3D nanocake-like Au-MXene/Au pallet structure-based label-free electrochemical aptasensor for paraquat determination.

3D nanocake-like Au-MXene and Au pallet (Au-MXene/AuP) nanocomposite-modified screen-printed carbon electrodes (SPCEs) were utilized to construct an ultrasensitive label-free electrochemical aptasensor through a self-assembly procedure for trace paraquat (PQ) residue detection. Benefiting from the excellent electrochemical (EC) performances (e.g., high conductivity and large surface area) of Au-MXene nanocomposites and AuP substrate, the developed Apt/Au-MXene/AuP/SPCE-based EC aptasensor displayed excellent specificity and anti-interference ability, good repeatability, and stability. A linear relationship between the log value of the change in current intensity [lg (ΔI)] and the log value of the concentration of PQ [lg (CPQ)] was obtained in the range 0.05-1000 ng/mL. The limit of detection was 0.028 ng/mL, and the sensitivity was 255.5 µA/(µM·cm2). Practical applications in malt and mint samples confirmed the accuracy of the EC aptasensor in complex matrices for PQ detection, providing a universal analytical tool for other trace pesticides in different food samples by simply replacing the corresponding aptamers.

Multi-mycotoxin detection and human exposure risk assessment in medicinal foods.

Mycotoxin contamination in medicinal foods has attracted increasing global attention. In this study, a simple and sensitive ultrasonication assisted one-step extraction based ultra-fast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS) method was developed for simultaneous detection of multi-mycotoxins in five kinds of medicinal foods rich in starch. Under optimal conditions, the developed technique displayed excellent analytical performances. Limits of detection and quantitation for the six mycotoxins were 0.04-0.25 ng/mL and 0.10-0.67 ng/mL, respectively. Average recoveries at three fortified levels ranged from 75.33 % to 118.0 %. Real-world application in 103 batches of medicinal foods displayed that 58 samples were positive with one or more mycotoxins at an occurrence rate of 56.31 % (58/103). Coix seed gave the highest positive rate of 96.15 %, followed by Lily (90 %), Chinese yam (50 %), Lotus seed (34.04 %) and Malt (30 %). Zearalenone had the highest positive rate of 28.16 % with contents in 5 Coix seeds exceeding the maximum residue limit (MRL), followed by aflatoxin B1 of 27.18 % (28/103) with contents in 7 Coix seed and 10 Lotus seeds over its MRL, and ochratoxin A (OTA) of 11.65 % with contents in 1 Lotus seed and 5 Lily samples greater than its MRL. Exposure risk assessment indicated that Coix seed and Lotus seeds that were susceptible to aflatoxins posed great threats to human health. Long-term consumption of Lily that was easily contaminated with OTA were also harmful. This work provides a robust platform for multi-mycotoxin monitoring in medicinal foods to protect the consumers from potential health risks.

Ultrasensitive electrochemical aptasensor with Nafion-stabilized f-MWCNTs as signal enhancers for OTA detection.

In this study, an ultrasensitive electrochemical (EC) aptasensor with Nafion-stabilized functionalized multi-walled carbon nanotubes (f-MWCNTs) as signal enhancers was established for ochratoxin A (OTA) determination. Herein, f-MWCNTs were prepared through functionalization with nitric acid. The incorporation of Nafion promoted a good dispersion of f-MWCNTs and prevented their leaching on the electrode, making a robust stability of the aptasensor. The Nafion-f-MWCNTs composites were used as the sensing substrates to largely enhance the electroactive surface area and the conductivity of the electrode, realizing a significant signal amplification. Carboxyl groups on the surface of f-MWCNTs readily exposed from Nafion membrane to couple with streptavidin, facilitating the immobilization of biotinylated aptamers to achieve selective recognition towards OTA. When OTA existed, aptamers preferentially combined with it, causing a noticeable decline in the current response. Under optimum conditions, a good linear relationship between the current changes and the logarithm of OTA concentration was observed from 0.005 ng/mL to 10 ng/mL, with a limit of detection low to 1 pg/mL for OTA. The specific, sensitive, and reproducible aptasensor succeeded in application in malt samples, confirming a great promise for more contaminants and providing a universal platform in complex matrices by simply replacing the corresponding aptamers.

Development of a Nafion-MWCNTs and in-situ generated Au nanopopcorns dual-amplification electrochemical aptasensor for ultrasensitive detection of OTA.

Trace detection of ochratoxin A (OTA) in foods is essential to mitigate risks to human health. Herein, a label-free electrochemical (EC) aptasensor based on dual-signal amplification of Nafion dispersed multi-walled carbon nanotubes (Nafion-MWCNTs) and Au nanopopcorns was developed for ultrasensitive detection of OTA. Nafion solution prevented the leaching of MWCNTs, and the Nafion-MWCNTs modified screen-printed carbon electrode (SPCE) acted as the sensing substrate which facilitated the uniform distribution of the electrodeposited Au nanopopcorns. The in-situ generated Au nanopopcorns could not only load a large amount of aptamers for specific identification of OTA, but also promote the electron transfer of the sensing platform. The incorporation of Nafion-MWCNTs and Au nanopopcorns realized dual-amplification of the aptasensor due to the enhanced conductivity and the increased electroactive surface area of the electrode. The modified electrodes were characterized through scanning electron microscopy, X-ray photoelectron spectroscopy and EC evaluation. Under optimal conditions, the electrochemical impedance spectroscopy (EIS) was measured for the determination of OTA. The as-fabricated Au nanopopcorns/Nafion-MWCNTs impedimetric aptasensor displayed excellent sensitivity with a detection limit as low as 1 pg/mL and a wide linear range of 1 pg/mL-10 ng/mL for OTA. Practical application of the aptasensor in the spiked malt samples achieved satisfactory recoveries of 89.82-95.65 %, which was also successfully verified to detect OTA in eleven batches of actual malt samples collected from the local market. The creative aptasensor is simple, cost-effective, sensitive, and accurate, showing great promise for on-site monitoring of other trace contaminants in foods by simply replacing the aptamers.

Single-Molecule Real-Time Sequencing to Explore the Mycobiome Diversity in Malt.

This study determined the composition of fungal communities and characterized the enriched fungal species in raw and roasted malts via the third-generation PacBio-based full-length single-molecule real-time (SMRT) sequencing of the full-length amplicon of the internal transcribed spacer (ITS) region. In total, one kingdom, six phyla, 23 classes, 56 orders, 120 families, 188 genera, 333 species, and 780 operational taxonomic units (OTUs) were detected with satisfactory sequencing depth and sample size. Wickerhamomyces (56%), Cyberlindnera (15%), Dipodascus (12%), and Candida (6.1%) were characterized as the dominant genera in the raw malts, and Aspergillus (35%), Dipodascus (21%), Wickerhamomyces (11%), and Candida (3.5%) in the roasted malts. Aspergillus proliferans, Aspergillus penicillioides, and Wickerhamomyces anomalus represented the crucial biomarkers causing intergroup differences. Correlation analysis regarding environmental factors indicated that the water activity (aw) of the samples affected the composition of the fungal communities in the malts. In practice, special attention should be paid to the mycotoxin-producing fungi, as well as other fungal genera that are inversely correlated with their growth, to ensure the safe use of malt and its end products. IMPORTANCE Fungal contamination and secondary metabolite accumulation in agricultural products represent a global food safety challenge. Although high-throughput sequencing (HTS) is beneficial for explaining fungal communities, it presents disadvantages, such as short reads, species-level resolution, and uncertain identification. This work represents the first attempt to characterize the fungal community diversity, with a particular focus on mycotoxin-producing fungi, in malt via the third-generation PacBio-based full-length SMRT sequencing of the ITS region, aiming to explore and compare the differences between the fungal communities of raw and roasted malts. The research is beneficial for developing effective biological control and conservation measures, including improving the roasting conditions, monitoring the environmental humidity and aw, and effectively eliminating and degrading fungi in the industry chain according to the diverse fungal communities determined, for the safe use of malts and their end products, such as beers. In addition, the third-generation SMRT sequencing technology allows highly efficient analysis of fungal community diversity in complex matrices, yielding fast, high-resolution long reads at the species level. It can be extended to different research fields, updating modern molecular methodology and bioinformatics databases.

Transfer behavior of pesticides from honeysuckle into tea infusions: Establishment of an empirical model for transfer rate prediction.

Affected by some external conditions and internal factors, pesticides can be transferred from tea into its infusion, causing subsequent damage to humans as tea infusion is generally consumed. This study aimed to explore the inherent regularity in transfer behavior of 23 pesticides belonging to different classes from honeysuckle to its tea infusion, and to understand the effects of external brewing conditions and internal physicochemical parameters of the pesticides on their transfer rates. Results indicated that the transfer rates (Rt) of pesticides from honeysuckle into tea solutions increased with prolonged brewing time, or adding a cover on a container, but decreased with increasing the times of infusion. In addition, the transfer potential of these pesticides greatly depended on their physicochemical properties but not their type. The pesticides with high water solubility and low water partition coefficient (LogKow, e.g., omethoate) were more easily transferred into tea infusions than those with low water solubility and high LogKow (e.g., chlorpyrifos). Compared the tea brewing in a covered container, the empirical models obtained in an uncovered cup predicted the transfer behavior and drinking risk of pesticides potentially introduced into honeysuckle and its tea infusion. The linear equation was as follow: Rt = 10.756 LogWS + 7.517, R = 0.8771. In practice, honeysuckle should be brewed in an uncovered cup within a short brewing time, and the first tea infusion should be abandoned to reduce the transfer percentage of pesticides. This study provided beneficial references for pesticide application in honeysuckle plantation to establish realistic maximum residue limits of multi-pesticides in honeysuckle tea and related products.

Fungal communities in Nelumbinis semen characterized by high-throughput sequencing.

For a long period, Nelumbinis semen has been widely used as a medicinal and edible product. However, it is susceptible to contamination with toxigenic fungi and aflatoxins during the growth, collection, transportation, and storage processes, causing serious health threats to humans and huge economic losses. Effectively monitoring the fungal communities is of great importance to avoid aflatoxins contamination in Nelumbinis semen. High-throughput sequencing (HTS) is a new technology to evaluate fungal communities so as to overcome the limitations of the traditional cultural ways. In this study, the ITS2 based Illumina-MiSeq platform was developed to evaluate the fungal communities in normal and moldy Nelumbinis semen by using the HTS technology. Two different primer pairs were introduced to compare their performance in amplifying the target gene. The primer pair that produced more reads was selected to analyze the results. In all the nine tested Nelumbinis semen samples, 2 phyla, 5 classes, 6 orders, 8 families, 9 genera and 4 species were detected. A total of 9 genera were spotted, of which, Aspergillus (0.04%-72.93%) and Rhizopus (0.002%-48.12%) were the most dominant. ANOISM analysis showed no significant differences in the normal and moldy groups. The use of HTS technology can detect the fungal communities in complex Nelumbinis semen samples, providing an early warning for toxigenic fungi and aflatoxins contamination to warrant their quality and safety.

Genetic polymorphisms of human hepatic OATPs: functional consequences and effect on drug pharmacokinetics.

1. Organic anion transporting polypeptides (OATPs) belong to the superfamily of solute carriers (SLC), which are important membrane transporters in animals and humans. Liver is an important organ for drug disposition. In human liver, three OATPs, namely OATP1B1, 1B3 and 2B1, are expressed on the basolateral membrane of hepatocytes.2. OATPs have multiple substrate specificity, mediating transport of a wide range of endo- and exogenous substances such as bile salts, bilirubin, hormones and their conjugates, toxins and various drugs. Therefore, they are important for drug disposition in human body. In this review, we compiled a complete list of the substrates for human hepatic OATPs.3. OATP genes have single-nucleotide polymorphisms (SNPs), which could lead to the alteration of their function, and thus might result in the change of pharmacokinetic properties for their substrate drugs. In this review, we summarized the genetic polymorphisms of the three hepatic OATPs and their effect on in vitro transport function and in vivo pharmacokinetics of substrate drugs.4. Finally, some concerns and perspectives on OATP polymorphism research are discussed.

Development and evaluation of gamma-interferon sandwich ELISA kit in herds infected with Mycobacterium bovis / 中国人兽共患病学报

This study was aimed to develop a sandwich ELISA kit for the diagnosis of bovine tuberculosis.And it was applied and evaluated in the quarantine of bovine tuberculosis.We established a bovine IFN-γ release method in vitro and developing three batches of kits.The sensitivity,repeatability and retention period of the kit were all evaluated.Totally 961 serum samples were tested using the developed sandwich ELISA kit tuberculin skin test and a commercial ELISA kit.Our results showed that the detection limit of this ELISA was 8.21 mg/mL.The repeatability tests showed good reproducibility in the intraassay and inter-assay.At the same time,the retention period of the kit was more than 12 months.Compared with the tuberculin skin test,the positive coincidence rate was 70.59％ and the negative coincidence rate was 99.20％,while the total coincidence rate was 98.44％.And compared with the BOVIGAMTM kit,the positive coincidence rate was 91.30％ and the negative coincidence rate was 99.78％,while the total coincidence rate reached 99.58％.At the same time,the sensitivity and specificity of the sandwich kit were 85.00％ and 100％,respectively.We established a bovine IFN-γ release method in vitro and developing corresponding kits successfully have a good application prospect.

Intestinal Parasite Infections among Inhabitants in Yanbian Prefecture, Jilin Province, China

To investigate the prevalence of intestinal parasite infections in Yanbian Prefecture, Jilin Province, China, epidemiological surveys were conducted on a collaboration basis between the Korean Centers for Disease Control and Prevention and the Yanbian Center for Disease Control and Prevention. A total of 8,396 (males 3,737 and females 4,659) stool samples were collected from 8 localities and examined with the formalin-ether sedimentation technique, and additionally examined with the cellotape anal swab to detect Enterobius vermicularis eggs. The overall rate of intestinal parasites was 1.57%. The prevalence of Ascaris lumbricoides was the highest (0.80%), followed by Entamoeba spp. (0.23%), heterophyid flukes (0.15%), Clonorchis sinensis (0.08%), Enterobius vermicularis (0.07%), hookworms (0.06%), Trichostrongylus spp. (0.06%), Giardia lamblia (0.04%), Paragonimus spp. (0.02%), Diphyllobothrium spp. (0.02%), Trichuris trichiura (0.02%). The prevalence by sex was similar, 1.58% (n=59) in males and 1.57% (n=73) in females. By the present study, it is partly revealed that the prevalences of intestinal parasite infections are relatively low among the inhabitants of Yanbian Prefecture, Jilin Province, China.

C-reactive protein decreases interleukin-8 production in human endothelial progenitor cells by inhibition of p38 MAPK pathway / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>C-reactive protein (CRP) has been reported to damage the vascular wall by inducing endothelial dysfunction and inflammation, and it is also speculated to have a role in attenuating angiogenic functions of human endothelial progenitor cells (EPCs). Interleukin-8 (IL-8) is an important mediator of the paracrine mitogenic effect of EPCs, which has direct angiogenic effects on mature endothelial cells. We, herein, investigated the direct effect of CRP on IL-8 production and gene expression in cultured human EPCs.</p><p><b>METHODS</b>EPCs were isolated from the peripheral venous blood of healthy male volunteers. Cells were cultured in EndoCult liquid medium in the absence and presence of CRP at clinically relevant concentrations (5 to 25 microg/ml) for different durations (3 to 48 hours). IL-8 protein and mRNA of cultured EPCs were evaluated using ELISA and real-time PCR.</p><p><b>RESULTS</b>The results showed that CRP at a concentration of 10 microg/ml significantly reduced IL-8 secretion of cultured EPCs with a peak at 25 microg/ml, and also decreased mRNA expression in EPCs with a peak at 12 hours. In addition, preincubation of EPCs with SB203580, an inhibitor of p38 mitogen-activated protein kinase (MAPK) decreased CRP inhibition of IL-8 mRNA expression at 12 hours in EPCs.</p><p><b>CONCLUSIONS</b>Our study, for the first time, demonstrates that CRP directly inhibits EPCs IL-8 secretion, a key cytokine player of angiogenesis induced by EPCs. Inhibition occurred in part via an effect of CRP to active the p38 MAPK signal transduction pathway in EPC. The ability of CRP to inhibit EPCs IL-8 secretion may represent an important mechanism that further links inflammation to cardiovascular disease.</p>

Autologous peripheral blood stem cell transplantation for the treatment of lower extremity arterial occlusive disease / 中华心血管病杂志

<p><b>OBJECTIVE</b>To evaluate the safety and feasibility of autologous peripheral blood mononuclear cells (PBMNCs) implantation after granulocyte-colony stimulating factor (G-CSF)-induced mobilization in patients with lower extremity arterial occlusive disease (AOD).</p><p><b>METHODS</b>A total of 12 patients with AOD were enrolled in this study. Following administration of rhG-CSF (150 microg/d) for 5 days, PBMNCs were harvested and injected intramuscularly in the diseased extremities (3 x 10(9) per limb).</p><p><b>RESULTS</b>One patient received left leg amputation due to uncontrolled ulcer 15 days post PBMNCs transplantation and the symptoms and signs were improved significantly in 9 patients and the symptoms and signs remained unchanged in another 2 aged patients (> 70 years). Doppler ultrasonography measurement showed that peak systolic velocity in diseased extremities was significantly increased post transplantation [(44.55 +/- 4.13) cm/s vs. (21.32 +/- 0.63) cm/s, P < 0.01]. Contrast lower limb angiogram showed increased collateral vessels post transplantation. One aged patient (80 years) who did not respond to autologous PBMNCs received heterologous PBMNCs transplantation (PBMNCs was harvested from a young relative of him) 3 months post autologous PBMNCs transplantation and observed for another 3 months and all observed parameters improved significantly.</p><p><b>CONCLUSION</b>Implantation of autologous PBMNCs collected after G-CSF administration might offer a simple, safe, and effective therapy for the AOD patients.</p>