A5062278190- Photoacoustic and Ultrasonic Imaging
- Advanced Fluorescence Microscopy Techniques
- Optical Imaging and Spectroscopy Techniques
- Cardiovascular Health and Disease Prevention
- Photodynamic Therapy Research Studies
- Cerebrovascular and Carotid Artery Diseases
- Retinal Diseases and Treatments
- Coronary Interventions and Diagnostics
- Optical Coherence Tomography Applications
- Glaucoma and retinal disorders
- Cardiac Imaging and Diagnostics
- Aortic aneurysm repair treatments
- Advanced Optical Sensing Technologies
- Retinal Imaging and Analysis
- Hemodynamic Monitoring and Therapy
- Ocular Oncology and Treatments
- Venous Thromboembolism Diagnosis and Management
- Protein Interaction Studies and Fluorescence Analysis
- Blood properties and coagulation
- Cardiovascular Disease and Adiposity
- Aortic Disease and Treatment Approaches
- Spectroscopy Techniques in Biomedical and Chemical Research
- Peripheral Artery Disease Management
- Nitric Oxide and Endothelin Effects
- Atherosclerosis and Cardiovascular Diseases
Ophthalmology Clinic
2023-2024
Essen University Hospital
2019-2024
University of Duisburg-Essen
2021-2022
Imperial College London
2002-2016
Ruhr University Bochum
2013-2016
University of London
2015
Charing Cross Hospital
1997-2003
Instituto de Óptica "Daza de Valdés"
2003
Hammersmith Hospital
2003
St Thomas' Hospital
2003
The influence of luminal pressure and endothelial removal on fluid filtration across the arterial wall has been studied in rabbit thoracic aorta. Segments aorta were excised such a way as to prevent shortening depressurization filled with 4% albumin-Tyrode solution. Experiments carried out at two controlled levels (70 180 mmHg). hydraulic conductivity (Lp) total wall, calculated from data, was 4.00 +/- 1.31 2.44 0.80 (SD) X 10(-8) cm/(s mmHg) intact 70 mmHg, respectively (P less than 0.01),...
We describe a novel whole-field fluorescence lifetime imaging system, based on time-gated image intensifier and solid-state laser oscillator-amplifier, that images differences of less than 10 ps. This system was successfully applied to discrimination between biological tissue constituents.
A whole‐field time‐domain fluorescence lifetime imaging (FLIM) microscope with the capability to perform optical sectioning is described. The excitation source a mode‐locked Ti:Sapphire laser that regeneratively amplified and frequency doubled 415 nm. Time‐gated intensity images at increasing delays after are acquired using gated microchannel plate image intensifier combined an intensified CCD camera. By fitting single or multiple exponential decay each pixel in field of view time‐gated...
We have applied fluorescence lifetime imaging (FLIM) to the autofluorescence of different kinds biological tissue in vitro, including animal sections and knee joints as well human teeth, obtaining two-dimensional maps with functional contrast. find that decay profiles are described by stretched exponential function (StrEF), which can represent complex nature tissue. The StrEF yields a continuous distribution lifetimes, be extracted an inverse Laplace transformation, additional information is...
Abdominal aortic aneurysms are characterized by intimal atherosclerosis, disruption and attenuation of the elastic media, a variable adventitial inflammatory infiltrate. We have developed an animal model this disorder to evaluate contribution hypercholesterolemia, medial injury, inflammation aneurysmal dilatation. To accomplish this, we used periaortic application calcium chloride, which induced both injury with calcification endothelial injury. Ultrasonography was demonstrate dilatation...
We report the development of a high-speed wide-field fluorescence-lifetime imaging (FLIM) system that provides images at rates as many 29 frames/s. A FLIM multiwell plate reader and potentially portable endoscopic operating 355-nm excitation have been demonstrated.
This article describes a wide-field time-domain fluorescence lifetime imaging (FLIM) microscope with optical sectioning. The FLIM system utilizes time-gated image intensifier, minimum gate width of 85 ps, to achieve high temporal resolution decays induced by ultrashort laser pulses. Different configurations, using excitation pulses picojoule energy at 80 MHz repetition rate and nanojoule 10 kHz, are compared. instrument has dynamic range spanning from 100 ps tens μs is shown have...
Abstract Fourier transform infrared (FTIR) spectroscopic imaging using a focal plane array detector has been used to study atherosclerotic arteries with spatial resolution of 3–4 μm, i.e., at level that is comparable cellular dimensions. Such high made possible micro‐attenuated total reflection (ATR) germanium objective refractive index and therefore numerical aperture. This micro‐ATR approach enabled small structures within the vessel wall be imaged for first time by FTIR. Structures...
High-speed (video-rate) fluorescence lifetime imaging (FLIM) is reported using two different time-domain approaches based on gated optical image intensifier technology. The first approach utilizes a rapidly switchable variable delay generator with sequential acquisition, while the second employs novel segmented imager to acquire maps in single shot. Lifetimes are fitted both non-linear least-squares fit analysis and rapid determination method. Monte Carlo simulations were used optimize...
High-speed (video-rate) fluorescence lifetime imaging (FLIM) through a flexible endoscope is reported based on gated optical image intensifier technology. The optimization and potential application of FLIM to tissue autofluorescence for clinical applications are discussed.
The interaction of convection and diffusion in the transport 131I-labeled albumin within wall rabbit thoracic aorta was studied vessels excised at vivo length. They were pressurized with a solution containing no tracer immersed labeled albumin. label then entered tissue via adventitia had to diffuse against convective flux which occurred from lumen adventitia. Experiments performed on intact deendothelialized 70 180 mm Hg. At end each experiment subjected sequential frozen sectioning...
We describe a novel three-dimensional fluorescence lifetime imaging microscope that exploits structured illumination to achieve whole-field sectioned images with spatial resolution of few micrometers.
Abstract We report a rapid hyperspectral fluorescence lifetime imaging (FLIM) instrument that exploits high‐speed FLIM technology in line‐scanning microscope. demonstrate the acquisition of whole‐field optically sectioned image stacks (with 32 spectral bins) less than 40 s and illustrate its application to unstained biological tissue. Microsc. Res. Tech., 2007. © 2007 Wiley‐Liss, Inc.
We report a novel whole-field three-dimensional fluorescence lifetime imaging microscope that incoporates multispectral to provide five-dimensional (5-D) microscopy. This instrument, which can acquire 5-D data set in less than minute, is based on potentially compact and inexpensive diode-pumped solid-state laser technology. demonstrate spectral discrimination as well optical sectioning minimize artifacts determination illustrate how improves the contrast of biological tissue.
To measure the distribution volume for sucrose and albumin in media of rabbit thoracic aorta, we studied uptake tracers vitro. In most cases were applied to both luminal adventitial surfaces at same concentration. When transmural convection was prevented by pressurization arteries with air, there a decrease space (19% 70 mmHg 28% 180 mmHg) (60% 66% mmHg), compared respective spaces relaxed (0.42 0.08 albumin). Much smaller changes found when intact vessels pressurized liquid (insignificant...
Abstract We report the development of a whole-field fluorescence lifetime imaging (FLIM) system with high temporal resolution based on time-gated image intensifier. The optimized gate width is < 100 ps, and changes in environment fluorescent phantom, causing differences less than 10 have been imaged. versatility this FLIM has demonstrated by measuring both spectral profiles multiple samples single acquisition. Initial images suggest that technique can provide means distinguishing between...
We report a wide-field fluorescence lifetime imaging (FLIM) system that uses blue picosecond pulsed diode laser as the excitation source. This represents significant miniaturization and simplification compared with other time-domain FLIM instruments should accelerate development of clinical real-world applications FLIM. have demonstrated this instrument in two configurations: macroimaging setup applied to multiwell plate assays chemically biologically interesting fluorophores microscope has...
The steady‐state flow of fluid across the wall isolated rabbit common carotid artery has been measured in presence and absence within lumen vessel. perfusate solution contained either 10 or 40 mg ml‐1 albumin transmural flux was by monitoring rate movement into a chamber enclosing artery. Vasomotion minimized inclusion vasodilator sodium nitrite both outer bathing solution. A relatively slow luminal caused reversible increase 20‐30% relative to value flow. mechanism responsible for is not...
Abstract Blood velocity profiles were measured in the renal branch (diameter 5.9±1.3 mm) of aortorenal bifurcation using a 20-MHz 80-channel pulsed Doppler velocimeter during retroperitoneal surgery 10 patients. The peak Reynolds number was 1145±140 and frequency parameter (Wormersley parameter) 3.0±0.8. Immediately distal to ostium artery, reverse flow, indicating flow separation, observed near cranial wall mainly first part cardiac cycle. There flows from caudal side artery at this...