A5057664928- Photoacoustic and Ultrasonic Imaging
- Ultrasound and Hyperthermia Applications
- Ultrasound Imaging and Elastography
- Fluorine in Organic Chemistry
- Radical Photochemical Reactions
- Catalytic C–H Functionalization Methods
- Cyclopropane Reaction Mechanisms
- Advanced Biosensing Techniques and Applications
- Micro and Nano Robotics
- Microfluidic and Bio-sensing Technologies
- Nanoplatforms for cancer theranostics
- RNA Interference and Gene Delivery
- Spectroscopy Techniques in Biomedical and Chemical Research
- Advanced Chemical Sensor Technologies
- Force Microscopy Techniques and Applications
- Lipid Membrane Structure and Behavior
- Atomic and Subatomic Physics Research
- Molecular Biology Techniques and Applications
- Ultrasonics and Acoustic Wave Propagation
- Quantum, superfluid, helium dynamics
- Protist diversity and phylogeny
- Hemoglobin structure and function
- Biosensors and Analytical Detection
- Nanoparticle-Based Drug Delivery
- Advancements in PLL and VCO Technologies
California Institute of Technology
2018-2024
Johns Hopkins University
2014-2023
Pasadena City College
2023
Division of Chemistry
2019-2023
We have discovered a highly regioselective aminofluorination of cyclopropanes. Remarkably, four unique sets conditions-two photochemical, two purely chemical-generated the same aminofluorinated adducts in good to excellent yields. The multiple, diverse ways which reaction could be initiated provided valuable clues that led proposal "unifying" chain propagation mechanism beyond initiation, tied by common intermediate. In all, proposed herein is substantiated product distribution studies,...
External control of chemical reactions in biological settings with spatial and temporal precision is a grand challenge for noninvasive diagnostic therapeutic applications. While light conventional stimulus remote activation, its penetration severely attenuated tissues, which limits applicability. On the other hand, ultrasound biocompatible energy source that highly penetrant offers wide range functional tunability. Coupling to activation specific under physiological conditions, however,...
We offer a mild, metal-free sp3 C–H fluorination alternative using Selectfluor and substoichiometric amount of triethylborane—an established radical initiator in the presence O2. This radical-chain-based synthetic method is particularly noteworthy as an offspring insight gained from mechanistic study copper-promoted aliphatic fluorination, constructively turning O2 enemy to ally. Furthermore, BEt3/O2 preferred industrial processes, it economical, low toxicity, lends way easier workup.
Phagocytic clearance and lysosomal processing of pathogens debris are essential functions the innate immune system. However, assessment these in vivo is challenging because most nanoscale contrast agents compatible with noninvasive imaging techniques made from nonbiodegradable synthetic materials that do not undergo regular degradation. To overcome this challenge, we describe use an all-protein agent to directly visualize quantify phagocytic activities by ultrasound imaging. This based on...
Nanotechnology offers significant advantages for medical imaging and therapy, including enhanced contrast precision targeting. However, integrating these benefits into ultrasonography is challenging due to the size stability constraints of conventional bubble-based agents. Here bicones, truly tiny acoustic agents based on gas vesicles (GVs), a unique class air-filled protein nanostructures naturally produced in buoyant microbes, are described. It shown that sub-80 nm particles can be...
Ultrasound and hyperpolarized magnetic resonance imaging enable the visualization of biological processes in deep tissues. However, few molecular contrast agents are available to connect these modalities specific aspects function. We recently discovered that a unique class gas‐filled protein nanostructures known as gas vesicles could serve nanoscale reporters for modalities. need produce via expression specialized cultures cyanobacteria or haloarchaea limits their broader adoption by other...
Hemodynamic functional ultrasound imaging (fUS) of neural activity provides a unique combination spatial coverage, spatiotemporal resolution and compatibility with freely moving animals. However, deep transcranial monitoring brain the dynamics in slow-flowing blood vessels remains challenging. To enhance fUS capabilities, we introduce biomolecular hemodynamic enhancers based on gas vesicles (GVs), genetically encodable contrast agents derived from buoyant photosynthetic microorganisms. We...
In 2015, we reported a photochemical method for directed C-C bond cleavage/radical fluorination of relatively unstrained cyclic acetals using Selectfluor and catalytic 9-fluorenone. Herein, provide detailed mechanistic study this reaction, during which it was discovered that the key electron transfer step proceeds through substrate oxidation from Selectfluor-derived N-centered radical intermediate (rather than initially suspected photoinduced transfer). This finding led to proof concept two...
Gas vesicles (GVs) are genetically encoded, air-filled protein nanostructures of broad interest for biomedical research and clinical applications, acting as imaging therapeutic agents ultrasound, magnetic resonance, optical techniques. However, the applications GVs systemically injectable nanomaterials have been hindered by a lack understanding GVs' interactions with blood components, which can significantly impact in vivo behavior. Here, we investigate dynamics bloodstream using combination...
Ultrasound is playing an emerging role in molecular and cellular imaging thanks to new micro- nanoscale contrast agents reporter genes. Acoustic methods for the selective vivo detection of these are needed maximize their impact biology medicine. Existing ultrasound pulse sequences use nonlinearity agents' response acoustic pressure distinguish them from mostly linear tissue scattering. However, such typically scan sample using focused transmissions, resulting a limited frame rate restricted...
Nanotechnology offers significant advantages for medical imaging and therapy, including enhanced contrast precision targeting. However, integrating these benefits into ultrasonography has been challenging due to the size stability constraints of conventional bubble-based agents. Here we describe bicones, truly tiny acoustic agents based on gas vesicles, a unique class air-filled protein nanostructures naturally produced in buoyant microbes. We show that sub-80 nm particles can be effectively...
Abstract Functional ultrasound imaging enables sensitive, high-resolution of neural activity in freely behaving animals and human patients. However, the skull acts as an aberrating absorbing layer for sound waves, leading to most functional experiments being conducted after removal. In pre-clinical settings, craniotomies are often covered with a polymethylpentene film, which offers limited longitudinal imaging, due film’s poor conformability, mechanical protection, low stiffness. Here, we...
Gas vesicles (GVs) are genetically encoded, air-filled protein nanostructures of broad interest for biomedical research and clinical applications, acting as imaging therapeutic agents ultrasound, magnetic resonance, optical techniques. However, the applications GVs a systemically injectable nanomaterial have been hindered by lack understanding GVs' interactions with blood components, which can significantly impact in vivo performance. Here, we investigate dynamics bloodstream using...
Cost-efficient, point-of-use diagnostics are critical for early disease detection. Traditionally, the majority of lab-based analysis equipment utilizes fluorescent markers biodetection assays. However, magnetic-based labels have recently been shown to be promising alternatives tags DNA, protein, and cell Magnetic assays offer several key advantages over their counterparts, namely that magnetic beads do not suffer from signal decay due bleaching they can detected with cheap CMOS-based...
ABSTRACT Gas vesicles (GVs) based on acoustic reporter genes have emerged as potent contrast agents for cellular and molecular ultrasound imaging. These air-filled, genetically encoded protein nanostructures can be expressed in a variety of cell types vivo to visualize location activity or injected systemically label monitor tissue function. Distinguishing GVs from signal deep inside intact organisms requires imaging approaches such amplitude modulation (AM) collapse-based pulse sequences,...
Gas vesicles (GVs) based on acoustic reporter genes have emerged as potent contrast agents for cellular and molecular ultrasound imaging. These air-filled, genetically encoded protein nanostructures can be expressed in a variety of cell types vivo to visualize location activity or injected systemically label monitor tissue function. Distinguishing GV signal from deep inside intact organisms requires imaging approaches such amplitude modulation (AM) collapse-based pulse sequences. However,...
A 2x2 magnetic spectrometer array using a concurrent dual-frequency transformer-based oscillator in 65nm CMOS is presented. Concurrent operation allows compensation of the drift free-running sensing without reconfiguring to switch frequency oscillation, which enables wash-free label assays and single-site multiplexed spectroscopy. The achieves sensitivity 0.7ppm consuming only 3.1mW per cell over wide range 1.2-1.65/2.9-4 GHz. biotin-streptavidin immunoassay iron oxide nanoparticle labels...
ABSTRACT Ultrasound is playing an emerging role in molecular and cellular imaging thanks to new micro- nanoscale contrast agents reporter genes. Acoustic methods for the selective vivo detection of these are needed maximize their impact biology medicine. Existing ultrasound pulse sequences use nonlinearity agents’ response acoustic pressure distinguish them from mostly linear tissue scattering. However, such typically scan sample using focused transmissions, resulting a limited frame rate...
Abstract A simple protocol is presented for the highly regioselective photochemical aminofluorination of cyclopropanes with N‐F reagents.
ABSTRACT Hemodynamic functional ultrasound imaging (fUS) of neural activity provides a unique combination spatial coverage, spatiotemporal resolution and compatibility with freely moving animals. However, deep transcranial monitoring brain the dynamics in slow-flowing blood vessels remains challenging. To enhance fUS capabilities, we introduce biomolecular hemodynamic enhancers based on gas vesicles (GVs), genetically encodable contrast agents derived from buoyant photosynthetic...