Search results for "Biomedical engineering"
showing 10 items of 2020 documents
A High-Throughput Mechanical Activator for Cartilage Engineering Enables Rapid Screening of in vitro Response of Tissue Models to Physiological and S…
2021
Articular cartilage is crucially influenced by loading during development, health, and disease. However, our knowledge of the mechanical conditions that promote engineered cartilage maturation or tissue repair is still incomplete. Current in vitro models that allow precise control of the local mechanical environment have been dramatically limited by very low throughput, usually just a few specimens per experiment. To overcome this constraint, we have developed a new device for the high throughput compressive loading of tissue constructs: the High Throughput Mechanical Activator for Cartilage Engineering (HiT-MACE), which allows the mechanoactivation of 6 times more samples than current tech…
Migration of brain capillary endothelial cells inside poly (lactic acid) 3D scaffolds
2017
The brain capillary endothelial cells (BCECs) form the blood brain barrier (BBB) under the effects of the brain microenvironment. BCECs are sealed together by tight junctions (TJs) that are responsible for the barrier phenotype. In these junctions, molecules such as JAM (junctional adhesion molecules), occludin and claudins are present. Threedimensional scaffolds are used to grow cells in order to obtain in vitro engineered tissues. On the base of these considerations, the aim of this work was to understand whether the endothelial cells were able to grow and survive on a new three-dimensional structure. If yes, indeed, this system could be further enriched and used to set a three-dimensiona…
Tubular scaffold for vascular tissue engineering application
2010
A critical obstacle in tissue engineering is the inability to maintain large masses of living cells upon transfer from the in vitro culture conditions into the host in vivo. Capillaries, and the vascular system, are required to supply essential nutrients, including oxygen, remove waste products and provide a biochemical communication “highway”. Another goal in this research field is the possibility to tune the biodegradability of the scaffold. After implantation, the scaffold has to be gradually replaced by cells and extra cellular matrix and it is crucial that this replacement takes place with an appropriate dynamics. A premature degradation, in fact, could lead to a collapse of the struct…
The influence of sludge retention time on mixed culture microbial fuel cell start-ups
2017
Abstract In this work, the start-ups of air-cathode microbial fuel cells (MFCs) seeds with conventional activated sludge cultivated at different solid retention times (SRTs) are compared. A clear influence of the SRT of the inoculum was observed, corresponding to an SRT of 10 days to the higher current density exerted, about 0.2 A m −2 . This observation points out that, in this type of electrochemical device, it is recommended to use high SRT seeds. The work also points out that in order to promote an efficient start-up, it is not only necessary to use high SRT seeds, but also to feed a high COD concentration. When feeding 10,000 ppm COD and keeping SRT of 10 d differences of current densi…
Wearable Multisensor Ring-Shaped Probe for Assessing Stress and Blood Oxygenation: Design and Preliminary Measurements
2023
The increasing interest in innovative solutions for health and physiological monitoring has recently fostered the development of smaller biomedical devices. These devices are capable of recording an increasingly large number of biosignals simultaneously, while maximizing the user’s comfort. In this study, we have designed and realized a novel wearable multisensor ring-shaped probe that enables synchronous, real-time acquisition of photoplethysmographic (PPG) and galvanic skin response (GSR) signals. The device integrates both the PPG and GSR sensors onto a single probe that can be easily placed on the finger, thereby minimizing the device footprint and overall size. The system enables the e…
Blood Vessel Detection Algorithm for Tissue Engineering and Quantitative Histology.
2021
AbstractImmunohistochemistry for vascular network analysis plays a fundamental role in basic science, translational research and clinical practice. However, identifying vascularization in histological tissue images is time consuming and markedly depends on the operator’s experience. In this study, we present “blood vessel detection—BVD”, an automatic algorithm for quantitative analysis of blood vessels in immunohistochemical images. BVD is based on extraction and analysis of low-level image features and spatial filtering techniques, which do not require a training phase. BVD algorithm performance was comparatively evaluated on histological sections from three different in vivo experiments. …
Radial Basis Function Interpolation for Referenceless Thermometry Enhancement
2015
MRgFUS (Magnetic Resonance guided Focused UltraSound) is a new and non-invasive technique to treat different diseases in the oncology field, that uses Focused Ultrasound (FUS) to induce necrosis in the lesion. Temperature change measurements during ultrasound thermo-therapies can be performed through magnetic resonance monitoring by using Proton Resonance Frequency (PRF) thermometry. It measures the phase variation resulting from the temperature-dependent changes in resonance frequency by subtracting one phase baseline image from actual phase. Referenceless thermometry aims to re-duce artefacts caused by tissue motion and frequency drift, fitting the back-ground phase outside the heated reg…
uality Evaluation of “Tardivo di Ciaculli” Mandarins in Post-Harvest Processing on an Industrial Scale Using a Portable Vis/NIR Device
2016
Abstract. Vis/NIR technology is widely used today to quickly and non-destructively evaluate fruit and vegetable qualities, and many applications have been found since the 1990s. However, no industrial-scale applications can further consolidate the use of non-destructive techniques in post-harvest processing. This study aims to test the possibility of applying vis/NIR technology in a modern citrus-processing plant to assess the damage that the fruits eventually suffer when they are processed on an industrial scale and the evolution of their key quality parameters in a period of 10 days after harvest. The spectral acquisitions were performed using a portable vis/NIR device, which operated in …
Red Cell Interactions with the Microcirculation
1976
We have measured RBC velocity profiles for mammalian arterioles and venules from high-speed cinematographic motion pictures. Measurements were made at 320× and 400× optical magnification over an averaging time period of 10 ms. In vivo profiles are uniformly nonsymmetrical, the RBCs exhibit rotation, and they frequently deviate sidewise from the overall axial direction of motion. In general, this is more pronounced on the venous side. Since all of the profiles are time variant and the average values are synchronous with the midstream velocity, individual RBC velocities will vary about the average. Profiles become more blunted in vessels with smaller diameters. In vessels below 16 μm diameter…
Electromagnetically generated extracorporeal shock waves for gallstone lithotripsy: in vitro experiments and clinical relevance.
1989
. First generation shock wave sources have been proved to disintegrate gallstones effectively, but they require the immersion of the patient's body in a tank of water. A recently developed second generation shock wave source (Siemens-Lithostar, Erlangen, FRG) generates shock waves electromagnetically. It presents several novel features. In particular the waterbath can be omitted and due to lower shock wave pressure general anaesthesia is not required. In vitro studies showed that 36 out of 38 gallstones (11–30 mm in diameter) could be disintegrated. Two concrements resisting lithotripsy were pure white cholesterol stones. Independent of shape, size, and composition (cholesterol or pigment) …