RESUMO
Zn-ion hybrid supercapacitors (ZHCs) combining merits of battery-type and capacitive electrodes are considered to be a prospective candidate in energy storage systems. Tailor-made carbon cathodes with high zincophilicity and abundant physi/chemisorption sites are critical but it remains a great challenge to achieve both features by a sustainable means. Herein, a hydrogen-bonding interaction-guided self-assembly strategy is presented to prepare iodine-doped carbon nanocages without templates for boosting zinc-ion storage by nucleophilicity. The biomass ellagic acid contains extensional hydroxy and acyloxy groups with electron-donating ability, which interact with melamine and ammonium iodide to form organic supermolecules. The organic supermolecules further self-assemble into a nanocage-like structure with cavities under hydrothermal processes via hydrogen-bonding and π-π stacking. The carbon nanocages as ZHCs cathodes enable the high approachability of zincophilic sites and low ion migration resistance resulting from the interconnected conductive network and nanoscale architecture. The experimental analyses and theoretical simulations reveal the pivotal role of iodine dopants. The I5-/I3- doping anions in carbon cathodes have a nucleophilicity to preferentially adsorb the Zn2+ cation by the formation of C+-I5--Zn2+ and C+-I3--Zn2+. Of these, the C+-I3- shows stronger bonding with Zn2+ than C+-I5-. As a result, the iodine-doped carbon nanocages produced via this template-free strategy deliver a high capacity of 134.2 mAh/g at 1 A/g and a maximum energy and power density of 114.1 Wh/kg and 42.5 kW/kg.
RESUMO
OBJECTIVE: To investigate the protective effect and mechanism of low dose glucocorticoid(GC) on sepsis induced acute kidney injury(AKI) in rat. METHODS: Eighty healthy Wistar male rats were randomly divided into sham group (n=10), AKI model group (AKI group, n=35)and hydrocortisone treatment group(HC group, n=35),according to random digital table. Septic AKI model was reproduced using cecal ligation and puncture (CLP). After the procedure hydrocortisone 6 mg/kg was injected via sublingual vein in HC group. At 24 hours after the procedure, blood was obtained and the animals were sacrificed in all groups. Pathological changes in the kidney were observed with hematoxylin eosin (HE) staining. The expressions of glucocorticoid receptor alpha (GR-α) and nuclear transcription factor-ΚB (NF-ΚB) in the kidney were assessed by immunohistochemistry. The levels of tumor necrosis factor alpha (TNF-α) and interleukins (IL-1ß, IL-6,IL-10) in the plasma were determined by enzyme-linked immunosorbent assay(ELISA). RESULTS: ¹ The difference in survival rates in AKI group and HC group showed no statistical significance (42.8% vs. 48.6%,P>0.05). ² Renal tubular epithelial cells were swollen and exfoliated, with loss and vacuolation of tubular brush border under light microscope in AKI group. Pathological changes in renal tubules in HC group were alleviated. ³ Compared with AKI group, the expression of GR-α was increased [absorbance (A) value: 0.35 ± 0.05 vs. 0.25 ± 0.05,P<0.01] and the expression of NF-ΚB was decreased in HC group (A value: 0.23 ± 0.04 vs.0.34 ± 0.04,P<0.01). Compared with AKI group, the levels of TNF-α, IL-1ß, IL-6 were lowered [TNF-α (ng/L): 94.25 ± 7.96 vs. 118.24 ± 6.63; IL-1ß (ng/L): 19.14 ± 1.99 vs. 28.91 ± 6.81; IL-6 (ng/L): 66.32 ± 1.99 vs. 85.70 ± 11.54; all P <0.01] and the level of IL-10 (ng/L) was elevated (98.33 ± 6.68 vs. 88.59 ± 7.34,P<0.01) in HC group. CONCLUSION: A low dose of hydrocortisone can inhibit the activity of NF-ΚB, possibly by means of increasing the expression of renal GR-α in septic rats. Accordingly it reduces the production of pro-inflammatory factors which participate in sepsis. So it effectively inhibits inflammation in sepsis and protects the kidney in septic rats.
