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1.
Sensors (Basel) ; 23(4)2023 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-36850558

RESUMEN

A Tungsten-Halogen (TH) lamp is the most popular light source in NIR spectroscopy and hyperspectral imaging, which requires a warm-up to reach very high temperatures of up to 250 °C and take a long time for radiation stabilization. Consequently, it has a large enough volume to enable heat dissipation to prevent the thermal runaway of the electric circuit and turn out its power efficiency very low. These are major barriers for miniaturizing spectral systems and hyperspectral imaging devices. However, TH lamps can be replaced by pc-NIR LEDs in order to avoid high temperature and large volume. We compared the spectral emission of the available commercial pc-NIR LEDs under the same condition. As a replacement for the TH lamp, the VIS + NIR LED module was developed to combine a warm-white LED and pc-NIR LEDs. In order to feature out the availability of the VIS + NIR LED module against the TH lamp, they were used as the light source for evaluating the Soluble Solid Content (SSC) of an apple through VIS-NIR spectroscopy. The results show a remarkable feasibility in the performance of the partial least square (PLS) model using the VIS + NIR LED module; during PLS calibration, the correlation coefficient (R) values are 0.664 and 0.701, and the Mean Square Error (MSE) values are 0.681 and 0.602 for the TH lamp and VIS + NIR LED module, respectively. In VIS-NIR spectroscopy, this study indicates that the TH lamp could be replaceable with a warm-white LED and pc-NIR LEDs.

2.
Harmful Algae ; 122: 102371, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36754457

RESUMEN

To understand the co-variance between common free-living bacteria and Cochlodinium polykrikoides harmful algal blooms (HABs) and their metabolic functions, we investigated 110 sampling sites in the Southern Sea of South Korea. These sampling sites were divided into three groups based on environmental factors and phytoplankton data with a similarity of 85% using non-metric multidimensional scaling. One group represented high-severity C. polykrikoides blooms, while the other two represented low-severity or no blooms. In high-severity HABs, inorganic phosphorous and dissolved organic carbon concentrations were strongly correlated with C. polykrikoides density (p < 0.01). This may reflect the changes in biochemical cycling due to inorganic and organic substrates released by HAB cells (or by cell destruction). Furthermore, 88 common bacterial operational taxonomic units (OTUs, with mean relative abundance > 1%) were identified. These included Gammaproteobacteria (36 OTUs), Flavobacteriia (24), Alphaproteobacteria (18), and other taxa (11). When C. polykrikoides blooms intensified, the relative abundances of Gammaproteobacteria also increased. OTU #030 (Flavicella sp., Flavobacteria, 96%) was positively correlated with C. polykrikoides abundance (r = 0.77, p < 0.001). Functional analysis based on the dominant bacterial OTUs revealed that chemoheterotrophy-related functions were more common in high-severity sites of HABs than in other groups. Therefore, the occurrence of HABs highlighted their interactions with bacteria and affected the bacterial community structure and metabolic functions.


Asunto(s)
Dinoflagelados , Floraciones de Algas Nocivas , Bacterias , Fitoplancton , República de Corea
3.
Ultrason Sonochem ; 83: 105933, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35114551

RESUMEN

In this study, the impacts of different ultrasonic treatments on TiO2 particles were determined and they were used to manufacture the photoelectrodes of a dye-sensitized solar cell (DSSC). Two methods were used to prepare TiO2 particles directly sonicated by an ultrasonic horn, and TiO2 treated indirectly by an ultrasonic cleaner. TEM, XPS analysis was confirmed that cavitation bubbles generated during ultrasonication resulted in defects on the surface of TiO2 particles, and the defect induced surface activation. To understand the effect of TiO2 surface activation on energy conversion efficiency of DSSC, ultrasonic horn DSSC and ultrasonic cleaner DSSC were prepared. The UV-vis analysis exhibited that the ultrasonic horn DSSC possessed higher dye adsorption when compared to the ultrasonic cleaner DSSC, and the EIS analysis confirmed that the electron mobility was greatly increased in the ultrasonic horn DSSC. The energy conversion efficiency of the ultrasonic horn DSSC was measured to be 3.35%, which is about 45% increase in comparison to that of the non-ultrasonic treated DSSC (2.35%). In addition to this regard, recombination resistance of ultrasonic horn DSSC was calculated to be 450 Ω·cm2, increasing more than two times compared to the non-ultrasonic treated DSSC (200 Ω·cm2). Taken together, these ultrasonic treatments significantly improved the energy conversion efficiency of DSSC, which was not tried in DSSC-related research, and might lead us to develop more efficient practical route in the manufacturing of DSSC.

4.
Sensors (Basel) ; 21(11)2021 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-34070613

RESUMEN

The development of a 3D-Printed Load Cell (PLC) was studied using a nanocarbon composite strain sensor (NCSS) and a 3D printing process. The miniature load cell was fabricated using a low-cost LCD-based 3D printer with UV resin. The NCSS composed of 0.5 wt% MWCNT/epoxy was used to create the flexure of PLC. PLC performance was evaluated under a rated load range; its output was equal to the common value of 2 mV/V. The performance was also evaluated after a calibration in terms of non-linearity, repeatability, and hysteresis, with final results of 2.12%, 1.60%, and 4.42%, respectively. Creep and creep recovery were found to be 1.68 (%FS) and 4.16 (%FS). The relative inferiorities of PLC seem to originate from the inherent hyper-elastic characteristics of polymer sensors. The 3D PLC developed may be a promising solution for the OEM/design-in load cell market and may also result in the development of a novel 3D-printed sensor.

5.
Sensors (Basel) ; 21(6)2021 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-33801103

RESUMEN

The array invariant technique has been recently proposed for passive source localization in the ocean. It has successfully estimated the source-receiver horizontal range in multipath-dominant shallow-water waveguides. However, it requires a relatively large-scale hydrophone array. This study proposes an array invariant method that uses acoustic intensity, which is a vector quantity that has the same direction as the sound wave propagating through a water medium. This method can be used to estimate not only the source-receiver horizontal range, but also the azimuth to an acoustic source. The feasibility of using a vector quantity for the array invariant method is examined through a simulation and an acoustic experiment in which particle velocity signals are obtained using a finite difference approximation of the pressure signals at two adjacent points. The source localization results estimated using acoustic intensity are compared with those obtained from beamforming of the acoustic signals acquired by the vertical line array.

6.
Sensors (Basel) ; 19(15)2019 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-31357411

RESUMEN

Reflection loss at the water-castor oil interface as a function of temperature was measured in a direction normal to the interface using a 200-kHz acoustic signal. The acoustic impedance of water increases with temperature, whereas that of castor oil decreases. The measured reflection losses varied from 30 to 65 dB, and a sharp rising peak in reflection loss was observed at the temperature at which the acoustic impedance of water became equal to that of castor oil. This temperature is called the temperature of intromission in this paper. These measurements were compared with the model predictions based on a Rayleigh-reflection model using the measured sound speeds of both fluids. The sound speeds in water and castor oil as functions of temperature are the input parameters of the Rayleigh-reflection model, and were measured directly using an arrival time difference method in the temperature range of 5 to 30 °C. The comparison results imply that temperature is an important factor affecting the reflection at the interface separating the two fluids.

7.
Radiat Prot Dosimetry ; 175(3): 297-303, 2017 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-27885084

RESUMEN

A new treatment facility for heavy ion therapy since 2010 was constructed. In the broad beam, a range shifter, ridge filter and multi leaf collimator (MLC) for the generation of the spread-out Bragg peak is used. In this case, secondary neutrons produced by the interactions of the ion field with beam-modifying devices (e.g. double-scattering system, beam shaping collimators and range compensators) are very important for patient safety. Therefore, these components must be carefully examined in the context of secondary neutron yield and associated secondary cancer risk. In this article, Monte Carlo simulation has been carried out with the FLUktuierende KAskade particle transport code, the fluence and distribution of neutron generation and the neutron dose equivalent from the broad beam components are compared using carbon and proton beams. As a result, it is confirmed that the yield of neutron production using a carbon beam from all components of the broad beam was higher than using a proton beam. The ambient dose by neutrons per heavy ion and proton ion from the MLC surface was 0.12-0.18 and 0.0067-0.0087 pSv, respectively, which shows that heavy ions generate more neutrons than protons. However, ambient dose per treatment 2 Gy, which means physical dose during treatment by ion beam, is higher than carbon beam because proton therapy needs more beam flux to make 2-Gy prescription dose. Therefore, the neutron production from the MLC, which is closed to the patient, is a very important parameter for patient safety.


Asunto(s)
Método de Montecarlo , Neutrones , Dosificación Radioterapéutica , Humanos , Protones , Radioterapia Conformacional
8.
J Sci Food Agric ; 96(11): 3723-30, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26676481

RESUMEN

BACKGROUND: The aim of this study was to elucidate the changes in microbial community and biochemical and physiological properties of traditional Muju black raspberry (Robus coreanus Miquel) vinegar (TMBV) during fermentation by culture-independent methods. RESULTS: During vinegar fermentation, ethanol produced up to 120 g L(-1) until day 35, with continuously increasing yeast concentration to a total of log 7.6 CFU mL(-1) . After day 35, acetic acid bacteria (AAB) concentrations rose to log 5.8 CFU mL(-1) until day 144. Denaturing gradient gel electrophoresis analysis showed that Saccharomyces cerevisiae was detected until day 87 of the fermentation, at which point Acetobacter pasteurianus gradually took over as the dominant species. Total sugar was reduced to 6.6 °Brix and total acidity produced up to 44 g L(-1) . CONCLUSION: In this study, we established the physicochemical analysis and growth dynamics of yeast and AAB during alcoholic and acetic acid fermentation of black raspberry by a traditional method. Overall, S. cerevisiae and A. pasteurianus species appeared to dominate the TMBV fermentation. In conclusion, this study demonstrated a suitable fermentation system for TMBV by the static surface method. © 2015 Society of Chemical Industry.


Asunto(s)
Ácido Acético , Bacterias , Fermentación , Microbiología de Alimentos , Frutas/microbiología , Rubus , Saccharomyces cerevisiae , Acetobacter/crecimiento & desarrollo , Acetobacter/metabolismo , Ácidos/metabolismo , Bacterias/crecimiento & desarrollo , Bacterias/metabolismo , Metabolismo de los Hidratos de Carbono , Electroforesis en Gel de Gradiente Desnaturalizante , Etanol/metabolismo , Frutas/metabolismo , Humanos , Saccharomyces cerevisiae/crecimiento & desarrollo , Saccharomyces cerevisiae/metabolismo
9.
Australas Phys Eng Sci Med ; 37(4): 635-44, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25154880

RESUMEN

Conventional laser accelerated proton beam has broad energy spectra. It is not suitable for clinical use directly, so it is necessary for employing energy selection system. However, in the conventional laser accelerated proton system, the intensity of the proton beams in the low energy regime is higher than that in the high energy regime. Thus, to generate spread-out-Bragg peak (SOBP), stronger weighting value to the higher energy proton beams is needed and weaker weighting value to the lower energy proton beams is needed, which results in the wide range of weighting values. The purpose of this research is to investigate a method for efficient generating of the SOBP with varying magnetic field in the energy selection system using a carbon-proton mixture target. Energy spectrum of the laser accelerated proton beams was acquired using Particle-In-Cell simulations. The Geant4 Monte Carlo simulation toolkit was implemented for energy selection, particle transportation, and dosimetric property measurement. The energy selection collimator hole size of the energy selection system was changed from 1 to 5 mm in order to investigate the effect of hole size on the dosimetric properties for Bragg peak and SOBP. To generate SOBP, magnetic field in the energy selection system was changed during beam irradiation with each beam weighting factor. In this study, our results suggest that carbon-proton mixture target based laser accelerated proton beams can generate quasi-monoenergetic energy distribution and result in the efficient generation of SOBP. A further research is needed to optimize SOBP according to each range and modulated width using an optimized weighting algorithm.


Asunto(s)
Carbono/efectos de la radiación , Rayos Láser , Modelos Estadísticos , Radiometría/métodos , Planificación de la Radioterapia Asistida por Computador/métodos , Radioterapia de Alta Energía/métodos , Algoritmos , Simulación por Computador , Humanos , Método de Montecarlo , Terapia de Protones , Dosificación Radioterapéutica
10.
J Transl Med ; 11: 196, 2013 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-23978163

RESUMEN

BACKGROUND: Autism is a pervasive neurodevelopmental disorder. At present there are no defined mechanisms of pathogenesis and therapy is mostly limited to behavioral interventions. Stem cell transplantation may offer a unique treatment strategy for autism due to immune and neural dysregulation observed in this disease. This non-randomized, open-label, single center phase I/II trial investigated the safety and efficacy of combined transplantation of human cord blood mononuclear cells (CBMNCs) and umbilical cord-derived mesenchymal stem cells (UCMSCs) in treating children with autism. METHODS: 37 subjects diagnosed with autism were enrolled into this study and divided into three groups: CBMNC group (14 subjects, received CBMNC transplantation and rehabilitation therapy), Combination group (9 subjects, received both CBMNC and UCMSC transplantation and rehabilitation therapy), and Control group (14 subjects, received only rehabilitation therapy). Transplantations included four stem cell infusions through intravenous and intrathecal injections once a week. Treatment safety was evaluated with laboratory examinations and clinical assessment of adverse effects. The Childhood Autism Rating Scale (CARS), Clinical Global Impression (CGI) scale and Aberrant Behavior Checklist (ABC) were adopted to assess the therapeutic efficacy at baseline (pre-treatment) and following treatment. RESULTS: There were no significant safety issues related to the treatment and no observed severe adverse effects. Statistically significant differences were shown on CARS, ABC scores and CGI evaluation in the two treatment groups compared to the control at 24 weeks post-treatment (p < 0.05). CONCLUSIONS: Transplantation of CBMNCs demonstrated efficacy compared to the control group; however, the combination of CBMNCs and UCMSCs showed larger therapeutic effects than the CBMNC transplantation alone. There were no safety issues noted during infusion and the whole monitoring period. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01343511, Title "Safety and Efficacy of Stem Cell Therapy in Patients with Autism".


Asunto(s)
Trastorno Autístico/terapia , Trasplante de Células Madre de Sangre del Cordón Umbilical , Leucocitos Mononucleares/trasplante , Trasplante de Células Madre Mesenquimatosas , Cordón Umbilical/citología , Trastorno Autístico/sangre , Niño , Preescolar , Femenino , Humanos , Masculino , Trasplante de Células Madre Mesenquimatosas/efectos adversos , Resultado del Tratamiento
11.
J Clin Sleep Med ; 9(4): 345-51, 2013 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-23585750

RESUMEN

STUDY OBJECTIVES: The objective was to study the effects on noninvasive ventilation on sleep outcomes in patient with ALS, specifically oxygenation and overall sleep quality. METHODS: Patients with ALS who met criteria for initiation of NIV were studied with a series of 2 home PSG studies, one without NIV and a follow-up study while using NIV. Primary outcome was a change in the maximum overnight oxygen saturation; secondary outcomes included change in mean overnight oxygen saturation, apnea and hypopnea indexes, sleep latency, sleep efficiency, sleep arousals, and sleep architecture. RESULTS: A total of 94 patients with ALS were screened for eligibility; 15 were enrolled; and 12 completed study procedures. Maximum overnight oxygen saturation improved by 7.0% (p = 0.01) and by 6.7% during REM sleep (p = 0.02) with NIV. Time spent below 90% oxygen saturation was also significant-ly better with NIV (30% vs 19%, p < 0.01), and there was trend for improvement in mean overnight saturation (1.5%, p = 0.06). Apnea index (3.7 to 0.7), hypopnea index (6.2 to 5.7), and apnea hypopnea index (9.8 to 6.3) did not significantly improve after introducing NIV. NIV had no effect on sleep efficiency (mean change 10%), arousal index (7 to 12), or sleep stage distribution (Friedman chi-squared = 0.40). CONCLUSIONS: NIV improved oxygenation but showed no significant effects on sleep efficiency, sleep arousals, restful sleep, or sleep architecture. The net impact of these changes for patients deserves further study in a larger group of ALS patients.


Asunto(s)
Esclerosis Amiotrófica Lateral/complicaciones , Ventilación no Invasiva/métodos , Trastornos del Sueño-Vigilia/complicaciones , Trastornos del Sueño-Vigilia/terapia , Anciano , Femenino , Estudios de Seguimiento , Humanos , Masculino , Proyectos Piloto , Polisomnografía/métodos , Resultado del Tratamiento
12.
Med Phys ; 40(2): 021704, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23387727

RESUMEN

PURPOSE: To evaluate the accuracy of measuring volumes using three-dimensional ultrasound (3D US), and to verify the feasibility of the replacement of CT-MR fusion images with CT-3D US in radiotherapy treatment planning. METHODS: Phantoms, consisting of water, contrast agent, and agarose, were manufactured. The volume was measured using 3D US, CT, and MR devices. A CT-3D US and MR-3D US image fusion software was developed using the Insight Toolkit library in order to acquire three-dimensional fusion images. The quality of the image fusion was evaluated using metric value and fusion images. RESULTS: Volume measurement, using 3D US, shows a 2.8 ± 1.5% error, 4.4 ± 3.0% error for CT, and 3.1 ± 2.0% error for MR. The results imply that volume measurement using the 3D US devices has a similar accuracy level to that of CT and MR. Three-dimensional image fusion of CT-3D US and MR-3D US was successfully performed using phantom images. Moreover, MR-3D US image fusion was performed using human bladder images. CONCLUSIONS: 3D US could be used in the volume measurement of human bladders and prostates. CT-3D US image fusion could be used in monitoring the target position in each fraction of external beam radiation therapy. Moreover, the feasibility of replacing the CT-MR image fusion to the CT-3D US in radiotherapy treatment planning was verified.


Asunto(s)
Algoritmos , Procesamiento de Imagen Asistido por Computador/métodos , Imagenología Tridimensional/métodos , Neoplasias de la Próstata/diagnóstico , Neoplasias de la Próstata/radioterapia , Tomografía Computarizada por Rayos X/métodos , Ultrasonografía/métodos , Humanos , Masculino , Tamaño de los Órganos , Fantasmas de Imagen , Neoplasias de la Próstata/patología , Sensibilidad y Especificidad , Carga Tumoral
13.
J Cardiovasc Ultrasound ; 19(4): 203-6, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22259665

RESUMEN

Central venous stenosis or occlusion occurs in 11-50% of hemodialysis patients with prior subclavian vein cannulation and ipsilateral fistula or shunt. Most patients are asymptomatic but some require treatment to reduce the risk of thrombosis and improve inadequate hemodialysis pressure. In these cases, endovascular intervention, including ballooning and stenting, is a feasible strategy for selected patents. We report an unusual case of a 40-year-old man on hemodialysis that underwent endovascular stenting to treat right subclavian vein stenosis and experienced stent migration to the right ventricle, requiring surgical removal.

14.
J Phys Chem B ; 110(47): 23678-82, 2006 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-17125326

RESUMEN

The photorefractive effect of a layer-structured liquid crystal cell was significantly enhanced when a C60-doped poly(9-vinylcarbazole) (PVK)/TiO2 nanocomposite was used in two photoconductive layers. The C60-doped PVK/TiO2 nanocomposite film was prepared by infiltrating C60-doped PVK into a highly ordered mesoporous TiO2 layer. The addition of the TiO2 layer to the C60-doped PVK layer increased the first-order Raman-Nath diffraction efficiency from 24% to 42.9%. This enhancement of diffraction efficiency is attributed to a blocking effect of charge recombination in the composite layer. The electron transfer from the PVK layer into the TiO2 layer would decrease the recombination of photogenerated charges in the PVK layer, while charges in the PVK layer could participate in the formation of a space-charge field.

15.
Chem Commun (Camb) ; (13): 1514-5, 2004 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-15216357

RESUMEN

Highly ordered mesoporous titania films were synthesized within a short time period by controlling the pH of sols and moisture exposure of as-prepared films.

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