玉米二次精胚回收工艺试验小结

"玉米干式提胚新工艺--二次精胚回收工艺”,平均精胚提取率可达13.1%,纯胚提取率平均达8.95%,淀粉损失率约1.48%.新工艺结果表明,精胚提取率最佳值为12.7%,纯胚提取率为8.67%.     

Developmental potency of cultured pineal cells: an approach to pineal developmental biology

The pineal organ is still an enigma in regard to its developmental and phylogenetic origin. Little is known of the mechanism involved in determination and differentiation of pineal cells and virtually no studies have been done on the induction and tissue interactions during pinealogenesis. Interest is also centered on the evolutional transformation in structure and function, which may be related to the developmental alterations in pineal morphogenesis between the lower and higher vertebrate species. For developmental studies, avian embryos have great advantages for various experimental manipulations, such as cell and organ culture, surgical operation, and in situ transfection of developmental genes. The present review describes our cell culture studies, which have been done on developing rat and quail pineal organs, in order to elucidate the developmental potency of pineal cells and the regulatory mechanism involved in the phenotypic expression of cell properties. A number of phenotypes including numerous neuron-specific substances are shown immunohistochemically to be expressed only under culture conditions, and not observed in the mature pineal organ. As development proceeds, some of the potencies for cell differentiation are lost; hence, in the mature pineal organs most neuronal phenotypes are not expressed. Numerous factors were discovered which affect phenotypic expression of cultured pineal cells in a cell-type-specific manner. These findings, together with immunohistochemical observations on developing pineal organs, reveal that the developing pineal organ is a unique and useful model system for developmental neurobiology and that cell culture techniques offer a powerful tool for the understanding of development and cell differentiation of this particular organ.     

一种偏心轮的加工方法

偏心轮是由电机、减速机的圆周运动转变成活塞的直线运动过程中的关键件。从简单的机床入手，根据偏心轮的工作原理及结构特点，提出偏心轮的加工方法及注意事项。     

玉米谷胱甘肽提取技术的研究

以淀粉加工副产物玉米胚为原料,经过超临界流体萃取脱脂及微波破壁处理后,采用热水浸提法提取谷胱甘肽,通过正交试验确定超临界流体萃取脱脂工艺条件为压力25MPa,萃取温度40℃,时间120min,CO2流量20L/h。在此条件下脂类物质萃取率57.03%,玉米胚粕含脂率0.72%。最佳热水浸提工艺条件为固液比1:20(g/ml)、浸提温度90℃、浸提液pH值3.0、浸提时间20min。在此条件下谷胱甘肽提取量为104mg/100g玉米胚。     

恐龙坯胎的中子活化分析研究

经揭露和中子活化分析,证实了恐龙蛋CT扫描所查出的胚胎形态是真实可靠的。各属种恐龙蛋及其内外物质经中子活化分析,证明白垩纪晚期河南西峡和江西赣州两地区都为陆相环境;恐龙蛋蛋壳的渗透性好,细菌和病毒易于侵入;各属种恐龙蛋蛋内外物质富含放射性元素和受外星球撞击与火山喷发等众多原因,致使绝大多数恐龙蛋无法正常孵化和造成绝大部分恐龙的绝灭。     

Investigation of PRDM10 and PRDM13 Expression in Developing Mouse Embryos by an Optimized PACT-Based Embryo Clearing Method

Recent developments in tissue clearing methods have significantly advanced the three-dimensional analysis of biological structures in whole, intact tissue, providing a greater understanding of spatial relationships and biological circuits. Nonetheless, studies have reported issues with maintaining structural integrity and preventing tissue disintegration, limiting the wide application of these techniques to fragile tissues such as developing embryos. Here, we present an optimized passive tissue clearing technique (PACT)-based embryo clearing method, initial embedding PACT (IMPACT)-Basic, that improves tissue rigidity without compromising optical transparency. We also present IMPACT-Advance, which is specifically optimized for thin slices of mouse embryos past E13.5. We demonstrate proof-of-concept by investigating the expression of two relatively understudied PR domain (PRDM) proteins, PRDM10 and PRDM13, in intact cleared mouse embryos at various stages of development. We observed strong PRDM10 and PRDM13 expression in the developing nervous system and skeletal cartilage, suggesting a functional role for these proteins in these tissues throughout embryogenesis.     

Automated standardization of images of Drosophila embryos

Modeling expression patterns of Drosophila, in space and time, plays a critical role to understand the development of multicellular organisms. In confocal microscopy, to produce precise quantitative data it is frequently necessary to process and analyze large amounts of digital images. Automatic preprocessing is a crucial step in this scenario, essential to standardize significant features such as orientation, size, position, direction, lighting condition and texture of embryo images. Even though a lot of efforts have been made, a robust embryo standardization strategy is still needed. In this paper, we propose the method Embrystandar. It is designed to remove background artifacts and standardize the direction and orientation of a Drosophila embryo through a sequence of automatic operations. To test its potential for large-scale image processing, Embrystandar was applied in different databases. It showed to be robust and precise, reaching more than 90% success rate.     

Blood flow through the embryonic heart outflow tract during cardiac looping in HH13–HH18 chicken embryos

Blood flow is inherently linked to embryonic cardiac development, as haemodynamic forces exerted by flow stimulate mechanotransduction mechanisms that modulate cardiac growth and remodelling. This study evaluated blood flow in the embryonic heart outflow tract (OFT) during normal development at each stage between HH13 and HH18 in chicken embryos, in order to characterize changes in haemodynamic conditions during critical cardiac looping transformations. Two-dimensional optical coherence tomography was used to simultaneously acquire both structural and Doppler flow images, in order to extract blood flow velocity and structural information and estimate haemodynamic measures. From HH13 to HH18, peak blood flow rate increased by 2.4-fold and stroke volume increased by 2.1-fold. Wall shear rate (WSR) and lumen diameter data suggest that changes in blood flow during HH13–HH18 may induce a shear-mediated vasodilation response in the OFT. Embryo-specific four-dimensional computational fluid dynamics modelling at HH13 and HH18 complemented experimental observations and indicated heterogeneous WSR distributions over the OFT. Characterizing changes in haemodynamics during cardiac looping will help us better understand the way normal blood flow impacts proper cardiac development.     

利用巨胚米和黑米研制婴儿营养米粉

以巨胚米和黑米为主要原料，通过挤压膨化工艺，适当添加铁、锌、钙和α-乳白蛋白，研制出适合婴儿生理特点的婴儿营养米粉，并对巨胚米和黑米在婴儿营养米粉中的应用进行了讨论。