A phosphite ligand modified heterogeneous catalyst was developed for the hydroformylation of internal olefins to linear aldehydes, which showed a high activity and high regioselectivity and could be separated easily b...A phosphite ligand modified heterogeneous catalyst was developed for the hydroformylation of internal olefins to linear aldehydes, which showed a high activity and high regioselectivity and could be separated easily by filtration after reaction in an autoclave. Three nanoporous silica sieves were used to investigate the influence of pore structure and shape selective performance of support on the regioselectivity to the linear products.展开更多
A novel thermoregulated phosphine ligand PhP(CHCHO)CH(n=22) was synthesized and used for the Rh-catalyzed hydroformylation of mixed Colefins in aqueous/organic biphasic system.Under the optimized conditions,pressure =...A novel thermoregulated phosphine ligand PhP(CHCHO)CH(n=22) was synthesized and used for the Rh-catalyzed hydroformylation of mixed Colefins in aqueous/organic biphasic system.Under the optimized conditions,pressure =5 MPa (H:CO=1:1),phosphine/Rh =13(molar ratio),reaction time =6 h and temperature =130℃,the conversion of Colefins and the yield of aldehyde are 99%and 94%,respectively.The catalyst retained in aqueous phase can be easily separated from the product-containing organic phase by simple phase separation and the catalytic activity remains almost constant after four consecutive cycles.展开更多
We previously showed that hydrogen sulfide(H2S)has a neuroprotective effect in the context of hypoxic ischemic brain injury in neonatal mice.However,the precise mechanism underlying the role of H2S in this situation r...We previously showed that hydrogen sulfide(H2S)has a neuroprotective effect in the context of hypoxic ischemic brain injury in neonatal mice.However,the precise mechanism underlying the role of H2S in this situation remains unclear.In this study,we used a neonatal mouse model of hypoxic ischemic brain injury and a lipopolysaccharide-stimulated BV2 cell model and found that treatment with L-cysteine,a H2S precursor,attenuated the cerebral infarction and cerebral atrophy induced by hypoxia and ischemia and increased the expression of miR-9-5p and cystathionineβsynthase(a major H2S synthetase in the brain)in the prefrontal cortex.We also found that an miR-9-5p inhibitor blocked the expression of cystathionineβsynthase in the prefrontal cortex in mice with brain injury caused by hypoxia and ischemia.Furthermore,miR-9-5p overexpression increased cystathionine-β-synthase and H2S expression in the injured prefrontal cortex of mice with hypoxic ischemic brain injury.L-cysteine decreased the expression of CXCL11,an miR-9-5p target gene,in the prefrontal cortex of the mouse model and in lipopolysaccharide-stimulated BV-2 cells and increased the levels of proinflammatory cytokines BNIP3,FSTL1,SOCS2 and SOCS5,while treatment with an miR-9-5p inhibitor reversed these changes.These findings suggest that H2S can reduce neuroinflammation in a neonatal mouse model of hypoxic ischemic brain injury through regulating the miR-9-5p/CXCL11 axis and restoringβ-synthase expression,thereby playing a role in reducing neuroinflammation in hypoxic ischemic brain injury.展开更多
Citrate, oxalate, tartrate and malate were added into soils during the growthperiod of ryegrass to study the effect of different organic ligands on the release of variousinorganic P (Pi) fractions in a yellow-brown so...Citrate, oxalate, tartrate and malate were added into soils during the growthperiod of ryegrass to study the effect of different organic ligands on the release of variousinorganic P (Pi) fractions in a yellow-brown soil and a paddy soil. The results showed that oxalatewas most effective in promoting the release of total Pi in the yellow-brown soil and tartrate in thepaddy soil. The dominant Pi fractions released from the yellow-brown soil were calcium phosphate(Ca-P) and aluminum phosphate (Al-P) and those from the paddy soil were iron phosphate (Fe-P) andreductant soluble phosphate (O-P) mobilized by tartrate. Phosphorous-mobilizing capability oforganic acids in the yellow-brown soil revealed the following order: oxalate > citrate > malate >tartrate. In the paddy soil, the order was tartrate > citrate ≈ oxalate > malate. It wasdemonstrated that organic ligands were different in their capabilities of mobilizing Pi and the sameorganic ligand showed also a discrepancy in mobilizing P in different soils. Although the additionof organic ligands into soils could increase the amount of P taken up by ryegrass, the more uptakeof P, however, was not only due to the more release of Pi, but also partly from organic P. In manycases, organic ligands promoted the release of the total Pi, while different fractions showeddifferent trends: some increased and others decreased.展开更多
Three chiral aminopyridine ligands derived from L-proline were prepared. Careful evaluation of the corresponding aminopyridine manganese complexes in asymmetric epoxidation of olefins revealed a broad substrate scope ...Three chiral aminopyridine ligands derived from L-proline were prepared. Careful evaluation of the corresponding aminopyridine manganese complexes in asymmetric epoxidation of olefins revealed a broad substrate scope in the presence of 0.2 mol% manganese complex and 0.5 equiv. 2,2-dimethylbutyric acid, with aqueous hydrogen peroxide as an oxidant. A variety of olefins including styrenes, chromenes, and cinnamamides were transformed successfully into the target epoxides with moderate to excellent enantioselectivity（yield up to 95%, ee up to 99%）.展开更多
BACKGROUND Anti-programmed death therapy has thrust immunotherapy into the spotlight.However,such therapy has a modest response in hepatocellular carcinoma(HCC).Epigenetic immunomodulation is a suggestive combinatoria...BACKGROUND Anti-programmed death therapy has thrust immunotherapy into the spotlight.However,such therapy has a modest response in hepatocellular carcinoma(HCC).Epigenetic immunomodulation is a suggestive combinatorial therapy with immune checkpoint blockade.Non-coding ribonucleic acid(ncRNA)driven regulation is a major mechanism of epigenetic modulation.Given the wide range of ncRNAs that co-opt in programmed cell-death protein 1(PD-1)/programmed death ligand 1(PD-L1)regulation,and based on the literature,we hypothesized that miR-155-5p,miR-194-5p and long non-coding RNAs(lncRNAs)X-inactive specific transcript(XIST)and MALAT-1 are involved in a regulatory upstream pathway for PD-1/PD-L1.Recently,nutraceutical therapeutics in cancers have received increasing attention.Thus,it is interesting to study the impact of oleuropein on the respective study key players.AIM To explore potential upstream regulatory ncRNAs for the immune checkpoint PD-1/PD-L1.METHODS Bioinformatics tools including microrna.org and lnCeDB software were adopted to detect targeting of miR-155-5p,miR-194-5p and lncRNAs XIST and MALAT-1 to PD-L1 mRNA,respectively.In addition,Diana tool was used to predict targeting of both aforementioned miRNAs to lncRNAs XIST and MALAT-1.HCC and normal tissue samples were collected for scanning of PD-L1,XIST and MALAT-1 expression.To study the interaction among miR-155-5p,miR-194-5p,lncRNAs XIST and MALAT-1,as well as PD-L1 mRNA,a series of transfections of the Huh-7 cell line was carried out.RESULTS Bioinformatics software predicted that miR-155-5p and miR-194-5p can target PDL1,MALAT-1 and XIST.MALAT-1 and XIST were predicted to target PD-L1 mRNA.PD-L1 and XIST were significantly upregulated in 23 HCC biopsies compared to healthy controls;however,MALAT-1 was barely detected.MiR-194 induced expression elevated the expression of PD-L1,XIST and MALAT-1.However,overexpression of miR-155-5p induced the upregulation of PD-L1 and XIST,while it had a negative impact on MALAT-1 expression.Knockdown of XIST did have an impact on PD-L1 expression;however,following knockdown of the negative regulator of X-inactive specific transcript(TSIX),PD-L1 expression was elevated,and abolished MALAT-1 activity.Upon co-transfection of miR-194-5p with siMALAT-1,PD-L1 expression was elevated.Co-transfection of miR-194-5p with siXIST did not have an impact on PD-L1 expression.Upon co-transfection of miR-194 with siTSIX,PD-L1 expression was upregulated.Interestingly,the same PD-L1 expression pattern was observed following miR-155-5p cotransfections.Oleuropein treatment of Huh-7 cells reduced the expression profile of PD-L1,XIST,and miR-155-5p,upregulated the expression of miR-194-5p and had no significant impact on the MALAT-1 expression profile.CONCLUSION This study reported a novel finding revealing that opposing acting miRNAs in HCC,have the same impact on PD-1/PD-L1 immune checkpoint by sharing a common signaling pathway.展开更多
A novel chiral bis(ferrocenyl) P2N ligand 1 with C2-symmetry was synthesized through a four-step procedure from (R)-N,N-dimethyl-1-ferrocenylethylamine. In a model reaction of Pd-catalyzed allylic alkylation of 1,3-d...A novel chiral bis(ferrocenyl) P2N ligand 1 with C2-symmetry was synthesized through a four-step procedure from (R)-N,N-dimethyl-1-ferrocenylethylamine. In a model reaction of Pd-catalyzed allylic alkylation of 1,3-diphenylprop-2-enyl acetate 6 with dimethyl malonate, good enantioselectivity (86% e.e.) was obtained.展开更多
基金Supported by the Ministry of Science and Technology of China(No.2009CB623503)
文摘A phosphite ligand modified heterogeneous catalyst was developed for the hydroformylation of internal olefins to linear aldehydes, which showed a high activity and high regioselectivity and could be separated easily by filtration after reaction in an autoclave. Three nanoporous silica sieves were used to investigate the influence of pore structure and shape selective performance of support on the regioselectivity to the linear products.
基金the financial support from the Program for New Century Excellent Talents in University (No.NCET-07-0138)the Science and Technology Project in Universities from the Education Department of Liaoning Province(No.2008T233).
文摘A novel thermoregulated phosphine ligand PhP(CHCHO)CH(n=22) was synthesized and used for the Rh-catalyzed hydroformylation of mixed Colefins in aqueous/organic biphasic system.Under the optimized conditions,pressure =5 MPa (H:CO=1:1),phosphine/Rh =13(molar ratio),reaction time =6 h and temperature =130℃,the conversion of Colefins and the yield of aldehyde are 99%and 94%,respectively.The catalyst retained in aqueous phase can be easily separated from the product-containing organic phase by simple phase separation and the catalytic activity remains almost constant after four consecutive cycles.
基金supported by the National Natural Science Foundation of China,Nos.82271327(to ZW),82072535(to ZW),81873768(to ZW),and 82001253(to TL).
文摘We previously showed that hydrogen sulfide(H2S)has a neuroprotective effect in the context of hypoxic ischemic brain injury in neonatal mice.However,the precise mechanism underlying the role of H2S in this situation remains unclear.In this study,we used a neonatal mouse model of hypoxic ischemic brain injury and a lipopolysaccharide-stimulated BV2 cell model and found that treatment with L-cysteine,a H2S precursor,attenuated the cerebral infarction and cerebral atrophy induced by hypoxia and ischemia and increased the expression of miR-9-5p and cystathionineβsynthase(a major H2S synthetase in the brain)in the prefrontal cortex.We also found that an miR-9-5p inhibitor blocked the expression of cystathionineβsynthase in the prefrontal cortex in mice with brain injury caused by hypoxia and ischemia.Furthermore,miR-9-5p overexpression increased cystathionine-β-synthase and H2S expression in the injured prefrontal cortex of mice with hypoxic ischemic brain injury.L-cysteine decreased the expression of CXCL11,an miR-9-5p target gene,in the prefrontal cortex of the mouse model and in lipopolysaccharide-stimulated BV-2 cells and increased the levels of proinflammatory cytokines BNIP3,FSTL1,SOCS2 and SOCS5,while treatment with an miR-9-5p inhibitor reversed these changes.These findings suggest that H2S can reduce neuroinflammation in a neonatal mouse model of hypoxic ischemic brain injury through regulating the miR-9-5p/CXCL11 axis and restoringβ-synthase expression,thereby playing a role in reducing neuroinflammation in hypoxic ischemic brain injury.
基金Project supported by the National Key Basic Research Support Foundation (NKBRSF) of China (No.G1999011806).
文摘Citrate, oxalate, tartrate and malate were added into soils during the growthperiod of ryegrass to study the effect of different organic ligands on the release of variousinorganic P (Pi) fractions in a yellow-brown soil and a paddy soil. The results showed that oxalatewas most effective in promoting the release of total Pi in the yellow-brown soil and tartrate in thepaddy soil. The dominant Pi fractions released from the yellow-brown soil were calcium phosphate(Ca-P) and aluminum phosphate (Al-P) and those from the paddy soil were iron phosphate (Fe-P) andreductant soluble phosphate (O-P) mobilized by tartrate. Phosphorous-mobilizing capability oforganic acids in the yellow-brown soil revealed the following order: oxalate > citrate > malate >tartrate. In the paddy soil, the order was tartrate > citrate ≈ oxalate > malate. It wasdemonstrated that organic ligands were different in their capabilities of mobilizing Pi and the sameorganic ligand showed also a discrepancy in mobilizing P in different soils. Although the additionof organic ligands into soils could increase the amount of P taken up by ryegrass, the more uptakeof P, however, was not only due to the more release of Pi, but also partly from organic P. In manycases, organic ligands promoted the release of the total Pi, while different fractions showeddifferent trends: some increased and others decreased.
基金supported by the National Natural Science Foundation of China(21473226,21773273)Key Research Program of Frontier Sciences,CAS(QYZDJ-SSW-SLH051)Natural Science Foundation of Jiangsu Province(BK20170420)~~
文摘Three chiral aminopyridine ligands derived from L-proline were prepared. Careful evaluation of the corresponding aminopyridine manganese complexes in asymmetric epoxidation of olefins revealed a broad substrate scope in the presence of 0.2 mol% manganese complex and 0.5 equiv. 2,2-dimethylbutyric acid, with aqueous hydrogen peroxide as an oxidant. A variety of olefins including styrenes, chromenes, and cinnamamides were transformed successfully into the target epoxides with moderate to excellent enantioselectivity（yield up to 95%, ee up to 99%）.
文摘BACKGROUND Anti-programmed death therapy has thrust immunotherapy into the spotlight.However,such therapy has a modest response in hepatocellular carcinoma(HCC).Epigenetic immunomodulation is a suggestive combinatorial therapy with immune checkpoint blockade.Non-coding ribonucleic acid(ncRNA)driven regulation is a major mechanism of epigenetic modulation.Given the wide range of ncRNAs that co-opt in programmed cell-death protein 1(PD-1)/programmed death ligand 1(PD-L1)regulation,and based on the literature,we hypothesized that miR-155-5p,miR-194-5p and long non-coding RNAs(lncRNAs)X-inactive specific transcript(XIST)and MALAT-1 are involved in a regulatory upstream pathway for PD-1/PD-L1.Recently,nutraceutical therapeutics in cancers have received increasing attention.Thus,it is interesting to study the impact of oleuropein on the respective study key players.AIM To explore potential upstream regulatory ncRNAs for the immune checkpoint PD-1/PD-L1.METHODS Bioinformatics tools including microrna.org and lnCeDB software were adopted to detect targeting of miR-155-5p,miR-194-5p and lncRNAs XIST and MALAT-1 to PD-L1 mRNA,respectively.In addition,Diana tool was used to predict targeting of both aforementioned miRNAs to lncRNAs XIST and MALAT-1.HCC and normal tissue samples were collected for scanning of PD-L1,XIST and MALAT-1 expression.To study the interaction among miR-155-5p,miR-194-5p,lncRNAs XIST and MALAT-1,as well as PD-L1 mRNA,a series of transfections of the Huh-7 cell line was carried out.RESULTS Bioinformatics software predicted that miR-155-5p and miR-194-5p can target PDL1,MALAT-1 and XIST.MALAT-1 and XIST were predicted to target PD-L1 mRNA.PD-L1 and XIST were significantly upregulated in 23 HCC biopsies compared to healthy controls;however,MALAT-1 was barely detected.MiR-194 induced expression elevated the expression of PD-L1,XIST and MALAT-1.However,overexpression of miR-155-5p induced the upregulation of PD-L1 and XIST,while it had a negative impact on MALAT-1 expression.Knockdown of XIST did have an impact on PD-L1 expression;however,following knockdown of the negative regulator of X-inactive specific transcript(TSIX),PD-L1 expression was elevated,and abolished MALAT-1 activity.Upon co-transfection of miR-194-5p with siMALAT-1,PD-L1 expression was elevated.Co-transfection of miR-194-5p with siXIST did not have an impact on PD-L1 expression.Upon co-transfection of miR-194 with siTSIX,PD-L1 expression was upregulated.Interestingly,the same PD-L1 expression pattern was observed following miR-155-5p cotransfections.Oleuropein treatment of Huh-7 cells reduced the expression profile of PD-L1,XIST,and miR-155-5p,upregulated the expression of miR-194-5p and had no significant impact on the MALAT-1 expression profile.CONCLUSION This study reported a novel finding revealing that opposing acting miRNAs in HCC,have the same impact on PD-1/PD-L1 immune checkpoint by sharing a common signaling pathway.
基金supported by the National Natural Science Foundation of China(29933050)
文摘A novel chiral bis(ferrocenyl) P2N ligand 1 with C2-symmetry was synthesized through a four-step procedure from (R)-N,N-dimethyl-1-ferrocenylethylamine. In a model reaction of Pd-catalyzed allylic alkylation of 1,3-diphenylprop-2-enyl acetate 6 with dimethyl malonate, good enantioselectivity (86% e.e.) was obtained.
