There is a cyclical aperture at a certain part of the fiberglass reinforced plastic compound pipeline with a stainless steel pipe as a liner, which becomes the weakness of the conduit. The field of stress and strain o...There is a cyclical aperture at a certain part of the fiberglass reinforced plastic compound pipeline with a stainless steel pipe as a liner, which becomes the weakness of the conduit. The field of stress and strain of the aperture was investigated using the nonliner finite element code Marc. The results of the finite element analysis showed that there were concentrations of stress and strain in the layer of stainless steel at the part of the pipeline where the aperture existed. The method to solve these problems was also discussed.展开更多
With the global warming and climate change in recent years, heat stress has become one of the major abiotic factors constraining production and productivity of crops in many regions around the world. Although the plan...With the global warming and climate change in recent years, heat stress has become one of the major abiotic factors constraining production and productivity of crops in many regions around the world. Although the plants have developed some adaptive behaviors and avoidance mechanisms against heat stress, they will be hurt under extreme high temperature. Exogenous compounds could enhance plant growth and development, antioxidant enzymes activities, chlorophyll and nutrient contents under stress conditions. Meanwhile, application of exogenous compounds sustains physiological and biochemical process and prevents plants from physiological changes under stress conditions. In this review, effects of heat stress upon crops, and the functions of hormones in plant adaptation to heat stress are simply stated. Then, we intend to appraise how various phytohomrnones that are related to plant adaptation to heat stress. The role of abscisic acid(ABA), salicylic acid(SA) and polyamines(putrescine and spermine) under heat stress conditions are mainly discussed.展开更多
Objective: To investigate the effect of Compound Danshen Dripping Pills (CDDP) on oxidative stress after ischemia/reperfusion (I/R) injury in the rat retina. Methods: Adult male SD rats were randomly divided into 3 gr...Objective: To investigate the effect of Compound Danshen Dripping Pills (CDDP) on oxidative stress after ischemia/reperfusion (I/R) injury in the rat retina. Methods: Adult male SD rats were randomly divided into 3 groups: sham (group A), I/R (group B), and I/R plus CDDP (group C). Retinal ischemia/reperfusion injury (RIRI) was introduced by increasing the intraocular pressure (IOP) to 110 mmHg for 60 min via cannulation into the anterior chamber. Right after the insult, CDDP was administered intragastrically (450 mg/kg/d) for 7 days. The levels of malondialdehyde (MDA), the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) in the retinal tissues were determined on d1 and d7 after the ischemic insult. Results: Following ischemia, the MDA levels in group B and group C were significantly higher than those in group A (p < 0.01). CDDP significantly lowered MDA levels in group C when compared with group B (p < 0.01). The activities of SOD, GSH-Px and CAT were higher in group A than in group B and group C (p < 0.01). CDDP could increase the activities of SOD, GSH-Px and CAT remarkably in group C when compared with group B (p < 0.01). Conclusion: CDDP can protect the retina from I/R injury through reducing oxidative stress, and thus may be a promising method for the treatment of ischemic retinal disorders.展开更多
文摘There is a cyclical aperture at a certain part of the fiberglass reinforced plastic compound pipeline with a stainless steel pipe as a liner, which becomes the weakness of the conduit. The field of stress and strain of the aperture was investigated using the nonliner finite element code Marc. The results of the finite element analysis showed that there were concentrations of stress and strain in the layer of stainless steel at the part of the pipeline where the aperture existed. The method to solve these problems was also discussed.
基金Supported by Natural Science Foundation of Hubei Province(2013CFA011)
文摘With the global warming and climate change in recent years, heat stress has become one of the major abiotic factors constraining production and productivity of crops in many regions around the world. Although the plants have developed some adaptive behaviors and avoidance mechanisms against heat stress, they will be hurt under extreme high temperature. Exogenous compounds could enhance plant growth and development, antioxidant enzymes activities, chlorophyll and nutrient contents under stress conditions. Meanwhile, application of exogenous compounds sustains physiological and biochemical process and prevents plants from physiological changes under stress conditions. In this review, effects of heat stress upon crops, and the functions of hormones in plant adaptation to heat stress are simply stated. Then, we intend to appraise how various phytohomrnones that are related to plant adaptation to heat stress. The role of abscisic acid(ABA), salicylic acid(SA) and polyamines(putrescine and spermine) under heat stress conditions are mainly discussed.
文摘Objective: To investigate the effect of Compound Danshen Dripping Pills (CDDP) on oxidative stress after ischemia/reperfusion (I/R) injury in the rat retina. Methods: Adult male SD rats were randomly divided into 3 groups: sham (group A), I/R (group B), and I/R plus CDDP (group C). Retinal ischemia/reperfusion injury (RIRI) was introduced by increasing the intraocular pressure (IOP) to 110 mmHg for 60 min via cannulation into the anterior chamber. Right after the insult, CDDP was administered intragastrically (450 mg/kg/d) for 7 days. The levels of malondialdehyde (MDA), the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) in the retinal tissues were determined on d1 and d7 after the ischemic insult. Results: Following ischemia, the MDA levels in group B and group C were significantly higher than those in group A (p < 0.01). CDDP significantly lowered MDA levels in group C when compared with group B (p < 0.01). The activities of SOD, GSH-Px and CAT were higher in group A than in group B and group C (p < 0.01). CDDP could increase the activities of SOD, GSH-Px and CAT remarkably in group C when compared with group B (p < 0.01). Conclusion: CDDP can protect the retina from I/R injury through reducing oxidative stress, and thus may be a promising method for the treatment of ischemic retinal disorders.
