Tur\'{a}n numbers of general hypergraph star forests

Let $\mathcal{F}$ be a family of $r$-uniform hypergraphs, and let $H$ be an $r$-uniform hypergraph. Then $H$ is called $\mathcal{F}$-free if it does not contain any member of $\mathcal{F}$ as a subhypergraph. The Tur\'{a}n number of $\mathcal{F}$, denoted by $ex_r(n,\mathcal{F})$, is the maximum number of hyperedges in an $\mathcal{F}$-free $n$-vertex $r$-uniform hypergraph. Our current results are motivated by earlier results on Tur\'{a}n numbers of star forests and hypergraph star forests. In particular, Lidick\'{y}, Liu and Palmer [Electron. J. Combin. 20 (2013)] determined the Tur\'{a}n number $ex(n,F)$ of a star forest $F$ for sufficiently large $n$. Recently, Khormali and Palmer [European. J. Combin. 102 (2022) 103506] generalized the above result to three different well-studied hypergraph settings, but restricted to the case that all stars in the hypergraph star forests are identical. We further generalize these results to general hypergraph star forests.Comment: arXiv admin note: substantial text overlap with arXiv:2001.05631 by other author

Effects of water stress on starch synthesis and accumulation of two rice cultivars at different growth stages

Rice is a water intensive crop and soil water conditions affect rice yield and quality. However, there is limited research on the starch synthesis and accumulation of rice under different soil water conditions at different growth stages. Thus, a pot experiment was conducted to explore the effects of IR72 (indica) and Nanjing (NJ) 9108 (japonica) rice cultivars under flood-irrigated treatment (CK, 0 kPa), light water stress treatment (L, -20 ± 5 kPa), moderate water stress treatment (M, -40 ± 5 kPa) and severe water stress treatment (S, -60 ± 5 kPa) on the starch synthesis and accumulation and rice yield at booting stage (T1), flowering stage (T2) and filling stage (T3), respectively. Under LT treatment, the total soluble sugar and sucrose contents of both cultivars decreased while the amylose and total starch contents increased. Starch synthesis-related enzyme activities and their peak activities at mid-late growth stage increased as well. However, applying MT and ST treatments produced the opposite effects. The 1000-grain weight of both cultivars increased under LT treatment while the seed setting rate increased only under LT3 treatment. Compared with CK, water stress at booting stage decreased grain yield. The principal component analysis (PCA) showed that LT3 got the highest comprehensive score while ST1 got lowest for both cultivars. Furthermore, the comprehensive score of both cultivars under the same water stress treatment followed the trend of T3 > T2 > T1, and NJ 9108 had a better drought-resistant ability than IR72. Compared with CK, the grain yield under LT3 increased by 11.59% for IR72 and 16.01% for NJ 9108, respectively. Overall, these results suggested that light water stress at filling stage could be an effective method to enhance starch synthesis-related enzyme activities, promote starch synthesis and accumulation and increase grain yield

Amphiphilic Dendrimer Doping Enhanced pH-Sensitivity of Liposomal Vesicle for Effective Co-delivery Toward Synergistic Ferroptosis-Apoptosis Therapy of Hepatocellular Carcinoma

International audienceFerroptosis, characterized by the accumulation of reactive oxygen species and lipid peroxides, has emerged as an attractive strategy to reverse drug resistance. Of particular interest is the ferroptosis-apoptosis combination therapy for cancer treatment. Herein, we report a nanoplatform for effective co-delivery of the anticancer drug sorafenib (S) and the ferroptosis inducer hemin (H) toward synergistic ferroptosis-apoptosis therapy of advanced hepatocellular carcinoma (HCC) as a proof-of-concept study. Liposome is an excellent delivery system; however, it is not sufficiently responsive to the acidic tumor microenvironment (TME) for tumor-targeted drug delivery. We therefore developed pH-sensitive vesicles (SH-AD-L) by incorporating amphiphilic dendrimers (AD) into liposomes for controlled and pH-stimulated release of sorafenib and hemin in the acidic TME, thanks to the protonation of numerous amine functionalities in AD. Importantly, SH-AD-L not only blocked glutathione synthesis to disrupt the antioxidant system but also increased intracellular Fe2+ and •OH concentrations to amplify oxidative stress, both of which contribute to enhanced ferroptosis. Remarkably, high levels of •OH also augmented sorafenib-mediated apoptosis in tumor cells. This study demonstrates the power and efficacy of the effective ferroptosis-apoptosis combination therapy, as well as the promise of the AD-doped TME-responsive vesicles for drug delivery in combination therapy to treat advanced HCC