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Sample records for 51cr-edta clearance method

  1. Mannitol clearance for the determination of glomerular filtration rate-a validation against clearance of (51) Cr-EDTA.

    PubMed

    Kiss, Katalin; Molnár, Miklós; Söndergaard, Sören; Molnár, Gyula; Ricksten, Sven-Erik

    2016-06-03

    We studied the agreement between plasma clearance of mannitol and the reference method, plasma clearance of (51) Cr-EDTA in outpatients with normal to moderately impaired renal function. Forty-one patients with a serum creatinine <200 μmol l(-1) entered the study. (51) Cr-EDTA clearance was measured with the standard bolus injection technique and glomerular filtration rate (GFR) was calculated by the single-sample method described by Jacobsson. Mannitol, 0·25 g kg(-1) body weight (150 mg ml(-1) ), was infused for 4-14 min and blood samples taken at 1-, 2-, 3- and 4-h (n = 24) or 2-, 3-, 3·5- and 4-h after infusion (n = 17). Mannitol in serum was measured by an enzymatic method. Plasma clearance for mannitol and its apparent volume of distribution (Vd) were calculated according to Brøchner-Mortensen. Mean plasma clearance (±SD) for (51) Cr-EDTA was 59·7 ± 18·8 ml min(-1) . The mean plasma clearance for mannitol ranged between 57·0 ± 20·1 and 61·1 ± 16·7 ml min(-1) and Vd was 21·3 ± 6·2% per kg b.w. The between-method bias ranged between -0·23 and 2·73 ml min(-1) , the percentage error between 26·7 and 39·5% and the limits of agreement between -14·3/17·2 and -25·3/19·9 ml min(-1) . The best agreement was seen when three- or four-sample measurements of plasma mannitol were obtained and when sampling started 60 min after injection. Furthermore, accuracy of plasma clearance determinations was 88-96% (P30) and 41-63% (P10) and was highest when three- or four-sample measurements of plasma mannitol were obtained, including the first hour after the bolus dose. We conclude that there is a good agreement between plasma clearances of mannitol and (51) Cr-EDTA for the assessment of GFR.

  2. Exaggerated natriuretic response to isotonic volume expansion in hypertensive renal transplant recipients: evaluation of proximal and distal tubular reabsorption by simultaneous determination of renal plasma clearance of lithium and 51Cr-EDTA.

    PubMed

    Nielsen, A H; Knudsen, F; Danielsen, H; Pedersen, E B; Fjeldborg, P; Madsen, M; Brøchner-Mortensen, J; Kornerup, H J

    1987-02-01

    In fourteen hypertensive and fourteen normotensive renal transplant recipients, and in a group of thirteen healthy controls, changes in natriuresis, glomerular filtration rate (GFR), and tubular reabsorption of sodium were determined in relation to intravenous infusion of 2 mmol isotonic sodium chloride per kg body weight. An exaggerated natriuresis was demonstrated in the hypertensive renal transplant recipients. This new finding indicates that the augmented natriuresis following plasma volume expansion, which is a characteristic finding in subjects with arterial hypertension, is not mediated by the renal nerves. Investigation of the tubular reabsorption rates of sodium by simultaneous determination of the renal clearance of 51Cr-EDTA and lithium showed that in the hypertensives the changes in tubular handling of sodium were different from those registered in the normotensive subjects. The increased sodium excretion in the hypertensive renal transplant recipients was caused by an increased output of sodium from the proximal tubules which was not fully compensated for by an increased distal reabsorption. Whether this increased delivery of sodium to the distal segments was caused by changes in GFR or in the proximal tubular reabsorption of sodium could not be clarified in the present study and warrants further investigations.

  3. /sup 51/Cr-EDTA: a marker of early intestinal rejection in the rat

    SciTech Connect

    Grant, D.; Lamont, D.; Zhong, R.; Garcia, B.; Wang, P.; Stiller, C.; Duff, J.

    1989-05-01

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

  4. (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.

  5. 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.

  6. 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).

  7. 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.

  8. Renal distribution volumes of indocyanine green, ( 51 Cr)EDTA, and 24 Na in man during acute renal failure after shock. Implications for the pathogenesis of anuria.

    PubMed

    Reubi, F C; Vorburger, C; Tuckman, J

    1973-02-01

    The mechanism responsible for the anuria in acute renal failure after shock is still controversial. Suppressed glomerular filtration and/or tubular back-diffusion of the filtrate are major possible causes. In the present investigation, seven patients with acute anuria, three of these seven again in the polyuric phase, six patients with moderate renal impairment, four patients with chronic renal failure, and eight subjects with normal renal function were studied by a multiple indicator-dilution method in which the total renal blood flow and renal distribution volumes of indocyanine green, [(51)Cr]EDTA, and (24)Na were determined. In normal subjects the average values for one kidney were 582 ml/min, 42 ml, 92 ml, and 139 ml, respectively. The measurements in the patients with moderate renal impairment were similar to those in the normal subjects, but were decreased in chronic renal failure. In acute anuria, the average values were 269 ml/min, 40 ml, 101 ml, and 114 ml and the kidney volume, estimated radiographically, was increased by 40%. When expressed as milliliters per milliliters kidney, the average distribution volume of (24)Na was decreased from 0.64 to 0.38. This decrease is consistent with the hypothesis that suppressed filtration is largely responsible for the anuria and that back-diffusion is, at most, a contributory factor. The apparent contradiction between the relatively well-preserved total blood flow and the suppressed filtration may be due to a combination of afferent vasoconstriction and efferent vasodilatation. This view is supported by the observation that low filtration fractions were found in clearance measurements performed during the polyuric phase.

  9. Renal Distribution Volumes of Indocyanine Green, [51Cr]EDTA, and 24Na in Man during Acute Renal Failure after Shock. IMPLICATIONS FOR THE PATHOGENESIS OF ANURIA

    PubMed Central

    Reubi, F. C.; Vorburger, C.; Tuckman, J.

    1973-01-01

    The mechanism responsible for the anuria in acute renal failure after shock is still controversial. Suppressed glomerular filtration and/or tubular back-diffusion of the filtrate are major possible causes. In the present investigation, seven patients with acute anuria, three of these seven again in the polyuric phase, six patients with moderate renal impairment, four patients with chronic renal failure, and eight subjects with normal renal function were studied by a multiple indicator-dilution method in which the total renal blood flow and renal distribution volumes of indocyanine green, [51Cr]EDTA, and 24Na were determined. In normal subjects the average values for one kidney were 582 ml/min, 42 ml, 92 ml, and 139 ml, respectively. The measurements in the patients with moderate renal impairment were similar to those in the normal subjects, but were decreased in chronic renal failure. In acute anuria, the average values were 269 ml/min, 40 ml, 101 ml, and 114 ml and the kidney volume, estimated radiographically, was increased by 40%. When expressed as milliliters per milliliters kidney, the average distribution volume of 24Na was decreased from 0.64 to 0.38. This decrease is consistent with the hypothesis that suppressed filtration is largely responsible for the anuria and that back-diffusion is, at most, a contributory factor. The apparent contradiction between the relatively well-preserved total blood flow and the suppressed filtration may be due to a combination of afferent vasoconstriction and efferent vasodilatation. This view is supported by the observation that low filtration fractions were found in clearance measurements performed during the polyuric phase. PMID:4630601

  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. [Study of age and sex dependance in renal clearances with radioisotopes (author's transl)].

    PubMed

    Schernthaner, G; Erd, W; Ludwig, H; Sinzinger, H; Höfer, R

    1976-03-01

    In 85 patients between 15 and 95 years of age (40 male patients and 45 females) without any signs of renal disease (concentration of serum creatinine below 1,4 mg/100ml, normal diastolic blood pressure and normal urine analysis) a highly significant negative correlation was found between glomerular filtration rate (GFR, determined by 51Cr-EDTA - slope-clearance) and renal plasma flow (RPF, determined by 131J-oJHS-iodinehippuricacid-totalclearance) on one side and age on the other. Beginning with a basic value of 160 ml in males and 144 ml in females for GFR, the average decrease per year was 1,2 ml/1,0 ml respectively. The basis value of RPF was 854 ml for males and 673 ml for females, the decrease per year was 5,4 ml in men and 2,9 ml in women. The importance of physiological diminution of clearance values in elderly patients and its consequences for therapy are discussed. The more exact and methodically simpler 51Cr-EDTA-slope-clearance without urine collection should be used instead of the somewhat inaccurate determination of endogenous creatinine clearance especially in older patients.

  12. Contrast media and glomerular filtration: dose dependence of clearance for three agents

    SciTech Connect

    Baeck, S.E.K.; Krutzen, E.; Nilsson-Ehle, P.

    1988-09-01

    Determination of plasma clearance of contrast agents has been advocated as a means to assess glomerular filtration rate. To evaluate the feasibility of different agents for this purpose, we have compared, in healthy volunteers, the dose dependence of plasma clearance for three contrast media (iohexol, a nonionic agent, and iothalamate and metrizoate, which are ionic substances), with special emphasis on the lower dose range (2-20 mL corresponding to 0.9-12.9 g, depending on dose and agent). Iohexol and iothalamate were cleared at constant rates, irrespective of given dose, whereas metrizoate clearance increased significantly at lower doses. In general, the clearances or iothalamate and metrizoate were, respectively, moderately and markedly higher than that of iohexol. The clearance of different doses of metrizoate (2 mL versus a radiographic dose of 40 mL or more) was also compared with the clearance of (/sup 51/Cr)EDTA in two groups of patients with reduced renal function. When compared with (/sup 51/Cr)EDTA in patients with renal dysfunction, metrizoate was cleared significantly faster after a 2-mL dose, whereas clearances were identical when the metrizoate dose was 40 mL or more. These findings indicate that tubular secretion plays an active role in the elimination of metrizoate. The pharmacokinetic properties of iohexol, in combination with its low toxicity, make it a suitable agent for determination of glomerular filtration rate in clinical practice.

  13. A novel relay method for determining low-clearance values.

    PubMed

    Di, Li; Trapa, Patrick; Obach, R Scott; Atkinson, Karen; Bi, Yi-An; Wolford, Angela C; Tan, Beijing; McDonald, Thomas S; Lai, Yurong; Tremaine, Larry M

    2012-09-01

    A novel relay method has been developed using cryopreserved human hepatocytes to measure intrinsic clearance of low-clearance compounds. The relay method involved transferring the supernatant from hepatocyte incubations to freshly thawed hepatocytes at the end of the 4-h incubation to prolong the exposure time to active enzymes in hepatocytes. An accumulative incubation time of 20 h or longer in hepatoctyes can be achieved using the method. The relay method was validated using seven commercial drugs (diazepam, disopyramide, theophylline, timolol, tolbutamide, S-warfarin, and zolmitriptan) that were metabolized by various cytochrome P450s with low human in vivo intrinsic clearance at approximately 2 to 15 ml · min⁻¹ · kg⁻¹. The results showed that the relay method produced excellent predictions of human in vivo clearance. The difference between in vitro and in vivo intrinsic clearance was within 2-fold for most compounds, which is similar to the standard prediction accuracy for moderate to high clearance compounds using hepatocytes. The relay method is a straightforward, relatively low cost, and easy-to-use new tool to address the challenges of low clearance in drug discovery and development.

  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. Comparison of methods for estimating glomerular filtration rate in head and neck cancer patients treated with cisplatin.

    PubMed

    Lindberg, Lotte; Brødbæk, Kasper; Hägerström, Erik G; Bentzen, Jens; Kristensen, Bent; Zerahn, Bo

    2017-03-20

    Cisplatin is a chemotherapeutic agent widely used in the treatment of various solid tumors. Cisplatin induces nephrotoxicity and may lead to long-term reduction of kidney function. Consequently, determination of glomerular filtration rate (GFR) is used to monitor potential kidney damage. This study aimed to compare two commonly used algorithms for estimating GFR (eGFR) from plasma creatinine (PCr) with (51)Cr-EDTA clearance (CrCl) as a reference method. This was a retrospective single center study of 94 head and neck cancer patients treated with cisplatin. CrCl was performed once before, during, and after treatment, and PCr was measured concurrently. eGFR was assessed from PCr applying the Cockcroft-Gault (CG) and the Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) equations. Agreement was assessed applying the statistical methods of Bland and Altman. A predefined limit of clinically acceptable variation between CrCl and eGFR of 14% was applied. Comparison of CrCl and eGFRCKD revealed a positive slope of the linear regression line, suggesting proportional bias (p < 0.001). No systematic bias was found for eGFRCG. Pre-treatment, 42 (46%), 53 (56%) and 48 (53%) observations were within the clinically acceptable limit of variation for standardized eGFRCKD, BSA corrected eGFRCKD, and eGFRCG, respectively. The observed body weight changes were significant. In conclusion, estimated GFRCKD cannot sufficiently replace CrCl in the assessment of GFR during treatment with cisplatin due to systematic bias. Consequently, if CrCl is unavailable, then the CG equation is the better choice provided proper attention is paid to the large variation between methods.

  17. Estimation of glomerular filtration rate from low-dose injection of iohexol and a single blood sample

    SciTech Connect

    Thomsen, H.S.; Hvid-Jacobsen, K. )

    1991-04-01

    Clearance of a small dose of iohexol (7 g I) was compared with the glomerular filtration rate (GFR) marker {sup 51}Cr EDTA in 11 healthy volunteers. The two tracers were injected simultaneously. The plasma concentration of iohexol was measured with x-ray fluorescence technique. Glomerular filtration rate was determined using blood samples drawn three and four hours after injection. An excellent correlation (0.92 less than r less than 0.97) between iohexol clearance and {sup 51}Cr EDTA clearance was found. Glomerular filtration rate can be reliably determined with a low dose of iohexol and a single blood sample obtained three hours after the injection in persons with normal serum creatinine. This new method is a good alternative to the methods using radiopharmaceuticals; it causes no radioactive burden to the patients, increases patient comfort, reduces costs, and requires no special license.

  18. Stress analysis method for a clearance fit bolt under bearing loads

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    In the present, simple analysis method for bolt hole clearance stresses in mechanically fastened joints, an inverse formulation is used with a finite element analysis. Conditions along the bolt hole contact arc are specified by displacement constraint equations. The method was applied to a single fastener clearance-fit joint with typical clearance values, for the cases of a rigid, frictionless bolt and a quasi-isotropic graphite/epoxy laminate. Results indicate that the contact arc, as well as the peak stresses around the hole (and their locations), were strongly influenced by the clearance. After a minor initial nonlinearity, peak stresses varied linearly with applied load. Clearance levels are found to have only a minor influence on overall joint stiffness.

  19. 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.

  20. 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.

  1. Regional variation in use of exogenous and endogenous glomerular filtration rate (GFR) markers in Sweden

    PubMed Central

    Vilhelmsdotter Allander, Susanne; Marké, Lars-Åke; Wihlen, Björn; Svensson, Maria; Elinder, Carl-Gustaf

    2012-01-01

    Background Markers of renal function (glomerular filtration rate (GFR)) are frequently used in the Swedish health care. GFR is usually estimated based on plasma creatinine concentration, but plasma cystatin C concentration, creatinine clearance, iohexol clearance, and 51Cr-EDTA clearance are also used. These markers are all part of the daily patient care, but there is little specific information on the clinical use of these markers. The aim of this study was to compare the use of these various GFR markers in different parts of Sweden and potential changes over time. Methods Retrospective study using questionnaires to collect information for the years 2006–2009 divided per county on the specific use of GFR markers with type of test reports. Results Plasma/serum creatinine concentration (96%) is by far the dominating GFR marker in Sweden, while cystatin C concentration (3.5%), creatinine clearance (0.1%), iohexol clearance (0.1%), and 51Cr-EDTA clearance (0.1%) are less frequently used. The use of GFR markers, including creatinine, continues to increase on a national level with the exception of creatinine clearance and 51Cr-EDTA clearance. There were considerable variations between different counties in the use of GFR markers and the type of test reports that the laboratories provided. Conclusions The inter-county variations of GFR markers used in Sweden are large and indicate that savings associated with optimized test utilization in this regard could be substantial. Regional habits and traditions are likely to influence the variations in GFR marker use. PMID:22401136

  2. 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.

  3. 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.

  4. 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.

  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. Estimation of Glomerular Filtration Rate in Elderly Chronic Kidney Disease Patients: Comparison of Three Novel Sophisticated Equations and Simple Cystatin C Equation.

    PubMed

    Bevc, Sebastjan; Hojs, Nina; Hojs, Radovan; Ekart, Robert; Gorenjak, Maksimiljan; Puklavec, Ludvik

    2017-03-10

    Estimating glomerular filtration rate (GFR) in elderly patients is a problem, since they are poorly represented in studies developing GFR equations. Serum cystatin C is a better indicator of GFR than serum creatinine in elderly patients. Therefore the aim of our study was to compare frequently used serum cystatin C based GFR equations with a gold standard ((51) CrEDTA clearance) in elderly chronic kidney disease (CKD) patients. 106 adult Caucasian patients, older than 65 years (58 women, 48 men; mean age 72.5 years), were included. In each patient (51) CrEDTA clearance, serum creatinine (IDMS traceable method) and serum cystatin C (immunonephelometric method) were determined. GFR was estimated using the Simple cystatin C, CKD-EPI cystatin C, CKD-EPI creatinine-cystatin C and BIS2 equation. Mean serum creatinine of our patients was 141.4 ± 41.5 μmol/L, mean serum cystatin C 1.79 ± 0.6 mg/L, mean (51) CrEDTA clearance was 52.2 ± 15.9 mL/min per 1.73 m(2) . Statistically significant correlations between (51) CrEDTA clearance and all formulas were found (P < 0.0001). In the receiver operating characteristic (ROC) curve analysis (cut-off for GFR 45 mL/min per 1.73 m(2) ) no significant differences in diagnostic accuracy between all the before mentioned equations were found. Bland-Altman analysis for the same cut-off showed that CKD-EPI creatinine-cystatin C and BIS2 equation underestimated and CKD-EPI cystatin C and Simple cystatin C equation overestimated measured GFR. All equations lacked precision. Analysis of ability to correctly predict patient's GFR below or above 45 mL/min per 1.73 m(2) showed similar ability for all equations (P = 0.24-0.89). All equations are equally accurate for estimating GFR in elderly Caucasian CKD patients. For daily practice Simple cystatin C equation is most practical.

  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. 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

    A simple direct stress analysis method is proposed for a laminate with a clearance-fit fastener subjected to combined bearing and bypass loads in tension or compression, including bearing and bypass loads on bolt-hole contact and local stresses. The approach uses a linear-elastic finite element analysis with an inverse formulation; conditions along the bolt-hole interface are specified by constraint equations that limit nodal displacements to a circular arc corresponding to the bolt diameter. The application of the method to the analysis of the effects of bearing-bypass loading on bolt-hole contact angles and local stresses, with the plate material properties representing a quasi-isotropic T300/5208 graphite/epoxy laminate, is discussed.

  9. Simulation of bronchial mucociliary clearance of insoluble particles by computational fluid and particle dynamics methods.

    PubMed

    Farkas, Arpád; Szöke, István

    2013-08-01

    For a correct assessment of health consequences of inhaled aerosols as a function of dose, whether for environmental, occupational or therapeutic agents, knowledge of their deposition distribution in the respiratory tract and subsequent clearance is important. The objective of this study is to model particle clearance at bronchial airway bifurcation level and to analyze the combined effect of deposition and clearance. For this purpose, a numerical model has been implemented. Air and mucus flow fields were computed in a model bronchial airway bifurcation. Inhaled particles with 1 and 10 µm aerodynamic diameters were tracked to determine deposition and clearance patterns. Simulation results revealed the existence of a slow clearance zone around the peak of the airway bifurcation causing delayed clearance of the particles depositing or entering here. Particles clearing up from the deeper airways and crossing the studied bifurcation do not accumulate in this zone, because of their tendency to avoid it. The average residence time of these particles was around 20 min independently of particle size (whether it is 1 or 10 µm). However, as a result of the superposition of deposition and clearance mechanisms, the final spatial distribution of particles deposited primarily in the target bifurcation is size dependent, because deposition is size specific. Although deposition density of particles deposited in the slow clearance area is one-two orders of magnitude higher than the average deposition density, these values are reduced by clearance by the factors of 4-7, depending on the particle size and the surface area of the selected slow clearance zone. In conclusion, although particle deposition is inhomogeneous, clearance can significantly decrease the degree of spatial non-uniformity of the particles. Therefore, for a correct assessment of doses at local levels, it is important to consider both deposition and clearance. Although future research may overwrite some of

  10. New IVIVE method for the prediction of total human clearance and relative elimination pathway contributions from in vitro hepatocyte and microsome data.

    PubMed

    Riede, Julia; Poller, Birk; Umehara, Ken-ichi; Huwyler, Jörg; Camenisch, Gian

    2016-04-30

    Total human clearance is a key determinant for the pharmacokinetic behavior of drug candidates. Our group recently introduced the Extended Clearance Model (ECM) as an accurate in vitro-in vivo extrapolation (IVIVE) method for the prediction of hepatic clearance. Yet, knowledge about relative elimination pathway contributions is needed in order to predict the total human clearance of drug candidates. In the present work, a training set of 18 drug compounds was used to describe the affiliations between in vitro sinusoidal uptake clearance and the fractional contributions of hepatic (metabolic and biliary) or renal clearance to overall in vivo elimination. By means of these quantitative relationships and using a validation set of 10 diverse drug molecules covering different (sub)classes of the Extended Clearance Concept Classification System (ECCCS), the relative contributions of elimination pathways were calculated and demonstrated to well correlate with human reference data. Likewise, ECM- and pathway-based predictions of total clearances from both data sets demonstrated a strong correlation with the observed clinical values with 26 out of 28 compounds within a three-fold deviation. Hence, total human clearance and relative contributions of elimination pathways were successfully predicted by the presented method using solely hepatocyte and microsome in vitro data.

  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.

  14. Development of a capillary electrophoretic method for determination of plasma clearance of iohexol in dogs and cats.

    PubMed

    Hellqvist, Alexander; Heiene, Reidun; De Baere, Siegrid; Croubels, Siska; Hedeland, Ylva

    2015-04-01

    Renal function can be monitored by estimation of the glomerular filtration rate (GFR), for example, through measurement of the plasma clearance of a marker that is freely filtrated through the kidney without reabsorption. It has been proposed that iohexol is the most accurate marker for GFR determination in cats and dogs. However, there is a need for a validated capillary electrophoretic method that covers the concentration range for a full curve clearance estimate of iohexol. In the final method, the plasma samples were protein precipitated and the supernatant was analyzed in a background electrolyte containing borate buffer (0.06 m, pH 10.0). The method developed was proved to be linear (concentration range 18- 2900 mg/L) and had a good precision (e.g. 2.3-2.9% at 88 mg/L) and accuracy (e.g. 101-105% at 88 mg/L). Finally, the method was compared with a previously published and validated HPLC-UV method by parallel analysis of clinical plasma samples from dogs and cats administered Omnipaque®. This comparison showed excellent agreement between the two methods and no proportional or systematic error was observed. The proposed method is simple and has a low cost per sample, which makes it applicable for routine analysis.

  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. 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

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

    PubMed Central

    Larsen, Poul S.; Riisgård, Hans Ulrik

    2012-01-01

    Summary 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

  18. Comparison of methods for calculating glomerular filtration rate: Technetium-99m-DTPA scintigraphic analysis, protein-free and whole-plasma clearance of technetium-99m-DTPA and iodine-125-iothalamate clearance

    SciTech Connect

    Goates, J.J.; Morton, K.A.; Whooten, W.W.; Greenberg, H.E.; Datz, F.L.; Handy, J.E.; Scuderi, A.J.; Haakenstad, A.O.; Lynch, R.E. )

    1990-04-01

    True glomerular filtration rate (GFR) was measured in normal volunteers and in patients with normal and impaired renal function by the iothalamate clearance (IC) method of Sigman. Within 24 hr, GFR was also determined by two other methods: technetium-99m- ({sup 99m}Tc) DTPA scintigraphic analysis (SA) utilizing a modification of the Gates computer program, and by measuring disappearance of {sup 99m}Tc-DTPA from whole plasma (WPC) and from protein-free ultrafiltered plasma (PFPC). Determinations of GFR by IC and by PFPC methods were virtually identical (mean absolute error 5.36 ml/min, r = 0.99, p greater than 0.05). GFRs measured in protein-free, ultrafiltered plasma differed significantly from those obtained from whole plasma only in sicker patients and in those taking multiple medications (in whom alterations in protein-binding of DTPA may be seen). The SA method correlated less well with the iodine-125-({sup 125}I) IC method than did either the protein-free or whole-plasma clearance methods (mean absolute error 32.36 ml/min, r = 0.74, p less than 0.05). However, the SA method provided useful information with respect to differential (split) renal function.

  19. 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.

  20. Does long-term creatine supplementation impair kidney function in resistance-trained individuals consuming a high-protein diet?

    PubMed Central

    2013-01-01

    Background The aim of this study was to determine the effects of creatine supplementation on kidney function in resistance-trained individuals ingesting a high-protein diet. Methods A randomized, double-blind, placebo-controlled trial was performed. The participants were randomly allocated to receive either creatine (20 g/d for 5 d followed by 5 g/d throughout the trial) or placebo for 12 weeks. All of the participants were engaged in resistance training and consumed a high-protein diet (i.e., ≥ 1.2 g/Kg/d). Subjects were assessed at baseline (Pre) and after 12 weeks (Post). Glomerular filtration rate was measured by 51Cr-EDTA clearance. Additionally, blood samples and a 24-h urine collection were obtained for other kidney function assessments. Results No significant differences were observed for 51Cr-EDTA clearance throughout the trial (Creatine: Pre 101.42 ± 13.11, Post 108.78 ± 14.41 mL/min/1.73m2; Placebo: Pre 103.29 ± 17.64, Post 106.68 ± 16.05 mL/min/1.73m2; group x time interaction: F = 0.21, p = 0.64). Creatinine clearance, serum and urinary urea, electrolytes, proteinuria, and albuminuria remained virtually unchanged. Conclusions A 12-week creatine supplementation protocol did not affect kidney function in resistance-trained healthy individuals consuming a high-protein diet; thus reinforcing the safety of this dietary supplement. Trial registration ClinicalTrials.gov NCT01817673 PMID:23680457

  1. 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.

  2. 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.

  3. 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.

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

    SciTech Connect

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

    2006-06-10

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

  5. 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.

  6. 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.

  7. 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)

  8. 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).

  9. 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).

  10. Malaria parasite clearance.

    PubMed

    White, Nicholas J

    2017-02-23

    Following anti-malarial drug treatment asexual malaria parasite killing and clearance appear to be first order processes. Damaged malaria parasites in circulating erythrocytes are removed from the circulation mainly by the spleen. Splenic clearance functions increase markedly in acute malaria. Either the entire infected erythrocytes are removed because of their reduced deformability or increased antibody binding or, for the artemisinins which act on young ring stage parasites, splenic pitting of drug-damaged parasites is an important mechanism of clearance. The once-infected erythrocytes returned to the circulation have shortened survival. This contributes to post-artesunate haemolysis that may follow recovery in non-immune hyperparasitaemic patients. As the parasites mature Plasmodium vivax-infected erythrocytes become more deformable, whereas Plasmodium falciparum-infected erythrocytes become less deformable, but they escape splenic filtration by sequestering in venules and capillaries. Sequestered parasites are killed in situ by anti-malarial drugs and then disintegrate to be cleared by phagocytic leukocytes. After treatment with artemisinin derivatives some asexual parasites become temporarily dormant within their infected erythrocytes, and these may regrow after anti-malarial drug concentrations decline. Artemisinin resistance in P. falciparum reflects reduced ring stage susceptibility and manifests as slow parasite clearance. This is best assessed from the slope of the log-linear phase of parasitaemia reduction and is commonly measured as a parasite clearance half-life. Pharmacokinetic-pharmacodynamic modelling of anti-malarial drug effects on parasite clearance has proved useful in predicting therapeutic responses and in dose-optimization.

  11. Cimetidine impairs nitrazepam clearance.

    PubMed

    Ochs, H R; Greenblatt, D J; Gugler, R; Müntefering, G; Locniskar, A; Abernethy, D R

    1983-08-01

    The effect of cimetidine on hepatic clearance of the benzodiazepine derivative nitrazepam was evaluated in healthy subjects. Six received a single 5- or 10-mg oral nitrazepam dose in the drug-free state and again with therapeutic cimetidine doses. Nitrazepam kinetics were determined from multiple serum concentrations measured during the 72 hr after each dose. Cimetidine had no effect on nitrazepam absorption kinetics, since peak serum nitrazepam concentration and time of peak concentration were not altered. Cimetidine did not alter nitrazepam volume of distribution, but cimetidine consistently reduced nitrazepam clearance, from a mean of 1.41 ml/min/kg in the control state to 1.17 ml/min/kg during cimetidine treatment. This resulted in prolongation of nitrazepam elimination t1/2 from 22.2 to 27.8 hr. Thus the ability of cimetidine to impair drug oxidation in man extends to the capacity for clearance of nitrazepam, a compound biotransformed mainly by nitroreduction.

  12. ADAPTIVE CLEARANCE CONTROL SYSTEMS FOR TURBINE ENGINES

    NASA Technical Reports Server (NTRS)

    Blackwell, Keith M.

    2004-01-01

    The Controls and Dynamics Technology Branch at NASA Glenn Research Center primarily deals in developing controls, dynamic models, and health management technologies for air and space propulsion systems. During the summer of 2004 I was granted the privilege of working alongside professionals who were developing an active clearance control system for commercial jet engines. Clearance, the gap between the turbine blade tip and the encompassing shroud, increases as a result of wear mechanisms and rubbing of the turbine blades on shroud. Increases in clearance cause larger specific fuel consumption (SFC) and loss of efficient air flow. This occurs because, as clearances increase, the engine must run hotter and bum more fuel to achieve the same thrust. In order to maintain efficiency, reduce fuel bum, and reduce exhaust gas temperature (EGT), the clearance must be accurately controlled to gap sizes no greater than a few hundredths of an inch. To address this problem, NASA Glenn researchers have developed a basic control system with actuators and sensors on each section of the shroud. Instead of having a large uniform metal casing, there would be sections of the shroud with individual sensors attached internally that would move slightly to reform and maintain clearance. The proposed method would ultimately save the airline industry millions of dollars.

  13. Advanced Thermal HPT Clearance Control

    NASA Technical Reports Server (NTRS)

    WojciechVoytek, Sak

    2006-01-01

    OBJECTIVE: Develop a fast acting HPT Active Clearance Control System to improve engine efficiency and reduce emissions CHALLENGE: Reduction of HPT blade clearance throughout engine operation System complexity, reliability and cost must remain comparable or surpass today s engines Reduced clearance may increase possibility of rubs

  14. Dynamics analysis of space robot manipulator with joint clearance

    NASA Astrophysics Data System (ADS)

    Zhao, Yang; Bai, Zheng Feng

    2011-04-01

    A computational methodology for analysis of space robot manipulator systems, considering the effects of the clearances in the joint, is presented. The contact dynamics model in joint clearance is established using the nonlinear equivalent spring-damp model and the friction effect is considered using the Coulomb friction model. The space robot system dynamic equation of manipulator with clearance is established. Then the dynamics simulation is presented and the dynamics characteristics of robot manipulator with clearance are analyzed. This work provides a practical method to analyze the dynamics characteristics of space robot manipulator with joint clearance and improves the engineering application. The computational methodology can predict the effects of clearance on space robot manipulator preferably, which is the basis of space robot manipulator design, precision analysis and ground test.

  15. Measuring foot placement and clearance during stair descent.

    PubMed

    Muhaidat, Jennifer; Kerr, Andrew; Rafferty, Danny; Skelton, Dawn A; Evans, Jonathan J

    2011-03-01

    Falls during stair descent are a serious problem and can lead to accidental death. Inappropriate foot placement on, and clearance over, steps have been identified as causes for falls on stairs. This study investigated a new method for measuring placement and clearance during stair descent in 10 healthy young subjects. The effect of foot length was accounted for during the measurement of foot placement by calculating the percentage length of the foot overhanging the step. Foot clearance was measured as the resultant of the minimum vertical and horizontal distances from the heel of the foot to the edge of the step. Clearance was divided into landing and passing clearance depending on the planned placement of the foot in relation to the step edge being cleared. Each subject performed seven trials of stairs descent. Mean (SD) and CV (SD) were 16% (6), 0.28 (0.15) for placement; 45.88 (10.05), 0.21 (0.07) for landing clearance; 107.25 (5.59), 0.25 (0.08) for passing clearance. There was no statistically significant effect of trial on placement and clearance (p>0.05). There was a significant effect of step number on landing and passing clearance (p=0.01, p<0.001 respectively). Landing and passing clearances were greater for the third step compared to the second step. Passing clearance was also significantly greater than landing clearance (p<0.001). The repeatable methods and findings from this study might be useful in providing a technical background and normal values for the design of future gait studies on stairs.

  16. 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.

  17. Comparison of glomerular filtration rate estimated by plasma clearance method with modification of diet in renal disease prediction equation and Gates method.

    PubMed

    Prasad, N; Barai, S; Gambhir, S; Parasar, D S; Ora, M; Gupta, A; Sharma, R K

    2012-03-01

    Glomerular filtration rate (GFR) prediction equations are widely used in clinical practice for quick assessment of kidney function. Gates method using radionuclide technique is an alternative to prediction equations for quick assessment of GFR. Aim of the study was to compare Gates method and modification of diet in renal disease (MDRD) equation in a sizeable patient population with wide range of renal function to evaluate their clinical utility. GFR was estimated in 897 subjects with wide range of renal function by gates method, and MDRD equation and results were compared against measured GFR. Subjects were divided in to 4 groups (0-30 ml, 31-60 ml, 61-90 ml, >90 ml) on the basis of measured GFR and comparison between two methods done through linear regression analysis. Analysis of R(2) indicated that 56% of the interindividual variability for Gates GFR was in accordance to variation in measured GFR, in the GFR range of (0-30 ml), this value dropped to 39% in the GFR range of 31-60 ml, 40% in the GFR range of 61-90 ml, 26.4% in the GFR range of >90 ml, the corresponding figure for MDRD GFR were 47.9%, 31.1%, 17.6% and 16.1%, respectively. Gates method is more precise for GFR estimation at all levels of renal function.

  18. Glomerular filtration rate in adults estimated from 123iodine-hippuran and 99mtechnetium-diethylenetriaminepenta-acetic acid gamma camera renography.

    PubMed

    Carlsen, O; Nathan, E

    1988-08-01

    In a retrospective study a close relationship was found between the rate constant for renal clearance of the radioactive indicator (lambda pk) and the glomerular filtration rate (GFR) measured by 51Cr-EDTA plasma clearance. The material comprised eighteen adult subjects submitted to 123I-hippuran gamma camera renography (IHGR) and twenty-two adult subjects to 99mTc-DTPA gamma camera renography (TDGR). The rate constant was calculated from a bi-exponential decomposition of the activity-time curve recorded within a small region of interest over the left ventricle. The total cleared renal fraction (TCRF) of the cardiac output with respect to the radioactive indicator has previously been shown to be closely related to GFR. A pooled estimate of GFR (GFRp) was calculated from the stochastically independent estimates of GFR based on lambda pk and TCRF. The comparison of GFRp with measured GFR was satisfactory and yielded substantially smaller standard deviations (SD) of GFRp than estimates based on lambda pk and TCRF separately. The standard deviations of GFRp were about 7 and 12 ml/min/1.73 m2 in IHGR for GFR equal to 50 and 100 ml/min/1.73 m2, respectively. The corresponding SD in TDGR were about 7 and 11 ml/min/1.73 m2. These standard deviations are sufficiently small for many clinical purposes and the method requires no blood samples or urine collections.

  19. CSF clearance in Alzheimer Disease measured with dynamic PET.

    PubMed

    de Leon, Mony J; Li, Yi; Okamura, Nobuyuki; Tsui, Wai H; Saint Louis, Les A; Glodzik, Lidia; Osorio, Ricardo S; Fortea, Juan; Butler, Tracy; Pirraglia, Elizabeth; Fossati, Silvia; Kim, Hee-Jin; Carare, Roxana O; Nedergaard, Maiken; Benveniste, Helene; Rusinek, Henry

    2017-03-16

    Evidence supporting the hypothesis that reduced cerebrospinal fluid (CSF) clearance is involved in the pathophysiology of Alzheimer's disease (AD) comes from primarily from rodent models. However, unlike rodents where predominant extra-cranial CSF egress is via olfactory nerves traversing the cribriform plate, human CSF clearance pathways are not well characterized. Using dynamic Positron Emission Tomography (PET) with (18)F-THK5117 a tracer for tau pathology, the ventricular CSF time activity was used as a biomarker for CSF clearance. We tested three hypotheses: 1. Extra-cranial CSF is detected at the superior turbinates; 2. CSF clearance is reduced in AD; and 3. CSF clearance is inversely associated with amyloid deposition. Methods: 15 subjects, 8 with AD and 7 normal control volunteers were examined with (18)F-THK5117. 10 subjects additionally received (11)C-PiB PET scans and 8 were PiB positive. Ventricular time activity curves (TAC) of (18)F-THK5117 were used to identify highly correlated TAC from extra-cranial voxels. Results: For all subjects, the greatest density of CSF positive extra-cranial voxels was in the nasal turbinates. Tracer concentration analyses validated the superior nasal turbinate CSF signal intensity. AD patients showed ventricular tracer clearance reduced by 23% and 66% fewer superior turbinate CSF egress sites. Ventricular CSF clearance was inversely associated with amyloid deposition. Conclusion: The human nasal turbinate is part of the CSF clearance system. Lateral ventricle and superior nasal turbinates CSF clearance abnormalities are found in AD. Ventricular CSF clearance reductions are associated with increased brain amyloid depositions. These data suggest that PET measured CSF clearance is a biomarker of potential interest in AD and other neurodegenerative diseases.

  20. Clearance Kinetics and Clearance Routes of Molecules From the Suprachoroidal Space After Microneedle Injection

    PubMed Central

    Chiang, Bryce; Wang, Ke; Ethier, C. Ross; Prausnitz, Mark R.

    2017-01-01

    Purpose To determine clearance kinetics and routes of clearance of molecules from the suprachoroidal space (SCS) of live New Zealand White rabbits. Methods Suprachoroidal space collapse rate and pressure changes after microneedle injection into SCS were determined. Fluorescent fundus images were acquired to determine clearance rates of molecules ranging in size from 332 Da to 2 MDa. Microneedle injections of fluorescein were performed, and samples were taken from various sites over time to determine amount of fluorescein exiting the eye. Clearance transport was modeled theoretically and compared with experimental data. Results After injection, pressures in SCS and vitreous humor spiked and returned to baseline within 20 minutes; there was no difference between these two pressures. Suprachoroidal space collapse occurred within 40 minutes. One hour after fluorescein injection, 46% of fluorescein was still present in the eye, 15% had transported across sclera, 6% had been cleared by choroidal vasculature, and 4% had exited via leakage pathways. Characteristic clearance time increased in proportion with molecular radius, but total clearance of 2 MDa FITC-dextran was significantly slower (21 days) than smaller molecules. These data generally agreed with predictions from a theoretical model of molecular transport. Conclusions Guided by experimental data in the context of model predictions, molecular clearance from SCS occurred in three regimes: (1) on a time scale of approximately 10 minutes, fluid and molecules exited SCS by diffusion into sclera and choroid, and by pressure-driven reflux via transscleral leakage sites; (2) in approximately 1 hour, molecules cleared from choroid by blood flow; and (3) in 1 to 10 hours, molecules cleared from sclera by diffusion and convection. PMID:28125841

  1. 32 CFR 644.517 - Clearance of Army lands.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 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...

  2. Comprehensive analysis of PEGylated liposome-associated proteins relating to the accelerated blood clearance phenomenon by combination with shotgun analysis and conventional methods.

    PubMed

    Kawanishi, Munehira; Hashimoto, Yosuke; Shimizu, Taro; Sagawa, Ikuko; Ishida, Tatsuhiro; Kiwada, Hiroshi

    2015-01-01

    PEGylated liposome, sterically stabilized by polyethylene glycol (PEG), results in reduced recognition of the liposome by the mononuclear phagocyte system. Recently, we reported regarding the accelerated blood clearance (ABC) phenomenon that PEGylated liposome is cleared very rapidly from blood circulation upon repeated injection. Anti-PEG IgM production and subsequent complement activation were crucial in causing the ABC phenomenon. However, there still remains the possibility that unknown plasma factors might affect the fate of PEGylated liposome that is subjected to the ABC phenomenon. A label-free approach to shotgun analysis is a great tool for characterizing proteins in a biological system. In this study, therefore, a shotgun analysis was employed to identify plasma protein bound on PEGylated liposome after the ABC phenomenon was induced in the mouse model. The analysis revealed that immunoglobulin and complement components (C1 and C3) are the major proteins. Subsequent analysis with enzyme-linked immunosorbent assay and Western blotting showed that the immunoglobulin was IgM and that the complement system was mainly activated via an anti-PEG IgM-mediated classical pathway. These results support our earlier assumptions-anti-PEG IgM and complement activation were the major causes of the ABC phenomenon. Our proposed analytical strategy would be expected to provide useful information for the development and design of the nanocarrier drug delivery system.

  3. 30 CFR 57.11010 - Stairstep clearance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Stairstep clearance. 57.11010 Section 57.11010... Escapeways Travelways-Surface and Underground § 57.11010 Stairstep clearance. Vertical clearance above stair... to indicate an impaired clearance....

  4. 30 CFR 57.11008 - Restricted clearance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Restricted clearance. 57.11008 Section 57.11008... Escapeways Travelways-Surface and Underground § 57.11008 Restricted clearance. Where restricted clearance creates a hazard to persons, the restricted clearance shall be conspicuously marked....

  5. 30 CFR 56.11010 - Stairstep clearance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Stairstep clearance. 56.11010 Section 56.11010... Stairstep clearance. Vertical clearance above stair steps shall be a minimum of seven feet, or suitable warning signs or similar devices shall be provided to indicate an impaired clearance....

  6. 28 CFR 524.74 - Activities clearance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Activities clearance. 524.74 Section 524... clearance. (a) Except as provided for in paragraph (b) of this section, the Warden is the clearance... Security cases. Central Office Inmate Monitoring Section staff shall be the clearance authority on...

  7. 30 CFR 56.11008 - Restricted clearance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Restricted clearance. 56.11008 Section 56.11008 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Restricted clearance. Where restricted clearance creates a hazard to persons, the restricted clearance...

  8. 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.

  9. Coupling Effect of Double Lungs on a VCV Ventilator with Automatic Secretion Clearance Function.

    PubMed

    Shi, Yan; Zhang, Bolun; Cai, Maolin; Xu, Weiqing

    2017-02-16

    For patients with mechanical ventilation, secretions in airway are harmful and sometimes even mortal, it's of great significance to clear secretion timely and efficiently. In this paper, a new secretion clearance method for VCV (volume-controlled ventilation) ventilator is put forward, and a secretion clearance system with a VCV ventilator and double lungs is designed. Furthermore, the mathematical model of the secretion clearance system is built and verified via experimental study. Finally, to illustrate the influence of key parameters of respiratory system and secretion clearance system on the secretion clearance characteristics, coupling effects of two lungs on VCV secretion clearance system are studied by an orthogonal experiment, it can be obtained that rise of tidal volume adds to efficiency of secretion clearance while effect of area, compliance and suction pressure on efficiency of secretion clearance needs further study. Rise of compliance improves bottom pressure of secretion clearance while rise of area, tidal volume and suction pressure decreases bottom pressure of secretion clearance. This paper can be referred to in researches of secretion clearance for VCV.

  10. 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.

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

    SciTech Connect

    Sasaki, Michiya; Ogino, Haruyuki; Hattori, Takatoshi

    2007-07-01

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

  12. Clearance of von Willebrand factor.

    PubMed

    Denis, Cécile V; Christophe, Olivier D; Oortwijn, Beatrijs D; Lenting, Peter J

    2008-02-01

    The life cycle of von Willebrand factor (VWF) comprises a number of distinct steps, ranging from the controlled expression of the VWF gene in endothelial cells and megakaryocytes to the removal of VWF from the circulation. The various aspects of VWF clearance have been the objects of intense research in the last few years, stimulated by observations that VWF clearance is a relatively common component of the pathogenesis of type 1 von Willebrand disease (VWD). Moreover, improving the survival of VWF is now considered as a viable therapeutic strategy to prolong the half-life of factor VIII in order to optimise treatment of haemophilia A. The present review aims to provide an overview of recent findings with regard to the molecular basis of VWF clearance. A number of parameters have been identified that influence VWF clearance, including its glycosylation profile and a number of VWF missense mutations. In addition, in-vivo studies have been used to identify cells that contribute to the catabolism of VWF, providing a starting point for the identification of receptors that mediate the cellular uptake of VWF. Finally, we discuss recent data describing chemically modification of VWF as an approach to prolong the half-life of the VWF/FVIII complex.

  13. Aerial Refueling Clearance Initiation Request

    DTIC Science & Technology

    2016-07-14

    and receiver agencies. The AR Clearance Initiation Request document recognizes the requirement for definitive aerial refueling agreements between...include directions for the development or content of these contractual agreements. 15. –SUBJECT TERMS See Document Terms and Definitions , Page 8 16...7 Terms and Definitions

  14. Myeloid cell turnover and clearance

    PubMed Central

    Janssen, William J.; Bratton, Donna L.; Jakubzick, Claudia V.; Henson, Peter M.

    2016-01-01

    Given the dual and intrinsically contradictory roles for myeloid cells in both protective and yet also damaging effects of inflammatory and immunological processes we suggest that it is important to consider the mechanisms and circumstances by which these cells are removed, either in the normal unchallenged state or during inflammation or disease. In this essay we address these subjects from a conceptual perspective, focusing as examples on four main myeloid cell types (neutrophils, monocytes, macrophages and myeloid dendritic cells) and their clearance from the circulation or from naïve and inflamed tissues. While the primary clearance process appears to involve endocytic uptake into macrophages, various tissue cell types can also recognize and remove dying cells though their overall quantitative contribution is unclear. In fact, surprisingly, given the wealth of study in this area over the last 30 years, our conclusion is that we are still challenged with substantial lack of mechanistic and regulatory understanding of when, how and by what mechanisms migratory myeloid cells come to die, are recognized as needing to be removed and indeed the precise processes of uptake of either the intact or fragmented cells. This reflects the extreme complexity and inherent redundancy of the clearance processes and argues for substantial investigative effort in this arena. In addition, it leads us to a sense that approaches to significant therapeutic modulation of selective myeloid clearance is still a long way off. PMID:27837740

  15. Microwave Blade Tip Clearance System: An Update

    NASA Technical Reports Server (NTRS)

    Geisheimer, Jon

    2006-01-01

    Newer engines use compressor bleed air and a model to close clearances open loop. Measuring clearances and closing the control loop can add additional efficiencies. Tip clearance control has been identified as a key technology for future engines Additional benefits in prognostics, NSMS, and condition-based maintenance. In the HPT for every 1 mil improvement in clearance: a) SFC decreases 0.1%; and b) EGT margin increases 1 C.

  16. 14 CFR 23.925 - Propeller clearance.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., an airplane with an aft mounted propeller must be designed such that the propeller will not contact...) Structural clearance. There must be— (1) At least one inch radial clearance between the blade tips and the... least one-half inch longitudinal clearance between the propeller blades or cuffs and stationary parts...

  17. 14 CFR 23.925 - Propeller clearance.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., an airplane with an aft mounted propeller must be designed such that the propeller will not contact...) Structural clearance. There must be— (1) At least one inch radial clearance between the blade tips and the... least one-half inch longitudinal clearance between the propeller blades or cuffs and stationary parts...

  18. 14 CFR 23.925 - Propeller clearance.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., an airplane with an aft mounted propeller must be designed such that the propeller will not contact...) Structural clearance. There must be— (1) At least one inch radial clearance between the blade tips and the... least one-half inch longitudinal clearance between the propeller blades or cuffs and stationary parts...

  19. 14 CFR 23.925 - Propeller clearance.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., an airplane with an aft mounted propeller must be designed such that the propeller will not contact...) Structural clearance. There must be— (1) At least one inch radial clearance between the blade tips and the... least one-half inch longitudinal clearance between the propeller blades or cuffs and stationary parts...

  20. 29 CFR 1917.113 - Clearance heights.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Clearance heights. 1917.113 Section 1917.113 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) MARINE TERMINALS Terminal Facilities § 1917.113 Clearance heights. Clearance heights shall...

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. Security Clearances: Consideration of Sexual Orientation in the Clearance Process.

    DTIC Science & Technology

    1995-03-01

    Until about 1991, when agencies began to change their security policies and practices regarding sexual orientation , there were a number of documented...cases where defense civilian or contractor employees’ security clearances were denied or revoked because of their sexual orientation . However our...forward and discuss their cases. Notwithstanding these limitations, our work disclosed no evidence that sexual orientation has been used as a criterion

  10. Removal - An alternative to clearance

    SciTech Connect

    Feinhals, J.; Kelch, A.; Kunze, V.

    2007-07-01

    This presentation shows the differences between the application of clearance and removal, both being procedures for materials leaving radiation protection areas permanently. The differentiation will be done on the basis of the German legislation but may be also applicable for other national legislation. For clearance in Germany two basic requirements must be given, i.e. that the materials are activated or contaminated and that they result from the licensed use or can be assigned to the scope of the license. Clearance needs not to be applied to objects in Germany which are to be removed only temporarily from controlled areas with the purpose of repair or reuse in other controlled areas. In these cases only the requirements of contamination control apply. In the case of removal it must either be proved by measurements that the relevant materials are neither activated nor contaminated or that the materials result from areas where activation or contamination is impossible due to the operational history considering operational procedures and events. If the material is considered neither activated nor contaminated there is no need for a clearance procedure. Therefore, these materials can be removed from radiation protection areas and the removal is in the responsibility of the licensee. Nevertheless, the removal procedure and the measuring techniques to be applied for the different types of materials need an agreement from the competent authority. In Germany a maximum value of 10% of the clearance values has been established in different licenses as a criterion for the application of removal. As approximately 2/3 of the total mass of a nuclear power plant is not expected to be contaminated or activated there is a need for such a procedure of removal for this non contaminated material without any regulatory control especially in the case of decommissioning. A remarkable example is NPP Stade where in the last three years more than 8600 Mg were disposed of by removal and

  11. Comparison of serum iohexol clearance and plasma creatinine clearance in clinically normal horses.

    PubMed

    Wilson, Katherine E; Wilcke, Jeff R; Crisman, Mark V; Ward, Daniel L; McKenzie, Harold C; Scarratt, W Kent

    2009-12-01

    Objective-To determine whether a limited sampling time method based on serum iohexol clearance (Cl(iohexol)) would yield estimates of glomerular filtration rate (GFR) in clinically normal horses similar to those for plasma creatinine clearance (Cl(creatinine)). Animals-10 clinically normal adult horses. Procedures-A bolus of iohexol (150 mg/kg) was administered IV, and serum samples were obtained 5, 20, 40, 60, 120, 240, and 360 minutes after injection. Urinary clearance of exogenous creatinine was measured during three 20-minute periods. The GFR determined by use of serum Cl(iohexol) and plasma Cl(creatinine) was compared with limits of agreement plots. Results-Values obtained for plasma Cl(creatinine) ranged from 1.68 to 2.69 mL/min/kg (mean, 2.11 mL/min/kg). Mean serum Cl(iohexol) was 2.38 mL/min/kg (range, 1.95 to 3.33 mL/min/kg). Limits of agreement plots indicated good agreement between the methods. Conclusions and Clinical Relevance-Use of serum Cl(iohexol) yielded estimates of GFR in clinically normal adult horses similar to those for plasma Cl(creatinine). This study was the first step in the evaluation of the use of serum Cl(iohexol) for estimating GFR in adult horses.

  12. Aerial Refueling Clearance Process Guide

    DTIC Science & Technology

    2014-08-21

    08-2014 2. REPORT TYPE Guidance Document 3. DATES COVERED 2008-2014 4. TITLE AND SUBTITLE Aerial Refueling Clearance Process Guide Attachment: Aerial...ATP-3.3.4.2 covers general operational procedures for AR and national/organizational SRDs cover data and procedures specific to their AR platforms...Receptacle, Probe/Drogue, and BDA Kit. 3.1.3 The items for assessment consideration cover several areas of interface for both the tanker and the

  13. Relationships among glomerular filtration rate, albuminuria, and autonomic nerve function in insulin-dependent and non-insulin-dependent diabetes mellitus.

    PubMed

    Sterner, N G; Nilsson, H; Rosén, U; Lilja, B; Sundkvist, G

    1997-01-01

    The associations among autonomic neuropathy, urinary albumin excretion, and glomerular filtration rate (GFR) measured with 51Cr-EDTA and iohexol clearance were studied in 41 patients with insulin-dependent diabetes mellitus (IDDM) and 15 patients with non-insulin-dependent diabetes mellitus (NIDDM). The study showed that increased urinary albumin excretion was more common in NIDDM than in IDDM. In contrast with IDDM, albuminuria in NIDDM was not related to GFR. Autonomic neuropathy was common in IDDM as well as in NIDDM, and also in patients without nephropathy, but was not connected with hyperfiltration. Low brake index, an ortostatic autonomic index, was associated with nephropathy in NIDDM. Iohexol, a non-ionic contrast medium, was found to be a useful alternative to 51Cr-EDTA for determination of GFR. Moreover, comparison between conventional four-sample plasma clearance and single-sample clearance showed a close correlation. Accordingly, assessment of GFR using a single plasma sample provides reliable results even at high GFR values.

  14. Prediction of drug clearance in children.

    PubMed

    Foissac, Frantz; Bouazza, Naïm; Valade, Elodie; De Sousa Mendes, Mailys; Fauchet, Floris; Benaboud, Sihem; Hirt, Déborah; Tréluyer, Jean-Marc; Urien, Saïk

    2015-07-01

    The pediatric population is often exposed to drugs without sufficient knowledge about pharmacokinetics. The prediction of accurate clearance values in children, especially in neonates and infants, will improve the rational in dosing decisions. Drug clearances from birth to adulthood were compiled after a systematic review of pharmacokinetic reports. The analysis was performed using NONMEM. Clearance predictions were then evaluated by external validation. Prediction errors were also compared with those obtained from weight-based allometric scaling and physiologically based clearance (PBCL) models. For the analysis, 17 and 15 drugs were used for model building and external validation, respectively. A model based on the adult drug clearance value and taking into account both weight and age was retained. Age-related maturation of clearance reached 90% of the adult value within 1.5 years of life. For children less than 2 years old, allometric scaling alone systematically overestimated clearances. Accounting for age improved the clearance prediction in the 6 months-2 years age group (prediction error < 25%). Predictions obtained from the PBCL approach were close to our results. This analysis established a single equation using the adult clearance value as well as individual age and weight to predict drug clearance in children older than 6 months.

  15. 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.

  16. 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.

  17. 78 FR 77027 - Overhead Clearance (Air-Draft) Accidents

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-20

    ... address the problem of overhead clearance (air-draft) accidents. In its petition, which calls for vessel... methods: (1) Federal eRulemaking Portal: http://www.regulations.gov . (2) Fax: 202-493-2251. (3) Mail..., ] contact LCDR William Nabach, Office of Vessel and Facility Operating Standards (CG-OES-2), U.S....

  18. Elastic clearance change in axisymmetric shearing process

    NASA Astrophysics Data System (ADS)

    Yoshida, Yoshinori

    2016-10-01

    An axisymmetric shearing experiment is conducted for a sheet of low carbon steel and stainless steel. Elastic change in the clearance between punch and die is measured. The increase of the clearance in shearing is confirmed and the influence of sheared material's flow stress on the clearance change is shown. Finite element analysis (FEA) of shearing with Gurson-Tvergaard-Needlman model (GTN model) is conducted for shearing of the carbon steels with rigid tools as a numerical experiment. Burr height is predicted in the FEA and the result is compared with the experimental result. In addition, the influence of the clearance on stress state in the material is investigated.

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

    SciTech Connect

    Geraci, J.P.; Jackson, K.L.; Mariano, M.S.; Michieli, B.M. )

    1990-04-01

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

  20. Human pharmacokinetics of iohexol. A new nonionic contrast medium

    SciTech Connect

    Olsson, B.; Aulie, A.; Sveen, K.; Andrew, E.

    1983-03-01

    The pharmacokinetics of iohexol, a new nonionic, water-soluble contrast medium, have been determined after intravenous injection in 20 healthy volunteers, at four different dose levels (125-500 mg I/kg). The apparent volume of distribution was 0.27 1/kg, indicating distribution in the extracellular water. The biologic half-life was 121 minutes, comparable with that of other intravascular contrast media. Iohexol was excreted completely unmetabolized in the urine, with a 100% recovery 24 hours after injection. A comparison of iohexol and chromium-51 (/sup 51/Cr)-EDTA clearances indicates that iohexol is mainly excreted by glomerular filtration. The /sup 51/Cr-EDTA clearance was the same when injected separately and concomitantly with iohexol, indicating that glomerular filtration rate is not affected by iohexol. No dose dependency was observed in the investigated parameters t1/2 alpha, t1/2 beta, Vd, ClT or ClR. Iohexol pharmacokinetics are in correspondence with previously reported data on intravascular contrast media.

  1. N-linked glycan truncation causes enhanced clearance of plasma-derived von Willebrand factor.

    PubMed

    O'Sullivan, J M; Aguila, S; McRae, E; Ward, S E; Rawley, O; Fallon, P G; Brophy, T M; Preston, R J S; Brady, L; Sheils, O; Chion, A; O'Donnell, J S

    2016-12-01

    Essentials von Willebrands factor (VWF) glycosylation plays a key role in modulating in vivo clearance. VWF glycoforms were used to examine the role of specific glycan moieties in regulating clearance. Reduction in sialylation resulted in enhanced VWF clearance through asialoglycoprotein receptor. Progressive VWF N-linked glycan trimming resulted in increased macrophage-mediated clearance. Click to hear Dr Denis discuss clearance of von Willebrand factor in a free presentation from the ISTH Academy SUMMARY: Background Enhanced von Willebrand factor (VWF) clearance is important in the etiology of both type 1 and type 2 von Willebrand disease (VWD). In addition, previous studies have demonstrated that VWF glycans play a key role in regulating in vivo clearance. However, the molecular mechanisms underlying VWF clearance remain poorly understood. Objective To define the molecular mechanisms through which VWF N-linked glycan structures influence in vivo clearance. Methods By use of a series of exoglycosidases, different plasma-derived VWF (pd-VWF) glycoforms were generated. In vivo clearance of these glycoforms was then assessed in VWF(-/-) mice in the presence or absence of inhibitors of asialoglycoprotein receptor (ASGPR), or following clodronate-induced macrophage depletion. Results Reduced amounts of N-linked and O-linked sialylation resulted in enhanced pd-VWF clearance modulated via ASGPR. In addition to this role of terminal sialylation, we further observed that progressive N-linked glycan trimming also resulted in markedly enhanced VWF clearance. Furthermore, these additional N-linked glycan effects on clearance were ASGPR-independent, and instead involved enhanced macrophage clearance that was mediated, at least in part, through LDL receptor-related protein 1. Conclusion The carbohydrate determinants expressed on VWF regulate susceptibility to proteolysis by ADAMTS-13. In addition, our findings now further demonstrate that non-sialic acid carbohydrate

  2. 14 CFR 25.925 - Propeller clearance.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... following: (a) Ground clearance. There must be a clearance of at least seven inches (for each airplane with nose wheel landing gear) or nine inches (for each airplane with tail wheel landing gear) between each propeller and the ground with the landing gear statically deflected and in the level takeoff, or...

  3. 14 CFR 25.925 - Propeller clearance.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... following: (a) Ground clearance. There must be a clearance of at least seven inches (for each airplane with nose wheel landing gear) or nine inches (for each airplane with tail wheel landing gear) between each propeller and the ground with the landing gear statically deflected and in the level takeoff, or...

  4. 14 CFR 25.925 - Propeller clearance.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... following: (a) Ground clearance. There must be a clearance of at least seven inches (for each airplane with nose wheel landing gear) or nine inches (for each airplane with tail wheel landing gear) between each propeller and the ground with the landing gear statically deflected and in the level takeoff, or...

  5. 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;...

  6. 19 CFR 122.77 - Clearance certificate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 1 2011-04-01 2011-04-01 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;...

  7. 19 CFR 122.77 - Clearance certificate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 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. 19 CFR 122.77 - Clearance certificate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 1 2013-04-01 2013-04-01 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;...

  9. 19 CFR 122.77 - Clearance certificate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 1 2012-04-01 2012-04-01 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;...

  10. 15 CFR 752.15 - Export clearance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 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 SPECIAL COMPREHENSIVE LICENSE § 752.15 Export clearance. (a) Shipper's Export Declaration (SED) or Automated...

  11. 14 CFR 25.925 - Propeller clearance.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... nose wheel landing gear) or nine inches (for each airplane with tail wheel landing gear) between each propeller and the ground with the landing gear statically deflected and in the level takeoff, or taxiing... the corresponding landing gear strut bottomed. (b) Water clearance. There must be a clearance of...

  12. 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....

  13. 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....

  14. 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...

  15. 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...

  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, 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...

  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, 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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....

  5. 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....

  6. 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....

  7. 30 CFR 56.11010 - Stairstep clearance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Stairstep clearance. 56.11010 Section 56.11010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... warning signs or similar devices shall be provided to indicate an impaired clearance....

  8. 30 CFR 56.11010 - Stairstep clearance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Stairstep clearance. 56.11010 Section 56.11010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... warning signs or similar devices shall be provided to indicate an impaired clearance....

  9. Nasal mucociliary clearance after radiation therapy.

    PubMed

    Stringer, S P; Stiles, W; Slattery, W H; Krumerman, J; Parsons, J T; Mendenhall, W M; Cassisi, N J

    1995-04-01

    Irradiation has been demonstrated to cause decreased mucociliary clearance in animal models. We sought to verify this effect clinically by using the saccharin transport test to evaluate nasal mucociliary clearance in 9 patients previously treated with radiation therapy to the nasal cavity. The patients also completed a questionnaire examining the prevalence of nasal symptoms before and after radiation therapy. Patients who received radiation therapy had no clearance of saccharin from the nasal cavity at a minimum of 20 minutes. The controls had a median clearance time of 5 minutes. The patients noted a higher prevalence of nasal congestion, drainage, and facial pain after radiation therapy. This study demonstrates that radiation therapy to the nasal cavity causes a decrease in nasal mucociliary clearance. This alteration should be considered when selecting therapy for malignancies in the nasal area.

  10. 19 CFR 4.61 - Requirements for clearance.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... optional clearance locations. (b) When clearance required. Under certain circumstances, American vessels.... While American vessels transporting unentered foreign merchandise must fully comply with usual clearance procedures, American vessels carrying no unentered foreign merchandise but that have in-bond...

  11. 77 FR 21989 - Critical Infrastructure Private Sector Clearance Program Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-12

    ... SECURITY Critical Infrastructure Private Sector Clearance Program Request AGENCY: National Protection and... information provided. SUPPLEMENTARY INFORMATION: The Critical Infrastructure Private Sector Clearance Program (PSCP) sponsors clearances for private sector partners who are responsible for critical...

  12. Spontaneous Clearance of Viral Infections by Mesoscopic Fluctuations

    PubMed Central

    Chaudhury, Srabanti; Perelson, Alan S.; Sinitstyn, Nikolai A.

    2012-01-01

    Spontaneous disease extinction can occur due to a rare stochastic fluctuation. We explore this process, both numerically and theoretically, in two minimal models of stochastic viral infection dynamics. We propose a method that reduces the complexity in models of viral infections so that the remaining dynamics can be studied by previously developed techniques for analyzing epidemiological models. Using this technique, we obtain an expression for the infection clearance time as a function of kinetic parameters. We apply our theoretical results to study stochastic infection clearance for specific stages of HIV and HCV dynamics. Our results show that the typical time for stochastic clearance of a viral infection increases exponentially with the size of the population, but infection still can be cleared spontaneously within a reasonable time interval in a certain population of cells. We also show that the clearance time is exponentially sensitive to the viral decay rate and viral infectivity but only linearly dependent on the lifetime of an infected cell. This suggests that if standard drug therapy fails to clear an infection then intensifying therapy by adding a drug that reduces the rate of cell infection rather than immune modulators that hasten infected cell death may be more useful in ultimately clearing remaining pockets of infection. PMID:22693646

  13. 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.

  14. 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.

  15. 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.

  16. Maintenance of superior mesenteric arterial perfusion prevents increased intestinal mucosal permeability in endotoxic pigs

    SciTech Connect

    Fink, M.P.; Kaups, K.L.; Wang, H.L.; Rothschild, H.R. )

    1991-08-01

    Lipopolysaccharide increases intestinal mucosal permeability to hydrophilic compounds such as chromium 51-labeled edetate (51Cr-EDTA). The authors sought to determine whether this phenomenon is partly mediated by lipopolysaccharide-induced mesenteric hypoperfusion. They assessed permeability in an isolated segment of ileum by measuring plasma-to-lumen clearances (C) for two probes, 51Cr-EDTA and urea, and expressing the results as a ratio (CEDTA/CUREA). In control pigs (n = 6) resuscitated with Ringer's lactate (RL), mucosal permeability was unchanged during the 210-minute period of observation. In pigs (n = 7) infused with lipopolysaccharide (50 micrograms/kg) and similarly resuscitated with RL, mesenteric perfusion (Qsma) decreased significantly and permeability increased progressively and significantly. When endotoxic pigs (n = 6) were resuscitated with a regimen (RL plus hetastarch plus dobutamine) that preserved normal Qsma, lipopolysaccharide-induced mucosal hyperpermeability was prevented. Resuscitation of endotoxic pigs (n = 6) with RL plus hetastarch provided intermediate protection against both mesenteric hypoperfusion and increased permeability. These data suggest that diminished Qsma contributes to impaired ileal mucosal barrier function in experimental endotoxicosis.

  17. Interspecies scaling and prediction of human clearance: comparison of small- and macro-molecule drugs

    PubMed Central

    Huh, Yeamin; Smith, David E.; Feng, Meihau Rose

    2014-01-01

    Human clearance prediction for small- and macro-molecule drugs was evaluated and compared using various scaling methods and statistical analysis.Human clearance is generally well predicted using single or multiple species simple allometry for macro- and small-molecule drugs excreted renally.The prediction error is higher for hepatically eliminated small-molecules using single or multiple species simple allometry scaling, and it appears that the prediction error is mainly associated with drugs with low hepatic extraction ratio (Eh). The error in human clearance prediction for hepatically eliminated small-molecules was reduced using scaling methods with a correction of maximum life span (MLP) or brain weight (BRW).Human clearance of both small- and macro-molecule drugs is well predicted using the monkey liver blood flow method. Predictions using liver blood flow from other species did not work as well, especially for the small-molecule drugs. PMID:21892879

  18. Measurement of the plasma clearance of urographic contrast media for the determination of glomerular filtration rate

    SciTech Connect

    O'Reilly, P.H.; Jones, D.A.; Farah, N.B.

    1988-01-01

    Further experience with a new method to determine glomerular filtration rate is presented. The method depends on measurement by an x-ray fluorescence technique of the plasma disappearance of the injected iodine in standard nonionic radiographic contrast media used during excretory urography. The results of comparison of contrast clearance with /sup 99m/technetium-diethylenetriaminepentaacetic acid clearance in 33 cases showed excellent agreement with a correlation coefficient of 0.95. Reproducibility of the contrast clearance method was confirmed by repeated examination of 10 plasma samples at weekly intervals for 6 weeks, the results of which showed no significant differences. The contrast clearance technique for the measurement of glomerular filtration rate during excretory urography is simple, quick and accurate, and merits further development.

  19. Interspecies scaling and prediction of human clearance: comparison of small- and macro-molecule drugs.

    PubMed

    Huh, Yeamin; Smith, David E; Feng, Meihau Rose

    2011-11-01

    Human clearance prediction for small- and macro-molecule drugs was evaluated and compared using various scaling methods and statistical analysis. Human clearance is generally well predicted using single or multiple species simple allometry for macro- and small-molecule drugs excreted renally. The prediction error is higher for hepatically eliminated small-molecules using single or multiple species simple allometry scaling, and it appears that the prediction error is mainly associated with drugs with low hepatic extraction ratio (Eh). The error in human clearance prediction for hepatically eliminated small-molecules was reduced using scaling methods with a correction of maximum life span (MLP) or brain weight (BRW). Human clearance of both small- and macro-molecule drugs is well predicted using the monkey liver blood flow method. Predictions using liver blood flow from other species did not work as well, especially for the small-molecule drugs.

  20. 14 CFR 25.925 - Propeller clearance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... attitude, whichever is most critical. In addition, there must be positive clearance between the propeller and the ground when in the level takeoff attitude with the critical tire(s) completely deflated...

  1. Shear-Joint Capability Versus Bolt Clearance

    NASA Technical Reports Server (NTRS)

    Lee, H. M.

    1994-01-01

    NASA Technical Memorandum presents theoretical study of relationships between load-bearing capabilities of shear joints that comprise plates clamped together by multiple bolts and clearances between bolts and boltholes in those joints.

  2. Shear joint capability versus bolt clearance

    NASA Technical Reports Server (NTRS)

    Lee, H. M.

    1992-01-01

    The results of a conservative analysis approach into the determination of shear joint strength capability for typical space-flight hardware as a function of the bolt-hole clearance specified in the design are presented. These joints are comprised of high-strength steel fasteners and abutments constructed of aluminum alloys familiar to the aerospace industry. A general analytical expression was first arrived at which relates bolt-hole clearance to the bolt shear load required to place all joint fasteners into a shear transferring position. Extension of this work allowed the analytical development of joint load capability as a function of the number of fasteners, shear strength of the bolt, bolt-hole clearance, and the desired factor of safety. Analysis results clearly indicate that a typical space-flight hardware joint can withstand significant loading when less than ideal bolt hole clearances are used in the design.

  3. 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.

  4. 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.

  5. 2015 Annual Report on Security Clearance Determinations

    DTIC Science & Technology

    2016-06-28

    preceding fiscal year that resulted in a denial or revocation of a security clearance...and o more than 1 year. iii. Percentage of reviews during the preceding fiscal year that resulted in a denial or revocation of a security clearance...1,322 in FY 2014 to 2,526 in FY 20154. iii. The percentage of reviews during the preceding fiscal year that resulted in a denial or revocation of a

  6. Bioaerosols in the lungs of subjects with different ages—Part 2: clearance modeling

    PubMed Central

    2017-01-01

    Background The present contribution deals with theoretical aspects regarding biogenic particle clearance from various lung structures of probands with different ages (1, 5, 15, 20 y). With reference to part 1 of the study, particles varying in size and shape are subject to a detailed analysis. The main goal of the investigation consists in an increase of our knowledge concerning the clearance behaviour of bioparticles and its dependence upon various physiological and anatomical factors. Methods Theoretical clearance of biogenic particles was subdivided into four main phases, namely fast bronchial clearance, slow bronchial clearance, fast alveolar clearance, and slow alveolar clearance. All of these phases were simulated by using a well validated stochastic modeling approach, where the main focus is set on the randomly varied particle mass transfer between main compartments of the human respiratory tract. Whilst effects of particle geometry on clearance were approximated by application of the projective-diameter concept, age dependence of the particle removal process was expressed by the experimentally proven relationship between bronchial mucus velocities and morphometry of the airway tree. Results According to the results of the theoretical simulations efficiency of fast bronchial clearance, expressed by the 24-h-retention value, exhibits a negative correlation with proband's age, whereas the other clearance phases are characterized by a rather conservative behaviour among the different age categories. Highest clearance rates may be observed for very fine (<0.01 µm) and very coarse particles (>5 µm) preferentially deposited in the upper bronchial airways, whilst large particles accumulated in the alveoli may be stored there for several months to years. Conclusions The study comes to the conclusion that infants and children dispose of an enhanced bronchial clearance efficiency with respect to adolescents and adults, which results in a faster removal of

  7. 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.

  8. Relation of HLA class I and II supertypes with spontaneous clearance of hepatitis C virus.

    PubMed

    Kuniholm, M H; Anastos, K; Kovacs, A; Gao, X; Marti, D; Sette, A; Greenblatt, R M; Peters, M; Cohen, M H; Minkoff, H; Gange, S J; Thio, C L; Young, M A; Xue, X; Carrington, M; Strickler, H D

    2013-01-01

    Human leukocyte antigen (HLA) genotype has been associated with the probability of spontaneous clearance of hepatitis C virus (HCV). However, no prior studies have examined whether this relationship may be further characterized by grouping HLA alleles according to their supertypes, defined by their binding capacities. There is debate regarding the most appropriate method to define supertypes. Therefore, previously reported HLA supertypes (46 class I and 25 class II) were assessed for their relation with HCV clearance in a population of 758 HCV-seropositive women. Two HLA class II supertypes were significant in multivariable models that included: (i) supertypes with significant or borderline associations with HCV clearance after adjustment for multiple tests, and (ii) individual HLA alleles not part of these supertypes, but associated with HCV clearance in our prior study in this population. Specifically, supertype DRB3 (prevalence ratio (PR)=0.4; P=0.004) was associated with HCV persistence, whereas DR8 (PR=1.8; P=0.01) was associated with HCV clearance. Two individual alleles (B*57:01 and C*01:02) associated with HCV clearance in our prior study became nonsignificant in analysis that included supertypes, whereas B*57:03 (PR=1.9; P=0.008) and DRB1*07:01 (PR=1.7; P=0.005) retained their significance. These data provide epidemiologic support for the significance of HLA supertypes in relation to HCV clearance.

  9. Experimental and Clinical Evaluation of Predilution and Postdilution Continuous Venovenous Hemofiltration on Clearance Characteristics.

    PubMed

    Chihara, Shinya; Masuda, Yoshiki; Yamakage, Michiaki

    We compared the clearance characteristics of low-to-high molecular weight substances during pre-and postdilution continuous venovenous hemofiltration (CVVH) in experimental and clinical conditions. Experimental circuits for pre- and postdilution CVVH were prepared using a test solution containing creatinine (110 Da), inulin (5,000 Da), interleukin (IL)-8 (8,000 Da), IL-6 (22,000 Da), and tumor necrosis factor (TNF)-α (51,000 Da). Quantity of test solution flow and filtration flow (QF) were set to 150 ml/min and 10, 20, and 35 ml/min, respectively. Clinical CVVH settings were blood flow (QB): 150 ml/min and QF: 35 ml/min. Samples were obtained from pre- and posthemofilters, and clearance of target substances was determined during pre- and postdilution CVVH in experimental and clinical conditions. Clearance changed according to QF during both pre- and postdilution CVVH in the experiment. Clearance of creatinine, inulin (experiment only), and IL-8 during postdilution CVVH was superior to that during predilution CVVH. Few differences were seen in clearance of IL-6 and TNF-α between dilution methods in the experiment and clinical practice. Clearance of IL-8 and IL-6 decreased during postdilution CVVH over 24 hr but did not change during predilution CVVH in clinical practice. Predilution CVVH is useful for stable cytokine clearance in septic patients with acute kidney injury.

  10. 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...

  11. 48 CFR 245.7203 - Assigning plant clearance case numbers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Assigning plant clearance....7203 Assigning plant clearance case numbers. (a) Use a three-part, 11-character number constructed as... clearance number on DD Form 1635, Plant Clearance Case Register, or mechanized equivalent....

  12. 48 CFR 245.7202 - Establishing a plant clearance case.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... clearance case. 245.7202 Section 245.7202 Federal Acquisition Regulations System DEFENSE ACQUISITION....7202 Establishing a plant clearance case. (a) Upon receipt of an acceptable inventory schedule or a DD Form 1342, DoD Property Record, the plant clearance officer shall establish a plant clearance case...

  13. 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 clearance services. (a) Responsibilities of closing agents. Services to be provided to the agency and...

  14. 48 CFR 945.603-70 - Plant clearance function.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 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...

  15. 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...

  16. 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...

  17. 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...

  18. 32 CFR 644.517 - Clearance of Army lands.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 4 2013-07-01 2013-07-01 false Clearance of Army lands. 644.517 Section 644.517... ESTATE HANDBOOK Disposal Clearance of Explosive Hazards and Other Contamination from Proposed Excess Land and Improvements § 644.517 Clearance of Army lands. The responsibility for performing clearance...

  19. 32 CFR 644.517 - Clearance of Army lands.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 4 2012-07-01 2011-07-01 true Clearance of Army lands. 644.517 Section 644.517... ESTATE HANDBOOK Disposal Clearance of Explosive Hazards and Other Contamination from Proposed Excess Land and Improvements § 644.517 Clearance of Army lands. The responsibility for performing clearance...

  20. 32 CFR 644.517 - Clearance of Army lands.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 4 2014-07-01 2013-07-01 true Clearance of Army lands. 644.517 Section 644.517... ESTATE HANDBOOK Disposal Clearance of Explosive Hazards and Other Contamination from Proposed Excess Land and Improvements § 644.517 Clearance of Army lands. The responsibility for performing clearance...

  1. 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... ESTATE HANDBOOK Disposal Clearance of Explosive Hazards and Other Contamination from Proposed Excess Land and Improvements § 644.517 Clearance of Army lands. The responsibility for performing clearance...

  2. 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.

  3. Nonlinear dynamic characteristic analysis of jointed beam with clearance

    NASA Astrophysics Data System (ADS)

    Zhang, Jing; Guo, Hong-Wei; Liu, Rong-Qiang; Wu, Juan; Kou, Zi-Ming; Deng, Zong-Quan

    2016-12-01

    The impact and elasticity of discontinuous beams with clearance frequently affect the dynamic response of structures used in space missions. This study investigates the dynamic response of jointed beams which are the periodic units of deployable structures. The vibration process of jointed beams includes free-play and impact stages. A method for the dynamic analysis of jointed beams with clearance is proposed based on mode superposition and instantaneous static deformation. Transfer matrix, which expresses the relationship of the responses before and after the impact of jointed beams, is derived to calculate the response of the jointed beams after a critical position. The dynamic responses of jointed beams are then simulated. The effects of various parameters on the displacement and velocity of beams are investigated.

  4. Visualization of Tear Clearance Using Anterior Segment Optical Coherence Tomography and Polymethylmethacrylate Particles.

    PubMed

    Zheng, Xiaodong; Yamaguchi, Masahiko; Kamao, Tomoyuki; Sakane, Yuri; Goto, Tomoko; Shiraishi, Atsushi; Ohashi, Yuichi

    2016-11-01

    We previously reported 2 new methods, anterior segment optical coherence tomography (AS-OCT) and polymethylmethacrylate particles suspended in fluorescein solution (PPF), for the evaluation of tear clearance and rapid tear flow after blinking (tear Krehbiel flow). Here, we investigated age-related OCT tear clearance and tear film thickness (TFT) and the potential correlation of OCT tear clearance and PPF velocity indicative of tear Krehbiel flow. Normal subjects separated into young and older groups received 5 μL of saline solution into the lower conjunctival sac, and an image of the central lower eyelid tear meniscus was captured by AS-OCT immediately and 30 seconds after natural blinking. Tear meniscus height (TMH) and tear meniscus area (TMA) were measured, and their percentage decrease was defined as OCT clearance rate. A Spectralis OCT Anterior Segment Module captured the central corneal tear film layer for TFT measurements. OCT clearance rates were significantly higher in young versus older subjects (P = 0.0002). When all subjects were analyzed, age was significantly and negatively correlated with TMH clearance rate (r = -0.4928, P = 0.0003) and TMA clearance rate (r = -0.4596, P = 0.0008). TFT values were significantly and negatively correlated with age (r = -0.6662, P < 0.0001). A second experiment examined tear Krehbiel flow by measuring PPF velocity in frontal and medial gaze positions. The medial gaze position showed significantly increased PPF velocity compared with the frontal gaze position (P = 0.006). Significant and positive correlations were found between OCT clearance rates and PPF velocity (TMH rate: r = 0.2926, P = 0.0392; TMA rate: r = 0.3274, P = 0.0205). AS-OCT and PPF might be novel techniques for quantitative evaluation of tear clearance and Krehbiel flow.

  5. Augmented renal clearance in critically ill patients: incidence, associated factors and effects on vancomycin treatment

    PubMed Central

    Campassi, María Luz; Gonzalez, María Cecilia; Masevicius, Fabio Daniel; Vazquez, Alejandro Risso; Moseinco, Miriam; Navarro, Noelia Cintia; Previgliano, Luciana; Rubatto, Nahuel Paolo; Benites, Martín Hernán; Estenssoro, Elisa; Dubin, Arnaldo

    2014-01-01

    Objective An augmented renal clearance has been described in some groups of critically ill patients, and it might induce sub-optimal concentrations of drugs eliminated by glomerular filtration, mainly antibiotics. Studies on its occurrence and determinants are lacking. Our goals were to determine the incidence and associated factors of augmented renal clearance and the effects on vancomycin concentrations and dosing in a series of intensive care unit patients. Methods We prospectively studied 363 patients admitted during 1 year to a clinical-surgical intensive care unit. Patients with serum creatinine >1.3mg/dL were excluded. Creatinine clearance was calculated from a 24-hour urine collection. Patients were grouped according to the presence of augmented renal clearance (creatinine clearance >120mL/min/1.73m2), and possible risk factors were analyzed with bivariate and logistic regression analysis. In patients treated with vancomycin, dosage and plasma concentrations were registered. Results Augmented renal clearance was present in 103 patients (28%); they were younger (48±15 versus 65±17 years, p<0.0001), had more frequent obstetric (16 versus 7%, p=0.0006) and trauma admissions (10 versus 3%, p=0.016) and fewer comorbidities. The only independent determinants for the development of augmented renal clearance were age (OR 0.95; p<0.0001; 95%CI 0.93-0.96) and absence of diabetes (OR 0.34; p=0.03; 95%CI 0.12-0.92). Twelve of the 46 patients who received vancomycin had augmented renal clearance and despite higher doses, had lower concentrations. Conclusions In this cohort of critically ill patients, augmented renal clearance was a common finding. Age and absence of diabetes were the only independent determinants. Therefore, younger and previously healthy patients might require larger vancomycin dosing. PMID:24770684

  6. Insulin clearance is different in men and women

    PubMed Central

    Jensen, Michael D.; Nielsen, Soren; Gupta, Nidhi; Basu, Rita; Rizza, Robert

    2011-01-01

    Objective Insulin is often infused based upon total body weight (TBW) or fat free mass (FFM)for glucose clamp protocols. We observed greater insulin concentrations in men than women using this approach and examined whether splanchnic insulin extraction accounts for the differences. Materials/Methods Whole body insulin clearance was measured during a pancreatic clamp study (somatostatin to inhibit islet hormone secretion) including 13 adults (6 men) and whole body insulin clearance was measured during a euglycemic, hyperinsulinemic clamp study including 27 adults (13 men). Femoral artery and hepatic vein blood samples were collected to measure splanchnic insulin balance. For the pancreatic clamp study insulin was infused at rates of 0.5, 1.0, and 2.0 mU•kgTBW−1•min−1 and for the euglycemic, hyperinsulinemic clamp study insulin was infused at 2.5 mU•kg FFM−1•min−1. Results Significantly greater arterial insulin concentrations were found in men than women. Splanchnic plasma flow was similar in men and women in both protocols. Splanchnic insulin extraction and the fraction of infused insulin removed by splanchnic bed were significantly greater in men than in women. However, whole body insulin clearance was greater in women than men. Conclusions Infusing insulin per body weight or FFM results in higher plasma insulin concentrations in men than women. Splanchnic insulin extraction is greater in men, indicating greater peripheral insulin clearance in women accounts for the sex differences we observed. This finding has implications for insulin clamp study design and raises the question of which tissues take up more insulin in women. PMID:22000585

  7. Effects of airborne pollutants on mucociliary clearance.

    PubMed Central

    Wolff, R K

    1986-01-01

    The mucociliary clearance system is a first line of defense against inhaled agents, and so its compromise can adversely affect health. The purpose of this paper is to provide a review of data on the effect of in vivo air pollutant exposures on the clearance of test particles from airways. Data from both animals and humans are compared whenever possible, so that estimates of human health effects may be made. Mechanisms of action are also discussed, presenting the view that for low level exposures, changes in secretions are probably responsible for most observed changes in clearance. The pollutants pertinent to this review are those that are common in the environment and most likely to have impacts on large numbers of people: sulfur oxides, sulfuric acid mist, O3, NO2, particulates, diesel exhaust, and cigarette smoke. Images FIGURE 1. FIGURE 2. a FIGURE 2. b FIGURE 4. PMID:3519203

  8. Effects of airborne pollutants on mucociliary clearance

    SciTech Connect

    Wolff, R.K.

    1986-04-01

    The mucociliary clearance system is a first line of defense against inhaled agents, and so its compromise can adversely affect health. The purpose of this paper is to provide a review of data on the effect of in vivo air pollutant exposures on the clearance of test particles from airways. Data from both animals and humans are compared whenever possible, so that estimates of human health effects may be made. Mechanisms of action are also discussed, presenting the view that for low level exposures, changes in secretions are probably responsible for most observed changes in clearance. The pollutants pertinent to this review are those that are common in the environment and most likely to have impacts on large numbers of people: sulfur oxides, sulfuric acid mist, O/sub 3/, NO/sub 2/, particulates, diesel exhaust, and cigarette smoke.149 references.

  9. 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

  10. A comparison of methods for the estimation of the proportion of microbial nitrogen in duodenal digesta, and of correction for microbial contamination in nylon bags incubated in the rumen of sheep.

    PubMed

    Kennedy, P M; Hazlewood, G P; Milligan, L P

    1984-09-01

    Four sheep, each fitted with cannulas in the rumen and proximal duodenum, were given two diets (1390 g dry matter (DM)/d) consisting of lucerne (Medicago sativa) pellets (24.2 g nitrogen/kg DM) plus pelleted reed canary grass (Phalaris arundinacea; 14.1 g N/kg DM) or chopped hay (11.8 g N/kg DM) at intervals of 2 h. Flow of duodenal digesta measured by reference to the markers 51Cr-EDTA and 103Ru-phenanthroline indicated a net gain of 5.8-7.5 g non-ammonia-N (NAN) between mouth and duodenum. The proportion of microbial N in duodenal digesta N was estimated using 15N and 35S incorporation into bacteria and digesta. Two methods of analysis for 35S content, the Bird & Fountain (1970; B&F method) and the Mathers & Miller (1980; M&M method), were used. (15NH4)2SO4 and Na2(35)SO4 were infused into the rumen for 3.5 d before and 4.0 d during sampling. A bacterial fraction was prepared from the fluid phases of sampled duodenal digesta and rumen contents by differential centrifugation. In addition, samples of ground canary grass and of lucerne were incubated in nylon bags in the rumen for 3-48 h during the infusion. Each of the 35S analytical methods yielded similar values of 35S content of isolated rumen or duodenal bacteria, but there was more (P less than 0.05) incorporation of 15N into rumen than into duodenal bacteria. Relative to values obtained using the M&M method and 15N incorporation, the B&F method for S analysis yielded higher (P less than 0.05) estimates of microbial content of duodenal digesta from sheep given chopped reed canary grass. 35S activity associated with washed nylon-bag residues increased rapidly with time-period of incubation and was substantially greater (P less than 0.05) when analysed by the B&F method compared with the M&M method. The 35S content (/g DM) of adherent bacteria removed from nylon-bag residues by homogenization in a second experiment varied from 0.65 to 1.88 that of free-living bacteria isolated from rumen fluid by differential

  11. Predicting Clearance Mechanism in Drug Discovery: Extended Clearance Classification System (ECCS).

    PubMed

    Varma, Manthena V; Steyn, Stefanus J; Allerton, Charlotte; El-Kattan, Ayman F

    2015-12-01

    Early prediction of clearance mechanisms allows for the rapid progression of drug discovery and development programs, and facilitates risk assessment of the pharmacokinetic variability associated with drug interactions and pharmacogenomics. Here we propose a scientific framework--Extended Clearance Classification System (ECCS)--which can be used to predict the predominant clearance mechanism (rate-determining process) based on physicochemical properties and passive membrane permeability. Compounds are classified as: Class 1A--metabolism as primary systemic clearance mechanism (high permeability acids/zwitterions with molecular weight (MW) ≤400 Da), Class 1B--transporter-mediated hepatic uptake as primary systemic clearance mechanism (high permeability acids/zwitterions with MW >400 Da), Class 2--metabolism as primary clearance mechanism (high permeability bases/neutrals), Class 3A--renal clearance (low permeability acids/zwitterions with MW ≤400 Da), Class 3B--transporter mediated hepatic uptake or renal clearance (low permeability acids/zwitterions with MW >400 Da), and Class 4--renal clearance (low permeability bases/neutrals). The performance of the ECCS framework was validated using 307 compounds with single clearance mechanism contributing to ≥70% of systemic clearance. The apparent permeability across clonal cell line of Madin - Darby canine kidney cells, selected for low endogenous efflux transporter expression, with a cut-off of 5 × 10(-6) cm/s was used for permeability classification, and the ionization (at pH7) was assigned based on calculated pKa. The proposed scheme correctly predicted the rate-determining clearance mechanism to be either metabolism, hepatic uptake or renal for ~92% of total compounds. We discuss the general characteristics of each ECCS class, as well as compare and contrast the framework with the biopharmaceutics classification system (BCS) and the biopharmaceutics drug disposition classification system (BDDCS

  12. 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.

  13. Mucociliary clearance from the calf lung.

    PubMed Central

    Jones, C D

    1983-01-01

    Mucociliary clearance rate constants for ten calves were obtained using Technetium 99m-sulphur colloid complex. The mean rate constant measured at the lung for all calves was 0.012 (+/- 0.009) min-1 (half-life 58 minutes). The clearance rate constants obtained from measurements made at the larynx were higher (0.02 +/- 0.007 min-1), although not significantly higher, than those determined from measurements taken at the lung. The constants can be used to predict the particle burden on the lungs of calves kept under husbandry systems of varying air hygiene. Images Fig. 1. PMID:6640409

  14. 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.

  15. Acute effect of inhaled bradykinin on tracheobronchial clearance in normal humans.

    PubMed Central

    Polosa, R; Hasani, A; Pavia, D; Agnew, J E; Lai, C K; Clarke, S W; Holgate, S T

    1992-01-01

    BACKGROUND: Bradykinin, a nonapeptide that contributes as a mediator to the pathogenesis of asthma, may affect lung mucociliary clearance, as it has been shown to be a potent secretagogue in canine airways and in human nasal mucosa in vivo. To evaluate this possibility the effect of inhaled bradykinin on mucociliary clearance has been studied in 10 healthy volunteers. METHODS: Subjects attended the laboratory on two occasions to take part in tracheobronchial clearance studies using a non-invasive radioisotopic technique. Inhalation of radioaerosol was followed 30 minutes later by inhalation of either bradykinin (8 mg/ml) or vehicle placebo in a randomised, double blind fashion. After each inhalation the number of coughs was recorded. Whole lung radioactivity was measured every half hour for six hours with two collimated scintillation counters, and a tracheobronchial clearance curve was plotted for each subject on each occasion. RESULTS: Mucociliary clearance, expressed as the area under the tracheobronchial radioaerosol retention curve calculated for the first six hours (AUC0-6h), was greater in nine out of 10 subjects after inhalation of bradykinin than after placebo. The median values (range) for AUC0-6h were significantly reduced from 126% (78-232%)/h with placebo to 87% (51-133%)/h with bradykinin. CONCLUSION: It is concluded that acute exposure to inhaled bradykinin accelerates tracheobronchial clearance in normal human airways. PMID:1465754

  16. Effects of Bearing Clearance on Turbopump Stability

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Effects of bearing clearances, or "dead bands," on bearing loads and rotor stability in turbopumps examined in a 194-page report. Relatively simple mathematical force model for analyzing effects highlighted. Report shows nonlinear characteristics resulting from bearing dead bands have significant effect on dynamics of turbomachinery and not ignored as in the past.

  17. 32 CFR 154.16 - Security clearance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 1 2010-07-01 2010-07-01 false Security clearance. 154.16 Section 154.16 National Defense Department of Defense OFFICE OF THE SECRETARY OF DEFENSE SECURITY DEPARTMENT OF DEFENSE PERSONNEL SECURITY PROGRAM REGULATION Personnel Security Investigative Requirements § 154.16...

  18. 32 CFR 154.16 - Security clearance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 1 2014-07-01 2014-07-01 false Security clearance. 154.16 Section 154.16 National Defense Department of Defense OFFICE OF THE SECRETARY OF DEFENSE SECURITY DEPARTMENT OF DEFENSE PERSONNEL SECURITY PROGRAM REGULATION Personnel Security Investigative Requirements § 154.16...

  19. 32 CFR 154.16 - Security clearance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 1 2012-07-01 2012-07-01 false Security clearance. 154.16 Section 154.16 National Defense Department of Defense OFFICE OF THE SECRETARY OF DEFENSE SECURITY DEPARTMENT OF DEFENSE PERSONNEL SECURITY PROGRAM REGULATION Personnel Security Investigative Requirements § 154.16...

  20. 32 CFR 154.16 - Security clearance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 1 2011-07-01 2011-07-01 false Security clearance. 154.16 Section 154.16 National Defense Department of Defense OFFICE OF THE SECRETARY OF DEFENSE SECURITY DEPARTMENT OF DEFENSE PERSONNEL SECURITY PROGRAM REGULATION Personnel Security Investigative Requirements § 154.16...

  1. 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 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and...

  2. 30 CFR 57.11010 - Stairstep clearance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Stairstep clearance. 57.11010 Section 57.11010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... steps shall be a minimum of seven feet, or suitable warning signs or similar devices shall be...

  3. 30 CFR 57.11010 - Stairstep clearance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Stairstep clearance. 57.11010 Section 57.11010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... steps shall be a minimum of seven feet, or suitable warning signs or similar devices shall be...

  4. Clearance of seborrhoeic keratoses with topical dobesilate

    PubMed Central

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

    2012-01-01

    A patient with two seborrhoeic keratoses in the face received a single daily application of dobesilate cream during 6 months. Dobesilate achieved complete clearance of the seborrhoeic keratosis lesions with good cosmoses, suggesting that this compound is a safe and efficient candidate in the treatment of seborrhoeic keratoses. PMID:22729328

  5. Carbamazepine clearance and seizure stability during pregnancy.

    PubMed

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

    2014-04-01

    The aims of this study were to characterize the alterations in total and free carbamazepine (CBZ) and in total and free carbamazepine-epoxide (CBZ-EPO) clearances during pregnancy, to calculate the change in free fractions of CBZ and CBZ-EPO during pregnancy, and to determine whether seizure worsening is associated with a low ratio to nonpregnant baseline concentration of total or free CBZ or CBZ-EPO. Women on CBZ were enrolled before conception or during pregnancy in this prospective, observational study. Concomitant medications and seizure frequency were recorded. Serum total and free CBZ and CBZ-EPO were collected at each visit. Changes in the clearance of all four compounds and free fractions of CBZ and CBZ-EPO were compared with nonpregnant baseline. During pregnancy, the ratios to baseline concentrations of total and free CBZ and CBZ-EPO were compared for months with and without increased seizure frequency. Total and free CBZ and CBZ-EPO clearances were calculated in 15 pregnancies in 12 women. Clearances did not change for any of these compounds during pregnancy. The free fraction of CBZ increased from 0.23 at baseline to a maximum of 0.32 in the third trimester (p=0.008). In the six women on CBZ monotherapy with adequate seizure diaries and blood sampling, seizure worsening did not correspond to a ratio to baseline concentration of less than 0.65 for total or free CBZ or CBZ-EPO. In conclusion, total and free CBZ and CBZ-EPO clearances did not change substantially during pregnancy, and seizure frequency worsening was not associated with decreased concentrations of total or free CBZ; therefore, therapeutic drug monitoring may not be necessary for all women on CBZ during pregnancy. Further studies with larger sample sizes are needed before definitive recommendations can be made. Carbamazepine monotherapy may be a relatively safe and cost effective treatment option for women with focal epilepsy syndromes during pregnancy.

  6. 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....

  7. 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.

  8. 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....

  9. 14 CFR 29.661 - Rotor blade clearance.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Rotors § 29.661 Rotor blade clearance. There must be enough clearance between the rotor blades and other parts of the structure to... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Rotor blade clearance. 29.661 Section...

  10. 14 CFR 27.661 - Rotor blade clearance.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Rotors § 27.661 Rotor blade clearance. There must be enough clearance between the rotor blades and other parts of the structure to... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Rotor blade clearance. 27.661 Section...

  11. 14 CFR 29.661 - Rotor blade clearance.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Rotors § 29.661 Rotor blade clearance. There must be enough clearance between the rotor blades and other parts of the structure to... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Rotor blade clearance. 29.661 Section...

  12. 14 CFR 29.661 - Rotor blade clearance.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Rotors § 29.661 Rotor blade clearance. There must be enough clearance between the rotor blades and other parts of the structure to... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Rotor blade clearance. 29.661 Section...

  13. 14 CFR 27.661 - Rotor blade clearance.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Rotors § 27.661 Rotor blade clearance. There must be enough clearance between the rotor blades and other parts of the structure to... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Rotor blade clearance. 27.661 Section...

  14. 14 CFR 27.661 - Rotor blade clearance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

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

  15. 14 CFR 27.661 - Rotor blade clearance.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Rotors § 27.661 Rotor blade clearance. There must be enough clearance between the rotor blades and other parts of the structure to... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Rotor blade clearance. 27.661 Section...

  16. 14 CFR 29.661 - Rotor blade clearance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

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

  17. 14 CFR 29.661 - Rotor blade clearance.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Rotors § 29.661 Rotor blade clearance. There must be enough clearance between the rotor blades and other parts of the structure to... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Rotor blade clearance. 29.661 Section...

  18. 14 CFR 27.661 - Rotor blade clearance.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Rotors § 27.661 Rotor blade clearance. There must be enough clearance between the rotor blades and other parts of the structure to... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Rotor blade clearance. 27.661 Section...

  19. 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... Clauses 2452.237-75 Clearance of contractor personnel. As prescribed in 2437.110(e), insert the following clause in solicitations and contracts. Clearance of Contractor Personnel (OCT 1999) (a) General....

  20. 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...

  1. 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...

  2. 30 CFR 56.19104 - Clearance at shaft stations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Clearance at shaft stations. 56.19104 Section 56.19104 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Hoisting Shafts § 56.19104 Clearance at shaft stations. Suitable clearance at shaft stations shall...

  3. 14 CFR 375.24 - Entry and clearance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Entry and clearance. 375.24 Section 375.24 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) SPECIAL... Entry and clearance. All U.S. entry and clearance requirements for aircraft, passengers, crews,...

  4. 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...

  5. 30 CFR 57.19104 - Clearance at shaft stations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Clearance at shaft stations. 57.19104 Section 57.19104 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Hoisting Shafts § 57.19104 Clearance at shaft stations. Suitable clearance at shaft stations shall...

  6. 75 FR 70341 - Agency Information Collection Activities: Emergency Clearance Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-17

    ... ADMINISTRATION Agency Information Collection Activities: Emergency Clearance Request The Social Security Administration (SSA) publishes a list of information collection packages requiring clearance by the Office of... Desk Officer and SSA Reports Clearance Officer to the following addresses or fax numbers. (OMB),...

  7. 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... clearance requirements. All other provisions of this part relating to entry and clearance of aircraft...

  8. 30 CFR 56.9103 - Clearance on adjacent tracks.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Clearance on adjacent tracks. 56.9103 Section..., Hauling, and Dumping Traffic Safety § 56.9103 Clearance on adjacent tracks. Railcars shall not be left on side tracks unless clearance is provided for traffic on adjacent tracks....

  9. 76 FR 17615 - Highway-Rail Grade Crossing; Safe Clearance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-30

    ... 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 Clearance... Crossing; Safe Clearance Notice of Proposed Rulemaking, which was published on January 28, 2011 (76 FR...

  10. 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... and Procedures in National Labor Relations Board Proceedings § 706.13 Clearance of counsel. It is recognized that clearance of counsel for the parties is sometimes desirable for proper preparation of a...

  11. 8 CFR 1280.6 - Bond to obtain clearance; form.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Bond to obtain clearance; form. 1280.6... IMMIGRATION REGULATIONS IMPOSITION AND COLLECTION OF FINES § 1280.6 Bond to obtain clearance; form. A bond to obtain clearance of a vessel or aircraft under section 231, 237, 239, 243, 251, 253, 254, 255, 256,...

  12. 10 CFR 95.17 - Processing facility clearance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Processing facility clearance. 95.17 Section 95.17 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) FACILITY SECURITY CLEARANCE AND SAFEGUARDING OF NATIONAL SECURITY INFORMATION AND RESTRICTED DATA Physical Security § 95.17 Processing facility clearance....

  13. 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....

  14. 19 CFR 122.157 - Documents required for clearance.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Documents required for clearance. 122.157 Section 122.157 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT... clearance. As a condition precedent to clearance, the aircraft commander shall present to Customs: (a)...

  15. 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 Administration (SSA) publishes a list of information collection packages requiring clearance by the Office of... Desk Officer and SSA Reports Clearance Officer to the following addresses or fax numbers. (OMB),...

  16. 8 CFR 280.6 - Bond to obtain clearance; form.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Bond to obtain clearance; form. 280.6 Section 280.6 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS IMPOSITION AND COLLECTION OF FINES § 280.6 Bond to obtain clearance; form. A bond to obtain clearance of a...

  17. 30 CFR 57.9103 - Clearance on adjacent tracks.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Clearance on adjacent tracks. 57.9103 Section..., Hauling, and Dumping Traffic Safety § 57.9103 Clearance on adjacent tracks. Railcars shall not be left on side tracks unless clearance is provided for traffic on adjacent tracks....

  18. 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...

  19. 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...

  20. 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...

  1. 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 Section 205.20 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL... Agreement § 205.20 What is a clearance pattern? States use clearance patterns to project when funds are...

  2. 30 CFR 56.9306 - 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. 56... Loading and Dumping Sites § 56.9306 Warning devices for restricted clearances. Where restricted clearance creates a hazard to persons on mobile equipment, warning devices shall be installed in advance of...

  3. 30 CFR 56.9306 - 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. 56... Loading and Dumping Sites § 56.9306 Warning devices for restricted clearances. Where restricted clearance creates a hazard to persons on mobile equipment, warning devices shall be installed in advance of...

  4. 30 CFR 56.9306 - 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. 56... Loading and Dumping Sites § 56.9306 Warning devices for restricted clearances. Where restricted clearance creates a hazard to persons on mobile equipment, warning devices shall be installed in advance of...

  5. 30 CFR 56.9306 - 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. 56... Loading and Dumping Sites § 56.9306 Warning devices for restricted clearances. Where restricted clearance creates a hazard to persons on mobile equipment, warning devices shall be installed in advance of...

  6. 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....

  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, 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....

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

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 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. If the plant clearance function has not been formally delegated to another Federal agency,...

  10. 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... MANAGEMENT GOVERNMENT PROPERTY Reporting, Reutilization, and Disposal 945.670-1 Plant clearance function. If the plant clearance function has not been formally delegated to another Federal agency,...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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... responsible for requesting clearance of its counsel well in advance so that clearance requirements will...

  17. 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.

  18. Effect of ultrafiltration on peritoneal dialysis drug clearances.

    PubMed

    Lau, A H; Chow-Tung, E; Assadi, F K; Fornell, L; John, E

    1985-01-01

    To determine the effect of dialysate osmolarity on peritoneal dialysis drug transfer, peritoneal dialysis clearances of theophylline, phenobarbital, and tobramycin were determined in 10 rabbits using dialysate containing 1.5 and 4.25% glucose. Urea and creatinine clearances were also obtained for comparison. Under similar dialysis conditions, the peritoneal clearances of the three drugs remained unchanged for the two types of dialysate. In contrast, the peritoneal clearances of urea and creatinine were significantly higher with the use of 4.25% glucose dialysate (p less than 0.001). Thus, peritoneal dialysis clearances of theophylline, phenobarbital and tobramycin are not significantly affected by hypertonicity-induced ultrafiltration during acute peritoneal dialysis.

  19. 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.

  20. 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

  1. Activating the 42d Clearance Company

    DTIC Science & Technology

    2011-12-01

    System– Enhanced. ■ Establishing supply and maintenance accounts. ■ Procuring the unit guidon . Other documents created to expedite and track the...SUBTITLE Activating the 42d Clearance Company 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) 5d. PROJECT NUMBER 5e. TASK...NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) Army Engineer School,Engineer Professional Bulletin,464 MANSCEN

  2. Army Delivers Route Clearance Vehicle Capabilities

    DTIC Science & Technology

    2010-08-01

    the Husky Vehicle-Mount- ed Mine-Detection (VMMD) System, the Buffalo® Mine- Protected Clearance Vehicle (MPCV), the Panther Medium Mine-Protected...cord (POR) RCVs—the Husky, the Buf- falo, and the Panther . POR-configured Huskys, Buffalos, and Panthers have already been fielded in-theater—albeit...IED vehicle equipped with a distinctive hydraulic arm that inter- rogates suspected explosive hazards and clears them when necessary. The Panther

  3. Reduced methadone clearance during aromatase inhibition.

    PubMed

    Lu, Wenjie Jessie; Thong, Nancy; Flockhart, David A

    2012-08-01

    Methadone is increasingly used in pain management and is a cornerstone in the treatment of opiate withdrawal. It is subject to highly variable clearance among patients. The complete metabolic disposition of methadone is likely to involve a number of enzymes, including specifically CYP2B6. Previous studies in vitro suggest that metabolism by aromatase may also contribute. Single-dose methadone pharmacokinetics (2 mg, intravenous) were studied in 15 healthy postmenopausal women in the presence and absence of a potent aromatase inhibitor, letrozole. A sequential design was used, involving a control period followed by treatment with letrozole (2.5 mg/d, 11 days), in which each subject served as her own control. On average, letrozole treatment reduced methadone systemic clearance by 22% (P = 0.001), increased methadone AUC by 23% (P = 0.007), and increased elimination half-life by 21% (P = 0.042). The plasma parent-to-metabolite ratio also increased (P = 0.009), and there was a linear relationship (R2 = 0.74) between change in this plasma ratio and change in methadone AUC0-∞. In contrast, there was no such association with change in apparent urinary methadone clearance. Letrozole did not change methadone distribution half-life or its volume of distribution. Overall, these data demonstrate a significant decrease in methadone clearance during coadministration of letrozole, consistent with decreased metabolism brought about by aromatase inhibition. An involvement of aromatase in the disposition of methadone may help explain the difficulty in methadone dosing and suggests a broader role for this catalyst of endogenous steroid metabolism in xenobiotic drug disposition.

  4. Application of chromatic confocal displacement sensor in measurement of tip clearance

    NASA Astrophysics Data System (ADS)

    Bi, Chao; Li, Di; Fang, Jianguo; Zhang, Bin

    2016-10-01

    In the field of aeronautics, the tip clearance of rotor exerts a crucial influence on the performance of the aero engine. As defined as the radial distance between the top of the blade and the inner wall of the casing, the tip clearance of too large or small size will adversely affect the normal running of the engine. In order to realize accurate measurement of the tip clearance in a simple way, a non-contact measuring method by the chromatic confocal displacement sensor is proposed in the paper. The sensor possesses the advantages such as small volume, good signal-to-noise ratio, high accuracy and response frequency etc., which make it be widely used in engineering and industry. For testing the performance and potential application of the sensor, a simulation testing platform is established. In the platform, a simulation blisk is installed on the air bearing spindle and a chromatic confocal displacement sensor is fixed on the platform to measure the displacement variation of the blade tip, which can be used to characterize the variation of the tip clearance. In the simulation experiments, both of single and continuous measurement of the tip clearance of the 36 blades on the blisk is executed. As the results of experiments show, the chromatic confocal displacement sensor can meet the requirements of measuring task, in which both of high measuring efficiency and accuracy could be achieved. Therefore, the measuring method proposed in the paper can be utilized in the actual assembling sites of the aero engine.

  5. Human amyloid-beta synthesis and clearance rates as measured in cerebrospinal fluid in vivo.

    PubMed

    Bateman, Randall J; Munsell, Ling Y; Morris, John C; Swarm, Robert; Yarasheski, Kevin E; Holtzman, David M

    2006-07-01

    Certain disease states are characterized by disturbances in production, accumulation or clearance of protein. In Alzheimer disease, accumulation of amyloid-beta (Abeta) in the brain and disease-causing mutations in amyloid precursor protein or in enzymes that produce Abeta indicate dysregulation of production or clearance of Abeta. Whether dysregulation of Abeta synthesis or clearance causes the most common form of Alzheimer disease (sporadic, >99% of cases), however, is not known. Here, we describe a method to determine the production and clearance rates of proteins within the human central nervous system (CNS). We report the first measurements of the fractional production and clearance rates of Abeta in vivo in the human CNS to be 7.6% per hour and 8.3% per hour, respectively. This method may be used to search for novel biomarkers of disease, to assess underlying differences in protein metabolism that contribute to disease and to evaluate treatments in terms of their pharmacodynamic effects on proposed disease-causing pathways.

  6. 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.

  7. RGS21, A Regulator of Taste and Mucociliary Clearance?

    PubMed Central

    Kimple, Adam J.; Garland, Alaina L.; Cohen, Staci P.; Setola, Vincent; Willard, Francis S.; Zielinski, Thomas; Lowery, Robert G.; Tarran, Robert; Siderovski, David P.

    2014-01-01

    Objectives/Hypothesis: Motile cilia of airway epithelial cells help to expel harmful inhaled material. Activation of bitterant-responsive G protein-coupled receptors (GPCRs) is believed to potentiate cilia beat frequency and mucociliary clearance. In this study, we investigated whether regulator of G protein signaling-21 (RGS21) has the potential to modulate signaling pathways connected to airway mucociliary clearance, given that RGS proteins modulate GPCR signaling by acting as GTPase-accelerating proteins (GAPs) for the Gα subunits of heterotrimeric G proteins. Study Design: This is a pilot investigation to determine if RGS21, a potential tastant specific RGS gene, is expressed in sinonasal mucosa, and to determine its specific Gα substrate using in vitro biochemical assays with purified proteins. Methods: Rgs21 expression in sinonasal mucosa was determined using quantitative, real-time PCR and a transgenic mouse expressing RFP from the Rgs21 promoter. Rgs21 was cloned, over-expressed, and purified using multistep protein chromatography. Biochemical and biophysical assays were used to determine if RGS21 could bind and accelerate the hydrolysis of GTP on heterotrimeric Gα subunits. Results: Rgs21 was expressed in sinonasal mucosa and lingual epithelium. Purified recombinant protein directly bound and accelerated GTP hydrolysis on Gα subunits. Conclusions: Rgs21 is expressed in sinonasal mucosa, is amenable to purification as a recombinant protein, and can bind to Gαi/o/q subunits. Furthermore, RGS21 can accelerate the hydrolysis rate of GTP on Gαi subunits. This provides evidence that RGS21 may be a negative regulator of bitterant responses. Future studies will be needed to determine the physiological role of this protein in mucociliary clearance. PMID:23908053

  8. 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.

  9. 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

  10. 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

  11. Analytical and experiment study of clearance and bearing-bypass load effects in composite bolted joints

    SciTech Connect

    Naik, R.V.A.

    1986-01-01

    A combined analytical and experimental study is conducted to determine the effects of clearance and bearing-bypass loading for mechanically fastened joints in composites. A simple method of analysis is developed to account for the nonlinear effects of bolt-hole clearance. The nonlinear load-contact variations for clearance-fit fasteners are also measured using specially instrumented fastener. For a quasi-isotropic graphite/epoxy laminate, results show that the contact arc as well as the peak stresses around the hole and their locations are strongly influenced by the clearance. After a slight initial nonlinearity, the peak stresses vary linearly with applied load. The typical clearance levels are shown to have only a minor influence on the overall joint stiffness. Quasi-isotropic graphite/epoxy laminates (T300/5208) were tested under combined bearing and bypass loading to study failure modes and strengths. Radiographs were made after damage onset and after ultimate load to examine the failure criteria to analyze the test data. The near the bolt-hole are calculated for each test condition, and then used with appropriate failure criteria to analyze the test data. The tension data show a linear interaction for combined bearing and bypass loading with damage developing the net-tension mode and growing to failure in the same mode. Failure modes are more complex in compression.

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

    NASA Astrophysics Data System (ADS)

    Wang, J.; Shen, H. P.; Y Ye, X.; Hu, J. N.; Feng, Y. N.

    2013-12-01

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

  13. 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

  14. Influence of ingested ethanol on Photofrin clearance in mice

    NASA Astrophysics Data System (ADS)

    Montague, Donna; Fink, Louis; Stone, Angie; Flock, Stephen T.

    1993-06-01

    A series of experiments have been undertaken to ascertain the influence of dietary additives on the clearance of Photofrin. Post-treatment cutaneous photosensitivity continues to be a significant side effect of photodynamic therapy (PDT) in humans. Cutaneous photosensitivity in humans is evidenced by erythema and edema in exposed areas. Murine models were chosen to investigate the differences in cutaneous photosensitivity as measured by footpad thickness in the presence or absence of dietary additives. Additionally, radiation induced fibrosarcoma (RIF) cells were implanted into the subcutaneous space on the dorsal aspect of the foot. In this case, the effect of PDT on tumor growth kinetics was assumed to be proportional to Photofrin concentration. Photofrin concentrations in tumors were measured by HPLC. Serum levels for dietary additives were obtained where analytical methods were available. Ingested ethanol increased the clearance rate of Photofrin as demonstrated by measurements of Photofrin tumor concentration and by failure of RIF tumor to respond to PDT in groups treated with ethanol compared to controls.

  15. 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

  16. 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

  17. Tip Clearance Control Using Plasma Actuators

    DTIC Science & Technology

    2007-03-01

    Clearance Control Using Plasma Actuators 4 posed by Denton (1993). A number of investigators have used partial shrouds, or " winglet " designs to...main molded blade with a span of 3.42 in., a removable molded blade segment with a span of 0.1875 in., and removable blade tip winglets made of glass...segment and the main blade to vary the distance between the blade end and the front wall of the cascade section. The winglets were machined using a

  18. Statistical Tolerance and Clearance Analysis for Assembly

    NASA Technical Reports Server (NTRS)

    Lee, S.; Yi, C.

    1996-01-01

    Tolerance is inevitable because manufacturing exactly equal parts is known to be impossible. Furthermore, the specification of tolerances is an integral part of product design since tolerances directly affect the assemblability, functionality, manufacturability, and cost effectiveness of a product. In this paper, we present statistical tolerance and clearance analysis for the assembly. Our proposed work is expected to make the following contributions: (i) to help the designers to evaluate products for assemblability, (ii) to provide a new perspective to tolerance problems, and (iii) to provide a tolerance analysis tool which can be incorporated into a CAD or solid modeling system.

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

    PubMed Central

    Elgrabli, Dan; Floriani, Magali; Abella-Gallart, Steve; Meunier, Laurent; Gamez, Christelle; Delalain, Patrice; Rogerieux, Françoise; Boczkowski, Jorge; Lacroix, Ghislaine

    2008-01-01

    Background Constituted only by carbon atoms, CNT are hydrophobic and hardly detectable in biological tissues. These properties make biokinetics and toxicology studies more complex. Methods We propose here a method to investigate the biopersistence of CNT in organism, based on detection of nickel, a metal present in the MWCNT we investigated. Results and conclusion Our results in rats that received MWCNT by intratracheal instillation, reveal that MWCNT can be eliminated and do not significantly cross the pulmonary barrier but are still present in lungs 6 months after a unique instillation. MWCNT structure was also showed to be chemically modified and cleaved in the lung. These results provide the first data of CNT biopersistence and clearance at 6 months after respiratory administration. PMID:19068117

  20. 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.

  1. Numerical investigation of hub clearance flow in a Kaplan turbine

    NASA Astrophysics Data System (ADS)

    Wu, H.; Feng, J. J.; Wu, G. K.; Luo, X. Q.

    2012-11-01

    In this paper, the flow field considering the hub clearance flow in a Kaplan turbine has been investigated through using the commercial CFD code ANSYS CFX based on high-quality structured grids generated by ANSYS ICEM CFD. The turbulence is simulated by k-ω based shear stress transport (SST) turbulence model together with automatic near wall treatments. Four kinds of simulations have been conducted for the runner geometry without hub clearance, with only the hub front clearance, with only the rear hub clearance, and with both front and rear clearance. The analysis of the obtained results is focused on the flow structure of the hub clearance flow, the effect on the turbine performance including hydraulic efficiency and cavitation performance, which can improve the understanding on the flow field in a Kaplan turbine.

  2. Repair of sublethal radiation injury after multiple small doses in mouse kidney: an estimate of flexure dose

    SciTech Connect

    Stewart, F.A.; Oussoren, Y.; Luts, A.; Begg, A.C.; Dewit, L.; Lebesque, J.; Bartelink, H.

    1987-05-01

    Functional kidney damage in mice was measured after a series of fractionated X-irradiations. Doses per fraction of 0.75-12.5 Gy were given as 2, 5, 10, 30, 40, 60, or 80 equal doses in a total treatment time of 4 weeks. Renal function (measured by clearance of /sup 51/CrEDTA or hematocrit levels) deteriorated progressively, in a dose related manner, from 20 to 46 weeks after the start of treatment. The changes in renal function versus time were fitted by a polynomial regression through all data and interpolated values for /sup 51/CrEDTA clearance were then calculated at 30 and 40 weeks after treatment. Steep dose response curves were obtained and these were used to calculate isoeffective doses for the different fractionation schedules. There was a marked increase in total isoeffective doses from 2-30 fractions and these data were well described by a linear quadratic (L.Q.) expression for damage with an alpha/beta ratio of 2.3 +/- 0.2 Gy. There was only a slight increase in the total isoeffect dose as the size of the dose per fraction was decreased below 2 Gy and the measured isoeffect doses after 40 to 80 fractions were lower than predicted on the basis of an L.Q. model assuming complete repair between successive irradiations. The flexure dose for mouse kidneys irradiated 3 times per day was, effectively, 1 to 2 Gy and hyperfractionation using lower doses per fraction did not lead to significant, additional repair.

  3. 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

  4. 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.

  5. 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.

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

    PubMed

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

    2016-06-01

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

  7. Parametric identification of a vibratory system with a clearance

    NASA Technical Reports Server (NTRS)

    Alexander, R. M.; Noah, S. T.; Franck, C. G.

    1993-01-01

    An analytical and experimental investigation of a vibratory system with a clearance was conducted. A finite element model and an equivalent single-degree-of-freedom closed-form solution were used to determine the dynamic parameters and response of an experimental structure interacting with a gap. The closed-form solution is obtained by taking advantage of the piecewise linearity of the system. Results from these solution methods are in agreement with experimental data. The results also suggest that the closed-form solution approximates the response of the experimental structure with accuracy greater than that of the finite element model. The closed-form solution was also used to determine the gap size of the structure. The parameter identification procedure utilized in this study appears to be simple to use and can be readily extended to other types of piecewise-linear multi-degree-of-freedom systems.

  8. 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.

  9. 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.

  10. Validation of Dose Calculation Codes for Clearance

    SciTech Connect

    Menon, S.; Wirendal, B.; Bjerler, J.; Studsvik; Teunckens, L.

    2003-02-27

    Various international and national bodies such as the International Atomic Energy Agency, the European Commission, the US Nuclear Regulatory Commission have put forward proposals or guidance documents to regulate the ''clearance'' from regulatory control of very low level radioactive material, in order to allow its recycling as a material management practice. All these proposals are based on predicted scenarios for subsequent utilization of the released materials. The calculation models used in these scenarios tend to utilize conservative data regarding exposure times and dose uptake as well as other assumptions as a safeguard against uncertainties. None of these models has ever been validated by comparison with the actual real life practice of recycling. An international project was organized in order to validate some of the assumptions made in these calculation models, and, thereby, better assess the radiological consequences of recycling on a practical large scale.

  11. Improved Flight Test Procedures for Flutter Clearance

    NASA Technical Reports Server (NTRS)

    Lind, Rick C.; Brenner, Martin J.; Freudinger, Lawrence C.

    1997-01-01

    Flight flutter testing is an integral part of flight envelope clearance. This paper discusses advancements in several areas that are being investigated to improve efficiency and safety of flight test programs. Results are presented from recent flight testing of the F/A-18 Systems Research Aircraft. A wingtip excitation system was used to generate aeroelastic response data. This system worked well for many flight conditions but still displayed some anomalies. Wavelet processing is used to analyze the flight data. Filtered transfer functions are generated that greatly improve system identification. A flutter margin is formulated that accounts for errors between a model and flight data. Worst-case flutter margins are computed to demonstrate the flutter boundary may lie closer to the flight envelope than previously estimated. This paper concludes with developments for a distributed flight analysis environment and on-line health monitoring.

  12. [Mucociliary clearance function and medicamentous modification].

    PubMed

    Konrad, F

    1996-09-01

    Mucociliary clearance represents a complex self-cleaning mechanism of the lung and is based on the functional unity of ciliated columnar cells and the special viscoelastic properties of the secretion produced in the tracheobronchial system. It has been known for a long time that intubation and mechanical ventilation can impair mucous transport and lead to morphological damage to the tracheobronchial mucosa. Recent studies made it clear, however, that mechanical ventilation during anaesthesia using an appropriate anaesthesiological technique has no deleterious effect on mucus transport in patients with healthy lungs. Ventilated patients in the intensive-care unit frequently have impaired mucus transport, which is associated with the development of retention of secretion and nosocomial pneumonia. In these patients a number of factors combine to form a formidable potential insult to the mucociliary transport mechanism. Numerous drugs can affect mucociliary transport. Beta-mimetics and theophylline, in particular, have a favourable effect on mucociliary transport, whereas the effect of mucolytic agents is controversial.

  13. Anthrax edema toxin impairs clearance in mice.

    PubMed

    Sastalla, Inka; Tang, Shixing; Crown, Devorah; Liu, Shihui; Eckhaus, Michael A; Hewlett, Indira K; Leppla, Stephen H; Moayeri, Mahtab

    2012-02-01

    The anthrax edema toxin (ET) of Bacillus anthracis is composed of the receptor-binding component protective antigen (PA) and of the adenylyl cyclase catalytic moiety, edema factor (EF). Uptake of ET into cells raises intracellular concentrations of the secondary messenger cyclic AMP, thereby impairing or activating host cell functions. We report here on a new consequence of ET action in vivo. We show that in mouse models of toxemia and infection, serum PA concentrations were significantly higher in the presence of enzymatically active EF. These higher concentrations were not caused by ET-induced inhibition of PA endocytosis; on the contrary, ET induced increased PA binding and uptake of the PA oligomer in vitro and in vivo through upregulation of the PA receptors TEM8 and CMG2 in both myeloid and nonmyeloid cells. ET effects on protein clearance from circulation appeared to be global and were not limited to PA. ET also impaired the clearance of ovalbumin, green fluorescent protein, and EF itself, as well as the small molecule biotin when these molecules were coinjected with the toxin. Effects on injected protein levels were not a result of general increase in protein concentrations due to fluid loss. Functional markers for liver and kidney were altered in response to ET. Concomitantly, ET caused phosphorylation and activation of the aquaporin-2 water channel present in the principal cells of the collecting ducts of the kidneys that are responsible for fluid homeostasis. Our data suggest that in vivo, ET alters circulatory protein and small molecule pharmacokinetics by an as-yet-undefined mechanism, thereby potentially allowing a prolonged circulation of anthrax virulence factors such as EF during infection.

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

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Ground clearance: tail rotor guard. 29.411 Section 29.411 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... System Loads § 29.411 Ground clearance: tail rotor guard. (a) It must be impossible for the tail rotor...

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

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Ground clearance: tail rotor guard. 29.411 Section 29.411 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... System Loads § 29.411 Ground clearance: tail rotor guard. (a) It must be impossible for the tail rotor...

  16. 14 CFR 29.411 - Ground clearance: tail rotor guard.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Ground clearance: tail rotor guard. 29.411 Section 29.411 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... System Loads § 29.411 Ground clearance: tail rotor guard. (a) It must be impossible for the tail rotor...

  17. 14 CFR 27.411 - Ground clearance: tail rotor guard.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Ground clearance: tail rotor guard. 27.411 Section 27.411 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... System Loads § 27.411 Ground clearance: tail rotor guard. (a) It must be impossible for the tail rotor...

  18. 14 CFR 27.411 - Ground clearance: tail rotor guard.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Ground clearance: tail rotor guard. 27.411 Section 27.411 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... System Loads § 27.411 Ground clearance: tail rotor guard. (a) It must be impossible for the tail rotor...

  19. 14 CFR 27.411 - Ground clearance: tail rotor guard.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Ground clearance: tail rotor guard. 27.411 Section 27.411 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... System Loads § 27.411 Ground clearance: tail rotor guard. (a) It must be impossible for the tail rotor...

  20. 14 CFR 29.411 - Ground clearance: tail rotor guard.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Ground clearance: tail rotor guard. 29.411 Section 29.411 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... System Loads § 29.411 Ground clearance: tail rotor guard. (a) It must be impossible for the tail rotor...

  1. 14 CFR 27.411 - Ground clearance: tail rotor guard.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Ground clearance: tail rotor guard. 27.411 Section 27.411 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... System Loads § 27.411 Ground clearance: tail rotor guard. (a) It must be impossible for the tail rotor...

  2. 76 FR 17978 - Agency Information Collection Activities: Emergency Clearance Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-31

    ... From the Federal Register Online via the Government Publishing Office SOCIAL SECURITY ADMINISTRATION Agency Information Collection Activities: Emergency Clearance Request The Social Security Administration (SSA) publishes a list of information collection packages requiring clearance by the Office of Management and Budget (OMB) in compliance...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. Mechanistic evaluation of virus clearance by depth filtration.

    PubMed

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

    2015-01-01

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

  9. 49 CFR 229.71 - Clearance above top of rail.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 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....

  10. 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....

  11. 19 CFR 122.26 - Entry and clearance.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 1 2011-04-01 2011-04-01 false Entry and clearance. 122.26 Section 122.26 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY... information as set forth in § 122.22(c), and grants electronic clearance via electronic mail or telephone....

  12. 14 CFR 29.411 - Ground clearance: tail rotor guard.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ground clearance: tail rotor guard. 29.411 Section 29.411 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... System Loads § 29.411 Ground clearance: tail rotor guard. (a) It must be impossible for the tail rotor...

  13. 5 CFR 720.307 - Interagency report clearance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Interagency report clearance. 720.307 Section 720.307 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE... Interagency report clearance. The reports contained in this regulation have been cleared in accordance...

  14. 10 CFR 95.53 - 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. 95.53 Section 95.53 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) FACILITY SECURITY CLEARANCE AND SAFEGUARDING OF NATIONAL SECURITY INFORMATION AND RESTRICTED DATA Control of Information § 95.53 Termination of facility...

  15. Benefits of Improved HP Turbine Active Clearance Control

    NASA Technical Reports Server (NTRS)

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

    2007-01-01

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

  16. 48 CFR 245.7310-8 - Antitrust clearance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Antitrust clearance. 245.7310-8 Section 245.7310-8 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM... Antitrust clearance. When property with an acquisition cost of $3 million or more is to be sold, include...

  17. 30 CFR 77.514 - Switchboards; passageways and clearance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Switchboards; passageways and clearance. 77.514 Section 77.514 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE... COAL MINES Electrical Equipment-General § 77.514 Switchboards; passageways and clearance....

  18. 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 93.311 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... of Grand Canyon National Park, AZ § 93.311 Minimum terrain clearance. Except in an emergency,...

  19. 33 CFR 160.115 - Withholding of clearance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Withholding of clearance. 160.115... § 160.115 Withholding of clearance. Each District Commander or Captain of the Port may request the Secretary of the Treasury, or the authorized representative thereof, to withhold or revoke the...

  20. 7 CFR 1927.55 - Title clearance services.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 12 2012-01-01 2012-01-01 false Title clearance services. 1927.55 Section 1927.55 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE SERVICE, RURAL UTILITIES SERVICE, AND FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE PROGRAM REGULATIONS TITLE CLEARANCE AND...

  1. 32 CFR 644.69 - Title Clearance-Easements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 4 2014-07-01 2013-07-01 true Title Clearance-Easements. 644.69 Section 644.69 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL PROPERTY REAL ESTATE HANDBOOK Acquisition Procurement of Title Evidence, Title Clearance, and Closings § 644.69 Title Clearance—Easements. (a)...

  2. 32 CFR 644.69 - Title Clearance-Easements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 4 2012-07-01 2011-07-01 true Title Clearance-Easements. 644.69 Section 644.69 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL PROPERTY REAL ESTATE HANDBOOK Acquisition Procurement of Title Evidence, Title Clearance, and Closings § 644.69 Title Clearance—Easements. (a)...

  3. 32 CFR 644.69 - Title Clearance-Easements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 4 2013-07-01 2013-07-01 false Title Clearance-Easements. 644.69 Section 644.69 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL PROPERTY REAL ESTATE HANDBOOK Acquisition Procurement of Title Evidence, Title Clearance, and Closings § 644.69 Title Clearance—Easements. (a)...

  4. 7 CFR 1927.55 - Title clearance services.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 12 2014-01-01 2013-01-01 true Title clearance services. 1927.55 Section 1927.55 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE SERVICE, RURAL UTILITIES SERVICE, AND FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE PROGRAM REGULATIONS TITLE CLEARANCE AND...

  5. 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...

  6. 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 644.522 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, 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...

  8. 32 CFR 644.522 - Clearance of military scrap.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 4 2011-07-01 2011-07-01 false Clearance of military scrap. 644.522 Section 644.522 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...

  9. 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...

  10. 32 CFR 644.527 - Recording Statements of Clearance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 4 2011-07-01 2011-07-01 false 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...

  11. 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.

  12. 33 CFR 151.1508 - Revocation of clearance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Revocation of clearance. 151.1508 Section 151.1508 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... River § 151.1508 Revocation of clearance. A COTP may request the District Director of Customs...

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 48 CFR 952.204-73 - Facility clearance.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ....204-73 Section 952.204-73 Federal Acquisition Regulations System DEPARTMENT OF ENERGY CLAUSES AND... granted by the Secretary of Energy. In addition, a Facility Clearance and foreign ownership, control and... Department of Energy Facility Clearance generally need not resubmit the following foreign...

  1. 32 CFR 644.516 - Clearance of Air Force lands.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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.

  18. 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.

  19. 76 FR 36167 - Agency Information Collection Activities: Requests for Comments; Clearance of Renewed Approval of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-21

    ... Federal Aviation Administration Agency Information Collection Activities: Requests for Comments; Clearance... the request for OMB's clearance of this information collection. Issued in Washington, DC on June 15, 2011. Carla Scott, FAA Information Collection Clearance Officer, IT Enterprises Business...

  20. 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.

  1. Clearance of soluble aggregates of human immunoglobulin G in healthy volunteers and chimpanzees.

    PubMed

    Lobatto, S; Daha, M R; Voetman, A A; Evers-Schouten, J H; Van Es, A A; Pauwels, E K; Van Es, L A

    1987-07-01

    Using aggregates of IgG (AIgG) obtained by heat aggregation of a 16 g% human IgG solution, we sought a method for measuring the function of the mononuclear phagocyte system with a probe that bears more resemblance to soluble immune complexes than erythrocytes coated with anti-rhesus IgG (EIgG). It was found that intravenous administration of 10 micrograms AIgG/kg body weight did not cause any detectable side effects in chimpanzees. In nine healthy volunteers, a dose of 10 micrograms AIgG/kg body weight was used without any adverse reactions. AIgG is cleared from the human circulation with a t1/2 of 26 +/- 8 min (mean +/- SD). The site of clearance is predominantly the liver, as shown by an average liver spleen uptake ratio of 230:100. In whole blood obtained from the volunteers, it was found that erythrocytes bound significant amounts of AIgG, suggesting that CR1 on erythrocytes is involved in the clearance of complement activating immune complexes in humans. In five of the volunteers, clearance studies with EIgG had been done in a previous study. EIgG was cleared from the circulation with a t1/2 of 30 +/- 6.2 min (mean +/- SD). The predominant site of clearance of EIgG was the spleen. These data indicate that sensitized red blood cells are cleared from the circulation differently from soluble IgG aggregates.

  2. 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.

  3. 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

  4. 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

  5. Foot clearance during stair descent: effects of age and illumination.

    PubMed

    Hamel, Kathryn A; Okita, Noriaki; Higginson, Jill S; Cavanagh, Peter R

    2005-02-01

    It is likely that many stair accidents result from a trip during stair negotiation, yet few studies have examined the exact nature of balance loss during falls on stairs. The purpose of this study was to investigate potential age-related differences in the minimum clearance of the foot during stair descent, and to explore whether the minimum foot clearance was affected by the available ambient lighting. Twelve young adults (24+/-3.3 years) and 10 older adults (73.7+/-1.9 years) participated in the study. The older adults had significantly greater within subject coefficients of variation compared to the young adults, and had a significantly larger number of minimum foot clearances which fell below 5 mm. While the young subjects increased their minimum clearance by 3.6 mm on average in response to a decrease in ambient lighting, the older adults maintained the same clearance over all stairs except one. These results suggest that the variability of minimum foot clearance, and lack of precautionary increases in foot clearance under reduced lighting may contribute to falls on stairs by the elderly.

  6. 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.

  7. Levitation force of small clearance superconductor-magnet system under non-coaxial condition

    NASA Astrophysics Data System (ADS)

    Xu, Jimin; Jin, Yingze; Yuan, Xiaoyang; Miao, Xusheng

    2017-03-01

    A novel superconducting tilting-pad bearing was proposed for the advanced research of reusable liquid hydrogen turbopump in liquid rocket. The bearing is a combination of superconducting magnetic bearing and hydrodynamic fluid-film bearing. Since the viscosity of cryogenic fuel to activate superconducting state and form hydrodynamic fluid-film is very low, bearing clearance will be very small. This study focuses on the investigation of superconducting levitation force in this kind of small clearance superconductor-magnet system. Based on Bean critical state model and three-dimensional finite element method, an analysis method is presented to obtain the levitation force under such situation. Since the complicated operational conditions and structural arrangement for application in liquid rocket, center lines of bulk superconductor and magnet rotor will usually be in non-coaxial state. Superconducting levitation forces in axial direction and radial direction under non-coaxial situation are also analyzed by the presented method.

  8. The association of medication use with clearance or persistence of oral HPV infection

    PubMed Central

    Lam, Jennifer O.; Sugar, Elizabeth A.; Cranston, Ross D.; Weber, Kathleen M.; Burk, Robert D.; Wiley, Dorothy J.; Reddy, Susheel; Margolick, Joseph B.; Strickler, Howard D.; Wentz, Alicia; Jacobson, Lisa; Coles, Christian L.; Bream, Jay H.; Rositch, Anne F.; Guo, Yingshi; Xiao, Weihong; Gillison, Maura L.; D’Souza, Gypsyamber

    2017-01-01

    Purpose Persistent oral human papillomavirus (HPV) infection increases risk for oropharyngeal carcinoma, and people living with HIV have higher rates of oral HPV infection and related cancers. Some prescription medications have immunomodulatory effects, but the impact of medication use on oral HPV natural history is unknown. Methods Scope® oral rinse-and-gargle samples were collected semi-annually from 1,666 participants and tested for 37 types of oral HPV DNA using PCR; 594 HPV-infected participants with 1,358 type-specific oral HPV infections were identified. Data were collected on recent (past 6 months) use of medications. The relationship between medication use and oral HPV clearance was evaluated using Wei-Lin-Weissfeld regression, adjusting for biologic sex, prevalent vs. incident infection, age, HIV status and CD4+ T-cell count. Results Out of 11 medications examined, oral HPV clearance was significantly reduced in participants reporting recent use of antipsychotics (HR=0.75, 95% CI=0.57–0.99), anxiolytics/sedatives (HR=0.78, 95% CI=0.63–0.96) and antidepressants (HR=0.82, 95% CI=0.67–0.999). Among antipsychotics users, effect modification by HIV status was observed, with reduced clearance in HIV-infected (HR=0.67, 95%: CI 0.49–0.91), but not HIV-uninfected participants (p-interaction=0.009). After adjusted analysis, antipsychotic use remained significantly associated with reduced oral HPV clearance overall (aHR=0.75, 95% CI=0.57–0.99), and when restricted to only HIV-infected participants (aHR=0.66, 95% CI=0.48–0.90). After adjustment, anxiolytic/sedative use and antidepressant use were no longer significantly associated with reduced oral HPV clearance. Conclusions Some medications were associated with decreased oral HPV clearance, most notably antipsychotic medications. These medications are prescribed for conditions that may have immunomodulating effects, so characteristics of underlying illness may have partially contributed to reduced oral

  9. 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.

  10. Ion exchange chromatography of proteins and clearance of aggregates.

    PubMed

    Yigzaw, Y; Hinckley, P; Hewig, A; Vedantham, G

    2009-06-01

    Clearance of product related aggregates in therapeutic proteins is a major focus of purification process development. A typical purification process will have one or two chromatographic steps that remove these product related aggregates to an acceptable level. Both cation exchange and anion exchange chromatography can provide robust clearance of aggregates. The primary factors that are critical for aggregate clearance are: resin chemistry, binding and elution condition, peak collection and column load factor. This review covers how these factors can be optimized to increase the effectiveness of ion exchange chromatography in removing aggregates.

  11. 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.

  12. Laser-optical blade tip clearance measurement system

    NASA Technical Reports Server (NTRS)

    Barranger, J. P.; Ford, M. J.

    1979-01-01

    A laser-optical measurement system was developed to measure single blade tip clearances and average blade tip clearances between a rotor and its gas path seal in rotating component rigs and complete engines. The system is applicable to fan, compressor and turbine blade tip clearance measurements. The engine mounted probe is particularly suitable for operation in the extreme turbine environment. The measurement system consists of an optical subsystem, an electronic subsystem and a computing and graphic terminal. Bench tests and environmental tests were conducted to confirm operation at temperatures, pressures, and vibration levels typically encountered in an operating gas turbine engine.

  13. 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.

  14. Impact of virus clearance for the development of hemorrhagic stroke in chronic hepatitis C.

    PubMed

    Arase, Yasuji; Kobayashi, Mariko; Kawamura, Yusuke; Suzuki, Fumitaka; Suzuki, Yoshiyuki; Akuta, Norio; Kobayashi, Masahiro; Sezaki, Hitomi; Saito, Satoshi; Hosaka, Tetsuya; Ikeda, Kenji; Kumada, Hiromitsu; Kobayashi, Tetsuro

    2014-01-01

    The aim of this retrospective cohort study was to assess the cumulative incidence and predictive factors for intracerebral hemorrhagic stroke after the termination of interferon (IFN) therapy in Japanese patients with hepatitis C virus (HCV). A total of 4,649 HCV-positive patients treated with IFN were enrolled. The primary goal is the first onset of intracerebral hemorrhagic stroke. The mean observation period was 8.0 years. Evaluation was performed using the Kaplan-Meier method and the Cox proportional hazard model. A P-value of less than 0.05 was considered statistically significant. A total of 28 developed intracerebral hemorrhagic stroke. The cumulative incidence of intracerebral hemorrhagic stroke was 0.3% at 5 years, 0.8% at 10 years, and 1.7% at 15 years. Intracerebral hemorrhagic stroke occurred when patients had age increments of 10 years (hazard ratio: 2.77; 95% confidence interval (CI) 1.48-5.18; P = 0.001), hypertension (hazard ratio: 2.30; 95% CI 1.09-4.83; P = 0.021), liver cirrhosis (hazard ratio: 4.50; 95% CI 2.07-9.78; P < 0.001), and HCV non-clearance (hazard ratio: 3.22; 95% CI 1.22-8.53; P = 0.018). On the intracerebral hemorrhagic stroke based on the difference of liver fibrosis and efficacy of IFN therapy, HCV clearance reduced to 24.3% (1/4.11) compared to HCV non-clearance in cirrhotic patients (P = 0.040). In conclusion, HCV clearance reduced the development of intracerebral hemorrhagic stroke. In particular, HCV clearance reduced intracerebral hemorrhagic stroke to about one-fourth in cirrhotic patients.

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

    PubMed

    Guomao, Zheng; Yi, Wan; Jianying, Hu

    2016-06-21

    The use of trophic magnification factors (TMFs) to characterize the bioaccumulation potentials of chemicals was encouraged; however, the method for the assessment of trophic magnification potentials is still lacking. We optimized the in vitro assays used for the measurement of intrinsic clearance in liver microsomes by incorporating benzo[a]pyrene (B(a)P) as a benchmark compound. The intrinsic clearance of 40 compounds was then measured in microsomes from fish (weevers) and birds (quail); the characteristics of the trophic transfer of these 40 compounds were previously investigated in an aquatic food web in Bohai in northern China. Chemicals that are biotransformed at a rate similar to or higher than that of B[a]P in the microsomes of both weevers and quail (in vitro intrinsic clearance values, CL; CL/CLB[a]P: 0.1 to 2.4) generally exhibited no significant trophic magnification or dilution in the food web (TMF ≈ 1 or < 1), whereas chemicals that are biotransformed at extremely slow rates compared with B[a]P (CL/CLB[a]P: 0 to 0.2) showed significant trophic magnification in the food web (TMF > 1). The in vitro intrinsic clearance values of the target chemicals were found to be consistent with their respective trophic transfer behavior in the aquatic food web. Significant negative correlations were also found between the TMFs and the intrinsic clearance values of all target chemicals obtained in microsomes from both weevers and quail. Multiple linear regression analysis showed that biotransformation rates (CL/CLB[a]P) are a more important factor compared with the lipophilicity of the chemicals (log Kow) in the assessment of the trophic magnification of chemicals in the aquatic food web.

  16. 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

  17. 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.

  18. Comparison of trout hepatocytes and liver S9 fractions as in vitro models for predicting hepatic clearance in fish.

    PubMed

    Fay, Kellie A; Fitzsimmons, Patrick N; Hoffman, Alex D; Nichols, John W

    2017-02-01

    Isolated hepatocytes and liver S9 fractions have been used to collect in vitro biotransformation data for fish as a means of improving modeled estimates of chemical bioaccumulation. To date, however, there have been few direct comparisons of these 2 methods. In the present study, cryopreserved trout hepatocytes were used to measure in vitro intrinsic clearance rates for 6 polycyclic aromatic hydrocarbons (PAHs). These rates were extrapolated to estimates of in vivo intrinsic clearance and used as inputs to a well stirred liver model to predict hepatic clearance. Predicted rates of hepatic clearance were then evaluated by comparison with measured rates determined previously using isolated perfused livers. Hepatic clearance rates predicted using hepatocytes were in good agreement with measured values (<2.1-fold difference for 5 of 6 compounds) under 2 competing binding assumptions. These findings, which may be attributed in part to high rates of PAH metabolism, are similar to those obtained previously using data from liver S9 fractions. For 1 compound (benzo[a]pyrene), the in vivo intrinsic clearance rate calculated using S9 data was 10-fold higher than that determined using hepatocytes, possibly due to a diffusion limitation on cellular uptake. Generally, however, there was good agreement between calculated in vivo intrinsic clearance rates obtained using either in vitro test system. These results suggest that both systems can be used to improve bioaccumulation assessments for fish, particularly when vitro rates of activity are relatively high, although additional work is needed to determine if the chemical domain of applicability for each system differs. Environ Toxicol Chem 2017;36:463-471. Published 2016 SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

  19. 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

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

    PubMed Central

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

    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

  1. Detecting apoptotic cells and monitoring their clearance in the nematode Caenorhabditis elegans.

    PubMed

    Lu, Nan; Yu, Xiaomeng; He, Xiangwei; Zhou, Zheng

    2009-01-01

    Apoptosis is a genetically controlled process of cell suicide that plays an important role in animal development and in maintaining homeostasis. The nematode Caenorhabditis elegans has proven to be an excellent model organism for studying the mechanisms controlling apoptosis and the subsequent clearance of apoptotic cells, aided with cell-biological and genetic tools. In particular, the transparent nature of worm bodies and eggshells makes C. elegans particularly amiable for live cell microscopy. Here we describe a few methods for identifying apoptotic cells in living C. elegans embryos and adults and for monitoring their clearance during embryonic development. These methods are based on Differential Interference Contrast microscopy and on fluorescence microscopy using GFP-based reporters.

  2. 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.

  3. 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.

  4. 77 FR 44641 - Critical Infrastructure Private Sector Clearance Program Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-30

    ... SECURITY Critical Infrastructure Private Sector Clearance Program Request AGENCY: National Protection and... comments concerning Reinstatement, with change, of a previously approved ICR for the Critical... sector partners who are responsible for critical infrastructure protection but would not otherwise...

  5. Laser-optical blade tip clearance measurement system

    NASA Technical Reports Server (NTRS)

    Barranger, J. P.; Ford, M. J.

    1980-01-01

    The need for blade tip clearance instrumentation has been intensified recently by advances in technology of gas turbine engines. A new laser-optical measurement system has been developed to measure single blade tip clearances and average blade tip clearances between a rotor and its gas path seal in rotating component rigs and complete engines. The system is applicable to fan, compressor and turbine blade tip clearance measurements. The engine mounted probe is particularly suitable for operation in the extreme turbine environment. The measurement system consists of an optical subsystem, an electronic subsystem and a computing and graphic terminal. Bench tests and environmental tests were conducted to confirm operation at temperatures, pressures, and vibration levels typically encountered in an operating gas turbine engine.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. Enhanced Bomb Effects for Obstacle Clearance (Analysis Task)

    DTIC Science & Technology

    1998-01-01

    Enhanced Bomb Effects for Obstacle Clearance (Analysis Task) Tim Hennessey Diane Nell Naval Surface Warfare Center, Indian Head Division 101 Strauss...need for a system capable of simultaneously breaching obstacles and clearing mines, in-stride, from over the horizon, during an amphibious assault...In response to the obstacle -breaching concern, the Enhanced Bomb Effects for Obstacle Clearance program was started. The purpose of the NSWCDD/CSS

  11. Measuring Motor-Shaft Clearance And Wobble During Operation

    NASA Technical Reports Server (NTRS)

    Chern, Engmin James

    1996-01-01

    Noncontact proximity sensor, preferably eddy-current liftoff probe, provides realtime measurement of distance and small variations of distance between two mechanical components designed to be maintained at precise, fixed distance. In particular, system intended for use in measuring lateral clearance and variations in lateral clearance (wobble) of motor shaft relative to motor housing while shaft turning. Provides early indication of wear in motor bearings. Rate of rotation also measured.

  12. [Methohexital clearance in patients with acute hepatitis (author's transl)].

    PubMed

    Richter, E; Gallenkamp, H; Heusler, H; Zilly, W; Breimer, D D

    1979-10-26

    Pharmacokinetics of methohexital were studied in patients with acute hepatitis and after a treatment period either with "essential phospholipids" or phenobarbital. During the acute phase the distribution of methohexital was significantly altered. No change had been observed in the methohexital clearance. During remission the distribution of methohexital was in a normal range. After treatment with phenobarbital the methohexital clearance increased significantly whereas no change was observed after treatment with "essential phospholipids".

  13. Control of Small Robotic Vehicles In Unexploded Ordnance Clearance

    DTIC Science & Technology

    1997-04-01

    Proceedings of the IEEE ICRA97, Albuquerque, New Mexico, April 20-25, 1997 ISBN 0-7803-3904-5 Control of Small Robotic Vehicles In Unexploded...multiple small robotic vehicles for performing mine field clearance, and the related problem of clearing unexploded ordnance from areas of interest...charge that could be detonated upon command. Results given in this paper includes the performance of clearance operations with behavior based robots

  14. Intradialytic clearance of opioids: methadone versus hydromorphone.

    PubMed

    Perlman, Ryan; Giladi, Hili; Brecht, Krista; Ware, Mark A; Hebert, Terence E; Joseph, Lawrence; Shir, Yoram

    2013-12-01

    Opioids are commonly prescribed to patients with chronic pain associated with end-stage renal disease requiring hemodialysis. The stability of opioid analgesia during dialysis may vary among different opioids. No studies to date have corroborated this clinical observation by directly comparing plasma concentrations of different opioids during dialysis. We compared changes in peridialysis plasma concentrations of 2 pharmacokinetically distinct opioids, methadone and hydromorphone (HM). Fourteen dialysis patients with chronic pain received either methadone or HM for at least 2 weeks before beginning the study. Blood samples were obtained immediately before, during, and after hemodialysis in 2 separate dialysis sessions, 1 week apart, and were analyzed for opioid concentrations. Methadone plasma concentrations were more stable during hemodialysis compared to HM: the mean percent change of methadone plasma levels was 14.9% ± 8.2% (± SD) compared with 55.1% ± 8.1% in the HM treatment group, a difference of 40.2% (95% confidence interval 17.14 to 63.14). The mean plasma clearance of methadone was 19.9 ± 8.5 mL/min (± SD) compared with 105.7 ± 8.3 mL/min for HM, a difference of 85.7 mL/min (95% confidence interval 61.9 to 109.1). There were no differences between the 2 opioid groups in pain scores, side effect profile, and quality of life. Methadone therapy was not associated with an increased rate of adverse events. If confirmed by larger clinical studies, methadone could be considered as one of the opioids of choice in dialysis patients.

  15. 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.

  16. 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.

  17. Model of mucociliary clearance in cystic fibrosis lungs.

    PubMed

    Kurbatova, P; Bessonov, N; Volpert, V; Tiddens, H A W M; Cornu, C; Nony, P; Caudri, D

    2015-05-07

    Mucus clearance is a primary innate defense mechanism in the human airways. Cystic fibrosis (CF) is a genetic disease caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) protein. CF is characterized by dehydration of airway surface liquid and impaired mucociliary clearance. As a result, microorganisms are not efficiently removed from the airways, and patients experience chronic pulmonary infections and inflammation. We propose a new physiologically based mathematical model of muco-ciliary transport consisting of the two major components of the mucociliary clearance system: (i) periciliary liquid layer (PCL) and (ii) mucus layer. We study mucus clearance under normal conditions and in CF patients. Restoring impaired clearance of airway secretions in one of the major goals of therapy in patients with CF. We consider the action of the aerosolized and inhaled medication dornase alfa, which reduces the viscosity of cystic fibrosis mucus, by selectively cleaving the long DNA strands it contains. The results of the model simulations stress the potential relevance of the location of the drug deposition in the central or peripheral airways. Mucus clearance was increased in case the drug was primarily deposited peripherally, i.e. in the small airways.

  18. A high sensitivity inductive sensor for blade tip clearance measurement

    NASA Astrophysics Data System (ADS)

    Du, Li; Zhu, Xiaoliang; Zhe, Jiang

    2014-06-01

    A multiplexed inductive sensor consisting of multiple mini-sized planar spiral coils for detecting multiple tip clearances of rotor blades is presented. The sensor measures the tip clearances by monitoring the inductance changes of planar spiral coils caused by the passage of the rotor blades. A resonance frequency division multiplexing technique and parallel LC resonance measurement were applied to the multiple sensor coils, making it feasible to measure multiple tip clearances using only one set of measurement electronics with high sensitivity and resolution. The results from tests conducted on a bench-top test rig have demonstrated that the sensor is capable of simultaneously measuring multiple tip clearances from 0 to 5 mm with a 10 μm resolution at a high rotary speed up to 80 000 RPM. With its high resolution, high sensitivity and capability of monitoring a large number of tip clearances simultaneously, this sensor can potentially be used for advanced active tip clearance control in turbine machinery.

  19. Blood flow in exercising muscles by xenon clearance and by microsphere trapping

    SciTech Connect

    Cerretelli, P.; Marconi, C.; Pendergast, D.; Meyer, M.; Heisler, N.; Piiper, J.

    1984-01-01

    The accuracy of muscle blood flow measurement by the /sup 133/Xe clearance method (Qxe) was assessed against direct venous outflow (Qv) and microsphere trapping flow (Q..mu..) determinations in isolated perfused dog gastrocnemius both at rest and during graded stimulation (O/sub 2/ consumption (Vo/sub 2/) up to 12 ml x 100 g/sup -1/ x min/sup -1/) and in the gastrocnemius, vastus lateralis, and triceps of intact dogs at rest and while running on a treadmill at varied speeds up to maximum Vo/sub 2/. In 29 measurements performed in 11 isolated muscles, Q..mu.. was in good agreement with Qv at rest and at all stimulation levels (Q..mu../Qv = 1.0 r = 0.98). /sup 133/Xe clearance yielded much lower blood flows than the venous outflow and the microsphere trapping methods. In 43 measurements in 11 muscles, the mean Qxe/Qv ratio was 0.57 +/- 0.03 (SE), independent of blood flow. Similarly, in 65 measurements in 2 intact dogs, the mean Qxe/Q..mu.. ratio in all tested muscles was 0.49 +/- 0.02 (SE), independent of blood flow. These results show that the /sup 133/Xe clearance method considerably underestimates blood flow in dog muscles.

  20. 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.

  1. 48 CFR 245.603-70 - Contractor performance of plant clearance duties.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... plant clearance duties. 245.603-70 Section 245.603-70 Federal Acquisition Regulations System DEFENSE..., Redistribution, and Disposal of Contractor Inventory 245.603-70 Contractor performance of plant clearance duties... clearance functions if the volume of plant clearance warrants performance by the contractor. (2) The...

  2. 48 CFR 245.7101-4 - DD Form 1640, Request for Plant Clearance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Plant Clearance. 245.7101-4 Section 245.7101-4 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CONTRACT MANAGEMENT GOVERNMENT PROPERTY Plant Clearance Forms 245.7101-4 DD Form 1640, Request for Plant Clearance. Use to request plant clearance assistance...

  3. 48 CFR 245.7002 - Duties and responsibilities of plant clearance officers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... responsibilities of plant clearance officers. 245.7002 Section 245.7002 Federal Acquisition Regulations System... Appointment of Property Administrators and Plant Clearance Officers 245.7002 Duties and responsibilities of plant clearance officers. The plant clearance officer shall— (a) Instruct the contractor on...

  4. Clearance Prediction of Targeted Covalent Inhibitors by In Vitro-In Vivo Extrapolation of Hepatic and Extrahepatic Clearance Mechanisms.

    PubMed

    Leung, Louis; Yang, Xin; Strelevitz, Timothy J; Montgomery, Justin; Brown, Matthew F; Zientek, Michael A; Banfield, Christopher; Gilbert, Adam M; Thorarensen, Atli; Dowty, Martin E

    2017-01-01

    The concept of target-specific covalent enzyme inhibitors appears attractive from both an efficacy and a selectivity viewpoint considering the potential for enhanced biochemical efficiency associated with an irreversible mechanism. Aside from potential safety concerns, clearance prediction of covalent inhibitors represents a unique challenge due to the inclusion of nontraditional metabolic pathways of direct conjugation with glutathione (GSH) or via GSH S-transferase-mediated processes. In this article, a novel pharmacokinetic algorithm was developed using a series of Pfizer kinase selective acrylamide covalent inhibitors based on their in vitro-in vivo extrapolation of systemic clearance in rats. The algorithm encompasses the use of hepatocytes as an in vitro model for hepatic clearance due to oxidative metabolism and GSH conjugation, and the use of whole blood as an in vitro surrogate for GSH conjugation in extrahepatic tissues. Initial evaluations with clinical covalent inhibitors suggested that the scaling algorithm developed from rats may also be useful for human clearance prediction when species-specific parameters, such as hepatocyte and blood stability and blood binding, were considered. With careful consideration of clearance mechanisms, the described in vitro-in vivo extrapolation approach may be useful to facilitate candidate optimization, selection, and prediction of human pharmacokinetic clearance during the discovery and development of targeted covalent inhibitors.

  5. The clearance of viruses and transmissible spongiform encephalopathy agents from biologicals.

    PubMed

    Farshid, Mahmood; Taffs, Rolf E; Scott, Dorothy; Asher, David M; Brorson, Kurt

    2005-10-01

    The viral and transmissible spongiform encephalopathy (TSE) safety of therapeutics of biological origin (biologicals) is greatly influenced by the nature and degree of variability of the source material and by the mode of purification. Plasma-derived and recombinant DNA products currently have good viral safety records, but challenges remain. In general, large enveloped viruses are easier to remove from biologicals than small 'naked' viruses. Monoclonal antibodies and recombinant DNA biopharmaceuticals are derived from relatively homogeneous source materials and purified by multistep schemes that are robust and amenable to scientific analysis and engineering improvement. Viral clearance is more challenging for blood and cell products, as they are complex and labile. Source selection (e.g. country of origin, deferral for CJD risk factors) currently occupies the front line for ensuring that biologicals are free of TSE agents, but robust methods for their clearance from products are under development.

  6. [One point determination of oral caffeine clearance in patients with liver diseases].

    PubMed

    Richter, E; Brachtel, D; Hofstetter, G; Joeres, R; Klinker, H; Junggeburth, J; Epping, J; Zilly, W

    1988-12-01

    Caffeine clearance has been determined in 117 volunteers and patients (including 27 patients with liver cirrhosis) after oral application of 366.1 mg caffeine according to conventional pharmacokinetic methods (Cl = D/AUC). The resulting clearance values can be estimated with adequate accuracy from the plasma concentration at 12h for a concentration range of 2.0 to 6.5 mg/l according to Cl max = Doses/C 12h x t 12h x e and for concentrations higher than 6.5 mg/l according to Cl = Vd x (1n (D/Vd) - 1n C 12h/t 12h Vd is estimated from body weight as Vd = 0.42 x BW. "One - point" - estimation does not provide reliable data for plasma concentrations below 2.0 mg/l.

  7. 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.

  8. Inertial sensor based and shoe size independent gait analysis including heel and toe clearance estimation.

    PubMed

    Kanzler, Christoph M; Barth, Jens; Rampp, Alexander; Schlarb, Heiko; Rott, Franz; Klucken, Jochen; Eskofier, Bjoern M

    2015-01-01

    Falls are a major cause for morbidity and mortality in the ageing society. Inertial sensor based gait assessment including the analysis of the heel and toe clearance can be an indicator for the risk of falling. This paper presents a method for calculating the continuous heel and toe clearance without the knowledge of the shoe dimensions as well as the foot angle in the sagittal plane. These gait parameters were validated using an optical motion capture system. 20 healthy subjects from 3 different age groups (young, mid age, old) performed gait trials with different stride lengths and stride velocities. We obtained low mean absolute errors, low standard deviations and high Pearson correlations (0.91-0.99) for all gait parameters. In summary, we implemented a viable algorithm for the calculation of the heel and toe clearance without knowing the shoe dimensions as well as the foot angle in sagittal plane. We conclude that the given method is applicable for a mobile and unobtrusive gait assessment for healthy subjects from all age classes.

  9. Lactate clearance as the predictor of outcome in pediatric septic shock

    PubMed Central

    Choudhary, Richa; Sitaraman, Sadasivan; Choudhary, Anita

    2017-01-01

    Context: Septic shock can rapidly evolve into multiple system organ failure and death. In the recent years, hyperlactatemia has been found to be a risk factor for mortality in critically ill adults. Aims: To evaluate the predictive value of lactate clearance and to determine the optimal cut-off value for predicting outcome in children with septic shock. Settings and Design: A prospective observational study was performed on children with septic shock admitted to pediatric Intensive Care Unit (PICU). Subjects and Methods: Serial lactate levels were measured at PICU admission, 24 and 48 h later. Lactate clearance, percent decrease in lactate level in 24 h, was calculated. The primary outcome measure was survival or nonsurvival at the end of hospital stay. We performed receiver operating characteristic analyses to calculate optimal cut-off values. Results: The mean lactate levels at admission were significantly higher in the nonsurvivors than survivors, 5.12 ± 3.51 versus 3.13 ± 1.71 mmol/L (P = 0.0001). The cut-off for lactate level at admission for the best prediction of mortality was determined as ≥4 mmol/L (odds ratio 5.4; 95% confidence interval [CI] =2.45–12.09). Mean lactate clearance was significantly higher in survivors than nonsurvivors (17.9 ± 39.9 vs. −23.2 ± 62.7; P < 0.0001). A lactate clearance rate of <10% at 24 h had a sensitivity and specificity of 78.7% and 72.2%, respectively and a positive predictive value of 83.1% for death. Failure to achieve a lactate clearance of more than 10% was associated with greater risk of mortality (likelihood ratio + 2.83; 95% CI = 1.82–4.41). Conclusions: Serial lactate levels can be used to predict outcome in pediatric septic shock. A 24 h lactate clearance cut-off of <10% is a predictor of in-hospital mortality in such patients. PMID:28367008

  10. Factors associated with early mycological clearance in HIV-associated cryptococcal meningitis

    PubMed Central

    Concha-Velasco, Fátima; González-Lagos, Elsa; Seas, Carlos; Bustamante, Beatriz

    2017-01-01

    Introduction The first-line combination therapy for HIV-associated cryptococcal meningitis (CM), a condition of high mortality particularly in the first two weeks of treatment, consists of amphotericin B plus flucytosine (5-FC). Given that 5-FC remains unavailable in many countries, the knowledge of factors influencing mycological clearance in patients treated with second-line therapy could contribute to effective management. Objectives To determine the factors associated with the clearance of Cryptococcus sp. from the cerebrospinal fluid by the second week of effective antifungal therapy (early mycological clearance) in HIV-associated CM. Methods Retrospective cohort study based on secondary data corresponding to HIV-associated CM cases hospitalized at a tertiary health care center in Lima, Peru where 5-FC remains unavailable. Risk factors associated with early mycological clearance were analyzed by generalized linear regression models. Results From January 2000 to December 2013, 234 individuals were discharged with a diagnosis of HIV-associated CM; in 215 we retrieved the required data. The inpatient mortality was 20% (43/215), 15 of them in the first two weeks of treatment. In the final model (157 cases), adjusted for age, previous episode of CM, ART use, type of antifungal treatment, raised intracranial pressure, frequency of therapeutic lumbar punctures, baseline fungal burden and treatment period, the factors associated with early mycological clearance were: Amphotericin B deoxycholate plus fluconazole as combination therapy (RR, 1.56; 95% CI, 1.14–2.14); severe baseline intracranial pressure (≥35 cm H2O) (RR, 0.57; 95% CI, 0.33–0.99); and baseline fungal burden over 4.5 log10 CFU/mL (RR, 0.61 95% CI: 0.39–0.95). Conclusions In a setting without access to first-line therapy for CM, the combination therapy with amphotericin B deoxycholate plus fluconazole was positively associated with early mycological clearance, while high fungal burden and severe

  11. Clearance and binding of native and defucosylated lactoferrin.

    PubMed Central

    Imber, M J; Pizzo, S V

    1983-01-01

    These studies explore the role of carbohydrate recognition systems and the direct involvement of terminal alpha 1-3-linked fucose in the clearance of lactoferrin from the murine circulation and in the specific binding of lactoferrin to receptors on murine peritoneal macrophages. As previously reported, radiolabelled lactoferrin cleared very rapidly (t1/2 less than 1 min) after intravenous injection into mice. However, competing levels of ligands specific for the hepatic galactose receptor (asialo-orosomucoid), the hepatic fucose receptor (fucosyl-bovine serum albumin), and the mononuclear-phagocyte system pathway recognizing mannose, N-acetylglucosamine and fucose (mannosyl-, N-acetylglucosaminyl- and fucosyl-bovine serum albumin) did not block radiolabelled lactoferrin clearance in vivo or binding to mouse peritoneal macrophage monolayers in vitro. Almond emulsin alpha 1-3-fucosidase was used to prepare defucosylated lactoferrin in which 88% of the alpha 1-3-linked fucose was hydrolysed. No difference in clearance or receptor binding was observed between radiolabelled native and defucosylated lactoferrin. Fucoidin, a fucose-rich algal polysaccharide, completely inhibits the clearance in vivo and macrophage binding in vitro of lactoferrin. This effect, however, is probably not the result of competition for binding to the fucose receptor, since gel-filtration studies demonstrated formation of a stable complex between lactoferrin and fucoidin. The present results indicate that the lactoferrin-clearance pathway is distinct from several pathways mediating glycoprotein clearance through recognition of terminal galactose, fucose, N-acetylglucosamine or mannose. Furthermore, alpha 1-3-linked fucose on lactoferrin is not essential for lactoferrin clearance in vivo or specific binding to macrophage receptors in vitro. Images Fig. 3. PMID:6882370

  12. 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.

  13. Experimental and Numerical Study on Blanking Process with Negative Clearance

    NASA Astrophysics Data System (ADS)

    Hirota, Kenji; Yanaga, Hiroki; Fukushima, Katsunori

    This study summarizes the characteristics of blanking behavior with a negative clearance. Several experiments were performed for two aluminum sheets over a wide range of clearances including negative values. Blanking with negatively large clearances was found to produce fine cut edges with less roll-over and no fracture zone even for a brittle material. Corresponding simulations were performed using the Ayada's criterion for predicting ductile fracture initiation. Each zone of blanked part edges such as roll-over and fractured zone agreed well with that obtained in the experiments except a few cases accompanied by secondary shear. The reason for prevention of fracture by using negative clearances was explained with the change of the damage value during the process; the damage value was kept low throughout the blanking operation since the mean stress dominating the damage value became compressive around the die edge. Influences of blanking parameters on load-stroke curves were also investigated. The curves for negative clearances showed gradual increase in load toward the end of stroke. The earlier fracture initiated, the earlier the load reached a peak. Simulated curves showed the same tendency and in good agreement with the experimental ones quantitatively.

  14. Effect of Cilia Beat Frequency on Muco-ciliary Clearance

    PubMed Central

    Sedaghat, M.H.; Shahmardan, M.M.; Norouzi, M.; Heydari, M.

    2016-01-01

    Background: The airway surface liquid (ASL), which is a fluid layer coating the interior epithelial surface of the bronchi and bronchiolesis, plays an important defensive role against foreign particles and chemicals entering lungs. Objective: Numerical investigation has been employed to solve two-layer model consisting of mucus layer as a viscoelastic fluid and periciliary liquid layer as a Newtonian fluid to study the effects of cilia beat frequency (CBF) at various amounts of mucus properties on muco-ciliary transport problem. Methods: Hybrid finite difference-lattice Boltzmann-method (FB-LBM) has been used to solve the momentum equations and to simulate cilia forces, and also the PCL-mucus interface more accurately, immersed boundary method (IBM) has been employed. The main contribution of the current study is to use an Oldroyd-B model as the constitutive equation of mucus. Results: Our results show that increasing CBF and decreasing mucus viscosity ratio have great effects on mucus flow, but the effect of viscosity ratio is more significant. The results also illustrate that the relation between cilia beat frequency and mean mucus velocity is almost linear and it has similar behavior at different values of viscosity ratio. Conclusion: Numerical investigation based on hybrid IB-FD-LBM has been used to study the effect of CBF at various mounts of mucus viscosity ratio on the muco-ciliary clearance. The results showed that the effect of viscosity ratio on the muco-ciliary transport process is more significant compared with CBF. PMID:28144596

  15. Decrease in Urinary Creatinine Excretion in Early Stage Chronic Kidney Disease

    PubMed Central

    Tynkevich, Elena; Flamant, Martin; Haymann, Jean-Philippe; Metzger, Marie; Thervet, Eric; Boffa, Jean-Jacques; Vrtovsnik, François; Houillier, Pascal; Froissart, Marc; Stengel, Bénédicte

    2014-01-01

    Background Little is known about muscle mass loss in early stage chronic kidney disease (CKD). We used 24-hour urinary creatinine excretion rate to assess determinants of muscle mass and its evolution with kidney function decline. We also described the range of urinary creatinine concentration in this population. Methods We included 1072 men and 537 women with non-dialysis CKD stages 1 to 5, all of them with repeated measurements of glomerular filtration rate (mGFR) by 51Cr-EDTA renal clearance and several nutritional markers. In those with stage 1 to 4 at baseline, we used a mixed model to study factors associated with urinary creatinine excretion rate and its change over time. Results Baseline mean urinary creatinine excretion decreased from 15.3±3.1 to 12.1±3.3 mmol/24 h (0.20±0.03 to 0.15±0.04 mmol/kg/24 h) in men, with mGFR falling from ≥60 to <15 mL/min/1.73 m2, and from 9.6±1.9 to 7.6±2.5 (0.16±0.03 to 0.12±0.03) in women. In addition to mGFR, an older age, diabetes, and lower levels of body mass index, proteinuria, and protein intake assessed by urinary urea were associated with lower mean urinary creatinine excretion at baseline. Mean annual decline in mGFR was 1.53±0.12 mL/min/1.73 m2 per year and that of urinary creatinine excretion rate, 0.28±0.02 mmol/24 h per year. Patients with fast annual decline in mGFR of 5 mL/min/1.73 m2 had a decrease in urinary creatinine excretion more than twice as big as in those with stable mGFR, independent of changes in urinary urea as well as of other determinants of low muscle mass. Conclusions Decrease in 24-hour urinary creatinine excretion rate may appear early in CKD patients, and is greater the more mGFR declines independent of lowering protein intake assessed by 24-hour urinary urea. Normalizing urine analytes for creatininuria may overestimate their concentration in patients with reduced kidney function and low muscle mass. PMID:25401694

  16. FGF21-Mediated Improvements in Glucose Clearance Require Uncoupling Protein 1.

    PubMed

    Kwon, Michelle M; O'Dwyer, Shannon M; Baker, Robert K; Covey, Scott D; Kieffer, Timothy J

    2015-11-24

    Fibroblast growth factor 21 (FGF21)-mediated weight loss and improvements in glucose metabolism correlate with increased uncoupling protein 1 (Ucp1) levels in adipose tissues, suggesting that UCP1-dependent thermogenesis may drive FGF21 action. It was reported that FGF21 is equally effective at reducing body weight and improving glucose homeostasis without UCP1. We find while FGF21 can lower body weight in both wild-type and Ucp1 knockout mice, rapid clearance of glucose by FGF21 is defective in the absence of UCP1. Furthermore, in obese wild-type mice there is a fall in brown adipose tissue (BAT) temperature during glucose excursion, and FGF21 improves glucose clearance while preventing the fall in BAT temperature. In Ucp1 knockout mice, the fall in BAT temperature during glucose excursion and FGF21-mediated changes in BAT temperature are lost. We conclude FGF21-mediated improvements in clearance of a glucose challenge require UCP1 and evoke UCP1-dependent thermogenesis as a method to increase glucose disposal.

  17. 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.

  18. Human papillomavirus type 16 viral load measurement as a predictor of infection clearance

    PubMed Central

    Schlecht, Nicolas F.; Ramanakumar, Agnihotram V.; Villa, Luisa L.; Franco, Eduardo L.

    2013-01-01

    Viral load measurements may predict whether human papillomavirus (HPV) type 16 infections may become persistent and eventually lead to cervical lesions. Today, multiple PCR methods exist to estimate viral load. We tested three protocols to investigate viral load as a predictor of HPV clearance. We measured viral load in 418 HPV16-positive cervical smears from 224 women participating in the Ludwig–McGill Cohort Study by low-stringency PCR (LS-PCR) using consensus L1 primers targeting over 40 known HPV types, and quantitative real-time PCR (qRT-PCR) targeting the HPV16 E6 and L1 genes. HPV16 clearance was determined by MY09/11 and PGMY PCR testing on repeated smears collected over 5 years. Correlation between viral load measurements by qRT-PCR (E6 versus L1) was excellent (Spearman’s rank correlation, ρ = 0.88), but decreased for L1 qRT-PCR versus LS-PCR (ρ = 0.61). Viral load by LS-PCR was higher for HPV16 and related types independently of other concurrent HPV infections. Median duration of infection was longer for smears with high copy number by all three PCR protocols (log rank P<0.05). Viral load is inversely related to HPV16 clearance independently of concurrent HPV infections and PCR protocol. PMID:23677791

  19. Bile Duct Ligation Induces ATZ Globule Clearance In a Mouse Model of Alpha-1 Antitrypsin Deficiency

    PubMed Central

    Khan, Zahida; Yokota, Shinichiro; Ono, Yoshihiro; Bell, Aaron W.; Stolz, Donna B.; Michalopoulos, George K.

    2016-01-01

    Background Alpha-1 antitrypsin deficiency (A1ATD) can progress to cirrhosis and hepatocellular carcinoma; however, not all patients are susceptible to severe liver disease. In A1ATD, a toxic gain-of-function mutation generates insoluble ATZ “globules” in hepatocytes, overwhelming protein clearance mechanisms. The relationship between bile acids and hepatocytic autophagy is less clear, but may involve altered gene expression pathways. Based on previous findings that bile duct ligation (BDL) induces autophagy, we hypothesized that retained bile acids may have hepatoprotective effects in PiZZ transgenic mice, which model A1ATD. Methods We performed BDL and partial BDL (pBDL) in PiZZ mice, followed by analysis of liver tissues. Results PiZZ liver subjected to BDL showed up to 50% clearance of ATZ globules, with increased expression of autophagy proteins. Analysis of transcription factors revealed significant changes. Surprisingly nuclear TFEB, a master regulator of autophagy, remained unchanged. pBDL confirmed that ATZ globule clearance was induced by localized stimuli rather than diet or systemic effects. Several genes involved in bile metabolism were over-expressed in globule-devoid hepatocytes, compared to globule-containing cells. Conclusions Retained bile acids led to a dramatic reduction of ATZ globules, with enhanced hepatocyte regeneration and autophagy. These findings support investigation of synthetic bile acids as potential autophagy-enhancing agents. PMID:27938510

  20. 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.

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

    PubMed Central

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

    1996-01-01

    OBJECTIVES: To verify in vivo whether lung cinescintigraphy confirms the effect of asbestos on the patency of the smallest airways and on the efficiency of mucociliary clearance in asbestos cement workers. METHODS: 39 male subjects were examined: 30 asbestos cement workers and nine workers never exposed to occupational respiratory irritants. All subjects had a chest radiograph (International Labour Organisation (ILO) 1980); standard questionnaire on chronic bronchitis; spirometry; arterial blood gas analysis; carbon monoxide transfer factor (TLcosb); pulmonary O2 and CO2 ductances (DuO2, DuCO2); electrocardiogram; and lung cinescintigraphy after radioaerosol inhalation for the measurement of mucociliary clearance time in vivo in the smallest ciliated airways and for the assessment of radioaerosol deposition in alveoli (alveolar deposition index). RESULTS: Apart from nine non-exposed subjects, the 30 asbestos cement workers were so classified on the basis of chest radiography: nine of them as healthy exposed, 10 with pleural plaques, and 11 with asbestosis. The four groups had similar ages, work seniority, and smoking habits. Exercise dyspnoea was significantly more frequent in asbestos cement workers. Lung function variables of workers with effects related to asbestos were significantly lower than the other two groups. The PaO2, TLcOsb and DuO2 mean values were significantly lower in exposed workers than non-exposed. The mean PacO2 value was significantly higher in the asbestosis group than in the other three groups. Workers with effects related to asbestos showed a significantly lower alveolar deposition index and a significantly higher mucociliary clearance time than the other two groups. Subjects with asbestosis showed similar differences from those with pleural plaques. CONCLUSIONS: Lung cinescintigraphy confirms in vivo the effects of asbestos on bronchiolar and alveolar patency and on efficiency of mucociliary clearance in the smallest ciliated airways

  2. 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%).

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

    PubMed

    Qosa, Hisham; Kaddoumi, Amal

    2016-04-01

    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.

  4. 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

  5. Application of Dsm in Obstacle Clearance Surveying of Aerodrome

    NASA Astrophysics Data System (ADS)

    Qiao, X.; Lv, S. H.; Li, L. L.; Zhou, X. J.; Wang, H. Y.; Li, D.; Liu, J. Y.

    2016-06-01

    Compared to the wide use of digital elevation model (DEM), digital surface model (DSM) receives less attention because that it is composed by not only terrain surface, but also vegetations and man-made objects which are usually regarded as useless information. Nevertheless, these objects are useful for the identification of obstacles around an aerodrome. The primary objective of the study was to determine the applicability of DSM in obstacle clearance surveying of aerodrome. According to the requirements of obstacle clearance surveying at QT airport, aerial and satellite imagery were used to generate DSM, by means of photogrammetry, which was spatially analyzed with the hypothetical 3D obstacle limitation surfaces (OLS) to identify the potential obstacles. Field surveying was then carried out to retrieve the accurate horizontal position and height of the obstacles. The results proved that the application of DSM could make considerable improvement in the efficiency of obstacle clearance surveying of aerodrome.

  6. 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.

  7. 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.

  8. Dysregulation of Nutrient Sensing and CLEARance in Presenilin Deficiency.

    PubMed

    Reddy, Kavya; Cusack, Corey L; Nnah, Israel C; Khayati, Khoosheh; Saqcena, Chaitali; Huynh, Tuong B; Noggle, Scott A; Ballabio, Andrea; Dobrowolski, Radek

    2016-03-08

    Attenuated auto-lysosomal system has been associated with Alzheimer disease (AD), yet all underlying molecular mechanisms leading to this impairment are unknown. We show that the amino acid sensing of mechanistic target of rapamycin complex 1 (mTORC1) is dysregulated in cells deficient in presenilin, a protein associated with AD. In these cells, mTORC1 is constitutively tethered to lysosomal membranes, unresponsive to starvation, and inhibitory to TFEB-mediated clearance due to a reduction in Sestrin2 expression. Normalization of Sestrin2 levels through overexpression or elevation of nuclear calcium rescued mTORC1 tethering and initiated clearance. While CLEAR network attenuation in vivo results in buildup of amyloid, phospho-Tau, and neurodegeneration, presenilin-knockout fibroblasts and iPSC-derived AD human neurons fail to effectively initiate autophagy. These results propose an altered mechanism for nutrient sensing in presenilin deficiency and underline an importance of clearance pathways in the onset of AD.

  9. Clearance of inhaled ceramic fibers from rat lungs.

    PubMed Central

    Yamato, H; Tanaka, I; Higashi, T; Kido, M

    1994-01-01

    Deposition, clearance, retention, and durability of inhaled particles in lung are important factors for induction of pulmonary fibrosis or lung cancer. To study the deposition and clearance of aluminium silicate ceramic fibers from the lung, male Wistar rats were exposed to ceramic fibers, with a mass median aerodynamic diameter (MMAD) of 3.7 microns, for 6 hr/day, 5 days/week for 2 weeks. The average exposure concentration was 27.2 mg/m3 (SD 9.0). The rats were killed at 1 day, 1 month, 3 months, and 6 months after the end of exposure, and the fiber numbers and dimensions were measured with a scanning electron microscope. No significant difference in length of residual ceramic fibers in the lungs was found among the groups. The geometric mean diameter and number of ceramic fibers, however, decreased according to the clearance period. These findings suggest that the fibers were dissolved at their surface. PMID:7882924

  10. 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

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

    PubMed

    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.

  12. 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.

  13. 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).

  14. 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.

  15. 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.

  16. 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

  17. Radionuclide studies of bone metabolism: do bone uptake and bone plasma clearance provide equivalent measurements of bone turnover?

    PubMed

    Blake, Glen M; Siddique, Musib; Frost, Michelle L; Moore, Amelia E B; Fogelman, Ignac

    2011-09-01

    Quantitative radionuclide imaging using (18)F-fluoride positron emission tomography (18F-PET) or (99m)Tc-methylene diphosphonate ((99m)Tc-MDP) bone scans provides a novel tool for studying regional and whole skeleton bone turnover that complements the information provided by biochemical markers. Radionuclide bone scans can be quantified by measuring either tracer uptake or, if blood sampling is performed, bone plasma clearance. This study examines whether these two methods provide equivalent information about bone turnover. We examined data from two clinical trials of the bone anabolic agent teriparatide. In Study 1 twenty osteoporotic women had 18F-PET scans of the lumbar spine at baseline and after 6 months treatment with teriparatide. Bone uptake in the lumbar spine was expressed as standardised uptake values (SUV) and blood samples taken to evaluate plasma clearance. In Study 2 ten women had (99m)Tc-MDP scans at baseline, 3 and 18 months after starting teriparatide. Blood samples were taken and whole skeleton plasma clearance and bone uptake calculated. In Study 1 spine plasma clearance increased by 23.8% after 6-months treatment (P=0.0003), whilst SUV increased by only 3.0% (P=0.84). In Study 2 whole skeleton plasma clearance increased by 37.1% after 18-months treatment (P=0.0002), whilst the 4-hour whole skeleton uptake increased by only 25.5% (P=0.0001). During treatment the 18F- plasma concentration decrease by 20% and (99m)Tc-MDP concentration by 13%, and these latter changes were sufficient to explain the differences between the uptake and plasma clearance results. Measurements of response to treatment using bone uptake and plasma clearance gave different results because the effects of teriparatide on bone resulted in a sufficiently increased demand for radionuclide tracer from the skeleton that the concentration in the circulation decreased. Similar effects may occur with other therapies that have a large enough effect on bone metabolism. In these

  18. 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.

  19. Gastric clearance of alpha-1-antitrypsin under cimetidine perfusion. New test to detect protein-losing gastropathy

    SciTech Connect

    Florent, C.; Vidon, N.; Flourie, B.; Carmantrand, A.; Zerbani, A.; Maurel, M.; Bernier, J.J.

    1986-01-01

    Gastric losses of plasma are usually measured with radiolabeled macromolecules. This method is expensive and cumbersome. Direct measurement of exudated plasma proteins are ineffective since proteins are denaturated by acidic gastric juice and pepsin. It was recently shown that albumin measurement after immediate neutralization allowed detection of gastric protein losses, but this method is quite complex and time consuming. We studied alpha 1-antitrypsin and 51Cr-labeled protein clearance in gastric juice during normal saline and cimetidine (1.5 mg/kg/hr) infusion in six healthy volunteers and six patients with exudative gastropathy. alpha 1-Antitrypsin was measurable in all samples during cimetidine infusion: alpha 1-AT and 51Cr losses were significantly correlated (P less than 0.001). The upper limit of gastric alpha 1-AT clearance in controls was 0.86 ml/hr (mean + 2 SD). Using this value, there was no overlapping between patients and controls. The upper limit of 51Cr test was 1.87 ml/hr (mean + 2 SD) in controls but gastric clearance of 51Cr was below this value in one patient. This suggests that the measurement of alpha 1-AT gastric clearance during cimetidine perfusion is a good test to detect an exudative gastropathy. This test is inexpensive and lasts only 3 hr.

  20. A Single Mutation in K13 Predominates in Southern China and Is Associated With Delayed Clearance of Plasmodium falciparum Following Artemisinin Treatment

    PubMed Central

    Huang, Fang; Takala-Harrison, Shannon; Jacob, Christopher G.; Liu, Hui; Sun, Xiaodong; Yang, Henglin; Nyunt, Myaing M.; Adams, Matthew; Zhou, Shuisen; Xia, Zhigui; Ringwald, Pascal; Bustos, Maria Dorina; Tang, Linhua; Plowe, Christopher V.

    2015-01-01

    Background. Artemisinin resistance in Plasmodium falciparum has emerged in Southeast Asia and poses a threat to malaria control and elimination. Mutations in a P. falciparum gene encoding a kelch protein on chromosome 13 have been associated with delayed parasite clearance following artemisinin treatment elsewhere in the region, but not yet in China. Methods. Therapeutic efficacy studies of artesunate and dihydroartemisinin-piperaquine were conducted from 2009 to 2012 in the Yunnan Province of China near the border with Myanmar. K13 mutations were genotyped by capillary sequencing of DNA extracted from dried blood spots collected in these clinical trials and in routine surveillance. Associations between K13 mutations and delayed parasite clearance were tested using regression models. Results. Parasite clearance half-lives were prolonged after artemisinin treatment, with 44% of infections having half-lives >5 hours (n = 109). Fourteen mutations in K13 were observed, with an overall prevalence of 47.7% (n = 329). A single mutation, F446I, predominated, with a prevalence of 36.5%. Infections with F446I were significantly associated with parasitemia on day 3 following artemisinin treatment and with longer clearance half-lives. Conclusions. Plasmodium falciparum infections in southern China displayed markedly delayed clearance following artemisinin treatment. F446I was the predominant K13 mutation and was associated with delayed parasite clearance. PMID:25910630

  1. Mine Clearance Industry: Background, Geography, Funding, Analysis and Future Projections

    DTIC Science & Technology

    2007-12-01

    July 1998. 31 Paul K. Walker, Engineers of Independence, A Documentary History of the Army Engineers in the American Revolution, 1775-1783, (Honolulu...capability. Evaluation is a combination of documentary evidence and practical ability. Theatre specific Techniques/Procedures and Standards...Clearance and Detection, Bolivia, Bosnia- Herzegovina, 218 Jesuit Refugee Service NGO/INGO Humanitarian Coordination, Angola, Australia

  2. 30 CFR 57.9306 - Warning devices for restricted clearances.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... creates a hazard to persons on mobile equipment, warning devices shall be installed in advance of the... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Warning devices for restricted clearances. 57... Loading, Hauling, and Dumping Safety Devices, Provisions, and Procedures for Roadways, Railroads,...

  3. 30 CFR 56.9306 - Warning devices for restricted clearances.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... creates a hazard to persons on mobile equipment, warning devices shall be installed in advance of the... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Warning devices for restricted clearances. 56... Loading, Hauling, and Dumping Safety Devices, Provisions, and Procedures for Roadways, Railroads,...

  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. Tracheobronchial mucociliary clearance in asthma: impairment during remission.

    PubMed Central

    Pavia, D; Bateman, J R; Sheahan, N F; Agnew, J E; Clarke, S W

    1985-01-01

    Tracheobronchial mucociliary clearance was measured in eight non-smoking patients with asthma in complete remission. The patients were symptom free and required no medication whatsoever for one to six months before assessment. Mucociliary clearance was measured with an objective, radioaerosol technique. For comparison, mucociliary clearance of eight non-smoking, healthy subjects with physical characteristics and pulmonary function similar to those of the asthmatics was also measured on two occasions. In their first assessment the healthy subjects inhaled the tracer radioaerosol under experimental conditions similar to those used for the asthmatics; in the second assessment they inhaled the radioaerosol rapidly to simulate the asthmatic pattern of deposition. Under similar experimental conditions the radioaerosol was deposited more proximally in the asthmatic subjects than in the normal subjects and the difference was statistically significant (p less than 0.01). When, however, the depth of radioaerosol lung penetration was similar in the two groups, there was evidence of a significantly (p less than 0.01) poorer mucociliary clearance six hours after radioaerosol inhalation in the asthmatic than in the healthy group. These findings raise the question whether asthma ever remits completely. PMID:3983883

  6. Modifications of lung clearance mechanisms by acute influenza A infection

    SciTech Connect

    Levandowski, R.A.; Gerrity, T.R.; Garrard, C.S.

    1985-10-01

    Four volunteers with naturally acquired, culture-proved influenza A infection inhaled a radiolabeled aerosol to permit investigation of lung mucociliary clearance mechanisms during and after symptomatic illness. Mucus transport in the trachea was undetectable when monitored with an external multidetector probe within 48 hours of the onset of the illness, but was found at a normal velocity by 1 week in three of the four subjects. In two volunteers who coughed 23 to 48 times during the 4.5-hour observation period, whole lung clearance was as fast within the first 48 hours of illness as during health 3 months later in spite of the absence of measurable tracheal mucus transport. Conversely, in spite of the return 1 week later of mucus transport at velocities expected in the trachea, whole lung clearance for the 4.5-hour period was slowed in two volunteers who coughed less than once an hour. The data offer evidence that cough is important in maintaining lung clearance for at least several days after symptomatic influenza A infection when other mechanisms that depend on ciliary function are severely deficient.

  7. 50 CFR 14.53 - Detention and refusal of clearance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 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 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, 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...

  9. 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...

  10. Functional interferon system is required for clearance of lassa virus.

    PubMed

    Yun, Nadezhda E; Poussard, Allison L; Seregin, Alexey V; Walker, Aida G; Smith, Jennifer K; Aronson, Judith F; Smith, Jeanon N; Soong, Lynn; Paessler, Slobodan

    2012-03-01

    Lassa virus (LASV) is the causative agent of Lassa hemorrhagic fever (LF) in humans, a deadly disease endemic to West Africa that results in 5,000 to 10,000 deaths annually. Here we present results demonstrating that functional type I and type II interferon (IFN) signaling is required for efficient control of LASV dissemination and clearance.

  11. [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.

  12. 7 CFR 1927.55 - Title clearance services.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 12 2013-01-01 2013-01-01 false Title clearance services. 1927.55 Section 1927.55 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE SERVICE, RURAL UTILITIES SERVICE, AND FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE...

  13. An Examination of OMB Forms Clearance Aims, Policies and Procedures.

    ERIC Educational Resources Information Center

    Coan, Donald L.; Bertram, Charles L.

    The purposes of this paper are four-fold: (1) to delineate the principal aims and policy objectives of Office of Management and Budget Forms Clearance (OMB FC), as embodied in Federal legislation and executive directives since 1942; (2) to identify the major current thrusts of OMB FC; (3) to suggest possible future policy directions of OMB FC,…

  14. Some Proposals Regarding Copyright Clearance and Digitisation in Higher Education.

    ERIC Educational Resources Information Center

    Bide, Mark; Oppenheim, Charles; Ramsden, Anne

    1997-01-01

    Examines issues of copyright clearance by British universities for digitizing published printed materials. Discusses types of digitization, pricing, contract language, "compliance culture," publishers' rights, terms of licenses, and developing a publishers'"code of practice," and proposes a matrix of uses and users to support…

  15. 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.…

  16. Royalty Fees Part I: The Copyright Clearance Center and Publishers.

    ERIC Educational Resources Information Center

    Eiblum, Paula; Ardito, Stephanie C.

    1998-01-01

    Discussion of copyrights, royalty fees, and intellectual property focuses on the Copyright Clearance Center and publishers. Topics include results of a survey of library and information science journal publishers; how users verify royalty fees; how publishers determine fees; royalty fee reporting; and terms and conditions imposed on electronic…

  17. Managing Copyright Clearance Services in Higher Education Libraries.

    ERIC Educational Resources Information Center

    Gadd, Elizabeth

    2001-01-01

    Investigated centralized copyright clearance services in higher education institutions based on the findings of a questionnaire survey and five case study interviews in United Kingdom libraries. Examines reasons why services were established, how they were funded and staffed, their overall remit, problems, and good practice guidelines. (Author/LRW)

  18. 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…

  19. 46 CFR 61.20-23 - Tailshaft clearance; bearing weardown.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

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

  20. 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...

  1. 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...

  2. 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...

  3. 46 CFR 61.20-23 - Tailshaft clearance; bearing weardown.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

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

  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. 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.

  6. 33 CFR 118.160 - Vertical clearance gauges.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... numerals and foot marks below “low steel” of the bridge whenever the gauge is repainted or the structure is... BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.160 Vertical clearance gauges. (a) When necessary for... distance between “low steel” of the bridge channel span (in the closed to navigation position...

  7. 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. 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,...

  8. 31 CFR 205.20 - What is a clearance pattern?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 2 2011-07-01 2011-07-01 false What is a clearance pattern? 205.20 Section 205.20 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE, DEPARTMENT OF THE TREASURY FINANCIAL MANAGEMENT SERVICE RULES AND PROCEDURES FOR EFFICIENT FEDERAL-STATE FUNDS TRANSFERS Rules...

  9. 10 CFR 95.17 - Processing facility clearance.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... related classified information, or process the facility for a facility clearance. Processing will include... concerning the foreign intelligence threat, risk of unauthorized technology transfer, type and sensitivity of... acceptable security review conducted by the NRC; (3) Submitting key management personnel for...

  10. 23 CFR Appendix B to Part 1327 - OMB Clearance

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 23 Highways 1 2011-04-01 2011-04-01 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....

  11. 23 CFR Appendix B to Part 1327 - OMB Clearance

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 23 Highways 1 2014-04-01 2014-04-01 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....

  12. 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....

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

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 23 Highways 1 2012-04-01 2012-04-01 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. 23 CFR Appendix B to Part 1327 - OMB Clearance

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 23 Highways 1 2013-04-01 2013-04-01 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....

  15. 50 CFR 14.55 - Exceptions to clearance requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... wildlife: (a) Shellfish and fishery products imported for purposes of human or animal consumption or taken... 50 Wildlife and Fisheries 1 2013-10-01 2013-10-01 false Exceptions to clearance requirements. 14.55 Section 14.55 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF...

  16. 50 CFR 14.55 - Exceptions to clearance requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... wildlife: (a) Shellfish and fishery products imported for purposes of human or animal consumption or taken... 50 Wildlife and Fisheries 1 2011-10-01 2011-10-01 false Exceptions to clearance requirements. 14.55 Section 14.55 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF...

  17. 50 CFR 14.55 - Exceptions to clearance requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... wildlife: (a) Shellfish and fishery products imported for purposes of human or animal consumption or taken... 50 Wildlife and Fisheries 1 2012-10-01 2012-10-01 false Exceptions to clearance requirements. 14.55 Section 14.55 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF...

  18. Determinant factor for clearance of ceramic fibres from rat lungs.

    PubMed Central

    Yamato, H; Tanaka, I; Higashi, T; Kido, M

    1992-01-01

    Deposition, clearance, retention, and durability of inhaled particles from lungs are known to be important factors for induction of pulmonary fibrosis or lung cancer. To study the deposition and clearance of alumina silicate ceramic fibres from the lung, male Wistar rats were exposed to ceramic fibre particles with a mass median aerodynamic diameter (MMAD) of 4.2 micron, for six hours a day, five days a week for two weeks. The average exposure concentration was 20.7 (standard deviation (SD) 4.5) mg/m3. The rats were killed at one day, three months, and six months after the end of exposure, and the fibre numbers and dimensions were measured with a scanning electron microscope. No significant differences in number and geometric mean length of residual ceramic fibres in the lungs were found between the groups. The geometric mean diameter, however, decreased according to the duration of the clearance period. These findings suggest that solubility of fibre contributes most in the clearance of the inhaled ceramic fibres from the lungs. PMID:1554614

  19. Determinant factor for clearance of ceramic fibres from rat lungs.

    PubMed

    Yamato, H; Tanaka, I; Higashi, T; Kido, M

    1992-03-01

    Deposition, clearance, retention, and durability of inhaled particles from lungs are known to be important factors for induction of pulmonary fibrosis or lung cancer. To study the deposition and clearance of alumina silicate ceramic fibres from the lung, male Wistar rats were exposed to ceramic fibre particles with a mass median aerodynamic diameter (MMAD) of 4.2 micron, for six hours a day, five days a week for two weeks. The average exposure concentration was 20.7 (standard deviation (SD) 4.5) mg/m3. The rats were killed at one day, three months, and six months after the end of exposure, and the fibre numbers and dimensions were measured with a scanning electron microscope. No significant differences in number and geometric mean length of residual ceramic fibres in the lungs were found between the groups. The geometric mean diameter, however, decreased according to the duration of the clearance period. These findings suggest that solubility of fibre contributes most in the clearance of the inhaled ceramic fibres from the lungs.

  20. 48 CFR 2452.237-75 - Clearance of contractor personnel.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... URBAN DEVELOPMENT CLAUSES AND FORMS SOLICITATION PROVISIONS AND CONTRACT CLAUSES Texts of Provisions and... clause in solicitations and contracts. Clearance of Contractor Personnel (OCT 1999) (a) General. This contract requires contractor employees to work in, and have access to, a HUD facility. All such...

  1. 19 CFR 4.61 - Requirements for clearance.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... vessels. (c) Verification of compliance. Before clearance is granted to a vessel bound to a foreign port... following matters: (1) Accounting for inward cargo (see § 4.62). (2) Outward Cargo Declarations; shippers.... Unless otherwise provided in this section, every vessel bound for a foreign port or ports will be...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 14 CFR 27.411 - Ground clearance: tail rotor guard.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ground clearance: tail rotor guard. 27.411 Section 27.411 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements Control Surface...

  9. 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

  10. Herpes simplex virus clearance during purification of a recombinant adeno-associated virus serotype 1 vector.

    PubMed

    Ye, Guo-jie; Scotti, Marina M; Thomas, Darby L; Wang, Lijun; Knop, David R; Chulay, Jeffrey D

    2014-12-01

    Gene delivery vectors based on adeno-associated virus (AAV) have potential utility for treatment of many genetic disorders. Current AAV vector manufacturing methods employ helper viruses to deliver functions needed to produce replication-defective recombinant AAV (rAAV) vectors, and clearance of infectious helper virus from the drug substance is essential for ensuring the safety of rAAV-based therapies. We have developed a manufacturing method for the production of rAAV vectors using a recombinant herpes simplex virus type 1 (rHSV) complementation system in suspension baby hamster kidney cells. The manufacturing process includes three primary unit operations, detergent lysis of the cell harvest and two downstream column chromatography steps, which achieve viral clearance. These unit operations inactivate and remove HSV, including replication-competent HSV present at low levels in rHSV helper stocks. Here we report results quantifying the reduction in HSV achieved during rAAV vector purification. Clearance of HSV was at least 6.84 log10 with 1% Triton X-100, 4.34 log10 with CIM Q column chromatography, and 2.86 log10 with AVB affinity chromatography. Combined, these three orthogonal methods achieved clearance of at least 14.04 log10 of HSV. The total input quantity of rHSV in a 100-liter production batch is approximately 1.2×10(12) plaque-forming units (pfu), and after purification, the concentration of residual rHSV in the resulting drug substance of approximately 450 ml would be less than 2.42×10(-5) pfu/ml. A rAAV vector produced using this method was used in a clinical trial in which subjects receive up to 100 intramuscular injections of 1.35 ml each, which would contain a maximum of 3.27×10(-3) pfu of HSV. These results support the safety of rAAV vectors produced using our rHSV complementation method.

  11. 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.

  12. 77 FR 43373 - Emergency Clearance; Public Information Collection Requirements Submitted to the Office of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-24

    ... From the Federal Register Online via the Government Publishing Office NATIONAL SCIENCE FOUNDATION... Budget; Notice AGENCY: National Science Foundation. ACTION: Emergency Clearance: Public Information... addressed to Suzanne Plimpton, Reports Clearance Officer, National Science Foundation, 4201 Wilson Blvd.,...

  13. 78 FR 56222 - Agency Information Collection Activities; Comment Request; Highly Qualified Teachers Clearance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-12

    ... Agency Information Collection Activities; Comment Request; Highly Qualified Teachers Clearance AGENCY... notice will be considered public records. Title of Collection: Highly Qualified Teachers Clearance OMB... disadvantaged students) are taught by teachers participating in an alternative route to certification...

  14. 78 FR 67344 - Highly Qualified Teachers Clearance; Extension of Public Comment Period; Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-12

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF EDUCATION Highly Qualified Teachers Clearance; Extension of Public Comment Period; Correction AGENCY: Department of... comment for an information collection entitled, ``Highly Qualified Teachers Clearance,''...

  15. 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...

  16. 77 FR 6128 - Agency Information Collection Activities: Proposed Collection; Comment Request; Generic Clearance...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-07

    ... Collection; Comment Request; Generic Clearance for the Collection of Qualitative Feedback on Agency Service... Nursing Research (NINR), National Institutes of Health (NIH), has submitted a Generic Information Collection Request (Generic ICR): ``Generic Clearance for the Collection of Qualitative Feedback on...

  17. 78 FR 72153 - Proposed Collection; Comment Request for Generic Clearance for the Collection of Qualitative...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-02

    ... 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... Clearance for the Collection of Qualitative Feedback on Agency Service Delivery. OMB Number:...

  18. 76 FR 74802 - Agency Information Collection Activities: Proposed Collection; Comment Request; Generic Clearance...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-01

    ... Collection; Comment Request; Generic Clearance for the Collection of Qualitative Feedback on Agency Service... ICR): ``Generic Clearance for the Collection of Qualitative Feedback on Agency Service Delivery '' to... policy for Extramural Research Administration, 6705 Rockledge Drive Suite 350, Bethesda, MD...

  19. 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...

  20. Effect Of Per-Capita Land Use Changes On Holocene Forest Clearance And CO2 Emissions

    NASA Astrophysics Data System (ADS)

    Ruddiman, W. F.; Ellis, E. C.

    2009-12-01

    Several recent studies have attempted to estimate the extent of land clearance in the centuries and millennia before the industrial era. These studies require scaling modern land use to modern populations and then projecting (hind casting) that relationship in some way to pre-industrial times for which population information is available. Several studies have used a one-for-one (linear) scaling for these reconstructions, with the implicit assumption that land-use practices have not changed for several millennia. But this assumption is inconsistent with decades of field-based exploration: anthropological studies of contemporary cultures that use pre-modern farming methods, as well as archeological and paleoecological investigations of past farming methods. These studies suggest that per-capita land use was much larger millennia ago and then progressively decreased toward the present. Early land use (mostly shifting cultivation) was extensive (~4 +/- 2 ha/person) because land was readily available and little labor was required. By the centuries just prior to the industrial era, average per-capita land use had fallen to just ~0.4 +/- 0.2 ha per person because population growth forced farmers to grow food on smaller areas using more labor-intensive methods. Allowance for this long-term per-capita trend boosts estimates of the size of pre-industrial carbon emissions. Prior to the introduction of mechanized agriculture in prairie and steppe regions after 1850, most agriculture took place in forested regions. If small populations millennia ago had a disproportionately large impact on forest clearance and carbon emissions to the atmosphere, then later clearance and carbon emissions must be smaller than those derived by hind casting a linear relationship between modern population and land use.

  1. 24 CFR 35.1340 - Clearance.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development LEAD-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...

  2. 24 CFR 35.1340 - Clearance.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development LEAD-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...

  3. 24 CFR 35.1340 - Clearance.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development LEAD-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...

  4. 24 CFR 35.1340 - Clearance.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development LEAD-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...

  5. 24 CFR 35.1340 - Clearance.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development LEAD-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...

  6. A High Throughput, 384-Well, Semi-Automated, Hepatocyte Intrinsic Clearance Assay for Screening New Molecular Entities in Drug Discovery.

    PubMed

    Heinle, Lance; Peterkin, Vincent; de Morais, Sonia M; Jenkins, Gary J; Badagnani, Ilaria

    2015-01-01

    A high throughput, semi-automated clearance screening assay in hepatocytes was developed allowing a scientist to generate data for 96 compounds in one week. The 384-well format assay utilizes a Thermo Multidrop Combi and an optimized LC-MS/MS method. The previously reported LCMS/ MS method reduced the analytical run time by 3-fold, down to 1.2 min injection-to-injection. The Multidrop was able to deliver hepatocytes to 384-well plates with minimal viability loss. Comparison of results from the new 384-well and historical 24-well assays yielded a correlation of 0.95. In addition, results obtained for 25 marketed drugs with various metabolism pathways had a correlation of 0.75 when compared with literature values. Precision was maintained in the new format as 8 compounds tested in ≥39 independent experiments had coefficients of variation ≤21%. The ability to predict in vivo clearances using the new stability assay format was also investigated using 22 marketed drugs and 26 AbbVie compounds. Correction of intrinsic clearance values with binding to hepatocytes (in vitro data) and plasma (in vivo data) resulted in a higher in vitro to in vivo correlation when comparing 22 marketed compounds in human (0.80 vs 0.35) and 26 AbbVie Discovery compounds in rat (0.56 vs 0.17), demonstrating the importance of correcting for binding in clearance studies. This newly developed high throughput, semi-automated clearance assay allows for rapid screening of Discovery compounds to enable Structure Activity Relationship (SAR) analysis based on high quality hepatocyte stability data in sufficient quantity and quality to drive the next round of compound synthesis.

  7. 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

  8. Initial Slope Index of Total Cerebral Blood Flow Measured by Hydrogen Clearance: A Pragmatic Evaluation

    DTIC Science & Technology

    1975-06-01

    An initial slope index of total cerebral blood flow, measured by hydrogen clearance from torcular blood, shows high correlation with flows calculated by bicompartmental analysis. In 247 flow measurements done on 41 rhesus monkeys, a linear regression analysis between these two methods of calculating flow shows a correlation coefficient of 0.9280 with a standard error about y values of plus or minus 7.63. The initial slope index is not only faster to calculate but does not require that a steady state be maintained for 10 minutes.

  9. Comparison of 51chromium-labeled ethylenediamine tetra-acetic acid and iohexol as blood markers for intestinal permeability testing in Beagle dogs.

    PubMed

    Frias, Rafael; Strube, Katrin; Ternes, Waldemar; Collado, M Carmen; Spillmann, Thomas; Sankari, Satu; Westermarck, Elias

    2012-04-01

    (51)Chromium-labeled ethylenediamine tetra-acetic acid ((51)Cr-EDTA) is the gold standard probe for assessing intestinal permeability (IP) in dogs, but exposure to radioactivity is a disadvantage. Iohexol is a safe contrast medium commonly used for medical imaging purposes and has been successfully applied more recently for the assessment of IP in animal models and humans. This study aimed at comparing (51)Cr-EDTA and iohexol as IP blood markers in dogs. A test solution containing (51)Cr-EDTA and iohexol was administered intragastrically to seven healthy laboratory Beagle dogs, and percentage recoveries in serum were calculated. The strong linear association (correlation, r=0.76 and linear regression, y=0.03+5.04x) between (51)Cr-EDTA and iohexol supports the potential usefulness of iohexol as an IP blood marker in dogs.

  10. 76 FR 54777 - Center for Devices and Radiological Health 510(k) Clearance Process; Recommendations Proposed in...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-02

    ... HUMAN SERVICES Food and Drug Administration Center for Devices and Radiological Health 510(k) Clearance... Health, The FDA 510(k) Clearance Process at 35 Years''; Public Meeting; Correction AGENCY: Food and Drug... Devices and the Public's Health, The FDA 510(k) Clearance Process at 35 Years.' '' The document...

  11. 49 CFR 236.22 - Semaphore signal arm; clearance to other objects.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Semaphore signal arm; clearance to other objects... Rules and Instructions: All Systems Roadway Signals and Cab Signals § 236.22 Semaphore signal arm; clearance to other objects. At least one-half inch clearance shall be provided between semaphore signal...

  12. 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... Rules and Instructions: All Systems Roadway Signals and Cab Signals § 236.22 Semaphore signal arm; clearance to other objects. At least one-half inch clearance shall be provided between semaphore signal...

  13. 49 CFR 236.22 - Semaphore signal arm; clearance to other objects.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Semaphore signal arm; clearance to other objects... Rules and Instructions: All Systems Roadway Signals and Cab Signals § 236.22 Semaphore signal arm; clearance to other objects. At least one-half inch clearance shall be provided between semaphore signal...

  14. 49 CFR 236.22 - Semaphore signal arm; clearance to other objects.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Semaphore signal arm; clearance to other objects... Rules and Instructions: All Systems Roadway Signals and Cab Signals § 236.22 Semaphore signal arm; clearance to other objects. At least one-half inch clearance shall be provided between semaphore signal...

  15. 49 CFR 236.22 - Semaphore signal arm; clearance to other objects.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Semaphore signal arm; clearance to other objects... Rules and Instructions: All Systems Roadway Signals and Cab Signals § 236.22 Semaphore signal arm; clearance to other objects. At least one-half inch clearance shall be provided between semaphore signal...

  16. Wide Area Recovery and Resiliency Program (WARRP) Interim Clearance Strategy for Environments Contaminated with Cesium-137

    DTIC Science & Technology

    2012-07-01

    Wide Area Recovery & Resiliency Program (WARRP) Interim Clearance Strategy for Environments Contaminated with Cesium -137 July...and Resiliency Program (WARRP) Interim Clearance Strategy for Environments Contaminated with Cesium -137 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c...speedy recovery. 15. SUBJECT TERMS WARRP, Cesium -137, Clearance Strategy, Remediation 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT

  17. 75 FR 370 - Emergency Clearance: Public Information Collection Requirements Submitted to the Office of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-05

    ... [Document Identifier: CMS-10310] Emergency Clearance: Public Information Collection Requirements Submitted... reasonably comply with the normal clearance procedures due to an unexpected event as stated in 5 CFR 1320.13... processed under the emergency clearance process. Approval of this package is essential in order to...

  18. 77 FR 14807 - Emergency Clearance: Public Information Collection Requirements Submitted to the Office of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-13

    ... HUMAN SERVICES Centers for Medicare and Medicaid Services Emergency Clearance: Public Information... section 1862(a)(1)(A) of the Social Security Act. We cannot reasonably comply with the normal clearance procedures in that public harm is reasonably likely to result if normal clearance procedures are followed...

  19. 76 FR 39114 - Agency Information Collection Activities: Vessel Entrance or Clearance Statement

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-05

    ... Clearance Statement AGENCY: U.S. Customs and Border Protection (CBP), Department of Homeland Security... concerning the Vessel Entrance or Clearance Statement (CBP Form 1300). This request for comment is being made... or Clearance Statement. OMB Number: 1651-0019. Form Number: CBP Form 1300. Abstract: CBP Form...

  20. 78 FR 5858 - Agency Information Collection Activities: Requests for Comments; Clearance of Renewed Approval of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-28

    ... Federal Aviation Administration Agency Information Collection Activities: Requests for Comments; Clearance.../or include your comments in the request for OMB's clearance of this information collection. Issued in Washington, DC, on January 22, 2013. Albert R. Spence, FAA Assistant Information Collection Clearance...