Thanatin and s-thanatin were insect antimicrobial peptides which have shown potent antimicrobial activities on a variety of microbes. In order to investigate the effect of cations and pH on the activity of these peptides against Gram-negative bacteria and Gram-positive bacteria, the antimicrobial activities of both peptides were studied in increasing concentrations of monovalent cations (K + and Na + ), divalent cations (Ca 2+ and Mg
2+) and H + . The NCCLS broth microdilution method showed that both peptides were sensitive to the presence of cations. The divalent cations showed more antagonized effect on the activity against Gram-negative bacteria than the monovalent cations, since the two peptides lost the ability to inhibit bacterial growth at a very low concentration. In addition, the activities of both peptides tested were not significantly affected by pH. Comparing to studies of other antibacterial peptide activities, our data support a hypothesis that positive ions affect the sensitivity to cation peptides.
Abstract:The uniformity of wheat seed emergence is an important characteristic used to evaluate cultivars, cultivation mode and field management. Currently, researchers typically investigated the uniformity of seed emergence by manual measurement, a time-consuming and laborious process. This study employed field RGB images from unmanned aerial vehicles (UAVs) to obtain information related to the uniformity of wheat seed emergence and missing seedlings. The calculation of the length of areas with missing seedlings in both drill and broadcast sowing can be achieved by using an area localization algorithm, which facilitated the comprehensive evaluation of uniformity of seed emergence. Through a comparison between UAV images and the results of manual surveys used to gather data on the uniformity of seed emergence, the root-mean-square error (RMSE) was 0.44 for broadcast sowing and 0.64 for drill sowing. The RMSEs of the numbers of missing seedling regions for broadcast and drill sowing were 1.39 and 3.99, respectively. The RMSEs of the lengths of the missing seedling regions were 12.39 cm for drill sowing and 0.20 cm 2 for broadcast sowing. The UAV image-based method provided a new and greatly improved method for efficiently measuring the uniformity of wheat seed emergence. The proposed method could provide a guideline for the intelligent evaluation of the uniformity of wheat seed emergence.
Pancreatic cancer is one of the most lethal solid malignancies, with a poor prognosis and a high mortality rate. Pancreatic cancer cells exhibit enhanced glycolysis to maintain their rapid growth. Canagliflozin (CANA) is a sodium-glucose co-transporter 2 inhibitor used for the clinical treatment of diabetes. Recent studies have demonstrated the potential ability of CANA to suppress hepatocellular carcinoma, whereas its therapeutic effects on and mechanisms in pancreatic cancer have rarely been reported. In the present study, the antitumor effects of CANA on pancreatic cancer were investigated. The data obtained indicated that pancreatic cancer growth was effectively suppressed by CANA in a dose-dependent manner, with peak inhibition rates of 54.3 and 57.6% in cultured Capan-1 and PANC-1 cells respectively. The tumor inhibitory rate reached 45.2% in nude mice with PANC-1-derived tumors, suggesting its effective antitumor activity against pancreatic cancer in vitro and/or in vivo. In addition, the combined treatment of Capan-1 and PANC-1 cells with gemcitabine and CANA exhibited a greater efficacy compared with that of treatment with gemcitabine alone. Moreover, glucose uptake and lactate production were decreased, and the mRNA levels of the glycolysis-associated genes, including glucose transporter-1 and lactate dehydrogenase A were decreased, indicating the inhibitory effects caused by the combination treatment on the metabolism of glucose in pancreatic cancer cells. Furthermore, CANA induced apoptosis, notably early apoptosis, and decreased the protein levels of PI3K, p-AKT, p-mTOR and HIF-1α, which indicated that the PI3K/AKT/mTOR signaling pathway was involved in the glycolytic process. These results demonstrated that pancreatic cancer growth was effectively inhibited by CANA via the suppression of glycolysis. This was mediated primarily by the PI3K/AKT/mTOR signaling pathway, revealing the underlying role and potential of this pathway for the clinical treatment of pancreatic cancer. Novel applications for the existing drug CANA can be explored, which could reduce the cost and time required for drug development in the field of drug discovery.
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