Iron is considered as an attractive alternative material for bioresorbable scaffolds(BRS).The sirolimus eluting iron bioresorbable scaffold(IBS),developed by Biotyx Medical(Shenzhen,China),is the only iron-based BRS w...Iron is considered as an attractive alternative material for bioresorbable scaffolds(BRS).The sirolimus eluting iron bioresorbable scaffold(IBS),developed by Biotyx Medical(Shenzhen,China),is the only iron-based BRS with an ultrathin-wall design.The study aims to investigate the long-term efficacy,safety,biocompatibility,and lumen changes during the biodegradation process of the IBS in a porcine model.A total of 90 IBSs and 70 cobaltchromium everolimus eluting stents(EES)were randomly implanted into nonatherosclerotic coronary artery of healthy mini swine.The multimodality assessments including coronary angiography,optical coherence tomography,micro-computed tomography,magnetic resonance imaging,real-time polymerase chain reaction(PCR),and histopathological evaluations,were performed at different time points.There was no statistical difference in area stenosis between IBS group and EES group at 6 months,1year,2 years and 5 years.Although the scaffolded vessels narrowed at 9 months,expansive remodeling with increased mean lumen area was found at 3 and 5 years.The IBS struts remained intact at 6 months,and the corrosion was detectable at 9 months.At 5 years,the iron struts were completely degraded and absorbed in situ,without in-scaffold restenosis or thrombosis,lumen collapse,aneurysm formation,and chronic inflammation.No local or systemic toxicity and abnormal histopathologic manifestation were found in all experiments.Results from real-time PCR indicated that no sign of iron overload was reported in scaffolded segments.Therefore,the IBS shows comparable efficacy,safety,and biocompatibility with EES,and late lumen enlargement is considered as a unique feature in the IBS-implanted vessels.展开更多
Ammonia volatilized from aboveground parts of winter wheat was collected with an enclosure growth chamber and measured from jointing to maturing stage. The results showed that ammonia released from unfertilized plants...Ammonia volatilized from aboveground parts of winter wheat was collected with an enclosure growth chamber and measured from jointing to maturing stage. The results showed that ammonia released from unfertilized plants grown in high and low fertility soils remained at low rates of 2.3 and 0. 9μg NH3 40 plant-1 h-1 respectively at late filling stage. However, fertilized plants rapidly increased the rates to 43. 4 and 52. 2μg NH3, 40 plant-1 h-1 in the high and low fertility soils, respectively, at the same period. The released a-mount was different in different parts of plants. At filling stage, lower senescing stems and leaves volatilized more ammonia than upper parts, i. e. , ears and flag leaves that grew normally, with an average of 1. 4 and 0.7μg NH3 20 plant-1 h-1 respectively, strongly suggesting that it was the senile organs that released large amounts of ammonia. At the grain filling stage, shortage of water supply (drought stress) reduced ammonia volatilization. The average rate of ammonia released under water stress was 0. 9μg NH3 40 plant-1 h-1, but 1.2μg NH3 40 plant-1 h-1 with moderate water supply. Application of N together with P fertilizer resulted in a higher ammonia volatilization than N fertilization alone at the maturing stage. The average rate released was 135.3 μg NH3 40 plant-1 h-1 when 0.4 g N and 0.13 g P had been added to per kg soil, while 33. 7μg when 0. 4 g N added alone. Ammonia volatilization from plants was closely related with plant biomass and N uptake;P fertilization increased plant biomass and N uptake and therefore increased its release.展开更多
A mean annual loss rate(MALR) is a measure of the damaging degree of different crops to agroclimatic calamities such as waterlogging, strong win4 hail and dry-hot wind. It is useful for assessing regional insurance Pr...A mean annual loss rate(MALR) is a measure of the damaging degree of different crops to agroclimatic calamities such as waterlogging, strong win4 hail and dry-hot wind. It is useful for assessing regional insurance Premium. Based on the meteorological data observed from 1961 to 1993 in Hebei province and the damaging grades of some crops to meteorological disasters, we establish the index systems of agroclimatic calamities and then calculate the MALR with hierarchical models. Finally, GIS-based spatial maps on MALR has been employed to exhibit regional differentiation of mean annual loss rate of crops.展开更多
In this research,an econometric with panel data using Ordinary least squares OLS model is constructed following the guidelines recommended by the EBA stress test methodology for 2016.The findings indicate that macroec...In this research,an econometric with panel data using Ordinary least squares OLS model is constructed following the guidelines recommended by the EBA stress test methodology for 2016.The findings indicate that macroeconomic factors affecting defaults are the expected ones in the Spanish credit institutions.However,loan impairments do not follow the patterns that a priori would be normal.Divergent is outcomes in defaults and impairments:the Non-Performing Loans(NPL)is pro-cyclical and impairment losses are counter-cyclical.展开更多
Background Sirolimus-eluting stents （SES） are reported to be associated with reduced late lumen loss （LLL）, resulting in less frequent restenosis when compared to bare-metal stent. The current study aimed to asses...Background Sirolimus-eluting stents （SES） are reported to be associated with reduced late lumen loss （LLL）, resulting in less frequent restenosis when compared to bare-metal stent. The current study aimed to assess the difference in LLL between SES with biodegradable and with permanent polymer. Methods From March 2010 to June 2011, 300 consecutive patients having only biodegradable polymers or permanent polymer SES for all diseased vessels were included. Serial quantitative coronary analysis was performed on both the ＂in-stent＂ and ＂segment＂ area, including the stented segment, as well as both five mm margins proximal and distal to the stent. The primary endpoint was the LLL defined as the minimal lumen diameter （MLD） post-stenting minus the MLD at nine-month after the indexed procedure. Results LLL was comparable between the two stents. Importantly, LLL for the distal segment （median 0.05 mm, interquartile 0 to 0.09 mm） was less severe compared with in-stent （median 0.13 mm, interquartile 0.08 to 0.18 mm） and proximal segment LLL （median 0.12 mm, interquartile 0.06 to 0.14 mm, all P 〈0.001 ）. In general, the LLL was associated with the post-procedure MLD （b=0.28, P=0.002）, hyperlipidemia （b=0.14, P=0.021）, and calcified lesions （b=0.58, P=-0.001）. The R2 and Radj of the multiple regression model were 0.651 and 0.625, respectively. Conclusions SES with either biodegradable or permanent polymer had lower value of LLL. The small amount of LLL at the distal segment possibly contributed to the less distal edge stenosis.展开更多
【目的】针对稻田氮磷钾肥施用不合理引起环境问题较为严重的现象,从粮食高产高效和环境效益的角度分析稻田化肥的合理施用与管理策略。【方法】选用测土配方施肥项目2005—2010年在湖南省间布置的735个早、中、晚稻肥料田间试验,选取...【目的】针对稻田氮磷钾肥施用不合理引起环境问题较为严重的现象,从粮食高产高效和环境效益的角度分析稻田化肥的合理施用与管理策略。【方法】选用测土配方施肥项目2005—2010年在湖南省间布置的735个早、中、晚稻肥料田间试验,选取不施肥(CK)、农民习惯施肥(FP)和优化施肥(OPT)3个处理,对比分析了早、中、晚稻OPT较FP处理的增产效果与氮、磷、钾肥偏生产力的优势;通过筛选OPT处理产量或/和氮肥偏生产力前25%的试验点,建立高产、高效和高产高效3种方案,结合氮肥用量与氮素损失(N2O的排放、N的径流与淋失、NH3挥发)之间的经验模型,评估稻田节氮减排潜力;通过计算早、中、晚稻磷素表观平衡,分析稻田磷素残留状况;并引入湖南省早、中、晚稻种植面积,估算区域稻田氮、磷的环境效益。【结果】多年多点田间试验研究表明,与CK处理相比,FP和OPT处理分别可增产41.9%和52.0%(早、中、晚稻的平均值);与FP处理相比,OPT处理早、中、晚稻可增产7.0%—8.3%,氮、磷肥偏生产力分别提高16.8%—19.6%和5.5%—37.3%,而OPT处理钾肥用量的提高对钾肥偏生产力的负效应较小(早、中、晚稻平均降幅为6.4%)。节氮减排评估结果表明,高产组产量高而氮肥用量相对较高,高效组氮肥偏生产力高而产量相对较低,用高产高效组表征产量和氮肥偏生产力的潜力更可靠;高产高效组早、中、晚稻每年可节省氮肥用量共81 kg·hm^(-2)(其中晚稻最多,为32 kg N·hm^(-2)),减少氮素损失15.5 kg N·hm^(-2),温室气体N2O减排约20%。湖南省稻田节氮总潜力为12.5×10~4 t,减少氮素损失2.35×10~4 t,主要对象为早稻和晚稻。优化施肥可提水稻的磷素总吸收量,早、中、晚稻从FP处理的59—66 kg P2O5·hm^(-2)增加到OPT处理的63—71 kg P2O5·hm^(-2)。磷肥用量与水稻磷素吸收量之间的关系显示,两者并不能达到显著的正向相关关系,说明当磷肥投入总量满足作物需求后,多余的磷素对当季作物磷素吸收无效,从而残留在土壤中;早、中、晚稻分别有46%、44%和15%的样本出现磷残留现象,通过筛选并分析磷残留样本得出,早、中、晚稻OPT处理磷残留比例明显低于FP处理,且磷残留量分别可降低到1.36—5.30 kg P2O5·hm^(-2),较FP处理下降了33.7%—48.5%;从全省范围来看,磷残留总量可减少18.14×10~3、3.59×10~3和5.30×10~3 t;另一方面,农民习惯施肥中,仍有不施磷肥的现象,这对土壤养分的耗竭影响较大,应重视平衡施肥。【结论】稻田优化施肥是产量和环境安全的重要保障,氮肥减量施用可提高氮肥利用率,减少氮素损失和温室气体的排放,控制磷肥总量可有效地避免土壤磷素残留带来的污染风险。展开更多
基金supported by National Key R&D Program of China(grant number 2018YFC1106600)Shenzhen Industrial and Information Technology Bureau(20180309174916657)+1 种基金Science,Technology and Innovation Commission of Shenzhen Municipality(grant number GJHZ20180418190517302)Natural Science Foundation of China(grant number 52101282).
文摘Iron is considered as an attractive alternative material for bioresorbable scaffolds(BRS).The sirolimus eluting iron bioresorbable scaffold(IBS),developed by Biotyx Medical(Shenzhen,China),is the only iron-based BRS with an ultrathin-wall design.The study aims to investigate the long-term efficacy,safety,biocompatibility,and lumen changes during the biodegradation process of the IBS in a porcine model.A total of 90 IBSs and 70 cobaltchromium everolimus eluting stents(EES)were randomly implanted into nonatherosclerotic coronary artery of healthy mini swine.The multimodality assessments including coronary angiography,optical coherence tomography,micro-computed tomography,magnetic resonance imaging,real-time polymerase chain reaction(PCR),and histopathological evaluations,were performed at different time points.There was no statistical difference in area stenosis between IBS group and EES group at 6 months,1year,2 years and 5 years.Although the scaffolded vessels narrowed at 9 months,expansive remodeling with increased mean lumen area was found at 3 and 5 years.The IBS struts remained intact at 6 months,and the corrosion was detectable at 9 months.At 5 years,the iron struts were completely degraded and absorbed in situ,without in-scaffold restenosis or thrombosis,lumen collapse,aneurysm formation,and chronic inflammation.No local or systemic toxicity and abnormal histopathologic manifestation were found in all experiments.Results from real-time PCR indicated that no sign of iron overload was reported in scaffolded segments.Therefore,the IBS shows comparable efficacy,safety,and biocompatibility with EES,and late lumen enlargement is considered as a unique feature in the IBS-implanted vessels.
基金This work was part of the projects of 40201028,30070429,49890330 and 30230230 supported by the National Natural Science Foundation of China(NFSC)the project of G1999011707 supported by National Key Basic Research Special Funds(NKBRSF).The authors would like to take the opportunity to thank the NFSC and the NKBRSF for their kindness of supporting these projects.
文摘Ammonia volatilized from aboveground parts of winter wheat was collected with an enclosure growth chamber and measured from jointing to maturing stage. The results showed that ammonia released from unfertilized plants grown in high and low fertility soils remained at low rates of 2.3 and 0. 9μg NH3 40 plant-1 h-1 respectively at late filling stage. However, fertilized plants rapidly increased the rates to 43. 4 and 52. 2μg NH3, 40 plant-1 h-1 in the high and low fertility soils, respectively, at the same period. The released a-mount was different in different parts of plants. At filling stage, lower senescing stems and leaves volatilized more ammonia than upper parts, i. e. , ears and flag leaves that grew normally, with an average of 1. 4 and 0.7μg NH3 20 plant-1 h-1 respectively, strongly suggesting that it was the senile organs that released large amounts of ammonia. At the grain filling stage, shortage of water supply (drought stress) reduced ammonia volatilization. The average rate of ammonia released under water stress was 0. 9μg NH3 40 plant-1 h-1, but 1.2μg NH3 40 plant-1 h-1 with moderate water supply. Application of N together with P fertilizer resulted in a higher ammonia volatilization than N fertilization alone at the maturing stage. The average rate released was 135.3 μg NH3 40 plant-1 h-1 when 0.4 g N and 0.13 g P had been added to per kg soil, while 33. 7μg when 0. 4 g N added alone. Ammonia volatilization from plants was closely related with plant biomass and N uptake;P fertilization increased plant biomass and N uptake and therefore increased its release.
文摘A mean annual loss rate(MALR) is a measure of the damaging degree of different crops to agroclimatic calamities such as waterlogging, strong win4 hail and dry-hot wind. It is useful for assessing regional insurance Premium. Based on the meteorological data observed from 1961 to 1993 in Hebei province and the damaging grades of some crops to meteorological disasters, we establish the index systems of agroclimatic calamities and then calculate the MALR with hierarchical models. Finally, GIS-based spatial maps on MALR has been employed to exhibit regional differentiation of mean annual loss rate of crops.
文摘In this research,an econometric with panel data using Ordinary least squares OLS model is constructed following the guidelines recommended by the EBA stress test methodology for 2016.The findings indicate that macroeconomic factors affecting defaults are the expected ones in the Spanish credit institutions.However,loan impairments do not follow the patterns that a priori would be normal.Divergent is outcomes in defaults and impairments:the Non-Performing Loans(NPL)is pro-cyclical and impairment losses are counter-cyclical.
文摘Background Sirolimus-eluting stents （SES） are reported to be associated with reduced late lumen loss （LLL）, resulting in less frequent restenosis when compared to bare-metal stent. The current study aimed to assess the difference in LLL between SES with biodegradable and with permanent polymer. Methods From March 2010 to June 2011, 300 consecutive patients having only biodegradable polymers or permanent polymer SES for all diseased vessels were included. Serial quantitative coronary analysis was performed on both the ＂in-stent＂ and ＂segment＂ area, including the stented segment, as well as both five mm margins proximal and distal to the stent. The primary endpoint was the LLL defined as the minimal lumen diameter （MLD） post-stenting minus the MLD at nine-month after the indexed procedure. Results LLL was comparable between the two stents. Importantly, LLL for the distal segment （median 0.05 mm, interquartile 0 to 0.09 mm） was less severe compared with in-stent （median 0.13 mm, interquartile 0.08 to 0.18 mm） and proximal segment LLL （median 0.12 mm, interquartile 0.06 to 0.14 mm, all P 〈0.001 ）. In general, the LLL was associated with the post-procedure MLD （b=0.28, P=0.002）, hyperlipidemia （b=0.14, P=0.021）, and calcified lesions （b=0.58, P=-0.001）. The R2 and Radj of the multiple regression model were 0.651 and 0.625, respectively. Conclusions SES with either biodegradable or permanent polymer had lower value of LLL. The small amount of LLL at the distal segment possibly contributed to the less distal edge stenosis.
文摘【目的】针对稻田氮磷钾肥施用不合理引起环境问题较为严重的现象,从粮食高产高效和环境效益的角度分析稻田化肥的合理施用与管理策略。【方法】选用测土配方施肥项目2005—2010年在湖南省间布置的735个早、中、晚稻肥料田间试验,选取不施肥(CK)、农民习惯施肥(FP)和优化施肥(OPT)3个处理,对比分析了早、中、晚稻OPT较FP处理的增产效果与氮、磷、钾肥偏生产力的优势;通过筛选OPT处理产量或/和氮肥偏生产力前25%的试验点,建立高产、高效和高产高效3种方案,结合氮肥用量与氮素损失(N2O的排放、N的径流与淋失、NH3挥发)之间的经验模型,评估稻田节氮减排潜力;通过计算早、中、晚稻磷素表观平衡,分析稻田磷素残留状况;并引入湖南省早、中、晚稻种植面积,估算区域稻田氮、磷的环境效益。【结果】多年多点田间试验研究表明,与CK处理相比,FP和OPT处理分别可增产41.9%和52.0%(早、中、晚稻的平均值);与FP处理相比,OPT处理早、中、晚稻可增产7.0%—8.3%,氮、磷肥偏生产力分别提高16.8%—19.6%和5.5%—37.3%,而OPT处理钾肥用量的提高对钾肥偏生产力的负效应较小(早、中、晚稻平均降幅为6.4%)。节氮减排评估结果表明,高产组产量高而氮肥用量相对较高,高效组氮肥偏生产力高而产量相对较低,用高产高效组表征产量和氮肥偏生产力的潜力更可靠;高产高效组早、中、晚稻每年可节省氮肥用量共81 kg·hm^(-2)(其中晚稻最多,为32 kg N·hm^(-2)),减少氮素损失15.5 kg N·hm^(-2),温室气体N2O减排约20%。湖南省稻田节氮总潜力为12.5×10~4 t,减少氮素损失2.35×10~4 t,主要对象为早稻和晚稻。优化施肥可提水稻的磷素总吸收量,早、中、晚稻从FP处理的59—66 kg P2O5·hm^(-2)增加到OPT处理的63—71 kg P2O5·hm^(-2)。磷肥用量与水稻磷素吸收量之间的关系显示,两者并不能达到显著的正向相关关系,说明当磷肥投入总量满足作物需求后,多余的磷素对当季作物磷素吸收无效,从而残留在土壤中;早、中、晚稻分别有46%、44%和15%的样本出现磷残留现象,通过筛选并分析磷残留样本得出,早、中、晚稻OPT处理磷残留比例明显低于FP处理,且磷残留量分别可降低到1.36—5.30 kg P2O5·hm^(-2),较FP处理下降了33.7%—48.5%;从全省范围来看,磷残留总量可减少18.14×10~3、3.59×10~3和5.30×10~3 t;另一方面,农民习惯施肥中,仍有不施磷肥的现象,这对土壤养分的耗竭影响较大,应重视平衡施肥。【结论】稻田优化施肥是产量和环境安全的重要保障,氮肥减量施用可提高氮肥利用率,减少氮素损失和温室气体的排放,控制磷肥总量可有效地避免土壤磷素残留带来的污染风险。
