Search for: All records

Barley stripe mosaic virus (BSMV) is a promising biotemplate for the mineralization of metal–organic nanorods. Biomineralization of palladium occurs without an external reducing agent; however, the reduction of gold on wild-type BSMV requires a reducing agent. Recently, histidine has been adopted as a capping and reducing agent for the mineralization of gold nanoparticles. BSMV virus-like particles (BSMV-VLPs) tagged with histidine were investigated for direct gold deposition. However, gold nanoparticles were not formed during the mineralization process. Therefore, the aim of this research was to decorate gold nanoparticles onto palladium-coated BSMV (Pd-BSMV). The gold decoration was achieved through the addition of free histidine. X-ray absorption spectroscopy and energy-dispersive X-ray spectroscopy were used to verify the formation of metallic gold, and a kinetic study of the gold decoration process and the pH effect on the morphologies of gold particles was performed. The development of gold-decorated Pd-BSMV will be crucial for therapeutic applications, such as drug delivery, gene therapy, and photothermal therapy. 

ArticleSize-Controlled Synthesis of Rhodium Nanocatalysts and Applications in Low-Temperature HydroformylationAndrew Lamkins 1,2, Charles J. Ward 1,2, Jeffrey T. Miller 3, Ziad Alsudairy 4, Xinle Li 4, Joseph Thuma 1,2, Ruoyu Cui 1,2, Xun Wu 1,2, Levi M. Stanley 1 and Wenyu Huang 1,2,*1 Department of Chemistry, Iowa State University, Ames, IA 50010, USA2 Ames Laboratory, U.S. Department of Energy, Ames, IA 50010, USA3 Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47907, USA4 Department of Chemistry, Clark Atlanta University, Atlanta, GA 30314, USA* Correspondence: whuang@iastate.eduReceived: 3 December 2024; Revised: 30 December 2024; Accepted: 3 January 2025; Published: 10 January 2025 Abstract: Controlling the size and distribution of metal nanoparticles is one of the simplest methods of tuning the catalytic properties of a material. For a nanocrystal particle, the ratio of edge-to-terrace sites can be critical in determining its catalytic activity and selectivity to desired products. To study these effects, we have developed a simple impregnation method of controlling the dispersion of rhodium atoms at the same metal loading in the range of nanoparticles less than 10 nm. Rh precursor salts are loaded onto inert SBA-15, and increasing the ratio of chloride to acetylacetonate salts improves the dispersion of rhodium atoms to form small Rh nanoparticles. Extensive characterization of the size-controlled catalysts, including XAS and in-situ CO-DRIFTS studies, has been performed to characterize the structure of Rh nanoparticles. Applying these catalysts to the hydroformylation of styrene, we observed that turnover frequency increases with decreasing particle size from 6.4 to 1.6 nm. When applied to hydroformylation reactions, we achieved a high branched product selectivity and successfully demonstrated a route to synthesizing the pain relief drug ibuprofen. This simple method can also synthesize Pt and Pd nanoparticles between 2–10 nm. 

Abstract Loss-of-function alleles are a pertinent source of genetic variation with the potential to contribute to adaptation. Cave-adapted organisms exhibit striking loss of ancestral traits such as eyes and pigment, suggesting that loss-of-function alleles may play an outsized role in these systems. Here, we leverage 141 whole genome sequences to evaluate the evolutionary history and adaptive potential of single nucleotide premature termination codons (PTCs) in Mexican tetra. We find that cave populations contain significantly more PTCs at high frequency than surface populations. We also find that PTCs occur more frequently in genes with inherent relaxed evolutionary constraint relative to the rest of the genome. Using SLiM to simulate PTC evolution in a cavefish population, we show that the smaller population size and increased genetic drift is sufficient to account for the observed increase in PTC frequency in cave populations without positive selection. Using CRISPR-Cas9, we show that mutation of one of these genes, pde6c, produces phenotypes in surface Mexican tetra that mimic cave-derived traits. Finally, we identify a small subset of candidate genes that contain high-frequency PTCs in cave populations, occur within selective sweeps, and may contribute to beneficial traits such as reduced energy expenditure, suggesting that a handful of PTCs may be adaptive. Overall, our work provides a rare characterization of PTCs across wild populations and finds that they may have an important role in loss-of-function phenotypes, contributing to a growing body of literature showing genome evolution through relaxed constraint in subterranean organisms. 

The solution-processing of metal chalcogenides offers a promising route to improve the manufacturing of semiconductor devices. The amine–thiol solvent system has been deemed an “alkahest” for its ability to dissolve a wide range of metals and metal chalcogenides. Therefore, it enables convenient synthesis of metal sulfides. However, in the literature there are limited reports of analogous selenium-based “alkahest” chemistry. Here we show that solutions containing n-alkylammonium polyselenides can dissolve a wide range of metals and metal compounds through the formation of soluble metal polyselenides. These metal polyselenides can subsequently be utilized as precursors for the synthesis of a wide range of binary and multinary metal selenide thin films and nanoparticles, including Cu(In,Ga)Se2, Cu2ZnSnSe4, and Ag2ZnSnSe4.