Overlapping fingerprints are often found at crime scenes, but only individual fingerprints separa... more Overlapping fingerprints are often found at crime scenes, but only individual fingerprints separated from each other are admissible as evidence in court. Fingerprint components differ slightly among individuals, and thus their fluorescence spectra also differ from each other. Therefore, the separation of overlapping fingerprints using the difference of the fluorescence spectrum was performed with a hyperspectral imager. Hyperspectral data (HSD) of overlapping fingerprints were recorded under UV LED excitation. Principal component analysis (PCA) and multivariate curve resolution-alternating least squares (MCR-ALS) were applied to the HSD to determine the optimal method for obtaining high-contrast images of individual fingerprints. The results suggested that MCR-ALS combined with PCA-based initialization is capable of separating overlapping fingerprints into individual fingerprints. In this study, a method for separating overlapping fingerprints without initial parameters was proposed.
Background— Patients treated for transposition of the great arteries by atrial redirection surger... more Background— Patients treated for transposition of the great arteries by atrial redirection surgery have a right ventricle (RV) that sustains systemic pressures long term. Late RV dysfunction occurs in these patients; the reasons for this are unclear, but myocardial fibrosis may be important. Myocardial fibrosis can be visualized by late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR). We hypothesized that LGE would be present in the systemic RV and relate to adverse clinical features. Methods and Results— We performed CMR on 36 consecutive adult patients (mean age, 27 years) after atrial redirection surgery for transposition of the great arteries. Late gadolinium RV enhancement was seen in 22 patients (61%) with various patterns. Patients with RV LGE were older (30 versus 22 years; P <0.001) and had increased RV end-systolic volume index (43 versus 35 mL/m 2 ; P =0.03), decreased RV ejection fraction (57% versus 62%; P =0.02), increased QRS duration (108 vers...
We present our first steps towards nanoparticle assisted, optical molecular imaging (NAOMI) using... more We present our first steps towards nanoparticle assisted, optical molecular imaging (NAOMI) using biodegradable nanoparticles. Our focus is on using optical coherence tomography(OCT) as the imaging modality. We propose to use nanoparticles based on biodegradable polymers, loaded with carefully selected dyes as contrast agent, and outline a method for establishing their desired optical properties prior to synthesis. Moreover, we perform a qualitative pilot study using these biodegradable nanoparticles, measuring their optical properties which are found to be in line with theoretical predictions.
Imaging of human autopsy samples was performed from the luminal side with a high (3.5 mum axial a... more Imaging of human autopsy samples was performed from the luminal side with a high (3.5 mum axial and 7 mum lateral) resolution OCT system (around 800 nm) or a regular (15-20 mum axial and 20 mum lateral resolution) OCT system (around 1300 nm). For each sample, dimensions were measured by histomorphometry and OCT and the optical attenuation was measured. Quantitative
The feasibility of using Optical Coherence Tomography (OCT) for oxygenation determination of whol... more The feasibility of using Optical Coherence Tomography (OCT) for oxygenation determination of whole blood was investigated on porcine blood samples. Our data show a sensitivity in the OCT spectral content to changes in oxygenation that qualitatively correspond to expectations based on the absorption spectra of oxidized hemoglobin and hemoglobin.
We determined the scattering coefficient and scattering anisotropy of blood samples with varying ... more We determined the scattering coefficient and scattering anisotropy of blood samples with varying hematocrit using optical coherence tomography measurements and a curve fitting procedure. Initial results show much lower scattering coefficient and scattering anisotropy than theoretically expected, which are likely attributed to the highly forward scattering nature of blood.
Apoptosis is the effector of regulated cell death and plays a role in many physiologic and pathol... more Apoptosis is the effector of regulated cell death and plays a role in many physiologic and pathologic processes. It is characterized by a highly regulated condensation and fragmentation of the cell nucleus, and breakup of the entire cell into vesicles, (apoptotic bodies) containing cell organelles and fragments of the nucleus. Previous experiments indicate that changes in optical properties after induction of apoptosis might be detected using optical imaging systems, such as optical coherence tomography (OCT), due to an increase in scattering of apoptotic cells. The previous in vitro experiments are extended to ex vivo and in vivo experiments. A nearly two-fold increase in attenuation coefficient is observed in a tissue culture of porcine carotid artery, in which apoptosis is induced by balloon dilation, and a significant 20 % increase in an in vivo setup. The preliminary results of this study indicate that the apoptotic process may also be detected ex vivo and in vivo using optical imaging systems, such as optical coherence tomography (OCT), due to an increase in scattering by the typical disintegration of cellular material.
The development of fingermarks is an important step in visualizing ridge patterns for individuali... more The development of fingermarks is an important step in visualizing ridge patterns for individualization purposes. Immunolabeling can be applied to fingermarks to selectively and sensitively detect antigens in fingermarks, and can be used as a developing method to visualize fingermarks. In this study we investigated single (the detection of one antigen) and multiple targeting approaches (the detection of multiple antigens simultaneously) to improve fingermark development. The detection of dermcidin, an antimicrobial peptide, was used as the gold standard to compare single and multi-target detection of keratins, albumin and/or dermcidin. Single detection of dermcidin and albumin mostly resulted in clear ridge details and/or pore detection, whereas the single keratin detection resulted in a poor visualization of the fingermarks. The multi-target approach in which both dermcidin and albumin were targeted, resulted in improved fingermark development compared to single dermcidin detection. Therefore, we recommend the use of multi-target detection consisting of anti-dermcidin and anti-albumin when using immunolabeling as fingermark development technique. Additionally, the optimized multi-target approach was tested as a pre- and post-development technique in combination with powder dusting and cyanoacrylate fuming. Immunolabeling has not been implemented yet in forensic case work, however we expect that immunolabeling can be used to redevelop poorly developed and/or smudged fingermarks in the nearby future. Currently, an ongoing pilot-study is being conducted in collaboration with the Dutch police.
Overlapping fingerprints are often found at crime scenes, but only individual fingerprints separa... more Overlapping fingerprints are often found at crime scenes, but only individual fingerprints separated from each other are admissible as evidence in court. Fingerprint components differ slightly among individuals, and thus their fluorescence spectra also differ from each other. Therefore, the separation of overlapping fingerprints using the difference of the fluorescence spectrum was performed with a hyperspectral imager. Hyperspectral data (HSD) of overlapping fingerprints were recorded under UV LED excitation. Principal component analysis (PCA) and multivariate curve resolution-alternating least squares (MCR-ALS) were applied to the HSD to determine the optimal method for obtaining high-contrast images of individual fingerprints. The results suggested that MCR-ALS combined with PCA-based initialization is capable of separating overlapping fingerprints into individual fingerprints. In this study, a method for separating overlapping fingerprints without initial parameters was proposed.
Background— Patients treated for transposition of the great arteries by atrial redirection surger... more Background— Patients treated for transposition of the great arteries by atrial redirection surgery have a right ventricle (RV) that sustains systemic pressures long term. Late RV dysfunction occurs in these patients; the reasons for this are unclear, but myocardial fibrosis may be important. Myocardial fibrosis can be visualized by late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR). We hypothesized that LGE would be present in the systemic RV and relate to adverse clinical features. Methods and Results— We performed CMR on 36 consecutive adult patients (mean age, 27 years) after atrial redirection surgery for transposition of the great arteries. Late gadolinium RV enhancement was seen in 22 patients (61%) with various patterns. Patients with RV LGE were older (30 versus 22 years; P <0.001) and had increased RV end-systolic volume index (43 versus 35 mL/m 2 ; P =0.03), decreased RV ejection fraction (57% versus 62%; P =0.02), increased QRS duration (108 vers...
We present our first steps towards nanoparticle assisted, optical molecular imaging (NAOMI) using... more We present our first steps towards nanoparticle assisted, optical molecular imaging (NAOMI) using biodegradable nanoparticles. Our focus is on using optical coherence tomography(OCT) as the imaging modality. We propose to use nanoparticles based on biodegradable polymers, loaded with carefully selected dyes as contrast agent, and outline a method for establishing their desired optical properties prior to synthesis. Moreover, we perform a qualitative pilot study using these biodegradable nanoparticles, measuring their optical properties which are found to be in line with theoretical predictions.
Imaging of human autopsy samples was performed from the luminal side with a high (3.5 mum axial a... more Imaging of human autopsy samples was performed from the luminal side with a high (3.5 mum axial and 7 mum lateral) resolution OCT system (around 800 nm) or a regular (15-20 mum axial and 20 mum lateral resolution) OCT system (around 1300 nm). For each sample, dimensions were measured by histomorphometry and OCT and the optical attenuation was measured. Quantitative
The feasibility of using Optical Coherence Tomography (OCT) for oxygenation determination of whol... more The feasibility of using Optical Coherence Tomography (OCT) for oxygenation determination of whole blood was investigated on porcine blood samples. Our data show a sensitivity in the OCT spectral content to changes in oxygenation that qualitatively correspond to expectations based on the absorption spectra of oxidized hemoglobin and hemoglobin.
We determined the scattering coefficient and scattering anisotropy of blood samples with varying ... more We determined the scattering coefficient and scattering anisotropy of blood samples with varying hematocrit using optical coherence tomography measurements and a curve fitting procedure. Initial results show much lower scattering coefficient and scattering anisotropy than theoretically expected, which are likely attributed to the highly forward scattering nature of blood.
Apoptosis is the effector of regulated cell death and plays a role in many physiologic and pathol... more Apoptosis is the effector of regulated cell death and plays a role in many physiologic and pathologic processes. It is characterized by a highly regulated condensation and fragmentation of the cell nucleus, and breakup of the entire cell into vesicles, (apoptotic bodies) containing cell organelles and fragments of the nucleus. Previous experiments indicate that changes in optical properties after induction of apoptosis might be detected using optical imaging systems, such as optical coherence tomography (OCT), due to an increase in scattering of apoptotic cells. The previous in vitro experiments are extended to ex vivo and in vivo experiments. A nearly two-fold increase in attenuation coefficient is observed in a tissue culture of porcine carotid artery, in which apoptosis is induced by balloon dilation, and a significant 20 % increase in an in vivo setup. The preliminary results of this study indicate that the apoptotic process may also be detected ex vivo and in vivo using optical imaging systems, such as optical coherence tomography (OCT), due to an increase in scattering by the typical disintegration of cellular material.
The development of fingermarks is an important step in visualizing ridge patterns for individuali... more The development of fingermarks is an important step in visualizing ridge patterns for individualization purposes. Immunolabeling can be applied to fingermarks to selectively and sensitively detect antigens in fingermarks, and can be used as a developing method to visualize fingermarks. In this study we investigated single (the detection of one antigen) and multiple targeting approaches (the detection of multiple antigens simultaneously) to improve fingermark development. The detection of dermcidin, an antimicrobial peptide, was used as the gold standard to compare single and multi-target detection of keratins, albumin and/or dermcidin. Single detection of dermcidin and albumin mostly resulted in clear ridge details and/or pore detection, whereas the single keratin detection resulted in a poor visualization of the fingermarks. The multi-target approach in which both dermcidin and albumin were targeted, resulted in improved fingermark development compared to single dermcidin detection. Therefore, we recommend the use of multi-target detection consisting of anti-dermcidin and anti-albumin when using immunolabeling as fingermark development technique. Additionally, the optimized multi-target approach was tested as a pre- and post-development technique in combination with powder dusting and cyanoacrylate fuming. Immunolabeling has not been implemented yet in forensic case work, however we expect that immunolabeling can be used to redevelop poorly developed and/or smudged fingermarks in the nearby future. Currently, an ongoing pilot-study is being conducted in collaboration with the Dutch police.
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Papers by Maurice Aalders