[Development and Application of Automatic Analysis and Surveillance Platform for Chrimerism in Donors and Recipients after Allo-HSCT].

OBJECTIVE: To develop an automated chimeric analysis and reporting platform based on short tandem repeat (STR) and capillary electrophoresis methods for allogeneic hematopoietic stem cell transplantation (allo-HSCT) so as to improve work efficiency. METHODS: Apache, MySQL, PHP and HTML5 were used to build the database and interface. The STR locus geno typing and chimeric analysis logic and flow were set up on the basis of STR rules and capillary electrophoresis. STR genotyping and 194 times of chimeric testing data of 100 patients after allo-HSCT were used to test the platform for automatic STR locus genotyping, chimeric calculation and report generation. RESULTS: The established platform could realize the functions of STR locus customization, STR genotype determination, automatic chimeric analysis, and detection information database management, which can automatically generate an integrated report including multiple sequential chimeric results and trend graphs for the same patient and can be accessed and used simultaneously by different users through different browser interfaces. The results of automated analysis by the platform are completely consistent with that of manual analysis by experienced technicians, and the possibility of manual analysis error is reduced through automation. The time required for automatic analysis using this platform is approximately 1/6-1/5 of manual analysis. CONCLUSION: The automatic analysis platform built in this study is operation stable and reliable in analysis results, which can improve work efficiency and report connotation, thus worthing popularized and applicable.

Enhancing spin injection efficiency through half-metallic miniband conduction in a spin-filter superlattice.

We theoretically and numerically studied the band structure and spin transport of electrons subject to a superlattice structure where magnetic semiconductor layers lie between normal semiconductor layers to form periodic spin-filter tunnel barriers. In this alternately deposited superlattice structure, due to the induced periodicity of the envelope wavefunctions, there are additional allowed and forbidden energy regions established, i.e. forming minibands that are far narrower than the conventional conduction bands. The number and thickness of the stacked potential profiles can finely tune these minibands. The spin dependent potential barriers also induce spin splitting at the bottom of each miniband, which generates strongly spin-dependent miniband conduction. Most strikingly, the lowest lying miniband is 100% spin-polarized mimicking a half-metallic behavior on this conduction channel. The total transmission electron current carries thus near-perfectly polarized spin currents when the superlattice falls into suitable miniband conduction regime. This half-metallic miniband enhanced spin-filtering capability paves the way to generate highly polarized spin current without incurring exponentially increased device impedance, as usually happens when only a single spin-filter barrier is applied.