Small human lung specimens are frequently used for cell biological studies of the pathogenesis of emphysema. In general, lung function and other clinical parameters are used to establish the presence ...and severity of emphysema/chronic obstructive pulmonary disease without morphological analysis of the specimens under investigation. In this study we compared three morphological methods to analyze emphysema, and evaluated whether clinical data correlate with the morphological data of individual lung samples. A total of 306 lung specimens from resected lung(lobes) from 221 patients were inflated and characterized using three morphological parameters: the Destructive Index, the Mean Linear Intercept, and Section Assessment. Morphological data were related to each other, to lung function data, and to smoking behavior. Significant correlations (P < .001) were observed between Section Assessment and Destructive Index (r = 0.92), Mean Linear Intercept with Destructive Index (r = 0.69) and Mean Linear Intercept with Section Assessment (r = 0.65). Section Assessment, being much less time consuming than Mean Linear Intercept and Destructive Index, is the parameter of choice for initial analysis. Destructive Index is the most sensitive parameter. There was a significant (P < .001), but weak correlation for all three parameters with the diffusion capacity for CO (KCO) (Destructive Index: r = −0.28; Mean Linear Intercept: r = −0.34; Section Assessment: r = −0.32), and with FEV1/IVC (Destructive Index: r = −0.29; Mean Linear Intercept: r = −0.33; Section Assessment: r = −0.28), but not with other lung function parameters. A significant difference (P < .05) between (ex-) smokers and never-smokers was observed for Destructive Index and Section Assessment. It is concluded that the application of the three morphological parameters represents a useful method to characterize emphysematous lesions in a (semi-)quantitative manner in small human lung specimens, and that Section Assessment is a suitable and fast method for initial screening. The extent of emphysema of individual lung specimens should be established by means of morphometry, rather than lung function data.
A measurement of the proton spin structure function g1p(x,Q{sup 2}) in deep-inelastic scattering is presented. The data were taken with the 27.6 GeV longitudinally polarised positron beam at HERA ...incident on a longitudinally polarised pure hydrogen gas target internal to the storage ring. The kinematic range is 0.021<x<0.85 and 0.8 GeV{sup 2}<Q{sup 2}<20 GeV{sup 2}.
The spin-momentum correlation parameter A(V)(ed) was measured for the 2H-->(e-->,e'p)n reaction for missing momenta up to 350 MeV/c at Q2 = 0.21 (GeV/c)(2) for quasielastic scattering of polarized ...electrons from vector-polarized deuterium. The data give detailed information about the deuteron spin structure and are in good agreement with the results of microscopic calculations based on realistic nucleon-nucleon potentials and including various spin-dependent reaction mechanism effects. The experiment reveals in a most direct manner the effects of the D state in the deuteron ground-state wave function and shows the importance of isobar configurations for this reaction.
Performance of a hydrogen/deuterium polarized gas target in a storage ring van Buuren, L.D.; Szczerba, D.; van den Brand, J.F.J. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2001, Letnik:
474, Številka:
3
Journal Article
Recenzirano
The performance of a high-density polarized hydrogen/deuterium gas target internal to a medium-energy electron storage ring is presented. Compared to our previous electron scattering experiments with ...tensor-polarized deuterium at NIKHEF (Zhou et al., Nucl. Instr. and Meth. A 378 (1996) 40; Ferro-Luzzi et al., Phys. Rev. Lett. 77 (1996) 2630; Van den Brand et al., Phys. Rev. Lett. 78 (1997) 1235; Bouwhuis et al., Phys. Rev. Lett. 82 (1999) 687; Zhou et al., Phys. Rev. Lett. 82 (1999) 687) the target figure of merit, (
polarization)
2×
luminosity, was improved by more than an order of magnitude. The target density was increased by upgrading the flux of nuclear-polarized atoms injected into the storage cell and by using a longer
(60
cm)
and colder
(∼70
K)
storage cell. A maximal target thickness of
1.2
(1.1)±0.1×10
14
nuclei/
cm
2
was achieved with deuterium (hydrogen). With typical beam currents of
110
mA
, this corresponds to a luminosity of about
8.4
(7.8)±0.8×10
31
e
−
nuclei
cm
−2
s
−1
. By reducing the molecular background and using a stronger target guide field, a higher polarization was achieved. The target was used in combination with a
720
MeV
polarized electron beam stored in the AmPS ring (NIKHEF) to measure spin observables in electron–proton and electron–deuteron scattering. Scattered electrons were detected in a large acceptance magnetic spectrometer. Ejected hadrons were detected in a single time-of-flight scintillator array. The product of beam and target vector polarization,
P
e
P
t, was determined from the known spin-correlation parameters of
e′
p quasi-elastic (or elastic) scattering. With the deuterium (hydrogen) target, values up to
P
e
P
t=0.49±0.03 (0.32±0.03) were obtained with an electron beam polarization of
P
e=0.62±0.04 (0.56±0.03) as measured with a Compton backscattering polarimeter (Passchier et al., Nucl. Instr. and Meth. A 414 (1998) 4988). From this, we deduce a cell-averaged target polarization of
P
t=0.78±0.07 (0.58±0.07), including the dilution by unpolarized molecules.
The Beetle is a 128 channel analog pipelined readout chip which is intended for use in the silicon vertex locator (VELO) of the LHCb experiment at CERN. The Beetle chip is specially designed to ...withstand high radiation doses.
Two Beetle1.1 chips bonded to a silicon strip detector have been tested with minimum ionizing particles. The main goal was to measure the signal-to-noise (S/N) ratio of the Beetle1.1 connected to a prototype VELO detector. Furthermore we investigated the general behaviour of the Beetle1.1. In this note we present the chip architecture, the measured (S/N) numbers as well as some characteristics (e.g. risetime, spillover) of the Beetle1.1 chip. Results from a total ionizing dose irradiation test are reported.
We report on measurements of the cross section and provide first data on spin correlation parameters A(TT') and A(TL') in inclusive scattering of longitudinally polarized electrons from ...nuclear-polarized hydrogen. Polarized electrons were injected into an electron storage ring operated at a beam energy of 720 MeV. Polarized hydrogen was produced by an atomic beam source and injected into an open-ended cylindrical cell, located in the electron storage ring. The four-momentum transfer squared ranged from Q2 = 0.2 GeV(2)/c(2) at the elastic scattering peak to Q2 = 0.11 GeV(2)/c(2) at the Delta(1232) resonance. The data provide a stringent test of pion electroproduction models.
A high-brightness hydrogen/deuterium atomic beam source is presented. The apparatus, previously used in electron scattering experiments with tensor-polarized deuterium (Ferro-Luzzi et al., Phys. Rev. ...Lett. 77 (1996) 2630; van den Brand et al., Phys. Rev. Lett. 78 (1997) 1235; Zhou et al., Phys. Rev. Lett. 82 (1998) 687; Bouwhuis et al., Phys. Rev. Lett. 82 (1999) 3755), was configured as a source for internal target experiments to measure single- and double-polarization observables, with either polarized hydrogen or vector/tensor polarized deuterium. The atomic beam intensity was enhanced by a factor of ∼2.5 by optimizing the Stern–Gerlach focusing system using high tip-field
(∼1.5
T)
rare-earth permanent magnets, and by increasing the pumping speed in the beam-formation chamber. Fluxes of
(5.9±0.2)×10
16
1
H/s
were measured in a
∅12
mm×122
mm
compression tube with its entrance at a distance of 27 cm from the last focusing element. The total output flux amounted to
(7.6±0.2)×10
16
1
H/s
.
The dependence on Q{sup 2} (the negative square of the 4-momentum of the exchanged virtual photon) of the generalised Gerasimov-Drell-Hearn integral for the proton has been measured in the range 1.2 ...GeV{sup 2}<Q{sup 2}<12 GeV{sup 2} by scattering longitudinally polarised positrons on a longitudinally polarised hydrogen gas target. The contributions of the nucleon-resonance and deep inelastic regions to this integral have been evaluated separately. The latter has been found to dominate for Q{sup 2}>3 GeV{sup 2}, while both contributions are important at low Q{sup 2}. The total integral shows no significant deviation from a 1/Q{sup 2} behavior in the measured Q{sup 2} range, and thus no sign of large effects due to either nucleon-resonance excitations or nonleading twist.
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