1,224 research outputs found
Measurement of the top quark mass at D0
The most recent measurements of the mass of the quark top at D0 are reviewed. The analysis methods include the direct measurement by Matrix Element and Weighting method and the indirect measurement from t{bar t} production cross section. They have been applied on different experimental signatures, all including at least one electron or muon. Measurements include from 1 to 3.6 fb{sup -1} of D0 data. The most recent combination of mass measurements from D0 and from CDF are also quoted
Tissue Factor/Factor FVII Complex Inhibitors in Cardiovascular Disease. Are Things Going Well?
Blood coagulation is a complex biological mechanism aimed to avoid bleeding in which a highly regulated and coordinated interplay of specific proteins and cellular components respond quickly to a vascular injury. However, when this mechanisms occurs in the coronary circulation, it has not a “protective” effect, but rather, it plays a pivotal role in determining acute coronary syndromes. Coagulation recognizes Tissue Factor (TF), the main physiological initiator of the extrinsic coagulation pathway, as its starter
An easy access to furan fused polyheterocyclic systems
Nitrostilbenes characterized by two different or differently substituted aryl moieties can be obtained from the initial ring-opening of 3-nitrobenzo[b]thiophene with amines. Such versatile building blocks couple the well-recognized double electrophilic reactivity of the nitrovinyl moiety (addition to the double bond, followed by, e.g., intramolecular replacement of the nitro group) with the possibility to exploit a conjugated system of double bonds within an electrocyclization process. Herein, nitrostilbenes are reacted with different aromatic enols provided by a double (carbon and oxygen) nucleophilicity, leading to novel, interesting naphthodihydrofurans. From these, as a viable application, aromatization and electrocyclization lead in turn to valuable polycondensed, fully aromatic O-heterocycles. © 2022 by the authors. Licensee MDPI, Basel, Switzerland
Surgery or Locoregional Approaches for Hepatic Oligometastatic Pancreatic Cancer: Myth, Hope, or Reality?
Despite extensive research, pancreatic ductal adenocarcinoma (PDAC) remains a difficult-to-treat cancer associated with poor survival. Due to the known aggressive disease biology, palliative chemotherapy is the only routinely recommended treatment in the metastatic setting in patients with adequate performance status. However, in a subset of patients with oligometastatic disease, multimodality treatment with surgery and/or locoregional approaches may provide long-term disease control and prolong survival. In fact, in highly selected cases, median overall survival has been reported to extend to 56 months in patients treated with surgery. In particular, liver and extraregional nodal resections may provide long-term tumor control with acceptable morbidity. Current guidelines do not recommend surgery for patients with metastatic PDAC and, in the case of PDAC with oligometastases, there are no published randomized controlled trials regarding locoregional or surgical approaches. Here we review the literature on surgical and locoregional approaches including radiofrequency ablation, irreversible electroporation, and stereotactic body radiation, and focus on patients with hepatic oligometastatic pancreatic cancer. We provide a summary regarding survival outcomes, morbidity and mortality and discuss selection criteria that may be useful to predict the best outcomes for such strategies
Implicit Neural Representation as a Differentiable Surrogate for Photon Propagation in a Monolithic Neutrino Detector
Optical photons are used as signal in a wide variety of particle detectors.
Modern neutrino experiments employ hundreds to tens of thousands of photon
detectors to observe signal from millions to billions of scintillation photons
produced from energy deposition of charged particles. These neutrino detectors
are typically large, containing kilotons of target volume, with different
optical properties. Modeling individual photon propagation in form of look-up
table requires huge computational resources. As the size of a table increases
with detector volume for a fixed resolution, this method scales poorly for
future larger detectors. Alternative approaches such as fitting a polynomial to
the model could address the memory issue, but results in poorer performance.
Both look-up table and fitting approaches are prone to discrepancies between
the detector simulation and the data collected. We propose a new approach using
SIREN, an implicit neural representation with periodic activation functions, to
model the look-up table as a 3D scene and reproduces the acceptance map with
high accuracy. The number of parameters in our SIREN model is orders of
magnitude smaller than the number of voxels in the look-up table. As it models
an underlying functional shape, SIREN is scalable to a larger detector.
Furthermore, SIREN can successfully learn the spatial gradients of the photon
library, providing additional information for downstream applications. Finally,
as SIREN is a neural network representation, it is differentiable with respect
to its parameters, and therefore tunable via gradient descent. We demonstrate
the potential of optimizing SIREN directly on real data, which mitigates the
concern of data vs. simulation discrepancies. We further present an application
for data reconstruction where SIREN is used to form a likelihood function for
photon statistics
Systematic analysis of human kinase genes: a large number of genes and alternative splicing events result in functional and structural diversity
BACKGROUND: Protein kinases are a well defined family of proteins, characterized by the presence of a common kinase catalytic domain and playing a significant role in many important cellular processes, such as proliferation, maintenance of cell shape, apoptosys. In many members of the family, additional non-kinase domains contribute further specialization, resulting in subcellular localization, protein binding and regulation of activity, among others. About 500 genes encode members of the kinase family in the human genome, and although many of them represent well known genes, a larger number of genes code for proteins of more recent identification, or for unknown proteins identified as kinase only after computational studies. RESULTS: A systematic in silico study performed on the human genome, led to the identification of 5 genes, on chromosome 1, 11, 13, 15 and 16 respectively, and 1 pseudogene on chromosome X; some of these genes are reported as kinases from NCBI but are absent in other databases, such as KinBase. Comparative analysis of 483 gene regions and subsequent computational analysis, aimed at identifying unannotated exons, indicates that a large number of kinase may code for alternately spliced forms or be incorrectly annotated. An InterProScan automated analysis was perfomed to study domain distribution and combination in the various families. At the same time, other structural features were also added to the annotation process, including the putative presence of transmembrane alpha helices, and the cystein propensity to participate into a disulfide bridge. CONCLUSION: The predicted human kinome was extended by identifiying both additional genes and potential splice variants, resulting in a varied panorama where functionality may be searched at the gene and protein level. Structural analysis of kinase proteins domains as defined in multiple sources together with transmembrane alpha helices and signal peptide prediction provides hints to function assignment. The results of the human kinome analysis are collected in the KinWeb database, available for browsing and searching over the internet, where all results from the comparative analysis and the gene structure annotation are made available, alongside the domain information. Kinases may be searched by domain combinations and the relative genes may be viewed in a graphic browser at various level of magnification up to gene organization on the full chromosome set
Obesity and ischemic heart disease. Is there a link between wellness’ diseases?
Obesity, the most common nutritional disorder in Western countries, is usually associated to cardiovascular diseases. However, the precise molecular pathways underlying this close association remain poorly understood. Nowadays, the adipose tissue is considered as an endocrine organ able to produce substances called adipo(cyto)kines that have different effects on lipid metabolism, closely involved in metabolic syndrome, and cardiovascular risk. The increased cardiovascular risk can be related also to peculiar dysfunction in the endocrine activity of adipose tissue observed in obesity responsible of vascular impairment (including endothelial dysfunction), prothrombotic tendency, and low-grade chronic inflammation. The present review aims at providing an up-dated overview on the adipocytederived molecules potentially involved in cardiovascular pathophysiology
BriXs ultra high fluxinverse compton source based on modified push-pull energy recovery linacs
We present a conceptual design for a compact X-ray Source BriXS (Bright and compact
X-ray Source). BriXS, the first stage of the Marix project, is an Inverse Compton Source (ICS) of
X-ray based on superconducting cavities technology for the electron beam with energy recirculation
and on a laser system in Fabry-Pérot cavity at a repetition rate of 100 MHz, producing 20–180 keV
monochromatic X-Rays devoted mainly to medical applications. An energy recovery scheme based on
a modified folded push-pull CW-SC twin Energy Recovery Linac (ERL) ensemble allows us to sustain
an MW-class beam power with almost one hundred kW active power dissipation/consumption
Optimisation Study of the Fabry-Pérot Optical Cavity for the MARIX/BRIXS Compton X-Ray Source
We present the study of the optimization of the optical cavity parameters, in order to maximise the flux of scattered photons in the Compton scattering process. In the optimisation, we compensate the losses of the photon number due to the elliptical shape of the laser pulse in optical cavity with a high focusing electron beam
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