肌肉生长抑制素在慢性阻塞性肺疾病合并肺动脉高压患者血浆中的表达及意义

目的研究肌肉生长抑制素在慢性阻塞性肺疾病(COPD)合并肺动脉高压(PH)患者中的表达水平。分析肌肉生长抑制素与COPD合并PH的关系。方法 59例COPD合并PH患者和166例COPD无PH患者,检测肌肉生长抑制素和脑钠肽(BNP)水平。心脏彩超评估右心室功能和形态,心脏多普勒检测肺动脉压力(SPAP),SPAP≥40 mm Hg被确定为PH,三尖瓣瓣环收缩期偏移(TAPSE)≤16 mm为右心功能不全。检查肺功能、动脉血气、6 min步行距离。结果收录225例COPD患者,COPD合并PH患者占26.2%(59/225);COPD合并PH组肌肉生长抑制素和BNP水平高于COPD无PH组,两组肌肉生长抑制素水平分别是中位数16.4和12.8 ng/L,差异有统计学意义(P<0.05);BNP水平分别是(147.87±42.98)和(114.61±53.47)pg/ml,差异有统计学意义(P<0.05);相关分析:BNP和肌肉生长抑制素呈正相关;肌肉生长抑制素和SPAP呈正相关;肌肉生长抑制素与TAPSE和右室心肌性能指标相关(P<0.05);BNP只与SPAP呈正相关(P<0.05)。结论 COPD合并PH患者,血浆肌肉生长抑制素水平增加,与血浆BNP水平比较,在评估右心功能及肺动脉高压方面,肌肉生长抑制素水平有更强的相关性。肌肉生长抑制素可能优于BNP对COPD合并肺动脉高压的早期诊断。

Study on Micron Porous Copper Prepared by Physical Vacuum Dealloying

Porous copper was prepared successfully by physical vacuum dealloying method using the CuZn alloy pre- cursors （Cu30Zn70, Cu40Zn60 and Cu50Zn50 alloys）. The micron porous copper showed a three-dimensional continuous porous structure with 1-5 μm pore size. With the increase of the Zn content in the CuZn alloy, the pore structure of the porous copper was more uniform and ordered. Temperature was the key factor for physical dealloying, and the optimized temperature was 500 ℃ for the CuZn alloy. The pores would fuse and disappear when the temperature was over 500 ℃. Physical vacuum dealloying was an effective preparation method for porous copper, which can be used to prepare other porous metals based on the sublimation and the Kirkendall effect.