ABAQUS and ANSYS Implementations of the Peridynamics-Based Finite Element Method(PeriFEM)for Brittle Fractures

In this study,we propose the first unified implementation strategy for peridynamics in commercial finite element method(FEM)software packages based on their application programming interface using the peridynamics-based finite element method(PeriFEM).Using ANSYS and ABAQUS as examples,we present the numerical results and implementation details of PeriFEM in commercial FEM software.PeriFEM is a reformulation of the traditional FEM for solving peridynamic equations numerically.It is considered that the non-local features of peridynamics yet possesses the same computational framework as the traditional FEM.Therefore,this implementation benefits from the consistent computational frameworks of both PeriFEM and the traditional FEM.An implicit algorithm is used for both ANSYS and ABAQUS;however,different convergence criteria are adopted owing to their unique features.In ANSYS,APDL enables users to conveniently obtain broken-bond information from UPFs;thus,the convergence criterion is chosen as no new broken bond.In ABAQUS,obtaining broken-bond information is not convenient for users;thus,the default convergence criterion is used in ABAQUS.The codes integrated into ANSYS and ABAQUS are both verified through benchmark examples,and the computational convergence and costs are compared.The results show that,for some specific examples,ABAQUS is more efficient,whereas the convergence criterion adopted in ANSYS is more robust.Finally,3D examples are presented to demonstrate the ability of the proposed approach to deal with complex engineering problems.

急诊内科昏迷的病因和临床急救对策研究

目的探讨急诊内科昏迷病因与临床急救对策。方法选取我院2013年9月-2016年1月急诊内科昏迷患者92例,对其昏迷病因及相应的急救对策加以分析。结果本试验中,乙醇中毒(20.7%)、脑出血(22.8%)、心血管事件(16.3%)所致昏迷患者居多;临床抢救结果中,病情好转患者62例(67.4%),病情稳定患者21例(22.8%),病情恶化患者7例(7.6%),死亡患者2例(2.2%);急诊内科92例昏迷患者影响其预后的因素中,原发疾病状况、昏迷程度及发病后入院时间在患者预后所产生的影响对比差异具有统计学意义(P<0.05);但患者性别与年龄这两项因素在其预后效果的影响中无统计学意义(P>0.05)。结论对昏迷患者实施及时有效的临床抢救、及早入院治疗、加强预防等有助于急诊内科昏迷患者死亡率的有效降低。

低血糖性脑病误诊11例分析

目的探讨低血糖脑病误诊原因。方法回顾性分析2013年9月-2015年10月我院收治的低血糖脑病患者的临床资料。结果 11例低血糖脑病被误诊为急性脑血管病、癫痫、精神类疾病。结论低血糖脑病易被误诊,尤其对老年患者,对突发意识障碍、癫痫发作、精神异常者应常规行血糖检查,及时确诊并今早治疗,以免影响预后。

An Analysis of the Method to Improve the Effectiveness of Ideological and political Education in Universities in the Era of We-Media

The emergence of we-media provides a new life and learning platform for college students,which is beneficial to the college students'knowledge acquisition and development of individual character.However,it also challenges the traditional mode of ideological and political education,weakening the influence of the discourse ideological and political education,and the mainstream ideology.Facing these new challenges,determine to better carry out ideological and political education in the new era,colleges and universities must innovate the mode of ideological and political education,enhance the discourse power of ideological and political education and strengthen the ideological construction of colleges and universities in the we-media era.

Development of a droplet digital polymerase chain reaction assay for the sensitive detection of total and integrated HIV-1 DNA

Background:Total human immunodeficiency virus(HIV)DNA and integrated HIV DNA are widely used markers of HIV persistence.Droplet digital polymerase chain reaction(ddPCR)can be used for absolute quantification without needing a standard curve.Here,we developed duplex ddPCR assays to detect and quantify total HIV DNA and integrated HIV DNA.Methods:The limit of detection,dynamic ranges,sensitivity,and reproducibility were evaluated by plasmid constructs containing both the HIV long terminal repeat(LTR)and human CD3 gene(for total HIV DNA)and ACH-2 cells(for integrated HIV DNA).Forty-two cases on stable suppressive antiretroviral therapy(ART)were assayed in total HIV DNA and integrated HIV DNA.Correlation coefficient analysis was performed on the data related to DNA copies and cluster of differentiation 4 positive(CD4^(+))T-cell counts,CD8^(+)T-cell counts and CD4/CD8 T-cell ratio,respectively.The assay linear dynamic range and lower limit of detection(LLOD)were also assessed.Results:The assay could detect the presence of HIV-1 copies 100%at concentrations of 6.3 copies/reaction,and the estimated LLOD of the ddPCR assay was 4.4 HIV DNA copies/reaction(95%confidence intervals[CI]:3.6-6.5 copies/reaction)with linearity over a 5-log_(10)-unit range in total HIV DNA assay.For the integrated HIV DNA assay,the LLOD was 8.0 copies/reaction(95%CI:5.8-16.6 copies/reaction)with linearity over a 3-log 10-unit range.Total HIV DNA in CD4^(+)T cells was positively associated with integrated HIV DNA(r=0.76,P<0.0001).Meanwhile,both total HIV DNA and integrated HIV DNA in CD4^(+)T cells were inversely correlated with the ratio of CD4/CD8 but positively correlated with the CD8^(+)T-cell counts.Conclusions:This ddPCR assay can quantify total HIV DNA and integrated HIV DNA efficiently with robustness and sensitivity.It can be readily adapted for measuring HIV DNA with non-B clades,and it could be beneficial for testing in clinical trials.

Changing roles of CD3^(+)CD8^(low) T cells in combating HIV-1 infection

Background:Cluster of differentiation 8(CD8 T)cells play critical roles in eradicating human immunodeficiency virus(HIV)-1 infection,but little is known about the effects of T cells expressing CD8 at low levels(CD8^(low))or high levels(CD8^(high))on HIV-1 replication inhibition after HIV-1 invasion into individual.Methods:Nineteen patients who had been acutely infected with HIV-1(AHI)and 20 patients with chronic infection(CHI)for≥2 years were enrolled in this study to investigate the dynamics of the quantity,activation,and immune responses of CD3^(+)CD8^(low) T cells and their counterpart CD3^(+)CD8^(high) T cells at different stages of HIV-1 infection.Results:Compared with healthy donors,CD3^(+)CD8^(low) T cells expanded in HIV-1-infected individuals at different stages of infection.As HIV-1 infection progressed,CD3^(+)CD8^(low) T cells gradually decreased.Simultaneously,CD3^(+)CD8^(high) T cells was significantly reduced in the first month of AHI and then increased gradually as HIV-1 infection progressed.The classical activation of CD3^(+)CD8^(low) T cells was highest in the first month of AHI and then reduced as HIV-1 infection progressed and entered the chronic stage.Meanwhile,activated CD38^(-)HLA-DR^(+)CD8^(low) T cells did not increase in the first month of AHI,and the number of these cells was inversely associated with viral load(r=-0.664,P=0.004)but positively associated with the CD4 T-cell count(r=0.586,P=0.014).Increased programmed cell death protein 1(PD-1)abundance on CD3^(+)CD8^(low) T cells was observed from the 1st month of AHI but did not continue to be enhanced,while a significant T cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibition motif(ITIM)domains(TIGIT)abundance increase was observed in the 12th month of infection.Furthermore,increased PD-1 and TIGIT abundance on CD3^(+)CD8^(low) T cells was associated with a low CD4 T-cell count(PD-1:r=-0.456,P=0.043;TIGIT:r=-0.488,P=0.029)in CHI.Nonetheless,the nonincrease in PD-1 expression on classically activated CD3^(+)CD8^(low) T cells was inversely associated with HIV-1 viremia in the first month of AHI(r=-0.578,P=0.015).Notably,in the first month of AHI,few CD3^(+)CD8^(low) T cells,but comparable amounts of CD3^(+)CD8^(high) T cells,responded to Gag peptides.Then,weaker HIV-1-specific T-cell responses were induced in CD3^(+)CD8^(low) T cells than CD3^(+)CD8^(high) T cells at the 3rd and 12th months of AHI and in CHI.Conclusions:Our findings suggest that CD3^(+)CD8^(low) T cells play an anti-HIV role in the first month of infection due to their abundance but induce a weak HIV-1-specific immune response.Subsequently,CD3^(+)CD8^(low) T-cell number decreased gradually as infection persisted,and their anti-HIV functions were inferior to those of CD3^(+)CD8^(high) T cells.

Integration of nanoindentation and finite element method for interpretable tensile properties:A crossscale calculation method of uneven joints

Nanoindentation testing and its Reverse Analysis Method(RAM)show great potential in understanding the tensile properties of metallic alloys with various microstructures.Nevertheless,the tensile properties of heterogeneous materials such as nickel-based superalloy welded joints have not been well interpreted by combining the microstructures and nanoindentation results,due to their diverse and complex microscopic zones,which throws shade on the properties of separated zones in the material.Here we demonstrated a new method of implanting nanoindentation results into Finite Element Method(FEM)and applied the method to the welded joints with the zones of various microstructure features.The local properties are calculated by the nanoindentation data using RAM,and used as input of Finite Element(FE)simulation of an identical indentation process,to in turn verify the accuracy and reliability of the reverse model.The simulation results reveal that the global mechanical behaviors,such as Young's modulus,yield strength and strain hardening exponent,are related to the local properties to a great extent.Thus,the global properties can be verified by simulation straight after experiments,taking consideration of local properties and dimension parameters of different zones.It is shown that the maximum error between calculation of RAM and testing is within 5.1%in different zones,and the errors of maximum indentation depth and residual depth obtained by FE simulation are less than 2.4%,which indicates that the method provides a reliable prediction of mechanical properties of superalloy welded joints.

Impacts of transmembrane serine protease 4 expression on susceptibility to severe acute respiratory syndrome coronavirus 2

To the Editor:Transmembrane serine protease 4(TMPRSS4;OMIM:606565),which encodes a member of the serine protease family,is involved in various biological processes related to diseases such as cancer and pediatric neurodegenerative disorders.