Effect of hemoglobin- and Perflubron-based oxygen carriers on common clinical laboratory tests.

PubMed

Ma, Z; Monk, T G; Goodnough, L T; McClellan, A; Gawryl, M; Clark, T; Moreira, P; Keipert, P E; Scott, M G

1997-09-01

Polymerized hemoglobin solutions (Hb-based oxygen carriers; HBOCs) and a second-generation perfluorocarbon (PFC) emulsion (Perflubron) are in clinical trials as temporary oxygen carriers ("blood substitutes"). Plasma and serum samples from patients receiving HBOCs look markedly red, whereas those from patients receiving PFC appear to be lipemic. Because hemolysis and lipemia are well-known interferents in many assays, we examined the effects of these substances on clinical chemistry, immunoassay, therapeutic drug, and coagulation tests. HBOC concentrations up to 50 g/L caused essentially no interference for Na, K, Cl, urea, total CO2, P, uric acid, Mg, creatinine, and glucose values determined by the Hitachi 747 or Vitros 750 analyzers (or both) or for immunoassays of lidocaine, N-acetylprocainamide, procainamide, digoxin, phenytoin, quinidine, or theophylline performed on the Abbott AxSym or TDx. Gentamycin and vancomycin assays on the AxSym exhibited a significant positive and negative interference, respectively. Immunoassays for TSH on the Abbott IMx and for troponin I on the Dade Stratus were unaffected by HBOC at this concentration. Tests for total protein, albumin, LDH, AST, ALT, GGT, amylase, lipase, and cholesterol were significantly affected to various extents at different HBOC concentrations on the Hitachi 747 and Vitros 750. The CK-MB assay on the Stratus exhibited a negative interference at 5 g/L HBOC. HBOC interference in coagulation tests was method-dependent-fibrometer-based methods on the BBL Fibro System were free from interference, but optical-based methods on the MLA 1000C exhibited interferences at 20 g/L HBOC. A 1:20 dilution of the PFC-based oxygen carrier (600 g/L) caused no interference on any of these chemistry or immunoassay tests except for amylase and ammonia on the Vitros 750 and plasma iron on the Hitachi 747.

Interference of oxygen, carbon dioxide, and water vapor on the analysis for oxides of nitrogen by chemiluminescence

NASA Technical Reports Server (NTRS)

Maahs, H. G.

1975-01-01

The interference of small concentrations (less than 4 percent by volume) of oxygen, carbon dioxide, and water vapor on the analysis for oxides of nitrogen by chemiluminescence was measured. The sample gas consisted primarily of nitrogen, with less than 100 parts per million concentration of nitric oxide, and with small concentrations of oxygen, carbon dioxide, and water vapor added. Results obtained under these conditions indicate that although oxygen does not measurably affect the analysis for nitric oxide, the presence of carbon dioxide and water vapor causes the indicated nitric oxide concentration to be too low. An interference factor - defined as the percentage change in indicated nitric oxide concentration (relative to the true nitric oxide concentration) divided by the percent interfering gas present - was determined for carbon dioxide to be -0.60 + or - 0.04 and for water vapor to be -2.1 + or - 0.3.

77 FR 49386 - Airworthiness Directives; Airbus Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-16

... prompted by reports of silicon particles inside the oxygen generator manifolds, which had chafed from the... the part number and serial number of each passenger oxygen container, replacing the oxygen generator manifold of the affected oxygen container with a serviceable manifold, and performing an operational check...

Manipulation of Microenvironment with a Built-in Electrochemical Actuator in Proximity of a Dissolved Oxygen Microsensor

NASA Technical Reports Server (NTRS)

Kim, Chang-Soo; Lee, Cae-Hyang; Fiering, Jason O.; Ufer, Stefan; Scarantino, Charles W.; Nagle, H. Troy; Fiering, Jason O.; Ufer, Stefan; Nagle, H. Troy; Scarantino, Charles W.

2004-01-01

Abstract - Biochemical sensors for continuous monitoring require dependable periodic self- diagnosis with acceptable simplicity to check its functionality during operation. An in situ self- diagnostic technique for a dissolved oxygen microsensor is proposed in an effort to devise an intelligent microsensor system with an integrated electrochemical actuation electrode. With a built- in platinum microelectrode that surrounds the microsensor, two kinds of microenvironments, called the oxygen-saturated or oxygen-depleted phases, can be created by water electrolysis depending on the polarity. The functionality of the microsensor can be checked during these microenvironment phases. The polarographic oxygen microsensor is fabricated on a flexible polyimide substrate (Kapton) and the feasibility of the proposed concept is demonstrated in a physiological solution. The sensor responds properly during the oxygen-generating and oxygen- depleting phases. The use of these microenvironments for in situ self-calibration is discussed to achieve functional integration as well as structural integration of the microsensor system.

40 CFR 90.320 - Carbon dioxide analyzer calibration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (64 percent) is required (see following table). Example calibration points (%) Acceptable for... periodic interference, system check, and calibration test procedures specified in 40 CFR part 1065...

40 CFR 90.320 - Carbon dioxide analyzer calibration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... (64 percent) is required (see following table). Example calibration points (%) Acceptable for... periodic interference, system check, and calibration test procedures specified in 40 CFR part 1065...

40 CFR 90.320 - Carbon dioxide analyzer calibration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... (64 percent) is required (see following table). Example calibration points (%) Acceptable for... periodic interference, system check, and calibration test procedures specified in 40 CFR part 1065...

40 CFR 91.320 - Carbon dioxide analyzer calibration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (64 percent) is required (see following table). Example calibration points (percent) Acceptable for...) The initial and periodic interference, system check, and calibration test procedures specified in 40...

40 CFR 91.320 - Carbon dioxide analyzer calibration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... (64 percent) is required (see following table). Example calibration points (percent) Acceptable for...) The initial and periodic interference, system check, and calibration test procedures specified in 40...

40 CFR 91.320 - Carbon dioxide analyzer calibration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... (64 percent) is required (see following table). Example calibration points (percent) Acceptable for...) The initial and periodic interference, system check, and calibration test procedures specified in 40...

40 CFR 91.320 - Carbon dioxide analyzer calibration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... required (see following table). Example calibration points (percent) Acceptable for calibration? 20, 30, 40... periodic interference, system check, and calibration test procedures specified in 40 CFR part 1065...

Pressure Measurements Using an Airborne Differential Absorption Lidar. Part 1; Analysis of the Systematic Error Sources

NASA Technical Reports Server (NTRS)

Flamant, Cyrille N.; Schwemmer, Geary K.; Korb, C. Laurence; Evans, Keith D.; Palm, Stephen P.

1999-01-01

Remote airborne measurements of the vertical and horizontal structure of the atmospheric pressure field in the lower troposphere are made with an oxygen differential absorption lidar (DIAL). A detailed analysis of this measurement technique is provided which includes corrections for imprecise knowledge of the detector background level, the oxygen absorption fine parameters, and variations in the laser output energy. In addition, we analyze other possible sources of systematic errors including spectral effects related to aerosol and molecular scattering interference by rotational Raman scattering and interference by isotopic oxygen fines.

Pulse Oximetry

MedlinePlus

... carrying. By using a small device called a pulse oximeter , your blood oxygen level can be checked without ... and “Oxygen Therapy for Children”) How does a pulse oximeter work? A pulse oximeter comes either as a ...

Measurement of Oxygen A Band Line Parameters by Using Modulation Spectroscopy with Higher Harmonic Detection

NASA Technical Reports Server (NTRS)

Dharamsi, Amin

1999-01-01

Wavelength modulation spectroscopy is used to demonstrate that extremely weak absorption lines can be measured even when these lines suffer from interference from the wings of adjacent stronger lines. It is shown that the use of detection at several harmonics allows such interference to be examined clearly and conveniently. The results of experimental measurements on a weak magnetic dipole driven, spin-forbidden line in the oxygen A band, which experiences interference from the wings of a pair of adjacent lines towards the blue and red regions of line center, are presented. A comparison of the experimental results to theory is given.

Membrane oxygenator heat exchanger failure detected by unique blood gas findings.

PubMed

Hawkins, Justin L

2014-03-01

Failure of components integrated into the cardiopulmonary bypass circuit, although rare, can bring about catastrophic results. One of these components is the heat exchanger of the membrane oxygenator. In this compartment, unsterile water from the heater cooler device is separated from the sterile blood by stainless steel, aluminum, or by polyurethane. These areas are glued or welded to keep the two compartments separate, maintaining sterility of the blood. Although quality control testing is performed by the manufacturer at the factory level, transport presents the real possibility for damage. Because of this, each manufacturer has included in the instructions for use a testing procedure for testing the integrity of the heat exchanger component. Water is circulated through the heat exchanger before priming and a visible check is made of the oxygenator bundle to check for leaks. If none are apparent, then priming of the oxygenator is performed. In this particular case, this procedure was not useful in detecting communication between the water and blood chambers of the oxygenator.

Minimizing the effects of oxygen interference on l-lactate sensors by a single amino acid mutation in Aerococcus viridansl-lactate oxidase.

PubMed

Hiraka, Kentaro; Kojima, Katsuhiro; Lin, Chi-En; Tsugawa, Wakako; Asano, Ryutaro; La Belle, Jeffrey T; Sode, Koji

2018-04-30

l-lactate biosensors employing l-lactate oxidase (LOx) have been developed mainly to measure l-lactate concentration for clinical diagnostics, sports medicine, and the food industry. Some l-lactate biosensors employ artificial electron mediators, but these can negatively impact the detection of l-lactate by competing with the primary electron acceptor: molecular oxygen. In this paper, a strategic approach to engineering an AvLOx that minimizes the effects of oxygen interference on sensor strips was reported. First, we predicted an oxygen access pathway in Aerococcus viridans LOx (AvLOx) based on its crystal structure. This was subsequently blocked by a bulky amino acid substitution. The resulting Ala96Leu mutant showed a drastic reduction in oxidase activity using molecular oxygen as the electron acceptor and a small increase in dehydrogenase activity employing an artificial electron acceptor. Secondly, the Ala96Leu mutant was immobilized on a screen-printed carbon electrode using glutaraldehyde cross-linking method. Amperometric analysis was performed with potassium ferricyanide as an electron mediator under argon or atmospheric conditions. Under argon condition, the response current increased linearly from 0.05 to 0.5mM l-lactate for both wild-type and Ala96Leu. However, under atmospheric conditions, the response of wild-type AvLOx electrode was suppressed by 9-12% due to oxygen interference. The Ala96Leu mutant maintained 56-69% of the response current at the same l-lactate level and minimized the relative bias error to -19% from -49% of wild-type. This study provided significant insight into the enzymatic reaction mechanism of AvLOx and presented a novel approach to minimize oxygen interference in sensor applications, which will enable accurate detection of l-lactate concentrations. Copyright © 2017 Elsevier B.V. All rights reserved.

An Oxidase-Based Electrochemical Fluidic Sensor with High-Sensitivity and Low-Interference by On-Chip Oxygen Manipulation

PubMed Central

Radhakrishnan, Nitin; Park, Jongwon; Kim, Chang-Soo

2012-01-01

Utilizing a simple fluidic structure, we demonstrate the improved performance of oxidase-based enzymatic biosensors. Electrolysis of water is utilized to generate bubbles to manipulate the oxygen microenvironment close to the biosensor in a fluidic channel. For the proper enzyme reactions to occur, a simple mechanical procedure of manipulating bubbles was developed to maximize the oxygen level while minimizing the pH change after electrolysis. The sensors show improved sensitivities based on the oxygen dependency of enzyme reaction. In addition, this oxygen-rich operation minimizes the ratio of electrochemical interference signal by ascorbic acid during sensor operation (i.e., amperometric detection of hydrogen peroxide). Although creatinine sensors have been used as the model system in this study, this method is applicable to many other biosensors that can use oxidase enzymes (e.g., glucose, alcohol, phenol, etc.) to implement a viable component for in-line fluidic sensor systems. PMID:23012527

Investigation of intrinsic defect magnetic properties in wurtzite ZnO materials

NASA Astrophysics Data System (ADS)

Fedorov, A. S.; Visotin, M. A.; Kholtobina, A. S.; Kuzubov, A. A.; Mikhaleva, N. S.; Hsu, Hua Shu

2017-10-01

Theoretical and experimental investigations of the ferromagnetism induced by intrinsic defects inside wurtzite zinc oxide structures are performed using magnetic field-dependent circular dichroism (MCD-H), direct magnetization measurement (M-H) by superconducting quantum interference device (SQUID) as well as by generalized gradient density functional theory (GGA-DFT). To investigate localized magnetic moments of bulk material intrinsic defects - vacancies, interstitial atoms and Frenkel defects, various-size periodic supercells are calculated. It is shown that oxygen interstitial atoms (Oi) or zinc vacancies (Znv) generate magnetic moments of 1,98 и 1,26 μB respectively, however, the magnitudes are significantly reduced when the distance between defects increases. At the same time, the magnetic moments of oxygen Frenkel defects are large ( 1.5-1.8 μB) and do not depend on the distance between the defects. It is shown that the origin of the induced ferromagnetism in bulk ZnO is the extra spin density on the oxygen atoms nearest to the defect. Also dependence of the magnetization of ZnO (10 1 ̅ 0) and (0001) thin films on the positions of Oi and Znv in subsurface layers were investigated and it is shown that the magnetic moments of both defects are significantly different from the values inside bulk material. In order to check theoretical results regarding the defect induced ferromagnetism in ZnO, two thin films doped by carbon (C) and having Zn interstitials and oxygen vacancies were prepared and annealed in vacuum and air, respectively. According to the MCD-H and M-H measurements, the film, which was annealed in air, exhibits a ferromagnetic behavior, while the other does not. One can assume annealing of ZnO in vacuum should create oxygen vacancies or Zn interstitial atoms. At that annealing of the second C:ZnO film in air leads to essential magnetization, probably by annihilation of oxygen vacancies, formation of interstitial oxygen atoms or zinc vacancies. Thus, our experimental results confirm our theoretical conclusions that ZnO magnetization origin are Oi or Znv defects.

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

Koch, T.H.

Coumarin laser dyes upon excitation degrade to produce products that absorb at the lasing wavelength. This results in attenuation of dye laser output through interference of stimulated emission. The roles of singlet oxygen and excitation intensity on dye degradation were explored. Singlet oxygen is formed but its reactions with the dye do not appear to be a major cause of dye laser output deterioration. High light intensity results in dye-sensitized, solvent oligomerization to yield materials that interfere with dye-stimulated emission. 1, 4-Diazabicyclo2,2,2octane (DABCO)inhibits this oligomerization.

Method and apparatus for checking the stability of a setup for making reflection type holograms

NASA Technical Reports Server (NTRS)

Lackner, H. G. (Inventor)

1974-01-01

A method and apparatus are described for checking the stability of a setup for recording reflection-type (white light) holograms. Two sets of interference fringes are simultaneously obtained, one giving information about coherence and stability of the setup alone and the other demonstrating coherence of the entire system, including the holographic recording plate. Special emphasis is given to the stability of the plate, due to the fact that any minute vibration might severely degrade or completely destroy the recording.

Use of the Ames Check Standard Model for the Validation of Wall Interference Corrections

NASA Technical Reports Server (NTRS)

Ulbrich, N.; Amaya, M.; Flach, R.

2018-01-01

The new check standard model of the NASA Ames 11-ft Transonic Wind Tunnel was chosen for a future validation of the facility's wall interference correction system. The chosen validation approach takes advantage of the fact that test conditions experienced by a large model in the slotted part of the tunnel's test section will change significantly if a subset of the slots is temporarily sealed. Therefore, the model's aerodynamic coefficients have to be recorded, corrected, and compared for two different test section configurations in order to perform the validation. Test section configurations with highly accurate Mach number and dynamic pressure calibrations were selected for the validation. First, the model is tested with all test section slots in open configuration while keeping the model's center of rotation on the tunnel centerline. In the next step, slots on the test section floor are sealed and the model is moved to a new center of rotation that is 33 inches below the tunnel centerline. Then, the original angle of attack sweeps are repeated. Afterwards, wall interference corrections are applied to both test data sets and response surface models of the resulting aerodynamic coefficients in interference-free flow are generated. Finally, the response surface models are used to predict the aerodynamic coefficients for a family of angles of attack while keeping dynamic pressure, Mach number, and Reynolds number constant. The validation is considered successful if the corrected aerodynamic coefficients obtained from the related response surface model pair show good agreement. Residual differences between the corrected coefficient sets will be analyzed as well because they are an indicator of the overall accuracy of the facility's wall interference correction process.

Determination of Biochemical Oxygen Demand of Area Waters: A Bioassay Procedure for Environmental Monitoring

ERIC Educational Resources Information Center

Riehl, Matthew

2012-01-01

A graphical method for determining the 5-day biochemical oxygen demand (BOD5) for a body of water is described. In this bioassay, students collect a sample of water from a designated site, transport it to the laboratory, and evaluate the amount of oxygen consumed by naturally occurring bacteria during a 5-day incubation period. An accuracy check,…

Technical evaluation of the novel preanalytical module on instrumentation laboratory ACL TOP: advancing automation in hemostasis testing.

PubMed

Lippi, Giuseppe; Ippolito, Luigi; Favaloro, Emmanuel J

2013-10-01

Automation in hemostasis testing is entering an exciting and unprecedented phase. This study was planned to assess the performance of the new preanalytical module on the hemostasis testing system Instrumentation Laboratory ACL TOP. The evaluation included interference studies to define reliable thresholds for rejecting samples with significant concentrations of interfering substances; within-run imprecision studies of plasma indices on four different interference degrees for each index; comparison studies with reference measures of hemolysis index, bilirubin, and triglycerides on clinical chemistry analyzers; and calculation of turnaround time with and without automatic performance of preanalytical check. The upper limits for sample rejection according to our interference studies were 3.6 g/L for hemoglobin, 13.6 mg/dL for bilirubin, and 1454 mg/dL for triglycerides. We found optimal precision for all indices (0.6% to 3.1% at clinically relevant thresholds) and highly significant correlations with reference measures on clinical chemistry analyzers (from 0.985 to 0.998). The limited increase of turnaround time (i.e., +3% and +5% with or without cap-piercing), coupled with no adjunctive costs over performance of normal coagulation assays, contribute to make the automatic check of plasma indices on ACL TOP a reliable and practical approach for improving testing quality and safeguarding patient safety.

DETAIL OF THE LIQUID HYDROGEN AND LIQUID OXYGEN VENT VALVES, ...

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

DETAIL OF THE LIQUID HYDROGEN AND LIQUID OXYGEN VENT VALVES, SIXTH LEVEL OF THE EXTERNAL TANK CHECK-OUT CELLS, HB-2, FACING NORTHEAST - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

75 FR 6854 - Airworthiness Directives; Dassault-Aviation Model Falcon 900EX Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-12

... and passenger Right-Hand (RH) oxygen lines may both interfere with the frame 8 of the aeroplane structure. A subsequent design review of the oxygen lines routing has confirmed that, on certain aeroplanes, equipped in RH mid-cabin with a 115 cu-ft oxygen cylinder, the installation of the line support assembly at...

FIVQ algorithm for interference hyper-spectral image compression

NASA Astrophysics Data System (ADS)

Wen, Jia; Ma, Caiwen; Zhao, Junsuo

2014-07-01

Based on the improved vector quantization (IVQ) algorithm [1] which was proposed in 2012, this paper proposes a further improved vector quantization (FIVQ) algorithm for LASIS (Large Aperture Static Imaging Spectrometer) interference hyper-spectral image compression. To get better image quality, IVQ algorithm takes both the mean values and the VQ indices as the encoding rules. Although IVQ algorithm can improve both the bit rate and the image quality, it still can be further improved in order to get much lower bit rate for the LASIS interference pattern with the special optical characteristics based on the pushing and sweeping in LASIS imaging principle. In the proposed algorithm FIVQ, the neighborhood of the encoding blocks of the interference pattern image, which are using the mean value rules, will be checked whether they have the same mean value as the current processing block. Experiments show the proposed algorithm FIVQ can get lower bit rate compared to that of the IVQ algorithm for the LASIS interference hyper-spectral sequences.

Oxygen disorder, a way to accommodate large epitaxial strains in oxides

DOE PAGES

Zhang, Yu Yang; Mishra, Rohan; Pennycook, Timothy J.; ...

2015-09-22

Density-functional calculations (total-energy comparisons) and checks for negative-frequency phonon modes are employed as a stability indicator to show that, in rutile- and fluorite-structure oxides, e.g., zirconia strained by a strontium titanate substrate, oxygen-sublattice disorder can be the energetically preferred way to accommodate strain.

40 CFR 91.325 - Analyzer interference checks.

Code of Federal Regulations, 2011 CFR

2011-07-01

... concern for CLD (and HCLD) analyzers are CO2 and water vapor. Quench responses to these two gases are... calculations.) (ii) Calculations for water quench must consider dilution of the NO span gas with water vapor and scaling of the water vapor concentration of the mixture to that expected during testing. Determine...

40 CFR 91.325 - Analyzer interference checks.

Code of Federal Regulations, 2014 CFR

2014-07-01

... concern for CLD (and HCLD) analyzers are CO2 and water vapor. Quench responses to these two gases are... calculations.) (ii) Calculations for water quench must consider dilution of the NO span gas with water vapor and scaling of the water vapor concentration of the mixture to that expected during testing. Determine...

40 CFR 91.325 - Analyzer interference checks.

Code of Federal Regulations, 2013 CFR

2013-07-01

... concern for CLD (and HCLD) analyzers are CO2 and water vapor. Quench responses to these two gases are... calculations.) (ii) Calculations for water quench must consider dilution of the NO span gas with water vapor and scaling of the water vapor concentration of the mixture to that expected during testing. Determine...

40 CFR 91.325 - Analyzer interference checks.

Code of Federal Regulations, 2010 CFR

2010-07-01

... concern for CLD (and HCLD) analyzers are CO2 and water vapor. Quench responses to these two gases are... calculations.) (ii) Calculations for water quench must consider dilution of the NO span gas with water vapor and scaling of the water vapor concentration of the mixture to that expected during testing. Determine...

40 CFR 91.325 - Analyzer interference checks.

Code of Federal Regulations, 2012 CFR

2012-07-01

... concern for CLD (and HCLD) analyzers are CO2 and water vapor. Quench responses to these two gases are... calculations.) (ii) Calculations for water quench must consider dilution of the NO span gas with water vapor and scaling of the water vapor concentration of the mixture to that expected during testing. Determine...

40 CFR 89.320 - Carbon monoxide analyzer calibration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... monoxide as described in this section. (b) Initial and periodic interference check. Prior to its... engineering practice. For each range calibrated, if the deviation from a least-squares best-fit straight line... range. If the deviation exceeds these limits, the best-fit non-linear equation which represents the data...

40 CFR 89.320 - Carbon monoxide analyzer calibration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... monoxide as described in this section. (b) Initial and periodic interference check. Prior to its... engineering practice. For each range calibrated, if the deviation from a least-squares best-fit straight line... range. If the deviation exceeds these limits, the best-fit non-linear equation which represents the data...

40 CFR 89.320 - Carbon monoxide analyzer calibration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... monoxide as described in this section. (b) Initial and periodic interference check. Prior to its... engineering practice. For each range calibrated, if the deviation from a least-squares best-fit straight line... range. If the deviation exceeds these limits, the best-fit non-linear equation which represents the data...

40 CFR 89.320 - Carbon monoxide analyzer calibration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... monoxide as described in this section. (b) Initial and periodic interference check. Prior to its... engineering practice. For each range calibrated, if the deviation from a least-squares best-fit straight line... range. If the deviation exceeds these limits, the best-fit non-linear equation which represents the data...

Integrated Heat Switch/Oxide Sorption Compressor

NASA Technical Reports Server (NTRS)

Bard, Steven

1989-01-01

Thermally-driven, nonmechanical compressor uses container filled with compressed praseodymium cerium oxide powder (PrCeOx) to provide high-pressure flow of oxygen gas for driving closed-cycle Joule-Thomson-expansion refrigeration unit. Integrated heat switch/oxide sorption compressor has no moving parts except check valves, which control flow of oxygen gas between compressor and closed-cycle Joule-Thomson refrigeration system. Oxygen expelled from sorbent at high pressure by evacuating heat-switch gap and turning on heater.

How to Design a Biosensor

PubMed Central

Ward, W. Kenneth

2007-01-01

Amperometric sensors for continuous glucose monitoring could prevent acute and chronic complications of diabetes, but research is needed to improve accuracy and stability. In designing sensors, interference from non-glucose analytes can be minimized by use of filtration membranes or electron transfer mediators that allow polarization at low potentials. If oxygen is required for the enzymatic reaction with glucose, then the outer permselective membrane must have substantial oxygen permeability. For this reason, during development of permselective membranes, permeability studies (such as performed by Tipnis and colleagues in this issue) can be used to measure transport of glucose and oxygen and optimize membrane structure. Tipnis and colleagues present a novel biosensor based with separate layers for glucose-oxygen permselectivity, enzymatic conversion, and avoidance of interference. They also address sensor stability, in part by comparing sensor function during ascending vs descending glucose levels. By measuring the difference, they were able to minimize this aspect of instability (hysterisis), which assisted them in selecting a promising permselective membrane based on iron and humic acid. PMID:19888407

How to design a biosensor.

PubMed

Ward, W Kenneth

2007-03-01

Amperometric sensors for continuous glucose monitoring could prevent acute and chronic complications of diabetes, but research is needed to improve accuracy and stability. In designing sensors, interference from non-glucose analytes can be minimized by use of filtration membranes or electron transfer mediators that allow polarization at low potentials. If oxygen is required for the enzymatic reaction with glucose, then the outer permselective membrane must have substantial oxygen permeability. For this reason, during development of permselective membranes, permeability studies (such as performed by Tipnis and colleagues in this issue) can be used to measure transport of glucose and oxygen and optimize membrane structure. Tipnis and colleagues present a novel biosensor based with separate layers for glucose-oxygen permselectivity, enzymatic conversion, and avoidance of interference. They also address sensor stability, in part by comparing sensor function during ascending vs descending glucose levels. By measuring the difference, they were able to minimize this aspect of instability (hysterisis), which assisted them in selecting a promising permselective membrane based on iron and humic acid.

Cyanotic heart disease

MedlinePlus

... by checking it through the skin with a pulse oximeter Complete blood count (CBC) ECG (electrocardiogram) Looking at ... from the groin ( cardiac catheterization ) Transcutaneous oxygen monitor (pulse oximeter) Echo-Doppler

A two-dimensional adaptive-wall test section with ventilated walls in the Ames 2- by 2-foot transonic wind tunnel

NASA Technical Reports Server (NTRS)

Schairer, Edward T.; Lee, George; Mcdevitt, T. Kevin

1989-01-01

The first tests conducted in the adaptive-wall test section of the Ames Research Center's 2- by 2-Foot Transonic Wind Tunnel are described. A procedure was demonstrated for reducing wall interference in transonic flow past a two-dimensional airfoil by actively controlling flow through the slotted walls of the test section. Flow through the walls was controlled by adjusting pressures in compartments of plenums above and below the test section. Wall interference was assessed by measuring (with a laser velocimeter) velocity distributions along a contour surrounding the model, and then checking those measurements for their compatibility with free-air far-field boundary conditions. Plenum pressures for minimum wall interference were determined from empirical influence coefficients. An NACA 0012 airfoil was tested at angles of attach of 0 and 2, and at Mach numbers between 0.70 and 0.85. In all cases the wall-setting procedure greatly reduced wall interference. Wall interference, however, was never completely eliminated, primarily because the effect of plenum pressure changes on the velocities along the contour could not be accurately predicted.

40 CFR 86.1324-84 - Carbon dioxide analyzer calibration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... calibrated, if the deviation from a least-squares best-fit straight line is within ±2 percent or less of the... exceeds these limits, then the best-fit non-linear equation which represents the data within these limits shall be used to determine concentration values. (d) The initial and periodic interference, system check...

40 CFR 89.322 - Carbon dioxide analyzer calibration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... engineering practice. For each range calibrated, if the deviation from a least-squares best-fit straight line... range. If the deviation exceeds these limits, the best-fit non-linear equation which represents the data... interference, system check, and calibration test procedures specified in 40 CFR part 1065 may be used in lieu...

40 CFR 86.1324-84 - Carbon dioxide analyzer calibration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... calibrated, if the deviation from a least-squares best-fit straight line is within ±2 percent or less of the... exceeds these limits, then the best-fit non-linear equation which represents the data within these limits shall be used to determine concentration values. (d) The initial and periodic interference, system check...

40 CFR 86.1324-84 - Carbon dioxide analyzer calibration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... calibrated, if the deviation from a least-squares best-fit straight line is within ±2 percent or less of the... exceeds these limits, then the best-fit non-linear equation which represents the data within these limits shall be used to determine concentration values. (d) The initial and periodic interference, system check...

40 CFR 89.322 - Carbon dioxide analyzer calibration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... engineering practice. For each range calibrated, if the deviation from a least-squares best-fit straight line... range. If the deviation exceeds these limits, the best-fit non-linear equation which represents the data... interference, system check, and calibration test procedures specified in 40 CFR part 1065 may be used in lieu...

40 CFR 86.1323-84 - Oxides of nitrogen analyzer calibration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... calibrated, if the deviation from a least-squares best-fit straight line is within ±2 percent of the value at... exceeds these limits, then the best-fit non-linear equation which represents the data within these limits shall be used to determine concentration values. (c) The initial and periodic interference, system check...

40 CFR 86.1323-84 - Oxides of nitrogen analyzer calibration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... calibrated, if the deviation from a least-squares best-fit straight line is within ±2 percent of the value at... exceeds these limits, then the best-fit non-linear equation which represents the data within these limits shall be used to determine concentration values. (c) The initial and periodic interference, system check...

40 CFR 89.322 - Carbon dioxide analyzer calibration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... engineering practice. For each range calibrated, if the deviation from a least-squares best-fit straight line... range. If the deviation exceeds these limits, the best-fit non-linear equation which represents the data... interference, system check, and calibration test procedures specified in 40 CFR part 1065 may be used in lieu...

40 CFR 89.322 - Carbon dioxide analyzer calibration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... engineering practice. For each range calibrated, if the deviation from a least-squares best-fit straight line... range. If the deviation exceeds these limits, the best-fit non-linear equation which represents the data... interference, system check, and calibration test procedures specified in 40 CFR part 1065 may be used in lieu...

Design and analysis of DNA strand displacement devices using probabilistic model checking

PubMed Central

Lakin, Matthew R.; Parker, David; Cardelli, Luca; Kwiatkowska, Marta; Phillips, Andrew

2012-01-01

Designing correct, robust DNA devices is difficult because of the many possibilities for unwanted interference between molecules in the system. DNA strand displacement has been proposed as a design paradigm for DNA devices, and the DNA strand displacement (DSD) programming language has been developed as a means of formally programming and analysing these devices to check for unwanted interference. We demonstrate, for the first time, the use of probabilistic verification techniques to analyse the correctness, reliability and performance of DNA devices during the design phase. We use the probabilistic model checker prism, in combination with the DSD language, to design and debug DNA strand displacement components and to investigate their kinetics. We show how our techniques can be used to identify design flaws and to evaluate the merits of contrasting design decisions, even on devices comprising relatively few inputs. We then demonstrate the use of these components to construct a DNA strand displacement device for approximate majority voting. Finally, we discuss some of the challenges and possible directions for applying these methods to more complex designs. PMID:22219398

Design and performance investigation of LDPC-coded upstream transmission systems in IM/DD OFDM-PONs

NASA Astrophysics Data System (ADS)

Gong, Xiaoxue; Guo, Lei; Wu, Jingjing; Ning, Zhaolong

2016-12-01

In Intensity-Modulation Direct-Detection (IM/DD) Orthogonal Frequency Division Multiplexing Passive Optical Networks (OFDM-PONs), aside from Subcarrier-to-Subcarrier Intermixing Interferences (SSII) induced by square-law detection, the same laser frequency for data sending from Optical Network Units (ONUs) results in ONU-to-ONU Beating Interferences (OOBI) at the receiver. To mitigate those interferences, we design a Low-Density Parity Check (LDPC)-coded and spectrum-efficient upstream transmission system. A theoretical channel model is also derived, in order to analyze the detrimental factors influencing system performances. Simulation results demonstrate that the receiver sensitivity is improved 3.4 dB and 2.5 dB under QPSK and 8QAM, respectively, after 100 km Standard Single-Mode Fiber (SSMF) transmission. Furthermore, the spectrum efficiency can be improved by about 50%.

[Ambient air interference in oxygen intake measurements in liquid incubating media with the use of open polarographic cells].

PubMed

Miniaev, M V; Voronchikhina, L I

2007-01-01

A model of oxygen intake by aerobic bio-objects in liquid incubating media was applied to investigate the influence air-media interface area on accuracy of measuring the oxygen intake and error value. It was shown that intrusion of air oxygen increases the relative error to 24% in open polarographic cells and to 13% in cells with a reduced interface area. Results of modeling passive media oxygenation laid a basis for proposing a method to reduce relative error by 66% for open cells and by 15% for cells with a reduced interface area.

Hyperviscosity - newborn

MedlinePlus

... called a hematocrit . Other tests may include: Blood gases to check oxygen level in the blood Blood ... 2018, A.D.A.M., Inc. Duplication for commercial use must be authorized in writing by ADAM ...

Oxygen Sensing Based on the Yellowing of Newspaper.

PubMed

Yu, Jingjing; Qin, Xingcai; Xian, Xiaojun; Tao, Nongjian

2018-01-26

Newspaper is known to turn yellow over time. We show here that this yellowing process is sensitive to oxygen when exposed to UV light, leading to oxygen sensing. Oxygen sensing is critical to many applications, including industrial process control and breath analysis, but the existing oxygen sensors have limitations, especially for breath analysis that operates at 100% humidity. The UV irradiation also triggers fluorescence emission from newspaper, and the fluorescence intensity depends on oxygen concentration, providing an additional oxygen sensing method. Newspaper is stable in ambient air, and reactive to oxygen only with UV activation, which overcomes the instability issue of a typical colorimetric sensor in ambient air. The newspaper oxygen sensor works in 100% relative humidity air, containing various interferents. These unique properties of newspaper promise low cost and reliable oxygen sensing applications.

High Electrochemical Sensitivity of TiO2- x Nanosheets and an Electron-Induced Mutual Interference Effect toward Heavy Metal Ions Demonstrated Using X-ray Absorption Fine Structure Spectra.

PubMed

Zhou, Wen-Yi; Li, Shan-Shan; Song, Jie-Yao; Jiang, Min; Jiang, Tian-Jia; Liu, Jin-Yun; Liu, Jin-Huai; Huang, Xing-Jiu

2018-04-03

Mutual interference is a severe issue that occurs during the electrochemical detection of heavy metal ions. This limitation presents a notable drawback for its high sensitivity to specific targets. Here, we present a high electrochemical sensitivity of ∼237.1 μA cm -2 μM -1 toward copper(II) [Cu(II)] based on oxygen-deficient titanium dioxide (TiO 2- x ) nanosheets. We fully demonstrated an atomic-level relationship between electrochemical behaviors and the key factors, including the high-energy (001) facet percentage, oxygen vacancy concentration, surface -OH content, and charge carrier density, is fully demonstrated. These four factors were quantified using Raman, electron spin resonance, X-ray photoelectron spectroscopy spectra, and Mott-Schottky plots. In the mutual interference investigation, we selected cadmium(II) [Cd(II)] as the target ion because of the significant difference in its stripping potential (∼700 mV). The results show that the Cd(II) can enhance the sensitivity of TiO 2- x nanosheets toward Cu(II), exhibiting an electron-induced mutual interference effect, as demonstrated by X-ray absorption fine structure spectra.

Voltages induced by lightning strokes and ground-faults on a coaxial telecom circuit enclosed inside a composite earthwire. Part II: lightning induced voltages ant composite earthwire tehnical design

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

Anzanel, P.; Kouteynikoff, P.

1985-02-01

This Part II presents theorical and experimental work about interference generated by lightning strokes in a telecommunication coaxial circuit enclosed inside a composite earthwire for overhead transmission lines. Sinusoidal steady state and surge measurements of the composite earthwire susceptibility to interference (transfer impedance) have been carried out. Induced voltages have been calculated using an original double sampling FFT method whose validity has been checked by measurements on a test line. Finally, it is shown how the cable design can be improved and maximum induced voltage values are given.

40 CFR 1065.362 - Non-stoichiometric raw exhaust FID O2 interference verification.

Code of Federal Regulations, 2013 CFR

2013-07-01

... air source during testing, use zero air as the FID burner's air source for this verification. (4) Zero the FID analyzer using the zero gas used during emission testing. (5) Span the FID analyzer using a span gas that you use during emission testing. (6) Check the zero response of the FID analyzer using...

40 CFR 89.321 - Oxides of nitrogen analyzer calibration.

Code of Federal Regulations, 2014 CFR

2014-07-01

...-fit straight line is 2 percent or less of the value at each non-zero data point and within ± 0.3... factor for that range. If the deviation exceeds these limits, the best-fit non-linear equation which... periodic interference, system check, and calibration test procedures specified in 40 CFR part 1065 may be...

40 CFR 89.321 - Oxides of nitrogen analyzer calibration.

Code of Federal Regulations, 2013 CFR

2013-07-01

...-fit straight line is 2 percent or less of the value at each non-zero data point and within ± 0.3... factor for that range. If the deviation exceeds these limits, the best-fit non-linear equation which... periodic interference, system check, and calibration test procedures specified in 40 CFR part 1065 may be...

40 CFR 89.321 - Oxides of nitrogen analyzer calibration.

Code of Federal Regulations, 2012 CFR

2012-07-01

...-fit straight line is 2 percent or less of the value at each non-zero data point and within ± 0.3... factor for that range. If the deviation exceeds these limits, the best-fit non-linear equation which... periodic interference, system check, and calibration test procedures specified in 40 CFR part 1065 may be...

40 CFR 89.321 - Oxides of nitrogen analyzer calibration.

Code of Federal Regulations, 2011 CFR

2011-07-01

...-fit straight line is 2 percent or less of the value at each non-zero data point and within ± 0.3... factor for that range. If the deviation exceeds these limits, the best-fit non-linear equation which... periodic interference, system check, and calibration test procedures specified in 40 CFR part 1065 may be...

Unintended inhalation of nitric oxide by contamination of compressed air: physiologic effects and interference with intended nitric oxide inhalation in acute lung injury.

PubMed

Benzing, A; Loop, T; Mols, G; Geiger, K

1999-10-01

Compressed air from a hospital's central gas supply may contain nitric oxide as a result of air pollution. Inhaled nitric oxide may increase arterial oxygen tension and decrease pulmonary vascular resistance in patients with acute lung injury and acute respiratory distress syndrome. Therefore, the authors wanted to determine whether unintentional nitric oxide inhalation by contamination of compressed air influences arterial oxygen tension and pulmonary vascular resistance and interferes with the therapeutic use of nitric oxide. Nitric oxide concentrations in the compressed air of a university hospital were measured continuously by chemiluminescence during two periods (4 and 2 weeks). The effects of unintended nitric oxide inhalation on arterial oxygen tension (n = 15) and on pulmonary vascular resistance (n = 9) were measured in patients with acute lung injury and acute respiratory distress syndrome by changing the source of compressed air of the ventilator from the hospital's central gas supply to a nitric oxide-free gas tank containing compressed air. In five of these patients, the effects of an additional inhalation of 5 ppm nitric oxide were evaluated. During working days, compressed air of the hospital's central gas supply contained clinically effective nitric oxide concentrations (> 80 parts per billion) during 40% of the time. Change to gas tank-supplied nitric oxide-free compressed air decreased the arterial oxygen tension by 10% and increased pulmonary vascular resistance by 13%. The addition of 5 ppm nitric oxide had a minimal effect on arterial oxygen tension and pulmonary vascular resistance when added to hospital-supplied compressed air but improved both when added to tank-supplied compressed air. Unintended inhalation of nitric oxide increases arterial oxygen tension and decreases pulmonary vascular resistance in patients with acute lung injury and acute respiratory distress syndrome. The unintended nitric oxide inhalation interferes with the therapeutic use of nitric oxide.

Chest tube insertion - series (image)

MedlinePlus

... cause the lung to collapse, such as: air leaks from the lung into the chest (pneumothorax) bleeding ... nursing staff will carefully check for possible air leaks, breathing difficulties, and need for additional oxygen. Frequent ...

The role of Nb in intensity increase of Er ion upconversion luminescence in zirconia

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

Smits, K., E-mail: smits@cfi.lu.lv; Sarakovskis, A.; Grigorjeva, L.

2014-06-07

It is found that Nb co-doping increases the luminescence and upconversion luminescence intensity in rare earth doped zirconia. Er and Yb-doped nanocrystalline samples with or without Nb co-doping were prepared by sol-gel method and thermally annealed to check for the impact of phase transition on luminescence properties. Phase composition and grain sizes were examined by X-ray diffraction; the morphology was checked by scanning- and high-resolution transmission electron microscopes. Both steady-state and time-resolved luminescence were studied. Comparison of samples with different oxygen vacancy concentrations and different Nb concentrations confirmed the known assumption that oxygen vacancies are the main agents for tetragonalmore » or cubic phase stabilization. The oxygen vacancies quench the upconversion luminescence; however, they also prevent agglomeration of rare-earth ions and/or displacement of rare-earth ions to grain surfaces. It is found that co-doping with Nb ions significantly (>20 times) increases upconversion luminescence intensity. Hence, ZrO{sub 2}:Er:Yb:Nb nanocrystals may show promise for upconversion applications.« less

Complexing Methylene Blue with Phosphorus Dendrimers to Increase Photodynamic Activity.

PubMed

Dabrzalska, Monika; Janaszewska, Anna; Zablocka, Maria; Mignani, Serge; Majoral, Jean Pierre; Klajnert-Maculewicz, Barbara

2017-02-23

The efficiency of photodynamic therapy is limited mainly due to low selectivity, unfavorable biodistribution of photosensitizers, and long-lasting skin sensitivity to light. However, drug delivery systems based on nanoparticles may overcome the limitations mentioned above. Among others, dendrimers are particularly attractive as carriers, because of their globular architecture and high loading capacity. The goal of the study was to check whether an anionic phosphorus dendrimer is suitable as a carrier of a photosensitizer-methylene blue (MB). As a biological model, basal cell carcinoma cell lines were used. We checked the influence of the MB complexation on its singlet oxygen production ability using a commercial fluorescence probe. Next, cellular uptake, phototoxicity, reactive oxygen species (ROS) generation, and cell death were investigated. The MB-anionic dendrimer complex (MB-1an) was found to generate less singlet oxygen; however, the complex showed higher cellular uptake and phototoxicity against basal cell carcinoma cell lines, which was accompanied with enhanced ROS production. Owing to the obtained results, we conclude that the photodynamic activity of MB complexed with an anionic dendrimer is higher than free MB against basal cell carcinoma cell lines.

STS-113 workers work on oxygen leak in Endeavor's mid-body

NASA Technical Reports Server (NTRS)

2002-01-01

KENNEDY SPACE CENTER, FLA. -- Workers on Launch Pad 39A perform checks on Endeavour?s oxygen flex hose fitting through manual inspection and using helium detectors. Visual inspection found a deformity in the flex line braid where it connects to rigid tubing. The entire flex hose assembly and bulkhead fitting were removed early today, and work is under way to complete the installation of a replacement.

iss048e061332

NASA Image and Video Library

2016-08-19

ss048e061332 (08/19/2016) --- Checking the space gloves before and after a spacewalk is part of the detailed check list astronauts go through to provide absolute safety. Both NASA astronaut Jeff Williams and Kate Rubens took part in the important inspections before and after their 19 Aug 2016 spacewalk to install a new docking adapter . A cut in the glove could subject the astronaut to the extreme temperatures of outer space and the escape of oxygen, both of which could be fatal.

Indirect potentiometric titration of ascorbic acid in pharmaceutical preparations using copper based mercury film electrode.

PubMed

Abdul Kamal Nazer, Meeran Mohideen; Hameed, Abdul Rahman Shahul; Riyazuddin, Patel

2004-01-01

A simple and rapid potentiometric method for the estimation of ascorbic acid in pharmaceutical dosage forms has been developed. The method is based on treating ascorbic acid with iodine and titration of the iodide produced equivalent to ascorbic acid with silver nitrate using Copper Based Mercury Film Electrode (CBMFE) as an indicator electrode. Interference study was carried to check possible interference of usual excipients and other vitamins. The precision and accuracy of the method was assessed by the application of lack-of-fit test and other statistical methods. The results of the proposed method and British Pharmacopoeia method were compared using F and t-statistical tests of significance.

Developmental testing resulting in a simplified liquid oxygen check valve for the Space Shuttle Main Propulsion System

NASA Technical Reports Server (NTRS)

Aber, Gregory S.; Barrett, Michael J.; Reith, Timothy W.

1993-01-01

The coil spring in a Space Shuttle liquid oxygen check valve failed due to cyclic fatigue in September, 1991. The dual-flapper, swing check valve is used to prevent reverse flow to the Space Shuttle Main Engines. Upon inspection of the failed component, the spring tangs were found to be missing and heavy wear was observed on the inner diameter of the spring coils. The fracture surfaces revealed that the metal had been steadily worn away until a simple overload caused the final fracture. A series of flow tests using water and a water/gas mixture was conducted to identify the flow phenomenon which produced the cyclic wear. A Plexiglas outlet housing was utilized to view the flapper behavior under different flow conditions and to aid in high speed photography. The tests revealed that flow instabilities induced two oscillatory flapper responses: a rocking mode and a chattering mode. Initially, attempts were made to reduce the spring-flapper oscillations. However, the final solution to the problem was a springless configuration which satisfied the valve's design requirements and eliminated the oscillations. The springless design relied on the inherent ability of the reverse flow momentum to close the flappers.

An audit of level two and level three checks of anaesthesia delivery systems performed at three hospitals in South Australia.

PubMed

Sweeney, N; Owen, H; Fronsko, R; Hurlow, E

2012-11-01

Anaesthetists may subject patients to unnecessary risk by not checking anaesthetic equipment thoroughly before use. Numerous adverse events have been associated with failure to check equipment. The Australian and New Zealand College of Anaesthetists and anaesthetic delivery system manufactures have made recommendations on how anaesthetic equipment should be maintained and checked before use and for the training required for staff who use such equipment. These recommendations are made to minimise the risk to patients undergoing anaesthesia. This prospective audit investigated the adherence of anaesthetic practitioners to a selection of those recommendations. Covert observations of anaesthetic practitioners were made while they were checking their designated anaesthetic machine, either at the beginning of a day's list or between cases. Structured interviews with staff who check the anaesthetic machine were carried out to determine the training they had received. The results indicated poor compliance with recommendations: significantly, the backup oxygen cylinders' pressure/contents were not checked in 45% of observations; the emergency ventilation device was not checked in 67% of observations; the breathing circuit was not tested between patients in 79% of observations; no documentation of the checks performed was done in any cases; and no assessment or accreditation of the staff who performed these checks was performed. It was concluded that the poor compliance was a system failing and that patient safety might be increased with training and accrediting staff responsible for checking equipment, documenting the checks performed, and the formulation and use of a checklist.

Satellite-Based EMI Detection, Identification, and Mitigation

NASA Astrophysics Data System (ADS)

Stottler, R.; Bowman, C.

2016-09-01

Commanding, controlling, and maintaining the health of satellites requires a clear operating spectrum for communications. Electro Magnetic Interference (EMI) from other satellites can interfere with these communications. Determining which satellite is at fault improves space situational awareness and can be used to avoid the problem in the future. The Rfi detection And Prediction Tool, Optimizing Resources (RAPTOR) monitors the satellite communication antenna signals to detect EMI (also called RFI for Radio Frequency Interference) using a neural network trained on past cases of both normal communications and EMI events. RAPTOR maintains a database of satellites that have violated the reserved spectrum in the past. When satellite-based EMI is detected, RAPTOR first checks this list to determine if any are angularly close to the satellite being communicated with. Additionally, RAPTOR checks the Space Catalog to see if any of its active satellites are angularly close. RAPTOR also consults on-line databases to determine if the described operating frequencies of the satellites match the detected EMI and recommends candidates to be added to the known offenders database, accordingly. Based on detected EMI and predicted orbits and frequencies, RAPTOR automatically reschedules satellite communications to avoid current and future satellite-based EMI. It also includes an intuitive display for a global network of satellite communications antennas and their statuses including the status of their EM spectrum. RAPTOR has been prototyped and tested with real data (amplitudes versus frequency over time) for both satellite communication signals and is currently undergoing full-scale development. This paper describes the RAPTOR technologies and results of testing.

Quasiparticle Interference on Cubic Perovskite Oxide Surfaces.

PubMed

Okada, Yoshinori; Shiau, Shiue-Yuan; Chang, Tay-Rong; Chang, Guoqing; Kobayashi, Masaki; Shimizu, Ryota; Jeng, Horng-Tay; Shiraki, Susumu; Kumigashira, Hiroshi; Bansil, Arun; Lin, Hsin; Hitosugi, Taro

2017-08-25

We report the observation of coherent surface states on cubic perovskite oxide SrVO_{3}(001) thin films through spectroscopic-imaging scanning tunneling microscopy. A direct link between the observed quasiparticle interference patterns and the formation of a d_{xy}-derived surface state is supported by first-principles calculations. We show that the apical oxygens on the topmost VO_{2} plane play a critical role in controlling the coherent surface state via modulating orbital state.

Predator interference effects on biological control: The "paradox" of the generalist predator revisited

NASA Astrophysics Data System (ADS)

Parshad, Rana D.; Bhowmick, Suman; Quansah, Emmanuel; Basheer, Aladeen; Upadhyay, Ranjit Kumar

2016-10-01

An interesting conundrum in biological control questions the efficiency of generalist predators as biological control agents. Theory suggests, generalist predators are poor agents for biological control, primarily due to mutual interference. However field evidence shows they are actually quite effective in regulating pest densities. In this work we provide a plausible answer to this paradox. We analyze a three species model, where a generalist top predator is introduced into an ecosystem as a biological control, to check the population of a middle predator, that in turn is depredating on a prey species. We show that the inclusion of predator interference alone, can cause the solution of the top predator equation to blow-up in finite time, while there is global existence in the no interference case. This result shows that interference could actually cause a population explosion of the top predator, enabling it to control the target species, thus corroborating recent field evidence. Our results might also partially explain the population explosion of certain species, introduced originally for biological control purposes, such as the cane toad (Bufo marinus) in Australia, which now functions as a generalist top predator. We also show both Turing instability and spatio-temporal chaos in the model. Lastly we investigate time delay effects.

Effect of Chinese medicines Chan Su, Asian ginseng, Siberian ginseng, and American ginseng on a new digoxin immunoassay based on luminescent oxygen channeling technology.

PubMed

Dasgupta, Amitava; Syklawer, Erica; Johnson, Myrtle; Hwang, Shen-An; Boyd, Sydney A; Actor, Jeffrey K

2011-10-01

Chan Su, Asian ginseng, Siberian ginseng, and American ginseng are known to interfere with various digoxin immunoassays. Recently, a homogeneous sequential chemiluminescent assay for digoxin based on the luminescent oxygen channeling technology (LOCI digoxin) for application on the Dimension and Vista platform has been introduced into the market. The effects of interference by Chan Su and various ginsengs on this new immunoassay have not yet been reported. Aliquots of a drug-free serum pool were supplemented with Chan Su, Asian ginseng, Siberian ginseng, and American ginseng representing the expected in vivo concentrations after normal usage and cases of overdose. Serum digoxin concentrations were measured using the LOCI digoxin assay on the Vista 1500 analyzer. We also prepared 3 digoxin pools from patients receiving digoxin. Two digoxin pools were supplemented with these traditional medicines to investigate their effect on serum digoxin measurements. Mice were fed Chan Su extract to determine the potential of in vivo derived interfering factors. The possibility of eliminating interference of Chan Su on serum digoxin measurement was also investigated, by measuring free digoxin concentration after supplementing aliquots of the third digoxin pool with various amounts of Chan Su extract. A clinically significant interference by Chan Su with serum digoxin measurement was observed using the LOCI digoxin assay. The various ginsengs demonstrated negligible effects. In addition, apparent digoxin concentrations were observed in sera of mice after feeding them with Chan Su; the half-life of digoxin-like immunoreactive components was approximately 1 hour. Moreover, serum digoxin concentrations were significantly elevated in the presence of Chan Su, whereas the various ginsengs exhibited no effect. Monitoring free digoxin can only partly eliminate the interference of Chan Su in serum digoxin measurement. Chan Su interferes with serum digoxin measurement using the LOCI Digoxin, whereas the ginsengs demonstrated no measurable interference at clinically relevant concentrations.

Algorithm design for automated transportation photo enforcement camera image and video quality diagnostic check modules

NASA Astrophysics Data System (ADS)

Raghavan, Ajay; Saha, Bhaskar

2013-03-01

Photo enforcement devices for traffic rules such as red lights, toll, stops, and speed limits are increasingly being deployed in cities and counties around the world to ensure smooth traffic flow and public safety. These are typically unattended fielded systems, and so it is important to periodically check them for potential image/video quality problems that might interfere with their intended functionality. There is interest in automating such checks to reduce the operational overhead and human error involved in manually checking large camera device fleets. Examples of problems affecting such camera devices include exposure issues, focus drifts, obstructions, misalignment, download errors, and motion blur. Furthermore, in some cases, in addition to the sub-algorithms for individual problems, one also has to carefully design the overall algorithm and logic to check for and accurately classifying these individual problems. Some of these issues can occur in tandem or have the potential to be confused for each other by automated algorithms. Examples include camera misalignment that can cause some scene elements to go out of focus for wide-area scenes or download errors that can be misinterpreted as an obstruction. Therefore, the sequence in which the sub-algorithms are utilized is also important. This paper presents an overview of these problems along with no-reference and reduced reference image and video quality solutions to detect and classify such faults.

[Role of erythrocyte cytoplasmic structures in changes in the affinity of haemoglobin for oxygen].

PubMed

Bryzgalova, N Iu; Brazhe, N A; Iusipovich, A U; Maksimov, G V; Rubin, A B

2009-01-01

Changes in the refractive index of the cytoplasm and the affinity of haemoporphyrin of erythrocyte haemoglobin to oxygen (pH, 2,3-diphosphoglycerate) have been investigated using laser interference microscopy and Raman spectroscopy. It has been established that a decrease in pH and an increase in the content of 2,3-diphosphoglycerate are accompanied by changes in both the form of the cell and the refractive index of the cytoplasm and the affinity of haemoporphyrin of hemoglobin to oxygen. It has been shown that as pH is reduced, the capacity of haemoporphyrin for binding oxygen decreases and as the concentration of 2,3-diphosphoglycerate is increased, the ability of haemoporphyrin for oxygen reabsorption increases.

A dual-plate ITO-ITO generator-collector microtrench sensor: surface activation, spatial separation and suppression of irreversible oxygen and ascorbate interference.

PubMed

Hasnat, Mohammad A; Gross, Andrew J; Dale, Sara E C; Barnes, Edward O; Compton, Richard G; Marken, Frank

2014-02-07

Generator-collector electrode systems are based on two independent working electrodes with overlapping diffusion fields where chemically reversible redox processes (oxidation and reduction) are coupled to give amplified current signals. A generator-collector trench electrode system prepared from two tin-doped indium oxide (ITO) electrodes placed vis-à-vis with a 22 μm inter-electrode gap is employed here as a sensor in aqueous media. The reversible 2-electron anthraquinone-2-sulfonate redox system is demonstrated to give well-defined collector responses even in the presence of oxygen due to the irreversible nature of the oxygen reduction. For the oxidation of dopamine on ITO, novel "Piranha-activation" effects are observed and chemically reversible generator-collector feedback conditions are achieved at pH 7, by selecting a more negative collector potential, again eliminating possible oxygen interference. Finally, dopamine oxidation in the presence of ascorbate is demonstrated with the irreversible oxidation of ascorbate at the "mouth" of the trench electrode and chemically reversible oxidation of dopamine in the trench "interior". This spatial separation of chemically reversible and irreversible processes within and outside the trench is discussed as a potential in situ microscale sensing and separation tool.

Impaired cerebral development in fetuses with congenital cardiovascular malformations: Is it the result of inadequate glucose supply?

PubMed

Rudolph, Abraham M

2016-08-01

Cerebral development may be impaired in fetuses with congenital cardiovascular malformations, particularly hypoplastic left heart syndrome (HLHS) and aortopulmonary transposition (APT). The decreased cerebral arterial pusatility index observed in some of these fetuses led to the belief that cerebral vascular resistance was reduced as a result of arterial hypoxemia and cerebral hypoxia is thought to be responsible for impaired cerebral growth. However, other hemodynamic factors could affect pulsatility index. I propose that cerebral blood flow is reduced in fetuses with HLHS and that reduced glucose, rather than oxygen, delivery interferes with cerebral development. This is based on the fact that most of these fetuses do not have lactate accumulation in the brain.In fetuses with APT, umbilical venous blood, containing oxygen and glucose derived across the placenta, is distributed to the lungs and lower body; venous blood, with low oxygen and glucose content, is delivered to the ascending aorta and brain. Oxygen and glucose delivery may further be reduced by decreased cerebral blood flow resulting from run-off of aortic blood through the ductus arteriosus to the pulmonary circulation during diastole. In APT fetuses, lack of lactate in the brain also supports my proposal that glucose deficiency interferes with cerebral development.

Strategies for laser-induced fluorescence detection of nitric oxide in high-pressure flames. II. A-X(0,1) excitation

NASA Astrophysics Data System (ADS)

Bessler, Wolfgang G.; Schulz, Christof; Lee, Tonghun; Jeffries, Jay B.; Hanson, Ronald K.

2003-04-01

A-X(0,1) excitation is a promising new approach for NO laser-induced fluorescence (LIF) diagnostics at elevated pressures and temperatures. We present what to our knowledge are the first detailed spectroscopic investigations within this excitation band using wavelength-resolved LIF measurements in premixed methane/air flames at pressures between 1 and 60 bar and a range of fuel/air ratios. Interference from O2 LIF is a significant problem in lean flames for NO LIF measurements, and pressure broadening and quenching lead to increased interference with increased pressure. Three different excitation schemes are identified that maximize NO/O2 LIF signal ratios, thereby minimizing the O2 interference. The NO LIF signal strength, interference by hot molecular oxygen, and temperature dependence of the three schemes are investigated.

Optical Oxygen Micro- and Nanosensors for Plant Applications

PubMed Central

Ast, Cindy; Schmälzlin, Elmar; Löhmannsröben, Hans-Gerd; van Dongen, Joost T.

2012-01-01

Pioneered by Clark's microelectrode more than half a century ago, there has been substantial interest in developing new, miniaturized optical methods to detect molecular oxygen inside cells. While extensively used for animal tissue measurements, applications of intracellular optical oxygen biosensors are still scarce in plant science. A critical aspect is the strong autofluorescence of the green plant tissue that interferes with optical signals of commonly used oxygen probes. A recently developed dual-frequency phase modulation technique can overcome this limitation, offering new perspectives for plant research. This review gives an overview on the latest optical sensing techniques and methods based on phosphorescence quenching in diverse tissues and discusses the potential pitfalls for applications in plants. The most promising oxygen sensitive probes are reviewed plus different oxygen sensing structures ranging from micro-optodes to soluble nanoparticles. Moreover, the applicability of using heterologously expressed oxygen binding proteins and fluorescent proteins to determine changes in the cellular oxygen concentration are discussed as potential non-invasive cellular oxygen reporters. PMID:22969334

Guide for Oxygen Component Qualification Tests

NASA Technical Reports Server (NTRS)

Bamford, Larry J.; Rucker, Michelle A.; Dobbin, Douglas

1996-01-01

Although oxygen is a chemically stable element, it is not shock sensitive, will not decompose, and is not flammable. Oxygen use therefore carries a risk that should never be overlooked, because oxygen is a strong oxidizer that vigorously supports combustion. Safety is of primary concern in oxygen service. To promote safety in oxygen systems, the flammability of materials used in them should be analyzed. At the NASA White Sands Test Facility (WSTF), we have performed configurational tests of components specifically engineered for oxygen service. These tests follow a detailed WSTF oxygen hazards analysis. The stated objective of the tests was to provide performance test data for customer use as part of a qualification plan for a particular component in a particular configuration, and under worst-case conditions. In this document - the 'Guide for Oxygen Component Qualification Tests' - we outline recommended test systems, and cleaning, handling, and test procedures that address worst-case conditions. It should be noted that test results apply specifically to: manual valves, remotely operated valves, check valves, relief valves, filters, regulators, flexible hoses, and intensifiers. Component systems are not covered.

Rostro-caudal and dorso-ventral gradients in medial and lateral prefrontal cortex during cognitive control of affective and cognitive interference.

PubMed

Rahm, Christoffer; Liberg, Benny; Wiberg-Kristoffersen, Maria; Aspelin, Peter; Msghina, Mussie

2013-04-01

Characterizing the anatomical substrates of major brain functions such as cognition and emotion is of utmost importance to the ongoing efforts of understanding the nature of psychiatric ailments and their potential treatment. The aim of our study was to investigate how the brain handles affective and cognitive interferences on cognitive processes. Functional magnetic resonance imaging investigation was performed on healthy individuals, comparing the brain oxygenation level dependent activation patterns during affective and cognitive counting Stroop tasks. The affective Stroop task activated rostral parts of medial prefrontal cortex (PFC) and rostral and ventral parts of lateral PFC, while cognitive Stroop activated caudal parts of medial PFC and caudal and dorsal parts of lateral PFC. Our findings suggest that the brain may handle affective and cognitive interference on cognitive processes differentially, with affective interference preferentially activating rostral and ventral PFC networks and cognitive interference activating caudal and dorsal PFC networks. © 2013 The Authors. Scandinavian Journal of Psychology © 2013 The Scandinavian Psychological Associations.

Checking for Circular Dependencies in Distributed Stream Programs

DTIC Science & Technology

2011-08-29

extensions to express new complexities more conve- nient. Teleport messaging ( TMG ) in the StreamIt language [30] is an example. 1.1 StreamIt Language...dynamicities to an FIR computation Thies et al. in [30] give a TMG model for distributed stream pro- grams. TMG is a mechanism that implements control...messages for stream graphs. The TMG mechanism is designed not to interfere with original dataflow graphs’ structures and scheduling, therefore a key

SFOG (Solid Fuel Oxygen Generator) candles in the RS (Russian Segment)

NASA Image and Video Library

2009-08-16

ISS020-E-031138 (16 Aug. 2009) --- Cosmonaut Gennady Padalka, Expedition 20 commander, performs a check on the Russian POTOK-150MK (150 micron) air filter unit of the Zvezda Service Module’s SOGS air revitalization subsystem on the International Space Station.

SFOG (Solid Fuel Oxygen Generator) candles in the RS (Russian Segment)

NASA Image and Video Library

2009-08-16

ISS020-E-031128 (16 Aug. 2009) --- Cosmonaut Gennady Padalka, Expedition 20 commander, performs a check on the Russian POTOK-150MK (150 micron) air filter unit of the Zvezda Service Module’s SOGS air revitalization subsystem on the International Space Station.

A self-consistency check for unitary propagation of Hawking quanta

NASA Astrophysics Data System (ADS)

Baker, Daniel; Kodwani, Darsh; Pen, Ue-Li; Yang, I.-Sheng

2017-11-01

The black hole information paradox presumes that quantum field theory in curved space-time can provide unitary propagation from a near-horizon mode to an asymptotic Hawking quantum. Instead of invoking conjectural quantum-gravity effects to modify such an assumption, we propose a self-consistency check. We establish an analogy to Feynman’s analysis of a double-slit experiment. Feynman showed that unitary propagation of the interfering particles, namely ignoring the entanglement with the double-slit, becomes an arbitrarily reliable assumption when the screen upon which the interference pattern is projected is infinitely far away. We argue for an analogous self-consistency check for quantum field theory in curved space-time. We apply it to the propagation of Hawking quanta and test whether ignoring the entanglement with the geometry also becomes arbitrarily reliable in the limit of a large black hole. We present curious results to suggest a negative answer, and we discuss how this loss of naive unitarity in QFT might be related to a solution of the paradox based on the soft-hair-memory effect.

A simplified concept for controlling oxygen mixtures in the anaesthetic machine--better, cheaper and more user-friendly?

PubMed

Berge, J A; Gramstad, L; Grimnes, S

1995-05-01

Modern anaesthetic machines are equipped with several safety components to prevent delivery of hypoxic mixtures. However, such a technical development has increased the complexity of the equipment. We report a reconstructed anaesthetic machine in which a paramagnetic oxygen analyzer has provided the means to simplify the apparatus. The new machine is devoid of several components conventionally included to prevent hypoxic mixtures: oxygen failure protection device, reservoir O2 alarm, N2O/air selector, and proportioning system for oxygen/nitrous oxide delivery. These devices have been replaced by a simple safety system using a paramagnetic oxygen analyzer at the common gas outlet, which in a feed-back system cuts off the supply of nitrous oxide whenever the oxygen concentration falls below 25%. The simplified construction of the anaesthetic machine has important consequences for safety, cost and user-friendliness. Reducing the complexity of the construction also simplifies the pre-use checkout procedure, and an efficient 5-point check list is presented for the new machine.

Received response based heuristic LDPC code for short-range non-line-of-sight ultraviolet communication.

PubMed

Qin, Heng; Zuo, Yong; Zhang, Dong; Li, Yinghui; Wu, Jian

2017-03-06

Through slight modification on typical photon multiplier tube (PMT) receiver output statistics, a generalized received response model considering both scattered propagation and random detection is presented to investigate the impact of inter-symbol interference (ISI) on link data rate of short-range non-line-of-sight (NLOS) ultraviolet communication. Good agreement with the experimental results by numerical simulation is shown. Based on the received response characteristics, a heuristic check matrix construction algorithm of low-density-parity-check (LDPC) code is further proposed to approach the data rate bound derived in a delayed sampling (DS) binary pulse position modulation (PPM) system. Compared to conventional LDPC coding methods, better bit error ratio (BER) below 1E-05 is achieved for short-range NLOS UVC systems operating at data rate of 2Mbps.

Laser application to measure vertical sea temperature and turbidity, design phase

NASA Technical Reports Server (NTRS)

Hirschberg, J. G.; Wouters, A. W.; Simon, K. M.; Byrne, J. D.; Deverdun, C. E.

1976-01-01

An experiment to test a new method was designed, using backscattered radiation from a laser beam to measure oceanographic parameters in a fraction of a second. Tyndall, Rayleigh, Brillouin, and Raman scattering all are utilized to evaluate the parameters. A beam from a continuous argon ion laser is used together with an interferometer and interference filters to gather the information. The results are checked by direct measurements. Future shipboard and airborne experiments are described.

GFAAS determination of selenium in infant formulas using a microwave digestion method.

PubMed

Alegria, A; Barbera, R; Farré, R; Moreno, A

1994-01-01

A method for determining the selenium content of infant formulas is proposed. It includes wet digestion with nitric acid and hydrogen peroxide in medium pressure teflon bombs in a microwave oven and determination by graphite furnace atomic absorption spectrometry (GFAAS). The absence of interferences is checked. Values obtained for the limit of detection (19.4 ng/g), precision (RSD = 2.2%) and accuracy by analysis of a reference material show that the method is reliable.

Neuroimaging of response interference in twins concordant or discordant for inattention and hyperactivity symptoms

PubMed Central

van ’t Ent, D.; van Beijsterveldt, C.E.M.; Derks, E.M.; Hudziak, J.J.; Veltman, D.J.; Todd, R.D.; Boomsma, D.I.; De Geus, E.J.C.

2009-01-01

Attention deficit hyperactivity disorder (ADHD) is to a large extent influenced by genetic factors, but environmental influences are considered important as well. To distinguish between functional brain changes underlying primarily genetically and environmentally mediated ADHD, we used functional MRI to compare response interference in monozygotic twins highly concordant or discordant for attention problems (AP). AP scores were assessed longitudinally with the Child Behavior Check List attention problem scale (CBCL-AP). Response interference was measured during two executive function paradigms; a color-word Stroop and a flanker task. The neuroimaging results indicated that, across the entire sample, children with high CBCL-AP scores, relative to children with low CBCL-AP scores, showed decreased activation to response interference in dorsolateral prefrontal, parietal and temporal brain regions. Increased activation was noted in the premotor cortex and regions associated with visual selective attention processing, possibly reflecting compensatory mechanisms to maintain task performance. Specific comparisons of high and low scoring concordant twin pairs suggest that AP of genetic origin was characterized by decreased activation of the left dorsolateral prefrontal cortex during the Stroop task and right parietal lobe during the flanker task. In contrast, comparison of twins from discordant monozygotic pairs, suggest that AP of environmental origin was characterized by decreased activation in left and right temporal lobe areas, but only during Stroop interference. The finding of distinct brain activation changes to response interference in inattention/hyperactivity of ‘genetic’ versus ‘environmental’ origin, indicate that genetic and environmental risk factors for attention/hyperactivity problems affect the brain in different ways. PMID:19409224

30 CFR 75.362 - On-shift examination.

Code of Federal Regulations, 2011 CFR

2011-07-01

... shift. The certified person shall check for hazardous conditions, test for methane and oxygen deficiency... interruption in production on a section, the examination shall be made anytime within 1 hour of the shift change. In those instances when there is an interruption in production during the shift change, the...

30 CFR 75.362 - On-shift examination.

Code of Federal Regulations, 2010 CFR

2010-07-01

... shift. The certified person shall check for hazardous conditions, test for methane and oxygen deficiency... interruption in production on a section, the examination shall be made anytime within 1 hour of the shift change. In those instances when there is an interruption in production during the shift change, the...

Performance of the rebuilt SUERC single-stage accelerator mass spectrometer

NASA Astrophysics Data System (ADS)

Shanks, Richard P.; Ascough, Philippa L.; Dougans, Andrew; Gallacher, Paul; Gulliver, Pauline; Rood, Dylan H.; Xu, Sheng; Freeman, Stewart P. H. T.

2015-10-01

The SUERC bipolar single-stage accelerator mass spectrometer (SSAMS) has been dismantled and rebuilt to accommodate an additional rotatable pre-accelerator electrostatic spherical analyser (ESA) and a second ion source injector. This is for the attachment of an experimental positive-ion electron cyclotron resonance (ECR) ion source in addition to a Cs-sputter source. The ESA significantly suppresses oxygen interference to radiocarbon detection, and remaining measurement interference is now thought to be from 13C injected as 13CH molecule scattering off the plates of a second original pre-detector ESA.

Gas-phase mercury reduction to measure total mercury in the flue gas of a coal-fired boiler.

PubMed

Meischen, Sandra J; Van Pelt, Vincent J; Zarate, Eugene A; Stephens, Edward A

2004-01-01

Gaseous elemental and total (elemental + oxidized) mercury (Hg) in the flue gas from a coal-fired boiler was measured by a modified ultraviolet (UV) spectrometer. Challenges to Hg measurement were the spectral interferences from other flue gas components and that UV measures only elemental Hg. To eliminate interference from flue gas components, a cartridge filled with gold-coated sand removed elemental Hg from a flue gas sample. The Hg-free flue gas was the reference gas, eliminating the spectral interferences. To measure total Hg by UV, oxidized Hg underwent a gas-phase, thermal-reduction in a quartz cell heated to 750 degrees C. Simultaneously, hydrogen was added to flash react with the oxygen present forming water vapor and preventing Hg re-oxidation as it exits the cell. Hg concentration results are in parts per billion by volume Hg at the flue gas oxygen concentration. The modified Hg analyzer and the Ontario Hydro method concurrently measured Hg at a field test site. Measurements were made at a 700-MW steam turbine plant with scrubber units and selective catalytic reduction. The flue gas sampled downstream of the selective catalytic reduction contained 2100 ppm SO2 and 75 ppm NOx. Total Hg measured by the Hg analyzer was within 20% of the Ontario Hydro results.

The oxygen paradox of neurovascular coupling

PubMed Central

Leithner, Christoph; Royl, Georg

2014-01-01

The coupling of cerebral blood flow (CBF) to neuronal activity is well preserved during evolution. Upon changes in the neuronal activity, an incompletely understood coupling mechanism regulates diameter changes of supplying blood vessels, which adjust CBF within seconds. The physiologic brain tissue oxygen content would sustain unimpeded brain function for only 1 second if continuous oxygen supply would suddenly stop. This suggests that the CBF response has evolved to balance oxygen supply and demand. Surprisingly, CBF increases surpass the accompanying increases of cerebral metabolic rate of oxygen (CMRO2). However, a disproportionate CBF increase may be required to increase the concentration gradient from capillary to tissue that drives oxygen delivery. However, the brain tissue oxygen content is not zero, and tissue pO2 decreases could serve to increase oxygen delivery without a CBF increase. Experimental evidence suggests that CMRO2 can increase with constant CBF within limits and decreases of baseline CBF were observed with constant CMRO2. This conflicting evidence may be viewed as an oxygen paradox of neurovascular coupling. As a possible solution for this paradox, we hypothesize that the CBF response has evolved to safeguard brain function in situations of moderate pathophysiological interference with oxygen supply. PMID:24149931

A Quantitative Evaluation of Dissolved Oxygen Instrumentation

NASA Technical Reports Server (NTRS)

Pijanowski, Barbara S.

1971-01-01

The implications of the presence of dissolved oxygen in water are discussed in terms of its deleterious or beneficial effects, depending on the functional consequences to those affected, e.g., the industrialist, the oceanographer, and the ecologist. The paper is devoted primarily to an examination of the performance of five commercially available dissolved oxygen meters. The design of each is briefly reviewed and ease or difficulty of use in the field described. Specifically, the evaluation program treated a number of parameters and user considerations including an initial check and trial calibration for each instrument and a discussion of the measurement methodology employed. Detailed test results are given relating to the effects of primary power variation, water-flow sensitivity, response time, relative accuracy of dissolved-oxygen readout, temperature accuracy (for those instruments which included this feature), error and repeatability, stability, pressure and other environmental effects, and test results obtained in the field. Overall instrument performance is summarized comparatively by chart.

Strategies for laser-induced fluorescence detection of nitric oxide in high-pressure flames. I. A-X (0,0) excitation

NASA Astrophysics Data System (ADS)

Bessler, Wolfgang G.; Schulz, Christof; Lee, Tonghun; Jeffries, Jay B.; Hanson, Ronald K.

2002-06-01

Three different high-pressure flame measurement strategies for NO laser-induced fluorescence (LIF) with A-X (0,0) excitation have been studied previously with computational simulations and experiments in flames up to 15 bars. Interference from O2 LIF is a significant problem in lean flames for NO LIF measurements, and pressure broadening and quenching lead to increased interference with increased pressure. We investigate the NO LIF signal strength, interference by hot molecular oxygen, and temperature dependence of the three previous schemes and for two newly chosen excitation schemes with wavelength-resolved LIF measurements in premixed methane and air flames at pressures between 1 and 60 bars and a range of fuel /air ratios. In slightly lean flames with an equivalence ratio of 0.83 at 60 bars, the contribution of O2 LIF to the NO LIF signal varies between 8% and 29% for the previous schemes. The O2 interference is best suppressed with excitation at 226.03 nm.

Online monitoring of dissolved oxygen tension in microtiter plates based on infrared fluorescent oxygen-sensitive nanoparticles.

PubMed

Ladner, Tobias; Flitsch, David; Schlepütz, Tino; Büchs, Jochen

2015-10-09

During the past years, new high-throughput screening systems with capabilities of online monitoring turned out to be powerful tools for the characterization of microbial cell cultures. These systems are often easy to use, offer economic advantages compared to larger systems and allow to determine many important process parameters within short time. Fluorescent protein tags tremendously simplified the tracking and observation of cellular activity in vivo. Unfortunately, interferences between established fluorescence based dissolved oxygen tension (DOT) measurement techniques and fluorescence-based protein tags appeared. Therefore, the applicability of new oxygen-sensitive nanoparticles operated within the more suitable infrared wavelength region are introduced and validated for DOT measurement. The biocompatibility of the used dispersed oxygen-sensitive nanoparticles was proven via RAMOS cultivations for Hansenula polymorpha, Gluconobacter oxydans, and Escherichia coli. The applicability of the introduced DOT measurement technique for online monitoring of cultivations was demonstrated and successfully validated. The nanoparticles showed no disturbing effect on the online measurement of the fluorescence intensities of the proteins GFP, mCherry and YFP measured by a BioLector prototype. Additionally, the DOT measurement was not influenced by changing concentrations of these proteins. The kLa values for the applied cultivation conditions were successfully determined based on the measured DOT. The introduced technique appeared to be practically as well as economically advantageous for DOT online measuring in microtiter plates. The disadvantage of limited availability of microtiter plates with immobilized sensor spots (optodes) does not apply for this introduced technique. Due to the infrared wavelength range, used for the DOT measurement, no interferences with biogenic fluorescence or with expressed fluorescent proteins (e.g. YFP, GFP or mCherry) occur.

EVALUATION OF METHYL TERT-BUTYL ETHER (MTBE) AS AN INTERFERENCE ON COMMERCIAL BREATH-ALCOHOL ANALYZERS

EPA Science Inventory

Anecdotal reports suggest that high environmental or occupational exposures to the fuel oxygenate methyl tert-butyl ether (MTBE) may result in breath concentrations that are sufficiently elevated to cause a false positive on commercial breath-alcohol analyzers. We evaluated th...

LDPC product coding scheme with extrinsic information for bit patterned media recoding

NASA Astrophysics Data System (ADS)

Jeong, Seongkwon; Lee, Jaejin

2017-05-01

Since the density limit of the current perpendicular magnetic storage system will soon be reached, bit patterned media recording (BPMR) is a promising candidate for the next generation storage system to achieve an areal density beyond 1 Tb/in2. Each recording bit is stored in a fabricated magnetic island and the space between the magnetic islands is nonmagnetic in BPMR. To approach recording densities of 1 Tb/in2, the spacing of the magnetic islands must be less than 25 nm. Consequently, severe inter-symbol interference (ISI) and inter-track interference (ITI) occur. ITI and ISI degrade the performance of BPMR. In this paper, we propose a low-density parity check (LDPC) product coding scheme that exploits extrinsic information for BPMR. This scheme shows an improved bit error rate performance compared to that in which one LDPC code is used.

Kudzu (Pueraria montana) community responses to herbicides, burning, and high-density loblolly pine

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

T.B. Harrington; L.T. Rader-Dixon; J.W. Taylor, Jr.

Kudzu is an aggressive, nonnative vine that currently dominates an estimated 810,000 ha of mesic forest communities in the eastern United States. To test an integrated method of weed control, abundances of kudzu and other plant species were compared during 4 yr after six herbicide treatments (clopyralid, triclopyr, metsulfuron, picloram 1 2,4-D, tebuthiuron, and a nonsprayed check), in which loblolly pines were planted at three densities (0, 1, and 4 seedlings m22) to induce competition and potentially delay kudzu recovery. This split-plot design was replicated on each of the four kudzu-dominated sites near Aiken, SC. Relative light intensity (RLI) andmore » soil water content (SWC) were measured periodically to identify mechanisms of interference among plant species. Two years after treatment (1999), crown coverage of kudzu averaged , 2% in herbicide plots compared with 93% in the nonsprayed check, and these differences were maintained through 2001, except in clopyralid plots where kudzu cover increased to 15%. In 2001, pine interference was associated with 33, 56, and 67% reductions in biomass of kudzu, blackberry, and herbaceous vegetation, respectively. RLI in kudzu-dominated plots (4 to 15% of full sun) generally was less than half that of herbicide-treated plots. SWC was greatest in tebuthiuron plots, where total vegetation cover averaged 26% compared with 77 to 111% in other plots. None of the treatments eradicated kudzu, but combinations of herbicides and induced pine competition delayed its recovery.« less

Impact of the timing and duration of weed control on the establishment of a rubber tree plantation.

PubMed

Guzzo, Caio D; Carvalho, Leonardo B de; Giancotti, Paulo R F; Alves, Pedro L C A; Gonçalves, Elaine C P; Martins, José V F

2014-03-01

Rubber tree production is reduced by weeds that compete for environmental resources; therefore, the timing and duration of weed control influences weed interference. The objectives of this study were to evaluate the growth of rubber tree (Hevea brasiliensis) plants, to determine the critical period for weed control, and to evaluate the growth recovery of rubber trees that coexisted with weeds for different periods of time after planting. Two groups of treatments were established under field conditions in the first year of the investigation: one group contained crescent periods of weed infestation, while the other contained crescent periods of weed control, also including a weed-free check and a total weedy check. In the second year of the investigation, the weeds were totally controlled. Urochloa decumbens was the dominant weed (over 90% groundcover). Crop growth was greatly reduced due to the weed interference. Plant height decreased more rapidly than did any other characteristic. Plant height, leaf dry mass, and leaf area decreased by 99%, 97% and 96%, respectively, and were the most reduced characteristics. Plant height also recovered more rapidly than did any characteristic when the period of weed control was lengthened. However, stem dry mass increased by 750%, making it the most recovered characteristic. The critical period for weed control was between 4 and 9½ months after planting in the first year; however, the rubber trees showed an expressive growth recovery when the weeds were controlled throughout the second year.

Isotopic effects in the muon transfer from pmu and dmu to heavier atoms.

PubMed

Dupays, Arnaud

2004-07-23

The results of accurate hyperspherical calculations of the muon-transfer rates from muonic protium and deuterium atoms to nitrogen, oxygen, and neon are reported. Very good agreement with measured rates is obtained and, for the three systems, the isotopic effect is perfectly reproduced. The transfer rate is higher for deuterium in the cases of nitrogen and neon due to constructive interferences between two transfer paths. The lower transfer rate for deuterium in the case of oxygen results from a large resonant contribution. Copyright 2004 The American Physical Society

A cultural side effect: learning to read interferes with identity processing of familiar objects

PubMed Central

Kolinsky, Régine; Fernandes, Tânia

2014-01-01

Based on the neuronal recycling hypothesis (Dehaene and Cohen, 2007), we examined whether reading acquisition has a cost for the recognition of non-linguistic visual materials. More specifically, we checked whether the ability to discriminate between mirror images, which develops through literacy acquisition, interferes with object identity judgments, and whether interference strength varies as a function of the nature of the non-linguistic material. To these aims we presented illiterate, late literate (who learned to read at adult age), and early literate adults with an orientation-independent, identity-based same-different comparison task in which they had to respond “same” to both physically identical and mirrored or plane-rotated images of pictures of familiar objects (Experiment 1) or of geometric shapes (Experiment 2). Interference from irrelevant orientation variations was stronger with plane rotations than with mirror images, and stronger with geometric shapes than with objects. Illiterates were the only participants almost immune to mirror variations, but only for familiar objects. Thus, the process of unlearning mirror-image generalization, necessary to acquire literacy in the Latin alphabet, has a cost for a basic function of the visual ventral object recognition stream, i.e., identification of familiar objects. This demonstrates that neural recycling is not just an adaptation to multi-use but a process of at least partial exaptation. PMID:25400605

Communication: Heterogeneous water dynamics on a clathrate hydrate lattice detected by multidimensional oxygen nuclear magnetic resonance

NASA Astrophysics Data System (ADS)

Adjei-Acheamfour, Mischa; Storek, Michael; Böhmer, Roland

2017-05-01

Previous deuteron nuclear magnetic resonance studies revealed conflicting evidence regarding the possible motional heterogeneity of the water dynamics on the hydrate lattice of an ice-like crystal. Using oxygen-17 nuclei as a sensitive quadrupolar probe, the reorientational two-time correlation function displays a clear nonexponentiality. To check whether this dispersive behavior is a consequence of dynamic heterogeneity or rather of an intrinsic nonexponentiality, a multidimensional, four-time magnetic resonance experiment was devised that is generally applicable to strongly quadrupolarly perturbed half-integer nuclei such as oxygen-17. Measurements of an appropriate four-time function demonstrate that it is possible to select a subensemble of slow water molecules. Its mean time scale is compared to theoretical predictions and evidence for significant motional heterogeneity is found.

Rebamipide does not interfere with the antitumor effect of radiotherapy or chemotherapy in human oral tumor-bearing nude mice.

PubMed

Shibamori, Masafumi; Sato, Masayuki; Uematsu, Naoya; Nakashima, Takako; Sato, Asuka; Yamamura, Yoshiya; Sasabe, Hiroyuki; Umehara, Ken; Sakurai, Kazushi

2015-09-01

Recent studies have shown that rebamipide, which suppresses reactive oxygen species, prevents chemoradiotherapy-induced oral mucositis in patients with head and neck cancers. However, anticancer action of radiotherapy and chemotherapy is believed to be partially associated with generation of reactive oxygen species. The aim of this study was to determine whether rebamipide interferes with the antitumor action of radiotherapy and chemotherapy. The effect of rebamipide on tumor cell growth was investigated using a human oral squamous carcinoma cell line, HSC-2, in vitro and in vivo. Rebamipide showed no significant effect on cell or tumor growth in HSC-2 tumor-bearing nude mice. Influences of rebamipide on the antitumor action of radiotherapy and of chemotherapy with cisplatin or docetaxel were investigated using the same animal model. In radiotherapy, the tumor was treated with 2.5 Gy of X-rays for 5 days, and rebamipide (300 mg/kg p.o.) was administered during irradiation periods. In chemotherapy, tumor-bearing mice were treated once with cisplatin (8 mg/kg, i.v.) or docetaxel (15 mg/kg i.v.) and rebamipide (300 mg/kg p.o.) was administered for 5 days following the antitumor drug treatment. Rebamipide did not interfere with the antitumor action of radiotherapy and chemotherapy. Copyright © 2015 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Hypoxia interferes with ABA metabolism and increases ABA sensitivity in embryos of dormant barley grains.

PubMed

Benech-Arnold, Roberto L; Gualano, Nicolas; Leymarie, Juliette; Côme, Daniel; Corbineau, Françoise

2006-01-01

Two mechanisms have been suggested as being responsible for dormancy in barley grain: (i) ABA in the embryo, and (ii) limitation of oxygen supply to the embryo by oxygen fixation as a result of the oxidation of phenolic compounds in the glumellae. The aim of the present work was to investigate whether hypoxia imposed by the glumellae interferes with ABA metabolism in the embryo, thus resulting in dormancy. In dormant and non-dormant grains incubated at 20 degrees C and in non-dormant grains incubated at 30 degrees C (i.e. when dormancy is not expressed), ABA content in the embryo decreased dramatically during the first 5 h of incubation before germination was detected. By contrast, germination of dormant grains was less than 2% within 48 h at 30 degrees C and embryo ABA content increased during the first hours of incubation and then remained 2-4 times higher than in embryos from grains in which dormancy was not expressed. Removal of the glumellae allowed germination of dormant grains at 30 degrees C and the embryos did not display the initial increase in ABA content. Incubation of de-hulled grains under 5% oxygen to mimic the effect of glumellae, restored the initial increase ABA in content and completely inhibited germination. Incubation of embryos isolated from dormant grains, in the presence of a wide range of ABA concentrations and under various oxygen tensions, revealed that hypoxia increased embryo sensitivity to ABA by 2-fold. This effect was more pronounced at 30 degrees C than at 20 degrees C. Furthermore, when embryos from dormant grains were incubated at 30 degrees C in the presence of 10 microM ABA, their endogenous ABA content remained constant after 48 h of incubation under air, while it increased dramatically in embryos incubated under hypoxia, indicating that the apparent increase in embryo ABA responsiveness induced by hypoxia was, in part, mediated by an inability of the embryo to inactivate ABA. Taken together these results suggest that hypoxia, either imposed artificially or by the glumellae, increases embryo sensitivity to ABA and interferes with ABA metabolism.

Local anaphor licensing in an SOV language: implications for retrieval strategies

PubMed Central

Kush, Dave; Phillips, Colin

2014-01-01

Because morphological and syntactic constraints govern the distribution of potential antecedents for local anaphors, local antecedent retrieval might be expected to make equal use of both syntactic and morphological cues. However, previous research (e.g., Dillon et al., 2013) has shown that local antecedent retrieval is not susceptible to the same morphological interference effects observed during the resolution of morphologically-driven grammatical dependencies, such as subject-verb agreement checking (e.g., Pearlmutter et al., 1999). Although this lack of interference has been taken as evidence that syntactic cues are given priority over morphological cues in local antecedent retrieval, the absence of interference could also be the result of a confound in the materials used: the post-verbal position of local anaphors in prior studies may obscure morphological interference that would otherwise be visible if the critical anaphor were in a different position. We investigated the licensing of local anaphors (reciprocals) in Hindi, an SOV language, in order to determine whether pre-verbal anaphors are subject to morphological interference from feature-matching distractors in a way that post-verbal anaphors are not. Computational simulations using a version of the ACT-R parser (Lewis and Vasishth, 2005) predicted that a feature-matching distractor should facilitate the processing of an unlicensed reciprocal if morphological cues are used in antecedent retrieval. In a self-paced reading study we found no evidence that distractors eased processing of an unlicensed reciprocal. However, the presence of a distractor increased difficulty of processing following the reciprocal. We discuss the significance of these results for theories of cue selection in retrieval. PMID:25414680

40 CFR 89.319 - Hydrocarbon analyzer calibration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... each range calibrated, if the deviation from a least-squares best-fit straight line is 2 percent or... ±0.3 percent of full scale on the zero, the best-fit non-linear equation which represents the data to within these limits shall be used to determine concentration. (d) Oxygen interference optimization...

40 CFR 89.319 - Hydrocarbon analyzer calibration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... each range calibrated, if the deviation from a least-squares best-fit straight line is 2 percent or... ±0.3 percent of full scale on the zero, the best-fit non-linear equation which represents the data to within these limits shall be used to determine concentration. (d) Oxygen interference optimization...

40 CFR 89.319 - Hydrocarbon analyzer calibration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... each range calibrated, if the deviation from a least-squares best-fit straight line is 2 percent or... ±0.3 percent of full scale on the zero, the best-fit non-linear equation which represents the data to within these limits shall be used to determine concentration. (d) Oxygen interference optimization...

[The influence of the organizational structure on the internal controls of a foundation for cancer research, prevention and care in the interior of the state of São Paulo, Brazil].

PubMed

Bonacim, Carlos Alberto Grespam; Salgado, André Luís; Girioli, Lumila Souza; de Araujo, Adriana Maria Procópio

2011-05-01

This work focuses on a discussion about the extent to which the level of organizational structure interferes in the internal control practices of non-governmental organizations (NGOs), especially those related to health. The objective of this work was to observe the efficiency of the internal control tests applied within the organizational structure of the Foundation for Cancer Research, Prevention and Care, checking the reliability of the accounting records and operational controls. A case study in a third sector health organization was the chosen methodology. The case study involved company interviews and the analysis of confidential reports. After an evaluation of the organizational structure (of the relations between officials and volunteers) and the application of evaluation proceedings on the quality of the internal controls, the extent to which the organizational structure interferes with the internal control practices of the hospital was assessed. It was revealed that there are structured mechanisms of control in the institution, however the implementation of these controls is inadequately performed. It was further detected that the level of the organizational structure does indeed interfere in internal control practices at the entity.

Checking Equivalence of SPMD Programs Using Non-Interference

DTIC Science & Technology

2010-01-29

with it hopes to go beyond the limits of Moore’s law, but also worries that programming will become harder [5]. One of the reasons why parallel...array name in G or L, and e is an arithmetic expression of integer type. In the CUDA code shown in Section 3, b and t are represented by coreId and...b+ t. A second, optimized version of the program (using function “reverse2”, see Section 3) can be modeled as a tuple P2 = ( G ,L2, F 2), with G same

Wavefront error sensing for LDR

NASA Technical Reports Server (NTRS)

Tubbs, Eldred F.; Glavich, T. A.

1988-01-01

Wavefront sensing is a significant aspect of the LDR control problem and requires attention at an early stage of the control system definition and design. A combination of a Hartmann test for wavefront slope measurement and an interference test for piston errors of the segments was examined and is presented as a point of departure for further discussion. The assumption is made that the wavefront sensor will be used for initial alignment and periodic alignment checks but that it will not be used during scientific observations. The Hartmann test and the interferometric test are briefly examined.

Quasi-cylindrical theory of wing-body interference at supersonic speeds and comparison with experiment

NASA Technical Reports Server (NTRS)

Nielsen, Jack N

1955-01-01

A theoretical method is presented for calculating the flow field about wing-body combinations employing bodies deviating only slightly in shape from a circular cylinder. The method is applied to the calculation of the pressure field acting between a circular cylindrical body and a rectangular wing. The case of zero body angle of attack and variable wing incidence is considered as well as the case of zero wing incidence and variable body angle of attack. An experiment was performed especially for the purpose of checking the calculative examples.

Low Cost Solar Array Project: Composition Measurements by Analytical Photon Catalysis

NASA Technical Reports Server (NTRS)

Sutton, D. G.; Galvan, L.; Melzer, J.; Heidner, R. F., III

1979-01-01

The applicability of the photon catalysis technique for effecting composition analysis of silicon samples was assessed. Third quarter activities were devoted to the study of impurities in silicon matrices. The evaporation process was shown to be congruent; thus, the spectral analysis of the vapor yields the composition of the bulk sample. Qualitative analysis of metal impurities in silicon was demonstrated e part per million level. Only one atomic spectral interference was noted; however, it is imperative to maintain a leak tight system due to chemical and spectral interferences caused by the presence of even minute amounts of oxygen in the active nitrogen afterglow.

Reduction of skin damage from transcutaneous oxygen electrodes using a spray on dressing.

PubMed Central

Evans, N J; Rutter, N

1986-01-01

A spray on, copolymer acrylic dressing (Op-Site) was used to limit the skin damage caused by a transcutaneous oxygen electrode and its adhesive ring. Two identical electrodes were applied to the abdominal skin of 10 preterm infants, one on untreated skin, the other after application of Op-Site. It was found that Op-Site prevented the epidermal damage (as measured by transepidermal water loss) that occurs when the adhesive ring is removed from untreated skin. It did not interfere with transcutaneous oxygen measurements; absolute values and response times were unchanged. Op-Site is therefore useful in preventing the skin trauma that occurs when transcutaneous oxygen monitoring is being performed in preterm infants below 30 weeks' gestation in the first week of life. Care must be taken, however, to prevent a build up of Op-Site--it should be applied as a single layer, allowed to dry, and removed after use. PMID:3767417

Reduction of skin damage from transcutaneous oxygen electrodes using a spray on dressing.

PubMed

Evans, N J; Rutter, N

1986-09-01

A spray on, copolymer acrylic dressing (Op-Site) was used to limit the skin damage caused by a transcutaneous oxygen electrode and its adhesive ring. Two identical electrodes were applied to the abdominal skin of 10 preterm infants, one on untreated skin, the other after application of Op-Site. It was found that Op-Site prevented the epidermal damage (as measured by transepidermal water loss) that occurs when the adhesive ring is removed from untreated skin. It did not interfere with transcutaneous oxygen measurements; absolute values and response times were unchanged. Op-Site is therefore useful in preventing the skin trauma that occurs when transcutaneous oxygen monitoring is being performed in preterm infants below 30 weeks' gestation in the first week of life. Care must be taken, however, to prevent a build up of Op-Site--it should be applied as a single layer, allowed to dry, and removed after use.

KSC-02pd1716

NASA Image and Video Library

2002-11-14

KENNEDY SPACE CENTER, FLA. -- Workers on Launch Pad 39A perform checks on Endeavour's oxygen flex hose fitting through manual inspection and using helium detectors. Visual inspection found a deformity in the flex line braid where it connects to rigid tubing. The entire flex hose assembly and bulkhead fitting were removed early today, and work is under way to complete the installation of a replacement.

40 CFR 91.316 - Hydrocarbon analyzer calibration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... deviation from a least-squares best-fit straight line is two percent or less of the value at each data point... exceeds two percent at any point, use the best-fit non-linear equation which represents the data to within two percent of each test point to determine concentration. (d) Oxygen interference optimization...

40 CFR 90.316 - Hydrocarbon analyzer calibration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... from a least-squares best-fit straight line is two percent or less of the value at each data point... exceeds two percent at any point, use the best-fit non-linear equation which represents the data to within two percent of each test point to determine concentration. (d) Oxygen interference optimization. Prior...

40 CFR 90.316 - Hydrocarbon analyzer calibration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... from a least-squares best-fit straight line is two percent or less of the value at each data point... exceeds two percent at any point, use the best-fit non-linear equation which represents the data to within two percent of each test point to determine concentration. (d) Oxygen interference optimization. Prior...

40 CFR 90.316 - Hydrocarbon analyzer calibration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... from a least-squares best-fit straight line is two percent or less of the value at each data point... exceeds two percent at any point, use the best-fit non-linear equation which represents the data to within two percent of each test point to determine concentration. (d) Oxygen interference optimization. Prior...

40 CFR 91.316 - Hydrocarbon analyzer calibration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... deviation from a least-squares best-fit straight line is two percent or less of the value at each data point... exceeds two percent at any point, use the best-fit non-linear equation which represents the data to within two percent of each test point to determine concentration. (d) Oxygen interference optimization...

40 CFR 91.316 - Hydrocarbon analyzer calibration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... deviation from a least-squares best-fit straight line is two percent or less of the value at each data point... exceeds two percent at any point, use the best-fit non-linear equation which represents the data to within two percent of each test point to determine concentration. (d) Oxygen interference optimization...

Reduced-Gravity Measurements of the Effect of Oxygen on Properties of Zirconium

NASA Technical Reports Server (NTRS)

Zhao, J.; Lee, J.; Wunderlich, R.; Fecht, H.-J.; Schneider, S.; SanSoucie, M.; Rogers, J.; Hyers, R.

2016-01-01

The influence of oxygen on the thermophysical properties of zirconium is being investigated using MSL-EML (Material Science Laboratory - Electromagnetic Levitator) on ISS (International Space Station) in collaboration with NASA, ESA (European Space Agency), and DLR (German Aerospace Center). Zirconium samples with different oxygen concentrations will be put into multiple melt cycles, during which the density, viscosity, surface tension, heat capacity, and electric conductivity will be measured at various undercooled temperatures. The facility check-up of MSL-EML and the first set of melting experiments have been successfully performed in 2015. The first zirconium sample will be tested near the end of 2015. As part of ground support activities, the thermophysical properties of zirconium and ZrO were measured using a ground-based electrostatic levitator located at the NASA Marshall Space Flight Center. The influence of oxygen on the measured surface tension was evaluated. The results of this research will serve as reference data for those measured in ISS.

Automated point-of-care testing for ABO agglutination test: proof of concept and validation.

PubMed

El Kenz, H; Corazza, F

2015-07-01

ABO-incompatible red blood cell transfusions still represent an important hazard in transfusion medicine. Therefore, some countries have introduced a systematic bedside ABO agglutination test checking that the right blood is given to the right patient. However, this strategy requires an extremely time-consuming learning programme and relies on a subjective interpretation of ABO test cards agglutination. We developed a prototype of a fully automated device performing the bedside agglutination test that could be completed by reading of a barcoded wristband. This POCT checks the ABO compatibility between the patient and the blood bag. Proof of concept and analytical validation of the prototype has been completed on 451 blood samples: 238 donor packed red blood cells, 137 consecutive unselected patients for whom a blood group determination had been ordered and on 76 patient samples selected with pathology that could possibly interfere with or impair performances of the assay. We observed 100% concordance for ABO blood groups between the POCT and the laboratory instrument. These preliminary results demonstrate the feasibility of ABO determination with a simple POCT device eliminating manipulation and subjective interpretation responsible for transfusion errors. This device should be linked to the blood bank system allowing all cross-check of the results. © 2015 International Society of Blood Transfusion.

NDA BATCH 2002-02

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

Lawrence Livermore National Laboratory

2009-12-09

QC sample results (daily background checks, 20-gram and 100-gram SGS drum checks) were within acceptable criteria established by WIPP's Quality Assurance Objectives for TRU Waste Characterization. Replicate runs were performed on 5 drums with IDs LL85101099TRU, LL85801147TRU, LL85801109TRU, LL85300999TRU and LL85500979TRU. All replicate measurement results are identical at the 95% confidence level as established by WIPP criteria. Note that the batch covered 5 weeks of SGS measurements from 23-Jan-2002 through 22-Feb-2002. Data packet for SGS Batch 2002-02 generated using gamma spectroscopy with the Pu Facility SGS unit is technically reasonable. All QC samples are in compliance with established control limits.more » The batch data packet has been reviewed for correctness, completeness, consistency and compliance with WIPP's Quality Assurance Objectives and determined to be acceptable. An Expert Review was performed on the data packet between 28-Feb-02 and 09-Jul-02 to check for potential U-235, Np-237 and Am-241 interferences and address drum cases where specific scan segments showed Se gamma ray transmissions for the 136-keV gamma to be below 0.1 %. Two drums in the batch showed Pu-238 at a relative mass ratio more than 2% of all the Pu isotopes.« less

Rp-phosphorothioate modifications in RNase P RNA that interfere with tRNA binding.

PubMed Central

Hardt, W D; Warnecke, J M; Erdmann, V A; Hartmann, R K

1995-01-01

We have used Rp-phosphorothioate modifications and a binding interference assay to analyse the role of phosphate oxygens in tRNA recognition by Escherichia coli ribonuclease P (RNase P) RNA. Total (100%) Rp-phosphorothioate modification at A, C or G positions of RNase P RNA strongly impaired tRNA binding and pre-tRNA processing, while effects were less pronounced at U positions. Partially modified E. coli RNase P RNAs were separated into tRNA binding and non-binding fractions by gel retardation. Rp-phosphorothioate modifications that interfered with tRNA binding were found 5' of nucleotides A67, G68, U69, C70, C71, G72, A130, A132, A248, A249, G300, A317, A330, A352, C353 and C354. Manganese rescue at positions U69, C70, A130 and A132 identified, for the first time, sites of direct metal ion coordination in RNase P RNA. Most sites of interference are at strongly conserved nucleotides and nine reside within a long-range base-pairing interaction present in all known RNase P RNAs. In contrast to RNase P RNA, 100% Rp-phosphorothioate substitutions in tRNA showed only moderate effects on binding to RNase P RNAs from E. coli, Bacillus subtilis and Chromatium vinosum, suggesting that pro-Rp phosphate oxygens of mature tRNA contribute relatively little to the formation of the tRNA-RNase P RNA complex. Images PMID:7540978

Global Visualization in Water using AnodizedAluminum PressureSensitive Paint and Dissolved Oxygen as Tracer

NASA Astrophysics Data System (ADS)

Ozaki, Tatsuya; Ishikawa, Hitoshi; Sakaue, Hirotaka

2009-11-01

We have developed anodized-aluminum pressuresensitive paint (AA-PSP) for flow visualization in water using dissolved oxygen as a tracer. Developed AA-PSP is characterized using water calibration setup by controlling a dissolved oxygen concentration. It is shown that the developed AA-PSP gives 4.0 percent change in luminescence per 1 mg/l of oxygen concentration. This AA-PSP is applied to visualize flows in a water tunnel. Oxygen concentrations of the water tunnel and the dissolved oxygen are 9.5 mg/l and 20 mg/l, respectively. We can capture horseshoe vortices over the base of 10 mm cylinder by using this technique at Reynolds number of 1000 and a water speed of 100 mm/s, respectively. Unlike conventional tracers such as ink, milk, and fluorescent dyes, this visualization technique gives flow information on the AA-PSP coated surface without integrating flows between the AA-PSP and an optical detector. Because of using dissolved oxygen as a tracer, it holds the material properties of testing water except for the amount of oxygen. The tracer does not interfere with optical measurements and it does not contaminate the testing water. A conventional visualization technique using milk as a tracer is also employed for comparison.

Analytical interference of HBOC-201 (Hemopure, a synthetic hemoglobin-based oxygen carrier) on four common clinical chemistry platforms.

PubMed

Korte, Erik A; Pozzi, Nicole; Wardrip, Nina; Ayyoubi, M Tayyeb; Jortani, Saeed A

2018-07-01

There are 13 million blood transfusions each year in the US. Limitations in the donor pool, storage capabilities, mass casualties, access in remote locations and reactivity of donors all limit the availability of transfusable blood products to patients. HBOC-201 (Hemopure®) is a second-generation glutaraldehyde-polymer of bovine hemoglobin, which can serve as an "oxygen bridge" to maintain oxygen carrying capacity while transfusion products are unavailable. Hemopure presents the advantages of extended shelf life, ambient storage, and limited reactive potential, but its extracellular location can also cause significant interference in modern laboratory analyzers similar to severe hemolysis. Observed error in 26 commonly measured analytes was determined on 4 different analytical platforms in plasma from a patient therapeutically transfused Hemopure as well as donor blood spiked with Hemopure at a level equivalent to the therapeutic loading dose (10% v/v). Significant negative error ratios >50% of the total allowable error (>0.5tAE) were reported in 23/104 assays (22.1%), positive bias of >0.5tAE in 26/104 assays (25.0%), and acceptable bias between -0.5tAE and 0.5tAE error ratio was reported in 44/104 (42.3%). Analysis failed in the presence of Hemopure in 11/104 (10.6%). Observed error is further subdivided by platform, wavelength, dilution and reaction method. Administration of Hemopure (or other hemoglobin-based oxygen carriers) presents a challenge to laboratorians tasked with analyzing patient specimens. We provide laboratorians with a reference to evaluate patient samples, select optimal analytical platforms for specific analytes, and predict possible bias beyond the 4 analytical platforms included in this study. Copyright © 2018 Elsevier B.V. All rights reserved.

AUTOFLUORESCENCE IN PRIMARY RAINBOW TROUT HEPATOCYTES INTERFERES WITH MEASUREMENT OF OXIDATIVE ACTIVITY VIA THE EXOGENOUS PROBE, DCF, BUT PROVIDES INTRINSIC MEASURE OF CELLULAR OXIDATIVE STATE

EPA Science Inventory

The compound 2', 7'-dichlorodihydrofluoroscein diacetate is a probe commonly used to detect oxidative activity in live cells. Studies were undertaken to measure reactive oxygen species generated in freshly isolated rainbow trout hepatocytes exposed to a variety of redox cycling c...

Error coding simulations

NASA Technical Reports Server (NTRS)

Noble, Viveca K.

1993-01-01

There are various elements such as radio frequency interference (RFI) which may induce errors in data being transmitted via a satellite communication link. When a transmission is affected by interference or other error-causing elements, the transmitted data becomes indecipherable. It becomes necessary to implement techniques to recover from these disturbances. The objective of this research is to develop software which simulates error control circuits and evaluate the performance of these modules in various bit error rate environments. The results of the evaluation provide the engineer with information which helps determine the optimal error control scheme. The Consultative Committee for Space Data Systems (CCSDS) recommends the use of Reed-Solomon (RS) and convolutional encoders and Viterbi and RS decoders for error correction. The use of forward error correction techniques greatly reduces the received signal to noise needed for a certain desired bit error rate. The use of concatenated coding, e.g. inner convolutional code and outer RS code, provides even greater coding gain. The 16-bit cyclic redundancy check (CRC) code is recommended by CCSDS for error detection.

The self streamlining wind tunnel. [wind tunnel walls

NASA Technical Reports Server (NTRS)

Goodyer, M. J.

1975-01-01

A two dimensional test section in a low speed wind tunnel capable of producing flow conditions free from wall interference is presented. Flexible top and bottom walls, and rigid sidewalls from which models were mounted spanning the tunnel are shown. All walls were unperforated, and the flexible walls were positioned by screw jacks. To eliminate wall interference, the wind tunnel itself supplied the information required in the streamlining process, when run with the model present. Measurements taken at the flexible walls were used by the tunnels computer check wall contours. Suitable adjustments based on streamlining criteria were then suggested by the computer. The streamlining criterion adopted when generating infinite flowfield conditions was a matching of static pressures in the test section at a wall with pressures computed for an imaginary inviscid flowfield passing over the outside of the same wall. Aerodynamic data taken on a cylindrical model operating under high blockage conditions are presented to illustrate the operation of the tunnel in its various modes.

Iterative decoding of SOVA and LDPC product code for bit-patterned media recoding

NASA Astrophysics Data System (ADS)

Jeong, Seongkwon; Lee, Jaejin

2018-05-01

The demand for high-density storage systems has increased due to the exponential growth of data. Bit-patterned media recording (BPMR) is one of the promising technologies to achieve the density of 1Tbit/in2 and higher. To increase the areal density in BPMR, the spacing between islands needs to be reduced, yet this aggravates inter-symbol interference and inter-track interference and degrades the bit error rate performance. In this paper, we propose a decision feedback scheme using low-density parity check (LDPC) product code for BPMR. This scheme can improve the decoding performance using an iterative approach with extrinsic information and log-likelihood ratio value between iterative soft output Viterbi algorithm and LDPC product code. Simulation results show that the proposed LDPC product code can offer 1.8dB and 2.3dB gains over the one LDPC code at the density of 2.5 and 3 Tb/in2, respectively, when bit error rate is 10-6.

A rapid Fourier-transform infrared (FTIR) spectroscopic method for direct quantification of paracetamol content in solid pharmaceutical formulations

NASA Astrophysics Data System (ADS)

Mallah, Muhammad Ali; Sherazi, Syed Tufail Hussain; Bhanger, Muhammad Iqbal; Mahesar, Sarfaraz Ahmed; Bajeer, Muhammad Ashraf

2015-04-01

A transmission FTIR spectroscopic method was developed for direct, inexpensive and fast quantification of paracetamol content in solid pharmaceutical formulations. In this method paracetamol content is directly analyzed without solvent extraction. KBr pellets were formulated for the acquisition of FTIR spectra in transmission mode. Two chemometric models: simple Beer's law and partial least squares employed over the spectral region of 1800-1000 cm-1 for quantification of paracetamol content had a regression coefficient of (R2) of 0.999. The limits of detection and quantification using FTIR spectroscopy were 0.005 mg g-1 and 0.018 mg g-1, respectively. Study for interference was also done to check effect of the excipients. There was no significant interference from the sample matrix. The results obviously showed the sensitivity of transmission FTIR spectroscopic method for pharmaceutical analysis. This method is green in the sense that it does not require large volumes of hazardous solvents or long run times and avoids prior sample preparation.

The role of test expectancy in the build-up of proactive interference in long-term memory.

PubMed

Weinstein, Yana; Gilmore, Adrian W; Szpunar, Karl K; McDermott, Kathleen B

2014-07-01

We examined the hypothesis that interpolated testing in a multiple list paradigm protects against proactive interference by sustaining test expectancy during encoding. In both experiments, recall on the last of 5 word lists was compared between 4 conditions: a tested group who had taken tests on all previous lists, an untested group who had not taken any tests on previous lists, and 2 other groups (one tested and the other untested) who were warned about the upcoming test prior to study of the fifth list. In both experiments, the untested/warned group performed significantly better than the untested/unwarned group on both correct recall and prior list intrusions but did not achieve the same recall accuracy as tested groups. In Experiment 2, an instruction manipulation check further narrowed the gap between the untested/warned group and the tested groups. In addition, we verified that a reduction in test expectancy indeed occurred in the untested group compared with the tested group by asking participants to indicate how likely they believed they were to receive a test on each studied list. These findings suggest that testing protects against proactive interference largely via attentional processes and/or more effective encoding. PsycINFO Database Record (c) 2014 APA, all rights reserved.

KSC-06pd0616

NASA Image and Video Library

2006-04-13

KENNEDY SPACE CENTER, FLA. - In the transfer aisle of the Vehicle Assembly Building, workers check the rim around the nose cap of external tank number 119, the tank designated for mission STS-121. The cap was removed in order to install a new gaseous oxygen vent valve underneath. Vapors are created prior to launch as the liquid oxygen in the external tank boils off. At the forward end of each external tank propellant tank is a vent and relief valve that can be opened before launch for venting or by excessive tank pressure for relief. The vent function is available only before launch. Mission STS-121 to the International Space Station is scheduled for launch in July. Photo credit: NASA/Jim Grossmann

Phosphine-functionalized graphene oxide, a high-performance electrocatalyst for oxygen reduction reaction

NASA Astrophysics Data System (ADS)

Ensafi, Ali A.; Golbon Haghighi, Mohsen; Jafari-Asl, Mehdi

2018-01-01

Here, a new approach for the synthesis of phosphine-functionalized graphene oxide (GO-PPh2) was developed. Using a simple method, diphenylphosphine group was linked to the hydroxyl group of OH-functionalized graphene that existing at the graphene surface. The electrochemical activity of GO-PPh2 for electrochemical oxygen reduction was checked. The results demonstrated that the new carbon hybrid material has a powerful potential for electrochemical oxygen reduction reaction (ORR). Moreover, GO-PPh2 as an electrocatalyst for ORR exhibited tolerance for methanol or ethanol as a result of crossover effect. In comparison with commercial Pt/C and Pt/rGO electrocatalysts, results showed that GO-PPh2 has a much higher selectivity, better durability, and much better electrochemical stability towards the ORR. The proposed method based on GO-PPh2 introduce an efficient electrocatalyst for further application in fuel cells.

Performance Analysis of a JTIDS/Link-16-type Waveform Transmitted over Slow, Flat Nakagami Fading Channels in the Presence of Narrowband Interference

DTIC Science & Technology

2008-12-01

The effective two-way tactical data rate is 3,060 bits per second. Note that there is no parity check or forward error correction (FEC) coding used in...of 1800 bits per second. With the use of FEC coding , the channel data rate is 2250 bits per second; however, the information data rate is still the...Link-11. If the parity bits are included, the channel data rate is 28,800 bps. If FEC coding is considered, the channel data rate is 59,520 bps

The application of LDPC code in MIMO-OFDM system

NASA Astrophysics Data System (ADS)

Liu, Ruian; Zeng, Beibei; Chen, Tingting; Liu, Nan; Yin, Ninghao

2018-03-01

The combination of MIMO and OFDM technology has become one of the key technologies of the fourth generation mobile communication., which can overcome the frequency selective fading of wireless channel, increase the system capacity and improve the frequency utilization. Error correcting coding introduced into the system can further improve its performance. LDPC (low density parity check) code is a kind of error correcting code which can improve system reliability and anti-interference ability, and the decoding is simple and easy to operate. This paper mainly discusses the application of LDPC code in MIMO-OFDM system.

Inorganic Salt Interference on CO2+ in Aerodyne AMS and ACSM Organic Aerosol Composition Studies.

PubMed

Pieber, Simone M; El Haddad, Imad; Slowik, Jay G; Canagaratna, Manjula R; Jayne, John T; Platt, Stephen M; Bozzetti, Carlo; Daellenbach, Kaspar R; Fröhlich, Roman; Vlachou, Athanasia; Klein, Felix; Dommen, Josef; Miljevic, Branka; Jiménez, José L; Worsnop, Douglas R; Baltensperger, Urs; Prévôt, André S H

2016-10-04

Aerodyne aerosol mass spectrometer (AMS) and Aerodyne aerosol chemical speciation monitor (ACSM) mass spectra are widely used to quantify organic aerosol (OA) elemental composition, oxidation state, and major environmental sources. The OA CO 2 + fragment is among the most important measurements for such analyses. Here, we show that a non-OA CO 2 + signal can arise from reactions on the particle vaporizer, ion chamber, or both, induced by thermal decomposition products of inorganic salts. In our tests (eight instruments, n = 29), ammonium nitrate (NH 4 NO 3 ) causes a median CO 2 + interference signal of +3.4% relative to nitrate. This interference is highly variable between instruments and with measurement history (percentiles P 10-90 = +0.4 to +10.2%). Other semi-refractory nitrate salts showed 2-10 times enhanced interference compared to that of NH 4 NO 3 , while the ammonium sulfate ((NH 4 ) 2 SO 4 ) induced interference was 3-10 times lower. Propagation of the CO 2 + interference to other ions during standard AMS and ACSM data analysis affects the calculated OA mass, mass spectra, molecular oxygen-to-carbon ratio (O/C), and f 44 . The resulting bias may be trivial for most ambient data sets but can be significant for aerosol with higher inorganic fractions (>50%), e.g., for low ambient temperatures, or laboratory experiments. The large variation between instruments makes it imperative to regularly quantify this effect on individual AMS and ACSM systems.

Effects of combined high intensity arm and leg training on performance and cardio-respiratory measures.

PubMed

Zinner, Christoph; Sperlich, Billy; Born, Dennis-Peter; Michels, Guido

2017-01-01

The purpose of this study was to investigate the effects of combined arm and leg high-intensity low-volume interval training (HIITarm+leg) on maximal oxygen uptake, myocardial measures (i.e. stroke volume, cardiac output, ejection fraction), Tissue Oxygenation Index (TOI) of the vastus lateralis and triceps brachii, as well as power output in comparison to leg HIIT (HIITleg) only. The 20 healthy, male and female volunteers completed six sessions of either HIITleg on a cycle ergometer or HIITarm+leg on an arm and leg cycle ergometer. During pre- and post-testing, the volunteers completed a submaximal and incremental test to exhaustion on a cycle ergometer. Magnitude based interference revealed likely to very likely beneficial effects for HIITarm+leg compared to HIITleg in maximal oxygen uptake, cardiac measures as well peak power output. The TOI following HIITarm+leg demonstrated likely to very likely increased oxygenation in the triceps brachii or the vastus lateralis when compared to HIITleg. The results suggest that six sessions of HIITarm+leg may likely to very likely improve maximal oxygen uptake, some inotropy-related cardiac measures with improved tissue oxygenation of the triceps brachii and vastus lateralis muscles resulting in greater leg peak power output.

Magnetic stability of oxygen defects on the SiO 2 surface

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

Adelstein, Nicole; Lee, Donghwa; DuBois, Jonathan L.

2017-02-21

The magnetic stability of E' centers and the peroxy radical on the surface of α-quartz is investigated with first-principles calculations to understand their role in magnetic flux noise in superconducting qubits (SQs) and superconducting quantum interference devices (SQUIDs) fabricated on amorphous silica substrates. Paramagnetic E' centers are common in both stoichiometric and oxygen deficient silica and quartz, and we calculate that they are more common on the surface than the bulk. However, we find the surface defects are magnetically stable in their paramagnetic ground state and thus will not contribute to 1/f noise through fluctuation at millikelvin temperatures.

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

Dholabhai, Pratik P., E-mail: pratik.dholabhai@asu.ed; Anwar, Shahriar, E-mail: anwar@asu.ed; Adams, James B., E-mail: jim.adams@asu.ed

Kinetic lattice Monte Carlo (KLMC) model is developed for investigating oxygen vacancy diffusion in praseodymium-doped ceria. The current approach uses a database of activation energies for oxygen vacancy migration, calculated using first-principles, for various migration pathways in praseodymium-doped ceria. Since the first-principles calculations revealed significant vacancy-vacancy repulsion, we investigate the importance of that effect by conducting simulations with and without a repulsive interaction. Initially, as dopant concentrations increase, vacancy concentration and thus conductivity increases. However, at higher concentrations, vacancies interfere and repel one another, and dopants trap vacancies, creating a 'traffic jam' that decreases conductivity, which is consistent with themore » experimental findings. The modeled effective activation energy for vacancy migration slightly increased with increasing dopant concentration in qualitative agreement with the experiment. The current methodology comprising a blend of first-principle calculations and KLMC model provides a very powerful fundamental tool for predicting the optimal dopant concentration in ceria related materials. -- graphical abstract: Ionic conductivity in praseodymium doped ceria as a function of dopant concentration calculated using the kinetic lattice Monte Carlo vacancy-repelling model, which predicts the optimal composition for achieving maximum conductivity. Display Omitted Research highlights: {yields} KLMC method calculates the accurate time-dependent diffusion of oxygen vacancies. {yields} KLMC-VR model predicts a dopant concentration of {approx}15-20% to be optimal in PDC. {yields} At higher dopant concentration, vacancies interfere and repel one another, and dopants trap vacancies. {yields} Activation energy for vacancy migration increases as a function of dopant content« less

Atomic oxygen dynamics in an air dielectric barrier discharge: a combined diagnostic and modeling approach

NASA Astrophysics Data System (ADS)

Baldus, Sabrina; Schröder, Daniel; Bibinov, Nikita; Schulz-von der Gathen, Volker; Awakowicz, Peter

2015-06-01

Cold atmospheric pressure plasmas are a promising alternative therapy for treatment of chronic wounds, as they have already shown in clinical trials. In this study an air dielectric barrier discharge (DBD) developed for therapeutic use in dermatology is characterized with respect to the plasma produced reactive oxygen species, namely atomic oxygen and ozone, which are known to be of great importance to wound healing. To understand the plasma chemistry of the applied DBD, xenon-calibrated two-photon laser-induced fluorescence spectroscopy and optical absorption spectroscopy are applied. The measured spatial distributions are shown and compared to each other. A model of the afterglow chemistry based on optical emission spectroscopy is developed to cross-check the measurement results and obtain insight into the dynamics of the considered reactive oxygen species. The atomic oxygen density is found to be located mostly between the electrodes with a maximum density of {{n}\\text{O}}=6× {{10}16} cm-3 . Time resolved measurements reveal a constant atomic oxygen density between two high voltage pulses. The ozone is measured up to 3 mm outside the active plasma volume, reaching a maximum value of {{n}{{\\text{O}3}}}=3× {{10}16} cm-3 between the electrodes.

Efficacy of photodynamic therapy against Streptococcus mutans biofilm: Role of singlet oxygen.

PubMed

Misba, Lama; Zaidi, Sahar; Khan, Asad U

2018-06-01

In photodynamic therapy (PDT), killing is entirely based on the ROS generation and among different types of ROS generated during PDT, singlet oxygen is considered as the most potential as illustrated in many studies and therefore it is predominantly responsible for photodamage and cytotoxic reactions. The aim of this study was to check whether singlet oxygen (Type II photochemistry) is more potential than free radicals (Type I photochemistry) against Streptococcus mutans biofilm. We have taken two phenothiazinium dyes i.e. toluidine blue O (TBO) and new methylene blue (NMB). TBO was found to have better antibacterial as well as antibiofilm effect than NMB. Antibacterial effect was evaluated by colony forming unit while antibiofilm action by crystal violet and congo red binding assays. We have also evaluated the disruption of preformed biofilm by biofilm reduction assay, confocal laser electron and scanning electron microscopy. More singlet oxygen production was detected in case of TBO than NMB while more Free radical (HO) was produced by NMB than TBO. TBO showed better antibacterial as well as antibiofilm effect than NMB so; we conclude that potency of a photosensitizer is correlated with the capability to produce singlet oxygen. Copyright © 2018 Elsevier B.V. All rights reserved.

Spin-labeled small unilamellar vesicles with the T1-sensitive saturation-recovery EPR display as an oxygen sensitive analyte for measurement of cellular respiration

PubMed Central

Mainali, Laxman; Vasquez-Vivar, Jeannette; Hyde, James S.; Subczynski, Witold K.

2015-01-01

This study validated the use of small unilamellar vesicles (SUVs) made of 1-palmitoyl-2-oleoylphosphatidylcholine with 1 mol% spin label of 1-palmitoyl-2-(16-doxylstearoyl)phosphatidylcholine (16-PC) as an oxygen sensitive analyte to study cellular respiration. In the analyte the hydrocarbon environment surrounds the nitroxide moiety of 16-PC. This ensures high oxygen concentration and oxygen diffusion at the location of the nitroxide as well as isolation of the nitroxide moiety from cellular reductants and paramagnetic ions that might interfere with spin-label oximetry measurements. The saturation-recovery EPR approach was applied in the analysis since this approach is the most direct method to carry out oximetric studies. It was shown that this display (spin-lattice relaxation rate) is linear in oxygen partial pressure up to 100% air (159 mmHg). Experiments using a neuronal cell line in suspension were carried out at X-band for closed chamber geometry. Oxygen consumption rates showed a linear dependence on the number of cells. Other significant benefits of the analyte are: the fast effective rotational diffusion and slow translational diffusion of the spin-probe is favorable for the measurements, and there is no cross reactivity between oxygen and paramagnetic ions in the lipid bilayer. PMID:26441482

Spin-labeled small unilamellar vesicles with the T1-sensitive saturation-recovery EPR display as an oxygen sensitive analyte for measurement of cellular respiration.

PubMed

Mainali, Laxman; Vasquez-Vivar, Jeannette; Hyde, James S; Subczynski, Witold K

2015-08-01

This study validated the use of small unilamellar vesicles (SUVs) made of 1-palmitoyl-2-oleoylphosphatidylcholine with 1 mol% spin label of 1-palmitoyl-2-(16-doxylstearoyl)phosphatidylcholine (16-PC) as an oxygen sensitive analyte to study cellular respiration. In the analyte the hydrocarbon environment surrounds the nitroxide moiety of 16-PC. This ensures high oxygen concentration and oxygen diffusion at the location of the nitroxide as well as isolation of the nitroxide moiety from cellular reductants and paramagnetic ions that might interfere with spin-label oximetry measurements. The saturation-recovery EPR approach was applied in the analysis since this approach is the most direct method to carry out oximetric studies. It was shown that this display (spin-lattice relaxation rate) is linear in oxygen partial pressure up to 100% air (159 mmHg). Experiments using a neuronal cell line in suspension were carried out at X-band for closed chamber geometry. Oxygen consumption rates showed a linear dependence on the number of cells. Other significant benefits of the analyte are: the fast effective rotational diffusion and slow translational diffusion of the spin-probe is favorable for the measurements, and there is no cross reactivity between oxygen and paramagnetic ions in the lipid bilayer.

Thermal Theory of Combustion and Explosion. 3; Theory of Normal Flame Propagation

NASA Technical Reports Server (NTRS)

Semenov, N. N.

1942-01-01

The technical memorandum covers experimental data on flame propagation, the velocity of flame propagation, analysis of the old theoretical views of flame propagation, confirmation of the theory for simple reactions (theory of combustion of explosive substances and in particular nitroglycol), and check of the theory by example of a chain oxidizing reaction (theory of flame propagation in carbon monoxide, air and carbon monoxide - oxygen mixtures).

Insight into Cr6+ reduction efficiency of Rhodococcus erythropolis isolated from coalmine waste water.

PubMed

Banerjee, Soumya; Joshi, S R; Mandal, Tamal; Halder, Gopinath

2017-01-01

A microbial treatment of Cr 6+ contaminated wastewater with a chromium reducing bacteria isolated from coal mine area was investigated. In a series of batch study metal removal was executed under different parametric conditions which include pH (2-7), temperature (20-50 °C), initial Cr 6+ concentration (1-100 mg/L), substrate utilization and its overall effect on biomass generation. Impact of oxygen availability was checked at different agitation speed and its role on the remedial process. Liquid phase reduction of Cr 6+ was measured in terms of substrate reduction and total biomass yield. The bacterium species isolated was able to tolerate Cr 6+ over a wide range from 1 to 100 mg/L before it reached minimum inhibition concentration. Apart from Cr 6+ , the bacterial isolate showed tolerance towards Fe, As, Cu, Ag, Zn, Mn, Mg and Pb. Removal mechanism adopted by the bacterium recommended that it employed accumulation of Cr 6+ as Cr 3+ both within and outside the cell. Classical Monod equation was used to determine the biokinetics of the bacterial isolate along with the interference of metal ion concentration and substrate utilization. Cr 6+ removal was found prominent even in bimetallic solutions. The bacterial isolate was confirmed to be Rhodococcus erythopolis by 16s rRNA molecular characterization. Thus the bacterial isolate obtained from the coal mine area proved to be a potential agent for microbial remediation of Cr 6+ laden waste water. Copyright © 2016 Elsevier Ltd. All rights reserved.

Antagonistic Activity of Lactobacillus Isolates against Salmonella typhi In Vitro

PubMed Central

Abdel-Daim, Amira; Hassouna, Nadia; Hafez, Mohamed; Ashor, Mohamed Seif Aldeen; Aboulwafa, Mohammad M.

2013-01-01

Background. Enteric fever is a global health problem, and rapidly developing resistance to various drugs makes the situation more alarming. The potential use of Lactobacillus to control typhoid fever represents a promising approach, as it may exert protective actions through various mechanisms. Methods. In this study, the probiotic potential and antagonistic activities of 32 Lactobacillus isolates against Salmonella typhi were evaluated. The antimicrobial activity of cell free supernatants of Lactobacillus isolates, interference of Lactobacillus isolates with the Salmonella adherence and invasion, cytoprotective effect of Lactobacillus isolates, and possibility of concurrent use of tested Lactobacillus isolates and antibiotics were evaluated by testing their susceptibilities to antimicrobial agents, and their oxygen tolerance was also examined. Results. The results revealed that twelve Lactobacillus isolates could protect against Salmonella typhi infection through interference with both its growth and its virulence properties, such as adherence, invasion, and cytotoxicity. These Lactobacillus isolates exhibited MIC values for ciprofloxacin higher than those of Salmonella typhi and oxygen tolerance and were identified as Lactobacillus plantarum. Conclusion. The tested Lactobacillus plantarum isolates can be introduced as potential novel candidates that have to be subjected for in vivo and application studies for treatment and control of typhoid fever. PMID:24191248

Analytical interferences in point-of-care testing glucometers by icodextrin and its metabolites: an overview.

PubMed

Floré, Katelijne M J; Delanghe, Joris R

2009-01-01

Current point-of-care testing (POCT) glucometers are based on various test principles. Two major method groups dominate the market: glucose oxidase-based systems and glucose dehydrogenase-based systems using pyrroloquinoline quinone (GDH-PQQ) as a cofactor. The GDH-PQQ-based glucometers are replacing the older glucose oxidase-based systems because of their lower sensitivity for oxygen. On the other hand, the GDH-PQQ test method results in falsely elevated blood glucose levels in peritoneal dialysis patients receiving solutions containing icodextrin (e.g., Extraneal; Baxter, Brussels, Belgium). Icodextrin is metabolized in the systemic circulation into different glucose polymers, but mainly maltose, which interferes with the GDH-PQQ-based method. Clinicians should be aware of this analytical interference. The POCT glucometers based on the GDH-PQQ method should preferably not be used in this high-risk population and POCT glucose results inconsistent with clinical suspicion of hypoglycemic coma should be retested with another testing system.

ICP-MS multielemental determination of metals potentially released from dental implants and articular prostheses in human biological fluids.

PubMed

Sarmiento-González, Alejandro; Marchante-Gayón, Juan Manuel; Tejerina-Lobo, José María; Paz-Jiménez, José; Sanz-Medel, Alfredo

2005-06-01

A sector field high-resolution (HR)-ICP-MS and an octapole reaction system (ORS)-ICP-MS have been compared for the simultaneous determination of traces of metals (Ti, V, Cr, Co, Ni, and Mo) released from dental implants and articular prostheses in human biological fluids. Optimum sample treatments were evaluated to minimize matrix effects in urine and whole blood. Urine samples were diluted tenfold with ultrapure water, whereas whole blood samples were digested with high-purity nitric acid and hydrogen peroxide and finally diluted tenfold with ultrapure water. In both matrices, internal standardization (Ga and Y) was employed to avoid potential matrix interferences and ICP-MS signal drift. Spectral interferences arising from the plasma gases or the major components of urine and whole blood were identified by (HR)-ICP-MS at 3,000 resolving power. The capabilities of (HR)-ICP-MS and (ORS)-ICP-MS for the removal of such spectral interferences were evaluated and compared. Results indicate that polyatomic interferences, which hamper the determination of such metallic elements in these biological samples, could be overcome by using a resolving power of 3,000. Using (ORS)-ICP-MS, all those elements could be quantified except Ti and V (due to the polyatomic ions 31P16O and 35Cl16O, respectively). The accuracy of the proposed methodologies by (HR)- and (ORS)-ICP-MS was checked against two reference materials. Good agreement between the given values and the concentrations obtained for all the analytes under scrutiny was found except for Ti and V when analyzed by (ORS)-ICP-MS.

Performance evaluation of oxygen adsorbents using negative corona discharge-ion mobility spectrometry.

PubMed

Azadkish, Kamal; Jafari, Mohammad T; Ghaziaskar, Hassan S

2017-02-08

Trace amounts of oxygen was determined using negative corona discharge as an ionization source for ion mobility spectrometry. A point-in-cylinder geometry with novel design was used to establish the corona discharge without interferences of negative ions such as NO X - . The desirable background spectrum shows only electrons peak, providing the instrument capable of trace analysis of oxygen in gaseous samples. The limit of detection and linear dynamic range with high coefficient of determination (r 2  = 0.9997), were obtained for oxygen as 8.5 and 28-14204 ppm, respectively. The relative standard deviations of the method for intraday and interday were obtained 4 and 11%, respectively. The satisfactory results revealed the ability of the negative corona discharge ion mobility spectrometry for investigating the performance of synthesized oxygen adsorbents in nitrogen streams. Two oxygen scavengers of MnO and Cu powder were prepared and the optimum temperature of the reactor containing MnO and Cu powder were obtained as 180 and 230 °C, respectively. Due to higher lifetime of copper powder, it was selected as the oxygen scavenger and some parameters such as: the type of adsorbent support, the size of adsorbent particles, and the amount of copper were studied for preparation of more efficient oxygen adsorbent. Copyright © 2016 Elsevier B.V. All rights reserved.

Soft-Decision-Data Reshuffle to Mitigate Pulsed Radio Frequency Interference Impact on Low-Density-Parity-Check Code Performance

NASA Technical Reports Server (NTRS)

Ni, Jianjun David

2011-01-01

This presentation briefly discusses a research effort on mitigation techniques of pulsed radio frequency interference (RFI) on a Low-Density-Parity-Check (LDPC) code. This problem is of considerable interest in the context of providing reliable communications to the space vehicle which might suffer severe degradation due to pulsed RFI sources such as large radars. The LDPC code is one of modern forward-error-correction (FEC) codes which have the decoding performance to approach the Shannon Limit. The LDPC code studied here is the AR4JA (2048, 1024) code recommended by the Consultative Committee for Space Data Systems (CCSDS) and it has been chosen for some spacecraft design. Even though this code is designed as a powerful FEC code in the additive white Gaussian noise channel, simulation data and test results show that the performance of this LDPC decoder is severely degraded when exposed to the pulsed RFI specified in the spacecraft s transponder specifications. An analysis work (through modeling and simulation) has been conducted to evaluate the impact of the pulsed RFI and a few implemental techniques have been investigated to mitigate the pulsed RFI impact by reshuffling the soft-decision-data available at the input of the LDPC decoder. The simulation results show that the LDPC decoding performance of codeword error rate (CWER) under pulsed RFI can be improved up to four orders of magnitude through a simple soft-decision-data reshuffle scheme. This study reveals that an error floor of LDPC decoding performance appears around CWER=1E-4 when the proposed technique is applied to mitigate the pulsed RFI impact. The mechanism causing this error floor remains unknown, further investigation is necessary.

A Baseline Air Quality Assessment Onboard a Victoria Class Submarine: HMCS Windsor

DTIC Science & Technology

2006-05-01

with the use of the Carbon Dioxide Absorption Units (CDAUs) in which two canisters were initiated in both the Fore Ends (foreword of Bulkhead 34 in...monitoring equipment used onboard was also checked as a confirmation. Carbon Monoxide is produced as a result of combustion, therefore the source of...aim the study monitored the effects of: air purification capabilities (management of Oxygen (O2) and Carbon Dioxide (CO2)); routine housekeeping

Assessing the Health Effects of Blast Injuries and Embedded Metal Fragments

DTIC Science & Technology

2017-10-01

isoflurane and open oxygen tank valve (check psi) Prep Vetbond, buprenorphine, 1 ml syringes and #10 scalpel blades In the vivarium, weigh each...with #10 blade over gastrocnemius Inject pellets into muscle tissue using 14 or 16 gauge needle and plunger (one at a time) Repeat incision and...Fluovac canister and record on adsorber canister (dispose of canister at 1400 grams) Clean clippers in Blade Wash, wipe down with isopropyl alcohol, then

KSC-01pp0953

NASA Image and Video Library

2001-05-07

KENNEDY SPACE CENTER, FLA. -- In the Operations and Checkout Building, workers check out the placement of one of four gas tanks on the Spacelab Logistics Double Pallet. Part of the STS-104 payload, the storage tanks two gaseous oxygen and two gaseous nitrogen comprise the high pressure gas assembly that will be attached to the Joint Airlock Module during two spacewalks. The tanks will support future spacewalk operations from the Station and augment the Service Module gas resupply system

Registering upper atmosphere parameters in East Siberia with Fabry—Perot Interferometer KEO Scientific "Arinae"

NASA Astrophysics Data System (ADS)

Vasilyev, Roman; Artamonov, Maksim; Beletsky, Aleksandr; Zherebtsov, Geliy; Medvedeva, Irina; Mikhalev, Aleksandr; Syrenova, Tatyana

2017-09-01

We describe the Fabry–Perot interferometer designed to study Earth’s upper atmosphere. We propose a modification of the existing data processing method for determining the Doppler shift and Doppler widening and also for separating the observed line intensity and the background intensity. The temperature and wind velocity derived from these parameters are compared with physical characteristics obtained from modeling (NRLMSISE-00, HWM14). We demonstrate that the temperature is determined from the oxygen 630 nm line irrespective of the hydroxyl signal existing in interference patterns. We show that the interferometer can obtain temperature from the oxygen 557.7 nm line in case of additional calibration of the device. The observed wind velocity mainly agrees with model data. Night variations in the red and green oxygen lines quite well coincide with those in intensities obtained by devices installed nearby the interferometer.

Reduction of potential food interference in two sympatric carnivores by sequential use of shared resources

NASA Astrophysics Data System (ADS)

Barrientos, Rafael; Virgós, Emilio

2006-07-01

The common genet ( Genetta genetta) and the stone marten ( Martes foina) are two species that overlap extensively in their distribution ranges in southwest Europe. Available diet data from these species allow us to predict some interference competition for food resources in sympatric populations. We checked the food interference hypothesis in a sympatric population. The diet of both predators was analyzed through scat collection. Seasonal differences in biomass consumption were compared between both species in those items considered as key resources according to biomass consumption. Strawberry tree fruits can be considered as key resource exclusively for genets whereas fungi, blackberries and rabbits are keys for stone martens only. For other key resources consumed by both species (wood mouse and figs) we suggest that a possible mechanism to reduce diet overlap could be the sequential use of these resources: no intensive exploitation by both species of the same key resource during the same season was detected. Figs and wood mouse were used alternatively. Although strawberry tree fruits and blackberry are exclusive key resources of one of the species, their consumptions showed the same pattern. Diet niche overlap in our study is low compared with other carnivore communities suggesting that exclusive use of some key resources and sequential use of shared ones is an optimal scenario to reduce overall competition for food resources.

1H nuclear magnetic resonance studies of sarcoplasmic oxygenation in the red cell-perfused rat heart.

PubMed

Jelicks, L A; Wittenberg, B A

1995-05-01

The proximal histidine N delta H proton of deoxymyoglobin experiences a large hyperfine shift resulting in its 1H nuclear magnetic resonance (NMR) signal appearing at approximately 76 ppm (at 35 degrees C), downfield of the diamagnetic spectral region. 1H NMR of this proton is used to monitor sarcoplasmic oxygen pressure in isolated perfused rat heart. This method monitors intracellular oxygenation in the whole heart and does not reflect oxygenation in a limited region. The deoxymyoglobin resonance intensity is reduced upon conversion of myoglobin to the ferric form by sodium nitrite. 1H resonances of the N delta H protons of the alpha and beta subunits of bovine deoxyhemoglobin do not interfere with the measurement of myoglobin deoxygenation in blood-perfused rat heart. We find that steady-state myoglobin deoxygenation is increased progressively (and reversibly) as oxygenation of the perfusing medium is decreased in both saline and red blood cell-perfused hearts at constant work output. An eightfold increase in the heart rate of the blood-perfused heart resulted in no change in the deoxymyoglobin signal intensity. Intracellular PO2 of myoglobin-containing cells is maintained remarkably constant in changing work states.

MWCNT-ruthenium oxide composite paste electrode as non-enzymatic glucose sensor.

PubMed

Tehrani, Ramin M A; Ab Ghani, Sulaiman

2012-01-01

A non-enzymatic glucose sensor of multi-walled carbon nanotube-ruthenium oxide/composite paste electrode (MWCNT-RuO(2)/CPE) was developed. The electrode was characterized by using XRD, SEM, TEM and EIS. Meanwhile, cyclic voltammetry and amperometry were used to check on the performances of the MWCNT-RuO(2)/CPE towards glucose. The proposed electrode has displayed a synergistic effect of RuO(2) and MWCNT on the electrocatalytic oxidation of glucose in 3M NaOH. This was possible via the formation of transitions of two redox pairs, viz. Ru(VI)/Ru(IV) and Ru(VII)/Ru(VI). A linear range of 0.5-50mM glucose and a limit of detection of 33 μM glucose (S/N=3) were observed. There was no significant interference observable from the traditional interferences, viz. ascorbic acid and uric acid. Indeed, results so obtained have indicated that the developed MWCNT-RuO(2)/CPE would pave the way for a better future to glucose sensor development as its fabrication was without the use of any enzyme. Copyright © 2012 Elsevier B.V. All rights reserved.

On-line removal of redox-active interferents by a porous electrode before amperometric blood glucose determination.

PubMed

Deng, Chunyan; Peng, Yong; Su, Lei; Liu, You-Nian; Zhou, Feimeng

2012-03-16

A porous reticulated vitreous carbon (RVC) electrode and a disk electrode coupled in tandem in an electrochemical flow cell has been used for electrolytic removal of interferents before amperometric glucose detection. The electrolytic efficiency at the upstream RVC electrode is 100% at a flow rate of 0.1 mL min(-1) or lower. Potential interferents such as acetaminophen, ascorbic acid, and uric acid can be completely eliminated by electrolysis at the RVC electrode. A mixed monolayer comprising glucose oxidase (GOD) and ferrocenyl-1-undecanethiol preformed at the downstream gold disk electrode was used as a mediator-based amperometric glucose sensor. The dependence of the amperometric current on the glucose concentration exhibits good linearity across over three orders of magnitude. The glucose measurements were also found to be reproducible (RSD<3.5%) and accurate. Unlike the chemiluminescence method, this device obviates the use of carcinogenic substrates and the glucose sensor performance is independent of the oxygen present in sample. On the basis that the RVC electrode requires minimal cleanup and the GOD-modified electrode remains stable for a week, the electrochemical flow cell should be amenable for automated on-line removal of redox interferents for other types of enzyme-based biosensors. Copyright © 2012 Elsevier B.V. All rights reserved.

Oxygen isotopes in nitrite: Analysis, calibration, and equilibration

USGS Publications Warehouse

Casciotti, K.L.; Böhlke, J.K.; McIlvin, M.R.; Mroczkowski, S.J.; Hannon, J.E.

2007-01-01

Nitrite is a central intermediate in the nitrogen cycle and can persist in significant concentrations in ocean waters, sediment pore waters, and terrestrial groundwaters. To fully interpret the effect of microbial processes on nitrate (NO3-), nitrite (NO2-), and nitrous oxide (N2O) cycling in these systems, the nitrite pool must be accessible to isotopic analysis. Furthermore, because nitrite interferes with most methods of nitrate isotopic analysis, accurate isotopic analysis of nitrite is essential for correct measurement of nitrate isotopes in a sample that contains nitrite. In this study, nitrite salts with varying oxygen isotopic compositions were prepared and calibrated and then used to test the denitrifier method for nitrite oxygen isotopic analysis. The oxygen isotopic fractionation during nitrite reduction to N2O by Pseudomonas aureofaciens was lower than for nitrate conversion to N2O, while oxygen isotopic exchange between nitrite and water during the reaction was similar. These results enable the extension of the denitrifier method to oxygen isotopic analysis of nitrite (in the absence of nitrate) and correction of nitrate isotopes for the presence of nitrite in “mixed” samples. We tested storage conditions for seawater and freshwater samples that contain nitrite and provide recommendations for accurate oxygen isotopic analysis of nitrite by any method. Finally, we report preliminary results on the equilibrium isotope effect between nitrite and water, which can play an important role in determining the oxygen isotopic value of nitrite where equilibration with water is significant.

The effect of extremely high glucose concentrations on 21 routine chemistry and thyroid Abbott assays: interference study.

PubMed

Çuhadar, Serap; Köseoğlu, Mehmet; Çinpolat, Yasemin; Buğdaycı, Güler; Usta, Murat; Semerci, Tuna

2016-01-01

Extremely high glucose concentrations have been shown to interfere with creatinine assays especially with Jaffe method in peritoneal dialysate. Because diabetes is the fastest growing chronic disease in the world, laboratories study with varying glucose concentrations. We investigated whether different levels of glucose spiked in serum interfere with 21 routine chemistry and thyroid assays at glucose concentrations between 17-51 mmol/L. Baseline (group I) serum pool with glucose concentration of 5.55 (5.44-5.61) mmol/L was prepared from patient sera. Spiking with 20% dextrose solution, sample groups were obtained with glucose concentrations: 17.09, 34.52, and 50.95 mmol/L (group II, III, IV, respectively). Total of 21 biochemistry analytes and thyroid tests were studied on Abbott c8000 and i2000sr with commercial reagents. Bias from baseline value was checked statistically and clinically. Creatinine increased significantly by 8.74%, 31.66%, 55.31% at groups II, III, IV, respectively with P values of < 0.001. At the median glucose concentration of 50.95 mmol/L, calcium, albumin, chloride and FT4 biased significantly clinically (-0.85%, 1.63%, 0.65%, 7.4% with P values 0.138, 0.214, 0.004, < 0.001, respectively). Remaining assays were free of interference. Among the numerous biochemical parameters studied, only a few parameters are affected by dramatically increased glucose concentration. The creatinine measurements obtained in human sera with the Jaffe alkaline method at high glucose concentrations should be interpreted with caution. Other tests that were affected with extremely high glucose concentrations were calcium, albumin, chloride and FT4, hence results should be taken into consideration in patients with poor diabetic control.

[Return to work of a pacemaker bearing worker: the relationship between health problems and electromagnetic interferences].

PubMed

Taino, G; Frigerio, F

2004-01-01

The potential effects of electromagnetic fields is a problem that interest the public opinion, as the modern society expose all people to electromagnetic non ionizing radiations. The problem has a particular and important meaning facing the return to normal life and work conditions of a cardiopatic subject bearing a pacemaker (PM) or implantable cardioverter defibrillator (ICD). Electromagnetic interferences can produce temporary or permanent malfunctions in these devices. Checking for the absence of electromagnetic interferences is necessary considering that correct functioning of these medical devices is essential for the life of the bearer. Precautions normally adopted by these subjects are generally adequate to ensure protection from interferences present in life environment; for occupational environment, there is often lack of adequate information, also due to late involving of the doctor specialist in occupational health. This work intends to study in depth a specific job, a carpentry-workshop with welding activities, starting with a case of a PM bearer who asked a doctor specialist in occupational health to evaluate the problems involved in his return to work. Electric and magnetic fields produced by equipments present in the workshop were measured and compared to data supplied by the literature to evaluate the possibility of interactions in the normally functioning of implanted electronic devices. On the basis of our experience, we have found some criterions for specific risk assessement to adopt for the definition of operative protocols for return to work of PM or ICD carriers, also considering the lack of specific procedures and indications for the doctor specialist in occupational health. The collected information and data from the literature suggest that welding can be a risk for a subject with PM; as observed in experimental conditions, electromagnetic radiations can alter particular sensitive devices and those with uncorrected settings.

Indagation of serum and salivary reactive oxygen metabolite and cortisol levels in chronic periodontitis and stress-induced chronic periodontitis patients.

PubMed

Sudhakar, Uma; Thyagarajan, Ramakrishnan; Jeyapal, Bhagyameena; Jagadeesh, Sushuruthi; Jayakumar, Parvathee

2017-01-01

Periodontal disease is not a conventional bacterial infection but is an inflammatory disease initiated by immune response against a group of microorganisms in susceptible hosts. There are many intriguing researches that unfold the secrets of chronic periodontitis. The current researches in chronic periodontitis are directed toward an approach that respects the scientific relationship between the various risk factors, the genetic factors, and the progression of the disease. This study aims to evaluate the cortisol and reactive oxygen metabolites (ROM) concentration in serum and to find out their association in periodontal health and disease. In this study, totally thirty patients have been taken and divided into two groups of chronic periodontitis (Group I) and stress-induced chronic periodontitis (Group II) and evaluated the correlation between the ROM and cortisol levels in them. This is the first study, where both the levels of ROM and cortisol are checked in the serum and saliva. The analysis is done to check the association between them. The data were statistically analyzed using software program (SPSSV 16), Pearson correlation, and paired t -test. Comparison of the mean ROM levels in Group I and Group II showed that mean ROM level in Group II is highly significant than Group I. Our study suggests that stress can have a role in the progression of periodontal disease by increasing the cortisol and ROM levels.

Noninvasive Sensor for Measuring Muscle Metabolism During Exercise

NASA Technical Reports Server (NTRS)

Soller, B. R.; Yang, Y.; Lee, S. M. C.; Soyemi, O. O.; Wilson, C.; Hagan, R. D.

2007-01-01

The measurement of oxygen uptake (VO2) and lactate threshold (LT) are utilized to assess changes in aerobic capacity and the efficacy of exercise countermeasures in astronauts. During extravehicular activity (EVA), real-time knowledge of VO2 and relative work intensity can be used to monitor crew activity levels and organize tasks to reduce the cumulative effects of fatigue. Currently VO2 and LT are determined with complicated measurement techniques that require sampling of expired ventilatory gases, which may not be accurate in enclosed, oxygen-rich environments such as the EVA suit. The UMMS team has developed a novel near infrared spectroscopic (NIRS) system which noninvasively, simultaneously and continuously measures muscle oxygen tension, oxygen saturation, pH (pHm), and hematocrit from a small sensor placed on the leg. This system is unique in that it allows accurate, absolute measurement of these parameters in the thigh muscle by correcting spectra for the interference from skin pigment and fat. These parameters can be used to estimate VO2 and LT. A preliminary evaluation of the system s capabilities was performed in the NASA JSC Exercise Physiology Lab.

A computer program for geochemical analysis of acid-rain and other low-ionic-strength, acidic waters

USGS Publications Warehouse

Johnsson, P.A.; Lord, D.G.

1987-01-01

ARCHEM, a computer program written in FORTRAN 77, is designed primarily for use in the routine geochemical interpretation of low-ionic-strength, acidic waters. On the basis of chemical analyses of the water, and either laboratory or field determinations of pH, temperature, and dissolved oxygen, the program calculates the equilibrium distribution of major inorganic aqueous species and of inorganic aluminum complexes. The concentration of the organic anion is estimated from the dissolved organic concentration. Ionic ferrous iron is calculated from the dissolved oxygen concentration. Ionic balances and comparisons of computed with measured specific conductances are performed as checks on the analytical accuracy of chemical analyses. ARCHEM may be tailored easily to fit different sampling protocols, and may be run on multiple sample analyses. (Author 's abstract)

Application of ICP-MS as a multi-element detector for sulfur and metal hydride impurities in hydrocarbon matrices.

PubMed

Geiger, William M; McSheehy, Shona; Nash, Martin J

2007-01-01

Maturation of inductively coupled plasma-mass spectrometry (ICP-MS) in terms of size, reliability, and cost has had a significant impact on its consideration as a viable detector for gas chromatography. Its generally excellent sensitivity for those elements it can measure has been a contributing factor. A method for sulfur speciation in various hydrocarbon products is investigated, as well as sulfur and metal hydride contaminants in high purity hydrocarbon feed stocks. Detection limits for sulfur species in hydrocarbon liquids and gases are approximately 5 and 10 ppb, respectively, as sulfur. Lower detection limits on the order of 100 parts per trillion are achieved for arsine. The use of collision cell technology (CCT) is exploited to remove interferences. CCT has been described elsewhere (1) using helium or helium-hydrogen mixtures for suppression of (16)O(16)O(+) interference with (32)S. In this work, a novel approach is investigated which uses oxygen to remove this interference by shifting it in a comprehensive fashion. The advantage of operating the system at full power with a tandem gas and liquid interface is also discussed.

Reconciling water harvesting and soil erosion control by thoughtful implementation of SWC measures

NASA Astrophysics Data System (ADS)

Bellin, N.; Vanacker, V.; van Wesemael, B.

2012-04-01

Soil and water conservation (SWC) structures are largely present in Southeast Spain. Traditionally, SWC structures such as step terraces and earthen check dams were implemented in agricultural fields. They are usually found in semi-arid traditional rainfed agricultural systems that heavily rely on SWC structures to supplement the sparse rainfall. The on-site SWC measures favor water infiltration and reduce water runoff and soil erosion. In the river system (off site), large concrete/gabion check dams have been constructed since the 70's. The analysis of orthophotographs and field survey observations indicate a severe decay of on-site SWC structures in the agricultural area. This has been observed for the Cárcavo catchment (Murcia). The density of step terraces and check dams decreased by 25% between 1956 and 2005. Changes in the agricultural area can be summarized as: (i) rapid expansion of rainfed crops in marginal areas and (ii) mechanization of agriculture associated with frequent tillage operations. It became evident that the high density of SWC structures has now become a nuisance in rainfed orchards that are maintained by regular shallow tillage. We constrained the effects of SWC structures on hydrological connectivity by assessing their functioning during a heavy storm (return period 8.2 yrs in 2006). The percentage of cropland draining directly on the river system without interference of a check dam has increased from 9% in 1956 to 31% in 2005 and 40 % after the storm in November 2006. While there is a strong decrease of traditional SWC structures, several hundred large check dams have been constructed during the last decades in ephemeral streams (Almeria). 36 of them have been investigated in selected Sierras. The volume of sediment retained was found low (mean: 1.4 t ha-1 yr-1). 67% of the variability has been explained by topographical, land use and agricultural activities. After a field survey in 2009, a large majority of check dams located in non-agricultural catchments have been found only partially filled with sediments. Extensive reforestation programs, recovery of natural vegetation (dense matorral) and abandonment of agricultural fields in the Sierras led to a strong reduction of the sediment transport towards the river system. Although the effect of the check dams on the transport of sediment has not been important, the check dams have played a major role in flood control in the area. Our data indicate that thoughtful design of SWC schemes is necessary to reconcile water harvesting, erosion mitigation and flood control. Currently, the erosion hotspots are clearly localized in the agricultural fields, and not in the marginal lands in the Sierras. The combination of on-site and off-site SWC measures in the agricultural areas is highly efficient to reduce fluxes of sediment and surface water.

Distinct oxygen hole doping in different layers of Sr₂CuO 4-δ/La₂CuO₄ superlattices

DOE PAGES

Smadici, S.; Lee, J. C. T.; Rusydi, A.; ...

2012-03-28

X-ray absorption in Sr₂CuO 4-δ/La₂CuO₄ (SCO/LCO) superlattices shows a variable occupation with doping of a hole state different from holes doped for x≲x optimal in bulk La 2-xSr xCuO₄ and suggests that this hole state is on apical oxygen atoms and polarized in the a-b plane. Considering the surface reflectivity gives a good qualitative description of the line shapes of resonant soft x-ray scattering. The interference between superlattice and surface reflections was used to distinguish between scatterers in the SCO and the LCO layers, with the two hole states maximized in different layers of the superlattice.

Sonocatalytic degradation of malachite green oxalate by a semiconductor metal oxide nanocatalyst.

PubMed

Bhavani, R; Sivasamy, A

2016-12-01

Advanced Oxidation Process (AOP) technologies are considered to be better technique for the degradation or mineralization of many recalcitrant compounds and pollutants. In the present study heterogeneous sonocatalytic degradation of a model organic compound such as Malachite green oxalate (MGO) was carried out in the aqueous phase. Zinc oxide nanorods were prepared by precipitation method employing zinc acetates as precursors and were characterized by FT-IR, XRD, FE-SEM and EDAX analysis. Degradation of MGO in the aqueous phase was studied in detail under the sonocatalytic process. Effects of pH, dye concentration, oxidant concentration, kinetics and effect of electrolytes on dye degradation were carried out to check the efficiency of the sonocatalyst. Effect of energy input on the degradation processes was also investigated. The degradation of dye molecules were monitored by UV-visible spectrophotometer and Chemical Oxygen demand (COD). The dye molecules were readily degraded at above 90% in the pH range 5.0-7.0 under ultrasound with zinc oxide nanorods. The interference of electrolytes like NaCl, KCl, Na 2 CO 3 , NaHCO 3 and MgSO 4 on the degradation of dye molecules were also studied on the sonocatalytic degradation of MGO. From the kinetic studies it was observed that at lower initial concentration of dye molecules the degradation efficiency was above 90%. The rate of the reaction decreased on increasing the initial dye concentrations of the dye molecules. It was observed that the complete mineralization of dye molecules was achieved without the formation of toxic by-products. The reusability of the catalyst also showed the effective degradation of the dye molecules up to five cycles without loss of the catalytic activities. Copyright © 2015 Elsevier Inc. All rights reserved.

A storage gas tank is moved to a pallet in the O&C

NASA Technical Reports Server (NTRS)

2001-01-01

KENNEDY SPACE CENTER, Fla. -- In the Operations and Checkout Building, workers check out the placement of one of four gas tanks on the Spacelab Logistics Double Pallet. Part of the STS- 104 payload, the storage tanks two gaseous oxygen and two gaseous nitrogen -- comprise the high pressure gas assembly that will be attached to the Joint Airlock Module during two spacewalks. The tanks will support future spacewalk operations from the Station and augment the Service Module gas resupply system.

Data services providing by the Ukrainian NODC (MHI NASU)

NASA Astrophysics Data System (ADS)

Eremeev, V.; Godin, E.; Khaliulin, A.; Ingerov, A.; Zhuk, E.

2009-04-01

At modern stage of the World Ocean study information support of investigation based on ad-vanced computer technologies becomes of particular importance. These abstracts are devoted to presentation of several data services developed in the Ukrainian NODC on the base of the Ma-rine Environmental and Information Technologies Department of MHI NASU. The Data Quality Control Service Using experience of international collaboration in the field of data collection and quality check we have developed the quality control (QC) software providing both preliminary(automatic) and expert(manual) data quality check procedures. The current version of the QC software works for the Mediterranean and Black seas and includes the climatic arrays for hydrological and few hydrochemical parameters based on such products as MEDAR/MEDATLAS II, Physical Oceanography of the Black Sea and Climatic Atlas of Oxygen and Hydrogen Sulfide in the Black sea. The data quality check procedure includes metadata control and hydrological and hydrochemical data control. Metadata control provides checking of duplicate cruises and pro-files, date and chronology, ship velocity, station location, sea depth and observation depth. Data QC procedure includes climatic (or range for parameters with small number of observations) data QC, density inversion check for hydrological data and searching for spikes. Using of cli-matic fields and profiles prepared by regional oceanography experts leads to more reliable results of data quality check procedure. The Data Access Services The Ukrainian NODC provides two products for data access - on-line software and data access module for the MHI NASU local net. This software allows select-ing data on rectangle area, on date, on months, on cruises. The result of query is metadata which are presented in the table and the visual presentation of stations on the map. It is possible to see both metadata and data. For this purpose it is necessary to select station in the table of metadata or on the map. There is also an opportunity to export data in ODV format. The product is avail-able on http://www.ocean.nodc.org.ua/DataAccess.php The local net version provides access to the oceanological database of the MHI NASU. The cur-rent version allows selecting data by spatial and temporal limits, depth, values of parameters, quality flags and works for the Mediterranean and Black seas. It provides visualization of meta-data and data, statistics of data selection, data export into several data formats. The Operational Data Management Services The collaborators of the MHI Experimental Branch developed a system of obtaining information on water pressure and temperature, as well as on atmospheric pressure. Sea level observations are also conducted. The obtained data are transferred online. The interface for operation data access was developed. It allows to select parameters (sea level, water temperature, atmospheric pressure, wind and wa-ter pressure) and time interval to see parameter graphics. The product is available on http://www.ocean.nodc.org.ua/Katsively.php . The Climatic products The current version of the Climatic Atlas includes maps on such pa-rameters as temperature, salinity, density, heat storage, dynamic heights, upper boundary of hy-drogen sulfide and lower boundary of oxygen for the Black sea basin. Maps for temperature, sa-linity, density were calculated on 19 standard depths and averaged monthly for depths 0 - 300 m and annually for lower depth values. The climatic maps of upper boundary of hydrogen sulfide and lower boundary of oxygen were averaged by decades from 20 till 90 of the XX century and by seasons. Two versions of climatic atlas viewer - on-line and desktop for presentation of the climatic maps were developed. They provide similar functions of selection and viewing maps by parameter, month and depth and saving maps in various formats. On-line version of atlas is available on http://www.ocean.nodc.org.ua/Main_Atlas.php .

A Novel Anti-Pollution Filter for Volatile Agents During Cardiopulmonary Bypass: Preliminary Tests.

PubMed

Nigro Neto, Caetano; Landoni, Giovanni; Tardelli, Maria Angela

2017-08-01

Concerns regarding pollution of the operating room by volatile anesthetics and effects on atmospheric ozone depletion exist. Volatile agents commonly are used during cardiopulmonary bypass to provide anesthesia independent of any supposed myocardial protective effects. The authors' aim was to create and to assess the performance of a prototype filter for volatile agents to be connected to the cardiopulmonary bypass circuit to avoid the emission of volatile agents to the operating room, and also to the environment without causing damage to the membrane oxygenator. Observational trial. University hospital. Prototype filter for volatile agents. The prototype filter was tested in a single ex vivo experiment. The main data measured during the test were pressure drop to detect interference with the performance of the oxygenator, back pressure to detect overpressure to the outlet gas jacket of the oxygenator, analysis of exhaled sevoflurane after the membrane oxygenator, and after the filter to detect any presence of sevoflurane. The prototype filter adsorbed the sevoflurane eliminated through the outlet portion of the oxygenator. During the entire test, the back pressure remained constant (4 mmHg) and pressure drop varied from 243 mmHg to 247 mmHg. The prototype filter was considered suitable to absorb the sevoflurane, and it did not cause an overpressure to the membrane oxygenator during the test. Copyright © 2017 Elsevier Inc. All rights reserved.

Electrode Reactions Coupled with Chemical Reactions of Oxygen, Water and Acetaldehyde in an Ionic Liquid: New Approaches for Sensing Volatile Organic Compounds.

PubMed

Chi, Xiaowei; Tang, Yongan; Zeng, Xiangqun

2016-10-20

Water and oxygen are ubiquitous present in ambient conditions. This work studies the unique oxygen, trace water and a volatile organic compound (VOC) acetaldehyde redox chemistry in a hydrophobic and aprotic ionic liquid (IL), 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide ([Bmpy] [NTf 2 ]) by cyclic voltammetry and potential step methods. One electron oxygen reduction leads to superoxide radical formation in the IL. Trace water in the IL acts as a protic species that reacts with the superoxide radical. Acetaldehyde is a stronger protic species than water for reacting with the superoxide radical. The presence of trace water in the IL was also demonstrated to facilitate the electro-oxidation of acetaldehyde, with similar mechanism to that in the aqueous solutions. A multiple-step coupling reaction mechanism between water, superoxide radical and acetaldehyde has been described. The unique characteristics of redox chemistry of acetaldehyde in [Bmpy][NTf 2 ] in the presence of oxygen and trace water can be controlled by electrochemical potentials. By controlling the electrode potential windows, several methods including cyclic voltammetry, potential step methods (single-potential, double-potential and triple-potential step methods) were established for the quantification of acetaldehyde. Instead of treating water and oxygen as frustrating interferents to ILs, we found that oxygen and trace water chemistry in [Bmpy][NTf 2 ] can be utilized to develop innovative electrochemical methods for electroanalysis of acetaldehyde.

Electrode Reactions Coupled with Chemical Reactions of Oxygen, Water and Acetaldehyde in an Ionic Liquid: New Approaches for Sensing Volatile Organic Compounds

PubMed Central

Chi, Xiaowei; Tang, Yongan; Zeng, Xiangqun

2017-01-01

Water and oxygen are ubiquitous present in ambient conditions. This work studies the unique oxygen, trace water and a volatile organic compound (VOC) acetaldehyde redox chemistry in a hydrophobic and aprotic ionic liquid (IL), 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide ([Bmpy] [NTf2]) by cyclic voltammetry and potential step methods. One electron oxygen reduction leads to superoxide radical formation in the IL. Trace water in the IL acts as a protic species that reacts with the superoxide radical. Acetaldehyde is a stronger protic species than water for reacting with the superoxide radical. The presence of trace water in the IL was also demonstrated to facilitate the electro-oxidation of acetaldehyde, with similar mechanism to that in the aqueous solutions. A multiple-step coupling reaction mechanism between water, superoxide radical and acetaldehyde has been described. The unique characteristics of redox chemistry of acetaldehyde in [Bmpy][NTf2] in the presence of oxygen and trace water can be controlled by electrochemical potentials. By controlling the electrode potential windows, several methods including cyclic voltammetry, potential step methods (single-potential, double-potential and triple-potential step methods) were established for the quantification of acetaldehyde. Instead of treating water and oxygen as frustrating interferents to ILs, we found that oxygen and trace water chemistry in [Bmpy][NTf2] can be utilized to develop innovative electrochemical methods for electroanalysis of acetaldehyde. PMID:29142331

Influence of cutaneous and muscular circulation on spatially resolved versus standard Beer-Lambert near-infrared spectroscopy.

PubMed

Messere, Alessandro; Roatta, Silvestro

2013-12-01

The potential interference of cutaneous circulation on muscle blood volume and oxygenation monitoring by near-infrared spectroscopy (NIRS) remains an important limitation of this technique. Spatially resolved spectroscopy (SRS) was reported to minimize the contribution of superficial tissue layers in cerebral monitoring but this characteristic has never been documented in muscle tissue monitoring. This study aims to compare SRS with the standard Beer-Lambert (BL) technique in detecting blood volume changes selectively induced in muscle and skin. In 16 healthy subjects, the biceps brachii was investigated during isometric elbow flexion at 70% of the maximum voluntary contractions lasting 10 sec, performed before and after exposure of the upper arm to warm air flow. From probes applied over the muscle belly the following variables were recorded: total hemoglobin index (THI, SRS-based), total hemoglobin concentration (tHb, BL-based), tissue oxygenation index (TOI, SRS-based), and skin blood flow (SBF), using laser Doppler flowmetry. Blood volume indices exhibited similar changes during muscle contraction but only tHb significantly increased during warming (+5.2 ± 0.7 μmol/L·cm, an effect comparable to the increase occurring in postcontraction hyperemia), accompanying a 10-fold increase in SBF. Contraction-induced changes in tHb and THI were not substantially affected by warming, although the tHb tracing was shifted upward by (5.2 ± 3.5 μmol/L·cm, P < 0.01). TOI was not affected by cutaneous warming. In conclusion, SRS appears to effectively reject interference by SBF in both muscle blood volume and oxygenation monitoring. Instead, BL-based parameters should be interpreted with caution, whenever changes in cutaneous perfusion cannot be excluded.

Influence of cutaneous and muscular circulation on spatially resolved versus standard Beer–Lambert near‐infrared spectroscopy

PubMed Central

Messere, Alessandro; Roatta, Silvestro

2013-01-01

Abstract The potential interference of cutaneous circulation on muscle blood volume and oxygenation monitoring by near‐infrared spectroscopy (NIRS) remains an important limitation of this technique. Spatially resolved spectroscopy (SRS) was reported to minimize the contribution of superficial tissue layers in cerebral monitoring but this characteristic has never been documented in muscle tissue monitoring. This study aims to compare SRS with the standard Beer–Lambert (BL) technique in detecting blood volume changes selectively induced in muscle and skin. In 16 healthy subjects, the biceps brachii was investigated during isometric elbow flexion at 70% of the maximum voluntary contractions lasting 10 sec, performed before and after exposure of the upper arm to warm air flow. From probes applied over the muscle belly the following variables were recorded: total hemoglobin index (THI, SRS‐based), total hemoglobin concentration (tHb, BL‐based), tissue oxygenation index (TOI, SRS‐based), and skin blood flow (SBF), using laser Doppler flowmetry. Blood volume indices exhibited similar changes during muscle contraction but only tHb significantly increased during warming (+5.2 ± 0.7 μmol/L·cm, an effect comparable to the increase occurring in postcontraction hyperemia), accompanying a 10‐fold increase in SBF. Contraction‐induced changes in tHb and THI were not substantially affected by warming, although the tHb tracing was shifted upward by (5.2 ± 3.5 μmol/L·cm, P < 0.01). TOI was not affected by cutaneous warming. In conclusion, SRS appears to effectively reject interference by SBF in both muscle blood volume and oxygenation monitoring. Instead, BL‐based parameters should be interpreted with caution, whenever changes in cutaneous perfusion cannot be excluded. PMID:24744858

Liquid-chromatographic determination of cephalosporins and chloramphenicol in serum.

PubMed

Danzer, L A

1983-05-01

A "high-performance" liquid-chromatographic technique involving a radial compression module is used for measuring chloramphenicol and five cephalosporin antibiotics: cefotaxime, cefoxitin, cephapirin, and cefamandol. Serum proteins are precipitated with acetonitrile solution containing 4'-nitroacetanilide as the internal standard. The drugs are eluted with a mobile phase of methanol/acetate buffer (30/70 by vol), pH 5.5. Absorbance of the cephalosporins is monitored at 254 nm. Standard curves are linear to at least 100 mg/L. The absorbance of chloramphenicol is monitored at 254 nm and 280 nm, and its standard curve is linear to at least 50 mg/L. The elution times for various other drugs were also determined, to check for potential interferents.

Korea Geodetic VLBI Station, Sejong

NASA Technical Reports Server (NTRS)

Donghyun, Baek; Sangoh, Yi; Hongjong, Oh; Sangchul, Han

2013-01-01

The Sejong VLBI station officially joined the IVS as a new Network Station in 2012. This report summarizes the activities of the Sejong station during 2012. The following are the activities at the station: 1) VLBI test observations were carried out with the Tsukuba 34-m antenna of the GSI in Japan. As a result, the Sejong antenna needs to improve its efficiency, which is currently in progress, 2) A survey to connect the VLBI reference point to GNSS and ground marks was conducted, and 3) To see the indirect effects of RFI (Radio Frequency Interference) at this place, we checked the omni-direction (AZ 0? to 360?, EL fixed at 7?) for RFI influence.

Measurement of the oxygen isotopic composition of nitrate in seawater and freshwater using the denitrifier method

USGS Publications Warehouse

Casciotti, K.L.; Sigman, D.M.; Hastings, M. Galanter; Böhlke, J.K.; Hilkert, A.

2002-01-01

We report a novel method for measurement of the oxygen isotopic composition (18O/16O) of nitrate (NO3-) from both seawater and freshwater. The denitrifier method, based on the isotope ratio analysis of nitrous oxide generated from sample nitrate by cultured denitrifying bacteria, has been described elsewhere for its use in nitrogen isotope ratio (15N/14N) analysis of nitrate.1Here, we address the additional issues associated with 18O/16O analysis of nitrate by this approach, which include (1) the oxygen isotopic difference between the nitrate sample and the N2O analyte due to isotopic fractionation associated with the loss of oxygen atoms from nitrate and (2) the exchange of oxygen atoms with water during the conversion of nitrate to N2O. Experiments with 18O-labeled water indicate that water exchange contributes less than 10%, and frequently less than 3%, of the oxygen atoms in the N2O product for Pseudomonas aureofaciens. In addition, both oxygen isotope fractionation and oxygen atom exchange are consistent within a given batch of analyses. The analysis of appropriate isotopic reference materials can thus be used to correct the measured 18O/16O ratios of samples for both effects. This is the first method tested for 18O/16O analysis of nitrate in seawater. Benefits of this method, relative to published freshwater methods, include higher sensitivity (tested down to 10 nmol and 1 μM NO3-), lack of interference by other solutes, and ease of sample preparation.

Surface characterization of tin-based inorganic EUV resists

NASA Astrophysics Data System (ADS)

Frederick, Ryan T.; Diulus, J. Trey; Lyubinetsky, Igor; Hutchison, Danielle C.; Olsen, Morgan R.; Nyman, May; Herman, Gregory S.

2018-03-01

Metal oxide nanomaterials have shown promise for use as EUV resists. Recently, significant efforts have focused on tinoxo clusters that have high absorption coefficient Sn centers and radiation sensitive organic ligands. In our studies, we have investigated a β-Keggin butyl-Sn cluster (β-NaSn13), which is charge-neutral and allows studying radiation induced chemistries without interference from counterions. We have used ambient pressure X-ray photoelectron spectroscopy (APXPS) to investigate the contrast properties of the β-NaSn13 in ultrahigh vacuum (UHV) and in the presence of ambient oxygen. These contrast studies indicate that ambient oxygen reduces the dose requirements for the solubility transition of the β-NaSn13 photoresists. APXPS spectra collected before and after the solubility transition shows that ambient oxygen causes a greater loss of butyl ligands from the samples and the formation of more tin oxide for larger doses, suggesting the presence of reactive oxygen species. APXPS was also used to study processes during the post exposure bake, where we compared the differences in film chemistries in ambient oxygen or in UHV. There were only very small differences in the APXPS spectra before exposure and after exposure and the post exposure bake. However, ambient oxygen resulted in some changes for unexposed regions during the post exposure bake; there was a greater ratio of tin oxide to other oxygen species (alkoxy ligands, hydroxyls) for samples annealed in oxygen. These results have significance for EUV and e-beam lithography processing parameters, as well as implications for cluster design and ligand chemistries.

Reduction of interferences in graphite furnace atomic absorption spectrometry by multiple linear regression modelling

NASA Astrophysics Data System (ADS)

Grotti, Marco; Abelmoschi, Maria Luisa; Soggia, Francesco; Tiberiade, Christian; Frache, Roberto

2000-12-01

The multivariate effects of Na, K, Mg and Ca as nitrates on the electrothermal atomisation of manganese, cadmium and iron were studied by multiple linear regression modelling. Since the models proved to efficiently predict the effects of the considered matrix elements in a wide range of concentrations, they were applied to correct the interferences occurring in the determination of trace elements in seawater after pre-concentration of the analytes. In order to obtain a statistically significant number of samples, a large volume of the certified seawater reference materials CASS-3 and NASS-3 was treated with Chelex-100 resin; then, the chelating resin was separated from the solution, divided into several sub-samples, each of them was eluted with nitric acid and analysed by electrothermal atomic absorption spectrometry (for trace element determinations) and inductively coupled plasma optical emission spectrometry (for matrix element determinations). To minimise any other systematic error besides that due to matrix effects, accuracy of the pre-concentration step and contamination levels of the procedure were checked by inductively coupled plasma mass spectrometric measurements. Analytical results obtained by applying the multiple linear regression models were compared with those obtained with other calibration methods, such as external calibration using acid-based standards, external calibration using matrix-matched standards and the analyte addition technique. Empirical models proved to efficiently reduce interferences occurring in the analysis of real samples, allowing an improvement of accuracy better than for other calibration methods.

Quantitative phase imaging of platelet: assessment of cell morphology and function

NASA Astrophysics Data System (ADS)

Vasilenko, Irina; Vlasova, Elizaveta; Metelin, Vladislav; Agadzhanjan, B.; Lyfenko, R.

2017-02-01

It is well known that platelets play a central role in hemostasis and thrombosis, they also mediate tumor cell growth, dissemination and angiogenesis. The purpose of the present experiment was to evaluate living platelet size, function and morphology simultaneously in unactivated and activated states using Phase-Interference Microscope "Cytoscan" (Moscow, Russia). We enrolled 30 healthy volunteers, who had no past history of aeteriosclerosis-related disorders, such as coronary heart disease, cerebrovascular disease, hypertention, diabetes or hyperlipidemia and 30 patients with oropharynx cancer. We observed the optic-geometrical parameters of each isolated living cell and the distribution of platelets by sizes have been analysed to detect the dynamics of cell population heterogeneity. Simultaneously we identified 4 platelet forms that have different morphological features and different parameters of size distribution. We noticed that morphological platelet types correlate with morphometric platelet parameters. The data of polymorphisms of platelet reactivity in tumor progression can be used to improve patient outcomes in the cancer prevention and treatment. Moreover morphometric and functional platelet parameters can serve criteria of the efficiency of the radio- and chemotherapy carried out. In conclusion the computer phase-interference microscope provides rapid and effective analysis of living platelet morphology and function at the same time. The use of the computer phase-interference microscope could be an easy and fast method to check the state of platelets in patients with changed platelet activation and to follow a possible pharmacological therapy to reduce this phenomenon.

Elephant Trunk-Like Teratoma of the Face with Compromised Airway in an Infant with Complex Congenital Cardiac Defects: An Anesthetic Challenge.

PubMed

Maddali, Madan Mohan; Al Balushi, Faisal Khalfan Ahmed; Waje, Niranjan Dilip

2016-02-01

Large head and neck teratomas are very rare. Depending on their site of origin, they can produce varying degrees of airway compromise and can interfere with the conduct of general anesthesia. Large space-occupying lesions of the face may even interfere with the simple task of mask ventilation rendering inhaled induction of general anesthesia and maintenance of spontaneous ventilation difficult. If these neoplasms coexist with cardiac lesions necessitating corrective or palliative procedures, the task of oxygenation, ventilation, and securing a definitive airway becomes challenging especially in the presence of underlying unstable hemodynamics. We report on the anesthetic management of a female infant with a facial teratoma and single-ventricle physiology undergoing a cardiac palliative procedure where securing a definitive airway with minimal hemodynamic instability was the immediate requirement.

Dataset reporting BCKDK interference in a BCAA-catabolism restricted environment.

PubMed

Bravo-Alonso, I; Oyarzabal, A; Sánchez-Aragó, M; Rejas, M T; Merinero, B; García-Cazorla, A; Artuch, R; Ugarte, M; Rodríguez-Pombo, P

2016-06-01

This data article contains complementary figures to the research article "Mitochondrial response to the BCKDK-deficiency: some clues to understand the positive dietary response in this form of autism" [1]. Herein we present data relative to the effect of knocking down BCKDK gene on the real time oxygen consumption rate of fibroblasts obtained from a Maple Syrup Urine Disease (MSUD) patient. Interference of BCKDK expression on such cells showing a reduced branched-chain α-ketoacid dehydrogenase (BCKDHc) activity; let us generate a scenario to study the direct effect of BCKDK absence in an environment of high branched-chain amino acids (BCAAs) concentrations. Data relative to the effectiveness of the knockdown together with the potentiality of the BCKDK-knockdown to increase the deficient branched-chain α-ketoacid dehydrogenase activity detected in MSUD patients are also shown.

Possible role of interference, protein noise, and sink effects in nonphotochemical quenching in photosynthetic complexes.

PubMed

Berman, Gennady P; Nesterov, Alexander I; Gurvitz, Shmuel; Sayre, Richard T

2017-01-01

We analyze theoretically a simple and consistent quantum mechanical model that reveals the possible role of quantum interference, protein noise, and sink effects in the nonphotochemical quenching (NPQ) in light-harvesting complexes (LHCs). The model consists of a network of five interconnected sites (excitonic states of light-sensitive molecules) responsible for the NPQ mechanism. The model also includes the "damaging" and the dissipative channels. The damaging channel is responsible for production of singlet oxygen and other destructive outcomes. In our model, both damaging and "dissipative" charge transfer channels are described by discrete electron energy levels attached to their sinks, that mimic the continuum part of electron energy spectrum. All five excitonic sites interact with the protein environment that is modeled using a stochastic process. Our approach allowed us to derive the exact and closed system of linear ordinary differential equations for the reduced density matrix and its first momentums. These equations are solved numerically including for strong interactions between the light-sensitive molecules and protein environment. As an example, we apply our model to demonstrate possible contributions of quantum interference, protein noise, and sink effects in the NPQ mechanism in the CP29 minor LHC. The numerical simulations show that using proper combination of quantum interference effects, properties of noise, and sinks, one can significantly suppress the damaging channel. Our findings demonstrate the possible role of interference, protein noise, and sink effects for modeling, engineering, and optimizing the performance of the NPQ processes in both natural and artificial light-harvesting complexes.

Possible role of interference, protein noise, and sink effects in nonphotochemical quenching in photosynthetic complexes

DOE PAGES

Berman, Gennady P.; Nesterov, Alexander I.; Gurvitz, Shmuel; ...

2016-04-30

Here, we analyze theoretically a simple and consistent quantum mechanical model that reveals the possible role of quantum interference, protein noise, and sink effects in the nonphotochemical quenching (NPQ) in light-harvesting complexes (LHCs). The model consists of a network of five interconnected sites (excitonic states of light-sensitive molecules) responsible for the NPQ mechanism. The model also includes the “damaging” and the dissipative channels. The damaging channel is responsible for production of singlet oxygen and other destructive outcomes. In this model, both damaging and “dissipative” charge transfer channels are described by discrete electron energy levels attached to their sinks, that mimicmore » the continuum part of electron energy spectrum. All five excitonic sites interact with the protein environment that is modeled using a stochastic process. Our approach allowed us to derive the exact and closed system of linear ordinary differential equations for the reduced density matrix and its first momentums. Moreover, these equations are solved numerically including for strong interactions between the light-sensitive molecules and protein environment. As an example, we apply our model to demonstrate possible contributions of quantum interference, protein noise, and sink effects in the NPQ mechanism in the CP29 minor LHC. The numerical simulations show that using proper combination of quantum interference effects, properties of noise, and sinks, one can significantly suppress the damaging channel. Finally, our findings demonstrate the possible role of interference, protein noise, and sink effects for modeling, engineering, and optimizing the performance of the NPQ processes in both natural and artificial light-harvesting complexes.« less

Use of pulse oximeter placed on a gastroschisis silo to monitor intestinal oxygen saturation.

PubMed

Kim, Sunghoon; Betts, James; Yedlin, Steve; Rowe, Richard; Idowu, Olajire

2006-09-01

The use of a silo for temporary coverage of exposed viscera for newborns with gastroschisis has allowed gradual reduction of the externalized intestine into the abdominal cavity. However, there has not been an easy way to monitor blood perfusion to the intestine within the silo other than with visual examination. In addition, visual examination of bowel through the silo is sometimes difficult for medical staff due to serositis and peel over the bowel. We have adopted an approach to monitor oxygen saturation of silo-contained intestine by placing a pulse oximeter sensor on the surface of the transparent silo to detect intestinal ischemia. Pulse oximeter sensors were applied on both a patient's distal extremity and the silo on five consecutive patients who were born with gastroschisis. The sensor was left on the silo during the entire period of gradual reduction. Perfusion index, pulse and oxygen saturation were observed and checked against the sensor placed on a peripheral extremity. The silo-placed pulse oximeter and peripheral pulse oximeter sensors showed a similar pulse and oxygen saturation throughout the reduction period in all five patients. In general, perfusion index was higher from the silo pulse oximeter compared to the peripheral pulse oximeter reading. A pulse oximeter can be used to monitor intestinal oxygen saturation contained within a silo and help modulate the rate of manual reduction of intestine.

Cavity transport effects in generator-collector electrochemical analysis of nitrobenzene.

PubMed

Lewis, Grace E M; Dale, Sara E C; Kasprzyk-Hordern, Barbara; Lubben, Anneke T; Barnes, Edward O; Compton, Richard G; Marken, Frank

2014-09-21

Two types of generator-collector electrode systems, (i) a gold-gold interdigitated microband array and (ii) a gold-gold dual-plate microtrench, are compared for nitrobenzene electroanalysis in aerated aqueous 0.1 M NaOH. The complexity of the nitrobenzene reduction in conjunction with the presence of ambient levels of oxygen in the analysis solution provide a challenging problem in which feedback-amplified generator-collector steady state currents provide the analytical signal. In contrast to the more openly accessible geometry of the interdigitated array electrode, where the voltammetric response for nitrobenzene is less well-defined and signals drift, the voltammetric response for the cavity-like microtrench electrode is stable and readily detectable at 1 μM level. Both types of electrode show oxygen-enhanced low concentration collector current responses due to additional feedback via reaction intermediates. The observations are rationalised in terms of a "cavity transport coefficient" which is beneficial in the dual-plate microtrench, where oxygen interference effects are suppressed and the analytical signal is amplified and stabilised.

Clinical system for non-invasive in situ monitoring of gases in the human paranasal sinuses.

PubMed

Lewander, Märta; Guan, Zuguang; Svanberg, Katarina; Svanberg, Sune; Svensson, Tomas

2009-06-22

We present a portable system for non-invasive, simultaneous sensing of molecular oxygen (O(2)) and water vapor (H(2)O) in the human paranasal cavities. The system is based on high-resolution tunable diode laser spectroscopy (TDLAS) and digital wavelength modulation spectroscopy (dWMS). Since optical interference and non-ideal tuning of the diode lasers render signal processing complex, we focus on Fourier analysis of dWMS signals and procedures for removal of background signals. Clinical data are presented, and exhibit a significant improvement in signal-to-noise with respect to earlier work. The in situ detection limit, in terms of absorption fraction, is about 5x10(-5) for oxygen and 5x10(-4) for water vapor, but varies between patients due to differences in light attenuation. In addition, we discuss the use of water vapor as a reference in quantification of in situ oxygen concentration in detail. In particular, light propagation aspects are investigated by employing photon time-of-flight spectroscopy.

A New Approach for On-Demand Generation of Various Oxygen Tensions for In Vitro Hypoxia Models

PubMed Central

Li, Chunyan; Chaung, Wayne; Mozayan, Cameron; Chabra, Ranjeev; Wang, Ping; Narayan, Raj K.

2016-01-01

The development of in vitro disease models closely mimicking the functions of human disease has captured increasing attention in recent years. Oxygen tensions and gradients play essential roles in modulating biological systems in both physiologic and pathologic events. Thus, controlling oxygen tension is critical for mimicking physiologically relevant in vivo environments for cell, tissue and organ research. We present a new approach for on-demand generation of various oxygen tensions for in vitro hypoxia models. Proof-of-concept prototypes have been developed for conventional cell culture microplate by immobilizing a novel oxygen-consuming biomaterial on the 3D-printed insert. For the first time, rapid (~3.8 minutes to reach 0.5% O2 from 20.9% O2) and precisely controlled oxygen tensions/gradients (2.68 mmHg per 50 μm distance) were generated by exposing the biocompatible biomaterial to the different depth of cell culture media. In addition, changing the position of 3D-printed inserts with immobilized biomaterials relative to the cultured cells resulted in controllable and rapid changes in oxygen tensions (<130 seconds). Compared to the current technologies, our approach allows enhanced spatiotemporal resolution and accuracy of the oxygen tensions. Additionally, it does not interfere with the testing environment while maintaining ease of use. The elegance of oxygen tension manipulation introduced by our new approach will drastically improve control and lower the technological barrier of entry for hypoxia studies. Since the biomaterials can be immobilized in any devices, including microfluidic devices and 3D-printed tissues or organs, it will serve as the basis for a new generation of experimental models previously impossible or very difficult to implement. PMID:27219067

A New Approach for On-Demand Generation of Various Oxygen Tensions for In Vitro Hypoxia Models.

PubMed

Li, Chunyan; Chaung, Wayne; Mozayan, Cameron; Chabra, Ranjeev; Wang, Ping; Narayan, Raj K

2016-01-01

The development of in vitro disease models closely mimicking the functions of human disease has captured increasing attention in recent years. Oxygen tensions and gradients play essential roles in modulating biological systems in both physiologic and pathologic events. Thus, controlling oxygen tension is critical for mimicking physiologically relevant in vivo environments for cell, tissue and organ research. We present a new approach for on-demand generation of various oxygen tensions for in vitro hypoxia models. Proof-of-concept prototypes have been developed for conventional cell culture microplate by immobilizing a novel oxygen-consuming biomaterial on the 3D-printed insert. For the first time, rapid (~3.8 minutes to reach 0.5% O2 from 20.9% O2) and precisely controlled oxygen tensions/gradients (2.68 mmHg per 50 μm distance) were generated by exposing the biocompatible biomaterial to the different depth of cell culture media. In addition, changing the position of 3D-printed inserts with immobilized biomaterials relative to the cultured cells resulted in controllable and rapid changes in oxygen tensions (<130 seconds). Compared to the current technologies, our approach allows enhanced spatiotemporal resolution and accuracy of the oxygen tensions. Additionally, it does not interfere with the testing environment while maintaining ease of use. The elegance of oxygen tension manipulation introduced by our new approach will drastically improve control and lower the technological barrier of entry for hypoxia studies. Since the biomaterials can be immobilized in any devices, including microfluidic devices and 3D-printed tissues or organs, it will serve as the basis for a new generation of experimental models previously impossible or very difficult to implement.

Novel Semi-Parametric Algorithm for Interference-Immune Tunable Absorption Spectroscopy Gas Sensing

PubMed Central

Michelucci, Umberto; Venturini, Francesca

2017-01-01

One of the most common limits to gas sensor performance is the presence of unwanted interference fringes arising, for example, from multiple reflections between surfaces in the optical path. Additionally, since the amplitude and the frequency of these interferences depend on the distance and alignment of the optical elements, they are affected by temperature changes and mechanical disturbances, giving rise to a drift of the signal. In this work, we present a novel semi-parametric algorithm that allows the extraction of a signal, like the spectroscopic absorption line of a gas molecule, from a background containing arbitrary disturbances, without having to make any assumption on the functional form of these disturbances. The algorithm is applied first to simulated data and then to oxygen absorption measurements in the presence of strong fringes.To the best of the authors’ knowledge, the algorithm enables an unprecedented accuracy particularly if the fringes have a free spectral range and amplitude comparable to those of the signal to be detected. The described method presents the advantage of being based purely on post processing, and to be of extremely straightforward implementation if the functional form of the Fourier transform of the signal is known. Therefore, it has the potential to enable interference-immune absorption spectroscopy. Finally, its relevance goes beyond absorption spectroscopy for gas sensing, since it can be applied to any kind of spectroscopic data. PMID:28991161

Sex-specific neural activity when resolving cognitive interference in individuals with or without prior internalizing disorders.

PubMed

Wang, Zhishun; Jacobs, Rachel H; Marsh, Rachel; Horga, Guillermo; Qiao, Jianping; Warner, Virginia; Weissman, Myrna M; Peterson, Bradley S

2016-03-30

The processing of cognitive interference is a self-regulatory capacity that is impaired in persons with internalizing disorders. This investigation was to assess sex differences in the neural correlates of cognitive interference in individuals with and without an illness history of an internalizing disorder. We compared functional magnetic resonance imaging blood-oxygenation-level-dependent responses in both males (n=63) and females (n=80) with and without this illness history during performance of the Simon task. Females deactivated superior frontal gyrus, inferior parietal lobe, and posterior cingulate cortex to a greater extent than males. Females with a prior history of internalizing disorder also deactivated these regions more compared to males with that history, and they additionally demonstrated greater activation of right inferior frontal gyrus. These group differences were represented in a significant sex-by-illness interaction in these regions. These deactivated regions compose a task-negative or default mode network, whereas the inferior frontal gyrus usually activates when performing an attention-demanding task and is a key component of a task-positive network. Our findings suggest that a prior history of internalizing disorders disproportionately influences functioning of the default mode network and is associated with an accompanying activation of the task-positive network in females during the resolution of cognitive interference. Copyright © 2016. Published by Elsevier Ireland Ltd.

Automated assembling of single fuel cell units for use in a fuel cell stack

NASA Astrophysics Data System (ADS)

Jalba, C. K.; Muminovic, A.; Barz, C.; Nasui, V.

2017-05-01

The manufacturing of PEMFC stacks (POLYMER ELEKTROLYT MEMBRAN Fuel Cell) is nowadays still done by hand. Over hundreds of identical single components have to be placed accurate together for the construction of a fuel cell stack. Beside logistic problems, higher total costs and disadvantages in weight the high number of components produce a higher statistic interference because of faulty erection or material defects and summation of manufacturing tolerances. The saving of costs is about 20 - 25 %. Furthermore, the total weight of the fuel cells will be reduced because of a new sealing technology. Overall a one minute cycle time has to be aimed per cell at the manufacturing of these single components. The change of the existing sealing concept to a bonded sealing is one of the important requisites to get an automated manufacturing of single cell units. One of the important steps for an automated gluing process is the checking of the glue application by using of an image processing system. After bonding the single fuel cell the sealing and electrical function can be checked, so that only functional and high qualitative cells can get into further manufacturing processes.

A Comparative evaluation of Graphene oxide based materials for Electrochemical non-enzymatic sensing of Curcumin

NASA Astrophysics Data System (ADS)

Dey, Nibedita; Devasena, T.; Sivalingam, Tamilarasu

2018-02-01

This work reports a comparative study on the development of a sensitive voltammetric method for the assay of diferuloylmethane which is fabricated using cost-effective sensing material graphene oxide (GO modified electrode) and reduced graphene oxide (rGO modified electrode) modified on glassy carbon electrode respectively. The prepared materials were characterized using SEM, XRD, FTIR, and Raman techniques to understand the formation. Between the both modified electrodes, rGO modified electrode demonstrated a lower limit detection of 0.9 pM and good signal quality. But, the better linear dynamic range for detection was found to be 1 nm to 100 nM for GO and 0.1 nM to 10 nM for rGO modified electrodes respectively. The repeatability is checked for seven cycles and interference studies were also performed for checking the sensors’ selectivity to curcumin. rGO modified electrode and GO modified electrode both shows specific signals for Diferuloylmethane under conditions similar to physiology. But, with better properties over GO modified electrode, rGO modified electrode is suggested a better candidate for real-time usability in sensing. The detection limit reported is the lowest till date for the given plant drug using any sensing assay.

Indagation of serum and salivary reactive oxygen metabolite and cortisol levels in chronic periodontitis and stress-induced chronic periodontitis patients

PubMed Central

Sudhakar, Uma; Thyagarajan, Ramakrishnan; Jeyapal, Bhagyameena; Jagadeesh, Sushuruthi; Jayakumar, Parvathee

2017-01-01

Background: Periodontal disease is not a conventional bacterial infection but is an inflammatory disease initiated by immune response against a group of microorganisms in susceptible hosts. There are many intriguing researches that unfold the secrets of chronic periodontitis. The current researches in chronic periodontitis are directed toward an approach that respects the scientific relationship between the various risk factors, the genetic factors, and the progression of the disease. Aim: This study aims to evaluate the cortisol and reactive oxygen metabolites (ROM) concentration in serum and to find out their association in periodontal health and disease. Materials and Methods: In this study, totally thirty patients have been taken and divided into two groups of chronic periodontitis (Group I) and stress-induced chronic periodontitis (Group II) and evaluated the correlation between the ROM and cortisol levels in them. This is the first study, where both the levels of ROM and cortisol are checked in the serum and saliva. The analysis is done to check the association between them. Statistical Analysis: The data were statistically analyzed using software program (SPSSV 16), Pearson correlation, and paired t-test. Results: Comparison of the mean ROM levels in Group I and Group II showed that mean ROM level in Group II is highly significant than Group I. Conclusion: Our study suggests that stress can have a role in the progression of periodontal disease by increasing the cortisol and ROM levels. PMID:29491582

Aluminum work function: Effect of oxidation, mechanical scraping and ion bombardment

NASA Technical Reports Server (NTRS)

Vinet, P.; Lemogne, T.; Montes, H.

1985-01-01

Surface studies have been performed on aluminum polycrystalline surfaces which have been mechanically scraped. Such studies were initiated in order to understand surface effects occurring in tribological processes which involve rubbing surfaces and the effects of adsorption of oxygen. To characterize the surfaces, the following three different experimental approaches have been used: (1) X.P.S. (X-ray photoelectron spectroscopy), in order to check the cleanliness of the surfaces and follow the adsorption and oxidation kinetics; (2) Analysis of the work function changes by following the energy spectra of secondary electrons emitted under low energy electron bombardment; and (3) Analysis of photoemission intensities under U.V. excitation. The reference state being chosen to be the surface cleaned by ion bombardment and exposures to oxygen atmospheres have been shown to lower the work function of clean polycrystalline aluminum by 1.2 eV. The oxygen pressure is found to affect only the kinetics of these experiments. Mechanical scraping has been shown to induce a decrease ( 0.3 eV) in the work function, which could sharply modify the kinetics of adsorption on the surface.

Study of physio-psychological effects on traffic wardens due to traffic noise pollution; exposure-effect relation.

PubMed

Tabraiz, Shamas; Ahmad, Saeed; Shehzadi, Iffat; Asif, Muhammad Bilal

2015-01-01

Noise pollution has increased to alarming extent in most of the urban areas in Pakistan. It is assumed even more perilous than air and water pollution due to its direct acute and chronic physio-psychological effects. The objective of this study is to analyze and evaluate the psychological and physiological effects caused by traffic noise on traffic wardens and to find relation type between exposure time and effect. Three wardens check posts near roads were selected for survey in Taxila and Islamabad cities of Pakistan. Survey conducted included noise measurements at aforementioned check posts for one month and Performa based interviews of traffic wardens. Analysis of results showed that noise levels varied between 85-106 dB hence violating OSHA regulations. Major psychological effects found in wardens were aggravated depression 58%, stress 65%, public conflict 71%, irritation and annoyance 54%, behavioral affects 59% and speech interference 56%. Physiological effects found were hypertension 87%, muscle tension 64%, exhaustion 48%, low performance levels 55%, concentration loss 93%, hearing impairment 69%, headache 74% and cardiovascular issue 71%. Relation between exposure time and effects were evaluated by using simple regression test in excel. Percentage of psychological and physiological effects in wardens varied with the exposure time; aggravated depression (R(2) = 0.946, P = 0.133), stress suffering (R(2) = 0.014, P = 0.173), public conflict (R(2) = 0.946, P = 0.133), irritation and annoyance (R(2) = 0.371, P = 0.137), behavioral affects (R(2) = 0.596, P = 0.0616) and speech interference (R(2) = 0.355, P = 0.445), hypertension (R(2) = 0.96, P = 0.00095) and cardiovascular issue (R(2) = 0.775, P = 0.044).

Oxygen isotopic fractionation of O₂ during adsorption and desorption processes using molecular sieve at low temperatures.

PubMed

Ahn, Insu; Kusakabe, Minoru; Lee, Jong Ik

2014-06-15

Cryogenic trapping using molecular sieves is commonly used to collect O2 extracted from silicates for (17)O/(16)O and (18)O/(16)O analyses. However, gases which interfere with (17)O/(16)O analysis, notably NF3, are also trapped and their removal is essential for accurate direct measurement of the (17)O/(16)O ratio. It is also necessary to identify and quantify any isotopic fractionation associated with the use of cryogenic trapping using molecular sieves. The oxygen isotopic compositions of O2 before and after desorption from, and adsorption onto, 13X and 5A molecular sieves (MS13X and MS5A) at 0°C, -78°C, -114°C, and -130°C were measured in order to determine the oxygen isotopic fractionation at these temperatures. We also investigated whether isotopic fractionation occurred when O2 gas was transferred sequentially into a second cold finger, also containing molecular sieve. It was confirmed that significant oxygen isotopic fractionation occurs between the gaseous O2 and that adsorbed onto molecular sieve, if desorption and adsorption are incomplete. As the fraction of released or untrapped O2 becomes smaller with decreasing trapping temperature (from 0 to -130°C), the isotopic fractionation becomes larger. Approximately half of the total adsorbed O2 is released from the molecular sieve during desorption at -114°C, which is the temperature recommended for separation from NF3 (retained on the molecular sieve), and this will interfere with (17)O/(16)O measurements. The use of a single cold finger should be avoided, because partial desorption is accompanied by oxygen isotopic fractionation, thereby resulting in inaccurate isotopic data. The use of a dual cold finger arrangement is recommended because, as we have confirmed, the transfer of O2 from the first trap to the second is almost 100%. However, even under these conditions, a small isotopic fractionation (0.18 ± 0.05‰ in δ(17)O values and 0.26 ± 0.06‰ in δ(18)O values) occurred, with O2 in the second trap being isotopically enriched in the heavier isotopes. Copyright © 2014 John Wiley & Sons, Ltd.

A novel glucose oxidase biosensor based on poly([2,2';5',2″]-terthiophene-3'-carbaldehyde) modified electrode.

PubMed

Guler, Muhammet; Turkoglu, Vedat; Kivrak, Arif

2015-08-01

In the study, the electrochemical behavior of glucose oxidase (GOx) immobilized on poly([2,2';5',2″]-terthiophene-3'-carbaldehyde) (poly(TTP)) modified glassy carbon electrode (GCE) was investigated. The biosensor (poly(TTP)/GOx/GCE) showed a pair of redox peaks in 0.1 M phosphate buffer (pH 7.4) solution in the absence of oxygen the co-substrate of GOx. In here, Poly(TTP)/GOx/GCE biosensor acts as the co-substrate instead of oxygen. Upon the addition of glucose, the reduction and oxidation peak currents increased until the active site of GOx was fully saturated with glucose. The apparent m was estimated 26.13 mM from Lineweaver-Burk graph. The biosensor displayed a good stability and bioactivity. The biosensor showed a high sensitivity (56.1 nA/mM), a linear range (from 0.5 to 20.15 mM), and a good reproducibility with 3.6% of relative standard deviation. In addition, the interference currents of glycin, ascorbic acid, histidine, uric acid, dopamine, arginine, and fructose on GOx biosensor were investigated. All that substances exhibited an interference current under 10%. It was not shown a marked difference between GOx biosensor and spectrophotometric measurement of glucose in serum examples. UV-visible spectroscopy and scanning electron microscopy (SEM) experiments of the biosensor were also performed. Copyright © 2015 Elsevier B.V. All rights reserved.

Thermodynamic properties of oxygen and nitrogen III

NASA Technical Reports Server (NTRS)

Stewart, R. B.; Jacobsen, R. T.; Myers, A. F.

1972-01-01

The final equation for nitrogen was determined. In the work on the equation of state for nitrogen, coefficients were determined by constraining the critical point to selected critical point parameters. Comparisons of this equation with all the P-density-T data were made, as well as comparisons to all other thermodynamic data reported in the literature. The extrapolation of the equation of state was studied for vapor to higher temperatures and lower temperatures, and for the liquid surface to the saturated liquid and the fusion lines. A new vapor pressure equation was also determined which was constrained to the same critical temperature, pressure, and slope (dP/dT) as the equation of state. Work on the equation of state for oxygen included studies for improving the equation at the critical point. Comparisons of velocity of sound data for oxygen were also made between values calculated with a preliminary equation of state and experimental data. Functions for the calculation of the derived thermodynamic properties using the equation of state are given, together with the derivative and integral functions for the calculation of the thermodynamic properties using the equations of state. Summary tables of the thermodynamic properties of nitrogen and oxygen are also included to serve as a check for those preparing computer programs using the equations of state.

Study of sputtered ZnO modified by Direct Laser Interference Patterning: Structural characterization and temperature simulation

NASA Astrophysics Data System (ADS)

Parellada-Monreal, L.; Castro-Hurtado, I.; Martínez-Calderón, M.; Rodriguez, A.; Olaizola, S. M.; Gamarra, D.; Lozano, J.; Mandayo, G. G.

2018-05-01

ZnO thin film sputtered on alumina substrate is processed by Direct Laser Interference Patterning (DLIP). The heat transfer equation has been simulated for interference patterns with a period of 730 nm and two different fluences (85 mJ/cm2 and 165 mJ/cm2). A thermal threshold of 900 K, where crystal modification occurs has been calculated, indicating a lateral and depth processing around 173 nm and 140 nm, respectively. The experimentally reproduced samples have been analyzed from the structural and composition point of view and compared to conventional thermal treatments at three different temperatures (600 °C, 700 °C and 800 °C). Promising properties have been observed for the laser treated samples, such as low influence on the thin film/substrate interface, an improvement of the crystallographic structure, as well as a decrease of the oxygen content from O/Zn = 2.10 to 1.38 for the highest fluence, getting closer to the stoichiometry. The DLIP characteristics could be suitable for the replacement of annealing process in the case of substrates that cannot achieve high temperatures as most of flexible substrates.

Aspects of a Distinct Cytotoxicity of Selenium Salts and Organic Selenides in Living Cells with Possible Implications for Drug Design.

PubMed

Estevam, Ethiene Castellucci; Witek, Karolina; Faulstich, Lisa; Nasim, Muhammad Jawad; Latacz, Gniewomir; Domínguez-Álvarez, Enrique; Kieć-Kononowicz, Katarzyna; Demasi, Marilene; Handzlik, Jadwiga; Jacob, Claus

2015-07-31

Selenium is traditionally considered as an antioxidant element and selenium compounds are often discussed in the context of chemoprevention and therapy. Recent studies, however, have revealed a rather more colorful and diverse biological action of selenium-based compounds, including the modulation of the intracellular redox homeostasis and an often selective interference with regulatory cellular pathways. Our basic activity and mode of action studies with simple selenium and tellurium salts in different strains of Staphylococcus aureus (MRSA) and Saccharomyces cerevisiae indicate that such compounds are sometimes not particularly toxic on their own, yet enhance the antibacterial potential of known antibiotics, possibly via the bioreductive formation of insoluble elemental deposits. Whilst the selenium and tellurium compounds tested do not necessarily act via the generation of Reactive Oxygen Species (ROS), they seem to interfere with various cellular pathways, including a possible inhibition of the proteasome and hindrance of DNA repair. Here, organic selenides are considerably more active compared to simple salts. The interference of selenium (and tellurium) compounds with multiple targets could provide new avenues for the development of effective antibiotic and anticancer agents which may go well beyond the traditional notion of selenium as a simple antioxidant.

Transition metal substituted SrTiO3 perovskite oxides as promising functional materials for oxygen sensor

NASA Astrophysics Data System (ADS)

Misra, Sunasira

2012-07-01

Modern industries employ several gases as process fluids. Leakage of these gases in the operating area could lead to undesirable consequences. Even in chemical industries, which use large quantities of inert gases in confined areas, accidental leakage of these process gases would result in the reduction of oxygen partial pressure in atmospheric air. For instance, large amounts of gaseous nitrogen and argon are used in pharmaceutical industries, gas filling/bottling plants, operating area of Fast Breeder reactors, etc. Fall of concentration of oxygen in air below 17% could lead to life risk (Asphyxiation) of the working personnel that has to be checked well in advance. Further, when the leaking gas is of explosive nature, its damage potential would be very high if its concentration level in air increases beyond its lower explosive limit. Surveillance of the ambient within these industries at the critical areas and also in the environment around them for oxygen therefore becomes highly essential. Sensitive and selective gas sensors made of advanced materials are required to meet this demand of monitoring environmental pollution. The perovskite class of oxides (ABO3) is chemically stable even at high temperatures and can tolerate large levels of dopants without phase transformations. The electronic properties of this parent functional material can be tailored by adding appropriate dopants that exhibit different valence states. Aliovalent transition metal substituted SrTiO3 perovskites are good mixed ionic and electronic conductors and potential candidates for sensing oxygen at percentage level exploiting their oxygen pressure dependent electrical conductivity. This paper presents the preparation, study of electrical conductivity and oxygen-sensing characteristics of iron and cobalt substituted SrTiO3.

Microfabricated Collector-Generator Electrode Sensor for Measuring Absolute pH and Oxygen Concentrations.

PubMed

Dengler, Adam K; Wightman, R Mark; McCarty, Gregory S

2015-10-20

Fast-scan cyclic voltammetry (FSCV) has attracted attention for studying in vivo neurotransmission due to its subsecond temporal resolution, selectivity, and sensitivity. Traditional FSCV measurements use background subtraction to isolate changes in the local electrochemical environment, providing detailed information on fluctuations in the concentration of electroactive species. This background subtraction removes information about constant or slowly changing concentrations. However, determination of background concentrations is still important for understanding functioning brain tissue. For example, neural activity is known to consume oxygen and produce carbon dioxide which affects local levels of oxygen and pH. Here, we present a microfabricated microelectrode array which uses FSCV to detect the absolute levels of oxygen and pH in vitro. The sensor is a collector-generator electrode array with carbon microelectrodes spaced 5 μm apart. In this work, a periodic potential step is applied at the generator producing transient local changes in the electrochemical environment. The collector electrode continuously performs FSCV enabling these induced changes in concentration to be recorded with the sensitivity and selectivity of FSCV. A negative potential step applied at the generator produces a transient local pH shift at the collector. The generator-induced pH signal is detected using FSCV at the collector and correlated to absolute solution pH by postcalibration of the anodic peak position. In addition, in oxygenated solutions a negative potential step at the generator produces hydrogen peroxide by reducing oxygen. Hydrogen peroxide is detected with FSCV at the collector electrode, and the magnitude of the oxidative peak is proportional to absolute oxygen concentrations. Oxygen interference on the pH signal is minimal and can be accounted for with a postcalibration.

Human Adipose‐Derived Stem Cells Expanded Under Ambient Oxygen Concentration Accumulate Oxidative DNA Lesions and Experience Procarcinogenic DNA Replication Stress

PubMed Central

Renoud, Marie‐Laure; Hoede, Claire; Gonzalez, Ignacio; Jones, Natalie; Longy, Michel; Sensebé, Luc; Cazaux, Christophe

2016-01-01

Abstract Adipose‐derived stem cells (ADSCs) have led to growing interest in cell‐based therapy because they can be easily harvested from an abundant tissue. ADSCs must be expanded in vitro before transplantation. This essential step causes concerns about the safety of adult stem cells in terms of potential transformation. Tumorigenesis is driven in its earliest step by DNA replication stress, which is characterized by the accumulation of stalled DNA replication forks and activation of the DNA damage response. Thus, to evaluate the safety of ADSCs during ex vivo expansion, we monitored DNA replication under atmospheric (21%) or physiologic (1%) oxygen concentration. Here, by combining immunofluorescence and DNA combing, we show that ADSCs cultured under 21% oxygen accumulate endogenous oxidative DNA lesions, which interfere with DNA replication by increasing fork stalling events, thereby leading to incomplete DNA replication and fork collapse. Moreover, we found by RNA sequencing (RNA‐seq) that culture of ADSCs under atmospheric oxygen concentration leads to misexpression of cell cycle and DNA replication genes, which could contribute to DNA replication stress. Finally, analysis of acquired small nucleotide polymorphism shows that expansion of ADSCs under 21% oxygen induces a mutational bias toward deleterious transversions. Overall, our results suggest that expanding ADSCs at a low oxygen concentration could reduce the risk for DNA replication stress‐associated transformation, as occurs in neoplastic tissues. Stem Cells Translational Medicine 2017;6:68–76 PMID:28170194

Cognitive responses to hypobaric hypoxia: implications for aviation training

PubMed Central

Neuhaus, Christopher; Hinkelbein, Jochen

2014-01-01

The aim of this narrative review is to provide an overview on cognitive responses to hypobaric hypoxia and to show relevant implications for aviation training. A principal element of hypoxia-awareness training is the intentional evocation of hypoxia symptoms during specific training sessions within a safe and controlled environment. Repetitive training should enable pilots to learn and recognize their personal hypoxia symptoms. A time span of 3–6 years is generally considered suitable to refresh knowledge of the more subtle and early symptoms especially. Currently, there are two different technical approaches available to induce hypoxia during training: hypobaric chamber training and reduced-oxygen breathing devices. Hypoxia training for aircrew is extremely important and effective, and the hypoxia symptoms should be emphasized clearly to aircrews. The use of tight-fitting masks, leak checks, and equipment checks should be taught to all aircrew and reinforced regularly. It is noteworthy that there are major differences in the required quality and quantity of hypoxia training for both military and civilian pilots. PMID:25419162

Asynchronous error-correcting secure communication scheme based on fractional-order shifting chaotic system

NASA Astrophysics Data System (ADS)

Chao, Luo

2015-11-01

In this paper, a novel digital secure communication scheme is firstly proposed. Different from the usual secure communication schemes based on chaotic synchronization, the proposed scheme employs asynchronous communication which avoids the weakness of synchronous systems and is susceptible to environmental interference. Moreover, as to the transmission errors and data loss in the process of communication, the proposed scheme has the ability to be error-checking and error-correcting in real time. In order to guarantee security, the fractional-order complex chaotic system with the shifting of order is utilized to modulate the transmitted signal, which has high nonlinearity and complexity in both frequency and time domains. The corresponding numerical simulations demonstrate the effectiveness and feasibility of the scheme.

Glucose-functionalized amino-OPEs as biocompatible photosensitizers in PDT.

PubMed

Deni, Elisa; Zamarrón, Alicia; Bonaccorsi, Paola; Carmen Carreño, M; Juarranz, Ángeles; Puntoriero, Fausto; Sciortino, Maria Teresa; Ribagorda, María; Barattucci, Anna

2016-03-23

Photodynamic therapy (PDT) is a minimally invasive procedure that can provide a selective eradication of neoplastic diseases by the combined effect of a photosensitizer, light and oxygen. New amino oligo(phenylene-ethynylene)s (OPEs), bearing hydrophilic glucoside terminations, have been prepared, characterized and tested as photosensitizers in PDT. The effectiveness of these compounds in combination with UVA light has been checked on two tumor cell lines (HEp-2 and HeLa cells, derived from a larynx carcinoma and a cervical carcinoma, respectively). The compounds triggered a mitotic blockage that led to the cell death, being the effect active up to 3 μm concentration. The photophysical properties of OPEs, such as high quantum yield, stability, singlet oxygen production, biocompatibility, easy cell-internalization and very good response even at low concentration, make them promising photosensitizers in the application of PDT. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Anesthesia equipment malfunction: origins and clinical recognition.

PubMed Central

McIntyre, J. W.

1979-01-01

Equipment malfunction is a problem of particular importance during anesthesia and resuscitation. A review of published reports shows that the most common clinical events involve endotracheal tubes, the inspired oxygen concentration, the volume of inspired anesthetic vapours and gases, and pressures in the breathing or ventilation system. It is concluded that protection of a patient from equipment malfunction depends on: (a) appropriate application of standards set by a national standards association; (b) careful evaluation of equipment prior to purchase; (c) comprehension of equipment function by the user; (d) conscientious routine servicing of all systems concerned with anesthesia and resuscitation, and checking after service and before clinical use; (e) preanesthesia testing of equipment, including the use of an oxygen analyser in the breathing circuit; (f) early inclusion of equipment malfunction in the differential diagnosis of events during anesthesia; and (g) rapid action that cannot present a new hazard to the patient to correct the results of apparatus malfunction. PMID:436069

Evaluation of hematocrit interference with MyStar extra and seven competitive devices.

PubMed

Demircik, Filiz; Ramljak, Sanja; Hermanns, Iris; Pfützner, Anke; Pfützner, Andreas

2015-03-01

In previous studies, meters employing dynamic electrochemistry (DE), have been shown to correct for hematocrit (HCT) interference. This laboratory investigation assessed the HCT stability of MyStar Extra (Sanofi) in comparison to 7 competitive devices (Accu-Chek Aviva Nano & Accu-Chek Performa, Roche Diagnostics; Contour XT and Contour Link, Bayer; FreeStyle Freedom Lite, Abbott; MyLife Pura, Ypsomed; OneTouch Verio Pro, LifeScan). Venous heparinized blood was freshly drawn, immediately aliquoted, and manipulated to contain 3 different blood glucose concentrations (50-80 mg/dL, 150-180 mg/dL, and 350-400 mg/dL) and 5 different HCT levels (20-25%, 30-35%, 40-45%, 50-55%, and 60-65%). After careful oxygenation to normal blood oxygen pressure, each of the 15 different samples was measured 8 times with 2 devices and 2 strip lots of each meter (32 measurements/meter/sample). YSI Stat 2300 served as laboratory reference method. Next to determination of the mean absolute relative deviation (MARD), stability to HCT influence was assumed, when less than 10% difference occurred between the highest and lowest mean glucose deviations in relation to HCT over all tested glucose ranges (HIF: hematocrit interference factor). Four of the devices showed stable performance: Contour XT (MARD: 1.3%/HIF: 6.1%), MyStar Extra (4.7%/7.1%), OneTouch Verio Pro (4.5%/7.3%), and Contour Link (6.3%/9.3%). The 4 other meters were influenced by HCT (Accu-Chek Performa: 4.7%/20.9%, Accu-Chek Aviva Nano: 4.5%/22.4%, FreeStyle Freedom Lite: 4.8%/24.5%; MyLife Pura: 6.4%/28.7%). In this study, all meters showed a good accuracy, but only 50% of them, including MyStar Extra, were shown to reliably correct for potential hematocrit influence on the meter results. © 2014 Diabetes Technology Society.

Evaluation of Hematocrit Interference With MyStar Extra and Seven Competitive Devices

PubMed Central

Demircik, Filiz; Ramljak, Sanja; Hermanns, Iris; Pfützner, Anke; Pfützner, Andreas

2014-01-01

Background: In previous studies, meters employing dynamic electrochemistry (DE), have been shown to correct for hematocrit (HCT) interference. This laboratory investigation assessed the HCT stability of MyStar Extra (Sanofi) in comparison to 7 competitive devices (Accu-Chek Aviva Nano & Accu-Chek Performa, Roche Diagnostics; Contour XT and Contour Link, Bayer; FreeStyle Freedom Lite, Abbott; MyLife Pura, Ypsomed; OneTouch Verio Pro, LifeScan). Method: Venous heparinized blood was freshly drawn, immediately aliquoted, and manipulated to contain 3 different blood glucose concentrations (50-80 mg/dL, 150-180 mg/dL, and 350-400 mg/dL) and 5 different HCT levels (20-25%, 30-35%, 40-45%, 50-55%, and 60-65%). After careful oxygenation to normal blood oxygen pressure, each of the 15 different samples was measured 8 times with 2 devices and 2 strip lots of each meter (32 measurements/meter/sample). YSI Stat 2300 served as laboratory reference method. Next to determination of the mean absolute relative deviation (MARD), stability to HCT influence was assumed, when less than 10% difference occurred between the highest and lowest mean glucose deviations in relation to HCT over all tested glucose ranges (HIF: hematocrit interference factor). Results: Four of the devices showed stable performance: Contour XT (MARD: 1.3%/HIF: 6.1%), MyStar Extra (4.7%/7.1%), OneTouch Verio Pro (4.5%/7.3%), and Contour Link (6.3%/9.3%). The 4 other meters were influenced by HCT (Accu-Chek Performa: 4.7%/20.9%, Accu-Chek Aviva Nano: 4.5%/22.4%, FreeStyle Freedom Lite: 4.8%/24.5%; MyLife Pura: 6.4%/28.7%). Conclusions: In this study, all meters showed a good accuracy, but only 50% of them, including MyStar Extra, were shown to reliably correct for potential hematocrit influence on the meter results. PMID:25549636

Blood glucose meters employing dynamic electrochemistry are stable against hematocrit interference in a laboratory setting.

PubMed

Pfützner, Andreas; Musholt, Petra B; Schipper, Christina; Demircik, Filiz; Hengesbach, Carina; Flacke, Frank; Sieber, Jochen; Forst, Thomas

2013-11-01

Hematocrit (HCT) is known to be a confounding factor that interferes with many blood glucose (BG) measurement technologies, resulting in wrong readings. Dynamic electrochemistry has been identified as one possible way to correct for these potential deviations. The purpose of this laboratory investigation was to assess the HCT stability of four BG meters known to employ dynamic electrochemistry (BGStar and iBGStar, Sanofi; Wavesense Jazz, AgaMatrix; Wellion Linus, MedTrust) in comparison with three other devices (GlucoDock, Medisana; OneTouch Verio Pro, LifeScan; FreeStyle Freedom InsuLinx, Abbott-Medisense). Venous heparinized blood was immediately aliquoted after draw and manipulated to contain three different BG concentrations (60-90, 130-160, and 280-320 mg/dl) and five different HCT levels (25%, 35%, 45%, 55%, and 60%). After careful oxygenation to normal blood oxygen pressure, each of the resulting 15 different samples was measured six times with three devices and three strip lots of each meter. The YSI Stat 2300 served as laboratory reference method. Stability to HCT influence was assumed when less than 10% difference occurred between the highest and lowest mean glucose deviations in relation to HCT concentrations [hematocrit interference factor (HIF)]. Five of the investigated self-test meters showed a stable performance with the different HCT levels tested in this investigation: BGStar (HIF 4.6%), iBGStar (6.6%), Wavesense Jazz (4.1%), Wellion Linus (8.5%), and OneTouch Verio Pro (6.2%). The two other meters were influenced by HCT (FreeStyle InsuLinx 17.8%; GlucoDock 46.5%). In this study, meters employing dynamic electrochemistry, as used in the BGStar and iBGStar devices, were shown to correct for potential HCT influence on the meter results. Dynamic electrochemistry appears to be an effective way to handle this interfering condition. © 2013 Diabetes Technology Society.

Blood Glucose Meters Employing Dynamic Electrochemistry Are Stable against Hematocrit Interference in a Laboratory Setting

PubMed Central

Pfützner, Andreas; Musholt, Petra B.; Schipper, Christina; Demircik, Filiz; Hengesbach, Carina; Flacke, Frank; Sieber, Jochen; Forst, Thomas

2013-01-01

Background Hematocrit (HCT) is known to be a confounding factor that interferes with many blood glucose (BG) measurement technologies, resulting in wrong readings. Dynamic electrochemistry has been identified as one possible way to correct for these potential deviations. The purpose of this laboratory investigation was to assess the HCT stability of four BG meters known to employ dynamic electrochemistry (BGStar and iBGStar, Sanofi; Wavesense Jazz, AgaMatrix; Wellion Linus, MedTrust) in comparison with three other devices (GlucoDock, Medisana; OneTouch Verio Pro, LifeScan; FreeStyle Freedom InsuLinx, Abbott-Medisense). Methods Venous heparinized blood was immediately aliquoted after draw and manipulated to contain three different BG concentrations (60–90, 130–160, and 280–320 mg/dl) and five different HCT levels (25%, 35%, 45%, 55%, and 60%). After careful oxygenation to normal blood oxygen pressure, each of the resulting 15 different samples was measured six times with three devices and three strip lots of each meter. The YSI Stat 2300 served as laboratory reference method. Stability to HCT influence was assumed when less than 10% difference occurred between the highest and lowest mean glucose deviations in relation to HCT concentrations [hematocrit interference factor (HIF)]. Results Five of the investigated self-test meters showed a stable performance with the different HCT levels tested in this investigation: BGStar (HIF 4.6%), iBGStar (6.6%), Wavesense Jazz (4.1%), Wellion Linus (8.5%), and OneTouch Verio Pro (6.2%). The two other meters were influenced by HCT (FreeStyle InsuLinx 17.8%; GlucoDock 46.5%). Conclusions In this study, meters employing dynamic electrochemistry, as used in the BGStar and iBGStar devices, were shown to correct for potential HCT influence on the meter results. Dynamic electrochemistry appears to be an effective way to handle this interfering condition. PMID:24351179

Ketogenic diet for high partial pressure oxygen diving.

PubMed

Valadao, Jason M; Vigilante, John A; DiGeorge, Nicholas W; O'Connor, Sunila E; Bear, Alexandria; Kenyon, Jeffrey; Annis, Heather; Dituri, Joseph; Dituri, Amy E; Whelan, Harry T

2014-01-01

A ketogenic diet (KD) may decrease central nervous system oxygen toxicity symptoms in divers, and in view of this implication a feasibility/ toxicity pilot study was performed to demonstrate tolerance of KD while performing normal diving profiles. The exact mechanism of neuroprotection from the KD remains unknown; however, evidence to support the efficacy of the KD in reducing seizures is present in epilepsy and oxygen toxicity studies, and may provide valuable insight in diving activities. Three divers (two males and one female ages 32-45 with a history of deep diving and high pO2 exposure) on the KD made dives to varying depths in Hawaii using fully closed-circuit MK-15 and Inspiration rebreathers. These rebreathers have an electronically controlled set point, allowing the divers to monitor and control the oxygen level in the breathing loop, which can be varied manually by the divers. Oxygen level was varied during descent, bottom depth and ascent (decompression). Divers fasted for 12-18 hours before diet initiation. The ketosis level was verified by urinating on a Ketostix (reagent strips for urinalysis). Ketosis was achieved and was easily monitored with Ketostix in the simulated operational environment. The KD did not interfere with the diving mission; no seizure activity or signs or symptoms of CNS toxicity were observed, and there were no adverse effects noted by the divers while on the KD.

From Field Notes to Data Portal - A Scalable Data QA/QC Framework for Tower Networks: Progress and Preliminary Results

NASA Astrophysics Data System (ADS)

Sturtevant, C.; Hackley, S.; Lee, R.; Holling, G.; Bonarrigo, S.

2017-12-01

Quality assurance and control (QA/QC) is one of the most important yet challenging aspects of producing research-quality data. Data quality issues are multi-faceted, including sensor malfunctions, unmet theoretical assumptions, and measurement interference from humans or the natural environment. Tower networks such as Ameriflux, ICOS, and NEON continue to grow in size and sophistication, yet tools for robust, efficient, scalable QA/QC have lagged. Quality control remains a largely manual process heavily relying on visual inspection of data. In addition, notes of measurement interference are often recorded on paper without an explicit pathway to data flagging. As such, an increase in network size requires a near-proportional increase in personnel devoted to QA/QC, quickly stressing the human resources available. We present a scalable QA/QC framework in development for NEON that combines the efficiency and standardization of automated checks with the power and flexibility of human review. This framework includes fast-response monitoring of sensor health, a mobile application for electronically recording maintenance activities, traditional point-based automated quality flagging, and continuous monitoring of quality outcomes and longer-term holistic evaluations. This framework maintains the traceability of quality information along the entirety of the data generation pipeline, and explicitly links field reports of measurement interference to quality flagging. Preliminary results show that data quality can be effectively monitored and managed for a multitude of sites with a small group of QA/QC staff. Several components of this framework are open-source, including a R-Shiny application for efficiently monitoring, synthesizing, and investigating data quality issues.

PAMP-induced defense responses in potato require both salicylic acid and jasmonic acid.

PubMed

Halim, Vincentius A; Altmann, Simone; Ellinger, Dorothea; Eschen-Lippold, Lennart; Miersch, Otto; Scheel, Dierk; Rosahl, Sabine

2009-01-01

To elucidate the molecular mechanisms underlying pathogen-associated molecular pattern (PAMP)-induced defense responses in potato (Solanum tuberosum), the role of the signaling compounds salicylic acid (SA) and jasmonic acid (JA) was analyzed. Pep-13, a PAMP from Phytophthora, induces the accumulation of SA, JA and hydrogen peroxide, as well as the activation of defense genes and hypersensitive-like cell death. We have previously shown that SA is required for Pep-13-induced defense responses. To assess the importance of JA, RNA interference constructs targeted at the JA biosynthetic genes, allene oxide cyclase and 12-oxophytodienoic acid reductase, were expressed in transgenic potato plants. In addition, expression of the F-box protein COI1 was reduced by RNA interference. Plants expressing the RNA interference constructs failed to accumulate the respective transcripts in response to wounding or Pep-13 treatment, neither did they contain significant amounts of JA after elicitation. In response to infiltration of Pep-13, the transgenic plants exhibited a highly reduced accumulation of reactive oxygen species as well as reduced hypersensitive cell death. The ability of the JA-deficient plants to accumulate SA suggests that SA accumulation is independent or upstream of JA accumulation. These data show that PAMP responses in potato require both SA and JA and that, in contrast to Arabidopsis, these compounds act in the same signal transduction pathway. Despite their inability to fully respond to PAMP treatment, the transgenic RNA interference plants are not altered in their basal defense against Phytophthora infestans.

The natural greenhouse effect of atmospheric oxygen (O2) and nitrogen (N2)

NASA Astrophysics Data System (ADS)

Höpfner, M.; Milz, M.; Buehler, S.; Orphal, J.; Stiller, G.

2012-05-01

The effect of collision-induced absorption by molecular oxygen (O2) and nitrogen (N2) on the outgoing longwave radiation (OLR) of the Earth's atmosphere has been quantified. We have found that on global average under clear-sky conditions the OLR is reduced due to O2 by 0.11 Wm-2 and due to N2 by 0.17 Wm-2. Together this amounts to 15% of the OLR-reduction caused by CH4 at present atmospheric concentrations. Over Antarctica the combined effect of O2 and N2 increases on average to about 38% of CH4 with single values reaching up to 80%. This is explained by less interference of H2O spectral bands on the absorption features of O2 and N2 for dry atmospheric conditions.

Fiber optic choline biosensor

NASA Astrophysics Data System (ADS)

Wang, Hong; Cao, Xiaojian; Jia, Ke; Chai, Xueting; Lu, Hua; Lu, Zuhong

2001-10-01

A fiber optic fluorescence biosensor for choline is introduced in this paper. Choline is an important neurotransmitter in mammals. Due to the growing needs for on-site clinical monitoring of the choline, much effect has been devoted to develop choline biosensors. Fiber-optic fluorescence biosensors have many advantages, including miniaturization, flexibility, and lack of electrical contact and interference. The choline fiber-optic biosensor we designed implemented a bifurcated fiber to perform fluorescence measurements. The light of the blue LED is coupled into one end of the fiber as excitation and the emission spectrum from sensing film is monitored by fiber-spectrometer (S2000, Ocean Optics) through the other end of the fiber. The sensing end of the fiber is coated with Nafion film dispersed with choline oxidase and oxygen sensitive luminescent Ru(II) complex (Tris(2,2'-bipyridyl)dichlororuthenium(II), hexahydrate). Choline oxidase catalyzes the oxidation of choline to betaine and hydrogen peroxide while consuming oxygen. The fluorescence intensity of oxygen- sensitive Ru(II) are related to the choline concentration. The response of the fiber-optic sensor in choline solution is represented and discussed. The result indicates a low-cost, high-performance, portable choline biosensor.

Valsalva maneuver in obstetrics: the influence of peripheral circulatory changes on function of the pulse oximeter.

PubMed

Woods, A M; Queen, J S; Lawson, D

1991-12-01

Strenuous expulsive efforts involving sequential Valsalva maneuvers may result in maternal hypoxemia during the second stage of labor. Pulse oximetry has been used to assess oxygen saturation in laboring parturients, and this study was undertaken to evaluate the performance of the pulse oximeter (Nellcor) during the Valsalva maneuver. In both pregnant patients and nonpregnant volunteers, there were consistent interruptions in the transmission of oxygen saturation data during the Valsalva maneuver. To determine the physiologic events associated with this monitoring interruption, occlusive venous impedance plethysmographs and pulse volume amplitude recordings were obtained in volunteers performing the Valsalva maneuver. A marked decrease in pulse volume amplitude was noted, which adversely affected the oximeter's ability to distinguish physiologic arterial pulsations from background noise. Each Valsalva maneuver was associated with abrupt and transient changes in peripheral vascular volumes, thus presenting the oximeter with a rapidly changing signal for analysis that violated predetermined software criteria for pulse uniformity and caused an interruption in data transmission. The authors conclude that the Valsalva maneuver interferes with the ability of pulse oximeter technology to provide useful oxygen saturation data.

Tracheal intubation in critically ill patients: a comprehensive systematic review of randomized trials.

PubMed

Cabrini, Luca; Landoni, Giovanni; Baiardo Radaelli, Martina; Saleh, Omar; Votta, Carmine D; Fominskiy, Evgeny; Putzu, Alessandro; Snak de Souza, Cézar Daniel; Antonelli, Massimo; Bellomo, Rinaldo; Pelosi, Paolo; Zangrillo, Alberto

2018-01-20

We performed a systematic review of randomized controlled studies evaluating any drug, technique or device aimed at improving the success rate or safety of tracheal intubation in the critically ill. We searched PubMed, BioMed Central, Embase and the Cochrane Central Register of Clinical Trials and references of retrieved articles. Finally, pertinent reviews were also scanned to detect further studies until May 2017. The following inclusion criteria were considered: tracheal intubation in adult critically ill patients; randomized controlled trial; study performed in Intensive Care Unit, Emergency Department or ordinary ward; and work published in the last 20 years. Exclusion criteria were pre-hospital or operating theatre settings and simulation-based studies. Two investigators selected studies for the final analysis. Extracted data included first author, publication year, characteristics of patients and clinical settings, intervention details, comparators and relevant outcomes. The risk of bias was assessed with the Cochrane Collaboration's Risk of Bias tool. We identified 22 trials on use of a pre-procedure check-list (1 study), pre-oxygenation or apneic oxygenation (6 studies), sedatives (3 studies), neuromuscular blocking agents (1 study), patient positioning (1 study), video laryngoscopy (9 studies), and post-intubation lung recruitment (1 study). Pre-oxygenation with non-invasive ventilation (NIV) and/or high-flow nasal cannula (HFNC) showed a possible beneficial role. Post-intubation recruitment improved oxygenation , while ramped position increased the number of intubation attempts and thiopental had negative hemodynamic effects. No effect was found for use of a checklist, apneic oxygenation (on oxygenation and hemodynamics), videolaryngoscopy (on number and length of intubation attempts), sedatives and neuromuscular blockers (on hemodynamics). Finally, videolaryngoscopy was associated with severe adverse effects in multiple trials. The limited available evidence supports a beneficial role of pre-oxygenation with NIV and HFNC before intubation of critically ill patients. Recruitment maneuvers may increase post-intubation oxygenation. Ramped position increased the number of intubation attempts; thiopental had negative hemodynamic effects and videolaryngoscopy might favor adverse events.

The Impact of Obsessive Compulsive Personality Disorder on Cognitive Behaviour Therapy for Obsessive Compulsive Disorder.

PubMed

Gordon, Olivia M; Salkovskis, Paul M; Bream, Victoria

2016-07-01

It is often suggested that, in general, co-morbid personality disorders are likely to interfere with CBT based treatment of Axis I disorders, given that personality disorders are regarded as dispositional and are therefore considered less amenable to change than axis I psychiatric disorders. The present study aimed to investigate the impact of co-occurring obsessive-compulsive disorder (OCD) and obsessive-compulsive personality disorder (OCPD) on cognitive-behavioural treatment for OCD. 92 individuals with a diagnosis of OCD participated in this study. Data were drawn from measures taken at initial assessment and following cognitive-behavioural treatment at a specialist treatment centre for anxiety disorders. At assessment, participants with OCD and OCPD had greater overall OCD symptom severity, as well as doubting, ordering and hoarding symptoms relative to those without OCPD; however, participants with co-morbid OCD and OCPD demonstrated greater treatment gains in terms of OCD severity, checking and ordering than those without OCPD. Individuals with OCD and OCPD had higher levels of checking, ordering and overall OCD severity at initial assessment; however, at post-treatment they had similar scores to those without OCPD. The implications of these findings are discussed in the light of research on axis I and II co-morbidity and the impact of axis II disorders on treatment for axis I disorders.

A Weakest Precondition Approach to Robustness

NASA Astrophysics Data System (ADS)

Balliu, Musard; Mastroeni, Isabella

With the increasing complexity of information management computer systems, security becomes a real concern. E-government, web-based financial transactions or military and health care information systems are only a few examples where large amount of information can reside on different hosts distributed worldwide. It is clear that any disclosure or corruption of confidential information in these contexts can result fatal. Information flow controls constitute an appealing and promising technology to protect both data confidentiality and data integrity. The certification of the security degree of a program that runs in untrusted environments still remains an open problem in the area of language-based security. Robustness asserts that an active attacker, who can modify program code in some fixed points (holes), is unable to disclose more private information than a passive attacker, who merely observes unclassified data. In this paper, we extend a method recently proposed for checking declassified non-interference in presence of passive attackers only, in order to check robustness by means of weakest precondition semantics. In particular, this semantics simulates the kind of analysis that can be performed by an attacker, i.e., from public output towards private input. The choice of semantics allows us to distinguish between different attacks models and to characterize the security of applications in different scenarios.

Reduction of image-based ADI-to-AEI overlay inconsistency with improved algorithm

NASA Astrophysics Data System (ADS)

Chen, Yen-Liang; Lin, Shu-Hong; Chen, Kai-Hsiung; Ke, Chih-Ming; Gau, Tsai-Sheng

2013-04-01

In image-based overlay (IBO) measurement, the measurement quality of various measurement spectra can be judged by quality indicators and also the ADI-to-AEI similarity to determine the optimum light spectrum. However we found some IBO measured results showing erroneous indication of wafer expansion from the difference between the ADI and the AEI maps, even after their measurement spectra were optimized. To reduce this inconsistency, an improved image calculation algorithm is proposed in this paper. Different gray levels composed of inner- and outer-box contours are extracted to calculate their ADI overlay errors. The symmetry of intensity distribution at the thresholds dictated by a range of gray levels is used to determine the particular gray level that can minimize the ADI-to-AEI overlay inconsistency. After this improvement, the ADI is more similar to AEI with less expansion difference. The same wafer was also checked by the diffraction-based overlay (DBO) tool to verify that there is no physical wafer expansion. When there is actual wafer expansion induced by large internal stress, both the IBO and the DBO measurements indicate similar expansion results. The scanning white-light interference microscope was used to check the variation of wafer warpage during the ADI and AEI stages. It predicts a similar trend with the overlay difference map, confirming the internal stress.

Incremental rate of prefrontal oxygenation determines performance speed during cognitive Stroop test: the effect of ageing.

PubMed

Endo, Kana; Liang, Nan; Idesako, Mitsuhiro; Ishii, Kei; Matsukawa, Kanji

2018-02-19

Cognitive function declines with age. The underlying mechanisms responsible for the deterioration of cognitive performance, however, remain poorly understood. We hypothesized that an incremental rate of prefrontal oxygenation during a cognitive Stroop test decreases in progress of ageing, resulting in a slowdown of cognitive performance. To test this hypothesis, we identified, using multichannel near-infrared spectroscopy, the characteristics of the oxygenated-hemoglobin concentration (Oxy-Hb) responses of the prefrontal cortex to both incongruent Stroop and congruent word-reading test. Spatial distributions of the significant changes in the three components (initial slope, peak amplitude, and area under the curve) of the Oxy-Hb response were compared between young and elderly subjects. The Stroop interference time (as a difference in total periods for executing Stroop and word-reading test, respectively) approximately doubled in elderly as compared to young subjects. The Oxy-Hb in the rostrolateral, but not caudal, prefrontal cortex increased during the Stroop test in both age groups. The initial slope of the Oxy-Hb response, rather than the peak and area under the curve, had a strong correlation with cognitive performance speed. Taken together, it is likely that the incremental rate of prefrontal oxygenation may decrease in progress of ageing, resulting in a decline in cognitive performance.

The locus coeruleus-norepinephrine network optimizes coupling of cerebral blood volume with oxygen demand.

PubMed

Bekar, Lane K; Wei, Helen S; Nedergaard, Maiken

2012-12-01

Given the brain's uniquely high cell density and tissue oxygen levels bordering on hypoxia, the ability to rapidly and precisely match blood flow to constantly changing patterns in neural activity is an essential feature of cerebrovascular regulation. Locus coeruleus-norepinephrine (LC-NE) projections innervate the cerebral vasculature and can mediate vasoconstriction. However, function of the LC-mediated constriction in blood-flow regulation has never been addressed. Here, using intrinsic optical imaging coupled with an anesthesia regimen that only minimally interferes with LC activity, we show that NE enhances spatial and temporal aspects of functional hyperemia in the mouse somatosensory cortex. Increasing NE levels in the cortex using an α(2)-adrenergic receptor antagonist paradoxically reduces the extent of functional hyperemia while enhancing the surround blood-flow reduction. However, the NE-mediated vasoconstriction optimizes spatial and temporal focusing of the hyperemic response resulting in a sixfold decrease in the disparity between blood volume and oxygen demand. In addition, NE-mediated vasoconstriction accelerated redistribution to subsequently active regions, enhancing temporal synchronization of blood delivery. These observations show an important role for NE in optimizing neurovascular coupling. As LC neuron loss is prominent in Alzheimer and Parkinson diseases, the diminished ability to couple blood volume to oxygen demand may contribute to their pathogenesis.

Mathematical models for space shuttle ground systems

NASA Technical Reports Server (NTRS)

Tory, E. G.

1985-01-01

Math models are a series of algorithms, comprised of algebraic equations and Boolean Logic. At Kennedy Space Center, math models for the Space Shuttle Systems are performed utilizing the Honeywell 66/80 digital computers, Modcomp II/45 Minicomputers and special purpose hardware simulators (MicroComputers). The Shuttle Ground Operations Simulator operating system provides the language formats, subroutines, queueing schemes, execution modes and support software to write, maintain and execute the models. The ground systems presented consist primarily of the Liquid Oxygen and Liquid Hydrogen Cryogenic Propellant Systems, as well as liquid oxygen External Tank Gaseous Oxygen Vent Hood/Arm and the Vehicle Assembly Building (VAB) High Bay Cells. The purpose of math modeling is to simulate the ground hardware systems and to provide an environment for testing in a benign mode. This capability allows the engineers to check out application software for loading and launching the vehicle, and to verify the Checkout, Control, & Monitor Subsystem within the Launch Processing System. It is also used to train operators and to predict system response and status in various configurations (normal operations, emergency and contingent operations), including untried configurations or those too dangerous to try under real conditions, i.e., failure modes.

Inaccurate pulse CO-oximetry of carboxyhemoglobin due to digital clubbing: case report.

PubMed

Harlan, Nicole; Weaver, Lindell K; Deru, Kayla

2016-01-01

Newer pulse CO-oximeters provide a non-invasive and quick means of measuring oxyhemoglobin, carboxyhemoglobin and methemoglobin. Clubbing has been reported to cause inaccuracy in pulse oximeters. We present a case of inaccurate carboxy-hemoglobin measurement by pulse CO-oximetry due to digital clubbing. An 18-year-old man with a history of cystic fibrosis presented after a suicide attempt by inhalation of exhaust. At the initial emergency department evaluation, his blood carboxyhemoglobin was 33%. He was intubated, placed on 100% oxygen and transferred to our facility. Upon arrival, we placed three different pulse CO-oximeters on different fingers and toes. Carboxyhemoglobin levels measured by these meters ranged from 9%-11%. A venous blood gas drawn on arrival showed a carboxyhemoglobin level of 2.3% after four hours on 100% oxygen by endotracheal tube. Thirty minutes later, we checked arterial blood gas, which revealed a COHb level of 0.9%. Again, non-invasive carboxyhemoglobin measurements read 10%. The patient was treated with hyperbaric oxygen for carbon monoxide poisoning. This case suggests that non-invasive measurements of carboxyhemoglobin should be correlated with the clinic history and with an arterial or venous blood gas oximetry analysis.

Reactive Oxygen Species in the Regulation of Synaptic Plasticity and Memory

PubMed Central

Klann, Eric

2011-01-01

Abstract The brain is a metabolically active organ exhibiting high oxygen consumption and robust production of reactive oxygen species (ROS). The large amounts of ROS are kept in check by an elaborate network of antioxidants, which sometimes fail and lead to neuronal oxidative stress. Thus, ROS are typically categorized as neurotoxic molecules and typically exert their detrimental effects via oxidation of essential macromolecules such as enzymes and cytoskeletal proteins. Most importantly, excessive ROS are associated with decreased performance in cognitive function. However, at physiological concentrations, ROS are involved in functional changes necessary for synaptic plasticity and hence, for normal cognitive function. The fine line of role reversal of ROS from good molecules to bad molecules is far from being fully understood. This review focuses on identifying the multiple sources of ROS in the mammalian nervous system and on presenting evidence for the critical and essential role of ROS in synaptic plasticity and memory. The review also shows that the inability to restrain either age- or pathology-related increases in ROS levels leads to opposite, detrimental effects that are involved in impairments in synaptic plasticity and memory function. Antioxid. Redox Signal. 14, 2013–2054. PMID:20649473

The association between aerobic fitness and cognitive function in older men mediated by frontal lateralization.

PubMed

Hyodo, Kazuki; Dan, Ippeita; Kyutoku, Yasushi; Suwabe, Kazuya; Byun, Kyeongho; Ochi, Genta; Kato, Morimasa; Soya, Hideaki

2016-01-15

Previous studies have shown that higher aerobic fitness is related to higher cognitive function and higher task-related prefrontal activation in older adults. However, a holistic picture of these factors has yet to be presented. As a typical age-related change of brain activation, less lateralized activity in the prefrontal cortex during cognitive tasks has been observed in various neuroimaging studies. Thus, this study aimed to reveal the relationship between aerobic fitness, cognitive function, and frontal lateralization. Sixty male older adults each performed a submaximal incremental exercise test to determine their oxygen intake (V·O2) at ventilatory threshold (VT) in order to index their aerobic fitness. They performed a color-word Stroop task while prefrontal activation was monitored using functional near infrared spectroscopy. As an index of cognitive function, Stroop interference time was analyzed. Partial correlation analyses revealed significant correlations among higher VT, shorter Stroop interference time and greater left-lateralized dorsolateral prefrontal cortex (DLPFC) activation when adjusting for education. Moreover, mediation analyses showed that left-lateralized DLPFC activation significantly mediated the association between VT and Stroop interference time. These results suggest that higher aerobic fitness is associated with cognitive function via lateralized frontal activation in older adults. Copyright © 2015 Elsevier Inc. All rights reserved.

Paradoxical effect of mitochondrial respiratory chain impairment on insulin signaling and glucose transport in adipose cells.

PubMed

Shi, Xiarong; Burkart, Alison; Nicoloro, Sarah M; Czech, Michael P; Straubhaar, Juerg; Corvera, Silvia

2008-11-07

Adipocyte function is crucial for the control of whole body energy homeostasis. Pathway analysis of differentiating 3T3-L1 adipocytes reveals that major metabolic pathways induced during differentiation involve mitochondrial function. However, it is not clear why differentiated white adipocytes require enhanced respiratory chain activity relative to pre-adipocytes. To address this question, we used small interference RNA to interfere with the induction of the transcription factor Tfam, which is highly induced between days 2 and 4 of differentiation and is crucial for replication of mitochondrial DNA. Interference with Tfam resulted in cells with decreased respiratory chain capacity, reflected by decreased basal oxygen consumption, and decreased mitochondrial ATP synthesis, but no difference in many other adipocyte functions or expression levels of adipose-specific genes. However, insulin-stimulated GLUT4 translocation to the cell surface and subsequent glucose transport are impaired in Tfam knockdown cells. Paradoxically, insulin-stimulated Akt phosphorylation is significantly enhanced in these cells. These studies reveal independent links between mitochondrial function, insulin signaling, and glucose transport, in which impaired respiratory chain activity enhances insulin signaling to Akt phosphorylation, but impairs GLUT4 translocation. These results indicate that mitochondrial respiratory chain dysfunction in adipocytes can cause impaired insulin responsiveness of GLUT4 translocation by a mechanism downstream of the Akt protein kinase.

Trace lead analysis based on carbon-screen-printed-electrodes modified via 4-carboxy-phenyl diazonium salt electroreduction.

PubMed

Bouden, Sarra; Chaussé, Annie; Dorbes, Stephane; El Tall, Omar; Bellakhal, Nizar; Dachraoui, Mohamed; Vautrin-Ul, Christine

2013-03-15

This paper describes the use of 4-carboxyphenyl-grafted screen-printed carbon electrodes (4-CP-SPEs) for trace lead analysis. These novel and simple use of electrodes were easily prepared by the electrochemical reduction of the corresponding diazonium salt. Pb detection was then performed by a three-steps method in order to avoid oxygen interference: (i) immersion of the grafted screen-printed electrode (SPE) in the sample and adsorption of Pb(II), (ii) reduction of adsorbed Pb(II) by chronoamperometry (CA), and (iii) oxidation of Pb by Anodic Square Wave Voltammetry (SWV). The reoxidation response was exploited for lead detection and quantification. In order to optimize the analytical responses, the influence of the adsorption medium pH and the adsorption time were investigated. Moreover, an interference study was carried out with Cu(II), Hg(II), Al(III), Mn(II), Zn(II), Cd(II) and no major interference can be expected to quantify Pb(II). The described method provided a limit of detection and a limit of quantification of 1.2 × 10(-9)M and 4.1 × 10(-9)M, respectively. These performances indicate that the 4-CP-SPE could be considered as an efficient tool for environmental analysis. Copyright © 2013 Elsevier B.V. All rights reserved.

Measuring polarization dependent dispersion of non-polarizing beam splitter cubes with spectrally resolved white light interferometry

NASA Astrophysics Data System (ADS)

Csonti, K.; Hanyecz, V.; Mészáros, G.; Kovács, A. P.

2017-06-01

In this work we have measured the group-delay dispersion of an empty Michelson interferometer for s- and p-polarized light beams applying two different non-polarizing beam splitter cubes. The interference pattern appearing at the output of the interferometer was resolved with two different spectrometers. It was found that the group-delay dispersion of the empty interferometer depended on the polarization directions in case of both beam splitter cubes. The results were checked by inserting a glass plate in the sample arm of the interferometer and similar difference was obtained for the two polarization directions. These results show that to reach high precision, linearly polarized white light beam should be used and the residual dispersion of the empty interferometer should be measured at both polarization directions.

Recording of electrohysterogram laplacian potential.

PubMed

Alberola-Rubio, J; Garcia-Casado, J; Ye-Lin, Y; Prats-Boluda, G; Perales, A

2011-01-01

Preterm birth is the main cause of the neonatal morbidity. Noninvasive recording of uterine myoelectrical activity (electrohysterogram, EHG) could be an alternative to the monitoring of uterine dynamics which are currently based on tocodynamometers (TOCO). The analysis of uterine electromyogram characteristics could help the early diagnosis of preterm birth. Laplacian recordings of other bioelectrical signals have proved to enhance spatial selectivity and to reduce interferences in comparison to monopolar and bipolar surface recordings. The main objective of this paper is to check the feasibility of the noninvasive recording of uterine myoelectrical activity by means of laplacian techniques. Four bipolar EHG signals, discrete laplacian obtained from five monopolar electrodes and the signals picked up by two active concentric-ringed-electrodes were recorded on 5 women with spontaneous or induced labor. Intrauterine pressure (IUP) and TOCO were also simultaneously recorded. To evaluate the uterine contraction detectability of the different noninvasive methods in comparison to IUP the contractions consistency index (CCI) was calculated. Results show that TOCO is less consistent (83%) than most EHG bipolar recording channels (91%, 83%, 87%, and 76%) to detect the uterine contractions identified in IUP. Moreover laplacian EHG signals picked up by ringed-electrodes proved to be as consistent (91%) as the best bipolar recordings in addition to significantly reduce ECG interference.

Intensity transform and Wiener filter in measurement of blood flow in arteriography

NASA Astrophysics Data System (ADS)

Nunes, Polyana F.; Franco, Marcelo L. N.; Filho, João. B. D.; Patrocínio, Ana C.

2015-03-01

Using the arteriography examination, it is possible to check anomalies in blood vessels and diseases such as stroke, stenosis, bleeding and especially in the diagnosis of Encephalic Death in comatose individuals. Encephalic death can be diagnosed only when there is complete interruption of all brain functions, and hence the blood stream. During the examination, there may be some interference on the sensors, such as environmental factors, poor maintenance of equipment, patient movement, among other interference, which can directly affect the noise produced in angiography images. Then, we need to use digital image processing techniques to minimize this noise and improve the pixel count. Therefore, this paper proposes to use median filter and enhancement techniques for transformation of intensity using the sigmoid function together with the Wiener filter so you can get less noisy images. It's been realized two filtering techniques to remove the noise of images, one with the median filter and the other with the Wiener filter along the sigmoid function. For 14 tests quantified, including 7 Encephalic Death and 7 other cases, the technique that achieved a most satisfactory number of pixels quantified, also presenting a lesser amount of noise, is the Wiener filter sigmoid function, and in this case used with 0.03 cuttof.

Optical profilometer

NASA Astrophysics Data System (ADS)

Wieloszyńska, Aleksandra; StrÄ kowski, Marcin

2016-09-01

The profilometry plays a huge role in the most fields of science and technology. It allows to measure the profile of the surface with high-resolution. This technique is used in the fields like optic, electronic, medicine, automotive, and much more. The aim of the current work was to design and build optical profilometer based on the interference phenomena. The developed device has been working with He-Ne laser (632.8 nm). The optical parts have been chosen in order to reach the sized 2.0 mm x 1.6 mm of scanning area. The setup of the profilometer is based on Twyman-Green interferometer. Therefore, the phase distribution of the backreflected light from measured surface is recorded. The measurements are carried out with the aid of multiframe algorithms. In this approach we have used the Hariharan algorithm to obtain the exact value of the recorded phase. During tests, which have been carried out in order to check the functionality of the device, the interference patterns have been recoded and processed in order to obtain the 3D profile of measured surface. In this contribution the setup of the optical system, as well as signal processing methods are going to be presented. The brief discussion about the advantages and disadvantages, and usefulness of this approach will be carried out.

Ozone from fireworks: Chemical processes or measurement interference?

PubMed

Xu, Zheng; Nie, Wei; Chi, Xuguang; Huang, Xin; Zheng, Longfei; Xu, Zhengning; Wang, Jiaping; Xie, Yuning; Qi, Ximeng; Wang, Xinfeng; Xue, Likun; Ding, Aijun

2018-08-15

Fireworks have been identified as one ozone source by photolyzing NO 2 or O 2 and are believed to potentially be important for the nighttime ozone during firework events. In this study, we conducted both lab and field experiments to test two types of fireworks with low and high energy with the goal to distinguish whether the visible ozone signal during firework displays is real. The results suggest that previous understanding of the ozone formation mechanism during fireworks is misunderstood. Ultraviolet ray (UV)-based ozone monitors are interfered by aerosols and some specific VOCs. High-energy fireworks emit high concentrations of particular matters and low VOCs that the artificial ozone can be easily removed by an aerosol filter. Low-energy fireworks emit large amounts of VOCs mostly from the combustion of the cardboard from fireworks that largely interferes with the ozone monitor. Benzene and phenol might be major contributors to the artificial ozone signal. We further checked the nighttime ozone concentration in Jinan and Beijing, China, during Chinese New Year, a period with intense fireworks. A signal of 3-8ppbv ozone was detected and positively correlated to NO and SO 2 , suggesting a considerable influence of these chemicals in interfering with ambient ozone monitoring. Copyright © 2018 Elsevier B.V. All rights reserved.

Effect of ion beam irradiation on the structure of ZnO films deposited by a dc arc plasmatron.

PubMed

Penkov, Oleksiy V; Lee, Heon-Ju; Plaksin, Vadim Yu; Ko, Min Gook; Joa, Sang Beom; Yim, Chan Joo

2008-02-01

The deposition of polycrystalline ZnO film on a cold substrate was performed by using a plasmatron in rough vacuum condition. Low energy oxygen ion beam generated by a cold cathode ion source was introduced during the deposition process. The change of film property on the ion beam energy was checked. It is shown that irradiation by 200 eV ions improves crystalline structure of the film. Increasing of ion beam energy up to 400 eV leads to the degradation of a crystalline structure and decreases the deposition rate.

Measuring mitochondrial uncoupling protein-2 level and activity in insulinoma cells.

PubMed

Barlow, Jonathan; Hirschberg, Verena; Brand, Martin D; Affourtit, Charles

2013-01-01

Mitochondrial uncoupling protein-2 (UCP2) regulates glucose-stimulated insulin secretion (GSIS) by pancreatic beta cells-the physiological role of the beta cell UCP2 remains a subject of debate. Experimental studies informing this debate benefit from reliable measurements of UCP2 protein level and activity. In this chapter, we describe how UCP2 protein can be detected in INS-1 insulinoma cells and how it can be knocked down by RNA interference. We demonstrate briefly that UCP2 knockdown lowers glucose-induced rises in mitochondrial respiratory activity, coupling efficiency of oxidative phosphorylation, levels of mitochondrial reactive oxygen species, and insulin secretion. We provide protocols for the detection of the respective UCP2 phenotypes, which are indirect, but invaluable measures of UCP2 activity. We also introduce a convenient method to normalize cellular respiration to cell density allowing measurement of UCP2 effects on specific mitochondrial oxygen consumption. Copyright © 2013 Elsevier Inc. All rights reserved.

Mitochondrial Reactive Oxygen Species Trigger Hypoxia-Inducible Factor-Dependent Extension of the Replicative Life Span during Hypoxia▿

PubMed Central

Bell, Eric L.; Klimova, Tatyana A.; Eisenbart, James; Schumacker, Paul T.; Chandel, Navdeep S.

2007-01-01

Physiological hypoxia extends the replicative life span of human cells in culture. Here, we report that hypoxic extension of replicative life span is associated with an increase in mitochondrial reactive oxygen species (ROS) in primary human lung fibroblasts. The generation of mitochondrial ROS is necessary for hypoxic activation of the transcription factor hypoxia-inducible factor (HIF). The hypoxic extension of replicative life span is ablated by a dominant negative HIF. HIF is sufficient to induce telomerase reverse transcriptase mRNA and telomerase activity and to extend replicative life span. Furthermore, the down-regulation of the von Hippel-Lindau tumor suppressor protein by RNA interference increases HIF activity and extends replicative life span under normoxia. These findings provide genetic evidence that hypoxia utilizes mitochondrial ROS as signaling molecules to activate HIF-dependent extension of replicative life span. PMID:17562866

The effects of annealing temperature on the permittivity and electromagnetic attenuation performance of reduced graphene oxide

NASA Astrophysics Data System (ADS)

Wu, Fan; Zeng, Qiao; Xia, Yilu; Sun, Mengxiao; Xie, Aming

2018-05-01

Reduced graphene oxide (RGO) has been prepared through the thermal reduction method with different annealing temperatures to explore the effects of temperature on the permittivity and electromagnetic attenuation performance. The real and imaginary parts of permittivity increase along with the decrease in the oxygen functional group and the increase in the filler loading ratio. A composite only loaded with 1 wt. % of RGO can possess an effective electromagnetic absorption bandwidth of 7.60 GHz, when graphene oxide was reduced under 300 °C for 2 h. With the annealing temperature increased to 700 °C and the well reduced RGO loaded 7 wt. % in the composite, the electromagnetic interference shielding efficiency can get higher than 35 dB from 2 to 18 GHz. This study shows that controlling the oxygen functional groups on the RGO surface can also obtain an ideal electromagnetic attenuation performance without any other decorated nanomaterials.

XANES study of Fe-implanted strontium titanate

NASA Astrophysics Data System (ADS)

Lobacheva, O.; Goncharova, L. V.; Chavarha, M.; Sham, T. K.

2014-03-01

Properties of strontium titanate SrTiO3 (STO) depend to a great extent on the substitutional dopants and defects of crystal structure. The ion beam implantation method was used for doping STO (001) crystals with Fe at different doses. Implanted samples were then annealed at 350°C in oxygen to induce recrystallization and remove oxygen vacancies produced during ion implantation process. The effect of Fe doping and post-implantation annealing was studied by X-ray Absorption Near Edge Spectroscopy (XANES) method and Superconducting Quantum Interference Device (SQUID). XANES allowed to monitor the change in structure of STO crystals and in the local environment of Fe following the implantation and annealing steps. SQUID measurements revealed correlation between magnetic moment and Fe implantation dose. Ferromagnetic hysteresis was observed on selected Fe-implanted STO at 5 K. The observed magnetic properties can be correlated with the several Fe oxide phases in addition to the presence of O/Ti vacancies.

THESEUS: A wavelength division multiplexed/microwave subcarrier multiplexed optical network, its ATM switch applications and device requirements

NASA Astrophysics Data System (ADS)

Xin, Wei

1997-10-01

A Terabit Hybrid Electro-optical /underline[Se]lf- routing Ultrafast Switch (THESEUS) has been proposed. It is a self-routing wavelength division multiplexed (WDM) / microwave subcarrier multiplexed (SCM) asynchronous transfer mode (ATM) switch for the multirate ATM networks. It has potential to be extended to a large ATM switch as 1000 x 1000 without internal blocking. Among the advantages of the hybrid implementation are flexibility in service upgrade, relaxed tolerances on optical filtering, protocol simplification and less processing overhead. For a small ATM switch, the subcarrier can be used as output buffers to solve output contention. A mathematical analysis was conducted to evaluate different buffer configurations. A testbed has been successfully constructed. Multirate binary data streams have been switched through the testbed and error free reception ([<]10-9 bit error rate) has been achieved. A simple, intuitive theoretical model has been developed to describe the heterodyne optical beat interference. A new concept of interference time and interference length has been introduced. An experimental confirmation has been conducted. The experimental results match the model very well. It shows that a large portion of optical bandwidth is wasted due to the beat interference. Based on the model, several improvement approaches have been proposed. The photo-generated carrier lifetime of silicon germanium has been measured using time-resolved reflectivity measurement. Via oxygen ion implantation, the carrier lifetime has been reduced to as short as 1 ps, corresponding to 1 THz of photodetector bandwidth. It has also been shown that copper dopants act as recombination centers in the silicon germanium.

Ultrasonographic and laboratory markers of metabolic and cardiovascular disease risk in obese women with polycystic ovary syndrome.

PubMed

Zueff, L F N; Martins, W P; Vieira, C S; Ferriani, R A

2012-03-01

To evaluate whether the presence of polycystic ovary syndrome (PCOS) alters multiple ultrasonographic and laboratory markers of metabolic and cardiovascular disease risk in obese women without any other health condition that could interfere with combined oral contraceptive (COC) eligibility criteria. This was a case-control study evaluating 90 obese women (body mass index (BMI) ≥ 30.0 kg/m(2) and < 40 kg/m(2)) aged between 18 and 40 years without any other health condition that could interfere with COC eligibility criteria, of whom 45 had PCOS and 45 were age-matched controls. BMI, waist and hip circumference, arterial blood pressure, fasting insulin and glucose, quantitative insulin sensitivity check index (QUICKI), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, total cholesterol, triglycerides, testosterone, sex hormone-binding globulin, free androgen index (FAI), carotid stiffness index, intima media thickness, flow-mediated dilatation (FMD) of the brachial artery and non-alcoholic fatty liver disease (NAFLD) were assessed. In women with PCOS, we observed a higher frequency of NAFLD (73.3 vs. 46.7%, P < 0.01) and higher FAI (10.4 vs. 6.8%, P < 0.01). We also observed a trend towards increased insulin levels (10.06 ± 6.66 vs. 7.45 ± 5.88 µIU/mL, P = 0.05), decreased QUICKI (0.36 ± 0.06 vs. 0.39 ± 0.07, P = 0.05) and decreased FMD (7.00 ± 3.87 vs. 8.41 ± 3.79%, P = 0.08). No other significant difference was observed. NAFLD is frequent in obese women without any other health condition that could interfere with COC eligibility criteria, especially in those with PCOS. This should be considered when choosing the best contraceptive option. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.

Cross-interference of two model peroxisome proliferators in peroxisomal and estrogenic pathways in brown trout hepatocytes.

PubMed

Madureira, Tânia Vieira; Pinheiro, Ivone; Malhão, Fernanda; Lopes, Célia; Urbatzka, Ralph; Castro, L Filipe C; Rocha, Eduardo

2017-06-01

Peroxisome proliferators cause species-specific effects, which seem to be primarily transduced by peroxisome proliferator-activated receptor alpha (PPARα). Interestingly, PPARα has a close interrelationship with estrogenic signaling, and this latter has already been promptly activated in brown trout primary hepatocytes. Thus, and further exploring this model, we assess here the reactivity of two PPARα agonists in direct peroxisomal routes and, in parallel the cross-interferences in estrogen receptor (ER) mediated paths. To achieve these goals, three independent in vitro studies were performed using single exposures to clofibrate - CLF (50, 500 and 1000μM), Wy-14,643 - Wy (50 and 150μM), GW6471 - GW (1 and 10μM), and mixtures, including PPARα agonist or antagonist plus an ER agonist or antagonist. Endpoints included gene expression analysis of peroxisome/lipidic related genes (encoding apolipoprotein AI - ApoAI, fatty acid binding protein 1 - Fabp1, catalase - Cat, 17 beta-hydroxysteroid dehydrogenase 4 - 17β-HSD4, peroxin 11 alpha - Pex11α, PPARαBb, PPARαBa and urate oxidase - Uox) and those encoding estrogenic targets (ERα, ERβ-1 and vitellogenin A - VtgA). A quantitative morphological approach by using a pre-validated catalase immunofluorescence technique allowed checking possible changes in peroxisomes. Our results show a low responsiveness of trout hepatocytes to model PPARα agonists in direct target receptor pathways. Additionally, we unveiled interferences in estrogenic signaling caused by Wy, leading to an up-regulation VtgA and ERα at 150μM; these effects seem counteracted with a co-exposure to an ER antagonist. The present data stress the potential of this in vitro model for further exploring the physiological/toxicological implications related with this nuclear receptor cross-regulation. Copyright © 2017 Elsevier B.V. All rights reserved.

Interference of a synthetic C18 juvenile hormone with mammalian cells in vitro, I. Effects on growth and morphology.

PubMed

Zielińska, Z M; Laskowska-Bozek, H; Jastreboff, P

1978-01-01

Some of structural and functional analogs of juvenile hormones are now under field examinations as growth inhibitors of some pest-insect populations. So far however very little is known about the possible interference of these compounds with mammalian cells or organisms. In this research the interference of a synthetic preparation of the insect C18 juvenile hormone with mouse embryo fibroblasts (ME-cells) and mouse cells of an established line (L-cells) was studied. Aliquots of juvenile hormone solution or those of the solvent (DMSO plus ethanol, 9:1) were included into the culture medium and after defined times of contact the cells were tested for their morphology, pattern of growth, proliferation rate and viability. The data for the parameters under examination were evaluated by means of the analysis of variance and checked by the Tuckey test. The sensitivity of ME-cells and L-cells to the agent tested was compared by means of the analysis of variance of the data for mitotic indices of these cells and by evaluation of the number of dead cells in cultures under the particular conditions of the experiments. The main findings can be summarized as follows: 1. Cells of both types are evidently more sensitive to juvenile hormone than to the solvent. 2. ME-cells are more sensitive to both agents than are L-cells. 3. The concentrations of the hormone in the medium required to evoked the cytocidal effect on the mouse cells similarly as those affecting some insect non-target cells were far above concentrations found in insect blood, but they were of the same order of magnitude as those used in physiological experiments with insect organs in vitro.

Laboratory experiments of relevance to the space station environment

NASA Technical Reports Server (NTRS)

Caledonia, G. E.

1988-01-01

It has been found that the interaction between orbital vehicles and the ambient environment produces a contaminant cloud which can cause deletrious effects to spacecraft materials and equipment, create increased radiative backgrounds that would interfere with observational instrumentation, and enhance surface charging. A brief overview of the phenomena that produce the contaminant cloud is presented along with a review of physical data required to characterize it. Laboratory techniques which can be utilized to provide the required data are described. In particular, several oxygen beam apparati are discussed.

Image plane detector spectrophotometer - Application to O2 atmospheric band nightglow

NASA Technical Reports Server (NTRS)

Luo, Mingzhao; Yee, Jeng-Hwa; Hays, Paul B.

1988-01-01

A new variety of low resolution spectrometer is described. This device, an image plane detector spectrophotometer, has high sensitivity and modest resolution sufficient to determine the rotational temperature and brightness of molecular band emissions. It uses an interference filter as a dispersive element and a multichannel image plane detector as the photon collecting device. The data analysis technqiue used to recover the temperature of the emitter and the emission brightness is presented. The atmospheric band of molecular oxygen is used to illustrate the use of the device.

Electrochemical control of iodine disinfectant for space transportation system and space station potable water

NASA Technical Reports Server (NTRS)

Geer, Richard D.

1989-01-01

An electrochemical microbial check valve method (EC-MCV) for controlling the iodine disinfectant in potable water (PW) for NASA's space operations was proposed. The factors affecting the design and performance of the unit were analyzed. This showed that it would be feasible to construct a recyclable unit in a small volume that will operate in either an iodine removal or addition mode. The EC-MCV should remove active iodine species rapidly from PW, but the rapid delivery rates at end-use may make complete removal of excess I(-) difficult under some conditions. Its performace change with AgI buildup needs to be investigated, as this controls the time for recycling the unit. The EC-MCV has advantages over the passive microbial check valve (MCV) method currently in use, as it would allow precise control of the I2 level and would not introduce excess I(-) to the water. The presence of oxygen in the EC-MCV needs to be investigated as it could affect the efficiency of I2 addition and excess I(-) removal.

Phosphate interference during in situ treatment for arsenic in groundwater.

PubMed

Brunsting, Joseph H; McBean, Edward A

2014-01-01

Contamination of groundwater by arsenic is a problem in many areas of the world, particularly in West Bengal (India) and Bangladesh, where reducing conditions in groundwater are the cause. In situ treatment is a novel approach wherein, by introduction of dissolved oxygen (DO), advantages over other treatment methods can be achieved through simplicity, not using chemicals, and not requiring disposal of arsenic-rich wastes. A lab-scale test of in situ treatment by air sparging, using a solution with approximately 5.3 mg L(-1) ferrous iron and 200 μg L(-1) arsenate, showed removal of arsenate in the range of 59%. A significant obstacle exists, however, due to the interference of phosphate since phosphate competes for adsorption sites on oxidized iron precipitates. A lab-scale test including 0.5 mg L(-1) phosphate showed negligible removal of arsenate. In situ treatment by air sparging demonstrates considerable promise for removal of arsenic from groundwater where iron is present in considerable quantities and phosphates are low.

Determination of toxic elements in yerba mate by ICP-MS after diluted acid digestion under O2 pressure.

PubMed

Pardinho, Renan B; Dalla Vecchia, Paula; Mendes, Ana L G; Bizzi, Cezar A; Mello, Paola A; Duarte, Fabio A; Flores, Erico M M

2018-10-15

In this work, a procedure allowing effective digestion of a high mass of yerba mate (up to 1500 mg) using diluted HNO 3, in a system pressurized with oxygen, is proposed. Digests were suitable for direct analysis by ICP-MS, virtually free of interferences. Digestion was performed using 7 mol l -1 HNO 3 and 8 bar O 2 . The digestion efficiency was better than 92% and digests presented a relatively low acidity (<10 mmol HNO 3 ). The limit of quantification was 4.0, 1.0 and 1.0 ng g -1 for As, Cd and Pb, respectively. Under optimized conditions up to 1500 mg of sample were digested and no interferences were observed during analyses by ICP-MS, making this approach suitable for routine determination of As, Cd and Pb in yerba mate and also in agreement with the quality control requirements. Copyright © 2018 Elsevier Ltd. All rights reserved.

Robust statistical methods for hit selection in RNA interference high-throughput screening experiments.

PubMed

Zhang, Xiaohua Douglas; Yang, Xiting Cindy; Chung, Namjin; Gates, Adam; Stec, Erica; Kunapuli, Priya; Holder, Dan J; Ferrer, Marc; Espeseth, Amy S

2006-04-01

RNA interference (RNAi) high-throughput screening (HTS) experiments carried out using large (>5000 short interfering [si]RNA) libraries generate a huge amount of data. In order to use these data to identify the most effective siRNAs tested, it is critical to adopt and develop appropriate statistical methods. To address the questions in hit selection of RNAi HTS, we proposed a quartile-based method which is robust to outliers, true hits and nonsymmetrical data. We compared it with the more traditional tests, mean +/- k standard deviation (SD) and median +/- 3 median of absolute deviation (MAD). The results suggested that the quartile-based method selected more hits than mean +/- k SD under the same preset error rate. The number of hits selected by median +/- k MAD was close to that by the quartile-based method. Further analysis suggested that the quartile-based method had the greatest power in detecting true hits, especially weak or moderate true hits. Our investigation also suggested that platewise analysis (determining effective siRNAs on a plate-by-plate basis) can adjust for systematic errors in different plates, while an experimentwise analysis, in which effective siRNAs are identified in an analysis of the entire experiment, cannot. However, experimentwise analysis may detect a cluster of true positive hits placed together in one or several plates, while platewise analysis may not. To display hit selection results, we designed a specific figure called a plate-well series plot. We thus suggest the following strategy for hit selection in RNAi HTS experiments. First, choose the quartile-based method, or median +/- k MAD, for identifying effective siRNAs. Second, perform the chosen method experimentwise on transformed/normalized data, such as percentage inhibition, to check the possibility of hit clusters. If a cluster of selected hits are observed, repeat the analysis based on untransformed data to determine whether the cluster is due to an artifact in the data. If no clusters of hits are observed, select hits by performing platewise analysis on transformed data. Third, adopt the plate-well series plot to visualize both the data and the hit selection results, as well as to check for artifacts.

Misalignment of disposable pulse oximeter probes results in false saturation readings that influence anesthetic management.

PubMed

Guan, Zhonghui; Baker, Keith; Sandberg, Warren S

2009-11-01

We report a small case series in which misaligned disposable pulse oximeter sensors gave falsely low saturation readings. In each instance, the sensor performed well during preinduction oxygen administration and the early part of the case, most notably by producing a plethysmographic trace rated as high quality by the oximeter software. The reported pulse oximeter oxygen saturation eventually decreased to concerning levels in each instance, but the anesthesiologists, relying on the reported high-quality signal, initially sought other causes for apparent hypoxia. They undertook maneuvers and diagnostic procedures later deemed unnecessary. When the malpositioned sensors were discovered and repositioned, the apparent hypoxia was quickly relieved in each case. We then undertook a survey of disposable oximeter sensors as patients entered the recovery room, and discovered malposition of more than 1 cm in approximately 20% of all sensors, without apparent consequence. We conclude that the technology is quite robust, but that the diagnosis of apparent hypoxia should include a quick check of oximeter position early on.

Microbial Community Composition in a Simultaneous Nitrification and Denitrification Bioreactor for Domestic Wastewater Treatment

NASA Astrophysics Data System (ADS)

Chen, Chen; Ouyang, Wukun; Huang, Shan; Peng, Xiaochun

2018-01-01

Traditional domestic wastewater treatments rely on aerobic processes followed by anaerobic processes. The aerobic step in which ammonium and organic carbon are oxidized, calls for large oxygen input, while the anaerobic process often requires extra carbon input. The challenge of synchronizing both processes is to maintain an active nitrifiers sludge under low dissolved oxygen (DO) condition. In this study, a membrane bioreactor was established and operated stable with low DO of 0.1-0.4 mg L-1. Chemical indicators were determined daily, and bacterial community was checked by qPCR and 16S rDNA sequencing every month. After 2 months incubation, the bioreactor reached to a stable removal rate of total nitrogen around 50% and total organic carbon around 90% with the retaining time of 12 h. The sludge showed enrichment of low DO nitrifiers (Nitrosomonadaceae, Chitinophagaceae, and Nitrospiraceae) which were different from sludge in other regular wastewater treatment plants with aerobic and anaerobic cycles.

Self-propagated combustion synthesis of few-layered graphene: an optical properties perspective.

PubMed

Mohandoss, Manonmani; Sen Gupta, Soujit; Kumar, Ramesh; Islam, Md Rabiul; Som, Anirban; Mohd, Azhardin Ganayee; Pradeep, T; Maliyekkal, Shihabudheen M

2018-04-26

This paper describes a labour efficient and cost-effective strategy to prepare few-layered of reduced graphene oxide like (RGOL) sheets from graphite. The self-propagated combustion route enables the bulk production of RGOL sheets. Microscopic and spectroscopic analyses confirmed the formation of few-layer graphene sheets of an average thickness of ∼3 nm and the presence of some oxygen functional groups with a C/O ratio of 8.74. A possible mechanistic pathway for the formation of RGOL sheets is proposed. The optical properties of the RGOL sample were studied in detail by means of Spectroscopic Ellipsometry (SE). The experimental abilities of SE in relating the optical properties with the number of oxygen functionalities present in the samples are explored. The data were analysed by a double-layered optical model along with the Drude-Lorentz oscillatory dispersion relation. The refractive index (n = 2.24), extinction coefficient (k = 2.03), and dielectric functions are obtained using point-by-point analysis and are also checked for Kramers-Kronig (KK) consistency.

High-precision measurement of (186)Os/(188)Os and (187)Os/(188)Os: isobaric oxide corrections with in-run measured oxygen isotope ratios.

PubMed

Chu, Zhu-Yin; Li, Chao-Feng; Chen, Zhi; Xu, Jun-Jie; Di, Yan-Kun; Guo, Jing-Hui

2015-09-01

We present a novel method for high precision measurement of (186)Os/(188)Os and (187)Os/(188)Os ratios, applying isobaric oxide interference correction based on in-run measurements of oxygen isotopic ratios. For this purpose, we set up a static data collection routine to measure the main Os(16)O3(-) ion beams with Faraday cups connected to conventional 10(11) amplifiers, and (192)Os(16)O2(17)O(-) and (192)Os(16)O2(18)O(-) ion beams with Faraday cups connected to 10(12) amplifiers. Because of the limited number of Faraday cups, we did not measure (184)Os(16)O3(-) and (189)Os(16)O3(-) simultaneously in-run, but the analytical setup had no significant influence on final (186)Os/(188)Os and (187)Os/(188)Os data. By analyzing UMd, DROsS, an in-house Os solution standard, and several rock reference materials, including WPR-1, WMS-1a, and Gpt-5, the in-run measured oxygen isotopic ratios were proven to present accurate Os isotopic data. However, (186)Os/(188)Os and (187)Os/(188)Os data obtained with in-run O isotopic compositions for the solution standards and rock reference materials show minimal improvement in internal and external precision, compared to the conventional oxygen correction method. We concluded that, the small variations of oxygen isotopes during OsO3(-) analytical sessions are probably not the main source of error for high precision Os isotopic analysis. Nevertheless, use of run-specific O isotopic compositions is still a better choice for Os isotopic data reduction and eliminates the requirement of extra measurements of the oxygen isotopic ratios.

Nitric oxide inhibits succinate dehydrogenase-driven oxygen consumption in potato tuber mitochondria in an oxygen tension-independent manner.

PubMed

Simonin, Vagner; Galina, Antonio

2013-01-01

NO (nitric oxide) is described as an inhibitor of plant and mammalian respiratory chains owing to its high affinity for COX (cytochrome c oxidase), which hinders the reduction of oxygen to water. In the present study we show that in plant mitochondria NO may interfere with other respiratory complexes as well. We analysed oxygen consumption supported by complex I and/or complex II and/or external NADH dehydrogenase in Percoll-isolated potato tuber (Solanum tuberosum) mitochondria. When mitochondrial respiration was stimulated by succinate, adding the NO donors SNAP (S-nitroso-N-acetyl-DL-penicillamine) or DETA-NONOate caused a 70% reduction in oxygen consumption rate in state 3 (stimulated with 1 mM of ADP). This inhibition was followed by a significant increase in the Km value of SDH (succinate dehydrogenase) for succinate (Km of 0.77±0.19 to 34.3±5.9 mM, in the presence of NO). When mitochondrial respiration was stimulated by external NADH dehydrogenase or complex I, NO had no effect on respiration. NO itself and DETA-NONOate had similar effects to SNAP. No significant inhibition of respiration was observed in the absence of ADP. More importantly, SNAP inhibited PTM (potato tuber mitochondria) respiration independently of oxygen tensions, indicating a different kinetic mechanism from that observed in mammalian mitochondria. We also observed, in an FAD reduction assay, that SNAP blocked the intrinsic SDH electron flow in much the same way as TTFA (thenoyltrifluoroacetone), a non-competitive SDH inhibitor. We suggest that NO inhibits SDH in its ubiquinone site or its Fe-S centres. These data indicate that SDH has an alternative site of NO action in plant mitochondria.

Analytical and pre-analytical performance characteristics of a novel cartridge-type blood gas analyzer for point-of-care and laboratory testing.

PubMed

Oyaert, Matthijs; Van Maerken, Tom; Bridts, Silke; Van Loon, Silvi; Laverge, Heleen; Stove, Veronique

2018-03-01

Point-of-care blood gas test results may benefit therapeutic decision making by their immediate impact on patient care. We evaluated the (pre-)analytical performance of a novel cartridge-type blood gas analyzer, the GEM Premier 5000 (Werfen), for the determination of pH, partial carbon dioxide pressure (pCO 2 ), partial oxygen pressure (pO 2 ), sodium (Na + ), potassium (K + ), chloride (Cl - ), ionized calcium ( i Ca 2+ ), glucose, lactate, and total hemoglobin (tHb). Total imprecision was estimated according to the CLSI EP5-A2 protocol. The estimated total error was calculated based on the mean of the range claimed by the manufacturer. Based on the CLSI EP9-A2 evaluation protocol, a method comparison with the Siemens RapidPoint 500 and Abbott i-STAT CG8+ was performed. Obtained data were compared against preset quality specifications. Interference of potential pre-analytical confounders on co-oximetry and electrolyte concentrations were studied. The analytical performance was acceptable for all parameters tested. Method comparison demonstrated good agreement to the RapidPoint 500 and i-STAT CG8+, except for some parameters (RapidPoint 500: pCO 2 , K + , lactate and tHb; i-STAT CG8+: pO 2 , Na + , i Ca 2+ and tHb) for which significant differences between analyzers were recorded. No interference of lipemia or methylene blue on CO-oximetry results was found. On the contrary, significant interference for benzalkonium and hemolysis on electrolyte measurements were found, for which the user is notified by an interferent specific flag. Identification of sample errors from pre-analytical sources, such as interferences and automatic corrective actions, along with the analytical performance, ease of use and low maintenance time of the instrument, makes the evaluated instrument a suitable blood gas analyzer for both POCT and laboratory use. Copyright © 2018 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

[Influence of nail polish on pulse oximeter readings of oxygen saturation: a systematic review].

PubMed

Ballesteros-Peña, Sendoa; Fernández-Aedo, Irrintzi; Picón, Artzai; Lorrio-Palomino, Sergio

2015-10-01

Nail polish has traditionally been assumed to absorb light emitted by pulse oximeters and to interfere with the detection and measurement of oxygenated hemoglobin. In a systematic review of the literature we aimed to assess the influence of nail polish on the measurement of oxygen saturation by pulse oximetry (SpO2). A search protocol for online databases (MEDLINE, Embase, Web of Science, Scopus, Cumulative Index to Nursing and Allied Health Literature, and IBECS [the Spanish health sciences index]) was established to find clinical trials or observational studies published between 1999 and February 2014. Twelve nonrandomized clinical trials were found. Ten were in healthy volunteers. One of the remaining 2 studies was in critical patients undergoing mechanical ventilation, and the other was in patients with stable chronic obstructive pulmonary disease. One study recreated the low oxygen level of high altitudes, while the others were done in normal atmospheric conditions. Differences between pulse oximeters and type of nail polish were found. Nail polish was associated with a statistically significant decrease in SpO2 for at least 1 color in all but 2 studies. However, the differences were within the standard error (±2.0%) of the pulse oximeters used. The authors of the studies all concluded that although nail polish might change SpO2 readings significantly, the variations are not clinically significant.

Multiple-wavelength spectroscopic quantitation of light-absorbing species in scattering media

DOEpatents

Nathel, Howard; Cartland, Harry E.; Colston, Jr., Billy W.; Everett, Matthew J.; Roe, Jeffery N.

2000-01-01

An oxygen concentration measurement system for blood hemoglobin comprises a multiple-wavelength low-coherence optical light source that is coupled by single mode fibers through a splitter and combiner and focused on both a target tissue sample and a reference mirror. Reflections from both the reference mirror and from the depths of the target tissue sample are carried back and mixed to produce interference fringes in the splitter and combiner. The reference mirror is set such that the distance traversed in the reference path is the same as the distance traversed into and back from the target tissue sample at some depth in the sample that will provide light attenuation information that is dependent on the oxygen in blood hemoglobin in the target tissue sample. Two wavelengths of light are used to obtain concentrations. The method can be used to measure total hemoglobin concentration [Hb.sub.deoxy +Hb.sub.oxy ] or total blood volume in tissue and in conjunction with oxygen saturation measurements from pulse oximetry can be used to absolutely quantify oxyhemoglobin [HbO.sub.2 ] in tissue. The apparatus and method provide a general means for absolute quantitation of an absorber dispersed in a highly scattering medium.

Comparison of Meteorological Data and Stable Isotope Time Series from an Indonesian Stalagmite

NASA Astrophysics Data System (ADS)

Watanabe, Y.; Matsuoka, H.; Sakai, S.; Ueda, J.; Yamada, M.; Ohsawa, S.; Kiguchi, M.; Satomura, T.; Nakai, S.; Brahmantyo, B.; Maryunani, K. A.; Tagami, T.; Takemura, K.; Yoden, S.

2007-12-01

In the last decade, geochemical records in stalagmites have been widely recognized as a powerful tool for the elucidation of paleoclimate/environment of the terrestrial areas. The previous data are mainly reported from middle latitude. However, this study aims at reconstructing past climate variations in the Asian equatorial regions by using oxygen and carbon isotope ratios recorded in Indonesian stalagmites. Especially, we focused on the comparison of meteorological data and stable isotope time series from an Indonesia stalagmite, in order to check whether the geochemistry of stalagmite is influenced by local precipitation. We performed geological surveys in Buniayu limestone caves, Sukabumi, West Java, Indonesia, and collected a series of stalagmites/stalactites and drip water samples. A stalagmite sample was observed using thin sections to identify banding. Moreover, to construct the age model of the stalagmite, we also measured both (1) the number of bands and (2) uranium series disequilibrium ages using the MC-ICP-MS. These data suggest that each layer is annual banding dominantly. Oxygen and carbon isotope ratios were analyzed on the stalagmite for annual time scales. The carbon isotope ratio has a clear correlation with oxygen isotope ratios. Furthermore, the proxy data was compared with meteorological data set in the past 80 years, showing a good correlation between the temporal variation of oxygen/carbon isotope ratios and annual precipitation. These lines of evidence suggest that the isotopic variation is predominantly caused by kinetic mass fractionation driven by the degassing of carbon dioxide in the cave.

De-MA: a web Database for electron Microprobe Analyses to assist EMP lab manager and users

NASA Astrophysics Data System (ADS)

Allaz, J. M.

2012-12-01

Lab managers and users of electron microprobe (EMP) facilities require comprehensive, yet flexible documentation structures, as well as an efficient scheduling mechanism. A single on-line database system for managing reservations, and providing information on standards, quantitative and qualitative setups (element mapping, etc.), and X-ray data has been developed for this purpose. This system is particularly useful in multi-user facilities where experience ranges from beginners to the highly experienced. New users and occasional facility users will find these tools extremely useful in developing and maintaining high quality, reproducible, and efficient analyses. This user-friendly database is available through the web, and uses MySQL as a database and PHP/HTML as script language (dynamic website). The database includes several tables for standards information, X-ray lines, X-ray element mapping, PHA, element setups, and agenda. It is configurable for up to five different EMPs in a single lab, each of them having up to five spectrometers and as many diffraction crystals as required. The installation should be done on a web server supporting PHP/MySQL, although installation on a personal computer is possible using third-party freeware to create a local Apache server, and to enable PHP/MySQL. Since it is web-based, any user outside the EMP lab can access this database anytime through any web browser and on any operating system. The access can be secured using a general password protection (e.g. htaccess). The web interface consists of 6 main menus. (1) "Standards" lists standards defined in the database, and displays detailed information on each (e.g. material type, name, reference, comments, and analyses). Images such as EDS spectra or BSE can be associated with a standard. (2) "Analyses" lists typical setups to use for quantitative analyses, allows calculation of mineral composition based on a mineral formula, or calculation of mineral formula based on a fixed amount of oxygen, or of cation (using an analysis in element or oxide weight-%); this latter includes re-calculation of H2O/CO2 based on stoichiometry, and oxygen correction for F and Cl. Another option offers a list of any available standards and possible peak or background interferences for a series of elements. (3) "X-ray maps" lists the different setups recommended for element mapping using WDS, and a map calculator to facilitate maps setups and to estimate the total mapping time. (4) "X-ray data" lists all x-ray lines for a specific element (K, L, M, absorption edges, and satellite peaks) in term of energy, wavelength and peak position. A check for possible interferences on peak or background is also possible. Theoretical x-ray peak positions for each crystal are calculated based on the 2d spacing of each crystal and the wavelength of each line. (5) "Agenda" menu displays the reservation dates for each month and for each EMP lab defined. It also offers a reservation request option, this request being sent by email to the EMP manager for approval. (6) Finally, "Admin" is password restricted, and contains all necessary options to manage the database through user-friendly forms. The installation of this database is made easy and knowledge of HTML, PHP, or MySQL is unnecessary to install, configure, manage, or use it. A working database is accessible at http://cub.geoloweb.ch.

Indirect Phase Height Measurements in Central and Eastern Europe for Monitoring D Region Plasma

NASA Technical Reports Server (NTRS)

Cossart, G. V.; Pakhomov, S. V.

1984-01-01

Low-frequency propagation experiments for the investigation of the lower part of the ionospheric D region were at first used by BRACEWELL et al. (1951) in the early fifties. Among these was the method of indirect phase height measurements for continuous monitoring of the lower ionosphere. It is based upon field strength measurements of commercial radio transmitters in the frequency range between 50 and 200 kHz at distances from 500 to 1500 km. The field strength records show characteristic diurnal variations with maxima and minima, produced by interference between the ground wave and the ionospherically reflected sky wave, the phase difference between varies in correspondence to the diurnal variation of the reflection height. In order to check the validity of interpretations of indirect phase height data, comparisons were made with simultaneous rocket soundings. Results are summarized.

Noise from propellers with symmetrical sections at zero blade angle, II

NASA Technical Reports Server (NTRS)

Deming, A F

1938-01-01

In a previous paper (Technical Note No. 605), a theory was developed that required an empirical relation to calculate sound pressures for the higher harmonics. Further investigation indicated that the modified theory agrees with experiment and that the empirical relation was due to an interference phenomenon peculiar to the test arrangement used. Comparison is made between the test results for a two-blade arrangement and the theory. The comparison is made for sound pressures in the plane of the revolving blades for varying values of tip velocity. Comparison is also made at constant tip velocity for all values of azimuth angle B. A further check is made between the theory and the experimental results for the fundamental of a four-blade arrangement with blades of the same dimensions as those used in the two-blade arrangement.

Rapid analysis of hyperbaric oxygen therapy registry data for reimbursement purposes: Technical communication.

PubMed

Fife, Caroline E; Gelly, Helen; Walker, David; Eckert, Kristen Allison

2016-01-01

To explain how Hyperbaric Oxygen Therapy Registry (HBOTR) data of the US Wound Registry (USWR) helped establish a fair analysis of the physician work of hyperbaric chamber supervision for reimbursement purposes. We queried HBOTR data from January 1, 2013, to December 31, 2013, on patient comorbidities and medications as well as the number of hyperbaric oxygen (HBO₂) therapy treatments supervised per physician per day from all hyperbaric facilities participating in the USWR that had been using the electronic medical record (EHR) for more than six months and had passed data completeness checks. Among 11,240 patients at the 87 facilities included, the mean number of comorbidities and medications was 10 and 12, respectively. The mean number of HBO₂ treatments supervised per physician per day was 3.7 at monoplace facilities and 5.4 at multiplace facilities. Following analysis of these data by the RUC, the reimbursement rate of chamber supervision was decreased to $112.06. Patients undergoing HBO₂ therapy generally suffer from multiple, serious comorbidities and require multiple medications, which increase the risk of HBO₂ and necessitate the presence of a properly trained hyperbaric physician. The lack of engagement by hyperbaric physicians in registry reporting may result in lack of adequate data being available to counter future challenges to reimbursement.

Interference of flavonoids with fluorescent intracellular probes: methodological implications in the evaluation of the oxidative burst by flow cytometry.

PubMed

Peluso, Ilaria; Manafikhi, Husseen; Reggi, Raffaella; Palmery, Maura

2014-08-01

The evaluation of oxidative burst is particularly relevant in many pathological and subclinical conditions. Flow cytometry provides quick and accurate measures of the reactive oxygen species production by leukocytes in most situations. However, spurious results, related to probes' efflux may be observed in several instances. Many factors affect the evaluation of the oxidative burst with fluorescent probes that require intracellular deacetylation and could be substrate of the multidrug resistance proteins (MDR). After discussing the implications of the efflux of fluorophores in the normalization strategies in flow cytometry assays, we have pointed out the possible interference of flavonoids with fluorescet probes' staining and signal. We have also reviewed the results from human intervention studies regarding the evaluation of oxidative burst with these probes. In vitro, at concentrations close to post-ingestion circulating levels, some flavonoids and their metabolites could interfere with probes' staining and fluorescence signal through different mechanisms, such as the inhibition of esterases, the modulation of the MDR-mediate efflux of probe and the inhibition of the oxidation of probe. These effects may explain the contrasting results obtained by human intervention studies. Finally, also inflammatory state or the use of drugs substrate of MDR proteins could affect the evaluation of the oxidative burst with intracellular probes. © 2014 International Society for Advancement of Cytometry.

Effect of Routine Low-Dose Oxygen Supplementation on Death and Disability in Adults With Acute Stroke: The Stroke Oxygen Study Randomized Clinical Trial.

PubMed

Roffe, Christine; Nevatte, Tracy; Sim, Julius; Bishop, Jon; Ives, Natalie; Ferdinand, Phillip; Gray, Richard

2017-09-26

Hypoxia is common in the first few days after acute stroke, is frequently intermittent, and is often undetected. Oxygen supplementation could prevent hypoxia and secondary neurological deterioration and thus has the potential to improve recovery. To assess whether routine prophylactic low-dose oxygen therapy was more effective than control oxygen administration in reducing death and disability at 90 days, and if so, whether oxygen given at night only, when hypoxia is most frequent, and oxygen administration is least likely to interfere with rehabilitation, was more effective than continuous supplementation. In this single-blind randomized clinical trial, 8003 adults with acute stroke were enrolled from 136 participating centers in the United Kingdom within 24 hours of hospital admission if they had no clear indications for or contraindications to oxygen treatment (first patient enrolled April 24, 2008; last follow-up January 27, 2015). Participants were randomized 1:1:1 to continuous oxygen for 72 hours (n = 2668), nocturnal oxygen (21:00 to 07:00 hours) for 3 nights (n = 2667), or control (oxygen only if clinically indicated; n = 2668). Oxygen was given via nasal tubes at 3 L/min if baseline oxygen saturation was 93% or less and at 2 L/min if oxygen saturation was greater than 93%. The primary outcome was reported using the modified Rankin Scale score (disability range, 0 [no symptoms] to 6 [death]; minimum clinically important difference, 1 point), assessed at 90 days by postal questionnaire (participant aware, assessor blinded). The modified Rankin Scale score was analyzed by ordinal logistic regression, which yields a common odds ratio (OR) for a change from one disability level to the next better (lower) level; OR greater than 1.00 indicates improvement. A total of 8003 patients (4398 (55%) men; mean [SD] age, 72 [13] years; median National Institutes of Health Stroke Scale score, 5; mean baseline oxygen saturation, 96.6%) were enrolled. The primary outcome was available for 7677 (96%) participants. The unadjusted OR for a better outcome (calculated via ordinal logistic regression) was 0.97 (95% CI, 0.89 to 1.05; P = .47) for oxygen vs control, and the OR was 1.03 (95% CI, 0.93 to 1.13; P = .61) for continuous vs nocturnal oxygen. No subgroup could be identified that benefited from oxygen. At least 1 serious adverse event occurred in 348 (13.0%) participants in the continuous oxygen group, 294 (11.0%) in the nocturnal group, and 322 (12.1%) in the control group. No significant harms were identified. Among nonhypoxic patients with acute stroke, the prophylactic use of low-dose oxygen supplementation did not reduce death or disability at 3 months. These findings do not support low-dose oxygen in this setting. ISRCTN Identifier: ISRCTN52416964.

Factors interfering with the accuracy of five blood glucose meters used in Chinese hospitals.

PubMed

Lv, Hong; Zhang, Guo-jun; Kang, Xi-xiong; Yuan, Hui; Lv, Yan-wei; Wang, Wen-wen; Randall, Rollins

2013-09-01

The prevalence of diabetes is increasing in China. Glucose control is very important in diabetic patients. The aim of this study was to compare the accuracy of five glucose meters used in Chinese hospitals with a reference method, in the absence and presence of various factors that may interfere with the meters. Within-run precision of the meters was evaluated include Roche Accu-Chek Inform®, Abbott Precision PCx FreeStyle®, Bayer Contour®, J&J LifeScan SureStep Flexx®, and Nova Biomedical StatStrip®. The interference of hematocrit level, maltose, ascorbic acid, acetaminophen, galactose, dopamine, and uric acid were tested in three levels of blood glucose, namely low, medium, and high concentrations. Accuracy (bias) of the meters and analytical interference by various factors were evaluated by comparing results obtained in whole blood specimens with those in plasma samples of the whole blood specimens run on the reference method. Impact of oxygen tension on above five blood glucose meters was detected. Precision was acceptable and slightly different between meters. There were no significant differences in the measurements between the meters and the reference method. The hematocrit level significantly interfered with all meters, except StatStrip. Measurements were affected to varying degrees by different substances at different glucose levels, e.g. acetaminophen and ascorbic acid (Freestyle), maltose and galactose (FreeStyle, Accu-Chek), uric acid (FreeStyle, Bayer Contour), and dopamine (Bayer Contour). The measurements with the five meters showed a good correlation with the plasma hexokinase reference method, but most were affected by the hematocrit level. Some meters also showed marked interference by other substances. © 2013 Wiley Periodicals, Inc.

Development and Testing of Iron Based Phantoms as Standards for the Diagnosis of Microbleeds and Oxygen Saturation with Applications in Dementia, Stroke, and Traumatic Brain Injury

DTIC Science & Technology

2013-10-01

be important for the MRI community to be aware of these unexpected findings. We are trying to understand the causes. As a comparison, we have also...R2 estimations. However, if R2 or R2* is large, then it is also important to check whether the signal-to-noise ratio (SNR) is at least 3:1 in images...Some results are listed in Table 10. All these findings are important knowledge to the MRI community. Conc (mg/L)  (ppm) Straw 1 25.70 1.28

Effect of Routine Low-Dose Oxygen Supplementation on Death and Disability in Adults With Acute Stroke

PubMed Central

Nevatte, Tracy; Sim, Julius; Bishop, Jon; Ives, Natalie; Ferdinand, Phillip; Gray, Richard

2017-01-01

Importance Hypoxia is common in the first few days after acute stroke, is frequently intermittent, and is often undetected. Oxygen supplementation could prevent hypoxia and secondary neurological deterioration and thus has the potential to improve recovery. Objective To assess whether routine prophylactic low-dose oxygen therapy was more effective than control oxygen administration in reducing death and disability at 90 days, and if so, whether oxygen given at night only, when hypoxia is most frequent, and oxygen administration is least likely to interfere with rehabilitation, was more effective than continuous supplementation. Design, Setting, and Participants In this single-blind randomized clinical trial, 8003 adults with acute stroke were enrolled from 136 participating centers in the United Kingdom within 24 hours of hospital admission if they had no clear indications for or contraindications to oxygen treatment (first patient enrolled April 24, 2008; last follow-up January 27, 2015). Interventions Participants were randomized 1:1:1 to continuous oxygen for 72 hours (n = 2668), nocturnal oxygen (21:00 to 07:00 hours) for 3 nights (n = 2667), or control (oxygen only if clinically indicated; n = 2668). Oxygen was given via nasal tubes at 3 L/min if baseline oxygen saturation was 93% or less and at 2 L/min if oxygen saturation was greater than 93%. Main Outcomes and Measures The primary outcome was reported using the modified Rankin Scale score (disability range, 0 [no symptoms] to 6 [death]; minimum clinically important difference, 1 point), assessed at 90 days by postal questionnaire (participant aware, assessor blinded). The modified Rankin Scale score was analyzed by ordinal logistic regression, which yields a common odds ratio (OR) for a change from one disability level to the next better (lower) level; OR greater than 1.00 indicates improvement. Results A total of 8003 patients (4398 (55%) men; mean [SD] age, 72 [13] years; median National Institutes of Health Stroke Scale score, 5; mean baseline oxygen saturation, 96.6%) were enrolled. The primary outcome was available for 7677 (96%) participants. The unadjusted OR for a better outcome (calculated via ordinal logistic regression) was 0.97 (95% CI, 0.89 to 1.05; P = .47) for oxygen vs control, and the OR was 1.03 (95% CI, 0.93 to 1.13; P = .61) for continuous vs nocturnal oxygen. No subgroup could be identified that benefited from oxygen. At least 1 serious adverse event occurred in 348 (13.0%) participants in the continuous oxygen group, 294 (11.0%) in the nocturnal group, and 322 (12.1%) in the control group. No significant harms were identified. Conclusions and Relevance Among nonhypoxic patients with acute stroke, the prophylactic use of low-dose oxygen supplementation did not reduce death or disability at 3 months. These findings do not support low-dose oxygen in this setting. Trial Registration ISRCTN Identifier: ISRCTN52416964 PMID:28973619

Testing Accuracy of Long-Range Ultrasonic Sensors for Olive Tree Canopy Measurements

PubMed Central

Gamarra-Diezma, Juan Luis; Miranda-Fuentes, Antonio; Llorens, Jordi; Cuenca, Andrés; Blanco-Roldán, Gregorio L.; Rodríguez-Lizana, Antonio

2015-01-01

Ultrasonic sensors are often used to adjust spray volume by allowing the calculation of the crown volume of tree crops. The special conditions of the olive tree require the use of long-range sensors, which are less accurate and faster than the most commonly used sensors. The main objectives of the study were to determine the suitability of the sensor in terms of sound cone determination, angle errors, crosstalk errors and field measurements. Different laboratory tests were performed to check the suitability of a commercial long-range ultrasonic sensor, as were the experimental determination of the sound cone diameter at several distances for several target materials, the determination of the influence of the angle of incidence of the sound wave on the target and distance on the accuracy of measurements for several materials and the determination of the importance of the errors due to interference between sensors for different sensor spacings and distances for two different materials. Furthermore, sensor accuracy was tested under real field conditions. The results show that the studied sensor is appropriate for olive trees because the sound cone is narrower for an olive tree than for the other studied materials, the olive tree canopy does not have a large influence on the sensor accuracy with respect to distance and angle, the interference errors are insignificant for high sensor spacings and the sensor's field distance measurements were deemed sufficiently accurate. PMID:25635414

Sets of spectral lines for spectrographic thermometry and manometry in d.c. arcs of geologic materials

USGS Publications Warehouse

Golightly, D.W.; Dorrzapf, A.F.; Thomas, C.P.

1977-01-01

Sets of 5 Fe(I) lines and 3 Ti(I)Ti(II) line pairs have been characterized for precise spectrographic thermometry and manometry, respectively, in d.c. arcs of geologic materials. The recommended lines are free of spectral interferences, exhibit minimal self absorption within defined concentration intervals, and are useful for chemically-unaltered silicate rocks, arced in an argon-oxygen stream. The functional character of these lines in thermometry and manometry of d.c. arcs for evaluations of electrical parameter effects, for temporal studies, and for matrix-effect investigations on real samples is illustrated. ?? 1977.

Mapping the local reaction kinetics by PEEM: CO oxidation on individual (100)-type grains of Pt foil

PubMed Central

Vogel, D.; Spiel, C.; Suchorski, Y.; Urich, A.; Schlögl, R.; Rupprechter, G.

2011-01-01

The locally-resolved reaction kinetics of CO oxidation on individual (100)-type grains of a polycrystalline Pt foil was monitored in situ using photoemission electron microscopy (PEEM). Reaction-induced surface morphology changes were studied by optical differential interference contrast microscopy and atomic force microscopy (AFM). Regions of high catalytic activity, low activity and bistability in a (p,T)-parameter space were determined, allowing to establish a local kinetic phase diagram for CO oxidation on (100) facets of Pt foil. PEEM observations of the reaction front propagation on Pt(100) domains reveal a high degree of propagation anisotropy both for oxygen and CO fronts on the apparently isotropic Pt(100) surface. The anisotropy vanishes for oxygen fronts at temperatures above 465 K, but is maintained for CO fronts at all temperatures studied, i.e. in the range of 417 to 513 K. A change in the front propagation mechanism is proposed to explain the observed effects. PMID:22140277

Transcranial oximetry as a new monitoring method for HEMS (Helicopter EMS).

PubMed

Burillo-Putze, Guillermo; Herranz, Ignacio; Pérez, Vicente; Redondo, Faustino; Fernández, Francisco; Jiménez-Sosa, Alejandro; Alvarez, Jesús

2002-01-01

Transcranial oximetry (TCO) is a new method to measure continuous changes in brain blood oxygen saturation (rSO2) by using near-infrared spectroscopy (NIRS). To our knowledge, no studies about TCO in air medical transport have been published. Twenty healthy volunteers (HEMS medical crew) were investigated during flight missions without patients. We measured oxygen saturation (SpO2), cardiac rate, and rSO2 with an INVOS 4100 Cerebral Oximeter at sea level and at each 1000 feet until we reached a flight level of 5000 feet. The oximeter did not produce any interference with medical or aeronautical equipment. Subjects' SpO2 showed a slight decrease with altitude (P < 0.010), but rSO2 remained constant (P = 0.28), with little delay in the physiological correction of SpO2 and rSO2 values. TCO may play an important role in the development of new monitoring methods for critical patients in air medical transport. Further studies with large sample sizes and patients are necessary to generalize findings.

OH and CH luminescence in opposed flow methane oxy-flames

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

De Leo, Maurizio; Saveliev, Alexei; Kennedy, Lawrence A.

Emission spectroscopy is a 2-D nonintrusive diagnostic technique that offers spatially resolved data for combustion optimization and control. The UV and visible chemiluminescence of the excited radicals CH(A{sup 2}{delta},B{sup 2}{sigma}{sup -}) and OH(A{sup 2}{sigma}{sup +}) is studied experimentally and numerically in opposed-flow diffusion flames of methane and oxygen-enriched air. The oxidized oxygen content is varied from 21 to 100% while the range of the studied strain rates spans from 20 to 40 s{sup -1}. The spectrally resolved imaging is obtained by two different methods: scattering through a grating monochromator and interposition of interference filters along the optical path. Absolute measuredmore » chemiluminescence intensities, coupled with a numerical model based on the opposed flow flame code, are used to evaluate the chemical kinetics of the excited species. The predictions of the selected model are in good agreement with the experimental data over the range of the studied flame conditions. (author)« less

Fluorescent in vivo imaging of reactive oxygen species and redox potential in plants.

PubMed

Ortega-Villasante, Cristina; Burén, Stefan; Blázquez-Castro, Alfonso; Barón-Sola, Ángel; Hernández, Luis E

2018-04-05

Reactive oxygen species (ROS) are by-products of aerobic metabolism, and excessive production can result in oxidative stress and cell damage. In addition, ROS function as cellular messengers, working as redox regulators in a multitude of biological processes. Understanding ROS signalling and stress responses requires methods for precise imaging and quantification to monitor local, subcellular and global ROS dynamics with high selectivity, sensitivity and spatiotemporal resolution. In this review, we summarize the present knowledge for in vivo plant ROS imaging and detection, using both chemical probes and fluorescent protein-based biosensors. Certain characteristics of plant tissues, for example high background autofluorescence in photosynthetic organs and the multitude of endogenous antioxidants, can interfere with ROS and redox potential detection, making imaging extra challenging. Novel methods and techniques to measure in vivo plant ROS and redox changes with better selectivity, accuracy, and spatiotemporal resolution are therefore desirable to fully acknowledge the remarkably complex plant ROS signalling networks. Copyright © 2018 Elsevier Inc. All rights reserved.

Martian Atmospheric Dust Mitigation for ISRU Intakes via Electrostatic Precipitation

NASA Technical Reports Server (NTRS)

Phillips, James R., III; Pollard, Jacob R. S.; Johansen, Michael R.; Mackey, Paul J.; Clements, J. Sid; Calle, Carlos I.

2016-01-01

The Mars 2020 and Mars Sample Return missions expected to fly to Mars within the next ten years will each include an In Situ Resource Utilization (ISRU) system. They convert carbon dioxide in the Martian atmosphere into consumable oxygen at 1% and 20% of the rate required by a full scale human exploration Mars mission, respectively. The ISRU systems will need to draw in the surrounding atmosphere at a rate of 110L/min and 550L/min, respectively, in order to meet their oxygen production goals. Over the duration of each respective mission, a total atmospheric dust mass of 4.86g and 243g will be drawn into each system, respectively. Ingestion of large quantities of dust may interfere with ISRU operations, so a dust mitigation device will be required. The atmospheric volume and dust mass flow rates above will be utilized to simulate Martian environmental conditions in a laboratory electrostatic precipitator being developed to provide active dust mitigation support for atmospheric ISRU systems such as these.

Exopolysaccharides from Burkholderia cenocepacia inhibit neutrophil chemotaxis and scavenge reactive oxygen species.

PubMed

Bylund, Johan; Burgess, Lee-Anna; Cescutti, Paola; Ernst, Robert K; Speert, David P

2006-02-03

Bacteria belonging to the Burkholderia cepacia complex are important opportunistic pathogens in compromised hosts, particularly patients with cystic fibrosis or chronic granulomatous disease. Isolates of B. cepacia complex may produce large amounts of exopolysaccharides (EPS) that endow the bacteria with a mucoid phenotype and appear to facilitate bacterial persistence during infection. We showed that EPS from a clinical B. cenocepacia isolate interfered with the function of human neutrophils in vitro; it inhibited chemotaxis and production of reactive oxygen species (ROS), both essential components of innate neutrophil-mediated host defenses. These inhibitory effects were not due to cytotoxicity or interference with intracellular calcium signaling. EPS also inhibited enzymatic generation of ROS in cell-free systems, indicating that it scavenges these bactericidal products. B. cenocepacia EPS is structurally distinct from Pseudomonas aeruginosa alginate, yet they share the capacity to scavenge ROS and inhibit chemotaxis. These properties could explain why the two bacterial species resist clearance from the infected cystic fibrosis lung.

Comparison of femtosecond- and nanosecond-two-photon-absorption laser-induced fluorescence (TALIF) of atomic oxygen in atmospheric-pressure plasmas

NASA Astrophysics Data System (ADS)

Schmidt, Jacob B.; Sands, Brian; Scofield, James; Gord, James R.; Roy, Sukesh

2017-05-01

Absolute number densities of atomic species produced by nanosecond (ns)-duration, repetitively pulsed electric discharges are measured by two-photon-absorption laser-induced fluorescence (TALIF). Unique to this work is the development of femtosecond-laser-based TALIF (fs-TALIF) that offers a number of advantages over more conventional nanosecond (ns)-pulse-duration laser techniques, such as higher-fidelity quenching rate measurements over a wide pressure range, significantly reduced photolytic interference (including photo-dissociation and photo-ionization), ability to collect two-dimensional images of atomic-species number densities with high spatial resolution aided by higher signal level, and efficient and accurate measurements of atomic-species number densities due to the higher repetition rates of the laser. For full quantification of these advantages, atomic-oxygen TALIF signals are collected from an atmospheric-pressure plasma jet employing both ns- and fs-duration laser-excitation pulses and the results are compared and contrasted.

Module for Oxygenating Water without Generating Bubbles

NASA Technical Reports Server (NTRS)

Gonzalez-Martin, Anuncia; Sidik, Reyimjan; Kim, Jinseong

2004-01-01

A module that dissolves oxygen in water at concentrations approaching saturation, without generating bubbles of oxygen gas, has been developed as a prototype of improved oxygenators for water-disinfection and water-purification systems that utilize photocatalyzed redox reactions. Depending on the specific nature of a water-treatment system, it is desirable to prevent the formation of bubbles for one or more reasons: (1) Bubbles can remove some organic contaminants from the liquid phase to the gas phase, thereby introducing a gas-treatment problem that complicates the overall water-treatment problem; and/or (2) in some systems (e.g., those that must function in microgravity or in any orientation in normal Earth gravity), bubbles can interfere with the flow of the liquid phase. The present oxygenation module (see Figure 1) is a modified version of a commercial module that contains >100 hollow polypropylene fibers with a nominal pore size of 0.05 m and a total surface area of 0.5 m2. The module was originally designed for oxygenation in a bioreactor, with no water flowing around or inside the tubes. The modification, made to enable the use of the module to oxygenate flowing water, consisted mainly in the encapsulation of the fibers in a tube of Tygon polyvinyl chloride (PVC) with an inside diameter of 1 in. (approx.=25 mm). In operation, water is pumped along the insides of the hollow fibers and oxygen gas is supplied to the space outside the hollow tubes inside the PVC tube. In tests, the pressure drops of water and oxygen in the module were found to be close to zero at water-flow rates ranging up to 320 mL/min and oxygen-flow rates up to 27 mL/min. Under all test conditions, no bubbles were observed at the water outlet. In some tests, flow rates were chosen to obtain dissolved-oxygen concentrations between 25 and 31 parts per million (ppm) . approaching the saturation level of approx.=35 ppm at a temperature of 20 C and pressure of 1 atm (approx.=0.1 MPa). As one would expect, it was observed that the time needed to bring a flow of water from an initial low dissolved-oxygen concentration (e.g., 5 ppm) to a steady high dissolved-oxygen concentration at or near the saturation level depends on the rates of flow of both oxygen and water, among other things. Figure 2 shows the results of an experiment in which a greater flow of oxygen was used during the first few tens of minutes to bring the concentration up to approx.=25 ppm, then a lesser flow was used to maintain the concentration.

Refractory status epilepticus after inadvertent intrathecal injection of tranexamic acid treated by magnesium sulfate.

PubMed

Hatch, D M; Atito-Narh, E; Herschmiller, E J; Olufolabi, A J; Owen, M D

2016-05-01

We present a case of accidental injection of tranexamic acid during spinal anesthesia for an elective cesarean delivery. Immediately following intrathecal injection of 2mL of solution, the patient complained of severe back pain, followed by muscle spasm and tetany. As there was no evidence of spinal block, the medications given were checked and a 'used' ampoule of tranexamic acid was found on the spinal tray. General anesthesia was induced but muscle spasm and tetany persisted despite administration of a non-depolarizing muscle relaxant. Hemodynamic instability, ventricular tachycardia, and status epilepticus developed, which were refractory to phenytoin, diazepam, and infusions of thiopental, midazolam and amiodarone. Magnesium sulfate was administered postoperatively in the intensive care unit, following which the frequency of seizures decreased, eventually stopping. Unfortunately, on postoperative day three the patient died from cardiopulmonary arrest after an oxygen supply failure that was not associated with the initial event. This report underlines the importance of double-checking medications before injection in order to avoid a drug error. As well, it suggests that magnesium sulfate may be useful in stopping seizures caused by the intrathecal injection of tranexamic acid. Copyright © 2015 Elsevier Ltd. All rights reserved.

A case of a power failure in the operating room.

PubMed

Yasny, Jeffrey; Soffer, Robert

2005-01-01

In the operating room, safely administering anesthesia amidst a major power failure can instantly present one with a formidable challenge. A case is presented involving a 23-year-old healthy woman who underwent a complex oral and maxillofacial surgery to correct a dentofacial deformity. Three hours into the case and with the patient's maxilla downfractured, the overhead surgical lights blacked out, and there was an apparent loss of the anesthesia machine's ability to function. Providing adequate oxygenation, ventilation, anesthesia levels, monitoring of vital signs, and transportation of the patient were some of the challenges faced, and the response to this unexpected event is recounted. The importance of one's familiarity with an anesthesia machine's backup battery supply, routinely checking machinery, ensuring that appropriate and sufficient supplies are readily available, exercising calm leadership with clear communication, and formulating a clear plan with backup alternatives are discussed. Various recommendations are proposed with respect to the preparation for and the prevention of a power failure in the operating room. This report's account of events is aimed to "shed some light" on this topic, serve as a check of one's own preparedness, and facilitate the optimal management of a similarly unexpected incident.

Impaired prefrontal cognitive control over interference by food images in binge-eating disorder and bulimia nervosa.

PubMed

Lee, Jung Eun; Namkoong, Kee; Jung, Young-Chul

2017-06-09

Binge-eating disorder (BED)characterized by recurrent episodes of binge-eating without inappropriate compensatory behaviors is classified as an official diagnosis in DSM-5. However, the neural bases that differentiate BED from other eating disorders such as bulimia nervosa (BN), are still under debate. Thirty-nine participants (HC, n=14; BN, n=13; BED, n=12) underwent functional MRI while performing a Stroop-Match-to-Sample task. This pilot study investigated how food images interfered with the behavioral performances and blood-oxygenation-level-dependent neuronal activity. Compared to healthy controls, participants with BN showed lower accuracy indicating impaired cognitive control over interference. Compared to healthy controls, participants with BED demonstrated stronger activations in the ventral striatum in response to food images. By contrast, participants with BN exhibited stronger activations in the premotor cortex and dorsal striatum. These aberrant ventral and dorsal frontostriatal activations in response to food images are associated with increased reward sensitivity and habitual binge-eating/purging behaviors in BED and BN. Copyright © 2017 Elsevier B.V. All rights reserved.

Menaquinone analogs inhibit growth of bacterial pathogens.

PubMed

Schlievert, Patrick M; Merriman, Joseph A; Salgado-Pabón, Wilmara; Mueller, Elizabeth A; Spaulding, Adam R; Vu, Bao G; Chuang-Smith, Olivia N; Kohler, Petra L; Kirby, John R

2013-11-01

Gram-positive bacteria cause serious human illnesses through combinations of cell surface and secreted virulence factors. We initiated studies with four of these organisms to develop novel topical antibacterial agents that interfere with growth and exotoxin production, focusing on menaquinone analogs. Menadione, 1,4-naphthoquinone, and coenzymes Q1 to Q3 but not menaquinone, phylloquinone, or coenzyme Q10 inhibited the growth and to a greater extent exotoxin production of Staphylococcus aureus, Bacillus anthracis, Streptococcus pyogenes, and Streptococcus agalactiae at concentrations of 10 to 200 μg/ml. Coenzyme Q1 reduced the ability of S. aureus to cause toxic shock syndrome in a rabbit model, inhibited the growth of four Gram-negative bacteria, and synergized with another antimicrobial agent, glycerol monolaurate, to inhibit S. aureus growth. The staphylococcal two-component system SrrA/B was shown to be an antibacterial target of coenzyme Q1. We hypothesize that menaquinone analogs both induce toxic reactive oxygen species and affect bacterial plasma membranes and biosynthetic machinery to interfere with two-component systems, respiration, and macromolecular synthesis. These compounds represent a novel class of potential topical therapeutic agents.

Identification of phosphates involved in catalysis by the ribozyme RNase P RNA.

PubMed Central

Harris, M E; Pace, N R

1995-01-01

The RNA subunit of ribonuclease P (RNase P RNA) is a catalytic RNA that cleaves precursor tRNAs to generate mature tRNA 5' ends. Little is known concerning the identity and arrangement of functional groups that constitute the active site of this ribozyme. We have used an RNase P RNA-substrate conjugate that undergoes rapid, accurate, and efficient self-cleavage in vitro to probe, by phosphorothioate modification-interference, functional groups required for catalysis. We identify four phosphate oxygens where substitution by sulfur significantly reduces the catalytic rate (50-200-fold). Interference at one site was partially rescued in the presence of manganese, suggesting a direct involvement in binding divalent metal ion cofactors required for catalysis. All sites are located in conserved sequence and secondary structure, and positioned adjacent to the substrate phosphate in a tertiary structure model of the ribozyme-substrate complex. The spatial arrangement of phosphorothioate-sensitive sites in RNase P RNA was found to resemble the distribution of analogous positions in the secondary and potential tertiary structures of other large catalytic RNAs. PMID:7585250

Assessment of oxidative stress in serum by d-ROMs test.

PubMed

Kilk, K; Meitern, R; Härmson, O; Soomets, U; Hõrak, P

2014-08-01

Assessment of oxidative stress is an important but technically challenging procedure in medical and biological research. The reactive oxygen metabolites (d-ROMs) test is a simple assay marketed for analyzing the total amount of hydroperoxides in serum via the Fenton's reaction. Earlier reports have raised a suspicion that a part of the signal detected in the assay comes from sources other than metabolites generated by oxidative stress. The aim of this study was to identify which serum components interfere with the d-ROMs signal. By application of sodium azide, ethylenediaminetetraacetic acid, sodium dodecylsulphate, varying temperature, and spiking endogenous substances we demonstrate that in the case of mammalian sera the assay determines ceruloplasmin (CP) activity with potential interferences from hydroperoxides, iron level, thiols, and albumin. In sera of avian species hydroperoxides contribute more to the test outcome, but the CP part is insensitive to inhibition by azide. In conclusion, this assay has deficiencies in terms of detecting realistic concentrations of hydroperoxides, is mostly measuring CP and is also interfered with other serum components, making it very difficult to interpret in most biological systems.

Resveratrol Antagonizes Antimicrobial Lethality and Stimulates Recovery of Bacterial Mutants

PubMed Central

Liu, Yuanli; Zhou, Jinan; Qu, Yilin; Yang, Xinguang; Shi, Guojing; Wang, Xiuhong; Hong, Yuzhi; Drlica, Karl; Zhao, Xilin

2016-01-01

Reactive oxygen species (ROS; superoxide, peroxide, and hydroxyl radical) are thought to contribute to the rapid bactericidal activity of diverse antimicrobial agents. The possibility has been raised that consumption of antioxidants in food may interfere with the lethal action of antimicrobials. Whether nutritional supplements containing antioxidant activity are also likely to interfere with antimicrobial lethality is unknown. To examine this possibility, resveratrol, a popular antioxidant dietary supplement, was added to cultures of Escherichia coli and Staphylococcus aureus that were then treated with antimicrobial and assayed for bacterial survival and the recovery of mutants resistant to an unrelated antimicrobial, rifampicin. Resveratrol, at concentrations likely to be present during human consumption, caused a 2- to 3-fold reduction in killing during a 2-hr treatment with moxifloxacin or kanamycin. At higher, but still subinhibitory concentrations, resveratrol reduced antimicrobial lethality by more than 3 orders of magnitude. Resveratrol also reduced the increase in reactive oxygen species (ROS) characteristic of treatment with quinolone (oxolinic acid). These data support the general idea that the lethal activity of some antimicrobials involves ROS. Surprisingly, subinhibitory concentrations of resveratrol promoted (2- to 6-fold) the recovery of rifampicin-resistant mutants arising from the action of ciprofloxacin, kanamycin, or daptomycin. This result is consistent with resveratrol reducing ROS to sublethal levels that are still mutagenic, while the absence of resveratrol allows ROS levels to high enough to kill mutagenized cells. Suppression of antimicrobial lethality and promotion of mutant recovery by resveratrol suggests that the antioxidant may contribute to the emergence of resistance to several antimicrobials, especially if new derivatives and/or formulations of resveratrol markedly increase bioavailability. PMID:27045517

Heterocycle Thiazole Compounds Exhibit Antifungal Activity through Increase in the Production of Reactive Oxygen Species in the Cryptococcus neoformans-Cryptococcus gattii Species Complex.

PubMed

Sá, Nívea Pereira de; Lima, Caroline Miranda de; Lino, Cleudiomar Inácio; Barbeira, Paulo Jorge Sanches; Baltazar, Ludmila de Matos; Santos, Daniel Assis; Oliveira, Renata Barbosa de; Mylonakis, Eleftherios; Fuchs, Beth Burgwyn; Johann, Susana

2017-08-01

Human cryptococcosis can occur as a primary or opportunistic infection and develops as an acute, subacute, or chronic systemic infection involving different organs of the host. Given the limited therapeutic options and the occasional resistance to fluconazole, there is a need to develop novel drugs for the treatment of cryptococcosis. In this report, we describe promising thiazole compounds 1, 2, 3, and 4 and explore their possible modes of action against Cryptococcus To this end, we show evidence of interference in the Cryptococcus antioxidant system. The tested compounds exhibited MICs ranging from 0.25 to 2 μg/ml against Cryptococcus neoformans strains H99 and KN99α. Interestingly, the knockout strains for Cu oxidase and sarcosine oxidase were resistant to thiazoles. MIC values of thiazole compounds 1, 2, and 4 against these mutants were higher than for the parental strain. After the treatment of C. neoformans ATCC 24067 (or C. deneoformans ) and C. gattii strain L27/01 (or C. deuterogattii ) with thiazoles, we verified an increase in intracellular reactive oxygen species (ROS). Also, we verified the synergistic interactions among thiazoles and menadione, which generates superoxides, with fractional inhibitory concentrations (FICs) equal to 0.1874, 0.3024, 0.25, and 0.25 for the thiazole compounds 1, 2, 3, and 4, respectively. In addition, thiazoles exhibited antagonistic interactions with parasulphonatephenyl porphyrinato ferrate III (FeTPPS). Thus, in this work, we showed that the action of these thiazoles is related to an interference with the antioxidant system. These findings suggest that oxidative stress may be primarily related to the accumulation of superoxide radicals. Copyright © 2017 American Society for Microbiology.

Metabolomics reveals mycoplasma contamination interferes with the metabolism of PANC-1 cells.

PubMed

Yu, Tao; Wang, Yongtao; Zhang, Huizhen; Johnson, Caroline H; Jiang, Yiming; Li, Xiangjun; Wu, Zeming; Liu, Tian; Krausz, Kristopher W; Yu, Aiming; Gonzalez, Frank J; Huang, Min; Bi, Huichang

2016-06-01

Mycoplasma contamination is a common problem in cell culture and can alter cellular functions. Since cell metabolism is either directly or indirectly involved in every aspect of cell function, it is important to detect changes to the cellular metabolome after mycoplasma infection. In this study, liquid chromatography mass spectrometry (LC/MS)-based metabolomics was used to investigate the effect of mycoplasma contamination on the cellular metabolism of human pancreatic carcinoma cells (PANC-1). Multivariate analysis demonstrated that mycoplasma contamination induced significant metabolic changes in PANC-1 cells. Twenty-three metabolites were identified and found to be involved in arginine and purine metabolism and energy supply. This study demonstrates that mycoplasma contamination significantly alters cellular metabolite levels, confirming the compelling need for routine checking of cell cultures for mycoplasma contamination, particularly when used for metabolomics studies. Graphical abstract Metabolomics reveals mycoplasma contamination changes the metabolome of PANC-1 cells.

Concerns about usage of smartphones in operating room and critical care scenario

PubMed Central

Attri, JP; Khetarpal, R; Chatrath, V; Kaur, J

2016-01-01

Smartphones and tablets have taken a central place in the lives of health care professionals. Their use has dramatically improved the communication and has become an important learning tool as the medical information can be assessed online at anytime. In critical care settings, use of smartphone facilitates quick passage of information through E-mail messaging and getting feedback from the concerned physician quickly, thereby reducing medical errors. However, in addition to the benefits offered, these devices have become a significant source of nosocomial infections, distraction for medical professionals and interfere with medical equipments. They may also put privacy and security of patients at stake. The benefits could be severely undermined if abuse and over use are not kept in check. This review article focuses on various applications of smartphones in healthcare practices, drawback of the use of these devices and the recommendations regarding the safe use of these devices. PMID:26952181

Concerns about usage of smartphones in operating room and critical care scenario.

PubMed

Attri, J P; Khetarpal, R; Chatrath, V; Kaur, J

2016-01-01

Smartphones and tablets have taken a central place in the lives of health care professionals. Their use has dramatically improved the communication and has become an important learning tool as the medical information can be assessed online at anytime. In critical care settings, use of smartphone facilitates quick passage of information through E-mail messaging and getting feedback from the concerned physician quickly, thereby reducing medical errors. However, in addition to the benefits offered, these devices have become a significant source of nosocomial infections, distraction for medical professionals and interfere with medical equipments. They may also put privacy and security of patients at stake. The benefits could be severely undermined if abuse and over use are not kept in check. This review article focuses on various applications of smartphones in healthcare practices, drawback of the use of these devices and the recommendations regarding the safe use of these devices.

Visualization of Heart Rate Variability of Long-Term Heart Transplant Patient by Transition Networks: A Case Report.

PubMed

Wdowczyk, Joanna; Makowiec, Danuta; Dorniak, Karolina; Gruchała, Marcin

2016-01-01

We present a heart transplant patient at his 17th year of uncomplicated follow-up. Within a frame of routine check out several tests were performed. With such a long and uneventful follow-up some degree of graft reinnervation could be anticipated. However, the patient's electrocardiogram and exercise parameters seemed largely inconclusive in this regard. The exercise heart rate dynamics were suggestive of only mild, if any parasympathetic reinnervation of the graft with persisting sympathetic activation. On the other hand, traditional heart rate variability (HRV) indices were inadequately high, due to erratic rhythm resulting from interference of the persisting recipient sinus node or non-conducted atrial parasystole. New tools, originated from network representation of time series, by visualization short-term dynamical patterns, provided a method to discern HRV increase due to reinnervation from other reasons.

An Analysis of Measured Pressure Signatures From Two Theory-Validation Low-Boom Models

NASA Technical Reports Server (NTRS)

Mack, Robert J.

2003-01-01

Two wing/fuselage/nacelle/fin concepts were designed to check the validity and the applicability of sonic-boom minimization theory, sonic-boom analysis methods, and low-boom design methodology in use at the end of the 1980is. Models of these concepts were built, and the pressure signatures they generated were measured in the wind-tunnel. The results of these measurements lead to three conclusions: (1) the existing methods could adequately predict sonic-boom characteristics of wing/fuselage/fin(s) configurations if the equivalent area distributions of each component were smooth and continuous; (2) these methods needed revision so the engine-nacelle volume and the nacelle-wing interference lift disturbances could be accurately predicted; and (3) current nacelle-configuration integration methods had to be updated. With these changes in place, the existing sonic-boom analysis and minimization methods could be effectively applied to supersonic-cruise concepts for acceptable/tolerable sonic-boom overpressures during cruise.

"Proceedings of the 22nd Aschauer Soiree on Growth and Health Screening", held at Altenhof, Germany, November 15th, 2014.

PubMed

Hermanussen, Michael; Anisimova, Anna; Abmann, Christian; Van Buuren, Stef; Camara, Antonio D; Elhusseini, Mona Abbas; Hassan, Mortada; El-Shabrawi, Mortada Hassan; Godina, Elena Zinovyevna; Gomula, Aleksandra; Groth, Detlef; Koziel, Slawomir; Lieberman, Leslie Sue; Meigen, Christof; Mumm, Rebekka; Nariyama, Koichi; Nowak-Szczepanska, Natalia; Novokmet, Natalija; Satake, Takashi; Scheffler, Christiane; Soderhall, Jani; Suchomlinov, Andrej; Tutkuviene, Janina; Wit, Jan M; Witwer-Backofen, Ursula; Yestrebsky, Cherie Lynn

2015-03-01

Twenty-five scientists met at Aschauhof, Altenhof, Germany, to discuss various aspects of the complex network of modern health screening, focusing on current scientific topics including medical sciences, human biology, and mathematics; on problems in implementing these results at the practical level of physicians, nurses, technicians, and engineers; and the level of administrative and political decisions. Whereas major scientific advancements have been published in the understanding and the bio-statistical evaluation of anthropometric screening parameters such as serial measurements of height and weight for preventive medical check-ups, BMI screening and surveillance in schools, etc., the implementation of these advancements into current health screening concepts, strategies and decision-making is poor. Fear of discrimination, misperception of body image, behavioural responses and political concerns, meanwhile dominate and negatively interfere with the implementation of recent scientific results into public health screening concepts and practices.

Dual Colorimetric and Fluorescent Authentication Based on Semiconducting Polymer Dots for Anticounterfeiting Applications.

PubMed

Tsai, Wei-Kai; Lai, Yung-Sheng; Tseng, Po-Jung; Liao, Chia-Hsien; Chan, Yang-Hsiang

2017-09-13

Semiconducting polymer dots (Pdots) have recently emerged as a novel type of ultrabright fluorescent probes that can be widely used in analytical sensing and material science. Here, we developed a dual visual reagent based on Pdots for anticounterfeiting applications. We first designed and synthesized two types of photoswitchable Pdots by incorporating photochromic dyes with multicolor semiconducting polymers to modulate their emission intensities and wavelengths. The resulting full-color Pdot assays showed that the colorimetric and fluorescent dual-readout abilities enabled the Pdots to serve as an anticounterfeiting reagent with low background interference. We also doped these Pdots into flexible substrates and prepared these Pdots as inks for pen handwriting as well as inkjet printing. We further applied this reagent in printing paper and checks for high-security anticounterfeiting purposes. We believe that this dual-readout method based on Pdots will create a new avenue for developing new generations of anticounterfeiting technologies.

On vertical seismic profile processing

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

Tariel, P.; Michon, D.

1984-10-01

From the wealth of information which can be deduced from VSP, the information most directly comparable to well logs is considered: P-wave and S-wave interval velocity, acoustic impedance, and the velocity ratio ..gamma.. = V /SUB s/ /V /SUB p/ . This information not only allows better interpretation of surface seismic sections but also improves processing. For these results to be usable a number of precautions must be taken during acquisition and processing; the sampling in depth should be chosen in such a way that aliasing phenomena do not unnecessarily limit the spectra during the separation of upwards and downwardsmore » travelling waves. True amplitudes should be respected and checked by recording of signatures, and the interference of upwards and downwards travelling waves should be taken into account for the picking of first arrivals. The different steps in processing and the combination of results in the interpretation of surface seismic results are described with actual records.« less

Progress and recent developments in the GAINS program

NASA Astrophysics Data System (ADS)

Girz, C. M. I. R.:; MacDonald, A. E.; Caracena, F.; Collander, R. S.; Jamison, B. D.; Anderson, R. L.; Latsch, D.; Lachenmeier, T.; Moody, R. A.; Mares, S.; Cooper, J.; Ganoe, G.; Katzberg, S.; Johnson, T.; Russ, B.

2001-08-01

The GAINS (Global Air-ocean IN-situ System) network of long-duration, high-altitude vehicles is proposed as a means to provide critically needed in-situ observations worldwide. This need is increasingly apparent, for example, in the Arctic where there is growing concern around the shrinking of the ice cap and sea ice extent with concomitant decreases in habitat for animal and plant species. In the mid-latitudes, the sustainability of sufficient soil moisture in grain producing regions is questionable under several climate change scenarios. Preparatory steps using smaller balloons and prototype payloads have been taken toward demonstrating the GAINS balloon concept. The balloon envelope recovery system (BERS) has been tested and radio frequency interference, compatibility and distance checks of the prototype command and communication systems were performed. Electronic and mechanical systems have been integrated in preparation for a 48-h flight of an 18-m diameter prototype.

An overview of protective strategies against ischemia/reperfusion injury: The role of hyperbaric oxygen preconditioning.

PubMed

Hentia, Ciprian; Rizzato, Alex; Camporesi, Enrico; Yang, Zhongjin; Muntean, Danina M; Săndesc, Dorel; Bosco, Gerardo

2018-05-01

Ischemia/reperfusion (I/R) injury, such as myocardial infarction, stroke, and peripheral vascular disease, has been recognized as the most frequent causes of devastating disorders and death currently. Protective effect of various preconditioning stimuli, including hyperbaric oxygen (HBO), has been proposed in the management of I/R. In this study, we searched and reviewed up-to-date published papers to explore the pathophysiology of I/R injury and to understand the mechanisms underlying the protective effect of HBO as conditioning strategy. Animal study and clinic observation support the notion that HBO therapy and conditioning provide beneficial effect against the deleterious effects of postischemic reperfusion. Several explanations have been proposed. The first likely mechanism may be that HBO counteracts hypoxia and reduces I/R injury by improving oxygen delivery to an area with diminished blood flow. Secondly, by reducing hypoxia-ischemia, HBO reduces all the pathological events as a consequence of hypoxia, including tissue edema, increased affective area permeability, postischemia derangement of tissue metabolism, and inflammation. Thirdly, HBO may directly affect cell apoptosis, signal transduction, and gene expression in those that are sensitive to oxygen or hypoxia. HBO provides a reservoir of oxygen at cellular level not only carried by blood, but also by diffusion from the interstitial tissue where it reaches high concentration that may last for several hours, improves endothelial function and rheology, and decreases local inflammation and edema. Evidence suggests the benefits of HBO when used as a preconditioning stimulus in the setting of I/R injury. Translating the beneficial effects of HBO into current practice requires, as for the "conditioning strategies", a thorough consideration of risk factors, comorbidities, and comedications that could interfere with HBO-related protection.

Reactive Oxygen Species Inactivation of Surfactant Involves Structural and Functional Alterations to Surfactant Proteins SP-B and SP-C

PubMed Central

Rodríguez-Capote, Karina; Manzanares, Dahis; Haines, Thomas; Possmayer, Fred

2006-01-01

Exposing bovine lipid extract surfactant (BLES), a clinical surfactant, to reactive oxygen species arising from hypochlorous acid or the Fenton reaction resulted in an increase in lipid (conjugated dienes, lipid aldehydes) and protein (carbonyls) oxidation products and a reduction in surface activity. Experiments where oxidized phospholipids (PL) were mixed with BLES demonstrated that this addition hampered BLES biophysical activity. However the effects were only moderately greater than with control PL. These results imply a critical role for protein oxidation. BLES oxidation by either method resulted in alterations in surfactant proteins SP-B and SP-C, as evidenced by altered Coomassie blue and silver staining. Western blot analyses showed depressed reactivity with specific antibodies. Oxidized SP-C showed decreased palmitoylation. Reconstitution experiments employing PL, SP-B, and SP-C isolated from control or oxidized BLES demonstrated that protein oxidation was more deleterious than lipid oxidation. Furthermore, addition of control SP-B can improve samples containing oxidized SP-C, but not vice versa. We conclude that surfactant oxidation arising from reactive oxygen species generated by air pollution or leukocytes interferes with surfactant function through oxidation of surfactant PL and proteins, but that protein oxidation, in particular SP-B modification, produces the major deleterious effects. PMID:16443649

Arterial input function of an optical tracer for dynamic contrast enhanced imaging can be determined from pulse oximetry oxygen saturation measurements

NASA Astrophysics Data System (ADS)

Elliott, Jonathan T.; Wright, Eric A.; Tichauer, Kenneth M.; Diop, Mamadou; Morrison, Laura B.; Pogue, Brian W.; Lee, Ting-Yim; St. Lawrence, Keith

2012-12-01

In many cases, kinetic modeling requires that the arterial input function (AIF)—the time-dependent arterial concentration of a tracer—be characterized. A straightforward method to measure the AIF of red and near-infrared optical dyes (e.g., indocyanine green) using a pulse oximeter is presented. The method is motivated by the ubiquity of pulse oximeters used in both preclinical and clinical applications, as well as the gap in currently available technologies to measure AIFs in small animals. The method is based on quantifying the interference that is observed in the derived arterial oxygen saturation (SaO2) following a bolus injection of a light-absorbing dye. In other words, the change in SaO2 can be converted into dye concentration knowing the chromophore-specific extinction coefficients, the true arterial oxygen saturation, and total hemoglobin concentration. A simple error analysis was performed to highlight potential limitations of the approach, and a validation of the method was conducted in rabbits by comparing the pulse oximetry method with the AIF acquired using a pulse dye densitometer. Considering that determining the AIF is required for performing quantitative tracer kinetics, this method provides a flexible tool for measuring the arterial dye concentration that could be used in a variety of applications.

Arterial input function of an optical tracer for dynamic contrast enhanced imaging can be determined from pulse oximetry oxygen saturation measurements.

PubMed

Elliott, Jonathan T; Wright, Eric A; Tichauer, Kenneth M; Diop, Mamadou; Morrison, Laura B; Pogue, Brian W; Lee, Ting-Yim; St Lawrence, Keith

2012-12-21

In many cases, kinetic modeling requires that the arterial input function (AIF)--the time-dependent arterial concentration of a tracer--be characterized. A straightforward method to measure the AIF of red and near-infrared optical dyes (e.g., indocyanine green) using a pulse oximeter is presented. The method is motivated by the ubiquity of pulse oximeters used in both preclinical and clinical applications, as well as the gap in currently available technologies to measure AIFs in small animals. The method is based on quantifying the interference that is observed in the derived arterial oxygen saturation (SaO₂) following a bolus injection of a light-absorbing dye. In other words, the change in SaO₂ can be converted into dye concentration knowing the chromophore-specific extinction coefficients, the true arterial oxygen saturation, and total hemoglobin concentration. A simple error analysis was performed to highlight potential limitations of the approach, and a validation of the method was conducted in rabbits by comparing the pulse oximetry method with the AIF acquired using a pulse dye densitometer. Considering that determining the AIF is required for performing quantitative tracer kinetics, this method provides a flexible tool for measuring the arterial dye concentration that could be used in a variety of applications.

Electron paramagnetic resonance oximetry as a quantitative method to measure cellular respiration: a consideration of oxygen diffusion interference.

PubMed

Presley, Tennille; Kuppusamy, Periannan; Zweier, Jay L; Ilangovan, Govindasamy

2006-12-15

Electron paramagnetic resonance (EPR) oximetry is being widely used to measure the oxygen consumption of cells, mitochondria, and submitochondrial particles. However, further improvement of this technique, in terms of data analysis, is required to use it as a quantitative tool. Here, we present a new approach for quantitative analysis of cellular respiration using EPR oximetry. The course of oxygen consumption by cells in suspension has been observed to have three distinct zones: pO(2)-independent respiration at higher pO(2) ranges, pO(2)-dependent respiration at low pO(2) ranges, and a static equilibrium with no change in pO(2) at very low pO(2) values. The approach here enables one to comprehensively analyze all of the three zones together-where the progression of O(2) diffusion zones around each cell, their overlap within time, and their potential impact on the measured pO(2) data are considered. The obtained results agree with previously established methods such as high-resolution respirometry measurements. Additionally, it is also demonstrated how the diffusion limitations can depend on cell density and consumption rate. In conclusion, the new approach establishes a more accurate and meaningful model to evaluate the EPR oximetry data on cellular respiration to quantify related parameters using EPR oximetry.

SSV Launch Monitoring Strategies: HGDS Design Implementation Through System Maturity

NASA Technical Reports Server (NTRS)

Shoemaker, Marc D.; Crimi, Thomas

2010-01-01

With over 500,000 gallons of liquid hydrogen and liquid oxygen, it is of vital importance to monitor the space shuttle vehicle (SSV) from external tank (ET) load through launch. The Hazardous Gas Detection System (HGDS) was installed as the primary system responsible for monitoring fuel leaks within the orbiter and ET. The HGDS was designed to obtain the lowest possible detection limits with the best resolution while monitoring the SSV for any hydrogen, helium, oxygen, or argon as the main requirement. The HGDS is a redundant mass spectrometer used for real-time monitoring during Power Reactant Storage and Distribution (PRSD) load and ET load through launch or scrub. This system also performs SSV processing leak checks of the Tail Service Mast (TSM) umbilical quick disconnects (QD's), Ground Umbilical Carrier Plate (GUCP) QD's and supports auxiliary power unit (APU) system tests. From design to initial implementation and operations, the HGDS has evolved into a mature and reliable launch support system. This paper will discuss the operational challenges and lessons learned from facing design deficiencies, validation and maintenance efforts, life cycle issues, and evolving requirements

The effects of resistance training on metabolic health with weight regain.

PubMed

Warner, Shana O; Linden, Melissa A; Liu, Ying; Harvey, Benjamin R; Thyfault, John P; Whaley-Connell, Adam T; Chockalingam, Anand; Hinton, Pamela S; Dellsperger, Kevin C; Thomas, Tom R

2010-01-01

To determine whether resistance training effectively maintains improvements in cardiometabolic syndrome risk factors during weight regain, 9 individuals lost 4% to 6% of their body weight during an 8- to 12-week diet- and aerobic exercise-induced weight loss phase followed by a controlled weight regain phase (8-12 weeks), during which they regained approximately 50% of the lost weight while participating in a supervised resistance training program. Following weight loss (6.0%+/-0.3%), body mass index, body fat percentage, waist circumference, all abdominal adipose tissue depots, total cholesterol, low-density lipoprotein cholesterol, insulin, and homeostasis model assessment (HOMA) were significantly reduced, while quantitative insulin-sensitivity check index (QUICKI) and cardiorespiratory fitness (maximal oxygen consumption) significantly increased. During weight regain (48.3%+/-3.3% of lost weight), body fat percentage, waist circumference, and maximal oxygen consumption were maintained and muscular strength and lean body mass significantly increased. Abdominal adipose tissue depots, insulin, HOMA, and QUICKI did not significantly change after weight regain. Resistance training was effective in maintaining improvements in metabolic health during weight regain.

A hybrid computer program for rapidly solving flowing or static chemical kinetic problems involving many chemical species

NASA Technical Reports Server (NTRS)

Mclain, A. G.; Rao, C. S. R.

1976-01-01

A hybrid chemical kinetic computer program was assembled which provides a rapid solution to problems involving flowing or static, chemically reacting, gas mixtures. The computer program uses existing subroutines for problem setup, initialization, and preliminary calculations and incorporates a stiff ordinary differential equation solution technique. A number of check cases were recomputed with the hybrid program and the results were almost identical to those previously obtained. The computational time saving was demonstrated with a propane-oxygen-argon shock tube combustion problem involving 31 chemical species and 64 reactions. Information is presented to enable potential users to prepare an input data deck for the calculation of a problem.

Water quality in the tropical Andes hotspot: The Yacuambi river (southeastern Ecuador).

PubMed

Villa-Achupallas, Mercedes; Rosado, Daniel; Aguilar, Silvio; Galindo-Riaño, María Dolores

2018-08-15

Yacuambi river waters (southeast Ecuador, Amazonian region) were assessed to evaluate the potential risk to populations, who use it for drinking and irrigation, and ecosystems, which are part of Tropical Andes hotspot and considered some of the most biodiverse in the world. The water quality index was calculated and some quality parameters were checked to comply with Ecuadorian and North American standards for human consumption, preservation of aquatic life and irrigation. Four samplings were carried out in six stations covering the entire length of the Yacuambi river. Several parameters were analyzed: pH, conductivity, dissolved oxygen, temperature, color, phosphates, nitrite, nitrate, biochemical oxygen demand, chemical oxygen demand, total solids, turbidity, metals (Ba, Cd, Cr, Pb, As and Hg), pesticides and fecal coliforms. The water quality in the Yacuambi river was good and medium according to the classification of the Water Quality Index. However, it was unsuitable for human consumption, preservation of aquatic life and irrigation according to Ecuadorian and North American standards. Arsenic, color and fecal coliforms exceeded the limits for human consumption in all samples tested. Thresholds of preservation of aquatic life were exceeded in all samples in the case of Pb and in some samples for As, pH, nitrite and nitrate. Arsenic and fecal coliforms made Yacuambi river waters unsuitable for irrigation. Copyright © 2018 Elsevier B.V. All rights reserved.

Interference of Detection Rate of Lumbar Disc Herniation by Socioeconomic Status

PubMed Central

Ji, Gyu Yeul; Jung, Nak-Yong; An, Seong Dae; Choi, Won-Seok; Kim, Jung Hoon

2013-01-01

Study Design Retrospective study. Purpose The objective of the study is to evaluate the relationship between the detection rate of lumbar disc herniation and socioeconomic status. Overview of Literature Income is one important determinant of public health. Yet, there are no reports about the relationship between socioeconomic status and the detective rate of disc herniation. Methods In this study, 443 cases were checked for lumbar computed tomography for lumbar disc herniation, and they reviewed questionnaires about their socioeconomic status, the presence of back pain or radiating pain and the presence of a medical certificate (to check the medical or surgical treatment for the pain) during the Korean conscription. Results Without the consideration for the presence of a medical certificate, there was no difference in spinal physical grade according to socioeconomic status (p=0.290). But, with the consideration of the presence of a medical certificate, the significant statistical differences were observed according to socioeconomic status in 249 cases in the presence of a medical certificate (p=0.028). There was a lower detection rate in low economic status individuals than those in the high economic class. The common reason for not submitting a medical certificate is that it is neither necessary for the people of lower socioeconomic status nor is it financially affordable. Conclusions The prevalence of lumbar disc herniation is not different according to socioeconomic status, but the detective rate was affected by socioeconomic status. Socioeconomic status is an important factor for detecting lumbar disc herniation. PMID:23508288

Adolescent self-harm and risk factors.

PubMed

Zhang, Jixiang; Song, Jianwei; Wang, Jing

2016-12-01

This study aims to define the characteristics of adolescents who have engaged in self-harm behavior and ascertain the risk factors. From January 2013 to January 2014, 4,176 adolescents from senior middle schools in Linyi, China, were administered four questionnaire surveys to ascertain the following: incidence of self-harm behavior regarding the frequency of different self-harm behaviors by group (never/one to five times/greater than five times in the last 6 months) and then comparing the self-harm behavior of the different subgroups; symptom self-check, comparing the differences between the adolescents with self-harm behavior and without in nine subscales (somatization, obsessive-compulsive symptoms, interpersonal sensitivity, depression, anxiety, hostility, fear, paranoid, and psychosis); Adolescent Self-Rating Life Events Check List scores; and Egna Minnenav Barndoms Uppfostran (EMBU) scores. Multivariate logistic regression analysis was used to determine the risk factors of self-harm in adolescents. The incidence of adolescent self-harm was 27.60%; the occurrence of adolescent self-harm was closely related to their mental health status, stressful life events, and EMBU. Being female, an urban student, or an only child; having poor school performance or experiences of stressful life events, harsh parenting styles, or excessive interference; and poor mental health were the risk factors for adolescent self-harm. The incidence of adolescent self-harm was high, and their mental health status, stressful life events, and EMBU affected the occurrence of adolescent self-harm, which is an issue that needs greater attention. © 2016 John Wiley & Sons Australia, Ltd.

Interference of detection rate of lumbar disc herniation by socioeconomic status.

PubMed

Ji, Gyu Yeul; Oh, Chang Hyun; Jung, Nak-Yong; An, Seong Dae; Choi, Won-Seok; Kim, Jung Hoon

2013-03-01

Retrospective study. The objective of the study is to evaluate the relationship between the detection rate of lumbar disc herniation and socioeconomic status. Income is one important determinant of public health. Yet, there are no reports about the relationship between socioeconomic status and the detective rate of disc herniation. In this study, 443 cases were checked for lumbar computed tomography for lumbar disc herniation, and they reviewed questionnaires about their socioeconomic status, the presence of back pain or radiating pain and the presence of a medical certificate (to check the medical or surgical treatment for the pain) during the Korean conscription. Without the consideration for the presence of a medical certificate, there was no difference in spinal physical grade according to socioeconomic status (p=0.290). But, with the consideration of the presence of a medical certificate, the significant statistical differences were observed according to socioeconomic status in 249 cases in the presence of a medical certificate (p=0.028). There was a lower detection rate in low economic status individuals than those in the high economic class. The common reason for not submitting a medical certificate is that it is neither necessary for the people of lower socioeconomic status nor is it financially affordable. The prevalence of lumbar disc herniation is not different according to socioeconomic status, but the detective rate was affected by socioeconomic status. Socioeconomic status is an important factor for detecting lumbar disc herniation.

Assessment of environmental effects on Space Station Freedom Electrical Power System

NASA Technical Reports Server (NTRS)

Lu, Cheng-Yi; Nahra, Henry K.

1991-01-01

Analyses of EPS (electrical power system) interactions with the LEO (low earth orbit) environment are described. The results of these analyses will support EPS design so as to be compatible with the natural and induced environments and to meet power, lifetime, and performance requirements. The environmental impacts to the Space Station Freedom EPS include aerodynamic drag, atomic oxygen erosion, ultraviolet degradation, VXB effect, ionizing radiation dose and single event effects, electromagnetic interference, electrostatic discharge, plasma interactions (ion sputtering, arcing, and leakage current), meteoroid and orbital debris threats, thermal cycling effects, induced current and voltage potential differences in the SSF due to induced electric field, and contamination degradation.

Hebb, pandemonium and catastrophic hypermnesia: the hippocampus as a suppressor of inappropriate associations.

PubMed

McNaughton, Neil; Wickens, Jeff

2003-01-01

The hippocampus has been proposed as a key component of a "behavioural inhibition system". We explore the implications of this idea for the nature of associative memory--i.e. learning that is distinct from the moulding of response sequences by error correction and reinforcement. It leads to the view that all associative memory depends on purely Hebbian mechanisms. Memories involve acquisition of new goals not the strengthening of new stimulus-response links. Critically, memories will consist of affectively positive and affectively negative associations as well "purely cognitive" information. The hippocampus is seen as a supervisor that is normally "just checking" information about current available goals. When one available goal is pre-eminent there is no hippocampal output and the goal controls the response system. When two or more goals are similarly and highly primed there is conflict. This is detected by the hippocampus which sends output that increases the valence of affectively negative perceptions and so resolves the conflict by suppressing more aversive goals. Such conflict resolution occurs with innate as well as acquired goals and is fundamentally non-memorial. But, in memory paradigms, it can often act to suppress interference on the current trial and, through Hebbian association of the increase in negative affect, decrease the probability of interference on later trials and during consolidation. Both memory-driven and innate behaviour is made hippocampal-dependent by innate and acquired conflicting tendencies and not the class of stimulus presented.

Inter-track interference mitigation with two-dimensional variable equalizer for bit patterned media recording

NASA Astrophysics Data System (ADS)

Wang, Yao; Vijaya Kumar, B. V. K.

2017-05-01

The increased track density in bit patterned media recording (BPMR) causes increased inter-track interference (ITI), which degrades the bit error rate (BER) performance. In order to mitigate the effect of the ITI, signals from multiple tracks can be equalized by a 2D equalizer with 1D target. Usually, the 2D fixed equalizer coefficients are obtained by using a pseudo-random bit sequence (PRBS) for training. In this study, a 2D variable equalizer is proposed, where various sets of 2D equalizer coefficients are predetermined and stored for different ITI patterns besides the usual PRBS training. For data detection, as the ITI patterns are unknown in the first global iteration, the main and adjacent tracks are equalized with the conventional 2D fixed equalizer, detected with Bahl-Cocke-Jelinek-Raviv (BCJR) detector and decoded with low-density parity-check (LDPC) decoder. Then using the estimated bit information from main and adjacent tracks, the ITI pattern for each island of the main track can be estimated and the corresponding 2D variable equalizers are used to better equalize the bits on the main track. This process is executed iteratively by feeding back the main track information. Simulation results indicate that for both single-track and two-track detection, the proposed 2D variable equalizer can achieve better BER and frame error rate (FER) compared to that with the 2D fixed equalizer.

Probing CP violation in e + e − production of the Higgs boson and toponia

DOE PAGES

Hagiwara, Kaoru; Ma, Kai; Yokoya, Hiroshi

2016-06-01

We study the CP violation in the Higgs boson and toponia production process at the ILC where the toponia are produced near the threshold. With the approximation that the production vertex of the Higgs boson and toponia is contact, and neglecting the P-wave toponia, we analytically calculated the density matrix for the production and decay of the toponia. Under these assumptions, the production spectrum of the toponia is solely determined by the spin quantum number, therefore the toponia can be either singlet or triplet. We find that the production rate of the singlet toponium is highly suppressed, and behaves justmore » like the production of a P-wave toponia. In the case of the triplet toponium, three completely independent CP observables, namely azimuthal angles of lepton and antilepton in the toponium rest-frame as well as their sum, are predicted based on our analytical results, and checked by using the tree-level event generator. The non-trivial correlations come from the longitudinal-transverse interferences for the azimuthal angles of leptons, and the transverse-transverse interference for their sum. These three observables are well defined at the ILC, where the rest frame of the toponium can be reconstructed directly. Furthermore, the QCD-strong corrections, which are important near the threshold region, are also studied with the approximation of spin-independent QCD-Coulomb potential. While the total cross section is enhanced, the spin correlations predicted in this paper are not affected.« less

LoRa Scalability: A Simulation Model Based on Interference Measurements

PubMed Central

Haxhibeqiri, Jetmir; Van den Abeele, Floris; Moerman, Ingrid; Hoebeke, Jeroen

2017-01-01

LoRa is a long-range, low power, low bit rate and single-hop wireless communication technology. It is intended to be used in Internet of Things (IoT) applications involving battery-powered devices with low throughput requirements. A LoRaWAN network consists of multiple end nodes that communicate with one or more gateways. These gateways act like a transparent bridge towards a common network server. The amount of end devices and their throughput requirements will have an impact on the performance of the LoRaWAN network. This study investigates the scalability in terms of the number of end devices per gateway of single-gateway LoRaWAN deployments. First, we determine the intra-technology interference behavior with two physical end nodes, by checking the impact of an interfering node on a transmitting node. Measurements show that even under concurrent transmission, one of the packets can be received under certain conditions. Based on these measurements, we create a simulation model for assessing the scalability of a single gateway LoRaWAN network. We show that when the number of nodes increases up to 1000 per gateway, the losses will be up to 32%. In such a case, pure Aloha will have around 90% losses. However, when the duty cycle of the application layer becomes lower than the allowed radio duty cycle of 1%, losses will be even lower. We also show network scalability simulation results for some IoT use cases based on real data. PMID:28545239

LoRa Scalability: A Simulation Model Based on Interference Measurements.

PubMed

Haxhibeqiri, Jetmir; Van den Abeele, Floris; Moerman, Ingrid; Hoebeke, Jeroen

2017-05-23

LoRa is a long-range, low power, low bit rate and single-hop wireless communication technology. It is intended to be used in Internet of Things (IoT) applications involving battery-powered devices with low throughput requirements. A LoRaWAN network consists of multiple end nodes that communicate with one or more gateways. These gateways act like a transparent bridge towards a common network server. The amount of end devices and their throughput requirements will have an impact on the performance of the LoRaWAN network. This study investigates the scalability in terms of the number of end devices per gateway of single-gateway LoRaWAN deployments. First, we determine the intra-technology interference behavior with two physical end nodes, by checking the impact of an interfering node on a transmitting node. Measurements show that even under concurrent transmission, one of the packets can be received under certain conditions. Based on these measurements, we create a simulation model for assessing the scalability of a single gateway LoRaWAN network. We show that when the number of nodes increases up to 1000 per gateway, the losses will be up to 32%. In such a case, pure Aloha will have around 90% losses. However, when the duty cycle of the application layer becomes lower than the allowed radio duty cycle of 1%, losses will be even lower. We also show network scalability simulation results for some IoT use cases based on real data.

Application of radiofrequency energy in surgical and interventional procedures: are there interactions with ICDs?

PubMed

Fiek, Michael; Dorwarth, Uwe; Durchlaub, Ilka; Janko, Sabine; Von Bary, Christian; Steinbeck, Gerhard; Hoffmann, Ellen

2004-03-01

During surgical and interventional procedures, interference may occur between ICDs and electrical cautery or with the application of RF energy. This may lead to the false induction of ICD therapies or could even result in device malfunction, which represents a potential perioperative hazard for the patient. This study analyzed the intraoperative interactions in 45 consecutive ICD patients in reference to different surgical and interventional procedures. A total of 33 surgical operations (general surgery [n = 14], urologic [n = 5], abdominal [n = 10], gynecological [n = 2], thoracic [n = 1], neurosurgical [n = 1]) and 12 interventional therapies (RF catheter ablation [n = 10], endoscopic papillotomy [n = 2]) were performed. The ICD devices were all located in left pectoral position and consisted of 25 single and 20 dual chamber defibrillators. During the procedure, tachyarrhythmia detection (VF 296 +/- 20 ms, VT 376 +/- 49 ms) of the devices was maintained active (monitoring mode), only ICD therapies were inactivated. The indifferent electrode of the electrical cauter/RF generator was placed in standard positions (right/left mid-femoral position [n = 27/8], thoracic spine area [n = 10]). After the procedure, the ICD memory was checked for detections and for changes in the programming. There was no oversensing, reprogramming, or damage of any defibrillator caused by RF energy. Despite the lack of undesired interactions, ICDs should be inactivated preoperatively to assure maximum patient safety. However, should inactivation not be possible, or the achievement uncertain, electromagnetic interference is highly unlikely.

Probing CP violation in e +e - production of the Higgs boson and toponia

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

Hagiwara, Kaoru; Ma, Kai; Yokoya, Hiroshi

We study the CP violation in the Higgs boson and toponia production process at the ILC where the toponia are produced near the threshold. With the approximation that the production vertex of the Higgs boson and toponia is contact, and neglecting the P-wave toponia, we analytically calculated the density matrix for the production and decay of the toponia. Under these assumptions, the production spectrum of the toponia is solely determined by the spin quantum number, therefore the toponia can be either singlet or triplet. We find that the production rate of the singlet toponium is highly suppressed, and behaves justmore » like the production of a P-wave toponia. In the case of the triplet toponium, three completely independent CP observables, namely azimuthal angles of lepton and antilepton in the toponium rest-frame as well as their sum, are predicted based on our analytical results, and checked by using the tree-level event generator. The non-trivial correlations come from the longitudinal-transverse interferences for the azimuthal angles of leptons, and the transverse-transverse interference for their sum. These three observables are well defined at the ILC, where the rest frame of the toponium can be reconstructed directly. Furthermore, the QCD-strong corrections, which are important near the threshold region, are also studied with the approximation of spin-independent QCD-Coulomb potential. While the total cross section is enhanced, the spin correlations predicted in this paper are not affected.« less

Probing CP violation in e +e - production of the Higgs boson and toponia

DOE PAGES

Hagiwara, Kaoru; Ma, Kai; Yokoya, Hiroshi

2016-06-08

We study the CP violation in the Higgs boson and toponia production process at the ILC where the toponia are produced near the threshold. With the approximation that the production vertex of the Higgs boson and toponia is contact, and neglecting the P-wave toponia, we analytically calculated the density matrix for the production and decay of the toponia. Under these assumptions, the production spectrum of the toponia is solely determined by the spin quantum number, therefore the toponia can be either singlet or triplet. We find that the production rate of the singlet toponium is highly suppressed, and behaves justmore » like the production of a P-wave toponia. In the case of the triplet toponium, three completely independent CP observables, namely azimuthal angles of lepton and antilepton in the toponium rest-frame as well as their sum, are predicted based on our analytical results, and checked by using the tree-level event generator. The non-trivial correlations come from the longitudinal-transverse interferences for the azimuthal angles of leptons, and the transverse-transverse interference for their sum. These three observables are well defined at the ILC, where the rest frame of the toponium can be reconstructed directly. Furthermore, the QCD-strong corrections, which are important near the threshold region, are also studied with the approximation of spin-independent QCD-Coulomb potential. While the total cross section is enhanced, the spin correlations predicted in this paper are not affected.« less

Advanced glycation end-products and insulin signaling in granulosa cells

PubMed Central

Chatzigeorgiou, Antonios; Papageorgiou, Efstathia; Koundouras, Dimitrios; Koutsilieris, Michael

2016-01-01

Advanced glycation end-products (AGEs) may interfere with insulin intracellular signaling and glucose transport in human granulosa cells, potentially affecting ovarian function, follicular growth, linked with diminished fertility. The potential interaction of AGEs with insulin signaling pathways and glucose transport was investigated in human granulosa KGN cells. KGN cells were cultured with variable concentrations of human glycated albumin (HGA, 50–200 µg/mL) or insulin (100 ng/mL). Combined treatments of KGN cells with insulin (100 ng/mL) and HGA (200 µg/mL) were also performed. p-AKT levels and glucose transporter type 4 (Glut-4) translocation analysis were performed by Western blot. Phosphatidylinositol-3-kinase (PI3K)-specific signaling was checked by using the PI3K-inhibitor, LY294002. p-AKT levels were significantly increased following insulin treatment compared to basal levels or HGA exposure. This insulin-mediated AKT-phosphorylation was PI3K-specific and it was inhibited after combined treatment of insulin and HGA. Furthermore, Glut-4 translocation from the cytoplasm to the membrane compartments of KGN cells was remarkably reduced after the combined treatment of insulin and HGA. The present findings support that AGEs interfere with insulin signaling in granulosa cells and prevent Glut-4 membrane translocation suggesting that intra ovarian AGEs accumulation, from endogenous or exogenous sources, may contribute to the pathophysiology of states characterized with anovulation and insulin resistance such as polycystic ovary syndrome. PMID:25956684

Increased ventilation by fish leads to a higher risk of parasitism.

PubMed

Mikheev, Victor N; Pasternak, Anna F; Valtonen, E Tellervo; Taskinen, Jouni

2014-06-23

Fish are common intermediate hosts of trematode cercariae and their gills can potentially serve as important sites of penetration by these larval stages. We experimentally tested the hypothesis that volume of ventilation flow across the gills contributes to acquisition of these parasites by fish. We manipulated the intensity of ventilation by using different oxygen concentrations. Juvenile Oncorhynchus mykiss were individually exposed for 10 minutes to a standard dose of Diplostomum pseudospathaceum cercariae at three levels of oxygen concentration, 30, 60 and 90%. Ventilation amplitude (measured as a distance between left and right operculum), operculum beat rate, and the number of cercariae established in the eyes of fish were recorded. Fish reacted to low oxygen concentration with wider expansion of opercula (but not with increasing beat rate), leading to an increase in ventilation volume. As expected, the intensity of infection increased with decreasing oxygen saturation-probably due to a higher exposure to cercariae caused by increased ventilation under low oxygen concentrations. The number of cercariae acquired by an individual fish was positively correlated with ventilation amplitude and with ventilation volume, but not with operculum beat rate. However, even though the infection rate increased under these circumstances, the proportion of larval trematodes successfully establishing in fish eyes decreased with increasing ventilation volume, suggesting that the high flow velocity, although increasing host exposure to cercarial parasites, may interfere with the ability of these parasites to penetrate their hosts. There was no difference in the behaviour of trematode cercariae exposed to low and high oxygen concentrations. A reduction in oxygen saturation resulted in an increase in ventilation volume across the gills and in doing so an increase in the exposure of fish to cercariae. A significant correlation between ventilation volume and parasitism represents the first experimental evidence that this physiological mechanism generates variation in transmission of parasites to fish hosts. Other factors that modify ventilation flow, e.g. physiological or social stressors, are expected to produce similar effects on the transmission success of the parasites penetrating fish hosts using the gills.

Increased ventilation by fish leads to a higher risk of parasitism

PubMed Central

2014-01-01

Background Fish are common intermediate hosts of trematode cercariae and their gills can potentially serve as important sites of penetration by these larval stages. We experimentally tested the hypothesis that volume of ventilation flow across the gills contributes to acquisition of these parasites by fish. We manipulated the intensity of ventilation by using different oxygen concentrations. Methods Juvenile Oncorhynchus mykiss were individually exposed for 10 minutes to a standard dose of Diplostomum pseudospathaceum cercariae at three levels of oxygen concentration, 30, 60 and 90%. Ventilation amplitude (measured as a distance between left and right operculum), operculum beat rate, and the number of cercariae established in the eyes of fish were recorded. Results Fish reacted to low oxygen concentration with wider expansion of opercula (but not with increasing beat rate), leading to an increase in ventilation volume. As expected, the intensity of infection increased with decreasing oxygen saturation—probably due to a higher exposure to cercariae caused by increased ventilation under low oxygen concentrations. The number of cercariae acquired by an individual fish was positively correlated with ventilation amplitude and with ventilation volume, but not with operculum beat rate. However, even though the infection rate increased under these circumstances, the proportion of larval trematodes successfully establishing in fish eyes decreased with increasing ventilation volume, suggesting that the high flow velocity, although increasing host exposure to cercarial parasites, may interfere with the ability of these parasites to penetrate their hosts. There was no difference in the behaviour of trematode cercariae exposed to low and high oxygen concentrations. Conclusion A reduction in oxygen saturation resulted in an increase in ventilation volume across the gills and in doing so an increase in the exposure of fish to cercariae. A significant correlation between ventilation volume and parasitism represents the first experimental evidence that this physiological mechanism generates variation in transmission of parasites to fish hosts. Other factors that modify ventilation flow, e.g. physiological or social stressors, are expected to produce similar effects on the transmission success of the parasites penetrating fish hosts using the gills. PMID:24954703

Performance characteristics of an automated gas chromatograph-ion trap mass spectrometer system used for the 1995 Southern Oxidants Study field investigation in Nashville, Tennessee

NASA Astrophysics Data System (ADS)

Daughtrey, E. Hunter; Adams, Jeffrey R.; Oliver, Karen D.; Kronmiller, Keith G.; McClenny, William A.

1998-09-01

A trailer-deployed automated gas chromatograph-mass spectrometer (autoGC-MS) system capable of making continuous hourly measurements was used to determine volatile organic compounds (VOCs) in ambient air at New Hendersonville, Tennessee, and Research Triangle Park, North Carolina, in 1995. The system configuration, including the autoGC-MS, trailer and transfer line, siting, and sampling plan and schedule, is described. The autoGC-MS system employs a pair of matched sorbent traps to allow simultaneous sampling and desorption. Desorption is followed by Stirling engine cryofocusing and subsequent GC separation and mass spectral identification and quantification. Quality control measurements described include evaluating precision and accuracy of replicate analyses of independently supplied audit and round-robin canisters and determining the completeness of the data sets taken in Tennessee. Data quality objectives for precision (±10%) and accuracy (±20%) of 10- to 20-ppbv audit canisters and a completeness of >75% data capture were met. Quality assurance measures used in reviewing the data set include retention time stability, calibration checks, frequency distribution checks, and checks of the mass spectra. Special procedures and tests were used to minimize sorbent trap artifacts, to verify the quality of a standard prepared in our laboratory, and to prove the integrity of the insulated, heated transfer line. A rigorous determination of total system blank concentration levels using humidified scientific air spiked with ozone allowed estimation of method detection limits, ranging from 0.01 to 1.0 ppb C, for most of the 100 target compounds, which were a composite list of the target compounds for the Photochemical Assessment Monitoring Station network, those for Environmental Protection Agency method TO-14, and selected oxygenated VOCs.

Perinatal asphyxia: CNS development and deficits with delayed onset

PubMed Central

Herrera-Marschitz, Mario; Neira-Pena, Tanya; Rojas-Mancilla, Edgardo; Espina-Marchant, Pablo; Esmar, Daniela; Perez, Ronald; Muñoz, Valentina; Gutierrez-Hernandez, Manuel; Rivera, Benjamin; Simola, Nicola; Bustamante, Diego; Morales, Paola; Gebicke-Haerter, Peter J.

2013-01-01

Perinatal asphyxia constitutes a prototype of obstetric complications occurring when pulmonary oxygenation is delayed or interrupted. The primary insult relates to the duration of the period lacking oxygenation, leading to death if not re-established. Re-oxygenation leads to a secondary insult, related to a cascade of biochemical events required for restoring proper function. Perinatal asphyxia interferes with neonatal development, resulting in long-term deficits associated to mental and neurological diseases with delayed clinical onset, by mechanisms not yet clarified. In the experimental scenario, the effects observed long after perinatal asphyxia have been explained by overexpression of sentinel proteins, such as poly(ADP-ribose) polymerase-1 (PARP-1), competing for NAD+ during re-oxygenation, leading to the idea that sentinel protein inhibition constitutes a suitable therapeutic strategy. Asphyxia induces transcriptional activation of pro-inflammatory factors, in tandem with PARP-1 overactivation, and pharmacologically induced PARP-1 inhibition also down-regulates the expression of proinflammatory cytokines. Nicotinamide has been proposed as a suitable PARP-1 inhibitor. Its effect has been studied in an experimental model of global hypoxia in rats. In that model, the insult is induced by immersing rat fetus into a water bath for various periods of time. Following asphyxia, the pups are delivered, treated, and nursed by surrogate dams, pending further experiments. Nicotinamide rapidly distributes into the brain following systemic administration, reaching steady state concentrations sufficient to inhibit PARP-1 activity for several hours, preventing several of the long-term consequences of perinatal asphyxia, supporting the idea that nicotinamide constitutes a lead for exploring compounds with similar or better pharmacological profiles. PMID:24723845

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

Numakura, H.

The structure and the formation mechanism of oxides during internal oxidation have attracted much attention, and extensive studies have been carried out on this subject. Recently, Jang et al. reported the results of atom-probe microanalysis of oxide particles, or solute-oxygen clusters, in an internally oxidized Cu-0.16 at.% Mg alloy. They found that the composition varies from particle to particle even in the same specimen, and reported that some clusters consist only of magnesium atoms. On the basis of the results, they suggested that the oxidation proceeds in this alloy as follows: (1) the solute atoms form clusters, (2) the clustersmore » absorb oxygen atoms to form both hypo- and hyperstoichiometric oxide particles, (3) the particles grow to form the stoichiometric oxide, MgO. They show the presence of Mg atom clusters with no oxygen association. By assuming that the analyzed area is in the unoxidized region, i.e., ahead of the oxidation front, they interpret this observation as evidence for clustering of the solute atoms prior to oxide formation. However, according to the phase diagram, such clustering is not expected in the absence of oxygen, since the solute concentration, 0.16 at.%, is far below the solubility limit at the oxidation temperature of 900[degree]C, about 3.5 at.%. In atom probe experiments, it sometimes happens that detection efficiencies for different ion species are considerably different because some experimental parameters are not chosen properly. It seems possible that the data resulted from an unusually low detection efficiency for O ions. Since their conclusion raises an important issue on the mechanism of internal oxidation, it is desirable to examine experimental conditions carefully, and to check the reproducibility of data.« less

SU-E-T-326: The Oxygen Saturation (SO2) and Breath-Holding Time Variation Applied Active Breathing Control (ABC)

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

Gong, G; Yin, Y

Purpose: To study the oxygen saturation (SO2) and breath-holding time variation applied active breathing control (ABC) in radiotherapy of tumor. Methods: 24 volunteers were involved in our trials, and they all did breath-holding motion assisted by ELEKTA Active Breathing Coordinator 2.0 for 10 times respectively. And the patient monitor was used to observe the oxygen saturation (SO2) variation. The variation of SO2, and length of breath-holding time and the time for recovering to the initial value of SO2 were recorded and analyzed. Results: (1) The volunteers were divided into two groups according to the SO2 variation in breath-holding: A group,more » 14 cases whose SO2 reduction were more than 2% (initial value was 97% to 99%, while termination value was 91% to 96%); B group, 10 cases were less than 2% in breath-holding without inhaling oxygen. (2) The interfraction breath holding time varied from 8 to 20s for A group compared to the first breath-holding time, and for B group varied from 4 to 14s. (3) The breathing holding time of B group prolonged mean 8s, compared to A group. (4) The time for restoring to the initial value of SO2 was from 10s to 30s. And the breath-holding time shortened obviously for patients whose SO2 did not recover to normal. Conclusion: It is very obvious that the SO2 reduction in breath-holding associated with ABC for partial people. It is necessary to check the SO2 variation in breath training, and enough time should be given to recover SO2.« less

Serum concentrations of the derivatives of reactive oxygen metabolites (d-ROMs) in dogs with leishmaniosis.

PubMed

Paltrinieri, Saverio; Ravicini, Sara; Rossi, Gabriele; Roura, Xavier

2010-12-01

Leishmania infantum interferes with the oxidative metabolism of phagocytes. In order to assess whether derivatives of reactive oxygen metabolites (d-ROMs) decrease due to infection or increase due to inflammation, d-ROMs were measured in serum collected from control dogs (Group 1; n = 12), from dogs seropositive for Leishmania either symptomatic (Group 2; n = 27) or not (Group 3; n = 14), and from dogs with other diseases (Group 4; n = 16). The concentrations of d-ROMs in the four groups, expressed in Carratelli Units (U CARR) were, respectively, 75.4 ± 39.5 (median, 81.6), 108.2 ± 96.3 (73.4), 73.5 ± 62.2 (62.0), 127.7 ± 97.3 (94.3). There were no significant differences between groups, but dogs with values higher than the reference interval were found, mostly in Groups 2 and 4 (which had serum C-reactive protein levels consistent with inflammation), whilst low values were occasionally found in Groups 2 and 3. Inflammation may mask decreases in d-ROMs induced by Leishmania infection. Copyright © 2009 Elsevier Ltd. All rights reserved.

Ethical Issues in the Use of Extracorporeal Membrane Oxygenation in Controlled Donation After Circulatory Determination of Death.

PubMed

Dalle Ave, A L; Shaw, D M; Bernat, J L

2016-08-01

The use of donor extracorporeal membrane oxygenation (ECMO) to improve graft outcomes by some controlled donation after circulatory determination of death (cDCDD) programs raises ethical issues. We reviewed cDCDD protocols using ECMO and the relevant ethics literature to analyze these issues. It is not obvious that ECMO in cDCDD improves graft outcomes. In our opinion, ECMO implemented before death can interfere with end-of-life care and damage bodily integrity. By restoring systemic circulation, ECMO risks invalidating the preceding declaration of death if brain and cardiac perfusion is not adequately excluded because of malfunction or misplacement of the supradiaphragmatic aortic occlusion balloon. The use of ECMO is not compatible with the acronym DCDD because circulation is restored after the determination of death. Because of these deficiencies, we concluded that other techniques are preferable, such as rapid recovery or in situ cold infusion. If ECMO is performed, it requires a specific informed consent and transparency. © Copyright 2016 The American Society of Transplantation and the American Society of Transplant Surgeons.

Mitochondrial electron transport chain identified as a novel molecular target of SPIO nanoparticles mediated cancer-specific cytotoxicity.

PubMed

He, Chengyong; Jiang, Shengwei; Jin, Haijing; Chen, Shuzhen; Lin, Gan; Yao, Huan; Wang, Xiaoyong; Mi, Peng; Ji, Zhiliang; Lin, Yuchun; Lin, Zhongning; Liu, Gang

2016-03-01

Superparamagnetic iron oxide nanoparticles (SPIONs) are highly cytotoxic and target cancer cells with high specificity; however, the mechanism by which SPIONs induce cancer cell-specific cytotoxicity remains unclear. Herein, the molecular mechanism of SPION-induced cancer cell-specific cytotoxicity to cancer cells is clarified through DNA microarray and bioinformatics analyses. SPIONs can interference with the mitochondrial electron transport chain (METC) in cancer cells, which further affects the production of ATP, mitochondrial membrane potential, and microdistribution of calcium, and induces cell apoptosis. Additionally, SPIONs induce the formation of reactive oxygen species in mitochondria; these reactive oxygen species trigger cancer-specific cytotoxicity due to the lower antioxidative capacity of cancer cells. Moreover, the DNA microarray and gene ontology analyses revealed that SPIONs elevate the expression of metallothioneins in both normal and cancer cells but decrease the expression of METC genes in cancer cells. Overall, these results suggest that SPIONs induce cancer cell death by targeting the METC, which is helpful for designing anti-cancer nanotheranostics and evaluating the safety of future nanomedicines. Copyright © 2016 Elsevier Ltd. All rights reserved.

In vitro therapeutic effect of PDT combined with VEGF-A gene therapy

NASA Astrophysics Data System (ADS)

Lecaros, Rumwald Leo G.; Huang, Leaf; Hsu, Yih-Chih

2014-02-01

Vascular endothelial growth factor A (VEGF-A), commonly known as VEGF, is one of the primary factors that affect tumor angiogenesis. It was found to be expressed in cancer cell lines including oral squamous cell carcinoma. Photodynamic therapy (PDT) is a novel therapeutic modality to treat cancer by using a photosensitizer which is activated by a light source to produce reactive oxygen species and mediates oxygen-independent hypoxic conditions to tumor. Another emerging treatment to cure cancer is the use of interference RNA (e.g. siRNA) to silence a specific mRNA sequence. VEGF-A was found to be expressed in oral squamous cell carcinoma and overexpressed after 24 hour post-PDT by Western blot analysis. Cell viability was found to decrease at 25 nM of transfected VEGF-A siRNA. In vitro combined therapy of PDT and VEGF-A siRNA showed better response as compared with PDT and gene therapy alone. The results suggest that PDT combined with targeted gene therapy has a potential mean to achieve better therapeutic outcome.

Analysis of antioxidant activities of common vegetables employing oxygen radical absorbance capacity (ORAC) and ferric reducing antioxidant power (FRAP) assays: a comparative study.

PubMed

Ou, Boxin; Huang, Dejian; Hampsch-Woodill, Maureen; Flanagan, Judith A; Deemer, Elizabeth K

2002-05-22

A total of 927 freeze-dried vegetable samples, including 111 white cabbages, 59 carrots, 51 snap beans, 57 cauliflower, 33 white onions, 48 purple onions, 130 broccoli, 169 tomatoes, 25 beets, 88 peas, 88 spinach, 18 red peppers, and 50 green peppers, were analyzed using the oxygen radical absorption capacity (ORAC) and ferric reducing antioxidant capacity (FRAP) methods. The data show that the ORAC and FRAP values of vegetable are not only dependent on species, but also highly dependent on geographical origin and harvest time. The two antioxidant assay methods, ORAC and FRAP, also give different antioxidant activity trends. The discrepancy is extensively discussed based on the chemistry principles upon which these methods are built, and it is concluded that the ORAC method is chemically more relevant to chain-breaking antioxidants activity, while the FRAP has some drawbacks such as interference, reaction kinetics, and quantitation methods. On the basis of the ORAC results, green pepper, spinach, purple onion, broccoli, beet, and cauliflower are the leading sources of antioxidant activities against the peroxyl radicals.

A bacterial cysteine protease effector protein interferes with photosynthesis to suppress plant innate immune responses.

PubMed

Rodríguez-Herva, José J; González-Melendi, Pablo; Cuartas-Lanza, Raquel; Antúnez-Lamas, María; Río-Alvarez, Isabel; Li, Ziduo; López-Torrejón, Gema; Díaz, Isabel; Del Pozo, Juan C; Chakravarthy, Suma; Collmer, Alan; Rodríguez-Palenzuela, Pablo; López-Solanilla, Emilia

2012-05-01

The bacterial pathogen Pseudomonas syringae pv tomato DC3000 suppresses plant innate immunity with effector proteins injected by a type III secretion system (T3SS). The cysteine protease effector HopN1, which reduces the ability of DC3000 to elicit programmed cell death in non-host tobacco, was found to also suppress the production of defence-associated reactive oxygen species (ROS) and callose when delivered by Pseudomonas fluorescens heterologously expressing a P. syringae T3SS. Purified His(6) -tagged HopN1 was used to identify tomato PsbQ, a member of the oxygen evolving complex of photosystem II (PSII), as an interacting protein. HopN1 localized to chloroplasts and both degraded PsbQ and inhibited PSII activity in chloroplast preparations, whereas a HopN1(D299A) non-catalytic mutant lost these abilities. Gene silencing of NtPsbQ in tobacco compromised ROS production and programmed cell death by DC3000. Our data reveal PsbQ as a contributor to plant immunity responses and a target for pathogen suppression. © 2012 Blackwell Publishing Ltd.

Multi-element analysis of water decoction of medicine food homology plants using inductively coupled plasma-tandem mass spectrometry

NASA Astrophysics Data System (ADS)

Fu, Liang; Shi, Shu-Yun; Chen, Xiao-Qing

2017-07-01

The concentration of twelve trace elements in the water decoction of medicine food homology plants (MFHP) was determined by inductively coupled plasma-tandem mass spectrometry (ICP-MS/MS). Water decoctions of MFHP were analyzed directly using the MS/MS mode after acidification by 1% (v/v) nitric acid. The polyatomic interferences were eliminated by oxygen mass shift, oxygen on-mass, and ammonia mass shift. The accuracy of the method was verified by analysis of standard reference materials. This method was utilized to investigate the water decoction composition of 16 common Chinese MFHPs. The trace elements in the water decoctions of different MFHPs presented significantly different dissolution ratios. The dissolution ratio of V was the lowest (4.21%-14.86%), whereas Zn showed the highest dissolution ratio (24.87%-86.80%). In addition, the dissolution ratio of heavy metallic elements in most MFHP was equal to or was lower than 30%. Therefore, consumption of MHFP decoction could decrease the heavy metal intake associated with MFHP use and reduce the risk of heavy metal poisoning.

The TWIST1 oncogene is a direct target of hypoxia-inducible factor-2alpha.

PubMed

Gort, E H; van Haaften, G; Verlaan, I; Groot, A J; Plasterk, R H A; Shvarts, A; Suijkerbuijk, K P M; van Laar, T; van der Wall, E; Raman, V; van Diest, P J; Tijsterman, M; Vooijs, M

2008-03-06

Hypoxia-inducible factors (HIFs) are highly conserved transcription factors that play a crucial role in oxygen homeostasis. Intratumoral hypoxia and genetic alterations lead to HIF activity, which is a hallmark of solid cancer and is associated with poor clinical outcome. HIF activity is regulated by an evolutionary conserved mechanism involving oxygen-dependent HIFalpha protein degradation. To identify novel components of the HIF pathway, we performed a genome-wide RNA interference screen in Caenorhabditis elegans, to suppress HIF-dependent phenotypes, like egg-laying defects and hypoxia survival. In addition to hif-1 (HIFalpha) and aha-1 (HIFbeta), we identified hlh-8, gska-3 and spe-8. The hlh-8 gene is homologous to the human oncogene TWIST1. We show that TWIST1 expression in human cancer cells is enhanced by hypoxia in a HIF-2alpha-dependent manner. Furthermore, intronic hypoxia response elements of TWIST1 are regulated by HIF-2alpha, but not HIF-1alpha. These results identify TWIST1 as a direct target gene of HIF-2alpha, which may provide insight into the acquired metastatic capacity of hypoxic tumors.

The effect of trypan blue treatment on autofluorescence of fixed cells.

PubMed

Shilova, Olga N; Shilov, Evgeny S; Deyev, Sergey M

2017-09-01

Controlling background fluorescence remains an important challenge in flow cytometry, as autofluorescence can interfere with the detection of chromophores. Furthermore, experimental procedures can also affect cellular fluorescence in certain regions of the emission spectrum. In this work, the effects of fixation, permeabilization, and heating on cellular autofluorescence are analyzed in various spectral regions, along with the influence of trypan blue as a quenching dye for these treatments. The impact of these procedures on the staining of SK-BR-3 cells with a dim green fluorophore, a miniSOG (mini Singlet Oxygen Generator) flavoprotein in the form of the recombinant protein DARPin-miniSOG, is also evaluated. The data presented here indicate that fixation of certain types of cells leads to noticeable increase of the autofluorescence. Our results also suggest that trypan blue should be used as an autofluorescence quencher only with bright green emitters since it interferes with the fluorescent signal in a longer-wavelength region of the spectrum and as a result causes reduction of the signal from dim green fluorescent agents. © 2017 International Society for Advancement of Cytometry. © 2017 International Society for Advancement of Cytometry.

Genetic manipulation of isoprene emissions in poplar plants remodels the chloroplast proteome.

PubMed

Velikova, Violeta; Ghirardo, Andrea; Vanzo, Elisa; Merl, Juliane; Hauck, Stefanie M; Schnitzler, Jörg-Peter

2014-04-04

Biogenic isoprene (2-methyl-1,3-butadiene) improves the integrity and functionality of thylakoid membranes and scavenges reactive oxygen species (ROS) in plant tissue under stress conditions. On the basis of available physiological studies, we hypothesized that the suppression of isoprene production in the poplar plant by genetic engineering would cause changes in the chloroplast protein pattern, which in turn would compensate for changes in chloroplast functionality and overall plant performance under abiotic stress. To test this hypothesis, we used a stable isotope-coded protein-labeling technique in conjunction with polyacrylamide gel electrophoresis and liquid chromatography tandem mass spectrometry. We analyzed quantitative and qualitative changes in the chloroplast proteome of isoprene-emitting and non isoprene-emitting poplars. Here we demonstrate that suppression of isoprene synthase by RNA interference resulted in decreased levels of chloroplast proteins involved in photosynthesis and increased levels of histones, ribosomal proteins, and proteins related to metabolism. Overall, our results show that the absence of isoprene triggers a rearrangement of the chloroplast protein profile to minimize the negative stress effects resulting from the absence of isoprene. The present data strongly support the idea that isoprene improves/stabilizes thylakoid membrane structure and interferes with the production of ROS.

Methemoglobinemia secondary to topical benzocaine use in a lung transplant patient.

PubMed

LeClaire, Aimée C; Mullett, Timothy W; Jahania, M Salik; Flynn, Jeremy D

2005-02-01

To report a case of methemoglobinemia secondary to the administration of topical benzocaine spray in an anemic patient who had previously undergone a lung transplant. A 40-year-old white man with a past medical history significant for lung transplant acutely decompensated following oropharyngeal administration of topical benzocaine spray. Subsequent blood analysis revealed a methemoglobin concentration of 51.2%. Following the administration of a single dose of methylene blue 2 mg/kg intravenously, the patient's respiratory status dramatically improved and stabilized. Methemoglobinemia is a rare but potentially fatal condition that may be either acquired or congenital; however, the disorder is most commonly acquired secondary to exposure to oxidizing chemicals, which are often routinely prescribed medications, including benzocaine. Benzocaine can react with hemoglobin to form methemoglobin at a rate that exceeds reduction capabilities, which may result in oxygenation difficulty and respiratory distress. In severe or symptomatic methemoglobinemia, the treatment of choice is methylene blue. Application of the Naranjo probability scale established a highly probable relationship between topical benzocaine spray and methemoglobinemia and associated respiratory compromise. The risks of palliative use of topical benzocaine in patients with preexisting disorders that compromise oxygen delivery may outweigh any benefit. In our patient, anemia and lung disease increased his risk for clinically significant adverse respiratory events secondary to deficiencies or interferences in oxygen delivery. Topical benzocaine should be administered with caution and careful monitoring in such patient populations.

Electron Paramagnetic Resonance Oximetry as a Quantitative Method to Measure Cellular Respiration: A Consideration of Oxygen Diffusion Interference

PubMed Central

Presley, Tennille; Kuppusamy, Periannan; Zweier, Jay L.; Ilangovan, Govindasamy

2006-01-01

Electron paramagnetic resonance (EPR) oximetry is being widely used to measure the oxygen consumption of cells, mitochondria, and submitochondrial particles. However, further improvement of this technique, in terms of data analysis, is required to use it as a quantitative tool. Here, we present a new approach for quantitative analysis of cellular respiration using EPR oximetry. The course of oxygen consumption by cells in suspension has been observed to have three distinct zones: pO2-independent respiration at higher pO2 ranges, pO2-dependent respiration at low pO2 ranges, and a static equilibrium with no change in pO2 at very low pO2 values. The approach here enables one to comprehensively analyze all of the three zones together—where the progression of O2 diffusion zones around each cell, their overlap within time, and their potential impact on the measured pO2 data are considered. The obtained results agree with previously established methods such as high-resolution respirometry measurements. Additionally, it is also demonstrated how the diffusion limitations can depend on cell density and consumption rate. In conclusion, the new approach establishes a more accurate and meaningful model to evaluate the EPR oximetry data on cellular respiration to quantify related parameters using EPR oximetry. PMID:17012319

RNAi-Mediated Knockdown of Catalase Causes Cell Cycle Arrest in SL-1 Cells and Results in Low Survival Rate of Spodoptera litura (Fabricius)

PubMed Central

Hu, Meiying; Chen, Shaohua; Muhammad, Rizwan-ul-Haq; Dong, Xiaolin; Gong, Liang

2013-01-01

Deregulated reactive oxygen species (ROS) production can lead to the disruption of structural and functional integrity of cells as a consequence of reactive interaction between ROS and various biological components. Catalase (CAT) is a common enzyme existing in nearly all organisms exposed to oxygen, which decomposes harmful hydrogen peroxide, into water and oxygen. In this study, the full length sequence that encodes CAT-like protein from Spodoptera litura named siltCAT (GenBank accession number: JQ_663444) was cloned and characterized. Amino acid sequence alignment showed siltCAT shared relatively high conservation with other insect, especially the conserved residues which defined heme and NADPH orientation. Expression pattern analysis showed that siltCAT mRNA was mainly expressed in the fat body, midgut, cuticle and malpighian tube, and as well as over last instar larvae, pupa and adult stages. RNA interference was used to silence CAT gene in SL-1 cells and the fourth-instar stage of S. litura larvae respectively. Our results provided evidence that CAT knockdown induced ROS generation, cell cycle arrest and apoptosis in SL-1 cells. It also confirmed the decrease in survival rate because of increased ROS production in experimental groups injected with double-stranded RNA of CAT (dsCAT). This study implied that ROS scavenging by CAT is important for S. litura survival. PMID:23555693

Modeling biofiltration of VOC mixtures under steady-state conditions

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

Baltzis, B.C.; Wojdyla, S.M.; Zarook, S.M.

1997-06-01

Treatment of air streams contaminated with binary volatile organic compound (VOC) mixtures in classical biofilters under steady-state conditions of operation was described with a general mathematical model. The model accounts for potential kinetic interactions among the pollutants, effects of oxygen availability on biodegradation, and biomass diversification in the filter bed. While the effects of oxygen were always taken into account, two distinct cases were considered for the experimental model validation. The first involves kinetic interactions, but no biomass differentiation, used for describing data from biofiltration of benzene/toluene mixtures. The second case assumes that each pollutant is treated by a differentmore » type of biomass. Each biomass type is assumed to form separate patches of biofilm on the solid packing material, thus kinetic interference does not occur. This model was used for describing biofiltration of ethanol/butanol mixtures. Experiments were performed with classical biofilters packed with mixtures of peat moss and perlite (2:3, volume:volume). The model equations were solved through the use of computer codes based on the fourth-order Runge-Kutta technique for the gas-phase mass balances and the method of orthogonal collocation for the concentration profiles in the biofilms. Good agreement between model predictions and experimental data was found in almost all cases. Oxygen was found to be extremely important in the case of polar VOCs (ethanol/butanol).« less

Habitual exercise is associated with cognitive control and cognitive reappraisal success.

PubMed

Giles, Grace E; Cantelon, Julie A; Eddy, Marianna D; Brunyé, Tad T; Urry, Heather L; Mahoney, Caroline R; Kanarek, Robin B

2017-12-01

Habitual exercise is associated with enhanced domain-general cognitive control, such as inhibitory control, selective attention, and working memory, all of which rely on the frontal cortex. However, whether regular exercise is associated with more specific aspects of cognitive control, such as the cognitive control of emotion, remains relatively unexplored. The present study employed a correlational design to determine whether level of habitual exercise was related to performance on the Stroop test measuring selective attention and response inhibition, the cognitive reappraisal task measuring cognitive reappraisal success, and associated changes in prefrontal cortex (PFC) oxygenation using functional near-infrared spectroscopy. 74 individuals (24 men, 50 women, age 18-32 years) participated. Higher habitual physical activity was associated with lower Stroop interference (indicating greater inhibitory control) and enhanced cognitive reappraisal success. Higher habitual exercise was also associated with lower oxygenated hemoglobin (O 2 Hb) in the PFC in response to emotional information. However, NIRS data indicated that exercise was not associated with cognitive control-associated O 2 Hb in the PFC. Behaviorally, the findings support and extend the previous findings that habitual exercise relates to more successful cognitive control of neutral information and cognitive reappraisal of emotional information. Future research should explore whether habitual exercise exerts causal benefits to cognitive control and PFC oxygenation, as well as isolate specific cognitive control processes sensitive to change through habitual exercise.

Liquid Oxygen Propellant Densification Production and Performance Test Results With a Large-Scale Flight-Weight Propellant Tank for the X33 RLV

NASA Technical Reports Server (NTRS)

Tomsik, Thomas M.; Meyer, Michael L.

2010-01-01

This paper describes in-detail a test program that was initiated at the Glenn Research Center (GRC) involving the cryogenic densification of liquid oxygen (LO2). A large scale LO2 propellant densification system rated for 200 gpm and sized for the X-33 LO2 propellant tank, was designed, fabricated and tested at the GRC. Multiple objectives of the test program included validation of LO2 production unit hardware and characterization of densifier performance at design and transient conditions. First, performance data is presented for an initial series of LO2 densifier screening and check-out tests using densified liquid nitrogen. The second series of tests show performance data collected during LO2 densifier test operations with liquid oxygen as the densified product fluid. An overview of LO2 X-33 tanking operations and load tests with the 20,000 gallon Structural Test Article (STA) are described. Tank loading testing and the thermal stratification that occurs inside of a flight-weight launch vehicle propellant tank were investigated. These operations involved a closed-loop recirculation process of LO2 flow through the densifier and then back into the STA. Finally, in excess of 200,000 gallons of densified LO2 at 120 oR was produced with the propellant densification unit during the demonstration program, an achievement that s never been done before in the realm of large-scale cryogenic tests.

Direct and Indirect Effects of PM on the Cardiovascular System

PubMed Central

Nelin, Timothy D.; Joseph, Allan M.; Gorr, Matthew W.; Wold, Loren E.

2011-01-01

Human exposure to particulate matter (PM) elicits a variety of responses on the cardiovascular system through both direct and indirect pathways. Indirect effects of PM on the cardiovascular system are mediated through the autonomic nervous system, which controls heart rate variability, and inflammatory responses, which augment acute cardiovascular events and atherosclerosis. Recent research demonstrates that PM also affects the cardiovascular system directly by entry into the systemic circulation. This process causes myocardial dysfunction through mechanisms of reactive oxygen species production, calcium ion interference, and vascular dysfunction. In this review, we will present key evidence in both the direct and indirect pathways, suggest clinical applications of the current literature, and recommend directions for future research. PMID:22119171

Defect types and room temperature ferromagnetism in N-doped rutile TiO2 single crystals

NASA Astrophysics Data System (ADS)

Qin, Xiu-Bo; Li, Dong-Xiang; Li, Rui-Qin; Zhang, Peng; Li, Yu-Xiao; Wang, Bao-Yi

2014-06-01

The magnetic properties and defect types of virgin and N-doped TiO2 single crystals are probed by superconducting quantum interference device (SQUID), X-ray photoelectron spectroscopy (XPS), and positron annihilation analysis (PAS). Upon N doping, a twofold enhancement of the saturation magnetization is observed. Apparently, this enhancement is not related to an increase in oxygen vacancy, rather to unpaired 3d electrons in Ti3+, arising from titanium vacancies and the replacement of O with N atoms in the rutile structure. The production of titanium vacancies can enhance the room temperature ferromagnetism (RTFM), and substitution of O with N is the onset of ferromagnetism by inducing relatively strong ferromagnetic ordering.

Measurements of particle backscatter, extinction, and lidar ratio at 1064 nm with the rotational raman method in Polly-XT

NASA Astrophysics Data System (ADS)

Engelmann, Ronny; Haarig, Moritz; Baars, Holger; Ansmann, Albert; Kottas, Michael; Marinou, Eleni

2018-04-01

We replaced a 1064-nm interference filter of a Polly-XT lidar system by a 1058-nm filter to observe pure rotational Raman backscattering from atmospheric Nitrogen and Oxygen. Polly-XT is compact Raman lidar with a Nd:YAG laser (20 Hz, 200 mJ at 1064 nm) and a 30-cm telescope mirror which applies photomultipliers in photoncounting mode. We present the first measured signals at 1058 nm and the derived extinction profile from measurements aboard RV Polarstern and in Leipzig. In combination with another Polly-XT system we could also derive particle backscatter and lidar ratio profiles at 1064 nm.

On the role of Fe ions on magnetic properties of doped TiO2 nanoparticles

NASA Astrophysics Data System (ADS)

Tolea, F.; Grecu, M. N.; Kuncser, V.; Constantinescu, S. Gr.; Ghica, D.

2015-04-01

The role of iron doping on magnetic properties of hydrothermal anatase TiO2:57Fe (0-1 at. %) nanoparticles is investigated by combining superconducting quantum interference device magnetometry with Mössbauer and electron paramagnetic resonance techniques. The results on both as-prepared and thermally treated samples in reduced air atmosphere reveal complexity of magnetic interactions, in connection to certain iron ion electron configurations and defects (oxygen vacancies, F-center, and Ti3+ ions). The distribution of iron ions is predominantly at nanoparticle surface layers. Formation of weak ferromagnetic domains up to 380 K is mainly related to defects, supporting the bound magnetic polaron model.

Antiviral Defense Mechanisms in Honey Bees

PubMed Central

Brutscher, Laura M.; Daughenbaugh, Katie F.; Flenniken, Michelle L.

2015-01-01

Honey bees are significant pollinators of agricultural crops and other important plant species. High annual losses of honey bee colonies in North America and in some parts of Europe have profound ecological and economic implications. Colony losses have been attributed to multiple factors including RNA viruses, thus understanding bee antiviral defense mechanisms may result in the development of strategies that mitigate colony losses. Honey bee antiviral defense mechanisms include RNA-interference, pathogen-associated molecular pattern (PAMP) triggered signal transduction cascades, and reactive oxygen species generation. However, the relative importance of these and other pathways is largely uncharacterized. Herein we review the current understanding of honey bee antiviral defense mechanisms and suggest important avenues for future investigation. PMID:26273564

Bombesin, somatostatin, and related peptides: actions on thermoregulation

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

Brown, M.R.

1981-11-01

Bombesin acts within the anterior hypothalamic preoptic area to interfere with thermoregulation in the rat. The body temperature (T/sub b/) of animals receiving bombesin varies in parallel with ambient temperature (T/sub a/). Bombesin-induced reduction of T/sub b/ in animals at low T/sub a/ is associated with a marked reduction of oxygen consumption (Vo/sub 2/). Some somatostatin-related peptides, e.g., desAA/sup 1,2,4,5,12,13/ (D-Trp/sup 8/)-somatostatin (ODT8-SS), act within the brain to prevent bombesin-induced reduction of Vo/sub 2/ and T/sub b/. ODT8-SS also produces hyperthermia not associated with an increase in Vo/sub 2/.

Pressurization System Modeling for a Generic Bimese Two- Stage-to-Orbit Reusable Launch Vehicle

NASA Technical Reports Server (NTRS)

Mazurkivich, Pete; Chandler, Frank; Nguyen, Han

2005-01-01

A pressurization system model was developed for a generic bimese Two-Stage-to-orbit Reusable Launch Vehicle using a cross-feed system and operating with densified propellants. The model was based on the pressurization system model for a crossfeed subscale water test article and was validated with test data obtained from the test article. The model consists of the liquid oxygen and liquid hydrogen pressurization models, each made up of two submodels, Booster and Orbiter tank pressurization models. The tanks are controlled within a 0.2-psi band and pressurized on the ground with ambient helium and autogenously in flight with gaseous oxygen and gaseous hydrogen. A 15-psi pressure difference is maintained between the Booster and Orbiter tanks to ensure crossfeed check valve closure before Booster separation. The analysis uses an ascent trajectory generated for a generic bimese vehicle and a tank configuration based on the Space Shuttle External Tank. It determines the flow rates required to pressurize the tanks on the ground and in flight, and demonstrates the model's capability to analyze the pressurization system performance of a full-scale bimese vehicle with densified propellants.

Safety of capsule endoscopy using human body communication in patients with cardiac devices.

PubMed

Chung, Joo Won; Hwang, Hye Jin; Chung, Moon Jae; Park, Jeong Youp; Pak, Hui-Nam; Song, Si Young

2012-06-01

The MiroCam (IntroMedic, Ltd., Seoul, Korea) is a small-bowel capsule endoscope that uses human body communication to transmit data. The potential interactions between cardiac devices and the capsule endoscope are causes for concern, but no data are available for this matter. This clinical study was designed to evaluate the potential influence of the MiroCam capsules on cardiac devices. Patients with cardiac pacemakers or implantable cardiac defibrillators referred for evaluation of small bowel disease were prospectively enrolled in this study. Before capsule endoscopy, a cardiologist checked baseline electrocardiograms and functions of the cardiac devices. Cardiac rhythms were continuously monitored by 24-h telemetry during capsule endoscopy in the hospital. After completion of procedures, functions of the cardiac devices were checked again for interference. Images from the capsule endoscopy were reviewed and analyzed for technical problems. Six patients, three with pacemakers and three with implantable cardiac defibrillators, were included in the study. We identified no disturbances in the cardiac devices and no arrhythmias detected on telemetry monitoring during capsule endoscopy. No significant changes in the programmed parameters of the cardiac devices were noted after capsule endoscopy. There were no imaging disturbances from the cardiac devices on capsule endoscopy. Capsule endoscopy using human body communication to transmit data was safely performed in patients with cardiac pacemakers or implantable cardiac defibrillators. Images from the capsule endoscopy were not affected by cardiac devices. A further large-scale study is required to confirm the safety of capsule endoscopy with various types of cardiac devices.

Attractiveness of food and avoidance from contamination as conflicting stimuli to habitat selection by fish.

PubMed

Araújo, Cristiano V M; Rodríguez, Elizabeth N V; Salvatierra, David; Cedeño-Macias, Luis A; Vera-Vera, Victoria C; Moreira-Santos, Matilde; Ribeiro, Rui

2016-11-01

Habitat selection by fish is the outcome of a choice between different stimuli. Typically, the presence of food tends to attract organisms, while contamination triggers an avoidance response to prevent toxic effects. Given that both food and contaminants are not homogeneously distributed in the environment and that food can be available in contaminated zones, a key question has been put forward in the present study: does a higher availability of food in contaminated areas interfere in the avoidance response to contaminants regardless of the contamination level? Tilapia fry (Oreochromis sp.; 2.5-3.0 cm and 0.5-0.8 g) were exposed to two different effluent samples, diluted along a free-choice, non-forced exposure system simulating a contamination gradient. Initially, avoidance to the effluents was checked during a one hour exposure. Afterwards, food was added to the system so that the availability of food increased with the increase in the level of contamination, and the avoidance response to contamination was checked during another hour. Results clearly showed a concentration-dependent avoidance response for both effluents during the first hour (i.e., with no food). However, in presence of the food, the avoidance pattern was altered: organisms were propelled to intermittently move towards contaminated areas where food availability was higher. The incursions were taken regardless of the potential risk linked to the toxic effects. In conclusion, even when the risk of toxicity was imminent, tilapia fry were more intensively stimulated by the attractiveness of the food than by repulsion to the contamination. Copyright © 2016 Elsevier Ltd. All rights reserved.

CryoCart Restoration and Vacuum Pipe Construction

NASA Technical Reports Server (NTRS)

Chaidez, Mariana

2016-01-01

Propulsion systems that utilize hypergolic propellants have been used to power space vehicles since the beginning of the space program. Liquid methane and oxygen propulsion systems have emerged as an alternative and have proven to be more environmentally friendly. The incorporation of liquid methane/liquid oxygen (LOX) into the propulsion system has demonstrated an increase in engine performance, as well as a reduction in the volume, size and complexity of the system. Consequently, reducing the total mass of the vehicle which is a crucial aspect that is considered when planning space missions to both the Moon and Mars [1]. Project Morpheus has made significant advancements in liquid oxygen/liquid methane propulsion system technologies by incorporating a LOX/methane propulsion system to a vertical test bed. The vehicle consisted of a 5,000 lb main engine and four 20 lb remote control system (RCS) engines that utilize liquid methane/LOX as its propellant [1]. The vehicle completed successful flight testing at Kennedy Space Center in 2014 which marked the completion of the Morpheus project. Subsequent projects utilizing Morpheus' vertical test bed have been developed to make further advancements. One of the subsequent projects consisted of the addition of a smaller 2,000 lb main engine and a cold helium heat exchanger which would make it possible for a pressurant tank systems to be send to Mars or the Moon by significantly decreasing the overall mass and volume of the pressurant tank. The hot fire tests of the integrated system with the smaller main engine and cold helium heat exchanger were successful at sea level, but further studies are being conducted to better understand how the vertical test bed will behave under thermal-vacuum conditions. For this reason, the integrated vehicle will be taken to Plum Brook to be tested in a chamber capable of simulating these conditions. To ensure that the vehicle will function properly under vacuum conditions, testing will be first completed at the component level. During this process, the igniter of the main engine and the RCS thrusters will be tested under a vacuum. To complete the testing of the components, the test setup first needed to be finalized. The CryoCart is being used to feed the propellants to the test article. The CryoCart is a movable test set-up that was developed in 2009 to provide a mobile platform for testing oxygen/methane systems with hot-fire capability up to 100 lbf. The CryoCart consists of three different systems: Oxygen, Methane, and liquid Nitrogen. The Oxygen and Methane systems are placed into two different carts while the liquid nitrogen system is mainly located in the methane cart. Over the years, the CryoCart has been utilized for different projects and has undergone deterioration. For this reason, a new phase has been developed to rebuild it to working conditions once again. During my internship, I was aiding in the construction and restoration of the CryoCart. In the initial stages of the process, I updated the fluid and electrical schematics for the oxygen, methane, and test article systems. The original CryoCart consisted of an electrical panel that utilized electromechanical relays and a terminal to drive the igniter power and signal, as well as the main fuel and oxygen valves. This electrical panel connected to the CryoCart through various wire harnesses that could be found exiting from the CryoCart. First, it was determined how these harnesses connected to the electromechanical relays so that they worked correctly. Once the electrical system was understood, an alternative for the electromechanical relays and the Molex connectors used throughout the system was sought since these components can often prove to be unreliable. Solid State relays and MIL connectors were purchased to serve as replacements. Upon arrival of the parts, crimping and wiring was completed to install the new solid state relays and MIL connectors. During the replacement of the relays and connectors, system checks of the electrical system were ran to ensure that the system was working correctly. While completing system checks, the pressure transducers that were not functioning properly were also replaced and any issue with the wiring or signal was addressed. Once the electrical components were replaced, the restoration of the fluid system began. Parts of the tubing in the CryoCart had to be rebuild and often consisted of sizing, cutting, bending, filing, and sanding the tubing to prepare it to be flared. Many components had to be proof-tested to bring their certifications up to date, and several components had to be replaced. Various flex hoses, valves, and fittings were send to the Clean Lab because they were new, dirty, or had gone through proof-testing. Once they arrived from the cleaning lab they had to be put back to the system and leak checks and functional tests were conducted. In the Nitrogen system, the copper tubing located in the Oxygen cart was rebuild and Aerogel insulation was added to this section. A new gaseous nitrogen system was added to the CryoCart to purge the vacuum tube which will serve as the test chamber. Once the CryoCart was completed, construction of parts of the vacuum tube began. A flange was manufactured with welded fittings to hold the line of the vacuum pump as well as some extra fittings which will serve as extra inlets used to introduce fluid lines to the vacuum tube. Stress analysis was ran in this flange to ensure that it would not fail under vacuum conditions. The fluid lines leading from the air side of the vacuum to the test article were also constructed and added to the mount that had already been manufactured. Three different sets of tubing were constructed to accommodate the seven different RCS thruster and the main engine igniter that are going to be tested. Full electrical system checks were completed to ensure that all the wire harnesses and valves were functioning. Upon the completion of the CryoCart and the vacuum tube, hot fire testing for the RCS thrusters and the main engine igniter are going to begin. During this time any issues encountered with the engines or igniter will be addressed to ensure that the components function under vacuum conditions. After successful completion of testing, the vertical test bed, Morpheus, will be rebuilt and prepared to be sent to Plum Brook. In Plum Brook, the vehicle will be tested in the thermal-vacuum chamber to demonstrate that integrated lox-methane propulsion system operation in space-like conditions. This internship has allowed me the opportunity to gain valuable hands on experience and to develop skills that will aid in my education as well as in the workforce, while at the same time helping me determine that I would like to further pursue a career in propulsion engineering.

Monitoring the Relationship Between Changes in Cerebral Oxygenation and Electroencephalography Patterns During Cardiopulmonary Resuscitation: A Feasibility Study.

PubMed

Reagan, Elizabeth M; Nguyen, Robert T; Ravishankar, Shreyas T; Chabra, Vikram; Fuentes, Barbara; Spiegel, Rebecca; Parnia, Sam

2018-05-01

To date, no studies have examined real-time electroencephalography and cerebral oximetry monitoring during cardiopulmonary resuscitation as markers of the magnitude of global ischemia. We therefore sought to assess the feasibility of combining cerebral oximetry and electroencephalography in patients undergoing cardiopulmonary resuscitation and further to evaluate the electroencephalography patterns during cardiopulmonary resuscitation and their relationship with cerebral oxygenation as measured by cerebral oximetry. Extended case series of in-hospital and out-of-hospital cardiac arrest subjects. Tertiary Medical Center. Inclusion criteria: Convenience sample of 16 patients undergoing cardiopulmonary resuscitation during working hours between March 2014 and March 2015, greater than or equal to 18 years. A portable electroencephalography (Legacy; SedLine, Masimo, Irvine, CA) and cerebral oximetry (Equanox 7600; Nonin Medical, Plymouth, MN) system was used to measure cerebral resuscitation quality. Real-time regional cerebral oxygen saturation and electroencephalography readings were observed during cardiopulmonary resuscitation. The regional cerebral oxygen saturation values and electroencephalography patterns were not used to manage patients by clinical staff. In total, 428 electroencephalography images from 16 subjects were gathered; 40.7% (n = 174/428) were artifactual, therefore 59.3% (n = 254/428) were interpretable. All 16 subjects had interpretable images. Interpretable versus noninterpretable images were not related to a function of time or duration of cardiopulmonary resuscitation but to artifacts that were introduced to the raw data such as diaphoresis, muscle movement, or electrical interference. Interpretable data were able to be obtained immediately after application of the electrode strip. Seven distinct electroencephalography patterns were identified. Voltage suppression was commonest and seen during 78% of overall cardiopulmonary resuscitation time and in 15 of 16 subjects at some point during their cardiopulmonary resuscitation. Other observed patterns and their relative prevalence in relation to overall cardiopulmonary resuscitation time were theta background activity 8%, delta background activity 5%, bi frontotemporal periodic discharge 4%, burst suppression 2%, spike and wave 2%, and rhythmic delta activity 1%. Eight of 16 subjects had greater than one interpretable pattern. At regional cerebral oxygen saturation levels less than or equal to 19%, the observed electroencephalography pattern was exclusively voltage suppression. Delta background activity was only observed at regional cerebral oxygen saturation levels greater than 40%. The remaining patterns were observed throughout regional cerebral oxygen saturation categories above a threshold of 20%. Real-time monitoring of cerebral oxygenation and function during cardiac arrest resuscitation is feasible. Although voltage suppression is the commonest electroencephalography pattern, other distinct patterns exist that may correlate with the quality of cerebral resuscitation and oxygen delivery.

Analysis of task-evoked systemic interference in fNIRS measurements: insights from fMRI.

PubMed

Erdoğan, Sinem B; Yücel, Meryem A; Akın, Ata

2014-02-15

Functional near infrared spectroscopy (fNIRS) is a promising method for monitoring cerebral hemodynamics with a wide range of clinical applications. fNIRS signals are contaminated with systemic physiological interferences from both the brain and superficial tissues, resulting in a poor estimation of the task related neuronal activation. In this study, we use the anatomical resolution of functional magnetic resonance imaging (fMRI) to extract scalp and brain vascular signals separately and construct an optically weighted spatial average of the fMRI blood oxygen level-dependent (BOLD) signal for characterizing the scalp signal contribution to fNIRS measurements. We introduce an extended superficial signal regression (ESSR) method for canceling physiology-based systemic interference where the effects of cerebral and superficial systemic interference are treated separately. We apply and validate our method on the optically weighted BOLD signals, which are obtained by projecting the fMRI image onto optical measurement space by use of the optical forward problem. The performance of ESSR method in removing physiological artifacts is compared to i) a global signal regression (GSR) method and ii) a superficial signal regression (SSR) method. The retrieved signals from each method are compared with the neural signals that represent the 'ground truth' brain activation cleaned from cerebral systemic fluctuations. We report significant improvements in the recovery of task induced neural activation with the ESSR method when compared to the other two methods as reflected in the Pearson R(2) coefficient and mean square error (MSE) metrics (two tailed paired t-tests, p<0.05). The signal quality is enhanced most when ESSR method is applied with higher spatial localization, lower inter-trial variability, a clear canonical waveform and higher contrast-to-noise (CNR) improvement (60%). Our findings suggest that, during a cognitive task i) superficial scalp signal contribution to fNIRS signals varies significantly among different regions on the forehead and ii) using an average scalp measurement together with a local measure of superficial hemodynamics better accounts for the systemic interference inherent in the brain as well as superficial scalp tissue. We conclude that maximizing the overlap between the optical pathlength of superficial and deeper penetration measurements is of crucial importance for accurate recovery of the evoked hemodynamic response in fNIRS recordings. © 2013 Elsevier Inc. All rights reserved.

The Effects of Check-In, Check-Up, Check-Out for Students with Moderate Intellectual Disability during On- and Off-Site Vocational Training

ERIC Educational Resources Information Center

Boden, Lauren J.; Jolivette, Kristine; Alberto, Paul A.

2018-01-01

Check-in/check-out is a secondary-tier intervention within the positive behavior interventions and supports framework. Check-in/check-out pairs the use of an adult mentor with a daily progress report to help students meet individualized behavioral goals. This study adds to the research base by examining the effects of check-in, check-up, check-out…

A fiberoptic reflection oximeter.

PubMed

Landsman, M L; Knop, N; Kwant, G; Mook, G A; Zijlstra, W G

1978-03-20

A catheter tip oximeter is described consisting of a cardiac catheter containing optical fibers, and incandescent light source, a light detection unit and a processing unit. Half of the optical fibers guide the light to the blood at the tip of the catheter, the other half the backscattered (reflected) light to the detection unit. The detection unit contains a dichroic mirror, transmitting most of the light with lambda less than 800 nm and reflecting most of the light with lambda greater than 900 nm, thus splitting the light into two beams. These pass through interference filters with nominal wavelengths of 640 and 920 nm respectively, and are focused on silicium barrier layer photocells. The photocell signals are amplified and fed into a divider giving the ratio of measuring (R640) and compensating (R920) photocell output. The relationship between log R640/R920 and oxygen saturation is represented by a slightly curved line. The relation may be linearized by subtracting a constant voltage from the divided output before taking the logarithm. The slope of the calibration line is dependent on the total haemoglobin concentration. Nonetheless an average calibration line can be used between 70 and 100% oxygen saturation. For 78 measurements of pig blood samples in this range (haemoglobin concentration between 96 and 161 g.1(-1)), the standard deviation of the difference between the fiberoptic oximeter and a Radiometer OSM1 oxygen saturation meter was 1.9% saturation, for 152 samples over the entire saturation range the standard deviation of the difference was 3.1% saturation. The influence of the flow velocity of blood on the light reflection depends on wavelength as well as on oxygen saturation. Therefore, complete compensation for the flow effect is not possible by simple means.

The Effect of Polyhexanide, Octenidine Dihydrochloride, and Tea Tree Oil as Topical Antiseptic Agents on In Vivo Microcirculation of the Human Skin: A Noninvasive Quantitative Analysis.

PubMed

Rothenberger, Jens; Krauss, Sabrina; Tschumi, Christian; Rahmanian-Schwarz, Afshin; Schaller, Hans-Eberhard; Held, Manuel

2016-10-01

Antiseptics are indispensable for wound management and should focus not only on the efficacy in reducing the bacterial burden but also on how much they interfere in wound healing. In this study, the authors analyzed the direct effect of topical antiseptic agents on the microcirculation of intact human skin. The perfusion dynamics were assessed before, and 10 minutes after, the volunteers' fingers of the right hand (n = 20) were immersed in the following solutions - octenidine dihydrochloride, polyhexanide, tea tree oil, and saline solution. The authors used the Oxygen to See (LEA Medizintechnik GmbH, Giessen, Germany) diagnostic device for noninvasive determination of oxygen supply in microcirculation of blood perfused tissues, which combines a laser light to determine blood flow, as well as white light to determine hemoglobin oxygenation and the relative amount of hemoglobin. Tea tree oil (÷19.0%) (B. Braun Melsungen AG, Melsungen, Germany) and polyhexanide (÷12.4%) (Lavanid, Serag Wiessner GmbH, Naila, Germany) caused a significant increase in blood flow compared to the negative control (-25.6%). Octenidine (Octenisept, Schülke & Mayr GmbH, Norderstedt, Germany) showed a nonsignificant trend towards an increase in blood flow (÷7.2%). There were alterations in the values of hemoglobin oxygenation and the relative amount of hemoglobin, but these were not significant. Perfusion is an important factor for wound healing. Therefore, it might be advantageous if antiseptic agents would increase blood flow. Tea tree oil and polyhexanide have a positive effect on skin blood flow and can therefore be used especially in critically perfused wounds, provided the adverse reactions and the antimicrobial efficacy are comparable.

SMG-1 kinase attenuates mitochondrial ROS production but not cell respiration deficits during hyperoxia.

PubMed

Resseguie, Emily A; Brookes, Paul S; O'Reilly, Michael A

Supplemental oxygen (hyperoxia) used to treat individuals in respiratory distress causes cell injury by enhancing the production of toxic reactive oxygen species (ROS) and inhibiting mitochondrial respiration. The suppressor of morphogenesis of genitalia (SMG-1) kinase is activated during hyperoxia and promotes cell survival by phosphorylating the tumor suppressor p53 on serine 15. Here, we investigate whether SMG-1 and p53 blunt this vicious cycle of progressive ROS production and decline in mitochondrial respiration seen during hyperoxia. Human lung adenocarcinoma A549 and H1299 or colon carcinoma HCT116 cells were depleted of SMG-1, UPF-1, or p53 using RNA interference, and then exposed to room air (21% oxygen) or hyperoxia (95% oxygen). Immunoblotting was used to evaluate protein expression; a Seahorse Bioanalyzer was used to assess cellular respiration; and flow cytometry was used to evaluate fluorescence intensity of cells stained with mitochondrial or redox sensitive dyes. Hyperoxia increased mitochondrial and cytoplasmic ROS and suppressed mitochondrial respiration without changing mitochondrial mass or membrane potential. Depletion of SMG-1 or its cofactor, UPF1, significantly enhanced hyperoxia-induced mitochondrial but not cytosolic ROS abundance. They did not affect mitochondrial mass, membrane potential, or hyperoxia-induced deficits in mitochondrial respiration. Genetic depletion of p53 in A549 cells and ablation of the p53 gene in H1299 or HCT116 cells revealed that SMG-1 influences mitochondrial ROS through activation of p53. Our findings show that hyperoxia does not promote a vicious cycle of progressive mitochondrial ROS and dysfunction because SMG-1-p53 signaling attenuates production of mitochondrial ROS without preserving respiration. This suggests antioxidant therapies that blunt ROS production during hyperoxia may not suffice to restore cellular respiration.

Aerobic and anaerobic decomposition of Pistia stratiotes leachates from a tropical eutrophic reservoir (Barra Bonita, SP, Brazil).

PubMed

Bianchini, I; Silva, R H; Cunha-Santino, M B; Panhota, R S

2010-08-01

The present study discussed the kinetic aspects of leachate decomposition from an aquatic macrophyte, Pistia stratiotes L (water lettuce). This species was collected from Barra Bonita Reservoir located in the State of São Paulo (Brazil). Decomposition chambers were prepared with high molecular weight (HMW), low molecular weight (LMW) and integral (INT = HMW + LMW) dissolved organic matter (DOM) diluted with reservoir water. The samples were incubated at 20 degrees C, in darkness and under aerobic or anaerobic conditions. For 79 days, the concentrations of dissolved oxygen (DO) and organic carbon (OC) were measured. For calculating the deoxygenation coefficients (k d) and maximum oxygen consumption (COmax) the concentration of DO was integrated and fitted to a first-order kinetics model, which also applied to the depletion of OC concentrations. The COmax of INT incubations were 4% higher than the sum of HMW and LMW fractions. The deoxygenation coefficients, k d, had the same order of magnitude for all treatments. In relation to carbon decay, regardless of the availability of oxygen, the INT DOM also showed higher mineralisation. These results suggest that the leachate mineralisations are short-term processes; when the fractionation of the leachates occurs, the LMW had organic compounds with more accessibility for heterotrophic metabolism. On the other hand, when compared to INT DOM, the HMW and LMW were less consumed suggesting an interaction of the reactivity of the leachate. Our data suggest that in the Barra Bonita Reservoir the mineralisation of P. stratiotes leachates occurs through two competitive pathways (i.e. mineralisation of the labile compounds and formation of recalcitrant organic resources and their mineralisation) in which the oxygen availability and the molecular mass of DOM can interfere in the rates of reactions.

How do speakers resist distraction? Evidence from a taboo picture-word interference task.

PubMed

Dhooge, Elisah; Hartsuiker, Robert J

2011-07-01

Even in the presence of irrelevant stimuli, word production is a highly accurate and fluent process. But how do speakers prevent themselves from naming the wrong things? One possibility is that an attentional system inhibits task-irrelevant representations. Alternatively, a verbal self-monitoring system might check speech for accuracy and remove errors stemming from irrelevant information. Because self-monitoring is sensitive to social appropriateness, taboo errors should be intercepted more than neutral errors are. To prevent embarrassment, speakers might also speak more slowly when confronted with taboo distractors. Our results from two experiments are consistent with the self-monitoring account: Examining picture-naming speed (Experiment 1) and accuracy (Experiment 2), we found fewer naming errors but longer picture-naming latencies for pictures presented with taboo distractors than for pictures presented with neutral distractors. These results suggest that when intrusions of irrelevant words are highly undesirable, speakers do not simply inhibit these words: Rather, the language-production system adjusts itself to the context and filters out the undesirable words.

Description of Panel Method Code ANTARES

NASA Technical Reports Server (NTRS)

Ulbrich, Norbert; George, Mike (Technical Monitor)

2000-01-01

Panel method code ANTARES was developed to compute wall interference corrections in a rectangular wind tunnel. The code uses point doublets to represent blockage effects and line doublets to represent lifting effects of a wind tunnel model. Subsonic compressibility effects are modeled by applying the Prandtl-Glauert transformation. The closed wall, open jet, or perforated wall boundary condition may be assigned to a wall panel centroid. The tunnel walls can be represented by using up to 8000 panels. The accuracy of panel method code ANTARES was successfully investigated by comparing solutions for the closed wall and open jet boundary condition with corresponding Method of Images solutions. Fourier transform solutions of a two-dimensional wind tunnel flow field were used to check the application of the perforated wall boundary condition. Studies showed that the accuracy of panel method code ANTARES can be improved by increasing the total number of wall panels in the circumferential direction. It was also shown that the accuracy decreases with increasing free-stream Mach number of the wind tunnel flow field.

Designing a composite correlation filter based on iterative optimization of training images for distortion invariant face recognition

NASA Astrophysics Data System (ADS)

Wang, Q.; Elbouz, M.; Alfalou, A.; Brosseau, C.

2017-06-01

We present a novel method to optimize the discrimination ability and noise robustness of composite filters. This method is based on the iterative preprocessing of training images which can extract boundary and detailed feature information of authentic training faces, thereby improving the peak-to-correlation energy (PCE) ratio of authentic faces and to be immune to intra-class variance and noise interference. By adding the training images directly, one can obtain a composite template with high discrimination ability and robustness for face recognition task. The proposed composite correlation filter does not involve any complicated mathematical analysis and computation which are often required in the design of correlation algorithms. Simulation tests have been conducted to check the effectiveness and feasibility of our proposal. Moreover, to assess robustness of composite filters using receiver operating characteristic (ROC) curves, we devise a new method to count the true positive and false positive rates for which the difference between PCE and threshold is involved.

Microcontroller-based system for estimate of calcium in serum samples.

PubMed

Neelamegam, Periyaswmy; Jamaludeen, Abdul Sheriff; Ragendran, Annamalai; Murugrananthan, Krishanamoorthy

2010-01-01

In this study, a microcontroller-based control unit was designed and constructed for the estimation of serum calcium in blood samples. The proposed optoelectronic instrument used a red light emitting diode (LED) as a light source and photodiode as a sensor. The performance of the system was compared with that of a commercial instrument in measuring calcium ion. The quantitative analysis of calcium in a catalyst using arsenazo III as colorimetric reagent was used to test the device. The calibration curve for calcium binding with arsenazo III was drawn to check the range of linearity, which was between 0.1 to 4.5 mM L⁻¹. The limit of detection (LOD) is 0.05 mM L⁻¹. Absorbance changes over the pH range of 2-12 were determined to optimize the assay, with maximum absorption at pH 9.0. Interferences in absorbance from monovalent (K+ and Na+) and divalent (Mg²+) cations were also studied. The results show that the system works successfully.

KSC-08pd1685

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. – In Building 1555, workers check the movement of the wing toward the Pegasus XL launch vehicle. The Pegasus will launch NASA's Interstellar Boundary Explorer Mission, or IBEX, satellite from Kwajalein Island in the Marshall Islands, South Pacific. IBEX will make the first map of the boundary between the solar system and interstellar space. IBEX is the first mission designed to detect the edge of the solar system. As the solar wind from the sun flows out beyond Pluto, it collides with the material between the stars, forming a shock front. IBEX contains two neutral atom imagers designed to detect particles from the termination shock at the boundary between the solar system and interstellar space. IBEX also will study galactic cosmic rays, energetic particles from beyond the solar system that pose a health and safety hazard for humans exploring beyond Earth orbit. IBEX will make these observations from a highly elliptical orbit that takes it beyond the interference of the Earth's magnetosphere. Photo credit: NASA/Randy Beaudoin

CRISPRFinder: a web tool to identify clustered regularly interspaced short palindromic repeats.

PubMed

Grissa, Ibtissem; Vergnaud, Gilles; Pourcel, Christine

2007-07-01

Clustered regularly interspaced short palindromic repeats (CRISPRs) constitute a particular family of tandem repeats found in a wide range of prokaryotic genomes (half of eubacteria and almost all archaea). They consist of a succession of highly conserved regions (DR) varying in size from 23 to 47 bp, separated by similarly sized unique sequences (spacer) of usually viral origin. A CRISPR cluster is flanked on one side by an AT-rich sequence called the leader and assumed to be a transcriptional promoter. Recent studies suggest that this structure represents a putative RNA-interference-based immune system. Here we describe CRISPRFinder, a web service offering tools to (i) detect CRISPRs including the shortest ones (one or two motifs); (ii) define DRs and extract spacers; (iii) get the flanking sequences to determine the leader; (iv) blast spacers against Genbank database and (v) check if the DR is found elsewhere in prokaryotic sequenced genomes. CRISPRFinder is freely accessible at http://crispr.u-psud.fr/Server/CRISPRfinder.php.

Photon asymmetry measurements of overrightarrow{γ}p → π0 p for E_{γ}=320-650 MeV

NASA Astrophysics Data System (ADS)

Gardner, S.; Howdle, D.; Sikora, M. H.; Wunderlich, Y.; Abt, S.; Achenbach, P.; Afzal, F.; Aguar-Bartolome, P.; Ahmed, Z.; Annand, J. R. M.; Arends, H. J.; Bantawa, K.; Bashkanov, M.; Beck, R.; Biroth, M.; Borisov, N. S.; Braghieri, A.; Briscoe, W. J.; Cherepnya, S.; Cividini, F.; Costanza, S.; Collicott, C.; Demissie, B. T.; Denig, A.; Dieterle, M.; Downie, E. J.; Drexler, P.; Ferretti-Bondy, M. I.; Filkov, L. V.; Glazier, D. I.; Garni, S.; Gradl, W.; Günther, M.; Gurevich, G. M.; Hall Barrientos, P.; Hamilton, D.; Heid, E.; Hornidge, D.; Huber, G. M.; Jahn, O.; Jude, T. C.; Käser, A.; Kay, S.; Kashevarov, V. L.; Keshelashvili, I.; Kondratiev, R.; Korolija, M.; Krusche, B.; Linturi, J. M.; Lisin, V.; Livingston, K.; Lutterer, S.; MacGregor, I. J. D.; Macrae, R.; Mancell, J.; Manley, D. M.; Martel, P. P.; McGeorge, J. C.; McNicoll, E. F.; Middleton, D. G.; Miskimen, R.; Mullen, C.; Mushkarenkov, A.; Neganov, A. B.; Neiser, A.; Nikolaev, A.; Oberle, M.; Ostrick, M.; Owens, R. O.; Otte, P. B.; Oussena, B.; Paudyal, D.; Pedroni, P.; Polonski, A.; Prakhov, S.; Rajabi, A.; Robinson, J.; Rosner, G.; Rostomyan, T.; Sarty, A.; Schumann, S.; Sokhoyan, V.; Spieker, K.; Steffen, O.; Sfienti, C.; Strakovsky, I. I.; Strandberg, B.; Strub, Th.; Supek, I.; Tarbert, C. M.; Thiel, A.; Thiel, M.; Thomas, A.; Unverzagt, M.; Usov, Yu. A.; Watts, D. P.; Werthmüller, D.; Wettig, J.; Wolfes, M.; Witthauer, L.; Zana, L.

2016-11-01

High-statistics measurements of the photon asymmetry Σ for the overrightarrow{γ}p→π0p reaction have been made in the center-of-mass energy range W=1214-1450 MeV. The data were measured with the MAMI A2 real photon beam and Crystal Ball/TAPS detector systems in Mainz, Germany. The results significantly improve the existing world data and are shown to be in good agreement with previous measurements, and with the MAID, SAID, and Bonn-Gatchina predictions. We have also combined the photon asymmetry results with recent cross-section measurements from Mainz to calculate the profile functions, \\check{Σ} (= σ0Σ), and perform a moment analysis. Comparison with calculations from the Bonn-Gatchina model shows that the precision of the data is good enough to further constrain the higher partial waves, and there is an indication of interference between the very small F-waves and the N(1520) 3/2- and N(1535) 1/2- resonances.

Practical and quality-control aspects of multi-element analysis with quadrupole ICP-MS with special attention to urine and whole blood.

PubMed

De Boer, Jan L M; Ritsema, Rob; Piso, Sjoerd; Van Staden, Hans; Van Den Beld, Wilbert

2004-07-01

Two screening methods were developed for rapid analysis of a great number of urine and blood samples within the framework of an exposure check of the population after a firework explosion. A total of 56 elements was measured including major elements. Sample preparation consisted of simple dilution. Extensive quality controls were applied including element addition and the use of certified reference materials. Relevant results at levels similar to those found in the literature were obtained for Co, Ni, Cu, Zn, Sr, Cd, Sn, Sb, Ba, Tl, and Pb in urine and for the same elements except Ni, Sn, Sb, and Ba in blood. However, quadrupole ICP-MS has limitations, mainly related to spectral interferences, for the analysis of urine and blood, and these cause higher detection limits. The general aspects discussed in the paper give it wider applicability than just for analysis of blood and urine-it can for example be used in environmental analysis.

KSC-08pd1682

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. – In Building 1555, workers help guide a wing toward the Pegasus XL launch vehicle for a fit check. The Pegasus will launch NASA's Interstellar Boundary Explorer Mission, or IBEX, satellite from Kwajalein Island in the Marshall Islands, South Pacific. IBEX will make the first map of the boundary between the solar system and interstellar space. IBEX is the first mission designed to detect the edge of the solar system. As the solar wind from the sun flows out beyond Pluto, it collides with the material between the stars, forming a shock front. IBEX contains two neutral atom imagers designed to detect particles from the termination shock at the boundary between the solar system and interstellar space. IBEX also will study galactic cosmic rays, energetic particles from beyond the solar system that pose a health and safety hazard for humans exploring beyond Earth orbit. IBEX will make these observations from a highly elliptical orbit that takes it beyond the interference of the Earth's magnetosphere. Photo credit: NASA/Randy Beaudoin

KSC-08pd1677

NASA Image and Video Library

2008-04-28

VANDENBERG AIR FORCE BASE, Calif. – In Building 1555, the wings of the Pegasus XL launch vehicle are checked for fit. The Pegasus will launch NASA's Interstellar Boundary Explorer Mission, or IBEX, satellite from Kwajalein Island in the Marshall Islands, South Pacific. IBEX will make the first map of the boundary between the solar system and interstellar space. IBEX is the first mission designed to detect the edge of the solar system. As the solar wind from the sun flows out beyond Pluto, it collides with the material between the stars, forming a shock front. IBEX contains two neutral atom imagers designed to detect particles from the termination shock at the boundary between the solar system and interstellar space. IBEX also will study galactic cosmic rays, energetic particles from beyond the solar system that pose a health and safety hazard for humans exploring beyond Earth orbit. IBEX will make these observations from a highly elliptical orbit that takes it beyond the interference of the Earth's magnetosphere. Photo credit: NASA/Randy Beaudoin

KSC-08pd1686

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. – In Building 1555, workers check the fit of the wing on the Pegasus XL launch vehicle. The Pegasus will launch NASA's Interstellar Boundary Explorer Mission, or IBEX, satellite from Kwajalein Island in the Marshall Islands, South Pacific. IBEX will make the first map of the boundary between the solar system and interstellar space. IBEX is the first mission designed to detect the edge of the solar system. As the solar wind from the sun flows out beyond Pluto, it collides with the material between the stars, forming a shock front. IBEX contains two neutral atom imagers designed to detect particles from the termination shock at the boundary between the solar system and interstellar space. IBEX also will study galactic cosmic rays, energetic particles from beyond the solar system that pose a health and safety hazard for humans exploring beyond Earth orbit. IBEX will make these observations from a highly elliptical orbit that takes it beyond the interference of the Earth's magnetosphere. Photo credit: NASA/Randy Beaudoin

KSC-08pd1683

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. – In Building 1555, workers help guide a wing toward the Pegasus XL launch vehicle in the background for a fit check. The Pegasus will launch NASA's Interstellar Boundary Explorer Mission, or IBEX, satellite from Kwajalein Island in the Marshall Islands, South Pacific. IBEX will make the first map of the boundary between the solar system and interstellar space. IBEX is the first mission designed to detect the edge of the solar system. As the solar wind from the sun flows out beyond Pluto, it collides with the material between the stars, forming a shock front. IBEX contains two neutral atom imagers designed to detect particles from the termination shock at the boundary between the solar system and interstellar space. IBEX also will study galactic cosmic rays, energetic particles from beyond the solar system that pose a health and safety hazard for humans exploring beyond Earth orbit. IBEX will make these observations from a highly elliptical orbit that takes it beyond the interference of the Earth's magnetosphere. Photo credit: NASA/Randy Beaudoin

KSC-08pd1676

NASA Image and Video Library

2008-04-28

VANDENBERG AIR FORCE BASE, Calif. – In Building 1555, the wings of the Pegasus XL launch vehicle are checked for fit. The Pegasus will launch NASA's Interstellar Boundary Explorer Mission, or IBEX, satellite from Kwajalein Island in the Marshall Islands, South Pacific. IBEX will make the first map of the boundary between the solar system and interstellar space. IBEX is the first mission designed to detect the edge of the solar system. As the solar wind from the sun flows out beyond Pluto, it collides with the material between the stars, forming a shock front. IBEX contains two neutral atom imagers designed to detect particles from the termination shock at the boundary between the solar system and interstellar space. IBEX also will study galactic cosmic rays, energetic particles from beyond the solar system that pose a health and safety hazard for humans exploring beyond Earth orbit. IBEX will make these observations from a highly elliptical orbit that takes it beyond the interference of the Earth's magnetosphere. Photo credit: NASA/Randy Beaudoin

KSC-08pd1684

NASA Image and Video Library

2008-04-30

VANDENBERG AIR FORCE BASE, Calif. – In Building 1555, workers help guide a wing toward the Pegasus XL launch vehicle in the background for a fit check. The Pegasus will launch NASA's Interstellar Boundary Explorer Mission, or IBEX, satellite from Kwajalein Island in the Marshall Islands, South Pacific. IBEX will make the first map of the boundary between the solar system and interstellar space. IBEX is the first mission designed to detect the edge of the solar system. As the solar wind from the sun flows out beyond Pluto, it collides with the material between the stars, forming a shock front. IBEX contains two neutral atom imagers designed to detect particles from the termination shock at the boundary between the solar system and interstellar space. IBEX also will study galactic cosmic rays, energetic particles from beyond the solar system that pose a health and safety hazard for humans exploring beyond Earth orbit. IBEX will make these observations from a highly elliptical orbit that takes it beyond the interference of the Earth's magnetosphere. Photo credit: NASA/Randy Beaudoin

Calculation of wall effects of flow on a perforated wall with a code of surface singularities

NASA Astrophysics Data System (ADS)

Piat, J. F.

1994-07-01

Simplifying assumptions are inherent in the analytic method previously used for the determination of wall interferences on a model in a wind tunnel. To eliminate these assumptions, a new code based on the vortex lattice method was developed. It is suitable for processing any shape of test sections with limited areas of porous wall, the characteristic of which can be nonlinear. Calculation of wall effects in S3MA wind tunnel, whose test section is rectangular 0.78 m x 0.56 m, and fitted with two or four perforated walls, have been performed. Wall porosity factors have been adjusted to obtain the best fit between measured and computed pressure distributions on the test section walls. The code was checked by measuring nearly equal drag coefficients for a model tested in S3MA wind tunnel (after wall corrections) and in S2MA wind tunnel whose test section is seven times larger (negligible wall corrections).

Lidar/DIAL detection of bomb factories

NASA Astrophysics Data System (ADS)

Fiorani, Luca; Puiu, Adriana; Rosa, Olga; Palucci, Antonio

2013-10-01

One of the aims of the project BONAS (BOmb factory detection by Networks of Advanced Sensors) is to develop a lidar/DIAL (differential absorption lidar) to detect precursors employed in the manufacturing of improvised explosive devices (IEDs). At first, a spectroscopic study has been carried out: the infrared (IR) gas phase spectrum of acetone, one of the more important IED precursors, has been procured from available databases and checked with cell measurements. Then, the feasibility of a lidar/DIAL for the detection of acetone vapors has been shown in laboratory, simulating the experimental conditions of a field campaign. Eventually, having in mind measurements in a real scenario, an interferent study has been performed, looking for all known compounds that share with acetone IR absorption in the spectral band selected for its detection. Possible interfering species were investigated, simulating both urban and industrial atmospheres and limits of acetone detection in both environments were identified. This study confirmed that a lidar/DIAL can detect low concentration of acetone at considerable distances.

Signal processing and calibration procedures for in situ diode-laser absorption spectroscopy.

PubMed

Werle, P W; Mazzinghi, P; D'Amato, F; De Rosa, M; Maurer, K; Slemr, F

2004-07-01

Gas analyzers based on tunable diode-laser spectroscopy (TDLS) provide high sensitivity, fast response and highly specific in situ measurements of several atmospheric trace gases simultaneously. Under optimum conditions even a shot noise limited performance can be obtained. For field applications outside the laboratory practical limitations are important. At ambient mixing ratios below a few parts-per-billion spectrometers become more and more sensitive towards noise, interference, drift effects and background changes associated with low level signals. It is the purpose of this review to address some of the problems which are encountered at these low levels and to describe a signal processing strategy for trace gas monitoring and a concept for in situ system calibration applicable for tunable diode-laser spectroscopy. To meet the requirement of quality assurance for field measurements and monitoring applications, procedures to check the linearity according to International Standard Organization regulations are described and some measurements of calibration functions are presented and discussed.

Free-radicals and advanced chemistries involved in cell membrane organization influence oxygen diffusion and pathology treatment.

PubMed

Petersen, Richard C

2017-01-01

A breakthrough has been discovered in pathology chemistry related to increasing molecular structure that can interfere with oxygen diffusion through cell membranes. Free radicals can crosslink unsaturated low-viscosity fatty acid oils by chain-growth polymerization into more viscous liquids and even solids. Free radicals are released by mitochondria in response to intermittent hypoxia that can increase membrane molecular organization to reduce fluidity and oxygen diffusion in a possible continuing vicious cycle toward pathological disease. Alternate computational chemistry demonstrates molecular bond dynamics in free energy for cell membrane physiologic movements. Paired electrons in oxygen and nitrogen atoms require that oxygen bonds rotate and nitrogen bonds invert to seek polar nano-environments and hide from nonpolar nano-environments thus creating fluctuating instability at a nonpolar membrane and polar biologic fluid interface. Subsequent mechanomolecular movements provide free energy to increase diffusion by membrane transport of molecules and oxygen into the cell, cell-membrane signaling/recognition/defense in addition to protein movements for enzyme mixing. In other chemistry calcium bonds to membrane phosphates primarily on the outer plasma cell membrane surface to influence the membrane firing threshold for excitability and better seal out water permeation. Because calcium is an excellent metal conductor and membrane phosphate headgroups form a semiconductor at the biologic fluid interface, excess electrons released by mitochondria may have more broad dissipation potential by safe conduction through calcium atomic-sized circuits on the outer membrane surface. Regarding medical conditions, free radicals are known to produce pathology especially in age-related disease in addition to aging. Because cancer cell membranes develop extreme polymorphism that has been extensively followed in research, accentuated easily-visualized free-radical models are developed. In terms of treatment, use of vitamin nutrient supplements purported to be antioxidants that remove free radicals has not proved worthwhile in clinical trials presumably due to errors with early antioxidant measurements based on inaccurate colorimetry tests. However, newer covalent-bond shrinkage tests now provide accurate measurements for free-radical inhibitor hydroquinone and other molecules toward drug therapy.

Free-radicals and advanced chemistries involved in cell membrane organization influence oxygen diffusion and pathology treatment

PubMed Central

Petersen, Richard C

2017-01-01

A breakthrough has been discovered in pathology chemistry related to increasing molecular structure that can interfere with oxygen diffusion through cell membranes. Free radicals can crosslink unsaturated low-viscosity fatty acid oils by chain-growth polymerization into more viscous liquids and even solids. Free radicals are released by mitochondria in response to intermittent hypoxia that can increase membrane molecular organization to reduce fluidity and oxygen diffusion in a possible continuing vicious cycle toward pathological disease. Alternate computational chemistry demonstrates molecular bond dynamics in free energy for cell membrane physiologic movements. Paired electrons in oxygen and nitrogen atoms require that oxygen bonds rotate and nitrogen bonds invert to seek polar nano-environments and hide from nonpolar nano-environments thus creating fluctuating instability at a nonpolar membrane and polar biologic fluid interface. Subsequent mechanomolecular movements provide free energy to increase diffusion by membrane transport of molecules and oxygen into the cell, cell-membrane signaling/recognition/defense in addition to protein movements for enzyme mixing. In other chemistry calcium bonds to membrane phosphates primarily on the outer plasma cell membrane surface to influence the membrane firing threshold for excitability and better seal out water permeation. Because calcium is an excellent metal conductor and membrane phosphate headgroups form a semiconductor at the biologic fluid interface, excess electrons released by mitochondria may have more broad dissipation potential by safe conduction through calcium atomic-sized circuits on the outer membrane surface. Regarding medical conditions, free radicals are known to produce pathology especially in age-related disease in addition to aging. Because cancer cell membranes develop extreme polymorphism that has been extensively followed in research, accentuated easily-visualized free-radical models are developed. In terms of treatment, use of vitamin nutrient supplements purported to be antioxidants that remove free radicals has not proved worthwhile in clinical trials presumably due to errors with early antioxidant measurements based on inaccurate colorimetry tests. However, newer covalent-bond shrinkage tests now provide accurate measurements for free-radical inhibitor hydroquinone and other molecules toward drug therapy. PMID:29202036

Application of an eddy correlation system for the estimation of oxygen benthic fluxes in coastal permeable sediments impacted by submarine groundwater discharge

NASA Astrophysics Data System (ADS)

Donis, D.; Janssen, F.; Böttcher, M.; McGinnis, D.; Holtappels, M.; Wenzhöfer, F.

2012-04-01

Measurements of solute exchange across the sediment-water interface are crucial for marine environment monitoring. This interface has fundamental filter functions for the mass exchange between the seafloor and the water column. Being a non-invasive technique, the eddy correlation method, is probably the most accurate measurement for benthic fluxes. It does not interfere with local hydrodynamics and integrates over large areas, showing considerable advantages compared to traditional methods, i.e., microprofiles and benthic chambers. One of the most important exchange processes across the sediment-water interface is flux of oxygen, which is a predominant control factor for the biogeochemical activity in the sediment, carbon processing and the composition of benthic communities. The eddy correlation method performs simultaneous recordings of vertical velocities and oxygen concentrations at a specific distance to the seafloor and is becoming a standard method for resolving dissolved oxygen fluxes in aquatic systems. However, data treatment and interpretation, especially in shallow environments, is still challenging. One major concern in eddy correlation studies of coastal environments is how to consider surface wave motions that can dominate the turbulence range and that may bias flux calculations. A critical part of the data treatment thus is the removal of wave biases from the vertical velocity component, by separating the wave frequency oscillations (due to a tilted or miss-aligned sensor) from those containing meaningful flux contributions. Here we present in situ benthic oxygen exchange rates as determined by an eddy correlation system (ECS) and simultaneously deployed stirred benthic chambers. The study was carried out in a coastal ecosystem of the southern Baltic Sea that was impacted by low salinity groundwater discharge (Hel peninsula, Poland). Oxygen fluxes determined with ECS compared well with results from benthic chambers. Flux data and seepage rates are discussed in the context of groundwater and their importance for benthic biogeochemical processes in shallow sandy sediments. This work was supported by 7th framework EU ITN-project SENSEnet and BONUS+ project AMBER.

31 CFR 240.3 - Electronic checks and substitute checks.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Electronic checks and substitute... OF CHECKS DRAWN ON THE UNITED STATES TREASURY General Provisions § 240.3 Electronic checks and substitute checks. (a) Legal equivalence of electronic checks. An electronic check for which a presenting...

31 CFR 240.3 - Electronic checks and substitute checks.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 31 Money and Finance:Treasury 2 2011-07-01 2011-07-01 false Electronic checks and substitute... OF CHECKS DRAWN ON THE UNITED STATES TREASURY General Provisions § 240.3 Electronic checks and substitute checks. (a) Legal equivalence of electronic checks. An electronic check for which a presenting...

31 CFR 240.3 - Electronic checks and substitute checks.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 31 Money and Finance:Treasury 2 2012-07-01 2012-07-01 false Electronic checks and substitute... OF CHECKS DRAWN ON THE UNITED STATES TREASURY General Provisions § 240.3 Electronic checks and substitute checks. (a) Legal equivalence of electronic checks. An electronic check for which a presenting...

Attentional biases in body dysmorphic disorder (BDD): Eye-tracking using the emotional Stroop task.

PubMed

Toh, Wei Lin; Castle, David J; Rossell, Susan L

2017-04-01

Body dysmorphic disorder (BDD) is characterised by repetitive behaviours and/or mental acts occurring in response to preoccupations with perceived defects or flaws in physical appearance. This study aimed to examine attentional biases in BDD via the emotional Stroop task with two modifications: i) incorporating an eye-tracking paradigm, and ii) employing an obsessive-compulsive disorder (OCD) control group. Twenty-one BDD, 19 OCD and 21 HC participants, who were age-, sex-, and IQ-matched, were included. A card version of the emotional Stroop task was employed based on seven 10-word lists: (i) BDD-positive, (ii) BDD-negative, (iii) OCD-checking, (iv) OCD-washing, (v) general positive, (vi) general threat, and (vii) neutral (as baseline). Participants were asked to read aloud words and word colours consecutively, thereby yielding accuracy and latency scores. Eye-tracking parameters were also measured. Participants with BDD exhibited significant Stroop interference for BDD-negative words relative to HC participants, as shown by extended colour-naming latencies. In contrast, the OCD group did not exhibit Stroop interference for OCD-related nor general threat words. Only mild eye-tracking anomalies were uncovered in clinical groups. Inspection of individual scanning styles and fixation heat maps however revealed that viewing strategies adopted by clinical groups were generally disorganised, with avoidance of certain disorder-relevant words and considerable visual attention devoted to non-salient card regions. The operation of attentional biases to negative disorder-specific words was corroborated in BDD. Future replication studies using other paradigms are vital, given potential ambiguities inherent in emotional Stroop task interpretation. Copyright © 2017 Elsevier Inc. All rights reserved.

[Group intervention from a sensorimotor approach to reduce the intensity of chronic pain].

PubMed

Cantero-Braojos, Miguel Ángel; Cabrera-León, Andrés; López-González, María Angeles; Saúl, Luís Angel

2018-04-05

To assess the effectiveness, on people with chronic pain, of an intervention (Time In) designed to reduce pain and to improve psychological symptoms. A randomized clinical trial with a control group, taking three measurements over three months. Granada, Spain. A sample of 40 women aged 18 or older with a history (over 6 months) of chronic pain. The recruitment was in the Fibromyalgia Association of Granada, Spain (AGRAFIM). Time In is a sensorimotor intervention that combines biomechanical physiotherapeutic procedures and psychological strategies. A weekly session of 3h was planned and the total of the program was developed during five weeks. Independent variables: sociodemographic information, clinical history and Time In intervention. Dependent variables: Brief Pain Inventory (BPI-S), Short-Form Health Survey (SF-12), Symptom Check List-90-R (SCL-90-R) and Clinical Outcome in Routine Evaluation (CORE-OM). Significant differences were observed between control group and intervention group of most of the scales used in postintervention and follow up measurements. Thus, significantly lower mean scores were obtained in intensity, interference and areas of pain, quality of life, psychological symptoms and behavioural change. Similar results were observed on d Cohen scores. They were 'very important' on intensity of pain (d=-1.01, d=-0.97) and interference of pain (d=-0.85, d=-0.74), with an improvement percentage from 21% to 30%. Time In intervention reduces pain and improves psychological symptoms in patients with fibromyalgia; this results in a better quality of life. Copyright © 2018 The Authors. Publicado por Elsevier España, S.L.U. All rights reserved.

Contact area between femoral tunnel and interference screw in anatomic rectangular tunnel ACL reconstruction: a comparison of outside-in and trans-portal inside-out techniques.

PubMed

Hiramatsu, Kunihiko; Mae, Tatsuo; Tachibana, Yuta; Nakagawa, Shigeto; Shino, Konsei

2018-02-01

The purpose of this study was to compare the femoral tunnel length, the femoral graft bending angle at the femoral tunnel aperture, and the contact area between the femoral tunnel wall and an interference screw used for fixation in anatomic rectangular tunnel anterior cruciate ligament (ACL) reconstruction (ART ACLR). The study included 149 patients with primary ACL injury who underwent ART ACLR. Preoperatively, flexion angle of the index knee was checked under general anaesthesia. Those of less than 130° of passive flexion were assigned to the outside-in (OI) technique (78 patients), while the others to the trans-portal inside-out (TP) technique (71 patients). The patients underwent computed tomography with multiplanar reconstruction at 3-5 weeks post-operatively. Femoral tunnel length, graft bending angle, and contact ratio between the IFS and femoral tunnel were assessed. P < 0.05 was considered statistically significant. The femoral tunnel length in the OI technique was significantly longer than that in the TP technique (P < 0.001). The femoral graft bending angle in the OI technique was significantly more acute than that in the TP technique (P < 0.001). The contact ratio in the OI technique was significantly larger than that in the TP technique at every point in the femoral tunnel (P < 0.001). The OI technique resulted in a more acute femoral graft bending angle, longer mean femoral tunnel length, and larger contact ratio than the TP technique after ART ACLR. Retrospective comparative study, Level III.

Lithium promotes the production of reactive oxygen species via GSK-3β/TSC2/TOR signaling in the gill of zebrafish (Danio rerio).

PubMed

Liu, Dongwu; Gao, Lili; Zhang, Zhuangzhuang; Tao, Shiyi; Pang, Qiuxiang; Li, Ao; Deng, Hongkuan; Yu, Hairui

2018-03-01

In this study, the mechanism that lithium (Li) promotes the production of reactive oxygen species (ROS) via the glycogen synthase kinase-3β (GSK-3β)/tuberous sclerosis complex 2 (TSC2)/target of rapamycin (TOR) signaling was investigated in the gill of zebrafish (Danio rerio). After the zebrafish were treated by 25 and 50 mg/L Li + , the mRNA expression of GSK-3β and TSC2 was inhibited, but the expression of TOR was induced in the gill of zebrafish. The levels of hydrogen peroxide (H 2 O 2 ), superoxide anion (O 2 ·- ), and hydroxy radical (·OH) as well as the activity of superoxide dismutase (SOD) were increased, while the activities of catalase (CAT), glutathione peroxidase (GSH-PX), and peroxidase (POD) were decreased by 25 and 50 mg/L Li + treatments. In the ZF4 cells, the mRNA expression of GSK-3β and TSC2 was inhibited, but TOR expression was induced by 1, 5, and 10 mmol/L Li + treatments. To further confirm that lithium promoted ROS production via GSK-3β inhibition, GSK-3β RNA was interfered. It was found that the interference of GSK-3β RNA induced the TSC2/TOR signaling. The levels of H 2 O 2 , O 2 ·- , and ·OH were increased, but the activities of CAT, GSH-PX, and POD were decreased by GSK-3β RNA interference. In addition, lithium decreased the mitochondrial membrane potential (MMP) with Rhodamine-123 assay, but increased the levels of ROS by 2',7'-dichlorofluorescein diacetate (DCFH-DA) assay. The present results indicated that lithium promoted the ROS production through the GSK-3β/TSC2/TOR signaling in the gill of zebrafish. Copyright © 2017 Elsevier Ltd. All rights reserved.

The role of lead and excess oxygen in uranite

USGS Publications Warehouse

Berman, Robert Morris

1957-01-01

Analysed samples of uraninite were x-rayed, annealed by heating to 550° and 900° for various times in a nitrogen atmosphere, and x-rayed again. A decrease in unit cell size was generally observed. Calculations on the basis of Vegard's Law showed that the ordering of the interstitial oxygen ions could account for the decrease in cell size on annealing. The interstitial oxygens are not necessarily completely disordered before annealing. The degree of original disorder is dependent on the Rare Earth/ThO2 ratio; for high ThO2 and low rare earths, the interstitial oxygens are completely random. The degree of disorder apparently depends solely on the composition, and not on the past history of the sample; this implies that the oxygens are being continuously disordered, perhaps by alpha particles, to the equilibrium point determined by the R.E./ThO2 ratio. The degree of ordering of the interstitial oxygens also accounts for the difference in cell size between vein pitchblendes and those from the sediments of the Colorado Plateau. A study was also made of the degree of oxidation of uraninites. Although the uranium in many pegmatitic uraninites is more oxidized than can be obtained with the cubic UO2 phase in the laboratory, if the atoms proxying for uranium are calculated into the structural formula, and the lead is assumed to be radiogenic and calculated as original uranium, almost all pegmatitic uraninites fall into the range of interstitial oxygen content obtainable in the laboratory. This fact supports the auto-oxidation hypothesis. Many of the vein and sedimentary pitchblendes have compositions close to U3O8, although they are cubic. They may gave crystallized as U3O8, the decomposed to the cubic phase and a amorphous phase. This suggests that the stability range of U3O8 includes only very exceptional natural conditions. Vegard's Law calculations, studies of zoning in crystals, differential leaching, polished section textures, and other lines of evidence indicate that lead, including radiogenic lead, is exsolved from uraninite. A study of x-ray line intensities indicates that it exsolves as oriented monomolecular layers of orthohombic PbO (massicot) along cube planes in the uraninite, separating the uraninite crystallites so that the x-ray reflections interfere destructively to different degrees for different reflections.

30 CFR 57.11058 - Check-in, check-out system.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Check-in, check-out system. 57.11058 Section 57... Escapeways Escapeways-Underground Only § 57.11058 Check-in, check-out system. Each operator of an underground mine shall establish a check-in and check-out system which shall provide an accurate record of persons...

30 CFR 57.11058 - Check-in, check-out system.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Check-in, check-out system. 57.11058 Section 57... Escapeways Escapeways-Underground Only § 57.11058 Check-in, check-out system. Each operator of an underground mine shall establish a check-in and check-out system which shall provide an accurate record of persons...

30 CFR 57.11058 - Check-in, check-out system.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Check-in, check-out system. 57.11058 Section 57... Escapeways Escapeways-Underground Only § 57.11058 Check-in, check-out system. Each operator of an underground mine shall establish a check-in and check-out system which shall provide an accurate record of persons...

30 CFR 57.11058 - Check-in, check-out system.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Check-in, check-out system. 57.11058 Section 57... Escapeways Escapeways-Underground Only § 57.11058 Check-in, check-out system. Each operator of an underground mine shall establish a check-in and check-out system which shall provide an accurate record of persons...

30 CFR 57.11058 - Check-in, check-out system.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Check-in, check-out system. 57.11058 Section 57... Escapeways Escapeways-Underground Only § 57.11058 Check-in, check-out system. Each operator of an underground mine shall establish a check-in and check-out system which shall provide an accurate record of persons...

[Multimodal neuromonitoring in traumatic brain injury: contribution of PTiO2].

PubMed

Domínguez-Berrot, A M; González-Vaquero, M; Díaz-Domínguez, F J; Robla-Costales, J

2014-11-01

The main goal of exhaustively monitoring neurocritical patients is to avoid secondary injury. In the last few years we have witnessed an increase in brain monitoring tools, beyond the checking of intracranial and brain perfusion pressures. These widely used systems offer valuable but possibly insufficient information. Awareness and correction of brain hypoxia is a useful and interesting measure, not only for diagnostic purposes but also when deciding treatment, and to predict an outcome. In this context, it would be of great interest to use all the information gathered from brain oxygenation monitoring systems in conjunction with other available multimodal monitoring devices, in order to offer individualized treatment for each patient. Copyright © 2013 Elsevier España, S.L.U. and SEMICYUC. All rights reserved.

The development of new, low-cost perfluoroalkylether fluids with excellent low and high-temperature properties

NASA Technical Reports Server (NTRS)

Bierschenk, Thomas R.; Kawa, Hajimu; Juhlke, Timothy J.; Lagow, Richard J.

1988-01-01

A series of perfluoroalkylether (PFAE) fluids were synthesized by direct fluorination. Viscosity-temperature properties, oxidation stabilities, oxidation-corrosion properties, and lubricity were determined. The fluids were tested in the presence of common elastomers to check for compatibility. The bulk modulus of each was measured to determine if any could be used as nonflammable aircraft hydraulic fluid. It was determined that as the carbon to oxygen ratio decreases, the viscometric properties improve, the fluids may become poor lubricants, the bulk modulus increases, the surface tension increases, and the fluid density increases. The presence of difluoromethylene oxide units in the polymer does not seriously lower the oxidation and oxidation-corrosion stabilities as long as the difluoromethylene oxide units are separated by other units.

KSC-04PD-1810

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. In the Orbiter Processing Facility, from left, United Space Alliance workers Loyd Turner, Craig Meyer and Erik Visser prepare to conduct a fit check of an External Tank (ET) digital still camera in the right-hand liquid oxygen umbilical well on Space Shuttle Atlantis. NASA is pursuing use of the camera, beginning with the Shuttles Return To Flight, to obtain and downlink high-resolution images of the ET following separation of the ET from the orbiter after launch. The Kodak camera will record 24 images, at one frame per 1.5 seconds, on a flash memory card. After orbital insertion, the crew will transfer the images from the memory card to a laptop computer. The files will then be downloaded through the Ku-band system to the Mission Control Center in Houston for analysis.

KSC-04PD-1811

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. In the Orbiter Processing Facility, from left, United Space Alliance workers Loyd Turner, Craig Meyer and Erik Visser conduct a fit check of an External Tank (ET) digital still camera in the right-hand liquid oxygen umbilical well on Space Shuttle Atlantis. NASA is pursuing use of the camera, beginning with the Shuttles Return To Flight, to obtain and downlink high-resolution images of the ET following separation of the ET from the orbiter after launch. The Kodak camera will record 24 images, at one frame per 1.5 seconds, on a flash memory card. After orbital insertion, the crew will transfer the images from the memory card to a laptop computer. The files will then be downloaded through the Ku-band system to the Mission Control Center in Houston for analysis.

KSC-04pd1811

NASA Image and Video Library

2004-09-17

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, from left, United Space Alliance workers Loyd Turner, Craig Meyer and Erik Visser conduct a fit check of an External Tank (ET) digital still camera in the right-hand liquid oxygen umbilical well on Space Shuttle Atlantis. NASA is pursuing use of the camera, beginning with the Shuttle’s Return To Flight, to obtain and downlink high-resolution images of the ET following separation of the ET from the orbiter after launch. The Kodak camera will record 24 images, at one frame per 1.5 seconds, on a flash memory card. After orbital insertion, the crew will transfer the images from the memory card to a laptop computer. The files will then be downloaded through the Ku-band system to the Mission Control Center in Houston for analysis.

KSC-04pd1810

NASA Image and Video Library

2004-09-17

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, from left, United Space Alliance workers Loyd Turner, Craig Meyer and Erik Visser prepare to conduct a fit check of an External Tank (ET) digital still camera in the right-hand liquid oxygen umbilical well on Space Shuttle Atlantis. NASA is pursuing use of the camera, beginning with the Shuttle’s Return To Flight, to obtain and downlink high-resolution images of the ET following separation of the ET from the orbiter after launch. The Kodak camera will record 24 images, at one frame per 1.5 seconds, on a flash memory card. After orbital insertion, the crew will transfer the images from the memory card to a laptop computer. The files will then be downloaded through the Ku-band system to the Mission Control Center in Houston for analysis.

MRO Sequence Checking Tool

NASA Technical Reports Server (NTRS)

Fisher, Forest; Gladden, Roy; Khanampornpan, Teerapat

2008-01-01

The MRO Sequence Checking Tool program, mro_check, automates significant portions of the MRO (Mars Reconnaissance Orbiter) sequence checking procedure. Though MRO has similar checks to the ODY s (Mars Odyssey) Mega Check tool, the checks needed for MRO are unique to the MRO spacecraft. The MRO sequence checking tool automates the majority of the sequence validation procedure and check lists that are used to validate the sequences generated by MRO MPST (mission planning and sequencing team). The tool performs more than 50 different checks on the sequence. The automation varies from summarizing data about the sequence needed for visual verification of the sequence, to performing automated checks on the sequence and providing a report for each step. To allow for the addition of new checks as needed, this tool is built in a modular fashion.

Matrix interference evaluation employing GC and LC coupled to triple quadrupole tandem mass spectrometry.

PubMed

Uclés, S; Lozano, A; Sosa, A; Parrilla Vázquez, P; Valverde, A; Fernández-Alba, A R

2017-11-01

Gas and liquid chromatography coupled to triple quadrupole tandem mass spectrometry are currently the most powerful tools employed for the routine analysis of pesticide residues in food control laboratories. However, whatever the multiresidue extraction method, there will be a residual matrix effect making it difficult to identify/quantify some specific compounds in certain cases. Two main effects stand out: (i) co-elution with isobaric matrix interferents, which can be a major drawback for unequivocal identification, and therefore false negative detections, and (ii) signal suppression/enhancement, commonly called the "matrix effect", which may cause serious problems including inaccurate quantitation, low analyte detectability and increased method uncertainty. The aim of this analytical study is to provide a framework for evaluating the maximum expected errors associated with the matrix effects. The worst-case study contrived to give an estimation of the extreme errors caused by matrix effects when extraction/determination protocols are applied in routine multiresidue analysis. Twenty-five different blank matrices extracted with the four most common extraction methods used in routine analysis (citrate QuEChERS with/without PSA clean-up, ethyl acetate and the Dutch mini-Luke "NL" methods) were evaluated by both GC-QqQ-MS/MS and LC-QqQ-MS/MS. The results showed that the presence of matrix compounds with isobaric transitions to target pesticides was higher in GC than under LC in the experimental conditions tested. In a second study, the number of "potential" false negatives was evaluated. For that, ten matrices with higher percentages of natural interfering components were checked. Additionally, the results showed that for more than 90% of the cases, pesticide quantification was not affected by matrix-matched standard calibration when an interferent was kept constant along the calibration curve. The error in quantification depended on the concentration level. In a third study, the "matrix effect" was evaluated for each commodity/extraction method. Results showed 44% of cases with suppression/enhancement for LC and 93% of cases with enhancement for GC. Copyright © 2017 Elsevier B.V. All rights reserved.

Temperature measurements in metalized propellant combustion using hybrid fs/ps coherent anti-Stokes Raman scattering.

PubMed

Kearney, Sean P; Guildenbecher, Daniel R

2016-06-20

We apply ultrafast pure-rotational coherent anti-Stokes Raman scattering (CARS) for temperature and relative oxygen concentration measurements in the plume emanating from a burning, aluminized ammonium-perchlorate propellant strand. Combustion of these metal-based propellants is a particularly hostile environment for laser-based diagnostics, with intense background luminosity and scattering from hot metal particles as large as several hundred micrometers in diameter. CARS spectra that were previously obtained using nanosecond pulsed lasers in an aluminum-particle-seeded flame are examined and are determined to be severely impacted by nonresonant background, presumably as a result of the plasma formed by particulate-enhanced laser-induced breakdown. Introduction of femtosecond/picosecond (fs/ps) laser pulses improves CARS detection by providing time-gated elimination of strong nonresonant background interference. Single-laser-shot fs/ps CARS spectra were acquired from the burning propellant plume, with picosecond probe-pulse delays of 0 and 16 ps from the femtosecond pump and Stokes pulses. At zero delay, nonresonant background overwhelms the Raman-resonant spectroscopic features. Time-delayed probing results in the acquisition of background-free spectra that were successfully fit for temperature and relative oxygen content. Temperature probability densities and temperature/oxygen correlations were constructed from ensembles of several thousand single-laser-shot measurements with the CARS measurement volume positioned within 3 mm or less of the burning propellant surface. The results show that ultrafast CARS is a potentially enabling technology for probing harsh, particle-laden flame environments.

Chemiluminescence of BO{sub 2} to map the creation of thermal NO in flames

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

Maligne, D.; Cessou, A.; Stepowski, D.

The aim of this study is to detect and map the local conditions that generate thermal NO in flames. According to the Zeldovich mechanism, the formation of NO comes from the local conjunction of a high concentration of atomic oxygen and a temperature above a critical high level imposed by the high activation energy of the rate-limiting reaction. The green light emitted when a flame is seeded with boron salts is a chemiluminescence from the BO{sup *}{sub 2} that is chemically formed in its excited state when BO reacts with atomic oxygen. As the rate of this oxidation is alsomore » strongly increasing with temperature, the chemiluminescence of BO{sub 2} depends on the concentration of atomic oxygen and on the temperature in a way similar to the formation rate of thermal NO. This double analogy suggests the possibility of an experimental in situ simulation of the formation rate of thermal NO or at least the use of the chemiluminescence of BO{sub 2} to map the sites where thermal NO is being created. Spectroscopic experiments and comparisons with numerical simulations have been performed to test the feasibility of this technique in laminar premixed and diffusion methane/air flames. The agreement is good except in the burnt gases of fuel-rich flames. Imaging strategies with different spectral filters have been developed in the same flames to overcome the problem of interference from soot radiation in diffusion flames. (author)« less

Multimodal tissue perfusion imaging using multi-spectral and thermographic imaging systems applied on clinical data

NASA Astrophysics Data System (ADS)

Klaessens, John H. G. M.; Nelisse, Martin; Verdaasdonk, Rudolf M.; Noordmans, Herke Jan

2013-03-01

Clinical interventions can cause changes in tissue perfusion, oxygenation or temperature. Real-time imaging of these phenomena could be useful for surgical strategy or understanding of physiological regulation mechanisms. Two noncontact imaging techniques were applied for imaging of large tissue areas: LED based multispectral imaging (MSI, 17 different wavelengths 370 nm-880 nm) and thermal imaging (7.5 to 13.5 μm). Oxygenation concentration changes were calculated using different analyzing methods. The advantages of these methods are presented for stationary and dynamic applications. Concentration calculations of chromophores in tissue require right choices of wavelengths The effects of different wavelength choices for hemoglobin concentration calculations were studied in laboratory conditions and consequently applied in clinical studies. Corrections for interferences during the clinical registrations (ambient light fluctuations, tissue movements) were performed. The wavelength dependency of the algorithms were studied and wavelength sets with the best results will be presented. The multispectral and thermal imaging systems were applied during clinical intervention studies: reperfusion of tissue flap transplantation (ENT), effectiveness of local anesthetic block and during open brain surgery in patients with epileptic seizures. The LED multispectral imaging system successfully imaged the perfusion and oxygenation changes during clinical interventions. The thermal images show local heat distributions over tissue areas as a result of changes in tissue perfusion. Multispectral imaging and thermal imaging provide complementary information and are promising techniques for real-time diagnostics of physiological processes in medicine.

A new reference frame for astronomically-tuned Plio-Pleistocene climate variability derived from a benthic oxygen isotope splice of the Mediterranean

NASA Astrophysics Data System (ADS)

Lourens, L. J.; Ziegler, M.; Konijnendijk, T. Y. M.; Hilgen, F. J.; Bos, R.; Beekvelt, B.; van Loevezijn, A.; Collin, S.

2017-12-01

The astronomical theory of climate has revolutionized our understanding of past climate change and the development of highly accurate geologic time scales for the entire Cenozoic. Most of this understanding has come from the construction of astronomically tuned global ocean benthic foraminiferal oxygen isotope (δ18O) stacked record, derived by the international drilling operations of DSDP, ODP and IODP. The tuning includes fixed phase relationships between the obliquity and precession cycles and the inferred high-latitude climate, i.e. glacial-interglacial, response, which hark back to SPECMAP, using simple ice sheet models and a limited number of radiometric dates. This approach was largely implemented in the widely applied LR04 stack, though LR04 assumed shorter response times for the smaller ice caps during the Pliocene. In the past decades, an astronomically calibrated time scale for the Pliocene and Pleistocene of the Mediterranean has been developed, which has become the reference for the standard Geologic Time Scale. Typical of the Mediterranean marine sediments are the cyclic lithological alternations, reflecting the interference between obliquity and precession-paced low latitude climate variability, such as the African monsoon. Here we present the first benthic foraminiferal based oxygen isotope record of the Mediterranean reference scale, which strikingly mirrors the LR04. We will use this record to discuss the assumed open ocean glacial-interglacial related phase relations over the past 5.3 million years.

Compact Multi-Gas Monitor for Life Support Systems Control in Space: Evaluation Under Realistic Environmental Conditions

NASA Technical Reports Server (NTRS)

Alonso, Jesus Delgado; Phillips, Straun; Chullen, Cinda; Mendoza, Edgar

2014-01-01

Advanced space life support systems require lightweight, low-power, durable sensors for monitoring critical gas components. A luminescence-based optical flow-through cell to monitor carbon dioxide, oxygen, and humidity has been developed and was demonstrated using bench-top instrumentation under environmental conditions relevant to portable life support systems, including initially pure oxygen atmosphere, temperature range from 50 F to 150 F, and humidity from dry to 100% RH and under conditions of water condensation. This paper presents the most recent progress in the development of this sensor technology. Trace gas contaminants in a space suit, originating from hardware and material off-gassing and crew member metabolism, are from many chemical families. The result is a gas mix much more complex than the pure oxygen fed into the space suit, and this complexity may interfere with gas sensor readings. This paper presents an evaluation of optical sensor performance when exposed to the most significant trace gases reported to be found in space suits. A study of the calibration stability of the sensors is also presented. For that purpose, a profile of temperature, pressure, humidity, and gas composition for the duration of an EVA has been defined, and the performance of sensors operated repeatedly under those conditions has been studied. Finally, this paper presents the first compact readout unit for these optical sensors, designed for the volume, power, and weight restrictions of a PLSS.

Temperature measurements in metalized propellant combustion using hybrid fs/ps coherent anti-Stokes Raman scattering

DOE PAGES

Kearney, Sean P.; Guildenbecher, Daniel R.

2016-06-20

We apply ultrafast pure-rotational coherent anti-Stokes Raman scattering (CARS) for temperature and relative oxygen concentration measurements in the plume emanating from a burning, aluminized ammonium-perchlorate propellant strand. Combustion of these metal-based propellants is a particularly hostile environment for laser-based diagnostics, with intense background luminosity and scattering from hot metal particles as large as several hundred micrometers in diameter. CARS spectra that were previously obtained using nanosecond pulsed lasers in an aluminum-particle-seeded flame are examined and are determined to be severely impacted by nonresonant background, presumably as a result of the plasma formed by particulate-enhanced laser-induced breakdown. Introduction of femtosecond/picosecond (fs/ps)more » laser pulses improves CARS detection by providing time-gated elimination of strong nonresonant background interference. Single-laser-shot fs/ps CARS spectra were acquired from the burning propellant plume, with picosecond probe-pulse delays of 0 and 16 ps from the femtosecond pump and Stokes pulses. At zero delay, nonresonant background overwhelms the Raman-resonant spectroscopic features. Time-delayed probing results in the acquisition of background-free spectra that were successfully fit for temperature and relative oxygen content. Temperature probability densities and temperature/oxygen correlations were constructed from ensembles of several thousand single-laser-shot measurements with the CARS measurement volume positioned within 3 mm or less of the burning propellant surface. Lastly, the results show that ultrafast CARS is a potentially enabling technology for probing harsh, particle-laden flame environments.« less

Temperature measurements in metalized propellant combustion using hybrid fs/ps coherent anti-Stokes Raman scattering

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

Kearney, Sean P.; Guildenbecher, Daniel R.

We apply ultrafast pure-rotational coherent anti-Stokes Raman scattering (CARS) for temperature and relative oxygen concentration measurements in the plume emanating from a burning, aluminized ammonium-perchlorate propellant strand. Combustion of these metal-based propellants is a particularly hostile environment for laser-based diagnostics, with intense background luminosity and scattering from hot metal particles as large as several hundred micrometers in diameter. CARS spectra that were previously obtained using nanosecond pulsed lasers in an aluminum-particle-seeded flame are examined and are determined to be severely impacted by nonresonant background, presumably as a result of the plasma formed by particulate-enhanced laser-induced breakdown. Introduction of femtosecond/picosecond (fs/ps)more » laser pulses improves CARS detection by providing time-gated elimination of strong nonresonant background interference. Single-laser-shot fs/ps CARS spectra were acquired from the burning propellant plume, with picosecond probe-pulse delays of 0 and 16 ps from the femtosecond pump and Stokes pulses. At zero delay, nonresonant background overwhelms the Raman-resonant spectroscopic features. Time-delayed probing results in the acquisition of background-free spectra that were successfully fit for temperature and relative oxygen content. Temperature probability densities and temperature/oxygen correlations were constructed from ensembles of several thousand single-laser-shot measurements with the CARS measurement volume positioned within 3 mm or less of the burning propellant surface. Lastly, the results show that ultrafast CARS is a potentially enabling technology for probing harsh, particle-laden flame environments.« less

Measurement and modeling of ozone and nitrogen oxides produced by laser breakdown in oxygen-nitrogen atmospheres.

PubMed

Gornushkin, Igor B; Stevenson, Chris L; Galbács, Gábor; Smith, Ben W; Winefordner, James D

2003-11-01

The production of ozone nad nitrogen oxides was studied during multiple laser breakdown in oxygen-nitrogen mixtures at atmospheric pressure. About 2000 laser shots at 10(10) W cm-2 were delivered into a sealed reaction chamber. The chamber with a long capillary was designed to measure absorption of O3, NO, and NO2 as a function of the number of laser shots. The light source for absorption measurements was the continuum radiation emitted by the plasma during the first 0.2 microsecond of its evolution. A kinetic model was developed that encompassed the principal chemical reactions between the major atmospheric components and the products of laser breakdown. In the model, the laser plasma was treated as a source of nitric oxide and atomic oxygen, whose rates of production were calculated using measured absorption by NO, NO2, and O3. The calculated concentration profiles for NO, NO2, and O3 were in good agreement with measured profiles over a time scale of 0-200 s. The steady-state concentration of ozone was measured in a flow cell in air. For a single breakdown in air, the estimated steady-state yield of ozone was 2 x 10(12) molecules, which agreed with the model prediction. This study can be of importance for general understanding of laser plasma chemistry and for elucidating the nature of spectral interferences and matrix effects that may take place in applied spectrochemical analysis.

Factors Affecting Wound Healing

PubMed Central

Guo, S.; DiPietro, L.A.

2010-01-01

Wound healing, as a normal biological process in the human body, is achieved through four precisely and highly programmed phases: hemostasis, inflammation, proliferation, and remodeling. For a wound to heal successfully, all four phases must occur in the proper sequence and time frame. Many factors can interfere with one or more phases of this process, thus causing improper or impaired wound healing. This article reviews the recent literature on the most significant factors that affect cutaneous wound healing and the potential cellular and/or molecular mechanisms involved. The factors discussed include oxygenation, infection, age and sex hormones, stress, diabetes, obesity, medications, alcoholism, smoking, and nutrition. A better understanding of the influence of these factors on repair may lead to therapeutics that improve wound healing and resolve impaired wounds. PMID:20139336

Validation of the design of a high resolution all-reflection Michelson interferometer for atmospheric spectroscopy

NASA Astrophysics Data System (ADS)

Carlson, Scott M.

1993-06-01

The design of a high resolution plane grating all-reflection Michelson interferometer for ionospheric spectroscopy was analyzed using ray tracing techniques. This interferometer produces an interference pattern whose spatial frequency is wavelength dependent. The instrument is intended for remote observations of the atomic oxygen triplet emission line profile at 1304 A in the thermosphere from sounding rocket or satellite platforms. The device was modeled using the PC-based ray tracing application, DART, and results analyzed through fourier techniques using the PC with Windows version of the Interactive Data Language (IDL). Through these methods, instrument resolution, resolving power, and bandpass were determined. An analysis of the effects of aperture size and shape on instrument performance was also conducted.

Factors affecting wound healing.

PubMed

Guo, S; Dipietro, L A

2010-03-01

Wound healing, as a normal biological process in the human body, is achieved through four precisely and highly programmed phases: hemostasis, inflammation, proliferation, and remodeling. For a wound to heal successfully, all four phases must occur in the proper sequence and time frame. Many factors can interfere with one or more phases of this process, thus causing improper or impaired wound healing. This article reviews the recent literature on the most significant factors that affect cutaneous wound healing and the potential cellular and/or molecular mechanisms involved. The factors discussed include oxygenation, infection, age and sex hormones, stress, diabetes, obesity, medications, alcoholism, smoking, and nutrition. A better understanding of the influence of these factors on repair may lead to therapeutics that improve wound healing and resolve impaired wounds.

30 CFR 77.902-2 - Approved ground check systems not employing pilot check wires.

Code of Federal Regulations, 2010 CFR

2010-07-01

... pilot check wires. 77.902-2 Section 77.902-2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... Approved ground check systems not employing pilot check wires. Ground check systems not employing pilot check wires shall be approved by the Secretary only after it has been determined that the system...

30 CFR 77.902-2 - Approved ground check systems not employing pilot check wires.

Code of Federal Regulations, 2011 CFR

2011-07-01

... pilot check wires. 77.902-2 Section 77.902-2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... Approved ground check systems not employing pilot check wires. Ground check systems not employing pilot check wires shall be approved by the Secretary only after it has been determined that the system...

Interface Circuits for Self-Checking Microprocessors

NASA Technical Reports Server (NTRS)

Rennels, D. A.; Chandramouli, R.

1986-01-01

Fault-tolerant-microcomputer concept based on enhancing "simple" computer with redundancy and self-checking logic circuits detect hardware faults. Interface and checking logic and redundant processors confer on 16-bit microcomputer ability to check itself for hardware faults. Checking circuitry also checks itself. Concept of self-checking complementary pairs (SCCP's) employed throughout ICL unit.

30 CFR 77.902-2 - Approved ground check systems not employing pilot check wires.

Code of Federal Regulations, 2012 CFR

2012-07-01

... pilot check wires. 77.902-2 Section 77.902-2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... Approved ground check systems not employing pilot check wires. Ground check systems not employing pilot check wires shall be approved by the Secretary only after it has been determined that the system...

30 CFR 77.902-2 - Approved ground check systems not employing pilot check wires.

Code of Federal Regulations, 2013 CFR

2013-07-01

... pilot check wires. 77.902-2 Section 77.902-2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... Approved ground check systems not employing pilot check wires. Ground check systems not employing pilot check wires shall be approved by the Secretary only after it has been determined that the system...

30 CFR 77.902-2 - Approved ground check systems not employing pilot check wires.

Code of Federal Regulations, 2014 CFR

2014-07-01

... pilot check wires. 77.902-2 Section 77.902-2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... Approved ground check systems not employing pilot check wires. Ground check systems not employing pilot check wires shall be approved by the Secretary only after it has been determined that the system...

RNA interference targeting cytosolic NADP(+)-dependent isocitrate dehydrogenase exerts anti-obesity effect in vitro and in vivo.

PubMed

Nam, Woo Suk; Park, Kwon Moo; Park, Jeen-Woo

2012-08-01

A metabolic abnormality in lipid biosynthesis is frequently associated with obesity and hyperlipidemia. Nicotinamide adenine dinucleotide phosphate-oxidase (NADPH) is an essential reducing equivalent for numerous enzymes required in fat and cholesterol biosynthesis. Cytosolic NADP(+)-dependent isocitrate dehydrogenase (IDPc) has been proposed as a key enzyme for supplying cytosolic NADPH. We report here that knockdown of IDPc expression by Ribonucleic acid (RNA) interference (RNAi) inhibited adipocyte differentiation and lipogenesis in 3T3-L1 preadipocytes and mice. Attenuated IDPc expression by IDPc small interfering RNA (siRNA) resulted in a reduction of differentiation and triglyceride level and adipogenic protein expression as well as suppression of glucose uptake in cultured adipocytes. In addition, the attenuation of Nox activity and Reactive oxygen species (ROS) generation accompanied with knockdown of IDPc was associated with inhibition of adipogenesis and lipogenesis. The loss of body weight and the reduction of triglyceride level were also observed in diet-induced obese mice transduced with IDPc short-hairpin (shRNA). Taken together, the inhibiting effect of RNAi targeting IDPc on adipogenesis and lipid biosynthesis is considered to be of therapeutic value in the treatment and prevention of obesity and obesity-associated metabolic syndrome. © 2012 Elsevier B.V. All rights reserved.

"Off-on" red-emitting fluorescent probes with large Stokes shifts for nitric oxide imaging in living cells.

PubMed

Chen, Jian-Bo; Zhang, Hui-Xian; Guo, Xiao-Feng; Wang, Hong; Zhang, Hua-Shan

2013-09-01

Fluorescent probes with larger Stokes shifts in the far-visible and near-infrared spectral region (600-900 nm) are more superior for cellular imaging and biological analysis due to avoiding light scattering interference, reducing autofluorescence from biological sample and encouraging deeper tissue penetration in vivo imaging. In this work, two bis-methoxyphenyl-BODIPY fluorescent probes for the detection of nitric oxide (NO) have been firstly synthesized. Under physiological conditions, these probes can react with NO to form the corresponding triazoles with 250- and 70-fold turn-on fluorescence emitting at 590 and 620 nm, respectively. Moreover, the triazole forms of these probes have large Stokes shifts of 38 nm, in contrast to 10 nm of existing BODIPY probes for NO. Excellent selectivity has been observed against other reactive oxygen/nitrogen species, ascorbic acid and biological matrix. After the evaluation of MTT assay, new fluorescent probes have been successfully applied to fluorescence imaging of NO released from RAW 264.7 macrophages by co-stimulation of lipopolysaccharide and interferon-γ. The experimental results indicate that our fluorescent probes can be powerful candidates for fluorescence imaging of NO due to the low background interference and high detection sensitivity.

LSU network hubs integrate abiotic and biotic stress responses via interaction with the superoxide dismutase FSD2

PubMed Central

Garcia-Molina, Antoni; Altmann, Melina; Alkofer, Angela; Epple, Petra M.; Dangl, Jeffery L.

2017-01-01

Abstract In natural environments, plants often experience different stresses simultaneously, and adverse abiotic conditions can weaken the plant immune system. Interactome mapping revealed that the LOW SULPHUR UPREGULATED (LSU) proteins are hubs in an Arabidopsis protein interaction network that are targeted by virulence effectors from evolutionarily diverse pathogens. Here we show that LSU proteins are up-regulated in several abiotic and biotic stress conditions, such as nutrient depletion or salt stress, by both transcriptional and post-translational mechanisms. Interference with LSU expression prevents chloroplastic reactive oxygen species (ROS) production and proper stomatal closure during sulphur stress. We demonstrate that LSU1 interacts with the chloroplastic superoxide dismutase FSD2 and stimulates its enzymatic activity in vivo and in vitro. Pseudomonas syringae virulence effectors interfere with this interaction and preclude re-localization of LSU1 to chloroplasts. We demonstrate that reduced LSU levels cause a moderately enhanced disease susceptibility in plants exposed to abiotic stresses such as nutrient deficiency, high salinity, or heavy metal toxicity, whereas LSU1 overexpression confers significant disease resistance in several of these conditions. Our data suggest that the network hub LSU1 plays an important role in co-ordinating plant immune responses across a spectrum of abiotic stress conditions. PMID:28207043

Nitroxidative chemistry interferes with fluorescent probe chemistry: implications for nitric oxide detection using 2,3-diaminonaphthalene.

PubMed

Hu, Teh-Min; Chiu, Shih-Jiuan; Hsu, Yu-Ming

2014-08-22

Simultaneous production of nitric oxide (NO) and superoxide generates peroxynitrite and causes nitroxidative stress. The fluorometric method for NO detection is based on the formation of a fluorescent product from the reaction of a nonfluorescent probe molecule with NO-derived nitrosating species. Here, we present an example of how nitroxidative chemistry could interact with fluorescent probe chemistry. 2,3-Naphthotriazole (NAT) is the NO-derived fluorescent product of 2,3-diaminonaphthalene (DAN), a commonly used NO-detecting molecule. We show that NO/superoxide cogeneration, and particularly peroxynitrite, mediates the chemical decomposition of NAT. Moreover, the extent of NAT decomposition depends on the relative fluxes of NO and superoxide; the maximum effect being reached at almost equivalent generation rates for both radicals. The rate constant for the reaction of NAT with peroxynitrite was determined to be 2.2×10(3)M(-1)s(-1). Further, various peroxynitrite scavengers were shown to effectively inhibit NO/superoxide- and peroxynitrite-mediated decomposition of NAT. Taken together, the present study suggests that the interference of a fluorometric NO assay can be originated from the interaction between the final fluorescent product and the formed reactive nitrogen and oxygen species. Copyright © 2014 Elsevier Inc. All rights reserved.

A new approach to light up the application of semiconductor nanomaterials for photoelectrochemical biosensors: using self-operating photocathode as a highly selective enzyme sensor.

PubMed

Wang, Guang-Li; Liu, Kang-Li; Dong, Yu-Ming; Wu, Xiu-Ming; Li, Zai-Jun; Zhang, Chi

2014-12-15

Due to the intrinsic hole oxidation reaction occurred on the photoanode surface, currently developed photoelectrochemical biosensors suffer from the interference from coexisting reductive species (acting as electron donor) and a novel design strategy of photoelectrode for photoelectrochemical detection is urgently required. In this paper, a self-operating photocathode based on CdS quantum dots sensitized three-dimensional (3D) nanoporous NiO was designed and created, which showed highly selective and reversible response to dissolved oxygen (acting as electron acceptor) in the electrolyte solution. Using glucose oxidase (GOD) as a biocatalyst, a novel photoelectrochemical sensor for glucose was developed. The commonly encountered interferents such as H2O2, ascorbic acid (AA), cysteine (Cys), dopamine (DA), etc., almost had no effect for the cathodic photocurrent of the 3D NiO/CdS electrode, though these substances were proved to greatly influence the photocurrent of photoanodes, which indicated greatly improved selectivity of the method. The method was applied to detect glucose in real samples including serum and glucose injections with satisfactory results. This study could provide a new train of thought on designing of self-operating photocathode in photoelectrochemical sensing, promoting the application of semiconductor nanomaterials in photoelectrochemistry. Copyright © 2014 Elsevier B.V. All rights reserved.

The effect of mineral trioxide aggregate on phagocytic activity and production of reactive oxygen, nitrogen species and arginase activity by M1 and M2 macrophages.

PubMed

Rezende, T M B; Vieira, L Q; Cardoso, F P; Oliveira, R R; de Oliveira Mendes, S T; Jorge, M L R; Ribeiro Sobrinho, A P

2007-08-01

To assess the influence of co-culture with mineral trioxide aggregate (MTA) on phagocytosis and the production of reactive oxygen intermediates (ROI) and nitrogen (NO) species and the arginase activity by M1 and M2 peritoneal macrophages. Cellular viability, adherence and phagocytosis of Saccharomyces boulardii were assayed in the presence of MTA. Macrophages were stimulated with zymosan for ROI assays and with Fusobacterium nucleatum and Peptostreptococcus anaerobius and IFN-gamma for NO production and arginase activity, when in contact with capillaries containing MTA. Data were analysed by T, anova, Kruskall-Wallis and Mann-Whitney tests. M2 macrophages displayed greater cellular viability in polypropylene tubes, greater ability to ingest yeast and smaller production of ROI and higher arginase activity when compared with M1 macrophages. Both macrophages, M1 and M2, presented similar cell adherence and NO production. The addition of bacterial preparations to macrophages interfered with NO and arginase productions. MTA did not interfere with any of the parameters measured. Phagocytosis and the ability of the two macrophage subtypes to eliminate microbes were not affected by MTA.

Effect of furosemide on ion transport in the turtle bladder: evidence for direct inhibition of active acid-base transport.

PubMed

Ehrenspeck, G; Voner, C

1985-07-25

The diuretic furosemide inhibits acid-base transport in the short-circuited turtle bladder. It inhibits luminal acidification when present in either mucosal or serosal bathing fluids, but decreases alkalinization only from the serosal side of the tissue. The inhibition of both acid-base transport processes is independent of ambient Cl-; and the disulfonic stilbene, SITS, an inhibitor of Cl--HCO3- exchange, fails to prevent the furosemide-elicited inhibition of alkalinization. These results preclude an absolute requirement of a furosemide-sensitive Cl--HCO3- exchange by these transport processes. The drug also interferes with the CO2-induced stimulation of acidification and alkalinization. The inhibition of the residual acidification in acetazolamide-treated, acidotic bladders, however, suggests an action at sites other than cytosolic carbonic anhydrase. Although active Na+ and Cl- reabsorption and tissue oxygen uptake are also decreased by furosemide, the rate of oxygen consumption uncoupled by 2,4-dinitrophenol is not diminished, indicating a primary inhibition of the various ion transport processes, not of metabolism. It is proposed that inhibition of transepithelial acid-base transport by furosemide in the turtle bladder includes inhibition of the acid-base pumps.

Attosecond Coherent Control of the Photo-Dissociation of Oxygen Molecules

NASA Astrophysics Data System (ADS)

Sturm, Felix; Ray, Dipanwita; Wright, Travis; Shivaram, Niranjan; Bocharova, Irina; Slaughter, Daniel; Ranitovic, Predrag; Belkacem, Ali; Weber, Thorsten

2016-05-01

Attosecond Coherent Control has emerged in recent years as a technique to manipulate the absorption and ionization in atoms as well as the dissociation of molecules on an attosecond time scale. Single attosecond pulses and attosecond pulse trains (APTs) can coherently excite multiple electronic states. The electronic and nuclear wave packets can then be coupled with a second pulse forming multiple interfering quantum pathways. We have built a high flux extreme ultraviolet (XUV) light source delivering APTs based on HHG that allows to selectively excite neutral and ion states in molecules. Our beamline provides spectral selectivity and attosecond interferometric control of the pulses. In the study presented here, we use APTs, generated by High Harmonic Generation in a high flux extreme ultraviolet light source, to ionize highly excited states of oxygen molecules. We identify the ionization/dissociation pathways revealing vibrational structure with ultra-high resolution ion 3D-momentum imaging spectroscopy. Furthermore, we introduce a delay between IR pulses and XUV/IR pulses to constructively or destructively interfere the ionization and dissociation pathways, thus, enabling the manipulation of both the O2+and the O+ ion yields with attosecond precision. Supported by DOE under Contract No. DE-AC02-05CH11231.

Bluetooth Communication Interface for EEG Signal Recording in Hyperbaric Chambers.

PubMed

Pastena, Lucio; Formaggio, Emanuela; Faralli, Fabio; Melucci, Massimo; Rossi, Marco; Gagliardi, Riccardo; Ricciardi, Lucio; Storti, Silvia F

2015-07-01

Recording biological signals inside a hyperbaric chamber poses technical challenges (the steel walls enclosing it greatly attenuate or completely block the signals as in a Faraday cage), practical (lengthy cables creating eddy currents), and safety (sparks hazard from power supply to the electronic apparatus inside the chamber) which can be overcome with new wireless technologies. In this technical report we present the design and implementation of a Bluetooth system for electroencephalographic (EEG) recording inside a hyperbaric chamber and describe the feasibility of EEG signal transmission outside the chamber. Differently from older systems, this technology allows the online recording of amplified signals, without interference from eddy currents. In an application of this technology, we measured EEG activity in professional divers under three experimental conditions in a hyperbaric chamber to determine how oxygen, assumed at a constant hyperbaric pressure of 2.8 ATA , affects the bioelectrical activity. The EEG spectral power estimated by fast Fourier transform and the cortical sources of the EEG rhythms estimated by low-resolution brain electromagnetic analysis were analyzed in three different EEG acquisitions: breathing air at sea level; breathing oxygen at a simulated depth of 18 msw, and breathing air at sea level after decompression.

Vascular aging: Chronic oxidative stress and impairment of redox signaling—consequences for vascular homeostasis and disease

PubMed Central

Bachschmid, Markus M.; Schildknecht, Stefan; Matsui, Reiko; Zee, Rebecca; Haeussler, Dagmar; Cohen, Richard A.; Pimental, David; van der Loo, Bernd

2013-01-01

Characteristic morphological and molecular alterations such as vessel wall thickening and reduction of nitric oxide occur in the aging vasculature leading to the gradual loss of vascular homeostasis. Consequently, the risk of developing acute and chronic cardiovascular diseases increases with age. Current research of the underlying molecular mechanisms of endothelial function demonstrates a duality of reactive oxygen and nitrogen species in contributing to vascular homeostasis or leading to detrimental effects when formed in excess. Furthermore, changes in function and redox status of vascular smooth muscle cells contribute to age-related vascular remodeling. The age-dependent increase in free radical formation causes deterioration of the nitric oxide signaling cascade, alters and activates prostaglandin metabolism, and promotes novel oxidative posttranslational protein modifications that interfere with vascular and cell signaling pathways. As a result, vascular dysfunction manifests. Compensatory mechanisms are initially activated to cope with age-induced oxidative stress, but become futile, which results in irreversible oxidative modifications of biological macromolecules. These findings support the ‘free radical theory of aging’ but also show that reactive oxygen and nitrogen species are essential signaling molecules, regulating vascular homeostasis. PMID:22380696

Parkin modulates expression of HIF-1α and HIF-3α during hypoxia in gliobastoma-derived cell lines in vitro.

PubMed

Maugeri, Grazia; D'Amico, Agata Grazia; Reitano, Rita; Saccone, Salvatore; Federico, Concetta; Cavallaro, Sebastiano; D'Agata, Velia

2016-06-01

Mutation of the Parkin gene causes an autosomal recessive juvenile-onset form of Parkinson's disease. However, recently, it has been also linked to a wide variety of malignancies, including glioblastoma multiforme (GBM). In this pathology, Parkin exhibits a tumor suppressor role by mitigating the proliferation rate in both in vitro and in vivo models. However, Parkin involvement in the hypoxic process has not as yet been investigated. GBM is the most common and aggressive primary brain tumor in adults and is characterized by hypoxic areas. The low oxygen supply causes the expression of hypoxia-inducible factors (HIFs) leading to an accumulation of pro-angiogenic factors and tumoral invasiveness. We assess the relationship between Parkin and two HIFs expressed during hypoxic conditions, namely HIF-1α and HIF-3α. Our data show that Parkin is downregulated under hypoxia and that it interferes with HIF expression based on cellular oxygen tension. These results suggest a role for the involvement of Parkin in GBM, although further studies will be needed to understand the mechanism by which it modulates HIF-1α and HIF-3α expression.

Rapid changes in local extracellular rat brain glucose observed with an in vivo glucose sensor.

PubMed

Hu, Y; Wilson, G S

1997-04-01

A needle-type electrochemically based microsensor for glucose (110 microns o.d.) is described. This sensor, designed for monitoring transient glucose content changes in response to neural stimuli, has a response time of approximately 5 s and has been shown to be free of interference from endogenous electroactive species such as ascorbate, urate, and various neurotransmitters. It exhibits linear response to glucose up to 10 mM. The usefulness of the sensor has been demonstrated by examining the time-dependent interstitial glucose concentration in the rat hippocampus in response to KCl depolarization and by stimulation of glutamate neurons through a perforant pathway. Simultaneous monitoring of oxygen is also carried out and demonstrates that for both oxygen and glucose there is substantial local depletion of both species and that their pools are replenished by increased regional cerebral blood flow. The transient initial rapid (10-13 s) decrease up to 20-34%, observed on a time scale comparable to that for neurotransmitter release, may be involved in a recently suggested astrocytic uptake for glutamate-stimulated aerobic glycolysis possibly needed to meet energy homeostasis in brain. These studies demonstrate the importance of microsensors in monitoring transient events linked to neuronal stimulation.

False elevation of carboxyhemoglobin: case report.

PubMed

Mehrotra, Shruti; Edmonds, Marcia; Lim, Rodrick K

2011-02-01

Carbon monoxide toxicity in infants and children, like adults, produce nonspecific symptoms with normal vital signs necessitating the serum measurement of carboxyhemoglobin (COHb). In infants, the COHb may be falsely elevated. Our goal was to report a case of suspected carbon monoxide toxicity in an infant and the likely cause of the falsely elevated serum COHb. A previously healthy 3-month-old girl presented to the pediatric emergency department (ED) with smoke inhalation from a defective furnace. She was asymptomatic. On examination, she was alert, with Glasgow Coma Scale of 15 and normal vital signs. Cardiorespiratory and neurological examinations were completely normal. Because of concern regarding carbon monoxide poisoning, she was treated with normobaric oxygen therapy. Initial and subsequent serum COHb levels were persistently elevated, despite treatment and the infant appearing clinically well. As such, she had a prolonged stay in the ED. Further investigations found that fetal hemoglobin interferes with the spectrophotometric method used to analyze serum COHb levels. Carboxyhemoglobin serum level, in infants, may be falsely elevated due to the fetal hemoglobin interfering with standard methods of analysis. Knowledge of the false elevation using standard spectrophotometric methods of COHb in clinically well-appearing infants can decrease unnecessary oxygen therapy and monitoring time in the ED.

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

Hoffmeister, Kathryn N. Gabet; Guildenbecher, Daniel Robert; Kearney, Sean P.

We report the application of ultrafast rotational coherent anti-Stokes Raman scattering (CARS) for temperature and relative oxygen concentration measurements in the plume emanating from a burning aluminized ammonium perchlorate propellant strand. Combustion of these metal-based propellants is a particularly hostile environment for laserbased diagnostics, with intense background luminosity, scattering and beam obstruction from hot metal particles that can be as large as several hundred microns in diameter. CARS spectra that were previously obtained using nanosecond pulsed lasers in an aluminumparticle- seeded flame are examined and are determined to be severely impacted by nonresonant background, presumably as a result of themore » plasma formed by particulateenhanced laser-induced breakdown. Introduction of fs/ps laser pulses enables CARS detection at reduced pulse energies, decreasing the likelihood of breakdown, while simultaneously providing time-gated elimination of any nonresonant background interference. Temperature probability densities and temperature/oxygen correlations were constructed from ensembles of several thousand single-laser-shot measurements from the fs/ps rotational CARS measurement volume positioned within 3 mm or less of the burning propellant surface. Preliminary results in canonical flames are presented using a hybrid fs/ps vibrational CARS system to demonstrate our progress towards acquiring vibrational CARS measurements for more accurate temperatures in the very high temperature propellant burns.« less

Host/parasite relationship in the in vitro infection of rat gliocytes by Neospora caninum: evaluation of cell respiration.

PubMed

Pinheiro, Alexandre M; Santos, Cláudia Valle; Costa, Maria de Fátima D; Rodrigues, Luiz Erlon A

2007-08-01

Neospora caninum is a protozoon that causes abortion in cattle and neuromuscular lesions in dogs, with the formation of cysts mainly in the central nervous system. Since N. caninum is an intracellular parasite with tropism for the cells of nervous system, this study evaluated the respiratory metabolism of glial cells infected by this* parasite. Glial cultures obtained from the cerebral cortex of newborn rats were kept in DMEM enriched with 10% fetal bovine serum, 1 mM pyruvic acid and 2 mM of L-glutamine. They were infected at a ratio of approximately 1:1 (cell/parasite). Oxygen consumption was evaluated by polarography in the non infected and N. caninum infected groups, 24 and 72 h following infection. Glial cell respiration after 24 and 72 h was 307.2 +/- 34.7 and 308.9 +/- 64.1 microL of oxygen per mug of total protein per minute, and 566.2 +/- 54.6 and 579 +/- 117.5 microL O2/microg of total protein/minute in the control and infected groups, respectively. These results show that N. caninum does not interfere with glial respiration in vitro.

Raman Gas Species Measurements in Hydrocarbon-Fueled Rocket Engine Injector Flows

NASA Technical Reports Server (NTRS)

Wehrmeyer, Joseph; Hartfield, Roy J., Jr.; Trinh, Huu P.; Dobson, Chris C.; Eskridge, Richard H.

2000-01-01

Rocket engine propellent injector development at NASA-Marshall includes experimental analysis using optical techniques, such as Raman, fluorescence, or Mie scattering. For the application of spontaneous Raman scattering to hydrocarbon-fueled flows a technique needs to be developed to remove the interfering polycyclic aromatic hydrocarbon fluorescence from the relatively weak Raman signals. A current application of such a technique is to the analysis of the mixing and combustion performance of multijet, impinging-jet candidate fuel injectors for the baseline Mars ascent engine, which will burn methane and liquid oxygen produced in-situ on Mars to reduce the propellent mass transported to Mars for future manned Mars missions. The Raman technique takes advantage of the strongly polarized nature of Raman scattering. It is shown to be discernable from unpolarized fluorescence interference by subtracting one polarized image from another. Both of these polarized images are obtained from a single laser pulse by using a polarization-separating calcite rhomb mounted in the imaging spectrograph. A demonstration in a propane-air flame is presented, as well as a high pressure demonstration in the NASA-Marshall Modular Combustion Test Artice, using the liquid methane-liquid oxygen propellant system

31 CFR 245.8 - Receipt or recovery of original check.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Receipt or recovery of original check... CHECKS § 245.8 Receipt or recovery of original check. (a) If the original check is received or recovered... of instructions with respect to the negotiability of such check. (b) If the original check is...

30 CFR 75.902-2 - Approved ground check systems not employing pilot check wires.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Approved ground check systems not employing pilot check wires. 75.902-2 Section 75.902-2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... employing pilot check wires. Ground check systems not employing pilot check wires will be approved only if...

30 CFR 75.902-2 - Approved ground check systems not employing pilot check wires.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Approved ground check systems not employing pilot check wires. 75.902-2 Section 75.902-2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... employing pilot check wires. Ground check systems not employing pilot check wires will be approved only if...

Pilot Study of Exercise Therapy on Painful Diabetic Peripheral Neuropathy

PubMed Central

Yoo, Min; D’Silva, Linda; Martin, Katherine; Sharma, Neena; Pasnoor, Mamatha; LeMaster, Joseph

2015-01-01

Objective Painful diabetic peripheral neuropathy (DPN) is a common complication of diabetes. While the beneficial effect of exercise on diabetes is well established, its effect specifically on painful DPN has not been thoroughly explored. The objective of this pilot study was to examine the effect of aerobic exercise on pain in people with DPN. Methods Fourteen sedentary individuals (mean age 57±5.11 years) with painful DPN were enrolled in a 16-week, supervised aerobic exercise program. The Brief Pain Inventory-Diabetic Peripheral Neuropathy (BPI-DPN) was used to assess pain intensity (worst, least, average, now) and pain interference with daily life (activity, mood, walk, normal work, relationship, sleep, enjoyment of life) pre- and post -intervention. Body mass index (BMI), maximum oxygen uptake (VO2max), hemoglobin A1c (HbA1c), and blood pressure were also measured pre-and post-intervention as secondary outcomes of interest. Results Significant reductions in pain interference were observed with walking (4.93±3.03 pre to 3.29±2.89 post, p=0.016), normal work (5.39±3.32 pre to 3.79±3.04 post, p=0.032), relationship with others (3.96±3.53 pre to 1.29±1.27 post, p=0.006), sleep (5.11±3.04 pre to 3.5±3.03 post, p=0.02), and the overall pain interference (4.65±2.70 pre to 2.97±2.22 post, p=0.013) following the intervention; however, there was no change in pain intensity. VO2max increased significantly post-intervention (16.02±3.84ml/kg/min pre to 17.18±4.19ml/kg/min, p=0.028), while BMI, HbA1c, and blood pressure remained unchanged. Conclusion These preliminary results suggest that perceived pain interference may be reduced following an aerobic exercise intervention among people with painful DPN, without a change in pain intensity. Further validation by a RCT is needed. PMID:25800666

Pilot Study of Exercise Therapy on Painful Diabetic Peripheral Neuropathy.

PubMed

Yoo, Min; D'Silva, Linda J; Martin, Katherine; Sharma, Neena K; Pasnoor, Mamatha; LeMaster, Joseph W; Kluding, Patricia M

2015-08-01

Painful diabetic peripheral neuropathy (DPN) is a common complication of diabetes. While the beneficial effect of exercise on diabetes is well established, its effect specifically on painful DPN has not been thoroughly explored. The objective of this pilot study was to examine the effect of aerobic exercise on pain in people with DPN. Fourteen sedentary individuals (mean age 57 ± 5.11 years) with painful DPN were enrolled in a 16-week, supervised aerobic exercise program. The Brief Pain Inventory-Diabetic Peripheral Neuropathy was used to assess pain intensity (worst, least, average, now) and pain interference with daily life (activity, mood, walk, normal work, relationship, sleep, enjoyment of life) pre intervention and postintervention. Body mass index (BMI), maximum oxygen uptake (VO2max ), hemoglobin A1c (HbA1c), and blood pressure were also measured preintervention and postintervention as secondary outcomes of interest. Significant reductions in pain interference were observed with walking (4.93 ± 3.03 pre to 3.29 ± 2.89 post, P = 0.016), normal work (5.39 ± 3.32 pre to 3.79 ± 3.04 post, P = 0.032), relationship with others (3.96 ± 3.53 pre to 1.29 ± 1.27 post, P = 0.006), sleep (5.11 ± 3.04 pre to 3.5 ± 3.03 post, P = 0.02), and the overall pain interference (4.65 ± 2.70 pre to 2.97 ± 2.22 post, P = 0.013) following the intervention; however, there was no change in pain intensity. VO2max increased significantly postintervention (16.02 ± 3.84 ml/kg/min pre to 17.18 ± 4.19 ml/kg/min, P = 0.028), while BMI, HbA1c, and blood pressure remained unchanged. These preliminary results suggest that perceived pain interference may be reduced following an aerobic exercise intervention among people with painful DPN, without a change in pain intensity. Further validation by a RCT is needed. Wiley Periodicals, Inc.

Double checking: a second look

PubMed Central

Chreim, Samia; Forster, Alan

2015-01-01

Abstract Rationale, aims and objectives Double checking is a standard practice in many areas of health care, notwithstanding the lack of evidence supporting its efficacy. We ask in this study: ‘How do front line practitioners conceptualize double checking? What are the weaknesses of double checking? What alternate views of double checking could render it a more robust process?’ Method This is part of a larger qualitative study based on 85 semi‐structured interviews of health care practitioners in general internal medicine and obstetrics and neonatology; thematic analysis of the transcribed interviews was undertaken. Inductive and deductive themes are reported. Results Weaknesses in the double checking process include inconsistent conceptualization of double checking, double (or more) checking as a costly and time‐consuming procedure, double checking trusted as an accepted and stand‐alone process, and double checking as preventing reporting of near misses. Alternate views of double checking that would render it a more robust process include recognizing that double checking requires training and a dedicated environment, Introducing automated double checking, and expanding double checking beyond error detection. These results are linked with the concepts of collective efficiency thoroughness trade off (ETTO), an in‐family approach, and resilience. Conclusion(s) Double checking deserves more questioning, as there are limitations to the process. Practitioners could view double checking through alternate lenses, and thus help strengthen this ubiquitous practice that is rarely challenged. PMID:26568537

Adaptive nitrogen and integrated weed management in conservation agriculture: impacts on agronomic productivity, greenhouse gas emissions, and herbicide residues.

PubMed

Oyeogbe, Anthony Imoudu; Das, T K; Bhatia, Arti; Singh, Shashi Bala

2017-04-01

Increasing nitrogen (N) immobilization and weed interference in the early phase of implementation of conservation agriculture (CA) affects crop yields. Yet, higher fertilizer and herbicide use to improve productivity influences greenhouse gase emissions and herbicide residues. These tradeoffs precipitated a need for adaptive N and integrated weed management in CA-based maize (Zea mays L.)-wheat [Triticum aestivum (L.) emend Fiori & Paol] cropping system in the Indo-Gangetic Plains (IGP) to optimize N availability and reduce weed proliferation. Adaptive N fertilization was based on soil test value and normalized difference vegetation index measurement (NDVM) by GreenSeeker™ technology, while integrated weed management included brown manuring (Sesbania aculeata L. co-culture, killed at 25 days after sowing), herbicide mixture, and weedy check (control, i.e., without weed management). Results indicated that the 'best-adaptive N rate' (i.e., 50% basal + 25% broadcast at 25 days after sowing + supplementary N guided by NDVM) increased maize and wheat grain yields by 20 and 14% (averaged for 2 years), respectively, compared with whole recommended N applied at sowing. Weed management by brown manuring (during maize) and herbicide mixture (during wheat) resulted in 10 and 21% higher grain yields (averaged for 2 years), respectively, over the weedy check. The NDVM in-season N fertilization and brown manuring affected N 2 O and CO 2 emissions, but resulted in improved carbon storage efficiency, while herbicide residuals in soil were significantly lower in the maize season than in wheat cropping. This study concludes that adaptive N and integrated weed management enhance synergy between agronomic productivity, fertilizer and herbicide efficiency, and greenhouse gas mitigation.

Quasi-continuous parallel online scattered light, fluorescence and dissolved oxygen tension measurement combined with monitoring of the oxygen transfer rate in each well of a shaken microtiter plate.

PubMed

Ladner, Tobias; Held, Markus; Flitsch, David; Beckers, Mario; Büchs, Jochen

2016-12-03

Microtiter plates (MTP) are often applied as culture vessels in high-throughput screening programs. If online measuring techniques are available, MTPs can also be applied in the first steps of process development. For such small-scale bioreactors dipping probes are usually too large; therefore, optical measurements are often used. For example, the BioLector technology allows for the online monitoring of scattered light and fluorescence in each well of a continuously orbitally shaken MTP. Although this system provides valuable data, these measurements are mainly of a semi-quantitative nature. Therefore, signal calibration is required to obtain absolute values. With the µRAMOS technology it became possible for the first time to quantify the oxygen transfer rate (OTR) separately in each well of an MTP. In this work, a device is presented that combines both techniques, to provide a hitherto unparalleled high amount of information from each single well. Because both systems (BioLector and µRAMOS) are based on optical measurements, the measurements need to be synchronized to avoid interferences with the optical signals. The new experimental setup was applied for online monitoring in cultures of Escherichia coli and Hansenula polymorpha. It has been demonstrated that the well-to-well reproducibility is very high, and that the monitored signals provide reliable and valuable information about the process. With varying filling volumes, different maximum oxygen transfer capacities (OTR max ) were adjusted in oxygen-limited cultures. The different degrees of stress during the culture due to oxygen limitation affected microbial growth and also impacted reproducibility from culture to culture. Furthermore, it was demonstrated that this new device significantly simplifies the experimental efforts: instead of parallel cultures in a shake flask and MTP, just one single experiment in MTP needs to be conducted to measure the OTR, dissolved oxygen tension (DOT), scattered light and fluorescence. The new device is a very suitable system for the online monitoring of cultures in continuously orbitally shaken MTPs. Due to the high number of parameters that can simultaneously be measured with this small-scale device, deeper insight into the investigated microbial system can be achieved. Furthermore, the experimental efforts to obtain OTR, DOT, scattered light and fluorescence signals during a culture are decreased. Ultimately, this new technology and the resulting high amount of collected data will eliminate the currently existing separation between screening and process development. Graphical abstract Picture of the combined μRAMOS and BioLector setup which allows for measurements of the oxygen transfer rate (OTR), dissolved oxygen tension (DOT), scattered light and fluorescence in each single well of an orbitally shaken microtiter plate.

Solubility of tungsten in a haplobasaltic melt as a function of temperature and oxygen fugacity

NASA Astrophysics Data System (ADS)

Ertel, W.; O'Neill, H. St. C.; Dingwell, D. B.; Spettel, B.

1996-04-01

The solubility of tungsten (W) in a haplobasaltic melt has been determined as a function of oxygen fugacity in the temperature range 1300-1500°C using the mechanically assisted equilibrium technique of Dingwell et al. (1994), and at 1600-1700°C by the wire loop method. Quenched samples were analysed for W by using ICP-AES as well as INAA, and sample major element compositions were checked by electron microprobe. W concentrations ranged from 20 ppm to 17 wt%, and the solution of WO 2 in the melt may be described by Henry's Law up to remarkably high concentrations (e.g., 14 wt% at 1500°C). W dissolves in the melt with a quadrivalent (4+) formal oxidation state over the entire range of oxygen fugacity and temperature investigated. The solubility of W decreases strongly with increasing temperature at constant oxygen fugacity. The solubility data have been used to calculate trace distribution coefficients for W between Fe-rich metal and silicate melt, using literature values for the activity coefficient of W in liquid Fe. Comparison of our data with the distribution coefficients for Mo calculated from the analogous Mo solubility data of Holzheid et al. (1994) shows that the ratio of the metal-silicate distribution coefficient DMomet/sil/ DWmet/sil remains very high (~10 3) at all T-fO 2 conditions. However, in the Earth's mantle, Mo is relatively more depleted than W only by a factor of three. The relative abundances of W and Mo in the Earth's mantle cannot, therefore, be explained by core formation from a homogeneously accreted Earth whatever the temperature at which metal/silicate equilibrium may have ocurred might have been. Their abundances may be quantitatively accounted for by a heterogeneous accretion model such as that of O'Neill (1991).

Four space application material coatings on the Long-Duration Exposure Facility (LDEF)

NASA Technical Reports Server (NTRS)

Scialdone, John J.; Clatterbuck, Carroll

1995-01-01

Four material coatings of different thicknesses were flown on the LDEF to determine their ability to perform in the harsh space environment. The coatings, located in the ram direction of the spacecraft, were exposed for 10 months to the low-Earth orbit (LEO) environments experienced by the LDEF at an orbit of 260 nautical miles. They consisted of indium oxide (In2O3), silicon oxide (SiO(x)), clear RTV silicone, and silicone with silicate-treated zinc oxide (ZnO). These coatings were flown to assess their behavior when exposed to atomic oxygen and to confirm their good radiative properties, stability, electrical conductivity, and resistance to UV exposure. The flown samples were checked and compared with the reference unflown samples using high-magnification optical inspection, ESCA analysis, weight changes, and dimensional changes. These comparisons indicated the following. The 1000 A SiO(x) coating eroded uniformly, with minor changes in its radiative properties. The 100 A In2O3 coating eroded completely down to the Kapton backing, with resultant losses of reflectance. The RTV-615 showed erosion, with carbon (C) content losses, while the Si remained constant, with a doubling of the oxygen (O) concentration. The RTV-615 silicone with K2SiO3-treated ZnO changed from flat to glossy white in appearance. It lost C, was etched, and increased its O content. The upper layers showed no remaining Zn or K. Losses of reflectance occurred within certain wavelength bands. It was not possible to evaluate the experimental oxygen reaction rate using the calculated atomic oxygen fluence of 2.6 x 10(exp 20) atoms/cm(exp 2) for the exposure of these coatings during the flight. The bakeout of the coatings was not carried out prior to the flight. Hence, the coating weight and dimensional losses included losses by outgassing products.

30 CFR 75.902-2 - Approved ground check systems not employing pilot check wires.

Code of Federal Regulations, 2014 CFR

2014-07-01

... pilot check wires. 75.902-2 Section 75.902-2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... employing pilot check wires. Ground check systems not employing pilot check wires will be approved only if... ground continuity is broken. ...

30 CFR 75.902-2 - Approved ground check systems not employing pilot check wires.

Code of Federal Regulations, 2012 CFR

2012-07-01

... pilot check wires. 75.902-2 Section 75.902-2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... employing pilot check wires. Ground check systems not employing pilot check wires will be approved only if... ground continuity is broken. ...

30 CFR 75.902-2 - Approved ground check systems not employing pilot check wires.

Code of Federal Regulations, 2013 CFR

2013-07-01

... pilot check wires. 75.902-2 Section 75.902-2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... employing pilot check wires. Ground check systems not employing pilot check wires will be approved only if... ground continuity is broken. ...

Rainfall, Streamflow, and Water-Quality Data During Stormwater Monitoring, Halawa Stream Drainage Basin, Oahu, Hawaii, July 1, 2006 to June 30, 2007

USGS Publications Warehouse

Young, Stacie T.M.; Jamison, Marcael T.J.

2007-01-01

Storm runoff water-quality samples were collected as part of the State of Hawaii Department of Transportation Stormwater Monitoring Program. This program is designed to assess the effects of highway runoff and urban runoff on Halawa Stream. For this program, rainfall data were collected at two stations, continuous streamflow data at three stations, and water-quality data at five stations, which include the two continuous streamflow stations. This report summarizes rainfall, streamflow, and water-quality data collected between July 1, 2006 and June 30, 2007. A total of 13 samples was collected over two storms during July 1, 2006 to June 30, 2007. The goal was to collect grab samples nearly simultaneously at all five stations and flow-weighted time-composite samples at the three stations equipped with automatic samplers. Samples were analyzed for total suspended solids, total dissolved solids, nutrients, chemical oxygen demand, and selected trace metals (cadmium, chromium, copper, lead, nickel, and zinc). Additionally, grab samples were analyzed for oil and grease, total petroleum hydrocarbons, fecal coliform, and biological oxygen demand. Quality-assurance/quality-control samples were also collected during storms and during routine maintenance to verify analytical procedures and check the effectiveness of equipment-cleaning procedures.

Online total organic carbon (TOC) monitoring for water and wastewater treatment plants processes and operations optimization

NASA Astrophysics Data System (ADS)

Assmann, Céline; Scott, Amanda; Biller, Dondra

2017-08-01

Organic measurements, such as biological oxygen demand (BOD) and chemical oxygen demand (COD) were developed decades ago in order to measure organics in water. Today, these time-consuming measurements are still used as parameters to check the water treatment quality; however, the time required to generate a result, ranging from hours to days, does not allow COD or BOD to be useful process control parameters - see (1) Standard Method 5210 B; 5-day BOD Test, 1997, and (2) ASTM D1252; COD Test, 2012. Online organic carbon monitoring allows for effective process control because results are generated every few minutes. Though it does not replace BOD or COD measurements still required for compliance reporting, it allows for smart, data-driven and rapid decision-making to improve process control and optimization or meet compliances. Thanks to the smart interpretation of generated data and the capability to now take real-time actions, municipal drinking water and wastewater treatment facility operators can positively impact their OPEX (operational expenditure) efficiencies and their capabilities to meet regulatory requirements. This paper describes how three municipal wastewater and drinking water plants gained process insights, and determined optimization opportunities thanks to the implementation of online total organic carbon (TOC) monitoring.

10 CFR 73.59 - Relief from fingerprinting, identification and criminal history records checks and other elements...

Code of Federal Regulations, 2013 CFR

2013-01-01

... history records checks and other elements of background checks for designated categories of individuals..., identification and criminal history records checks and other elements of background checks for designated categories of individuals. Fingerprinting, and the identification and criminal history records checks...

10 CFR 73.59 - Relief from fingerprinting, identification and criminal history records checks and other elements...

Code of Federal Regulations, 2010 CFR

2010-01-01

... history records checks and other elements of background checks for designated categories of individuals..., identification and criminal history records checks and other elements of background checks for designated categories of individuals. Fingerprinting, and the identification and criminal history records checks...

Optical measurements of atomic oxygen concentration, temperature and nitric oxide production rate in flames

NASA Astrophysics Data System (ADS)

Myhr, Franklin Henry

An optical method for measuring nitric oxide (NO) production rates in flames was developed and characterized in a series of steady, one-dimensional, atmospheric-pressure laminar flames of 0.700 Hsb2/0.199 Nsb2/0.101 COsb2 or 0.700 CHsb4/0.300 Nsb2 (by moles) with dry air, with equivalence ratios from 0.79 to 1.27. Oxygen atom concentration, (O), was measured by two-photon laser-induced fluorescence (LIF), temperature was measured by ultraviolet Rayleigh scattering, and nitrogen concentration was calculated from supplied reactant flows; together this information was used to calculate the NO production rate through the thermal (Zel'dovich) mechanism. Measurements by two other techniques were compared with results from the above method. In the first comparison, gas sampling was used to measure axial NO concentration profiles, the slopes of which were multiplied by velocity to obtain total NO production rates. In the second comparison, LIF measurements of hydroxyl radical (OH) were used with equilibrium water concentrations and a partial equilibrium assumption to find (O). Nitric oxide production rates from all three methods agreed reasonably well. Photolytic interference was observed during (O) LIF measurements in all of the flames; this is the major difficulty in applying the optical technique. Photolysis of molecular oxygen in lean flames has been well documented before, but the degree of interference observed in the rich flames suggests that some other molecule is also dissociating; the candidates are OH, CO, COsb2 and Hsb2O. An extrapolative technique for removing the effects of photolysis from (O) LIF measurements worked well in all flames where NO production was significant. Using the optical method to measure NO production rates in turbulent flames will involve a tradeoff among spatial resolution, systematic photolysis error, and random shot noise. With the conventional laser system used in this work, a single pulse with a resolution of 700 mum measured NO production rates as low as 2×10sp{-3}\\ gmol/msp3-s with photolysis error less than a factor of two and random shot noise of 35%. By using a double-pulse technique and relaxing the spatial resolution to 2 mm, production rates down to 2×10sp{-5}\\ gmol/msp3-s can be measured with shot noise of 22%. Extension to two-dimensional imaging will require a multipass cell or very large pulse energy (˜200 mJ at 226 nm).

38 CFR 3.1003 - Returned and canceled checks.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Returned and canceled... canceled checks. Where the payee of a check for benefits has died prior to negotiating the check, the check shall be returned to the issuing office and canceled. (a) The amount represented by the returned check...

14 CFR 121.411 - Qualifications: Check airmen (airplane) and check airmen (simulator).

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Qualifications: Check airmen (airplane) and... § 121.411 Qualifications: Check airmen (airplane) and check airmen (simulator). Link to an amendment... airman (airplane) is a person who is qualified, and permitted, to conduct flight checks or instruction in...

Power considerations for an early manned Mars mission utilizing the space station

NASA Technical Reports Server (NTRS)

Valgora, Martin E.

1987-01-01

Power requirements and candidate electrical power sources were examined for the supporting space infrastructure for an early (2004) manned Mars mission. This two-year mission (60-day stay time) assumed a single six crew piloted vehicle with a Mars lander for four of the crew. The transportation vehicle was assumed to be a hydrogen/oxygen propulsion design with or without large aerobrakes and assembled and checked out on the LEO Space Station. The long transit time necessitated artificial gravity of the crew by rotating the crew compartments. This rotation complicates power source selection. Candidate power sources were examined for the Lander, Mars Orbiter, supporting Space Station, co-orbiting Propellant Storage Depot, and alternatively, a co-orbiting Propellant Generation (water electrolysis) Depot. Candidates considered were photovoltaics with regenerative fuel cells or batteries, solar dynamics, isotope dynamics, and nuclear power.

Determination of Ethanol in Kombucha, Juices, and Alcohol-Free Beer by EnzytecTMLiquid Ethanol: Single-Laboratory Validation, First Action 2017.07.

PubMed

Lacorn, Markus; Hektor, Thomas

2018-04-04

Enzytec TM Liquid Ethanol is an enzymatic test for the determinationof ethanol in kombucha, juices, and alcohol-free beer. The kit contains two components in a ready-to-use format. Quantification is based on the catalytic activity of alcohol dehydrogenase, which oxidizes ethanol to acetaldehyde and converts NAD + to NADH. Measurement is performed in 3 mL cuvettes at 340 nm within 20 min. Samples with alcohol contents around 0.5% alcohol by volume need to be diluted 1:20 or 1:50 with water before measurement. Acetaldehyde interferes at concentrations higher than 3000 mg/L, whereas sulfite interferes at concentrations higher than 300 mg/L. The linear measurement range is from 0.03 up to 0.5 g/L ethanol, whereas LOD and LOQ are 1.9 and 3.3 mg/L ethanol, respectively. Kombucha with concentrations between 2.85 and 5.82 g/L showed relative repeatability standard deviation around 1%, whereas juices were below 2%. Results from a reproducibility experiment revealed that at a concentration of 0.1 g/L, the RSD R was at 2.5%, whereas at higher concentrations between 0.2 and 0.3 g/L, coefficients around 1% were obtained. Trueness was checked by using Cerilliant aqueous ethanol solutions and beer with concentration of 0.4 and 4 g/L (BCR-651 and BCR-652). Spiking of kombucha and juice samples resulted in recoveries between 95% and 104%. Acceptable stability was found for the whole test kit under accelerated conditions at 37°C for 2 weeks. The kit is also not susceptible to short freezing-thawing cycles and harsh transport conditions.

Random uncertainty of photometric determination of hemolysis index on the Abbott Architect c16000 platform.

PubMed

Aloisio, Elena; Carnevale, Assunta; Pasqualetti, Sara; Birindelli, Sarah; Dolci, Alberto; Panteghini, Mauro

2018-01-16

Automatic photometric determination of the hemolysis index (HI) on serum and plasma samples is central to detect potential interferences of in vitro hemolysis on laboratory tests. When HI is above an established cut-off for interference, results may suffer from a significant bias and undermine clinical reliability of the test. Despite its undeniable importance for patient safety, the analytical performance of HI estimation is not usually checked in laboratories. Here we evaluated for the first time the random source of measurement uncertainty of HI determination on the two Abbott Architect c16000 platforms in use in our laboratory. From January 2016 to September 2017, we collected data from daily photometric determination of HI on a fresh-frozen serum pool with a predetermined HI value of ~100 (corresponding to ~1g/L of free hemoglobin). Monthly and cumulative CVs were calculated. During 21months, 442 and 451 measurements were performed on the two platforms, respectively. Monthly CVs ranged from 0.7% to 2.7% on c16000-1 and from 0.8% to 2.5% on c16000-2, with a between-platform cumulative CV of 1.82% (corresponding to an expanded uncertainty of 3.64%). Mean HI values on the two platforms were just slightly biased (101.3 vs. 103.1, 1.76%), but, due to the high precision of measurements, this difference assumed statistical significance (p<0.0001). Even though no quality specifications are available to date, our study shows that the HI measurement on Architect c16000 platform has nice reproducibility that could be considered in establishing the state of the art of the measurement. Copyright © 2018 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

From field notes to data portal - An operational QA/QC framework for tower networks

NASA Astrophysics Data System (ADS)

Sturtevant, C.; Hackley, S.; Meehan, T.; Roberti, J. A.; Holling, G.; Bonarrigo, S.

2016-12-01

Quality assurance and control (QA/QC) is one of the most important yet challenging aspects of producing research-quality data. This is especially so for environmental sensor networks collecting numerous high-frequency measurement streams at distributed sites. Here, the quality issues are multi-faceted, including sensor malfunctions, unmet theoretical assumptions, and measurement interference from the natural environment. To complicate matters, there are often multiple personnel managing different sites or different steps in the data flow. For large, centrally managed sensor networks such as NEON, the separation of field and processing duties is in the extreme. Tower networks such as Ameriflux, ICOS, and NEON continue to grow in size and sophistication, yet tools for robust, efficient, scalable QA/QC have lagged. Quality control remains a largely manual process relying on visual inspection of the data. In addition, notes of observed measurement interference or visible problems are often recorded on paper without an explicit pathway to data flagging during processing. As such, an increase in network size requires a near-proportional increase in personnel devoted to QA/QC, quickly stressing the human resources available. There is a need for a scalable, operational QA/QC framework that combines the efficiency and standardization of automated tests with the power and flexibility of visual checks, and includes an efficient communication pathway from field personnel to data processors to end users. Here we propose such a framework and an accompanying set of tools in development, including a mobile application template for recording tower maintenance and an R/shiny application for efficiently monitoring and synthesizing data quality issues. This framework seeks to incorporate lessons learned from the Ameriflux community and provide tools to aid continued network advancements.

Evidence for human meiotic recombination interference obtained through construction of a short tandem repeat-polymorphism linkage map of chromosome 19

PubMed Central

Weber, James L.; Wang, Zhenyuan; Hansen, Kevin; Stephenson, Matt; Kappel, Clarisse; Salzman, Sherry; Wilkie, Patricia J.; Keats, Bronya; Dracopoli, Nicholas C.; Brandriff, Brigitte F.; Olsen, Anne S.

1993-01-01

An improved linkage map for human chromosome 19 containing 35 short tandem repeat polymorphisms (STRPs) and one VNTR (D19S20) was constructed. The map included 12 new (GATA)n tetranucleotide STRPs. Although total lengths of the male (114 cM) and female (128 cM) maps were similar, at both ends of the chromosome male recombination exceeded female recombination, while in the interior portion of the map female recombination was in excess. Cosmid clones containing the STRP sequences were identified and were positioned along the chromosome by fluorescent in situ hybridization. Four rounds of careful checking and removal of genotyping errors allowed biologically relevant conclusions to be made concerning the numbers and distributions of recombination events on chromosome 19. The average numbers of recombinations per chromosome matched closely the lengths of the genetic maps computed by using the program CRIMAP. Significant numbers of chromosomes with zero, one, two, or three recombinations were detected as products of both female and male meioses. On the basis of the total number of observed pairs of recombination events in which only a single informative marker was situated between the two recombinations, a maximal estimate for the rate of meiotic STRP “gene” conversion without recombination was calculated as 3 × 10−4/meiosis. For distances up to 30 cM between recombinations, many fewer chromosomes which had undergone exactly two recombinations were observed than were expected on the basis of the assumption of independent recombination locations. This strong new evidence for human meiotic interference will help to improve the accuracy of interpretation of clinical DNA test results involving polymorphisms flanking a genetic abnormality. PMID:8213834

Lentiviral vectors encoding shRNAs efficiently transduce and knockdown LINGO-1 but induce an interferon response and cytotoxicity in CNS neurons

PubMed Central

Hutson, Thomas H.; Foster, Edmund; Dawes, John M.; Hindges, Robert; Yáñez-Muñoz, Rafael J.; Moon, Lawrence D.F.

2017-01-01

Background Knocking down neuronal LINGO-1 using short hairpin RNAs (shRNAs) might enhance axon regeneration in the CNS. Integration-deficient lentiviral vectors have great potential as a therapeutic delivery system for CNS injuries. However, recent studies have revealed that shRNAs can induce an interferon response resulting in off-target effects and cytotoxicity. Methods CNS neurons were transduced with integration-deficient lentiviral vectors in vitro. The transcriptional effect of shRNA expression was analysed using qRT-PCR and northern blots were used to assess shRNA production. Results Integration-deficient lentiviral vectors efficiently transduced CNS neurons and knocked down LINGO-1 mRNA in vitro. However, an increase in cell death was observed when lentiviral vectors encoding an shRNA were applied or when high vector concentrations were used. We demonstrate that high doses of vector or the use of vectors encoding shRNAs can induce an up-regulation of interferon stimulated genes (OAS1 and PKR) and a down-regulation of off- target genes (including p75NTR and NgR1). Furthermore, the northern blot demonstrated that these negative consequences occur even when lentiviral vectors express low levels of shRNAs. Together, these results may explain why neurite outgrowth was not enhanced on an inhibitory substrate after transduction with lentiviral vectors encoding an shRNA targeting LINGO-1. Conclusions These findings highlight the importance of including appropriate controls to verify silencing specificity and the requirement to check for an interferon response when conducting RNA interference experiments. However, the potential benefits that RNA interference and viral vectors offer to gene-based therapies to CNS injuries cannot be overlooked and demand further investigation. PMID:22499506

Biomonitoring of boron: Development and characterization of a simple, reliable and quality controlled biomonitoring method.

PubMed

Michalke, Bernhard

2017-03-01

Boron exposure is of interest and concern from an occupational point of view. Usual daily boron intake is related to boron blood plasma concentration <1mg/L and to <3mg/L in urine, but after exposure urine concentrations are quickly elevated. Reliable boron biomonitoring, typically in urine, thus is mandatory for occupational health control institutions. This paper reports on the development of a simple, fast and reliable boron determination procedure based on inductively coupled plasma - optical emission spectrometry (ICP-OES). Major aims for this method were simplicity in sample preparation, low risk for artifacts and interferences, high precision and accuracy, possibly low costs, including lower costs for element selective detection, short total analysis time and suitability for occupational health laboratories. Precision data (serial or day-to-day) from urine and doped urine were very good: <1.5 or <2%. Accuracy was calculated from analysis of a certified reference material (ERM-CD 281), as 99% or according to recoveries of doped concentrations ranging from 102 to 109% recovery. For cross-checking ICP-OES determinations, samples were analyzed also by quadrupole ICP-qMS and by sectorfield ICP-sf-MS at low and medium resolution. Both systems confirmed ICP-OES measurements when using 11 B for quantification. Determinations based on 10 B however showed some bias, except with ICP-sf-MS at medium resolution. The observed elevated signals are discussed with respect to the known Ne ++ interference (as an impurity in Ar), which is not separated in low resolving quadrupole ICP-MS systems or ICP-sf-MS at low resolution. Copyright © 2016 Elsevier GmbH. All rights reserved.

The use of self checks and voting in software error detection - An empirical study

NASA Technical Reports Server (NTRS)

Leveson, Nancy G.; Cha, Stephen S.; Knight, John C.; Shimeall, Timothy J.

1990-01-01

The results of an empirical study of software error detection using self checks and N-version voting are presented. Working independently, each of 24 programmers first prepared a set of self checks using just the requirements specification of an aerospace application, and then each added self checks to an existing implementation of that specification. The modified programs were executed to measure the error-detection performance of the checks and to compare this with error detection using simple voting among multiple versions. The analysis of the checks revealed that there are great differences in the ability of individual programmers to design effective checks. It was found that some checks that might have been effective failed to detect an error because they were badly placed, and there were numerous instances of checks signaling nonexistent errors. In general, specification-based checks alone were not as effective as specification-based checks combined with code-based checks. Self checks made it possible to identify faults that had not been detected previously by voting 28 versions of the program over a million randomly generated inputs. This appeared to result from the fact that the self checks could examine the internal state of the executing program, whereas voting examines only final results of computations. If internal states had to be identical in N-version voting systems, then there would be no reason to write multiple versions.

14 CFR 121.411 - Qualifications: Check airmen (airplane) and check airmen (simulator).

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Qualifications: Check airmen (airplane) and... § 121.411 Qualifications: Check airmen (airplane) and check airmen (simulator). (a) For the purposes of this section and § 121.413: (1) A check airman (airplane) is a person who is qualified, and permitted...

14 CFR 121.411 - Qualifications: Check airmen (airplane) and check airmen (simulator).

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Qualifications: Check airmen (airplane) and... § 121.411 Qualifications: Check airmen (airplane) and check airmen (simulator). (a) For the purposes of this section and § 121.413: (1) A check airman (airplane) is a person who is qualified, and permitted...

14 CFR 121.411 - Qualifications: Check airmen (airplane) and check airmen (simulator).

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Qualifications: Check airmen (airplane) and... § 121.411 Qualifications: Check airmen (airplane) and check airmen (simulator). (a) For the purposes of this section and § 121.413: (1) A check airman (airplane) is a person who is qualified, and permitted...

14 CFR 121.411 - Qualifications: Check airmen (airplane) and check airmen (simulator).

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Qualifications: Check airmen (airplane) and... § 121.411 Qualifications: Check airmen (airplane) and check airmen (simulator). (a) For the purposes of this section and § 121.413: (1) A check airman (airplane) is a person who is qualified, and permitted...

[Factors Associated with Stress Check Attendance: Possible Effect of Timing of Annual Health Examination].

PubMed

Ishimaru, Tomohiro; Hattori, Michihiro; Nagata, Masako; Kuwahara, Keisuke; Watanabe, Seiji; Mori, Koji

2018-01-01

The stress check program has been part of annual employees' health screening since 2015. Employees are recommended, but not obliged, to undergo the stress check offered. This study was designed to examine the factors associated with stress check attendance. A total of 31,156 Japanese employees who underwent an annual health examination and a stress check service at an Occupational Health Service Center in 2016 participated in this study. Data from the annual health examination and stress check service included stress check attendance, date of attendance (if implemented), gender, age, workplace industry, number of employees at the workplace, and tobacco and alcohol consumption. Data were analyzed using multiple logistic regression. The mean rate of stress check attendance was 90.8%. A higher rate of stress check attendance was associated with a lower duration from the annual health examination, age ≥30 years, construction and transport industry, and 50-999 employees at the workplace. A lower rate of stress check attendance was associated with medical and welfare industry and ≥1,000 employees at the workplace. These findings provide insights into developing strategies for improving the rate of stress check attendance. In particular, stress check attendance may improve if the stress check service and annual health examination are conducted simultaneously.

Construct validity and reliability of the Single Checking Administration of Medications Scale.

PubMed

O'Connell, Beverly; Hawkins, Mary; Ockerby, Cherene

2013-06-01

Research indicates that single checking of medications is as safe as double checking; however, many nurses are averse to independently checking medications. To assist with the introduction and use of single checking, a measure of nurses' attitudes, the thirteen-item Single Checking Administration of Medications Scale (SCAMS) was developed. We examined the psychometric properties of the SCAMS. Secondary analyses were conducted on data collected from 503 nurses across a large Australian health-care service. Analyses using exploratory and confirmatory factor analyses supported by structural equation modelling resulted in a valid twelve-item SCAMS containing two reliable subscales, the nine-item Attitudes towards single checking and three-item Advantages of single checking subscales. The SCAMS is recommended as a valid and reliable measure for monitoring nurses' attitudes to single checking prior to introducing single checking medications and after its implementation. © 2013 Wiley Publishing Asia Pty Ltd.

Increasing the endogenous NO level causes catalase inactivation and reactivation of intercellular apoptosis signaling specifically in tumor cells

PubMed Central

Bauer, Georg

2015-01-01

Tumor cells generate extracellular superoxide anions and are protected against intercellular apoptosis-inducing HOCl- and NO/peroxynitrite signaling through the expression of membrane-associated catalase. This enzyme decomposes H2O2 and thus prevents HOCl synthesis. It efficiently interferes with NO/peroxynitrite signaling through oxidation of NO and decomposition of peroxynitrite. The regulatory potential of catalase at the crosspoint of ROS and RNS chemical biology, as well as its high local concentration on the outside of the cell membrane of tumor cells, establish tight control of intercellular signaling and thus prevent tumor cell apoptosis. Therefore, inhibition of catalase or its inactivation by singlet oxygen reactivate intercellular apoptosis-inducing signaling. Nitric oxide and peroxynitrite are connected with catalase in multiple and meaningful ways, as (i) NO can be oxidated by compound I of catalase, (ii) NO can reversibly inhibit catalase, (iii) peroxynitrite can be decomposed by catalase and (iv) the interaction between peroxynitrite and H2O2 leads to the generation of singlet oxygen that inactivates catalase. Therefore, modulation of the concentration of free NO through addition of arginine, inhibition of arginase, induction of NOS expression or inhibition of NO dioxygenase triggers an autoamplificatory biochemical cascade that is based on initial formation of singlet oxygen, amplification of superoxide anion/H2O2 and NO generation through singlet oxygen dependent stimulation of the FAS receptor and caspase-8. Finally, singlet oxygen is generated at sufficiently high concentration to inactivate protective catalase and to reactivate intercellular apoptosis-inducing ROS signaling. This regulatory network allows to establish several pathways for synergistic interactions, like the combination of modulators of NO metabolism with enhancers of superoxide anion generation, modulators of NO metabolism that act at different targets and between modulators of NO metabolism and direct catalase inhibitors. The latter aspect is explicitely studied for the interaction between catalase inhibiting acetylsalicylic acid and an NO donor. It is also shown that hybrid molecules like NO-aspirin utilize this synergistic potential. Our data open novel approaches for rational tumor therapy based on specific ROS signaling and its control in tumor cells. PMID:26342455

Check-In Check-Out + Social Skills: Enhancing the Effects of Check-In Check-Out for Students With Social Skill Deficits

ERIC Educational Resources Information Center

Ross, Scott W.; Sabey, Christian V.

2015-01-01

Check-In Check-Out is a Tier 2 intervention designed to reduce problem behavior and increase prosocial behavior. Although the intervention has demonstrated effects in several studies, few research efforts have considered how the intervention can be modified to support students with social skill deficits. Through a multiple baseline design across…

30 CFR 75.803-2 - Ground check systems not employing pilot check wires; approval by the Secretary.

Code of Federal Regulations, 2011 CFR

2011-07-01

... wires; approval by the Secretary. 75.803-2 Section 75.803-2 Mineral Resources MINE SAFETY AND HEALTH... Underground High-Voltage Distribution § 75.803-2 Ground check systems not employing pilot check wires; approval by the Secretary. Ground check systems not employing pilot check wires will be approved only if it...

30 CFR 77.803-2 - Ground check systems not employing pilot check wires; approval by the Secretary.

Code of Federal Regulations, 2011 CFR

2011-07-01

... wires; approval by the Secretary. 77.803-2 Section 77.803-2 Mineral Resources MINE SAFETY AND HEALTH... check systems not employing pilot check wires; approval by the Secretary. Ground check systems not employing pilot check wires shall be approved by the Secretary only if it is determined that the system...

30 CFR 77.803-2 - Ground check systems not employing pilot check wires; approval by the Secretary.

Code of Federal Regulations, 2010 CFR

2010-07-01

... wires; approval by the Secretary. 77.803-2 Section 77.803-2 Mineral Resources MINE SAFETY AND HEALTH... check systems not employing pilot check wires; approval by the Secretary. Ground check systems not employing pilot check wires shall be approved by the Secretary only if it is determined that the system...

30 CFR 75.803-2 - Ground check systems not employing pilot check wires; approval by the Secretary.

Code of Federal Regulations, 2010 CFR

2010-07-01

... wires; approval by the Secretary. 75.803-2 Section 75.803-2 Mineral Resources MINE SAFETY AND HEALTH... Underground High-Voltage Distribution § 75.803-2 Ground check systems not employing pilot check wires; approval by the Secretary. Ground check systems not employing pilot check wires will be approved only if it...

30 CFR 77.803-2 - Ground check systems not employing pilot check wires; approval by the Secretary.

Code of Federal Regulations, 2013 CFR

2013-07-01

... wires; approval by the Secretary. 77.803-2 Section 77.803-2 Mineral Resources MINE SAFETY AND HEALTH... check systems not employing pilot check wires; approval by the Secretary. Ground check systems not employing pilot check wires shall be approved by the Secretary only if it is determined that the system...