Publications by authors named "Richard Schatz"

This study investigates the potential of long-wave infrared (LWIR) free-space optical (FSO) transmission using multilevel signals to achieve high spectral efficiency. The FSO transmission system includes a directly modulated-quantum cascade laser (DM-QCL) operating at 9.1 µm and a mercury cadmium telluride (MCT) detector.

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The large mid-infrared (MIR) spectral region, ranging from 2.5 µm to 25 µm, has remained under-exploited in the electromagnetic spectrum, primarily due to the absence of viable transceiver technologies. Notably, the 8-14 µm long-wave infrared (LWIR) atmospheric transmission window is particularly suitable for free-space optical (FSO) communication, owing to its combination of low atmospheric propagation loss and relatively high resilience to turbulence and other atmospheric disturbances.

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Aims: A comparison of diagnostic performance comparing AI-QCT, coronary computed tomography angiography using fractional flow reserve (CT-FFR), and physician visual interpretation on the prediction of invasive adenosine FFR have not been evaluated. Furthermore, the coronary plaque characteristics impacting these tests have not been assessed.

Methods And Results: In a single centre, 43-month retrospective review of 442 patients referred for coronary computed tomography angiography and CT-FFR, 44 patients with CT-FFR had 54 vessels assessed using intracoronary adenosine FFR within 60 days.

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An optical amplification-free deep reservoir computing (RC)-assisted high-baudrate intensity modulation direct detection (IM/DD) system is experimentally demonstrated using a 100G externally modulated laser operated in C-band. We transmit 112 Gbaud 4-level pulse amplitude modulation (PAM4) and 100 Gbaud 6-level PAM (PAM6) signals over a 200-m single-mode fiber (SMF) link without any optical amplification. The decision feedback equalizer (DFE), shallow RC, and deep RC are adopted in the IM/DD system to mitigate impairment and improve transmission performance.

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High bitrate mid-infrared links using simple (NRZ) and multi-level (PAM-4) data coding schemes have been realized in the 8 µm to 14 µm atmospheric transparency window. The free space optics system is composed of unipolar quantum optoelectronic devices, namely a continuous wave quantum cascade laser, an external Stark-effect modulator and a quantum cascade detector, all operating at room-temperature. Pre- and post-processing are implemented to get enhanced bitrates, especially for PAM-4 where inter-symbol interference and noise are particularly detrimental to symbol demodulation.

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An approach for simultaneous modulation format identification (MFI) and optical signal-to-noise ratio (OSNR) monitoring in digital coherent optical communications is proposed based on optoelectronic reservoir computing (RC) and the signal's amplitude histograms (AHs) obtained after the adaptive post-equalization. The optoelectronic RC is implemented using a Mach-Zehnder modulator and optoelectronic delay feedback loop. We investigate the performance of the proposed model with the number of symbols, bins of AHs and the hyperparameters of optoelectronic RC.

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Background: Most cell therapy trials failed to show an improvement in global left ventricular (LV) function measures after myocardial infarction (MI). Myocardial segments are heterogeneously impacted by MI. Global LV function indices are not able to detect the small treatment effects on segmental myocardial function which may have prognostic implications for cardiac events.

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Primary percutaneous coronary intervention (PCI) is now the recommended reperfusion technique for patients with acute ST-segment elevation myocardial infarction. However, despite early reperfusion in the majority of patients, PCI does not achieve effective myocardial reperfusion in a significant proportion of patients due to the prevalence of coronary microvascular obstruction. The amount of infarcted myocardium has been considered to be a reliable indicator of major adverse cardiovascular events and resultant adverse left ventricular remodeling.

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Myocardial free wall rupture is a rare but usually fatal complication of acute myocardial infarction (MI) especially if it occurs out of hospital and occurs in 2-4% of patients who suffer from acute MI. Rapid diagnosis is essential but not always easy as diagnostic tests may be inconclusive. In this case report authors examine a rare and unique patient survival after left ventricular free wall rupture following MI.

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Background: Regenerative therapies offer new approaches to improve cardiac function after acute ST-elevation myocardial infarction (STEMI). Previous trials using bone marrow cells, selected stem cell populations, or cardiac stem cell progenitors require invasive procedures and had so far inconclusive results. A less invasive approach utilizes granulocyte-colony stimulating factor (G-CSF) to mobilize stem cells to circulating blood and induce neovascularization and differentiation into endothelial cells and cardiomyocytes.

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Aims: Cardiosphere-derived cells (CDCs) are cardiac progenitor cells that exhibit disease-modifying bioactivity in various models of cardiomyopathy and in previous clinical studies of acute myocardial infarction (MI), dilated cardiomyopathy, and Duchenne muscular dystrophy. The aim of the study was to assess the safety and efficacy of intracoronary administration of allogeneic CDCs in the multicentre, randomized, double-blinded, placebo-controlled, intracoronary ALLogeneic heart STem cells to Achieve myocardial Regeneration (ALLSTAR) trial.

Methods And Results: We enrolled patients 4 weeks to 12 months after MI, with left ventricular ejection fraction (LVEF) ≤45% and LV scar size ≥15% of LV mass by magnetic resonance imaging (MRI).

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We demonstrate a direct-modulation and direct-detection system with a back-to-back line rate of 411.6 (net bit rate of 337.5) Gb/s using a 65 GHz DFB+R laser.

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Esophagitis dissecans superficialis is a rare clinical endoscopic finding with poorly understood pathogenesis and ill-defined management. A 71-year-old man is admitted with progressively worsening dysphagia and odynophagia with endoscopic features most consistent with severe esophagitis dissecans superficialis. Extensive workup did not reveal an etiology, and he was subsequently treated with steroids, resulting in rapid, almost complete clinical and endoscopic recovery.

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A BiCMOS chip-based real-time intensity modulation/direct detection spatial division multiplexing system is experimentally demonstrated for both optical interconnects. 100 Gbps/λ/core electrical duobinary (EDB) transmission over 1 km 7-core multicore fiber (MCF) is carried out, achieving KP4 forward error correction (FEC) limit (BER < 2E-4). Using optical dispersion compensation, 7 × 100 Gbps/λ/core transmission of both non-return-to-zero (NRZ) and EDB signals over 10 km MCF transmission is achieved with BER lower than 7% overhead hard-decision FEC limit (BER < 3.

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We experimentally demonstrate the transmission of a 200 Gbit/s discrete multitone (DMT) at the soft forward error correction limit in an intensity-modulation direct-detection system with a single C-band packaged distributed feedback laser and traveling-wave electro absorption modulator (DFB-TWEAM), digital-to-analog converter and photodiode. The bit-power loaded DMT signal is transmitted over 1.6 km standard single-mode fiber with a net rate of 166.

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Aims: Autologous CD34+ (auto-CD34+) cells represent an attractive option for the treatment of refractory angina. Three double-blinded randomized trials (n = 304) compared intramyocardial (IM) auto-CD34+ cells with IM placebo injections to affect total exercise time (TET), angina frequency (AF), and major adverse cardiac events (MACE). Patient-level data were pooled from the Phase I, Phase II ACT-34, ACT-34 extension, and Phase III RENEW trials to determine the efficacy and safety of auto-CD34+ cells.

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A differential pulse code modulation (DPCM) based digital mobile fronthaul architecture is proposed and experimentally demonstrated. By using a linear predictor in the DPCM encoding process, the quantization noise can be effectively suppressed and a prediction gain of 7~8 dB can be obtained. Experimental validation is carried out with a 20 km 15-Gbaud/λ 4-level pulse amplitude modulation (PAM4) intensity modulation and direct detection system.

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Fibromyalgia (FM) has historically been associated with several diseases in gastroenterology and hepatology. The most substantiated evidence pertains to irritable bowel syndrome (IBS). The pathogeneses of FM and IBS remain unclear, but it is likely related to dysregulation within the brain-gut axis, resulting in a hyperalgesic state.

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Objectives: To assess subjects' perception of healthcare costs and physician reimbursement.

Background: The lack of transparency in healthcare reimbursement leaves patients and physicians unaware of the distribution of health care dollars.

Methods: Anonymous survey-based study by means of convenience sampling.

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Gigabit free-space transmissions are experimentally demonstrated with a quantum cascaded laser (QCL) emitting at mid-wavelength infrared of 4.65 μm, and a commercial infrared photovoltaic detector. The QCL operating at room temperature is directly modulated using on-off keying and, for the first time, to the best of our knowledge, four- and eight-level pulse amplitude modulations (PAM-4, PAM-8).

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The history of coronary angioplasty began with the groundbreaking work of Andreas Grüntzig, who was the first to use balloon-expandable catheters for the treatment of flow-limiting atherosclerotic coronary artery lesions. Thereafter, early investigators tested self-expanding springs as a solution to abrupt closure and restenosis seen with balloon angioplasty but these devices suffered from difficult delivery and a high complication rate. Julio Palmaz and Richard Schatz introduced the first balloon-expandable stent as a mechanical support to improve vessel patency.

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Coherent communication networks are based on the ability to use multiple dimensions of the lightwave together with electrical domain compensation of transmission impairments. Electrical-domain dispersion compensation (EDC) provides many advantages such as network flexibility and enhanced fiber nonlinearity tolerance, but makes the system more susceptible to laser frequency noise (FN), e.g.

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