The CIDNP observations indicated that photoreaction of methylfurans with chloranil resulted not only furylmethyl hydroxyphenyl ethers via radical pairs but induced furyl radical isomerization to the derivatives of cyc...The CIDNP observations indicated that photoreaction of methylfurans with chloranil resulted not only furylmethyl hydroxyphenyl ethers via radical pairs but induced furyl radical isomerization to the derivatives of cyclopropene,propadiene and pyran.展开更多
Photochemical reactions of 3-methylindole,carbazole,benzimidazole with fused polycyclic aromatic hydrocarbons in solid state were investigated,The structures of 4 new compounds were confirmed by IR,UV,\+1HNNR,MS and e...Photochemical reactions of 3-methylindole,carbazole,benzimidazole with fused polycyclic aromatic hydrocarbons in solid state were investigated,The structures of 4 new compounds were confirmed by IR,UV,\+1HNNR,MS and elemental analysis.The structure of compounds 3.6 was established by X-ray crystallography.展开更多
In this article, polyphosphate-accumulating organisms （PAOs） from a lab-scale continuous-flow two-sludge system was isolated and identified, the different phosphorus accumulation characteristics of the isolates unde...In this article, polyphosphate-accumulating organisms （PAOs） from a lab-scale continuous-flow two-sludge system was isolated and identified, the different phosphorus accumulation characteristics of the isolates under anoxic and aerobic conditions were investigated. Two kinds of PAOs were both found in the anoxic zones of the two-sludge system, one of them utilized only oxygen as electron aeceptor, and the other one utilized either nitrate or oxygen as electron aeceptor. Of the total eight isolates, five isolates were capable of utilizing both nitrate and oxygen as electron acceptors to uptake phosphorus to some extent. And three of the five isolates showed good phosphorus accumulative capacities both under anoxic or aerobic conditions, two identified as Alcaligenes and one identified as Pseudomonas. Streptococcus was observed weak anoxic phosphorus accumulation because of its weak denitrification capacity, but it showed good phosphorus accumulation capacity under aerobic conditions. One isolates identified as Enterobacteriaceae was proved to be a special species of PAOs, which could only uptake small amounts of phosphorus under anoxic conditions, although its denitrification capacity and aerobic phosphorus accumulation capacity were excellent.展开更多
The association between continuous-flow left ventricular assist devices(CF-LVADs)and gastrointestinal(GI)bleeding from angiodysplasia is well recognized.However,the association between continuous-flow biventricular as...The association between continuous-flow left ventricular assist devices(CF-LVADs)and gastrointestinal(GI)bleeding from angiodysplasia is well recognized.However,the association between continuous-flow biventricular assist devices(CF-BIVADs)and bleeding angiodysplasia is less understood.We report a case of GI bleeding from a patient with a CF-BIVAD.The location of GI bleeding was identified by nuclear red blood cell bleeding scan.The vascular malformation leading to the bleed was identified and localized on angiography and then by pathology.The intensity of bleeding,reflected by number of units of packed red blood cells needed for normalization of hemoglobin,as well as the time to onset of bleeding after transplantation,are similar to that seen in the literature for CF-LVADs and pulsatile BIVADs.While angiography only detected a dilated late draining vein,pathology demonstrated the presence of both arterial and venous dilation in the submucosa,vascular abnormalities characteristic of a late arteriovenous malformation.展开更多
Photodynamic therapy(PDT)usually shows limited efficacy in solid tumors since traditional PDT is O_(2)^(-)dependent while solid tumors are inherently hypoxic.In addition,hypoxic tumor cells possess antiapoptotic pathw...Photodynamic therapy(PDT)usually shows limited efficacy in solid tumors since traditional PDT is O_(2)^(-)dependent while solid tumors are inherently hypoxic.In addition,hypoxic tumor cells possess antiapoptotic pathways that resist PDT-induced apoptosis.Therefore,developing photosensitizers(PSs)that show low O_(2)^(-)dependency and can induce nonapoptotic cell death pathways is critically needed.Herein,a series of Ru(II)polypyridine complex-based PSs,RuNMe,RuH,and RuCN,were synthesized,and their applications against hypoxic tumor cells through PDT were investigated.All three complexes showthe ability to generate the superoxide anion radical(·O_(2)^(-)),which is the type I photoreaction and less O_(2)^(-)dependent.RuNMe shows the best PDT performance against MCF-7 cells and three-dimensional multicellular spheroids,due to its higher cellular uptake and more reactive oxygen species generation.More importantly,RuNMe-incubated MCF-7 cells show photoinduced ferroptosis as evidenced by glutathione peroxidase 4 downregulation and lipid peroxide accumulation.This work not only develops a novel ferroptosis-inducing Ru(II)complex with the type I PDT process but also offers an effective strategy to solve tumor hypoxia in PDT.展开更多
A new continuous-flow process for the enzymatic synthesis of optically pureγ-lactones,which are used as flavors and fragrances in the food and cosmetic industries,was developed in a three-dimensional microfluidic rea...A new continuous-flow process for the enzymatic synthesis of optically pureγ-lactones,which are used as flavors and fragrances in the food and cosmetic industries,was developed in a three-dimensional microfluidic reactor.The microchannels(175 mm in length,0.9 mm in depth,and 1.72 mL in volume)were carved precisely inside a single borosilicate glass(90 mm×75 mm×12 mm)with ultrafast femtosecond laser micromachining.The flow field analysis and reaction simulation showed that the mixing of substrates and enzymes was enhanced,allowing the adjustment of residence time in a wide window.SmCR_(V4),a carbonyl reductase with excellent catalytic activity and enantioselectivity towardγ/δ-keto acids,was employed for the asymmetric synthesis of various chiral lactones.30 mmol/L(R)-γ-decalactone(3g)can be obtained in 26 s with a space-time yield(STY)up to 16,877 g L^(-1)d^(-1),which is 14.4 times higher than the highest STY of batch reaction reported previously.This continuous-flow process was applied to the synthesis of 6 chiral lactones.In addition,the scaled-up synthesis of 3g was carried out in 6 cascade microreactors continuously for 6 h,demonstrating the feasibility and stability of the 3D continuous-flow process in enzymatic synthesis of optically pure compounds.展开更多
Polysubstituted chiral γ-butyrolactones are the core structural units of many natural products and high value-added flavors and fragrances used in the food and cosmetic industry. Current enzymatic cascade synthesis o...Polysubstituted chiral γ-butyrolactones are the core structural units of many natural products and high value-added flavors and fragrances used in the food and cosmetic industry. Current enzymatic cascade synthesis of these molecules faces the problems of low enzyme activity and phase separation in batch reaction, resulting in low productivity. Herein, we report a new continuous-flow process to synthesize the optically pure Nicotiana tabacum lactone(3S,4S)-4a and whisky lactone(3R,4S)-4b from α,β-unsaturatedγ-ketoesters. A new ene reductase(ER) from Swingsia samuiensi(Ss ER) and a carbonyl reductase(Ss CR)were engineered by directed evolution to improve their activity and thermostability. The continuous-flow preparative reactions were performed in two 3D microfluidic reactors, generating(3S,4S)-4a(99% ee and87% de) and(3R,4S)-4b(99% ee and 98% de) with space-time yields 3 and 7.4 times higher than those of the batch reactions. The significant enhancement in the productivity of enzyme cascade catalysis brought by cutting-edge continuous microfluidic technology will benefit the general multi-enzyme catalytic systems in the future.展开更多
文摘The CIDNP observations indicated that photoreaction of methylfurans with chloranil resulted not only furylmethyl hydroxyphenyl ethers via radical pairs but induced furyl radical isomerization to the derivatives of cyclopropene,propadiene and pyran.
文摘Photochemical reactions of 3-methylindole,carbazole,benzimidazole with fused polycyclic aromatic hydrocarbons in solid state were investigated,The structures of 4 new compounds were confirmed by IR,UV,\+1HNNR,MS and elemental analysis.The structure of compounds 3.6 was established by X-ray crystallography.
基金Project supported by the Science and Technology Project of Heilongjiang Province (No. GA01C201-03).
文摘In this article, polyphosphate-accumulating organisms （PAOs） from a lab-scale continuous-flow two-sludge system was isolated and identified, the different phosphorus accumulation characteristics of the isolates under anoxic and aerobic conditions were investigated. Two kinds of PAOs were both found in the anoxic zones of the two-sludge system, one of them utilized only oxygen as electron aeceptor, and the other one utilized either nitrate or oxygen as electron aeceptor. Of the total eight isolates, five isolates were capable of utilizing both nitrate and oxygen as electron acceptors to uptake phosphorus to some extent. And three of the five isolates showed good phosphorus accumulative capacities both under anoxic or aerobic conditions, two identified as Alcaligenes and one identified as Pseudomonas. Streptococcus was observed weak anoxic phosphorus accumulation because of its weak denitrification capacity, but it showed good phosphorus accumulation capacity under aerobic conditions. One isolates identified as Enterobacteriaceae was proved to be a special species of PAOs, which could only uptake small amounts of phosphorus under anoxic conditions, although its denitrification capacity and aerobic phosphorus accumulation capacity were excellent.
文摘The association between continuous-flow left ventricular assist devices(CF-LVADs)and gastrointestinal(GI)bleeding from angiodysplasia is well recognized.However,the association between continuous-flow biventricular assist devices(CF-BIVADs)and bleeding angiodysplasia is less understood.We report a case of GI bleeding from a patient with a CF-BIVAD.The location of GI bleeding was identified by nuclear red blood cell bleeding scan.The vascular malformation leading to the bleed was identified and localized on angiography and then by pathology.The intensity of bleeding,reflected by number of units of packed red blood cells needed for normalization of hemoglobin,as well as the time to onset of bleeding after transplantation,are similar to that seen in the literature for CF-LVADs and pulsatile BIVADs.While angiography only detected a dilated late draining vein,pathology demonstrated the presence of both arterial and venous dilation in the submucosa,vascular abnormalities characteristic of a late arteriovenous malformation.
基金This work was financially supported by the National Natural Science Foundation of China(grant nos.22122701,21731004,91953201,92153303,21977044,and 21907050)the Natural Science Foundation of Jiangsu Province(grant nos.BK20202004 and BK20190282)the Excellent Research Program of Nanjing University(grant no.ZYJH004).
文摘Photodynamic therapy(PDT)usually shows limited efficacy in solid tumors since traditional PDT is O_(2)^(-)dependent while solid tumors are inherently hypoxic.In addition,hypoxic tumor cells possess antiapoptotic pathways that resist PDT-induced apoptosis.Therefore,developing photosensitizers(PSs)that show low O_(2)^(-)dependency and can induce nonapoptotic cell death pathways is critically needed.Herein,a series of Ru(II)polypyridine complex-based PSs,RuNMe,RuH,and RuCN,were synthesized,and their applications against hypoxic tumor cells through PDT were investigated.All three complexes showthe ability to generate the superoxide anion radical(·O_(2)^(-)),which is the type I photoreaction and less O_(2)^(-)dependent.RuNMe shows the best PDT performance against MCF-7 cells and three-dimensional multicellular spheroids,due to its higher cellular uptake and more reactive oxygen species generation.More importantly,RuNMe-incubated MCF-7 cells show photoinduced ferroptosis as evidenced by glutathione peroxidase 4 downregulation and lipid peroxide accumulation.This work not only develops a novel ferroptosis-inducing Ru(II)complex with the type I PDT process but also offers an effective strategy to solve tumor hypoxia in PDT.
基金financially sponsored by the National Key Research and Development Program of China(No.2021YFC2102804)the National Natural Science Foundation of China(No.22078096)。
文摘A new continuous-flow process for the enzymatic synthesis of optically pureγ-lactones,which are used as flavors and fragrances in the food and cosmetic industries,was developed in a three-dimensional microfluidic reactor.The microchannels(175 mm in length,0.9 mm in depth,and 1.72 mL in volume)were carved precisely inside a single borosilicate glass(90 mm×75 mm×12 mm)with ultrafast femtosecond laser micromachining.The flow field analysis and reaction simulation showed that the mixing of substrates and enzymes was enhanced,allowing the adjustment of residence time in a wide window.SmCR_(V4),a carbonyl reductase with excellent catalytic activity and enantioselectivity towardγ/δ-keto acids,was employed for the asymmetric synthesis of various chiral lactones.30 mmol/L(R)-γ-decalactone(3g)can be obtained in 26 s with a space-time yield(STY)up to 16,877 g L^(-1)d^(-1),which is 14.4 times higher than the highest STY of batch reaction reported previously.This continuous-flow process was applied to the synthesis of 6 chiral lactones.In addition,the scaled-up synthesis of 3g was carried out in 6 cascade microreactors continuously for 6 h,demonstrating the feasibility and stability of the 3D continuous-flow process in enzymatic synthesis of optically pure compounds.
基金financially sponsored by the National Key Research and Development Program of China (No.2021YFC2102804)the National Natural Science Foundation of China(No.22078096)。
文摘Polysubstituted chiral γ-butyrolactones are the core structural units of many natural products and high value-added flavors and fragrances used in the food and cosmetic industry. Current enzymatic cascade synthesis of these molecules faces the problems of low enzyme activity and phase separation in batch reaction, resulting in low productivity. Herein, we report a new continuous-flow process to synthesize the optically pure Nicotiana tabacum lactone(3S,4S)-4a and whisky lactone(3R,4S)-4b from α,β-unsaturatedγ-ketoesters. A new ene reductase(ER) from Swingsia samuiensi(Ss ER) and a carbonyl reductase(Ss CR)were engineered by directed evolution to improve their activity and thermostability. The continuous-flow preparative reactions were performed in two 3D microfluidic reactors, generating(3S,4S)-4a(99% ee and87% de) and(3R,4S)-4b(99% ee and 98% de) with space-time yields 3 and 7.4 times higher than those of the batch reactions. The significant enhancement in the productivity of enzyme cascade catalysis brought by cutting-edge continuous microfluidic technology will benefit the general multi-enzyme catalytic systems in the future.
