Anisotropic high cycle fatigue property of Sc and Zr-modified Al-Mg alloy fabricated by laser powder bed fusion

This work investigates the defects (pore and lack of fusion), microstructure, and fatigue properties of Sc and Zr-modified Al–Mg alloy on different building directions fabricated by laser powder bed fusion (LPBF). The results showed that transversely deposited (TD) samples exhibited a superior fatigue strength (100.5 MPa) compared to that (57 MPa) of the parallelly deposited (PD) sample, while their tensile and hardness properties were similar. This phenomenon is attributed to two factors: defects and grain/microstructure. For the defects, the lack of fusion resulted in a higher stress concentration in the PD samples than that of the TD samples in the crack initiation stage. For the microstructure, owing to the indistinctive crack deflection and possible cyclic softening of the columnar grains, a decrement in fatigue resistance appears. Thus, the different crack propagation paths led to different columnar grain/equiaxed grain area ratios for the anisotropic fatigue properties. Furthermore, in the TD samples, some grains, with the || building direction orientation, partly led to a higher fatigue resistance of the TD sample than of the PD sample owing to the exceptional dislocation formation

Mir-193b Regulates the Differentiation, Proliferation, and Apoptosis of Bovine Adipose Cells by Targeting the ACSS2/AKT Axis

The precise functions and molecular mechanisms of microRNAs (miRNAs) in adipocytes are primarily unknown. Studies have demonstrated that miR-193b plays a pivotal role in the differentiation of preadipocytes. Herein, we evaluated the effects of bta-miR-193b on the growth and development of adipocytes, using the EdU cell proliferation method, flow cytometry analysis, CCK-8 assay, RT-qPCR, Western blotting, and oil red O staining. We observed that the overexpression of bta-miR-193b significantly affected the differentiation, proliferation, and apoptosis of adipocytes. The results of the dual-fluorescent reporter vector experiments demonstrated that bta-miR-193b directly targeted Acyl-CoA synthetase short-chain family member 2 (ACSS2). Additionally, the effects of ACSS2 overexpression on the proliferation and apoptosis in adipose cells were the opposite of those induced by bta-miR-193b. We also demonstrated that ACSS2 can significantly promote the expression of AKT and pAKT proteins. Therefore, this study presents a novel mechanism by which bta-miR-193b regulates adipocyte development by targeting ACSS2

Correlating multi-scale structure characteristics to mechanical behavior of Caprinae horn sheaths

Horns are used by Bovidae animals for intraspecific combat; as such they are among Nature's toughest materials that require resistance to extreme loads. As a typical subfamily among Bovidae, Caprinae own light-wight horn with balanced strength and toughness. However, their structure and the salient mechanisms that underlie their mechanical behavior remain uncertain. This work clarifies the effect of multi-scale structure characteristics on mechanical behaviors of horn sheath by comparing Cashmere goat, White goat and Black sheep. With the methods of fractographic observations, conformational analysis, acoustic emission and finite element methods. Conformation of keratin and strength of fibre were proposed to influence the tensile/flexural performance a lot under both dried and hydrated condition. The corrugated lamellae structure was assumed to promote crack deflection and enhance dried samples, which showed more advantageous for applications of flexural loading. It is hard to impute the difference of mechanics to any one factor, and the synergism of multi-scale mechanisms is important to mechanical properties in Caprinae horn sheath. This research is expected to further encourage the horn-inspired design of secondary load-carrying lightweight composites

Exploration of Genetic Variants within the Goat A-Kinase Anchoring Protein 12 (AKAP12) Gene and Their Effects on Growth Traits

The A-kinase anchoring protein 12 gene (AKAP12) is a scaffold protein, which can target multiple signal transduction effectors, can promote mitosis and cytokinesis and plays an important role in the regulation of growth and development. In our previous study, P1–7 bp (intron 3) and P2–13 bp (3′UTR) indels within the AKAP12 gene significantly influenced AKAP12 gene expression. Therefore, this study aimed to identify the association between these two genetic variations and growth-related traits in Shaanbei white cashmere goats (SBWC) (n = 1405). Herein, we identified two non-linkage insertions/deletions (indels). Notably, we found that the P1–7 bp indel mutation was related to the height at hip cross (HHC; p < 0.05) and the P2–13 bp indel was associated with body weight, body length, chest depth, chest width, hip width, chest circumference and cannon (bone) circumference in SBWC goats (p < 0.05). Overall, the two indels’ mutations of AKAP12 affected growth traits in goats. Compared to the P1–7 bp indel, the P2–13 bp indel is more suitable for the breeding of goat growth traits