No abstract

This research investigated the influence of selenium nanoparticles (SeNPs) on the reproductive performance of male Sprague-Dawley (SD) rats. A suspension of SeNPs was consecutively administered by oral gavage for 2 weeks at supranutritional (0.2, 0.4, or 0.8 mg Se/kg bw) and nonlethal (2.0, 4.0, or 8.0 mg Se/kg bw) levels to male SD rats. The normal control (NC) rats were exposed to physiological saline alone. Biochemical parameters, sperm motility, gene expression of GPx1 and GPx4, and histopathological evaluation of male spermary were measured in this work. The supranutritional doses could promote the sperm motility (P < 0.001) and movement parameters (P < 0.05). The nonlethal levels of 4.0 and 8.0 mg Se/kg bw reduced the testis weight (P < 0.001), sperm concentration, and motility (P < 0.05), and also caused histopathological injury of testis and epididymis tissues to various degrees. The content of testosterone in serum was increased in the 0.8 group (P < 0.05) and decreased in the 4.0 (P < 0.01) and 8.0 mg Se/kg bw groups (P < 0.001), respectively. No significant effects were observed on antioxidant enzyme activities and mRNA concentration of GPx in the supranutritional dose group, and nonlethal levels were also not observed. In conclusion, SeNPs in the supranutritional dose has a positive effect on the reproductive function of male SD rats and has damaging effect higher than 4.0 mg Se/kg bw.

Based on the homemade flow reaction test platform, the thermolysis and hydrolysis process of urea and its byproducts on the Cu−SSZ-13 catalyst was studied, and the formation rule of gas-phase products in the thermolysis and hydrolysis process was systematically studied. The results show that Cu−SSZ-13 and H−SSZ-13 catalysts have a catalytic hydrolysis effect on urea as well as a slight catalytic thermolysis effect. The intermediate product isocyanate acid is mainly adsorbed on Si and Al active sites of Cu−SSZ-13, while the Cu active site does have an effect on the hydrolysis of HNCO. As a result, the overall decomposition of urea is improved by the Cu−SSZ-13 catalyst, especially at low temperature. Therefore, the Si/Al ratio of the Cu−SSZ-13 catalyst should be reasonably planned in order to make urea decompose completely and reduce the risk of urea deposition.

The study was conducted to evaluate the effects of chromium-loaded chitosan nanoparticles (Cr-CNP) on glucose transporter 4 (GLUT4), relevant messenger RNA (mRNA), and proteins involved in phosphatidylinositol 3-kinase (PI3K), Akt2-kinase, and AMP-activated protein kinase (AMPK) of skeletal muscles in finishing pigs. A total of 120 crossbred barrows (BW 65.00 ± 1.26 kg) were randomly allotted to four dietary treatments, with three pens per treatment and 10 pigs per pen. Pigs were fed the basal diet supplemented with 0, 100, 200, or 400 μg/kg of Cr from Cr-CNP for 35 days. After the feeding trials, 24 pigs were slaughtered to collect longissimus muscle samples for analysis. Cr-CNP supplementation increased GLUT4 messenger RNA (mRNA) (quadratically, P < 0.01) and total and plasma membrane GLUT4 protein contents (linearly and quadratically, P < 0.001) in skeletal muscles. Glycogen synthase kinase 3β (GSK-3β) mRNA was decreased linearly (P < 0.001) and quadratically (P < 0.001). Supplemental Cr-CNP increased insulin receptor (InsR) mRNA quadratically (P < 0.01), Akt2 total protein level linearly (P < 0.01) and quadratically (P < 0.001), and PI3K total protein was increased significantly (P < 0.05) in 200 μg/kg treatment group. The mRNA of AMPK subunit gamma-3 (PRKAG3) and protein of AMPKα was significantly increased (P < 0.001) with the addition of Cr-CNP. The results indicate that dietary supplementation of Cr-CNP may promote glucose uptake by leading to recruitment of GLUT4 to the plasma membrane in skeletal muscles, and these actions may be associated with the insulin signal transduction and AMPK.