852 research outputs found
Bremsstrahlung neutrinos from electron-electron scattering in a relativistic degenerate electron plasma
We present a calculation of neutrino pair bremsstrahlung due to
electron-electron scattering in a relativistic degenerate plasma of electrons.
Proper treatment of the in-medium photon propagator, i.e., inclusion of Debye
screening of the longitudinal part and Landau damping of the transverse part,
leads to a neutrino emissivity which is several orders of magnitude larger than
when Debye screening is imposed for the tranverse part. Our results show that
this in-medium process can compete with other sources of neutrino radiation and
can, in some cases, even be the dominant neutrino emission mechanism. We also
discuss the natural extension to quark-quark bremsstrahlung in gapped and
ungapped quark matter.Comment: 15 pages, 7 figure
Electron-Neutrino Bremsstrahlung in Electro-Weak Theory
The electron-neutrino bremsstrahlung process has been considered in the
framework of electro-weak theory. The scattering cross section has been
calculated in the center of mass frame and approximated to extreme relativistic
as well as non-relativistic case. The rate of energy-loss via this type of
bremsstrahlung process has been obtained both in non-degenerate and degenerate
region. The effect of this electron-neutrino bremsstrahlung process in
different ranges of temperature and density characterizing the late stages of
stellar evolution has been discussed. It is found from our study that this
bremsstrahlung process is highly important in the non-degenerate region,
although it might have some significant effect in the extreme relativistic
degenerate region.Comment: 18 pages including 4 figures and 1 table; Published in J. Phys
Pharmacological management of COVID-19 patients with ARDS (CARDS): A narrative review
Coronavirus disease 2019 (COVID-19) is highly infectious. It has been highlighted that if not expertly and individually managed with consideration of the vasocentric features, a COVID-19 patient with an acute respiratory distress syndrome (CARDS) may eventually develop multiorgan failure. Unfortunately, there is still no definite drug for CARDS that is capable of reducing either short-term or long-term mortality and no specific treatments for COVID-19 exist right now. In this narrative review, based on a selective literature search in EMBASE, MEDLINE, Scopus, The Cochrane Library, Web of Science, and Google Scholar and ClinicalTrials.gov, we have examined the emerging evidence on the possible treatment of CARDS. Although numerous pharmacologic therapies to improve clinical outcomes in CARDS have been studied also in clinical trials, none have shown efficacy and there is great uncertainty about their effectiveness. There is still no recommendation for the therapeutic use of any specific agent to treat CARDS because no drugs are validated to have significant efficacy in clinical treatment of COVID-19 patients in large-scale trials. However, there exist a number of drugs that may be useful at least in some patients. The real challenge now is to link the right patient to the right treatment
Mutational analysis of BCORL1 in the leukemic transformation of chronic myeloproliferative neoplasms.
BCORL1 mutations do not seem to be commonly associated with leukemic transformation of MPN, further substantiating the different molecular profile compared with denovo leukemias. Although the small number of cases does not allow us to exclude that BCORL1 mutations can be found also in post-MPN AML, their occurrence is, at least, very infrequent and their detection does not appear to deserve clinical relevance
Three-dimensional morphological condylar and mandibular changes in a patient with juvenile idiopathic arthritis: Interdisciplinary treatment
Temporomandibular joint (TMJ) involvement is common but usually delayed in patients with juvenile idiopathic arthritis (JIA). We describe the case of a JIA patient with bilateral TMJ involvement, mandibular retrognathia, bone erosion, and severely restricted mouth opening. The use of cone beam computed tomography and a 3D diagnostic protocol in young patients with JIA provides reliable, accurate and precise quantitative data and images of the condylar structures and their dimensional relationships. Analgesics and conventional disease modifying antirheumatic drugs were ineffective, but interdisciplinary treatment with etanercept and a Herbst functional appliance improved functional TMJ movement and bone resorption
Brain natriuretic peptide: Much more than a biomarker.
Brain natriuretic peptide (BNP) modulates several biological processes by activating the natriuretic peptide receptor A (NPR-A). Atria and ventricles secrete BNP. BNP increases natriuresis, diuresis and vasodilatation, thus resulting in a decreased cardiac workload. BNP and NT-proBNP, which is the biologically inactive N-terminal portion of its pro-hormone, are fast and sensitive biomarkers for diagnosing heart failure. The plasma concentrations of both BNP and NT-proBNP also correlate with left ventricular function in patients with acute exacerbation of COPD, even without history of heart failure. Several studies have been conducted in vitro and in vivo, both in animals and in humans, in order to assess the potential role of the NPR-A activation as a novel therapeutic approach for treating obstructive pulmonary disorders. Unfortunately, these studies have yielded conflicting results. Nevertheless, further recent specific studies, performed in ex vivo models of asthma and COPD, have confirmed the bronchorelaxant effect of BNP and its protective role against bronchial hyperresponsiveness in human airways. These studies have also clarified the intimate mechanism of action of BNP, represented by an autocrine loop elicited by the activation of NPR-A, localized on bronchial epithelium, and the relaxant response of the surrounding ASM, which does not expresses NPR-A. This review explores the teleological activities and paradoxical effects of BNP with regard to chronic obstructive respiratory disorders, and provides an excursus on the main scientific findings that explain why BNP should be considered much more than a biomarker
A cooled telescope for measurements of the Near Infrared Cosmological Background at balloon altitude (TRIP Experiment)
A cooled telescope has been designed and prepared for measurements of both local and cosmological Near InfraRed Backgrounds in the waveband 1–5 mm at balloon altitude (40 km). The detection system consists of a linear array with
32 InSb pixels placed in the focal plane of the telescope, cryogenically cooled and thermally controlled. A short description is given of the main characteristics of the
instrument and of the expected performances. The experiment, repeatedly tested in laboratory, flew in the 1995 summer from Palestine (Texas, USA)
A long-term clinical trial on the efficacy and safety profile of doxofylline in Asthma: The LESDA study.
Doxofylline, an oral methylxanthine with bronchodilator and anti-inflammatory activities, offers a promising alternative to theophylline due to its superior efficacy/safety profile. No long-term studies on the efficacy and safety of doxofylline are currently available in asthma. The aim of the Long-term clinical trial on the Efficacy and Safety profile of Doxofylline in Asthma (LESDA) study was to investigate the safety and efficacy profile of doxofylline administered for one year in asthmatic patients. LESDA was a multicenter, open-label, Phase III, clinical trial in which adult asthmatic patients received the same treatment (oral doxofylline 400 mg t.i.d.) for one year. Efficacy was assessed through periodic pulmonary function tests and by having the subjects keep monthly records of asthma events rates and use of salbutamol as rescue medication. The rate of adverse events (AEs) was recorded during the study. Three-hundred nine patients were screened and allocated in the study. Doxofylline significantly improved the change from baseline in forced expiratory volume in 1 s (FEV1) (+16.90 ± 1.81%, P < 0.001 vs. baseline). Doxofylline also significantly improved the rate of asthma events (events/day: -0.57 ± 0.18, P < 0.05 vs. baseline) and the use of salbutamol as rescue medication (puffs/day: -1.48 ± 0.25, P < 0.01 vs. baseline). The most common AEs were nausea (14.56%), headache (14.24%), insomnia (10.68%), and dyspepsia (10.03%). There were neither serious AEs nor deaths during or shortly after the study. Concluding, doxofylline is effective and well tolerated when administered chronically in asthmatic patients
Weight Loss Improves Cardio-Metabolic and Inflammatory State in Subjects with Metabolic Syndrome
Metabolic syndrome (MetS) is a condition characterized by a constellation of reversible major risk factors for cardiovascular disease (CVD) and type 2 diabetes (T2DM). While it has been widely demonstrated that weight reduction by 5\u201310% decreases CVD and T2DM risk factors, including atherogenic dyslipidemia, on the other hand, its effects on comprehensive serum cytokine profile and endotoxemia are less investigated. Furthermore, the impact of weight loss on these parameters was studied especially in subjects with morbid obesity, often after bariatric surgery; while the studies on the effects of a physiological weight reduction with a balanced hypocaloric diet in overweight and moderately obese subjects showed contradictory results
Accounting for risk of non linear portfolios: a novel Fourier approach
The presence of non linear instruments is responsible for the emergence of
non Gaussian features in the price changes distribution of realistic
portfolios, even for Normally distributed risk factors. This is especially true
for the benchmark Delta Gamma Normal model, which in general exhibits
exponentially damped power law tails. We show how the knowledge of the model
characteristic function leads to Fourier representations for two standard risk
measures, the Value at Risk and the Expected Shortfall, and for their
sensitivities with respect to the model parameters. We detail the numerical
implementation of our formulae and we emphasizes the reliability and efficiency
of our results in comparison with Monte Carlo simulation.Comment: 10 pages, 12 figures. Final version accepted for publication on Eur.
Phys. J.
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