58 research outputs found

    High-flow nasal cannula for respiratory failure in adult patients

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    The high-flow nasal cannula (HFNC) has been recently used in several clinical settings for oxygenation in adults. In particular, the advantages of HFNC compared with low-flow oxygen systems or non-invasive ventilation include enhanced comfort, increased humidification of secretions to facilitate expectoration, washout of nasopharyngeal dead space to improve the efficiency of ventilation, provision of a small positive end-inspiratory pressure effect, and fixed and rapid delivery of an accurate fraction of inspired oxygen (FiO2) by minimizing the entrainment of room air. HFNC has been successfully used in critically ill patients with several conditions, such as hypoxemic respiratory failure, hypercapneic respiratory failure (exacerbation of chronic obstructive lung disease), post-extubation respiratory failure, pre-intubation oxygenation, and others. However, the indications are not absolute, and much of the proven benefit remains subjective and physiologic. This review discusses the practical application and clinical uses of HFNC in adults, including its unique respiratory physiologic effects, device settings, and clinical indications

    Conceptual Design and Analysis of No-Insulation High-Temperature Superconductor Tubular Wave Energy Converter

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    So far, a number of wave energy converters (WEC) have been proposed to increase efficiency and economic feasibility. Particularly, tubular WEC with permanent magnets and coil winding packs is mostly used to convert the wave energy. Due to the demand for high magnetic flux density in WEC, research has been conducted on high-temperature superconductors (HTS) WEC. In this paper, the conceptual design of no-insulation (NI) HTS tubular WEC and its optimization process are proposed. Using NI technology, it has become possible to design WEC with high volumetric efficiency and cost-effectiveness. Furthermore, the design is analyzed in the aspect of electromagnetism, mechanical force, and cryogen. The performance of the proposed WEC is evaluated as a response to various waveforms and their amplitudes. A rectifying circuit of WEC connected in parallel with load resistance is used for the output power study

    Shape optimization of superconducting transmon qubit for low surface dielectric loss

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    Surface dielectric loss of superconducting transmon qubit is believed as one of the dominant sources of decoherence. Reducing surface dielectric loss of superconducting qubit is known to be a great challenge for achieving high quality factor and a long relaxation time (T1T_{1}). Changing the geometry of capacitor pads and junction wire of transmon qubit makes it possible to engineer the surface dielectric loss. In this paper, we present the shape optimization approach for reducing Surface dielectric loss in transmon qubit. The capacitor pad and junction wire of the transmon qubit are shaped as spline curves and optimized through the combination of the finite-element method and global optimization algorithm. Then, we compared the surface participation ratio, which represents the portion of electric energy stored in each dielectric layer and proportional to two-level system (TLS) loss, of optimized structure and existing geometries to show the effectiveness of our approach. The result suggests that the participation ratio of capacitor pad, and junction wire can be reduced by 16% and 26% compared to previous designs through shape optimization, while overall footprint and anharmonicity maintain acceptable value. As a result, the TLS-limited quality factor and corresponding T1T_{1} were increased by approximately 21.6%

    The Impact of Aspirin Intake on Lactate Dehydrogenase, Arterial Stiffness, and Oxidative Stress During High-Intensity Exercise: A Pilot Study

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    Aspirin is a common nonsteroidal anti-inflammatory drug used to reduce fever, pain, and inflammation. However, aspirin\u27s anti-inflammatory properties may also prevent increased levels of blood lactate dehydrogenase, vascular arterial stiffness and oxidative stress induced by high-intensity exercise. The purpose of this study was to investigate the effects of 4 weeks of aspirin supplementation on lactate dehydrogenase activity, lactate, arterial stiffness, and antioxidant capacity during high-intensity exercise in Taekwondo athletes. Participants were randomly divided into two groups: aspirin supplementation (n = 10) and placebo-control (n = 10). Blood levels of lactate dehydrogenase (LDH) enzyme activity and lactate were assessed to examine muscle damage and carotid-to-radial pulse wave velocity and the augmentation index were measured to examine arterial stiffness. Blood levels of superoxide dismutase, malondialdehyde, and glutathione peroxidase were assessed to determine antioxidant capacity and levels of oxidative stress. There were significant group × time interactions for enzyme activity of LDH (Δ-60 ± 24.36 U/L) and carotid-to-radial pulse wave velocity (Δ-1.33 ± 0.54 m/s), which significantly decreased (p \u3c 0.05) following aspirin supplementation compared to placebo-control. Superoxide dismutase (Δ359 ± 110 U/gHb) and glutathione peroxidase (Δ28.2 ± 10.1 U/gHb) significantly decreased while malondialdehyde (0Δ3.0 ± 0.1 mmol/mL) significantly increased (p \u3c 0.05) in the placebo-control group compared to the supplementation group. However, there were no changes in lactate concentration levels or augmentation index. These results reveal that low-dose aspirin supplementation would be a useful supplementation therapy to prevent high-intensity exercise training-induced increases in oxidative damage, inflammation, skeletal muscle fatigue, and arterial stiffness in elite Taekwondo athletes

    Taekwondo training reduces blood catecholamine levels and arterial stiffness in postmenopausal women with stage-2 hypertension: randomized clinical trial

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    Objective: Menopause is associated with a progressive impairment of vascular function and muscular strength in women. Accordingly, the purpose of this study was to determine if Taekwondo training could improve blood catecholamine levels, arterial stiffness, blood pressure (BP) and skeletal muscle strength in postmenopausal women with stage-2 hypertension. Methods: 20 postmenopausal women (70 ± 4 years old) with stage-2 hypertension were randomly assigned to a 1) Taekwondo training (TT; n = 10) or 2) Control (CON; n = 10) group. Taekwondo training was performed for 60 minutes/day, 3 days/week for 12-weeks. Results: There were significant (P \u3c 0.05) group by time interactions for resting epinephrine (EP) and norepinephrine (NE) levels, with EP decreasing in the TT group and NE increasing in the CON group. Additionally, brachial-ankle pulse wave velocity, resting heart rate, and BP were significantly decreased, while hand grip and leg strength were significantly increased in the TT group compared to CON group. Conclusion: These results suggest that Taekwondo training can be a novel and beneficial mode of exercise for improving cardiovascular function and muscular strength in this population. Abbreviations: TT: Taekwondo training group; CON: control group; EP: epinephrine; NE: norepinephrine; ANS: autonomic nervous system; SNS: sympathetic nervous system; baPWV: brachial-ankle pulse wave velocit

    Bleeding complications associated with the molecular adsorbent recirculating system: a retrospective study

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    Background The molecular adsorbent recirculating system (MARS) is a hepatic replacement system that supports excretory liver function in patients with liver failure. However, since MARS has been employed in our hospital, bleeding complications have occurred in many patients during or after MARS. The objective of this study was to determine how MARS affects coagulopathy and identify specific factors associated with bleeding complications. Methods We retrospectively analyzed data from 17 patients undergoing a total of 41 MARS sessions. Complete blood count, coagulation profiles, and blood chemistry values were compared before and after MARS. To identify pre-MARS factors associated with increased bleeding after MARS, we divided patients into bleeder and non-bleeder groups and compared their pre-MARS laboratory values. Results MARS significantly reduced bilirubin and creatinine levels. MARS also increased prothrombin time and reduced platelet and fibrinogen, thus negatively impacting coagulation. Pre-MARS hemoglobin was significantly lower in the bleeder group than in the non-bleeder group (P=0.015). When comparing the upper and lower 33% of MARS sessions based on the hemoglobin reduction rate, hemoglobin reduction was significantly greater in MARS sessions involving patients with low pre-MARS international normalized ratio of prothrombin time (PT-INR) and factor V (P=0.038 and P=0.023, respectively). Conclusions MARS could appears to alter coagulation-related factors such as factor V and increase the risk of bleeding complications particularly in patient with low hemoglobin. However, individual differences among patients were large, and various factors, such as low hemoglobin, PT-INR, and factor V levels, appear to be involved

    Full-Field Subwavelength Imaging Using a Scattering Superlens

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    Light-matter interaction gives optical microscopes tremendous versatility compared with other imaging methods such as electron microscopes, scanning probe microscopes, or x-ray scattering where there are various limitations on sample preparation and where the methods are inapplicable to bioimaging with live cells. However, this comes at the expense of a limited resolution due to the diffraction limit. Here, we demonstrate a novel method utilizing elastic scattering from disordered nanoparticles to achieve subdiffraction limited imaging. The measured far-field speckle fields can be used to reconstruct the subwavelength details of the target by time reversal, which allows full-field dynamic super-resolution imaging. The fabrication of the scattering superlens is extremely simple and the method has no restrictions on the wavelength of light that is usedclos

    Protective effects of protocatechuic acid against cisplatin-induced renal damage in rats

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    The protective effects of an extract from bitter melon (. Momordica charantia, Cucurbitaceae) against oxidative stress was previously reported and found that protocatechuic acid (PCA) was one of the major phenolic constituents in the extract. The renoprotective effect of PCA from bitter melon was investigated in the present study. In the LLC-PK1 cellular model, the decline in cells viabilities induced by oxidative stress, such as that induced by sodium nitroprusside, pyrogallol, and SIN-1, was significantly and dose-dependently inhibited by PCA. In the in vivo model, the cisplatin-treated rats showed increased plasma levels of creatinine, decreased creatinine clearance, and increased urine protein levels. However, these parameters related to renal dysfunction were markedly attenuated by PCA treatment. Administration of PCA resulted in remarkable improvement in the histological appearance and reduction in tubular cell damage in the cisplatin-treated rat kidneys. Moreover, the elevated levels of pro-caspase-3 induced by cisplatin in rat kidneys were down-regulated by PCA co-treatment. These results suggest that PCA has protective activity against anticancer drug-induced oxidative nephrotoxicity

    Analysis of Noise Coupling From a Power Distribution Network to Signal Traces in High-Speed Multilayer Printed Circuit Boards

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    As layout density increases in highly integrated multilayer printed circuit boards (PCBs), the noise that exists in the power distribution network (PDN) is increasingly coupled to the signal traces, and precise modeling to describe the coupling phenomenon becomes necessary. This paper presents a model to describe noise coupling between the power/ground planes and signal traces in multilayer systems. An analytical model for the coupling has been successfully derived, and the coupling mechanism was rigorously analyzed and clarified. Wave equations for a signal trace with power/ground noise were solved by imposing boundary conditions. Measurements in both the frequency and time domains have been conducted to confirm the validity of the proposed model
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