Advanced oxidation processes(AOPs)governed by peroxide activation to produce highly oxidative active species have been extensively explored for environmental remediation.Nevertheless,the low diffusion rates,inadequate...Advanced oxidation processes(AOPs)governed by peroxide activation to produce highly oxidative active species have been extensively explored for environmental remediation.Nevertheless,the low diffusion rates,inadequate interactions of the reactants,and limited active site exposure hinder treatment efficiency.Porous carbocatalysts with high specific surface area,tunable pore size,and programmable active sites demonstrate outstanding performance in activating diverse types of peroxides to generate active species for treatment of aqueous organic pollutants.The pore-rich structures enhance reaction kinetics for peroxide activation by facilitating diffusion of the reactants and their interactions.Additionally,the structural flexibility of porous structures favors the accommodation of highly dispersed metal species and allows for precise tuning of the microenvironment around the active sites,which further enhances the catalytic activity.This review critically summarizes the recent research progress in the applications of engineered porous carbocatalysts for peroxide activation and outlines the prevailing pore construction methods in carbocatalysts.Moreover,engineering strategies to regulate the mass transfer efficiency and fine-tune the microenvironment around the active sites are systematically addressed to enhance their catalytic peroxide activation performances.Challenges and future research opportunities pertaining to the design,optimization,mechanistic investigation,and practical application of porous carbocatalysts in peroxide activation are also proposed.展开更多
CdS photocatalysts have broad application prospects in environmental purification,energy conversion,and organic synthesis.However,their practical use is often hindered by the rapid recombination of photo-generated ele...CdS photocatalysts have broad application prospects in environmental purification,energy conversion,and organic synthesis.However,their practical use is often hindered by the rapid recombination of photo-generated electron-hole pairs,which limits their efficiency on various reactions.Controlling morphological structures and crystal facets engineering are effective methods to enhance the photocatalytic performance of CdS.In this work,two different forms of CdS photocatalysts were synthesized by a hydrothermal method,namely nanoflower-shaped (CdS-NF) and nanorod-shaped (CdS-NR) for hydrogen peroxide (H_(2)O_(2)) production.The exposed crystal planes of CdS-NF are mainly (0 0 2) planes,while the accesible crystal planes of CdS-NR are notablly (1 0 1) planes.Notably,the photocatalytic hydrogen peroxide production yield of CdS-NR was high at 1225.13 μmol·h^(−1)·g^(−1),which is 1.78 times higher than the H_(2)O_(2) generation rate of CdS-NF.Moreover,through free radical capture experiments and DFT calculations,the reaction pathway was further explored.Both different configurations of cadmium sulfide based photocatalysts conform to the reaction mechanism of oxygen reduction as the main and water oxidation as the auxiliary.展开更多
Dynamic melt modification of polyethylene via the direct grafting of peroxide fragments shows promise for the development of processable functionalized materials.In this study,four linear low-density polyethylenes(LLD...Dynamic melt modification of polyethylene via the direct grafting of peroxide fragments shows promise for the development of processable functionalized materials.In this study,four linear low-density polyethylenes(LLDPEs)with comparable molecular weights but different short-chain branch(SCB)contents(ranging of 5-66 per 1000 carbon atoms)were modified via dynamic melt mixing using 2 wt% benzoyl peroxide at 145℃ and 50 r/min for 30 min.The influence of SCB content on the processability and structure of the resulting products was systematically investigated.All modified products exhibited good melt processability with melt flow rates(MFR)ranging from 0.46 g/10min to 1.07 g/10min.Products derived from low-SCB LLDPEs showed a lower MFR,higher cross-linking content,a larger number of long-chain branches,and a higher degree of benzoyl grafting.In contrast,those produced from high-SCB LLDPEs exhibited improved processability,reduced cross-linking,fewer long-chain branches,and lower benzoyl grafting levels.A detailed structural investigation of the soluble and insoluble fractions,which were separated using trichlorobenzene fractionation,was conducted to analyze the structural features of various modified products and demonstrate that the SCB content(i.e.,tertiary carbon density)significantly influences radical coupling during dynamic modification.Elevated tertiary carbon density,by introducing greater steric hindrance,suppresses radical coupling during dynamic modification,thereby reducing the efficiency of both crosslinking and peroxide fragment grafting.These findings provide new insights into the structure-reactivity relationships in peroxide-induced polyethylene modification and lay the foundation for tailoring material properties via dynamic processing.展开更多
Colorectal cancer(CRC), one of the leading causes of cancer-related mortality globally, urgently requires complementary and alternative therapies. Ferroptosis, an iron-dependent form of regulated cell death driven by ...Colorectal cancer(CRC), one of the leading causes of cancer-related mortality globally, urgently requires complementary and alternative therapies. Ferroptosis, an iron-dependent form of regulated cell death driven by lipid peroxidation, has emerged as a promising anticancer strategy. Dendrobium officinale(D. officinale), a renowned traditional Chinese medicinal herb, is widely used in several Asian countries for its nutritional and therapeutic benefits.Although D. officinale has demonstrated anti-tumor effects, the molecular mechanisms underlying its action against CRC remain incompletely characterized. This study aimed to elucidate the role of D. officinale in suppressing CRC through the induction of ferroptosis and its regulatory effects on glutathione peroxidase 4(GPX4), a key suppressor of ferroptosis. In vitro assays were conducted using HCT116 and SW480 CRC cell lines, and in vivo efficacy was evaluated in BALB/c nude mice bearing CRC xenografts. D. officinale significantly reduced CRC cell viability and proliferation in vitro and suppressed tumor growth in vivo. Induction of ferroptosis was evidenced by elevated levels of Fe^(2+), malondialdehyde(MDA), and lipid peroxidation, along with a depleted glutathione/oxidized glutathione disulfide(GSH/GSSG) ratio. Notably, these effects were reversed by ferroptosis inhibitors, including ferrostatin-1(Fer-1) and deferoxamine. Consistently, D. officinale markedly downregulated GPX4 expression. Overexpression of GPX4 rescued D. officinale-induced ferroptosis, whereas GPX4 silencing exacerbated this effect. D. officinale suppresses CRC by triggering GPX4-dependent ferroptosis,providing a novel, naturally derived therapeutic approach. These findings bridge traditional medicine and modern oncology, establishing a foundation for developing targeted CRC treatments.展开更多
基金supports from the National Natural Science Foundation of China(Nos.22478426 and 22278436)Young Elite Scientists Sponsorship Program by BAST(No.1101020370359)Science Foundation of China University of Petroleum,Beijing(No.2462021QNXZ009)。
文摘Advanced oxidation processes(AOPs)governed by peroxide activation to produce highly oxidative active species have been extensively explored for environmental remediation.Nevertheless,the low diffusion rates,inadequate interactions of the reactants,and limited active site exposure hinder treatment efficiency.Porous carbocatalysts with high specific surface area,tunable pore size,and programmable active sites demonstrate outstanding performance in activating diverse types of peroxides to generate active species for treatment of aqueous organic pollutants.The pore-rich structures enhance reaction kinetics for peroxide activation by facilitating diffusion of the reactants and their interactions.Additionally,the structural flexibility of porous structures favors the accommodation of highly dispersed metal species and allows for precise tuning of the microenvironment around the active sites,which further enhances the catalytic activity.This review critically summarizes the recent research progress in the applications of engineered porous carbocatalysts for peroxide activation and outlines the prevailing pore construction methods in carbocatalysts.Moreover,engineering strategies to regulate the mass transfer efficiency and fine-tune the microenvironment around the active sites are systematically addressed to enhance their catalytic peroxide activation performances.Challenges and future research opportunities pertaining to the design,optimization,mechanistic investigation,and practical application of porous carbocatalysts in peroxide activation are also proposed.
基金support from Natural Science Foundation of Shandong Province(ZR2022MB049,ZR2021MB104)the National Natural Science Foundation of China(22078174).
文摘CdS photocatalysts have broad application prospects in environmental purification,energy conversion,and organic synthesis.However,their practical use is often hindered by the rapid recombination of photo-generated electron-hole pairs,which limits their efficiency on various reactions.Controlling morphological structures and crystal facets engineering are effective methods to enhance the photocatalytic performance of CdS.In this work,two different forms of CdS photocatalysts were synthesized by a hydrothermal method,namely nanoflower-shaped (CdS-NF) and nanorod-shaped (CdS-NR) for hydrogen peroxide (H_(2)O_(2)) production.The exposed crystal planes of CdS-NF are mainly (0 0 2) planes,while the accesible crystal planes of CdS-NR are notablly (1 0 1) planes.Notably,the photocatalytic hydrogen peroxide production yield of CdS-NR was high at 1225.13 μmol·h^(−1)·g^(−1),which is 1.78 times higher than the H_(2)O_(2) generation rate of CdS-NF.Moreover,through free radical capture experiments and DFT calculations,the reaction pathway was further explored.Both different configurations of cadmium sulfide based photocatalysts conform to the reaction mechanism of oxygen reduction as the main and water oxidation as the auxiliary.
基金financially supported by the Science and Technology Project of PetroChina Company Limited,China(No.2022DJ6314)the National Natural Science Foundation of China(No.52173056)。
文摘Dynamic melt modification of polyethylene via the direct grafting of peroxide fragments shows promise for the development of processable functionalized materials.In this study,four linear low-density polyethylenes(LLDPEs)with comparable molecular weights but different short-chain branch(SCB)contents(ranging of 5-66 per 1000 carbon atoms)were modified via dynamic melt mixing using 2 wt% benzoyl peroxide at 145℃ and 50 r/min for 30 min.The influence of SCB content on the processability and structure of the resulting products was systematically investigated.All modified products exhibited good melt processability with melt flow rates(MFR)ranging from 0.46 g/10min to 1.07 g/10min.Products derived from low-SCB LLDPEs showed a lower MFR,higher cross-linking content,a larger number of long-chain branches,and a higher degree of benzoyl grafting.In contrast,those produced from high-SCB LLDPEs exhibited improved processability,reduced cross-linking,fewer long-chain branches,and lower benzoyl grafting levels.A detailed structural investigation of the soluble and insoluble fractions,which were separated using trichlorobenzene fractionation,was conducted to analyze the structural features of various modified products and demonstrate that the SCB content(i.e.,tertiary carbon density)significantly influences radical coupling during dynamic modification.Elevated tertiary carbon density,by introducing greater steric hindrance,suppresses radical coupling during dynamic modification,thereby reducing the efficiency of both crosslinking and peroxide fragment grafting.These findings provide new insights into the structure-reactivity relationships in peroxide-induced polyethylene modification and lay the foundation for tailoring material properties via dynamic processing.
基金supported by the Department of Education of Guangdong Province (No.2023KTSCX024)the Project of Traditional Chinese Medicine Bureau of Guangdong Province(No.20251091)+3 种基金the Joint Funds of the National Natural Science Foundation of China (No.U22A20368)the Key-Area Research and Development Program of Guangdong Province (No.2020B1111100004)Guangdong Basic and Applied Basic Research Foundation (No.2020B1515130005)Shenzhen Baoan District Science and Technology Innovation Bureau Project(Nos.2022JD226 and 2023JD252)。
文摘Colorectal cancer(CRC), one of the leading causes of cancer-related mortality globally, urgently requires complementary and alternative therapies. Ferroptosis, an iron-dependent form of regulated cell death driven by lipid peroxidation, has emerged as a promising anticancer strategy. Dendrobium officinale(D. officinale), a renowned traditional Chinese medicinal herb, is widely used in several Asian countries for its nutritional and therapeutic benefits.Although D. officinale has demonstrated anti-tumor effects, the molecular mechanisms underlying its action against CRC remain incompletely characterized. This study aimed to elucidate the role of D. officinale in suppressing CRC through the induction of ferroptosis and its regulatory effects on glutathione peroxidase 4(GPX4), a key suppressor of ferroptosis. In vitro assays were conducted using HCT116 and SW480 CRC cell lines, and in vivo efficacy was evaluated in BALB/c nude mice bearing CRC xenografts. D. officinale significantly reduced CRC cell viability and proliferation in vitro and suppressed tumor growth in vivo. Induction of ferroptosis was evidenced by elevated levels of Fe^(2+), malondialdehyde(MDA), and lipid peroxidation, along with a depleted glutathione/oxidized glutathione disulfide(GSH/GSSG) ratio. Notably, these effects were reversed by ferroptosis inhibitors, including ferrostatin-1(Fer-1) and deferoxamine. Consistently, D. officinale markedly downregulated GPX4 expression. Overexpression of GPX4 rescued D. officinale-induced ferroptosis, whereas GPX4 silencing exacerbated this effect. D. officinale suppresses CRC by triggering GPX4-dependent ferroptosis,providing a novel, naturally derived therapeutic approach. These findings bridge traditional medicine and modern oncology, establishing a foundation for developing targeted CRC treatments.
