The RNA transcripted in vitro was used as the standard quantitative template to make the standard curve and establish the fluorescence quantitative RT-PCR （FQ-PCR） method. By means of FQ-PCR, the transcription chang...The RNA transcripted in vitro was used as the standard quantitative template to make the standard curve and establish the fluorescence quantitative RT-PCR （FQ-PCR） method. By means of FQ-PCR, the transcription changes of HSP70 and HSP90 mRNA in the livers and hearts of transport stressed pigs were studied. The level of HSP70 mRNA transcription increased continuously from the beginning of transportation. The inductions of HSP70 mRNA transcription in the livers and hearts of 10 h transport stressed pigs were 2.5 and 4.1 times higher than that of the un-transport stressed pigs （P〈0.01）. However, the transcription levels of HSP90 mRNA in the livers and hearts decreased with the transport stress.展开更多
Transport is an essential part of the aquaculture and research of the main freshwater aquaculture crayfish Procambarus clarkii in China.However,transport is often accompanied by a low survival rate.Assessing the physi...Transport is an essential part of the aquaculture and research of the main freshwater aquaculture crayfish Procambarus clarkii in China.However,transport is often accompanied by a low survival rate.Assessing the physiological state of P.clarkii before and after transport may discover the cause of this high mortality rate.In this study,ice-cold and exposed-to-air transport methods were compared using an array of parameters,including relative expression level of heat shock protein 70(HSP70),content of serum glucose and cortisol,immune parameters(enzyme and immune-related genes),and white spot syndrome virus(WSSV)concentration were investigated to understand the physiological state of P.clarkii before and after transport,as well as the cause of dying crayfish on days 5 and 7 after transport stress.Histological sections of hepatopancreas,gills,and intestines reflected pathological changes.The survival rate of crayfish with ice-cold transport was significantly higher than that with exposed-to-air transport,and mortality peaked at 3-9 days after transport stress.A prolonged response to oxidative stress and short-term immunosuppression was present after transport,and the trend of the WSSV concentration in the hepatopancreas was similar to the mortality rate of P.clarkii.The contents of serum glucose and cortisol,antioxidant enzymes and immune-related indexes,and the concentration of WSSV in hepatopancreas of dying crayfish were significantly higher than those of vibrant crayfish on the 5th and 7th days after transport.The hepatopancreas,intestines,and gills of dying crayfish had varying degrees of damage,and the hepatopancreas and intestines were severely damaged.The results suggested that the death of P.clarkii after transport stress is caused by oxidative stress,the imbalance of reactive oxygen species regulation,and decreased WSSV resistance,which eventually led to irreversible tissue damage.The increase of WSSV in the body of crayfish might be the direct cause of crayfish death.展开更多
Transport stress is commonly suffered by animals with gastrointestinal dysfunction a common symptom.Currently,the mechanisms of transport stress-induced intestine impairment are largely unknown.The aim of this study w...Transport stress is commonly suffered by animals with gastrointestinal dysfunction a common symptom.Currently,the mechanisms of transport stress-induced intestine impairment are largely unknown.The aim of this study was to investigate the effects of transport stress on the expression of neuronal nitric oxide synthase(nNOS)and the distribution of nNOS-positive neurons of the intestines in rats and to explore the neuroendocrine mechanism of transport stress.In this study,Sprague Dawley rats(n=6)were subjected on a constant temperature shaker for 1(S1d)or 3 d(S3d).Rats exhibited increased serum glucose and diminished total number of leukocytes,in which lymphocytes level was also decreased in the S1d group(P<0.05).Also,normal intestinal morphology was disrupted in the S1d rats,and the thickness of muscle layers was decreased in duodenum,jejunum and colon of S3d rats.In addition,it was found that nNOS expression,as well as the number of nNOSpositive neurons in the myenteric plexus were downregulated in duodenum,jejunum and colon of S3d rats compared with that of unstressed rats(P<0.05).These data reveals that transport stress induced intestinal damage and uncovers potential action mechanisms that nNOS-positive neurons and nNOS expression might be involved in modulating this process.展开更多
A finite element-based thermoelastic anisotropic stress model for hexagonal silicon carbide polytype is developed for the calculation of thermal stresses in SiC crystals grown by the physical vapor transport method. T...A finite element-based thermoelastic anisotropic stress model for hexagonal silicon carbide polytype is developed for the calculation of thermal stresses in SiC crystals grown by the physical vapor transport method. The composite structure of the growing SiC crystal and graphite lid is considered in the model. The thermal expansion match between the crucible lid and SiC crystal is studied for the first time. The influence of thermal stress on the dislocation density and crystal quality is discussed.展开更多
In recent years, more attention has been paid to the role of the glutamate transporter 1 （GLT-1, EAAT2） in major depressive disorder （MDD）. However, experimental data on brain GLT-1 levels are, to some extent, inc...In recent years, more attention has been paid to the role of the glutamate transporter 1 （GLT-1, EAAT2） in major depressive disorder （MDD）. However, experimental data on brain GLT-1 levels are, to some extent, inconsistent in human postmortem and animal studies, These discrepancies imply that the role of GLT-1 in the pathophysiology of MDD and the action of antidepressants remain obscure. This work was designed to study the impact of chronic unpredictable stress （CUS） for 2 ses- sions per day for 35 days and four weeks of fluoxetine （FLX） on depressive-like behaviors in rats, as well as the concomitant expression of the GLT-1 protein in the hippocampus. Behavioral changes were assessed by the sucrose preference and open field tests. GLT-1 levels were detected by immunohisto- chemistry and Western blot analysis. Our study demonstrated that the animals exposed to CUS showed depressive-like behaviors and exhibited a significant decrease in GLT-1 expression in the hippocampus. Chronic FLX treatment reversed the behavioral deficits and the CUS-induced decrease in GLT-1 levels. Taken together, our results support the reduction of GLT-1 in human postmortem studies in MDD and suggest that GLT-1 may be involved in the antidepressant activity of FLX. Our studies further support the notion that GLT-1 is an attractive candidate molecule associated with the fundamental processes of MDD and may be a potential, and novel pharmacological target for the treatment of MDD.展开更多
The purpose of this study was to determine the effects of road transportation under heat conditions on some haematological [Ht （haematocrit）, blood cells count and EOF （erythrocytes osmotic fragility）] and physiol...The purpose of this study was to determine the effects of road transportation under heat conditions on some haematological [Ht （haematocrit）, blood cells count and EOF （erythrocytes osmotic fragility）] and physiological [Tr （rectal temperature）, HR （heart） and RR （respiratory rates）, and circulating levels of Cor （cortisol）, Glu （glucose） and minerals] parameters in Moroccan dromedary camels. The animals were subjected to road transportation stressor for 2 h by truck during the hot-dry season. Blood samples were collected before loading and transport, and at the end of transport. Transportation induced a significant increase （P 〈 0.05） of erythrocytes count, Ht, EOF, Tr, HR and RR by comparison to values observed before transportation. The same stress conditions induced a significant increase （P 〈 0.05） of plasma Cor （ng/mL） and blood Glu （mM） （220 ± 30 vs. 137 ± 20, 9.7 ± 1.2 vs. 6.4 ± 1. 1 respectively） and a significant decrease （P 〈 0.05） of plasma magnesium （mM） （0.5 ± 0.1 vs. 0.9 ± 0.1） comparatively to pre-transportation values. These results indicate that road transportation associated to heat may be considered as a potent stressor which is able to induce several cellular alterations in camels. Further studies of an eventual protective role of vitamin C against haemolysis induced by transportation stress in camel are needed.展开更多
The high number of leak events that took place in recent years at a 25.4 cm (10”)Øpipeline transporting anhydrous liquid ammonia, located in the Southeast of Mexico, was the main reason to carry out a numb...The high number of leak events that took place in recent years at a 25.4 cm (10”)Øpipeline transporting anhydrous liquid ammonia, located in the Southeast of Mexico, was the main reason to carry out a number of field studies and laboratory tests that helped establish not only the failure causes but also mitigation and control solutions. The performed activities included direct evaluation at failure sites, total repair programs, metallographic studies and pipeline flexibility analyses. The obtained results were useful to conclude that the failures obeyed a cracking mechanism by Stress Corrosion Cracking (SCC) which was caused by the combined effect of different factors: high stress resistance, high hardness of the base metal with a microstructure prone to brittleness and residual strains originated during the pipeline construction. From the operative, logistic and financial standpoints, it is not feasible to release the stress of approximately 22 km of pipeline. Therefore, the only viable solution is to install a new pipeline with suitable fabrication, construction and installation specifications aimed at preventing the SCC phenomenon.展开更多
文摘The RNA transcripted in vitro was used as the standard quantitative template to make the standard curve and establish the fluorescence quantitative RT-PCR （FQ-PCR） method. By means of FQ-PCR, the transcription changes of HSP70 and HSP90 mRNA in the livers and hearts of transport stressed pigs were studied. The level of HSP70 mRNA transcription increased continuously from the beginning of transportation. The inductions of HSP70 mRNA transcription in the livers and hearts of 10 h transport stressed pigs were 2.5 and 4.1 times higher than that of the un-transport stressed pigs （P〈0.01）. However, the transcription levels of HSP90 mRNA in the livers and hearts decreased with the transport stress.
基金This work was supported by the Fundamental Research Funds for the Central Universities(2662020SCPY004)the National Key Research and Development Program of China(2020YFD0900304).
文摘Transport is an essential part of the aquaculture and research of the main freshwater aquaculture crayfish Procambarus clarkii in China.However,transport is often accompanied by a low survival rate.Assessing the physiological state of P.clarkii before and after transport may discover the cause of this high mortality rate.In this study,ice-cold and exposed-to-air transport methods were compared using an array of parameters,including relative expression level of heat shock protein 70(HSP70),content of serum glucose and cortisol,immune parameters(enzyme and immune-related genes),and white spot syndrome virus(WSSV)concentration were investigated to understand the physiological state of P.clarkii before and after transport,as well as the cause of dying crayfish on days 5 and 7 after transport stress.Histological sections of hepatopancreas,gills,and intestines reflected pathological changes.The survival rate of crayfish with ice-cold transport was significantly higher than that with exposed-to-air transport,and mortality peaked at 3-9 days after transport stress.A prolonged response to oxidative stress and short-term immunosuppression was present after transport,and the trend of the WSSV concentration in the hepatopancreas was similar to the mortality rate of P.clarkii.The contents of serum glucose and cortisol,antioxidant enzymes and immune-related indexes,and the concentration of WSSV in hepatopancreas of dying crayfish were significantly higher than those of vibrant crayfish on the 5th and 7th days after transport.The hepatopancreas,intestines,and gills of dying crayfish had varying degrees of damage,and the hepatopancreas and intestines were severely damaged.The results suggested that the death of P.clarkii after transport stress is caused by oxidative stress,the imbalance of reactive oxygen species regulation,and decreased WSSV resistance,which eventually led to irreversible tissue damage.The increase of WSSV in the body of crayfish might be the direct cause of crayfish death.
基金supported by the National Natural Science Foundation of China(31772686 and 31502025)the National TwelveFive Technological Supported Plan of China(2011BAD34B01)。
文摘Transport stress is commonly suffered by animals with gastrointestinal dysfunction a common symptom.Currently,the mechanisms of transport stress-induced intestine impairment are largely unknown.The aim of this study was to investigate the effects of transport stress on the expression of neuronal nitric oxide synthase(nNOS)and the distribution of nNOS-positive neurons of the intestines in rats and to explore the neuroendocrine mechanism of transport stress.In this study,Sprague Dawley rats(n=6)were subjected on a constant temperature shaker for 1(S1d)or 3 d(S3d).Rats exhibited increased serum glucose and diminished total number of leukocytes,in which lymphocytes level was also decreased in the S1d group(P<0.05).Also,normal intestinal morphology was disrupted in the S1d rats,and the thickness of muscle layers was decreased in duodenum,jejunum and colon of S3d rats.In addition,it was found that nNOS expression,as well as the number of nNOSpositive neurons in the myenteric plexus were downregulated in duodenum,jejunum and colon of S3d rats compared with that of unstressed rats(P<0.05).These data reveals that transport stress induced intestinal damage and uncovers potential action mechanisms that nNOS-positive neurons and nNOS expression might be involved in modulating this process.
基金The project supported by the National Natural Science Foundation of China (10472126)the Knowledge Innovation Program of Chinese Academy of Sciences
文摘A finite element-based thermoelastic anisotropic stress model for hexagonal silicon carbide polytype is developed for the calculation of thermal stresses in SiC crystals grown by the physical vapor transport method. The composite structure of the growing SiC crystal and graphite lid is considered in the model. The thermal expansion match between the crucible lid and SiC crystal is studied for the first time. The influence of thermal stress on the dislocation density and crystal quality is discussed.
基金supported by the Key Technology Research of Major Mental Illness Prevention and Treatment for the Barriers to the Recognition and Prevention of Depression and Anxiety in the General Hospital,China(No.2012BAI01B05)
文摘In recent years, more attention has been paid to the role of the glutamate transporter 1 （GLT-1, EAAT2） in major depressive disorder （MDD）. However, experimental data on brain GLT-1 levels are, to some extent, inconsistent in human postmortem and animal studies, These discrepancies imply that the role of GLT-1 in the pathophysiology of MDD and the action of antidepressants remain obscure. This work was designed to study the impact of chronic unpredictable stress （CUS） for 2 ses- sions per day for 35 days and four weeks of fluoxetine （FLX） on depressive-like behaviors in rats, as well as the concomitant expression of the GLT-1 protein in the hippocampus. Behavioral changes were assessed by the sucrose preference and open field tests. GLT-1 levels were detected by immunohisto- chemistry and Western blot analysis. Our study demonstrated that the animals exposed to CUS showed depressive-like behaviors and exhibited a significant decrease in GLT-1 expression in the hippocampus. Chronic FLX treatment reversed the behavioral deficits and the CUS-induced decrease in GLT-1 levels. Taken together, our results support the reduction of GLT-1 in human postmortem studies in MDD and suggest that GLT-1 may be involved in the antidepressant activity of FLX. Our studies further support the notion that GLT-1 is an attractive candidate molecule associated with the fundamental processes of MDD and may be a potential, and novel pharmacological target for the treatment of MDD.
文摘The purpose of this study was to determine the effects of road transportation under heat conditions on some haematological [Ht （haematocrit）, blood cells count and EOF （erythrocytes osmotic fragility）] and physiological [Tr （rectal temperature）, HR （heart） and RR （respiratory rates）, and circulating levels of Cor （cortisol）, Glu （glucose） and minerals] parameters in Moroccan dromedary camels. The animals were subjected to road transportation stressor for 2 h by truck during the hot-dry season. Blood samples were collected before loading and transport, and at the end of transport. Transportation induced a significant increase （P 〈 0.05） of erythrocytes count, Ht, EOF, Tr, HR and RR by comparison to values observed before transportation. The same stress conditions induced a significant increase （P 〈 0.05） of plasma Cor （ng/mL） and blood Glu （mM） （220 ± 30 vs. 137 ± 20, 9.7 ± 1.2 vs. 6.4 ± 1. 1 respectively） and a significant decrease （P 〈 0.05） of plasma magnesium （mM） （0.5 ± 0.1 vs. 0.9 ± 0.1） comparatively to pre-transportation values. These results indicate that road transportation associated to heat may be considered as a potent stressor which is able to induce several cellular alterations in camels. Further studies of an eventual protective role of vitamin C against haemolysis induced by transportation stress in camel are needed.
文摘The high number of leak events that took place in recent years at a 25.4 cm (10”)Øpipeline transporting anhydrous liquid ammonia, located in the Southeast of Mexico, was the main reason to carry out a number of field studies and laboratory tests that helped establish not only the failure causes but also mitigation and control solutions. The performed activities included direct evaluation at failure sites, total repair programs, metallographic studies and pipeline flexibility analyses. The obtained results were useful to conclude that the failures obeyed a cracking mechanism by Stress Corrosion Cracking (SCC) which was caused by the combined effect of different factors: high stress resistance, high hardness of the base metal with a microstructure prone to brittleness and residual strains originated during the pipeline construction. From the operative, logistic and financial standpoints, it is not feasible to release the stress of approximately 22 km of pipeline. Therefore, the only viable solution is to install a new pipeline with suitable fabrication, construction and installation specifications aimed at preventing the SCC phenomenon.
