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Carbonation has been proven to be a promising way to improve the mechanism properties and durability of steel slag products. Carbonic anhydrase (CA) bacteria can promote the early-age carbonation process of γ-dicalcium silicate (γ-C2S), which is one of the main mineral phases of steel slag. In this study, one kind of alkali-resistant CA bacteria was chosen to investigate its effects on the carbonation process of γ-C2S. Results showed that the bacteria could increase the compressive strength of carbonated γ-C2S by 19.0% when compared with carbonated samples without bacteria. The main products of carbonated γ-C2S were vaterite, calcite and silicon dioxide gel. The addition of bacteria could only accelerate the deposition of calcium carbonate, while hardly changing the types and properties of the carbonation products. The accelerated carbonation was found to reduce the inward diffusion of carbon dioxide. In addition, reasons for the decline of the accelerating carbonation effect were explained by X-ray computed tomography testing results. However, CA bacteria could change the morphology of calcium carbonated during the carbonation process of β-C2S and further accelerate the hydration process of β-C2S. The pore structure could also be refined with the incorporation of bacteria.

The mechanism of melatonin (MT) induced chilling tolerance in harvested cucumber fruit was investigated at commercial maturity. In this study, cucumber fruits were treated with 100 µmol L–1 MT at 4°C and 90% relative humidity for 15 d of storage. In comparison with the control, cucumber treatment with MT resulted in reduced chilling injury (CI), decreased electrolyte leakage and enhanced firmness. The fruits treated with MT showed higher chlorophyll contents in storage conditions with suppressed chlorophyllase enzyme activity. MT treatment increased arginine decarboxylase (ADC) and ornithine decarboxylase (ODC) enzyme activities. Moreover, enhanced expression of the Cucumis sativus ADC (CsADC) and C. sativus ODC (CsODC) genes resulted in the accumulation of polyamine contents. Similarly, proline levels exhibited higher levels among treated fruits. Meanwhile, the proline synthesizing enzymes △1-pyrroline-5-carboxylate syntheses (P5CS) and ornithine aminotransferase (OAT) were significantly increased, while a catabolic enzyme of proline dehydrogenase (PDH) activity was inhibited by treatment. In addition, MT induced expression of C. sativus OAT (CsOAT) and C. sativus P5CS (CsP5CS) genes. Cucumber fruits treated with MT also exhibited higher γ-aminobutyric acid (GABA) content by enhanced GABA transaminase (GABA-T) and glutamate decarboxylase (GAD) enzyme activities and a higher C. sativus GAD (CsGAD) gene expression. To sum up, the results show that MT treatment enhanced chilling tolerance, which was associated with the regulation of polyamines, as well as proline and γ-aminobutyric acid.

Objective To identify the potential biomarkers of interstitial cystitis/painful bladder syndrome (IC), a chronic syndrome of bladder-centric pain with unknown etiology that has an adverse impact on quality of life, we analyzed the urine and serum metabolomes of a cohort of IC patients and non-disease controls (NC). Methods Home collection of serum and urine samples was obtained from 19 IC and 20 NC females in the Veterans Affairs (VA) Health Care System. IC was diagnosed independently by thorough review of medical records using established criteria. Biostatistics and bioinformatics analyses, including univariate analysis, unsupervised clustering, random forest analysis, and metabolite set enrichment analysis (MSEA), were then utilized to identify potential IC biomarkers. Results Metabolomics profiling revealed distinct expression patterns between NC and IC. Random forest analysis of urine samples suggested discriminators specific to IC; these include phenylalanine, purine, 5-oxoproline, and 5-hydroxyindoleacetic acid. When these urinary metabolomics-based analytes were combined into a single model, the AUC was 0.92, suggesting strong potential clinical value as a diagnostic signature. Serum-based metabolomics did not provide potential IC discriminators. Conclusion Analysis of serum and urine revealed that women with IC have distinct metabolomes, highlighting key metabolic pathways that may provide insight into the pathophysiology of IC. The findings from this pilot study suggest that integrated analyses of urinary metabolites, purine, phenylalanine, 5-oxoproline, and 5-HIAA, can lead to promising IC biomarkers for pathophysiology of IC. Validation of these results using a larger dataset is currently underway.

Background Heat shock transcription factors (Hsfs) play pivotal roles in plant response to stress. Although glycine betaine (GB) and hot water (HW) treatments are effective in reducing chilling injury (CI), little is known about characterization of Hsfs gene family and their potential roles in alleviating CI by regulating antioxidant system in peach fruit. Results In this study, 17 PpHsfs were identified in peach genome and investigated by using bioinformatics, including chromosomal locations, phylogenetic relationships, gene structure, motifs and promoter analyses. Furthermore, the expression patterns of PpHsfs under GB and HW treatments were investigated. PpHsfs showed different expression patterns in GB- and HW-treated fruit, while most of them were significantly up-regulated by both treatments, especially PpHsfA1a/b, PpHsfA2a, PpHsfA9a and PpHsfB2a/b. Meanwhile, GB and HW treatments induced the higher levels of genes expressions and antioxidant enzymes activities of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) compared to control, contributing to inhibiting hydrogen peroxide (H2 O2 ) accumulation and superoxide anion (O2 .- ) production. Moreover, the correlation analysis between PpHsfs and antioxidant-related genes showed that three PpAPXs were significantly correlated with ten PpHsfs, while PpCAT and PpSOD had no significant correlations with PpHsfs, which indicated that PpAPX might be regulated by PpHsfs. Conclusions Results indicated that GB and HW treatments induced different PpHsfs transcript levels to regulate the antioxidant genes expressions, which might be beneficial to inhibit the accumulation of reactive oxygen species and protect the integrity of cell structure, thus alleviating the development of CI in peach fruit during cold storage. This article is protected by copyright. All rights reserved.

Silicon carbide (SiC) detectors have great potential in nuclear fusion diagnosis and intense irradiation field measurement due to their outstanding irradiation resistance, high charge collection efficiency (CCE), and fast pulse response time. However, the irradiation resistance and the performance degradation of SiC detectors as a result of He ion irradiation remains unclear. In this article, SiC detectors based on 4H-type material with the p-i-n junction structure were prepared, and their I–V characteristics, $\alpha $ -particle spectra, and linearity of energy response were evaluated before and after He ion irradiation at fluences ranging from $1\times 10^{12}$ to $3 \times 10^{15}$ cm−2. The preirradiated SiC detector exhibited low dark current ( $1 \times 10^{12}$ cm−2, detector performance degradation was negligible, with no increase of dark current, CCE decreased to 85%, and a 2.2% degradation of energy resolution. At a fluence of $3 \times 10^{15}$ cm−2, CCE decreased to 19.3%, with an 8.57% degradation in energy resolution, but the dark current was still lower than 2 nA, with good spectra measurement capabilities and high linearity of energy response. These results indicate that the He ion irradiation resistance of 4H-SiC detectors is 104 times greater than silicon (Si) detectors.

Chemical functionalization of endohedral metallofullerenes (EMFs) is essential for the application of these novel carbon materials. Actinide EMFs, a new EMF family member, have presented unique molecular and electronic structures but their chemical properties remain unexplored. Here, for the first time, we report the chemical functionalization of actinide EMFs, in which the photochemical reaction of Th@C3v(8)-C82 and U@C2v(9)-C82 with 2-adamantane-2,3′-[3H]-diazirine (AdN2, 1) was systematically investigated. The combined HPLC and MALDI-TOF analyses show that carbene addition by photochemical reaction afforded three isomers of Th@C3v(8)-C82Ad and four isomers of U@C2v(9)-C82Ad (Ad = adamantylidene), presenting notably higher reactivity than their lanthanide analogs. Among these novel EMF derivatives, Th@C3v(8)-C82Ad(I, II, III) and U@C2v(9)-C82Ad(I, II, III) were successfully isolated and were characterized by UV-vis-NIR spectroscopy. In particular, the molecular structures of first actinide fullerene derivatives, Th@C3v(8)-C82Ad(I) and U@C2v(9)-C82Ad(I), were unambiguously determined by single crystal X-ray crystallography, both of which show a [6,6]-open cage structure. In addition, isomerization of Th@C3v(8)-C82Ad(II), Th@C3v(8)-C82Ad(III), U@C2v(9)-C82Ad(II) and U@C2v(9)-C82Ad(III) was observed at room temperature. Computational studies suggest that the attached carbon atoms on the cages of both Th@C3v(8)-C82Ad(I) and U@C2v(9)-C82Ad(I) have the largest negative charges, thus facilitating the electrophilic attack. Furthermore, it reveals that, compared to their lanthanide analogs, Th@C3v(8)-C82 and U@C2v(9)-C82 have much closer metal–cage distance, increased metal-to-cage charge transfer, and strong metal–cage interactions stemming from the significant contribution of extended Th-5f and U-5f orbitals to the occupied molecular orbitals, all of which give rise to their unusual high reactivity. This study provides first insights into the exceptional chemical properties of actinide endohedral fullerenes, which pave ways for the future functionalization and application of these novel EMF compounds.

Microcystin-LR (MC-LR) generated by cyanobacteria is a kind of potent hepatotoxin, which poses a considerable threat to human health. In the research field of MC-LR removal, the quantitative analysis in a wide concentration range of samples is inevitable. In this paper, we presented the pseudo united use of an Ultra Performance Liquid Chromatography Mass Spectrometry (UPLC-MS) and High Performance Liquid Chromatography system with a Variable Wavelength Ultraviolet Detector (HPLC-VWD) approach to detect MC-LR. The UPLC-MS system was applied to determine MC-LR in trace concentration because of its high sensitivity. However, it is generally believed that the determination of high concentration samples by UPLC-MS will cause problems such as inaccurate quantification and contamination of ion sources. In consequence, the HPLC-VWD was employed to determine the high concentration of MC-LR. The sensitivity, precision and accuracy of the two methods were compared in detail. The linear ranges of UPLC-MS and HPLC-VWD methods were from 0.08 to 10 μg L−1 and 1 to 5000 μg L−1, respectively. The detection and quantification limits of UPLC-MS were 0.03–0.05 μg L−1 and 0.08 μg L−1, and the corresponding two values of HPLC-VWD were 0.6 and 1.0 μg L−1. The recoveries of UPLC-MS and HPLC-VWD were 88.5–106.7% and 98.7–101.6%, with the relative standard deviations of 3.72–5.45% and 0.38–1.69%, respectively. The potential adsorption properties of MC-LR on filter membranes with diverse materials and pore sizes were evaluated and the negative results were obtained. The detection of MC-LR by UPLC-MS was free from matrix effects. The presented UPLC-MS and HPLC-VWD methods were used to analyze the water samples from Erhai Lake, which is located in Dali, Yunnan, China. The results of UPLC-MS analysis indicated that the MC-LR was only identified in water samples of Shuanglang Bay and Xier River, with concentrations of 0.120 and 0.303 μg L−1, whereas MC-LR was not detected by HPLC-VWD.

The aim of this study was to improve the stability of eugenol–casein nanoparticles (EL–CS-NPs) through polyethylene glycol (PEG) modification. The results show that modifying the EL–CS-NPs with PEG after loading with eugenol (EL) gives PEG–EL–CS-NPs, with increased stability. The NPs modified with higher-molecular-weight PEG showed better stability. A CS/PEG ratio of 200 : 1 (w/w) yielded the NPs with the best stability. A PEG20 K–EL–CS-NP dispersion remained stable in cold storage for over one year, and also exhibited stronger inhibitory effects against Colletotrichum musae inoculated on bananas than an EL–CS-NP dispersion, since it showed more prolonged sustained release of EL than the EL–CS-NP dispersion. Lyophilized PEG20 K–EL–CS-NP powder showed better effectiveness against mold on bread than lyophilized EL–CS-NPs powder. Using PEG to modify CS-NPs shows potential for improving the stability of CS-NPs loaded with hydrophobic substances for delivery in the fields of food and agriculture.

The binder phase Co in WC-Co cemented carbide is dissolved easily in corrosive media (even in neutral solution), which has limited its application in a wider range. In this paper, the influence of Cr on corrosion resistance of WC-Co immersed in neutral solution was studied, with a focus on the surface chemistry of the corrosion product. The results show that in neutral solution, the corrosion is mainly caused by the selective dissolution of Co and the dominant surface corrosion product after immersion is Co (OH)(2). The corrosion resistance of WC-Co cemented carbide can be improved by the addition of Cr. This can be explained by the formation of more protective chromium containing oxide on the binder phase of WC-Co-Cr alloy, leading to reduced corrosion rate.

Electrocatalytic nitrogen reduction reaction (NRR) at ambient conditions holds great promise for sustainably synthesizing ammonia (NH3), while developing highly-efficient, long-term stable, and inexpensive catalysts to activate the inert N N bond is a key scientific issue. In this work, on the basis of the concept “N-heterocyclic carbenes (NHCs)”, we propose a carbon decorated graphitic-carbon nitride (C/g-C3N4) as novel metal-free NRR electrocatalyst by means of density functional theory (DFT) computations. Our results reveal that the introduced C atom in g-C3N4 surface can be regarded as NHCs and catalytic sites for activating N N bond, and are stabilized by the g-C3N4 substrate due to sterically disfavored dimerization. Especially, this NHCs-based heterogeneous catalysis can efficiently reduce the activated N2 molecule to NH3 with a low overpotential of 0.05 V via an enzymatic mechanism. Our work is the first report of NHCs-based electrocatalyst for N2 fixation, thus opening an alternative avenue for advancing sustainable NH3 production.

Purpose The use of Aspergillus ochraceus TCCC41060 for synthesis of 11α-OH-ethylgonendione, an important intermediate for synthesis of desogestrel-a major ingredient of the “third-generation” oral contraceptives, is hampered by its low regioselectivity of hydroxylation. In the present study, we sought to characterize gene(s) involved in steroid hydroxylation specificity in strain TCCC41060. Methods Taking advantage of the fact that expression of the 11α-hydroxylase, a member of the cytochrome P450 family, is highly induced by steroid substrates, we combined RNA-seq, qRT-PCR, and yeast functional expression to search for responsible steroid hydroxylase gene(s). Results Two highly inducible P450 genes (CYP68L8 and CYP68J5) were isolated and recombinant yeast cells expressing CYP68J5 were capable of 11α-hydroxylating both 16,17α-epoxyprogesterone and D-ethylgonendione. Disruption of CYP68J5 in strain TCCC41060 resulted in complete loss of hydroxylation activities towards D-ethylgonendione, indicating that CYP68J5 was solely responsible for hydroxylation activity on D-ethylgonendione in TCCC41060. Conclusion The above results demonstrated that low hydroxylation specificity of CYP68J5 on D-ethylgonendione fully accounted for high by-product contents in TCCC41060, thus pointing to a strategy to engineer 11α-hydroxylase variants with higher hydroxylation specificity.

Chemical modification of endohedral metallofullerenes (EMFs) is an efficient strategy to realize their ultimate applications in many fields. Herein, we report the highly regioselective and quantitative mono-formation of pyrazole- and pyrrole-ring-fused derivatives of the prototypical di-EMF Y2 @C3v (8)-C82 , that is, Y2 @C3v (8)-C82 (C13 N2 H10 ) and Y2 @C3v (8)-C82 (C9 NH11 ), from the respective 1,3-dipolar reactions with either diphenylnitrilimine or N-benzylazomethine ylide, without the formation of any bis- or multi-adducts. Crystallographic results unambiguously reveal that only one [6,6]-bond out of the twenty-five different types of nonequivalent C-C bonds of Y2 @C3v (8)-C82 is involved in the 1,3-dipolar reactions. Our theoretical results rationalize that the remarkably high regioselectivity and the quantitative formation of mono-adducts are direct results from the anisotropic distribution of π-electron density on the C3v (8)-C82 cage and the local strain of the cage carbon atoms as well. Interestingly, electrochemical and theoretical studies demonstrate that the reversibility of the redox processes, in particular the reversibility of the reductive processes of Y2 @C3v (8)-C82 , has been markedly altered upon exohedral functionalization, but the oxidative process was less influenced, indicating that the oxidation is mainly influenced by the internal Y2 cluster, whereas the reduction is primarily associated with the fullerene cage. The pyrazole and pyrrole-fused derivatives may find potential applications as organic photovoltaic materials and biological reagents.

N6-methyladenosine (m6A) is a dynamic RNA modification that regulates various aspects of RNA metabolism and has been implicated in many biological processes and transitions. m6A is highly abundant in the brain; however, only recently has the role of m6A in brain development been a focus. The machinery that controls m6A is critically important for proper neurodevelopment, and the precise mechanisms by which m6A regulates these processes are starting to emerge. However, the role of m6A in neurodegenerative and neuropsychiatric diseases still requires much elucidation. This review discusses and summarizes the current body of knowledge surrounding the function of the m6A modification in regulating normal brain development, neurodegenerative diseases and outlines possible future directions.

Although numerous denitrifying bacteria have been isolated and characterized, their capacity is seriously compromised by traditional inoculant addition and environmental stress in open bioreactors for wastewater treatment. In this study, a biocompatible material, chitosan, was used as a carrier to immobilize a simultaneously heterotrophic nitrifying–aerobic denitrifying bacterium Klebsiella sp., KSND, for continuous nitrogen removal from domestic wastewater in an open purification tank. The results showed that immobilization had no significant effect on cell viability and was beneficial for the reproduction and adhesion of cells. The entrapped KSND exhibited a slightly higher nitrogen removal efficiency of 90.09% than that of free KSND (87.69%). Subsequently, repeated batch cultivation experiments and analysis of the effects of organic contaminants and metal ions were performed using artificial wastewater and domestic wastewater. The findings revealed that the immobilized KSND beads presented desirable biophysical properties with good mechanical stability, cell viability, and enrichment, remarkable stability in organic contaminants and metal ions, and high efficiency nitrogen removal capacity. In conclusion, the developed immobilized denitrifying bacteria system has great potential for continuous wastewater treatment in open bioreactors.

Encapsulating metallic nanoparticles (NPs) with a graphitic carbon shell is a promising strategy to achieve highly efficient and stable electrocatalysts for the hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and electrochemical overall water splitting (OWS). This work presents a simple and facile synthesis of graphitic carbon coated NixRuy alloys. The optimized catalyst (e-Ni0.6Ru0.4@C) displays an ultrafine morphology and outstanding HER and OER activities in alkaline media, which are among the best reported so far for various carbon-based electrocatalysts. Remarkably, the e-Ni0.6Ru0.4@C‖e-Ni0.6Ru0.4@C pair needs a low cell voltage of 1.51/1.62 V for driving OWS to reach 10/100 mA cm−2, far outperforming the benchmark electrode pair Pt/C‖RuO2. As expected, this carbon-based catalyst also exhibits superior durability as compared to that of precious catalysts. The experimental evidence combined with density functional theory (DFT) computations thus demonstrates for the first time that minor Ru alloying enables not only the morphological modulation but also the fine electronic modification of the catalyst, which both facilitate the overall electrochemical reactions on the carbon shell surface. Thus, our results may further shed light on how to design and optimize carbon-based electrocatalysts to achieve enhanced catalytic performance for OWS.

Encapsulating one to three metal atoms or a metallic cluster inside fullerene cages affords endohedral metallofullerenes (EMFs) classified as mono-, di-, tri-, and cluster-EMFs, respectively. Although the coexistence of various EMF species in soot is common for rare-earth metals, we herein report that europium tends to prefer the formation of mono-EMFs. Mass spectroscopy reveals that mono-EMFs (Eu@C2n ) prevail in the Eu-containing soot. Theoretical calculations demonstrate that the encapsulation energy of the endohedral metal accounts for the selective formation of mono-EMFs and rationalize similar observations for EMFs containing other metals like Ca, Sr, Ba, or Yb. Consistently, all isolated Eu-EMFs are mono-EMFs, including Eu@D3h (1)-C74 , Eu@C2v (19138)-C76 , Eu@C2v (3)-C78 , Eu@C2v (3)-C80 , and Eu@D3d (19)-C84 , which are identified by crystallography. Remarkably, Eu@C2v (19138)-C76 represents the first Eu-containing EMF with a cage that violates the isolated-pentagon-rule, and Eu@C2v (3)-C78 is the first C78 -based EMF stabilized by merely one metal atom.

Accurate and in-time monitoring of corrosion inhibitor (CI) residual concentration is a key factor in asset integrity management for oil and gas operations. However, the natural variability of CI residual due to field conditions is usually convoluted with the error introduced by sampling and analytical techniques. In traditional analytical techniques, it is typical to encounter error of over 100%. Recently, a novel nanoscale technique (TrueDetect™, TD) was developed to accurately measure CI in the field. This technique is based on a proprietary spectrometry technique and allows quick and accurate analysis of CI residual at the ppm level. The portable instrument allows field samples to be analyzed on-site without the need for shipping them to a centralized laboratory. In the current study, the TD technique was applied to analyze field samples from various fields. Moreover, the TD technique was capable of analyzing CIs at low dosages and could be used as a method to qualify CI products in the lab and in the field.

The effects of calcium chloride (CaCl2) treatment on chilling injury (CI), reactive oxygen species (ROS) metabolism, and ascorbate-glutathione (AsA-GSH) cycle in loquat fruit at 1 °C storage for 35 d were investigated. The results indicated that CaCl2 treatment remarkably suppressed the increase in browning index and firmness as well as the decrease in extractable juice rate. CaCl2 treatment also decreased the production of superoxide radical (O2•−), hydrogen peroxide (H2O2) content, but increased the 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical (OH•) scavenging ability, the activities of superoxide dismutase (SOD), catalase (CAT), and their gene expressions. Moreover, compared to the control loquat fruit, CaCl2-treated fruit maintained higher contents of AsA, GSH, higher levels of activities of ascorbate peroxidase (APX), glutathione reductase (GR), dehydroascorbate reductase (DHAR), and monodehydroascorbate reductase (MDHAR) and expressions of EjAPX, EjGR, EjMDHAR, and EjDHAR, but exhibited lower glutathione disulfide (GSSG) content. These results suggested that CaCl2 treatment alleviated CI in loquat fruit through enhancing antioxidant enzymes activities and AsA-GSH cycle system to quench ROS.

Thermophilic cyanobacteria are a low-carbon environmental resource with high potential thanks to their innate temperature tolerance and thermostable pigment, phycocyanin, which enhances light utilisation efficiency and generates a high-value product. However, large-scale cultivation and harvesting have always been bottlenecks in unicellular cyanobacteria cultivation due to their micrometric size. In this study, a 40-litre inner-light photobioreactor (PBR) was designed for scaled-up cultivation of Thermosynechococcus elongatus E542. By analysing light transmission and attenuation in the PBR and describing it via mathematical models, the supply of light energy to the reactor was optimised. It was found that the hyperbolic model describes the light attenuation characteristics of the cyanobacterial culture more accurately than the Lambert–Beer model. The internal illumination mode was applied for strain cultivation and showed a two-fold better growth rate and four-fold higher biomass concentration than the same strain grown in an externally illuminated photobioreactor. Finally, the downstream harvesting process was explored. A mixture of chitosan solutions was used as a flocculant to facilitate biomass collection. The effect of the following parameters on biomass harvesting was analysed: solution concentration, flocculation time and flocculant concentration. The analysis revealed that a 4 mg L−1 chitosan solution is optimal for harvesting the strain. The proposed solutions can improve large-scale cyanobacterial biomass cultivation and processing.

The stacking of steel slag has detrimental effects mainly for the waste of resources and the pollution of environment. In this study, a novel method based on microbially induced calcium precipitation (MICP) was proposed by utilizing a type of microorganism named Bacillus mucilaginosus, which could secrete carbonic anhydrase (CA) through the metabolism process, accelerating the hydration of carbon dioxide (CO2) and thus facilitating the formation of carbonate ions (CO32−). First, comparing the biologically deposited calcium carbonate with the chemically deposited one, it was found that the crystallinity and crystal size of the biological deposition was lower, leading to its cementitious properties. Under the condition of 1 wt. (weight) % dosage, the carbonation degree increased from 66.34 to 86.25% and the compressive strength improved greatly from 7.4 to 11.2 MPa as well. The weight gain rate of biologically carbonated specimens was also twice as much as the directly carbonated ones. This work strongly demonstrated that biological carbonation technology could not only improve the CO2 sequestration potential of steel slag but also enhance the mechanical properties and durability of steel slag products. • Bacillus mucilaginosus could resuscitate and proliferate in the steel slag environment. • B. mucilaginosus secreted carbon anhydrase, which could accelerate the hydration of CO 2 and facilitate the precipitation of calcium carbonate. • Biologically carbonated steel slag had greater mechanical performance than directly carbonated one.

Asset integrity for oil and gas operations requires reliable chemical information to troubleshoot factors affecting chemical deliverability and performance. Accurate and precise measurement of corrosion inhibitor (CI) concentration in oilfield brine is significant to asset management. However, historically CI residual measurements are extremely problematic due to the surface-active nature of the chemicals which interact with a host of factors that parasitically deplete the CI solution concentration. It is typical to see >100% error on traditional residual measurements especially where dye transfer techniques are concerned. Current methods and sample handling for measuring residuals involves sending samples to a local laboratory for analysis. This time delay can add to the measurement error due to loss of inhibitor species to the sample container or solids that may form in transport. This paper describes the use of a simple, portable, handheld, onsite, nanotechnology-based, residual method to measure CI concentrations in oilfield brines. With more frequent and highly accurate CI residual feedback operators can react to system conditions that threaten to impact asset integrity. Using the CI residual data provided by a rapid, accurate analytical method, operators could extend asset life and prevent failures long before they become critical.

The g-C3N4QDs were synthesized by a simple solvothermal “tailoring” process from bulk g-C3N4 which have a “strong quenching” behaviour in the presence of TC. The proposed fluorescent sensor has been successfully applied to detect TC in actual samples.

There is an upsurge of interest in improving the stability and prolong the scent holding time of fragrances in cosmetic industry. In this study, to encapsulate the orange essential oils (OEO), nanoethosomes were constructed with optimized proportions of ethanol, water, soybean phosphatidylcholine (SPC), Tween 80, and palm oil sucrose esters (PSE). The controlled-release behavior of nanoethosomes was then studied concerning physicochemical stability, microstructure, and olfactory sensation. The sustained-release effectiveness of the nanoethosomal fragrances was influenced by particle size and OEO amount of specific formula. Herein, there was a positive correlation between particle size and sustained-release effectiveness. In particular, the mean diameter of nanoethosomal orange fragrances (nano-OFs)–prepared by EO-ethanol-water-SPC-Tween 80-PSE (3–7:25:72–68:2:1.0:0.1) and 3%, 5%, and 7% OEO–was 68.6±3.6, 79.5±4.5 and 87.3±6.9 nm, respectively. The results of olfactory sensation and GC-MS analysis showed that these fragrances could sustainedly release the aromatic compounds to yield satisfactory smell longer than that of the conventional orange fragrance. Furthermore, the nano-OF made of 5% EO yield a satisfactory smell more than 3 h, which was 3 times of that of the conventional orange fragrance. This fragrance was stable when stored at 4 °C (>1 year) and 25 °C (>10 months). The knowledge gained from this study will be helpful to develop nanoethosomal fragrances or perfumes for commercial use.

The imine condensation reaction of 5,5'-(benzo[c][1,2,5]thiadiazole-4,7-diyl)diisophthalaldehyde with cyclohexanediamine resulted in a shape-persistent multifunctional tubular organic cage (MTC1). It exhibits selective fluorescence sensing towards divalent Pd ions with a very low detection limit (38 ppb), suggesting effective complexation between these two species. Subsequent reduction of MTC1 and Pd(OAc)2 with NaBH4 afforded a cage-supported catalyst with well-dispersed ultrafine Pd nanoparticles (NPs) in a narrow size distribution (1.9±0.4 nm), denoted as Pd@MTC1-1/5. Such ultrafine Pd NPs in Pd@MTC1-1/5, in cooperation with photocatalytically active MTC1, enable efficient sequential reactions involving visible light-induced aerobic hydroxylation of 4-nitrophenylboronic acid to 4-nitrophenol and the following hydride reduction with NaBH4 . This is the first example of a multifunctional organic cage capable of sensing, directing nanoparticle growth, and catalyzing sequential reactions.

Rare earth barium copper oxide (REBCO) type materials are widely used in second-generation high-temperature superconductor tapes to carry high current volumes. These tapes can provide high critical currents along with good tolerance to perpendicular magnetic fields. However, REBCO tapes generally use a laminate structure that suffers from low peeling strength among its inner interfaces. Previously, we proposed a bending-peeling (BP) method and applied it to measurement of the interfacial strength of REBCO tapes at room temperature. All samples failed at the REBCO layer at room temperature. In this paper, we used the BP method to perform low-temperature interfacial strength measurements at liquid-nitrogen temperatures. There are two types of failure, where one involves peeling of the REBCO layer and the other involves peeling at the interface between the tape and the epoxy resin. The errors in the BP method were discussed in detail. The superconducting current was monitored during the BP experiment and showed that the effect of out-of-plane tensile stress on the superconducting current was not significant before the breaking of the tape. The degradation in the superconductivity is mainly caused by the structural failure of the REBCO layer.

The effect of glycine betaine (GB) treatment on chilling injury (CI), cell membrane integrity and membrane fatty acid metabolism in peach fruit during storage were investigated using biochemical and transcriptomic analysis in this study. The results showed that GB treatment alleviated the CI by suppressing lipoxygenase (LOX), phospholipase D (PLD) and lipase gene expression and enzyme activities, resulting in higher levels of unsaturated fatty acids and degree of unsaturation. In addition, this study suggested that GB treatment could inhibit the release of cytochrome C and caspase-3 activity, thus suppressing cell breakdown and contributing to membrane function. Moreover, transcriptome analysis revealed that genes related to fatty acid biosynthesis and desaturation were enhanced, while genes related to fatty acid degradation and activation of caspases were suppressed by GB treatment. Therefore, GB treatment could maintain normal cell membrane structure and function through upregulating membrane fatty acid biosynthesis and desaturation metabolism and downregulating caspase activation to alleviate CI in peaches.

Stimulated by the recent successful synthesis and crystallographic characterization of the first diuranium carbide endohedral metallofullerene (EMF) U2C@Ih(7)-C80 (Zhang et al. Nat. Commun.; 2018),...

The pace of genetic discovery in complex disease has accelerated exponentially over the last decade. Our fund of knowledge of the foundational genetics in disease has never been as great. There is a clear path forward to the resolution of the genetic architecture toward a point at which we will saturate the biological understanding of disease through genetics. This understanding continues to provide fundamental insights into disease biology and, with the advent of new data and methodologies, the path from gene to function is becoming clearer and cleaner. In this opinion piece, we discuss progress in the genetics of Parkinson disease. We explore what genetics has revealed thus far in the context of disease biology. We highlight mitophagy/autophagy, dopamine metabolism and the adaptive immune system. We try and link these findings together to give a holistic view of pathogenesis with the underlying theme that disease pathogenesis relates to a failure of damage response pathways. In the 1990s, Parkinson’s disease wa disorders and diseases. This review highlights recent advances in our understanding of the methylome's functionality and covers potential new roles for DNA methylation, their readers, writers, and erasers. Additionally, we examine novel insights into the relationship between the methylome, DNA–protein interactions, and their contribution to neurodegenerative diseases. Lastly, we outline the gaps in our knowledge that will likely be filled through the widespread use of newer technologies that provide greater resolution into how individual cell types are affected by disease and the contribution of each individual modification site to disease pathogenicity.

Open-cage fullerenes having an 11-membered orifice and keto lactone groups on the rim of the orifice reacted with both Pd(PPh3)4 and Pd(OAc)2/PPh3 to form a mononuclear palladium(0) complex. Two analogous open-cage fullerenes with 18-membered orifices and carbonyl groups on the rim of the orifice reacted under the same conditions to form dinuclear palladium(0) complexes. Three of the products were characterized by single-crystal X-ray diffraction analysis. In all three structures the palladium is coordinated to a fullerene double bond adjacent to a carbonyl group in an η2 pattern. DFT calculations were carried out to explain the high regioselectivity of the coordination reactions.

Background: Burdock (Arctium lappa L.) is a fructan-rich plant with prebiotic potential. The aim of this study was to develop an efficient enzymatic route to prepare fructooligosaccharides (FOS)-rich and highly antioxidative syrup using burdock root as a raw material. Results: Endo-inulinase significantly improved the yield of FOS 2.4-fold while tannase pretreatment further increased the yield of FOS 2.8-fold. Other enzymes, including endo-polygalacturonase, endo-glucanase and endo-xylanase, were able to increase the yield of total soluble sugar by 11.1% (w/w). By this process, a new enzymatic process for burdock syrup was developed and the yield of burdock syrup increased by 25% (w/w), whereas with FOS, total soluble sugars, total soluble protein and total soluble polyphenols were enhanced to 28.8%, 53.3%, 8.9% and 3.3% (w/w), respectively. Additionally, the scavenging abilities of DPPH and hydroxyl radicals, and total antioxidant capacity of the syrup were increased by 23.7%, 51.8% and 35.4%, respectively. Conclusions: Our results could be applied to the development of efficient extraction of valuable products from agricultural materials using enzyme-mediated methods.How to cite: Tian K, Wang J, Zhang Z, et al. Expression and purification of a transcription factor StMsn2 from Setosphaeria turcica in Escherichia coli. Electron J Biotechnol 2019;40. https://doi.org/10.1016/j.ejbt.2019.04.009 Keywords: Antioxidant activity, Arctium, Burdock, Endo-inulinase, Enzymatic process, Fructooligosaccharides, Functional food, Fungitetraose, Hydroxyl radical, Polygalacturonase, Polyphenols, Tannase

Ferrous ion (Fe2+) in a sulfate reducing bacteria (SRB) culture medium is known to enhance microbiologically influenced corrosion (MIC) of carbon steel, but the underlining mechanism is controversial. This work showed that it was due to better sessile cell growth that was likely attributed to Fe2+ detoxification of H2S. Two hundred ppm (w/w) initial Fe2+ in the ATCC 1249 medium achieved a 4.7 times higher Desulfovibrio vulgaris sessile cell count and 5.0 times higher C1018 carbon steel weight loss, compared to 20 ppm. Linear polarization resistance, electrochemical impedance spectroscopy and potentiodynamic polarization measurements corroborated weight loss and pitting data trends.

Here, the draft genome of simultaneous nitrification-denitrification strain (SND) Klebsiella sp. KSND revealed possible existence of genes involved in N-assimilation and -dissimilation pathways. The change levels of genes under defined N-sources were analyzed by Quantitative Real-Time PCR. It suggested that NH4+-assimilation via NADP-glutamate dehydrogenase pathway would occur preferentially. NirBD genes were tightly regulated in a lower level, so that nitrite was rapidly consumed for detoxication by denitrification. Three types of nitrate reductase homologues are surprisingly present in KSND, whereas the dominant nitrate reduction for assimilation and denitrification processes mediates by NapA-type nitrate reductase. Nitric oxide reductase homologues FlRd and FlRd-red provide an adequate capacity for NO detoxification. The recombinant hydroxylamine reductase showed high activity in hydroxylamine to generate ammonium, which might contribute to detoxification mechanism in nitrogen cycling. Overall, this study firstly provides valuable insights into the genes expression and enzyme action, which helps understanding the mechanism of SND processes.

Endohedral metallofullerenes (EMFs) are fullerene cages enclosing various metallic species. The functionalization of EMFs has remarkably blossomed in recent years, in contrast to early efforts that were mainly devoted to their geometric and electronic structures as well as optical and magnetic properties. This review presents an exhaustive survey of the important functionalization approaches of EMFs, mainly focusing on the progress since 2014. The involved reactions include silylation and germylation, Diels–Alder reaction, Bingel–Hirsch reaction, 1,3-dipolar cycloaddition, carbene addition, benzyne addition, free radical reaction, hydroxylation, dimerization, coordination reaction, noncovalent complexation, as well as numerous miscellaneous reactions. We summarize the main factors that affect the reactivity and regioselectivity, focusing particularly on the intriguing interplay between the exohedral groups and internal species. This work highlights the established role of current theoretical studies in further understanding the reactivity and regioselectivity of functionalization reactions. Finally, we discuss potential applications of exohedrally modified EMFs.

Diatoms are experiencing striking fluctuations in seawater carbonate chemistry in the natural marine environment, especially in coastal seawaters. Here, we show that the diatoms Thalassiosira weissflogii and Phaeodactylum tricornutum, which utilize different carbon acquisition mechanisms, respond differently to short-term changes in seawater carbonate chemistry. Our results showed that T. weissflogii showed significantly higher photosynthetic oxygen evolution rates than that of P. tricornutum at low levels of CO2 or HCO3−. This suggests that T. weissflogii had higher affinities for CO2 or HCO3− when their concentrations were not sufficient to support saturated growth and photosynthesis. While the activity of Rubisco in P. tricornutum positively correlated with carbonic anhydrases (CA), we observed negative relationship between Rubisco and CA activity in the diatom T. weissflogii. These contrasting physiological responses of diatoms with varied carbon acquisition mechanisms indicate different abilities to cope up with abrupt changes in seawater carbonate chemistry. We propose that the ability to respond to varying carbonate chemistry may act as one determinant of the diatom distributions and phytoplankton community structures.

Cold plasma technology offers new opportunities to the decontamination and preservation of fruits and vegetables. In the present research, strawberries were cut into four wedges and then treated with dielectric barrier discharge plasma at 45 kV for 1 min and stored for 1 week (4 °C). Metabolomic analysis suggested that plasma treatment improved the biosynthesis of the metabolites in the "flavones and flavonol biosynthesis" pathway and "biosynthesis of phenylpropanoids" pathway in fresh-cut strawberries. Physiological assay demonstrated that plasma treatment maintained the texture properties and inhibited microbial growth of fresh-cut strawberries. In addition, plasma treatment also promoted the accumulation of total phenolics, total flavonoid, and anthocyanin by enhancing the critical enzyme activities and activating related gene expression in phenylpropanoid as well as reactive oxygen species metabolism, which contributed greatly to the enhancement of antioxidant capacity of strawberry wedges. Our investigation provided a new perspective of the effect of plasma treatment on the safety and quality of strawberry wedges and suggested that cold plasma treatment holds promise as an emerging processing technology for improving the quality and antioxidant activity of postharvest fruits and vegetables.

Interactions between the inner and outer units through a fullerene cage are of fundamental importance for the creation of molecular spintronics and machines, but the mechanism of such through-cage interplay is still unclear. In this work, we have designed and synthesized two prototypical compounds which contain only a single europium atom inside the cage and merely a tungsten atom coordinating outside to clarify the interactions between the endohedral and exohedral metallic units. They are obtained by reacting a tungsten complex W(CO)4(Ph2PC2H4PPh2) (1) with the corresponding metallofullerenes in a highly regioselective manner (2a for Eu@C2(5)-C82 and 2b for Eu@C2(13)-C84). On the one hand, the endohedral Eu-doping has changed the LUMO distribution on C2(5)-C82/C2(13)-C84 dramatically, via electron transfer, which governs the addition pattern of the exohedral tungsten resulting in surprisingly high regioselectivity. On the other hand, the exohedral tungsten coordination with Eu@C2(5)-C82/Eu@C2(13)-C84 has restricted the motion of the internal europium ion to some extent by changing the electrostatic potentials, as confirmed by the X-ray results of 2a, 2b and the corresponding pristine metallofullerenes cocrystallized with Ni(OEP) (OEP is the dianion of octaethylporphyrin). We now make it clear that the interplay between the endohedral and exohedral metallic units can be realized in a single system by means of intramolecular charge transfer, which may arouse interest in the design and utilization of novel metallofullerene-based molecular devices.

Direct yttrium–yttrium bonding has been a long-sought puzzle in organometallic chemistry to understand the catalytic processes that involve yttrium. Herein, we report the first crystallographic authentication of direct Y–Y bonding inside the hollow cavity of fullerene cages by forming endohedral metallofullerenes (EMFs). Based on an efficient separation/purification process, which involves Lewis-acid treatment and HPLC separation, we have obtained sufficient amounts of a series of Y2C2n (2n = 82, 88–94) isomers for systematic studies. The unambiguous single-crystal X-ray diffraction (XRD) crystallographic results show that two of them are di-EMFs, namely Y2@Cs(6)-C82 and Y2@C3v(8)-C82, in which the long-sought Y–Y single bond between the two divalent yttrium ions is experimentally confirmed for the first time. In contrast, all the other EMFs with relatively large cages are carbide cluster metallofullerenes (CCMFs), namely, Y2C2@Cs(15)-C86, Y2C2@C1(26)-C88, Y2C2@C2(41)-C90 and Y2C2@C2(61)-C92. Consistently, our computational results prove that these experimentally obtained EMFs are all abundant at the high temperatures for fullerene formation (∼1500–3000 K) due to the strong coordination ability of yttrium ions, which enables the formation of either direct Y–Y bonds (for Y2@Cs(6)-C82 and Y2@C3v(8)-C82) or the inclusion of a C2-unit (in Y2C2@Cs(15)-C86, Y2C2@C1(26)-C88, Y2C2@C2(41)-C90 and Y2C2@C2(61)-C92). Our results suggest that metal atoms such as yttrium tend to adopt a low valence state during the arc-discharge process because of the presence of the highly reductive carbon plasma in the chamber, enabling the formation of an Y2 dimer with direct Y–Y bonding in small cages like C82.

Metal–organic framework (MOF) nanosheets are a new type of two-dimensional nanomaterial. Their properties and performances are expected to correlate strongly with the sheet structure, particularly the number of layers (sheet thickness). Yet, synthetically controlling the layer number at the molecular scale is highly difficult. Herein, a facile method is introduced to fabricate substrate-supported MOF nanosheets with precisely controllable layer numbers, using the Langmuir–Blodgett technique. Large-area, porous, and uniform MOF nanosheets, based on 5,10,15,20-tetrakis[4′-(terpyridinyl)phenyl]porphyrin-cobalt(II) (Co-TTPP) coordination polymer, were constructed and characterized in detail by atomic force microscopy, transmission electron microscopy, energy dispersive spectroscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy, and a photoelectronic conversion technique. As a prototype sensor device, a series of substrate-supported Co-TTPP nanosheets was further investigated for the fluorescence detection of DNA towards rapid clinical diagnosis. The ten-layer Co-TTPP nanosheet exhibits an impressive performance with a very low detection limit of ca. 0.1 nM, outstanding specificity, and multiplexed DNA detection, comparable to some top-notch free-standing nanomaterial sensors. Importantly, our results also revealed the synergistic contributions of suitable pore size and optimal layer number of the Co-TTPP nanosheet for highly efficient DNA detection for the first time.

The Lewis acid–base pairing reaction between strained N-heterocyclic carbene (NHC) and endohedral metallofullerenes (EMFs) is an efficient strategy to obtain stable derivatives in a highly regioselective manner. Herein, we report an in-depth study on the reactions between 3-dimesityl-1H-imidazol-3-ium-2-ide (1) and three different EMFs, namely, Lu3N@Ih(7)-C80, Lu2@C3v(8)-C82, and Lu2@C2v(9)-C82, respectively. Only one monoadduct is obtained for each EMF under certain conditions, demonstrating surprisingly high regioselectivity and exclusive formation of monoadducts. X-ray results of the derivatives of Lu3N@C80 reveal that an epoxide adduct (2a) with a specific [6,6,6]-carbon atom of the C80 cage singly bonded to the normal carbene center (C2) of the NHC is obtained under ambient condition, whereas a pure argon atmosphere gives 2b with an abnormal C5-bonding structure. In contrast, the derivatives of Lu2@C82 (3 and 4) are both normal C2-bonding [5,6,6]-adducts without oxygen addition, even though air is in...

SUMMARY 5-hydroxymethylcytosine (5hmC) is enriched in brain and has been recognized as an important DNA modification. However, the roles of 5hmC and its writers, ten-eleven translocation (Tet) proteins, in stress-induced response have yet to be elucidated. Here, we show that chronic restraint stress (CRS) induced depression-like behavior in mice and resulted in a 5hmC reduction in prefrontal cortex (PFC). We found that loss of Tet1 (Tet1 KO) led to resistance to CRS, whereas loss of Tet2 (Tet2 KO) increased the susceptibility of mice to CRS. Genome-wide 5hmC profiling identified the phenotype-associated stress-induced dynamically hydroxymethylated loci (PA-SI-DhMLs), which are strongly enriched with hypoxia-induced factor (HIF) binding motifs. We demonstrated the physical interaction between TET1 and HIF1α induced by CRS and revealed that the increased HIF1α binding under CRS is associated with SI-DhMLs. These results suggest that TET1 could regulate stress-induced response by interacting with HIFIα., Graphical Abstract, In Brief The roles of 5-hydroxymethylcytosine (5hmC) and its writers, Tet proteins, in stress-induced response remain unclear. Cheng et al. show that Tet1 knockout mice exhibit resistance, whereas Tet2 knockout mice have increased susceptibility to stress. Biochemical and genome-wide analyses suggest that Tet1 could regulate stress-induced response by interacting with Hif1α.

N6-methyladenosine (m6A) modification is the most prevalent internal mRNA modification and is involved in many biological processes in eukaryotes. Accumulating evidence has demonstrated that m6A may play either a promoting or suppressing role in breast cancer, including in tumorigenesis, metastasis and angiogenesis. In this review, we summarize the latest research progress on the biological function and prognostic value of m6A modification in breast cancer, as well as potential related therapeutic strategies.

N6-methyladenosine (m6A) methylation is the most prevalent internal modification of post-transcriptional modifications in mRNA, tRNA, miRNA, and long non-coding RNA in eukaryotes. m6A methylation has been proven to be involved in plant resistance to pathogens. However, there are no reports on wheat (Triticum aestivum) m6A transcriptome-wide map and its potential biological function in wheat resistance to wheat yellow mosaic virus (WYMV). To the best of our knowledge, this study is the first to determine the transcriptome-wide m6A profile of two wheat varieties with different resistances to WYMV. By analyzing m6A-sequencing (m6A-seq) data, we identified 25,752 common m6A peaks and 30,582 common m6A genes in two groups [WYMV-infected resistant wheat variety (WRV) and WYMV-infected sensitive wheat variety (WSV)], and all these peaks were mainly enriched in 3′ untranslated regions and stop codons of coding sequences. Gene Ontology analysis of m6A-seq and RNA-sequencing data revealed that genes that showed significant changes in both m6A and mRNA levels were associated with plant defense responses. Kyoto Encyclopedia of Genes and Genomes analysis revealed that these selected genes were enriched in the plant–pathogen interaction pathway. We further verified these changes in m6A and mRNA levels through gene-specific m6A real-time quantitative PCR (RT-qPCR) and normal RT-qPCR. This study highlights the role of m6A methylation in wheat resistance to WYMV, providing a solid basis for the potential functional role of m6A RNA methylation in wheat resistance to infection by RNA viruses.

BackgroundMedulloblastoma (MB) is the most common malignant pediatric brain tumor that originates in the cerebellum and brainstem. Frequent somatic mutations and deregulated expression of epigenetic regulators in MB highlight the substantial role of epigenetic alterations. 5-hydroxymethylcytosine (5hmC) is a highly abundant cytosine modification in the developing cerebellum and is regulated by ten-eleven translocation (TET) enzymes.ResultsWe investigate the alterations of 5hmC and TET enzymes in MB and their significance to cerebellar cancer formation. We show total abundance of 5hmC is reduced in MB, but identify significant enrichment of MB-specific 5hmC marks at regulatory regions of genes implicated in stem-like properties and Nanog-binding motifs. While TET1 and TET2 levels are high in MBs, only knockout ofTet1in the smoothened (SmoA1)mouse model attenuates uncontrolled proliferation, leading to a favorable prognosis. The pharmacologicalTet1inhibition reduces cell viability andplatelet-derived growth factorsignaling pathway-associated genes.ConclusionsThese results together suggest a potential key role of 5hmC and indicate an oncogenic nature for TET1 in MB tumorigenesis, suggesting it as a potential therapeutic target for MBs.

The use of a small molecule compound to reduce toxic repeat RNA transcripts or their translated aberrant proteins to target repeat-expanded RNA/DNA with a G4C2 motif is a promising strategy to treat C9orf72-linked disorders. In this study, the crystal structures of DNA and RNA–DNA hybrid duplexes with the -GGGCCG- region as a G4C2 repeat motif were solved. Unusual groove widening and sharper bending of the G4C2 DNA duplex A-DNA conformation with B-form characteristics inside was observed. The G4C2 RNA–DNA hybrid duplex adopts a more typical rigid A form structure. Detailed structural analysis revealed that the G4C2 repeat motif of the DNA duplex exhibits a hydration shell and greater flexibility and serves as a ‘hot-spot’ for binding of the anthracene-based nickel complex, NiII(Chro)2 (Chro = Chromomycin A3). In addition to the original GGCC recognition site, NiII(Chro)2 has extended specificity and binds the flanked G:C base pairs of the GGCC core, resulting in minor groove contraction and straightening of the DNA backbone. We have also shown that Chro-metal complexes inhibit neuronal toxicity and suppresses locomotor deficits in a Drosophila model of C9orf72-associated ALS. The approach represents a new direction for drug discovery against ALS and FTD diseases by targeting G4C2 repeat motif DNA.

A Correction to this paper has been published: https://doi.org/10.1038/s41467-021-21726-y

Epigenetic modifications of DNA play important roles in many biological processes. Identifying readers of these epigenetic marks is a critical step towards understanding the underlying mechanisms. Here, we present an all-to-all approach, dubbed digital affinity profiling via proximity ligation (DAPPL), to simultaneously profile human TF-DNA interactions using mixtures of random DNA libraries carrying different epigenetic modifications (i.e., 5-methylcytosine, 5-hydroxymethylcytosine, 5-formylcytosine, and 5-carboxylcytosine) on CpG dinucleotides. Many proteins that recognize consensus sequences carrying these modifications in symmetric and/or hemi-modified forms are identified. We further demonstrate that the modifications in different sequence contexts could either enhance or suppress TF binding activity. Moreover, many modifications can affect TF binding specificity. Furthermore, symmetric modifications show a stronger effect in either enhancing or suppressing TF-DNA interactions than hemi-modifications. Finally, in vivo evidence suggests that USF1 and USF2 might regulate transcription via hydroxymethylcytosine-binding activity in weak enhancers in human embryonic stem cells., Identifying readers of epigenetic marks is a critical step for understanding the role of epigenetic marks in biology. Here, the authors applied DAPPL, an all-to-all approach to profile the interactions between TFs and epigenetic modified DNA libraries.

Background Chinese wheat mosaic virus (CWMV) is a severe threat to winter wheat and is transmitted by Polymyxa graminis. The mechanisms of interactions between CWMV and plants are poorly understood. In this study, a comparative proteomics analysis based on nanoliquid chromatography mass spectrometry (MS)/MS was conducted to characterize proteomic changes in plants responding to CWMV infection. Results In total, 2751 host proteins were identified, 1496 of which were quantified and 146 up-regulated and 244 down-regulated proteins were identified as differentially expressed proteins (DEPs). Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that DEPs were most strongly associated with photosynthesis antenna proteins, MAPK signaling plant and glyoxylate and dicarboxylate metabolism pathways. Subcellular localization analysis predicted that more than half of the DEPs were localized in the chloroplast, an organelle indispensable for abscisic acid (ABA) synthesis. Our results suggest that CWMV infection interrupts normal chloroplast functions and decreases ABA concentrations in Nicotiana benthamiana. Further analysis showed that the ABA pathway was suppressed during CWMV infection and that ABA treatment induced plant hosts defenses against CWMV. Conclusions We identified several candidate proteins expressed during CWMV infection, and the ABA pathway was strongly associated with responses to CWMV infection in N. benthamiana.

WRKY transcription factors play important roles in plants, including responses to stress; however, our understanding of the function of WRKY genes in plant responses to viral infection remains limited. In this study, we investigate the role of NbWRKY40 in Nicotiana benthamiana resistance to tomato mosaic virus (ToMV). NbWRKY40 is significantly downregulated by ToMV infection, and subcellular localization analysis indicates that NbWRKY40 is targeted to the nucleus. In addition, NbWRKY40 activates W-box-dependent transcription in plants and shows transcriptional activation in yeast cells. Overexpressing NbWRKY40 (OEWRKY40) inhibits ToMV infection, whereas NbWRKY40 silencing confers susceptibility. The level of salicylic acid (SA) is significantly higher in OEWRKY40 plants compared with that of wild-type plants. In addition, transcript levels of the SA-biosynthesis gene (ICS1) and SA-signaling genes (PR1b and PR2) are dramatically higher in OEWRKY40 plants than in the control but lower in NbWRKY40-silenced plants than in the control. Furthermore, electrophoretic mobility shift assays show that NbWRKY40 can bind the W-box element of ICS1. Callose staining reveals that the plasmodesmata is decreased in OEWRKY40 plants but increased in NbWRKY40-silenced plants. Exogenous application of SA also reduces viral accumulation in NbWRKY40-silenced plants infected with ToMV. RT-qPCR indicates that NbWRKY40 does not affect the replication of ToMV in protoplasts. Collectively, our findings suggest that NbWRKY40 likely regulates anti-ToMV resistance by regulating the expression of SA, resulting in the deposition of callose at the neck of plasmodesmata, which inhibits viral movement.