957 research outputs found

    Influence of the absorber dimensions on wavefront shaping based on volumetric optoacoustic feedback

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    The recently demonstrated control over light distribution through turbid media based on real-time three-dimensional optoacoustic feedback has offered promising prospects to interferometrically focus light within scattering objects. Nevertheless, the focusing capacity of the feedback-based approach is strongly conditioned by the number of effectively resolvable optical modes (speckles). In this letter, we experimentally tested the light intensity enhancement achieved with optoacoustic feedback measurements from different sizes of absorbing microparticles. The importance of the obtained results is discussed in the context of potential signal enhancement at deep locations within a scattering medium where the effective speckle sizes approach the minimum values dictated by optical diffraction

    The Resilience of Massive MIMO PNC to Jamming Attacks in Vehicular Networks

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    In this article, we investigate the resilience of Massive MIMO Physical Layer Network Coding (PNC) to jamming attack in both sub-6 GHz and millimeter-Wave (mmWave) systems in vehicular networks. Massive MIMO generally is resilient to jamming attacks, and we investigate the impact that PNC has on this resilience, if combined with Massive MIMO. The combination of Massive MIMO and PNC has shown a significant improvement in the bit error rate (BER) in our previous investigation. The corresponding framework is analysed against a barraging attack from a jammer, where the jamming channel is not known to the base station (BS), and the jammer can use any number of transmit antennas. Over Rayleigh channel, our simulation results reveal that Massive MIMO PNC performs better in the lower signal-to-noise ratio (SNR) regions to jamming attacks and this is achieved at twice the spectral efficiency. A similar performance is observed over mmWave channel

    Pancreatic pseudocyst eroding into the splenoportal venous confluence and mimicking an arterial aneurysm

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    We report the case of a 62-year-old man with chronic pancreatitis who presented with increasing abdominal pain. Sonography, magnetic resonance imaging, contrast-enhanced computed tomography, and ultimately catheter angiography demonstrated a pancreatic pseudocyst that had eroded into the splenoportal venous confluence, mimicking an arterial aneurysm. The diagnostic was confirmed at the time of surgical treatment. This case demonstrates the use of imaging to diagnose complications of pancreatitis, and the difficulty of distinguishing an eroding pseudocyst from an arterial aneurysm

    PHP94 Analysis of Results of the Reference Pricing of Turkey

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    Using Expert Opinion to Quantify Uncertainty in and Cost of Using Nondestructive Evaluation on Bridges

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    A previous literature review indicated that there is little published experimental data that can be used to determine quantities such as bias, accuracy, reliability, and cost of common Nondestructive Evaluation (NDE) methods as far as their use on bridges is concerned. This study attempts to quantify these parameters for common bridge NDE methods through a four-round Delphi method survey with experts in the NDE bridge field. The survey results indicate that most commonly used bridge NDE methods tend to be underbiased and relatively reliable. Furthermore, the accuracy of commonly used bridge NDE methods tends to be relatively variable with the average test measuring a true response between 80% and 85% of the time. In general, it was shown by the participant responses that the more expensive the method was, the better the bias, accuracy, and reliability the method had, and vice versa. The information presented in this paper can serve as a starting point for characterizing different NDE methods for use in bridge management and inspection planning and identifies the type of information that is still needed. As such, this research has the potential to promote further research on this subject

    Response of pulmonary artery intimal sarcoma to surgery, radiotherapy and chemotherapy: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Pulmonary artery intimal sarcoma is a rare disease with no characteristic symptoms. It is difficult to diagnose early and is frequently misdiagnosed as a pulmonary embolism.</p> <p>Case presentation</p> <p>Here we report a case of pulmonary artery intimal sarcoma in a 54-year-old woman presenting with complaints of shortness of breath on exertion. Echocardiography and a computed tomography scan showed that the right pulmonary artery trunk was blocked by a low-density mass. The patient was diagnosed with pulmonary artery intimal sarcoma by pathology and a complete mass resection was performed. After experiencing 10 months of disease-free survival, she was re-admitted because of the recurrence and metastasis of the tumor. Radiotherapy and chemotherapy were performed; however, only limited success was achieved. The patient died 15 months after the initial onset of symptoms.</p> <p>Conclusion</p> <p>Some patients with intimal sarcoma of the pulmonary artery can benefit from radiotherapy and chemotherapy as well as surgery.</p
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