Human brucellosis: Six years retrospective study on seropositivity in Malaysia.

INTRODUCTION: Human brucellosis is a zoonotic disease in Malaysia. This study analysed six-year retrospective seropositivity trends of human brucellosis cases from 2014 to 2019. METHODS AND MATERIALS: A total of 1,281 serum samples were obtained from suspected brucellosis patients were included. The sera were tested using an enzyme-linked immunosorbent assay for IgM and IgG antibodies for Brucella spp. Samples with equivocal or positive antibody index were confirmed with an immunocapture agglutination. RESULTS: During the study period, 5.8% (n=74) of suspected cases showed seropositivity for human brucellosis. The central region has the highest seropositivity cases of human brucellosis. Consumption of unpasteurised milk was significantly associated with human brucellosis in this study with adjusted odds ratio ((AOR) = 4.56, 95% CI = 2.6, 8.02, p-value < 0.001). The age group of less than 15 years old was more likely to contract brucellosis ((AOR) = 2.81, 95% CI = 1.01, 7.84 p-value < 0.048). CONCLUSION: Serological tests have been widely used for the diagnosis of human brucellosis. However, diagnosis using serology is often challenging without the presence of a convalescent sample. In conclusion, even though human brucellosis has a low prevalence rate, the disease has serious public health implications. The usage of effective diagnostic tools as well as implementation of 'One Health' approach are the way forward to prevent and control of brucellosis in the country.

Reprocessed magnetorheological elastomers with reduced carbon footprint and their piezoresistive properties.

Despite the vast amount of studies based on magnetorheological elastomers (MREs), a very limited number of investigations have been initiated on their reprocessing. This paper presents a new type of recyclable MRE which is composed of thermoplastic polyurethane (TPU) and carbonyl iron particles (CI). The chosen TPU can be processed using injection moulding (IM), followed by several reprocessing cycles while preserving its properties. Numerous types of injection moulded and reprocessed MREs have been prepared for various particle concentrations. The effect of thermo-mechanical degradation on the recycled MREs has been investigated while simulating the reprocessing procedure. An apparent decrease in molecular weight was observed for all the examined matrices during the reprocessing cycles. These changes are attributed to the intermolecular bonding between the hydroxyl groups on the surface of the CI particles and the matrix which is studied in depth. The effect of reprocessing and the presence of magnetic particles is evaluated via tensile test, magnetorheology and piezoresistivity. These characterization techniques prove that the properties of our MREs are preserved at an acceptable level despite using 100% of recyclates while in real applications only up to 30% of recycled material is generally used.

A comparative work on the magnetic field-dependent properties of plate-like and spherical iron particle-based magnetorheological grease.

In this study, a new magnetorheological (MR) grease was made featuring plate-like carbonyl iron (CI) particles, and its magnetic field-dependent rheological properties were experimentally characterized. The plate-like CI particles were prepared through high-energy ball milling of spherical CI particles. Then, three different ratios of the CI particles in the MR grease, varying from 30 to 70 wt% were mixed by dispersing the plate-like CI particles into the grease medium with a mechanical stirrer. The magnetic field-dependent rheological properties of the plate-like CI particle-based MR grease were then investigated using a rheometer by changing the magnetic field intensity from 0 to 0.7 T at room temperature. The measurement was undertaken at two different modes, namely, a continuous shear mode and oscillation mode. It was shown that both the apparent viscosity and storage modulus of the MR grease were heavily dependent on the magnetic field intensity as well as the CI particle fraction. In addition, the differences in the yield stress and the MR effect between the proposed MR grease featuring the plate-like CI particles and the existing MR grease with the spherical CI particles were investigated and discussed in detail.