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BACKGROUND: Camptothecin (CPT) and matrine (MAT) have potential as botanical pesticides against several pest species. However, the mechanisms of metabolic and physiological changes in pests induced by CPT and MAT are unknown. In this study, a toxicological test, an NMR-based metabolomic study, an enzymatic test, and an RT quantitative PCR (RT-qPCR) experiment were all conducted to examine the effect of CPT and MAT on Spodoptera litura. RESULTS: CPT (0.5-1%) exerted high toxicity against larvae of S. litura and caused growth stagnation and high mortality of larvae. A variety of metabolites were significantly influenced by 0.5% CPT, including several energy-related metabolites such as trehalose, lactate, succinate, citrate, malate, and fumarate. In contrast, MAT showed low toxicity against larvae and induced almost no changes in hemolymph metabolites of S. litura. Enzymatic tests showed that trehalase activity was significantly decreased in larvae after feeding with 0.5% CPT. RT-qPCR showed that the transcription levels of alanine aminotransferase, malate dehydrogenase, and isocitrate dehydrogenase were decreased while lactate dehydrogenase was increased in the 0.5% CPT-treated group. CONCLUSIONS: These data indicate that one of the important mechanisms of CPT against S. litura larvae is via the inhibition of trehalose hydrolysis and glycolysis. Our findings also suggest that CPT exhibits a stronger toxicological effect than MAT against S. litura, which provides basic information for the application of CPT in the control of S. litura or other lepidoptera pests.

cancer heterogeneity has been proposed to be one of the main causes of metastatic dissemination and therapy failure. However, the underlying mechanisms of this phenomenon remain poorly understood. Melanoma is an aggressive malignancy with a high heterogeneity and metastatic potential. Therefore, the present study investigated the possible association between cancer heterogeneity and metastasis in melanoma. In total, two novel chinese oral mucosal melanoma (cOMM) cell lines, namely cOMM-1 and cOMM-2, were established for exploring methods into preventing the loss of cellular heterogeneity caused by long-term cell culture. Each cell line was grown under two different models of culture, which yielded two subtypes, one exhibited an adhesive morphology (cOMM-Ad), whereas the other was grown in suspension (cOMM-SUS). compared with the cOMM-Ad cells, the cOMM-SUS cells exhibited higher metastatic capacities and autofluorescence. Further investigations indicated that the cOMM-SUS cells exhibited metabolic reprogramming by taking up lactate produced by cOMM-Ad cells at increased levels to accumulate NAdH through monocarboxylate transporter 1, whilst also increasing NAdPH levels through the pentose phosphate pathway (PPP). Additionally, increased NAdH and NAdPH levels in the cOMM-SUS cells, coupled with the upregulation of the anti-ferroptotic proteins, glutathione peroxidase 4 and ferroptosis suppressor protein 1, enabled them to resist ferroptotic cell death induced by oxidative stress during hematogenous dissemination. The inhibition of ferroptosis was found to substantially increase the metastatic capacity of cOMM-Ad cells. Furthermore, suppressing lactate uptake and impairing PPP activation significantly decreased the metastatic potential of the cOMM-SUS cells. Thus, the present study on metabolic heterogeneity in cOMM cells potentially provides a novel perspective for exploring this mechanism underlying cancer metastasis.

Parallel-connected converters are commonly used in applications such as DC microgrids. The presence of multiple converters allows for the use of the interleaving technique to minimize bus ripple. Most existing interleaving methods rely on communication lines, which are unsuitable for distributed scenarios. This paper presents a method that requires no communication line. The elimination of communication lines reduces the system’s complexity and cost while improving its reliability. We provide an analytical guarantee of stability and validate the control method using phasor simulation and an experimental prototype with three 24 V to 8 V DC-DC buck converters connected in parallel. Measurements show that the proposed method allows the parallel system to maintain an interleaved state in the face of load steps and converters plugged in and out.