The total synthesis of 3,7 dimethyl 2 tridecanyl acetate,the active component of the sex pheromone of diprion pini,was investigated in this paper.The two key synthins blocks,2 methyl octan 1 yl lithium and 3,4 ...The total synthesis of 3,7 dimethyl 2 tridecanyl acetate,the active component of the sex pheromone of diprion pini,was investigated in this paper.The two key synthins blocks,2 methyl octan 1 yl lithium and 3,4 dimethyl γ butyrolactone,were obtained from diethyl malonate and 2,3 epoxybutane.2 Methyl octan 1 yl lithium reacted with 3,4 dimethyl γ butyrolactone to yield the ketoalcohol and then followed by Huang Minlong reduction to afford 3,7 dimethyl 2 tridecanol,acylated with acetic anhydide to give 3,7 dimethyl 2 tridecanyl acetate.展开更多
Two metabolites （A and B） were isolated from the mycelium of mangrove endophytic fungus Stysanus like sp. （#2492） from the South China Sea. Their structures were identified by spectral data as N-（2-hydroxytetraco...Two metabolites （A and B） were isolated from the mycelium of mangrove endophytic fungus Stysanus like sp. （#2492） from the South China Sea. Their structures were identified by spectral data as N-（2-hydroxytetracosyl）-2-amino-1,3,4-trihydroxyoctadecane （A） and γ -stearolactone （B）. It is the first report that γ -stearolactone （B） is isolated from marine fungus as natural product.展开更多
Flotation experiments were performed to investigate the separation of muscovite and quartz in the presence of dodecylamine(DDA), tallow amine(TTA) and dodecyltrimethylammonium bromide(DTAC). The adsorption mechanisms ...Flotation experiments were performed to investigate the separation of muscovite and quartz in the presence of dodecylamine(DDA), tallow amine(TTA) and dodecyltrimethylammonium bromide(DTAC). The adsorption mechanisms of these three kinds of amines on muscovite and quartz were studied by FT-IR spectrum analysis, contact angle measurement and molecular dynamics(MD) simulation. The results reveal that the separation of muscovite from quartz is feasible at strong acid pulp condition using amine collectors. TTA and DTAC show poorer collecting ability for flotation of the two minerals compared with DDA. Physical adsorption is found to be the main adsorption module of amine collectors on muscovite and quartz by FT-IR analysis. MD simulation results show a strong physical adsorption ability of DDA+ cation on muscovite and quartz(muscovite(001):-117.31 kJ/mol, quartz(100):-89.43 kJ/mol), while neutral DDA molecular can hardly absorb onto the surface of these two minerals. These findings provide a novel explanation for the flotation mechanism from the perspective of MD simulation.展开更多
An ion-pair compound, [HL]2[Ni(CN)4]4H2O 1 has been obtained as an unexpected product when we attempt to prepare a heterometallic cyano-bridged complex by the reaction of GdCl3nH2O, K2Ni(CN)4 and L (L=4-(2-hydroxyphen...An ion-pair compound, [HL]2[Ni(CN)4]4H2O 1 has been obtained as an unexpected product when we attempt to prepare a heterometallic cyano-bridged complex by the reaction of GdCl3nH2O, K2Ni(CN)4 and L (L=4-(2-hydroxyphenyl)-1,5,9-triazacyclododecan-2-one) in aqueous solution, and characterized by single-crystal X-ray diffraction. It crystallizes in monoclinic, space group P21/n with a = 12.380(1), b = 9.9637(8), c = 17.087(1) ? ?= 105.947(2)? V = 2026.6(3) ?, Rint = 0.0509, Z = 2, Dc = 1.297 g/cm3, C34H56O8N10Ni, Mr = 791.60, F(000) = 844, m(MoKa) = 0.538 mm1, S = 1.030, the final R = 0.0644 and wR = 0.1299 for 2023 observed reflections with I ≥ 2(I). The title compound 1 contains one anion of [Ni(CN)4]2, two cations of [HL]+ and four packing water molecules, which are held together by the NH···O and OH···O hydrogen bonds to form a three- dimensional framework.展开更多
AIM:To assess and compare the efficacy and safety of two triple regimes:A)metronidazole,amoxicillin and omeprazole, which is still widely used in Russia,and B)azithromycin, amoxicillin and omeprazole in healing active...AIM:To assess and compare the efficacy and safety of two triple regimes:A)metronidazole,amoxicillin and omeprazole, which is still widely used in Russia,and B)azithromycin, amoxicillin and omeprazole in healing active duodenal ulcer and H.pylori eradication. METHODS:100 patients with active duodenal ulcer were included in the open,multicentre,randomized study with comparative groups.Patients were randomly assigned to one of the following one-week triple regimes:A) metronidazole 500 mg bid,amoxicillin I g bid and omeprazole 20 mg bid(OAM,n=50)and B)azithromycin 1 god for the first 3 days(total dose 3 g),amoxicillin 1 g bid and omeprazole 20 mg bid(OAA,n=50).Omeprazole 20 mg od was given after the eradication course as a monotherapy for three weeks.The control endoscopy was performed 8 weeks after the entry.H.pyloriinfection was determined in the entry of the study and four weeks after the cessation of treatment by means of histology and CLO-test. RESULTS:97 patients completed the study according to the protocol(1 patient of the OAM group did not come to the control endoscopy,2 patients of the OAA group stopped the treatment because of mild allergic urticaria).Duodenal ulcers were healed in 48 patients of the OAM group(96 %, C190.5-100 %)and in 46 patients of the OAA group(92 %, CI 89.5-94.5 %)(p=ns).H.pyloHinfection was eradicated in 15 out of 50 patients with OAM(30 %,CI 17-43 %)and in 36 out of 50 patients treated with OAA(72 %;CI 59-85 %) (P<0.001)-ITT analysis.CONCLUSION: The triple therapy with omeprazole, amoxicillin and metronidazole failed to eradicate H.pylori'vc\ the majority of patients, which is an essential argument to withdraw this regimen out of the national recommendations. Macrolide with amoxicillin are preferable to achieve higher eradication rates. Azithromycin (1 g od for the first 3 days) can be considered as a successful component of the triple PPI-based regimen.展开更多
A kinetic model fitted by the empirical equation has been proposed to describe the liquid drainage behavior. Rate constants （kd） of liquid drainage equation could be obtained from the above empirical equation. In th...A kinetic model fitted by the empirical equation has been proposed to describe the liquid drainage behavior. Rate constants （kd） of liquid drainage equation could be obtained from the above empirical equation. In this paper, the stability of the colloidal gas aphrons （CGAs）, the effect of concentrations of sodium dodecyl benzene sulphate （SDBS）, dodecyl trimethylammonium bromide （HTAB） and polyoxyethylene sorbitol anhydride monolaurate（Tween-20）, temperature, stirring speed, stirring time, and various kinds of salts on the kd of liquid drainage are further investigated. The results show that the Arrhenius equation can be successfully used to describe the relation between kd arid absolute temperature （T）, and concentrations of surfactants, stirring speed, stirring time and salinities also have great effect on the kd. At last, the CGAs drainage mechanism is explained from analysis of the rate of liquid drainage as a function of time.展开更多
An efficient and environmentally friendly procedure for the one-pot synthesis of 13-acetyl-9-methyl-ll-oxo-8-oxa-10,12-diazatricyclo[7.3.1.0^2,7]trideca-2,4,6-triene from salicylaldehyde, acetylacetone and urea via Bi...An efficient and environmentally friendly procedure for the one-pot synthesis of 13-acetyl-9-methyl-ll-oxo-8-oxa-10,12-diazatricyclo[7.3.1.0^2,7]trideca-2,4,6-triene from salicylaldehyde, acetylacetone and urea via Biginelli condensation and intramolecular Michael-addition by using magnesium bromide as an inexpensive and easily available catalyst in a solvent-free condition is described. The structural elucidation of the product is reported by ^1H- and ^13C NMR spectra. The product can also be identified by its EI TOF mass spectrometry based on the molecular ion at m/s 246（10%） and on the fragment ions in which two nitrogen atoms are remained. Three kinds of characteristic fragmentation pathways from the molecular ion were observed. One is the loss of the OH radical to form the dihydropyrimidinone cation at m/z 229（48%）, followed by elimination of a molecular methane forming the pyrimidinone cation at m/z 213（27%）. The second is the cleavage of the C6H4OH radical, and the formation of the dihydropyrimidinone cation at m/z 153（24%）. The third one is the loss of MeC-O radical to afford the oxygen-bridged fragment ion at m/z 203（33%）.展开更多
基金Supported by Foundation for University Key Teacher by the Min-istry of Education
文摘The total synthesis of 3,7 dimethyl 2 tridecanyl acetate,the active component of the sex pheromone of diprion pini,was investigated in this paper.The two key synthins blocks,2 methyl octan 1 yl lithium and 3,4 dimethyl γ butyrolactone,were obtained from diethyl malonate and 2,3 epoxybutane.2 Methyl octan 1 yl lithium reacted with 3,4 dimethyl γ butyrolactone to yield the ketoalcohol and then followed by Huang Minlong reduction to afford 3,7 dimethyl 2 tridecanol,acylated with acetic anhydide to give 3,7 dimethyl 2 tridecanyl acetate.
文摘Two metabolites （A and B） were isolated from the mycelium of mangrove endophytic fungus Stysanus like sp. （#2492） from the South China Sea. Their structures were identified by spectral data as N-（2-hydroxytetracosyl）-2-amino-1,3,4-trihydroxyoctadecane （A） and γ -stearolactone （B）. It is the first report that γ -stearolactone （B） is isolated from marine fungus as natural product.
基金Project(52012BAB07B0)supported by National "Twelfth Five-Year" Plan for Science&Technology Support,ChinaProject(2013zzts066)supported by the Graduate Student Self-innovation Program from Central South University,China
文摘Flotation experiments were performed to investigate the separation of muscovite and quartz in the presence of dodecylamine(DDA), tallow amine(TTA) and dodecyltrimethylammonium bromide(DTAC). The adsorption mechanisms of these three kinds of amines on muscovite and quartz were studied by FT-IR spectrum analysis, contact angle measurement and molecular dynamics(MD) simulation. The results reveal that the separation of muscovite from quartz is feasible at strong acid pulp condition using amine collectors. TTA and DTAC show poorer collecting ability for flotation of the two minerals compared with DDA. Physical adsorption is found to be the main adsorption module of amine collectors on muscovite and quartz by FT-IR analysis. MD simulation results show a strong physical adsorption ability of DDA+ cation on muscovite and quartz(muscovite(001):-117.31 kJ/mol, quartz(100):-89.43 kJ/mol), while neutral DDA molecular can hardly absorb onto the surface of these two minerals. These findings provide a novel explanation for the flotation mechanism from the perspective of MD simulation.
文摘An ion-pair compound, [HL]2[Ni(CN)4]4H2O 1 has been obtained as an unexpected product when we attempt to prepare a heterometallic cyano-bridged complex by the reaction of GdCl3nH2O, K2Ni(CN)4 and L (L=4-(2-hydroxyphenyl)-1,5,9-triazacyclododecan-2-one) in aqueous solution, and characterized by single-crystal X-ray diffraction. It crystallizes in monoclinic, space group P21/n with a = 12.380(1), b = 9.9637(8), c = 17.087(1) ? ?= 105.947(2)? V = 2026.6(3) ?, Rint = 0.0509, Z = 2, Dc = 1.297 g/cm3, C34H56O8N10Ni, Mr = 791.60, F(000) = 844, m(MoKa) = 0.538 mm1, S = 1.030, the final R = 0.0644 and wR = 0.1299 for 2023 observed reflections with I ≥ 2(I). The title compound 1 contains one anion of [Ni(CN)4]2, two cations of [HL]+ and four packing water molecules, which are held together by the NH···O and OH···O hydrogen bonds to form a three- dimensional framework.
文摘AIM:To assess and compare the efficacy and safety of two triple regimes:A)metronidazole,amoxicillin and omeprazole, which is still widely used in Russia,and B)azithromycin, amoxicillin and omeprazole in healing active duodenal ulcer and H.pylori eradication. METHODS:100 patients with active duodenal ulcer were included in the open,multicentre,randomized study with comparative groups.Patients were randomly assigned to one of the following one-week triple regimes:A) metronidazole 500 mg bid,amoxicillin I g bid and omeprazole 20 mg bid(OAM,n=50)and B)azithromycin 1 god for the first 3 days(total dose 3 g),amoxicillin 1 g bid and omeprazole 20 mg bid(OAA,n=50).Omeprazole 20 mg od was given after the eradication course as a monotherapy for three weeks.The control endoscopy was performed 8 weeks after the entry.H.pyloriinfection was determined in the entry of the study and four weeks after the cessation of treatment by means of histology and CLO-test. RESULTS:97 patients completed the study according to the protocol(1 patient of the OAM group did not come to the control endoscopy,2 patients of the OAA group stopped the treatment because of mild allergic urticaria).Duodenal ulcers were healed in 48 patients of the OAM group(96 %, C190.5-100 %)and in 46 patients of the OAA group(92 %, CI 89.5-94.5 %)(p=ns).H.pyloHinfection was eradicated in 15 out of 50 patients with OAM(30 %,CI 17-43 %)and in 36 out of 50 patients treated with OAA(72 %;CI 59-85 %) (P<0.001)-ITT analysis.CONCLUSION: The triple therapy with omeprazole, amoxicillin and metronidazole failed to eradicate H.pylori'vc\ the majority of patients, which is an essential argument to withdraw this regimen out of the national recommendations. Macrolide with amoxicillin are preferable to achieve higher eradication rates. Azithromycin (1 g od for the first 3 days) can be considered as a successful component of the triple PPI-based regimen.
基金Supported by the Eleventh Five Year National Key Technology R&D Program (2008BAE58B01)New Century Excellent Talents of Ministry of Education (NCET-07-0577),the People’s Republic of China
文摘A kinetic model fitted by the empirical equation has been proposed to describe the liquid drainage behavior. Rate constants （kd） of liquid drainage equation could be obtained from the above empirical equation. In this paper, the stability of the colloidal gas aphrons （CGAs）, the effect of concentrations of sodium dodecyl benzene sulphate （SDBS）, dodecyl trimethylammonium bromide （HTAB） and polyoxyethylene sorbitol anhydride monolaurate（Tween-20）, temperature, stirring speed, stirring time, and various kinds of salts on the kd of liquid drainage are further investigated. The results show that the Arrhenius equation can be successfully used to describe the relation between kd arid absolute temperature （T）, and concentrations of surfactants, stirring speed, stirring time and salinities also have great effect on the kd. At last, the CGAs drainage mechanism is explained from analysis of the rate of liquid drainage as a function of time.
基金This work was supported by the Natural Science Foundation of China （No.20425309）.
文摘An efficient and environmentally friendly procedure for the one-pot synthesis of 13-acetyl-9-methyl-ll-oxo-8-oxa-10,12-diazatricyclo[7.3.1.0^2,7]trideca-2,4,6-triene from salicylaldehyde, acetylacetone and urea via Biginelli condensation and intramolecular Michael-addition by using magnesium bromide as an inexpensive and easily available catalyst in a solvent-free condition is described. The structural elucidation of the product is reported by ^1H- and ^13C NMR spectra. The product can also be identified by its EI TOF mass spectrometry based on the molecular ion at m/s 246（10%） and on the fragment ions in which two nitrogen atoms are remained. Three kinds of characteristic fragmentation pathways from the molecular ion were observed. One is the loss of the OH radical to form the dihydropyrimidinone cation at m/z 229（48%）, followed by elimination of a molecular methane forming the pyrimidinone cation at m/z 213（27%）. The second is the cleavage of the C6H4OH radical, and the formation of the dihydropyrimidinone cation at m/z 153（24%）. The third one is the loss of MeC-O radical to afford the oxygen-bridged fragment ion at m/z 203（33%）.
