•The effect of sintering temperature on the properties of tungsten oxide pellet reported for the first time.•Sintering temperature has a significant impact on the structure, optical and the ...electrical properties.•The variations in the optical parameter values are reported.
Tungsten oxide (WO3) pellets were prepared using a hydraulic press and then sintered at temperatures between 900 and 1200 °C for 2 h. The as-prepared as well as the sintered pellets confirmed the presence of a single phase of WO3, having a monoclinic structure with increase in grain size and the variation in the morphology. The sintered density reached up to 97% of the theoretical value. The optical parameters and the I-V characteristics were found to be greatly dependent on the sintering temperature. This work delineates a strategy towards developing tungsten oxide pellets with enhanced properties especially focused on sensing applications.
Additive manufacturing has attracted increasing attention worldwide, especially in the healthcare, biomedical, aerospace, and construction industries. In Malaysia, insufficient acceptance of this ...technology by local industries has resulted in a call for government and local practitioners to promulgate the development of this technology for various industries, particularly for biomedical products. The current study intends to frame the challenges endured by biomedical industries who use 3D printing technology for their manufacturing processes. Qualitative methods, particularly in-depth interviews, were used to identify the challenges faced by manufacturing firms when producing 3D printed biomedical products. This work was able to identify twelve key challenges when deploying additive manufacturing in biomedical products and these include issues related to binder selection, poor mechanical properties, low-dimensional accuracy, high levels of powder agglomeration, nozzle size, distribution size, limited choice of materials, texture and colour, lifespan of materials, customization of fit and design, layer height, and, lastly, build-failure. Furthermore, there also are six challenges in the management of manufacturing biomedical products using 3D printing technology, and these include staff re-education, product pricing, limited guidelines, cyber-security issues, marketing, and patents and copyright. This study discusses the reality faced by 3D printing players when producing biomedical products in Malaysia, and presents a primary reference for practitioners in other developing countries.
Business; Biomedical products; Additive manufacturing; 3D printing technology
Background. Several studies in the last decades have focused on finding a precise method for the diagnosis of periodontal disease in its early stages. Aim. To evaluate from current scientific ...literature the most common and precise method for gingival crevicular fluid (GCF) sample collection, biomarker analytical methods, and the variability of biomarker quantification, even when using the same analytical technique. Methodology. An electronic search was conducted on in vivo studies that presented clinical data on techniques used for GCF collection and biomarker analysis. Results. The results showed that 71.1%, 24.7%, and 4.1% of the studies used absorption, microcapillary, and washing techniques, respectively, in their gingival crevicular fluid collection. 73.1% of the researchers analyzed their samples by using enzyme-linked immunosorbent assay (ELISA). 22.6%, 19.5%, and 18.5% of the researchers included interleukin-1 beta (IL-1β), matrix metalloproteinase-8 (MMP-8), and tumor necrosis factor-alpha (TNF-α), respectively, in their studies as biomarkers for periodontal disease. Conclusion. IL-1β can be considered among the most common biomarkers that give precise results and can be used as an indicator of periodontal disease progression. Furthermore, paper strips are the most convenient and accurate method for gingival crevicular fluid collection, while enzyme-linked immunosorbent assay can be considered the most conventional method for the diagnosis of biofluids.
Difficulties with the integration of
CO
2
and Nd-YAG lasers into a machining centre have hitherto impeded industrial implementation of laser assisted machining technologies. The rapidly emerging new ...technology of high-power diode lasers holds potential in this regard, on account of the laser being compact and the feasibility of fiber optic beam transport. In comparison to other commercial systems, high-power diode lasers combine higher efficiency and metal absorption with lower capital and operating costs; however, their current metal processing applications are confined largely to surface hardening and joining, due to their lower power density. With a view to expanding their application envelope, the work presented in this paper explores high-power diode laser assisted turning of fully hardened AISI D2 tool steel, a material that is difficult to machine. Laser assist is shown to inhibit saw tooth chip formation, suppress chatter, deter catastrophic tool fracture and bring about a substantial reduction in tool wear and cutting forces, with minimal affect on the integrity of the machined surface.
The effectiveness of stem cell therapies has been hampered by cell death and limited control over fate. These problems can be partially circumvented by using macroporous biomaterials that improve the ...survival of transplanted stem cells and provide molecular cues to direct cell phenotype. Stem cell behaviour can also be controlled in vitro by manipulating the elasticity of both porous and non-porous materials, yet translation to therapeutic processes in vivo remains elusive. Here, by developing injectable, void-forming hydrogels that decouple pore formation from elasticity, we show that mesenchymal stem cell (MSC) osteogenesis in vitro, and cell deployment in vitro and in vivo, can be controlled by modifying, respectively, the hydrogel's elastic modulus or its chemistry. When the hydrogels were used to transplant MSCs, the hydrogel's elasticity regulated bone regeneration, with optimal bone formation at 60 kPa. Our findings show that biophysical cues can be harnessed to direct therapeutic stem cell behaviours in situ.
Toxoplasma gondii, a common brain-tropic parasite, is capable of infecting most nucleated cells, including astrocytes and neurons, in vitro. Yet, in vivo, Toxoplasma is primarily found in neurons. In ...vitro data showing that interferon-γ-stimulated astrocytes, but not neurons, clear intracellular parasites suggest that neurons alone are persistently infected in vivo because they lack the ability to clear intracellular parasites. Here we test this theory by using a novel Toxoplasma-mouse model capable of marking and tracking host cells that directly interact with parasites, even if the interaction is transient. Remarkably, we find that Toxoplasma shows a strong predilection for interacting with neurons throughout CNS infection. This predilection remains in the setting of IFN-γ depletion; infection with parasites resistant to the major mechanism by which murine astrocytes clear parasites; or when directly injecting parasites into the brain. These findings, in combination with prior work, strongly suggest that neurons are not incidentally infected, but rather they are Toxoplasma's primary in vivo target.
•Highly oriented ZnO nanorods were grown on glass by thermal evaporation.•Superparamagnetism is observed in undoped ZnO nanorods.•Electrical conductivity measurement showed hopping of charge ...carriers.•Undoped ZnO nanorods can be used for drug delivery and MR imaging.
Nanostructured zinc oxide nanorods were prepared by the oxidation of nanostructured zinc films by thermal evaporation of metallic zinc. XPS measurement showed that the peak intensity of adsorbed oxygen is comparatively higher compared to intrinsic oxygen vacancies. The electrical conductivity measurements showed that the conduction mechanism in ZnO nanorods is due to the hopping of charge carriers. Magnetic measurements showed neither hysteresis nor remanence indicating superparamagnetism in the samples. The hopping of charge carriers and superparamagnetism in undoped ZnO is attributed to presence of adsorbed oxygen gas molecules in the surface.
PDF
