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  • 1
    Online Resource
    Online Resource
    Phase Stability, Elastic Modulus and Elastic Anisotropy of X Doped (X = Zn, Zr and Ag) Al3Li: Insight from First-Principles Calculations
    MDPI AG ; 2021
    In:  Crystals Vol. 12, No. 1 ( 2021-12-21), p. 7-
    Details
    In: Crystals, MDPI AG, Vol. 12, No. 1 ( 2021-12-21), p. 7-
    Abstract: In present work, the effects of alloying elements X (X = Zn, Zr and Ag) doping on the phase stability, elastic properties, anisotropy and Debye temperature of Al3Li were studied by the first-principles method. Results showed that pure and doped Al3Li can exist and be stable at 0 K. Zn and Ag elements preferentially occupy the Al sites and Zr elements tend to occupy the Li sites. All the Cij obey the mechanical stability criteria, indicating the mechanical stability of these compounds. The overall anisotropy decreases in the following order: Al23Li8Ag 〉 Al3Li 〉 Al23Li8Zn 〉 Al24Li7Zr, which shows that the addition of Zn and Zr has a positive effect on reducing the anisotropy of Al3Li. The shear anisotropic factors for Zn and Zr doped Al3Li are very close to one, meaning that elastic moduli do not strongly depend on different shear planes. For pure and doped Al3Li phase, the transverse sound velocities νt1 and νt2 among the three directions are smaller than the longitudinal sound velocity νl. Moreover, only the addition of Zn is beneficial to increasing the ΘD of Al3Li among the three elements.
    Type of Medium: Online Resource
    ISSN: 2073-4352
    URL: Article
    DOI: 10.3390/cryst12010007
    Language: English
    Publisher: MDPI AG
    Publication Date: 2021
    detail.hit.zdb_id: 2661516-2
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  • 2
    Online Resource
    Online Resource
    The Effect of Alloying Elements on the Structural Stability, Mechanical Properties, and Debye Temperature of Al3Li: A First-Principles Study
    MDPI AG ; 2018
    In:  Materials Vol. 11, No. 8 ( 2018-08-18), p. 1471-
    Details
    In: Materials, MDPI AG, Vol. 11, No. 8 ( 2018-08-18), p. 1471-
    Abstract: The structural stability, mechanical properties, and Debye temperature of alloying elements X (X = Sc, Ti, Co, Cu, Zn, Zr, Nb, and Mo) doped Al3Li were systematically investigated by first-principles methods. A negative enthalpy of formation ΔHf is predicted for all Al3Li doped species which has consequences for its structural stability. The Sc, Ti, Zr, Nb, and Mo are preferentially occupying the Li sites in Al3Li while the Co, Cu, and Zn prefer to occupy the Al sites. The Al–Li–X systems are mechanically stable at 0 K as elastic constants Cij has satisfied the stability criteria. The values of bulk modulus B for Al–Li–X (X = Sc, Ti, Co, Cu, Zr, Nb, and Mo) alloys (excluding Al–Li–Zn) increase with the increase of doping concentration and are larger than that for pure Al3Li. The Al6LiSc has the highest shear modulus G and Young’s modulus E which indicates that it has stronger shear deformation resistance and stiffness. The predicted universal anisotropy index AU for pure and doped Al3Li is higher than 0, implying the anisotropy of Al–Li–X alloy. The Debye temperature ΘD of Al12Li3Ti is highest among the Al–Li–X system which predicts the existence of strong covalent bonds and thermal conductivity compared to that of other systems.
    Type of Medium: Online Resource
    ISSN: 1996-1944
    URL: Article
    DOI: 10.3390/ma11081471
    Language: English
    Publisher: MDPI AG
    Publication Date: 2018
    detail.hit.zdb_id: 2487261-1
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  • 3
    Online Resource
    Online Resource
    STAB-GCN: A Spatio-Temporal Attention-Based Graph Convolutional Network for Group Activity Recognition
    MDPI AG ; 2023
    In:  Mathematics Vol. 11, No. 14 ( 2023-07-12), p. 3074-
    Details
    In: Mathematics, MDPI AG, Vol. 11, No. 14 ( 2023-07-12), p. 3074-
    Abstract: Group activity recognition is a central theme in many domains, such as sports video analysis, CCTV surveillance, sports tactics, and social scenario understanding. However, there are still challenges in embedding actors’ relations in a multi-person scenario due to occlusion, movement, and light. Current studies mainly focus on collective and individual local features from the spatial and temporal perspectives, which results in inefficiency, low robustness, and low portability. To this end, a Spatio-Temporal Attention-Based Graph Convolution Network (STAB-GCN) model is proposed to effectively embed deep complex relations between actors. Specifically, we leverage the attention mechanism to attentively explore spatio-temporal latent relations between actors. This approach captures spatio-temporal contextual information and improves individual and group embedding. Then, we feed actor relation graphs built from group activity videos into our proposed STAB-GCN for further inference, which selectively attends to the relevant features while ignoring those irrelevant to the relation extraction task. We perform experiments on three available group activity datasets, acquiring better performance than state-of-the-art methods. The results verify the validity of our proposed model and highlight the obstructive impacts of spatio-temporal attention-based graph embedding on group activity recognition.
    Type of Medium: Online Resource
    ISSN: 2227-7390
    URL: Article
    DOI: 10.3390/math11143074
    Language: English
    Publisher: MDPI AG
    Publication Date: 2023
    detail.hit.zdb_id: 2704244-3
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  • 4
    Online Resource
    Online Resource
    Inactivation of Target RNA Cleavage of a III-B CRISPR-Cas System Induces Robust Autoimmunity in Saccharolobus islandicus
    MDPI AG ; 2022
    In:  International Journal of Molecular Sciences Vol. 23, No. 15 ( 2022-07-31), p. 8515-
    Details
    In: International Journal of Molecular Sciences, MDPI AG, Vol. 23, No. 15 ( 2022-07-31), p. 8515-
    Abstract: Type III CRISPR-Cas systems show the target (tg)RNA-activated indiscriminate DNA cleavage and synthesis of oligoadenylates (cOA) and a secondary signal that activates downstream nuclease effectors to exert indiscriminate RNA/DNA cleavage, and both activities are regulated in a spatiotemporal fashion. In III-B Cmr systems, cognate tgRNAs activate the two Cmr2-based activities, which are then inactivated via tgRNA cleavage by Cmr4, but how Cmr4 nuclease regulates the Cmr immunization remains to be experimentally characterized. Here, we conducted mutagenesis of Cmr4 conserved amino acids in Saccharolobus islandicus, and this revealed that Cmr4α RNase-dead (dCmr4α) mutation yields cell dormancy/death. We also found that plasmid-borne expression of dCmr4α in the wild-type strain strongly reduced plasmid transformation efficiency, and deletion of CRISPR arrays in the host genome reversed the dCmr4α inhibition. Expression of dCmr4α also strongly inhibited plasmid transformation with Cmr2αHD and Cmr2αPalm mutants, but the inhibition was diminished in Cmr2αHD,Palm. Since dCmr4α-containing effectors lack spatiotemporal regulation, this allows an everlasting interaction between crRNA and cellular RNAs to occur. As a result, some cellular RNAs, which are not effective in mediating immunity due to the presence of spatiotemporal regulation, trigger autoimmunity of the Cmr-α system in the S. islandicus cells expressing dCmr4α. Together, these results pinpoint the crucial importance of tgRNA cleavage in autoimmunity avoidance and in the regulation of immunization of type III systems.
    Type of Medium: Online Resource
    ISSN: 1422-0067
    URL: Article
    DOI: 10.3390/ijms23158515
    Language: English
    Publisher: MDPI AG
    Publication Date: 2022
    detail.hit.zdb_id: 2019364-6
    SSG: 12
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  • 5
    Online Resource
    Online Resource
    First Principles Study on the Thermodynamic and Elastic Mechanical Stability of Mg2X (X = Si,Ge) Intermetallics with (anti) Vacancy Point Defects
    MDPI AG ; 2020
    In:  Crystals Vol. 10, No. 3 ( 2020-03-23), p. 234-
    Details
    In: Crystals, MDPI AG, Vol. 10, No. 3 ( 2020-03-23), p. 234-
    Abstract: In this paper, based on the density functional theory, through thermodynamic and mechanical stability criteria, the crystal cell model of intermetallic compounds with vacancy and anti-site point defects is constructed and the lattice constant, formation heat, binding energy, elastic constant, and elastic modulus of Mg2X (X = Si, Ge) intermetallics with or without point defects are calculated. The results show that the difference in the atomic radius leads to the instability and distortion of crystal cells with point defects; Mg2X are easier to form vacancy defects than anti-site defects on the X (X = Si, Ge) lattice site, and form anti-site defects on the Mg lattice site. Generally, the point defect is more likely to appear at the Mg position than at the Si or Ge position. Among the four kinds of point defects, the anti-site defect x M g is the easiest to form. The structure of intermetallics without defects is more stable than that with defects, and the structure of the intermetallics with point defects at the Mg position is more stable than that at the Si/Ge position. The anti-site and vacancy defects will reduce the material’s resistance to volume deformation shear strain, and positive elastic deformation, and increase the mechanical instability of the elastic deformation of the material. Compared with the anti-site point defect, the void point defect can lead to the mechanical instability of the transverse deformation of the material and improve the plasticity of the material. The research in this paper is helpful for the analysis of the mechanical stability of the elastic deformation of Mg2X (X = Si, Ge) intermetallics under the service condition that it is easy to produce vacancy and anti-site defects.
    Type of Medium: Online Resource
    ISSN: 2073-4352
    URL: Article
    DOI: 10.3390/cryst10030234
    Language: English
    Publisher: MDPI AG
    Publication Date: 2020
    detail.hit.zdb_id: 2661516-2
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  • 6
    Online Resource
    Online Resource
    First Principle Study on Mg2X (X = Si, Ge, Sn) Intermetallics by Bi Micro-Alloying
    MDPI AG ; 2021
    In:  Crystals Vol. 11, No. 2 ( 2021-01-29), p. 142-
    Details
    In: Crystals, MDPI AG, Vol. 11, No. 2 ( 2021-01-29), p. 142-
    Abstract: Being a positive candidate reinforcement material for laminar composites, the Mg2X (X = Si, Ge, Sn) based intermetallics have attracted much attention. The elastic properties, anisotropy, and electronic properties of intermetallic compounds with Bi-doped Mg2X (X = Si, Ge, Sn) are calculated by the first principles method. Results show that the lattice parameters of Mg2X are smaller than those of Bi-doped Mg2X. The element Bi preferentially occupies the position of the X (X = Si, Ge, Sn) atom than other positions. Mg2X (X = Si, Ge, Sn), Mg63X32Bi, Mg64X31Bi, Mg64Ge32Bi, and Mg64Sn32Bi are mechanically stable, while Mg64Si32Bi indicates that it cannot exist stably. The doping of alloying element Bi reduces the shear deformation resistance of the Mg2X (X = Si, Ge, Sn) alloy. The pure and Bi-doped Mg2X (X = Si, Ge, Sn) exhibits elastic and anisotropic characteristics. The contribution of the Bi orbitals of Mg63X32Bi, Mg64X31Bi, and Mg63X32Bi are different, resulting in different hybridization effects in three types of Bi-doped Mg2X.
    Type of Medium: Online Resource
    ISSN: 2073-4352
    URL: Article
    DOI: 10.3390/cryst11020142
    Language: English
    Publisher: MDPI AG
    Publication Date: 2021
    detail.hit.zdb_id: 2661516-2
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  • 7
    Online Resource
    Online Resource
    Hydroxy Selenomethionine Alleviates Hepatic Lipid Metabolism Disorder of Pigs Induced by Dietary Oxidative Stress via Relieving the Endoplasmic Reticulum Stress
    MDPI AG ; 2022
    In:  Antioxidants Vol. 11, No. 3 ( 2022-03-15), p. 552-
    Details
    In: Antioxidants, MDPI AG, Vol. 11, No. 3 ( 2022-03-15), p. 552-
    Abstract: This study used 40 castrated male pigs to determine the protective effects of a new selenium molecule (hydroxy selenomethionine, OH-SeMet) on dietary oxidative stress (DOS) induced hepatic lipid metabolism disorder, and corresponding response of selenotranscriptome. The pigs were randomly grouped into 5 dietary treatments and fed a basal diet formulated with either normal corn and oils or oxidized diet in which the normal corn and oils were replaced by aged corn and oxidized oils, and supplemented with OH-SeMet at 0.0, 0.3, 0.6 and 0.9 mg Se/kg for a period of 16 weeks (n = 8). The results showed that DOS induced liver damage, increased serum alanine aminotransferase (ALT) and alkaline phosphatase (ALP) levels, decreased serum triacylglycerol (TG) level, suppressed antioxidant capacity in the liver, and changed lipid metabolism enzyme activity, thus causing lipid metabolism disorder in the liver. The DOS-induced lipid metabolism disorder was accompanied with endoplasmic reticulum (ER) stress, changes in lipid metabolism-related genes and selenotranscriptome in the liver. Dietary Se supplementation partially alleviated the negative impact of DOS on the lipid metabolism. These improvements were accompanied by increases in Se concentration, liver index, anti-oxidative capacity, selenotranscriptome especially 11 selenoprotein-encoding genes, and protein abundance of GPX1, GPX4 and SelS in the liver, as well as the decrease in SelF abundance. The Se supplementation also alleviated ER stress, restored liver lipid metabolism enzyme activity, increased the mRNA expression of lipid synthesis-related genes, and decreased the mRNA levels of lipidolysis-related genes. In conclusion, the dietary Se supplementation restored antioxidant capacity and mitigated ER stress induced by DOS, thus resisting hepatic lipid metabolism disorders that are associated with regulation of selenotranscriptome.
    Type of Medium: Online Resource
    ISSN: 2076-3921
    URL: Article
    DOI: 10.3390/antiox11030552
    Language: English
    Publisher: MDPI AG
    Publication Date: 2022
    detail.hit.zdb_id: 2704216-9
    SSG: 15,3
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