A5042586928- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Bacterial Genetics and Biotechnology
- Bacterial biofilms and quorum sensing
- Perovskite Materials and Applications
- Plasmonic and Surface Plasmon Research
- Metamaterials and Metasurfaces Applications
- Quantum Dots Synthesis And Properties
- Electronic and Structural Properties of Oxides
- Organic Electronics and Photovoltaics
- 2D Materials and Applications
- Chalcogenide Semiconductor Thin Films
- Semiconductor materials and devices
- Transition Metal Oxide Nanomaterials
- Methane Hydrates and Related Phenomena
- Infections and bacterial resistance
- Thermal Radiation and Cooling Technologies
- Advanced Thermoelectric Materials and Devices
- Conducting polymers and applications
- Bacteriophages and microbial interactions
- Photonic Crystals and Applications
- Advanced Photocatalysis Techniques
- DNA Repair Mechanisms
- Near-Field Optical Microscopy
- Luminescence and Fluorescent Materials
Sandia National Laboratories
2022-2025
University of California, Riverside
2024
University of Kentucky
2016-2021
University of Basel
2009-2016
Philipps University of Marburg
2012-2016
Loewe Center for Synthetic Microbiology
2013-2016
University of Würzburg
2013
In-Q-Tel
2012
Summary Biofilms are communities of surface‐attached, matrix‐embedded microbial cells that can resist antimicrobial chemotherapy and contribute to persistent infections. Using an Escherichia coli biofilm model we found exposure bacteria subinhibitory concentrations ribosome‐targeting antibiotics leads strong induction. We present evidence this effect is elicited by the ribosome in response translational stress. Biofilm induction involves upregulation polysaccharide adhesin...
Larger dopants with high electron affinities are found to yield increased electrical conductivities and power factors at lower doping concentrations.
Surface ligand treatment provides a promising approach for passivating defect states, improving material and device stability, manipulating interfacial energetics, the performance of perovskite solar cells (PSCs). To facilitate targeted selection design surface ligands PSCs, it is necessary to establish relationships between structure properties. Herein, with different binding groups are investigated determine their extent coverage, whether they form monolayer or penetrate perovskite, how...
ABSTRACT Intracellular levels of the bacterial second messenger cyclic di-GMP (c-di-GMP) are controlled by antagonistic activities diguanylate cyclases and phosphodiesterases. The phosphodiesterase PdeH was identified as a key regulator motility in Escherichia coli , while deletions any other 12 genes encoding potential phosphodiesterases did not interfere with motility. To analyze roles E. phosphodiesterases, we demonstrated that most these proteins expressed under laboratory conditions. We...
Summary The transcription factor CsgD governing the production of curli fimbriae and cellulose is a key player in complex regulatory circuit that decides whether Escherichia coli form biofilms. csgD gene itself tightly controlled at level by large array DNA‐binding proteins, but what happens after less understood. In this issue Molecular Microbiology , Jørgensen et al. (2012 ), Mika ) Thomason report on small RNAs (McaS, RprA GcvB) together with RNA‐chaperone Hfq regulate mRNAs other biofilm...
Interfacial chemistry and energetics significantly impact the performance of photovoltaic devices. In case Pb-containing organic metal halide perovskites, photoelectron spectroscopy has been used to determine energetic alignment frontier electronic energy levels at various interfaces present in device. For Sn-containing analogues, which are less toxic, no such measurements have made. Through a combination ultraviolet, inverse, X-ray (UPS, IPES, XPS, respectively) taken varying thickness...
Precise control of light–matter interactions at the nanoscale lies heart nanophotonics. However, experimental examination this length scale is challenging since corresponding electromagnetic near-field often confined within volumes below resolution conventional optical microscopy. In semiconductor nanophotonics, fields are further restricted confines individual subwavelength resonators, limiting access to critical in these structures. work, we demonstrate that photoelectron emission...
Silylethyne-functionalized benzodithiophene serves as a universal crystal engineering core to yield stable, soluble, π-stacked arrays of aromatic chromophores.
Dielectric metasurfaces, through volume‐type photonic resonances, enable precise control of light‐matter interactions for applications including imaging, holography, and sensing. The application space dielectric metasurfaces has extended from infrared to visible wavelengths by incorporating high refractive index materials, such as titanium dioxide (TiO 2 ). Understanding the fundamental fabrication limits these requires metrology with nanoscale resolution, sensitivity electromagnetic fields...
Oxygen vacancies in HfxZr(1−x)O2 (HZO) both contribute to stabilization of the ferroelectric orthorhombic phase and promote leakage pathways that limit endurance devices based on material. For this reason, defect states oxygen were investigated using photoemission electron microscopy (PEEM) photoluminescence spectroscopy (PL), as their concentration was varied via ex situ laser exposure. Following a controlled vacancy reduction visible (2.54 eV) dosing HZO, deep-ultraviolet (DUV, 5.82 PEEM...
ABSTRACT DgcZ is the main cyclic dimeric GMP (c-di-GMP)-producing diguanylate cyclase (DGC) controlling biosynthesis of exopolysaccharide poly-β-1,6- N -acetylglucosamine (poly-GlcNAc or PGA), which essential for surface attachment Escherichia coli . Although complex regulation has previously been investigated, its primary role and physiological conditions under protein active are not fully understood. Transcription dgcZ regulated by two-component system CpxAR activated lipoprotein NlpE in...
Organometal halide perovskite photovoltaics typically contain both electron and hole transport layers, of which influence charge extraction recombination. The ionization energy (IE) the layer (HTL) is one important material property that will open-circuit voltage, fill factor, short-circuit current. Herein, we introduce a new series triarylaminoethynylsilanes with adjustable IEs as efficient HTL materials for methylammonium lead iodide (MAPbI3) based photovoltaics. three investigated can all...
In bacteria, replicative aging manifests as a difference in growth or survival between the two cells emerging from division. One cell can be regarded an mother with decreased potential for future and division, other rejuvenated daughter. Here, we aimed at investigating some of processes involved bacterium Escherichia coli, where types distinguished by age their poles. We found that certain changes regulation carbohydrate metabolism affect aging. A mutation carbon storage regulator gene,...
Engineering the transition metal dichalcogenide (TMD)-metal interface is critical for development of two-dimensional semiconductor devices. By directly probing electronic structures WS2-Au and WSe2-Au interfaces with high spatial resolution, we delineate nanoscale heterogeneities in composite systems that give rise to local Schottky barrier height modulations. Photoelectron spectroscopy reveals large variations (>100 meV) TMD work function binding energies occupied states. Characterization...
Inconsistent interface control in devices based on two-dimensional materials (2DMs) has limited technological maturation. Astounding variability of 2D/three-dimensional (2D/3D) properties been reported, which exacerbated by the lack direct investigations buried interfaces commonly found devices. Herein, we demonstrate a new process that enables assembly and isolation device-relevant heterostructures for characterization. This is achieved implementing water-soluble substrate (GeO2),...
Precise control of light-matter interactions at the nanoscale lies heart nanophotonics. Experimental examination this length scale is challenging, however, since corresponding electromagnetic near-field often confined within volumes below resolution conventional optical microscopy. In semiconductor nanophotonics fields are further restricted confines individual subwavelength resonators, limiting access to critical in these structures. work, we demonstrate that photoelectron emission...
We use photoemission electron microscopy for hyperspectral imaging of electromagnetic field localization in broken-symmetry III-V semiconductor metasurfaces with high selectivity to characterize complex resonant mode profiles, determine coherent interaction lengths, and corroborate FDTD simulations.
Experimental examination of light-matter interactions at the nanoscale is challenging since corresponding electromagnetic near-field often confined within volumes below resolution conventional optical microscopy. Here, we demonstrate that photoemission electron microscopy (PEEM) can image fields in nanophotonic structures. We present concurrent spectroscopy and imaging distribution resonance modes supported by broken-symmetry silicon metasurfaces. Additionally, examine collective deduce...