11 research outputs found
Beyond backscattering: Optical neuroimaging by BRAD
Optical coherence tomography (OCT) is a powerful technology for rapid
volumetric imaging in biomedicine. The bright field imaging approach of
conventional OCT systems is based on the detection of directly backscattered
light, thereby waiving the wealth of information contained in the angular
scattering distribution. Here we demonstrate that the unique features of
few-mode fibers (FMF) enable simultaneous bright and dark field (BRAD) imaging
for OCT. As backscattered light is picked up by the different modes of a FMF
depending upon the angular scattering pattern, we obtain access to the
directional scattering signatures of different tissues by decoupling
illumination and detection paths. We exploit the distinct modal propagation
properties of the FMF in concert with the long coherence lengths provided by
modern wavelength-swept lasers to achieve multiplexing of the different modal
responses into a combined OCT tomogram. We demonstrate BRAD sensing for
distinguishing differently sized microparticles and showcase the performance of
BRAD-OCT imaging with enhanced contrast for ex vivo tumorous tissue in
glioblastoma and neuritic plaques in Alzheimer's disease
Platelet serotonin in combat related posttraumatic stress disorder with psychotic symptoms
Background: Combat-related posttraumatic stress disorder (PTSD) is severe form of PTSD, frequently associated with psychotic symptoms. Platelet serotonin (5-hydroxytryptamine, 5-HT) was used as a peripheral 5-HT marker to identify particular symptoms in PTSD. ----- Methods: Platelet 5-HT was determined fluorimetrically in 67 war veterans with combat related PTSD. 36 combat exposed veterans who did not develop PTSD, 35 veterans with PTSD complicated with psychotic features. PTSD diagnosis of current and chronic PTSD, and clinical symptoms of PTSD and psychoses were assessed according to DSM-IV criteria, using the Clinician Administrated PTSD Scale, and Positive and Negative Syndrome Scale (PANSS). ----- Results: Platelet 5-HT concentration was significantly higher in veterans with psychotic PTSD than in veterans with non-psychotic PTSD, veterans without PTSD, or in control subjects. Platelet 5-HT was significantly positively correlated with the positive symptoms in PANSS subscale, and with the symptoms of delusions within PANSS positive subscale. ----- Limitations: The results were obtained on peripheral 5-HT marker, i.e. platelet 5-HT concentration. ----- Conclusions: Since the delusions are the core psychotic symptoms occurring in our psychotic PTSD patients, the result of the increased platelet 5-HT concentration, associated with delusions, indicate that platelet 5-HT might be used as a trait marker of psychotic symptoms in PTSD, but not as a state marker for PTSD. reserved
The lack of association between monoamine oxidase (MAO) intron 13 polymorphism and platelet MAO-B activity among men
Monoamine oxidase (MAO), a mitochondrial flavine containing enzyme, exists in two isoenzymes, MAO-A and MAO-B. Platelets contain MAO-B subtype, proposed to be a biomarker for different personality characteristics and vulnerability for substance abuse. The most common polymorphism of MAO-B gene, a single base change (A or G) occurs in intron 13. It has been proposed to be a functional polymorphism, controlling the activity of MAO-B in platelets. The aim of the study was to determine the association between platelet MAO-B activity and MAO-B intron 13 polymorphism in 225 racially and ethnically uniform healthy Caucasian men of the Croatian origin. Our results showed that platelet MAO-B activity did not differ between subjects subdivided into those with A-allele or G-allele. This polymorphism of the MAO-B gene did not control the activity of the MAO-B in platelets. Platelet MAO-B activity was associated only with the smoking status, and it was significantly decreased in smokers when compared to nonsmokers. No significant association was found between MAO-B polymorphism and smoking status. In healthy individuals of the Croatian origin, the studied MAO-B polymorphism showed a lack of functional importance in regulating MAO-B activity in platelets. Since different populations may vary in the association between functional polymorphism and the MAO-B activity, and the genotype of transcription factor AP-2β was reported to be associated with altered platelet MAO-B activity, and with specific personality traits, further studies on different populations should be conducted to elucidate the molecular mechanism/s regulating platelet MAO-B activity
Femtosecond Laser-Processing of Pre-Anodized Ti-Based Bone Implants for Cell-Repellent Functionalization
Microstructures and nanostructures can be used to reduce the adhesion of the cells on the auxiliary material. Therefore, the aim of our work was to fabricate laser-induced hierarchical microstructures and nanostructures by femtosecond laser-treatment (wavelength 1040 nm, pulse length 350 fs, repetition rates in the kHz range) to reduce the cell adhesion. Additionally, surface chemistry modification by optimized electrochemical anodization was used to further reduce the cell adhesion. For testing, flat plates and bone screws made of Ti-6Al-4V were used. Bone-forming cells (human osteoblasts from the cell line SAOS-2) were grown on the bone implants and additional test samples for two to three weeks. After the growth period, the cells were characterized by scanning electron microscopy (SEM). While earlier experiments with fibroblasts had shown that femtosecond laser-processing followed by electrochemical anodization had a significant impact on cell adhesion reduction, for osteoblasts the same conditions resulted in an activation of the cells with increased production of extracellular matrix material. Significant reduction of cell adhesion for osteoblasts was only obtained at pre-anodized surfaces. It could be demonstrated that this functionalization by means of femtosecond laser-processing can result in bone screws that hinder the adhesion of osteoblasts
3D Digital Preservation, Presentation, and Interpretation of Wooden Cultural Heritage on the Example of Sculptures of the FormaViva Kostanjevica Na Krki Collection
The paper presents an interdisciplinary approach to the treatment of the FormaViva collection of wooden sculptures exhibited outdoors in a natural environment near the Božidar Jakac Art Museum in Kostanjevica na Krki in Slovenia. The study focuses on 3D graphic representations of sculptures created with photogrammetry and 3D modelling. The results are photorealistic renderings, interactive presentations, 3D printed reproductions, jewellery, and interpretive animations. The research results show that graphic documentation techniques on 3D models allow for a more detailed investigation of the original structural identity of the sculpture. By incorporating 3D and interactive technologies, we are expanding the usability of cultural heritage objects. By using interpretive techniques that have led to jewellery and interpretive animations in our research, we not only breathe new life into the sculptures, but also enrich the stories of the sculptures with our own experiences of the sculptural work