Dual Functions of a Hybrid Magnetic Magnesium Oxide Nanocomposite as a Fungicide and Plant Growth Promoter in Agriculture Applications

The use of nanometal oxides in nanoagronomy has garnered considerable attention due to their excellent antifungal and plant growth promotion properties. Hybrid nanometal oxides, which combine the strengths of individual nanomaterials, have emerged as a promising class of materials. In this study, nanomagnesium oxide (n-MgO) and hybrid magnetic nanomagnesium oxide (m/n-MgO) were successfully synthesized via the ultrasound-mediated sol-gel method. Characterization results, including TGA, XRD, VSM, and FTIR, confirmed the successful synthesis of m/n-MgO. Both n-MgO and m/n-MgO underwent antifungal assays and plant growth promotion ability studies, benchmarked against the conventional fungicide-copper oxychloride. This study bridges a significant gap by simultaneously reporting the antifungal properties of both n-MgO and m/n-MgO and their impact on plant growth. The disc diffusion assay suggested that the antifungal activity of n-MgO and m/n-MgO against F. oxysporum was inversely related to the particle size. Notably, n-MgO exhibited superior antifungal performance (lower minimum inhibitory concentration (MIC)) and sustained efficacy compared with m/n-MgO, owing to distinct antifungal mechanisms. Nanorod-shaped MgO, with a smaller size (8.24 ± 5.61 nm) and higher aspect ratio, allowed them to penetrate the fungal cell wall and cause intercellular damage. In contrast, cubical m/n-MgO, with a larger size (20.95 ± 9.99 nm) and lower aspect ratio, accumulate on the fungal cell wall surface, disrupting the wall integrity, albeit less effectively against F. oxysporum. Moreover, in plant growth promotion studies, m/n-MgO-treated samples exhibited a 15.7% stronger promotion effect compared to n-MgO at their respective MICs. In addition, both n-MgO and m/n-MgO outperformed copper oxychloride in terms of antifungal and plant growth promoting activities. Thus, m/n-MgO presents a promising alternative to conventional copper-based fungicides, offering dual functionality as a fungicide and plant growth promoter, while the study also delves into the antifungal mechanisms at the intracellular level, enhancing its novelty.

A rapid HLA-DRB1*04 subtyping method using PCR and DNA heteroduplex generators

We describe here a rapid polymerase chain reaction (PCR)-based method for the identification of HLA-DRB1*0401-*0412 alleles. The method is based on the generation of specific DNA heteroduplex patterns between PCR products derived from selective group-specific amplification of the various DRB1*04 alleles and PCR products derived from two synthetic DNA heteroduplex generator (DHG) molecules following non-denaturing polyacrylamide minigel electrophoresis. One DHG was designed to detect DRB1*0401, *0405, *0407, *0408, and *0409 alleles, whilst the other was designed to detect DRB1*0402, *0403, *0404, *0406, *0410, *0411, and *0412 alleles. Characteristic heteroduplex patterns were obtained for all DRB1*04 alleles tested both in homozygous and heterozygous situations. Both DHG and PCR-SSP (sequence-specific primer) typing were performed on 41 DRB1*04 positive DNAs from Singaporean Chinese blood donors and complete concordance in results was obtained. HLA-DRB1*0403, *0405, and *0406 were found to account for 95% of the DRB1*04 alleles in the population studied. The DHG technique described is technically simple and rapid since it essentially involves only two PCR amplifications per individual subtyping. The technique is particularly useful for resolving DRB1*04 combinations which are indistinguishable by PCR-SSO (sequence-specific oligonucleotide) or PCR-SSP subtyping.

Immunotherapy of human cancers

Advances in molecular biology technologies have significantly facilitated the identification of functional genes which cause, promote or control a variety of human diseases. Through recombinant DNA and polymerase chain reaction technologies, individual genes responsible for specific diseases have been identified, and consequently, the prospect that these diseases might be "cured" through replacement of the defective genes by their normal counterparts become distinct possibilities. Therefore, the goal of gene therapy is to apply this technology to the treatment of human diseases. In addition to its logical role for the correction of inherited diseases caused by a missing or defective gene product, gene therapy also holds promise for treatment of acquired disorders such as human cancer through the introduction of genes whose products have been implicated in controlling the growth of cancer. In this report, we present our results on the introduction of allogeneic major histocompatibility complex genes into cancer cells as an approach to increase the host's immune response against cancer. Various gene delivery strategies have been optimized for the introduction of DNA into various human tumour cells and these data are presented.

A monoclonal-based IgM capture ELISA for detection of antibodies to 22 and 41 kDa membrane antigens of Toxoplasma gondii

A murine monoclonal antibody which reacts to 22 and 41 kDa Toxoplasma gondii surface antigens was employed in an IgM capture enzyme-linked immunosorbent assay (ELISA). A total of 125 patients' sera were tested in the monoclonal-based assay. When compared with a commercial ELISA test (Abbott Toxo-M EIA) which uses polyclonal anti-T. gondii antibodies, good correlation (Pearsons coefficient r = 0.91) was observed. The specificity of the assay was studied by testing a panel of control sera obtained from healthy individuals and blood transfusion donors; all sera gave negative results. Serum samples positive for T. gondii antibodies were treated with 2-mercaptoethanol (2-ME) to demonstrate the specificity of the test for IgM antibodies. Reactivity of these sera was lost after the treatment. The test is not subject to interference by rheumatoid factor as sera positive for rheumatoid factor were negative in the assay. Reproducibility was good with the coefficients of variation for within-day tests below 10% and not exceeding 18% for day-to-day tests. The monoclonal-based assay is simple to perform and appears to be a viable test for diagnosis of T. gondii infection.

The development and initial validation of a scale to measure social fear

Developed a true-false scale to measure Social Fear, which Meehl argues is a sign of schizotypy, using procedures to maximize reliability and minimize response set bias (N = 910). Interviews with selected Ss (N = 44) confirm that the scale measures social fear, and the scale was found to correlate with previously developed schizotypy scales (N = 252).