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1.
J Biomed Inform ; 131: 104116, 2022 07.
Article in English | MEDLINE | ID: mdl-35690351

ABSTRACT

Falls are one of the most costly population health issues. Screening of older adults for fall risks can allow for earlier interventions and ultimately lead to better outcomes and reduced public health spending. This work proposes a solution to limitations in existing fall screening techniques by utilizing a hip-based accelerometer worn in free-living conditions. The work proposes techniques to extract fall risk features from periods of free-living ambulatory activity. Analysis of the proposed techniques is conducted and compared with existing screening methods using Functional Tests and Lab-based Gait Analysis. 1705 Older Adults from Umea (Sweden) were assessed. Data consisted of 1 Week of hip worn accelerometer data, gait measurements and performance metrics for 3 functional tests. Retrospective and Prospective fall data were also recorded based on the incidence of falls occurring 12 months before and after the study commencing respectively. Machine learning based experiments show accelerometer based measures perform best when predicting falls. Prospective falls had a sensitivity and specificity of 0.61 and 0.66 respectively while retrospective falls had a sensitivity and specificity of 0.61 and 0.68 respectively.


Subject(s)
Accelerometry , Gait , Prospective Studies , Retrospective Studies
2.
Ultrason Sonochem ; 73: 105483, 2021 May.
Article in English | MEDLINE | ID: mdl-33571939

ABSTRACT

Among the different properties of the hydrophobic semiconductor surfaces, self-cleaning promoted by solar illumination is probably one of the most attractive from the technological point of view. The use of sonochemistry for nanomaterials' synthesis has been recently employed for the associated shorter reaction times and efficient route for control over crystal growth and the management of the resulting material's photocatalytic properties. Moreover, the sol-gel method coupled to sonochemistry modifies the chemical environment, with reactive species such as •OH and H2O2, which yield a homogeneous synthesis. Therefore, in the following investigation, the sol-gel method was coupled to sonochemistry to synthesize a SiO2@TiO2 composite, for which the sonochemical amplitude of irradiation was varied to determine its effect on the morphology and mechanical and self-cleaning properties. SEM and AFM characterized the samples of SiO2@TiO2 composite, and while the micrographs indicate that a high ultrasonic energy results in an amorphous SiO2@TiO2 composite with a low rugosity, which was affected in the determination of the contact angle on the surface. On the other hand, FTIR analysis suggests a significant change in both SiO2-SiO and SiO2-TiO2 chemical bonds with changes in vibrations and frequency, corroborating an important influence of the sonochemical energy contribution to the hydrolysis process. Raman spectroscopy confirms the presence of an amorphous phase of silicon dioxide; however, the vibrations of TiO2 were not visible. The evaluation of hydrophobic and self-cleaning properties shows a maximum of ultrasonic energy needed to improve the contact angle and rhodamine B (RhB) removal.

3.
J Nanosci Nanotechnol ; 17(1): 711-19, 2017 Jan.
Article in English | MEDLINE | ID: mdl-29633809

ABSTRACT

Currently pathogen microorganisms, presents in wastewater, are more resistant to conventional disinfection process, due to its constant change induced for the antibiotic for human diseases. One of the new options for the pathogen microorganisms is the heterogeneous photocatalysis, which has been used for remove microorganism, but never in real wastewater effluent. This paper shown the synthesis of Ag­TiO2 nanoparticles, its physical characterization was carried out by TEM, SEM, S-BET, XPS and band gap measurement by UV-vis spectroscopy showing that Ag­TiO2 are spherical particles with sizes around 50 nm with 1 and 10 %w of Ag, and a significant decrease in the band gap. The disinfection system was illuminated using the solar radiation of a spring day at Querétaro, Mexico, in lapses from 11:00 am to 03:00 pm; the microbiological tests were performed according to the Official Mexican Norm (NOM-003-SEMARNAT-1996), the results shows that after 3 hours of solar photocatalysis disinfection process the material 1 %w Ag­TiO2 at 0.2 gL⁻¹, removes the fecal and total coliform microorganisms from effluent, leaving Enterobacter, Escherichia, Citrobacter, Salmonella and Klebsiella microorganisms alive due to its capability of reactivation.

4.
Water Res ; 43(14): 3593-603, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19560182

ABSTRACT

Electrochemical advanced oxidation processes (EAOPs) are used to chemically burn non biodegradable complex organic compounds that are present in polluted effluents. A common approach involves the use of TiO2 semiconductor substrates as either photocatalytic or photoelectrocatalytic materials in reactors that produce a powerful oxidant (hydroxyl radical) that reacts with pollutant species. In this context, the purpose of this work is to develop a new TiO2 based photoanode using an optic fiber support. The novel arrangement of a TiO2 layer positioned on top of a surface modified optical fiber substrate, allowed the construction of a photoelectrochemical reactor that works on the basis of an internally illuminated approach. In this way, a semi-conductive optical fiber modified surface was prepared using 30 microm thickness SnO2:Sb films on which the photoactive TiO2 layer was electrophoretically deposited. UV light transmission experiments were conducted to evaluate the transmittance along the optical fiber covered with SnO2:Sb and TiO2 showing that 43% of UV light reached the optical fiber tip. With different illumination configurations (external or internal), it was possible to get an increase in the amount of photo-generated H(2)O(2) close to 50% as compared to different types of TiO2 films. Finally, the electro-Fenton photoelectrocatalytic Oxidation process studied in this work was able to achieve total color removal of Azo orange II dye (15 mg L(-1)) and a 57% removal of total organic carbon (TOC) within 60 min of degradation time.


Subject(s)
Electrochemical Techniques/instrumentation , Optical Fibers , Photochemical Processes , Titanium/chemistry , Waste Disposal, Fluid , Water Purification , Antimony/chemistry , Carbon/isolation & purification , Catalysis , Color , Electrodes , Hydrogen Peroxide/chemistry , Microscopy, Electron, Scanning , Oxidation-Reduction , Spectrophotometry, Ultraviolet
5.
J Food Sci ; 73(6): C488-93, 2008 Aug.
Article in English | MEDLINE | ID: mdl-19241539

ABSTRACT

Water-soluble extracts from Mexican oregano (Lippia graveolens) were incorporated into soy protein isolate (SPI) films. Water vapor permeability, mechanical properties, and antioxidant ability were evaluated. All the extracts were capable of scavenging DPPH radicals in a concentration-dependent fashion; the IC50 values were obtained. Oregano extracts were incorporated into SPI films plasticized with sorbitol, glycerol, and glycerol-sorbitol 1:1. The addition of the extracts resulted in an increase in the water vapor permeability values and provided a dark reddish film appearance. Changes in tensile strength as well as elongation values were observed. The oregano SPI films exhibited antioxidant properties in a concentration-dependent fashion.


Subject(s)
Biofilms/drug effects , Food Packaging/methods , Origanum/chemistry , Soybean Proteins/chemistry , Water/metabolism , Antioxidants/analysis , Antioxidants/metabolism , Free Radical Scavengers , Permeability , Plant Extracts/chemistry , Plasticizers/chemistry , Solubility , Soybean Proteins/isolation & purification , Steam , Tensile Strength
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