36 research outputs found

    Study on the continuous phase evolution and physical properties of gas-atomized high-entropy alloy powders

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    In this study, AlCoCrFeNi high entropy alloy (HEA) powders were fabricated by gas atomization process, and the effects of annealing heat treatment on phase evolution and mechanical properties were investigated. The as-atomized powders have pure BCC phase with a spherical shape and equal composition distribution, and then the FCC and sigma phase sequentially generated after annealing. The mechanical property such as hardness was evidently enhanced, which was caused by precipitation hardening effect. After the raw powders were annealed at 600 °C, the FCC (Al-Ni) phase began to precipitate, the its phase intensity raised with the annealing temperature. Then, the sigma phase (Fe-Cr) formed as the annealing temperature reached 800 °C. Both mechanical properties and lattice constant were influenced by heating effect. According to the results, the lattice became loose with the increasing temperature. In summary, the mechanical properties and phase constitutions of gas-atomized AlCoCrFeNi HEA powders can be adjusted via annealing process, resulting in precipitation hardening effect

    Spatiotemporal impact of COVID-19 on Taiwan air quality in the absence of a lockdown: Influence of urban public transportation use and meteorological conditions

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    The unprecedented outbreak of COVID-19 significantly improved the atmospheric environment for lockdown-imposed regions; however, scant evidence exists on its impacts on regions without lockdown. A novel research framework is proposed to evaluate the long-term monthly spatiotemporal impact of COVID-19 on Taiwan air quality through different statistical analyses, including geostatistical analysis, change detection analysis and identification of nonattainment pollutant occurrence between the average mean air pollutant concentrations from 2018–2019 and 2020, considering both meteorological and public transportation impacts. Contrary to lockdown-imposed regions, insignificant or worsened air quality conditions were observed at the beginning of COVID-19, but a delayed improvement occurred after April in Taiwan. The annual mean concentrations of PM10, PM2.5, SO2, NO2, CO and O3 in 2020 were reduced by 24%, 18%, 15%, 9.6%, 7.4% and 1.3%, respectively (relative to 2018–2019), and the overall occurrence frequency of nonattainment air pollutants declined by over 30%. Backward stepwise regression models for each air pollutant were successfully constructed utilizing 12 meteorological parameters (R2 > 0.8 except for SO2) to simulate the meteorological normalized business-as-usual concentration. The hybrid single-particle Lagrangian integrated trajectory (HYSPLIT) model simulated the fate of air pollutants (e.g., local emissions or transboundary pollution) for anomalous months. The changes in different public transportation usage volumes (e.g., roadway, railway, air, and waterway) moderately reduced air pollution, particularly CO and NO2. Reduced public transportation use had a more significant impact than meteorology on air quality improvement in Taiwan, highlighting the importance of proper public transportation management for air pollution control and paving a new path for sustainable air quality management even in the absence of a lockdown

    The trans-ancestral genomic architecture of glycemic traits

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    Glycemic traits are used to diagnose and monitor type 2 diabetes and cardiometabolic health. To date, most genetic studies of glycemic traits have focused on individuals of European ancestry. Here we aggregated genome-wide association studies comprising up to 281,416 individuals without diabetes (30% non-European ancestry) for whom fasting glucose, 2-h glucose after an oral glucose challenge, glycated hemoglobin and fasting insulin data were available. Trans-ancestry and single-ancestry meta-analyses identified 242 loci (99 novel; P < 5 x 10(-8)), 80% of which had no significant evidence of between-ancestry heterogeneity. Analyses restricted to individuals of European ancestry with equivalent sample size would have led to 24 fewer new loci. Compared with single-ancestry analyses, equivalent-sized trans-ancestry fine-mapping reduced the number of estimated variants in 99% credible sets by a median of 37.5%. Genomic-feature, gene-expression and gene-set analyses revealed distinct biological signatures for each trait, highlighting different underlying biological pathways. Our results increase our understanding of diabetes pathophysiology by using trans-ancestry studies for improved power and resolution. A trans-ancestry meta-analysis of GWAS of glycemic traits in up to 281,416 individuals identifies 99 novel loci, of which one quarter was found due to the multi-ancestry approach, which also improves fine-mapping of credible variant sets.Peer reviewe

    Effect of Polarization on the Correlation and Capacity of Indoor MIMO Channels

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    We describe a simple multiple-input/multiple-output (MIMO) channel measurement system for acquiring indoor MIMO channel responses. Four configurations of the polarization diversity antenna, referred to as VVV, YYH, YVY and VHH, were studied in terms of the capacity of indoor MIMO systems. Measurements were taken for a 3 × 3 MIMO system in the 2.4 GHz band. In addition, the channel capacity, singular-value decomposition, and correlation coefficient were used to explain the effects of various polarization schemes on MIMO fading channels. We also propose an analysis method for polarization channel capacity; this method includes the normalization of the received power and polarization effect for different polarization schemes. The validation of the model is based upon data collected in both light-of-sight (LOS) and non-light-of-sight (NLOS) environments. From the numerical simulation results, the proposed analysis method was close to measurements made in an indoor environment

    Chronic kidney disease, preoperative use of antispasmodics and lower resected prostate volume ratios are risk factors for postoperative use of adrenergic Alpha-blockers and antispasmodics.

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    ObjectivesTransurethral resection of prostate (TURP) and laser prostate surgery are common surgeries for benign prostate hyperplasia (BPH). We conducted an investigation using hospital database to evaluate the clinical factors associated with post-operative usage of alpha-blockers and antispasmodics.MethodsThis study was conducted using retrospective clinical data from the hospital database, which contained newly diagnosed BPH patients between January 2007 and December 2012 who subsequently received prostate surgery. The study end-point was the use of alpha-blockers or antispasmodics for at least 3 months duration after 1 month of surgery. The exclusion criteria was prostate cancer diagnosed before or after the surgery, recent transurethral surgeries, history of open prostatectomy, and history of spinal cord injury. Clinical parameters, including age, body mass index, preoperative prostate specific antigen value, comorbidities, preoperative usage of alpha-blockers, anstispasmodics and 5-alpha reductase inhibitors, surgical methods, resected prostate volume ratios, and preoperative urine flow test results, were evaluated.ResultsA total of 250 patients receiving prostate surgery in the database and confirmed pathologically benign were included. There was significant association between chronic kidney disease (CKD) and the usage of alpha-blockers after prostate surgery (OR = 1.93, 95% CI 1.04-3.56, p = 0.036). Postoperative antispasmodics usage was significantly associated with preoperative usage of antispasmodics (OR = 2.33, 95% CI 1.02-5.36, p = 0.046) and resected prostate volume ratio (OR = 0.12, 95% CI 0.02-0.63, p = 0.013).ConclusionsBPH patients with underlying CKD were more likely to require alpha-blockers after surgery. In the meantime, BPH patients who required antispasmodics before surgery and who received lower prostate volume resection ratio were more liable to antispasmodics after prostate surgery

    Chronic kidney disease, preoperative use of antispasmodics and lower resected prostate volume ratios are risk factors for postoperative use of adrenergic Alpha-blockers and antispasmodics

    No full text
    Objectives Transurethral resection of prostate (TURP) and laser prostate surgery are common surgeries for benign prostate hyperplasia (BPH). We conducted an investigation using hospital database to evaluate the clinical factors associated with post-operative usage of alpha-blockers and antispasmodics. Methods This study was conducted using retrospective clinical data from the hospital database, which contained newly diagnosed BPH patients between January 2007 and December 2012 who subsequently received prostate surgery. The study end-point was the use of alpha-blockers or antispasmodics for at least 3 months duration after 1 month of surgery. The exclusion criteria was prostate cancer diagnosed before or after the surgery, recent transurethral surgeries, history of open prostatectomy, and history of spinal cord injury. Clinical parameters, including age, body mass index, preoperative prostate specific antigen value, comorbidities, preoperative usage of alpha-blockers, anstispasmodics and 5-alpha reductase inhibitors, surgical methods, resected prostate volume ratios, and preoperative urine flow test results, were evaluated. Results A total of 250 patients receiving prostate surgery in the database and confirmed pathologically benign were included. There was significant association between chronic kidney disease (CKD) and the usage of alpha-blockers after prostate surgery (OR = 1.93, 95% CI 1.04–3.56, p = 0.036). Postoperative antispasmodics usage was significantly associated with preoperative usage of antispasmodics (OR = 2.33, 95% CI 1.02–5.36, p = 0.046) and resected prostate volume ratio (OR = 0.12, 95% CI 0.02–0.63, p = 0.013). Conclusions BPH patients with underlying CKD were more likely to require alpha-blockers after surgery. In the meantime, BPH patients who required antispasmodics before surgery and who received lower prostate volume resection ratio were more liable to antispasmodics after prostate surgery

    Astaxanthin Ameliorates Ischemic-Hypoxic-Induced Neurotrophin Receptor p75 Upregulation in the Endothelial Cells of Neonatal Mouse Brains

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    Ischemic stroke is a leading cause of human death in present times. Two phases of pathological impact occur during an ischemic stroke, namely, ischemia and reperfusion. Both periods include individual characteristic effects on cell injury and apoptosis. Moreover, these conditions can cause severe cell defects and harm the blood-brain barrier (BBB). Also, the BBB components are the major targets in ischemia-reperfusion injury. The BBB owes its enhanced protective roles to capillary endothelial cells, which maintain BBB permeability. One of the nerve growth factor (NGF) receptors initiating cell signaling, once activated, is the p75 neurotrophin receptor (p75NTR). This receptor is involved in both the survival and apoptosis of neurons. Although many studies have attempted to explain the role of p75NTR in neurons, the mechanisms in endothelial cells remain unclear. Endothelial cells are the first cells to encounter p75NTR stimuli. In this study, we found the upregulated p75NTR expression and reductive expression of tight junction proteins after in vivo and in vitro ischemia-reperfusion injury. Moreover, astaxanthin (AXT), an antioxidant drug, was utilized and was found to reduce p75NTR expression and the number of apoptotic cells. This study verified that p75NTR plays a prominent role in endothelial cell death and provides a novel downstream target for AXT

    Incorporating VR-RENDER Fusion Software in Robot-Assisted Partial Prostatectomy: The First Case Report

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    Currently, the active surveillance of men with favorable intermediate-risk localized prostate cancer (PCa) is a longstanding controversy, in terms of their oncological outcomes, and radical prostatectomy would constitute a similar concern of overtreatment, regarding its functional outcomes. Thus, focal therapy could be considered in men belonging to favorable intermediate-risk group. Among all focal therapies, high-intensity focused ultrasound (HIFU) was the most studied methodology in clinical trials. Although HIFU provided better functional outcomes than radical prostatecomy, the oncological outcomes were inferior in men with intermediate-risk localized PCa. Two articles have been published discussing the feasibility and clinical outcomes of robot-assisted partial prostatectomy (RAPP), and both the functional and oncological outcomes were superior than those with HIFU. However, the rate of positive surgical margins (PSMs) was reported as high in the literature. Here, we present a case of favorable intermediate-risk localized PCa with an isolated tumor at the anterior apex. After reconstructing a personal three-dimensional (3D) image, we utilized it in a 3D image-guided precise excise, followed by intraoperative frozen specimen review. We found that this method may present a resolution to the high PSM rate documented in the current literature regarding RAPP. This method merits further study with a well-designed prospective study

    Sacubitril/Valsartan in Patients With Heart Failure and Concomitant End‐Stage Kidney Disease

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    Background Heart failure with reduced ejection fraction (HFrEF) is a chronic disease with substantial mortality. Management of HFrEF has seen significant breakthrough after the launch of neprilysin inhibitor. The PARADIGM‐HF (Prospective Comparison of ARNI with ACEI to Determine Impacton Global Mortality and Morbidity in Heart Failure) trial showed that sacubitril/valsartan significantly reduces HFrEF mortality and the heart failure hospitalization rate. However, in patients with advanced kidney disease, who have the highest prevalence of heart failure, the efficacy and safety of sacubitril/valsartan remains uncertain. We aim to study the efficiency of sacubitril/valsartan in patients with end‐stage kidney disease. Methods and Results Heart function was screened by echocardiogram among all patients with end‐stage kidney disease in 2 hospitals. Patients with HFrEF received either sacubitril/valsartan or conventional treatment. Fifteen echocardiographic parameters were compared before and after treatment. After 1‐year sacubitril/valsartan treatment, parameters of systolic (left ventricular ejection fraction 31.3% to 45.1%, P<0.0001; left ventricular end‐systolic volume 95.7 to 70.1 mL, P=0.006; left ventricular internal diameter at end‐systole phase 47.2 to 40.1 mm, P=0.005), and diastolic (E/A ratio 1.3 to 0.8, P=0.009; E/Med e' ratio 25.3 to 18.8, P=0.010) function improved in patients with HFrEF and end‐stage kidney disease. These parameters were unchanged in the conventional treatment group. Serum potassium did not increase in the sacubitril/valsartan group. Conclusions Sacubitril/valsartan improves left ventricular systolic and diastolic function in patients with HFrEF and end‐stage kidney disease
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