Search results for "Biomedical engineering"
showing 10 items of 2020 documents
Modular Assembly of Multimodal Imaging Agents through an Inverse Electron Demand Diels–Alder Reaction
2019
International audience; The combination of two imaging probes on a same biomolecule gives access to targeted bimodal imaging agents that can provide more accurate diagnosis, complementary information, or that may be used in different applications, such as PET imaging and fluorescence imagingassisted surgery. In this study, we demonstrate that dichlorotetrazine, a small, commercially available compound, can be used as a modular platform to easily assemble various imaging probes. Doubly-labeled tetrazines can then be conjugated to a protein through a biorthogonal IEDDA reaction. A series of difunctionalized tetrazine compounds containing various chelating agents and fluorescent dyes was synth…
Soft tissue integration of different abutment surfaces: An experimental study with histological analysis
2021
OBJECTIVE To evaluate whether abutment surface and surface bio-activation have an effect on soft tissue morphogenesis. MATERIALS AND METHODS 36 patients (36 implants) were included. Abutments were randomly divided into 4 groups (n = 9): Smooth Surface-MAChined (MAC), Ultrathin Threaded Microsurface (UTM), MAC Plasma of Argon activated (Plasma-MAC), and UTM Plasma of Argon activated (Plasma-UTM). After 2 months of healing, soft tissue samples were collected and prepared for histological analysis. The margin of the peri-implant mucosa (PM), the apical extension of the barrier epithelium (aJE), and the apical location of the abutment (AM) were identified. Significances of differences among gro…
Possible Implications for Improved Osteogenesis? The Combination of Platelet-Rich Fibrin With Different Bone Substitute Materials
2021
Bone substitute materials (BSM) are widely used in oral regeneration, but sufficient angiogenesis is crucial for osteogenesis. The combination of BSM with autologous thrombocyte concentrations such as platelet-rich fibrin (PRF) may represent a clinical approach to overcome this limitation. This study analyzes the early influence on osteoblast (HOB) in vitro. Here, four different BSM (allogeneic, alloplastic, and two of xenogeneic origin) were combined with PRF. After the incubation with osteoblasts for 24 h, cell viability, migration, and proliferation were assessed. Next, marker of proliferation, migration, and differentiation were evaluated on gene and protein levels in comparison to the …
Is it still important to be light in ski jumping?
2019
In ski jumping low body weight development resulted in some serious underweight problems and therefore the International Ski Federation (FIS) decided to solve the problem by relating maximum ski length to Body Mass Index (BMI) in 2004. The present study examined the current relationship between body weight, ski length and performance (jumping distance) in ski jumping. By adopting the BMI regulation to specifications for competition equipment, the FIS succeeded in stopping the alarming development of underweight problems in ski jumping. However, as the results of the present study show, the BMI regulation adopted by the FIS has reduced the advantage of being light, but despite the use of sho…
Determination of the LD50 with the chick embryo chorioallantoic membrane (CAM) assay as a promising alternative in nanotoxicological evaluation
2021
Toxicity tests in rodents are still considered a controversial topic concerning their ethical justifiability. The chick embryo chorioallantoic membrane (CAM) assay may offer a simple and inexpensive alternative. The CAM assay is easy to perform and has low bureaucratic hurdles. At the same time, the CAM assay allows the application of a broad variety of analytical methods in the field of nanotoxicological research. We evaluated the CAM assay as a methodology for the determination of nanotoxicity. Therefore we calculated the median lethal dose (LD50), performed in vivo microscopy and immunohistochemistry to identify organ-specific accumulation profiles, potential organ damage, and the kineti…
A novel pilot study of automatic identification of EMF radiation effect on brain using computer vision and machine learning
2020
Abstract Electromagnetic field (EMF) radiations from mobile phones and cell tower affect brain of humans and other organisms in many ways. Exposure to EMF could lead to neurological changes causing morphological or chemical changes in the brain and other internal organs. Cellular level analysis to measure and identify the effect of mobile radiations is an expensive and long process as it requires preparing the cell suspension for the analysis. This paper presents a novel pilot study to identify changes in brain morphology under EMF exposure considering drosophila melanogaster as a specimen. The brain is automatically segmented, obtaining microscopic images from which discriminatory geometri…
Inspired by nature: Fiber networks functionalized with tannic acid and condensed tannin-rich extracts of Norway spruce bark show antimicrobial effica…
2023
This study demonstrated the antibacterial and antiviral potential of condensed tannins and tannic acid when incorporated into fiber networks tested for functional material purposes. Condensed tannins were extracted from industrial bark of Norway spruce by using pressurized hot water extraction (PHWE), followed by purification of extracts by using XADHP7 treatment to obtain sugar-free extract. The chemical composition of the extracts was analyzed by using HPLC, GC‒MS and UHPLC after thiolytic degradation. The test matrices, i.e., lignocellulosic handsheets, were produced and impregnated with tannin-rich extracts, and tannic acid was used as a commercial reference. The antibacterial and antiv…
Ascending Aorta Resection and End-to-End Anastomosis: Redistribution of Wall Shear Stress Induced by a Bioprosthetic Heart Valve
2020
Although aortic resection and end-to-end anastomosis are applied to repair ascending aortic aneurysm, there is a lack of information on the late risk of post-operative complications, such as aortic dissection and aneurysmal re-dilatation. It is recognized that altered hemodynamic forces exerted on an aortic wall play an important role on dissection and aneurysm formation. We present a case in which the hemodynamic forces were investigated prior and after repair of an ascending aorta treated by resection with end-to-end anastomosis and a bioprosthetic heart valve. Post-operative wall shear stress was redistributed uniformly along the vessel circumference, and this may suggest a reduced risk …
Algorithms for the Automated Analysis of Age-Related Macular Degeneration Biomarkers on Optical Coherence Tomography: A Systematic Review
2017
PURPOSE To assess the quality of optical coherence tomography (OCT) grading algorithms for retinal biomarkers of age-related macular degeneration (AMD). METHODS Following a systematic review of the literature data on detection and quantification of AMD retinal biomarkers by available algorithms were extracted and descriptively synthesized. Algorithm quality was assessed using a modified version of the Quality Assessment of Diagnostic Accuracy Studies 2 checklist with a focus on accuracy against established reference standards and risk of bias. RESULTS Thirty five studies reporting computer-aided diagnosis (CAD) tools for qualitative analysis or algorithms for quantitative analysis were iden…
Resolving Bio-Nano Interactions of E.coli Bacteria-Dragonfly Wing Interface with Helium Ion and 3D-Structured Illumination Microscopy to Understand B…
2020
Obtaining a comprehensive understanding of the bactericidal mechanisms of natural nanotextured surfaces is crucial for the development of fabricated nanotextured surfaces with efficient bactericidal activity. However, the scale, nature, and speed of bacteria-nanotextured surface interactions make the characterization of the interaction a challenging task. There are currently several different opinions regarding the possible mechanisms by which bacterial membrane damage occurs upon interacting with nanotextured surfaces. Advanced imaging methods could clarify this by enabling visualization of the interaction. Charged particle microscopes can achieve the required nanoscale resolution but are …