Carbon accumulation and spatial distribution as well as their variations in three different age(8-year-old,14-year-old and 28-year-old) stands of Taiwania flousiana plantation ecosystem were investigated in Nandan Sha...Carbon accumulation and spatial distribution as well as their variations in three different age(8-year-old,14-year-old and 28-year-old) stands of Taiwania flousiana plantation ecosystem were investigated in Nandan Shankou Forestry Station of Guangxi,China. The results showed that carbon content in different organs of T.flousiana ranged form 418.4 g·kg-1 to 516.4 g·kg-1,which was in order as follows:bark>branch>stem>root>leaf. The vertical distribution of carbon content within the stand was in the following order:tree layer>shrub layer>herb layer.Carbon content in the soil obviously declined with increased soil depth from 0 to 80 cm. Total carbon storage in the ecosystems was 159.37,194.21 and 278.22 t·hm-2,respectively for 8-year-old,14-yea-old and 28-yea-old stands. The tree layer in the three-age stands respectively accounted for 18.30%、28.37% and 43.59%;the shrub and herb layers for 0.14%、1.17% and 1.44%;the litter layer for 0.33%、0.89% and 1.11%;the soil for 81.23%、69.58% and 54.78% of the total storage of carbon. Carbon storage in different organs was roughly in proportion to the biomass of corresponding organ. For example,stem occupied the greatest proportion of carbon storage in the trees,up to 46.37%,and increased with the stand age while branches,leaves,bark and roots occupied more than 37.32%. The annual net productivity of the 8-year-old,14-year-old and 28-year-old T.flousiana plantation was respectively 8.93,10.82 and 12.53 t·hm-2a-1,and annual net carbon storage was respectively 4.19,5.07 and 5.93 t·hm-2a-1.展开更多
脑静脉及静脉窦血栓形成(CVT)是一种罕见的疾病,占所有卒中的不到1%。由于临床症状的多样性,且亚急性或慢性发作,常被忽视甚至误诊。目前临床上CVT的治疗措施主要有:(1)抗凝,包括静脉用肝素(根据剂量调整)或皮下低分子量肝素(根据体重调...脑静脉及静脉窦血栓形成(CVT)是一种罕见的疾病,占所有卒中的不到1%。由于临床症状的多样性,且亚急性或慢性发作,常被忽视甚至误诊。目前临床上CVT的治疗措施主要有:(1)抗凝,包括静脉用肝素(根据剂量调整)或皮下低分子量肝素(根据体重调整);(2)溶栓治疗;(3)对症治疗:包括抗癫治疗和降低颅高压。欧洲神经科学联盟(EFNS)专家组查阅了MEDLINE、the Cochrane Central Register of Controlled Trials(CENTRAL)和Cochrane图书馆数据库相关文献,提出了CVT治疗方案。对于目前仍缺乏证据的方面,专家组在指南中清楚的陈述了依据临床实践作出的指导意见:(1)没有抗凝禁忌证的情况下,CVT患者应该给予皮下低分子肝素或静脉使用肝素治疗。(2)CVT伴随的颅内出血不是肝素治疗的禁忌证。(3)急性期后口服抗凝药最佳持续时间目前尚不确定。如果CVT继发于短暂的危险因素,口服抗凝药可给3个月,先天性CVT和轻度遗传性血栓形成倾向的患者可给6～12个月。对于发生两次以上CVT患者及具有明显遗传性血栓形成倾向者,可考虑长期抗凝治疗。(4)目前仍缺乏有力的证据表明CVT患者需采用全身性或局部溶栓治疗。对于重症、病情不断恶化及抗凝治疗无效的患者,主张使用溶栓治疗。(5)对于严重CVT患者,颅高压明显,一般治疗效果不满意者,抗水肿治疗(包括过度换气、渗透性利尿和部分颅骨切除术)可作为急救措施。展开更多
文摘Carbon accumulation and spatial distribution as well as their variations in three different age(8-year-old,14-year-old and 28-year-old) stands of Taiwania flousiana plantation ecosystem were investigated in Nandan Shankou Forestry Station of Guangxi,China. The results showed that carbon content in different organs of T.flousiana ranged form 418.4 g·kg-1 to 516.4 g·kg-1,which was in order as follows:bark>branch>stem>root>leaf. The vertical distribution of carbon content within the stand was in the following order:tree layer>shrub layer>herb layer.Carbon content in the soil obviously declined with increased soil depth from 0 to 80 cm. Total carbon storage in the ecosystems was 159.37,194.21 and 278.22 t·hm-2,respectively for 8-year-old,14-yea-old and 28-yea-old stands. The tree layer in the three-age stands respectively accounted for 18.30%、28.37% and 43.59%;the shrub and herb layers for 0.14%、1.17% and 1.44%;the litter layer for 0.33%、0.89% and 1.11%;the soil for 81.23%、69.58% and 54.78% of the total storage of carbon. Carbon storage in different organs was roughly in proportion to the biomass of corresponding organ. For example,stem occupied the greatest proportion of carbon storage in the trees,up to 46.37%,and increased with the stand age while branches,leaves,bark and roots occupied more than 37.32%. The annual net productivity of the 8-year-old,14-year-old and 28-year-old T.flousiana plantation was respectively 8.93,10.82 and 12.53 t·hm-2a-1,and annual net carbon storage was respectively 4.19,5.07 and 5.93 t·hm-2a-1.
文摘脑静脉及静脉窦血栓形成(CVT)是一种罕见的疾病,占所有卒中的不到1%。由于临床症状的多样性,且亚急性或慢性发作,常被忽视甚至误诊。目前临床上CVT的治疗措施主要有:(1)抗凝,包括静脉用肝素(根据剂量调整)或皮下低分子量肝素(根据体重调整);(2)溶栓治疗;(3)对症治疗:包括抗癫治疗和降低颅高压。欧洲神经科学联盟(EFNS)专家组查阅了MEDLINE、the Cochrane Central Register of Controlled Trials(CENTRAL)和Cochrane图书馆数据库相关文献,提出了CVT治疗方案。对于目前仍缺乏证据的方面,专家组在指南中清楚的陈述了依据临床实践作出的指导意见:(1)没有抗凝禁忌证的情况下,CVT患者应该给予皮下低分子肝素或静脉使用肝素治疗。(2)CVT伴随的颅内出血不是肝素治疗的禁忌证。(3)急性期后口服抗凝药最佳持续时间目前尚不确定。如果CVT继发于短暂的危险因素,口服抗凝药可给3个月,先天性CVT和轻度遗传性血栓形成倾向的患者可给6～12个月。对于发生两次以上CVT患者及具有明显遗传性血栓形成倾向者,可考虑长期抗凝治疗。(4)目前仍缺乏有力的证据表明CVT患者需采用全身性或局部溶栓治疗。对于重症、病情不断恶化及抗凝治疗无效的患者,主张使用溶栓治疗。(5)对于严重CVT患者,颅高压明显,一般治疗效果不满意者,抗水肿治疗(包括过度换气、渗透性利尿和部分颅骨切除术)可作为急救措施。
