Measurement of Charge Distributions in a Bubbling Fluidized Bed Using Wire-Mesh Electrostatic Sensors

In order to maintain safe and efficient operation of a fluidized bed, electrostatic charges in the bed should be monitored continuously. Electrostatic sensors with wire-mesh electrodes are introduced in this paper to measure the charge distribution in the cross section of the fluidized bed. A Finite Element Model is built to investigate the sensing characteristics of the wire-mesh sensors. In comparison with conventional electrostatic sensors, wire-mesh sensors have higher and more uniform sensitivity distribution. Based on the induced charges on the electrodes and the sensitivity distributions of the sensors, the charge distribution in the cross section of the fluidized bed is reconstructed. However, it is difficult to directly measure the induced charges on the electrodes. A charge calibration process is conducted to establish the relationship between the induced charge on the electrode and the electrostatic signal. Experimental studies of charge distribution measurement were conducted on a lab-scale bubbling fluidized bed. The electrostatic signals from the wire-mesh sensors in the dense phase and splash regions of the bed for different fluidization air flow rates were obtained. Based on the results obtained from the charge calibration process, the estimated induced charges on the electrodes are calculated from the Root Mean Square values of the electrostatic signals. The characteristics of the induced charges on the electrodes and the charge distribution in the cross section under different flow conditions are investigated, which proves that wire-mesh electrostatic sensors are able to measure the charge distribution in the bubbling fluidized bed

miR-212/132-Enriched Extracellular Vesicles Promote Differentiation of Induced Pluripotent Stem Cells Into Pancreatic Beta Cells

Pancreatic beta cell transplantation is the ideal method for treatment of type 1 diabetes mellitus (T1DM), and the generation of beta cells from induced pluripotent stem cells (iPSCs) of patients is a promising strategy. In this study, we improved a previous strategy to produce beta cells using extracellular vesicles (EVs) derived from mature beta cells and differentiated beta cells from iPSCs (i-Beta cells), which secreted insulin under glucose stimulation in vitro and ameliorated hyperglycemia in vivo. Mechanistic analyses revealed that EV-carried microRNA (miR)-212/132 (EV-miR-212/132) directly bound to the 3′ UTR of FBW7 to prevent its translation and FBW7 combined with NGN3 to accelerate its proteasomal degradation. EV-miR-212/132 stabilized NGN3 expression to promote differentiation of endocrine cells from induced iPSCs. Moreover, NGN3 bound to PDX1 to enhance transcription of endogenous miR-212/132 and formed a positive regulatory circuit that maintained the functions of mature pancreatic beta cells.ConclusionThis study describes a novel approach for beta cell production and supports the use of iPSCs for cell replacement therapy of T1DM

Isolation of a Pluripotent Neural Stem Cell from the Embryonic Bovine Brain

We recently isolated stem cells derived from the brain of a bovine fetus, utilizing a particular mechanical separation method. After improving our experimental conditions, we obtained neural stem cells using an optimized culture medium system. The cells were expanded, established in continuous cell culture and used for immunofluorescence cytochemistry. RT-PCR showed that embryonic neural stem cells (NSCs) not only expresses the protein Sox2, Nestin but also Pax6, Musashi proteins and were differentiated into the three classical neuronal phenotypes (neurons, astrocytes, and oligodendrocytes)

Construction and Preliminary Characterization Analysis of Wuzhishan Miniature Pig Bacterial Artificial Chromosome Library with Approximately 8-Fold Genome Equivalent Coverage

Bacterial artificial chromosome (BAC) libraries have been invaluable tools for the genome-wide genetic dissection of complex organisms. Here, we report the construction and characterization of a high-redundancy BAC library from a very valuable pig breed in China, Wuzhishan miniature pig (Sus scrofa), using its blood cells and fibroblasts, respectively. The library contains approximately 153,600 clones ordered in 40 superpools of 10 × 384-deep well microplates. The average insert size of BAC clones was estimated to be 152.3 kb, representing approximately 7.68 genome equivalents of the porcine haploid genome and a 99.93% statistical probability of obtaining at least one clone containing a unique DNA sequence in the library. 19 pairs of microsatellite marker primers covering porcine chromosomes were used for screening the BAC library, which showed that each of these markers was positive in the library; the positive clone number was 2 to 9, and the average number was 7.89, which was consistent with 7.68-fold coverage of the porcine genome. And there were no significant differences of genomic BAC library from blood cells and fibroblast cells. Therefore, we identified 19 microsatellite markers that could potentially be used as genetic markers. As a result, this BAC library will serve as a valuable resource for gene identification, physical mapping, and comparative genomics and large-scale genome sequencing in the porcine