Heavy Ball Flexible GMRES Method for Nonsymmetric Linear Systems

Flexible GMRES (FGMRES) is a variant of preconditioned GMRES, which changes preconditioners at every Arnoldi step. GMRES often has to be restarted in order to save storage and reduce orthogonalization cost in the Arnoldi process. Like restarted GMRES, FGMRES may also have to be restarted for the same reason. A major disadvantage of restarting is the loss of convergence speed. In this paper, we present a heavy ball flexible GMRES method, aiming to recoup some of the loss in convergence speed in the restarted flexible GMRES while keep the benefit of limiting memory usage and controlling orthogonalization cost. Numerical tests often demonstrate superior performance of the proposed heavy ball FGMRES to the restarted FGMRES.     

Berbamine Hydrochloride Inhibits African Swine Fever Virus Infection In Vitro

African swine fever virus (ASFV) causes a viral disease in swine with a mortality rate of approximately 100%, threatening the global pig industry’s economic development. However, vaccines are not yet commercially available, and other antiviral therapeutics, such as antiviral drugs, are urgently needed. In this study, berbamine hydrochloride, a natural bis-benzylisoquinoline alkaloid isolated from the traditional Chinese herb Berberis amurensis, showed significant antiviral activity against ASFV. The 50% cytotoxic concentration (CC₅₀) of berbamine hydrochloride in porcine alveolar macrophages (PAMs) was 27.89 μM. The antiviral activity assay demonstrated that berbamine hydrochloride inhibits ASFV in a dose-dependent manner. In addition, a 4.14 log TCID₅₀ decrease in the viral titre resulting from non-cytotoxic berbamine hydrochloride was found. Moreover, the antiviral activity of berbamine hydrochloride was maintained for 48h and took effect at multiplicities of infection (MOI) of 0.01, 0.1, and 1. The time-of-addition analysis revealed an inhibitory effect throughout the entire virus life-cycle. A subsequent viral entry assay verified that berbamine hydrochloride blocks the early stage of ASFV infection. Moreover, similar anti-ASFV activity of berbamine hydrochloride was also found in PK-15 and 3D4/21 cells. In summary, these results indicate that berbamine hydrochloride is an effective anti-ASFV natural product and may be considered a novel antiviral drug.     

DNA Origami Disguises Herpes Simplex Virus 1 Particles and Controls Their Virulence

DNA nanostructures are well-established vectors for packaging diversified payloads for targeted cellular delivery. Here, DNA origami rectangular sheets were combined with Herpes Simplex Virus 1 (HSV1) capsids to demonstrate surface coverage of the particle via electrostatic interactions. The optimized origami:HSV1 molar ratios led to characteristic packaging geometries ranging from dispersed “HSV1 pockets” to agglomerated “HSV1 sleeves”. “Pockets” were disguised from cells in HeLa and B16F10 cells and were 44.2% less infective than naked HSV1 particles. However, the pockets were 117% more infective than naked HSV1 particles when the origami sheets were coated with folic acid. We observed infectivity from naked origami, but they are 99.1% less infective with respect to HSV1 and 99.6% less infective with respect to the pocket complexes. This work suggests that DNA origami can selectively modulate virus infectivity.     

A Comprehensive In Silico Study of New Metabolites from Heteroxenia fuscescens with SARS-CoV-2 Inhibitory Activity

Chemical investigation of the total extract of the Egyptian soft coral Heteroxenia fuscescens, led to the isolation of eight compounds, including two new metabolites, sesquiterpene fusceterpene A (1) and a sterol fuscesterol A (4), along with six known compounds. The structures of 1–8 were elucidated via intensive studies of their 1D, 2D-NMR, and HR-MS analyses, as well as a comparison of their spectral data with those mentioned in the literature. Subsequent comprehensive in-silico-based investigations against almost all viral proteins, including those of the new variants, e.g., Omicron, revealed the most probable target for these isolated compounds, which was found to be M^pro. Additionally, the dynamic modes of interaction of the putatively active compounds were highlighted, depending on 50-ns-long MDS. In conclusion, the structural information provided in the current investigation highlights the antiviral potential of H. fuscescens metabolites with 3β,5α,6β-trihydroxy steroids with different nuclei against SARS-CoV-2, including newly widespread variants.     

ILASII系统维护中的问题及解决方法

以ILASII为研究对象,结合山东艺术学院图书馆的实际,分析了ILASII系统在应用过程中出现的常见问题,并给出了相应的的解决方法。     

球透镜的衍射焦斑强度分布研究

根据国内外光通信耦合器件发展的趋势,研制了一种新型玻璃,依靠液体表面张力的作用,首次采用槽沉法来制备球透镜,得到了理想的效果。通过对直径为0.8mm的球透镜的焦斑强度分布进行研究,结果表明:当通光孔径分别为0.2mm,0.4mm和0.8mm时,球透镜的衍射焦斑强度的分布分别为0.2μm,0.4μm和1.0μm。因此,伴随着通光孔径的增加,球透镜的衍射焦斑强度分布增大,衍射的强度减小。     

博莱霉素A_5的类酶性研究

研究了博莱霉素Ａ５（ＢＬＭＡ５）与ＤＮＡ作用前后的光谱性质及初步的动力学性质，发现ＢＬＭＡ５可催化ＤＮＡ氧化断链，而且符合米氏动力学．通过对ＢＬＭＡ５的催化效率、底物专一性以及温度、ｐＨ、金属离子对ＢＬＭＡ５催化ＤＮＡ断链反应影响的研究，发现ＢＬＭＡ５的作用行为在许多方面与酶的催化行为非常类似，提出ＢＬＭＡ５是一种小分子生物催化剂的看法．     

The flow of a model suspension fluid past a sphere

The paper is concerned with the flow of a dilute suspension of monosized spheroids past a sphere placed at the centerline of a cylindrical tube. The suspension is modeled by the transversely isotropic fluid model and the numerical solution is obtained by a time-dependent boundary element method. No steady-state solution to the problem was found. However, the amplitude of the long-time oscillations in the drag force on the sphere is only about 1% of its mean value at a solid volume concentration of 0.01 and an aspect ratio of 10 for the spheroids. The initial orientation of the microstructure has a small effect on the drag force: it can give rise to a ±1 % variation in the drag force at large time.     

乙型肝炎病毒携带者孕妇与正常孕妇妊娠结局比较

目的探索妊娠合并乙肝病毒感染的妊娠结局及孕晚期肌注乙肝免疫球蛋白对预防乙肝病毒感染作用。方法对2003年11月至2004年11月本院孕产妇妊娠结局分析。结果(1)妊娠合并乙肝病毒感染者胎膜早破、胎儿窘迫、剖宫率升高;(2)对乙肝病毒携带者孕晚期肌注乙肝免疫球蛋白新生儿感染为8%,比文献报道低。结论妊娠合并乙肝病毒感染易发生胎膜早破、胎儿窘迫,使剖宫产率升高,孕晚期肌注乙肝免疫球蛋白,对预防乙肝病毒感染有一定作用。     

Cn中单位球上几个全纯函数空间上加权复合算子的有界性

讨论了C^n上单位球中p-Bloch空间上加权复合算子Tφ，ψ的有界性，得到Tφ，ψ是β′到β′有界算子的几个充分条件，此外还讨论了p-Bloch空间和小p-Bloch空间上复合算子T1，ψ的有界性，得到了几个充分条件和必要条件，就单位球的情形扩展了[2]的结论．