High-Performance Au@Ag Nanorods Substrate for SERS Detection of Malachite Green in Aquatic Products.

In order to improve the detection performance of surface-enhanced Raman scattering (SERS), a low-cost Au@Ag nanorods (Au@Ag NRs) substrate with a good SERS enhancement effect was developed and applied to the detection of malachite green (MG) in aquaculture water and crayfish. By comparing the SERS signal enhancement effect of five kinds of Au@Ag NRs substrates with different silver layer thickness on 4-mercaptobenzoic acid (4-MBA) solution, it was found that the substrate prepared with 100 µL AgNO3 had the smallest aspect ratio (3.27) and the thickest Ag layer (4.1 nm). However, it showed a good signal enhancement effect, and achieved a detection of 4-MBA as low as 1 × 10-11 M, which was 8.7 times higher than that of the AuNRs substrate. In addition, the Au@Ag NRs substrate developed in this study was used for SRES detection of MG in crayfish; its detection limit was 1.58 × 10-9 M. The developed Au@Ag NRs sensor had the advantages of stable SERS signal, uniform size and low cost, which provided a new tool for SERS signal enhancement and highly sensitive SERS detection method development.

Effects of food matrix elements (dietary fibres) on grapefruit peel flavanone profile and on faecal microbiota during in vitro fermentation.

Citrus fruits are a good source of flavanones. The present study aimed to assess the effect of food matrix elements [dietary fibres (DFs)] on the flavanone profile of grapefruit peel (GFP) and on the gut microbiota during in vitro digestion and simulated colonic fermentation. The contents of low-molecular-weight metabolites (dihydrocaffeic acid and 3-phenylpropionic acid) were increased by pectin, konjac and chitosan in medium- and high-viscosity matrices. Compared with the GFP group, the counts of Lactobacillus spp. and Clostridium leptum were significantly increased in medium-viscosity food matrices (konjac and chitosan) (p < 0.05). Moreover, the acetic and propionic acid contents were significantly elevated in the GFP + DF groups after 12 h of fermentation (p < 0.05). GFP flavanones were retained by DF, and the total phenolic content (TPC) and antioxidant potency composite (APC) index decreased during in vitro digestion. These findings indicate that medium-viscosity DFs (konjac and chitosan) could act as key food matrix elements for the retention of polyphenols.

Chlorogenic acid attenuates cadmium-induced intestinal injury in Sprague-Dawley rats.

Chronic exposure to cadmium (Cd) causes remarkable damage to the liver and gastrointestinal tract. Previous studies have revealed that chlorogenic acid (CGA) could improve the intestinal barrier integrity for weaned rats. Hence, this study sought to investigate the protective effects of CGA from pure reagent and sunflower seed extract (SSE) on growth performance, antioxidant indicators, inflammatory biomarkers and intestinal barrier function in Cd treated rats. A total of 32 Sprague-Dawley female rats with similar weights were randomly allotted to four treatments: control, CdCl2 (6 mg/kg BW), co-treatment of Cd (6 mg/kg BW) and pure CGA (50 mg/kg BW), and co-treatment of Cd (6 mg/kg BW) and SSE (50 mg/kg BW) for 14 days. The data indicated that, CGA or SSE with Cd sequestration and good antioxidative ability decreased Cd absorption and accumulation in the jejunum and increased fecal Cd levels in Cd-exposed rats. Compared with the Cd group, co-treatment with CGA or SSE also alleviated inflammation, ameliorated the villus damage, reversed the disruption of tight junctions, and recovered weight gain of rats. These results suggest that CGA or SSE can protect the intestinal barrier, which is related to the alleviation of Cd-induced oxidative stress and growth decrease.

Diagnostic value of negative enrichment and immune fluorescence in situ hybridization for intraperitoneal free cancer cells of gastric cancer.

OBJECTIVE: To explore the intraperitoneal free cancer cell (IFCC) detection value of negative enrichment and immune fluorescence in situ hybridization (NEimFISH) on chromosomes (CEN) 8/17. METHODS: To verify the reliability of NEimFISH, 29 gastric cancer tumors, their adjacent tissues and greater omental tissues were tested. Our study then included 105 gastric cancer patients for IFCC. We defined patients as IFCC-positive if a signal was detected, regardless of the detailed cancer cell numbers. A comparison of clinicopathological features was conducted among IFCC groups. We also compared the diagnosis value and peritoneal recurrence predictive value among different detection methods. The comparison of IFCC number was also conducted among different groups. RESULTS: A cutoff of 2.5 positive cells could distinguish all benign tissue samples and 97% of malignant tissue samples in our study. Compared to intestinal gastric cancer, patients with diffuse gastric cancer tended to have more IFCCs (6 vs. 4, P=0.002). The IFCC counts were often higher in the lymphovascular invasion positive group than negative group (3 vs. 1, P=0.022). All IFCC samples that were considered positive using conventional cytology were also found to be positive using NEimFISH. When compared to conventional cytology and paraffin pathology, NEimFISH had a higher IFCC positive rate (68.9%) and higher one-year peritoneal recurrence predictive value with area under the curve (AUC) of 0.922. CONCLUSIONS: Gastric cancer could be effectively diagnosed by NEimFISH. The IFCC number found using NEimFISH on CEN8/17 is closely associated with Lauren type and vascular invasion of cancer. NEimFISH is a reliable detection modality with a higher positive detection rate, higher one-year peritoneal recurrence predictive value and quantitative features for IFCC of gastric cancer.