A Novel Chronic Opioid Monitoring Tool to Assess Prescription Drug Steady State Levels in Oral Fluid.

PubMed

Shaparin, Naum; Mehta, Neel; Kunkel, Frank; Stripp, Richard; Borg, Damon; Kolb, Elizabeth

2017-11-01

Interpretation limitations of urine drug testing and the invasiveness of blood toxicology have motivated the desire for the development of simpler methods to assess biologically active drug levels on an individualized patient basis. Oral fluid is a matrix well-suited for the challenge because collections are based on simple noninvasive procedures and drug concentrations better correlate to blood drug levels as oral fluid is a filtrate of the blood. Well-established pharmacokinetic models were utilized to generate oral fluid steady state concentration ranges to assess the interpretive value of the alternative matrix to monitor steady state plasma oxycodone levels. Paired oral fluid and plasma samples were collected from patients chronically prescribed oxycodone and quantitatively analyzed by liquid chromatography tandem mass spectrometry. Steady state plasma concentration ranges were calculated for each donor and converted to an equivalent range in oral fluid. Measured plasma and oral fluid oxycodone concentrations were compared with respective matrix-matched steady state ranges, using each plasma steady state classification as the control. A high degree of correlation was observed between matrices when classifying donors according to expected steady state oxycodone concentration. Agreement between plasma and oral fluid steady state classifications was observed in 75.6% of paired samples. This study supports novel application of basic pharmacokinetic knowledge to the pain management industry, simplifying and improving individualized drug monitoring and risk assessment through the use of oral fluid drug testing. Many benefits of established therapeutic drug monitoring in plasma can be realized in oral fluid for patients chronically prescribed oxycodone at steady state. © 2017 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

32 CFR 299.7 - Exempt records.

Code of Federal Regulations, 2014 CFR

2014-07-01

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Code of Federal Regulations, 2013 CFR

2013-07-01

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Code of Federal Regulations, 2012 CFR

2012-07-01

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Code of Federal Regulations, 2010 CFR

2010-07-01

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Code of Federal Regulations, 2011 CFR

2011-07-01

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Effect of antacids on predicted steady-state cimetidine concentrations.

PubMed

Russell, W L; Lopez, L M; Normann, S A; Doering, P L; Guild, R T

1984-05-01

The purpose of this study was to evaluate effects of antacids on predicted steady-state concentrations of cimetidine. Ten healthy volunteers received in random order one week apart, cimetidine and cimetidine and antacid suspension. Blood was obtained at specified times and analyzed for cimetidine. Bioavailability was assessed by comparison of peak concentration, time to peak concentration, area under the curve, and time spent over 0.5 micrograms/ml. Single-dose data were extrapolated to steady-state using computer simulation. Concurrent administration of antacid suspension reduced parameters of bioavailability approximately 30%. When steady-state conditions were simulated, concentrations of cimetidine greater than or equal to 0.5 micrograms/ml were maintained for the entire dosing interval in seven of 10 subjects. These data suggest that temporal separation of cimetidine and antacid suspension may be unnecessary.

Novel synthesis of carbon spheres supported nanoscale zero-valent iron for removal of metronidazole

NASA Astrophysics Data System (ADS)

Wang, Xiangyu; Du, Yi; Ma, Jun

2016-12-01

For the first time, carbon spheres-supported nanoscale zero-valent iron (NZVI/CSs) were successfully synthesized as functionalized composite via liquid phase reduction method and adopted for removal of a typical antibiotic, metronidazole (MNZ), from wastewater. The resultant composite (NZVI/CSs) exhibit higher reactivity, excellent stability, enhanced dispersion, and improved longevity over the reaction course due to the presence of the charged carboxyl groups and hydroxyl groups on the surfaces of CSs. The results show that 94.18% of MNZ was removed using NZVI/CSs after 6 min, while only 36.45% and 8.78% of MNZ were removed using NZVI and CSs, respectively. The galvanic cell system between NZVI and CSs was essential for enhancing MNZ reduction in aqueous solution. Furthermore, the new findings include kinetics for MNZ removal by NZVI/CSs composite could be well expressed by a revised two-parameter pseudo-first-order model. Finally, the possible degradation mechanism was proposed, which was based on the analysis of degraded products by high performance liquid chromatography-mass spectrometry (HPLC-MS). Different important factors impacting on MNZ removal (including mass ratio of NZVI to CSs, initial concentration, pH value and solution temperature) were investigated as well. Overall, this study provides a promising alternative material and environmental pollution management option for antibiotic wastewater treatment.

Development of Deposition and Characterization Systems for Thin Film Solar Cells

NASA Astrophysics Data System (ADS)

Cimaroli, Alexander J.

Photovoltaic (PV) devices are becoming more important due to a number of economic and environmental factors. PV research relies on the ability to quickly fabricate and characterize these devices. While there are a number of deposition methods that are available in a laboratory setting, they are not necessarily able to be scaled to provide high throughput in a commercial setting. A close-space sublimation (CSS) system was developed to provide a means of depositing thin films in a very controlled and scalable manner. Its viability was explored by using it to deposit the absorber layer in Zn3P2 and CdTe solar cell devices. Excellent control over morphology and growth conditions and a high level of repeatability was demonstrated in the study of textured Zn3P2 thin films. However, some limitations imposed by the structure of Zn3P 2-based PV devices showed that CSS may not be the best approach for depositing Zn3P2 thin films. Despite the inability to make Zn3P2 solar cell devices, high efficiency CdTe solar cells were fabricated using CSS. With the introduction of Perovskite-based solar cell devices, the viability of data collected from conventional J-V measurements was questioned due to the J-V hysteresis that Perovskite devices exhibited. New methods of solar cell characterization were developed in order to accurately and quickly assess the performance of hysteretic PV devices. Both J-V measurements and steady-state efficiency measurements are prone to errors due to hysteresis and maximum power point drift. To resolve both of these issues, a maximum power point tracking (MPPT) system was developed with two algorithms: a simple algorithm and a predictive algorithm. The predictive algorithm showed increased resistance to the effects of hysteresis because of its ability to predict the steady-state current after a bias step with a double exponential decay model fit. Some publications have attempted to quantify the degree of J-V hysteresis present in fabricated Perovskite-based devices, but the analysis relied on J-V measurements. The sweep rate, starting bias, illumination time, etc. would affect the value of the calculated degree of hysteresis. A method of using transient photocurrent measurements is presented to accurately quantify the degree of hysteresis for all solar cells: not just Perovskite-based devices. According to this method, almost all solar cell devices exhibit several forms of J-V hysteresis. This method may open new ways of analyzing the defects in fabricated PV devices.

32 CFR 299.6 - Fees.

Code of Federal Regulations, 2011 CFR

2011-07-01

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32 CFR 299.6 - Fees.

Code of Federal Regulations, 2013 CFR

2013-07-01

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32 CFR 299.6 - Fees.

Code of Federal Regulations, 2012 CFR

2012-07-01

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Pharmacokinetics and pharmacodynamics of levofloxacin injection in healthy Chinese volunteers and dosing regimen optimization

PubMed Central

Cao, G; Zhang, J; Wu, X; Yu, J; Chen, Y; Ye, X; Zhu, D; Zhang, Y; Guo, B; Shi, Y

2013-01-01

What is known and objective The pharmacokinetics (PK) and pharmacodynamics (PD) of levofloxacin were investigated following administration of levofloxacin injection in healthy Chinese volunteers for optimizing dosing regimen. Methods The PK study included single-dose (750 mg/150 mL) and multiple-dose (750 mg/150 mL once daily for 7 days) phases. The concentration of levofloxacin in blood and urine was determined using HPLC method. Both non-compartmental and compartmental analyses were performed to estimate PK parameters. Taking fCmax/MIC ≥5 and fAUC24 h/MIC ≥30 as a target, the cumulative fraction of response (CFR) of levofloxacin 750 mg for treatment of community-acquired pneumonia (CAP) was calculated using Monte Carlo simulation. The probability of target attainment (PTA) of levofloxacin at various minimal inhibitory concentrations (MICs) was also evaluated. Results and discussion The results of PK study showed that the Cmax and AUC0–∞ of levofloxacin were 14·94 μg/mL and 80·14 μg h/mL following single-dose infusion of levofloxacin. The half-life and average cumulative urine excretion ratio within 72 h post-dosing were 7·75 h and 86·95%, respectively. The mean Css,max, Css,min and AUC0–τ of levofloxacin at steady state following multiple doses were 13·31 μg/mL, 0·031 μg/mL and 103·7 μg h/mL, respectively. The accumulation coefficient was 1·22. PK/PD analysis revealed that the CFR value of levofloxacin 750-mg regimen against Streptococcus pneumoniae was 96·2% and 95·4%, respectively, in terms of fCmax/MIC and fAUC/MIC targets. What is new and conclusion The regimen of 750-mg levofloxacin once daily provides a satisfactory PK/PD profile against the main pathogenic bacteria of CAP, which implies promising clinical and bacteriological efficacy for patients with CAP. A large-scale clinical study is warranted to confirm these results. PMID:23701411

Ethinyl estradiol and levonorgestrel pharmacokinetics with a low-dose transdermal contraceptive delivery system, AG200-15: a randomized controlled trial.

PubMed

Archer, David F; Stanczyk, Frank Z; Rubin, Arkady; Foegh, Marie

2012-06-01

This study evaluated the ethinyl estradiol (EE) and levonorgestrel (LNG) pharmacokinetic profiles of AG200-15, a transdermal contraceptive delivery system, compared with a combination oral contraceptive (COC) containing EE 35 mcg and norgestimate 250 mcg. A Phase 1, open-label, single-center study in 36 healthy women was conducted over three cycles with a randomized crossover design. After a run-in cycle of 21 days on and 7 days off with AG200-15, participants were randomized to receive one of two treatments: a 21/7-day cycle of AG200-15 either followed or preceded by one cycle of the COC. This trial is registered on ClinicalTrials.gov under the identifier NCT01243580. During the third week of AG200-15 use, mean (±standard deviation) maximum serum concentration (C(max)), area under the curve(0-168 h) and steady-state concentration (C(ss48-168 h)) for EE were 51.3 ± 17.3 pg/mL, 6.26 ± 2.46 ng h/mL and 35.7 ± 14.5 pg/mL, respectively; for LNG, the corresponding values were 2400 ± 1140 pg/mL, 317 ± 159 ng h/mL and 1847 ± 930 pg/mL, respectively. The AG200-15 EE C(max) was approximately 60% lower and the EE C(ss) was 15%-20% lower than those obtained with the COC. The calculated daily dose of AG200-15 was equivalent to a 30-mcg EE COC. The most common adverse events (AEs; >10%) in the AG200-15 group were headache, nausea and application-site irritation. All drug-related AEs were mild, and no serious AEs were reported. EE and LNG daily exposure during AG200-15 treatment was within the range reported for a low-dose COC. The daily EE dose with AG 200-15 was equivalent to a 30-mcg COC and was safe and well tolerated. Copyright © 2012 Elsevier Inc. All rights reserved.

Effects of sewage sludge addition to Norway spruce seedlings on nitrogen availability and soil fauna in clear-cut areas.

PubMed

Nieminen, Jouni K; Räisänen, Mikko

2013-07-01

Anaerobically digested and composted sewage sludge (CSS) has been suggested to be a slow-release fertilizer in forestry and an alternative to quick-release inorganic fertilizers. The effects of CSS with or without added carbohydrate on inorganic nitrogen availability and on soil animals were tested in two Norway spruce plantations. Half of the seedlings were individually fertilized with CSS, and the rest were left as controls. Solid sucrose was added to half of the fertilized and untreated seedlings. Soil samples were taken in the autumn in the first and the second year after the treatments. CSS increased soil NH4-N (2100%), the proportion of soil NO3-N, and the N concentration of spruce needles. CSS greatly reduced the abundances of enchytraeids, tardigrades and collembolans, but increased the proportion and abundance of bacterial-feeding nematodes irrespective of carbohydrate addition. A better stabilization method needs to be developed before CSS can be used as a forest fertilizer. Copyright © 2013 Elsevier Ltd. All rights reserved.

The consciousness state space (CSS)—a unifying model for consciousness and self

PubMed Central

Berkovich-Ohana, Aviva; Glicksohn, Joseph

2014-01-01

Every experience, those we are aware of and those we are not, is embedded in a subjective timeline, is tinged with emotion, and inevitably evokes a certain sense of self. Here, we present a phenomenological model for consciousness and selfhood which relates time, awareness, and emotion within one framework. The consciousness state space (CSS) model is a theoretical one. It relies on a broad range of literature, hence has high explanatory and integrative strength, and helps in visualizing the relationship between different aspects of experience. Briefly, it is suggested that all phenomenological states fall into two categories of consciousness, core and extended (CC and EC, respectively). CC supports minimal selfhood that is short of temporal extension, its scope being the here and now. EC supports narrative selfhood, which involves personal identity and continuity across time, as well as memory, imagination and conceptual thought. The CSS is a phenomenological space, created by three dimensions: time, awareness and emotion. Each of the three dimensions is shown to have a dual phenomenological composition, falling within CC and EC. The neural spaces supporting each of these dimensions, as well as CC and EC, are laid out based on the neuroscientific literature. The CSS dynamics include two simultaneous trajectories, one in CC and one in EC, typically antagonistic in normal experiences. However, this characteristic behavior is altered in states in which a person experiences an altered sense of self. Two examples are laid out, flow and meditation. The CSS model creates a broad theoretical framework with explanatory and unificatory power. It constructs a detailed map of the consciousness and selfhood phenomenology, which offers constraints for the science of consciousness. We conclude by outlining several testable predictions raised by the CSS model. PMID:24808870

Dual Language Instruction. Center for School Success Best Practices Series

ERIC Educational Resources Information Center

Imbimbo, Josephine; Knopf, Naomi; Brady, Vivian Lee; Shimabukuro, Leanne

2009-01-01

The Center for School Success (CSS) at New Visions for Public Schools was founded in 1999 to document and disseminate innovative educational practices demonstrated by New Visions' schools that hold promise for increasing student achievement throughout New York City. Over the first year, CSS concentrated its initial documentation efforts on…

Identifying coagulopathies in the pathophysiology of cold stress syndrome in the Florida manatee Trichechus manatus latirostris.

PubMed

Barratclough, Ashley; Conner, Bobbi J; Brooks, Marjory B; Pontes Stablein, Alyssa; Gerlach, Trevor J; Reep, Roger L; Ball, Ray L; Floyd, Ruth Francis

2017-08-09

Cold stress syndrome (CSS) in the Florida manatee Trichechus manatus latirostris has been defined as morbidity and mortality resulting from prolonged exposure to water temperatures <20°C. The pathophysiology is described as multifactorial, involving nutritional, immunological and metabolic disturbances; however, the exact mechanisms are unknown. We hypothesized that thromboembolic complications contribute to the pathophysiology of CSS in addition to the previously described factors. During the winter of 2014-2015, 10 Florida manatees with clinical signs of CSS were presented to Lowry Park Zoo, Tampa, FL, USA. Thromboelastography (TEG) and coagulation panels were performed at admission. In addition, coagulation panel data from 23 retrospective CSS cases were included in the analyses. There were numerous differences between mean values of TEG and coagulation parameters for healthy manatees and those for CSS cases. Among TEG parameters, reaction time (R), clot formation time (K) and percentage of clot lysed after 30 min (LY30) values were significantly different (p < 0.05) between the 2 groups. CSS cases also had significantly higher mean D-dimer concentration and coagulation factor XI activity, prolonged mean activated partial thromboplastin time (aPTT) and significantly decreased mean antithrombin activity. These combined abnormalities include clinicopathologic criteria of disseminated intravascular coagulation, indicating an increased risk of thromboembolic disease associated with manatee CSS.

Fluctuations, Stratification and Stability in a Liquid Fluidized Bed at Low Reynolds Number

NASA Technical Reports Server (NTRS)

Segre, P. N.; McClymer, J. P.

2004-01-01

The sedimentation dynamics of extremely low polydispersity, non-colloidal, particles are studied in a liquid fluidized bed at low Reynolds number, Re much less than 1. When fluidized, the system reaches a steady state, defined where the local average volume fraction does not vary in time. In steady state, the velocity fluctuations and the particle concentrations are found to strongly depend on height. Using our results, we test a recently developed stability model for steady state sedimentation. The model describes the data well, and shows that in steady state there is a balancing of particle fluxes due to the fluctuations and the concentration gradient. Some results are also presented for the dependence of the concentration gradient in fluidized beds on particle size; the gradients become smaller as the particles become larger and fewer in number.

Chemical-specific screening criteria for interpretation of biomonitoring data for volatile organic compounds (VOCs)--application of steady-state PBPK model solutions.

PubMed

Aylward, Lesa L; Kirman, Chris R; Blount, Ben C; Hays, Sean M

2010-10-01

The National Health and Nutrition Examination Survey (NHANES) generates population-representative biomonitoring data for many chemicals including volatile organic compounds (VOCs) in blood. However, no health or risk-based screening values are available to evaluate these data from a health safety perspective or to use in prioritizing among chemicals for possible risk management actions. We gathered existing risk assessment-based chronic exposure reference values such as reference doses (RfDs), reference concentrations (RfCs), tolerable daily intakes (TDIs), cancer slope factors, etc. and key pharmacokinetic model parameters for 47 VOCs. Using steady-state solutions to a generic physiologically-based pharmacokinetic (PBPK) model structure, we estimated chemical-specific steady-state venous blood concentrations across chemicals associated with unit oral and inhalation exposure rates and with chronic exposure at the identified exposure reference values. The geometric means of the slopes relating modeled steady-state blood concentrations to steady-state exposure to a unit oral dose or unit inhalation concentration among 38 compounds with available pharmacokinetic parameters were 12.0 microg/L per mg/kg-d (geometric standard deviation [GSD] of 3.2) and 3.2 microg/L per mg/m(3) (GSD=1.7), respectively. Chemical-specific blood concentration screening values based on non-cancer reference values for both oral and inhalation exposure range from 0.0005 to 100 microg/L; blood concentrations associated with cancer risk-specific doses at the 1E-05 risk level ranged from 5E-06 to 6E-02 microg/L. The distribution of modeled steady-state blood concentrations associated with unit exposure levels across VOCs may provide a basis for estimating blood concentration screening values for VOCs that lack chemical-specific pharmacokinetic data. The screening blood concentrations presented here provide a tool for risk assessment-based evaluation of population biomonitoring data for VOCs and are most appropriately applied to central tendency estimates for such datasets. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Core-satellite species hypothesis and native versus exotic species in secondary succession

USGS Publications Warehouse

Martinez, Kelsey A.; Gibson, David J.; Middleton, Beth A.

2015-01-01

A number of hypotheses exist to explain species’ distributions in a landscape, but these hypotheses are not frequently utilized to explain the differences in native and exotic species distributions. The core-satellite species (CSS) hypothesis predicts species occupancy will be bimodally distributed, i.e., many species will be common and many species will be rare, but does not explicitly consider exotic species distributions. The parallel dynamics (PD) hypothesis predicts that regional occurrence patterns of exotic species will be similar to native species. Together, the CSS and PD hypotheses may increase our understanding of exotic species’ distribution relative to natives. We selected an old field undergoing secondary succession to study the CSS and PD hypotheses in conjunction with each other. The ratio of exotic to native species (richness and abundance) was observed through 17 years of secondary succession. We predicted species would be bimodally distributed and that exotic:native species ratios would remain steady or decrease through time under frequent disturbance. In contrast to the CSS and PD hypotheses, native species occupancies were not bimodally distributed at the site, but exotic species were. The exotic:native species ratios for both richness (E:Nrichness) and abundance (E:Ncover) generally decreased or remained constant throughout supporting the PD hypothesis. Our results suggest exotic species exhibit metapopulation structure in old field landscapes, but that metapopulation structures of native species are disrupted, perhaps because these species are dispersal limited in the fragmented landscape.

Mechanistic insights from DGT and soil solution measurements on the uptake of Ni and Cd by radish.

PubMed

Luo, Jun; Cheng, Hao; Ren, Jinghua; Davison, William; Zhang, Hao

2014-07-01

This work tests the previously proposed hypothesis that plant uptake of metals is determined dominantly by diffusional controlled or plant limiting uptake mechanisms at, respectively, low and high metal concentrations. Radish (Raphanus sativus) was grown in 13 soils spiked with Ni (10 and 100 mg kg(-1)) and Cd (0.5 and 4 mg kg(-1)) for 4 weeks to investigate the mechanisms affecting plant uptake. Soil solution concentrations, Css, of Ni and Cd were measured, along with the DGT interfacial concentration, CDGT, and the derived effective concentration in soil solution, CE. Free ion activities, aNi(2+) and aCd(2+), were obtained using WHAM 6. Although there was a poor relationship between Ni in radish roots and either Css or aNi(2+) in unamended soils, the distribution of data could be rationalized in terms of the extent of release of Ni from the soil solid phase, as identified by DGT and soil solution measurements. By contrast Ni in radish was linearly related to CE, demonstrating diffusion limited uptake. For soils amended with high concentrations of Ni, linear relationships were obtained for Ni in radish plotted against, Css, aNi(2+), and CE, consistent with the plant controlling uptake. For Ni the hypothesis concerning dominant diffusional and plant limiting uptake mechanisms was demonstrated. Poor relationships between Cd in radish and Css, aCd(2+), and CE, irrespective of amendment by Cd, showed the importance of factors other than diffusional supply, such as rhizosphere and inhibitory processes, and that fulfilment of this hypothesis is plant and metal specific.

Steady state phosphorus mass balance model during hemodialysis based on a pseudo one-compartment kinetic model.

PubMed

Leypoldt, John K; Agar, Baris U; Akonur, Alp; Gellens, Mary E; Culleton, Bruce F

2012-11-01

Mathematical models of phosphorus kinetics and mass balance during hemodialysis are in early development. We describe a theoretical phosphorus steady state mass balance model during hemodialysis based on a novel pseudo one-compartment kinetic model. The steady state mass balance model accounted for net intestinal absorption of phosphorus and phosphorus removal by both dialysis and residual kidney function. Analytical mathematical solutions were derived to describe time-dependent intradialytic and interdialytic serum phosphorus concentrations assuming hemodialysis treatments were performed symmetrically throughout a week. Results from the steady state phosphorus mass balance model are described for thrice weekly hemodialysis treatment prescriptions only. The analysis predicts 1) a minimal impact of dialyzer phosphorus clearance on predialysis serum phosphorus concentration using modern, conventional hemodialysis technology, 2) variability in the postdialysis-to-predialysis phosphorus concentration ratio due to differences in patient-specific phosphorus mobilization, and 3) the importance of treatment time in determining the predialysis serum phosphorus concentration. We conclude that a steady state phosphorus mass balance model can be developed based on a pseudo one-compartment kinetic model and that predictions from this model are consistent with previous clinical observations. The predictions from this mass balance model are theoretical and hypothesis-generating only; additional prospective clinical studies will be required for model confirmation.

Optimisation of saponin extraction conditions with Camellia sinensis var. assamica seed and its application for a natural detergent.

PubMed

Gong, Wanying; Huang, Yewei; Ji, Aibing; Peng, Wenshu; Liu, Cong; Zeng, Yin; Yang, Ruijuan; Yan, Liang; Wang, Xuanjun; Sheng, Jun

2018-04-01

Camellia sinensis var. assamica seed cake (a by-product of tea-seed oil) is an abundant resource with poor utilisation. C. sinensis var. assamica seed saponin (CSS) is one kind of non-ionic surfactant. In this study, the CSS extraction conditions were optimised by response surface methodology (RSM) and then the CSS detergent was developed. Additionally, the safety and decontamination ability of the developed detergent were evaluated. The optimised extraction conditions were including the extracting temperature of 40.04 °C, extraction time of 4.97 h, ethanol concentration of 64.11% and liquid-solid ratio of 14.57:1 mL g -1 . The formula of the CSS detergent was as follows: 20% crude CSS, 0.3% oxidised tea polyphenols (OTPs), 0.2% nisin, 0.3% sodium dehydroacetate, 0.7% sodium alginate and 0.5% sodium polyacrylate. The LD 50 of the CSS detergent exceeds 14 g kg -1 in mice, indicating the detergent was non-toxic. Both of the emulsifying and the pesticide residues removal abilities of the CSS detergent were significantly stronger than the commercial detergent. A natural tea seed saponin detergent with good safety and decontamination ability was successfully developed. This can make better use of the tea seed cake, thereby creating added value in the tea seed oil industry. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Long-distance measurement-device-independent quantum key distribution with coherent-state superpositions.

PubMed

Yin, H-L; Cao, W-F; Fu, Y; Tang, Y-L; Liu, Y; Chen, T-Y; Chen, Z-B

2014-09-15

Measurement-device-independent quantum key distribution (MDI-QKD) with decoy-state method is believed to be securely applied to defeat various hacking attacks in practical quantum key distribution systems. Recently, the coherent-state superpositions (CSS) have emerged as an alternative to single-photon qubits for quantum information processing and metrology. Here, in this Letter, CSS are exploited as the source in MDI-QKD. We present an analytical method that gives two tight formulas to estimate the lower bound of yield and the upper bound of bit error rate. We exploit the standard statistical analysis and Chernoff bound to perform the parameter estimation. Chernoff bound can provide good bounds in the long-distance MDI-QKD. Our results show that with CSS, both the security transmission distance and secure key rate are significantly improved compared with those of the weak coherent states in the finite-data case.

Estimating systemic exposure to levonorgestrel from an oral contraceptive.

PubMed

Basaraba, Cale N; Westhoff, Carolyn L; Pike, Malcolm C; Nandakumar, Renu; Cremers, Serge

2017-04-01

The gold standard for measuring oral contraceptive (OC) pharmacokinetics is the 24-h steady-state area under the curve (AUC). We conducted this study to assess whether limited sampling at steady state or measurements following use of one or two OCs could provide an adequate proxy in epidemiological studies for the progestin 24-h steady-state AUC of a particular OC. We conducted a 13-sample, 24-h pharmacokinetic study on both day 1 and day 21 of the first cycle of a monophasic OC containing 30-mcg ethinyl estradiol and 150-mcg levonorgestrel (LNG) in 17 normal-weight healthy White women and a single-dose 9-sample study of the same OC after a 1-month washout. We compared the 13-sample steady-state results with several steady-state and single-dose results calculated using parsimonious sampling schemes. The 13-sample steady-state 24-h LNG AUC was highly correlated with the steady-state 24-h trough value [r=0.95; 95% confidence interval (0.85, 0.98)] and with the steady-state 6-, 8-, 12- and 16-h values (0.92≤r≤0.95). The trough values after one or two doses were moderately correlated with the steady-state 24-h AUC value [r=0.70; 95% CI (0.27, 0.90) and 0.77; 95% CI (0.40, 0.92), respectively]. Single time-point concentrations at steady state and after administration of one or two OCs gave highly to moderately correlated estimates of steady-state LNG AUC. Using such measures could facilitate prospective pharmaco-epidemiologic studies of the OC and its side effects. A single time-point LNG concentration at steady state is an excellent proxy for complete and resource-intensive steady-state AUC measurement. The trough level after two single doses is a fair proxy for steady-state AUC. These results provide practical tools to facilitate large studies to investigate the relationship between systemic LNG exposure and side effects in a real-life setting. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of carrier concentrations on the charge transport properties in monolayer silicene

NASA Astrophysics Data System (ADS)

Abidin, B. I.; Yeoh, K. H.; Ong, D. S.; Yong, T. K.

2017-10-01

Using analytical band Monte Carlo approach, we have carried out a systematic study on the effects of carrier concentrations on the steady-state and transient electron transports that occur within a monolayer silicene. In particular, we have observed the following: First at steady-state, the electron mobility reduces with higher carrier concentrations. Secondly, in the transient regime we found that the drift velocity overshoot can be controlled by varying the carrier concentrations. We uncover that at carrier concentration of 1  ×  1013 cm-2, the drift velocity overshoot can reach up to 3.8  ×  107 cm s-1 which is close to the steady-state drift velocity saturation of graphene. Thirdly, the distance of the velocity over shoot can be further extended with higher carrier concentrations. Our findings could be useful and can be used as benchmark for future development of nanoscale silicene based devices.

Steady-state serum salicylate levels in hospitalized patients with rheumatoid arthritis. Comparison of two dosage schedules of choline magnesium trisalicylate.

PubMed

Cassell, S; Furst, D; Dromgoole, S; Paulus, H

1979-04-01

When the total daily drug dose was individualized to produce a steady-state serum salicylate concentration between 20 and 35 mg/dl, clinically acceptable fluctuations of serum concentrations occurred during both twice daily and three times daily administration. In 6 rheumatoid arthritis patients receiving choline magnesium trisalicylate, mean steady-state serum levels were the same, and the ranges of hourly mean concentrations during 8 and 12 hour dosage intervals were 19 to 27 mg/dl and 17 to 30 mg/dl, respectively. Changing the dosing interval from 8 to 12 hours required a 50% increase in the fractional doses, but resulted in an increase of only 3 mg/dl in mean peak concentration and a ddecrease of 1 mg/dl in mean minimum concentration.

Pharmacokinetic Steady-States Highlight Interesting Target-Mediated Disposition Properties.

PubMed

Gabrielsson, Johan; Peletier, Lambertus A

2017-05-01

In this paper, we derive explicit expressions for the concentrations of ligand L, target R and ligand-target complex RL at steady state for the classical model describing target-mediated drug disposition, in the presence of a constant-rate infusion of ligand. We demonstrate that graphing the steady-state values of ligand, target and ligand-target complex, we obtain striking and often singular patterns, which yield a great deal of insight and understanding about the underlying processes. Deriving explicit expressions for the dependence of L, R and RL on the infusion rate, and displaying graphs of the relations between L, R and RL, we give qualitative and quantitive information for the experimentalist about the processes involved. Understanding target turnover is pivotal for optimising these processes when target-mediated drug disposition (TMDD) prevails. By a combination of mathematical analysis and simulations, we also show that the evolution of the three concentration profiles towards their respective steady-states can be quite complex, especially for lower infusion rates. We also show how parameter estimates obtained from iv bolus studies can be used to derive steady-state concentrations of ligand, target and complex. The latter may serve as a template for future experimental designs.

Introducing Michaelis-Menten Kinetics through Simulation

ERIC Educational Resources Information Center

Halkides, Christopher J.; Herman, Russell

2007-01-01

We describe a computer tutorial that introduces the concept of the steady state in enzyme kinetics. The tutorial allows students to produce graphs of the concentrations of free enzyme, enzyme-substrate complex, and product versus time in order to learn about the approach to steady state. By using a range of substrate concentrations and rate…

[Hydrology and water quality of rainfall-runoff in combined sewerage system along Suzhou Creek in central Shanghai].

PubMed

Cheng, Jiang; Yang, Kai; Huang, Xiao-Fang; Lü, Yong-Peng

2009-07-15

In order to obtain the processes of hydrology and water quality of urban combined sewerage system (CSS) in highly urbanized region, the precipitation, discharge and pollutant concentration of four different intensity rainfall (light rain, moderate rain, heavy rain and storm) were measured from Jul. to Sep. 2007 in the Chendulu CSS along Suzhou Creek in Shanghai. The results show that the shapes of runoff graph are similar to rainfall graph, with a weaker fluctuation range and a 15-25 min delay between rainfall and runoff graph. Runoff coefficients of the four different rainfall are 0.33, 0.62, 0.67 and 0.73, respectively. The 30/30 first flush phenomenon is found in Chendulu CSS. The peak of pollutant concentration graph lags rainfall peak about 30-40 min. The pH and event mean concentration (EMC) of Cu, Zn, Cr, Cd, Pb and Ni totally measure up to environmental quality standards V for surface water of China besides COD, BOD5, NH4(+) -N and TP, and the EMC of COD, BOD5, NH4(+) -N and TP are 225.0-544.1, 31.5-98.9, 8.9-44.2 and 1.98-3.52 mg x L(-1), respectively. The rainfall-runoff pollutant concentration in Chendulu CSS is close to those of other foreign cites. At the confidence level of p < 0.01, good relationships exist between SS and COD, BOD5, NH4(+) -N and TP, respectively, and the average proportion of particulate organic pollutant and nutrient is 70.21%.

Chronic social stress leads to altered sleep homeostasis in mice.

PubMed

Olini, Nadja; Rothfuchs, Iru; Azzinnari, Damiano; Pryce, Christopher R; Kurth, Salome; Huber, Reto

2017-06-01

Disturbed sleep and altered sleep homeostasis are core features of many psychiatric disorders such as depression. Chronic uncontrollable stress is considered an important factor in the development of depression, but little is known on how chronic stress affects sleep regulation and sleep homeostasis. We therefore examined the effects of chronic social stress (CSS) on sleep regulation in mice. Adult male C57BL/6 mice were implanted for electrocortical recordings (ECoG) and underwent either a 10-day CSS protocol or control handling (CON). Subsequently, ECoG was assessed across a 24-h post-stress baseline, followed by a 4-h sleep deprivation, and then a 20-h recovery period. After sleep deprivation, CSS mice showed a blunted increase in sleep pressure compared to CON mice, as measured using slow wave activity (SWA, electroencephalographic power between 1-4Hz) during non-rapid eye movement (NREM) sleep. Vigilance states did not differ between CSS and CON mice during post-stress baseline, sleep deprivation or recovery, with the exception of CSS mice exhibiting increased REM sleep during recovery sleep. Behavior during sleep deprivation was not affected by CSS. Our data provide evidence that CSS alters the homeostatic regulation of sleep SWA in mice. In contrast to acute social stress, which results in a faster SWA build-up, CSS decelerates the homeostatic build up. These findings are discussed in relation to the causal contribution of stress-induced sleep disturbance to depression. Copyright © 2017 Elsevier B.V. All rights reserved.

Acetylcholine-activated ionic currents in parasympathetic neurons of bullfrog heart.

PubMed

Tateishi, N; Kim, D K; Akaike, N

1990-05-01

1. The electrical and pharmacologic properties of acetylcholine (ACh)-induced current (IACh) were studied in the parasympathetic neurons isolated from bullfrog heart with the use of the concentration-clamp technique, which allows intracellular perfusion and rapid change of external solution within 2 ms under the single-electrode voltage-clamp condition. 2. The IACh consisted of an initial transient peak component and a successive steady-state plateau component. Both currents increased in a sigmoidal fashion with increasing ACh concentration. The dissociation constant (Kd value) and the Hill coefficient for each component were 2.2 X 10(-5) M and 1.6, respectively. 3. In the K(+)-free solution, the reversal potential (EACh) of IACh was close to the Na+ equilibrium potential (ENa). The current-voltage (I-V) relation showed inward rectification at positive potentials. 4. Nicotine mimicked only the peak component of IACh. However both peak and steady-state components were blocked nonselectively by the nicotinic blockers d-tubocurarine and hexamethonium. 5. Carbamylcholine (CCh) mimicked the steady-state component of IACh. The steady-state component was selectively inhibited by atropine at concentrations 1,000 times lower than that required for inhibition of the peak component. The steady state was blocked equally by either pirenzepine (M1 blocker) or AF-DX-116 (M2 blocker). 6. It was concluded that the IACh consisted of a peak component having double exponential activation and inactivation, mediated through the nicotinic actions, and a steady-state component having no inactivation, mediated through the muscarinic action.

Ultrafiltration technology with a ceramic membrane for reactive dye removal: optimization of membrane performance.

PubMed

Alventosa-deLara, E; Barredo-Damas, S; Alcaina-Miranda, M I; Iborra-Clar, M I

2012-03-30

An ultrafiltration (UF) ceramic membrane was used to decolorize Reactive Black 5 (RB5) solutions at different dye concentrations (50 and 500 mg/L). Transmembrane pressure (TMP) and cross-flow velocity (CFV) were modified to study their influence on initial and steady-state permeate flux (J(p)) and dye rejection (R). Generally, J(p) increased with higher TMP and CFV and lower feed concentration, up to a maximum steady-state J(p) of 266.81 L/(m(2)h), obtained at 3 bar, 3m/s and 50mg/L. However, there was a TMP value (which changed depending on operating CFV and concentration) beyond which slight or no further increase in steady-state J(p) was observed. Similarly, the higher the CFV was, the more slightly the steady-state J(p) increased. Furthermore, the effectiveness of ultrafiltration treatment was evaluated through dye rejection coefficient. The results showed significant dye removals, regardless of the tested conditions, with steady-state R higher than 79.8% for the 50mg/L runs and around 73.2% for the 500 mg/L runs. Finally response surface methodology (RSM) was used to optimize membrane performance. At 50mg/L, a TMP of 4 bar and a CFV of 2.53 m/s were found to be the conditions giving the highest steady-state J(p), 255.86 L/(m(2)h), and the highest R, 95.2% simultaneously. Copyright © 2012 Elsevier B.V. All rights reserved.

Excitation on the Coherent States of Pseudoharmonic Oscillator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Popov, Dusan; Pop, Nicolina; Sajfert, Vjekoslav

In the last decades, much attention has been paid to the excitation on coherent states, especially for coherent states of the harmonic oscillator ([1] and references therein). But an interesting anharmonic oscillator with many potential applications is also the pseudoharmonic oscillator (PHO). So, in the present paper we have defined the excitation on the Klauder-Perelomov coherent states (E-KP-CSs) for the PHO. These states are obtained by repeatedly operating the raising operator K{sub +} on a usual Klauder-Perelomov coherent state (KP-CS) of the PHO [2]. We have verified that really, the E-KP-CSs fulfill all the properties of the coherent states, asmore » stated by Klauder [3]. We have examined the nonclassical properties of the E-KP-CSs, by using the density matrix formalism and examining the dependence of the Mandel parameter Q{sub z,k;m}(|z|{sup 2}) on the |z|{sup 2} and on the m. It seems that these states can be used in optical communication field and in the physics of quantum information, as signal beams, due to the fact that in these fields the nonclassicality plays an important role.« less

Auditory fear conditioning modifies steady-state evoked potentials in the rat inferior colliculus.

PubMed

Lockmann, André Luiz Vieira; Mourão, Flávio Afonso Gonçalves; Moraes, Marcio Flávio Dutra

2017-08-01

The rat inferior colliculus (IC) is a major midbrain relay for ascending inputs from the auditory brain stem and has been suggested to play a key role in the processing of aversive sounds. Previous studies have demonstrated that auditory fear conditioning (AFC) potentiates transient responses to brief tones in the IC, but it remains unexplored whether AFC modifies responses to sustained periodic acoustic stimulation-a type of response called the steady-state evoked potential (SSEP). Here we used an amplitude-modulated tone-a 10-kHz tone with a sinusoidal amplitude modulation of 53.7 Hz-as the conditioning stimulus (CS) in an AFC protocol (5 CSs per day in 3 consecutive days) while recording local field potentials (LFPs) from the IC. In the preconditioning session ( day 1 ), the CS elicited prominent 53.7-Hz SSEPs. In the training session ( day 2 ), foot shocks occurred at the end of each CS (paired group) or randomized in the inter-CS interval (unpaired group). In the test session ( day 3 ), SSEPs markedly differed from preconditioning in the paired group: in the first two trials the phase to which the SSEP coupled to the CS amplitude envelope shifted ~90°; in the last two trials the SSEP power and the coherence of SSEP with the CS amplitude envelope increased. LFP power decreased in frequency bands other than 53.7 Hz. In the unpaired group, SSEPs did not change in the test compared with preconditioning. Our results show that AFC causes dissociated changes in the phase and power of SSEP in the IC. NEW & NOTEWORTHY Local field potential oscillations in the inferior colliculus follow the amplitude envelope of an amplitude-modulated tone, originating a neural response called the steady-state evoked potential. We show that auditory fear conditioning of an amplitude-modulated tone modifies two parameters of the steady-state evoked potentials in the inferior colliculus: first the phase to which the evoked oscillation couples to the amplitude-modulated tone shifts; subsequently, the evoked oscillation power increases along with its coherence with the amplitude-modulated tone. Copyright © 2017 the American Physiological Society.

In vitro evaluation of the Medtronic cardioplegia safety system.

PubMed

Trowbridge, C C; Woods, K R; Muhle, M L; Niimi, K S; Tremain, K D; Jiang, J; Stammers, A H

2000-03-01

Myocardial preservation demands the precise and accurate delivery of cardioplegic solutions to provide nutritive delivery and metabolic waste removal. The purpose of this study was to evaluate the performance characteristics of the Medtronic CSS Cardioplegia Safety System in an in vitro setting. The CSS was evaluated under the following conditions: blood to crystalloid ratios of 1:0, 1:1, 4:1, 8:1, 0:1; potassium concentrations of 10, 20, and 40 mEq L-1; volumetric delivery collection at 100, 250, 500, 750, and 990 mL/min; pressure accuracy at 100 and 300 mmHg; and system safety mechanisms. Measured and predicted values from the CSS were compared using one way ANOVA, with statistical significance accepted at p < or = 0.05. The measured values for the tested ratios and volume collections were all within the manufacturer's technical parameters. Potassium concentration results were all within expected values except at 100 mL/min, where the measured value of 17.1 +/- 2.1 mmol was lower than the expected 20.0 +/- 0.2 mmol (p < .034). As flow rates changed, the CSS line pressure error was constant (0.5 to 3.7%), and the only significant difference was observed at 100 mmHg, 500 mL/min (102.3 +/- 1.7 vs. 100.0 +/- 0.0 mmHg, P < .003). The device performed accurately and reliably under all simulated safety conditions, including bubble detection, over pressurization and battery backup. In conclusion, the performance of the CSS was within the manufacturer's specifications for the majority of the tested conditions and operated safely when challenged under varying conditions.

Steady-state pharmacokinetics of isotretinoin and its 4-oxo metabolite: implications for fetal safety.

PubMed

Nulman, I; Berkovitch, M; Klein, J; Pastuszak, A; Lester, R S; Shear, N; Koren, G

1998-10-01

Isotretinoin is the most potent human teratogen on the market. Women for whom contraception fails may conceive during or soon after discontinuing isotretinoin therapy, making its elimination kinetics a crucial determinant of fetal safety. The steady-state pharmacokinetics of isotretinoin and its major 4-oxo metabolite were studied in 16 adult patients treated for acne who were receiving doses that ranged from 0.47 to 1.7 mg/kg daily. This is the first study of the pharmacokinetics of isotretinoin in women of childbearing age (n = 11). The clinical efficacy and tolerability of isotretinoin was investigated, and the correlation between these data and steady-state serum concentrations of isotretinoin was tested. The concentration-time data best fitted a two-compartment open model with linear elimination. There was no correlation between efficacy and tolerability of isotretinoin and steady-state serum concentrations. There was no correlation between dose of isotretinoin and steady-state concentration, due to the large variability in apparent clearance. Values for elimination half-life (t1/2) of isotretinoin and its metabolite were 29+/-40 hours and 22+/-10 hours, respectively. These data suggest a longer elimination t1/2 of the parent drug than previously reported. This is probably due to the longer sampling time used in this study (as long as 28 days). This study suggests that a greater variability exists in the safe time after discontinuation of the drug for onset of conception.

Analytical solution and simplified analysis of coupled parent-daughter steady-state transport with multirate mass transfer

Treesearch

R. Haggerty

2013-01-01

In this technical note, a steady-state analytical solution of concentrations of a parent solute reacting to a daughter solute, both of which are undergoing transport and multirate mass transfer, is presented. Although the governing equations are complicated, the resulting solution can be expressed in simple terms. A function of the ratio of concentrations, In (daughter...

Chemostat studies of bacteriophage M13 infected Escherichia coli JM109 for continuous ssDNA production.

PubMed

Kick, Benjamin; Behler, Karl Lorenz; Severin, Timm Steffen; Weuster-Botz, Dirk

2017-09-20

Steady state studies in a chemostat enable the control of microbial growth rate at defined reaction conditions. The effects of bacteriophage M13 infection on maximum growth rate of Escherichia coli JM109 were studied in parallel operated chemostats on a milliliter-scale to analyze the steady state kinetics of phage production. The bacteriophage infection led to a decrease in maximum specific growth rate of 15% from 0.74h -1 to 0.63h -1 . Under steady state conditions, a constant cell specific ssDNA formation rate of 0.15±0.004 mg ssDNA g CDW -1 h -1 was observed, which was independent of the growth rate. Using the estimated kinetic parameters for E. coli infected with bacteriophage M13, the ssDNA concentration in the steady state could be predicted as function of the dilution rate and the glucose concentration in the substrate. Scalability of milliliter-scale data was approved by steady state studies on a liter-scale at a selected dilution rate. An ssDNA space-time yield of 5.7mgL -1 h -1 was achieved with increased glucose concentration in the feed at a dilution rate of 0.3h -1 , which is comparable to established fed-batch fermentation with bacteriophage M13 for ssDNA production. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of diffusion coefficients by means of an approximate steady-state condition in sedimentation velocity distributions.

PubMed

Scott, David J; Harding, Stephen E; Winzor, Donald J

2015-12-01

This investigation examined the feasibility of manipulating the rotor speed in sedimentation velocity experiments to spontaneously generate an approximate steady-state condition where the extent of diffusional spreading is matched exactly by the boundary sharpening arising from negative s-c dependence. Simulated sedimentation velocity distributions based on the sedimentation characteristics for a purified mucin preparation were used to illustrate a simple procedure for determining the diffusion coefficient from such steady-state distributions in situations where the concentration dependence of the sedimentation coefficient, s = s(0)/(1 + Kc), was quantified in terms of the limiting sedimentation coefficient as c → 0 (s(0)) and the concentration coefficient (K). Those simulations established that spontaneous generation of the approximate steady state could well be a feature of sedimentation velocity distributions for many unstructured polymer systems because the requirement that Kcoω(2)s(0)/D be between 46 and 183 cm(-2) is not unduly restrictive. Although spontaneous generation of the approximate steady state is also a theoretical prediction for structured macromolecular solutes exhibiting linear concentration dependence of the sedimentation coefficient, s = s(0)(1 - kc), the required value of k is far too large for any practical advantage to be taken of this approach with globular proteins. Copyright © 2015 Elsevier Inc. All rights reserved.

Higher-order nonclassicalities of finite dimensional coherent states: A comparative study

NASA Astrophysics Data System (ADS)

Alam, Nasir; Verma, Amit; Pathak, Anirban

2018-07-01

Conventional coherent states (CSs) are defined in various ways. For example, CS is defined as an infinite Poissonian expansion in Fock states, as displaced vacuum state, or as an eigenket of annihilation operator. In the infinite dimensional Hilbert space, these definitions are equivalent. However, these definitions are not equivalent for the finite dimensional systems. In this work, we present a comparative description of the lower- and higher-order nonclassical properties of the finite dimensional CSs which are also referred to as qudit CSs (QCSs). For the comparison, nonclassical properties of two types of QCSs are used: (i) nonlinear QCS produced by applying a truncated displacement operator on the vacuum and (ii) linear QCS produced by the Poissonian expansion in Fock states of the CS truncated at (d - 1)-photon Fock state. The comparison is performed using a set of nonclassicality witnesses (e.g., higher order antibunching, higher order sub-Poissonian statistics, higher order squeezing, Agarwal-Tara parameter, Klyshko's criterion) and a set of quantitative measures of nonclassicality (e.g., negativity potential, concurrence potential and anticlassicality). The higher order nonclassicality witnesses have found to reveal the existence of higher order nonclassical properties of QCS for the first time.

Sun-Direction Estimation Using a Partially Underdetermined Set of Coarse Sun Sensors

NASA Astrophysics Data System (ADS)

O'Keefe, Stephen A.; Schaub, Hanspeter

2015-09-01

A comparison of different methods to estimate the sun-direction vector using a partially underdetermined set of cosine-type coarse sun sensors (CSS), while simultaneously controlling the attitude towards a power-positive orientation, is presented. CSS are commonly used in performing power-positive sun-pointing and are attractive due to their relative inexpensiveness, small size, and reduced power consumption. For this study only CSS and rate gyro measurements are available, and the sensor configuration does not provide global triple coverage required for a unique sun-direction calculation. The methods investigated include a vector average method, a combination of least squares and minimum norm criteria, and an extended Kalman filter approach. All cases are formulated such that precise ground calibration of the CSS is not required. Despite significant biases in the state dynamics and measurement models, Monte Carlo simulations show that an extended Kalman filter approach, despite the underdetermined sensor coverage, can provide degree-level accuracy of the sun-direction vector both with and without a control algorithm running simultaneously. If no rate gyro measurements are available, and rates are partially estimated from CSS, the EKF performance degrades as expected, but is still able to achieve better than 10∘ accuracy using only CSS measurements.

Programmable hydrogels for controlled cell catch and release using hybridized aptamers and complementary sequences.

PubMed

Zhang, Zhaoyang; Chen, Niancao; Li, Shihui; Battig, Mark R; Wang, Yong

2012-09-26

The ability to regulate cell-material interactions is important in various applications such as regenerative medicine and cell separation. This study successfully demonstrates that the binding states of cells on a hydrogel surface can be programmed by using hybridized aptamers and triggering complementary sequences (CSs). In the absence of the triggering CSs, the aptamers exhibit a stable, hybridized state in the hydrogel for cell-type-specific catch. In the presence of the triggering CSs, the aptamers are transformed into a new hybridized state that leads to the rapid dissociation of the aptamers from the hydrogel. As a result, the cells are released from the hydrogel. The entire procedure of cell catch and release during the transformation of the aptamers is biocompatible and does not involve any factor destructive to either the cells or the hydrogel. Thus, the programmable hydrogel is regenerable and can be applied to a new round of cell catch and release when needed.

Characteristics of dioxin emissions at startup and shutdown of MSW incinerators.

PubMed

Tejima, Hajime; Nishigaki, Masahide; Fujita, Yasuyuki; Matsumoto, Akihiro; Takeda, Nobuo; Takaoka, Masaki

2007-01-01

Dioxin concentrations from municipal waste incinerators in Japan and elsewhere often show low concentrations that comply with legal limits (in this paper, the term "dioxin" designates WHO-TEQ: PCDD/Fs+dioxin-like PCB). However, such data is usually generated under normal steady state operational conditions, and there has been little investigation of releases occurring during startup and shutdown. It is important, therefore, to ascertain quantitatively emissions in an unsteady state (startup and shutdown) in order to correctly evaluate the relationship between emissions from a facility and the surrounding environment. The present study aimed to examine dioxin emissions of a continuously operated incinerator at startup and shutdown, and estimating the time period of greatest emission, and the processes causing dioxin generation. The startup process was divided into five stages and the shutdown into two; at each stage, dioxins in the flue gas were measured at the boiler outlet and the stack. From the concentration of dioxins and the flue gas volume at each stage, the amount of dioxins at startup and shutdown were calculated, and these were compared with that under steady state conditions. Dioxin concentration at the stack under steady state conditions was a very low level, while those at startup and shutdown were higher. In the case where dioxin concentration under a steady state is a low level like in this study, it is indicated that the total annual dioxin emission from a facility could be attributed to the startup periods.

EFFECTS OF SOG ON DPP-RECEPTOR BINDING*

PubMed Central

LOU, YUAN; NIE, QING; WAN, FREDERIC Y. M.

2007-01-01

Concentration gradients of morphogens are known to be instrumental in cell signaling and tissue patterning. Of interest here is how the presence of a competitor of BMP ligands affects cell signaling. The effects of Sog on the binding of Dpp with cell receptors are analyzed for dorsal-ventral morphogen gradient formation in vertebrate and Drosophila embryos. This prototype system includes diffusing ligands, degradation of morphogens, and cleavage of Dpp-Sog complexes by Tolloid to free up Dpp. Simple and biologically meaningful necessary and sufficient conditions for the existence of a steady state gradient configuration are established, and existence theorems are proved. For high Sog production rates (relative to the Dpp production rate), it is found that the steady state configuration exhibits a more intense Dpp-receptor concentration near the dorsal midline. Numerical simulations of the evolution of the system show that, beyond some threshold Sog production rate, the transient Dpp-receptor concentration at the dorsal midline would become more intense than that of the steady state, before subsiding and approaching a nonuniform steady state of lower magnitude. The magnitude of the transient concentration has been found to increase by several fold with increasing Sog production rate. The highly intense Dpp activity at and around the dorsal midline is consistent with available experimental observations and other analytical studies. PMID:17377624

Effect of Steady-State Faldaprevir on the Pharmacokinetics of Steady-State Methadone and Buprenorphine-Naloxone in Subjects Receiving Stable Addiction Management Therapy

PubMed Central

Joseph, David; Schobelock, Michael J.; Riesenberg, Robert R.; Vince, Bradley D.; Webster, Lynn R.; Adeniji, Abidemi; Elgadi, Mabrouk

2014-01-01

The effects of steady-state faldaprevir on the safety, pharmacokinetics, and pharmacodynamics of steady-state methadone and buprenorphine-naloxone were assessed in 34 healthy male and female subjects receiving stable addiction management therapy. Subjects continued receiving a stable oral dose of either methadone (up to a maximum dose of 180 mg per day) or buprenorphine-naloxone (up to a maximum dose of 24 mg-6 mg per day) and also received oral faldaprevir (240 mg) once daily (QD) for 8 days following a 480-mg loading dose. Serial blood samples were taken for pharmacokinetic analysis. The pharmacodynamics of the opioid maintenance regimens were evaluated by the objective and subjective opioid withdrawal scales. Coadministration of faldaprevir with methadone or buprenorphine-naloxone resulted in geometric mean ratios for the steady-state area under the concentration-time curve from 0 to 24 h (AUC0–24,ss), the steady-state maximum concentration of the drug in plasma (Cmax,ss), and the steady-state concentration of the drug in plasma at 24 h (C24,ss) of 0.92 to 1.18 for (R)-methadone, (S)-methadone, buprenorphine, norbuprenorphine, and naloxone, with 90% confidence intervals including, or very close to including, 1.00 (no effect), suggesting a limited overall effect of faldaprevir. Although individual data showed moderate variability in the exposures between subjects and treatments, there was no evidence of symptoms of opiate overdose or withdrawal either during the coadministration of faldaprevir with methadone or buprenorphine-naloxone or after faldaprevir dosing was stopped. Similar faldaprevir exposures were observed in the methadone- and buprenorphine-naloxone-treated subjects. In conclusion, faldaprevir at 240 mg QD can be coadministered with methadone or buprenorphine-naloxone without dose adjustment, although given the relatively narrow therapeutic windows of these agents, monitoring for opiate overdose and withdrawal may still be appropriate. (This study has been registered at ClinicalTrials.gov under registration no. NCT01637922.) PMID:25385094

Driver characteristics associated with child safety seat usage in Malaysia: a cross-sectional study.

PubMed

Kulanthayan, S; Razak, Ahmad; Schenk, Ellen

2010-03-01

The rapidly motorizing environment in Malaysia has made child occupant safety a current public health concern. The usage of child safety seats (CSS) is a widely regarded intervention to enhance child occupant safety, yet no study has been conducted on CSS in Malaysia. This study aims to determine the CSS usage rates in Malaysia and to assess driver characteristics that are associated with CSS usage. Nine variables - urban versus rural study location, age, gender, marital status, educational status, monthly family income, number of children present in the vehicle, distance traveled to the study location, and attitude - were examined through a cross-sectional study of interviewing drivers of 230 vehicles transporting at least one child <10 years of age at the time of the study. The vehicles were also observed for whether or not there was a CSS present. The interviews were conducted at six sampling locations - three urban and three rural - in the state of Melaka. 27.4% of the drivers were found to be using at least one CSS at the time of the survey. Among the nine variables studied, three of the driver characteristics showed statistical significance (p<0.05) with CSS usage: age (p=0.047), educational status (p=0.009), and attitude (p=0.009). This study begins to create knowledge on child occupant safety in Malaysia. The results indicate that interventional efforts should focus on educational programs geared toward drivers that are less educated or extended family members who inconsistently transport young children. Furthermore, any educational efforts could be strongly enhanced by legislation mandating the use of CSS. Every effort should be made to thoroughly assess the effectiveness of any educational or legislative activities that are implemented. Copyright 2009 Elsevier Ltd. All rights reserved.

SAMPLING DURATION DEPENDENCE OF SEMI-CONTINUOUS ORGANIC CARBON MEASUREMENTS ON STEADY STATE SECONDARY ORGANIC AEROSOLS

EPA Science Inventory

Semi-continuous organic carbon concentrations were measured through several experiments of statically generated secondary organic aerosol formed by hydrocarbon + NOx irradiations. Repeated, randomized measurements of these steady state aerosols reveal decreases in the observed c...

A mathematical model of liver metabolism: from steady state to dynamic

NASA Astrophysics Data System (ADS)

Calvetti, D.; Kuceyeski, A.; Somersalo, E.

2008-07-01

The increase in Type 2 diabetes and other metabolic disorders has led to an intense focus on the areas of research related to metabolism. Because the liver is essential in regulating metabolite concentrations that maintain life, it is especially important to have good knowledge of the functions within this organ. In silico mathematical models that can adequately describe metabolite concentrations, flux and transport rates in the liver in vivo can be a useful predictive tool. Fully dynamic models, which contain expressions for Michaelis-Menten reaction kinetics can be utilized to investigate different metabolic states, for example exercise, fed or starved state. In this paper we describe a two compartment (blood and tissue) spatially lumped liver metabolism model. First, we use Bayesian Flux Balance Analysis (BFBA) to estimate the values of flux and transport rates at steady state, which agree closely with values from the literature. These values are then used to find a set of Michaelis-Menten parameters and initial concentrations which identify a dynamic model that can be used for exploring different metabolic states. In particular, we investigate the effect of doubling the concentration of lactate entering the system via the hepatic artery and portal vein. This change in lactate concentration forces the system to a new steady state, where glucose production is increased.

Discreteness-induced concentration inversion in mesoscopic chemical systems.

PubMed

Ramaswamy, Rajesh; González-Segredo, Nélido; Sbalzarini, Ivo F; Grima, Ramon

2012-04-10

Molecular discreteness is apparent in small-volume chemical systems, such as biological cells, leading to stochastic kinetics. Here we present a theoretical framework to understand the effects of discreteness on the steady state of a monostable chemical reaction network. We consider independent realizations of the same chemical system in compartments of different volumes. Rate equations ignore molecular discreteness and predict the same average steady-state concentrations in all compartments. However, our theory predicts that the average steady state of the system varies with volume: if a species is more abundant than another for large volumes, then the reverse occurs for volumes below a critical value, leading to a concentration inversion effect. The addition of extrinsic noise increases the size of the critical volume. We theoretically predict the critical volumes and verify, by exact stochastic simulations, that rate equations are qualitatively incorrect in sub-critical volumes.

Steady-state kinetic modeling constrains cellular resting states and dynamic behavior.

PubMed

Purvis, Jeremy E; Radhakrishnan, Ravi; Diamond, Scott L

2009-03-01

A defining characteristic of living cells is the ability to respond dynamically to external stimuli while maintaining homeostasis under resting conditions. Capturing both of these features in a single kinetic model is difficult because the model must be able to reproduce both behaviors using the same set of molecular components. Here, we show how combining small, well-defined steady-state networks provides an efficient means of constructing large-scale kinetic models that exhibit realistic resting and dynamic behaviors. By requiring each kinetic module to be homeostatic (at steady state under resting conditions), the method proceeds by (i) computing steady-state solutions to a system of ordinary differential equations for each module, (ii) applying principal component analysis to each set of solutions to capture the steady-state solution space of each module network, and (iii) combining optimal search directions from all modules to form a global steady-state space that is searched for accurate simulation of the time-dependent behavior of the whole system upon perturbation. Importantly, this stepwise approach retains the nonlinear rate expressions that govern each reaction in the system and enforces constraints on the range of allowable concentration states for the full-scale model. These constraints not only reduce the computational cost of fitting experimental time-series data but can also provide insight into limitations on system concentrations and architecture. To demonstrate application of the method, we show how small kinetic perturbations in a modular model of platelet P2Y(1) signaling can cause widespread compensatory effects on cellular resting states.

Integration of plume and puff diffusion models/application of CFD

NASA Astrophysics Data System (ADS)

Mori, Akira

The clinical symptoms of patients and other evidences of a gas poisoning accident inside an industrial building strongly suggested an abrupt influx of engine exhaust from a construction vehicle which was operating outside in the open air. But the obviously high level of gas concentration could not be well explained by any conventional steady-state gas diffusion models. The author used an unsteady-state continuous Puff Model to simulate the time-wise changes in air stream with the pollutant gas being continuously emitted, and successfully reproduced the observed phenomena. The author demonstrates that this diffusion formula can be solved analytically by the use of error function as long as the change in wind velocity is stepwise, and clarifies the accurate differences between the unsteady- and steady-states and their convergence profiles. Also, the relationship between the Puff and Plume Models is discussed. The case study included a computational fluid dynamics (CFD) analysis to estimate the steady-state air stream and the gas concentration pattern in the affected area. It is well known that clear definition of the boundary conditions is key to successful CFD analysis. The author describes a two-step use of CFD: the first step to define the boundary conditions and the second to determine the steady-state air stream and the gas concentration pattern.

Pharmacokinetic Variability of Drugs Used for Prophylactic Treatment of Migraine.

PubMed

Tfelt-Hansen, Peer; Ågesen, Frederik Nybye; Pavbro, Agniezka; Tfelt-Hansen, Jacob

2017-05-01

In this review, we evaluate the variability in the pharmacokinetics of 11 drugs with established prophylactic effects in migraine to facilitate 'personalized medicine' with these drugs. PubMed was searched for 'single-dose' and 'steady-state' pharmacokinetic studies of these 11 drugs. The maximum plasma concentration was reported in 248 single-dose and 115 steady-state pharmacokinetic studies, and the area under the plasma concentration-time curve was reported in 299 single-dose studies and 112 steady-state pharmacokinetic studies. For each study, the coefficient of variation was calculated for maximum plasma concentration and area under the plasma concentration-time curve, and we divided the drug variability into two categories; high variability, coefficient of variation >40%, or low or moderate variability, coefficient of variation <40%. Based on the area under the plasma concentration-time curve in steady-state studies, the following drugs have high pharmacokinetic variability: propranolol in 92% (33/36), metoprolol in 85% (33/39), and amitriptyline in 60% (3/5) of studies. The following drugs have low or moderate variability: atenolol in 100% (2/2), valproate in 100% (15/15), topiramate in 88% (7/8), and naproxen and candesartan in 100% (2/2) of studies. For drugs with low or moderate pharmacokinetic variability, treatment can start without initial titration of doses, whereas titration is used to possibly enhance tolerability of topiramate and amitriptyline. The very high pharmacokinetic variability of metoprolol and propranolol can result in very high plasma concentrations in a small minority of patients, and those drugs should therefore be titrated up from a low initial dose, depending mainly on the occurrence of adverse events.

Pharmacokinetics of buprenorphine: a comparison of sublingual tablet versus liquid after chronic dosing.

PubMed

Compton, Peggy; Ling, Walter; Chiang, C Nora; Moody, David E; Huber, Alice; Ling, Debbie; Charuvastra, Charles

2007-06-01

Although buprenorphine is approved for use in the outpatient treatment of opioid addiction in 2 tablet formulations, a monoproduct containing buprenorphine only (Subutex) and a buprenorphine/naloxone combination product (Suboxone), much of the clinical data that support the approval by the U.S. Food and Drug Administration were generated by using a sublingual liquid. To interpret the literature in prescribing parameters for tablet buprenorphine, this study was designed to determine steady state buprenorphine plasma levels for the 2 formulations and to assess the relative bioavailability of each. A randomized, double-blind, crossover study with dose increases was conducted during a 12-week period at an outpatient treatment clinic. Of the 184 subjects initially randomized to treatment, 133 (72.3%) were evaluated for the steady-state trough plasma concentration, 16 (8.7%) for relative bioavailability, and 31 (16.8%) for dose proportionality. At steady state, differences in the trough plasma concentrations of buprenorphine between the 2 formulations were found across all the dose levels. Average plasma concentration (Cavg) of the tablet at twice the milligram dose of the liquid was twice that of the liquid; intersubject variability was greater for the tablet. At double the dose of tablet, there is no difference in steady state plasma concentrations. The bioavailability seems equivalent for the 2 formulations across all the dose levels.

Single-dose and steady-state pharmacokinetics of tenofovir disoproxil fumarate in human immunodeficiency virus-infected children.

PubMed

Hazra, Rohan; Balis, Frank M; Tullio, Antonella N; DeCarlo, Ellen; Worrell, Carol J; Steinberg, Seth M; Flaherty, John F; Yale, Kitty; Poblenz, Marianne; Kearney, Brian P; Zhong, Lijie; Coakley, Dion F; Blanche, Stephane; Bresson, Jean Louis; Zuckerman, Judith A; Zeichner, Steven L

2004-01-01

Tenofovir disoproxil fumarate (DF) is a potent nucleotide analog reverse transcriptase inhibitor approved for the treatment of human immunodeficiency virus (HIV)-infected adults. The single-dose and steady-state pharmacokinetics of tenofovir were evaluated following administration of tenofovir DF in treatment-experienced HIV-infected children requiring a change in antiretroviral therapy. Using increments of tenofovir DF 75-mg tablets, the target dose was 175 mg/m(2); the median administered dose was 208 mg/m(2). Single-dose pharmacokinetics were evaluated in 18 subjects, and the geometric mean area under the concentration-time curve from 0 h to infinity (AUC(0- infinity )) was 2,150 ng. h/ml and the geometric mean maximum concentration (C(max)) was 266 ng/ml. Subsequently, other antiretrovirals were added to each patient's regimen based upon treatment history and baseline viral resistance results. Steady-state pharmacokinetics were evaluated in 16 subjects at week 4. The steady-state, geometric mean AUC for the 24-h dosing interval was 2,920 ng. h/ml and was significantly higher than the AUC(0- infinity ) after the first dose (P = 0.0004). The geometric mean C(max) at steady state was 302 ng/ml. Tenofovir DF was generally very well tolerated. Steady-state tenofovir exposures in children receiving tenofovir DF-containing combination antiretroviral therapy approached values seen in HIV-infected adults (AUC, approximately 3,000 ng. h/ml; C(max), approximately 300 ng/ml) treated with tenofovir DF at 300 mg.

Heavier alkali-metal monosulfides (KS, RbS, CsS, and FrS) and their cations.

PubMed

Lee, Edmond P F; Wright, Timothy G

2005-10-08

The heavier alkali-metal monosulfides (KS, RbS, CsS, and FrS) have been studied by high-level ab initio calculations. The RCCSD(T) method has been employed, combined with large flexible valence basis sets. All-electron basis sets are used for potassium and sulfur, with effective core potentials being used for the other metals, describing the core electrons. Potential-energy curves are calculated for the lowest two neutral and cationic states: all neutral monosulfide species have a (2)Pi ground state, in contrast with the alkali-metal monoxide species, which undergo a change in the electronic ground state from (2)Pi to (2)Sigma(+) as the group is descended. In the cases of KS, RbS, and CsS, spin-orbit curves are also calculated. We also calculate potential-energy curves for the lowest (3)Sigma(-) and (3)Pi states of the cations. From the potential-energy curves, spectroscopic constants are derived, and for KS the spectroscopic results are compared to experimental spectroscopic values. Ionization energies, dissociation energies, and heats of formation are also calculated; for KS, we explore the effects of relativity and basis set extrapolation on these values.

Evaluating the Relationship between Vancomycin Trough Concentration and 24-Hour Area under the Concentration-Time Curve in Neonates.

PubMed

Tseng, Sheng-Hsuan; Lim, Chuan Poh; Chen, Qi; Tang, Cheng Cai; Kong, Sing Teang; Ho, Paul Chi-Lui

2018-04-01

Bacterial sepsis is a major cause of morbidity and mortality in neonates, especially those involving methicillin-resistant Staphylococcus aureus (MRSA). Guidelines by the Infectious Diseases Society of America recommend the vancomycin 24-h area under the concentration-time curve to MIC ratio (AUC 24 /MIC) of >400 as the best predictor of successful treatment against MRSA infections when the MIC is ≤1 mg/liter. The relationship between steady-state vancomycin trough concentrations and AUC 24 values (mg·h/liter) has not been studied in an Asian neonatal population. We conducted a retrospective chart review in Singapore hospitals and collected patient characteristics and therapeutic drug monitoring data from neonates on vancomycin therapy over a 5-year period. A one-compartment population pharmacokinetic model was built from the collected data, internally validated, and then used to assess the relationship between steady-state trough concentrations and AUC 24 A Monte Carlo simulation sensitivity analysis was also conducted. A total of 76 neonates with 429 vancomycin concentrations were included for analysis. Median (interquartile range) was 30 weeks (28 to 36 weeks) for postmenstrual age (PMA) and 1,043 g (811 to 1,919 g) for weight at the initiation of treatment. Vancomycin clearance was predicted by weight, PMA, and serum creatinine. For MRSA isolates with a vancomycin MIC of ≤1, our major finding was that the minimum steady-state trough concentration range predictive of achieving an AUC 24 /MIC of >400 was 8 to 8.9 mg/liter. Steady-state troughs within 15 to 20 mg/liter are unlikely to be necessary to achieve an AUC 24 /MIC of >400, whereas troughs within 10 to 14.9 mg/liter may be more appropriate. Copyright © 2018 American Society for Microbiology.

Preparation of chondroitin sulfate libraries containing disulfated disaccharide units and inhibition of thrombin by these chondroitin sulfates.

PubMed

Numakura, Mario; Kusakabe, Noriko; Ishige, Kazuya; Ohtake-Niimi, Shiori; Habuchi, Hiroko; Habuchi, Osami

2010-07-01

Chondroitin sulfate (CS) containing GlcA-GalNAc(4,6-SO(4)) (E unit) and CS containing GlcA(2SO(4))-GalNAc(6SO(4)) (D unit) have been implicated in various physiological functions. However, it has been poorly understood how the structure and contents of disulfated disaccharide units in CS contribute to these functions. We prepared CS libraries containing E unit or D unit in various proportions by in vitro enzymatic reactions using recombinant GalNAc 4-sulfate 6-O-sulfotransferase and uronosyl 2-O-sulfotransferase, and examined their inhibitory activity toward thrombin. The in vitro sulfated CSs containing disulfated disaccharide units showed concentration-dependent direct inhibition of thrombin when the proportion of E unit or D unit in the CSs was above 15-17%. The CSs containing both E unit and D unit exhibited higher inhibitory activity toward thrombin than the CSs containing either E unit or D unit alone, if the proportion of the total disulfated disaccharide units of these CSs was comparable. The thrombin-catalyzed degradation of fibrinogen, a physiological substrate for thrombin, was also inhibited by the CS containing both E unit and D unit. These observations indicate that the enzymatically prepared CS libraries containing various amounts of disulfated disaccharide units appear to be useful for elucidating the physiological function of disulfated disaccharide units in CS.

Mapping the Interaction Site for a β-Scorpion Toxin in the Pore Module of Domain III of Voltage-gated Na+ Channels*

PubMed Central

Zhang, Joel Z.; Yarov-Yarovoy, Vladimir; Scheuer, Todd; Karbat, Izhar; Cohen, Lior; Gordon, Dalia; Gurevitz, Michael; Catterall, William A.

2012-01-01

Activation of voltage-gated sodium (Nav) channels initiates and propagates action potentials in electrically excitable cells. β-Scorpion toxins, including toxin IV from Centruroides suffusus suffusus (CssIV), enhance activation of NaV channels. CssIV stabilizes the voltage sensor in domain II in its activated state via a voltage-sensor trapping mechanism. Amino acid residues required for the action of CssIV have been identified in the S1-S2 and S3-S4 extracellular loops of domain II. The extracellular loops of domain III are also involved in toxin action, but individual amino acid residues have not been identified. We used site-directed mutagenesis and voltage clamp recording to investigate amino acid residues of domain III that are involved in CssIV action. In the IIISS2-S6 loop, five substitutions at four positions altered voltage-sensor trapping by CssIVE15A. Three substitutions (E1438A, D1445A, and D1445Y) markedly decreased voltage-sensor trapping, whereas the other two substitutions (N1436G and L1439A) increased voltage-sensor trapping. These bidirectional effects suggest that residues in IIISS2-S6 make both positive and negative interactions with CssIV. N1436G enhanced voltage-sensor trapping via increased binding affinity to the resting state, whereas L1439A increased voltage-sensor trapping efficacy. Based on these results, a three-dimensional model of the toxin-channel interaction was developed using the Rosetta modeling method. These data provide additional molecular insight into the voltage-sensor trapping mechanism of toxin action and define a three-point interaction site for β-scorpion toxins on NaV channels. Binding of α- and β-scorpion toxins to two distinct, pseudo-symmetrically organized receptor sites on NaV channels acts synergistically to modify channel gating and paralyze prey. PMID:22761417

Estimating Systemic Exposure to Levonorgestrel from an Oral Contraceptive

PubMed Central

Basaraba, Cale N; Westhoff, Carolyn L; Pike, Malcolm C; Nandakumar, Renu; Cremers, Serge

2017-01-01

Objective The gold standard for measuring oral contraceptive (OC) pharmacokinetics is the 24-hour steady-state area-under-the-curve (AUC). We conducted this study to assess whether limited sampling at steady state or measurements following use of one or two OCs could provide an adequate proxy in epidemiological studies for the progestin 24-hour steady-state AUC of a particular OC. Study Design We conducted a 13-sample, 24-hour pharmacokinetic study on both day 1 and day 21 of the first cycle of a monophasic OC containing 30 μg ethinyl estradiol and 150 μg levonorgestrel (LNG) in 17 normal-weight healthy white women, and a single-dose 9-sample study of the same OC after a one-month washout. We compared the 13-sample steady-state results with several steady-state and single-dose results calculated using parsimonious sampling schemes. Results The 13-sample steady-state 24-hour LNG AUC was highly correlated with the steady-state 24-hour trough value (r = 0.95; 95% CI [0.85, 0.98]) and with the steady-state 6, 8, 12 and 16-hour values (0.92 ≤ r ≤ 0.95). The trough values after one or two doses were moderately correlated with the steady-state 24-hour AUC value (r = 0.70; 95% CI [0.27, 0.90] and 0.77; 95% CI [0.40, 0.92], respectively). Conclusions Single time-point concentrations at steady-state and after administration of one or two OCs gave highly to moderately correlated estimates of steady-state LNG AUC. Using such measures could facilitate prospective pharmaco-epidemiologic studies of the OC and its side effects. PMID:28041990

The steady-state and transient electron transport within bulk zinc-blende indium nitride: The impact of crystal temperature and doping concentration variations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Siddiqua, Poppy; O'Leary, Stephen K., E-mail: stephen.oleary@ubc.ca

2016-03-07

Within the framework of a semi-classical three-valley Monte Carlo electron transport simulation approach, we analyze the steady-state and transient aspects of the electron transport within bulk zinc-blende indium nitride, with a focus on the response to variations in the crystal temperature and the doping concentration. We find that while the electron transport associated with zinc-blende InN is highly sensitive to the crystal temperature, it is not very sensitive to the doping concentration selection. The device consequences of these results are then explored.

Measurement of steady-state minority-carrier transport parameters in heavily doped n-type silicon

NASA Technical Reports Server (NTRS)

Del Alamo, Jesus A.; Swanson, Richard M.

1987-01-01

The relevant hole transport and recombination parameters in heavily doped n-type silicon under steady state are the hole diffusion length and the product of the hole diffusion coefficient times the hole equilibrium concentration. These parameters have measured in phosphorus-doped silicon grown by epitaxy throughout nearly two orders of magnitude of doping level. Both parameters are found to be strong functions of donor concentration. The equilibrium hole concentration can be deduced from the measurement. A rigid shrinkage of the forbidden gap appears as the dominant heavy doping mechanism in phosphorus-doped silicon.

Steady-state protein focusing in carrier ampholyte based isoelectric focusing: Part I-Analytical solution.

PubMed

Shim, Jaesool; Yoo, Kisoo; Dutta, Prashanta

2017-03-01

The determination of an analytical solution to find the steady-state protein concentration distribution in IEF is very challenging due to the nonlinear coupling between mass and charge conservation equations. In this study, approximate analytical solutions are obtained for steady-state protein distribution in carrier ampholyte based IEF. Similar to the work of Svensson, the final concentration profile for proteins is assumed to be Gaussian, but appropriate expressions are presented in order to obtain the effective electric field and pH gradient in the focused protein band region. Analytical results are found from iterative solutions of a system of coupled algebraic equations using only several iterations for IEF separation of three plasma proteins: albumin, cardiac troponin I, and hemoglobin. The analytical results are compared with numerically predicted results for IEF, showing excellent agreement. Analytically obtained electric field and ionic conductivity distributions show significant deviation from their nominal values, which is essential in finding the protein focusing behavior at isoelectric points. These analytical solutions can be used to determine steady-state protein concentration distribution for experiment design of IEF considering any number of proteins and ampholytes. Moreover, the model presented herein can be used to find the conductivity, electric field, and pH field. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Bipolar pulse field for magnetic refrigeration

DOEpatents

Lubell, Martin S.

1994-01-01

A magnetic refrigeration apparatus includes first and second steady state magnets, each having a field of substantially equal strength and opposite polarity, first and second bodies made of magnetocaloric material disposed respectively in the influence of the fields of the first and second steady state magnets, and a pulsed magnet, concentric with the first and second steady state magnets, and having a field which cycles between the fields of the first and second steady state magnets, thereby cyclically magnetizing and demagnetizing and thus heating and cooling the first and second bodies. Heat exchange apparatus of suitable design can be used to expose a working fluid to the first and second bodies of magnetocaloric material. A controller is provided to synchronize the flow of working fluid with the changing states of magnetization of the first and second bodies.

Influence of feeding alternative fiber sources on the gastrointestinal fermentation, digestive enzyme activities and mucosa morphology of growing Greylag geese.

PubMed

He, L W; Meng, Q X; Li, D Y; Zhang, Y W; Ren, L P

2015-10-01

The objective of this trial was to study the influence of dietary fiber sources on the gastrointestinal fermentation, digestive enzyme activity, and mucosa morphology of growing Greylag geese. In total, 240 Greylag geese (28-day-old) were allocated to 4 treatments (15 pens/treatment) differing in dietary fiber source: corn straw silage (CSS group), steam-exploded corn straw (SECS group), steam-exploded wheat straw (SEWS group), or steam-exploded rice straw (SERS group). At 112 days of age, 15 birds per group were euthanized to collect samples. No difference (P > 0.05) was found on all the gastrointestinal pH values and ammonia-nitrogen concentrations between the groups. The CSS and SERS groups had a lower (P < 0.05) proportion of acetic acid in the gizzard than the SECS and SEWS groups. The CSS group had a higher VFA concentration in the jejunum (P < 0.05) and acetic acid proportion (P < 0.01) in the ceca, and a lower (P < 0.01) butyric acid proportion than the other groups except for the SECS group. The SECS group had a higher (P < 0.01) acetic acid proportion and lower (P < 0.05) proportions of propionic acid and valeric acid in the ceca than the SEWS and SERS groups. Different fiber sources resulted in different VFA profiles, especially in the gizzard and ceca. Almost all gastrointestinal protease activities of the CSS group were higher (P < 0.05) than the other groups, along with lower (P < 0.01) amylase activities in the duodenum, jejunum, ileum, and ceca. Lipase activity in proventriculus was highest (P < 0.01) in the SEWS group and its cecal activity was lower (P < 0.01) in the SECS and SEWS groups than the CSS and SERS groups with a higher (P < 0.01) lipase activity in the CSS group than the SERS group. The SECS and SERS groups had a higher cellulase activity in the ceca than the CSS and SEWS groups, with a higher (P < 0.01) rectal cellulase activity in the SERS group than the other groups. There was no significant effect (P > 0.05) on the intestinal mucosa morphology. These results suggest that corn straw silage improves protein digestion while steam-exploded straw provides more energy. © 2015 Poultry Science Association Inc.

Interplay between ABA and phospholipases A(2) and D in the response of citrus fruit to postharvest dehydration.

PubMed

Romero, Paco; Gandía, Mónica; Alférez, Fernando

2013-09-01

The interplay between abscisic acid (ABA) and phospholipases A2 and D (PLA2 and PLD) in the response of citrus fruit to water stress was investigated during postharvest by using an ABA-deficient mutant from 'Navelate' orange named 'Pinalate'. Fruit from both varieties harvested at two different maturation stages (mature-green and full-mature) were subjected to prolonged water loss inducing stem-end rind breakdown (SERB) in full-mature fruit. Treatment with PLA2 inhibitor aristolochic acid (AT) and PLD inhibitor lysophosphatidylethanolamine (LPE) reduced the disorder in both varieties, suggesting that phospholipid metabolism is involved in citrus peel quality. Expression of CsPLDα and CsPLDβ, and CssPLA2α and CssPLA2β was studied by real-time RT-PCR during water stress and in response to ABA. CsPLDα expression increased in mature-green fruit from 'Navelate' but not in 'Pinalate' and ABA did not counteract this effect. ABA enhanced repression of CsPLDα in full-mature fruit. CsPLDβ gene expression decreased in mature-green 'Pinalate', remained unchanged in 'Navelate' and was induced in full-mature fruit from both varieties. CssPLA2α expression increased in mature-green fruit from both varieties whereas in full-mature fruit only increased in 'Navelate'. CssPLA2β expression increased in mature-green flavedo from both varieties, but in full-mature fruit remained steady in 'Navelate' and barely increased in 'Pinalate' fruit. ABA reduced expression in both after prolonged storage. Responsiveness to ABA increased with maturation. Our results show interplay between PLA2 and PLD and suggest that ABA action is upstream phospholipase activation. Response to ABA during water stress in citrus is regulated during fruit maturation and involves membrane phospholipid degradation. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Development of Non-Toxic Quantum Dots for Flexible Display Applications

DTIC Science & Technology

2013-11-14

of these organically passivated core NCs typically exhibit surface related trap states acting as fast non-radiative de -excitation channels for...CSS) structures. These CS or CSS d-dots are planned to surface passivation with inorganic metal-free ligands for efficient electron-hole injection...1998, 281, 2013. (2) Chan, W.; Nie, S. Science 1998, 281, 2016. (3) Kim, S.; Lim, Y. T.; Soltesz, E. G.; De Grand, A. M.; Lee, J.; Nakayama, A

Process evaluation of enzymatic hydrolysis with filtrate recycle for the production of high concentration sugars.

PubMed

Xue, Ying; Rusli, Jannov; Chang, Hou-Min; Phillips, Richard; Jameel, Hasan

2012-02-01

Process simulation and lab trials were carried out to demonstrate and confirm the efficiency of the concept that recycling hydrolysate at low total solid enzymatic hydrolysis is one of the options to increase the sugar concentration without mixing problems. Higher sugar concentration can reduce the capital cost for fermentation and distillation because of smaller retention volume. Meanwhile, operation cost will also decrease for less operating volume and less energy required for distillation. With the computer simulation, time and efforts can be saved to achieve the steady state of recycling process, which is the scenario for industrial production. This paper, to the best of our knowledge, is the first paper discussing steady-state saccharification with recycling of the filtrate form enzymatic hydrolysis to increase sugar concentration. Recycled enzymes in the filtrate (15-30% of the original enzyme loading) resulted in 5-10% higher carbohydrate conversion compared to the case in which recycled enzymes were denatured. The recycled hydrolysate yielded 10% higher carbohydrate conversion compared to pure sugar simulated hydrolysate at the same enzyme loading, which indicated hydrolysis by-products could boost enzymatic hydrolysis. The high sugar concentration (pure sugar simulated) showed inhibition effect, since about 15% decrease in carbohydrate conversion was observed compared with the case with no sugar added. The overall effect of hydrolysate recycling at WinGEMS simulated steady-state conditions with 5% total solids was increasing the sugar concentration from 35 to 141 g/l, while the carbohydrate conversion was 2% higher for recycling at steady state (87%) compared with no recycling strategy (85%). Ten percent and 15% total solid processes were also evaluated in this study.

Simultaneous measurement of glucose transport and utilization in the human brain

PubMed Central

Shestov, Alexander A.; Emir, Uzay E.; Kumar, Anjali; Henry, Pierre-Gilles; Seaquist, Elizabeth R.

2011-01-01

Glucose is the primary fuel for brain function, and determining the kinetics of cerebral glucose transport and utilization is critical for quantifying cerebral energy metabolism. The kinetic parameters of cerebral glucose transport, KMt and Vmaxt, in humans have so far been obtained by measuring steady-state brain glucose levels by proton (1H) NMR as a function of plasma glucose levels and fitting steady-state models to these data. Extraction of the kinetic parameters for cerebral glucose transport necessitated assuming a constant cerebral metabolic rate of glucose (CMRglc) obtained from other tracer studies, such as 13C NMR. Here we present new methodology to simultaneously obtain kinetic parameters for glucose transport and utilization in the human brain by fitting both dynamic and steady-state 1H NMR data with a reversible, non-steady-state Michaelis-Menten model. Dynamic data were obtained by measuring brain and plasma glucose time courses during glucose infusions to raise and maintain plasma concentration at ∼17 mmol/l for ∼2 h in five healthy volunteers. Steady-state brain vs. plasma glucose concentrations were taken from literature and the steady-state portions of data from the five volunteers. In addition to providing simultaneous measurements of glucose transport and utilization and obviating assumptions for constant CMRglc, this methodology does not necessitate infusions of expensive or radioactive tracers. Using this new methodology, we found that the maximum transport capacity for glucose through the blood-brain barrier was nearly twofold higher than maximum cerebral glucose utilization. The glucose transport and utilization parameters were consistent with previously published values for human brain. PMID:21791622

Models for nearly every occasion: Part III - One box decreasing emission models.

PubMed

Hewett, Paul; Ganser, Gary H

2017-11-01

New one box "well-mixed room" decreasing emission (DE) models are introduced that allow for local exhaust or local exhaust with filtered return, as well the recirculation of a filtered (or cleaned) portion of the general room ventilation. For each control device scenario, a steady state and transient model is presented. The transient equations predict the concentration at any time t after the application of a known mass of a volatile substance to a surface, and can be used to predict the task exposure profile, the average task exposure, as well as peak and short-term exposures. The steady state equations can be used to predict the "average concentration per application" that is reached whenever the substance is repeatedly applied. Whenever the beginning and end concentrations are expected to be zero (or near zero) the steady state equations can also be used to predict the average concentration for a single task with multiple applications during the task, or even a series of such tasks. The transient equations should be used whenever these criteria cannot be met. A structured calibration procedure is proposed that utilizes a mass balance approach. Depending upon the DE model selected, one or more calibration measurements are collected. Using rearranged versions of the steady state equations, estimates of the model variables-e.g., the mass of the substance applied during each application, local exhaust capture efficiency, and the various cleaning or filtration efficiencies-can be calculated. A new procedure is proposed for estimating the emission rate constant.

Virus transport during infiltration of a wetting front into initially unsaturated sand columns.

PubMed

Kenst, Andrew B; Perfect, Edmund; Wilhelm, Steven W; Zhuang, Jie; McCarthy, John F; McKay, Larry D

2008-02-15

We investigated the effect of different flow conditions on the transport of bacteriophage phiX174 in Memphis aquifer sand. Virus transport associated with a wetting front moving into an initially unsaturated horizontal sand column was experimentally compared with that observed under steady-state saturated vertical flow. Results obtained by sectioning the sand columns showthattotal (retained and free) resident virus concentrations decreased approximately exponentially with the travel distance. The rate of decline was similar under both transient unsaturated flow and steady-state saturated flow conditions. Total resident virus concentrations near the inlet were an order of magnitude greater than the virus concentration of the influent solution in both experiments, indicating continuous virus sorption during flow through this zone. Virus retardation was quantified using the ratio of the centroids of the relative saturation and virus concentration versus relative distance functions. The mean retardation factors were 6.43 (coefficient of variation, CV = 14.4%) and 8.22 (CV = 8.22%) for the transient unsaturated and steady-state saturated flow experiments, respectively. Attest indicated no significant difference between these values at P < 0.05. Air-water and air-water-solid interfaces are thought to enhance virus inactivation and sorption to solid particles. The similar retardation factors obtained may be attributable to the reduced presence of these interfaces in the two flow systems investigated as compared to steady-state unsaturated flow experiments in which these interfaces occur throughout the entire column.

Effects of Renal Impairment on Steady-State Plasma Concentrations of Rivastigmine: A Population Pharmacokinetic Analysis of Capsule and Patch Formulations in Patients with Alzheimer's Disease.

PubMed

Lefèvre, Gilbert; Callegari, Francesca; Gsteiger, Sandro; Xiong, Yuan

2016-10-01

The glomerular filtration rate (GFR), a measure of renal function, decreases by approximately 10 mL/min every 10 years after the age of 40 years, which could lead to the accumulation of drugs and/or renal toxicity. Pharmacokinetic studies of drugs excreted both renally and non-renally are desirable in patients with impaired renal function, defined by parameters including estimated GFR (eGFR) and creatinine clearance (CL CR ). We describe here a population pharmacokinetic analysis of the possible effects of renal impairment on steady-state plasma concentrations of rivastigmine and its metabolite NAP226-90 after rivastigmine patch (5 cm 2 [4.6 mg/24 h], 10 cm 2 [9.5 mg/24 h], 15 cm 2 [13.3 mg/24 h], and 20 cm 2 [17.4 mg/24 h]) and capsule (1.5, 3, 4.5, and 6 mg/12 h) treatment in patients with Alzheimer's disease. The data used to conduct the current pharmacokinetic analysis were obtained from the pivotal phase III, 24-week, multicenter, randomized, double-blind, placebo- and active-controlled, parallel-group study (IDEAL). One blood sample was collected from each patient at steady-state to measure plasma concentrations of rivastigmine and NAP226-90 using a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. The steady-state plasma concentrations of rivastigmine and NAP226-90 were plotted against CL CR and eGFR data, and boxplots were constructed after stratification by renal function. The two groups (mild/no renal impairment vs. moderate/severe/end-stage renal impairment) showed comparable demographic covariates for all patch sizes and capsule doses. No correlation was observed between CL CR or eGFR and plasma concentrations of rivastigmine or NAP226-90. Boxplots of concentrations of rivastigmine or NAP226-90 for each dose largely overlapped for patch and capsule. Additionally, model-based estimates of plasma concentrations adjusted for body weight yielded similar results. The results of this study show that renal function does not affect rivastigmine or NAP226-90 steady-state plasma concentrations, and no dose adjustment in patients with renal impairment is required. CLINICALTRIALS.GOV: NCT00099242.

Bipolar pulse field for magnetic refrigeration

DOEpatents

Lubell, M.S.

1994-10-25

A magnetic refrigeration apparatus includes first and second steady state magnets, each having a field of substantially equal strength and opposite polarity, first and second bodies made of magnetocaloric material disposed respectively in the influence of the fields of the first and second steady state magnets, and a pulsed magnet, concentric with the first and second steady state magnets, and having a field which cycles between the fields of the first and second steady state magnets, thereby cyclically magnetizing and demagnetizing and thus heating and cooling the first and second bodies. Heat exchange apparatus of suitable design can be used to expose a working fluid to the first and second bodies of magnetocaloric material. A controller is provided to synchronize the flow of working fluid with the changing states of magnetization of the first and second bodies. 2 figs.

Metronidazole and hydroxymetronidazole central nervous system distribution: 1. microdialysis assessment of brain extracellular fluid concentrations in patients with acute brain injury.

PubMed

Frasca, Denis; Dahyot-Fizelier, Claire; Adier, Christophe; Mimoz, Olivier; Debaene, Bertrand; Couet, William; Marchand, Sandrine

2014-01-01

The distribution of metronidazole in the central nervous system has only been described based on cerebrospinal fluid data. However, extracellular fluid (ECF) concentrations may better predict its antimicrobial effect and/or side effects. We sought to explore by microdialysis brain ECF metronidazole distribution in patients with acute brain injury. Four brain-injured patients monitored by cerebral microdialysis received 500 mg of metronidazole over 0.5 h every 8 h. Brain dialysates and blood samples were collected at steady state over 8 h. Probe recoveries were evaluated by in vivo retrodialysis in each patient for metronidazole. Metronidazole and OH-metronidazole were assayed by high-pressure liquid chromatography, and a noncompartmental pharmacokinetic analysis was performed. Probe recovery was equal to 78.8% ± 1.3% for metronidazole in patients. Unbound brain metronidazole concentration-time curves were delayed compared to unbound plasma concentration-time curves but with a mean metronidazole unbound brain/plasma AUC0-τ ratio equal to 102% ± 19% (ranging from 87 to 124%). The unbound plasma concentration-time profiles for OH-metronidazole were flat, with mean average steady-state concentrations equal to 4.0 ± 0.7 μg ml(-1). This microdialysis study describes the steady-state brain distribution of metronidazole in patients and confirms its extensive distribution.

Early life social stress and resting state functional connectivity in postpartum rat anterior cingulate circuits.

PubMed

Nephew, Benjamin C; Febo, Marcelo; Huang, Wei; Colon-Perez, Luis M; Payne, Laurellee; Poirier, Guillaume L; Greene, Owen; King, Jean A

2018-03-15

Continued development and refinement of resting state functional connectivity (RSFC) fMRI techniques in both animal and clinical studies has enhanced our comprehension of the adverse effects of stress on psychiatric health. The objective of the current study was to assess both maternal behavior and resting state functional connectivity (RSFC) changes in these animals when they were dams caring for their own young. It was hypothesized that ECSS exposed dams would express depressed maternal care and exhibit similar (same networks), yet different specific changes in RSFC (different individual nuclei) than reported when they were adult females. We have developed an ethologically relevant transgenerational model of the role of chronic social stress (CSS) in the etiology of postpartum depression and anxiety. Initial fMRI investigation of the CSS model indicates that early life exposure to CSS (ECSS) induces long term changes in functional connectivity in adult nulliparous female F1 offspring. ECSS in F1 dams resulted in depressed maternal care specifically during early lactation, consistent with previous CSS studies, and induced changes in functional connectivity in regions associated with sensory processing, maternal and emotional responsiveness, memory, and the reward pathway, with robust changes in anterior cingulate circuits. The sample sizes for the fMRI groups were low, limiting statistical power. This behavioral and functional neuroanatomical foundation can now be used to enhance our understanding of the neural etiology of early life stress associated disorders and test preventative measures and treatments for stress related disorders. Copyright © 2018 Elsevier B.V. All rights reserved.

Effects of Cytochrome P450 (CYP) 2C19 Genotypes on Steady-State Plasma Concentrations of Escitalopram and its Desmethyl Metabolite in Japanese Patients With Depression.

PubMed

Tsuchimine, Shoko; Ochi, Shinichiro; Tajiri, Misuzu; Suzuki, Yutaro; Sugawara, Norio; Inoue, Yoshimasa; Yasui-Furukori, Norio

2018-06-01

Plasma concentrations of the S-enantiomer of citalopram were different between extensive and poor CYP2C19 metabolizers in healthy subjects and depressed patients. However, most studies applied dose-corrected concentrations. Thus, we studied the effects of polymorphisms of the CYP2C19 gene on raw plasma drug concentrations in Japanese patients with depression. Subjects in this study consisted of 412 depressed patients receiving 5, 10, 15, or 20 mg of escitalopram once a day. Plasma concentrations of escitalopram and desmethylescitalopram were quantified using HPLC. CYP2C19 genotypes were identified using polymerase chain reaction methods. There were no differences in the steady-state plasma concentrations of escitalopram or desmethylescitalopram in each dose group (5, 10, 15, or 20 mg of escitalopram) among CYP2C19 genotype groups. However, 1-way analysis of variance showed significant effects of CYP2C19 genotypes on the dose-adjusted plasma concentration of escitalopram but not in the dose-adjusted plasma concentration of desmethylescitalopram. Analysis of covariance including age, sex, and body weight showed significant effects of CYP2C19 genotypes on the dose-adjusted plasma concentration of escitalopram and the ratio of desmethylescitalopram to escitalopram. These findings suggest that the CYP2C19 variants are associated with steady-state plasma concentrations of escitalopram to some extent but are not associated with desmethylescitalopram.

New Insights into the Regulation of Cell-Surface Signaling Activity Acquired from a Mutagenesis Screen of the Pseudomonas putida IutY Sigma/Anti-Sigma Factor

PubMed Central

Bastiaansen, Karlijn C.; Civantos, Cristina; Bitter, Wilbert; Llamas, María A.

2017-01-01

Cell-surface signaling (CSS) is a signal transfer system that allows Gram-negative bacteria to detect environmental signals and generate a cytosolic response. These systems are composed of an outer membrane receptor that senses the inducing signal, an extracytoplasmic function sigma factor (σECF) that targets the cytosolic response by modifying gene expression and a cytoplasmic membrane anti-sigma factor that keeps the σECF in an inactive state in the absence of the signal and transduces its presence from the outer membrane to the cytosol. Although CSS systems regulate bacterial processes as crucial as stress response, iron scavenging and virulence, the exact mechanisms that drive CSS are still not completely understood. Binding of the signal to the CSS receptor is known to trigger a signaling cascade that results in the regulated proteolysis of the anti-sigma factor and the activation of the σECF in the cytosol. This study was carried out to generate new insights in the proteolytic activation of CSS σECF. We performed a random mutagenesis screen of the unique IutY protein of Pseudomonas putida, a protein that combines a cytosolic σECF domain and a periplasmic anti-sigma factor domain in a single polypeptide. In response to the presence of an iron carrier, the siderophore aerobactin, in the extracellular medium, IutY is processed by two different proteases, Prc and RseP, which results in the release and activation of the σIutY domain. Our experiments show that all IutY mutant proteins that contain periplasmic residues depend on RseP for activation. In contrast, Prc is only required for mutant variants with a periplasmic domain longer than 50 amino acids, which indicates that the periplasmic region of IutY is trimmed down to ~50 amino acids creating the RseP substrate. Moreover, we have identified several conserved residues in the CSS anti-sigma factor family of which mutation leads to constitutive activation of their cognate σECF. These findings advance our knowledge on how CSS activity is regulated by the consecutive action of two proteases. Elucidation of the exact mechanism behind CSS activation will enable the development of strategies to block CSS in pathogenic bacteria. PMID:28512454

Isotopic composition of transpiration and rates of change in leaf water isotopologue storage in response to environmental variables.

PubMed

Simonin, Kevin A; Roddy, Adam B; Link, Percy; Apodaca, Randy; Tu, Kevin P; Hu, Jia; Dawson, Todd E; Barbour, Margaret M

2013-12-01

During daylight hours, the isotope composition of leaf water generally approximates steady-state leaf water isotope enrichment model predictions. However, until very recently there was little direct confirmation that isotopic steady-state (ISS) transpiration in fact exists. Using isotope ratio infrared spectroscopy (IRIS) and leaf gas exchange systems we evaluated the isotope composition of transpiration and the rate of change in leaf water isotopologue storage (isostorage) when leaves were exposed to variable environments. In doing so, we developed a method for controlling the absolute humidity entering the gas exchange cuvette for a wide range of concentrations without changing the isotope composition of water vapour. The measurement system allowed estimation of (18)O enrichment both at the evaporation site and for bulk leaf water, in the steady state and the non-steady state. We show that non-steady-state effects dominate the transpiration isoflux even when leaves are at physiological steady state. Our results suggest that a variable environment likely prevents ISS transpiration from being achieved and that this effect may be exacerbated by lengthy leaf water turnover times due to high leaf water contents. © 2013 John Wiley & Sons Ltd.

An analytical model for contaminant transport in landfill composite liners considering coupled effect of consolidation, diffusion, and degradation.

PubMed

Xie, Haijian; Yan, Huaxiang; Feng, Shijin; Wang, Qiao; Chen, Peixiong

2016-10-01

One-dimensional mathematical model is developed to investigate the behavior of contaminant transport in landfill composite liner system considering coupled effect of consolidation, diffusion, and degradation. The first- and second-type bottom boundary conditions are used to derive the steady-state and quasi-steady-state analytical solutions. The concentration profiles obtained by the proposed analytical solution are in good agreement with those obtained by the laboratory tests. The bottom concentration and flux of the soil liners can be greatly reduced when the degradation effect and porosity changing are considered. For the case under steady-state, the bottom flux and concentration for the case with t 1/2 =10 years can be 2.8 and 5.5 times lower than those of the case with t 1/2 =100 years, respectively. The bottom concentration and flux of the soil liners can be greatly reduced when the coefficient of volume compressibility decreases. For quasi-steady-state and with t 1/2 = 10 years, the bottom flux and concentration for the case with m v  = 0.02/MPa can be 17.4 and 21 times lower than the case with m v  = 0.5/MPa. This may be due to the fact that the true fluid velocity induced by consolidation is greater for the case with high coefficient of volume compressibility. The bottom flux for the case with single compacted clay liner (CCL) can be 1.5 times larger than that for the case with GMB/CCL considering diffusion and consolidation for DCM. The proposed analytical model can be used for verification of more complicated numerical models and assessment of the coupled effect of diffusion, consolidation, and degradation on contaminant transport in landfill liner systems.

Steady-state solidification of aqueous ammonium chloride

NASA Astrophysics Data System (ADS)

Peppin, S. S. L.; Huppert, Herbert E.; Worster, M. Grae

We report on a series of experiments in which a Hele-Shaw cell containing aqueous solutions of NH4Cl was translated at prescribed rates through a steady temperature gradient. The salt formed the primary solid phase of a mushy layer as the solution solidified, with the salt-depleted residual fluid driving buoyancy-driven convection and the development of chimneys in the mushy layer. Depending on the operating conditions, several morphological transitions occurred. A regime diagram is presented quantifying these transitions as a function of freezing rate and the initial concentration of the solution. In general, for a given concentration, increasing the freezing rate caused the steady-state system to change from a convecting mushy layer with chimneys to a non-convecting mushy layer below a relatively quiescent liquid, and then to a much thinner mushy layer separated from the liquid by a region of active secondary nucleation. At higher initial concentrations the second of these states did not occur. At lower concentrations, but still above the eutectic, the mushy layer disappeared. A simple mathematical model of the system is developed which compares well with the experimental measurements of the intermediate, non-convecting state and serves as a benchmark against which to understand some of the effects of convection. Movies are available with the online version of the paper.

Simultaneous measurement of glucose transport and utilization in the human brain.

PubMed

Shestov, Alexander A; Emir, Uzay E; Kumar, Anjali; Henry, Pierre-Gilles; Seaquist, Elizabeth R; Öz, Gülin

2011-11-01

Glucose is the primary fuel for brain function, and determining the kinetics of cerebral glucose transport and utilization is critical for quantifying cerebral energy metabolism. The kinetic parameters of cerebral glucose transport, K(M)(t) and V(max)(t), in humans have so far been obtained by measuring steady-state brain glucose levels by proton ((1)H) NMR as a function of plasma glucose levels and fitting steady-state models to these data. Extraction of the kinetic parameters for cerebral glucose transport necessitated assuming a constant cerebral metabolic rate of glucose (CMR(glc)) obtained from other tracer studies, such as (13)C NMR. Here we present new methodology to simultaneously obtain kinetic parameters for glucose transport and utilization in the human brain by fitting both dynamic and steady-state (1)H NMR data with a reversible, non-steady-state Michaelis-Menten model. Dynamic data were obtained by measuring brain and plasma glucose time courses during glucose infusions to raise and maintain plasma concentration at ∼17 mmol/l for ∼2 h in five healthy volunteers. Steady-state brain vs. plasma glucose concentrations were taken from literature and the steady-state portions of data from the five volunteers. In addition to providing simultaneous measurements of glucose transport and utilization and obviating assumptions for constant CMR(glc), this methodology does not necessitate infusions of expensive or radioactive tracers. Using this new methodology, we found that the maximum transport capacity for glucose through the blood-brain barrier was nearly twofold higher than maximum cerebral glucose utilization. The glucose transport and utilization parameters were consistent with previously published values for human brain.

Plasma concentrations of midazolam during continuous subcutaneous administration in palliative care.

PubMed

Bleasel, M D; Peterson, G M; Dunne, P F

1994-01-01

We have investigated the steady-state plasma concentrations of midazolam during continuous subcutaneous administration in palliative care. Using a sensitive gas chromatography with electron capture detector assay, plasma concentrations of midazolam were measured in 11 patients (median age 68 years; range 47-82 years; six females) receiving the drug by continuous subcutaneous infusion (median rate 20 mg/day; range 10-60 mg/day). While not significant, the infusion rate tended to decrease with increasing age of the patient (Spearman's p = -0.51; p = 0.11). The steady-state plasma concentration range was 10-147 ng/ml, with a median of 30 ng/ml. Infusion rates and plasma concentrations of midazolam were correlated (Spearman's p = 0.71; p < 0.05). No other significant relationships were found between plasma concentrations and the variables of age, sex and liver function.

Steady-state studies of the reactions of H2O-CO and CO2-H2 mixtures with liquid iron

NASA Astrophysics Data System (ADS)

Sasaki, Y.; Belton, G. R.

1998-08-01

Studies have been made of the steady-stata composition of liquid iron exposed to high flow rates of H2O-CO mixtures at 1550 °C to 1700 °C and CO2-H2 mixtures at 1600 °C. Values of the steady-state activity of oxygen have been established by measurement of either the carbon concentration or the silicon concentration when the iron was held in a silica crucible. Additions of sulfur or selenium to the iron have been found to result in steady-state oxygen activities, which differ significantly from those expected from water-gas equilibrium. The results are interpreted to show that the ratio of the apparent first-order rate constants for the reactions of H2O and CO2 with liquid iron is about 3 at 1600 °C. It is shown that the dependencies of the rate constants on the activities of sulfur, oxygen, and selenium must, even if complex, be similar for the H2O and CO2 reactions with liquid iron, to a good approximation.

Brachytherapy Is Associated With Improved Survival in Inoperable Stage I Endometrial Adenocarcinoma: A Population-Based Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Acharya, Sahaja; Perkins, Stephanie M.; DeWees, Todd

2015-11-01

Purpose: To assess the use of brachytherapy (BT) with or without external beam radiation (EBRT) in inoperable stage I endometrial adenocarcinoma in the United States and to determine the effect of BT on overall survival (OS) and cause-specific survival (CSS). Methods and Materials: Data between 1998 and 2011 from the National Cancer Institute's Surveillance, Epidemiology and End Results database were analyzed. Coarsened exact matching was used to adjust for differences in age and grade between patients who received BT and those who did not. Prognostic factors affecting OS and CSS were evaluated using the Kaplan-Meier product-limit method and a Coxmore » proportional hazards regression model. Results: A total of 460 patients with inoperable stage I endometrial adenocarcinoma treated with radiation therapy were identified. Radiation consisted of either EBRT (n=260) or BT with or without EBRT (n=200). The only factor associated with BT use was younger patient age (median age, 72 vs 76 years, P=.001). Patients who received BT had a higher 3-year OS (60% vs 47%, P<.001) and CSS (82% vs 74%, P=.032) compared with those who did not. On multivariate analysis, BT use was independently associated with an improved OS (hazard ratio [HR] 0.67, 95% confidence interval [CI] 0.52-0.87) and CSS (HR 0.61, 95% CI 0.39-0.93). When patients were matched on age, BT use remained significant on multivariate analysis for OS (HR 0.65, 95% CI 0.48-0.87) and CSS (HR 0.52, 95% CI 0.31-0.84). When matched on age and grade, BT remained independently associated with improved OS and CSS (OS HR 0.62, 95% CI 0.46-0.83; CSS HR 0.57, 95% CI 0.34-0.92). Conclusion: Brachytherapy is independently associated with improved OS and CSS. It should be considered as part of the treatment regimen for stage I inoperable endometrial cancer patients undergoing radiation.« less

Towers of generalized divisible quantum codes

NASA Astrophysics Data System (ADS)

Haah, Jeongwan

2018-04-01

A divisible binary classical code is one in which every code word has weight divisible by a fixed integer. If the divisor is 2ν for a positive integer ν , then one can construct a Calderbank-Shor-Steane (CSS) code, where X -stabilizer space is the divisible classical code, that admits a transversal gate in the ν th level of Clifford hierarchy. We consider a generalization of the divisibility by allowing a coefficient vector of odd integers with which every code word has zero dot product modulo the divisor. In this generalized sense, we construct a CSS code with divisor 2ν +1 and code distance d from any CSS code of code distance d and divisor 2ν where the transversal X is a nontrivial logical operator. The encoding rate of the new code is approximately d times smaller than that of the old code. In particular, for large d and ν ≥2 , our construction yields a CSS code of parameters [[O (dν -1) ,Ω (d ) ,d ] ] admitting a transversal gate at the ν th level of Clifford hierarchy. For our construction we introduce a conversion from magic state distillation protocols based on Clifford measurements to those based on codes with transversal T gates. Our tower contains, as a subclass, generalized triply even CSS codes that have appeared in so-called gauge fixing or code switching methods.

Perfluorooctanoate: Placental and lactational transport pharmacokinetics in rats.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hinderliter, Paul M.; Mylchreest, E.; Gannon, S. A.

This study was conducted to develop a quantitative understanding of the potential for gestational and lactational transfer of perfluorooctanoate (PFOA) in the rat. Time-mated female rats were dosed by oral gavage once daily at concentrations of 3, 10, or 30 mg/kg/day of the ammonium salt of PFOA (APFO) starting on gestation (G) day 4 and continuing until sacrifice. On days 10, 15, and 21G, five rats per dose level were sacrificed and blood samples were collected 2h post-dose. Embryos were collected on day 10G, amniotic fluid, placentas, and embryos/fetuses were collected on days 15 and 21G, and fetal blood samplesmore » were collected on day 21G. Five rats per dose level were allowed to deliver and nurse their litters, and on days 3, 7, 14, and 21 post-partum (PP) milk and blood samples of maternal and pup were collected 2h post-dose. All samples were analyzed by high-performance liquid chromatography-mass spectrometry (HPLC-MS) for PFOA concentration. Concentrations of PFOA in maternal plasma and milk attained steady state during the sampling interval. The steady-state concentrations in maternal plasma were 10-15, 25-30, and 60-75 microg/mL in rats receiving 3, 10, and 30 mg/kg, respectively. Steady-state concentrations in milk were approximately 10 times less than those in maternal plasma. The concentration of PFOA in fetal plasma on day 21G was approximately half the steady-state concentration in maternal plasma. The milk concentrations appeared to be generally comparable to the concentrations in pup plasma. Pup plasma concentrations decreased from day 3PP to day 7PP, and were similar on days 7, 14, and 21PP at all dose levels. PFOA was detected in placenta (days 15 and 21G), amniotic fluid (days 15 and 21G), embryo (days 10 and 15G), and fetus (day 21G). These pharmacokinetics allow estimation of the dose to developing and nursing rat offspring following maternal exposure.« less

Secondary organic aerosol from ozone-initiated reactions with terpene-rich household products

NASA Astrophysics Data System (ADS)

Coleman, Beverly K.; Lunden, Melissa M.; Destaillats, Hugo; Nazaroff, William W.

We analyzed secondary organic aerosol (SOA) data from a series of small-chamber experiments in which terpene-rich vapors from household products were combined with ozone under conditions analogous to product use indoors. Reagents were introduced into a continuously ventilated 198 L chamber at steady rates. Consistently, at the time of ozone introduction, nucleation occurred exhibiting similar behavior to atmospheric events. The initial nucleation burst and growth was followed by a period in which approximately stable particle levels were established, reflecting a balance between new particle formation, condensational growth, and removal by ventilation. Airborne particles were measured with a scanning mobility particle sizer (SMPS, 10-400 nm) in every experiment and with an optical particle counter (OPC, 0.1-2.0 μm) in a subset. Parameters for a three-mode lognormal fit to the size distribution at steady state were determined for each experiment. Increasing the supply ozone level increased the steady-state mass concentration and yield of SOA from each product tested. Decreasing the air-exchange rate increased the yield. The steady-state fine-particle mass concentration (PM 1.1) ranged from 10 to >300 μg m -3 and yields ranged from 5% to 37%. Steady-state nucleation rates and SOA mass formation rates were ˜10 cm -3 s -1 and ˜10 μg m -3 min -1, respectively.

Secondary organic aerosol from ozone-initiated reactions with terpene-rich household products

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coleman, Beverly; Coleman, Beverly K.; Lunden, Melissa M.

2008-01-01

We analyzed secondary organic aerosol (SOA) data from a series of small-chamber experiments in which terpene-rich vapors from household products were combined with ozone under conditions analogous to product use indoors. Reagents were introduced into a continuously ventilated 198 L chamber at steady rates. Consistently, at the time of ozone introduction, nucleation occurred exhibiting behavior similar to atmospheric events. The initial nucleation burst and growth was followed by a period in which approximately stable particle levels were established reflecting a balance between new particle formation, condensational growth, and removal by ventilation. Airborne particles were measured with a scanning mobility particlemore » sizer (SMPS, 10 to 400 nm) in every experiment and with an optical particle counter (OPC, 0.1 to 2.0 ?m) in a subset. Parameters for a three-mode lognormal fit to the size distribution at steady state were determined for each experiment. Increasing the supply ozone level increased the steady-state mass concentration and yield of SOA from each product tested. Decreasing the air-exchange rate increased the yield. The steady-state fine-particle mass concentration (PM1.1) ranged from 10 to> 300 mu g m-3 and yields ranged from 5percent to 37percent. Steady-state nucleation rates and SOA mass formation rates were on the order of 10 cm-3 s-1 and 10 mu g m-3 min-1, respectively.« less

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Effects of gas reservoir configuration and pore radius on shale gas nanoflow: A molecular dynamics study.

PubMed

Tian, Huiquan; Guo, Guang-Jun; Geng, Ming; Zhang, Zhengcai; Zhang, Mingmin; Gao, Kai

2018-05-28

We calculated methane transport through cylindrical graphite nanopores in cyclical steady-state flows using non-equilibrium molecular dynamics simulations. First, two typical gas reservoir configurations were evaluated: open (OS) and closed (CS) systems in which pores connect to the gas reservoir without/with a graphite wall parallel to the gas flow. We found that the OS configuration, which is commonly used to study nanoflows, exhibited obvious size effects. Smaller gas reservoir cross-sectional areas were associated with faster gas flows. Because Knudsen diffusion and slip flow in pores are interrupted in a gas reservoir that does not have walls as constraints, OSs cannot be relied upon in cyclical nanoflow simulations. Although CSs eliminated size effects, they introduced surface roughness effects that stem from the junction surface between the gas reservoir and the pore. To obtain a convergent nanoflow, the length of a side of the gas reservoir cross-section should be at least 2 nm larger than the pore diameter. Second, we obtained methane flux data for various pore radii (0.5-2.5 nm) in CSs and found that they could be described accurately using the Javadpour formula. This is the first direct molecular simulation evidence to validate this formula. Finally, the radial density and flow-velocity distributions of methane in CS pores were analyzed in detail. We tested pores with a radius between 0.5 nm and 2.5 nm and determined that the maximum ratio (∼34%) of slip flow to overall flow occurred in the pore with a radius of 1.25 nm. This study will aid in the design of gas reservoir configurations for nanoflow simulations and is helpful in understanding shale gas nanoflows.

Effects of gas reservoir configuration and pore radius on shale gas nanoflow: A molecular dynamics study

NASA Astrophysics Data System (ADS)

Tian, Huiquan; Guo, Guang-Jun; Geng, Ming; Zhang, Zhengcai; Zhang, Mingmin; Gao, Kai

2018-05-01

We calculated methane transport through cylindrical graphite nanopores in cyclical steady-state flows using non-equilibrium molecular dynamics simulations. First, two typical gas reservoir configurations were evaluated: open (OS) and closed (CS) systems in which pores connect to the gas reservoir without/with a graphite wall parallel to the gas flow. We found that the OS configuration, which is commonly used to study nanoflows, exhibited obvious size effects. Smaller gas reservoir cross-sectional areas were associated with faster gas flows. Because Knudsen diffusion and slip flow in pores are interrupted in a gas reservoir that does not have walls as constraints, OSs cannot be relied upon in cyclical nanoflow simulations. Although CSs eliminated size effects, they introduced surface roughness effects that stem from the junction surface between the gas reservoir and the pore. To obtain a convergent nanoflow, the length of a side of the gas reservoir cross-section should be at least 2 nm larger than the pore diameter. Second, we obtained methane flux data for various pore radii (0.5-2.5 nm) in CSs and found that they could be described accurately using the Javadpour formula. This is the first direct molecular simulation evidence to validate this formula. Finally, the radial density and flow-velocity distributions of methane in CS pores were analyzed in detail. We tested pores with a radius between 0.5 nm and 2.5 nm and determined that the maximum ratio (˜34%) of slip flow to overall flow occurred in the pore with a radius of 1.25 nm. This study will aid in the design of gas reservoir configurations for nanoflow simulations and is helpful in understanding shale gas nanoflows.

The effect of dissolve gas concentration in the initial growth stage of multi cavitation bubbles. Differences between vacuum degassing and ultrasound degassing.

PubMed

Yanagida, Hirotaka

2008-04-01

The sonochemical luminescence intensity from luminol was measured at a sampling rate of several kilohertz. This was noted at three different periods: first, the latent period in which no light emission occurs at all; second, the increased emission period from the start of light emission to the time when a steady state is reached; and third, the steady state period in which light emission occurs at the steady state value. When irradiated with ultrasound of different intensities, the times of the latent period and increased emission period are shorter for higher ultrasound intensities. To know how the dissolved oxygen content is involved in early-stage cavitation growth, an experiment was conducted using solutions with varying dissolved oxygen contents from 100% to 37%. For dissolved air content of 50% or less, it was found that the latent period was 30 times longer in a saturated condition. It was also found that the increased emission period was 10 times longer. However, the emission intensity in the steady state did not change at all even when the initial dissolved gas concentration of the sample was changed. From this, it was found that the reuse of collapsed bubbles takes place efficiently in the steady state. Dissolved oxygen was reduced by the use of a vacuum pump and by the degassing action of ultrasound, and it was discovered that the behavior of transient emission differed for the two ways of degassing.

Analgesic plasma concentrations of morphine in children with terminal malignancy receiving a continuous subcutaneous infusion of morphine sulfate to control severe pain.

PubMed

Nahata, M C; Miser, A W; Miser, J S; Reuning, R H

1984-02-01

Three children with terminal malignancy received a continuous subcutaneous infusion of morphine sulfate for the control of severe pain, the morphine dose being adjusted until the patient and/or parent reported complete freedom from pain. Analgesic plasma morphine concentrations at the steady state in these patients ranged from 12.9 to 57 ng/ml (median 19.6 ng/ml) while receiving morphine doses of 0.45-2.0 mg/h (0.034-0.06 mg/kg/h). One patient, who received 2 mg morphine per hour for 12 days demonstrated a 2-fold variation in steady-state plasma concentration during this period.

Absolute cross sections for electronic excitation of condensed tetrahydrofuran (THF) by 11-16 eV electrons.

PubMed

Lemelin, V; Bass, A D; Cloutier, P; Sanche, L

2016-11-07

Absolute cross section (CS) data on the interaction of low energy electrons with DNA and its molecular constituents are required as input parameters in Monte-Carlo type simulations, for several radiobiological applications. Previously [V. Lemelin et al., J. Chem. Phys. 144, 074701 (2016)], we measured absolute vibrational CSs for low-energy electron scattering from condensed tetrahydrofuran, a convenient surrogate for the deoxyribose. Here we report absolute electronic CSs for energy losses of between 6 and 11.5 eV, by electrons with energies between 11 and 16 eV. The variation of these CSs with incident electron energy shows no evidence of transient anion states, consistent with theoretical and other experimental results, indicating that initial electron capture leading to DNA strand breaks occurs primarily on DNA bases or the phosphate group.

Metronidazole and Hydroxymetronidazole Central Nervous System Distribution: 1. Microdialysis Assessment of Brain Extracellular Fluid Concentrations in Patients with Acute Brain Injury

PubMed Central

Frasca, Denis; Dahyot-Fizelier, Claire; Adier, Christophe; Mimoz, Olivier; Debaene, Bertrand; Couet, William

2014-01-01

The distribution of metronidazole in the central nervous system has only been described based on cerebrospinal fluid data. However, extracellular fluid (ECF) concentrations may better predict its antimicrobial effect and/or side effects. We sought to explore by microdialysis brain ECF metronidazole distribution in patients with acute brain injury. Four brain-injured patients monitored by cerebral microdialysis received 500 mg of metronidazole over 0.5 h every 8 h. Brain dialysates and blood samples were collected at steady state over 8 h. Probe recoveries were evaluated by in vivo retrodialysis in each patient for metronidazole. Metronidazole and OH-metronidazole were assayed by high-pressure liquid chromatography, and a noncompartmental pharmacokinetic analysis was performed. Probe recovery was equal to 78.8% ± 1.3% for metronidazole in patients. Unbound brain metronidazole concentration-time curves were delayed compared to unbound plasma concentration-time curves but with a mean metronidazole unbound brain/plasma AUC0–τ ratio equal to 102% ± 19% (ranging from 87 to 124%). The unbound plasma concentration-time profiles for OH-metronidazole were flat, with mean average steady-state concentrations equal to 4.0 ± 0.7 μg ml−1. This microdialysis study describes the steady-state brain distribution of metronidazole in patients and confirms its extensive distribution. PMID:24277041

Estimation of aquifer radionuclide concentrations by postprocessing of conservative tracer model results

NASA Astrophysics Data System (ADS)

Gedeon, M.; Vandersteen, K.; Rogiers, B.

2012-04-01

Radionuclide concentrations in aquifers represent an important indicator in estimating the impact of a planned surface disposal for low and medium level short-lived radioactive waste in Belgium, developed by the Belgian Agency for Radioactive Waste and Enriched Fissile Materials (ONDRAF/NIRAS), who also coordinates and leads the corresponding research. Estimating aquifer concentrations for individual radionuclides represents a computational challenge because (a) different retardation values are applied to different hydrogeologic units and (b) sequential decay reactions with radionuclides of various sorption characteristics cause long computational times until a steady-state is reached. The presented work proposes a methodology reducing substantially the computational effort by postprocessing the results of a prior non-reactive tracer simulation. These advective transport results represent the steady-state concentration - source flux ratio and the break-through time at each modelling cell. These two variables are further used to estimate the individual radionuclide concentrations by (a) scaling the steady-state concentrations to the source fluxes of individual radionuclides; (b) applying the radioactive decay and ingrowth in a decay chain; (c) scaling the travel time by the retardation factor and (d) applying linear sorption. While all steps except (b) require solving simple linear equations, applying ingrowth of individual radionuclides in decay chains requires solving the differential Bateman equation. This equation needs to be solved once for a unit radionuclide activity at all arrival times found in the numerical grid. The ratios between the parent nuclide activity and the progeny activities are then used in the postprocessing. Results are presented for discrete points and examples of radioactive plume maps are given. These results compare well to the results achieved using a full numerical simulation including the respective chemical reaction processes. Although the proposed method represents a fast way to estimate the radionuclide concentrations without performing timely challenging simulations, its applicability has some limits. The radionuclide source needs to be assumed constant during the period of achieving a steady-state in the model. Otherwise, the source variability of individual radionuclides needs to be modelled using a numerical simulation. However, such a situation only occurs in cases of source variability in a period until steady-state is reached and such a simulation takes a relatively short time. The proposed method enables an effective estimation of individual radionuclide concentrations in the frame of performance assessment of a radioactive waste disposal. Reducing the calculation time to a minimum enables performing sensitivity and uncertainty analyses, testing alternative models, etc. thus enhancing the overall quality of the modelling analysis.

Performance Evaluation of Child Safety Seats in Far-Side Lateral Sled Tests at Varying Speeds

PubMed Central

Ghati, Yoganand; Menon, Rajiv A.; Milone, Mary; Lankarani, Hamid; Oliveres, Gerardo

2009-01-01

Protection of children in Child Safety Seats (CSS) in side impact crashes has been a topic of recent studies. The objective of this study was to evaluate the performance of CSS in far-side impacts through a series of sled tests conducted at varying test speeds. Forty eight sled tests were conducted at three speeds (24 km/h, 29 km/h and 36 km/h), under two different CSS attachment conditions (LATCH and seat belt attached), using rear facing and forward facing CSS from four different manufacturers. Analyses were conducted to examine head retention within the CSS, velocity of the head as it passes an imaginary plane (cross over into other occupant space or door), lateral trajectory of the head and knee; head, chest and pelvis accelerations; neck and lumbar loads and moments. In addition to these parameters, the CSS were visually inspected for structural integrity after each test. Results from these sled tests highlighted the differential performance of CSS in far-side impacts. During the tests, all CSS experienced significant lateral movement irrespective of attachment type. In rear facing CSS tests, one of the designs failed as the seat disengaged from its base. In forward facing CSS tests, it was observed that the seat belt attached CSS experienced less rotational motion than the LATCH attached CSS. ATD head retention within the seat was not achieved with either CSS attachments at any speed. The findings from this study augment the current efforts to define regulatory sled setup procedure for far-side impact crashes involving children in CSS, which currently does not exist and will eventually further the protection of children in automobiles. PMID:20184846

The Steady-State Transport of Oxygen through Hemoglobin Solutions

PubMed Central

Keller, K. H.; Friedlander, S. K.

1966-01-01

The steady-state transport of oxygen through hemoglobin solutions was studied to identify the mechanism of the diffusion augmentation observed at low oxygen tensions. A novel technique employing a platinum-silver oxygen electrode was developed to measure the effective diffusion coefficient of oxygen in steady-state transport. The measurements were made over a wider range of hemoglobin and oxygen concentrations than previously reported. Values of the Brownian motion diffusion coefficient of oxygen in hemoglobin solution were obtained as well as measurements of facilitated transport at low oxygen tensions. Transport rates up to ten times greater than ordinary diffusion rates were found. Predictions of oxygen flux were made assuming that the oxyhemoglobin transport coefficient was equal to the Brownian motion diffusivity which was measured in a separate set of experiments. The close correlation between prediction and experiment indicates that the diffusion of oxyhemoglobin is the mechanism by which steady-state oxygen transport is facilitated. PMID:5943608

Patterns of primary productivity and biomass in a coastal upwelling region

NASA Astrophysics Data System (ADS)

Small, Lawrence F.; Menzies, David W.

1981-02-01

Average distributions of chlorophyll α during upwelling in areas of smooth bathymetry off Oregon have been computed from historical data. Chlorophyll concentrations in cross-shelf sections over the Oregon continental shelf (44°40'N) were similar to those in cross-shelf sections off northwest Africa during JOINT-1 studies but differed from those in similar sections over an adjacent narrow region of the Oregon shelf (44°55'N to 45°12'N). The fact that larger concentration differences can occur along short sections of one coastline than between upwelling regions half a world apart bears on the time and space scales of sampling and might have bearing on the support and distributions of other trophic levels. Relationships between the local winds and the broader-scale BAKUN (1975) upwelling indices were used to classify various phytoplankton biomass and primary productivity distributions according to whether they were in strong upwelling steady state, weak upwelling steady state, or one of two transition states. The upwelling steady state conforms to the 'upwelling event' scale (about 3 to 10 days) of WALSH, WHITLEDGE, KELLEY, HUNTSMAN and PILLSBURY (1977) and the transition state of approximately one-day duration might specify the critical scale for driving the upwelling off Oregon. Under strong steady-state upwelling in early summer a single band of high primary productivity and biomass develops in the surface layer parallel to the bottom contours, but under similar upwelling conditions in later summer a two-celled zonal circulation occurs and two parallel bands develop. Our strong upwelling distributions are discussed in light of current models of the Oregon upwelling system. Maintenance of biological properties through time in the upwelling bands is also discussed. Under weak steady-state upwelling the primary productivity and biomass bands are farther inshore or immediately against the coast. Productivity in the weak upwelling bands can be twice that of the strong upwelling bands and often 20 times that in surrounding water. Under transient conditions in which the local winds are favorable for strong upwelling but the slower-responding Bakun index indicates weak upwelling, chlorophyll distributions change within a day to resemble distributions during strong steady-state upwelling. Under transient conditions in which the local winds weaken dramatically but the Bakun index still indicates strong upwelling, chlorophyll concentrations are high and widely distributed throughout the upwelling region.

Prognostic and diagnostic impact of fibrinogen, neutrophil-to-lymphocyte ratio, and platelet-to-lymphocyte ratio on thymic epithelial tumors outcome

PubMed Central

Janik, Stefan; Raunegger, Thomas; Hacker, Philipp; Ghanim, Bahil; Einwallner, Elisa; Müllauer, Leonhard; Schiefer, Ana-Iris; Moser, Julia; Klepetko, Walter; Ankersmit, Hendrik Jan; Moser, Bernhard

2018-01-01

Background Peripheral blood-derived inflammation-based markers, such as Neutrophil-to-Lymphocyte Ratio (NLR), Platelet-to-Lymphocyte Ratio (PLR), and Fibrinogen have been identified as prognostic markers in various solid malignancies. Here we aimed to investigate the prognostic and diagnostic impact of NLR, PLR, and Fibrinogen in patients with thymic epithelial tumors (TETs). Results Pretreatment Fibrinogen serum concentrations, NLRs and PLRs were highest in patients with TCs and advanced tumor stages. High pretreatment Fibrinogen serum concentration (≥452.5 mg/dL) was significantly associated with worse cause specific survival (CSS; p = 0.001) and freedom from recurrence (FFR; p = 0.043), high NLR (≥4.0) with worse FFR (p = 0.008), and high PLR (≥136.5) with worse CSS (p = 0.032). Longitudinal analysis revealed that compared to patients without tumor recurrence, patients with tumor recurrence had significantly higher NLR (11.8 ± 4.0 vs. 4.70 ± 0.5; p = 0.001) and PLR (410.8 ± 149.1 vs. 228.3 ± 23.7; p = 0.031). Conclusion Overall, Fibrinogen serum concentrations, NLRs, and PLRs were associated with higher tumor stage, more aggressive tumor behavior, recurrence, and worse outcome. Prospective multicenter studies of the diagnostic and prognostic potential of Fibrinogen, NLR, and PLR are warranted. Methods This retrospective analysis included 122 patients with TETs who underwent surgical resection between 1999-2015. Fibrinogen serum concentrations, NLRs, and PLRs were measured in patients preoperatively, postoperatively, and later during follow-up. These markers were analyzed for association with several clinical variables, including tumor stage, tumor subtype, FFR, and CSS and to evaluate their prognostic and diagnostic impact for detecting tumor recurrence. PMID:29774108

Car child safety seats use among Iranian children in Mashad.

PubMed

Karbakhsh, Mojgan; Jarahi, Lida

2016-01-01

Despite the strong evidence of child safety seats (CSSs) effectiveness in reducing injuries, it is still rarely used in some societies. The purpose of this study was to determine prevalence and predictors of CSS use in Mashad, Iran. Five hundred ninety kindergarten children whose parents owned a car were enrolled in the study. Parents were asked about using CSS for their children, reasons for CSS use/non-use, demographics, history of road traffic injuries and receiving any advice on CSS. Of families, 25.5% expressed that they used CSS for their child at present or any time in the past, but only 6.3% of children travelled restrained in CSS at the time of study. Age-appropriate CSS use was reported in 14.5% of infants and 2.3% of 1-5-year-old children. A significant relationship was observed between lower child age, higher maternal education and high family income with CSS use. The main reasons for CSS none-use were reported as not feeling the need (42%), followed by its high price (22%). Use of CSS was uncommon. The financial concerns and information gap about the essential need for CSS should be considered as priorities for action especially among lower socio-economic groups of society.

Concentration dependency in nicotine skin penetration flux from aqueous solutions reflects vehicle induced changes in nicotine stratum corneum retention.

PubMed

Kuswahyuning, Rina; Roberts, Michael S

2014-06-01

This study sought to understand the mechanism by which the steady state flux of nicotine across the human skin from aqueous solutions is markedly decreased at higher nicotine concentrations. Nicotine's steady state flux through human epidermis and its amount in the stratum corneum for a range of aqueous nicotine solutions was determined using Franz diffusion cells, with the nicotine analysed by high performance liquid chromatography (HPLC). Nicotine's thermodynamic activity in the various solutions was estimated from its partial vapour pressure and stratum corneum hydration was determined using a corneometer. The amount of nicotine retained in the stratum corneum was estimated from the nicotine amount found in individual stratum corneum tape strips and a D-Squame determined weight for each strip. The observed steady state flux of nicotine across human epidermis was found to show a parabolic dependence on nicotine concentration, with the flux proportional to its thermodynamic activity up to a concentration of 48% w/w. The nicotine retention in the stratum corneum showed a similar dependency on concentration whereas the diffusivity of nicotine in the stratum corneum appeared to be concentration independent. This retention, in turn, could be estimated from the extent of stratum corneum hydration and the nicotine concentration in the applied solution and volume of water in the skin. Nonlinear dependency of nicotine skin flux on its concentration results from a dehydration induced decrease in its stratum corneum retention at higher concentration and not dehydration induced changes nicotine diffusivity in the stratum corneum.

Control of Growth Rate by Initial Substrate Concentration at Values Below Maximum Rate

PubMed Central

Gaudy, Anthony F.; Obayashi, Alan; Gaudy, Elizabeth T.

1971-01-01

The hyperbolic relationship between specific growth rate, μ, and substrate concentration, proposed by Monod and used since as the basis for the theory of steady-state growth in continuous-flow systems, was tested experimentally in batch cultures. Use of a Flavobacterium sp. exhibiting a high saturation constant for growth in glucose minimal medium allowed direct measurement of growth rate and substrate concentration throughout the growth cycle in medium containing a rate-limiting initial concentration of glucose. Specific growth rates were also measured for a wide range of initial glucose concentrations. A plot of specific growth rate versus initial substrate concentration was found to fit the hyperbolic equation. However, the instantaneous relationship between specific growth rate and substrate concentration during growth, which is stated by the equation, was not observed. Well defined exponential growth phases were developed at initial substrate concentrations below that required for support of the maximum exponential growth rate and a constant doubling time was maintained until 50% of the substrate had been used. It is suggested that the external substrate concentration initially present “sets” the specific growth rate by establishing a steady-state internal concentration of substrate, possibly through control of the number of permeation sites. PMID:5137579

Steady-state pharmacokinetics of (R)- and (S)-methadone in methadone maintenance patients

PubMed Central

Foster, David J R; Somogyi, Andrew A; Dyer, Kyle R; White, Jason M; Bochner, Felix

2000-01-01

Aims To investigate the steady-state pharmacokinetics of (R)- and (S)-methadone in a methadone maintenance population. Methods Eighteen patients recruited from a public methadone maintenance program underwent an interdosing interval pharmacokinetic study. Plasma and urine samples were collected and analysed for methadone and its major metabolite (EDDP) using stereoselective h.p.l.c. Methadone plasma protein binding was examined using ultrafiltration, and plasma α1-acid glycoprotein concentrations were quantified by radial immunoassay. Results (R)-methadone had a significantly (P < 0.05) greater unbound fraction (mean 173%) and total renal clearance (182%) compared with (S)-methadone, while maximum measured plasma concentrations (83%) and apparent partial clearance of methadone to EDDP (76%) were significantly (P < 0.001) lower. When protein binding was considered (R)-methadone plasma clearance of the unbound fraction (59%) and apparent partial intrinsic clearance to EDDP (44%) were significantly (P < 0.01) lower than for (S)-methadone, while AUCτSS, (167%) was significantly (P < 0.001) greater. There were no significant (P > 0.2) differences between the methadone enantiomers for AUCτSS, steady-state plasma clearance, trough plasma concentrations and unbound renal clearance. Patients excreted significantly (P < 0.0001) more (R)-methadone and (S)-EDDP than the corresponding enantiomers. Considerable interindividual variability was observed for the pharmacokinetic parameters, with coefficients of variation of up to 70%. Conclusions Steady-state pharmacokinetics of unbound methadone are stereoselective, and there is large interindividual variability consistent with CYP3A4 mediated metabolism to the major metabolite EDDP; the variability did not obscure a significant dose-plasma concentration relationship. Stereoselective differences in the pharmacokinetics of methadone may have important implications for pharmacokinetic-pharmacodynamic modelling but is unlikely to be important for therapeutic drug monitoring of methadone, in the setting of opioid dependence. PMID:11069437

Circulating DNA: a potential marker of sickle cell crisis.

PubMed

Vasavda, Nisha; Ulug, Pinar; Kondaveeti, Sheila; Ramasamy, Karthik; Sugai, Taku; Cheung, Gordon; Rees, David C; Awogbade, Moji; Bannister, Sybil; Cunningham, Juliette; Menzel, Stephan; Thein, Swee Lay

2007-10-01

Free circulating DNA is present in the plasma of healthy subjects, and is elevated in conditions characterized by increased cell death, such as cancer and physical trauma. Analysis of circulating DNA in plasma could provide a useful biomarker in sickle cell disease (SCD) in view of the increased cell turnover through chronic ongoing haemolysis, recurrent vaso-occlusion and inflammation. Plasma DNA was determined by real-time quantitative polymerase chain reaction (PCR) amplification of the beta-globin gene (HBB) in 154 patients with SCD [105 haemoglobin (Hb)SS, 46 HbSC and three HbS/beta(0) thalassaemia] and 53 ethnically matched controls. Blood samples were obtained from all patients in steady state; 21 of the 154 patients were also sampled during admission to hospital for acute pain. Median concentration of circulating plasma DNA in acute pain was more than 10-fold that in steady state and in controls - 10070 vs. 841 and 10070 vs. 933 genome equivalents/ml respectively (P < 0.0001, in both cases). During steady state, patients had plasma DNA levels similar to controls. Plasma DNA levels in SCD correlated with C-reactive protein levels (P < 0.005) and total white cell counts (P < 0.05) in steady state. The study shows that plasma DNA concentration may have potential as a biomarker in sickle cell patients.

Dynamic thermal analysis of a concentrated photovoltaic system

NASA Astrophysics Data System (ADS)

Avrett, John T., II; Cain, Stephen C.; Pochet, Michael

2012-02-01

Concentrated photovoltaic (PV) technology represents a growing market in the field of terrestrial solar energy production. As the demand for renewable energy technologies increases, further importance is placed upon the modeling, design, and simulation of these systems. Given the U.S. Air Force cultural shift towards energy awareness and conservation, several concentrated PV systems have been installed on Air Force installations across the country. However, there has been a dearth of research within the Air Force devoted to understanding these systems in order to possibly improve the existing technologies. This research presents a new model for a simple concentrated PV system. This model accurately determines the steady state operating temperature as a function of the concentration factor for the optical part of the concentrated PV system, in order to calculate the optimum concentration that maximizes power output and efficiency. The dynamic thermal model derived is validated experimentally using a commercial polysilicon solar cell, and is shown to accurately predict the steady state temperature and ideal concentration factor.

Transport of a decay chain in homogenous porous media: analytical solutions.

PubMed

Bauer, P; Attinger, S; Kinzelbach, W

2001-06-01

With the aid of integral transforms, analytical solutions for the transport of a decay chain in homogenous porous media are derived. Unidirectional steady-state flow and radial steady-state flow in single and multiple porosity media are considered. At least in Laplace domain, all solutions can be written in closed analytical formulae. Partly, the solutions can also be inverted analytically. If not, analytical calculation of the steady-state concentration distributions, evaluation of temporal moments and numerical inversion are still possible. Formulae for several simple boundary conditions are given and visualized in this paper. The derived novel solutions are widely applicable and are very useful for the validation of numerical transport codes.

Study of dynamics of glucose-glucose oxidase-ferricyanide reaction

NASA Astrophysics Data System (ADS)

Nováková, A.; Schreiberová, L.; Schreiber, I.

2011-12-01

This work is focused on dynamics of the glucose-glucose oxidase-ferricyanide enzymatic reaction with or without sodium hydroxide in a continuous-flow stirred tank reactor (CSTR) and in a batch reactor. This reaction exhibits pH-variations having autocatalytic character and is reported to provide nonlinear dynamic behavior (bistability, excitability). The dynamical behavior of the reaction was examined within a wide range of inlet parameters. The main inlet parameters were the ratio of concentrations of sodium hydroxide and ferricyanide and the flow rate. In a batch reactor we observed an autocatalytic drop of pH from slightly basic to medium acidic values. In a CSTR our aim was to find bistability in the presence of sodium hydroxide. However, only a basic steady state was found. In order to reach an acidic steady state, we investigated the system in the absence of sodium hydroxide. Under these conditions the transition from the basic to the acidic steady state was observed when inlet glucose concentration was increased.

Analytical solutions of one-dimensional multispecies reactive transport in a permeable reactive barrier-aquifer system

NASA Astrophysics Data System (ADS)

Mieles, John; Zhan, Hongbin

2012-06-01

The permeable reactive barrier (PRB) remediation technology has proven to be more cost-effective than conventional pump-and-treat systems, and has demonstrated the ability to rapidly reduce the concentrations of specific chemicals of concern (COCs) by up to several orders of magnitude in some scenarios. This study derives new steady-state analytical solutions to multispecies reactive transport in a PRB-aquifer (dual domain) system. The advantage of the dual domain model is that it can account for the potential existence of natural degradation in the aquifer, when designing the required PRB thickness. The study focuses primarily on the steady-state analytical solutions of the tetrachloroethene (PCE) serial degradation pathway and secondly on the analytical solutions of the parallel degradation pathway. The solutions in this study can also be applied to other types of dual domain systems with distinct flow and transport properties. The steady-state analytical solutions are shown to be accurate and the numerical program RT3D is selected for comparison. The results of this study are novel in that the solutions provide improved modeling flexibility including: 1) every species can have unique first-order reaction rates and unique retardation factors, and 2) daughter species can be modeled with their individual input concentrations or solely as byproducts of the parent species. The steady-state analytical solutions exhibit a limitation that occurs when interspecies reaction rate factors equal each other, which result in undefined solutions. Excel spreadsheet programs were created to facilitate prompt application of the steady-state analytical solutions, for both the serial and parallel degradation pathways.

Impact of postmastectomy radiotherapy in T3N0 invasive carcinoma of the breast: a Surveillance, Epidemiology, and End Results database analysis.

PubMed

McCammon, Robert; Finlayson, Christina; Schwer, Amanda; Rabinovitch, Rachel

2008-08-15

Randomized trials provide evidence for improved outcomes with postmastectomy radiotherapy (PMRT) in high-risk patients. It has been suggested that patients with T3N0 breast cancer represent a favorable subgroup for which PMRT renders little benefit. In the current study, the authors used a United States population database to evaluate PMRT in this subgroup. The cause-specific survival (CSS) and overall survival (OS) of women with T3N0M0 breast cancer in the Surveillance, Epidemiology, and End Results database after mastectomy and axillary staging from 1988 to 2002 were analyzed. Univariate analysis was performed to relate CSS with PMRT (yes vs no), tumor size (< or =7 cm vs >7 cm), grade (1 vs 2 or 3), patient age (< or =50 years vs >50 years), the number of lymph nodes dissected (< or =13 vs >13), and the era treated (1988-1997 vs 1998-2002). Multivariate analyses for CSS and OS were also performed. In total, 1865 women met the analysis criteria for OS; CSS data were available for 98.8% of those women. Of the women who were diagnosed during the era from 1988 to 1997, 22% received PMRT, and that rate increased to 41% during the era from 1998 to 2002. The actuarial 10-year CSS for those who received PMRT versus those who did not receive PMRT was 81.6% versus 79.8%, respectively (P = .38). PMRT was not associated with a CSS benefit in any subgroup, a finding that persisted in multivariate analyses. Women who received PMRT had an increased 10-year OS rate (70.7% vs 58.4%; P < .001) that was confined to women aged >50 years in a subgroup analysis. This retrospective, population-based analysis demonstrated no increase in CSS with PMRT for women with T3N0 breast cancer, lending further support to the hypothesis that T3N0 disease postmastectomy represents a favorable subset of locally advanced breast cancer. The increased OS associated with PMRT in the absence of improved CSS likely reflects patient selection in this nonrandomized dataset. Prospective evaluation of PMRT in this population subset is warranted. 2008 American Cancer Society

Overview of the 1994 chronic HT release experiment at Chalk River

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davis, P.A.; Workman, W.J.G.; Amiro, B.D.

1995-10-01

Trace amounts of tritiated hydrogen (HT) were released continuously to the atmosphere at Chalk River Laboratories over the 12-day period 1994 July 27 to August 8. Scientists from eight institutions in four countries took extensive air, soil and vegetation samples to study the dynamics of tritiated water (HTO) and organically-bound tritium (OBT) formation, and the environmental concentrations of these compounds at steady-state. The short-term HT air concentrations varied strongly in time and space over the test area, but the variation decreased rapidly as the averaging time increased. HTO concentrations in soil, vegetation and air built up gradually over time butmore » they fluctuated substantially with ambient meteorological conditions, particularly rainfall. OBT concentrations in plants increased throughout the period. HTO concentrations were at or near steady-state at the end of the release, but OBT levels were continuing to rise. 8 refs., 2 figs., 1 tab.« less

Time density curve analysis for C-arm FDCT PBV imaging.

PubMed

Kamran, Mudassar; Byrne, James V

2016-04-01

Parenchymal blood volume (PBV) estimation using C-arm flat detector computed tomography (FDCT) assumes a steady-state contrast concentration in cerebral vasculature for the scan duration. Using time density curve (TDC) analysis, we explored if the steady-state assumption is met for C-arm CT PBV scans, and how consistent the contrast-material dynamics in cerebral vasculature are across patients. Thirty C-arm FDCT datasets of 26 patients with aneurysmal-SAH, acquired as part of a prospective study comparing C-arm CT PBV with MR-PWI, were analysed. TDCs were extracted from the 2D rotational projections. Goodness-of-fit of TDCs to a steady-state horizontal-line-model and the statistical similarity among the individual TDCs were tested. Influence of the differences in TDC characteristics on the agreement of resulting PBV measurements with MR-CBV was calculated. Despite identical scan parameters and contrast-injection-protocol, the individual TDCs were statistically non-identical (p < 0.01). Using Dunn's multiple comparisons test, of the total 435 individual comparisons among the 30 TDCs, 330 comparisons (62%) reached statistical significance for difference. All TDCs deviated significantly (p < 0.01) from the steady-state horizontal-line-model. PBV values of those datasets for which the TDCs showed largest deviations from the steady-state model demonstrated poor agreement and correlation with MR-CBV, compared with the PBV values of those datasets for which the TDCs were closer to steady-state. For clinical C-arm CT PBV examinations, the administered contrast material does not reach the assumed 'ideal steady-state' for the duration of scan. Using a prolonged injection protocol, the degree to which the TDCs approximate the ideal steady-state influences the agreement of resulting PBV measurements with MR-CBV. © The Author(s) 2016.

An in vitro approach for prioritization and evaluation of chemical effects on glucocorticoid receptor mediated adipogenesis.

PubMed

Hartman, Jessica K; Beames, Tyler; Parks, Bethany; Doheny, Daniel; Song, Gina; Efremenko, Alina; Yoon, Miyoung; Foley, Briana; Deisenroth, Chad; McMullen, Patrick D; Clewell, Rebecca A

2018-05-18

Rising obesity rates worldwide have socio-economic ramifications. While genetics, diet, and lack of exercise are major contributors to obesity, environmental factors may enhance susceptibility through disruption of hormone homeostasis and metabolic processes. The obesogen hypothesis contends that chemical exposure early in development may enhance adipocyte differentiation, thereby increasing the number of adipocytes and predisposing for obesity and metabolic disease. We previously developed a primary human adipose stem cell (hASC) assay to evaluate the effect of environmental chemicals on PPARG-dependent adipogenesis. Here, the assay was modified to determine the effects of chemicals on the glucocorticoid receptor (GR) pathway. In differentiation cocktail lacking the glucocorticoid agonist dexamethasone (DEX), hASCs do not differentiate into adipocytes. In the presence of GR agonists, adipocyte maturation was observed using phenotypic makers for lipid accumulation, adipokine secretion, and expression of key genes. To evaluate the role of environmental compounds on adipocyte differentiation, progenitor cells were treated with 19 prioritized compounds previously identified by ToxPi as having GR-dependent bioactivity, and multiplexed assays were used to confirm a GR-dependent mode of action. Five chemicals were found to be strong agonists. The assay was also modified to evaluate GR-antagonists, and 8/10 of the hypothesized antagonists inhibited adipogenesis. The in vitro bioactivity data was put into context with extrapolated human steady state concentrations (Css) and clinical exposure data (Cmax). These data support using a human adipose-derived stem cell differentiation assay to test the potential of chemicals to alter human GR-dependent adipogenesis. Copyright © 2017. Published by Elsevier Inc.

Quantifying stream nutrient uptake from ambient to saturation with instantaneous tracer additions

NASA Astrophysics Data System (ADS)

Covino, T. P.; McGlynn, B. L.; McNamara, R.

2009-12-01

Stream nutrient tracer additions and spiraling metrics are frequently used to quantify stream ecosystem behavior. However, standard approaches limit our understanding of aquatic biogeochemistry. Specifically, the relationship between in-stream nutrient concentration and stream nutrient spiraling has not been characterized. The standard constant rate (steady-state) approach to stream spiraling parameter estimation, either through elevating nutrient concentration or adding isotopically labeled tracers (e.g. 15N), provides little information regarding the stream kinetic curve that represents the uptake-concentration relationship analogous to the Michaelis-Menten curve. These standard approaches provide single or a few data points and often focus on estimating ambient uptake under the conditions at the time of the experiment. Here we outline and demonstrate a new method using instantaneous nutrient additions and dynamic analyses of breakthrough curve (BTC) data to characterize the full relationship between spiraling metrics and nutrient concentration. We compare the results from these dynamic analyses to BTC-integrated, and standard steady-state approaches. Our results indicate good agreement between these three approaches but we highlight the advantages of our dynamic method. Specifically, our new dynamic method provides a cost-effective and efficient approach to: 1) characterize full concentration-spiraling metric curves; 2) estimate ambient spiraling metrics; 3) estimate Michaelis-Menten parameters maximum uptake (Umax) and the half-saturation constant (Km) from developed uptake-concentration kinetic curves, and; 4) measure dynamic nutrient spiraling in larger rivers where steady-state approaches are impractical.

Sulfur formation by steady-state continuous cultures of a sulfoxidizing consortium and Thiobacillus thioparus ATCC 23645.

PubMed

Alcántara, S; Velasco, A; Revah, S

2004-10-01

The elemental sulfur formation by the partial oxidation of thiosulfate by both a sulfoxidizing consortium and by Thiobacillus thioparus ATCC 23645 was studied under aerobic conditions in chemostat. Steady state was attained with essentially total conversion to sulfate when the dissolved oxygen concentration was 5 mgO2 l(-1) and below a dilution rate (D) of 3.0 d(-1)for the consortium and 0.9 d(-1) for T thioparus. The consortium formed elemental sulfur in steady state under oxygen limitation. Fifty percent of the theoretical elemental sulfur yield was obtained with a dissolved oxygen concentration of 0.2 mgO2 l(-1). Growth of T thioparus was negatively affected with a concentration below 1.9 mgO2 l(-1). Consortium yield from batch cultures was 2.1 g(-1) (protein) mol(-1) (thiosulfate), which was comparable with the values obtained in the chemostat at dilution rates of 0.4 d(-1) and 1.2 d(-1). The consortium showed a maximum degradation rate of 0.105 g(thiosulfate) g(-1) (protein) min(-1) and a saturation rate for S2O3(2-) of 1.9 mM.

Formation of magnetic discontinuities through viscous relaxation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, Sanjay; Bhattacharyya, R.; Smolarkiewicz, P. K.

2014-05-15

According to Parker's magnetostatic theorem, tangential discontinuities in magnetic field, or current sheets (CSs), are generally unavoidable in an equilibrium magnetofluid with infinite electrical conductivity and complex magnetic topology. These CSs are due to a failure of a magnetic field in achieving force-balance everywhere and preserving its topology while remaining in a spatially continuous state. A recent work [Kumar, Bhattacharyya, and Smolarkiewicz, Phys. Plasmas 20, 112903 (2013)] demonstrated this CS formation utilizing numerical simulations in terms of the vector magnetic field. The magnetohydrodynamic simulations presented here complement the above work by demonstrating CS formation by employing a novel approach ofmore » describing the magnetofluid evolution in terms of magnetic flux surfaces instead of the vector magnetic field. The magnetic flux surfaces being the possible sites on which CSs develop, this approach provides a direct visualization of the CS formation, helpful in understanding the governing dynamics. The simulations confirm development of tangential discontinuities through a favorable contortion of magnetic flux surfaces, as the magnetofluid undergoes a topology-preserving viscous relaxation from an initial non-equilibrium state with twisted magnetic field. A crucial finding of this work is in its demonstration of CS formation at spatial locations away from the magnetic nulls.« less

Steady-state plasma concentration profile of transdermal rotigotine: an integrated analysis of three, open-label, randomized, phase I multiple dose studies.

PubMed

Elshoff, Jan-Peer; Braun, Marina; Andreas, Jens-Otto; Middle, Michelle; Cawello, Willi

2012-04-01

The dopamine agonist rotigotine is formulated in a transdermal delivery system (patch) for once-daily application. It has been reported as efficacious in the treatment of idiopathic Parkinson's disease (PD) and restless legs syndrome. This article summarizes the results of 3 clinical studies conducted to characterize the 24-hour pharmacokinetic profile of rotigotine in steady state and the effect of different patch application sites on this profile. In addition, the relative bioavailability of a single, large patch versus 2 smaller patches was assessed. One Phase I study (SP871) assessed the steady-state pharmacokinetic properties at different application sites at a rotigotine maintenance dose of 3 mg/24 hours in healthy participants. Due to tolerability issues, the steady-state pharmacokinetic properties of rotigotine at higher doses (8 mg/24 hours) was assessed in 2 Phase I studies (SP630, SP651) in early-stage PD patients. Relative rotigotine bioavailability from a 40 cm(2) patch versus 2 × 20 cm(2) patches (SP651) and from a 15 cm(2) patch versus 1 × 5 cm(2) + 1 × 10 cm(2) patches (SP871) was also evaluated. Rotigotine concentrations in plasma were analyzed using a validated LC-MS/MS method. The pharmacokinetic variables were calculated using standard noncompartmental analysis. Release of rotigotine to the skin was 31% to 62% of total drug content in the patch. Variability of rotigotine exposure was low within participants (15%) compared with the variability observed between participants (54%). Rotigotine exposure increased proportionally in the therapeutic dose range of 2 mg/24 hours to 8 mg/24 hours. Plasma concentrations at steady state were stable over the 24-hour patch-on period. Delivery via a single, large patch compared with a combination of smaller patches did not appear to influence exposure to rotigotine. Bioavailability showed some variability depending on patch application site (hip, shoulder, abdomen, flank, thigh, upper arm); the respective mean ratios for AUC ranged between 0.87 (abdomen vs flank) and 1.46 (shoulder vs thigh). Continuous rotigotine delivery via a once-daily transdermal patch generated stable mean steady-state 24-hour plasma concentrations in healthy participants as well as patients with early-stage PD. Doses were achieved either by application of 1 large patch or a combination of smaller patches, resulting in the same total surface area. Copyright © 2012 Elsevier HS Journals, Inc. All rights reserved.

Indirect MRI of 17 o-labeled water using steady-state sequences: Signal simulation and preclinical experiment.

PubMed

Kudo, Kohsuke; Harada, Taisuke; Kameda, Hiroyuki; Uwano, Ikuko; Yamashita, Fumio; Higuchi, Satomi; Yoshioka, Kunihiro; Sasaki, Makoto

2018-05-01

Few studies have been reported for T 2 -weighted indirect 17 O imaging. To evaluate the feasibility of steady-state sequences for indirect 17 O brain imaging. Signal simulation, phantom measurements, and prospective animal experiments were performed in accordance with the institutional guidelines for animal experiments. Signal simulations of balanced steady-state free precession (bSSFP) were performed for concentrations of 17 O ranging from 0.037-1.600%. Phantom measurements with concentrations of 17 O water ranging from 0.037-1.566% were also conducted. Six healthy beagle dogs were scanned with intravenous administration of 20% 17 O-labeled water (1 mL/kg). Dynamic 3D-bSSFP scans were performed at 3T MRI. 17 O-labeled water was injected 60 seconds after the scan start, and the total scan duration was 5 minutes. Based on the result of signal simulation and phantom measurement, signal changes in the beagle dogs were measured and converted into 17 O concentrations. The 17 O concentrations were averaged for every 15 seconds, and compared to the baseline (30-45 sec) with Dunnett's multiple comparison tests. Signal simulation revealed that the relationships between 17 O concentration and the natural logarithm of relative signals were linear. The intraclass correlation coefficient between relative signals in phantom measurement and signal simulations was 0.974. In the animal experiments, significant increases in 17 O concentration (P < 0.05) were observed 60 seconds after the injection of 17 O. At the end of scanning, mean respective 17 O concentrations of 0.084 ± 0.026%, 0.117 ± 0.038, 0.082 ± 0.037%, and 0.049 ± 0.004% were noted for the cerebral cortex, cerebellar cortex, cerebral white matter, and ventricle. Dynamic steady-state sequences were feasible for indirect 17 O imaging, and absolute quantification was possible. This method can be applied for the measurement of permeability and blood flow in the brain, and for kinetic analysis of cerebrospinal fluid. 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;47:1373-1379. © 2017 International Society for Magnetic Resonance in Medicine.

Concentration polarization of hyaluronan on the surface of the synovial lining of infused joints

PubMed Central

Lu, Y; Levick, JR; Wang, W

2004-01-01

Hyaluronan (HA) in joints conserves the lubricating synovial fluid by making trans-synovial fluid escape almost insensitive to pressure elevation (e.g. effusions, joint flexion). This phenomenon, ‘outflow buffering’, was discovered during HA infusion into the rabbit knee joint cavity. It was also found that HA is partially reflected by the joint lining (molecular sieving), and that the reflected fraction R decreases as trans-synovial filtration rate Q is increased. It was postulated therefore that outflow buffering is mediated by HA reflection. Reflection creates a HA concentration polarization layer, the osmotic pressure of which opposes fluid loss. A steady-state, cross-flow ultrafiltration model was previously used to explain the outflow buffering and negative R-vs.-Q relation. However, the steady-state, cross-perfusion assumptions restricted the model's applicability for an infused, dead-end cavity or a non-infused joint during cyclical motion. We therefore developed a new, non-steady-state model which describes the time course of dead-end, partial HA ultrafiltration. The model describes the progressive build-up of a HA concentration polarization layer at the synovial surface over time. Using experimental parameter values, the model successfully accounts for the observed negative R-vs.-Q relation and shows that the HA reflected fraction (R) also depends on HA diffusivity, membrane area expansion and the synovial HA reflection coefficient. The non-steady-state model thus explains existing experimental work, and it is a key stage in understanding synovial fluid turnover in intact, moving, human joints or osteoarthritic joints treated by HA injections. PMID:15579541

Pre-steady-state DNA unwinding by bacteriophage T4 Dda helicase reveals a monomeric molecular motor.

PubMed

Nanduri, Bindu; Byrd, Alicia K; Eoff, Robert L; Tackett, Alan J; Raney, Kevin D

2002-11-12

Helicases are molecular motor enzymes that unwind and translocate nucleic acids. One of the central questions regarding helicase activity is whether the process of coupling ATP hydrolysis to DNA unwinding requires an oligomeric form of the enzyme. We have applied a pre-steady-state kinetics approach to address this question with the bacteriophage T4 Dda helicase. If a helicase can function as a monomer, then the burst amplitude in the pre-steady state might be similar to the concentration of enzyme, whereas if the helicase required oligomerization, then the amplitude would be significantly less than the enzyme concentration. DNA unwinding of an oligonucleotide substrate was conducted by using a Kintek rapid quench-flow instrument. The substrate consisted of 12 bp adjacent to 12 nucleotides of single-stranded DNA. Dda (4 nM) was incubated with substrate (16 nM) in buffer, and the unwinding reaction was initiated by the addition of ATP (5 mM) and Mg(2+) (10 mM). The reaction was stopped by the addition of 400 mM EDTA. Product formation exhibited biphasic kinetics, and the data were fit to the equation for a single exponential followed by a steady state. The amplitude of the first phase was 3.5 +/- 0.2 nM, consistent with a monomeric helicase. The burst amplitude of product formation was measured over a range of enzyme and substrate concentrations and remained consistent with a functional monomer. Thus, Dda can rapidly unwind oligonucleotide substrates as a monomer, indicating that the functional molecular motor component of a helicase can reside within a single polypeptide.

Time density curve analysis for C-arm FDCT PBV imaging

PubMed Central

Byrne, James V

2016-01-01

Introduction Parenchymal blood volume (PBV) estimation using C-arm flat detector computed tomography (FDCT) assumes a steady-state contrast concentration in cerebral vasculature for the scan duration. Using time density curve (TDC) analysis, we explored if the steady-state assumption is met for C-arm CT PBV scans, and how consistent the contrast-material dynamics in cerebral vasculature are across patients. Methods Thirty C-arm FDCT datasets of 26 patients with aneurysmal-SAH, acquired as part of a prospective study comparing C-arm CT PBV with MR-PWI, were analysed. TDCs were extracted from the 2D rotational projections. Goodness-of-fit of TDCs to a steady-state horizontal-line-model and the statistical similarity among the individual TDCs were tested. Influence of the differences in TDC characteristics on the agreement of resulting PBV measurements with MR-CBV was calculated. Results Despite identical scan parameters and contrast-injection-protocol, the individual TDCs were statistically non-identical (p < 0.01). Using Dunn's multiple comparisons test, of the total 435 individual comparisons among the 30 TDCs, 330 comparisons (62%) reached statistical significance for difference. All TDCs deviated significantly (p < 0.01) from the steady-state horizontal-line-model. PBV values of those datasets for which the TDCs showed largest deviations from the steady-state model demonstrated poor agreement and correlation with MR-CBV, compared with the PBV values of those datasets for which the TDCs were closer to steady-state. Conclusion For clinical C-arm CT PBV examinations, the administered contrast material does not reach the assumed ‘ideal steady-state’ for the duration of scan. Using a prolonged injection protocol, the degree to which the TDCs approximate the ideal steady-state influences the agreement of resulting PBV measurements with MR-CBV. PMID:26769736

Lactate and Acrylate Metabolism by Megasphaera elsdenii under Batch and Steady-State Conditions

PubMed Central

Prabhu, Rupal; Altman, Elliot

2012-01-01

The growth of Megasphaera elsdenii on lactate with acrylate and acrylate analogues was studied under batch and steady-state conditions. Under batch conditions, lactate was converted to acetate and propionate, and acrylate was converted into propionate. Acrylate analogues 2-methyl propenoate and 3-butenoate containing a terminal double bond were similarly converted into their respective saturated acids (isobutyrate and butyrate), while crotonate and lactate analogues 3-hydroxybutyrate and (R)-2-hydroxybutyrate were not metabolized. Under carbon-limited steady-state conditions, lactate was converted to acetate and butyrate with no propionate formed. As the acrylate concentration in the feed was increased, butyrate and hydrogen formation decreased and propionate was increasingly generated, while the calculated ATP yield was unchanged. M. elsdenii metabolism differs substantially under batch and steady-state conditions. The results support the conclusion that propionate is not formed during lactate-limited steady-state growth because of the absence of this substrate to drive the formation of lactyl coenzyme A (CoA) via propionyl-CoA transferase. Acrylate and acrylate analogues are reduced under both batch and steady-state growth conditions after first being converted to thioesters via propionyl-CoA transferase. Our findings demonstrate the central role that CoA transferase activity plays in the utilization of acids by M. elsdenii and allows us to propose a modified acrylate pathway for M. elsdenii. PMID:23023753

Prospective evaluation of haemoglobin oxygen saturation at rest and after exercise in paediatric sickle cell disease patients

PubMed Central

Campbell, Andrew; Minniti, Caterina P.; Nouraie, Mehdi; Arteta, Manuel; Rana, Sohail; Onyekwere, Onyinye; Sable, Craig; Ensing, Gregory; Dham, Niti; Luchtman-Jones, Lori; Kato, Gregory J.; Gladwin, Mark T.; Castro, Oswaldo L.; Gordeuk, Victor R.

2009-01-01

Summary Low steady state haemoglobin oxygen saturation in patients with sickle cell anaemia has been associated with the degree of anaemia and haemolysis. How much pulmonary dysfunction contributes to low saturation is not clear. In a prospective study of children and adolescents with sickle cell disease aged 3–20 years at steady state and matched controls, 52% of 391 patients versus 24% of 63 controls had steady state oxygen saturation <99% (P < 0·0001), 9% of patients versus no controls had saturation <95% (P = 0·008) and 8% of patients versus no controls had exercise-induced reduction in saturation ≥3%. Decreasing haemoglobin concentration (P ≤ 0·001) and increasing haemolysis (P ≤ 0·003) but not pulmonary function tests were independent predictors of both lower steady-state saturation and exercise-induced reduction in saturation. Neither history of stroke nor history of acute chest syndrome was significantly associated with lower steady-state oxygen saturation or exercise-induced reduction in saturation. Tricuspid regurgitation velocity was higher in patients with lower steady state haemoglobin oxygen saturation (P = 0·003) and with greater decline in oxygen saturation during the six-minute walk (P = 0·022). In conclusion, lower haemoglobin oxygen saturation is independently associated with increasing degrees of anaemia and haemolysis but not pulmonary function abnormalities among children and adolescents with sickle cell disease. PMID:19694721

Drivers of Seasonal Variability in Marine Boundary Layer Aerosol Number Concentration Investigated Using a Steady State Approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mohrmann, Johannes; Wood, Robert; McGibbon, Jeremy

Marine boundary layer (MBL) aerosol particles affect the climate through their interaction with MBL clouds. Although both MBL clouds and aerosol particles have pronounced seasonal cycles, the factors controlling seasonal variability of MBL aerosol particle concentration are not well-constrained. In this paper an aerosol budget is constructed representing the effects of wet deposition, free-tropospheric entrainment, primary surface sources, and advection on the MBL accumulation mode aerosol number concentration (N a). These terms are further parameterized, and by assuming that on seasonal timescales N a is in steady state, the budget equation is rearranged to form a diagnostic equation for Nmore » a based on observable variables. Using data primarily collected in the subtropical northeast Pacific during the MAGIC campaign (Marine ARM (Atmospheric Radiation Measurement) GPCI (GCSS Pacific Cross-section Intercomparison) Investigation of Clouds), estimates of both mean summer and winter N a concentrations are made using the simplified steady-state model and seasonal mean observed variables, and are found to match well with the observed N a. To attribute the modeled difference between summer and winter aerosol concentrations to individual observed variables (e.g. precipitation rate, free-tropospheric aerosol number concentration), a local sensitivity analysis is combined with the seasonal difference in observed variables. This analysis shows that despite wintertime precipitation frequency being lower than summer, the higher winter precipitation rate accounted for approximately 60% of the modeled seasonal difference in N a, which emphasizes the importance of marine stratocumulus precipitation in determining MBL aerosol concentrations on longer time scales.« less

Drivers of Seasonal Variability in Marine Boundary Layer Aerosol Number Concentration Investigated Using a Steady State Approach

DOE PAGES

Mohrmann, Johannes; Wood, Robert; McGibbon, Jeremy; ...

2018-01-21

Marine boundary layer (MBL) aerosol particles affect the climate through their interaction with MBL clouds. Although both MBL clouds and aerosol particles have pronounced seasonal cycles, the factors controlling seasonal variability of MBL aerosol particle concentration are not well-constrained. In this paper an aerosol budget is constructed representing the effects of wet deposition, free-tropospheric entrainment, primary surface sources, and advection on the MBL accumulation mode aerosol number concentration (N a). These terms are further parameterized, and by assuming that on seasonal timescales N a is in steady state, the budget equation is rearranged to form a diagnostic equation for Nmore » a based on observable variables. Using data primarily collected in the subtropical northeast Pacific during the MAGIC campaign (Marine ARM (Atmospheric Radiation Measurement) GPCI (GCSS Pacific Cross-section Intercomparison) Investigation of Clouds), estimates of both mean summer and winter N a concentrations are made using the simplified steady-state model and seasonal mean observed variables, and are found to match well with the observed N a. To attribute the modeled difference between summer and winter aerosol concentrations to individual observed variables (e.g. precipitation rate, free-tropospheric aerosol number concentration), a local sensitivity analysis is combined with the seasonal difference in observed variables. This analysis shows that despite wintertime precipitation frequency being lower than summer, the higher winter precipitation rate accounted for approximately 60% of the modeled seasonal difference in N a, which emphasizes the importance of marine stratocumulus precipitation in determining MBL aerosol concentrations on longer time scales.« less

Drivers of Seasonal Variability in Marine Boundary Layer Aerosol Number Concentration Investigated Using a Steady State Approach

NASA Astrophysics Data System (ADS)

Mohrmann, Johannes; Wood, Robert; McGibbon, Jeremy; Eastman, Ryan; Luke, Edward

2018-01-01

Marine boundary layer (MBL) aerosol particles affect the climate through their interaction with MBL clouds. Although both MBL clouds and aerosol particles have pronounced seasonal cycles, the factors controlling seasonal variability of MBL aerosol particle concentration are not well constrained. In this paper an aerosol budget is constructed representing the effects of wet deposition, free-tropospheric entrainment, primary surface sources, and advection on the MBL accumulation mode aerosol number concentration (Na). These terms are then parameterized, and by assuming that on seasonal time scales Na is in steady state, the budget equation is rearranged to form a diagnostic equation for Na based on observable variables. Using data primarily collected in the subtropical northeast Pacific during the MAGIC campaign (Marine ARM (Atmospheric Radiation Measurement) GPCI (GCSS Pacific Cross-Section Intercomparison) Investigation of Clouds), estimates of both mean summer and winter Na concentrations are made using the simplified steady state model and seasonal mean observed variables. These are found to match well with the observed Na. To attribute the modeled difference between summer and winter aerosol concentrations to individual observed variables (e.g., precipitation rate and free-tropospheric aerosol number concentration), a local sensitivity analysis is combined with the seasonal difference in observed variables. This analysis shows that despite wintertime precipitation frequency being lower than summer, the higher winter precipitation rate accounted for approximately 60% of the modeled seasonal difference in Na, which emphasizes the importance of marine stratocumulus precipitation in determining MBL aerosol concentrations on longer time scales.

Cardiac involvement in ANCA (+) and ANCA (-) Churg-Strauss syndrome evaluated by cardiovascular magnetic resonance.

PubMed

Mavrogeni, Sophie; Karabela, Georgia; Gialafos, Elias; Stavropoulos, Efthymios; Spiliotis, George; Katsifis, Gikas; Kolovou, Genovefa

2013-10-01

The cardiovascular magnetic resonance (CMR) pattern of Churg-Strauss syndrome (CSS) includes myopericarditis, diffuse subendocardial vasculitis or myocardial infarction with or without cardiac symptoms and is usually associated with lack of antineutrophil cytoplasmic antibodies (ANCA). To correlate the CMR pattern with ANCA in CSS, compare it with healthy controls and systemic lupus erythematosus (SLE) patients and re-evaluate 2 yrs after the first CMR. 28 consecutive CSS, aged 42±7 yrs, were referred for CMR and 2 yrs re-evaluation. The CMR included left ventricular ejection fraction (LVEF), T2-weighted (T2-W), early (EGE) and late gadolinium enhanced (LGE) imaging. Their results were compared with 28 systemic lupus erythematosus (SLE) under remission and 28 controls with normal myocardial perfusion, assessed by scintigraphy. CMR revealed acute cardiac lesions in all ANCA (-) CSS with active disease and acute cardiac symptoms and only in one asymptomatic ANCA (+) CSS, with active disease. Diffuse subendocardial fibrosis (DSF) or past myocarditis was identified in both ANCA(+) and ANCA (-) CSS, but with higher incidence and fibrosis amount in ANCA (-) CSS (p<0.05). In comparison to SLE, both ANCA (+) and ANCA (-) CSS had higher incidence of DSF, lower incidence of myocarditis and no evidence of myocardial infarction, due to coronary artery disease (p<0.05). In 2 yrs CMR follow up, 1/3 of CSS with DSF presented LV function deterioration and one died, although immunosuppressive treatment was given early after CSS diagnosis. Cardiac involvement either as DSF or myocarditis, can be detected in both ANCA (+) and ANCA (-) CSS, although more clinically overt in ANCA (-). DSF carries an ominous prognosis for LV function. CMR, due to its capability to detect disease severity, before cardiac dysfunction takes place, is an excellent tool for CSS risk stratification and treatment individualization.

Cortical Superficial Siderosis in Different Types of Cerebral Small Vessel Disease.

PubMed

Wollenweber, Frank Arne; Baykara, Ebru; Zedde, Marialuisa; Gesierich, Benno; Achmüller, Melanie; Jouvent, Eric; Viswanathan, Anand; Ropele, Stefan; Chabriat, Hugues; Schmidt, Reinhold; Opherk, Christian; Dichgans, Martin; Linn, Jennifer; Duering, Marco

2017-05-01

Cortical superficial siderosis (cSS) has emerged as a clinically relevant imaging feature of cerebral amyloid angiopathy (CAA). However, it remains unknown whether cSS is also present in nonamyloid-associated small vessel disease and whether patients with cSS differ in terms of other small vessel disease imaging features. Three hundred sixty-four CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy) patients, 372 population-based controls, and 100 CAA patients with cSS (fulfilling the modified Boston criteria for possible/probable CAA) were included. cSS and cerebral microbleeds were visually rated on T2*-weighted magnetic resonance imaging. White matter hyperintensities were segmented on fluid-attenauted inversion recovery images, and their spatial distribution was compared between groups using colocalization analysis. Cerebral microbleeds location was determined in an observer-independent way using an atlas in standard space. cSS was absent in CADASIL and present in only 2 population-based controls (0.5%). Cerebral microbleeds were present in 64% of CAA patients with cSS, 34% of patients with CADASIL, and 12% of population-based controls. Among patients with cerebral microbleeds, lobar location was found in 95% of CAA patients with cSS, 48% of CADASIL patients, and 69% of population-based controls. The spatial distribution of white matter hyperintensities was comparable between CAA with cSS and CADASIL as indicated by high colocalization coefficients. cSS was absent in CADASIL, whereas other small vessel disease imaging features were similar to CAA patients with cSS. Our findings suggest that cSS in combination with other small vessel disease imaging markers is highly indicative of CAA. © 2017 American Heart Association, Inc.

Relating environmental availability to bioavailability: soil-type-dependent metal accumulation in the oligochaete Eisenia andrei.

PubMed

Peijnenburg, W J; Baerselman, R; de Groot, A C; Jager, T; Posthuma, L; Van Veen, R P

1999-11-01

Body residues are often better estimates of the amount of a chemical at the sites of toxic action in an organism than ambient soil concentrations, because bioavailability differences among soils are explicitly taken into account in considerations of body residues. Often, however, insufficient attention is paid to the rate and extent at which tissue concentrations respond to soil concentrations and soil characteristics. In this contribution the impact of soil characteristics on the environmental bioavailability of heavy metals for the oligochaete worm Eisenia andrei is reported. Uptake of As, Cd, Cr, Cu, Ni, Pb, and Zn in 20 Dutch field soils and in OECD artificial soil was quantified as a function of time. Internal metal concentrations varied less than the corresponding external levels. Metal uptake and elimination were both metal- and species-dependent. Worms typically attained steady-state concentrations rapidly for Cr, Cu, Ni, and Zn. Internal concentrations similar to those in the cultivation medium, linearly increasing body concentrations, or steady-state internal concentrations well above those in the cultivation medium were found for As, Cd, and Pb. Multivariate expressions were derived to describe uptake rate constants, steady-state concentrations, and bioaccumulation factors as a function of soil characteristics. Soil acidity is the most important solid-phase characteristic modulating the availability of As, Cd, and Pb. Although additional semimechanistic calculations yielded evidence of pore-water-related uptake of Cd and Pb modulated by competition between H(+) and metal ions at the active sites of the membranes, the findings for Cr, Cu, Ni, and Zn point to additional influences, among which is probably regulation. Copyright 1999 Academic Press.

The role of surface generated radicals in catalytic combustion

NASA Technical Reports Server (NTRS)

Santavicca, D. A.; Stein, Y.; Royce, B. S. H.

1985-01-01

Experiments were conducted to better understand the role of catalytic surface reactions in determining the ignition characteristics of practical catalytic combustors. Hydrocarbon concentrations, carbon monoxide and carbon dioxide concentrations, hydroxyl radical concentrations, and gas temperature were measured at the exit of a platinum coated, stacked plate, catalytic combustor during the ignition of lean propane-air mixtures. The substrate temperature profile was also measured during the ignition transient. Ignition was initiated by suddenly turning on the fuel and the time to reach steady state was of the order of 10 minutes. The gas phase reaction, showed no pronounced effect due to the catalytic surface reactions, except the absence of a hydroxyl radical overshoot. It is found that the transient ignition measurements are valuable in understanding the steady state performance characteristics.

Subarachnoid and Intracerebral Hemorrhage in Patients with Churg-Strauss Syndrome: Two Case Reports

PubMed Central

Go, Myeong Hoon; Park, Jeong Un; Kang, Jae Gyu

2012-01-01

Churg-Strauss syndrome (CSS) is a systemic necrotizing vasculitis of the small and medium vessels, associated with extravascular eosinophilic granulomas, peripheral eosinophilia, and asthma. The exact etiology of CSS is unknown. This syndrome commonly affects the lungs, peripheral nerves, skin, heart, and gastrointestinal tract, but rarely the central nervous system. Subarachnoid and intracerebral hemorrhage in CSS patients is extremely rare; however, clinicians should consider that CSS may be a cause of intracranial hemorrhage and its high rate of mortality and morbidity. The authors report on two cases of subarachnoid and intracerebral hemorrhage with CSS and discuss a brief review of CSS. PMID:23210058

Evaluation of cytotoxicity and antimicrobial activity of Acticoat Burn Dressing for management of microbial contamination in cultured skin substitutes grafted to athymic mice.

PubMed

Supp, Andrew P; Neely, Alice N; Supp, Dorothy M; Warden, Glenn D; Boyce, Steven T

2005-01-01

Cultured skin substitutes (CSS) have become a useful adjunctive treatment for closure of burn wounds, but CSS are avascular and remain susceptible to microbial destruction longer than split-thickness skin grafts. Irrigation of CSS grafted to burn wounds with a topical antimicrobial solution (TAS) has been shown to promote engraftment of CSS, but TAS usage has potential limitations. Acticoat Burn Dressing (Acticoat; Westaim Biomedical, Exeter, NH) is a silver-coated barrier dressing reported to exhibit antimicrobial activity and to reduce infection in partial-thickness and full-thickness wounds. This study evaluated the cytotoxicity of Acticoat with CSS and the efficacy of Acticoat for the management of microbial contamination in CSS grafted to full-thickness wounds in athymic mice. The cytotoxicity of Acticoat was assessed in preliminary studies after 1 week of exposure to CSS during in vitro maturation or healing on wounds in athymic mice. Histologies were analyzed and cellular viability in the CSS was determined by MTT conversion on days 0, 1, and 7 of Acticoat exposure. At 1, 2, 3, and 4 weeks after grafting, wounds were traced, and areas of healing CSS were calculated by image analysis. At 4 weeks, wound biopsies were evaluated and scored for engraftment of human cells. In a subsequent study, wounds were inoculated with strain SBI-N of Pseudomonas aeruginosa at 1 x 10(5) cfu/wound before the application of CSS or inoculated onto the surface of Acticoat. At 4 weeks, swab cultures were collected from the surface of CSS and scored for the presence of SBI-N. Statistical significance was accepted at the 95% confidence level (P <.05). The data show that exposure in vitro of CSS to Acticoat was cytotoxic within 1 day, but 1 week of exposure in vivo did not injure CSS or inhibit wound healing. Contaminated wounds treated with Acticoat healed similarly to control treatments, with comparable rates of engraftment, and detection of SBI-N on the surface of only one graft. No SBI-N was detected on CSS after inoculation onto the surface of Acticoat. These results suggest that Acticoat may be suitable as a protective dressing to reduce environmental contamination of CSS, if used in conjunction with additional antimicrobials to control organisms present in the wound.

Functional Role of N- and C-Terminal Amino Acids in the Structural Subunits of Colonization Factor CS6 Expressed by Enterotoxigenic Escherichia coli

PubMed Central

Debnath, Anusuya; Sabui, Subrata; Wajima, Takeaki; Hamabata, Takashi; Banerjee, Rajat

2016-01-01

ABSTRACT CS6 is a common colonization factor expressed by enterotoxigenic Escherichia coli. It is a two-subunit protein consisting of CssA and CssB in an equal stoichiometry, assembled via the chaperone-usher pathway into an afimbrial, oligomeric assembly on the bacterial cell surface. A recent structural study has predicted the involvement of the N- and C-terminal regions of the CS6 subunits in its assembly. Here, we identified the functionally important residues in the N- and C-terminal regions of the CssA and CssB subunits during CS6 assembly by alanine scanning mutagenesis. Bacteria expressing mutant proteins were tested for binding with Caco-2 cells, and the results were analyzed with respect to the surface expression of mutant CS6. In this assay, many mutant proteins were not expressed on the surface while some showed reduced expression. It appeared that some, but not all, of the residues in both the N and C termini of CssA and CssB played an important role in the intermolecular interactions between these two structural subunits, as well as chaperone protein CssC. Our results demonstrated that T20, K25, F27, S36, Y143, and V147 were important for the stability of CssA, probably through interaction of CssC. We also found that I22, V29, and I33 of CssA and G154, Y156, L160, V162, F164, and Y165 of CssB were responsible for CssA-CssB intermolecular interactions. In addition, some of the hydrophobic residues in the C terminus of CssA and the N terminus of CssB were involved in the stabilization of higher-order complex formation. Overall, the results presented here might help in understanding the pathway used to assemble CS6 and predict its structure. IMPORTANCE Unlike most other colonization factors, CS6 is nonfimbrial, and in a sense, its subunit composition and assembly are also unique. Here we report that both the N- and C-terminal amino acid residues of CssA and CssB play a critical role in the intermolecular interactions between them and assembly proteins. We found mainly that alternate hydrophobic residues present in these motifs are essential for the interaction between the structural subunits, as well as the chaperone and usher assembly proteins. Our results indicate the involvement of the side chains of identified amino acids in CS6 assembly. This study adds a step toward understanding the interactions between structural subunits of CS6 and assembly proteins during CS6 biogenesis. PMID:26929298

Improving color constancy by discounting the variation of camera spectral sensitivity

NASA Astrophysics Data System (ADS)

Gao, Shao-Bing; Zhang, Ming; Li, Chao-Yi; Li, Yong-Jie

2017-08-01

It is an ill-posed problem to recover the true scene colors from a color biased image by discounting the effects of scene illuminant and camera spectral sensitivity (CSS) at the same time. Most color constancy (CC) models have been designed to first estimate the illuminant color, which is then removed from the color biased image to obtain an image taken under white light, without the explicit consideration of CSS effect on CC. This paper first studies the CSS effect on illuminant estimation arising in the inter-dataset-based CC (inter-CC), i.e., training a CC model on one dataset and then testing on another dataset captured by a distinct CSS. We show the clear degradation of existing CC models for inter-CC application. Then a simple way is proposed to overcome such degradation by first learning quickly a transform matrix between the two distinct CSSs (CSS-1 and CSS-2). The learned matrix is then used to convert the data (including the illuminant ground truth and the color biased images) rendered under CSS-1 into CSS-2, and then train and apply the CC model on the color biased images under CSS-2, without the need of burdensome acquiring of training set under CSS-2. Extensive experiments on synthetic and real images show that our method can clearly improve the inter-CC performance for traditional CC algorithms. We suggest that by taking the CSS effect into account, it is more likely to obtain the truly color constant images invariant to the changes of both illuminant and camera sensors.

Chamber measurement of surface-atmosphere trace gas exchange: Numerical evaluation of dependence on soil, interfacial layer, and source/sink properties

NASA Astrophysics Data System (ADS)

Hutchinson, G. L.; Livingston, G. P.; Healy, R. W.; Striegl, R. G.

2000-04-01

We employed a three-dimensional finite difference gas diffusion model to simulate the performance of chambers used to measure surface-atmosphere trace gas exchange. We found that systematic errors often result from conventional chamber design and deployment protocols, as well as key assumptions behind the estimation of trace gas exchange rates from observed concentration data. Specifically, our simulations showed that (1) when a chamber significantly alters atmospheric mixing processes operating near the soil surface, it also nearly instantaneously enhances or suppresses the postdeployment gas exchange rate, (2) any change resulting in greater soil gas diffusivity, or greater partitioning of the diffusing gas to solid or liquid soil fractions, increases the potential for chamber-induced measurement error, and (3) all such errors are independent of the magnitude, kinetics, and/or distribution of trace gas sources, but greater for trace gas sinks with the same initial absolute flux. Finally, and most importantly, we found that our results apply to steady state as well as non-steady-state chambers, because the slow rate of gas diffusion in soil inhibits recovery of the former from their initial non-steady-state condition. Over a range of representative conditions, the error in steady state chamber estimates of the trace gas flux varied from -30 to +32%, while estimates computed by linear regression from non-steady-state chamber concentrations were 2 to 31% too small. Although such errors are relatively small in comparison to the temporal and spatial variability characteristic of trace gas exchange, they bias the summary statistics for each experiment as well as larger scale trace gas flux estimates based on them.

Adsorption and biodegradation of 2-chlorophenol by mixed culture using activated carbon as a supporting medium-reactor performance and model verification

NASA Astrophysics Data System (ADS)

Lin, Yen-Hui

2017-11-01

A non-steady-state mathematical model system for the kinetics of adsorption and biodegradation of 2-chlorophenol (2-CP) by attached and suspended biomass on activated carbon process was derived. The mechanisms in the model system included 2-CP adsorption by activated carbon, 2-CP mass transport diffusion in biofilm, and biodegradation by attached and suspended biomass. Batch kinetic tests were performed to determine surface diffusivity of 2-CP, adsorption parameters for 2-CP, and biokinetic parameters of biomass. Experiments were conducted using a biological activated carbon (BAC) reactor system with high recycled rate to approximate a completely mixed flow reactor for model verification. Concentration profiles of 2-CP by model predictions indicated that biofilm bioregenerated the activated carbon by lowering the 2-CP concentration at the biofilm-activated carbon interface as the biofilm grew thicker. The removal efficiency of 2-CP by biomass was approximately 98.5% when 2-CP concentration in the influent was around 190.5 mg L-1 at a steady-state condition. The concentration of suspended biomass reached up to about 25.3 mg L-1 while the thickness of attached biomass was estimated to be 636 μm at a steady-state condition by model prediction. The experimental results agree closely with the results of the model predictions.

Whole-Pelvis Radiotherapy in Combination With Interstitial Brachytherapy: Does Coverage of the Pelvic Lymph Nodes Improve Treatment Outcome in High-Risk Prostate Cancer?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bittner, Nathan; Merrick, Gregory S., E-mail: gmerrick@UrologicResearchInstitute.or; Wallner, Kent E.

2010-03-15

Purpose: To compare biochemical progression-free survival (bPFS), cause-specific survival (CSS), and overall survival (OS) rates among high-risk prostate cancer patients treated with brachytherapy and supplemental external beam radiation (EBRT) using either a mini-pelvis (MP) or a whole-pelvis (WP) field. Methods and Materials: From May 1995 to October 2005, 186 high-risk prostate cancer patients were treated with brachytherapy and EBRT with or without androgen-deprivation therapy (ADT). High-risk prostate cancer was defined as a Gleason score of >=8 and/or a prostate-specific antigen (PSA) concentration of >=20 ng/ml. Results: With a median follow-up of 6.7 years, the 10-year bPFS, CSS, and OS ratesmore » for the WP vs. the MP arms were 91.7% vs. 84.4% (p = 0.126), 95.5% vs. 92.6% (p = 0.515), and 79.5% vs. 67.1% (p = 0.721), respectively. Among those patients who received ADT, the 10-year bPFS, CSS, and OS rates for the WP vs. the MP arms were 93.6% vs. 90.1% (p = 0.413), 94.2% vs. 96.0% (p = 0.927), and 73.7% vs. 70.2% (p = 0.030), respectively. Among those patients who did not receive ADT, the 10-year bPFS, CSS, and OS rates for the WP vs. the MP arms were 82.4% vs. 75.0% (p = 0.639), 100% vs. 88% (p = 0.198), and 87.5% vs. 58.8% (p = 0.030), respectively. Based on multivariate analysis, none of the evaluated parameters predicted for CSS, while bPFS was best predicted by ADT and percent positive biopsy results. OS was best predicted by age and percent positive biopsy results. Conclusions: For high-risk prostate cancer patients receiving brachytherapy, there is a nonsignificant trend toward improved bPFS, CSS, and OS rates when brachytherapy is given with WPRT. This trend is most apparent among ADT-naive patients, for whom a significant improvement in OS was observed.« less

The sensitivity of the electron transport within bulk zinc-blende gallium nitride to variations in the crystal temperature, the doping concentration, and the non-parabolicity coefficient associated with the lowest energy conduction band valley

DOE Office of Scientific and Technical Information (OSTI.GOV)

Siddiqua, Poppy; O'Leary, Stephen K., E-mail: stephen.oleary@ubc.ca

2016-09-07

Within the framework of a semi-classical three-valley Monte Carlo simulation approach, we analyze the steady-state and transient electron transport that occurs within bulk zinc-blende gallium nitride. In particular, we examine how the steady-state and transient electron transport that occurs within this material changes in response to variations in the crystal temperature, the doping concentration, and the non-parabolicity coefficient associated with the lowest energy conduction band valley. These results are then contrasted with those corresponding to a number of other compound semiconductors of interest.

Brief Report: Relationship Between ADOS-2, Module 4 Calibrated Severity Scores (CSS) and Social and Non-Social Standardized Assessment Measures in Adult Males with Autism Spectrum Disorder (ASD).

PubMed

Morrier, Michael J; Ousley, Opal Y; Caceres-Gamundi, Gabriella A; Segall, Matthew J; Cubells, Joseph F; Young, Larry J; Andari, Elissar

2017-12-01

The ADOS-2 Modules 1-3 now include a standardized calibrated severity score (CSS) from 1 to 10 based on the overall total raw score. Subsequent research published CSS for Module 4 (Hus, Lord, Journal of Autism and Developmental Disorders 44(8):1996-2012, 2014); however more research is needed to examine the psychometric properties of this CSS. Forty males with ASD completed an assessment battery consisting of ADOS-2 Module 4 and other clinical measures assessing core ASD symptomology and comorbidity. Pearson correlation analyses found that CSS did not correlate with measures that assessed core social deficits of ASD or general psychiatric co-morbidity, but CSS did correlate negatively with intellectual quotient. These findings provide information on the limitations and relevance of CSS to be taken into account in future clinical evaluations of ASD.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simon, S.L.

Root uptake of /sup 226/Ra, /sup 210/Pb and /sup 210/Po by mature sagebrush was studied using a soil injection method for spiking the soil with minimal root disturbance. The main objective was to measure vegetation concentrations and determine concentration ratios (CR's) due to root uptake as a function of time in mature big sagebrush. Concentration ratios obtained in mature vegetation and in steady-state situations may be valuable in assessing the impact of uranium mining and milling. The vegetation was sampled approximately every 3 months for a 2 year period. Significant levels of activity were detected in the vegetation beginning atmore » the first sampling (81 days after soil injection for /sup 226/Ra, 28 days for /sup 210/Pb and /sup 210/Po). There was an exponential decrease in concentration to an apparent steady-state value. Mean values (geometric) of the data pooled over the second year period indicated that the steady-state CR's for /sup 226/Ra, /sup 210/Pb and /sup 210/Po, as determined in mature sagebrush, were 0.04, 0.009, and 0.08, respectively. A three compartment mathematical model was formulated to help understand mechanisms of plant uptake and to predict, if possible, the concentration of /sup 226/Ra, /sup 210/Pb and /sup 210/Po in vegetation as a function of time after soil spiking. A numerical solution was determined by 'calibrating' the general model solution with constants determined from regressions of concentrations in vegetation, soil leaching and leaf leaching data. Validation of the model is currently not possible because of an absence of similar time-dependent uptake studies. 168 refs., 19 figs., 18 tabs.« less

Dynamic elementary mode modelling of non-steady state flux data.

PubMed

Folch-Fortuny, Abel; Teusink, Bas; Hoefsloot, Huub C J; Smilde, Age K; Ferrer, Alberto

2018-06-18

A novel framework is proposed to analyse metabolic fluxes in non-steady state conditions, based on the new concept of dynamic elementary mode (dynEM): an elementary mode activated partially depending on the time point of the experiment. Two methods are introduced here: dynamic elementary mode analysis (dynEMA) and dynamic elementary mode regression discriminant analysis (dynEMR-DA). The former is an extension of the recently proposed principal elementary mode analysis (PEMA) method from steady state to non-steady state scenarios. The latter is a discriminant model that permits to identify which dynEMs behave strongly different depending on the experimental conditions. Two case studies of Saccharomyces cerevisiae, with fluxes derived from simulated and real concentration data sets, are presented to highlight the benefits of this dynamic modelling. This methodology permits to analyse metabolic fluxes at early stages with the aim of i) creating reduced dynamic models of flux data, ii) combining many experiments in a single biologically meaningful model, and iii) identifying the metabolic pathways that drive the organism from one state to another when changing the environmental conditions.

Rate kernel theory for pseudo-first-order kinetics of diffusion-influenced reactions and application to fluorescence quenching kinetics.

PubMed

Yang, Mino

2007-06-07

Theoretical foundation of rate kernel equation approaches for diffusion-influenced chemical reactions is presented and applied to explain the kinetics of fluorescence quenching reactions. A many-body master equation is constructed by introducing stochastic terms, which characterize the rates of chemical reactions, into the many-body Smoluchowski equation. A Langevin-type of memory equation for the density fields of reactants evolving under the influence of time-independent perturbation is derived. This equation should be useful in predicting the time evolution of reactant concentrations approaching the steady state attained by the perturbation as well as the steady-state concentrations. The dynamics of fluctuation occurring in equilibrium state can be predicted by the memory equation by turning the perturbation off and consequently may be useful in obtaining the linear response to a time-dependent perturbation. It is found that unimolecular decay processes including the time-independent perturbation can be incorporated into bimolecular reaction kinetics as a Laplace transform variable. As a result, a theory for bimolecular reactions along with the unimolecular process turned off is sufficient to predict overall reaction kinetics including the effects of unimolecular reactions and perturbation. As the present formulation is applied to steady-state kinetics of fluorescence quenching reactions, the exact relation between fluorophore concentrations and the intensity of excitation light is derived.

Part-2: Analytical Expressions of Concentrations of Glucose, Oxygen, and Gluconic Acid in a Composite Membrane for Closed-Loop Insulin Delivery for the Non-steady State Conditions.

PubMed

Mehala, N; Rajendran, L; Meena, V

2017-02-01

A mathematical model developed by Abdekhodaie and Wu (J Membr Sci 335:21-31, 2009), which describes a dynamic process involving an enzymatic reaction and diffusion of reactants and product inside glucose-sensitive composite membrane has been discussed. This theoretical model depicts a system of non-linear non-steady state reaction diffusion equations. These equations have been solved using new approach of homotopy perturbation method and analytical solutions pertaining to the concentrations of glucose, oxygen, and gluconic acid are derived. These analytical results are compared with the numerical results, and limiting case results for steady state conditions and a good agreement is observed. The influence of various kinetic parameters involved in the model has been presented graphically. Theoretical evaluation of the kinetic parameters like the maximal reaction velocity (V max ) and Michaelis-Menten constants for glucose and oxygen (K g and K ox ) is also reported. This predicted model is very much useful for designing the glucose-responsive composite membranes for closed-loop insulin delivery.

Steady state preparative multiple dual mode counter-current chromatography: Productivity and selectivity. Theory and experimental verification.

PubMed

Kostanyan, Artak E; Erastov, Andrey A

2015-08-07

In the steady state (SS) multiple dual mode (MDM) counter-current chromatography (CCC), at the beginning of the first step of every cycle the sample dissolved in one of the phases is continuously fed into a CCC device over a constant time, not exceeding the run time of the first step. After a certain number of cycles, the steady state regime is achieved, where concentrations vary over time during each cycle, however, the concentration profiles of solutes eluted with both phases remain constant in all subsequent cycles. The objective of this work was to develop analytical expressions to describe the SS MDM CCC separation processes, which can be helpful to simulate and design these processes and select a suitable compromise between the productivity and the selectivity in the preparative and production CCC separations. Experiments carried out using model mixtures of compounds from the GUESSmix with solvent system hexane/ethyl acetate/methanol/water demonstrated a reasonable agreement between the predictions of the theory and the experimental results. Copyright © 2015 Elsevier B.V. All rights reserved.

Secreted phospholipase A2 of Clonorchis sinensis activates hepatic stellate cells through a pathway involving JNK signalling.

PubMed

Wu, Yinjuan; Li, Ye; Shang, Mei; Jian, Yu; Wang, Caiqin; Bardeesi, Adham Sameer A; Li, Zhaolei; Chen, Tingjin; Zhao, Lu; Zhou, Lina; He, Ai; Huang, Yan; Lv, Zhiyue; Yu, Xinbing; Li, Xuerong

2017-03-16

Secreted phospholipase A2 (sPLA2) is a protein secreted by Clonorchis sinensis and is a component of excretory and secretory products (CsESPs). Phospholipase A2 is well known for its role in liver fibrosis and inhibition of tumour cells. The JNK signalling pathway is involved in hepatic stellate cells (HSCs) activation. Blocking JNK activity with SP600125 inhibits HSCs activation. In a previous study, the protein CssPLA2 was expressed in insoluble inclusion bodies. Therefore, it's necessary to express CssPLA2 in water-soluble form and determine whether the enzymatic activity of CssPLA2 or cell signalling pathways is involved in liver fibrosis caused by clonorchiasis. Balb/C mice were given an abdominal injection of MBP-CssPLA2. Liver sections with HE and Masson staining were observed to detect accumulation of collagen. Western blot of mouse liver was done to detect the activation of JNK signalling pathway. In vitro, HSCs were incubated with MBP-CssPLA2 to detect the activation of HSCs as well as the activation of JNK signalling pathway. The mutant of MBP-CssPLA2 without enzymatic activity was constructed and was also incubated with HSCs to check whether activation of the HSCs was related to the enzymatic activity of MBP-CssPLA2. The recombinant protein MBP-CssPLA2 was expressed soluble and of good enzymatic activity. A mutant of CssPLA2, without enzymatic activity, was also constructed. In vivo liver sections of Balb/C mice that were given an abdominal injection of 50 μg/ml MBP-CssPLA2 showed an obvious accumulation of collagen and a clear band of P-JNK1 could be seen by western blot of the liver tissue. In vitro, MBP-CssPLA2, as well as the mutant, was incubated with HSCs and it was proved that activation of HSCs was related to activation of the JNK signalling pathway instead of the enzymatic activity of MBP-CssPLA2. Activation of HSCs by CssPLA2 is related to the activation of the JNK signalling pathway instead of the enzymatic activity of CssPLA2. This finding could provide a promising treatment strategy to interrupt the process of liver fibrosis caused by clonorchiasis.

Low T3 syndrome as a predictor of poor prognosis in chronic lymphocytic leukemia.

PubMed

Gao, Rui; Chen, Rui-Ze; Xia, Yi; Liang, Jin-Hua; Wang, Li; Zhu, Hua-Yuan; Zhu Wu, Jia-; Fan, Lei; Li, Jian-Yong; Yang, Tao; Xu, Wei

2018-02-19

Low triiodothyronine (T3) state is associated with poor prognosis in critical acute and prolonged illness. However, the information on thyroid dysfunction and cancer is limited. The aim of our study was to evaluate the prognostic value of low T3 syndrome in chronic lymphocytic leukemia (CLL). Two hundred and fifty-eight patients with detailed thyroid hormone profile at CLL diagnosis were enrolled. Low T3 syndrome was defined by low free T3 (FT3) level accompanied by normal-to-low free tetraiodothyronine (FT4) and thyroid-stimulating hormone (TSH) levels. A propensity score-matched method was performed to balance the baseline characteristics. Multivariate Cox regression analyses screened the independent prognostic factors related to time-to-first-treatment (TTFT) and cancer-specific survival (CSS). Area under the curve (AUC) assessed the predictive accuracy of CLL-International Prognostic Index (IPI) together with low T3 syndrome. The results showed that 37 (14.34%) patients had low T3 syndrome, which was significantly associated with unfavorable TTFT and CSS in the propensity-matched cohort, and it was an independent prognostic indicator for both TTFT and CSS. Serum FT3 level was positively related to protein metabolism and anemia, and inversely related to inflammatory state. Patients with only low FT3 demonstrated better survival than those with synchronously low FT3 and FT4, while those with synchronously low FT3, FT4 and TSH had the worst clinical outcome. Low T3 syndrome together with CLL-IPI had larger AUCs compared with CLL-IPI alone in TTFT and CSS prediction. In conclusion, low T3 syndrome may be a good candidate for predicting prognosis in future clinical practice of CLL. © 2018 UICC.

Steady-state voltammetry of hydroxide ion oxidation in aqueous solutions containing ammonia.

PubMed

Daniele, Salvatore; Baldo, M Antonietta; Bragato, Carlo; Abdelsalam, Mamdouh Elsayed; Denuault, Guy

2002-07-15

An oxidation process observed in dilute aqueous solutions of ammonia was investigated under steady-state conditions with gold microelectrodes with radii in the range 2.5-30 microm. Over the ammonia concentration range 0.1-10 mM, a well-defined voltammetric wave was observed at approximately 1.4 V versus Ag/AgCl. It was attributed to the oxidation of hydroxide ions that arise from the dissociation of the weak base. The steady-state limiting current was found to depend on the concentration of supporting electrolyte, and in solution with low electrolyte, it was enhanced by migration contribution, as expected for a negatively charged species that oxidizes on a positively charged electrode. In addition, the steady-state limiting current was proportional to both the ammonia concentration and the electrode radius. The overall electrode process was analyzed in terms of a CE mechanism (homogeneous chemical reaction preceding the heterogeneous electron transfer) with a fast chemical reaction when measurements were carried out in solutions containing NH3 at < or = 5 mM and with electrodes having a radius of > or = 5 microm. This was ascertained by comparing experimental and theoretical data obtained by simulation. The formation of the soluble complex species Au(NH3)2+ was also considered as a possible alternative to explain the presence of the oxidation wave. This process however was ruled out, as the experimental data did not fit theoretical predictions in any of the conditions employed in the investigation. Instead, the direct oxidation of NH3, probably to N2O, was invoked to explain the anomalous currents found when the CE process was strongly kinetically hindered. Throughout this study, a parallel was made between the CE mechanism investigated here and that known to occur during the hydrogen evolution reaction from weak acids.

Endogenous Thrombin Potential Changes during the First Cycle of Oral Contraceptive Use

PubMed Central

Westhoff, Carolyn L.; Pike, Malcolm C.; Cremers, Serge; Eisenberger, Andrew; Thomassen, Stella; Rosing, Jan

2017-01-01

Objectives Venous thromboembolism (VTE) risk increases within months of combination oral contraceptive (COC) initiation. Because elevated endogenous thrombin potential (ETP) has been found in several studies to be a VTE risk factor, we evaluated the extent of ETP changes during the initial cycle of an ethinyl estradiol (EE) and levonorgestrel (LNG) COC. We also assessed the relationship between ETP changes and systemic EE and LNG concentrations. Study Design Participants provided multiple blood samples during a first 21-day cycle of a 30 µg EE/150 µg LNG COC and after a further 7 days without an active COC. Thrombin generation measured with and without addition of activated protein C (APC) yielded ETP+APC and ETP−APC and the normalized APC sensitivity ratio (nAPCsr). EE and LNG pharmacokinetic analyses were conducted over 24 hours after the first COC tablet and again at steady state. Results Thrombin generation was determined in 16 of the 17 women who completed the study. Mean ETP−APC increased steadily to 21% above baseline at 24 hours after the 6th COC tablet (COC624; p < 0.001) and to 28% above baseline at steady state (COC21; p < 0.001). Mean ETP+APC increased considerably more – by 54% at COC624 and by 79% at steady state. Mean nAPCsr increased by 28% at COC624 and by 41% at steady state. Higher concentrations of EE or LNG were not correlated with greater increases in ETP. Conclusions ETP increases during the first COC cycle were substantial. Implications The early increases in ETP may provide biological support for the rapid increase in VTE risk during initial COC use. The lack of association between this clotting system perturbation and the systemic EE concentration is surprising and deserves further study. PMID:28088496

Toxicokinetic Triage for Environmental Chemicals | Science ...

EPA Pesticide Factsheets

Toxicokinetic (TK) models are essential for linking administered doses to blood and tissue concentrations. In vitro-to-in vivo extrapolation (IVIVE) methods have been developed to determine TK from limited in vitro measurements and chemical structure-based property predictions, providing a less resource–intensive alternative to traditional in vivo TK approaches. High throughput TK (HTTK) methods use IVIVE to estimate doses that produce steady-state plasma concentrations equivalent to those producing biological activity in in vitro screening studies (e.g., ToxCast). In this study, the domain of applicability and assumptions of HTTK approaches were evaluated using both in vivo data and simulation analysis. Based on in vivo data for 87 chemicals, specific properties (e.g., in vitro HTTK data, physico-chemical descriptors, chemical structure, and predicted transporter affinities) were identified that correlate with poor HTTK predictive ability. For 350 xenobiotics with literature HTTK data, we then differentiated those xenobiotics for which HTTK approaches are likely to be sufficient, from those that may require additional data. For 272 chemicals we also developed a HT physiologically-based TK (HTPBTK) model that requires somewhat greater information than a steady-state model, but allows non-steady state dynamics and can predict chemical concentration time-courses for a variety of exposure scenarios, tissues, and species. We used this HTPBTK model to show that the

Characterization of VOC Emission from Materials in Vehicular Environment at Varied Temperatures: Correlation Development and Validation

PubMed Central

Xiong, Jianyin; Yang, Tao; Tan, Jianwei; Li, Lan; Ge, Yunshan

2015-01-01

The steady state VOC concentration in automobile cabin is taken as a good indicator to characterize the material emission behaviors and evaluate the vehicular air quality. Most studies in this field focus on experimental investigation while theoretical analysis is lacking. In this paper we firstly develop a simplified physical model to describe the VOC emission from automobile materials, and then derive a theoretical correlation between the steady state cabin VOC concentration (C a) and temperature (T), which indicates that the logarithm of C a/T 0.75 is in a linear relationship with 1/T. Experiments of chemical emissions in three car cabins at different temperatures (24°C, 29°C, 35°C) were conducted. Eight VOCs specified in the Chinese National Standard GB/T 27630–2011 were taken for analysis. The good agreement between the correlation and experimental results from our tests, as well as the data taken from literature demonstrates the effectiveness of the derived correlation. Further study indicates that the slope and intercept of the correlation follows linear association. With the derived correlation, the steady state cabin VOC concentration different from the test conditions can be conveniently obtained. This study should be helpful for analyzing temperature-dependent emission phenomena in automobiles and predicting associated health risks. PMID:26452146

Domain-adaptive finite difference methods for collapsing annular liquid jets

NASA Astrophysics Data System (ADS)

Ramos, J. I.

1993-01-01

A domain-adaptive technique which maps a time-dependent, curvilinear geometry into a unit square is used to determine the steady state mass absorption rate and the collapse of annular liquid jets. A method of lines is used to solve the one-dimensional fluid dynamics equations written in weak conservation-law form, and upwind differences are employed to evaluate the axial convective fluxes. The unknown, time-dependent, axial location of the downstream boundary is determined from the solution of an ordinary differential equation which is nonlinearly coupled to the fluid dynamics and gas concentration equations. The equation for the gas concentration in the annular liquid jet is written in strong conservation-law form and solved by means of a method of lines at high Peclet numbers and a line Gauss-Seidel method at low Peclet numbers. The effects of the number of grid points along and across the annular jet, time step, and discretization of the radial convective fluxes on both the steady state mass absorption rate and the jet's collapse rate have been analyzed on staggered and non-staggered grids. The steady state mass absorption rate and the collapse of annular liquid jets are determined as a function of the Froude, Peclet and Weber numbers, annular jet's thickness-to-radius ratio at the nozzle exit, initial pressure difference across the annular jet, nozzle exit angle, temperature of the gas enclosed by the annular jet, pressure of the gas surrounding the jet, solubilities at the inner and outer interfaces of the annular jet, and gas concentration at the nozzle exit. It is shown that the steady state mass absorption rate is proportional to the inverse square root of the Peclet number except for low values of this parameter, and that the possible mathematical incompatibilities in the concentration field at the nozzle exit exert a great influence on the steady state mass absorption rate and on the jet collapse. It is also shown that the steady state mass absorption rate increases as the Weber number, nozzle exit angle, gas concentration at the nozzle exit, and temperature of the gases enclosed by the annular liquid jet are increased, but it decreases as the Froude and Peclet numbers, and annular liquid jet's thickness-to-radius ratio at the nozzle exit are increased. It is also shown that the annular liquid jet's collapse rate increases as the Weber number, nozzle exit angle, temperature of the gases enclosed by the annular liquid jet, and pressure of the gases which surround the jet are increased, but decreases as the Froude and Peclet numbers, and annular liquid jet's thickness-toradius ratio at the nozzle exit are increased. It is also shown that both the ratio of the initial pressure of the gas enclosed by the jet to the pressure of the gas surrounding the jet and the ratio of solubilities at the annular liquid jet's inner and outer interfaces play an important role on both the steady state mass absorption rate and the jet collapse. If the product of these ratios is greater or less than one, both the pressure and the mass of the gas enclosed by the annular liquid jet decrease or increase, respectively, with time. It is also shown that the numerical results obtained with the conservative, domain-adaptive method of lines technique presented in this paper are in excellent agreement with those of a domain-adaptive, iterative, non-conservative, block-bidiagonal, finite difference method which uncouples the solution of the fluid dynamics equations from that of the convergence length.

Acarbose bioequivalence: exploration of new pharmacodynamic parameters.

PubMed

Zhang, Min; Yang, Jin; Tao, Lei; Li, Lingjun; Ma, Pengcheng; Fawcett, John Paul

2012-06-01

To investigate bioequivalence (BE) testing of an acarbose formulation in healthy Chinese volunteers through the use of recommended and innovative pharmacodynamic (PD) parameters. Following the Food and Drug Administration (FDA) guidance, a randomized, cross-over study of acarbose test (T) and reference (R) (Glucobay®) formulations was performed with a 1-week wash-out period. Preliminary pilot studies showed that the appropriate dose of acarbose was 2 × 50 mg, and the required number of subjects was 40. Serum glucose concentrations after sucrose administration (baseline) and co-administration of sucrose/acarbose on the following day were both determined. Three newly defined PD measures of glucose fluctuation (glucose excursion (GE), GE' (glucose excursion without the effect of the homeostatic glucose control), and fAUC (degree of fluctuation of serum glucose based on AUC)), the plateau glucose concentration (C(ss)), and time of maximum reduction in glucose concentration (T (max)) were tested in the evaluation. The adequacy of the two parameters recommended by the FDA, ΔC(SG,max) (maximum reduction in serum glucose concentration) and AUEC((0-4h)) (reduction in the AUC((0-4h)) of glucose between baseline and acarbose formulation) was also evaluated. The T (max) values were comparable, and the 90% confidence intervals of the geometric test/reference ratios (T/R) for ΔC(SG,max), C(ss), GE, and fAUC were all within 80-125%. The parameter GE' was slightly outside the limits, and the parameter AUEC((0-4h)) could not be computed due to the presence of negative values. In acarbose BE evaluation, while the recommended parameter ΔC(SG,max) is valuable, the combination of C(ss) and one of the newly defined glucose fluctuation parameters, GE, GE', and fAUC is preferable than AUEC((0-4h)). The acarbose test formulation can be initially considered to be bioequivalent to Glucobay®.

Catechol-Functional Chitosan/Silver Nanoparticle Composite as a Highly Effective Antibacterial Agent with Species-Specific Mechanisms.

PubMed

Huang, Xiaofei; Bao, Xiaojiong; Liu, Yalan; Wang, Zhengke; Hu, Qiaoling

2017-05-12

In this study, silver nanoparticles (Ag NPs) coated with catechol-conjugated chitosan (CSS) were prepared using green methods. Interestingly, we uncovered that CSS-coated Ag NPs (CSS-Ag NPs) exhibited a higher toxicity against gram-negative Escherichia coli (E. coli) bacteria than against gram-positive Staphylococcus aureus (S. aureus) bacteria. The differences revealed that the CSS-Ag NPs killed gram bacteria with distinct, species-specific mechanisms. The aim of this study is to further investigate these underlying mechanisms through a series of analyses. The ultrastructure and morphology of the bacteria before and after treatment with CSS-Ag NPs were observed. The results demonstrated the CSS-Ag NPs killed gram-positive bacteria through a disorganization of the cell wall and leakage of cytoplasmic content. In contrast, the primary mechanism of action on gram-negative bacteria was a change in membrane permeability, induced by adsorption of CSS-Ag NPs. The species-specific mechanisms are caused by structural differences in the cell walls of gram bacteria. Gram-positive bacteria are protected from CSS-Ag NPs by a thicker cell wall, while gram-negatives are more easily killed due to an interaction between a special outer membrane and the nanoparticles. Our study offers an in-depth understanding of the antibacterial behaviors of CSS-Ag NPs and provides insights into ultimately optimizing the design of Ag NPs for treatment of bacterial infections.

A case report and literature review of Churg-Strauss syndrome presenting with myocarditis.

PubMed

Qiao, Lu; Gao, Dengfeng

2016-12-01

Churg-Strauss syndrome (CSS) is a multisystem disorder characterized by asthma, prominent peripheral blood eosinophilia, and vasculitis signs. Here we report a case of CSS presenting with acute myocarditis and heart failure and review the literature on CSS with cardiac involvement. A 59-year-old man with general fatigue, numbness of limbs, and a 2-year history of asthma was admitted to the department of orthopedics. Eosinophilia, history of asthma, lung infiltrates, peripheral neurological damage, and myocarditis suggested the diagnosis of CSS. Transthoracic echocardiography revealed a dilated hypokinetic left ventricle (left ventricular ejection fraction ∼40%) with mild segmental abnormalities in the septal and apical segments. By reviewing the present case reports, we concluded that (1) the younger age of CSS, the greater occurrence rate of complicating myocarditis and the poorer prognosis; (2) female CSS patients are older than male patients; (3) patients with cardiac involvement usually have a history of severe asthma; (4) markedly increased eosinophil count suggests a potential diagnosis of CSS (when the count increases to 20% of white blood cell counts or 8.1 × 109/L, eosinophils start to infiltrate into myocardium); and (5) negative ANCA status is associated with heart disease in CSS.

Socioeconomic factors and survival in patients with non-metastatic head and neck squamous cell carcinoma.

PubMed

Xu, Cheng; Chen, Yu-Pei; Liu, Xu; Tang, Ling-Long; Chen, Lei; Mao, Yan-Ping; Zhang, Yuan; Guo, Rui; Zhou, Guan-Qun; Li, Wen-Fei; Lin, Ai-Hua; Sun, Ying; Ma, Jun

2017-06-01

The effect of socioeconomic factors on receipt of definitive treatment and survival outcomes in non-metastatic head and neck squamous cell carcinoma (HNSCC) remains unclear. Eligible patients (n = 37 995) were identified from the United States Surveillance, Epidemiology and End Results (SEER) database between 2007 and 2012. Socioeconomic factors (i.e., median household income, education level, unemployment rate, insurance status, marital status and residence) were included in univariate/multivariate Cox regression analysis; validated factors were used to generate nomograms for cause-specific survival (CSS) and overall survival (OS), and a prognostic score model for risk stratification. Low- and high-risk groups were compared for all cancer subsites. Impact of race/ethnicity on survival was investigated in each risk group. Marital status, median household income and insurance status were included in the nomograms for CSS and OS, which had higher c-indexes than the 6th edition TNM staging system (all P < 0.001). Based on three disadvantageous socioeconomic factors (i.e., unmarried status, uninsured status, median household income

Insulin response of the glucose and fatty acid metabolism in dry dairy cows across a range of body condition scores.

PubMed

De Koster, J; Hostens, M; Van Eetvelde, M; Hermans, K; Moerman, S; Bogaert, H; Depreester, E; Van den Broeck, W; Opsomer, G

2015-07-01

The objective of the present research was to determine the insulin response of the glucose and fatty acid metabolism in dry dairy cows with a variable body condition score (BCS). Ten pregnant Holstein Friesian dairy cows (upcoming parity 2 to 5) were selected based on BCS at the beginning of the study (2mo before expected parturition date). During the study, animals were monitored weekly for BCS and backfat thickness and in the last 2wk, blood samples were taken for determination of serum nonesterified fatty acid (NEFA) concentration. Animals underwent a hyperinsulinemic euglycemic clamp test in the third week before the expected parturition date. The hyperinsulinemic euglycemic clamp test consisted of 4 consecutive insulin infusions with increasing insulin doses: 0.1, 0.5, 2, and 5mIU/kg per minute. For each insulin infusion period, a steady state was defined as a period of 30min where no or minor changes of the glucose infusion were necessary to keep the blood glucose concentration constant and near basal levels. During the steady state, the glucose infusion rate [steady state glucose infusion rate (SSGIR) in µmol/kg per minute] and NEFA concentration [steady state NEFA concentration (SSNEFA) in mmol/L] were determined and reflect the insulin response of the glucose and fatty acid metabolism. Dose response curves were created based on the insulin concentrations during the steady state and the SSGIR or SSNEFA. The shape of the dose response curves is determined by the concentration of insulin needed to elicit the half maximal effect (EC50) and the maximal SSGIR or the minimal SSNEFA for the glucose or fatty acid metabolism, respectively. The maximal SSGIR was negatively associated with variables reflecting adiposity of the cows (BCS, backfat thickness, NEFA concentration during the dry period, and absolute weight of the different adipose depots determined after euthanasia and dissection of the different depots), whereas the EC50 of the glucose metabolism was positively associated with these variables. These results reflect a decreased insulin sensitivity and a decreased insulin responsiveness of the glucose metabolism in overconditioned dry dairy cows. The minimal SSNEFA and the EC50 of the fatty acid metabolism were not associated with variables reflecting adiposity of the cows, meaning that the insulin response of the fatty acid metabolism was not associated with the level of fat accumulation in dry dairy cows. Additionally, within individual cows, the EC50 of the glucose metabolism was higher than the EC50 of the fatty acid metabolism, meaning that the response of the fatty acid metabolism occurs at lower insulin concentrations compared with the response of the glucose metabolism. It can be concluded that a negative association exists between the level of fat accumulation in pregnant dairy cows at the end of the dry period and the insulin response of the glucose metabolism. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Electrostatic Solitary Waves in the Solar Wind: Evidence for Instability at Solar Wind Current Sheets

NASA Technical Reports Server (NTRS)

Malaspina, David M.; Newman, David L.; Wilson, Lynn Bruce; Goetz, Keith; Kellogg, Paul J.; Kerstin, Kris

2013-01-01

A strong spatial association between bipolar electrostatic solitary waves (ESWs) and magnetic current sheets (CSs) in the solar wind is reported here for the first time. This association requires that the plasma instabilities (e.g., Buneman, electron two stream) which generate ESWs are preferentially localized to solar wind CSs. Distributions of CS properties (including shear angle, thickness, solar wind speed, and vector magnetic field change) are examined for differences between CSs associated with ESWs and randomly chosen CSs. Possible mechanisms for producing ESW-generating instabilities at solar wind CSs are considered, including magnetic reconnection.

Evaluation of a steady-state test of foam stability

NASA Astrophysics Data System (ADS)

Hutzler, Stefan; Lösch, Dörte; Carey, Enda; Weaire, Denis; Hloucha, Matthias; Stubenrauch, Cosima

2011-02-01

We have evaluated a steady-state test of foam stability, based on the steady-state height of a foam produced by a constant velocity of gas flow. This test is mentioned in the book by Bikerman [Foams, Springer, Berlin, 1973] and an elementary theory was developed for it by Verbist et al. [J. Phys. Condens. Matter 8 (1996) p. 3715]. For the study, we used an aqueous solution of the cationic surfactant dodecyl trimethylammonium bromide, C12TAB, at a concentration of two times the critical micelle concentration (2 cmc). During foam generation, bubbles collapse at the top of the column which, in turn, eventually counterbalances the rate of bubble production at the bottom. The resulting balance can be described mathematically by an appropriate solution of the foam drainage equation under specified boundary conditions. Our experimental findings are in agreement with the theoretical predictions of a diverging foam height at a critical gas velocity and a finite foam height in the limit of zero velocity. We identify a critical liquid fraction below which a foam is unstable as an important parameter for characterizing foam stability. Furthermore, we deduce an effective viscosity of the liquid which flows through the foam. Currently unexplained are two experimental observations, namely sudden changes of the steady-state foam height in experiments that run over several hours and a reduction in foam height once an overflow of the foam from the containing vessel has occurred.

Meat quality, oxidative stability and blood parameters from Graylag geese offered alternative fiber sources in growing period.

PubMed

He, L W; Meng, Q X; Li, D Y; Zhang, Y W; Ren, L P

2015-04-01

The effects of dietary fiber sources on the meat quality, oxidative stability, and blood parameters of growing Graylag geese (28-112d) were investigated. The birds were randomly allocated into 4 treatments, of which dietary fiber was mainly from corn straw silage (CSS), steam-exploded corn straw (SECS), steam-exploded wheat straw (SEWS), and steam-exploded rice straw (SERS). No influence (P>0.05) on the basic chemical components, oxidative stability, or organoleptic traits of muscle were observed, except that birds fed SECS had a higher (P<0.05) protein proportion than those fed CSS or SERS, and CSS increased (P<0.01) the cholesterol content when compared to SEWS or SERS. Regarding fatty acid profile in meat, CSS and SECS increased (P<0.01) the proportion of C18:2n6t and decreased that of C21:0 and C22:0 when compared to the others. The birds fed SERS had a higher (P<0.05) proportion of C20:0 and C22:0 than the others, a higher proportion of C20:5n3, n-3 fatty acids, Δ-9 desaturase (18) index compared to those fed CSS or SECS, and a lower (P<0.01) proportion of C20:1n9 than those fed SECS or SEWS. Additionally, SEWS resulted in a higher (P<0.01) proportion of C20:2 when compared to the others. In conclusion, these fibers affect just the protein proportion, cholesterol content, and fatty acid profile of breast muscle, along with the concentration of TG and MDA in blood, but not the other characteristics. No superior fiber source exists with respect to meat quality, suggesting that Graylag geese feeding should make the most economically of the convenient fiber source with appropriate pretreatment. © 2015 Poultry Science Association Inc.

A novel milliliter-scale chemostat system for parallel cultivation of microorganisms in stirred-tank bioreactors.

PubMed

Schmideder, Andreas; Severin, Timm Steffen; Cremer, Johannes Heinrich; Weuster-Botz, Dirk

2015-09-20

A pH-controlled parallel stirred-tank bioreactor system was modified for parallel continuous cultivation on a 10 mL-scale by connecting multichannel peristaltic pumps for feeding and medium removal with micro-pipes (250 μm inner diameter). Parallel chemostat processes with Escherichia coli as an example showed high reproducibility with regard to culture volume and flow rates as well as dry cell weight, dissolved oxygen concentration and pH control at steady states (n=8, coefficient of variation <5%). Reliable estimation of kinetic growth parameters of E. coli was easily achieved within one parallel experiment by preselecting ten different steady states. Scalability of milliliter-scale steady state results was demonstrated by chemostat studies with a stirred-tank bioreactor on a liter-scale. Thus, parallel and continuously operated stirred-tank bioreactors on a milliliter-scale facilitate timesaving and cost reducing steady state studies with microorganisms. The applied continuous bioreactor system overcomes the drawbacks of existing miniaturized bioreactors, like poor mass transfer and insufficient process control. Copyright © 2015 Elsevier B.V. All rights reserved.

Implications of Enhanced Relative Humidity in Cold Tropical Cirrus

NASA Technical Reports Server (NTRS)

Jensen, Eric; Pfister, Leonhard

2004-01-01

In situ measurements of water vapor concentration and temperature in tropical cirrus during the CRYSTAL-FACE and Pre-AVE missions indicate that the steady-state relative humidity within cirrus at T less than 200 K is about 20-30% higher than ice saturation. These measurements challenge the conventional belief, that any water vapor in excess of ice saturation should be depleted by crystal growth given sufficient time. Detailed simulations of thin cirrus near the tropopause indicate that this enhanced steady-state relative humidity increases ice number densities, decreases crystal sizes and extends cloud lifetimes. The areal coverage of thin cirrus in the tropics is increased rather than decreased as indicated by simpler conceptual models. Perhaps most significantly, the increased steady-state H2O saturation mixing ratio over ice in thin cirrus near the tropopause results in about a 0.5-1 ppmv increase in the amount of water that can enter the stratosphere across the tropical tropopause cold trap. Hence, the enhanced steady-state relative humidity in cold cirrus implies that lower tropopause temperatures are required to explain the observed stratospheric water vapor mixing ratios than previously assumed.

A kinetic approach to the study of absorption of solutes by isolated perfused small intestine

PubMed Central

Fisher, R. B.; Gardner, M. L. G.

1974-01-01

1. A new technique has been developed for making serial measurements of water and solute absorption from the lumen of isolated small intestine. 2. The isolated intestine is perfused in a single pass with a segmented flow of slugs of liquid separated by bubbles of oxygen-carbon dioxide mixture. Simultaneous collections are made of effluent from the lumen and of the fluid which is transported across the mucosa. This latter fluid appears to be a fair sample of the tissue fluid. 3. Conditions in the lumen can be changed within less than 5 min. The effects of two or more treatments applied to the same segment of intestine can be determined and the time course of a change in luminal conditions. 4. The rate of appearance of solutes on the serosal side depends on the rate of water absorption, and changes exponentially towards a steady state. The rate constant is a function of tissue fluid volume. 5. In the steady state the concentration of glucose in the tissue fluid is 71 mM when the luminal concentration is 28 mM, and is 45 mM when the luminal concentration is 8·3 mM. 6. For solutes such as glucose for which reflux from tissue fluid to lumen is small relative to flux from lumen to tissue fluid, the time of attainment of a steady state in secretion is usually 50-60 min. 7. For solutes such as sodium for which the reflux is relatively high, the steady state may be reached in 15-20 min. 8. The Km for glucose absorption (14-19 mM) is much lower than is found with unsegmented flow perfusion. 9. These findings emphasize problems in interpreting results from other types of intestinal preparation. 10. The rate of glucose absorption from the lumen falls only gradually when the luminal sodium concentration is reduced abruptly. In contrast the rate of glucose absorption falls suddenly when the luminal glucose concentration is reduced abruptly. This suggests that glucose absorption is not directly dependent on luminal sodium ions. ImagesPlate 1 PMID:4422346

Serum ferritin concentration in sickle cell crisis.

PubMed Central

Brownell, A; Lowson, S; Brozović, M

1986-01-01

Serum ferritin, aspartate aminotransferase (AST), alkaline phosphatase and hydroxybutyrate dehydrogenase (HBD) were studied during 21 vaso-occlusive crises in 12 adults with sickle cell disease (11 SS, 1 S beta degrees). The patients comprised three groups: those who had been untransfused (4), those who had received occasional exchange transfusion in crisis (3), and those who had been multiply transfused (5). Serum ferritin concentrations in crisis were compared with those of the steady state value. Rises in serum ferritin concentrations occurred in all crises in all groups. Although AST, alkaline phosphatase, and HBD rose, there was no correlation between these and log ferritin concentrations. The clinical impression was that the degree of rise in ferritin related to the severity of the particular crisis, and the above results showed that haemolysis and liver damage were not causally related to this rise. An estimate of serum ferritin cannot be used to assess the state of iron balance in sickle cell disease unless the patient is in the steady state. The considerable rise in serum ferritin concentration found in crisis, however, may be a useful marker of the extent of vaso-occlusion and tissue damage. PMID:3958215

Activation of Nrf2 by H2O2: de novo synthesis versus nuclear translocation.

PubMed

Covas, Gonçalo; Marinho, H Susana; Cyrne, Luísa; Antunes, Fernando

2013-01-01

The most common mechanism described for the activation of the transcription factor Nrf2 is based on the inhibition of its degradation in the cytosol followed by its translocation to the nucleus. Recently, Nrf2 de novo synthesis was proposed as an additional mechanism for the rapid upregulation of Nrf2 by hydrogen peroxide (H2O2). Here, we describe a detailed protocol, including solutions, pilot experiments, and experimental setups, which allows exploring the role of H2O2, delivered either as a bolus or as a steady state, in endogenous Nrf2 translocation and synthesis. We also show experimental data, illustrating that H2O2 effects on Nrf2 activation in HeLa cells are strongly dependent both on the H2O2 concentration and on the method of H2O2 delivery. The de novo synthesis of Nrf2 is triggered within 5min of exposure to low concentrations of H2O2, preceding Nrf2 translocation to the nucleus which is slower. Evidence of de novo synthesis of Nrf2 is observed only for low H2O2 steady-state concentrations, a condition that is prevalent in vivo. This study illustrates the applicability of the steady-state delivery of H2O2 to uncover subtle regulatory effects elicited by H2O2 in narrow concentration and time ranges. Copyright © 2013 Elsevier Inc. All rights reserved.

Mathematical modeling improves EC50 estimations from classical dose-response curves.

PubMed

Nyman, Elin; Lindgren, Isa; Lövfors, William; Lundengård, Karin; Cervin, Ida; Sjöström, Theresia Arbring; Altimiras, Jordi; Cedersund, Gunnar

2015-03-01

The β-adrenergic response is impaired in failing hearts. When studying β-adrenergic function in vitro, the half-maximal effective concentration (EC50 ) is an important measure of ligand response. We previously measured the in vitro contraction force response of chicken heart tissue to increasing concentrations of adrenaline, and observed a decreasing response at high concentrations. The classical interpretation of such data is to assume a maximal response before the decrease, and to fit a sigmoid curve to the remaining data to determine EC50 . Instead, we have applied a mathematical modeling approach to interpret the full dose-response curve in a new way. The developed model predicts a non-steady-state caused by a short resting time between increased concentrations of agonist, which affect the dose-response characterization. Therefore, an improved estimate of EC50 may be calculated using steady-state simulations of the model. The model-based estimation of EC50 is further refined using additional time-resolved data to decrease the uncertainty of the prediction. The resulting model-based EC50 (180-525 nm) is higher than the classically interpreted EC50 (46-191 nm). Mathematical modeling thus makes it possible to re-interpret previously obtained datasets, and to make accurate estimates of EC50 even when steady-state measurements are not experimentally feasible. The mathematical models described here have been submitted to the JWS Online Cellular Systems Modelling Database, and may be accessed at http://jjj.bio.vu.nl/database/nyman. © 2015 FEBS.

Evaluation of the closest speaking space in different dental and skeletal occlusions.

PubMed

Sakar, Olcay; Bural, Canan; Sülün, Tonguç; Öztaş, Evren; Marşan, Gülnaz

2013-04-01

The closest speaking space (CSS) together with the vertical overlap of anterior teeth during the production of the /s/ sound have not been previously investigated with respect to differences in dental and skeletal orthodontic classifications. The purpose of this study was to investigate the CSS in dental and skeletal occlusions and to analyze the cause and effect relationship of the CSS and the amount of the vertical overlap of anterior teeth. Poly vinylsiloxane interocclusal registration material was placed bilaterally onto the occlusal surfaces of premolar and molar teeth of 155 native Turkish speaking adolescent and young adult dentate participants, who were then asked to pronounce the word seyis. The thinnest point between the maxillary and mandibular teeth was recorded in millimeters as the CSS. The occlusion of each participant was classified according to the Angle dental and Steiner skeletal classifications. The differences in CSS values within each classification were statistically analyzed with the Kruskal-Wallis test, and the correlation between the CSS and the vertical overlap was statistically analyzed with the Spearman Rho Correlation tests (P<.05). The differences in the CSS were only significant between Angle Class II division 2 and Class III groups (P=.034), while the differences in the CSS between skeletal classes were not significant. The correlation between the amount of CSS and the amount of vertical overlap was not significant. The results showed that regardless of dental and skeletal occlusions, average CSS values could be used to determine the occlusal vertical dimension of prosthetic restorations. Copyright © 2013 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

Does gestational age affect the pharmacokinetics and pharmacodynamics of lidocaine in mother and fetus?

PubMed

Pedersen, H; Santos, A C; Morishima, H O; Finster, M; Plosker, H; Arthur, G R; Covino, B G

1988-03-01

The pharmacokinetics and pharmacodynamics of lidocaine were studied in nine chronically prepared pregnant ewes and their fetuses at a mean ( +/- SE) gestation of 119 +/- 1.0 days, and the results were compared to the data previously published for ten animals at 138 +/- 1.2 days of gestation (term 148 days). Lidocaine was infused intravenously to the mother at a constant rate of 0.1 mg.kg-1.min-1 over a period of 180 min, in order to reach a steady-state maternal plasma lidocaine concentration of approximately 2 micrograms/ml. Maternal and fetal blood samples and maternal urine were collected at intervals throughout the infusion for determination of pH, blood gases, and lidocaine concentrations. Maternal and fetal heart rate, blood pressure, and intraamniotic pressure were continuously recorded. Fetal cardiac output and organ blood flow were determined before and at the end of lidocaine infusion using radionuclide-labeled microspheres. Lidocaine tissue concentrations were determined in several maternal and fetal organs excised at the end of infusion. In both groups, the steady-state plasma concentrations of lidocaine were similar; namely, 2.3 +/- 0.17 and 2.1 +/- 0.21 micrograms/ml in preterm and term ewes, respectively. There were also no significant differences in steady-state plasma drug concentrations in preterm and term fetuses (1.3 +/- 0.11 and 1.2 +/- 0.15 micrograms/ml). The mean fetal maternal concentration ratios (F/M) were the same; namely, 0.6. Maternal urinary excretion of lidocaine correlated with urine pH, being greater in the more acid urine. Tissue uptake of drug tended to be higher in the preterm than term mothers, but only significantly so in the brain and adrenals.(ABSTRACT TRUNCATED AT 250 WORDS)

Debiased estimates for NEO orbits, absolute magnitudes, and source regions

NASA Astrophysics Data System (ADS)

Granvik, Mikael; Morbidelli, Alessandro; Jedicke, Robert; Bolin, Bryce T.; Bottke, William; Beshore, Edward C.; Vokrouhlicky, David; Nesvorny, David; Michel, Patrick

2017-10-01

The debiased absolute-magnitude and orbit distributions as well as source regions for near-Earth objects (NEOs) provide a fundamental frame of reference for studies on individual NEOs as well as on more complex population-level questions. We present a new four-dimensional model of the NEO population that describes debiased steady-state distributions of semimajor axis (a), eccentricity (e), inclination (i), and absolute magnitude (H). We calibrate the model using NEO detections by the 703 and G96 stations of the Catalina Sky Survey (CSS) during 2005-2012 corresponding to objects with 17

[Update Churg-Strauss syndrome].

PubMed

Moosig, F; Hellmich, B

2012-11-01

The Churg-Strauss syndrome (CSS) is the rarest subtype of the so-called anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) and has the lowest frequency of ANCA-positivity (around 30%). In addition to asthma and blood eosinophilia, CSS is characterized by end-organ damage, which can be caused by either vasculitis and/or tissue infiltration of eosinophilic granulocytes. The CSS shares many etiological and clinical features of other hypereosinophilic syndromes. Recently, a distinct genetic background could be demonstrated for both the ANCA-positive and ANCA-negative subtypes of CSS as compared to the other two forms of AAV. Among other cytokines, interleukin-5 (IL-5) could be identified as a key mediator of eosinophilia. Therefore, recent clinical trials in CSS aimed to target IL-5. Outside of clinical trials, treatment of CSS is adapted to disease stage and activity, as recommended for other types of AAV.

Chondroitin sulfate synthase-2 is necessary for chain extension of chondroitin sulfate but not critical for skeletal development.

PubMed

Ogawa, Hiroyasu; Hatano, Sonoko; Sugiura, Nobuo; Nagai, Naoko; Sato, Takashi; Shimizu, Katsuji; Kimata, Koji; Narimatsu, Hisashi; Watanabe, Hideto

2012-01-01

Chondroitin sulfate (CS) is a linear polysaccharide consisting of repeating disaccharide units of N-acetyl-D-galactosamine and D-glucuronic acid residues, modified with sulfated residues at various positions. Based on its structural diversity in chain length and sulfation patterns, CS provides specific biological functions in cell adhesion, morphogenesis, neural network formation, and cell division. To date, six glycosyltransferases are known to be involved in the biosynthesis of chondroitin saccharide chains, and a hetero-oligomer complex of chondroitin sulfate synthase-1 (CSS1)/chondroitin synthase-1 and chondroitin sulfate synthase-2 (CSS2)/chondroitin polymerizing factor is known to have the strongest polymerizing activity. Here, we generated and analyzed CSS2(-/-) mice. Although they were viable and fertile, exhibiting no overt morphological abnormalities or osteoarthritis, their cartilage contained CS chains with a shorter length and at a similar number to wild type. Further analysis using CSS2(-/-) chondrocyte culture systems, together with siRNA of CSS1, revealed the presence of two CS chain species in length, suggesting two steps of CS chain polymerization; i.e., elongation from the linkage region up to Mr ∼10,000, and further extension. There, CSS2 mainly participated in the extension, whereas CSS1 participated in both the extension and the initiation. Our study demonstrates the distinct function of CSS1 and CSS2, providing a clue in the elucidation of the mechanism of CS biosynthesis.

Correlating the chemical and spectroscopic characteristics of natural organic matter with the photodegradation of sulfamerazine.

PubMed

Batista, Ana Paula S; Teixeira, Antonio Carlos S C; Cooper, William J; Cottrell, Barbara A

2016-04-15

The role of aquatic natural organic matter (NOM) in the removal of contaminants of emerging concern has been widely studied. Sulfamerazine (SMR), a sulfonamide antibiotic detected in aquatic environments, is implicated in environmental toxicity and may contribute to the resistance of bacteria to antibiotics. In aquatic systems sulfonamides may undergo direct photodegradation, and, indirect photodegradation through the generation of reactive species. Because some forms of NOM inhibit the photodegradation there is an increasing interest in correlating the spectroscopic parameters of NOM as potential indicators of its degradation in natural waters. Under the conditions used in this study, SMR hydrolysis was shown to be negligible; however, direct photolysis is a significant in most of the solutions studied. Photodegradation was investigated using standard solutions of NOM: Suwannee River natural organic matter (SRNOM), Suwannee River humic acid (SRHA), Suwannee River fulvic acid (SRFA), and Aldrich humic acid (AHA). The steady-state concentrations and formation rates of the reactive species and the SMR degradation rate constants (k1) were correlated with NOM spectroscopic parameters determined using UV-vis absorption, excitation-emission matrix (EEM) fluorescence spectroscopy, and proton nuclear magnetic resonance ((1)H NMR). SMR degradation rate constants (k1) were correlated with steady-state concentrations of NOM triplet-excited state ([(3)NOM(∗)]ss) and the corresponding formation rates ((3)NOM*) for SRNOM, SRHA, and AHA. The efficiency of SMR degradation was highest in AHA solution and was inhibited in solutions of SRFA. The steady-state concentrations of singlet oxygen ([(1)O2]ss) and the SMR degradation rate constants with singlet oxygen (k1O2) were linearly correlated with the total fluorescence and inversely correlated with the carbohydrate/protein content ((1)H NMR) for all forms of NOM. The total fluorescence and EEMs Peak A were confirmed as indicators of (1)O2 formation. Specific ultraviolet absorbance at 254 nm (SUVA254) and aromaticity showed potential correlations with the steady-state concentrations of hydroxyl radical ([HO]ss) and the corresponding formation rates (HO). Copyright © 2015 Elsevier Ltd. All rights reserved.

Crossflow microfiltration of yeast suspensions in tubular filters.

PubMed

Redkar, S G; Davis, R H

1993-01-01

Crossflow microfiltration experiments were performed on yeast suspensions through 0.2-microns pore size ceramic and polypropylene tubes at various operating conditions. The initial transient flux decline follows dead-end filtration theory, with the membrane resistance determined from the initial flux and the specific cake resistance determined from the rate of flux decline due to cake buildup. For long times, the observed fluxes reach steady or nearly steady values, presumably as a result of the cake growth being arrested by the shear exerted at its surface. The steady-state fluxes increase with increasing shear rate and decreasing feed concentration, and they are nearly independent of transmembrane pressure. The steady-state fluxes for unwashed yeast in deionized water or fermentation media are typically 2-4 times lower than those predicted by a model based on the properties of nonadhesive, rigid spheres undergoing shear-induced back-diffusion. In contrast, the steady-state fluxes observed for washed yeast cells in deionized water are only 10-30% below the predicted values. The washed yeast cells also exhibited specific cake resistances that are an order of magnitude lower than those for the unwashed yeast. The differences are due to the presence of extracellular proteins and other macromolecules in the unwashed yeast suspensions. These biopolymers cause higher cell adhesion and resistance in the cake layer, so that the cells at the top edge are not free to diffuse away. This is manifested as a concentration jump from the edge of the cake layer to the sheared suspension adjacent to it.(ABSTRACT TRUNCATED AT 250 WORDS)

Fatty acids rather than hormones restore in vitro angiogenesis in human male and female endothelial cells cultured in charcoal-stripped serum

PubMed Central

Vanetti, Claudia; Bifari, Francesco; Vicentini, Lucia M.

2017-01-01

Charcoal-stripped serum (CSS) is a well-accepted method to model effects of sex hormones in cell cultures. We have recently shown that human endothelial cells (ECs) fail to growth and to undergo in vitro angiogenesis when cultured in CSS. However, the mechanism(s) underlying the CSS-induced impairment of in vitro EC properties are still unknown. In addition, whether there is any sexual dimorphism in the CSS-induced EC phenotype remains to be determined. Here, by independently studying human male and female ECs, we found that CSS inhibited both male and female EC growth and in vitro angiogenesis, with a more pronounced effect on male EC sprouting. Reconstitution of CSS with 17-β estradiol, dihydrotestosterone, or the lipophilic thyroid hormone did not restore EC functions in both sexes. On the contrary, supplementation with palmitic acid or the acetyl-CoA precursor acetate significantly rescued the CSS-induced inhibition of growth and sprouting in both male and female ECs. We can conclude that the loss of metabolic precursors (e.g., fatty acids) rather than of hormones is involved in the impairment of in vitro proliferative and angiogenic properties of male and female ECs cultured with CSS. PMID:29232396

Confounding of the association between radiation exposure from CT scans and risk of leukemia and brain tumors by cancer susceptibility syndromes.

PubMed

Meulepas, Johanna M; Ronckers, Cécile M; Merks, Johannes; Weijerman, Michel E; Lubin, Jay H; Hauptmann, Michael

2016-12-01

Recent studies linking radiation exposure from pediatric computed tomography (CT) to increased risks of leukemia and brain tumors lacked data to control for cancer susceptibility syndromes (CSS). These syndromes might be confounders because they are associated with an increased cancer risk and may increase the likelihood of pediatric CT scans. We identify CSS predisposing to leukemia and brain tumors through a systematic literature search and summarize prevalence and risk. Since empirical evidence is lacking in published literature on patterns of CT use for most types of CSS, we estimate confounding bias of relative risks (RR) for categories of radiation exposure based on expert opinion about patterns of CT scans among CSS patients. We estimate that radiation-related RRs for leukemia are not meaningfully confounded by Down syndrome, Noonan syndrome and other CSS. Moreover, tuberous sclerosis complex, von Hippel-Lindau disease, neurofibromatosis type 1 and other CSS do not meaningfully confound RRs for brain tumors. Empirical data on the use of CT scans among CSS patients is urgently needed. Our assessment indicates that associations with radiation exposure from pediatric CT scans and leukemia or brain tumors reported in previous studies are unlikely to be substantially confounded by unmeasured CSS.

A case report and literature review of Churg–Strauss syndrome presenting with myocarditis

PubMed Central

Qiao, Lu; Gao, Dengfeng

2016-01-01

Abstract Background: Churg–Strauss syndrome (CSS) is a multisystem disorder characterized by asthma, prominent peripheral blood eosinophilia, and vasculitis signs. Case summary: Here we report a case of CSS presenting with acute myocarditis and heart failure and review the literature on CSS with cardiac involvement. A 59-year-old man with general fatigue, numbness of limbs, and a 2-year history of asthma was admitted to the department of orthopedics. Eosinophilia, history of asthma, lung infiltrates, peripheral neurological damage, and myocarditis suggested the diagnosis of CSS. Transthoracic echocardiography revealed a dilated hypokinetic left ventricle (left ventricular ejection fraction ∼40%) with mild segmental abnormalities in the septal and apical segments. Conclusion: By reviewing the present case reports, we concluded that (1) the younger age of CSS, the greater occurrence rate of complicating myocarditis and the poorer prognosis; (2) female CSS patients are older than male patients; (3) patients with cardiac involvement usually have a history of severe asthma; (4) markedly increased eosinophil count suggests a potential diagnosis of CSS (when the count increases to 20% of white blood cell counts or 8.1 × 109/L, eosinophils start to infiltrate into myocardium); and (5) negative ANCA status is associated with heart disease in CSS. PMID:28002315

Modeling Single and Repeated Dose Pharmacokinetics of PFOA in Mice (J)

EPA Science Inventory

Perfluorooctanoic acid (PFOA) displays complicated pharmacokinetics in that serum concentrations indicate long half-lives despite which steady state appears to be achieved rapidly. In this study, serum and tissue concentration time-courses were obtained for male and female CD1 m...

Differences in Steady-State Net Ammonium and Nitrate Influx by Cold- and Warm-Adapted Barley Varieties 1

PubMed Central

Bloom, Arnold J.; Chapin, F. Stuart

1981-01-01

A flowing nutrient culture system permitted relatively rapid determination of the steady-state net nitrogen influx by an intact barley (Hardeum vulgare L. cv Kombar and Olli) plant. Ion-selective electrodes monitored the depletion of ammonium and nitrate from a nutrient solution after a single pass through a root cuvette. Influx at concentrations as low as 4 micromolar was measured. Standard errors for a sample size of three plants were typically less than 10% of the mean. When grown under identical conditions, a variety of barley bred for cold soils had higher nitrogen influx rates at low concentrations and low temperatures than one bred for warm soils, whereas the one bred for warm soils had higher influx rates at high concentrations and high temperatures. Ammonium was more readily absorbed than nitrate by both varieties at all concentrations and temperatures tested. Ammonium and nitrate influx in both varieties were equally inhibited by low temperatures. PMID:16662052

Centaur Standard Shroud (CSS) Heated Altitude Jettison Tests

NASA Technical Reports Server (NTRS)

1975-01-01

Altitude jettison tests, at a pressure of 20 torr (0.39 psia), were performed on the Centaur Standard Shroud (CSS) in a 100-foot diameter vacuum chamber. These jettison tests were part of a series of flight qualification tests which were performed on the new CSS system in preparation for the Helios and Viking missions. The first two tests subjected the CSS to a thermal cycle which simulated aerodynamic heating during ascent flight and the third test was performed at altitude pressure and in ambient temperature conditions. The purpose of the ambient temperature test was to provide base line data by which the separate machanical and thermal factors that influence jettison performance could be evaluated individually. The CSS was successfully jettisoned in each of the three tests. Also, thermal, stress, and structural deflection data were obtained which verified the analytical predictions of CSS response to flight environmental conditions and performance during jettison. In addition, much important information was obtained on critical CSS-to-payload clearance losses due to shell motions prior to and during jettison. The effectiveness of the separation system was successfully demonstrated at maximum flight temperatures.

A pseudoleukemic blood differentiation in a 13-year-old child: an extraordinary presentation of Churg-Strauss syndrome.

PubMed

Mutsaers, E R; Witteveen, R; van den Bosch-Ruis, W; Kuijpers, T W; van Houten, M A; van den Berg, J M

2013-03-01

Churg-Strauss syndrome (CSS) is a rare systemic vasculitis of the small- and medium-size vessels. It is mostly seen in elderly patients presenting as de novo asthma, eosinophilia, and vasculitic organ involvement. In childhood, CSS is extremely rare. The course of pediatric CSS is usually severe and often lethal. We present a case of a 13-year-old girl with a short history of asthma, marked eosinophilia, and multiorgan involvement. The extremely high level of blood eosinophilic granulocytes (51.6 × 10(9)/L) prompted a workup for eosinophilic leukemia before the diagnosis CSS could be made. Subsequently, the disease was successfully treated. This case report shows a classical case of childhood CSS, remarkable because of the presence of extreme hypereosinophilia. It underlines the importance of CSS as a life-threatening cause of hypereosinophilia in children.

Measurement of cerebral oxidative glucose consumption in patients with type 1 diabetes and hypoglycemia unawareness using 13C nuclear magnetic resonance spectroscopy

PubMed Central

Henry, Pierre-Gilles; Criego, Amy B.; Kumar, Anjali; Seaquist, Elizabeth R.

2009-01-01

The aim of the present study was to use 13C NMR to measure the cerebral oxidative metabolic rate of glucose (CMRglc(ox)) in patients with diabetes and to compare these measurements with those collected from matched controls. We elected to study a group with type 1 diabetes and hypoglycemia unawareness, since we had previously found such patients to have higher brain glucose concentrations than normal volunteers under steady state conditions. We sought to determine if this difference in steady-state brain concentrations could be explained by a difference in CMRglc(ox). Time courses of 13C label incorporation in brain amino acids were measured in occipital cortex during infusion of [1-13C]glucose. These time courses were fitted using a one-compartment metabolic model to determine CMRglc(ox). Our results show that the TCA cycle rate (VTCA, which is twice CMRglc(ox)) in subjects with type 1 diabetes was not significantly different from normal controls (0.84 ± 0.03 vs 0.79 ± 0.03 μmol/gm/min, n=5 in each group, mean ± SEM). We conclude that the changes in steady-state brain glucose concentrations that we observed in patients with type 1 diabetes in a previous study (1) cannot be explained by changes in oxidative glucose consumption PMID:19766263

Short communication: Production response of lactating dairy cows to brachytic forage sorghum silage compared with corn silage from first or second harvest.

PubMed

Bernard, J K; Tao, S

2015-12-01

A completely randomized lactation trial was conducted to compare the production response of lactating Holstein cows to diets based on corn or forage sorghum silage harvested from 2 crops. Corn was planted in March and harvested in July (corn silage-summer; CSS) and a second corn crop was planted in July and harvested in November (corn silage-fall; CSF). A brachytic dwarf brown midrib forage sorghum was planted in April, harvested in July (forage sorghum-summer; FSS), fertilized, and harvested a second time in November (forage sorghum-fall; FSF). All forage was ensiled in plastic bags and stored until the production trial began. Silages contained (dry matter basis) 8.0, 8.5, 9.0, and 9.5% crude protein; 39.0, 38.3, 54.2, and 55.1% neutral detergent fiber; and 3.6, 2.8. 7.7, and 7.8% acid detergent lignin, for CSS, CSF, FSS, and FSF, respectively. Forty-eight mid-lactation Holstein cows (153.5±37.2d in milk, 35.7±6.2kg/d of milk, 3.2±0.6% fat, 611.8±67.0kg of body weight, and 2.96±0.09 body condition score) were assigned randomly to 1 of the 4diets differing in forage source. Cows were individually fed experimental diets once daily behind Calan doors for 5wk. Diets were formulated to contain 38.7% of the experimental forages and balanced to provide equal concentrations of protein, fiber, and energy. No differences were observed in dry matter intake and yields of milk and components, but milk fat percentage was lower for CSS and CSF compared with FSS and FSF, being 3.20, 2.91, 3.42, and 3.53%, respectively. Milk lactose percentage was lower for CSS compared with CSF but was not different from FSS or FSF. Concentrations of milk urea nitrogen were lower for CSS and CSF compared with FSS and FSF (10.6, 13.4, 14.9, and 15.3mg/dL, respectively). No differences were observed in body weight or body condition score change during the trial. Results of this trial suggest that silage produced from brachytic forage sorghum, as either the first or the ratoon crop, can support similar intake and performance as diets based on corn silage. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Catalytic conversion reactions mediated by single-file diffusion in linear nanopores: hydrodynamic versus stochastic behavior.

PubMed

Ackerman, David M; Wang, Jing; Wendel, Joseph H; Liu, Da-Jiang; Pruski, Marek; Evans, James W

2011-03-21

We analyze the spatiotemporal behavior of species concentrations in a diffusion-mediated conversion reaction which occurs at catalytic sites within linear pores of nanometer diameter. Diffusion within the pores is subject to a strict single-file (no passing) constraint. Both transient and steady-state behavior is precisely characterized by kinetic Monte Carlo simulations of a spatially discrete lattice-gas model for this reaction-diffusion process considering various distributions of catalytic sites. Exact hierarchical master equations can also be developed for this model. Their analysis, after application of mean-field type truncation approximations, produces discrete reaction-diffusion type equations (mf-RDE). For slowly varying concentrations, we further develop coarse-grained continuum hydrodynamic reaction-diffusion equations (h-RDE) incorporating a precise treatment of single-file diffusion in this multispecies system. The h-RDE successfully describe nontrivial aspects of transient behavior, in contrast to the mf-RDE, and also correctly capture unreactive steady-state behavior in the pore interior. However, steady-state reactivity, which is localized near the pore ends when those regions are catalytic, is controlled by fluctuations not incorporated into the hydrodynamic treatment. The mf-RDE partly capture these fluctuation effects, but cannot describe scaling behavior of the reactivity.

Propensity approach to nonequilibrium thermodynamics of a chemical reaction network: Controlling single E-coli β-galactosidase enzyme catalysis through the elementary reaction stepsa)

NASA Astrophysics Data System (ADS)

Das, Biswajit; Banerjee, Kinshuk; Gangopadhyay, Gautam

2013-12-01

In this work, we develop an approach to nonequilibrium thermodynamics of an open chemical reaction network in terms of the elementary reaction propensities. The method is akin to the microscopic formulation of the dissipation function in terms of the Kullback-Leibler distance of phase space trajectories in Hamiltonian system. The formalism is applied to a single oligomeric enzyme kinetics at chemiostatic condition that leads the reaction system to a nonequilibrium steady state, characterized by a positive total entropy production rate. Analytical expressions are derived, relating the individual reaction contributions towards the total entropy production rate with experimentally measurable reaction velocity. Taking a real case of Escherichia coli β-galactosidase enzyme obeying Michaelis-Menten kinetics, we thoroughly analyze the temporal as well as the steady state behavior of various thermodynamic quantities for each elementary reaction. This gives a useful insight in the relative magnitudes of various energy terms and the dissipated heat to sustain a steady state of the reaction system operating far-from-equilibrium. It is also observed that, the reaction is entropy-driven at low substrate concentration and becomes energy-driven as the substrate concentration rises.

Modeling steady-state methanogenic degradation of phenols in groundwater

USGS Publications Warehouse

Bekins, Barbara A.; Godsy, E. Michael; Goerlitz, Donald F.

1993-01-01

Field and microcosm observations of methanogenic phenolic compound degradation indicate that Monod kinetics governs the substrate disappearance but overestimates the observed biomass. In this paper we present modeling results from an ongoing multidisciplinary study of methanogenic biodegradation of phenolic compounds in a sand and gravel aquifer contaminated by chemicals and wastes used in wood treatment. Field disappearance rates of four phenols match those determined in batch microcosm studies previously performed by E.M. Godsy and coworkers. The degradation process appears to be at steady-state because even after a sustained influx over several decades, the contaminants still are disappearing in transport downgradient. The existence of a steady-state degradation profile of each substrate together with a low biomass density in the aquifer indicate that the bacteria population is exhibiting no net growth. This may be due to the oligotrophic nature of the biomass population in which utilization and growth are approximately independent of concentration for most of the concentration range. Thus a constant growth rate should exist over much of the contaminated area which may in turn be balanced by an unusually high decay or maintenance rate due to hostile conditions or predation.

Light controls phospholipase A2α and β gene expression in Citrus sinensis

PubMed Central

Liao, Hui-Ling; Burns, Jacqueline K.

2010-01-01

The low-molecular weight secretory phospholipase A2α (CssPLA2α) and β (CsPLA2β) cloned in this study exhibited diurnal rhythmicity in leaf tissue of Citrus sinensis. Only CssPLA2α displayed distinct diurnal patterns in fruit tissues. CssPLA2α and CsPLA2β diurnal expression exhibited periods of approximately 24 h; CssPLA2α amplitude averaged 990-fold in the leaf blades from field-grown trees, whereas CsPLA2β amplitude averaged 6.4-fold. Diurnal oscillation of CssPLA2α and CsPLA2β gene expression in the growth chamber experiments was markedly dampened 24 h after transfer to continuous light or dark conditions. CssPLA2α and CsPLA2β expressions were redundantly mediated by blue, green, red and red/far-red light, but blue light was a major factor affecting CssPLA2α and CsPLA2β expression. Total and low molecular weight CsPLA2 enzyme activity closely followed diurnal changes in CssPLA2α transcript expression in leaf blades of seedlings treated with low intensity blue light (24 μmol m−2 s−1). Compared with CssPLA2α basal expression, CsPLA2β expression was at least 10-fold higher. Diurnal fluctuation and light regulation of PLA2 gene expression and enzyme activity in citrus leaf and fruit tissues suggests that accompanying diurnal changes in lipophilic second messengers participate in the regulation of physiological processes associated with phospholipase A2 action. PMID:20388744

Mathematical modeling of filling of gas centrifuge cascade for nickel isotope separation by various feed flow rate

NASA Astrophysics Data System (ADS)

Ushakov, Anton; Orlov, Alexey; Sovach, Victor P.

2018-03-01

This article presents the results of research filling of gas centrifuge cascade for separation of the multicomponent isotope mixture with process gas by various feed flow rate. It has been used mathematical model of the nonstationary hydraulic and separation processes occurring in the gas centrifuge cascade. The research object is definition of the regularity transient of nickel isotopes into cascade during filling of the cascade. It is shown that isotope concentrations into cascade stages after its filling depend on variable parameters and are not equal to its concentration on initial isotope mixture (or feed flow of cascade). This assumption is used earlier any researchers for modeling such nonstationary process as set of steady-state concentration of isotopes into cascade. Article shows physical laws of isotope distribution into cascade stage after its filling. It's shown that varying each parameters of cascade (feed flow rate, feed stage number or cascade stage number) it is possible to change isotope concentration on output cascade flows (light or heavy fraction) for reduction of duration of further process to set of steady-state concentration of isotopes into cascade.

Design and performance characterization strategy using modeling for biofiltration control of odorous hydrogen sulfide.

PubMed

Martin, Ronald W; Mihelcic, James R; Crittenden, John C

2004-07-01

Biofilter, dynamic modeling software characterizing contaminant removal via biofiltration, was used in the preliminary design of a biofilter to treat odorous hydrogen sulfide (H2S). Steady-state model simulations were run to generate performance plots for various influent concentrations, loadings, residence times, media sizes, and temperatures. Although elimination capacity and removal efficiency frequently are used to characterize biofilter performance, effluent concentration can be used to characterize performance when treating to a target effluent concentration. Model simulations illustrate that, at a given temperature, a biofilter cannot reduce H2S emissions below a minimum value, no matter how large the biofilter or how long the residence time. However, a higher biofilter temperature results in lower effluent H2S concentrations. Because dynamic model simulations show that shock loading can significantly increase the effluent concentration above values predicted by the steady-state model simulations, it is recommended that, to consistently meet treatment objectives, dynamic feed conditions should be considered. This study illustrates that modeling can serve as a valuable tool in the design and performance optimization of biofilters.

Acute coronary syndrome caused by coronary vasospasms associated with Churg-Strauss syndrome: effects of betamethasone therapy.

PubMed

Suzuki, Yuji; Nishiyama, Osamu; Sakai, Toshiaki; Niiyama, Masanobu; Itoh, Tomonori; Nakamura, Motoyuki

2014-01-01

A 42-year-old woman with a history of aspirin-induced asthma was admitted with severe chest pain. Emergency coronary angiography revealed coronary artery spasms. The administration of vasodilators did not suppress the anginal symptoms, and the differential white blood cell count continued to show eosinophilia. The patient's symptoms of aspirin-induced asthma, eosinophilia and other allergic states led to the diagnosis of Churg-Strauss syndrome (CSS). After starting betamethasone therapy, the eosinophilia and cardiac symptoms rapidly disappeared. Although coronary vasospasms related to CSS are rare, the present case suggests that a differential white blood cell count should be obtained in patients with refractory coronary vasospasms.

Steady-State Electrodiffusion from the Nernst-Planck Equation Coupled to Local Equilibrium Monte Carlo Simulations.

PubMed

Boda, Dezső; Gillespie, Dirk

2012-03-13

We propose a procedure to compute the steady-state transport of charged particles based on the Nernst-Planck (NP) equation of electrodiffusion. To close the NP equation and to establish a relation between the concentration and electrochemical potential profiles, we introduce the Local Equilibrium Monte Carlo (LEMC) method. In this method, Grand Canonical Monte Carlo simulations are performed using the electrochemical potential specified for the distinct volume elements. An iteration procedure that self-consistently solves the NP and flux continuity equations with LEMC is shown to converge quickly. This NP+LEMC technique can be used in systems with diffusion of charged or uncharged particles in complex three-dimensional geometries, including systems with low concentrations and small applied voltages that are difficult for other particle simulation techniques.

Newborn Parent Based Intervention to Increase Child Safety Seat Use.

PubMed

Liu, Xiangxiang; Yang, Jingzhen; Cheng, Fuyuan; Li, Liping

2016-08-02

This paper intends to assess the effect of a maternity department intervention on improvement of knowledge and use of child safety seats (CSS) among newborn parents. An intervention study included three groups (one education plus free CSS intervention group, one education only group, and one control group). The participants were parents of newborns in the maternity department of two hospitals. Both of the intervention groups received a folded pamphlet of child passenger safety, a height chart and standardized safety education during their hospital stay after giving birth. The education plus free CSS intervention group received an additional free CSS and professional installation training at hospital discharge. The control group received a pamphlet with educational information about nutrition and food safety. Three months after enrollment, a telephone follow-up was conducted among participants in the three groups. Data on child passenger safety knowledge, risky driving behaviors, and use of CSS were evaluated before and after the intervention. A total of 132 newborn parents were enrolled in the study; of those, 52 (39.4%) were assigned into the education plus free CSS intervention group, 44 (33.3%) were in the education intervention only group, and 36 (27.3%) were in the control group. No significant differences existed in demographics among the three groups. There was a significant difference in newborn parents' child passenger safety knowledge and behaviors in the three groups before and after the intervention. In addition, the CSS use increased significantly in the education plus free CSS group after the intervention compared to parents in the education only or control groups. Education on safety, combined with a free CSS and professional installation training, were effective at increasing newborn parents' knowledge and use of CSS. Future studies with larger sample sizes and longer follow-up are needed to determine a long-term effect of the intervention.

Metabolism of Secoisolariciresinol-Diglycoside The Dietary Precursor to The Intestinally Derived Lignan Enterolactone in Humans

PubMed Central

Setchell, Kenneth D. R.; Brown, Nadine M.; Zimmer-Nechemias, Linda; Wolfe, Brian; Jha, Pinky; Heubi, James E.

2014-01-01

Secoisolariciresinol-diglycoside (SDG), a natural dietary lignan of flaxseeds now available in dietary supplements, is converted by intestinal bacteria to the mammalian lignans enterodiol and enterolactone. High levels of these lignans in blood and urine are associated with reduced risk of many chronic diseases. Our objective was to determine the bioavailability and pharmacokinetics of SDG in purified flaxseed extracts under dose-ranging and steady-state conditions, and to examine whether differences in secoisolariciresinol-diglycoside purity influence bioavailability. Pharmacokinetic studies were performed on healthy postmenopausal women after oral intake of 25, 50, 75, 86 and 172mg of secoisolariciresinol-diglycoside. Extracts differing in secoisolariciresinol-diglycoside purity were compared, and steady-state lignan concentrations measured after daily intake for one week. Blood and urine samples were collected at timed intervals and secoisolariciresinol, enterodiol and enterolactone concentrations measured by mass spectrometry. Secoisolariciresinol-diglycoside was efficiently hydrolyzed and converted to secoisolariciresinol. Serum concentrations increased rapidly after oral intake, peaking after 5-7h and disappearing with a plasma elimination half-life of 4.8h. Maximum serum concentrations of the biologically active metabolites, enterodiol and enterolactone were established after 12-24h and 24-36h, respectively, and the half-lives were 9.4h and 13.2h. Linear dose-responses were observed and secoisolariciresinol bioavailability correlated (r2=0.835) with cumulative lignan excretion. There were no significant differences in the pharmacokinetics of extracts differing in purity, and steady-state serum lignan concentrations were obtained after one-week of daily dosing. In conclusion, this study defines the pharmacokinetics of secoisolariciresinol-diglycoside and shows it is first hydrolyzed and then metabolized in a time-dependent sequence to secoisolariciresinol, enterodiol and ultimately enterolactone, and these metabolites are efficiently absorbed. PMID:24429845

On the kinetics of anaerobic power

PubMed Central

2012-01-01

Background This study investigated two different mathematical models for the kinetics of anaerobic power. Model 1 assumes that the work power is linear with the work rate, while Model 2 assumes a linear relationship between the alactic anaerobic power and the rate of change of the aerobic power. In order to test these models, a cross country skier ran with poles on a treadmill at different exercise intensities. The aerobic power, based on the measured oxygen uptake, was used as input to the models, whereas the simulated blood lactate concentration was compared with experimental results. Thereafter, the metabolic rate from phosphocreatine break down was calculated theoretically. Finally, the models were used to compare phosphocreatine break down during continuous and interval exercises. Results Good similarity was found between experimental and simulated blood lactate concentration during steady state exercise intensities. The measured blood lactate concentrations were lower than simulated for intensities above the lactate threshold, but higher than simulated during recovery after high intensity exercise when the simulated lactate concentration was averaged over the whole lactate space. This fit was improved when the simulated lactate concentration was separated into two compartments; muscles + internal organs and blood. Model 2 gave a better behavior of alactic energy than Model 1 when compared against invasive measurements presented in the literature. During continuous exercise, Model 2 showed that the alactic energy storage decreased with time, whereas Model 1 showed a minimum value when steady state aerobic conditions were achieved. During interval exercise the two models showed similar patterns of alactic energy. Conclusions The current study provides useful insight on the kinetics of anaerobic power. Overall, our data indicate that blood lactate levels can be accurately modeled during steady state, and suggests a linear relationship between the alactic anaerobic power and the rate of change of the aerobic power. PMID:22830586

Metabolism of secoisolariciresinol-diglycoside the dietary precursor to the intestinally derived lignan enterolactone in humans.

PubMed

Setchell, Kenneth D R; Brown, Nadine M; Zimmer-Nechemias, Linda; Wolfe, Brian; Jha, Pinky; Heubi, James E

2014-03-01

Secoisolariciresinol-diglycoside (SDG), a natural dietary lignan of flaxseeds now available in dietary supplements, is converted by intestinal bacteria to the mammalian lignans enterodiol and enterolactone. High levels of these lignans in blood and urine are associated with reduced risk of many chronic diseases. Our objective was to determine the bioavailability and pharmacokinetics of SDG in purified flaxseed extracts under dose-ranging and steady-state conditions, and to examine whether differences in secoisolariciresinol-diglycoside purity influence bioavailability. Pharmacokinetic studies were performed on healthy postmenopausal women after oral intake of 25, 50, 75, 86 and 172 mg of secoisolariciresinol-diglycoside. Extracts differing in secoisolariciresinol-diglycoside purity were compared, and steady-state lignan concentrations measured after daily intake for one week. Blood and urine samples were collected at timed intervals and secoisolariciresinol, enterodiol and enterolactone concentrations measured by mass spectrometry. Secoisolariciresinol-diglycoside was efficiently hydrolyzed and converted to secoisolariciresinol. Serum concentrations increased rapidly after oral intake, peaking after 5-7 h and disappearing with a plasma elimination half-life of 4.8 h. Maximum serum concentrations of the biologically active metabolites, enterodiol and enterolactone were attained after 12-24 h and 24-36 h, respectively, and the half-lives were 9.4 h and 13.2 h. Linear dose-responses were observed and secoisolariciresinol bioavailability correlated (r(2) = 0.835) with cumulative lignan excretion. There were no significant differences in the pharmacokinetics of extracts differing in purity, and steady-state serum lignan concentrations were obtained after one-week of daily dosing. In conclusion, this study defines the pharmacokinetics of secoisolariciresinol-diglycoside and shows it is first hydrolyzed and then metabolized in a time-dependent sequence to secoisolariciresinol, enterodiol and ultimately enterolactone, and these metabolites are efficiently absorbed.

EVALUATING TOOLS AND MODELS USED FOR QUANTITATIVE EXTRAPOLATION OF IN VITRO TO IN VIVO DATA FOR NEUROTOXICANTS

EPA Science Inventory

Comparisons of high throughput screening data to human exposures assume that media concentrations are equivalent to steady-state blood concentrations. This assumes the partitioning of the chemical between media and cells is equivalent to the partitioning of the chemical between b...

A Survey of Attitudes and Practices Regarding the Use of Steroid Supplementation in Pediatric Sepsis.

PubMed

Carmean, Amanda; Fortenberry, James D; McCracken, Courtney; Hebbar, Kiran B

2015-10-01

Although corticosteroid (CS) supplementation for pediatric septic shock (PSS) is recommended by American College of Critical Care Medicine sepsis guidelines, most data are based on adult trials. Standardized protocols for stimulation testing for adrenal insufficiency (AI) and CS treatment in children have been reported, but the current state of CS use and protocols have not been evaluated in pediatric intensive care units in the United States. We surveyed a group of pediatric intensivists to assess current approaches. An electronic survey with 54 questions on attitudes and current use of CSs was distributed to 49 pediatric critical care and 49 pediatric endocrinology fellowship program directors. Twenty-one (43%) of 49 critical care recipients completed the survey. Eleven (52%) were from medical/surgical units and 10 (48%) were from medical/surgical/cardiac units, with a median of 24 beds and 1614 annual admissions. Thirteen (62%) of 21 recipients rated the importance of steroids in the management of PSS as greater than 4 or 5, with 1 being of no importance and 5 of critical importance. Nineteen (90%) of 21 recipients thought AI occurs "sometimes" or "often" in septic shock. Adrenocorticotropin stimulation testing was frequently used (19 of 21; 90%) but not in protocol. Eighteen (85%) of 21 recipients agreed that "some should" receive "steroids as it improves outcome" and 9% agreed that "most should…" Fourteen (66%) of 21 recipients reported that more than 50% of patients with vasopressor-refractory PSS receive CSs. Hydrocortisone was used in 21 (100%) of 21 recipients, but dosing and duration were variable. Concerns to limit/avoid CSs included hyperglycemia (38%), superinfections (81%), and critical illness myopathy (57%). Only 3 (14%) of 21 recipients reported that they used a CS protocol for PSS. Sixteen (76%) of 21 recipients were not comfortable drawing conclusions from adult studies for PSS. Nineteen (90%) of 21 recipients agreed that it would be important to perform a randomized trial for CS use in PSS. Corticosteroids are used at most centers for treatment of PSS, but significant variation in attitudes and use exists. Most centers identify AI as frequent; most report variable use of stimulation testing and dosing of CSs. Few centers currently use a standard protocol for diagnosis and treatment. Interest in performing a randomized trial for CSs remains because in part of reluctance to accept adult trial data.

AKM in Open Source Communities

NASA Astrophysics Data System (ADS)

Stamelos, Ioannis; Kakarontzas, George

Previous chapters in this book have dealt with Architecture Knowledge Management in traditional Closed Source Software (CSS) projects. This chapterwill attempt to examine the ways that knowledge is shared among participants in Free Libre Open Source Software (FLOSS 1) projects and how architectural knowledge is managed w.r.t. CSS. FLOSS projects are organized and developed in a fundamentally different way than CSS projects. FLOSS projects simply do not develop code as CSS projects do. As a consequence, their knowledge management mechanisms are also based on different concepts and tools.

A case report for fatal Churg-Strauss syndrome complications: first reported death due to rapid progression of prominently huge hepatic capsular hematoma and multi-system organ hemorrhage

PubMed Central

Qian, Jiejing; Tong, Hongyan; Chen, Feifei; Mai, Wenyuan; Lou, Yinjun; Jin, Jie

2014-01-01

Churg-Strauss syndrome (CSS) is a rare disease that has an extremely low incidence rate. CSS prognosis is good, in general; and there are no reports of multiple-organ hemorrhage in CSS. We report a unique case of CSS, wherein, an elderly man experienced multiple organ hemorrhage -- a particularly huge hematoma under the capsule of the liver and poor prognosis. PMID:25419420

Pharmacokinetic Study of Intravenous Acetaminophen Administered to Critically Ill Multiple-Trauma Patients at the Usual Dosage and a New Proposal for Administration.

PubMed

Fuster-Lluch, Oscar; Zapater-Hernández, Pedro; Gerónimo-Pardo, Manuel

2017-10-01

The pharmacokinetic profile of intravenous acetaminophen administered to critically ill multiple-trauma patients was studied after 4 consecutive doses of 1 g every 6 hours. Eleven blood samples were taken (predose and 15, 30, 45, 60, 90, 120, 180, 240, 300, and 360 minutes postdose), and urine was collected (during 6-hour intervals between doses) to determine serum and urine acetaminophen concentrations. These were used to calculate the following pharmacokinetic parameters: maximum and minimum concentrations, terminal half-life, area under serum concentration-time curve from 0 to 6 hours, mean residence time, volume of distribution, and serum and renal clearance of acetaminophen. Daily doses of acetaminophen required to obtain steady-state minimum (bolus dosing) and average plasma concentrations (continuous infusion) of 10 μg/mL were calculated (10 μg/mL is the presumed lower limit of the analgesic range). Data are expressed as median [interquartile range]. Twenty-two patients were studied, mostly young (age 44 [34-64] years) males (68%), not obese (weight 78 [70-84] kg). Acetaminophen concentrations and pharmacokinetic parameters were these: maximum concentration 33.6 [25.7-38.7] μg/mL and minimum concentration 0.5 [0.2-2.3] μg/mL, all values below 10 μg/mL and 8 below the detection limit; half-life 1.2 [1.0-1.9] hours; area under the curve for 6 hours 34.7 [29.7-52.7] μg·h/mL; mean residence time 1.8 [1.3-2.6] hours; steady-state volume of distribution 50.8 [42.5-66.5] L; and serum and renal clearance 28.8 [18.9-33.7] L/h and 15 [11-19] mL/min, respectively. Theoretically, daily doses for a steady-state minimum concentration of 10 μg/mL would be 12.2 [7.8-16.4] g/day (166 [112-202] mg/[kg·day]); for an average steady-state concentration of 10 μg/mL, they would be 6.9 [4.5-8.1] g/day (91 [59-111] mg/[kg·day]). In conclusion, administration of acetaminophen at the recommended dosage of 1 g per 6 hours to critically ill multiple-trauma patients yields serum concentrations below 10 μg/mL due to increased elimination. To reach the 10 μg/mL target, and from a strictly pharmacokinetic point of view, continuous infusion may be more feasible than bolus dosing. Such a change in dosing strategy requires appropriate, pharmacokinetic-pharmacodynamic and specific safety study. © 2017, The American College of Clinical Pharmacology.

Predicting residential exposure to phthalate plasticizer emitted from vinyl flooring: a mechanistic analysis.

PubMed

Xu, Ying; Hubal, Elaine A Cohen; Clausen, Per A; Little, John C

2009-04-01

A two-room model is developed to estimate the emission rate of di-2-ethylhexyl phthalate (DEHP) from vinyl flooring and the evolving gas-phase and adsorbed surface concentrations in a realistic indoor environment. Because the DEHP emission rate measured in a test chamber may be quite different from the emission rate from the same material in the indoor environment the model provides a convenient means to predict emissions and transport in a more realistic setting. Adsorption isotherms for phthalates and plasticizers on interior surfaces, such as carpet, wood, dust, and human skin, are derived from previous field and laboratory studies. Log-linear relationships between equilibrium parameters and chemical vapor pressure are obtained. The predicted indoor air DEHP concentration at steady state is 0.15 microg/m3. Room 1 reaches steady state within about one year, while the adjacent room reaches steady state about three months later. Ventilation rate has a strong influence on DEHP emission rate while total suspended particle concentration has a substantial impact on gas-phase concentration. Exposure to DEHP via inhalation, dermal absorption, and oral ingestion of dust is evaluated. The model clarifies the mechanisms that govern the release of DEHP from vinyl flooring and the subsequent interactions with interior surfaces, airborne particles, dust, and human skin. Although further model development, parameter identification, and model validation are needed, our preliminary model provides a mechanistic framework that elucidates exposure pathways for phthalate plasticizers, and can most likely be adapted to predict emissions and transport of other semivolatile organic compounds, such as brominated flame retardants and biocides, in a residential environment.

Cortical superficial siderosis and first-ever cerebral hemorrhage in cerebral amyloid angiopathy

PubMed Central

Boulouis, Gregoire; Xiong, Li; Jessel, Michel J.; Roongpiboonsopit, Duangnapa; Ayres, Alison; Schwab, Kristin M.; Rosand, Jonathan; Gurol, M. Edip; Greenberg, Steven M.; Viswanathan, Anand

2017-01-01

Objective: To investigate whether cortical superficial siderosis (cSS) is associated with increased risk of future first-ever symptomatic lobar intracerebral hemorrhage (ICH) in patients with cerebral amyloid angiopathy (CAA) presenting with neurologic symptoms and without ICH. Methods: Consecutive patients meeting modified Boston criteria for probable CAA in the absence of ICH from a single-center cohort were analyzed. cSS and other small vessel disease MRI markers were assessed according to recent consensus recommendations. Patients were followed prospectively for future incident symptomatic lobar ICH. Prespecified Cox proportional hazard models were used to investigate cSS and first-ever lobar ICH risk adjusting for potential confounders. Results: The cohort included 236 patients with probable CAA without lobar ICH at baseline. cSS prevalence was 34%. During a median follow-up of 3.26 years (interquartile range 1.42–5.50 years), 27 of 236 patients (11.4%) experienced a first-ever symptomatic lobar ICH. cSS was a predictor of time until first ICH (p = 0.0007, log-rank test). The risk of symptomatic ICH at 5 years of follow-up was 19% (95% confidence interval [CI] 11%–32%) for patients with cSS at baseline vs 6% (95% CI 3%–12%) for patients without cSS. In multivariable Cox regression models, cSS presence was the only independent predictor of increased symptomatic ICH risk during follow-up (HR 4.04; 95% CI 1.73–9.44, p = 0.001), after adjusting for age, lobar cerebral microbleeds burden, and white matter hyperintensities. Conclusions: cSS is consistently associated with an increased risk of future lobar ICH in CAA with potentially important clinical implications for patient care decisions such as antithrombotic use. PMID:28356458

Cultured Skin Substitutes Reduce Donor Skin Harvesting for Closure of Excised, Full-Thickness Burns

PubMed Central

Boyce, Steven T.; Kagan, Richard J.; Yakuboff, Kevin P.; Meyer, Nicholas A.; Rieman, Mary T.; Greenhalgh, David G.; Warden, Glenn D.

2002-01-01

Objective Comparison of cultured skin substitutes (CSS) and split-thickness skin autograft (AG) was performed to assess whether donor-site harvesting can be reduced quantitatively and whether functional and cosmetic outcome is similar qualitatively in the treatment of patients with massive cutaneous burns. Summary Background Data Cultured skin substitutes consisting of collagen-glycosaminoglycan substrates populated with autologous fibroblasts and keratinocytes have been shown to close full-thickness skin wounds in preclinical and clinical studies with acceptable functional and cosmetic results. Methods Qualitative outcome was compared between CSS and AG in 45 patients on an ordinal scale (0, worst; 10, best) with primary analyses at postoperative day 28 and after about 1 year for erythema, pigmentation, pliability, raised scar, epithelial blistering, and surface texture. In the latest 12 of the 45 patients, tracings were performed of donor skin biopsies and wounds treated with CSS at postoperative days 14 and 28 to calculate percentage engraftment, the ratio of closed wound:donor skin areas, and the percentage of total body surface area closed with CSS. Results Measures of qualitative outcome of CSS or AG were not different statistically at 1 year after grafting. Engraftment at postoperative day 14 exceeded 75% in the 12 patients evaluated. The ratio of closed wound:donor skin areas for CSS at postoperative day 28 was significantly greater than for conventional 4:1 meshed autografts. The percentage of total body surface area closed with CSS at postoperative day 28 was significantly less than with AG. Conclusions The requirement for harvesting of donor skin for CSS was less than for conventional skin autografts. These results suggest that acute-phase recovery of patients with extensive burns is facilitated and that complications are reduced by the use of CSS together with conventional skin grafting. PMID:11807368

Cultured skin substitutes reduce donor skin harvesting for closure of excised, full-thickness burns.

PubMed

Boyce, Steven T; Kagan, Richard J; Yakuboff, Kevin P; Meyer, Nicholas A; Rieman, Mary T; Greenhalgh, David G; Warden, Glenn D

2002-02-01

Comparison of cultured skin substitutes (CSS) and split-thickness skin autograft (AG) was performed to assess whether donor-site harvesting can be reduced quantitatively and whether functional and cosmetic outcome is similar qualitatively in the treatment of patients with massive cutaneous burns. Cultured skin substitutes consisting of collagen-glycosaminoglycan substrates populated with autologous fibroblasts and keratinocytes have been shown to close full-thickness skin wounds in preclinical and clinical studies with acceptable functional and cosmetic results. Qualitative outcome was compared between CSS and AG in 45 patients on an ordinal scale (0, worst; 10, best) with primary analyses at postoperative day 28 and after about 1 year for erythema, pigmentation, pliability, raised scar, epithelial blistering, and surface texture. In the latest 12 of the 45 patients, tracings were performed of donor skin biopsies and wounds treated with CSS at postoperative days 14 and 28 to calculate percentage engraftment, the ratio of closed wound:donor skin areas, and the percentage of total body surface area closed with CSS. Measures of qualitative outcome of CSS or AG were not different statistically at 1 year after grafting. Engraftment at postoperative day 14 exceeded 75% in the 12 patients evaluated. The ratio of closed wound:donor skin areas for CSS at postoperative day 28 was significantly greater than for conventional 4:1 meshed autografts. The percentage of total body surface area closed with CSS at postoperative day 28 was significantly less than with AG. The requirement for harvesting of donor skin for CSS was less than for conventional skin autografts. These results suggest that acute-phase recovery of patients with extensive burns is facilitated and that complications are reduced by the use of CSS together with conventional skin grafting.

On the Kaolinite Floc Size at the Steady State of Flocculation in a Turbulent Flow

PubMed Central

Zhu, Zhongfan; Wang, Hongrui; Yu, Jingshan; Dou, Jie

2016-01-01

The flocculation of cohesive fine-grained sediment plays an important role in the transport characteristics of pollutants and nutrients absorbed on the surface of sediment in estuarine and coastal waters through the complex processes of sediment transport, deposition, resuspension and consolidation. Many laboratory experiments have been carried out to investigate the influence of different flow shear conditions on the floc size at the steady state of flocculation in the shear flow. Most of these experiments reported that the floc size decreases with increasing shear stresses and used a power law to express this dependence. In this study, we performed a Couette-flow experiment to measure the size of the kaolinite floc through sampling observation and an image analysis system at the steady state of flocculation under six flow shear conditions. The results show that the negative correlation of the floc size on the flow shear occurs only at high shear conditions, whereas at low shear conditions, the floc size increases with increasing turbulent shear stresses regardless of electrolyte conditions. Increasing electrolyte conditions and the initial particle concentration could lead to a larger steady-state floc size. PMID:26901652

On the Kaolinite Floc Size at the Steady State of Flocculation in a Turbulent Flow.

PubMed

Zhu, Zhongfan; Wang, Hongrui; Yu, Jingshan; Dou, Jie

2016-01-01

The flocculation of cohesive fine-grained sediment plays an important role in the transport characteristics of pollutants and nutrients absorbed on the surface of sediment in estuarine and coastal waters through the complex processes of sediment transport, deposition, resuspension and consolidation. Many laboratory experiments have been carried out to investigate the influence of different flow shear conditions on the floc size at the steady state of flocculation in the shear flow. Most of these experiments reported that the floc size decreases with increasing shear stresses and used a power law to express this dependence. In this study, we performed a Couette-flow experiment to measure the size of the kaolinite floc through sampling observation and an image analysis system at the steady state of flocculation under six flow shear conditions. The results show that the negative correlation of the floc size on the flow shear occurs only at high shear conditions, whereas at low shear conditions, the floc size increases with increasing turbulent shear stresses regardless of electrolyte conditions. Increasing electrolyte conditions and the initial particle concentration could lead to a larger steady-state floc size.

Steady-state plasma and bronchopulmonary concentrations of intravenous levofloxacin and azithromycin in healthy adults.

PubMed

Rodvold, Keith A; Danziger, Larry H; Gotfried, Mark H

2003-08-01

The purpose of this study was to compare the concentrations of levofloxacin and azithromycin in steady-state plasma, epithelial lining fluid (ELF), and alveolar macrophage (AM) after intravenous administration. Thirty-six healthy, nonsmoking adult subjects were randomized to either intravenous levofloxacin (500 or 750 mg) or azithromycin (500 mg) once daily for five doses. Venipuncture and bronchoscopy with bronchoalveolar lavage were performed in each subject at either 4, 12, or 24 h after the start of the last antibiotic infusion. The mean concentrations of levofloxacin and azithromycin in plasma were similar to those previously published. The dosing regimens of levofloxacin achieved significantly (P < 0.05) higher concentrations in steady-state plasma than azithromycin during the 24 h after drug administration. The respective mean (+/- standard deviation) concentrations at 4, 12, and 24 h in ELF for 500 mg of levofloxacin were 11.01 +/- 4.52, 2.50 +/- 0.97, and 1.24 +/- 0.55 micro g/ml; those for 750 mg of levofloxacin were 12.94 +/- 1.21, 6.04 +/- 0.39, and 1.73 +/- 0.78 micro g/ml; and those for azithromycin were 1.70 +/- 0.74, 1.27 +/- 0.47, and 2.86 +/- 1.75 micro g/ml. The differences in concentrations in ELF among the two levofloxacin groups and azithromycin were significantly (P < 0.05) higher at the 4- and 12-h sampling times. The respective concentrations in AM for 500 mg of levofloxacin were 83.9 +/- 53.2, 18.3 +/- 6.7, and 5.6 +/- 3.2 micro g/ml; those for 750 mg of levofloxacin were 81.7 +/- 37.0, 78.2 +/- 55.4, and 13.3 +/- 6.5 micro g/ml; and those for azithromycin were 650 +/- 259, 669 +/- 311, and 734 +/- 770 micro g/ml. Azithromycin achieved significantly (P < 0.05) higher concentrations in AM than levofloxacin at all sampling times. The concentrations in ELF and AM following intravenous administration of levofloxacin and azithromycin were higher than concentrations in plasma. Further studies are needed to determine the clinical significance of such high intrapulmonary concentrations in patients with respiratory tract infections.

On the validity of travel-time based nonlinear bioreactive transport models in steady-state flow.

PubMed

Sanz-Prat, Alicia; Lu, Chuanhe; Finkel, Michael; Cirpka, Olaf A

2015-01-01

Travel-time based models simplify the description of reactive transport by replacing the spatial coordinates with the groundwater travel time, posing a quasi one-dimensional (1-D) problem and potentially rendering the determination of multidimensional parameter fields unnecessary. While the approach is exact for strictly advective transport in steady-state flow if the reactive properties of the porous medium are uniform, its validity is unclear when local-scale mixing affects the reactive behavior. We compare a two-dimensional (2-D), spatially explicit, bioreactive, advective-dispersive transport model, considered as "virtual truth", with three 1-D travel-time based models which differ in the conceptualization of longitudinal dispersion: (i) neglecting dispersive mixing altogether, (ii) introducing a local-scale longitudinal dispersivity constant in time and space, and (iii) using an effective longitudinal dispersivity that increases linearly with distance. The reactive system considers biodegradation of dissolved organic carbon, which is introduced into a hydraulically heterogeneous domain together with oxygen and nitrate. Aerobic and denitrifying bacteria use the energy of the microbial transformations for growth. We analyze six scenarios differing in the variance of log-hydraulic conductivity and in the inflow boundary conditions (constant versus time-varying concentration). The concentrations of the 1-D models are mapped to the 2-D domain by means of the kinematic (for case i), and mean groundwater age (for cases ii & iii), respectively. The comparison between concentrations of the "virtual truth" and the 1-D approaches indicates extremely good agreement when using an effective, linearly increasing longitudinal dispersivity in the majority of the scenarios, while the other two 1-D approaches reproduce at least the concentration tendencies well. At late times, all 1-D models give valid approximations of two-dimensional transport. We conclude that the conceptualization of nonlinear bioreactive transport in complex multidimensional domains by quasi 1-D travel-time models is valid for steady-state flow fields if the reactants are introduced over a wide cross-section, flow is at quasi steady state, and dispersive mixing is adequately parametrized. Copyright © 2015 Elsevier B.V. All rights reserved.

Permeation of Comite through protective gloves.

PubMed

Zainal, Hanaa; Que Hee, Shane S

2006-09-01

The goal of the study was to assess how protective disposable (Safeskin) and chemical protective (Sol-Vex) nitrile gloves were against Comite emulsifiable concentrate formulation containing propargite (PROP) as active pesticidal ingredient, because there were no explicit recommendations for the gloves that should be worn for hand protection. The glove material was exposed in ASTM-type I-PTC-600 permeation cells at 30.0+/-0.5 degrees C, and gas chromatography-mass spectrometry used for PROP analysis. Aqueous solutions of Comite at 40.4 mg/mL permeated both Safeskin and Sol-Vex nitrile by 8h. Safeskin showed a mean PROP mass permeated of 176+/-27 microg after 8h compared with a mean mass permeated for Sol-Vex of 3.17+/-4.08 microg. Thus, Sol-Vex was about 56 times more protective than Safeskin for an 8-h exposure. However, the kinetics of the permeation revealed that Safeskin can be worn for at least 200 min before disposal. When undiluted Comite challenged both types of nitrile, much faster permeation was observed. Safeskin gloves showed two steady state periods. The first had lag times (t(l)) values of about 1h, although normalized breakthrough times (t(b)) were < 10 min. The second steady state rate (P(s)) was on average four times the rate of the first period, and the second steady state period t(l) was about three times as long as that of the first steady state period, and about the same t(l) as for the aqueous solution. Sol-Vex gloves exposed continuously to undiluted Comite permeated above the normalized breakthrough threshold beyond 2.7h. A risk assessment revealed that the PROP skin permeation rate of 7.1 ng cm(-2)h(-1) was much slower than the first steady state Safeskin glove P(s) of 62,000 ng cm(-2)h(-1). Infrared analysis showed that the glove surfaces were not degraded by the Comite challenge. The chemically protective Sol-Vex gloves protected adequately against undiluted formulation for about 2.7h, whereas they provided protection for nearly 8h when the formulation was diluted with water to the highest concentration for field application. In contrast, the disposable Safeskin gloves did not protect at all for the undiluted formulation, but did for 200 min when the formulation was diluted with water to the highest concentration for spraying.

The Nature of Coping in Treatment for Marijuana Dependence: Latent Structure and Validation of the Coping Strategies Scale

PubMed Central

Litt, Mark D.; Kadden, Ronald M; Tennen, Howard

2012-01-01

The Coping Strategies Scale (CSS) was designed to assess adaptive changes in substance-use specific coping that result from treatment. The present study sought to examine the latent structure of the CSS in the hope that it might shed light on the coping processes of drug users, and guide the development of a brief version of the CSS. Respondents on the CSS were 751 men and women treated in three clinical trials for marijuana dependence. Posttreatment CSS data were analyzed to determine the nature of coping responses in patients who have been trained to use specific strategies to deal with substance use disorders. Exploratory factor analysis yielded two factors, categorized as problem-focused and emotion-focused coping, but confirmatory factor analysis did not support this structure. When infrequently endorsed items were removed, however, confirmatory factor analysis revealed a good fit to the data. Contrary to expectations, practical strategies that often form the basis for coping skills training, such as avoiding those who smoke, were not frequently endorsed. Problem focused items reflected cognitive commitments to change. Emotion-focused items included cognitive reinterpretations of emotions, to help manage emotional reactions. Brief versions of the CSS based on these factors showed good convergent and discriminant validity. The CSS, and the brief versions of the CSS, may prove useful in future treatment trials to evaluate effects of treatment on coping skills acquisition and utilization in substance dependent individuals. PMID:22082345

Seasonal and spatial variabilities in the water chemistry of prairie pothole wetlands influence the photoproduction of reactive intermediates.

PubMed

McCabe, Andrew J; Arnold, William A

2016-07-01

The hydrology and water chemistry of prairie pothole wetlands vary spatially and temporally, on annual and decadal timescales. Pesticide contamination of wetlands arising from agricultural activities is a foremost concern. Photochemical reactions are important in the natural attenuation of pesticides and may be important in limiting ecological and human exposure. Little is known, however, about the variable influence of wetland water chemistry on indirect photochemistry. In this study, seasonal water samples were collected from seven sites throughout the prairie pothole region over three years to understand the spatiotemporal dynamics of reactive intermediate photoproduction. Samples were classified by the season in which they were collected (spring, summer, or fall) and the typical hydroperiod of the wetland surface water (temporary or semi-permanent). Under photostable conditions, steady-state concentrations and apparent quantum yields or quantum yield coefficients were measured for triplet excited states of dissolved organic matter, singlet oxygen, hydroxyl radical, and carbonate radical under simulated sunlight. Steady-state concentrations and quantum yields increased on average by 15% and 40% from spring to fall, respectively. Temporary wetlands had 40% higher steady-state concentrations of reactive intermediates than semi-permanent wetlands, but 50% lower quantum yields. Computed quantum yields for reactive intermediate formation were used to predict the indirect photochemical half-lives of seven pesticides in average temporary and semi-permanent prairie pothole wetlands. As a first approximation, the predictions agree to within two orders of magnitude of previously reported half-lives. Copyright © 2016 Elsevier Ltd. All rights reserved.

Engineering cholesterol-based fibers for antibody immobilization and cell capture

NASA Astrophysics Data System (ADS)

Cohn, Celine

In 2015, the United States is expected to have nearly 600,000 deaths attributed to cancer. Of these 600,000 deaths, 90% will be a direct result of cancer metastasis, the spread of cancer throughout the body. During cancer metastasis, circulating tumor cells (CTCs) are shed from primary tumors and migrate through bodily fluids, establishing secondary cancer sites. As cancer metastasis is incredibly lethal, there is a growing emphasis on developing "liquid biopsies" that can screen peripheral blood, search for and identify CTCs. One popular method for capturing CTCs is the use of a detection platform with antibodies specifically suited to recognize and capture cancer cells. These antibodies are immobilized onto the platform and can then bind and capture cells of interest. However, current means to immobilize antibodies often leave them with drastically reduced function. The antibodies are left poorly suited for cell capture, resulting in low cell capture efficiencies. This body of work investigates the use of lipid-based fibers to immobilize proteins in a way that retains protein function, ultimately leading to increased cell capture efficiencies. The resulting increased efficiencies are thought to arise from the retained three-dimensional structure of the protein as well as having a complete coating of the material surface with antibodies that are capable of interacting with their antigens. It is possible to electrospin cholesterol-based fibers that are similar in design to the natural cell membrane, providing proteins a more natural setting during immobilization. Such fibers have been produced from cholesterol-based cholesteryl succinyl silane (CSS). These fibers have previously illustrated a keen aptitude for retaining protein function and increasing cell capture. Herein the work focuses on three key concepts. First, a model is developed to understand the immobilization mechanism used by electrospun CSS fibers. The antibody immobilization and cell capturing abilities of the CSS fibers were compared to that of hydrophobic polycaprolactone (PCL) fibers and hydrophilic plasma-treated PCL fibers. Electrospun CSS fibers were found to immobilize equivalent amounts of protein as hydrophobically immobilized proteins. However, these proteins captured 6 times more cells, indicative of retained protein function. The second key concept was the design and fabrication of a hybridized lipid fiber. Lipid fibers provide improved protein function but fabrication difficulties have limited their adoption. Thus, we sought to fabricate a lipid-polymer hybrid that is easily fabricated while maintaining protein function. The hybrid fiber consists of a PCL backbone with conjugated CSS. The hybrid lipid fibers showed improved protein function. In addition, higher lipid concentrations were directly correlated to higher cell capture efficiencies. The third key concept was on the development of dually functionalized lipid fibers and understanding the resulting cell capture efficiencies. Many platforms are unable to simultaneously search for heterogeneous populations of CTCs -- the ability to dually functionalize cell-capturing platforms would address this technological weakness. Studies indicated that dually functionalizing the lipid fibers did not compromise the platforms' abilities to capture the cells of interest. Such dually functionalized fibers allow for a single cell-capture platform to successfully detect heterogeneous populations of CTCs. The body of work encompassed herein describes the use of lipid fibers for antibody immobilization and cell capture. Data from various projects indicate that the use of cholesterol-based fibers produced from electrospun CSS are well suited for protein immobilization. The CSS fibers are able to immobilize equivalent amounts of protein as compared to other immobilization techniques. However, the benefit of these fibers is illustrated by the strong cell-capturing efficiencies, indicating that the immobilized proteins are able to retain their function and selectively target cells of interest. The successful immobilization of proteins and their retained function allows for the development of increasingly sensitive cancer diagnostic tools that are able to screen for CTCs early on in the cancer disease cycle.

Implementation of an adaptive controller for the startup and steady-state running of a biomethanation process operated in the CSTR mode.

PubMed

Renard, P; Van Breusegem, V; Nguyen, M T; Naveau, H; Nyns, E J

1991-10-20

An adaptive control algorithm has been implemented on a biomethanation process to maintain propionate concentration, a stable variable, at a given low value, by steering the dilution rate. It was thereby expected to ensure the stability of the process during the startup and during steady-state running with an acceptable performance. The methane pilot reactor was operated in the completely mixed, once-through mode and computer-controlled during 161 days. The results yielded the real-life validation of the adaptive control algorithm, and documented the stability and acceptable performance expected.

Adaptive relaxation for the steady-state analysis of Markov chains

NASA Technical Reports Server (NTRS)

Horton, Graham

1994-01-01

We consider a variant of the well-known Gauss-Seidel method for the solution of Markov chains in steady state. Whereas the standard algorithm visits each state exactly once per iteration in a predetermined order, the alternative approach uses a dynamic strategy. A set of states to be visited is maintained which can grow and shrink as the computation progresses. In this manner, we hope to concentrate the computational work in those areas of the chain in which maximum improvement in the solution can be achieved. We consider the adaptive approach both as a solver in its own right and as a relaxation method within the multi-level algorithm. Experimental results show significant computational savings in both cases.

Acrylamide, 5-hydroxymethylfurfural and N(ε)-carboxymethyl-lysine in coffee substitutes and instant coffees.

PubMed

Loaëc, Grégory; Jacolot, Philippe; Helou, Cynthia; Niquet-Léridon, Céline; Tessier, Frédéric J

2014-04-01

Sensitive analytical methods were developed and validated for the quantification of acrylamide, N(ε)-carboxymethyl-lysine (CML) and 5-hydroxymethylfurfural (HMF) in 24 commercial coffee substitutes (CSs) and 12 instant coffees (ICs). Acrylamide levels varied widely from 200 to 4940 µg kg(-1) with higher levels in CSs. Only two out of 24 CSs had a level of acrylamide above the indicative value set for this food category by the European Commission (4000 µg kg(-1)). None of the ICs tested in this study exceeded the indicative value set for this foodstuff (900 µg kg(-1)). CML ranged from 0.17 to 47 mg kg(-1) and it increased in proportion to the protein content of the samples. The highest concentrations were found in IC partly due to the relatively high protein content of this food group. HMF was the most abundant neoformed compound (NFC) found in the tested commercial samples. It was found between 0.59 and 13 g kg(-1). Among other food categories IC and CS could appear to be major contributors to the exposure to NFCs if consumed on a daily basis. Further investigations are needed to elucidate the acrylamide formation during processing and to determine the daily intake level of frequent consumers of these products.

32 CFR 299.5 - Procedures.

Code of Federal Regulations, 2013 CFR

2013-07-01

... PROGRAM NATIONAL SECURITY AGENCY/CENTRAL SECURITY SERVICE (NSA/CSS) FREEDOM OF INFORMATION ACT PROGRAM § 299.5 Procedures. (a) Requests for copies of records of the NSA/CSS shall be delivered to the Director... Director of Policy, if so designated, shall endeavor to respond to a direct request to NSA/CSS within 20...

32 CFR 299.5 - Procedures.

Code of Federal Regulations, 2012 CFR

2012-07-01

... PROGRAM NATIONAL SECURITY AGENCY/CENTRAL SECURITY SERVICE (NSA/CSS) FREEDOM OF INFORMATION ACT PROGRAM § 299.5 Procedures. (a) Requests for copies of records of the NSA/CSS shall be delivered to the Director... Director of Policy, if so designated, shall endeavor to respond to a direct request to NSA/CSS within 20...

77 FR 38884 - Professional Transportation, Inc.-Asset Acquisition-CUSA ES, LLC and CUSA CSS, LLC

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-29

..., Inc.--CUSA ES, LLC (MC-463168) and CUSA CSS, LLC (MC-522544) (collectively, Coach America Subsidiaries... Transportation, Inc.--Asset Acquisition--CUSA ES, LLC and CUSA CSS, LLC AGENCY: Surface Transportation Board. ACTION: Notice of Finance Application. SUMMARY: Professional Transportation, Inc. (PTI or Applicant), an...

The Autism Diagnostic Observation Schedule, Toddler Module: Standardized Severity Scores

PubMed Central

Esler, Amy N.; Bal, Vanessa Hus; Guthrie, Whitney; Wetherby, Amy; Weismer, Susan Ellis; Lord, Catherine

2016-01-01

Standardized calibrated severity scores (CSS) have been created for Autism Diagnostic Observation Schedule, 2nd edition (ADOS-2) Modules 1–4 as a metric of the relative severity of autism-specific behaviors. Total and domain CSS were created for the Toddler Module to facilitate comparison to other modules. Analyses included 388 children with ASD age 12 to 30 months and were replicated on 435 repeated assessments from 127 children with ASD. Compared to raw scores, associations between total and domain CSS and participant characteristics were reduced in the original sample. Verbal IQ effects on Social Affect-CSS were not reduced in the replication sample. Toddler Module CSS increases comparability of ADOS-2 scores across modules and allows studies of symptom trajectories to extend to earlier ages. PMID:25832801

Acute painless monocular visual loss due to central retinal artery occlusion in a patient with Churg-Strauss vasculitis.

PubMed

Skrapari, Ioanna; Kagkelari, Eleftheria; Charitatos, Evangelos; Pantelidaki, Catherine; Gounaris, Theodoros; Sioula, Evagelia

2008-01-01

Ocular involvement in Churg-Strauss syndrome (CSS) is infrequent. We describe a case of a 50-year-old woman, with blood eosinophilia, involvement of the respiratory tract, skin, and peripheral nervous system, fulfilling the American College of Rheumatology criteria for CSS, who presented with left foot drop followed by left acute painless visual loss. Central retinal artery occlusion was diagnosed by fundoscopic findings (retinal whitening with a cherry-red spot). CSS was confirmed by sural nerve biopsy. Despite treatment with high-dose corticosteroids, cyclophosphamide, and anticoagulant therapy, visual acuity was not substantially improved. Acute blindness in CSS has been rarely described. Even more rarely, central retinal artery occlusion has been found to be the underlying cause of this infrequent clinical manifestation in CSS.

The result of adjuvant chemotherapy for localized pT3 upper urinary tract carcinoma in a multi-institutional study.

PubMed

Kawashima, Atsunari; Nakai, Yasutomo; Nakayama, Masashi; Ujike, Takeshi; Tanigawa, Go; Ono, Yutaka; Kamoto, Akihito; Takada, Tsuyosi; Yamaguchi, Yuichiro; Takayama, Hitoshi; Nishimura, Kazuo; Nonomura, Norio; Tsujimura, Akira

2012-10-01

To determine through the analysis of our multi-institutional database whether postoperative adjuvant chemotherapy for upper urinary tract carcinoma with localized invasive upper urinary tract carcinoma (UUTC) is beneficial. A study population of 93 patients with pT3N0/xM0 UUTC was eligible for this study. Clinical features evaluated were sex, tumor location, adjuvant chemotherapy status, tumor pathology (histology, grade, infiltrating growth, lymphovascular invasion (LVI)), and cause of death. Cancer-specific survival (CSS) was estimated by Kaplan-Meier method. Prognostic factors related to CSS were analyzed by Cox proportional hazards regression model for multivariate analysis. In pT3 patients, overall 5-year CSS rate was 68.4% and median CSS time was 31 months (range 3-114 months). In the adjuvant chemotherapy group, 5-year CSS rate was 80.8%, whereas 5-year CSS rate was 64.4% in the non-adjuvant chemotherapy group. By multivariate analysis, adjuvant chemotherapy status was significantly associated with CSS (P = 0.008) were sex, tumor grade, tumor histology, and LVI presence. This study, although it was retrospective study, revealed that adjuvant chemotherapy after RNU may be beneficial in pT3N0/X patients by multivariate analysis. Prospective studies evaluating adjuvant therapy regimens for UTTC are required.

Temperature dependent of IVR investigated by steady-state and time-frequency resolved CARS for liquid nitrobenzene and nitromethane

NASA Astrophysics Data System (ADS)

Yang, Yanqiang; Zhu, Gangbei; Yan, Lin; Liu, Xiaosong; Yang's Ultrafast Spectroscopy Group Team

2017-06-01

Intramolecular vibrational energy redistribution (IVR) is important process in thermal decomposition, shock chemistry and photochemistry. Anti-Stokes Raman scattering is sensitive to the vibrational population in excited states because only vibrational excited states are responsible to the anti-Stokes Raman scattering, does not vibrational ground states. In this report, steady-state anti-Stokes Raman spectroscopy and broad band ultrafast coherent anti-Stokes Raman scattering (CARS) are performed. The steady-state anti-Stokes Raman spectroscopy shows temperature dependent of vibrational energy redistribution in vibrational excited-state molecule, and reveal that, in liquid nitrobenzene, with temperature increasing, vibrational energy is mainly redistributed in NO2 symmetric stretching mode, and phenyl ring stretching mode of νCC. For liquid nitromethane, it is found that, with temperature increasing, vibrational energy concentrate in CN stretching mode and methyl umbrella vibrational mode. In the broad band ultrafast CARS experiment, multiple vibrational modes are coherently excited to vibrational excited states, and the time-frequency resolved CARS spectra show the coincident IVR processes. This work is supported by the National Natural Science Foundation of China (Grant Numbers 21673211 and 11372053), and the Science Challenging Program (Grant Number JCKY2016212A501).

40 CFR 91.301 - Scope; applicability.

Code of Federal Regulations, 2010 CFR

2010-07-01

... this part 91. (b) Exhaust gases are sampled while the test engine is operated using a steady state test... analysis determining concentration of pollutant, exhaust volume, the fuel flow, and the power output during...

Minority-carrier lifetime in InP as a function of light bias

NASA Technical Reports Server (NTRS)

Yater, Jane A.; Weinberg, I.; Jenkins, Phillip P.; Landis, Geoffrey A.

1995-01-01

Minority-carrier lifetime in InP is studied as a function of doping level and laser intensity using time-resolved photoluminescence. A continuous wave diode laser illuminates bulk InP and acts as a light bias, injecting a steady-state concentration of carriers. A 200 ps laser pulse produces a small transient signal on top of the steady-state luminescence, allowing lifetime to be measured directly as a function of incident intensity. For p-InP, lifetime increases with light bias up to a maximum value. Bulk recombination centers are presumably filled to saturation, allowing minority carriers to live longer. The saturation bias scales with dopant concentration for a particular dopant species. As light bias is increased for n-InP, minority-carrier lifetime increases slightly but then decreases, suggesting radiative recombination as a dominant decay mechanism.

Modeling and experimental examination of water level effects on radon exhalation from fragmented uranium ore.

PubMed

Ye, Yong-Jun; Dai, Xin-Tao; Ding, De-Xin; Zhao, Ya-Li

2016-12-01

In this study, a one-dimensional steady-state mathematical model of radon transport in fragmented uranium ore was established according to Fick's law and radon transfer theory in an air-water interface. The model was utilized to obtain an analytical solution for radon concentration in the air-water, two-phase system under steady state conditions, as well as a corresponding radon exhalation rate calculation formula. We also designed a one-dimensional experimental apparatus for simulating radon diffusion migration in the uranium ore with various water levels to verify the mathematical model. The predicted results were in close agreement with the measured results, suggesting that the proposed model can be readily used to determine radon concentrations and exhalation rates in fragmented uranium ore with varying water levels. Copyright © 2016. Published by Elsevier Ltd.

Two-dimensional description of surface-bounded exospheres with application to the migration of water molecules on the Moon

NASA Astrophysics Data System (ADS)

Schorghofer, Norbert

2015-05-01

On the Moon, water molecules and other volatiles are thought to migrate along ballistic trajectories. Here, this migration process is described in terms of a two-dimensional partial differential equation for the surface concentration, based on the probability distribution of thermal ballistic hops. A random-walk model, a corresponding diffusion coefficient, and a continuum description are provided. In other words, a surface-bounded exosphere is described purely in terms of quantities on the surface, which can provide computational and conceptual advantages. The derived continuum equation can be used to calculate the steady-state distribution of the surface concentration of volatile water molecules. An analytic steady-state solution is obtained for an equatorial ring; it reveals the width and mass of the pileup of molecules at the morning terminator.

Pharmacometrics-based dose selection of levofloxacin as a treatment for postexposure inhalational anthrax in children.

PubMed

Li, Fang; Nandy, Partha; Chien, Shuchean; Noel, Gary J; Tornoe, Christoffer W

2010-01-01

Levofloxacin was recently (May 2008) approved by the U.S. Food and Drug Administration as a treatment for children following inhalational exposure to anthrax. Given that no clinical trials to assess the efficacy of a chosen dose was conducted, the basis for the dose recommendation was based upon pharmacometric analyses. The objective of this paper is to describe the basis of the chosen pediatric dose recommended for the label. Pharmacokinetic (PK) data from 90 pediatric patients receiving 7 mg/kg of body weight levofloxacin and two studies of 47 healthy adults receiving 500 and 750 mg/kg levofloxacin were used for the pharmacometric analyses. Body weight was found to be a significant covariate for levofloxacin clearance and the volume of distribution. Consistently with developmental physiology, clearance also was found to be reduced in pediatric patients under 2 years of age due to immature renal function. Different dosing regimens were simulated to match adult exposure (area under the concentration-time curve from 0 to 24 h at steady state, maximum concentration of drug in serum at steady state, and minimum concentration of drug in serum at steady state) following the approved adult dose of 500 mg once a day. The recommended dose of 8 mg/kg twice a day was found to match the exposure of the dose approved for adults in a manner that permitted confidence that this dose in children would achieve efficacy comparable to that of adults.

Uncovering glacier dynamics beneath a debris mantle

NASA Astrophysics Data System (ADS)

Lefeuvre, P.-M.; Ng, F. S. L.

2012-04-01

Debris-covered glaciers (DCGs) have an extensive sediment mantle whose low albedo influences their surface energy balance to cause a buffering effect that could enhance or reduce ablation rates depending on the sediment thickness. The last effect suggests that some DCGs may be less sensitive to climate change and survive for longer than debris-free (or 'clean') glaciers under sustained climatic warming. However, the origin of DCGs is debated and the precise impact of the debris mantle on their flow dynamics and surface geometry has not been quantified. Here we investigate these issues with a numerical model that encapsulates ice-flow physics and surface debris evolution and transport along a glacier flow-line, as well as couples these with glacier mass balance. We model the impact of surface debris on ablation rates by a mathematical function based on published empirical data (including Ostrem's curve). A key interest is potential positive feedback of ablation on debris thickening and lowering of surface albedo. Model simulations show that when DCGs evolve to attain steady-state profiles, they reach lower elevations than clean glaciers do for the same initial and climatic conditions. Their mass-balance profile at steady state displays an inversion near the snout (where the debris cover is thickest) that is not observed in the clean-glacier simulations. In these cases, where the mantle causes complete buffering to inhibit ablation, the DCG does not reach a steady-state profile, and the sediment thickness evolves to a steady value that depends sensitively on the glacier surface velocities. Variation in the assumed englacial debris concentration in our simulations also determines glacier behaviour. With low englacial debris concentration, the DCG retreats initially while its mass-balance gradient steepens, but the glacier re-advances if it subsequently builds up a thick enough debris cover to cause complete buffering. We identify possible ways and challenges of testing this model with field observations of DCGs, given the inherent difficulty that such glaciers may not be in steady state.

Th1/Th2 balance and humoral immune response to potential antigens as early diagnostic method of equine Strongylus nematode infection.

PubMed

Abo-Aziza, Faten A M; Hendawy, Seham H M; Namaky, Amira H El; Ashry, Heba M

2017-06-01

The aim of this study was to investigate the early diagnosis of strongyle infection based on early changes in Th1 and Th2 cytokines beside the diagnostic accuracy values and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and western blotting profiles using prepared strongyles antigens. A total of 73 donkeys had a mean age of 4-32 years old were parasitologically examined for strongyle infection. The early changes in Th1 and Th2 cytokines were determined, and the diagnostic accuracy values and SDS-PAGE and western blotting profiles were performed using prepared strongyles antigens; crude somatic Strongylus vulgaris (CSS), excretory-secretory S. vulgaris (ESS), crude somatic Cyathostomins (CSC), and excretory-secretory Cyathostomins (ESC). The results revealed highest 437.04% and lowest 37.81% immunoglobulin G (IgG) in high and low egg shedder groups when using ESC and CSS antigens, respectively. Antibodies index for ESS and CSC were significantly higher in moderate egg shedder group while that for ESS and CSC, ESC was significantly higher in high egg shedder group. Tumor necrosis factor alpha (TNF-α)/interleukin-4 (IL-4) balance in S. vulgaris infected donkeys was approximately equal in apparently healthy, low and high egg shedder groups while TNF-α < IL-4 in moderate egg shedder. In Cyathostomins infected animals, TNF-α/IL-4 balance was approximately equal in apparently healthy group while it was low in moderate and high egg shedder groups. The diagnostic accuracy showed that the higher specificity (46.6%) and prevalence (95.40%) were recorded by CSS and ESC antigens, respectively. However, SDS-PAGE and western blotting profiling proved that the band at molecular weight 25 kDa is exhibited by CSS antigen. Combination of detecting level of TNF-α/IL-4 balance, CSS antigen and IgG concentration is good tool for appropriate diagnosis of such infection. More advancement research must be done concerning Th1/Th2 balance and cross-reactivity of S. vulgaris and Cyathostomins spp. at the base of serological and molecular investigation.

Th1/Th2 balance and humoral immune response to potential antigens as early diagnostic method of equine Strongylus nematode infection

PubMed Central

Abo-Aziza, Faten A. M.; Hendawy, Seham H. M.; Namaky, Amira H. El; Ashry, Heba M.

2017-01-01

Aim:: The aim of this study was to investigate the early diagnosis of strongyle infection based on early changes in Th1 and Th2 cytokines beside the diagnostic accuracy values and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and western blotting profiles using prepared strongyles antigens. Materials and Methods:: A total of 73 donkeys had a mean age of 4-32 years old were parasitologically examined for strongyle infection. The early changes in Th1 and Th2 cytokines were determined, and the diagnostic accuracy values and SDS-PAGE and western blotting profiles were performed using prepared strongyles antigens; crude somatic Strongylus vulgaris (CSS), excretory-secretory S. vulgaris (ESS), crude somatic Cyathostomins (CSC), and excretory-secretory Cyathostomins (ESC). Results:: The results revealed highest 437.04% and lowest 37.81% immunoglobulin G (IgG) in high and low egg shedder groups when using ESC and CSS antigens, respectively. Antibodies index for ESS and CSC were significantly higher in moderate egg shedder group while that for ESS and CSC, ESC was significantly higher in high egg shedder group. Tumor necrosis factor alpha (TNF-α)/interleukin-4 (IL-4) balance in S. vulgaris infected donkeys was approximately equal in apparently healthy, low and high egg shedder groups while TNF-α < IL-4 in moderate egg shedder. In Cyathostomins infected animals, TNF-α/IL-4 balance was approximately equal in apparently healthy group while it was low in moderate and high egg shedder groups. The diagnostic accuracy showed that the higher specificity (46.6%) and prevalence (95.40%) were recorded by CSS and ESC antigens, respectively. However, SDS-PAGE and western blotting profiling proved that the band at molecular weight 25 kDa is exhibited by CSS antigen. Conclusion:: Combination of detecting level of TNF-α/IL-4 balance, CSS antigen and IgG concentration is good tool for appropriate diagnosis of such infection. More advancement research must be done concerning Th1/Th2 balance and cross-reactivity of S. vulgaris and Cyathostomins spp. at the base of serological and molecular investigation. PMID:28717322

Direct determination of uranium in seawater by laser fluorimetry.

PubMed

Kumar, Sanjukta A; Shenoy, Niyoti S; Pandey, Shailaja; Sounderajan, Suvarna; Venkateswaran, G

2008-10-19

A method for estimation of uranium in seawater by using steady state laser flourimetry is described. Uranium present in seawater, in concentration of approximately 3 ng ml(-1) was estimated without prior separation of matrix. Quenching effect of major ions (Cl(-), Na(+), SO(4)(-), Mg(+), Ca(+), K(+), HCO(3)(-), Br(-)) present in seawater on fluorescence intensity of uranium was studied. The concentration of phosphoric acid required for maximum enhancement of fluorescence intensity was optimized and was found to be 5%. Similarly the volume of concentrated nitric acid required to eliminate the quenching effect of chloride and bromide completely from 5 ml of seawater were optimized and was found to be 3 ml. A simple equation was derived using steady state fluorescence correction method and was used for calculation of uranium concentration in seawater samples. The method has a precesion of 1% (1s, n=3). The values obtained from laser fluorimetry were validated by analyzing the same samples by linear sweep adsorptive stripping voltametry (LSASV) of the uranium-chloranilic acid (2,5-dichloro-3,6-dihydroxy-1,4-benzoquinone) complex. Both the values are well in agreement.

Divacancy-hydrogen complexes in dislocation-free high-purity germanium. [Annealing, Hall effect, steady-state concentration energy dependence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haller, E.E.; Hubbard, G.S.; Hansen, W.L.

1976-09-01

A defect center with a single acceptor level at E/sub v/ + 0.08 eV appears in H/sub 2/-grown dislocation-free high-purity germanium. Its concentration changes reversibly upon annealing up to 650 K. By means of Hall-effect and conductivity measurements over a large temperature range the temperature dependence of the steady-state concentration between 450 and 720 K as well as the transients following changes in temperature were determined. The observed acceptor level is attributed to the divacancy-hydrogen complex V/sub 2/H. The complex reacts with hydrogen, dissolved in the Ge lattice or stored in traps, according to V/sub 2/H + H reversible V/submore » 2/H/sub 2/. An energy level associated with the divacancy-dihydrogen complex was not observed. These results are in good agreement with the idea that hydrogen in germanium forms a ''very deep donor'' (i.e., the energy level lies inside the valence band).« less

Corrective Action Management Unit Report of Post-Closure Care Activities Calendar Year 2017.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ziock, Robert; Little, Bonnie Colleen

The Corrective Action Management Unit (CAMU) at Sandia National Laboratories, New Mexico (SNL/NM) consists of a containment cell and ancillary systems that underwent regulatory closure in 2003 in accordance with the Closure Plan in Appendix D of the Class 3 Permit Modification (SNL/NM September 1997). The containment cell was closed with wastes in place. On January 27, 2015, the New Mexico Environment Department (NMED) issued the Hazardous Waste Facility Operating Permit (Permit) for Sandia National Laboratories (NMED January 2015). The Permit became effective February 26, 2015. The CAMU is undergoing post-closure care in accordance with the Permit, as revised andmore » updated. This CAMU Report of Post-Closure Care Activities documents all activities and results for Calendar Year (CY) 2017 as required by the Permit. The CAMU containment cell consists of engineered barriers including a cover system, a bottom liner with a leachate collection and removal system (LCRS), and a vadose zone monitoring system (VZMS). The VZMS provides information on soil conditions under the cell for early leak detection. The VZMS consists of three monitoring subsystems, which include the primary subliner (PSL), a vertical sensor array (VSA), and the Chemical Waste Landfill (CWL) sanitary sewer (CSS) line. The PSL, VSA, and CSS monitoring subsystems are monitored quarterly for soil moisture concentration, the VSA is monitored quarterly for soil temperature, and the VSA and CSS monitoring subsystems are monitored annually for volatile organic compound (VOC) concentrations in the soil vapor at various depths. Baseline data for the soil moisture, soil temperature, and soil vapor were established between October 2003 and September 2004.« less

Non steady-state descriptions of drug permeation through stratum corneum. I. The biphasic brick-and-mortar model.

PubMed

Heisig, M; Lieckfeldt, R; Wittum, G; Mazurkevich, G; Lee, G

1996-03-01

The diffusion equation should be solved for the non-steady-state problem of drug diffusion within a two-dimensional, biphasic stratum corneum membrane having homogeneous lipid and corneocyte phases. A numerical method was developed for a brick-and-mortar SC-geometry, enabling an explicit solution for time-dependent drug concentration within both phases. The lag time and permeability were calculated. It is shown how the barrier property of this model membrane depends on relative phase permeability, corneocyte alignment, and corneocyte-lipid partition coefficient. Additionally, the time-dependent drug concentration profiles within the membrane can be observed during the lag and steady-state phases. The model SC-membrane predicts, from purely morphological principles, lag times and permeabilities that are in good agreement with experimental values. The long lag times and very small permeabilities reported for human SC can only be predicted for a highly-staggered corneocyte geometry and corneocytes that are 1000 times less permeable than the lipid phase. Although the former conclusion is reasonable, the latter is questionable. The elongated, flattened corneocyte shape renders lag time and permeability insensitive to large changes in their alignment within the SC. Corneocyte/lipid partitioning is found to be fundamentally different to SC/donor partitioning, since increasing drug lipophilicity always reduces both lag time and permeability.

[Comparative studies on the bioavailability of nicergoline from two different steady-state preparations].

PubMed

Kohlenberg-Müller, K; Meier, D H; Kunz, K; Wauschkuhn, C H; Schaffler, K

1991-07-01

Comparative Studies on the Bioavailability of Nicergoline from Two Different Preparations in Steady State The bioavailability of nicergoline (CAS 27848-84-6) in a new 30 mg tablet and a 10 mg dragee formulation (Sermion) was evaluated under steady state conditions in 18 healthy male volunteers between the age of 21 and 37 years. During the run-in phase, the volunteers received on 7 consecutive days 30 mg nicergoline either 1 x 30 mg/d tablet (test substance) or 3 x 10 mg dragees (reference). On day 8, after intake of 1 x 30 mg in a 24 h interval or 1 x 10 mg in a 8 h interval respectively, the plasma concentrations of the nicergoline metabolite 10-methoxy-6-methyl-ergoline-8 beta-methanol (MDL) were measured. The area under the plasma concentrations in the 24 h interval after administering the 30 mg tablet was not 3 times greater as to be expected; it was by a factor of 4 significantly greater than the area under the curve of the 10 mg dragee in the 8 h interval. Therefore, nicergoline has a higher availability in the 30 mg tablet than in the 10 mg dragee form. Both formulations were equally well tolerated.

Confounding of the Association between Radiation Exposure from CT Scans and Risk of Leukemia and Brain Tumors by Cancer Susceptibility Syndromes.

PubMed

Meulepas, Johanna M; Ronckers, Cécile M; Merks, Johannes; Weijerman, Michel E; Lubin, Jay H; Hauptmann, Michael

2016-01-01

Recent studies linking radiation exposure from pediatric computed tomography (CT) to increased risks of leukemia and brain tumors lacked data to control for cancer susceptibility syndromes (CSS). These syndromes might be confounders because they are associated with an increased cancer risk and may increase the likelihood of CT scans performed in children. We identify CSS predisposing to leukemia and brain tumors through a systematic literature search and summarize prevalence and risk estimates. Because there is virtually no empirical evidence in published literature on patterns of CT use for most types of CSS, we estimate confounding bias of relative risks (RR) for categories of radiation exposure based on expert opinion about the current and previous patterns of CT scans among CSS patients. We estimate that radiation-related RRs for leukemia are not meaningfully confounded by Down syndrome, Noonan syndrome, or other CSS. In contrast, RRs for brain tumors may be overestimated due to confounding by tuberous sclerosis complex (TSC) while von Hippel-Lindau disease, neurofibromatosis type 1, or other CSS do not meaningfully confound. Empirical data on the use of CT scans among CSS patients are urgently needed. Our assessment indicates that associations with leukemia reported in previous studies are unlikely to be substantially confounded by unmeasured CSS, whereas brain tumor risks might have been overestimated due to confounding by TSC. Future studies should identify TSC patients in order to avoid overestimation of brain tumor risks due to radiation exposure from CT scans. ©2015 American Association for Cancer Research.

Recent Advances and Achievements at The Catalina Sky Survey

NASA Astrophysics Data System (ADS)

Leonard, Gregory J.; Christensen, Eric J.; Fuls, Carson; Gibbs, Alex; Grauer, Al; Johnson, Jess A.; Kowalski, Richard; Larson, Stephen M.; Matheny, Rose; Seaman, Rob; Shelly, Frank

2017-10-01

The Catalina Sky Survey (CSS) is a NASA-funded project fully dedicated to discover and track near-Earth objects (NEOs). Since its founding nearly 20 years ago CSS remains at the forefront of NEO surveys, and recent improvements in both instrumentation and software have increased both survey productivity and data quality. In 2016 new large-format (10K x 10K) cameras were installed on both CSS survey telescopes, the 1.5-m reflector and the 0.7-m Schmidt, increasing the field of view, and hence nightly sky coverage by 4x and 2.4x respectively. The new cameras, coupled with improvements in the reduction and detection pipelines, and revised sky-coverage strategies have yielded a dramatic upward trend of NEO discovery rates. CSS has also developed a custom adaptive queue manager for scheduling NEO follow-up astrometry using a remotely operated and recently renovated 1-m Cassegrain reflector telescope, improvements that have increased the production of follow-up astrometry for newly discovered NEOs and arc extensions for previously discovered objects by CSS and other surveys. Additionally, reprocessing of archival CSS data (which includes some 46 million individual astrometric measurements) through the new reduction and detection pipeline will allow for improved orbit determinations and increased arc extensions for hundreds of thousands of asteroids. Reprocessed data will soon feed into a new public archive of CSS images and catalog data products made available through NASA’s Planetary Data System (PDS). For the future, CSS is working towards improved NEO follow-up capabilities through a combination of access to larger telescopes, instrument upgrades and follow-up scheduling tools.

Interleukin-25: a cytokine linking eosinophils and adaptive immunity in Churg-Strauss syndrome.

PubMed

Terrier, Benjamin; Bièche, Ivan; Maisonobe, Thierry; Laurendeau, Ingrid; Rosenzwajg, Michèlle; Kahn, Jean-Emmanuel; Diemert, Marie-Claude; Musset, Lucile; Vidaud, Michel; Sène, Damien; Costedoat-Chalumeau, Nathalie; Le Thi-Huong, Du; Amoura, Zahir; Klatzmann, David; Cacoub, Patrice; Saadoun, David

2010-11-25

Churg-Strauss syndrome (CSS) is characterized by systemic vasculitis and blood and tissue eosinophilia. Blood eosinophilia correlates with disease activity, and activated T cells from CSS patients are predominantly T helper 2 (Th2). Interleukin (IL)-25 has been shown to link innate and adaptive immunity by enhancing Th2 cytokine production. We sought to determine the involvement of IL-25 and its receptor IL-17RB in the pathogenesis of CSS. We found increased levels of IL-25 in the serum of active CSS patients (952 ± 697 vs 75 ± 49 pg/mL in inactive patients and 47 ± 6 pg/mL in healthy donors). IL-25 was correlated with disease activity and eosinophil level. Eosinophils were the main source of IL-25, whereas activated CD4(+) memory T cells were the IL-17RB-expressing cells in CSS. IL-25 enhanced the production of IL-4, IL-5, and IL-13 by activated peripheral blood mononuclear cells. IL-25 and IL-17RB were observed within the vasculitic lesions of patients with CSS, and IL-17RB colocalized with T cells. Increased expression of IL-17RB, tumor necrosis factor receptor-associated factor 6, and JunB in vasculitic lesions of CSS underscored the IL-25-mediated activation, whereas up-regulation of GATA3 and IL-10 supported Th2 differentiation. Our findings suggest that eosinophils, through the production of IL-25, exert a critical role in promoting Th2 responses in target tissues of CSS.

75 FR 21250 - Privacy Act of 1974; Systems of Records

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-23

... information of the current tenants of NSA/CSS facilities; to create and track the status of visit requests and... facility; to track inside the NSA/CSS facility authorized NSA/CSS employee and visitor badges as they are used to pass through automated turnstile system, access office suites and other work areas; to track...

Fibromyalgia and overlapping disorders: the unifying concept of central sensitivity syndromes.

PubMed

Yunus, Muhammad B

2007-06-01

To discuss fibromyalgia syndrome (FMS) and overlapping conditions, eg, irritable bowel syndrome, headaches, and chronic fatigue syndrome, within the concept of central sensitivity syndromes (CSS). A critical overview of the literature and incorporation of the author's own views. The concept of CSS seems viable. It is based on mutual associations among the CSS conditions as well as the evidence for central sensitization (CS) among several CSS members. However, such evidence is weak or not available in other members at this time, requiring further studies. The biology of CSS is based on neuroendocrine aberrations, including CS, that interact with psychosocial factors to cause a number of symptoms. CSS is an important new concept that embraces the biopsychosocial model of disease. Further critical studies are warranted to fully test this concept. However, it seems to have important significance for new directions for research and patient care involving physician and patient education. Each patient, irrespective of diagnosis, should be treated as an individual considering both the biological and psychosocial contributions to his or her symptoms and suffering.

A simple method for verifying the deployment of the TOMS-EP solar arrays

NASA Technical Reports Server (NTRS)

Koppersmith, James R.; Ketchum, Eleanor

1995-01-01

The Total Ozone Mapping Spectrometer-Earth Probe (TOMS-EP) mission relies upon a successful deployment of the spacecraft's solar arrays. Several methods of verification are being employed to ascertain the solar array deployment status, with each requiring differing amounts of data. This paper describes a robust attitude-independent verification method that utilizes telemetry from the coarse Sun sensors (CSS's) and the three-axis magnetometers (TAM's) to determine the solar array deployment status - and it can do so with only a few, not necessarily contiguous, points of data. The method developed assumes that the solar arrays are deployed. Telemetry data from the CSS and TAM are converted to the Sun and magnetic field vectors in spacecraft body coordinates, and the angle between them is calculated. Deployment is indicated if this angle is within a certain error tolerance of the angle between the reference Sun and magnetic field vectors. Although several other methods can indicate a non-deployed state, with this method there is a 70% confidence level in confirming deployment as well as a nearly 100% certainty in confirming a non-deployed state. In addition, the spacecraft attitude (which is not known during the first orbit after launch) is not needed for this algorithm because the angle between the Sun and magnetic field vectors is independent of the spacecraft attitude. This technique can be applied to any spacecraft with a TAM and with CSS's mounted on the solar array(s).

Effect of ventilation rate and board loading on formaldehyde concentration : a critical review of the literature

Treesearch

George E. Myers

1984-01-01

A critical literature review has been carried out on the influence of ventilation rate (N, hr.-1) and board loading (L, m2/m3) on steady state formaldehyde concentrations (Cs, ppm) resulting from particleboard and plywood emissions. Large differences exist among boards in the extent to which their formaldehyde concentrations change with N or L in laboratory chambers....

Photochemical Production of Singlet Oxygen from Dissolved Organic Matter in Ice.

PubMed

Fede, Alexis; Grannas, Amanda M

2015-11-03

Dissolved natural organic matter (DOM) is a ubiquitous component of natural waters and an important photosensitizer. A variety of reactive oxygen species (ROS) are known to be produced from DOM photochemistry, including singlet oxygen, 1O2. Recently, it has been determined that humic-like substances and unknown organic chromophores are significant contributors to sunlight absorption in snowpack; however, DOM photochemistry in snow/ice has received little attention in the literature. We recently showed that DOM plays an important role in indirect photolysis processes in ice, producing ROS and leading to the efficient photodegradation of a probe hydrophobic organic pollutant, aldrin.1 ROS scavenger experiments indicated that 1O2 played a significant role in the indirect photodegradation of aldrin. Here we quantitatively examine 1O2 photochemically produced from DOM in frozen and liquid aqueous solutions. Steady-state 1O2 production is enhanced up to nearly 1000 times in frozen DOM samples compared to liquid samples. 1O2 production is dependent on the concentration of DOM, but the nature of the DOM source (terrestrial vs microbial) does not have a significant effect on 1O2 production in liquid or frozen samples, with different source types producing similar steady-state concentrations of 1O2. The temperature of frozen samples also has a significant effect on steady-state 1O2 production in the range of 228-262 K, with colder samples producing more steady-state 1O2. The large enhancement in 1O2 in frozen samples suggests that it may play a significant role in the photochemical processes that occur in snow and ice, and DOM could be a significant, but to date poorly understood, oxidant source in snow and ice.

Chamber measurement of surface-atmosphere trace gas exchange--Numerical evaluation of dependence on soil interfacial layer, and source/sink products

USGS Publications Warehouse

Hutchinson, G.L.; Livingston, G.P.; Healy, R.W.; Striegl, Robert G.

2000-01-01

We employed a three-dimensional finite difference gas diffusion model to simulate the performance of chambers used to measure surface-atmosphere tace gas exchange. We found that systematic errors often result from conventional chamber design and deployment protocols, as well as key assumptions behind the estimation of trace gas exchange rates from observed concentration data. Specifically, our simulationshowed that (1) when a chamber significantly alters atmospheric mixing processes operating near the soil surface, it also nearly instantaneously enhances or suppresses the postdeployment gas exchange rate, (2) any change resulting in greater soil gas diffusivity, or greater partitioning of the diffusing gas to solid or liquid soil fractions, increases the potential for chamber-induced measurement error, and (3) all such errors are independent of the magnitude, kinetics, and/or distribution of trace gas sources, but greater for trace gas sinks with the same initial absolute flux. Finally, and most importantly, we found that our results apply to steady state as well as non-steady-state chambers, because the slow rate of gas diffusion in soil inhibits recovery of the former from their initial non-steady-state condition. Over a range of representative conditions, the error in steady state chamber estimates of the trace gas flux varied from -30 to +32%, while estimates computed by linear regression from non-steadystate chamber concentrations were 2 to 31% too small. Although such errors are relatively small in comparison to the temporal and spatial variability characteristic of trace gas exchange, they bias the summary statistics for each experiment as well as larger scale trace gas flux estimates based on them.

Root-Zone-Specific Oxygen Tolerance of Azospirillum spp. and Diazotrophic Rods Closely Associated with Kallar Grass.

PubMed

Hurek, T; Reinhold, B; Fendrik, I; Niemann, E G

1987-01-01

The effect of oxygen on N(2)-dependent growth of two Azospirillum strains and two diazotrophic rods closely associated with roots of Kallar grass (Leptochloa fusca) was studied. To enable precise comparison, bacteria were grown in dissolved-oxygen-controlled batch and continuous cultures. Steady states were obtained from about 1 to 30 muM O(2), some of them being carbon limited. All strains needed a minimum amount of oxygen for N(2)-dependent growth. Nitrogen contents between 10 and 13% of cell dry weight were observed. The response of steady-state cultures to increasing O(2) concentrations suggested that carbon limitation shifted to internal nitrogen limitation when N(2) fixation became so low that the bacteria could no longer meet their requirements for fixed nitrogen. For Azospirillum lipoferum Rp5, increase of the dilution rate resulted in decreased N(2) fixation in steady-state cultures with internal nitrogen limitation. Oxygen tolerance was found to be strain specific in A. lipoferum with strain Sp59b as a reference organism. Oxygen tolerance of strains from Kallar grass was found to be root zone specific. A. halopraeferens Au 4 and A. lipoferum Rp5, predominating on the rhizoplane of Kallar grass, and strains H6a2 and BH72, predominating in the endorhizosphere, differed in their oxygen tolerance profiles. Strains H6a2 and BH72 still grew and fixed nitrogen in steady-state cultures at O(2) concentrations exceeding those which absolutely inhibited nitrogen fixation of both Azospirillum strains. It is proposed that root-zone-specific oxygen tolerance reflects an adaptation of the isolates to the microenvironments provided by the host plant.

Accuracy of non-invasive measurement of haemoglobin concentration by pulse co-oximetry during steady-state and dynamic conditions in liver surgery.

PubMed

Vos, J J; Kalmar, A F; Struys, M M R F; Porte, R J; Wietasch, J K G; Scheeren, T W L; Hendriks, H G D

2012-10-01

The Masimo Radical 7 (Masimo Corp., Irvine, CA, USA) pulse co-oximeter(®) calculates haemoglobin concentration (SpHb) non-invasively using transcutaneous spectrophotometry. We compared SpHb with invasive satellite-lab haemoglobin monitoring (Hb(satlab)) during major hepatic resections both under steady-state conditions and in a dynamic phase with fluid administration of crystalloid and colloid solutions. Thirty patients undergoing major hepatic resection were included and randomized to receive a fluid bolus of 15 ml kg(-1) colloid (n=15) or crystalloid (n=15) solution over 30 min. SpHb was continuously measured on the index finger, and venous blood samples were analysed in both the steady-state phase (from induction until completion of parenchymal transection) and the dynamic phase (during fluid bolus). Correlation was significant between SpHb and Hb(satlab) (R(2)=0.50, n=543). The modified Bland-Altman analysis for repeated measurements showed a bias (precision) of -0.27 (1.06) and -0.02 (1.07) g dl(-1) for the steady-state and dynamic phases, respectively. SpHb accuracy increased when Hb(satlab) was <10 g dl(-1), with a bias (precision) of 0.41 (0.47) vs -0.26 (1.12) g dl(-1) for values >10 g dl(-1), but accuracy decreased after colloid administration (R(2)=0.25). SpHb correlated moderately with Hb(satlab) with a slight underestimation in both phases in patients undergoing major hepatic resection. Accuracy increased for lower Hb(satlab) values but decreased in the presence of colloid solution. Further improvements are necessary to improve device accuracy under these conditions, so that SpHb might become a sensitive screening device for clinically significant anaemia.

Combined Churg-Strauss syndrome and allergic bronchopulmonary aspergillosis - case report and review of the literature.

PubMed

Ren, Shaohua

2013-01-01

A rare case of combined Churg-Strauss syndrome (CSS) and allergic bronchopulmonary aspergillosis (ABPA) was presented. A 41-year-old woman was diagnosed with CSS based upon asthma, eosinophilia (23%), chest radiographic findings, paranasal sinusitis, peripheral neuropathy and positive p- anti-neutrophil cytoplasmic antibodies (pANCA). The diagnosis of ABPA was established on the pathological findings of allegic mucin impaction and fungal hyphae on lung biopsy. It was further proved by positive serum IgE and IgG antibodies specific to afumigatus. The clinical investigation features were reviewed in the patients with combined CSS and ABPA. All patients had the time sequence of the development of CSS after ABPA uniformly, suggesting immunopathogenesis involving the emergence of CSS. The role of lung biopsy in the diagnosis of the condition was emphasized. © 2012 Blackwell Publishing Ltd.

Centaur Standard Shroud (CSS) cryogenic unlatch tests

NASA Technical Reports Server (NTRS)

1973-01-01

Cryogenic tanking and partial jettison (unlatch) tests were performed on a full scale Centaur vehicle and Centaur Standard Shroud (CSS) to develop and qualify the CSS insulation system, the CSS and Centaur ground-hold purge systems, and the Centaur hydrogen tank flight vent system. Operation of the shroud/Centaur pyrotechnic systems, seals, and the shroud jettison springs, hinges, and other separation systems was demonstrated by a partial jettison of the shroud into catch nets. The Centaur tanks were filled with liquid hydrogen and liquid nitrogen. Prelaunch operations were performed, and data taken to establish system performances. Results from the initial tests showed a higher than expected heat transfer rate to the Centaur hydrogen tank. In addition, the release mechanism for the forward seal between the Centaur and the CSS did not function properly, and the seal was torn during jettison of the shroud.

Trends in the Utilization of Brachytherapy in Cervical Cancer in the United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, Kathy, E-mail: Kathy.Han@rmp.uhn.on.ca; Milosevic, Michael; Fyles, Anthony

2013-09-01

Purpose: To determine the trends in brachytherapy use in cervical cancer in the United States and to identify factors and survival benefits associated with brachytherapy treatment. Methods and Materials: Using the Surveillance, Epidemiology, and End Results (SEER) database, we identified 7359 patients with stages IB2-IVA cervical cancer treated with external beam radiation therapy (EBRT) between 1988 and 2009. Propensity score matching was used to adjust for differences between patients who received brachytherapy and those who did not from 2000 onward (after the National Cancer Institute alert recommending concurrent chemotherapy). Results: Sixty-three percent of the 7359 women received brachytherapy in combinationmore » with EBRT, and 37% received EBRT alone. The brachytherapy utilization rate has decreased from 83% in 1988 to 58% in 2009 (P<.001), with a sharp decline of 23% in 2003 to 43%. Factors associated with higher odds of brachytherapy use include younger age, married (vs single) patients, earlier years of diagnosis, earlier stage and certain SEER regions. In the propensity score-matched cohort, brachytherapy treatment was associated with higher 4-year cause-specific survival (CSS; 64.3% vs 51.5%, P<.001) and overall survival (OS; 58.2% vs 46.2%, P<.001). Brachytherapy treatment was independently associated with better CSS (hazard ratio [HR], 0.64; 95% confidence interval [CI], 0.57-0.71), and OS (HR 0.66; 95% CI, 0.60 to 0.74). Conclusions: This population-based analysis reveals a concerning decline in brachytherapy utilization and significant geographic disparities in the delivery of brachytherapy in the United States. Brachytherapy use is independently associated with significantly higher CSS and OS and should be implemented in all feasible cases.« less

Spin cat state generation for quadrupolar nuclei in semiconductor quantum dots or defect centers

NASA Astrophysics Data System (ADS)

Bulutay, Ceyhun

Implementing spin-based quantum information encoding schemes in semiconductors has a high priority. The so-called cat codes offer a paradigm that enables hardware-efficient error correction. Their inauguration to semiconductor-based nuclear magnetic resonance framework hinges upon the realization of coherent spin states (CSS). In this work, we show how the crucial superpositions of CSS can be generated for the nuclear spins. This is through the intrinsic electric quadrupole interaction involving a critical role by the biaxiality term that is readily available, as in strained heterostructures of semiconductors, or defect centers having nearby quadrupolar spins. The persistence of the cat states is achieved using a rotation pulse so as to harness the underlying fixed points of the classical Hamiltonian. We classify the two distinct types as polar- and equator-bound over the Bloch sphere with respect to principal axes. Their optimal performance as well as sensitivity under numerous parameter deviations are analyzed. Finally, we present how these modulo-2 cat states can be extended to modulo-4 by a three-pulse scheme. This work was supported by TUBITAK, The Scientific and Technological Research Council of Turkey through the project No. 114F409.

Chronic social stress in pigs impairs intestinal barrier and nutrient transporter function, and alters neuro-immune mediator and receptor expression

PubMed Central

Li, Yihang; Song, Zehe; Kerr, Katelyn A.; Moeser, Adam J.

2017-01-01

Psychosocial stress is a major factor driving gastrointestinal (GI) pathophysiology and disease susceptibility in humans and animals. The mechanisms governing susceptibility to stress-induced GI disease remain poorly understood. In the present study, we investigated the influence of chronic social stress (CSS) in pigs, induced by 7 d of chronic mixing/crowding stress, on intestinal barrier and nutrient transport function, corticotropin releasing factor (CRF) signaling and immunological responses. Results from this study showed that CSS resulted in a significant impairment of ileal and colonic barrier function indicated by reduced transepithelial electrical resistance (TER) in the ileum and increased FD4 flux in the ileum (by 0.8 fold) and colon (by 0.7 fold). Ileal sodium glucose linked transporter 1 (SGLT-1) function, measured as glucose-induced changes in short-circuit current (Isc), was diminished (by 52%) in CSS pigs, associated with reduced body weight gain and feed efficiency. Although reductions in SGLT-1 function were observed in CSS pigs, mRNA expression for SGLT-1, villus heights were increased in CSS pigs. Corticotropin releasing factor (CRF) mRNA was upregulated (by 0.9 fold) in the ileum of CSS pigs but not in the colon. Urocortin 2 (Ucn2) mRNA was upregulated (by 1.5 fold) in the colon of CSS pigs, but not in the ileum. In CSS pigs, a downregulation of pro-inflammatory cytokines mRNA (IL1B, TNFA, IL8, and IL6) was observed in both ileum and colon, compared with controls. In contrast CSS induced a marked upregulation of mRNA for IL10 and mast cell chymase gene (CMA1) in the ileum and colon. Together, these data demonstrate that chronic stress in pigs results in significant alterations in intestinal barrier and nutrient transport function and neuro-immune mediator and receptor expression. PMID:28170426

Practice patterns of academic general thoracic and adult cardiac surgeons.

PubMed

Ingram, Michael T; Wisner, David H; Cooke, David T

2014-10-01

We hypothesized that academic adult cardiac surgeons (CSs) and general thoracic surgeons (GTSs) would have distinct practice patterns of, not just case-mix, but also time devoted to outpatient care, involvement in critical care, and work relative value unit (wRVU) generation for the procedures they perform. We queried the University Health System Consortium-Association of American Medical Colleges Faculty Practice Solution Center database for fiscal years 2007-2008, 2008-2009, and 2009-2010 for the frequency of inpatient and outpatient current procedural terminology coding and wRVU data of academic GTSs and CSs. The Faculty Practice Solution Center database is a compilation of productivity and payer data from 86 academic institutions. The greatest wRVU generating current procedural terminology codes for CSs were, in order, coronary artery bypass grafting, aortic valve replacement, and mitral valve replacement. In contrast, open lobectomy, video-assisted thoracic surgery wedge, and video-assisted thoracic surgery lobectomy were greatest for GTSs. The 10 greatest wRVU-generating procedures for CSs generated more wRVUs than those for GTSs (P<.001). Although CSs generated significantly more hospital inpatient evaluation and management (E & M) wRVUs than did GTSs (P<.001), only 2.5% of the total wRVUs generated by CSs were from E & M codes versus 18.8% for GTSs. Critical care codes were 1.5% of total evaluation and management billing for both CSs and GTSs. Academic CSs and GTSs have distinct practice patterns. CSs receive greater reimbursement for services because of the greater wRVUs of the procedures performed compared with GTSs, and evaluation and management coding is a more important wRVU generator for GTSs. The results of our study could guide academic CS and GTS practice structure and time prioritization. Copyright © 2014 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Absolute cross-sections for DNA strand breaks and crosslinks induced by low energy electrons

PubMed Central

Chen, Wenzhuang; Chen, Shiliang; Dong, Yanfang; Cloutier, Pierre; Sanche, Léon

2016-01-01

Absolute cross sections (CSs) for the interaction of low energy electrons with condensed macromolecules are essential parameters to accurately model ionizing radiation induced reactions. To determine CSs for various conformational DNA damage induced by 2–20 eV electrons, we investigated the influence of the attenuation length (AL) and penetration factor (f) using a mathematical model. Solid films of super-coiled plasmid DNA with thicknesses of 10, 15 and 20 nm were irradiated with 4.6, 5.6, 9.6 and 14.6 eV electrons. DNA conformational changes were quantified by gel electrophoresis, and the respective yields were extrapolated from exposure–response curves. The absolute CS, AL and f values were generated by applying the model developed by Rezaee et al. The values of AL were found to lie between 11 and 16 nm with the maximum at 14.6 eV. The absolute CSs for the loss of the supercoiled (LS) configuration and production of crosslinks (CL), single strand breaks (SSB) and double strand breaks (DSB) induced by 4.6, 5.6, 9.6 and 14.6 eV electrons are obtained. The CSs for SSB are smaller, but similar to those for LS, indicating that SSB are the main conformational damage. The CSs for DSB and CL are about one order of magnitude smaller than those of LS and SSB. The value of f is found to be independent of electron energy, which allows extending the absolute CSs for these types of damage within the range 2–20 eV, from previous measurements of effective CSs. When comparison is possible, the absolute CSs are found to be in good agreement with those obtained from previous similar studies with double-stranded DNA. The high values of the absolute CSs of 4.6 and 9.6 eV provide quantitative evidence for the high efficiency of low energy electrons to induce DNA damage via the formation of transient anions. PMID:27878170

Absolute cross-sections for DNA strand breaks and crosslinks induced by low energy electrons.

PubMed

Chen, Wenzhuang; Chen, Shiliang; Dong, Yanfang; Cloutier, Pierre; Zheng, Yi; Sanche, Léon

2016-12-07

Absolute cross sections (CSs) for the interaction of low energy electrons with condensed macromolecules are essential parameters to accurately model ionizing radiation induced reactions. To determine CSs for various conformational DNA damage induced by 2-20 eV electrons, we investigated the influence of the attenuation length (AL) and penetration factor (f) using a mathematical model. Solid films of supercoiled plasmid DNA with thicknesses of 10, 15 and 20 nm were irradiated with 4.6, 5.6, 9.6 and 14.6 eV electrons. DNA conformational changes were quantified by gel electrophoresis, and the respective yields were extrapolated from exposure-response curves. The absolute CS, AL and f values were generated by applying the model developed by Rezaee et al. The values of AL were found to lie between 11 and 16 nm with the maximum at 14.6 eV. The absolute CSs for the loss of the supercoiled (LS) configuration and production of crosslinks (CL), single strand breaks (SSB) and double strand breaks (DSB) induced by 4.6, 5.6, 9.6 and 14.6 eV electrons are obtained. The CSs for SSB are smaller, but similar to those for LS, indicating that SSB are the main conformational damage. The CSs for DSB and CL are about one order of magnitude smaller than those of LS and SSB. The value of f is found to be independent of electron energy, which allows extending the absolute CSs for these types of damage within the range 2-20 eV, from previous measurements of effective CSs. When comparison is possible, the absolute CSs are found to be in good agreement with those obtained from previous similar studies with double-stranded DNA. The high values of the absolute CSs of 4.6 and 9.6 eV provide quantitative evidence for the high efficiency of low energy electrons to induce DNA damage via the formation of transient anions.

Relationship of CYP2D6, CYP3A, POR, and ABCB1 genotypes with galantamine plasma concentrations.

PubMed

Noetzli, Muriel; Guidi, Monia; Ebbing, Karsten; Eyer, Stephan; Zumbach, Serge; Giannakopoulos, Panteleimon; von Gunten, Armin; Csajka, Chantal; Eap, Chin B

2013-04-01

The frequently prescribed antidementia drug galantamine is extensively metabolized by the enzymes cytochrome P450 (CYP) 2D6 and CYP3A and is a substrate of the P-glycoprotein. We aimed to study the relationship between genetic variants influencing the activity of these enzymes and transporters with galantamine steady state plasma concentrations. In this naturalistic cross-sectional study, 27 older patients treated with galantamine were included. The patients were genotyped for common polymorphisms in CYP2D6, CYP3A4/5, POR, and ABCB1, and galantamine steady state plasma concentrations were determined. The CYP2D6 genotype seemed to be an important determinant of galantamine pharmacokinetics, with CYP2D6 poor metabolizers presenting 45% and 61% higher dose-adjusted galantamine plasma concentrations than heterozygous and homozygous CYP2D6 extensive metabolizers (median 2.9 versus 2.0 ng/mL · mg, P = 0.025, and 1.8 ng/mL · mg, P = 0.004), respectively. The CYP2D6 genotype significantly influenced galantamine plasma concentrations. The influence of CYP2D6 polymorphisms on the treatment efficacy and tolerability should be further investigated.

Evaluation of an exposure setup for studying effects of diesel exhaust in humans.

PubMed

Rudell, B; Sandström, T; Hammarström, U; Ledin, M L; Hörstedt, P; Stjernberg, N

1994-01-01

Diesel exhaust is a common air pollutant and work exposure has been reported to cause discomfort and affect lung function. The aim of this study was to develop an experimental setup which would allow investigation of acute effects on symptoms and lung function in humans exposed to diluted diesel exhaust. Diluted diesel exhaust was fed from an idling lorry through heated tubes into an exposure chamber. During evaluations of the setup we found the size and the shape of the exhaust particles to appear unchanged during the transport from the tail pipe to the exposure chamber. The composition of the diesel exhaust expressed as the ratios CO/NO, total hydrocarbons/NO, particles/NO, NO2/NO, and formaldehyde/NO were almost constant at different dilutions. The concentrations of NO2 and particles in the exposure chamber showed no obvious gradients. New steady state concentrations in the exposure chamber were obtained within 5-7 min. In a separate experiment eight healthy nonsmoking subjects were exposed to diluted exhaust at a median steady state concentration of 1.6 ppm NO2 for the duration of 1 h in the exposure chamber. All subjects experienced unpleasant smell, eye irritation, and nasal irritation. Throat irritation, headache, dizziness, nausea, tiredness, and coughing were experienced by some subjects. Lung function was not found to be affected during the exposure. The experimental setup was found to be appropriate for creating different predetermined steady state concentrations in the exposure chamber of diluted exhaust from a continuously idling vehicle. The acute symptoms reported by the subjects were relatively similar to what patients reported at different workplaces.

Rivastigmine blocks voltage-activated K+ currents in dissociated rat hippocampal neurons

PubMed Central

Pan, Yaping; Xu, Xianghua; Wang, Xiaoliang

2003-01-01

Rivastigmine is an acetylcholinesterase inhibitor used in Alzheimer's disease therapy. In the present study, we investigated the effects of rivastigmine on the transient outward K+ current (IK(A)) and the delayed rectifier K+ current (IK(DR)) in acutely dissociated rat hippocampal pyramidal neurons using the whole-cell patch-clamp technique. Rivastigmine inhibited the amplitudes of IK(A) and IK(DR) in a reversible and concentration-dependent manner. At a concentration of 100 μM, rivastigmine inhibited IK(A) and IK(DR), recorded when the cells were depolarized from −50 to +40 mV, by 65.9 (P<0.01) and 67.3% (P<0.01), respectively. The IC50 values for IK(A) and IK(DR) were 3.8 and 1.7 μM, respectively. The decay time constant of IK(A), recorded following a test pulse to +40 mV, was prolonged reversibly by rivastigmine at concentrations of 10 and 100 μM (both P<0.05). Rivastigmine affected the voltage dependence of IK(A) and IK(DR). At a concentration of 10 μM, it shifted the steady-state inactivation curve of IK(A) towards more negative potentials by −11 mV (P<0.05), but had no effect on the steady-state activation curve or the recovery from inactivation. Regarding the kinetic properties of IK(DR), 10 μM rivastigmine shifted the steady-state activation and inactivation curves towards more negative potentials by −10 (P<0.05) and −27 mV (P<0.01), respectively. Our findings that rivastigmine inhibits IK(A) and IK(DR) in rat hippocampal pyramidal neurons suggest that this agent has other pharmacological actions besides its antiacetylcholinesterase activity. PMID:14504131

The pharmacokinetics of colistin in patients with cystic fibrosis.

PubMed

Reed, M D; Stern, R C; O'Riordan, M A; Blumer, J L

2001-06-01

The safety and pharmacokinetics of colistin were determined after first dose (n = 30) and again under steady-state conditions (n = 27) in 31 patients with cystic fibrosis receiving the drug as a component of their treatment for an acute pulmonary exacerbation of their disease. Patients ranged in age from 14 to 53 years and received colistin for 6 to 35 days. Each patient was started on colistin 5 to 7 mg/kg/day administered intravenously in three equally divided doses. Elimination half-life (t1/2), mean residence time (MRT), steady-state volume of distribution (Vdss), total body clearance (Cl), and renal clearance (Clr) after first-dose administration averaged 3.4 hours, 4.4 hours, 0.09 l/kg, and 0.35 and 0.24 ml/min/kg, respectively. No differences in colistin disposition characteristics between first-dose and steady-state evaluations were observed. Sputum sampling was incomplete and confounded by previous aerosol administration but revealed colistin concentrations that markedly exceeded observed plasma concentrations. Twenty-one patients experienced one or more side effects attributed to colistin administration. The most common reactions involved reversible neurologic manifestations, including oral and perioral paresthesias (n = 16), headache (n = 5), and lower limb weakness (n = 5). All of these apparent colistin-induced neurologic adverse effects, though bothersome, were benign and reversible. Intermittent proteinuria was observed on urinalysis in 14 patients, and 1 patient developed reversible, colistin-induced nephrotoxicity. No relationship between the occurrence of any colistin-associated adverse effect and plasma colistin concentration or colistin pharmacokinetic parameter estimate was observed. These data provide no basis for routine monitoring of colistin plasma concentrations to guide dosing for patient safety and suggest slow upward dose titration to minimize the incidence and severity of associated side effects.

Calcium distribution in Amoeba proteus

PubMed Central

1979-01-01

A preliminary investigation of the distribution of cellular calcium in Amoeba proteus was undertaken. Total cellular calcium under control conditions was found to be 4.59 mmol/kg of cells. When the external Ca++ concentration is increased from the control level of 0.03 to 20 mM, a net Ca++ influx results with a new steady-state cellular calcium level being achieved in integral of 3 h. At steady state the amount of calcium per unit weight of cells is higher than the amount of calcium per unit weight of external solution when the external concentration of Ca++ is below 10 mM. At external Ca++ concentrations above this level, total cellular calcium approaches the medium level of Ca++. Steady- state calcium exchange in Amoeba proteus was determined with 45Ca. There is an immediate and rapid exchange of integral of 0.84 mmol/kg of cells or 18% of the total cellular calcium with the labelled Ca++. Following this initial exchange, there was very little if any further exchange observed. Most of this exchanged calcium could be eliminated from the cell with 1 mM La+++, suggesting that the exchanged calcium is associated with the surface of the cell. Increase in either the external Ca++ concentration of pH raise the amount of exchangeable calcium associated with the cell. Calcium may be associated with the cell surface as a co-ion in the diffuse double layer or bound to fixed negative sites on the surface of the cell. If Ca++-binding sites do exist on the cell surface, there may be more than one type and they may have different dissociation constants. The cytoplasmic Ca++ ion activity is probably maintained at very low levels. PMID:512628

Mean field model of acetylcholine mediated dynamics in the cerebral cortex.

PubMed

Clearwater, J M; Rennie, C J; Robinson, P A

2007-12-01

A recent continuum model of the large scale electrical activity of the cerebral cortex is generalized to include cholinergic modulation. In this model, dynamic modulation of synaptic strength acts over the time scales of nicotinic and muscarinic receptor action. The cortical model is analyzed to determine the effect of acetylcholine (ACh) on its steady states, linear stability, spectrum, and temporal responses to changes in subcortical input. ACh increases the firing rate in steady states of the system. Changing ACh concentration does not introduce oscillatory behavior into the system, but increases the overall spectral power. Model responses to pulses in subcortical input are affected by the tonic level of ACh concentration, with higher levels of ACh increasing the magnitude firing rate response of excitatory cortical neurons to pulses of subcortical input. Numerical simulations are used to explore the temporal dynamics of the model in response to changes in ACh concentration. Evidence is seen of a transition from a state in which intracortical inputs are emphasized to a state where thalamic afferents have enhanced influence. Perturbations in ACh concentration cause changes in the firing rate of cortical neurons, with rapid responses due to fast acting facilitatory effects of nicotinic receptors on subcortical afferents, and slower responses due to muscarinic suppression of intracortical connections. Together, these numerical simulations demonstrate that the actions of ACh could be a significant factor modulating early components of evoked response potentials.

32 CFR 299.2 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... INFORMATION ACT PROGRAM NATIONAL SECURITY AGENCY/CENTRAL SECURITY SERVICE (NSA/CSS) FREEDOM OF INFORMATION ACT... request. (1) A written request for NSA/CSS records, that reasonably describes the records sought, made by... implicitly invokes 5 U.S.C. 552, as amended, 5 U.S.C. 552a, as amended, DoD 5400.7-R, or NSA/CSS Freedom of...

32 CFR 299.2 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... INFORMATION ACT PROGRAM NATIONAL SECURITY AGENCY/CENTRAL SECURITY SERVICE (NSA/CSS) FREEDOM OF INFORMATION ACT... request. (1) A written request for NSA/CSS records, that reasonably describes the records sought, made by... implicitly invokes 5 U.S.C. 552, as amended, 5 U.S.C. 552a, as amended, DoD 5400.7-R, or NSA/CSS Freedom of...

32 CFR 299.2 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... INFORMATION ACT PROGRAM NATIONAL SECURITY AGENCY/CENTRAL SECURITY SERVICE (NSA/CSS) FREEDOM OF INFORMATION ACT... request. (1) A written request for NSA/CSS records, that reasonably describes the records sought, made by... implicitly invokes 5 U.S.C. 552, as amended, 5 U.S.C. 552a, as amended, DoD 5400.7-R, or NSA/CSS Freedom of...

Development and Validation of an Instrument for Assessing Climate Change Knowledge and Perceptions: The Climate Stewardship Survey (CSS)

ERIC Educational Resources Information Center

Walker, Scott L.; McNeal, Karen S.

2013-01-01

The Climate Stewardship Survey (CSS) was developed to measure knowledge and perceptions of global climate change, while also considering information sources that respondents 'trust.' The CSS was drafted using a three-stage approach: development of salient scales, writing individual items, and field testing and analyses. Construct validity and…

Concurrent Validity of the Classroom Strategies Scale for Elementary School--Observer Form

ERIC Educational Resources Information Center

Reddy, Linda A.; Fabiano, Gregory A.; Dudek, Christopher M.

2013-01-01

The present study is an initial investigation of the concurrent validity of a new assessment, the Classroom Strategies Scale (CSS version 2.0) for Elementary School--Observer Form. The CSS assesses teachers' use of instructional and behavioral management strategies. In the present study, the CSS is compared to the Classroom Assessment Scoring…

A Multidose Study to Examine the Effect of Food on Evacetrapib Exposure at Steady State

PubMed Central

Zhang, Wei; Royalty, Jane; Cannady, Ellen A.; Downs, Delyn; Friedrich, Stuart; Suico, Jeffrey G.

2015-01-01

Purpose: To determine the effect of a high-fat meal on evacetrapib exposure at steady state in healthy participants. Methods: This was a randomized, 2-period, 2-sequence, open-label, crossover study. Patients were randomly assigned to 1 of the 2 treatment sequences in which they received evacetrapib 130 mg/d for 10 days following a 10-hour fast each day or following a high-fat breakfast each day. Plasma samples collected through 24 hours were analyzed for evacetrapib concentrations and pharmacokinetic parameter estimates including area under the concentration–time curve during a dosing interval (AUCτ), maximum observed concentration (Cmax), and time of Cmax (tmax) were calculated. Pharmacodynamic parameters, including cholesteryl ester transfer protein (CETP) activity, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol, and triglycerides, were also assessed. Results: A total of 34 males and 6 females, mean age 41.5 years and mean body mass index 26.6 kg/m2, were enrolled. Statistical analysis showed AUCτ was 44% higher (90% confidence interval [CI]: 29%-62%) and Cmax was 51% higher (90% CI: 28%-79%) in the fed state than in the fasted state, indicating an effect of food. Consistent with higher evacetrapib exposure, changes in HDL-C, LDL-C, and CETP activity appeared to be greater in the fed state than in the fasted state. There were no notable changes in total cholesterol or triglycerides following administration in the fed and fasted states. The 130-mg doses of evacetrapib were well tolerated with and without food. Conclusion: A high-fat meal increased evacetrapib mean exposure at steady state by 44% in healthy participants. PMID:25736283

Iron and Sulfur Species and Sulfur Isotopic Compositions of Authigenic Pyrite in Gas Hydrate-Bearing Sediments from Hydrate Ridge, Cascadia Margin (ODP Leg 204): A Proposal of Conceptual Models to Indicate the Non-Steady State Depositional and Diagenetic Processes

NASA Astrophysics Data System (ADS)

Liu, C.; Jiang, S. Y.; Su, X.

2017-12-01

Two accretionary sediment sequences from Sites 1245 and 1252 recovered during Ocean Drilling Program (ODP) Leg 204 at Hydrate Ridge, Cascadia Margin were investigated to explore the non-steady state depositional and diagenetic history. Five iron species and three sulfur species were chemically extracted, and their concentrations and the sulfur isotopic compositions of pyrite were determined. After the mineral recognitions of these species and detailed comparative analyses, the aerobic history of bottom seawater has been determined. The formation of pyrite is thought to be controlled by the limited production of hydrogen sulfide relative to the supply of reactive iron. Also, the intrusion of oxygen by bioturbation would oxidize the reduced sulfur species and further suppress pyritization. To explain the geochemical relationship between pyrite and siderite and the sulfur isotope characteristics of pyrite, we propose seven conceptual models based on the variations in depositional rate and methane flux, and the models succeed in explaining the geochemical results and are validated by the observed non-steady state events. These models may contribute to the reconstruction of the non-steady state processes in other research areas in the future.

New steady-state quiescent high-confinement plasma in an experimental advanced superconducting tokamak.

PubMed

Hu, J S; Sun, Z; Guo, H Y; Li, J G; Wan, B N; Wang, H Q; Ding, S Y; Xu, G S; Liang, Y F; Mansfield, D K; Maingi, R; Zou, X L; Wang, L; Ren, J; Zuo, G Z; Zhang, L; Duan, Y M; Shi, T H; Hu, L Q

2015-02-06

A critical challenge facing the basic long-pulse high-confinement operation scenario (H mode) for ITER is to control a magnetohydrodynamic (MHD) instability, known as the edge localized mode (ELM), which leads to cyclical high peak heat and particle fluxes at the plasma facing components. A breakthrough is made in the Experimental Advanced Superconducting Tokamak in achieving a new steady-state H mode without the presence of ELMs for a duration exceeding hundreds of energy confinement times, by using a novel technique of continuous real-time injection of a lithium (Li) aerosol into the edge plasma. The steady-state ELM-free H mode is accompanied by a strong edge coherent MHD mode (ECM) at a frequency of 35-40 kHz with a poloidal wavelength of 10.2 cm in the ion diamagnetic drift direction, providing continuous heat and particle exhaust, thus preventing the transient heat deposition on plasma facing components and impurity accumulation in the confined plasma. It is truly remarkable that Li injection appears to promote the growth of the ECM, owing to the increase in Li concentration and hence collisionality at the edge, as predicted by GYRO simulations. This new steady-state ELM-free H-mode regime, enabled by real-time Li injection, may open a new avenue for next-step fusion development.

Regulation of Vacuolar H+-ATPase (V-ATPase) Reassembly by Glycolysis Flow in 6-Phosphofructo-1-kinase (PFK-1)-deficient Yeast Cells*

PubMed Central

Chan, Chun-Yuan; Dominguez, Dennis; Parra, Karlett J.

2016-01-01

Yeast 6-phosphofructo-1-kinase (PFK-1) has two subunits, Pfk1p and Pfk2p. Deletion of Pfk2p alters glucose-dependent V-ATPase reassembly and vacuolar acidification (Chan, C. Y., and Parra, K. J. (2014) Yeast phosphofructokinase-1 subunit Pfk2p is necessary for pH homeostasis and glucose-dependent vacuolar ATPase reassembly. J. Biol. Chem. 289, 19448–19457). This study capitalized on the mechanisms suppressing vacuolar H+-ATPase (V-ATPase) in pfk2Δ to gain new knowledge of the mechanisms underlying glucose-dependent V-ATPase regulation. Because V-ATPase is fully assembled in pfk2Δ, and glycolysis partially suppressed at steady state, we manipulated glycolysis and assessed its direct involvement on V-ATPase function. At steady state, the ratio of proton transport to ATP hydrolysis increased 24% after increasing the glucose concentration from 2% to 4% to enhance the glycolysis flow in pfk2Δ. Tighter coupling restored vacuolar pH when glucose was abundant and glycolysis operated below capacity. After readdition of glucose to glucose-deprived cells, glucose-dependent V1Vo reassembly was proportional to the glycolysis flow. Readdition of 2% glucose to pfk2Δ cells, which restored 62% of ethanol concentration, led to equivalent 60% V1Vo reassembly levels. Steady-state level of assembly (100% reassembly) was reached at 4% glucose when glycolysis reached a threshold in pfk2Δ (≥40% the wild-type flow). At 4% glucose, the level of Pfk1p co-immunoprecipitated with V-ATPase decreased 58% in pfk2Δ, suggesting that Pfk1p binding to V-ATPase may be inhibitory in the mutant. We concluded that V-ATPase activity at steady state and V-ATPase reassembly after readdition of glucose to glucose-deprived cells are controlled by the glycolysis flow. We propose a new mechanism by which glucose regulates V-ATPase catalytic activity that occurs at steady state without changing V1Vo assembly. PMID:27226568

Diagnosis and management of traumatic cervical central spinal cord injury: A review.

PubMed

Epstein, Nancy E; Hollingsworth, Renee

2015-01-01

The classical clinical presentation, neuroradiographic features, and conservative vs. surgical management of traumatic cervical central spinal cord (CSS) injury remain controversial. CSS injuries, occurring in approximately 9.2% of all cord injuries, are usually attributed to significant hyperextension trauma combined with congenital/acquired cervical stenosis/spondylosis. Patients typically present with greater motor deficits in the upper vs. lower extremities accompanied by patchy sensory loss. T2-weighted magnetic resonance (MR) scans usually show hyperintense T2 intramedullary signals reflecting acute edema along with ligamentous injury, while noncontrast computed tomography (CT) studies typically show no attendant bony pathology (e.g. no fracture, dislocation). CSS constitute only a small percentage of all traumatic spinal cord injuries. Aarabi et al. found CSS patients averaged 58.3 years of age, 83% were male and 52.4% involved accidents/falls in patients with narrowed spinal canals (average 5.6 mm); their average American Spinal Injury Association (ASIA) motor score was 63.8, and most pathology was at the C3-C4 and C4-C5 levels (71%). Surgery was performed within 24 h (9 patients), 24-48 h (10 patients), or after 48 h (23 patients). In the Brodell et al. study of 16,134 patients with CSS, 39.7% had surgery. In the Gu et al. series, those with CSS and stenosis/ossification of the posterior longitudinal ligament (OPLL) exhibited better outcomes following laminoplasty. Recognizing the unique features of CSS is critical, as the clinical, neuroradiological, and management strategies (e.g. conservative vs. surgical management: early vs. late) differ from those utilized for other spinal cord trauma. Increased T2-weighted MR images best document CSS, while CT studies confirm the absence of fracture/dislocation.

Generation of human secondary cardiospheres as a potent cell processing strategy for cell-based cardiac repair.

PubMed

Cho, Hyun-Jai; Lee, Ho-Jae; Chung, Yeon-Ju; Kim, Ju-Young; Cho, Hyun-Ju; Yang, Han-Mo; Kwon, Yoo-Wook; Lee, Hae-Young; Oh, Byung-Hee; Park, Young-Bae; Kim, Hyo-Soo

2013-01-01

Cell therapy is a promising approach for repairing damaged heart. However, there are large rooms to be improved in therapeutic efficacy. We cultured a small quantity (5-10 mg) of heart biopsy tissues from 16 patients who received heart transplantation. We produced primary and secondary cardiospheres (CSs) using repeated three-dimensional culture strategy and characterized the cells. Approximately 5000 secondary CSs were acquired after 45 days. Genetic analysis confirmed that the progenitor cells in the secondary CSs originated from the innate heart, but not from extra-cardiac organs. The expressions of Oct4 and Nanog were significantly induced in secondary CSs compared with adherent cells derived from primary CSs. Those expressions in secondary CSs were higher in a cytokine-deprived medium than in a cytokine-supplemented one, suggesting that formation of the three-dimensional structure was important to enhance stemness whereas supplementation with various cytokines was not essential. Signal blocking experiments showed that the ERK and VEGF pathways are indispensable for sphere formation. To optimize cell processing, we compared four different methods of generating spheres. Method based on the hanging-drop or AggreWell™ was superior to that based on the poly-d-lysine-coated dish or Petri dish with respect to homogeneity of the product, cellular potency and overall simplicity of the process. When transplanted into the ischemic myocardium of immunocompromised mice, human secondary CSs differentiated into cardiomyocytes and endothelial cells. These results demonstrate that generation of secondary CSs from a small quantity of adult human cardiac tissue is a feasible and effective cell processing strategy to improve the therapeutic efficacy of cell therapy. Copyright © 2012 Elsevier Ltd. All rights reserved.

Oligodendrocyte gene expression is reduced by and influences effects of chronic social stress in mice.

PubMed

Cathomas, F; Azzinnari, D; Bergamini, G; Sigrist, H; Buerge, M; Hoop, V; Wicki, B; Goetze, L; Soares, S; Kukelova, D; Seifritz, E; Goebbels, S; Nave, K-A; Ghandour, M S; Seoighe, C; Hildebrandt, T; Leparc, G; Klein, H; Stupka, E; Hengerer, B; Pryce, C R

2018-03-22

Oligodendrocyte gene expression is downregulated in stress-related neuropsychiatric disorders, including depression. In mice, chronic social stress (CSS) leads to depression-relevant changes in brain and emotional behavior, and the present study shows the involvement of oligodendrocytes in this model. In C57BL/6 (BL/6) mice, RNA-sequencing (RNA-Seq) was conducted with prefrontal cortex, amygdala and hippocampus from CSS and controls; a gene enrichment database for neurons, astrocytes and oligodendrocytes was used to identify cell origin of deregulated genes, and cell deconvolution was applied. To assess the potential causal contribution of reduced oligodendrocyte gene expression to CSS effects, mice heterozygous for the oligodendrocyte gene cyclic nucleotide phosphodiesterase (Cnp1) on a BL/6 background were studied; a 2 genotype (wildtype, Cnp1 +/- ) × 2 environment (control, CSS) design was used to investigate effects on emotional behavior and amygdala microglia. In BL/6 mice, in prefrontal cortex and amygdala tissue comprising gray and white matter, CSS downregulated expression of multiple oligodendroycte genes encoding myelin and myelin-axon-integrity proteins, and cell deconvolution identified a lower proportion of oligodendrocytes in amygdala. Quantification of oligodendrocyte proteins in amygdala gray matter did not yield evidence for reduced translation, suggesting that CSS impacts primarily on white matter oligodendrocytes or the myelin transcriptome. In Cnp1 mice, social interaction was reduced by CSS in Cnp1 +/- mice specifically; using ionized calcium-binding adaptor molecule 1 (IBA1) expression, microglia activity was increased additively by Cnp1 +/- and CSS in amygdala gray and white matter. This study provides back-translational evidence that oligodendrocyte changes are relevant to the pathophysiology and potentially the treatment of stress-related neuropsychiatric disorders. © 2018 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

OSCILLATION OF CURRENT SHEETS IN THE WAKE OF A FLUX ROPE ERUPTION OBSERVED BY THE SOLAR DYNAMICS OBSERVATORY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, L. P.; Zhang, J.; Su, J. T.

An erupting flux rope (FR) draws its overlying coronal loops upward, causing a coronal mass ejection. The legs of the overlying loops with opposite polarities are driven together. Current sheets (CSs) form, and magnetic reconnection, producing underneath flare arcades, occurs in the CSs. Employing Solar Dynamic Observatory /Atmospheric Imaging Assembly images, we study a FR eruption on 2015 April 23, and for the first time report the oscillation of CSs underneath the erupting FR. The FR is observed in all AIA extreme-ultraviolet passbands, indicating that it has both hot and warm components. Several bright CSs, connecting the erupting FR andmore » the underneath flare arcades, are observed only in hotter AIA channels, e.g., 131 and 94 Å. Using the differential emission measure (EM) analysis, we find that both the temperature and the EM of CSs temporally increase rapidly, reach the peaks, and then decrease slowly. A significant delay between the increases of the temperature and the EM is detected. The temperature, EM, and density spatially decrease along the CSs with increasing heights. For a well-developed CS, the temperature (EM) decreases from 9.6 MK (8 × 10{sup 28} cm{sup −5}) to 6.2 MK (5 × 10{sup 27} cm{sup −5}) in 52 Mm. Along the CSs, dark supra-arcade downflows (SADs) are observed, and one of them separates a CS into two. While flowing sunward, the speeds of the SADs decrease. The CSs oscillate with a period of 11 minutes, an amplitude of 1.5 Mm, and a phase speed of 200 ± 30 km s{sup −1}. One of the oscillations lasts for more than 2 hr. These oscillations represent fast-propagating magnetoacoustic kink waves.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roach, Mack, E-mail: mroach@radonc.ucsf.edu; Ceron Lizarraga, Tania L.; Lazar, Ann A.

Purpose: The optimal treatment of clinically localized prostate cancer is controversial. Most studies focus on biochemical (PSA) failure when comparing radical prostatectomy (RP) with radiation therapy (RT), but this endpoint has not been validated as predictive of overall survival (OS) or cause-specific survival (CSS). We analyzed the available literature to determine whether reliable conclusions could be made concerning the effectiveness of RP compared with RT with or without androgen deprivation therapy (ADT), assuming current treatment standards. Methods: Articles published between February 29, 2004, and March 1, 2015, that compared OS and CSS after RP or RT with or without ADTmore » were included. Because the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) system emphasis is on randomized controlled clinical trials, a reliability score (RS) was explored to further understand the issues associated with the study quality of observational studies, including appropriateness of treatment, source of data, clinical characteristics, and comorbidity. Lower RS values indicated lower reliability. Results: Fourteen studies were identified, and 13 were completely evaluable. Thirteen of the 14 studies (93%) were observational studies with low-quality evidence. The median RS was 12 (range, 5-18); the median difference in 10-year OS and CSS favored RP over RT: 10% and 4%, respectively. In studies with a RS ≤12 (average RS 9) the 10-year OS and CSS median differences were 17% and 6%, respectively. For studies with a RS >12 (average RS 15.5), the 10-year OS and CSS median differences were 5.5% and 1%, respectively. Thus, we observed an association between low RS and a higher percentage difference in OS and CSS. Conclusions: Reliable evidence that RP provides a superior CSS to RT with ADT is lacking. The most reliable studies suggest that the differences in 10-year CSS between RP and RT are small, possibly <1%.« less

Extended-Release Once-Daily Formulation of Tofacitinib: Evaluation of Pharmacokinetics Compared With Immediate-Release Tofacitinib and Impact of Food.

PubMed

Lamba, Manisha; Wang, Rong; Fletcher, Tracey; Alvey, Christine; Kushner, Joseph; Stock, Thomas C

2016-11-01

Tofacitinib is an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis. An extended-release (XR) formulation has been designed to provide a once-daily (QD) dosing option to patients to achieve comparable pharmacokinetic (PK) parameters to the twice-daily immediate-release (IR) formulation. We conducted 2 randomized, open-label, phase 1 studies in healthy volunteers. Study A characterized single-dose and steady-state PK of tofacitinib XR 11 mg QD and intended to demonstrate equivalence of exposure under single-dose and steady-state conditions to tofacitinib IR 5 mg twice daily. Study B assessed the effect of a high-fat meal on the bioavailability of tofacitinib from the XR formulation. Safety and tolerability were monitored in both studies. In study A (N = 24), the XR and IR formulations achieved time to maximum plasma concentration at 4 hours and 0.5 hours postdose, respectively; terminal half-life was 5.9 hours and 3.2 hours, respectively. Area under plasma concentration-time curve (AUC) and maximum plasma concentration (C max ) after single- and multiple-dose administration were equivalent between the XR and IR formulations. In study B (N = 24), no difference in AUC was observed for fed vs fasted conditions. C max increased by 27% under the fed state. On repeat administration, negligible accumulation (<20%) of systemic exposures was observed for both formulations. Steady state was achieved within 48 hours of dosing with the XR formulation. Tofacitinib administration as an XR or IR formulation was generally well tolerated in these studies. © 2016, The Authors. The Journal of Clinical Pharmacology published by Wiley Periodicals, Inc. on behalf of American College of Clinical Pharmacology.

Observations and light curve solutions of a selection of shallow-contact W UMa binaries

NASA Astrophysics Data System (ADS)

Kjurkchieva, Diana P.; Popov, Velimir A.; Vasileva, Doroteya L.; Petrov, Nikola I.

2018-07-01

Photometric observations in Sloan g‧ and i‧ bands of the W UMa binaries V0951 Per, CSS J062803.2+571604, CSS J222157.2+275308, CSS J075135.6+382028, V0338 Dra, NSVS 2256852, NSVS 4666412, V1355 Tau, NSVS 4808227, NSVS 4726498, CSS J075350.1+264830 and HL Lyn are presented. The light curve solutions revealed that these binaries have overcontact configurations with small fillout factors (within 0.1-0.2). Seven of them undergo total eclipses and their photometric mass ratios should be accepted with confidence. The temperature differences of the components of CSS J062803.2+571604 and NSVS 2256852 exceed 1100 K which is unusual for overcontact binaries. We suspect that NSVS 2256852 is a probable candidate for merger due to its small mass ratio of q = 0.16 and to the registered decreasing of the orbital period.

Tribological properties of graphene oxide and carbon spheres as lubricating additives

NASA Astrophysics Data System (ADS)

Song, Haojie; Wang, Zhiqiang; Yang, Jin

2016-10-01

The purpose of this paper was to investigate the tribological properties of carbon materials with various morphologies [i.e., graphene oxide (GO) and carbon spheres (CSs)] utilized as lubricating additives on a ball-plate tribotester. The morphology and spectroscopy characterization of GO and CSs were investigated by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectrometry, and thermogravimetric analysis. Friction and wear properties of the sunflower seed oil filled with GO and CSs were investigated by using a MS-T3000 ball-on-disk apparatus. Results show that the sunflower seed oil containing 0.3 wt% GO nanosheets exhibited a substantial diminution in friction and wear compared with the 3.0 wt% CSs as sunflower seed oil additives. Formation of low-shear strength tribofilms containing GO and its self-lubricating behavior was the key factor in reduction of the friction and prevention from wear and deformation. In addition, friction mechanism of CSs was also discussed.

Child Passenger Safety Technician Consultation in the Pediatric Primary Care Setting.

PubMed

Burstein, Dina; Zonfrillo, Mark R; Baird, Janette; Mello, Michael J

2017-09-01

Correct use of a child safety seat (CSS) can reduce the risk of fatal motor vehicle crash-related injury by up to 71%; however, misuse rates for CSS are as high as 70%. We recruited 189 caregivers at 2 large suburban pediatric office practices; 94 in the intervention group and 95 in the control group. All participants completed a baseline survey and received a CSS safety brochure. Intervention participants had their CSS installation checked at enrollment by a certified child passenger safety (CPS) technician. Follow-up was conducted 4 months post enrollment. Intervention group participants had a 21.3% reduction in critical misuse at follow-up, whereas control participants critical misuse rate at follow-up was identical to the intervention group at baseline. A consult with a certified CPS technician, at the time of a routine visit to the pediatrician, resulted in a reduction in CSS misuse rates.

Boundary Layer Model for Air Pollutant Concentrations Due to Highway Traffic

ERIC Educational Resources Information Center

Ragland, Kenneth W.; Peirce, J. Jeffrey

1975-01-01

A numerical solution of the three-dimensional steady-state diffusion equation for a finite width line source is presented. The wind speed and eddy diffusivity as a function of height above the roadway are obtained. Normalized ground level and elevated concentrations near a highway are obtained for winds perpendicular, parallel, and at 45 degrees.…

40 CFR 92.130 - Determination of steady-state concentrations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... concentration measurement, measured after 300 seconds (or 840 seconds for notch 8) of testing shall be used... seconds (or 840 seconds for notch 8) of testing shall be used. The provisions of paragraphs (b) through (f... seconds (or 900 seconds for notch 8) of measurement, and dividing the area by 360 seconds (or 900 seconds...

40 CFR 92.130 - Determination of steady-state concentrations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... concentration measurement, measured after 300 seconds (or 840 seconds for notch 8) of testing shall be used... seconds (or 840 seconds for notch 8) of testing shall be used. The provisions of paragraphs (b) through (f... seconds (or 900 seconds for notch 8) of measurement, and dividing the area by 360 seconds (or 900 seconds...

Computation of Steady-State Probability Distributions in Stochastic Models of Cellular Networks

PubMed Central

Hallen, Mark; Li, Bochong; Tanouchi, Yu; Tan, Cheemeng; West, Mike; You, Lingchong

2011-01-01

Cellular processes are “noisy”. In each cell, concentrations of molecules are subject to random fluctuations due to the small numbers of these molecules and to environmental perturbations. While noise varies with time, it is often measured at steady state, for example by flow cytometry. When interrogating aspects of a cellular network by such steady-state measurements of network components, a key need is to develop efficient methods to simulate and compute these distributions. We describe innovations in stochastic modeling coupled with approaches to this computational challenge: first, an approach to modeling intrinsic noise via solution of the chemical master equation, and second, a convolution technique to account for contributions of extrinsic noise. We show how these techniques can be combined in a streamlined procedure for evaluation of different sources of variability in a biochemical network. Evaluation and illustrations are given in analysis of two well-characterized synthetic gene circuits, as well as a signaling network underlying the mammalian cell cycle entry. PMID:22022252

Hydrodynamic Attraction of Swimming Microorganisms by Surfaces

NASA Astrophysics Data System (ADS)

Berke, Allison P.; Turner, Linda; Berg, Howard C.; Lauga, Eric

2008-07-01

Cells swimming in confined environments are attracted by surfaces. We measure the steady-state distribution of smooth-swimming bacteria (Escherichia coli) between two glass plates. In agreement with earlier studies, we find a strong increase of the cell concentration at the boundaries. We demonstrate theoretically that hydrodynamic interactions of the swimming cells with solid surfaces lead to their reorientation in the direction parallel to the surfaces, as well as their attraction by the closest wall. A model is derived for the steady-state distribution of swimming cells, which compares favorably with our measurements. We exploit our data to estimate the flagellar propulsive force in swimming E. coli.

[The accuracy of rapid equilibrium assumption in steady-state enzyme kinetics is the function of equilibrium segment structure and properties].

PubMed

Vrzheshch, P V

2015-01-01

Quantitative evaluation of the accuracy of the rapid equilibrium assumption in the steady-state enzyme kinetics was obtained for an arbitrary mechanism of an enzyme-catalyzed reaction. This evaluation depends only on the structure and properties of the equilibrium segment, but doesn't depend on the structure and properties of the rest (stationary part) of the kinetic scheme. The smaller the values of the edges leaving equilibrium segment in relation to values of the edges within the equilibrium segment, the higher the accuracy of determination of intermediate concentrations and reaction velocity in a case of the rapid equilibrium assumption.

EVALUATION OF VENTILATION PERFORMANCE FOR INDOOR SPACE

EPA Science Inventory

The paper discusses a personal-computer-based application of computational fluid dynamics that can be used to determine the turbulent flow field and time-dependent/steady-state contaminant concentration distributions within isothermal indoor space. (NOTE: Ventilation performance ...

Predicting Thermal Behavior of Secondary Organic Aerosols

EPA Science Inventory

Volume concentrations of steady-state secondary organic aerosol (SOA) were measured in 139 steadystate single precursor hydrocarbon oxidation experiments after passing through a temperature controlled inlet tube. Higher temperatures resulted in greater loss of particle volume, wi...

Pilocarpine disposition and salivary flow responses following intravenous administration to dogs.

PubMed

Weaver, M L; Tanzer, J M; Kramer, P A

1992-08-01

Oral doses of pilocarpine increase salivary flow rates in patients afflicted with xerostomia (dry mouth). This study examined the pharmacokinetics of and a pharmacodynamic response (salivation) to intravenous pilocarpine nitrate administration in dogs. Disposition was linear over a dose range of 225-600 micrograms/kg; plasma concentrations were 10-120 micrograms/L. Elimination was rapid and generally biphasic, with a terminal elimination half-life of approximately 1.3 hr. The systemic clearance of pilocarpine was high (2.22 +/- 0.49 L/kg/hr) and its steady-state volume of distribution (2.30 +/- 0.64 L/kg) was comparable to that of many other basic drugs. All doses of pilocarpine induced measurable submaxillary and parotid salivary flow rates which could be maintained constant over time. Cumulative submaxillary saliva flow was linearly related to total pilocarpine dose. Plasma pilocarpine concentration was linearly related to both steady-state and postinfusion submaxillary salivary flow rates.

Computational modelling of cellular level metabolism

NASA Astrophysics Data System (ADS)

Calvetti, D.; Heino, J.; Somersalo, E.

2008-07-01

The steady and stationary state inverse problems consist of estimating the reaction and transport fluxes, blood concentrations and possibly the rates of change of some of the concentrations based on data which are often scarce noisy and sampled over a population. The Bayesian framework provides a natural setting for the solution of this inverse problem, because a priori knowledge about the system itself and the unknown reaction fluxes and transport rates can compensate for the insufficiency of measured data, provided that the computational costs do not become prohibitive. This article identifies the computational challenges which have to be met when analyzing the steady and stationary states of multicompartment model for cellular metabolism and suggest stable and efficient ways to handle the computations. The outline of a computational tool based on the Bayesian paradigm for the simulation and analysis of complex cellular metabolic systems is also presented.

Deceptive Logistics at the Operational Level of War,

DTIC Science & Technology

1987-05-04

maintenance, transport , and other combat service support (CSS) activities with the distinct purpose of contributing to an operational headquarters’ overall...based on the exploitation of supply, maintenance, transport , and other combat service support (CSS) activities with the distinct purpose of contributing...exploitation of supply, maintenance, transport , and other CSS activities with the distinct purpose of contributing to an operational headquarters overall

Exploring the Oral Communication Strategies Used by Turkish EFL Learners: A Mixed Methods Study

ERIC Educational Resources Information Center

Demir, Yusuf; Mutlu, Gülçin; Sisman, Yavuz Selim

2018-01-01

This study set out with a threefold purpose: to examine (1) the oral communication strategies (CSs) employed by tertiary-level Turkish EFL learners, (2) the use of CSs based on exposure to English through audio-visual tools, university subject domain and gender differences, (3) the correlation between use of CSs and oral proficiency scores. To…

The Ethics of DeCSS Posting: Towards Assessing the Morality of the Internet Posting of DVD Copyright Circumvention Software

ERIC Educational Resources Information Center

Eschenfelder, Kristin R.; Howard, Robert Glenn; Desai, Anuj C.

2006-01-01

Introduction: We investigate the conditions under which posting software known as "DeCSS" on the Internet is ethical. DeCSS circumvents the access and copy control protection measures on commercial DVDs. Through our investigation, we point to limitations in current frameworks used to assess ethical computer based civil disobedience.…

Subliminal influence on preferences? A test of evaluative conditioning for brief visual conditioned stimuli using auditory unconditioned stimuli

PubMed Central

2017-01-01

In the field of evaluative conditioning (EC), two opposing theories—propositional single-process theory versus dual-process theory—are currently being discussed in the literature. The present set of experiments test a crucial prediction to adjudicate between these two theories: Dual-process theory postulates that evaluative conditioning can occur without awareness of the contingency between conditioned stimulus (CS) and unconditioned stimulus (US); in contrast, single-process propositional theory postulates that EC requires CS-US contingency awareness. In a set of three studies, we experimentally manipulate contingency awareness by presenting the CSs very briefly, thereby rendering it unlikely to be processed consciously. We address potential issues with previous studies on EC with subliminal or near-threshold CSs that limited their interpretation. Across two experiments, we consistently found an EC effect for CSs presented for 1000 ms and consistently failed to find an EC effect for briefly presented CSs. In a third pre-registered experiment, we again found evidence for an EC effect with CSs presented for 1000 ms, and we found some indication for an EC effect for CSs presented for 20 ms. PMID:28989730

Subliminal influence on preferences? A test of evaluative conditioning for brief visual conditioned stimuli using auditory unconditioned stimuli.

PubMed

Heycke, Tobias; Aust, Frederik; Stahl, Christoph

2017-09-01

In the field of evaluative conditioning (EC), two opposing theories-propositional single-process theory versus dual-process theory-are currently being discussed in the literature. The present set of experiments test a crucial prediction to adjudicate between these two theories: Dual-process theory postulates that evaluative conditioning can occur without awareness of the contingency between conditioned stimulus (CS) and unconditioned stimulus (US); in contrast, single-process propositional theory postulates that EC requires CS-US contingency awareness. In a set of three studies, we experimentally manipulate contingency awareness by presenting the CSs very briefly, thereby rendering it unlikely to be processed consciously. We address potential issues with previous studies on EC with subliminal or near-threshold CSs that limited their interpretation. Across two experiments, we consistently found an EC effect for CSs presented for 1000 ms and consistently failed to find an EC effect for briefly presented CSs. In a third pre-registered experiment, we again found evidence for an EC effect with CSs presented for 1000 ms, and we found some indication for an EC effect for CSs presented for 20 ms.

Revisiting a dogma: similar survival of patients with small bowel and gastric GIST. A population-based propensity score SEER analysis.

PubMed

Guller, Ulrich; Tarantino, Ignazio; Cerny, Thomas; Ulrich, Alexis; Schmied, Bruno M; Warschkow, Rene

2017-01-01

The objective of the present analysis was to assess whether small bowel gastrointestinal stromal tumor (GIST) is associated with worse cancer-specific survival (CSS) and overall survival (OS) compared with gastric GIST on a population-based level. Data on patients aged 18 years or older with histologically proven GIST was extracted from the SEER database from 1998 to 2011. OS and CSS for small bowel GIST were compared with OS and CSS for gastric GIST by application of adjusted and unadjusted Cox regression analyses and propensity score analyses. GIST were located in the stomach (n = 3011, 59 %), duodenum (n = 313, 6 %), jejunum/ileum (n = 1288, 25 %), colon (n = 139, 3 %), rectum (n = 172, 3 %), and extraviscerally (n = 173, 3 %). OS and CSS of patients with GIST in the duodenum [OS, HR 0.95, 95 % confidence interval (CI) 0.76-1.19; CSS, HR 0.99, 95 % CI 0.76-1.29] and in the jejunum/ileum (OS, HR 0.97, 95 % CI 0.85-1.10; CSS, HR = 0.95, 95 % CI 0.81-1.10) were similar to those of patients with gastric GIST in multivariate analyses. Conversely, OS and CSS of patients with GIST in the colon (OS, HR 1.40; 95 % CI 1.07-1.83; CSS, HR 1.89, 95 % CI 1.41-2.54) and in an extravisceral location (OS, HR 1.42, 95 % CI 1.14-1.77; CSS, HR = 1.43, 95 % CI 1.11-1.84) were significantly worse than those of patients with gastric GIST. Contrary to common belief, OS and CSS of patients with small bowel GIST are not statistically different from those of patients with gastric GIST when adjustment is made for confounding variables on a population-based level. The prognosis of patients with nongastric GIST is worse because of a colonic and extravisceral GIST location. These findings have implications regarding adjuvant treatment of GIST patients. Hence, the dogma that small bowel GIST patients have worse prognosis than gastric GIST patients and therefore should receive adjuvant treatment to a greater extent must be revisited.

Long-term PAH monitoring results from the Anacostia River active capping demonstration using polydimethylsiloxane (PDMS) fibers.

PubMed

Lampert, David J; Lu, Xiaoxia; Reible, Danny D

2013-03-01

In this paper, the long-term monitoring results for hydrophobic organic compounds, specifically polycyclic aromatic hydrocarbons (PAHs), from a field demonstration of capping contaminated sediments at the Anacostia River in Washington DC are presented and analyzed. In situ pore water concentrations in field-contaminated sediments in the demonstration caps were quantified using a polydimethylsiloxane (PDMS)-based passive sampling device. High resolution vertical pore water concentration profiles were measured using the device and were used to infer fate and transport of polycyclic aromatics hydrocarbons (PAHs) at the site. The derived pore water concentrations were compared with observed bioaccumulation and solid-phase concentration profiles to infer contaminant migration rates and mechanisms. Observed pore water concentrations were found to be a better predictor of bioaccumulation than solid-phase concentrations. Solid-phase concentrations were low in cores which implied containment of contamination; however pore water profiles showed that contaminant migration had occurred in the first few years after cap placement. The discrepancy is the result of the low sorption capacity of the sand. Because of surface re-contamination, low sorption capacity in the demonstration caps and strong tidal pumping effects, steady state contaminant profiles were reached in the caps several years after placement. Despite re-contamination at the surface, steady state concentrations in the capped areas showed decreased contamination levels relative to the control area.

Risk Management and Performance in the Balkans Support Contract

DTIC Science & Technology

2005-01-01

Defense contracts-United States-Case studies . 2. United States. Army- Procurement-Case studies . 3. Bosnia and Hercegovina-History, Military-20ts...24 3.1. Assessment of GAO Cost Study .................................. 72 3.2. Comparison of Potential Sources of Nonperformance...accepting inappropriate risks, what can it do about it? Case studies of CSS contracts can provide some answers. In this report, we present a case study of

Chemical, mechanical and biological properties of contemporary composite surface sealers.

PubMed

Anagnostou, Maria; Mountouris, George; Silikas, Nick; Kletsas, Dimitris; Eliades, George

2015-12-01

To evaluate the chemical, mechanical, and biological properties of modern composite surface sealers (CSS) having different compositions. The CSS products tested were Biscover LV (BC), Durafinish (DF), G-Coat Plus (GC), and Permaseal (PS). The tests performed were: (A): degree of conversion (DC%) by ATR-FTIR spectroscopy; (B): thickness of O2-inhibition layer by transmission optical microscopy; (C): surface hardness, 10 min after irradiation and following 1 week water storage, employing a Vickers indenter (VHN); (D): color (ΔE*) and gloss changes (ΔGU) after toothbrush abrasion, using L*a*b* colorimetry and glossimetry; (E): accelerated wear (GC,PS only) by an OHSU wear simulator plus 3D profilometric analysis, and (F): cytotoxicity testing of aqueous CSS eluents on human gingival fibroblast cultures employing the methyl-(3)H thymidine DNA labeling method. Statistical analyses included 1-way (A, B, ΔE*, ΔGU) and 2-way (C, F) ANOVAs, plus Tukey post hoc tests. Student's t-test was used to evaluate the results of the accelerated wear test (α=0.05 for all). The rankings of the statistical significant differences were: (A) PS (64.9)>DF,BC,GC (56.1-53.9) DC%; (B) DF,PS (12.3,9.8)>GC,BC (5.2,4.8) μm; (C): GC (37.6)>BC,DF (32.6,31.1)>PS (26.6) VHN (10 min/dry) and BC,DF (29.3,28.7)>GC(26.5)>PS(21.6) VHN (1w/water), with no significant material/storage condition interaction; (D): no differences were found among GC,DF,BC,PS (0.67-1.11) ΔE*, with all values within the visually acceptable range and PS,BC (32.8,29.4)>GC,DF (19.4,12.9) ΔGU; (E): no differences were found between GC and PS in volume loss (0.10,0.11 mm(3)), maximum (113.9,130.5 μm) and mean wear depths (30.3,27.5 μm); (F): at 1% v/v concentration, DF showed toxicity (23% vital cells vs 95-102% for others). However, at 5% v/v concentration DF (0%) and BC (9%) were the most toxic, whereas GC (58%) and PS (56%) showed moderate toxicity. Important chemical, mechanical, and biological properties exist among the CSS tested, which may affect their clinical performance. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

The effect of floor type on the performance, cleanliness, carcass characteristics and meat quality of dairy origin bulls.

PubMed

Murphy, V S; Lowe, D E; Lively, F O; Gordon, A W

2018-05-01

The aim of this study was to evaluate the effect of using different floor types to accommodate growing and finishing beef cattle on their performance, cleanliness, carcass characteristics and meat quality. In total, 80 dairy origin young bulls (mean initial live weight 224 kg (SD=28.4 kg)) were divided into 20 blocks with four animals each according to live weight. The total duration of the experimental period was 204 days. The first 101 days was defined as the growing period, with the remainder of the study defined as the finishing period. Cattle were randomly assigned within blocks to one of four floor type treatments, which included fully slatted flooring throughout the entire experimental period (CS); fully slatted flooring covered with rubber strips throughout the entire experimental period (RS); fully slatted flooring during the growing period and moved to a solid floor covered with straw bedding during the finishing period (CS-S) and fully slatted flooring during the growing period and moved to fully slatted flooring covered with rubber strips during the finishing period (CS-RS). Bulls were offered ad libitum grass silage supplemented with concentrates during the growing period. During the finishing period, bulls were offered concentrates supplemented with chopped barley straw. There was no significant effect of floor type on total dry matter intake (DMI), feed conversion ratio, daily live weight gain or back fat depth during the growing and finishing periods. Compared with bulls accommodated on CS, RS and CS-RS, bulls accommodated on CS-S had a significantly lower straw DMI (P<0.01). Although bulls accommodated on CS and CS-S were significantly dirtier compared with those accommodated on RS and CS-RS on days 50 (P<0.05) and 151 (P<0.01), there was no effect of floor type on the cleanliness of bulls at the end of the growing and finishing periods. There was also no significant effect of floor type on carcass characteristics or meat quality. However, bulls accommodated on CS-S had a tendency for less channel, cod and kidney fat (P=0.084) compared with those accommodated on CS, RS and CS-RS. Overall, floor type had no effect on the performance, cleanliness, carcass characteristics or meat quality of growing or finishing beef cattle.

Synthesis and Turnover of Embryonic Sea Urchin Ciliary Proteins during Selective Inhibition of Tubulin Synthesis and Assembly

PubMed Central

Stephens, Raymond E.

1997-01-01

When ciliogenesis first occurs in sea urchin embryos, the major building block proteins, tubulin and dynein, exist in substantial pools, but most 9+2 architectural proteins must be synthesized de novo. Pulse-chase labeling with [3H]leucine demonstrates that these proteins are coordinately up-regulated in response to deciliation so that regeneration ensues and the tubulin and dynein pools are replenished. Protein labeling and incorporation into already-assembled cilia is high, indicating constitutive ciliary gene expression and steady-state turnover. To determine whether either the synthesis of tubulin or the size of its available pool is coupled to the synthesis or turnover of the other 9+2 proteins in some feedback manner, fully-ciliated mid- or late-gastrula stage Strongylocentrotus droebachiensis embryos were pulse labeled in the presence of colchicine or taxol at concentrations that block ciliary growth. As a consequence of tubulin autoregulation mediated by increased free tubulin, no labeling of ciliary tubulin occurred in colchicine-treated embryos. However, most other proteins were labeled and incorporated into steady-state cilia at near-control levels in the presence of colchicine or taxol. With taxol, tubulin was labeled as well. An axoneme-associated 78 kDa cognate of the molecular chaperone HSP70 correlated with length during regeneration; neither colchicine nor taxol influenced the association of this protein in steady-state cilia. These data indicate that 1) ciliary protein synthesis and turnover is independent of tubulin synthesis or tubulin pool size; 2) steady-state incorporation of labeled proteins cannot be due to formation or elongation of cilia; 3) substantial tubulin exchange takes place in fully-motile cilia; and 4) chaperone presence and association in steady-state cilia is independent of background ciliogenesis, tubulin synthesis, and tubulin assembly state. PMID:9362062

Generation of sub-part-per-billion gaseous volatile organic compounds at ambient temperature by headspace diffusion of aqueous standards through decoupling between ideal and nonideal Henry's law behavior.

PubMed

Kim, Yong-Hyun; Kim, Ki-Hyun

2013-05-21

In the analysis of volatile organic compounds in air, the preparation of their gaseous standards at low (sub-ppb) concentration levels with high reliability is quite difficult. In this study, a simple dynamic headspace-based approach was evaluated as a means of generating vapor-phase volatile organic compounds from a liquid standard in an impinger at ambient temperature (25 °C). For a given sampling time, volatile organic compound vapor formed in the headspace was swept by bypassing the sweep gas through the impinger and collected four times in quick succession in separate sorbent tubes. In each experiment, a fresh liquid sample was used for each of the four sampling times (5, 10, 20, and 30 min) at a steady flow rate of 50 mL min(-1). The air-water partitioning at the most dynamic (earliest) sweeping stage was established initially in accord with ideal Henry's law, which was then followed by considerably reduced partitioning in a steady-state equilibrium (non-ideal Henry's law). The concentrations of gaseous volatile organic compounds, collected after the steady-state equilibrium, reached fairly constant values: for instance, the mole fraction of toluene measured at a sweeping interval of 10 and 30 min averaged 1.10 and 0.99 nmol mol(-1), respectively (after the initial 10 min sampling). In the second stage of our experiment, the effect of increasing the concentrations of liquid spiking standard was also examined by collecting sweep gas samples from two consecutive 10 min runs. The volatile organic compounds, collected in the first and second 10 min sweep gas samples, exhibited ideal and nonideal Henry's law behavior, respectively. From this observation, we established numerical relationships to predict the mole fraction (or mixing ratio) of each volatile organic compound in steady-state equilibrium in relation to the concentration of standard spiked into the system. This experimental approach can thus be used to produce sub-ppb levels of gaseous volatile organic compounds in a constant and predictable manner.

Equilibrium sampling through membranes (ESTM) of acidic organic pollutants using hollow fibre modules in continuous steady-state mode.

PubMed

Larsson, Niklas; Utterback, Karl; Toräng, Lars; Risberg, Johan; Gustafsson, Per; Mayer, Philipp; Jönsson, Jan Ke

2009-08-01

Hollow fibre (HF) membrane modules were applied in continuous mode for equilibrium sampling through membranes (ESTM) of polar organic pollutants. Phenolic compounds (chlorophenols, cresols and phenol) served as model substances and ESTM was tuned towards the measurement of freely dissolved concentrations (C(free)). HF membrane modules were constructed using thin-walled membrane, 1-m module length and low packing density in order to optimise the uptake kinetics of the analytes into the acceptor solution. Such custom made devices were tested and compared to commercially available modules. The former modules performed best for continuous ESTM. The custom made modules provided steady-state equilibrium within 20-40 min and enrichment that was in general agreement with calculated distribution ratios between acceptor and sample. In experiments during which sample concentration was changed, acceptor response time to decreased sample concentration was around 30 min for custom built modules. In the presence of commercial humic acids, analytes showed lower steady-state enrichment, which is due to a decrease in C(free). Continuous ESTM may be automated and is suggested for use in online determination of C(free) of pollutants and studies on sorption of pollutants. Future studies should include optimisation of the membrane liquid and factors regarding the residence time of the acceptor solution in the fibre lumen. Qualitative aspects of DOM should also be included, as natural DOM can be fractionated. C(free) could be correlated to DOM properties that have previously been shown to influence sorption, such as aromaticity, carboxylic acid content and molecular size.

Effect of ion concentration changes in the limited extracellular spaces on sarcolemmal ion transport and Ca2+ turnover in a model of human ventricular cardiomyocyte.

PubMed

Hrabcová, Dana; Pásek, Michal; Šimurda, Jiří; Christé, Georges

2013-12-13

We have developed a computer model of human cardiac ventricular myocyte (CVM), including t-tubular and cleft spaces with the aim of evaluating the impact of accumulation-depletion of ions in restricted extracellular spaces on transmembrane ion transport and ionic homeostasis in human CVM. The model was based on available data from human CVMs. Under steady state, the effect of ion concentration changes in extracellular spaces on [Ca2+]i-transient was explored as a function of critical fractions of ion transporters in t-tubular membrane (not documented for human CVM). Depletion of Ca2+ and accumulation of K+ occurring in extracellular spaces slightly affected the transmembrane Ca2+ flux, but not the action potential duration (APD90). The [Ca2+]i-transient was reduced (by 2%-9%), depending on the stimulation frequency, the rate of ion exchange between t-tubules and clefts and fractions of ion-transfer proteins in the t-tubular membrane. Under non-steady state, the responses of the model to changes of stimulation frequency were analyzed. A sudden increase of frequency (1-2.5 Hz) caused a temporal decrease of [Ca2+] in both extracellular spaces, a reduction of [Ca2+]i-transient (by 15%) and APD90 (by 13 ms). The results reveal different effects of activity-related ion concentration changes in human cardiac t-tubules (steady-state effects) and intercellular clefts (transient effects) in the modulation of membrane ion transport and Ca2+ turnover.

Serum biomarkers are similar in Churg-Strauss syndrome and hypereosinophilic syndrome

PubMed Central

Khoury, Paneez; Zagallo, Patricia; Talar-Williams, Cheryl; Santos, Carlo S.; Dinerman, Ellen; Holland, Nicole C.; Klion, Amy D.

2012-01-01

Rationale Churg-Strauss syndrome (CSS) and hypereosinophilic syndrome (HES) overlap considerably in clinical presentation. A reliable means of distinguishing between these groups of patients is needed, especially in the setting of glucocorticoid therapy. Methods A retrospective chart review of 276 adult subjects referred for evaluation of eosinophilia >1500/μl was performed, and subjects with a documented secondary cause of eosinophilia or a PDGFR-positive myeloproliferative neoplasm were excluded. The remaining subjects were assessed for the presence of American College of Rheumatology (ACR) criteria. Laboratory and clinical parameters were compared between subjects with biopsy-proven vasculitis (CSS; n=8), ≥4 ACR criteria (probable CSS; n=21), HES with asthma and/or sinusitis without other CSS-defining criteria (HESwAS; n=20), HES without asthma or sinusitis (HES; n=18), and normal controls (n=8). Serum biomarkers reported to be associated with CSS were measured using standard techniques. Results There were no differences between the subjects with definite or probable CSS or HES with respect to age, gender, or maintenance steroid dose. Serum CCL17, IL-8 and eotaxin levels were significantly increased in eosinophilic subjects as compared to normal controls, but were similar between the eosinophilic groups. Serum CCL17 correlated with eosinophil count (p<0.0001, r=0.73), but not with prednisone dose. Conclusions In patients with a history of asthma and sinusitis, distinguishing between ANCA-negative CSS and PDGFR-negative HES is difficult due to significant overlap in clinical presentation and biomarker profiles. PMID:22775568

Establishment and genetic characterization of ANGM-CSS, a novel, immortal cell line derived from a human glioblastoma multiforme.

PubMed

Notarangelo, Angelantonio; Trombetta, Domenico; D'Angelo, Vincenzo; Parrella, Paola; Palumbo, Orazio; Storlazzi, Clelia Tiziana; Impera, Luciana; Muscarella, Lucia Anna; La Torre, Antonella; Affuso, Andrea; Fazio, Vito Michele; Carella, Massimo; Zelante, Leopoldo

2014-03-01

Glioblastoma multiforme (World Health Organization, grade IV astrocytoma) is the most common and most aggressive malignant primary brain tumor. We report a novel cell line, designated as ANGM-CSS, which was established from a 56-year-old male patient with a surgically removed glioblastoma multiforme. The ANGM-CSS cell line was established in vitro and characterized using histological and immunohistochemical staining, classical and molecular cytogenetic analyses, molecular studies and functional assays using a xenograft model in immunodeficient animals. ANGM-CSS was positive for CD133, nestin and vimentin proteins, whereas GFAP showed staining only in a fraction of the cells. Cytogenetic and molecular cytogenetic analysis revealed a near-tetraploid karyotype, with a modal chromosome number from 88 to 91, and additional cytogenetic abnormalities, such as the t(6;14)(p12;q11.2), t(8;10)(q24.2;q21.1) and t(5;9)(q34;p21) unbalanced translocations. Moreover, ANGM-CSS showed amplification of the MET and EGFR genes whose overexpression was observed at the mRNA level. Interestingly, ANGM-CSS is tumorigenic when implanted in immunodeficient mice, and the cells obtained from the xenografts showed the same morphology and karyotype in vitro as the original cell line. ANGM-CSS represents a biologically relevant cell line to be used to investigate the molecular pathology of glioblastoma multiforme, also to evaluate the efficacy of novel therapeutic drugs in vitro.

Steady-State Plasma and Bronchopulmonary Concentrations of Intravenous Levofloxacin and Azithromycin in Healthy Adults

PubMed Central

Rodvold, Keith A.; Danziger, Larry H.; Gotfried, Mark H.

2003-01-01

The purpose of this study was to compare the concentrations of levofloxacin and azithromycin in steady-state plasma, epithelial lining fluid (ELF), and alveolar macrophage (AM) after intravenous administration. Thirty-six healthy, nonsmoking adult subjects were randomized to either intravenous levofloxacin (500 or 750 mg) or azithromycin (500 mg) once daily for five doses. Venipuncture and bronchoscopy with bronchoalveolar lavage were performed in each subject at either 4, 12, or 24 h after the start of the last antibiotic infusion. The mean concentrations of levofloxacin and azithromycin in plasma were similar to those previously published. The dosing regimens of levofloxacin achieved significantly (P < 0.05) higher concentrations in steady-state plasma than azithromycin during the 24 h after drug administration. The respective mean (± standard deviation) concentrations at 4, 12, and 24 h in ELF for 500 mg of levofloxacin were 11.01 ± 4.52, 2.50 ± 0.97, and 1.24 ± 0.55 μg/ml; those for 750 mg of levofloxacin were 12.94 ± 1.21, 6.04 ± 0.39, and 1.73 ± 0.78 μg/ml; and those for azithromycin were 1.70 ± 0.74, 1.27 ± 0.47, and 2.86 ± 1.75 μg/ml. The differences in concentrations in ELF among the two levofloxacin groups and azithromycin were significantly (P < 0.05) higher at the 4- and 12-h sampling times. The respective concentrations in AM for 500 mg of levofloxacin were 83.9 ± 53.2, 18.3 ± 6.7, and 5.6 ± 3.2 μg/ml; those for 750 mg of levofloxacin were 81.7 ± 37.0, 78.2 ± 55.4, and 13.3 ± 6.5 μg/ml; and those for azithromycin were 650 ± 259, 669 ± 311, and 734 ± 770 μg/ml. Azithromycin achieved significantly (P < 0.05) higher concentrations in AM than levofloxacin at all sampling times. The concentrations in ELF and AM following intravenous administration of levofloxacin and azithromycin were higher than concentrations in plasma. Further studies are needed to determine the clinical significance of such high intrapulmonary concentrations in patients with respiratory tract infections. PMID:12878504

Associations of gut-flora-dependent metabolite trimethylamine-N-oxide, betaine and choline with non-alcoholic fatty liver disease in adults.

PubMed

Chen, Yu-ming; Liu, Yan; Zhou, Rui-fen; Chen, Xiao-ling; Wang, Cheng; Tan, Xu-ying; Wang, Li-jun; Zheng, Rui-dan; Zhang, Hong-wei; Ling, Wen-hua; Zhu, Hui-lian

2016-01-08

Many studies suggest that trimethylamine-N-oxide (TMAO), a gut-flora-dependent metabolite of choline, contributes to the risk of cardiovascular diseases, but little is known for non-alcoholic fatty liver disease (NAFLD). We examined the association of circulating TMAO, choline and betaine with the presence and severity of NAFLD in Chinese adults. We performed a hospital-based case-control study (CCS) and a cross-sectional study (CSS). In the CCS, we recruited 60 biopsy-proven NAFLD cases and 35 controls (18-60 years) and determined serum concentrations of TMAO, choline and betaine by HPLC-MS/MS. For the CSS, 1,628 community-based adults (40-75 years) completed the blood tests and ultrasonographic NAFLD evaluation. In the CCS, analyses of covariance showed adverse associations of ln-transformed serum levels of TMAO, choline and betaine/choline ratio with the scores of steatosis and total NAFLD activity (NAS) (all P-trend <0.05). The CSS revealed that a greater severity of NAFLD was independently correlated with higher TMAO but lower betaine and betaine/choline ratio (all P-trend <0.05). No significant choline-NAFLD association was observed. Our findings showed adverse associations between the circulating TMAO level and the presence and severity of NAFLD in hospital- and community-based Chinese adults, and a favorable betaine-NAFLD relationship in the community-based participants.

Phytoextraction of Pb and Cd from a superfund soil: effects of amendments and croppings.

PubMed

Bricker, T J; Pichtel, J; Brown, H J; Simmons, M

2001-01-01

In a growth chamber, maize (Zea mays) and Indian mustard (Brassica juncea) were grown over two croppings in soil from a Superfund site (PbTotal = 65,200 mg/kg and CdTotal = 52mg/kg). Soil treatments consisted of ethylenediaminetetraacetic acid, sodium citrate and composted sewage sludge, each at two rates (EDTA .05%, EDTA .2%, citrate .05%, citrate .2%, CSS 5% and CSS 10%, respectively). In most cases, the EDTA and citrate treatments were superior in terms of solubilizing soil Pb for root uptake and translocation into above-ground biomass. In the first maize crop, the EDTA .2% treatment resulted in 2,435 and 9,389mg/kg Pb in shoot and root tissues, respectively. The CSS treatments typically resulted in lowest Pb and Cd removal efficiencies. Lead remaining in the soil after two croppings was mainly associated with the carbonate, organic, and residual fractions, which represent the less bioavailable forms. Soil Cd was generally more mobile for plant uptake than soil Pb. The EDTA .2% and citrate treatments were most successful in promoting Cd uptake by both maize and mustard. Although Pb concentrations (mg/kg tissue) were lower for maize than mustard, the former removed more total Pb (0.2 mg per pot, mean over all treatments), compared to mustard (0.03 mg), by virtue of its higher biomass production.

Associations of gut-flora-dependent metabolite trimethylamine-N-oxide, betaine and choline with non-alcoholic fatty liver disease in adults

PubMed Central

Chen, Yu-ming; Liu, Yan; Zhou, Rui-fen; Chen, Xiao-ling; Wang, Cheng; Tan, Xu-ying; Wang, Li-jun; Zheng, Rui-dan; Zhang, Hong-wei; Ling, Wen-hua; Zhu, Hui-lian

2016-01-01

Many studies suggest that trimethylamine-N-oxide (TMAO), a gut-flora-dependent metabolite of choline, contributes to the risk of cardiovascular diseases, but little is known for non-alcoholic fatty liver disease (NAFLD). We examined the association of circulating TMAO, choline and betaine with the presence and severity of NAFLD in Chinese adults. We performed a hospital-based case-control study (CCS) and a cross-sectional study (CSS). In the CCS, we recruited 60 biopsy-proven NAFLD cases and 35 controls (18–60 years) and determined serum concentrations of TMAO, choline and betaine by HPLC-MS/MS. For the CSS, 1,628 community-based adults (40-75 years) completed the blood tests and ultrasonographic NAFLD evaluation. In the CCS, analyses of covariance showed adverse associations of ln-transformed serum levels of TMAO, choline and betaine/choline ratio with the scores of steatosis and total NAFLD activity (NAS) (all P-trend <0.05). The CSS revealed that a greater severity of NAFLD was independently correlated with higher TMAO but lower betaine and betaine/choline ratio (all P-trend <0.05). No significant choline-NAFLD association was observed. Our findings showed adverse associations between the circulating TMAO level and the presence and severity of NAFLD in hospital- and community-based Chinese adults, and a favorable betaine-NAFLD relationship in the community-based participants. PMID:26743949

THERMAL PROPERTIES OF SECONDARY ORGANIC AEROSOLS

EPA Science Inventory

Volume concentrations of steady-state secondary organic aerosol (SOA) were measured in several hydrocarbon/NO_x irradiation experiments. These measurements were used to estimate the thermal behavior of the particles that may be formed in the atmosphere. These laborator...

A Model of Solid State Gas Sensors

NASA Astrophysics Data System (ADS)

Woestman, J. T.; Brailsford, A. D.; Shane, M.; Logothetis, E. M.

1997-03-01

Solid state gas sensors are widely used to measure the concentrations of gases such as CO, CH_4, C_3H_6, H_2, C_3H8 and O2 The applications of these sensors range from air-to-fuel ratio control in combustion processes including those in automotive engines and industrial furnaces to leakage detection of inflammable and toxic gases in domestic and industrial environments. As the need increases to accurately measure smaller and smaller concentrations, problems such as poor selectivity, stability and response time limit the use of these sensors. In an effort to overcome some of these limitations, a theoretical model of the transient behavior of solid state gas sensors has been developed. In this presentation, a model for the transient response of an electrochemical gas sensor to gas mixtures containing O2 and one reducing species, such as CO, is discussed. This model accounts for the transport of the reactive species to the sampling electrode, the catalyzed oxidation/reduction reaction of these species and the generation of the resulting electrical signal. The model will be shown to reproduce the results of published steady state models and to agree with experimental steady state and transient data.

Photosynthesis and Ribulose 1,5-Bisphosphate Concentrations in Intact Leaves of Xanthium strumarium L. 1

PubMed Central

Mott, Keith A.; Jensen, Richard G.; O'Leary, James W.; Berry, Joseph A.

1984-01-01

The interacting effects of the rate of ribulose 1,5-bisphosphate (RuBP) regeneration and the rate of RuBP utilization as influenced by the amount and activation of RuBP carboxylase on photosynthesis and RuBP concentrations were resolved in experiments which examined the kinetics of the response of photosynthesis and RuBP concentrations after step changes from a rate-saturating to a rate-limiting light intensity in Xanthium strumarium. Because RuBP carboxylase requires several minutes to deactivate in vivo, it was possible to observe the effect of reducing the rate of RuBP regeneration on the RuBP concentration at constant enzyme activation state by sampling very soon after reducing the light intensity. Samples taken over longer time periods showed the effect of changes in enzyme activation at constant RuBP regeneration rate on RuBP concentration and photosynthetic rate. Within 15 s of lowering the light intensity from 1500 to 600 microEinsteins per square meter per second the RuBP concentration in the leaves dropped below the enzyme active site concentration, indicating that RuBP regeneration rate was limiting for photosynthesis. After longer intervals of time, the RuBP concentration in the leaf increased as the RuBP carboxylase assumed a new steady state activation level. No change in the rate of photosynthesis was observed during the interval that RuBP concentration increased. It is concluded that the rate of photosynthesis at the lower light intensity was limited by the rate of RuBP regeneration and that parallel changes in the activation of RuBP carboxylase occurred such that concentrations of RuBP at steady state were not altered by changes in light intensity. PMID:16663982

Photosynthesis and Ribulose 1,5-Bisphosphate Concentrations in Intact Leaves of Xanthium strumarium L.

PubMed

Mott, K A; Jensen, R G; O'leary, J W; Berry, J A

1984-12-01

The interacting effects of the rate of ribulose 1,5-bisphosphate (RuBP) regeneration and the rate of RuBP utilization as influenced by the amount and activation of RuBP carboxylase on photosynthesis and RuBP concentrations were resolved in experiments which examined the kinetics of the response of photosynthesis and RuBP concentrations after step changes from a rate-saturating to a rate-limiting light intensity in Xanthium strumarium. Because RuBP carboxylase requires several minutes to deactivate in vivo, it was possible to observe the effect of reducing the rate of RuBP regeneration on the RuBP concentration at constant enzyme activation state by sampling very soon after reducing the light intensity. Samples taken over longer time periods showed the effect of changes in enzyme activation at constant RuBP regeneration rate on RuBP concentration and photosynthetic rate. Within 15 s of lowering the light intensity from 1500 to 600 microEinsteins per square meter per second the RuBP concentration in the leaves dropped below the enzyme active site concentration, indicating that RuBP regeneration rate was limiting for photosynthesis. After longer intervals of time, the RuBP concentration in the leaf increased as the RuBP carboxylase assumed a new steady state activation level. No change in the rate of photosynthesis was observed during the interval that RuBP concentration increased. It is concluded that the rate of photosynthesis at the lower light intensity was limited by the rate of RuBP regeneration and that parallel changes in the activation of RuBP carboxylase occurred such that concentrations of RuBP at steady state were not altered by changes in light intensity.

Churg-Strauss syndrome masquerading as an acute coronary syndrome.

PubMed

Triantafyllis, Andreas S; Sakadakis, Eleftherios A; Papafilippaki, Argyro; Katsimbri, Pelagia; Panou, Fotios; Anastasiou-Nana, Maria; Lekakis, Ioannis

2015-02-01

Churg-Strauss Syndrome (CSS) is a rare vasculitis with multiorgan involvement. Cardiac manifestations are common causing serious complications. We report a case of CSS masquerading as a non-ST elevation myocardial infarction with heart failure. CSS should be considered in the differential diagnosis of an acute coronary syndrome(ACS)with normal coronary arteries when history of asthma, peripheral eosinophilia and multisystemic involvement is present.

Influence of High-Pressure Processing at Low Temperature and Nisin on Listeria innocua Survival and Sensory Preference of Dry-Cured Cold-Smoked Salmon.

PubMed

Lebow, Noelle K; DesRocher, Lisa D; Younce, Frank L; Zhu, Mei-Jun; Ross, Carolyn F; Smith, Denise M

2017-12-01

Cold-smoked salmon (CSS) production lacks a validated kill step for Listeria monocytogenes. Although Listeria spp. are reduced by nisin or high-pressure processing (HPP), CSS muscle discoloration is often observed after HPP. Effects of nisin and low-temperature HPP on L. innocua survival (nonpathogenic surrogate for L. monocytogenes), spoilage organism growth, color, and sensory preference and peelability of CSS were studied. Cold-smoked sockeye salmon (Oncorhynchus nerka) fillets ± nisin (10 μg/g) were inoculated with a 3-strain L. innocua cocktail, vacuum-packaged, frozen at - 30 °C, and high-pressure processed in an ice slurry within an insulated sleeve. Initial experiments indicated that nisin and HPP for 120 s at 450 MPa (N450) and 600 MPa (N600) were most effective against L. innocua, and thus were selected for further storage studies. L. innocua in N450 and N600-treated CSS was reduced 2.63 ± 0.15 and 3.99 ± 0.34 Log CFU/g, respectively, immediately after HPP. L. innocua and spoilage growth were not observed in HPP-treated CSS during 36 d storage at 4 °C. Low-temperature HPP showed a smaller increase in lightness of CSS compared to ambient-temperature HPP performed in previous studies. Sensory evaluation indicated that overall liking of CSS treated with N450 and N600 were preferred over the control by 61% and 62% of panelists, respectively (P < 0.05). Peelability of sliced CSS was reduced by HPP (P < 0.05). Nisin in combination with low-temperature HPP was effective in controlling L. innocua in CSS while maintaining consumer acceptability. Cold-smoked salmon is a high-risk ready-to-eat product that may be contaminated with L. monocytogenes. Results showed that nisin combined with high-pressure processing at low temperature, reduced the population of Listeria and controlled the spoilage organisms during storage. As an added benefit, high-pressure processing at low temperature may reduce lightening of the salmon flesh, leading to enhanced consumer preference. © 2017 Institute of Food Technologists®.

Ecological Restoration of Coastal Sage Scrub and Its Potential Role in Habitat Conservation Plans.

PubMed

BOWLER

2000-07-01

Extensive acreage loss of coastal sage scrub (CSS), isolation of surviving stands, and the federal listing of several animal species with obligate relationships to this plant community, particularly the threatened California gnatcatcher (Polioptila californica), have led to attempts to create CSS to mitigate habitat lost to urban development and other causes. Many of these creations lie within habitat conservation plan (HCP) sites, and they could play a more prominent role by being repositories for plants taken from a single site having site-specific genetics. Among others, one technique that increases initial resemblance to natural stands uses digitized, to-scale photography, which has been ground-truthed to verify vascular plant associations, which appear as mosaics on a landscape. A combination of placing patches of salvaged, mature canopy plants within larger matrices of imprinted or container plant plots appears to significantly enhance immediate use by CSS obligate bird species, accelerate "spread" or expansion of CSS, and can also introduce many epiphytic taxa that otherwise would be slow or unable to occupy developing CSS creations. Reptile, amphibian, butterfly, and rodent diversity in a salvaged canopy restoration case study at the University of California, Irvine, showed CSS species foraging and inhabiting transplanted canopy patches. Using restoration techniques to expand existing CSS stands has more promise than creating isolated patches, and the creation of canopies resembling CSS mid-fire cycle stands is now common. Gnatcatchers and other birds use restorations for foraging and occasional nesting, and in some cases created stands along "biological corridors" appear to be useful to bird movement. Patches of transplanted sage scrub shrubs along habitat edges appear to break up linear edge effects. There are no data on which long-term survival, succession, or postfire behavior can be predicted for CSS restoration sites, and postfire community changes are not part of either mitigation or restoration planning at present. Long-term planning including burning is needed so that a fire-adapted habitat will develop. Restoration is important in retaining genetic resources, for ameliorating edge effects, as habitat extenders in buffer zones around HCP sites, and by providing areas into which natural stands can expand.

Ion Current Rectification, Limiting and Overlimiting Conductances in Nanopores

PubMed Central

van Oeffelen, Liesbeth; Van Roy, Willem; Idrissi, Hosni; Charlier, Daniel; Lagae, Liesbet; Borghs, Gustaaf

2015-01-01

Previous reports on Poisson-Nernst-Planck (PNP) simulations of solid-state nanopores have focused on steady state behaviour under simplified boundary conditions. These are Neumann boundary conditions for the voltage at the pore walls, and in some cases also Donnan equilibrium boundary conditions for concentrations and voltages at both entrances of the nanopore. In this paper, we report time-dependent and steady state PNP simulations under less restrictive boundary conditions, including Neumann boundary conditions applied throughout the membrane relatively far away from the nanopore. We simulated ion currents through cylindrical and conical nanopores with several surface charge configurations, studying the spatial and temporal dependence of the currents contributed by each ion species. This revealed that, due to slow co-diffusion of oppositely charged ions, steady state is generally not reached in simulations or in practice. Furthermore, it is shown that ion concentration polarization is responsible for the observed limiting conductances and ion current rectification in nanopores with asymmetric surface charges or shapes. Hence, after more than a decade of collective research attempting to understand the nature of ion current rectification in solid-state nanopores, a relatively intuitive model is retrieved. Moreover, we measured and simulated current-voltage characteristics of rectifying silicon nitride nanopores presenting overlimiting conductances. The similarity between measurement and simulation shows that overlimiting conductances can result from the increased conductance of the electric double-layer at the membrane surface at the depletion side due to voltage-induced polarization charges. The MATLAB source code of the simulation software is available via the website http://micr.vub.ac.be. PMID:25978328

Fracture Characterization in Reactive Fluid-Fractured Rock Systems Using Tracer Transport Data

NASA Astrophysics Data System (ADS)

Mukhopadhyay, S.

2014-12-01

Fractures, whether natural or engineered, exert significant controls over resource exploitation from contemporary energy sources including enhanced geothermal systems and unconventional oil and gas reserves. Consequently, fracture characterization, i.e., estimating the permeability, connectivity, and spacing of the fractures is of critical importance for determining the viability of any energy recovery program. While some progress has recently been made towards estimating these critical fracture parameters, significant uncertainties still remain. A review of tracer technology, which has a long history in fracture characterization, reveals that uncertainties exist in the estimated parameters not only because of paucity of scale-specific data but also because of knowledge gaps in the interpretation methods, particularly in interpretation of tracer data in reactive fluid-rock systems. We have recently demonstrated that the transient tracer evolution signatures in reactive fluid-rock systems are significantly different from those in non-reactive systems (Mukhopadhyay et al., 2013, 2014). For example, the tracer breakthrough curves in reactive fluid-fractured rock systems are expected to exhibit a long pseudo-state condition, during which tracer concentration does not change by any appreciable amount with passage of time. Such a pseudo-steady state condition is not observed in a non-reactive system. In this paper, we show that the presence of this pseudo-steady state condition in tracer breakthrough patterns in reactive fluid-rock systems can have important connotations for fracture characterization. We show that the time of onset of the pseudo-steady state condition and the value of tracer concentration in the pseudo-state condition can be used to reliably estimate fracture spacing and fracture-matrix interface areas.

Requirements for rapid plasmid ColE1 copy number adjustments: a mathematical model of inhibition modes and RNA turnover rates.

PubMed

Paulsson, J; Nordström, K; Ehrenberg, M

1998-01-01

The random distribution of ColE1 plasmids between the daughter cells at cell division introduces large copy number variations. Statistic variation associated with limited copy number in single cells also causes fluctuations to emerge spontaneously during the cell cycle. Efficient replication control out of steady state is therefore important to tame such stochastic effects of small numbers. In the present model, the dynamic features of copy number control are divided into two parts: first, how sharply the replication frequency per plasmid responds to changes in the concentration of the plasmid-coded inhibitor, RNA I, and second, how tightly RNA I and plasmid concentrations are coupled. Single (hyperbolic)- and multiple (exponential)-step inhibition mechanisms are compared out of steady state and it is shown how the response in replication frequency depends on the mode of inhibition. For both mechanisms, sensitivity of inhibition is "bought" at the expense of a rapid turnover of a replication preprimer, RNA II. Conventional, single-step, inhibition kinetics gives a sloppy replication control even at high RNA II turnover rates, whereas multiple-step inhibition has the potential of working with unlimited precision. When plasmid concentration changes rapidly, RNA I must be degraded rapidly to be "up to date" with the change. Adjustment to steady state is drastically impaired when the turnover rate constants of RNA I decrease below certain thresholds, but is basically unaffected for a corresponding increase. Several features of copy number control that are shown to be crucial for the understanding of ColE1-type plasmids still remain to be experimentally characterized. It is shown how steady-state properties reflect dynamics at the heart of regulation and therefore can be used to discriminate between fundamentally different copy number control mechanisms. The experimental tests of the predictions made require carefully planned assays, and some suggestions for suitable experiments arise naturally from the present work. It is also discussed how the presence of the Rom protein may affect dynamic qualities of copy number control. Copyright 1998 Academic Press.

Coupled laboratory experiments and numerical models for generating ice-depth profiles of steady-state hydrogen peroxide concentrations on radiolytically processed icy worlds.

NASA Astrophysics Data System (ADS)

Hand, K. P.; Carlson, R. W.

2007-12-01

The presence of hydrogen peroxide and condensed phase molecular oxygen on the surface of Europa is now well established [1,2] and laboratory experiments have repeatedly demonstrated the viability of various radiolytic processes for explaining the observations [see e.g. 3, 4]. To date, however, both the Europa observations and the laboratory work have been limited to only the upper few, or few tens of microns, of ice. The spectrum of charged particles incident on the surface of Europa penetrates deeper, and deposits energy over a much greater range, than any laboratory experiment has aimed to replicate [5, 6]. Here we present results from laboratory work on hydrogen peroxide production using energetic electrons (4 keV - 16 keV) and couple these results with a numerical model for the integrated steady-state density of hydrogen peroxide as a function of depth into the ice. Production rates and steady-state peroxide levels for a range of initial electron energies are used to generate functions for the number of peroxide molecules produced per initial electron as it penetrates through the ice. We examined the electron energy spectrum from 0.01 MeV to 10 MeV and accounted for electrons incident to the surface over the solid angle from cosine(theta) = 0.3-1.0, where theta is the angle from the normal to the surface. We found that, accounting for production and destruction as a function of energy deposition, steady-state hydrogen peroxide concentrations resulting from electron radiolysis likely increases by a factor of a few to an order of magnitude at a depth of a few hundred microns. In other words, the 0.13 percent by number abundance of peroxide observed by NIMS [1] may be a low-end value; at depth the peroxide concentration could increase to a few percent by number relative to water. [1] Carlson et al. 1999. [2] Spencer and Calvin, 2002. [3] Moore and Hudson, 2000. [4] Loeffler et al., 2006. [5] Cooper et al., 2001 [6] Paranicas et al., 2001.

Quantifying biological integrity of California sage scrub communities using plant life-form cover.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hamada, Y.; Stow, D. A.; Franklin, J.

2010-01-01

The California sage scrub (CSS) community type in California's Mediterranean-type ecosystems supports a large number of rare, threatened, and endangered species, and is critically degraded and endangered. Monitoring ecological variables that provide information about community integrity is vital to conserving these biologically diverse communities. Fractional cover of true shrub, subshrub, herbaceous vegetation, and bare ground should fill information gaps between generalized vegetation type maps and detailed field-based plot measurements of species composition and provide an effective means for quantifying CSS community integrity. Remote sensing is the only tool available for estimating spatially comprehensive fractional cover over large extent, and fractionalmore » cover of plant life-form types is one of the measures of vegetation state that is most amenable to remote sensing. The use of remote sensing does not eliminate the need for either field surveying or vegetation type mapping; rather it will likely require a combination of approaches to reliably estimate life-form cover and to provide comprehensive information for communities. According to our review and synthesis, life-form fractional cover has strong potential for providing ecologically meaningful intermediate-scale information, which is unattainable from vegetation type maps and species-level field measurements. Thus, we strongly recommend incorporating fractional cover of true shrub, subshrub, herb, and bare ground in CSS community monitoring methods. Estimating life-form cover at a 25 m x 25 m spatial scale using remote sensing would be an appropriate approach for initial implementation. Investigation of remote sensing techniques and an appropriate spatial scale; collaboration of resource managers, biologists, and remote sensing specialists, and refinement of protocols are essential for integrating life-form fractional cover mapping into strategies for sustainable long-term CSS community management.« less

Use of extractive distillation to produce concentrated nitric acid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Campbell, P.C.; Griffin, T.P.; Irwin, C.F.

1981-04-01

Concentrated nitric acid (> 95 wt %) is needed for the treatment of off-gases from a fuels-reprocessing plant. The production of concentrated nitric acid by means of extractive distillation in the two-pot apparatus was studied to determine the steady-state behavior of the system. Four parameters, EDP volume (V/sub EDP/) and temperature (T/sub EDP/), acid feed rate, and solvent recycle, were independently varied. The major response factors were percent recovery (CPRR) and product purity (CCP). Stage efficiencies also provided information about the system response. Correlations developed for the response parameters are: CPRR = 0.02(V/sub EDP/ - 800 cc) + 53.5; CCPmore » = -0.87 (T/sub EDP/ - 140/sup 0/C) + 81; eta/sub V,EDP/ = 9.1(F/sub feed/ - 11.5 cc/min) - 0.047(V/sub EDP/ - 800 cc) - 2.8(F/sub Mg(NO/sub 3/)/sub 2// - 50 cc/min) + 390; and eta/sub L,EDP/ = 1.9(T/sub EDP/ - 140/sup 0/C) + 79. A computer simulation of the process capable of predicting steady-state conditions was developed, but it requires further work.« less

Development of steady-state model for MSPT and detailed analyses of receiver

NASA Astrophysics Data System (ADS)

Yuasa, Minoru; Sonoda, Masanori; Hino, Koichi

2016-05-01

Molten salt parabolic trough system (MSPT) uses molten salt as heat transfer fluid (HTF) instead of synthetic oil. The demonstration plant of MSPT was constructed by Chiyoda Corporation and Archimede Solar Energy in Italy in 2013. Chiyoda Corporation developed a steady-state model for predicting the theoretical behavior of the demonstration plant. The model was designed to calculate the concentrated solar power and heat loss using ray tracing of incident solar light and finite element modeling of thermal energy transferred into the medium. This report describes the verification of the model using test data on the demonstration plant, detailed analyses on the relation between flow rate and temperature difference on the metal tube of receiver and the effect of defocus angle on concentrated power rate, for solar collector assembly (SCA) development. The model is accurate to an extent of 2.0% as systematic error and 4.2% as random error. The relationships between flow rate and temperature difference on metal tube and the effect of defocus angle on concentrated power rate are shown.

Characterization of actin filament severing by actophorin from Acanthamoeba castellanii

PubMed Central

1991-01-01

Actophorin is an abundant 15-kD actinbinding protein from Acanthamoeba that is thought to form a nonpolymerizable complex with actin monomers and also to reduce the viscosity of polymerized actin by severing filaments (Cooper et al., 1986. J. Biol. Chem. 261:477-485). Homologous proteins have been identified in sea urchin, chicken, and mammalian tissues. Chemical crosslinking produces a 1:1 covalent complex of actin and actophorin. Actophorin and profilin compete for crosslinking to actin monomers. The influence of actophorin on the steady-state actin polymer concentration gave a Kd of 0.2 microM for the complex of actophorin with actin monomers. Several new lines of evidence, including assays for actin filament ends by elongation rate and depolymerization rate, show that actophorin severs actin filaments both at steady state and during spontaneous polymerization. This is confirmed by direct observation in the light microscope and by showing that the effects of actophorin on the low shear viscosity of polymerized actin cannot be explained by monomer sequestration. The severing activity of actophorin is strongly inhibited by stoichiometric concentrations of phalloidin or millimolar concentrations of inorganic phosphate. PMID:1757465

Long-Range (Forster) Electronic Energy Transfer: A Laboratory Experiment.

ERIC Educational Resources Information Center

Berkovic, G.

1984-01-01

An experiment which measures the steady-state fluorescence of pyrene (the donor) in the presence of varying concentrations of acridine orange (the acceptor) in ethyline glycol solutions is described. Background information, equipment needed, and procedures used are included. (JN)

Central sensitivity syndromes: a new paradigm and group nosology for fibromyalgia and overlapping conditions, and the related issue of disease versus illness.

PubMed

Yunus, Muhammad B

2008-06-01

To discuss the current terminologies used for fibromyalgia syndrome (FMS) and related overlapping conditions, to examine if central sensitivity syndromes (CSS) is the appropriate nosology for these disorders, and to explore the issue of disease versus illness. A literature search was performed through PubMed, Web of Science, and ScienceDirect using a number of keywords, eg, functional somatic syndromes, somatoform disorders, medically unexplained symptoms, organic and nonorganic, and diseases and illness. Relevant articles were then reviewed and representative ones cited. Terminologies currently used for CSS conditions predominantly represent a psychosocial construct and are inappropriate. On the other hand, CSS seems to be the logical nosology based on a biopsychosocial model. Such terms as "medically unexplained symptoms," "somatization," "somatization disorder," and "functional somatic syndromes" in the context of CSS should be abandoned. Given current scientific knowledge, the concept of disease-illness dualism has no rational basis and impedes proper patient-physician communication, resulting in poor patient care. The concept of CSS is likely to promote research, education, and proper patient management. CSS seems to be a useful paradigm and an appropriate terminology for FMS and related conditions. The disease-illness, as well as organic/non-organic dichotomy, should be rejected.

Worksite adjustments and work ability among employed cancer survivors.

PubMed

Torp, Steffen; Nielsen, Roy A; Gudbergsson, Sævar B; Dahl, Alv A

2012-09-01

This study was conducted to determine how many cancer survivors (CSs) make worksite adjustments and what kinds of adjustments they make. Changes in work ability among employed CSs were explored, and clinical, sociodemographic, and work-related factors associated with the current total work ability were studied. CSs of the ten most common invasive types of cancer for men and women in Norway completed a mailed questionnaire 15-39 months after being diagnosed with cancer. Included in the analyses were all participants who worked both at the time of diagnosis and at the time of the survey and who had not changed their labor force status since diagnosis (n = 563). The current total work ability was compared to the lifetime best (0-10 score). Twenty-six percent of the employed CSs had made adjustments at work, and the most common adjustment was changing the number of work hours per week. Despite the fact that 31% and 23% reported reduced physical and mental work abilities, respectively, more than 90% of the CSs reported that they coped well with their work demands. The mean total work ability score was high (8.6) among both men and women. Being self-employed and working part-time at the time of diagnosis showed significant negative correlations with total work ability, while a favorable psychosocial work environment showed a significant positive correlation. CSs with low work ability were more often in contact with the occupational health service and also made more worksite adjustments than others. The prospects of future work life seem optimistic for Norwegian employed CSs who return to work relatively soon after primary treatment.

User Interface Design in Medical Distributed Web Applications.

PubMed

Serban, Alexandru; Crisan-Vida, Mihaela; Mada, Leonard; Stoicu-Tivadar, Lacramioara

2016-01-01

User interfaces are important to facilitate easy learning and operating with an IT application especially in the medical world. An easy to use interface has to be simple and to customize the user needs and mode of operation. The technology in the background is an important tool to accomplish this. The present work aims to creating a web interface using specific technology (HTML table design combined with CSS3) to provide an optimized responsive interface for a complex web application. In the first phase, the current icMED web medical application layout is analyzed, and its structure is designed using specific tools, on source files. In the second phase, a new graphic adaptable interface to different mobile terminals is proposed, (using HTML table design (TD) and CSS3 method) that uses no source files, just lines of code for layout design, improving the interaction in terms of speed and simplicity. For a complex medical software application a new prototype layout was designed and developed using HTML tables. The method uses a CSS code with only CSS classes applied to one or multiple HTML table elements, instead of CSS styles that can be applied to just one DIV tag at once. The technique has the advantage of a simplified CSS code, and a better adaptability to different media resolutions compared to DIV-CSS style method. The presented work is a proof that adaptive web interfaces can be developed just using and combining different types of design methods and technologies, using HTML table design, resulting in a simpler to learn and use interface, suitable for healthcare services.

A study of work changes due to cancer in tumor-free primary-treated cancer patients. A NOCWO study.

PubMed

Gudbergsson, Saevar Berg; Fosså, Sophie D; Dahl, Alv A

2008-10-01

The goal of this study is to explore the characteristics of tumor-free cancer survivors (CSs) who after their primary treatment were still working but made work changes due to cancer and compare them to survivors who did not. The sample consisted of 431 CSs (219 females with breast cancer, 212 males with testicular (N = 150) or prostate cancer (N = 62)) diagnosed 2-6 years prior to the study. All CSs had good prognosis and had returned to work after primary treatment. All CSs filled in a mailed questionnaire covering demography, morbidity, life style, mental distress, fatigue, quality of life and job strain. Seventy-two CSs (17%) had made work changes due to cancer during the observation period, and 359 (83%) had not. Among CSs who made work changes, significantly more were females; they showed significantly poorer physical and mental work ability, worked fewer hours per week, reported more comorbidity, and had lower physical and mental quality of life and more neuroticism, compared to the nonchange group. Work changes were moderately correlated with current work ability. The majority of CSs did not report any work changes due to cancer during the 2-6-year observation period, which is an encouraging finding. A minority had done work changes, and this group consisted mainly of women and was also characterized by poorer physical and mental quality of life and poorer mental work ability due to cancer. The issue of work changes and work ability should be considered in the follow-up of cancer survivors.

Serum biomarkers are similar in Churg-Strauss syndrome and hypereosinophilic syndrome.

PubMed

Khoury, P; Zagallo, P; Talar-Williams, C; Santos, C S; Dinerman, E; Holland, N C; Klion, A D

2012-09-01

Churg-Strauss syndrome (CSS) and hypereosinophilic syndrome (HES) overlap considerably in clinical presentation. A reliable means of distinguishing between these groups of patients is needed, especially in the setting of glucocorticoid therapy. A retrospective chart review of 276 adult subjects referred for evaluation of eosinophilia > 1500/μl was performed, and subjects with a documented secondary cause of eosinophilia or a PDGFR -positive myeloproliferative neoplasm were excluded. The remaining subjects were assessed for the presence of American College of Rheumatology (ACR) criteria. Laboratory and clinical parameters were compared between subjects with biopsy-proven vasculitis (CSS; n = 8), ≥4 ACR criteria (probable CSS; n = 21), HES with asthma and/or sinusitis without other CSS-defining criteria (HESwAS; n = 20), HES without asthma or sinusitis (HES; n = 18), and normal controls (n = 8). Serum biomarkers reported to be associated with CSS were measured using standard techniques. There were no differences between the subjects with definite or probable CSS or HES with respect to age, gender, or maintenance steroid dose. Serum CCL17, IL-8, and eotaxin levels were significantly increased in eosinophilic subjects as compared to normal controls, but were similar between the eosinophilic groups. Serum CCL17 correlated with eosinophil count (P < 0.0001, r = 0.73), but not with prednisone dose. In patients with a history of asthma and sinusitis, distinguishing between ANCA-negative CSS and PDGFR-negative HES is difficult because of significant overlap in clinical presentation and biomarker profiles. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.

All Spin Artificial Neural Networks Based on Compound Spintronic Synapse and Neuron.

PubMed

Zhang, Deming; Zeng, Lang; Cao, Kaihua; Wang, Mengxing; Peng, Shouzhong; Zhang, Yue; Zhang, Youguang; Klein, Jacques-Olivier; Wang, Yu; Zhao, Weisheng

2016-08-01

Artificial synaptic devices implemented by emerging post-CMOS non-volatile memory technologies such as Resistive RAM (RRAM) have made great progress recently. However, it is still a big challenge to fabricate stable and controllable multilevel RRAM. Benefitting from the control of electron spin instead of electron charge, spintronic devices, e.g., magnetic tunnel junction (MTJ) as a binary device, have been explored for neuromorphic computing with low power dissipation. In this paper, a compound spintronic device consisting of multiple vertically stacked MTJs is proposed to jointly behave as a synaptic device, termed as compound spintronic synapse (CSS). Based on our theoretical and experimental work, it has been demonstrated that the proposed compound spintronic device can achieve designable and stable multiple resistance states by interfacial and materials engineering of its components. Additionally, a compound spintronic neuron (CSN) circuit based on the proposed compound spintronic device is presented, enabling a multi-step transfer function. Then, an All Spin Artificial Neural Network (ASANN) is constructed with the CSS and CSN circuit. By conducting system-level simulations on the MNIST database for handwritten digital recognition, the performance of such ASANN has been investigated. Moreover, the impact of the resolution of both the CSS and CSN and device variation on the system performance are discussed in this work.

Climbing fibers predict movement kinematics and performance errors.

PubMed

Streng, Martha L; Popa, Laurentiu S; Ebner, Timothy J

2017-09-01

Requisite for understanding cerebellar function is a complete characterization of the signals provided by complex spike (CS) discharge of Purkinje cells, the output neurons of the cerebellar cortex. Numerous studies have provided insights into CS function, with the most predominant view being that they are evoked by error events. However, several reports suggest that CSs encode other aspects of movements and do not always respond to errors or unexpected perturbations. Here, we evaluated CS firing during a pseudo-random manual tracking task in the monkey ( Macaca mulatta ). This task provides extensive coverage of the work space and relative independence of movement parameters, delivering a robust data set to assess the signals that activate climbing fibers. Using reverse correlation, we determined feedforward and feedback CSs firing probability maps with position, velocity, and acceleration, as well as position error, a measure of tracking performance. The direction and magnitude of the CS modulation were quantified using linear regression analysis. The major findings are that CSs significantly encode all three kinematic parameters and position error, with acceleration modulation particularly common. The modulation is not related to "events," either for position error or kinematics. Instead, CSs are spatially tuned and provide a linear representation of each parameter evaluated. The CS modulation is largely predictive. Similar analyses show that the simple spike firing is modulated by the same parameters as the CSs. Therefore, CSs carry a broader array of signals than previously described and argue for climbing fiber input having a prominent role in online motor control. NEW & NOTEWORTHY This article demonstrates that complex spike (CS) discharge of cerebellar Purkinje cells encodes multiple parameters of movement, including motor errors and kinematics. The CS firing is not driven by error or kinematic events; instead it provides a linear representation of each parameter. In contrast with the view that CSs carry feedback signals, the CSs are predominantly predictive of upcoming position errors and kinematics. Therefore, climbing fibers carry multiple and predictive signals for online motor control. Copyright © 2017 the American Physiological Society.

Pharmacokinetic Evaluation of Oral Levofloxacin in Human Immunodeficiency Virus-Infected Subjects Receiving Concomitant Antiretroviral Therapy

PubMed Central

Villani, P.; Viale, P.; Signorini, L.; Cadeo, B.; Marchetti, F.; Villani, A.; Fiocchi, C.; Regazzi, M. B.; Carosi, G.

2001-01-01

The purpose of this study was to evaluate the pharmacokinetics (PK) profile of oral levofloxacin in human immunodeficiency virus-positive patients in steady-state treatment with nelfinavir (NFV) or with efavirenz (EFV) and to determine the effects of levofloxacin on the PK parameters of these two antiretroviral agents. For levofloxacin, plasma samples were obtained at steady state during a 24-h dosing interval. Plasma NFV and EFV concentrations were evaluated before and after 4 days of levofloxacin treatment. Levofloxacin PK do not seem affected by NFV and EFV. There was no significant difference between NFV and EFV plasma levels obtained with and without levofloxacin. PMID:11408245

Communication: Limitations of the stochastic quasi-steady-state approximation in open biochemical reaction networks

NASA Astrophysics Data System (ADS)

Thomas, Philipp; Straube, Arthur V.; Grima, Ramon

2011-11-01

It is commonly believed that, whenever timescale separation holds, the predictions of reduced chemical master equations obtained using the stochastic quasi-steady-state approximation are in very good agreement with the predictions of the full master equations. We use the linear noise approximation to obtain a simple formula for the relative error between the predictions of the two master equations for the Michaelis-Menten reaction with substrate input. The reduced approach is predicted to overestimate the variance of the substrate concentration fluctuations by as much as 30%. The theoretical results are validated by stochastic simulations using experimental parameter values for enzymes involved in proteolysis, gluconeogenesis, and fermentation.

Differential equation methods for simulation of GFP kinetics in non-steady state experiments.

PubMed

Phair, Robert D

2018-03-15

Genetically encoded fluorescent proteins, combined with fluorescence microscopy, are widely used in cell biology to collect kinetic data on intracellular trafficking. Methods for extraction of quantitative information from these data are based on the mathematics of diffusion and tracer kinetics. Current methods, although useful and powerful, depend on the assumption that the cellular system being studied is in a steady state, that is, the assumption that all the molecular concentrations and fluxes are constant for the duration of the experiment. Here, we derive new tracer kinetic analytical methods for non-steady state biological systems by constructing mechanistic nonlinear differential equation models of the underlying cell biological processes and linking them to a separate set of differential equations governing the kinetics of the fluorescent tracer. Linking the two sets of equations is based on a new application of the fundamental tracer principle of indistinguishability and, unlike current methods, supports correct dependence of tracer kinetics on cellular dynamics. This approach thus provides a general mathematical framework for applications of GFP fluorescence microscopy (including photobleaching [FRAP, FLIP] and photoactivation to frequently encountered experimental protocols involving physiological or pharmacological perturbations (e.g., growth factors, neurotransmitters, acute knockouts, inhibitors, hormones, cytokines, and metabolites) that initiate mechanistically informative intracellular transients. When a new steady state is achieved, these methods automatically reduce to classical steady state tracer kinetic analysis. © 2018 Phair. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Study of impurity effects on CFETR steady-state scenario by self-consistent integrated modeling

NASA Astrophysics Data System (ADS)

Shi, Nan; Chan, Vincent S.; Jian, Xiang; Li, Guoqiang; Chen, Jiale; Gao, Xiang; Shi, Shengyu; Kong, Defeng; Liu, Xiaoju; Mao, Shifeng; Xu, Guoliang

2017-12-01

Impurity effects on fusion performance of China fusion engineering test reactor (CFETR) due to extrinsic seeding are investigated. An integrated 1.5D modeling workflow evolves plasma equilibrium and all transport channels to steady state. The one modeling framework for integrated tasks framework is used to couple the transport solver, MHD equilibrium solver, and source and sink calculations. A self-consistent impurity profile constructed using a steady-state background plasma, which satisfies quasi-neutrality and true steady state, is presented for the first time. Studies are performed based on an optimized fully non-inductive scenario with varying concentrations of Argon (Ar) seeding. It is found that fusion performance improves before dropping off with increasing {{Z}\\text{eff}} , while the confinement remains at high level. Further analysis of transport for these plasmas shows that low-k ion temperature gradient modes dominate the turbulence. The decrease in linear growth rate and resultant fluxes of all channels with increasing {{Z}\\text{eff}} can be traced to impurity profile change by transport. The improvement in confinement levels off at higher {{Z}\\text{eff}} . Over the regime of study there is a competition between the suppressed transport and increasing radiation that leads to a peak in the fusion performance at {{Z}\\text{eff}} (~2.78 for CFETR). Extrinsic impurity seeding to control divertor heat load will need to be optimized around this value for best fusion performance.

A quantitative approach to aquifer vulnerability mapping

NASA Astrophysics Data System (ADS)

Connell, L. D.; Daele, Gerd van den

2003-05-01

This paper presents a procedure for calculating the transport to groundwater of surface-released contaminants. The approach is derived from a series of analytical and semi-analytical solutions to the advection-dispersion equation that include root zone and unsaturated water movement effects on the transport process. The steady-state form of these equations provides an efficient means of calculating the maximum concentration at the watertable and therefore has potential for use in vulnerability mapping. A two-layer approach is used in the solutions to represent the unsaturated profile, with the root zone corresponding to the upper layer where evapotranspiration can occur and transport properties can be in contrast to the rest of the profile. A novel transformation is applied to the advection-dispersion equation that considerably simplifies the way in which water movement is represented. To provide a combined flow and transport model an approximate procedure for water movement, using averages of the infiltration and transpiration rates with a novel, simple, quasi-steady state solution, is presented that can be used in conjunction with the solutions to the advection-dispersion equation. This quasi-steady state approximation for water movement allows for layering in the soil profile and root water uptake. Results from the combined quasi-steady state water movement and semi-analytical solute transport procedure compare well with numerical solutions to the coupled unsaturated flow and solute transport equations in a series of hypothetical simulations.

Mimicking Nonequilibrium Steady States with Time-Periodic Driving

DTIC Science & Technology

2016-08-29

nonequilibrium steady states, and vice versa, within the theoretical framework of discrete-state stochastic thermodynamics . Nonequilibrium steady states...equilibrium [2], spontaneous relaxation towards equilibrium [3], nonequilibrium steady states generated by fixed thermodynamic forces [4], and stochastic pumps...paradigm, a system driven by fixed thermodynamic forces—such as temperature gradients or chemical potential differences— reaches a steady state in

Local sensitivity analysis for inverse problems solved by singular value decomposition

USGS Publications Warehouse

Hill, M.C.; Nolan, B.T.

2010-01-01

Local sensitivity analysis provides computationally frugal ways to evaluate models commonly used for resource management, risk assessment, and so on. This includes diagnosing inverse model convergence problems caused by parameter insensitivity and(or) parameter interdependence (correlation), understanding what aspects of the model and data contribute to measures of uncertainty, and identifying new data likely to reduce model uncertainty. Here, we consider sensitivity statistics relevant to models in which the process model parameters are transformed using singular value decomposition (SVD) to create SVD parameters for model calibration. The statistics considered include the PEST identifiability statistic, and combined use of the process-model parameter statistics composite scaled sensitivities and parameter correlation coefficients (CSS and PCC). The statistics are complimentary in that the identifiability statistic integrates the effects of parameter sensitivity and interdependence, while CSS and PCC provide individual measures of sensitivity and interdependence. PCC quantifies correlations between pairs or larger sets of parameters; when a set of parameters is intercorrelated, the absolute value of PCC is close to 1.00 for all pairs in the set. The number of singular vectors to include in the calculation of the identifiability statistic is somewhat subjective and influences the statistic. To demonstrate the statistics, we use the USDA’s Root Zone Water Quality Model to simulate nitrogen fate and transport in the unsaturated zone of the Merced River Basin, CA. There are 16 log-transformed process-model parameters, including water content at field capacity (WFC) and bulk density (BD) for each of five soil layers. Calibration data consisted of 1,670 observations comprising soil moisture, soil water tension, aqueous nitrate and bromide concentrations, soil nitrate concentration, and organic matter content. All 16 of the SVD parameters could be estimated by regression based on the range of singular values. Identifiability statistic results varied based on the number of SVD parameters included. Identifiability statistics calculated for four SVD parameters indicate the same three most important process-model parameters as CSS/PCC (WFC1, WFC2, and BD2), but the order differed. Additionally, the identifiability statistic showed that BD1 was almost as dominant as WFC1. The CSS/PCC analysis showed that this results from its high correlation with WCF1 (-0.94), and not its individual sensitivity. Such distinctions, combined with analysis of how high correlations and(or) sensitivities result from the constructed model, can produce important insights into, for example, the use of sensitivity analysis to design monitoring networks. In conclusion, the statistics considered identified similar important parameters. They differ because (1) with CSS/PCC can be more awkward because sensitivity and interdependence are considered separately and (2) identifiability requires consideration of how many SVD parameters to include. A continuing challenge is to understand how these computationally efficient methods compare with computationally demanding global methods like Markov-Chain Monte Carlo given common nonlinear processes and the often even more nonlinear models.

Measurement and Perturbation of Morphogen Lifetime: Effects on Gradient Shape

PubMed Central

Drocco, Jeffrey A.; Grimm, Oliver; Tank, David W.; Wieschaus, Eric

2011-01-01

Protein lifetime is of critical importance for most biological processes and plays a central role in cell signaling and embryonic development, where it impacts the absolute concentration of signaling molecules and, potentially, the shape of morphogen gradients. Early conceptual and mathematical models of gradient formation proposed that steady-state gradients are established by an equilibration between the lifetime of a morphogen and its rates of synthesis and diffusion, though whether gradients in fact reach steady state before being read out is a matter of controversy. In any case, this class of models predicts that protein lifetime is a key determinant of both the time to steady state and the spatial extent of a gradient. Using a method that employs repeated photoswitching of a fusion of the morphogen Bicoid (Bcd) and the photoconvertible fluorescent protein Dronpa, we measure and modify the lifetime of Dronpa-Bcd in living Drosophila embryos. We find that the lifetime of Bcd is dynamic, changing from 50 min before mitotic cycle 14 to 15 min during cellularization. Moreover, by measuring total quantities of Bcd over time, we find that the gradient does not reach steady state. Finally, using a nearly continuous low-level conversion to the dark state of Dronpa-Bcd to mimic the effect of increased degradation, we demonstrate that perturbation of protein lifetime changes the characteristic length of the gradient, providing direct support for a mechanism based on synthesis, diffusion, and degradation. PMID:22004733

Analysis of Rotary Aircraft Alternatives for NATO SOF Organic Air Wing

DTIC Science & Technology

2012-06-01

analysis with an assumed program start in 2013 and an end in 2019 to determine the impact of short program duration on platform selection. D...FY12 GO\\ LR,~itl\\ l Sli LABOR H13 (J()VI R\\\\iFI\\TSE I AROR FY14 GOVLR\\\\iLI\\ I Sl:. LABOR H15 SI:.PO CSS FY II SII’O CSS FY 12 SEI’() CSS fY 13

Group protocol to mitigate disaster stress and enhance social support in adolescents exposed to Hurricane Hugo.

PubMed

Stewart, J B; Hardin, S B; Weinrich, S; McGeorge, S; Lopez, J; Pesut, D

1992-01-01

Literature reports that cognitive understanding and social support can mitigate stress in both adults and adolescents. As a subcomponent of the Carolina Adolescent Health Project (CAHP), this research evaluated the efficacy of a Cognitive Social Support (CSS) group protocol designed to mitigate the disaster stress of adolescents who had been exposed seriously to Hurricane Hugo. A purposive sample of 259 students participated in and evaluated the CSS. This article reports the specific structure, content, process, rationale, and cost of the CSS. Evaluations indicated that 82% of the students evaluated the small-group component of the CSS as "very good" or "excellent," while 70% rated the large-group component as "very good" or "excellent."

Steady-state solution of the semi-empirical diffusion equation for area sources. [air pollution studies

NASA Technical Reports Server (NTRS)

Lebedeff, S. A.; Hameed, S.

1975-01-01

The problem investigated can be solved exactly in a simple manner if the equations are written in terms of a similarity variable. The exact solution is used to explore two questions of interest in the modelling of urban air pollution, taking into account the distribution of surface concentration downwind of an area source and the distribution of concentration with height.

Mimicking Nonequilibrium Steady States with Time-Periodic Driving (Open Source)

DTIC Science & Technology

2016-05-18

nonequilibrium steady states, and vice versa, within the theoretical framework of discrete-state stochastic thermodynamics . Nonequilibrium steady states...equilibrium [2], spontaneous relaxation towards equilibrium [3], nonequilibrium steady states generated by fixed thermodynamic forces [4], and stochastic pumps...paradigm, a system driven by fixed thermodynamic forces—such as temperature gradients or chemical potential differences— reaches a steady state in

Glucans monomer-exchange dynamics as an open chemical network

NASA Astrophysics Data System (ADS)

Rao, Riccardo; Lacoste, David; Esposito, Massimiliano

2015-12-01

We describe the oligosaccharides-exchange dynamics performed by the so-called D-enzymes on polysaccharides. To mimic physiological conditions, we treat this process as an open chemical network by assuming some of the polymer concentrations fixed (chemostatting). We show that three different long-time behaviors may ensue: equilibrium states, nonequilibrium steady states, and continuous growth states. We dynamically and thermodynamically characterize these states and emphasize the crucial role of conservation laws in identifying the chemostatting conditions inducing them.

Glucans monomer-exchange dynamics as an open chemical network

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rao, Riccardo, E-mail: riccardo.rao@uni.lu; Esposito, Massimiliano, E-mail: massimiliano.esposito@uni.lu; Lacoste, David

2015-12-28

We describe the oligosaccharides-exchange dynamics performed by the so-called D-enzymes on polysaccharides. To mimic physiological conditions, we treat this process as an open chemical network by assuming some of the polymer concentrations fixed (chemostatting). We show that three different long-time behaviors may ensue: equilibrium states, nonequilibrium steady states, and continuous growth states. We dynamically and thermodynamically characterize these states and emphasize the crucial role of conservation laws in identifying the chemostatting conditions inducing them.

Development of biomass in a drinking water granular active carbon (GAC) filter.

PubMed

Velten, Silvana; Boller, Markus; Köster, Oliver; Helbing, Jakob; Weilenmann, Hans-Ulrich; Hammes, Frederik

2011-12-01

Indigenous bacteria are essential for the performance of drinking water biofilters, yet this biological component remains poorly characterized. In the present study we followed biofilm formation and development in a granular activated carbon (GAC) filter on pilot-scale during the first six months of operation. GAC particles were sampled from four different depths (10, 45, 80 and 115 cm) and attached biomass was measured with adenosine tri-phosphate (ATP) analysis. The attached biomass accumulated rapidly on the GAC particles throughout all levels in the filter during the first 90 days of operation and maintained a steady state afterward. Vertical gradients of biomass density and growth rates were observed during start-up and also in steady state. During steady state, biomass concentrations ranged between 0.8-1.83 x 10(-6) g ATP/g GAC in the filter, and 22% of the influent dissolved organic carbon (DOC) was removed. Concomitant biomass production was about 1.8 × 10(12) cells/m(2)h, which represents a yield of 1.26 × 10(6) cells/μg. The bacteria assimilated only about 3% of the removed carbon as biomass. At one point during the operational period, a natural 5-fold increase in the influent phytoplankton concentration occurred. As a result, influent assimilable organic carbon concentrations increased and suspended bacteria in the filter effluent increased 3-fold as the direct consequence of increased growth in the biofilter. This study shows that the combination of different analytical methods allows detailed quantification of the microbiological activity in drinking water biofilters. Copyright © 2011 Elsevier Ltd. All rights reserved.

In vivo determination of steric and electrostatic exclusion of albumin in rat skin and skeletal muscle

PubMed Central

Gyenge, Christina C; Tenstad, Olav; Wiig, Helge

2003-01-01

In order to estimate the magnitude of electrostatic exclusion provided by the fixed negative charges of the skin and muscle interstitia of rat in vivo we measured the distribution volumes of two differently charged albumin probes within these tissues. An implanted osmotic pump was used to reach and maintain a steady-state extracellular concentration of a mixture containing two iodine-labelled probes: a charged-modified human serum albumin, cHSA (i.e. a positive probe, isoelectirc point (pI) = 7.6) and a native human serum albumin, HSA (i.e. a normally charged, negative probe, pI = 5.0). Steady-state tissue concentrations were achieved after intravenous infusion of probes for 5–7 days. At the end of this period the animals were nephrectomized and a bolus of 51Cr-EDTA was administered for estimating the extracellular volume. Plasma volumes were measured as 5-min distribution volume of 125I-HSA in separate experiments. The steady-state interstitial fluid concentrations of all probes were determined using nylon wicks implanted postmortem. Calculations of labelled probes were made for interstitial fluid volumes (Vi), extravascular albumin distribution volumes (Vav,a) and relative interstitial excluded volume fractions (Vex,a/Vi). We found that the positive probe is excluded from a significantly smaller fraction of the interstitium. Specifically, the average relative albumin exclusion fractions obtained were: 16% and 26% in skeletal muscle and 30% and 40% in skin, for cHSA and HSA, respectively. On average, the fixed negative charges of the interstitium are responsible for about 40% of the total albumin exclusion in skeletal muscle and 25% in the whole skin tissue and thus, contribute significantly to volume exclusion in these tissues. PMID:12937287

In vivo determination of steric and electrostatic exclusion of albumin in rat skin and skeletal muscle.

PubMed

Gyenge, Christina C; Tenstad, Olav; Wiig, Helge

2003-11-01

In order to estimate the magnitude of electrostatic exclusion provided by the fixed negative charges of the skin and muscle interstitia of rat in vivo we measured the distribution volumes of two differently charged albumin probes within these tissues. An implanted osmotic pump was used to reach and maintain a steady-state extracellular concentration of a mixture containing two iodine-labelled probes: a charged-modified human serum albumin, cHSA (i.e. a positive probe, isoelectirc point (pI) = 7.6) and a native human serum albumin, HSA (i.e. a normally charged, negative probe, pI = 5.0). Steady-state tissue concentrations were achieved after intravenous infusion of probes for 5-7 days. At the end of this period the animals were nephrectomized and a bolus of 51Cr-EDTA was administered for estimating the extracellular volume. Plasma volumes were measured as 5-min distribution volume of 125I-HSA in separate experiments. The steady-state interstitial fluid concentrations of all probes were determined using nylon wicks implanted postmortem. Calculations of labelled probes were made for interstitial fluid volumes (Vi), extravascular albumin distribution volumes (Vav,a) and relative interstitial excluded volume fractions (Vex,a/Vi). We found that the positive probe is excluded from a significantly smaller fraction of the interstitium. Specifically, the average relative albumin exclusion fractions obtained were: 16% and 26% in skeletal muscle and 30% and 40% in skin, for cHSA and HSA, respectively. On average, the fixed negative charges of the interstitium are responsible for about 40% of the total albumin exclusion in skeletal muscle and 25% in the whole skin tissue and thus, contribute significantly to volume exclusion in these tissues.

The metabolic clearance of progesterone in the pregnant rat: Absence of a physiological role for the lung

DOE Office of Scientific and Technical Information (OSTI.GOV)

Waddell, B.J.; Bruce, N.W.

1989-06-01

The metabolic clearance rate (MCR) of progesterone is among the highest for all steroid hormones studied, yet it is difficult to apportion this high MCR to specific organ contributions. The isolated lung has been shown to metabolize progesterone, and since this tissue receives the entire cardiac output, potentially it could make a major contribution to the overall MCR. This possibility was examined in the present study by measuring lung extraction of (3H)progesterone under steady-state conditions in the intact pregnant rat. Anesthetized rats (n = 6) were infused with (3H)progesterone via a femoral vein for 100 min on Day 16 ofmore » pregnancy. After the onset of steady state (40 min), four blood samples were obtained at 20-min intervals from the right ventricle and from the aorta, and the concentrations of (3H)progesterone and its metabolites were determined. Throughout the sampling period, mean arterial pressure and heart rate remained stable (two-way analysis of variance), as did the production rate (3.76 +/- 0.35 mg/day; mean +/- SEM) and the MCR (34.8 +/- 3.5 ml/min) of progesterone. Despite this high rate of clearance, there was no difference between the concentration of (3H)progesterone in arterial and right ventricular blood, indicating no net extraction of progesterone during passage through the lung. Furthermore, there was no change in the concentration of either lipid-soluble or aqueous-soluble (3H)progesterone metabolites during trans-lung passage. These observations demonstrate that the lung does not contribute to the MCR of progesterone when measured under physiological and steady-state conditions. Therefore, the relationship, MCR (ml/min) = whole-body extraction (%) x cardiac output (ml/min), is upheld for progesterone in the rat.« less

Synthesis of [Zn-Al-CO 3] layered double hydroxides by a coprecipitation method under steady-state conditions

NASA Astrophysics Data System (ADS)

Chang, Z.; Evans, D. G.; Duan, X.; Vial, C.; Ghanbaja, J.; Prevot, V.; de Roy, M.; Forano, C.

2005-09-01

A continuous co-precipitation method under steady-state conditions has been investigated for the preparation of nanometer-size layered double hydroxide (LDH) particles using Zn 2Al(OH) 6(CO 3) 0.5·2H 2O as a prototype. The objective was to shorten the preparation time by working without an aging step, using a short and controlled residence time in order to maintain a constant supersaturation level in the reactor and constant particle properties in the exit stream over time. The effects of varying the operating conditions on the structural and textural properties of the LDHs have been studied, including total cation concentration, solvent, residence time, pH and intercalation anion. The products have been characterized using ICP, XRD, FTIR, BET, SEM and TEM. The LDHs prepared by the continuous coprecipitation method have a poorer crystallinity and lower crystallite sizes than those synthesized by the conventional batch method. The results have shown that increasing either cation concentration or the fraction of monoethylene glycol (MEG) in MEG/H 2O mixtures up to 80% (v/v) affect salt solubility and supersaturation, which gives rise to smaller crystallites, larger surface areas and more amorphous compounds. This increase is however limited by the precipitation of zinc and aluminum hydroxides occurring around a total cation concentration of 3.0×10 -1 M in pure water and 3.0×10 -2 M in H 2O/EtOH mixtures. Crystallite size increases with residence time, suggesting a precipitation process controlled by growth. Finally, the continuous coprecipitation method under steady-state conditions has been shown to be a promising alternative to the traditional coprecipitation technique in either pure water or mixed H 2O/MEG solvents.

Kinetics of dissolution of UO2 in nitric acid solutions: A multiparametric study of the non-catalysed reaction

NASA Astrophysics Data System (ADS)

Cordara, T.; Szenknect, S.; Claparede, L.; Podor, R.; Mesbah, A.; Lavalette, C.; Dacheux, N.

2017-12-01

UO2 pellets were prepared by densification of oxides obtained from the conversion of the oxalate precursor. Then characterized in order to perform a multiparametric study of the dissolution in nitric acid medium. In this frame, for each sample, the densification rate, the grain size and the specific surface area of the prepared pellets were determined prior to the final dissolution experiments. By varying the concentration of the nitric acid solution and temperature, three different and successive steps were identified during the dissolution. Under the less aggressive conditions considered, a first transient step corresponding to the dissolution of the most reactive phases was observed at the solid/solution interface. Then, for all the tested conditions, a steady state step was established during which the normalised dissolution rate was found to be constant. It was followed by a third step characterized by a strong and continuous increase of the normalised dissolution rate. The duration of the steady state, also called "induction period", was found to vary drastically as a function of the HNO3 concentration and temperature. However, independently of the conditions, this steady state step stopped at almost similar dissolved material weight loss and dissolved uranium concentration. During the induction period, no important evolution of the topology of the solid/liquid interface was evidenced authorizing the use of the starting reactive specific surface area to evaluate the normalised dissolution rates thus the chemical durability of the sintered pellets. From the multiparametric study of UO2 dissolution proposed, oxidation of U(IV) to U(VI) by nitrate ions at the solid/liquid interface constitutes the limiting step in the overall dissolution mechanism associated to this induction period.

A Pharmacokinetic Study of an Ibuprofen Topical Patch in Healthy Male and Female Adult Volunteers.

PubMed

Lewis, Fraser; Connolly, Mark P; Bhatt, Aomesh

2018-01-11

The pharmacokinetics of a novel locally applied ibuprofen topical patch was evaluated. Healthy subjects (n = 28) were administered a 200-mg ibuprofen patch every 24 hours for 5 days, and steady-state pharmacokinetics was determined. The amount of ibuprofen remaining in the patch following each patch removal was also assessed. The maximum steady-state drug concentration and area under the concentration curve from time 0 on day 5 (t = 0) to the 24-hours sample on day 6 were 514 ng/mL (95% CI 439 to 603 ng/mL) and 9.78 kg·h/mL (95% CI 8.43 to 11.4 kg·h/mL), respectively. Maximum ibuprofen concentration on day 5 occurred at 20 hours post-patch application. No evidence of drug accumulation was observed, and steady state was achieved between days 2 and 5. Ibuprofen levels attenuated rapidly to baseline within 24 hours after treatment discontinuation. The amount of ibuprofen remaining in the patch was high (≥80%). Treatment-emergent adverse events were generally mild, with the most prevalent being headache (n = 6; 21.4%). Only 4 TEAEs were considered related to the ibuprofen patch: paresthesia (n = 1), headache (n = 2), and pruritic rash (n = 1). The study found that the systematic absorption of ibuprofen from a 200-mg patch was low and that the levels of ibuprofen leaving the patch over a 24-hour period are consistent with levels required for therapeutic relief as shown in other studies. © 2018, The American College of Clinical Pharmacology.

High-Throughput Predictive Approaches to Evaluating Chemicals in Food Contact Materials: Migration, Exposure, and Alternatives Identification

EPA Science Inventory

This is a presentation describing CSS research on HT predictive methods to modeling exposure and predicting functional substitutes. It will be presented at a forum co-sponsored by the State of California and UC Berekeley on evaluation of chemical alternatives for food contact ch...

A system of equations to approximate the pharmacokinetic parameters of lacosamide at steady state from one plasma sample.

PubMed

Cawello, Willi; Schäfer, Carina

2014-08-01

Frequent plasma sampling to monitor pharmacokinetic (PK) profile of antiepileptic drugs (AEDs), is invasive, costly and time consuming. For drugs with a well-defined PK profile, such as AED lacosamide, equations can accurately approximate PK parameters from one steady-state plasma sample. Equations were derived to approximate steady-state peak and trough lacosamide plasma concentrations (Cpeak,ss and Ctrough,ss, respectively) and area under concentration-time curve during dosing interval (AUCτ,ss) from one plasma sample. Lacosamide (ka: ∼2 h(-1); ke: ∼0.05 h(-1), corresponding to half-life of 13 h) was calculated to reach Cpeak,ss after ∼1 h (tmax,ss). Equations were validated by comparing approximations to reference PK parameters obtained from single plasma samples drawn 3-12h following lacosamide administration, using data from double-blind, placebo-controlled, parallel-group PK study. Values of relative bias (accuracy) between -15% and +15%, and root mean square error (RMSE) values≤15% (precision) were considered acceptable for validation. Thirty-five healthy subjects (12 young males; 11 elderly males, 12 elderly females) received lacosamide 100mg/day for 4.5 days. Equation-derived PK values were compared to reference mean Cpeak,ss, Ctrough,ss and AUCτ,ss values. Equation-derived PK data had a precision of 6.2% and accuracy of -8.0%, 2.9%, and -0.11%, respectively. Equation-derived versus reference PK values for individual samples obtained 3-12h after lacosamide administration showed correlation (R2) range of 0.88-0.97 for AUCτ,ss. Correlation range for Cpeak,ss and Ctrough,ss was 0.65-0.87. Error analyses for individual sample comparisons were independent of time. Derived equations approximated lacosamide Cpeak,ss, Ctrough,ss and AUCτ,ss using one steady-state plasma sample within validation range. Approximated PK parameters were within accepted validation criteria when compared to reference PK values. Copyright © 2014 Elsevier B.V. All rights reserved.

Osmosis in Cortical Collecting Tubules

PubMed Central

Schafer, James A.; Patlak, Clifford S.; Andreoli, Thomas E.

1974-01-01

This paper reports a theoretical analysis of osmotic transients and an experimental evaluation both of rapid time resolution of lumen to bath osmosis and of bidirectional steady-state osmosis in isolated rabbit cortical collecting tubules exposed to antidiuretic hormone (ADH). For the case of a membrane in series with unstirred layers, there may be considerable differences between initial and steady-state osmotic flows (i.e., the osmotic transient phenomenon), because the solute concentrations at the interfaces between membrane and unstirred layers may vary with time. A numerical solution of the equation of continuity provided a means for computing these time-dependent values, and, accordingly, the variation of osmotic flow with time for a given set of parameters including: Pf (cm s–1), the osmotic water permeability coefficient, the bulk phase solute concentrations, the unstirred layer thickness on either side of the membrane, and the fractional areas available for volume flow in the unstirred layers. The analyses provide a quantitative frame of reference for evaluating osmotic transients observed in epithelia in series with asymmetrical unstirred layers and indicate that, for such epithelia, Pf determinations from steady-state osmotic flows may result in gross underestimates of osmotic water permeability. In earlier studies, we suggested that the discrepancy between the ADH-dependent values of Pf and PDDw (cm s–1, diffusional water permeability coefficient) was the consequence of cellular constraints to diffusion. In the present experiments, no transients were detectable 20–30 s after initiating ADH-dependent lumen to bath osmosis; and steady-state ADH-dependent osmotic flows from bath to lumen and lumen to bath were linear and symmetrical. An evaluation of these data in terms of the analytical model indicates: First, cellular constraints to diffusion in cortical collecting tubules could be rationalized in terms of a 25-fold reduction in the area of the cell layer available for water transport, possibly due in part to transcellular shunting of osmotic flow; and second, such cellular constraints resulted in relatively small, approximately 15%, underestimates of Pf. PMID:4846767

Design and Performance of the Sorbent-Based Atmosphere Revitalization System for Orion

NASA Technical Reports Server (NTRS)

Ritter, James A.; Reynolds, Steven P.; Ebner, Armin D.; Knox, James C.; LeVan, M. Douglas

2007-01-01

Validation and simulations of a real-time dynamic cabin model were conducted on the sorbent-based atmosphere revitalization system for Orion. The dynamic cabin model, which updates the concentration of H2O and CO2 every second during the simulation, was able to predict the steady state model values for H2O and CO2 for long periods of steady metabolic production for a 4-person crew. It also showed similar trends for the exercise periods, where there were quick changes in production rates. Once validated, the cabin model was used to determine the effects of feed flow rate, cabin volume and column volume. A higher feed flow rate reduced the cabin concentrations only slightly over the base case, a larger cabin volume was able to reduce the cabin concentrations even further, and the lower column volume led to much higher cabin concentrations. Finally, the cabin model was used to determine the effect of the amount of silica gel in the column. As the amount increased, the cabin concentration of H2O decreased, but the cabin concentration of CO2 increased.

Reciprocal responsiveness of nucleus accumbens shell and core dopamine to food- and drug-conditioned stimuli.

PubMed

Bassareo, Valentina; Musio, Paolo; Di Chiara, Gaetano

2011-04-01

Drugs of abuse and palatable food share the ability to stimulate dopamine (DA) transmission in the nucleus accumbens shell. However, while the stimulation of shell DA by food undergoes habituation, that by drugs of abuse does not. This study aims to directly compare the changes of extracellular DA, by microdialysis, in shell and core and prefrontal cortex (PFCX) in response to food- and drug-conditioned stimuli (CSs). Rats were trace-conditioned by Fonzies box (FB) or vanilla box (VB; CS), followed by food: Fonzies, intraoral chocolate solution (food-unconditioned stimulus (US)) and morphine (1.0 mg/Kg sc; drug US). Control (unconditioned) rats received standard food instead of Fonzies, tap water instead of chocolate, saline instead of morphine. Food-CSs increased core but not shell DA, while drug-CSs did the opposite. Food and drug-CSs both increased PFCX DA. Exposure to food-CSs potentiated core and PFCX DA response to food while shell responsiveness was dependent upon the relative CS and US nature. If the CS was intrinsic to the food US (CS = FB/US = Fonzies) the response of shell DA to the US was abolished. If the CS was extrinsic to the food US (CS = FB/US = chocolate; CS = VB/US = Fonzies), shell DA increased in response to the US. Exposure to the drug-CS potentiated the DA response to the drug-US in the shell and in the PFCX, but not in the core. Drug-CSs differentially activate DA as compared to food-CSs in shell and core and differentially affect DA response to the US in these areas. These differences might be relevant for the role of DA in the mechanism of drug addiction.

Unsafe from the Start: Serious Misuse of Car Safety Seats at Newborn Discharge.

PubMed

Hoffman, Benjamin D; Gallardo, Adrienne R; Carlson, Kathleen F

2016-04-01

To estimate prevalence of car safety seat (CSS) misuse for newborns on hospital discharge; and to identify potential risk and protective factors for CSS misuse. We randomly sampled 291 mother-baby dyads from the newborn unit of an academic health center. Participants completed a survey and designated someone (themselves or another caregiver) to position their newborn in the CSS and install the CSS in their vehicle. Certified child passenger safety technicians assessed positioning and installation using nationally standardized criteria. To examine factors associated with CSS misuse, we used logistic regression to compute ORs and 95% CIs. A total of 291 families (81% of those eligible) participated. Nearly all (95%) CSSs were misused, with 1 or more errors in positioning (86%) and/or installation (77%). Serious CSS misuse occurred for 91% of all infants. Frequent misuses included harness and chest clip errors, incorrect recline angle, and seat belt/lower anchor use errors. Families with mothers of color (OR, 6.3; 95% CI, 1.8-21.6), non-English language (OR, 4.9; 95% CI, 1.1-21.2), Medicaid (OR, 10.3; 95% CI, 2.4-44.4), or lower educational level (OR, 4.5; 95% CI, 1.7-12.4) were more likely to misuse CSSs. However, families that worked with a child passenger safety technician before delivery were significantly less likely to misuse their CSSs (OR, 0.1; 95% CI, 0.0-0.4). Nearly all parents of newborn infants misused CSSs. Resources should be devoted to ensuring families with newborns leave the hospital correctly using their CSS. Copyright © 2016 Elsevier Inc. All rights reserved.

Germline BRCA mutations are associated with higher risk of nodal involvement, distant metastasis, and poor survival outcomes in prostate cancer.

PubMed

Castro, Elena; Goh, Chee; Olmos, David; Saunders, Ed; Leongamornlert, Daniel; Tymrakiewicz, Malgorzata; Mahmud, Nadiya; Dadaev, Tokhir; Govindasami, Koveela; Guy, Michelle; Sawyer, Emma; Wilkinson, Rosemary; Ardern-Jones, Audrey; Ellis, Steve; Frost, Debra; Peock, Susan; Evans, D Gareth; Tischkowitz, Marc; Cole, Trevor; Davidson, Rosemarie; Eccles, Diana; Brewer, Carole; Douglas, Fiona; Porteous, Mary E; Donaldson, Alan; Dorkins, Huw; Izatt, Louise; Cook, Jackie; Hodgson, Shirley; Kennedy, M John; Side, Lucy E; Eason, Jacqueline; Murray, Alex; Antoniou, Antonis C; Easton, Douglas F; Kote-Jarai, Zsofia; Eeles, Rosalind

2013-05-10

To analyze the baseline clinicopathologic characteristics of prostate tumors with germline BRCA1 and BRCA2 (BRCA1/2) mutations and the prognostic value of those mutations on prostate cancer (PCa) outcomes. This study analyzed the tumor features and outcomes of 2,019 patients with PCa (18 BRCA1 carriers, 61 BRCA2 carriers, and 1,940 noncarriers). The Kaplan-Meier method and Cox regression analysis were used to evaluate the associations between BRCA1/2 status and other PCa prognostic factors with overall survival (OS), cause-specific OS (CSS), CSS in localized PCa (CSS_M0), metastasis-free survival (MFS), and CSS from metastasis (CSS_M1). PCa with germline BRCA1/2 mutations were more frequently associated with Gleason ≥ 8 (P = .00003), T3/T4 stage (P = .003), nodal involvement (P = .00005), and metastases at diagnosis (P = .005) than PCa in noncarriers. CSS was significantly longer in noncarriers than in carriers (15.7 v 8.6 years, multivariable analyses [MVA] P = .015; hazard ratio [HR] = 1.8). For localized PCa, 5-year CSS and MFS were significantly higher in noncarriers (96% v 82%; MVA P = .01; HR = 2.6%; and 93% v 77%; MVA P = .009; HR = 2.7, respectively). Subgroup analyses confirmed the poor outcomes in BRCA2 patients, whereas the role of BRCA1 was not well defined due to the limited size and follow-up in this subgroup. Our results confirm that BRCA1/2 mutations confer a more aggressive PCa phenotype with a higher probability of nodal involvement and distant metastasis. BRCA mutations are associated with poor survival outcomes and this should be considered for tailoring clinical management of these patients.

Coal slurry solids/coal fluidized bed combustion by-product mixtures as plant growth media

USGS Publications Warehouse

Darmody, R.G.; Green, W.P.; Dreher, G.B.

1998-01-01

Fine-textured, pyritic waste produced by coal cleaning is stored in slurry settling ponds that eventually require reclamation. Conventionally, reclamation involves covering the dewatered coal slurry solids (CSS) with 1.3 m of soil to allow plant growth and prevent acid generation by pyrite oxidation. This study was conducted to determine the feasiblity of a less costly reclamation approach that would eliminate the soil cover and allow direct seeding of plants into amended CSS materials. Potential acidity of the CSS would be neutralized by additions of fluidized-bed combustion by-product (FBCB), an alkaline by-product of coal combustion. The experiment involved two sources of CSS and FBCB materials from Illinois. Birdsfoot trefoil (Lotus corniculatus L.), tall fescue (Festuca arundinacea Schreb.), and sweet clover (Melilotus officinalis (L.) Lam.) were seeded in the greenhouse into pots containing mixtures of the materials. CSS-1 had a high CaCO3:FeS2 ratio and needed no FBCB added to compensate for its potential acidity. CSS-2 was mixed with the FBCB materials to neutralize potential acidity (labeled Mix A and B). Initial pH was 5.6, 8.8, and 9.2 for the CSS-1, Mix A, and Mix B materials, respectively. At the end of the 70-day experiment, pH was 5.9 for all mixtures. Tall fescue and sweet clover grew well in all the treatments, but birdsfoot trefoil had poor emergence and survival. Elevated tissue levels of B, Cd, and Se were found in some plants. Salinity, low moisture holding capacity, and potentially phytotoxic B may limit the efficacy of this reclamation method.

A nomogram to predict prognostic values of various inflammatory biomarkers in patients with esophageal squamous cell carcinoma

PubMed Central

Liu, Jin-Shi; Huang, Ying; Yang, Xun; Feng, Ji-Feng

2015-01-01

Background: Inflammation plays an important role in cancer progression and prognosis. However, the prognostic values of inflammatory biomarkers in esophageal cancer (EC) were not established. In the present study, therefore, we initially used a nomogram to predict prognostic values of various inflammatory biomarkers in patients with esophageal squamous cell carcinoma (ESCC). Methods: A total of 326 ESCC patients were included in this retrospective study. Glasgow prognostic score (GPS), neutrophil lymphocyte ratio (NLR), platelet lymphocyte ratio (PLR) and lymphocyte monocyte ratio (LMR) were analyzed in the current study. Kaplan-Meier method was used to calculate the cancer-specific survival (CSS). Cox regression analysis was also performed to evaluate the prognostic factors. A nomogram was established to predict the prognosis for CSS. Results: Patients were divided into 3 groups according to GPS (GPS 0, 1 and 2) and 2 groups according to NLR (≤3.45 and >3.45), PLR (≤166.5 and >166.5) and LMR (≤2.30 and >2.30). The 5-year CSS in patients with GPS 0, 1 and 2 were 49.2%, 26.8% and 11.9%, respectively (P<0.001). In addition, patients with NLR (>3.45), PLR (>166.5) and LMR (≤2.30) were significantly associated with decreased CSS, respectively (P<0.001). Multivariate analysis revealed that GPS (P<0.001), PLR (P=0.002) and LMR (P=0.002) were independent prognostic factors in patients with ESCC. In addition, a nomogram was established according to all significantly independent factors for CSS. The Harrell’s c-index for CSS prediction was 0.72. Conclusion: GPS, PLR and LMR were potential prognostic biomarkers in patients with ESCC. The nomogram based on CSS could be used as an accurately prognostic prediction for patients with ESCC. PMID:26328248

Germline BRCA Mutations Are Associated With Higher Risk of Nodal Involvement, Distant Metastasis, and Poor Survival Outcomes in Prostate Cancer

PubMed Central

Castro, Elena; Goh, Chee; Olmos, David; Saunders, Ed; Leongamornlert, Daniel; Tymrakiewicz, Malgorzata; Mahmud, Nadiya; Dadaev, Tokhir; Govindasami, Koveela; Guy, Michelle; Sawyer, Emma; Wilkinson, Rosemary; Ardern-Jones, Audrey; Ellis, Steve; Frost, Debra; Peock, Susan; Evans, D. Gareth; Tischkowitz, Marc; Cole, Trevor; Davidson, Rosemarie; Eccles, Diana; Brewer, Carole; Douglas, Fiona; Porteous, Mary E.; Donaldson, Alan; Dorkins, Huw; Izatt, Louise; Cook, Jackie; Hodgson, Shirley; Kennedy, M. John; Side, Lucy E.; Eason, Jacqueline; Murray, Alex; Antoniou, Antonis C.; Easton, Douglas F.; Kote-Jarai, Zsofia; Eeles, Rosalind

2013-01-01

Purpose To analyze the baseline clinicopathologic characteristics of prostate tumors with germline BRCA1 and BRCA2 (BRCA1/2) mutations and the prognostic value of those mutations on prostate cancer (PCa) outcomes. Patients and Methods This study analyzed the tumor features and outcomes of 2,019 patients with PCa (18 BRCA1 carriers, 61 BRCA2 carriers, and 1,940 noncarriers). The Kaplan-Meier method and Cox regression analysis were used to evaluate the associations between BRCA1/2 status and other PCa prognostic factors with overall survival (OS), cause-specific OS (CSS), CSS in localized PCa (CSS_M0), metastasis-free survival (MFS), and CSS from metastasis (CSS_M1). Results PCa with germline BRCA1/2 mutations were more frequently associated with Gleason ≥ 8 (P = .00003), T3/T4 stage (P = .003), nodal involvement (P = .00005), and metastases at diagnosis (P = .005) than PCa in noncarriers. CSS was significantly longer in noncarriers than in carriers (15.7 v 8.6 years, multivariable analyses [MVA] P = .015; hazard ratio [HR] = 1.8). For localized PCa, 5-year CSS and MFS were significantly higher in noncarriers (96% v 82%; MVA P = .01; HR = 2.6%; and 93% v 77%; MVA P = .009; HR = 2.7, respectively). Subgroup analyses confirmed the poor outcomes in BRCA2 patients, whereas the role of BRCA1 was not well defined due to the limited size and follow-up in this subgroup. Conclusion Our results confirm that BRCA1/2 mutations confer a more aggressive PCa phenotype with a higher probability of nodal involvement and distant metastasis. BRCA mutations are associated with poor survival outcomes and this should be considered for tailoring clinical management of these patients. PMID:23569316

Brief Report: Relationship Between ADOS-2, Module 4 Calibrated Severity Scores (CSS) and Social and Non-Social Standardized Assessment Measures in Adult Males with Autism Spectrum Disorder (ASD)

ERIC Educational Resources Information Center

Morrier, Michael J.; Ousley, Opal Y.; Caceres-Gamundi, Gabriella A.; Segall, Matthew J.; Cubells, Joseph F.; Young, Larry J.; Andari, Elissar

2017-01-01

The ADOS-2 Modules 1-3 now include a standardized calibrated severity score (CSS) from 1 to 10 based on the overall total raw score. Subsequent research published CSS for Module 4 (Hus, Lord, "Journal of Autism and Developmental Disorders" 44(8):1996-2012, 2014); however more research is needed to examine the psychometric properties of…

Adult smokers' responses to "corrective statements" regarding tobacco industry deception.

PubMed

Kollath-Cattano, Christy L; Abad-Vivero, Erika N; Thrasher, James F; Bansal-Travers, Maansi; O'Connor, Richard J; Krugman, Dean M; Berg, Carla J; Hardin, James W

2014-07-01

To inform consumers, U.S. Federal Courts have ordered the tobacco industry to disseminate "corrective statements" (CSs) about their deception regarding five topics: smoker health effects, nonsmoker health effects, cigarette addictiveness, design of cigarettes to increase addiction, and relative safety of light cigarettes. To determine how smokers from diverse backgrounds respond to the final, court-mandated wording of these CSs. Data were analyzed from an online consumer panel of 1,404 adult smokers who evaluated one of five CS topics (n=280-281) by reporting novelty, relevance, anger at the industry, and motivation to quit because of the CS. Logistic and linear regression models assessed main and interactive effects of race/ethnicity, gender, education, and CS topic on these responses. Data were collected in January 2013 and analyzed in March 2013. Thirty percent to 54% of participants reported that each CS provided novel information, and novelty was associated with greater relevance, anger at the industry, and motivation to quit because of the message. African Americans and Latinos were more likely than non-Hispanic whites to report that CSs were novel, and they had stronger responses to CSs across all indicators. Compared to men, women reported that CSs were more relevant and motivated them to quit. This study suggests that smokers would value and respond to CSs, particularly smokers from groups that suffer from tobacco-related health disparities. Copyright © 2014. Published by Elsevier Inc.

Environmental odor intolerance in pregnant women.

PubMed

Nordin, Steven; Broman, Daniel A; Wulff, Marianne

2005-02-15

Previous findings indicating that pregnant women experience a shift in odor sensitivity and hedonics raise the question of whether these changes evoke adverse reactions to odorous and pungent environmental substances in daily activities, to a larger extent in pregnant than in nonpregnant women. Forty-four women in pregnancy weeks 21-23 and 44 nonpregnant women were therefore compared with respect to affective reactions to and behavioral disruptions by odorous/pungent daily environments by means of the questionnaire-based, 21-item Chemical Sensitivity Scale (CSS). This scale refers to neurasthenic and sensory/somatic symptoms and includes the 11 items of the Chemical Sensitivity Scale for Sensory Hyperreactivity (CSS-SHR). This latter scale refers predominantly to sensory/somatic symptoms. To investigate whether there is a general environmental hypersensitivity during pregnancy, the Noise Sensitivity Scale (NSS) was used that is analogous to the CSS (including 11 NSS items corresponding to those of the CSS-SHR; "NSS-SHR"). Results show that the two groups were similar with respect to scores on both the CSS and NSS, whereas the pregnant women had higher scores than the nonpregnant women on the CSS-SHR, but not on the "NSS-SHR". These results suggest that pregnant women to a larger extent than nonpregnant women manifest an odor intolerance that affects their daily activities, with predominantly sensory/somatic symptoms, which appears not to be due to a general environmental hypersensitivity. This behavior may have embryo- and maternal-protective functions.

Adult Smokers' Responses to “Corrective Statements” Regarding Tobacco Industry Deception

PubMed Central

Kollath-Cattano, Christy L.; Abad-Vivero, Erika N.; Thrasher, James F.; Bansal-Travers, Maansi; O'Connor, Richard J.; Krugman, Dean M.; Berg, Carla J.; Hardin, James W.

2014-01-01

Background To inform consumers, U.S. Federal Courts have ordered the tobacco industry to disseminate “corrective statements” (CSs) about their deception regarding five topics: smoker health effects, nonsmoker health effects, cigarette addictiveness, design of cigarettes to increase addiction, and relative safety of light cigarettes. Purpose To determine how smokers from diverse backgrounds respond to the final, court-mandated wording of these CSs. Methods Data were analyzed from an online consumer panel of 1,404 adult smokers who evaluated one of five CS topics (n=280–281) by reporting novelty, relevance, anger at the industry, and motivation to quit because of the CS. Logistic and linear regression models assessed main and interactive effects of race/ethnicity, gender, education, and CS topic on these responses. Data were collected in January 2013 and analyzed in March 2013. Results Thirty percent to 54% of participants reported that each CS provided novel information, and novelty was associated with greater relevance, anger at the industry, and motivation to quit because of the message. African Americans and Latinos were more likely than non-Hispanic whites to report that CSs were novel, and they had stronger responses to CSs across all indicators. Compared to men, women reported that CSs were more relevant and motivated them to quit. Conclusions This study suggests that smokers would value and respond to CSs, particularly smokers from groups that suffer from tobacco–related health disparities. PMID:24746372

Clinical features and prognostic factors of Churg-Strauss syndrome.

PubMed

Kim, Mi-Yeong; Sohn, Kyoung-Hee; Song, Woo-Jung; Park, Heung-Woo; Cho, Sang-Heon; Min, Kyung-Up; Kang, Hye-Ryun

2014-01-01

Churg-Strauss syndrome (CSS) is a rare systemic necrotizing small-vessel vasculitis, with accompanying bronchial asthma, eosinophilia, and eosinophilic infiltration of various tissues. The purposes of our study were to characterize the clinical features of CSS and to identify factors associated with CSS prognosis in Koreans. Medical records were reviewed retrospectively for all physician-diagnosed CSS patients in the Seoul National University Hospital between January 1990 and March 2011. Data from 52 CSS patients were analyzed. The respiratory tract was the most commonly involved organ (90.4%). Renal involvement was less frequent in antineutrophilic cytoplasmic antibody (ANCA)(-) patients than in ANCA(+) patients (p = 0.048). Clinical remission occurred in 95.3% of patients, but 16.3% of them relapsed. Patients who maintained remission for more than 6 months were relatively older (median, 51 years) at diagnosis (p = 0.004), had been diagnosed in earlier stages (p = 0.027), showed more frequent respiratory involvement (p = 0.024) and generalized symptoms (p = 0.039), and showed less frequent cutaneous involvement (p = 0.030) than those who did not achieve persistent (> 6 months) remission. Patients who achieved persistent remission also showed higher C-reactive protein (CRP) levels (p = 0.031) than those who did not. ANCA(-) CSS patients showed less frequent renal involvement. Characteristics of good responders were older age, diagnosis at earlier stages, less cutaneous involvement, more respiratory involvement, high CRP values, and more generalized symptoms.

The Catalina Sky Survey for Near-Earth Objects

NASA Astrophysics Data System (ADS)

Christensen, E.

The Catalina Sky Survey (CSS) specializes in the detection of the closest transients in our transient universe: near-Earth objects (NEOs). CSS is the leading NEO survey program since 2005, with a discovery rate of 500-600 NEOs per year. This rate is set to substantially increase starting in 2014 with the deployment of wider FOV cameras at both survey telescopes, while a proposed 3-telescope system in Chile would provide a new and significant capability in the Southern Hemisphere beginning as early as 2015. Elements contributing to the success of CSS may be applied to other surveys, and include 1) Real-time processing, identification, and reporting of interesting transients; 2) Human-assisted validation to ensure a clean transient stream that is efficient to the limits of the system (˜ 1σ); 3) an integrated follow-up capability to ensure threshold or high-priority transients are properly confirmed and followed up. Additionally, the open-source nature of the CSS data enables considerable secondary science (i.e. CRTS), and CSS continues to pursue collaborations to maximize the utility of the data.

The kinetics of lactate production and removal during whole-body exercise

PubMed Central

2012-01-01

Background Based on a literature review, the current study aimed to construct mathematical models of lactate production and removal in both muscles and blood during steady state and at varying intensities during whole-body exercise. In order to experimentally test the models in dynamic situations, a cross-country skier performed laboratory tests while treadmill roller skiing, from where work rate, aerobic power and blood lactate concentration were measured. A two-compartment simulation model for blood lactate production and removal was constructed. Results The simulated and experimental data differed less than 0.5 mmol/L both during steady state and varying sub-maximal intensities. However, the simulation model for lactate removal after high exercise intensities seems to require further examination. Conclusions Overall, the simulation models of lactate production and removal provide useful insight into the parameters that affect blood lactate response, and specifically how blood lactate concentration during practical training and testing in dynamical situations should be interpreted. PMID:22413898

Randomized pharmacokinetic cross-over study comparing two curcumin preparations in plasma and rectal tissue of healthy human volunteers

PubMed Central

Asher, Gary N.; Xie, Ying; Moaddel, Ruin; Sanghvi, Mitesh; Dossou, Katina S.S.; Kashuba, Angela D. M.; Sandler, Robert S.; Hawke, Roy L.

2016-01-01

Curcumin is poorly absorbed driving interest in new preparations. However, little is known about pharmacokinetics and tissue bioavailability between formulations. In this randomized, crossover study we evaluated the relationship between steady-state plasma and rectal tissue curcuminoid concentrations using standard and phosphatidylcholine curcumin extracts. There was no difference in the geometric mean plasma AUCs when adjusted for the 10-fold difference in curcumin dose between the two formulations. Phosphatidylcholine curcumin extract yielded only 20–30% plasma demethoxycurcumin and bisdemethoxycurcumin conjugates compared to standard extract, yet yielded 20-fold greater hexahydrocurcumin. When adjusting for curcumin dose, tissue curcumin concentrations were 5-fold greater for the phosphatidylcholine extract. Improvements in curcuminoid absorption due to phosphatidylcholine are not uniform across the curcuminoids. Furthermore, curcuminoid exposures in the intestinal mucosa are most likely due to luminal exposure rather than plasma disposition. Finally, once-daily dosing is sufficient to maintain detectable curcuminoids at steady-state in both plasma and rectal tissues. PMID:27503249

Fluconazole penetration in cerebral parenchyma in humans at steady state.

PubMed Central

Thaler, F; Bernard, B; Tod, M; Jedynak, C P; Petitjean, O; Derome, P; Loirat, P

1995-01-01

We studied fluconazole penetration in the brain in five patients who had a deep cerebral tumor whose removal required the excision of healthy brain tissue. Plasma and brain samples were simultaneously obtained after oral ingestion of 400 mg of fluconazole daily for 4 days (90% of steady state). Fluconazole penetration in healthy cerebral parenchyma was determined. Plasma and brain samples were assayed by high-pressure liquid chromatography. Concentrations in plasma and brain tissue were 13.5 +/- 5.5 micrograms/ml and 17.6 +/- 6.6 micrograms/g, respectively. The average ratio of concentrations in the brain and plasma (four patients) was 1.33 (range, 0.70 to 2.39). Despite the lack of data concerning the penetration of fluconazole in brain abscesses, these results should permit the use of a daily dose of 400 mg of fluconazole in prospective clinical studies that evaluate the effectiveness of this drug in the treatment of brain abscesses due to susceptible species of fungi. PMID:7625804

Washout and non-washout solutions of a system describing microbial fermentation process under the influence of growth inhibitions and maximal concentration of yeast cells.

PubMed

Kasbawati; Gunawan, Agus Yodi; Sidarto, Kuntjoro Adjie

2017-07-01

An unstructured model for the growth of yeast cell on glucose due to growth inhibitions by substrate, products, and cell density is discussed. The proposed model describes the dynamical behavior of fermentation system that shows multiple steady states for a certain regime of operating parameters such as inlet glucose and dilution rate. Two types of steady state solutions are found, namely washout and non-washout solutions. Furthermore, different numerical impositions to the two parameters put in evidence three results regarding non-washout solution: a unique locally stable non-washout solution, a unique locally stable non-washout solution towards which other nearby solutions exhibit damped oscillations, and multiple non-washout solutions where one is locally stable while the other is unstable. It is also found an optimal inlet glucose which produces the highest cell and ethanol concentration. Copyright © 2017 Elsevier Inc. All rights reserved.

Pulsed laser fluorometry for environmental monitoring

NASA Astrophysics Data System (ADS)

Saunders, G. C.; Martin, J. C.; Jett, J. H.; Wilder, M. E.; Martinez, A.; Bentley, B. F.; Lopez, J.; Hutson, L.

A compact pulsed laser fluorometer has been incorporated into a continuous flow system developed to detect acetylcholinesterase (AChE) inhibitors and/or primary amine compounds in air and water. A pulsed nitrogen laser pumped dye laser excites fluorescent reactants which flow continuously through a quartz flow cell. Data are collected, analyzed, and displayed using a Macintosh II personal computer. For detection of cholinesterase inhibitors the fluorogenic substrate N methylindoxyl acetate is used to monitor the activity of immobilized enzyme. Presence of inhibitors results in a decrease of steady state fluorescence. Detection of compounds containing primary amines is based on their reaction with fluorescamine to rapidly produce intensely fluorescent products. Compounds of interest to our research were amino acids, peptides, and proteins. An increase in steady state fluorescence could be cause to evaluate the reasons for the change. The detection limit of the protein, bovine serum albumin (BSA) in water, is 10 ppT. Nebulized BSA concentrated by the LANL air sampler can be detected at sub ppT original air concentration.

Modeling the non-steady state respiratory effects of remifentanil in awake and propofol-sedated healthy volunteers.

PubMed

Olofsen, Erik; Boom, Merel; Nieuwenhuijs, Diederik; Sarton, Elise; Teppema, Luc; Aarts, Leon; Dahan, Albert

2010-06-01

Few studies address the dynamic effect of opioids on respiration. Models with intact feedback control of carbon dioxide on ventilation (non-steady-state models) that correctly incorporate the complex interaction among drug concentration, end-tidal partial pressure of carbon dioxide concentration, and ventilation yield reliable descriptions and predictions of the behavior of opioids. The authors measured the effect of remifentanil on respiration and developed a model of remifentanil-induced respiratory depression. Ten male healthy volunteers received remifentanil infusions with different infusion speeds (target concentrations: 4-9 ng/ml; at infusion rates: 0.17-9 ng x ml x min) while awake and at the background of low-dose propofol. The data were analyzed with a nonlinear model consisting of two additive linear parts, one describing the depressant effect of remifentanil and the other describing the stimulatory effect of carbon dioxide on ventilation. The model adequately described the data including the occurrence of apnea. Most important model parameters were as follows: C50 for respiratory depression 1.6 +/- 0.03 ng/ml, gain of the respiratory controller (G) 0.42 - 0.1 l x min x Torr, and remifentanil blood effect site equilibration half-life (t(1/2)ke0) 0.53 +/- 0.2 min. Propofol caused a 20-50% reduction of C50 and G but had no effect on t(1/2)ke0. Apnea occurred during propofol infusion only. A simulation study revealed an increase in apnea duration at infusion speeds of 2.5-0.5 ng x ml x min followed by a reduction. At an infusion speed of < or = 0.31 ng x ml x min, no apnea was seen. The effect of varying remifentanil infusions with and without a background of low-dose propofol on ventilation and end-tidal partial pressure of carbon dioxide concentration was described successfully using a non-steady-state model of the ventilatory control system. The model allows meaningful simulations and predictions.

An Estimation of the Climatic Effects of Stratospheric Ozone Losses during the 1980s. Appendix K

NASA Technical Reports Server (NTRS)

MacKay, Robert M.; Ko, Malcolm K. W.; Shia, Run-Lie; Yang, Yajaing; Zhou, Shuntai; Molnar, Gyula

1997-01-01

In order to study the potential climatic effects of the ozone hole more directly and to assess the validity of previous lower resolution model results, the latest high spatial resolution version of the Atmospheric and Environmental Research, Inc., seasonal radiative dynamical climate model is used to simulate the climatic effects of ozone changes relative to the other greenhouse gases. The steady-state climatic effect of a sustained decrease in lower stratospheric ozone, similar in magnitude to the observed 1979-90 decrease, is estimated by comparing three steady-state climate simulations: 1) 1979 greenhouse gas concentrations and 1979 ozone, II) 1990 greenhouse gas concentrations with 1979 ozone, and III) 1990 greenhouse gas concentrations with 1990 ozone. The simulated increase in surface air temperature resulting from nonozone greenhouse gases is 0.272 K. When changes in lower stratospheric ozone are included, the greenhouse warming is 0.165 K, which is approximately 39% lower than when ozone is fixed at the 1979 concentrations. Ozone perturbations at high latitudes result in a cooling of the surface-troposphere system that is greater (by a factor of 2.8) than that estimated from the change in radiative forcing resulting from ozone depiction and the model's 2 x CO, climate sensitivity. The results suggest that changes in meridional heat transport from low to high latitudes combined with the decrease in the infrared opacity of the lower stratosphere are very important in determining the steady-state response to high latitude ozone losses. The 39% compensation in greenhouse warming resulting from lower stratospheric ozone losses is also larger than the 28% compensation simulated previously by the lower resolution model. The higher resolution model is able to resolve the high latitude features of the assumed ozone perturbation, which are important in determining the overall climate sensitivity to these perturbations.

Comparison of survival and clinicopathologic features in colorectal cancer among African American, Caucasian, and Chinese patients treated in the United States: Results from the surveillance epidemiology and end results (SEER) database.

PubMed

Lin, Junzhong; Qiu, Miaozhen; Xu, Ruihua; Dobs, Adrian Sandra

2015-10-20

African American patients of colorectal cancer (CRC) were found to have a worse prognosis than Caucasians, but it has not been fully understood about the survival difference among Chinese and these two races above. In this study, we used the Surveillance, Epidemiology and End Results database to analyze the survival difference among these three race/ethnicities in the United States. Adenocarcinoma patients of colorectal cancer with a race/ethnicity of Caucasian, Chinese and African American were enrolled for study. Patients were excluded if they had more than one primary cancer but the CRC was not the first one, had unknown cause of death or unknown survival months. The 5-year cause specific survival (CSS) was our primary endpoint. Totally, there were 585,670 eligible patients for analysis. Chinese patients had the best and African American patients had the worst 5-year CSS (66.7% vs 55.9%), P < 0.001. The 5-year CSS for Caucasian patients was 62.9%. Race/ethnicity was an independent prognostic factor in the multivariate analysis, P < 0.001. The comparison of clinicopathologic factors among these three race/ethnicities showed that the insurance coverage rate, income, percentage that completing high school and percentage of urban residence was lowest in the African American patients. Chinese patients had the highest percentage of married, while African American patients ranked lowest. More African American patients were diagnosed as stage IV and had high percentage of signet ring cell and mucinous adenocarcinoma. It is likely that biological differences as well as socioeconomic status both contribute to the survival disparity among the different race/ethnicities.

Comparison of survival and clinicopathologic features in colorectal cancer among African American, Caucasian, and Chinese patients treated in the United States: Results from the surveillance epidemiology and end results (SEER) database

PubMed Central

Dobs, Adrian Sandra

2015-01-01

African American patients of colorectal cancer (CRC) were found to have a worse prognosis than Caucasians, but it has not been fully understood about the survival difference among Chinese and these two races above. In this study, we used the Surveillance, Epidemiology and End Results database to analyze the survival difference among these three race/ethnicities in the United States. Adenocarcinoma patients of colorectal cancer with a race/ethnicity of Caucasian, Chinese and African American were enrolled for study. Patients were excluded if they had more than one primary cancer but the CRC was not the first one, had unknown cause of death or unknown survival months. The 5-year cause specific survival (CSS) was our primary endpoint. Totally, there were 585,670 eligible patients for analysis. Chinese patients had the best and African American patients had the worst 5-year CSS (66.7% vs 55.9%), P < 0.001. The 5-year CSS for Caucasian patients was 62.9%. Race/ethnicity was an independent prognostic factor in the multivariate analysis, P < 0.001. The comparison of clinicopathologic factors among these three race/ethnicities showed that the insurance coverage rate, income, percentage that completing high school and percentage of urban residence was lowest in the African American patients. Chinese patients had the highest percentage of married, while African American patients ranked lowest. More African American patients were diagnosed as stage IV and had high percentage of signet ring cell and mucinous adenocarcinoma. It is likely that biological differences as well as socioeconomic status both contribute to the survival disparity among the different race/ethnicities. PMID:26375551

Antioxidant pool in beer and kinetics of EPR spin-trapping.

PubMed

Kocherginsky, Nikolai M; Kostetski, Yuri Yu; Smirnov, Alex I

2005-08-24

The kinetics of spin-trap adduct formation in beer oxidation exhibits an induction period if the reaction is carried out at elevated temperatures and in the presence of air. This lag period lasts until the endogenous antioxidants are almost completely depleted, and its duration is used as an indicator of the flavor stability and shelf life of beer. This paper demonstrates that the total kinetics of the process can be characterized by three parameters-the lag period, the rate of spin-trap adduct formation, and, finally, the steady-state spin-adduct concentration. A steady-state chain reaction mechanism is described, and quantitative estimates of the main kinetic parameters such as the initiation rate, antioxidant pool, effective content of organic molecules participating in the chain reactions, and the rate constant of the 1-hydroxyethyl radical EtOH(*) spin-adduct disappearance are given. An additional new dimensionless parameter is suggested to characterize the antioxidant pool-the product of the lag time and the rate of spin-trap radical formation immediately after the lag time, normalized by the steady-state concentration of the adducts. The results of spin-tapping EPR experiments are compared with the nitroxide reduction kinetics measured in the same beer samples. It is shown that although the kinetics of nitroxide reduction in beer can be used to evaluate the reducing power of beer, the latter parameter does not correlate with the antioxidant pool. The relationship of free radical processes, antioxidant pool, reducing power, and beer staling is discussed.

KCC2-dependent Steady-state Intracellular Chloride Concentration and pH in Cortical Layer 2/3 Neurons of Anesthetized and Awake Mice.

PubMed

Boffi, Juan C; Knabbe, Johannes; Kaiser, Michaela; Kuner, Thomas

2018-01-01

Neuronal intracellular Cl - concentration ([Cl - ] i ) influences a wide range of processes such as neuronal inhibition, membrane potential dynamics, intracellular pH (pH i ) or cell volume. Up to date, neuronal [Cl - ] i has predominantly been studied in model systems of reduced complexity. Here, we implemented the genetically encoded ratiometric Cl - indicator Superclomeleon (SCLM) to estimate the steady-state [Cl - ] i in cortical neurons from anesthetized and awake mice using 2-photon microscopy. Additionally, we implemented superecliptic pHluorin (SE-pHluorin) as a ratiometric sensor to estimate the intracellular steady-state pH (pH i ) of mouse cortical neurons in vivo . We estimated an average resting [Cl - ] i of 6 ± 2 mM with no evidence of subcellular gradients in the proximal somato-dendritic domain and an average somatic pH i of 7.1 ± 0.2. Neither [Cl - ] i nor pH i were affected by isoflurane anesthesia. We deleted the cation-Cl - co-transporter KCC2 in single identified neurons of adult mice and found an increase of [Cl - ] i to approximately 26 ± 8 mM, demonstrating that under in vivo conditions KCC2 produces low [Cl - ] i in adult mouse neurons. In summary, neurons of the brain of awake adult mice exhibit a low and evenly distributed [Cl - ] i in the proximal somato-dendritic compartment that is independent of anesthesia and requires KCC2 expression for its maintenance.

Gravimetric analysis and differential scanning calorimetric studies on glycerin-induced skin hydration.

PubMed

Lee, Ae-Ri Cho; Moon, Hee Kyung

2007-11-01

A thermal gravimetric analysis (TGA) and a differential scanning calorimetry (DSC) were carried out to characterize the water property and an alteration of lipid phase transition of stratum corneum (SC) by glycerin. In addition, the relationship between steady state skin permeation rate and skin hydration in various concentrations of glycerin was investigated. Water vapor absorption-desorption was studied in the hairless mouse stratum corneum. Dry SC samples were exposed to different conc. of glycerin (0-50%) followed by exposure to dry air and the change in weight property was monitored over time by use of TGA. In DSC study, significant decrease in DeltaH of the lipid transition in 10% glycerin and water treated sample: the heat of lipid transition of normal, water, 10% glycerin treated SC were 6.058, 4.412 and 4.316 mJ/mg, respectively. In 10% glycerin treated SCs, the Tc of water shifts around 129 degrees C, corresponding to the weakly bound secondary water. In 40% glycerin treated SC, the Tc of water shifts to 144 degrees C corresponding to strongly bound primary water. There was a good correlation between the hydration property of the skin and the steady state skin flux with the correlation coefficient (r2=0.94). As the hydration increased, the steady state flux increased. As glycerin concentration increased, hydration property decreased. High diffusivity induced by the hydration effect of glycerin and water could be the major contributing factor for the enhanced skin permeation of nicotinic acid (NA).

High-Speed Imaging of the First Kink Mode Instability in a Magnetoplasmadynamic Thruster

NASA Technical Reports Server (NTRS)

Walker, Jonathan A.; Langendof, Samuel; Walker, Mitchell L. R.; Polzin, Kurt; Kimberlin, Adam

2013-01-01

One of the biggest challenges to efficient magnetoplasmadynamic thruster (MPDT) operation is the onset of high-frequency voltage oscillations as the discharge current is increased above a threshold value. The onset regime is closely related to magnetohydrodynamic instabilities known as kink modes. This work documents direct observation of the formation and quasi-steady state behavior of an argon discharge plasma in a MPDT operating at discharge currents of 8 to 10 kA for a pulse length of approximately 4 ms. A high-speed camera images the quasi-steady-state operation of the thruster at 26,143 fps with a frame exposure time of 10 micro s. A 0.9 neutral density filter and 488-nm argon line filter with a 10-nm bandwidth are used on separate trials to capture the time evolution of the discharge plasma. Frame-by-frame analysis of the power flux incident on the CCD sensor shows both the initial discharge plasma formation process and the steady-state behavior of the discharge plasma. Light intensity levels on the order of 4-6 W/m2 indicate radial and azimuthal asymmetries in the concentration of argon plasma in the discharge channel. The plasma concentration exhibits characteristics that suggest the presence of a helical plasma column. This helical behavior has been observed in previous experiments that characterize plasma kink mode instabilities indirectly. Therefore, the direct imaging of these plasma kink modes further supports the link between MPDT onset behavior and the excitation of the magnetohydrodynamic instabilities.

Modulatory effects of neuropsychopharmaca on intracellular pH of hippocampal neurones in vitro

PubMed Central

Bonnet, Udo; Bingmann, Dieter; Wiltfang, Jens; Scherbaum, Norbert; Wiemann, Martin

2010-01-01

Background and purpose: The intracellular pH (pHi) of neurones is tightly regulated by, for example, membrane-bound acid-exchangers and loaders. Nevertheless, excessive bioelectric activity lowers steady-state pHi. In turn, even a moderate acidification can inhibit neuronal activity, a process believed to be part of a negative feedback loop controlling neuronal excitation. As moclobemide, an antidepressant, and also some antiepileptic drugs can reduce neuronal pHi in hippocampus slices in vitro, we screened a panel of currently used neuropsychopharmaca for comparable effects. Experimental approach: BCECF-AM loaded hippocampal slices were superfused with 16 different neuroleptics, antidepressants and antiepileptics under bicarbonate-buffered conditions. Changes in steady-state pHi of CA3 neurones were measured fluorometrically. Key results: The antipsychotics haloperidol, clozapine, ziprasidone, and the antidepressants amitriptyline, doxepin, trimipramine, citalopram, mirtazapine, as well as the anticonvulsive drug tiagabine reversibly reduced the steady-state pHi by up to 0.35 pH-units in concentrations of 5–50 µM. In contrast, venlafaxine, the anticonvulsants carbamazepine, clonazepam, gabapentin, lamotrigine, zonisamide, and the mood stabilizer lithium had no effect on neuronal pHi. Conclusion and implications: These data substantiate the view that clinically relevant concentrations of neuroleptics and antidepressants can mediate changes in neuronal pHi, which may contribute to their pharmacological mode of action. Effects on pHi should be taken into account when therapeutic or even harmful effects of these drugs are evaluated. PMID:20015293

Area-under-the-curve monitoring of cyclosporine therapy: Performance of different assay methods and their target concentrations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grevel, J.; Napoli, K.L.; Gibbons, S.

1990-01-01

The measurement of areas under the concentration-time curve (AUC) was recently introduced as an alternative to trough level monitoring of cyclosporine therapy. The AUC is divided by the oral dosing interval to calculate an average concentration. All measurements are performed at clinical steady state. The initial evaluation of AUC monitoring showed advantages over trough level monitoring with concentrations of cyclosporine measured in serum by the polyclonal radioimmunoassay of Sandoz. This assay technique is no longer available and the following assays were performed in parallel during up to 173 AUC determinations in 51 consecutive renal transplant patients: polyclonal fluorescence polarization immunoassaymore » of Abbott in serum, specific and nonspecific monoclonal radioimmunoassays using {sup 3}H and {sup 125}I tracers in serum and whole blood, and high performance liquid chromatography in whole blood. Both trough levels and average concentrations at steady state measured by those different techniques were significantly correlated with the oral dose. The best correlation (r2 = 0.54) was shown by average concentrations measured in whole blood by the specific monoclonal radioimmunoassay of Sandoz ({sup 3}H tracer). This monitoring technique was also associated with the smallest absolute error between repeated observations in the same patient while the oral dose rate remained the same or was changed. Both allegedly specific monoclonal radioimmunoassays (with {sup 3}H and {sup 125}I tracer) measured significantly higher concentrations than the liquid chromatography.« less

Familial Churg-Strauss Syndrome in a Sister and Brother.

PubMed

Alyasin, Soheyla; Khoshkhui, Maryam; Amin, Reza

2015-06-01

Churg-Strauss syndrome (CSS) is a granulomatous small vessel vasculitis. It is characterized by asthma, allergic granulomatosis and vasculitis. This syndrome is rare in children. A 5 years old boy was admitted with cough, fever and dyspnea for 2 weeks. On the basis of laboratory data (peripheral eosinophilia), associated with skin biopsy, and history of CSS in his sister, this disease was eventually diagnosed. The patient had good response to corticosteroid. In every asthmatic patient with prolonged fever, eosinophilia and multisystemic involvment, CSS should be considered.

Pseudo Steady-State Free Precession for MR-Fingerprinting.

PubMed

Assländer, Jakob; Glaser, Steffen J; Hennig, Jürgen

2017-03-01

This article discusses the signal behavior in the case the flip angle in steady-state free precession sequences is continuously varied as suggested for MR-fingerprinting sequences. Flip angle variations prevent the establishment of a steady state and introduce instabilities regarding to magnetic field inhomogeneities and intravoxel dephasing. We show how a pseudo steady state can be achieved, which restores the spin echo nature of steady-state free precession. Based on geometrical considerations, relationships between the flip angle, repetition and echo time are derived that suffice to the establishment of a pseudo steady state. The theory is tested with Bloch simulations as well as phantom and in vivo experiments. A typical steady-state free precession passband can be restored with the proposed conditions. The stability of the pseudo steady state is demonstrated by comparing the evolution of the signal of a single isochromat to one resulting from a spin ensemble. As confirmed by experiments, magnetization in a pseudo steady state can be described with fewer degrees of freedom compared to the original fingerprinting and the pseudo steady state results in more reliable parameter maps. The proposed conditions restore the spin-echo-like signal behavior typical for steady-state free precession in fingerprinting sequences, making this approach more robust to B 0 variations. Magn Reson Med 77:1151-1161, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Nonuniformity of the chemical composition of a capillary discharge plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kocharyan, A. E.; Bobrova, N. A.; Sasorov, P. V.

A steady-state distribution of the concentration of two ion species in a capillary discharge plasma is studied using MHD equations for a plasma with a spatially nonuniform, time-dependent chemical composition. In our case, the set of equations is significantly simplified because of the steady-state character and symmetry of the problem. Even with such simplification, however, some results could be obtained only by numerical integration. The factors affecting the distribution of heavy ions are studied. It is shown that the distribution of the heavy impurity over the discharge cross section can be much more nonuniform than the distribution of the mainmore » component (hydrogen). A simple criterion for such a nonuniformity is obtained.« less

32 CFR 299.1 - Purpose.

Code of Federal Regulations, 2013 CFR

2013-07-01

... PROGRAM NATIONAL SECURITY AGENCY/CENTRAL SECURITY SERVICE (NSA/CSS) FREEDOM OF INFORMATION ACT PROGRAM... 22161. 2 See footnote 1 to this section. (b) This part applies to all NSA/CSS elements, field activities...

32 CFR 299.1 - Purpose.

Code of Federal Regulations, 2014 CFR

2014-07-01

... PROGRAM NATIONAL SECURITY AGENCY/CENTRAL SECURITY SERVICE (NSA/CSS) FREEDOM OF INFORMATION ACT PROGRAM... 22161. 2 See footnote 1 to this section. (b) This part applies to all NSA/CSS elements, field activities...

32 CFR 299.1 - Purpose.

Code of Federal Regulations, 2012 CFR

2012-07-01

... PROGRAM NATIONAL SECURITY AGENCY/CENTRAL SECURITY SERVICE (NSA/CSS) FREEDOM OF INFORMATION ACT PROGRAM... 22161. 2 See footnote 1 to this section. (b) This part applies to all NSA/CSS elements, field activities...

32 CFR 299.1 - Purpose.

Code of Federal Regulations, 2011 CFR

2011-07-01

... PROGRAM NATIONAL SECURITY AGENCY/CENTRAL SECURITY SERVICE (NSA/CSS) FREEDOM OF INFORMATION ACT PROGRAM... 22161. 2 See footnote 1 to this section. (b) This part applies to all NSA/CSS elements, field activities...

Mouse repeated electroconvulsive seizure (ECS) does not reverse social stress effects but does induce behavioral and hippocampal changes relevant to electroconvulsive therapy (ECT) side-effects in the treatment of depression

PubMed Central

Sigrist, Hannes; Seifritz, Erich; Fikse, Lianne; Bosker, Fokko J.; Schoevers, Robert A.; Klein, Hans C.

2017-01-01

Electroconvulsive therapy (ECT) is an effective treatment for depression, but can have negative side effects including amnesia. The mechanisms of action underlying both the antidepressant and side effects of ECT are not well understood. An equivalent manipulation that is conducted in experimental animals is electroconvulsive seizure (ECS). Rodent studies have provided valuable insights into potential mechanisms underlying the antidepressant and side effects of ECT. However, relatively few studies have investigated the effects of ECS in animal models with a depression-relevant manipulation such as chronic stress. In the present study, mice were first exposed to chronic social stress (CSS) or a control procedure for 15 days followed by ECS or a sham procedure for 10 days. Behavioral effects were investigated using an auditory fear conditioning (learning) and expression (memory) test and a treadmill-running fatigue test. Thereafter, immunohistochemistry was conducted on brain material using the microglial marker Iba-1 and the cholinergic fibre marker ChAT. CSS did not increase fear learning and memory in the present experimental design; in both the control and CSS mice ECS reduced fear learning and fear memory expression. CSS induced the expected fatigue-like effect in the treadmill-running test; ECS induced increased fatigue in CSS and control mice. In CSS and control mice ECS induced inflammation in hippocampus in terms of increased expression of Iba-1 in radiatum of CA1 and CA3. CSS and ECS both reduced acetylcholine function in hippocampus as indicated by decreased expression of ChAT in several hippocampal sub-regions. Therefore, CSS increased fatigue and reduced hippocampal ChAT activity and, rather than reversing these effects, a repeated ECS regimen resulted in impaired fear learning-memory, increased fatigue, increased hippocampal Iba-1 expression, and decreased hippocampal ChAT expression. As such, the current model does not provide insights into the mechanism of ECT antidepressant function but does provide evidence for pathophysiological mechanisms that might contribute to important ECT side-effects. PMID:28910337

Mouse repeated electroconvulsive seizure (ECS) does not reverse social stress effects but does induce behavioral and hippocampal changes relevant to electroconvulsive therapy (ECT) side-effects in the treatment of depression.

PubMed

van Buel, Erin M; Sigrist, Hannes; Seifritz, Erich; Fikse, Lianne; Bosker, Fokko J; Schoevers, Robert A; Klein, Hans C; Pryce, Christopher R; Eisel, Ulrich Lm

2017-01-01

Electroconvulsive therapy (ECT) is an effective treatment for depression, but can have negative side effects including amnesia. The mechanisms of action underlying both the antidepressant and side effects of ECT are not well understood. An equivalent manipulation that is conducted in experimental animals is electroconvulsive seizure (ECS). Rodent studies have provided valuable insights into potential mechanisms underlying the antidepressant and side effects of ECT. However, relatively few studies have investigated the effects of ECS in animal models with a depression-relevant manipulation such as chronic stress. In the present study, mice were first exposed to chronic social stress (CSS) or a control procedure for 15 days followed by ECS or a sham procedure for 10 days. Behavioral effects were investigated using an auditory fear conditioning (learning) and expression (memory) test and a treadmill-running fatigue test. Thereafter, immunohistochemistry was conducted on brain material using the microglial marker Iba-1 and the cholinergic fibre marker ChAT. CSS did not increase fear learning and memory in the present experimental design; in both the control and CSS mice ECS reduced fear learning and fear memory expression. CSS induced the expected fatigue-like effect in the treadmill-running test; ECS induced increased fatigue in CSS and control mice. In CSS and control mice ECS induced inflammation in hippocampus in terms of increased expression of Iba-1 in radiatum of CA1 and CA3. CSS and ECS both reduced acetylcholine function in hippocampus as indicated by decreased expression of ChAT in several hippocampal sub-regions. Therefore, CSS increased fatigue and reduced hippocampal ChAT activity and, rather than reversing these effects, a repeated ECS regimen resulted in impaired fear learning-memory, increased fatigue, increased hippocampal Iba-1 expression, and decreased hippocampal ChAT expression. As such, the current model does not provide insights into the mechanism of ECT antidepressant function but does provide evidence for pathophysiological mechanisms that might contribute to important ECT side-effects.

Electrochemical carbon dioxide concentrator: Math model

NASA Technical Reports Server (NTRS)

Marshall, R. D.; Schubert, F. H.; Carlson, J. N.

1973-01-01

A steady state computer simulation model of an Electrochemical Depolarized Carbon Dioxide Concentrator (EDC) has been developed. The mathematical model combines EDC heat and mass balance equations with empirical correlations derived from experimental data to describe EDC performance as a function of the operating parameters involved. The model is capable of accurately predicting performance over EDC operating ranges. Model simulation results agree with the experimental data obtained over the prediction range.

Emulation of Condensed Fuel Flames Using a Burning Rate Emulator (BRE) in Microgravity

NASA Technical Reports Server (NTRS)

Markan, A.; Quintiere, J. G.; Sunderland, P. B.; De Ris, J. L.; Stocker, D. P.

2017-01-01

The Burning Rate Emulator (BRE) is a gaseous fuel burner developed to emulate the burning of condensed phase fuels. The current study details several tests at the NASA Glenn 5-s drop facility to test the BRE technique in microgravity conditions. The tests are conducted for two burner diameters, 25 mm and 50 mm respectively, with methane and ethylene as the fuels. The ambient pressure, oxygen content and fuel flow rate are additional parameters. The microgravity results exhibit a nominally hemispherical flame with decelerating growth and quasi-steady heat flux after about 5 seconds. The BRE burner was evaluated with a transient analysis to assess the extent of steady-state achieved. The burning rate and flame height recorded at the end of the drop are correlated using two steady-state purely diffusive models. A higher burning rate for the bigger burner as compared to theory indicates the significance of gas radiation. The effect of the ambient pressure and oxygen concentration on the heat of gasification are also examined.

Sources and sinks for ammonia and nitrite on the early Earth and the reaction of nitrite with ammonia

NASA Technical Reports Server (NTRS)

Summers, D. P.

1999-01-01

An analysis of sources and sinks for ammonia and nitrite on the early Earth was conducted. Rates of formation and destruction, and steady state concentrations of both species were determined by steady state kinetics. The importance of the reaction of nitrite with ammonia on the feasibility of ammonia formation from nitrite was evaluated. The analysis considered conditions such as temperature, ferrous iron concentration, and pH. For sinks we considered the reduction of nitrite to ammonia, reaction between nitrite and ammonia, photochemical destruction of both species, and destruction at hydrothermal vents. Under most environmental conditions, the primary sink for nitrite is reduction to ammonia. The reaction between ammonia and nitrite is not an important sink for either nitrite or ammonia. Destruction at hydrothermal vents is important at acidic pH's and at low ferrous iron concentrations. Photochemical destruction, even in a worst case scenario, is unimportant under many conditions except possibly under acidic, low iron concentration, or low temperature conditions. The primary sink for ammonia is photochemical destruction in the atmosphere. Under acidic conditions, more of the ammonia is tied up as ammonium (reducing its vapor pressure and keeping it in solution) and hydrothermal destruction becomes more important.

The effects of hard water consumption on kidney function: Insights from mathematical modelling

NASA Astrophysics Data System (ADS)

Tambaru, David; Djahi, Bertha S.; Ndii, Meksianis Z.

2018-03-01

Most water sources in Nusa Tenggara Timur contain higher concentration of calcium and magnesium ions, which is known as hard water. Long-term consumption of hard water can cause kidney dysfunction, which may lead to the other diseases such as cerebrovascular disease, diabetes and others. Therefore, understanding the effects of hard water consumption on kidney function is of importance. This paper studies the transmission dynamics of kidney dysfunction due to the consumption of hard water using a mathematical model. We propose a new deterministic mathematical model comprising human and water compartments and conduct a global sensitivity analysis to determine the most influential parameters of the model. The Routh-Hurwitz criterion is used to examine the stability of the steady states. The results shows that the model has two steady states, which are locally stable. Moreover, we found that the most influential parameters are the maximum concentration of magnesium and calcium in the water, the increase rate of calcium and magnesium concentration in the water and the rate of effectiveness of water treatment. The results suggest that better water treatments are required to reduce the concentration of magnesium and calcium in the water. This aid in minimizing the probability of humans to attract kidney dysfunction. Furthermore, water-related data need to be collected for further investigation.

Uptake Kinetics and Trophic Transfer of Tungsten from Cabbage to a Herbivorous Animal Model

DOE PAGES

Lindsay, James H.; Kennedy, Alan J.; Seiter-Moser, Jennifer M.; ...

2017-10-20

This paper builds on previous studies on military-relevant tungsten (W) to more thoroughly explore environmental pathways and bioaccumulation kinetics during direct soil exposure versus trophic transfer and elucidate its relative accumulation and speciation in different snail organs. The modeled steady-state concentration and bioaccumulation factor (BAF) of W from soil into cabbage were 302 mg/kg and 0.55, respectively. Steady-state concentrations (34 mg/kg) and BAF values (0.05) obtained for the snail directly exposed to contaminated soil were lower than trophic transfer by consumption of W-contaminated cabbage (tissue concentration of 86 mg/kg; BAF of 0.36). Thus, consumption of contaminated food is the mostmore » important pathway for W mobility in this food chain. The highest concentrations of W compartmentalization were in the snail’s hepatopancreas based on wet chemistry and synchrotron-based investigations. Chemical speciation via inductively couple plasma mass spectrometry showed a higher degree of polytungstate partitioning in the hepatopancreas relative to the rest of the body. Based on synchrotron analysis, W was incorporated into the shell matrix during exposure, particularly during the regeneration of damaged shell. Finally, this offers the potential for application of the shell as a longer-term biomonitoring and forensics tool for historic exposure.« less

Lacosamide Pharmacokinetics in a Critically Ill Patient Receiving Continuous Venovenous Hemofiltration.

PubMed

Franquiz, Miguel J; Kalaria, Shamir N; Armahizer, Michael J; Gopalakrishnan, Mathangi; McCarthy, Paul J; Badjatia, Neeraj

2018-02-01

Lacosamide is a new-generation antiepileptic drug (AED) that is eliminated by both hepatic and renal mechanisms. Lacosamide elimination by continuous renal replacement therapy (CRRT) has never been studied. The objective of this case report was to describe lacosamide pharmacokinetics in the setting of CRRT. We describe a single patient admitted to the study center with status epilepticus and multiorgan failure. The patient required both continuous venovenous hemofiltration (CVVH) and several AEDs. He was receiving intravenous lacosamide 200 mg twice/day at steady state prior to sampling. Plasma lacosamide concentrations were derived using a validated high-performance liquid chromatography method. Parameters were calculated using Phoenix WinNonlin 7.1 software. The peak concentration at steady state was 7.7 mg/L, the trough concentration was 5.9 mg/L (goal 5-12 mg/L). The volume of distribution was 0.7 L/kg, the elimination half-life was 21 hours, and the sieving coefficient was 0.8 (± 0.06). Lacosamide was cleared by CVVH as demonstrated by the sieving coefficient, but plasma concentrations remained within goal range throughout the dosing interval. These results may suggest that lacosamide 200 mg twice/day is a useful dosing strategy for critically ill patients who require CVVH. © 2017 Pharmacotherapy Publications, Inc.

Uptake Kinetics and Trophic Transfer of Tungsten from Cabbage to a Herbivorous Animal Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lindsay, James H.; Kennedy, Alan J.; Seiter-Moser, Jennifer M.

This paper builds on previous studies on military-relevant tungsten (W) to more thoroughly explore environmental pathways and bioaccumulation kinetics during direct soil exposure versus trophic transfer and elucidate its relative accumulation and speciation in different snail organs. The modeled steady-state concentration and bioaccumulation factor (BAF) of W from soil into cabbage were 302 mg/kg and 0.55, respectively. Steady-state concentrations (34 mg/kg) and BAF values (0.05) obtained for the snail directly exposed to contaminated soil were lower than trophic transfer by consumption of W-contaminated cabbage (tissue concentration of 86 mg/kg; BAF of 0.36). Thus, consumption of contaminated food is the mostmore » important pathway for W mobility in this food chain. The highest concentrations of W compartmentalization were in the snail’s hepatopancreas based on wet chemistry and synchrotron-based investigations. Chemical speciation via inductively couple plasma mass spectrometry showed a higher degree of polytungstate partitioning in the hepatopancreas relative to the rest of the body. Based on synchrotron analysis, W was incorporated into the shell matrix during exposure, particularly during the regeneration of damaged shell. Finally, this offers the potential for application of the shell as a longer-term biomonitoring and forensics tool for historic exposure.« less

Computational Social Science: Exciting Progress and Future Challenges

NASA Astrophysics Data System (ADS)

Watts, Duncan

The past 15 years have witnessed a remarkable increase in both the scale and scope of social and behavioral data available to researchers, leading some to herald the emergence of a new field: ``computational social science.'' Against these exciting developments stands a stubborn fact: that in spite of many thousands of published papers, there has been surprisingly little progress on the ``big'' questions that motivated the field in the first place--questions concerning systemic risk in financial systems, problem solving in complex organizations, and the dynamics of epidemics or social movements, among others. In this talk I highlight some examples of research that would not have been possible just a handful of years ago and that illustrate the promise of CSS. At the same time, they illustrate its limitations. I then conclude with some thoughts on how CSS can bridge the gap between its current state and its potential.

Modeling Single and Repeated Dose Pharmacokinetics of PFOA in Mice

EPA Science Inventory

Perfluorooctanoic acid (PFOA) displays complicated pharmacokinetics in that plasma serum concentration indicates a long half life – 3.8 years in humans (Olsen et al. 2007) – but also rapidly achieves steady-state (Lau et al., 2006). Attempts to address this have included using d...

A non-linear steady state characteristic performance curve for medium temperature solar energy collectors

NASA Astrophysics Data System (ADS)

Eames, P. C.; Norton, B.

A numerical simulation model was employed to investigate the effects of ambient temperature and insolation on the efficiency of compound parabolic concentrating solar energy collectors. The limitations of presently-used collector performance characterization curves were investigated and a new approach proposed.

Influence of wind-induced air pressure fluctuations on topsoil gas concentrations within a Scots pine forest

NASA Astrophysics Data System (ADS)

Mohr, Manuel; Laemmel, Thomas; Maier, Martin; Schindler, Dirk

2017-04-01

Commonly it is assumed that soil gas transport is dominated by molecular diffusion. Few recent studies indicate that the atmosphere above the soil triggers non-diffusive gas transport processes in the soil, which can enhance soil gas transport and therefore soil gas efflux significantly. During high wind speed conditions, the so called pressure pumping effect has been observed: the enhancement of soil gas transport through dynamic changes in the air pressure field above the soil. However, the amplitudes and frequencies of the air pressure fluctuations responsible for pressure pumping are still uncertain. Moreover, an in situ observation of the pressure pumping effect is still missing. To investigate the pressure pumping effect, airflow measurements above and below the canopy of a Scots pine forest and high-precision relative air pressure measurements were conducted in the below-canopy space and in the soil over a measurement period of 16 weeks. To monitor the soil gas transport, a newly developed gas measurement system was used. The gas measurement system continuously injects helium as a tracer gas into the soil until a diffusive steady state is reached. With the steady state concentration profile of the tracer gas, it is possible to inversely model the gas diffusion coefficient profile of the soil. If the gas diffusion coefficient profile differed from steady state, we deduced that the soil gas transport is not only diffusive, but also influenced by non-diffusive processes. Results show that the occurrence of small air pressure fluctuations is strongly dependent on the mean above-canopy wind speed. The wind-induced air pressure fluctuations have mean amplitudes up to 10 Pa and lie in the frequency range 0.01-0.1 Hz. To describe the pumping motion of the air pressure field, the pressure pumping coefficient (PPC) was defined as the mean change in pressure per second. The PPC shows a clear quadratic dependence on mean above-canopy wind speed. Empirical modelling of the measured topsoil helium concentration demonstrated that the PPC is the most important predictor for changes in the topsoil helium concentration. Comparison of time periods with high PPC and periods of low PPC showed that the soil gas diffusion coefficient in depths between 5-10 cm increased up to 30% during periods of high PPC compared to steady state. Thus, the air pressure fluctuations observed in the atmosphere and described by the PPC penetrate into the soil and influence the topsoil gas transport.

Neptunium(V) and neptunium(VI) solubilities in synthetic brines of interest to the Waste Isolation Pilot Plant (WIPP)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Novak, C.F.; Nitsche, H.; Silber, H.B.

1996-12-31

The solubility of Np(V) and Np(VI) has been measured in three synthetic Na-K-Mg-Cl brines in the presence of CO{sub 2}(g). Experiments were prepared from oversaturation by adding an excess of NpO{sub 2}{sup +} or NpO{sub 2}{sup 2+} to the brines and allowing the neptunium solids to precipitate. Vessels were maintained in contact with fixed CO{sub 2}(g) partial pressures at constant pH and 24 {+-} 1 C. Dissolved Np(V) concentrations decreased several orders of magnitude within the first 100 days of the experiment, while dissolved Np(VI) concentrations decreased initially but then remained relatively constant for more than 400 days. The solidmore » phases formed in all experiments were identified by X-ray powder diffraction as KNpO{sub 2}CO{sub 3}{center_dot}xH{sub 2}O(s). Steady state concentrations for Np(V) are similar to those observed for Pu(V) in the same brines under the same conditions, where Pu occurs predominantly as Pu(V). Similarly, steady state concentrations for Np(VI), which was not reduced over a two year period, compare well with measured Pu(VI) concentrations in the same brines before the Pu(VI) was reduced to Pu(V).« less

Context sensitive solutions (CSS) online training course development.

DOT National Transportation Integrated Search

2009-04-01

A key to the successful implementation of Context Sensitive Solutions (CSS) for Illinois transportation projects is the : active and informed participation of Illinois Department of Transportations (IDOT) stakeholders. Essential to this : particip...

Systems development of a stall/spin research facility using remotely controlled/augmented aircraft models. Volume 1: Systems overview

NASA Technical Reports Server (NTRS)

Montoya, R. J.; Jai, A. R.; Parker, C. D.

1979-01-01

A ground based, general purpose, real time, digital control system simulator (CSS) is specified, developed, and integrated with the existing instrumentation van of the testing facility. This CSS is built around a PDP-11/55, and its operational software was developed to meet the dual goal of providing the immediate capability to represent the F-18 drop model control laws and the flexibility for expansion to represent more complex control laws typical of control configured vehicles. Overviews of the two CSS's developed are reviewed as well as the overall system after their integration with the existing facility. Also the latest version of the F-18 drop model control laws (REV D) is described and the changes needed for its incorporation in the digital and analog CSS's are discussed.

Measuring teacher self-report on classroom practices: Construct validity and reliability of the Classroom Strategies Scale-Teacher Form.

PubMed

Reddy, Linda A; Dudek, Christopher M; Fabiano, Gregory A; Peters, Stephanie

2015-12-01

This article presents information about the construct validity and reliability of a new teacher self-report measure of classroom instructional and behavioral practices (the Classroom Strategies Scales-Teacher Form; CSS-T). The theoretical underpinnings and empirical basis for the instructional and behavioral management scales are presented. Information is provided about the construct validity, internal consistency, test-retest reliability, and freedom from item-bias of the scales. Given previous investigations with the CSS Observer Form, it was hypothesized that internal consistency would be adequate and that confirmatory factor analyses (CFA) of CSS-T data from 293 classrooms would offer empirical support for the CSS-T's Total, Composite and subscales, and yield a similar factor structure to that of the CSS Observer Form. Goodness-of-fit indices of χ2/df, Root Mean Square Error of Approximation, Goodness of Fit Index, and Adjusted Goodness of Fit Index suggested satisfactory fit of proposed CFA models whereas the Comparative Fit Index did not. Internal consistency estimates of .93 and .94 were obtained for the Instructional Strategies and Behavioral Strategies Total scales respectively. Adequate test-retest reliability was found for instructional and behavioral total scales (r = .79, r = .84, percent agreement 93% and 93%). The CSS-T evidences freedom from item bias on important teacher demographics (age, educational degree, and years of teaching experience). Implications of results are discussed. (c) 2015 APA, all rights reserved).

Preoperative Lateralization Modalities for Cushing Disease: Is Dynamic Magnetic Resonance Imaging or Cavernous Sinus Sampling More Predictive of Intraoperative Findings?

PubMed

Sun, Hai; Yedinak, Chris; Ozpinar, Alp; Anderson, Jim; Dogan, Aclan; Delashaw, Johnny; Fleseriu, Maria

2015-06-01

Objective To analyze whether cavernous sinus sampling (CSS) and dynamic magnetic resonance imaging (dMRI) are consistent with intraoperative findings in Cushing disease (CD) patients. Design Retrospective outcomes study. Setting Oregon Health & Science University; 2006 and 2013. Participants A total of 37 CD patients with preoperative dMRI and CSS to confirm central adrenocorticotropic hormone (ACTH) hypersecretion. Patients were 78% female; mean age was 41 years (at diagnosis), and all had a minimum of 6 months of follow-up. Main Outcome Measures Correlations among patient characteristics, dMRI measurements, CSS results, and intraoperative findings. Results All CSS indicated presence of CD. Eight of 37 patients had no identifiable tumor on dMRI. Three of 37 patients had no tumor at surgery. dMRI tumor size was inversely correlated with age (rs = - 0.4; p = 0.01) and directly correlated to intraoperative lateralization (rs = 0.3; p < 0.05). Preoperative dMRI was directly correlated to intraoperative lateralization (rs = 0.5; p < 0.002). CSS lateralization showed no correlation with intraoperative findings (rs = 0.145; p = 0.40) or lateralization observed on preoperative dMRI (rs = 0.17; p = 0.29). Postoperative remission rate was 68%. Conclusion dMRI localization was most consistent with intraoperative findings; CSS results were less reliable. Results suggest that small ACTH-secreting tumors continue to pose a challenge to reliable preoperative localization.

Clinical features and prognostic factors of Churg-Strauss syndrome

PubMed Central

Kim, Mi-Yeong; Sohn, Kyoung-Hee; Song, Woo-Jung; Park, Heung-Woo; Cho, Sang-Heon; Min, Kyung-Up

2014-01-01

Background/Aims Churg-Strauss syndrome (CSS) is a rare systemic necrotizing small-vessel vasculitis, with accompanying bronchial asthma, eosinophilia, and eosinophilic infiltration of various tissues. The purposes of our study were to characterize the clinical features of CSS and to identify factors associated with CSS prognosis in Koreans. Methods Medical records were reviewed retrospectively for all physician-diagnosed CSS patients in the Seoul National University Hospital between January 1990 and March 2011. Results Data from 52 CSS patients were analyzed. The respiratory tract was the most commonly involved organ (90.4%). Renal involvement was less frequent in antineutrophilic cytoplasmic antibody (ANCA)(-) patients than in ANCA(+) patients (p = 0.048). Clinical remission occurred in 95.3% of patients, but 16.3% of them relapsed. Patients who maintained remission for more than 6 months were relatively older (median, 51 years) at diagnosis (p = 0.004), had been diagnosed in earlier stages (p = 0.027), showed more frequent respiratory involvement (p = 0.024) and generalized symptoms (p = 0.039), and showed less frequent cutaneous involvement (p = 0.030) than those who did not achieve persistent (> 6 months) remission. Patients who achieved persistent remission also showed higher C-reactive protein (CRP) levels (p = 0.031) than those who did not. Conclusions ANCA(-) CSS patients showed less frequent renal involvement. Characteristics of good responders were older age, diagnosis at earlier stages, less cutaneous involvement, more respiratory involvement, high CRP values, and more generalized symptoms. PMID:24574837

Marital status and survival in patients with renal cell carcinoma.

PubMed

Li, Yan; Zhu, Ming-Xi; Qi, Si-Hua

2018-04-01

Previous studies have shown that marital status is an independent prognostic factor for survival in several types of cancer. In this study, we investigated the effects of marital status on survival outcomes among renal cell carcinoma (RCC) patients.We identified patients diagnosed with RCC between 1973 and 2013 from the Surveillance, Epidemiology and End Results (SEER) database. Kaplan-Meier analysis and Cox regression were used to identify the effects of marital status on overall survival (OS) and cancer-specific survival (CSS).We enrolled 97,662 eligible RCC patients, including 64,884 married patients, and 32,778 unmarried (9831 divorced/separated, 9692 widowed, and 13,255 single) patients at diagnosis. The 5-year OS and CSS rates of the married, separated/divorced, widowed, and single patients were 73.7%, 69.5%, 58.3%, and 73.2% (OS), and 82.2%, 80.7%, 75.7%, and 83.3% (CSS), respectively. Multivariate Cox regression showed that, compared with married patients, widowed individuals showed poorer OS (hazard ratio, 1.419; 95% confidence interval, 1.370-1.469) and CSS (hazard ratio, 1.210; 95% confidence interval, 1.144-1.279). Stratified analyses and multivariate Cox regression showed that, in the insured and uninsured groups, married patients had better survival outcomes while widowed patients suffered worse OS outcomes; however, this trend was not significant for CSS.In RCC patients, married patients had better survival outcomes while widowed patients tended to suffer worse survival outcomes in terms of both OS and CSS.

Marital status and survival in patients with renal cell carcinoma

PubMed Central

Li, Yan; Zhu, Ming-xi; Qi, Si-hua

2018-01-01

Abstract Previous studies have shown that marital status is an independent prognostic factor for survival in several types of cancer. In this study, we investigated the effects of marital status on survival outcomes among renal cell carcinoma (RCC) patients. We identified patients diagnosed with RCC between 1973 and 2013 from the Surveillance, Epidemiology and End Results (SEER) database. Kaplan–Meier analysis and Cox regression were used to identify the effects of marital status on overall survival (OS) and cancer-specific survival (CSS). We enrolled 97,662 eligible RCC patients, including 64,884 married patients, and 32,778 unmarried (9831 divorced/separated, 9692 widowed, and 13,255 single) patients at diagnosis. The 5-year OS and CSS rates of the married, separated/divorced, widowed, and single patients were 73.7%, 69.5%, 58.3%, and 73.2% (OS), and 82.2%, 80.7%, 75.7%, and 83.3% (CSS), respectively. Multivariate Cox regression showed that, compared with married patients, widowed individuals showed poorer OS (hazard ratio, 1.419; 95% confidence interval, 1.370–1.469) and CSS (hazard ratio, 1.210; 95% confidence interval, 1.144–1.279). Stratified analyses and multivariate Cox regression showed that, in the insured and uninsured groups, married patients had better survival outcomes while widowed patients suffered worse OS outcomes; however, this trend was not significant for CSS. In RCC patients, married patients had better survival outcomes while widowed patients tended to suffer worse survival outcomes in terms of both OS and CSS. PMID:29668592

Impact of a diagnosis-related group payment system on cesarean section in Korea.

PubMed

Kim, Seung Ju; Han, Kyu-Tae; Kim, Sun Jung; Park, Eun-Cheol; Park, Hye Ki

2016-06-01

Cesarean sections (CSs) are the most expensive method of delivery, which may affect the physician's choice of treatment when providing health services to patients. We investigated the effects of the diagnosis-related group (DRG)-based payment system on CSs in Korea. We used National Health Insurance claim data from 2011 to 2014, which included 1,289,989 delivery cases at 674 hospitals. We used a generalized estimating equation model to evaluate the association between the likelihood of cesarean delivery and the length of the DRG adoption period. A total of 477,309 (37.0%) delivery cases were performed by CSs. We found that a longer DRG adoption period was associated with a lower odds ratio of CSs (odds ratio [OR]: 0.997, 95% CI: 0.996-0.998). In addition, a longer DRG adoption period was associated with a lower odds ratio for CSs in hospitals that had voluntarily adopted the DRG system. Similar results were also observed for urban hospitals, primiparas, and those under 28 years old and over 33 years old. Our results suggest that the change in the reimbursement system was associated with a low likelihood of CSs. The impact of DRG adoption on cesarean delivery can also be expected to increase with time, as our finding provides evidence that the reimbursement system is associated with the health provider's decision to provide health services for patients. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Drug Loading Capacity of Environmentally Sensitive Polymeric Microgels

NASA Astrophysics Data System (ADS)

McDonough, Ryan; Streletzky, Kiril; Bayachou, Mekki; Peiris, Pubudu

2009-10-01

Microgel nanoparticles consisting of cross-linked polymer hydroxypropyl cellulose chains have a temperature dependent volume phase transition, prompting the use of microgels for controlled drug transport. Drug particles aggregate in the slightly hydrophobic interior of microgels. Microgels are stored in equilibrium until the critical temperature (Tv) is reached and the volume phase transition limits available space, thus expelling the drugs. Our study was designed to test this property of microgels using amperometric electrochemical methods. A critical assumption was that small molecules inside microgels would not interact via diffusion with the electrode surface and thus total current would be decreased across the electrodes in a microgel sample. A room temperature (Troom) flow amperometric measurement comparing microgel/tylenol solution with control tylenol samples yielded about 20% tylenol concentration reduction of the microgel sample. Results from the steady state electrochemical experiment confirm the presence of about 20% tylenol concentration drop of the microgel sample compared to control sample at Troom. Using the steady-state experiment with a cyclic temperature ramp from Troom to beyond Tv showed that the tylenol concentration change between the temperature extremes was greater for the microgel solution than for the control solution.

Impact of marital status on survival of gastric adenocarcinoma patients: Results from the Surveillance Epidemiology and End Results (SEER) Database.

PubMed

Qiu, Miaozhen; Yang, Dajun; Xu, Ruihua

2016-02-15

Marital status was found to be an independent prognostic factor for survival in various cancer types. In this study, we used the Surveillance, Epidemiology and End Results database to analyze the survival difference among different marital status in the United States. Gastric adenocarcinoma patients from 2004-2012 were enrolled for study. The 5-year cause specific survival (CSS) was our primary endpoint. Totally 29,074 eligible patients were identified. We found that more male patients were married than female. Asian patients had the highest percentages of married than the other races. More married patients were covered by the insurance. Married patients had better 5-year CSS than unmarried, 30.6% vs 25.7%, P < 0.001. The median overall CSS was 17.87 and 13.61 months for the married and unmarried patients, hazard ratio: 1.09 (95% confidence interval: 1.01-1.17), P = 0.027. The survival difference was significant in the insured but not in the uninsured patients. Widowed patients had the worst prognosis compared with other groups even though they had more stage I disease and more well / moderate differentiated tumors. These results indicated that unmarried gastric adenocarcinoma patients were at greater risk of cancer specific mortality. We recommend every patient should have access to best available gastric cancer therapy.

The steady-state pharmacokinetics and bioequivalence of carprofen administered orally and subcutaneously in dogs.

PubMed

Clark, T P; Chieffo, C; Huhn, J C; Nimz, E L; Wang, C; Boy, M G

2003-06-01

Eighteen male Beagle dogs were randomized to oral (p.o.) or subcutaneous (s.c.) carprofen administration in a two-sequence, two-period crossover design with a 10-day washout between periods. Twenty-five milligrams of carprofen was administered p.o. or s.c. every 12 h for 7 days. Plasma concentrations of carprofen collected after the first and last treatments were determined by high-performance liquid chromatography. Carprofen concentration data were natural log transformed and geometric means were calculated for maximum plasma concentration (Cmax) and area under the plasma concentration-time curve (AUC0--12) following the first dose and Cmax and AUC0--12 following administration of the last dose. Formulations were considered bioequivalent if the 90% confidence interval (CI) of the mean difference for each variable between formulations were within -20% and 25% of the oral formulation. The mean Cmax and AUC0--12 were 16.9 microg/mL and 73.1 microg. h/mL, respectively, following a single oral dose and 8.0 microg/mL and 64.3 microg x h/mL, respectively, following a single s.c. injection. The 90% CI for Cmax (-56.8 to -48.7%) was outside of the bioequivalence criteria whereas the 90% CI for AUC0--12 (-16.3 to -7.5%) was within the bioequivalence criteria. At steady-state, the mean Cmax and AUC0--12 were 18.7 microg/mL and 101.9 microg x h/mL, respectively, following p.o. administration and 14.7 microg/mL and 111.0 microg x h/mL, respectively, following s.c. injection. The 90% CI was outside the bioequivalence criteria for Cmax (-30.8 to -10.8) but within the bioequivalence criteria for AUC0--12 (2.3-15.9%). The results of this study indicate that peak plasma concentrations of carprofen differ when administered p.o. and s.c., but that total drug exposure following a single dose and at steady-state are bioequivalent.

Comparison of the effectiveness of hands-on versus online education in child passenger safety.

PubMed

Mantha, Anita; Beckworth, Kristen L; Ansiaux, John A; Chen, Carol C; Hoffman, Benjamin; Shenoi, Rohit P

2017-08-28

Community paediatricians' knowledge of appropriate child safety seat (CSS) use in vehicles may be inadequate. We compared the effectiveness of hands-on and online education in improving and retaining child passenger safety (CPS) knowledge and skills among paediatric trainees. Paediatric trainees were randomised to receive hands-on skills training versus a 1-hour online module in CPS. CSS knowledge and installation skills were assessed using a validated 10-item/point questionnaire and an assessment tool respectively at baseline and after 6 months. Preintervention and postintervention knowledge improvement and CSS installation skills between groups were assessed using paired t-tests and effect size ( d ). Forty-eight students agreed to participate and were randomised. Thirty-nine completed training (hands-on: 23 and online: 15). At entry, no significant differences in learners' demographics and prior CPS education existed. Baseline CPS knowledge scores did not differ significantly between groups (p=0.26). Postintervention, both groups demonstrated a significant increase in knowledge scores (hands-on=3.1 (95% CI 2.4 to 3.7), p<0.0001; online=2.6 (95% CI 1.9 to 3.3), p<0.0001), though the pre-post gain in knowledge scores were not significantly different between groups (p=0.35). At follow-up, both groups demonstrated a significant increase in knowledge scores (hands-on=1.8 (95% CI 1.2 to 2.4), p<0.0001; online=1.1 (95% CI 0.7 to 1.6), p<0.0001) with the hands-on group scores significantly better than the online group (p<0.02). The long-term gain in knowledge scores was not significantly different between groups (p=0.12).Baseline CSS installation skill scores did not significantly differ between groups for forward-facing seats (p=0.16) and rear-facing seats (p=0.51). At follow-up, mean CSS installation skill scores significantly increased for the hands-on group (forward-facing seat: 0.8 (95% CI 0.16 to 1.44), p<0.02; rear-facing seat: 1.2 (95% CI 0.6 to 1.7), p<0.001) but not for the online group (forward-facing seat: 0.9 (95% CI -0.08 to 1.9), p=0.07); rear-facing seat: -0.2 (95% CI -1.1 to 0.7), p=0.6). Among paediatric trainees, hands-on and online CPS education are both effective in improving long-term CPS knowledge. Long-term installation skills for forward-facing and rear-facing CSS persist for hands-on education but are inconclusive for online education. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Multiple Thromboembolic Cerebral Infarctions from the Aorta in a Patient with Churg-Strauss Syndrome.

PubMed

Okada, Hideo

2017-02-01

Ischemic stroke is a rare complication of Churg-Strauss syndrome (CSS) and its pathogenesis has not been well clarified yet. We report a case of cerebral infarction in a patient with CSS due to embolism from a thrombus on the wall of the aorta. A 39-year-old man had multiple cerebral infarctions with symptoms of mild left hemiparesis and reduced vision. He was clinically diagnosed to have CSS based on remarkable eosinophilia, history of asthma, sinusitis, pulmonary infiltrates, and histologically proven extravascular eosinophilic infiltrates in the specimen of gastric mucosa. Cerebral angiography did not show any stenotic lesions in cerebral arteries. A thrombus was detected on the wall of the aorta by transesophageal echocardiography, which was considered as the source of embolism. The thrombus resolved on follow-up examination 3 months after the onset of the stroke. This is the first case report on cerebral infarction caused by aortogenic thromboembolism in a CSS patient. Other than cerebral vasculitis, embolism from cardiovascular system, including the wall of the aorta, is a possible cause of cerebral infarctions in a CSS patient. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Chinese English Learners' Strategic Competence.

PubMed

Wang, Dianjian; Lai, Hongling; Leslie, Michael

2015-12-01

The present study aims to investigate Chinese English learners' ability to use communication strategies (CSs). The subjects are put in a relatively real English referential communication setting and the analyses of the research data show that Chinese English learners, when encountering problems in foreign language (FL) communication, are characterized by the frequent use of substitution, approximation, circumlocution, literal translation, exemplification, word-coinage, repetition, and the infrequent use of cultural-knowledge and paralinguistic CSs. The rare use of paralinguistic strategies is found to be typical of Chinese English learners. The high frequency of literal translation, one first language (L1)-based strategy in our study sample, suggests that FL learners' use of L1-based CSs may depend more upon the developmental stage of their target language than the typology distance between L1 and the target language. The frequency of repetition reveals one fact that the Chinese English learners lack variety and flexibility in their use of CSs. Based on these findings, it was indicated that learners' use of CSs is influenced by a variety of factors, among which the development stage of their interlanguage and their cultural background are identified as two important factors. Some implications are finally suggested for the English foreign language teaching practice in China.

Management of Male Breast Cancer in the United States: A Surveillance, Epidemiology and End Results Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fields, Emma C., E-mail: emma.fields@ucdenver.edu; DeWitt, Peter; Fisher, Christine M.

Purpose: To analyze the stage-specific management of male breast cancer (MBC) with surgery and radiation therapy (RT) and relate them to outcomes and to female breast cancer (FBC). Methods and Materials: The Surveillance, Epidemiology, and End Results database was queried for all primary invasive MBC and FBC diagnosed from 1973 to 2008. Analyzable data included age, race, registry, grade, stage, estrogen and progesterone receptor status, type of surgery, and use of RT. Stage was defined as localized (LocD): confined to the breast; regional (RegD): involving skin, chest wall, and/or regional lymph nodes; and distant: M1. The primary endpoint was cause-specificmore » survival (CSS). Results: A total of 4276 cases of MBC and 718,587 cases of FBC were identified. Male breast cancer constituted 0.6% of all breast cancer. Comparing MBC with FBC, mastectomy (M) was used in 87.4% versus 38.3%, and breast-conserving surgery in 12.6% versus 52.6% (P<10{sup −4}). For males with LocD, CSS was not significantly different for the 4.6% treated with lumpectomy/RT versus the 70% treated with M alone (hazard ratio [HR] 1.33; 95% confidence interval [CI] 0.49-3.61; P=.57). Postmastectomy RT was delivered in 33% of males with RegD and was not associated with an improvement in CSS (HR 1.11; 95% CI 0.88-1.41; P=.37). There was a significant increase in the use of postmastectomy RT in MBC over time: 24.3%, 27.2%, and 36.8% for 1973-1987, 1988-1997, and 1998-2008, respectively (P<.0001). Cause-specific survival for MBC has improved: the largest significant change was identified for men diagnosed in 1998-2008 compared with 1973-1987 (HR 0.73; 95% CI 0.60-0.88; P=.0004). Conclusions: Surgical management of MBC is dramatically different than for FBC. The majority of males with LocD receive M despite equivalent CSS with lumpectomy/RT. Postmastectomy RT is greatly underutilized in MBC with RegD, although a CSS benefit was not demonstrated. Outcomes for MBC are improving, attributable to improved therapy and its use in this unscreened population.« less

Estimating the safety benefits of context sensitive solutions.

DOT National Transportation Integrated Search

2011-11-01

Context Sensitive Solutions (CSS), also commonly known by the original name Context Sensitive Design : (CSD), is an alternative approach to the conventional transportation-oriented decision-making and design : processes. The CSS approach can be used ...

RAPID MEASUREMENT OF AQUEOUS HYDROXYL RADICAL CONCENTRATIONS IN STEADY-STATE HO· FLUX SYSTEMS

EPA Science Inventory

The spin-trap compound a-(4-pyridyl-1-oxide)-N-tert-butyl-nitrone (4-POBN) is utilized for the detection and quantitation of the hydroxyl radical (HO·) in aqueous solution. Capillary electrophoresis enables rapid analysis of the probe compound. The thermally unstable HO· radical ...

40 CFR 90.301 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-07-01

... the test engine is operated using a steady state test cycle on an engine dynamometer. The exhaust... concentrations are converted to mass emission rates in grams per hour based on either fuel flow, fuel flow and engine intake air flow, or exhaust volume flow. Weighted emission rates are reported as grams per brake...

40 CFR 1065.546 - Validation of minimum dilution ratio for PM batch sampling.

Code of Federal Regulations, 2010 CFR

2010-07-01

... flows and/or tracer gas concentrations for transient and ramped modal cycles to validate the minimum... mode-average values instead of continuous measurements for discrete mode steady-state duty cycles... molar flow data. This involves determination of at least two of the following three quantities: Raw...

Hydrogen concentrations as an indicator of the predominant terminal electron-accepting reactions in aquatic sediments

USGS Publications Warehouse

Lovley, D.R.; Goodwin, S.

1988-01-01

Factors controlling the concentration of dissolved hydrogen gas in anaerobic sedimentary environments were investigated. Results, presented here or previously, demonstrated that, in sediments, only microorganisms catalyze the oxidation of H2 coupled to the reduction of nitrate, Mn(IV), Fe(III), sulfate, or carbon dioxide. Theoretical considerations suggested that, at steady-state conditions, H2 concentrations are primarily dependent upon the physiological characteristics of the microorganism(s) consuming the H2 and that organisms catalyzing H2 oxidation, with the reduction of a more electrochemically positive electron acceptor, can maintain lower H2 concentrations than organisms using electron acceptors which yield less energy from H2 oxidation. The H2 concentrations associated with the specified predominant terminal electron-accepting reactions in bottom sediments of a variety of surface water environments were: methanogenesis, 7-10 nM; sulfate reduction, 1-1.5 nM; Fe(III) reduction, 0.2 nM; Mn(IV) or nitrate reduction, less than 0.05 nM. Sediments with the same terminal electron acceptor for organic matter oxidation had comparable H2 concentrations, despite variations in the rate of organic matter decomposition, pH, and salinity. Thus, each terminal electron-accepting reaction had a unique range of steady-state H2 concentrations associated with it. Preliminary studies in a coastal plain aquifer indicated that H2 concentrations also vary in response to changes in the predominant terminal electron-accepting process in deep subsurface environments. These studies suggest that H2 measurements may aid in determining which terminal electron-accepting reactions are taking place in surface and subsurface sedimentary environments. ?? 1988.

Quasi-steady state conditions in heterogeneous aquifers during pumping tests

NASA Astrophysics Data System (ADS)

Zha, Yuanyuan; Yeh, Tian-Chyi J.; Shi, Liangsheng; Huang, Shao-Yang; Wang, Wenke; Wen, Jet-Chau

2017-08-01

Classical Thiem's well hydraulic theory, other aquifer test analyses, and flow modeling efforts often assume the existence of ;quasi-steady; state conditions. That is, while drawdowns due to pumping continue to grow, the hydraulic gradient in the vicinity of the pumping well does not change significantly. These conditions have built upon two-dimensional and equivalent homogeneous conceptual models, but few field data have been available to affirm the existence of these conditions. Moreover, effects of heterogeneity and three-dimensional flow on this quasi-steady state concept have not been thoroughly investigated and discussed before. In this study, we first present a quantitative definition of quasi-steady state (or steady-shape conditions) and steady state conditions based on the analytical solution of two- or three-dimensional flow induced by pumping in unbounded, homogeneous aquifers. Afterward, we use a stochastic analysis to investigate the influence of heterogeneity on the quasi-steady state concept in heterogeneous aquifers. The results of the analysis indicate that the time to reach an approximate quasi-steady state in a heterogeneous aquifer could be quite different from that estimated based on a homogeneous model. We find that heterogeneity of aquifer properties, especially hydraulic conductivity, impedes the development of the quasi-steady state condition before the flow reaching steady state. Finally, 280 drawdown-time data from the hydraulic tomographic survey conducted at a field site corroborate our finding that the quasi-steady state condition likely would not take place in heterogeneous aquifers unless pumping tests last a long period. Research significance (1) Approximate quasi-steady and steady state conditions are defined for two- or three-dimensional flow induced by pumping in unbounded, equivalent homogeneous aquifers. (2) Analysis demonstrates effects of boundary condition, well screen interval, and heterogeneity of parameters on the existence of the quasi-steady, and validity of approximate quasi-steady concept. (3) Temporal evaluation of information content about heterogeneity in head observations are analyzed in heterogeneous aquifer. (4) 280 observed drawdown-time data corroborate the stochastic analysis that quasi-steady is difficult to reach in highly heterogeneous aquifers.

Trans-proximal tubular steady-state concentration differences studied by micro-puncture and tissue content of sodium and chloride at varying intraluminal sodium concentrations in vitro in rat kidney cortex slices: evidence for a multisite sodium transport system.

PubMed Central

Györy, A Z; Roby, H

1977-01-01

1. With the aid of micropuncture techniques, proximal tubular transepithelial concentration differences for Na (deltaC Na) and chloride (deltaC Cl) were measured in kidney cortex slices at bathing fluid Na concentrations from 10 to 400 m-mole. kg-1. Tissue content of water, Na and K was also measured in such slices. Under steady-state conditions of zero net flux of NaCl and water, deltaC Na represents the sum of active Na transport, factored by the tubular permeability coefficient added to a component of flux due to electrical forces. 2. The relation between bathing fluid Na concentraton and deltaC Na appeared sigmoid in form suggesting an allosteric mechanism for the transport step. 3. Transtubular potential difference, calculated from transepithelial Cl distribution ratios, did not appear constant at the various bathing fluid Na concentrations. Correcting for the effect of these potential differences on the value of each deltaC Na did not convert the sigmoid transport curve to a hyperbolic one, confirming the suggested allosteric nature of the active Na transport step. 4. Intracellular Na content varied linearly with bathing fluid Na concentrations implying free entry of this cation into the cell. This also suggests that the sigmoid transport curve is related to the properties of the active Na transport pump. PMID:856986

Study on Cyber Security and Threat Evaluation in SCADA Systems

DTIC Science & Technology

2012-03-01

la sécurité de l’infrastructure essentielle du Canada. DRDC CSS CR 2012-06 vii • Les cadres de gestion des cybermenaces et des ...Reine (en droit du Canada), telle que représentée par le ministre de la Défense nationale, 2012 DRDC CSS CR 2012-06 i Abstract …….. This...ii DRDC CSS CR 2012-06 Résumé …..... Le présent rapport fait la synthèse des résultats du projet PTSP 02-0347eSec

Electronic book format EPUB and Japanese typography : Mainstream people in Japan are unlikely to win international standardization battles

NASA Astrophysics Data System (ADS)

Murata, Makoto

EPUB3 is an electronic book format based on Web technologies such as HTML and CSS. EPUB3 is internationalized; in particular, it supports Japanese typography. Features such as vertical writing were introduced by first creating CSS Writing Modes and CSS Text at W3C and then creating EPUB3 at IDPF on top of them. On the basis of this standardization experience, common pitfalls for Japanese in international standardization are pointed out and a promising approach is suggested.

Polarization-selective transmission in stacked two-dimensional complementary plasmonic crystal slabs

NASA Astrophysics Data System (ADS)

Iwanaga, Masanobu

2010-02-01

It has been experimentally and numerically shown that transmission at near infrared wavelengths is selectively controlled by polarizations in two-dimensional complementary plasmonic crystal slabs (2D c-PlCSs) of stacked unit cell. This feature is naturally derived by taking account of Babinet's principle. Moreover, the slight structural modification of the unit cell has been found to result in a drastic change in linear optical responses of stacked 2D c-PlCSs. These results substantiate the feasibility of 2D c-PlCSs for producing efficient polarizers with subwavelength thickness.

Enhancing emotional-based target prediction

NASA Astrophysics Data System (ADS)

Gosnell, Michael; Woodley, Robert

2008-04-01

This work extends existing agent-based target movement prediction to include key ideas of behavioral inertia, steady states, and catastrophic change from existing psychological, sociological, and mathematical work. Existing target prediction work inherently assumes a single steady state for target behavior, and attempts to classify behavior based on a single emotional state set. The enhanced, emotional-based target prediction maintains up to three distinct steady states, or typical behaviors, based on a target's operating conditions and observed behaviors. Each steady state has an associated behavioral inertia, similar to the standard deviation of behaviors within that state. The enhanced prediction framework also allows steady state transitions through catastrophic change and individual steady states could be used in an offline analysis with additional modeling efforts to better predict anticipated target reactions.

Clinical pharmacokinetic drug interaction studies of gabapentin enacarbil, a novel transported prodrug of gabapentin, with naproxen and cimetidine

PubMed Central

Lal, Ritu; Sukbuntherng, Juthamas; Luo, Wendy; Vicente, Virna; Blumenthal, Robin; Ho, Judy; Cundy, Kenneth C

2010-01-01

AIM Gabapentin enacarbil, a transported prodrug of gabapentin, provides sustained, dose-proportional exposure to gabapentin. Unlike gabapentin, the prodrug is absorbed throughout the intestinal tract by high-capacity nutrient transporters, including mono-carboxylate transporter-1 (MCT-1). Once absorbed, gabapentin enacarbil is rapidly hydrolyzed to gabapentin, which is subsequently excreted by renal elimination via organic cation transporters (OCT2). To examine the potential for drug–drug interactions at these two transporters, the pharmacokinetics of gabapentin enacarbil were evaluated in healthy adults after administration alone or in combination with either naproxen (an MCT-1 substrate) or cimetidine (an OCT2 substrate). METHODS Subjects (n= 12 in each study) received doses of study drug until steady state was achieved; 1200 mg gabapentin enacarbil each day, followed by either naproxen (500 mg twice daily) or cimetidine (400 mg four times daily) followed by the combination. RESULTS When gabapentin enacarbil was co-administered with naproxen, gabapentin Css,max increased by, on average, 8% and AUC by, on average, 13%. When gabapentin enacarbil was co-administered with cimetidine, gabapentin AUCss increased by 24% and renal clearance of gabapentin decreased. Co-administration with gabapentin enacarbil did not affect naproxen or cimetidine exposure. Gabapentin enacarbil was generally well tolerated. CONCLUSIONS No gabapentin enacarbil dose adjustment is needed with co-administration of naproxen or cimetidine. PMID:20573085

Steady- and non-steady-state carbonate-silicate controls on atmospheric CO2

USGS Publications Warehouse

Sundquist, E.T.

1991-01-01

Two contrasting hypotheses have recently been proposed for the past long-term relation between atmospheric CO2 and the carbonate-silicate geochemical cycle. One approach (Berner, 1990) suggests that CO2 levels have varied in a manner that has maintained chemical weathering and carbonate sedimentation at a steady state with respect to tectonically controlled decarbonation reactions. A second approach (Raymo et al., 1988), applied specificlly to the late Cenozoic, suggests a decrease in CO2 caused by an uplift-induced increase in chemical weathering, without regard to the rate of decarbonation. According to the steady-state (first) hypothesis, increased weathering and carbonate sedimentation are generally associated with increasing atmospheric CO2, whereas the uplift (second) hypothesis implies decreasing CO2 under the same conditions. An ocean-atmosphere-sediment model has been used to assess the response of atmospheric CO2 and carbonate sedimentation to global perturbations in chemical weathering and decarbonation reactions. Although this assessment is theoretical and cannot yet be related to the geologic record, the model simulations compare steady-state and non-steady-state carbonate-silicate cycle response. The e-fold response time of the 'CO2-weathering' feedback mechanism is between 300 and 400 ka. The response of carbonate sedimentation is much more rapid. These response times provide a measure of the strength of steady-state assumptions, and imply that certain systematic relations are sustained throughout steady-state and non-steady-state scenarios for the carbonate-silicate cycle. The simulations suggest that feedbacks can maintain the system near a steady state, but that non-steady-state effects may contribute to long-term trends. The steady-state and uplift hypotheses are not necessarily incompatible over time scales of a few million years. ?? 1991.

Effective and absolute cross sections for low-energy (1-30 eV) electron interactions with condensed biomolecules

NASA Astrophysics Data System (ADS)

Zheng, Yi; Sanche, Léon

2018-06-01

Ionizing radiation is intensively used for therapeutic [e.g., radiotherapy, brachytherapy, and targeted radionuclide therapy (TRT)], as well as for diagnostic medical imaging purposes. In these applications, the radiation dose given to the patient should be known and controlled. In conventional cancer treatments, absorbed dose calculations rely essentially on scattering cross sections (CSs) of the primary high-energy radiation. In more sophisticated treatments, such as combined radio- and chemo-therapy, a description of the details of energy deposits at the micro- and nano-scopic level is preferred to relate dose to radiobiological effectiveness or to evaluate doses at the biomolecular level, when radiopharmaceuticals emitting short-range radiation are delivered to critical molecular components of cancer cells (e.g., TRT). These highly radiotoxic compounds emit large densities of low-energy electrons (LEEs). More generally, LEE (0-30 eV) are emitted in large numbers by any type of high-energy radiation; i.e., about 30 000 per MeV of deposited primary energy. Thus, to optimize the effectiveness of several types of radiation treatments, the energy deposited by LEEs must be known at the level of the cell, nucleus, chromosome, or DNA. Such local doses can be evaluated by Monte Carlo (MC) calculations, which account event-by-event, for the slowing down of all generations of particles. In particular, these codes require as input parameters absolute LEE CSs for elastic scattering, energy losses, and direct damage to vital cellular molecules, particularly DNA, the main target of radiation therapy. In the last decade, such CSs have emerged in the literature. Furthermore, a method was developed to transform relative yields of damages into absolute CSs by measuring specific parameters in the experiments. In this review article, we first present a general description of dose calculations in biological media via MC simulation and give an overview of the CSs available from theoretical calculations and gas-phase experiments. The properties of LEE scattering in the gas-phase are then compared to those in the condensed phase. The remaining portion of the article is devoted to condensed-phase CSs. We provide absolute LEE scattering CSs for electronic, vibrational, and phonon excitation of biomolecules as well as for dissociative electron attachment, electron intra- and inter-molecular stabilization, and bond dissociation, including strand breaks and degradation product formation. The biomolecules are O2, CO2, H2O, DNA bases, sugar and phosphate unit analogs, oligonucleotides, plasmid DNA, and the amino acid tryptophan. CSs for strand breaks in radiosensitizing and chemotherapeutic molecules bond or not to a short DNA strand are also listed. The principle of each experimental technique and mathematical methods utilized to generate all condensed-phase CSs are briefly explained. The mechanisms responsible for the magnitudes of the CSs are discussed.

Identification and Construction of Combinatory Cancer Hallmark-Based Gene Signature Sets to Predict Recurrence and Chemotherapy Benefit in Stage II Colorectal Cancer.

PubMed

Gao, Shanwu; Tibiche, Chabane; Zou, Jinfeng; Zaman, Naif; Trifiro, Mark; O'Connor-McCourt, Maureen; Wang, Edwin

2016-01-01

Decisions regarding adjuvant therapy in patients with stage II colorectal cancer (CRC) have been among the most challenging and controversial in oncology over the past 20 years. To develop robust combinatory cancer hallmark-based gene signature sets (CSS sets) that more accurately predict prognosis and identify a subset of patients with stage II CRC who could gain survival benefits from adjuvant chemotherapy. Thirteen retrospective studies of patients with stage II CRC who had clinical follow-up and adjuvant chemotherapy were analyzed. Respective totals of 162 and 843 patients from 2 and 11 independent cohorts were used as the discovery and validation cohorts, respectively. A total of 1005 patients with stage II CRC were included in the 13 cohorts. Among them, 84 of 416 patients in 3 independent cohorts received fluorouracil-based adjuvant chemotherapy. Identification of CSS sets to predict relapse-free survival and identify a subset of patients with stage II CRC who could gain substantial survival benefits from fluorouracil-based adjuvant chemotherapy. Eight cancer hallmark-based gene signatures (30 genes each) were identified and used to construct CSS sets for determining prognosis. The CSS sets were validated in 11 independent cohorts of 767 patients with stage II CRC who did not receive adjuvant chemotherapy. The CSS sets accurately stratified patients into low-, intermediate-, and high-risk groups. Five-year relapse-free survival rates were 94%, 78%, and 45%, respectively, representing 60%, 28%, and 12% of patients with stage II disease. The 416 patients with CSS set-defined high-risk stage II CRC who received fluorouracil-based adjuvant chemotherapy showed a substantial gain in survival benefits from the treatment (ie, recurrence reduced by 30%-40% in 5 years). The CSS sets substantially outperformed other prognostic predictors of stage 2 CRC. They are more accurate and robust for prognostic predictions and facilitate the identification of patients with stage II disease who could gain survival benefit from fluorouracil-based adjuvant chemotherapy.

Association of perioperative blood pressure with long-term survival in rectal cancer patients.

PubMed

Yu, Hui-Chuan; Luo, Yan-Xin; Peng, Hui; Wang, Xiao-Lin; Yang, Zi-Huan; Huang, Mei-Jin; Kang, Liang; Wang, Lei; Wang, Jian-Ping

2016-04-11

Several studies suggested that hypertension is positively related to cancer incidence and mortality. In this study, we investigated the association between perioperative blood pressure (BP) and long-term survival outcomes in patients with rectal cancer. This study included a cohort of 358 patients with stages I-III rectal cancer who underwent a curative resection between June 2007 and June 2011. Both pre- and postoperative BPs were measured, by which patients were grouped (low BP: <120/80 mmHg; high BP: ≥120/80 mmHg). The survival outcomes were compared between these two groups. The primary endpoints were disease-free survival (DFS) and cancer-specific survival (CSS). Univariate analysis showed that patients with high preoperative systolic BP had lower 3-year DFS (67.2% vs. 82.1%, P = 0.041) and CSS rates (81.9% vs. 94.8%, P = 0.003) than patients with low preoperative systolic BP, and the associations remained significant in the Cox multivariate analysis, with the adjusted hazard ratios equal to 1.97 [95% confidence interval (CI) = 1.08-3.60, P = 0.028] and 2.85 (95% CI = 1.00-8.25, P = 0.050), respectively. Similarly, in postoperative evaluation, patients with high systolic BP had significantly lower 3-year CSS rates than those with low systolic BP (78.3% vs. 88.9%, P = 0.032) in univariate analysis. Moreover, high pre- and/or postoperative systolic BP presented as risk factors for CSS in the subgroups of patients who did not have a history of hypertension, with and/or without perioperative administration of antihypertensive drugs. High preoperative systolic BP was an independent risk factor for both CSS and DFS rates, and high postoperative systolic BP was significantly associated with a low CSS rate in rectal cancer patients. Additionally, our results suggest that rectal cancer patients may get survival benefit from BP control in perioperative care. However, further studies should be conducted to determine the association between BP and CSS and targets of BP control.

On the precision of quasi steady state assumptions in stochastic dynamics

NASA Astrophysics Data System (ADS)

Agarwal, Animesh; Adams, Rhys; Castellani, Gastone C.; Shouval, Harel Z.

2012-07-01

Many biochemical networks have complex multidimensional dynamics and there is a long history of methods that have been used for dimensionality reduction for such reaction networks. Usually a deterministic mass action approach is used; however, in small volumes, there are significant fluctuations from the mean which the mass action approach cannot capture. In such cases stochastic simulation methods should be used. In this paper, we evaluate the applicability of one such dimensionality reduction method, the quasi-steady state approximation (QSSA) [L. Menten and M. Michaelis, "Die kinetik der invertinwirkung," Biochem. Z 49, 333369 (1913)] for dimensionality reduction in case of stochastic dynamics. First, the applicability of QSSA approach is evaluated for a canonical system of enzyme reactions. Application of QSSA to such a reaction system in a deterministic setting leads to Michaelis-Menten reduced kinetics which can be used to derive the equilibrium concentrations of the reaction species. In the case of stochastic simulations, however, the steady state is characterized by fluctuations around the mean equilibrium concentration. Our analysis shows that a QSSA based approach for dimensionality reduction captures well the mean of the distribution as obtained from a full dimensional simulation but fails to accurately capture the distribution around that mean. Moreover, the QSSA approximation is not unique. We have then extended the analysis to a simple bistable biochemical network model proposed to account for the stability of synaptic efficacies; the substrate of learning and memory [J. E. Lisman, "A mechanism of memory storage insensitive to molecular turnover: A bistable autophosphorylating kinase," Proc. Natl. Acad. Sci. U.S.A. 82, 3055-3057 (1985)], 10.1073/pnas.82.9.3055. Our analysis shows that a QSSA based dimensionality reduction method results in errors as big as two orders of magnitude in predicting the residence times in the two stable states.

[Computer modeling the hydrostatic pressure characteristics of the membrane potential for polymeric membrane, separated non-homogeneous electrolyte solutions].

PubMed

Slezak, Izabella H; Jasik-Slezak, Jolanta; Rogal, Mirosława; Slezak, Andrzej

2006-01-01

On the basis of model equation depending the membrane potential deltapsis, on mechanical pressure difference (deltaP), concentration polarization coefficient (zetas), concentration Rayleigh number (RC) and ratio concentration of solutions separated by membrane (Ch/Cl), the characteristics deltapsis = f(deltaP)zetas,RC,Ch/Cl for steady values of zetas, RC and Ch/Cl in single-membrane system were calculated. In this system neutral and isotropic polymeric membrane oriented in horizontal plane, the non-homogeneous binary electrolytic solutions of various concentrations were separated. Nonhomogeneity of solutions is results from creations of the concentration boundary layers on both sides of the membrane. Calculations were made for the case where on a one side of the membrane aqueous solution of NaCl at steady concentration 10(-3) mol x l(-1) (Cl) was placed and on the other aqueous solutions of NaCl at concentrations from 10(-3) mol x l(-1) to 2 x 10(-2) mol x l(-1) (Ch). Their densities were greater than NaCl solution's at 10(-3) mol x l(-1). It was shown that membrane potential depends on hydrodynamic state of a complex concentration boundary layer-membrane-concentration boundary layer, what is controlled by deltaP, Ch/Cl, RC and zetas.

Chemical Safety for Sustainability Research Action Plan 2012-2016

EPA Pesticide Factsheets

EPA’s Chemical Safety for Sustainability (CSS) research program presents the purpose, design and themes of the Agency’s CSS research efforts to ensure safety in the design, manufacture and use of existing and future chemicals

Multiple cerebral and cerebellar infarcts as the first clinical manifestation in a patient with Churg-Strauss syndrome: case report and literature review.

PubMed

Cheng, Meng-Ju; Huang, Pai-Hao; Liao, Pin-Wen; Chen, Jen-Tse; Chiang, Tsuey-Ru

2012-12-01

Churg-Strauss syndrome (CSS) is a rare autoimmune disease with small-vessel vasculitis. Neurological manifestation of CSS is common. Central nervous system is less frequently involved than that of peripheral nervous system. We report a case of 60-year-old man who presented with acute onset of right hemiparesis and impaired cognition. The presence of hypereosinophilia, asthma, sinusitis and extravascular eosinophil accumulation led to the diagnosis of Churg-Strauss syndrome. Brain magnetic resonance imaging (MRI) revealed multiple infarcts in bilateral cerebral and cerebellar hemispheres. The neurophysiology study did not reveal peripheral neuropathy. The patient was effectively treated with methylprednisolone, cyclophosphamide and warfarin. Symptoms and signs of central nervous system can be the initial neurological manifestation of CSS patients. CSS should be considered while patients have stroke and hypereosinophilia. In our patient, there is a good response to timely steroid, immunosuppressant and anticoagulant therapies.

Initial neuro-ophthalmological manifestations in Churg–Strauss syndrome

PubMed Central

Vallet, Anne-Evelyne; Didelot, Adrien; Guebre-Egziabher, Fitsum; Bernard, Martine; Mauguière, François

2010-01-01

Churg–Strauss syndrome (CSS) is a systemic vasculitis with frequent respiratory tract involvement. It can also affect the nervous system, notably the optic tract. The present work reports the case of a 65-year-old man diagnosed as having CSS in the context of several acute onset neurological symptoms including muscle weakness and signs of temporal arteritis, including bilateral anterior ischaemic optic neuropathy (ON). Electroretinograms (ERGs) and visual evoked potentials (VEPs) were performed. Flash ERGs were normal whereas VEPs were highly abnormal, showing a dramatic voltage reduction, thus confirming the ON. The vision outcome was poor. Ophthalmological presentations of CSS have rarely been reported, but no previous case of sudden blindness documented by combined ERG and VEP investigations were found in the literature. The present case strongly suggests that the occurrence of visual loss in the context of systemic inflammation with hypereosinophilia should lead to considering the diagnosis of CSS. PMID:22789694

Juvenile Churg-Strauss Syndrome as an Etiology of Myocarditis and Ischemic Stroke in Adolescents; a Case Report

PubMed Central

Moradinejad, Mohammad-Hassan; Rezaei, Amir; Ziaee, Vahid

2011-01-01

Background Churg-Strauss syndrome (CSS), a systemic vasculitis accompanied by asthma and eosinophilia, almost invariably affects the lung and is frequently associated with cutaneous involvement. It rarely has cardiac involvement. We report an unusual case of CSS with myocardial involvement and stroke. Case Presentation A 16-year old female suffered of allergic asthma for 4 years. She was under treatment with oral prednisolone and seretide inhalation. After CSS diagnosis, she developed paroxysmal atrial tachycardia. Serum levels of Troponin I and Troponin T were increased indicating massive myocardial damage probably due to myocarditis. After 5 months she developed acute hemiparesis without any evidence of ischemic or hemorrhagic event. She was treated with IVIg, intravenous pulses of methylprednisone and cyclophosphamide for each complication. Conclusion Myocarditis and stroke may also complicate CSS which should be taken in consideration for better management. PMID:23056844

Playing with data at EPA—ToxCast, ExpoCast, HTTK, and the ...

EPA Pesticide Factsheets

This is a lecture for the Emory Exposome Summer Course in Atlanta, Georgia. The focus will be on how CSS research and tools inform research on exposomics, particularly with identifying relevant chemicals and chemicals pathways from non-targeted monitoring data. This is an opportunity to reach a broad audience of researchers. There will be a live demo of the CSS Chemistry dashboard and CPcat at the end of the presentation. This is a lecture for the Emory Exposome Summer Course in Atlanta, Georgia. The focus will be on how CSS research and tools inform research on exposomics, particularly with identifying relevant chemicals and chemicals pathways from non-targeted monitoring data. This is an opportunity to reach a broad audience of researchers. There will be a live demo of the CSS Chemistry dashboard and CPcat at the end of the presentation.

The development and initial validation of the cyberchondria severity scale (CSS).

PubMed

McElroy, Eoin; Shevlin, Mark

2014-03-01

Cyberchondria is a form of anxiety characterised by excessive online health research. It may lead to increased levels of psychological distress, worry, and unnecessary medical expenses. The aim of the present study was to develop a psychometrically sound measure of this dimension. A sample of undergraduate students (N = 208; 64% female) completed a pilot version of the cyberchondria severity scale (CSS) along with the short form version of the depression, anxiety and stress scale (DASS-21). Exploratory factor analysis identified a correlated five factor structure that were labelled 'Compulsion', 'Distress', 'Excessiveness', 'Reassurance Seeking' and 'Mistrust of Medical Professional'. The CSS demonstrated good psychometric properties; the subscales had high internal consistency, along with good concurrent and convergent validity. The CSS may prove useful in a wide variety of future research activities. It may also facilitate the development and validation of interventions for cyberchondria. Copyright © 2014 Elsevier Ltd. All rights reserved.

Generalization Effects in Evaluative Conditioning: Evidence for Attitude Transfer Effects from Single Exemplars to Social Categories.

PubMed

Glaser, Tina; Kuchenbrandt, Dieta

2017-01-01

The present research investigated whether evaluatively conditioned attitudes toward members of a social category (CSs) generalize to other stimuli belonging to the same category as the CSs (generalization at the stimulus level) and to the category itself (generalization at the category level). In four experiments, USs were paired with schematic or naturalistic CSs belonging to certain fictitious groups. Afterward, attitudes toward the CSs, toward non-presented exemplars of the CS category, and toward the CS category were assessed. Results revealed evidence for generalization effects in EC on both the stimulus and the category level. Transfer effects were greater when participants' awareness of the CS-US contingency (CA) was high. Moreover, we found differences in generalization between the stimulus and category level, indicating that different processes might contribute to the effects. Theoretical and practical implications such as using EC as a tool for changing attitudes toward social groups will be discussed.

The slow and fast pyrolysis of cherry seed.

PubMed

Duman, Gozde; Okutucu, Cagdas; Ucar, Suat; Stahl, Ralph; Yanik, Jale

2011-01-01

The slow and fast pyrolysis of cherry seeds (CWS) and cherry seeds shells (CSS) was studied in fixed-bed and fluidized bed reactors at different pyrolysis temperatures. The effects of reactor type and temperature on the yields and composition of products were investigated. In the case of fast pyrolysis, the maximum bio-oil yield was found to be about 44 wt% at pyrolysis temperature of 500 °C for both CWS and CSS, whereas the bio yields were of 21 and 15 wt% obtained at 500 °C from slow pyrolysis of CWS and CSS, respectively. Both temperature and reactor type affected the composition of bio-oils. The results showed that bio-oils obtained from slow pyrolysis of CWS and CSS can be used as a fuel for combustion systems in industry and the bio-oil produced from fast pyrolysis can be evaluated as a chemical feedstock. Copyright © 2010 Elsevier Ltd. All rights reserved.

Dynamic optimization and adaptive controller design

NASA Astrophysics Data System (ADS)

Inamdar, S. R.

2010-10-01

In this work I present a new type of controller which is an adaptive tracking controller which employs dynamic optimization for optimizing current value of controller action for the temperature control of nonisothermal continuously stirred tank reactor (CSTR). We begin with a two-state model of nonisothermal CSTR which are mass and heat balance equations and then add cooling system dynamics to eliminate input multiplicity. The initial design value is obtained using local stability of steady states where approach temperature for cooling action is specified as a steady state and a design specification. Later we make a correction in the dynamics where material balance is manipulated to use feed concentration as a system parameter as an adaptive control measure in order to avoid actuator saturation for the main control loop. The analysis leading to design of dynamic optimization based parameter adaptive controller is presented. The important component of this mathematical framework is reference trajectory generation to form an adaptive control measure.

Intermittent Chaos in the Bray-Liebhafsky Oscillator. Dependence of Dynamic States on the Iodate Concentration

NASA Astrophysics Data System (ADS)

Bubanja, I. N.; Ivanović-Šašić, A.; Čupić, Ž.; Anić, S.; Kolar-Anić, Lj.

2017-12-01

Chaotic dynamic states with intermittent oscillations were generated in a Bray-Liebhafsky (BL) oscillatory reaction in an isothermal open reactor i.e., in the continuously-fed well-stirred tank reactor (CSTR) when the inflow concentration of potassium iodate was the control parameter. They are found between periodic oscillations obtained when [KIO3]0 < 3.00 × 10-2 M and stable steady states when [KIO3]0 > 4.10 × 10-2 M. It was shown that the most chaotic states obtained experimentally somewhere in the middle of this region are in high correlation with results obtained by means of largest Lyapunov exponents and phenomenological analysis based on the quantitative characteristics of intermittent oscillations.

In situ study of emerging metallicity on ion-bombarded SrTiO3 surface

NASA Astrophysics Data System (ADS)

Gross, Heiko; Bansal, Namrata; Kim, Yong-Seung; Oh, Seongshik

2011-10-01

We report how argon bombardment induces metallic states on the surface of insulating SrTiO3 at different temperatures by combining in situ conductance measurements and model calculations. At cryogenic temperatures, ionic bombardment created a thin-but much thicker than the argon-penetration depth-steady-state oxygen-vacant layer, leading to a highly-concentric metallic state. Near room temperatures, however, significant thermal diffusion occurred and the metallic state continuously diffused into the bulk, leaving only low concentration of electron carriers on the surface. Analysis of the discrepancy between the experiments and the models also provided evidence for vacancy clustering, which seems to occur during any vacancy formation process and affects the observed conductance.

Homocysteinemia control by cysteine in cerebral vascular patients after methionine loading test: evidences in physiological and pathological conditions in cerebro-vascular and multiple sclerosis patients.

PubMed

Ulivelli, Monica; Priora, Raffaella; Di Giuseppe, Danila; Coppo, Lucia; Summa, Domenico; Margaritis, Antonios; Frosali, Simona; Bartalini, Sabina; Martini, Giuseppe; Cerase, Alfonso; Di Simplicio, Paolo

2016-06-01

The toxicity risk of hyperhomocysteinemia is prevented through thiol drug administration which reduces plasma total homocysteine (tHcy) concentrations by activating thiol exchange reactions. Assuming that cysteine (Cys) is a homocysteinemia regulator, the hypothesis was verified in healthy and pathological individuals after the methionine loading test (MLT). The plasma variations of redox species of Cys, Hcy, cysteinylglycine, glutathione and albumin (reduced, HS-ALB, and at mixed disulfide, XSS-ALB) were compared in patients with cerebral small vessels disease (CSVD) (n = 11), multiple sclerosis (MS) (n = 12) and healthy controls (n = 11) at 2-4-6 h after MLT. In MLT-treated subjects, the activation of thiol exchange reactions provoked significant changes over time in redox species concentrations of Cys, Hcy, and albumin. Significant differences between controls and pathological groups were also observed. In non-methionine-treated subjects, total Cys concentrations, tHcy and thiol-protein mixed disulfides (CSS-ALB, HSS-ALB) of CSVD patients were higher than controls. After MLT, all groups displayed significant cystine (CSSC) increases and CSS-ALB decreases, that in pathological groups were significantly higher than controls. These data would confirm the Cys regulatory role on the homocysteinemia; they also explain that the Cys-Hcy mixed disulfide excretion is an important point of hyperhomocysteinemia control. Moreover, in all groups after MLT, significant increases in albumin concentrations, named total albumin (tALB) and measured as sum of HS-ALB (spectrophometric), and XSS-ALB (assayed at HPLC) were observed. tALB increases, more pronounced in healthy than in the pathological subjects, could indicate alterations of albumin equilibria between plasma and other extracellular spaces, whose toxicological consequences deserve further studies.

A simplified method for power-law modelling of metabolic pathways from time-course data and steady-state flux profiles.

PubMed

Kitayama, Tomoya; Kinoshita, Ayako; Sugimoto, Masahiro; Nakayama, Yoichi; Tomita, Masaru

2006-07-17

In order to improve understanding of metabolic systems there have been attempts to construct S-system models from time courses. Conventionally, non-linear curve-fitting algorithms have been used for modelling, because of the non-linear properties of parameter estimation from time series. However, the huge iterative calculations required have hindered the development of large-scale metabolic pathway models. To solve this problem we propose a novel method involving power-law modelling of metabolic pathways from the Jacobian of the targeted system and the steady-state flux profiles by linearization of S-systems. The results of two case studies modelling a straight and a branched pathway, respectively, showed that our method reduced the number of unknown parameters needing to be estimated. The time-courses simulated by conventional kinetic models and those described by our method behaved similarly under a wide range of perturbations of metabolite concentrations. The proposed method reduces calculation complexity and facilitates the construction of large-scale S-system models of metabolic pathways, realizing a practical application of reverse engineering of dynamic simulation models from the Jacobian of the targeted system and steady-state flux profiles.

Molecular simulation of steady-state evaporation and condensation in the presence of a non-condensable gas

NASA Astrophysics Data System (ADS)

Liang, Zhi; Keblinski, Pawel

2018-02-01

Using molecular dynamics simulations, we study evaporation and condensation of fluid Ar in the presence of a non-condensable Ne gas in a nanochannel. The evaporation and condensation are driven by the temperature difference, ΔTL, between the evaporating and condensing liquid surfaces. The steady-state evaporation and condensation fluxes (JMD) are also affected by the Ne concentration, ρNe, and the nanochannel length. We find that across a wide range of ΔTL and ρNe, JMD is in good agreement with the prediction from Stefan's law and from Schrage relationships. Furthermore, for ΔTL less than ˜20% of the absolute average temperature, we find that both steady-state heat and mass fluxes are proportional to ΔTL. This allows us to determine the interfacial resistance to the heat and mass transfer and compare it with the corresponding resistances in the gas phase. In this context, we derive an analytical expression for the effective thermal conductivity of the gas region in the nanochannel and the mass transport interfacial resistance equivalent length, i.e., the length of the nanochannel for which the resistance to the mass flow is the same as the interfacial resistance to the mass flow.

Mechanism of energy coupling to entry and exit of neutral and branched chain amino acids in membrane vesicles of Streptococcus cremoris.

PubMed

Driessen, A J; Hellingwerf, K J; Konings, W N

1987-09-15

The energetics of neutral and branched chain amino acid transport by membrane vesicles from Streptococcus cremoris have been studied with a novel model system in which beef heart mitochondrial cytochrome c oxidase functions as a proton-motive force (delta p) generating system. In the presence of reduced cytochrome c, a large delta p was generated with a maximum value at pH 6.0. Apparent H+/amino acid stoichiometries (napp) have been determined at external pH values between 5.5 and 8.0 from the steady state levels of accumulation and the delta p. For L-leucine napp (0.8) was nearly independent of the pH. For L-alanine and L-serine napp decreased from 0.9-1.0 at pH 5.5 to 0-0.2 at pH 8.0. The napp for the different amino acids decreased with increasing external amino acid concentration. At pH 6.0, first order rate constants for amino acid exit (kex) under steady state conditions for L-leucine, L-alanine, and L-serine were 1.1-1.3, 0.084, and 0.053 min-1, respectively. From the pH dependence of kex it is concluded that amino acid exit in steady state is the sum of two processes, pH-dependent carrier-mediated amino acid exit and pH-independent passive diffusion (external leak). The first order rate constant for passive diffusion increased with increasing hydrophobicity of the side chain of the amino acids. As a result of these processes the kinetic steady state attained is less than the amino acid accumulation ratio predicted by thermodynamic equilibrium. The napp determined from the steady state accumulation represents, therefore, a lower limit. It is concluded that the mechanistic stoichiometry (n) for L-leucine, L-alanine, and L-serine transport most likely equals 1.

Corticosteroids and Other Anti-Inflammatory Strategies in Pediatric Heart Surgery: A National Survey of Practice.

PubMed

Fudulu, Daniel P; Schadenberg, Alvin; Gibbison, Ben; Jenkins, Ian; Lightman, Stafford; Angelini, Gianni D; Stoica, Serban

2018-05-01

The role of steroids to mitigate the deleterious effects of pediatric cardiopulmonary bypass (CPB) remains a matter of debate; therefore, we aimed to assess preferences in administering corticosteroids (CSs) and the use of other anti-inflammatory strategies in pediatric cardiac surgery. A 19-question survey was distributed to consultants in pediatric cardiac anesthesia from 12 centers across the United Kingdom and Ireland. Of the 37 respondents (37/60, 62%), 24 (65%) use CSs, while 13 (35%) do not use steroids at all. We found variability within 5 (41%) of the 12 centers. Seven consultants (7/24, 29%) administer CSs in every case, while 17 administer CSs in selected cases only (17/24, 71%). There was variability in the dose of steroid administration. Almost all consultants (23/24, 96%) administer a single dose at induction, and one administers a two-dose regimen (1/24, 4%). There was variability in CS indications. Most consultants (24/37, 66%) use modified ultrafiltration at the conclusion of CPB. Fifteen consultants (15/32, 47%) report the use of aprotinin, while only 3 use heparin-coated circuits (3/24, 9%). We found wide variability in practice in the administration of CSs for pediatric cardiac surgery, both within and between units. While most anesthetists administer CSs in at least some cases, there is no consensus on the type of steroid, the dose, and at which patient groups this should be directed. Modified ultrafiltration is still used by most of the centers. Almost half of consultants use aprotinin, while heparin-coated circuits are infrequently used.

A comprehensive molecular study on Coffin-Siris and Nicolaides-Baraitser syndromes identifies a broad molecular and clinical spectrum converging on altered chromatin remodeling.

PubMed

Wieczorek, Dagmar; Bögershausen, Nina; Beleggia, Filippo; Steiner-Haldenstätt, Sabine; Pohl, Esther; Li, Yun; Milz, Esther; Martin, Marcel; Thiele, Holger; Altmüller, Janine; Alanay, Yasemin; Kayserili, Hülya; Klein-Hitpass, Ludger; Böhringer, Stefan; Wollstein, Andreas; Albrecht, Beate; Boduroglu, Koray; Caliebe, Almuth; Chrzanowska, Krystyna; Cogulu, Ozgur; Cristofoli, Francesca; Czeschik, Johanna Christina; Devriendt, Koenraad; Dotti, Maria Teresa; Elcioglu, Nursel; Gener, Blanca; Goecke, Timm O; Krajewska-Walasek, Malgorzata; Guillén-Navarro, Encarnación; Hayek, Joussef; Houge, Gunnar; Kilic, Esra; Simsek-Kiper, Pelin Özlem; López-González, Vanesa; Kuechler, Alma; Lyonnet, Stanislas; Mari, Francesca; Marozza, Annabella; Mathieu Dramard, Michèle; Mikat, Barbara; Morin, Gilles; Morice-Picard, Fanny; Ozkinay, Ferda; Rauch, Anita; Renieri, Alessandra; Tinschert, Sigrid; Utine, G Eda; Vilain, Catheline; Vivarelli, Rossella; Zweier, Christiane; Nürnberg, Peter; Rahmann, Sven; Vermeesch, Joris; Lüdecke, Hermann-Josef; Zeschnigk, Michael; Wollnik, Bernd

2013-12-20

Chromatin remodeling complexes are known to modify chemical marks on histones or to induce conformational changes in the chromatin in order to regulate transcription. De novo dominant mutations in different members of the SWI/SNF chromatin remodeling complex have recently been described in individuals with Coffin-Siris (CSS) and Nicolaides-Baraitser (NCBRS) syndromes. Using a combination of whole-exome sequencing, NGS-based sequencing of 23 SWI/SNF complex genes, and molecular karyotyping in 46 previously undescribed individuals with CSS and NCBRS, we identified a de novo 1-bp deletion (c.677delG, p.Gly226Glufs*53) and a de novo missense mutation (c.914G>T, p.Cys305Phe) in PHF6 in two individuals diagnosed with CSS. PHF6 interacts with the nucleosome remodeling and deacetylation (NuRD) complex implicating dysfunction of a second chromatin remodeling complex in the pathogenesis of CSS-like phenotypes. Altogether, we identified mutations in 60% of the studied individuals (28/46), located in the genes ARID1A, ARID1B, SMARCB1, SMARCE1, SMARCA2, and PHF6. We show that mutations in ARID1B are the main cause of CSS, accounting for 76% of identified mutations. ARID1B and SMARCB1 mutations were also found in individuals with the initial diagnosis of NCBRS. These individuals apparently belong to a small subset who display an intermediate CSS/NCBRS phenotype. Our proposed genotype-phenotype correlations are important for molecular screening strategies.

Expression of p53, p21 and cyclin D1 in penile cancer: p53 predicts poor prognosis.

PubMed

Gunia, Sven; Kakies, Christoph; Erbersdobler, Andreas; Hakenberg, Oliver W; Koch, Stefan; May, Matthias

2012-03-01

To evaluate the role of p53, p21 and cyclin D1 expression in patients with penile cancer (PC). Paraffin-embedded tissues from PC specimens from six pathology departments were subjected to a central histopathological review performed by one pathologist. The tissue microarray technique was used for immunostaining which was evaluated by two independent pathologists and correlated with cancer-specific survival (CSS). κ-statistics were used to assess interobserver variability. Uni- and multivariable Cox proportional hazards analysis was applied to assess the independent effects of several prognostic factors on CSS over a median of 32 months (IQR 6-66 months). Specimens and clinical data from 110 men treated surgically for primary PC were collected. p53 staining was positive in 30 and negative in 62 specimens. κ-statistics showed substantial interobserver reproducibility of p53 staining evaluation (κ=0.73; p<0.001). The 5-year CSS rate for the entire study cohort was 74%. Five-year CSS was 84% in p53-negative and 51% in p53-positive PC patients (p=0.003). Multivariable analysis showed p53 (HR=3.20; p=0.041) and pT-stage (HR=4.29; p<0.001) as independent significant prognostic factors for CSS. Cyclin D1 and p21 expression were not correlated with survival. However, incorporating p21 into a multivariable Cox model did contribute to improved model quality for predicting CSS. In patients with PC, the expression of p53 in the primary tumour specimen can be reproducibly assessed and is negatively associated with cancer specific survival.

The appropriate number of ELNs for lymph node negative breast cancer patients underwent MRM: a population-based study.

PubMed

Chi, Huiying; Zhang, Chenyue; Wang, Haiyong; Wang, Zhehai

2017-09-12

Whether number of examed lymph nodes (ELNs) would bring survival benefit for patients with negative lymph nodes after modified radical mastectomy (MRM) is uncertain. In our study, using the Surveillance Epidemiology and End Results (SEER) database between 2004 and 2009, we screened the appropriate patients with negative lymph nodes underwent MRM. The Cox proportional hazard analysis was used to determine the effect of number of ELNs on cancer specific survival (CSS). The results showed that the number of ELNs was not an independent prognostic factor on CSS ( P = 0.940). Then the X-tile mode was used to determine the appropriate threshold for ELNs count. The results showed that 9 was the appropriate cut-off point. Next, the log-rank χ 2 test was used to analyze the CSS based on different subgroup variables. The results showed that some subgroup variables including age < 50/ ≥ 50, grade I/III, AJCC T1/T2, ER positive/negative and PR positive/negative ,demonstrated significant CSS benefits among the patients with the number of ELNs ≤ 9 (all, P < 0.05). However, three subgroup variables including grade II, AJCC T3 and AJCC T4, the patients with the number of ELNs ≤ 9 did not bring significant CSS benefits (all, P > 0.1). In conclusion, our study demonstrated that the number of ELNs was not an independent prognostic factor on CSS, and 9 can be selected as the appropriate cut-off point of ELNs for patients with negative lymph nodes who underwent MRM.

Hospital-Based Program to Increase Child Safety Restraint Use among Birthing Mothers in China

PubMed Central

Chen, Xiaojun; Yang, Jingzhen; Peek-Asa, Corinne; Chen, Kangwen; Liu, Xiangxiang; Li, Liping

2014-01-01

Objective To evaluate a hospital-based educational program to increase child safety restraint knowledge and use among birthing mothers. Methods A prospective experimental and control study was performed in the Obstetrics department of hospitals. A total of 216 new birthing mothers from two hospitals (114 from intervention hospital and 102 from comparison hospital) were recruited and enrolled in the study. Intervention mothers received a height chart, an 8-minute video and a folded pamphlet regarding child safety restraint use during their hospital stay after giving birth. Evaluation data on the child safety seat (CSS) awareness, attitudes, and use were collected among both groups before and after the intervention. An additional phone interview was conducted among the intervention mothers two months after discharge. Results No significant differences existed between groups when comparing demographics. Over 90% of the intervention mothers found the educational intervention to be helpful to some extent. A significantly higher percentage of mothers in the intervention than the comparison group reported that CSS are necessary and are the safest seating practice. Nearly 20% of the intervention mothers actually purchased CSS for their babies after the intervention. While in both the intervention and comparison group, over 80% of mothers identified the ages of two through five as needing CSS, fewer than 50% of both groups identified infants as needing CSS, even after the intervention. Conclusion The results indicated that child safety restraint education implemented in hospitals helps increase birthing mothers' overall knowledge and use of CSS. Further efforts are needed to address specific age-related needs to promote car seats use among infants. PMID:25133502

Churg-Strauss syndrome: a new endotype of severe asthma? Results of 14 Turkish patients.

PubMed

Yılmaz, İnsu; Çelik, Gülfem; Aydın, Ömür; Özdemir, Seçil Kepil; Soyyiğit, Şadan; Sözener, Zeynep; Özgüçlü, Selcan; Atasoy, Çetin; Düzgün, Nurşen; Mungan, Dilşad; Sin, Betül; Demirel, Yavuz Selim; Mısırlıgil, Zeynep

2015-07-01

Churg-Strauss syndrome (CSS) is a rare multisystem vasculitis. Considering the variation of autoimmune diseases in different races, it is of interest to determine whether any outstanding features exist for Turkish patients with CSS. The aim of this study was to evaluate the clinical and serological features of the disease, the treatment, and long-term follow-up details, and to investigate possible etiological factors of Turkish CSS patients. The study included 14 patients who were diagnosed with CSS, and followed by our department between 2004 and 2012. Possible etiological factors, initial symptoms, clinical presentations, treatment, as well as outcomes were documented. The study was approved by the local ethics. All patients fulfilled the American College of Rheumatology criteria. Initial symptoms were worsening asthma (n = 14; 100%) and skin lesions (n = 6; 43%). All patients had a diagnosis of asthma and nasal polyps, whereas 57.1% had aspirin hypersensitivity at the time of diagnosis. The lungs (100%) and skin (43%) were most commonly involved. Peripheral eosinophilia dominated on initial presentations of all patients. Initial treatments included oral methyl prednisolone in all cases, whereas cyclophosphamide and azathioprine were used in three cases. Relapses were detected in five cases. None of the cases were able to stop the oral corticosteroid treatment. No fatalities were observed. We herein describe a new severe asthma endotype in connection with CSS. We suggest that physicians who deal with uncontrolled severe asthma cases should consider CSS in the presence of nasal polyps, aspirin hypersensitivity, and especially peripheral blood eosinophilia over 10%. © 2014 John Wiley & Sons Ltd.

Efficient Wideband Spectrum Sensing with Maximal Spectral Efficiency for LEO Mobile Satellite Systems

PubMed Central

Li, Feilong; Li, Zhiqiang; Li, Guangxia; Dong, Feihong; Zhang, Wei

2017-01-01

The usable satellite spectrum is becoming scarce due to static spectrum allocation policies. Cognitive radio approaches have already demonstrated their potential towards spectral efficiency for providing more spectrum access opportunities to secondary user (SU) with sufficient protection to licensed primary user (PU). Hence, recent scientific literature has been focused on the tradeoff between spectrum reuse and PU protection within narrowband spectrum sensing (SS) in terrestrial wireless sensing networks. However, those narrowband SS techniques investigated in the context of terrestrial CR may not be applicable for detecting wideband satellite signals. In this paper, we mainly investigate the problem of joint designing sensing time and hard fusion scheme to maximize SU spectral efficiency in the scenario of low earth orbit (LEO) mobile satellite services based on wideband spectrum sensing. Compressed detection model is established to prove that there indeed exists one optimal sensing time achieving maximal spectral efficiency. Moreover, we propose novel wideband cooperative spectrum sensing (CSS) framework where each SU reporting duration can be utilized for its following SU sensing. The sensing performance benefits from the novel CSS framework because the equivalent sensing time is extended by making full use of reporting slot. Furthermore, in respect of time-varying channel, the spatiotemporal CSS (ST-CSS) is presented to attain space and time diversity gain simultaneously under hard decision fusion rule. Computer simulations show that the optimal sensing settings algorithm of joint optimization of sensing time, hard fusion rule and scheduling strategy achieves significant improvement in spectral efficiency. Additionally, the novel ST-CSS scheme performs much higher spectral efficiency than that of general CSS framework. PMID:28117712

Lateral-torsional response of base-isolated buildings with curved surface sliding system subjected to near-fault earthquakes

NASA Astrophysics Data System (ADS)

Mazza, Fabio

2017-08-01

The curved surface sliding (CSS) system is one of the most in-demand techniques for the seismic isolation of buildings; yet there are still important aspects of its behaviour that need further attention. The CSS system presents variation of friction coefficient, depending on the sliding velocity of the CSS bearings, while friction force and lateral stiffness during the sliding phase are proportional to the axial load. Lateral-torsional response needs to be better understood for base-isolated structures located in near-fault areas, where fling-step and forward-directivity effects can produce long-period (horizontal) velocity pulses. To analyse these aspects, a six-storey reinforced concrete (r.c.) office framed building, with an L-shaped plan and setbacks in elevation, is designed assuming three values of the radius of curvature for the CSS system. Seven in-plan distributions of dynamic-fast friction coefficient for the CSS bearings, ranging from a constant value for all isolators to a different value for each, are considered in the case of low- and medium-type friction properties. The seismic analysis of the test structures is carried out considering an elastic-linear behaviour of the superstructure, while a nonlinear force-displacement law of the CSS bearings is considered in the horizontal direction, depending on sliding velocity and axial load. Given the lack of knowledge of the horizontal direction at which near-fault ground motions occur, the maximum torsional effects and residual displacements are evaluated with reference to different incidence angles, while the orientation of the strongest observed pulses is considered to obtain average values.

Performance analysis of different rice-based cropping systems in tropical region of Nepal.

PubMed

Pokhrel, Anil; Soni, Peeyush

2017-07-15

Energy inputs, environmental impacts and economic outputs are the main concerns in today's agricultural production systems. The current study investigated the energy, environmental and financial performances of different rice-based cropping systems (CSs). The CSs studied were: Rice-Wheat-Fallow (R-W-F), Rice-Wheat-Maize (R-W-M), Rice-Wheat-Mungbean (R-W-Mu), Rice-Lentil-Maize (R-L-M), Rice-Lentil-Mungbean (R-L-Mu), Rice-Garlic (R-G) and Rice-Onion (R-O). Primary data were collected from 210 randomly selected farms by using structured questionnaire. In this study, Data Envelopment Analysis (DEA) was used to analyze the technical efficiencies of the farms in order to estimate their energy inputs saving potential, under different CSs. Among the studied systems, R-W-M, R-L-M and R-W-Mu were found energy efficient, R-L-Mu, R-W-F and R-W-Mu were efficient considering their greenhouse gas emissions, and R-G, R-O and R-L-M were more profitable systems. Based on the combined energy, environmental and economic criteria, we conclude that R-L-M, R-L-Mu and R-W-M are the most energy, environmentally and economically efficient CSs as compared to other systems in the study. The mean technical efficiency scores of farms indicated a considerable potential of reducing energy inputs (18-34%), without compromising the economic return of the majority farms under different CSs. The results of this study support eco-efficient CSs with modern production technologies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Adjuvant radiation therapy and survival for adenoid cystic carcinoma of the breast.

PubMed

Sun, Jia-Yuan; Wu, San-Gang; Chen, Shan-Yu; Li, Feng-Yan; Lin, Huan-Xin; Chen, Yong-Xiong; He, Zhen-Yu

2017-02-01

The assess the clinical value of different types of surgical procedures and further analyze the effect of adjuvant radiation therapy (RT) for adenoid cystic carcinoma (ACC) of the breast. Patients with ACC of the breast were identified using a population-based national registration database (Surveillance, Epidemiology, and End Results, SEER). The Kaplan-Meier method and Cox regression models were performed to determine the impact of the surgical procedures and adjuvant RT associated with cause-specific survival (CSS) and overall survival (OS). A total of 478 patients with ACC of the breast were identified. The median follow-up was 59 months. The 10-year CSS and OS were 87.5% and 75.3%, respectively. For the Kaplan-Meier analysis, the 5-year CSS were 96.1%, 91.8%, 90.2%, and 94.1% in patients that received lumpectomy + adjuvant RT, lumpectomy alone, mastectomy alone, and mastectomy + adjuvant RT, respectively (p = 0.026). In the multivariate Cox analyses, lumpectomy + adjuvant RT was an independent prognostic factor for CSS and OS. Patients that received lumpectomy + adjuvant RT had better survival rates than patients that underwent lumpectomy only (CSS, p = 0.018; OS, p = 0.031) and mastectomy only (CSS, p = 0.010; OS, p = 0.004). ACC of the breast has an excellent prognosis. Breast-conserving surgery is a reasonable alternative for patients with ACC of the breast, and adjuvant RT after lumpectomy improved survival rates. Copyright © 2016 Elsevier Ltd. All rights reserved.

Sequencing the Earliest Stages of Active Galactic Nuclei Development Using The Youngest Radio Sources

NASA Astrophysics Data System (ADS)

Collier, Jordan; Filipovic, Miroslav; Norris, Ray; Chow, Kate; Huynh, Minh; Banfield, Julie; Tothill, Nick; Sirothia, Sandeep Kumar; Shabala, Stanislav

2014-04-01

This proposal is a continuation of an extensive project (the core of Collier's PhD) to explore the earliest stages of AGN formation, using Gigahertz-Peaked Spectrum (GPS) and Compact Steep Spectrum (CSS) sources. Both are widely believed to represent the earliest stages of radio-loud AGN evolution, with GPS sources preceding CSS sources. In this project, we plan to (a) test this hypothesis, (b) place GPS and CSS sources into an evolutionary sequence with a number of other young AGN candidates, and (c) search for evidence of the evolving accretion mode. We will do this using high-resolution radio observations, with a number of other multiwavelength age indicators, of a carefully selected complete faint sample of 80 GPS/CSS sources. Analysis of the C2730 ELAIS-S1 data shows that we have so far met our goals, resolving the jets of 10/49 sources, and measuring accurate spectral indices from 0.843-10 GHz. This particular proposal is to almost triple the sample size by observing an additional 80 GPS/CSS sources in the Chandra Deep Field South (arguably the best-studied field) and allow a turnover frequency - linear size relation to be derived at >10-sigma. Sources found to be unresolved in our final sample will subsequently be observed with VLBI. Comparing those sources resolved with ATCA to the more compact sources resolved with VLBI will give a distribution of source sizes, helping to answer the question of whether all GPS/CSS sources grow to larger sizes.

Development of a clinical spasticity scale for evaluation of dogs with chronic thoracolumbar spinal cord injury.

PubMed

Lewis, Melissa J; Olby, Natasha J

2017-07-01

OBJECTIVE To develop a spasticity scale for dogs with chronic deficits following severe spinal cord injury (SCI) for use in clinical assessment and outcome measurement in clinical trials. ANIMALS 20 chronically paralyzed dogs with a persistent lack of hind limb pain perception caused by an acute SCI at least 3 months previously. PROCEDURES Spasticity was assessed in both hind limbs via tests of muscle tone, clonus, and flexor and extensor spasms adapted from human scales. Measurement of patellar clonus duration and flexor spasm duration and degree was feasible. These components were used to create a canine spasticity scale (CSS; overall score range, 0 to 18). Temporal variation for individual dogs and interrater reliability were evaluated. Gait was quantified with published gait scales, and CSS scores were compared with gait scores and clinical variables. Owners were questioned regarding spasticity observed at home. RESULTS 20 dogs were enrolled: 18 with no apparent hind limb pain perception and 2 with blunted responses; 5 were ambulatory. Testing was well tolerated, and scores were repeatable between raters. Median overall CSS score was 7 (range, 3 to 11), and flexor spasms were the most prominent finding. Overall CSS score was not associated with age, SCI duration, lesion location, or owner-reported spasticity. Overall CSS score and flexor spasm duration were associated with gait scores. CONCLUSIONS AND CLINICAL RELEVANCE The CSS could be used to quantify hind limb spasticity in dogs with chronic thoracolumbar SCI and might be a useful outcome measure. Flexor spasms may represent an integral part of stepping in dogs with severe SCI.

Observation versus adjuvant radiation or chemotherapy in the management of stage I seminoma: clinical outcomes and prognostic factors for relapse in a large US cohort.

PubMed

Soper, Margaret S; Hastings, Joseph R; Cosmatos, Harry A; Slezak, Jeffrey M; Wang, Ricardo; Lodin, Kenneth

2014-08-01

The management of stage I seminoma has evolved over the past 20 years. Contemporary management options after orchiectomy include adjuvant radiation, adjuvant chemotherapy, and observation. This analysis defines the experience at Kaiser Permanente Southern California from 1990 to 2010. We examined outcomes for stage I seminoma patients and reviewed prognostic factors for recurrence in those managed with observation. This is a retrospective study of 502 stage I seminoma patients who underwent orchiectomy from 1990 to 2010. Outcomes examined were relapse-free survival (RFS), overall survival (OS), and cause-specific survival (CSS). Risk factors for recurrence evaluated were age, preoperative hCG elevation, preoperative LDH elevation, tumor size, lymphovascular invasion, rete testis invasion, epididymis invasion, and invasion through the tunica albuginea. Among radiation patients, 5-year RFS was 97.2%, OS was 98.0%, and CSS was 99.3%. Among chemotherapy patients, 2-year RFS was 98.3% and OS and CSS were 100%. Among observation patients, 5-year RFS was 89.2%, OS was 98.8%, and CSS was 100%. There was no difference in OS or CSS among the groups. RFS was significantly lower for observation patients. Among observation patients, univariate analysis identified tumor size, lymphovascular invasion, and rete testis invasion as risk factors for relapse. No factors were significant on multivariate analysis. Our data show that adjuvant radiation and chemotherapy yield similar outcomes in the management of stage I seminoma. Observation results in a lower RFS, but patients who relapse can be salvaged; OS and CSS are not affected.

Classifier Subset Selection for the Stacked Generalization Method Applied to Emotion Recognition in Speech

PubMed Central

Álvarez, Aitor; Sierra, Basilio; Arruti, Andoni; López-Gil, Juan-Miguel; Garay-Vitoria, Nestor

2015-01-01

In this paper, a new supervised classification paradigm, called classifier subset selection for stacked generalization (CSS stacking), is presented to deal with speech emotion recognition. The new approach consists of an improvement of a bi-level multi-classifier system known as stacking generalization by means of an integration of an estimation of distribution algorithm (EDA) in the first layer to select the optimal subset from the standard base classifiers. The good performance of the proposed new paradigm was demonstrated over different configurations and datasets. First, several CSS stacking classifiers were constructed on the RekEmozio dataset, using some specific standard base classifiers and a total of 123 spectral, quality and prosodic features computed using in-house feature extraction algorithms. These initial CSS stacking classifiers were compared to other multi-classifier systems and the employed standard classifiers built on the same set of speech features. Then, new CSS stacking classifiers were built on RekEmozio using a different set of both acoustic parameters (extended version of the Geneva Minimalistic Acoustic Parameter Set (eGeMAPS)) and standard classifiers and employing the best meta-classifier of the initial experiments. The performance of these two CSS stacking classifiers was evaluated and compared. Finally, the new paradigm was tested on the well-known Berlin Emotional Speech database. We compared the performance of single, standard stacking and CSS stacking systems using the same parametrization of the second phase. All of the classifications were performed at the categorical level, including the six primary emotions plus the neutral one. PMID:26712757

A prospective, multisite, international validation of the Complex Regional Pain Syndrome Severity Score.

PubMed

Harden, R Norman; Maihofner, Christian; Abousaad, Elias; Vatine, Jean-Jacques; Kirsling, Amy; Perez, Roberto S G M; Kuroda, Maxine; Brunner, Florian; Stanton-Hicks, Michael; Marinus, Johan; van Hilten, Jacobus J; Mackey, Sean; Birklein, Frank; Schlereth, Tanja; Mailis-Gagnon, Angela; Graciosa, Joe; Connoly, Sara B; Dayanim, David; Massey, Michael; Frank, Hadas; Livshitz, Anatoly; Bruehl, Stephen

2017-08-01

Clinical diagnosis of complex regional pain syndrome (CRPS) is a dichotomous (yes/no) categorization, a format necessary for clinical decision making. Such dichotomous diagnostic categories do not convey an individual's subtle gradations in the severity of the condition over time and have poor statistical power when used as an outcome measure in research. This prospective, international, multicenter study slightly modified and further evaluated the validity of the CRPS Severity Score (CSS), a continuous index of CRPS severity. Using a prospective design, medical evaluations were conducted in 156 patients with CRPS to compare changes over time in CSS scores between patients initiating a new treatment program and patients on stable treatment regimens. New vs stable categorizations were supported by greater changes in pain and function in the former. Results indicated that CSS values in the stable CRPS treatment group exhibited much less change over time relative to the new treatment group, with intraclass correlations nearly twice as large in the former. A calculated smallest real difference value revealed that a change in the CSS of ≥4.9 scale points would indicate real differences in CRPS symptomatology (with 95% confidence). Across groups, larger changes in CRPS features on the CSS over time were associated in the expected direction with greater changes in pain intensity, fatigue, social functioning, ability to engage in physical roles, and general well-being. The overall pattern of findings further supports the validity of the CSS as a measure of CRPS severity and suggests it may prove useful in clinical monitoring and outcomes research.

Constraining Regolith Production on a Hillslope Over Long Timescales: Interpreting In Situ 10Be Concentrations on an Evolving Landscape

NASA Astrophysics Data System (ADS)

Foster, M. A.; Anderson, R. S.; Duehnforth, M.; Kelly, P. J.

2011-12-01

In situ produced 10Be cosmogenic radionuclide (CRN) concentrations provide geomorphologists with a quantitative tool to calculate regolith production rates in a variety of landscapes. However, the power of CRN dating is limited by the care with which these hard-earned numbers are interpreted. As rock is exhumed through the weathered zone, it accumulates in situ produced CRNs. Most studies assume a steady-state condition to calculate regolith production rates from 10Be concentrations obtained from rock at the base of mobile regolith; ignoring decay, the regolith production rate becomes simply Poe-H/z*/[10Be]. Although the balance of regolith production and the spatial pattern of divergence required to maintain steady regolith thickness is valid in some landscapes, steady-state is unlikely on hillslopes where time scales for generating soils are longer than climatic cycles. We report in situ 10Be concentrations to calculate production rates for mobile regolith in 8 soil pits along north- and south-facing slopes in Gordon Gulch, an intensively studied catchment in the Boulder Creek CZO. Gordon Gulch hillslopes exhibit variable regolith and saprolite thicknesses over gneissic and granitic parent rock; mean regolith thickness is 0.65 m. Local denudation rates in nearby catchments are 25 ± 8 m/Ma (Dethier and Lazarus, 2006). The mean residence time of mobile regolith in Gordon Gulch catchment is therefore 20-45 ka; less than half of this time is spent in Holocene climatic conditions. Although Gordon Gulch presently has mean annual temperature (MAT) ~4°C, it was likely at least 6°C cooler during the Last Glacial Maximum, meaning that periglacial conditions likely dominated. We therefore anticipate that parent rock could be more rapidly damaged by increased frost-cracking, and regolith transport be enhanced by increased frost-heave; thus steady-state conditions cannot be assumed over this timescale. To develop strategies for interpretation of 10Be, we employ a 1D numerical hillslope model in which regolith thickness and 10Be concentration are tracked at all hillslope positions. 10Be concentration in rock immediately subjacent to the regolith is updated both by decay and by production at a rate governed by the instantaneous regolith thickness (e.g. Riggins et al., 2011). Vertically averaged 10Be concentration in the regolith is updated by vertically averaged production rate, decay, addition from rock released at the base of the regolith, and advection of regolith. The resulting field of 10Be in bedrock at the regolith interface, from which one deduces long term average regolith production rates, varies both in time and in space. Our model indicates that regolith thickness fluctuates by tens of percent from the average condition over the timescale of glacial-interglacial cycles. The resulting shifts in 10Be concentrations at the base of regolith are of similar magnitude, with greater shifts of 10Be concentrations in regolith. We will employ this model tuned to the Gordon Gulch sites to interpret measured 10Be concentrations.

Influence of fast alpha diffusion and thermal alpha buildup on tokamak reactor performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Uckan, N.A.; Tolliver, J.S.; Houlberg, W.A.

1987-11-01

The effect of fast alpha diffusion and thermal alpha accumulation on the confinement capability of a candidate Engineering Test Reactor (ETR) plasma (Tokamak Ignition/Burn Experimental Reactor (TIBER-II)) in achieving ignition and steady-state driven operation has been assessed using both global and 1-1/2-D transport models. Estimates are made of the threshold for radial diffusion of fast alphas and thermal alpha buildup. It is shown that a relatively low level of radial transport, when combined with large gradients in the fast alpha density, leads to a significant radial flow with a deleterious effect on plasma performance. Similarly, modest levels of thermal alphamore » concentration significantly influence the ignition and steady-state burn capability. 23 refs., 9 figs., 4 tabs.« less

Ultra-long pharmacokinetic properties of insulin degludec are comparable in elderly subjects and younger adults with type 1 diabetes mellitus.

PubMed

Korsatko, S; Deller, S; Mader, J K; Glettler, K; Koehler, G; Treiber, G; Urschitz, M; Wolf, M; Hastrup, H; Søndergaard, F; Haahr, H; Pieber, T R

2014-01-01

Management of diabetes in elderly subjects is complex and careful management of glucose levels is of particular importance in this population because of an increased risk of diabetes-related complications and hypoglycaemia. The aim of this study was to evaluate the pharmacokinetic and pharmacodynamic properties of insulin degludec (IDeg), a basal insulin with an ultra-long duration of action, in elderly subjects with type 1 diabetes compared with younger adults. This trial was a randomised, double-blind, two-period, crossover trial conducted in a single centre and included both inpatient and outpatient periods. Subjects were men and women aged 18-35 years inclusive (younger adult group) or ≥65 years (elderly group) with type 1 diabetes who received IDeg (0.4 U/kg) via subcutaneous injection in the thigh once-daily for six days. Following 6-day dosing, a 26-hour euglycaemic glucose clamp procedure was conducted to evaluate the steady-state pharmacodynamic effects of IDeg. Blood samples were taken for pharmacokinetic analysis up to 120 h post-dose. Pharmacokinetic endpoints included the total exposure of IDeg, ie the area under the IDeg serum concentration curve during one dosing interval at steady state (AUC(IDeg,τ,SS)) (τ = 0-24 h, equal to one dosing interval) and the maximum IDeg serum concentration at steady state (C(max,IDeg,SS)). Pharmacodynamic endpoints included the total glucose-lowering effect of IDeg, ie the area under the glucose infusion rate (GIR) curve at steady state (AUC(GIR,τ,SS)), and the maximum GIR at steady state (GIR(max,IDeg,SS)). Total exposure (AUC(IDeg,τ,SS)) and maximum concentration (C(max,IDeg,SS)) of IDeg were comparable between elderly subjects and younger adults. Estimated mean age group ratios (elderly/younger adult) for AUC(IDeg,τ,SS) and C(max,IDeg,SS) and corresponding two-sided 95 % confidence intervals (CIs) were 1.04 (95 % CI 0.73-1.47) and 1.02 (95 % CI 0.74-1.39), respectively. Mean AUC(IDeg,0-12h,SS)/AUC(IDeg,τ,SS) was 53 % in both younger adult and elderly subjects, showing that in both age groups IDeg exposure was evenly distributed across the first and second 12 h of the 24-hour dosing interval. No statistically significant differences were observed between younger adult and elderly subjects with regard to AUC(GIR,τ,SS) (the primary endpoint of this study) and GIR(max,IDeg,SS). Estimated mean age group ratios (elderly/younger adult) for AUC(GIR,τ,SS) and GIR(max,IDeg,SS) and corresponding two-sided 95 % CIs were 0.78 (95 % CI 0.47-1.31) and 0.80 (95 % CI 0.54-1.17), respectively. Duration of action was beyond the clamp duration of 26 h in all subjects. The exposure of IDeg at steady state during once-daily dosing was similar in younger adult and elderly subjects. The glucose-lowering effect of IDeg was numerically lower in elderly subjects compared with younger adults, but no significant differences were observed between age groups. The ultra-long pharmacokinetic and pharmacodynamic properties of IDeg observed in younger adults were preserved in elderly subjects with type 1 diabetes. Clinical trials.gov number: NCT00964418.

Steady States, Fluctuation-Dissipation Theorems and Homogenization for Reversible Diffusions in a Random Environment

NASA Astrophysics Data System (ADS)

Mathieu, P.; Piatnitski, A.

2018-04-01

Prolongating our previous paper on the Einstein relation, we study the motion of a particle diffusing in a random reversible environment when subject to a small external forcing. In order to describe the long time behavior of the particle, we introduce the notions of steady state and weak steady state. We establish the continuity of weak steady states for an ergodic and uniformly elliptic environment. When the environment has finite range of dependence, we prove the existence of the steady state and weak steady state and compute its derivative at a vanishing force. Thus we obtain a complete `fluctuation-dissipation Theorem' in this context as well as the continuity of the effective variance.

Patterns of misuse of child safety seats

DOT National Transportation Integrated Search

1996-01-01

This project addressed the patterns of child safety seat (CSS) misuse in the nation and reported on the most appropriate techniques to accurately and efficiently collect these data. CSS use and misuse observations were collected for about 5,900 targe...

Army Strategic Logistics Plan: Enabling Strategic Responsiveness Through a Revolution in Military Logistics

DTIC Science & Technology

2002-01-01

D-5 AAN CSS Franchise Report...D-6 CSS Franchise Issues Summary for TDAPII...Appendix D. The ASLP groups the initiatives in the six investment categories of automation and communications, business process change, organizational

Steady state volcanism - Evidence from eruption histories of polygenetic volcanoes

NASA Technical Reports Server (NTRS)

Wadge, G.

1982-01-01

Cumulative volcano volume curves are presented as evidence for steady-state behavior at certain volcanoes and to develop a model of steady-state volcanism. A minimum criteria of five eruptions over a year was chosen to characterize a steady-state volcano. The subsequent model features a constant head of magmatic pressure from a reservoir supplied from depth, a sawtooth curve produced by the magma arrivals or discharge from the subvolcanic reservoir, large volume eruptions with long repose periods, and conditions of nonsupply of magma. The behavior of Mts. Etna, Nyamuragira, and Kilauea are described and show continuous levels of plasma output resulting in cumulative volume increases. Further discussion is made of steady-state andesitic and dacitic volcanism, long term patterns of the steady state, and magma storage, and the lack of a sufficient number of steady-state volcanoes in the world is taken as evidence that further data is required for a comprehensive model.

Modeling non-steady state radioisotope transport in the vadose zone--A case study using uranium isotopes at Pena Blanca, Mexico

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ku, T. L.; Luo, S.; Goldstein, S. J.

2009-06-01

Current models using U- and Th-series disequilibria to study radioisotope transport in groundwater systems mostly consider a steady-state situation. These models have limited applicability to the vadose zone (UZ) where the concentration and migratory behavior of radioisotopes in fluid are often transitory. We present here, as a first attempt of its kind, a model simulating the non-steady state, intermittent fluid transport in vadose layers. It provides quantitative constraints on in-situ migration of dissolved and colloidal radioisotopes in terms of retardation factor and rock-water interaction (or water transit) time. For uranium, the simulation predicts that intermittent flushing in the UZ leadsmore » to a linear relationship between reciprocal U concentration and {sup 234}U/{sup 238}U ratio in percolating waters, with the intercept and slope bearing information on the rates of dissolution and {alpha}-recoil of U isotopes, respectively. The general validity of the model appears to be borne out by the measurement of uranium isotopes in UZ waters collected at various times over a period during 1995-2006 from a site in the Pena Blanca mining district, Mexico, where the Nopal I uranium deposit is located. Enhanced {sup 234}U/{sup 238}U ratios in vadose-zone waters resulting from lengthened non-flushing time as prescribed by the model provide an interpretative basis for using {sup 234}U/{sup 238}U in cave calcites to reconstruct the regional changes in hydrology and climate. We also provide a theoretical account of the model's potential applications using radium isotopes.« less

Modeling non-steady state radioisotope transport in the vadose zone - A case study using uranium isotopes at Peña Blanca, Mexico

NASA Astrophysics Data System (ADS)

Ku, T. L.; Luo, S.; Goldstein, S. J.; Murrell, M. T.; Chu, W. L.; Dobson, P. F.

2009-10-01

Current models using U- and Th-series disequilibria to study radioisotope transport in groundwater systems mostly consider a steady-state situation. These models have limited applicability to the vadose zone (UZ) where the concentration and migratory behavior of radioisotopes in fluid are often transitory. We present here, as a first attempt of its kind, a model simulating the non-steady state, intermittent fluid transport in vadose layers. It provides quantitative constraints on in-situ migration of dissolved and colloidal radioisotopes in terms of retardation factor and rock-water interaction (or water transit) time. For uranium, the simulation predicts that intermittent flushing in the UZ leads to a linear relationship between reciprocal U concentration and 234U/ 238U ratio in percolating waters, with the intercept and slope bearing information on the rates of dissolution and α-recoil of U isotopes, respectively. The general validity of the model appears to be borne out by the measurement of uranium isotopes in UZ waters collected at various times over a period during 1995-2006 from a site in the Peña Blanca mining district, Mexico, where the Nopal I uranium deposit is located. Enhanced 234U/ 238U ratios in vadose-zone waters resulting from lengthened non-flushing time as prescribed by the model provide an interpretative basis for using 234U/ 238U in cave calcites to reconstruct the regional changes in hydrology and climate. We also provide a theoretical account of the model's potential applications using radium isotopes.

Numerical simulation of the dielectrophoretic concentration of DNA particles and the effect of AC electroosmosis

NASA Astrophysics Data System (ADS)

Loucaides, N. G.; Georghiou, G. E.; Charalambous, C. D.

2007-04-01

The dielectrophoretic concentration of DNA particles suspended in a solution is investigated in a system of parallel electrodes, where the particles are attracted to the edges of the electrodes by positive dielectrophoresis. The AC electroosmotic motion of the fluid is also considered, as well as the diffusion of the particles, using the solution of the Smoluchowski equation. The results examine the effect of AC electroosmosis in steady state dielectrophoretic concentration of particles, by demonstrating that AC electroosmosis significantly reduces the dielectrophoretic concentration at the edges and moves the particles towards the electrode centres.

Interrelations between cerebrospinal fluid and plasma inorganic ions and glucose in patients with chronic renal failure.

PubMed Central

Pye, I F; Aber, G M

1982-01-01

The concentrations of inorganic ions and glucose in the plasma and CSF of 11 patients with "steady-state" chronic renal failure have been measured and their CSF: plasma interrelations studied. The results have been compared with the corresponding data from 34 control subjects. In the patients with renal failure, there was a positive correlation between raised CSF and plasma potassium concentrations. In contrast to the impaired potassium homeostasis, normal CSF magnesium and calcium concentrations were observed despite wide variations in the plasma concentrations of these ions. PMID:7085915

Regular expansion solutions for small Peclet number heat or mass transfer in concentrated two-phase particulate systems

NASA Technical Reports Server (NTRS)

Yaron, I.

1974-01-01

Steady state heat or mass transfer in concentrated ensembles of drops, bubbles or solid spheres in uniform, slow viscous motion, is investigated. Convective effects at small Peclet numbers are taken into account by expanding the nondimensional temperature or concentration in powers of the Peclet number. Uniformly valid solutions are obtained, which reflect the effects of dispersed phase content and rate of internal circulation within the fluid particles. The dependence of the range of Peclet and Reynolds numbers, for which regular expansions are valid, on particle concentration is discussed.

Altered plasma pharmacokinetics of ceftiofur hydrochloride in cows affected with severe clinical mastitis.

PubMed

Gorden, P J; Kleinhenz, M D; Wulf, L W; KuKanich, B; Lee, C J; Wang, C; Coetzee, J F

2016-01-01

Mastitis is a frequent problem among dairy cows, reducing milk yield and increasing cull rates. Systemic therapy with the cephalosporin antimicrobial ceftiofur hydrochloride (CEF) may improve therapeutic outcomes, but the incidence of CEF violative residues has increased annually since 2011. One potential explanation is that disease status may alter the pharmacokinetics (PK) of CEF. To test this hypothesis, we compared the plasma PK of CEF in healthy cows with those with severe endotoxic mastitis. Eight cows with naturally occurring mastitis and 8 clinically healthy cows were treated with 2.2 mg of CEF per kilogram of body weight once daily for 5d via the intramuscular route. Blood was collected at 0, 0.33, 0.67, 1, 1.5, 2, 3, 4, 8, 16, and 24h after the first CEF administration and every 8h thereafter until 120 h after the final dose. Plasma samples were analyzed for CEF concentrations using liquid chromatography coupled with mass spectrometry. With the exception of time 0, CEF was detected at all time points. The disease group had a significantly higher plasma CEF concentration at t=3h after the first injection and a significantly lower plasma concentration from 40 to 152 h following the first injection, with the exception of the t=64 h time point. Data following the first injection (time 0-24 h) were fit to a single-dose, noncompartmental PK model. This model indicated that the disease group had a shorter plasma half-life. A multidose, noncompartmental model was used to determine steady-state PK. Compared with control cows, the disease group had an initially higher peak concentration and a higher volume of distribution and drug clearance rates. The disease group also had a lower area under the curve per dosing interval, steady-state concentration maximum, and dose-adjusted peak steady-state concentration. All other PK parameters were not different between the 2 groups. Altered PK, as suggested by this trial, may contribute to an increased risk for the development of a violative residue in meat. Further research is needed to more completely characterize drug distribution in diseased cattle and to study the effect of coadministration of other drugs on drug distribution. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Chronic ethanol use in alcoholic beverages by HIV-infected patients affects the therapeutic window of stavudine, lamivudine and nevirapine during the 9-month follow-up period: using chronic alcohol-use biomarkers.

PubMed

Bbosa, Godfrey S; Kyegombe, David B; Anokbonggo, William W; Ogwal-Okeng, Jasper; Musoke, David; Odda, John; Lubega, Aloysius; Ntale, Muhammad

2014-01-27

Abstract Background: Chronic ethanol use is a global problem including among HIV-infected patients on stavudine/lamivudine/nevirapine (d4T/3TC/NVP) regimen. The study determined the effect of chronic ethanol use on the therapeutic window of d4T, 3TC and NVP in HIV-infected patients using alcohol-use biomarkers to screen patients for chronic ethanol use. Methods: A case-control study using repeated measures design with serial measurements was used to quantify drugs in plasma. The WHO alcohol use disorder identification test (AUDIT) tool was initially used to screen patients for chronic alcohol use, and then they were further sorted using alcohol-use bioamarkers (γ-glutamyl transferase ≥55.0 IU; mean corpuscular volume, ≥96 fl, aspartate amino transferase/alanine aminotransferase ratio ≥2.0 value). A total of 41 patients (26 in the alcohol group and 15 in the control group) were followed up for 9 months with blood sampling done at 3-month intervals. Plasma drug concentrations were quantified using a Shimadzu Class-VP™ HPLC data system version 6.1. Data was analyzed using SAS 2003 version 9.1 statistical package with repeated measures fixed model. Means were compared using Student's t-test. Results: The mean steady-state plasma drug concentrations of d4T and 3TC in the alcohol group were lower than that in the control group during the 9-month period of follow-up. For 3TC, there was a statistical difference in the mean steady-state plasma drug concentrations between the alcohol group and the control group (p≤0.05) in the 6- and 9-month period of follow-up. For NVP, in both groups they were within the reference ranges, although the drug plasma concentrations were higher in the alcohol group compared to the control group and were statistically significant (p<0.05) in 0, 3 and 6 months of follow-up. Conclusions: Chronic ethanol use by HIV-infected patients reduced the therapeutic steady-state plasma drug concentrations of d4T and 3TC and increased the NVP drug concentrations in the HIV-infected patients.