Advances in Chemical Research

10.21926/acr. ◽  
2020 ◽  
Keyword(s):  
Chemical Research

Unpacking the Bead: Exploring a Glass Bead Assemblage from Mission Santa Cruz, California, Using LA–ICP–MS

2021 ◽  
Vol 86 (2) ◽  
pp. 413-424
Author(s):  
Danielle L. Dadiego ◽  
Alyssa Gelinas ◽  
Tsim D. Schneider
Keyword(s):  
Inductively Coupled Plasma ◽  
Southeastern United States ◽  
Glass Beads ◽  
Great Lakes Region ◽  
Santa Cruz ◽  
Chemical Research ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
California Mission

This report focuses on the morphometric and elemental analysis of glass beads collected from an adobe structure (CA-SCR-217H-T) at Mission Santa Cruz, which operated between 1791 and the 1830s in the colonial province of Alta (upper) California. Previous chemical research established a chronological framework for opacified beads collected from sites in Canada, the Great Lakes region, and the southeastern United States. Testing the viability of this chronological framework for California, we analyzed 100 white glass beads using a conventional typology and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS)—the first application of LA-ICP-MS to a California mission. We present the results of the LA-ICP-MS study and then briefly comment on the potential for LA-ICP-MS to refine chronologies associated with colonial missions and other postcontact sites.

scholarly journals Subtle structural alterations in G-quadruplex DNA regulate site specificity of fluorescence light-up probes

2020 ◽  
Vol 48 (3) ◽  
pp. 1108-1119 ◽  
Author(s):  
Rajendra Kumar ◽  
Karam Chand ◽  
Sudipta Bhowmik ◽  
Rabindra Nath Das ◽  
Snehasish Bhattacharjee ◽  
...  
Keyword(s):  
Rational Design ◽  
Dna Structure ◽  
Biological Processes ◽  
Chemical Research ◽  
Quadruplex Dna ◽  
Dna Structures ◽  
Future Studies ◽  
G4 Dna ◽  
G Quadruplex ◽  
Fluorescence Light

Abstract G-quadruplex (G4) DNA structures are linked to key biological processes and human diseases. Small molecules that target specific G4 DNA structures and signal their presence would therefore be of great value as chemical research tools with potential to further advance towards diagnostic and therapeutic developments. However, the development of these types of specific compounds remain as a great challenge. In here, we have developed a compound with ability to specifically signal a certain c-MYC G4 DNA structure through a fluorescence light-up mechanism. Despite the compound's two binding sites on the G4 DNA structure, only one of them result in the fluorescence light-up effect. This G-tetrad selectivity proved to originate from a difference in flexibility that affected the binding affinity and tilt the compound out of the planar conformation required for the fluorescence light-up mechanism. The intertwined relation between the presented factors is likely the reason for the lack of examples using rational design to develop compounds with turn-on emission that specifically target certain G4 DNA structures. However, this study shows that it is indeed possible to develop such compounds and present insights into the molecular details of specific G4 DNA recognition and signaling to advance future studies of G4 biology.

Design of a New 45 kWe High-Flux Solar Simulator for High-Temperature Solar Thermal and Thermo-Chemical Research

2010 ◽  
Author(s):  
Katherine R. Krueger ◽  
Jane H. Davidson ◽  
Wojciech Lipin´ski
Keyword(s):  
High Temperature ◽  
Focal Plane ◽  
Flux Distribution ◽  
Solar Thermal ◽  
Optimized Design ◽  
High Flux ◽  
Chemical Research ◽  
Solar Simulator ◽  
Peak Flux ◽  
The Common

In this paper, we present a systematic procedure to design a solar simulator for high-temperature concentrated solar thermal and thermo-chemical research. The 45 kWe simulator consists of seven identical radiation units of common focus, each comprised of a 6.5 kWe xenon arc lamp close-coupled to a precision reflector in the shape of a truncated ellipsoid. The size and shape of each reflector is optimized by a Monte Carlo ray tracing analysis to achieve multiple design objectives, including high transfer efficiency of radiation from the lamps to the common focal plane and desired flux distribution. Based on the numerical results, the final optimized design will deliver 7.5 kW over a 6-cm diameter circular disc located in the focal plane, with a peak flux approaching 3.7 MW/m2.

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