In recent times, the demand for innovative, insignificantly invasive diagnostic and therapeutic biomedical tools has reached enhanced attention. Rapid Diagnostic Tests (RDTs) for diagnosis, which are non-invasive, inexpensive, simple, and deliver results accurately in less than 20 minutes, have heightened the accessibility to parasite-based analysis globally. Microneedle (MN) arrays are a fast-developing and promising technology for drug delivery and extraction of Interstitial fluid (ISF) employed for numerous diagnostic and clinical therapies. This review gives a broad overview of the characteristics and history of Microneedles (MNs) patches together with their applications in drug delivery and transdermal rapid diagnostic purposes, classifications, and categories based on the design of fabrication from previous works of literature spanning the period 2018-2023. Utilizing PubMed, Scopus, Google Scholar, and Wiley online library search engines, an online search for scientific publications published between 2018 and 2023 was conducted using the keywords "microneedle patch" and "rapid diagnostic tests." 175 articles in all were found when the search terms were used. The acquired results were then narrowed to 64 citations in this review by applying the inclusion principle. Pictorial and tabular representations highlight the various features of Microneedle patches used in interstitial fluid testing and extraction that have been documented experimentally, including numerous applications of Microneedle patches, showing their dimensions, applications, fabrication methods, and findings made. Finally, research on bio-microneedles and bio-inspired MN are reviewed. The research findings indicate that dissolving microneedles has become increasingly popular since they have several benefits over other microneedles. It is among the most well-known microneedles, and since it degrades naturally, it is a superior option for diagnosis and long-term treatment.

This work investigates the hydrothermal synthesis and characterization of zeolite-4A from kaolin found in Ajebo, Nigeria calcined at 700 and 900 degrees C respectively. The synthesized zeolite-4A was further characterised using X-ray Fluorescence (XRF), Fourier Transform Infrared spectrometer (FTIR), Scanning Electron Microscopy (SEM), X-Ray diffraction (XRD), Brunauer-Emmet-Teller (BET) surface area analysis as well as Differential Thermal Analysis/Thermo-gravimetric (TG). Water adsorption capacity tests were also carried out on the synthesized zeolite-4A. The results from the XRF measurements indicated that the amount of Al2O3 and SiO2 in the studied kaolin was similar to the standard kaolin composition making it a perfect candidate for zeolite-4A synthesis. FTIR showed the characteristic zeolite peaks while XRD confirmed the crystalline nature of the synthesized zeolite-4A. TG studies showed that the zeolite-4A samples were stable up to temperatures of 700 degrees C. This stability as well as the surface area and pore size of 7 A makes it potentially suitable for use in water treatment applications. The SEM showed cubic crystals which were typical of the morphology of zeolite-4A with water adsorption capacity of approximately 29%. These results indicate that zeolite-4A can be synthesized from kaolin found in Ajebo as an inexpensive alternative to traditionally sourced materials and also is suitable for use as adsorption agent.

Kaolin samples from Ajebo and Darazo in Nigeria were characterized and used to produce zeolite - A crystals. The thermal analysis indicates that both samples under gode-hydroxylation from 450oC to about 700oC and are converted to metakaolin with a weight lo ss of about 11.39 and 10.43% for the Ajebo and Darazo samples respectively. Characteristic OH, Al-OH, Si-OH and Si-O-Albands were confirmed in both samples with Infra-red spectroscopy studies. The X - ray diffraction patterns clearly show the presence of the characteristic peaks (12.35 and 24.88o ) of kaolinite with little quartz impurities. X - ray diffraction measurements (2Ɵ peaks at 7 – 18o and 21 – 35o ) and scanning electron micro graphs clearly show that zeolite - A crystals are produced. The microstructures of kaolin, metakaolin and zeolite - A crystals reveal the presence of platy crystals, amorphous spherical aggregates and cubic - shaped crystals with some amorphous gel respectively . The results show that both Ajebo and Darazo kaolin are suitable for zeolite - A synthesis. Keywords: Kaolin, Metakaolin, Thermal analysis, X - ray Diffraction, Zeolite - A

In the current study, the influence of delta (delta) ferrite on the corrosion susceptibility of AISI 304 austenitic stainless steel was evaluated in 1Molar concentration of sulphuric acid (H2SO4) and 1Molar concentration of sodium chloride (NaCl). The study was performed at ambient temperature using electrochemical technique-Tafel plots to evaluate the corrosive tendencies of the austenitic stainless steel sample. The as-received (stainless steel) specimen and 60% cold-worked (stainless steel) specimens were isothermally annealed at 1,100 degrees C for 2 h and 1 h, respectively, and quenched in water. The results obtained show that the heat-treated specimen and the 60% cold-worked plus heat-treated specimen exhibited higher corrosion susceptibility than the as-received specimen, which invariably contained the highest fraction of delta ferrite particles. The finding shows that the presence of delta ferrite, in which chromium (Cr), the main corrosion inhibitor segregates, does not degrade and or reduces the resistance to aqueous corrosion of the austenitic stainless steel material.