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Remote sensing is widely used for lake-water-quality monitoring, but the inversion of the total nitrogen (TN) and total phosphorus (TP) of rivers and non-optical parameters is still a difficult problem. The use of high spatial and temporal resolution multispectral imagery combined with machine learning techniques is an effective solution for this difficulty. Three machine learning methods based on support vector regression (SVR), neural network (NN) and random forest (RF) were used to invert TN and TP using actual water-quality measurement data and Sentine-2 remote-sensing images, and analyzed the factors influencing water quality in terms of pollutant emissions and land use. The results show that RF performs the best in both TN (R2 = 0.800, RMSE = 0.640, MSE = 0.400, MAE = 0.480) and TP (R2 = 0.830, RMSE = 0.033, MSE = 0.001, MAE = 0.022) inversion models, and that the optimal selection of feature variables improves model performance. The TN and TP concentrations in the Minjiang River Meishan Water Function Development Zone were the highest in the downstream section and in 2018. Analysis of the factors influencing water quality shows that pollution sources and amounts were closely related to land-use types, and land use in riparian zones at different spatial scales had different degrees of impact on water quality.

The nervous system of the silkworm is vital for the development of organisms. It achieves and maintains normal life activities by regulating the function of the organs and all kinds of physiological processes in the silkworm. BmApontic (BmApt), as an important bZIP transcription factor, is required for the formation of pigmentation in the silkworm. However, the function of BmApt in the development of the nervous system of the silkworm remains unclear. Here, we showed that amino acid sequence of BmApt was evolutionarily conserved in its Myb/SANT motif and basic DNA binding domain. BmApt was expressed in the nervous system at the embryonic stage. Knockdown of Bmapt by RNA interference resulted in abnormal development of axons. Moreover, the expression of BmnetrinA, BmnetrinB and Bmfrazzled was decreased in the Bmapt knockdown embryos. These results demonstrate that BmApt controls neurodevelopment by activating the expression of Bmnetrin and Bmfrazzled.

Imidacloprid, a widely used neonicotinoid insecticide, is toxic to silkworm (Bombyx mori). To explore whether N-acetyl-l-cysteine (NAC) has an effect on preventing silkworm (B. mori) from toxification caused by imidacloprid, we fed the fifth-instar larvae with mulberry leaves dipped in 200 mg/L NAC solution before exposing in imidacloprid, and investigated the silkworm growth, survival rate, feed efficiency, cocoon quality, and the activities of antioxidant enzymes in midgut. The results showed that addition of NAC could significantly increase body weight, survival rate, and feed efficiency of imidacloprid poisoned silkworm larvae (P < 0.05), as well as cocoon mass, cocoon shell mass, and the ratio of cocoon shell (P < 0.05). Furthermore, it could significantly promote the activities of the antioxidant enzymes including superoxide dismutase, catalase, and glutathione peroxide in the midgut of fifth-instar larvae under imidacloprid exposure at the late stage of treatment. In addition, it also could downregulate the malondialdehyde content. The results of our findings proved that the added NAC may have some beneficial effects on protection or restoration of antioxidant balance in imidacloprid exposed larvae.

Co(II)-catalyzed C–H C2 selective arylation of indoles with boronic acids through monodentate chelation assistance has been achieved for the first time. The unique features of this methodology include mild reaction conditions, highly C2 regioselectivity, and employment of a Grignard reagent-free catalytic system. A wide range of substrates, including unreactive arenes, are well tolerated, which enables the construction of the coupling products efficiently. This new strategy provides an alternative and versatile approach to construct biaryls using inexpensive cobalt catalyst.

Mulberry leaf is a traditional medicine used to treat diabetes in the clinic. The aim of this study was to determine the mechanisms by which mulberry leaf polysaccharide (MLPII), improves hepatic glucose metabolism and insulin resistance in rats with type 2 diabetes induced by high fat and streptozotocin (STZ). MLPII was administered for 6 weeks after establishment of type 2 diabetes in Wistar rats. At the end of the experiment, oral glucose tolerance, liver glycogen content, glucose synthase (GS) activity and insulin resistance were determined. Expression patterns of proteins and genes associated with insulin signaling as well as biomarkers of oxidative stress and antioxidant enzyme activities were assayed. Compared with normal control rats, MLPII treatment significantly improved oral glucose tolerance (P < 0.01) and restored the glycogen level (P < 0.01) and GS activity (P < 0.05) in diabetic rats. Insulin resistance was improved in MLPII-treated diabetic rats (P < 0.01). Furthermore, expression levels of insulin receptor substrate 2 (IRS2), phosphatidylinositol 3-kinase (PI3K) and protein kinase B (PKB/AKT) involved in insulin signaling were significantly increased (P < 0.01), while protein–tyrosine phosphatase 1B (PTP1B) expression was markedly reduced (P < 0.01). The levels of 8-hydroxy-2-deoxyguanosine (8-OHdG) and malondialdehyde (MDA) in livers of the MLPII-treated group were significantly reduced (P < 0.01), while activities of the antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), were significantly increased (P < 0.01, P < 0.01, P < 0.01, respectively). The results clearly indicate that MLPII treatment effectively normalizes hepatic glucose metabolism and insulin signaling by inhibiting the expression of PTP1B, activating the PI3K–AKT pathway and mitigating oxidative stress in the livers of rats with type 2 diabetes induced by high fat and STZ.