ABSTRACT
Exploring a cost-effective and high-accuracy optical detection method is of great significance in promoting fruit quality evaluation and grading sales. Apples are one of the most widely economic fruits, and a qualitative and quantitative assessment of apple quality based on soluble solid content (SSC) was investigated via visible (Vis) spectroscopy in this study. Six pretreatment methods and principal component analysis (PCA) were utilized to enhance the collected spectra. The qualitative assessment of apple SSC was performed using a back-propagation neural network (BPNN) combined with second-order derivative (SD) and Savitzky-Golay (SG) smoothing. The SD-SG-PCA-BPNN model's classification accuracy was 87.88%. To improve accuracy and convergence speed, a dynamic learning rate nonlinear decay (DLRND) strategy was coupled with the model. After that, particle swarm optimization (PSO) was employed to optimize the model. The classification accuracy was 100% for testing apples via the SD-SG-PCA-PSO-BPNN model combined with a Gaussian DLRND strategy. Then, quantitative assessments of apple SSC values were performed. The correlation coefficient (r) and root-square-mean error for prediction (RMSEP) in testing apples were 0.998 and 0.112 °Brix, surpassing a commercial fructose meter. The results demonstrate that Vis spectroscopy combined with the proposed synthetic model has significant value in qualitative and quantitative assessments of apple quality.
ABSTRACT
Neuroinflammation and Alzheimer's-related pathology play essential roles in postoperative cognitive dysfunction (POCD). High-mobility group box 1 (HMGB1) is well known as a pivotal mediator in neuroinflammation, and its associations with Alzheimer's-related pathology and POCD have been also revealed. Glycyrrhizin is a nature inhibitor of HMGB1 and is reported with neuroprotective effects through oral administration. Therefore, the present study aims to test the hypothesis that the oral pretreatment of glycyrrhizin prevents POCD by inhibiting HMGB1-induced neuroinflammation and Alzheimer's-related pathology in aged mice. Aged male C57BL/6 mice were subjected to the splenectomy surgery under general anesthesia and the oral pretreatment of glycyrrhizin. The postoperative cognitive changes were evaluated by using Morris water maze (MWM) test. The protein expressions of HMGB1, TLR4, NF-κB, p-Tau, and pro-inflammatory cytokines were determined by Western blot assay. The hippocampal level of ß-amyloid (Aß) was assessed by ELISA assay. We found that the oral pretreatment of glycyrrhizin inhibited HMGB1 cytosolic expression, increased the PSD-95 protein expression, and attenuated the severity of postoperative memory impairment, as indicated by the shorter swimming latency and distance in MWM trials when compared with the mice subjected to the surgery alone. Additionally, the pretreatment of glycyrrhizin reduced the postoperative neuroinflammation (production of pro-inflammatory cytokines including IL-1ß, TNF-α, and IL-6 as well as NF-κB nuclear expression) and Alzheimer's-related pathology (Tau phosphorylation at the site of AT-8 and Ser396 as well as Aß40 and 42 concentrations) in the hippocampus of the aged mice undergoing splenectomy surgery. In conclusion, our results suggest that the oral pretreatment of glycyrrhizin can prevent the postoperative cognitive impairment by reducing neuroinflammation and Alzheimer's-related pathology in the hippocampus of aged mice via HMGB1 inhibition.
