The study of atomically dispersed metal-nitrogen electrocatalysts is still limited in terms of understanding their catalytic mechanism because of the inability to precisely regulate the coordination number and type of...The study of atomically dispersed metal-nitrogen electrocatalysts is still limited in terms of understanding their catalytic mechanism because of the inability to precisely regulate the coordination number and type of N in combination with the metal elements.Inspired by the high catalytic activity and selectivity of natural enzymes,herein,we have designed and fabricated ultrathin carbon nanosheet-supported Mn single-atom catalysts(SACs)with a precise pyrrole-type Mn-N4(PT-MnN4)configuration using a bio-mimicking strategy.The PT-MnN4 SACs display outstanding oxygen reduction reaction(ORR)activity,with a half-wave potential(E_(1/2))of 0.88 V(vs.revisible hydrogen electrode[RHE])and extremely high stability in alkaline media.Moreover,superior ORR activities are also obtained,E_(1/2) of 0.73 V and 0.63 V in acid and neutral electrolytes,respectively,indicating the efficient pH-universal ORR performances.The assembled zinc-air battery using the PT-MnN4 SACs as air cathodes exhibits a high peak power density(175 mW cm^(−2))and long-term stability up to 150 h,implying its promising application in metal-air batteries.This study has paved the way toward the rational design and precise regulation of single-atom electrocatalysts.展开更多
Cadmium(Cd)pollution poses a serious threat to plant growth and yield.Nanomaterials have shown great application potential for alleviation of Cd toxicity to plants.In this study,we applied graphitic carbon nitride nan...Cadmium(Cd)pollution poses a serious threat to plant growth and yield.Nanomaterials have shown great application potential for alleviation of Cd toxicity to plants.In this study,we applied graphitic carbon nitride nanosheets(g-C_(3)N_(4)NSs)for alleviation of Cd-toxicity to soybean(Glycine max L.).The g-C_(3)N_(4)NSs supplementation significantly improved plant growth and reduced oxidative damage in the Cd-toxicated soybean seedlings through hydroponic culture.Particularly,the g-C_(3)N_(4)NSs dynamically regulated the root cell wall(RCW)components by increasing pectin content and modifying its demethylation via enhancing pectin methylesterase(PME)activity,therefore greatly enhanced stronger RCW-Cd retention(up to 82.8%)and reduced Cd migration to the shoot.Additionally,the g-C_(3)N_(4)NSs reversed the Cd-induced chlorosis,increased photosynthetic efficiency because of enhancement in F_v/F_mration,Y(Ⅱ)and sugars content.These results provide new insights into the alleviation of Cd toxicity to plants by g-C_(3)N_(4)NSs,and shed light on the application of low-cost and environmental-friendly carbon-based NMs for alleviating heavy metal toxicity to plants.展开更多
Objective：To review recent research advances on tau,a major player in Alzheimer＇s disease （AD） pathogenesis,a biomarker for AD onset,and potential target for AD therapy.Data Sources：This review was based on a com...Objective：To review recent research advances on tau,a major player in Alzheimer＇s disease （AD） pathogenesis,a biomarker for AD onset,and potential target for AD therapy.Data Sources：This review was based on a comprehensive search using online literature databases,including PubMed,Web of Science,and Google Scholar.Study Selection：Literature search was based on the following keywords：Alzheimer＇s disease,tau protein,biomarker,cerebrospinal fluid （CSF）,therapeutics,plasma,imaging,propagation,spreading,seeding,prion,conformational templating,and posttranslational modification.Relevant articles were carefully reviewed,with no exclusions applied to study design and publication type.Results：Amyloid plaques enriched with extracellular amyloid beta （Aβ） and intracellular neurofibrillary tangles comprised of hyperphosphorylated tau proteins are the two main pathological hallmarks ofAD.Although the Aβ hypothesis has dominated AD research for many years,clinical Aβ-targeting strategies have consistently failed to effectively treat AD or prevent AD onset.The research focus in AD has recently shifted to the role oftau in AD.In addition to phosphorylation,tau is acetylated and proteolytically cleaved,which also contribute to its physiological and pathological functions.Emerging evidence characterizing pathological tau propagation and spreading provides new avenues for research into the molecular and cellular mechanisms underlying AD pathogenesis.Techniques to detect tau at minute levels in CSF and blood have been developed,and improved tracers have facilitated tau imaging in the brain.These advances have potential to accurately determine tau levels at early diagnostic stages in AD.Given that tau is a potential therapeutic target,anti-tau immunotherapy may potentially be a viable treatment strategy in AD intervention.Conclusion：Detecting changes in tau and targeting tau pathology represent a promising lead in the diagnosis and treatment of AD.展开更多
Objective:To study the oxidative stress and antioxidative response of Cinnamomum camphora seedlings exposed to nitrogen dioxide (NO2) fumigation.Methods:Measurements were made up of the growth,chlorophyll content,chlo...Objective:To study the oxidative stress and antioxidative response of Cinnamomum camphora seedlings exposed to nitrogen dioxide (NO2) fumigation.Methods:Measurements were made up of the growth,chlorophyll content,chlorophyll fluorescence,antioxidant system and lipid peroxidation of one-year-old C.camphora seedlings exposed to NO2 (0.1,0.5,and 4 μl/L) fumigation in open top chambers over a period of 60 d.Results:After the first 30 d,0.5 and 4.0 μl/L NO2 showed insignificant effects on the growth of C.camphora seedlings.However,exposure to 0.5 and 4.0 μl/L NO2 for 15 d significantly reduced their chlorophyll content (P<0.05),enhanced their malondialdehyde (MDA) content and superoxide dismutase (SOD) activity (P<0.05),and also significantly reduced the maximal quantum yield of PSII in the dark [the ratio of variable fluorescence to maximal fluorescence (Fv/Fm)] (P<0.05).In the latter 30 d,0.5 μl/L NO2 showed a positive effect on the vitality of the seedlings,which was reflected by a recovery in the ratio of Fv/Fm and chlorophyll content,and obviously enhanced growth,SOD activity,ascorbate (AsA) content and glutathione reductase (GR) activity (P<0.05);4.0 μl/L NO2 then showed a negative effect,indicated by significant reductions in chlorophyll content and the ratio of Fv/Fm,and inhibited growth (P<0.05).Conclusion:The results suggest adaptation of C.camphora seedlings to 60-d exposure to 0.1 and 0.5 μl/L NO2,but not to 60-d exposure to 4.0 μl/L NO2.C.camphora seedlings may protect themselves from injury by strengthening their antioxidant system in response to NO2-induced oxidative stress.展开更多
Background： Amyloid β （Aβ） has been established as a key factor for the pathological changes in the brains of patients with Alzheimer＇s disease （AD）, and cellular senescence is closely associated with aging an...Background： Amyloid β （Aβ） has been established as a key factor for the pathological changes in the brains of patients with Alzheimer＇s disease （AD）, and cellular senescence is closely associated with aging and cognitive impairment. However, it remains blurred whether, in theAD brains, Aβ accelerates the neuronal senescence and whether this senescence, in turn, impairs the cognitive function. This study aimed to explore the expression of senescence-associated genes in the hippocampal tissue from young to aged 5XFAD mice and their age-matched wild type （WT） mice to determine whether senescent neurons are present in the transgenic AD mouse model. Methods： The 5XFAD mice and age-matched wild type mice, both raised from 1 to 18 months, were enrolled in the study. The senescence-associated genes in the hippocampus were analyzed and differentially expressed genes （DEGs） were screened by quantitative real-time polymerase chain reaction. Cognitive perfom3ance of the mice was evaluated by Y-maze and Morris water maze tests. Oligomeric Aβ（oAβ） （1-42） was applied to culture primary neurons to simulate the in vivo manifestation. Aging-related proteins were detected by Western blotting analysis and immunofluorescence. Results： In 5XFAD mice, of all the DEGs, the senescence-associated marker p16 was most significantly increased, even at the early age. It was mainly localized in neurons, with a marginal expression in astrocytes （labeled as glutamine synthetase）, nil expression in activated microglia （labeled as lba1）, and negatively correlated with the spatial cognitive impairments of 5XFAD mice. oAβ （1-42） induced the production of senescence-related protein p1 6, but not p53 in vitro, which was in line with the in vivo manifestation. Conclusions： oAβ-accelerated neuronal senescence may be associated with the cognitive impairment in 5XFAD mice. Senescence-associated marker p16 can serve as an indicator to estimate the cognitive prognosis for A D population.展开更多
Background：Early diagnosis assumes a vital role in an effective treatment of Alzheimer＇s disease （AD）.Most of the current studies can only make anAD diagnosis after the manifestation of typical clinical symptoms.T...Background：Early diagnosis assumes a vital role in an effective treatment of Alzheimer＇s disease （AD）.Most of the current studies can only make anAD diagnosis after the manifestation of typical clinical symptoms.The present study aimed to investigate typical and other biomarkers of AD to find a possible early biomarker.Methods：A total of 14 5XFAD mice （at 3 and 6 months old）,with 14 age-matched wild-type （WT） mice as control,were enrolled in this case-control study.Morris water maze test was performed to evaluate the cognitive function;buried food pellet test and olfactory maze test were employed to investigate the olfactory function;immunofluorescence to detect amyloid deposition and positron emission tomography to examine 2-deoxy-2-（18F） fluoro-D-glucose （[18F]-FDG） uptake in the hippocampus and cerebral cortex.Results：With the increasing age,cognitive performance （P =0.0262） and olfactory function were significantly deteriorated （day 1 P =0.0012,day 2 P =0.0031,day 3 P =0.0160,respectively） and the （18F）-FDG uptake was markedly decreased in multi-cerebral regions including the olfactory bulb （P 〈 0.0001）,hippocampus （P =0.0121）,and cerebral cortex （P 〈 0.0001）.Of note,in 3-month-old 5XFAD mice,a significant decline of （18F）-FDG uptake in the olfactory bulb was found when compared with that of age-matched WT mice （P =0.023） while no significant difference was present when the uptakes in other cerebral regions were compared.Conclusions：The decline of （18F）-FDG uptake in the olfactory bulb occurs earlier than other incidents,serving as an earlier in vivo biological marker of AD in 5XFAD mice and making early diagnosis of AD possibly.展开更多
Biochar and biochar-based materials have been studied extensively in multidisciplinary areas because of their outstanding physicochemical properties.In this review article,biochar and biochar-based materials in the re...Biochar and biochar-based materials have been studied extensively in multidisciplinary areas because of their outstanding physicochemical properties.In this review article,biochar and biochar-based materials in the removal of environmental pollutants,hydrogen generation and carbon dioxide capture were summarized and compared.The interaction mechanisms were discussed from the experimental results and characterization analysis.The high porous structures,active surface sites,(co)doping of single metals/nonmetals,and incorporation of metal oxides or other materials improved the high activity of biochar-based materials in their applications.However,there are still some challenges such as:(1)the fact that H_(2) generation with high selectivity or the produced syngas to meet the real application requirement in industrial is the main challenge in H_(2) production;(2)the fact that the selective capture of CO_(2) with high stability,high adsorption capacity and recyclability at low-cost should be considered and focused on;(3)the sorption-(photo)degradation of the organic chemicals;and(4)the fact that the sorption-reduction-extraction/solidification of metals/radionuclides are efficient methods for the elimination of environmental pollutants.In the end,the perspectives,challenges and possible techniques for biochar-based materials’real application in future were described.展开更多
基金support from the Independent Designing Scientific Research Project of Zhejiang Normal University(2020ZS03)the Zhejiang Provincial Ten Thousand Talent Program(2017R52043)+1 种基金support from the Zhejiang Province Basic Public Welfare Research Project(LGF19B070006)supported by the National Natural Science Foundation of China(No.21775138).
文摘The study of atomically dispersed metal-nitrogen electrocatalysts is still limited in terms of understanding their catalytic mechanism because of the inability to precisely regulate the coordination number and type of N in combination with the metal elements.Inspired by the high catalytic activity and selectivity of natural enzymes,herein,we have designed and fabricated ultrathin carbon nanosheet-supported Mn single-atom catalysts(SACs)with a precise pyrrole-type Mn-N4(PT-MnN4)configuration using a bio-mimicking strategy.The PT-MnN4 SACs display outstanding oxygen reduction reaction(ORR)activity,with a half-wave potential(E_(1/2))of 0.88 V(vs.revisible hydrogen electrode[RHE])and extremely high stability in alkaline media.Moreover,superior ORR activities are also obtained,E_(1/2) of 0.73 V and 0.63 V in acid and neutral electrolytes,respectively,indicating the efficient pH-universal ORR performances.The assembled zinc-air battery using the PT-MnN4 SACs as air cathodes exhibits a high peak power density(175 mW cm^(−2))and long-term stability up to 150 h,implying its promising application in metal-air batteries.This study has paved the way toward the rational design and precise regulation of single-atom electrocatalysts.
基金financial support from the National Natural Science Foundation of China(Nos.30800705,31101599)the Natural Science Foundation of Zhejiang Provincial(Nos.LY18C150007,LY15C150004)+1 种基金Key Research and Development Projects of Social Development of Jinhua Science and Technology Program(No.2021C22750)the Zhejiang Provincial Key Laboratory of Subtropic Soil and Plant Nutrition,China。
文摘Cadmium(Cd)pollution poses a serious threat to plant growth and yield.Nanomaterials have shown great application potential for alleviation of Cd toxicity to plants.In this study,we applied graphitic carbon nitride nanosheets(g-C_(3)N_(4)NSs)for alleviation of Cd-toxicity to soybean(Glycine max L.).The g-C_(3)N_(4)NSs supplementation significantly improved plant growth and reduced oxidative damage in the Cd-toxicated soybean seedlings through hydroponic culture.Particularly,the g-C_(3)N_(4)NSs dynamically regulated the root cell wall(RCW)components by increasing pectin content and modifying its demethylation via enhancing pectin methylesterase(PME)activity,therefore greatly enhanced stronger RCW-Cd retention(up to 82.8%)and reduced Cd migration to the shoot.Additionally,the g-C_(3)N_(4)NSs reversed the Cd-induced chlorosis,increased photosynthetic efficiency because of enhancement in F_v/F_mration,Y(Ⅱ)and sugars content.These results provide new insights into the alleviation of Cd toxicity to plants by g-C_(3)N_(4)NSs,and shed light on the application of low-cost and environmental-friendly carbon-based NMs for alleviating heavy metal toxicity to plants.
基金This work was supported by grants from the National Natural Science Foundation of China （No. 81671352, 91232709）, the National Key Project of Research and Development Plan （No. 2016YFC1306404）, the National Institute of Health （No. R21 AG048519, R01 AG021173, R01 AG038710, R01 AG044420, R01 NS046673, RF1 AG056130, and RF1 AG056114）, the Tanz Family Fund as well as scholarship from China Scholarship Council （No. 201608350068）.
文摘Objective：To review recent research advances on tau,a major player in Alzheimer＇s disease （AD） pathogenesis,a biomarker for AD onset,and potential target for AD therapy.Data Sources：This review was based on a comprehensive search using online literature databases,including PubMed,Web of Science,and Google Scholar.Study Selection：Literature search was based on the following keywords：Alzheimer＇s disease,tau protein,biomarker,cerebrospinal fluid （CSF）,therapeutics,plasma,imaging,propagation,spreading,seeding,prion,conformational templating,and posttranslational modification.Relevant articles were carefully reviewed,with no exclusions applied to study design and publication type.Results：Amyloid plaques enriched with extracellular amyloid beta （Aβ） and intracellular neurofibrillary tangles comprised of hyperphosphorylated tau proteins are the two main pathological hallmarks ofAD.Although the Aβ hypothesis has dominated AD research for many years,clinical Aβ-targeting strategies have consistently failed to effectively treat AD or prevent AD onset.The research focus in AD has recently shifted to the role oftau in AD.In addition to phosphorylation,tau is acetylated and proteolytically cleaved,which also contribute to its physiological and pathological functions.Emerging evidence characterizing pathological tau propagation and spreading provides new avenues for research into the molecular and cellular mechanisms underlying AD pathogenesis.Techniques to detect tau at minute levels in CSF and blood have been developed,and improved tracers have facilitated tau imaging in the brain.These advances have potential to accurately determine tau levels at early diagnostic stages in AD.Given that tau is a potential therapeutic target,anti-tau immunotherapy may potentially be a viable treatment strategy in AD intervention.Conclusion：Detecting changes in tau and targeting tau pathology represent a promising lead in the diagnosis and treatment of AD.
基金Project supported by Zhejiang Keystone Projects (No.2005C22056)the Zhejiang Provincial Natural Science Foundation of China (No.Y5080011)
文摘Objective:To study the oxidative stress and antioxidative response of Cinnamomum camphora seedlings exposed to nitrogen dioxide (NO2) fumigation.Methods:Measurements were made up of the growth,chlorophyll content,chlorophyll fluorescence,antioxidant system and lipid peroxidation of one-year-old C.camphora seedlings exposed to NO2 (0.1,0.5,and 4 μl/L) fumigation in open top chambers over a period of 60 d.Results:After the first 30 d,0.5 and 4.0 μl/L NO2 showed insignificant effects on the growth of C.camphora seedlings.However,exposure to 0.5 and 4.0 μl/L NO2 for 15 d significantly reduced their chlorophyll content (P<0.05),enhanced their malondialdehyde (MDA) content and superoxide dismutase (SOD) activity (P<0.05),and also significantly reduced the maximal quantum yield of PSII in the dark [the ratio of variable fluorescence to maximal fluorescence (Fv/Fm)] (P<0.05).In the latter 30 d,0.5 μl/L NO2 showed a positive effect on the vitality of the seedlings,which was reflected by a recovery in the ratio of Fv/Fm and chlorophyll content,and obviously enhanced growth,SOD activity,ascorbate (AsA) content and glutathione reductase (GR) activity (P<0.05);4.0 μl/L NO2 then showed a negative effect,indicated by significant reductions in chlorophyll content and the ratio of Fv/Fm,and inhibited growth (P<0.05).Conclusion:The results suggest adaptation of C.camphora seedlings to 60-d exposure to 0.1 and 0.5 μl/L NO2,but not to 60-d exposure to 4.0 μl/L NO2.C.camphora seedlings may protect themselves from injury by strengthening their antioxidant system in response to NO2-induced oxidative stress.
基金We would like to thank teacher Hong-Zhi Huang from College of Foreign Languages of Fujian Medical University for the kindly help of text modifications and retouching of this paper. This study was supported by grants from National Natural Science Fotmdation of China （No. 81200991 and No. 81571257）, Fujian Provincial Natural Science Foundation （No. 2015J01398）, Fujian Provincial New Century Excellent Talents Support Program, China （JA13131）, and Young and Middle-aged Talent Training Key Project in Health System of Fujian Province （2014-ZQN-ZD- 11）.
文摘Background： Amyloid β （Aβ） has been established as a key factor for the pathological changes in the brains of patients with Alzheimer＇s disease （AD）, and cellular senescence is closely associated with aging and cognitive impairment. However, it remains blurred whether, in theAD brains, Aβ accelerates the neuronal senescence and whether this senescence, in turn, impairs the cognitive function. This study aimed to explore the expression of senescence-associated genes in the hippocampal tissue from young to aged 5XFAD mice and their age-matched wild type （WT） mice to determine whether senescent neurons are present in the transgenic AD mouse model. Methods： The 5XFAD mice and age-matched wild type mice, both raised from 1 to 18 months, were enrolled in the study. The senescence-associated genes in the hippocampus were analyzed and differentially expressed genes （DEGs） were screened by quantitative real-time polymerase chain reaction. Cognitive perfom3ance of the mice was evaluated by Y-maze and Morris water maze tests. Oligomeric Aβ（oAβ） （1-42） was applied to culture primary neurons to simulate the in vivo manifestation. Aging-related proteins were detected by Western blotting analysis and immunofluorescence. Results： In 5XFAD mice, of all the DEGs, the senescence-associated marker p16 was most significantly increased, even at the early age. It was mainly localized in neurons, with a marginal expression in astrocytes （labeled as glutamine synthetase）, nil expression in activated microglia （labeled as lba1）, and negatively correlated with the spatial cognitive impairments of 5XFAD mice. oAβ （1-42） induced the production of senescence-related protein p1 6, but not p53 in vitro, which was in line with the in vivo manifestation. Conclusions： oAβ-accelerated neuronal senescence may be associated with the cognitive impairment in 5XFAD mice. Senescence-associated marker p16 can serve as an indicator to estimate the cognitive prognosis for A D population.
基金grants from the National Natural Science Foundation of China （No. 81171216 and No. 91232709）, and the Key Clinical Specialty Discipline Construction Program of Fujian and Nation, China.
文摘Background：Early diagnosis assumes a vital role in an effective treatment of Alzheimer＇s disease （AD）.Most of the current studies can only make anAD diagnosis after the manifestation of typical clinical symptoms.The present study aimed to investigate typical and other biomarkers of AD to find a possible early biomarker.Methods：A total of 14 5XFAD mice （at 3 and 6 months old）,with 14 age-matched wild-type （WT） mice as control,were enrolled in this case-control study.Morris water maze test was performed to evaluate the cognitive function;buried food pellet test and olfactory maze test were employed to investigate the olfactory function;immunofluorescence to detect amyloid deposition and positron emission tomography to examine 2-deoxy-2-（18F） fluoro-D-glucose （[18F]-FDG） uptake in the hippocampus and cerebral cortex.Results：With the increasing age,cognitive performance （P =0.0262） and olfactory function were significantly deteriorated （day 1 P =0.0012,day 2 P =0.0031,day 3 P =0.0160,respectively） and the （18F）-FDG uptake was markedly decreased in multi-cerebral regions including the olfactory bulb （P 〈 0.0001）,hippocampus （P =0.0121）,and cerebral cortex （P 〈 0.0001）.Of note,in 3-month-old 5XFAD mice,a significant decline of （18F）-FDG uptake in the olfactory bulb was found when compared with that of age-matched WT mice （P =0.023） while no significant difference was present when the uptakes in other cerebral regions were compared.Conclusions：The decline of （18F）-FDG uptake in the olfactory bulb occurs earlier than other incidents,serving as an earlier in vivo biological marker of AD in 5XFAD mice and making early diagnosis of AD possibly.
基金National Key Research and Development Program of China(2018YFC1900105)National Natural Science Foundation of China(22276054)Beijing Outstanding Young Scientist Program.
文摘Biochar and biochar-based materials have been studied extensively in multidisciplinary areas because of their outstanding physicochemical properties.In this review article,biochar and biochar-based materials in the removal of environmental pollutants,hydrogen generation and carbon dioxide capture were summarized and compared.The interaction mechanisms were discussed from the experimental results and characterization analysis.The high porous structures,active surface sites,(co)doping of single metals/nonmetals,and incorporation of metal oxides or other materials improved the high activity of biochar-based materials in their applications.However,there are still some challenges such as:(1)the fact that H_(2) generation with high selectivity or the produced syngas to meet the real application requirement in industrial is the main challenge in H_(2) production;(2)the fact that the selective capture of CO_(2) with high stability,high adsorption capacity and recyclability at low-cost should be considered and focused on;(3)the sorption-(photo)degradation of the organic chemicals;and(4)the fact that the sorption-reduction-extraction/solidification of metals/radionuclides are efficient methods for the elimination of environmental pollutants.In the end,the perspectives,challenges and possible techniques for biochar-based materials’real application in future were described.
