scholarly journals Changes in breath 13CO2/12CO2 consequent to exercise and hypoxia

1989 ◽  
Vol 66 (6) ◽  
pp. 2919-2919
Author(s):  
T. J. Barstow ◽  
D. M. Cooper ◽  
S. Epstein ◽  
K. Wasserman
Keyword(s):  
Substrate Oxidation ◽  
Strenuous Activity ◽  
Test Page ◽  
On Line ◽  
Endogenous Substrate

Page 936: T. J. Barstow, D. M. Cooper, S. Epstein, and K. Wasserman. “Changes in breath 13CO2/12CO2 consequent to exercise and hypoxia.” Page 936, right column, sentence beginning on line 8 should read: We therefore wondered if changes in EN could be used to detect changes in endogenous substrate oxidation during exercise. Page 940, right column, sentence beginning on line 15 should read: We controlled for potential acute modulators of oxidative fuel mix (e.g., meal and activity) by the overnight fast and avoidance of strenuous activity 24 h before each test. Page 941, left column, sentence beginning on line 27 should read: In summary, Vo2 adjusts slightly more rapidly than Vco2 in the transition from rest to exercise, whereas 13CO2 adjusts much more slowly. Page 938, Table 3 footnote should read: Values are group means for individual responses averaged from 5 to 20 min of exercise. n = 7 except for WR-3 where n = 6. Hypoxia represented FiO02, = 0.15, room air FiOO2, = 0.207. *Significantly di fferent from both WR-1 conditions and WR-2 in room air (P < 0.05). Note that work above LT (WR-2 in hypoxia and WR-3) resulted in a significant increase in R.

scholarly journals Changes in breath 13CO2/12CO2 consequent to exercise and hypoxia

1989 ◽  
Vol 66 (6) ◽  
pp. 2919-2919
Author(s):  
T. J. Barstow ◽  
D. M. Cooper ◽  
S. Epstein ◽  
K. Wasserman
Keyword(s):  
Substrate Oxidation ◽  
Strenuous Activity ◽  
Test Page ◽  
On Line ◽  
Endogenous Substrate

Page 936: T. J. Barstow, D. M. Cooper, S. Epstein, and K. Wasserman. “Changes in breath 13CO2/12CO2, consequent to exercise and hypoxia.” Page 936, right column, sentence beginning on line 8 should read: We therefore wondered if changes in EN could be used to detect changes in endogenous substrate oxidation during exercise. Page 940, right column, sentence beginning on line 15 should read: We controlled for potential acute modulators of oxidative fuel mix (e.g., meal and activity) by the overnight fast and avoidance of strenuous activity 24 h before each test. Page 941, left column, sentence beginning on line 27 should read: In summary, Vo2, adjusts slightly more rapidly than Vo2 in the transition from rest to exercise, whereas 13CO2 adjusts much more slowly. Page 938, Table 3 footnote should read: Values are group means for individual responses averaged from 5 to 20 min of exercise. n = 7 except for WR-3 where n = 6. Hypoxia represented FiO02 = 0.15, room air Fioo2 = 0.207. * Significantly different from both WR-1 conditions and WR-2 in room air (P < 0.05). Note that work above LT (WR-2 in hypoxia and WR-3) resulted in a significant increase in R.

A method for on-line measurement of wastewater organic substrate oxidation level during aerobic heterotrophic respiration

2013 ◽  
Vol 67 (8) ◽  
pp. 1809-1815
Author(s):  
E. A. Rudelle ◽  
J. Vollertsen ◽  
T. Hvitved-Jacobsen ◽  
A. H. Nielsen
Keyword(s):  
Electron Flow ◽  
Domestic Wastewater ◽  
Substrate Oxidation ◽  
Heterotrophic Respiration ◽  
Fiber Optic Sensor ◽  
Organic Substrates ◽  
Dissolved Carbon ◽  
Oxidation Level ◽  
Line Measurement ◽  
On Line

A method for on-line measurement of the organic carbon oxidation level (OXC) during aerobic heterotrophic respiration in domestic wastewater was developed and tested. The method is based on batch incubation of sewer wastewater in an intermittently aerated respirometric reactor. Between aeration cycles, measured pH, dissolved oxygen (DO) and dissolved carbon dioxide (CO2) were used to calculate electron flow accepted by DO and the resulting production of dissolved inorganic carbon (DIC). The CO2 production was measured using a novel fiber-optic sensor based on luminescence quenching. The method was tested on domestic wastewater with a relatively high pH and alkalinity. From the DO and DIC measurements, it was possible to evaluate substrate oxidation levels with a temporal resolution of less than an hour. Addition of organic substrates during the experiments confirmed the method's applicability. The substrates tested included ethanol (OXC = −2), glucose (OXC = 0) and oxalic acid (OXC = 3).

Endogenous substrate oxidation during exercise and variations in breath 13CO2/12CO2

1993 ◽  
Vol 74 (1) ◽  
pp. 133-138 ◽  
Author(s):  
J. F. Gautier ◽  
F. Pirnay ◽  
B. Jandrain ◽  
M. Lacroix ◽  
F. Mosora ◽  
...  
Keyword(s):  
Exercise Bout ◽  
Isotope Ratio Mass Spectrometry ◽  
Substrate Oxidation ◽  
Significant Rise ◽  
Total Carbohydrate ◽  
Exogenous Substrate ◽  
Major Shift ◽  
Endogenous Substrate ◽  
Endogenous Substrates ◽  
Expired Air

This study attempted to induce a major shift in the utilization of endogenous substrates during exercise in men by the use of a potent inhibitor of adipose tissue lipolysis, Acipimox, and to see to what extent this affects the 13C/12C ratio in expired air CO2. Six healthy volunteers exercised for 3 h on a treadmill at approximately 45% of their maximum O2 uptake, 75 min after having ingested either a placebo or 250 mg Acipimox. The rise in plasma free fatty acids and glycerol was almost totally prevented by Acipimox, and no significant rise in the utilization of lipids, evaluated by indirect calorimetry, was observed. Total carbohydrate oxidation averaged 128 +/- 17 (placebo) and 182 +/- 21 g/3 h (Acipimox). Conversely, total lipid oxidation was 84 +/- 5 (placebo) and 57 +/- 6 g/3 h (Acipimox; P < 0.01). Under placebo, changes in expired air CO2 delta 13C were minimal, with only a 0.49/1000 significant rise at 30 min. In contrast, under Acipimox, the rise in expired air CO2 delta 13C averaged 1/1000 and was significant throughout the 3-h exercise bout; in these conditions calculation of a "pseudooxidation" of an exogenous sugar naturally or artificially enriched in 13C, but not ingested, would have given an erroneous value of 19.8 +/- 2.6 g/3 h. Thus under conditions of extreme changes in endogenous substrate utilization, an appropriate control experiment is mandatory when studying exogenous substrate oxidation by 13C-labeled substrates and isotope-ratio mass spectrometry measurements on expired air CO2.

Redox regulation of endogenous substrate oxidation by cardiac mitochondria

2006 ◽  
Vol 291 (3) ◽  
pp. H1436-H1445 ◽  
Author(s):  
Paavo Korge ◽  
James N. Weiss
Keyword(s):  
Fatty Acids ◽  
Redox Regulation ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Substrate Oxidation ◽  
Cardiac Mitochondria ◽  
The Matrix ◽  
Endogenous Substrate ◽  
Exogenous Substrates

Reactive oxygen species (ROS) play important roles in regulating mitochondrial function, as well as in ischemia-reperfusion injury and cardioprotection. Here we show that, in the absence of exogenous substrates, cardiac mitochondria have a surprisingly large capacity to phosphorylate ADP by oxidizing endogenous substrates, provided that H2O2 is removed from the extramitochondrial environment and a reduced environment is maintained in the matrix. In isolated mitochondria without exogenous substrates, addition of catalase and the membrane-permeant reducing agent N-acetylcysteine (Nac) or the ROS scavenger mercaptopropionyl glycine significantly increased the ability to phosphorylate added ADP, as demonstrated by 1) full recovery of membrane potential (Δψ) and matrix volume from ADP-induced dissipation and shrinkage, 2) ADP-dependent increase in O2 consumption, and 3) enhanced rate of ATP synthesis. Removal of extramitochondrial H2O2 by catalase was required to stimulate endogenous substrate oxidation, as shown by the increase in O2 consumption and Δψ. This effect was greatly enhanced by addition of Nac or mercaptopropionyl glycine to suppress oxidation-induced ROS increases in the matrix. Theoretical considerations, as well as reversible inhibition of O2 consumption with 3-mercaptopropionic acid and pyruvate in state 3, indicate that these substrates are fatty acids. Under in vivo conditions in which powerful antioxidant conditions are maintained, this mechanism may be important in stimulation of β-oxidation and ATP production at low levels of extramitochondrial fatty acids. Incapacitation of this mechanism may potentially contribute to mitochondrial dysfunction during oxidative stress.

Arrangement of Mitochondria in Spermatozoa of the Mexican Axolotl, Ambystoma Mexicanum

1973 ◽  
Vol 31 ◽  
pp. 626-627
Author(s):  
Ezzatollah Keyhani ◽  
Larry F. Lemanski ◽  
Sharon L. Lemanski
Keyword(s):  
Plasma Membrane ◽  
Sperm Motility ◽  
Substrate Oxidation ◽  
Ambystoma Mexicanum ◽  
Axial Filament ◽  
Mexican Axolotl ◽  
Middle Piece

Energy for sperm motility is provided by both glycolytic and respiratory pathways. Mitochondria are involved in the latter pathway and conserve energy of substrate oxidation by coupling to phosphorylation. During spermatogenesis, the mitochondria undergo extensive transformation which in many species leads to the formation of a nebemkem. The nebemkem subsequently forms into a helix around the axial filament complex in the middle piece of spermatozoa.Immature spermatozoa of axolotls contain numerous small spherical mitochondria which are randomly distributed throughout the cytoplasm (Fig. 1). As maturation progresses, the mitochondria appear to migrate to the middle piece region where they become tightly packed to form a crystalline-like sheath. The cytoplasm in this region is no longer abundant (Fig. 2) and the plasma membrane is now closely apposed to the outside of the mitochondrial layer.

The on-line use of histogram data for high-speed correction and alignment of electron microscope images

1984 ◽  
Vol 42 ◽  
pp. 556-557
Author(s):  
William Krakow
Keyword(s):  
Power Spectrum ◽  
High Speed ◽  
Direct Memory Access ◽  
Digital Television ◽  
Contrast Transfer Function ◽  
The Past ◽  
High Resolution Tem ◽  
On Line ◽  
Correction Of Astigmatism ◽  
The Fourier Transform

In the past few years on-line digital television frame store devices coupled to computers have been employed to attempt to measure the microscope parameters of defocus and astigmatism. The ultimate goal of such tasks is to fully adjust the operating parameters of the microscope and obtain an optimum image for viewing in terms of its information content. The initial approach to this problem, for high resolution TEM imaging, was to obtain the power spectrum from the Fourier transform of an image, find the contrast transfer function oscillation maxima, and subsequently correct the image. This technique requires a fast computer, a direct memory access device and even an array processor to accomplish these tasks on limited size arrays in a few seconds per image. It is not clear that the power spectrum could be used for more than defocus correction since the correction of astigmatism is a formidable problem of pattern recognition.

Image registration with a computer driven S.T.E.M.

1978 ◽  
Vol 36 (1) ◽  
pp. 98-99
Author(s):  
A.M.H. Schepman ◽  
J.A.P. van der Voort ◽  
J.E. Mellema
Keyword(s):  
Spot Size ◽  
Scanning Transmission Electron Microscope ◽  
Small Computer ◽  
Structural Studies ◽  
Area Of Interest ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Specimen Area ◽  
On Line ◽  
Minimum Distances

A Scanning Transmission Electron Microscope (STEM) was coupled to a small computer. The system (see Fig. 1) has been built using a Philips EM400, equipped with a scanning attachment and a DEC PDP11/34 computer with 34K memory. The gun (Fig. 2) consists of a continuously renewed tip of radius 0.2 to 0.4 μm of a tungsten wire heated just below its melting point by a focussed laser beam (1). On-line operation procedures were developped aiming at the reduction of the amount of radiation of the specimen area of interest, while selecting the various imaging parameters and upon registration of the information content. Whereas the theoretical limiting spot size is 0.75 nm (2), routine resolution checks showed minimum distances in the order 1.2 to 1.5 nm between corresponding intensity maxima in successive scans. This value is sufficient for structural studies of regular biological material to test the performance of STEM over high resolution CTEM.

Design and calibration of an IVEM for general 3-dimensional imaging of non-diffracting materials

1992 ◽  
Vol 50 (2) ◽  
pp. 1040-1041
Author(s):  
Neil Rowlands ◽  
Jeff Price ◽  
Michael Kersker ◽  
Seichi Suzuki ◽  
Steve Young ◽  
...  
Keyword(s):  
3D Imaging ◽  
Tomographic Reconstruction ◽  
Three Dimensional ◽  
3 Dimensional ◽  
3D Microstructure ◽  
Image Translation ◽  
Digital Correlation ◽  
On Line ◽  
Mechanical Stage ◽  
Projection Angle

Three-dimensional (3D) microstructure visualization on the electron microscope requires that the sample be tilted to different positions to collect a series of projections. This tilting should be performed rapidly for on-line stereo viewing and precisely for off-line tomographic reconstruction. Usually a projection series is collected using mechanical stage tilt alone. The stereo pairs must be viewed off-line and the 60 to 120 tomographic projections must be aligned with fiduciary markers or digital correlation methods. The delay in viewing stereo pairs and the alignment problems in tomographic reconstruction could be eliminated or improved by tilting the beam if such tilt could be accomplished without image translation.A microscope capable of beam tilt with simultaneous image shift to eliminate tilt-induced translation has been investigated for 3D imaging of thick (1 μm) biologic specimens. By tilting the beam above and through the specimen and bringing it back below the specimen, a brightfield image with a projection angle corresponding to the beam tilt angle can be recorded (Fig. 1a).

Software pattern recognition applied to nanodiffraction patterns from a STEM instrument

1986 ◽  
Vol 44 ◽  
pp. 694-695
Author(s):  
G.Y. Fan ◽  
J.M. Cowley
Keyword(s):  
Image Processing ◽  
Pattern Recognition ◽  
Computer Software ◽  
Processing System ◽  
Light Level ◽  
Host Computer ◽  
Low Light ◽  
Image Processing System ◽  
Recent Developments ◽  
On Line

In recent developments, the ASU HB5 has been modified so that the timing, positioning, and scanning of the finely focused electron probe can be entirely controlled by a host computer. This made the asynchronized handshake possible between the HB5 STEM and the image processing system which consists of host computer (PDP 11/34), DeAnza image processor (IP 5000) which is interfaced with a low-light level TV camera, array processor (AP 400) and various peripheral devices. This greatly facilitates the pattern recognition technique initiated by Monosmith and Cowley. Software called NANHB5 is under development which, instead of employing a set of photo-diodes to detect strong spots on a TV screen, uses various software techniques including on-line fast Fourier transform (FFT) to recognize patterns of greater complexity, taking advantage of the sophistication of our image processing system and the flexibility of computer software.

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