Objective To investigate the potassium currents of the cardiac pacemaking cells induced and differentiated from rat mesenchymal stem cells (MSCs) modified by HCN4 gene. Methods Identified cardiac pacemaking cells were adopted as the experiment group, and the sinoatrial node cells of original infant rat cultured in the same period were regarded as the control group. Whole cell patch was used to measure the action potential of the pacemaking cells and sinoatrial node cells. Results Action potential of automatic depolarization at dilatation was recorded in both the differentiated cardiac pacemaking cells and sinoatrial node cells. There was no significant difference on amplitudes of resting potential, amplitudes and cycle of action potential [(-50?2.8) vs (-55?5.5),(-60?2.5) vs (-65?2.5),(240?57) ms vs (250?60) ms], but the field potential was much lower in cardiac pacemaking cells than the control group[(-30?2.5) vs (-55?5.5),P

Additive manufacturing (AM) is a collection of technologies based on the layer-by-layer manufacturing. Characterized by its direct manufacturing and rapidity, it has been regarded by the Economist Journal as one of the key techniques which will trigger the third industry reformation. The present article, beginning with a brief introduction of the history of AM and the process of its major technologies, focuses on the advantages and disadvantages and medical applications of the technique.
Medicine ; Printing, Three-Dimensional

Objective:Hepatocellular carcinoma(HCC)patients at the same stage exhibit different prognosis,and the underlying molecular mechanism remains unclear.This study aims to identify the key genes impacting the prognosis of HCC patients. Methods:Differentially expressed gene analyses were performed between HCC samples and normal ones,and between patients with long overall survival(OS)and those with short OS,in TCGA-LIHC and GSE14520 datasets.The Kaplan-Meier method with log-rank test was used to evaluate the role of secreted phosphoprotein 2(SPP2)in the prognosis of HCC patients.Gene set enrichment analysis(GSEA)was used to understand the difference of enriched signaling pathways between SPP2-stratified HCC subgroups.Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)analyses were performed to predict the potential functional pathways in which SPP2 might participate. Results:SPP2 was significantly down-regulated in tumors when compared with normal tissues,or in tumor samples with short OS when compared with those with long OS[fold change(FC)>2 and false discovery rate(FDR)<0.05].Low expression of SPP2 was associated with worse clinicopathological features like vascular invasion(P=1.6e-05),poor cancer status(with tumor,P=0.021),advanced T stage(T3 or T4,P=4.5e-04),advanced TNM stage(stage Ⅲ or Ⅳ,P=3.1e-04),and with unfavorable prognosis(shorter OS,P= 0.002).Gene enrichment analyses revealed that SPP2 might involve in the metabolic homeostasis of HCC and in the development of liver fibrosis and cirrhosis. Conclusion:SPP2 might inhibit the development of liver fibrosis and cirrhosis and the tumorigenesis of HCC,and analogs of SPP2 might be potential drugs in the prevention of these diseases.

Objective:To establish and evaluate a new real-time quality control method that can identify the random errors by using the backpropagation neural network (BPNN) algorithm and taking blood glucose test as an example.Methods:A total of 219 000 blood glucose results measured by Siemens advia 2 400 analytical system from January 2019 to July 2020 and derived from Laboratory Information System of Beijing Chaoyang Hospital Laboratory Department was regarded as the unbiased data of our study. Six deviations with different sizes were introduced to generate the corresponding biased data. With each biased data, BPNN and MovSD algorithms were used and tested, and then evaluated by traceability method and clinical method.Results:For BPNN algorithm, the block size was pre-set to 10 and the false-positive rate in all biases was within 0.1%. For MovSD, however, the optimal block size and exclusive limit were 150 and 10% separately and its false-positive rate in all biases was 0.38%, which was 0.28% higher than BPNN. Especially, for the least two error factors of 0.5 and 1, all the random errors were not detected by MovSD; for the error factor larger than 1, random errors could be detected by MovSD but the MNPed was higher than that of BPNN under all deviations. The difference was up to 91.67 times. 460 000 reference data were produced by traceability procedure. The uncertainty of BPNN algorithm evaluated by these reference data was only 0.078%.Conclusion:A real-time quality control method based on BPNN algorithm was successfully established to identify random errors in analytical phase, which was more efficient than MovSD method and provided a new idea and method for the identification of random errors in clinical practice.