Effects of Modular Threshing and Redrying on Color Difference and Polyphenols of Tobacco Leaves

[Objectives]This study was conducted to analyze changes of color difference and polyphenols and their relationship in the process of threshing and redrying.[Methods]The change trends of color difference parameters L,a,b,H^(0),C and polyphenol contents in tobacco leaves in the middle leaf module and the Pearson correlation between them were analyzed.[Results]During threshing and redrying,L and H^(0)of tobacco showed a decreasing trend,but H^(0)changed slightly;the values of a and C showed an inverted"S"change trend,and the differences between various processes were significant;and the value of b decreased first and then increased.The content of chlorogenic acid and scopoletin decreased first,then increased,and then decreased during threshing and redrying;rutin content showed a significant decreasing trend.The value of L was in an extremely significant positive correlation with rutin content;the value of a was in an extremely significant negative correlation with chlorogenic acid content;b value was also significantly correlated with rutin;and H^(0)was in significant correlation and extremely significant correlation with rutin and total polyphenols,respectively.[Conclusions]This study provides technical support for online detection of tobacco leaf components by the color difference method and for the homogenization of threshing and redrying.

Numerical simulation and experimental research on the wheel brush sampling process of an asteroid sampler

To examine the environmental characteristics of the microgravity force and the weathered layer on an asteroid surface,a symmetric wheel brush asteroid sampler is proposed for the collection of particles on the asteroid surface.To study the influence of the wheel brush rotation speed on the sampling efficiency and the driving torque required for the wheel brush,the contact dynamics model between particles and sampling wheel brushes is established and a simulation and experimental verification of the sampling process are conducted.The parameter calibration of the sampled particles is studied first,and the calibrated particle parameters are used in the numerical simulation of the sampling process.The sampling results and the particle stream curves are obtained for the working conditions of different rotation speeds,and the effects of different parameter settings on the sampling efficiency are analyzed.In addition,a set of rotating symmetrical sampling wheel brush devices is built for the ground test,and the dynamic torque sensor is used to test the torque change of the wheel brush during the sampling process.The relationship between the speed of the wheel brush and the driving torque of the wheel brush motor is determined by comparing the simulation results with the test results.Results indicate that when the rotating speed of the wheel brush is faster,the sampling efficiency is higher,and the driving torque required for the sampling wheel brush is greater.Moreover,a numerical simulation analysis of the sampling process of the wheel brush sampler in a microgravity environment is conducted to determine the optimal speed condition,and the brushing test of the wheel brush sampler in the microgravity environment is verified with the drop tower method.This research proposes the structural optimization design and motor selection of a wheel brush asteroid sampler,which provides important reference value and engineering significance.

Single-cell Long Non-coding RNA Landscape of T Cells in Human Cancer Immunity

The development of new biomarkers or therapeutic targets for cancer immunotherapies requires deep understanding of Tcells.To date,the complete landscape and systematic characterization of long noncoding RNAs(lncRNAs)in T cells in cancer immunity are lacking.Here,by systematically analyzing full-length single-cell RNA sequencing(scRNA-seq)data of more than 20,000 libraries of T cells across three cancer types,we provided the first comprehensive catalog and the functional repertoires of lncRNAs in human T cells.Specifically,we developed a custom pipeline for de novo transcriptome assembly and obtained a novel lncRNA catalog containing 9433 genes.This increased the number of current human lncRNA catalog by 16%and nearly doubled the number of lncRNAs expressed in T cells.We found that a portion of expressed genes in single T cells were lncRNAs which had been overlooked by the majority of previous studies.Based on metacell maps constructed by the MetaCell algorithm that partitions scRNA-seq datasets into disjointed and homogenous groups of cells(metacells),154 signature lncRNA genes were identified.They were associated with effector,exhausted,and regulatory T cell states.Moreover,84 of them were functionally annotated based on the co-expression networks,indicating that lncRNAs might broadly participate in the regulation of T cell functions.Our findings provide a new point of view and resource for investigating the mechanisms of T cell regulation in cancer immunity as well as for novel cancer-immune biomarker development and cancer immunotherapies.