Accumulating studies have proved that perinatal exposure to environmental dose causes long-term potentiation in anxiety/depression-related behaviors in rats. Hyperactivity of the hypothalamic-pituitary-adrenal (HPA)...Accumulating studies have proved that perinatal exposure to environmental dose causes long-term potentiation in anxiety/depression-related behaviors in rats. Hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis is one of the most consistent biological findings in anxiety- and depression-related disorders. The HPA axis is reported to be susceptible to developmental reprogramming. The present study focused on HPA reactivity in postnatal day (PND) 80 male rats exposed perinatally to environmental-dose BPA. When female breeders were orally administered 2 μg/(kg.day) BPA from gestation day 10 to lactation day 7, their offspring (PND 80 BPA-exposed rats) showed obvious anxiety/depression-like behaviors. Notably, significant increase in serum corticosterone and adrenocorticotropin, and corticotropin-releasing hormone mRNA were detected in BPA-exposed rats before or after the mild stressor. Additionally, the level of glucocorticoid receptor mRNA in the hippocampus, but not the hypothalamus, was decreased in BPA-exposed rats. The levels of hippocampal mineralocorticoid receptor mRNA, neuronal nitric oxide synthase and phosphorylated cAMP response element binding protein were increased in BPA-exposed rats. In addition, the testosterone level was in BPA-exposed rats. The results indicate that reprogramming-induced hyperactivity of the HPA axis is an important link between perinatal BPA exposure and persistent potentiation in anxiety and depression.展开更多
Objective The Juhugeng mining area in Qinghai Province of northwest China has attracted wide attention among geologists for it hosts typical coal measure gases.The shale gas reservoirs were reformed by intensive struc...Objective The Juhugeng mining area in Qinghai Province of northwest China has attracted wide attention among geologists for it hosts typical coal measure gases.The shale gas reservoirs were reformed by intensive structural movements during geological periods,展开更多
As one of the indispensable actuating components in micro-systems,the shafted microgear is in great production demand.Microforming is a manufacturing process to produce microgears to meet the needs.Due to the small ge...As one of the indispensable actuating components in micro-systems,the shafted microgear is in great production demand.Microforming is a manufacturing process to produce microgears to meet the needs.Due to the small geometrical size,there are uncertain process performance and product quality issues in this production process.In this study,the shafted microgears were fabricated in two different scaling factors with four grain sizes using a progressively extrusion-blanking method.To explore the unknown of the process,grain-based modeling was proposed and employed to simulate the entire forming process.The results show that when the grains are large,the anisotropy of single grains has an obvious size effect on the forming behavior and process performance;and the produced geometries and surface quality are worsened;and the deformation load is decreased.Five deformation zones were identified in the microstructures with different hardness and distributions of stress and strain.The simulation by using the proposed model successfully predicted the formation of zones and revealed the inhomogeneous deformation in the forming process.The undesirable geometries of microgears including material unfilling,burr and inclination were observed on the shaft and teeth of gear,and the inclination size is increased obviously with grain size.To avoid the formation of inclination and material unfilling,the punch was redesigned,and a die insert was added to constraint the bottom surface of the gear teeth.The new products had then the better forming quality.展开更多
基金supported by China Postdoctoral Science Foundation(2013M540456)Jiangsu Planned Projects for Postdoctoral Research Funds(1301065B)+3 种基金Grants for 973(2014CB943303)NSFC(810710273117144081000482)
文摘Accumulating studies have proved that perinatal exposure to environmental dose causes long-term potentiation in anxiety/depression-related behaviors in rats. Hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis is one of the most consistent biological findings in anxiety- and depression-related disorders. The HPA axis is reported to be susceptible to developmental reprogramming. The present study focused on HPA reactivity in postnatal day (PND) 80 male rats exposed perinatally to environmental-dose BPA. When female breeders were orally administered 2 μg/(kg.day) BPA from gestation day 10 to lactation day 7, their offspring (PND 80 BPA-exposed rats) showed obvious anxiety/depression-like behaviors. Notably, significant increase in serum corticosterone and adrenocorticotropin, and corticotropin-releasing hormone mRNA were detected in BPA-exposed rats before or after the mild stressor. Additionally, the level of glucocorticoid receptor mRNA in the hippocampus, but not the hypothalamus, was decreased in BPA-exposed rats. The levels of hippocampal mineralocorticoid receptor mRNA, neuronal nitric oxide synthase and phosphorylated cAMP response element binding protein were increased in BPA-exposed rats. In addition, the testosterone level was in BPA-exposed rats. The results indicate that reprogramming-induced hyperactivity of the HPA axis is an important link between perinatal BPA exposure and persistent potentiation in anxiety and depression.
基金supported by the National Natural Science Foundation of China(grant No.41572141)
文摘Objective The Juhugeng mining area in Qinghai Province of northwest China has attracted wide attention among geologists for it hosts typical coal measure gases.The shale gas reservoirs were reformed by intensive structural movements during geological periods,
基金The authors would like to acknowledge the funding support to this research from the projects of ZE1W and BBAT from The Hong Kong Polytechnic University,the National Natural Science Foundation of China(NSFC)(Grant No.51835011)the General Research Fund(GRF)(Grant No.15223520).
文摘As one of the indispensable actuating components in micro-systems,the shafted microgear is in great production demand.Microforming is a manufacturing process to produce microgears to meet the needs.Due to the small geometrical size,there are uncertain process performance and product quality issues in this production process.In this study,the shafted microgears were fabricated in two different scaling factors with four grain sizes using a progressively extrusion-blanking method.To explore the unknown of the process,grain-based modeling was proposed and employed to simulate the entire forming process.The results show that when the grains are large,the anisotropy of single grains has an obvious size effect on the forming behavior and process performance;and the produced geometries and surface quality are worsened;and the deformation load is decreased.Five deformation zones were identified in the microstructures with different hardness and distributions of stress and strain.The simulation by using the proposed model successfully predicted the formation of zones and revealed the inhomogeneous deformation in the forming process.The undesirable geometries of microgears including material unfilling,burr and inclination were observed on the shaft and teeth of gear,and the inclination size is increased obviously with grain size.To avoid the formation of inclination and material unfilling,the punch was redesigned,and a die insert was added to constraint the bottom surface of the gear teeth.The new products had then the better forming quality.