469 research outputs found
Work Extraction and Energy Storage in the Dicke Model
We study work extraction from the Dicke model achieved using simple unitary
cyclic transformations keeping into account both a non optimal unitary
protocol, and the energetic cost of creating the initial state. By analyzing
the role of entanglement, we find that highly entangled states can be
inefficient for energy storage when considering the energetic cost of creating
the state. Such surprising result holds notwithstanding the fact that the
criticality of the model at hand can sensibly improve the extraction of work.
While showing the advantages of using a many-body system for work extraction,
our results demonstrate that entanglement is not necessarily advantageous for
energy storage purposes, when non optimal processes are considered. Our work
shows the importance of better understanding the complex interconnections
between non-equilibrium thermodynamics of quantum systems and correlations
among their subparts.Comment: 5 pages + supplementary informatio
Vibrational assisted conduction in a molecular wire
We present a detailed study of the conduction properties of a molecular wire
where hopping processes between electronic sites are coupled to a vibrational
mode of the molecule. The latter is sandwiched between two electronic leads at
finite temperatures. We show that the electro-mechanical coupling can lead to a
strong enhancement of the lead-to-lead conduction. Moreover, under suitable
driving of the molecular vibrational mode, the device can act as a transistor
passing sharply from enhanced conduction to short-circuit configuration.Comment: 10 pages with appendix and 5 figure
The dental management of patients at risk of medication-related osteonecrosis of the jaw: New paradigm of primary prevention
Medication-related osteonecrosis of the jaw (MRONJ) is a serious adverse reaction of antiresorptive and antiangiogenic agents; it is a potentially painful and debilitating condition that can considerably affect the quality of life of patients. Furthermore, even if its epidemiology and pathogenesis have still not been fully clarified, several risk factors related to MRONJ have been recognized in prevention protocols. Three main risk factors are as follows: (i) the type of ONJ-related medications: antiresorptive (e.g., Bisphosphonates, Denosumab) and antiangiogenic drugs (e.g., Bevacizumab, Sunitinib); (ii) the category of patient at MRONJ risk: cancer versus non-cancer patient; (iii) the typologies and timing of dental treatments (e.g., before, during, or after the drug administration). The aim of this paper is to describe the new paradigm by the Italian Society of Oral Pathology and Medicine (SIPMO) on preventive dental management in patients at risk of MRONJ, prior to and during/after the administration of the aforementioned ONJ-related drugs. In reducing the risk of MRONJ, dentists and oral hygienists are key figures in applying a correct protocol of primary prevention for pre-treatment and in-treatment patients. However, the necessity of a multidisciplinary standardized approach, with a sustained dialogue among specialists involved, should be always adopted in order to improve the efficacy of preventive strategies and to ameliorate the patient\u2019s quality of life
Thermodynamics of trajectories of a quantum harmonic oscillator coupled to baths
We undertake a thorough analysis of the thermodynamics of the trajectories
followed by a quantum harmonic oscillator coupled to dissipative baths by
using a new approach to large-deviation theory inspired by phase-space quantum
optics. As an illustrative example, we study the archetypal case of a harmonic
oscillator coupled to two thermal baths, allowing for a comparison with the
analogous classical result. In the low-temperature limit, we find a significant
quantum suppression in the rate of work exchanged between the system and each
bath. We further show how the presented method is capable of giving analytical
results even for the case of a driven harmonic oscillator. Based on that
result, we analyse the laser cooling of the motion of a trapped ion or
optomechanical system, illustrating how the emission statistics can be
controllably altered by the driving force.Comment: 5 pages, 3 figure
Astrobee Robot Software: A Modern Software System for Space
Astrobee is a new free-flyer robot designed to operate inside the International Space Station (ISS). Astrobee capabilities include markerless navigation, autonomous docking for recharge, perching on handrails to minimize power and modular payloads. Astrobee will operate without crew support, controlled by teleoperation, plan execution, or on-board third parties software. This paper presents the Astrobee Robot Software, a NASA Open-Source project, powering the Astrobee robot. The Astrobee Robot Software relies on a distributed architecture based on the Robot Operating System (ROS). The software runs on three interconnected smart phone class processors. We present the software approach, infrastructure required, and main software components. The Astrobee Robot Software embrace modern software practices while respecting flight constraints. The paper concludes with the lessons learned, including examples usage of the software. Several research teams are already using the Astrobee Robot Software to develop novel projects that will fly on Astrobee
TACC3 mediates the association of MBD2 with histone acetyltransferases and relieves transcriptional repression of methylated promoters
We have recently reported that a novel MBD2 interactor (MBDin) has the capacity to reactivate transcription from MBD2-repressed methylated promoters even in the absence of demethylation events. Here we show that another unrelated protein, TACC3, displays a similar activity on methylated genes. In addition the data reported here provide possible molecular mechanisms for the observed phenomenon. Immunoprecipitation experiments showed that MBD2/TACC3 form a complex in vivo with the histone acetyltransferase pCAF. MBD2 could also associate with HDAC2, a component of MeCP1 repression complex. However, we found that the complexes formed by MBD2 with TACC3/pCAF and with HDAC2 were mutually exclusive. Moreover, HAT enzymatic assays demonstrated that HAT activity associates with MBD2 in vivo and that such association significantly increased when TACC3 was over-expressed. Overall our findings suggest that TACC3 can be recruited by MBD2 on methylated promoters and is able to reactivate transcription possibly by favoring the formation of an HAT-containing MBD2 complex and, thus, switching the repression potential of MBD2 in activation even prior to eventual demethylation
Complications and quality of life in elderly patients with several comorbidities undergoing cutaneous ureterostomy with single stoma or ileal conduit after radical cystectomy
PATZ Attenuates the RNF4-mediated Enhancement of Androgen Receptor-dependent Transcription *
PATZ is a transcriptional repressor affecting the basal activity of different promoters, whereas RNF4 is a transcriptional activator. The association of PATZ with RNF4 switches the activation to repression of selected basal promoters. Because RNF4 interacts also with the androgen receptor (AR) functioning as a coactivator and, in turn, RNF4 associates with PATZ, we investigated whether PATZ functions as an AR coregulator. We demonstrate that PATZ does not influence directly the AR response but acts as an AR corepressor in the presence of RNF4. Such repression is not dependent on histone deacetylases. A mutant RNF4 that does not bind PATZ but enhances AR-dependent transcription is not influenced by PATZ, demonstrating that the repression by PATZ occurs only upon binding to RNF4. We also demonstrate that RNF4, AR, and PATZ belong to the same complex in vivo also in the presence of androgen, suggesting that repression is not mediated by the displacement of RNF4 from AR. Finally, we show that the repression of endogenous PATZ expression by antisense expression plasmids in LNCaP cells results in a stronger androgen response. Our findings demonstrate that PATZ is a novel AR coregulator that acts by modulating the effect of a coactivator. This could represent a novel and more general mechanism to finely tune the androgen response
Soft and hard wall in a stochastic reaction diffusion equation
We consider a stochastically perturbed reaction diffusion equation in a
bounded interval, with boundary conditions imposing the two stable phases at
the endpoints. We investigate the asymptotic behavior of the front separating
the two stable phases, as the intensity of the noise vanishes and the size of
the interval diverges. In particular, we prove that, in a suitable scaling
limit, the front evolves according to a one-dimensional diffusion process with
a non-linear drift accounting for a "soft" repulsion from the boundary. We
finally show how a "hard" repulsion can be obtained by an extra diffusive
scaling.Comment: 33 page
A review of global health technology assessments of non-VKA oral anticoagulants in non-valvular atrial fibrillation.
Abstract Background This review assessed global health technology assessment (HTA) reports and recommendations of non-vitamin K oral anticoagulants (NOACs) in non-valvular atrial fibrillation (NVAF). Methods NHTA agency websites were searched for HTA reports evaluating NOACs versus NOACs or vitamin K antagonists. HTA methods and information on patient involvement/access were collected and empirically analyzed. Results The review identified 38 unique HTA reports published between 2012 and 2017 in 16 countries including 11 in Europe. NOACs that were cost-effective per local willingness-to-pay (WTP) thresholds were positively recommended for the treatment of NVAF. WTP thresholds ranged from €20,000 to 69,000. Apixaban was recommended in 10/12 (83%) countries, dabigatran in 9/13 (69%) countries, and rivaroxaban in 10/13 (76%) over warfarin. Edoxaban was recommended in 5/7 (71%) countries. Economic evaluations and recommendations comparing NOACs were sparse (two or three countries per NOAC) and generally favored apixaban and edoxaban, followed by dabigatran. Eleven HTA reports from four countries considered the patient voice (Canada [n = 3], Scotland [n = 3], England [n = 4], Brazil [n = 1]); however, only 2/11 (18%) developed recommendations based on this. Among the reports with a positive recommendation, 26/30 (87%) featured a decision that aligned with the approved regulatory label. Conclusions Most agencies recommended NOACs over warfarin for patients with NVAF. Few countries made statements recommending one NOAC over another. Given different WTP thresholds, a drug that is cost-effective in one market may not be in another. Therefore, the various NOAC recommendations from HTA agencies cannot be generalized across different countries
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