Patient‐friendly pathology reports for patients with breast atypias

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146318/1/tbj13061_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146318/2/tbj13061.pd

Assembly of Linked Nanocrystal Colloids by Reversible Covalent Bonds

The use of dynamically bonding molecules designed to reversibly link solvent-dispersed nanocrystals (NCs) is a promising strategy to form colloidal assemblies with controlled structure and macroscopic properties. In this work, tin-doped indium oxide NCs are functionalized with ligands that form reversible covalent bonds with linking molecules to drive assembly of NC gels. We monitor gelation using small angle X-ray scattering and characterize how changes in the gel structure affect infrared optical properties arising from the localized surface plasmon resonance of the NCs. The assembly is reversible because of the designed linking chemistry, and we disassemble the gels using two strategies: addition of excess NCs to change the ratio of linking molecules to NCs and addition of a capping molecule that displaces the linking molecules. The assembly behavior is rationalized using a thermodynamic perturbation theory to compute the phase diagram of the NC–linking molecule mixture. Coarse-grained molecular dynamics simulations reveal the competition between loop and bridge linking motifs essential for understanding NC gelation. This combined experimental, computational, and theoretical work provides a platform for controlling and designing the properties of reversible colloidal assemblies that incorporate NC and solvent compositions beyond those compatible with other contemporary (e.g, DNA-based) linking strategies.We would like to acknowledge the UT Mass Spectrometry Facility for their instrumental help and the UT NMR facilities for equipment use and assistance: NIH Grant Number 1 S10 OD021508-01. This work was primarily supported by the National Science Foundation through the Center for Dynamics and Control of Materials: an NSF Materials Research Science and Engineering Center (NSF MRSEC) under Cooperative Agreement DMR-1720595. This work was also supported by NSF Graduate Research Fellowships DGE-1610403 (M.N.D. and S.V.), an Arnold O. Beckman Postdoctoral Fellowship (Z.M.S.), NSF (CHE- 1905263), and the Welch Foundation (F-1848 and F-1696). E.V.A. acknowledges support from the Welch Regents Chair (F-0046). We acknowledge the Texas Advanced Computing Center (TACC) at The University of Texas at Austin for providing HPC resources.Center for Dynamics and Control of Material

Nanostructure-derived anti-reflectivity in leafhopper brochosomes

Understanding how insect-derived biomaterials interact with light has led to new advances and interdisciplinary insights in entomology and physics. Leafhoppers are insects that coat themselves with highly ordered biological nanostructures known as brochosomes. Brochosomes are thought to provide a range of protective properties to leafhoppers, such as hydrophobicity and anti-reflectivity, which has inspired the development of synthetic brochosomes that mimic their structures. Despite recent progress, the ultra-high anti-reflective properties of brochosome structures are not fully understood. In this work, we use a combination of experiments and computational modeling to understand the structure-, material-, and polarization-dependent optical properties of brochosomes modeled on the geometries found in three leafhopper species. Our results show that that Fano resonance is responsible for the ultra-high anti-reflectivity of brochosomes. Whereas prior work has focused on computational modeling of idealized pitted particles, our work shows that light-matter interactions with brochosome structures can be tuned by varying the geometry of their cage-like nanoscale features and by changing the arrangement of multi-particle assemblies. Broadly, this work establishes principles for the guided design of new optically active materials inspired by these unique insect nanostructures

Synthesis of hierarchical nanocrystal-based mesoporous materials for electrochemical supercapacitors

The ability to construct well-defined and controlled hierarchical nanostructured porous architectures is desirable for enhancing the performance of electrochem. pseudocapacitors. Here, we propose design rules for improving capacitive energy storage: use of redox-active materials, high surface area for high capacity, mesoporosity for solvent diffusion, and good electronic cond. Previous work on TiO2 nanocrystal-based porous films satisfied many of these requirements. In this work, we build on those initial results using polymer templating of preformed nanocrystals to fabricate high surface area redox-active materials, including Mn3O4 and MnFe2O4. In addn. we have prepd. mesoporous nanocrystal-based films of tin-doped indium oxide (ITO) coated with V2O5. The ITO scaffold provides a conductive pathway and facilitates electron-transfer reactions throughout the V2O5 layer. In these systems, the mesoscale porosity allows facile electrolyte diffusion throughout the material, while the nanocrystals embedded in the pore walls provide a high surface area with ample redox-active sites

Using polymer templated nanoporous materials to improve performance in electrochemical pseudocapacitors and batteries

This paper discusses two charge storage systems that exploit the unique properties of block copolymer template nanoporous materials. The first case focuses on electrochem. supercapacitors produced by polymer templating of both sol-gel type and nanocrystal building blocks. In the other case, periodic porous materials are employed to improve cycling performance in nanoporous silicon anodes for Li+ batteries

General Method for the Synthesis of Hierarchical Nanocrystal-Based Mesoporous Materials

Block copolymer templating of inorg. materials is a robust method for the prodn. of nanoporous materials. The method is limited, however, by the fact that the mol. inorg. precursors commonly used generally form amorphous porous materials that often cannot be crystd. with retention of porosity. To overcome this issue, the authors present a general method for the prodn. of templated mesoporous materials from preformed nanocrystal building blocks. The work takes advantage of recent synthetic advances that allow org. ligands to be stripped off of the surface of nanocrystals to produce sol., charge-stabilized colloids. Nanocrystals then undergo evapn.-induced co-assembly with amphiphilic diblock copolymers to form a nanostructured inorg./org. composite. Thermal degrdn. of the polymer template results in nanocrystal-based mesoporous materials. This method can be applied to nanocrystals with a broad range of compns. and sizes, and the assembly of nanocrystals can be carried out using a broad family of polymer templates. The resultant materials show disordered but homogeneous mesoporosity that can be tuned through the choice of template. The materials also show significant microporosity, formed by the agglomerated nanocrystals, and this porosity can be tuned by the nanocrystal size. The authors demonstrate through careful selection of the synthetic components that specifically designed nanostructured materials can be constructed. Because of the combination of open and interconnected porosity, high surface area, and compositional tunability, these materials are likely to find uses in a broad range of applications. For example, enhanced charge storage kinetics in nanoporous Mn3O4 is demonstrated here

Assembly of Linked Nanocrystal Colloids by Reversible Covalent Bonds

The use of dynamically bonding molecules designed to reversibly link solvent-dispersed nanocrystals (NCs) is a promising strategy to form colloidal assemblies with controlled structure and macroscopic properties. In this work, tin-doped indium oxide NCs are functionalized with ligands that form reversible covalent bonds with linking molecules to drive assembly of NC gels. We monitor gelation using small angle X-ray scattering and characterize how changes in the gel structure affect infrared optical properties arising from the localized surface plasmon resonance of the NCs. The assembly is reversible because of the designed linking chemistry, and we disassemble the gels using two strategies: addition of excess NCs to change the ratio of linking molecules to NCs and addition of a capping molecule that displacesthe linking molecules. The assembly behavior is rationalized using a thermodynamic perturbation theory to compute the phase diagram of the NC–linking molecule mixture. Coarse-grained molecular dynamics simulations reveal the competition between loop and bridge linking motifs essential for understanding NC gelation. This combined experimental, computational, and theoretical work provides a platform for controlling and designing the properties of reversible colloidal assemblies that incorporate NC and solvent compositions beyond those compatible with other contemporary (e.g, DNA-based) linking strategies.</div