Numerical Simulation of Bidirectional Flow and Solid Coupling of Single Pile and Single Row Pile Column and Wave

The three-dimensional model of the wave and pile structure was established by using Ansysworkbench software. The bidirectional fluid-structure interaction between the pile and wave was simulated by using Stokes wave theory and the Volume of Fluid Method. The pressure distribution diagram of the fluid-structure interface and the pile structure were observed and analyzed. The maximum equivalent stress on the pile was studied and its variation range was obtained. Compared with Von Mises yield criterion, it was concluded that the pile was stable under such wave conditions.

An Enhanced Direct Anonymous Attestation Scheme with Mutual Authentication for Network-Connected UAV Communication Systems

In network-connected UAV(NCUAV) communication systems, user authentication is replaced by platform identity authentication and integrity check because many NC-UAVs are operated without human intervention. Direct anonymous attestation(DAA) is an attractive cryptographic scheme that provides an elegant balance between platform authentication and anonymity. However, because of the low-level computing capability and limited transmission bandwidth in UAV, the existing DAA schemes are not suitable for NC-UAV communication systems. In this paper, we propose an enhanced DAA scheme with mutual authentication(MA-DAA scheme), which meets the security requirements of NC-UAV communication systems. The proposed MA-DAA scheme, which is based on asymmetric pairings, bundles the identities of trusted platform module(TPM) and Host to solve the malicious module changing attacks. Credential randomization, batch proof and verification, and mutual authentication are realized in the MA-DAA scheme. The computational workload in TPM and Host is reduced in order to meet the low computation and resource requirements in TPM and Host.The entire scheme and protocols are presented,and the security and efficiency of the proposed MA-DAA scheme are proved and analyzed.Our experiment results also confirm the high efficiency of the proposed scheme.

Inhibition of aryl hydrocarbon receptor signaling promotes the terminal differentiation of human erythroblasts

The aryl hydrocarbon receptor(AHR)plays an important role during mammalian embryo development.Inhibition of AHR signaling promotes the development of hematopoietic stem/progenitor cells.AHR also regulates the functional maturation of blood cells,such as T cells and megakaryocytes.However,little is known about the role of AHR modulation during the development of erythroid cells.In this study,we used the AHR antagonist StemRegenin 1(SR1)and the AHR agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin during different stages of human erythropoiesis to elucidate the function of AHR.We found that antagonizing AHR signaling improved the production of human embryonic stem cell derived erythrocytes and enhanced erythroid terminal differentiation.RNA sequencing showed that SR1 treatment of proerythroblasts upregulated the expression of erythrocyte differentiation-related genes and downregulated actin organization-associated genes.We found that SR1 accelerated F-actin remodeling in terminally differentiated erythrocytes,favoring their maturation of the cytoskeleton and enucleation.We demonstrated that the effects of AHR inhibition on erythroid maturation were associated with F-actin remodeling.Our findings help uncover the mechanism for AHRmediated human erythroid cell differentiation.We also provide a new approach toward the large-scale production of functionally mature human pluripotent stem cell-derived erythrocytes for use in translational applications.

A cytoprotective graphene oxide-polyelectrolytes nanoshell for single-cell encapsulation

Graphene oxide(GO)has been increasingly utilized in the fields of food,biomedicine,environment and other fields because of its benign biocompatible.We encapsulated two kinds of GO with different sizes on yeast cells with the assistance of polyelectrolytes poly(styrene sulfonic acid)sodium salt(PSS)and polyglutamic acid(PGA)(termed as Y@GO).The result does not show a significant difference between the properties of the two types of Y@GO(namely Y@GO1 and Y@GO2).The encapsulation layers are optimized as Yeast/PGA/PSS/PGA/GO/PGA/PSS based on the morphology,dispersity,colony-forming unit,and zeta potential.The encapsulation of GO increases the roughness of the yeast.It is proved that the Y@GO increases the survival time and enhance the activity of yeast cells.The GO shell improves the resistance of yeast cells against pH and salt stresses and extends the storage time of yeast cells.

Comprehensive Characterization and Global Transcriptome Analysis of Human Fetal Liver Terminal Erythropoiesis

The fetal liver(FL)is the key erythropoietic organ during fetal development,but knowledge on human FL erythropoiesis is very limited.In this study,we sorted primary erythroblasts from FL cells and performed RNA sequencing(RNA-seq)analyses.We found that temporal gene expression patterns reflected changes in function during primary human FL terminal erythropoiesis.Notably,the expression of genes enriched in proteolysis and autophagy was up-regulated in orthochromatic erythroblasts(OrthoEs),suggesting the involvement of these pathways in enucleation.We also performed RNA-seq of in vitro cultured erythroblasts derived from FL CD34+cells.Comparison of transcriptomes between the primary and cultured erythroblasts revealed significant differences,indicating impacts of the culture system on gene expression.Notably,the expression of lipid metabolism-related genes was increased in cultured erythroblasts.We further immortalized erythroid cell lines from FL and cord blood(CB)CD34+cells(FL-iEry and CB-iEry,respectively).FL-iEry and CB-iEry were immortalized at the proerythroblast stage and can be induced to differentiate into OrthoEs,but their enucleation ability was very low.Comparison of the transcriptomes between OrthoEs with and without enucleation capability revealed the down-regulation of pathways involved in chromatin organization and mitophagy in OrthoEs without enucleation capacity,indicating that defects in chromatin organization and mitophagy contribute to the inability of OrthoEs to enucleate.Additionally,the expression of HBE1,HBZ,and HBG2 was up-regulated in FL-iEry compared with CB-iEry,and such up-regulation was accompanied by down-regulated expression of BCL11A and up-regulated expression of LIN28B and IGF2BP1.Our study provides new insights into human FL erythropoiesis and rich resources for future studies.

A large-scale screening of metal-organic frameworks for iodine capture combining molecular simulation and machine learning

We performed large-scale molecular simulation to screen and identify metal-organic framework materials for gaseous iodine capture,as part of our ongoing effort in addressing management and handling issues of various radionuclides in the grand scheme of spent nuclear fuel reprocessing.Starting from the computation-ready experimental(CoRE)metal-organic frameworks(MOFs)database,grand canonical Monte Carlo simulation was employed to predict the iodine uptake values of the MOFs.A ranking list of MOFs based on their iodine uptake capabilities was generated,with the Top 10 candidates identified and their respective adsorption sites visualized.Subsequently,machine learning was used to establish structure-property relationships to correlate MOFs’various structural and chemical features with their corresponding performances in iodine capture,yielding interpretable common features and design rules for viable MOF adsorbents.The research strategy and framework of the present study could aid the development of high-performing MOF adsorbents for capture and recovery of radioactive iodine,and moreover,other volatile environmentally hazardous species.

Design,synthesis,and applications of stereospecific 1,3-diene carbonyls

The strategy toward the synthesis of various 1,3-dienals or 1,3-dienones is disclosed between diazo compounds and furans,which features metal-free,additive-free,broad functional group tolerance,and readily accessible starting materials.Notably,this strategy is applicable in both intramolecular and intermolecular protocols.Mechanistic studies suggested that the reactions undergo a cyclopropanation/rearrangement sequence.With an E/E-1,3-dienal,corresponding N-tosylhydrazones were readily prepared and subjected to phenylboronic acid to form a double bond migration product and indoles to construct a five-member ring via [3 + 2] annulation reaction.

Atom Recombination of Difluorocarbene Enables 3-Fluorinated Oxindoles from 2-Aminoarylketones

Contrary to the traditional implementation as a difluoromethyl group and recently disclosed role of C1 synthons in synthetic organic chemistry,difluorocarbene(:CF_(2))is reported herein to proceed in unprecedented atom recombination as both a C1 synthon and F1 reagent simultaneously to render valuable 3-fluorinated oxindoles from 2-aminoarylketones.The reaction does not require catalyst and features a broad range of substrates with good functional group compatibility and ease of execution.This transformation could be employed to the quick-constructions of certain bioactive molecule derivatives.The mechanistic experiments and density functional theory(DFT)calculations indicate that this atom recombination reaction of:CF_(2) for the synthesis of 3-fluorinated oxindoles may involve a rearrangement process of epoxide intermediates.