705 research outputs found
Quantifying tumour-infiltrating lymphocyte subsets : a practical immuno-histochemical method
Background: Efficient histological quantification of tumour-infiltrating T and B lymphocyte (TIL) subsets in archival tissues would greatly facilitate investigations of the role of TIL in human cancer biology. We sought to develop such a method. Methods: Ten Ă40 digital images of 4 ÎŒ sections of 16 ductal invasive breast carcinomas immunostained for CD3, CD4, CD8, and CD20 were acquired (a total of 640 images). The number of pixels in each image matching a partition of Lab colour space corresponding to immunostained cells were counted using the âColor rangeâ and âHistogramâ tools in Adobe Photoshop 7. These pixel counts were converted to cell counts per mm2 using a calibration factor derived from one, two, three or all 10 images of each case/antibody combination. Results: Variations in the number of labelled pixels per immunostained cell made individual calibration for each case/antibody combination necessary. Calibration based on two fields containing the most labelled pixels gave a cell count minimally higher (+ 5.3%) than the count based on 10-field calibration, with 95% confidence limits â 14.7 to + 25.3%. As TIL density could vary up to 100-fold between cases, this accuracy and precision are acceptable. Conclusion: The methodology described offers sufficient accuracy, precision and efficiency to quantify the density of TIL sub-populations in breast cancer using commonly available software, and could be adapted to batch processing of image files
Can charcoal improve outcomes in COVID-19 infections?
COVID-19 infection causes considerable morbidity and mortality, especially to those who are aged, have impaired renal function and are obese. We propose to examine the potential utility of oral activated charcoal with the hypothesis that such treatment would lower absorption of microbiome derived toxins and ameliorate systemic oxidant stress and inflammation
The QUEST RR Lyrae Survey: Confirmation of the Clump at 50 kpc and Other Over-Densities in the Outer Halo
We have measured the periods and light curves of 148 RR Lyrae variables from
V=13.5 to 19.7 from the first 100 sq. degrees of the QUEST RR Lyrae survey.
Approximately 55% of these stars belong to the clump of stars detected earlier
by the Sloan Digital Sky Survey. According to our measurements, this feature
has ~10 times the background density of halo stars, spans at least 37.5 deg by
3.5 deg in right ascension and declination (>=30 by >=3 kpc), lies ~50 kpc from
the Sun, and has a depth along the line of sight of ~5 kpc (1 sigma). These
properties are consistent with the recent models that suggest it is a tidal
stream from the Sgr dSph galaxy. The mean period of the type ab variables, 0.58
d, is also consistent. In addition, we have found two smaller over-densities in
the halo, one of which may be related to the globular cluster Pal 5.Comment: 12 pages (including 4 figures). Accepted for publication in the ApJ
Letter
A combined analysis technique for the search for fast magnetic monopoles with the MACRO detector
We describe a search method for fast moving ()
magnetic monopoles using simultaneously the scintillator, streamer tube and
track-etch subdetectors of the MACRO apparatus. The first two subdetectors are
used primarily for the identification of candidates while the track-etch one is
used as the final tool for their rejection or confirmation. Using this
technique, a first sample of more than two years of data has been analyzed
without any evidence of a magnetic monopole. We set a 90% CL upper limit to the
local monopole flux of in the
velocity range and for nucleon decay
catalysis cross section smaller than .Comment: 29 pages (12 figures). Accepted by Astroparticle Physic
Final results of magnetic monopole searches with the MACRO experiment
We present the final results obtained by the MACRO experiment in the search
for GUT magnetic monopoles in the penetrating cosmic radiation, for the range
. Several searches with all the MACRO sub-detectors
(i.e. scintillation counters, limited streamer tubes and nuclear track
detectors) were performed, both in stand alone and combined ways. No candidates
were detected and a 90% Confidence Level (C.L.) upper limit to the local
magnetic monopole flux was set at the level of cm
s sr. This result is the first experimental limit obtained in
direct searches which is well below the Parker bound in the whole range
in which GUT magnetic monopoles are expected.Comment: 12 pages, Latex, 9 figures and 2 Table
Measurement of the residual energy of muons in the Gran Sasso underground Laboratories
The MACRO detector was located in the Hall B of the Gran Sasso underground
Laboratories under an average rock overburden of 3700 hg/cm^2. A transition
radiation detector composed of three identical modules, covering a total
horizontal area of 36 m^2, was installed inside the empty upper part of the
detector in order to measure the residual energy of muons. This paper presents
the measurement of the residual energy of single and double muons crossing the
apparatus. Our data show that double muons are more energetic than single ones.
This measurement is performed over a standard rock depth range from 3000 to
6500 hg/cm^2.Comment: 28 pages, 9 figure
Search for Nucleon Decays induced by GUT Magnetic Monopoles with the MACRO Experiment
The interaction of a Grand Unification Magnetic Monopole with a nucleon can
lead to a barion-number violating process in which the nucleon decays into a
lepton and one or more mesons (catalysis of nucleon decay). In this paper we
report an experimental study of the effects of a catalysis process in the MACRO
detector. Using a dedicated analysis we obtain new magnetic monopole (MM) flux
upper limits at the level of for
, based on the search for
catalysis events in the MACRO data. We also analyze the dependence of the MM
flux limit on the catalysis cross section.Comment: 12 pages, Latex, 10 figures and 2 Table
Muon Energy Estimate Through Multiple Scattering with the Macro Detector
Muon energy measurement represents an important issue for any experiment
addressing neutrino induced upgoing muon studies. Since the neutrino
oscillation probability depends on the neutrino energy, a measurement of the
muon energy adds an important piece of information concerning the neutrino
system. We show in this paper how the MACRO limited streamer tube system can be
operated in drift mode by using the TDC's included in the QTPs, an electronics
designed for magnetic monopole search. An improvement of the space resolution
is obtained, through an analysis of the multiple scattering of muon tracks as
they pass through our detector. This information can be used further to obtain
an estimate of the energy of muons crossing the detector. Here we present the
results of two dedicated tests, performed at CERN PS-T9 and SPS-X7 beam lines,
to provide a full check of the electronics and to exploit the feasibility of
such a multiple scattering analysis. We show that by using a neural network
approach, we are able to reconstruct the muon energy for 40 GeV. The
test beam data provide an absolute energy calibration, which allows us to apply
this method to MACRO data.Comment: 25 pages, 11 figures, Submitted to Nucl. Instr. & Meth.
Search for massive rare particles with MACRO
Massive rare particles have been searched for in the penetrating cosmic
radiation using the MACRO apparatus at the Gran Sasso National Laboratories.
Liquid scintillators, streamer tubes and nuclear track detectors have been used
to search for magnetic monopoles (MMs).
Based on no observation of such signals, stringent flux limits are
established for MMs as slow as a few 10^(-5)c. The methods based on the
scintillator and on the nuclear track subdetectors were also applied to search
for nuclearites. Preliminary results of the searches for charged Q-balls are
also presented.Comment: 20 pages, 9 EPS figures included with epsfi
Atmospheric neutrino induced muons in the MACRO detector
A measurement of the flux of neutrino-induced muons using the MACRO detector
is presented. Different event topologies, corresponding to different neutrino
parent energies can be detected. The upward throughgoing muon sample is the
larger event sample. The observed upward-throughgoing muons are 26% fewer than
expected and the zenith angle distribution does not fit with the expected one.
Assuming neutrino oscillations, both measurements suggest maximum mixing and
Dm2 of a few times 10-3 eV2. The other samples are due to the internally
produced events and to upward-going stopping muons. These data show a regular
deficit of observed events in each angular bin, as expected assuming neutrino
oscillations with maximum mixing, in agreement with the analysis of the
upward-throughgoing muon sample.Comment: 7 pages 6 figures to appear in the proceedings of XVIII International
Conference on Neutrino Physics and Astrophysics (Neutrino'98), Takayama,
Japan 4-9 June, 199
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