The temperature of waste gas in refuse transfer station,airport smoking area,and RTO terminal is low,which needs deep oxidation.Catalytic ozonation is one of the most effective treatment techniques in these scenarios....The temperature of waste gas in refuse transfer station,airport smoking area,and RTO terminal is low,which needs deep oxidation.Catalytic ozonation is one of the most effective treatment techniques in these scenarios.In this study,we reported that catalysts were modified under the condition of mag-netic field to simulate the low temperature dynamic conditions of low concentration toluene for catalytic ozonation.This paper aims to explore the relationship between oxygen vacancy and active oxygen species,and the specific pathways of toluene oxidation.The study found that citric acid can enhance the syner-gistic effect between Mn and Ce,and promote the generation of oxygen vacancies.The surface molecule adsorption oxygen is more conducive to catalytic oxidation than subsurface atom adsorption oxygen.Fi-nally,we proposed the main pathways of toluene in this reaction system,which runs through the whole process of the reaction.展开更多
Preservation of growth factor sensitivity and bioactivity(e.g.,bone morphogenetic protein-2(BMP-2))post-immobilization to tissue engineering scaffolds remains a great challenge.Here,we develop a stable and soft surfac...Preservation of growth factor sensitivity and bioactivity(e.g.,bone morphogenetic protein-2(BMP-2))post-immobilization to tissue engineering scaffolds remains a great challenge.Here,we develop a stable and soft surface modification strategy to address this issue.BMP-2(a model growth factor)is covalently immobilized onto homogeneous poly(glycidyl methacrylate)(PGMA)polymer brushes which are grafted onto substrate surfaces(Au,quartz glass,silica wafer,or common biomaterials)via surface-initiated atom transfer radical polymerization.This surface modification method multiplies the functionalized interfacial area;it is simple,fast,gentle,and has little effect on the loaded protein owing to the cilia motility.The immobilized BMP-2(i-BMP-2)on the surface of homogeneous PGMA polymer brushes exhibits excellent bioactivity(-87%bioactivity of free BMP-2 in vitro and 20%-50%higher than scaffolds with free BMP-2 in vivo),with conformation and secondary structure well-preserved after covalent immobilization and ethanol sterilization.Moreover,the osteogenic activity of i-BMP-2 on the nanoline pattern(PGMA-poly(N-isopropylacrylamide))shows-110%bioactivity of free BMP-2.This is superior compared to conventional protein covalent immobilization strategies in terms of both bioactivity preservation and therapeutic efficacy.PGMA polymer brushes can be used to modify surfaces of different tissue-engineered scaffolds,which facilitates in situ immobilization of growth factors,and accelerates repair of a wide range of tissue types.展开更多
Kinase,putative Endopeptidase,and Other Proteins of Small size(KEOPS)is a multisubunit protein complex conserved in eukaryotes and archaea.It is composed of Pcc1,Kae1,Bud32,Cgi121,and Gon7 in eukaryotes and is primari...Kinase,putative Endopeptidase,and Other Proteins of Small size(KEOPS)is a multisubunit protein complex conserved in eukaryotes and archaea.It is composed of Pcc1,Kae1,Bud32,Cgi121,and Gon7 in eukaryotes and is primarily involved in N^(6)-threonylcarbamoyl adenosine(t^(6)A)modification of transfer RNAs(tRNAs).Recently,it was reported that KEOPS participates in homologous recombination(HR)repair in yeast.To characterize the KEOPS in archaea(aKEOPS),we conducted genetic and biochemical analyses of its encoding genes in the hyperthermophilic archaeon Saccharolobus islandicus.We show that aKEOPS also possesses five subunits,Pcc1,Kae1,Bud32,Cgi121,and Pcc1-like(or Gon7-like),just like eukaryotic KEOPS.Pcc1-like has physical interactions with Kae1 and Pcc1 and can mediate the monomerization of the dimeric subcomplex(Kae1-Pcc1-Pcc1-Kae1),suggesting that Pcc1-like is a functional homolog of the eukaryotic Gon7 subunit.Strikingly,none of the genes encoding aKEOPS subunits,including Pcc1 and Pcc1-like,can be deleted in the wild type and in a t^(6)A modification complementary strain named TsaKI,implying that the aKEOPS complex is essential for an additional cellular process in this archaeon.Knock-down of the Cgi121 subunit leads to severe growth retardance in the wild type that is partially rescued in TsaKI.These results suggest that aKEOPS plays an essential role independent of the cellular t^(6)A modification level.In addition,archaeal Cgi121 possesses dsDNA-binding activity that relies on its tRNA 3ʹCCA tail binding module.Our study clarifies the subunit organization of archaeal KEOPS and suggests an origin of eukaryotic Gon7.The study also reveals a possible link between the function in t^(6)A modification and the additional function,presumably HR.展开更多
Background: The aim of this study was to assess the performance of apparent diffusion coefficient (ADC) measurement obtained with diffusion-weighted magnetic resonance imaging (DW-MRI) to distinguish renal cell c...Background: The aim of this study was to assess the performance of apparent diffusion coefficient (ADC) measurement obtained with diffusion-weighted magnetic resonance imaging (DW-MRI) to distinguish renal cell carcinomas (RCCs) from small benign solid renal tumors (〈4 cm). Methods: In this cross-sectional study, 49 consecutive patients with histopathologically confirmed small solid renal tumors, and seven healthy volunteers were imaged using nonenhanced MRI and DW-MRI. The ADC map was calculated using the b values of 0, 50, 400, and 600 s/ mm2 and values compared via the Kruskal-Wallis and Mann-Whitney tests. The utility of ADC for differentiating RCCs and benign lesions was assessed using a receiver operating characteristic curve. Multiple nonenhanced MRI features were analyzed by Logistic regression. Results: The tumors consisted of 33 cases of clear-cell RCCs (ccRCCs) and 16 cases of benign tumors, including 14 cases of minimal fat angiomyolipomas and 2 cases ofoncocytomas. The ADCs showed significant differences among benign tumors ([0.90 ±0.52] x 10 x mm2/s), ccRCCs ([1.53 ± 0.31 ] x 10 ^3 mm2/s) and the normal renal parenchyma ([2.22 ± 0.12]x 10^-3 mmVs) (P 〈 0.001). Moreover, there was statistically significant difference between high and low-grade ccRCCs (P = 0.004). Using a cut-offADC of 1.36± 10 3 mm2/s, DW-MRI resulted in an area under the curve (AUC), sensitivity, and specificity equal to 0.839, 75.8%, and 87.5%, respectively. Nonenhanced MRI alone and the combination of imaging methods led to an AUC, sensitivity and specificity equal to 0.919, 93.9%, and 81.2%, 0.998, 97%, and 100%, respectively. The Logistic regression showed that the location of the center of the tumor (inside the contour of the kidney) and appearance of stiffblood vessel were significantly helpful for diagnosing ccRCCs. Conclusions: DW-MRI has potential in distinguishing ccRCCs from benign lesions in human small solid renal tumors (〈4 cm), and in increasing the accuracy for diagnosing ccRCCs when combined with nonenhanced MRI.展开更多
Improving the osteogenic activity of BMP-2 in vivo has significant clinical application value.In this research,we use a clinical gelatin sponge scaffold loaded with BMP-2 and dexamethasone(Dex)to evaluate the osteogen...Improving the osteogenic activity of BMP-2 in vivo has significant clinical application value.In this research,we use a clinical gelatin sponge scaffold loaded with BMP-2 and dexamethasone(Dex)to evaluate the osteogenic activity of dual drugs via ectopic osteogenesis in vivo.We also investigate the mechanism of osteogenesis induced by BMP-2 and Dex with C2C12,a multipotent muscle-derived progenitor cell.The results show that the gelatin scaffold with Dex and BMP-2 can significantly accelerate osteogenesis in vivo.It is indicated that compared with the BMP-2 or Dex alone,100nM of Dex can dramatically enhance the BMP-2-induced alkaline phosphatase activity(ALP),ALP mRNA expression and mineralization.Further studies show that 100nM of Dex can maintain the secondary structure of BMP-2 and facilitate recognition of BMP-2 with its receptors on the surface of C2C12 cells.We also find that in C2C12,Dex has no obvious effect on the BMP-2-induced Smad1/5/8 protein expression and the STAT3-dependent pathway,but Runx2-dependent pathway is involved in the Dex-stimulated osteoblast differentiation of BMP-2 both in vitro and in vivo.Based on these results,a potential mechanism model about the synergistic osteoinductive effect of Dex and BMP-2 in C2C12 cells via Runx2 activation is proposed.This may provide a theoretical basis for the pre-clinical application of Dex and BMP-2 for bone regeneration.展开更多
高温会加快碱基脱氨基反应形成损伤碱基的速率,进一步对脱氨基的碱基进行复制会导致突变。因此,极端嗜热古菌基因组的稳定性面临着其生存高温环境的挑战。胞嘧啶脱氨基形成尿嘧啶,是常见的脱碱基类型,复制DNA中尿嘧啶会造成GC→AT的突...高温会加快碱基脱氨基反应形成损伤碱基的速率,进一步对脱氨基的碱基进行复制会导致突变。因此,极端嗜热古菌基因组的稳定性面临着其生存高温环境的挑战。胞嘧啶脱氨基形成尿嘧啶,是常见的脱碱基类型,复制DNA中尿嘧啶会造成GC→AT的突变。尿嘧啶DNA糖苷酶(Uracil DNA glycosylase,UDG)是修复DNA中尿嘧啶的关键酶。基于识别底物的特异性,UDG分为6个家族,广泛分布在细菌、古菌、真核生物以及一些病毒中。基因组序列显示,极端嗜热古菌至少编码一种UDG。目前,对于细菌和真核生物的UDG已进行了大量的研究,但是关于极端嗜热古菌UDG的研究相对较少,尚处于初期阶段。本文综述了极端嗜热古菌UDG的研究进展,并对今后的研究提出了展望。展开更多
基金financially supported by the Scientific Research Project of Guangzhou City(No.201804020026)the National Nat-ural Science Foundation of China(Nos.51878293,21777047)+1 种基金the National Key Research and Development Program of China(No.2018YFB0605200)the Natural Science Foundation of Guang-dong Province(No.2017B090901049).
文摘The temperature of waste gas in refuse transfer station,airport smoking area,and RTO terminal is low,which needs deep oxidation.Catalytic ozonation is one of the most effective treatment techniques in these scenarios.In this study,we reported that catalysts were modified under the condition of mag-netic field to simulate the low temperature dynamic conditions of low concentration toluene for catalytic ozonation.This paper aims to explore the relationship between oxygen vacancy and active oxygen species,and the specific pathways of toluene oxidation.The study found that citric acid can enhance the syner-gistic effect between Mn and Ce,and promote the generation of oxygen vacancies.The surface molecule adsorption oxygen is more conducive to catalytic oxidation than subsurface atom adsorption oxygen.Fi-nally,we proposed the main pathways of toluene in this reaction system,which runs through the whole process of the reaction.
基金financial support from RGC Senior Research Fellow Scheme(SRFS2122-5S04),Research Grants Council of Hong KongCollaborative Research Fund(C5044-21GF)from the Research Grants Council of Hong Kong and National Excellent Young Scientists Fund(Hong Kong and Macao,82122002),National Natural Science Foundation of China+1 种基金support from National Natural Science Foundation of China(No.32071337)Shanghai Pujiang Program(20PJ1402600).
文摘Preservation of growth factor sensitivity and bioactivity(e.g.,bone morphogenetic protein-2(BMP-2))post-immobilization to tissue engineering scaffolds remains a great challenge.Here,we develop a stable and soft surface modification strategy to address this issue.BMP-2(a model growth factor)is covalently immobilized onto homogeneous poly(glycidyl methacrylate)(PGMA)polymer brushes which are grafted onto substrate surfaces(Au,quartz glass,silica wafer,or common biomaterials)via surface-initiated atom transfer radical polymerization.This surface modification method multiplies the functionalized interfacial area;it is simple,fast,gentle,and has little effect on the loaded protein owing to the cilia motility.The immobilized BMP-2(i-BMP-2)on the surface of homogeneous PGMA polymer brushes exhibits excellent bioactivity(-87%bioactivity of free BMP-2 in vitro and 20%-50%higher than scaffolds with free BMP-2 in vivo),with conformation and secondary structure well-preserved after covalent immobilization and ethanol sterilization.Moreover,the osteogenic activity of i-BMP-2 on the nanoline pattern(PGMA-poly(N-isopropylacrylamide))shows-110%bioactivity of free BMP-2.This is superior compared to conventional protein covalent immobilization strategies in terms of both bioactivity preservation and therapeutic efficacy.PGMA polymer brushes can be used to modify surfaces of different tissue-engineered scaffolds,which facilitates in situ immobilization of growth factors,and accelerates repair of a wide range of tissue types.
基金supported by the National Key Research and Development Program of China(No.2020YFA0906800)the National Natural Science Foundation of China(Nos.31970546 and 31670061 to Y.S.,31900055 to Q.H.,31970119 to J.N.,and 31771380 to Q.S.)the State Key Laboratory of Microbial Technology.
文摘Kinase,putative Endopeptidase,and Other Proteins of Small size(KEOPS)is a multisubunit protein complex conserved in eukaryotes and archaea.It is composed of Pcc1,Kae1,Bud32,Cgi121,and Gon7 in eukaryotes and is primarily involved in N^(6)-threonylcarbamoyl adenosine(t^(6)A)modification of transfer RNAs(tRNAs).Recently,it was reported that KEOPS participates in homologous recombination(HR)repair in yeast.To characterize the KEOPS in archaea(aKEOPS),we conducted genetic and biochemical analyses of its encoding genes in the hyperthermophilic archaeon Saccharolobus islandicus.We show that aKEOPS also possesses five subunits,Pcc1,Kae1,Bud32,Cgi121,and Pcc1-like(or Gon7-like),just like eukaryotic KEOPS.Pcc1-like has physical interactions with Kae1 and Pcc1 and can mediate the monomerization of the dimeric subcomplex(Kae1-Pcc1-Pcc1-Kae1),suggesting that Pcc1-like is a functional homolog of the eukaryotic Gon7 subunit.Strikingly,none of the genes encoding aKEOPS subunits,including Pcc1 and Pcc1-like,can be deleted in the wild type and in a t^(6)A modification complementary strain named TsaKI,implying that the aKEOPS complex is essential for an additional cellular process in this archaeon.Knock-down of the Cgi121 subunit leads to severe growth retardance in the wild type that is partially rescued in TsaKI.These results suggest that aKEOPS plays an essential role independent of the cellular t^(6)A modification level.In addition,archaeal Cgi121 possesses dsDNA-binding activity that relies on its tRNA 3ʹCCA tail binding module.Our study clarifies the subunit organization of archaeal KEOPS and suggests an origin of eukaryotic Gon7.The study also reveals a possible link between the function in t^(6)A modification and the additional function,presumably HR.
文摘Background: The aim of this study was to assess the performance of apparent diffusion coefficient (ADC) measurement obtained with diffusion-weighted magnetic resonance imaging (DW-MRI) to distinguish renal cell carcinomas (RCCs) from small benign solid renal tumors (〈4 cm). Methods: In this cross-sectional study, 49 consecutive patients with histopathologically confirmed small solid renal tumors, and seven healthy volunteers were imaged using nonenhanced MRI and DW-MRI. The ADC map was calculated using the b values of 0, 50, 400, and 600 s/ mm2 and values compared via the Kruskal-Wallis and Mann-Whitney tests. The utility of ADC for differentiating RCCs and benign lesions was assessed using a receiver operating characteristic curve. Multiple nonenhanced MRI features were analyzed by Logistic regression. Results: The tumors consisted of 33 cases of clear-cell RCCs (ccRCCs) and 16 cases of benign tumors, including 14 cases of minimal fat angiomyolipomas and 2 cases ofoncocytomas. The ADCs showed significant differences among benign tumors ([0.90 ±0.52] x 10 x mm2/s), ccRCCs ([1.53 ± 0.31 ] x 10 ^3 mm2/s) and the normal renal parenchyma ([2.22 ± 0.12]x 10^-3 mmVs) (P 〈 0.001). Moreover, there was statistically significant difference between high and low-grade ccRCCs (P = 0.004). Using a cut-offADC of 1.36± 10 3 mm2/s, DW-MRI resulted in an area under the curve (AUC), sensitivity, and specificity equal to 0.839, 75.8%, and 87.5%, respectively. Nonenhanced MRI alone and the combination of imaging methods led to an AUC, sensitivity and specificity equal to 0.919, 93.9%, and 81.2%, 0.998, 97%, and 100%, respectively. The Logistic regression showed that the location of the center of the tumor (inside the contour of the kidney) and appearance of stiffblood vessel were significantly helpful for diagnosing ccRCCs. Conclusions: DW-MRI has potential in distinguishing ccRCCs from benign lesions in human small solid renal tumors (〈4 cm), and in increasing the accuracy for diagnosing ccRCCs when combined with nonenhanced MRI.
基金supported by the Natural Science Foundation of China for Innovative Research Groups(No.51621002)the National Natural Science Foundation of China(No.32071337)+2 种基金Shanghai Pujiang Program(20PJ1402600)the 111 Project(B14018)supported by‘the Fundamental Research Funds for the Central Universities’.
文摘Improving the osteogenic activity of BMP-2 in vivo has significant clinical application value.In this research,we use a clinical gelatin sponge scaffold loaded with BMP-2 and dexamethasone(Dex)to evaluate the osteogenic activity of dual drugs via ectopic osteogenesis in vivo.We also investigate the mechanism of osteogenesis induced by BMP-2 and Dex with C2C12,a multipotent muscle-derived progenitor cell.The results show that the gelatin scaffold with Dex and BMP-2 can significantly accelerate osteogenesis in vivo.It is indicated that compared with the BMP-2 or Dex alone,100nM of Dex can dramatically enhance the BMP-2-induced alkaline phosphatase activity(ALP),ALP mRNA expression and mineralization.Further studies show that 100nM of Dex can maintain the secondary structure of BMP-2 and facilitate recognition of BMP-2 with its receptors on the surface of C2C12 cells.We also find that in C2C12,Dex has no obvious effect on the BMP-2-induced Smad1/5/8 protein expression and the STAT3-dependent pathway,but Runx2-dependent pathway is involved in the Dex-stimulated osteoblast differentiation of BMP-2 both in vitro and in vivo.Based on these results,a potential mechanism model about the synergistic osteoinductive effect of Dex and BMP-2 in C2C12 cells via Runx2 activation is proposed.This may provide a theoretical basis for the pre-clinical application of Dex and BMP-2 for bone regeneration.
文摘高温会加快碱基脱氨基反应形成损伤碱基的速率,进一步对脱氨基的碱基进行复制会导致突变。因此,极端嗜热古菌基因组的稳定性面临着其生存高温环境的挑战。胞嘧啶脱氨基形成尿嘧啶,是常见的脱碱基类型,复制DNA中尿嘧啶会造成GC→AT的突变。尿嘧啶DNA糖苷酶(Uracil DNA glycosylase,UDG)是修复DNA中尿嘧啶的关键酶。基于识别底物的特异性,UDG分为6个家族,广泛分布在细菌、古菌、真核生物以及一些病毒中。基因组序列显示,极端嗜热古菌至少编码一种UDG。目前,对于细菌和真核生物的UDG已进行了大量的研究,但是关于极端嗜热古菌UDG的研究相对较少,尚处于初期阶段。本文综述了极端嗜热古菌UDG的研究进展,并对今后的研究提出了展望。