9 research outputs found
International survey on the management of esophageal atresia
IntroductionBecause many aspects of the management of esophageal atresia (EA) are still controversial, we evaluated the practice patterns of this condition across Europe. MethodsA survey was completed by 178 delegates (from 45 [27 European] countries; 88% senior respondents) at the EUPSA-BAPS 2012. ResultsApproximately 66% of respondents work in centers where more than five EA repairs are performed per year. Preoperatively, 81% of respondents request an echocardiogram, and only 43% of respondents routinely perform preoperative bronchoscopy. Approximately 94% of respondents prefer an open approach, which is extrapleural in 71% of respondents. There were no differences in use of thoracoscopy between Europeans (10%) and non-Europeans (11%, p=nonsignificant). Approximately 60% of respondents measure the gap intraoperatively. A transanastomotic tube (90%) and chest drain (69%) are left in situ. Elective paralysis is adopted by 56% of respondents mainly for anastomosis tension (65%). About 72% of respondents routinely request a contrast study on postoperative day 7 (2-14). Approximately 54% of respondents use parenteral nutrition, 40% of respondents start transanastomotic feeds on postoperative day 1, and 89% of respondents start oral feeds after postoperative day 5. Pure EA: 46% of respondents work in centers that repair two or more than two pure EA a year. About 60% of respondents opt for delayed primary anastomosis at 3 months (1-12 months) with gastrostomy formation without esophagostomy. Anastomosis is achieved with open approach by 85% of respondents. About 47% of respondents attempt elongation of esophageal ends via Foker technique (43%) or with serial dilations with bougies (41%). Approximately 67% of respondents always attempt an anastomosis. Gastric interposition is the commonest esophageal substitution. ConclusionMany aspects of EA management are lacking consensus. Minimally invasive repair is still sporadic. We recommend establishment of an EA registry
Polarised Quark Distributions in the Nucleon from Semi-Inclusive Spin Asymmetries
We present a measurement of semi-inclusive spin asymmetries for positively
and negatively charged hadrons from deep inelastic scattering of polarised
muons on polarised protons and deuterons in the range 1
GeV. Compared to our previous publication on this subject, with the new
data the statistical errors have been reduced by nearly a factor of two.
From these asymmetries and our inclusive spin asymmetries we determine the
polarised quark distributions of valence quarks and non-strange sea quarks at
=10 GeV. The polarised valence quark distribution, , is positive and the polarisation increases with . The polarised
valence quark distribution, , is negative and the non-strange
sea distribution, , is consistent with zero over the measured
range of . We find for the first moments , and
, where we assumed
. We also determine for the first time the
second moments of the valence distributions .Comment: 17 page
Spin asymmetries A1 and structure functions g1 of the proton and the deuteron from polarized high energy muon scattering.
Adeva B, Akdogan T, Arik E, et al. Spin asymmetries A(1) and structure functions g(1) of the proton and the deuteron from polarized high energy muon scattering. Phys.Rev. D. 1998;58(11): 112001.We present the final results of the spin asymmetries A(1) and the spin structure functions g(1) of the proton and the deuteron in the kinematic range 0.0008 < x < 0.7 and 0.2 < Q(2) < 100 GeV2. For the determination of A(1), in addition to the usual method which employs inclusive scattering events and includes a large radiative background at low x, we use a new method which minimizes the radiative background by selecting events with at least one hadron as well as a muon in the final state. We find that this hadron method gives smaller errors for x < 0.02, so it is combined with the usual method to provide the optimal set of results. [S0556-2821(98)07017-9]
Measurement of the spin-dependent structure function g1(x) of the proton
Adams D, Adeva B, Arik E, et al. Measurement of the spin-dependent structure function g1(x) of the proton. Phys.Lett. B. 1994;329(2-3):399-406.We have measured the spin-dependent structure function of the proton in deep inelastic scattering of polarized muons off polarized protons, in the kinematic range and 1\,\mbox{GeV}~2
. Its first moment, , is found to be 0.136 \pm 0.011\,(\mbox{stat.})\pm 0.011\,(\mbox{syst.}) at Q~2=10\,\mbox{GeV}~2. This value is smaller than the prediction of the Ellis--Jaffe sum rule by two standard deviations, and is consistent with previous measurements. A combined analysis of all available proton, deuteron and neutron data confirms the Bjorken sum rule to within of the theoretical value
Measurement of the spin-dependent structure function g1(x) of the deuteron
Adeva B, Ahmad S, Arvidson A, et al. Measurement of the spin-dependent structure function g1(x) of the deuteron. Phys.Lett. B. 1993;302(4):533-539
The mu polarimeter for experiment SMC at CERN SPS
Baum G, Bueltmann SL, Thiel W, et al. The mu polarimeter for experiment SMC at CERN SPS. In: Adriatico Research Conference On Polarization Dynamics In Nuclear And Particle Physics. 1992
Spin Asymmetry in Muon--Proton Deep Inelastic Scattering on a Transversely-Polarized Target
We measured the spin asymmetry in the scattering of 100 GeV
longitudinally-polarized muons on transversely polarized protons. The asymmetry
was found to be compatible with zero in the kinematic range ,
1
. {}From this result we derive the upper limits for the virtual photon--proton asymmetry , and for the spin structure function . For , is significantly smaller than its positivity limit .Comment: 10 pages CERN-PPE/94-11
Polarization of valence and non-strange sea quarks in the nucleon from semi-inclusive spin asymmetries.
Adeva B, Arik E, Arvidson A, et al. Polarisation of valence and non-strange sea quarks in the nucleon from semi-inclusive spin asymmetries. Phys.Lett. B. 1996;369(1):93-100.We present a measurement of semi-inclusive spin asymmetries for positively and negatively charged hadrons from deep inelastic scattering of polarised muons on polarised protons and deuterons in the range 0.003 < x < 0.7. From these asymmetries and the previously published inclusive spin asymmetries we determine, for the first time, the x-dependent spin distributions for up and down valence quarks and for non-strange sea quarks. We find that the first moments of the valence quark spin distributions are Delta u(v) = 1.01 +/- 0.19 +/- 0.14 and Delta d(v) = -0.57 +/- 0.22 +/- 0.11. The spin distribution function of non-strange sea quarks is consistent with zero over the measured range of x and the first moment is Delta (u) over bar = Delta (d) over bar = -0.02 +/- 0.09 +/- 0.03
Nucl.Instrum.Meth. A
Adams D, Adeva B, Arik E, et al. A large Streamer Chamber muon tracking detector in a high-flux fixed-target application. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 1999;435(3):354-374.Arrays of limited streamer tubes of the Iarocci type were deployed in our experiment at CERN as part of a forward muon detector system with provisions for the beam to pass through the center of each panel in the array. A total of 16 4 m x 4 m panels were assembled with inductive readout strips on both sides of each panel. An active feedback system. was deployed to regulate the high voltage to the streamer tubes to insure a constant efficiency for minimum ionizing particles. The arrays were operated in this environment for over five years of data taking. Streamer tube track-reconstruction efficiencies and tube replacement rates are reported. (C) 1999 Elsevier Science B.V. All rights reserved