4,702 research outputs found
Adiabatic Magnetization of Superconductors as a High-Performance Cooling Mechanism
The adiabatic magnetization of a superconductor is a cooling principle
proposed in the 30s, which has never been exploited up to now. Here we present
a detailed dynamic description of the effect, computing the achievable final
temperatures as well as the process timescales for different superconductors in
various regimes. We show that, although in the experimental conditions explored
so far the method is in fact inefficient, a suitable choice of initial
temperatures and metals can lead to unexpectedly large cooling effect, even in
the presence of dissipative phenomena. Our results suggest that this principle
can be re-envisaged today as a performing refrigeration method to access the
microK regime in nanodevices.Comment: 4 pages, 3 color figure
Spatially-distributed coverage optimization and control with limited-range interactions
This paper presents coordination algorithms for groups of mobile agents
performing deployment and coverage tasks. As an important modeling constraint,
we assume that each mobile agent has a limited sensing/communication radius.
Based on the geometry of Voronoi partitions and proximity graphs, we analyze a
class of aggregate objective functions and propose coverage algorithms in
continuous and discrete time. These algorithms have convergence guarantees and
are spatially distributed with respect to appropriate proximity graphs.
Numerical simulations illustrate the results.Comment: 31 pages, some figures left out because of size limits. Complete
preprint version available at http://motion.csl.uiuc.ed
CALCAREOUS PLANKTON BIOSTRATIGRAPHY OF THE SANTONIAN-CAMPANIAN BOUNDARY INTERVAL IN THE BOTTACCIONE SECTION (UMBRIA-MARCHE BASIN, CENTRAL ITALY)
The Bottaccione section (Umbria-Marche Basin, central Italy) was analyzed for calcareous nannofossil and planktonic foraminiferal biostratigraphy across the Santonian-Campanian boundary interval to achieve a high-resolution and updated zonation directly calibrated with magnetostratigraphy. Several calcareous plankton events were detected, including zonal markers and additional potential biohorizons. The base of magnetochron C33r, proposed for placement of the base of the Campanian, lies between the first occurrence of Aspidolithus parcus parcus and the last occurrence of Dicarinella asymetrica in the Bottaccione section. The literature survey indicates that these events were found in the Santonian-Campanian boundary interval at supraregional scale and, may be used to confidently approximate the base of the Campanian
Towards high-energy Higgs+jet distributions at NLL matched to NLO
We report progress on the study of the inclusive semi-hard hadroproduction of
a Higgs+jet system at LHC and FCC collision energies. We describe a prototype
matching procedure aimed at combining NLO fixed-order computations via POWHEG,
with the NLL resummation of energy logarithms from JETHAD. We present
preliminary analyses on assessing the weight of systematic uncertainties, such
as the ones coming from finite top- and bottom-quark masses.Comment: 6 pages, 1 figure, presented by F.G. Celiberto at the European
Physical Society Conference on High Energy Physics (EPS-HEP) 2023, 20-25
August 2023, Universit\"at Hambur
Quiet in the Operating Room! Team STEPPS and OR Distractions
Background and Objective:
From the moment that a patient enters the operating room to the time that they are brought to the post anesthesia care unit, a distraction has the potential to lead to an adverse outcome for the patient. During the critical portions of the surgery, it is even more important for all members of the operating staff to be focused and engaging in safe practices. Distractions in the operating room can hinder safe communication and potentially endanger patient safety. Team training has been shown to both improve team communication and reduce distractions.
The objective of this project was using Team STEPPS training to reduce distractions during the critical portions of surgery, defined as the time of anesthesia induction, the time out, and the time of emergence from anesthesiahttps://jdc.jefferson.edu/patientsafetyposters/1060/thumbnail.jp
A Semi Rigid Novel Hydroxamate AMPED-Based Ligand for 89Zr PET Imaging
In this work, we designed, developed, characterized, and investigated a new chelator and
its bifunctional derivative for 89Zr labeling and PET-imaging. In a preliminary study, we synthesized
two hexadentate chelators named AAZTHAS and AAZTHAG, based on the seven-membered heterocycle
AMPED (6-amino-6-methylperhydro-1,4-diazepine) with the aim to increase the rigidity of the
89Zr complex by using N-methyl-N-(hydroxy)succinamide or N-methyl-N-(hydroxy)glutaramide
pendant arms attached to the cyclic structure. N-methylhydroxamate groups are the donor groups
chosen to efficiently coordinate 89Zr. After in vitro stability tests, we selected the chelator with longer
arms, AAZTHAG, as the best complexing agent for 89Zr presenting a stability of 86.4 5.5% in
human serum (HS) for at least 72 h. Small animal PET/CT static scans acquired at different time
points (up to 24 h) and ex vivo organ distribution studies were then carried out in healthy nude
mice (n = 3) to investigate the stability and biodistribution in vivo of this new 89Zr-based complex.
High stability in vivo, with low accumulation of free 89Zr in bones and kidneys, was measured.
Furthermore, an activated ester functionalized version of AAZTHAG was synthesized to allow the
conjugation with biomolecules such as antibodies. The bifunctional chelator was then conjugated
to the human anti-HER2 monoclonal antibody Trastuzumab (Tz) as a proof of principle test of
conjugation to biologically active molecules. The final 89Zr labeled compound was characterized via
radio-HPLC and SDS-PAGE followed by autoradiography, and its stability in different solutions was
assessed for at least 4 days
Parenteral Nutrition in Liver Resection
Albeit a very large number of experiments have assessed the impact of various substrates on liver regeneration after partial hepatectomy, a limited number of clinical studies have evaluated artificial nutrition in liver resection patients. This is a peculiar topic because many patients do not need artificial nutrition, while several patients need it because of malnutrition and/or prolonged inability to feeding caused by complications. The optimal nutritional regimen to support liver regeneration, within other postoperative problems or complications, is not yet exactly defined. This short review addresses relevant aspects and potential developments in the issue of postoperative parenteral nutrition after liver resection
A survey of kernel and spectral methods for clustering
Clustering algorithms are a useful tool to explore data structures and have been employed in many disciplines. The focus of this paper is the partitioning clustering problem with a special interest in two recent approaches: kernel and spectral methods. The aim of this paper is to present a survey of kernel and spectral clustering methods, two approaches able to produce nonlinear separating hypersurfaces between clusters. The presented kernel clustering methods are the kernel version of many classical clustering algorithms, e.g., K-means, SOM and neural gas. Spectral clustering arise from concepts in spectral graph theory and the clustering problem is configured as a graph cut problem where an appropriate objective function has to be optimized. An explicit proof of the fact that these two paradigms have the same objective is reported since it has been proven that these two seemingly different approaches have the same mathematical foundation. Besides, fuzzy kernel clustering methods are presented as extensions of kernel K-means clustering algorithm. (C) 2007 Pattem Recognition Society. Published by Elsevier Ltd. All rights reserved
Water Soluble Melanin Derivatives for Dynamic Contrast Enhanced Photoacoustic Imaging of Tumor Vasculature and Response to Antiangiogenic Therapy
- …