves the vehicle performance. Both drag and lift forces can be manipulated by varying the ground clearance of the cars. The present study concentrates on studying the effect of ground clearance on these aerodynamic forces experimentally. Wind tunnel studies with a notch-back car model revealed increase in drag and decrease in lift with increase in ground clearance. Therefore, optimization is required for designing the best ground clearance and a preferable value of the same is thus obtained.

  19. Insulin Clearance and the Incidence of Type 2 Diabetes in Hispanics and African Americans

    Lee, C. Christine; Haffner, Steven M.; Wagenknecht, Lynne E.; Lorenzo, Carlos; Norris, Jill M.; Bergman, Richard N.; Stefanovski, Darko; Anderson, Andrea M.; Jerome I Rotter; Goodarzi, Mark O; Hanley, Anthony J.

    2013-01-01

    OBJECTIVE We aimed to identify factors that are independently associated with the metabolic clearance rate of insulin (MCRI) and to examine the association of MCRI with incident type 2 diabetes in nondiabetic Hispanics and African Americans. RESEARCH DESIGN AND METHODS We investigated 1,116 participants in the Insulin Resistance Atherosclerosis Study (IRAS) Family Study with baseline examinations from 2000 to 2002 and follow-up examinations from 2005 to 2006. Insulin sensitivity (SI), acute i...

  20. Insulin Sensitivity and Insulin Clearance are Heritable and Have Strong Genetic Correlation in Mexican Americans

    Goodarzi, Mark O; Langefeld, Carl D.; Xiang, Anny H.; Chen, Yii-Der I.; Guo, Xiuqing; Hanley, Anthony J. G.; Raffel, Leslie J.; Kandeel, Fouad; Thomas A Buchanan; Norris, Jill M.; Fingerlin, Tasha E.; Lorenzo, Carlos; Rewers, Marian J; Haffner, Steven M.; Donald W Bowden

    2014-01-01

    Objective We describe the GUARDIAN (Genetics UndeRlying DIAbetes in HispaNics) consortium, along with heritability estimates and genetic and environmental correlations of insulin sensitivity and metabolic clearance rate of insulin (MCRI). Design and Methods GUARDIAN is comprised of seven cohorts, consisting of 4336 Mexican-American individuals in 1346 pedigrees. Insulin sensitivity (SI), MCRI, and acute insulin response (AIRg) were measured by frequently sampled intravenous glucose tolerance ...

  1. Accelerated clearance of human red blood cells in a rat transfusion model

    Straat, M.; Klei, TRL; de Korte, D; van Bruggen, R.; Juffermans, NP

    2015-01-01

    Background Animal models are valuable in transfusion research. Use of human red blood cells (RBCs) in animal models facilitates extrapolation of the impact of storage conditions to the human condition but may be hampered by the use of cross species. Methods Investigation of clearance and posttransfusion recovery in a rat model using fresh and stored human RBCs. Results Directly following transfusion, human RBCs could be detected in the circulation of all recipients, with higher recovery rates...

  2. Experimental investigation of transonic flow in 2-D model of clearance gap

    Luxa, Martin; Dvořák, Rudolf; Šimurda, David; Vimmr, J.

    Praha: Ústav termomechaniky AV ČR, v. v. i., 2008 - (Příhoda, J.; Kozel, K.), s. 67-70 ISBN 978-80-87012-09-3. [Topical Problems of Fluid Mechanics 2008. Praha (CZ), 20.02.2008-22.02.2008] R&D Projects: GA ČR GA101/07/1508 Institutional research plan: CEZ:AV0Z20760514 Keywords : clearance gap * schlieren method * transonic flow Subject RIV: BK - Fluid Dynamics

  3. Numerical and experimental investigation of transonic flow through 2-D model of clearance gap

    Vimmr, J.; Bublík, O.; Luxa, Martin; Dvořák, Rudolf; Šimurda, David

    Prague: Institute of Thermomechanics AS CR, v. v. i., 2008 - (Fuis, V.; Pásek, M.), s. 1121-1132 ISBN 978-80-87012-11-6. [Engineering Mechanics 2008. Svratka (CZ), 12.05.2008-15.05.2008] R&D Projects: GA ČR(CZ) GA101/08/0623 Institutional research plan: CEZ:AV0Z20760514 Keywords : clearance gap * transonic flow * numerical investigation * experimental investigation * schlieren method Subject RIV: BK - Fluid Dynamics

  4. Manual hyperinflation in airway clearance in pediatric patients: a systematic review

    de Godoy, Vanessa Cristina Waetge Pires; Zanetti, Nathalia Mendonça; Johnston, Cíntia

    2013-01-01

    Objective To perform an assessment of the available literature on manual hyperinflation as a respiratory physical therapy technique used in pediatric patients, with the main outcome of achieving airway clearance. Methods We reviewed articles included in the Lilacs (Latin American and Caribbean Literature on Health Sciences/Literatura Latino Americana e do Caribe em Ciências da Saúde), Cochrane Library, Medline (via Virtual Health Library and PubMed), SciELO (Scientific Electronic Library), an...

  5. Lung cinescintigraphy in the dynamic assessment of ventilation and mucociliary clearance of asbestos cement workers.

    Di Lorenzo, L; Mele, M; Pegorari, M M; Fratello, A; Zocchetti, C; Capozzi, D.

    1996-01-01

    OBJECTIVES: To verify in vivo whether lung cinescintigraphy confirms the effect of asbestos on the patency of the smallest airways and on the efficiency of mucociliary clearance in asbestos cement workers. METHODS: 39 male subjects were examined: 30 asbestos cement workers and nine workers never exposed to occupational respiratory irritants. All subjects had a chest radiograph (International Labour Organisation (ILO) 1980); standard questionnaire on chronic bronchitis; spirometry; arterial bl...

  6. Higher Peritoneal Protein Clearance as a Risk Factor for Cardiovascular Disease in Peritoneal Dialysis Patient

    Chang, Tae Ik; Kang, Ea Wha; Lee, Yong Kyu; Shin, Sug Kyun

    2013-01-01

    Background and Aims Although a number of studies have been published on peritoneal protein clearance (PrCl) and its association with patient outcomes, the results have been inconsistent. Therefore, the intent of this study was to evaluate the impact of PrCl on cardiovascular disease (CVD) and mortality in peritoneal dialysis (PD) patients. Methods This prospective observational study included a total of 540 incident patients who started PD at NHIC Ilsan Hospital, Korea from January 2000 to De...

  7. Effects of PM2 5 exposure on Klebsiella pneumoniae clearance in the lungs of rats

    段争

    2014-01-01

    Objective To investigate the effects of PM2.5 exposure on susceptibility to Klebsiella infection and bacterial clearance,and to discuss its possible mechanisms.Methods Eighty-six healthy male SD rats were randomly divided into 4 groups:a control group,a Klebsiella pneumoniae infection group(infection group),a PM2.5 group and a PM2.5

  8. Nuclear industry practice for clearance of materials, facilities and buildings as well as land. Tutorial; Kaerntekniska industrins praxis foer friklassning av material, lokaler och byggnader samt mark. Handledning

    2011-12-15

    to the radioactive substances carried during the activities. - Description of measuring methods and related technical equipment that can be used in a clearance process. Issues on radiological background in measuring places, detection limits and confidence of measurements are addressed. - Presentation of proposals on routines for clearance, as well as grouping of material flows from a clearance point of view, and discussion on sorting criteria. - Principles for quality assurance and documentation. Detailed directives must be addressed in every company's leading system. - Review on the need of competence for the personnel performing measurements, evaluating results and approving cleared material. Competence profiles for the different roles involved in the clearance process

  9. Increased Glyburide Clearance in the Pregnant Mouse Model

    Zhou, Lin; ZHANG Yi; Hebert, Mary F.; Unadkat, Jashvant D.; Mao, Qingcheng

    2010-01-01

    Glyburide (GLB) is an oral sulfonylurea, commonly used for the treatment of gestational diabetes mellitus. It has been reported that the clearance of GLB in pregnant women is significantly higher than that in nonpregnant women. The molecular mechanism by which pregnancy increases the clearance of GLB is not known, but it may be caused by increased CYP3A activity. Because liver tissue from pregnant women is not readily available, in the present study, we investigated the mechanism of such preg...

  10. The impact for the clearance of dying cells of CRP

    Janko, Christina

    2012-01-01

    An efficient clearance by phagocytes of apoptotic cells is of major importance to avoid secondary necrosis. The leakage of intracellular autoantigens from improperly cleared cells may provoke inflammation and finally autoimmunity. Therefore, the clearance of dying and dead cells is secured by a plethora of soluble adaptor molecules and receptors that recognize apoptotic cell associated molecular patterns (ACAMP) on the surfaces of the target cells. A pattern recognition molecule of the acute ...

  11. A review and comparison of international exemption and clearance levels

    The publication of new European Basic Safety Standards by the European Commission and of new International Basic Safety Standards by the IAEA together with other international agencies, has led to increased interest in the application of the concepts of exemption and clearance. This paper discusses the derivation of radionuclide-specific exemption and clearance values for application in various areas of the regulation of radioactive materials. (author)

  12. Early Agriculture: Land Clearance and Climate Effects

    Ruddiman, W. F.

    2013-12-01

    inception. Well-dated high-resolution CO2 (and CH4) records from ice cores show gas decreases that correlate closely with major pandemics and civil strife, but show little if any link to temperature or precipitation trends. One significant (and intriguing) discrepancy with the original hypothesis remains. Most of the CO2 rise occurred between 6000 and 2500 years ago, well before the major increase in global population that has been hindcast from geometric models that assume a constant fractional rate of population increase. Some of this discrepancy has been reconciled by historical evidence showing much higher per-capita clearance millennia ago than later in pre-industrial time, resulting in disproportionately large early clearance and CO2 emissions. In addition, DNA studies and archeological syntheses now indicate that early farming populations initially grew at very fast rates favored by environments rich in basic resources (especially fertile soils), but then slowed in later millennia because of growing resource limitations and the effects of pandemics and civil strife in checking population growth. This emerging view of fast-rising early population trends has the potential to account for the early timing of the CO2 increase.

  13. Urinary and metabolic clearances of arginine vasopressin in normal subjects

    Synthetic arginine vasopressin (AVP) was infused into 11 hydrated normal subjects at five different infusion rates ranging from 10 to 350 μU kg-1 min-1. Each infusion rate was continued for 1 h, and urinary determinations were made on the 30- to 60-min specimens during which time there was no further rise in plasma AVP. Urinary AVP concentrations (μU/ml) and excretion rates (μU/min) increased linearly with increasing infusion rates, and the concentration of AVP in urine increased 120 times more rapid than plasma. Urinary and metabolic clearances of AVP also increased linearly with the maximum urinary clearance being 60.6% of the creatinine clearance. The total metabolic clearance of AVP (including urinary clearance) was 17.8 times that of the urinary clearance of AVP alone. These data clarify the relationships between plasma and urinary AVP in normal hydrated subjects during AVP infusion under steady-state conditions and emphasize the potential advantage of measuring urinary AVP as a monitor of endogenous AVP secretion. AVP was measured by radioimmunoassay

  14. A high sensitivity inductive sensor for blade tip clearance measurement

    A multiplexed inductive sensor consisting of multiple mini-sized planar spiral coils for detecting multiple tip clearances of rotor blades is presented. The sensor measures the tip clearances by monitoring the inductance changes of planar spiral coils caused by the passage of the rotor blades. A resonance frequency division multiplexing technique and parallel LC resonance measurement were applied to the multiple sensor coils, making it feasible to measure multiple tip clearances using only one set of measurement electronics with high sensitivity and resolution. The results from tests conducted on a bench-top test rig have demonstrated that the sensor is capable of simultaneously measuring multiple tip clearances from 0 to 5 mm with a 10 μm resolution at a high rotary speed up to 80 000 RPM. With its high resolution, high sensitivity and capability of monitoring a large number of tip clearances simultaneously, this sensor can potentially be used for advanced active tip clearance control in turbine machinery. (papers)

  15. Model of mucociliary clearance in cystic fibrosis lungs.

    Kurbatova, P; Bessonov, N; Volpert, V; Tiddens, H A W M; Cornu, C; Nony, P; Caudri, D

    2015-05-01

    Mucus clearance is a primary innate defense mechanism in the human airways. Cystic fibrosis (CF) is a genetic disease caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) protein. CF is characterized by dehydration of airway surface liquid and impaired mucociliary clearance. As a result, microorganisms are not efficiently removed from the airways, and patients experience chronic pulmonary infections and inflammation. We propose a new physiologically based mathematical model of muco-ciliary transport consisting of the two major components of the mucociliary clearance system: (i) periciliary liquid layer (PCL) and (ii) mucus layer. We study mucus clearance under normal conditions and in CF patients. Restoring impaired clearance of airway secretions in one of the major goals of therapy in patients with CF. We consider the action of the aerosolized and inhaled medication dornase alfa, which reduces the viscosity of cystic fibrosis mucus, by selectively cleaving the long DNA strands it contains. The results of the model simulations stress the potential relevance of the location of the drug deposition in the central or peripheral airways. Mucus clearance was increased in case the drug was primarily deposited peripherally, i.e. in the small airways. PMID:25746843

  16. Lithium clearance and renal tubular sodium handling during acute and long-term nifedipine treatment in essential hypertension

    Bruun, N E; Ibsen, H; Skøtt, P; Toftdahl, D; Giese, J; Holstein-Rathlou, N H

    1988-01-01

    1. In two separate studies the lithium clearance method was used to evaluate the influence of acute and long-term nifedipine treatment on renal tubular sodium reabsorption. 2. In the acute study, after a 4 week placebo period two doses of 20 mg of nifedipine decreased supine blood pressure from 155....../101 (20.6/13.5) +/- 11/4 (1.5/0.5) to 139/88 (18.5/11.7) +/- 16/9 (2.1/1.2) mmHg (kPa) (means +/- SD; P less than 0.01). Lithium clearance, glomerular filtration rate and sodium clearance did not change. Therefore the calculated values of absolute proximal and absolute distal sodium reabsorption rates...... reabsorption did not change. Sodium clearance, fractional sodium excretion, potassium clearance, plasma volume and extracellular fluid volume were also unchanged. 4. In conclusion, we found no changes of renal tubular sodium reabsorption during acute nifedipine treatment, whereas long-term nifedipine treatment...

  17. Importance of different clearance options for the dismantling of the NPP Stade (KKS)

    As a consequence of the IAEA-Safety Guide RS-G 1.7 is an adaption of the clearance level in European and national German law in preparation. This paper analyse the effect of the different clearance levels of the realisation of the clearance, especially if some conditioned clearance according to German law will not exist further more. (orig.)

  18. Stochastic model of ultrafine particle deposition and clearance in the human respiratory tract

    Deposition and clearance of insoluble ultrafine particles, ranging from 1 to 100 nm, were simulated by stochastic models using Monte Carlo methods. Brownian motion is the dominant mode of deposition in human airways. The additional effects of convective diffusion in bifurcations and axial diffusion (convective mixing) primarily affect particle transport and deposition of particles in the 1-10 nm range. Regarding total deposition, the effects of both convective mechanisms are practically compensated by the concomitant effect of molecular radial diffusion (Brownian motion). During the first hours following inhalation, 1 nm particles are predicted to be cleared much faster than particles in the size range from 10 to 100 nm, with a retained fraction of about 80% after 24 h. For 1-10 nm particles, extracellular transfer to blood is the most likely mode of clearance, while uptake and subsequent accumulation in epithelial cells are assumed to be the preferential mechanisms for 10-100 nm particles. (author)

  19. Rapid and efficient clearance of blood-borne virus by liver sinusoidal endothelium.

    Latha P Ganesan

    2011-09-01

    Full Text Available The liver removes quickly the great bulk of virus circulating in blood, leaving only a small fraction to infect the host, in a manner characteristic of each virus. The scavenger cells of the liver sinusoids are implicated, but the mechanism is entirely unknown. Here we show, borrowing a mouse model of adenovirus clearance, that nearly all infused adenovirus is cleared by the liver sinusoidal endothelial cell (LSEC. Using refined immunofluorescence microscopy techniques for distinguishing macrophages and endothelial cells in fixed liver, and identifying virus by two distinct physicochemical methods, we localized adenovirus 1 minute after infusion mainly to the LSEC (∼90%, finding ∼10% with Kupffer cells (KC and none with hepatocytes. Electron microscopy confirmed our results. In contrast with much prior work claiming the main scavenger to be the KC, our results locate the clearance mechanism to the LSEC and identify this cell as a key site of antiviral activity.

  20. Dynamic load sharing behavior of transverse-torsional coupled planetary gear train with multiple clearances

    盛冬平; 朱如鹏; 靳广虎; 陆凤霞; 鲍和云

    2015-01-01

    A new nonlinear transverse-torsional coupled model with backlash and bearing clearance was proposed for planetary gear set. Meanwhile, sun gear and planet’s eccentricity errors, static transmission error, and time-varying meshing stiffness were taken into consideration. The differential governing equations of motion were solved by employing variable step-size Rung-Kutta numerical integration method. The behavior of dynamic load sharing characteristics affected by the system parameters including input rate, sun gear’s supporting stiffness and eccentricity error, planet’s eccentricity error, sun gear’s bearing clearance, backlashes of sun-planet and planet-ring meshes were investigated qualitatively and systematically. Some theoretical results are summarized at last which extend the current understanding of the dynamic load sharing behavior of planet gear train, enrich the related literature and provide references for the design of planetary gear train.

  1. The influence of rotationally symmetric casing contours on the rotor tip clearance flow; Beeinflussung von Rotorspaltstroemungen durch rotationssymmetrische Gehaeusekonturen

    Kroeger, Georg Philipp

    2010-07-01

    This thesis presents a method to reduce the tip clearance losses in compressor rotors by a wave-like casing contour. The approach is explained on the basis of a simple optimization example. The aerodynamic effects of the casing contour on the clearance flow and the clearance vortex are shown and discussed. A pressure potential is created by the interaction of the axial flow component with the wavy casing shape, which changes the formation and the development of the leakage vortex essentially. The theory of the rotationally symmetric casing contour is established and discussed with the help of a one dimensional incompressible Rankine vortex model. Further examples show the optimized casing contour for rotor blades with higher inflow Mach numbers and for a combined optimization of the casing shape and the blade tip airfoil section. Finally, the combined design approach is successfully applied to an entire Siemens compressor model. (orig.)

  2. Modelling the Rough Piston Skirts EHL at a Small and a Large Radial Clearance in the Initial Engine Start Up

    M. Gulzar

    2013-12-01

    Full Text Available At initial engine start-up, the low speeds take time to develop considerable film thickness between piston and liner surfaces. Factors like radial clearance, oil viscosity and roughness of interacting surfaces play an important role in this regard. A two dimensional model is presented for hydrodynamic lubrication and EHL of rough piston skirt under isothermal conditions. Flow factors method is used to incorporate the deterministic isotropic roughness effects in Reynolds’ equation and Greenwood-Tripp asperity contact model is used for involving the corresponding asperity contact forces and moments. The numerical model is used to get simulation results including piston eccentric displacements, hydrodynamic and EHL film thickness and rising pressures for 10 micron and 100 micron radial clearance between piston and liner. All results are plotted against 720 degree crank rotation cycle. The results show considerable change in each parameter by changing radial clearance from small value to large.

  3. Persistence, clearance and reinfection regarding six high risk human papillomavirus types in Colombian women: a follow-up study

    Soto de León, Sara; Río Ospina, Luisa del; Camargo, Milena; Sánchez, Ricardo; Moreno Pérez, Darwin Andrés; Pérez Prados, Antonio; Patarroyo, Manuel Elkin; Patarroyo, Manuel Alfonso

    2014-01-01

    Background: The design of new healthcare schemes which involve using molecular HPV screening means that both persistence and clearance data regarding the most prevalent types of HR-HPV occurring in cities in Colombia must be ascertained. Methods: This study involved 219 HPV positive women in all of whom 6 types of HR-HPV had been molecularly identified and quantified; they were followed-up for 2 years. The Kaplan-Meier survival function was used for calculating the time taken for the clearanc...

  4. Non-cytolytic antigen clearance in DNA-vaccinated mice with electropotation

    Jin-liang PENG; Yong-gang ZHAO; Jun-hua MAI; Wen-ka PANG; Wei GUO; Guang-ming CHEN; Guo-yu MO; Gui-rong RAO; Yu-hong XU

    2007-01-01

    Aim: To explore the potential of electroporation (EP)-mediated hepatitis B virus (HBV) DNA vaccination for the treatment of chronic HBV infection. Methods: BALB/c mice were vaccinated with HBV DNA vaccine encoding for the HBV preS2-S antigen, combined with or without EP. HBV surface antigen expression plasmid was administered into mice liver via a hydrodynamic injection to mimic HBV infection. The clearance of antigen in the serum and liver was detected by ELISA assay and immunohistochemical staining. The histopathology of the liver tissues was examined by HE staining and serum alanine aminotransferase assay.Results: The immunogenicity ofHBV DNA vaccine encoding for the HBV preS2-S antigen can be improved by EP-mediated vaccine delivery. The elicited immune responses can indeed reduce the expression of HBV surface antigen (HBsAg) in hepatocytes of the mouse model that was transfected to express HBsAg using the hydrodynamic injection method. The antigen clearance process did not cause significant toxicity to liver tissue, suggesting a non-cytolytic mechanism. Conclusion: The EP-aided DNA vaccination may have potential in mediating viral clearance in chronic hepatitis B patients.

  5. How important is gametocyte clearance after malaria therapy?

    Karunajeewa, Harin A; Mueller, Ivo

    2016-01-01

    There has been increasing interest in the role of malaria drugs in preventing malaria transmission from humans to mosquitoes, which would help augment malaria control and elimination strategies. Nevertheless, only one stage in the malaria parasite life cycle, the gametocyte, is infectious to mosquitoes. The Worldwide Antimalarial Resistance Network (WWARN) have analyzed data from 48,840 patients from 141 clinical trials in order to define the nature and determinants of gametocyte clearance following artemisinin combination treatment (ACT) for symptomatic malaria infections. However, the presence of gametocytes does not always predict their infectivity, meaning that the microscopy-based methods used by the WWARN investigators represent an imperfect surrogate marker of transmissibility. Their findings, that some ACTs clear gametocytes faster than others, should be interpreted in light of these limitations and important gaps in our understanding of the biology and epidemiology of malaria transmission.Please see related article: https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-016-0621-7. PMID:27317420

  6. Radiosensitisation in normal tissues with oxygen, carbogen or nicotinamide: therapeutic gain comparisons for fractionated x-ray schedules

    Methods: Radiosensitisation with oxygen, carbogen or nicotinamide alone and oxygen or carbogen combined with nicotinamide was compared in early and late responding normal tissues in rodents. X-ray treatments were delivered as single doses or fractionated schedules of 2 fractions in 1 day, 2, 12 and 36 fractions in an overall time of 12 days and 10 fractions in 5 or 12 days. Acute skin reactions, survival of intestinal crypts, breathing rate, reduction in the packed red-cell volume and clearance of 51Cr-EDTA were used as assays of epidermal, gut, lung and renal damage. Results: Relative to air-breathing mice, carbogen or oxygen produced a small, and not always significant, increase in sensitivity (enhancement ratios ≤ 1.15) in gut, lung and kidneys; however, in skin a dose enhancement of 1.2-1.3 was observed. The effect of nicotinamide in air, carbogen or oxygen was studied only in lung and gut. The drug produced variable but generally significant increases in radiosensitisation (≤ 1.26) in all three gases. Relative to treatments in air, enhancement ratios for nicotinamide alone were usually slightly higher than those observed when either carbogen or oxygen were administered without the drug. With all three modifiers (i.e. oxygen, carbogen, nicotinamide alone or for the drug-gas combinations) there was no significant change in the enhancement ratios observed as the number of radiation dose fractions was varied. Conclusions: Comparisons with fractionated X-ray studies done previously in rodent tumours indicate that a therapeutic benefit, relative to lung, gut and renal damage, would be observed with oxygen or carbogen alone but not with nicotinamide alone. The greatest gain would be achieved with the combination of carbogen and nicotinamide, with which a benefit was observed even relative to epidermal damage. These results indicate that some decrease in normal tissue tolerance could be observed when using these modifiers in clinical radiotherapy and, although

  7. Evaluation of 2 amino acid protocols for kidney protection in patients treated with 90Y-DOTATOC for neuroendocrine tumors

    Full text of publication follows. Background: peptide receptor radionuclide therapy (PRRT) is an established treatment for progressive neuroendocrine tumours (NET). Nephrotoxicity is the limiting factor using 90Y-DOTATOC. Although administration of amino acids lowers the radioactive dose to the kidneys, delayed renal damage is a concern following therapy. Studies have indicated that prolonging the infusion of amino acids offers improved kidney protection. The intermittent infusion of amino acids up two days after PRRT has also been shown to further reduce renal uptake of radioactivity in pilot studies. Aim: We evaluated whether differences could be detected in GFR in patients treated with two different protocols for kidney protection using commercially available (Vamin-18) amino acid mixture (AAM); a standard protocol with 2 litres of AAM infused over 4 hours or a 24-hour infusion protocol with 3 litres of AAM. Material and method: GFR in 18 patients treated with infusion of 2 litres AAM of 4 hours was compared with GFR in 13 patients treated with 3 litres of AAM over 24 hours at 3 months, 6 months and 12 months after therapy with 90Y DOTATOC. The majority of patients received the standard treatment of 3.7 GBq/m2 90Y DOTATOC every 8-10 weeks. The glomerular filtration rate (GFR) was estimated using the 51Cr-EDTA plasma clearance by a single sample technique according to Groth and Aasted. Results: pre-existing risk factors associated with kidney failure were seen in 84 % of the patients. Other identified risk factors associated with kidney failure were former treatment with 90Y-DOTATOC and/or chemotherapy, hypertension and diabetes. In the whole group of patients a significant fall in renal function was seen up to twelve months after PRRT. The median loss of kidney function was 30 ml/min/1.73m2 (27 %) 12 months after treatment compared to pre-therapeutic values. Although no significant statistical difference was found comparing the two amino acid protocols, the use

  8. A 3-marker index improves the identification of iron disorders in CKD anaemia.

    Lucile Mercadal

    Full Text Available BACKGROUND: Iron disorders are common and complex in chronic kidney disease (CKD. We sought to determine whether a 3-marker index would improve the classification of iron disorders in CKD anaemia. METHODS: We studied the association between Hb level and iron indexes combining 2 or 3 of the following markers: serum ferritin (<40 ng/mL, transferrin saturation (TSAT<20% and total iron binding capacity (TIBC<50 µmol/L in 1011 outpatients with non-dialysis CKD participating in the Nephrotest study. All had glomerular filtration rates measured (mGFR by (51Cr-EDTA renal clearance; 199 also had hepcidin measures. RESULTS: The TSAT-TIBC-ferritin index explained Hb variation better than indexes combining TSAT-TIBC or ferritin-TSAT. It showed hypotransferrinaemia and non-inflammatory functional iron deficiency (ID to be more common than either absolute or inflammatory ID: 20%, 19%, 6%, and 2%, respectively. Hb was lower in all abnormal, compared with normal, iron profiles, and decreased more when mGFR was below 30 mL/min/1.73 m(2 (interaction p<0.0001. In patients with mGFR<30 mL/min/1.73 m(2, the Hb decreases associated with hypotransferrinaemia, non-inflammatory functional ID, and absolute ID were 0.83±0.16 g/dL, 0.51±0.18 and 0.89±0.29, respectively. Compared with normal iron profiles, hepcidin was severely depressed in absolute ID but higher in hypotransferrinaemia. CONCLUSIONS: The combined TSAT-TIBC-ferritin index identifies hypotransferrinaemia and non-inflammatory functional ID as the major mechanisms of iron disorders in CKD anaemia. Both disorders were associated with a greater decrease in Hb when mGFR was <30 mL/min/1.73 m(2. Taking these iron profiles into account may be useful in stratifying patients in clinical trials of CKD anaemia and might improve the management of iron therapy.

  9. Results of active cycle of breathing techniques and conventional physiotherapy in mucociliary clearance in children with cystic fibrosis

    Hristara-Papadopoulou, A; Tsanakas, J

    2007-01-01

    Aim: The aim of the present study is the comparison of the results of the appliance of two methods of respiratory physiotherapy; the active cycle of breathing techniques in drainage positions and the conventional physiotherapy, regarding their effects on mucociliary clearance in patients with cystic fibrosis.

  10. Using the same harvester head for undergrowth pre-clearance and fuel wood harvesting; Ennakkoraivaus ja energiapuun hakkuu samalla laitteella

    Rieppo, K.; Mutikainen, A.

    2011-07-01

    TTS conducted a study on the profitability of undergrowth pre-clearance, which was carried out using the Risutec L3A harvesting head in conjunction with fuel wood harvesting. The experiments were implemented on two sites; one was dominated by birch and the other by pine. On the first site, the productivity level when using the method of pre-clearance with the felling device in conjunction with fuel wood harvesting was even better than the approach where the lumberman had carried out the pre-clearance. On the pine-dominated site, the productivity level of fuel wood harvesting was higher in the method where the lumberman carried out pre-clearance. Once the preclearance expenses had been added to the fuel wood harvesting expenses, the total unit expenses of the two methods were unit expenses of the two methods were nearly similar for this site as well. Based on the results, it is likely that on some sites, it is already feasible to use the investigated device for carrying out preclearance in conjunction with fuel wood harvesting. (orig.)

  11. Prognostic significance of early lactate clearance rate for severe acute respiratory failure patients on extracorporeal membrane oxygenation

    臧芝栋

    2014-01-01

    Objective To investigate the prognostic significanceof early lactate clearance rate for severe acute respiratory failure patients on extracorporeal membrane oxygenation(ECMO).Methods Forty-three patients with severe acute respiratory failure supported by venous-venous(v-v)ECMO were enrolled from January 2007 to January 2013.Arterial blood lactate at pre-ECMO support(0 h)and at

  12. Approaches towards establishing of clearance levels in Japan

    It is important to establish necessary regulatory systems for decommissioning waste management, especially to establish clearance levels from regulatory control. To establish the regulatory systems, the Nuclear Safety Commission (NSC) has been discussing the unconditional clearance levels for materials from nuclear reactors since May 1997. The NSC tries to derive unconditional clearance levels for the materials such as concrete and ferrous metal, arising from nuclear reactor decommissioning. In the derivation, both disposal and recycle/reuse of the materials are considered. Typical scenarios and parameter values for dose estimation are selected considering the Japanese natural and social conditions. Preliminary clearance levels were derived from 10 μSv/yr of individual dose criterion and deterministic analysis. For most radionuclides, the preliminary results are the same order of magnitude recommended in IAEA-TECDOC-855. Some radionuclides such as β emitters, however, are different order of magnitude from those recommended in IAEA-TECDOC-855. It is necessary that international organizations lead the discussions on the clearance levels to conclude final consensus. (author)

  13. Relevant aspects in the application of exemption and clearance criteria

    Full text: Nowadays the relevant question in the Radiological Protection is the necessity of the establishment of criteria to remove materials (scrap) from the regulatory control. In 1996, the International Atomic energy Agency -IAEA published the International Basic Safety Standards for Protection Against Ionizing Radiation and for the Safety of Radiation Sources- the BSS-115, which establishes the requirements for exclusion, exemption and clearance for practices, sources, materials and pieces. The BSS's criteria were established in terms of effective dose and the collective effective dose committed expected to be incurred by any member of the public due to practices or sources that will be free from regulatory control (exemption) or a material that will be removed from authorized practices (clearance). In order to become easy to implement these criteria, in the Schedule I of BSS were established exemption levels specified in activity concentration or activity for several radionuclides. These levels that would give rise to doses to appropriate critical groups that correspond to the dose criteria for the exemption of practices. In Brazil the regulatory authority, Comissao Nacional de Energia Nuclear - CNEN, published in 2005 The Basic Guidelines for Radiological Protection, the CNEN-NN-3.01, incorporating BSS's concepts and criteria for exemption and clearance. However, in the practical implementations of this guidelines during the practices licensing and inspections activities were verified the necessity of clearance criteria in terms of superficial activity, for become accomplishable to implement the monitoring process of pieces and materials (scrap) before remove that from regulatory control (clearance). (author)

  14. Radioactive Aerosols in the Clinical Study of Pulmonary Clearance

    The study of pulmonary clearance mechanisms has acquired particular importance owing to the growing pollution of the environment and to the increasing incidence and seriousness of cases of pneumoconiosis. Such research is particularly important in radiopathology because of the frequent occurrence of respiratory radioactive contamination. The authors' aim is to tackle this problem and in particular to study long-term clearance mechanisms. Before starting this work, however, they propose to determine the contamination parameters as accurately as possible. For this purpose they plan to study respiratory function in normal subjects by administering labelled aerosols with well-defined physico-chemical characteristics; the first stage of the investigation is then to observe the kinetics of fixation and clearance in the short term. They describe the installations used for this voluntary contamination which must provide a means of producing the aerosols and administering them in controlled amounts and must also ensure efficient protection of the operators against irradiation arid contamination. The choice of the aerosols is also discussed: this is governed mainly by the nature of the vectors, the particle size and the physical characteristics of the tracers. Finally, the authors outline the detection and measuring techniques which they are using to study contamination kinetics, evaluate contamination burdens and follow the short-term clearance. These data constitute a preliminary basis for the study of long-term clearance. (author)

  15. ELMO1 signaling in apoptotic germ cell clearance and spermatogenesis.

    Elliott, Michael R; Ravichandran, Kodi S

    2010-10-01

    Apoptosis and the subsequent removal of dying cells are crucial processes for tissue development and maintenance. Although we are beginning to understand the signaling pathways that control the phagocytic clearance of apoptotic cells, the physiological relevance of these pathways is lacking. During spermatogenesis, over half of the developing germ cells eventually die by apoptosis, yet the signaling pathways that regulate the phagocytic clearance of these dying cells or the impact of this clearance on development and maintenance of the germ cell population is not well understood. The ELMO1/Dock180 proteins form an evolutionarily conserved signaling module that functions as a bipartite guanine nucleotide exchange factor for the small GTPase Rac. The subsequent Rac-dependent cytoskeletal changes play an important role in the physical engulfment of apoptotic cells. Recent findings demonstrate an in vivo role for ELMO1-dependent clearance in the testes, with implications for spermatogenesis. Here we will discuss the role of apoptotic cell clearance during spermatogenesis, with a particular emphasis on ELMO1/Dock180 signaling. PMID:20958313

  16. Investigation on the Dynamic Performance of the Tripod-Ball Sliding Joint with Clearance in a CRANK-SLIDER Mechanism. Part 1. Theoretical and Experimental Results

    JIA, X.; JIN, D.; JI, L.; ZHANG, J.

    2002-05-01

    Clearance is inevitable in the kinematic joints of mechanisms. In this paper, the dynamic behavior of a crank-slider mechanism with clearance in its tripod-ball sliding joint is investigated theoretically and experimentally. The mathematical model of this new-type of joint is established, and the new concepts of basal system and active system are put forward. Based on the mode-change criterion established in this paper, the consistent equations of motion in full-scale are derived by using Kane method. The experimental rig was set up to measure the effects of the clearance on the dynamic response. The dynamic responses including additional motion, input torque and acceleration have been obtained, and the effects of the clearance size and driving speed have also been investigated by both analytical and experimental means. Corresponding experimental studies verify the theoretical results satisfactorily.

  17. Role of plaque in the clearance of salivary sucrose and its influence on salivary ph

    A Kumar

    2011-01-01

    Full Text Available Background: The prevalence of dental caries in children, in India, is higher than many of the industrialized countries. The sugar most commonly associated with dental caries is sucrose, as the microorganisms in the dental plaque have the ability to convert this dietary constituent into various organic acids. Aims and Objectives: This study was conducted to study the effect of the presence of plaque on the salivary clearance of sucrose and to study the effect of the presence of plaque on salivary pH, following sucrose clearance. Materials and Methods: Salivary sucrose determination was done by using the anthrone technique. A Digital MHOS pH meter estimated the salivary pH. Results: Presence of plaque increased the salivary sucrose clearance time and decreased the salivary pH at various time intervals. Conclusions: The microbial etiology of dental caries is the dynamic relationship among the dental plaque microbiota, dietary carbohydrates, saliva and pH lowering, and the cariogenic potential of the dental plaque. Caries occur preferentially in the dentition sites characterized by high exposure to carbohydrate and diminished salivary effect.

  18. Clearance and recycling - how can radiation protection and application of the waste hierarchy be optimised?

    In this paper, the principles behind the current Swedish regulations for clearance of materials and for application of the waste hierarchy on radioactive waste are described and discussed. As a background, the applicable legislation for radiation protection and nuclear safety is briefly described and compared with the environmental legislation for waste management. The possibilities for a simultaneous optimisation of radiation protection, waste management and sustainability are analysed. As part of this, different factors to be considered in the optimisation of waste management in the context of clearance and recycling are presented and discussed. Examples of such factors are: possibilities of waste segregation, availability and acceptability of routes for recycling or disposal, availability of methods for radiological characterisation, predicted or potential radiation doses to members of the public, predicted or potential spread of radioactive substances in the environment, costs and material value. As an illustration, some examples on the use of the clearance option in the Swedish nuclear industry are presented, both from operation and decommissioning of nuclear facilities. Concluding remarks are made from a radiation protection regulatory perspective. (authors)

  19. Repetitive,Low—dose Tissue Plasminogen Activator for Clearance of Experimental Vitreous Hemorrhage

    PeiquanZhao; WenjiWang

    1995-01-01

    Purpose:To investigate the effectiveness of repetitve,low-dose tPA for clearance of experimental vitreous hemorhage,Methods:The model vitreous hemorrhage was produced by intravitreal injection of 0.05ml of autologous citrated whole blood in 14rabbits(28eyes).One week after the creation of vitreous hemorrhage,the eyes were randomly separated into 3groups.Groups 1and 2received two injections of 5or 25μg of tPA,respective-ly,with one injection in a7-day interval.Group 3reeived two injections of PS in thesame way.Results;The clearance of vitreous hemorrhage in rPA-treated groups was signifi-cantly faster than that in the control group(P<0.05,orP<0.01).However,there was no statistically significant difference between the two tPA-treated groups.Not any retinal toxicity was detected by ERG,light microscopy,and transmission electron microscopy examinations.Conclusions:repetitive injections of low-dose tPA were effective in the treatment of experimental vitreous hemorrhage.Whether it is effective on the clearance of vitreous hemorrhage in human eyes needs further investigation.

  20. FGF21-Mediated Improvements in Glucose Clearance Require Uncoupling Protein 1

    Michelle M. Kwon

    2015-11-01

    Full Text Available Fibroblast growth factor 21 (FGF21-mediated weight loss and improvements in glucose metabolism correlate with increased uncoupling protein 1 (Ucp1 levels in adipose tissues, suggesting that UCP1-dependent thermogenesis may drive FGF21 action. It was reported that FGF21 is equally effective at reducing body weight and improving glucose homeostasis without UCP1. We find while FGF21 can lower body weight in both wild-type and Ucp1 knockout mice, rapid clearance of glucose by FGF21 is defective in the absence of UCP1. Furthermore, in obese wild-type mice there is a fall in brown adipose tissue (BAT temperature during glucose excursion, and FGF21 improves glucose clearance while preventing the fall in BAT temperature. In Ucp1 knockout mice, the fall in BAT temperature during glucose excursion and FGF21-mediated changes in BAT temperature are lost. We conclude FGF21-mediated improvements in clearance of a glucose challenge require UCP1 and evoke UCP1-dependent thermogenesis as a method to increase glucose disposal.

  1. Nonlinear Dynamics Behaviors of a Rotor Roller Bearing System with Radial Clearances and Waviness Considered

    Wang Liqin; Cui Li; Zheng Dezhi; Gu Le

    2008-01-01

    A rotor system supported by roller bearings displays very complicated nonlinear behaviors due to nonlinear Hertzian contact forces, radial clearances and bearing waviness. This paper presents nonlinear bearing forces of a roller bearing under four-dimensional loads and establishes 4-DOF dynamics equations of a rotor roller bearing system. The methods of Newmark-β and of Newton-Laphson are used to solve the nonlinear equations. The dynamics behaviors of a rigid rotor system are studied through the bifurcation, the Poincar bility caused by the quasi-periodic bifurcation, the periodic-doubling bifurcation and chaos routes as the rotational speed increases.Clearances, outer race waviness, inner race waviness, roller waviness, damping, radial forces and unbalanced forces-all these bring a significant influence to bear on the system stability. As the clearance increases, the dynamics behaviors become complicated with the number and the scale of instable regions becoming larger. The vibration frequencies induced by the roller bearing waviness and the orders of the waviness might cause severe vibrations. The system is able to eliminate non-periodic vibration by reasonable choice and optimization of the parameters.

  2. Comparison of clearance and arteriovenous extraction techniques for measurements of renal hemodynamic functions

    No previous studies have directly compared timed urine collections (UV/P) vs. arteriovenous (A-V) extraction methods for determination of renal function in whole kidney preparations. We examined different markers and techniques for assessing renal plasma flow (RPF), filtration fraction (FF), and glomerular filtration rate (GFR) in both steady-state and rapidly changing conditions following 2 ml/kg bolus intravenous injections of either Renografin 76% (meglumine/sodium diatrizoate-76%) or hypertonic mannitol 25%. During steady-state conditions, excellent correlations were obtained when comparing markers and techniques. Thus, timed urinary clearances of inulin vs. 99m-technetium DTPA (Tc) had a correlation coefficient (R) of .96 (P less than .01; n = 16), and the A-V extraction technique of inulin vs. Tc as determinants of GFR showed a correlation of R = .98 (P less than .01; n = 15). The timed urinary clearance of inulin vs. the A-V extraction of inulin for glomerular filtration gave a correlation of R = .93 (P less than .01; n = 15). The clearance of para-aminohippurate (PAH) divided by the extraction of PAH vs. flow determinations using the electromagnetic flowmeter gave a correlation of R = .92 (P less than .01; n = 16). The anticipated decrease in GFR following contrast medium and hypertonic mannitol was observed using the A-V extraction technique, whereas an artifactual, exaggerated increase in GFR was observed using the timed urine collection technique. Similarly, we noted an exaggerated increase in RPF using CPAH/EPAH as the methodology. We conclude that rapid changes in renal hemodynamics may be measured accurately using the A-V extraction technique but not with clearance techniques requiring timed urine collections

  3. THE EFFECT OF NORMAL SALINE AND 3.5% HYPERTONIC SALINE ON MUCOCILIARY CLEARANCE IN SINUSITIS

    Mahesh

    2014-10-01

    Full Text Available Introduction: Sinusitis is usually treated with antibiotics, decongestants, mucolytics and steroids. Long term use of these drugs has many side effects. This has led to the use of other modalities of treatment such as saline nasal irrigation. Saline nasal irrigation helps in clearance of secretions, debris and crusts, thus improving the mucociliary clearance. OBJECTIVE: This randomized comparative study was undertaken to assess the ciliary function by performing saccharine test and to evaluate the effect of 3.5% hypertonic saline nasal drops against normal saline nasal drops on mucociliary transit time of saccharine. MATERIALS AND METHODS: Fifty patients diagnosed as chronic sinusitis in the age group of 18 to 45 years were randomized into two groups; Group A treated with 0.9% normal saline and Group B with 3.5% hypertonic saline for a period of 4 weeks. Mucociliary transit time was recorded by performing saccharine test before and after treatment. RESULTS: Significant improvement was seen in both the groups but when compared to normal saline, hypertonic saline significantly improved the mucociliary clearance. The mean mucociliary transit time of saccharine in Group A patients before treatment was 19.860 minutes and after treatment was 17.634 minutes (t=14.012, p=0.0001. The mean mucociliary transit time of saccharine in Group B patients before treatment was 21.881 minutes and after treatment was 16.689 minutes (t=14.662, p=0.0001. All the patients reported relief of symptoms, but relief was much earlier in Group B when compared to Group A. Mild burning sensation in the nose and throat was reported by 4% of patients in Group A and 8% in Group B. CONCLUSION: Both 0.9% normal saline and 3.5% hypertonic saline significantly improved the mucociliary clearance. Hypertonic saline is more efficacious than normal saline in the treatment of chronic sinusitis

  4. Morphology of renal pelvis and clearance of lower pole stones following ESWL

    Bogdanović Jovo

    2003-01-01

    Full Text Available Introduction and objective A prerequisite for successful outcome of extracorporeal shock wave lithotripsy (ESWL is effective stone fragmentation. Despite successful stone fragmentation, complete clearance of stone fragments cannot be achieved patient, due to various factors. The aim of this prospective study was to determine morphological factors that affect clearance following successful stone fragmentation by ESWL. Material and methods In the period October 1999 and January 2001, 60 patients (45 male and 15 female with single lower pole kidney stones have been treated using lithotripter Lithostar 2000TM. Parameters of radiographic anatomy, measured on intravenous pyelography, included infundibular width and length, infundibuloureteral infundibulopelvic angles. After the follow-up period of 3 months, patients were divided into two groups regarding clearance status: Group I consisted of stone free patients, and group II of those with residual fragments. Results Average values of measured parameters in group I vs group II were as follows: infundibular length 27.70±5.48 mm vs 30.25±3.95mm (p=0.045, Mann-Whitney test; infundibular width 5.98±3.28 mm vs 4.70±1.30 mm (p=0.018, Mann-Whitney test; infundibulopelvic angle 52.92±20.76o vs 34.10±8.19o (p=0.00001, Mann-Whitney test; infundibuloureteral angle 48.00±21.13o vs 30.70±7.49o (p=0.00001, Mann-Whitney test. Conclusion This study revealed that parameters of infundibulopelvic anatomy were significantly different in the examined groups. The success of clearance of fragments following ESWL procedure can be predicted using these morphologic parameters.

  5. Direct measurement of first-pass ileal clearance of a bile acid in humans

    The purpose of this study was to develop and validate a method of directly measuring ileal bile acid absorption efficiency during a single enterohepatic cycle (first-pass ileal clearance). This has become feasible for the first time because of the availability of the synthetic gamma-labeled bile acid 75Selena-homocholic acid-taurine (75SeHCAT). Together with the corresponding natural bile acid cholic acid-taurine (labeled with 14C), SeHCAT was infused distal to an occluding balloon situated beyond the ampulla of Vater in six healthy subjects. Completion of a single enterohepatic cycle was assessed by obtaining a plateau for 75SeHCAT activity proximal to the occluding balloon, which prevented further cycles. Unabsorbed 75SeHCAT was collected after total gut washout, which was administered distal to the occluding balloon. 75SeHCAT activity in the rectal effluent measured by gamma counter was compared with that of absorbed 75SeHCAT level measured by gamma camera and was used to calculate first-pass ileal clearance. This was very efficient (mean value, 96%) and showed very little variation in the six subjects studied (range, 95%-97%). A parallel time-activity course in hepatic bile for 14C and 75Se during a single enterohepatic cycle, together with a ratio of unity for 14C/75Se in samples obtained at different time intervals, suggests that 75SeHCAT is handled by the ileum like the natural bile acid cholic acid-taurine. Extrapolation of 75SeHCAT first-pass ileal clearance to that of the natural bile acid therefore seems justifiable. In a subsidiary experiment, ileal absorption efficiency per day for 75SeHCAT was also measured by scanning the gallbladder area on 5 successive days after the measurement of first-pass ileal clearance. In contrast with absorption efficiency per cycle, absorption efficiency per day varied widely (49%-86%)

  6. Individual renal clearance measurements in man using the early part of 131I-hippuran renogram. Comparison with 197HgCl2 fixation

    Quantitative measurement of individual renal function was assayed using analysis of the early part of 131I-Hippuran uptake curve obtained from single probes over kidneys and subclavicular area and recorded on magnetic tape. Blood background substraction was performed by calibration of the blood curve with a prior 131I-Albumin injection. Postulating the same detection efficiency for each kidney by a previous 125I-Hippuran injection, we calculated the clearance ratio as the ratio of the angular coefficient of the early part of the corrected renogram against the corresponding blood integral activity curve. Data processing was performed without any preimposed model. Individual clearances were calculated from the total clearance simultaneously measured using the simplified method without urine collection. In 7 control subjects, clearances expressed in per cent of total clearance, were 51.2+-1.3 and 48.3+-1.4 ml/min for right and left kidney respectively. In 4 uninephrectomized patients a precision of 5% in calculating individual clearance was estimated from data recorded at the level of the remaining kidney. In 8 patients with functional asymmetry, results were compared with 197Hg Cl2 fixation. A correlation coefficient of 0.95 was found. The method we propose seems valuable for clinical investigation, allowing repetitive measurements

  7. Evaluation of terrain geomorphometric characteristics for ground clearance charts production

    Mirko A. Borisov

    2011-01-01

    into the standard military procedure OCOKA (Observation and fields of fires; Cover and concealment; Obstacles and movement; Key terrain; Avenues of approach. A few parameters of relief significantly influencing the possibilities for cover and concealment (visibility, slope and aspect were included into the definition of the model of terrain spatial analysis The morphometric data included in partial assessment categories were determined on the basis of the digital model relief analysis and by using GIS tools and given morphometric relief exploration methods. Analysis of vegetation effects on ground clearance for military forces Vegetation, in addition to terrain slope, presents one of the main factors in cross-country analyses and ground clearance assessments. In classification and extraction of vegetation from satellite images, numerous algorithms of two basic classification types, supervised and unsupervised classification, are applied. Supervised classification requires the identification of cover types of interest by user. Samples of pixels are then selected, based on available ground real information to represent each cover type. These samples are called training areas. The selection of appropriate training areas is based on the analyst's familiarity with the geographical area and his knowledge of the actual surface cover types presented in the image. Thus, the analyst 'supervises' the categorization of a set of specific classes. Unsupervised classification basically reverses the supervised classification process. Spectral classes are grouped first, based solely on the numerical information in the data, and then they are matched by the analyst to information classes (if possible. Programs, called clustering algorithms, are used to determine the natural (statistical groupings or structures in the data. The analyst usually specifies how many groups or clusters are to be looked for in the data. In addition to specifying the desired number of classes, the analyst may

  8. Bromosulphophthalein clearance rates in sheep with pyrrolizidine liver damage.

    Lanigan, G W; Peterson, J E

    1979-05-01

    Sheep fed a ration containing 50% of dried Heliotropium europaeum showed a marked decline in bromosulphophthalein (BSP) fractional clearance rate during the first 3 months feeding. Thereafter, the response of individual animals varied widely on a time basis, although 3 groups could be identified. In the terminal stages, mean clearance rates were below 20% of initial values, with some sheep showing a decline in excess of 90%. Loss of liver functional capacity was generally much greater than indicated by the degree of damage revealed by histopathology. Thus, a suitably modified test could have considerable prognostic value in the field. In this investigation, all sheep with clearance rates below 0.15 died when exposed to a further period of H. europaeum feeding. PMID:475677

  9. Ineffective airway clearance in children with acute respiratory infection

    Lívia Zulmyra Cintra Andrade

    2014-03-01

    Full Text Available This cross-sectional study was performed with 151 children inpatients of a pediatric hospital in Northeastern Brazil, with the objective to analyze the accuracy of the defining characteristics of the diagnoses ineffective airway clearance in children with acute respiratory infection. A thorough respiratory evaluation was performed and the diagnostic inference was developed by specialists. The most frequent defining characteristics were adventitious breath sounds, ineffective cough, dyspnea, and changes in respiratory rate. Ineffective airway clearance was present in 37.7% of the sample. Agitation was the characteristic with the highest sensitivity. Dyspnea, adventitious breath sounds, orthopnea, changes in respiratory rate and agitation presented higher specificity for the diagnosis. In conclusion, the defining characteristics showed different performances to correctly classify children with infective airway clearance. Studies like this can contribute for a correct nursing diagnostic inference and for the implementation of more effective interventions, thus improving the quality of health care. Descriptors: Respiratory Tract Infections; Nursing Diagnosis; Child.

  10. Pharmacometabonomic Prediction of Busulfan Clearance in Hematopoetic Cell Transplant Recipients.

    Navarro, Sandi L; Randolph, Timothy W; Shireman, Laura M; Raftery, Daniel; McCune, Jeannine S

    2016-08-01

    Intravenous (IV) busulfan doses are often personalized to a concentration at steady state (Css) using the patient's clearance, which is estimated with therapeutic drug monitoring. We sought to identify biomarkers of IV busulfan clearance using a targeted pharmacometabonomics approach. A total of 200 metabolites were quantitated in 106 plasma samples, each obtained before IV busulfan administration in hematopoietic cell transplant (HCT) recipients. Both univariate linear regression with false discovery rate (FDR) and pathway enrichment analyses using the Global test were performed. In the univariate analysis, glycine, N-acetylglycine, 2-hydroxyisovaleric acid, creatine, serine, and tyrosine were statistically significantly associated with IV busulfan clearance at P 0.1. Glycine is a component of glutathione, which is conjugated with busulfan via glutathione transferase enzymes. These results demonstrate the potential utility of pharmacometabonomics to inform IV busulfan dosing. Future studies are required to validate these findings. PMID:27350098

  11. Progress with volunteer studies of nasal deposition and clearance

    Inhalation is the main route of intake of radioactive material for workers, and can be an important pathway for members of the public following accidental releases of radioactivity to the environment. Much of the inhaled radioactivity initially deposits in the nose, typically over 40% for particles of aerodynamic diameter (dae) greater than 2 μm. However, there is remarkably little information on the clearance from the human nose of particles deposited during inhalation and, until now, none on the clearance of the significant fraction of material that remains in the nasal passage for more than 12 hours. NRPB is conducting a volunteer study to determine the effects of particle size and breathing pattern on particle deposition in, and clearance from, the human nasal passage. This article summarises results obtained to date. (author)

  12. Effect of Internal Clearance on Load Distribution and Life of Radially Loaded Ball and Roller Bearings

    Oswald, Fred B.; Zaretsky, Erwin V.; Poplawski, Joseph V.

    2012-01-01

    The effect of internal clearance on radially loaded deepgroove ball and cylindrical roller bearing load distribution and fatigue life was determined for four clearance groups defined in the bearing standards. The analysis was extended to negative clearance (interference) conditions to produce a curve of life factor versus internal clearance. Rolling-element loads can be optimized and bearing life maximized for a small negative operating clearance. Life declines gradually with positive clearance and rapidly with increasing negative clearance. Relationships were found between bearing life and internal clearance as a function of ball or roller diameter, adjusted for load. Results are presented as life factors for radially loaded bearings independent of bearing size or applied load. In addition, a modified Stribeck Equation is presented that relates the maximum rolling-element load to internal bearing clearance.

  13. Nuclear security. DOE actions to improve the personnel clearance program

    The status of the Department of Energy's (DOE) implementation of recommendations in our two reports on DOE's personnel security clearance program was determined. The recommendations were aimed at improving the timeliness, accuracy, and efficiency of personnel security clearance decisions. Specifically, the objective was to determine and report on steps DOE is taking to implement these recommendations. In summary, it was found that DOE has either initiated action or is studying ways to address all the recommendations, but none of the recommendations have been completely implemented. The effectiveness of the DOE actions will depend, in part, on the adequacy of its internal control system for overseeing and evaluating program operations. DOE's personnel security clearance program is intended to provide reasonable assurance that personnel with access to classified information and materials are trustworthy. The Department requests that the Office of Personnel Management or the Federal Bureau of Investigation collect personal data on each person who requires such access to do his or her job. Based on these background investigations, DOE officials authorize individuals whose personal histories indicate that they are trustworthy to have access to classified information, secured facilities, and controlled materials as needed to perform their jobs. DOE has five types of these authorizations or personnel security clearances and must update information on personnel holding each type at 5-year intervals to confirm their continuing reliability. The five types are based on the types of security interests to which the person needs access, e.g., persons needing nuclear weapons-related data must have a Q clearance, and persons with a top secret clearance can have access to national security data classified as top secret

  14. Use of HμREL Human Coculture System for Prediction of Intrinsic Clearance and Metabolite Formation for Slowly Metabolized Compounds.

    Hultman, Ia; Vedin, Charlotta; Abrahamsson, Anna; Winiwarter, Susanne; Darnell, Malin

    2016-08-01

    Design of slowly metabolized compounds is an important goal in many drug discovery projects. Standard hepatocyte suspension intrinsic clearance (CLint) methods can only provide reliable CLint values above 2.5 μL/min/million cells. A method that permits extended incubation time with maintained performance and metabolic activity of the in vitro system is warranted to allow in vivo clearance predictions and metabolite identification of slowly metabolized drugs. The aim of this study was to evaluate the static HμREL coculture of human hepatocytes with stromal cells to be set up in-house as a standard method for in vivo clearance prediction and metabolite identification of slowly metabolized drugs. Fourteen low CLint compounds were incubated for 3 days, and seven intermediate to high CLint compounds and a cocktail of cytochrome P450 (P450) marker substrates were incubated for 3 h. In vivo clearance was predicted for 20 compounds applying the regression line approach, and HμREL coculture predicted the human intrinsic clearance for 45% of the drugs within 2-fold and 70% of the drugs within 3-fold of the clinical values. CLint values as low as 0.3 μL/min/million hepatocytes were robustly produced, giving 8-fold improved sensitivity of robust low CLint determination, over the cutoff in hepatocyte suspension CLint methods. The CLint values of intermediate to high CLint compounds were at similar levels both in HμREL coculture and in freshly thawed hepatocytes. In the HμREL coculture formation rates for five P450-isoform marker reactions, paracetamol (CYP1A2), 1-OH-bupropion (CYP2B6), 4-OH-diclofenac (CYP2C9), and 1-OH-midazolam (3A4) were within the range of literature values for freshly thawed hepatocytes, whereas 1-OH-bufuralol (CYP2D6) formation rate was lower. Further, both phase I and phase II metabolites were detected and an increased number of metabolites were observed in the HμREL coculture compared to hepatocyte suspension. In conclusion, HμREL coculture can

  15. Effects of bearing outer clearance on the dynamic behaviours of the full floating ring bearing supported turbocharger rotor

    Tian, L.; Wang, W. J.; Peng, Z. J.

    2012-08-01

    As a high speed rotating device, the modern turbocharger rotor is commonly supported by floating ring bearings (FRBs). The high nonlinearity there can always lead to quite complex and interesting phenomena rarely observed in other rotating applications. Using the run-up and run-down simulation method, this paper originally and systematically discusses the effect of bearing outer clearance on the rotordynamic characteristics of a realistic turbocharger rotor over the speed range up to 3000 Hz. The rotor is discretized by the Finite Element Method and supported by analytically calculated bearing forces. The linear analysis is proved to be effective in predicting the first two nonlinear jumps but inadequate to study the rotordynamic characteristics at higher rotor speeds. The nonlinearly simulated results show the appearances of distinct and interesting phenomena within the considered range of FRB outer clearance, which can be further divided into four groups. Within the same group, the simulation results are qualitatively similar to each other but quite dissimilar from the results from different groups. Moreover, the unwelcome Critical Limit Cycle Oscillation can be avoided by increasing the outer clearance size. Additionally, in some cases, the run-down simulations reveal distinct frequency maps as compared to the corresponding run-ups. Furthermore, it is seen that ring speed ratios can be considerably affected by the nonlinear jumps. Therefore, FRB outer clearance should be thoroughly examined to achieve the best rotordynamic performance.

  16. Determination of hepatic fractional clearance of radioactive gold colloids for a measure of effective hepatic blood flow

    For a measure of effective blood flow, a hepatic fractional clearance of 198Au-colloids was determined, which was obtained from the disappearance rate multiplied by the fraction of injected dose taken up by the liver. The hepatic uptake was determined with a gamma camera. The counts over the liver was corrected for body weight and height. The method was considered sufficiently simple for routine use. 198Au-colloids were obtained from Dainabot Lab. and CIS. The former gave 64% higher values of disappearance rate than the latter, without any change in the organ distribution. A quality control tests were applied over a six-year period to the disappearance rates. Reproducibility within 95 to confidence limits was found for both groups. In 28 normal control subjects, hepatic fractional clearance of the colloids from Dainabot Lab. was 18.5 +- 3.4%/min. In patients with progressed hepatic disease, both hepatic fractional clearance and final hepatic uptake were decreased, showing that the determination of hepatic uptake is necessary in measuring effective hepatic blood flow by the colloidal clearance method. The influence of splenic uptake is discussed in relation to hepatic blood flow measurement. (author)

  17. A novel technique of contrast-enhanced optical coherence tomography imaging in evaluation of clearance of lipids in human tears.

    Pietro Emanuele Napoli

    Full Text Available PURPOSE: The aim of this work was to gather preliminary data in different conditions of healthy eyes, aqueous tear deficient dry eyes, obstructive meibomian gland disease (MGD and non-obvious obstructive MGD (NOMGD individuals, using a new, contrast-enhanced optical coherence tomography (OCT imaging method to evaluate the clearance of lipids in human tears. METHODS: Eighty-two adult patients presenting with complaints of ocular irritation were studied for abnormalities of the ocular surface and classified as healthy (n = 21, aqueous tear deficient dry eyes (n = 20, obstructive MGD (n = 15 and NOMGD (n = 26 individuals. A lipid-based tracer, containing an oil-in-water emulsion, was used to obtain an enhanced OCT imaging of the lower tear meniscus. After instillation, a dramatic initial increase of reflectivity of the lower tear meniscus was detected by OCT, followed by a decay back to baseline values over time. Based on this finding, the clearance of lipids was measured in real-time by Fourier-domain anterior segment OCT. RESULTS: The differences in the clearance of lipids among the four groups as well as the correlations between symptom questionnaire score, standardized visual scale test, fluorescein break-up time, ocular surface fluorescein staining score, Schirmer I test scores were found to be statistically significant. The individual areas under the curve of the clearance of lipids calculated by the receiver operating characteristic curve technique ranged from 0.66 to 0.98, suggesting reliable sensitivity and specificity of lipid-enhanced OCT imaging. CONCLUSIONS: This new technique of contrast-enhanced OCT imaging of the tear film following lipid-based tracer instillation provides a measure of the clearance of lipids. The quantitative values found are in agreement with other methods of evaluation of the lacrimal system. An improvement of the clinician's ability in the diagnosis and understanding of abnormalities of the ocular surface may be

  18. 75 FR 52798 - State-07, Cryptographic Clearance Records

    2010-08-27

    ...: Unclassified. SYSTEM LOCATION: Department of State, 301 4th St., SW., Room 750 Washington, DC 20547. CATEGORIES... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE State-07, Cryptographic Clearance Records Summary: Notice is hereby given that the Department of State proposes to...

  19. Effect of lindane on the clearance rate of Daphnia magna

    Hartgers, E.M.; Heugens, E.W.; Deneer, J.W.

    1999-01-01

    The impact of the insecticide lindane (%-hexachlorocyclohexane) on the clearance rate (CR) of Daphnia magna was investigated using artificial beads. CR (24-h EC50: 65 7g Lm1) was found to be a more sensitive endpoint than acute lethality for D. magna (48-h LC50: 516 7g Lm1). The onset of the effect

  20. Modifications of lung clearance mechanisms by acute influenza A infection

    Four volunteers with naturally acquired, culture-proved influenza A infection inhaled a radiolabeled aerosol to permit investigation of lung mucociliary clearance mechanisms during and after symptomatic illness. Mucus transport in the trachea was undetectable when monitored with an external multidetector probe within 48 hours of the onset of the illness, but was found at a normal velocity by 1 week in three of the four subjects. In two volunteers who coughed 23 to 48 times during the 4.5-hour observation period, whole lung clearance was as fast within the first 48 hours of illness as during health 3 months later in spite of the absence of measurable tracheal mucus transport. Conversely, in spite of the return 1 week later of mucus transport at velocities expected in the trachea, whole lung clearance for the 4.5-hour period was slowed in two volunteers who coughed less than once an hour. The data offer evidence that cough is important in maintaining lung clearance for at least several days after symptomatic influenza A infection when other mechanisms that depend on ciliary function are severely deficient

  1. 33 CFR 157.455 - Minimum under-keel clearance.

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Minimum under-keel clearance. 157.455 Section 157.455 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION RULES FOR THE PROTECTION OF THE MARINE ENVIRONMENT RELATING TO TANK VESSELS CARRYING OIL IN BULK Interim Measures for Certain...

  2. 14 CFR 93.311 - Minimum terrain clearance.

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Minimum terrain clearance. 93.311 Section 93.311 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SPECIAL AIR TRAFFIC RULES Special Flight Rules in the Vicinity of Grand Canyon National Park, AZ §...

  3. Decision Assessment of Clearance Level on Radioactive Waste Management

    Radioactive waste on the safe level activity containing very small radioactive material gives small radiology influence to the human, it is not necessary to control by regulatory body. The radioactive waste on the safe level activity is safe to release as the common waste. For exemption of the control, it is required the safe activity level limits in which the value of clearance level is fulfilled by regulatory body, however until now it is not decided yet. The exemption decision is obtained if its activity is lower than or same with clearance level based on the annual effective dose receiving by public on the value is lower than or same with 0,01 mSv. The exposure pathways of radioactive waste to the human have important role for determination of clearance level. The decision assessment of clearance level on the radioactive waste management has been done by analysis of radioactive exposure pathways to the human for activities of the disposal and the recycle of solid wastes, also the release of liquid and gas effluent. For solid waste disposal, the exposure pathway was evaluated since the transportation of packed waste from the treatment facility to the disposal facility and during its operation. Exposure pathways for solid waste recycle consist of the pathways for handling and transportation of cleared material to the recycling facility, the fabrication and the utilization of its product. Exposure pathways for liquid and gas releases occur since its releases to the environment up to the human (public) by specific traffic lane. (author)

  4. 33 CFR 151.1508 - Revocation of clearance.

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Revocation of clearance. 151.1508 Section 151.1508 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID SUBSTANCES, GARBAGE, MUNICIPAL OR COMMERCIAL WASTE, AND BALLAST WATER Ballast Water...

  5. In Vivo Renal Clearance, Biodistribution, Toxicity of Gold nanoclusters

    Zhang, Xiao-Dong; Shen, Xiu; Liu, Pei-Xun; Fan, Fei-Yue; Fan, Sai-Jun; 10.1016/j.biomaterials.2012.03.020

    2012-01-01

    Gold nanoparticles have shown great prospective in cancer diagnosis and therapy, but they can not be metabolized and prefer to accumulate in liver and spleen due to their large size. The gold nanoclusters with small size can penetrate kidney tissue and have promise to decrease in vivo toxicity by renal clearance. In this work, we explore the in vivo renal clearance, biodistribution, and toxicity responses of the BSA- and GSH-protected gold nanoclusters for 24 hours and 28 days. The BSA-protected gold nanoclusters have low-efficient renal clearance and only 1% of gold can be cleared, but the GSH-protected gold nanoclusters have high-efficient renal clearance and 36 % of gold can be cleared after 24 hours. The biodistribution further reveals that 94% of gold can be metabolized for the GSH-protected nanoclusters, but only less than 5% of gold can be metabolized for the BSA-protected nanoclusters after 28 days. Both of the GSH- and BSA-protected gold nanoclusters cause acute infection, inflammation, and kidney fu...

  6. Highly fluorescent resorcinarene cavitand nanocapsules with efficient renal clearance

    Mahadevan, Kalpana; Patthipati, Venkata Suresh; Han, Sangbum; Swanson, R. James; Whelan, Eoin C.; Osgood, Christopher; Balasubramanian, Ramjee

    2016-08-01

    Nanomaterial based imaging approaches hold substantial promise in addressing current diagnostic and therapeutic challenges. One of the key requirements for the successful clinical translation of nanomaterials is their complete clearance from the body within a reasonable time period preferably via the renal filtration route. This article describes the synthesis of highly fluorescent, water soluble, resorcinarene cavitand nanocapsules and demonstrates their effective renal clearance in mice. The synthesis and functionalization of nanocapsules was accomplished in a one-pot operation via thiol-ene reactions without involving self-assembly, sacrificial templates or emulsions. Water soluble resorcinarene cavitand nanocapsules obtained by this approach were covalently functionalized with Alexa Fluor 750. Highly fluorescent nanocapsules with hydrodynamic diameters of 122 nm and 68 nm and extinction coefficients of 1.3 × 109 M‑1 cm‑1 and 1.5 × 108 M‑1 cm‑1 respectively were prepared by varying the reaction conditions. The in vivo biodistribution and clearance of these nanocapsules in mice followed by whole-body fluorescence imaging showed that they were both cleared renally within a few hours. Given the inherent encapsulation capabilities of nanocapsules, the renal clearance demonstrated in this work opens up new opportunities for their theranostic applications especially for targeting and treating the urinary tract.

  7. Influence of clearance model on numerical simulation of centrifugal pump

    Wang, Z.; Gao, B.; Yang, L.; Du, W. Q.

    2016-05-01

    Computing models are always simplified to save the computing resources and time. Particularly, the clearance that between impeller and pump casing is always ignored. But the completer model is, the more precise result of numerical simulation is in theory. This paper study the influence of clearance model on numerical simulation of centrifugal pump. We present such influence via comparing performance, flow characteristic and pressure pulsation of two cases that the one of two cases is the model pump with clearance and the other is not. And the results show that the head decreases and power increases so that efficiency decreases after computing with front and back cavities. Then no-leakage model would improve absolute velocity magnitude in order to reach the rated flow rate. Finally, more disturbance induced by front cavity flow and wear-ring flow would change the pressure pulsation of impeller and volute. The performance of clearance flow is important for the whole pump in performance, flow characteristic, pressure pulsation and other respects.

  8. Early clearance of Mycobacterium tuberculosis: a new frontier in prevention

    Verrall, A.J.; Netea, M.G.; Alisjahbana, B.; Hill, P.C.; Crevel, R. van

    2014-01-01

    Early clearance (EC) is the successful eradication of inhaled Mycobacterium tuberculosis before an adaptive immune response develops. Evidence for EC comes from case contact studies that consistently show that a proportion of heavily exposed individuals do not develop M. tuberculosis infection. Furt

  9. Cell death, clearance and immunity in the skeletal muscle.

    Sciorati, C; Rigamonti, E; Manfredi, A A; Rovere-Querini, P

    2016-06-01

    The skeletal muscle is an immunologically unique tissue. Leukocytes, virtually absent in physiological conditions, are quickly recruited into the tissue upon injury and persist during regeneration. Apoptosis, necrosis and autophagy coexist in the injured/regenerating muscles, including those of patients with neuromuscular disorders, such as inflammatory myopathies, dystrophies, metabolic and mitochondrial myopathies and drug-induced myopathies. Macrophages are able to alter their function in response to microenvironment conditions and as a consequence coordinate changes within the tissue from the early injury throughout regeneration and eventual healing, and regulate the activation and the function of stem cells. Early after injury, classically activated macrophages ('M1') dominate the picture. Alternatively activated M2 macrophages predominate during resolution phases and regulate the termination of the inflammatory responses. The dynamic M1/M2 transition is increasingly felt to be the key to the homeostasis of the muscle. Recognition and clearance of debris originating from damaged myofibers and from dying stem/progenitor cells, stromal cells and leukocytes are fundamental actions of macrophages. Clearance of apoptotic cells and M1/M2 transition are causally connected and represent limiting steps for muscle healing. The accumulation of apoptotic cells, which reflects their defective clearance, has been demonstrated in various tissues to prompt autoimmunity against intracellular autoantigens. In the muscle, in the presence of type I interferon, apoptotic myoblasts indeed cause the production of autoantibodies, lymphocyte infiltration and continuous cycles of muscle injury and regeneration, mimicking human inflammatory myopathies. The clearance of apoptotic cells thus modulates the homeostatic response of the skeletal muscle to injury. Conversely, defects in the process may have deleterious local effects, guiding maladaptive tissue remodeling with collagen and fat

  10. Clearance of technetium-99m-DTPA and HRCT findings in the evaluation of patients with Idiopathic Pulmonary Fibrosis

    Karkavitsas Nikolaos

    2006-02-01

    Full Text Available Abstract Background Clearance of inhaled technetium-labeled diethylenetriamine pentaacetate (99mTc-DTPA is a marker of epithelial damage and an index of lung epithelial permeability. The aim of this study was to investigate the role of 99mTc-DTPA scan in patients with Idiopathic Pulmonary Fibrosis (IPF. Our hypothesis is that the rate of pulmonary 99mTc-DTPA clearance could be associated with extent of High Resolution Computed Tomography (HRCT abnormalities, cell differential of bronchoalveolar lavage fluid (BALF and pulmonary function tests (PFTs in patients with IPF. Methods We studied prospectively 18 patients (14 male, 4 female of median age 67yr (range 55–81 with histologically proven IPF. HRCT scoring included the mean values of extent of disease. Mean values of these percentages represented the Total Interstitial Disease Score (TID. DTPA clearance was analyzed according to a dynamic study using a Venticis II radioaerosol delivery system. Results The mean (SD TID score was 36 ± 12%, 3 patients had mild, 11 moderate and 4 severe TID. Abnormal DTPA clearance half-time (t1/2 Conclusion Our data suggest that 99mTc-DTPA lung scan is not well associated with HRCT abnormalities, PFTs, and BALF cellularity in patients with IPF. Further studies in large scale of patients are needed to define the role of this technique in pulmonary fibrosis.

  11. Purpose and Working Contents of Clearance%清场的目的和工作内容

    马建玲; 聂森

    2012-01-01

    In order to reduce errors in the production process to the minimum level and prevent to cause cross contamination and confusion, the production process must have a program of clearance. Therefore, the content of clearance should aim at every aspect of production activity. The purpose of clearance was introduced, and the working contents of clearance were summarized, mainly containing five aspects of human, machine, material, method and link.%为了将生产过程中的差错降至最低程度,防止引起交叉污染和混淆,生产过程中必须要有清场的程序。清场是对生产活动产生的影响的清除工作,因此,其内容应针对生产活动的各个方面。概括了清场的目的,并总结了清场所需完成的工作内容,主要包括“人、机、料、法、环”五个方面。

  12. A comparison of analytic procedures for measurement of fractional dextran clearances

    Hemmelder, MH; de Jong, PE; de Zeeuw, D

    1998-01-01

    Fractional dextran clearances have been extensively used to study glomerular size selectivity. We report on an analysis of different laboratory procedures involved in measuring fractional dextran clearances. The deproteinization of plasma samples by 20% trichloroacetic acid (TCA) revealed a protein

  13. Tissue Clearance of 131I and Total Peripheral Resistance in Myocardial Infarction and Hypertension, and During Angiotensin Infusion

    Tissue clearance of 131I from the thigh, cardiac output and peripheral resistance was determined in 25 patients: 13 normotensive with recent myocardial infarction but not in congestive heart failure, 7 with hypertension and 5 normotensive control subjects. The effect of the synthesized pressor agent Angiotensin II on the same three measurements was also studied. The present investigation continues a previous one of ours, where a tracer dose of 131I was injected into the thigh of patients with recent myocardial infarction without signs of heart failure, and its clearance was found to be longer than that of normal subjects. This was thought to be due to increased peripheral resistance or to reduced perfusion of the capillary bed secondary to lowered cardiac output, With the 25 subjects, injection into the thigh of tracer amounts of radioactive iodine was done by Hypospray, a method with distinct advantages over needle injection. After measuring tissue clearance of the tracer, cardiac output was determined by a method which records the transit of the injected radioactive bolus through the heart. The Angiotensin was administered by intravenous infusion to four of the normotensive and one of the hypertensive patients. Calculations of cardiac output, total peripheral resistance, mean blood pressure and blood volume were made by means of standard formulae. Results of the study confirmed expectations. Those patients with myocardial infarction who had delayed tissue clearance of 131I also had reduced cardiac output. The patients with hypertension had normal tissue clearance of 131I and normal cardiac output in the presence of increased peripheral resistance. Equivalent hypertension and increased peripheral resistance induced in normotensive subjects by Angiotensin resulted in lowered cardiac output and delayed tissue clearance of 131I. An increased sensitivity to Angiotensin was noted in hypertensive patients. The tissue clearance of 131I, as we have carried it out

  14. Consumer Response to Seasonal Clearance Sales: Experimental Analysis of Consumer Personality Traits in Self Service Stores

    Rajagopal, MR

    2006-01-01

    Consumer responses to clearance sales, both in terms of consumer satisfaction with the decision process and in terms of subsequent store choice behavior, are explored in the paper through four controlled experiments conducted involving clearance sales in a consumer choice and decision satisfaction context. The results suggest that consumer response to clearance sales is driven to a large extent by two factors: the effect of a clearance sale on the available options of goods and the degree of ...

  15. /sup 131/I-Orthoiodohippurate clearance in the detection of cisplatin nephrotoxicity

    Hengst, W.; Wieler, H.; Rabs, U.; Buerger, R.A.

    1985-06-01

    In this study, 26 patients were treated with 20 mg cisplatin (CP)/m/sup 2/ body surface daily for 5 days as part of a combination therapy for testicular cancer. Simultaneously a vigorous hyperhydration (3000 ml daily) was applied to reduce the nephrotoxic effect induced by the drug. sup(/sup 131/I)-orthoiodophippurate clearance values obtained by the modified method of Oberhausen did not show any significant evidence of tubular dysfunction after therapy. These results may have been due to the vigorous hydration as well as to the youth of the patients.

  16. 131I-orthoiodohippurate clearance in the detection of cisplatin nephrotoxicity

    In this study, 26 patients were treated with 20 mg cisplatin (CP)/m2 body surface daily for 5 days as part of a combination therapy for testicular cancer. Simultaneously a vigorous hyperhydration (3000 ml daily) was applied to reduce the nephrotoxic effect induced by the drug. sup(131I)-orthoiodophippurate clearance values obtained by the modified method of Oberhausen did not show any significant evidence of tubular dysfunction after therapy. These results may have been due to the vigorous hydration as well as to the youth of the patients. (orig.)

  17. Crosstalk between the proteasome system and autophagy in the clearance of α-synuclein

    Yang, Fang; Yang, Ya-Ping; Mao, Cheng-Jie; Liu, Ling; Zheng, Hui-fen; Hu, Li-Fang; Liu, Chun-Feng

    2013-01-01

    Aim: A growing body of evidence suggests that α-synuclein accumulation may play an important role in the pathogenesis of Parkinson's disease. The aim of this study was to investigate the roles of the proteasome and autophagy pathways in the clearance of wild-type and mutant α-synuclein in PC12 cells. Methods: PC12 cells overexpressing either wild-type or A30P mutant α-synuclein were treated with the proteasome inhibitor epoxomicin, the macroautophagy inhibitor 3-MA and the macroautophagy acti...

  18. Non-linear dynamic of rotor-stator system with non-linear bearing clearance

    Sinou, Jean-Jacques

    2008-01-01

    The study deals with a rotor-stator contact inducing vibration in rotating machinery. A numerical rotor-stator system, including a non-linear bearing with Hertz contact and clearance is considered. To determine the non-linear responses of this system, non-linear dynamic equations can be integrated numerically. However, this procedure is both time consuming and costly to perform. The aim of this Note is to apply the Alternate Frequency/Time Method and the 'path following continuation' in order to obtain the non-linear responses to this problem. Then the orbits of rotor and stator responses at various speeds are investigated.

  19. Antibody response following Hepatitis B vaccination in peritoneal dialysis patients: does normalized urea clearance matter?

    Erkan Dervisoglu; Melih Simsek; Ahmet Yilmaz

    2011-01-01

    OBJECTIVES: Data on the factors that contribute to the antibody response to hepatitis B virus vaccination in peritoneal dialysis patients are scarce. The current study was conducted on a group of peritoneal dialysis patients to learn how the response to hepatitis B virus vaccination varies according to the patient's clearance of urea normalized to total body water (Kt/V). METHODS: A convenience sample of 33 peritoneal dialysis patients (13 women and 20 men, with a mean age of 49¡12 years) was...

  20. Optimising technetium 99m diethylenetriaminepenta-acetate lung clearance in patients with the acquired immunodeficiency syndrome

    Pneumocystis carinii pneumonia (PCP) has become a major cause of morbidity and mortality due to infectious diseases, largely as a result of the acquired immunodeficiency syndrome (AIDS) epidemic. Since the mortality from recurrent infection is between 40% and 60%, early diagnosis and therapy are the keys to survival. The role of technetium 99m diethylenetriaminepentacetate (DTPA) aerosol pulmonary clearance was studied in 81 patients with AIDS. The mathematical technique of curve stripping was found to be the optimal method of analysis and to provide an overall sensitivity of 94% for the detection of interstitial pneumonitis. The procedure was superior to standard pathology parameters and radiography and more convenient than gallium 67 scintigraphy. (orig.)

  1. Experimental non-steroidal anti-inflammatory drug-induced enteropathy in the rat: similarities to inflammatory bowel disease and effect of thromboxane synthetase inhibitors.

    Banerjee, A K; Peters, T. J.

    1990-01-01

    We have validated an established animal model of acute inflammatory bowel disease in indomethacin-treated rats. Studies in both in vitro and in vivo 51chromium-labelled ethylenediamine tetra-acetate (51Cr-EDTA) permeability and tissue myeloperoxidase activity, a marker of inflammatory cell invasion, showed increased permeability and enzyme levels, respectively, in treated animals compared to controls (in vitro 51Cr-EDTA permeability: (mean (SE] control 0.10 (0.02) microliter/mg per tissue, ex...

  2. Music Rights Clearance Business Analysis and Delivery

    Pedrinaci, Carlos; Baida, Ziv; Akkermans, Hans; Bernaras, Amaia; Gordijn, Jaap; Smithers, Tim

    2005-01-01

    Semantic Web Services can be seen as remote Problem Solving Methods offered via the Web through platform and language independent interfaces. They can be seamlessly integrated to achieve more complex functionality by composing pre-existing software components. Despite technical advantages surrounding Semantic Web Services technologies, their perspective overlooks the commercial aspects of services in the real – non-IT – world, and is therefore incomplete and limiting. Real-world services – bu...

  3. 48 CFR 245.7101-4 - DD Form 1640, Request for Plant Clearance.

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false DD Form 1640, Request for Plant Clearance. 245.7101-4 Section 245.7101-4 Federal Acquisition Regulations System DEFENSE... Forms 245.7101-4 DD Form 1640, Request for Plant Clearance. Use to request plant clearance assistance...

  4. EMS Adherence to a Pre-hospital Cervical Spine Clearance Protocol

    Johnson, David

    2001-10-01

    Full Text Available Purpose: To determine the degree of adherence to a cervical spine (c-spine clearance protocol by pre-hospital Emergency Medical Services (EMS personnel by both self-assessment and receiving hospital assessment, to describe deviations from the protocol, and to determine if the rate of compliance by paramedic self-assessment differed from receiving hospital assessment. Methods: A retrospective sample of pre-hospital (consecutive series and receiving hospital (convenience sample assessments of the compliance with and appropriateness of c-spine immobilization. The c-spine clearance protocol was implemented for Orange County EMS just prior to the April-November 1999 data collection period. Results: We collected 396 pre-hospital and 162 receiving hospital data forms. From the pre-hospital data sheet. the percentage deviation from the protocol was 4.096 (16/396. Only one out of 16 cases that did not comply with the protocol was due to over immobilization (0.2%. The remaining 15 cases were under immobilized, according to protocol. Nine of the under immobilized cases (66% that should have been placed in c-spine precautions met physical assessment criteria in the protocol, while the other five cases met mechanism of injury criteria. The rate of deviations from protocol did not differ over time. The receiving hospital identified 8.0% (13/162; 6/16 over immobilized, 7/16 under immobilized of patients with deviations from the protocol; none was determined to have actual c-spine injury. Conclusion: The implementation of a pre-hospital c-spine clearance protocol in Orange County was associated with a moderate overall adherence rate (96% from the pre-hospital perspective, and 92% from the hospital perspective, p=.08 for the two evaluation methods. Most patients who deviated from protocol were under immobilized, but no c-spine injuries were missed. The rate of over immobilization was better than previously reported, implying a saving of resources.

  5. Effect of needle puncture and electro-acupuncture on mucociliary clearance in anesthetized quails

    Wang Tianshan

    2006-02-01

    Full Text Available Abstract Background Acupuncture therapy for obstructive respiratory diseases has been effectively used in clinical practice and the acupuncture points or acupoints of Zhongfu and Tiantu are commonly-used acupoints to treat patients with the diseases. Since the impaired mucociliary clearance is among the most important features of airway inflammation in most obstructive respiratory diseases, the effect of needle puncture and electro-acupuncture at the specific acupoints on tracheal mucociliary clearance was investigated in anesthetized quails. Methods Mucociliary transport velocity on tracheal mucosa was measured through observing the optimal pathway, and fucose and protein contents in tracheal lavages were determined with biochemical methods. In the therapeutic group, needle puncture or electro-acupuncture stimulation to the acupoints was applied without or with constant current output in 2 mA and at frequency of 100 Hz for 60 minutes. In the sham group, electro-acupuncture stimulation to Liangmen was applied. Results Our present experiments demonstrated that the electro-acupuncture stimulation to Zhongfu and Tiantu significantly increased tracheal mucociliary transport velocity and decreased the content of protein in the tracheal lavage, compared with the control group. Moreover, either needle puncture or electro-acupuncture stimulation to Zhongfu and Tiantu significantly reverted the human neutrophil elastase-induced decrease in tracheal mucociliary transport velocity and human neutrophil elastase -induced increase in the contents of fucose and protein in the tracheal lavage, compared with the control group. Conclusion These results suggest that either needle puncture or electro-acupuncture stimulation to the effective acupoints significantly improves both airway mucociliary clearance and the airway surface liquid and that the improvements maybe ascribed to both the special function of the points and the substantial stimulation of electricity.

  6. The relationship between the renal clearance of creatinine and the apparent renal clearance of beta-2-microglobulin in patients with normal and impaired kidney function.

    Vree, T B; Guelen, P J; Jongman-Nix, B; Walenkamp, G H

    1981-07-18

    The renal clearances of creatinine and beta 2-microglobulin of patients with either normal or impaired kidney function were measured. The renal clearance of beta 2-microglobulin depends on the urinary pH and must be considered as an apparent renal clearance because after tubular reabsorption the compound is metabolized in the kidney. Impaired kidney function reduces the percentage of tubular reabsorption of beta 2-microglobulin. PMID:6166414

  7. Nanoparticle clearance from the airways : development and testing of a new in vitro model to investigate mucociliary clearance of aerosol particles

    Henning, Andreas Michael

    2008-01-01

    The current challenge in pulmonary drug delivery is to overcome and to control drug clearance from the lung. Here, the interaction with the mucociliary lung clearance plays a key role for any drug formulation technology. By today many open questions on mucociliary clearance (MC) have to be answered but suffer from limited experimental options. Considering these facts, the central part of this work was to develop a new in vitro test model to investigate the complex mechanism of MC more detaile...

  8. Escherichia coli clearance after splenic autotransplants

    Background: Splenic autotransplantation seems to be the only alternative for preservation of splenic tissue, after total splenectomy. The present study was carried out to analyze Escherichia coli depuration by mononuclear phagocyte system organs after total splenectomy and splenic autotransplantation. Methods: We utilized an experimental model including young and adult Wistar rats, of both sexes, submitted to total splenectomy and splenic autotransplantation. The evaluation method was intravenous inoculation of a suspension of Escherichia coli labeled with technetium-99m. We analyzed bacteria uptake by mononuclear phagocyte system organs and bacteria remnant in the bloodstream. Results: There was no difference between young and adult animals in bacteria uptake by mononuclear phagocyte system organs. In the comparison of groups, it was found out that the mean percent uptake by spleen and liver of animals in the control group was higher than that observed for animals with splenic implants. However, bacteria uptake in the lung was higher in the splenic implant group than in the control group. Although spleen bacteria uptake in the control group animals has been higher than that of animals in the splenic implant group, the remnant bacteria in the bloodstream was similar. Animals submitted to isolated total splenectomy showed higher bacteria remnant in the bloodstream than animals of the control group or the group submitted to total splenectomy combined with splenic autotransplantation. Conclusion: Our results indicate that autogenous splenic implant is efficacious in bacteria depuration in rats, by means of their macrophages phagocytosis. In addition, it does not modify bacteria removal function of liver and lung

  9. Clearance of nuclear waste and decommissioned nuclear facilities

    2008-07-01

    The guide is applied to waste, including recyclable materials, arising from the operation and decommissioning of a nuclear facility, as well as to non-dismantled buildings and surrounding sites being subject to regulatory control. The guide gives the radiation protection principles to be followed in the planning and implementation of clearances. The guide also covers the clearance procedures and the activity monitoring and record-keeping of materials to be cleared. The guide does not address radioactive waste or contaminated sites arising as a consequence of the utilization of natural resources. The guidance for such activities is given in Section 13 of the Finnish Radiation Act, Section 6 of the Radiation Decree and in STUK's (Finnish Radiation and Nuclear Safety Authority) guides ST 6.2, ST 12.1 and ST 12.2

  10. Effect of surface-active substance on nasal mucociliary clearance time

    Outzen, K E; Svane-Knudsen, V

    1993-01-01

    Mucociliary clearance measured by saccharin clearance time is depending on ciliary function and on the physiological characteristics of mucus. The aim of this study was to determine whether the application of surface-active substances changed the mucociliary transport time. Twenty healthy persons...... were manually sprayed with surface-active substance in one of their nose cavities. The saccharin clearance time was measured before spraying and statistically compared with saccharin clearance time after spraying. Saccharin clearance time was significantly shortened immediately after spraying with...

  11. RENAL CLEARANCE AND URINARY EXCRETION OF CIPROFLOXACIN IN GOATS

    Z. IQBAL, I. JAVED, B. ASLAM, F. MUHAMMAD AND I. U. JAN

    2007-01-01

    The renal clearance and urinary excretion of ciprofloxacin were investigated in eight healthy female goats. In each animal, ciprofloxacin was administered intramuscularly at the rate of 5 mg/kg body weight. Following drug administration, blood and urine samples were collected at different time intervals and analyzed for ciprofloxacin and creatinine. High performance liquid chromatography (HPLC) was used to determine the drug concentration in the plasma and urine. The value of diuresis after s...

  12. Surface code—biophysical signals for apoptotic cell clearance

    Apoptotic cell death and the clearance of dying cells play an important and physiological role in embryonic development and normal tissue turnover. In contrast to necrosis, apoptosis proceeds in an anti-inflammatory manner. It is orchestrated by the timed release and/or exposure of so-called ‘find-me’, ‘eat me’ and ‘tolerate me’ signals. Mononuclear phagocytes are attracted by various ‘find-me’ signals, including proteins, nucleotides, and phospholipids released by the dying cell, whereas the involvement of granulocytes is prevented via ‘stay away’ signals. The exposure of anionic phospholipids like phosphatidylserine (PS) by apoptotic cells on the outer leaflet of the plasma membrane is one of the main ‘eat me’ signals. PS is recognized by a number of innate receptors as well as by soluble bridging molecules on the surface of phagocytes. Importantly, phagocytes are able to discriminate between viable and apoptotic cells both exposing PS. Due to cytoskeleton remodeling PS has a higher lateral mobility on the surfaces of apoptotic cells thereby promoting receptor clustering on the phagocyte. PS not only plays an important role in the engulfment process, but also acts as ‘tolerate me’ signal inducing the release of anti-inflammatory cytokines by phagocytes. An efficient and fast clearance of apoptotic cells is required to prevent secondary necrosis and leakage of intracellular danger signals into the surrounding tissue. Failure or prolongation of the clearance process leads to the release of intracellular antigens into the periphery provoking inflammation and development of systemic inflammatory autoimmune disease like systemic lupus erythematosus. Here we review the current findings concerning apoptosis-inducing pathways, important players of apoptotic cell recognition and clearance as well as the role of membrane remodeling in the engulfment of apoptotic cells by phagocytes. (paper)

  13. Mathematical modeling and analysis of insulin clearance in vivo

    Koschorreck, Markus; Gilles, Ernst Dieter

    2008-01-01

    Background Analyzing the dynamics of insulin concentration in the blood is necessary for a comprehensive understanding of the effects of insulin in vivo. Insulin removal from the blood has been addressed in many studies. The results are highly variable with respect to insulin clearance and the relative contributions of hepatic and renal insulin degradation. Results We present a dynamic mathematical model of insulin concentration in the blood and of insulin receptor activation in hepatocytes. ...

  14. Mathematical modeling and analysis of insulin clearance in vivo

    Koschorreck, M.; Gilles, E. D.

    2008-01-01

    Background: Analyzing the dynamics of insulin concentration in the blood is necessary for a comprehensive understanding of the effects of insulin in vivo. Insulin removal from the blood has been addressed in many studies. The results are highly variable with respect to insulin clearance and the relative contributions of hepatic and renal insulin degradation. Results: We present a dynamic mathematical model of insulin concentration in the blood and of insulin receptor acti...

  15. Mathematical modeling and analysis of insulin clearance in vivo

    Koschorreck, M.; Gilles, E.

    2008-01-01

    Background: Analyzing the dynamics of insulin concentration in the blood is necessary for a comprehensive understanding of the effects of insulin in vivo. Insulin removal from the blood has been addressed in many studies. The results are highly variable with respect to insulin clearance and the relative contributions of hepatic and renal insulin degradation. Results: We present a dynamic mathematical model of insulin concentration in the blood and of insulin receptor activation in hepatocytes...

  16. Respiratory Protection Program medical clearance for respirator use

    1993-01-01

    Background on occupational exposure to various inhalents is discussed including on-site hazard control measures, procedures, physiological effects, and interpretation of results for the medical clearance of employee for use of personal respiratory protection devices. The purpose of the Respiratory Protection Program at LeRC is outlined, and the specifics of the Medical Surveillance Program for Respiratory Protection at LeRC are discussed.

  17. Lactadherin and clearance of platelet-derived microvesicles

    Dasgupta, Swapan K.; Abdel-Monem, Hanan; Niravath, Polly; Le, Anhquyen; Bellera, Ricardo V.; Langlois, Kimberly; Nagata, Shigekazu; Rumbaut, Rolando E.; Thiagarajan, Perumal

    2009-01-01

    The transbilayer movement of phosphatidylserine from the inner to the outer leaflet of the membrane bilayer during platelet activation is associated with the release of procoagulant phosphatidylserine-rich small membrane vesicles called platelet-derived microvesicles. We tested the effect of lactadherin, which promotes the phagocytosis of phosphatidylserine-expressing lymphocytes and red blood cells, in the clearance of platelet microvesicles. Platelet-derived microvesicles were labeled with ...

  18. Apoptotic clearance in rabbits with experimental pulmonary emphysema

    Žunić-Božinovski Snežana; Žunić Svetlana; Mladenović-Đorđević Aleksandra; Ruždijić Sabera; Kanazir Selma

    2011-01-01

    In order to better understand pathogenesis of pulmonary emphysema, the model of experimentally induced pulmonary emphysema in Chinchilla rabbits was used for the estimation of apoptotic clearance of pulmonary tissue. Bronchoalveolar lavage was performed in three groups of animals: experimental group-E on hypercholesterolemic diet (4% edible oil solution of crystalline cholesterol), control group-C1 on standard diet for that animal species and animals on oil...

  19. Early clearance of pneumococci from the lungs of decomplemented rats.

    Rehm, S R; Coonrod, J D

    1982-01-01

    Pneumococcal types which exhibited varying degrees of interaction with the complement system in vitro wee aerosolized into normal and decomplemented rats, and the rate of killing of pneumococci was monitored by serial cultures of whole lung homogenates. The clearance of pneumococci from the alveoli did not correlate with the ability of the pneumococci to be opsonized by complement in vitro. Similarly, rats depleted of complement in the serum and the bronchoalveolar lavage fluid maintained the...

  20. Mine clearance industry: background, geography, funding, analysis and future projections

    Donmez, Erkan

    2007-01-01

    MBA Professional Report Approved for public release; distribution is unlimited Contrary to common belief, the problems caused by landmines or other counter mobility devices have been threatening the lives of human beings for thousands of years. However, the actual efforts to remove the buried mines are a comparatively new issue. The mine clearance industry has been growing steadily, mostly because of increasing demand from the mine-afflicted countries, NGOs, international organizati...

  1. Highly Catalytic Nanodots with Renal Clearance for Radiation Protection

    Zhang, Xiao-Dong; Zhang, Jinxuan; Wang, Junying; Yang, Jiang; Chen, Jie; Shen, Xiu; Deng, Jiao; Deng, Dehui; Long, Wei; Sun, Yuan-Ming; Liu, Changlong; Li, Meixian

    2016-01-01

    Ionizing radiation (gamma and x-ray) is widely used in industry and medicine, but it can also pose a significant hazardous effect on health and induce cancer, physical deformity and even death, due to DNA damages and invasion of free radicals. There is therefore an urgent unmet demand in designing highly efficient radioprotectants with synergetic integration of effective renal clearance and low toxicity. In this study, we designed ultrasmall (sub-5 nm) highly catalytically active and cysteine...

  2. Lung Clearance Index bei erwachsenen Patienten mit Mukoviszidose

    Rückel, Helena Sophie

    2011-01-01

    Die Spirometrie mit Bestimmung des forcierten exspiratorischen Volumens in einer Sekunde gilt derzeit als Gold-Standard bei der Beurteilung der Lungenfunktion von Patienten mit Cystischer Fibrose. Da die spirometrische Untersuchung eine aktive Mitarbeit des Patienten erfordert, kann sie jedoch erst etwa ab dem fünften Lebensjahr durchgeführt werden. Im Gegensatz dazu kann der Lung Clearance Index (LCI), der aus Gasdilutionsuntersuchungen abgeleitet wird, in jedem Alter, d.h. auch im Säugl...

  3. Guangzhou Customs Guide to "Local Declaration & Port Clearance"

    2009-01-01

    @@ Ⅰ.Characteristic of the supervision mode of "Local Declaration & Port Clearance" This new mode means that the consignor,consignee or agent (hereafter referred to as "declarant") could choose any competent customs under the jurisdiction of Guangzhou Customs to make declaration and go through the formalities of document-checking and duty-paying,and then finish the cargo-examination and cargo-release at the customs office of entry or exit.

  4. Hepatic plasma clearance of 99mTc-HEPIDA as a diagnostic tool: experimentally derived equations for a simplified determination

    Determination of the plasma (ClPl) and specific hepatic clearance (ClHp) of 99mTc-HEPIDA is gaining acceptance as one of the best tests for the assessment of liver parenchyma functional capacity. A standard method utilises numerous blood samples,collected after injection of the radiopharmaceutical, plus collection of the urine if specific hepatic clearance is required. It is not always necessary to obtain values of the clearances by means of the laborious multi-sample procedure. In the paper there are presented formulas,based on experimental data, that form the basis of a simplified method for determination of ClPl and ClHp using single administration of 99mTc-HEPIDA. To arrive at the value of ClPl it is sufficient to withdraw 1 blood sample in the time range of 60 to 83 min post administration of the radio-pharmaceutical. If ClHp is required, additional collection of urine over the time from 0 to 88-100 min post injection is necessary. The values of ClPl and ClHp obtained by the simplified procedure are in full accordance with those obtained by the reference method utilising a series of blood samples, collected from 5 to 90 min post injection. The simplified method is sufficient as a procedure for screening of patients for liver parenchymal damage. (author)

  5. Relationship Between Tongue Base Region Pressures and Vallecular Clearance.

    Knigge, Molly A; Thibeault, Susan

    2016-06-01

    Tongue base pressures have been thought to provide primary bolus clearance through the pharynx during swallowing. The relationship between bolus driving pressures and residue remaining in the valleculae after the swallow has not been defined. Thirty-seven dysphagic patients who were evaluated with both videofluoroscopy (VFSS) and high-resolution manometry (HRM) were identified within the University of Wisconsin Voice and Swallowing Outcomes database. Patients were categorized according to binary ratings of presence or absence of vallecular stasis as well as incomplete or complete tongue retraction on VFSS. Tongue base region pressures measured with HRM during saline swallows of 1 and 10 ml volumes were compared to ratings of vallecular stasis or tongue base retraction. No significant difference could be identified among mean peak HRM pressures when compared to presence or absence of vallecular stasis (1 ml saline: p = .1886; 10 ml saline: p = .7354). When categorized according to complete or incomplete tongue retraction, mean peak HRM pressures were significantly greater in the complete tongue retraction group as compared to incomplete tongue retraction (1 ml saline: p = .0223; 10 ml saline: p = .0100). Findings suggest there are multiple factors that lead to reduced vallecular clearance. In the absence of HRM measures, judging complete or incomplete tongue retraction on VFSS may be a more valid gauge of tongue base region pressures than vallecular clearance when planning dysphagia treatment. PMID:26796743

  6. Smoking produced mucus and clearance of particulates in the lung

    Some studies of miners have shown a lesser relative lung-cancer risk for smokers than for nonsmokers. For example, experiments by Cross and associates with dogs have shown an apparent protective effect of cigarette smoke against radon-daughter and dust exposure. One reason for these changes may be the thickened mucus layer in the tracheobronchial region of smokers. Physiological changes in the lung due to smoking may decrease the effects of radioactive particles in cancers in the bronchial region by apparently promoting faster clearance, in that region, of radioactive particles and by decreasing the radiation dose through reduced penetration to the sensitive basal epithelial cells. Because of the short half-life of radon daughters, even if there is possible tobacco-related delay of particle clearance from the alveolar region it cannot affect radon clearance. Therefore, the possible mitigating effect of tobacco on radon-produced cancer appears to be limited to the tracheobronchial region. It would be of value to a number of occupations if the same changes in the lungs due to smoking could be produced in exposed workers in the absence of cigarette-smoking. Beta-carotene and vitamin A, which affect maintenance and secretion of the mucosal lining, appear to thicken mucus, thereby providing protection against radon-induced lung cancers that is similar to smoking-related changes in the lung

  7. Respirable industrial fibres: deposition, clearance and dissolution in animal models.

    Jones, A D

    1993-04-01

    This paper examines the available experimental and theoretical results describing deposition and clearance of mineral fibres inhaled by animals and humans in order to define the limits which these mechanisms impose on the relevance of animal experiments in the assessment of potential human health risks. Direct experimental data for deposition of spherical particles are extended by examination of the physical processes and by some limited experimental data for fibres. This shows that alveolar deposition efficiency (in rat and in man) is sufficiently similar for particles and fibres with aerodynamic diameters less that 5 microns for rats to be a relevant model for airborne dusts in this size range. Inter-species differences in mechanical clearance are substantial, with clearance being faster in the rat than in man, and this is a factor which should be considered in interpreting animal toxicity studies. The durability of fibres in the biochemical conditions of the lung may be more important over the longer lifespan of humans. PMID:8317856

  8. Dysregulation of Nutrient Sensing and CLEARance in Presenilin Deficiency

    Kavya Reddy

    2016-03-01

    Full Text Available Attenuated auto-lysosomal system has been associated with Alzheimer disease (AD, yet all underlying molecular mechanisms leading to this impairment are unknown. We show that the amino acid sensing of mechanistic target of rapamycin complex 1 (mTORC1 is dysregulated in cells deficient in presenilin, a protein associated with AD. In these cells, mTORC1 is constitutively tethered to lysosomal membranes, unresponsive to starvation, and inhibitory to TFEB-mediated clearance due to a reduction in Sestrin2 expression. Normalization of Sestrin2 levels through overexpression or elevation of nuclear calcium rescued mTORC1 tethering and initiated clearance. While CLEAR network attenuation in vivo results in buildup of amyloid, phospho-Tau, and neurodegeneration, presenilin-knockout fibroblasts and iPSC-derived AD human neurons fail to effectively initiate autophagy. These results propose an altered mechanism for nutrient sensing in presenilin deficiency and underline an importance of clearance pathways in the onset of AD.

  9. RENAL CLEARANCE AND URINARY EXCRETION OF CIPROFLOXACIN IN GOATS

    Z. IQBAL, I. JAVED, B. ASLAM, F. MUHAMMAD AND I. U. JAN

    2007-10-01

    Full Text Available The renal clearance and urinary excretion of ciprofloxacin were investigated in eight healthy female goats. In each animal, ciprofloxacin was administered intramuscularly at the rate of 5 mg/kg body weight. Following drug administration, blood and urine samples were collected at different time intervals and analyzed for ciprofloxacin and creatinine. High performance liquid chromatography (HPLC was used to determine the drug concentration in the plasma and urine. The value of diuresis after single administration of ciprofloxacin was 0.073 ± 0.014 ml/min/kg. Mean (± SE values for renal clearance of creatinine and ciprofloxacin were 1.870 ± 0.385 and 0.982 ± 0.166 ml/min/kg, respectively. The ratio between the renal clearance of ciprofloxacin and that of creatinine remained less than one, which was indicative of back diffusion. The mean (± SE value for the cumulative percent of ciprofloxacin dose excreted at 10 hours following its intramuscular administration was 13.03 ± 2.07. Based on these results, it was evident that besides glomerular filtration, renal handling of drug involved back diffusion also. It was concluded that in local goats glomerular filtration rate (GFR was lower than that reported for their foreign counterparts.

  10. Dysregulation of Nutrient Sensing and CLEARance in Presenilin Deficiency.

    Reddy, Kavya; Cusack, Corey L; Nnah, Israel C; Khayati, Khoosheh; Saqcena, Chaitali; Huynh, Tuong B; Noggle, Scott A; Ballabio, Andrea; Dobrowolski, Radek

    2016-03-01

    Attenuated auto-lysosomal system has been associated with Alzheimer disease (AD), yet all underlying molecular mechanisms leading to this impairment are unknown. We show that the amino acid sensing of mechanistic target of rapamycin complex 1 (mTORC1) is dysregulated in cells deficient in presenilin, a protein associated with AD. In these cells, mTORC1 is constitutively tethered to lysosomal membranes, unresponsive to starvation, and inhibitory to TFEB-mediated clearance due to a reduction in Sestrin2 expression. Normalization of Sestrin2 levels through overexpression or elevation of nuclear calcium rescued mTORC1 tethering and initiated clearance. While CLEAR network attenuation in vivo results in buildup of amyloid, phospho-Tau, and neurodegeneration, presenilin-knockout fibroblasts and iPSC-derived AD human neurons fail to effectively initiate autophagy. These results propose an altered mechanism for nutrient sensing in presenilin deficiency and underline an importance of clearance pathways in the onset of AD. PMID:26923592

  11. Antibody response following Hepatitis B vaccination in peritoneal dialysis patients: does normalized urea clearance matter?

    Erkan Dervisoglu

    2011-01-01

    Full Text Available OBJECTIVES: Data on the factors that contribute to the antibody response to hepatitis B virus vaccination in peritoneal dialysis patients are scarce. The current study was conducted on a group of peritoneal dialysis patients to learn how the response to hepatitis B virus vaccination varies according to the patient's clearance of urea normalized to total body water (Kt/V. METHODS: A convenience sample of 33 peritoneal dialysis patients (13 women and 20 men, with a mean age of 49¡12 years was administered double doses (20 μg IM in each deltoid muscle of recombinant hepatitis B vaccine at 0, 1, 2, and 6 months. Response to immunization was measured at one to three months after the final dose of vaccine. The subjects were divided into groups according to the level of antibodies to hepatitis B surface antigen (anti-HBs, including non-responders ( 100 IU/L. RESULTS: Among non-responders, weak responders, and good responders, significant differences were found in age (54 ± 12 vs. 56 ± 9 vs. 45¡12 years, respectively; p = 0.049 and recombinant human erythropoietin use (20 vs. 29 vs. 76%, respectively; p = 0.016. No significant differences in weekly total Kt/V (p = 0.704, weekly peritoneal Kt/V (p = 0.064 and residual glomerular filtration rate (p = 0.355 were found across the three groups. CONCLUSIONS: Delivered clearance measured by weekly peritoneal Kt/V and total clearance measured by weekly total Kt/V did not predict the response to hepatitis B virus vaccination in patients on peritoneal dialysis.

  12. Improving accuracy of ET measurement of LISS nozzle to calandria tube clearance

    Craig, S.T.; Krause, T.W.; Schankula, J.J. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)]. E-mail: craigs@aecl.ca

    2006-07-01

    The AECL Fuel Channel Inspection System (AFCIS) has been used in an in-reactor field trial to successfully measure the clearance between Liquid Injection Shutdown System (LISS) nozzles and calandria tubes. Each measurement over the full length of a channel added only 15 minutes to the on-channel inspection time. No changes were required to the inspection heads. The only equipment changes made were the addition of a Remote Field Eddy Current (RFEC) module to the eddy current instrument, and minor wiring changes, at the instrument, to achieve a RFEC configuration. With the experience gained from the field trial, factors potentially limiting accuracy were identified. These, and other factors, were investigated and are discussed herein. The RFEC probe is delivered inside the pressure tube. Magnetic fields from the RFEC probe extend through the conducting walls of the pressure tube and calandria tube to interact with the LISS nozzle. Data acquired during the field trial showed the LISS nozzle signal is distinct and the signal-to-noise ratio is very favourable. Nevertheless, comparison of the RFEC measurements to a visual examination, made during the same outage, had the RFEC method underestimating the clearance by 2.5 mm on average. By way of laboratory tests, the following factors were investigated as potential sources of error: resistivity and geometry of LISS nozzle reference/calibration pieces, pressure-tube wall thickness, diameter and resistivity variations, pressure-tube to calandria-tube gap, and radial offsets of the probe within the pressure-tube. The sensitivity to these various noise sources was established. A model, based on fundamental electromagnetic principles, was developed and was used to normalize the effects of LISS nozzle conductivity and geometry. This enabled compensation for various sources of error, and made it possible to produce a correction factor for the field trial data, reducing the average difference from the visual inspection of LISS

  13. Impact of variable domain glycosylation on antibody clearance: an LC/MS characterization.

    Huang, Lihua; Biolsi, Susan; Bales, Kelly R; Kuchibhotla, Uma

    2006-02-15

    Variable (Fv) domain N-glycosylation sites are found in approximately 20% of human immunoglobulin Gs (IgGs) in addition to the conserved N-glycosylation sites in the C(H)2 domains. The carbohydrate structures of the Fv glycans and their impact on in vivo half-life are not well characterized. Oligosaccharide structures in a humanized anti-Abeta IgG1 monoclonal antibody (Mab) with an N-glycosylation site in the complementary determining region (CDR2) of the heavy chain variable region were elucidated by LC/MS analysis following sequential exoglycosidase treatments of the endoproteinase Lys-C digest. Results showed that the major N-linked oligosaccharide structures in the Fv region have three characteristics (core-fucosylated biantennary oligosaccharides with one or two N-glycolylneuraminic acid [NeuGc] residues, zero or one alpha-linked Gal residue, and zero or one beta-linked GalNAc residue), whereas N-linked oligosaccharides in the Fc region contained typical Fc glycans (core-fucosylated, biantennary oligosaccharides with zero to two Gal residues). To elucidate the contribution of Fv glycans to the half-life of the antibody, a method that allows capture of the Mab and determination of its glycan structures at various time points after administration to mice was developed. Anti-Abeta antibody in mouse serum was immunocaptured by immobilized goat anti-human immunoglobulin Fc(gamma) antibody resin, and the captured material was treated with papain to generate Fab and Fc for LC/MS analysis. Different glycans in the Fc region showed the same clearance rate as demonstrated previously. In contrast to many other non-antibody glycosylated therapeutics, there is no strong correlation between oligosaccharide structures in the Fv region and their clearance rates in vivo. Our data indicated that biantennary oligosaccharides lacking galactosylation had slightly faster clearance rates than other structures in the Fv domain. PMID:16360109

  14. Mapping soil magnetic properties in Bosnia and Herzegovina for landmine clearance operations

    Hannam, J. A.; Dearing, J. A.

    2008-10-01

    Electromagnetic properties of soils have negative impacts on metal detector performance during landmine clearance operations. In particular, topsoils with high concentrations of pedogenic viscous superparamagnetic minerals (magnetite/maghemite) as shown by high values of magnetic susceptibility and frequency dependent susceptibility limit the detector capability of identifying buried landmines. Thus a priori knowledge of the spatial extent of soils that may be problematic for landmine detection would aid strategic planning of clearance operations and ensure appropriate equipment is deployed. Here, we compare two approaches for estimating the broad magnetic properties of soils in Bosnia and Herzegovina: 1) an analogue approach, using data for magnetic susceptibility and frequency dependent susceptibility available for soil types from other temperate and Mediterranean regions; 2) magnetic measurements of a stratified sample of soil samples taken from the Bosnian National Soil Archive. The national soil magnetic maps produced estimate that the area of land inferred as problematic for metal detectors is 4% and 30% according to the analogue and measurement methods respectively. Combining soil type with soil parent material and climate explains the spatial variability of soil magnetic properties in terms of mechanisms of secondary ferrimagnetic mineral production and accumulation. The resulting maps indicate that the magnetic properties of dominant soils in northern Bosnia tend to be unproblematic for detectors, while in central Bosnia there is likely to be moderate detector interference. However, there is a high likelihood of dominant soils affecting detectors in southern and western Bosnia and Herzegovina, equivalent to ~ 30% of the total land area. The mapped outputs of susceptibility and frequency dependent susceptibility provide demining end-users with an indication of the likelihood of encountering problem soils in areas selected for clearance operations.

  15. Abnormal norepinephrine clearance and adrenergic receptor sensitivity in idiopathic orthostatic intolerance

    Jacob, G.; Shannon, J. R.; Costa, F.; Furlan, R.; Biaggioni, I.; Mosqueda-Garcia, R.; Robertson, R. M.; Robertson, D.

    1999-01-01

    BACKGROUND: Chronic orthostatic intolerance (OI) is characterized by symptoms of inadequate cerebral perfusion with standing, in the absence of significant orthostatic hypotension. A heart rate increase of >/=30 bpm is typical. Possible underlying pathophysiologies include hypovolemia, partial dysautonomia, or a primary hyperadrenergic state. We tested the hypothesis that patients with OI have functional abnormalities in autonomic neurons regulating cardiovascular responses. METHODS AND RESULTS: Thirteen patients with chronic OI and 10 control subjects underwent a battery of autonomic tests. Systemic norepinephrine (NE) kinetics were determined with the patients supine and standing before and after tyramine administration. In addition, baroreflex sensitivity, hemodynamic responses to bolus injections of adrenergic agonists, and intrinsic heart rate were determined. Resting supine NE spillover and clearance were similar in both groups. With standing, patients had a greater decrease in NE clearance than control subjects (55+/-5% versus 30+/-7%, P<0.02). After tyramine, NE spillover did not change significantly in patients but increased 50+/-10% in control subjects (P<0.001). The dose of isoproterenol required to increase heart rate 25 bpm was lower in patients than in control subjects (0.5+/-0.05 versus 1.0+/-0.1 microg, P<0.005), and the dose of phenylephrine required to increase systolic blood pressure 25 mm Hg was lower in patients than control subjects (105+/-11 versus 210+/-12 microg, P<0.001). Baroreflex sensitivity was lower in patients (12+/-1 versus 18+/-2 ms/mm Hg, P<0.02), but the intrinsic heart rate was similar in both groups. CONCLUSIONS: The decreased NE clearance with standing, resistance to the NE-releasing effect of tyramine, and increased sensitivity to adrenergic agonists demonstrate dramatically disordered sympathetic cardiovascular regulation in patients with chronic OI.

  16. Effects of radiosensitising agent nicotinamide on relative tissue perfusion and kidney junction in C3H mice

    Nicotinamide is an effective radiosensitiser of murine tumours, functioning by improving tumour perfusion by decreasing the proportion of intermittently closed capillaries. The effect of nicotinamide on relative tissue perfusion of RIF-1 tumour and normal skin, muscle, lung, liver, kidney and spleen were investigated using the 86Rb extraction technique. A dose of 1000 mg/kg was shown to have transient effects on tumour, skin and lung perfusion but to have sustained effects on muscle (a drop to 80% of control), liver, kidney and spleen (with increased ranging from 165% to 280% of control) from 0.5 to 4 h after treatment i.e. during the period of maximum radiosensitisation. These increases were evident at doses as low as 100 mg/kg. The data suggest that the radiosensitisation induced by nicotinamide in the mouse may be associated with these perfusion changes. Nicotinamide was also shown to have a substantial inhibitory effect on renal function, inhibiting 51CrEDTA clearance by a factor (± 2 SE) of 2.56 ± 0.19 and 125I-iodohippurate clearance by a factor of 2.07 ± 0.45 at 1000 mg/kg. These effects were shown to be dose-related, and to be evident at doses from 400 mg/kg upwards. This suggests that nicotinamide potentiation of co-administered cytotoxic agents may be mediated by reduced renal clearance of the cytotoxic drug, thus increasing the plasma half-life. (author)

  17. Numerical investigation of tip clearance effects on the performance of ducted propeller

    Yongle, Ding; Baowei, Song; Peng, Wang

    2015-09-01

    Tip clearance loss is a limitation of the improvement of turbomachine performance. Previous studies show the Tip clearance loss is generated by the leakage flow through the tip clearance, and is roughly linearly proportional to the gap size. This study investigates the tip clearance effects on the performance of ducted propeller. The investigation was carried out by solving the Navier-Stokes equations with the commercial Computational Fluid Dynamic (CFD) code CFX14.5. These simulations were carried out to determine the underlying mechanisms of the tip clearance effects. The calculations were performed at three different chosen advance ratios. Simulation results showed that the tip loss slope was not linearly at high advance due to the reversed pressure at the leading edge. Three type of vortical structures were observed in the tip clearance at different clearance size.

  18. Numerical investigation of tip clearance effects on the performance of ducted propeller

    Yongle Ding

    2015-09-01

    Full Text Available Tip clearance loss is a limitation of the improvement of turbomachine performance. Previous studies show the Tip clearance loss is generated by the leakage flow through the tip clearance, and is roughly linearly proportional to the gap size. This study investigates the tip clearance effects on the performance of ducted propeller. The investigation was carried out by solving the Navier-Stokes equations with the commercial Computational Fluid Dynamic (CFD code CFX14.5. These simulations were carried out to determine the underlying mechanisms of the tip clearance effects. The calculations were performed at three different chosen advance ratios. Simulation results showed that the tip loss slope was not linearly at high advance due to the reversed pressure at the leading edge. Three type of vortical structures were observed in the tip clearance at different clearance size.

  19. Transient proteolytic modification of mesenchymal stromal cells increases lung clearance rate and targeting to injured tissue.

    Kerkelä, Erja; Hakkarainen, Tanja; Mäkelä, Tuomas; Raki, Mari; Kambur, Oleg; Kilpinen, Lotta; Nikkilä, Janne; Lehtonen, Siri; Ritamo, Ilja; Pernu, Roni; Pietilä, Mika; Takalo, Reijo; Juvonen, Tatu; Bergström, Kim; Kalso, Eija; Valmu, Leena; Laitinen, Saara; Lehenkari, Petri; Nystedt, Johanna

    2013-07-01

    Systemic infusion of therapeutic cells would be the most practical and least invasive method of administration in many cellular therapies. One of the main obstacles especially in intravenous delivery of cells is a massive cell retention in the lungs, which impairs homing to the target tissue and may decrease the therapeutic outcome. In this study we showed that an alternative cell detachment of mesenchymal stromal/stem cells (MSCs) with pronase instead of trypsin significantly accelerated the lung clearance of the cells and, importantly, increased their targeting to an area of injury. Cell detachment with pronase transiently altered the MSC surface protein profile without compromising cell viability, multipotent cell characteristics, or immunomodulative and angiogenic potential. The transient modification of the cell surface protein profile was sufficient to produce effective changes in cell rolling behavior in vitro and, importantly, in the in vivo biodistribution of the cells in mouse, rat, and porcine models. In conclusion, pronase detachment could be used as a method to improve the MSC lung clearance and targeting in vivo. This may have a major impact on the bioavailability of MSCs in future therapeutic regimes. PMID:23734061

  20. Transient Proteolytic Modification of Mesenchymal Stromal Cells Increases Lung Clearance Rate and Targeting to Injured Tissue

    Hakkarainen, Tanja; Mäkelä, Tuomas; Raki, Mari; Kambur, Oleg; Kilpinen, Lotta; Nikkilä, Janne; Lehtonen, Siri; Ritamo, Ilja; Pernu, Roni; Pietilä, Mika; Takalo, Reijo; Juvonen, Tatu; Bergström, Kim; Kalso, Eija; Valmu, Leena; Laitinen, Saara; Lehenkari, Petri; Nystedt, Johanna

    2013-01-01

    Systemic infusion of therapeutic cells would be the most practical and least invasive method of administration in many cellular therapies. One of the main obstacles especially in intravenous delivery of cells is a massive cell retention in the lungs, which impairs homing to the target tissue and may decrease the therapeutic outcome. In this study we showed that an alternative cell detachment of mesenchymal stromal/stem cells (MSCs) with pronase instead of trypsin significantly accelerated the lung clearance of the cells and, importantly, increased their targeting to an area of injury. Cell detachment with pronase transiently altered the MSC surface protein profile without compromising cell viability, multipotent cell characteristics, or immunomodulative and angiogenic potential. The transient modification of the cell surface protein profile was sufficient to produce effective changes in cell rolling behavior in vitro and, importantly, in the in vivo biodistribution of the cells in mouse, rat, and porcine models. In conclusion, pronase detachment could be used as a method to improve the MSC lung clearance and targeting in vivo. This may have a major impact on the bioavailability of MSCs in future therapeutic regimes. PMID:23734061