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Scintillation Detectors
Published in Michael Ljungberg, Handbook of Nuclear Medicine and Molecular Imaging for Physicists, 2022
The sensitivity of the photocathode as a function of wavelength is very important. Some scintillators have a very strong light emission but, if not matched with a suitable light sensor, the advantage of the scintillator is lost. A typical example is CsI(Tl), which often is described as yielding a lower pulse-amplitude per MeV than the corresponding NaI(Tl) when connected to a standard bialkali PM tube. The total photon emission from CsI(Tl) is, however, more abundant than the NaI(Tl) emission, but it has a proportionally larger part occurring in the red/infrared not energetic enough to produce photoelectrons. At higher wavelengths the energy of the photon is not enough to create and eject a photoelectron from the photocathode. At lower wavelengths, around 350 nm, the glass obstructs the light. In some cases, glass can be substituted with quartz which enables transmission even in the UV-region, which is important, for instance for Xe.
Polymer Materials for Oral and Craniofacial Tissue Engineering
Published in Vincenzo Guarino, Marco Antonio Alvarez-Pérez, Current Advances in Oral and Craniofacial Tissue Engineering, 2020
Iriczalli Cruz Maya, Vincenzo Guarino
Collagen-based materials, especially collagen type I, have been used extensively, for guided tissue and Guided Bone Regeneration (GTR/GBR) to separate the bone from epithelial and connective tissues during the regeneration process (Stoecklin-Wasmer et al. 2013). Collagen membranes have shown that the formation of bone and cementum improved on in vivo experiments (Tal et al. 1996). Nanofiber composites of fish collagen with bioactive glass and chitosan have been designed to promote bone regeneration in furcation defects on in vivo studies. Results have shown an excellent biocompatibility, meanwhile, the addition of bioactive glass improved the mechanical properties (Zhou et al. 2017). On the other hand, there are reports related with the antimicrobial activity of chitosan, therefore the addition of chitosan to these scaffolds may prevent the adhesion of bacteria by controlling the chitosan concentration without cytotoxic effects. Dense collagen gel scaffolds seeded with dental pulp stem cells have shown that it is a promising strategy for bone tissue regeneration on in vivo experiment by inducing osteogenic differentiation of MSCs (Chamieh et al. 2016).
The Working Rat Heart Preparation
Published in John H. McNeill, Measurement of Cardiac Function, 2020
A typical mounting assembly for a commercially available perfusion apparatus is shown diagrammatically in Figure 1A. Most often, the cannulas are made of stainless steel, although they can be hard plastic or glass. Steel is preferred because it is more rigid than plastic and more durable than glass. The steel should not be cleaned in acid, however, because of the risk of enhanced contamination of the perfusate with metal cations. It would also be helpful if the soldering connections were made with an inert element such as gold. Silver solder can be less durable than gold, and often contains copper, which can be cardiotoxic.
Diversity in matrilineages among the Jomon individuals of Japan
Published in Annals of Human Biology, 2023
Fuzuki Mizuno, Yasuhiro Taniguchi, Osamu Kondo, Michiko Hayashi, Kunihiko Kurosaki, Shintaroh Ueda
DNA was extracted from the bones, and the NGS library was constructed as described in our previous study (Mizuno et al. 2021). While performing DNA extraction, purification, and NGS library construction, all possible precautions were taken to avoid contamination. Experiments were performed in a laboratory that was exclusively dedicated to ancient DNA research and physically isolated from other molecular research laboratories. All experiments were performed in a laminar flow cabinet that was routinely irradiated with UV light. Frequent surface cleaning was routinely performed before and after the experiments. Facemasks, head caps, and clean laboratory coats were always worn, and gloves were frequently replaced. All the procedures were performed using sterilised disposable tubes and filter pipette tips. All non-disposable glass and metallic materials were dry-heat sterilised at 160 °C for 2–4 h.
Beading as a therapeutic activity in Ghana
Published in World Federation of Occupational Therapists Bulletin, 2021
Peter O. Ndaa, Abdul Hafiz Kwakye, Samnatha Shann
The Sustainable Development Goals (SDGs) (UN, 2015) are interconnected and highlight the relationships between poverty, health, climate change and the environment. Considering everyone’s responsibility to help achieve the SDGs, recycling is a major way of ensuring more sustainable consumption and production patterns. According to WFOT (2018), it is important that occupational therapists help clients adapt to environmental damage and raise awareness between climate change and health, therefore, by using recycled materials, occupational therapists lead by example and encourage clients to use sustainability principles in their everyday lives. The recycled glass used for making beads allows for conversations about the environment, as well as enabling clients to engage therapeutically in meaningful, culturally relevant occupations.
Microneedle arrays for the treatment of chronic wounds
Published in Expert Opinion on Drug Delivery, 2020
Lindsay Barnum, Mohamadmahdi Samandari, Tannin A. Schmidt, Ali Tamayol
The selection of an MNA fabrication approach is primarily dependent on the material being used. Silicon was the first material used for the fabrication of microneedle structures during the advent of microfabrication technologies in 1990s [65]. Biocompatibility, high mechanical strength, material stability, and well-developed microfabrication strategies make silicon an attractive candidate for MNA production. Solid [66] and hollow [67] silicon MNAs are usually fabricated using various dry and wet etching methods (Figure 1a,b). Although these approaches offer a nano-scale resolution, they require clean-room facilities and multiple time-consuming fabrication steps, which renders their fabrication expensive and low throughput. Furthermore, the brittle nature of silicon-based structures makes them susceptible to fracture, leaving residuals in the skin and inducing an immune response. To overcome the limitations of complicated and expensive clean-room microfabrication, glass microneedles were implemented for transdermal drug delivery [68] (Figure 1c). Glass is cost-effective, chemically inert, and has high mechanical strength, though it is brittle. Fabrication of glass microneedles is based on micro-pulling of glass tubes. While this technique does not require the use of expensive tools, it is a low throughput process.