Hapln1 promotes dedifferentiation and proliferation of iPSC-derived cardiomyocytes by promoting versican-based GDF11 trapping

Hyaluronan and proteoglycan link protein 1(Hapln1)supports active cardiomyogenesis in zebrafish hearts,but its regulation in mammal cardiomyocytes is unclear.This study aimed to explore the potential regulation of Hapln1 in the dedifferentiation and proliferation of cardiomyocytes and its therapeutic value in myocardial infarction with human induced pluripotent stem cell(hiPSC)-derived cardiomyocytes(CMs)and an adult mouse model of myocardial infarction.HiPSC-CMs and adult mice with myocardial infarction were used as in vitro and in vivo models,respectively.Previous single-cell RNA sequencing data were retrieved for bioinformatic exploration.The results showed that recombinant human Hapln1(rhHapln1)promotes the proliferation of hiPSC-CMs in a dose-dependent manner.As a physical binding protein of Hapln1,versican interacted with Nodal growth differentiation factor(NODAL)and growth differentiation factor 11(GDF11).GDF11,but not NODAL,was expressed by hiPSC-CMs.GDF11 expression was unaffected by rhHapln1 treatment.However,this molecule was required for rhHapln1-mediated activation of the transforming growth factor(TGF)-β/Drosophila mothers against decapentaplegic protein(SMAD)2/3 signaling in hiPSC-CMs,which stimulates cell dedifferentiation and proliferation.Recombinant mouse Hapln1(rmHapln1)could induce cardiac regeneration in the adult mouse model of myocardial infarction.In addition,rmHapln1 induced hiPSC-CM proliferation.In conclusion,Hapln1 can stimulate the dedifferentiation and proliferation of iPSC-derived cardiomyocytes by promoting versican-based GDF11 trapping and subsequent activation of the TGF-β/SMAD2/3 signaling pathway.Hapln1 might be an effective hiPSC-CM dedifferentiation and proliferation agent and a potential reagent for repairing damaged hearts.

Effects of ECAE processing temperature on the microstructure, mechanical properties, and corrosion behavior of pure Mg

A two-step equal channel angular extrusion（ECAE） procedure was used to process pure Mg. The effects of ECAE processing temperature on the microstructure, mechanical properties, and corrosion behavior of pure Mg were studied. The results show that the average grain size of pure Mg decreases with decreasing extrusion temperature. After ECAE processing at 473 K, fine and equiaxed grains（~9 μm） are obtained. The sample processed at 473 K exhibits the excellent mechanical properties, whereas the sample processed at 633 K has the lowest corrosion rate. The improved corrosion resistance and mechanical properties of pure Mg by ECAE are ascribed to grain refinement and microstructural modification.

Research of Magnetic Coupler Array for IPT System

The advance of Inducive Power Transfer (IPT) system is capable to transfer large power across an air gap of sufficient distance, but the power level and charging area of receiver are limited by the magnetic coupler of IPT system. This paper analyses the correlative factors which effect maximum output power (Pm), it reveals Pm is inversely proportional with magnetic flux of power receiving coils. New ferrite array structure is proposed as the basic part of magnetic coupler that focusing on enhancing the equilibrium of magnetic flux distribution at charging area and increasing power transfer distance. The method of winding on ferrite array is quite flexible and the power transmission distance can be increased by changing the mode of ferrite array windings while magnetic field uniform is reduced, users can chose the suitable mode of winding for different IPT system. Finally the validity of theory analysis is tested by a 3D finite element modeling tool.

A quantitative study of airway ultrasound in predicting difficult laryngoscopy:A prospective study

Purpose:As common clinical screening tests cannot effectively predict a difficult airway,and unanticipated difficult laryngoscopy remains a challenge for physicians.We herein used ultrasound to develop some point-of-care predictors for difficult laryngoscopy.Methods:This prospective observational study included 502 patients who underwent laryngoscopy and a detailed sonographic assessment.Patients under 18 years old,or with maxillofacial deformities or fractures,limited mouth opening,limited neck movement or history of neck surgery were excluded from the study.Laryngoscopic views of all patients were scored and grouping using the modified Cormack-Lehane(CL)scoring system.The measurements acquired comprised tongue width,the longitudinal cross-sectional area of the tongue,tongue volume,the mandible-hyoid bone distance,the hyoid boneglottis distance,the mandible-hyoid bone-glottis angle,the skin-thyrohyoid membrane distance,the glottis-superior edge of the thyroid cartilage distance(DGTC),the skin-hyoid bone distance,and the epiglottis midway-skin distance.ANOVA and Chi-square were used to compare differences between groups.Logistic regression was used to identify risk factors for difficult laryngoscopy and it was visualized by receiver operating characteristic curves and nomogram.R version 3.6.3 and SPSS version 26.0 were used for statistical analyses.Results:Difficult laryngoscopy was indicated in 49 patients(CL grade III-IV)and easy laryngoscopy in 453 patients(CL grade I-II).The ultrasound-measured mandible-hyoid bone-glottis angle and DGTC significantly differed between the 2 groups(p<0.001).Difficult laryngoscopy was predicted by an area under the curve(AUC)of 0.930 with a threshold mandible-hyoid bone-glottis angle of 125.5and by an AUC of 0.722 with a threshold DGTC of 1.22 cm.The longitudinal cross-sectional area of the tongue,tongue width,tongue volume,the mandible-hyoid distance,and the hyoid-glottis distance did not significantly differ between the groups.Conclusion:Difficult laryngoscopy may be anticipated in patients in whom the mandible-hyoid boneglottis angle is smaller than 125.5or DGTC is larger than 1.22 cm.