The high cost of using the niobium (Nb) barrier for manufacturing magnesium diboride (MgB₂) mono-and multi-filamentary wires for large-scale applications has become one of the barriers to replacing current commercial niobium-titanium superconductors. The potential of replacing the Nb barrier with a low-cost iron (Fe) barrier for multifilament MgB₂ superconducting wires is investigated in this manuscript. Therefore, MgB₂ wires with Fe barrier sintered with different temperatures are studied (from 650 ℃ to 900 ℃ for 1 h) to investigate the non-superconducting reaction phase of Fe-B. Their superconducting performance including engineering critical current density (J_e) and n-value are tested at 4.2 K in various external magnetic fields. The best sample sintered at 650 ℃ for 1 h has achieved a J_e value of 3.64 × 10⁴ A cm⁻² and an n-value of 61 in 2 T magnetic field due to the reduced formation of Fe₂B, better grain connectivity and homogenous microstructure. For microstructural analysis, the focused ion beam (FIB) is utilised for the first time to acquire three-dimensional microstructures and elemental mappings of the interface between the Fe barrier and MgB₂ core of different wires. The results have shown that if the sintering temperature can be controlled properly, the J_e and n-value of the wire are still acceptable for magnet applications. The formation of Fe₂B is identified along the edge of MgB₂, as the temperature increases, the content of Fe₂B also increases which causes the degradation in the performance of wires.

Sweat contains numerous vital biomarkers such as metabolites, electrolytes, proteins, nucleic acids and antigens that reflect hydration status, exhaustion, nutrition, and physiological changes. Conventional healthcare diagnosis relies on disease diagnostics in sophisticated centralized laboratories with invasive sample collection (e.g., chemical analyses, plasma separation via centrifugation, tissue biopsy, etc.). Cutting-edge point-of-care diagnostics for sweat biomarker analysis allow for non-invasive monitoring of physiologically related biomarkers in sweat and real-time health status tracking. Moreover, using advanced nanoarchitectures, including nanostructured platforms and nanoparticles, can enhance the specificity, sensitivity, wearability and widen the sensing modality of sweat biosensors. Herein, we comprehensively review the secretory mechanisms, clinical uses of sweat biomarkers, and the design, principle, and latest technologies of sweat biosensors. With an emphasis on cutting-edge technologies for sweat biomarker analysis, this review chronicles the issues associated with the current sweat biomarkers analysis of sweat biomarkers and provides insights into strategies for enhancing the translation of such biosensors into routine clinical practice.

Magnesium diboride (MgB₂) magnets have the potential to be the next-generation liquid-helium-free magnet for magnetic resonance imaging (MRI) application due to their relatively high superconducting transition temperature, high current density and low raw material cost compared with current commercial niobium-titanium (Nb-Ti) magnets. A typical superconducting magnet includes several coils. To produce an ultra-stable magnetic field for imaging in MRI, a superconducting electromagnet operating in a persistent mode is crucial. Superconducting coils of the electromagnet in MRI are short-circuited to operate in the persistent mode by connecting coils with superconducting joints. Persistent joints have been demonstrated for in-situ and ex-situ wires of both mono- and multi-filamentary structures, made predominantly by PIT techniques similar to those used in wire production. To realise further engagement of MgB₂ in MRI applications, enhancing the performance of MgB₂ superconducting joints is essential. This literature review summarises research and development on MgB₂ superconducting joining technology.