Search

This paper reports a high-resolution isotopic study of medieval horse mobility, revealing their origins and in-life mobility both regionally and internationally. The animals were found in an unusual horse cemetery site found within the City of Westminster, London, England. Enamel strontium, oxygen, and carbon isotope analysis of 15 individuals provides information about likely place of birth, diet, and mobility during the first approximately 5 years of life. Results show that at least seven horses originated outside of Britain in relatively cold climates, potentially in Scandinavia or the Western Alps. Ancient DNA sexing data indicate no consistent sex-specific mobility patterning, although three of the five females came from exceptionally highly radiogenic regions. Another female with low mobility is suggested to be a sedentary broodmare. Our results provide direct and unprecedented evidence for a variety of horse movement and trading practices in the Middle Ages and highlight the importance of international trade in securing high-quality horses for medieval London elites.

We report on a simple, rapid, and room-temperature undergraduate-level experiment for gold nanoparticle synthesis, analysis, and utilization as a catalyst for the sodium-borohydride-assisted reduction of methylene blue and Congo red dyes. Typical procedures toward gold nanoparticle formation require an elaborate, lengthy synthesis (some requiring 1 h for completion of nanoparticle formation and ripening), whereas faster methods frequently yield inhomogeneous or catalytically inferior gold nanoparticles. This situation limits the usefulness of gold nanoparticles as rudimentary nanochemistry teaching tools in time-restricted undergraduate laboratories. The rapid gold nanoparticle synthesis presented herein utilizes ascorbic acid or sodium borohydride as dual reducing/capping agents to produce catalytically active gold nanoparticles at the "speed of mixing" under ambient conditions, allowing preparation and characterization to be performed within a single laboratory period. Furthermore, whereas most gold nanoparticle syntheses require rigorously cleaned glassware to avoid contamination and irreproducibility, the devised undergraduate experiment reported here alleviates this burden by employing disposable reaction vessels. Thus, this undergraduate-level laboratory experiment is designed to provide a meaningful introduction to metal nanoparticle synthesis and application while simultaneously being accommodated by a typical 2-4 h laboratory period, providing much-needed teaching assistance in the growing field of nanomaterials education.

A wide range of analytical strategies and approaches have been developed, accomplishing significant advances in searching for efficient, fast, reliable, sensitive, and accurate protocols for sample analysis in recent decades. Chemical sensors are also low-cost, portable, and ecologically friendly, making them a preferred method of choice for a broad spectrum of sample analysis in various matrices of complexity. Of particular interest are sensors based on fluorescent molecules, nanoparticles, nanoclusters, quantum dots, carbon nanotubes, molecularly imprinted polymers, sol-gels, dyes, porphyrins, ionic liquids, organized media, and fluorescent sensor arrays in microfluidic chips. This review highlights and provides concise and in-depth coverage of recent innovations, challenges, advances, and applications of a variety of fluorescence-based sensors for sample analysis between 2018 and 2022. Emphasis is placed on instrumentation design and the applications of sensors in analytical, environmental, pharmaceutical, agricultural, food, and forensic sample analysis. Recent innovations and the practical utility of fluorescent chemical sensors relevant to biological systems, biomedical sample measurements, and clinical diagnosis are extensively reviewed. Future directions and trajectories of fluorescent chemical sensors for various utilities, applications, and sample measurements are highlighted and discussed. [ABSTRACT FROM AUTHOR]

We report on a two-dimensional hexagonal "honeycomb" network comprising barium-seamed metal–organic nanocapsules involving a hexameric assembly of pyrogallol[4]arene ligands. The incorporated barium ions act as spacers to generate a solvent-accessible void, hierarchical self-assembly having an individual void volume near 13 000 Å3. This work illustrates the surprising chemistry that remains to be discovered by integrating large or classically non-reactive metal ions within supramolecular assemblies, networks, and organic nanocapsules. [ABSTRACT FROM AUTHOR]

As a low-rank coal, lignite (brown coal) is usually well treated by chemical or enzymatic methods prior to its utilization for energy and materials. Following ionic liquids (ILs)-pretreatment, this study focuses on the treatment of lignite by oxidoreductase-type of enzymes including horseradish peroxidase (HRP), alcohol dehydrogenase (ADH), and laccase. We observed some synergistic effects of IL-pretreatment and enzymatic actions on lignite coal. The combination of IL-pretreatment and HRP-/ADH-treatment enabled smaller and more uniform coal particles than IL-pretreatment alone or that without HRP. However, laccase-treatment led to large coal aggregates likely due to the crosslinking effect. Both HRP- and ADH-treatments induced a lower aliphatic and a higher aromatic content of lignite, particularly when the coal was pretreated by an IL prior to the enzymatic process. Both ADH- and laccase-treatments produced more hydrogen bonds in the coal. Therefore, the combined treatments of lignite by ILs and oxidoreductases dedicate low-rank coal structures. [ABSTRACT FROM AUTHOR]