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ACS Applied Materials & Interfaces Mar 2020The development of an electronic skin patch that can be used in underwater environments can be considered essential for fabricating long-term wearable devices and...
The development of an electronic skin patch that can be used in underwater environments can be considered essential for fabricating long-term wearable devices and biomedical applications. Herein, we report a stretchable conductive polymer composite (CPC) patch on which an octopus sucker-inspired structure is formed to conformally contact with biological skin that may be rough and wet. The patch is patterned with a hexagonal mesh structure for water and air permeability. The patch films are suited for a strain sensor or a stretchable electrode as their piezoresistive responses can be controlled by changing the concentration of conductive fillers to polymeric polyurethane. The CPC patch with a hexagonal mesh pattern (HMP) can be easily stretched for a strain sensor and is insensitive to tensile strain, making the patch suitable as a stretchable electrode. Furthermore, the octopus-like structures formed on the skeleton of the HMP allow the patch to maintain strong adhesion underwater by easily draining excess water trapped between the patch and skin. The sensor patch (<50 wt % carbon nanotubes (CNTs)) can sensitively detect the bending strain of a finger, and the electrode patch (50 wt % CNTs with addition of Ag flakes) can stably measure biosignals (e.g., electrocardiogram signals) under both dry and wet conditions owing to the octopus-like structure and HMP.
Topics: Air; Humans; Nanotubes, Carbon; Polymers; Polyurethanes; Tensile Strength; Water; Wearable Electronic Devices
PubMed: 32125136
DOI: 10.1021/acsami.9b23400 -
Journal of Computer Assisted Tomography 2008To assess the feasibility of volumetric and densitometric software to localize and quantify signs of regional air trapping after methacholine bronchoprovocations in...
OBJECTIVE
To assess the feasibility of volumetric and densitometric software to localize and quantify signs of regional air trapping after methacholine bronchoprovocations in asthma.
METHODS
Eight atopic subjects with mild-to-moderate asthma using short-acting beta2-agonists only, with hyperresponsiveness to methacholine, were evaluated. Low-dose baseline expiratory 16-slice multidetector computed tomography scans before and after a methacholine bronchoprovocation were acquired. MeVisPULMO3D software (Bremen, Germany) was applied to the scans, providing quantitative information on volume and density measures of the total lung and each lobe.
RESULTS
After methacholine, the expiratory scan showed a median (interquartile range) increase in volume of 534 mL (357-1279 mL), a decrease in lung density (mean and 15th percentile) of 52 Hounsfield Units (HU) (116-39 HU) and 34 HU (78-25 HU), respectively, and an increase in percentage low attenuation areas of 3% (2%-6%) for the total lung, with similar patterns in individual lung lobes. The right and left lower lung lobes showed the largest increases in air trapping, 211 mL (117-363 mL) and 229 mL (155-315 mL), respectively, versus a volume increase of 70 mL (20-249 mL), 26 mL (-16-92 mL), and 91 mL (-28-241 mL) for the right upper, middle, and left upper lobes, respectively. Volume changes in the lower lobes were associated with baseline forced expiratory flow between 25% and 75% of forced vital capacity, whereas low attenuation areas changes in the lower lobes were not.
CONCLUSIONS
This study suggests that multidetector computed tomography scans are able to localize and quantify regional air trapping in asthma after methacholine bronchoprovocations. Volumetric measurements of the lobes as compared to densitometric measurements are superior in detecting local air trapping in gravity-dependent areas of the lung.
Topics: Adult; Air; Asthma; Bronchoconstrictor Agents; Densitometry; Feasibility Studies; Female; Forced Expiratory Flow Rates; Functional Residual Capacity; Humans; Image Processing, Computer-Assisted; Lung; Male; Methacholine Chloride; Middle Aged; Observer Variation; Respiratory Function Tests; Software Validation; Spirometry; Tomography, X-Ray Computed; Vital Capacity
PubMed: 18664844
DOI: 10.1097/RCT.0b013e31815f2bb0 -
Aerospace Medicine Jul 1972
Topics: Adult; Air; Airway Obstruction; Diving; Humans; Immersion; Lung; Male; Naval Medicine; Plethysmography, Whole Body; Pulmonary Ventilation; Smoking; Spirometry; Vital Capacity
PubMed: 5055609
DOI: No ID Found -
Journal of Visualized Experiments : JoVE Feb 2017We demonstrate a method to trap a selected dielectric microparticle in air using radiation pressure from a single-beam gradient optical trap. Randomly scattered...
We demonstrate a method to trap a selected dielectric microparticle in air using radiation pressure from a single-beam gradient optical trap. Randomly scattered dielectric microparticles adhered to a glass substrate are momentarily detached using ultrasonic vibrations generated by a piezoelectric transducer (PZT). Then, the optical beam focused on a selected particle lifts it up to the optical trap while the vibrationally excited microparticles fall back to the substrate. A particle may be trapped at the nominal focus of the trapping beam or at a position above the focus (referred to here as the levitation position) where gravity provides the restoring force. After the measurement, the trapped particle can be placed at a desired position on the substrate in a controlled manner. In this protocol, an experimental procedure for selective optical trap loading in air is outlined. First, the experimental setup is briefly introduced. Second, the design and fabrication of a PZT holder and a sample enclosure are illustrated in detail. The optical trap loading of a selected microparticle is then demonstrated with step-by-step instructions including sample preparation, launching into the trap, and use of electrostatic force to excite particle motion in the trap and measure charge. Finally, we present recorded particle trajectories of Brownian and ballistic motions of a trapped microparticle in air. These trajectories can be used to measure stiffness or to verify optical alignment through time domain and frequency domain analysis. Selective trap loading enables optical tweezers to track a particle and its changes over repeated trap loadings in a reversible manner, thereby enabling studies of particle-surface interaction.
Topics: Air; Microfluidic Analytical Techniques; Nanoparticles; Optical Tweezers; Transducers
PubMed: 28190055
DOI: 10.3791/54862 -
Frontiers in Bioscience (Elite Edition) Jun 2013In modern life, technologies enabling detection of biological molecules at a low threshold, for health and ecological concerns, are in high demand. Directly... (Review)
Review
In modern life, technologies enabling detection of biological molecules at a low threshold, for health and ecological concerns, are in high demand. Directly interrogating the molecules is a promising direction to clarify the noisy response of conventional assays arising from simultaneous different reactions. Besides sophisticated biophysical instrument such as the atomic force microscope, this paper proposes silicon nanotweezers (SNT) as a new microsystem for molecular manipulation. SNT can trap molecules and sense their biomechanical and bioelectrical response in minute operations. In this review SNT characteristics are overviewed; their operation modes are illustrated by molecule and cell trapping, manipulation and characterization in air and in solution. As they are tiny and can be mass produced by highly parallel microsystem technology, SNT can be seen as a potential molecular and cellular probe for routine analysis and bio detection.
Topics: Air; Biomechanical Phenomena; Biosensing Techniques; DNA; Electricity; Gelatin; Silicon
PubMed: 23747911
DOI: 10.2741/e675 -
The Science of the Total Environment Jan 2021Nowadays, there is an important controversy about coronavirus air transmission. The aim of this study was to determine aerosol transmission from patients with...
Nowadays, there is an important controversy about coronavirus air transmission. The aim of this study was to determine aerosol transmission from patients with coronavirus infection using "COVID-19 traps" that included different untouched surfaces within them. 42 swab samples of 6 different surfaces placed in the rooms of 6 patients with a positive diagnostic of COVID-19 were analyzed with RT-PCR technique to evaluate the presence of the virus and its stability. Samples were collected at 24, 48 and 72 h. Patients were in an intensive care unit (ICU) and in a COVID-19 ward unit (CWU) at a Spanish referral hospital. None of the samples placed in the ICU unit were positive for COVID-19. However, two surfaces, placed in a CWU room with a patient that required the use of respiratory assistance were positive for coronavirus at 72 h. Surfaces could not be touched by patients or health workers, so viral spreading was unequivocally produced by air transmission. Thus, fomites should be considered as a possible mode of transmission of coronavirus and frequent disinfection of surfaces should be taken into account. Our results, although preliminary, point the importance of SARS-CoV-2 virus air transmission indoors and may shed some light in this debate.
Topics: Air; Betacoronavirus; COVID-19; Coronavirus Infections; Equipment Contamination; Fomites; Humans; Pandemics; Pilot Projects; Pneumonia, Viral; SARS-CoV-2
PubMed: 33182011
DOI: 10.1016/j.scitotenv.2020.142317 -
The European Respiratory Journal Aug 2013Cystic fibrosis (CF) is primarily characterised by bronchiectasis and trapped air on chest computed tomography (CT). The revised Cystic Fibrosis Questionnaire...
Cystic fibrosis (CF) is primarily characterised by bronchiectasis and trapped air on chest computed tomography (CT). The revised Cystic Fibrosis Questionnaire respiratory symptoms scale (CFQ-R RSS) measures health-related quality of life. To validate bronchiectasis, trapped air and CFQ-R RSS as outcome measures, we investigated correlations and predictive values for pulmonary exacerbations. CF patients (aged 6-20 years) underwent CT, CFQ-R RSS and 1-year follow-up. Bronchiectasis and trapped air were scored using the CF-CT scoring system. Correlation coefficients and backward multivariate modelling were used to identify predictors of pulmonary exacerbations. 40 children and 32 adolescents were included. CF-CT bronchiectasis (r = -0.38, p<0.001) and CF-CT trapped air (r = -0.35, p = 0.003) correlated with CFQ-R RSS. Pulmonary exacerbations were associated with: bronchiectasis (rate ratio 1.10, 95% CI 1.02-1.19; p = 0.009), trapped air (rate ratio 1.02, 95% CI 1.00-1.05; p = 0.034) and CFQ-R RSS (rate ratio 0.95, 95% CI 0.91-0.98; p = 0.002). The CFQ-R RSS was an independent predictor of pulmonary exacerbations (rate ratio 0.96, 95% CI 0.94-0.97; p<0.001). Bronchiectasis, trapped air and CFQ-R RSS were associated with pulmonary exacerbations. The CFQ-R RSS was an independent predictor. This study further validated bronchiectasis, trapped air and CFQ-R RSS as outcome measures in CF.
Topics: Adolescent; Air; Bronchiectasis; Child; Cystic Fibrosis; Female; Humans; Lung; Male; Multivariate Analysis; Mutation; Observer Variation; Quality of Life; Retrospective Studies; Surveys and Questionnaires; Tomography, X-Ray Computed; Treatment Outcome; Young Adult
PubMed: 23314900
DOI: 10.1183/09031936.00137612 -
Analytical Sciences : the International... 2016Near-infrared laser-induced temperature elevation in single aqueous ammonium sulfate droplets levitated in air were evaluated by means of laser trapping and Raman...
Near-infrared laser-induced temperature elevation in single aqueous ammonium sulfate droplets levitated in air were evaluated by means of laser trapping and Raman spectroscopy. Since the vapor pressure in an aqueous solution droplet should be thermodynamically in equilibrium with that of water in air, the equilibrium size of the droplet varies sensitively through evaporation/condensation of water in accordance with the temperature change of the droplet. In this study, we demonstrated that the changes in the size of an optically levitated aqueous ammonium sulfate droplet were induced by irradiation of a 1064-nm laser beam as a heat source under an optical microscope. Temperature elevation in the droplet was evaluated successfully by means of Raman spectroscopy, and the values determined were shown to be in good agreement with those by the theoretical calculations based on the absorption coefficient of water at 1064-nm and the thermal conductivity of air. To the best of our knowledge, this is the first experimental demonstration showing that the absorption coefficient evaluated from changes in the size of optically-trapped aqueous droplets is consistent with that of pure water.
PubMed: 27063715
DOI: 10.2116/analsci.32.425 -
European Radiology Oct 2015To suggest a simple method that can quantify air trapping from chest CT in children with graft-versus-host disease (GVHD)-related bronchiolitis obliterans (BO).
OBJECTIVE
To suggest a simple method that can quantify air trapping from chest CT in children with graft-versus-host disease (GVHD)-related bronchiolitis obliterans (BO).
METHODS
This institutional review board-approved retrospective study included eight GVHD-related BO patients (age, 6 - 17 years) who underwent both 31 CTs of variable settings and pulmonary function tests (PFT). The attenuation values of lung parenchyma in normal (An) and air trapping (Aa) areas were obtained. Individualized threshold [(An + Aa)/2] and fixed threshold of -950 HU were set for air trapping quantification. Spearman correlation analysis and generalized linear mixed models were used for statistical analysis.
RESULTS
The mean value of individualized threshold was -830.2 ± 48.3 HU. The mean air trapping lung volume percentage with individualized threshold and -950 HU were 45.4 ± 18.9% and 1.4 ± 1.9%, respectively. The air trapping lung volume percentage with individualized threshold showed a significant negative correlation with the PFT of FEV1/FVC% in all data (γ = -0.795, P < .001) and in the correction of repetition (γ = -0.837, P = .010).
CONCLUSIONS
We suggest a simple and individualized threshold attenuation setting method for air trapping quantification insusceptible to CT imaging protocols or respiratory phase control in children with GVHD-related BO.
KEY POINTS
• Simple and individualized threshold attenuation setting for air trapping quantification is possible. • Individualized threshold attenuation setting is insusceptible to CT imaging protocols or respiratory phase control. • CT air trapping quantification correlates with PFT of pulmonary obstruction.
Topics: Adolescent; Air; Bronchiolitis Obliterans; Child; Feasibility Studies; Female; Forced Expiratory Volume; Graft vs Host Disease; Humans; Lung; Male; Pilot Projects; Respiratory Function Tests; Retrospective Studies; Tomography, X-Ray Computed
PubMed: 25809743
DOI: 10.1007/s00330-015-3700-9 -
Journal of Chromatography. A Jul 2019The applicability of an aerial drone as a carrier for new passive and active miniaturized air sampling systems, including solid phase microextration Arrow (SPME Arrow)...
The applicability of an aerial drone as a carrier for new passive and active miniaturized air sampling systems, including solid phase microextration Arrow (SPME Arrow) and in-tube extraction (ITEX), was studied in this research. Thermal desorption, gas chromatography and mass spectrometry were used for the determination of volatile organic compounds (VOCs) collected by the sampling systems. The direct comparison of the profiles of VOCs, simultaneously sampled in air by SPME Arrow system including four different coatings, allowed the elucidation of their adsorption selectivity. A more complex experimental design, involving 20 samples (10 flights) and non-supervised pattern recognition techniques, was needed for the clarification of the same sampling parameters in the case of five ITEX sorbent materials. In addition, ITEX sampling accessories, such as particle, water and ozone traps, were evaluated by comparing the results obtained for air samples simultaneously collected by two ITEX systems, packed with the same sorbent and furnished or not with sampling accessories. The effect of the aerial drone horizontal displacement (HD) on the sampling efficiency was clear in the case of SPME Arrow. The number of detected compounds and their relative peak area values (RPA) revealed a clear increase (4 and 43%, respectively) in comparison with samples collected without drone HD. However, just minor differences were observed in the case of ITEX (2 compounds and 9% of the ∑RPA). In addition, the system was able to provide almost simultaneous passive (SPME Arrow) and active (ITEX) samplings at different altitudes (5 and 50 m), being a good tool for low cost vertical profiling studies (∑RPA decreased over 35% for the samples collected at 50 m). Finally, the successful simultaneous air sampling by SPME Arrow and ITEX systems in two difficult access places, such as boreal forest and wetlands, was demonstrated, resulting in 21 and 31 detected compounds in forest and wetlands by SPME Arrow, and 27 and 39 compounds by ITEX.
Topics: Adsorption; Air; Environmental Monitoring; Gas Chromatography-Mass Spectrometry; Miniaturization; Solid Phase Microextraction; Volatile Organic Compounds
PubMed: 31030954
DOI: 10.1016/j.chroma.2019.04.009