Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Elastic pressure-volume curves of the respiratory system reveal a high tendency to lung collapse in young pigs (1999)
    Springer
    Intensive care medicine 25 (1999), S. 1140-1146 
    Details
    ISSN: 1432-1238
    Keywords: Key words Animal ; Porcine ; Mechanics ; Compliance ; Elastic recoil ; Recruitment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Objective: To study pressure-volume (P/V) curves over a wide pressure and volume range in pigs.¶Design: Dynamic and static P/V curves (Pdyn/V and Pst/V) and compliance of the respiratory system were studied. The effects of recruitment, positive end-expiratory pressure (PEEP) and body position were analysed.¶Setting: Research animal laboratory.¶Materials: Seven anaesthetised, paralysed and ventilated healthy pigs of 21 kg.¶Measurements: P/V curves up to a pressure of about 40 cmH2O were recorded with a computer-controlled ventilator. Pst/V curves were obtained with the static occlusion method and Pdyn/V curves during an insufflation at a low, constant flow rate.¶Results: Pdyn/V recording showed a complex pattern. During the insufflation compliance increased, fell, increased and fell again. A 2nd ¶Pdyn/V recording immediately following the 1st one was displaced towards higher volumes and showed only one maximum of compliance. The difference between the two curves reflected: (1) lung collapse during a period of 5 min of ventilation at zero end-expiratory pressure (ZEEP) following a recruitment manoeuvre, (2) recruitment during the measurement of the 1st Pdyn/V curve. These observations were similar in the supine and in the left lateral position. After ventilation at PEEP, 4 cmH2O, the signs of collapse and recruitment were reduced. It was confirmed that PEEP offers a partial protection against collapse. Pst/V curves showed higher volumes and higher compliance values compared to Pdyn/V curves. This reflects the influence of viscoelastance on Pdyn/V curves.¶Conclusion: The study demonstrates a particularly strong tendency to lung collapse in pigs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001340051026
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Aspiration of dead space allows normocapnic ventilation at low tidal volumes in man (1999)
    Springer
    Intensive care medicine 25 (1999), S. 674-679 
    Details
    ISSN: 1432-1238
    Keywords: Key words Mechanical ventilation ; Dead space ; Airway pressure ; Barotrauma ; Tracheal gas insufflation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Objective: Aspiration of dead space (ASPIDS) improves carbon dioxide (CO2) elimination by replacing dead space air rich in CO2 with fresh gas during expiration. The hypothesis was that ASPIDS allows normocapnia to be maintained at low tidal volumes (VT). Design: Prospective study. Setting: Adult intensive care unit in a university hospital. Patients: Seven patients ventilated for neurological reasons were studied. All patients were clinically and haemodynamically stable and monitored according to clinical needs. Interventions: ASPIDS implies that, during expiration, gas is aspirated through a catheter inserted in the tracheal tube. Simultaneously, a compensatory flow of fresh gas is injected into the inspiratory line. ASPIDS was achieved with a computer/ventilator system controlling two solenoid valves for aspiration and injection. Results: At the basal respiratory rate of 12.6 breaths min–1, with ASPIDS VT decreased from 602 to 456 ml, as did the airway pressures to a corresponding degree. PaCO2 and PaO2 remained stable. At a frequency of 20 breaths min–1, with ASPIDS VT was further reduced to 305 ml with preserved normocapnia. ASPIDS did not interfere with the positive end-expiratory pressure (PEEP) level. No intrinsic PEEP developed. All patients remained stable. No haemodynamic or other side effects of ASPIDS were noticed. Conclusion: The results of this study suggest that ASPIDS may be a useful and safe modality of mechanical ventilation that limits alveolar pressure and minute ventilation requirements while keeping PaCO2 constant.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001340050929
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Nuclear Halos (1995)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Nuclear and Particle Science 45 (1995), S. 591-634 
    Details
    ISSN: 0163-8998
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1146/annurev.ns.45.120195.003111
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Anaphylactic bronchoconstriction in immunized guinea pigs provoked by inhalation and intravenous administration of hexahydrophthalic anhydride and methyltetrahydrophthalic anhydride (1997)
    Oxford, UK : Blackwell Publishing Ltd
    Allergy 52 (1997), S. 0 
    Details
    ISSN: 1398-9995
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: We established a guinea-pig model of anaphylactic bronchoconstriction provoked in immunized animals by inhalation and intravenous administration of 4,4-methyltetrahydrophthalic anhydride (MTHPA) and hexahydrophthalic anhydride (HHPA). Guinea pigs were immunized intradermally with either MTHPA (n= 8) or HHPA (n= 8) suspended in olive oil. Control animals (n= 8) were injected with olive oil alone. After 4 weeks, the animals were challenged during mechanical ventilation by inhalation or intravenous administration of MTHPA or HHPA conjugated with guinea-pig serum albumin (GPSA). Airway flow, and airway and esophageal pressures were measured. Resistance (R) and static compliance (Cst) of the respiratory system (rs), lung (1), and chest wall were studied with the flow-interruption technique. After challenge with MTHPA-GPSA or HHPA-GPSA, R, rs and R, 1 increased dramatically while Cst, rs and Cst,1 decreased, and severe arterial hypoxia developed. The reaction occurred at a well-defined dose of anhydride and lasted about 30 min. When the same dose was repeated after 30 min, the response was much attenuated. MTHPA and HHPA can induce asthma in guinea pigs. The dose-response curve at antigen challenge is steep. Once a threshold dose is reached, a severe reaction occurs. The reactivity is then exhausted. This model may be suitable for assessing occupational asthma caused by acid anhydrides and possibly by other low-molecular-weight chemicals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1398-9995.1997.tb02541.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    The β+-electron capture decay of 73Kr (1999)
    Springer
    The European physical journal 5 (1999), S. 143-150 
    Details
    ISSN: 1434-601X
    Keywords: PACS: 21.10.Hw Spin, parity, and isobaric spin – 23.20.Lv Gamma transitions and level energies – 23.40.Hc Relation with nuclear matrix elements and nuclear structure – 27.50.+e 59 ≤ A ≤ 89
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract: The β+– electron capture decay of 73Kr, produced at the ISOLDE CERN facility, has been studied by β-delayed proton and gamma emission. The established decay scheme involves 15 up to now unreported gamma emitting levels in 73Br. The total proton branching ratio has been measured to be 0.0025 ± 0.0003. From this work, a spin and parity 3/2− is assigned to the 73Kr ground state, on the basis of the allowed β branch to the 73Br Jπ= 1/2− ground state and the feeding of the 5/2+ level located at 286 keV in 73Br.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s100500050270
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Projectile Coulomb excitation with fast radioactive beams (1995)
    Springer
    The European physical journal 352 (1995), S. 397-401 
    Details
    ISSN: 1434-601X
    Keywords: 23.20.Ck ; 27.20.+n
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We report a search for γ rays emanating from Coulomb excitation of fast (30–46 MeV/u) radioactive projectiles8He,11,12,14Be interacting with a lead target. These are clearly identified by their Doppler shift. The 320 keV 1/2− → 1/2+ γ transition from11Be was observed with a cross-section of 191±26 mb which is noticeably less than expected from the known lifetime and in the perturbation limit of pure Coulomb excitation. In the other nuclei rather stringent upper limits of 0.01 to 0.2 Weisskopf units, are placed on the hypothetical transition to 1− states.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01299757
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Numerical analysis of pressure and flow pulsations in a segment of the arterial tree (1971)
    Springer
    Medical & biological engineering & computing 9 (1971), S. 431-445 
    Details
    ISSN: 1741-0444
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Description / Table of Contents: Sommaire La pression du sang artériel et la proportion de pulsations du volume ont été mésurées expérimentalement comme fonctions de temps, pour un segment du bras humain. En utilisant ces courbes et un type de programme d'identification, commun dans les vérifications techniques, on a calculé un modèle mathématique pour l'arbre artériel inclu dans le segment. Ce modèle mathématique mena à la construction d'un circuit électrique analogue, pour simuler la dépendance du temps de la proportion de pulsations du volume sur la pression artérielle. Dans les deux cas les résultats montrent un accord étroit entre les courbes simulées et les courbes physiologiques déterminées expérimentalement. L'inertie du sang et des vaisseaux paraît être négligeable, tandis que les adaptations non-linéaires doivent être inclues quand on utilise des vastes rangées de pression.
    Abstract: Zusammenfassung Der Arterienblutdruck und die Geschwindigkeit des Volumenpulsierens wurden experimentell für ein Segment des menschlichen Arms als Funktionen der Zeit gemessen. Unter verwendung dieser Kurven und einer Art von Identifizierungsprogramm, das in der Regeltechnik üblich ist, wurde ein mathematisches Modell für den, in das Segment eingeschlossenen Arterienbaum berechnet. Dieses mathematische Modell führte zu dem Entwurf einer analogen elektrischen Schaltung zur Nachahmung der zeitlichen Abhängigkeit der Geschwindigkeit des Raumpulsierens von dem Arteriendruck. In beiden Fällen geben die Resultate eine naheliegende Übereinstimmung zwischen den nachgeahmten Kurven und den experimentell ermittelten, physiologischen Kurven. Es wird gezeigt, dass die Trägheit von Blut und Gefässen unbedeutend ist, während nicht-lineare Nachgiebigkeit berücksichtigt werden muss, wenn es sich um grosse Druckbereiche handelt.
    Notes: Abstract The arterial blood pressure and the rate of volume pulsations were measured experimentally as functions of time for a segment of the human arm. Using these curves and a type of identification program, common in control engineering, a mathematical model was calculated for the arterial tree included in the segment. This mathematical model led to the construction of an electrical analogue circuit for simulating the time-dependence of the rate of volume pulsations on the arterial pressure. In both cases the results show a close agreement between the simulated curves and the physiological curves determined experimentally. The inertia of blood and vessels is shown to be negligible, while non-linear compliances must be included when dealing with wide pressure ranges.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02474702
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...