Microfluidic thermotaxic selection of highlymotile sperm and in vitro fertilization

The selection of the most motile and functionally competent sperm is an essential basis for in vitro fertilization(IVF)and normal embryonic development.Widely adopted clinical approaches for sperm sample processing intensely rely on centrifugation and wash steps that may induce mechanical damage and oxidative stress to sperm.Although a few microfluidic sperm sorting devices may avoid these adverse effects by exploiting intrinsic guidance mechanisms of sperm swimming,none of these approaches have been fully validated by clinical-grade assessment criteria.In this study,a microfluidic sperm sorting device that enables the selection of highly motile and functional sperm via their intrinsic thermotaxis is presented.Bioinspired by the temperature microenvironment in the fallopian tube during natural sperm selection,a microfluidic device with controllable temperature gradients along the sperm separation channel was designed and fabricated.This study investigated the optimal temperature conditions for human sperm selection and fully characterized thermotaxis-selected sperm with 45 human sperm samples.Results indicated that a temperature range of 35–36.5℃along the separation channel significantly improves human sperm motility rate((85.25±6.28)%vs.(60.72±1.37)%;P=0.0484),increases normal sperm morphology rate((16.42±1.43)%vs.(12.55±0.88)%;P<0.0001),and reduces DNA fragmentation((7.44±0.79)%vs.(10.36±0.72)%;P=0.0485)compared to the nonthermotaxis group.Sperm thermotaxis is species-specific,and selected mouse sperm displayed the highest motility in response to a temperature range of 36–37.5℃ along the separation channel.Furthermore,IVF experiments indicated that the selected sperm permitted an increased fertilization rate and improved embryonic development from zygote to blastocyst.This microfluidic thermotaxic selection approach will be translated into clinical practice to improve the IVF success rate for patients with oligozoospermia and asthenozoospermia.

单眼视力下降对双眼对比敏感度的影响

目的:研究单眼视力下降时双眼对比敏感度(CS)的变化规律,初步探讨单眼视力下降对双眼视功能及双眼相互作用的影响,并且探讨其在司法鉴定中的运用价值。方法:实验研究。于2016年3月至2017年8月选择司法鉴定科学研究院志愿者46例(男24例,女22例)。单眼矫正视力或裸眼视力均达4.9以上,主导眼前放置试验透镜,用插片法诱导实验性单眼视力不同程度下降。分别测试其左眼、右眼及双眼的视力、CS,计算对比敏感度双眼总和比(BSR)。数据进行球形检验、方差分析及秩和检验。结果:单眼视力下降可引起双眼视力一定程度下降,但是双眼视力仍优于单眼。当视力下降至轻度损害水平时,全频段正常倒“U”形CS曲线形态已破坏,且相较低空间频率而言,中、高空间频率时CS下降程度更为明显;在高频区且两眼视力均正常时,出现最大的BSR,为1.48。当单眼视力逐渐下降时,出现双眼平均及抑制(BSR<1)。提示双眼相互作用的形式存在一定程度的容忍性及空间依赖性。结论:单眼视力下降对双眼CS、双眼相互作用的形式及程度具有一定程度的影响。运用双眼CS检测,能够反映单眼视力的损害程度,具有临床及司法鉴定运用价值。

创伤弧菌溶细胞素噬菌体单链抗体库的构建

目的为获得高特异性创伤弧菌溶细胞素单链抗体,利用噬菌体展示技术建立鼠源性噬菌体单链抗体库。方法用溶细胞素蛋白免疫BALB/c小鼠后,取脾脏提取总RNA,逆转录获得cDNA。以cDNA为模板扩增出抗体的轻链和重链可变区基因片段,通过OE-PCR技术拼接成完整scFv基因片段,构建重组噬菌粒pComb3XSS-scFv,电转化到大肠杆菌XL1-Blue构建噬菌体单链抗体库。结果构建鼠源性的噬菌体单链抗体文库其重组率为78%,库容量为3×10^(8)。结论成功构建鼠源单链抗体噬菌体文库,为创伤弧菌感染的快速诊断奠定基础。