用于1型糖尿病细胞治疗的胰岛低温保存进展

近年来,1型糖尿病细胞治疗技术发展迅速,但供体胰岛的缺乏及供体与受体在时间和空间上的不匹配限制了其在临床上的应用.低温保存技术可以解决该限制,但经传统低温保存方法保存的胰岛存活率和功能性均较差,难以达到临床应用的标准.本文对胰岛低温保存原理及低温保存过程中造成胰岛损伤的因素进行了分类归纳,从冰晶损伤抑制、保护剂损伤抑制...     

多重油脂微胶囊乳液喷雾干燥粉工艺及其理化性质

为提高膳食中脂肪酸组成多样性，本研究以多重脂肪酸组成的复合油脂（玉米油、黄油、椰子油、藻油）为芯材，麦芽糊精、乳清蛋白浓缩物、酪蛋白酸钠为主要壁材，通过微射流耦合食品乳化剂制得O/W型均匀乳液，经喷雾干燥制得粉末微胶囊，利用单因素实验结合响应面分析包埋率影响因素，优化了最佳制备工艺: 进风温度170 ℃、均质压力31 MPa、乳化剂添加量0.3%，该产品的油脂包埋率高达85.75%。红外光谱（FTIR）分析证实油脂通过微胶囊得到了较好包埋，扫描电镜（SEM）图像显示产品表面虽略有凹陷但是结构致密完整。实验发现产品粉末的复原乳液液滴平均粒径为241.8 nm，zeta电位为-33.1 mV，显示该产品具有良好的复溶性与稳定性；激光共聚焦扫描显微镜（CLSM）发现油脂完整包埋且可均匀悬浮，显示微胶囊复原乳中油脂的保护效果好。     

Design,Synthesis, and Characterization of a Novel Fluoroprobe for Live Human Islet Cell Imaging of Serotonin 5-HT1A Receptor

Mounting evidence suggests that the serotonin system serves in signal transmission to regulate insulin secretion in pancreatic islets of Langerhans. Among the 5-HT receptor subtype found in pancreatic islets, serotonin receptor 1A (5-HT_1A) demonstrates a unique ability to inhibit β-cell insulin secretion. We report the design, synthesis, and characterization of two novel fluorescent probes for the 5-HT_1A receptor. The compounds were prepared by conjugating the scaffold of the 5-HT_1A receptor agonist 8-OH-DPAT with two fluorophores suitable for live-cell imaging. Compound 5a {5-(dimethylamino)-N-[5-[(8-hydroxy-1,2,3,4-tetrahydronaphthalen-2-yl)(propyl)amino]pentyl]naphtalen-1-sulfonammide} showed high affinity for the 5-HT_1A receptor (K_i=1.8 nM). Fluoroprobe 5a was able to label the 5-HT_1A receptor in pancreatic islet cell cultures in a selective manner, as the fluorescence emission was significantly attenuated by co-administration of the 5-HT_1A receptor antagonist WAY-100635. Thus, fluoroprobe 5a showed useful properties to further characterize this unique receptor‘s role.     

Effects of starting powder on microstructure and thermal conductivity of pressureless-sintered fully ceramic microencapsulated fuels

The effects of the starting SiC powder (α or β) with the addition of 5.67 wt% AlN–Y₂O₃–CeO₂–MgO additives on the residual porosity and thermal conductivity of fully ceramic microencapsulated (FCM) fuels were investigated. FCM fuels containing ～41 vol% and ～37 vol% tristructural isotropic (TRISO) particles could be sintered at 1870 °C using α-SiC and β-SiC powders, respectively, via a pressureless sintering route. The residual porosities of the SiC matrices in the FCM fuels prepared using the α-SiC and β-SiC powders were 1.1% and 2.3%, respectively. The thermal conductivities of FCM pellets with ～41 vol% and ～37 vol% TRISO particles (prepared using the α-SiC and β-SiC powders, respectively) were 59 and 41 Wm^?1K^?1, respectively. The lower porosity and higher thermal conductivity of FCM fuels prepared using the α-SiC powder were attributed to the higher sinterability of the α-SiC powder than that of the β-SiC powder.