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  • 1995-1999  (4)
  • 1940-1944
  • Pericardial pressure  (2)
  • calcium phosphate  (2)
  • 1
    Digitale Medien
    Digitale Medien
    Haemodynamic and respiratory conditions during alternating and synchronous ventilation of both lungs (1996)
    Springer
    Intensive care medicine 22 (1996), S. 813-817 
    Details
    ISSN: 1432-1238
    Schlagwort(e): Alternating ventilation ; Cardiac output ; Central venous pressure ; Intrathoracic pressure ; Lung volume ; Pericardial pressure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Objective We tested the hypothesis that mean thoracic expansion (and mean lung volume) is lower during alternating ventilation (AV), i.e. ventilation of both lungs with a phase shift of half a ventilatory cycle, compared to synchronous ventilation (SV) of both lungs. As a consequence, intrathoracic pressure will be lower, causing lower, central venous pressure and higher cardiac output. Design In eight anaesthetized and paralysed piglets, differential ventilation was established by fixation of an endobronchial tube in the left main bronchus. SV and AV were sequentially applied for four and three periods, respectively, of 10 minutes each. Minute ventilation was the same during AV and SV and adapted to normocapnia. Two series of observations were performed: series 1 with intact thorax and monitoring of oesophageal pressure; series 2 after perforation of the sternum, airtight closure of the thorax and monitoring of pericardial pressure. Results In both series, mean lung volume was 16±4% lower and central venous, oesophageal (series 1) and pericardial pressures (series 2) were 0.5±0.7 mmHg lower during AV compared to SV (allp〈0.001). In series 1, aortic pressure was 5 mmHg and cardiac output 8% higher (bothp〈0.001). In series 2, cardiac output was 5% higher during AV (p〈0.001), but aortic pressure did not change (p=0.07). Conclusion Our data verified the hypothesis. The lower oesophageal (series 1), pericardial (series 2) and central venous pressures during AV compared to SV could be explained by the smaller thoracic expansion due to the lower mean lung volume, which was attributed to compression of the opposite lung by the expansion of the inflated lung.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01709526
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Haemodynamic and respiratory conditions during alternating and synchronous ventilation of both lungs (1996)
    Springer
    Intensive care medicine 22 (1996), S. 813-817 
    Details
    ISSN: 1432-1238
    Schlagwort(e): Key words Alternating ventilation ; Cardiac output ; Central venous pressure ; Intrathoracic pressure ; Lung volume ; Pericardial pressure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract   Objective: We tested the hypothesis that mean thoracic expansion (and mean lung volume) is lower during alternating ventilation (AV), i.e. ventilation of both lungs with a phase shift of half a ventilatory cycle, compared to synchronous ventilation (SV) of both lungs. As a consequence, intrathoracic pressure will be lower, causing lower, central venous pressure and higher cardiac output. Design: In eight anaesthetized and paralysed piglets, differential ventilation was established by fixation of an endobronchial tube in the left main bronchus. SV and AV were sequentially applied for four and three periods, respectively, of 10 minutes each. Minute ventilation was the same during AV and SV and adapted to normocapnia. Two series of observations were performed: series 1 with intact thorax and monitoring of oesophageal pressure; series 2 after perforation of the sternum, airtight closure of the thorax and monitoring of pericardial pressure. Results: In both series, mean lung volume was 16±4% lower and central venous, oesophageal (series 1) and pericardial pressures (series 2) were 0.5–0.7 mmHg lower during AV compared to SV (all p〈0.001). In series 1, aortic pressure was 5 mmHg and cardiac output 8% higher (both p〈0.001). In series 2, cardiac output was 5% higher during AV (p〈0.001), but aortic pressure did not change (p=0.07). Conclusion: Our data verified the hypothesis. The lower oesophageal (series 1), pericardial (series 2) and central venous pressures during AV compared to SV could be explained by the smaller thoracic expansion due to the lower mean lung volume, which was attributed to compression of the opposite lung by the expansion of the inflated lung.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01709526
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    A complete characterization of Ca5(PO4)3OH sputter-deposited films by ion beam analysis: RBS and ERD (1998)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 42 (1998), S. 266-271 
    Details
    ISSN: 0021-9304
    Schlagwort(e): calcium phosphate ; ion beam analysis ; coating ; Rutherford backscattering ; elastic recoil detection ; biomaterial ; Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Medizin , Technik allgemein
    Notizen: RF magnetron sputter deposition was used to deposit thin calcium phosphate (hydroxyapatite) layers on titanium alloy substrate material. We determined the precise amount of calcium, phosphorus, oxygen, and hydrogen in these films by combining two ion-beam analysis techniques: Rutherford backscattering spectrometry (RBS) and elastic recoil detection (ERD). Variables were power level, partial oxygen pressure, or additional water vapor. Also examined was the influence of additional bias power to the substrates during deposition and the effect of annealing on the final composition of the deposited layers. Measurements showed that the Ca/P ratio decreased with increasing oxygen pressure or decreasing sputtering power. In addition, the Ca/P ratio increased when a bias was applied to the substrates. The O/P ratio of the films decreased with additional oxygen pressure but increased when additional water vapor was applied during deposition. All as-deposited films showed a higher hydrogen content than stoichiometric HA. The hydrogen content in the films deposited with water vapor was more than 7 times higher than in the films deposited under pure argon conditions. After annealing, the hydrogen content decreased to about 3.5 at % whereas in stoichiometric HA the hydrogen content amounts to 4.5 at %. After annealing, the oxygen concentration in the film also decreased. We assume that hydrogen disappears out of the film as H2O during annealing. For the targets used in these experiments, sputter deposition at 400 W, with additional water vapor and annealing at 500°C, produced films with a stoichiometry closest to that of hydroxyapatite. © 1998 John Wiley & Sons, Inc. J Biomed Mater Res, 42, 266-271, 1998.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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    Artikel (Nationallizenzen)
  • 4
    Digitale Medien
    Digitale Medien
    Influence of rapid heating with infrared radiation on RF magnetron-sputtered calcium phosphate coatings (1997)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 37 (1997), S. 60-67 
    Details
    ISSN: 0021-9304
    Schlagwort(e): heat treatment ; calcium phosphate ; coating ; sputter ; implant ; Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Medizin , Technik allgemein
    Notizen: This study evaluated the effect of rapid heating with infrared radiation on the physico-chemical and morphological properties of radio frequent (RF) magnetron-sputtered calcium phosphate (Ca-P) coatings. About 2.5 μm thick Ca-P coatings were deposited on titanium disks and cylinders. These specimens were left untreated or were heat treated by infrared radiation at 300, 400, 500, 600, and 700°C for 4, 7, 11, 17, and 24 s. Subsequently, the specimens were immersed in simulated body fluid (SBF) for 1 day, 1 week, and 5 weeks. X-ray diffraction measurements showed that heating at 500°C or higher resulted in an increase of coating crystallinity. In addition, FT-IR measurements revealed the appearance of OH peaks in the spectra of samples treated at 500-700°C. Electron probe microanalysis showed that after 5 weeks of immersion about 40-50% of the coatings heat treated at 500 and 600°C was maintained. The coatings heat treated at 700°C showed no dissolution at all. On the other hand, as-coated and 300°C treated films were dissolved within 1 day. Scanning electron microscopy of the samples showed that directly after heat treatment no apparent cracks were present in the coatings. On the basis of these findings, we conclude that rapid heating with infrared radiation around 600°C is the best heat treatment for RF magnetron-sputtered coatings. © 1997 John Wiley & Sons, Inc. J Biomed Mater Res, 37, 60-67, 1997.
    Zusätzliches Material: 11 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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