186 research outputs found
Study of Thick CZT Detectors for X-ray and Gamma-Ray Astronomy
CdZnTe (CZT) is a wide bandgap II-VI semiconductor developed for the
spectroscopic detection of X-rays and {\gamma}-rays at room temperature. The
Swift Burst Alert Telescope is using an 5240 cm2 array of 2 mm thick CZT
detectors for the detection of 15-150 keV X-rays from Gamma-Ray Bursts. We
report on the systematic tests of thicker (\geq 0.5 cm) CZT detectors with
volumes between 2 cm3 and 4 cm3 which are potential detector choices for a
number of future X-ray telescopes that operate in the 10 keV to a few MeV
energy range. The detectors contacted in our laboratory achieve Full Width Half
Maximum energy resolutions of 2.7 keV (4.5%) at 59 keV, 3 keV (2.5%) at 122 keV
and 4 keV (0.6%) at 662 keV. The 59 keV and 122 keV energy resolutions are
among the world-best results for \geq 0.5 cm thick CZT detectors. We use the
data set to study trends of how the energy resolution depends on the detector
thickness and on the pixel pitch. Unfortunately, we do not find clear trends,
indicating that even for the extremely good energy resolutions reported here,
the achievable energy resolutions are largely determined by the properties of
individual crystals. Somewhat surprisingly, we achieve the reported results
without applying a correction of the anode signals for the depth of the
interaction. Measuring the interaction depths thus does not seem to be a
pre-requisite for achieving sub-1% energy resolutions at 662 keV.Comment: 15 pages, 11 figure
Clinical Mortality in a Large COVID-19 Cohort: Observational Study.
BACKGROUND: Northwell Health, an integrated health system in New York, has treated more than 15,000 inpatients with COVID-19 at the US epicenter of the SARS-CoV-2 pandemic.
OBJECTIVE: We describe the demographic characteristics of patients who died of COVID-19, observation of frequent rapid response team/cardiac arrest (RRT/CA) calls for non-intensive care unit (ICU) patients, and factors that contributed to RRT/CA calls.
METHODS: A team of registered nurses reviewed the medical records of inpatients who tested positive for SARS-CoV-2 via polymerase chain reaction before or on admission and who died between March 13 (first Northwell Health inpatient expiration) and April 30, 2020, at 15 Northwell Health hospitals. The findings for these patients were abstracted into a database and statistically analyzed.
RESULTS: Of 2634 patients who died of COVID-19, 1478 (56.1%) had oxygen saturation levels ≥90% on presentation and required no respiratory support. At least one RRT/CA was called on 1112/2634 patients (42.2%) at a non-ICU level of care. Before the RRT/CA call, the most recent oxygen saturation levels for 852/1112 (76.6%) of these non-ICU patients were at least 90%. At the time the RRT/CA was called, 479/1112 patients (43.1%) had an oxygen saturation of \u3c80%.
CONCLUSIONS: This study represents one of the largest reviewed cohorts of mortality that also captures data in nonstructured fields. Approximately 50% of deaths occurred at a non-ICU level of care despite admission to the appropriate care setting with normal staffing. The data imply a sudden, unexpected deterioration in respiratory status requiring RRT/CA in a large number of non-ICU patients. Patients admitted at a non-ICU level of care suffered rapid clinical deterioration, often with a sudden decrease in oxygen saturation. These patients could benefit from additional monitoring (eg, continuous central oxygenation saturation), although this approach warrants further study
Deformed Spectral Representation of the BFKL Kernel and the Bootstrap for Gluon Reggeization
We investigate the space of functions in which the BFKL kernel acts. For the
amplitudes which describe the scattering of colorless projectiles it is
convenient to define, in transverse coordinates, the Moebius space in which the
solutions to the BFKL equation vanish as the coordinates of the two reggeized
gluons coincide. However, in order to fulfill the bootstrap relation for the
BFKL kernel it is necessary to modify the space of functions. We define and
investigate a new space of functions and show explicitly that the bootstrap
relation is valid for the corresponding spectral form of the kernel. We
calculate the generators of the resulting deformed representation of the
sl(2,C) algebra.Comment: 22 pages, 1 figur
Integrated Circuit Design in US High-Energy Physics
This whitepaper summarizes the status, plans, and challenges in the area of
integrated circuit design in the United States for future High Energy Physics
(HEP) experiments. It has been submitted to CPAD (Coordinating Panel for
Advanced Detectors) and the HEP Community Summer Study 2013(Snowmass on the
Mississippi) held in Minnesota July 29 to August 6, 2013. A workshop titled: US
Workshop on IC Design for High Energy Physics, HEPIC2013 was held May 30 to
June 1, 2013 at Lawrence Berkeley National Laboratory (LBNL). A draft of the
whitepaper was distributed to the attendees before the workshop, the content
was discussed at the meeting, and this document is the resulting final product.
The scope of the whitepaper includes the following topics: Needs for IC
technologies to enable future experiments in the three HEP frontiers Energy,
Cosmic and Intensity Frontiers; Challenges in the different technology and
circuit design areas and the related R&D needs; Motivation for using different
fabrication technologies; Outlook of future technologies including 2.5D and 3D;
Survey of ICs used in current experiments and ICs targeted for approved or
proposed experiments; IC design at US institutes and recommendations for
collaboration in the future
Resectable IIIA-N2 non-small-cell lung cancer (NSCLC): In search for the proper treatment
Locally advanced non-small cell lung cancer accounts for one third of non-small cell lung cancer (NSCLC) at the time of initial diagnosis and presents with a wide range of clinical and pathological heterogeneity. To date, the combined multimodality approach involving both local and systemic control is the gold standard for these patients, since occult distant micrometastatic disease should always be suspected. With the rapid increase in treatment options, the need for an interdisciplinary discussion involving oncologists, surgeons, radiation oncologists and radiologists has become essential. Surgery should be recommended to patients with non-bulky, discrete, or single-level N2 involvement and be included in the multimodality treatment. Resectable stage IIIA patients have been the subject of a number of clinical trials and retrospective analysis, discussing the efficiency and survival benefits on patients treated with the available therapeutic approaches. However, most of them have some limitations due to their retrospective nature, lack of exact pretreatment staging, and the involvement of heterogeneous populations leading to the awareness that each patient should undergo a tailored therapy in light of the nature of his tumor, its extension and his performance status
Asymptotics and zeros of Sobolev orthogonal polynomials on unbounded supports
In this paper we present a survey about analytic properties of polynomials
orthogonal with respect to a weighted Sobolev inner product such that the
vector of measures has an unbounded support. In particular, we are focused in
the study of the asymptotic behaviour of such polynomials as well as in the
distribution of their zeros. Some open problems as well as some new directions
for a future research are formulated.Comment: Changed content; 34 pages, 41 reference
Desarrollo de resistencia a plagas y enfermedades del maiz en America del Sur - Un proyecto colaborativo.
Baseline SD-OCT characteristics of diabetic macular oedema patterns can predict morphological features and timing of recurrence in patients treated with dexamethasone intravitreal implants
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Block Toeplitz determinants, constrained KP and Gelfand-Dickey hierarchies
We propose a method for computing any Gelfand-Dickey tau function living in
Segal-Wilson Grassmannian as the asymptotics of block Toeplitz determinant
associated to a certain class of symbols. Also truncated block Toeplitz
determinants associated to the same symbols are shown to be tau function for
rational reductions of KP. Connection with Riemann-Hilbert problems is
investigated both from the point of view of integrable systems and block
Toeplitz operator theory. Examples of applications to algebro-geometric
solutions are given.Comment: 35 pages. Typos corrected, some changes in the introductio
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