Cerebrovascular accident（CVA）or stroke is one of the world＇s leading causes of death and permanent disability.The high social and medical costs associated with this pathology mean there is an urgent need to find ef...Cerebrovascular accident（CVA）or stroke is one of the world＇s leading causes of death and permanent disability.The high social and medical costs associated with this pathology mean there is an urgent need to find effective therapies.Occlusion of the middle cerebral artery（MCAO）,mainly by clots,is the origin of most CVAs in humans.展开更多
A new method is proposed to determine the amplification factor for 2-hydroxy ethylperoxy radicals （HOC2H4O2·） in chemical amplifier. The radical source comes from the reaction of excess ethene with HO· rad...A new method is proposed to determine the amplification factor for 2-hydroxy ethylperoxy radicals （HOC2H4O2·） in chemical amplifier. The radical source comes from the reaction of excess ethene with HO· radicals generated in the photolysis of water vapor at the wave length of 185 nm in air in a flow tube. This produces a radical source which contains equal amount of HO2·and HOC2H4O2·. The amplification factor is derived from the slopes of the lines between produced NO2 in chemical amplifier and total initial radical concentrations measured for the source of HO2· and that of the same amount of HO2· and HOC2H4O2· respectively. The amplification factor of HOC2H4O2· was similar to that of HO2·, indicating that HOC2H4O2· can be measured with the same sensitivity as HO2· by chemical amplifier.展开更多
The optically active R-4-phenyl-2-hydroxy butyrates were prepared by esterification of the racemic acid or transesterification of the racemic ester catalyzed by lipase from Candida cyclindra (CCL) in organic media.
The interaction of N-(2-methyl thiophenyl)-2-hydroxy-1-naphthaldimine (NMTHN) with tin dioxide nanoparticles (SnO2 NPs) has been investigated by spectroscopic tools such as absorption and fluorescence spectroscopy. Ab...The interaction of N-(2-methyl thiophenyl)-2-hydroxy-1-naphthaldimine (NMTHN) with tin dioxide nanoparticles (SnO2 NPs) has been investigated by spectroscopic tools such as absorption and fluorescence spectroscopy. Absorption spectroscopy reveals the formation of ground state complex. Fluorescence spectroscopy has been used to study the signatures of fluorescence quenching. SnO2 NPs are found to quench the intrinsic fluorescence of NMTHN via static and dynamic quenching. The deviation from linearity in the Stern-Volmer plot has been observed.展开更多
Eight new brominated 2＇（4＇）-nitro-3-hydroxy diphenyl ethers have been designed and synthesized. The structures of new compounds were confirmed by ^1H NMR, IR and HRMS. The bioactivity tests showed that these compo...Eight new brominated 2＇（4＇）-nitro-3-hydroxy diphenyl ethers have been designed and synthesized. The structures of new compounds were confirmed by ^1H NMR, IR and HRMS. The bioactivity tests showed that these compounds possessed antibacterial activities against the tested bacteria. These new compounds cannot be transformed into dioxins when they were manufactured and used.展开更多
We report here a generic,green synthesis of 17 valuable syn-aryl-(2S,3R)-2–chloro-3–hydroxy esters(syn-(2S,3R)-1)in 73%-99%isolated yields along with 6.1:1–83:1 dr and 31%~>99%ee,through dynamic reductive kineti...We report here a generic,green synthesis of 17 valuable syn-aryl-(2S,3R)-2–chloro-3–hydroxy esters(syn-(2S,3R)-1)in 73%-99%isolated yields along with 6.1:1–83:1 dr and 31%~>99%ee,through dynamic reductive kinetic resolution of racemic arylα–chloroβ-keto esters(2)catalyzed by an engineered ketoreductase which was obtained via ep PCR-based directed evolution.The hectogram scale synthesis of syn-(2S,3R)-1b at a substrate concentration of 120 g/L showcased the application potential of the biocatalytic method developed presently.展开更多
In the presence of molecular iodine, the reaction of alkenes with diselenides proceeds efficiently under air and at room temperature in mixed solvent MeCN/H2O, which affording β-hydroxy selenides with high regioselec...In the presence of molecular iodine, the reaction of alkenes with diselenides proceeds efficiently under air and at room temperature in mixed solvent MeCN/H2O, which affording β-hydroxy selenides with high regioselectivity and in good to excellent yields. This iodine-mediated vicinal difunctionalization of alkenes requires mild reaction conditions and is a simple procedure, which extends the synthetic application of molecular iodine in organic synthesis.展开更多
To investigate the malondialdehyde（MDA） levels,paraoxonase1（PON1） activity and 8-hydroxy 2-deoxyguanosine（8-OHd G） levels in the primary open angle glaucoma（POAG） patient.Blood samples from 52 healthy individu...To investigate the malondialdehyde（MDA） levels,paraoxonase1（PON1） activity and 8-hydroxy 2-deoxyguanosine（8-OHd G） levels in the primary open angle glaucoma（POAG） patient.Blood samples from 52 healthy individuals and 53 patients with POAG were analyzed for MDA and 8-OHd G by high-performance liquid chromatography（HPLC） and PON1 by spectrophotometry.The data obtained were analyzed statistically.MDA levels were 10.46±8.4 and 4.70±1.79 μmol; PON1 levels were 121 ±39.55 and 161.62 ±60.22 U/m L; and 8-OHd G values were1.32 ±0.53/10~6 d G and 0.47 ±0.27/10~6 d G in the POAG patients and the control group,respectively.The difference was significant in MDA levels,8-OHd G levels and PON1 activity in POAG patients in comparison with controls（P 〈0.001）.We concluded that the observed increase in MDA and 8-OHd G levels may be correlated with decreased PON1 activity.Oxidative stress plays an important role in glaucoma development.展开更多
An asymmetric hydrogenation of α-oxymethylcinnamic acids was developed by using chiral spiro phosphineoxazoline/iridium complexes as catalysts to prepare β^(2)-hydroxycarboxylic acids with high reactivity(TON up to ...An asymmetric hydrogenation of α-oxymethylcinnamic acids was developed by using chiral spiro phosphineoxazoline/iridium complexes as catalysts to prepare β^(2)-hydroxycarboxylic acids with high reactivity(TON up to 2000)and excellent enantioselectivity(up to 99.5%ee).By using this highly efficient asymmetric hydrogenation as a key step,a concise total synthesis of natural product homoisoflavone(S)-(+)-4 was accomplished.展开更多
In order to reduce the amount of volumetric shrinkage that occurs in dental composites as a result of curing,a new kind of dental matrix resin combining bisphenol-S-bis(3-meth acry late-2-hydroxy propyl)ether(BisS-GMA...In order to reduce the amount of volumetric shrinkage that occurs in dental composites as a result of curing,a new kind of dental matrix resin combining bisphenol-S-bis(3-meth acry late-2-hydroxy propyl)ether(BisS-GMA)with the expanding monomer unsaturated spiro orthoesters 2-methylene-1,4,6-trispiro[4,4]nonane(SOE)was prepared,with triethylene glycol dimethacrylate(TEGDMA)as diluent.CQ(camphorquinone)of 1wt%and DMAEMA(2-(dimethylamino)ethyl meth acrylate)of 2wt%were used as photoinitiation system to initiate the copolymerization of the matrix resins.The performance including volumetric shrinkage,degree of conversion and condition of the ring-opening reaction of SOE,as well as curing time and the tensile bond strength were investigated respectively by the dilatometer,Fourier transfer infrared,the universal testing machine,and so on.The ring-opening polymerization of SOE occurred.Meanwhile,the obtain copolymers were crosslinked.The matrix resin containing BisS-GMA and SOE showed a reduced amount of volumetric shrinkage at 1.52%,which is a promising strategy for obtaining a polymer with a low amount of volumetric shrinkage.Furthermore,the other properties were not compromised.展开更多
文摘Cerebrovascular accident（CVA）or stroke is one of the world＇s leading causes of death and permanent disability.The high social and medical costs associated with this pathology mean there is an urgent need to find effective therapies.Occlusion of the middle cerebral artery（MCAO）,mainly by clots,is the origin of most CVAs in humans.
文摘A new method is proposed to determine the amplification factor for 2-hydroxy ethylperoxy radicals （HOC2H4O2·） in chemical amplifier. The radical source comes from the reaction of excess ethene with HO· radicals generated in the photolysis of water vapor at the wave length of 185 nm in air in a flow tube. This produces a radical source which contains equal amount of HO2·and HOC2H4O2·. The amplification factor is derived from the slopes of the lines between produced NO2 in chemical amplifier and total initial radical concentrations measured for the source of HO2· and that of the same amount of HO2· and HOC2H4O2· respectively. The amplification factor of HOC2H4O2· was similar to that of HO2·, indicating that HOC2H4O2· can be measured with the same sensitivity as HO2· by chemical amplifier.
文摘The optically active R-4-phenyl-2-hydroxy butyrates were prepared by esterification of the racemic acid or transesterification of the racemic ester catalyzed by lipase from Candida cyclindra (CCL) in organic media.
文摘The interaction of N-(2-methyl thiophenyl)-2-hydroxy-1-naphthaldimine (NMTHN) with tin dioxide nanoparticles (SnO2 NPs) has been investigated by spectroscopic tools such as absorption and fluorescence spectroscopy. Absorption spectroscopy reveals the formation of ground state complex. Fluorescence spectroscopy has been used to study the signatures of fluorescence quenching. SnO2 NPs are found to quench the intrinsic fluorescence of NMTHN via static and dynamic quenching. The deviation from linearity in the Stern-Volmer plot has been observed.
文摘Eight new brominated 2＇（4＇）-nitro-3-hydroxy diphenyl ethers have been designed and synthesized. The structures of new compounds were confirmed by ^1H NMR, IR and HRMS. The bioactivity tests showed that these compounds possessed antibacterial activities against the tested bacteria. These new compounds cannot be transformed into dioxins when they were manufactured and used.
基金The National Key Research and Development Program of China(Nos.2021YFA0911400 and 2021YFF0600704)the National Natural Science Foundation of China(Nos.22071033 and 21801047)are acknowledged for the financial supports。
文摘We report here a generic,green synthesis of 17 valuable syn-aryl-(2S,3R)-2–chloro-3–hydroxy esters(syn-(2S,3R)-1)in 73%-99%isolated yields along with 6.1:1–83:1 dr and 31%~>99%ee,through dynamic reductive kinetic resolution of racemic arylα–chloroβ-keto esters(2)catalyzed by an engineered ketoreductase which was obtained via ep PCR-based directed evolution.The hectogram scale synthesis of syn-(2S,3R)-1b at a substrate concentration of 120 g/L showcased the application potential of the biocatalytic method developed presently.
文摘In the presence of molecular iodine, the reaction of alkenes with diselenides proceeds efficiently under air and at room temperature in mixed solvent MeCN/H2O, which affording β-hydroxy selenides with high regioselectivity and in good to excellent yields. This iodine-mediated vicinal difunctionalization of alkenes requires mild reaction conditions and is a simple procedure, which extends the synthetic application of molecular iodine in organic synthesis.
文摘To investigate the malondialdehyde（MDA） levels,paraoxonase1（PON1） activity and 8-hydroxy 2-deoxyguanosine（8-OHd G） levels in the primary open angle glaucoma（POAG） patient.Blood samples from 52 healthy individuals and 53 patients with POAG were analyzed for MDA and 8-OHd G by high-performance liquid chromatography（HPLC） and PON1 by spectrophotometry.The data obtained were analyzed statistically.MDA levels were 10.46±8.4 and 4.70±1.79 μmol; PON1 levels were 121 ±39.55 and 161.62 ±60.22 U/m L; and 8-OHd G values were1.32 ±0.53/10~6 d G and 0.47 ±0.27/10~6 d G in the POAG patients and the control group,respectively.The difference was significant in MDA levels,8-OHd G levels and PON1 activity in POAG patients in comparison with controls（P 〈0.001）.We concluded that the observed increase in MDA and 8-OHd G levels may be correlated with decreased PON1 activity.Oxidative stress plays an important role in glaucoma development.
基金the National Natural Science Foundation of China,the National Basic Research Program of China(No.2012CB821600)the“111”Project(No.B06005)of the Ministry of Education of China for financial support.
文摘An asymmetric hydrogenation of α-oxymethylcinnamic acids was developed by using chiral spiro phosphineoxazoline/iridium complexes as catalysts to prepare β^(2)-hydroxycarboxylic acids with high reactivity(TON up to 2000)and excellent enantioselectivity(up to 99.5%ee).By using this highly efficient asymmetric hydrogenation as a key step,a concise total synthesis of natural product homoisoflavone(S)-(+)-4 was accomplished.
基金Funded by the National Natural Science Foundation of China(No.50673065)
文摘In order to reduce the amount of volumetric shrinkage that occurs in dental composites as a result of curing,a new kind of dental matrix resin combining bisphenol-S-bis(3-meth acry late-2-hydroxy propyl)ether(BisS-GMA)with the expanding monomer unsaturated spiro orthoesters 2-methylene-1,4,6-trispiro[4,4]nonane(SOE)was prepared,with triethylene glycol dimethacrylate(TEGDMA)as diluent.CQ(camphorquinone)of 1wt%and DMAEMA(2-(dimethylamino)ethyl meth acrylate)of 2wt%were used as photoinitiation system to initiate the copolymerization of the matrix resins.The performance including volumetric shrinkage,degree of conversion and condition of the ring-opening reaction of SOE,as well as curing time and the tensile bond strength were investigated respectively by the dilatometer,Fourier transfer infrared,the universal testing machine,and so on.The ring-opening polymerization of SOE occurred.Meanwhile,the obtain copolymers were crosslinked.The matrix resin containing BisS-GMA and SOE showed a reduced amount of volumetric shrinkage at 1.52%,which is a promising strategy for obtaining a polymer with a low amount of volumetric shrinkage.Furthermore,the other properties were not compromised.
