Objective： This study investigated the effects of aqueous leaf extract of Tridax procumbens （ALETP） on con- tractile activity of corpus cavernosum in N-nitro-L-arginine methyl ester （L-NAME）-induced hypertensive ...Objective： This study investigated the effects of aqueous leaf extract of Tridax procumbens （ALETP） on con- tractile activity of corpus cavernosum in N-nitro-L-arginine methyl ester （L-NAME）-induced hypertensive male rats. Methods： Twenty normal, adult male rats （130-150 g） were divided into four groups of five rats each. Group I （control） was given normal saline （0.6 mL/kg） and group II was given L-NAME （40 mg/kg） for 6 weeks. Groups Ill and IV also received L-NAME （40 mg/kg） for 6 weeks but were further co-treated with 100 and 200 mg/kg of ALETP, respectively, from week 4 to week 6. All treatments were given orally. Strips of corpus cavernosum from each of the four groups were exposed to increasing concentrations of acetyl~ choline （ACh） and sodium nitroprusside （SNP） （10^-9-10^-5 tool/L） after contraction with phenylephrine （10^-7 mol/L） to test for a dose-response effect, Response to potassium and calcium was also measured after cumulatively adding potassium and calcium （10-50 mmol/L） to potassium- and calcium-free organ chamber. Isometric contractions were recorded through an Ugo Basile data capsule acquisition system. Results： Mean arterial blood pressure was significantly reduced in the ALETP co-treated group compared to the control and L-NAME-only groups （P 〈 0.05）. Cavernosa strips from ALETP co-treated rats exhibited significant inhibition of contraction in response to phenylephrine, potassium chloride, and calcium chlo- ride （P 〈 0.05）. Relaxation in response to Ach and SNP was also significantly impaired in cavernosa strips from the L-NAME-only treated group （P 〈 0.05）, while ALETP co-treated groups showed enhanced per- centage relaxation. Conclusion： ALETP treatment of L-NAME-induced hypertensive rats promotes a relaxant effect on isolated cavernosa strips. ALETP shows potential in correcting erectile dysfunction in hypertension.展开更多
The thermal behavior and kinetic parameters of the exothermic decomposition reaction of N -methyl- N -nitro-2,2,2-trinit^roe^tha^na^mine in a temperature-programmed mode have been investigated by means of differential...The thermal behavior and kinetic parameters of the exothermic decomposition reaction of N -methyl- N -nitro-2,2,2-trinit^roe^tha^na^mine in a temperature-programmed mode have been investigated by means of differential scanning calorimetry (DSC). The kinetic equation of the exothermic decomposition process of the compound is proposed. The values of the apparent activation energy ( E _a),pre-exponential factor ( A ),entropy of activation (Δ S ≠),enthalpy of activation (Δ H ≠),and free energy of activation (Δ G ≠) of this reaction and the critical temperature of thermal explosion of the compound are reported. Information is obtained on the mechanism of the initial stage of the thermal decomposition of the compound.展开更多
The thermal behavior and kinetic parameters of the exothermic decomposition reaction of N,N-bis[N-(2,2,2-tri-nitroethyl)-N-nitro]ethylenediamine in a temperature-programmed mode have been investigated by means of diff...The thermal behavior and kinetic parameters of the exothermic decomposition reaction of N,N-bis[N-(2,2,2-tri-nitroethyl)-N-nitro]ethylenediamine in a temperature-programmed mode have been investigated by means of differential scanning calorimetry (DSC). The results show that kinetic model function in differential form, apparent activation energy Ea and pre-exponential factor A of this reaction are 3(1-a)2/3, 203.67 kJmol-1 and 1020.61 s-1, respectively. The critical temperature of thermal explosion of the compound is 182.2 ℃. The values of DS, DH and DG of this reaction are 143.3 Jmol-1K-1, 199.5 kJmol-1 and 135.5 kJmol-1, respectively.展开更多
In order to investigate and compare the effects of Tetradium ruticarpum and Glycyrrhizae extracts in terms of scavenging sodium nitrite and inhibiting N-ni- troso compounds formation, the 1_9（3^3） orthogonal test wa...In order to investigate and compare the effects of Tetradium ruticarpum and Glycyrrhizae extracts in terms of scavenging sodium nitrite and inhibiting N-ni- troso compounds formation, the 1_9（3^3） orthogonal test was conducted to extract the active components. In addition, the capacities of scavenging sodium nitrite and of in- hibiting the N-nitroso compounds formation were measured to confirm the optimum condition of extracting. When the scavenging rate was considered as the main index, the maximum capacities of scavenging sodium nitrite by the extracts of Tetradi- urn ruticarpum and Glycyrrhizae were 0.836 5 and 0.558 0, respectively. Further- more, when the disconnection rate was considered as the main index, the maximum capacities of inhibiting the N-nitroso compounds formation by the extracts of Tetradi- urn ruticarpum and G/ycyrrhizae were 0.922 8 and 0.625 6, respectively. As a re- suit, the capacity of inhibiting nitrosation reaction by Tetradium ruticarpum was shown to be much stronger than G/ycyrrhizae, no matter the scavenging rate or the disconnection rate as the main index to be considered.展开更多
文摘Objective： This study investigated the effects of aqueous leaf extract of Tridax procumbens （ALETP） on con- tractile activity of corpus cavernosum in N-nitro-L-arginine methyl ester （L-NAME）-induced hypertensive male rats. Methods： Twenty normal, adult male rats （130-150 g） were divided into four groups of five rats each. Group I （control） was given normal saline （0.6 mL/kg） and group II was given L-NAME （40 mg/kg） for 6 weeks. Groups Ill and IV also received L-NAME （40 mg/kg） for 6 weeks but were further co-treated with 100 and 200 mg/kg of ALETP, respectively, from week 4 to week 6. All treatments were given orally. Strips of corpus cavernosum from each of the four groups were exposed to increasing concentrations of acetyl~ choline （ACh） and sodium nitroprusside （SNP） （10^-9-10^-5 tool/L） after contraction with phenylephrine （10^-7 mol/L） to test for a dose-response effect, Response to potassium and calcium was also measured after cumulatively adding potassium and calcium （10-50 mmol/L） to potassium- and calcium-free organ chamber. Isometric contractions were recorded through an Ugo Basile data capsule acquisition system. Results： Mean arterial blood pressure was significantly reduced in the ALETP co-treated group compared to the control and L-NAME-only groups （P 〈 0.05）. Cavernosa strips from ALETP co-treated rats exhibited significant inhibition of contraction in response to phenylephrine, potassium chloride, and calcium chlo- ride （P 〈 0.05）. Relaxation in response to Ach and SNP was also significantly impaired in cavernosa strips from the L-NAME-only treated group （P 〈 0.05）, while ALETP co-treated groups showed enhanced per- centage relaxation. Conclusion： ALETP treatment of L-NAME-induced hypertensive rats promotes a relaxant effect on isolated cavernosa strips. ALETP shows potential in correcting erectile dysfunction in hypertension.
基金ProjectsupportedbytheScienceandTechnologyFoundationofShaanxiKeyLaboratoryofPhysico InorganicChemistry (No .2 9 3 ,2 0 0 1)andtheScienceandTechnologyFoundationoftheNationalDefenceKeyLaboratoryofPropellantandExplosiveCombustionofChina (No .5 14 5 5 0 10 1)
文摘The thermal behavior and kinetic parameters of the exothermic decomposition reaction of N -methyl- N -nitro-2,2,2-trinit^roe^tha^na^mine in a temperature-programmed mode have been investigated by means of differential scanning calorimetry (DSC). The kinetic equation of the exothermic decomposition process of the compound is proposed. The values of the apparent activation energy ( E _a),pre-exponential factor ( A ),entropy of activation (Δ S ≠),enthalpy of activation (Δ H ≠),and free energy of activation (Δ G ≠) of this reaction and the critical temperature of thermal explosion of the compound are reported. Information is obtained on the mechanism of the initial stage of the thermal decomposition of the compound.
基金Project supported by the Science and Technology Foundation of Shaanxi Key Laboratory of Physico-Inorganic Chemistry (No. 29-3 2001) and the Science and Technology Foundation of the National Defence Key Laboratory of Propellant and Explosive Combustion
文摘The thermal behavior and kinetic parameters of the exothermic decomposition reaction of N,N-bis[N-(2,2,2-tri-nitroethyl)-N-nitro]ethylenediamine in a temperature-programmed mode have been investigated by means of differential scanning calorimetry (DSC). The results show that kinetic model function in differential form, apparent activation energy Ea and pre-exponential factor A of this reaction are 3(1-a)2/3, 203.67 kJmol-1 and 1020.61 s-1, respectively. The critical temperature of thermal explosion of the compound is 182.2 ℃. The values of DS, DH and DG of this reaction are 143.3 Jmol-1K-1, 199.5 kJmol-1 and 135.5 kJmol-1, respectively.
基金Supported by National Natural Science Foundation of China(31372159)Scientific Research Foundation for The Junior Teachers in Beijing Normal University,Zhuhai(201353015)Innovative Foundation Project of Beijing Normal University,Zhuhai(1317713016)~~
文摘In order to investigate and compare the effects of Tetradium ruticarpum and Glycyrrhizae extracts in terms of scavenging sodium nitrite and inhibiting N-ni- troso compounds formation, the 1_9（3^3） orthogonal test was conducted to extract the active components. In addition, the capacities of scavenging sodium nitrite and of in- hibiting the N-nitroso compounds formation were measured to confirm the optimum condition of extracting. When the scavenging rate was considered as the main index, the maximum capacities of scavenging sodium nitrite by the extracts of Tetradi- urn ruticarpum and Glycyrrhizae were 0.836 5 and 0.558 0, respectively. Further- more, when the disconnection rate was considered as the main index, the maximum capacities of inhibiting the N-nitroso compounds formation by the extracts of Tetradi- urn ruticarpum and G/ycyrrhizae were 0.922 8 and 0.625 6, respectively. As a re- suit, the capacity of inhibiting nitrosation reaction by Tetradium ruticarpum was shown to be much stronger than G/ycyrrhizae, no matter the scavenging rate or the disconnection rate as the main index to be considered.
