Realization and characterization of a 2-photon 4-qubit linear cluster state

We report on the experimental realization of a 4-qubit linear cluster state via two photons entangled both in polarization and linear momentum. This state was investigated by performing tomographic measurements and by evaluating an entanglement witness. By use of this state we carried out a novel nonlocality proof, the so-called ``stronger two observer all versus nothing'' test of quantum nonlocality.Comment: 4 pages, 4 figure

Observing thermal lensing with quantum light

The introduction of quantum methods in spectroscopy can provide enhanced performance and technical advantages in the management of noise. We investigate the application of quantum illumination in a pump and probe experiment. Thermal lensing in a suspension of gold nanorods is explored using a classical beam as the pump and the emission from parametric downconversion as the probe. We obtain an insightful description of the behaviour of the suspension under pumping with a method known to provide good noise rejection. Our findings are a further step towards investigating effects of quantum light in complex plasmonic media

Safety and efficacy of OAGB/MGB during the learning curve: setting a benchmark in a bariatric center of excellence

: Very little has been published on the learning curve (LC) of the One Anastomosis /Mini Gastric Bypass (OAGB/MGB). Aim of this study was to compare perioperative outcomes of OABG/MGBs performed during the LC of an experienced laparoscopic surgeon to global benchmark cut-offs. First 200 patients undergoing OAGB/MGB at our university hospital from 2010 to 2016 were retrospectively included in this study. LC of the surgeon was divided in two groups of 100 consecutive patients each and perioperative outcomes were compared to abovementioned global benchmarks for LSG and RYGB. A cumulative sum (CUSUM) analysis was performed for operative time and hospital stay. Uneventful postoperative recovery was recorded in 95% of patients. All benchmark values for RYGB were met in group 2. Comparison with cut-offs for LSG showed longer hospital stay and operative time in both groups but postoperative rate of complications resulted lower even for Group 1. CUSUM graph of the operative time runs randomly above the predetermined limit till the 40th cases but reaches the plateau after the 115th operation. CUSUM curve of the hospital stay reaches the plateau after the 57th case. OAGB/MGB confirms to be a feasible procedure, which can be safely and effectively performed during the learning curve. However, at least 100 hundred cases are required to reduce operative time and hospital stay

Diagnostics of quantum-gate coherences via end-point-measurement statistics

Quantum coherence is a central ingredient in quantum physics with several theoretical and technological ramifications. In this work we consider a figure of merit encoding the information on how the coherence generated on average by a quantum gate is affected by unitary errors (coherent noise sources). We provide numerical evidences that such information is well captured by the statistics of local energy measurements on the output states of the gate. These findings are then corroborated by experimental data taken in a quantum optics setting

Singular Spectrum Analysis of Two Photon Interference from Distinct Quantum Emitters

Two-photon interference underlies the functioning of many quantum photonics devices. It also serves as the prominent tool for testing the indistinguishability of distinct photons. However, as their time-spectral profile becomes more involved, extracting relevant parameters, foremost the central frequency difference, may start suffering difficulties. In a parametric approach, these arise from the need for an exhaustive model combined with limited count statistics. Here we discuss a solution to curtail these effects on the evaluation of frequency separation relying on a semiparametric method. The time trace of the quantum interference pattern of two photons from two independent solid-state emitters is preprocessed by means of singular spectral analysis before inspecting its spectral content. This approach allows to single out the relevant oscillations from both the envelope and the noise, without resorting to fitting. This opens the way for robust and efficient on-line monitoring of quantum emitters

Vitamin D Deficiency in Patients with Morbid Obesity before and after Metabolic Bariatric Surgery

Background: Metabolic bariatric surgery (MBS) is the most effective treatment for severe obesity. Vitamin D deficiency is a common complication encountered both during preoperative workup and follow-up. Aim: To estimate the prevalence of vitamin D deficiency in patients undergoing MBS. Methods: Prospectively maintained database of our university MBS center was searched to assess the rate of preoperative and postoperative vitamin D deficiency or insufficiency in patients undergoing MBS over a one-year period. Results: In total, 184 patients were included, 85 cases of Sleeve Gastrectomy (SG), 99 Gastric Bypass (GB; 91 One Anastomosis and 8 Roux-en-Y). Preoperative vitamin D deficiency and insufficiency were respectively found in 61% and 29% of patients, with no significant difference between SG and GB. After six months, 15% of patients had vitamin D deficiency, and 34% had vitamin D insufficiency. There was no significant difference in the rate of vitamin D deficiency or insufficiency and the percentage of total weight loss (%TWL) at 1, 3, and 6 postoperative months between SG and GB. Conclusions: Preoperative vitamin D deficiency or insufficiency is common in MBS candidates. Regular follow-up with correct supplementation is recommended when undergoing MBS. Early postoperative values of vitamin D were comparable between SG and OAGB

Erythropoietin is involved in the angiogenic potential of bone marrow macrophages in multiple myeloma

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Measurement of elastic pp scattering at √s=8 TeV in the Coulomb–nuclear interference region : determination of the ρ -parameter and the total cross-section

The TOTEM experiment at the CERN LHC has measured elastic proton–proton scattering at the centre-of-mass energy √=8TeV and four-momentum transfers squared, |t|, from 6×10−4 to 0.2 GeV2. Near the lower end of the t-interval the differential cross-section is sensitive to the interference between the hadronic and the electromagnetic scattering amplitudes. This article presents the elastic cross-section measurement and the constraints it imposes on the functional forms of the modulus and phase of the hadronic elastic amplitude. The data exclude the traditional Simplified West and Yennie interference formula that requires a constant phase and a purely exponential modulus of the hadronic amplitude. For parametrisations of the hadronic modulus with second- or third-order polynomials in the exponent, the data are compatible with hadronic phase functions giving either central or peripheral behaviour in the impact parameter picture of elastic scattering. In both cases, the -parameter is found to be 0.12±0.03. The results for the total hadronic cross-section are tot=(102.9±2.3) mb and (103.0±2.3) mb for central and peripheral phase formulations, respectively. Both are consistent with previous TOTEM measurements.peer-reviewe

A Real-Time Spectroscopic Sensor for Monitoring Laser Welding Processes

In this paper we report on the development of a sensor for real time monitoring of laser welding processes based on spectroscopic techniques. The system is based on the acquisition of the optical spectra emitted from the laser generated plasma plume and their use to implement an on-line algorithm for both the calculation of the plasma electron temperature and the analysis of the correlations between selected spectral lines. The sensor has been patented and it is currently available on the market

Sigma-2 Receptors as Potential Novel Biomarkers During the Progression of Benign Prostatic Hypertrophy (BPH) into Prostate Cancer

Abstract: BPH could be considered the most common benign tumor for men between 60 and 75 years of age. PSA is an unsatisfactory biomarker to define BPH progression to cancer. Recently, sigma-2 receptors have been recognized in several prostate cancer cell lines such as PC-3, DU-145 and LNCaP. It is reported that, in some cases, BPH could progress to malignancy and this progression can not easily be monitored by biomarkers such as PSA. In this paper we investigated 10 specimens from TURP, finding overexpression of sigma-2 receptors in two of these specimens (specimen 1 and 2) accompanied by 4 ng/mL PSA values. We hypothesize that the presence of sigma-2 receptors is related to a BPH progressing in prostate cancer. A possible correlation between sigma-2 receptors and PSA values could be useful to identify this pathological progression