Odor Fingerprinting of Chitosan and Source Identification of Commercial Chitosan: HS-GC-IMS, Multivariate Statistical Analysis, and Tracing Path Study.

Chitosan samples were prepared from the shells of marine animals (crab and shrimp) and the cell walls of fungi (agaricus bisporus and aspergillus niger). Fourier-transform infrared spectroscopy (FT-IR) was used to detect their molecular structures, while headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) was employed to analyze their odor composition. A total of 220 volatile organic compounds (VOCs), including esters, ketones, aldehydes, etc., were identified as the odor fingerprinting components of chitosan for the first time. A principal component analysis (PCA) revealed that chitosan could be effectively identified and classified based on its characteristic VOCs. The sum of the first three principal components explained 87% of the total variance in original information. An orthogonal partial least squares discrimination analysis (OPLS-DA) model was established for tracing and source identification purposes, demonstrating excellent performance with fitting indices R2X = 0.866, R2Y = 0.996, Q2 = 0.989 for independent variable fitting and model prediction accuracy, respectively. By utilizing OPLS-DA modeling along with a heatmap-based tracing path study, it was found that 29 VOCs significantly contributed to marine chitosan at a significance level of VIP > 1.00 (p < 0.05), whereas another set of 20 VOCs specifically associated with fungi chitosan exhibited notable contributions to its odor profile. These findings present a novel method for identifying commercial chitosan sources, which can be applied to ensure biological safety in practical applications.

Hydrogen-rich water alleviates constipation by attenuating oxidative stress through the sirtuin1/nuclear factor-erythroid-2-related factor 2/heme oxygenase-1 signaling pathway.

BACKGROUND: Constipation, a highly prevalent functional gastrointestinal disorder, induces a significant burden on the quality of patients' life and is associated with substantial healthcare expenditures. Therefore, identifying efficient therapeutic modalities for constipation is of paramount importance. Oxidative stress is a pivotal contributor to colonic dysmotility and is the underlying pathology responsible for constipation symptoms. Consequently, we postulate that hydrogen therapy, an emerging and promising intervention, can serve as a safe and efficacious treatment for constipation. AIM: To determine whether hydrogen-rich water (HRW) alleviates constipation and its potential mechanism. METHODS: Constipation models were established by orally loperamide to Sprague-Dawley rats. Rats freely consumed HRW, and were recorded their 24 h total stool weight, fecal water content, and charcoal propulsion rate. Fecal samples were subjected to 16S rDNA gene sequencing. Serum non-targeted metabolomic analysis, malondialdehyde, and superoxide dismutase levels were determined. Colonic tissues were stained with hematoxylin and eosin, Alcian blue-periodic acid-Schiff, reactive oxygen species (ROS) immunofluorescence, and immunohistochemistry for cell growth factor receptor kit (c-kit), PGP 9.5, sirtuin1 (SIRT1), nuclear factor-erythroid-2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1). Quantitative real-time PCR and western blot analysis were conducted to determine the expression level of SIRT1, Nrf2 and HO-1. A rescue experiment was conducted by intraperitoneally injecting the SIRT1 inhibitor, EX527, into constipated rats. NCM460 cells were induced with H2O2 and treated with the metabolites to evaluate ROS and SIRT1 expression. RESULTS: HRW alleviated constipation symptoms by improving the total amount of stool over 24 h, fecal water content, charcoal propulsion rate, thickness of the intestinal mucus layer, c-kit expression, and the number of intestinal neurons. HRW modulated intestinal microbiota imbalance and abnormalities in serum metabolism. HRW could also reduce intestinal oxidative stress through the SIRT1/Nrf2/HO-1 signaling pathway. This regulatory effect on oxidative stress was confirmed via an intraperitoneal injection of a SIRT1 inhibitor to constipated rats. The serum metabolites, ß-leucine (ß-Leu) and traumatic acid, were also found to attenuate H2O2-induced oxidative stress in NCM460 cells by up-regulating SIRT1. CONCLUSION: HRW attenuates constipation-associated intestinal oxidative stress via SIRT1/Nrf2/HO-1 signaling pathway, modulating gut microbiota and serum metabolites. ß-Leu and traumatic acid are potential metabolites that upregulate SIRT1 expression and reduce oxidative stress.

[Assessing Performance of Pollutant Removal from Municipal Wastewater by Physical and Chemical Methods Based on Membranes].

The removal characteristics of various pollution factors in municipal wastewater by membrane-based physical and chemical treatment, especially the enrichment characteristics of dissolved organic matter, were investigated by high performance liquid chromatography and three-dimensional fluorescence spectroscopy. The results showed that the municipal wastewater had a low COD/TN ratio after the treatment. The micro-flocculation filtration mainly enriched the non-dissolvable organic matter in the raw water and aromatic protein substances with relative molecular mass greater than 30 000. The enrichment degree was up to 60.93%, especially for tyrosine-like and tryptophan-like substances. The dissolved organic matter (DOM) with a molecular weight greater than 30 000 was enriched fully by 0.45 µm and 0.22 µm acetate membranes, but the microfiltration membrane was not selective for the enrichment of organic matter. Thus, NF mainly enriched the fulvic acid and humic acid in urban sewage. The enrichment degree was 52.01% and 53.57%, respectively, and the total enrichment degree of dissolved organic matter was about 42%.

Intestinal ischemic preconditioning reduces liver ischemia reperfusion injury in rats.

The aim of the current study was to investigate whether intestinal ischemic preconditioning (IP) reduces damage to the liver during hepatic ischemia reperfusion (IR). Sprague Dawley rats were used to model liver IR injury, and were divided into the sham operation group (SO), IR group and IP group. The results indicated that IR significantly increased Bax, caspase 3 and NF­κBp65 expression levels, with reduced expression of Bcl­2 compared with the IP group. Compared with the IR group, the levels of AST, ALT, MPO, MDA, TNF­α and IL­1 were significantly reduced in the IP group. Immunohistochemistry for Bcl­2 and Bax indicated that Bcl­2 expression in the IP group was significantly increased compared with the IR group. In addition, IP reduced Bax expression compared with the IR group. The average liver injury was worsened in the IR group and improved in the IP group, as indicated by the morphological evaluation of liver tissues. The present study suggested that IP may alleviates apoptosis, reduce the release of pro­inflammatory cytokines, ameloriate reductions in liver function and reduce liver tissue injury. To conclude, IP provided protection against hepatic IR injury.

Clinicopathological Significance of MicroRNA-20b Expression in Hepatocellular Carcinoma and Regulation of HIF-1α and VEGF Effect on Cell Biological Behaviour.

miRNA-20b has been shown to be aberrantly expressed in several tumor types. However, the clinical significance of miRNA-20b in the prognosis of patients with hepatocellular carcinoma (HCC) is poorly understood, and the exact role of miRNA-20b in HCC remains unclear. The aim of the present study was to investigate the association of the expression of miR-20b with clinicopathological characteristics and overall survival of HCC patients analyzed by Kaplan-Meier analysis and Cox proportional hazards regression models. Meanwhile, the HIF-1α and VEGF targets of miR-20b have been confirmed. We found not only miR-20b regulation of HIF-1α and VEGF in normal but also regulation of miR-20b in hypoxia. This mechanism would help the tumor cells adapt to the different environments thus promoting the tumor invasion and development. The whole study suggests that miR-20b, HIF-1α, and VEGF serve as a potential therapeutic agent for hepatocellular carcinoma.

[Registration technology for mandibular angle osteotomy based on augmented reality].

PURPOSE: To establish an effective path to register the operative plan to the real model of mandible made by rapid prototyping (RP) technology. METHODS: Computerize tomography (CT) was performed on 20 patients to create 3D images, and computer aided operation planning information can be merged with the 3D images. Then dental cast was used to fix the signal which can be recognized by the software. The dental cast was transformed to 3D data with a laser scanner and a programmer that run on a personal computer named Rapidform matching the dental cast and the mandible image to generate the virtual image. Then the registration was achieved by video monitoring system. RESULTS: By using this technology, the virtual image of mandible and the cutting planes both can overlay the real model of mandible made by RP. CONCLUSIONS: This study found an effective way for registration by using dental cast, and this way might be a powerful option for the registration of augmented reality. Supported by Program for Innovation Research Team of Shanghai Municipal Education Commission.