Summary
High‐temperature solid oxide fuel cells (HT‐SOFCs) generally operate at 800°C to 1000°C and intermediate temperature SOFCs (IT‐SOFCs) at 600°C to 800°C. Reducing the SOFCs operational from ...high to ITs results in many issues mainly at the cathode site. One of the shortcomings that have been addressed is high polarization losses associated with oxygen reduction reaction (ORR) and degradation of La1−xSrxCo1−yFeyO3−δ (LSCF) cathode materials. Strontium (Sr) has been discovered to segregate and inhibit the surface‐active site for the ORR under specified conditions (temperature, relative humidity, and suppressing activity). It enriched the surface, formed Sr‐rich secondary phases, and eventually changes the composition and the structure of the perovskite surfaces. Therefore, this review aims to summarize the occurrences of Sr segregation at the LSCF cathode surfaces as a function of operating conditions and their effects on the material performance. In addition, the characterization techniques utilized to investigate the Sr segregation, and strategies for Sr segregation mitigation are also discussed.
Factors Influence Strontium Segregation on LSCF Perovskite Oxide.
This study numerically investigates methanol steam reformer design using the COMSOL software. The reformer is heated with internal heating tubes (HTs). The effects of the reformer shape, the heating ...tube arrangement and heating rate are studied. Results show that a divergent reformer shape has the highest methanol conversion (68%) due to slower average flow rate of the reactants, longer residence time, and more heat absorption. For fixed heating rate, increasing the number of HTs increases the methanol conversion rate by up to 14.8% due to better heat transfer. Furthermore, methanol conversion can also be enhanced with increasing heating rate and placing HTs towards reactor center. The optimal design of a divergent tube with a divergent angle of 5° and 8 HTs has a maximum conversion rate of 94.5%. The results of this study are helpful for engineers working on designing an MSR with high-methanol conversion rate.
•Straight, divergent, and convergent tubes of MSR are analyzed.•The divergent tube has the highest methanol conversion of 67.9%.•Increasing number of heating tubes can enhance methanol conversion by up to 14.8%.•The maximum methanol conversion rate of 94.5% is achieved in this study.
To enhance Li storage properties, nitrogenation methods are developed for Si anodes. First, melamine, urea, and nitric oxide (NO) precursors are used to nitrogenize carbon‐coated Si particles. The ...properties of the obtained particles are compared. It is found that the NO process can maximize the graphitic nitrogen (N) content and electronic conductivity of a sample. In addition, optimized N functional groups and O─C species on the electrode surface increase electrolyte wettability. However, with a carbon barrier layer, NO hardly nitrogenizes the Si cores. Therefore, bare Si particles are reacted with NO. Core‐shell Si@amorphous SiNx particles are produced using a facile and scalable NO treatment route. The effects of the NO reaction time on the physicochemical properties and charge–discharge performance of the obtained materials are systematically examined. Finally, the Si@SiNx particles are coated with N‐doped carbon. Superior capacities of 2435 and 1280 mAh g−1 are achieved at 0.2 and 5 A g−1, respectively. After 300 cycles, 90% of the initial capacity is retained. In addition, differential scanning calorimetry data indicate that the multiple nitrogenation layers formed by NO significantly suppress electrode exothermic reactions during thermal runaway.
A unique double nitrogenation layer on Si cores is developed. An electrode with this double nitrogenation layer shows significantly suppressed exothermic reactions during thermal runaway. A Si/NO/C‐N||LiNi0.8Co0.1Mn0.1O2 full cell exhibits a high energy density of 585 Wh kg−1 and retains >90% of its initial capacity after 300 cycles. The proposed double nitrogenation method is facile, cost‐effective, and scalable for practical applications.
Variants of transcription factor binding sites (TFBSs) constitute an important part of the human genome. Current evidence demonstrates close links between nucleotides within TFBSs and gene ...expression. There are multiple pathways through which genomic sequences located in TFBSs regulate gene expression, and recent genome-wide association studies have shown the biological significance of TFBS variation in human phenotypes. However, numerous challenges remain in the study of TFBS polymorphisms. This article aims to cover the current state of understanding as regards the genomic features of TFBSs and TFBS variants; the mechanisms through which TFBS variants regulate gene expression; the approaches to studying the effects of nucleotide changes that create or disrupt TFBSs; the challenges faced in studies of TFBS sequence variations; the effects of natural selection on collections of TFBSs; in addition to the insights gained from the study of TFBS alleles related to gout, its associated comorbidities (increased body mass index, chronic kidney disease, diabetes, dyslipidemia, coronary artery disease, ischemic heart disease, hypertension, hyperuricemia, osteoporosis, and prostate cancer), and the treatment responses of patients.
Although many genome-wide association studies (GWASs) of hyperuricemia or gout have been reported, the related genetic factors and the mechanisms from hyperuricemia to gouty attack remain unclear. ...This study aimed to identify genetic factors and pathogenesis of gout from hyperuricemia by genome-wide association study (GWAS). 747 gout patients, 747 hyperuricemia and 2071 age-matched controls were recruited and analyzed with Affymetrix 650 K chip to find the related genetic variants. The functions of the related genes were investigated in an endothelial cell (EC) with urate crystal stimulation. The GWAS results showed 36 SNPs to be strongly associated with gout compared to controls (all p-values < 10
). Whereas the rs2231142 in ABCG2 gene had significant associations between gout and controls, between gout and hyperuricemia, and between hyperuricemia and controls (all p-values < 10
), and the ORs were 4.34, 3.37 and 2.15 (all p-values < 0.001) after adjustment of potential confounders, respectively. The cell model showed significantly higher IL-8 release from EC combined with ABCG2 knockdown. We concluded that ABCG2 gene contributed to hyperuricemia but also gout, and that it was involved in the inflammation dysregulation via augmented IL-8 release in EC.
The performance of a methanol-fed protonic ceramic fuel cell (PCFC)/gas turbine (GT) hybrid system is investigated in this work. To build the system, Thermolib software is employed with input ...parameters obtained from references. Effects of air stoichiometry on system performance are analyzed. Results show that, as air stoichiometry is increased, the reformer temperature and CO concentration decrease, while H2 concentration increases. High air stoichiometry decreases PCFC temperature and performance. GT output power increases with increasing air flow. But, the power consumption by compressor also increases. Overall, to achieve higher system efficiency for this hybrid system, the optimum values of air stoichiometry are from 2.7 to 2.9. An additional heat recovery steam generator can also improve the overall system efficiency from 66.5% to 71.7%. This work helps in understanding the modeling and optimum functioning parameters of high power generation systems.
•A PCFC/GT hybrid system fed by methanol is proposed.•A parametric study of air stoichiometry is investigated to obtain optimal values.•Maximum hybrid system efficiency of 71.7% can be obtained.•Higher amount of air increases gas turbine power output.•The optimal air stoichiometry is 2.7–2.9.
The development of high performance, stable catalyst with non-precious metals for electrochemical hydrogen evolution reaction for alkaline electrolysis is in demand. Here-in, we report the synthesis ...of CuFe layered double hydroxide (LDH) electrocatalyst on nickel foam via facile hydrothermal method. In alkaline electrolysis with 1 M NaOH electrolyte, CuFe LDH as cathode requires an overpotential of 159 mV to generate current density of 10 mA cm−2. Which is ca. 51 mV and 7 mV lower than NiFe LDH and NiRu LDH. CuFe LDH exhibits significant electrocatalytic activity for HER. The higher catalytic activity of CuFe LDH compared to NiFe LDH may be achieved with higher proton adsorption by Cu compared to Ni. Also, the efficient charge transfer with interconnected LDH layers, favourable three dimensional structure facilitating easy electrolyte transfer to the active sites and hydrogen gas diffusion. This work may help in developing low cost and efficient hydroxide catalyst.
•CuFe layered double hydroxide is prepared by hydrothermal process.•Synthesis of low cost and non-precious metal electrocatalyst for electrolysis.•CuFe LDH/Ni electrocatalyst requires only 159 mV at 10 mA cm−2 in HER.•Stable after 5 h chronopotentiometry test.
Current knowledge of gout centers on hyperuricemia. Relatively little is known regarding the pathogenesis of gouty inflammation. To investigate the epigenetic background of gouty inflammation ...independent of hyperuricemia and its relationship to genetics, 69 gout patients and 1455 non-gout controls were included. Promoter-wide methylation was profiled with EPIC array. Whole-genome sequencing data were included for genetic and methylation quantitative trait loci (meQTL) analyses and causal inference tests. Identified loci were subjected to co-methylation analysis and functional localization with DNase hypersensitivity and histone marks analysis. An expression database was queried to clarify biologic functions of identified loci. A transcription factor dataset was integrated to identify transcription factors coordinating respective expression. In total, seven CpG loci involved in interleukin-1β production survived genetic/meQTL analyses, or causal inference tests. None had a significant relationship with various metabolic traits. Additional analysis suggested gouty inflammation, instead of hyperuricemia, provides the link between these CpG sites and gout. Six (
,
,
,
,
, and
) were novel genes in the field of gout. One (
) was previously associated with gouty inflammation. Transcription factor mapping identified several potential transcription factors implicated in the link between differential methylation, interleukin-1β production, and gouty inflammation. In conclusion, this study revealed several novel genes specific to gouty inflammation and provided enhanced insight into the biological basis of gouty inflammation.
Connective tissue disease-associated interstitial lung disease (CTD-ILD) is a severe manifestation of CTD that leads to significant morbidity and mortality. Clinically, ILD can occur in diverse CTDs. ...Pathologically, CTD-ILD is characterized by various histologic patterns, such as nonspecific interstitial pneumonia, organizing pneumonia, and usual interstitial pneumonia. Abnormal immune system responses have traditionally been instrumental in its pathophysiology, and various changes in immune cells have been described, especially in macrophages. This article first briefly overviews the epidemiology, clinical characteristics, impacts, and histopathologic changes associated with CTD-ILD. Next, it summarizes the roles of various signaling pathways in macrophages or products of macrophages in ILD, helped by insights gained from animal models. In the following sections, this review returns to studies of macrophages in CTD-ILD in humans for an overall picture of the current understanding. Finally, we direct attention to potential therapies targeting macrophages in CTD-ILD in investigation or in clinical trials, as well as the future directions regarding macrophages in the context of CTD-ILD. Although the field of macrophages in CTD-ILD is still in its infancy, several lines of evidence suggest the potential of this area.
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