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Background Ochratoxin A (OTA) is a harmful mycotoxin and secondary metabolite produced by several species of Aspergillus and Penicillium. It is of vital importance to establish a sensitive method to detect OTA in various grains. Objective A novel, highly sensitive chemiluminescence immunoassay was developed to determine OTA in wheat, corn, and poultry feed. Methods The immunomagnetic beads were used as solid phase carriers and separators in the competitive chemiluminescence method. Anti-OTA monoclonal antibodies coated on the magnetic beads were applied as the capturing antibodies, in which OTA would compete with OTA-alkaline phosphatase in binding with OTA antibodies. Results The proposed method exhibited good linearity (R2 ≥ 0.999), adequate OTA recovery rate (83.60–102.50%), and good repeatability. The sensitivity of the proposed method was 2.05 pg/mL. In addition, the method was highly selective and showed no cross-reactions with other mycotoxins (e.g., AFB1, DON, ZEN). The developed method was applied in the analysis of wheat, corn, and two animal feeds successfully. The results obtained by the chemiluminescence method showed a high correlation with those obtained by the HPLC method (correlation coefficient 0.9958). Conclusion This strategy shows great potential for other toxic and harmful mycotoxin detection. Highlights A novel highly rapid and sensitive chemiluminescence immunoassay was established for quantitation of OTA.

In this study, a sensitive high-performance liquid chromatography method for zearalenone determination in feeds and grains was established based on the automatic immunomagnetic bead purifier analyzer (KY-AMI-I) for the one-step sample pre-treatment. Various parameters that may affect the analytical performance were investigated. Immunomagnetic bead separation system based on a monoclonal antibody (anti-ZEN antibody-immunomagnetic beads conjugation) was individually prepared for the ZEN purification. Besides, the average recoveries in spiked samples ranged from 75.23 to 102.62%, and the relative standard deviations were between 3.55 and 8.07% (

MoP is a promising anode material choice for alkali ion storage ascribed to its superior electrochemical performance. However, severe volume expansion and poor stability limited its output performance. Here, well-dispersed MoP nanoparticles are confined in carbon nanofiber skeleton by facile electrospinning method, further introduction of titania enhances the interfacial reaction and structure stability. As a result, the carbon nanofiber encapsulated MoP/TiO2 composite exhibited 150 mAh g−1 at 1 A g−1 for 4000 cycles, without obvious capacity decay. The homogenous dispersion and heterostructure construction contribute to its superior performance. This design provides a simple way for the phosphide preparation.

Background The ultrasensitive monitoring strategy of zearalenone (ZEN) is essential and desirable for food safety and human health. In the present study, a coupling of gold nanoparticles-DNA barcode and direct competitive immunoassay-based real-time polymerase chain reaction signal amplification (RT-IPCR) for ZEN close to the sensitivity of PCR-like levels is described and evaluated. Results The RT-IPCR benefited from the use of a DNA barcode and RT-PCR detection strategy, thus resulting in ultrasensitive and simple detection for ZEN. Under the optimal RT-IPCR, the linear range of detection was from 0.5 to 1000 pg mL-1 and the limit of detection was 0.5 pg mL-1 , which was 400-fold lower than the enzyme-linked immunosorbent assay. The detection procedure was simplified and the detection time was shortened. The specificity, accuracy and precision of the RT-IPCR confirmed a high performance. ZEN-positive contamination levels were from 0.056 to 152.12 ng g-1 by the RT-IPCR, which was demonstrated to be highly reliable by liquid chromatography-tandem mass spectrometry. Conclusion The proposed RT-IPCR could be used as an alternative for detecting ZEN with satisfactory ultrasensitivity, simplicity, low cost and high-throughput. The present study could provide a strategy for the ultrasensitive detection of the small molecule with a simple and practical approach, which has significant appeal and application prospects.

Organic porous crystals constructed by only a single kind of weak molecular interaction are invaluable to understanding the nature of the formation of organic porous materials and developing new types of porous materials. Here, we designed and synthesized two pure organic compounds of PBO and PBS through integrating planar dibenzothiophene/dibenzofuran and two phenothiazine groups together with twisted C-N bonds, which form organic microporous crystals with very good stability against strong acids and bases via pure C-H•••π interactions. Accordingly, the effective absorption of toluene has been successfully realized with adsorbing capacity of 6.20 mmol g-1, regardless of the interference of water vapour. Excitedly, these microporous materials exhibit interesting crystal-to-crystal transformation (CCT) property accompanying with the changed pore size, once being fumigated by different organic solvents. Therefore, the desorption process of toluene could be completed through simple fumigation with dichloromethane (DCM) and the second transformation of the crystal occurred in this process.

2,5-Furandicarboxylic acid (FDCA) has the potential to replace terephthalic acid (TPA) as a building block in the preparation of bio-based and degradable polyester materials. However, the lack of efficient and stable catalysts limits the commercial viability of FDCA production. In this work, metalloporphyrins were immobilized on mesoporous SiO2 and used as a novel oxidase to convert 5-hydroxymethylfurfural (HMF) to FDCA. As the catalytic active center of P450 monooxygenases and horseradish peroxidase, supported palladium, manganese, ferri, and cobalt porphyrins via ionic-liquid-functionalized SiO2 (PdPOP-SiO2, MgPOP-SiO2, FePOP-SiO2 and CoPOP-SiO2) were able to simulate oxidase alone under mild conditions. 100% HMF (0.02 M) conversion and 94.94% FDCA yield were achieved using PdPOP-SiO2 as a biomimetic oxidase after a 12 h reaction at 373 K in water at atmospheric pressure. This type of mimetic oxidase is stable, inexpensive, and readily available, and the method developed in this work can potentially be used to oxidize HMF to FDCA in an industrial setting.

In this work, a ratiometric fluorescent probe (RF-probe) for highly sensitive and selective detection of uric acid was reported for the first time toward H2O2 based on inner filter effect (IFE) between bimetallic gold/silver nanoclusters (Au/Ag NCs) and 2,3-diaminophenazine (DAP). For this RF-probe, uric acid was degraded to allantoin and H2O2. Upon the addition of HRP, o-phenylenediamine (OPD) could be catalytically oxidized to DAP in the presence of H2O2, then the fluorescence intensity corresponding to DAP at 580 nm increased dramatically with a fluorescence quenching of BSA-Au/Ag NCs at 690 nm, resulting in a RF-probe toward uric acid. This RF-probe allowed for the sensitive detection of uric acid in range of 5.0 × 10−6 M to 5.0 × 10−5 M with a detection limit (S/N = 3) as low as 5.1 × 10−6 M. At the same time, it has been successfully used for uric acid levels detection in human serum, and the results are consistent with those of the hospital. RF-probe built may provide a ratiometric fluorescence universal platform for detection of various species involving in the production of H2O2 in other biological systems.

Zearalenone (ZEN) has a potential hazard to human health, and is frequently found in agro-products. To minimize ZEN exposure to consumers, a novel metal-organic framework-based immunoassay system using zeolitic imidazolate framework-encapsulated horseradish peroxidase and goat anti-mouse IgG (HRP/Ab@ZIF-L) as labels was proposed for rapid and ultrasensitive detection of ZEN in agro-products. The HRP/Ab@ZIF-L not only maintained recognition ability of antibody and catalytic activity of enzyme, but also protected encapsulated proteins against high temperature, organic solvents and long term storage. Under optimal conditions, the detection limit of HRP/Ab@ZIF- L -based immunoassay reached 0.5 ng/L for ZEN, which was approximately 126-fold lower than that of conventional HRP-based immunoassay. Moreover, the proposed method showed an excellent selectivity, and a good dynamic linear detection for ZEN in the range of 0.5 ng/L to 0.476 μg/L. The recoveries of ZEN from spiked corn and wheat samples ranged from 84.50% to 96.70% with the relative standard deviation under 8.9%. In brief, the proposed immunoassay method has potential application for rapid and ultrasensitive detection of ZEN in agro-products.

Zearalenone (ZEN) is a prevalent mycotoxin that needs intensive monitoring. A semi-quantitative and quantitative immunochromatographic assay (ICA) was assembled for investigating ZEN contamination in 187 samples of cereal and their products from China in 2019. The semi-quantitative detection model had a limit of detection (LOD) of 0.50 ng/mL with visual judgment and could be completely inhibited within 5 min at 3.0 ng/mL ZEN. The quantitative detection model had a lower LOD of 0.25 ng/mL, and ZEN could be accurately and digitally detected from 0.25&ndash, 4.0 ng/mL. The ICA method had a high sensitivity, specificity, and accuracy for on-site ZEN detection. For investigation of the authentic samples, the ZEN-positive rate was 62.6%, and the ZEN-positive levels ranged from 2.7 to 867.0 ng/g, with an average ZEN-positive level being 85.0 ng/g. Of the ZEN-positive samples, 6.0% exceeded the values of the limit levels. The ZEN-positive samples were confirmed to be highly correlated using LC-MS/MS (R2 = 0.9794). This study could provide an efficiency and accuracy approach for ZEN in order to achieve visual and digitized on-site investigation. This significant information about the ZEN contamination levels might contribute to monitoring mycotoxin occurrence and for ensuring food safety.

The potential homogeneous assay employing immunomagnetic beads (IMB) has been receiving attention as a screening tool in food-safety control; the method is simple, efficient, and does not require long incubation times or complex separation steps. In this study, a homogeneous immunoassay has been successfully developed and applied in the determination of aflatoxin B1 (AFB1) contamination in agricultural products by coupling IMB and the biotin-streptavidin (BSA) (BSA-IMB) system. Under optimal conditions, the limit of detection (LOD, IC10), half-maximal inhibition concentration (IC50) and detection range (IC20–IC80) of BSA-IMB are 0.00579, 0.573 and 0.0183–17.9 ng mL−1, respectively, for AFB1. The detection of AFB1 by BSA-IMB can be achieved in 40 min (ELISA needs at least 180 min). The cross-reactivities of BSA-IMB with its analogues are negligible (

Tetrabromobisphenol A bis(2-hydroxyethyl) ether (TBBPA DHEE), as one of the TBBPA derivatives, is frequently applied as a flame retardant. To date, however, little evidence has been gathered regarding its environmental behavior and fate. This is mainly attributed to the lack of an analytical approach available to measure it. Mass spectrometry cannot determine levels of TBBPA DHEE. LC-MS could not ionize TBBPA DHEE to yield enough fragments, while GC-MS could not be applied for the analysis either, due to the thermal degradation of TBBPA DHEE. We here designed a novel hapten, then conjugated it with a carrier protein and produced a type of polyclonal antibody capable of recognizing TBBPA DHEE. Based on this approach, a sensitive and high-throughput indirect competitive enzyme-linked immunosorbent assay (ELISA) was established. The respective detection limit (LOD, based on 90% B/B0) and IC50 calculated from the standard curve were 0.702 and 9.868 ng/mL for TBBPA DHEE. And the established method showed good tolerance to various matrix interferents. Using our ELISA, we measured the concentrations of these substances from environmental water samples with no pretreatment other than filtration. We found the presence of TBBPA DHEE in environmental water samples collected in Jiangsu province, and the detected concentrations ranging from 1.5 to 7.7 ng/mL. Our proposed method here could be applied to completely and systematically investigate TBBPA DHEE and TBBPA MHEE concentrations in environmental samples.

On the basis of H2O2-mediated growth of gold nanoparticle (AuNPs), a novel plasmonic enzyme-linked immunosorbent assay (pELISA) was developed with a polyclonal antibody for the ultrasensitive simultaneous naked-eye detection of tetrabromobisphenol A bis(2-hydroxyetyl) ether (TBBPA DHEE) and tetrabromobisphenol A mono(hydroxyethyl) ether (TBBPA MHEE), one of the major derivatives and byproducts of tetrabromobisphenol A (TBBPA), respectively. In this modified indirect competitive pELISA, glucose oxidase (GOx) played an important role leading to the growth of AuNPs through a reaction between GOx and glucose to produce hydrogen peroxide (H2O2). In addition, further signal amplification was achieved via a large number of GOx molecules, which were immobilized on silica nanoparticles carrying poly brushes (SiO2@PAA) to increase the enzyme load, and the whole complex was conjugated on the second antibody. Under the optimized conditions, 10–3 μg/L TBBPA DHEE can be distinguished via the observation of a colored so...

The giant Shangfanggou skarn-porphyry Mo–Fe deposit, one of the largest Mo deposits in the East Qinling Orogen, is hosted by the Neoproterozoic Luanchuan Group on the southern margin of the North China Craton. The mineralization occurs mainly as veinlets and in veinlet-disseminated form within altered schists, skarns, hornfelses, and/or marbles. The hydrothermal alteration and mineralization at Shangfanggou took place over four stages. Stage 1 involved potassic alteration and silicification in the porphyry, skarnization and magnetization in carbonate strata, and hornfelsization in schists. Quartz–molybdenite veins associated with phyllic alteration were produced in the porphyry during stage 2, along with sericitization, chloritization, serpentinization, and silicification in the skarns, hornfelses and/or marbles. Quartz–polymetallic sulfide veins related to phyllic alteration were produced during stage 3, and ore-barren quartz ± calcite ± pyrite veins associated with weak carbonatation were produced during stage 4. C, O, and D isotope compositions of hydrothermal calcite, dolomite, magnetite, phlogopite, and quartz from different stages of mineralization during the formation of the Shangfanggou deposit range from − 12.9‰ to + 8.8‰, − 3.2‰ to + 22.7‰, and − 100‰ to − 80‰, respectively. Sulfur isotope compositions of sulfides from the ores of the Shanfanggou deposit range from 3.6‰ to 4.4‰. 206 Pb/ 204 Pb, 207 Pb/ 204 Pb, and 208 Pb/ 204 Pb ratios of 17.648 to 18.742 (apart from one magnetite with a value of 20.78), 15.526 to 15.690, and 38.197 to 39.823 in the Shanfanggou deposit. The evolution of the ore-forming fluids in the Shangfanggou deposit, as revealed by δ 18 O, δD, and δ 13 C isotope studies, was one of progressive modification of the magmatic fluids through fluid–wall rock interactions along conduits during fluid ascent, and this signifies the involvement of formation/strata water during the earlier stages of mineralization, and the predominance of meteoric waters over magmatic fluids in the later stages. The carbon, sulfur, and lead isotope compositions suggest mixing took place between the magmas and the host rocks within the region. Integrating the data obtained from studies of the regional geology, ore geology, fluid inclusions, and C–H–O–S–Pb isotope geochemistry, we conclude that the Shangfanggou Mo–Fe deposit is a porphyry-skarn type system that formed during a transition from compressional to extensional tectonics during the Jurassic–Early Cretaceous continental collision between the North China Craton and Yangtze Craton. The ore materials were sourced from magmatic ore-forming fluids that mixed with components derived from carbonaceous wall rocks during their ascent, and which were gradually mixed with meteoric waters, especially in the later stages.

Alpha-melanocyte stimulating hormone (αMSH) has an important role in the regulation of body weight and energy expenditure. Nevertheless, the molecular mechanisms of circulating αMSH on preadipocyte proliferation remain elusive. We found αMSH was reduced by high fat diet (HFD) while leptin was elevated in adipose tissue. Leptin resistance and endoplasmic reticulum (ER) stress of adipose tissue were increased in obese mice. αMSH increased leptin sensitivity and alleviated ER stress along with increased p-STAT3 level and reduced SOCS3, GRP78, CHOP, ATF4, p27 and p53 levels. αMSH and leptin co-treatment alleviated ER stress through decreasing the levels of GRP78 and CHOP. Tunicamycin (TM) or thapsigargin (Tg) induced ER stress blunted leptin sensitivity and inhibited preadipocyte proliferation. αMSH and leptin co-treatment increased the cell number, augmented G1-S transition, elevated leptin sensitivity, and reduced ER stress; it also activated Notch1 signal and stimulated preadipocyte proliferation, whereas ER stress marker genes were decreased during this process. However, the effects of αMSH and leptin were blocked by the specific inhibitor of Notch1 signal. In summary, our data revealed αMSH enhanced leptin sensitivity and preadipocyte proliferation, meanwhile inhibited ER stress of preadipocytes by activating Notch1 signal.

A fast and ultrasensitive indirect competitive time-resolved fluoroimmunoassay (TRFIA) was developed for the analysis of paclobutrazol in environmental water and soil samples. Paclobutrazol hapten was synthesized and conjugated to bovine serum albumin (BSA) for producing polyclonal antibodies. Under optimal conditions, the 50% inhibitory concentration (IC50 value) and limit of detection (LOD, IC20 value) were 1.09μgL(-1) and 0.067μgL(-1), respectively. The LOD of TRFIA was improved 30-fold compared to the already reported ELISA. There was almost no cross-reactivity of the antibody with the other structural analogues of triazole compounds, indicating that the antibody had high specificity. The average recoveries from spiked samples were in the range from 80.2% to 104.7% with a relative standard deviation of 1.0-9.5%. The TRFIA results for the real samples were in good agreement with that obtained by high-performance liquid chromatography analyses. The results indicate that the established TRFIA has potential application for screening paclobutrazol in environmental samples.

Increased awareness of phthalic acid esters (PAEs) toxicity has given rise to a dramatic increase in concern about the determination of these contaminations in the environment. In this paper, a sensitive, selective and rapid enzyme immunoassay of ELISA based on polyclonal antibody for detecting butyl benzyl phthalate (BBP) was developed and applied in the environmental water and soil samples. The hapten of BBP was synthesized, then applied to prepare artificial antigen and produce polyclonal antibody capable of specific recognizing BBP. From the optimal standard curve of ELISA for BBP, the values of LOD (limit of detection, IC10) and IC50 were 2.5 and 79.4 ng/mL, respectively. The ELISA showed high specificity, with the cross-reactivity toward BBP analogs

In this communication, 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) funtionalized graphene nanoribbons (HP-β-CD/GNRs) were prepared for the first time by using a simple wet chemical strategy, and then, the HP-β-CD/GNRs were applied for constructing electrochemical sensors for three representative analytes (p-aminophenol, p-AP; l-tyrosine, Tyr; rhodamine B, RhB). Owing to the synergetic effects of GNRs (excellent electrochemical properties and large surface area) and HP-β-CD (high host–guest recognition and enrichment capability), the highly sensitive electrochemical sensing platforms of three analytes were established by using HP-β-CD/GNRs modified electrode, and the detection limits were 0.0008, 0.003, and 0.001 μM for p-AP, Tyr, and RhB, respectively. Keywords: Graphene nanoribbon, Cyclodextrin, Electrochemical sensor, p-Aminophenol, l-Tyrosine, Rhodamine B

Owing to the harmful nature of 4-nitrochlorobenzene (4-NCB, one toxic organic pollutant) and the low cost, high sensitivity and ease of operation of electrochemical method, it is highly desirable to develop effect electrochemical sensor for the detection of 4-NCB. Herein, by partially unzipping carbon nanohorns (CNHs) via a simple wet-chemistry method, CNHs and graphene oxide (GO) (CNHs/GO) nanohybrids were produced for sensing 4-NCB with synergistic properties. While the retained CNHs offer a path for rapid electron transport, the GO sheets formed by partially unzipping CNHs provide abundant active sites, further increase in surface area as well as improved dispersibility of the CNHs/GO. Our results show that the CNHs/GO modified electrode has excellent sensitivity to 4-NCB with a wide linear response range and a detection limit as low as 10 nM.

Leptin is an adipocyte-derived hormone and maintains adipose function under challenged conditions. Autophagy is also essential to maintain cellular homeostasis and regulate characteristics of adipose tissue. However, the effects of leptin on autophagy of adipocyte remain elusive. Here, we demonstrated endoplasmic reticulum (ER) stress and leptin were correlated with autophagy and inflammation by transcriptome sequencing of adipose tissue. Leptin-mediated inhibition of autophagy was involved in upstream reduction of ER stress proteins such as Chop, GRP78, and Atf4, since blockage of autophagy using pharmacological approach had no effect on tunicamycin-induced ER stress. Moreover, we determined KLF4, the potential transcriptional factor of Atf4, was required for the leptin-mediated autophagy in the regulation of adipocyte inflammation. Importantly, ATF4 physically interacted with ATG5 and subsequently formed a complex to promote adipocyte autophagy. Further analysis revealed that Atg5, a core component of autophagosome, was the target for leptin-mediate autophagy. In addition, leptin alleviated ER stress-induced inflammation by reducing autophagy-mediated degradation of IκB in adipocytes. Exogenous leptin treatment also ameliorated autophagy and inflammation of white adipose tissue in ob/ob mice. Taken together, our results indicated that leptin inhibited ER stress-mediated autophagy and inflammation through the negatively regulation of Atf4/Atg5 complex in adipocytes. These findings identify a new potential means for intervention of autophagy to prevent or treat obese caused metabolic syndrome of mammals.

The suppressor of cytokine signaling 3 (SOCS3) is an established negative feedback regulation transcription factor associated with leptin, tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ) and growth hormone (GH). However, the regulatory mechanism of SOCS3 on inflammation and apoptosis of adipocyte is still not clear. In this study, we found an increased expression of adipocyte inflammatory cytokines TNF-α and IL-6 due to leptin treatment. Meanwhile Caspase3, a key executioner of apoptosis, was also elevated in this process. In addition, we observed that SOCS3 could promote inflammation whereas SOCS3 interference reversed this effect in LPS-induced adipocytes inflammatory model. Moreover, the expression of apoptosis-associated genes Bax, cleaved-Caspase9 and cleaved-Caspase3 were elevated along with decreased Bcl-2 expression as detected with Western blot and ELISA assay. The phosphorylation level of JAK2/STAT3 signal was inhibited by SOCS3 along with the elevated expression of IL-6, TNF-α and Caspase3. We also demonstrated that stable knockdown of SOCS3 along with SD1008, a specific inhibitor of JAK2/STAT3 signaling pathway, could significantly inhibit inflammation and apoptosis of adipocyte. Altogether, these results inferred that SOCS3 promotes adipocyte apoptosis by both aggravating inflammation and inhibiting the activity of JAK2/STAT3 signaling pathway.

Multiwalled carbon nanotubes (MWCNT) were covered with reduced graphene oxide nanoribbons (rGONR) to give a material with a core-shell heterostructure of the type MWCNT@rGONR. It was obtained by (a) longitudinal partial unzipping of MWCNT to form MWCNT@GONR, and (b) subsequent chemical reduction with hydrazine to give MWCNT@rGONR. The MWCNT@rGONR heterostructure was used to modify a glassy carbon electrode (GCE) to obtain an electrochemical sensor for p-dihydroxybenzene (DHB). The synergistic effects of the MWCNT and the rGONR results in a distinctly improved redox current towards DHB compared to a bare GCE, an MWCNT/GCE, and an MWCNT@GONR/GCE. At the working voltage range from −100 to 400 mV, it displays a linear response to DHB in the 80 to 3000 nM concentration range with a 20 nM detection limit.

Alpha melanocyte stimulating hormone (α-MSH) and Forkhead box C2 protein (Foxc2) enhance lipolysis in multiple tissues. However, their relationship in adipose fatty acid oxidation (FAO) remains unclear. Here, we demonstrated that α-MSH and Foxc2 increased palmitate oxidation to CO2 in white (WAT) and brown adipose tissue (BAT). C/EBPβ expression was reduced by α-MSH and Foxc2. FFA level was elevated by α-MSH and pc-Foxc2 treatment along with increased FAO in white and brown adipocytes. The expression of FAO key enzymes, medium-chain acyl-CoA dehydrogenase (MCAD) and long-chain acyl-CoA dehydrogenase (LCAD) were increased in α-MSH and pc-Foxc2 group. Combination of α-MSH and Foxc2 treatment synergistically promoted FAO through increasing the activity of CPT-1 and phosphorylation of ACC. We found C/EBPβ bind to MC5R and Foxc2 promoter regions and inhibited FAO. cAMP level was increased by α-MSH and Foxc2 individually treated or combined treatment. Furthermore, cAMP/PKA pathway-specific inhibitor (H89) blocked the FAO, despite in α-MSH and Foxc2 both added group. While forskolin, the cAMP agonist, promoted FAO and enhanced the effect of α-MSH and Foxc2. Collectively, α-MSH and Foxc2 mutual promote FAO in WAT and BAT via cAMP/PKA signal pathway. And C/EBPβ as a transcription suppressor inhibits α-MSH and Foxc2 expression and FAO.

A simple and signal-amplified, label-free electrochemical impedimetric immunosensor for dibutyl phthalate (DBP), a type of phthalate ester, was developed using gold nanoparticles (AuNPs) induced signal amplification. The approach was based on an indirectly competitive binding system of coating antigen that coated on antigen/chitosan/MWCNTs@GONRs/GCE (modified electrodes), target (DBP) and anti-DBP antibody. Signal amplification was performed via the enlargement of AuNPs through NADH-promoted catalytic precipitation, which caused a marked increase in the electron-transfer resistance and electrostatic repulsion after an AuNP-labeled second antibody conjugated to anti-DBP. Under the optimized conditions, this method displayed: (i) low detection limits (7 ng/mL, 10 times lower than the traditional ELISA method using the same antibody); (ii) satisfactory accuracy (recoveries, 86.0–120.4%) and agreement with corresponding ELISA method; (iii) high tolerance to some environmental interferents; and (iv) low cost and low sample consumption (6 µL). Our results demonstrate the great potential and high efficiency of this immunosensor in practical applications for the cost-effective and sensitive monitoring of DBP in aquatic environments.

An enzyme-linked immunosorbent assay (ELISA) was developed based on a polyclonal antibody for the analysis of thiacloprid in agricultural samples. Thiacloprid hapten was synthesized and conjugated to bovine serum albumin to produce an immunogen and ovalbumin to produce a coating antigen. Polyclonal antibodies were obtained from immunized New Zealand white rabbits. Under optimal conditions (5 % methanol, 0.1 mol/L Na+, pH 5.5), the ELISA showed a 50 % inhibitory concentration (IC50) value of 0.01 mg/L and a limit of detection (IC10) of 0.47 μg/L. No obvious cross-reaction with the other structural analogs of neonicotinoid insecticides showed that the polyclonal antibodies had a high specificity for thiacloprid. The average recoveries from spiked water, soil, pear, and tomato were in the range of 80 to 119 %. The results of the ELISA were confirmed by high-performance liquid chromatography, and the correlation of the results from the two methods had a high correlation coefficient of 0.99 (n = 3) in spiked samples (soil, pear, and tomato). The proposed ELISA could successfully be applied to the determination of thiacloprid residues in agricultural samples.

Cardiovascular disease associated with oxidative stress, including atherosclerosis, is the leading cause of mortality worldwide. The accelerated proliferation and migration of vascular smooth muscle cells are the predominant characteristics of atherogenesis, and endothelial dysfunction is a major risk factor for the pathogenesis of atherosclerosis. Podocalyxin (PODXL), a type I member of the cluster of differentiation 34 family of sialomucins, functions as a pro-adhesive molecule. Emerging evidence has revealed the importance of micro (mi)RNAs in the cardiovascular system. The present study demonstrated that there was an inverse association between miRNA (miR)-125b and PODXL in human umbilical vein endothelial cells and human aortic vascular smooth muscle cells (HAVSMCs) treated with oxidized low‑density lipoprotein (LDL) and platelet derived growth factor. Additionally, miR-125b had a suppressive function in cell proliferation and migration, at least partially via targeting PODXL in the HAVSMCs. Furthermore, the data suggested that the functions of miR-125b in arteriosclerosis obliterans may be associated with transgelin, lectin-type oxidized LDL receptor-1, vascular endothelial-cadherin, intercellular adhesion molecule-1, interleukin-6 and monocyte chemotactic protein-1. In conclusion, miR-125b was found to be important in arteriosclerosis obliterans by suppressing the expression of PODXL and may serve as a potential therapeutic target for the treatment of arteriosclerosis obliterans.

Obesity is associated with macrophage infiltration and metabolic inflammation, both of which promote metabolic disease progression. Melatonin is reported to possess anti-inflammatory properties by inhibiting inflammatory response of adipocytes and macrophages activation. However, the effects of melatonin on the communication between adipocytes and macrophages during adipose inflammation remain elusive. Here, we demonstrated melatonin alleviated inflammation and elevated α-ketoglutarate (αKG) level in adipose tissue of obese mice. Mitochondrial isocitrate dehydrogenase 2 (Idh2) mRNA level was also elevated by melatonin in adipocytes leading to increase αKG level. Further analysis revealed αKG was the target for melatonin inhibition of adipose inflammation. Moreover, sirtuin 1 (Sirt1) physically interacted with IDH2 and formed a complex to increase the circadian amplitude of Idh2 and αKG content in melatonin-inhibited adipose inflammation. Notably, melatonin promoted exosomes secretion from adipocyte and increased adipose-derived exosomal αKG level. Our results also confirmed that melatonin alleviated adipocyte inflammation and increased ratio of M2 to M1 macrophages by transporting of exosomal αKG to macrophages and promoting TET-mediated DNA demethylation. Furthermore, exosomal αKG attenuated signal transducers and activators of transduction-3 (STAT3)/NF-κB signal by its receptor oxoglutarate receptor 1 (OXGR1) in adipocytes. Melatonin also attenuated adipose inflammation and deceased macrophage number in chronic jet-lag mice. In summary, our results demonstrate melatonin alleviates metabolic inflammation by increasing cellular and exosomal αKG level in adipose tissue. Our data reveal a novel function of melatonin on adipocytes and macrophages communication, suggesting a new potential therapy for melatonin to prevent and treat obesity caused systemic inflammatory disease.

Pyroptosis is a proinflammatory form of cell death that is associated with pathogenesis of many chronic inflammatory diseases. Melatonin is substantially reported to possess anti-inflammatory properties by inhibiting inflammasome activation. However, the effects of melatonin on inflammasome-induced pyroptosis in adipocytes remain elusive. Here, we demonstrated that melatonin alleviated lipopolysaccharides (LPS)-induced inflammation and NLRP3 inflammasome formation in mice adipose tissue. The NLRP3 inflammasome-mediated pyroptosis was also inhibited by melatonin in adipocytes. Further analysis revealed that gasdermin D (GSDMD), the key executioner of pyroptosis, was the target for melatonin inhibition of adipocyte pyroptosis. Importantly, we determined that nuclear factor κB (NF-κB) signal was required for the GSDMD-mediated pyroptosis in adipocytes. We also confirmed that melatonin alleviated adipocyte pyroptosis by transcriptional suppression of GSDMD. Moreover, GSDMD physically interacted with interferon regulatory factor 7 (IRF7) and subsequently formed a complex to promote adipocyte pyroptosis. Melatonin also attenuated NLRP3 inflammasome activation and pyroptosis, which was induced by LPS or obesity. In summary, our results demonstrate that melatonin alleviates inflammasome-induced pyroptosis by blocking NF-κB/GSDMD signal in mice adipose tissue. Our data reveal a novel function of melatonin on adipocyte pyroptosis, suggesting a new potential therapy for melatonin to prevent and treat obesity caused systemic inflammatory response.

Adiponectin is a cytokine produced predominantly by adipose tissue and correlates with glucose and lipid homeostasis. However, the effects of adiponectin on endoplasmic reticulum (ER) stress and apoptosis of adipose tissue remain elusive. In this study, we found that tunicamycin-induced ER stress increased serum free fatty acid (FFA) and impaired glucose tolerance, elevated the mRNA levels of GRP78, Chop, ATF2 and caspase 3, but reduced adiponectin mRNA level in white adipose tissue. Moreover, ER stress-triggered adipocyte apoptosis by increasing cellular FFA level and Ca2+ level. Further analysis revealed that adiponectin alleviated ER stress-induced adipocyte apoptosis by elevating peroxisome proliferator-activated receptor alpha (PPARα) mRNA level. Our data also confirmed that adiponectin reduced early apoptotic cells and blocked the mitochondrial apoptosis pathway by activating the AdipoR1/AMP-activated protein kinase (AMPK) signal pathway. In addition, PPARα bound to ATF2 promoter region and inhibited transcription of ATF2. The inhibition of adipocyte apoptosis by adiponectin was correlated with transcriptional suppression of ATF2. Furthermore, adiponectin inhibited ER stress-induced apoptosis by activating the AMPK/PKC pathway. In summary, our data demonstrate adiponectin inhibited ER stress and apoptosis of adipocyte in vivo and in vitro by activating the AMPK/PPARα/ATF2 pathway. Our study establishes that adiponectin is an important adipocytokine for preventing and treating obesity.

An indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) has been developed for detection of pretilachlor in water and soil. An immunogen was prepared from haptens of pretilachlor conjugated to bovine serum albumin(BSA). The specific polyclonal antibodies were obtained by immunizing New Zealand white rabbits. The influence of parameters including concentrations of methanol, ionic strength and pH values were optimized to improve the sensitivity of the assay. The optimized ELISA was shown to have a high sensitivity and specificity for pretilachlor. Under optimal conditions, the ELISA has demonstrated an 50% inhibitory concentration (IC50) value of 0.0359 mg/L with a limit of detection (LOD, IC10) of 6.9 ng/L. The cross-reactivities to some analogs of pretilachlor (acetochlor, butachlor, metazachlor and metalaxyl) were below 1.5%. The average recoveries of pretilachlor from distilled water, tap water, paddy water and soil were in the range of 77.0–115.2% between 0.005 and 5.0 mg/L. The results of ELISA for spiked samples were confirmed by GC–ECD with a high correlation coefficient of 0.9950(n=11). Thus, the ELISA proven to be a sensitive, specific, inexpensive and quantitative tool for detection of pretilachlor from four kinds of spiked samples.