103 research outputs found
Pulsed EPR Distance Measurements Resolve the Impact of Site-Specific Calmodulin Methionine Oxidation
The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe
The preponderance of matter over antimatter in the early Universe, the
dynamics of the supernova bursts that produced the heavy elements necessary for
life and whether protons eventually decay --- these mysteries at the forefront
of particle physics and astrophysics are key to understanding the early
evolution of our Universe, its current state and its eventual fate. The
Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed
plan for a world-class experiment dedicated to addressing these questions. LBNE
is conceived around three central components: (1) a new, high-intensity
neutrino source generated from a megawatt-class proton accelerator at Fermi
National Accelerator Laboratory, (2) a near neutrino detector just downstream
of the source, and (3) a massive liquid argon time-projection chamber deployed
as a far detector deep underground at the Sanford Underground Research
Facility. This facility, located at the site of the former Homestake Mine in
Lead, South Dakota, is approximately 1,300 km from the neutrino source at
Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino
charge-parity symmetry violation and mass ordering effects. This ambitious yet
cost-effective design incorporates scalability and flexibility and can
accommodate a variety of upgrades and contributions. With its exceptional
combination of experimental configuration, technical capabilities, and
potential for transformative discoveries, LBNE promises to be a vital facility
for the field of particle physics worldwide, providing physicists from around
the globe with opportunities to collaborate in a twenty to thirty year program
of exciting science. In this document we provide a comprehensive overview of
LBNE's scientific objectives, its place in the landscape of neutrino physics
worldwide, the technologies it will incorporate and the capabilities it will
possess.Comment: Major update of previous version. This is the reference document for
LBNE science program and current status. Chapters 1, 3, and 9 provide a
comprehensive overview of LBNE's scientific objectives, its place in the
landscape of neutrino physics worldwide, the technologies it will incorporate
and the capabilities it will possess. 288 pages, 116 figure
Cardio-renal cachexia syndromes (CRCS): pathophysiological foundations of a vicious pathological circle
Cardio-renal syndromes (CRS) are defined as disorders of the heart and kidney whereby acute or chronic dysfunction in one organ may induce acute or chronic dysfunction of the other. CRS have been classified into five categories, where types 2 and 4 represent respectively chronic cardio-renal and chronic reno-cardiac syndromes. In these conditions, the chronic disorder of either the heart or kidney has been shown to induce some degree of cachexia. At the same time, cachexia has been proposed as a possible mechanism contributing to the worsening of such pathological organ cross talk. Common pathogenetic mechanisms underlie body wasting in cachectic states of different chronic heart and kidney diseases. In these circumstances, a vicious circle could arise, in which cachexia associated with either heart failure or chronic kidney disease may contribute to further damage of the other organ. In chronic CRS, activation of the immune and neuroendocrine systems contributes to the genesis of cachexia, which in turn can negatively affect the heart and kidney function. In patients with cardiac sustained activation of the immune and neuroendocrine systems and oxidative stress, renal vascular resistance can increase and therefore impair renal perfusion, leading to worsening kidney function. Similarly, in renal cachexia, increased levels of pro-inflammatory cytokines can cause progressive left ventricular systolic dysfunction, myocardial cell death, endothelial dysfunction and increased myocardial fibrosis, with consequent impairment of the chronic reno-cardiac syndrome type 4. Thus, we speculate that the occurrence of different types of chronic CRS could represent a fundamental step in the genesis of cachexia, being renal and cardiac dysfunction closely related to the occurrence of systemic disorders leading to a final common pathway. Therefore, the heart and kidney and cachexia represent a triad causing a vicious circle that increases mortality and morbidity: In such circumstances, we may plausibly talk about cardio-renal cachexia syndrome. Complex interrelations may explain the transition from CRS to cachexia and from cachexia to CRS. Identification of the exact mechanisms occurring in these conditions could potentially help in preventing and treating this deadly combination
The ABC130 barrel module prototyping programme for the ATLAS strip tracker
For the Phase-II Upgrade of the ATLAS Detector, its Inner Detector,
consisting of silicon pixel, silicon strip and transition radiation
sub-detectors, will be replaced with an all new 100 % silicon tracker, composed
of a pixel tracker at inner radii and a strip tracker at outer radii. The
future ATLAS strip tracker will include 11,000 silicon sensor modules in the
central region (barrel) and 7,000 modules in the forward region (end-caps),
which are foreseen to be constructed over a period of 3.5 years. The
construction of each module consists of a series of assembly and quality
control steps, which were engineered to be identical for all production sites.
In order to develop the tooling and procedures for assembly and testing of
these modules, two series of major prototyping programs were conducted: an
early program using readout chips designed using a 250 nm fabrication process
(ABCN-25) and a subsequent program using a follow-up chip set made using 130 nm
processing (ABC130 and HCC130 chips). This second generation of readout chips
was used for an extensive prototyping program that produced around 100
barrel-type modules and contributed significantly to the development of the
final module layout. This paper gives an overview of the components used in
ABC130 barrel modules, their assembly procedure and findings resulting from
their tests.Comment: 82 pages, 66 figure
Synthesis of Disentangled Ultra-High Molecular Weight Polyethylene using Vanadium(V)-Based Catalysts
Two known imido vanadium(V) trichloride complexes, [Cl3V=N-C6H3-2,6-Me-2] (1) and [Cl3V=N-C6H3-2,6-iPr(2)] (2), both of which have escaped testing as ethylene polymerization catalyst precursors, were synthesized and their capacity to polymerize ethylene in the presence of the co-catalyst MAO (methylaluminoxane) (Al:V ratio: 1000:1) at 10 degrees C is reported. The resulting polymers, from both catalysts, have molecular weights exceeding 1-2 million g/mol as suggested by the insolubility at high temperature and rheological measurements. According to the rheological and DSC annealing characterizations the synthesized Ultra-High Molecular Weight PolyEthylene from both 1 and 2 show features of a high degree of disentanglement
Immobilization of [VCl3(N-2,6-Me2C6H3)] Complex on Silica Supports: Synthesis and Catalytic Testing for Ethylene Polymerization
The heterogenization of 2,6-dimethylarylimido-vanadium(V) dichloride via chemical tethering on insoluble silica supports is reported. The effects of the silica particle size, drying conditions, and the reaction time were investigated. The drying conditions of the support were found to be a crucial parameter: drying temperatures over 400 degrees C were needed to achieve successful catalysis. The supported catalytic systems were characterized by Fourier-transform infrared (FT-IR) spectroscopy, transmission electron microscopy-energy-dispersive X-ray (TEM-EDX), and inductively coupled plasma mass spectroscopy (ICP-MS), while the polymers were characterized by FT-IR, differential scanning calorimetry (DSC), and rheology. Ethylene polymerization tests were performed employing the prepared heterogenized catalysts with methylaluminoxane/diethylaluminum chloride as a cocatalyst. The supported catalyst precursor, when activated with diethylaluminum chloride, promotes the synthesis of polyethylene with seemingly controlled particle size in the absence of reactor fouling, suggesting the successful immobilization of the complex over the inert support. The resulting polymer shows features of ultrahigh-molecular-weight polyethylene (UHMWPE). These findings present a proof-of-concept for a new approach toward the heterogenization of arylimido-vanadium complexes
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