Entanglement swapping with local certification: application to remote micromechanical resonators.

We propose a protocol for entanglement swapping which involves tripartite systems. The generation of remote entanglement induced by the Bell measurement can be easily certified by additional local measurements. We illustrate the protocol in the case of continuous variable systems where the certification is effective for an appropriate class of three-mode gaussian states. We then apply the protocol to optomechanical systems, showing how mechanical entanglement between two remote micromechanical resonators can be generated and certified via local optical measurements.

Reversible optical-to-microwave quantum interface.

We describe a reversible quantum interface between an optical and a microwave field using a hybrid device based on their common interaction with a micromechanical resonator in a superconducting circuit. We show that, by employing state-of-the-art optoelectromechanical devices, one can realize an effective source of (bright) two-mode squeezing with an optical idler (signal) and a microwave signal, which can be used for high-fidelity transfer of quantum states between optical and microwave fields by means of continuous variable teleportation.

Percutaneous ultrasonography-guided core needle biopsy of gastrointestinal lesions: what's its actual role in clinical practice? A retrospective study for safety and effectiveness.

PURPOSE: Endoscopic biopsy is commonly performed to obtain a pathological diagnosis of gastrointestinal (GI) lesions. When the lesions are submucosal, subserosal, or exophytic, endoscopic biopsy is often unsuccessful, and endoscopic ultrasound (EUS)-guided biopsy is considered the procedure of choice in these cases. Nevertheless, in some patients both endoscopic and EUS-guided biopsy are not indicated, or yield inconclusive cyto-histological results. The aim of this study was to assess the efficacy and safety of percutaneous ultrasonography (US)-guided biopsy of GI wall lesions, and to define its actual role in clinical practice. MATERIALS AND METHODS: A retrospective study was conducted on 45 consecutive US-guided biopsies of GI lesions. All biopsies were performed in patients unsuitable for endoscopic or EUS-guided biopsy, or with lesions inaccessible to endoscopic techniques, or with inconclusive results from endoscopic or EUS-guided biopsy. Biopsies were performed with an 18 or 20-gauge Tru-cut needle under US guidance. Biopsy results were compared with the final diagnosis that was based on surgical pathological findings or clinical instrumental follow-up of at least 20 months. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), overall accuracy, and complication rate of the procedure were calculated. RESULTS: One biopsy specimen (2.2 %) was inadequate for cyto-histologic examination. In the remaining 44 cases, US-guided biopsy correctly identified 39 / 40 (97.5 %) malignant lesions, and 4 / 4 (100 %) benign lesions. One case resulted in a false negative (2.2 %). The sensitivity, specificity, PPV, NPV, and overall diagnostic accuracy were 97.5 %, 100 %, 100 %, 80 % and 97.7 %, respectively. Including also the inadequate specimen into the analysis, they were 95.1 %, 100 %, 100 %, 66.7 % and 95.6 %, respectively. No procedure-related complications were observed. In ten cases (22.2 %), US-guided biopsy results made it possible to avoid unnecessary surgical exploration. CONCLUSION: Percutaneous US-guided core biopsy of GI wall lesions is an accurate and safe technique that makes it possible in select cases to obtain a correct pathological diagnosis and prevent unnecessary surgical exploration. Although it has been replaced by EUS-guided biopsy as the procedure of choice to sample submucosal or subserosal GI lesions, US-guided biopsy can still play a useful role in the diagnostic workup of GI lesions when endoscopy or EUS is unsuccessful for various reasons or yields inconclusive cyto-histological results.

Experimental inhibition of decoherence on flying qubits via "bang-bang" control.

Decoherence may significantly affect the polarization state of optical pulses propagating in dispersive media because of the unavoidable presence of more than a single frequency in the envelope of the pulse. Here we report on the suppression of polarization decoherence in a ring cavity obtained by properly retooling for photonic qubits the "bang-bang" protection technique already employed for nuclear spins and nuclear-quadrupole qubits. Our results show that bang-bang control can be profitably extended to quantum information processes involving flying polarization qubits.

Transthoracic ultrasonography-guided core needle biopsy of pleural-based lung lesions: prospective randomized comparison between a Tru-cut-type needle and a modified Menghini-type needle.

PURPOSE: The diagnostic yield of the different types of cutting needles used to perform transthoracic biopsy is scarcely investigated. Aim of the study was to compare a Tru-cut-type (TCT) needle and a modified Menghini-type needle (MMT) in ultrasonography (US)-guided biopsy of pulmonary lesions. MATERIALS AND METHODS: 307 subjects (191 males and 116 females, mean age 58 years) with peripheral lung lesions selected to undergo US-guided biopsy were randomized to undergo biopsy by using an 18-gauge TCT or MMT needle. The specimens were imprinted on two to three slides for cytology and then put into a formalin solution for histology. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy were calculated. Fisher's exact test was used to compare histology recovery rate (HRR), diagnostic accuracy, and diagnostic yield of the combination of cytology and histology in comparison with cytology alone and histology alone. RESULTS: 155 biopsies were performed using the MMT needle, 152 using the TCT needle. HRR was 112 / 155 (72.3 %) and 144 / 152 (94.7 %), respectively (p < 0.0001). Sensitivity, specificity, PPV, and NPV were 81.6 %, 100 %, 100 %, and 62 % for the former, respectively, and 93.6 %, 100 %, 100 %, and 86 % for the latter. A correct diagnosis was achieved in 133 / 155 biopsies (85.8 %) performed with the MMT needle, and in 145 / 152 biopsies (95.4 %) performed with the TCT needle (p = 0.0041). The combination of cytology and histology had a higher diagnostic yield than cytology alone (p < 0.001) and histology alone (p < 0.001). CONCLUSION: The TCT needle performs better than the MMT needle, and improves the diagnostic accuracy of US-guided transthoracic biopsy of superficial lung lesions.

Clinical features of sarcomatoid renal cell carcinoma causing bilateral urinary tract obstruction.

We report on a 52-year-old female patient hospitalized because of uremia due to bilateral urinary tract obstruction caused by bilateral sarcomatoid renal cell carcinoma (SRCC). Abdominal computed tomography with contrast showed a large mass on the left side, infiltrating the left kidney, while the right kidney was described as enlarged. The latter was investigated with sonographic angiography using contrast and selective arteriography of the renal arteries, demonstrating a pseudonodular area at the inferior pole of the right kidney. The patient underwent bilateral nephrectomy and chronic hemodialysis treatment; unfortunately, after one month she died from cachexia. To the best of our knowledge this is the first case to be reported on bilateral SRCC causing bilateral urinary tract obstruction.

Optomechanical entanglement between a movable mirror and a cavity field.

We show how stationary entanglement between an optical cavity field mode and a macroscopic vibrating mirror can be generated by means of radiation pressure. We also show how the generated optomechanical entanglement can be quantified, and we suggest an experimental readout scheme to fully characterize the entangled state. Surprisingly, such optomechanical entanglement is shown to persist for environment temperatures above 20 K using state-of-the-art experimental parameters.

Scalable quantum processor with trapped electrons.

A quantum computer can be implemented by trapping electrons in vacuum within an innovative confining structure. Universal processing is realized by controlling the Coulomb interaction and applying electromagnetic pulses. This system offers scalability, high clock speed, and low decoherence.

Complete quantum teleportation with a kerr nonlinearity

We present a scheme for the quantum teleportation of the polarization state of a photon employing a cross-Kerr medium. The experimental feasibility of the scheme is discussed and we show that, using the recently demonstrated ultraslow light propagation in cold atomic media, our proposal can be realized with presently available technology.

Toward a tomographic picture of a Bose-Einstein condensate.

The possibilities of applying tomographic techniques to a Bose-Einstein condensate to reconstruct its ground state are investigated by means of numerical simulations. Two situations for which the density-matrix elements can be retrieved from atom counting probabilities are considered. The methods presented here allow one to distinguish among various possible quantum states.