Search results for "Biomedical"
showing 10 items of 2328 documents
Dynamical learning of a photonics quantum-state engineering process
2021
Abstract. Experimental engineering of high-dimensional quantum states is a crucial task for several quantum information protocols. However, a high degree of precision in the characterization of the noisy experimental apparatus is required to apply existing quantum-state engineering protocols. This is often lacking in practical scenarios, affecting the quality of the engineered states. We implement, experimentally, an automated adaptive optimization protocol to engineer photonic orbital angular momentum (OAM) states. The protocol, given a target output state, performs an online estimation of the quality of the currently produced states, relying on output measurement statistics, and determine…
FPGA based digital lock-in amplifier for fNIRS systems
2018
Lock-In Amplifiers (LIA) represent a powerful technique helping to improve signals detectability when low signal to noise ratios are experienced. Continuous Wave functional Near Infrared Spectroscopy (CW-fNIRS) systems for e-health applications usually suffer of poor detection due to the presence of strong attenuations of the optical recovering path and therefore small signals are severely dipped in a high noise floor. In this work a digital LIA system, implemented on a Zynq® Field Programmable Gate Array (FPGA), has been designed and tested to verify the quality of the developed solution, when applied in fNIRS systems. Experimental results have shown the goodness of the proposed solutions.
Design and experimental validation of a magnetic device for stem cell culture.
2020
Cell culture of bone and tendon tissues requires mechanical stimulation of the cells in order to mimic their physiological state. In the present work, a device has been conceived and developed to generate a controlled magnetic field with a homogeneous gradient in the working space. The design requirement was to maximize the magnetic flux gradient, assuring a minimum magnetizing value in a 15 mm × 15 mm working area, which highly increases the normal operating range of this sort of devices. The objective is to use the machine for two types of biological tests: magnetic irradiation of biological samples and force generation on paramagnetic particles embedded in scaffolds for cell culture. The…
A procedure for slicing and characterizing soft heterogeneous and irregular-shaped tissue
2020
Abstract This paper presents a slicing technique useful to prepare precise and repeatable samples from organs which are irregularly shaped and highly heterogeneous for mechanical testing and advanced microscopy observation. The suggested technique does not seem to influence the internal microstructure and it is employed here for testing specimens cut from different region of the meniscal tissue. Fast Fourier Transform analysis is used to quantify characteristic features of the microstructure (collagen fibers orientation, pore size) after slicing prior mechanical testing. Uniaxial (relaxation) tests are performed on dog-bone meniscal samples. Stress relaxation testing results on samples cut …
Cold gas dynamic spray technology: A comprehensive review of processing conditions for various technological developments till to date
2018
Abstract Today, cold gas dynamic spray (CGDS) technology has thrived with considerable capabilities for manufacturing various technological depositions. The deposition conditions have been developed through many years and that have led to produce ample experimental data which is available in the literature. But, recent research and development activities also reveal innovative findings regarding various deposition conditions. This paper contains a review of experimental deposition procedures for the cold spray additive manufacturing. Details of processing conditions are reported and classified into various categories of baseline working conditions, specific processing including deposition o…
Boolean computation in plants using post-translational genetic control and a visual output signal
2018
[EN] Due to autotrophic growing capacity and extremely rich secondary metabolism, plants should be preferred targets of synthetic biology. However, developments in plants usually run below those in other taxonomic groups. In this work we engineered genetic circuits capable of logic YES, OR and AND Boolean computation in plant tissues with a visual output signal. The circuits, which are deployed by means of Agrobacterium tumefaciens, perform with the conditional activity of the MYB transcription factor Roseal from Antirrhinum majus inducing the accumulation of anthocyanins, plant endogenous pigments that are directly visible to the naked eye or accurately quantifiable by spectrophotometric a…
Does silica concentration and phytolith ultrastructure relate to phytolith hardness?
2017
Abstract Grasses are an important part of the forage of many herbivorous mammals and their phytoliths have long been regarded as the most important agent of tooth wear. Recent work has challenged this “paradigm” in finding evidence 1. of native phytoliths to be much softer then tooth enamel and 2. indicating, that phytolith hardness is highly variable, 3. prone to methodology and 4. not easy to be related to habitat conditions. We conduct controlled silica-cultivations measuring SiO2 content in the common forage grass Themeda triandra. Phytoliths are extracted natively, and nano-indentation values are measured. Phytolith hardness in Themeda triandra is found to be independent of silicate av…
The combined effect on initial glucose concentration and pH control strategies for acetone-butanol-ethanol (ABE) fermentation by Clostridium acetobut…
2021
Abstract The use and depletion of fossil fuels raised the interest in biofuels like biobutanol. Clostridium acetobutylicum DSM 792 is capable of producing biobutanol through ABE fermentation. Butanol production can be influenced by low sugar concentrations, like those obtained after hydrolysis of pre-treated lignocellulosic biomass. This study aimed to evaluate the influence of the initial glucose concentrations (33, 66 and 100 g L−1) and pH control strategies on biobutanol production and glucose consumption. Uncontrolled pH fermentation exhibited low butanol production due to either glucose exhaustion (33 g L−1) or the phenomenon of acid crash (66 and 100 g L−1), which was alleviated by th…
Dendritic cell metabolism: moving beyond in vitro-culture-generated paradigms
2021
Dendritic cells (DCs) are key orchestrators of immunity and tolerance. It has become evident that DC function can be influenced by cellular metabolic programs. However, conclusions from early metabolic studies using in vitro GM-CSF DC cultures fail to correlate with bona fide DC populations. Here, we discuss the existing paradigms in the DC metabolism field, focusing on the limitations of the models utilized. Furthermore, we introduce alternative models to generate DCs in vitro that better emulate DCs found in vivo. Finally, we highlight new techniques to evaluate DC metabolism at the single-cell level. The combination of these two strategies could help advance the DC metabolism field towar…
The antioxidant 2,3‐dichloro,5,8‐dihydroxy,1,4‐naphthoquinone inhibits acetyl‐cholinesterase activity and amyloid β 42 aggregation: A dual target the…
2020
Alzheimer's disease is characterized by amyloid β aggregation and cholinergic neurodegeneration. In the present study, pure DDN (2,3-dichloro-5,8-dihydroxy-1,4-naphthoquinone) was examined, for the first time, for its dual potential as inhibitor of acetylcholinesterase (AChE) and Aβ42 aggregation. Such investigation was encouraged by the in vitro high antioxidant potential of DDN. Indeed, it revealed interesting antioxidant activity with IC50 values of 9.8 and 4.3 µM for ABTS and reducing power, respectively. The ability of DDN to counteract Aβ42 aggregation was evaluated by thioflavine-T assay. Strong inhibition of Aβ42 aggregation of more than 90% at 25 µM was measured. Moreover, results …