智能手机成瘾可预测青少年的物质主义倾向

“宁在宝马车里哭,不在自行车上笑”等拜金主义现象常常成为引爆朋友圈和微博的热点话题。有研究指出,当代青少年的物质主义水平正在逐年上升。同时,以往研究发现,高物质主义往往伴随着更低的幸福感,以及更差的环保意识、金钱管理能力和消费习惯等。由此,全面地发掘青少年物质主义倾向产生的原因具有重要的现实意义和理论价值。

Studies on Production of Biodiesel by Esterification of Fatty Acids by a Lipase Preparation from Candida sp. 99-125

A self-made lipase preparation from Candida sp. 99-125 was used for the production of biodiesel through enzymatic esterification of fatty acids. The crude lipase powder and fermentation broth were immobilized on a cheap fiber cloth carrier. The conditions of lipase-catalyzed esterification between long-chain fatty acids and methanol in a solvent system were investigated in detail, including the temperature, pH value, substrate concentration, solvent, absorbent agent, enzyme dosage and purity, immobilization method, the mode of addition of substrate. The results show that reaction temperature, pH of lipase micro-environment, substrate concentration, enzyme dosage and purity affect the esterification strongly. Several new methods and enzymatic procedures for improving the enzymatic reaction involving the process cost are also discussed, such as fossil diesel fuel as reaction solvent, immobilization method, multi-step gradient addition of methanol. The esterification degree of 92.8% was obtained with oleic acid and methanol under the optimal reaction condition after 12.5 h reaction time. The half-life of the immobilized lipase preparation from crude free lipase powder for esterification was 15 days.

婴幼儿动脉导管结扎不置胸腔引流的治疗体会

目的：婴幼儿PDA术后不置胸腔引流的治疗体会。方法：经左腋下第四肋小切口，4～6cm，常规结扎动脉导管，关胸时排尽余气，不置闭式引流。结果：无病例死亡，术后杂音消失，仅1例少量积血，其余病例术后无积液积气。2例喉返神经损伤，3月后恢复。结论：创伤小痛苦轻，减少手术疤痕；有利于患儿术后护理和治疗，有利于早期咳嗽和下床活动，促使肺复张，减少住院时间，降低了患儿恐惧心理。该法适应于婴幼儿管型PDA。复杂婴幼儿PDA及成人PDA慎用。