Lead-free Na 0.5 K 0.5 NbO 3 (NKN) piezoelectric ceramics were fairly well densified at a relatively low temperature under atmospheric conditions. A relative density of 96%-99% can be achieved by either using high-energy attrition milling or adding 1 mol% oxide additives. It is suggested that ultra-fine starting powders by active milling or oxygen vacancies and even liquid phases from B-site oxide additives mainly lead to improved sintering. Not only were dielectric properties influenced by oxide additives, such as the Curie temperature (T c ) and dielectric loss (D), but also the ferroelectricity was modified. A relatively large remanent polarization was produced, ranging from 16 lC/cm 2 for pure NKN to 23 lC/cm 2 for ZnO-added NKN samples. The following dielectric and piezoelectric properties were obtained: relative permittivity e T 33 =e o 5 570-650, planar mode electromechanical coupling factor, k p 5 32%-44%, and piezoelectric strain constant, d 33 5 92-117 pC/N. J ournal

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Hypertension is proved to be associated with severity and mortality in coronavirus disease 2019 (COVID‐19). However, little is known about the effects of pre‐admission and/or in‐hospital antihypertension treatments on clinical outcomes. Thus, this study aimed to investigate the association between in‐hospital blood pressure (BP) control and COVID‐19–related outcomes and to compare the effects of different antihypertension treatments. This study included 2864 COVID‐19 patients and 1628 were hypertensive. Patients were grouped according to their BP during hospitalization and records of medication application. Patients with higher BP showed worse cardiac and renal functions and clinical outcomes. After adjustment, subjects with pre‐admission usage of renin‐angiotensin‐aldosterone system (RAAS) inhibitors (HR = 0.35, 95%CI 0.14‐0.86, P = .022) had a lower risk of adverse clinical outcomes, including death, acute respiratory distress syndrome, respiratory failure, septic shock, mechanical ventilation, and intensive care unit admission. Particularly, hypertension patients receiving RAAS inhibitor treatment either before (HR = 0.35, 95%CI 0.13‐0.97, P = .043) or after (HR = 0.18, 95%CI 0.04‐0.86, P = .031) admission showed a significantly lower risk of adverse clinical outcomes than those receiving application of other antihypertensive medicines. Furthermore, consecutive application of RAAS inhibitors in COVID‐19 patients with hypertension showed better clinical outcomes (HR = 0.10, 95%CI 0.01‐0.83, P = .033) than non‐RAAS inhibitors users. We revealed that COVID‐19 patients with poor BP control during hospitalization had worse clinical outcomes. Compared with other antihypertension medicines, RAAS inhibitors were beneficial for improving clinical outcomes in COVID‐19 patients with hypertension. Our findings provide direct evidence to support the administration of RAAS inhibitors to COVID‐19 patients with hypertension before and after admission.

Different amounts of silver (0.5–10 wt%) have been mixed with EIA X7R‐type ceramic powders based on barium titanate. The XRD analysis indicated that no phases other than BaTiO3 and silver were present in the doped ceramics; it further suggested that no reaction took place between BaTiO3 and silver during calcination and sintering. SEM observation showed that the silver particles presented island distribution in the BaTiO3 ceramic matrix. The densification and dielectric properties of the silver‐doped ceramics in disk form were investigated. A large amount of silver addition (>1 wt%) was found to improve the sintered density and dielectric properties. The temperature coefficient of capacitors of the ceramics doped with 10 wt% silver still met the X7R characteristics, and the dielectric constant of the ceramics at room temperature was >6000, which is the highest dielectric constant in the BaTiO3‐based X7R system.