181 research outputs found
The three-body recombination of a condensed Bose gas near a Feshbach resonance
In this paper, we study the three-body recombination rate of a homogeneous
dilute Bose gas with a Feshbach resonance at zero temperature. The ground state
and excitations of this system are obtained. The three-body recombination in
the ground state is due to the break-up of an atom pair in the quantum
depletion and the formation of a molecule by an atom from the broken pair and
an atom from the condensate. The rate of this process is in good agreement with
the experiment on Na in a wide range of magnetic fields.Comment: 10 pages, 2 figures, to be published in Phys. Rev.
Climate change-induced disasters and cultural heritage: Optimizing management strategies in Central Europe
Due to climate change, it is foreseen that the frequency and magnitude of extreme climate events such as heavy precipitation, flooding and drought will increase throughout Europe. In recent times, numerous areas suffered from disasters that produced significant damage to cultural heritage. Although different risk management strategies are currently enforced in Central Europe, there still exist many challenges that undermine their effectiveness. This study reviews the necessary points to be addressed for strengthening existing management strategies within the region and the characteristics of potential resilience building measures. It presents feasible and tailored ICT solutions (e.g. a web GIS platform) and decision support tools (e.g. a manual for cultural heritage resilience and a handbook on transnational rescue procedures) for the protection of cultural heritage against floods, heavy rain and fire. These tools result from the Interreg Central Europe project ProteCHt2save, concentrating on risk assessment and sustainable protection of cultural heritage in changing environments. The proposed measures are tested at pilot sites and successfully integrated in local risk management plans. Future work is also proposed for further implementation of the results
Applications of three-dimensional carbon nanotube
In this paper, we show that it is possible to synthesize carbon-based three-dimensional networks by adding sulfur, as growth
enhancer, during the synthesis process. The obtained material is self-supporting and consists of curved and interconnected carbon
nanotubes and to lesser extent of carbon fibers. Studies on the microstructure indicate that the assembly presents a marked variability
in the tube external diameter and in the inner structure. We study the relationship between the observed microscopic properties
and some potential applications. In particular, we show that the porous nature of the network is directly responsible for the
hydrophobic and the lipophilic behavior. Moreover, we used a cut piece of the produced carbon material as working electrode in a
standard electrochemical cell and, thus, demonstrating the capability of the system to respond to incident light in the visible and
near-ultraviolet region and to generate a photocurrent
Usefulness of Low-Dose Statin Plus Ezetimibe and/or Nutraceuticals in Patients With Coronary Artery Disease Intolerant to High-Dose Statin Treatment.
High-dose statin (HDS) therapy is recommended to reduce low-density lipoprotein cholesterol (LDL-C); however, some patients are unable to tolerate the associated side effects. Nutraceuticals have shown efficacy in lowering LDL-C. The aim of this study was to evaluate whether the combination of low-dose statin (LDS) plus ezetimibe (EZE) or LDS plus nutraceutical (Armolipid Plus [ALP] containing red yeast rice, policosanol, and berberine) can lead to a higher proportion of high-risk patients achieving target LDL-C. A secondary objective was to assess the efficacy of triple combination LDS + EZE + ALP in resistant patients (LDL-C >70 mg/dl). A randomized, prospective, parallel-group, single-blind study was conducted in patients with coronary artery disease (n = 100) who had undergone percutaneous coronary intervention in the preceding 12 months, were HDS-intolerant, and were not at LDL-C target (<70 mg/dl) with LDS alone. Patients received either LDS + EZE or LDS + ALP. Of the 100 patients, 33 patients (66%) treated with LDS + EZE and 31 patients (62%) treated with LDS + ALP achieved target LDL-C after 3 months, which was maintained at 6 months. Patients who did not achieve the therapeutic goal received a triple combination of LDS + EZE + ALP for a further 3 months. At 6 months, 28 of 36 patients (78%) achieved LDL-C target. Overall, 92% of patients enrolled in this study were at target LDL-C at 6 months. No patients in any group experienced major side effects. In conclusion, in HDS-intolerant coronary artery disease patients, the combination of LDS plus EZE and/or ALP represents a valuable therapeutic option allowing most patients to reach target LDL-C within 3 to 6 months
Multi-GeV Electron Spectrometer
The advance in laser plasma acceleration techniques pushes the regime of the
resulting accelerated particles to higher energies and intensities. In
particular the upcoming experiments with the FLAME laser at LNF will enter the
GeV regime with almost 1pC of electrons. From the current status of
understanding of the acceleration mechanism, relatively large angular and
energy spreads are expected. There is therefore the need to develop a device
capable to measure the energy of electrons over three orders of magnitude (few
MeV to few GeV) under still unknown angular divergences. Within the PlasmonX
experiment at LNF a spectrometer is being constructed to perform these
measurements. It is made of an electro-magnet and a screen made of
scintillating fibers for the measurement of the trajectories of the particles.
The large range of operation, the huge number of particles and the need to
focus the divergence present unprecedented challenges in the design and
construction of such a device. We will present the design considerations for
this spectrometer and the first results from a prototype.Comment: 7 pages, 6 figures, submitted to NIM
Personalized bone reconstruction and regeneration in the treatment of craniosynostosis
Craniosynostosis (CS) is the second most prevalent craniofacial congenital malformation due to the premature fusion of skull sutures. CS care requires surgical treatment of variable complexity, aimed at resolving functional and cosmetic defects resulting from the skull growth constrain. Despite significant innovation in the management of CS, morbidity and mortality still exist. Residual cranial defects represent a potential complication and needdedicated management to drive a targeted bone regeneration while modulating suture ossification. To this aim, existing techniques are rapidly evolving and include the implementation of novel biomaterials, 3D printing and additive manufacturing techniques, and advanced therapies based on tissue engineering. This review aims at providing an exhaustive and up\u2010to\u2010date overview of the strategies in use to correct these congenital defects, focusing on the technological advances in the fields of biomaterials and tissue engineering implemented in pediatric surgical skull reconstruction, i.e., biodegradable bone fixation systems, biomimetic scaffolds, drug delivery systems, and cell\u2010based approaches
Citric acid aerospace stainless steel passivation: a green approach
Passivation is a common treatment to maximize the corrosion resistance of stainless steel. Nitric acid is generally used and involves several ecological problems, citric acid could be a promising and environmentally
friendly alternative to nitric acid. In this work citric acid has been extracted from lemon waste using and eco-
friendly procedure. The stainless steel samples have been treated in both nitric and citric acid (commercial
and extracted) and corrosion test have been performed. The results show how citric acid can be used as
substitute of nitric acid in passivation treatment
Perifosine as a Potential Novel Anti-Cancer Agent Inhibits EGFR/MET-AKT Axis in Malignant Pleural Mesothelioma
PI3K/AKT signalling pathway is aberrantly active and plays a critical role for cell cycle progression of human malignant pleural mesothelioma (MMe) cells. AKT is one of the important cellular targets of perifosine, a novel bio-available alkylphospholipid that has displayed significant anti-proliferative activity in vitro and in vivo in several human tumour model systems and is currently being tested in clinical trials.We tested Perifosine activity on human mesothelial cells and different mesothelioma cell lines, in order to provide evidence of its efficacy as single agent and combined therapy.We demonstrate here that perifosine, currently being evaluated as an anti-cancer agent in phase 1 and 2 clinical trials, caused a dose-dependent reduction of AKT activation, at concentrations causing MMe cell growth arrest. In this study we firstly describe that MMe cells express aside from AKT1 also AKT3 and that either the myristoylated, constitutively active, forms of the two proteins, abrogated perifosine-mediated cell growth inhibition. Moreover, we describe here a novel mechanism of perifosine that interferes, upstream of AKT, affecting EGFR and MET phosphorylation. Finally, we demonstrate a significant increase in cell toxicity when MMe cells were treated with perifosine in combination with cisplatin.This study provides a novel mechanism of action of perifosine, directly inhibiting EGFR/MET-AKT1/3 axis, providing a rationale for a novel translational approach to the treatment of MMe
Technical feasibility of microwave absorbers for straylight mitigation in the LiteBIRD MHFT telescopes
The LiteBIRD mission is dedicated to the search for primordial B modes in the Cosmic Microwave Background (CMB) polarization. To achieve unprecedented sensitivity and accuracy in this measurement, the control of instrument systematics is paramount. In this context, we describe the development of microwave absorbers needed to mitigate the straylight within the telescope tubes of the LiteBIRD Mid- and High-Frequency Telescopes (MHFT). A baseline solution has been designed and validated using HFSS simulations, consistently demonstrating sub-percent level specular reflectance across the entire 90-448 GHz band of the MHFT under a broad variety of incidence conditions, representative of the actual optical environment predicted for the two telescopes. Leveraging consolidated technologies, a prototype has been manufactured and characterized in laboratory, demonstrating a promising reflectance mitigation despite the deviation from the nominal geometry. Ongoing parallel efforts involve a comprehensive investigation (both through simulations and laboratory measurements) of the requirements to be finalized in order to define the practical implementation of the baseline design. This activity will ultimately ensure the alignment with allocated thermo-mechanical requirements along with the compliance with the desired electromagnetic performance. The presented studies not only solidify the feasibility of the straylight mitigation approach, but also inform the finalization of the optical tube design, in view of the conclusion of the CNES Phase A study of LiteBIRD
High angular resolution Sunyaev Zel'dovich observations: the case of MISTRAL
The MIllimeter Sardinia radio Telescope Receiver based on Array of Lumped
elements kids, MISTRAL, is a millimetric () multipixel camera
being built for the Sardinia Radio Telescope. It is going to be a facility
instrument and will sample the sky with 12 arcsec angular resolution, 4 arcmin
field of view, through 408 Kinetic Inductance Detectors (KIDs). The
construction and the beginning of commissioning is planned to be in 2022.
MISTRAL will allow the scientific community to propose a wide variety of
scientific cases including protoplanetary discs study, star forming regions,
galaxies radial profiles, and high angular resolution measurements of the
Sunyaev Zel'dovich (SZ) effect with the investigation of the morphology of
galaxy cluster and the search for the Cosmic Web.Comment: 18 pages, 6 figure, accepted for pubblication in the International
Journal of Modern Physics
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