The heart is regulated by excitation-contraction mechanism and electrical stimulation, so both cardiac tissues and myocytes in vivo are affected by the mechanical and electrical factors at the same time. The device th...The heart is regulated by excitation-contraction mechanism and electrical stimulation, so both cardiac tissues and myocytes in vivo are affected by the mechanical and electrical factors at the same time. The device that can supply both tensile stimulation and electrical stimulation was produced. Cardiomyocytes were isolated by trypsin and collagenase Ⅱ combined digestion. After 72 h's culture, different electrical stimulations(0.5 V/cm, 1 V/cm, 2 V/cm;1 Hz;2 ms;30 min) and mechanical stretching force(tensile 10%, 6 h) were used to stimulate cultured cardiomyocytes respectively. Then the combinative stimulation of mechanical and electrical stimulation with 0.5 V/cm was used to apply to cardiomyocytes simultaneously. After stimulation,Connexin-43(Cx-43) mRNA level was detected by RT-PCR. The stimulation by electrical pulse of 0.5 V/cm resulted in obvious enhancement of Cx-43 m RNA level compared to the control group and the Cx-43 mRNA levels at 0.5 V/cm were higher significantly than those under both 1.0 V/cm and 2.0 V/cm. After 10% of tensile stimulation for 6 h, expressions of Cx-43 mRNA were also significantly promoted. The combinative effect of mechanical and electrical stimulation on the expression of Cx-43 mRNA is higher than that under unique tensile stimulation or electrical stimulation,which is more beneficial to the development and connection of cardiomyocytes.展开更多
The eco toxicity of Cu,Zn,Pb and Cd in the single form on the inhibition of seed germination and root elongation of turnip was tested with four types of soils (red loam soils,meadow brown soils,chestnut soils and dark...The eco toxicity of Cu,Zn,Pb and Cd in the single form on the inhibition of seed germination and root elongation of turnip was tested with four types of soils (red loam soils,meadow brown soils,chestnut soils and dark brown soils),and their combined effect was determined with meadow brown soils.Data showed that with the same content of heavy metals,the root elongation was more strongly inhibited than the seed germination,indicating that root is more sensitive to heavy metals pollution than seed germination.The inhibition rates of heavy metals on the root elongation (IRHMRE)of turnip were significantly negatively related to the contents of organic matter (OR) and Kjedahl nitrogen (K N) in soils.However,there were no significant relationship between IRHMRE and soil pH,and so does the content of T K.A slight antagonism effect in root elongation was produced when Cu,Zn,Pb and Cd were combined in the concentrations.Zn,Pb and Cd resulted in the incentive effect,while Cu gave an inhibition in the single form.Furthermore,additive effect was shown when Cu,Zn,Pb and Cd were combined in the inhibition concentrations(IC>10%)of single form.展开更多
人类和其他生物通过多重途径暴露于大量的环境污染物中。单一化合物由于其在环境中非常低的浓度使得人们忽视其可能的健康危害,然而,多种化合物在环境中同时存在,就意味着更加复杂的联合作用的可能性。Something from nothing现象引起...人类和其他生物通过多重途径暴露于大量的环境污染物中。单一化合物由于其在环境中非常低的浓度使得人们忽视其可能的健康危害,然而,多种化合物在环境中同时存在,就意味着更加复杂的联合作用的可能性。Something from nothing现象引起了科学界对于环境混合物加和作用和潜在协同作用的关注,致使许多研究联合毒性的数学和生物模型的提出和应用。本文综述了这些研究方法,以及未来化学混合物研究和管理面临的挑战。展开更多
基金National Natural Science Foundation of Chinagrant number:10802006,10925208,11120101001 and 10972024
文摘The heart is regulated by excitation-contraction mechanism and electrical stimulation, so both cardiac tissues and myocytes in vivo are affected by the mechanical and electrical factors at the same time. The device that can supply both tensile stimulation and electrical stimulation was produced. Cardiomyocytes were isolated by trypsin and collagenase Ⅱ combined digestion. After 72 h's culture, different electrical stimulations(0.5 V/cm, 1 V/cm, 2 V/cm;1 Hz;2 ms;30 min) and mechanical stretching force(tensile 10%, 6 h) were used to stimulate cultured cardiomyocytes respectively. Then the combinative stimulation of mechanical and electrical stimulation with 0.5 V/cm was used to apply to cardiomyocytes simultaneously. After stimulation,Connexin-43(Cx-43) mRNA level was detected by RT-PCR. The stimulation by electrical pulse of 0.5 V/cm resulted in obvious enhancement of Cx-43 m RNA level compared to the control group and the Cx-43 mRNA levels at 0.5 V/cm were higher significantly than those under both 1.0 V/cm and 2.0 V/cm. After 10% of tensile stimulation for 6 h, expressions of Cx-43 mRNA were also significantly promoted. The combinative effect of mechanical and electrical stimulation on the expression of Cx-43 mRNA is higher than that under unique tensile stimulation or electrical stimulation,which is more beneficial to the development and connection of cardiomyocytes.
文摘The eco toxicity of Cu,Zn,Pb and Cd in the single form on the inhibition of seed germination and root elongation of turnip was tested with four types of soils (red loam soils,meadow brown soils,chestnut soils and dark brown soils),and their combined effect was determined with meadow brown soils.Data showed that with the same content of heavy metals,the root elongation was more strongly inhibited than the seed germination,indicating that root is more sensitive to heavy metals pollution than seed germination.The inhibition rates of heavy metals on the root elongation (IRHMRE)of turnip were significantly negatively related to the contents of organic matter (OR) and Kjedahl nitrogen (K N) in soils.However,there were no significant relationship between IRHMRE and soil pH,and so does the content of T K.A slight antagonism effect in root elongation was produced when Cu,Zn,Pb and Cd were combined in the concentrations.Zn,Pb and Cd resulted in the incentive effect,while Cu gave an inhibition in the single form.Furthermore,additive effect was shown when Cu,Zn,Pb and Cd were combined in the inhibition concentrations(IC>10%)of single form.
文摘人类和其他生物通过多重途径暴露于大量的环境污染物中。单一化合物由于其在环境中非常低的浓度使得人们忽视其可能的健康危害,然而,多种化合物在环境中同时存在,就意味着更加复杂的联合作用的可能性。Something from nothing现象引起了科学界对于环境混合物加和作用和潜在协同作用的关注,致使许多研究联合毒性的数学和生物模型的提出和应用。本文综述了这些研究方法,以及未来化学混合物研究和管理面临的挑战。
