无芒雀麦愈伤组织在氩离子（Ar^＋）注入过程中冻害耐受性研究

以无芒雀麦愈伤组织为研究对象,探讨了甘油处理对愈伤组织在氩离子注入过程中冻害的防护.结果表明:经甘油处理后,当离子注入剂量小于2.6×1015 Ar+·cm-2时,愈伤组织存活率在85%以上,失水率在12%,比未经甘油保护的有大幅度提高,甘油预处理的愈伤组织生长比较正常.注入剂量增加到一定程度,愈伤组织不能继续生长.     

Effect of low light intensity on growth and accumulation of secondary metabolites in roots of Glycyrrhiza uralensis Fisch

Effects of low light intensity on growth and accumulation of secondary metabolites of a medicinal plant Glycyrrhiza uralensis Fisch. were investigated. Hydroponic-cultivated one year-old rhizome seedlings were grown under three low irradiances, 200, 100, and 50 μmol m⁻² s⁻¹ for 135 days. Control plants were cultured under natural light conditions. Low light intensity stress decreased leaf thickness, photosynthesis and biomass, but increased leaf area and chlorophyll concentrations. Low light intensity also significantly increased accumulation of glycyrrhizic acid and liquiritin in the root, while the maximum values of both secondary metabolites were obtained under an irradiance of 100 μmol m⁻² s⁻¹. Concentrations of both secondary metabolites were negatively correlated with root biomass. The results suggested that G. uralensis could endure an environment with low light intensity and suitable light control might increase the secondary metabolite contents within agroforestry systems.     

Threshold dynamics of an infective disease model with a fixed latent period and non-local infections

In this paper, we derive and analyze an infectious disease model containing a fixed latency and non-local infection caused by the mobility of the latent individuals in a continuous bounded domain. The model is given by a spatially non-local reaction–diffusion system carrying a discrete delay associated with the zero-flux condition on the boundary. By applying some existing abstract results in dynamical systems theory, we prove the existence of a global attractor for the model system. By appealing to the theory of monotone dynamical systems and uniform persistence, we show that the model has the global threshold dynamics which can be described either by the principal eigenvalue of a linear non-local scalar reaction diffusion equation or equivalently by the basic reproduction number ${\mathcal{R}_0}$ for the model. Such threshold dynamics predicts whether the disease will die out or persist. We identify the next generation operator, the spectral radius of which defines basic reproduction number. When all model parameters are constants, we are able to find explicitly the principal eigenvalue and ${\mathcal{R}_0}$ . In addition to computing the spectral radius of the next generation operator, we also discuss an alternative way to compute ${\mathcal{R}_0}$ .     

Knockdown of lncRNA MIAT attenuated lipopolysaccharide-induced microglial cells injury by sponging miR-613

Mammalian Genome - Microglia activation and its mediated neuroinflammation play an important role in the pathological process of various central nervous system injuries and diseases. Previous...     

Foliar Spraying of 6-Benzylaminopurine Promotes Growth and Flavonoid Accumulation in Mulberry (Morus alba L.)

Journal of Plant Growth Regulation - Mulberry (Morus alba L.) leaf, a “source of both medicine and food”, contains antioxidant ingredients such as flavonoids, alkaloids and polyphenols....     

Why pendulum symmetry is absent from the cymose partial inflorescences of Cannaceae? Insights into the essential characteristic of cincinni

Journal of Plant Research - In a typical cincinnus, the neighboring two flowers are generally enantiomorphic, which leads to the pendulum symmetry of the entire cyme. While in a two-flowered...     

Hesperetin inhibits foam cell formation and promotes cholesterol efflux in THP-1-derived macrophages by activating LXRα signal in an AMPK-dependent manner

Journal of Physiology and Biochemistry - Cholesterol efflux from macrophages is the first step of reverse cholesterol transport (RCT), whose increase inhibits cholesterol accumulation and foam cell...     

Western-style diet impedes colonization and clearance of Citrobacter rodentium

Western-style diet (WSD), which is high in fat and low in fiber, lacks nutrients to support gut microbiota. Consequently, WSD reduces microbiota density and promotes microbiota encroachment, potentially influencing colonization resistance, immune system readiness, and thus host defense against pathogenic bacteria. Here we examined the impact of WSD on infection and colitis in response to Citrobacter rodentium. We observed that, relative to mice consuming standard rodent grain-based chow (GBC), feeding WSD starkly altered the dynamics of Citrobacter infection, reducing initial colonization and inflammation but frequently resulting in persistent infection that associated with low-grade inflammation and insulin resistance. WSD’s reduction in initial Citrobacter virulence appeared to reflect that colons of GBC-fed mice contain microbiota metabolites, including short-chain fatty acids, especially acetate, that drive Citrobacter growth and virulence. Citrobacter persistence in WSD-fed mice reflected inability of resident microbiota to out-compete it from the gut lumen, likely reflecting the profound impacts of WSD on microbiota composition. These studies demonstrate potential of altering microbiota and their metabolites by diet to impact the course and consequence of infection following exposure to a gut pathogen.