Biology subjects

Qiang, Y.

Publications and source records attributed to Qiang, Y..

3 recordsLinked to original sources

bioRxiv2021

A Probabilistic Approach For Registration Of Multi-Modal Spatial Transcriptomics Data

Observing the spatial characteristics of gene expression by image-based spatial transcriptomics technology allows studying gene activity across different cells and intracellular structures. We present a probabilistic approach for the registration and analysis of transcriptome images and immunostaining images. The method is based on particle filters and jointly exploits intensity information and image features. We applied our approach to synthetic data as well as real transcriptome images and immunostaining microscopy images of the mouse brain. It turns out that our approach accurately registers the multi-modal images and yields better results than a state-of-the-art method.

bioinformatics↗

bioRxiv2020

Electrical impedance detection of sickle cell vaso-occlusion in microfluidic capillary structures

Sickle cell disease (SCD) is primarily associated with episodic vaso-occlusive events. Poorly deformable sickle cells may get stuck in small blood vessels, slow down or block blood flow, leading to local hypoxia that damages tissues and organs. In this paper, we present a novel electrical impedance sensing technique for detection of the progressive occlusion by sickle cells in microfluidic capillary structures. Changes in both resistance and reactance of the sickle blood flow were observed at multiple low frequencies (< 500 kHz), upon the deoxygenation and reoxygenation processes. In contrast, no obvious impedance changes were observed in the flow of normal blood cells and sickle blood cells treated with anti-sickling agent. Accuracy of the impedance-based detection of the vaso-occlusion process was verified by microscopic observation. The results show the distinct sensing performance of sickle cell vaso-occlusion by electrical impedance, which does not require sophisticated optical microscopy or video processing. The low frequency impedance sensing can be achieved by replacing the benchtop equipment with low-cost, high precision impedance converter system, allowing for detection of sickle cell vaso-occlusion in point-of-care settings.

bioengineering↗

bioRxiv2020

A Portable Impedance Microflow Cytometer for Measuring Cellular Response to Hypoxia

This paper presents the development and testing of a low-cost, portable microflow cytometer based on electrical impedance sensing, for single cell analysis under controlled oxygen microenvironment. The cytometer system is based on an AD5933 impedance analyzer chip, a microfluidic chip, and an Arduino microcontroller operated by a custom Android application. A representative case study on human red blood cells (RBCs) affected by sickle cell disease is conducted to demonstrate the capability of the cytometry system. Equivalent circuit model of a suspending biological cell is used to interpret the electrical impedance of single flowing RBCs. In normal blood, cytoplasmic resistance and membrane capacitance do not change significantly with the change in oxygen tension. In contrast, RBCs affected by sickle cell disease show that upon hypoxia treatment, the cytoplasmic resistance decrease from 11.6 M{Omega} to 23.4 M{Omega}, and membrane capacitance decrease from 1.1 pF to 0.8 pF. Strong correlations are identified between the changes in these subcellular electrical components of single cells and the cell sickling process induced by hypoxia treatment. The representative results reported in this paper suggest that single cell electrical impedance can be used as a sensitive biophysical marker for quantifying cellular response to change in oxygen concentration. The developed flow cytometry system and the methodology can also be extended to analysis of cellular response to hypoxia in other cell types. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=124 SRC="FIGDIR/small/224006v1_ufig1.gif" ALT="Figure 1"> View larger version (38K): org.highwire.dtl.DTLVardef@147f903org.highwire.dtl.DTLVardef@2d4c35org.highwire.dtl.DTLVardef@1e63b0dorg.highwire.dtl.DTLVardef@2eeb0c_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗