AIM: To investigate the effect and mechanism of stimulation of the hypothalamic paraventricular nucleus with glutamate acid in rats with ulcerative colitis(UC).METHODS: The rats were anesthetized with 10% chloral hydr...AIM: To investigate the effect and mechanism of stimulation of the hypothalamic paraventricular nucleus with glutamate acid in rats with ulcerative colitis(UC).METHODS: The rats were anesthetized with 10% chloral hydrate via abdominal injection and treated with an equal volume of TNBS + 50% ethanol enema, injected into the upper section of the anus with the tail facing up. Colonic damage scores were calculated after injecting a certain dose of glutamic acid into the paraventricular nucleus(p VN), and the effect of the nucleus tractus solitarius(NTS) and vagus nerve in alleviating UC injury through chemical stimulation of the p VN was observed in rats. Expression changes of C-myc, Apaf-1, caspase-3, interleukin(IL)-6, and IL-17 during the protection against UC injury through chemical stimulation of the p VN in rats were detected by Western blot. Malondialdehyde(MDA) content and superoxide dismutase(SOD) activity in colon tissues of rats were measured by colorimetric methods. RESULTS: Chemical stimulation of the PVN significantly reduced UC in rats in a dose-dependent manner. The protective effects of the chemical stimulationof the p VN on rats with UC were eliminated after chemical damage to the p VN. After glutamate receptor antagonist kynurenic acid was injected into the p VN, the protective effects of the chemical stimulation of the p VN were eliminated in rats with UC. After AVpVl receptor antagonist([Deamino-penl, val4, D-Arg8]-vasopressin) was injected into NTS or bilateral chemical damage to NTS, the protective effect of the chemical stimulation of p VN on UC was also eliminated. After chemical stimulation of the p VN, SOD activity increased, MDA content decreased, C-myc protein expression significantly increased, caspase-3 and Apaf-1 protein expression significantly decreased, and IL-6 and IL-17 expression decreased in colon tissues in rats with UC. CONCLUSION: Chemical stimulation of the hypothalamic p VN provides a protective effect against UC injury in rats. Hypothalamic p VN, NTS and vagus nerve play key roles in this process.展开更多
Photocatalytic CO_(2) reduction into valuable chemical fuels is a highly desirable subject in the field of photosynthesis.Nevertheless,the performance of most current photocatalytic CO_(2) reduction catalysts remains ...Photocatalytic CO_(2) reduction into valuable chemical fuels is a highly desirable subject in the field of photosynthesis.Nevertheless,the performance of most current photocatalytic CO_(2) reduction catalysts remains a significant challenge for practical applications.In this study,we present the achievement of anchoring of nickel(Ni)metal sites onto a flexible and stable covalent organic framework(COF-Tp-Azo)for photocatalytic CO_(2) reduction.It is noteworthy that the flexibility of the framework plays a crucial role in improving the adsorption of carbon dioxide,as it minimizes steric hindrance.On incorporating varying amounts of metal active species into the COFs,the resultant COF-Tp-Azo-Nix demonstrates a pronounced influence on the catalytic activity.Specifically,COF-Tp-Azo-Ni0.33 exhibits a high CO production rate of 9742.5μmol g^(−1) h^(−1) with a selectivity as high as 98.8%under visible light irradiation,representing the highest production and selectivity for reported nickel-based COFs.The photoelectrochemical experiments demonstrate that the covalent bonding between Ni^(2+)and COF-Tp-Azo inhibits the recombination of photogenerated charge carriers and facilitates electron migration,thereby enhancing catalytic activity.Additionally,theoretical calculations reveal that the low energy barrier in both the absorption process between Ni-COF-Tp-Azo and CO_(2),as well as the protonation process for Ni-^(*)COO,contributes to the superior catalytic activity of COF-Tp-Azo-Nix.This work opens a new pathway to high-performance catalysts for CO_(2) photoreduction.展开更多
文摘AIM: To investigate the effect and mechanism of stimulation of the hypothalamic paraventricular nucleus with glutamate acid in rats with ulcerative colitis(UC).METHODS: The rats were anesthetized with 10% chloral hydrate via abdominal injection and treated with an equal volume of TNBS + 50% ethanol enema, injected into the upper section of the anus with the tail facing up. Colonic damage scores were calculated after injecting a certain dose of glutamic acid into the paraventricular nucleus(p VN), and the effect of the nucleus tractus solitarius(NTS) and vagus nerve in alleviating UC injury through chemical stimulation of the p VN was observed in rats. Expression changes of C-myc, Apaf-1, caspase-3, interleukin(IL)-6, and IL-17 during the protection against UC injury through chemical stimulation of the p VN in rats were detected by Western blot. Malondialdehyde(MDA) content and superoxide dismutase(SOD) activity in colon tissues of rats were measured by colorimetric methods. RESULTS: Chemical stimulation of the PVN significantly reduced UC in rats in a dose-dependent manner. The protective effects of the chemical stimulationof the p VN on rats with UC were eliminated after chemical damage to the p VN. After glutamate receptor antagonist kynurenic acid was injected into the p VN, the protective effects of the chemical stimulation of the p VN were eliminated in rats with UC. After AVpVl receptor antagonist([Deamino-penl, val4, D-Arg8]-vasopressin) was injected into NTS or bilateral chemical damage to NTS, the protective effect of the chemical stimulation of p VN on UC was also eliminated. After chemical stimulation of the p VN, SOD activity increased, MDA content decreased, C-myc protein expression significantly increased, caspase-3 and Apaf-1 protein expression significantly decreased, and IL-6 and IL-17 expression decreased in colon tissues in rats with UC. CONCLUSION: Chemical stimulation of the hypothalamic p VN provides a protective effect against UC injury in rats. Hypothalamic p VN, NTS and vagus nerve play key roles in this process.
基金the National Natural Science Foundation of China(Grant No.51604155)the Foundation of the Jiangsu Education Committee(20KJB150006)for financial supportsupported by the outstanding scientific and technological innovation teams in the colleges and univer-sities of Jiangsu province.
文摘Photocatalytic CO_(2) reduction into valuable chemical fuels is a highly desirable subject in the field of photosynthesis.Nevertheless,the performance of most current photocatalytic CO_(2) reduction catalysts remains a significant challenge for practical applications.In this study,we present the achievement of anchoring of nickel(Ni)metal sites onto a flexible and stable covalent organic framework(COF-Tp-Azo)for photocatalytic CO_(2) reduction.It is noteworthy that the flexibility of the framework plays a crucial role in improving the adsorption of carbon dioxide,as it minimizes steric hindrance.On incorporating varying amounts of metal active species into the COFs,the resultant COF-Tp-Azo-Nix demonstrates a pronounced influence on the catalytic activity.Specifically,COF-Tp-Azo-Ni0.33 exhibits a high CO production rate of 9742.5μmol g^(−1) h^(−1) with a selectivity as high as 98.8%under visible light irradiation,representing the highest production and selectivity for reported nickel-based COFs.The photoelectrochemical experiments demonstrate that the covalent bonding between Ni^(2+)and COF-Tp-Azo inhibits the recombination of photogenerated charge carriers and facilitates electron migration,thereby enhancing catalytic activity.Additionally,theoretical calculations reveal that the low energy barrier in both the absorption process between Ni-COF-Tp-Azo and CO_(2),as well as the protonation process for Ni-^(*)COO,contributes to the superior catalytic activity of COF-Tp-Azo-Nix.This work opens a new pathway to high-performance catalysts for CO_(2) photoreduction.
