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Acenapththylene-imide (AnI), similar to naphthalene diimide (NDI), is an outstanding building block for organic functional materials and has gained a lot of research attention. Herein, Sulphur and Selenium-embedded AnI-containing polycyclic aromatic hydrocarbon molecules, AnI-SQ and AnI-SeQ, with [1,2,5]thiadiazolo[3,4-g]quinoxaline (SQ) and [1,2,5]selenadiazolo[3,4-g]quinoxaline (SeQ) are designed and synthesized with low-lying LUMO energy levels. The absorption and emission of AnI-SQ and AnI-SeQ displayed a bathochromic shift upon protonation of the C = N bond. Besides, theoretical calculation indicates remarkable rigid planar backbones for both AnI-SQ and AnI-SeQ. Through self-assembly with polymeric Pluronic® F-127, corresponding hydrophilic nanoparticles (NPs) were prepared with low cytotoxicity. And AnI-SQ NPs could be applied for in vitro two-photon fluorescence imaging.

Background Genome-wide functional genetic studies of food-borne pathogens could provide a comprehensive understanding of the mechanisms underline their survival and pathogenesis in the harsh environments during food processing and infections. Traditional methods such as physical mutagenesis, chemical mutagenesis, and labeled DNA fragment insertion mutation techniques are time-consuming, labor-intensive and low precision. Although RNA-Seq and other omics methods enable high-throughput research on a genome-wide scale, the obtained results of gene transcription or expression cannot establish direct causal connection between the genetic determinants and particular functions. Scope and approach Transposon sequencing (Tn-seq) is an emerging microbial functional genomic technology based on transposon mutagenesis and high-throughput sequencing technologies, which is able to quantitatively track millions of independent mutants in a single experiment, and therefore efficiently map the “genotype-phenotype” relationship and the genetic interaction networks of a bacterium. Key findings and conclusions This article summarizes the common types and hazards of food-borne pathogens, the development of Tn-seq technology, and its applications in studying the physiology, pathogenesis, and environmental survival of food-borne pathogens.

The building of a mature material library is critically important for the practical application of any smart responsive optoelectronic materials. For thermochromic luminophores, as an important category of smart materials, however, it remains challenging to achieve this target due to the complexity and limitations of existing construction mechanisms. Here, we propose a simple and efficient strategy for developing a thermochromic luminophore library by exploiting the synergistic effects between peripheral flexible chain-related molecular dynamics and molecular aggregation structure-related luminescence properties of donor–acceptor–donor type luminophores. The strategy provided herein facilitates the construction of a prototype thermochromic material library of 13 dyes with a luminescence color-switching window covering the whole visible region and a wide temperature-response range from 35 °C to 190 °C. Based on this material library and a nano ink preparation method, reversible information displays and twelfth-level data encryptions based on temperature changes are demonstrated.

Root growth relies on both cell division and cell elongation, which occur in the meristem and elongation zones, respectively. SCARECROW (SCR) and SHORT-ROOT (SHR) are GRAS family genes essential for root growth and radial patterning in the Arabidopsis root. Previous studies showed that SCR and SHR promote root growth by suppressing cytokinin response in the meristem, but there is evidence that SCR expressed beyond the meristem is also required for root growth. Here we report a previously unknown role for SCR in promoting cell elongation. Consistent with this, we found that the scr mutant accumulated a higher level of reactive oxygen species (ROS) in the elongation zone, which is probably due to decreased expression of peroxidase gene 3, which consumes hydrogen peroxide in a reaction leading to Casparian strip formation. When the oxidative stress response was blocked in the scr mutant by mutation in ABSCISIC ACID 2 (ABA2) or when the redox status was ameliorated by the upbeat 1 (upb1) mutant, the root became significantly longer, with longer cells and a larger and more mitotically active meristem. Remarkably, however, the stem cell and radial patterning defects in the double mutants still persisted. Since ROS and peroxidases are essential for endodermal differentiation, these results suggest that SCR plays a role in coordinating cell elongation, endodermal differentiation, redox homeostasis and oxidative stress response in the root. We also provide evidence that this role of SCR is independent of SHR, even though they function similarly in other aspects of root growth and development.

The purpose of the paper is to compare hardenability and aging precipitation behaviour of three 7xxx aluminium alloys (7150, 7055 and 7056). The hardenability has been studied by Jominy test. The a...

Near-infrared (NIR) dyes have shown increasing popularity for photothermal cancer therapy. Here, we report the synthesis and photophysical properties of selenadiazolobenzotriazole based organic small molecule NIR dyes SeNz and SeNzBr, both of which demonstrate strong intramolecular charge transfer and an excellent photothermal effect. Through self-assembly, hydrophilic nanoparticles (NPs) SeNz NPs and SeNzBr NPs were prepared by taking DSPE-PEG2000 as the polymer matrix and exhibited excellent photothermal conversion efficiency of 57.4% and 42.5%, respectively. In addition, both NPs displayed excellent photothermal stability and photostability. Furthermore, both NPs show low dark cytotoxicity and high phototoxicity by taking HeLa cells as the model. All results suggest that selenadiazolobenzotriazole based NIR dyes SeNz and SeNzBr are promising for photothermal therapy.

Herein, nickel carbide (Ni3C) nanoparticles were controlled synthesized by decomposing nickel acetylacetonate in oleylamine and oleic acid solvent at a comparatively low temperature of 280 °C. The resultant Ni3C nanoparticles with an average size of 18 nm exhibited large specific surface area and excellent electrical conductivity. And the charge transport during the Li+ intercalation and deintercalation processes can be effectively facilitated by this kind of unique structure. Serving as an anode material in lithium-ion batteries, the Ni3C nanoparticles presented a high stable specific capacity of 390.1 mAh g−1 during 100 cycles at a current density of 0.1 A g−1 and excellent rate performance (e.g. 152.1 mAh g−1 at 5 A g−1). This phenomenon attributed to the advantages of the high intrinsic electrical conductivity and chemical stability of Ni3C. The effective nanostructure of transition metal carbides provides a promising approach to synthesis stable electrode materials for energy and environmental related applications.

Mannosylerythritol lipids-A (MEL-A) is a novel biosurfactant with excellent surface activity and potential biomedical applications. In this study, we explored the antibacterial activity and the underlying mechanisms of MEL-A against the important food-borne pathogen Listeria monocytogenes. The bacterial growth and survival assays revealed a remarkable antibacterial activity of MEL-A. Since MEL-A is a biosurfactant, we examined the cell membrane integrity and morphological changes of MEL-A-treated bacteria by biochemical assays and flow cytometry analysis and electron microscopes. The results showed obvious damaging effects of MEL-A on the cell membrane and morphology. To further explore the antibacterial mechanism of MEL-A, a transcriptome analysis was performed, which identified 528 differentially expressed genes (DEGs). Gene ontology (GO) analysis revealed that the gene categories of membrane, localization and transport were enriched among the DEGs, and the analysis of the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways demonstrated significant changes in the maltodextrin ABC transporter system and stress response system. Furthermore, the growth of L. monocytogenes could also be significantly inhibited by MEL-A in milk, a model of a real food system, suggesting that MEL-A could be potentially applied as an natural antimicrobial agent to control food-borne pathogens in the food industry.

Sesamol, a lignan in sesame, possesses several bioactivities, such as antioxidation, anti-inflammation, and neuroprotective capability. In this study, the effects of sesamol on aging-caused cognitive defects are investigated. Twelve-month-old mice were treated with sesamol (0.1%, w/w) as dietary supplementation for 12 weeks. Behavioral tests revealed that sesamol improved aging-associated cognitive impairments. Sesamol decreased aging-induced oxidative stress via suppression of malondialdehyde production and increased antioxidant enzymes. Histological staining showed that sesamol treatment improved aging-induced neuronal damage and synaptic dysfunction in the hippocampus. Furthermore, sesamol significantly reduced aging-induced neuroinflammation by inhibiting the microglial overactivation and inflammatory cytokine expressions. Meanwhile, the accumulation of Aβ1-42 was reduced by sesamol treatment. Moreover, sesamol protected the gut barrier integrity and reduced LPS release, which was highly associated with its beneficial effects on behavioral and inflammatory changes. In conclusion, our findings indicated that the use of sesamol is feasible in the treatment of aging-related diseases.

It is of great significance to design and synthesize highly efficient n-type organic small molecules as electron-transporting layer (ETL) materials to achieve high performance planar perovskite solar cells (PVKSCs) with low-temperature solution-processing. In this article, acenaphthylene-imide based small molecules AI1, AI2 and AI3 were developed with lower-lying LUMO energy levels and were further applied as non-fullerene ETL materials for solution-processed PVKSCs. When TiO2/AIX bilayer was used as ETL, an average power conversion efficiency (PCE) of 15.0% was achieved for TiO2/AI1 based PVKSCs with conventional configuration, while pristine TiO2 based devices presented a PCE of 11.7% only. All the results demonstrate that acenaphthylene-imide derivatives could be promising ETL materials to accomplish low-temperature solution-processed high performance PVKSCs.

Root growth relies on both cell division and elongation, which occur in the meristem and elongation zones respectively. SCARECROW (SCR) is a GRAS family gene essential for root growth and radial patterning in the Arabidopsis root. Previous studies showed that SCR promotes root growth by suppressing cytokinin response in the meristem, but there is also evidence that SCR expressed beyond the meristem is required as well for root growth. Here we report that SCR promotes root growth by promoting cell elongation through suppression of oxidative stress response and maintenance of redox homeostasis in the elongation zone. In the scr root, a higher level of hydrogen peroxide was detected, which can be attributed to down-regulation of peroxidase gene 3. When stress response was blocked or redox status was ameliorated by the aba2 or upb1 mutation, the scr mutant produced a significantly longer root with longer cells and a larger and mitotically more active meristem, even though the stem cell and radial patterning defects still persisted. We showed that WRKY15, an oxidative responsive gene, was a direct target of SCR down-regulated in the scr mutant, which suggests that SCR has an active role in suppressing oxidative stress response. Since hydrogen peroxide and peroxidases are essential for endodermal differentiation, these results suggest that SCR plays a central role in coordinating cell elongation, endodermal differentiation, redox homeostasis, and oxidative stress response in plant root.One sentence summaryThis study reveals a novel mechanism of root growth regulation, which involves a previously unrecognized role of SCR in regulating cell elongation, endodermal differentiation, and redox homeostasis.

Water splitting is an important approach for energy conversion to obtain hydrogen and oxygen. Apart from solar water splitting, electrochemical method plays a key role in the booming field, and it is urgent to develop novel and efficient catalysts to accelerate water splitting reaction. Recently, newly emerging self-supported materials, especially three dimensional (3D) carbon substrate electrochemical catalysts, have attracted great attention benefiting from their fantastic catalytic performances, such as large surface area, enhanced conductivity, tunable porosity, and so on. This review summarizes the outstanding materials used for hydrogen evolution reaction and oxygen evolution reaction. And catalysts that acted as both anode and cathode in two-electrode systems for overall water splitting are introduced systematically. The opportunities and challenges of 3D carbon substrate materials for electrochemical water splitting are proposed.

Two kinds of fluorescent probes DFBT and DFABT, and their corresponding water-soluble compounds WDFBT and WDFABT, based on the trimers containing a benzo[2,1,3]thiadiazole moiety and two fluorene moieties are synthesized. Their luminescent behavior towards Hg2+ ions and other various metal ions in organic and water solutions are studied in detail via absorption and emission spectroscopy. All these probes show a selective “on–off-type” fluorescent response to Hg2+ ions in solution over other metal ions with a maximum detection limit of 10−7 M. Importantly, the probe type can be changed from irreversible to reversible by altering the bridge mode between the functional units from CC triple bond to C–C single bond. Their detection mechanisms towards Hg2+ are studied in detail via mass spectrometry and Job plots, which are attributed to irreversible chemical reaction for DFABT and WDFABT and a reversible coordination reaction for DFBT and WDFBT respectively. Our research results about this kind of organic fluorescent probe provide valuable information to the future design of practical Hg2+ fluorescent probes.

Co-culturing two or more species has recently been used in fermenting foods for product flavor or safety control. Ethyl carbamate (EC) is a potential carcinogenic compound presented in Chinese yellow rice wine which can be reduced by fermentation starters modification. In this work, the effect of Lactobacillus brevis (L. brevis) on EC in yellow rice wine fermentation with Saccharomyces cerevisiae (S. cerevisiae) was studied and an optimal mixed-culture fermentation method was constructed according to comparative analyses of EC concentration and fundamental quality. EC concentration could be further reduced by 68.4% at most through adding 108 cfu/L L. brevis during S. cerevisiae fermentation. L. brevis also had beneficial influence on hedonic quality of yellow rice wine. Meanwhile, the effect of gallic acid on EC formation in this mixed-culture fermentation system was elucidated. Unfortunately, the coexistence of gallic acid and L. brevis attenuated their inhibitory effect on EC formation.

Graphical abstract, Methicillin-resistant Staphylococcus aureus (MRSA) is drug-resistant and biofilm-forming pathogenic bacteria with severe morbidity and mortality, and has been continuously detected in food products in recent years. Mannosylerythritol lipids (MELs) are novel biosurfactants and perform antibacterial property against gram-positive bacteria. Ultrasound has been applied into food sterilization as non-thermal techniques and has advantage of maintaining food nutrition and flavor over heat pasteurization. In this work, the synergistic treatment of ultrasound and MEL-A was used to combat planktonic cells and biofilm of MRSA. As a result, the combined treatment has exhibited remarkable antibacterial effect proved by enumeration of viable microbes. Furthermore, flow cytometry, scanning electron microscopy and transmission electron microscopy revealed ultrasound has enhanced the inhibitory effect of MEL-A through exacerbating cell membrane damage. On the other hand, the collaborating working modes to eradicate MRSA biofilm were disturbing cell adhesion to surface by MEL-A and destructing mature biofilm mechanically by ultrasound, reaching to over 90% of clearance rate. The findings of this study illustrated the synergistic antimicrobial mechanism of ultrasound and MEL-A treatments, and offered theoretical basis for their potential applications in food preservation.

Sesamol, an antioxidant lignan from sesame oil, possesses neuroprotective bioactivities. The present work was aimed to elucidate the systemic protective effects of sesamol on cognitive deficits and to determine the possible link between gut and brain. Wildtype and ApoE-/- mice were treated with a high-fat diet and sesamol (0.05%, w/v, in drinking water) for 10 weeks. Behavioral tests including Morris-water maze, Y-maze, and elevated plus maze tests indicated that sesamol could only improve cognitive deficits and anxiety behaviors in wildtype. Consistently, sesamol improved synapse ultrastructure and inhibited Aβ accumulation in an ApoE-dependent manner. Moreover, sesamol prevented dietary-induced gut barrier damages and systemic inflammation. Sesamol also reshaped gut microbiome and improved the generation of microbial metabolites short-chain fatty acids. To summarize, this study revealed that the possible mechanism of neuroprotective effects of sesamol might be ApoE-dependent, and its beneficial effects on gut microbiota/metabolites could be translated into neurodegenerative diseases treatment.

Magnetic iron oxide nanomaterials are among the most widely studied candidates for cancer nanomedicine, because of not only their great biocompatibility and abundance of raw materials, but also their diverse physicochemical properties and biological effects. Represented by magnetite and maghemite, various iron oxide‐based magnetic nanomaterials have been developed for cancer diagnosis and treatment. This mini review presents an up‐to‐date overview of magnetic iron oxide‐based cancer nanomedicines with an emphasis on bioimaging and therapy.

Bamboo leaves extract (BLE) contains various effective ingredients, including phenolic compounds. In this study, the effect of BLE on ethyl carbamate (EC) formation was investigated in Chinese yellow rice wine brewing with three different fermentation starters (Saccharomyces cerevisiae, Saccharomyces cerevisiae and Lactobacillus brevis, and Chinese yeast). As a result, BLE showed significant inhibition effect on EC in multi-microbial fermented rice wine, by preventing the reactions between urea/citrulline and ethanol. We found that BLE had influence on arginine transport (GAP1, CAN1, ALP1, and VBA2 gene) in Saccharomyces cerevisiae (S. cerevisiae), which significantly up-regulated arginine uptake gene expression in vacuole (VBA2 gene) so that inhibited arginine metabolism. Besides, the presence of BLE could improve the overall quality of Chinese yellow rice wine. Consequently, it was worthwhile applying BLE to Chinese rice wine fermentation, especially the wine brewing with S. cerevisiae and Lactobacillus brevis starter.

The antimicrobial effects of ultrasonic filed have been studied for years at the phenotypic level, but there is little research to reveal the molecular regulatory mechanisms underlying the phenotypes. In this study, isobaric tag for relative and absolute quantification (iTRAQ) proteome was applied to analyze the regulatory networks of Escherichia coli O157:H7 in response to ultrasonic stress in whole-genome scale. A total of 1856 differentially expressed proteins were identified, of which 1141 were significant up-regulated and 715 down-regulated compared with live control cells. The comprehensive proteome coverage analysis showed that ultrasonic filed influenced various metabolic pathways in Escherichia coli O157:H7 cells. The ultrasound-induced up-regulation of global stress response regulator RpoS, bacterial mechanosensitive channels and SOS response protein RecA were described from the molecular level for the first time. In addition, we proposed a possible action mechanism that the free radicals produced by acoustic cavitation might enter into cells via the activated mechanosensitive channels, leading to the elevated intracellular ROS level and subsequent cell death. Last but not the least, we illustrated the all-or-nothing phenomenon of power ultrasound might due to the destruction of crucial cell defensive systems, including heat shock proteins and oxidative response regulators. These new findings can let us understand the ultrasonic effects more deeply and will contribute to this area.

Recent progress in synthetic nanotechnology and the ancient use of metals in food preservation and the antibacterial treatment of wounds have prompted the development of nanometallic materials for antimicrobial applications1–4. However, the materials designed so far do not simultaneously display antimicrobial activity and the capability of binding and capturing bacteria and spores. Here, we develop a one-step pyrolysis procedure to synthesize monodisperse superparamagnetic nickel colloidal nanocrystal clusters (SNCNCs), which show both antibacterial activity and the ability to bind Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacteria, as well as bacterial spores. The SNCNCs are formed from a rapid burst of nickel nanoparticles, which self-assemble slowly into clusters. The clusters can magnetically extract 99.99% of bacteria and spores and provide a promising approach for the removal of microbes, including hard-to-treat microorganisms. We believe that our work illustrates the exciting opportunities that nanotechnology offers for alternative antimicrobial strategies and other applications in microbiology. Monodispersed superparamagnetic nickel colloidal nanocrystal clusters synthesized by pyrolysis can capture bacteria and bacterial spores and simultaneously exert antimicrobial activity.

Intestinal colonization by antibiotic-resistant Enterococcus faecium is the first step in a process that can lead to infections in hospitalized patients. By comparative genome analysis and subsequent polymerase chain reaction screening, we identified a locus that encodes a putative phosphotransferase system (PTS). The PTS locus was widespread in isolates from hospital outbreaks of infection (84.2%) and nonoutbreak clinical infections (66.0%) but absent from human commensal isolates. Deletion of pstD, which is predicted to encode the enzyme IID subunit of this PTS, significantly impaired the ability of E. faecium to colonize the murine intestinal tract during antibiotic treatment. This is the first description of a determinant that contributes to intestinal colonization in clinical E. faecium strains.

Enterococcus faecium is a commensal of the gastrointestinal tract of humans and animals. Since the 1990s, it has also emerged as a nosocomial pathogen. Little is known about carbon metabolism of E. faecium even though the ability to utilize different sugars could be an important factor in adapting to different ecological niches. In this study we identify an E. faecium gene cluster that is responsible for the metabolism of the α-galactoside sugar raffinose. Phenotypic testing of seven E. faecium isolates of which the genomes were previously sequenced showed that one isolate (strain E980) could grow on raffinose. Genome analysis identified a gene cluster containing two genes encoding α-galactosidases (termed agaA and agaB) that was uniquely present in E980. The agaA and agaB genes were significantly more frequently found in strains that are phylogenetically related to E980 and were more prevalent in surveillance isolates from hospital and community sources than in isolates from clinical infections. Disruption of the α-galactosidase gene agaB, but not of agaA, disabled growth on raffinose in strain E980. In all strains agaA and agaB are carried on megaplasmids that are between 150 and 300 kb in size. Filter-mating experiments showed that the megaplasmid of E980 can be transferred to a plasmidless recipient which then gains the ability to grow on raffinose. The observation that raffinose utilization by E. faecium is a trait carried by megaplasmids indicates that these megaplasmids can have important roles in shaping the competitive fitness of E. faecium in the environment, for example by expanding the metabolic repertoire of this organism.

Enterococcus faecium is a commensal of the mammalian gastrointestinal tract, but is also found in non-enteric environments where it can grow between 10 °C and 45 °C. E. faecium has recently emerged as a multi-drug resistant nosocomial pathogen. We hypothesized that genes involved in the colonization and infection of mammals exhibit temperature-regulated expression control and we therefore performed a transcriptome analysis of the clinical isolate E. faecium E1162, during mid-exponential growth at 25 °C and 37 °C. One of the genes that exhibited differential expression between 25 °C and 37 °C, was predicted to encode a peptidoglycan-anchored surface protein. The N-terminal domain of this protein is unique to E. faecium and closely related enterococci, while the C-terminal domain is homologous to the Streptococcus agalactiae surface protein BibA. This region of the protein contains proline-rich repeats, leading us to name the protein PrpA for proline-rich protein A. We found that PrpA is a surface-exposed protein which is most abundant during exponential growth at 37 °C in E. faecium E1162. The heterologously expressed and purified N-terminal domain of PrpA was able to bind to the extracellular matrix proteins fibrinogen and fibronectin. In addition, the N-terminal domain of PrpA interacted with both non-activated and activated platelets.

Enterococcus faecium is a gut commensal of humans and animals. In the intestinal tract, E. faecium will have access to a wide variety of carbohydrates, including maltodextrins and maltose, which are the sugars that result from the enzymatic digestion of starch by host-derived and microbial amylases. In this study, we identified the genetic determinants for maltodextrin utilization of E. faecium E1162. We generated a deletion mutant of the mdxABCD-pulA gene cluster that is homologous to maltodextrin uptake genes in other Gram-positive bacteria, and a deletion mutant of the mdxR gene, which is predicted to encode a LacI family regulator of mdxABCD-pulA. Both mutations impaired growth on maltodextrins but had no effect on the growth on maltose and glucose. Comparative transcriptome analysis showed that eight genes (including mdxABCD-pulA) were expressed at significantly lower levels in the isogenic ΔmdxR mutant strain compared to the parental strain when grown on maltose. Quantitative real-time RT-PCR confirmed the results of transcriptome analysis and showed that the transcription of a putative maltose utilization gene cluster is induced in a semi-defined medium supplemented with maltose but is not regulated by MdxR. Understanding the maltodextrin metabolism of E. faecium could yield novel insights into the underlying mechanisms that contribute to the gut commensal lifestyle of E. faecium.