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In this study, aflatoxin B1 (AFB1) aptamers were covalently coupled on the surface of magnetic beads to prepare aptamer affinity magnetic beads (AAMBs). Furthermore, the AAMBs, incubation solution, washing solution and eluate were pre-encapsulated in reagent strips to develop a single sample pretreatment kit of AFB1. The automatic pretreatment of AFB1 was realized through the automatic mycotoxin purifier. The content of AFB1 in the eluate was determined by ultra high performance liquid chromatography (UPLC). The preparation conditions of AAMB and the use conditions of AFB1 single sample pretreatment kit were determined by optimizing the particle size of magnetic beads, the indirect arm length of aptamer, the amount of AAMB, and the volume of incubation solution. Recoveries was compared by manual and automatic pretreatment methods. Under the optimized conditions, the limit of detection (LOD) was 25 pg/mL, and the spiked recoveries at low, medium and high levels in corn and wheat ranged from 92.8% to 110.1%, with the relative standard deviation (RSD) of intra-day precision less than 5.1% and the RSD of 6.7% in term of inter-day precision, which showed good sensitivity, accuracy and repeatability. The results of AFB1 in the national certified reference materials of grain and oil substrates (corn, brown rice, peanut oil and peanut butter) were within their extended uncertainty range. The single sample pretreatment kit developed could automatically complete the pretreatment of 10 samples within 20 min with the aid of mycotoxin automated purification instrument. This method has the advantages of short time, high throughput, small batch-to-batch variation and no need of cold chain storage and transportation. It has a good application prospect in the quantitative detection of mycotoxins, and could lay a foundation for the development of automatic pretreatment methods for other targets.

By contrasting the main indexes of maize quality standards in China, the United States, Australia and Canada, which are the representative countries in APEC and combined with the actual test results of samples analysis, it is expected to provide a reference for the interconnection of international maize trade standards. The maize quality standards of these four countries all take the unit weight, impurities and imperfect grains (damaged grains) as the main indicators of maize grading. In terms of quota setting, the characteristics of domestic maize circulation are fully considered, and the indicator systems have their own distinctive characteristics based on their own corn production, storage and trade practices. The indicator systems have their own distinctive characteristics, including the definition of maize unit weight, imperfect grains, impurities and other indicators, measuring instruments, measuring methods and quality requirements. When the same samples were tested and judged by different standards, the quality results and quality grades were different, leading to the results being lack of comparability. It is suggested that strengthen communication and coordination among international peers, unify terms and definitions, testing instruments, testing methods should be included to improve trade efficiency, reduce trade costs and promote trade facilitation of maize in the international maize trade and circulation.

In order to meet the needs of rapid quantitative detection of fumonisin B1 (FB1) in grains, this paper takes fumonisin B1 as the research object, and creates a rapid quantitative detection card of FB1 on the basis of time-resolved fluorescent nanospheres, with no need to adjust the PH of samples before detection. The detection performance of the detection card in grains (rice, corn, wheat) was analyzed and compared with enzyme-linked immunosorbent assay kit and high performance liquid chromatography. The LOD for different samples was in the range of 35.37~37.17 μg/kg, and the LOQ was 117.9~123.9 μg/kg, which meant good sensitivity; the linear range was 250~6 000 μg/kg, while the correlation coefficient R2 was in the range of 0.997 2~0.999 5; the spiking recoveries at 6 spiked levels in different samples were in the range of 83.38%~114.66%, with the coefficient of variation (CV) less than 15%, which meant good accuracy and repeatability. When the national standard liquid chromatography and FB1 fluorescence quantitative rapid detection card simultaneously detects different samples contaminated by FB1, the coincidence of the detection results was in the ranger of 92.53%~106.26%, with the CV less than 10.37%. The cross-reaction rate of other five common mycotoxins was less than 5%. Meanwhile, the difference between the spiked concentration and their average detected concentration was extremely significant, indicating good specificity. Hence, the FB1 fluorescence quantitative detection card prepared in this study could meet the needs of on-site rapid quantitative detection of fumonisin B1 in grains.

Obtaining reliable species identification of the legume genus Caragana has been challenging. Until now, species identification was mostly carried out utilizing diagnostic morphological characteristics, in addition to some successful applications of secondary chemical compounds. This study was designed to establish a DNA barcoding protocol enabling unambiguous identification of 238 accessions belonging to 67 species of Caragana. The performance of four DNA barcoding regions nrITS, trnH‐psbA, matK, and rbcL was explored using three analytical approaches, Pairwise Genetic Distance, Sequence Similarity and Phylogenetic Tree method. The chloroplast regions rbcL and matK showed lower discriminatory power compared with the nuclear region internal transcribed spacer (ITS) and the chloroplast region trnH‐psbA. The nrITS outperformed the other regions in the resolution rate. The present study brings forth an efficient barcode locus for Caragana. A barcode based either on a single‐locus nrITS or the combination of nrITS and trnH‐psbA was found to be most suitable for species discrimination with distinctive barcoding gaps. An attempt has also been made to resolve taxonomic issues in the Caragana opulens complex. DNA barcoding tools when complemented with alpha taxonomic evidence can aid in solving complex systematic problems, especially when taxa are characterized by overlapping traits, such as species belonging to the Fabaceae family. [ABSTRACT FROM AUTHOR]

The objection was to evaluate the applicability of an automated method for aflatoxins analysis by using Immunoaffinity Magnetic Bead - UPLC. The results showed that the average recovery of the mmunoaffinity Magnetic Bead was above 95%, and the relative standard deviation was less than 3.3%. The results of the quality control samples were within the range of the reference uncertainty. The method was accurate and reliable.T testing (sig. (bilateral) = 0.533) proved that there was no significant difference between two independent purification instruments.62 researchers evaluated two methods of purifications with immunomagnetic beads and immunoaffinity column. T testing has proved that the results of the two methods were no significant difference.However, the dispersion degree of the immunomagnetic bead automated processing method was smaller than that of the immunoaffinity column method. Moreover, the z-value of all the test were less than 2 (| Z | ≤2). Hence, this method can detect cereals and oils. In addition, the method is environmentally friendly, simply, and lower-cost, which greatly improved detection efficiency and level.

Age-related fibrosis is attenuated by aerobic exercise; however, little is known concerning the underlying molecular mechanism. To address this question, aged rats were given moderate-intensity exercise for 12 weeks. After exercise in aged rats, hydrogen sulfide levels in plasma and heart increased 39.8% and 90.9%, respectively. Exercise upregulated expression of cystathionine [gamma]-lyase and 3-mercaptopyruvate sulfurtransferase in heart of aged rats. Furthermore, aged rats were given moderate-intensity exercise for 12 weeks or treated with NaHS (intraperitoneal injection of 0.1 mL/kg per day of 0.28 mol/L NaHS). After exercise in aged rats, Masson-trichrome staining area decreased 34.8% and myocardial hydroxyproline levels decreased 29.6%. Exercise downregulated expression of collagen-I and [alpha]-smooth muscle actin in heart of aged rats. Exercise in aged rats reduced malondialdehyde levels in plasma and heart and 3-nitrotyrosine in heart. Exercise in aged rats reduced mRNA and protein expression of C/EBP homologous protein, glucose regulated protein 78, and X-box protein 1. Exercise also reduced mRNA and protein expression of interleukin 6 and monocyte chemotactic protein 1and suppressed activation of c-Jun N-terminal kinase in aging heart. Similar effects were demonstrated in aged rats treated with NaHS. Collectively, exercise restored bioavailability of hydrogen sulfide in the heart of aged rats, which partly explained the benefits of exercise against myocardial fibrosis of aged population. Key words: exercise training, fibrosis, heart, aging. La fibrose liee a l'age s'attenue avec l'exercice physique aerobie; cependant, on sait peu de choses des modes d'action moleculaires sous-jacents. Pour aborder cette question, nous avons soumis des rats ages a un exercice physique d'intensite moderee pendant 12 semaines. Apres l'exercice physique, nous avons observe chez les rats ages une augmentation des taux de sulfure d'hydrogene de 39,8 % dans le plasma et de 90,9 % dans le coeur. L'exercice physique entrainait une regulation a la hausse de l'expression de la cystathionine [gamma]-lyase et de la 3-mercaptopyruvate sulfurtransferase dans le coeur des rats ages. De plus, nous avons soumis les rats ages a un exercice physique d'intensite moderee pendant 12 semaines ou a l'administration de NaHS (injection intraperitoneale quotidienne de 0,1 mL/kg de NaHS a 0,28 mol/L). Apres l'exercice physique, nous avons observe chez les rats ages que la surface coloree au trichrome de Masson diminuait de 34,8 %, alors que les taux d'hydroxyproline myocardique diminuaient de 29,6 %. L'exercice physique entrainait une regulation a la baisse de l'expression du collagene I et de l'actine a du muscle lisse dans le coeur des rats ages. Chez les rats ages, l'exercice physique permettait de faire diminuer les taux de malondialdehyde dans le plasma et le coeur, ainsi que les taux de 3-nitrotyrosine dans le coeur. Chez les rats ages, l'exercice physique entrainait une diminution de l'expression en proteines et en ARNm de la proteine homologue C/EBP, de la proteine 78 regulee par le glucose et de la proteine 1 liant la boite X. L'exercice physique entrainait aussi une diminution de l'expression en proteines et en ARNm pour l'interleukine 6 et la proteine 1 chimiotactique des monocytes, avec une inhibition de l'activation de la kinase c-jun N terminale dans le coeur vieillissant. Nous avons montre des effets similaires avec l'administration de NaHS chez les rats ages. Collectivement, l'exercice physique a permis de retablir la biodisponibilite du sulfure d'hydrogene dans le coeur des rats ages, ce qui pourrait s'expliquer en partie par les bienfaits de l'exercice physique contre la fibrose myocardique dans la population agee. [Traduit par la Redaction] Mots-cles : entrainement par l'exercice physique, fibrose, coeur, vieillissement., Introduction Aging is an inevitable trend of the world's population, and it is of central importance as a dominant risk factor for the development of cardiovascular diseases, which account for [...]