RESUMEN
The electrocatalytic conversion of formate in alkaline solutions is of paramount significance in the realm of fuel cell applications. Nonetheless, the adsorptive affinity of adsorbed hydrogen (Had) on the catalyst surface has traditionally impeded the catalytic efficiency of formate in such alkaline environments. To circumvent this challenge, our approach introduces an interfacial push-pull effect on the catalyst surface. This mechanism involves two primary actions: First, the anchoring of palladium (Pd) nanoparticles on a phosphorus-doped TiO2 substrate (Pd/TiO2-P) promotes the formation of electron-rich Pd with a downshifted d band center, thereby "pushing" the desorption of Had from the Pd active sites. Second, the TiO2-P support diminishes the energy barrier for Had transfer from the Pd sites to the support itself, "pulling" Had to effectively relocate from the Pd active sites to the support. The resultant Pd/TiO2-P catalyst showcases a remarkable mass activity of 4.38 A mgPd-1 and outperforms the Pd/TiO2 catalyst (2.39 A mgPd-1) by a factor of 1.83. This advancement not only surmounts a critical barrier in catalysis but also delineates a scalable pathway to bolster the efficacy of Pd-based catalysts in alkaline media.
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This study addresses the critical challenge in alkaline direct formate fuel cells (DFFCs) of slow formate oxidation reaction (FOR) kinetics as a result of strong hydrogen intermediate (Had) adsorption on Pd catalysts. We developed WO3-supported Pd nanoparticles (EG-Pd/WO3) via an organic reduction method using ethylene glycol (EG), aiming to modulate the d-band center of Pd and alter Had adsorption dynamics. Cyclic voltammetry demonstrated significantly improved Had desorption kinetics in EG-Pd/WO3 catalysts. Density functional theory (DFT) calculations revealed that the presence of EG reduces the d-band center of Pd, leading to weaker Pd-H bonds and enhanced Had desorption during the FOR. This research provides a new approach to optimize catalyst efficiency in DFFCs, highlighting the potential for more effective and sustainable energy solutions through advanced material engineering.
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This study aimed to investigate the effect of dietary tetramethylpyrazine (TMP) on the growth performance, nutrient digestion, blood parameters and immunity of broilers under oxidative stress. Five treatments included negative control, positive control with lipopolysaccharide induction and TMP addition at 50, 100 and 150 mg/kg of diet using 600 male Arbor Acres broiler chicks. Results showed that during 1-14 days of age, body weight gain and feed efficiency in the positive control were worsened (p < .05) compared with the negative control, while with incremental TMP doses from 0 to 150 mg/kg there were linear and quadratic increases (p < .001) in body weight gain and a linear decrease in feed/gain (p = .001). During 12-14 days of age, with incremental TMP doses, crude protein digestibility was linearly increased (p = .001), and gross energy utilization was linearly and quadratically changed (p < .001). At 14 days of age, the TMP beneficially regulated digestive enzymes, blood parameters and immunoglobulins, showing linear and quadratic responses (p ≤ .008) on trypsin, lipase, glutamic pyruvic transaminase, glucose, lipoproteins, albumin, immunoglobulins (M, Y), interleukin 6 and interferon α, and only linear changes (p ≤ .030) on amylase, glutamic oxaloacetic transaminase, immunoglobulin A and interleukin 2. Most parameters in TMP groups reached to the levels of negative control and the effects of TMP at 100 or 150 mg/kg were more pronounced on body weight gain, crude protein digestibility, trypsin and glutamic pyruvic transaminase. It is concluded that TMP can be used as a feed additive capable of improving growth, blood parameter and immunity of broiler chicks under oxidative stress.
Asunto(s)
Alimentación Animal , Pollos , Alimentación Animal/análisis , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Dieta/veterinaria , Suplementos Dietéticos , Digestión , Masculino , Estrés Oxidativo , PirazinasRESUMEN
This study aimed to investigate the effect of a Lactobacillus plantarum DPP8 supplementation on the growth performance, pathogenic invasion, inflammation and pathogen resistance signal pathway in rabbits infected with Salmonella Typhimurium (S. Typhimurium). The treatments included a negative control, a positive control with an S. Typhimurium infection and a positive control plus DPP8 at 106, 108 or 1010 cfu/kg of diet using 300 weaned rabbits. The results showed that supplementing with DPP8 improved (P < 0.05) the feed intake, body weight gain and feed efficiency compared to the positive control. Also, DPP8 decreased (P < 0.05) the S. Typhimurium colonisation and translocation, serum IL-1ß, IL-6 and TNF-α, and intestinal mucosa mRNA expressions of the inflammatory mediators Janus kinase (Jak) 2, the signal transducer and activator of transcription (Stat) 1 and 3 at 7 and 14 d post administration. The dose analysis of DPP8 showed linear increases (P ≤ 0.007) in the feed intake and body weight gain, but linear decreases (P ≤ 0.022) in the S. Typhimurium loads, IL-1ß, IL-6 and Jak2. It is concluded that Lactobacillus plantarum DPP8 can be used as a supportive probiotic against an S. Typhimurium infection and it possibly plays a direct or indirect role in the downregulation of the Jak/Stat pathway in rabbits.
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OBJECTIVE: This study aimed to investigate the effect of Salvia miltiorrhiza (S.m.) aerial parts as an alternative ingredient on growth performance, nutrient digestibility, and digestive enzymes in growing rabbits. METHODS: Treatments included five tested diets: a control (basal diet), antibiotic (basal diet +enramycin at 5 mg/kg), and S.m. aerial parts powder added at 3.0%, 6.0%, and 9.0% of feed using 300 growing rabbits. RESULTS: The diets with S.m. aerial parts addition at 9.0% decreased (p<0.05) feed/gain compared to the control, but there were no differences in feed intake and body weight gain. In contrast with the control, the addition of antibiotic increased (p<0.05) digestibility of dry matter, crude protein, energy, fiber, and ash. The herb addition did not cause differences in the digestibility of most nutrients compared to the antibiotic, but fiber digestibility of the herb at 6.0% and 9.0% was lower (p<0.05) than that of the antibiotic. Moreover, the antibiotic and the herb also similarly increased (p<0.05) the activities of duodenal α-amylase, maltase, lipase, and trypsin, compared to the control, and the herb at 6.0% and 9.0% showed a greater (p<0.05) activity of elastase than the dose 3.0%. CONCLUSION: The obtained data indicate that S.m. aerial parts can be a potential forage in rabbit's diet at 9.0% with a beneficial regulation on nutrition and digestion.
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Tetramethylpyrazine (TMP), an alkaloid rich in Ligusticum wallichii and fermented products, possesses multiple pharmacological activities in antioxidant, anti-inflammatory, and antibacterial. This study aimed to investigate the effect of TMP (15 mg/L) on the physicochemical and gelation properties of rabbit myofibrillar proteins (MPs) with/without oxidative stress. Results showed that compared to the control, oxidative stress to MPs decreased free thiol content, gel yield, whiteness, water-holding capacity, bounder water, immobilized water, and endogenous tryptophan fluorescence intensity, but increased surface hydrophobicity, dityrosine content, and free water content (p<0.01). Without oxidative stress, MPs treated with TMP increased free thiol content, whiteness, and bound water, but decreased dityrosine content and free water (p<0.05). Under oxidative conditions, all parameters were conversely affected by TMP (p<0.01). The results suggest that TMP can be an antioxidant to decrease the concern on oxidative deterioration during meat processing and storage by improving the oxidative stability, water retention, and gel forming property of rabbit MPs.
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This study aimed to investigate the effect of dietary cysteamine hydrochloride (CSH) on the growth performance, oxidation, inflammation, and gene expression of cytoskeleton and tight junction in the intestinal mucosa of broiler chickens challenged with Clostridium perfringens (C. perfringens). A total of 360 one-day-old broiler chicks were randomly distributed into 5 groups for a negative control (NC, without C. perfringens challenge), a positive control (PC, with C. perfringens challenge), and PC plus CSH at 100, 150, or 200 mg/kg of diet. The results showed that average daily gain, gain:feed, cecal population and enterotoxin of C. perfringens were negatively affected (P < 0.05) by the C. perfringens challenge, but were conversely affected (P < 0.05) by the CSH supplementation, and G:F reached to the level of NC group. The PC group increased (P < 0.05) serum diamine oxidase, malondialdehyde, protein carbonyl, interleukin-6, interleukin-1ß, and tumor necrosis factor-α, whereas the supplementation of CSH decreased (P < 0.05) these parameters. Moreover, the C. perfringens challenge worsened the disruption of intestinal mucosal cytoskeleton and tight junction by downregulating (P < 0.05) the mRNA levels of actin protein of muscle Z-line alpha, syncoilin, synemin, tubulin, claudin-1, and zona occludens protein-2, while these parameters were partially compensated (P < 0.05) by CSH supplementation. For the dose trends of CSH, there were linear and quadratic (P < 0.05) effects on gain:feed, enterotoxins, tumor necrosis factor-α, tubulin alpha 1c, syncoilin, and synemin. In conclusion, the CSH can be an alternative against C. perfringens infection by beneficially regulating gut pathogenic bacteria and enterotoxins, oxidation, inflammation, cytoskeleton, and tight junction in broiler chickens.