1,122 research outputs found

    The Hidden Hydroxide in BaNiO3 Single Crystals Grown from a KOH Flux

    Full text link
    Hexagonal oxide perovskites with one-dimensional chains of face-sharing MO6 octahedra are of enduring interest. Specifically, the hexagonal perovskite BaNiO3, prepared via non-ceramic approaches, acts as a highly functional catalyst for the oxygen-evolution reaction (OER) in alkaline media, with numerous studies focusing on this behavior, while its fundamental structural and physical properties have been somewhat overlooked. The current work is intiated by the observation of contrasting magnetic properties of BaNiO3 synthesized via KOH flux growth and high O2 pressure ceramic synthesis. To shed light on this difference, we have performed a series of rigorous analyses and found that the KOH flux-grown crystals made in open-air are actually a wet form of BaNiO3 that can be dried upon annealing in O2 flow but will then slowly degrade if stored under a condition where the O2 partial pressure is not high enough. Therefore, the present work not only provides insightful information to unveil a previously unknown aspect of the OER catalyst BaNiO3, but also rings a bell that the hidden hydroxide principle described here may also be applied to other hexagonal perovskite oxides prepared in wet conditions.Comment: 21 pages, 6 figure

    Immobilization of enzyme and antibody on ALD-HfO2-EIS structure by NH3 plasma treatment

    Get PDF
    Thin hafnium oxide layers deposited by an atomic layer deposition system were investigated as the sensing membrane of the electrolyte-insulator-semiconductor structure. Moreover, a post-remote NH3 plasma treatment was proposed to replace the complicated silanization procedure for enzyme immobilization. Compared to conventional methods using chemical procedures, remote NH3 plasma treatment reduces the processing steps and time. The results exhibited that urea and antigen can be successfully detected, which indicated that the immobilization process is correct

    Serotonin receptor HTR6-mediated mTORC1 signaling regulates dietary restriction-induced memory enhancement

    Get PDF
    Dietary restriction (DR; sometimes called calorie restriction) has profound beneficial effects on physiological, psychological, and behavioral outcomes in animals and in humans. We have explored the molecular mechanism of DR-induced memory enhancement and demonstrate that dietary tryptophan-a precursor amino acid for serotonin biosynthesis in the brain-and serotonin receptor 5-hydroxytryptamine receptor 6 (HTR6) are crucial in mediating this process. We show that HTR6 inactivation diminishes DR-induced neurological alterations, including reduced dendritic complexity, increased spine density, and enhanced long-term potentiation (LTP) in hippocampal neurons. Moreover, we find that HTR6-mediated mechanistic target of rapamycin complex 1 (mTORC1) signaling is involved in DR-induced memory improvement. Our results suggest that the HTR6-mediated mTORC1 pathway may function as a nutrient sensor in hippocampal neurons to couple memory performance to dietary intake

    Ultrasound measurement of vastus lateralis and vastus medialis muscle parameters to identify chronic thyrotoxic myopathy

    Get PDF
    Introduction: Chronic thyrotoxic myopathy (CTM) is a common, easily neglected complication of hyperthyroidism. There are currently no standard diagnostic criteria for CTM, and the ultrasonic characteristics of CTM-affected skeletal muscle remain unclear. Herein, we aimed to evaluate hyperthyroid patients for CTM by ultrasound and identify ultrasonic muscle parameter cutoffs for CTM diagnosis. Materials and methods: Each participant underwent ultrasonography. The original (muscle thickness (MT), pennation angle (PA), and cross-sectional area (CSA)) and corrected (MT/height (HT), MT/body mass index (BMI), CSA/HT, and CSA/BMI) parameters of the vastus lateralis and vastus medialis (VM) were evaluated. The diagnostic effectiveness of ultrasound for predicting CTM was determined using receiver operating characteristic (ROC) curve analysis. Our study included 203 participants: 67 CTM patients (18 males, 49 females), 67 non-CTM patients (28 males, 39 females) and 69 healthy controls (20 males, 49 females). Results: The CTM group had lower muscular ultrasonic and anthropometric parameters, higher thyroid hormone and thyroid-stimulating hormone receptor antibody (TRAb) levels, and a longer duration of hyperthyroidism than the non-CTM group (P < 0.05). The VM-PA, VM-CSA, VM-CSA/HT, and VM-CSA/BMI were lower in females than in males (P < 0.05). Free thyroxine (FT4) and TRAb both showed significant negative correlations with VM-MT, VM-MT/HT, VM-CSA, and VM-CSA/HT (P < 0.05). VM-MT/BMI and VM-CSA/HT, respectively, best predicted male and female CTM (AUC = 0.84, 0.85; cutoff ≤ 0.07, < 4.01). Conclusion: Ultrasound measurement of muscular parameters, especially in the VM, is a valid and feasible way of diagnosing and characterizing possible CTM in hyperthyroidism

    An outcome analysis of self-expandable metallic stents in central airway obstruction: a cohort study

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Self-expandable metallic stents (SEMSs) have provided satisfactory management of central airway obstruction. However, the long-term benefits and complications of this management modality in patients with benign and malignant obstructing lesions after SEMS placement are unclear. We performed this cohort study to analyze the outcomes of Ultraflex SEMSs in patients with tracheobronchial diseases.</p> <p>Methods</p> <p>Of 149 patients, 72 with benign and 77 with malignant tracheobronchial disease received 211 SEMSs (benign, 116; malignant, 95) and were retrospectively reviewed in a tertiary hospital.</p> <p>Results</p> <p>The baseline characteristics of patients who received SEMS implantation for benign conditions and those who underwent implantation for malignant conditions were significantly different. These characteristics included age (mean, 63.9 vs. 58; <it>p </it>< 0.01), gender (male, 62% vs. 90%; <it>p </it>< 0.0001), smoking (47% vs. 85%; <it>p </it>< 0.0001), forced expiratory volume in 1 second (mean, 0.9 vs. 1.47 L/s; <it>p </it>< 0.0001), follow-up days after SEMS implantation (median; 429 vs. 57; <it>p </it>< 0.0001), and use of covered SEMS (36.2% vs. 94.7%; <it>p </it>< 0.0001). Symptoms improved more after SEMS implantation in patients with benign conditions than in those with malignant conditions (76.7% vs. 51.6%; <it>p </it>< 0.0001). The overall complication rate after SEMS implantation in patients with benign conditions was higher than that in patients with malignancy (42.2% vs. 21.1%; <it>p </it>= 0.001). Successful management of SEMS migration, granulation tissue formation, and SEMS fracture occurred in 100%, 81.25%, and 85% of patients, respectively.</p> <p>Conclusions</p> <p>Patients who received SEMS implantation owing to benign conditions had worse lung function and were older than those who received SEMS for malignancies. There was higher complication rate in patients with benign conditions after a longer follow-up period owing to the nature of the underlying diseases.</p
    corecore