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1.
Sci Rep ; 14(1): 15524, 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38969733

ABSTRACT

This study investigates the influence of small control cylinders on the fluid dynamics around a square cylinder using the Lattice Boltzmann Method (LBM). Varying the gaps (L) between the main and control cylinders from 0 to 6, four distinct flow regimes are identified: the solo body regime (SBR), shear layer reattachment (SLR), suppressed fully developed flow (SFDF), and intermittent shedding (IS). The presence of control cylinders results in significant reductions in flow-induced forces, with drag coefficient (CD) and root mean square values of drag and lift coefficients (CDrms and CLrms) decreasing by approximately 31%, 90%, and 81%, respectively. The SFDF flow regime exhibits the lowest fluid forces compared to other regimes. The effects of tiny control cylinders on the fluid flow characteristics of a square cylinder are examined using the Lattice Boltzmann Method (LBM) in this research work. The gaps (L) between the main and control cylinders are varied in the range from 0 to 6. The size of each control cylinder is equal to one-fifth of the primary cylinder. According to the findings, there are four distinct flow regimes as the gap spacing varies: solo body regime (SBR), shear layer reattachment (SLR), suppressed fully developed flow (SFDF), and intermittent shedding (IS) for gap spacing ranges 0 ≤ L ≤ 0.2, 0.3 ≤ L ≤ 0.9, 1 ≤ L ≤ 3, and 3.2 ≤ L ≤ 6, respectively. Additionally, it has been noted that the amplitude of variable lift force is reduced when the gap separation between the main and control cylinders is increased. When compared to solo cylinder values, it is found that the presence of small control cylinders in the flow field results in a considerable reduction of flow-induced forces. The SFDF flow regime was determined to have the lowest fluid forces compared to the other flow regimes studied. Our findings highlight the efficacy of small control cylinders in mitigating flow-induced forces and controlling flow characteristics. The LBM proves to be a valuable computational technique for such fluid flow problems.

2.
Article in English | MEDLINE | ID: mdl-32897821

ABSTRACT

A wide variety of mycotoxins is produced by mycotoxigenic fungi and naturally contaminates food and feed products worldwide. Synergistic effects of multi-toxins are potentially more harmful than exposure to a single compound and can induce acute and chronic toxicity to animals and humans. The aim of the present study is to timely and simultaneously identify the multiple mycotoxigenic fungi capable of causing synergistic toxicity to improve the safety level of food and feedstuff. Here, a multiplex polymerase chain reaction assay was developed for simultaneous detection of mycotoxigenic fungi belonging to the genera Aspergillus, Fusarium and Penicillium. Three pairs of genus-specific primers were designed based on internal transcribed spacer (ITS) sequences of Aspergillus and Penicillium, and Elongation factor 1 alpha (EF- 1α) of Fusarium. Amplicons of 170, 750 and 490 bp respectively for the corresponding primer pairs were detected; thus amplicon length is diagnostic for the individual fungal genus. The sensitivity of the developed method was tested with genomic DNA obtained from mould pure cultures and artificially contaminated maize grain powder. The sensitivity result showed that spore concentrations in the contaminated maize grain powder of 102 spores/mL were detected without prior incubation. This result suggests that the developed mPCR assay would allow a rapid, specific and simultaneous detection of various mycotoxigenic potential fungi based on the occurrence and size of the amplification products and thus to estimate the multi-mycotoxins contamination potential in food and feedstuff.


Subject(s)
Aspergillus/chemistry , DNA, Fungal/analysis , Fusarium/chemistry , Mycotoxins/analysis , Penicillium/chemistry , Base Sequence , Biosensing Techniques , Consumer Product Safety , DNA Primers , Edible Grain/chemistry , Food Contamination/analysis , Humans , Multiplex Polymerase Chain Reaction , Reproducibility of Results , Sensitivity and Specificity , Zea mays/chemistry
3.
J Sci Food Agric ; 99(11): 4869-4877, 2019 Aug 30.
Article in English | MEDLINE | ID: mdl-30868594

ABSTRACT

Mycotoxins are secondary fungal metabolites produced by certain types of filamentous fungi or molds, such as Aspergillus, Fusarium, Penicillium, and Alternaria spp. Mycotoxins are natural contaminants of agricultural commodities, and their prevalence may increase due to global warming. According to the Food and Agriculture Organization of the United Nations, approximately 25% of the world's food crops are annually contaminated with mycotoxins. Mycotoxin-contaminated food and feed pose a high risk to both human and animal health. For instance, they possess carcinogenic, immunosuppressive, hepatotoxic, nephrotoxic, and neurotoxic effects. Hence, various approaches have been used to assess and control mycotoxin contamination. Significant challenges still exist because of the complex heterogeneous nature of food and feed composition. The potential of antigen-based approaches, such as enzyme-linked immunosorbent assay, flow injection immunoassay, chemiluminescence immunoassay, lateral flow immunoassay, and flow-through immunoassay, would contribute to our understanding about mycotoxins' rapid identification, their isolation, and the basic principles of the detection technologies. Additionally, we address other emerging technologies of potential application in the detection of mycotoxins. The data included in this review focus on basic principles and results of the detection technologies and would be useful as benchmark information for future research. © 2019 Society of Chemical Industry.


Subject(s)
Antigens/analysis , Food Contamination/analysis , Immunoassay/methods , Mycotoxins/analysis , Mycotoxins/immunology , Animal Feed/analysis , Animals , Enzyme-Linked Immunosorbent Assay/methods , Fiber Optic Technology/methods , Flow Injection Analysis/methods , Fluorescence Polarization Immunoassay/methods , Humans , Luminescent Measurements/methods , Optical Imaging/methods , Spectroscopy, Fourier Transform Infrared/methods , Spectroscopy, Near-Infrared/methods , Surface Plasmon Resonance/methods
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