695 research outputs found

    Superior epigastric artery pseudoaneurysm- a rare complication of chest drain insertion in coronary artery bypass grafting

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    BACKGROUND: Although chest drain insertion during coronary artery bypass grafting is a fairly standard procedure, however it may result in extremely rare complications. CASE PRESENTATION: This is the first case being reported that demonstrates a pseudoaneurysm of superior epigastric artery resulting from chest drain insertion following coronary artery bypass grafting. CONCLUSION: Adequate caution should be used along with good understanding of the anatomical landmarks during apparently simple and standard operative procedures

    A 16-nm SoC for Noise-Robust Speech and NLP Edge AI Inference With Bayesian Sound Source Separation and Attention-Based DNNs

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    The proliferation of personal artificial intelligence (AI) -assistant technologies with speech-based conversational AI interfaces is driving the exponential growth in the consumer Internet of Things (IoT) market. As these technologies are being applied to keyword spotting (KWS), automatic speech recognition (ASR), natural language processing (NLP), and text-to-speech (TTS) applications, it is of paramount importance that they provide uncompromising performance for context learning in long sequences, which is a key benefit of the attention mechanism, and that they work seamlessly in polyphonic environments. In this work, we present a 25-mm 2^2 system-on-chip (SoC) in 16-nm FinFET technology, codenamed SM6, which executes end-to-end speech-enhancing attention-based ASR and NLP workloads. The SoC includes: 1) FlexASR, a highly reconfigurable NLP inference processor optimized for whole-model acceleration of bidirectional attention-based sequence-to-sequence (seq2seq) deep neural networks (DNNs); 2) a Markov random field source separation engine (MSSE), a probabilistic graphical model accelerator for unsupervised inference via Gibbs sampling, used for sound source separation; 3) a dual-core Arm Cortex A53 CPU cluster, which provides on-demand single Instruction/multiple data (SIMD) fast fourier transform (FFT) processing and performs various application logic (e.g., expectation–maximization (EM) algorithm and 8-bit floating-point (FP8) quantization); and 4) an always-on M0 subsystem for audio detection and power management. Measurement results demonstrate the efficiency ranges of 2.6–7.8 TFLOPs/W and 4.33–17.6 Gsamples/s/W for FlexASR and MSSE, respectively; MSSE denoising performance allowing 6 ×\times smaller ASR model to be stored on-chip with negligible accuracy loss; and 2.24-mJ energy consumption while achieving real-time throughput, end-to-end, and per-frame ASR latencies of 18 ms

    Enhancement of low-mass dileptons in heavy-ion collisions

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    Using a relativistic transport model for the expansion stage of S+Au collisions at 200 GeV/nucleon, we show that the recently observed enhancement of low-mass dileptons by the CERES collaboration can be explained by the decrease of vector meson masses in hot and dense hadronic matter.Comment: 12 pages, RevTeX, 3 figures available from [email protected]

    Compressive stenosis of the left hepatic vein as a pathogenesis of postresectional liver failure: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Postresectional liver failure (PLF) is a devastating and fatal complication of major hepatic resection, and we do not have a full understanding of the pathogenic mechanisms involved. No reliable treatment other than liver transplantation currently exists for PLF.</p> <p>Case presentation</p> <p>A 46-year-old Japanese man experienced PLF after an extended right hepatectomy for liver malignancy. Seven months after surgery, the patient's Model for End-Stage Liver Disease (MELD) score had reached 23. Doppler ultrasound study and three-dimensional computed tomography images showed a stenosed left hepatic vein compressed by surrounding hypertrophied hepatic parenchyma. Transluminal balloon angioplasty and stent placement therapy were conducted eight months after surgery. The pressure gradient between the hepatic vein and right atrium decreased from 13 to 3 mmHg after stent placement. Thereafter, the patient recovered.</p> <p>Conclusion</p> <p>Hepatic venous compression by surrounding hypertrophied hepatic parenchyma might, at least in part, be associated with the occurrence of PLF. Surgeons should bear this possibility in mind when confronted with cases of PLF, as early diagnosis and stent placement improves patients' chances of recovery.</p

    Formation of superdense hadronic matter in high energy heavy-ion collisions

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    We present the detail of a newly developed relativistic transport model (ART 1.0) for high energy heavy-ion collisions. Using this model, we first study the general collision dynamics between heavy ions at the AGS energies. We then show that in central collisions there exists a large volume of sufficiently long-lived superdense hadronic matter whose local baryon and energy densities exceed the critical densities for the hadronic matter to quark-gluon plasma transition. The size and lifetime of this matter are found to depend strongly on the equation of state. We also investigate the degree and time scale of thermalization as well as the radial flow during the expansion of the superdense hadronic matter. The flow velocity profile and the temperature of the hadronic matter at freeze-out are extracted. The transverse momentum and rapidity distributions of protons, pions and kaons calculated with and without the mean field are compared with each other and also with the preliminary data from the E866/E802 collaboration to search for experimental observables that are sensitive to the equation of state. It is found that these inclusive, single particle observables depend weakly on the equation of state. The difference between results obtained with and without the nuclear mean field is only about 20\%. The baryon transverse collective flow in the reaction plane is also analyzed. It is shown that both the flow parameter and the strength of the ``bounce-off'' effect are very sensitive to the equation of state. In particular, a soft equation of state with a compressibility of 200 MeV results in an increase of the flow parameter by a factor of 2.5 compared to the cascade case without the mean field. This large effect makes it possible to distinguish the predictions from different theoretical models and to detect the signaturesComment: 55 pages, latex, + 39 figures available upon reques

    Photon Rates for Heavy-Ion Collisions from Hidden Local Symmetry

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    We study photon production from the hidden local symmetry approach that includes pions, rho and a1 mesons and compute the corresponding photon emission rates from a hadronic gas in thermal equilibrium. Together with experimental radiative decay widths of the background, these rates are used in a relativistic transport model to calculate single photon spectra in heavy-ion collisions at SPS energies. We then employ this effective theory to test three scenarios for the chiral phase transition in high-temperature nuclear matter including decreasing vector meson masses. Although all calculations respect the upper bound set by the WA80 Collaboration, we find the scenarios could be distinguished with more detailed data.Comment: 12 pages, 12 Postscript figures; discussion of thermal equilibrium rates expanded, minor corrections to text and graph

    Relativistic quantum transport theory of hadronic matter: the coupled nucleon, delta and pion system

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    We derive the relativistic quantum transport equation for the pion distribution function based on an effective Lagrangian of the QHD-II model. The closed time-path Green's function technique, the semi-classical, quasi-particle and Born approximation are employed in the derivation. Both the mean field and collision term are derived from the same Lagrangian and presented analytically. The dynamical equation for the pions is consistent with that for the nucleons and deltas which we developed before. Thus, we obtain a relativistic transport model which describes the hadronic matter with NN, Δ\Delta and π\pi degrees of freedom simultaneously. Within this approach, we investigate the medium effects on the pion dispersion relation as well as the pion absorption and pion production channels in cold nuclear matter. In contrast to the results of the non-relativistic model, the pion dispersion relation becomes harder at low momenta and softer at high momenta as compared to the free one, which is mainly caused by the relativistic kinetics. The theoretically predicted free πN→Δ\pi N \to \Delta cross section is in agreement with the experimental data. Medium effects on the πN→Δ\pi N \to \Delta cross section and momentum-dependent Δ\Delta-decay width are shown to be substantial.Comment: 66 pages, Latex, 12 PostScript figures included; replaced by the revised version, to appear in Phys. Rev.

    Role of baryonic resonances in the dilepton emission in nucleon-nucleon collisions

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    Within an effective Lagrangian model, we present calculations for cross sections of the dilepton production in proton-proton and proton-neutron collisions at laboratory kinetic energies in 1-5 GeV range. Production amplitudes include contributions from the nucleon-nucleon bremsstrahlung as well as from the mechanism of excitation, propagation, and radiative decay of Delta(1232) and N*(1520) intermediate baryonic resonances. It is found that the delta isobar terms dominate the cross sections in the entire considered beam energy range. Our calculations are able to explain the data of the DLS collaboration on the dilepton production in proton-proton collisions for beam energies below 1.3 GeV. However, for incident energies higher than this the inclusion of contributions from other dilepton sources like Dalitz decay of pi0 and eta mesons, and direct decay of rho and omega mesons is necessary to describe the data.Comment: 22 pages, 7 figures, more details of the calculations added, version to appear in Phys. Rev

    e^+e^- Pair Production from Îł\gamma A Reactions

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    We present a calculation of e^+e^- production in ÎłA\gamma A reactions at MAMI and TJNAF energies within a semi-classical BUU transport model. Dilepton invariant mass spectra for Îł\gammaC, Îł\gammaCa and Îł\gammaPb are calculated at 0.8, 1.5 and 2.2 GeV. We focus on observable effects of medium modifications of the ρ\rho and ω\omega mesons. The in-medium widths of these mesons are taken into account in a dynamical, consistent way. We discuss the transport theoretical treatment of broad resonances.Comment: 42 pages including 16 figure

    Design and testing of hydrophobic core/hydrophilic shell nano/micro particles for drug-eluting stent coating

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    In this study, we designed a novel drug-eluting coating for vascular implants consisting of a core coating of the anti-proliferative drug docetaxel (DTX) and a shell coating of the platelet glycoprotein IIb/IIIa receptor monoclonal antibody SZ-21. The core/shell structure was sprayed onto the surface of 316L stainless steel stents using a coaxial electrospray process with the aim of creating a coating that exhibited a differential release of the two drugs. The prepared stents displayed a uniform coating consisting of nano/micro particles. In vitro drug release experiments were performed, and we demonstrated that a biphasic mathematical model was capable of capturing the data, indicating that the release of the two drugs conformed to a diffusion-controlled release system. We demonstrated that our coating was capable of inhibiting the adhesion and activation of platelets, as well as the proliferation and migration of smooth muscle cells (SMCs), indicating its good biocompatibility and anti-proliferation qualities. In an in vivo porcine coronary artery model, the SZ-21/DTX drug-loaded hydrophobic core/hydrophilic shell particle coating stents were observed to promote re-endothelialization and inhibit neointimal hyperplasia. This core/shell particle-coated stent may serve as part of a new strategy for the differential release of different functional drugs to sequentially target thrombosis and in-stent restenosis during the vascular repair process and ensure rapid re-endothelialization in the field of cardiovascular disease
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