118 research outputs found
Degradability of Bosonic Gaussian channels
The notion of weak-degradability of quantum channels is introduced by
generalizing the degradability definition given by Devetak and Shor. Exploiting
the unitary equivalence with beam-splitter/amplifier channels we then prove
that a large class of one-mode Bosonic Gaussian channels are either weakly
degradable or anti-degradable. In the latter case this implies that their
quantum capacity Q is null. In the former case instead, this allows us to
establish the additivity of the coherent information for those maps which admit
unitary representation with single-mode pure environment.Comment: 7 pages, 1 figure, 1 table (minor editing
Lactate dehydrogenase A inhibition by small molecular entities: steps in the right direction
Direct targeting of energy metabolism to defeat cancer is not a recent strategy.
Although quite a few drugs use cellular metabolism for their antitumor effect, no
direct inhibitors of energy metabolism have been approved by the FDA. Currently,
several inhibitors of lactate dehydrogenase A (LDH-A), a key player in glycolysis,
are in development. Earlier, we demonstrated the efficacy of N-hydroxyindole-based
LDH-A inhibitors in different cancer types. In this study we describe the efficacy of
NHI-Glc-2, which is designed to dual target cancer cells, by exploiting a simultaneous
enhanced glucose uptake by overexpressed glucose transporter 1 (GLUT1) and by
inhibition of LDH-A. NHI-Glc-2 inhibits LDH-A enzyme activity, PANC-1 cell growth
and disrupts spheroid integrity, with an overall effect that is more pronounced when
combined with gemcitabine
Teleportation-Induced Correlated Quantum Channels
Quantum teleportation of a n-qubit state performed using as entangled
resource a general bipartite state of 2n qubits instead of n Bell states is
equivalent to a correlated Pauli channel. This provides a new characterization
of such channels in terms of many-body correlation functions of the teleporting
media. Our model is then generalized to the Continuous Variable case. We show
that this new representation provides a relatively simple method for
determining whether a correlated quantum channel is able to reliably convey
quantum messages by studying the entanglement properties of the teleportation
mediating system.Comment: 4 pages, 2 figure
Lung ultrasound in systemic sclerosis: correlation with high-resolution computed tomography, pulmonary function tests and clinical variables of disease
Interstitial lung disease (ILD) is a hallmark of systemic sclerosis (SSc). Although high-resolution computed tomography (HRCT) is the gold standard to diagnose ILD, recently lung ultrasound (LUS) has emerged in SSc patients as a new promising technique for the ILD evaluation, noninvasive and radiation-free. The aim of this study was to evaluate if there is a correlation between LUS, chest HRCT, pulmonary function tests findings and clinical variables of the disease. Thirty-nine patients (33 women and 6 men; mean age 51 ± 15.2 years) underwent clinical examination, HRCT, pulmonary function tests and LUS for detection of B-lines. A positive correlation exists between the number of B-lines and the HRCT score (r = 0.81, p < 0.0001), conversely a negative correlation exists between the number of B-lines and diffusing capacity of the lung for carbon monoxide (DLCO) (r = â0.63, p < 0.0001). The number of B-lines increases along with the progression of the capillaroscopic damage. A statistically significant difference in the number of B-lines was found between patients with and without digital ulcers [42 (3â84) vs 16 (4â55)]. We found that the number of B-lines increased with the progression of both HRCT score and digital vascular damage. LUS may therefore, be a useful tool to determine the best timing for HRCT execution, thus, preventing for many patients a continuous and useless exposure to ionizing radiatio
Qubit channels with small correlations
We introduce a class of quantum channels with correlations acting on pairs of
qubits, where the correlation takes the form of a shift operator onto a
maximally entangled state. We optimise the output purity and show that below a
certain threshold the optimum is achieved by partially entangled states whose
degree of entanglement increases monotonically with the correlation parameter.
Above this threshold, the optimum is achieved by the maximally entangled state
characterizing the shift. Although, a full analysis can only be done for the
2-norm, both numerical and heuristic arguments indicate that this behavior and
the optimal inputs are independent of p>1 when the optimal output purity is
measured using the p-norm.Comment: 11 pages, 4 figures, 2 table
The optimal unitary dilation for bosonic Gaussian channels
A generic quantum channel can be represented in terms of a unitary
interaction between the information-carrying system and a noisy environment.
Here, the minimal number of quantum Gaussian environmental modes required to
provide a unitary dilation of a multi-mode bosonic Gaussian channel is analyzed
both for mixed and pure environment corresponding to the Stinespring
representation. In particular, for the case of pure environment we compute this
quantity and present an explicit unitary dilation for arbitrary bosonic
Gaussian channel. These results considerably simplify the characterization of
these continuous-variable maps and can be applied to address some open issues
concerning the transmission of information encoded in bosonic systems.Comment: 9 page
Qubit quantum channels: A characteristic function approach
A characterization of qubit quantum channels is introduced. In analogy to
what happens in the context of Bosonic channels we exploit the possibility of
representing the states of the system in terms of characteristic function. The
latter are functions of non-commuting variables (Grassmann variables) and are
defined in terms of generalized displacement operators. In this context we
introduce the set of Gaussian channels and show that they share similar
properties with the corresponding Bosonic counterpart.Comment: 10 pages (minor editing
Impact of COVID19 on Maxillofacial Fractures in the Province of L\u27Aquila, Abruzzo, Italy Review of 296 Patients Treated With Statistical Comparison of the Two-Year Pre-COVID19 and COVID19
The aim of this study was to understand the impact of the COVID-19 pandemic on the epidemiology of maxillofacial trauma in a regional trauma center in L\u27Aquila, Abruzzo, Italy, during the first wave of the pandemic and comparted it to an equivalent period from 2015 to 2018. The authorshave retrospectively analyzed personal data, site of trauma, etiology, and mechanism of injury. Statistical analysis has been carried out utilizing IBM SPSS Statistics software (IBM Corp., Armonk, NY) and significance was accepted for P values ofâ0.05) as opposed to the etiology in which the road traffic accidents decreased in favor of domestic accidents and interpersonal assaults (Pâ\u3câ0.05). Our scientific study represents the first epidemiologic study related to the impact of COVID-19 on maxillo-facial trauma in the Province of L\u27Aquila, Abruzzo, Italy. A decrease in the number of Maxillofacial injuries related to road traffic accidents can be demonstrated as the benefit of lockdown, however, a significant increase in the number of physical assaults shows how isolation and restrictions have had a highly negative psychological impact on society
A new approach to characterize qubit channels
We analyze qubit channels by exploiting the possibility of representing
two-level quantum systems in terms of characteristic functions. To do so, we
use functions of non-commuting variables (Grassmann variables), defined in
terms of generalized displacement operators, following an approach which
resemble the one adopted for continuous-variable (Bosonic) systems. It allows
us to introduce the notion of qubit Gaussian channels and to show that they
share similar properties with the corresponding continuous-variable
counterpart. Some examples of qubit channels are investigated using this
approach.Comment: 6 pages, accepted for publication in the special issue of IJQI
"Noise, Information and Complexity at Quantum Scale", eds. S. Mancini and F.
Marchesoni (2008
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