5,344 research outputs found
Scaling behavior of the momentum distribution of a quantum Coulomb system in a confining potential
We calculate the single-particle momentum distribution of a quantum
many-particle system in the presence of the Coulomb interaction and a confining
potential. The region of intermediate momenta, where the confining potential
dominates, marks a crossover from a Gaussian distribution valid at low momenta
to a power-law behavior valid at high momenta. We show that for all momenta the
momentum distribution can be parametrized by a -Gaussian distribution whose
parameters are specified by the confining potential. Furthermore, we find that
the functional form of the probability of transitions between the confined
ground state and the excited state is invariant under scaling of the
ratio , where is the transferred momentum and is the
corresponding excitation energy. Using the scaling variable the
maxima of the transition probabilities can also be expressed in terms of a
-Gaussian.Comment: 6 pages, 5 figure
Experimental Investigation of Loop Caused Influences on Parallel Flow-Induced Vibration of Fuel Pins
Thermo-mechanic-electrical coupling in phospholipid monolayers near the critical point
Lipid monolayers have been shown to represent a powerful tool in studying
mechanical and thermodynamic properties of lipid membranes as well as their
interaction with proteins. Using Einstein's theory of fluctuations we here
demonstrate, that an experimentally derived linear relationship both between
transition entropy S and area A as well as between transition entropy and
charge q implies a linear relationships between compressibility \kappa_T, heat
capacity c_\pi, thermal expansion coefficient \alpha_T and electric capacity
CT. We demonstrate that these couplings have strong predictive power as they
allow calculating electrical and thermal properties from mechanical
measurements. The precision of the prediction increases as the critical point
TC is approached
Two Gastropods from the Lower Cretaceous (Albian) of Coahuila, Mexico
14-22http://deepblue.lib.umich.edu/bitstream/2027.42/48381/2/ID226.pd
Non-Abelian Geometric Phases and Conductance of Spin-3/2 Holes
Angular momentum holes in semiconductor heterostructures are showed
to accumulate nonabelian geometric phases as a consequence of their motion. We
provide a general framework for analyzing such a system and compute conductance
oscillations for a simple ring geometry. We also analyze a figure-8 geometry
which captures intrinsically nonabelian interference effects.Comment: 4 pages, 3 figures (encapsulated PostScript) Replaced fig. 1 and fig.
The predictive and prognostic potential of plasma telomerase reverse transcriptase (TERT) RNA in rectal cancer patients
Background: Preoperative chemoradiotherapy (CRT) followed by surgery is the standard care for locally advanced rectal cancer,
but tumour response to CRT and disease outcome are variable. The current study aimed to investigate the effectiveness of plasma
telomerase reverse transcriptase (TERT) levels in predicting tumour response and clinical outcome.
Methods: 176 rectal cancer patients were included. Plasma samples were collected at baseline (before CRT\ubcT0), 2 weeks after
CRT was initiated (T1), post-CRT and before surgery (T2), and 4\u20138 months after surgery (T3) time points. Plasma TERT mRNA levels
and total cell-free RNA were determined using real-time PCR.
Results: Plasma levels of TERT were significantly lower at T2 (Po0.0001) in responders than in non-responders. Post-CRT TERT
levels and the differences between pre- and post-CRT TERT levels independently predicted tumour response, and the prediction
model had an area under curve of 0.80 (95% confidence interval (CI) 0.73\u20130.87). Multiple analysis demonstrated that patients with
detectable TERT levels at T2 and T3 time points had a risk of disease progression 2.13 (95% CI 1.10\u20134.11)-fold and 4.55 (95% CI
1.48\u201313.95)-fold higher, respectively, than those with undetectable plasma TERT levels.
Conclusions: Plasma TERT levels are independent markers of tumour response and are prognostic of disease progression in rectal
cancer patients who undergo neoadjuvant therapy
Critical Exponents, Hyperscaling and Universal Amplitude Ratios for Two- and Three-Dimensional Self-Avoiding Walks
We make a high-precision Monte Carlo study of two- and three-dimensional
self-avoiding walks (SAWs) of length up to 80000 steps, using the pivot
algorithm and the Karp-Luby algorithm. We study the critical exponents
and as well as several universal amplitude ratios; in
particular, we make an extremely sensitive test of the hyperscaling relation
. In two dimensions, we confirm the predicted
exponent and the hyperscaling relation; we estimate the universal
ratios , and (68\% confidence
limits). In three dimensions, we estimate with a
correction-to-scaling exponent (subjective 68\%
confidence limits). This value for agrees excellently with the
field-theoretic renormalization-group prediction, but there is some discrepancy
for . Earlier Monte Carlo estimates of , which were , are now seen to be biased by corrections to scaling. We estimate the
universal ratios and ; since , hyperscaling holds. The approach to
is from above, contrary to the prediction of the two-parameter
renormalization-group theory. We critically reexamine this theory, and explain
where the error lies.Comment: 87 pages including 12 figures, 1029558 bytes Postscript
(NYU-TH-94/09/01
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