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In order to investigate the ballistic performance, failure patterns and energy dissipation of aluminum alloy target plates against the impact of different strength and head shape projectiles, the three-dimensional models of 3 mm thick 6061-T651 aluminum alloy target plates impacted by lightweight-deformable projectiles of different materials were established by Abaqus finite element software, and the modified Johnson-Cook（MJC） constitutive model and the Lode-dependent modified Mhor-Coulomb（MMC） fracture criterion are used for numerical simulation. The results show that the corresponding ballistic limit velocity of the target plates are the highest when the low strength 6061-T651 aluminum alloy are used as the projectile material, and the ballistic limit velocity of the target plates decrease with the increase of the projectiles strength. The impact will cause a more complex failure patterns of the target plates when the projectiles strength is low, and at the same time, the plastic deformation of the projectiles head occur to different degree; the projectiles strength has a significant effect on the energy dissipation ability of the target plates. The ballistic limit velocity corresponding to the lightweight-deformable blunt-head projectiles are higher than that of the ogival-head projectiles.

Although biodiversity and ecosystem functions are strongly shaped by contemporary environments, such as climate and local biotic and abiotic attributes, relatively little is known about how they depend on long-term geological processes. Here, along a 3000-m elevational gradient with tectonic faults on the Tibetan Plateau (that is, Galongla Mountain in Medog County, China), we study the joint effects of geological and contemporary environments on biological communities, such as the diversity and community composition of plants and soil bacteria, and ecosystem functions. We find that these biological communities and ecosystem functions generally show consistent elevational breakpoints at 2000-2800 m, which coincide with Indus-Yalu suture zone fault and are similar to the elevational breakpoints of soil bacteria on another mountain range 1000 km away. Mean annual temperature, soil pH and moisture are the primary contemporary determinants of biodiversity and ecosystem functions, which support previous findings. However, compared with the models excluding geological processes, inclusion of geological effects, such as parent rock and weathering, increases 67.9 and 35.9% of the explained variations in plant and bacterial communities, respectively. Such inclusion increases 27.6% of the explained variations in ecosystem functions. The geological processes thus provide additional links to ecosystem properties, which are prominent but show divergent effects on biodiversity and ecosystem functions: parent rock and weathering exert considerable direct effects on biodiversity, whereas indirectly influence ecosystem functions via interactions with biodiversity and contemporary environments. Thus, the integration of geological processes with environmental gradients could enhance our understanding of biodiversity and, ultimately, ecosystem functioning across different climatic zones.

Metformin, a traditional first-line pharmacological treatment for type 2 diabetes, has recently been shown to have anti-cancer effects on hepatocellular carcinoma (HCC). However, the molecular mechanism underlying the anti-tumor activity of metformin remains unclear. The Sonic hedgehog (Shh) signaling pathway is closely associated with the initiation and progression of HCC. Therefore, the aim of the current study was to investigate the effects of metformin on the biological behavior of HCC and the underlying functional mechanism of metformin in the Shh pathway. HCC was induced in HepG2 cells using recombinant human Shh (rhShh). The effects of metformin on proliferation and metastasis were evaluated using in vitro proliferation, wound healing, and invasion assays. The mRNA and protein expression levels of proteins related to the Shh pathway were measured using western blotting, quantitative PCR, and immunofluorescence staining. Metformin inhibited rhShh-induced proliferation and metastasis. Furthermore, metformin decreased the mRNA and protein expression of Shh pathway components, including Shh, Ptch, Smo, and Gli-1. Silencing of AMPK in the presence of metformin revealed that metformin exerted its inhibitory effects via AMPK. Our findings demonstrate that metformin suppresses the migration and invasion of HepG2 cells via AMPK-mediated inhibition of the Shh pathway. Key words: liver cancer, Sonic hedgehog signaling pathway, metformin, AMPK, HepG2 cells. La metformine, un traitement pharmacologique conventionnel de premiere ligne pour le diabete de type 2, s'est recemment revelee exercer des effets anticancereux sur le carcinome hepatocellulaire (CHC). Cependant, le mecanisme moleculaire de la metformine quant a son activite antitumorale n'est pas encore completement elucide. La voie de signalisation Sonic Hedgehog (Shh) est etroitement associee a l'initiation et a la progression du CHC. Ainsi, l'objectif de la presente etude consistait a examiner les effets de la metformine sur le comportement biologique du CHC et le mecanisme fonctionnel sous-jacent de la metformine sur la voie Shh. Le CHC a ete induit dans les cellules HepG2 par la Shh humaine recombinante (rhShh). Les effets de la metformine sur la proliferation et la metastase ont ete evalues par des tests de proliferation, de cicatrisation et d'invasion in vitro. Les niveaux d'expression de l'ARNm et des proteines liees a la voie Shh ont ete mesures par transfert Western, PCR quantitative et coloration par immunofluorescence. La metformine inhibait la proliferation et la metastase induites par rhShh. En outre, la metformine diminuait l'expression de l'ARNm et des proteines des composants de la voie Shh, notamment Shh, Ptch, Smo et Gli-1. Le silencage de l'AMPK en presence de metformine a revele que la metformine pouvait exercer son effet inhibiteur par l'intermediaire de l'AMPK. Ces resultats demontrent que la metformine peut supprimer la migration et l'invasion des cellules HepG2 par une inhibition de la voie Shh mediee par l'AMPK. [Traduit par la Redaction] Mots-cles : cancer du foie, voie de signalisation Sonic Hedgehog, metformine, AMPK, cellules HepG2., Introduction In 2020, liver cancer was the sixth most commonly diagnosed cancer and the third leading cause of cancer-related deaths worldwide (Sung et al. 2021). The risk factors for liver [...]

Climate change is altering species distribution and modifying interactions in microbial communities. Understanding microbial community structure and their interactions is crucial to interpreting ecosystem responses to climate change. Here, we examined the assemblages of stream bacteria and fungi, and the associations between the two groups along elevational gradients in two regions with contrasting precipitation and temperature, that is the Galong and Qilian mountains of the Tibetan Plateau. In the wetter and warmer region, the species richness significantly increased and decreased with elevation for bacteria and fungi, respectively, while were nonsignificant in the drier and colder region. Their bipartite network structure was also different by showing significant increases in connectance and nestedness towards higher elevations only in the wetter and warmer region. In addition, these correlation network structure generally exhibited similar positive association with species richness in the wetter and warmer region and the drier and colder region. In the wetter and warmer region, climatic change along elevation was more important in determining connectance and nestedness, whereas microbial species richness exerted a stronger influence on network structure and robustness in the drier and colder region. These findings indicate substantial forthcoming changes in microbial diversity and network structure in warming climates, especially in wetter and warmer regions on Earth, advancing the understanding of microbial bipartite interactions' response to climate change. [ABSTRACT FROM AUTHOR]

China has fulfilled the First Centenary Goal of building a moderately prosperous society in all respects. Under such circumstances, thriving businesses play a fundamental and crucial role in comprehensively promoting rural revitalization. As a major sector of modern service industries, tourism actualizes people’s aspirations for a better life. With regard to industrial structure, tourism constitutes a sure path for the revitalization of rural industry and the construction of ecological civilization, and organically integrates the development of the primary, secondary, and tertiary industries in rural areas. As an important Marxist research method, the social-system-based approach establishes a series of materialistic and dialectical methodological principles for the constituent element, functional optimization and formal evolution of the system, and clarifies the direction for the research on the basic laws of social development. For this paper, we have carefully reorganized the existing research findings on rural tourism in China and the world. We then proceed to contextualize rural tourism with a social-system-based approach, theorize the necessity and path of the development of rural tourism in a systematic way, circumstantiate the reality and realization of the current ruraltourism development, and propose policy-related suggestions on the prominent problems in relation to rural tourism in line with four principles, i.e., integrity, structuralism, hierarchy, and openness.

In order to study the ballistic resistance of TC4 titanium alloy under different impact angle,the experimental study on the high velocity impact of hemi-spherical projectile on TC4 titanium alloy target plate by light gas gun was carry out. The ballictic limit and failure mode was obtained. Based on experimental conditions,simulation model and material parameters had been validating through ABAQUS and the influence of impact angle on the ballistic resistance of TC4 titanium alloy had been further analyzing. The research result indicate that the main failure mode of TC4 titanium alloy against hemi-spherical projectile is petal-shaped failure caused by tensile shear and ductile holing; There exists an easiest penetration angle under which the projectile can penetrate the TC4 titanium alloy target most easily; The impact resistance of the target plate is closely related to the failure mode which is different under varying impact angel.