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Photoacoustic microscopy was developed to achieve volumetric imaging of the anatomy and functions of the subcutaneous microvasculature in both small animals and humans in vivo with high spatial resolution and high signal-to-background ratio. By following the skin contour in raster scanning, the ultrasonic transducer maintains focusing in the region of(More)
Photoacoustic microscopy (PAM) does not rely on contrast agent to image the optical absorption contrast in biological tissue. It is uniquely suited for measuring several tissue physiological parameters, such as hemoglobin oxygen saturation, that would otherwise remain challenging. Researchers are designing new clinical diagnostic tools and multimodal(More)
Carotenoids protect the photosynthetic apparatus against harmful radicals arising from the presence of both light and oxygen. They also act as accessory pigments for harvesting solar energy, and are required for stable assembly of many light-harvesting complexes. In the phototrophic bacterium Rhodobacter (Rba.) sphaeroides phytoene desaturase (CrtI)(More)
The reaction center (RC) complex of the green sulfur bacterium Chlorobaculum tepidum is composed of the Fenna-Matthews-Olson antenna protein (FMO) and the reaction center core (RCC) complex. The RCC complex has four subunits: PscA, PscB, PscC, and PscD. We studied the FMO/RCC complex by chemically cross-linking the purified sample followed by biochemical(More)
T cell receptor (TCR) binding to diverse peptide-major histocompatibility complex (pMHC) ligands results in various degrees of T cell activation. Here we analyze which binding properties of the TCR-pMHC interaction are responsible for this variation in pMHC activation potency. We have analyzed activation of the 1G4 cytotoxic T lymphocyte clone by cognate(More)
Capillaries, the smallest blood vessels, are the distal end of the vasculature where oxygen and nutrients are exchanged between blood and tissue. Hence, noninvasive imaging of capillaries and function in vivo has long been desired as a window to studying fundamental physiology, such as neurovascular coupling. Existing imaging modalities cannot provide the(More)
PURPOSE To test the capability of a novel dual-beam Doppler optical coherence tomography (OCT) technique for simultaneous in vivo measurement of the Doppler angle and, thus, the absolute retinal blood velocity and the retinal flow rate, without the influence of motion artifacts. METHODS A novel dual-beam Doppler spectral domain OCT (SD-OCT) was developed.(More)
We have developed a non-invasive photoacoustic ophthalmoscopy (PAOM) for in vivo retinal imaging. PAOM detects the photoacoustic signal induced by pulsed laser light shined onto the retina. By using a stationary ultrasonic transducer in contact with the eyelids and scanning only the laser light across the retina, PAOM provides volumetric imaging of the(More)
Functional photoacoustic microscopy (fPAM) is a hybrid technology that permits noninvasive imaging of the optical absorption contrast in subcutaneous biological tissues. fPAM uses a focused ultrasonic transducer to detect high-frequency photoacoustic (PA) signals. Volumetric images of biological tissues can be formed by two-dimensional raster scanning, and(More)
BACKGROUND The type I insulin-like growth factor receptor (IGF1R) is a transmembrane tyrosine kinase involved in cancer proliferation, survival, and metastasis. METHODS In this study, we used two different fluorescent technologies (small-molecule fluorophores and quantum dot (QD) nanoparticles) to detect receptor expression and its downregulation by(More)