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Coating products are widely used for the interior decoration of residential property. However, there is growing concern regarding their odor emissions and their impact on indoor air quality (IAQ). Most manufacturers and government agencies set odor intensity limits to control the odor of coating products, including their raw materials. However, it is difficult to determine product performance by means of their odor intensity index. Although evaluating odor intensity requires odor assessors to distinguish between different intensity levels, low consensus and reproducibility represent challenges that are difficult to avoid. As the odor concentration index only requires odor assessors to ascertain whether the odor is felt or not, the reproducibility of the evaluation results is relatively better. Moreover, suitable methodologies for determining odor concentrations in volatile coating product emissions have rarely been reported. Therefore, establishing an evaluation method for odor concentration of coating products and exploring its key influencing factors should bridge this gap. We examined the influence of the airbag material on the recovery rate of typical volatile organic compounds (VOCs) using direct injection by GC-MS and established that their adsorption effects were in the order: PET > PVF > PTFE. We then explored the influences of the sample curing and odor emission times on odor concentration. The solvent-based and water-based coatings reached equilibrium after 8 h and 16 h curing, respectively, and after 8 h and 12 h odor emission, respectively. The odor concentrations of real coating samples were measured and compared against their odor intensities. The odor concentration method more accurately and reliably discriminated coating products than the odor intensity approach. Thus, to assist manufacturers in improving coating formulations to reduce the odor impact of coating products, we used headspace gas chromatography to determine the odor substances in water- and solvent-based coatings and analyzed the odor contribution of various volatile compounds using the odor activity value (OAV) method. Butyl acetate, ethylbenzene, and 1-methoxy-2-propyl acetate were the key odorants in solvent-based coatings while 1-butanol, ethylbenzene, and butyl acetate were the key odorants in water-based coatings.

Circular RNA (circRNA) is an endogenous biomolecule in eukaryotes. It has tissue- and cell-specific expression patterns and can act as a microRNA sponge or competitive endogenous RNA. Although circRNA has been found in several species in recent years, the expression profiles in fish gonad are still not fully understood. We detected the expression of circRNA in the ovary, testis, and sex-changed gonad of tilapia by high-throughput deep sequencing, and circRNA-specific computing tools. A total of 20,607 circRNAs were obtained, of which 141 were differentially expressed in the testis and ovary. Among these circRNAs, 135 circRNAs were upregulated and 6 circRNAs were downregulated in female fish. In addition, GO annotation and KEGG pathway analysis of the host genes of circRNAs indicated that these host genes were mainly involved in adherens junction, androgen production, and reproductive development, such as ZP3, PLC, delta 4a, ARHGEF10, and HSD17b3. It is worth noting that we found that circRNAs in tilapia gonads have abundant miRNA-binding sites. Among them, 935 circRNAs have a regulatory effect on miR-212, 856 circRNAs have a regulatory effect on miR-200b-3p, and 529 circRNAs have a regulatory effect on miR-200b-5p. Thus, our findings provide a new evidence for circRNA–miRNA networks in the gonads in tilapia.

This study investigated the molecular mechanisms involved in ovarian transcriptomic responses in Nile tilapia under different photoperiod regimes. Histological analysis indicated that ovarian development was significantly affected by photoperiod. The photoperiods tested were as follows: LD (12 h light:12 h dark), LL (24 h light:0 h dark), and DD (0 h light:24 h dark). The longer photoperiod (LL) was shown to induce ovary development earlier than LD and DD. Next, ovary transcriptome levels were sequenced and analyzed. These data indicated that 988, 992, and 1,036 differentially expressed genes (DEGs) were detected by comparing LD–LL, LD–DD, and LL–DD. A number of genes that may be involved in photoperiod-specific regulation of ovarian development were observed. These findings may be useful for investigating the molecular mechanisms underlying light-induced ovarian development in Nile tilapia.

Hypoxia represents a major physiological challenge for prawns and is a problem in aquaculture. Therefore, an understanding of the metabolic response mechanism of economically important prawn species to hypoxia and re-oxygenation is essential. However, little is known about the intrinsic mechanisms by which the oriental river prawn Macrobrachium nipponense copes with hypoxia at the metabolic level. In this study, we conducted gas chromatography-mass spectrometry-based metabolomics studies and assays of energy metabolism-related parameters to investigate the metabolic mechanisms in the hepatopancreas of M. nipponense in response to 2.0 O2/L hypoxia for 6 and 24 h, and reoxygenation for 6 h following hypoxia for 24 h. Prawns under hypoxic stress displayed higher glycolysis-related enzyme activities and lower mRNA expression levels of aerobic respiratory enzymes than those in the normoxic control group, and those parameters returned to control levels in the reoxygenated group. Our results showed that hypoxia induced significant metabolomic alterations in the prawn hepatopancreas within 24 h. The main metabolic alterations were depletion of amino acids and 2-hydroxybutanoic acid and accumulation of lactate. Further, the findings indicated that hypoxia disturbed energy metabolism and induced antioxidant defense regulation in prawns. Surprisingly, recovery from hypoxia (i.e., reoxygenation) significantly affected 25 metabolites. Some amino acids (valine, leucine, isoleucine, lysine, glutamate, and methionine) were markedly decreased compared to the control group, suggesting that increased degradation of amino acids occurred to provide energy in prawns at reoxygenation conditions. This study describes the acute metabolomic alterations that occur in prawns in response to hypoxia and demonstrates the potential of the altered metabolites as biomarkers of hypoxia.