Analytical solution for the effective elastic properties of rocks with the tilted penny-shaped cracks in the transversely isotropic background

Seismic prediction of cracks is of great significance in many disciplines,for which the rock physics model is indispensable.However,up to now,multitudinous analytical models focus primarily on the cracked rock with the isotropic background,while the explicit model for the cracked rock with the anisotropic background is rarely investigated in spite of such case being often encountered in the earth.Hence,we first studied dependences of the crack opening displacement tensors on the crack dip angle in the coordinate systems formed by symmetry planes of the crack and the background anisotropy,respectively,by forty groups of numerical experiments.Based on the conclusion from the experiments,the analytical solution was derived for the effective elastic properties of the rock with the inclined penny-shaped cracks in the transversely isotropic background.Further,we comprehensively analyzed,according to the developed model,effects of the crack dip angle,background anisotropy,filling fluid and crack density on the effective elastic properties of the cracked rock.The analysis results indicate that the dip angle and background anisotropy can significantly either enhance or weaken the anisotropy degrees of the P-and SH-wave velocities,whereas they have relatively small effects on the SV-wave velocity anisotropy.Moreover,the filling fluid can increase the stiffness coefficients related to the compressional modulus by reducing crack compliance parameters,while its effects on shear coefficients depend on the crack dip angle.The increasing crack density reduces velocities of the dry rock,and decreasing rates of the velocities are affected by the crack dip angle.By comparing with exact numerical results and experimental data,it was demonstrated that the proposed model can achieve high-precision estimations of stiffness coefficients.Moreover,the assumption of the weakly anisotropic background results in the consistency between the proposed model and Hudson's published theory for the orthorhombic rock.

Neutrophils inhibit CD8^(+)T cells immune response by arginase-1 signaling in patients with sepsis

BACKGROUND:Patients with sepsis often exhibit an acute inflammatory response,followed by an immunosuppressive phase with a poor immune response.However,the underlying mechanisms have not been fully elucidated.METHODS:We sought to comprehensively characterize the transcriptional changes in neutrophils of patients with sepsis by transcriptome sequencing.Additionally,we conducted a series of experiments,including real-time quantitative polymerase chain reaction(RT-qPCR)and flow cytometry to investigate the role of arginase-1 signaling in sepsis.RESULTS:Through the analysis of gene expression profiles,we identified that the negative regulation of T cell activation signaling was enriched,and the expression of arginase-1 was high in neutrophils from patients with sepsis.Furthermore,we conducted flow cytometry and found that the function of CD8^(+)T cells in septic patients was impaired.Moreover,neutrophils from septic patients inhibited the percentage of polyfunctional effector CD8^(+)T cells through arginase-1.Additionally,the proportions of granzyme B^(+)IFN^(-)γ^(+)CD8^(+)T and TNF^(-)α^(+)IFN^(-)γ^(+)CD8^(+)T cells increased after inhibition of arginase-1 signaling.CONCLUSION:The impaired effector function of CD8^(+)T cells could be restored by blocking arginase-1 signaling in patients with sepsis.

Eutectic high entropy alloy syntactic foam

High-strength metallic foams have a wide range of applications in engineering as lightweight structural and energy-absorbing materials.However,it is challenging to obtain metallic foam with both good energy absorption performance and high strength.Here,we developed a novel metal matrix syntactic foam fabri-cated with AlCoCrFeNi_(2.1) eutectic high entropy alloy and alumina cenospheres that exhibits a remarkable combination of high strength and energy absorption performance under both quasi-static and dynamic compression.The porous structure of syntactic foam fully exploits the properties of the AlCoCrFeNi_(2.1) alloy matrix with a unique FCC/B2 dual-phase eutectic microstructure and thus yields exceptional per-formance.We discovered that this dual-phase microstructure not only provides high strength but also allows the pores to collapse in a progressive and diffusive way,which enables the formation of a high and smooth energy absorption platform.It is found that the heterogeneity between the two phases in the matrix can provide back stress strengthening,and it also induces multiple micro shear bands and microcracks as additional energy dissipation modes as the deformation proceeds.This unique mechanism ensures the strength of microstructures and makes them fracture promptly,which causes the balance of strengthening and softening on the macro scale.This work opens the avenue for developing advanced high-strength lightweight structural and energy-absorbing materials.

Gene editing: an instrument for practical application of gene biology to plant breeding

Plant breeding is well recognized as one of the most important means to meet food security challenges caused by the ever-increasing world population. During the past three decades, plant breeding has been empowered by both new knowledge on trait development and regulation(e.g., functional genomics) and new technologies(e.g., biotechnologies and phenomics). Gene editing, particularly by clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein(Cas) and its variants, has become a powerful technology in plant research and may become a game-changer in plant breeding. Traits are conferred by coding and non-coding genes. From this perspective, we propose different editing strategies for these two types of genes. The activity of an encoded enzyme and its quantity are regulated at transcriptional and post-transcriptional, as well as translational and post-translational, levels. Different strategies are proposed to intervene to generate gene functional variations and consequently phenotype changes. For non-coding genes, trait modification could be achieved by regulating transcription of their own or target genes via gene editing. Also included is a scheme of protoplast editing to make gene editing more applicable in plant breeding. In summary, this review provides breeders with a host of options to translate gene biology into practical breeding strategies, i.e., to use gene editing as a mechanism to commercialize gene biology in plant breeding.

Lattice distortion and magnetic property of high entropy alloys at low temperatures

Deformation mechanisms and magnetic properties of medium and high entropy alloys(MEA/HEAs)closely relate to lattice distortion and are strongly temperature-dependent,in particular,at low temperature ranges.However,little attention has been paid to the evolution of lattice distortion with temperature decreasing and its effects on deformation behavior and magnetic state transition.In this work,we carry out in situ synchrotron radiation based X-ray powder diffraction(SR-XRD)experiments from 293 to 123 K aiming for determining lattice distortion evolutions of Cr Co Ni MEA,Cr Fe Co Ni and Cr Mn Fe Co Ni HEAs.Magnetic measurements at corresponding low temperatures and cryogenic ranges are further conducted.The in situ SR-XRD results demonstrate a general reduction of lattice distortion magnitude with temperature decreasing,which shows a similar tendency with that of reported stacking fault energy(SFE)values.It is thus suggested that lattice distortion reduction possibly makes a critical contribution to deformation mechanism transition.The magnetic measurement results show a clear ferromagnetic transition of Cr Fe Co Ni HEA when temperature is below 173 K.While,no obvious magnetic state transition is observed for Cr Co Ni MEA and Cr Mn Fe Co Ni HEA.The present findings on lattice distortion evolutions will pave the way for designing targeted HEAs with particular properties.

Tissue-specific expression, developmentally and spatially regulated alternative splicing, and protein subcellular localization of OsLpa1 in rice

The OsLpa1 gene（LOC_Os02g57400） was identified to be involved in phytic acid（PA） metabolism because its knockout and missense mutants reduce PA content in rice grain. However, little is known about the molecular characteristics of OsLpa1 in rice and of its homologues in other plants. In the present study, the spatial pattern of OsLpa1 expression was revealed using OsLpa1 promoter：：GUS transgenic plants（GUS： β-glucuronidase）; GUS histochemical assay showed that OsLpa1 was strongly expressed in stem, leaf, and root tissues, but in floral organ it is expressed mainly and strongly in filaments. In seeds, GUS staining was concentrated in the aleurone layers; a few blue spots were observed in the outer layers of embryo, but no staining was observed in the endosperm. Three OsLpa1 transcripts（OsLpa1.1, OsLpa1.2, OsLpa1.3） are produced due to alternative splicing; quantitative reversetranscriptase polymerase chain reaction（RT-PCR） analysis revealed that the abundance of OsLpa1.3 was negligible compared with OsLpa1.1 and OsLpa1.2 in all tissues. OsLpa1.2 is predominant in germinating seeds（about 5 times that of OsLpa1.1）, but its abundance decreases quickly with the development of seedlings and plants, whereas the abundance of OsLpa1.1 rises and falls, reaching its highest level in 45-d-old plants, with abundance greater than that of OsLpa1.2 in both leaves and roots. In seeds, the abundance of OsLpa1 continuously increases with seed growth, being 27.5 and 15 times greater in 28-DAF（day after flowering） seeds than in 7-DAF seeds for OsLpa1.1 and OsLpa1.2, respectively. Transient expression of chimeric genes with green fluorescence protein（GFP） in rice protoplasts demonstrated that all proteins encoded by the three OsLpa1 transcripts are localized to the chloroplast.