N-nitrosodimethylamine exposure to zebrafish embryos/larvae causes cardiac and spinal developmental toxicity.

N-nitrosodimethylamine (NDMA), one of the new nitrogen-containing disinfection by-products, is potentially cytotoxic, genotoxic, and carcinogenic. Its potential toxicological effects have attracted a wide range of attention, but the mechanism is still not sufficiently understood. To better understand the toxicological mechanisms of NDMA, zebrafish embryos were exposed to NDMA from 3 h post-fertilization (hpf) to 120hpf. Mortality and malformation were significantly increased, and hatching rate, heart rate, and swimming behavior were decreased in the exposure groups. The result indicated that NDMA exposure causes cardiac and spinal developmental toxicity. mRNA levels of genes involved in the apoptotic pathway, including p53, bax, and bcl-2 were significantly affected by NDMA exposure. Moreover, the genes associated with spinal and cardiac development (myh6, myh7, nkx2.5, eph, bmp2b, bmp4, bmp9, run2a, and run2b) were significantly downregulated after treatment with NDMA. Wnt and TGF-ß signaling pathways, crucial for the development of diverse tissues and organs in the embryo and the establishment of the larval spine, were also significantly disturbed by NDMA treatment. In summary, the disinfection by-product, NDMA, exhibits spinal and cardiac developmental toxicity in zebrafish embryos, providing helpful information for comprehensive analyses and a better understanding the mechanism of its toxicity.

A comprehensive content analysis of 104 Chinese electronic cigarette manufacturing enterprise official websites.

OBJECTIVE: The goal was to analyse website content of Chinese electronic (e) cigarette manufacturing enterprises and understand the marketing strategies to provide evidence for decision-makers to regulate manufacturers. METHODS: Through QCC.com, one of the largest enterprise information query platforms in China, we identified 104 official manufacturer websites in 2021. A codebook including 6 sections with 31 items was developed and all webpages were coded separately by two trained researchers. RESULTS: Over half of the websites (56.7%) did not have age verification for entry. Thirty-two (30.8%) websites had no restriction for minors to use or purchase e-cigarettes, and 79 (76.0%) had no health warning. Overall, 99 websites (95.2%) displayed their products, and 72 (69.2%) displayed e-flavours. The most frequently used descriptions of products included good taste (68.3%), positive mood (62.5%), leakage resistance (56.7%), enjoyment (47.1%), reduced harm (45.2%), alternatives to cigarettes (43.3%) and long battery life (42.3%). Additionally, 75 websites (72.1%) provided contact information on different channels, including WeChat (59.6%), Weibo (41.3%), Facebook (13.5%), Instagram (12.5%) and brand apps (2.9%). Manufacturers provided investment and franchise information (59.6%) and offline store information (17.3%). In addition, 41.3% websites included content regarding corporate social responsibility. CONCLUSIONS: Chinese e-cigarette manufacturers' official websites have become a platform for presenting product and brand information, establishing online and offline marketing loops, and displaying corporate social responsibility with weak age restrictions on access and a lack of health warnings. The Chinese government should implement strict regulatory measures on e-cigarette enterprises.

A Method for Detecting Antioxidant Activity of Antioxidants by Utilizing Oxidative Damage of Pigment Protein.

A simple and effective method for detecting the antioxidant activity by utilizing oxidative damage of pigment proteins was developed. In this method, phycocyanin and bovine hemoglobin pigment proteins were used as substrates attacked by free radicals; AAPH was used as a free radical initiator; and Trolox as a positive control; and the fermentation products of Lactobacillus plantarum 793, phycocyanin hydrolysates, salmon skin collagen hydrolysates, and synthetic peptides PMRGGYHY and FCVLRP are antioxidants inspected in this study. Because of being attacked by free radicals, the absorbance of the pigment proteins at their characteristic absorption peak changes with time. By recording the time-varying curve at the characteristic absorption peak of the pigment protein in the blank/negative control sample, the Trolox positive control sample, and the samples of inspected antioxidants, the antioxidant activity could be calculated by using the specific equation. The linear detection ranges of Trolox in the phycocyanin assay and the bovine hemoglobin assay were 1-4 µM and 4-24 µM, respectively. Compared with the ORAC assay, the antioxidant activities of the samples measured by this method were slightly lower. The method proposed in this study reflects the protective effects of inspected antioxidants on pigment proteins, which could potentially serve as new biomarkers of oxidative damage processes.

Dataset of response characteristics of H2-producing bacteria consortium to ß-lactams, aminoglycosides, macrolides, quinolones antibiotics.

Antibiotics on H2 producing bacteria shall be considered as being one of the critical elements in biological H2 production utilizing livestock manure as raw resources. Despite the fact that the manure stands a significance role in bio-fermentation, the possibility of antibiotics being contained in excreta shall not be eliminated. Findings of whether the above saying might threaten the safety of bio-H2 production needs to be further studied. The experiment subjects include: six single and three combined antibiotics were tested and analyzed by the application of the gradient experiment method. Along with the H2 production rate, CHO content, pH and OD600 were used to analyze the effects of various antibiotics introduction on the hydrolysis, fermentation and H2 production. To a further extent, four typical representative samples were selected for biodiversity analysis from the single antibiotic experiment groups. Amounting more than 6000 pieces of data were obtained in a series of experiments. Data suggested that remarkable measure of antibiotics have various degrees of H2 production inhibition, while some antibiotics, Penicillin G, Streptomycin Sulfate, and their compound antibiotics, could promote the growth of Ethanoligenens sp. and improve H2 yield in the contrary. Correspondent to the transition of key metabolic intermediates and end products, the mechanism of each antibiotic type and dose on H2 production were summarized as follows: the main inhibitory mechanisms were: (1) board-spectrum inhibition, (2) partial inhibition, (3) H2 consumption enhancement; and the enhancement mechanisms were: (1) enhance the growth of H2-producing bacteria, (2) enhanced starch hydrolysis, (3) inhibitory H2 consumption or release of acid inhibition. Meanwhile, data analysis found that the effect of antibiotics on H2 producing was not only related to type, but also to dosage. Even one kind of antibiotic may have completely opposite effects on H2-producing bacteria under different dosage conditions. Inhibition of H2 yield was highest with Levofloxacin at 6.15 mg/L, gas production was reduced by 88.77%; and enhancement of H2 yield was highest with Penicillin G at 7.20 mg/L, the gas production increased by 72.90%.

The response regularity of biohydrogen production by anthracite H2-producing bacteria consortium to six conventional veterinary antibiotics.

The impact of antibiotics on H2-producing bacteria must be considered in the industrialization of biological H2 production using livestock manure as raw resources. However, whether antibiotics that may be contained in excreta will threaten the safety of biohydrogen production needs to be researched. This study explored the impact characteristics and mechanism of six single antibiotics and three groups of compound antibiotics on H2 production. Experiments confirmed that most antibiotics have different degrees of H2 production inhibition, while some antibiotics, which like Penicillin G, Streptomycin Sulfate, and their compound antibiotics, could promote the growth of Ethanoligenens sp. and improve H2 yield on the contrary. Comprehensive analysis shows that the main inhibitory mechanisms were: (1) board-spectrum inhibition, (2) partial inhibition, (3) H2 consumption enhancement; and the enhancement mechanisms were: (1) enhance the growth of H2-producing bacteria, (2) enhanced starch hydrolysis, (3) inhibitory H2 consumption or release of acid inhibition. Meanwhile, experiment found that the effect of antibiotics on H2 producing was not only related to type, but also to dosage. Even one kind of antibiotic may have completely opposite effects on H2-producing bacteria under different dosage conditions. Inhibition of H2 yield was highest with Levofloxacin at 6.15 mg/L, gas production was reduced by 88.77%; and enhancement of H2 yield was highest with Penicillin G at 7.20 mg/L, the gas production increased by 72.90%. In the selection of raw material, the type and content of antibiotics demand a detailed investigation and analysis to ensure that the sustainability of H2 yield.

Accuracy improvement in plastics classification by laser-induced breakdown spectroscopy based on a residual network.

The whole ecosystem is suffering from serious plastic pollution. Automatic and accurate classification is an essential process in plastic effective recycle. In this work, we proposed an accurate approach for plastics classification using a residual network based on laser-induced breakdown spectroscopy (LIBS). To increasing efficiency, the LIBS spectral data were compressed by peak searching algorithm based on continuous wavelet, then were transformed to characteristic images for training and validation of the residual network. Acrylonitrile butadiene styrene (ABS), polyamide (PA), polymethyl methacrylate (PMMA), and polyvinyl chloride (PVC) from 13 manufacturers were used. The accuracy of the proposed method in few-shot learning was evaluated. The results show that when the number of training image data was 1, the verification accuracy of classification by plastic type under residual network still kept 100%, which was much higher than conventional classification algorithms (BP, kNN and SVM). Furthermore, the training and testing data were separated from different manufacturers to evaluate the anti-interference properties of the proposed method from various additives in plastics, where 73.34% accuracy was obtained. To demonstrate the superiority of classification accuracy in the proposed method, all the evaluations were also implemented by using conventional classification algorithm (kNN, BP, SVM algorithm). The results confirmed that the residual network has a significantly higher accuracy in plastics classification and shows great potential in plastic recycle industries for pollution mitigation.

Antidiabetic Function of Lactobacillus fermentum MF423-Fermented Rice Bran and Its Effect on Gut Microbiota Structure in Type 2 Diabetic Mice.

Rice bran is an industrial byproduct that exerts several bioactivities despite its limited bioavailability. In this study, rice bran fermented with Lactobacillus fermentum MF423 (FLRB) had enhanced antidiabetic effects both in vitro and in vivo. FLRB could increase glucose consumption and decrease lipid accumulation in insulin resistant HepG2 cells. Eight weeks of FLRB treatment significantly reduced the levels of blood glucose and lipids and elevated antioxidant activity in type 2 diabetic mellitus (T2DM) mice. H&E staining revealed alleviation of overt lesions in the livers of FLRB-treated mice. Moreover, high-throughput sequencing showed notable variation in the composition of gut microbiota in FLRB-treated mice, especially for short-chain fatty acids (SCFAs)-producing bacteria such as Dubosiella and Lactobacillus. In conclusion, our results suggested that rice bran fermentation products can modulate the intestinal microbiota and improve T2DM-related biochemical abnormalities, so they can be applied as potential probiotics or dietary supplements.

Impact of Lactobacillus plantarum 423 fermentation on the antioxidant activity and flavor properties of rice bran and wheat bran.

Rice bran (RB) and wheat bran (WB) fermented with L. plantarum 423 had enhanced odor intensity, especially for sulfides and aromatics. The hydroxyl radical-scavenging activity (73.28 ± 3.18%) and oxygen radical-scavenging activity (2.12 ± 0.08 mmol·TE/g) of RB fermentation broth were better than those of WB fermentation broth. Even at 2 µg/ml, the purified antioxidant fractions from the WB fermentation broth showed strong intracellular ROS-scavenging activity in human umbilical vein endothelial cells (HUVECs), and the purified antioxidant fractions (200 µg/ml) from the RB fermentation broth had a good antiaging effect. The dominant antioxidant components in the RB and WB fermentation broths were acids (70.21%) and ketones (10.64%), these components jointly give the RB and WB fermentation broths a variety of antioxidant properties. These results are beneficial for developing RB and WB deep-processing technology and laid the foundation for the preparation of antioxidant fractions with L. plantarum 423.

Purification, Characterization, and Application for Preparation of Antioxidant Peptides of Extracellular Protease from Pseudoalteromonas sp. H2.

The study reported on the isolation of a metalloprotease named EH2 from Pseudoalteromonas sp. H2. EH2 maintained more than 80% activity over a wide pH range of 5-10, and the stability was also nearly independent of pH. Over 65% activity was detected at a wide temperature range of 20-70 °C. The high stability of the protease in the presence of different surfactants and oxidizing agents was also observed. Moreover, we also investigated the antioxidant activities of the hydrolysates generated from porcine and salmon skin collagen by EH2. The results showed that salmon skin collagen hydrolysates demonstrated higher DPPH (1,1-diphenyl-2-picrylhydrazyl) (42.88% ± 1.85) and hydroxyl radical (61.83% ± 3.05) scavenging activity than porcine skin collagen. For oxygen radical absorbance capacity, the hydrolysates from porcine skin collagen had higher efficiency (7.72 ± 0.13 µmol·TE/µmol). Even 1 nM mixed peptides could effectively reduce the levels of intracellular reactive oxygen species. The two types of substrates exerted the best antioxidant activity when hydrolyzed for 3 h. The hydrolysis time and type of substrate exerted important effects on the antioxidant properties of hydrolysates. The hydrolyzed peptides from meat collagens by proteases have good antioxidant activity, which may have implications for the potential application of marine proteases in the biocatalysis industry.

Immune modulation by silencing IL-12 production in dendritic cells using small interfering RNA.

RNA interference is a mechanism of posttranscriptional gene silencing that functions in most eukaryotic cells, including human and mouse. Specific gene silencing is mediated by short strands of duplex RNA of approximately 21 nt in length (termed small interfering RNA or siRNA) that target the cognate mRNA sequence for degradation. We demonstrate here that RNAi can be used for immune modulation by targeting dendritic cell (DC) gene expression. Transfection of DC with siRNA specific for the IL-12 p35 gene resulted in potent suppression of gene expression and blockade of bioactive IL-12 p70 production without affecting unrelated genes or cellular viability. Inhibition of IL-12 was associated with increased IL-10 production, which endowed the DC with the ability to stimulate production of Th2 cytokines from allogenic T cells in vitro. Furthermore, siRNA-silenced DC lacking IL-12 production were poor allostimulators in MLR. IL-12-silenced and KLH-pulsed DC polarized the immune response toward a Th2 cytokine profile in an Ag-specific manner. These data are the first to demonstrate that RNA interference is a potent and specific tool for modulating DC-mediated immune responses.