Universally Robust Quantum Control.

We study the robustness of the evolution of a quantum system against small uncontrolled variations in parameters in the Hamiltonian. We show that the fidelity susceptibility, which quantifies the perturbative error to leading order, can be expressed in superoperator form and use this to derive control pulses that are robust to any class of systematic unknown errors. The proposed optimal control protocol is equivalent to searching for a sequence of unitaries that mimics the first-order moments of the Haar distribution, i.e., it constitutes a 1-design. We highlight the power of our results for error-resistant single- and two-qubit gates.

Collision Models Can Efficiently Simulate Any Multipartite Markovian Quantum Dynamics.

We introduce the multipartite collision model, defined in terms of elementary interactions between subsystems and ancillas, and show that it can simulate the Markovian dynamics of any multipartite open quantum system. We develop a method to estimate an analytical error bound for any repeated interactions model, and we use it to prove that the error of our scheme displays an optimal scaling. Finally, we provide a simple decomposition of the multipartite collision model into elementary quantum gates, and show that it is efficiently simulable on a quantum computer according to the dissipative quantum Church-Turing theorem, i.e., it requires a polynomial number of resources.

The growth of non-solid neoplastic lung nodules is associated with low PD L1 expression, irrespective of sampling technique.

BACKGROUND: Few data are known regarding the molecular features and patterns of growth and presentation which characterize those lung neoplastic lesions presenting as non-solid nodules (NSN). METHODS: We retrospectively reviewed two different cohorts of NSNs detected by CT scan which, after transthoracic fine-needle aspiration (FNA) and core needle biopsy (CNB) received a final diagnosis of malignancy. All the enrolled patients were then addressed to surgical removal of lung cancer nodules or to exclusive radiotherapy. Exhaustive clinical and radiological features were available for each case. RESULTS: In all 62 analysed cases the diagnosis of adenocarcinoma (ADC) was reached. In cytologic samples, EGFR activating mutations were identified in 2 of the 28 cases (7%); no case showed ALK/EML4 or ROS1 translocations. In the histologic samples EGFR activating mutation were found in 4 out of 25 cases (16%). PD-L1 immunostains could be evaluated in 30 cytologic samples, while the remaining 7 did not reach the cellularity threshold for evaluation. TPS was < 1% in 26 cases, > 1% < 50% in 3, and > 50% in 1. All surgical samples showed TPS < 1%. Of the 17 cases that could be evaluated on both samples, 15 were concordantly TPS 0, and 2 showed TPS > 1% < 50 on the biopsy samples. TPS was < 1% in 14 cases, > 1%/< 5% in 4 cases, > 5%/< 50% in 2 cases, > 50% in 1 case. CONCLUSIONS: Overall PD-L1 immunostaining documented the predominance of low/negative TPS, with high concordance in FNA and corresponding surgical samples. It can be hypothesized that lung ADC with NSN pattern and predominant in situ (i.e. lepidic) components represent the first steps in tumor progression, which have not yet triggered immune response, and/or have not accumulated a significant rate of mutations and neoantigen production, or that they belong to the infiltrated-excluded category of tumors. The negative prediction of response to immunomodulating therapy underlines the importance of rapid surgical treatment of these lesions. Notably, cell block cytology seems to fail in detecting EGFR mutations, thus suggesting that this kind of sampling technique should be not adequate in case of DNA direct sequencing.

Thermodynamics of Weakly Coherent Collisional Models.

We introduce the idea of weakly coherent collisional models, where the elements of an environment interacting with a system of interest are prepared in states that are approximately thermal but have an amount of coherence proportional to a short system-environment interaction time in a scenario akin to well-known collisional models. We show that, in the continuous-time limit, the model allows for a clear formulation of the first and second laws of thermodynamics, which are modified to include a nontrivial contribution related to quantum coherence. Remarkably, we derive a bound showing that the degree of such coherence in the state of the elements of the environment represents a resource, which can be consumed to convert heat into an ordered (unitarylike) energy term in the system, even though no work is performed in the global dynamics. Our results therefore represent an instance where thermodynamics can be extended beyond thermal systems, opening the way for combining classical and quantum resources.

A cloud-based computer-aided detection system improves identification of lung nodules on computed tomography scans of patients with extra-thoracic malignancies.

OBJECTIVES: To compare unassisted and CAD-assisted detection and time efficiency of radiologists in reporting lung nodules on CT scans taken from patients with extra-thoracic malignancies using a Cloud-based system. MATERIALS AND METHODS: Three radiologists searched for pulmonary nodules in patients with extra-thoracic malignancy who underwent CT (slice thickness/spacing 2 mm/1.7 mm) between September 2015 and March 2016. All nodules detected by unassisted reading were measured and coordinates were uploaded on a cloud-based system. CAD marks were then reviewed by the same readers using the cloud-based interface. To establish the reference standard all nodules ≥ 3 mm detected by at least one radiologist were validated by two additional experienced radiologists in consensus. Reader detection rate and reporting time with and without CAD were compared. The study was approved by the local ethics committee. All patients signed written informed consent. RESULTS: The series included 225 patients (age range 21-90 years, mean 62 years), including 75 patients having at least one nodule, for a total of 215 nodules. Stand-alone CAD sensitivity for lesions ≥ 3 mm was 85% (183/215, 95% CI: 82-91); mean false-positive rate per scan was 3.8. Sensitivity across readers in detecting lesions ≥ 3 mm was statistically higher using CAD: 65% (95% CI: 61-69) versus 88% (95% CI: 86-91, p<0.01). Reading time increased by 11% using CAD (296 s vs. 329 s; p<0.05). CONCLUSION: In patients with extra-thoracic malignancies, CAD-assisted reading improves detection of ≥ 3-mm lung nodules on CT, slightly increasing reading time. KEY POINTS: • CAD-assisted reading improves the detection of lung nodules compared with unassisted reading on CT scans of patients with primary extra-thoracic tumour, slightly increasing reading time. • Cloud-based CAD systems may represent a cost-effective solution since CAD results can be reviewed while a separated cloud back-end is taking care of computations. • Early identification of lung nodules by CAD-assisted interpretation of CT scans in patients with extra-thoracic primary tumours is of paramount importance as it could anticipate surgery and extend patient life expectancy.

Genuine quantum correlations in quantum many-body systems: a review of recent progress.

Quantum information theory has considerably helped in the understanding of quantum many-body systems. The role of quantum correlations and in particular, bipartite entanglement, has become crucial to characterise, classify and simulate quantum many body systems. Furthermore, the scaling of entanglement has inspired modifications to numerical techniques for the simulation of many-body systems leading to the, now established, area of tensor networks. However, the notions and methods brought by quantum information do not end with bipartite entanglement. There are other forms of correlations embedded in the ground, excited and thermal states of quantum many-body systems that also need to be explored and might be utilised as potential resources for quantum technologies. The aim of this work is to review the most recent developments regarding correlations in quantum many-body systems focussing on multipartite entanglement, quantum nonlocality, quantum discord, mutual information but also other non classical measures of correlations based on quantum coherence. Moreover, we also discuss applications of quantum metrology in quantum many-body systems.

Shortcut to adiabaticity in the Lipkin-Meshkov-Glick model.

We study transitionless quantum driving in an infinite-range many-body system described by the Lipkin-Meshkov-Glick model. Despite the correlation length being always infinite the closing of the gap at the critical point makes the driving Hamiltonian of increasing complexity also in this case. To this aim we develop a hybrid strategy combining a shortcut to adiabaticity and optimal control that allows us to achieve remarkably good performance in suppressing the defect production across the phase transition.

Experimental reconstruction of work distribution and study of fluctuation relations in a closed quantum system.

We report the experimental reconstruction of the nonequilibrium work probability distribution in a closed quantum system, and the study of the corresponding quantum fluctuation relations. The experiment uses a liquid-state nuclear magnetic resonance platform that offers full control on the preparation and dynamics of the system. Our endeavors enable the characterization of the out-of-equilibrium dynamics of a quantum spin from a finite-time thermodynamics viewpoint.

Thermodynamics of hybrid quantum rotor devices.

We investigate the thermodynamics of a hybrid quantum device consisting of two qubits collectively interacting with a quantum rotor and coupled dissipatively to two equilibrium reservoirs at different temperatures. By modeling the dynamics and the resulting steady state of the system using a collision model, we identify the functioning of the device as a thermal engine, a refrigerator, or an accelerator. In addition, we also look into the device's capacity to operate as a heat rectifier and optimize both the rectification coefficient and the heat flow simultaneously. Drawing an analogy to heat rectification and since we are interested in the conversion of energy into the rotor's kinetic energy, we introduce the concept of angular momentum rectification, which may be employed to control work extraction through an external load.

Thoracic Spine CT Hidden Treasures: Lung Assessment and Extraspinal Findings in Patients with Vertebral Fractures Studied with Full FOV during Breath Hold: Technical Note.

Thoracic spine CTs are usually performed during free breathing and with a narrow field of view; this common practice systematically excludes the assessment of lungs and other extraspinal structures, even if these have been irradiated during the examination. At our institution we perform thoracic spine CT during breath hold with additional full FOV reconstructions; this allows us to also evaluate lungs and extraspinal pathologies in the same examination with no added costs or further radiation exposure. If this simple and costless technical change is routinely applied to thoracic spine CT many concomitant extraspinal pathologies can be ruled out, from neoplasms to pneumonia; the suggested modification also allows an early diagnosis and avoids recalling and re-irradiating the patient in case these findings are partially included in the study. This practice can be further useful during the current pandemic in order to screen any lung opacities suspicious for COVID-19.

Painful pathologic fracture of the humerus: percutaneous osteoplasty with bone marrow nails under hybrid computed tomography and fluoroscopic guidance.

A case of a 75-year-old patient with a painful pathologic humeral shaft fracture, with unacceptably high surgical risk and unsatisfactory analgesia is reported. In this case, impaired arm function and persistent pain with conservative management resulted in a poor quality of life. Palliation with image-guided percutaneous osteoplasty was considered. Because of potential cement leakage, inadequate fracture reduction, the site of the fracture, and the mobility of the joints in that area, image-guided percutaneous delivery of metallic bone marrow nails implanted together with polymethyl methacrylate (PMMA) osteoplasty was performed. This procedure achieved humeral shaft stabilization, bone fragment alignment, fracture reduction, and pain relief.

Percutaneous vertebroplasty in osteoporotic patients: an institutional experience of 1,634 patients with long-term follow-up.

PURPOSE: To assess long-term clinical outcome of percutaneous vertebroplasty (PV). MATERIALS AND METHODS: PV was performed in 1,634 patients (1,387 women; median age 73 years ± 9.3) with painful osteoporotic vertebral compression fractures (VCFs). All patients had back pain that persisted for ≥ 2 months with a concordant magnetic resonance imaging study. After PV, medical therapy for osteoporosis was continued, and patients were prospectively evaluated (follow-up 11.8-44.9 months, mean 25.0 months). Visual analog scale (VAS), Oswestry Disability Index (ODI), analgesic drug use, and use of external brace support were recorded at baseline and during follow-up. New occurrences of symptomatic vertebral fractures were recorded. RESULTS: The mean VAS score of 7.94 significantly improved to 1.12 at the primary endpoint (P < .001). Differences in patterns of analgesic usage compared with baseline values were highly statistically significant (marginal homogeneity test, P < .001). Median ODI values of 82% before treatment significantly decreased to 6% (P < .001). Before intervention, 1,279 patients wore a brace; 1,167 (91.2%) patients did not wear a brace after PV (χ(2) = 31.005, P < .0001). A new painful fracture with a significant higher proportion of contiguous vertebrae (63.6%) occurred in 214 (13.1%) patients (z = 7.59, P = .025). CONCLUSIONS: PV can provide durable pain relief and improvement in ambulation in patients with VCFs.

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.

Quasistatic and quantum-adiabatic Otto engine for a two-dimensional material: The case of a graphene quantum dot.

In this work, we study the performance of a quasistatic and quantum-adiabatic magnetic Otto cycles with a working substance composed of a single graphene quantum dot modeled by the continuum approach with the use of the zigzag boundary condition. Modulating an external or perpendicular magnetic field, in the quasistatic approach, we found a constant behavior in the total work extracted that is not present in the quantum-adiabatic formulation. We find that, in the quasistatic approach, the engine yielded a greater performance in terms of total work extracted and efficiency as compared with its quantum-adiabatic counterpart. In the quasistatic case, this is due to the working substance being in thermal equilibrium at each point of the cycle, maximizing the energy extracted in the adiabatic strokes.

Impact of a risk-based follow-up in patients affected by gastrointestinal stromal tumour.

BACKGROUND: Follow-up aims to precociously identify recurrences, metastases or treatment-related adverse events so as to undertake the appropriate therapy. Guidelines admit lack of knowledge on optimal surveillance schedule, but suggest follow-up based on experts' opinion and risk stratification. To identify the impact, if any, of regular follow-up, we interrogated our prospectively collected database whether early detection of recurrences affected both clinical management and, likely, the outcome. PATIENTS AND METHODS: We required information to be available on primary surgery and ≥3°years of follow-up for non-recurring patients. We analysed recurrence characteristics (asymptomatic versus symptomatic, low- versus high tumour burden) and computed tomography (CT) scan counts to detect one recurrence. Kaplan-Meier method estimated recurrence-free survival (RFS), post-recurrence progression-free survival (PR-PFS), and disease-specific overall survival (OS). Comparisons used Hazard ratios (HR) with 95% confidence intervals (CIs). Multivariate analyses employed the Cox proportional hazards model. All tests were two-sided. RESULTS: Between 01/2001 and 12/2012 we found 233 study-eligible patients. Estimated 5- and 10-year RFS were 61.8% and 50.4%, respectively. After a 68-month median follow-up, we observed 94 (40.3%) recurrences [73/94 (77.7%) asymptomatic versus 21/94 (22.3%) symptomatic and 45/94 (47.9%) low- versus 49/94 (52.1%) high tumour burden]. Multivariate analysis revealed that symptomatic and high tumour burden recurrences were highly predictive of both worse PR-PFS (HR:3.19, P < 0.001; HR:2.80, P = 0.003, respectively) and OS (HR:3.65, P < 0.001; HR:2.38, P = 0.026, respectively). Finally, 29 second (primary) cancers were detected during follow-up. CONCLUSIONS: Regular follow-up detects recurrences at an earlier stage and may be associated with a better PR-PFS and OS for these patients. In the absence of randomised trials, these evidences support follow-up effort and cost.

Equilibration and nonclassicality of a double-well potential.

A double well loaded with bosonic atoms represents an ideal candidate to simulate some of the most interesting aspects in the phenomenology of thermalisation and equilibration. Here we report an exhaustive analysis of the dynamics and steady state properties of such a system locally in contact with different temperature reservoirs. We show that thermalisation only occurs 'accidentally'. We further examine the nonclassical features and energy fluxes implied by the dynamics of the double-well system, thus exploring its finite-time thermodynamics in relation to the settlement of nonclassical correlations between the wells.

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 nonoptimal 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 a 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 nonoptimal processes are considered. Our work shows the importance of better understanding the complex interconnections between nonequilibrium thermodynamics of quantum systems and correlations among their subparts.

Vertebral augmentation with nitinol endoprosthesis: clinical experience in 40 patients with 1-year follow-up.

PURPOSE: This study was designed to assess the clinical outcomes of patients treated by vertebral augmentation with nitinol endoprosthesis (VNE) to treat painful vertebral compression fractures. METHODS: Forty patients with one or more painful osteoporotic VCF, confirmed by MRI and accompanied by back-pain unresponsive to a minimum 2 months of conservative medical treatment, underwent VNE at 42 levels. Preoperative and postoperative pain measured with Visual Analog Scale (VAS), disability measured by Oswestry Disability Index (ODI), and vertebral height restoration (measured with 2-dimensional reconstruction CT) were compared at last follow-up (average follow-up 15 months). Cement extravasation, subsequent fractures, and implant migration were recorded. RESULTS: Long-term follow-up was obtained in 38 of 40 patients. Both VAS and ODI significantly improved from a median of 8.0 (range 5-10) and 66 % (range 44-88 %) to 0.5 (range 0-8) and 6 % (range 6-66 %), respectively, at 1 year (p < 0.0001). Vertebral height measurements comparing time points increased in a statistically significant manner (ANOVA, p < 0.001). Overall cement extravasation rate was 9.5 %. Discal and venous leakage rates were 7.1 and 0 % respectively. No symptomatic extravasations occurred. Five of 38 (13.1 %) patients experienced new spontaneous, osteoporotic fractures. No device change or migration was observed. CONCLUSIONS: VNE is a safe and effective procedure that is able to provide long-lasting pain relief and durable vertebral height gain with a low rate of new fractures and cement leakages.