650 research outputs found

    DOSE REQUIREMENTS AND PLASMA CONCENTRATIONS OF PIPECURONIUM DURING BILATERAL RENAL EXCLUSION AND ORTHOTOPIC LIVER TRANSPLANTATION IN PIGS

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    We have studied five pigs undergoing bilateral clamping of the renal pedicles, seven pigs undergoing orthotopic liver transplantation and three control animals without surgery in order to examine the roles of the kidney and liver in the plasma clearance of pipecuronium. An i.v. infusion of pipecuronium was controlled to maintain a constant 90-95 % twitch depression throughout the investigation. The right sciatic nerve was stimulated continuously with supra-maximal stimuli at 0.1 Hz and the force of the corresponding evoked isometric muscle contraction was recorded continuously. Control pigs needed an infusion rate of pipecuronium 8-10.7 ÎŒg kg−1 min−1. In the renal group, it was necessary to reduce the infusion rate of pipecuronium by about 25% after clamping both renal vascular pedicles (P < 0.05 compared with controls); in pigs undergoing liver transplantation, it was necessary to reduce the rate by approximately 80% after clamping hepatic vessels (P < 0.05 compared with controls and from the period after clamping of renal vessels). After hepatic recirculation, the infusion rate of pipecuronium was increased progressively to a rate which corresponded to 50% of baseline values (P < 0.05 compared with the anhepatic phase and from controls). Plasma concentrations of pipecuronium were comparable in the three animal groups and did not change significantly during the study. These data suggest that the liver plays a more important role than the kidney in the plasma clearance of pipecuronium in pig

    Derivation of new diagnostic reference levels for neuro-paediatric computed tomography examinations in Switzerland.

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    Definition of new national diagnostic reference levels (DRLs) for volume computed tomography dose index (CTDI &lt;sub&gt;vol&lt;/sub&gt; ) and dose length product (DLP) for neuro-paediatric CT examinations depending on the medical indication. Paediatric cranial CT data sets acquired between January 2013 and December 2016 were retrospectively collected between July 2016 and March 2017 from eight of the largest university and cantonal hospitals that perform most of the neuro-paediatric CTs in Switzerland. A consensus review of CTDI &lt;sub&gt;vol&lt;/sub&gt; and DLP was undertaken for three defined anatomical regions: brain, facial bone, and petrous bone, each with and without contrast medium application. All indications for cranial CT imaging in paediatrics were assigned to one of these three regions. Descriptive statistical analysis of the distribution of the median values for CTDI &lt;sub&gt;vol&lt;/sub&gt; and DLP yielded values in the minimum, maximum, 25th percentile (1st quartile), median (2nd quartile), and 75th percentile (3rd quartile). New DRLs for neuro-paediatric CT examinations in Switzerland were based on the 75th percentiles of the distributions of the median values of all eight centres. Where appropriate, values were rounded such that the DRLs increase or at least remain constant as the age of the patient increases. Our results revealed DRLs for CTDI &lt;sub&gt;vol&lt;/sub&gt; and DLP up to 20% lower than the DRLs used so far in Switzerland and elsewhere in Europe. This study provides Swiss neuro-paediatric CT DRL values to establish optimum conditions for paediatric cranial CT examinations. Periodic national updates of DRLs, following international comparisons, are essential

    EXPOSURE OF THE SWISS POPULATION BY RADIODIAGNOSTICS: 2013 REVIEW.

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    In 2013, a nationwide investigation was conducted in Switzerland to establish the population's exposure from medical X rays. A hybrid approach was used combining the Raddose database accessible on-line by the participating practices and the Swiss medical tariffication system for hospitals. This study revealed that the average annual number of examinations is 1.2 per inhabitant, and the associated annual effective dose is 1.4 mSv. It also showed that computed tomography is the most irradiating modality and that it delivers 70 % of the total dose. The annual effective dose per inhabitant registered a 17 % increase in 5 y and is comparable with what was recently reported in neighbouring countries

    Chylothorax after surgery on congenital heart disease in newborns and infants -risk factors and efficacy of MCT-diet

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    <p>Abstract</p> <p>Objectives</p> <p>To analyze risk factors for chylothorax in infants after congenital heart surgery and the efficacy of median chain triglyceride diet (MCT). To develop our therapeutic pathway for the management of chylothorax.</p> <p>Patients and methods</p> <p>Retrospective review of the institutional surgical database and patient charts including detailed perioperative informations between 1/2000 and 10/2006. Data analyzing with an elimination regression analysis.</p> <p>Results</p> <p>Twenty six out of 282 patients had chylothorax (=9.2%). Secondary chest closure, low body weight, small size, longer cardiopulmonary bypass (242 ± 30 versus 129 ± 5 min) and x-clamp times (111 ± 15 versus 62 ± 3 min) were significantly associated with chylothorax (p < 0.05). One patient was cured with total parenteral nutrition (TPN) and one without any treatment. 24 patients received MCT-diet alone, which was successful in 17 patients within 10 days. After conversion to regular alimentation within one week only one chylothorax relapsed. Out of 7 patients primarily not responsive to MCT-diet, 2 were successfully treated by lysis of a caval vein thrombosis, 2 by TPN + pleurodesis + supradiaphragmatic thoracic duct ligation, one by octreotide treatment, and two patients finally died.</p> <p>Conclusions</p> <p>Chylothorax may appear due to injury of the thoracic duct, due to venous or lymphatic congestion, central vein thrombosis, or diffuse injury of mediastinal lymphatic tissue in association with secondary chest closure. Application of MCT alone was effective in 71%, and more invasive treatments like TPN should not be used in primary routine. After resolution of chylothorax, MCT-diet can be converted to regular milk formula within one week and with very low risk of relapse.</p

    Search for Branons at LEP

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    We search, in the context of extra-dimension scenarios, for the possible existence of brane fluctuations, called branons. Events with a single photon or a single Z-boson and missing energy and momentum collected with the L3 detector in e^+ e^- collisions at centre-of-mass energies sqrt{s}=189-209$ GeV are analysed. No excess over the Standard Model expectations is found and a lower limit at 95% confidence level of 103 GeV is derived for the mass of branons, for a scenario with small brane tensions. Alternatively, under the assumption of a light branon, brane tensions below 180 GeV are excluded

    Study of Spin and Decay-Plane Correlations of W Bosons in the e+e- -> W+W- Process at LEP

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    Data collected at LEP at centre-of-mass energies \sqrt(s) = 189 - 209 GeV are used to study correlations of the spin of W bosons using e+e- -> W+W- -> lnqq~ events. Spin correlations are favoured by data, and found to agree with the Standard Model predictions. In addition, correlations between the W-boson decay planes are studied in e+e- -> W+W- -> lnqq~ and e+e- -> W+W- -> qq~qq~ events. Decay-plane correlations, consistent with zero and with the Standard Model predictions, are measured

    Search for Branons at LEP

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    We search, in the context of extra-dimension scenarios, for the possible existence of brane fluctuations, called branons. Events with a single photon or a single Z-boson and missing energy and momentum collected with the L3 detector in e^+ e^- collisions at centre-of-mass energies sqrt{s}=189-209$ GeV are analysed. No excess over the Standard Model expectations is found and a lower limit at 95% confidence level of 103 GeV is derived for the mass of branons, for a scenario with small brane tensions. Alternatively, under the assumption of a light branon, brane tensions below 180 GeV are excluded

    Ultrarelativistic sources in nonlinear electrodynamics

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    The fields of rapidly moving sources are studied within nonlinear electrodynamics by boosting the fields of sources at rest. As a consequence of the ultrarelativistic limit the delta-like electromagnetic shock waves are found. The character of the field within the shock depends on the theory of nonlinear electrodynamics considered. In particular, we obtain the field of an ultrarelativistic charge in the Born-Infeld theory.Comment: 10 pages, 3 figure

    Measurement of the Cross Section for Open-Beauty Production in Photon-Photon Collisions at LEP

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    The cross section for open-beauty production in photon-photon collisions is measured using the whole high-energy and high-luminosity data sample collected by the L3 detector at LEP. This corresponds to 627/pb of integrated luminosity for electron-positron centre-of-mass energies from 189GeV to 209GeV. Events containing b quarks are identified through their semi-leptonic decay into electrons or muons. The e+e- -> e+e-b b~X cross section is measured within our fiducial volume and then extrapolated to the full phase space. These results are found to be in significant excess with respect to Monte Carlo predictions and next-to-leading order QCD calculations

    Measurement of Exclusive rho^0 rho^0 Production in Two-Photon Collisions at High Q^2 at LEP

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    Exclusive rho rho production in two-photon collisions involving a single highly virtual photon is studied with data collected at LEP at centre-of-mass energies 89GeV < \sqrt{s} < 209GeV with a total integrated luminosity of 854.7pb^-1 The cross section of the process gamma gamma^* -> rho rho is determined as a function of the photon virtuality, Q^2 and the two-photon centre-of-mass energy, Wgg, in the kinematic region: 1.2GeV^2 < Q^2 < 30GeV^2 and 1.1GeV < Wgg < 3GeV
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