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We fabricated a micron-sized biodevice based on the near-infrared photoluminescence (PL) response of single-walled carbon nanotubes (SWNTs). Various biosensors using the unique optical responses of SWNTs have been proposed by many research groups. Most of these employed either colloidal suspensions of dispersed SWNTs or SWNT films on flat surfaces, such as electrodes. In this study, we attached DNA-wrapped SWNTs (DNA-SWNTs) to frustule (micron-sized nanoporous biosilica) surfaces, which were purified from cultured isolated diatoms. After the injection of an oxidant and a reductant, the SWNTs on the frustules showed prominent PL responses. This suggests that the biodevice functions as a micron-sized redox sensor. Frustules can be easily suspended in aqueous solutions because of their porous structures and can easily be collected as pellets by low-speed centrifugation. Thus, the removal of unbound SWNTs and the recovery of the fabricated DNA-SWNT frustules for reuse were achieved by gentle centrifugation. Our proposal for micron-sized SWNT biodevices would be helpful for various biological applications.

Herein, we propose a convenient method to enable pretreatment of target objects using digital holographic microscopy (DHM). As a test sample, we used diatom frustules (Nitzschia sp.) as the target objects. In the generally used sample preparation method, the frustule suspension is added dropwise onto a glass substrate or into a glass chamber. While our work confirms good observation of purified frustules using the typical sample preparation method, we also demonstrate a new procedure to observe unseparated structures of frustules prepared by baking them on a mica surface. The baked frustules on the mica surface were transferred to a glass chamber with 1% sodium dodecyl sulfate solution. In this manner, the unseparated structures of the diatom frustules were clearly observed. Furthermore, metal-coated frustules prepared by sputtering onto them on a mica surface were also clearly observed using the same procedure. Our method can be applied for the observation of any target object that is pretreated on a solid surface. We expect our proposed method to be a basis for establishing DHM techniques for microscopic observations of biomaterials.

Research and synthesis of photosensitive purpurin 18 (Pp-18) from nature is one of the topics that many research groups are interested in and developing. In this study, the authors defined some characteristics of Pp-18 synthesised from chlorophyll a - a substance isolated from Spirulina. The results showed that Pp-18 had good dispersion in acetone at 478.5 nm (R2=0.98285) and reached 98%. Fluorescence spectroscopy of Pp-18 in acetone was measured at a concentration of 70 ppm, wavelengths 365.39, 417.62, and 557.96 nm. The fluorescence lifetime of Pp-18 in acetone solution was 2.85 ns.

The residential building sector regularly satisfies a diverse range of housing needs whilst addressing respective capital-cost considerations. Designers and builders must also be aware of the environmental implications of their design specifications; the work here adds to a body of knowledge concerned with carbon footprint and embodied energy demand, specifically through an examination of alternative roof-covering materials. A life cycle assessment (LCA) has been carried out, within a West Australian context, to compare impacts for the roof specification options of: clay tile; concrete tile; and sheet metal. In locations where recycling facilities are unavailable and thus disregarded, it is found that clay tiles have the lowest carbon footprint of 4.4 t of CO2 equivalent (CO2e-) and embodied energy demand of 52.7 Mega Joule (MJ) per 100 m2, while sheet-metal roofing has the highest carbon footprint (9.85 t of CO2e-), with concrete roof tiles having the highest embodied energy demand (83 MJ). Findings confirm that a sheet-metal roof can obtain significant carbon and embodied energy saving benefits (i.e. 71–73%) compared to clay tile or concrete roof covers through ongoing encouragement of recycling strategies and increased local recycling facilities able to embrace residual cradle-to-cradle material reuse.

Three-dimensional (3D) in vitro tissue or organ models can effectively mimic the complex microenvironment of many types of human tissues for medical applications. Unfortunately, development of 3D cancer models, which involve cancer/stromal cells in a 3D environment, has remained elusive due to the extreme complexity of the tumor microenvironment (TME) and the stepwise progression of human cancer. Here, we developed hepatocellular carcinoma (HCC) models, which consist of fibroblasts as stromal cells, HCC cells, and a nanofibrous membrane to mimic the complex TME. The 3D HCC models were fabricated using three distinct culture methods: cancer cells grown directly on the nanofibrous membrane (mono model), fibroblasts covering the nanofibrous membrane (layer model), and both cancer cells and fibroblasts grown on the nanofibrous membrane (mixed model). Interestingly, the mono model and layer model showed similar tissue structures, whereas the mixed model resulted in phenotypic changes to the cancer cells. Further analysis demonstrated that the mixed models promoted the expression of fibronectin and vimentin, and showed higher resistance to anticancer drugs compared with the other models. Thus, our 3D HCC model could be utilized for testing efficient anticancer therapies at various stages of cancer, with potential application to different tumor types.