12 research outputs found
Ex Situ Reconstruction-Shaped Ir/CoO/Perovskite Heterojunction for Boosted Water Oxidation Reaction
The oxygen evolution reaction (OER) is the performance-limiting step in the process of water splitting. In situ electrochemical conditioning could induce surface reconstruction of various OER electrocatalysts, forming reactive sites dynamically but at the expense of fast cation leaching. Therefore, achieving simultaneous improvement in catalytic activity and stability remains a significant challenge. Herein, we used a scalable cation deficiency-driven exsolution approach to ex situ reconstruct a homogeneous-doped cobaltate precursor into an Ir/CoO/perovskite heterojunction (SCI-350), which served as an active and stable OER electrode. The SCI-350 catalyst exhibited a low overpotential of 240 mV at 10 mA cm-2 in 1 M KOH and superior durability in practical electrolysis for over 150 h. The outstanding activity is preliminarily attributed to the exponentially enlarged electrochemical surface area for charge accumulation, increasing from 3.3 to 175.5 mF cm-2. Moreover, density functional theory calculations combined with advanced spectroscopy and 18O isotope-labeling experiments evidenced the tripled oxygen exchange kinetics, strengthened metal-oxygen hybridization, and engaged lattice oxygen oxidation for O-O coupling on SCI-350. This work presents a promising and feasible strategy for constructing highly active oxide OER electrocatalysts without sacrificing durability
Asthma Is a Risk Factor for Respiratory Exacerbations Without Increased Rate of Lung Function Decline:Five-Year Follow-up in Adult Smokers From the COPDGene Study
Trends of a decade in risk factors of patient delay among pulmonary tuberculosis patients during fast aging and urbanization - analysis of surveillance data from 2008 to 2017 in Wuhan, China
Abstract Background Tuberculosis (TB) is a leading infectious cause of morbidity and mortality worldwide. However, delay in health care seeking has remained unacceptably high. The aim of this study was to clarify the trend of patient delay and its associated risk factors during rapid aging and urbanization in Wuhan, China from 2008 to 2017. Methods A total of 63,720 TB patients registered at Wuhan TB Information Management System from January 2008 to December 2017 were included. Long patient delay (LPD) was defined as patient delay longer than 14 days. Independent associations of area and household identity with LPD, as well their interaction effect, were tested by logistic regression models. Results Among 63,720 pulmonary TB patients, 71.3% were males, the mean age was 45.5 ± 18.8 years. The median patient delay was 10 days (IQR, 3–28). A total of 26,360 (41.3%) patients delayed for more than 14 days. The proportion of LPD decreased from 44.8% in 2008 to 38.3% in 2017. Similar trends were observed in all the subgroups by gender, age and household, except for living area. The proportion of LPD decreased from 46.3 to 32.8% in patients living near downtown and increased from 43.2 to 45.2% in patients living far from downtown. Further interaction effect analysis showed that among patients living far from downtown, the risk of LPD for local patients increased with age, while decreased with age for migrant patients. Conclusion Although the overall LPD among pulmonary TB patients declined in the past decade, the extent of reduction varied in different subgroups. The elderly local and young migrant patients living far from downtown are the most vulnerable groups to LPD in Wuhan, China