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  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 66 (1995), S. 501-503 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Multiposition tangential Thomson scattering makes it possible to measure the profiles of the local drift velocity and current density of a tokamak plasma. To achieve a reasonably small observational error (20%) a high photon yield is required. In this paper we propose an optical system to increase the photon yield by about a factor of 7. Photons from a pulsed ruby laser are captured in a ring cavity by means of an electro-optical switch. The trapped laser beam recirculates about 14 times through the sampling volume which is part of the cavity, increasing the laser energy of 25 J to an effective energy of about 140 J. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A high resolution multiposition Thomson scattering setup to measure the electron temperature (Te) and density (ne) of a hot plasma is described. The system is operational at the Rijnhuizen Tokamak Project. Light from a high power pulsed ruby laser is scattered by the free plasma electrons and relayed to a Littrow polychromator for spectral analysis. The spectrally and spatially resolved light is detected by a GaAsP photocathode. The two-dimensional image is intensified and recorded with a charge-coupled device camera.Te in the range of 50 eV–6 keV can be measured at 115 spatial elements of 2.6 mm length along the laser beam. The observation error is 〈6% at ne=2×1019 m−3 and smaller for higher ne. The high resolution and accuracy enabled the observation of small scale structures in Te and ne. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: PROMT is a system for multiposition Thomson scattering in use at the Rijnhuizen Tokamak Project tokamak. Light from a ruby laser is scattered by the free electrons in the plasma and is collected along a vertical chord of 180 mm. Electron temperature and density profiles can be measured resolving up to 36 spatial elements. Scattered light is spectrally analyzed by a Littrow polychromator and subsequently detected with an intensified charge coupled device camera. At densities of 2×1019 m−3 electron temperatures in the range of 50 eV–3 keV can be measured with an accuracy of ∼5%.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 70 (1999), S. 1999-2011 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: At the Rijnhuizen tokamak project a double pulse multiposition Thomson scattering diagnostic has been operational since 1996. It has been installed for the study of small scale structures in electron temperature (Te) and density (ne). This diagnostic measures Te and ne with high spatial resolution (3 mm full width at half maximum, i.e., 2% of the minor radius) and high accuracy (3%–4% of Te and 2%–3% of ne in the range of 50 eV–6 keV and ne=5×1019 m−3.) In this article an extensive error analysis is performed on both statistical and systematic deviations. It is found that the instrument function of the detection branch has a smoothing effect on the noise. This reduces the statistical error on the Te and ne measurements on each spatial position, because the resolution of the instrument is oversampled. The long tail of the instrument profile of the entire diagnostic has a significant effect on the systematic deviations in the Te and ne determination. However, it does not affect the relative size of the small scale structures on Te and ne, and for this this reason does not hamper the study of these structures. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: In this article, the recent installed multiposition Thomson scattering (TS) of the TJ-II stellarator is presented. Light from a pulsed ruby laser is scattered by the free electrons of the plasma and led to a spectrometer for spectral analysis. The Doppler broadened spectrum of the scattered light is analyzed with a spectrometer in the Littrow configuration, detected with a GaAsP image intensifier and recorded with two intensified charged coupled device cameras. Values of the electron temperature (Te) in the range of 50 eV up to 4 keV can be measured at 160 spatial elements of 2.25 mm along a chord of 360 mm. First results show that the observational error for Te is close to the expected error of ∼10% at an electron density (ne) of 1×1019 m−3 using a laser energy of 8 J. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: In the Rijnhuizen tokamak project, the double pulse multiposition Thomson scattering diagnostic is in full operation. Its high spatial resolution enables the measurement of small scale structures in Te, ne, and pe. Thomson scattering profiles during an ordinary sawtooth crash show the displacement of the hot core in great detail. Measurements on off-axis sawtoothing plasmas show that a small central part remains unaffected. Filaments are observed in plasmas which show a transient central temperature rise in response to fast edge cooling. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: In this article a double pulse multiposition Thomson scattering diagnostic, under construction at RTP, is discussed. Light from a double pulsed ruby laser (pulse separation: 10–800 μs, max. 2×12.5 J) is scattered by the free electrons of the tokamak plasma and relayed to a Littrow polychromator for spectral analysis. The spectrally resolved light is recorded by two ICCD detectors. Simulations show that the system sensitivity will be such that electron temperatures in the range of 100 eV–7 keV can be determined with an accuracy as good as 2%–3% for electron densities of 1020 m−3, with a spatial resolution down to 2.6 mm. With this diagnostic the dynamics of small scale structures in the electron temperature profile will be studied. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1432-0983
    Keywords: Key words Mitochondria ; Ribosomal RNA ; RNA editing ; Polycistronic transcription
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Northern analyses and reverse transcription-polymerase chain reaction (RT-PCR) experiments were performed on total RNA of Dictyostelium discoideum. The mitochondrial genes encoding the small subunit ribosomal RNA (SSU), cytochrome b (CYTB) and subunit 3 of the NADH dehydrogenase (ND3) were found to be co-transcribed. Further post-transcriptional processing resulted in a dicistronic transcript for CYTB and ND3, and a monocistronic SSU transcript. Markedly higher steady state transcript levels were detected for the mature SSU ribosomal RNA. A comparison of the SSU cDNA sequence with the mitochondrial DNA sequence of the SSU gene revealed C-to-U substitutional editing of the SSU ribosomal RNA at a single site, as a consequence of which the cDNA contained a PvuII site not present in the genomic DNA. The editing was shown to be highly efficient and to occur in the primary transcript before the release of the mature mRNA, rRNA and tRNAs. It is suggested that the editing may be required for normal pseudoknot formation in the 530 loop of the RNA and thus is important for efficient, accurate translation in the mitochondria.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Surgical endoscopy and other interventional techniques 13 (1999), S. 980-984 
    ISSN: 1432-2218
    Keywords: Key words: Rectal cancer — Preoperative staging — Endorectal ultrasound — Preoperative radiochemotherapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Objectives: Factors limiting the accuracy of endorectal ultrasound in staging, locally advanced primary rectal cancer after preoperative neoadjuvant radiochemotherapy (RCT) were evaluated. Methods: Patients (n= 84) with initial locally advanced rectal cancer (uT3/uT4) undergoing R0 resection were investigated after preoperative treatment that combined radiotherapy up to 45 Gy with two cycles of chemotherapy (5-FU and leucovorin on d 1–5 and 22–28). At 4 to 6 weeks after completion of RCT and before tumor resection, preoperative endoluminal ultrasound was performed. Results: The accuracy to predict the depth of tumor infiltration (T-category) was found to correlate with downstaging. The T-category was correctly staged before surgery in 15 of the 51 responders (29%) and in 27 of 33 nonresponders (82%), whereas misinterpretation occurred in 36 of the responders (71%) and in 6 of the nonresponders (18%) (p 〈 0.001). Neither tumor distance from anal verge nor tumor location correlated with the staging accuracy. Lymph node involvement was correctly assessed in 48 patients (57%). Wall invasion was correctly ascertained in 42 patients (50%), with under estimation in 11 patients (13%) and overestimation in 31 patients (37%). Conclusions: After radiochemotherapy, endosonography does not provide a satisfactory accuracy for preoperative staging of rectal cancer. New interpretation and diagnostic criteria are needed for the prediction of treatment response.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    European journal of nutrition 30 (1991), S. 131-137 
    ISSN: 1436-6215
    Keywords: D-Laktat ; Joghurt ; Mahlzeiteneinfluß ; D-lactate ; yogurt ; ingestion effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary The risk of D-lactic acidosis after consumption of yogurt was investigated in seven healthy volunteers. After ingestion of yogurt containing 1.06 mmol/kg body weight, D-lactic acid postprandial plasma D-lactate concentrations increased from 0.070±0.020 to a maximum of 0.200±0.010 mmol/l within 60 min. That was half the maximum concentration after the equivalent amount of D-lactate in the form of an aqueous solution of DL-lactate. The shape of the postprandial plasma D-lactate peak was flatter, but much broader after yogurt than after the aqueous solution, the peak areas being equal. When 0.64 mmol/kg body weight D-lactate were consumed as yogurt, plasma concentrations amounted to 0.086±0.030 mmol/l. Signs of a mild, transient, compensated metabolic acidosis, which was apparent in case of the aqueous lactic acid solution did not occur in case of yogurt. It is concluded that the consumption of foods containing D-lactic acid gives no reason for concern in healthy adults.
    Notes: Zusammenfassung Das Risiko einer D-Laktat-Azidose durch Joghurtverzehr wurde bei 7 gesunden Probanden untersucht. Nach dem Verzehr von Joghurt, der eine Aufnahme von 1,06 mmol/kg Körpergewicht D-Milchsäure bewirkte, stiegen die postprandialen Plasma-D-Laktat-Spiegel innerhalb von 60 min von 0,070±0,020 auf einen Höchstwert von 0,200±0,010 mmol/l an. Ein doppelt so hoher Anstieg der postprandialen Plasma-D-Laktat-Konzentrationen wurde nach Verabreichung der äquivalenten Menge D-Milchsäure in Form einer wäßrigen Lösung von DL-Laktat beobachtet. Die postprandialen Plasma-D-Laktat-Maxima fielen nach Joghurt flacher und breiter aus, während die Kurvenflächen unabhängig von der Zufuhrform waren. Nach dem Verzehr von 0,64 mmol/kg Körpergewicht D-Milchsäure in Joghurt stiegen die D-Laktat-Konzentrationen im Plasma bis auf 0,086±0,030 mmol/l an. Anzeichen einer geringfügigen, vorübergehenden, kompensierten metabolischen Azidose nach Zufuhr der wäßrigen D-Milchsäure-Lösung wurden nach Verzehr von Joghurt nicht beobachtet. Aus diesen Ergebnissen wird der Schluß gezogen, daß der Verzehr D-Milchsäure-haltiger Lebensmittel für gesunde Erwachsene unbedenklich ist.
    Type of Medium: Electronic Resource
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