RESUMO
Proton exchange membrane water electrolysers promise to usher in a new era of clean energy, but they remain a formidable obstacle in designing active and durable electrocatalysts for the acidic oxygen evolution reaction (OER). In this study, a protonated iridium oxide embedded with single-atom dispersed ruthenium atoms (H3.8Ir1- xRuxO4) that demonstrates exceptional activity and stability in acidic water oxidation is introduced. The single Ru dopants favorably induce localized oxygen vacancies in the IrâO lattice, synergistically strengthening the adsorption of OOH* intermediates and enhancing the intrinsic OER activity. In addition, the preferential oxidation of Ru and the electronegativity of the oxygen vacancies significantly stabilize the IrâO active sites, improving the OER stability. Consequently, the H3.8Ir1â xRuxO4 catalyst shows an overpotential of 255 mV at 10 mA cm-2 and displays exceptional catalytic endurance in acidic electrolytes, surpassing 1100 h, representing a remarkable one-order-of-magnitude increase in stability compared to that of pristine H3.8IrO4. A proton exchange membrane electrolyser utilizing the H3.8Ir1- xRuxO4 catalyst as an anode exhibits stable performance for more than 1280 h under a high current density of 2 A cm-2.
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The basic mechanism of heterosis has not been systematically and completely characterized. In previous studies, we obtained three economically important fishes that exhibit rapid growth, WR (WCC â × RCC â), WR-II (WR â × WCC â), and WR-III (WR-II â × 4nAU â), through distant hybridization. However, the mechanism underlying this rapid growth remains unclear. In this study, we found that WR, WR-II, and WR-III showed muscle hypertrophy and higher muscle protein and fat contents compared with their parent species (RCC and WCC). Candidate genes responsible for this rapid growth were then obtained through an analysis of 12 muscle transcriptomes. Notably, the mRNA level of mstnb (myostatin b), which is a negative regulator of myogenesis, was significantly reduced in WR, WR-II, and WR-III compared with the parent species. To verify the function of mstnb, a mstnb-deficient mutant RCC line was generated using the CRISPR-Cas9 technique. The average body weight of mstnb-deficient RCC at 12 months of age was significantly increased by 29.57% compared with that in wild-type siblings. Moreover, the area and number of muscle fibers were significantly increased in mstnb-deficient RCC, indicating hypertrophy and hyperplasia. Furthermore, the muscle protein and fat contents were significantly increased in mstnb-deficient RCC. The molecular regulatory mechanism of mstnb was then revealed by transcription profiling, which showed that genes related to myogenesis (myod, myog, and myf5), protein synthesis (PI3K-AKT-mTOR), and lipogenesis (pparγ and fabp3) were highly activated in hybrid fishes and mstnb-deficient RCC. This study revealed that low expression or deficiency of mstnb regulates somatic growth by promoting myogenesis, protein synthesis, and lipogenesis in hybrid fishes and mstnb-deficient RCC, which provides evidence for the molecular mechanism of heterosis via distant hybridization.
Assuntos
Hibridização Genética , Desenvolvimento Muscular , Miostatina , Animais , Miostatina/genética , Miostatina/metabolismo , Desenvolvimento Muscular/genética , Vigor Híbrido/genética , Masculino , Peixes/genética , Peixes/crescimento & desenvolvimento , Peixes/metabolismo , Feminino , Transcriptoma , Proteínas Musculares/genética , Proteínas Musculares/metabolismo , Músculo Esquelético/metabolismo , Músculo Esquelético/crescimento & desenvolvimento , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismoRESUMO
BACKGROUND: Nasopharyngeal carcinoma (NPC) is a malignant tumor with high incidence. Notoginsenoside R1 (NGR1) is the main active compound of total Panax notoginseng saponin, and has multiple anti-tumor effects. This study aimed to investigate the effect and mechanism of NGR1 in NPC. MATERIALS: NPC cells were treated with different doses of NGR1. The NGR1 function in NPC was evaluated using Cell Counting Kit-8, Transwell, Western blot, flow cytometry, immunofluorescence assay, and quantitative real-time PCR. Meanwhile, the NGR1 mechanism in NPC was assessed by rescue experiments. Furthermore, the NGR1 function in vivo was determined by constructing an NPC xenotransplantation model, TUNEL, and immunohistochemistry assays. RESULTS: NGR1 repressed NPC cell growth and invasion but facilitated NPC cell apoptosis and oxidative stress. Also, NGR1 alleviated inflammation in NPC cells. Mechanistically, NGR1 restrained NPC cell growth and induced oxidative stress in NPC cells, while these effects were abolished after lipopolysaccharide (an activator of the TRAF6/NF-κB pathway) treatment, implying that NGR1 reduced NPC cell growth and induced oxidative stress in NPC cells by the inactivation of TRAF6/NF-κB axis. Moreover, in vivo studies further proved the palliative effect of NGR1 on NPC. CONCLUSION: NGR1 inhibited NPC cell growth and induced oxidative stress in NPC cells by inactivating TRAF6/NF-κB axis.
Assuntos
Ginsenosídeos , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas , Humanos , Ginsenosídeos/farmacologia , Ginsenosídeos/uso terapêutico , Lipopolissacarídeos , Carcinoma Nasofaríngeo/tratamento farmacológico , Neoplasias Nasofaríngeas/tratamento farmacológico , NF-kappa B/metabolismo , Estresse Oxidativo , Fator 6 Associado a Receptor de TNF/metabolismo , Microambiente Tumoral , AnimaisRESUMO
Measuring risk is critical for collision avoidance. The paper aims to develop an online risk level classification algorithm for forward collision avoidance systems. Assuming risk levels are reflected by braking profiles, deceleration curves from critical evasive braking events from the Virginia "100-car" database were first extracted. The curves are then clustered into different risk levels based on spectrum clustering, using curve distance and curve changing rate as dissimilarity metrics among deceleration curves. Fuzzy logic rules of safety indicators at critical braking onset for risk classification were then extracted according to the clustered risk levels. The safety indicators include time to collision, time headway, and final relative distance under emergency braking, which characterizes three kinds of uncertain critical conditions respectively. Finally, the obtained fuzzy risk level classification algorithm was tested and compared with other Automatic Emergency Braking (AEB) algorithms under Euro-NCAP testing scenarios in simulation. Results show the proposed algorithm is promising in balancing the objectives of avoiding collision and reducing interference with driver's normal driving compared with other algorithms.
Assuntos
Acidentes de Trânsito/prevenção & controle , Condução de Veículo/psicologia , Automóveis , Equipamentos de Proteção , Algoritmos , Desaceleração , Lógica Fuzzy , Humanos , Medição de Risco , VirginiaRESUMO
Long non-coding RNAs (lncRNAs) have gained widespread attention in recent years as a key regulator of diverse biological processes, but the knowledge of the mechanisms by which they act is still very limited. Differentially expressed lncRNA SMAD5 antisense RNA 1 (SMAD5-AS1) in nasopharyngeal carcinoma (NPC) and normal samples shown by in silico analyses were selected as the main subject, and then microRNA-195 (miR-195) was suggested to bind to SMAD5-AS1 and SMAD5. Therefore, the purpose of the present study was to investigate the effects of SMAD5-AS1/miR-195/SMAD5 on epithelial-mesenchymal transition (EMT) in NPC cells. High expression of SMAD5-AS1 and SMAD5 but low miR-195 expression was determined in NPC tissues and NPC cell lines by RT-qPCR and western blot analysis. SMAD5-AS1 could upregulate SMAD5 expression by competitively binding to miR-195 in NPC cells. Loss- and gain-of-function investigations were subsequently conducted in NPC cells (CNE-2 and CNE-1) to explore the role of SMAD5-AS, miR-195 and SMAD5 in NPC progression by assessing cellular biological functions and tumorigenic ability in vivo as well as determining the expression of EMT markers. Downregulation of SMAD5-AS1 or SMAD5 or overexpression of miR-195 led to inhibited NPC cell proliferation, invasion and migration and reversed EMT, enhanced apoptosis in vitro as well as restrained tumor growth in vivo. In conclusion, our findings indicate that silencing of lncRNA SMAD5-AS1 induces the downregulation of SMAD5 by miR-195, eventually repressing EMT in NPC. Hence, SMAD5-AS1 may represent a potential therapeutic target for NPC intervention.