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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.

    PubMed

    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. Absolute 24 h quantification of 99Tcm-DMSA uptake in patients with severely reduced kidney function: a comparison with 51Cr-EDTA clearance.

    PubMed

    van de Wiele, C; van den Eeckhaut, A; Verweire, W; van Haelst, J P; Versijpt, J; Dierckx, R A

    1999-09-01

    The aim of this study was to determine whether absolute 24 h DMSA uptake measurements (%DMSA) correlate well with 51Cr-EDTA clearance measurements in patients with severely reduced kidney function (SRKF). Between 1990 and 1997, 55 of 482 patients who underwent EDTA clearance measurements also underwent %DMSA within 1 week. Of these, 31 were women and 24 were men (mean age 60 years; range 19-77 years). EDTA clearance was determined using the slope-intercept method. Absolute depth- and background-corrected %DMSA were determined 24 h following the injection of 185 MBq per 1.73 m2 freshly prepared 99Tcm-DMSA. All patients had EDTA clearance < or = 60 ml.min-1. Eighteen patients (group A: 9 men and 9 women, mean age 55.8 years, range 28-73 years) had EDTA clearance > 20 ml.min-1 (mean +/- S.D. = 30.9 +/- 13.8 ml.min-1), whereas 37 patients (group B: 22 women and 15 men, mean age 62.0 years, range 19-77 years) had EDTA clearance < 20 ml.min-1 (mean +/- S.D. = 10.2 +/- 6.6 ml.min-1). EDTA clearance correlated well with %DMSA for the patients as a whole and for group A (r = 0.87, P = 0.73; r = 0.79, P = 0.0001 respectively). The regression equation suggests that %DMSA is not a marker of early renal dysfunction. In group B, the r-value (r = 0.48, P = 0.004) suggests that %DMSA is reliable as a marker of severe renal dysfunction to the extent that it provides rough information. In conclusion, %DMSA may not be used as a marker of early renal impairment. Additionally, in patients with severely reduced kidney function (EDTA clearance < 20 ml.min-1), it only provides a rough estimate.

  3. 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.

    PubMed

    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

  4. Assessment of glomerular filtration rate utilizing subcutaneously injected 51Cr-EDTA.

    PubMed

    Monteiro, M C; Alonso, G; Ajzen, H; Pereira, A B

    1994-11-01

    1. 51Cr-EDTA injected with lidocaine and epinephrine, as a subcutaneous button, is slowly absorbed, and a plasma level that is relatively stable can be maintained for a time sufficient to permit measurement of the renal clearance of EDTA, which is a measure of glomerular filtration rate (GFR). We studied this procedure in 32 normal volunteers and 24 patients with different glomerulopathies, comparing EDTA and creatinine clearances. In 20 patients these measurements were also compared with inulin clearance. 2. Creatinine clearance overestimates GFR due to tubular secretion of creatinine. This secretion is present even in patients with significantly reduced glomerular filtration rates. As a consequence, the lower the GFR the higher the overestimation will be. 3. A good correlation was obtained between the 51Cr-EDTA and inulin clearance: y(EDTA) = 4.21 + 0.88 x (inulin), r = 0.98. The procedure is simple to perform, and the radiotracer utilized is significantly less expensive than iothalamate. PMID:7549976

  5. (51Cr)EDTA intestinal permeability in children with cow's milk intolerance

    SciTech Connect

    Schrander, J.J.; Unsalan-Hooyen, R.W.; Forget, P.P.; Jansen, J. )

    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.

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

    SciTech Connect

    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.

  7. Intestinal permeability to (/sup 51/Cr)EDTA in children with cystic fibrosis

    SciTech Connect

    Leclercq-Foucart, J.; Forget, P.; Sodoyez-Goffaux, F.; Zappitelli, A.

    1986-05-01

    Intestinal permeability was investigated in 14 children with cystic fibrosis making use of (/sup 51/Cr)EDTA as probe molecule. Ten normal young adults and 11 children served as controls. After oral administration of (/sup 51/Cr)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).

  8. Application of the 51Cr-EDTA urinary recovery test for assessment of intestinal permeability in the horse.

    PubMed

    Escala, J; Gatherer, M E; Voûte, L; Love, S

    2006-04-01

    Altered intestinal permeability is implicated in the pathogenesis of diverse equine medical conditions including alimentary laminitis and protein-losing enteropathies associated with parasitic infection. The aims of this study were to assess the feasibility of applying the 51Cr-EDTA absorption test for the assessment of intestinal permeability in the horse, and to apply this test in horses with experimentally induced alterations in gastrointestinal function. Four healthy ponies were administered 36 MBq of 51Cr-EDTA via naso-gastric tube, and urine samples were collected into polythene bags strapped to the pony's abdomen. Total urine voided every 6 h was collected during each test, and 1 ml samples were taken for measurement of gamma-radiation. Urinary recovery of 51Cr-EDTA was measured following intravenous atropine sulphate or bethanecol, and following 22 and 46 days of administration of 250,000 third-stage cyathostome larvae. There was no significant difference in urinary 51Cr-EDTA recovery following the control treatment, and following atropine or bethanecol administration, but significant increases were detected in the animals with experimental cyathostome infection consistent with increased permeability of the intestinal membrane. Motility modifying agents (bethanecol and atropine) did not affect absorption of 51Cr-EDTA, suggesting that subtle changes in motility might not affect the ability of this test to detect altered intestinal permeability. The finding of increased urinary recovery of 51Cr-EDTA in ponies with cyathostome infection suggests that 51Cr-EDTA may be a useful marker for assessment of intestinal permeability in the horse.

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

    SciTech Connect

    Jenkins, R.T.; Jones, D.B.; Goodacre, R.L.; Collins, S.M.; Coates, G.; Hunt, R.H.; Bienenstock, J.

    1987-11-01

    Intestinal permeability in adults with inflammatory gastrointestinal diseases was investigated by measuring the 24-h urinary excretion of orally administered /sup 51/Cr-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 /sup 51/Cr-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.

  10. Permeability of the small intestine to (/sup 51/Cr)EDTA in children with acute gastroenteritis or eczema

    SciTech Connect

    Forget, P.; Sodoyez-Goffaux, F.; Zappitelli, A.

    1985-06-01

    Increased gut permeability to macromolecules is thought to be an important factor in the development of food hypersensitivity. The latter can develop in the course of acute gastroenteritis and could play a role in infantile eczema. The authors studied gut permeability in 10 normal adults, 11 control children, 7 children with acute gastroenteritis, and 8 patients with infantile eczema, making use of (/sup 51/Cr)EDTA as probe molecule. (/sup 51/Cr)EDTA was given orally (50-100 microCi); 24-h urinary excretion of (/sup 51/Cr)EDTA was measured and expressed as a percentage of the oral dose. Mean and standard error were 2.35 +/- 0.24, 2.51 +/- 0.21, 9.96 +/- 3.44, and 10.90 +/- 2.05 in normal adults, control children, and gastroenteritis and eczema patients, respectively. Differences between controls and either gastroenteritis (p less than 0.001) or eczema (p less than 0.001) patients are significant. The results support the hypothesis that increased gut permeability could play a role in food hypersensitivity.

  11. Lowering of tumoral interstitial fluid pressure by prostaglandin E(1) is paralleled by an increased uptake of (51)Cr-EDTA.

    PubMed

    Rubin, K; Sjöquist, M; Gustafsson, A M; Isaksson, B; Salvessen, G; Reed, R K

    2000-06-01

    High intra-tumoral fluid pressure (TP(IF)) may impair uptake of anticancer drugs into tumors, contributing to poor efficiency in treatment of carcinomas. Here, we demonstrate that lowering of TP(IF) parallels increased transport of (51)Cr-EDTA (m.w. 341) into tumor interstitium. Introduction of 15 microg prostaglandin E(1) (PGE(1)) -methyl ester into the s.c. tissue surrounding transplanted rat colonic (PROb) carcinomas or chemically-induced rat mammary carcinomas, lowered TP(IF) by 30%. Transcapillary transport into the interstitium of PROb tumors quantified by microdialysis increased by 39.6% after PGE(1) treatment 40 min prior to administration of (51)Cr-EDTA (n=6; p<0.05) compared to vehicle (n=10). In mammary tumors, PGE(1) increased transport into the tumors by 86.9% over controls (n=16; p<0.05). Both tumors had well developed stroma containing collagen and hyaluronan. Our data demonstrate that adjuvant treatment with PGE(1) lowers TP(IF), and enhances transport into the tumors. This principle may be of value as adjuvant therapy in treatment of solid malignancies with currently used anticancer drugs.

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

    SciTech Connect

    Mattsson, S.; Johansson, L.; Nosslin, B.; Ahlgren, L.

    1981-06-01

    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 /sup 125/I-fibrinogen, from two patients after administration of /sup 99/Tc/sup m/-macroaggregated albumin, and from one patient after administration of /sup 51/Cr-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.

  13. Respiratory clearance of aerosolized radioactive solutes of varying molecular weight

    SciTech Connect

    Huchon, G.J.; Montgomery, A.B.; Lipavsky, A.; Hoeffel, J.M.; Murray, J.F.

    1987-05-01

    To determine the influence of varying molecular weight (mol wt) on respiratory clearance of aerosolized solutes, we studied eight radiopharmaceuticals, each administered to four dogs: sodium /sup 99m/Tc pertechnetate (TcO4), /sup 99m/Tc glucoheptonate ((/sup 99m/Tc)GH), 51Cr-ethylenedinitrotetraacetate ((51Cr)EDTA), /sup 99m/Tc diethylenetriaminepentaacetate ((99mTc) DTPA), /sup 111/In diethylenetriaminepentaacetate ((/sup 111/In)DTPA), /sup 67/Ga desferoxaminemesylate ((/sup 67/Ga)DFOM), /sup 99m/Tc dextran ((/sup 99m/Tc)DX) and /sup 111/In transferrin ((/sup 111/In)TF). After aerosolization (0.8 m MMD, 2.4 GSD), clearance was determined for 30 min and then corrected by intravenous injection for nonairspace radioactivity. In-TF clearance (0.11 +/- 0.10%/min) was lower than TcO4 (6.32 +/- 0.62%/min), (/sup 99m/Tc)GH (1.50 +/- 0.37%/min), (/sup 51/Cr)EDTA (2.38 +/- 1.02%/min), (/sup 99m/Tc)DTPA (3.51 +/- 0.40%/min), (/sup 111/In)DTPA (2.35 +/- 0.42%/min), (/sup 67/Ga) DFOM (1.99 +/- 0.49%/min) and (/sup 99m/Tc)DX (1.81 +/- 0.75%/min) clearances (p less than 0.001). TcO4 clearance was higher than others (p less than 0.001). Technetium binding to DX was unsatisfactory; aerosolization caused unbinding from DTPA. We conclude that respiratory clearance of large mol wt solutes within 30 min is negligible and, that clearance of molecules between 347-5099 daltons differs greatly, suggesting that binding and/or intrapulmonary retention affect transfer.

  14. Clearance detector and method for motion and distance

    DOEpatents

    Xavier, Patrick G.

    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.

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

    PubMed

    Henriksen, Ulrik L; Henriksen, Jens H

    2015-01-01

    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 between the total plasma clearance and the urinary plasma clearance. This is owing to delayed indicator distribution to smaller or larger parts of the interstitial space, which in patients with ascites may simulate a peritoneal dialysator. In patients with fluid retention, urinary plasma clearance should 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 patients with fluid retention have their GFR measured by a urinary plasma clearance technique with controlled quantitative urinary sampling within a few hours after indicator injection.

  16. Dependence of Cr-EDTA absorption from the rumen on luminal osmotic pressure.

    PubMed

    Dobson, A; Sellers, A F; Gatewood, V H

    1976-11-01

    A method for the measurement of [51Cr]EDTA absorption from the ventral sac of the rumen with an error of the order of +/-10% is described. When a solution present in the rumen was hypotonic or isotonic, the absorption rate of [51Cr]EDTA expressed as a clearance was about 0.2 ml/min. This gave rise to negligible errors when [51Cr]EDTA was used as an unabsorbed marker to calculate net water movements. When the osmotic pressure in the rumen exceeded that of plasma by 30-40 mos-mol/kg, the absorption rate of [51Cr]EDTA appeared to be related to the degree of hypertonicity. Absorption rates as high as 8 ml/min were observed within a range of osmotic pressures normally encountered postprandially in the rumen. Under hypertonic conditions, a correction for the absorption of this large anion was necessary if passage of water into the lumen were not to be systematically overestimated.

  17. Comparison of Two Alternate Methods for Tracking Toe Clearance

    NASA Technical Reports Server (NTRS)

    Miller, Christopher A.; Feiveson, Alan H.; Bloomberg, Jacob J.

    2007-01-01

    Analyses of toe clearance during the swing phase of locomotion has often been utilized in determining a subject s propensity to trip while either walking or stepping over an obstacle. In the literature, toe clearance has been studied using a marker on the superior aspect of the second toe (rtoe), a marker on the lateral aspect of the fifth metatarsal head (mth5), or a virtual marker positioned at the anterior tip of the toe (vtoe). The purpose of this study was to compute toe clearance and associated parameters using a fifth metatarsal marker and a virtual toe marker, and compare the results with those of the standard toe marker. Subjects walked on a motorized treadmill at five different speeds while performing a visual acuity task at two separate target distances (ten 60-second trials). The minimum vertical height (TCl) was determined for each stride, along with its point of occurence in the gait cycle, and the angles of the foot and ankle at that time. A regression analysis was performed on the vtoe and mth5 results versus rtoe individually. For all TCl parameters, the mth5 marker did not correlate well with rtoe; the vtoe marker showed better agreement. Most importantly, the mth5 marker predicted a later occurence of TCl than rtoe and vtoe - thereby missing the most dangerous point in swing phase for a trip. From this analysis, the vtoe marker proved to be a better analog to rtoe than mth5, especially for determining a subject s propensity to trip.

  18. Determination of renal clearances of amylase/creatinine with chromogenic and enzymatic methods.

    PubMed

    Hohenwallner, W; Wimmer, E; Sommer, R

    1979-12-01

    Urinary amylase was estimated by chromogenic (amylochrome Roche) as well as enzymatic methods (SKI and Beckman: substrate starch and substrate maltotetraose respectively). Random and timed urines (24 hour collections) were analysed. Clearances of amylase gave different results dependent upon the amylase-test used and the glomerular filtration rate. Correlation between chromogenic and enzymatic methods (starch as substrate) was poor. The ratio of amylase and creatinine clearance was used to test different methods. Reference values for this ratio for the amylochrome method (N = 106) were 2.85 +/- 0.99% and for the Beckman-DS method (N = 60) 2.82 +/- 0.87%.

  19. Pleural liquid clearance rate measured in awake sheep by the volume of dilution method

    SciTech Connect

    Broaddus, V.C.; Wiener-Kronish, J.P.; Berthiaume, Y.; Staub, N.C.

    1986-03-01

    The authors reported 24h clearance of mock pleural effusions measured terminally in sheep. To measure effusion volume at different times in the same sheep, they injected /sup 111/In-transferrin and measured its dilution. In 5 sheep with effusions of known sizes, the method was accurate to +/-10%. In 5 awake sheep, the authors injected 10 ml/kg of a 1% protein solution via a non-penetrating rib capsule. At 6h, the authors measured the volume by the dilution method and at 24h by direct recovery. The clearance rate in each animal was constant at 2.9-6.0%/h (average 4.8 +/- 1.3%/h). This new method gives a reliable two point clearance rate and requires fewer animals.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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.

  2. Bacterial clearance rate and a new differential hemocyte staining method to assess immunostimulant activity in shrimp.

    PubMed

    Sritunyalucksana, Kallaya; Gangnonngiw, Warachin; Archakunakorn, Somwit; Fegan, Daniel; Flegel, Timothy W

    2005-01-25

    New methods were developed to assess immunostimulant efficacy in the black tiger shrimp Penaeus monodon. Test shrimp were fed with 2 or 4 % yeast extract (YE)-coated feed while controls were fed non-coated feed. After 4 wk of feeding, individual shrimp were assessed for total hemocyte counts (THC), the number of granular hemocytes (GH) and rate of bacterial clearance. For hemocyte counts, formalin-fixed hemolymph was stained with 1.2 % Rose Bengal in 50 % ethanol for 20 min at room temperature. Some of this mixture was used for THC with a hemocytometer while some was smeared on a microscope slide and left to dry before counterstaining with hematoxylin for GH counts. By this technique, high quality smears were obtained for accurate differential counts. Bacterial clearance assays were used to assess the sum effect of humoral and cellular defense mechanisms. Vibrio harveyi was injected intramuscularly at 1 x 10(8) cells per shrimp and hemolymph was collected in anticoagulant at 0, 15, 30 and 60 min post-injection for quadruplicate drop counts (20 microl) on TCBS agar. Total hemocyte counts for shrimp fed with 4 % YE were significantly higher (p < 0.05) than those for shrimp fed with non-coated feed. The percentage of granular cells and the rates of bacterial clearance for the YE-fed shrimp were higher than those for shrimp fed the control diet. These 2 methods provide a simple and rapid comparison of shrimp groups for differences in anti-bacterial defense capacity.

  3. Reproducibility of CSF quantitative culture methods for estimating rate of clearance in cryptococcal meningitis.

    PubMed

    Dyal, Jonathan; Akampurira, Andrew; Rhein, Joshua; Morawski, Bozena M; Kiggundu, Reuben; Nabeta, Henry W; Musubire, Abdu K; Bahr, Nathan C; Williams, Darlisha A; Bicanic, Tihana; Larsen, Robert A; Meya, David B; Boulware, David R

    2016-05-01

    Quantitative cerebrospinal fluid (CSF) cultures provide a measure of disease severity in cryptococcal meningitis. The fungal clearance rate by quantitative cultures has become a primary endpoint for phase II clinical trials. This study determined the inter-assay accuracy of three different quantitative culture methodologies. Among 91 participants with meningitis symptoms in Kampala, Uganda, during August-November 2013, 305 CSF samples were prospectively collected from patients at multiple time points during treatment. Samples were simultaneously cultured by three methods: (1) St. George's 100 mcl input volume of CSF with five 1:10 serial dilutions, (2) AIDS Clinical Trials Group (ACTG) method using 1000, 100, 10 mcl input volumes, and two 1:100 dilutions with 100 and 10 mcl input volume per dilution on seven agar plates; and (3) 10 mcl calibrated loop of undiluted and 1:100 diluted CSF (loop). Quantitative culture values did not statistically differ between St. George-ACTG methods (P= .09) but did for St. George-10 mcl loop (P< .001). Repeated measures pairwise correlation between any of the methods was high (r≥0.88). For detecting sterility, the ACTG-method had the highest negative predictive value of 97% (91% St. George, 60% loop), but the ACTG-method had occasional (∼10%) difficulties in quantification due to colony clumping. For CSF clearance rate, St. George-ACTG methods did not differ overall (mean -0.05 ± 0.07 log10CFU/ml/day;P= .14) on a group level; however, individual-level clearance varied. The St. George and ACTG quantitative CSF culture methods produced comparable but not identical results. Quantitative cultures can inform treatment management strategies.

  4. Radioactive chromium-ethylenediaminetetraacetic acid for determination of glomerular filtration rate in rabbits

    SciTech Connect

    Tvedegaard, E.; Kamstrup, O.

    1981-12-01

    Simultaneous determination of the glomerular filtration rate was made by the insulin clearance technique and by analysis of the plasma disappearance curve of radioactive chromium-ethylenediaminetetraacetic acid (/sup 51/Cr-EDTA) following an intravenous injection in 28 anaesthetized rabbits. In some rabbits, the renal function was reduced by previous surgery. The insulin clearances ranged from 2.7 to 17 ml/minute. By a double-exponential analysis of the plasma disappearance curve, the total plasma clearance of /sup 51/Cr-EDTA was found to exceed the inulin clearance by 12%. By the simpler slope-intercept analysis requiring only two blood samples, this value was 32%. The renal clearance of /sup 51/Cr-EDTA was 97% of inulin clearance. In nephrectomized rabbits, plasma clearance of /sup 51/Cr-EDTA was 0.7 ml/minute. At all levels of renal function, measurement of the plasma clearance rate of /sup 51/Cr-EDTA by the single injection technique allowed a fairly reliable estimate of the glomerular filtration rate.

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

    NASA Technical Reports Server (NTRS)

    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.

  6. Bacterial clearance rate and a new differential hemocyte staining method to assess immunostimulant activity in shrimp.

    PubMed

    Sritunyalucksana, Kallaya; Gangnonngiw, Warachin; Archakunakorn, Somwit; Fegan, Daniel; Flegel, Timothy W

    2005-01-25

    New methods were developed to assess immunostimulant efficacy in the black tiger shrimp Penaeus monodon. Test shrimp were fed with 2 or 4 % yeast extract (YE)-coated feed while controls were fed non-coated feed. After 4 wk of feeding, individual shrimp were assessed for total hemocyte counts (THC), the number of granular hemocytes (GH) and rate of bacterial clearance. For hemocyte counts, formalin-fixed hemolymph was stained with 1.2 % Rose Bengal in 50 % ethanol for 20 min at room temperature. Some of this mixture was used for THC with a hemocytometer while some was smeared on a microscope slide and left to dry before counterstaining with hematoxylin for GH counts. By this technique, high quality smears were obtained for accurate differential counts. Bacterial clearance assays were used to assess the sum effect of humoral and cellular defense mechanisms. Vibrio harveyi was injected intramuscularly at 1 x 10(8) cells per shrimp and hemolymph was collected in anticoagulant at 0, 15, 30 and 60 min post-injection for quadruplicate drop counts (20 microl) on TCBS agar. Total hemocyte counts for shrimp fed with 4 % YE were significantly higher (p < 0.05) than those for shrimp fed with non-coated feed. The percentage of granular cells and the rates of bacterial clearance for the YE-fed shrimp were higher than those for shrimp fed the control diet. These 2 methods provide a simple and rapid comparison of shrimp groups for differences in anti-bacterial defense capacity. PMID:15759805

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

    SciTech Connect

    LaForce, F.M.; Boose, D.S.

    1988-02-01

    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.

  8. Iohexol plasma clearance, a simple and reliable method to measure renal function in conscious mice.

    PubMed

    Luis-Lima, Sergio; Rodríguez-Rodríguez, Ana Elena; Martín-Higueras, Cristina; Sierra-Ramos, Catalina; Carrara, Fabiola; Arnau, María Rosa; Alvarez de la Rosa, Diego; Salido, Eduardo; Gaspari, Flavio; Porrini, Esteban

    2016-09-01

    In mice, renal function evaluated by serum creatinine has limitations. Gold standard methods using radioactive markers are cumbersome. We aimed to develop the iohexol plasma clearance as a simple assessment of renal function in conscious mice. We used two groups of mice: testing and validation, formed by 16 animals (8 male and 8 female) each. Iohexol was injected intravenously into the tail vein (6.47 mg), and tail tip blood samples were collected at 1, 3, 7, 10, 15, 35, 55, and 75 min. Iohexol plasma clearances were calculated in two ways: (1) two-compartment model (CL2) using all time points and (2) one-compartment model (CL1) using only the last four points. In the testing group, CL1 overestimated the true clearance (CL2). Therefore, CL1 was recalculated applying a correction factor calculated as the ratio between CL2/CL1. The latter was considered as the simplified method. CL2 averaged 223.3 ± 64.3 μl/min and CL1 252.4 ± 76.4 μl/min, which lead to a CF of 0.89. Comparable results for CL2, CL1, and simplified method were observed in the validation group. Additionally, we demonstrated the capacity of the simplified method to quantitatively assess different degrees of renal function in three mouse models: hyperoxaluric-CKD (87.4 ± 28.3 μl/min), heminephrectomized (135-0 ± 50.5 μl/min), and obese (399.6 ± 112.1 μl/min) mice. We have developed a simple and reliable method to evaluate renal function in conscious mice under diverse clinical conditions. Moreover, the test can be repeated in the same animal, which makes the method useful to examine renal function changes over time. PMID:27315812

  9. The hydrogen gas clearance method for liver blood flow examination: inhalation or local application of hydrogen?

    PubMed

    Metzger, H P

    1989-01-01

    The combined method of hydrogen inhalation and local hydrogen production enable the determination of hepatic blood flow (HBF) and local hepatic blood flow (LHBF). LHBF was registered within a small superficial tissue volume of 0.5 mm in diameter by means of a multi-wire electrode having 200 microns producing and 100 microns measuring wires arranged within less than 300 microns distance between the measuring wires. The feeding current for hydrogen production was 1 microA, the potential less than 10 V. The clearance in response to inhalation was registered by means of the same measuring electrodes within the same tissue volume. Spontaneously breathing rats (Wistar-Frömter strain, 180-230 g bw, N = 19, ketamin-xylazine anesthesia, artificial respiration) showed the following flow values: HBF +/- SD = 0.50 +/- 0.26 ml/g.min, n = 48 registrations; LHBF +/- SD = 4.66 +/- 2.13 ml/g.min, n = 43. The validity of the combined method is demonstrated in the LHBF/HBF graph which summarizes the data of hemorrhagic and control animals, m = 0.1 and yo = 0.001. The correlation coefficient of r = 0.685 shows a reasonable correlation of the combined data despite the wide scattering of the individual values.

  10. Development of the Analysis Method for the Radioactivity Concentration Estimation of Soils for a Regulatory Clearance

    SciTech Connect

    Dae-Seok Hong; Jong-Sik Shon; Tae-Kuk Kim; Han-Seok Cho

    2006-07-01

    In this study, for the analysis of a radioactivity concentration of soil, a sampling and an analyzing method were developed. To create homogeneity of the contents for each drum, big particles such as pebbles, rocks and scraps of concrete were removed after pouring the soil into a tray. And then the soil in the tray was mixed thoroughly. A 10 X 10 grid was used to partition the soil into 100 sections. 2 liter of soil was sampled out of 30 randomly pre-selected sections. Only 1 liter of the soil out of 2 liters was used for the spectrometry analysis. The remaining 1 liter of soil was stored for a validation purpose. For a verification of the sampling process, 3 samples were taken from each drum and analyzed. 5 drums were used for the verification. And the results show that this sampling method has about a 9% sampling error. Also, the analysis results of the 865 drums of soil showed that the major nuclides in the soils were Co-60 and Cs-137 while a small amount of Mn-54, Fe-59, I-131, Cs-134 and Eu-152 were detected as {gamma}-emitters. About 73% of the soils had a total radioactivity concentration below 0.1 Bq/g, while the soils with more than 0.4 Bq/g of a radioactivity concentration were only 3%. Based on the guide for the regulatory clearance criteria recommended by the IAEA (International Atomic Energy Agency), about 73% of the soils can be regulatory cleared without any treatment. Also, the remaining soils can be regulatory cleared after a further storage. Only 3% of the soils are considered to be necessary for a decontamination treatment. The results of this study can be applied to the treatment of radioactive soils generated in a large amount during the decommissioning of a nuclear facility. (authors)

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

    DOEpatents

    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.

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

    DOEpatents

    Casada, D.A.; Haynes, H.D.; Moyers, J.C.; Stewart, B.K.

    1996-01-30

    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. 8 figs.

  13. Effect of exosome isolation methods on physicochemical properties of exosomes and clearance of exosomes from the blood circulation.

    PubMed

    Yamashita, Takuma; Takahashi, Yuki; Nishikawa, Makiya; Takakura, Yoshinobu

    2016-01-01

    Exosomes, which are expected to be delivery systems for biomolecules such as nucleic acids, are collected by several methods. However, the effect of exosome isolation methods on the characteristics of exosomes as drug carriers, such as recovery efficiency after sterile filtration and pharmacokinetics, has not been investigated despite the importance of these characteristics for the development of exosome-based delivery systems. In the present study, exosomes collected from murine melanoma B16-BL6 cells by several methods were compared with respect to dispersibility, recovery rate after filtering, and clearance from the blood circulation in mice. The exosomes were collected by three ultracentrifugation-based methods: simple ultracentrifugation/pelleting (pelleting method), ultracentrifugation with an iodixanol cushion (cushion method), and ultracentrifugation on an iodixanol density gradient (gradient method). The isolation methods had little effect on the particle number of exosomes. In contrast, transmission electron microscopy observation and size distribution measurement using tunable resistive pulse sensing indicated that the exosomes of the gradient method were more dispersed than the others. The exosomes were labeled with Gaussia luciferase and intravenously injected into mice. Clearance of injected exosomes from the blood circulation did not significantly change with isolation methods. When the exosomes were filtered using a 0.2-μm filter, the recovery rate was 82% for the exosomes of the gradient method, whereas it was less than 50% for the others. These results indicate that the exosome isolation method markedly affects the dispersibility and filtration efficiency of the exosomes. PMID:26545617

  14. Atrial natriuretic peptide increases microvascular blood flow and macromolecular escape during renin infusion in the hamster

    SciTech Connect

    Boric, M.P.; Albertini, R. )

    1990-02-01

    The effects of Atrial Natriuretic Peptide (ANP) on microvascular hemodynamics and macromolecular permselectivity were studied in the hamster cheek pouch under resting conditions and during intravenous renin infusion. Fluorescent intravital microscopy was used to observe arteriolar diameters and to detect escape of fluorescent dextran of 150 K-Daltons (FITC-Dx-150). Microvascular plasma flow was estimated by clearance of 51Cr-EDTA and net macromolecular transport by clearance of FITC-Dx-150. At rest, topical ANP (2-250 ng/ml) had no effect on arteriolar diameter, 51Cr-EDTA clearance, relative vascular conductance (RVC) or FITC-Dx-150 clearance. Infusion of renin (10 mU/Kg/Hr, iv) elevated systemic arterial pressure by 30% and reduced cheek pouch RVC by 26%. During renin infusion, topical ANP (50 ng/ml) produced transient arteriolar vasodilation, and increased 51Cr-EDTA clearance (+35%), RVC (+58%) and FITC-Dx-150 clearance (+54%), without affecting systemic pressure. ANP did not induce venular leakage sites under any condition, but changes in FITC-Dx-150 clearance were highly correlated with changes in 51Cr-EDTA clearance, suggesting that the larger macromolecular escape was due to increases in microvascular blood flow and capillary/post-capillary hydrostatic pressure.

  15. Is the new GFR equation using inulin clearance a more accurate method for Asian patients?

    PubMed

    Kim, Beom Seok; Lee, Yong Kyu; Choi, Hoon Young; Choi, Seung Ok; Shin, Sug Kyun; Ha, Sung Kyu; Lee, Kang Wook; Kim, Yang Wook; Kim, Yong Lim; Yasuda, Yoshinari; Imai, Enyu; Horio, Masaru; Tomino, Yasuhiko; Matsuo, Seiichi; Lee, Ho Yung

    2015-12-01

    Recently, a new glomerular filtration rate (GFR) equation for the Japanese population was proposed using measured inulin clearance. To expand its applicability to other Asian populations, we performed a comparative study in the Korean population. Inulin clearance was measured in 166 patients from seven participating medical centers in Korea. Patient's sera and urine were collected, and baseline clinical characteristics were measured to provide an estimated GFR (eGFR) by the Japanese GFR equation using inulin clearance (Japanese-GFR equation), the Modification of Diet in Renal Disease (MDRD) study equation, and the Chronic Kidney Disease - Epidemiology Collaboration (CKD-EPI) equation. We compared the results to determine which equation best estimated the measured GFR (mGFR). Accuracy (95% CI) within 30% of mGFR by the Japanese-GFR equation, the CKD-EPI equation and the MDRD study equation were 66 (58 - 72), 51 (43 - 58), and 55 (47 - 62)%, respectively. Bias (mGFR minus eGFR) were 3.4 ± 22.4, -12.0 ± 22.1, and -9.7 ± 23.8 mL/min/1.73 m2, respectively. The accuracy of the Japanese-GFR equation was significantly better than MDRD study equation in subjects with mGFR < 60 mL/min/1.73 m2 and in total subjects. The bias of the Japanese-GFR equation was significantly smaller compared with other two equations in total subjects. The Japanese-GFR equation has a higher accuracy with less bias than the other equations in estimating GFR in Korean populations. Further studies are required to determine if the current Japanese-GFR equation could represent the standard eGFR for other Asian populations.

  16. Validation of a microbiological method using Acholeplasma laidlawii for assessing performance of microporous membranes for mycoplasma clearance.

    PubMed

    Cronholm, Karen; Bates, Shawn; Nguyen, Nhung; Leahy, Anne; Blanchard, Mark; Lentine, Kerry Roche

    2009-01-01

    While no recognized industry standard currently exists for mycoplasma clearance testing of membrane filters, several methods have been used by membrane manufacturers and contract test laboratories. This validation exercise documents one approach to mycoplasma clearance testing and incorporates validation guidelines recognized in the biopharmaceutical industry today. The benefits of this method are (1) the consistent production of small monodisperse cells, 0.37 x 0.41 microm, at titers in excess of 1 x 10(9) CFU mL(-1) within 20-24 h of incubation; (2) the consistent detection of low levels of Acholeplasma laidlawii with an absence of false negative results; and (3) the ability to distinguish among membrane filters with different bubble points. The results of the validation exercise demonstrate that the equipment, materials, and test methods of the A. laidlawii filter challenge test are suitably understood and in a state of control. This method is appropriate to characterize the performance of membrane filters used in biopharmaceutical applications.

  17. Effect of size and lipid composition on the pharmacokinetics of intravitreal liposomes

    SciTech Connect

    Barza, M.; Stuart, M.; Szoka, F. Jr.

    1987-05-01

    We investigated the influence of size and lipid composition on the pharmacokinetic behavior of liposomes and their contents in the rabbit eye. Small and large unilamellar vesicles (SUV and LUV), prepared with and without cholesterol in the membrane, were injected intravitreally in rabbits. The vesicles were labelled with /sup 125/I and contained /sup 51/Cr-EDTA in the aqueous compartment. The mode of elimination of the vesicles from the vitreous humor is uncertain but may be via the anterior route; /sup 51/Cr-EDTA, like gentamicin, probably is eliminated by the anterior route. The rate of clearance of the lipid label appeared to be related to the size but not to the cholesterol content of the liposomes. Liposome-encapsulation prolonged the half-life of /sup 51/Cr-EDTA by up to 11-fold in the vitreous humor of normal eyes. The prolongation was greatest with cholesterol-containing vesicles, presumably because these are most stable, and was somewhat greater with large than with small vesicles. For SUV and LUV, the rate of elimination of /sup 51/Cr-EDTA from the normal eye was determined mainly by the rate of leakage from the liposomes, whereas for SUV-cholesterol and LUV-cholesterol, it was determined mainly by the rate of clearance of the liposomes themselves. Both /sup 51/Cr-EDTA and liposomes (/sup 125/I label) had a shorter half-life in infected than in normal eyes. Encapsulation of /sup 51/Cr-EDTA prolonged its half-life by up to sevenfold in infected eyes; the effect was greatest with cholesterol-containing vesicles. These results suggest that both the structure of the liposome and the state of the eye may markedly affect the pharmacokinetic behavior of intravitreal liposomes.

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

    PubMed

    Larsen, Poul S; Riisgård, Hans Ulrik

    2012-01-15

    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. PMID:23213362

  19. Building a 3D Virtual Liver: Methods for Simulating Blood Flow and Hepatic Clearance on 3D Structures.

    PubMed

    White, Diana; Coombe, Dennis; Rezania, Vahid; Tuszynski, Jack

    2016-01-01

    In this paper, we develop a spatio-temporal modeling approach to describe blood and drug flow, as well as drug uptake and elimination, on an approximation of the liver. Extending on previously developed computational approaches, we generate an approximation of a liver, which consists of a portal and hepatic vein vasculature structure, embedded in the surrounding liver tissue. The vasculature is generated via constrained constructive optimization, and then converted to a spatial grid of a selected grid size. Estimates for surrounding upscaled lobule tissue properties are then presented appropriate to the same grid size. Simulation of fluid flow and drug metabolism (hepatic clearance) are completed using discretized forms of the relevant convective-diffusive-reactive partial differential equations for these processes. This results in a single stage, uniformly consistent method to simulate equations for blood and drug flow, as well as drug metabolism, on a 3D structure representative of a liver. PMID:27649537

  20. Building a 3D Virtual Liver: Methods for Simulating Blood Flow and Hepatic Clearance on 3D Structures

    PubMed Central

    Rezania, Vahid; Tuszynski, Jack

    2016-01-01

    In this paper, we develop a spatio-temporal modeling approach to describe blood and drug flow, as well as drug uptake and elimination, on an approximation of the liver. Extending on previously developed computational approaches, we generate an approximation of a liver, which consists of a portal and hepatic vein vasculature structure, embedded in the surrounding liver tissue. The vasculature is generated via constrained constructive optimization, and then converted to a spatial grid of a selected grid size. Estimates for surrounding upscaled lobule tissue properties are then presented appropriate to the same grid size. Simulation of fluid flow and drug metabolism (hepatic clearance) are completed using discretized forms of the relevant convective-diffusive-reactive partial differential equations for these processes. This results in a single stage, uniformly consistent method to simulate equations for blood and drug flow, as well as drug metabolism, on a 3D structure representative of a liver. PMID:27649537

  1. Ultrasound Based Method and Apparatus for Stone Detection and to Facilitate Clearance Thereof

    NASA Technical Reports Server (NTRS)

    Bailey, Michael (Inventor); Kucewicz, John (Inventor); Lu, Wei (Inventor); Sapozhnikov, Oleg (Inventor); Illian, Paul (Inventor); Shah, Anup (Inventor); Dunmire, Barbrina (Inventor); Owen, Neil (Inventor); Cunitz, Bryan (Inventor); Kaczkowski, Peter (Inventor)

    2015-01-01

    Described herein are methods and apparatus for detecting stones by ultrasound, in which the ultrasound reflections from a stone are preferentially selected and accentuated relative to the ultrasound reflections from blood or tissue. Also described herein are methods and apparatus for applying pushing ultrasound to in vivo stones or other objects, to facilitate the removal of such in vivo objects.

  2. Identifying minefields and verifying clearance: adapting statistical methods for UXO target detection

    NASA Astrophysics Data System (ADS)

    Gilbert, Richard O.; O'Brien, Robert F.; Wilson, John E.; Pulsipher, Brent A.; McKinstry, Craig A.

    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.

  3. Method and apparatus for measuring engine compression ratio, clearance volume and related cylinder parameters

    SciTech Connect

    Haddox, M.L.

    1986-01-06

    A method is described of quantifying leakage from a cylinder of an internal combustion engine having a piston disposed to reciprocate within the cylinder and a crankshaft rotatably coupled to the piston, the method comprising the steps of: (a) monitoring rotation of the crankshaft, (b) monitoring pressure within the cylinder while the crankshaft is rotating and the piston is reciprocating within the cylinder, (c) identifying displacement volumes of the piston within the cylinder as a function of rotation of the crankshaft, and (d) quantifying leakage from the cylinder as a function of monitored pressure and identified displacement volumes.

  4. Aerodynamic investigation of an air-cooled axial-flow turbine. Part 2: Rotor blade tip-clearance effects on overall turbine performance and internal gas flow conditions: Experimental results and prediction methods

    NASA Technical Reports Server (NTRS)

    Yamamoto, A.; Takahara, K.; Nouse, H.; Mimura, F.; Inoue, S.; Usui, H.

    1977-01-01

    Total turbine blade performance was investigated while changing the blade tip clearance in three ways. The internal flow at the moving blade outlet point was measured. Experimental results were compared with various theoretical methods. Increased blade clearance leads to decreased turbine efficiency.

  5. A Real-time Method to Evaluate the Nasal Deposition and Clearance of Acetone in the Human Volunteer

    SciTech Connect

    Thrall, Karla D. ); Schwartz, Ronald E.; Weitz, Karl K. ); Soelberg, Jolen J. ); Foureman, Gary L.; Prah, James D.; Timchalk, Charles

    2003-05-01

    Nasal dosimetry models have become increasingly quantitative as insights into tissue deposition/clearance and computational fluid dynamics have become available. Validation of these models requires sufficient experimental data. However, investigations into respiratory deposition, particularly in human volunteers, have been historically limited due to methodological limitations. To overcome this, a method for evaluating the nasal wash-in, wash-out phenomena of a highly water-soluble compound in human volunteers was developed and characterized. This methodology was assessed using controlled human inhalation exposures to uniformly labeled 13C-acetone at approximately 1 ppm concentration for 30 minutes under different breathing maneuvers (inhale nose/exhale nose; inhale nose/exhale mouth; inhale mouth/exhale nose). A small-diameter air-sampling probe inserted in the nasopharyngeal cavity of the volunteer was connected directly to an ion-trap mass spectrometer capable of sampling every 0.8 sec. A second ion-trap mass spectrometer simultaneously sampled from the volunteer?s exhaled breath stream via a breath-inlet device interface. Together, the two mass spectrometers provided real-time appraisal of the 13C-acetone concentrations in the nasopharyngeal region and in the exhaled breath stream before, during, and after the different breathing maneuvers. The breathing cycle (depth and frequency) and heart rate were concurrently monitored throughout the exposure using a heart rate monitor and a human plethysmograph to differentiate inhalation and exhalation. Graphical overlay of the plethysmography results with the mass spectrometer measurements show clear quantifiable differences in 13C-acetone levels at the nasal probe as a function of breathing maneuvers. Breath-by-breath analysis of 13C-acetone concentrations indicate that between 40-75% of the compound is absorbed upon inhalation and nearly all of that absorbed released back into the breath stream during exhalation.

  6. Intelligent Engine Systems: HPT Clearance Control

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The Advanced Thermally Actuated Clearance Control System underwent several studies. Improved flow path isolation quantified what can be gained by making the HPT case nearly adiabatic. The best method of heat transfer was established, and finally two different borrowed air cooling circuits were evaluated to be used for the HPT Active Clearance Control System.

  7. In vivo clearance of ethoxycoumarin and its prediction from In vitro systems. Use Of drug depletion and metabolite formation methods in hepatic microsomes and isolated hepatocytes.

    PubMed

    Carlile, D J; Stevens, A J; Ashforth, E I; Waghela, D; Houston, J B

    1998-03-01

    The pharmacokinetics of ethoxycoumarin have been characterized using steady-state plasma concentrations achieved after administration of this compound, at a series of infusion rates, into the hepatic portal vein of rats. The clearance of ethoxycoumarin could be described by a one-site Michaelis-Menten kinetic model with Vmax and unbound KM values of 495 nmol/min/standard rat weight (SRW) and 3.6 microM, respectively, and an intrinsic clearance (CLint, Vmax/KM ratio) of 137 ml/min/SRW (where SRW is 250 g). Urinary excretion experiments, using both ethoxycoumarin and hydroxycoumarin, demonstrated that 7-hydroxycoumarin, the metabolite frequently measured in in vitro studies, accounted for 26% of the metabolism of ethoxycoumarin. In vitro studies with hepatic microsomes and isolated hepatocytes were undertaken to characterize the kinetics of both hydroxycoumarin formation and ethoxycoumarin depletion and to compare the utility of these methods for predicting in vivo clearance. In both in vitro systems, hydroxycoumarin formation displayed biphasic kinetics, with a high-affinity/low-capacity component (with Vmax, KM, and CL1 terms) and a low-affinity/high-capacity component (with a CL2 term) that was not saturated over the substrate concentration range studied (0.5-100 microM). The use of scaling factors to relate in vitro and in vivo data showed that, although microsomal and hepatocyte Vmax values were comparable (26 and 17 nmol/min/SRW, respectively), both were substantially lower than the in vivo value. However, scaling of the in vitro CLint values, by taking into account the fraction of ethoxycoumarin metabolized to hydroxycoumarin, yielded in vivo predictions of 127 and 122 ml/min/SRW (representing 93 and 89% of the observed CLint value) for microsomes and hepatocytes, respectively. The depletion of ethoxycoumarin (1-1.5 microM) with time in both microsomes and hepatocytes displayed a monoexponential decline and predicted in vivo CLint values of 53 and 117 ml

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

    PubMed

    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

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

    PubMed

    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.

  10. Hemodialysis clearance of theophylline.

    PubMed

    Slaughter, R L; Green, L; Kohli, R

    1982-01-01

    The serum hemodialysis clearance of theophylline was determined in 4 patients compared to systemic serum clearance off dialysis in 3 patients. The serum extraction ratio values obtained were compared to those of urea. Hemodialysis clearance of theophylline averaged 84.3 +/- 11.6 ml/min (mean +/- SD), and extraction ratios obtained were found to be a fairly consistent fraction of the urea extraction ratio (0.72 +/- 0.08). Hemodialysis clearance increased total body clearance (ClTB) off dialysis by 130%, 387%, and 176% in the patients who had their theophylline serum clearance estimated off dialysis. Difference in reported hemodialysis clearance are probably related to the type of dialyser used. Studies utilizing hollow fiber systems (the present study) consistently yielded higher theophylline dialysis clearance values than those using coil systems (84.3% to 88.1 ml/min versus 32 to 39.4 ml/min). Patients receiving theophylline on hemodialysis should be closely monitored for bronchospasm during and after the hemodialysis procedure. Measurement of serum concentrations should be employed to facilitate dosage increases during hemodialysis.

  11. Turbomachinery Clearance Control

    NASA Technical Reports Server (NTRS)

    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.

  12. Plasma Creatinine Clearance in the Dog

    ERIC Educational Resources Information Center

    Frazier, Loy W.

    1977-01-01

    Lists materials and methods for an experiment that demonstrates the concept of glomerular filtration rate (GFR) using anesthesized dogs. In the dog, GFR is equivalent to the renal plasma clearance of exogenous creatinine. (CS)

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

    NASA Astrophysics Data System (ADS)

    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.

  14. Evaluation of an Active Clearance Control System Concept

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M.; Lattime, Scott B.; Taylor, Shawn; DeCastro, Jonathan A.; Oswald, Jay; Melcher, Kevin J.

    2005-01-01

    Reducing blade tip clearances through active tip clearance control in the high pressure turbine can lead to significant reductions in emissions and specific fuel consumption as well as dramatic improvements in operating efficiency and increased service life. Current engines employ scheduled cooling of the outer case flanges to reduce high pressure turbine tip clearances during cruise conditions. These systems have relatively slow response and do not use clearance measurement, thereby forcing cold build clearances to set the minimum clearances at extreme operating conditions (e.g., takeoff, reburst) and not allowing cruise clearances to be minimized due to the possibility of throttle transients (e.g., step change in altitude). In an effort to improve upon current thermal methods, a first generation mechanically-actuated active clearance control (ACC) system has been designed and fabricated. The system utilizes independent actuators, a segmented shroud structure, and clearance measurement feedback to provide fast and precise active clearance control throughout engine operation. Ambient temperature performance tests of this first generation ACC system assessed individual seal component leakage rates and both static and dynamic overall system leakage rates. The ability of the nine electric stepper motors to control the position of the seal carriers in both open- and closed-loop control modes for single and multiple cycles was investigated. The ability of the system to follow simulated engine clearance transients in closed-loop mode showed the system was able to track clearances to within a tight tolerance ( 0.001 in. error).

  15. Evaluation of an Active Clearance Control System Concept

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M.; Lattime, Scott B.; DeCastro, Jonathan A.; Oswald, Jay; Melcher, Kevin J.

    2005-01-01

    Reducing blade tip clearances through active tip clearance control in the high pressure turbine can lead to significant reductions in emissions and specific fuel consumption as well as dramatic improvements in operating efficiency and increased service life. Current engines employ scheduled cooling of the outer case flanges to reduce high pressure turbine tip clearances during cruise conditions. These systems have relatively slow response and do not use clearance measurement, thereby forcing cold build clearances to set the minimum clearances at extreme operating conditions (e.g., takeoff, reburst) and not allowing cruise clearances to be minimized due to the possibility of throttle transients (e.g., step change in altitude). In an effort to improve upon current thermal methods, a first generation mechanically-actuated active clearance control (ACC) system has been designed and fabricated. The system utilizes independent actuators, a segmented shroud structure, and clearance measurement feedback to provide fast and precise active clearance control throughout engine operation. Ambient temperature performance tests of this first generation ACC system assessed individual seal component leakage rates and both static and dynamic overall system leakage rates. The ability of the nine electric stepper motors to control the position of the seal carriers in both open- and closed-loop control modes for single and multiple cycles was investigated. The ability of the system to follow simulated engine clearance transients in closed-loop mode showed the system was able to track clearances to within a tight tolerance (0.001 in. error).

  16. Adaptation of a single injection clearance method to physiological and pathophysiological facts. A review of data obtained in infancy and childhood.

    PubMed

    Wassmer, M; Schafroth, M; Bretscher, D; Schneider, A; Oetliker, O

    1977-07-01

    A retrospective analysis of 395 51Chromiumethylenediaminotetraacetate single injection clearances performed in infants and children is presented. In 61% of infants and 30% of the children the clearance values were calculated on the basis of a plasma disappearance half time of the reference substance, which was longer than the standard study, i.e. on the basis of extrapolated data. Plasma creatinine and urea levels were found to be appropriate indicators for predicting the plasma disappearance half time of the marker substance. 14 additional patients were studied prospectively with a duration of the study predicted by means of the plasma creatinine and urea levels. In these patients, separate determinations of the clearances using either the data obtained during the standard time of procedure only, or the data of the entire study, clearly demonstrated that the clearances obtained by means of the standard procedure overestimated glomerular filtration rate. The analysis of the data in infants show that the plasma urea level is a reasonably good indicator for predicting the time schedule of the study whereas plasma creatinine should not be used. Additionally the retrospective data indicate that a prolongation of the study should be recommended in all infants. This study demonstrates the necessity and offers means of adapting the time schedule of isotope single injection clearances to physiological and pathophysiological facts.

  17. Development and implementation of a stereoselective normal-phase liquid chromatography-tandem mass spectrometry method for the determination of intrinsic metabolic clearance in human liver microsomes.

    PubMed

    Zhang, Yingru; Caporuscio, Christian; Dai, Jun; Witkusa, Michael; Rose, Anne; Santella, Joseph; D'Arienzo, Celia; Wang-Iverson, David B; Tymiak, Adrienne A

    2008-11-01

    with R2 > or =0.997. The precision of the analysis was <5% R.S.D. at or above the nominal concentration of 80 ng/mL, and <20% R.S.D. at 8 ng/mL. The mean bias was less than 15%. Extraction recovery and acceptable matrix interference were demonstrated using one isomer and the ketone, and better than 75% recovery and less than 25% ion suppression or interference were found. The method was successfully implemented for an in vitro intrinsic metabolic clearance study. PMID:18722827

  18. Site clearance working group

    SciTech Connect

    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.

  19. 24 CFR 35.1340 - Clearance.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Methods and Standards for Lead-Paint... abatement of lead-based paint or lead-based paint hazards shall be performed in accordance with 40 CFR 745... the steps set forth at 40 CFR 745.227(e)(8). If clearance is being performed after lead-based...

  20. 24 CFR 35.1340 - Clearance.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Methods and Standards for Lead-Paint... abatement of lead-based paint or lead-based paint hazards shall be performed in accordance with 40 CFR 745... the steps set forth at 40 CFR 745.227(e)(8). If clearance is being performed after lead-based...

  1. 24 CFR 35.1340 - Clearance.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Methods and Standards for Lead-Paint... abatement of lead-based paint or lead-based paint hazards shall be performed in accordance with 40 CFR 745... the steps set forth at 40 CFR 745.227(e)(8). If clearance is being performed after lead-based...

  2. 24 CFR 35.1340 - Clearance.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Methods and Standards for Lead-Paint... abatement of lead-based paint or lead-based paint hazards shall be performed in accordance with 40 CFR 745... the steps set forth at 40 CFR 745.227(e)(8). If clearance is being performed after lead-based...

  3. Predicting clearance in humans from in vitro data.

    PubMed

    Obach, R Scott

    2011-01-01

    The use of in vitro metabolism in scaling to predict human clearance of new chemical entities has become a commonplace activity in the research and development of new drugs. The measurement of in vitro lability in human liver microsomes, a rich source of drug metabolizing cytochrome P450 enzymes, has become a high throughput screen in many research organizations which is a testament to its usefulness in drug design. In this chapter, the methods used to scale in vitro clearance data to predict in vivo clearance are described. Importantly, the numerous assumptions that are required in order to use in vitro data in this manner are laid out. These include assumptions regarding the scaling process as well as technical aspects of the generation of the in vitro data. Finally, some other drug clearance processes that have been emerging as important are described with regard to ongoing research efforts to develop clearance prediction methods.

  4. Some Practical Payments Clearance Algorithms

    NASA Astrophysics Data System (ADS)

    Kumlander, Deniss

    The globalisation of corporations' operations has produced a huge volume of inter-company invoices. Optimisation of those known as payment clearance can produce a significant saving in costs associated with those transfers and handling. The paper revises some common and so practical approaches to the payment clearance problem and proposes some novel algorithms based on graphs theory and heuristic totals' distribution.

  5. 32 CFR 644.517 - Clearance of Army lands.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Clearance, the following information will be furnished to the DE upon completion of the neutralization: (a) Records of the neutralization work performed, including statement of methods employed. (b) List...

  6. 32 CFR 644.517 - Clearance of Army lands.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Clearance, the following information will be furnished to the DE upon completion of the neutralization: (a) Records of the neutralization work performed, including statement of methods employed. (b) List...

  7. 32 CFR 644.517 - Clearance of Army lands.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Clearance, the following information will be furnished to the DE upon completion of the neutralization: (a) Records of the neutralization work performed, including statement of methods employed. (b) List...

  8. [Ratio of amylase clearance and creatinine clearance in the diagnosis of acute pancreatitis].

    PubMed

    Haffter, D; Reichlin, B; Gyr, K

    1981-05-30

    In 21 healthy volunteers the ratio of amylase clearance and creatinine clearance (Cam/Ccr) was determined in urine collected at admission, after a 1-hour collection period and after a 2-hour collection period. The normal values were 1.8 +/- 1.6%, 1.9 +/- 2% and 2.0 +/- 1.7% respectively. They were comparable with those published by others. The reproducibility of the method was acceptable (r = 0.62). When compared with serum amylase determinations, Cam/Ccr showed neither better sensitivity in 19 patients suffering an acute episode of proven pancreatitis, nor better specificity in 19 patients with acute abdomen but no evidence of pancreatitis.

  9. Dual clearance squeeze film damper

    NASA Technical Reports Server (NTRS)

    Fleming, D. P. (Inventor)

    1985-01-01

    A dual clearance hydrodynamic liquid squeeze film damper for a gas turbine engine is described. Under normal operating conditions, the device functions as a conventional squeeze film damper, using only one of its oil films. When an unbalance reaches abusive levels, as may occur with a blade loss or foreign object damage, a second, larger clearance film becomes active, controlling vibration amplitudes in a near optimum manner until the engine can be safely shut down and repaired.

  10. Instrument for Measuring Engine Clearance Volumes

    NASA Technical Reports Server (NTRS)

    Sparrow, S W

    1920-01-01

    With the advent of the V type engine, a new method to measure the clearance volume in cylinders was needed. It was suggested that this measurement could be made by a process which consisted essentially of simultaneously changing both a known and unknown volume of gas by a known amount and then calculating the magnitude of the unknown from the resulting difference in pressure between the two. An instrument based on this design is described.

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

    PubMed

    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.

  12. 14 CFR 23.925 - Propeller clearance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller clearance. 23.925 Section 23.925... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant General § 23.925 Propeller clearance. Unless smaller clearances are substantiated, propeller clearances, with the airplane at the...

  13. 14 CFR 25.925 - Propeller clearance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller clearance. 25.925 Section 25.925... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.925 Propeller clearance. Unless smaller clearances are substantiated, propeller clearances with the airplane at maximum weight, with the most...

  14. 14 CFR 23.925 - Propeller clearance.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Propeller clearance. 23.925 Section 23.925... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant General § 23.925 Propeller clearance. Unless smaller clearances are substantiated, propeller clearances, with the airplane at the...

  15. 14 CFR 25.925 - Propeller clearance.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Propeller clearance. 25.925 Section 25.925... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.925 Propeller clearance. Unless smaller clearances are substantiated, propeller clearances with the airplane at maximum weight, with the most...

  16. 14 CFR 25.925 - Propeller clearance.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Propeller clearance. 25.925 Section 25.925... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.925 Propeller clearance. Unless smaller clearances are substantiated, propeller clearances with the airplane at maximum weight, with the most...

  17. 14 CFR 23.925 - Propeller clearance.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Propeller clearance. 23.925 Section 23.925... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant General § 23.925 Propeller clearance. Unless smaller clearances are substantiated, propeller clearances, with the airplane at the...

  18. 14 CFR 23.925 - Propeller clearance.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Propeller clearance. 23.925 Section 23.925... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant General § 23.925 Propeller clearance. Unless smaller clearances are substantiated, propeller clearances, with the airplane at the...

  19. 14 CFR 25.925 - Propeller clearance.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Propeller clearance. 25.925 Section 25.925... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.925 Propeller clearance. Unless smaller clearances are substantiated, propeller clearances with the airplane at maximum weight, with the most...

  20. 14 CFR 25.925 - Propeller clearance.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Propeller clearance. 25.925 Section 25.925... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.925 Propeller clearance. Unless smaller clearances are substantiated, propeller clearances with the airplane at maximum weight, with the most...

  1. 14 CFR 23.925 - Propeller clearance.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Propeller clearance. 23.925 Section 23.925... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant General § 23.925 Propeller clearance. Unless smaller clearances are substantiated, propeller clearances, with the airplane at the...

  2. Gas turbine engine active clearance control

    NASA Technical Reports Server (NTRS)

    Deveau, Paul J. (Inventor); Greenberg, Paul B. (Inventor); Paolillo, Roger E. (Inventor)

    1985-01-01

    Method for controlling the clearance between rotating and stationary components of a gas turbine engine are disclosed. Techniques for achieving close correspondence between the radial position of rotor blade tips and the circumscribing outer air seals are disclosed. In one embodiment turbine case temperature modifying air is provided in flow rate, pressure and temperature varied as a function of engine operating condition. The modifying air is scheduled from a modulating and mixing valve supplied with dual source compressor air. One source supplies relatively low pressure, low temperature air and the other source supplies relatively high pressure, high temperature air. After the air has been used for the active clearance control (cooling the high pressure turbine case) it is then used for cooling the structure that supports the outer air seal and other high pressure turbine component parts.

  3. Mechanisms of the fetomaternal transfer of Na+ across the dually perfused placenta of the rat.

    PubMed

    Stulc, J; Stulcová, B; Sibley, C P

    1995-03-01

    In order to investigate mechanisms of fetal-maternal (F-M) transfer of Na+, clearance of 22Na+ and 51Cr-EDTA was measured simultaneously across the dually perfused placenta of the rat. In eight experiments clearance was measured successively in the F-M (Kfm) and in the maternal-fetal (M-F; Kmf) directions. Clearance of 22Na+ in the two directions was approximately equal (Kmf = 11.6 +/- 2.0 microliters/min; Kfm = 11.1 +/- 1.7 microliters/min: mean +/- s.d.) while Kfm of 51Cr-EDTA (4.4 +/- 0.7 microliters/min) was nearly double Kmf (2.4 +/- 0.8 microliters/min) for this tracer. Even greater asymmetry in the transfer of 51Cr-EDTA was found when measured across intact (non-perfused) placenta. It is suggested that this asymmetry is caused by volume flow in the F-M direction. In other experiments transfer was measured in the F-M direction only. Ouabain (0.1 mM) on the maternal side and reduced concentration of Na+ (25 mM) on the fetal side had no effect on the F-M transfer of the tracers. Reducing the temperature of the preparation by 5 degrees C significantly decreased transfer of 22Na+. The transfer of 22Na was inversely related to the concentration of K+ on the fetal side. These observations suggest that the F-M transfer of Na+ has three components: diffusion through paracellular routes; convective flow by filtration through wide placental pores, and transcellular transport by a mechanism which is uncertain at present.

  4. Automation for "Direct-to" Clearances in Air-Traffic Control

    NASA Technical Reports Server (NTRS)

    Erzberger, Heinz; McNally, David

    2006-01-01

    A method of automation, and a system of computer hardware and software to implement the method, have been invented to assist en-route air-traffic controllers in the issuance of clearances to fly directly to specified waypoints or navigation fixes along straight paths that deviate from previously filed flight plans. Such clearances, called "direct-to" clearances, have been in use since before the invention of this method and system.

  5. Influence of volume expansion on NaC1 reabsorption in the diluting segments of the nephron: a study using clearance methods.

    PubMed

    Danovitch, G M; Bricker, N S

    1976-09-01

    Whether volume expansion influences NaC1 reabsorption by the diluting segment of the nephron remains a matter of controversy. In the present studies this question has been examined in normal unanesthetized dogs, undergoing maximal water diuresis. Free water clearance (CH2O/GFR) has been used as the index of NaC1 reabsorption in the diluting segment. Three expressions have been employed for "distal delivery" of NaC1: a) V/GFR, designated as the "volume term"; b) (CNa/GFR + CH2O/GFR), the "sodium term;" and c) (CC1/GFR + CH2O/GFR), the "chloride term". The validity of these terms is discussed. Three techniques were used to increase distal delivery: 1) the administration of acetazolamide to dogs in which extracellular fluid (ECF) volume was not expanded (grop 1); 2) "moderate" volume expansion (group 2); and 3) "marked" volume expansion (group 3). CH2O/GFR increased progressively with rising values for "distal delivery" regardless of which term was used to calculate the latter. With all three delivery terms, differences in distal NaC1 reabsorption emerged between the two volume-expanded groups, though only with the "chloride" term did substantial differences also emerge between the nonexpanded group 1 dogs and both volume-expanded groups. In group 1, values for CH2O/GFR increased in close to a linear fashion up to distal delivery values equal to 24% of the volume of glomerular filtrate. However, at high rates of distal delivery the rate of rise of CH2O/GFR was less in group 2 than in group 1 and the depression of values was even greater in group 3. Within the limits of the techniques used, the data suggest that volume expansion inhibits fractional NaC1 reabsorption in the diluting segment of the nephron in a dose-related fashion. The "chloride" term was found to be superior to the "volume" and "sodium" terms in revealing these changes.

  6. Test Rig for Evaluating Active Turbine Blade Tip Clearance Control Concepts

    NASA Technical Reports Server (NTRS)

    Lattime, Scott B.; Steinetz, Bruce M.; Robbie, Malcolm G.

    2003-01-01

    Improved blade tip sealing in the high pressure compressor and high pressure turbine can provide dramatic improvements in specific fuel consumption, time-on-wing, compressor stall margin and engine efficiency as well as increased payload and mission range capabilities of both military and commercial gas turbine engines. The preliminary design of a mechanically actuated active clearance control (ACC) system for turbine blade tip clearance management is presented along with the design of a bench top test rig in which the system is to be evaluated. The ACC system utilizes mechanically actuated seal carrier segments and clearance measurement feedback to provide fast and precise active clearance control throughout engine operation. The purpose of this active clearance control system is to improve upon current case cooling methods. These systems have relatively slow response and do not use clearance measurement, thereby forcing cold build clearances to set the minimum clearances at extreme operating conditions (e.g., takeoff, re-burst) and not allowing cruise clearances to be minimized due to the possibility of throttle transients (e.g., step change in altitude). The active turbine blade tip clearance control system design presented herein will be evaluated to ensure that proper response and positional accuracy is achievable under simulated high-pressure turbine conditions. The test rig will simulate proper seal carrier pressure and temperature loading as well as the magnitudes and rates of blade tip clearance changes of an actual gas turbine engine. The results of these evaluations will be presented in future works.

  7. Inherited Disorders of Bilirubin Clearance

    PubMed Central

    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

  8. Inherited disorders of bilirubin clearance.

    PubMed

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

    2016-03-01

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

  9. Lithium clearance in mineralocorticoid escape in humans

    SciTech Connect

    Boer, W.H.; Koomans, H.A.; Mees, E.J.D.

    1987-03-01

    Lithium clearance (C/sub Li/) has been advanced as an indicator of Na delivery from the proximal tubules. The authors studied C/sub Li/ in eight healthy males before and after mineralocorticoid escape, a maneuver that may induce suppression of fractional proximal Na reabsorption (FPR/sub Na/). FPR/sub Na/ was also estimated from changes in maximal free water clearance (C/sub H/sub 2/O/). Plasma volume was measured as the /sup 131/I-labeled albumin distribution space. Extracellular fluid volume was estimated as the /sup 82/Br vector distribution volume. According to the latter method, FPR/sub Na/ dropped whereas inulin clearance rose. The changes in C/sub Li/ were surprisingly large. If lithium is a valid marker of Na handling in the proximal tubule in humans, this change would imply a fall in FPR/sub Na/, suggesting a much larger shift in tubular Na reabsorption in escape than hitherto suspected. In addition, it would suggest that the inevitable back diffusion of a part of the solute-free water in the distal nephron, and thus overestimation of FPR/sub Na/ by the C/sub H/sub 2/O/ method, increases importantly during escape. Alternately, lithium may not be a good marker of proximal tubular Na handling. For instance, both lithium reabsorption and escape may take place beyond the proximal tubule, or lithium may be excreted in the distal nephron in certain conditions. Present methods do not permit further analysis of these options in the human model.

  10. 22 CFR 16.6 - Security clearances.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Security clearances. 16.6 Section 16.6 Foreign Relations DEPARTMENT OF STATE PERSONNEL FOREIGN SERVICE GRIEVANCE SYSTEM § 16.6 Security clearances. The agencies shall use their best endeavors to expedite security clearances whenever necessary to ensure a...

  11. 30 CFR 18.24 - Electrical clearances.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electrical clearances. 18.24 Section 18.24... APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design Requirements § 18.24 Electrical clearances. Minimum clearances between uninsulated electrical...

  12. 30 CFR 18.24 - Electrical clearances.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Electrical clearances. 18.24 Section 18.24... APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design Requirements § 18.24 Electrical clearances. Minimum clearances between uninsulated electrical...

  13. 30 CFR 18.24 - Electrical clearances.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Electrical clearances. 18.24 Section 18.24... APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design Requirements § 18.24 Electrical clearances. Minimum clearances between uninsulated electrical...

  14. 30 CFR 18.24 - Electrical clearances.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Electrical clearances. 18.24 Section 18.24... APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design Requirements § 18.24 Electrical clearances. Minimum clearances between uninsulated electrical...

  15. 30 CFR 18.24 - Electrical clearances.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Electrical clearances. 18.24 Section 18.24... APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design Requirements § 18.24 Electrical clearances. Minimum clearances between uninsulated electrical...

  16. 22 CFR 16.6 - Security clearances.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Security clearances. 16.6 Section 16.6 Foreign Relations DEPARTMENT OF STATE PERSONNEL FOREIGN SERVICE GRIEVANCE SYSTEM § 16.6 Security clearances. The agencies shall use their best endeavors to expedite security clearances whenever necessary to ensure a...

  17. 22 CFR 16.6 - Security clearances.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Security clearances. 16.6 Section 16.6 Foreign Relations DEPARTMENT OF STATE PERSONNEL FOREIGN SERVICE GRIEVANCE SYSTEM § 16.6 Security clearances. The agencies shall use their best endeavors to expedite security clearances whenever necessary to ensure a...

  18. 22 CFR 16.6 - Security clearances.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Security clearances. 16.6 Section 16.6 Foreign Relations DEPARTMENT OF STATE PERSONNEL FOREIGN SERVICE GRIEVANCE SYSTEM § 16.6 Security clearances. The agencies shall use their best endeavors to expedite security clearances whenever necessary to ensure a...

  19. A comparison of GFR by modified gates method with measured creatinine clearance rate (CCR) & MDRD formula based estimation in type 2 diabetic subjects with nephropathy.

    PubMed

    Haque, M F; Iqbal, M M; Ahmed, Z; Sultan, T; Rahman, M; Quddus, S; Rahman, M Q; Ahmed, N N

    2013-10-01

    Accurate estimation of the glomerular filtration rate (GFR) is essential for the evaluation of patient with chronic kidney disease (CKD). The present study was a comparison between modified gates GFR with laboratory measured CCR & MDRD formula based estimated GFR method. Pre-diagnosed 180 diabetic nephropathy patients were selected. All the time of evaluation the blood glucose of the patients were controlled and serum creatinine was stable. Then CCR was done and GFR was estimated by Modified Gates method & MDRD method. All the patients were categorized in 5 stages of CKD. They were matched for age, BMI, blood pressure, duration of diabetes, the blood sugar and HbA1C levels. The Gates GFR in stage-2 (70±13) & stage-3 (48±12) was closer with MDRD in stage-2 (77±8) and stage 3 (43±7). The CCR is closer in stage-1 (110±52) & stage-4 (30±10) with MDRD in stage-1 (112±13) and stage-4 (21±4). Association study showed MDRD GFR had highest correlation with Gates GFR (r=0.86; p<0.05). The estimation of glomerular filtration rate (GFR) in different methods varied significantly between each other at different stages of chronic kidney disease (CKD) in type 2 diabetic nephropathy subjects.

  20. In vitro-in vivo Quantitative Extrapolation of Hepatic Metabolism Data for Fish: A Review of Methods and Strategies for Incorporating Intrinsic Clearance Estimates into Chemical Kinetic Models

    EPA Science Inventory

    The approaches described in this paper will substantially improve risk assessments for compounds that undergo biotransformation. The purpose of this report is to review methods used by mammalian researchers to perform in vitro-in vivo metabolism extrapolations, discuss how these ...

  1. Apoptotic Cell Clearance in Development.

    PubMed

    Shklover, Jeny; Levy-Adam, Flonia; Kurant, Estee

    2015-01-01

    Programmed cell death and its specific form apoptosis play an important role during development of multicellular organisms. They are crucial for morphogenesis and organ sculpting as well as for adjusting cell number in different systems. Removal of apoptotic cells is the last critical step of apoptosis. Apoptotic cells are properly and efficiently recognized and eliminated through phagocytosis, which is performed by professional and nonprofessional phagocytes. Phagocytosis of apoptotic cells or apoptotic cell clearance is a dynamic multistep process, involving interactions between phagocytic receptors and ligands on apoptotic cells, which are highly conserved in evolution. However, this process is extremely redundant in mammals, containing multiple factors playing similar roles in the process. Using model organisms such as Caenorhabditis elegans, Drosophila melanogaster, zebrafish, and mouse permits addressing fundamental questions in developmental cell clearance by a comprehensive approach including powerful genetics and cell biological tools enriched by live imaging. Recent studies in model organisms have enhanced significantly our understanding of the molecular and cellular basis of apoptotic cell clearance during development. Here, we review the current knowledge and illuminate the great potential of the research performed in genetic models, which opens new directions in developmental biology.

  2. Fiber-optic laser Doppler turbine tip clearance probe.

    PubMed

    Büttner, Lars; Pfister, Thorsten; Czarske, Jürgen

    2006-05-01

    A laser Doppler based method for in situ single blade tip clearance measurements of turbomachines with high precision is presented for what we believe is the first time. The sensor is based on two superposed fanlike interference fringe systems generated by two laser wavelengths from a fiber-coupled, passive, and therefore compact measurement head employing diffractive optics. Tip clearance measurements at a transonic centrifugal compressor performed during operation at 50,000 rpm (833 Hz, 586 m/s tip speed) are reported. At these speeds the measured uncertainty of the tip position was less than 20 microm, a factor of 2 more accurate than that of capacitive probes. The sensor offers great potential for in situ and online high-precision tip clearance measurements of metallic and nonmetallic turbine blades. PMID:16642064

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

    PubMed

    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.

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

    PubMed

    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

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

    SciTech Connect

    von Ritter, C.

    1988-01-01

    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 {sup 51}Cr-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-CH{sub 2}Cl(MAAPV) and Eglin C on the FMLP-induced increases in {sup 51}Cr-EDTA clearance were determined.

  6. 76 FR 59379 - Proposed Information Collection; Comment Request; Generic Clearance for Research in Development...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-26

    ... will collect qualitative data through a variety of collection methods, which may include interviews... disclosures and their implementation. The information collected through qualitative evaluation methods will... Clearance for Research in Development of Disclosure Forms September 20, 2011. Summary: The Bureau...

  7. 19 CFR 122.77 - Clearance certificate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Clearance certificate. 122.77 Section 122.77 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Documents Required for Clearance and Permission To Depart;...

  8. 30 CFR 56.7018 - Hand clearance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Hand clearance. 56.7018 Section 56.7018 Mineral... Drilling § 56.7018 Hand clearance. Persons shall not hold the drill steel while collaring holes, or rest their hands on the chuck or centralizer while drilling....

  9. 30 CFR 56.7018 - Hand clearance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Hand clearance. 56.7018 Section 56.7018 Mineral... Drilling § 56.7018 Hand clearance. Persons shall not hold the drill steel while collaring holes, or rest their hands on the chuck or centralizer while drilling....

  10. 30 CFR 57.7018 - Hand clearance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Hand clearance. 57.7018 Section 57.7018 Mineral... Drilling-Surface Only § 57.7018 Hand clearance. Persons shall not hold the drill steel while collaring holes, or rest their hands on the chuck or centralizer while drilling. Drilling—Underground Only...

  11. 30 CFR 57.7028 - Hand clearance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Hand clearance. 57.7028 Section 57.7028 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Drilling-Underground Only § 57.7028 Hand clearance. Persons shall not rest their hands on the chuck...

  12. 30 CFR 57.7028 - Hand clearance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Hand clearance. 57.7028 Section 57.7028 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Drilling-Underground Only § 57.7028 Hand clearance. Persons shall not rest their hands on the chuck...

  13. 30 CFR 57.7018 - Hand clearance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Hand clearance. 57.7018 Section 57.7018 Mineral... Drilling-Surface Only § 57.7018 Hand clearance. Persons shall not hold the drill steel while collaring holes, or rest their hands on the chuck or centralizer while drilling. Drilling—Underground Only...

  14. 30 CFR 57.7018 - Hand clearance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Hand clearance. 57.7018 Section 57.7018 Mineral... Drilling-Surface Only § 57.7018 Hand clearance. Persons shall not hold the drill steel while collaring holes, or rest their hands on the chuck or centralizer while drilling. Drilling—Underground Only...

  15. 30 CFR 56.7018 - Hand clearance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Hand clearance. 56.7018 Section 56.7018 Mineral... Drilling § 56.7018 Hand clearance. Persons shall not hold the drill steel while collaring holes, or rest their hands on the chuck or centralizer while drilling....

  16. 30 CFR 57.7018 - Hand clearance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Hand clearance. 57.7018 Section 57.7018 Mineral... Drilling-Surface Only § 57.7018 Hand clearance. Persons shall not hold the drill steel while collaring holes, or rest their hands on the chuck or centralizer while drilling. Drilling—Underground Only...

  17. 30 CFR 57.7028 - Hand clearance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Hand clearance. 57.7028 Section 57.7028 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Drilling-Underground Only § 57.7028 Hand clearance. Persons shall not rest their hands on the chuck...

  18. 30 CFR 57.7018 - Hand clearance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Hand clearance. 57.7018 Section 57.7018 Mineral... Drilling-Surface Only § 57.7018 Hand clearance. Persons shall not hold the drill steel while collaring holes, or rest their hands on the chuck or centralizer while drilling. Drilling—Underground Only...

  19. 30 CFR 57.7028 - Hand clearance.

    Code of Federal Regulations, 2010 CFR

    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... Drilling-Underground Only § 57.7028 Hand clearance. Persons shall not rest their hands on the chuck...

  20. 30 CFR 56.7018 - Hand clearance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Hand clearance. 56.7018 Section 56.7018 Mineral... Drilling § 56.7018 Hand clearance. Persons shall not hold the drill steel while collaring holes, or rest their hands on the chuck or centralizer while drilling....

  1. 30 CFR 56.7018 - Hand clearance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Hand clearance. 56.7018 Section 56.7018 Mineral... Drilling § 56.7018 Hand clearance. Persons shall not hold the drill steel while collaring holes, or rest their hands on the chuck or centralizer while drilling....

  2. 30 CFR 57.7028 - Hand clearance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Hand clearance. 57.7028 Section 57.7028 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Drilling-Underground Only § 57.7028 Hand clearance. Persons shall not rest their hands on the chuck...

  3. AHERA CLEARANCE AT TWENTY ABATEMENT SITES

    EPA Science Inventory

    A study was conducted during the summer of 1988 to document Asbestos Hazard Emergency Response Act (AHERA) clearance air-sampling practices and clearance concentrations of airborne asbestos at 20 asbestos-abatement sites in New Jersey. Each abatement took place in a school buildi...

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

    PubMed Central

    Sisson, Joseph H.; Wyatt, Todd A.; Pavlik, Jacqueline A.; Sarna, Pawanjit S.; 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 (NOx). Results. VCPT shorted NSTT by 35% in normal and stable CF subjects with no difference observed between the groups. EBC NOx concentrations decreased 68% in control subjects after VCPT (before = 115 ± 32 μM versus after = 37 ± 17 μM; P < 0.002). CF subjects had a trend toward lower EBC NOx. Conclusion. We found an association between VCPT-stimulated clearance and exhaled NOx levels in human subjects. We speculate that VCPT stimulates clearance via increased NO metabolism. PMID:24349778

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

    PubMed

    Sisson, Joseph H; Wyatt, Todd A; Pavlik, Jacqueline A; Sarna, Pawanjit S; 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 shorted NSTT by 35% in normal and stable CF subjects with no difference observed between the groups. EBC NO x concentrations decreased 68% in control subjects after VCPT (before = 115 ± 32  μ M versus after = 37 ± 17  μ M; P < 0.002). CF subjects had a trend toward lower EBC NO x . Conclusion. We found an association between VCPT-stimulated clearance and exhaled NO x levels in human subjects. We speculate that VCPT stimulates clearance via increased NO metabolism. PMID:24349778

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

    SciTech Connect

    Vissing, J.; Ohkuwa, Tetsuo; Ploug, T.; Galbo, H. Nagoya Institute of Technology )

    1988-10-01

    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-({sup 3}H)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.

  7. Seal Investigations of an Active Clearance Control System Concept

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M.; Taylor, Shawn; Oswald, Jay; DeCastro, Jonathan A.

    2006-01-01

    In an effort to improve upon current thermal active clearance control methods, a first generation, fast-acting mechanically actuated, active clearance control system has been designed and installed into a non-rotating test rig. In order to harvest the benefit of tighter blade tip clearances, low-leakage seals are required for the actuated carrier segments of the seal shroud to prevent excessive leakage of compressor discharge (P3) cooling air. The test rig was designed and fabricated to facilitate the evaluation of these types of seals, identify seal leakage sources, and test other active clearance control system concepts. The objective of this paper is to present both experimental and analytical investigations into the nature of the face-seal to seal-carrier interface. Finite element analyses were used to examine face seal contact pressures and edge-loading under multiple loading conditions, varied E-seal positions and two new face seal heights. The analyses indicated that moving the E-seal inward radially and reducing face seal height would lead to more uniform contact conditions between the face seal and the carriers. Lab testing confirmed that moving the balance diameter inward radially caused a decrease in overall system leakage.

  8. Spontaneous Clearance of the Hepatitis C Virus Among Men Who Have Sex With Men

    PubMed Central

    Seaberg, Eric C.; Witt, Mallory D.; Jacobson, Lisa P.; Detels, Roger; Rinaldo, Charles R.; Margolick, Joseph B.; Young, Stephen; Phair, John P.; Thio, Chloe L.

    2015-01-01

    Background. The probability of spontaneous hepatitis C virus (HCV) clearance ranges from 11% to 49%. Our previous cross-sectional study suggests that mode of acquisition explains some of this heterogeneity. We performed this prospective study to determine factors associated with spontaneous HCV clearance among men who have sex with men (MSM). Methods. A mixture-cure model was used to evaluate the probability of spontaneous HCV clearance among 101 MSM in the Multicenter AIDS Cohort Study with acute HCV infection between 1984 and 2012. Results. Spontaneous HCV clearance occurred in 46% of MSM (49% in non-injection drug users [IDUs] and 23% in IDUs). In the multivariable analysis, age <30 years (clearance ratio [CR] = 2.43; 95% confidence interval [CI], 1.53–3.87) and being human immunodeficiency virus (HIV) uninfected (CR = 2.97; 95% CI, 1.98–4.46) were independently associated with spontaneous clearance. Among men aged ≥30 years, being HIV uninfected, not having unprotected anal intercourse, older age, and being on highly active antiretroviral therapy were independently associated with higher clearance. The interferon lambda rs12979860 single nucleotide polymorphism (SNP) was not associated with spontaneous clearance among the 88 MSM who were not active IDUs (CR = 0.74; 95% CI, .46–1.21 for CC vs CT/TT genotype). Conclusions. The high probability of spontaneous HCV clearance together with the lack of an association between the rs12979860 SNP and spontaneous clearance among MSM who do not use injection drugs suggests that the immune mechanisms involved with a successful response to acute HCV differ by mode of virus acquisition. Understanding potential mechanistic differences could be important for HCV vaccine development. PMID:26175521

  9. Research on the effect of wear-ring clearances to the performance of centrifugal pump

    NASA Astrophysics Data System (ADS)

    Zhao, W. G.; Li, Y. B.; Wang, X. Y.; Sun, J. P.; Wu, G. X.

    2012-11-01

    In order to study the effect of wear-ring clearance on the performance of centrifugal pump, based on the Reynolds Time-Averaged N-S equations and RNG k-ε turbulence model, a centrifugal pump was simulated with three variable styles of the wear-rings: Only the clearance of the front wear-ring was changed, only the clearance of the back wear-ring was changed and both were changed. Numerical results agree well with the experimental results. In the three changing styles of the clearance, the variable of the clearance of front wear-ring has the most influence on the performance of centrifugal pump. The existence of wear-ring not only has an effect on the volumetric loss of the centrifugal pump, but also on the performance of the centrifugal pump. Relative to the experimental studies, numerical simulation methods have some advantages, such as low cost, fast and efficient, and easy to get the detailed structure of the internal flow characteristics, so it has been widely used in the fluid machinery study. In order to study the effect of wear-ring clearance on the performance of centrifugal pump, based on the Reynolds Time-Averaged N-S equations and RNG k-ε turbulence model, a centrifugal pump was simulated with three variable styles of the wear-rings: Only the clearance of the front wear-ring was changed, only the clearance of the back wear-ring was changed and both were changed. Numerical results agree well with the experimental results. In the three changing styles of the clearance, the variable of the clearance of front wear-ring has the most influence on the performance of centrifugal pump.

  10. Humanitarian IED clearance in Colombia

    NASA Astrophysics Data System (ADS)

    Hendrickx, J. M. H.; Molina, A.; Diaz, D.; Grasmueck, M.; Moreno, H. A.; Hernández, R. D.

    2008-04-01

    The development of Improvised Explosive Devices (IED's) by insurgents in Colombia is characterized by a quick response to counter IED measures. Many current IED's do not contain any metal parts and can have any shape or form. Due to the low metal content or the absence of any metal parts, sensors based on metal detection are not useful anymore. Due to the wide variety of sizes, shapes, and enclosure materials of current IED's, one and two-dimensional GPR sensors using a "library" of known shapes as well as acoustic sensors using material characteristic frequencies have become ineffective. Therefore, the Colombian experience strongly suggests that chemical sensors are the way for IED detection in soils since they do not depend on IED metal content, size, or shape but only on the presence of explosives, a necessary ingredient for any IED. Promising recently developed chemical sensors make use of semiconducting organic polymers (SOPs) such as FIDO and laser-induced breakdown spectroscopy (LIBS). Once an explosive has been detected, the IED needs to be identified and located. Therefore, there is a need for three-dimensional high resolution scans for identification of all subsoil features including rocks, roots, and IED's. The recently developed 3D-GPR (Ground Penetrating Radar) can map all features of the subsoil with a spatial resolution of about 2 cm or less. The objectives of this contribution are to inform about the IED problem in Colombia and how novel technologies may contribute to humanitarian IED clearance under humid tropical conditions.

  11. Advanced optical blade tip clearance measurement system

    NASA Technical Reports Server (NTRS)

    Ford, M. J.; Honeycutt, R. E.; Nordlund, R. E.; Robinson, W. W.

    1978-01-01

    An advanced electro-optical system was developed to measure single blade tip clearances and average blade tip clearances between a rotor and its gas path seal in an operating gas turbine engine. This system is applicable to fan, compressor, and turbine blade tip clearance measurement requirements, and the system probe is particularly suitable for operation in the extreme turbine environment. A study of optical properties of blade tips was conducted to establish measurement system application limitations. A series of laboratory tests was conducted to determine the measurement system's operational performance characteristics and to demonstrate system capability under simulated operating gas turbine environmental conditions. Operational and environmental performance test data are presented.

  12. Faecalibacterium prausnitzii supernatant improves intestinal barrier function in mice DSS colitis.

    PubMed

    Carlsson, Anders H; Yakymenko, Olena; Olivier, Isabelle; Håkansson, Fathima; Postma, Emily; Keita, Asa V; Söderholm, Johan D

    2013-10-01

    OBJECTIVE. The intestinal microbiota plays a substantial role in the pathogenesis of inflammatory bowel disease (IBD). Faecalibacterium prausnitzii (FP) is underrepresented in IBD patients and have been suggested to have anti-inflammatory effects in mice. Increased intestinal permeability is common in IBD but the relationship between FP and intestinal barrier function has not been investigated. Our aim was to study treatment with FP supernatant on intestinal barrier function in a dextran sodium sulfate (DSS) colitis mice model. MATERIAL AND METHODS. C57BL/6 mice received 3% DSS in tap water ad libitum during five days to induce colitis. From day 3 the mice received a daily gavage with FP supernatant or broth during seven days. Ileum and colon were mounted in Ussing chambers for permeability studies with (51)Cr-EDTA and Escherichia coli K-12. Colon was saved for Western blot analyses of tight junction proteins. RESULTS. DSS-treated mice showed significant weight loss and colon shortening. Gavage with FP supernatant resulted in a quicker recovery after DSS treatment and less extensive colonic shortening. Ileal mucosa of DSS mice showed a significant increase in (51)Cr-EDTA-passage compared to controls. (51)Cr-EDTA passage was significantly decreased in mice receiving FP supernatant. No significant differences were observed in passage of E. coli K12. Western blots showed a trend to increased claudin-1 and claudin-2 expressions in DSS mice. CONCLUSIONS. Supernatant of FP enhances the intestinal barrier function by affecting paracellular permeability, and may thereby attenuate the severity of DSS-induced colitis in mice. These findings suggest a potential role of FP in the treatment of IBD.

  13. 33 CFR 117.47 - Clearance gauges.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 117.47 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE... specify otherwise for particular drawbridges, clearance gauges shall be designed, installed, and... appropriate bridge....

  14. 49 CFR 192.325 - Underground clearance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... installed with enough clearance from any other underground structure to allow proper maintenance and to... prevent the heat from impairing the serviceability of the pipe. (d) Each pipe-type or bottle-type...

  15. Compressor airfoil tip clearance optimization system

    DOEpatents

    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.

  16. Voltage-clearance recommendations for printed boards

    SciTech Connect

    Jennings, C W; Cave, G; Evans, A; Harrington, D J; Kirchenbaum, J; Martz, R E; Mierendorf, R C; Smith, G A

    1980-01-01

    Present and future trends in printed board designs point to higher circuit densities with narrower lines and closer spacings. Some designers are now laying out boards with 0.13 mm lines and spacings. The reduction of nominal spacing between conductive elements has raised questions concerning the adequacy of present voltage-clearance recommendations. The present recommendations are considered too conservative in that they are weighted with large safety factors, especially for small clearances, and are frequently disregarded by many designers. Published voltage breakdown measurements made on printed boards with comb patterns with their enhanced conductor test lengths show breakdowns occurring at much higher voltages than those specified for the clearances in existing documents. A Task Group was set up to review published breakdown measurements and to make any additional measurements necessary to provide voltage-clearance recommendations. These recommendations are reported.

  17. Controls Considerations for Turbine Active Clearance Control

    NASA Technical Reports Server (NTRS)

    Melcher, Kevin J.

    2004-01-01

    This presentation discusses active control of turbine tip clearance from a control systems perspective. It is a subset of charts that were presented at the 2003 meeting of the International Society of Air Breathing Engines which was held August 31 through September 5 in Cleveland, Ohio. The associated reference paper is cited at the end of the presentation. The presentation describes active tip clearance control research being conducted by NASA to improve turbine engine systems. The target application for this effort is commercial aircraft engines. However, it is believed that the technologies developed as part of this research will benefit a broad spectrum of current and future turbomachinery. The first part of the presentation discusses the concept of tip clearance, problems associated with it, and the benefits of controlling it. It lays out a framework for implementing tip clearance controls that enables the implementation to progress from purely analytical to hardware-in-the-loop to fully experimental. And it briefly discusses how the technologies developed will be married to the previously described ACC Test Rig for hardware-in-the-loop demonstrations. The final portion of the presentation, describes one of the key technologies in some detail by presenting equations and results for a functional dynamic model of the tip clearance phenomena. As shown, the model exhibits many of the clearance dynamics found in commercial gas turbine engines. However, initial attempts to validate the model identified limitations that are being addressed to make the model more realistic.

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

    NASA Astrophysics Data System (ADS)

    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.

  19. 48 CFR 801.602-76 - Business clearance review.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 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 a... obtain a business clearance review prior to award of any contract, task or delivery order, or...

  20. 48 CFR 801.602-76 - Business clearance review.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false Business clearance review... Authority, and Responsibilities 801.602-76 Business clearance review. (a) A business clearance review is a... obtain a business clearance review prior to award of any contract, task or delivery order, or...

  1. 48 CFR 801.602-76 - Business clearance review.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 5 2013-10-01 2013-10-01 false Business clearance review... Authority, and Responsibilities 801.602-76 Business clearance review. (a) A business clearance review is a... obtain a business clearance review prior to award of any contract, task or delivery order, or...

  2. 48 CFR 945.603-70 - Plant clearance function.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 5 2012-10-01 2012-10-01 false Plant clearance function... Plant clearance function. If the plant clearance function has not been formally delegated to another Federal agency, the contracting officer shall assume all responsibilities of the plant clearance...

  3. 48 CFR 945.603-70 - Plant clearance function.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Plant clearance function... Plant clearance function. If the plant clearance function has not been formally delegated to another Federal agency, the contracting officer shall assume all responsibilities of the plant clearance...

  4. 31 CFR 205.20 - What is a clearance pattern?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false What is a clearance pattern? 205.20... Agreement § 205.20 What is a clearance pattern? States use clearance patterns to project when funds are paid... is applied. (c) A clearance pattern must include seasonal or other periodic variations in...

  5. Lower metabolic clearance of tizanidine in Japanese subjects.

    PubMed

    Momo, Kenji; Homma, Masato; Kohda, Yukinao

    2013-12-01

    Our aim was to determine whether metabolic clearance, renal clearance, or both elimination pathways contribute to ethnic differences in tizanidine clearance, which is ~ 2-fold higher in Caucasians than in Asians. The pharmacokinetic parameters of tizanidine in 9 healthy male Japanese subjects were compared with those of Caucasians in previous studies. Metabolic clearance of tizanidine was lower in Japanese than in Caucasian subjects (5.9 vs. 8.1 - 10.9 l/h/kg), although renal clearances were similar (0.040 vs. 0.047 - 0.055 l/h/kg). The results suggest that ethnic differences in tizanidine clearance are due to differences in metabolic clearance.

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

    PubMed Central

    2010-01-01

    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 < 0.05). During the follow-up, 9/11 of the patients who had to start dialysis came from the half with the largest kidneys (LogRank: p < 0.05), despite a 40% higher initial isotopic GFR. Serum creatinine were initially lower (Small kidneys: 125 (79-320) μmol/L, Large: 103 (50-371), p < 0.05), but significantly increased in the "large kidneys" group at the end of the follow-up (Small kidneys: 129 (69-283) μmol/L, Large: 140 (50-952), p < 0.005 vs initial). The difference persisted in the patients with severe renal failure (KDOQI stages 4,5). 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. PMID:20199663

  7. The effects of walking speed on minimum toe clearance and on the temporal relationship between minimum clearance and peak swing-foot velocity in unilateral trans-tibial amputees

    PubMed Central

    De Asha, Alan R

    2015-01-01

    Background: Minimum toe clearance is a critical gait event because it coincides with peak forward velocity of the swing foot, and thus, there is an increased risk of tripping and falling. Trans-tibial amputees have increased risk of tripping compared to able-bodied individuals. Assessment of toe clearance during gait is thus clinically relevant. In able-bodied gait, minimum toe clearance increases with faster walking speeds, and it is widely reported that there is synchronicity between when peak swing-foot velocity and minimum toe clearance occur. There are no such studies involving lower-limb amputees. Objectives: To determine the effects of walking speed on minimum toe clearance and on the temporal relationship between clearance and peak swing-foot velocity in unilateral trans-tibial amputees. Study design: Cross-sectional. Methods: A total of 10 trans-tibial participants walked at slow, customary and fast speeds. Minimum toe clearance and the timings of minimum toe clearance and peak swing-foot velocity were determined and compared between intact and prosthetic sides. Results: Minimum toe clearance was reduced on the prosthetic side and, unlike on the intact side, did not increase with walking speed increase. Peak swing-foot velocity consistently occurred (~0.014 s) after point of minimum toe clearance on both limbs across all walking speeds, but there was no significant difference in the toe–ground clearance between the two events. Conclusion: The absence of speed related increases in minimum toe clearance on the prosthetic side suggests that speed related modulation of toe clearance for an intact limb typically occurs at the swing-limb ankle. The temporal consistency between peak foot velocity and minimum toe clearance on each limb suggests that swing-phase inter-segmental coordination is unaffected by trans-tibial amputation. Clinical relevance The lack of increase in minimum toe clearance on the prosthetic side at higher walking speeds may potentially

  8. 75 FR 38959 - Lead; Clearance and Clearance Testing Requirements for the Renovation, Repair, and Painting...

    Federal Register 2010, 2011, 2012, 2013, 2014

    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,...

  9. Extreme contagion in global habitat clearance.

    PubMed

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

    2010-04-01

    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 intact habitat. Here, we test the strength of spatial contagion in the pattern of habitat clearance. Using a global dataset of land-cover change at 50 x 50 km resolution, we discover that intact habitat areas in grid cells are refractory to clearance only when all neighbouring cells are also intact. The likelihood of loss increases dramatically as soon as habitat is cleared in just one neighbouring cell, and remains high thereafter. This effect is consistent for forests and grassland, across biogeographic realms and over centuries, constituting a coherent global pattern. Our results show that landscapes become vulnerable to wholesale clearance as soon as threatening processes begin to penetrate, so actions to prevent any incursions into large, intact blocks of natural habitat are key to their long-term persistence.

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

    PubMed

    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

  11. Characterizing clearance of helper adenovirus by a clinical rAAV1 manufacturing process.

    PubMed

    Thorne, Barbara A; Quigley, Paulene; Nichols, Gina; Moore, Christine; Pastor, Eric; Price, David; Ament, Jon W; Takeya, Ryan K; Peluso, Richard W

    2008-01-01

    Recombinant adeno-associated viral vectors (rAAV) are being developed as gene therapy delivery vehicles and as genetic vaccines, and some of the most scaleable manufacturing methods for rAAV use live adenovirus to induce production. One aspect of establishing safety of rAAV products is therefore demonstrating adequate and reliable clearance of this helper virus by the vector purification process. The ICH Q5A regulatory guidance on viral safety provides recommendations for process design and characterization of viral clearance for recombinant proteins, and these principles were adapted to a rAAV serotype 1 purification process for clinical vectors. Specific objectives were to achieve overall adenovirus clearance factors significantly greater than input levels by using orthogonal separation and inactivation methods, and to segregate adenovirus from downstream operations by positioning a robust clearance step early in the process. Analytical tools for process development and characterization addressed problematic in-process samples, and a viral clearance validation study was performed using adenovirus and two non-specific model viruses. Overall clearance factors determined were >23 LRV for adenovirus, 11 LRV for BVDV, and >23 LRV for AMuLV.

  12. Colchicine clearance is impaired in alcoholic cirrhosis.

    PubMed

    Leighton, J A; Bay, M K; Maldonado, A L; Schenker, S; Speeg, K V

    1991-12-01

    Colchicine may have benefit in primary biliary cirrhosis and alcoholic liver disease. It is currently used in patients with impaired liver function, yet little is known about its elimination in such patients. Colchicine clearance in the rat is significantly impaired in various models of liver disease. To study this in human beings, colchicine pharmacokinetics were compared in normal subjects and patients with alcoholic cirrhosis. Colchicine clearance was impaired in the cirrhotic patients. Normal subjects had a mean clearance of 10.65 +/- 1.82 ml/min.kg, whereas cirrhotic patients had a mean clearance of 4.22 +/- 0.45 ml/min.kg (p less than 0.01). The half-life was 57.4 +/- 14.2 min in control subjects vs. 114.4 +/- 19.7 min in cirrhotic patients (p = 0.054). Volume of distribution was not different in the two groups (0.718 +/- 0.1 L/kg in control subjects; 0.716 +/- 0.158 L/kg in cirrhotic patients, p greater than 0.99). No correlation was seen between colchicine clearance and bilirubin, albumin, prothrombin time or Child-Pugh classification, but this may be the result of the small number of patients studied. Based on the values measured, it is estimated that colchicine steady state would change from an average 1.12 ng/ml in normal individuals to 2.82 ng/ml in the cirrhotic patients if 0.6 mg were taken every 12 hr. It is unknown whether this change would be clinically significant. These data show that cirrhosis impairs colchicine clearance and demonstrates that the liver is a major route of colchicine elimination.

  13. Active clearance control system for a turbomachine

    NASA Technical Reports Server (NTRS)

    Johnston, R. P.; Knapp, M. H.; Coulson, C. E. (Inventor)

    1982-01-01

    An axial compressor is provided with a cooling air manifold surrounding a portion of the shroud, and means for bleeding air from the compressor to the manifold for selectively flowing it in a modulating manner axially along the outer side of the stator/shroud to cool and shrink it during steady state operating conditions so as to obtain minimum shroud/rotor clearance conditions. Provision is also made to selectively divert the flow of cooling air from the manifold during transient periods of operation so as to alter the thermal growth or shrink rate of the stator/shroud and result in adequate clearance with the compressor rotor.

  14. Pharmacologic agents for mucus clearance in bronchiectasis.

    PubMed

    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

  15. Pharmacologic agents for mucus clearance in bronchiectasis.

    PubMed

    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.

  16. Prediction of hepatic microsomal intrinsic clearance and human clearance values for drugs.

    PubMed

    Nikolic, Katarina; Agababa, Danica

    2009-10-01

    Twenty-nine drugs of different structures were used in theoretical QSAR analysis of human hepatic microsomal intrinsic clearance (in vitro T(1/2) and in vitro CL'(int)) and whole body clearance (CL(blood)). The examined compounds demonstrated a wide range of scaled intrinsic clearance values. Constitutional, geometrical, physico-chemical and electronic descriptors were computed for the examined structures by use of the Marvin Sketch 5.1.3_2, the Chem3D Ultra 7.0.0 and the Dragon 5.4 program. Partial least squares regression (PLSR), has been applied for selection of the most relevant molecular descriptors and development of quantitative structure-activity relationship (QSAR) model for human hepatic microsomal intrinsic clearance (in vitro T(1/2)). Optimal QSAR models with nine and ten variables, R(2)>0.808 and cross-validation parameter q(pre)(2)>0.623, were selected and compared. Since the microsomal in vitro T(1/2) data can be used for calculation of in vitro CL'(int) and in vivo CL(blood), the developed QSAR model will enable one to analyze the kinetics of cytochrome P450-mediated reactions in term of intrinsic clearance and whole body clearance. A comparison is made between predictions produced from the QSAR analysis and experimental data, and there appears to be generally satisfactory correlations with the literature values for intrinsic clearance data. PMID:19713138

  17. Clinical evaluation of amylase-creatinine clearance ratio and amylase isoenzyme clearance in chronic renal failure.

    PubMed

    Maeda, M; Otsuki, M; Okano, K; Yamasaki, T; Baba, S

    1981-01-01

    Amylase-creatinine clearance ratio (ACCR) and amylase isoenzyme clearance were determined simultaneously in patients with chronic renal failure. ACCR in patients with compensated renal failure (3.5 +/- 0.4%) was not significantly different from normals (2.6 +/- 0.2%), while that in patients with non-compensated renal failure (6.7 +/- 0.4%) was significantly higher than that in normals. Clearance ratio of pancreatic isoamylase (Amylase-1) relative to creatinine clearance (CAmy . 1/Ccr) in patients with both compensated (5.9 +/- 1.0%) and non-compensated (6.8 +/- 0.4%) renal failure was as high as that in patients with acute pancreatitis (6.6 +/- 0.5%). On the other hand, clearance ratio of salivary isoamylase (Amylase-3) relative to creatinine clearance (CAmy . 3/CCr) in patients with compensated renal failure (1.5 +/- 0.3%) was almost the same as that in normals (2.1 +/- 0.1%), while that in patients with non-compensated renal failure was 5.9 +/- 0.7%, which was significantly higher than that in normals. The present study revealed that elevated ACCR in patients with severely impaired renal function was due to the increase of the clearance ratio for both pancreatic and salivary amylase. These facts suggested that glomerular permeability and tubular reabsorption for pancreatic and salivary amylase might play an important role on ACCR in patients with severely impaired renal function.

  18. Clinical evaluation of amylase-creatinine clearance ratio and amylase isoenzyme clearance in chronic renal failure.

    PubMed

    Maeda, M; Otsuki, M; Okano, K; Yamasaki, T; Baba, S

    1981-01-01

    Amylase-creatinine clearance ratio (ACCR) and amylase isoenzyme clearance were determined simultaneously in patients with chronic renal failure. ACCR in patients with compensated renal failure (3.5 +/- 0.4%) was not significantly different from normals (2.6 +/- 0.2%), while that in patients with non-compensated renal failure (6.7 +/- 0.4%) was significantly higher than that in normals. Clearance ratio of pancreatic isoamylase (Amylase-1) relative to creatinine clearance (CAmy . 1/Ccr) in patients with both compensated (5.9 +/- 1.0%) and non-compensated (6.8 +/- 0.4%) renal failure was as high as that in patients with acute pancreatitis (6.6 +/- 0.5%). On the other hand, clearance ratio of salivary isoamylase (Amylase-3) relative to creatinine clearance (CAmy . 3/CCr) in patients with compensated renal failure (1.5 +/- 0.3%) was almost the same as that in normals (2.1 +/- 0.1%), while that in patients with non-compensated renal failure was 5.9 +/- 0.7%, which was significantly higher than that in normals. The present study revealed that elevated ACCR in patients with severely impaired renal function was due to the increase of the clearance ratio for both pancreatic and salivary amylase. These facts suggested that glomerular permeability and tubular reabsorption for pancreatic and salivary amylase might play an important role on ACCR in patients with severely impaired renal function. PMID:6167484

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

    NASA Astrophysics Data System (ADS)

    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.

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

    SciTech Connect

    Peterson, B.T.; James, H.L.; McLarty, J.W.

    1988-03-01

    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 cmH/sub 2/O 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.

  1. 32 CFR 154.16 - Security clearance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 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 this...); where the full investigative coverage cannot be completed, a counterintelligence scope...

  2. 32 CFR 154.48 - Issuing clearance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., separated from DoD civilian employment, has no further official relationship with DoD, official action has... individual's relationship with DoD exists greater than 24 months and/or, the need for regular access to... Component may issue an interim clearance to personnel under their administrative jurisdiction pending...

  3. Waste Segregation Based on Derived Clearance Levels

    SciTech Connect

    Garisto, N.C.; Parhizgari, Z.

    2008-07-01

    This paper describes the methodology and results of a radiological modeling in support of an application to release very low level radiologically contaminated waste from regulatory control and allow its haulage and disposal in a hazardous waste landfill. The Canadian regulatory body responsible for licensing operations involving nuclear materials (the Canadian Nuclear Safety Commission), has not yet formally defined clearance levels for free release of low level radiologically contaminated waste. The IAEA clearance levels have been derived for certain situations and receptor characteristics, which might be too conservative for an actual case. A site-specific pathways analysis was therefore completed to define conditional clearance levels using the concept of de minimis dose limit. Derived Conditional Clearance Levels were calculated for each radionuclide based on the maximally exposed hypothetical individuals to determine whether each waste stream can be 'cleared' from regulatory controls. The results showed that haulage of the waste from the station to the haulage/processing facility and transportation of waste or sludge from the haulage/processing facility to the disposal facility, handling of the waste or sludge at the haulage/processing facility, and incineration and/or disposal of waste or sludge at the disposal facility would not expose the workers to doses above 0.1 {mu}Sv/yr., which is less than the de minimis dose limit of 10 {mu}Sv/yr. (authors)

  4. Mediators and mucociliary clearance in asthma.

    PubMed

    Pavia, D; Lopez-Vidriero, M T; Clarke, S W

    1987-01-01

    Lung mucociliary clearance is significantly reduced in asthmatic patients compared to healthy controls even during clinical remission. Further retardation in mucous clearance occurs during sleep per se and this may be a contributing factor to nocturnal asthma. Chemical mediators of anaphylaxis appear to have various and, sometimes opposing effects on the two essential components for mucociliary clearance, namely cilia and mucus. Some mediators such as leukotrienes C4 and D4 are potent secretagogues and histamine increases the water flux into the lumen of the airways from the mucosa. Slow-reacting substance of anaphylaxis (SRS-A) reduces mucus transport whereas histamine enhances it. Ciliostimulation has been reported following allergen challenge and this contrasts with the cilioinhibitory effect of asthmatics' sputa. It appears however, that the net effect of the various chemicals of anaphylaxis is one of impairment of mucus clearance. Some pharmacological agents, used for the relief of bronchospasm and control of asthma, also stimulate mucociliary transport, a desirable additional effect. PMID:3311245

  5. 32 CFR 154.16 - Security clearance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 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 this... cleared personnel. (7) To food service personnel, vendors and similar commercial sales or...

  6. 15 CFR 752.15 - Export clearance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... accordance with requirements of the Foreign Trade Statistics Regulations (15 CFR part 30) and § 758.1 of the... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Export clearance. 752.15 Section 752... OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE EXPORT ADMINISTRATION REGULATIONS...

  7. Airway Clearance Devices for Cystic Fibrosis

    PubMed Central

    2009-01-01

    Executive Summary Objective The purpose of this evidence-based analysis is to examine the safety and efficacy of airway clearance devices (ACDs) for cystic fibrosis and attempt to differentiate between devices, where possible, on grounds of clinical efficacy, quality of life, safety and/or patient preference. Background Cystic fibrosis (CF) is a common, inherited, life-limiting disease that affects multiple systems of the human body. Respiratory dysfunction is the primary complication and leading cause of death due to CF. CF causes abnormal mucus secretion in the airways, leading to airway obstruction and mucus plugging, which in turn can lead to bacterial infection and further mucous production. Over time, this almost cyclical process contributes to severe airway damage and loss of respiratory function. Removal of airway secretions, termed airway clearance, is thus an integral component of the management of CF. A variety of methods are available for airway clearance, some requiring mechanical devices, others physical manipulation of the body (e.g. physiotherapy). Conventional chest physiotherapy (CCPT), through the assistance of a caregiver, is the current standard of care for achieving airway clearance, particularly in young patients up to the ages of six or seven. CF patients are, however, living much longer now than in decades past. The median age of survival in Canada has risen to 37.0 years for the period of 1998-2002 (5-year window), up from 22.8 years for the 5-year window ending in 1977. The prevalence has also risen accordingly, last recorded as 3,453 in Canada in 2002, up from 1,630 in 1977. With individuals living longer, there is a greater need for independent methods of airway clearance. Airway Clearance Devices There are at least three classes of airway clearance devices: positive expiratory pressure devices (PEP), airway oscillating devices (AOD; either handheld or stationary) and high frequency chest compression (HFCC)/mechanical percussion (MP

  8. 19 CFR 122.26 - Entry and clearance.

    Code of Federal Regulations, 2010 CFR

    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....

  9. 75 FR 70341 - Agency Information Collection Activities: Emergency Clearance Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-17

    ... From the Federal Register Online via the Government Publishing Office SOCIAL SECURITY ADMINISTRATION Agency Information Collection Activities: Emergency Clearance Request The Social Security..._Submission@omb.eop.gov . (SSA), Social Security Administration, DCBFM, Attn: Reports Clearance Officer,...

  10. 10 CFR 95.17 - Processing facility clearance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... NUCLEAR REGULATORY COMMISSION (CONTINUED) FACILITY SECURITY CLEARANCE AND SAFEGUARDING OF NATIONAL... of the Facility Clearance would not be inconsistent with the national interest, including a finding... concerning the foreign intelligence threat, risk of unauthorized technology transfer, type and sensitivity...

  11. 10 CFR 95.17 - Processing facility clearance.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... NUCLEAR REGULATORY COMMISSION (CONTINUED) FACILITY SECURITY CLEARANCE AND SAFEGUARDING OF NATIONAL... of the Facility Clearance would not be inconsistent with the national interest, including a finding... concerning the foreign intelligence threat, risk of unauthorized technology transfer, type and sensitivity...

  12. 10 CFR 95.17 - Processing facility clearance.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... NUCLEAR REGULATORY COMMISSION (CONTINUED) FACILITY SECURITY CLEARANCE AND SAFEGUARDING OF NATIONAL... of the Facility Clearance would not be inconsistent with the national interest, including a finding... concerning the foreign intelligence threat, risk of unauthorized technology transfer, type and sensitivity...

  13. WWW-based data entry for document clearance requests

    SciTech Connect

    Stasiak, D.M.

    1997-10-08

    All documents created at Argonne must be cleared before being published. The clearance process is coordinated by the Publications and Record Services. The Electronic Document Review and Clearance System (EDRC) consists of a Web-based system for submission of clearance requests, an electronic staging area for document awaiting review, and Web-based review and clearance of documents. This report covers the document clearing process, the EDRC system, expected benefits/costs, and a demonstration.

  14. What is the best airway clearance technique in cystic fibrosis?

    PubMed

    Main, Eleanor

    2013-05-01

    The global development of airway clearance techniques (ACTs) for cystic fibrosis (CF) and corresponding research spans over four decades. Five Cochrane reviews synthesising the evidence from a plethora of early short and medium term studies have not uncovered any superior method. Four recent long term RCT studies exposed fundamental shortcomings in the standard RCT trial design and the insensitivity of FEV1 in physiotherapy studies. Strong patient preference, lack of blinding and the requirement for effortful and demanding participation over long intervals will continue to derail efforts to find the best ACT for CF, unless they are addressed in future clinical trials. PMID:23541002

  15. 14 CFR 1260.63 - Customs clearance and visas.

    Code of Federal Regulations, 2010 CFR

    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...

  16. 30 CFR 57.9330 - Clearance for surface equipment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Clearance for surface equipment. 57.9330... Dumping Sites § 57.9330 Clearance for surface equipment. Continuous clearance of at least 30 inches from... tracks at all locations where possible or the area shall be marked conspicuously....

  17. 30 CFR 56.9330 - Clearance for surface equipment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Clearance for surface equipment. 56.9330... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Loading... Dumping Sites § 56.9330 Clearance for surface equipment. Continuous clearance of at least 30 inches...

  18. 30 CFR 56.9330 - Clearance for surface equipment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Clearance for surface equipment. 56.9330... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Loading... Dumping Sites § 56.9330 Clearance for surface equipment. Continuous clearance of at least 30 inches...

  19. 30 CFR 57.9330 - Clearance for surface equipment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Clearance for surface equipment. 57.9330... Dumping Sites § 57.9330 Clearance for surface equipment. Continuous clearance of at least 30 inches from... tracks at all locations where possible or the area shall be marked conspicuously....

  20. 30 CFR 56.9330 - Clearance for surface equipment.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Clearance for surface equipment. 56.9330... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Loading... Dumping Sites § 56.9330 Clearance for surface equipment. Continuous clearance of at least 30 inches...

  1. 30 CFR 57.9330 - Clearance for surface equipment.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Clearance for surface equipment. 57.9330... Dumping Sites § 57.9330 Clearance for surface equipment. Continuous clearance of at least 30 inches from... tracks at all locations where possible or the area shall be marked conspicuously....

  2. 46 CFR 56.75-10 - Joint clearance.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 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...

  3. 46 CFR 56.75-10 - Joint clearance.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 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...

  4. 46 CFR 56.75-10 - Joint clearance.

    Code of Federal Regulations, 2010 CFR

    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...

  5. 46 CFR 56.75-10 - Joint clearance.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 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...

  6. 46 CFR 56.75-10 - Joint clearance.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 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...

  7. 48 CFR 245.602-70 - Plant clearance procedures.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Plant clearance procedures... Disposal 245.602-70 Plant clearance procedures. Follow the procedures at PGI 245.602-70 for establishing and processing a plant clearance case....

  8. 48 CFR 245.602-70 - Plant clearance procedures.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false Plant clearance procedures... Disposal 245.602-70 Plant clearance procedures. Follow the procedures at PGI 245.602-70 for establishing and processing a plant clearance case....

  9. 48 CFR 945.670-1 - Plant clearance function.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... contracting officer shall assume all responsibilities of the plant clearance officer identified in 48 CFR 45... 48 Federal Acquisition Regulations System 5 2013-10-01 2013-10-01 false Plant clearance function... MANAGEMENT GOVERNMENT PROPERTY Reporting, Reutilization, and Disposal 945.670-1 Plant clearance function....

  10. 48 CFR 245.602-70 - Plant clearance procedures.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Plant clearance procedures... Disposal 245.602-70 Plant clearance procedures. Follow the procedures at PGI 245.602-70 for establishing and processing a plant clearance case....

  11. 75 FR 37518 - Agency Information Collection Activities: Emergency Clearance Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-29

    ... ADMINISTRATION Agency Information Collection Activities: Emergency Clearance Request The Social Security...@ssa.gov . SSA submitted the information collection below to OMB for Emergency Clearance. SSA is requesting Emergency Clearance from OMB no later than July 6, 2010. Individuals can obtain copies of...

  12. 32 CFR 644.517 - Clearance of Army lands.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Clearance of Army lands. 644.517 Section 644.517 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL PROPERTY REAL... and Improvements § 644.517 Clearance of Army lands. The responsibility for performing clearance...

  13. 32 CFR 644.517 - Clearance of Army lands.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 4 2011-07-01 2011-07-01 false Clearance of Army lands. 644.517 Section 644.517 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL PROPERTY REAL... and Improvements § 644.517 Clearance of Army lands. The responsibility for performing clearance...

  14. 48 CFR 245.602-70 - Plant clearance procedures.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Plant clearance procedures... Disposal 245.602-70 Plant clearance procedures. Follow the procedures at PGI 245.602-70 for establishing and processing a plant clearance case....

  15. 10 CFR 706.31 - Clearance of conciliators and arbitrators.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Clearance of conciliators and arbitrators. 706.31 Section... RELATIONS Contract Negotiation and Administration § 706.31 Clearance of conciliators and arbitrators. Conciliators and arbitrators who are regularly assigned to DOE cases may be processed for “Q” clearance at...

  16. 19 CFR 4.61 - Requirements for clearance.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 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....

  17. 7 CFR 1927.55 - Title clearance services.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 12 2010-01-01 2010-01-01 false Title clearance services. 1927.55 Section 1927.55... REGULATIONS TITLE CLEARANCE AND LOAN CLOSING Real Estate Title Clearance and Loan Closing § 1927.55 Title... borrower by a closing agent in connection with the transaction vary depending on whether a title...

  18. 32 CFR 644.69 - Title Clearance-Easements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Title Clearance-Easements. 644.69 Section 644.69... ESTATE HANDBOOK Acquisition Procurement of Title Evidence, Title Clearance, and Closings § 644.69 Title Clearance—Easements. (a) Easements Costing in Excess of $1,000. Curative action and clearance of title...

  19. 24 CFR 3285.305 - Clearance under homes.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 5 2011-04-01 2011-04-01 false Clearance under homes. 3285.305... URBAN DEVELOPMENT MODEL MANUFACTURED HOME INSTALLATION STANDARDS Foundations § 3285.305 Clearance under homes. A minimum clearance of 12 inches must be maintained between the lowest member of the main...

  20. 24 CFR 3285.305 - Clearance under homes.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Clearance under homes. 3285.305... URBAN DEVELOPMENT MODEL MANUFACTURED HOME INSTALLATION STANDARDS Foundations § 3285.305 Clearance under homes. A minimum clearance of 12 inches must be maintained between the lowest member of the main...

  1. 10 CFR 95.23 - Termination of facility clearance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Termination of facility clearance. 95.23 Section 95.23 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) FACILITY SECURITY CLEARANCE AND SAFEGUARDING OF NATIONAL SECURITY INFORMATION AND RESTRICTED DATA Physical Security § 95.23 Termination of facility clearance....

  2. 30 CFR 56.9330 - Clearance for surface equipment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Clearance for surface equipment. 56.9330... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Loading... Dumping Sites § 56.9330 Clearance for surface equipment. Continuous clearance of at least 30 inches...

  3. 30 CFR 57.9330 - Clearance for surface equipment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Clearance for surface equipment. 57.9330 Section 57.9330 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Dumping Sites § 57.9330 Clearance for surface equipment. Continuous clearance of at least 30 inches...

  4. Clearance of a Mucus Plug

    NASA Astrophysics Data System (ADS)

    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.

  5. Market Mechanism for Line Congestion Clearance

    NASA Astrophysics Data System (ADS)

    Ruiz Monroy, José Joaquín; Kita, Hiroyuki; Tanaka, Eiichi; Hasegawa, Jun

    This paper proposes a mechanism for clearance of line congestion and power flow control in a deregulated market environment. The mechanism applies penalties to the bilateral transactions that cause line congestion by increasing the prices of such transactions. The market regulates itself by redefining the transactions and checking again for violations, applying penalties if necessary and repeating the process until all the demand is satisfied without causing line congestion to the system. A bilateral transaction matrix (BTM) creation algorithm developed by the authors and a DC power flow program are integrated as parts of the market mechanism proposed in this paper. The congestion is cleared by the market participants when they reschedule their transactions. This mechanism is useful to study the effects of bilateral transactions on a power system and helps the Independent System Operator (ISO) to create rules and market mechanisms for line congestion clearance and power flow control.

  6. Airway clearance therapy: finding the evidence.

    PubMed

    Volsko, Teresa A

    2013-10-01

    Disease processes can impair ciliary function, alter secretion production and mucus rheology, and interfere with the cough reflex. Airway clearance therapy has been a cornerstone of therapy aimed at minimizing the devastating effects of airway obstruction, infection, and inflammation due to mucus stasis on the conducting airways and lung parenchyma. Although challenges to performing clinical studies evaluating the effectiveness of airway clearance therapeutic modalities exist, resources are available in the literature. In addition to device evaluations and original clinical research, the expert opinion, systematic reviews, and evidence-based practice guidelines can be found. These tools can be used to develop protocols and pathways to guide our practice. Monitoring and reporting patient, process, and financial outcomes are essential steps germane to the implementation of evidence-based care.

  7. Autophagy promotes DNA-protein crosslink clearance.

    PubMed

    Mu, Haibo; Liu, Qianjin; Niu, Hong; Wang, Dongdong; Tang, Jiangjiang; Duan, Jinyou

    2016-02-01

    Toxic DNA-protein crosslinks (DPCs) can result from exposure to radiation or chemotherapeutic agents. DPCs can also accumulate during aging or stress. However, the cellular mechanisms underlying clearance of DPCs remain largely unknown. Here, we have identified an important role of autophagy in the processing of DPCs induced by three representative agents: formaldehyde, a chemical used widely in industry; UV light; and camptothecin, a cytotoxic anticancer drug. Autophagy inhibitors, 3-methyladenine (3-MA) or chloroquine (CQ), promoted the accumulation of DPCs in damaged cells and injured organs. siRNA-mediated silencing of Atg5 or Atg7, two essential components for the formation of the autophagosome, gave similar results. In contrast, the autophagy inducer rapamycin (RAP) attenuated DPCs in vitro and in vivo. Our findings reveal the importance of autophagy in controlling the level of DPCs, and may open up a new avenue for understanding the formation and clearance of this detrimental DNA adduct. PMID:26921017

  8. Deposition and clearance of inhaled particles.

    PubMed Central

    Stuart, B O

    1976-01-01

    Theoretical models of respiratory tract deposition of inhaled particles are compared to experimental studies of deposition patterns in humans and animals, as determined principally by particle size, density, respiratory rate and flow parameters. Various models of inhaled particle deposition make use of convenient approximations of the respiratory tract to predict tractional deposition according to fundamental physical processes of impaction, sedimentation, and diffusion. These theoretical models for both total deposition and regional (nasopharyngeal, tracheobronchial, and pulmonary) deposition are compared with experimental studies of inhaled dusts in humans or experimental animals that have been performed in many laboratories over several decades. Reasonable correlation has been obtained between theoretical and experimental studies, but the behavior of very fine (less than 0.01 mum) particles requires further refinement.Properties of particle shape, charge, and hygroscopicity as well as the degree of respiratory tract pathology also influence deposition patterns and further experimental work is urgently needed in these areas. The influence upon deposition patterns of dynamic alterations in inspiratory flow profiles caused by a variety of breathing patterns also requires further study, and the use of such techniques with selected inhaled particle size holds promise in possible diagnostic aid in diagnosis of normal versus disease conditions. Mechanisms of conducting airway and alveolar clearance processes involving mucociliary clearance, dissolution, transport to systemic circulation, and translocation via regional lymphatic clearance are discussed. The roles of the pulmonary macrophage in airway and alveolar clearance are described, and the applicability of recent solubility models for translocation or deposited materials to liver, skeleton, or other systemic organs is discussed. PMID:797567

  9. Evidence for active maternal-fetal transport of Na+ across the placenta of the anaesthetized rat.

    PubMed

    Stulc, J; Stulcová, B; Sibley, C P

    1993-10-01

    1. In order to investigate mechanisms of Na+ transfer, the unidirectional maternal-fetal clearance (Kmf) of 22Na+ and of 51Cr-EDTA (a marker of paracellular diffusion) was measured across the intact or umbilically or dually perfused placenta of the anaesthetized rat. 2. The Kmf of 22Na+ in the intact preparation (18.5 +/- 2.7 microliters min-1, mean +/- S.D., n = 105 placentas) exceeded that of 51Cr-EDTA in the same experiments (1.4 +/- 0.3 microliters min-1) by more than ten times, whereas the difference in their diffusion coefficients in water was only 2-fold. In the perfused preparations the difference in the Kmf values was 6-fold. 3. Assuming that a simple model of paracellular diffusion through wide pores was one component of transfer, the Kmf of 51Cr-EDTA and the diffusion coefficients were used to calculate a component of 22Na+ clearance (Kmf,residual) and of Na+ flux (Jmf,residual) across the perfused placentas which could not be accounted for by transfer through the paracellular route. 4. Kmf,residual of 22Na+ across the dually perfused placenta was significantly lower when temperature was reduced, the temperature quotient (Q10) of the transfer being about 2. Kmf,residual was also significantly lower when 0.1 mM ouabain was perfused on the fetal side. Jmf,residual exhibited saturation kinetics characterized by an apparent Michaelis constant (Km) of 90 mM. Kmf,residual was not influenced by 0.5 mM frusemide, 0.5 mM amiloride or by 0.5 mM hydrochlorothiazide administered to the maternal side. It was significantly increased by 1 mM alanine on the maternal side suggesting that the coupled transfer of Na+ and amino acids may contribute significantly to the maternal-fetal flux of Na+. 5. These observations suggest that most (80%) of the maternal-fetal flux of Na+ across the rat placenta is effected by active transcellular transport. This transport involves passive entry of Na+ into the trophoblast from the maternal side by a largely unknown saturable mechanism

  10. Robust Foot Clearance Estimation Based on the Integration of Foot-Mounted IMU Acceleration Data.

    PubMed

    Benoussaad, Mourad; Sijobert, Benoît; Mombaur, Katja; Coste, Christine Azevedo

    2015-01-01

    This paper introduces a method for the robust estimation of foot clearance during walking, using a single inertial measurement unit (IMU) placed on the subject's foot. The proposed solution is based on double integration and drift cancellation of foot acceleration signals. The method is insensitive to misalignment of IMU axes with respect to foot axes. Details are provided regarding calibration and signal processing procedures. Experimental validation was performed on 10 healthy subjects under three walking conditions: normal, fast and with obstacles. Foot clearance estimation results were compared to measurements from an optical motion capture system. The mean error between them is significantly less than 15 % under the various walking conditions. PMID:26703622

  11. Robust Foot Clearance Estimation Based on the Integration of Foot-Mounted IMU Acceleration Data.

    PubMed

    Benoussaad, Mourad; Sijobert, Benoît; Mombaur, Katja; Coste, Christine Azevedo

    2015-12-23

    This paper introduces a method for the robust estimation of foot clearance during walking, using a single inertial measurement unit (IMU) placed on the subject's foot. The proposed solution is based on double integration and drift cancellation of foot acceleration signals. The method is insensitive to misalignment of IMU axes with respect to foot axes. Details are provided regarding calibration and signal processing procedures. Experimental validation was performed on 10 healthy subjects under three walking conditions: normal, fast and with obstacles. Foot clearance estimation results were compared to measurements from an optical motion capture system. The mean error between them is significantly less than 15 % under the various walking conditions.

  12. Factors associated with spontaneous clearance of hepatitis C virus among illicit drug users

    PubMed Central

    Grebely, Jason; Raffa, Jesse D; Lai, Calvin; Krajden, Mel; Conway, Brian; Tyndall, Mark W

    2007-01-01

    BACKGROUND: Spontaneous clearance of hepatitis C virus (HCV) occurs in approximately 25% of individuals. METHODS: To better understand the characteristics associated with clearance, the present study evaluated HCV clearance in a community-based cohort study. The Community Health and Safety Evaluation project recruited 3553 individuals via community organizations and door-to-door canvassing of a random sample of single occupancy hotels in the community to monitor uptake of health services and to estimate the incidence of communicable infections. Cohort data were linked with longitudinal laboratory databases, including HCV antibody and polymerase chain reaction assay results. RESULTS: Overall, 762 individuals had HCV antibody and RNA testing performed between 1999 and 2005. Spontaneous HCV clearance was observed in 179 individuals (23.5%), while HCV persistence was observed in 583 individuals (76.5%). The ability to develop protective immunity against HCV, as demonstrated by viral clearance, occurred more often in individuals of Aboriginal ethnicity (adjusted OR [AOR] 2.9, 95% CI 2.0 to 4.3; P<0.001) and female individuals (AOR 1.6, 95% CI 1.1 to 2.4; P=0.01). The rate of spontaneous HCV clearance was reduced in individuals using any type of illicit drugs (AOR 0.54, 95% CI 0.29 to 1.00; P=0.05) and those with HIV coinfection (AOR 0.58, 95% CI 0.38 to 0.88; P=0.01). Of 218 HIV-infected subjects, 48 of 51 (94%) in whom the order of HCV and HIV infection was established were infected with HCV a median of 2.4 years (range 0.2 to 10 years) before becoming infected with HIV. CONCLUSIONS: Aboriginal ethnicity and female sex were associated with increased rates of HCV clearance, while HIV coinfection and illicit drug use were associated with increased HCV persistence. PMID:17637948

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

    PubMed Central

    Lindström, Maria; Falk, Rolf; Hjelte, Lena; Philipson, Klas; Svartengren, Magnus

    2006-01-01

    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 < 0.001) in the PCD subjects, 79 % (95% Confidence Interval, 67.6;90.6), compared to 49 % (42.3;55.5) in the healthy controls. There was a significant clearance after 24 h both in the PCD subjects and in the healthy controls with equivalent clearance. The mean Ret24 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. PMID:16712736

  14. Similarity analysis of compressor tip clearance flow structure

    NASA Technical Reports Server (NTRS)

    Chen, G. T.; Greitzer, E. M.; Tan, C. S.; Marble, F. E.

    1991-01-01

    A new approach is presented for analyzing compressor tip clearance flow. The basic idea is that the clearance velocity field can be (approximately) decomposed into independent throughflow and crossflow, since chordwise pressure gradients are much smaller than normal pressure gradients in the clearance region. As in the slender body approximation in external aerodynamics, this description implies that the three-dimensional steady clearance flow can be viewed as a two-dimensional, unsteady flow. Using this approach, a similarity scaling for the crossflow in the clearance region is developed and a generalized description of the clearance vortex is derived. Calculations based on the similarity scaling agree well with a wide range of experimental data in regard to flow features such as crossflow velocity field, static pressure field, and tip clearance vortex trajectory.

  15. Deposition, retention, and clearance of inhaled particles.

    PubMed

    Lippmann, M; Yeates, D B; Albert, R E

    1980-11-01

    The relation between the concentrations and characteristics of air contaminants in the work place and the resultant toxic doses and potential hazards after their inhalation depends greatly on their patterns of deposition and the rates and pathways for their clearance from the deposition sites. The distribution of the deposition sites of inhaled particles is strongly dependent on their aerodynamic diameters. For normal man, inhaled non-hygroscopic particles greater than or equal to 2 micrometers that deposit in the conducting airways by impaction are concentrated on to a small fraction of the surface. Cigarette smoking and bronchitis produce a proximal shift in the deposition pattern. The major factor affecting the deposition of smaller particles is their transfer from tidal to reserve air. For particles soluble in respiratory tract fluid, systemic uptake may be relatively complete for all deposition patterns, and there may be local toxic or irritant effects or both. On the other hand, slowly soluble particles depositing in the conducting airways are carried on the surface to the glottis and are swallowed within one day. Mucociliary transport rates are highly variable, both along the ciliated airways of a given individual and between individuals. The changes in clearance rates produced by drugs, cigarette smoke, and other environmental pollutants can greatly increase or decrease these rates. Particles deposited in non-ciliated airways have large surface-to-volume ratios, and clearance by dissolution can occur for materials generally considered insoluble. They may also be cleared as free particles either by passive transport along surface liquids or, after phagocytosis, by transport within alveolar macrophages. If the particles penetrate the epithelium, either bare or within macrophages, they may be sequestered within cells or enter the lymphatic circulation and be carried to pleural, hilar, and more distant lymph nodes. Non-toxic insoluble particles are cleared from

  16. Deposition, retention, and clearance of inhaled particles.

    PubMed Central

    Lippmann, M; Yeates, D B; Albert, R E

    1980-01-01

    The relation between the concentrations and characteristics of air contaminants in the work place and the resultant toxic doses and potential hazards after their inhalation depends greatly on their patterns of deposition and the rates and pathways for their clearance from the deposition sites. The distribution of the deposition sites of inhaled particles is strongly dependent on their aerodynamic diameters. For normal man, inhaled non-hygroscopic particles greater than or equal to 2 micrometers that deposit in the conducting airways by impaction are concentrated on to a small fraction of the surface. Cigarette smoking and bronchitis produce a proximal shift in the deposition pattern. The major factor affecting the deposition of smaller particles is their transfer from tidal to reserve air. For particles soluble in respiratory tract fluid, systemic uptake may be relatively complete for all deposition patterns, and there may be local toxic or irritant effects or both. On the other hand, slowly soluble particles depositing in the conducting airways are carried on the surface to the glottis and are swallowed within one day. Mucociliary transport rates are highly variable, both along the ciliated airways of a given individual and between individuals. The changes in clearance rates produced by drugs, cigarette smoke, and other environmental pollutants can greatly increase or decrease these rates. Particles deposited in non-ciliated airways have large surface-to-volume ratios, and clearance by dissolution can occur for materials generally considered insoluble. They may also be cleared as free particles either by passive transport along surface liquids or, after phagocytosis, by transport within alveolar macrophages. If the particles penetrate the epithelium, either bare or within macrophages, they may be sequestered within cells or enter the lymphatic circulation and be carried to pleural, hilar, and more distant lymph nodes. Non-toxic insoluble particles are cleared from

  17. Axial compressor blade design for desensitization of aerodynamic performance and stability to tip clearance

    NASA Astrophysics Data System (ADS)

    Erler, Engin

    Tip clearance flow is the flow through the clearance between the rotor blade tip and the shroud of a turbomachine, such as compressors and turbines. This flow is driven by the pressure difference across the blade (aerodynamic loading) in the tip region and is a major source of loss in performance and aerodynamic stability in axial compressors of modern aircraft engines. An increase in tip clearance, either temporary due to differential radial expansion between the blade and the shroud during transient operation or permanent due to engine wear or manufacturing tolerances on small blades, increases tip clearance flow and results in higher fuel consumption and higher risk of engine surge. A compressor design that can reduce the sensitivity of its performance and aerodynamic stability to tip clearance increase would have a major impact on short and long-term engine performance and operating envelope. While much research has been carried out on improving nominal compressor performance, little had been done on desensitization to tip clearance increase beyond isolated observations that certain blade designs such as forward chordwise sweep, seem to be less sensitive to tip clearance size increase. The current project aims to identify through a computational study the flow features and associated mechanisms that reduces sensitivity of axial compressor rotors to tip clearance size and propose blade design strategies that can exploit these results. The methodology starts with the design of a reference conventional axial compressor rotor followed by a parametric study with variations of this reference design through modification of the camber line and of the stacking line of blade profiles along the span. It is noted that a simple desensitization method would be to reduce the aerodynamic loading of the blade tip which would reduce the tip clearance flow and its proportional contribution to performance loss. However, with the larger part of the work on the flow done in this

  18. Lithium clearance in man: effects of dietary salt intake, acute changes in extracellular fluid volume, amiloride and frusemide.

    PubMed

    Atherton, J C; Green, R; Hughes, S; McFall, V; Sharples, J A; Solomon, L R; Wilson, L

    1987-12-01

    1. The effects of amiloride and frusemide on lithium clearance were studied during changes in dietary sodium chloride intake and during infusion of 0.9% NaCl in normal human volunteers. 2. Lithium and fractional lithium clearances were less on the low than on the high salt diet. Values for the medium salt diet were intermediate. Acute extracellular fluid volume expansion with 0.9% NaCl infusion and extracellular fluid volume contraction 3-4 h after intravenous frusemide caused lithium and fractional lithium clearances to increase and decrease respectively. 3. Amiloride caused small changes in lithium and fractional lithium clearances on a low salt diet, but was without effect when salt intake was medium or high. 4. Increases in lithium clearance occurred immediately after frusemide irrespective of dietary salt intake and in subjects infused with 0.9% NaCl. Only in salt-depleted subjects did frusemide cause a substantial increase in fractional lithium clearance. Changes induced under other circumstances were small. 5. It is concluded that the lithium clearance method for assessment of proximal tubule salt and water reabsorption can be used with some degree of confidence in certain circumstances (medium and high salt intake as well as in acute volume expansion) but may not be reliable when dietary salt intake is low. PMID:3690979

  19. The effects of smoking and smoking cessation on nasal mucociliary clearance, mucus properties and inflammation

    PubMed Central

    Utiyama, Daniela Mitiyo Odagiri; Yoshida, Carolina Tieko; Goto, Danielle Miyuki; de Santana Carvalho, Tômas; de Paula Santos, Ubiratan; Koczulla, Andreas Rembert; Saldiva, Paulo Hilário Nascimento; Nakagawa, Naomi Kondo

    2016-01-01

    OBJECTIVE: The aim of the present study was to assess nasal mucociliary clearance, mucus properties and inflammation in smokers and subjects enrolled in a Smoking Cessation Program (referred to as quitters). METHOD: A total of 33 subjects with a median (IQR) smoking history of 34 (20-58) pack years were examined for nasal mucociliary clearance using a saccharine transit test, mucus properties using contact angle and sneeze clearability tests, and quantification of inflammatory and epithelial cells, IL-6 and IL-8 concentrations in nasal lavage fluid. Twenty quitters (mean age: 51 years, 9 male) were assessed at baseline, 1 month, 3 months and 12 months after smoking cessation, and 13 smokers (mean age: 52 years, 6 male) were assessed at baseline and after 12 months. Clinicaltrials.gov: NCT02136550. RESULTS: Smokers and quitters showed similar demographic characteristics and morbidities. At baseline, all subjects showed impaired nasal mucociliary clearance (mean 17.6 min), although 63% and 85% of the quitters demonstrated significant nasal mucociliary clearance improvement at 1 month and 12 months, respectively. At 12 months, quitters also showed mucus sneeze clearability improvement (∼26%), an increased number of macrophages (2-fold) and no changes in mucus contact angle or cytokine concentrations. CONCLUSION: This study showed that smoking cessation induced early improvements in nasal mucociliary clearance independent of mucus properties and inflammation. Changes in mucus properties were observed after only 12 months of smoking cessation. PMID:27438569

  20. A deep sequencing tool for partitioning clearance rates following antimalarial treatment in polyclonal infections

    PubMed Central

    Mideo, Nicole; Bailey, Jeffrey A.; Hathaway, Nicholas J.; Ngasala, Billy; Saunders, David L.; Lon, Chanthap; Kharabora, Oksana; Jamnik, Andrew; Balasubramanian, Sujata; Björkman, Anders; Mårtensson, Andreas; Meshnick, Steven R.; Read, Andrew F.; Juliano, Jonathan J.

    2016-01-01

    Background and objectives: Current tools struggle to detect drug-resistant malaria parasites when infections contain multiple parasite clones, which is the norm in high transmission settings in Africa. Our aim was to develop and apply an approach for detecting resistance that overcomes the challenges of polyclonal infections without requiring a genetic marker for resistance. Methodology: Clinical samples from patients treated with artemisinin combination therapy were collected from Tanzania and Cambodia. By deeply sequencing a hypervariable locus, we quantified the relative abundance of parasite subpopulations (defined by haplotypes of that locus) within infections and revealed evolutionary dynamics during treatment. Slow clearance is a phenotypic, clinical marker of artemisinin resistance; we analyzed variation in clearance rates within infections by fitting parasite clearance curves to subpopulation data. Results: In Tanzania, we found substantial variation in clearance rates within individual patients. Some parasite subpopulations cleared as slowly as resistant parasites observed in Cambodia. We evaluated possible explanations for these data, including resistance to drugs. Assuming slow clearance was a stable phenotype of subpopulations, simulations predicted that modest increases in their frequency could substantially increase time to cure. Conclusions and implications: By characterizing parasite subpopulations within patients, our method can detect rare, slow clearing parasites in vivo whose phenotypic effects would otherwise be masked. Since our approach can be applied to polyclonal infections even when the genetics underlying resistance are unknown, it could aid in monitoring the emergence of artemisinin resistance. Our application to Tanzanian samples uncovers rare subpopulations with worrying phenotypes for closer examination. PMID:26817485

  1. Quantification of clearance and creep in acetabular wear measurements

    PubMed Central

    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

  2. Loss of tubular creatinine secretion as the only sign of tubular proximal cell dysfunction in light chain proximal tubulopathy

    PubMed Central

    Stehlé, Thomas; Vignon, Marguerite; Flamant, Martin; Figueres, Marie-Lucile; Rabant, Marion; Rodenas, Anita; Noël, Laure-Hélène; Arnulf, Bertrand; Vidal-Petiot, Emmanuelle

    2016-01-01

    Abstract Light chain proximal tubulopathy (LCPT) is a rare disease, characterized by cytoplasmic inclusions of light chain (usually kappa) immunoglobulins. Clinical presentation is usually a Fanconi syndrome. The proximal tubular dysfunction can be incomplete, and exceptional cases of LCPT without any tubular dysfunction have even been described. Here, we report a case of LCPT in which the only sign of proximal tubulopathy is the absence of secretion of creatinine, as assessed by the simultaneous measurement of renal clearance of creatinine and 51CrEDTA. The loss of tubular creatinine secretion as a sign of tubular proximal cell dysfunction ought to be identified in patients with light chain proximal tubulopathy as it leads to a clinically relevant underestimation of GFR by the creatinine-derived equations. The prevalence and prognostic significance of this particular proximal tubular damage in LCPT remain to be determined. PMID:27367983

  3. Multiple genetic variants predict steady-state nevirapine clearance in HIV-infected Cambodians

    PubMed Central

    Bertrand, Julie; Chou, Monidarin; Richardson, Danielle M.; Verstuyft, Céline; Leger, Paul D.; Mentré, France; Taburet, Anne-Marie; Haas, David W.

    2013-01-01

    Objective In a previous analysis involving protocol ANRS 12154, interindividual variability in steady-state nevirapine clearance among HIV-infected Cambodians was partially explained by CYP2B6 516G→T (CYP2B6*6). Here, we examine whether additional genetic variants predict nevirapine clearance in this cohort. Methods Analyses included Phnom Penh ESTHER (Ensemble pour une Solidarité Thérapeutique Hospitalière en Réseau) cohort participants who had consented for genetic testing. All participants were receiving nevirapine plus two nucleoside analogs. The mean individual nevirapine clearance estimates were derived from a population model developed on nevirapine concentrations at 18 and 36 months of therapy. Polymorphisms were assayed in ABCB1, CYP2A6, CYP2B6, CYP2C19, CYP3A4, CYP3A5, and NR1I2. Results Of 198 assayed loci, 130 were polymorphic. Among 129 individuals with evaluable genetic data, nevirapine clearance ranged from 1.06 to 5.00 l/h in 128 individuals and was 7.81 l/h in one individual. In bivariate linear regression, CYP2B6 516G→T (CYP2B6*6) was associated with lower nevirapine clearances (P = 3.5 × 10–6). In a multivariate linear regression model conditioned on CYP2B6 516G→T, independent associations were identified with CYP2B6 rs7251950, CYP2B6 rs2279343, and CYP3A4 rs2687116. The CYP3A4 association disappeared after censoring the outlier clearance value. A model that included CYP2B6 516G→T (P = 1.0 × 10–9), rs7251950 (P = 4.8 × 10–5), and rs2279343 (P = 7.1 × 10–5) explained 11% of interindividual variability in nevirapine clearance. Conclusion Among HIV-infected Cambodians, several CYP2B6 polymorphisms were associated independently with steady-state nevirapine clearance. The prediction of nevirapine clearance was improved by considering several polymorphisms in combination. PMID:23104099

  4. Esophageal Acid Clearance During Random Swallowing Is Faster in Patients with Barrett’s Esophagus Than in Healthy Controls

    PubMed Central

    Lottrup, Christian; Krarup, Anne L; Gregersen, Hans; Ejstrud, Per; Drewes, Asbjørn M

    2016-01-01

    Background/Aims Impaired esophageal acid clearance may be a contributing factor in the pathogenesis of Barrett’s esophagus. However, few studies have measured acid clearance as such in these patients. In this explorative, cross-sectional study, we aimed to compare esophageal acid clearance and swallowing rate in patients with Barrett’s esophagus to that in healthy controls. Methods A total of 26 patients with histology-confirmed Barrett’s esophagus and 12 healthy controls underwent (1) upper endoscopy, (2) an acid clearance test using a pH-impedance probe under controlled conditions including controlled and random swallowing, and (3) an ambulatory pH-impedance measurement. Results Compared with controls and when swallowing randomly, patients cleared acid 46% faster (P = 0.008). Furthermore, patients swallowed 60% more frequently (mean swallows/minute: 1.90 ± 0.74 vs 1.19 ± 0.58; P = 0.005), and acid clearance time decreased with greater random swallowing rate (P < 0.001). Swallowing rate increased with lower distal esophageal baseline impedance (P = 0.014). Ambulatory acid exposure was greater in patients (P = 0.033), but clearance times assessed from the ambulatory pH-measurement and acid clearance test were not correlated (all P > 0.3). Conclusions More frequent swallowing and thus faster acid clearance in Barrett’s esophagus may constitute a protective reflex due to impaired mucosal integrity and possibly acid hypersensitivity. Despite these reinforced mechanisms, acid clearance ability seems to be overthrown by repeated, retrograde acid reflux, thus resulting in increased esophageal acid exposure and consequently mucosal changes. PMID:27557545

  5. Effects of passive smoking on theophylline clearance.

    PubMed

    Matsunga, S K; Plezia, P M; Karol, M D; Katz, M D; Camilli, A E; Benowitz, N L

    1989-10-01

    Theophylline disposition was examined in seven passive smokers, defined as nonsmokers with long-term exposure to cigarette smoke, and seven age-matched nonsmokers with minimal smoke exposure. Subjects were given an intravenous infusion of aminophylline (6 mg/kg) and blood samples were drawn before and during the 48-hour postinfusion period. Clearance for passive smokers was 6.01 x 10(-2) L/hr.kg and for nonsmokers, clearance was 4.09 x 10(-2) L/hr.kg (p less than 0.025). Terminal elimination half-life for passive smokers was 6.93 hours versus 8.69 hours for nonsmokers (p less than 0.05). The mean residence time for passive smokers was 9.89 hours. For nonsmokers, the mean residence time was 13.11 hours (p less than 0.05). These measurements were statistically different, whereas there was no difference in volume of distribution between the groups, suggesting that passive smokers metabolize theophylline more rapidly than nonsmokers. Plasma and urine cotinine and nicotine concentrations were measured in all subjects. There was a significant difference between the subject groups in plasma (p less than 0.004) and urine (p less than 0.002) cotinine concentrations. Theophylline clearance correlated with both plasma (r = 0.73, p less than 0.01) and urine (r = 0.79, p less than 0.01) cotinine concentrations. Additional studies should be conducted to further define the pharmacokinetic characteristics of passive smokers and to assess the effects of passive smoking on drugs metabolized by the mixed function oxidase system. PMID:2791443

  6. Amylase creatinine clearance ratio after biliary surgery.

    PubMed

    Donaldson, L A; McIntosh, W; Joffe, S N

    1977-01-01

    The amylase creatinine clearance ratio (ACCR) is considered to be a more sensitive index of acute pancreatitis than the serum amylase level. Serial ACCR estimations were undertaken in 25 patients undergoing an elective cholecystectomy. Using accepted criteria, 28% of these patients developed, in the postoperative period, biochemical evidence of pancreatic gland damage, although the serum amylase level remained normal. This raised ACCR was particularly noted in patients who had undergone an exploration of the common bile duct. The ACCR would appear to be a more sensitive index of pancreatic gland disruption secondary to biliary surgery than the serum amylase level.

  7. Amylase creatinine clearance ratio after biliary surgery.

    PubMed

    Donaldson, L A; McIntosh, W; Joffe, S N

    1977-01-01

    The amylase creatinine clearance ratio (ACCR) is considered to be a more sensitive index of acute pancreatitis than the serum amylase level. Serial ACCR estimations were undertaken in 25 patients undergoing an elective cholecystectomy. Using accepted criteria, 28% of these patients developed, in the postoperative period, biochemical evidence of pancreatic gland damage, although the serum amylase level remained normal. This raised ACCR was particularly noted in patients who had undergone an exploration of the common bile duct. The ACCR would appear to be a more sensitive index of pancreatic gland disruption secondary to biliary surgery than the serum amylase level. PMID:402305

  8. Study of blade clearance effects on centrifugal pumps

    NASA Technical Reports Server (NTRS)

    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.

  9. 76 FR 70460 - Agency Information Collection Activities: Proposed Collection; Comment Request; Generic Clearance...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-14

    ..., but are not statistical surveys that yield quantitative results that can be generalized to the... generic clearance for qualitative information will not be used for quantitative information collections... size, the expected response rate, methods for assessing potential non-response bias, the protocols...

  10. 77 FR 72361 - Agency Information Collection Activities: Proposed Collection; Comment Request; Generic Clearance...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-05

    ..., but are not statistical surveys that yield quantitative results that can be generalized to the... generic clearance for qualitative information will not be used for quantitative information collections... size, the expected response rate, methods for assessing potential non-response bias, the protocols...

  11. 78 FR 74175 - Agency Information Collection Activities: Proposed Collection; Comment Request; Generic Clearance...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-10

    ... and opinions, ] but are not statistical surveys that yield quantitative results that can be... generic clearance for qualitative information will not be used for quantitative information collections... size, the expected response rate, methods for assessing potential non-response bias, the protocols...

  12. Mucociliary clearance following segmental tracheal reversal.

    PubMed

    Delaere, P R; Liu, Z; Delanghe, G; Gyselen, K; Jorissen, M; Feenstra, L

    1996-04-01

    Ciliated tracheal epithelium is arranged in a polarized pattern oriented according to the inferior-superior axis of the trachea and is responsible for the transport of mucus toward the larynx. In this study, ciliary beat orientation and the influence of external factors on mucociliary clearance direction were studied in rabbit inverted cervical tracheas. The animals displayed normal respiration postoperatively. After 16 weeks, airway clearance was studied by observation of the movement of silicone particles placed in the inverted segment and in normal parts of the ciliated epithelium. Cilia exhibited unidirectional and coordinated movement within inverted tracheal segments. As shown by the direction of effective flow produced by beating cilia and by scanning electron microscopy, the cilia in the inverted segment beat in the opposite direction from the cilia in the remainder of the trachea. This study demonstrated that ciliary orientation is irreversibly determined, but the reversal of ciliary beating within the cervical trachea had no adverse effects on the survival of the animals.

  13. Deposition and clearance of inhaled particles.

    PubMed Central

    Stuart, B O

    1984-01-01

    Theoretical models of respiratory tract deposition of inhaled particles are compared to experimental studies of deposition patterns in humans and animals, as governed principally by particle size, density, respiratory rate and flow parameters. Various models of inhaled particle deposition make use of approximations of the respiratory tract to predict fractional deposition caused by fundamental physical processes of particle impaction, sedimentation, and diffusion. These models for both total deposition and regional (nasopharyngeal, tracheobronchial, and pulmonary) deposition are compared with early and recent experimental studies. Reasonable correlation has been obtained between theoretical and experimental studies, but the behavior in the respiratory tract of very fine (less than 0.1 micron) particles requires further investigation. Properties of particle shape, charge and hygroscopicity as well as the degree of respiratory tract pathology also influence deposition patterns; definitive experimental work is needed in these areas. The influence upon deposition patterns of dynamic alterations in inspiratory flow profiles caused by a variety of breathing patterns also requires further study, and the use of differing ventilation techniques with selected inhaled particle sizes holds promise in diagnosis of respiratory tract diseases. Mechanisms of conducting airway and alveolar clearance processes involving the pulmonary macrophage, mucociliary clearance, dissolution, transport to systemic circulation, and translocation via regional lymphatic vessels are discussed. PMID:6376108

  14. Surfactant secretion and clearance in the newborn

    SciTech Connect

    Stevens, P.A.; Wright, J.R.; Clements, J.A. )

    1989-10-01

    Pregnant rabbits (30 days) were injected intravenously with (3H)choline 8 h before delivery. The fetuses were delivered, and lung lavage and lamellar body phospholipids (PL) were analyzed. Some newborns also received radioactively labeled surfactant intratracheally on delivery and were permitted to breathe. With time, intratracheal label decreased in lavage and appeared in the lamellar body fraction, and intravenous label accumulated in both pools. Using a tracer analysis for non-steady state, we calculated surfactant secretion and clearance rates for the newborn period. Before birth, both rates rose slightly from 1.8 micrograms PL.g body wt-1.h-1 at 6 h before birth to 7.3 at birth. Immediately after birth, secretion rate rose to 37.7 micrograms PL.g body wt-1.h-1. Between 1.5 and 2 h after birth it fell to a minimum of 1.8 micrograms PL.g body wt-1.h-1 and then rose slowly to 6.0 at 12 h. After birth, clearance rate increased less than secretion rate (maximum 24.7 micrograms PL.g body wt-1.h-1 shortly after birth) then followed the same pattern but did not balance secretion rate in the 1st day.

  15. Renal Clearance of Mineral Metabolism Biomarkers.

    PubMed

    van Ballegooijen, Adriana J; Rhee, Eugene P; Elmariah, Sammy; de Boer, Ian H; Kestenbaum, Bryan

    2016-02-01

    CKD leads to disturbances in multiple interrelated hormones that regulate bone and mineral metabolism. The renal handling of mineral metabolism hormones in humans is incompletely understood. We determined the single-pass renal clearance of parathyroid hormone, fibroblast growth factor 23, vitamin D metabolites, and phosphate from paired blood samples collected from the abdominal aorta and renal vein in 17 participants undergoing simultaneous right and left heart catheterization and estimated associations of eGFR with the renal elimination of metabolites. The mean age ±SD of the study population was 71.4±10.0 years and 11 participants (65%) were male. We found a relatively large mean±SD single-pass renal extraction of parathyroid hormone (44.2%±10.3%) that exceeded the extraction of creatinine (22.1%±7.9%). The proportionate renal extraction of parathyroid hormone correlated with eGFR. The renal extraction of fibroblast growth factor 23 was, on average, lower than that of parathyroid hormone with greater variability across individuals (17.1%±19.5%). There were no differences in the mean concentrations of vitamin D metabolites across the renal vein and artery. In summary, we demonstrate substantial single-pass renal extraction of parathyroid hormone at a rate that exceeds glomerular filtration. Impaired renal clearance of parathyroid hormone may contribute to secondary hyperparathyroidism in CKD.

  16. Fuel conservation through active control of rotor clearances

    NASA Technical Reports Server (NTRS)

    Beitler, R. S.; Saunders, A. A.; Wanger, R. P.

    1980-01-01

    Under the NASA-sponsored Energy Efficient Engine (EEE) Project, technology is being developed which will significantly reduce the fuel consumption of turbofan engines for subsonic transport aircraft. One technology concept being pursued is active control of rotor tip clearances. Attention is given to rotor tip clearance considerations and an overview of preliminary study results as well as the General Electric EEE clearance control approach is presented. Finally, potential fuel savings with active control of rotor clearances for a typical EEE mission are predicted.

  17. ESR measurement of radical clearance in lung of whole mouse

    SciTech Connect

    Takeshita, K.; Utsumi, H.; Hamada, A. )

    1991-06-14

    Clearance of the nitroxide radicals, hydroxy-TEMPO and carboxy-PROxYL, in whole-mouse lung was directly measured by in vivo ESR. After injecting a nitroxide radical, distribution of the nitroxide radical all over the lung was confirmed by ESR imaging. The ESR signal of hydroxy-TEMPO was reduced in the lung and the clearance obeyed first-order kinetics, whereas the signal of carboxy-PROxYL remained constant. Comparison of the clearance rates of live and dead mice indicated the presence of 2 different clearance systems in the lung: loss of its paramagnetism in the lung, and transfer from alveolar to the blood circulation system.

  18. Demographics, socio-behavioral factors, and drug use patterns: what matters in spontaneous HCV clearance?

    PubMed

    Shah, Dimpy P; Grimes, Carolyn Z; Brown, Eric; Hwang, Lu-Yu

    2012-02-01

    Hepatitis C virus (HCV), an emerging bloodborne pathogen, causes chronic liver disease frequently except in about 10-20% of infections which undergo spontaneous resolution. Investigating factors that influence viral clearance is essential to understand the natural history of this infection and establishing novel strategies for prevention and treatment. HCV clearance was estimated in a unique cohort of 1,260 HIV and HBV negative current drug users enrolled for a hepatitis B vaccination study. It was defined as the inability to detect viral RNA using a PCR method in presence of serum anti-HCV antibody EIA. Associated demographic and socio-behavioral factors including drug use patterns were identified from the enrolled subjects using multivariate regression analysis. 33.3% (420/1260) of drug users were found positive for anti-HCV antibodies and 14.8% (62/420) of these individuals achieved viral clearance (negative PCR test). Race or ethnicity of the participants was the only significant factor associated with HCV clearance. Hispanics (OR = 3.4, 95% CI: 1.3-8.5, P = 0.01) and Caucasians (OR = 3.1, 95% CI: 1.5-6.6, P = 0.003) had significantly higher odds of clearing the virus compared to African Americans when adjusted for age and gender. None of the socio-behavioral factors including alcohol intake and drug use patterns were significant determinants of HCV clearance. Racial or ethnic differences in HCV clearance were observed in this study suggesting an important role of host genetic susceptibility factors in determining the clinical course of this disease. Further research is needed to examine these genetic associations of host-virus relationships. PMID:22170543

  19. Systematic evaluation of validated type 2 diabetes and glycaemic trait loci for association with insulin clearance

    PubMed Central

    Guo, X.; Cui, J.; Jones, M. R.; Haritunians, T.; Xiang, A. H.; Chen, Y.-D. I.; Taylor, K. D.; Buchanan, T. A.; Hsueh, W. A.; Raffel, L. J.; Rotter, J. I.

    2013-01-01

    Aims/hypothesis Insulin clearance is a highly heritable trait, for which few quantitative trait loci have been discovered. We sought to determine whether validated type 2 diabetes and/or glycaemic trait loci are associated with insulin clearance. Methods Hyperinsulinaemic–euglycaemic clamps were performed in two Hispanic-American family cohorts totalling 1329 participants in 329 families. The Metabochip was used to fine-map about 50 previously identified loci for type 2 diabetes, fasting glucose, fasting insulin, 2 h glucose or HbA1c. This resulted in 17,930 variants, which were tested for association with clamp-derived insulin clearance via meta-analysis of the two cohorts. Results In the meta-analysis, 38 variants located within seven loci demonstrated association with insulin clearance (p < 0.001). The top signals for each locus were rs10241087 (DGKB/TMEM195 [TMEM195 also known as AGMO]) (p = 4.4 × 10−5); chr1:217605433 (LYPLAL1) (p = 3.25 × 10−4); rs2380949 (GLIS3) (p = 3.4 × 10−4); rs55903902 (FADS1) (p = 5.6 × 10−4); rs849334 (JAZF1) (p = 6.4 × 10−4); rs35749 (IGF1) (p = 6.7 × 10−4); and rs9460557 (CDKAL1) (p = 6.8 × 10−4). Conclusions/interpretation While the majority of validated loci for type 2 diabetes and related traits do not appear to influence insulin clearance in Hispanics, several of these loci do show evidence of association with this trait. It is therefore possible that these loci could have pleiotropic effects on insulin secretion, insulin sensitivity and insulin clearance. PMID:23494448

  20. Demographics, Socio-behavioral Factors and Drug Use Patterns: What Matters in Spontaneous HCV Clearance?

    PubMed Central

    Shah, Dimpy P.; Grimes, Carolyn Z.; Brown, Eric; Hwang, Lu-Yu

    2011-01-01

    Hepatitis C virus (HCV), an emerging bloodborne pathogen, causes chronic liver disease frequently except in about 10-20% of infections which undergo spontaneous resolution. Investigating factors that influence viral clearance is essential to understand the natural history of this infection and establishing novel strategies for prevention and treatment. HCV clearance was estimated in a unique cohort of 1260 HIV and HBV negative current drug users enrolled for a hepatitis B vaccination study. It was defined as the inability to detect viral RNA using a PCR method in presence of serum anti-HCV antibody EIA. Associated demographic and socio-behavioral factors including drug use patterns were identified from the enrolled subjects using multivariate regression analysis. 33.3 % (420/1260) of drug users were found positive for anti-HCV antibodies and 14.8% (62/420) of these individuals achieved viral clearance (negative PCR test). Race or ethnicity of the participants was the only significant factor associated with HCV clearance. Hispanics (OR = 3.4, 95% CI: 1.3-8.5, p = 0.01) and Caucasians (OR = 3.1, 95% CI: 1.5-6.6, p = 0.003) had significantly higher odds of clearing the virus compared to African Americans when adjusted for age and gender. None of the socio-behavioral factors including alcohol intake and drug use patterns were significant determinants of HCV clearance. Racial or ethnic differences in HCV clearance were observed in this study suggesting an important role of host genetic susceptibility factors in determining the clinical course of this disease. Further research is needed to examine these genetic associations of host-virus relationships. PMID:22170543

  1. Dynamic analysis for planar beam with clearance joint

    NASA Astrophysics Data System (ADS)

    Yao, XiaoGuang; Guo, XiaoSong; Feng, YongBao; Yu, ChuanQiang; Ma, Changlin

    2015-03-01

    An analytical model was presented in this study to describe the dynamic characteristics of a planar rotation beam with clearance joint. The spherical contact model was introduced to calculate the collision forces for the planar revolute joint. Unlike previous research, to acquire an accurate and convergent solution, the second-order coupling term of the beam axial deformation is taken into account. Then, the flexible beam was divided into discrete elements via the finite element method. The dynamic equations of the model were deduced via the Hamilton's principle. Further, the dynamic responses were obtained and analyzed in the non-inertial and inertial coordinates. To prove the validity of the presented methodology, a virtual prototype model with identical conditions was created in ADAMS. A numerical example was simultaneously calculated by the two different approaches. Comparison of the results shows that the two approaches match quite well. Finally, some valuable conclusions describing the inner-joint collision process are extracted and summarized.

  2. Clearance rates of ephyrae and small medusae of the common jellyfish Aurelia aurita offered different types of prey

    NASA Astrophysics Data System (ADS)

    Riisgård, Hans Ulrik; Madsen, Caroline V.

    2011-01-01

    Prey selection and knowledge of the amounts of water processed by the early stages of the common jellyfish Aurelia aurita may at certain times of the year be crucial for understanding the plankton dynamics in marine ecosystems with mass occurrences of this jellyfish. In the present study we used two different methods ("clearance method" and "ingestion-rate method") to estimate the amount of water cleared per unit of time of different types and sizes of prey organisms offered to A. aurita ephyrae and small medusae. The mean clearance rates of medusae, estimated with Artemia sp. nauplii as prey by both methods, agreed well, namely 3.8 ± 1.4 l h - 1 by the clearance method and 3.2 ± 1.1 l h - 1 by the ingestion-rate method. Both methods showed that copepods (nauplii and adults) and mussel veligers are captured with considerably lower efficiency, 22 to 37% and 14 to 30%, respectively, than Artemia salina nauplii. By contrast, the water processing rates of ephyrae measured by the clearance method with A. salina nauplii as prey were 3 to 5 times lower than those measured by the ingestion-rate method. This indicates that the prerequisite of full mixing for using the clearance method may not have been fulfilled in the ephyrae experiments. The study demonstrates that the predation impact of the young stages of A. aurita is strongly dependent on its developmental stage (ephyra versus medusa), and the types and sizes of prey organisms. The estimated prey-digestion time of 1.3 h in a steady-state feeding experiment with constant prey concentration supports the reliability of the ingestion-rate method, which eliminates the negative "container effects" of the clearance method, and it seems to be useful in future jellyfish studies, especially on small species/younger stages in which both type and number of prey can be easily and precisely assessed.

  3. CYP1A2 polymorphism and theophylline clearance in Korean non-smoking asthmatics

    PubMed Central

    Yim, Eun-Young; Kang, Hye-Ryun; Jung, Jae-Woo; Sohn, Seong-Wook

    2013-01-01

    Background Theophylline is mainly metabolized by cytochrome P450 (CYP) 1A2 and CYP2E1 which show inter-individual variations. However, the underlying mechanism remains unknown in humans. We investigated the relationship between differences in theophylline clearance and genetic polymorphisms in the CYP1A2 and CYP2E1 gene in 89 Korean asthmatic patients. Methods Polymerase chain reaction (PCR) was performed on the 5'-flanking region of those genes. PCR products were directly sequenced and confirmed using the SNaP shot method. We determined whether the detected SNPs affected gene transcription using electrophoretic mobility shift assay (EMSA). Theophylline clearance (mL/kg/h) was assessed by using a Bayesian approach. Results Genetic polymorphisms were identified at 7 sites in the CYP1A2 gene and at 10 sites in the CYP2E1. Among them, subjects with genotypes (GA+AA) of the -3860G>A polymorphism were found to show higher theophylline clearance than those with genotypes GG (29.11 ± 0.91 mL/kg/h vs. 26.12 ± 0.80 mL/kg/h, p = 0.014). This polymorphic site was revealed to be a protein binding site by conducting EMSA on nuclear hepatocyte extracts. Conclusion In conclusion, increased theophylline clearance was significantly related to the -3860G>A polymorphism, which could be associated with increased CYP1A2 inducibility in Korean non-smoking asthmatics. PMID:24260728

  4. Hydrogen clearance: Assessment of technique for measurement of skin-flap blood flow in pigs

    SciTech Connect

    Thomson, J.G.; Kerrigan, C.L. )

    1991-10-01

    The hydrogen clearance technique has been used for many years by investigators to determine brain blood flow and has been partially validated in this setting using other methods of blood flow measurement. The method has been modified to allow blood flow measurements in skin, but the accuracy of H2 clearance for measuring skin blood flow has not been determined. Multiple blood flow measurements were performed using H2 clearance and radioactive microspheres on skin flaps and control skin in pigs. On 12 pigs, a total of 117 flap and 42 control skin measurements were available for analysis. There was no significant difference between the two techniques in measuring mean control skin blood flow. In skin flaps, H2 clearance was significantly correlated to microsphere-measured blood flow, but it consistently gave an overestimate. Sources of error may include injury to the tissues by insertion of electrodes, consumption of H2 by the electrodes, or diffusion of H2 from the relatively ischemic flap to its well-vascularized bed. Further studies are necessary to determine the cause of this error and to measure the technique's accuracy in skeletal muscle and other flaps.

  5. Lung clearance index in the assessment of airways disease.

    PubMed

    Horsley, Alex

    2009-06-01

    In the last few years there has been a growing interest in lung clearance index (LCI), a measure of lung physiology derived from multiple breath washout tests. This resurgence of interest was initially driven by the recognition that such assessments were capable of detecting early airways disease in children, and are more sensitive and easier to perform in this population than conventional lung function tests [Aurora P, Kozlowska W, Stocks J. Gas mixing efficiency from birth to adulthood measured by multiple-breath washout. Respir Physiol Neurobiol, 2005;148(1-2):125-39]. With an appreciation of the importance of earlier identification of airways dysfunction, and prevention of irreversible structural airway changes, methods of following airways disease in these "silent years" are especially important. LCI has now been reported in studies involving all age groups, from infants to adults [Lum S, Gustafsson P, Ljungberg H, Hulskamp G, Bush A, Carr SB, et al. Early detection of cystic fibrosis lung disease: multiple-breath washout versus raised volume tests. Thorax, 2007;62(4):341-7; Horsley AR, Gustafsson PM, Macleod K, Saunders CJ, Greening AP, Porteous D, et al. Lung clearance index is a sensitive, repeatable and practical measure of airways disease in adults with cystic fibrosis. Thorax, 2008;63:135-40], and has a narrow range of normal over this wide age range, making it especially suitable for long-term follow-up studies. In cystic fibrosis (CF) particularly, there is a pressing need for sensitive and repeatable clinical endpoints for therapeutic interventions [Rosenfeld M. An overview of endpoints for cystic fibrosis clinical trials: one size does not fit all. Proc Am Thorac Soc, 2007;4(4):299-301], and LCI has been proposed as an outcome measure in future CF gene therapy studies [Davies JC, Cunningham S, Alton EW, Innes JA. Lung clearance index in CF: a sensitive marker of lung disease severity. Thorax, 2008;63(2):96-7]. This review will consider how LCI is

  6. Spontaneous Clearance of Hepatitis C Virus during Pregnancy

    PubMed Central

    Clohessy, Penelope; Polis, Suzanne; Post, Jeffrey

    2013-01-01

    Spontaneous clearance of hepatitis C virus (HCV) is expected to be unlikely in pregnancy due to the relative immunosuppression and increase in viraemia that occurs. We report the first case of spontaneous clearance of hepatitis C virus (HCV) occurring in pregnancy. PMID:27757149

  7. 10 CFR 706.13 - Clearance of counsel.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Clearance of counsel. 706.13 Section 706.13 Energy DEPARTMENT OF ENERGY SECURITY POLICIES AND PRACTICES RELATING TO LABOR-MANAGEMENT RELATIONS Security Policies and Procedures in National Labor Relations Board Proceedings § 706.13 Clearance of counsel. It...

  8. 10 CFR 706.13 - Clearance of counsel.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Clearance of counsel. 706.13 Section 706.13 Energy DEPARTMENT OF ENERGY SECURITY POLICIES AND PRACTICES RELATING TO LABOR-MANAGEMENT RELATIONS Security Policies and Procedures in National Labor Relations Board Proceedings § 706.13 Clearance of counsel. It...

  9. 10 CFR 706.31 - Clearance of conciliators and arbitrators.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Clearance of conciliators and arbitrators. 706.31 Section 706.31 Energy DEPARTMENT OF ENERGY SECURITY POLICIES AND PRACTICES RELATING TO LABOR-MANAGEMENT RELATIONS Contract Negotiation and Administration § 706.31 Clearance of conciliators and...

  10. 10 CFR 706.13 - Clearance of counsel.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Clearance of counsel. 706.13 Section 706.13 Energy DEPARTMENT OF ENERGY SECURITY POLICIES AND PRACTICES RELATING TO LABOR-MANAGEMENT RELATIONS Security Policies and Procedures in National Labor Relations Board Proceedings § 706.13 Clearance of counsel. It...

  11. 10 CFR 706.31 - Clearance of conciliators and arbitrators.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Clearance of conciliators and arbitrators. 706.31 Section 706.31 Energy DEPARTMENT OF ENERGY SECURITY POLICIES AND PRACTICES RELATING TO LABOR-MANAGEMENT RELATIONS Contract Negotiation and Administration § 706.31 Clearance of conciliators and...

  12. 10 CFR 706.13 - Clearance of counsel.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Clearance of counsel. 706.13 Section 706.13 Energy DEPARTMENT OF ENERGY SECURITY POLICIES AND PRACTICES RELATING TO LABOR-MANAGEMENT RELATIONS Security Policies and Procedures in National Labor Relations Board Proceedings § 706.13 Clearance of counsel. It...

  13. 10 CFR 706.31 - Clearance of conciliators and arbitrators.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Clearance of conciliators and arbitrators. 706.31 Section 706.31 Energy DEPARTMENT OF ENERGY SECURITY POLICIES AND PRACTICES RELATING TO LABOR-MANAGEMENT RELATIONS Contract Negotiation and Administration § 706.31 Clearance of conciliators and...

  14. 10 CFR 706.31 - Clearance of conciliators and arbitrators.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Clearance of conciliators and arbitrators. 706.31 Section 706.31 Energy DEPARTMENT OF ENERGY SECURITY POLICIES AND PRACTICES RELATING TO LABOR-MANAGEMENT RELATIONS Contract Negotiation and Administration § 706.31 Clearance of conciliators and...

  15. 10 CFR 706.13 - Clearance of counsel.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Clearance of counsel. 706.13 Section 706.13 Energy DEPARTMENT OF ENERGY SECURITY POLICIES AND PRACTICES RELATING TO LABOR-MANAGEMENT RELATIONS Security Policies and Procedures in National Labor Relations Board Proceedings § 706.13 Clearance of counsel. It...

  16. Land clearance in the irish neolithic: new evidence and interpretation.

    PubMed

    Pilcher, J R; Smith, A G; Pearson, G W; Crowder, A

    1971-05-01

    Time scales are derived, from radiocarbon dating of pollen diagrams, for Neolithic land clearance at three Irish sites. Three stages are distinguished beginning in the 4th millennium B.C.: stage A, clearance and farming (possibly arable), 100 to 400 years; stage B, farming (possibly pastoral), 150 to 200 years; and stage C, forest regeneration, 50 to 100 years.

  17. Study of global operational needs for mine clearance equipment

    NASA Astrophysics Data System (ADS)

    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.

  18. 33 CFR 118.160 - Vertical clearance gauges.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Vertical clearance gauges. 118.160 Section 118.160 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.160 Vertical clearance gauges. (a) When necessary...

  19. 32 CFR 644.521 - Limitations on clearance cost.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 4 2011-07-01 2011-07-01 false Limitations on clearance cost. 644.521 Section 644.521 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL PROPERTY REAL ESTATE HANDBOOK Disposal Clearance of Explosive Hazards and Other Contamination from...

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

    Code of Federal Regulations, 2010 CFR

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

    Code of Federal Regulations, 2010 CFR

    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...

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

    Code of Federal Regulations, 2010 CFR

    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...

  3. 48 CFR 32.502-2 - Contract finance office clearance.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 1 2013-10-01 2013-10-01 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...

  4. 48 CFR 1432.502-2 - Contract finance office clearance.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 5 2013-10-01 2013-10-01 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...

  5. 48 CFR 1432.502-2 - Contract finance office clearance.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 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...

  6. 48 CFR 1432.502-2 - Contract finance office clearance.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 5 2012-10-01 2012-10-01 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...

  7. 48 CFR 832.502-2 - Contract finance office clearance.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 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...

  8. 48 CFR 32.502-2 - Contract finance office clearance.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 1 2012-10-01 2012-10-01 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...

  9. 48 CFR 832.502-2 - Contract finance office clearance.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 5 2012-10-01 2012-10-01 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...

  10. 48 CFR 32.502-2 - Contract finance office clearance.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 1 2014-10-01 2014-10-01 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...

  11. 48 CFR 832.502-2 - Contract finance office clearance.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 5 2013-10-01 2013-10-01 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...

  12. 76 FR 17615 - Highway-Rail Grade Crossing; Safe Clearance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-30

    ... Crossing; Safe Clearance Notice of Proposed Rulemaking, which was published on January 28, 2011 (76 FR 5120... Parts 177 and 392 RIN 2137-AE69 & 2126-AB04 Highway-Rail Grade Crossing; Safe Clearance AGENCY: Pipeline... that PHMSA and FMCSA extend the comment period for the Highway-Rail Grade Crossing; Safe...

  13. 48 CFR 945.670-1 - Plant clearance function.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false Plant clearance function. 945.670-1 Section 945.670-1 Federal Acquisition Regulations System DEPARTMENT OF ENERGY CONTRACT MANAGEMENT GOVERNMENT PROPERTY Reporting, Reutilization, and Disposal 945.670-1 Plant clearance function....

  14. 48 CFR 32.502-2 - Contract finance office clearance.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 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...

  15. 48 CFR 1432.502-2 - Contract finance office clearance.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 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...

  16. 48 CFR 832.502-2 - Contract finance office clearance.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 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...

  17. 32 CFR 644.522 - Clearance of military scrap.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 4 2014-07-01 2013-07-01 true Clearance of military scrap. 644.522 Section 644... Excess Land and Improvements § 644.522 Clearance of military scrap. Military scrap can contain or be... destruction, by using command, of all military scrap and scrap metal from lands suitable for cultivation...

  18. 32 CFR 644.522 - Clearance of military scrap.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 4 2013-07-01 2013-07-01 false Clearance of military scrap. 644.522 Section 644... Excess Land and Improvements § 644.522 Clearance of military scrap. Military scrap can contain or be... destruction, by using command, of all military scrap and scrap metal from lands suitable for cultivation...

  19. 32 CFR 644.522 - Clearance of military scrap.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 4 2012-07-01 2011-07-01 true Clearance of military scrap. 644.522 Section 644... Excess Land and Improvements § 644.522 Clearance of military scrap. Military scrap can contain or be... destruction, by using command, of all military scrap and scrap metal from lands suitable for cultivation...

  20. 32 CFR 644.516 - Clearance of Air Force lands.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 4 2011-07-01 2011-07-01 false Clearance of Air Force lands. 644.516 Section... Excess Land and Improvements § 644.516 Clearance of Air Force lands. The Chief of Engineers has no responsibility for inspecting or clearing excess Air Force land of explosives or chemical/biological...

  1. 32 CFR 644.521 - Limitations on clearance cost.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Limitations on clearance cost. 644.521 Section 644.521 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL PROPERTY REAL ESTATE HANDBOOK Disposal Clearance of Explosive Hazards and Other Contamination from...

  2. 32 CFR 644.527 - Recording Statements of Clearance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Recording Statements of Clearance. 644.527 Section 644.527 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL PROPERTY REAL ESTATE HANDBOOK Disposal Clearance of Explosive Hazards and Other Contamination from...

  3. 24 CFR 3285.305 - Clearance under homes.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 5 2014-04-01 2014-04-01 false Clearance under homes. 3285.305 Section 3285.305 Housing and Urban Development Regulations Relating to Housing and Urban Development... URBAN DEVELOPMENT MODEL MANUFACTURED HOME INSTALLATION STANDARDS Foundations § 3285.305 Clearance...

  4. 20 CFR 655.150 - Interstate clearance of job order.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Interstate clearance of job order. 655.150... job order. (a) SWA posts in interstate clearance system. The SWA must promptly place the job order in... transmit a copy of its active job order to all States listed in the job order as anticipated...

  5. 20 CFR 655.150 - Interstate clearance of job order.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 3 2014-04-01 2014-04-01 false Interstate clearance of job order. 655.150... job order. (a) SWA posts in interstate clearance system. The SWA must promptly place the job order in... transmit a copy of its active job order to all States listed in the job order as anticipated...

  6. 20 CFR 655.150 - Interstate clearance of job order.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 3 2012-04-01 2012-04-01 false Interstate clearance of job order. 655.150... job order. (a) SWA posts in interstate clearance system. The SWA must promptly place the job order in... transmit a copy of its active job order to all States listed in the job order as anticipated...

  7. 20 CFR 655.150 - Interstate clearance of job order.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Interstate clearance of job order. 655.150... job order. (a) SWA posts in interstate clearance system. The SWA must promptly place the job order in... transmit a copy of its active job order to all States listed in the job order as anticipated...

  8. 20 CFR 655.150 - Interstate clearance of job order.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 3 2013-04-01 2013-04-01 false Interstate clearance of job order. 655.150... job order. (a) SWA posts in interstate clearance system. The SWA must promptly place the job order in... transmit a copy of its active job order to all States listed in the job order as anticipated...

  9. 14 CFR 93.311 - Minimum terrain clearance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Minimum terrain clearance. 93.311 Section... of Grand Canyon National Park, AZ § 93.311 Minimum terrain clearance. Except in an emergency, when... a purpose listed in § 93.309(c), no person may operate an aircraft within 500 feet of any terrain...

  10. 14 CFR 93.311 - Minimum terrain clearance.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Minimum terrain clearance. 93.311 Section... of Grand Canyon National Park, AZ § 93.311 Minimum terrain clearance. Except in an emergency, when... a purpose listed in § 93.309(c), no person may operate an aircraft within 500 feet of any terrain...

  11. 14 CFR 93.311 - Minimum terrain clearance.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Minimum terrain clearance. 93.311 Section... of Grand Canyon National Park, AZ § 93.311 Minimum terrain clearance. Except in an emergency, when... a purpose listed in § 93.309(c), no person may operate an aircraft within 500 feet of any terrain...

  12. 14 CFR 93.311 - Minimum terrain clearance.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Minimum terrain clearance. 93.311 Section... of Grand Canyon National Park, AZ § 93.311 Minimum terrain clearance. Except in an emergency, when... a purpose listed in § 93.309(c), no person may operate an aircraft within 500 feet of any terrain...

  13. 14 CFR 93.311 - Minimum terrain clearance.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Minimum terrain clearance. 93.311 Section... of Grand Canyon National Park, AZ § 93.311 Minimum terrain clearance. Except in an emergency, when... a purpose listed in § 93.309(c), no person may operate an aircraft within 500 feet of any terrain...

  14. 49 CFR 229.71 - Clearance above top of rail.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Clearance above top of rail. 229.71 Section 229.71....71 Clearance above top of rail. No part or appliance of a locomotive except the wheels, flexible nonmetallic sand pipe extension tips, and trip cock arms may be less than 21/2 inches above the top of rail....

  15. 49 CFR 229.71 - Clearance above top of rail.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Clearance above top of rail. 229.71 Section 229.71....71 Clearance above top of rail. No part or appliance of a locomotive except the wheels, flexible nonmetallic sand pipe extension tips, and trip cock arms may be less than 21/2 inches above the top of rail....

  16. 49 CFR 229.71 - Clearance above top of rail.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Clearance above top of rail. 229.71 Section 229.71....71 Clearance above top of rail. No part or appliance of a locomotive except the wheels, flexible nonmetallic sand pipe extension tips, and trip cock arms may be less than 21/2 inches above the top of rail....

  17. 49 CFR 229.71 - Clearance above top of rail.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Clearance above top of rail. 229.71 Section 229.71....71 Clearance above top of rail. No part or appliance of a locomotive except the wheels, flexible nonmetallic sand pipe extension tips, and trip cock arms may be less than 21/2 inches above the top of rail....

  18. 32 CFR 644.516 - Clearance of Air Force lands.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 4 2014-07-01 2013-07-01 true Clearance of Air Force lands. 644.516 Section 644... Excess Land and Improvements § 644.516 Clearance of Air Force lands. The Chief of Engineers has no responsibility for inspecting or clearing excess Air Force land of explosives or chemical/biological...

  19. 32 CFR 644.516 - Clearance of Air Force lands.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 4 2012-07-01 2011-07-01 true Clearance of Air Force lands. 644.516 Section 644... Excess Land and Improvements § 644.516 Clearance of Air Force lands. The Chief of Engineers has no responsibility for inspecting or clearing excess Air Force land of explosives or chemical/biological...

  20. 32 CFR 644.516 - Clearance of Air Force lands.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 4 2013-07-01 2013-07-01 false Clearance of Air Force lands. 644.516 Section... Excess Land and Improvements § 644.516 Clearance of Air Force lands. The Chief of Engineers has no responsibility for inspecting or clearing excess Air Force land of explosives or chemical/biological...

  1. 32 CFR 644.522 - Clearance of military scrap.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Clearance of military scrap. 644.522 Section 644... Excess Land and Improvements § 644.522 Clearance of military scrap. Military scrap can contain or be... determining whether scrap metal will be removed should be the safety of persons coming on the land in...

  2. Do dialysate conductivity measurements provide conductivity clearance or ionic dialysance?

    PubMed

    Petitclerc, T

    2006-11-01

    Dialysate conductivity measurements allow on-line estimation of urea clearance during hemodialysis session. Conductivity measurements provide a value of 'conductivity clearance' for some authors, but a value of 'ionic dialysance' for others. This paper aims at explaining which term should be the more appropriate. Clearance is a parameter defined for measuring the power of a mechanism, which aims at 'clearing' a solution by depurating some solutes. In hemodialysis, clearance measures the efficacy of patient's depuration. In contrast, dialysance measures the capability of transferring solutes between blood and dialysate. The conventional definition of dialysance, requiring the absence of convective transfer, should be generalized to the case of the usual presence of ultrafiltration during the hemodialysis session. For a solute (as urea) absent from the dialysate delivered to the dialyzer inlet, the clearance is equal to its dialysance. In order to avoid a dramatic fall in ionic concentrations during hemodialysis treatment, the clearance of ions is reduced by adding these ions in the dialysate and becomes lower than their dialysance. Conductivity measurements provide a value of electrolytes dialysance. Thus the term of 'ionic dialysance' is more appropriate than the term of 'conductivity clearance'. Nevertheless ionic dialysance represents a good estimation of urea clearance.

  3. Allometric scaling for predicting human clearance of bisphenol A

    SciTech Connect

    Collet, Séverine H. Picard-Hagen, Nicole Lacroix, Marlène Z. Puel, Sylvie Viguié, Catherine Bousquet-Melou, Alain Toutain, Pierre-Louis Gayrard, Véronique

    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.

  4. Clearance systems in the brain—implications for Alzheimer disease

    PubMed Central

    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.

    2015-01-01

    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

  5. 32 CFR 644.521 - Limitations on clearance cost.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 4 2014-07-01 2013-07-01 true Limitations on clearance cost. 644.521 Section 644.521 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL PROPERTY REAL ESTATE HANDBOOK Disposal Clearance of Explosive Hazards and Other Contamination from...

  6. 32 CFR 644.521 - Limitations on clearance cost.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 4 2013-07-01 2013-07-01 false Limitations on clearance cost. 644.521 Section 644.521 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL PROPERTY REAL ESTATE HANDBOOK Disposal Clearance of Explosive Hazards and Other Contamination from...

  7. 32 CFR 644.521 - Limitations on clearance cost.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 4 2012-07-01 2011-07-01 true Limitations on clearance cost. 644.521 Section 644.521 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL PROPERTY REAL ESTATE HANDBOOK Disposal Clearance of Explosive Hazards and Other Contamination from...

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

    NASA Astrophysics Data System (ADS)

    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.

  9. A model of clearance rate regulation in mussels

    NASA Astrophysics Data System (ADS)

    Fréchette, Marcel

    2012-10-01

    Clearance rate regulation has been modelled as an instantaneous response to food availability, independent of the internal state of the animals. This view is incompatible with latent effects during ontogeny and phenotypic flexibility in clearance rate. Internal-state regulation of clearance rate is required to account for these patterns. Here I develop a model of internal-state based regulation of clearance rate. External factors such as suspended sediments are included in the model. To assess the relative merits of instantaneous regulation and internal-state regulation, I modelled blue mussel clearance rate and growth using a DEB model. In the usual standard feeding module, feeding is governed by a Holling's Type II response to food concentration. In the internal-state feeding module, gill ciliary activity and thus clearance rate are driven by internal reserve level. Factors such as suspended sediments were not included in the simulations. The two feeding modules were compared on the basis of their ability to capture the impact of latent effects, of environmental heterogeneity in food abundance and of physiological flexibility on clearance rate and individual growth. The Holling feeding module was unable to capture the effect of any of these sources of variability. In contrast, the internal-state feeding module did so without any modification or ad hoc calibration. Latent effects, however, appeared transient. With simple annual variability in temperature and food concentration, the relationship between clearance rate and food availability predicted by the internal-state feeding module was quite similar to that observed in Norwegian fjords. I conclude that in contrast with the usual Holling feeding module, internal-state regulation of clearance rate is consistent with well-documented growth and clearance rate patterns.

  10. 78 FR 40729 - Agency Information Collection Activities; Proposed Collection; Comment Request: Generic Clearance...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-08

    ...: Generic Clearance for the Collection of Qualitative Feedback on Agency Service Delivery AGENCY: Washington... Information Collection Request (Generic ICR): ``Generic Clearance for the Collection of Qualitative Feedback... Clearance for the Collection of Qualitative Feedback on Agency Service Delivery Abstract: The...

  11. A Study on the Requirements for Fast Active Turbine Tip Clearance Control Systems

    NASA Technical Reports Server (NTRS)

    DeCastro, Jonathan A.; Melcher, Kevin J.

    2004-01-01

    This paper addresses the requirements of a control system for active turbine tip clearance control in a generic commercial turbofan engine through design and analysis. The control objective is to articulate the shroud in the high pressure turbine section in order to maintain a certain clearance set point given several possible engine transient events. The system must also exhibit reasonable robustness to modeling uncertainties and reasonable noise rejection properties. Two actuators were chosen to fulfill such a requirement, both of which possess different levels of technological readiness: electrohydraulic servovalves and piezoelectric stacks. Identification of design constraints, desired actuator parameters, and actuator limitations are addressed in depth; all of which are intimately tied with the hardware and controller design process. Analytical demonstrations of the performance and robustness characteristics of the two axisymmetric LQG clearance control systems are presented. Takeoff simulation results show that both actuators are capable of maintaining the clearance within acceptable bounds and demonstrate robustness to parameter uncertainty. The present model-based control strategy was employed to demonstrate the tradeoff between performance, control effort, and robustness and to implement optimal state estimation in a noisy engine environment with intent to eliminate ad hoc methods for designing reliable control systems.

  12. Hepatectomy Based on Future Liver Remnant Plasma Clearance Rate of Indocyanine Green.

    PubMed

    Uchida, Yuichiro; Furuyama, Hiroaki; Yasukawa, Daiki; Nishino, Hiroto; Ando, Yasuhisa; Hata, Toshiyuki; Machimoto, Takafumi; Yoshimura, Tsunehiro

    2016-01-01

    Background. Hepatectomy, an important treatment modality for liver malignancies, has high perioperative morbidity and mortality rates. Safe, comprehensive criteria for selecting patients for hepatectomy are needed. Since June 2011, we have used a cut-off value of ≧ 0.05 for future liver remnant plasma clearance rate of indocyanine green as a criterion for hepatectomy. The aim of this study was to verify the validity of this criterion. Methods. From June 2011 to December 2015, 212 hepatectomies were performed in Tenri Yorozu Hospital. Of these 212 patients, 107 who underwent preoperative computed tomography imaging volumetry, indocyanine green clearance test, and hepatectomy (excluding partial resection or enucleation) were retrospectively analyzed. Results. There was no postoperative mortality. Posthepatectomy liver failure occurred in 59 patients (55.1%) (International Study Group of Liver Surgery Grade A: 43 cases (40.2%), Grade B: 16 cases (15.0%), and Grade C: no cases). Operative morbidity greater than Clavien-Dindo Grade 3 occurred in 23 patients (21.5%). A low future liver remnant plasma clearance rate of indocyanine green was a good predictor for Grade B cases (area under curve = 0.804; 95% confidence interval, 0.712-0.895). Conclusion. Liver remnant plasma clearance rate of indocyanine green is a valid criterion for hepatectomy.

  13. Recommendations for Achieving Accurate Numerical Simulation of Tip Clearance Flows in Transonic Compressor Rotors

    NASA Technical Reports Server (NTRS)

    VanZante, Dale E.; Strazisar, Anthony J.; Wood, Jerry R,; Hathaway, Michael D.; Okiishi, Theodore H.

    2000-01-01

    The tip clearance flows of transonic compressor rotors are important because they have a significant impact on rotor and stage performance. While numerical simulations of these flows are quite sophisticated. they are seldom verified through rigorous comparisons of numerical and measured data because these kinds of measurements are rare in the detail necessary to be useful in high-speed machines. In this paper we compare measured tip clearance flow details (e.g. trajectory and radial extent) with corresponding data obtained from a numerical simulation. Recommendations for achieving accurate numerical simulation of tip clearance flows are presented based on this comparison. Laser Doppler Velocimeter (LDV) measurements acquired in a transonic compressor rotor, NASA Rotor 35, are used. The tip clearance flow field of this transonic rotor was simulated using a Navier-Stokes turbomachinery solver that incorporates an advanced k-epsilon turbulence model derived for flows that are not in local equilibrium. Comparison between measured and simulated results indicates that simulation accuracy is primarily dependent upon the ability of the numerical code to resolve important details of a wall-bounded shear layer formed by the relative motion between the over-tip leakage flow and the shroud wall. A simple method is presented for determining the strength of this shear layer.

  14. Slow late myocardial clearance of thallium: a characteristic phenomenon in coronary artery disease

    SciTech Connect

    Sklar, J.; Kirch, D.; Johnson, T.; Hasegawa, B.; Peck, S.; Steele, P.

    1982-06-01

    Researchers extended the quantitative seven-pinhole method to follow the dynamics of thallium redistribution after exercise. Researchers observed a pattern of slow late thallium clearance that appears to be characteristic of myocardium supplied by obstructed coronary arteries. In 28 subjects, quantitative thallium scintigrams and blood samples for thallium concentration were taken immediately, 2 hours and 4 hours after maximal treadmill exercise. Twenty subjects had coronary artery disease (CAD) and eight were normal. The rate of thallium clearance from the blood (TCB) was compared with the rate of thallium clearance from each segmental region of myocardium between the 2- and 4-hour images. In seven of the eight normal subjects, TCM exceeded TCB in all regions of all images. Seventeen of the 20 CAD patients had at least one region where TCM was less than TCB. Of the 13 patients with multivessel CAD 11 had multiple regions with TCM less than TCB. Using this criterion, we detected 31 of 39 obstructed coronary arteries. Of the 37 regions that were abnormal by this analysis, 30 corresponded to obstructed coronary arteries. In contrast, while conventional circumferential count profile analysis also was abnormal in 17 of the 20 CAD patients, it diagnosed multivessel CAD in only five of the 13 patients that had it. These results show that slow late thallium clearance from myocardium is characteristic of regions of myocardium supplied by diseased coronary arteries and that observation of this phenomenon may improve diagnostic sensitivity for the presence of multivessel CAD.

  15. An advanced stochastic model for mucociliary particle clearance in cystic fibrosis lungs

    PubMed Central

    Sturm, Robert

    2012-01-01

    Background A mathematical model describing mucociliary clearance in cystic fibrosis (CF) patients and its development with progressing course of the disease was developed. The approach should support the prediction of the disease state on the basis of measured bronchial clearance efficiencies. Methods The approach is based on the assumption of a steady-state steady-flow mucus transport through the tracheobronchial tree which enables the determination of airway generation-specific mucus velocities by using a measured tracheal mucus velocity and a realistic morphometric dataset of the human lung. Architecture of the tracheobronchial tree was approximated by a stochastic model, reflecting the intra-subject variability of geometric parameters within a given lung generation. Results As predicted by the appropriately validated mathematical approach, mucociliary clearance efficiency in CF patients is partly significantly decreased with respect to healthy controls. 24-h retention of patients with mild CF (FEV1 >70% of predicted) is reduced by 10% compared to healthy subjects, whilst 24-h retention of patients with moderate to severe CF (FEV1 <70% of predicted) differs by 25% from that of the healthy controls. These discrepancies are further enhanced with continuation of the clearance process. Conclusions The theoretical results lead to the conclusion that CF patients have a higher risk of inhaled particle accumulation and related particle overload in specific lung compartments than healthy subjects. PMID:22295167

  16. Creatinine Clearance Is Associated with Toxicity from Molecularly Targeted Agents in Phase I Trials

    PubMed Central

    Basu, B.; Vitfell-Pedersen, J.; Moreno Garcia, V.; Puglisi, M.; Tjokrowidjaja, A.; Shah, K.; Malvankar, S.; Anghan, B.; de Bono, J.S.; Kaye, S.B.; Molife, L.R.; Banerji, U.

    2012-01-01

    Objectives This study aimed to evaluate any correlations between baseline creatinine clearance and the development of grade 3/4 toxicities during treatment within oncology phase I trials of molecularly targeted agents where entry criteria mandate a serum creatinine of ≤1.5 × the upper limit of normal. Methods Documented toxicity and creatinine clearance (calculated by the Cockcroft-Gault formula) from all patients treated with molecularly targeted agents in the context of phase I trials within our centre over a 5-year period were analyzed. Results Data from 722 patients were analyzed; 116 (16%) developed at least one episode of grade 3/4 toxicity. Patients who developed a late-onset (>1 cycle) grade 3/4 toxicity had a lower creatinine clearance than those who did not (82.69 ml/min vs. 98.97 ml/min; p = < 0.001). Conclusion Creatinine clearance (even when within normal limits) should be studied as a potential factor influencing late toxicities in the clinical trials of molecularly targeted anti-cancer drugs. PMID:22889980

  17. D0 Solenoid Chimney Routing Clearances

    SciTech Connect

    Rucinski, R.; /Fermilab

    1994-02-23

    This engineering note contains information about the measured clearances along the chimney route from the solenoid to the control dewar. This type of information is best conveyed by sketches and a few photos. Twelve photos taken on 2/17/94 are included which gIVe perspective views along the path. The detector was parked in the collision hall on this date. The CF iron was split open to the east and the South EF iron was rolled back. Also the South EndCap Calorimeter was rolled to the south on this day. This allowed personnel access and the photographic opportunity. A full set of raw dimensional sketches are included. These sketches were generated by me using a 25 foot tape measure and a note pad. The sketches are in chronological order with the most recent on top. The first sketch, 5/18/94, describes the 'tightest' location for the upward incline portion of the chimney. The sketches on 2/14/94 thru 2/16/94 are refinements of the early 1992 and 1993 sketches. They pick out quite a bit more detail of specific detector components along the path. The dimensional sketches of 1992 and 1993 gave information in not as much detail and therefore gave a more constrained clearance description. Most of the information of the early sketches was jotted down on the plan view dated 10-29-92. This sketch also had some information lifted from prints which later was superseded by the 1994 sketches. I tried to label components and give views either titled 'Elevation' or 'Plan' which refers to a top view looking down. Also where I could I jotted down direction, ie. South, East etc. Hopefully with a little effort one can decifer it. The curvature of the CC was determined from a three dimensional topographical survey. This survey information is stored in an electronic drawing file 3823.111-ME-317165, 'Solenoid-CC south face 3D shape survey'. The 'z' dimensions for the radial chimney path were picked off this drawing. A curvature was then generated knowing many points by radial and z

  18. An initial evaluation of post-cardiopulmonary bypass acute kidney injury in swine☆

    PubMed Central

    Murphy, Gavin J.; Lin, Hua; Coward, Richard J.; Toth, Tibor; Holmes, Robin; Hall, David; Angelini, Gianni D.

    2016-01-01

    Objective Acute kidney injury (AKI) post-cardiac surgery is associated with mortality rates approaching 20%. The development of effective treatments is hindered by the poor homology between rodent models, the mainstay of research into AKI, and that which occurs in humans. This pilot study aims to characterise post-cardiopulmonary bypass (CPB) AKI in an animal model with potentially greater homology to cardiac surgery patients. Methods and results Adult pigs, weighing 50–75 kg, underwent 2.5 h of CPB. Pigs undergoing saphenous vein grafting procedures served as controls. Pre-CPB measures of porcine renal function were within normal ranges for adult humans. The effect of CPB on renal function; a 25% reduction in 51Cr-EDTA clearance ( p = 0.068), and a 33% reduction in creatinine clearance (p = 0.043), was similar to those reported in clinical studies. CPB resulted in tubular epithelial injury (median NAG/creatinine ratio 2.6 u mmol−1 (interquartile range (IQR): 0.81–5.43) post-CPB vs 0.48 u mmol−1 (IQR: 0.37–0.97) pre-CPB, p = 0.043) as well as glomerular and/or proximal tubular injury (median albumin/creatinine ratio 6.8 mg mmol−1 (IQR: 5.45–13.06) post-CPB vs 1.10 mg mmol−1 (IQR: 0.05–2.00) pre-CPB, p = 0.080). Tubular injury scores were significantly higher in kidneys post-CPB (median score 2.0 (IQR: 1.0–2.0) relative to vein graft controls (median score 1.0 (IQR 1.0–1.0), p = 0.019). AKI was associated with endothelial injury and activation, as demonstrated by reduced DBA (dolichos biflorus agglutinin) lectin and increased endothelin-1 and vascular cell adhesion molecule (VCAM) staining. Conclusions The porcine model of post-CPB AKI shows significant homology to AKI in cardiac surgical patients. It links functional, urinary and histological measures of kidney injury and may offer novel insights into the mechanisms underlying post-CPB AKI. PMID:19692256

  19. Effects of drugs on mucus clearance.

    PubMed

    Houtmeyers, E; Gosselink, R; Gayan-Ramirez, G; Decramer, M

    1999-08-01

    Mucociliary clearance (MCC), the process in which airway mucus together with substances trapped within are moved out of the lungs, is an important defence mechanism of the human body. Drugs may alter this process, such that it is necessary to know the effect of the drugs on MCC. Indeed, agents stimulating MCC may be used therapeutically in respiratory medicine, especially in patients suspected of having an impairment of their mucociliary transport system. In contrast, caution should be taken with drugs depressing MCC as an undesired side-effect, independently of their therapeutic indication. Since cough clearance (CC) serves as a back-up system when MCC fails, the influence of drugs must be examined not only on MCC but also on CC. Ultimately, the clinical repercussions of alterations in mucus transport induced by drug administration must be studied. Tertiary ammonium compounds (anticholinergics), aspirin, anaesthetic agents and benzodiazepines have been shown to be capable of depressing the mucociliary transport system. Cholinergics, methylxanthines, sodium cromoglycate, hypertonic saline, saline as well as water aerosol have been shown to increase MCC. Adrenergic antagonists, guaifenesin, S-carboxymethylcysteine, sodium 2-mercapto-ethane sulphonate and frusemide have been reported not to alter the mucociliary transport significantly. Amiloride, uridine 5'-triphosphate (UTP), quaternary ammonium compounds (anticholinergics), adrenergic agonists, corticosteroids, recombinant human deoxyribonuclease (rhDNase), N-acetylcysteine, bromhexine and ambroxol have been reported either not to change or to augment MCC. Indirect data suggest that surfactant as well as antibiotics may improve the mucociliary transport system. As for the influence of drugs on CC, amiloride and rhDNase have been demonstrated to increase the effectiveness of cough. A trend towards an improved CC was noted after treatment with adrenergic agonists. The anticholinergic agent ipratropium bromide, which

  20. Radioaerosol lung clearance in patients with active pulmonary sarcoidosis

    SciTech Connect

    Jacobs, M.P.; Baughman, R.P.; Hughes, J.; Fernandez-Ulloa, M.

    1985-05-01

    Pulmonary radioaerosol clearance rate of /sup 99m/Tc diethylenetriamine pentacetate (DTPA) in 14 patients with untreated sarcoidosis was compared with /sup 67/Ga lung scan and increased lymphocytes in the bronchoalveolar lavage (BAL) fluid. Nine healthy nonsmoking subjects had a mean DTPA clearance rate of 1.18%/min (range, 0.54 to 1.60%/min). Eight of 14 patients with sarcoidosis had clearance rates greater than 1.60%/min. Of those 8 patients with abnormal DTPA clearance, 4 had positive gallium scans, 4 had more than 17% lymphocytes in the BAL fluid, and 3 had both tests positive. To study the cause of abnormal DTPA clearance, 23 subjects (including 3 normal controls, all 14 patients with sarcoidosis, and 6 patients with localized disease on chest roentgenogram) underwent both DTPA clearance studies and BAL for quantitation of the amount of albumin in lung fluid. There was a positive correlation between the rate of DTPA clearance and the albumin concentration in lung fluid (r = 0.87, p less than 0.01).

  1. Integrated Turbine Tip Clearance and Gas Turbine Engine Simulation

    NASA Technical Reports Server (NTRS)

    Chapman, Jeffryes W.; Kratz, Jonathan; Guo, Ten-Huei; Litt, Jonathan

    2016-01-01

    Gas turbine compressor and turbine blade tip clearance (i.e., the radial distance between the blade tip of an axial compressor or turbine and the containment structure) is a major contributing factor to gas path sealing, and can significantly affect engine efficiency and operational temperature. This paper details the creation of a generic but realistic high pressure turbine tip clearance model that may be used to facilitate active tip clearance control system research. This model uses a first principles approach to approximate thermal and mechanical deformations of the turbine system, taking into account the rotor, shroud, and blade tip components. Validation of the tip clearance model shows that the results are realistic and reflect values found in literature. In addition, this model has been integrated with a gas turbine engine simulation, creating a platform to explore engine performance as tip clearance is adjusted. Results from the integrated model explore the effects of tip clearance on engine operation and highlight advantages of tip clearance management.

  2. Analysis of viral clearance unit operations for monoclonal antibodies.

    PubMed

    Miesegaes, George; Lute, Scott; Brorson, Kurt

    2010-06-01

    Demonstration of viral clearance is a critical step in assuring the safety of biotechnology products. We generated a viral clearance database that contains product information, unit operation process parameters, and viral clearance data from monoclonal antibody and antibody-related regulatory submissions to FDA. Here we present a broad overview of the database and resulting analyses. We report that the diversity of model viruses tested expands as products transition to late-phase. We also present averages and ranges of viral clearance results by Protein A and ion exchange chromatography steps, low pH chemical inactivation, and virus filtration, focusing on retro- and parvoviruses. For most unit operations, an average log reduction value (LRV, a measure of clearance power) for retrovirus of >4 log(10) were measured. Cases where clearance data fell outside of the anticipated range (i.e., outliers) were rationally explained. Lastly, a historical analysis did not find evidence of any improvement trend in viral clearance over time. The data collectively suggest that many unit operations in general can reliably clear viruses.

  3. Dynamic modelling and experimental study of cantilever beam with clearance

    NASA Astrophysics Data System (ADS)

    Li, B.; Jin, W.; Han, L.; He, Z.

    2012-05-01

    Clearances occur in almost all mechanical systems, typically such as the clearance between slide plate of gun barrel and guide. Therefore, to study the clearances of mechanisms can be very important to increase the working performance and lifetime of mechanisms. In this paper, rigid dynamic modelling of cantilever with clearance was done according to the subject investigated. In the rigid dynamic modelling, clearance is equivalent to the spring-dashpot model, the impact of beam and boundary face was also taken into consideration. In ADAMS software, the dynamic simulation was carried out according to the model above. The software simulated the movement of cantilever with clearance under external excitation. Research found: When the clearance is larger, the force of impact will become larger. In order to study how the stiffness of the cantilever's supporting part influences natural frequency of the system, A Euler beam which is restricted by a draught spring and a torsion spring at its end was raised. Through numerical calculation, the relationship between natural frequency and stiffness was found. When the value of the stiffness is close to the limit value, the corresponding boundary condition is illustrated. An ADAMS experiment was carried out to check the theory and the simulation.

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

    SciTech Connect

    Williams, G.A.; Hatchell, D.L.; Collier, B.D.; Knobel, J.

    1984-06-01

    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.

  5. Toward a Fast-Response Active Turbine Tip Clearance Control

    NASA Technical Reports Server (NTRS)

    Melcher, Kevin J.; Kypuros, Javier A.

    2003-01-01

    This paper describes active tip clearance control research being conducted by NASA to improve turbine engine systems. The target application for this effort is commercial aircraft engines. However, technologies developed for clearance control can benefit a broad spectrum of current and future turbomachinery. The first portion of the paper addresses the research from a programmatic viewpoint. Recent studies that provide motivation for the work, identification of key technologies, and NASA's plan for addressing deficiencies in the technologies are discussed. The later portion of the paper drills down into one of the key technologies by presenting equations and results for a preliminary dynamic model of the tip clearance phenomena.

  6. Aerosol Medications for Treatment of Mucus Clearance Disorders.

    PubMed

    Rubin, Bruce K

    2015-06-01

    Airway mucus hypersecretion and secretion retention can result from inflammation, irritation, stimulation, or mucus-producing tumors. Secretion clearance can be furthered hampered by ciliary dysfunction and by weakness or restrictive lung disease, leading to an ineffective cough. There are a number of different mucoactive medications that have been used to reduce hypersecretion, make secretions easier to transport, or increase the efficiency of cough or mucus clearance. In this paper, I review the pathophysiology of secretory hyper-responsiveness and mucus hypersecretion and discuss the different aerosol medications that can be used to augment secretion clearance. PMID:26070577

  7. Time-of-Flight Tip-Clearance Measurements

    NASA Technical Reports Server (NTRS)

    Dhadwal, H. S.; Kurkov, A. P.; Janetzke, D. C.

    1999-01-01

    In this paper a time-of-flight probe system incorporating the two integrated fiber optic probes which are tilted equally relative to the probe holder centerline, is applied for the first time to measure the tip clearance of an advanced fan prototype. Tip clearance is largely independent of the signal amplitude and it relies on timing measurement. This work exposes optical effects associated with the fan blade stagger angle that were absent during the original spin-rig experiment on the zero stagger rotor. Individual blade tip clearances were measured with accuracy of +/- 127-mm (+/- 0.005-in). Probe features are discussed and improvements to the design are suggested.

  8. Aerosol Medications for Treatment of Mucus Clearance Disorders.

    PubMed

    Rubin, Bruce K

    2015-06-01

    Airway mucus hypersecretion and secretion retention can result from inflammation, irritation, stimulation, or mucus-producing tumors. Secretion clearance can be furthered hampered by ciliary dysfunction and by weakness or restrictive lung disease, leading to an ineffective cough. There are a number of different mucoactive medications that have been used to reduce hypersecretion, make secretions easier to transport, or increase the efficiency of cough or mucus clearance. In this paper, I review the pathophysiology of secretory hyper-responsiveness and mucus hypersecretion and discuss the different aerosol medications that can be used to augment secretion clearance.

  9. Differences in amyloid-β clearance across mouse and human blood-brain barrier models: kinetic analysis and mechanistic modeling.

    PubMed

    Qosa, Hisham; Abuasal, Bilal S; Romero, Ignacio A; Weksler, Babette; Couraud, Pierre-Oliver; Keller, Jeffrey N; Kaddoumi, Amal

    2014-04-01

    Alzheimer's disease (AD) has a characteristic hallmark of amyloid-β (Aβ) accumulation in the brain. This accumulation of Aβ has been related to its faulty cerebral clearance. Indeed, preclinical studies that used mice to investigate Aβ clearance showed that efflux across blood-brain barrier (BBB) and brain degradation mediate efficient Aβ clearance. However, the contribution of each process to Aβ clearance remains unclear. Moreover, it is still uncertain how species differences between mouse and human could affect Aβ clearance. Here, a modified form of the brain efflux index method was used to estimate the contribution of BBB and brain degradation to Aβ clearance from the brain of wild type mice. We estimated that 62% of intracerebrally injected (125)I-Aβ40 is cleared across BBB while 38% is cleared by brain degradation. Furthermore, in vitro and in silico studies were performed to compare Aβ clearance between mouse and human BBB models. Kinetic studies for Aβ40 disposition in bEnd3 and hCMEC/D3 cells, representative in vitro mouse and human BBB models, respectively, demonstrated 30-fold higher rate of (125)I-Aβ40 uptake and 15-fold higher rate of degradation by bEnd3 compared to hCMEC/D3 cells. Expression studies showed both cells to express different levels of P-glycoprotein and RAGE, while LRP1 levels were comparable. Finally, we established a mechanistic model, which could successfully predict cellular levels of (125)I-Aβ40 and the rate of each process. Established mechanistic model suggested significantly higher rates of Aβ uptake and degradation in bEnd3 cells as rationale for the observed differences in (125)I-Aβ40 disposition between mouse and human BBB models. In conclusion, current study demonstrates the important role of BBB in the clearance of Aβ from the brain. Moreover, it provides insight into the differences between mouse and human BBB with regards to Aβ clearance and offer, for the first time, a mathematical model that describes

  10. Differences in amyloid-β clearance across mouse and human blood-brain barrier models: Kinetic analysis and mechanistic modeling

    PubMed Central

    Qosa, Hisham; Abuasal, Bilal S.; Romero, Ignacio A.; Weksler, Babette; Couraud, Pierre-Oliver; Keller, Jeffrey N.; Kaddoumi, Amal

    2014-01-01

    Alzheimer’s disease (AD) has a characteristic hallmark of amyloid-β (Aβ) accumulation in the brain. This accumulation of Aβ has been related to its faulty cerebral clearance. Indeed, preclinical studies that used mice to investigate Aβ clearance showed that efflux across blood-brain barrier (BBB) and brain degradation mediate efficient Aβ clearance. However, the contribution of each process to Aβ clearance remains unclear. Moreover, it is still uncertain how species differences between mouse and human could affect Aβ clearance. Here, a modified form of the brain efflux index method was used to estimate the contribution of BBB and brain degradation to Aβ clearance from the brain of wild type mice. We estimated that 62% of intracerebrally injected 125I-Aβ40 is cleared across BBB while 38% is cleared by brain degradation. Furthermore, in vitro and in silico studies were performed to compare Aβ clearance between mouse and human BBB models. Kinetic studies for Aβ40 disposition in bEnd3 and hCMEC/D3 cells, representative in vitro mouse and human BBB models, respectively, demonstrated 30-fold higher rate of 125I-Aβ40 uptake and 15-fold higher rate of degradation by bEnd3 compared to hCMEC/D3 cells. Expression studies showed both cells to express different levels of P-glycoprotein and RAGE, while LRP1 levels were comparable. Finally, we established a mechanistic model, which could successfully predict cellular levels of 125I-Aβ40 and the rate of each process. Established mechanistic model suggested significantly higher rates of Aβ uptake and degradation in bEnd3 cells as rationale for the observed differences in 125I-Aβ40 disposition between mouse and human BBB models. In conclusion, current study demonstrates the important role of BBB in the clearance of Aβ from the brain. Moreover, it provides insight into the differences between mouse and human BBB with regards to Aβ clearance and offer, for the first time, a mathematical model that describes A

  11. Differences in amyloid-β clearance across mouse and human blood-brain barrier models: kinetic analysis and mechanistic modeling.

    PubMed

    Qosa, Hisham; Abuasal, Bilal S; Romero, Ignacio A; Weksler, Babette; Couraud, Pierre-Oliver; Keller, Jeffrey N; Kaddoumi, Amal

    2014-04-01

    Alzheimer's disease (AD) has a characteristic hallmark of amyloid-β (Aβ) accumulation in the brain. This accumulation of Aβ has been related to its faulty cerebral clearance. Indeed, preclinical studies that used mice to investigate Aβ clearance showed that efflux across blood-brain barrier (BBB) and brain degradation mediate efficient Aβ clearance. However, the contribution of each process to Aβ clearance remains unclear. Moreover, it is still uncertain how species differences between mouse and human could affect Aβ clearance. Here, a modified form of the brain efflux index method was used to estimate the contribution of BBB and brain degradation to Aβ clearance from the brain of wild type mice. We estimated that 62% of intracerebrally injected (125)I-Aβ40 is cleared across BBB while 38% is cleared by brain degradation. Furthermore, in vitro and in silico studies were performed to compare Aβ clearance between mouse and human BBB models. Kinetic studies for Aβ40 disposition in bEnd3 and hCMEC/D3 cells, representative in vitro mouse and human BBB models, respectively, demonstrated 30-fold higher rate of (125)I-Aβ40 uptake and 15-fold higher rate of degradation by bEnd3 compared to hCMEC/D3 cells. Expression studies showed both cells to express different levels of P-glycoprotein and RAGE, while LRP1 levels were comparable. Finally, we established a mechanistic model, which could successfully predict cellular levels of (125)I-Aβ40 and the rate of each process. Established mechanistic model suggested significantly higher rates of Aβ uptake and degradation in bEnd3 cells as rationale for the observed differences in (125)I-Aβ40 disposition between mouse and human BBB models. In conclusion, current study demonstrates the important role of BBB in the clearance of Aβ from the brain. Moreover, it provides insight into the differences between mouse and human BBB with regards to Aβ clearance and offer, for the first time, a mathematical model that describes

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

    SciTech Connect

    Wehmann, R.E.; Blithe, D.L.; Flack, M.R.; Nisula, B.C. )

    1989-09-01

    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.

  13. A biomathematical model of particle clearance and retention in the lungs of coal miners. II. Evaluation of variability and uncertainty.

    PubMed

    Kuempel, E D; Tran, C L; Smith, R J; Bailer, A J

    2001-08-01

    The objective of this study is to investigate the sources of variability and uncertainty in a previously developed human lung dosimetry model. That three-compartment model describes the retention and clearance kinetics of respirable particles in the gas-exchange region of the lungs. It was calibrated using exposure histories and lung dust burden data in U.S. coal miners. A multivariate parameter estimation and optimization method was developed for fitting the dosimetry model to these human data. Models with various assumptions about overloading of alveolar clearance and interstitialization (sequestration) of particles were evaluated. Variability in the estimated clearance rate coefficients was assessed empirically by fitting the model to groups' and to each miner's data. Distributions of lung and lymph node particle burdens were computed at working lifetime exposures, using the variability in the estimated individual clearance rate coefficients. These findings confirm those of the earlier analysis; i.e., the best-fitting exposure-dose model to these data has substantial interstitialization/sequestration of particles and no dose-dependent decline in alveolar clearance. Among miners with different characteristics for smoking, disease, and race, the group median estimated alveolar clearance rate coefficients varied by a factor of approximately 4. Adjustment for these group differences provided some improvement in the dosimetry model fit to all miners (up to 25% reduction in MSE), although unexplained interindividual differences made up the largest source of variability. The predicted mean lung and lymph node particle burdens at age 75 after exposure to respirable coal mine dust at 2 mg/m(2) for a 45-year working lifetime were 12 g (5th and 95th percentiles, 3.0-26 g) and 1.9 g (0.26-5.3), respectively. This study provides quantitative information on variability in particle retention and clearance kinetics in humans. It is useful for risk assessment by providing

  14. An inulin-like clearance based on the atomic absorbance of a copper cluster compound.

    PubMed

    Bergevin, G H; Red, T; Bonakdar, M; Pope, S; Wells, F; Wright, J R

    1984-01-01

    Copper cluster ions which contain 14 copper atoms and 12 penicillamine ligands produce no indications of toxicity when injected intravenously in doses of 12 mg/kg (as the hydrated sodium salt). These ions pass freely through the Bowman's capsules and are eliminated with the urinary effluent. The blood plasma and blood serum kinetics of the process may be followed with selectivity and sensitivity using copper's flame atomic absorbance at 324.7 nm, and a first order rate law with a half life of approximately ten minutes is observed. Clearance obtained by this method is inulin-like. The copper cluster ion does not readily permeate the erythrocyte membrane, and its distribution immediately following intravenous injection appears to be essentially that of the plasma volume. Since serum or plasma preparation for atomic absorbance measurements is minimal, the method might have applications in rapid determinations of renal clearance. PMID:6522464

  15. Intraarticular volume and clearance in human synovial effusions

    SciTech Connect

    Wallis, W.J.; Simkin, P.A.; Nelp, W.B.; Foster, D.M.

    1985-04-01

    Intraarticular volumes were measured by radiolabeled albumin (RISA) distribution in chronic knee effusions from 11 rheumatoid arthritis patients and 9 osteoarthritis patients. Volumes of synovial fluid obtained at joint aspiration were substantially less than those found by RISA dilution. Up to 24 hours was needed for full distribution of RISA throughout the intraarticular compartment. Measured 123I and RISA radioactivity over the knee described monoexponential rate constants, lambda (minute-1). The clearance of 123I and RISA from synovial effusions was derived by the formulation volume (ml) X lambda (minute-1) = clearance (ml/minute). RISA clearance in rheumatoid effusions was significantly greater than that found in osteoarthritis effusions. Intraarticular volume and isotope clearance were easily quantified and provide measures for further evaluating the microvascular physiology of synovial effusions.

  16. IFNL4 affects clearance of hepatitis C virus

    Cancer.gov

    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

  17. Further Characterization of an Active Clearance Control Concept

    NASA Technical Reports Server (NTRS)

    Taylor, Shawn C.; Steinetz, Bruce M.; Oswald, Jay J.

    2007-01-01

    A new test chamber and precision hydraulic actuation system were incorporated into an active clearance control (ACC) test rig at NASA Glenn Research Center. Using the improved system, a fast-acting, mechanically-actuated, ACC concept was evaluated at engine simulated temperatures and pressure differentials up to 1140 F and 120 psig, on the basis of secondary seal leakage and kinematic controllability. During testing, the ACC concept tracked a simulated flight clearance transient profile at 1140 F, 120 psig, with a maximum error of only 0.0012 in. Comparison of average dynamic leakage of the system with average static leakage did not show significant differences between the two operating conditions. Calculated effective clearance values for the rig were approximately 0.0002 in. at 120 psig, well below the industry specified effective clearance threshold of 0.001 in.

  18. High Temperature Evaluation of an Active Clearance Control System Concept

    NASA Technical Reports Server (NTRS)

    Taylor, Shawn C.; Steinetz, Bruce M.; Oswald, Jay J.

    2006-01-01

    A mechanically actuated blade tip clearance control concept was evaluated in a nonrotating test rig to quantify secondary seal leakage at elevated temperatures. These tests were conducted to further investigate the feasibility of actively controlling the clearance between the rotor blade tips and the surrounding shroud seal in the high pressure turbine (HPT) section of a turbine engine. The test environment simulates the state of the back side of the HPT shroud seal with pressure differentials as high as 120 psig and temperatures up to 1000 F. As expected, static secondary seal leakage decreased with increasing temperature. At 1000 F, the test rig's calculated effective clearance (at 120 psig test pressure) was 0.0003 in., well within the industry specified effective clearance goal.

  19. 32 CFR 644.516 - Clearance of Air Force lands.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... PROPERTY REAL ESTATE HANDBOOK Disposal Clearance of Explosive Hazards and Other Contamination from Proposed... Defense requirements, the appropriate DE will obtain a certificate as to the extent of contamination...

  20. 49 CFR 229.71 - Clearance above top of rail.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Suspension System § 229.71 Clearance above top of rail. No part or appliance of a locomotive except the wheels,...

  1. Antibody-Mediated Clearance of Alphavirus Infection from Neurons

    NASA Astrophysics Data System (ADS)

    Levine, Beth; Hardwick, J. Marie; Trapp, Bruce D.; Crawford, Thomas O.; Bollinger, Robert C.; Griffin, Diane E.

    1991-11-01

    Humoral immunity is important for protection against viral infection and neutralization of extracellular virus, but clearance of virus from infected tissues is thought to be mediated solely by cellular immunity. However, in a SCID mouse model of persistent alphavirus encephalomyelitis, adoptive transfer of hyperimmune serum resulted in clearance of infectious virus and viral RNA from the nervous system, whereas adoptive transfer of sensitized T lymphocytes had no effect on viral replication. Three monoclonal antibodies to two different epitopes on the E2 envelope glycoprotein mediated viral clearance. Treatment of alphavirus-infected primary cultured rat neurons with these monoclonal antibodies to E2 resulted in decreased viral protein synthesis, followed by gradual termination of mature infectious virion production. Thus, antibody can mediate clearance of alphavirus infection from neurons by restricting viral gene expression.

  2. Enhancement of the amylase-creatinine clearance ratio in pregnancy.

    PubMed

    Naeije, R; Neuray, F; Van Melsen, A; Delcourt, A

    1979-01-01

    The renal clearance of amylase, expressed as a proportion of simultaneous creatinine clearance (Cam/-Ccr), was determined in 131 women in various stages of pregnancy. No abnormal serum levels of amylase were found. A moderate but significant increase in Cam/Ccr occurred during the last 15 weeks of pregnancy. Possible causes for this change were investigated in smaller groups of subjects. No increase in rapidly cleared isoamylase could be detected. No modification in renal tubular handling of protein could be evidenced, as assessed by measurements of the renal clearance of beta 2 microglobulin, expressed as a proportion of simultaneous creatinine clearance. An incrased glomerular permeability to amylase probably accounts for elevated Cam/Ccr in pregnancy.

  3. 32 CFR 644.527 - Recording Statements of Clearance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... PROPERTY REAL ESTATE HANDBOOK Disposal Clearance of Explosive Hazards and Other Contamination from Proposed..., if possible, as part of the permanent history of the property involved, with the proper county...

  4. 32 CFR 644.527 - Recording Statements of Clearance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... PROPERTY REAL ESTATE HANDBOOK Disposal Clearance of Explosive Hazards and Other Contamination from Proposed..., if possible, as part of the permanent history of the property involved, with the proper county...

  5. 32 CFR 644.527 - Recording Statements of Clearance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... PROPERTY REAL ESTATE HANDBOOK Disposal Clearance of Explosive Hazards and Other Contamination from Proposed..., if possible, as part of the permanent history of the property involved, with the proper county...

  6. 32 CFR 644.527 - Recording Statements of Clearance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... PROPERTY REAL ESTATE HANDBOOK Disposal Clearance of Explosive Hazards and Other Contamination from Proposed..., if possible, as part of the permanent history of the property involved, with the proper county...

  7. 54. CLEARANCE OF SITE PRIOR TO CONSTRUCTION OF BREAKER BUILDING, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    54. CLEARANCE OF SITE PRIOR TO CONSTRUCTION OF BREAKER BUILDING, AND CONSTRUCTION OF EMBANKMENT FOR RAILROAD SPUR. c.1898 (AKZO No. A-3) - Avery Island Salt Works, Akzo Salt Incorporated, Avery Island, Iberia Parish, LA

  8. Early Agriculture: Land Clearance and Climate Effects

    NASA Astrophysics Data System (ADS)

    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.

  9. Calculation of tip clearance effects in a transonic compressor rotor

    NASA Technical Reports Server (NTRS)

    Chima, R. V.

    1996-01-01

    The flow through the tip clearance region of a transonic compressor rotor (NASA rotor 37) was computed and compared to aerodynamic probe and laser anemometer data. Tip clearance effects were modeled both by gridding the clearance gap and by using a simple periodicity model across the ungridded gap. The simple model was run with both the full gap height, and with half the gap height to simulate a vena-contracta effect. Comparisons between computed and measured performance maps and downstream profiles were used to validate the models and to assess the effects of gap height on the simple clearance model. Recommendations were made concerning the use of the simple clearance model. Detailed comparisons were made between the gridded clearance gap solution and the laser anemometer data near the tip at two operating points. The computer results agreed fairly well with the data but overpredicted the extent of the casing separation and underpredicted the wake decay rate. The computations were then used to describe the interaction of the tip vortex, the passage shock, and the casing boundary layer.

  10. Calculation of Tip Clearance Effects in a Transonic Compressor Rotor

    NASA Technical Reports Server (NTRS)

    Chima, R. V.

    1998-01-01

    The flow through the tip clearance region of a transonic compressor rotor (NASA rotor 37) was computed and compared to aerodynamic probe and laser anemometer data. Tip clearance effects were modeled both by gridding the clearance gap and by using a simple periodicity model across the ungridded gap. The simple model was run with both the full gap height, and with half the gap height to simulate a vena-contracta effect. Comparisons between computed and measured performance maps and downstream profiles were used to validate the models and to assess the effects of gap height on the simple clearance model. Recommendations were made concern- ing the use of the simple clearance model Detailed comparisons were made between the gridded clearance gap solution and the laser anemometer data near the tip at two operating points. The computed results agreed fairly well with the data but overpredicted the extent of the casing separation and underpredicted the wake decay rate. The computations were then used to describe the interaction of the tip vortex, the passage shock, and the casing boundary layer.

  11. Long-term clearance from small airways decreases with age.

    PubMed

    Svartengren, M; Falk, R; Philipson, K

    2005-10-01

    The prevalence of respiratory symptoms increases with age. Age has been found to be negatively associated with large airway clearance. The small airways region is considered important for development of airway disease. Clearance after the first 24 h was studied in 46 healthy subjects with a wide age distribution, (mean 42, range 19-81 yrs). All subjects inhaled monodisperse 6 microm Teflon particles labelled with 111In, with an extremely slow inhalation flow (0.05 L.s-1). The particles were mainly deposited in the small conducting airways. Lung retention was measured at 0 and 24 h, and at 7, 14 and 21 days after inhalation. Significant relationships were found for the individual 24 h "large" airway clearance in per cent of initial lung deposition with age, forced expiratory volume in one second and forced vital capacity. Age was negatively associated with "small" airway clearance after 24 h as estimated at 2, 7, 14 and 21 days. Using stepwise linear regression only age remained significantly associated to clearance. In conclusion, small airway clearance over 21 days was found to decrease with age. This might be one factor associated with the high prevalence of respiratory symptoms associated among the elderly.

  12. Urinary and metabolic clearances of arginine vasopressin in normal subjects

    SciTech Connect

    Moses, A.M.; Steciak, E.

    1986-08-01

    Synthetic arginine vasopressin (AVP) was infused into 11 hydrated normal subjects at five different infusion rates ranging from 10 to 350 U kg min . 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 ( U/ml) and excretion rates ( U/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.

  13. Scintigraphic monitoring of mucociliary tracheo-bronchial clearance of technetium-99m macroaggregated albumin aerosol

    SciTech Connect

    Zwas, S.T.; Katz, I.; Belfer, B.; Baum, G.L.; Aharonson, E.

    1987-02-01

    A simple method for in vivo monitoring mucociliary tracheo-bronchial clearance is described. Eighteen healthy subjects and 13 patients with various chronic lung diseases were studied by this method. The principle of using an aerosol administration system similar to the system used for routine ventilation lung studies is stressed. Proximal large airway deposition of the radioaerosol was obtained by using relatively large particles (average diameter 2 microM) of (99mTc)MAA aerosol. Monitoring was performed by visual inspection of the tracheo-bronchial cinescintigraphic ascendence of the accumulated radioactive boli and by assessing their rate of clearance via automated computer analysis of the time-activity curves, following the movement of each bolus. The normal mean +/- s.d. clearance rate thus obtained was 4.7 +/- 1.3 mm/min. This rate appears to be more precise as compared with the range of results obtained by other radioisotopic methods. Significantly faster rates, mean 8.2 +/- 1.4 mm/min (p less than 0.001) were obtained in bronchiectatic patients while slower rates (2.8 mm/min) were seen in a patient with ciliary dyskinesia.

  14. Scalable and DiI-compatible optical clearance of the mammalian brain

    PubMed Central

    Hou, Bing; Zhang, Dan; Zhao, Shan; Wei, Mengping; Yang, Zaifu; Wang, Shaoxia; Wang, Jiarui; Zhang, Xin; Liu, Bing; Fan, Lingzhong; Li, Yang; Qiu, Zilong; Zhang, Chen; Jiang, Tianzi

    2015-01-01

    Efficient optical clearance is fundamental for whole brain imaging. In particular, clearance of the brain without membrane damage is required for the imaging of lipophilic tracer-labeled neural tracts. Relying on an ascending gradient of fructose solutions, SeeDB can achieve sufficient transparency of the mouse brain while ensuring that the plasma membrane remains intact. However, it is challenging to extend this method to larger mammalian brains due to the extremely high viscosity of the saturated fructose solution. Here we report a SeeDB-derived optical clearing method, termed FRUIT, which utilizes a cocktail of fructose and urea. As demonstrated in the adult mouse brain, combination of these two highly water-soluble clearing agents exerts a synergistic effect on clearance. More importantly, the final FRUIT solution has low viscosity so as to produce transparency of the whole adult rabbit brain via arterial perfusion, which is impossible to achieve with a saturated fructose solution. In addition to good compatibility with enhanced yellow fluorescent protein, the cocktail also preserves the fluorescence of the lipophilic tracer DiI. This work provides a volume-independent optical clearing method which retains the advantages of SeeDB, particularly compatibility with lipophilic tracers. PMID:25759641

  15. Novel host genetic variations associated with spontaneous clearance of a single-source outbreak of HCV1b infections

    PubMed Central

    You, Hong; Liu, Sandu; Xie, Yong; Cong, Rui; Sun, Yameng; Ren, Jingjing; Wei, Kangfei; Jin, Xin; Shi, Yujian; Zhang, Haiying; Li, Jie; Wei, Lai; Zhuang, Hui; Cheng, Mingliang; Jia, Jidong

    2014-01-01

    Background and aims A total of 105 patients were identified as accidentally infected with hepatitis C virus genotype 1b (HCV1b) through blood transfusion from a single blood donor. This group provides a unique patient population to study host factors involved in the spontaneous clearance of HCV and disease progression. Methods Clinical markers, HCV RNA and eight single nucleotide polymorphisms (SNPs) of interleukin-28B (IL-28B) were detected. Exome capture and sequencing were analysed for association with HCV clearance. Results Among the 85 patients with the positive HCV antibody, 27 cases (31.8%) were HCV RNA negative over a period of 9–12 years. Of the 58 patients with positive HCV RNA, 22.4% developed chronic hepatitis, and 5.2% developed cirrhosis. Age was found to be associated with HCV1b clearance. IL-28 rs10853728 CC showed the trend. By exon sequencing, 39 SNPs were found to be significantly different in spontaneous clearance patients (p<0.001). Two SNPs in the tenascin receptor (TNR), five in the transmembrane protease serine 11A (TMPRSS11A), and one in the serine peptidase inhibitor kunitz type 2 (SPINT2) showed the closest associations (p<10−5). Conclusions Host genetic analyses on the unique, single source HCV1b-infected patient population has suggested that age and mutations in TNR, TMPRSS11A and SPINT2 genes may be factors associated with HCV clearance. PMID:26462265

  16. [Constant-infusion technique of inulin clearance without urine collection].

    PubMed

    Kamei, Koichi; Ito, Shuichi; Iijima, Kazumoto

    2011-01-01

    Inulin clearance is accepted as the gold standard for estimating the glomerular filtration rate (GFR). However, the method of this examination is troublesome and infants need difficult bladder catheterization. The existence of residual urine results in an inaccurate estimation of GFR and the proceduse requires a large amount of transfusion. In the plasma infusion method, inulin reaches an equilibrium in which the inulin urinary excretion rate is equal to the infusion rate, and urine collection is unnecessary. We estimated GFR in 21 children using both the plasma infusion method and renal infusion method. In the renal infusion method, the loading infusion of 1% inulin was administered over 30 minutes at the dose of 5 mL/kg body weight, followed by maintenance infusion at the constant speed (mL/hour) of 1.5 x estimated GFR (mL/min/1.73 m2) x body surface area (m2)/ 1.73. Three 30-minute urine collections were performed and the plasma inulin levels were measured to estimate GFR. In the plasma infusion method, maintenance infusion was conducted at the speed (mL/hour) of 0.6 x estimated GFR (mL/min/1.73 m2) x body surface area (m2)/1.73. The mean plasma inulin concentrations at 8, 9 and 10 hours were examined and GFR was calculated with the infusion rate. The GFRs for the renal infusion methods (Cin) and plasma infusion methods (e-Cin) were 91.90 +/- 39.61 and 95.33 +/- 38.08 mL/min/1.73 m2, respectively. The values for Cin and e-Cin showed good linear correlation (R2 = 0.81). The value of e-Cin/Cin was 1.069 +/- 0.172 and the mean e-Cin value was only 7% higher than that of Cin. We believe that GFR estimated by the constant infusion method shows a value approximating that estimated by the standard method. This technique is noninvasive for infants and the GFR of children who have vesicoureteral reflux or residual urine in the bladder can be estimated. The method does not need a large amount of transfusion and is suitable for children with heart failure. We believe that

  17. Steady-State Dynamic Behavior of a Flexible Rotor With Auxiliary Support From a Clearance Bearing

    NASA Technical Reports Server (NTRS)

    Xie, Huajun; Flowers, George T.; Feng, Li; Lawrence, Charles T.

    1996-01-01

    This paper investigates the steady-state responses of a rotor system supported by auxiliary bearings in which there is a clearance between the rotor and the inner race of the bearing. A simulation model based upon the rotor of a production jet engine is developed and its steady-state behavior is explored over a wide range of operating conditions for various parametric configurations. Specifically, the influence of rotor imbalance, clearance, support stiffness and damping is studied. Bifurcation diagrams are used as a tool to examine the dynamic behavior of this system as a function of the afore mentioned parameters. The harmonic balance method is also employed for synchronous response cases. The observed dynamical responses is discussed and some insights into the behavior of such systems are presented.

  18. How important is gametocyte clearance after malaria therapy?

    PubMed

    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

  19. Does Taper Angle Clearance Influence Fretting and Corrosion Damage at the Head-Stem Interface? A Matched Cohort Retrieval Study

    PubMed Central

    Kocagöz, Sevi B.; Underwood, Richard J.; Sivan, Shiril; Gilbert, Jeremy L.; MacDonald, Daniel W.; Day, Judd S.; Kurtz, Steven M.

    2014-01-01

    Previous studies have speculated that modular taper design may have an effect on the corrosion and material loss at the taper surfaces. We present a novel method to measure taper angle for retrieved head taper and stem trunnions using a roundness machine (Talyrond 585, Taylor Hobson, UK). We also investigated the relationship between taper angle clearance and visual fretting-corrosion score at the taper-trunnion junction using a matched cohort study of 50 ceramic and 50 metal head-stem pairs. In this study, no correlation was observed between the taper angle clearance and the visual fretting-corrosion scores in either the ceramic or the metal cohorts. PMID:24610994

  20. Ethanol reduces evoked dopamine release and slows clearance in the rat medial prefrontal cortex

    PubMed Central

    Shnitko, Tatiana A.; Kennerly, Laura C.; Spear, Linda P.; Robinson, Donita L.

    2014-01-01

    Background Ethanol intoxication affects cognitive performance, contributing to attentional deficits and poor decision making, which may occur via actions in the medial prefrontal cortex (mPFC). mPFC function is modulated by the catecholamines dopamine and norepinephrine. In this study, we examine the acute effects of ethanol on electrically-evoked dopamine release and clearance in the mPFC of anaesthetized rats naïve to alcohol or chronically exposed to alcohol during adolescence. Methods Dopamine release and clearance was evoked by electrical stimulation of the VTA and measured in the mPFC of anaesthetized rats with fast-scan cyclic voltammetry. In Experiments 1 and 2, effects of a high dose of ethanol (4g/kg, i.p.) on dopamine neurotransmission in the mPFC of ethanol-naïve rats and rats given ethanol exposure during adolescence were investigated. Effects of cumulative dosing of ethanol (0.5–4g/kg) on the dopamine release and clearance were investigated in Experiment 3. Experiment 4 studied effects of ethanol locally applied to the ventral tegmental area (VTA) on the dopamine neurotransmission in the mPFC of ethanol-naïve rats. Results A high dose of ethanol decreased evoked dopamine release within 10 min of administration in ethanol-naïve rats. When tested via cumulative dosing from 0.5–4g/kg, both 2 and 4g/kg ethanol inhibited evoked dopamine release in the mPFC of ethanol-naïve rats, while 4g/kg ethanol also slowed dopamine clearance. A similar effect on electrically-evoked dopamine release in the mPFC was observed after infusion of ethanol into the VTA. Interestingly, intermittent ethanol exposure during adolescence had no effect on observed changes in mPFC dopamine release and clearance induced by acute ethanol administration. Conclusions Taken together, these data describe ethanol-induced reductions in the dynamics of VTA-evoked mPFC dopamine release and clearance, with the VTA contributing to the attenuation of evoked mPFC dopamine release induced

  1. Acute effects of ethanol on renal folate clearance in rats

    SciTech Connect

    Eisenga, B.H.; McMartin, K.E.

    1986-03-05

    Studies of the renal clearance of folic acid in primates demonstrate net reabsorption of folate by a saturable system. The acute administration of ethanol to rats causes a significant increase in urinary folate excretion. The mechanism for this effect is unknown and thus the effect of acute administration of ethanol on the renal absorption and urinary clearance of folate was studied in rats. Folic acid was administered to male Sprague-Dawley rats via continuous intravenous infusion in doses ranging from 3-75 micromoles/kg and renal clearance relative to inulin was determined. The effects of various dose levels of ethanol on these parameters were then determined. At a dose of 15 micromoles/kg, the renal clearance of folate relative to that of inulin was about 0.65 mg/min. At a plasma ethanol level about 100 mg/dl, the renal clearance of folate was not markedly altered. These results suggests that there is net reabsorption of folate in the rat kidney and that moderate doses of ethanol have little effect on renal effect on renal folate reabsorption.

  2. Pulmonary function and clearance after prolonged sulfuric acid aerosol exposure

    SciTech Connect

    Ives, P.J. ); Gerrity, T.R.; DeWitt, P.; Folinsbee, L.J. )

    1991-03-15

    The authors studied pulmonary function and clearance responses after a 4 H exposure to 75-100 {mu}g/m{sup 3} sulfuric acid aerosol (SAA). Healthy subjects, who exercised for 30 min/H at ventilation of about 25 L/min, were exposed once to clean air and once to SAA. Oral hygiene and acidic juice gargle were used to minimize oral ammonia. Lung function tests, including spirometry, plethysmography, and partial flow-volume (PEFV) curves were performed before and after exposure. Clearance of 99m-Technetium labeled iron oxide was assessed after each exposure. The first moment of fractional tracheobronchial retention (M1TBR), after correcting for 24 H retention and normalizing to time zero, was used as an index of clearance. There were no significant changes in lung volumes, airways resistance, or maximum expiratory flows after SAA exposure. Flow at 40% of total lung capacity on PEFV curves decreased 17% (NS) after SAA exposure. Tracheobronchial clearance was accelerated after a single exposure to SAA; M1TBR decreased from 73 {plus minus} 5 min (air) to 69 {plus minus} 5 min (SAA). These results suggest that acute prolonged exposure to low levels of SAA has minimal effects on lung mechanics in healthy subjects but does produce a modest acceleration of particle clearance.

  3. TREM2 deficiency reduces the efficacy of immunotherapeutic amyloid clearance.

    PubMed

    Xiang, Xianyuan; Werner, Georg; Bohrmann, Bernd; Liesz, Arthur; Mazaheri, Fargol; Capell, Anja; Feederle, Regina; Knuesel, Irene; Kleinberger, Gernot; Haass, Christian

    2016-01-01

    Immunotherapeutic approaches are currently the most advanced treatments for Alzheimer's disease (AD). Antibodies against amyloid β-peptide (Aβ) bind to amyloid plaques and induce their clearance by microglia via Fc receptor-mediated phagocytosis. Dysfunctions of microglia may play a pivotal role in AD pathogenesis and could result in reduced efficacy of antibody-mediated Aβ clearance. Recently, heterozygous mutations in the triggering receptor expressed on myeloid cells 2 (TREM2), a microglial gene involved in phagocytosis, were genetically linked to late onset AD Loss of TREM2 reduces the ability of microglia to engulf Aβ. We have now investigated whether loss of TREM2 affects the efficacy of immunotherapeutic approaches. We show that anti-Aβ antibodies stimulate Aβ uptake and amyloid plaque clearance in a dose-dependent manner in the presence or absence of TREM2. However, TREM2-deficient N9 microglial cell lines, macrophages as well as primary microglia showed significantly reduced uptake of antibody-bound Aβ and as a consequence reduced clearance of amyloid plaques. Titration experiments revealed that reduced efficacy of amyloid plaque clearance by Trem2 knockout cells can be compensated by elevating the concentration of therapeutic antibodies. PMID:27402340

  4. Investigation on the Dynamic Performance of the Tripod-Ball Sliding Joint with Clearance in a CRANK-SLIDER Mechanism. Part 1. Theoretical and Experimental Results

    NASA Astrophysics Data System (ADS)

    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.

  5. Impairment of aminopyrine clearance in aspirin-damaged canine gastric mucosa

    SciTech Connect

    Miller, T.A.; Henagan, J.M.; Loy, T.M.

    1983-09-01

    Using an in vivo canine chambered stomach preparation, the clearance of (/sup 14/C)aminopyrine across mucosa when intravenously infused and the back-diffusion of this substance from gastric lumen to mucosa when topically applied to gastric epithelium were evaluated in aspirin-damaged gastric epithelium. In mucosa damaged by either 20 mM or 40 mM aspirin, the recovery of (/sup 14/C)aminopyrine, when topically mixed with acid (pH . 1.1) perfusate solution, was not significantly different from nondamaged control mucosa. In addition, the degree of ''trapping'' of this substance from back-diffusion was not different in damaged mucosa from that observed in nondamaged epithelium. In contrast, when (/sup 14/C)aminopyrine was intravenously infused, its clearance was significantly impaired in aspirin-damaged mucosa when compared with control studies, as evidenced by the increased ''trapping'' of this substance in injured epithelium. These findings indicate that movement of aminopyrine from plasma to gastric lumen is impaired in damaged epithelium, making the aminopyrine clearance technique an unreliable method to accurately measure absolute gastric blood flow in this experimental setting.

  6. Determination of drug absorption rate in time-variant disposition by direct deconvolution using beta clearance correction and end-constrained non-parametric regression.

    PubMed

    Neelakantan, S; Veng-Pedersen, P

    2005-11-01

    A novel numerical deconvolution method is presented that enables the estimation of drug absorption rates under time-variant disposition conditions. The method involves two components. (1) A disposition decomposition-recomposition (DDR) enabling exact changes in the unit impulse response (UIR) to be constructed based on centrally based clearance changes iteratively determined. (2) A non-parametric, end-constrained cubic spline (ECS) input response function estimated by cross-validation. The proposed DDR-ECS method compensates for disposition changes between the test and the reference administrations by using a "beta" clearance correction based on DDR analysis. The representation of the input response by the ECS method takes into consideration the complex absorption process and also ensures physiologically realistic approximations of the response. The stability of the new method to noisy data was evaluated by comprehensive simulations that considered different UIRs, various input functions, clearance changes and a novel scaling of the input function that includes the "flip-flop" absorption phenomena. The simulated input response was also analysed by two other methods and all three methods were compared for their relative performances. The DDR-ECS method provides better estimation of the input profile under significant clearance changes but tends to overestimate the input when there were only small changes in the clearance.

  7. Comparison of clearance and arteriovenous extraction techniques for measurements of renal hemodynamic functions

    SciTech Connect

    Katzberg, R.W.; Pabico, R.C.; Morris, T.W.; Hayakawa, K.; McKenna, B.A.; Ventura, J.A.; Fischer, H.W.

    1986-12-01

    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.

  8. Direct measurement of first-pass ileal clearance of a bile acid in humans

    SciTech Connect

    Galatola, G.; Jazrawi, R.P.; Bridges, C.; Joseph, A.E.; Northfield, T.C. )

    1991-04-01

    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%).

  9. Natural History of Helicobacter pylori Infection in Mexican Schoolchildren: Incidence and Spontaneous Clearance

    PubMed Central

    Duque, Ximena; Vilchis, Jenny; Mera, Robertino; Trejo-Valdivia, Belem; Goodman, Karen J.; Mendoza, Maria-Eugenia; Navarro, Fabiola; Roque, Victoria; Moran, Segundo; Torres, Javier; Correa, Pelayo

    2013-01-01

    Objectives The aim of the present study was to estimate the incidence and spontaneous clearance rate of Helicobacter pylori infection and the effect of some variables on these outcomes in schoolchildren. Methods From May 2005 to December 2010, 718 schoolchildren enrolled in 3 public boarding schools in Mexico City participated in the follow-up. At the beginning of the study and every 6 months thereafter, breath samples were taken to detect H pylori infection; blood samples and anthropometric measurements were taken to evaluate nutritional status. Data on sociodemographic characteristics were collected. Results The prevalence of H pylori infection was 38%. The incidence rate was 6.36%/year. Schoolchildren with anemia or iron deficiency at the beginning of the study (who received iron supplements) showed a higher infection acquisition rate than those with normal iron nutritional status, hazard ratio (HR) 12.52 (95% confidence interval [CI] 4.01%–39.12%), P <0.001 and HR 2.05 (95% CI 1.09%–3.87%), P = 0.027, respectively. The spontaneous clearance rate of the infection was 4.74%/year. The spontaneous clearance rate was higher in children who had iron deficiency (who received iron supplements), HR 5.02 (95% CI 1.33%–18.99%), P = 0.017, compared with those with normal nutritional iron status. It was lower in schoolchildren with ≥2 siblings compared with schoolchildren with 1 or no siblings, HR 0.23 (95% CI 0.08%–0.63%), P = 0.004. Conclusions H pylori infection status is dynamic in schoolchildren. Variables related to health status and infection transmission, such as iron status and number of siblings, are important for the incidence and spontaneous clearance of H pylori infection. PMID:22227999

  10. Retention and clearance of stainless steel shieldgas welding fumes in rat lungs.

    PubMed

    Kalliomäki, P L; Tuomisaari, M; Lakomaa, E L; Kalliomäki, K; Kivelä, R

    1983-09-01

    The use of metal inert gas (MIG) stainless steel (SS) welding techniques is rapidly increasing. The possible health hazards of MIG/SS welding fumes are not known; more attention has been paid to manual metal arc (MMA) welding. In this study, 52 male Wistar rats were exposed to MIG/SS welding fumes generated by an automatic welding device for "nose only" exposure. For the retention study, the duration of exposure was one hour per workday for 1,2,3, and 4 weeks. For the clearance study, the duration was 4 weeks, and the follow-up period was 106 days. The retention and clearance of the alloyed metals of SS (chromium (Cr), manganese (Mn), nickel (Ni] and iron were studied in the rats' lungs, and the results were compared with the corresponding results of MMA/SS welding. The multielement chemical analysis was made using instrumental neutron activation analysis (INAA); the concentration of exogeneous iron (Feex) was determined by a magnetic measuring method. Feex and Cr were retained in the ratio expected; Mn, Ni and total Fe were retained slower than expected. The total Fe did not clear at all even though Feex cleared with the half-time of 50 d which corresponded well with that of pure magnetite. The accumulation of Cr in the lungs was very high: it cleared with the half-time of 240 d. The clearance patterns of Mn and Ni were very similar. They followed a double exponential model with half-times of 2 d and 125 d for Mn, and 3 d and 85 d for Ni. The results indicated that even though the retention patterns for MMA and MIG welding fumes were very similar, the clearances differed very much.

  11. HPT Clearance Control: Intelligent Engine Systems-Phase 1

    NASA Technical Reports Server (NTRS)

    2005-01-01

    The following work has been completed to satisfy the Phase I Deliverables for the "HPT Clearance Control" project under NASA GRC's "Intelligent Engine Systems" program: (1) Need for the development of an advanced HPT ACC system has been very clearly laid out, (2) Several existing and potential clearance control systems have been reviewed, (3) A scorecard has been developed to document the system, performance (fuel burn, range, payload, etc.), thermal, and mechanical characteristics of the existing clearance control systems, (4) Engine size and flight cycle selection for the advanced HPT ACC system has been reviewed with "large engine"/"long range mission" combination showing the most benefit, (5) A scoring criteria has been developed to tie together performance parameters for an objective, data driven comparison of competing systems, and (6) The existing HPT ACC systems have been scored based on this scoring system.

  12. Impaired lipid clearance in patients with previous acute pancreatitis.

    PubMed Central

    Guzmán, S; Nervi, F; Llanos, O; León, P; Valdivieso, V

    1985-01-01

    Fasting serum triglycerides were measured in 52 patients who had sustained an attack of pancreatitis (gall stone related 33, alcoholism six) at least six months earlier. Several patients (23%) had raised fasting serum triglycerides, with a type IV phenotype in all but one patient. The 40 patients with normal fasting serum triglycerides received an oral load of 100 g sunflower oil to compare their clearance of dietary triglycerides with that of a control group of 54 subjects. The clearance of ingested triglycerides was significantly impaired in the patients - irrespective of the presumed aetiological factor, or clinical condition associated with pancreatitis - compared with the clearance in controls. A triglyceride tolerance test is the only way to detect those patients in whom a future attack of pancreatitis may be precipitated by a diet rich in fat, or endogenous over production of triglycerides as after an alcoholic debauch. PMID:4029716

  13. Tumor Presence Induces Global Immune Changes and Enhances Nanoparticle Clearance.

    PubMed

    Kai, Marc P; Brighton, Hailey E; Fromen, Catherine A; Shen, Tammy W; Luft, J Christopher; Luft, Yancey E; Keeler, Amanda W; Robbins, Gregory R; Ting, Jenny P Y; Zamboni, William C; Bear, James E; DeSimone, Joseph M

    2016-01-26

    Long-circulating nanoparticles are essential for increasing tumor accumulation to provide therapeutic efficacy. While it is known that tumor presence can alter the immune system, very few studies have explored this impact on nanoparticle circulation. In this report, we demonstrate how the presence of a tumor can change the local and global immune system, which dramatically increases particle clearance. We found that tumor presence significantly increased clearance of PRINT hydrogel nanoparticles from the circulation, resulting in increased accumulation in the liver and spleen, due to an increase in M2-like macrophages. Our findings highlight the need to better understand interactions between immune status and nanoparticle clearance, and suggest that further consideration of immune function is required for success in preclinical and clinical nanoparticle studies.

  14. Inefficient clearance of myelin debris by microglia impairs remyelinating processes

    PubMed Central

    Lampron, Antoine; Larochelle, Antoine; Laflamme, Nathalie; Préfontaine, Paul; Plante, Marie-Michèle; Sánchez, Maria Gabriela; Yong, V. Wee; Stys, Peter K.; Tremblay, Marie-Ève

    2015-01-01

    An imbalance between remyelinating and demyelinating rates underlies degenerative processes in demyelinating diseases such as multiple sclerosis. An optimal therapeutic strategy would be to stimulate remyelination while limiting demyelination. Although accumulation of myelin debris impairs remyelination, the mechanisms regulating the clearance of such debris by mononuclear phagocytic cells are poorly understood. We demonstrate that after cuprizone intoxication, CCR2-dependent infiltration of mouse bone marrow–derived cells is abundant in demyelinating areas, but that these cells do not impact demyelination. However, in CX3CR1-deficient mice, the clearance of myelin debris by microglia was blocked greatly, affecting the integrity of the axon and myelin sheaths and thus preventing proper remyelination. These results highlight the crucial role played by CX3CR1 in myelin removal and show that there can be no efficient remyelination after a primary demyelinating insult if myelin clearance by microglia is impaired. PMID:25779633

  15. Improving mucociliary clearance in chronic obstructive pulmonary disease.

    PubMed

    Bhowmik, Angshu; Chahal, Kamaljeet; Austin, Gillian; Chakravorty, Indranil

    2009-04-01

    Patients with COPD usually experience mucus hypersecretion as a result of airway inflammation and response to noxious stimuli. These in turn lead to worsening airway resistance, impaired airflow, increased work of breathing, dyspnoea and exercise intolerance. Mucus hypersecretion may also lead to increased exacerbations and poor health related quality of life (HRQL). Institution based pulmonary rehabilitation programs incorporating airway clearance techniques have been shown to improve HRQL, reduce dyspnoea and improve exercise tolerance but are often difficult to provide due to restricted accessibility and resource implications. This review examines the current evidence base and best clinical practice in the area of airway clearance. Mechanical devices such as the flutter valves, positive end expiratory pressure and high frequency chest wall oscillation (HFCWO) may be able to provide the benefits of improved airway clearance in the patient's home potentially with reduced demands on healthcare resources.

  16. A new paradigm in respiratory hygiene: modulating respiratory secretions to contain cough bioaerosol without affecting mucus clearance

    PubMed Central

    Zayas, Gustavo; Valle, Juan C; Alonso, Mauricio; Alfaro, Henry; Vega, Daniel; Bonilla, Gloria; Reyes, Miguel; King, Malcolm

    2007-01-01

    Background Several strategies and devices have been designed to protect health care providers from acquiring transmissible respiratory diseases while providing care. In modulating the physical characteristics of the respiratory secretions to minimize the aerosolization that facilitates transmission of airborne diseases, a fundamental premise is that the prototype drugs have no adverse effect on the first line of respiratory defense, clearance of mucus by ciliary action. Methods To assess and demonstrate the primary mechanism of our mucomodulators (XLs), we have built our evidence moving from basic laboratory studies to an ex-vivo model and then to an in-vivo large animal model. We exposed anesthetized dogs without hypersecretion to different dose concentrations of aerosolized XL "B", XL "D" and XL "S". We assessed: cardio-respiratory pattern, tracheal mucus clearance, airway patency, and mucus viscoelastic changes. Results Exposure of frog palate mucus to XLs did not affect the clearance of mucus by ciliary action. Dogs maintained normal cardio-respiratory pattern with XL administration. Tracheal mucociliary clearance in anesthetized dogs indicated a sustained 40% mean increase. Tracheal mucus showed increased filance, and there was no mucus retention in the airways. Conclusion The ex-vivo frog palate and the in-vivo mammalian models used in this study, appear to be appropriate and complement each other to better assess the effects that our mucomodulators exert on the mucociliary clearance defence mechanism. The physiological function of the mucociliary apparatus was not negatively affected in any of the two epithelial models. Airway mucus crosslinked by mucomodulators is better cleared from an intact airway and normally functioning respiratory system, either due to enhanced interaction with cilia or airflow-dependent mechanisms. Data obtained in this study allow us to assure that we have complied with the fundamental requirement criteria established in the initial

  17. Effect of mouse strain as a background for Alzheimer’s disease models on the clearance of amyloid-β

    PubMed Central

    Qosa, Hisham; Kaddoumi, Amal

    2016-01-01

    Novel animal models of Alzheimer’s disease (AD) are relentlessly being developed and existing ones are being fine-tuned; however, these models face multiple challenges associated with the complexity of the disease where most of these models do not reproduce the full phenotypical disease spectrum. Moreover, different AD models express different phenotypes that could affect their validity to recapitulate disease pathogenesis and/or response to a drug. One of the most important and understudied differences between AD models is differences in the phenotypic characteristics of the background species. Here, we used the brain clearance index (BCI) method to investigate the effect of strain differences on the clearance of amyloid β (Aβ) from the brains of four mouse strains. These mouse strains, namely C57BL/6, FVB/N, BALB/c and SJL/J, are widely used as a background for the development of AD mouse models. Findings showed that while Aβ clearance across the blood-brain barrier (BBB) was comparable between the 4 strains, levels of LRP1, an Aβ clearance protein, was significantly lower in SJL/J mice compared to other mouse strains. Furthermore, these mouse strains showed a significantly different response to rifampicin treatment with regard to Aβ clearance and effect on brain level of its clearance-related proteins. Our results provide for the first time an evidence for strain differences that could affect ability of AD mouse models to recapitulate response to a drug, and opens a new research avenue that requires further investigation to successfully develop mouse models that could simulate clinically important phenotypic characteristics of AD. PMID:27478623

  18. Genetic Variation in the IL-6 and HLA-DQB1 Genes Is Associated with Spontaneous Clearance of Hepatitis C Virus Infection

    PubMed Central

    Waldron, Paul Ravi; Belitskaya-Lévy, Ilana; Chary, Aarthi; Won, Johann; Winters, Mark; Monto, Alexander; Ryan, James; Lazzeroni, Laura C.; Holodniy, Mark

    2016-01-01

    Background. Millions of people are infected with hepatitis C virus (HCV) worldwide and 30% spontaneously clear the infection. Reasons for HCV clearance without antiviral treatment are not well understood. Methods. Blood was collected for DNA analysis from patients with chronic HCV infection or evidence of spontaneous clearance. To overcome anticipated limitations of small sample size, primary analyses consisted of a candidate gene analysis of 12 preselected genes based on known association with host immunologic response to HCV infection. To further reduce the impact of multiple testing on power, a single likelihood ratio test was conducted for each gene using all associated SNPs assayed on the Illumina Quad 610/660W chip. Step-down permutation methods were used to adjust for multiple testing in all analyses. Results. Ninety-five and 62 patients with HCV chronic infection or spontaneous clearance, respectively, were included for analysis. HLA-DQB1 (p = 1.76⁎10−5) and IL-6 (p = 0.0007) genes were significantly associated with spontaneous HCV clearance. IL-28B was not significantly associated with spontaneous clearance (p = 0.17). Conclusion. Our whole-gene analytic strategy identified a previously unreported association of IL-6 with spontaneous clearance of HCV infection. We also confirmed the finding that HLA-DQB1 is associated with spontaneous resolution of HCV infection. PMID:27340680

  19. Effect of Internal Clearance on Load Distribution and Life of Radially Loaded Ball and Roller Bearings

    NASA Technical Reports Server (NTRS)

    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.

  20. Effects of desipramine on norepinephrine clearance in congestive heart failure

    SciTech Connect

    Clemson, B.; Baily, R.G.; Davis, D.; Zelis, R. )

    1990-08-01

    Elevated plasma norepinephrine (NE) in congestive heart failure (CHF) is caused by increased NE spillover and decreased NE clearance. To evaluate the effects of neuronal uptake blockade on NE clearance, we studied NE kinetics during steady-state infusions of (3H)NE, before and after oral desipramine (DMI, 50 mg) in 11 patients with CHF and 8 normal volunteers. Baseline plasma NE was greater in the CHF group (637 +/- 56 vs. 271 +/- 32 pg/ml; P less than 0.001), NE clearance was lower in CHF (1.31 +/- 0.21 vs. 1.94 +/- 0.17 l.min-1.m-2; P = 0.026), and NE spillover was greater in CHF (4.71 +/- 0.78 vs. 3.04 +/- 0.35 nmol.min-1.m-2, P = 0.054). After DMI, plasma NE rose significantly in CHF (778 +/- 67; P = 0.008), and NE clearance decreased further in CHF (0.97 +/- 0.16; P = 0.024), but neither changed in normal subjects. NE spillover did not change in either group. There appears to be an enhanced effect of DMI on NE clearance in CHF patients. Two general mechanisms may be responsible for this finding, an increased concentration of drug, possibly caused by a decreased volume of distribution, and an increased sensitivity of neuronal amine pumps to DMI. Both mechanisms may reflect a more general abnormality of clearance of drugs and hormones related to abnormalities of tissue perfusion in CHF.

  1. Acute exposure to acid fog. Effects on mucociliary clearance

    SciTech Connect

    Laube, B.L.; Bowes, S.M. III; Links, J.M.; Thomas, K.K.; Frank, R. )

    1993-05-01

    Submicrometric sulfuric acid (H2SO4) aerosol can affect mucociliary clearance without eliciting irritative symptoms or changes in pulmonary function. The effect of larger fog droplets containing H2SO4 on mucociliary clearance is unknown. We quantified mucociliary clearance from the trachea (n = 4) and small airways (n = 7) of young healthy male adults after an acute exposure to H2SO4 fog (MMAD = 10.3 microns; pH = 2.0; liquid water content = 481 +/- 65 mg/m3; osmolarity = 30 mOsm). Acid fog (AF) or saline fog (SF) (10.9 microns; 492 +/- 116 mg/m3; 30 mOsm) was administered for 40 min of unencumbered breathing (no mouth-piece) at rest and for 20 min of exercise sufficient to produce oronasal breathing. Fog exposures were followed by a methacholine (MCh) challenge (a measure of airway reactivity) or inhalation of technetium-99M radioaerosol (MMAD = 3.4 microns) on 2 study days each. Changes in symptoms and forced ventilatory function were also assessed. Clearance was quantified from computer-assisted analyses of gamma camera images of the lower respiratory tract in terms of %removal/min of the radiolabel from the trachea 25 min after inhalation and from the outer zone of the right lung after 1.9 to 3 h. Symptoms, forced ventilatory function, and MCh response were unaffected by either fog. Tracheal clearance was more rapid in four of four subjects after AF (0.83 +/- 1.58% removal/min) compared with that after SF (-0.54 +/- 0.85% removal/min). Outer zone clearance was more rapid in six of seven subjects after AF (0.22 +/- 0.15% removal/min) compared with that after SF (0.01 +/- 0.09% removal/min).

  2. Myocardial clearance of technetium-99m-teboroxime in reperfused injured canine myocardium

    PubMed Central

    2014-01-01

    Background Recent technical developments using solid-state technology have enabled rapid image acquisition with single photon emission computed tomography (SPECT) and have led to a renewed interest in technetium-99m-teboroxime (Tc-99m-teboroxime) as a myocardial imaging agent. Tc-99m-teboroxime has demonstrated high myocardial extraction, linear myocardial uptake relative to flow even at high flow rates, rapid uptake and clearance kinetics, and differential clearance in the setting of ischemia. However, the myocardial clearance kinetics of Tc-99m-teboroxime in a model of myocardial injury has not been previously reported. Thus, the purposes of this study were to use a canine model of ischemia-reperfusion to (1) compare Tc-99m-teboroxime clearance kinetics in normal and ischemic-reperfused myocardium and (2) assess the utility of Tc-99m-teboroxime clearance kinetics in determining the severity of injury following ischemia-reperfusion. Methods Thirteen dogs underwent left circumflex coronary artery (LCx) occlusion for either 30 min (IR30, n = 6) or 120 min (IR120, n = 7), followed by reperfusion, and finally Tc-99m-teboroxime administration 120 min after reperfusion. Microsphere blood flows were determined at baseline, during occlusion, after reperfusion, and before euthanasia. Post-mortem, area at risk was determined using Evans blue dye, and viability was determined using triphenytetrazolium chloride (TTC) staining. The hearts were then subdivided into 24 pieces and Tc-99m activity was measured in a well counter. Results TTC-determined infarct area as a percentage of total left ventricular myocardium was 1.1% ± 0.3% for the IR30 group and 7.5% ± 2.9% for the IR120 group (p < 0.05). During coronary occlusion, both the IR30 and IR120 groups demonstrated decreases in percent wall thickening in the ischemia-reperfusion zone (IRZ) as compared with the normal zone (NZ). In the IR30 group, percent wall thickening in the IRZ recovered during the

  3. Effect of oral N-acetylcysteine on mucus clearance.

    PubMed

    Millar, A B; Pavia, D; Agnew, J E; Lopez-Vidriero, M T; Lauque, D; Clarke, S W

    1985-07-01

    Oral N-acetylcysteine has been advocated as a mucolytic agent for use in chronic bronchitis. We have investigated the effects of regular use of this drug at a dose of 200 mg thrice daily for 4 weeks in nine patients with chronic bronchitis on lung function, lung mucociliary clearance and sputum viscosity in a controlled, double-blind, crossover study. No significant differences were found in lung function, mucociliary clearance curves or sputum viscosity following treatment with N-acetylcysteine compared to control or placebo measurements.

  4. Use of HμREL Human Coculture System for Prediction of Intrinsic Clearance and Metabolite Formation for Slowly Metabolized Compounds.

    PubMed

    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

  5. Effect of atropine on oral clearance of a radiolabeled sulfur colloid

    SciTech Connect

    LaForce, F.M.; Thompson, B.; Trow, R.

    1984-11-01

    Physical clearance is an important oral defense mechanism against gram-negative rods. The authors describe a simple technique that uses commercially available technetium-99m sulfur colloid to measure oral clearance. Technetium-99m sulfur colloid was sprayed into the mouth, and clearance was measured as the percent decrease in radiolabel counts over 2 hours using a radioisotope camera. Results using this technique compared favorably with clearance data using Tc-99m radiolabeled Escherichia coli. Atropine significantly decreased oral clearance rates of the colloid. Decreased clearance may be an important risk factor in the development of gram-negative rod colonization in hospitalized patients. 15 references, 3 figures.

  6. Effects of bearing outer clearance on the dynamic behaviours of the full floating ring bearing supported turbocharger rotor

    NASA Astrophysics Data System (ADS)

    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.

  7. 46 CFR 61.20-23 - Tailshaft clearance; bearing weardown.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Tailshaft clearance; bearing weardown. 61.20-23 Section...; bearing weardown. (a) Water lubricated bearings, other than rubber, must be rebushed as follows: (1) Where the propelling machinery is located amidship, the after stern tube bearing must be rebushed when it...

  8. 46 CFR 61.20-23 - Tailshaft clearance; bearing weardown.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Tailshaft clearance; bearing weardown. 61.20-23 Section...; bearing weardown. (a) Water lubricated bearings, other than rubber, must be rebushed as follows: (1) Where the propelling machinery is located amidship, the after stern tube bearing must be rebushed when it...

  9. 46 CFR 61.20-23 - Tailshaft clearance; bearing weardown.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Tailshaft clearance; bearing weardown. 61.20-23 Section...; bearing weardown. (a) Water lubricated bearings, other than rubber, must be rebushed as follows: (1) Where the propelling machinery is located amidship, the after stern tube bearing must be rebushed when it...

  10. Decreased renal clearance of digoxin in chronic congestive heart failure.

    PubMed

    Naafs, M A; van der Hoek, C; van Duin, S; Koorevaar, G; Schopman, W; Silberbusch, J

    1985-01-01

    Renal digoxin clearance was compared in patients suffering from atrial fibrillation with well preserved cardiac function (n = 9; salt intake +/- 170 mmol daily) and patients with chronic congestive heart failure (n = 10; salt intake 50 mmol daily and maintenance treatment with diuretics). There was no difference between the groups concerning digoxin dosage, creatinine clearance, diuresis or sodium excretion in the urine. Digoxin clearance in chronic heart failure proved to be significantly lower than in atrial fibrillation (48 +/- 21 vs 71 +/- 36 ml X min-1, p less than 0.05), and Cdig/Ccreat was similarly reduced at 0.73 +/- 0.15 compared to 1.09 +/- 0.27 (p less than 0.005). Steady state serum digoxin concentration was significantly higher in patients with congestive heart failure (1.44 +/- 0.47 vs 0.87 +/- 0.33 micrograms X 1(-1), p less than 0.01). Chronic congestive heart failure is a state with reduced digoxin clearance by the kidney, which could lead to digoxin intoxication not explicable by overdose, reduced renal function or the effect of interacting drugs. PMID:4007028

  11. 11. MODEL 200 CRANE, GENERAL ARRANGEMENT & CLEARANCES. Colby Steel ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. MODEL 200 CRANE, GENERAL ARRANGEMENT & CLEARANCES. Colby Steel & Engineering Company, Vancouver B.C., Seattle, New York. Two elevations and cab plan. No architect noted, drawn by "Gould." Sheet A2, No. 6365. Scale not given. August 10, 1942. "Proposal no. 318." blueline print - United Engineering Company Shipyard, Crane, 2900 Main Street, Alameda, Alameda County, CA

  12. 30 CFR 57.9330 - Clearance for surface equipment.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Clearance for surface equipment. 57.9330 Section 57.9330 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 Loading, Hauling, and Dumping Safety Devices,...

  13. 30 CFR 56.9330 - Clearance for surface equipment.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Clearance for surface equipment. 56.9330 Section 56.9330 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 Loading, Hauling, and Dumping Safety Devices,...

  14. 33 CFR 118.160 - Vertical clearance gauges.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Vertical clearance gauges. 118.160 Section 118.160 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... repaired. 33 CFR Ch. I (7-1-12 Edition) Coast Guard, DHS...

  15. Highly fluorescent resorcinarene cavitand nanocapsules with efficient renal clearance.

    PubMed

    Mahadevan, Kalpana; Patthipati, Venkata Suresh; Han, Sangbum; Swanson, R James; Whelan, Eoin C; Osgood, Christopher; Balasubramanian, Ramjee

    2016-08-19

    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 × 10(9) M(-1) cm(-1) and 1.5 × 10(8) 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.

  16. Highly fluorescent resorcinarene cavitand nanocapsules with efficient renal clearance.

    PubMed

    Mahadevan, Kalpana; Patthipati, Venkata Suresh; Han, Sangbum; Swanson, R James; Whelan, Eoin C; Osgood, Christopher; Balasubramanian, Ramjee

    2016-08-19

    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 × 10(9) M(-1) cm(-1) and 1.5 × 10(8) 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. PMID:27378394

  17. 30 CFR 57.9306 - Warning devices for restricted clearances.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Warning devices for restricted clearances. 57.9306 Section 57.9306 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...

  18. 30 CFR 57.9306 - Warning devices for restricted clearances.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Warning devices for restricted clearances. 57.9306 Section 57.9306 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...

  19. 30 CFR 57.9306 - Warning devices for restricted clearances.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Warning devices for restricted clearances. 57.9306 Section 57.9306 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...

  20. 30 CFR 57.9306 - Warning devices for restricted clearances.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Warning devices for restricted clearances. 57.9306 Section 57.9306 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...

  1. 30 CFR 57.9306 - Warning devices for restricted clearances.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Warning devices for restricted clearances. 57.9306 Section 57.9306 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...

  2. 48 CFR 801.602-76 - Business clearance review.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Business clearance review. 801.602-76 Section 801.602-76 Federal Acquisition Regulations System DEPARTMENT OF VETERANS AFFAIRS GENERAL DEPARTMENT OF VETERANS AFFAIRS ACQUISITION REGULATION SYSTEM Career Development,...

  3. 75 FR 52798 - State-07, Cryptographic Clearance Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    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...

  4. Highly fluorescent resorcinarene cavitand nanocapsules with efficient renal clearance

    NASA Astrophysics Data System (ADS)

    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.

  5. 48 CFR 952.204-73 - Facility clearance.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... code for the Nuclear Materials Management and Safeguards Reporting System if access to nuclear..., if applicable, appointment of a Materials Control and Accountability Representative; and (7) Access... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false Facility clearance....

  6. 32 CFR 644.522 - Clearance of military scrap.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... PROPERTY REAL ESTATE HANDBOOK Disposal Clearance of Explosive Hazards and Other Contamination from Proposed... determining whether scrap metal will be removed should be the safety of persons coming on the land in question and, secondarily, the prevention of accidents resulting from the sale and/or use of the scrap...

  7. Highly fluorescent resorcinarene cavitand nanocapsules with efficient renal clearance

    NASA Astrophysics Data System (ADS)

    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.

  8. 49 CFR Appendix F to Part 512 - OMB Clearance

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 6 2011-10-01 2011-10-01 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...

  9. 48 CFR 2452.237-75 - Clearance of contractor personnel.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Clearance of contractor personnel. 2452.237-75 Section 2452.237-75 Federal Acquisition Regulations System DEPARTMENT OF HOUSING AND...). The Contractor shall provide the GTR with the names and Social Security numbers of all such...

  10. 77 FR 22831 - Agency Information Collection Activities: Emergency Clearance Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-17

    ... decision at 76 FR 54700. The current information collection request (ICR) requests approval for the public... for Emergency Clearance When we originally published the banning decision rules at 76 FR 54700, the..., and other incoming documents, or to fulfill requests for reports. This would bottleneck or...

  11. 33 CFR 151.1508 - Revocation of clearance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID SUBSTANCES, GARBAGE, MUNICIPAL OR COMMERCIAL WASTE, AND BALLAST WATER Ballast Water Management for Control of Nonindigenous Species in the Great Lakes and Hudson River § 151.1508 Revocation of clearance. A COTP may request the District Director of Customs...

  12. 33 CFR 151.1508 - Revocation of clearance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID SUBSTANCES, GARBAGE, MUNICIPAL OR COMMERCIAL WASTE, AND BALLAST WATER Ballast Water Management for Control of Nonindigenous Species in the Great Lakes and Hudson River § 151.1508 Revocation of clearance. A COTP may request the District Director of Customs...

  13. 33 CFR 151.1508 - Revocation of clearance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID SUBSTANCES, GARBAGE, MUNICIPAL OR COMMERCIAL WASTE, AND BALLAST WATER Ballast Water Management for Control of Nonindigenous Species in the Great Lakes and Hudson River § 151.1508 Revocation of clearance. A COTP may request the District Director of Customs...

  14. 33 CFR 151.1508 - Revocation of clearance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) POLLUTION VESSELS CARRYING OIL, NOXIOUS LIQUID SUBSTANCES, GARBAGE, MUNICIPAL OR COMMERCIAL WASTE, AND BALLAST WATER Ballast Water Management for Control of Nonindigenous Species in the Great Lakes and Hudson River § 151.1508 Revocation of clearance. A COTP may request the District Director of Customs...

  15. 33 CFR 118.160 - Vertical clearance gauges.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... repaired. 33 CFR Ch. I (7-1-13 Edition) Coast Guard, DHS ... BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.160 Vertical clearance gauges. (a) When necessary for reasons of safety of navigation, the District Commander may require or authorize the installation...

  16. 33 CFR 118.160 - Vertical clearance gauges.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... repaired. 33 CFR Ch. I (7-1-14 Edition) Coast Guard, DHS ... BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.160 Vertical clearance gauges. (a) When necessary for reasons of safety of navigation, the District Commander may require or authorize the installation...

  17. The Genesis and Justification of Forms Clearance Procedures.

    ERIC Educational Resources Information Center

    Duncan, Joseph W.; Wallman, Katherine K.

    The central reports clearance authority of the Federal Government is a legislatively sanctioned mechanism for applying constraints on the conduct of statistical and other data gathering activities by Federal Departments and agencies and other research parties funded by Federal government contracts. General recommendations for improving the overall…

  18. Model 200 crane, general arrangement & clearances. Colby Steel & ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Model 200 crane, general arrangement & clearances. Colby Steel & Engineering Company, Vancouver B.C., Seattle, New York. Two elevations and cab plan. No architect noted, drawn by Gould. Sheet A2, no 6365. Scaled not given. August 10, 1942. Proposal no. 318. - United Engineering Company Shipyard, Crane, 2900 Main Street, Alameda, Alameda County, CA

  19. 78 FR 77027 - Overhead Clearance (Air-Draft) Accidents

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-20

    ... Federal Register (73 FR 3316). Description of Petition for Rulemaking In its Petition for Rulemaking dated... meeting notice (78 FR 49543, 49544, August 14, 2013) and copy of Task 13-10, Recommendation to Establish... SECURITY Coast Guard 33 CFR Parts 117, 161, and 164 46 CFR Part 4 Overhead Clearance (Air-Draft)...

  20. [Airway clearance techniques in chronic obstructive pulmonary syndrome : 2011 update].

    PubMed

    Opdekamp, C

    2011-09-01

    For many years the airway clearance techniques used in chest physical therapy were assimilated with the singular technique of postural drainage, percussions and vibrations. However the side effects and counter indications and the lack of scientific proof regarding this technique have forced reflection and development of other techniques more comfortable and without deleterious effects. If all these techniques show a high efficiency in terms of improved mucociliary clearance, the literature is unanimous on how little effect these techniques have in the short and the long-term with regards to lung function and arterial blood gases. In view of the scientific literature, it is clear that the airway clearance techniques don't have the same recognition concerning their efficiency in all obstructive pulmonary diseases. As the cornerstone in the management of cystic fibrosis, the efficiency of the bronchial hygiene techniques are in general poorly documented in the management of the non-cystic fibrosis bronchiectasis, bronchitis or emphysema. The use of the chest physical therapy seems more to do with the interpretation of the imagery and symptomatology. The airway clearance techniques should be individualised according to symptoms, the amount of expectorated mucus and the objectives signs of secretions retention or subjective signs of difficulty expectorating secretions with progression of the disease. PMID:22034769

  1. Induction of bilirubin clearance by the constitutive androstane receptor (CAR).

    PubMed

    Huang, Wendong; Zhang, Jun; Chua, Steven S; Qatanani, Mohammed; Han, Yunqing; Granata, Riccarda; Moore, David D

    2003-04-01

    Bilirubin clearance is one of the numerous important functions of the liver. Defects in this process result in jaundice, which is particularly common in neonates. Elevated bilirubin levels can be decreased by treatment with phenobarbital. Because the nuclear hormone receptor constitutive androstane receptor (CAR) mediates hepatic effects of this xenobiotic inducer, we hypothesized that CAR could be a regulator of bilirubin clearance. Activation of the nuclear hormone receptor CAR increases hepatic expression of each of five components of the bilirubin-clearance pathway. This induction is absent in homozygous CAR null mice but is observed in mice expressing human CAR instead of mouse CAR. Pretreatment with xenobiotic inducers markedly increases the rate of clearance of an exogenous bilirubin load in wild-type but not CAR knockout animals. Bilirubin itself can also activate CAR, and mice lacking CAR are defective in clearing chronically elevated bilirubin levels. Unexpectedly, CAR expression is very low in livers of neonatal mice and humans. We conclude that CAR directs a protective response to elevated bilirubin levels and suggest that a functional deficit of CAR activity may contribute to neonatal jaundice. PMID:12644704

  2. 49 CFR Appendix F to Part 512 - OMB Clearance

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 6 2014-10-01 2014-10-01 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...

  3. 49 CFR Appendix F to Part 512 - OMB Clearance

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 6 2013-10-01 2013-10-01 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...

  4. Influence of clearance model on numerical simulation of centrifugal pump

    NASA Astrophysics Data System (ADS)

    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.

  5. OMB Forms Clearance: Restrictions on Educational Research Plans.

    ERIC Educational Resources Information Center

    Coan, Donald L.

    Forms Clearance standards and regulations are used by the Office of Management and Budget and by the Education Division of the Department of Health, Education and Welfare in order to upgrade the quality of federal data collection, to minimize cost, minimize reporting burden, maximize utility, and to protect the privacy rights of respondents.…

  6. 50 CFR 14.52 - Clearance of imported wildlife.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 1 2014-10-01 2014-10-01 false Clearance of imported wildlife. 14.52 Section 14.52 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR TAKING, POSSESSION, TRANSPORTATION, SALE, PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE...

  7. 50 CFR 14.52 - Clearance of imported wildlife.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 1 2012-10-01 2012-10-01 false Clearance of imported wildlife. 14.52 Section 14.52 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR TAKING, POSSESSION, TRANSPORTATION, SALE, PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE...

  8. 50 CFR 14.52 - Clearance of imported wildlife.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 1 2013-10-01 2013-10-01 false Clearance of imported wildlife. 14.52 Section 14.52 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR TAKING, POSSESSION, TRANSPORTATION, SALE, PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE...

  9. 50 CFR 14.52 - Clearance of imported wildlife.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 1 2010-10-01 2010-10-01 false Clearance of imported wildlife. 14.52 Section 14.52 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR TAKING, POSSESSION, TRANSPORTATION, SALE, PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE...

  10. 50 CFR 14.53 - Detention and refusal of clearance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... § 14.93 or § 14.94, or penalties assessed against the importer or exporter under 50 CFR part 11. This... 50 Wildlife and Fisheries 1 2010-10-01 2010-10-01 false Detention and refusal of clearance. 14.53 Section 14.53 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE...

  11. 50 CFR 14.52 - Clearance of imported wildlife.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 1 2011-10-01 2011-10-01 false Clearance of imported wildlife. 14.52 Section 14.52 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR TAKING, POSSESSION, TRANSPORTATION, SALE, PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE...

  12. Celllular Uptake and Clearance of TIO2 Nanoparticles

    EPA Science Inventory

    Differential rates of cellular uptake and clearance of engineered nanomaterials may influence the propensity for tissue accumulation under chronic exposure conditions. A retinal pigment epithelial cell line (ARPE-19) was used to investigate 1) if Ti02 (Degussa, P25) nanoparticles...

  13. 23 CFR Appendix B to Part 1327 - OMB Clearance

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false OMB Clearance B Appendix B to Part 1327 Highways NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PROCEDURES FOR PARTICIPATING IN AND RECEIVING INFORMATION FROM THE NATIONAL DRIVER REGISTER PROBLEM DRIVER POINTER SYSTEM Pt....

  14. 19 CFR 122.158 - Other entry and clearance requirements.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Other entry and clearance requirements. 122.158 Section 122.158 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Flights to and From Cuba § 122.158 Other entry...

  15. 46 CFR 61.20-23 - Tailshaft clearance; bearing weardown.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... PERIODIC TESTS AND INSPECTIONS Periodic Tests of Machinery and Equipment § 61.20-23 Tailshaft clearance... the propelling machinery is located amidship, the after stern tube bearing must be rebushed when it is... propelling machinery is located aft, the after stern tube bearing must be rebushed when weardown is 1.6...

  16. 46 CFR 61.20-23 - Tailshaft clearance; bearing weardown.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... PERIODIC TESTS AND INSPECTIONS Periodic Tests of Machinery and Equipment § 61.20-23 Tailshaft clearance... the propelling machinery is located amidship, the after stern tube bearing must be rebushed when it is... propelling machinery is located aft, the after stern tube bearing must be rebushed when weardown is 1.6...

  17. 49 CFR Appendix F to Part 512 - OMB Clearance

    Code of Federal Regulations, 2010 CFR

    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...

  18. 19 CFR 148.23 - Examination and clearance of baggage.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Collection of Duties and Taxes § 148.23 Examination and clearance of baggage. (a) Articles free of duty. The... United States may examine and pass, without limitation as to value, the following articles in such baggage or otherwise accompanying such person: (1) All articles which are for the personal or...

  19. 19 CFR 148.23 - Examination and clearance of baggage.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Collection of Duties and Taxes § 148.23 Examination and clearance of baggage. (a) Articles free of duty. The... United States may examine and pass, without limitation as to value, the following articles in such baggage or otherwise accompanying such person: (1) All articles which are for the personal or...

  20. A Novel Technique of Contrast-Enhanced Optical Coherence Tomography Imaging in Evaluation of Clearance of Lipids in Human Tears

    PubMed Central

    Napoli, Pietro Emanuele; Coronella, Franco; Satta, Giovanni Maria; Fossarello, Maurizio

    2014-01-01

    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

  1. Lung clearance and retention of toner, utilizing a tracer technique, during chronic inhalation exposure in rats.

    PubMed

    Bellmann, B; Muhle, H; Creutzenberg, O; Dasenbrock, C; Kilpper, R; MacKenzie, J C; Morrow, P; Mermelstein, R

    1991-08-01

    Male and female F-344 rats were exposed to 6 hr/day, 5 days/week for up to 24 months to a special test toner at 0, 1, 4, and 16 mg/m3, TiO2 at 5 mg/m3, or SiO2 at 1 mg/m3 by the inhalation route. 59Fe-labeled iron oxide and 85Sr-labeled polystyrene particles were periodically inhaled by the nose-only route and used to measure alveolar clearance rates during the course of the study. This method was used to describe a maximum functionally tolerated dose (MFTD). Pulmonary retention of toner and control materials (TiO2 and SiO2) was measured after 3, 9, 15, 21, and 24 months of exposure. The quantity of all three materials retained in the lungs and lung-associated lymph nodes increased with exposure duration and level. The final pulmonary burdens of toner at the three exposure levels were 0.22, 1.73, and 15.6 mg/lung, respectively. Alveolar clearance of both tracers was substantially impaired at the toner high-exposure level, and moderately slowed at the toner middle-exposure level. The excessive quantity of toner retained and the substantially retarded clearance in the toner high-exposure group are indicative of "lung overloading." Alveolar clearance of 85Sr-polystyrene particles was slightly slowed in the TiO2-exposed group and substantially impaired in the SiO2-exposed group. The alveolar clearance of the unexposed rats decreased about 30% during the study, a change ascribed to aging. For a general description of the toxicokinetics of the various dusts, a semiempirical kinetic model was developed, which could generally be useful for the extrapolation of lung retention of insoluble particles from a subchronic to a chronic inhalation study. Both the maximum tolerated dose (MTD) and the MFTD were exceeded at the toner high-exposure level during the study in rats.

  2. Metabolism of nanomaterials in vivo: blood circulation and organ clearance.

    PubMed

    Wang, Bing; He, Xiao; Zhang, Zhiyong; Zhao, Yuliang; Feng, Weiyue

    2013-03-19

    Before researchers apply nanomaterials (NMs) in biomedicine, they need to understand the blood circulation and clearance profile of these materials in vivo. These qualities determine the balance between nanomaterial-induced activity and unwanted toxicity. NMs have heterogeneous characteristics: they combine the bulk properties of solids with the mobility of molecules, and their highly active contact interfaces exhibit diverse functionalities. Any new and unexpected circulation features and clearance patterns are of great concern in toxicological studies and pharmaceutical screens. A number of studies have reported that NMs can enter the bloodstream directly during their application or indirectly via inhalation, ingestion, and dermal exposure. Due to the small size of NMs, the blood can then transport them throughout the circulation and to many organs where they can be stored. In this Account, we discuss the blood circulation and organ clearance patterns of NMs in the lung, liver, and kidney. The circulation of NMs in bloodstream is critical for delivery of inhalable NMs to extrapulmonary organs, the delivery of injectable NMs, the dynamics of tissue redistribution, and the overall targeting of drug carriers to specific cells and organs. The lung, liver, and kidney are the major distribution sites and target organs for NMs exposure, and the clearance patterns of NMs in these organs are critical for understanding the in vivo fate of NMs. Current studies suggest that multiple factors control the circulation and organ clearance of NMs. The size, shape, surface charge, surface functional groups, and aspect ratio of NMs as well as tissue microstructures strongly influence the circulation of NMs in bloodstream, their site-specific extravasation, and their clearance profiles within organs. Therefore structure design and surface modification can improve biocompatibility, regulate the in vivo metabolism, and reduce the toxicity of NMs. The biophysicochemical interactions

  3. [Leukemia stem cells and their targeted clearance].

    PubMed

    Liu, Bo; Shi, Ce; Zhou, Jin

    2014-08-01

    Leukemia stem cells(LSC) are the root causes of the leukemia, and are also the main reason for the leukemia relapse. Researchers hope that there are some methods to specifically mark the LSC and to clear them for promoting the advancements in the treatment of leukemia. This review discusses the biological characteristics of LSC and its microenvironment, the current internationally recognized main methods for specific marking of LSC, including marking LSC self-renewal, apoptosis signaling pathways, microenvironment, cell cycle-related signaling pathways and LSC-specific immune phenotype, so as to eliminate LSC and minimal residual disease through these marking ways. But, at present, there are no specific methods to remove leukaemia stem cells independently, possibly the combination of LSC immune phenotype with blocking the microenvironment signaling pathways can target at and remove LSC, thus improving the prognosis of leukemia.

  4. Plasma exogenous creatinine clearance in clinically healthy cats: comparison with urinary exogenous creatinine clearance, tentative reference intervals and indexation to bodyweight.

    PubMed

    Reynolds, B S; Massal, M R; Nguyen, P; Grégoire, L L; Périgaud, A E; Concordet, D; Biourge, V; Lefebvre, H P

    2014-10-01

    Glomerular filtration rate (GFR) is considered to be the best indicator of overall kidney function. The major objectives of this study were to compare plasma exogenous creatinine clearance (PECC) with a reference method, to establish reference intervals (RIs) for PECC and to assess the effects of indexation of GFR to bodyweight (BW) in cats. PECC was compared with urinary clearance of exogenous creatinine (UECC) in six clinically healthy domestic shorthair cats (experiment 1). Tentative RIs were determined according to current guidelines and the effects of indexation to BW and of covariables on GFR were assessed in 43 clinically healthy cats of various breeds (experiment 2). PECC was 15% higher than UECC (P <0.01), but the two estimates were strongly correlated (r(2)=0.97, P = 0.001). RIs for PECC were 6.4-21.3 mL/min or 1.2-4.9 mL/min/kg. The absolute (i.e. non-indexed) GFR value was not dependent on BW. Thus, indexation of GFR to BW in cats would not standardize the GFR value, but could introduce bias in clinical interpretation. Significant effects of breed, plasma protein concentration and plasma albumin concentration on GFR were demonstrated. Plasma concentrations of urea and creatinine, when assessed separately, were also weakly correlated with GFR in healthy cats. These combined findings contribute to a better understanding of renal function assessment in cats.

  5. 19 CFR 122.66 - Clearance or permission to depart denied.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Clearance of Aircraft and Permission To Depart § 122.66 Clearance or permission to depart denied. If advance electronic air cargo information is not received...

  6. 75 FR 53012 - Form Submitted to the Office of Management and Budget for Extension of Clearance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-30

    ... From the Federal Register Online via the Government Publishing Office SELECTIVE SERVICE SYSTEM... be obtained upon written request to the Selective Service System, Reports Clearance Officer, 1515... Selective Service System, Reports Clearance Officer, 1515 Wilson Boulevard, Arlington, Virginia...

  7. 77 FR 69658 - Agency Information Collection Activities; Proposed Collection; Comment Request: Generic Clearance...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-20

    ... approximately 4,350 respondents will be involved in exploratory, field test, pilot, cognitive, and focus group work conducted under this clearance over the requested 3-year clearance period. The average...

  8. 76 FR 49838 - Proposed Collection; Comment Request for Generic Clearance for the Collection of Qualitative...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-11

    ... Qualitative Feedback on Agency Service Delivery AGENCY: Internal Revenue Service (IRS), Treasury. ACTION..., the IRS is soliciting comments concerning Generic Clearance for the Collection of Qualitative Feedback... INFORMATION: Title: Generic Clearance for the Collection of Qualitative Feedback on Agency Service...

  9. 76 FR 45573 - Agency Information Collection Activities: Proposed Collection; Comment Request; Generic Clearance...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-29

    ... Clearance for the Collection of Qualitative Feedback on Agency Service Delivery AGENCY: Office of the... Request (Generic ICR): ``Generic Clearance for the Collection of Qualitative Feedback on Agency Service.... SUPPLEMENTARY INFORMATION: Title: Health Information Technology Research Center survey. Abstract:...

  10. 77 FR 19673 - Proposed Collection; Comment Request; Generic Clearance To Conduct Voluntary Customer/Partner...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-02

    ... HUMAN SERVICES National Institutes of Health Proposed Collection; Comment Request; Generic Clearance To... and Budget (OMB) for review and approval. Proposed Collection: Title: Generic Clearance to Conduct... strategy in ] accomplishing reinvention goals is the ability to periodically receive input and...

  11. Skin blood flow changes in anaesthetized humans: comparison between skin thermal clearance and finger pulse amplitude measurement.

    PubMed

    Saumet, J L; Leftheriotis, G; Dittmar, A; Delhomme, G; Degoute, C S

    1986-01-01

    The effect of general anaesthesia on skin blood flow in the left hand, measured by a new non-invasive probe using the thermal clearance method was examined. A mercury silastic gauge was placed around the third left finger and the plethysmographic wave amplitude was recorded to measure changes in finger pulse amplitude. Heart rate (HR), mean arterial blood pressure (MABP) and skin temperature were also recorded. General anaesthesia was induced by droperidol and phenoperidine injection and propanidid infusion in eight female patients. Skin thermal clearance, plethysmographic wave amplitude, HR, MABP and skin temperature were 0.40 +/- 0.02 w X m-1 degree C-1, 9 +/- 1 mm, 98 +/- 5 beats X min-1, 12.50 +/- 0.93 kPa and 33.3 +/- 3.4 degrees C respectively. The minimal value of MABP was 9.58 +/- 1.06 kPa, whereas skin thermal clearance, plethysmographic wave amplitude, HR and skin temperature increased to 0.45 +/- 0.02 w X m-1 degree C-1, 29 +/- 3 mm, 110 +/- 4 beats X min-1 and 34.4 +/- 0.4 degrees C. Changes in skin thermal clearance correlated well with plethysmographic wave amplitude. Statistically significant changes in these two parameters occurred before significant change in HR, MABP or skin temperature. The results show that the new non-invasive probe using the thermal clearance method appears to be a useful device for measuring cutaneous microcirculation in anaesthetized humans, and responds more quickly than change in skin temperature, which is a delayed effect of skin blood flow change. Our results also show that the intensity of cutaneous vasodilatation induced by general anaesthesia did not relate to the vascular tone before anaesthesia.

  12. EMD-based fault diagnosis for abnormal clearance between contacting components in a diesel engine

    NASA Astrophysics Data System (ADS)

    Li, Yujun; Tse, Peter W.; Yang, Xin; Yang, Jianguo

    2010-01-01

    The accuracy of fault diagnostic systems for diesel engine-type generators relies on a comparison of the currently extracted sensory features with those captured during normal operation or the so-called "baseline." However, the baseline is not easily obtained without the required expertise. Even worse, in an attempt to save costs, many of the diesel engine generators in manufacturing plants are second hand or have been purchased from unknown suppliers, meaning that the baseline is unknown. In this paper, a novel vibration-based fault diagnostic method is developed to identify the vital components of a diesel engine that have abnormal clearance. The advantage of this method is that it does not require the comparison of current operating parameters to those collected as the baseline. First, the nominal baseline is obtained via theoretical modeling rather than being actually captured from the sensory signals in a healthy condition. The abnormal clearance is then determined by inspecting the timing of impacts created by the components that had abnormal clearance during operation. To detect the timing of these impacts from vibration signals accurately, soft-re-sampling and empirical mode decomposition (EMD) techniques are employed. These techniques have integrated with our proposed ranged angle (RA) analysis to form a new ranged angle-empirical mode decomposition method (RA-EMD). To verify the effectiveness of the RA-EMD in detecting the impacts and their times of occurrence, their induced vibrations are collected from a series of generators under normal and faulty engine conditions. The results show that this method is capable of extracting the impacts induced by vibrations and is able to determine their times of occurrence accurately even when the impacts have been overwhelmed by other unrelated vibration signals. With the help of the RA-EMD, clearance-related faults, such as incorrect open and closed valve events, worn piston rings and liners, etc., become detectable

  13. 49 CFR 236.22 - Semaphore signal arm; clearance to other objects.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Semaphore signal arm; clearance to other objects...; clearance to other objects. At least one-half inch clearance shall be provided between semaphore signal arm, and any object that may interfere with its operation....

  14. 48 CFR 1845.506-70 - Responsibilities of the plant clearance officer.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... plant clearance officer. 1845.506-70 Section 1845.506-70 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CONTRACT MANAGEMENT GOVERNMENT PROPERTY Support Government Property Administration 1845.506-70 Responsibilities of the plant clearance officer. When plant clearance is not...

  15. 76 FR 24920 - Agency Information Collection Activities: Proposed Collection; Comment Request; Generic Clearance...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-03

    ...; Generic Clearance for the Collection of Qualitative Feedback on Agency Service Delivery AGENCY: National... (Generic ICR): ``Generic Clearance for the Collection of Qualitative Feedback on Agency Service Delivery...: Generic Clearance for the Collection of Qualitative Feedback on Agency Service Delivery. Abstract:...

  16. 20 CFR 653.501 - Requirements for accepting and processing clearance orders.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... clearance any job order seeking workers to perform agricultural or food processing work before reviewing it... order seeking workers to perform agricultural or food processing work into intrastate clearance unless... perform agricultural or food processing work with interstate clearance unless: (1) The job order meets...

  17. 77 FR 28625 - Comment Request for Information Collection for the Agricultural and Food Processing Clearance...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-15

    ... Food Processing Clearance Order, ETA Form 790, Extension With Revisions, and the Agricultural and Food... employers must use the Agricultural and Food Processing Clearance Order, ETA Form 790, to list the job... Agricultural and Food Processing Clearance Memorandum, ETA Form 795, is used by SWAs to extend job...

  18. Noninvasive real-time measurement of nasal mucociliary clearance in mice by pinhole gamma scintigraphy.

    PubMed

    Hua, Xiaoyang; Zeman, Kirby L; Zhou, Bingqing; Hua, Qingquan; Senior, Brent A; Tilley, Stephen L; Bennett, William D

    2010-01-01

    Mucociliary clearance (MCC) is the key defense mechanism in the upper airways, as the removal of debris-laden mucus in the sinuses completely depends on MCC. So far, how the nasal MCC is regulated remains unknown. Recently, mice deficient in genes encoding the components of MCC apparatus have been generated, which will allow investigators to conduct more in-depth nasal MCC studies. However, the methodology necessary to comprehensively evaluate the nasal MCC in this species is not well established. We therefore developed a novel method to measure nasal MCC in live mice using pinhole gamma camera. Insoluble radiolabeled particles were delivered into the noses of lightly anesthetized mice. The nasal clearance of these particles was measured continuously in a real-time manner. The effect of three different anesthetics-avertin, pentobarbital, and isoflurane-on nasal MCC was also determined. In mice anesthetized by 1.1% isoflurane, radiolabeled particles were immediately moved into the oropharynx, which was significantly accelerated by the treatment of hypertonic but not isotonic saline. According to the clearance rate, the mouse nasal MCC presented two distinct phases: a rapid phase and a slow phase. In addition, we found that isoflurane had a very small inhibitory effect on nasal MCC vs. both avertin and pentobarbital. This was further supported by its dose response. Collectively, we have developed a noninvasive method to monitor the real-time nasal MCC in live mice under physiological conditions. It provides more comprehensive evaluation on nasal MCC rather than assessing a single component of the MCC apparatus in isolation.

  19. Comparison of Functional Variants in IFNL4 and IFNL3 for Association with Hepatitis C Virus Clearance

    PubMed Central

    O’Brien, Thomas R.; Pfeiffer, Ruth M.; Paquin, Ashley; Lang Kuhs, Krystle A.; Chen, Sabrina; Bonkovsky, Herbert L.; Edlin, Brian R.; Howell, Charles D.; Kirk, Gregory D.; Kuniholm, Mark H.; Morgan, Timothy R.; Strickler, Howard D.; Thomas, David L.; Prokunina-Olsson, Ludmila

    2015-01-01

    Background & Aims Genetic polymorphisms within the interferon lambda (IFN-λ) region are strongly associated with hepatitis C virus (HCV) clearance; the IFNL4-ΔG/TT (rs368234815) polymorphism, which controls generation of the IFN-λ4 protein, is more strongly associated with HCV clearance than rs12979860 (the ‘IL28B variant’). An IFNL3 3′ untranslated region polymorphism (rs4803217) has been proposed as a causal variant that may affect HCV clearance by altering IFNL3 mRNA stability. Methods We compared IFNL4-ΔG/TT and rs4803217 for association with response to pegylated-IFN-α/ribavirin in the VIRAHEP-C and HALT-C trials, and spontaneous HCV clearance in the ALIVE, UHS and WIHS studies. Genotyping was performed with TaqMan assays. We compared differences in mean reduction in HCV RNA levels by genotype and haplotype. For HCV clearance, we calculated p-values comparing c-statistics for IFNL4-ΔG/TT and rs4803217 genotypes by a bootstrap approach. Results Among European Americans, linkage disequilibrium between IFNL4-ΔG/TT and rs4803217 was strong (r2=0.89–0.99) and there were no significant differences between the variants. In African American (AA) individuals enrolled in VIRAHEP-C, HCV RNA at treatment day 28 was more strongly associated with IFNL4-ΔG/TT than rs4803217 (p=0.003); the IFNL4-ΔG:rs4803217-G haplotype, which includes the putatively favorable IFNL3 allele, was actually associated with the poorest day 28 response (p=0.03, comparison to IFNL4-ΔG:rs4803217-T haplotype). Among AA participants, associations were stronger for IFNL4-ΔG/TT than rs4803217 for undetectable HCV RNA at week 24 in Virahep C (p=0.03) and week 20 in HALT-C (p=0.03), as well as for spontaneous HCV clearance (p=0.048). Conclusion IFNL4-ΔG/TT is the primary IFN-λ region polymorphism for impaired HCV clearance. PMID:26186989

  20. Production and clearance of plasma triacylglycerols in ponies fed diets containing either medium-chain triacylglycerols or soya bean oil.

    PubMed

    Hallebeek, J M; Beynen, A C

    2003-06-01

    The hypothesis was tested that feeding ponies a diet containing medium-chain triacylglcyerols (MCT) instead of soya bean oil causes an increase in the production of plasma triacylglycerols, which, under steady-state conditions, is associated with an increased clearance of triacylglycerols. Six ponies were fed rations containing either MCT or an isoenergetic amount of soya bean oil according to a cross-over design. The concentration of MCT in the total dietary dry matter was about 13%. When the ponies were fed the diets for 3 weeks, plasma triacylglycerol concentrations were 0.42 +/- 0.09 and 0.17 +/- 0.03 mmol/l (mean +/- SE, n = 6; p < 0.05) for the MCT and soya bean-oil treatment, respectively. Plasma triacylglycerol production was assessed using the Triton method and clearance with the use of Intralipid(R) infusion. Plasma triacylglycerol production was 2.91 +/- 0.88 and 0.50 +/- 0.14 micromol/l.min (means +/- SE, n = 4; p < 0.05) for the diets containing MCT and soya bean oil, respectively. It is suggested that the calculated rates of triacylglycerol production are underestimated, the deviation being greatest when the ponies were fed the ration of soya bean oil. Triacylglycerol clearance rates were calculated on the basis of group mean values for both the fractional clearance rate and the baseline levels of plasma triacylglycerols; the values were 4.28 and 3.52 micromol/l.min for MCT and soya bean oil feeding, respectively. The mean, absolute clearance rates as based on those found in individual ponies did not show an increase when the diet with MCT was fed. Nevertheless, it is concluded that the data obtained support our hypothesis.

  1. Interest of ICG blood clearance monitoring for reproducible 810-nm diode laser coagulation of blood vessels

    NASA Astrophysics Data System (ADS)

    Desmettre, Thomas; Soulie-Begu, Sylvie; Devoisselle, Jean-Marie; Mordon, Serge R.

    1999-02-01

    Purpose: To evaluate a method of control of diode laser fluence leading to a reproducible ICG-enhanced selective photocoagulation of blood vessels. This method would use the chromophore clearance, i.e. ICG blood concentration decay to adapt the laser fluence. Materials and Methods: A skin flap window was used on hamsters. After a 15 mg/kg ICG solution injection, photocoagulation of vessels were performed. Results: Selective photocoagulation of blood vessels was obtained only during the first 10 minutes. The fluence required to obtain a selective photocoagulation of vessels (F) was modelized using a one compartment phamacokinetic equation: F equals Of(1-e-t/(tau )). The best fit was obtained for a time constant (tau) equals 4.8 min and Of equals 300 J/cm2 (correlation coefficient r2 equals 0.996). During the first 10 minutes, the fluence required for selective photocoagulation of vessels was increased by a factor 4.5. Conclusion: Fluence required for a selective photocoagulation of vessels was correlated to ICG blood concentration decay. The time constant was equivalent to ICG half-life time in human blood. These results demonstrate that diode laser ICG-enhanced photocoagulation can be controlled by monitoring the ICG blood clearance.

  2. Correlation of elimination fraction area under the curve with total body clearance.

    PubMed

    Grabowski, Tomasz; Raczyńska-Pawelec, Anna; Starościak, Marcin; Jaroszewski, Jerzy Jan

    2016-02-01

    This study attempted to determine the area under the curve ([Formula: see text]), which corresponds to the sum of all elimination processes correlated with the total clearance value. The study attempted to determine the [Formula: see text] based on the coordinates known from classic non-compartmental pharmacokinetics for a single administration of the drug. 318 pharmacokinetics profiles were used for the analysis, obtained from 220 healthy subjects over ten studies. Pharmacokinetic calculations were performed with the use of Phoenix™ WinNonlin(®) 6.3. The leave-one-out (LOO) method was used for model cross-validation. Squared cross-validated correlation coefficient (Q (2)) parameter and the difference between Q (2) and R (2) were calculated as a measure of the internal performance and model predictive ability. A high correlation between the clearance value and [Formula: see text] was demonstrated (R (2) > 0.65). However, only in the case of four studies was it possible to validate the linear model using the leave-one-out validation procedure (R (2) > 0.86). The present study proposed a method of graphical and mathematical determination of the area under the curve for the drug elimination process after a single dose of the drug. Furthermore, the concept of calculating the statistical moments and mean elimination time (MET) only for elimination processes based on [Formula: see text] was presented. The result of this work is also a new method of determining the half-life of elimination phase based on the MET value.

  3. A Hybrid Jigsaw Approach to Teaching Renal Clearance Concepts

    PubMed Central

    Pollack, Gary M.

    2009-01-01

    Objectives To evaluate the effectiveness of using a jigsaw cooperative learning approach to teach basic concepts of renal clearance to pharmacy students. Design Students collected information on the mechanisms of renal clearance for a particular drug and proposed a methodology for circumventing a urine drug screen. Attitudinal surveys, an online quiz, and course examinations were used to assess student learning. Assessment The majority of students felt apprehensive toward a group assignment prior to the exercise, and afterwards still preferred individual work over group work. Post-exercise quiz and final examination scores showed students successfully learned the material. Conclusions Students were successful in learning from each other and there was no difference in examination performance compared to years when the technique was not used. In addition, the relative negative experiences of previous group work decreased the subjective attitudes related to the current learning experience. PMID:19564992

  4. Microwave Sensor for Blade Tip Clearance and Structural Health Measurements

    NASA Technical Reports Server (NTRS)

    Woike, Mark R.; Bencic, Timothy J.

    2008-01-01

    The use of microwave based sensors for the health monitoring of rotating machinery is being explored at the NASA Glenn Research Center. The microwave sensor works on the principle of sending a continuous signal towards a rotating component and measuring the reflected signal. The phase shift of the reflected signal is proportional to the distance between the sensor and the component that is being measured. This type of sensor is beneficial in that it has the ability to operate at extremely high temperatures and is unaffected by contaminants that may be present in the rotating machinery. It is intended to use these probes in the hot sections of turbine engines for closed loop turbine clearance control and structural health measurements. Background on the sensors, an overview of their calibration and preliminary results from using them to make blade tip clearance and health measurements on a large axial vane fan will be presented.

  5. Lung-clearance mechanisms following inhalation of acid sulfates

    SciTech Connect

    Wolff, R.K.; Muggenburg, B.A.; Silbaugh, S.A.; Carpenter, R.L.; Rowatt, J.D.; Hill, J.O.

    1982-08-01

    These studies have indicated that acute exposures (1-6 hrs) to sulfuric acid at levels of 0.5 to 1.0 mg/m/sup 3/ can produce impairments in mucous clearance. The impairments can last for up to a week following a 1 hr exposure. These effects and studies by others suggest that high sulfate levels in polluted conditions may be one factor in observed increases of hospital visits for respiratory problems. Long term exposures to elevated levels of sulfates resulting in decreases of clearance could also be an initiating factor in producing chronic obstructive pulmonary disease (COPD). These studies have also shown that it is the larger size fraction (0.6 to 1.0 ..mu..m) of sulfuric acid mist in the urban aerosol which is predominantly responsible for at least the acute effects.

  6. Apoptotic cell clearance: basic biology and therapeutic potential.

    PubMed

    Poon, Ivan K H; Lucas, Christopher D; Rossi, Adriano G; Ravichandran, Kodi S

    2014-03-01

    The prompt removal of apoptotic cells by phagocytes is important for maintaining tissue homeostasis. The molecular and cellular events that underpin apoptotic cell recognition and uptake, and the subsequent biological responses, are increasingly better defined. The detection and disposal of apoptotic cells generally promote an anti-inflammatory response at the tissue level, as well as immunological tolerance. Consequently, defects in apoptotic cell clearance have been linked with various inflammatory diseases and autoimmunity. Conversely, under certain conditions, such as the killing of tumour cells by specific cell-death inducers, the recognition of apoptotic tumour cells can promote an immunogenic response and antitumour immunity. Here, we review the current understanding of the complex process of apoptotic cell clearance in physiology and pathology, and discuss how this knowledge could be harnessed for new therapeutic strategies.

  7. [Amylase-creatinine clearance ratios in burned patients (author's transl)].

    PubMed

    Minaire, Y; Marichy, J; Forichon, J; Motin, J

    1978-09-01

    The amylase/creatinine clearance ratio (ACCR) has been examined every 3 days, in 34 burned patients during the 20 days following the accident. This ratio was often abnormal since it was found increased at least on one occasion, in 75% of these patients, to be compared with 23 and 13% for amylase in serum and urine respectively. In another group of 9 burned patients, the ACCR was monitored for time-period between 10 to 52 days. It was observed that a high frequency in increased ACCR was associated with a fatal outcome. Finally simultaneous measurements of ACCR and of the beta2 microglobulin/creatinine clearance ratio (MCCR) showed that increased ACCR were statistically associated with increased MCCR suggesting a decreased renal tubular reabsorption of low molecular weight proteins in these burned patients.

  8. Gas film lubrication equations for very small clearances

    SciTech Connect

    Sobehart, J.R.; Reyna, L.G.

    1994-05-01

    In the hard disk magnetic recording technology, the slider carrying the magnetic elements is supported above the magnetic disk by a self-acting air bearing, which produces the load support. A lubricating film must support a required load with suitably small frictional energy losses and without introducing undesirable instabilities. Under submicron clearance conditions, gas film flow can not be described with continuum models since the molecular mean free path is not negligible compared with the clearance. Accurate results for the load-carrying capacity of gas films for arbitrary Knudsen number are very important since they strongly influence the design of the flying head slider and, consequently, the performance of the magnetic disk storage unit. Here we generalize the previous lubrication equations for arbitrary Knudsen number, accommodation coefficient and a small inclination of the slider relative to the magnetic disk surface.

  9. Schwann cell autophagy, myelinophagy, initiates myelin clearance from injured nerves.

    PubMed

    Gomez-Sanchez, Jose A; Carty, Lucy; Iruarrizaga-Lejarreta, Marta; Palomo-Irigoyen, Marta; Varela-Rey, Marta; Griffith, Megan; Hantke, Janina; Macias-Camara, Nuria; Azkargorta, Mikel; Aurrekoetxea, Igor; De Juan, Virginia Gutiérrez; Jefferies, Harold B J; Aspichueta, Patricia; Elortza, Félix; Aransay, Ana M; Martínez-Chantar, María L; Baas, Frank; Mato, José M; Mirsky, Rhona; Woodhoo, Ashwin; Jessen, Kristján R

    2015-07-01

    Although Schwann cell myelin breakdown is the universal outcome of a remarkably wide range of conditions that cause disease or injury to peripheral nerves, the cellular and molecular mechanisms that make Schwann cell-mediated myelin digestion possible have not been established. We report that Schwann cells degrade myelin after injury by a novel form of selective autophagy, myelinophagy. Autophagy was up-regulated by myelinating Schwann cells after nerve injury, myelin debris was present in autophagosomes, and pharmacological and genetic inhibition of autophagy impaired myelin clearance. Myelinophagy was positively regulated by the Schwann cell JNK/c-Jun pathway, a central regulator of the Schwann cell reprogramming induced by nerve injury. We also present evidence that myelinophagy is defective in the injured central nervous system. These results reveal an important role for inductive autophagy during Wallerian degeneration, and point to potential mechanistic targets for accelerating myelin clearance and improving demyelinating disease.

  10. [Amylase-creatinine clearance ratios in burned patients (author's transl)].

    PubMed

    Minaire, Y; Marichy, J; Forichon, J; Motin, J

    1978-09-01

    The amylase/creatinine clearance ratio (ACCR) has been examined every 3 days, in 34 burned patients during the 20 days following the accident. This ratio was often abnormal since it was found increased at least on one occasion, in 75% of these patients, to be compared with 23 and 13% for amylase in serum and urine respectively. In another group of 9 burned patients, the ACCR was monitored for time-period between 10 to 52 days. It was observed that a high frequency in increased ACCR was associated with a fatal outcome. Finally simultaneous measurements of ACCR and of the beta2 microglobulin/creatinine clearance ratio (MCCR) showed that increased ACCR were statistically associated with increased MCCR suggesting a decreased renal tubular reabsorption of low molecular weight proteins in these burned patients. PMID:360162

  11. Schwann cell autophagy, myelinophagy, initiates myelin clearance from injured nerves

    PubMed Central

    Gomez-Sanchez, Jose A.; Carty, Lucy; Iruarrizaga-Lejarreta, Marta; Palomo-Irigoyen, Marta; Varela-Rey, Marta; Griffith, Megan; Hantke, Janina; Macias-Camara, Nuria; Azkargorta, Mikel; Aurrekoetxea, Igor; De Juan, Virginia Gutiérrez; Jefferies, Harold B.J.; Aspichueta, Patricia; Elortza, Félix; Aransay, Ana M.; Martínez-Chantar, María L.; Baas, Frank; Mato, José M.; Mirsky, Rhona

    2015-01-01

    Although Schwann cell myelin breakdown is the universal outcome of a remarkably wide range of conditions that cause disease or injury to peripheral nerves, the cellular and molecular mechanisms that make Schwann cell–mediated myelin digestion possible have not been established. We report that Schwann cells degrade myelin after injury by a novel form of selective autophagy, myelinophagy. Autophagy was up-regulated by myelinating Schwann cells after nerve injury, myelin debris was present in autophagosomes, and pharmacological and genetic inhibition of autophagy impaired myelin clearance. Myelinophagy was positively regulated by the Schwann cell JNK/c-Jun pathway, a central regulator of the Schwann cell reprogramming induced by nerve injury. We also present evidence that myelinophagy is defective in the injured central nervous system. These results reveal an important role for inductive autophagy during Wallerian degeneration, and point to potential mechanistic targets for accelerating myelin clearance and improving demyelinating disease. PMID:26150392

  12. Surface code—biophysical signals for apoptotic cell clearance

    NASA Astrophysics Data System (ADS)

    Biermann, Mona; Maueröder, Christian; Brauner, Jan M.; Chaurio, Ricardo; Janko, Christina; Herrmann, Martin; Muñoz, Luis E.

    2013-12-01

    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.

  13. Respiratory Protection Program medical clearance for respirator use

    NASA Technical Reports Server (NTRS)

    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.

  14. Dysregulation of Nutrient Sensing and CLEARance in Presenilin Deficiency

    PubMed Central

    Reddy, Kavya; Cusack, Corey L.; Nnah, Israel C.; Khayati, Khoosheh; Saqcena, Chaitali; Huynh, Tuong B.; Noggle, Scott A.; Ballabio, Andrea; Dobrowolski, Radek

    2016-01-01

    Summary 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

  15. Turbine Engine Clearance Control Systems: Current Practices and Future Directions

    NASA Technical Reports Server (NTRS)

    Lattime, Scott B.; Steinetz, Bruce M.

    2002-01-01

    Improved blade tip sealing in the high pressure compressor (HPC) and high pressure turbine (HPT) can provide dramatic reductions in specific fuel consumption (SFC), time-on-wing, compressor stall margin, and engine efficiency as well as increased payload and mission range capabilities. Maintenance costs to overhaul large commercial gas turbine engines can easily exceed $1M. Engine removal from service is primarily due to spent exhaust gas temperature (EGT) margin caused mainly by the deterioration of HPT components. Increased blade tip clearance is a major factor in hot section component degradation. As engine designs continue to push the performance envelope with fewer parts and the market drives manufacturers to increase service life, the need for advanced sealing continues to grow. A review of aero gas turbine engine HPT performance degradation and the mechanisms that promote these losses are discussed. Benefits to the HPT due to improved clearance management are identified. Past and present sealing technologies are presented along with specifications for next generation engine clearance control systems.

  16. Smoking produced mucus and clearance of particulates in the lung

    SciTech Connect

    Sterling, T.D.; Poland, T.M.

    1992-12-31

    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.

  17. Rate-Based Model Predictive Control of Turbofan Engine Clearance

    NASA Technical Reports Server (NTRS)

    DeCastro, Jonathan A.

    2006-01-01

    An innovative model predictive control strategy is developed for control of nonlinear aircraft propulsion systems and sub-systems. At the heart of the controller is a rate-based linear parameter-varying model that propagates the state derivatives across the prediction horizon, extending prediction fidelity to transient regimes where conventional models begin to lose validity. The new control law is applied to a demanding active clearance control application, where the objectives are to tightly regulate blade tip clearances and also anticipate and avoid detrimental blade-shroud rub occurrences by optimally maintaining a predefined minimum clearance. Simulation results verify that the rate-based controller is capable of satisfying the objectives during realistic flight scenarios where both a conventional Jacobian-based model predictive control law and an unconstrained linear-quadratic optimal controller are incapable of doing so. The controller is evaluated using a variety of different actuators, illustrating the efficacy and versatility of the control approach. It is concluded that the new strategy has promise for this and other nonlinear aerospace applications that place high importance on the attainment of control objectives during transient regimes.

  18. Applying Organ Clearance Concepts in a Clinical Setting

    PubMed Central

    2008-01-01

    Objective To teach doctor of pharmacy (PharmD) students how to apply organ clearance concepts in a clinical setting in order to optimize dose management, select the right drug product, and promote better patient-centered care practices. Design A student-focused 5-hour topic entitled "Organ Clearance Concepts: Modeling and Clinical Applications" was developed and delivered to second-year PharmD students. Active-learning techniques, such as reading assignments and thought-provoking questions, and collaborative learning techniques, such as small groups, were used. Student learning was assessed using application cards and a minute paper. Assessment Overall student responses to topic presentation were overwhelmingly positive. The teaching strategies here discussed allowed students to play an active role in their own learning process and provided the necessary connection to keep them motivated, as mentioned in the application cards and minute paper assessments. Students scored an average of 88% on the examination given at the end of the course. Conclusion By incorporating active-learning and collaborative-learning techniques in presenting material on organ clearance concept, students gained a more thorough knowledge of dose management and drug-drug interactions than if the concepts had been presented using a traditional lecture format. This knowledge will help students in solving critical patient situations in a real-world context. PMID:19214275

  19. RAB24 facilitates clearance of autophagic compartments during basal conditions

    PubMed Central

    Ylä-Anttila, Päivi; Mikkonen, Elisa; Happonen, Kaisa E; Holland, Petter; Ueno, Takashi; Simonsen, Anne; Eskelinen, Eeva-Liisa

    2015-01-01

    RAB24 belongs to a family of small GTPases and has been implicated to function in autophagy. Here we confirm the intracellular localization of RAB24 to autophagic vacuoles with immuno electron microscopy and cell fractionation, and show that prenylation and guanine nucleotide binding are necessary for the targeting of RAB24 to autophagic compartments. Further, we show that RAB24 plays a role in the maturation and/or clearance of autophagic compartments under nutrient-rich conditions, but not during short amino acid starvation. Quantitative electron microscopy shows an increase in the numbers of late autophagic compartments in cells silenced for RAB24, and mRFP-GFP-LC3 probe and autophagy flux experiments indicate that this is due to a hindrance in their clearance. Formation of autophagosomes is shown to be unaffected by RAB24-silencing with siRNA. A defect in aggregate clearance in the absence of RAB24 is also shown in cells forming polyglutamine aggregates. This study places RAB24 function in the termination of the autophagic process under nutrient-rich conditions. PMID:26325487

  20. Automatic Detection of Clearance in Mechanical Systems: Experimental Validation

    NASA Astrophysics Data System (ADS)

    Stein, Jeffrey L.; Wang, Churn-Hway

    1996-07-01

    The performance of servosystems with gears (e.g. machine tool drive systems) depends on the clearance or backlash between the gear teeth. Too little and the gears cannot accommodate lubrication and manufacturing errors. Too much and the system accuracy and stability degrade. Therefore, to ensure that a machine system with gears is operating within specifications, the backlash magnitude should be checked frequently. A technique to estimate the backlash automatically is required. The objective of this paper is to evaluate experimentally a clearance detection technique, previously published by the authors, to detect backlash in a servosystem with gears. The technique estimates the backlash by computing the speed variations induced into the primary gear speed by the gear tooth impacts caused by exciting the system sinusoidally. It is shown that a low-cost conventional tachometer is sufficient to measure the induced speed variations. The estimates are shown to represent accurately the actual backlash for ranges 100% of the recommended backlash setting. In addition, by exciting the system with a sinusoid having a DC offset, it is shown that, in a simple one step automatic procedure, the backlash can be averaged over all the gear tooth combinations or computed for individual gear tooth pairs. The results, along with the previously developed theory, indicate that this clearance detection can be inexpensively applied to many machine systems.

  1. Active Piezoelectric Structures for Tip Clearance Management Assessed

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Managing blade tip clearance in turbomachinery stages is critical to developing advanced subsonic propulsion systems. Active casing structures with embedded piezoelectric actuators appear to be a promising solution. They can control static and dynamic tip clearance, compensate for uneven deflections, and accomplish electromechanical coupling at the material level. In addition, they have a compact design. To assess the feasibility of this concept and assist the development of these novel structures, the NASA Lewis Research Center developed in-house computational capabilities for composite structures with piezoelectric actuators and sensors, and subsequently used them to simulate candidate active casing structures. The simulations indicated the potential of active casings to modify the blade tip clearance enough to improve stage efficiency. They also provided valuable design information, such as preliminary actuator configurations (number and location) and the corresponding voltage patterns required to compensate for uneven casing deformations. An active ovalization of a casing with four discrete piezoceramic actuators attached on the outer surface is shown. The center figure shows the predicted radial displacements along the hoop direction that are induced when electrostatic voltage is applied at the piezoceramic actuators. This work, which has demonstrated the capabilities of in-house computational models to analyze and design active casing structures, is expected to contribute toward the development of advanced subsonic engines.

  2. Nonpharmacologic airway clearance techniques in hospitalized patients: a systematic review.

    PubMed

    Andrews, Jeff; Sathe, Nila A; Krishnaswami, Shanthi; McPheeters, Melissa L

    2013-12-01

    Nonpharmacologic airway clearance techniques are used to reduce the sequelae of obstructive secretions. We systematically reviewed comparative studies of nonpharmacologic interventions that health professionals can employ to achieve mucus clearance in hospitalized or postoperative patients without cystic fibrosis, over the age of 12 months. We searched MEDLINE and other databases from 1990 to 2012 to identify relevant literature. Two reviewers independently assessed each study against predetermined inclusion/exclusion criteria. Two reviewers also independently extracted data regarding subject and intervention characteristics and outcomes, and assigned overall quality ratings. The 32 studies meeting the review criteria included 24 randomized controlled trials, 7 crossover randomized controlled trials, and one prospective cohort study. Studies were typically small and together included a total of 2,453 subjects (mean 76/study). Studies generally examined chest physical therapy/physiotherapy modalities in postoperative or critically ill subjects or those with COPD. Interventions, comparators, and populations varied considerably across studies, hampering our ability to draw firm conclusions. Interventions, including conventional chest physical therapy/physiotherapy, intrapulmonary percussive ventilation, and positive expiratory pressure, typically provided small benefits in pulmonary function, gas exchange, oxygenation, and need for/duration of ventilation, among other outcomes, but differences between groups were generally small and not significant. Harms of the techniques were not consistently reported, though airway clearance techniques were generally considered safe in studies that did comment on adverse effects. Further research with clearly characterized populations and interventions is needed to understand the potential benefits and harms of these techniques. PMID:24222708

  3. Dynamic Studies of Lung Fluid Clearance with Phase Contrast Imaging

    SciTech Connect

    Kitchen, Marcus J.; Williams, Ivan; Irvine, Sarah C.; Morgan, Michael J.; Paganin, David M.; Lewis, Rob A.; Pavlov, Konstantin; Hooper, Stuart B.; Wallace, Megan J.; Siu, Karen K. W.; Yagi, Naoto; Uesugi, Kentaro

    2007-01-19

    Clearance of liquid from the airways at birth is a poorly understood process, partly due to the difficulties of observing and measuring the distribution of air within the lung. Imaging dynamic processes within the lung in vivo with high contrast and spatial resolution is therefore a major challenge. However, phase contrast X-ray imaging is able to exploit inhaled air as a contrast agent, rendering the lungs of small animals visible due to the large changes in the refractive index at air/tissue interfaces. In concert with the high spatial resolution afforded by X-ray imaging systems (<100 {mu}m), propagation-based phase contrast imaging is ideal for studying lung development. To this end we have utilized intense, monochromatic synchrotron radiation, together with a fast readout CCD camera, to study fluid clearance from the lungs of rabbit pups at birth. Local rates of fluid clearance have been measured from the dynamic sequences using a single image phase retrieval algorithm.

  4. Differentially regulated gene expression associated with hepatitis C virus clearance

    PubMed Central

    Grimes, Carolyn Z.; Hwang, Lu-Yu; Wei, Peng; Shah, Dimpy P.; Volcik, Kelly A.

    2013-01-01

    Human chronic hepatitis C virus (HCV) infections pose a significant public health threat, necessitating the development of novel treatments and vaccines. HCV infections range from spontaneous resolution to end-stage liver disease. Approximately 10–30 % of HCV infections undergo spontaneous resolution independent of treatment by yet-to-be-defined mechanisms. These individuals test positive for anti-HCV antibodies in the absence of detectable viral serum RNA. To identify genes associated with HCV clearance, this study compared gene expression profiles between current drug users chronically infected with HCV and drug users who cleared their HCV infection. This analysis identified 91 differentially regulated (up- or downregulated by twofold or more) genes potentially associated with HCV clearance. The majority of genes identified were associated with immune function, with the remaining genes categorized either as cancer related or ‘other’. Identification of factors and pathways that may influence virus clearance will be essential to the development of novel treatment strategies. PMID:23152368

  5. Regulation of mucociliary clearance in health and disease.

    PubMed

    Houtmeyers, E; Gosselink, R; Gayan-Ramirez, G; Decramer, M

    1999-05-01

    Airway secretions are cleared by mucociliary clearance (MCC), in addition to other mechanisms such as cough, peristalsis, two-phase gas-liquid flow and alveolar clearance. MCC comprises the cephalad movement of mucus caused by the cilia lining the conducting airways until it can be swallowed or expectorated. MCC is a very complex process in which many variables are involved, all of which may modify the final outcome. The structure, number, movement and co-ordination of the cilia present in the airways as well as the amount, composition and rheological properties of the periciliary and mucus layers are determinants of MCC. Physiological factors such as age, sex, posture, sleep and exercise are reported to influence MCC due to a change in the cilia, the mucus or the periciliary layer, or a combination of these. Environmental pollution is suspected to have a depressant effect on MCC dependent on different factors such as pollutant concentration and the duration of exposure. Most studies focus on sulphur dioxide, sulphuric acid, nitrogen dioxide and ozone. Tobacco smoke and hairspray have been noted to have a negative influence on MCC. Some diseases are known to affect MCC, mostly negatively. The underlying mechanism differs from one illness to another. Immotile cilia syndrome, asthma, bronchiectasis, chronic bronchitis, cystic fibrosis and some acute respiratory tract infections are among the most frequently reported. The present paper reviews normal mucociliary clearance and the effects of diseases on this process.

  6. Abnormal norepinephrine clearance and adrenergic receptor sensitivity in idiopathic orthostatic intolerance

    NASA Technical Reports Server (NTRS)

    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.

  7. Effect of adjuvant imiquimod 5% cream on sustained clearance of anogenital warts following laser treatment.

    PubMed Central

    Hoyme, U B; Hagedorn, M; Schindler, A E; Schneede, P; Hopfenmüller, W; Schorn, K; Eul, A

    2002-01-01

    OBJECTIVES: Imiquimod is an immune response modifier that has demonstrated a good efficacy and relatively low recurrence rates in comparison to other genital wart treatment modalities. The primary objective of this open-label study was to evaluate the effect on sustained clearance of treated lesions and the safety of patient-applied topical imiquimod after laser therapy of external anogenital warts. METHODS: After laser treatment of visible external anogenital warts the ablated region(s) were treated with imiquimod 5% cream three times/week over 12 weeks beginning when the wound healing process was completed, followed by a six-month treatment-free observation period for the assessment of sustained clearance of treated lesions. RESULTS: A total of 211 male and female patients was enrolled in the study. After 12 weeks of treatment, 65.4% of all patients showed sustained clearance. During the treatment period, 15 patients (7.1% of 211 patients) presented with recurrent warts in the treated areas, and 58 (27.5%) patients were excluded for other reasons. During the six-month follow-up period, ten additional patients (7.3% of 138 patients) developed wart recurrences. The application of imiquimod 5% cream was well tolerated. The number of patients with adverse events related to study medication declined from the first month of treatment until the end of the third month. Most frequently, mild to moderate itching, burning, pain and erythema were reported. CONCLUSIONS: After laser therapy and sufficient wound healing, administration of imiquimod 5% cream three times/week appears to be safe and to reduce the incidence of wart recurrences. PMID:12530484

  8. Mapping soil magnetic properties in Bosnia and Herzegovina for landmine clearance operations

    NASA Astrophysics Data System (ADS)

    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.

  9. Clearance of man made mineral fibres from the lungs of sheep

    PubMed Central

    Dufresne, A.; Perrault, G.; Yamato, H.; Masse, S.; Begin, R.

    1999-01-01

    OBJECTIVES: To compare the clearance rate, the related pathology, and the chemical and morphological changes of three man made mineral fibres (MMMFs) in the sheep model of pneumoconiosis. METHODS: Fibrous particles were extracted from lung parenchyma and analysed by transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). RESULTS: The concentration of MMMF11, MMMF21, refractory ceramic fibre (RCF-1), and crocidolite asbestos fibres decreased with time according to a slow and a fast kinetic component. There was a statistical difference in the four regression lines as a function of time and the type of fibres (p < 0.001). The diameter of MMMFs decreased during the course of the time, whereas the crocidolite fibres did not seem to show any change. There was a statistical difference in the four regression lines as a function of time (p = 0.037) and type of fibres (p < 0.001). Ferruginous bodies were counted in the 40 sheep for which the latency period was 2 years. No typical ferruginous bodies were found in the groups exposed to MMMFs. The geometric mean concentration of asbestos bodies in the group exposed to crocidolite was 2421 bodies/g lung tissue (95% CI 385 to 15260). CONCLUSIONS: The number of initially retained fibres decreased with time according to a slow and a fast kinetic component. MMMF11 and MMMF21 have similar clearance, faster than RCF-1 and crocidolite. The geometric mean diameter and length of MMMF decreased with time, but crocidolite did not. After 2 years in the sheep tracheal lobe, ferruginous bodies were not found in all three MMMF groups but were substantial in the crocidolite group. Clearance is thought to proceed through dissolution and macrophage translocation.   PMID:10658548

  10. A Matter of Millimeters: Defining the Processes for Critical Clearances on Curiosity

    NASA Technical Reports Server (NTRS)

    Florow, Brandon

    2013-01-01

    The Mars Science Laboratory (MSL) mission presents an immense packaging problem in that it takes a rover the size of a car with a sky crane landing system and packs it tightly into a spacecraft. This creates many areas of close and critical clearances. Critical Clearances are defined as hardware-to-hardware or hardware-to-envelope clearances which fall below a pre-established location dependent threshold and pose a risk of hardware to hardware contact during events such as launch, entry, landing, and operations. Close Clearances, on the other hand, are defined as any clearance value that is chosen to be tracked but is larger than the critical clearance threshold for its region. Close clearances may be tracked for various reasons including uncertainty in design, large expected dynamic motion, etc.

  11. Surgery for gallbladder cancer in the US: a need for greater lymph node clearance

    PubMed Central

    Nissen, Nicholas N.

    2015-01-01

    Background Gallbladder cancer (GBC) is a rare malignancy with a dismal prognosis. Often identified incidentally after laparoscopic cholecystectomy for presumably benign biliary disease, reoperation with partial hepatic resection and periportal lymph node dissection (LND) is frequently performed. The impact of lymph node (LN) clearance for GBC remains unclear. Methods The Surveillance, Epidemiology, and End Results (SEER) database was queried for patients diagnosed with GBC between 1988 and 2009. Survival was calculated using Kaplan-Meier method and compared using log-rank test. Multivariate analysis was performed to identify predictors of survival. Results A total of 11,815 patients diagnosed with GBC were identified. Cancer-directed surgery was performed in 8,436 (71.3%) patients. Optimal LN clearance (defined as ≥4 LNs) is associated with young age, advanced T-stage, no radiation therapy, and radical surgery (all <0.001). Greater LND improves survival for all stages (P<0.001). After adjusting for confounding factors, multivariable analysis of patients with node-negative disease demonstrated that early stage, greater LND, and radical surgery were strong independent predictors of survival. Conclusions Extensive lymphadenectomy correlates with longer survival even in node negative patients. Extensive LND should be performed in patients with GBC as many patients in the USA are undertreated. PMID:26487937

  12. Integrating the Clearance in NPP Residual Material Management

    SciTech Connect

    Garcia-Bermejo, R.; Lamela, B.

    2008-01-15

    Previous Experiences in decommissioning projects are being used to optimize the residual material management in NPP, metallic scrap usually. The approach is based in the availability of a materials Clearance MARSSIM-based methodology developed and licensed in Spain. A typical project includes the integration of segregation, decontamination, clearance, quality control and quality assurance activities. The design is based in the clearance methodology features translating them into standard operational procedures. In terms of ecological taxes and final disposal costs, significant amounts of money could be saved with this type of approaches. The last clearance project managed a total amount of 405 tons scrap metal and a similar amount of other residual materials occupying a volume of 1500 m{sup 3}. After less than a year of field works 251 tons were finally recycled in a non-licensed smelting facility. The balance was disposed as LILW. In the planning phase the estimated cost savings were 4.5 Meuro. However, today a VLLW option is available in European countries so, the estimated cost savings are reduced to 1.2 Meuro. In conclusion: the application of materials clearance in NPP decommissioning lessons learnt to the NPP residual material management is an interesting management option. This practice is currently going on in Spanish NPP and, in a preliminary view, is consistent with the new MARSAME Draft. An interesting parameter is the cost of 1 m3 of recyclable scrap. The above estimates are very project specific because in the segregation process other residual materials were involved. If the effect of this other materials is removed the estimated Unit Cost were in this project around 1700 euro/m{sup 3}, this figure is clearly below the above VLLW disposal cost of 2600 euro. In a future project it appears feasible to descend to 839 euro/m{sup 3} and if it became routine values and is used in big Decommissioning projects, around 600 euro/m{sup 3} or below possibly could

  13. Elevated amylase creatinine clearance ratio and normal serum amylase levels in chronic relapsing pancreatitis after partial pancreatectomy.

    PubMed

    Cattau, E L; Garcia-Torres, F

    1980-12-01

    A 29-year-old woman admitted for alcohol detoxification five years after a 90% distal pancreatectomy for chronic pancreatitis had abdominal pain similar to that associated with preoperative pancreatitis. Although her clinical course was consistent with recurrent pancreatitis, the serum amylase level remained normal, but the amylase creatinine clearance ratio became elevated and then returned to normal, paralleling her clinical course. The ACCR may be a useful laboratory method in diagnosing chronic recurrent pancreatitis in patients with decreased functional pancreatic tissue.

  14. Use of uptake intrinsic clearance from attached rat hepatocytes to predict hepatic clearance for poorly permeable compounds.

    PubMed

    Huang, Liyue; Chen, April; Roberts, John; Janosky, Brett; Be, Xuhai; Berry, Loren; Lin, Min-Hwa Jasmine

    2012-09-01

    We previously reported that the accuracy of clearance (CL) prediction could be differentiated by permeability. CL was drastically under-predicted by in vitro metabolic intrinsic clearance (CL(int)) for compounds with low permeability (<5 × 10(-6) cm/s). We determined apparent uptake CL(int) by measuring initial disappearance from medium using attached rat hepatocytes and metabolic CL(int) by measuring parent depletion in suspended rat hepatocytes (cells and medium). Uptake and metabolic CL(int) were comparable for highly permeable metabolic marker compounds. In contrast, uptake CL(int) was 3- to 40-fold higher than metabolic CL(int) for rosuvastatin, bosentan, and 15 proprietary compounds, which had low permeability, suggesting that uptake could be a rate-determining step in hepatic elimination for these poorly permeable compounds. The prediction of hepatic CL was improved significantly when using uptake CL(int) for the compounds with low permeability. The average fold error was 2.2 and 6, as opposed to >11 and >47 by metabolic CL(int), with and without applying a scaling factor of 4, respectively. Uptake CL(int) from attached hepatocytes can be used as an alternative approach to predict hepatic clearance and to understand the significance of hepatic uptake in elimination in an early drug discovery setting. PMID:22439758

  15. Use of uptake intrinsic clearance from attached rat hepatocytes to predict hepatic clearance for poorly permeable compounds.

    PubMed

    Huang, Liyue; Chen, April; Roberts, John; Janosky, Brett; Be, Xuhai; Berry, Loren; Lin, Min-Hwa Jasmine

    2012-09-01

    We previously reported that the accuracy of clearance (CL) prediction could be differentiated by permeability. CL was drastically under-predicted by in vitro metabolic intrinsic clearance (CL(int)) for compounds with low permeability (<5 × 10(-6) cm/s). We determined apparent uptake CL(int) by measuring initial disappearance from medium using attached rat hepatocytes and metabolic CL(int) by measuring parent depletion in suspended rat hepatocytes (cells and medium). Uptake and metabolic CL(int) were comparable for highly permeable metabolic marker compounds. In contrast, uptake CL(int) was 3- to 40-fold higher than metabolic CL(int) for rosuvastatin, bosentan, and 15 proprietary compounds, which had low permeability, suggesting that uptake could be a rate-determining step in hepatic elimination for these poorly permeable compounds. The prediction of hepatic CL was improved significantly when using uptake CL(int) for the compounds with low permeability. The average fold error was 2.2 and 6, as opposed to >11 and >47 by metabolic CL(int), with and without applying a scaling factor of 4, respectively. Uptake CL(int) from attached hepatocytes can be used as an alternative approach to predict hepatic clearance and to understand the significance of hepatic uptake in elimination in an early drug discovery setting.

  16. Tip clearance flow interaction with circumferential groove casing treatment in a transonic axial compressor

    NASA Astrophysics Data System (ADS)

    Ross, Mark Hamilton

    Experimental and computational studies were conducted to study the role of the tip leakage flow in axial compressor stall and the relationship between the tip clearance flow flow field and surge margin extension from circumferential groove casing treatment. The CFD results were used to identify the existence of an interface between the approach ow and the tip-leakage flow. The experiments used a surface streaking visualization method to identify the time-averaged location of this interface as a line of zero axial shear stress at the casing. The axial position of this line, denoted xzs, moved upstream with decreasing ow coefficient in both the experiments and computations. The line was consistently located at the rotor leading edge plane at the stalling flow coefficient, regardless of in flow boundary condition. These results were successfully modeled using a control volume approach that balanced the reverse axial momentum ux of the tip-leakage flow with the momentum flux of the approach fluid. Non-uniform tip clearance measurements demonstrated that movement of the interface upstream of the rotor leading edge plane leads to the generation of short length scale rotating disturbances. Therefore, stall was interpreted as a critical point in the momentum flux balance of the approach ow and the reverse axial momentum flux of the tip-leakage flow. Experimental measurements of surge margin extension from seven CGCT configurations with a fixed groove geometry demonstrated that the contribution of individual grooves in a multi-groove casing to surge margin extension is an (a) additive and (b) linear function of the smooth wall tip clearance axial momentum ux at the location of a each groove. Extending the axial momentum model to include the in uence of a CGCT showed that circumferential grooves reduce the tip leakage flow axial momentum through radial transport. The equivalent force due to a circumferential groove was demonstrated to be related to the smooth wall tip

  17. Pregnancy does not alter the metabolic clearance of 1,25-dihydroxyvitamin D in rats

    SciTech Connect

    Paulson, S.K.; Ford, K.K.; Langman, C.B. )

    1990-01-01

    Increased circulating levels of 1,25-dihydroxyvitamin D (1,25(OH)2D) during pregnancy could be due to an increase in production or decrease in the metabolic clearance rate of 1,25(OH)2D. To answer this question an isotope dilution method was used to determine the clearance rate of 1,25(OH)2D in pregnant and aged-matched nonpregnant female rats. A bolus of 0.146 muCi 1,25(OH)2(3H)D3 was given to 60 pregnant and 60 aged-matched nonpregnant rats and the disappearance of the isotope was followed in these animals over the next 48 h. In 12 pregnant rats vs. 14 nonpregnant controls not injected with tracer, plasma calcium (9.6 +/- 0.41 vs. 10.7 +/- 0.17 mg/ml) and 25(OH)D (17.1 +/- 1.15 vs. 25.4 +/- 1.58 ng/ml) levels were significantly lower (P less than 0.01 and P less than 0.001), whereas plasma 1,25(OH)2D levels (110 +/- 16.1 pg/ml vs. 77 +/- 6.0 pg/ml) were significantly higher (P less than 0.05). Clearance rates of 1,25(OH)2D of 25.8 +/- 1.31 microliters/min in pregnant rats and 20.2 20.2 +/- 1.38 microliters/min in nonpregnant aged-matched rats were not significantly different. Similarly, the apparent volume of distribution of 1,25(OH)2D in the pregnant rats (15 +/- 1.0 ml) was not significantly different from that in the nonpregnant control animals (18 +/- 2.1 ml). Production rates of.1,25(OH)2D were elevated in the pregnant rats (2.83 pg/min) compared with the nonpregnant controls (1.55 pg/min). In conclusion, the elevated maternal plasma 1,25(OH)2D level during pregnancy is a result of increased production and is not due to a decreased clearance.

  18. Role of neutrophilic elastase in ethanol induced injury to the gastric mucosa

    SciTech Connect

    Kvietys, P.R.; Carter, P.R. )

    1990-02-26

    Intragastric administration of ethanol (at concentrations likely to be encountered by the mucosa during acute intoxication) produces gastritis. Recent studies have implicated neutrophils in the gastric mucosal injury induced by luminal ethanol. The objective of the present study was to assess whether neutrophilic elastase contributes to the ethanol-induced gastric mucosal injury. Sprague-Dawley rats were instrumented for perfusion of the gastric lumen with saline or ethanol. Mucosal injury was quantitated by continuously measuring the blood-to-lumen clearance of {sup 51}Cr-EDTA. The experimental protocol consisted of a 40 minute control period (saline perfusion) followed by three successive 40 minute experimental periods (ethanol perfusion). During the three experimental periods the concentration of ethanol was progressively increased to 10, 20, and 30%. The experiments were performed in untreated animals and in animals pretreated with either Eglin c (an inhibitor of elastase and cathepsin G activity) or L 658 (a specific inhibitor of elastase activity). The effects of ethanol on EDTA clearance (x control) in untreated (n = 9) and L658 treated (n = 5) animals are shown in the Table below. Pretreatment with L 658 significantly attenuated the ethanol-induced increases in EDTA clearance. Pretreatment with Eglin c (n = 6) also provided some protection against ethanol-induced injury, but not to the extent as that provided by L658. The results of the authors studies suggest that neutrophilic elastase contributes to a gastric mucosal injury induced by luminal perfusion of the stomach with physiologically relevant concentrations of ethanol.

  19. [Evaluation of a modified exogenous creatinine clearance as a suitable renal function test for the small animal practice].

    PubMed

    Höchel, Joachim; Finnah, Anke; Velde, Karsten; Hartmann, Helmut

    2004-01-01

    A suitable method in the routine veterinary practice for the quantitative determination of the glomerular filtration rate (GFR) in dogs and cats has not been available until to date. Therefore, we modified the known plasma clearance model (=P-CL). The resulting P-CLterminal was assessed concerning its diagnostic value. P-CL of exogenous creatinine (P-CLcrea) and of inulin were determined in dogs (n=12, Beagle, 6 months of age) and cats (n=11, Domestic Short Hair, 14 months of age). The marker substances were administered as a bolus injection. In fasted dogs, P-CLcrea was 84.3 +/- 14.85 ml/min/m2 after a creatinine dose of 2.4 g/m2. An electrolyte infusion during the clearance determination did not alter the resulting values (p>0.05). In fasted cats, P-CLcrea was 54.7 +/- 5.8 ml/min/m2 (creatinine dose 2.0 g/m2). The inulin clearance, determined at the same time, was 104.5 +/- 19.81 ml/min/m2. Feeding the cats just before and during the test increased P-CL of both markers significantly (p<0.05). In order to adapt the clearance method for diagnostic assessment of GFR in the small animal practice, we aimed at minimizing the number of required blood samples (3 instead of 7 or more) and introduced the modified exogenous creatinine clearance (P-CLterminal). These values determined were 108.4 +/- 20.81 ml/min/m2 in fasted dogs and 66.3 +/- 11.81 ml/min/m2 in fasted cats. An electrolyte infusion (dogs) and feeding (cats) had the same effect on P-CLterminal values as described above for P-CL. In conclusion,the modified exogenous creatinine clearance is a suitable renal function test for the early diagnosis of renal disease in dogs and cats presented in small animal practices. PMID:15495934

  20. Persistence, clearance and reinfection regarding six high risk human papillomavirus types in Colombian women: a follow-up study

    PubMed Central

    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 clearance of each type of HPV. The role of a group of independent variables concerning the time taken until clearance was evaluated using a Cox proportional-hazards regression model or parametric (log-logistic) methods when necessary. Regarding viral load, the Wilcoxon rank-sum test was used for measuring the difference of medians for viral load for each type, according to the state of infection (cleared or persistent). The Kruskal-Wallis test was used for evaluating the change in the women’s colposcopy findings at the start of follow-up and at the end of it (whether due to clearance or the end of the follow-up period). Results It was found that HPV-18 and HPV-31 types had the lowest probability of becoming cleared (1.76 and 2.75 per 100 patients/month rate, respectively). Women from Colombian cities other than Bogotá had a greater probability of being cleared if they had HPV-16 (HR 2.58: 1.51–4.4 95% CI) or HPV-58 (1.79 time ratio: 1.33-2.39 95% CI) infection. Regarding viral load, HPV-45-infected women having 1 × 106 to 9.99 × 109 viral copies had better clearance compared to those having greater viral loads (1.61 time ratio: 1.01-2.57 95% CI). Lower HPV-31 viral load values were associated with this type’s persistence and changes in colposcopy findings for HPV-16 gave the worst prognosis in women having low absolute load values. Conclusions HPV infection clearance in this study was related to factors such as infection type, viral load and the characteristics of the