6,936 research outputs found
Technical performance and diagnostic utility of the new Elecsys (R) neuron-specific enolase enzyme immunoassay
This international multicenter study was designed to evaluate the technical performance of the new double-monoclonal, single-step Elecsys neuron-specific enolase (NSE) enzyme immunoassay (EIA) and to assess its utility as a sensitive and specific test for the diagnosis of small-cell lung cancer (SCLC). Intra and interassay coefficients of variation, determined in five control or serum specimens in six laboratories, ranged from 0.7 to 5.3 (interlaboratory median: 1.3%) and from 1.3 to 8.5 (interlaboratory median: 3.4%), respectively. Laboratory-to-laboratory comparability was excellent with respect to recovery and interassay coefficients of variation. The test was linear between 0.0 and 320 ng/ml (highest measured concentration). There was a significant correlation between NSE concentrations measured using the Elecsys NSE and the established Cobas Core NSE EIA II in all subjects (n=723) and in patients with lung cancer (n=333). However, NSE concentrations were systematically lower (approximately 9%) with the Elecsys NSE than with the comparison test. Based on a specificity of 95% in comparison with the group suffering from benign lung diseases (n=183), the cutoff value for the discrimination between malignant and benign conditions was set at 21.6 ng/ml. NSE was raised in 73.4% of SCLC patients (n=188) and was significantly higher (p<0.01) in extensive (87.8%) as opposed to limited disease (56.7%). NSE was also elevated in 16.0% of the cases with non-small cell lung cancer (NSCLC, n=374). It is concluded that the Elecsys NSE EIA is a reliable and accurate diagnostic procedure for the measurement of NSE in serum samples. The special merits of this new assay are the wide measuring range (according to manufacturers declaration up to 370 ng/ml) and a short incubation time of 18 min
Magnetically Controlled Spasmodic Accretion During Star Formation. II. Results
The problem of the late accretion phase of the evolution of an axisymmetric,
isothermal magnetic disk surrounding a forming star has been formulated in a
companion paper. The "central sink approximation" is used to circumvent the
problem of describing the evolution inside the opaque central region for
densities greater than 10^11 cm^-3 and radii smaller than a few AUs. Only the
electrons are assumed to be attached to the magnetic field lines, and the
effects of both negatively and positively charged grains are accounted for.
After a mass of 0.1 solar mass accumulates in the central cell (forming star),
a series of magnetically driven outflows and associated outward propagating
shocks form in a quasi-periodic fashion. As a result, mass accretion onto the
protostar occurs in magnetically controlled bursts. We refer to this process as
spasmodic accretion. The shocks propagate outward with supermagnetosonic
speeds. The period of dissipation and revival of the outflow decreases in time,
as the mass accumulated in the central sink increases. We evaluate the
contribution of ambipolar diffusion to the resolution of the magnetic flux
problem of star formation during the accretion phase, and we find it to be very
significant although not sufficient to resolve the entire problem yet. Ohmic
dissipation is completely negligible in the disk during this phase of the
evolution. The protostellar disk is found to be stable against interchange-like
instabilities, despite the fact that the mass-to-flux ratio has temporary local
maxima.Comment: Astrophysical Journal, in press. 29 pages, 13 figure
Avalanche to streamer transition in particle simulations
The avalanche to streamer transition is studied and illustrated in a particle
model. The results are similar to those of fluid models. However, when
super-particles are introduced, numerical artefacts become visible. This
underscores the need of models that are hybrid in space.Comment: 2 pages, 1 figur
Determining the Nonperturbative Collins-Soper Kernel From Lattice QCD
At small transverse momentum , transverse-momentum dependent parton
distribution functions (TMDPDFs) arise as genuinely nonperturbative objects
that describe Drell-Yan like processes in hadron collisions as well as
semi-inclusive deep-inelastic scattering. TMDPDFs naturally depend on the
hadron momentum, and the associated evolution is determined by the
Collins-Soper equation. For the corresponding
evolution kernel (or anomalous dimension) is nonperturbative and must be
determined as an independent ingredient in order to relate TMDPDFs at different
scales. We propose a method to extract this kernel using lattice QCD and the
Large-Momentum Effective Theory, where the physical TMD correlation involving
light-like paths is approximated by a quasi TMDPDF, defined using equal-time
correlation functions with a large-momentum hadron state. The kernel is
determined from a ratio of quasi TMDPDFs extracted at different hadron momenta.Comment: 9 pages, 2 figures; v2: extended the review of TMDPDF commonalities,
version submitted to PRD; v3: minor changes, journal versio
Diablo canyon power plant site ecological study Quarterly Report No. 1; July 1 - September 30, 1973
The second phase of ecological studies at the Diablo Canyon Power Plant site was initiated in July 1973. The first, phase conducted during 1970-71 involved baseline ecological surveys with special reference to abalone and bony fishes. The objectives of this second phase are to quantitativey monitor abalone and algal communities, including predators
and competitors, along permanent intertidal and subtidal
transects established during the first phase.
During the quarter nine permanent transects were located and marked with new buoys. Surveys on seven of these transects were completed, and the commercial sea urchin and red abalone fisheries operating in the Diablo Cove area were monitored.
Sea otter activities between Diablo Cove and Pt. Buchon were recorded to determine the location of the herd and their general food habits. Little evidence of feeding activity has been observed in Diablo Cove.
Temperature tolerance studies, began in March 1973 on red abalones, were continued. Problems in obtaining viable abalone larvae hampered this project.(11pp.
Diablo Canyon Power Plant site ecological study Quarterly Report No. 2; October 1 - December 31, 1973
During the period October 1 - December 31, 1973, Fall surveys of permanent subtidal stations were completed with one station being surveyed. We were unable to locate 3
subtidal stations.
Intertidal studies were initiated in November. A total of 12
random stations was surveyed.
Interviews were conducted with commercial abalone fishermen
working between Pt. Buchon to Pecho Rock. We continued to
monitor the sea otter herd foraging between Pt. Buchon and
Lion Rock.
Progress was achieved in the abalone temperature tolerance
studies when a successful spawning occurred. (20pp.
Electronic, magnetic and transport properties of Fe intercalated 2H-TaS studied by means of the KKR-CPA method
The electronic, magnetic and transport properties of Fe intercalated
2H-TaS have been investigated by means of the Korringa-Kohn-Rostoker (KKR)
method. The non-stoichiometry and disorder in the system has been accounted for
using the Coherent Potential Approximation (CPA) alloy theory. A pronounced
influence of disorder on the spin magnetic moment has been found for the
ferro-magnetically ordered material. The same applies for the spin-orbit
induced orbital magnetic moment and magneto-crystalline anisotropy energy. The
temperature-dependence of the resistivity of disordered 2H-FeTaS
investigated on the basis of the Kubo-St\v{r}eda formalism in combination with
the alloy analogy model has been found in very satisfying agreement with
experimental data. This also holds for the temperature dependent anomalous Hall
resistivity . The role of thermally induced lattice
vibrations and spin fluctuations for the transport properties is discussed in
detail
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