Magnetic Control of Biogenic Micro-Mirror
Shoogo Ueno in Bioimaging, 2020
Optical fiber-based measurement systems were used with the superconducting magnet or the electromagnet, depending on the magnetic field intensity required. In the magnetic field region were an optical quartz sample cell, mirrors (if necessary), and optical fibers from a light source and to a cooled CCD spectrophotometer. The magnetic field, incident light, and observation directions had three different modes (MODE-I, II, III) for the evaluation of light scattering anisotropies of the micro-crystals in an aqueous solution, as depicted in Figure 10.2(b). Micro-crystals of cellulose and hexagonal boron nitride (h-BN) were prepared from powder products (Ceolus, from pulp Type-Iβ cellulose, Asahi Kasei co. Ltd., Japan, and boron nitride powder GP, DENKA co Ltd., Japan).
Benign Melanocytic Lesions
Ashfaq A Marghoob, Ralph Braun, Natalia Jaimes in Atlas of Dermoscopy, 2023
The most characteristic pattern of BN is the presence of homogeneous and structureless blue pigmentation. The pigment in BN is confluent throughout the lesion and fades toward the periphery (Figures 7d.2, 7d.3). Subtypes of BN may reveal a combination of two colors, including white-blue, steel-blue-gray, blue-brown, or blue-black. While multichromatic pigmentation can be seen in BN, they always include blue in the spectrum of colors being displayed (Figure 7d.4) (9). With the use of polarized light dermatoscopes, additional structures may be seen, including bluish globules/dots, shiny white lines, network-like structures, or peripheral out-of-focus streaks corresponding to pigmented projections of nevomelanocyte clusters or melanophages within the dermis. Lesions showing more criteria than the homogeneous structureless blue pigmentation should raise suspicion for melanoma, and in such lesions, the context and history will play a critical role in management decisions.
Bayesian Applications
Song S. Qian, Mark R. DuFour, Ibrahim Alameddine in Bayesian Applications in Environmental and Ecological Studies with R and Stan, 2023
A BN is made of nodes that take certain values or states and arrows connecting nodes. The arrows represent probability dependencies among the nodes. BNs allow for the seamless forward and backward propagation of information, especially when the data are discrete. Most BN applications opt for discretizing nodes into states, where each node is defined over a set of k non-overlapping states that are commonly referred to as intervals. As such, the probability to be in any given state is governed by a multinomial distribution (7.2) with probability vector θ given a number of trials n. Note that the length of the vector θ will be equal to the number of states defined minus 1.
Ecotoxicological assessment of commercial boron nitride nanotubes toward Xenopus laevis tadpoles and host-associated gut microbiota
Published in Nanotoxicology, 2021
Lauris Evariste, Emmanuel Flahaut, Clément Baratange, Maialen Barret, Florence Mouchet, Eric Pinelli, Anne Marie Galibert, Brigitte Soula, Laury Gauthier
Boron nitride nanotubes (BNNT) are nanoparticles structurally analogous to carbon nanotubes (CNTs) in which boron and nitrogen replace carbon atoms (Chopra et al. 1995). Increasing attention is being paid to these BNNT due to their unique properties such as high thermo-mechanical stability (Suryavanshi et al. 2004; Chen et al. 2004), electrical insulation (Radosavljević et al. 2003) and thermal conductivity (Chang et al. 2006). As high quality materials are increasingly available due to the improvement of synthesis techniques, BNNT are triggering great interest for the development of applications in a wide range of area such as composite improvement, medicine, hydrogen storage as well as aquatic pollution remediation (Kim et al. 2018; Kalay et al. 2015; Zhi et al. 2008; Merlo et al. 2018; Lale, Bernard, and Demirci 2018; Yu et al. 2018). Such keen interest for this material predicts a large-scale production in the near future. As any engineered nanomaterial, BNNT could be released into the environment during the whole material life cycle, from the production, the use and the waste disposal or recycling to reach significant levels in aquatic ecosystems (Yu et al. 2018; Mottier et al. 2017). For these reasons, this implies to evaluate its biocompatibility and its potential hazard for the environment before considering the mass use of this nanomaterial.
In vivo Toxicity Assessment of Silver Nanoparticles in Homeostatic versus Regenerating Planarians
Published in Nanotoxicology, 2019
Nathalie Leynen, Frank G.A.J Van Belleghem, Annelies Wouters, Hannelore Bove, Jan-Pieter Ploem, Elsy Thijssen, Sabine A.S. Langie, Robert Carleer, Marcel Ameloot, Tom Artois, Karen Smeets
In this study, we used the freshwater planarian Schmidtea mediterranea to study underlying mechanisms of nanoparticle toxicity on stem cells, regeneration and development in vivo. Planarians have gained interest as toxicological models for compounds such as carcinogens or neurotoxicants (Inden et al. 2004; Gentile, Cebrià, and Bartscherer 2011; Hagstrom et al. 2015; Stevens et al. 2017). They were established as a model for assessing nanotoxicity in studies on boron nitride NPs (Salvetti et al. 2015) and AgNPs (Kustov et al. 2014). Because of their large pool of pluripotent stem cells, planarians can regenerate any damaged or amputated tissue, including the entire nervous system, which makes them attractive organisms for (neuro-)developmental research (Hagstrom, Cochet-Escartin, and Collins 2016). In addition, as regeneration is induced by amputation, adults can be studied in parallel with genetically identical regenerating animals. We exposed the worms to uncoated (NC-AgNPs) and PVP-coated (PVP-AgNPs) spherical AgNPs with a nominal size of 20 nm (actual primary particle size: ±35 nm) to address changes in physicochemical parameters and toxic effects related to the addition of a coating. Homeostatic animals were compared to regenerating animals in order to specifically screen for stem cell-related and developmental effects. To ensure that our results were reproducible and meaningful, an important part of this study was devoted to the determination of the particle characteristics and cellular uptake. This enabled us to link variations in physicochemical parameters during AgNP exposure with the observed effects.
DNA breaks evaluation of two water-based metalworking fluids by an occupational exposure design
Published in Toxin Reviews, 2023
Zahra Moradpour, Parviz Abdolmaleki, Behnam Hajipour-Verdom, Ali Khavanin, Zahra Panjali, Nader Maghsudi, Mansoureh Hamidi, Rezvan Zendehdel
The biological activity of boron-containing chemicals was reported in different studies (Soriano-Ursúa et al.2014, Bolt et al.2017). Identification of toxic effects of some boron components turned into therapeutic usage of these chemicals (Das et al.2013) as antiviral, antibacterial, anti-protest, antifungal, and anticancer usage (Scorei and Popa 2010, Yang et al.2018). However, some researchers believe boron toxicity strategies should be used for boron-containing chemicals application (Soriano-Ursúa et al.2019). In a study by Lenke Horvath et al. the effects of boron nitride were investigated on the viability and metabolic status of various cell types including lung alveolar cells and human embryonic kidney (HEK) cells. The results showed that boron nitride is cytotoxic for all cell types studied (Horvath et al.2011). However, toxic effects of boron component were confirmed by Canturk et al. study. They found that boron compounds in both lymphocytes and HL-60 cells decrease mitochondrial function and increase cell death (Canturk et al.2016). The results of our study show for MWFs used in the industrial process, comet parameters of fluid with boron component (Bb) occurred at a level lower than ethyl amine-containing fluid (Cb). These results were confirmed by significantly higher DNA damage in air samples of Ba type than Ca samples. It seems more investigations have to be studied for toxicity assessment of corrosion inhibitors in MWFs. However, based on our results careful design has been recommended for the usage of boron-containing MWFs. We suggest faster replacement of boron-containing MWFs in metal processing industries based on the chemical content of fluids. In summary, chemical production management has to be considered for the usage of MWFs in the industries. The risk of MWFs exposure in the workers’ health is the target of our study. Difference between the A549 cell line exposure and airborne exposure of the workers is the limitation of our study.
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