68 research outputs found
Mobile phone sensors in health applications
One of the most important device in our lives is a mobile phone. For now, it is a powerful computing platform equipped with various sensors. Embedded sensors can be used in multiple domains, such as environmental monitoring, social networks, safety and also healthcare. In this paper we survey the main use cases of mobile phone sensors in mobile healthcare. We classify the proposed mHealth sensing applications according to sensor types they use and discuss the main advantages provided by these applications
Comparison of the Influence of "Solvent/Non-Solvent” Treatment for the Attachment of Signal Molecules on the Structure of Electrospun PCL and PLLA Biodegradable Scaffolds
Electrospun biodegradable scaffolds (matrixes) made of poly([epsilon]-caprolactone) (PCL) and poly(L-lactic acid) (PLLA) are three-dimensional fibrous structures that are commonly used in regenerative medicine and drug delivery systems. Modification of such structures allows manipulating with biological and immune response. Previously, our team suggested a number of surface modification strategies for thin films made of PLLA. One of the proposed strategies are based on treatment of the material with “solvent/non-solvent” mixture that allows absorbing biologically active molecules or linkers on the surface of the sample. The aim of this work was to compare the influence of “solvent/non-solvent” treatment on the structure and crystallinity of the elecrospun biodegradable PCL and PLLA scaffolds. For that purpose, original PCL and PLLA scaffolds were treated with mixture of toluene and ethanol in different proportions. Morphology of the obtained samples was studied using scanning electron microscopy. It was shown that “solvent/non-solvent” treatment doesn’t lead to changes in scaffolds morphology such as gluing or cutting of the matrix fibers. By means of X-ray diffraction analysis it was shown that treatment of the samples with selected mixtures doesn’t change material crystallinity. Thus, it was demonstrated that proposed composition of the “solvent/nonsolvent” mixture can be used for the modification of electrospun PCL and PLLA scaffolds
Magnetron plasma mediated immobilization of hyaluronic acid for the development of functional double-sided biodegradable vascular graft
The clinical need for vascular grafts is associated with cardiovascular
diseases frequently leading to fatal outcomes. Artificial vessels based on
bioresorbable polymers can replace the damaged vascular tissue or create a
bypass path for blood flow while stimulating regeneration of a blood vessel in
situ. However, the problem of proper conditions for the cells to grow on the
vascular graft from the adventitia while maintaining its mechanical integrity
of the luminal surface remains a challenge. In this work, we propose a
two-stage technology for processing electrospun vascular graft from
polycaprolactone, which consists of plasma treatment and subsequent
immobilization of hyaluronic acid on its surface producing thin double-sided
graft with one hydrophilic and one hydrophobic side. Plasma modification
activates the polymer surfaces and produces a thin layer for linker-free
immobilization of bioactive molecules, thereby producing materials with unique
properties. The proposed modification does not affect the morphology or
mechanical properties of the graft and improves cell adhesion. The proposed
approach can potentially be used for various biodegradable polymers such as
polylactic acid, polyglycolide, and their copolymers and blends, with a
hydrophilic inner surface and a hydrophobic outer surface
Pulsed Vacuum Arc Deposition of Nitrogen-Doped Diamond-like Coatings for Long-Term Hydrophilicity of Electrospun Poly(ε-caprolactone) Scaffolds
The surface hydrophobicity of poly(ε-caprolactone) electrospun scaffolds prevents their interactions with cells and tissue integration. Although plasma treatment of scaffolds enhances their hydrophilicity, this effect is temporary, and the hydrophobicity of the scaffolds is restored in about 30 days. In this communication, we report a method for hydrophilization of poly(ε-caprolactone) electrospun scaffolds for more than 6 months. To that end, diamond-like coating was deposited on the surface of the scaffolds in a nitrogen atmosphere using pulsed vacuum arc deposition with sputtering of graphite target. This approach allows for a single-side hydrophilization of the scaffold (water contact angle of 22 ± 3° vs. 126 ± 2° for pristine PCL scaffold) and preserves its structure. With increased nitrogen pressure in the chamber, sp3-hybridized carbon content decreased twice (sp2/sp3 ratio decreased from 1.06 to 0.52), which demonstrates the possibility of tailoring the content of carbon in sp2 and sp3 hybridization state. Nitrogen content in the deposited coatings was found at 16.1 ± 0.9 at.%. In vitro tests with fibroblast cell culture did not reveal any cytotoxic compounds in sample extracts
Potential of Core-Collapse Supernova Neutrino Detection at JUNO
JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve
Detection of the Diffuse Supernova Neutrino Background with JUNO
As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The dominant background is from the neutral-current (NC) interaction of atmospheric neutrinos with 12C nuclei, which surpasses the DSNB by more than one order of magnitude. We evaluated the systematic uncertainty of NC background from the spread of a variety of data-driven models and further developed a method to determine NC background within 15\% with {\it{in}} {\it{situ}} measurements after ten years of running. Besides, the NC-like backgrounds can be effectively suppressed by the intrinsic pulse-shape discrimination (PSD) capabilities of liquid scintillators. In this talk, I will present in detail the improvements on NC background uncertainty evaluation, PSD discriminator development, and finally, the potential of DSNB sensitivity in JUNO
Real-time Monitoring for the Next Core-Collapse Supernova in JUNO
Core-collapse supernova (CCSN) is one of the most energetic astrophysical
events in the Universe. The early and prompt detection of neutrinos before
(pre-SN) and during the SN burst is a unique opportunity to realize the
multi-messenger observation of the CCSN events. In this work, we describe the
monitoring concept and present the sensitivity of the system to the pre-SN and
SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is
a 20 kton liquid scintillator detector under construction in South China. The
real-time monitoring system is designed with both the prompt monitors on the
electronic board and online monitors at the data acquisition stage, in order to
ensure both the alert speed and alert coverage of progenitor stars. By assuming
a false alert rate of 1 per year, this monitoring system can be sensitive to
the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos
up to about 370 (360) kpc for a progenitor mass of 30 for the case
of normal (inverted) mass ordering. The pointing ability of the CCSN is
evaluated by using the accumulated event anisotropy of the inverse beta decay
interactions from pre-SN or SN neutrinos, which, along with the early alert,
can play important roles for the followup multi-messenger observations of the
next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure
Comparison of the Influence of “Solvent/Non-Solvent” Treatment for the Attachment of Signal Molecules on the Structure of Electrospun PCL and PLLA Biodegradable Scaffolds
Electrospun biodegradable scaffolds (matrixes) made of poly(ε-caprolactone) (PCL) and poly(L-lactic acid) (PLLA) are three-dimensional fibrous structures that are commonly used in regenerative medicine and drug delivery systems. Modification of such structures allows manipulating with biological and immune response. Previously, our team suggested a number of surface modification strategies for thin films made of PLLA. One of the proposed strategies are based on treatment of the material with “solvent/non-solvent” mixture that allows absorbing biologically active molecules or linkers on the surface of the sample. The aim of this work was to compare the influence of “solvent/non-solvent” treatment on the structure and crystallinity of the elecrospun biodegradable PCL and PLLA scaffolds. For that purpose, original PCL and PLLA scaffolds were treated with mixture of toluene and ethanol in different proportions. Morphology of the obtained samples was studied using scanning electron microscopy. It was shown that “solvent/non-solvent” treatment doesn’t lead to changes in scaffolds morphology such as gluing or cutting of the matrix fibers. By means of X-ray diffraction analysis it was shown that treatment of the samples with selected mixtures doesn’t change material crystallinity. Thus, it was demonstrated that proposed composition of the “solvent/nonsolvent” mixture can be used for the modification of electrospun PCL and PLLA scaffolds
Modification of PCL scaffolds by reactive magnetron sputtering: a possibility for modulating macrophage responses
Direct current (DC) reactive magnetron sputtering is as an efficient method for enhancing the biocompatibility of poly(ε-caprolactone) (PCL) scaffolds. However, the PCL chemical bonding state, the composition of the deposited coating, and their interaction with immune cells remain unknown. Herein, we demonstrated that the DC reactive magnetron sputtering of the titanium target in a nitrogen atmosphere leads to the formation of nitrogen-containing moieties and the titanium dioxide coating on the scaffold surface. We have provided the possible mechanism of PCL fragmentation and coating formation supported by XPS results and DFT calculations. Our preliminary biological studies suggest that DC reactive magnetron sputtering of the titanium target could be an effective tool to control macrophage functional responses toward PCL scaffolds as it allows to inhibit respiratory burst while retaining cell viability and scavenging activity
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