Helium ion microscope – secondary ion mass spectrometry for geological materials

The helium ion microscope (HIM) is a focussed ion beam instrument with unprecedented spatial resolution for secondary electron imaging but has traditionally lacked microanalytical capabilities. With the addition of the secondary ion mass spectrometry (SIMS) attachment, the capabilities of the instrument have expanded to microanalysis of isotopes from Li up to hundreds of atomic mass units, effectively opening up the analysis of all natural and geological systems. However, the instrument has thus far been underutilised by the geosciences community, due in no small part to a lack of a thorough understanding of the quantitative capabilities of the instrument. Li represents an ideal element for an exploration of the instrument as a tool for geological samples, due to its importance for economic geology and a green economy, and the difficult nature of observing Li with traditional microanalytical techniques. Also Li represents a “best-case” scenario for isotopic measurements. Here we present details of sample preparation, instrument sensitivity, theoretical, and measured detection limits for both elemental and isotopic analysis as well as practicalities for geological sample analyses of Li alongside a discussion of potential geological use cases of the HIM–SIMS instrument

Si表面での水素原子による吸着水素の引き抜きと脱離に関する動力学的研究

九州工業大学博士学位論文　学位記番号:工博甲第197号　学位授与年月日:平成15年3月25

Aloe Vera-Mediated Te Nanostructures: Highly Potent Antibacterial Agents and Moderated Anticancer Effects

Cancer and antimicrobial resistance to antibiotics are two of the most worrying healthcare concerns that humanity is facing nowadays. Some of the most promising solutions for these healthcare problems may come from nanomedicine. While the traditional synthesis of nanomaterials is often accompanied by drawbacks such as high cost or the production of toxic by-products, green nanotechnology has been presented as a suitable solution to overcome such challenges. In this work, an approach for the synthesis of tellurium (Te) nanostructures in aqueous media has been developed using aloe vera (AV) extracts as a unique reducing and capping agent. Te-based nanoparticles (AV-TeNPs), with sizes between 20 and 60 nm, were characterized in terms of physicochemical properties and tested for potential biomedical applications. A significant decay in bacterial growth after 24 h was achieved for both Methicillin-resistant Staphylococcus aureus and multidrug-resistant Escherichia coli at a relative low concentration of 5 µg/mL, while there was no cytotoxicity towards human dermal fibroblasts after 3 days of treatment. AV-TeNPs also showed anticancer properties up to 72 h within a range of concentrations between 5 and 100 µg/mL. Consequently, here, we present a novel and green approach to produce Te-based nanostructures with potential biomedical applications, especially for antibacterial and anticancer applications.This work was supported by the Chemical Engineering Department at Northeastern University. M.K., L.D.G., and G.G. would like to thank the Center for Integrative Nanotechnology Sciences (CINS) of UA Little Rock for the use of their T.E.M. J.L. C.-D. thanks the School of Engineering and Sciences at Tecnológico de Monterrey through the Research Group on Photonics and Quantum Systems for financial support. A.D.J. was supported by the Northeastern Future Faculty Fellowship. L.M. acknowledges the European Union (grant number ERC-2013-SyG 610256 NANOCOSMOS) and Comunidad de Madrid (S2018/NMT-4367 FotoArt-CM). The groups at CSIC and Tecnológico de Monterrey acknowledge the i-Link+2019 program (ref. LINKB20024 “NANOBIO-ROJA”) for financial support. The authors also acknowledge the service from the MiNa Laboratory at IMN funded by Comunidad de Madrid (S2018/NMT-4291 TEC2SPACE), MINECO (CSIC13-4E-1794), and the EU (FEDER, FSE).Peer reviewe