Glycerol is a by-product of biodiesel production and is an important readily available platform chemical.Valorization of glycerol into value-added chemicals has gained immense attention.Herein,we carried out the conve...Glycerol is a by-product of biodiesel production and is an important readily available platform chemical.Valorization of glycerol into value-added chemicals has gained immense attention.Herein,we carried out the conversion of glycerol to formic acid and glycolic acid using H2O2 as an oxidant and metal(Ⅲ)triflate-based catalytic systems.Aluminum(Ⅲ)triflate was found to be the most efficient catalyst for the selective oxidation of glycerol to formic acid.A correlation between the catalytic activity of the metal cations and their hydrolysis constants(Kh)and water exchange rate constants was observed.At 70 ℃,a formic acid yield of up to 72% could be attained within 12 h.The catalyst could be recycled at least five times with a high conversion rate,and hence can also be used for the selective oxidation of other biomass platform molecules.Reaction kinetics and 1H NMR studies showed that the oxidation of glycerol(to formic acid)involved glycerol hydrolysis pathways with glyceric acid and glycolic acid as the main intermediate products.Both the [Al(OH)x]^n+ Lewis acid species and CF3SO3H Brosted acid,which were generated by the in-situ hydrolysis of Al(OTf)3,were responsible for glycerol conversion.The easy availability,high efficiency,and good recyclability of Al(OTf)3 render it suitable for the selective oxidation of glycerol to high value-added products.展开更多
2,3-Dihydro-2-aryl-4（1H）-quinazolinones were prepared in good yields via condensation of o-aminobenzamide with aldehydes promoted by a catalytic amount of Sc（OTf）3 under mild conditions.
AIM: To show that aluminum potassium sulfate and tannic acid(ALTA) sclerotherapy has a high success rate for Grade Ⅱ and Ⅲ hemorrhoids.METHODS: This study was based on the clinical data of 604 patients with hemorrho...AIM: To show that aluminum potassium sulfate and tannic acid(ALTA) sclerotherapy has a high success rate for Grade Ⅱ and Ⅲ hemorrhoids.METHODS: This study was based on the clinical data of 604 patients with hemorrhoids who underwent ALTA sclerotherapy between January 2009 and February 2015. The objective of this study was to assess the efficacy of this treatment for Grades Ⅱ and Ⅲ hemorrhoids. Preoperative and postoperative symptoms, complications and success rate were all assessed retrospectively. Follow-up consisted of a simple questionnaire, physical examination and an anoscopy. Patients were followed-up at one day, one week, two weeks, one month, one year, two years, three years, four years and five years after the ALTA sclerotherapy.RESULTS: One hundred and sixty-nine patients were diagnosed with Grade Ⅱ hemorrhoids and 435 patients were diagnosed with Grade Ⅲ hemorrhoids. The one year, three year and five year cumulative success rates of ALTA sclerotherapy for Grades Ⅱ and Ⅲ hemo-rrhoids were 95.9% and 93.1%; 89.3% and 83.7%; and 89.3% and 78.2%, respectively. No significant differences were observed in the cumulative success rates after ALTA sclerotherapy between Grades Ⅱ and Ⅲ hemorrhoids(P = 0.09). There were forty-seven post-operative complications(low grade fever; anal pain; urinary retention; rectal ulcer; and others). No serious or life-threatening complications occurred and all cases improved through conservative treatment. At univariate analysis there were no predictive factors of failure.CONCLUSION: ALTA sclerotherapy has had a high success rate for Grade Ⅱ and Ⅲ hemorrhoids during five years of post-operative treatment. However, additional studies are needed to evaluate the efficacy of this ALTA sclerotherapy in the management of hemorrhoidal disease.展开更多
An efficient and simple method for the preparation of 5-arylamino-1H-tetrazole and 1-aryl-5-amino-1H-tetrazole derivatives is reported using aluminum（Ⅲ） hydrogensulfate（Al（HSO4）3） as an effective heterogeneous ...An efficient and simple method for the preparation of 5-arylamino-1H-tetrazole and 1-aryl-5-amino-1H-tetrazole derivatives is reported using aluminum（Ⅲ） hydrogensulfate（Al（HSO4）3） as an effective heterogeneous catalyst from secondary arylcyanamides. Generally,when the substitution in arylcyanamide is strongly electron-withdrawing the position of equilibrium would shift toward the isomer of 1-aryl-5-amino-1H-tetrazole（B） and as the electron-donating of substituent increased,the position of equilibrium is shifted toward the isomer of 5-arylamino-1H-tetrazole（A）.The present methodology offers several advantages,such as excellent yields,short reaction times,easy work-up and greener conditions.展开更多
Catalyzed by ytterbium（III） triflate hydrate [Yb（OTf）3.xH20], the Michael addition and cyclocondensation of α,β-unsaturated ketones with active methylene compounds to afford the 1,4-adducts and benzo[b]pyran der...Catalyzed by ytterbium（III） triflate hydrate [Yb（OTf）3.xH20], the Michael addition and cyclocondensation of α,β-unsaturated ketones with active methylene compounds to afford the 1,4-adducts and benzo[b]pyran derivatives, respectively were studied.展开更多
An AI^3＋ sensor based on the membrane of acetyl cellulose containing nano γ-Al2O3 crystals was studied. In the buffer solution of 0.5 mol/L CH3COOH-CH3COONa （pH=5.0）, the sensor responds to AI^3＋ in a linear rang...An AI^3＋ sensor based on the membrane of acetyl cellulose containing nano γ-Al2O3 crystals was studied. In the buffer solution of 0.5 mol/L CH3COOH-CH3COONa （pH=5.0）, the sensor responds to AI^3＋ in a linear range from 1.00×10^-5 to 1.00x10-^2 mol/L. A near-Nernstian response was obtained and the regression equation was E （mv） = -161.4-26.54 Ig [AI^3＋] with a detection limit of 7.90x10^-6 mol/L. More than 14 different ions as the considered interferences were tested and the relevant selectivity coefficients were determined using the separate solution method （SSM）. The sensor possesses many advantages including short conditioning time, fast response, and, especially, very good selectivity over a wide variety of other co-existing ions. The sample analysis on the aluminium migration amount from aluminium utensils to the solution was determined by this sensor. The analytical results were agreed with that of inductively coupled plasma-atomic emission spectroscopy（ICP-RES）.展开更多
基金the National Natural Science Foundation of China(21773061,21373082)the Innovation Program of Shanghai Municipal Education Commission(15ZZ031)~~
文摘Glycerol is a by-product of biodiesel production and is an important readily available platform chemical.Valorization of glycerol into value-added chemicals has gained immense attention.Herein,we carried out the conversion of glycerol to formic acid and glycolic acid using H2O2 as an oxidant and metal(Ⅲ)triflate-based catalytic systems.Aluminum(Ⅲ)triflate was found to be the most efficient catalyst for the selective oxidation of glycerol to formic acid.A correlation between the catalytic activity of the metal cations and their hydrolysis constants(Kh)and water exchange rate constants was observed.At 70 ℃,a formic acid yield of up to 72% could be attained within 12 h.The catalyst could be recycled at least five times with a high conversion rate,and hence can also be used for the selective oxidation of other biomass platform molecules.Reaction kinetics and 1H NMR studies showed that the oxidation of glycerol(to formic acid)involved glycerol hydrolysis pathways with glyceric acid and glycolic acid as the main intermediate products.Both the [Al(OH)x]^n+ Lewis acid species and CF3SO3H Brosted acid,which were generated by the in-situ hydrolysis of Al(OTf)3,were responsible for glycerol conversion.The easy availability,high efficiency,and good recyclability of Al(OTf)3 render it suitable for the selective oxidation of glycerol to high value-added products.
基金We are grateful to the National Basic Research Program （No. 2003CB114402）；the National Natural Science Foundation of China （Nos. 20476098 and 20676123） ；Wenzhou University Post-graduate Innovation Foundation （No. YCX0515） for financial support.
文摘2,3-Dihydro-2-aryl-4（1H）-quinazolinones were prepared in good yields via condensation of o-aminobenzamide with aldehydes promoted by a catalytic amount of Sc（OTf）3 under mild conditions.
文摘AIM: To show that aluminum potassium sulfate and tannic acid(ALTA) sclerotherapy has a high success rate for Grade Ⅱ and Ⅲ hemorrhoids.METHODS: This study was based on the clinical data of 604 patients with hemorrhoids who underwent ALTA sclerotherapy between January 2009 and February 2015. The objective of this study was to assess the efficacy of this treatment for Grades Ⅱ and Ⅲ hemorrhoids. Preoperative and postoperative symptoms, complications and success rate were all assessed retrospectively. Follow-up consisted of a simple questionnaire, physical examination and an anoscopy. Patients were followed-up at one day, one week, two weeks, one month, one year, two years, three years, four years and five years after the ALTA sclerotherapy.RESULTS: One hundred and sixty-nine patients were diagnosed with Grade Ⅱ hemorrhoids and 435 patients were diagnosed with Grade Ⅲ hemorrhoids. The one year, three year and five year cumulative success rates of ALTA sclerotherapy for Grades Ⅱ and Ⅲ hemo-rrhoids were 95.9% and 93.1%; 89.3% and 83.7%; and 89.3% and 78.2%, respectively. No significant differences were observed in the cumulative success rates after ALTA sclerotherapy between Grades Ⅱ and Ⅲ hemorrhoids(P = 0.09). There were forty-seven post-operative complications(low grade fever; anal pain; urinary retention; rectal ulcer; and others). No serious or life-threatening complications occurred and all cases improved through conservative treatment. At univariate analysis there were no predictive factors of failure.CONCLUSION: ALTA sclerotherapy has had a high success rate for Grade Ⅱ and Ⅲ hemorrhoids during five years of post-operative treatment. However, additional studies are needed to evaluate the efficacy of this ALTA sclerotherapy in the management of hemorrhoidal disease.
文摘An efficient and simple method for the preparation of 5-arylamino-1H-tetrazole and 1-aryl-5-amino-1H-tetrazole derivatives is reported using aluminum（Ⅲ） hydrogensulfate（Al（HSO4）3） as an effective heterogeneous catalyst from secondary arylcyanamides. Generally,when the substitution in arylcyanamide is strongly electron-withdrawing the position of equilibrium would shift toward the isomer of 1-aryl-5-amino-1H-tetrazole（B） and as the electron-donating of substituent increased,the position of equilibrium is shifted toward the isomer of 5-arylamino-1H-tetrazole（A）.The present methodology offers several advantages,such as excellent yields,short reaction times,easy work-up and greener conditions.
基金the National Natural Science Foundation of China (No.20676123) for financial support.
文摘Catalyzed by ytterbium（III） triflate hydrate [Yb（OTf）3.xH20], the Michael addition and cyclocondensation of α,β-unsaturated ketones with active methylene compounds to afford the 1,4-adducts and benzo[b]pyran derivatives, respectively were studied.
基金This work was supported by the National Natural Science Foundation of China （No. 20577017）.
文摘An AI^3＋ sensor based on the membrane of acetyl cellulose containing nano γ-Al2O3 crystals was studied. In the buffer solution of 0.5 mol/L CH3COOH-CH3COONa （pH=5.0）, the sensor responds to AI^3＋ in a linear range from 1.00×10^-5 to 1.00x10-^2 mol/L. A near-Nernstian response was obtained and the regression equation was E （mv） = -161.4-26.54 Ig [AI^3＋] with a detection limit of 7.90x10^-6 mol/L. More than 14 different ions as the considered interferences were tested and the relevant selectivity coefficients were determined using the separate solution method （SSM）. The sensor possesses many advantages including short conditioning time, fast response, and, especially, very good selectivity over a wide variety of other co-existing ions. The sample analysis on the aluminium migration amount from aluminium utensils to the solution was determined by this sensor. The analytical results were agreed with that of inductively coupled plasma-atomic emission spectroscopy（ICP-RES）.
