The root quality of sweet potato cultivated during the summer season is poor in northern China;thus,this study was conducted to determine whether root quality could be improved through mulching with plastic film(MPF)....The root quality of sweet potato cultivated during the summer season is poor in northern China;thus,this study was conducted to determine whether root quality could be improved through mulching with plastic film(MPF).The effect of MPF on root starch and its composition,the activity of starch synthesis enzymes,and other quality-related parameters were investigated in two purple flesh sweet potato cultivars,Jishu 18 and Ayamurasaki(Aya).The results indicated that root dry matter,anthocyanin content,adenosine triphosphate(ATP),and starch content were higher in both cultivars under the MPF treatment than those under the control treatment.The root adenosine diphosphate glucose pyrophosphorylase/uridine diphosphate glucose pyrophosphorylase(ADPGPPase/UDPGPPase)activity and adenosine triphosphatease(ATPase)activity were increased using MPF.However,under the MPF treatment,the amylose content,soluble sugar content,and granule-bound synthase(GBSS)activity increased in Jishu 18 but decreased in Aya,and the amylopectin content,protein content,and soluble starch synthase(SSS)activity decreased in Jishu 18 but increased in Aya.Therefore,MPF seems benifit to improve the quality of sweet potato,but the effects of this treatment condition may be dependent on the cultivar.展开更多
An investigation on the quality of PVC joints welded by friction stir welding （ FSW ） with different shape of pin was carried out. The results show that when the rotating speed of stir tool is 1 660 r/min and the we...An investigation on the quality of PVC joints welded by friction stir welding （ FSW ） with different shape of pin was carried out. The results show that when the rotating speed of stir tool is 1 660 r/min and the welding speed is 25 mm/min, the beads welded with upright taper pin are plump and joined well, the average tensile strength of which is 19. 1 MPa （the maximum is 20. 3 MPa）, being 49. 2% of that of parent material. The beads welded with cylindrical pin are also joined rather well plump and smooth, the average tensile strength of which is 17. 6 MPa, being 45.3% of that of parent material. The beads welded with inverted taper and cylindrical screw pin are only partially joined or disjoined. The optimum welding temperature range of PVC is 180 - 190℃. If the temperature beyond 200℃ the material will be burnt. If the temperature is under 170℃ the material will be joined partially or disjoined.展开更多
A baseline survey was carried out at four beaches along Ghana’s Accra-Tema coastline over a period of sixteen weeks to determine beach quality, seawater quality and the perception of beach users towards littering. A ...A baseline survey was carried out at four beaches along Ghana’s Accra-Tema coastline over a period of sixteen weeks to determine beach quality, seawater quality and the perception of beach users towards littering. A total of 18,241 items of marine debris which weighed 297.59 kg were collected. Plastic materials were the dominant debris, accounting for 63.72% of total debris. Land-based marine debris formed the largest proportion of debris collected (93% of items/m<sup>2</sup> and 85 kg/m<sup>2</sup>). Water quality analysis revealed high mean levels of coliforms and E. coli above World Health Organization (WHO) levels on all four beach locations. A social survey that targeted beach users and some stakeholders revealed a habit of littering and beach users as the main source of litter generation on Ghana’s beaches. Intensive education, continuous monitoring and the enforcement of appropriate policy initiatives remain vital to addressing beach and water quality issues along Ghana’s coastline.展开更多
Long-term endurance training or physical activity has been confirmed not only to improve physical performance, but to bring about an obvious beneficial effect on human health; however, the mechanism of this effect is ...Long-term endurance training or physical activity has been confirmed not only to improve physical performance, but to bring about an obvious beneficial effect on human health; however, the mechanism of this effect is not clear. The most studied health adaptations in skeletal muscle response to endurance exercise are increased muscle glycogen level and insulin sensitivity, fiber type transformation toward oxidative myofibers, and increased mitochondrial content/function. Mitochondria are dynamic organelles in eukaryotic cells critical in physical performance and disease occurrence. The mitochondrial life cycle spans biogenesis, maintenance, and clearance. Exercise training may promote each of these processes and confer positive impacts on skeletal muscle contractile and metabolic functions. This review focused on the regulation of these processes by endurance exercise and discussed its potential benefits in health and disease. We presented evidence suggesting that exercise training potentiates not only the biogenesis of mitochondria but also the removal of old and unhealthy mitochondria through mitochondrial quality control.展开更多
基金supported by the Natural Science Foundation of Shandong Province,China(ZR2014YL015)the Agricultural Seed of Shandong Province,China(2016LZGC005)+1 种基金the earmarked fund for China Agriculture Research System(CARS-10-B7 and CARS-10-B8)the Youth Foundation of Shandong Academy of Agricultural Sciences,China(2014QNM31)
文摘The root quality of sweet potato cultivated during the summer season is poor in northern China;thus,this study was conducted to determine whether root quality could be improved through mulching with plastic film(MPF).The effect of MPF on root starch and its composition,the activity of starch synthesis enzymes,and other quality-related parameters were investigated in two purple flesh sweet potato cultivars,Jishu 18 and Ayamurasaki(Aya).The results indicated that root dry matter,anthocyanin content,adenosine triphosphate(ATP),and starch content were higher in both cultivars under the MPF treatment than those under the control treatment.The root adenosine diphosphate glucose pyrophosphorylase/uridine diphosphate glucose pyrophosphorylase(ADPGPPase/UDPGPPase)activity and adenosine triphosphatease(ATPase)activity were increased using MPF.However,under the MPF treatment,the amylose content,soluble sugar content,and granule-bound synthase(GBSS)activity increased in Jishu 18 but decreased in Aya,and the amylopectin content,protein content,and soluble starch synthase(SSS)activity decreased in Jishu 18 but increased in Aya.Therefore,MPF seems benifit to improve the quality of sweet potato,but the effects of this treatment condition may be dependent on the cultivar.
文摘An investigation on the quality of PVC joints welded by friction stir welding （ FSW ） with different shape of pin was carried out. The results show that when the rotating speed of stir tool is 1 660 r/min and the welding speed is 25 mm/min, the beads welded with upright taper pin are plump and joined well, the average tensile strength of which is 19. 1 MPa （the maximum is 20. 3 MPa）, being 49. 2% of that of parent material. The beads welded with cylindrical pin are also joined rather well plump and smooth, the average tensile strength of which is 17. 6 MPa, being 45.3% of that of parent material. The beads welded with inverted taper and cylindrical screw pin are only partially joined or disjoined. The optimum welding temperature range of PVC is 180 - 190℃. If the temperature beyond 200℃ the material will be burnt. If the temperature is under 170℃ the material will be joined partially or disjoined.
文摘A baseline survey was carried out at four beaches along Ghana’s Accra-Tema coastline over a period of sixteen weeks to determine beach quality, seawater quality and the perception of beach users towards littering. A total of 18,241 items of marine debris which weighed 297.59 kg were collected. Plastic materials were the dominant debris, accounting for 63.72% of total debris. Land-based marine debris formed the largest proportion of debris collected (93% of items/m<sup>2</sup> and 85 kg/m<sup>2</sup>). Water quality analysis revealed high mean levels of coliforms and E. coli above World Health Organization (WHO) levels on all four beach locations. A social survey that targeted beach users and some stakeholders revealed a habit of littering and beach users as the main source of litter generation on Ghana’s beaches. Intensive education, continuous monitoring and the enforcement of appropriate policy initiatives remain vital to addressing beach and water quality issues along Ghana’s coastline.
基金supported by research grants from the Natural Sciences Foundation of China(31110103919,81370454,31200894,31000523,30771048,30470837,31071040,and 30270638)Tianjin Municipal Sci-tech-innovation Base Project(10KJPT024)+1 种基金General Administration of Sport of China Basic Project(10B058)National Sci-tech Support Project(2012BAK21B03)
文摘Long-term endurance training or physical activity has been confirmed not only to improve physical performance, but to bring about an obvious beneficial effect on human health; however, the mechanism of this effect is not clear. The most studied health adaptations in skeletal muscle response to endurance exercise are increased muscle glycogen level and insulin sensitivity, fiber type transformation toward oxidative myofibers, and increased mitochondrial content/function. Mitochondria are dynamic organelles in eukaryotic cells critical in physical performance and disease occurrence. The mitochondrial life cycle spans biogenesis, maintenance, and clearance. Exercise training may promote each of these processes and confer positive impacts on skeletal muscle contractile and metabolic functions. This review focused on the regulation of these processes by endurance exercise and discussed its potential benefits in health and disease. We presented evidence suggesting that exercise training potentiates not only the biogenesis of mitochondria but also the removal of old and unhealthy mitochondria through mitochondrial quality control.
