A considerable amount of platinum (Pt) is required to ensure an adequate rate for the oxygen reduction reaction (ORR) in fuel cells and metal‐air batteries. Thus, the implementation of atomic Pt ...catalysts holds promise for minimizing the Pt content. In this contribution, atomic Pt sites with nitrogen (N) and phosphorus (P) co‐coordination on a carbon matrix (PtNPC) are conceptually predicted and experimentally developed to alter the d‐band center of Pt, thereby promoting the intrinsic ORR activity. PtNPC with a record‐low Pt content (≈0.026 wt %) consequently shows a benchmark‐comparable activity for ORR with an onset of 1.0 VRHE and half‐wave potential of 0.85 VRHE. It also features a high stability in 15 000‐cycle tests and a superior turnover frequency of 6.80 s−1 at 0.9 VRHE. Damjanovic kinetics analysis reveals a tuned ORR kinetics of PtNPC from a mixed 2/4‐electron to a predominately 4‐electron route. It is discovered that coordinated P species significantly shifts d‐band center of Pt atoms, accounting for the exceptional performance of PtNPC.
Phosphorus‐coordinated atomic Pt‐Nx sites are theoretically predicted and experimentally realized, offering enhanced kinetics for four‐electron electrochemical oxygen reduction. Exceptional activity is attributed to the tuning of the d‐band electron center via local coordination asymmetry. This chemistry provides an effective guideline for atomic Pt catalysts in batteries and fuel cells.
This study examines the role of artificial intelligence (AI) as a marketing strategy and explains its contribution to firms and the factors influencing their development. The study tests an empirical ...model based on the research variables and constructs identified using structural equation modeling and the fuzzy set qualitative comparative analysis (FsQCA) approach. Data were collected from 278 food firms. The findings indicate that the implementation of an AI marketing strategy affects performance. Additionally, this study shows that marketing capabilities, customer value co‐creation, and market orientation are positively related to performance. Finally, the results highlight that marketing capabilities, customer value co‐creation, and market orientation affect the development of AI marketing strategies. The research results of FsQCA find that causal conditions of marketing capabilities, customer value co‐creation, market orientation, and AI marketing strategy are necessary and sufficient recipes for higher firm performance.
This study examines the antecedents of destination loyalty and its relation to destination image, consumer travel experience, and destination satisfaction in the tourism context. This study raises ...important questions concerning how destination image, consumer travel experience, and destination satisfaction affect destination loyalty. This research attempts to identify three key antecedents of loyalty in the tourism context. The study empirically tests predicted relationships by using personal interview data from 475 foreign tourists. The conceptual model investigates the relevant relationships among the research constructs by using fuzzy-set Qualitative Comparative Analysis (fsQCA) and structural equation modeling (SEM) approach. Findings from the research sample support the argument that destination image, consumer travel experience, destination satisfaction are the key determinants of destination loyalty. Furthermore, destination image and consumer travel experience influence destination satisfaction. The study also discusses theoretical and managerial implications of research findings for marketing the tourism products globally.
Abstract
CO
2
hydrogenation has attracted great attention, yet the quest for highly-efficient catalysts is driven by the current disadvantages of poor activity, low selectivity, and ambiguous ...structure-performance relationship. We demonstrate here that C
3
N
4
-supported Cu single atom catalysts with tailored coordination structures, namely, Cu–N
4
and Cu–N
3
, can serve as highly selective and active catalysts for CO
2
hydrogenation at low temperature. The modulation of the coordination structure of Cu single atom is readily realized by simply altering the treatment parameters. Further investigations reveal that Cu–N
4
favors CO
2
hydrogenation to form CH
3
OH via the formate pathway, while Cu–N
3
tends to catalyze CO
2
hydrogenation to produce CO via the reverse water-gas-shift (RWGS) pathway. Significantly, the CH
3
OH productivity and selectivity reach 4.2 mmol g
–1
h
–1
and 95.5%, respectively, for Cu–N
4
single atom catalyst. We anticipate this work will promote the fundamental researches on the structure-performance relationship of catalysts.
As the population ages due to demographic trends and gains in life expectancy, the incidence and prevalence of dementia increases, and the need to understand the etiology and pathogenesis of dementia ...becomes ever more urgent. Alzheimer's disease (AD), the most common form of dementia, is a complex disease, the mechanisms of which are poorly understood. The more we learn about AD, the more questions are raised about our current conceptual models of disease. In the absence of a cure or the means by which to slow disease progress, it may be prudent to apply our current knowledge of the intersection between AD, cardiovascular disease, and cerebrovascular disease to foster efforts to delay or slow the onset of AD. This review discusses our current understanding of the epidemiology, genetics, and pathophysiology of AD, the intersection between AD and vascular causes of dementia, and proposes future directions for research and prevention.
Guidelines recommend exercise for cardiovascular health, although evidence from trials linking exercise to cardiovascular health through intermediate biomarkers remains inconsistent. We performed a ...meta-analysis of randomized controlled trials to quantify the impact of exercise on cardiorespiratory fitness and a variety of conventional and novel cardiometabolic biomarkers in adults without cardiovascular disease.
Two researchers selected 160 randomized controlled trials (7487 participants) based on literature searches of Medline, Embase, and Cochrane Central (January 1965 to March 2014). Data were extracted using a standardized protocol. A random-effects meta-analysis and systematic review was conducted to evaluate the effects of exercise interventions on cardiorespiratory fitness and circulating biomarkers. Exercise significantly raised absolute and relative cardiorespiratory fitness. Lipid profiles were improved in exercise groups, with lower levels of triglycerides and higher levels of high-density lipoprotein cholesterol and apolipoprotein A1. Lower levels of fasting insulin, homeostatic model assessment-insulin resistance, and glycosylated hemoglobin A1c were found in exercise groups. Compared with controls, exercise groups had higher levels of interleukin-18 and lower levels of leptin, fibrinogen, and angiotensin II. In addition, we found that the exercise effects were modified by age, sex, and health status such that people aged <50 years, men, and people with type 2 diabetes, hypertension, dyslipidemia, or metabolic syndrome appeared to benefit more.
This meta-analysis showed that exercise significantly improved cardiorespiratory fitness and some cardiometabolic biomarkers. The effects of exercise were modified by age, sex, and health status. Findings from this study have significant implications for future design of targeted lifestyle interventions.
This study examines the role of social media marketing strategy and its relation to organizational culture, strategic leadership, organizational learning, social network, innovation orientation, and ...performance in the chain store and franchise context. The study uses data from 327 active firms from a chain store and franchise system in Taiwan. The study tests the predictions of relationships using mail survey data from the sample, and employs structural equation modeling (SEM) and fuzzy set qualitative comparative analysis (fsQCA) to analyze the research questions. Results show that social media marketing strategy, organizational culture, strategic leadership, organizational learning, social network, and innovation orientation are key factors in reinforcing a firms' organizational performance within the chain store and franchise system. The study provides theoretical and managerial implications.
Poor housing conditions have been linked with worse health outcomes and infectious disease spread. Since the relationship of poor housing conditions with incidence and mortality of COVID-19 is ...unknown, we investigated the association between poor housing condition and COVID-19 incidence and mortality in US counties.
We conducted cross-sectional analysis of county-level data from the US Centers for Disease Control, US Census Bureau and John Hopkins Coronavirus Resource Center for 3135 US counties. The exposure of interest was percentage of households with poor housing conditions (one or greater of: overcrowding, high housing cost, incomplete kitchen facilities, or incomplete plumbing facilities). Outcomes were incidence rate ratios (IRR) and mortality rate ratios (MRR) of COVID-19 across US counties through 4/21/2020. Multilevel generalized linear modeling (with total population of each county as a denominator) was utilized to estimate relative risk of incidence and mortality related to poor housing conditions with adjustment for population density and county characteristics including demographics, income, education, prevalence of medical comorbidities, access to healthcare insurance and emergency rooms, and state-level COVID-19 test density. We report incidence rate ratios (IRRs) and mortality ratios (MRRs) for a 5% increase in prevalence in households with poor housing conditions.
Across 3135 US counties, the mean percentage of households with poor housing conditions was 14.2% (range 2.7% to 60.2%). On April 21st, the mean (SD) number of cases and deaths of COVID-19 were 255.68 (2877.03) cases and 13.90 (272.22) deaths per county, respectively. In the adjusted models standardized by county population, with each 5% increase in percent households with poor housing conditions, there was a 50% higher risk of COVID-19 incidence (IRR 1.50, 95% CI: 1.38-1.62) and a 42% higher risk of COVID-19 mortality (MRR 1.42, 95% CI: 1.25-1.61). Results remained similar using earlier timepoints (3/31/2020 and 4/10/2020).
Counties with a higher percentage of households with poor housing had higher incidence of, and mortality associated with, COVID-19. These findings suggest targeted health policies to support individuals living in poor housing conditions should be considered in further efforts to mitigate adverse outcomes associated with COVID-19.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Corner‐sharing oxides usually suffer from structural reconstruction during the bottleneck oxygen‐evolution reaction (OER) in water electrolysis. Therefore, introducing dynamically stable active sites ...in an alternative structure is urgent but challenging. Here, 1D 5H‐polytype Ba5Bi0.25Co3.75FeO14−δ oxide with face‐sharing motifs is identified as a highly active and stable candidate for alkaline OER. Benefiting from the stable face‐sharing motifs with three couples of combined bonds, Ba5Bi0.25Co3.75FeO14−δ can maintain its local structures even under high OER potentials as evidenced by fast operando spectroscopy, contributing to a negligible performance degradation over 110 h. Besides, the higher Co valence and smaller orbital bandgap in Ba5Bi0.25Co3.75FeO14−δ endow it with a much better electron transport ability than its corner‐sharing counterpart, leading to a distinctly reduced overpotential of 308 mV at 10 mA cm−2 in 0.1 m KOH. Further mechanism studies show that the short distance between lattice‐oxygen sites in face‐sharing Ba5Bi0.25Co3.75FeO14−δ can accelerate the deprotonation step (*OOH + OH− = *OO + H2O + e−) via a steric inductive effect to promote lattice‐oxygen participation. In this work, not only is a new 1D face‐sharing oxide with impressive OER performance discovered, but also a rational design of dynamic stable and active sites for sustainable energy systems is inaugurated.
The 1D 5H‐polytype Ba5Bi0.25Co3.75FeO14−δ oxide with high‐valence face‐sharing motifs is developed as a highly efficient and stable electrocatalyst for oxygen‐evolving reaction. This exceptional face‐sharing structure can be maintained even under high anodic potentials and accelerates the deprotonation step (*OOH + OH− = *OO + H2O + e−) via a steric inductive effect to promote lattice‐oxygen participation.
Background/aims
Direct‐acting antivirals (DAAs) are highly effective in treating chronic hepatitis C virus (HCV)‐infected patients. The real‐world treatment outcome in Taiwanese patients on a ...nationwide basis is elusive.
Methods
The Taiwan HCV Registry (TACR) programme is a nationwide registry platform including 48 study sites, which is organized and supervised by the Taiwan Association for the Study of the Liver. The primary endpoint was sustained virological response (SVR12, undetectable HCV RNA 12 weeks after end‐of‐treatment).
Results
A total of 13 951 registered patients with SVR12 data available were analysed (mean age, 63.0 years; female, 55.9%; HCV genotype‐1 GT1, 57.9%; cirrhosis, 38.4%; preexisting hepatocellular carcinoma HCC, 10.6%; and hepatitis B virus coinfection, 7.7%). The overall SVR12 rate was 98.3%, with 98.7%, 98.0%, 98.4% and 97.4% in treatment‐naïve noncirrhotic, treatment‐naïve cirrhotic, treatment‐experienced noncirrhotic and treatment‐experienced cirrhotic patients, respectively. The SVR12 rate was > 95% across all subgroups except treatment‐experienced cirrhotic patients who received sofosbuvir/ribavirin (88.7%), treatment‐naïve noncirrhotic patients (94.8%) and treatment‐experienced cirrhotic (94.8%) patients who received daclatasvir/asunaprevir. The most important factor associated with treatment failure was DAA adherence < 60% ( adjusted odds ratio aOR/95% confidence interval CI: 117.1/52.4‐261.3, P < .001), followed by GT3/GT2 (aOR/CI: 5.78/2.25‐14.9, P = .0003 and aOR/CI: 1.55/1.05‐2.29, P = .03, compared with GT1), active hepatocellular carcinoma (aOR/CI: 4.29/2.57‐7.16, P < .001), the use of sofosbuvir/ribavirin (aOR/CI: 2.51/1.67‐3.77, P < .001) and daclatasvir/asunaprevir (aOR/CI: 3.29/1.94‐5.58, P < .001), decompensated liver cirrhosis (aOR/CI: 2.50/1.20‐5.22, P = .02) and high HCV viral loads (aOR/CI: 2.16/1.57‐2.97, P < .001).
Conclusions
DAAs are highly effective in treating Taiwanese HCV patients in the real‐world setting. Maintaining DAA adherence and selecting highly efficacious regimens are keys to ensure treatment success.
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