目的探讨空气动力学直径小于2.5μm的颗粒(PM2.5)对大鼠心血管系统的影响及PM2.5影响心脏功能的机制。方法在重庆市区采集PM2.5,选取雄性Wistar大鼠40只作为研究对象,设置正常对照组和实验染毒组[包括PM2.5低浓度组(1.0 mg/0.25 m L)、P...目的探讨空气动力学直径小于2.5μm的颗粒(PM2.5)对大鼠心血管系统的影响及PM2.5影响心脏功能的机制。方法在重庆市区采集PM2.5,选取雄性Wistar大鼠40只作为研究对象,设置正常对照组和实验染毒组[包括PM2.5低浓度组(1.0 mg/0.25 m L)、PM2.5中浓度组(3.0 mg/0.25 m L)、PM2.5高浓度组(8.0 mg/0.25 m L)]每组10只。采用气管滴注法进行PM2.5染毒,观察各组大鼠心肌组织结构、血清心肌肌钙蛋白T(cTnT)水平,同时检测心肌白介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)水平,分析机体肺灌注PM2.5后心血管系统的炎性反应和心脏功能变化。结果大鼠PM2.5染毒后,不同浓度实验染毒组大鼠心肌细胞水肿程度加深,心肌纤维呈波浪状排列,形态异常;实验染毒组大鼠血清cTnT水平明显高于正常对照组,且与PM2.5浓度呈正相关(P<0.05),PM2.5高浓度组大鼠cTnT水平明显高于PM2.5中、低浓度组,但PM2.5中、低浓度组大鼠cTnT水平无明显差异。实验染毒组大鼠心肌组织IL-6、TNF-α水平较正常对照组明显升高,差异有统计学意义(P<0.05),且与PM2.5浓度有关。结论 PM2.5引起Wistar大鼠心脏组织结构损伤,心血管系统出现明显的炎性反应,大鼠心脏功能出现损伤,提示PM2.5可能通过炎性反应损伤机体心血管系统,雾霾可能是诱发心血管疾病的重要原因。展开更多
西、甜瓜细菌性果腐病（Bacterial Fruit Blotch．简称BFB）也称为果斑病．作为近年来呈上升趋势的一种病害．对瓜类生产构成了极大威胁。果实发病后腐烂失去商品价值．瓜农损失惨重。细菌性果腐病的发生已经成为西、甜瓜生产上急需解...西、甜瓜细菌性果腐病（Bacterial Fruit Blotch．简称BFB）也称为果斑病．作为近年来呈上升趋势的一种病害．对瓜类生产构成了极大威胁。果实发病后腐烂失去商品价值．瓜农损失惨重。细菌性果腐病的发生已经成为西、甜瓜生产上急需解决的问题之一。展开更多
We demonstrate an ultrastable miniaturized transportable laser system at 1550 nm by locking it to an optical fiber delay line[FDL].To achieve optimized long-term frequency stability,the FDL was placed into a vacuum ch...We demonstrate an ultrastable miniaturized transportable laser system at 1550 nm by locking it to an optical fiber delay line[FDL].To achieve optimized long-term frequency stability,the FDL was placed into a vacuum chamber with a five-layer thermal shield,and a delicate two-stage active temperature stabilization,an optical power stabilization,and an RF power stabilization were applied in the system.A fractional frequency stability of better than 3.2×10^[-15]at 1 s averaging time and1.1×10^[-14]at 1000 s averaging time was achieved,which is the best long-term frequency stability of an all-fiber-based ultrastable laser observed to date.展开更多
文摘目的探讨空气动力学直径小于2.5μm的颗粒(PM2.5)对大鼠心血管系统的影响及PM2.5影响心脏功能的机制。方法在重庆市区采集PM2.5,选取雄性Wistar大鼠40只作为研究对象,设置正常对照组和实验染毒组[包括PM2.5低浓度组(1.0 mg/0.25 m L)、PM2.5中浓度组(3.0 mg/0.25 m L)、PM2.5高浓度组(8.0 mg/0.25 m L)]每组10只。采用气管滴注法进行PM2.5染毒,观察各组大鼠心肌组织结构、血清心肌肌钙蛋白T(cTnT)水平,同时检测心肌白介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)水平,分析机体肺灌注PM2.5后心血管系统的炎性反应和心脏功能变化。结果大鼠PM2.5染毒后,不同浓度实验染毒组大鼠心肌细胞水肿程度加深,心肌纤维呈波浪状排列,形态异常;实验染毒组大鼠血清cTnT水平明显高于正常对照组,且与PM2.5浓度呈正相关(P<0.05),PM2.5高浓度组大鼠cTnT水平明显高于PM2.5中、低浓度组,但PM2.5中、低浓度组大鼠cTnT水平无明显差异。实验染毒组大鼠心肌组织IL-6、TNF-α水平较正常对照组明显升高,差异有统计学意义(P<0.05),且与PM2.5浓度有关。结论 PM2.5引起Wistar大鼠心脏组织结构损伤,心血管系统出现明显的炎性反应,大鼠心脏功能出现损伤,提示PM2.5可能通过炎性反应损伤机体心血管系统,雾霾可能是诱发心血管疾病的重要原因。
基金supported by the Special Foundation for State Major Basic Research Program of China(Nos.2021YFC2201803 and 2021YFC2201904)。
文摘We demonstrate an ultrastable miniaturized transportable laser system at 1550 nm by locking it to an optical fiber delay line[FDL].To achieve optimized long-term frequency stability,the FDL was placed into a vacuum chamber with a five-layer thermal shield,and a delicate two-stage active temperature stabilization,an optical power stabilization,and an RF power stabilization were applied in the system.A fractional frequency stability of better than 3.2×10^[-15]at 1 s averaging time and1.1×10^[-14]at 1000 s averaging time was achieved,which is the best long-term frequency stability of an all-fiber-based ultrastable laser observed to date.
