We have developed a method where, after glutaraldehyde fixation, human hair shafts and insect cuticles are treated with ammonium thioglycolate (ATG) to improve ultrastructural staining. Conventional transmission elect...We have developed a method where, after glutaraldehyde fixation, human hair shafts and insect cuticles are treated with ammonium thioglycolate (ATG) to improve ultrastructural staining. Conventional transmission electron microscopic (TEM) preparations do not distinguish the A-layer and the exocuticles of hair shafts. However, after ATG treatment, the A-layer appears in higher contrast. ATG treatment has also been used to observe the fibrillar structure in the cortex. In the cuticle of beetles, the epicuticle is stained by ATG. Although the human hair shaft (keratin) and insect cuticle (chitin) are composed of different materials, both can be reduced by the ATG solution. The ammonium in the ATG solution reacts with hair shafts and insect cuticles, causing a reduction of swelled cuticles. Therefore, ATG not only stains, but also reduces human hair shafts and the cuticles of beetles.展开更多
Producing 2-ethyl-1-hexyl thioglycolate(ETE)via esterification reaction with thioglycolic acid(TGA)aqueous solution as raw material by reactive-separation coupling technology is a promising process intensification met...Producing 2-ethyl-1-hexyl thioglycolate(ETE)via esterification reaction with thioglycolic acid(TGA)aqueous solution as raw material by reactive-separation coupling technology is a promising process intensification method.To choose suitable reactive-separation coupling strategy,the kinetic studies of the esterification of TGA with 2-ethyl-1-hexanol(EHL)were carried out in a batch system.The commercial ion exchange resin was employed as an eco-friendly catalyst.The effects of temperature,catalyst concentration and molar ratio were determined.It was interesting to observe that the equilibrium conversion of TGA increased with the increase of catalyst mass fraction due to the adsorption of product water onto resin surface.The activity-based pseudo-homogeneous(PH),Eley-Rideal(ER)and Langmuir-Hinshelwood-Ho ugen-Watson(LHHW)models were used to fit the kinetics data of the resin-catalyzed reaction.The models of ER and LHHW performed better than the PH model.The kinetics of the TGA-self-catalyzed reaction was also determined.An activity-based homogeneous kinetics model could well describe this self-catalyzed reaction.These results would be meaningful to the selection and design of an appropriate reactionseparation strategy for the production of ETE,to realize the process intensification.展开更多
以巯基乙酸异辛酯和甲基氯化锡为原料合成了甲基硫醇锡,考察了物料配比、反应温度、反应时间及碳酸钠加入速度对反应的影响。确定甲基硫醇锡的最佳合成工艺条件为:m(甲基氯化锡)∶m(巯基乙酸异辛酯)=0.50∶1,反应温度40℃,反应时间1.0 h...以巯基乙酸异辛酯和甲基氯化锡为原料合成了甲基硫醇锡,考察了物料配比、反应温度、反应时间及碳酸钠加入速度对反应的影响。确定甲基硫醇锡的最佳合成工艺条件为:m(甲基氯化锡)∶m(巯基乙酸异辛酯)=0.50∶1,反应温度40℃,反应时间1.0 h,碳酸钠加入速度前30 min 30 g.h-1、后30 min 10 g.h-1。在此条件下,产品收率达83.79%,各项质量指标均优于市售同类产品。展开更多
文摘We have developed a method where, after glutaraldehyde fixation, human hair shafts and insect cuticles are treated with ammonium thioglycolate (ATG) to improve ultrastructural staining. Conventional transmission electron microscopic (TEM) preparations do not distinguish the A-layer and the exocuticles of hair shafts. However, after ATG treatment, the A-layer appears in higher contrast. ATG treatment has also been used to observe the fibrillar structure in the cortex. In the cuticle of beetles, the epicuticle is stained by ATG. Although the human hair shaft (keratin) and insect cuticle (chitin) are composed of different materials, both can be reduced by the ATG solution. The ammonium in the ATG solution reacts with hair shafts and insect cuticles, causing a reduction of swelled cuticles. Therefore, ATG not only stains, but also reduces human hair shafts and the cuticles of beetles.
基金the financial support for this work from the National Natural Science Foundation of China(No.21706034)the Guiding Project of Fujian Province(No.2018H0016)+1 种基金the Open Foundation of State Key Laboratory of Chemical Engineering(No.SKL-ChE-18B02)the Integration of Industry,Education and Research of Fujian Province(No.2018Y4008).
文摘Producing 2-ethyl-1-hexyl thioglycolate(ETE)via esterification reaction with thioglycolic acid(TGA)aqueous solution as raw material by reactive-separation coupling technology is a promising process intensification method.To choose suitable reactive-separation coupling strategy,the kinetic studies of the esterification of TGA with 2-ethyl-1-hexanol(EHL)were carried out in a batch system.The commercial ion exchange resin was employed as an eco-friendly catalyst.The effects of temperature,catalyst concentration and molar ratio were determined.It was interesting to observe that the equilibrium conversion of TGA increased with the increase of catalyst mass fraction due to the adsorption of product water onto resin surface.The activity-based pseudo-homogeneous(PH),Eley-Rideal(ER)and Langmuir-Hinshelwood-Ho ugen-Watson(LHHW)models were used to fit the kinetics data of the resin-catalyzed reaction.The models of ER and LHHW performed better than the PH model.The kinetics of the TGA-self-catalyzed reaction was also determined.An activity-based homogeneous kinetics model could well describe this self-catalyzed reaction.These results would be meaningful to the selection and design of an appropriate reactionseparation strategy for the production of ETE,to realize the process intensification.
文摘以巯基乙酸异辛酯和甲基氯化锡为原料合成了甲基硫醇锡,考察了物料配比、反应温度、反应时间及碳酸钠加入速度对反应的影响。确定甲基硫醇锡的最佳合成工艺条件为:m(甲基氯化锡)∶m(巯基乙酸异辛酯)=0.50∶1,反应温度40℃,反应时间1.0 h,碳酸钠加入速度前30 min 30 g.h-1、后30 min 10 g.h-1。在此条件下,产品收率达83.79%,各项质量指标均优于市售同类产品。
