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Epidemiological studies have shown that exposure to ambient fine particulate matter (PM 2.5 ) is associated with an increased risk for cardiopulmonary diseases. The MEK5/ERK5 and NF-κB signaling pathways are closely related to the regulation of acute pulmonary cell injury (APCI) and may play an important role in the underlying pathophysiological mechanisms. Related studies have shown that Biochanin A (BCA) effectively interferes with APCI, but the underlying mechanism through which this occurs is not fully understood. Previously, based on proteomic and bioinformatic research, we found the indispensable role of MEK5 in mediating remission effects of BCA against PM 2.5 -induced lung toxicity. Therefore, using A549 adenocarcinoma human alveolar basal epithelial cells (A549 cells), we combined western blot and qRT-PCR to study the protective signaling pathways induced by BCA, indicating that MEK5/ERK5 and NF-κB are both involved in mediating APCI in response to PM 2.5 , and MEK5/ERK5 positively activated NF-κB and its downstream cellular regulatory factors. BCA significantly suppressed PM 2.5 -induced upregulation of MEK5/ERK5 expression and phosphorylation and activation of NF-κB. Furthermore, due to the specificity of the MEK5/ERK5 protein structure, the binding sites and binding patterns of BCA and MEK5 were analyzed using molecular docking correlation techniques, which showed that there are stable hydrogen bonds between BCA and the PB1 domain of MEK5 as well as its kinase domain. BCA forms a stable complex with MEK5, which has potential effects on MEKK2/3-MEK5-ERK5 ternary interactions, p62/αPKC-mediated NF-κB regulation, and inhibition of MEK5 target protein phosphorylation. Therefore, our study suggests that MEK5 is an important regulator of intracellular signaling of APCI in response to PM 2.5 exposure. BCA may exert anti-APCI activity by targeting MEK5 to inhibit activation of the MEK5/ERK5/NF-κB signaling pathway.

Aflatoxin B1(AFB1) is one of the most toxic mycotoxins produced by fungi and results in inevitable contamination of food and feed at very low concentrations. Therefore, there is an urgent need to implement selective, sensitive and highly convenient methods for the determination of aflatoxin B1. Among these methods, the progress of nanomaterials, owing to their high performances and versatile properties, offers great prospects for realizing highly sensitive, selective and simple detection of AFB1, overcoming the restrictions of traditional methods such as process-complicated, time-consuming, labor-intensive and instruments-expensive. Many nanomaterials have been used for the immobilization of biomolecules as signal generators or fluorescent quenchers or for signal amplification in AFB1 detection. This review highlights recent progress that has been made in the development of nanoparticle-based assays and focuses on the analytical potential of nanomaterials, such as Au/Ag nanoparticles (Au/Ag NPs), carbon-based nanoparticles (CBNs), magnetic nanoparticles (MNPs), Quantum dots (QDs) and novel nanomaterials, including up-conversion nanoparticles (UCNPs), metal-organic frameworks (MOFs) and nanomaterial-functional DNA intelligent hydrogels, as well as hybrid nanostructures. The determination of AFB1 is divided into three aspects: sample pretreatment prior to AFB1 detection, immunoassays and biosensors. The details of the detection methods and their application principles are described, and the challenges and opportunities in the field of food analysis are described., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Haze pollution has become a global environmental problem, subsequently affecting air quality, climate, economy and human health. Notably, PM 2.5 (particulate matter with an aerodynamic diameter less than 2.5 micrometers) significantly accounts for a variety of adverse health effects, in particular pulmonary diseases such as asthma and lung cancer. Clinical diagnosis and medical treatment of the lung damage caused by PM 2.5 still remain significant challenges due to the lack of specific biomarkers and pathways. Here, we established a rat model of nonsurgical intratracheal instillation to investigate PM 2.5 exposure and employed iTRAQ based analytical technique and bioinformatics tools to identify putative biomarkers and pathways. We identified 163 differentially expressed proteins (DEPs). Among these proteins, we screened six DEPs (HMOX1, MP2K5, XRCC1 E9PTZ7, KNT2 and A1AG) as the putative biomarkers, with significant differentially expressed levels (percentage increment > 140%). Pathway analysis indicated that calcium signaling, MAPK and PI3K/AKT might be involved in the process of PM 2.5 -induced lung damage. Western-blotting was used to verify DEPs in the AEC-II cell model for early diagnosis. In summary, our data can serve as fundamental research clues for further studies of PM 2.5 -induced toxicity in the lungs., Competing Interests: The authors declare no competing financial interests., (This journal is © The Royal Society of Chemistry.)

In this study, the chitosan, chitosan/nano-TiO 2 and chitosan/nano-SiO 2 coating films were prepared, their physico-chemical properties were determined. Then the preservation of Ginkgo biloba seeds coating with these films were investigated during storage. The incorporation of nano-TiO 2 and nano-SiO 2 particles of the best formula enhanced the mechanical properties of the composite films, which improved the water-vapor and gas permeability. Chitosan coating incorporation of nano-TiO 2 and nano-SiO 2 particles could significantly decrease the decay rate, shrinkage rate, respiration rate, ethylene production rate, electrolyte leakage rate, superoxide anion (O 2 ·- ) production rate and the accumulation of malondialdehyde (MDA) content. After storage, the firmness of G. biloba seeds coated with chitosan alone and chitosan/nanocomposite were markedly higher than those of control. Higher activities of scavenger antioxidant enzymes including peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) were enhanced in the chitosan/nano-TiO 2 and chitosan/nano-SiO 2 coating treatments during storage time. Either the composite treatment of chitosan with nano-TiO 2 or chitosan/nano-SiO 2 exhibited desirable performance in inhibiting mildew occurrence, shrinkage and maintaining the firmness of G. biloba seeds, positively affect the antioxidant activity in G. biloba seeds, thereby leading to the enhancement of seed quality. Coating G. biloba seeds with chitosan/nano-TiO 2 or chitosan/nano-SiO 2 is a potential method for commercial preservation., (Copyright © 2018. Published by Elsevier B.V.)

The color change of the jujube fruit after harvest is used as a quality indicator. The effects of abscisic acid (ABA) and a chitosan/nano-silica/sodium alginate composite film on the color development and qualitative properties of harvested jujube in cold storage were investigated. The results indicate that a composite film could prolong the shelf life of post-harvested winter jujube for approximately 1 month, while the ABA treatment induced ripening and reduced the quality. A significant positive correlation between the a∗/b∗ values, water loss and the malondialdehyde (MDA) content was found for fruits in cold storage. In comparison with the control and ABA-treated fruit, superoxide dismutase (SOD), polyphenol oxidase (PPO) and peroxidase (POD) activities were lower than those in a composite film-treated fruit. In addition, the dihydroflavonol-4-reductase (DFR) is the primary gene that regulates the expression of anthocyanin., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Food safety always remains a grand global challenge to human health, especially in developing countries. To solve food safety pertained problems, numerous strategies have been developed to detect biological and chemical contaminants in food. Among these approaches, nanomaterials-based biosensors provide opportunity to realize rapid, sensitive, efficient and portable detection, overcoming the restrictions and limitations of traditional methods such as complicated sample pretreatment, long detection time, and relying on expensive instruments and well-trained personnel. In this review article, we provide a cross-disciplinary perspective to review the progress of nanomaterials-based biosensors for the detection of food contaminants. The review article is organized by the category of food contaminants including pathogens/toxins, heavy metals, pesticides, veterinary drugs and illegal additives. In each category of food contaminant, the biosensing strategies are summarized including optical, colorimetric, fluorescent, electrochemical, and immune- biosensors; the relevant analytes, nanomaterials and biosensors are analyzed comprehensively. Future perspectives and challenges are also discussed briefly. We envision that our review could bridge the gap between the fields of food science and nanotechnology, providing implications for the scientists or engineers in both areas to collaborate and promote the development of nanomaterials-based biosensors for food safety detection., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Senescence is the terminal stage of plant development. It is a strategic and tactical response to seasonal and unpredictable stresses. As an important part of plant senescence, fruit ripening is normally viewed distinctly as climacteric or non-climacteric. In this chapter we describe protocols for the determination of a number of parameters that have been used in characterizing the ripening behavior of fruits. These include changes in respiratory rate, ethylene, flesh firmness, sugar, acidity, starch, pectin, enzymes, aroma volatiles, and expression of ripening-related genes during fruit ripening and senescence.