Experimental Property Reconstruction in a Photonic Quantum Extreme Learning Machine.

Recent developments have led to the possibility of embedding machine learning tools into experimental platforms to address key problems, including the characterization of the properties of quantum states. Leveraging on this, we implement a quantum extreme learning machine in a photonic platform to achieve resource-efficient and accurate characterization of the polarization state of a photon. The underlying reservoir dynamics through which such input state evolves is implemented using the coined quantum walk of high-dimensional photonic orbital angular momentum and performing projective measurements over a fixed basis. We demonstrate how the reconstruction of an unknown polarization state does not need a careful characterization of the measurement apparatus and is robust to experimental imperfections, thus representing a promising route for resource-economic state characterization.

Erratum: Quantifying Qubit Magic Resource with Gottesman-Kitaev-Preskill Encoding [Phys. Rev. Lett. 128, 210502 (2022)].

This corrects the article DOI: 10.1103/PhysRevLett.128.210502.

Quantifying Qubit Magic Resource with Gottesman-Kitaev-Preskill Encoding.

Quantum resource theories are a powerful framework for characterizing and quantifying relevant quantum phenomena and identifying processes that optimize their use for different tasks. Here, we define a resource measure for magic, the sought-after property in most fault-tolerant quantum computers. In contrast to previous literature, our formulation is based on bosonic codes, well-studied tools in continuous-variable quantum computation. Particularly, we use the Gottesman-Kitaev-Preskill code to represent multiqubit states and consider the resource theory for the Wigner negativity. Our techniques are useful in finding resource lower bounds for different applications as state conversion and gate synthesis. The analytical expression of our magic measure allows us to extend current analysis limited to small dimensions, easily addressing systems of up to 12 qubits.

Universal Gate Set for Continuous-Variable Quantum Computation with Microwave Circuits.

We provide an explicit construction of a universal gate set for continuous-variable quantum computation with microwave circuits. Such a universal set has been first proposed in quantum-optical setups, but its experimental implementation has remained elusive in that domain due to the difficulties in engineering strong nonlinearities. Here, we show that a realistic three-wave mixing microwave architecture based on the superconducting nonlinear asymmetric inductive element [Frattini et al., Appl. Phys. Lett. 110, 222603 (2017)APPLAB0003-695110.1063/1.4984142] allows us to overcome this difficulty. As an application, we show that this architecture allows for the generation of a cubic phase state with an experimentally feasible procedure. This work highlights a practical advantage of microwave circuits with respect to optical systems for the purpose of engineering non-Gaussian states and opens the quest for continuous-variable algorithms based on few repetitions of elementary gates from the continuous-variable universal set.

Machine Learning-Based Classification of Vector Vortex Beams.

Structured light is attracting significant attention for its diverse applications in both classical and quantum optics. The so-called vector vortex beams display peculiar properties in both contexts due to the nontrivial correlations between optical polarization and orbital angular momentum. Here we demonstrate a new, flexible experimental approach to the classification of vortex vector beams. We first describe a platform for generating arbitrary complex vector vortex beams inspired to photonic quantum walks. We then exploit recent machine learning methods-namely, convolutional neural networks and principal component analysis-to recognize and classify specific polarization patterns. Our study demonstrates the significant advantages resulting from the use of machine learning-based protocols for the construction and characterization of high-dimensional resources for quantum protocols.

Experimental Engineering of Arbitrary Qudit States with Discrete-Time Quantum Walks.

The capability to generate and manipulate quantum states in high-dimensional Hilbert spaces is a crucial step for the development of quantum technologies, from quantum communication to quantum computation. One-dimensional quantum walk dynamics represents a valid tool in the task of engineering arbitrary quantum states. Here we affirm such potential in a linear-optics platform that realizes discrete-time quantum walks in the orbital angular momentum degree of freedom of photons. Different classes of relevant qudit states in a six-dimensional space are prepared and measured, confirming the feasibility of the protocol. Our results represent a further investigation of quantum walk dynamics in photonics platforms, paving the way for the use of such a quantum state-engineering toolbox for a large range of applications.

Coherently opening a high-Q cavity.

We propose a general framework to effectively "open" a high-Q resonator, that is, to release the quantum state initially prepared in it in the form of a traveling electromagnetic wave. This is achieved by employing a mediating mode that scatters coherently the radiation from the resonator into a one-dimensional continuum of modes such as a waveguide. The same mechanism may be used to "feed" a desired quantum field to an initially empty cavity. Switching between an open and "closed" resonator may then be obtained by controlling either the detuning of the scatterer or the amount of time it spends in the resonator. First, we introduce the model in its general form, identifying (i) the traveling mode that optimally retains the full quantum information of the resonator field and (ii) a suitable figure of merit that we study analytically in terms of the system parameters. Then, we discuss two feasible implementations based on ensembles of two-level atoms interacting with cavity fields. In addition, we discuss how to integrate traditional cavity QED in our proposal using three-level atoms.

Mechanical thrombectomy using neurovascular catheter from radial artery during acute myocardial infarction: A case report.

Coronary occlusion due to large thrombus is frequently encountered during ST-elevation myocardial infarction (STEMI). Despite guidelines discourage this practice, often thrombus aspiration is necessary to reduce thrombotic burden and to prevent embolization. We report a case of mechanical thrombectomy with a Neurovascular Catheter from radial artery during inferior STEMI.

Promising High-Tech Devices in Dry Eye Disease Diagnosis.

BACKGROUND: Dry eye disease (DED) is a common and debilitating condition that affects millions of people worldwide. Despite its prevalence, the diagnosis and management of DED can be challenging, as the condition is multifactorial and symptoms can be nonspecific. In recent years, there have been significant advancements in diagnostic technology for DED, including the development of several new devices. METHODS: A literature review of articles on the dry eye syndrome and innovative diagnostic devices was carried out to provide an overview of some of the current high-tech diagnostic tools for DED, specifically focusing on the TearLab Osmolarity System, DEvice Hygrometer, IDRA, Tearcheck, Keratograph 5M, Cornea Dome Lens Imaging System, I-PEN Osmolarity System, LipiView II interferometer, LacryDiag Ocular Surface Analyzer, Tearscope-Plus, and Cobra HD Camera. CONCLUSIONS: Despite the fact that consistent use of these tools in clinical settings could facilitate diagnosis, no diagnostic device can replace the TFOS algorithm.

Nonclassicality criteria from phase-space representations and information-theoretical constraints are maximally inequivalent.

We consider two celebrated criteria for defining the nonclassicality of bipartite bosonic quantum systems, the first stemming from information theoretic concepts and the second from physical constraints on the quantum phase space. Consequently, two sets of allegedly classical states are singled out: (i) the set C composed of the so-called classical-classical (CC) states-separable states that are locally distinguishable and do not possess quantum discord; (ii) the set P of states endowed with a positive P representation (P-classical states)-mixtures of Glauber coherent states that, e.g., fail to show negativity of their Wigner function. By showing that C and P are almost disjoint, we prove that the two defining criteria are maximally inequivalent. Thus, the notions of classicality that they put forward are radically different. In particular, generic CC states show quantumness in their P representation, and vice versa, almost all P-classical states have positive quantum discord and, hence, are not CC. This inequivalence is further elucidated considering different applications of P-classical and CC states. Our results suggest that there are other quantum correlations in nature than those revealed by entanglement and quantum discord.

Gapped two-body Hamiltonian for continuous-variable quantum computation.

We introduce a family of Hamiltonian systems for measurement-based quantum computation with continuous variables. The Hamiltonians (i) are quadratic, and therefore two body, (ii) are of short range, (iii) are frustration-free, and (iv) possess a constant energy gap proportional to the squared inverse of the squeezing. Their ground states are the celebrated Gaussian graph states, which are universal resources for quantum computation in the limit of infinite squeezing. These Hamiltonians constitute the basic ingredient for the adiabatic preparation of graph states and thus open new venues for the physical realization of continuous-variable quantum computing beyond the standard optical approaches. We characterize the correlations in these systems at thermal equilibrium. In particular, we prove that the correlations across any multipartition are contained exactly in its boundary, automatically yielding a correlation area law.

Vitamin D status and mortality risk in patients with chronic kidney disease.

Several studies have shown that mineral metabolism disorders play a major role in determining a higher mortality rate for end-stage renal disease patients. Vitamin D deficiency is associated with cardiovascular events in hemodialysis patients. Recently, an association between vitamin D insufficiency and cardiovascular or renal events has been found, in patients with chronic renal failure who have not started renal replacement therapy yet. To further investigate this issue, we evaluated the relationship between blood levels of 25-hydroxyvitamin D (25-OH D; > or ≤30 ng/mL) and mortality or dialysis dependence in 104 incident consecutive patients with chronic kidney disease stages 3-5, over a period of 17 months, with a follow-up of 2 years in a cross-sectional analysis. The correlation between different levels of vitamin D and the risk of events has been estimated by using a probit model. Explanatory variables employed concerned age, sex, blood pressure, BMI, and number of co-morbid factors. The average 25-OH D concentration was of 30.13 ng/mL. During follow-up (>16 months), each patient experienced an average of 1.28 events. Vitamin D has been shown to reduce the probability of cardiovascular or renal events. Vitamin D intake for more than 12 months can reduce the probability of such events by 11.42%. Each co-morbid factor, instead, raises the probability of events by 29%. Lower probabilities of experiencing an adverse cardiovascular event might depend on higher levels of vitamin D. The influence of 25-OH D on survival in chronic kidney disease patients may be related to unrecognized factors that need to be further explored.

Apixaban and eftrenonacog alfa treatment in a patient with moderate hemophilia B and cardiovascular disease.

In developed countries, the life expectancy of patients with hemophilia (PwH) is now close to that of the unaffected male population. This means that these patients are at risk of developing age-related comorbidities, including cardiovascular disease. Managing cardiovascular disease in PwH patients can be particularly challenging, due to their high bleeding risk. To our knowledge, this is the first report of a male patient with moderate hemophilia B and hypertensive ischemic heart disease complicated by arrhythmia due to nonvalvular atrial fibrillation, who was treated with apixaban and left atrial appendage closure while receiving concomitant anti-hemorrhagic prophylaxis with eftrenonacog alfa.

Three-qubit refrigerator with two-body interactions.

We propose a three-qubit setup for the implementation of a variety of quantum thermal machines where all heat fluxes and work production can be controlled. An important configuration that can be designed is that of an absorption refrigerator, extracting heat from the coldest reservoir without the need of external work supply. Remarkably, we achieve this regime by using only two-body interactions instead of the widely employed three-body interactions. This configuration could be more easily realized in current experimental setups. We model the open-system dynamics with both a global and a local master equation thermodynamic-consistent approach. Finally, we show how this model can be employed as a heat valve, in which by varying the local field of one of the two qubits allows one to control and amplify the heat current between the other qubits.

Robust quantum state engineering through coherent localization in biased-coin quantum walks.

We address the performance of a coin-biased quantum walk as a generator for non-classical position states of the walker. We exploit a phenomenon of coherent localization in the position space - resulting from the choice of small values of the coin parameter and assisted by post-selection - to engineer large-size coherent superpositions of position states of the walker. The protocol that we design appears to be remarkably robust against both the actual value taken by the coin parameter and strong dephasing-like noise acting on the spatial degree of freedom. We finally illustrate a possible linear-optics implementation of our proposal, suitable for both bulk and integrated-optics platforms.

The present and future of drug-eluting stents.

The only widely accepted way to reduce restenosis rate after percutaneous balloon angioplasty has been the use of coronary bare metal stents, and the last decade has witnessed a prompt and widespread adoption of bare metal stents that has revolutionized the field of interventional cardiology. The new millennium has seen the recent development of drug-eluting stents (DES), allowing controlled release of a drug directly to the injured artery, which seem to have prevented by large the problem of in-stent restenosis. The goal of this review was to summarize recent laboratory and clinical investigations concerning the effects of DES in various settings relevant to coronary heart disease. In the experimental setting, we examine the intracellular signaling and the role of smooth muscle cells after vascular injury. We also discuss recent observations from our laboratory showing the effects of coating per se on cell apoptosis and proliferation. In the clinical setting, the effects of DES in patients with stable or unstable angina pectoris is examined in detail for the relevant implications both in the treatment and prognosis. The results of a meta-analysis on the effects that have been overlooked in individual studies are reported which show a striking reduction in bypass surgery after DES implantation. Finally, we discuss the potential role of new materials and technologies (i.e., nanotechnology) that will improve DES performance allowing other future clinical applications in patients with ST-elevation myocardial infarction, vulnerable plaques, insulin-dependent diabetes mellitus, etc.

Transient cerebral ischemia in an elderly patient with patent foramen ovale and atrial septal aneurysm.

Cerebrovascular disease is one of the most common causes of cerebrovascular morbidity and mortality in developed countries; up to 40% of acute ischemic strokes in young adults are cryptogenic in nature - that is, no cause is determined. However, in more than half of these patients, patent foramen ovale (PFO) is seen along with an increased incidence of atrial septal aneurysm (ASA). The following is a report of an interesting case: a 68-year-old man with ASA and transient cerebral ischemia. Transesophageal echocardiography (TEE) showed the presence of ASA; a test with microbubbles derived from a mixture of air and saline or colloids pointed out a shunt on the foramen ovale following Valsalva's maneuver. The patient underwent percutaneous transcatheter closure of the interatrial communication by an interventional cardiologist. TEE and transcranial Doppler or TEE with the microbubbles test are the recommended methods for detecting and quantifying intracardiac shunts, both at rest and following Valsalva's maneuver. In patients following the first event of transient ischemic attack, and without clinical and anatomical risk factors (such as the presence of ASA, PFO, and basal shunt), pharmacological treatment with antiplatelets or anticoagulants is closely recommended. On the contrary, in patients following the first event of transient ischemic attack, or a recurrent event during antiplatelet treatment, the percutaneous closure of PFO is recommended.

[Mechanism of troponin and CK-MB release after percutaneous coronary interventions]. / Meccanismo del rilascio delle troponine e del CK-MB durante procedure interventistiche percutanee.

Cardiac troponins are highly sensitive and specific markers of early detection of myocardial injury. The incidence of cardiac troponin increase is of 5-40% after percutaneous coronary interventions and is significantly higher in patients undergoing stenting than in patients with balloon angioplasty only. Four mechanisms are responsible for myocardial necrosis during coronary angioplasty: 1) distal embolization of small fragments of the atherosclerotic plaque; 2) side branch occlusion; 3) intimal dissection, and 4) temporary vessel occlusion. The multiple and/or complex lesions, the diabetic status and plaque instability increase the probability of troponin elevation during coronary angioplasty. Moreover, the long time needed for interventional as well as atherectomy procedures may induce myocardial necrosis. In conclusion, after successful percutaneous coronary interventions, minor elevation of troponin may occur. In this setting cardiac troponin I is a highly specific marker of myocardial injury.