The transformation of aldose to ketose or common sugars into rare saccharides,including rare ketoses and aldoses,is of great value and interest to the food industry and for saccharidic biomass utilization,medicine,and...The transformation of aldose to ketose or common sugars into rare saccharides,including rare ketoses and aldoses,is of great value and interest to the food industry and for saccharidic biomass utilization,medicine,and the synthesis of drugs.Nowadays,high-fructose corn syrup(HFCS)is industrially produced in more than 10 million tons annually using immobilized glucose isomerase.Some low-calorie saccharides such as tagatose and psicose,which are becoming popular sweeteners,have also been produced on a pilot scale in order to replace sucrose and HFCS.However,current catalysts and catalytic processes are still difficult to utilize in biomass conversion and also have strong substrate dependence in producing high-value,rare sugars.Considering the specific reaction properties of saccharides and catalysts,since the pioneering discovery by Fischer,various catalysts and catalytic systems have been discovered or developed in attempts to extend the reaction pathways,improve the reaction efficiency,and to potentially produce commercial products.In this review,we trace the history of sugar isomerization/epimerization reactions and summarize the important breakthroughs for each reaction as well as the difficulties that remain unresolved to date.展开更多
A novel and convenient iron-catalyzed ketonization of 2-aryl-1,1-dibromoalkenes with KOAc has been achieved.A series ofα-acetoxy aryl ketones were prepared with moderate yields via 2-carbon position functionalization...A novel and convenient iron-catalyzed ketonization of 2-aryl-1,1-dibromoalkenes with KOAc has been achieved.A series ofα-acetoxy aryl ketones were prepared with moderate yields via 2-carbon position functionalization of 2-aryl-1,1-dibromoalkenes.展开更多
Mental disorders such as depression and anxiety inflict significant burdens on individuals and society.Commonly prescribed treatments often involve cognitive therapy and medications.However,for patients resistant to t...Mental disorders such as depression and anxiety inflict significant burdens on individuals and society.Commonly prescribed treatments often involve cognitive therapy and medications.However,for patients resistant to these conventional methods,alternative therapies like the Ketogenic Diet(KD)offer a promising avenue.KD and its key metabolite,β-hydroxybutyrate(BHB),have been hypothesized to alleviate mental disorders through antiinflammatory actions,a crucial pathway in the pathophysiology of depression.This mini-review examines 15 clinical trials exploring the influence of KD and BHB on inflammation and their potential roles in managing mental disorders.Both human and animal studies were scrutinized to elucidate possible cellular and molecular mechanisms.Out of the 15 trials,10 reported reduced levels of at least one inflammatory mediator or mRNA post KD or BHB treatment,while two observed an elevation in anti-inflammatory agents.These findings suggest that KD and BHB could modulate cellular inflammatory pathways,highlighting their potential for therapeutic application in mental disorders.展开更多
“As a non-invasive alternative to the traditional finger-prick blood ketone testing devices,boasting a high level of accuracy comparable to industrial gold standards typically attainable only through bulky and expens...“As a non-invasive alternative to the traditional finger-prick blood ketone testing devices,boasting a high level of accuracy comparable to industrial gold standards typically attainable only through bulky and expensive specialty equipment,we proudly introduce the world’s first-of-its-kind handheld breath ketone(BrAce)analyser,empowered by our patented disruptive photonic sensing technologies.These innovations are aimed at providing a more effective approach to managing diabetes and ketosis(fat metabolism),”said Christine Yip,founder and CEO of AusMed Global Limited,during a recent interview with China’s Foreign Trade magazine.展开更多
A new and simple route for the synthesis of α,β-unsaturated ketones via cleavage of the C-C(O)C single bond of monoalkylated β-diketone has been described. The reaction was catalyzed by copper, a cheap transition m...A new and simple route for the synthesis of α,β-unsaturated ketones via cleavage of the C-C(O)C single bond of monoalkylated β-diketone has been described. The reaction was catalyzed by copper, a cheap transition metal in a weakly basic medium (K<sub>3</sub>PO<sub>4</sub>) at room temperature. To carry out this study, we first had to synthesize the monoalkylated β-diketones 1. Afterwards, α,β-unsaturated ketones 2 were obtained with high yields around 80%. Finally, all the products were characterized by 1H NMR, 13C NMR, and HRMS spectra. .展开更多
Macrocyclic arylene ether ketone was characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrum(MALDI-TOF MS)combining with nuclear magnetic resonance(NMR)spectra.No any more fragment io...Macrocyclic arylene ether ketone was characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrum(MALDI-TOF MS)combining with nuclear magnetic resonance(NMR)spectra.No any more fragment ionization peaks except for the molecular ion peak from the mass spectrum.The structure of macrocyclic dimmer was further affirmed by the NMR spectra through the analysis of chemical shifts.The MALDI-TOF MS combining with NMR technique was found an important tool to characterized Macrocyclic aromatic oligomers.展开更多
The combination of a low cost source of Biofine's levulinic acid with available way of valeric acid synthesis opens up new opportunities for valeric acid as a promising bio-derived source for synthesis of valuable co...The combination of a low cost source of Biofine's levulinic acid with available way of valeric acid synthesis opens up new opportunities for valeric acid as a promising bio-derived source for synthesis of valuable compounds for transportation sector. The present review illustrates the development of different approaches to one–pot synthesis of fuel-like alkanes from lignocellulose derived carboxylic acids where particular focus is given to valeric acid consecutive decarboxylative coupling(ketonization) and ketone hydrodeoxygenation in a single reactor over one catalyst bed. The key factors that influence the catalytic performance on both ketonization and hydrodeoxygenation steps as well as their cross-influence will be clarified to provide insights for the design of more efficient catalysts for the one-pot transformation. Valeric acid is considered as a potential acid source from viewpoint of cost effectiveness and feasibility of such transformation with reasonable alkane yield. The both reaction mechanisms and kinetics will also be discussed to understand deeply how the selective C–C coupling and following C=O hydrogenation can be achieved.展开更多
Di(4-bromophenyl)ketone and various aromatic diamines as the monomers,a series of novel poly(imino ketone)s (PIKs)have been synthesized via palladium-catalyzed aryl amination,which is Hartwig-Buchwald polycondensation...Di(4-bromophenyl)ketone and various aromatic diamines as the monomers,a series of novel poly(imino ketone)s (PIKs)have been synthesized via palladium-catalyzed aryl amination,which is Hartwig-Buchwald polycondensation reaction.The structures of PIKs are characterized by means of elemental analysis,FT-IR,~1H-NMR and UV-Vis spectroscopy. The results show a good agreement with the proposed structure.The general properties of PIKs are studied by DSC,TG and wide-angle X-ray diffraction,the solubility behavior is...展开更多
Methyl isobutyl ketone(MIBK) is widely used as extraction agent in hydrometallurgy. As it has a definite solubility in water, so when using MIBK as extraction agent, there will be MIBK in stripping solutions inevitabl...Methyl isobutyl ketone(MIBK) is widely used as extraction agent in hydrometallurgy. As it has a definite solubility in water, so when using MIBK as extraction agent, there will be MIBK in stripping solutions inevitably, which not only pollutes working conditions, but also affects the quality of ultimate product. In order to remove MIBK from aqueous solutions, the means of flat vacuum membrane distillation(VMD) is studied in the paper. The area of the membrane used in the study is 0.02 m 2, the initial volume of feed is 2 L, each experiment was conducted over a time period of 60 120 min. The influences of the factors such as temperature(34.8 55.0 ℃); pressure in the permeate side(10.67 14.67 kPa) and feed flow rate(27.8 69.4 mL/s) were experimentally studied. Increasing the temperature or reducing the pressure in the permeate side results in a faster removal of MIBK; however there is a decrease in removal factor β , increasing the feed flow rate results in a faster removal of MIBK and an increase of removal factor β , especially in the range of lower flow rate. The study indicates that the aim of MIBK removal and recycle from dilute aqueous solutions can be achieved by VMD.展开更多
Chloromethylated poly(phthalazinone ether sulfone ketone) (CMPPESK) was prepared from poly(phthalazinone ether sulfone ketone) (PPESK) using chloromethyl octyl ethers (CMOE) with lower toxicity as chlorometh...Chloromethylated poly(phthalazinone ether sulfone ketone) (CMPPESK) was prepared from poly(phthalazinone ether sulfone ketone) (PPESK) using chloromethyl octyl ethers (CMOE) with lower toxicity as chloromethylated regent. CMPPESK was soluble in N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc) and chloroform. Quaternized poly(phthalazinone ether sulfone ketone) (QAPPESK) was prepared from CMPPESK by quaternization. QAPPESK had excellent solvent resistance, which was only partly soluble in sulfuric acid (98%) and swollen in N,N-dimethylformamide (DMF). The vanadium redox flow battery (V-RFB) using QAPPESK anion-exchange membrane had better performance with 88.3% of overall energy efficiency.展开更多
Photo-grafting of hydrophilic monomer was used to enhance the hydrophilicity of poly(ether ether ketone) (PEEK) with the aim of extending its applications to biological fields. PEEK sheets were surface modified by...Photo-grafting of hydrophilic monomer was used to enhance the hydrophilicity of poly(ether ether ketone) (PEEK) with the aim of extending its applications to biological fields. PEEK sheets were surface modified by grafting of acrylamide(AAm) with ultraviolet(UV) irradiation in the presence or absence of benzophenone(BP). The effects of BP, irradiation time and monomer concentration on the surface wettability of PEEK were investigated. Characteriza tion of modified PEEK using scanning electron microscopy(SEM), energy-disperse spectrometer(EDS) and water contact angle measurements shows that AAm was successfully grafted on PEEK surface both in presence and absence of BP. With the increase in irradiation time and monomer concentration, contact angles decrease to as low as 30°, demonstrating a significant improvement of surface hydrophilicity. In agreement with the decrease in contact angle, under identical conditions, the nitrogen concentration increases, suggesting the increase in grafting degree of the grafting polymerization. This investigation demonstrates a self-initiation of PEEK due to its BP-like structure in the backbone of the polymer. Though the graft polymerization proceeds more readily in the presence of BP, the self-initiated graft polymerization is clearly observed.展开更多
A highly efficient green protocol for the preparation of bis-indolylmethanes,bis-2-methylindolylmethanes,bis-1-methylindolylmethanes and 3,3 -diindolyloxindole derivatives from the reaction of indoles with various ald...A highly efficient green protocol for the preparation of bis-indolylmethanes,bis-2-methylindolylmethanes,bis-1-methylindolylmethanes and 3,3 -diindolyloxindole derivatives from the reaction of indoles with various aldehydes and ketones in the presence of cellulose sulfuric acid under solvent-free conditions is reported.The significant features of this procedure are high yields of the products,mild reaction,solvent-free condition and non-toxicity of the catalyst.展开更多
Michael addition of indole and pyrrole to a variety of α, β-unsaturated ketones was efficiently promoted by a catalytic amount of GaCl3 in aqueous media to afford the corresponding products in good to excellent yields.
A novel La complex with methyl-2-pyridyl ketone benzoyl hydrazone has been synthesized and determined by single crystal X-ray diffraction. The crystal is monoclinic with space group C2/c, a =1 7081(3) nm, b =1 ...A novel La complex with methyl-2-pyridyl ketone benzoyl hydrazone has been synthesized and determined by single crystal X-ray diffraction. The crystal is monoclinic with space group C2/c, a =1 7081(3) nm, b =1 5660(3) nm, c =1 3512(3) nm, α=90 00°, β=94 39(1)°, γ=90 00°, V =3 6037(12) nm 3, Z =4 . The complex is a ten-coordinated one with a lanthanum ion surrounded by a N 4O 6 set. The crystal structure is stabilized by hydrogen bonds between water molecules and NO - 3 anions.展开更多
The efficient, green, facile, mild and straightforward conversion procedure for the oxidation of cyclic ketones to lactones at room temperature utilizing potassium peroxydisulfate (K2S2O8) in acidic media is satisfa...The efficient, green, facile, mild and straightforward conversion procedure for the oxidation of cyclic ketones to lactones at room temperature utilizing potassium peroxydisulfate (K2S2O8) in acidic media is satisfactory to high yields without using traditional chlorinated solvents is reported. This oxidative reagent is cheap and friendly environmental procedure for industrial purposes than use of organic peracids.展开更多
Green,mild and efficient iodination of hydroxylated aromatic aldehydes and ketones using iodine and iodic acid in the solidstate by grinding under solvent-free conditions at room temperature.This method provides sever...Green,mild and efficient iodination of hydroxylated aromatic aldehydes and ketones using iodine and iodic acid in the solidstate by grinding under solvent-free conditions at room temperature.This method provides several advantages such as environmentally friendly,short reaction times,high yields,non-hazardous and simple work-up procedure.展开更多
AIM: To identify plasma metabolites used as biomarkers in order to distinguish cirrhotics from controls and encephalopathics.METHODS: A clinical study involving stable cirrhotic patients with and without overt hepatic...AIM: To identify plasma metabolites used as biomarkers in order to distinguish cirrhotics from controls and encephalopathics.METHODS: A clinical study involving stable cirrhotic patients with and without overt hepatic encephalopathy was designed. A control group of healthy volunteers was used. Plasma from those patients was analysed using 1H- nuclear magnetic resonance spectroscopy. We used the Carr Purcell Meiboom Gill sequence to process the sample spectra at ambient probe temperature. We used a gated secondary irradiation field for water signal suppression. Samples were calibrated and referenced using the sodium trimethyl silyl propionate peak at 0.00 ppm. For each sample 128 transients(FID's) were acquired into 32 K complex data points over a spectral width of 6 KHz. 30 degree pulses were applied with an acquisition time of 4.0 s in order to achieve better resolution, followed by a recovery delay of 12 s, to allow for complete relaxation and recovery of the magnetisation. A metabolic profile was created for stable cirrhotic patients without signs of overt hepatic encephalopathy and encephalopathic patients as well as healthy controls. Stepwise discriminant analysis was then used and discriminant factors were created to differentiate between the three groups.RESULTS: Eighteen stabled cirrhotic patients, eighteen patients with overt hepatic encephalopathy and seventeen healthy volunteers were recruited. Patients with cirrhosis had significantly impaired ketone body metabolism, urea synthesis and gluconeogenesis. This was demonstrated by higher concentrations of acetoacetate(0.23 ± 0.02 vs 0.05 ± 0.00, P < 0.01), and b-hydroxybutarate(0.58 ± 0.14 vs 0.08 ± 0.00, P < 0.01), lower concentrations of glutamine(0.44 ± 0.08 vs 0.63 ± 0.03, P < 0.05), histidine(0.16 ± 0.01 vs 0.36 ± 0.04, P < 0.01) and arginine(0.08 ± 0.01 vs 0.14 ± 0.02, P < 0.03) and higher concentrations of glutamate(1.36 ± 0.25 vs 0.58 ± 0.04, P < 0.01), lactate(1.53 ± 0.11 vs 0.42 ± 0.05, P < 0.01), pyruvate(0.11 ± 0.02 vs 0.03 ± 0.00, P < 0.01) threonine(0.39 ± 0.02 vs 0.08 ± 0.01, P < 0.01) and aspartate(0.37 ± 0.03 vs 0.03 ± 0.01). A five metabolite signature by stepwise discriminant analysis could separate between controls and cirrhotic patients with an accuracy of 98%. In patients with encephalopathy we observed further derangement of ketone body metabolism, impaired production of glycerol and myoinositol, reversal of Fischer's ratio and impaired glutamine production as demonstrated by lower b-hydroxybutyrate(0.58 ± 0.14 vs 0.16 ± 0.02, P < 0.0002), higher acetoacetate(0.23 ± 0.02 vs 0.41 ± 0.16, P < 0.05), leucine(0.33 ± 0.02 vs 0.49 ± 0.05, P < 0.005) and isoleucine(0.12 ± 0.02 vs 0.27 ± 0.02, P < 0.0004) and lower glutamine(0.44 ± 0.08 vs 0.36 ± 0.04, P < 0.013), glycerol(0.53 ± 0.03 vs 0.19 ± 0.02, P < 0.000) and myoinositol(0.36 ± 0.04 vs 0.18 ± 0.02, P < 0.010) concentrations. A four metabolite signature by stepwise discriminant analysis could separate between encephalopathic and cirrhotic patients with an accuracy of 87%.CONCLUSION: Patients with cirrhosis and patients with hepatic encephalopathy exhibit distinct metabolic abnormalities and the use of metabonomics can select biomarkers for these diseases.展开更多
基金Financial support by Dual Initiative Project of Jiangsu Province and Changzhou University is gratefully acknowledgedSample analysis supported by Analysis and Testing Center,NERC Biomass of Changzhou University was also greatly acknowledged.
文摘The transformation of aldose to ketose or common sugars into rare saccharides,including rare ketoses and aldoses,is of great value and interest to the food industry and for saccharidic biomass utilization,medicine,and the synthesis of drugs.Nowadays,high-fructose corn syrup(HFCS)is industrially produced in more than 10 million tons annually using immobilized glucose isomerase.Some low-calorie saccharides such as tagatose and psicose,which are becoming popular sweeteners,have also been produced on a pilot scale in order to replace sucrose and HFCS.However,current catalysts and catalytic processes are still difficult to utilize in biomass conversion and also have strong substrate dependence in producing high-value,rare sugars.Considering the specific reaction properties of saccharides and catalysts,since the pioneering discovery by Fischer,various catalysts and catalytic systems have been discovered or developed in attempts to extend the reaction pathways,improve the reaction efficiency,and to potentially produce commercial products.In this review,we trace the history of sugar isomerization/epimerization reactions and summarize the important breakthroughs for each reaction as well as the difficulties that remain unresolved to date.
基金supported by Natural Science Foundation of China(No,30873153)the Key Projects of Shanghai in Biomedical(No.08431902700)the Scientific Research Foundation of State Education Ministry for the Returned Overseas Chinese Scholars
文摘A novel and convenient iron-catalyzed ketonization of 2-aryl-1,1-dibromoalkenes with KOAc has been achieved.A series ofα-acetoxy aryl ketones were prepared with moderate yields via 2-carbon position functionalization of 2-aryl-1,1-dibromoalkenes.
基金Department of Science and Technology of Jilin Province,No.20210402019GH,Fundamental Research Funds of Jilin University,Seed Fund,No.2021ZZ021Jilin Province Education Science Planning Project,No.GH21006 and the Fundamental Research Funds for the Central Universities,No.2022CXTD03.
文摘Mental disorders such as depression and anxiety inflict significant burdens on individuals and society.Commonly prescribed treatments often involve cognitive therapy and medications.However,for patients resistant to these conventional methods,alternative therapies like the Ketogenic Diet(KD)offer a promising avenue.KD and its key metabolite,β-hydroxybutyrate(BHB),have been hypothesized to alleviate mental disorders through antiinflammatory actions,a crucial pathway in the pathophysiology of depression.This mini-review examines 15 clinical trials exploring the influence of KD and BHB on inflammation and their potential roles in managing mental disorders.Both human and animal studies were scrutinized to elucidate possible cellular and molecular mechanisms.Out of the 15 trials,10 reported reduced levels of at least one inflammatory mediator or mRNA post KD or BHB treatment,while two observed an elevation in anti-inflammatory agents.These findings suggest that KD and BHB could modulate cellular inflammatory pathways,highlighting their potential for therapeutic application in mental disorders.
文摘“As a non-invasive alternative to the traditional finger-prick blood ketone testing devices,boasting a high level of accuracy comparable to industrial gold standards typically attainable only through bulky and expensive specialty equipment,we proudly introduce the world’s first-of-its-kind handheld breath ketone(BrAce)analyser,empowered by our patented disruptive photonic sensing technologies.These innovations are aimed at providing a more effective approach to managing diabetes and ketosis(fat metabolism),”said Christine Yip,founder and CEO of AusMed Global Limited,during a recent interview with China’s Foreign Trade magazine.
文摘A new and simple route for the synthesis of α,β-unsaturated ketones via cleavage of the C-C(O)C single bond of monoalkylated β-diketone has been described. The reaction was catalyzed by copper, a cheap transition metal in a weakly basic medium (K<sub>3</sub>PO<sub>4</sub>) at room temperature. To carry out this study, we first had to synthesize the monoalkylated β-diketones 1. Afterwards, α,β-unsaturated ketones 2 were obtained with high yields around 80%. Finally, all the products were characterized by 1H NMR, 13C NMR, and HRMS spectra. .
文摘Macrocyclic arylene ether ketone was characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrum(MALDI-TOF MS)combining with nuclear magnetic resonance(NMR)spectra.No any more fragment ionization peaks except for the molecular ion peak from the mass spectrum.The structure of macrocyclic dimmer was further affirmed by the NMR spectra through the analysis of chemical shifts.The MALDI-TOF MS combining with NMR technique was found an important tool to characterized Macrocyclic aromatic oligomers.
基金partly supported by Russian Academy of Science Project No. V.46.4.4Part of work related to metal oxides was supported by RFBR grant 15-03-09329
文摘The combination of a low cost source of Biofine's levulinic acid with available way of valeric acid synthesis opens up new opportunities for valeric acid as a promising bio-derived source for synthesis of valuable compounds for transportation sector. The present review illustrates the development of different approaches to one–pot synthesis of fuel-like alkanes from lignocellulose derived carboxylic acids where particular focus is given to valeric acid consecutive decarboxylative coupling(ketonization) and ketone hydrodeoxygenation in a single reactor over one catalyst bed. The key factors that influence the catalytic performance on both ketonization and hydrodeoxygenation steps as well as their cross-influence will be clarified to provide insights for the design of more efficient catalysts for the one-pot transformation. Valeric acid is considered as a potential acid source from viewpoint of cost effectiveness and feasibility of such transformation with reasonable alkane yield. The both reaction mechanisms and kinetics will also be discussed to understand deeply how the selective C–C coupling and following C=O hydrogenation can be achieved.
基金This work was financially supported by the National Natural Science Foundation of China(No.15076017).
文摘Di(4-bromophenyl)ketone and various aromatic diamines as the monomers,a series of novel poly(imino ketone)s (PIKs)have been synthesized via palladium-catalyzed aryl amination,which is Hartwig-Buchwald polycondensation reaction.The structures of PIKs are characterized by means of elemental analysis,FT-IR,~1H-NMR and UV-Vis spectroscopy. The results show a good agreement with the proposed structure.The general properties of PIKs are studied by DSC,TG and wide-angle X-ray diffraction,the solubility behavior is...
文摘Methyl isobutyl ketone(MIBK) is widely used as extraction agent in hydrometallurgy. As it has a definite solubility in water, so when using MIBK as extraction agent, there will be MIBK in stripping solutions inevitably, which not only pollutes working conditions, but also affects the quality of ultimate product. In order to remove MIBK from aqueous solutions, the means of flat vacuum membrane distillation(VMD) is studied in the paper. The area of the membrane used in the study is 0.02 m 2, the initial volume of feed is 2 L, each experiment was conducted over a time period of 60 120 min. The influences of the factors such as temperature(34.8 55.0 ℃); pressure in the permeate side(10.67 14.67 kPa) and feed flow rate(27.8 69.4 mL/s) were experimentally studied. Increasing the temperature or reducing the pressure in the permeate side results in a faster removal of MIBK; however there is a decrease in removal factor β , increasing the feed flow rate results in a faster removal of MIBK and an increase of removal factor β , especially in the range of lower flow rate. The study indicates that the aim of MIBK removal and recycle from dilute aqueous solutions can be achieved by VMD.
基金partly financed by the Major State Basic Research Development Program of China(No.2003 CB615700)the National Natural Science Foundation of China(No.20604005).
文摘Chloromethylated poly(phthalazinone ether sulfone ketone) (CMPPESK) was prepared from poly(phthalazinone ether sulfone ketone) (PPESK) using chloromethyl octyl ethers (CMOE) with lower toxicity as chloromethylated regent. CMPPESK was soluble in N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc) and chloroform. Quaternized poly(phthalazinone ether sulfone ketone) (QAPPESK) was prepared from CMPPESK by quaternization. QAPPESK had excellent solvent resistance, which was only partly soluble in sulfuric acid (98%) and swollen in N,N-dimethylformamide (DMF). The vanadium redox flow battery (V-RFB) using QAPPESK anion-exchange membrane had better performance with 88.3% of overall energy efficiency.
基金Supported by the Scientific and Technological Development Programs of Beijing Municipal Education Commission, China (No.KM201010011004)the Scientific Research Foundation for the Returned Overseas Chinese Scholars, Ministry of Education, China, the 2011 Merit-based Research Funding for Picked Returned Overseas Scholars, Beijing Municipality, ChinaBeijing Technology and Business University Through a Research Project Approved for Undergraduates
文摘Photo-grafting of hydrophilic monomer was used to enhance the hydrophilicity of poly(ether ether ketone) (PEEK) with the aim of extending its applications to biological fields. PEEK sheets were surface modified by grafting of acrylamide(AAm) with ultraviolet(UV) irradiation in the presence or absence of benzophenone(BP). The effects of BP, irradiation time and monomer concentration on the surface wettability of PEEK were investigated. Characteriza tion of modified PEEK using scanning electron microscopy(SEM), energy-disperse spectrometer(EDS) and water contact angle measurements shows that AAm was successfully grafted on PEEK surface both in presence and absence of BP. With the increase in irradiation time and monomer concentration, contact angles decrease to as low as 30°, demonstrating a significant improvement of surface hydrophilicity. In agreement with the decrease in contact angle, under identical conditions, the nitrogen concentration increases, suggesting the increase in grafting degree of the grafting polymerization. This investigation demonstrates a self-initiation of PEEK due to its BP-like structure in the backbone of the polymer. Though the graft polymerization proceeds more readily in the presence of BP, the self-initiated graft polymerization is clearly observed.
基金support of this work from the Research Council of Mazandaran University
文摘A highly efficient green protocol for the preparation of bis-indolylmethanes,bis-2-methylindolylmethanes,bis-1-methylindolylmethanes and 3,3 -diindolyloxindole derivatives from the reaction of indoles with various aldehydes and ketones in the presence of cellulose sulfuric acid under solvent-free conditions is reported.The significant features of this procedure are high yields of the products,mild reaction,solvent-free condition and non-toxicity of the catalyst.
基金support by the Natural Science Foundation of Zhejiang Province(No.Y4051137,Y405015 and Y4080177)
文摘Michael addition of indole and pyrrole to a variety of α, β-unsaturated ketones was efficiently promoted by a catalytic amount of GaCl3 in aqueous media to afford the corresponding products in good to excellent yields.
基金Supported by the National Natural Science Foundation of China( No. 2 98710 14 ) and the Foundation of Doctor byL anzhou U niversit
文摘A novel La complex with methyl-2-pyridyl ketone benzoyl hydrazone has been synthesized and determined by single crystal X-ray diffraction. The crystal is monoclinic with space group C2/c, a =1 7081(3) nm, b =1 5660(3) nm, c =1 3512(3) nm, α=90 00°, β=94 39(1)°, γ=90 00°, V =3 6037(12) nm 3, Z =4 . The complex is a ten-coordinated one with a lanthanum ion surrounded by a N 4O 6 set. The crystal structure is stabilized by hydrogen bonds between water molecules and NO - 3 anions.
基金support and purchase of Hewlett-Packard 6890 GC-Hewlett-Packard 5973N MSD instrument.
文摘The efficient, green, facile, mild and straightforward conversion procedure for the oxidation of cyclic ketones to lactones at room temperature utilizing potassium peroxydisulfate (K2S2O8) in acidic media is satisfactory to high yields without using traditional chlorinated solvents is reported. This oxidative reagent is cheap and friendly environmental procedure for industrial purposes than use of organic peracids.
文摘Green,mild and efficient iodination of hydroxylated aromatic aldehydes and ketones using iodine and iodic acid in the solidstate by grinding under solvent-free conditions at room temperature.This method provides several advantages such as environmentally friendly,short reaction times,high yields,non-hazardous and simple work-up procedure.
文摘AIM: To identify plasma metabolites used as biomarkers in order to distinguish cirrhotics from controls and encephalopathics.METHODS: A clinical study involving stable cirrhotic patients with and without overt hepatic encephalopathy was designed. A control group of healthy volunteers was used. Plasma from those patients was analysed using 1H- nuclear magnetic resonance spectroscopy. We used the Carr Purcell Meiboom Gill sequence to process the sample spectra at ambient probe temperature. We used a gated secondary irradiation field for water signal suppression. Samples were calibrated and referenced using the sodium trimethyl silyl propionate peak at 0.00 ppm. For each sample 128 transients(FID's) were acquired into 32 K complex data points over a spectral width of 6 KHz. 30 degree pulses were applied with an acquisition time of 4.0 s in order to achieve better resolution, followed by a recovery delay of 12 s, to allow for complete relaxation and recovery of the magnetisation. A metabolic profile was created for stable cirrhotic patients without signs of overt hepatic encephalopathy and encephalopathic patients as well as healthy controls. Stepwise discriminant analysis was then used and discriminant factors were created to differentiate between the three groups.RESULTS: Eighteen stabled cirrhotic patients, eighteen patients with overt hepatic encephalopathy and seventeen healthy volunteers were recruited. Patients with cirrhosis had significantly impaired ketone body metabolism, urea synthesis and gluconeogenesis. This was demonstrated by higher concentrations of acetoacetate(0.23 ± 0.02 vs 0.05 ± 0.00, P < 0.01), and b-hydroxybutarate(0.58 ± 0.14 vs 0.08 ± 0.00, P < 0.01), lower concentrations of glutamine(0.44 ± 0.08 vs 0.63 ± 0.03, P < 0.05), histidine(0.16 ± 0.01 vs 0.36 ± 0.04, P < 0.01) and arginine(0.08 ± 0.01 vs 0.14 ± 0.02, P < 0.03) and higher concentrations of glutamate(1.36 ± 0.25 vs 0.58 ± 0.04, P < 0.01), lactate(1.53 ± 0.11 vs 0.42 ± 0.05, P < 0.01), pyruvate(0.11 ± 0.02 vs 0.03 ± 0.00, P < 0.01) threonine(0.39 ± 0.02 vs 0.08 ± 0.01, P < 0.01) and aspartate(0.37 ± 0.03 vs 0.03 ± 0.01). A five metabolite signature by stepwise discriminant analysis could separate between controls and cirrhotic patients with an accuracy of 98%. In patients with encephalopathy we observed further derangement of ketone body metabolism, impaired production of glycerol and myoinositol, reversal of Fischer's ratio and impaired glutamine production as demonstrated by lower b-hydroxybutyrate(0.58 ± 0.14 vs 0.16 ± 0.02, P < 0.0002), higher acetoacetate(0.23 ± 0.02 vs 0.41 ± 0.16, P < 0.05), leucine(0.33 ± 0.02 vs 0.49 ± 0.05, P < 0.005) and isoleucine(0.12 ± 0.02 vs 0.27 ± 0.02, P < 0.0004) and lower glutamine(0.44 ± 0.08 vs 0.36 ± 0.04, P < 0.013), glycerol(0.53 ± 0.03 vs 0.19 ± 0.02, P < 0.000) and myoinositol(0.36 ± 0.04 vs 0.18 ± 0.02, P < 0.010) concentrations. A four metabolite signature by stepwise discriminant analysis could separate between encephalopathic and cirrhotic patients with an accuracy of 87%.CONCLUSION: Patients with cirrhosis and patients with hepatic encephalopathy exhibit distinct metabolic abnormalities and the use of metabonomics can select biomarkers for these diseases.