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2, 6-diisopropylaniline (2, 6-DIPA) is a crucial non-intentionally organic additive that allows the assessment of the production processes, formulation qualities, and performance variations in biodegradable mulching film. Moreover, its release into the environment may have certain effects on human health. Hence, this study developed simultaneous heating hydrolysis–extraction and amine switchable hydrophilic solvent vortex-assisted homogeneous liquid–liquid microextraction for the gas chromatography–mass spectrometry analysis of the 2, 6-DIPA additive and its corresponding isocyanates in poly(butylene adipate-co-terephthalate) (PBAT) biodegradable agricultural mulching films. The heating hydrolysis–extraction conditions and factors influencing the efficiency of homogeneous liquid–liquid microextraction, such as the type and volume of amine, homogeneous-phase and phase separation transition pH, and extraction time were investigated and optimized. The optimum heating hydrolysis–extraction conditions were found to be a H2SO4 concentration of 2.5 M, heating temperature of 87.8 °C, and hydrolysis–extraction time of 3.0 h. As a switchable hydrophilic solvent, dipropylamine does not require a dispersant. Vortex assistance is helpful to speed up the extraction. Under the optimum experimental conditions, this method exhibits a better linearity (0.0144~7.200 μg mL−1 with R = 0.9986), low limit of detection and quantification (0.0033 μg g−1 and 0.0103 μg g−1), high extraction recovery (92.5~105.4%), desirable intra- and inter-day precision (relative standard deviation less than 4.1% and 4.7%), and high enrichment factor (90.9). Finally, this method was successfully applied to detect the content of the additive 2, 6-DIPA in PBAT biodegradable agricultural mulching films, thus facilitating production process monitoring or safety assessments. [ABSTRACT FROM AUTHOR]

The moisture content of cigar leaves during drying is an important indicator for controlling the management of drying rooms. At present, the determination of cigar leaf moisture content is mainly dependent on traditional destructive detection methods, which are inefficient and damaging to plants. In this study, a Convolution Neural Network method consisting of digital images for monitoring the moisture content of cigar leaves during the drying process was proposed. In this study, the Convolution Neural Network model was trained to learn the relationship between the images and the corresponding moisture content using the extracted colour, shape, and texture features as input factors. In order to compare the Convolution Neural Network estimation results, a widely used traditional machine learning algorithm was applied. The results demonstrated that the estimated value of Convolution Neural Network agreed with the predicted value; the R² was 0.9044, and the average accuracy was 87.34%. These results were better than those produced by traditional machine learning methods. The generalization test of the proposed method was conducted using varieties of cigar leaves in other drying rooms. The results showed that Convolution Neural Network is a viable method for an accurate estimation of the moisture content, the R² was 0.8673 and the average accuracy was 86.81%. The Convolution Neural Network established by the features extracted from digital images could accurately estimate the moisture content of cigar leaves during drying and was therefore shown to be an effective monitoring tool. [ABSTRACT FROM AUTHOR]

The human oral cavity provides a habitat for oral microbial communities. The complexity of its anatomical structure, its connectivity to the outside, and its moist environment contribute to the complexity and ecological site specificity of the microbiome colonized therein. Complex endogenous and exogenous factors affect the occurrence and development of the oral microbiota, and maintain it in a dynamic balance. The dysbiotic state, in which the microbial composition is altered and the microecological balance between host and microorganisms is disturbed, can lead to oral and even systemic diseases. In this review, we discuss the current research on the composition of the oral microbiota, the factors influencing it, and its relationships with common oral diseases. We focus on the specificity of the microbiota at different niches in the oral cavity, the communities of the oral microbiome, the mycobiome, and the virome within oral biofilms, and interventions targeting oral pathogens associated with disease. With these data, we aim to extend our understanding of oral microorganisms and provide new ideas for the clinical management of infectious oral diseases. [ABSTRACT FROM AUTHOR]

As a platform for enzyme immobilization, metal-organic frameworks (MOFs) can protect enzyme activity from the interference of external adverse environment. Although these strategies have been proven to produce good results, little consideration has been given to the functional similarity of MOFs to the encapsulated enzyme. Here, catalase (CAT) was encapsulated in Fe-BTC with peroxidase-like activity to obtain a stable composite (CAT@Fe-BTC) with synergistic catalytic activity. Depending on the superior selectivity and high catalytic activity of CAT@Fe-BTC, colorimetric sensing for the detection of hydrogen peroxide and phenol was developed. This work demonstrates that the integration of functional MOFs with natural enzyme can be well applied to the construction of efficient catalysts. • MOF with similar functionality to catalase used as an immobilization platform. • The obtained CAT@Fe-BTC composites with synergistic catalytic activity. • The colorimetric sensing platform developed for detecting H2O2 and phenol achieved desired results. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cembranoids were systematically separated by an activity-oriented approach. • Enriched the antifungal, insecticidal, and cytotoxic activities of diverse cembranoids. • Cembranoid activities might be influenced by hydroxyl groups and unsaturation. • Cembranoid kill insects by restraining acetylcholinesterase activity. • Cembranoids are promising for developing bio-pesticides and bio-medicines. Cembranoids are a class of glandular trichome exudates with a variety of structural variations and biological activities, and are found in high quantities in tobacco (Nicotiana tabacum L.). However, few studies have conducted preparative separation and examined the activities of cembranoids other than (1 S ,2 E ,4 S ,6 R ,7 E ,11 E)-2,7,11-cembratriene-4,6-diol (α -CBT-diol, 1) and (1 S ,2 E ,4 R ,6 R ,7 E ,11 E)-2,7,11-cembratriene-4,6-diol (β -CBT-diol, 2); thus, the structure-activity relationship (SAR) of cembranoids remains unclear. Here, to deduce the SAR of cembranoids, raw cembranoid extract was systematically separated through an activity-oriented approach with preparative reversed-phase liquid chromatography. Each fraction was identified, and their antifungal, insecticidal, and cytotoxic bioactivities were evaluated. Composition analysis and activity detection of primary fractions (Fr.1–Fr.10) revealed that cembranoid activity might be influenced by the number of hydroxyl groups and degree of unsaturation (macrocycle and double bonds). Sub-fraction analysis showed that the antifungal activity of cembranoids was related to the number of hydroxyl groups and double bonds, and that their cytotoxic activity was affected by the type and position of substituents. Furthermore, all four factors could influence insecticidal activity. By conducting in-depth studies of single cembranoids, their SARs were summarized. The existence of Δ11,12/Δ7,8 and hydroxylation at C-6/C-4 contributed to the antifungal activity of cembranoids. Variation in the type and position of substituents also significantly affected antifungal activity, of which Δ11,12 was the most influential factor. Additionally, the change in substituent configuration at C-4 and C-12 had no significant effect on antifungal activity. The insecticidal activity of cembranoids benefited from the existence of 4-hydroxyl, which greatly enhanced their binding affinity; however, functional groups substituted at other positions decreased insecticidal activity. Cytotoxic activity was positively correlated with α -configuration at C-4 and hydroxylation at C-6 but inversely correlated with 4-methoxy substitution. Among them, 6-hydroxyl formed the core; the α -/ β -configuration at C-12 and 4-/12-substitution of cembranoids did not affect their insecticidal activity. Insecticidal activity might play a key role by restraining acetylcholinesterase activity through hydrophobic interactions between the cembranoid carbon skeleton and residues located at the acetylcholinesterase binding pocket. These findings may provide a foundation for the development of novel cembranoid-based pesticides and medicines. [ABSTRACT FROM AUTHOR]

Tobacco black shank caused by Phytophthora nicotianae is a devastating disease that causes huge losses to tobacco production across the world. Investigating the regulatory mechanism of tobacco resistance to P. nicotianae is of great importance for tobacco resistance breeding. The jasmonate (JA) signaling pathway plays a pivotal role in modulating plant pathogen resistance, but the mechanism underlying JA-mediated tobacco resistance to P. nicotianae remains largely unclear. This work explored the P. nicotianae responses of common tobacco cultivar TN90 using plants with RNAi-mediated silencing of NtCOI1 (encoding the perception protein of JA signal), and identified genes involved in this process by comparative transcriptome analyses. Interestingly, the majority of the differentially expressed bHLH transcription factor genes, whose homologs are correlated with JA-signaling, encode AtBPE-like regulators and were up-regulated in NtCOI1 -RI plants, implying a negative role in regulating tobacco response to P. nicotianae . A subsequent study on NtbHLH49, a member of this group, showed that it's negatively regulated by JA treatment or P. nicotianae infection, and its protein was localized to the nucleus. Furthermore, overexpression of NtbHLH49 decreased tobacco resistance to P. nicotianae , while knockdown of its expression increased the resistance. Manipulation of NtbHLH49 expression also altered the expression of a set of pathogen resistance genes. This study identified a set of genes correlated with JA-mediated tobacco response to P. nicotianae , and revealed the function of AtBPE-like regulator NtbHLH49 in regulating tobacco resistance to this pathogen, providing insights into the JA-mediated tobacco responses to P. nicotianae ., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Wang, Zhang, Cao, Yang, Wang, Yang and Wang.)

Tobacco contains a large amount of bioactive ingredients which can be used as source of feed. The objective of this study was to evaluate the effects of dietary addition of low-nicotine tobacco (LNT) on the growth performance, blood status, cecum microbiota and metabolite composition of meat rabbits. A total of 80 Kangda meat rabbits of similar weight were assigned randomly as four groups, and three of them were supplemented with 5%, 10%, and 20% LNT, respectively, with the other one fed with basal diet as control group. Each experiment group with 20 rabbits was raised in a single cage. The experiments lasted for 40 days with a predictive period of 7 days. The results revealed that LNT supplementation had no significant effect on the growth performance, but increased the half carcass weight compared with control group. Dietary supplemention of LNT decreased the triglycerides and cholesterol content in rabbit serum, and significantly increased the plasma concentration of lymphocytes (LYM), monocytes, eosinophils, hemoglobin HGB and red blood cells. In addition, LNT supplementation significantly changed the microbial diversity and richness, and metagenomic analysis showed that LNT supplementation significantly increased Eubacterium_siraeum_group , Alistipes , Monoglobus and Marvinbryantia at genus level. Moreover, LC-MS data analysis identified a total of 308 metabolites that markedly differed after LNT addition, with 190 significantly upregulated metabolites and 118 significantly downregulated metabolites. Furthermore, the correlation analysis showed that there was a significant correlation between the microbial difference and the rabbit growth performance. Overall, these findings provide theoretical basis and data support for the application of LNT in rabbits., Competing Interests: The authors declare that this study received funding from Sichuan Tobacco Company and China Tobacco Company. The funders were not involved in the study design, collection, analysis, interpretation of data, the writing of this article, or the decision to submit it for publication., (Copyright © 2022 Jing, Wang, Xie, Zhang, Guo, Tian, Tang, Ju, Wang, Liu, Zhang, Yang and Zhang.)