Study on transport of small molecule rhodamine B within different layers of cartilage / 生物医学工程学杂志

The small molecule nutrients and cell growth factors required for the normal metabolism of chondrocyte mainly transport into the cartilage through free diffusion. However, the specific mass transfer law in the cartilage remains to be studied. In this study, using small molecule rhodamine B as tracer, the mass transfer models of cartilage were built under different pathways including surface pathway, lateral pathway and composite pathway. Sections of cartilage at different mass transfer times were observed by using laser confocal microscopy and the transport law of small molecules within different layers of cartilage was studied. The results showed that rhodamine B diffused into the whole cartilage layer through surface pathway within 2 h. The fluorescence intensity in the whole cartilage layer increased with the increase of mass transfer time. Compared to mass transfer of 2 h, the mean fluorescence intensity in the superficial, middle, and deep layers of cartilage increased by 1.83, 1.95, and 3.64 times, respectively, after 24 h of mass transfer. Under lateral path condition, rhodamine B was transported along the cartilage width, and the molecular transport distance increased with increasing mass transfer time. It is noted that rhodamine B could be transported to 2 mm away from cartilage side after 24 h of mass transfer. The effect of mass transfer under the composite path was better than those under the surface path and the lateral path, and especially the mass transfer in the deep layer of cartilage was improved. This study may provide a reference for the treatment and repair of cartilage injury.

Analysis of bacteria distribution characteristics in different layers of agarwood based on Hiseq sequencing / 中国中药杂志

To explore the diversity of bacterial community structure between different layers of agarwood, Hiseq(high-throughput sequencing) was used to analyze the bacterial community structure of samples from different layers of agarwood. Our results showed that 1 150 096 optimized sequences and 9 690 OTUs were obtained from 15 samples of 5 layers of agarwood, which belonged to 28 bacterial phyla, 61 classes, 110 orders, 212 families and 384 genera. Further analysis revealed that the normal layer(NL) had the lowest bacterial species richness and the smallest number of OTUs. And the total number of OTUs of the agarwood layer(AL) and NL was zero, which was quite different.At the same time, there were significant differences in bacterial community structure and species diversity between NL and the other four layers. While there were some common dominant bacterial genera in both transition layer(TL) and NL. The similarity of bacterial distribution in 4 non-NL layers was relatively high, which had four common genera, such as Acidibacter, Bradyrhizobium, Acidothemus and Sphingomonas. While Acidibacter, Bradyrhizobium and Acidothemus were the dominant bacterial genus of DA and AL, and all of these layers contained volatile oil. In addition, the Bradyrhizobium was the most abundant in agarwood layer. Our results showed that bacterial community diversity and abundance were decreasing from DL to AL, and different layers showed significant differences in bacterial enrichment. It provided the clues to investigate how bacteria participate in the formation of agarwood.