Silicoaluminophosphate-34(SAPO-34) molecular sieves have important applications in the petrochemical industry as a result of their shape selectivity and suitable acidity. In this work, nanoaggregate SAPO-34 with a lar...Silicoaluminophosphate-34(SAPO-34) molecular sieves have important applications in the petrochemical industry as a result of their shape selectivity and suitable acidity. In this work, nanoaggregate SAPO-34 with a large external surface area was obtained by dissolving pseudoboehmite and tetraethylorthosilicate in an aqueous solution of tetraethylammonium hydroxide and subsequently adding phosphoric acid. After hydrolysis in an alkaline solution, the aluminum and silicon precursors exist as Al(OH)4-and SiO2(OH)-, respectively;this is beneficial for rapid nucleation and the formation of nanoaggregates in the following crystallization process. Additionally, to study the effect of the external surface area and pore size on the catalytic performance of different SAPO-34 structures, the alcoholysis of furfuryl alcohol to ethyl levulinate(EL) was chosen as a model reaction. In a comparison with the traditional cube-like SAPO-34, nanoaggregate SAPO-34 generated a higher yield of 74.1% of EL, whereas that with cube-like SAPO-34 was only 19.9%. Moreover, the stability was remarkably enhanced for nanoaggregate SAPO-34. The greater external surface area and larger number of external surface acid sites are helpful in improving the catalytic performance and avoiding coke deposition.展开更多
The excessive energy of light,especially the invisible rays with lower wavelength,is basically absorbed by retinal pigment epithelium(RPE)and usually causes DNA damage.The molecular mechanism behind DNA damage repair ...The excessive energy of light,especially the invisible rays with lower wavelength,is basically absorbed by retinal pigment epithelium(RPE)and usually causes DNA damage.The molecular mechanism behind DNA damage repair response to this frequent stress in RPE is not clearly understood.In this study,we determined that the Fanconi anemia(FA)pathway was activated in human RPE ARPE-19 cells after ultraviolet(UV)B and C treatment.Moreover,immunoprecipitation(IP)of FANCD2 indicated that denticleless E3 ubiquitin protein ligase homolog(DTL)closely interacted with FANCD2.Knockdown of DTL weakened the activity of the FA pathway in ARPE-19 cells responding to UV treatment.Finally,the DTL promoter was incubated with a biotin-labeled probe and pulled down by streptavidin beads followed by the genomic DNA sonication.p53 was indicated by mass spectrum and further determined by chromatin IP assay.Taken together,our results demonstrated that DTL regulated by p53 could activate the FA pathway for UV-induced DNA damage repair in retinal pigment epithelial cells.展开更多
There are few tumor cell subpopulations with stem cell characteristics in tumor tis-sue,defined as cancer stem cells(CSCs)or cancer stem-like cells(CSLCs),which can recon-struct neoplasms with malignant biological beh...There are few tumor cell subpopulations with stem cell characteristics in tumor tis-sue,defined as cancer stem cells(CSCs)or cancer stem-like cells(CSLCs),which can recon-struct neoplasms with malignant biological behaviors such as invasiveness via self-renewal and unlimited generation.The microenvironment that CsCs depend on consists of various cellular components and corresponding medium components.Among these factors existing at a variety of levels and forms,cytokine networks and numerous signal pathways play an important role in signaling transduction.These factors promote or maintain cancer cell stem-ness,and participate in cancer recurrence,metastasis,and resistance.This review aims to summarize the recent molecular data concerning the multilayered relationship between CsCs and CsC-favorable microenvironments.We also discuss the therapeutic implications of target-ing this synergistic interplay,hoping to give an insight into targeting cancer cell stemness for tumortherapyandprognosis.展开更多
Pyrolysis is an effective technology for treating and utilizing biogas residue.To explore the phosphorus(P)supply capacity of the biochar generated from biogas residue of Eichhornia Crassipes,the P speciation of E.cra...Pyrolysis is an effective technology for treating and utilizing biogas residue.To explore the phosphorus(P)supply capacity of the biochar generated from biogas residue of Eichhornia Crassipes,the P speciation of E.crassipes biogas residue and biomass during pyrolysis(300-700°C)was analyzed by combining sequential chemical extraction,31P nuclear magnetic resonance(NMR)and P K-edge X-ray absorption near edge structure(XANES)spectroscopy.Pyrolysis treatment promoted the conversion of amorphous Ca-P phases in biogas residue and biomass into crystalline hydroxyapatite(HAP)phase,which matched the formation of stable HCl-P pools in the biochar derived from biogas residue(AEBs,22.65-82.04%)and biomass(EBs,13.08-33.52%)in the process of pyrolysis.Moreover,the total P contents in AEBs(19.43-28.92 mg g^(−1))were higher than that of EBs(3.41-5.26 mg g^(−1)),indicating that AEBs had a great P reclamation potential.The P release kinetics from AEBs and EBs in water were evaluated via an incubation experiment for 360 h.The P release from both AEBs and EBs conformed to the pseudo-second order kinetics model(R^(2)>0.93),but their P release behaviors were different.The P release of AEBs conformed to the diffusion-re-adsorption model,while that of EBs accorded with the diffusion-dissolution model.The diffusive gradients in thin-films(DGT)analysis showed that AEBs could significantly increase soil available P content as compared with EBs.Hence,the biochar produced from biogas residue of E.crassipes via pyrolysis has a good application potential as a P fertilizer.展开更多
The bottom ash is increasingly used as a substitute aggregate material in road construction in China,and road salting is the major salt source in groundwater.Continuous rainfall releases soluble salts from the bottom ...The bottom ash is increasingly used as a substitute aggregate material in road construction in China,and road salting is the major salt source in groundwater.Continuous rainfall releases soluble salts from the bottom ash subgrade into the surrounding soil and groundwater,resulting in potential hazards.Different methods were employed to simulate and collect runoff water during rainfall events,including batch leaching test,dynamic leaching test and constant head test,to assess environmental impact of bottom ash as road basement materials under continuous rainfall conditions.This study simulated the seepage of bottom ash backfill roads under different rainfall intensities,rainfall times,and rainfall pH values.A comprehensive sampling and laboratory testing program was undertaken to characterize the environmental impact of soluble salts from bottom ash.The obtained results reveal that the leaching concentrations of Cl^(−)and SO_(4)^(2−)exceed the limit specified in the class V standard of surface water,which are 2.06–2.17 times and 1.08–1.25 times,respectively.By examining the long-term environmental influence under the condition of continuous rainfall,the leaching of Cl^(−)mainly occurs in the early leaching stage,and the maximum leaching concentration reaches 19,700 mg/L.The release concentration of Cl^(−)begins to be lower than the class V standard of surface water when continuous rainfall approaches the total rainfall for 13 months.The cumulative release of Cl^(−)in the bottom ash is 2.8–5.4 mg/g.Both rainfall intensity and rain pH affect the release of Cl^(−).The obtained results derived from the constant head tests indicate that stagnant water caused by rainfall deteriorates the release of soluble salt into the groundwater in only 1 day,especially at the early stage of 12 h.This work provides some basic information about how to minimize damage to the surrounding environment caused by the leaching of salt in bottom ash.展开更多
Diffusion reaction of the labile building block Mg(acacCN)2 (acacCN= 3-cyanoacetylacetonate) with silver salts leads to a series of solvated Mg/Ag bimetallic coordination polymers with composition [Mg(acacCN)aAg...Diffusion reaction of the labile building block Mg(acacCN)2 (acacCN= 3-cyanoacetylacetonate) with silver salts leads to a series of solvated Mg/Ag bimetallic coordination polymers with composition [Mg(acacCN)aAg].solvent. Despite their common stoichiometry, the topology of these polymers depends on the solvent of crystallization. The two-dimensional coordination compound [Mg(acacCN)aAg]-4CHCl3 in space group P]- is obtained as platelet-shaped crystals from a mixture of methanol and chloroform. When kept in the reaction mixture, these thin plates within one week convert to isometric tetrahedral crystals of the 3D network [Mg(acacCN)3Ag]. 2CHC13 in the cubic space group/9213. The transformation reaction proceeds via dissolution and recrystallization. The co-crystallized solvent molecules play an important role for stabilizing the target structure: They subtend Cl...Cl contacts and interact via non- classical C-H.-. O hydrogen bonds with the coordination framework. In the new cubic coordination network, both Mg(II) and Ag(I) adopt octahedral coordination, with unprecedented face-sharing by bridging O atoms of three acetylacetonato moieties. Prolonged standing of [Mg(acacCN)3Ag]-2CHCl3 in the reaction medium leads to further degradation, under formation of [Ag(acacCN)].展开更多
Based on a high level ab initio calculation which is earned out with the multireference configuration interaction method under the aug-cc-pVXZ(AVXZ)basis sets,X=T,Q,5,the accurate potential energy curves(PECs)of the g...Based on a high level ab initio calculation which is earned out with the multireference configuration interaction method under the aug-cc-pVXZ(AVXZ)basis sets,X=T,Q,5,the accurate potential energy curves(PECs)of the ground state X^(1)Σ_(g)^(+)and the first excited state A^(1)Σ_(u)^(+)of Li_(2)are constructed.By fitting the ab initio potential energy points with the MurrellSorbie potential function,the analytic potential energy functions(APEFs)are obtained.The molecular bond length at the equilibnum(R_(e)),the potential well depth(D_(e)),and the spectroscopic constants(B_(e),ω_(e),α_(e),andω_(e)χ_(e))for the X^(1)Σ_(g)^(+)state and the A^(1)Σ_(u)^(+)state are deduced from the APEFs.The vibrational energy levels of the two electronic states are obtained by solving the time-independent Schrodmger equation with the Founer gnd Hamiltonian method.All the spectroscopic constants and the vibrational levels agree well with the experimental results.The Franck-Condon factors(FCFs)corresponding to the transitions from the vibrational level(v’=0)of the ground state to the vibrational levels(v"=0-74)of the first excited state have been calculated.The FCF for the vibronic transition of A^(1)Σ_(u)^(+)(v"=0)←X^(1)Σ_(g)^(+)(v’=0)is the strongest.These PECs and corresponding spectroscopic constants provide reliable theoretical references to both the spectroscopic and the molecular dynamic studies of the Li_(2)dimer.展开更多
Metal recovery from bottom ash was deemed to be significant to achieve a higher stability of bottom ash and recycle valuable extractable metals.In China,the existing rugged industrial production ignores the actual met...Metal recovery from bottom ash was deemed to be significant to achieve a higher stability of bottom ash and recycle valuable extractable metals.In China,the existing rugged industrial production ignores the actual metal distribution and thus fails to exploit the utilization potential of recoverable metals in bottom ash.Based on these findings,this work was proposed to obtain a comprehensive and in-depth study on the recoverability of metals in bottom ash.First,the particle size distribution and elemental composition of the bottom ash were analyzed.Then,complete information on the recoverable metals in bottom ash fractions with different sizes was obtained by washing,sorting,crushing,density separation and XRF(X Ray Fluorescence)analysis.The results showed that the smaller than 5 mm fraction accounted for up to 60%of the bottom ash,and the 5–20 mm fractions accounted for about 15%.The material characterization revealed that the contents of recoverable Fe,stainless steel,Al and Cu in bottom ash were averagely 9.01%,0.136%,0.78%and 0.08%,respectively.About 50%of Fe,68%of Al,61%of Cu,and 22%of stainless steel were distributed in smaller than 10 mm fraction.Particularly,Fe was evenly distributed among 0–2 mm,2–5 mm,5–10 mm fractions,and the content was between 5.41%and 7.5%.Non-magnetic stainless steel was mainly distributed in 20–40 mm and larger than 40 mm fractions.The highest share of Al was present in the fractions between 5 mm and 20 mm,accounting for 48%of the total aluminum.About 45.6%of the Cu was enriched in the 5–10 mm fraction.However,the Zn content was less than 0.01%.This work provides an in-depth understanding and information on metal recovery as well as promisingly guide ash utilization.展开更多
文摘Silicoaluminophosphate-34(SAPO-34) molecular sieves have important applications in the petrochemical industry as a result of their shape selectivity and suitable acidity. In this work, nanoaggregate SAPO-34 with a large external surface area was obtained by dissolving pseudoboehmite and tetraethylorthosilicate in an aqueous solution of tetraethylammonium hydroxide and subsequently adding phosphoric acid. After hydrolysis in an alkaline solution, the aluminum and silicon precursors exist as Al(OH)4-and SiO2(OH)-, respectively;this is beneficial for rapid nucleation and the formation of nanoaggregates in the following crystallization process. Additionally, to study the effect of the external surface area and pore size on the catalytic performance of different SAPO-34 structures, the alcoholysis of furfuryl alcohol to ethyl levulinate(EL) was chosen as a model reaction. In a comparison with the traditional cube-like SAPO-34, nanoaggregate SAPO-34 generated a higher yield of 74.1% of EL, whereas that with cube-like SAPO-34 was only 19.9%. Moreover, the stability was remarkably enhanced for nanoaggregate SAPO-34. The greater external surface area and larger number of external surface acid sites are helpful in improving the catalytic performance and avoiding coke deposition.
文摘The excessive energy of light,especially the invisible rays with lower wavelength,is basically absorbed by retinal pigment epithelium(RPE)and usually causes DNA damage.The molecular mechanism behind DNA damage repair response to this frequent stress in RPE is not clearly understood.In this study,we determined that the Fanconi anemia(FA)pathway was activated in human RPE ARPE-19 cells after ultraviolet(UV)B and C treatment.Moreover,immunoprecipitation(IP)of FANCD2 indicated that denticleless E3 ubiquitin protein ligase homolog(DTL)closely interacted with FANCD2.Knockdown of DTL weakened the activity of the FA pathway in ARPE-19 cells responding to UV treatment.Finally,the DTL promoter was incubated with a biotin-labeled probe and pulled down by streptavidin beads followed by the genomic DNA sonication.p53 was indicated by mass spectrum and further determined by chromatin IP assay.Taken together,our results demonstrated that DTL regulated by p53 could activate the FA pathway for UV-induced DNA damage repair in retinal pigment epithelial cells.
基金supported by the National Natural Science Foundation of China(No.82173842,82204432)the Medical Science and Technology Research Project of Henan Province,China(No.SBGJ202003010)+1 种基金the Henan Province Science and Technology Research Project(No.222102310414)the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions(China).
文摘There are few tumor cell subpopulations with stem cell characteristics in tumor tis-sue,defined as cancer stem cells(CSCs)or cancer stem-like cells(CSLCs),which can recon-struct neoplasms with malignant biological behaviors such as invasiveness via self-renewal and unlimited generation.The microenvironment that CsCs depend on consists of various cellular components and corresponding medium components.Among these factors existing at a variety of levels and forms,cytokine networks and numerous signal pathways play an important role in signaling transduction.These factors promote or maintain cancer cell stem-ness,and participate in cancer recurrence,metastasis,and resistance.This review aims to summarize the recent molecular data concerning the multilayered relationship between CsCs and CsC-favorable microenvironments.We also discuss the therapeutic implications of target-ing this synergistic interplay,hoping to give an insight into targeting cancer cell stemness for tumortherapyandprognosis.
基金National Natural Science Foundation of China(No.42107237)projects of the key research and development program of Zhejiang Province(No.2021C03164).
文摘Pyrolysis is an effective technology for treating and utilizing biogas residue.To explore the phosphorus(P)supply capacity of the biochar generated from biogas residue of Eichhornia Crassipes,the P speciation of E.crassipes biogas residue and biomass during pyrolysis(300-700°C)was analyzed by combining sequential chemical extraction,31P nuclear magnetic resonance(NMR)and P K-edge X-ray absorption near edge structure(XANES)spectroscopy.Pyrolysis treatment promoted the conversion of amorphous Ca-P phases in biogas residue and biomass into crystalline hydroxyapatite(HAP)phase,which matched the formation of stable HCl-P pools in the biochar derived from biogas residue(AEBs,22.65-82.04%)and biomass(EBs,13.08-33.52%)in the process of pyrolysis.Moreover,the total P contents in AEBs(19.43-28.92 mg g^(−1))were higher than that of EBs(3.41-5.26 mg g^(−1)),indicating that AEBs had a great P reclamation potential.The P release kinetics from AEBs and EBs in water were evaluated via an incubation experiment for 360 h.The P release from both AEBs and EBs conformed to the pseudo-second order kinetics model(R^(2)>0.93),but their P release behaviors were different.The P release of AEBs conformed to the diffusion-re-adsorption model,while that of EBs accorded with the diffusion-dissolution model.The diffusive gradients in thin-films(DGT)analysis showed that AEBs could significantly increase soil available P content as compared with EBs.Hence,the biochar produced from biogas residue of E.crassipes via pyrolysis has a good application potential as a P fertilizer.
基金the projects of the National Natural Science Foundation(No.52170141,No.52236008)the Key Research and Development Program of Zhejiang Province(No.2022C03092)Natural Science Foundation of Zhejiang Province(No.LZ23E060004)。
文摘The bottom ash is increasingly used as a substitute aggregate material in road construction in China,and road salting is the major salt source in groundwater.Continuous rainfall releases soluble salts from the bottom ash subgrade into the surrounding soil and groundwater,resulting in potential hazards.Different methods were employed to simulate and collect runoff water during rainfall events,including batch leaching test,dynamic leaching test and constant head test,to assess environmental impact of bottom ash as road basement materials under continuous rainfall conditions.This study simulated the seepage of bottom ash backfill roads under different rainfall intensities,rainfall times,and rainfall pH values.A comprehensive sampling and laboratory testing program was undertaken to characterize the environmental impact of soluble salts from bottom ash.The obtained results reveal that the leaching concentrations of Cl^(−)and SO_(4)^(2−)exceed the limit specified in the class V standard of surface water,which are 2.06–2.17 times and 1.08–1.25 times,respectively.By examining the long-term environmental influence under the condition of continuous rainfall,the leaching of Cl^(−)mainly occurs in the early leaching stage,and the maximum leaching concentration reaches 19,700 mg/L.The release concentration of Cl^(−)begins to be lower than the class V standard of surface water when continuous rainfall approaches the total rainfall for 13 months.The cumulative release of Cl^(−)in the bottom ash is 2.8–5.4 mg/g.Both rainfall intensity and rain pH affect the release of Cl^(−).The obtained results derived from the constant head tests indicate that stagnant water caused by rainfall deteriorates the release of soluble salt into the groundwater in only 1 day,especially at the early stage of 12 h.This work provides some basic information about how to minimize damage to the surrounding environment caused by the leaching of salt in bottom ash.
文摘Diffusion reaction of the labile building block Mg(acacCN)2 (acacCN= 3-cyanoacetylacetonate) with silver salts leads to a series of solvated Mg/Ag bimetallic coordination polymers with composition [Mg(acacCN)aAg].solvent. Despite their common stoichiometry, the topology of these polymers depends on the solvent of crystallization. The two-dimensional coordination compound [Mg(acacCN)aAg]-4CHCl3 in space group P]- is obtained as platelet-shaped crystals from a mixture of methanol and chloroform. When kept in the reaction mixture, these thin plates within one week convert to isometric tetrahedral crystals of the 3D network [Mg(acacCN)3Ag]. 2CHC13 in the cubic space group/9213. The transformation reaction proceeds via dissolution and recrystallization. The co-crystallized solvent molecules play an important role for stabilizing the target structure: They subtend Cl...Cl contacts and interact via non- classical C-H.-. O hydrogen bonds with the coordination framework. In the new cubic coordination network, both Mg(II) and Ag(I) adopt octahedral coordination, with unprecedented face-sharing by bridging O atoms of three acetylacetonato moieties. Prolonged standing of [Mg(acacCN)3Ag]-2CHCl3 in the reaction medium leads to further degradation, under formation of [Ag(acacCN)].
基金supported by the National Key R&D Program of China No.2018YFA0306503the National Natural Science Foundation of China under Grant Nos.21873016,12174044+1 种基金the International Cooperation Fund Project of DBJI No.ICR2105the Fundamental Research Funds for the Central Universities(DUT21LK08)。
文摘Based on a high level ab initio calculation which is earned out with the multireference configuration interaction method under the aug-cc-pVXZ(AVXZ)basis sets,X=T,Q,5,the accurate potential energy curves(PECs)of the ground state X^(1)Σ_(g)^(+)and the first excited state A^(1)Σ_(u)^(+)of Li_(2)are constructed.By fitting the ab initio potential energy points with the MurrellSorbie potential function,the analytic potential energy functions(APEFs)are obtained.The molecular bond length at the equilibnum(R_(e)),the potential well depth(D_(e)),and the spectroscopic constants(B_(e),ω_(e),α_(e),andω_(e)χ_(e))for the X^(1)Σ_(g)^(+)state and the A^(1)Σ_(u)^(+)state are deduced from the APEFs.The vibrational energy levels of the two electronic states are obtained by solving the time-independent Schrodmger equation with the Founer gnd Hamiltonian method.All the spectroscopic constants and the vibrational levels agree well with the experimental results.The Franck-Condon factors(FCFs)corresponding to the transitions from the vibrational level(v’=0)of the ground state to the vibrational levels(v"=0-74)of the first excited state have been calculated.The FCF for the vibronic transition of A^(1)Σ_(u)^(+)(v"=0)←X^(1)Σ_(g)^(+)(v’=0)is the strongest.These PECs and corresponding spectroscopic constants provide reliable theoretical references to both the spectroscopic and the molecular dynamic studies of the Li_(2)dimer.
基金the project of the National Natural Science Foundation(Grant No.52170141)Key Research and Development Program of Zhejiang Province(Grant No.2021C03164,No.2022C03092),providing financial support for this work.
文摘Metal recovery from bottom ash was deemed to be significant to achieve a higher stability of bottom ash and recycle valuable extractable metals.In China,the existing rugged industrial production ignores the actual metal distribution and thus fails to exploit the utilization potential of recoverable metals in bottom ash.Based on these findings,this work was proposed to obtain a comprehensive and in-depth study on the recoverability of metals in bottom ash.First,the particle size distribution and elemental composition of the bottom ash were analyzed.Then,complete information on the recoverable metals in bottom ash fractions with different sizes was obtained by washing,sorting,crushing,density separation and XRF(X Ray Fluorescence)analysis.The results showed that the smaller than 5 mm fraction accounted for up to 60%of the bottom ash,and the 5–20 mm fractions accounted for about 15%.The material characterization revealed that the contents of recoverable Fe,stainless steel,Al and Cu in bottom ash were averagely 9.01%,0.136%,0.78%and 0.08%,respectively.About 50%of Fe,68%of Al,61%of Cu,and 22%of stainless steel were distributed in smaller than 10 mm fraction.Particularly,Fe was evenly distributed among 0–2 mm,2–5 mm,5–10 mm fractions,and the content was between 5.41%and 7.5%.Non-magnetic stainless steel was mainly distributed in 20–40 mm and larger than 40 mm fractions.The highest share of Al was present in the fractions between 5 mm and 20 mm,accounting for 48%of the total aluminum.About 45.6%of the Cu was enriched in the 5–10 mm fraction.However,the Zn content was less than 0.01%.This work provides an in-depth understanding and information on metal recovery as well as promisingly guide ash utilization.