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Solid oxide fuel cells that operate at intermediate temperatures require efficient catalysts to enhance the inherently poor electrochemical activity of the composite electrodes. Here, a simple and practical electrochemical deposition method is presented for fabricating a PrOx overlayer on lanthanum strontium manganite-yttria-stabilized zirconia (LSM-YSZ) composite electrodes. The method requires less than four minutes for completion and can be carried out under at ambient temperature and pressure. Crucially, the treatment significantly improves the electrode's performance without requiring heat treatment or other supplementary processes. The PrOx-coated LSM-YSZ electrode exhibits an 89% decrease in polarization resistance at 650 °C (compared to an untreated electrode), maintaining a tenfold reduction after ≈400 h. Transmission line model analysis using impedance spectra confirms how PrOx coating improved the oxygen reduction reaction activity. Further, tests with anode-supported single cells reveal an outstanding peak power density compared to those of other LSM-YSZ-based cathodes (e.g., 418 mW cm-2 at 650 °C). Furthermore, it is demonstrated that multicomponent coating, such as (Pr,Ce)Ox, can also be obtained with this method. Overall, the observations offer a promising route for the development of high-performance solid oxide fuel cells.
RESUMO
BACKGROUND: There is growing evidence that abnormal liver function tests (LFTs) are common in patients with coronavirus disease 2019 (COVID-19). However, it is not known whether viral involvement in the liver differs according to the strain. We investigated the impact on liver injury in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta (B.1.617.2) variants. MATERIALS AND METHODS: We conducted a single-center, retrospective cohort study, including 372 patients admitted during the pre-Delta period (PDP: between February 1 and November 30, 2020) and 137 patients admitted during the Delta period (DP: between August 1 and August 31, 2021). Initial liver injury was defined as alanine aminotransferase (ALT) or aspartate aminotransferase (AST) levels ≥3 × the upper limit of normal (ULN) or alkaline phosphatase (ALP) or total bilirubin ≥2 × the ULN within 3 days from admission. RESULTS: Of 509 patients with COVID-19 included in our study, 38 (7.5%) patients had initial liver injury. The DP group had a significantly higher rate of initial liver injury than the PDP group (PDP: 5.9% vs. DP: 11.7%, P = 0.028). The DP group (adjusted odds ratio [aOR]: 2.737, 95% confidence interval [CI]: 1.322 - 5.666) was independently associated with initial liver injury. During hospitalization, 160 (31.4%) patients had severe COVID-19. The DP group and initial liver injury had higher odds of progressing to severe COVID-19 (aOR: 2.664, 95% CI: 1.526 - 4.648, and aOR: 4.409, 95% CI: 1.816 - 10.707, respectively). The mediation analysis suggested that initial liver injury mediates the relationship between SARS-CoV-2 Delta variant infection and severe COVID-19 (unstandardized beta coefficient = 0.980, Standard error = 0.284, P = 0.001). CONCLUSION: Initial liver injury is more common in COVID-19 patients with Delta variants. Also, Delta variants and initial liver injury are associated with poor clinical outcomes.
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BACKGROUND: Because of the very low incidence of human immunodeficiency virus (HIV) coinfection in Korea, data on hepatitis C virus (HCV)/HIV coinfection are limited. This study aimed to investigate the clinical characteristics and treatment outcomes of patients with HCV/HIV coinfection in Korea. METHODS: We performed a retrospective cohort study of all HCV-monoinfected and HCV/HIV-coinfected patients treated with antivirals at National Medical Center in Seoul, Korea, between January 2009 and March 2020. RESULTS: We enrolled 220 HCV-monoinfected and 23 HCV/HIV-coinfected patients treated with antivirals. The HCV/HIV-coinfected patients were younger (HCV vs. HCV/HIV: 57.3 ± 11.3 vs. 40.7 ± 10.1 years, P < 0.001) and had a higher proportion of men (HCV vs. HCV/HIV: 54.5% [n = 120] vs. 91.3% [n = 21], P < 0.001) than the HCV-monoinfected patients. Genotype 1b and 2 were most common in both HCV monoinfection and HCV/HIV coinfection groups. HCV-monoinfected patients had a higher incidence of genotype 1b and 2 than HCV/HIV-coinfected patients (HCV vs. HCV/HIV: 95.4% [n = 210] vs. 73.9% [n = 17], P < 0.001), while the HCV/HIV-coinfected patients had genotype 1a (HCV vs. HCV/HIV: 1.8% [n = 4] vs. 21.7% [n = 5], P < 0.001). The fibrosis-4 index was significantly lower in the HCV/HIV-coinfected patients than in the HCV-monoinfected patients (HCV vs. HCV/HIV: 3.81 ± 3.38 vs. 1.66 ± 1.10, P < 0.001). Among the direct-acting antivirals (DAA)-treated patients, the sustained viral response (SVR) rate did not differ significantly between both groups (HCV vs. HCV/HIV: 94.9% [93/99] vs. 90.9% [10/11], P = 0.480). CONCLUSION: In Korea, the HCV/HIV-coinfected patients who received antiviral treatment were younger, had higher proportion of men and incidence of genotype 1a, and had less advanced fibrosis than the HCV-monoinfected patients. In actual clinical settings, HCV/HIV-coinfected patients show excellent SVR to DAA treatment, similar to HCV-monoinfected patients.
