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1.
Small Methods ; 8(1): e2300790, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37749956

ABSTRACT

Employing porous structures is essential in high-performance electrochemical energy devices. However, obtaining uniform functional coatings on high-tortuosity structures can be challenging, even with specialized processes such as atomic layer deposition (ALD). Herein, a novel method for achieving a porous composite electrode for solid oxide fuel cells by coating La0.6 Sr0.4 Co0.2 Fe0.8 O3 -δ (LSCF) powders with ZrO2 using a powder ALD process is presented. Unlike conventional ALD, powder ALD can be used to fabricate extremely uniform coatings on porous electrodes with a thickness of tens of micrometers. The powder ALD ZrO2 coating is found to effectively suppress chemical degradation of the LSCF electrodes. The cell with the powder ALD coated cathode shows a 2.2 times higher maximum power density and 60% lower thermal degradation in activation resistance than the bare LSCF cathode cell at 700-750 °C. The result demonstrated in this study is expected to have significant implications for high-performance and durable electrodes in energy conversion/storage devices.

2.
J Med Food ; 26(8): 595-604, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37594560

ABSTRACT

Acorn (Quercus acutissima CARR.) has been used in traditional food and medicinal ethnopharmacology in Asia, and it has shown multifarious functions such as antidementia, antiobesity, and antiasthma functions. However, there is limited scientific evidence about the efficacy of acorn for ameliorating skin problems. Treatment with ethanol-extracted acorns (EeA's) ablated the expression of inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX2), monocyte chemoattractant protein-1 (MCP-1), and interleukin (IL)-8 stimulated by tumor necrosis factor (TNF)-α in human adult low calcium high temperature (HaCaT) cells under sublethal dosages. In addition, treatment with EeA dose dependently inhibited the ex vivo hyper keratin formation induced by TNF-α in HaCaT cells in conjunction with the blockade of cytokeratin-1 (CK-1) and cytokeratin-5 (CK-5) expression. Moreover, EeA treatment stimulated the expression of hyaluronic acid (HA) expression in human fibroblasts in a dose-dependent manner. Linoleamide was identified as the functional component of EeA using preparative high-performance liquid chromatography and ultra high performance liquid chromatography-mass spectrometry-mass spectrometry analysis, and the anti-inflammatory features and enhanced HA expression were verified. Collectively, these results suggest the efficacy of EeA supplementation in improving skin problems via anti-inflammation and upregulating HA production.


Subject(s)
Hyaluronic Acid , Quercus , Adult , Humans , Keratinocytes , HaCaT Cells , Ethanol
3.
Biochem Biophys Res Commun ; 599: 100-105, 2022 04 09.
Article in English | MEDLINE | ID: mdl-35180468

ABSTRACT

BACKGROUND: Luffa cylindrica stem sap (LuCS) has been ethnopharmacologically used as a cosmetic ingredients to improve the facial condition in Asians, but there is no scientific proof about the advantages of LuCS as a supplement for skin elasticity inducer. PURPOSE: Presently, we have validated the beneficial effect of LuCS in human preadipocyte and fibroblast. METHODS: In vitro activities of LuCS on expression of cellular elastin and collagen type I were validated using Western blot analysis in human fibroblasts. Effect of LuCS on preadipocyte development was performed using MDI medium containing isobutyl-methylxanthine, dexamethasone, and insulin and then evaluated using oil red O staining. RESULTS: Treatment of LuCS stimulated the expression of cellular elastin and type I procollagen in human skin fibroblasts. Exposure to LuCS induced lipid accumulation of preadipocytes via activation of CEBP/α signaling pathway in preadipocytes. Expression of collagen I, elastin, or CEBP/α mRNA was decreased by age. 3-bromo-3-methylisoxazol-5-amine enhanced the synthesis of cellular lipid in preadipocytes. CONCLUSIONS: Collectively, these results suggest the rationale of LuCS treatment in enhancing the skin condition.


Subject(s)
Adipocytes/drug effects , Fibroblasts/drug effects , Luffa/chemistry , Plant Extracts/pharmacology , 3T3-L1 Cells , Adipocytes/metabolism , Animals , Cells, Cultured , Collagen/genetics , Collagen/metabolism , Drug Evaluation, Preclinical/methods , Elastin/genetics , Elastin/metabolism , Fibroblasts/metabolism , Gene Expression Regulation/drug effects , Humans , Lipid Metabolism/drug effects , Mice , Plant Extracts/chemistry , Procollagen/genetics , Procollagen/metabolism
4.
Biochem Biophys Res Commun ; 580: 41-47, 2021 11 26.
Article in English | MEDLINE | ID: mdl-34619551

ABSTRACT

Luffa cylindrica stem sap (LuCS) has been traditionally used as a facial cosmetic supplement to enhance the skin condition of Asians. However, LuCS has yet to be described and there is no solid scientific evidence regarding the use of LuCS as an anti-wrinkle agent. In the present study, we have evaluated the functional effect of LuCS and its underlying mechanisms based on scientific evidence. Treatment with LuCS stimulated the growth and migration of human skin fibroblasts. LuCS treatment activated EGFR signaling via the enhanced expression of EGFR and down-regulation of PPARγ in human skin fibroblasts. Exposure to LuCS induced the synthesis of cellular type I procollagen and elastin in consort with the down-regulation of various proteinases including MMP-1, -2 and -9 in human skin fibroblasts. LuCS treatment also reversed the skin damage induced by UV-A irradiation in human skin fibroblasts. 3-bromo-3-methylisoxazol-5-amine was identified as the functional component using UPLC-MS-MS analysis and increased production of cellular type I procollagen. Collectively, these results suggest the efficacy of LuCS supplementation in improving the skin condition via anti-wrinkle effect.


Subject(s)
Fibroblasts/drug effects , Luffa , Plant Extracts/pharmacology , Protective Agents/pharmacology , Skin Aging/drug effects , Cell Line , Cell Survival/drug effects , Cell Survival/radiation effects , Fibroblasts/cytology , Fibroblasts/radiation effects , Humans , Luffa/chemistry , Plant Extracts/chemistry , Plant Stems/chemistry , Protective Agents/chemistry
5.
Korean J Fam Med ; 42(3): 225-231, 2021 05.
Article in English | MEDLINE | ID: mdl-32746541

ABSTRACT

BACKGROUND: Although many studies have demonstrated that the first cigarette in the morning increases the prevalence of smoking-related morbidity, limited studies have examined the impact of time to first cigarette (TTFC) on the health-related quality of life (HRQoL). Thus, we assessed this relationship using nationally-representative data from the Korea National Health and Nutrition Examination Survey VII-1 (2016). METHODS: We conducted a cross-sectional study using data from 577 current male smokers aged 30-59 years, after excluding those with a certain disease. Participants were divided into four categories according to TTFC (≤5 min, 6-30 min, 31-60 min, >60 min). HRQoL was measured using self-reported EuroQol-5 (EQ-5D). The relationship between TTFC and EQ-5D index was analyzed using a multivariate-adjusted generalized linear model to assess how HRQoL varies according to TTFC. After adjusting for confounders, a multivariate-adjusted logistic regression analysis was performed to identify which of the five dimensions of the EQ-5D affected the HRQoL according to TTFC. RESULTS: The generalized linear analysis indicated that as TTFC decreased (6-30 min, 31-60 min vs. >60 min), the EQ-5D index score decreased significantly (P=0.037). Shorter TTFC (≤5 min vs. >60 min) was associated with higher pain/discomfort (odds ratio [OR], 3.82; 95% confidence interval [CI], 1.39-10.48) and anxiety/depression (OR, 7.58; 95% CI, 1.75-32.88). CONCLUSION: Higher nicotine dependence was associated with impaired HRQoL. These results may be used to improve smoking cessation treatment outcomes.

6.
Sci Rep ; 6: 27913, 2016 06 10.
Article in English | MEDLINE | ID: mdl-27283350

ABSTRACT

Solar thermoelectric generators (STEGs), which are used for various applications, (particularly small size electronic devices), have optical concentration systems for high energy conversion efficiency. In this study, a refraction-assisted STEG (R-STEG) is designed based on phase-change materials. As the phase-change material (PCM) changes phase from solid to liquid, its refractive index and transmittance also change, resulting in changes in the refraction of the sunlight transmitted through it, and concentration of solar energy in the phase-change lens. This innovative design facilitates double focusing the solar energy through the optical lens and a phase-change lens. This mechanism resulted in the peak energy conversion efficiencies of the R-STEG being 60% and 86% higher than those of the typical STEG at solar intensities of 1 kW m(-2) and 1.5 kW m(-2), respectively. In addition, the energy stored in PCM can help to generate steady electrical energy when the solar energy was removed. This work presents significant progress regarding the optical characteristic of PCM and optical concentration systems of STEGs.

7.
J Biotechnol ; 227: 72-78, 2016 Jun 10.
Article in English | MEDLINE | ID: mdl-27059482

ABSTRACT

Xylose is a major monosugar in cellulosic biomass and should be utilized for cost-effective ethanol production. In this study, xylose-converting ability of recombinant Saccharomyces cerevisiae SX6(MUT) expressing NADH-preferring xylose reductase mutant (R276H) and other xylose-metabolic enzymes, and deficient in aldehyde dehydrogenase 6 (Ald6p) were characterized at microaerobic conditions using various sugar mixtures. The reduction of air supply from 0.5vvm to 0.1vvm increased specific ethanol production rate by 75% and did not affect specific xylose consumption rate. In batch fermentations using various concentrations of xylose (50-104g/L), higher xylose concentration enhanced xylose consumption rate and ethanol productivity but reduced ethanol yield, owing to the accumulation of xylitol and glycerol from xylose. SX6(MUT) consumed monosugars in pitch pine hydrolysates and produced 23.1g/L ethanol from 58.7g/L sugars with 0.39g/g ethanol yield, which was 14% higher than the host strain of S. cerevisiae D452-2 without the xylose assimilating enzymes. In conclusion, S. cerevisiae SX6(MUT) was characterized to possess high xylose-consuming ability in microaerobic conditions and a potential for ethanol production from cellulosic biomass.


Subject(s)
Aldehyde Oxidoreductases/metabolism , Coenzymes/metabolism , Ethanol/metabolism , Recombination, Genetic/genetics , Saccharomyces cerevisiae/metabolism , Xylose/metabolism , Acetates/pharmacology , Aerobiosis , Batch Cell Culture Techniques , Carbohydrate Metabolism/drug effects , Fermentation , Hydrolysis , Pinus/chemistry , Recombinant Proteins/metabolism
8.
Rev Sci Instrum ; 84(6): 065112, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23822383

ABSTRACT

In this paper, the improvement of range precision in a laser detection and ranging (LADAR) system by using two Geiger mode avalanche photodiodes (GmAPDs) is described. The LADAR system is implemented by using two GmAPDs with a beam splitter and applying comparative process to their ends. Then, the timing circuit receives the electrical signals only if each GmAPDs generates electrical signals simultaneously. Though this system decreases the energy of a laser-return pulse scattered from the target, it is effective in reducing the range precision. The experimental results showed that the average value of standard deviation of time of flights was improved from 61 mm to 37 mm when the pulse energy is 0.6 µJ. When the time bin width is 0.5 ns, the single-shot precision error of the LADAR system was also improved from 280 mm to 67 mm.

9.
Med Biol Eng Comput ; 50(9): 973-80, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22806430

ABSTRACT

Induction coils were fabricated based on flexible printed circuit board for inductive transcutaneous power transmission. The coil had closed magnetic circuit (CMC) structure consisting of inner and outer magnetic core. The power transmission efficiency of the fabricated device was measured in the air and in vivo condition. It was confirmed that the CMC coil had higher transmission efficiency than typical air-core coil. The power transmission efficiency during a misalignment between primary coil and implanted secondary coil was also evaluated. The decrease of mutual inductance between the two coils caused by the misalignment led to a low efficiency of the inductive link. Therefore, it is important to properly align the primary coil and implanted secondary coil for effective power transmission. To align the coils, a feedback coil was proposed. This was integrated on the backside of the primary coil and enabled the detection of a misalignment of the primary and secondary coils. As a result of using the feedback coil, the primary and secondary coils could be aligned without knowledge of the position of the implanted secondary coil.


Subject(s)
Electric Power Supplies , Magnetics/instrumentation , Prostheses and Implants , Wireless Technology/instrumentation , Computer-Aided Design , Energy Transfer , Equipment Failure Analysis , Prosthesis Design , Systems Integration
10.
Opt Express ; 19(20): 19323-9, 2011 Sep 26.
Article in English | MEDLINE | ID: mdl-21996872

ABSTRACT

In this paper, we propose a new method that is capable of obtaining a clear 3D image by the reduction of false alarms caused by noise in the stage of acquisition of raw time of flight (TOF) data. This method is implemented by intensity dividing a laser-return pulse into two Geiger-mode avalanche photodiodes (GmAPDs); an AND gate compares the arrival time of the electrical signals from the GmAPDs. Despite the fact that the energy of a laser-return pulse is decreased by half, the false alarm probability is drastically decreased because the noise distributed randomly in the time domain is filtered out. The experimental measurement is in agreement with the theoretical analysis. As a result, we can obtain a clear 3D image despite the high noise.


Subject(s)
Image Interpretation, Computer-Assisted/methods , Imaging, Three-Dimensional/instrumentation , Phantoms, Imaging , Equipment Design , Lasers
11.
J Opt Soc Am A Opt Image Sci Vis ; 28(5): 759-65, 2011 May 01.
Article in English | MEDLINE | ID: mdl-21532685

ABSTRACT

In this paper, a photon-counting three-dimensional imaging laser detection and ranging (LADAR) system that uses a Geiger-mode avalanche photodiode (GAPD) of relatively short dead time (45 ns) is described. A passively Q-switched microchip laser is used as a laser source and a compact peripheral component interconnect system, which includes a time-to-digital converter (TDC), is set up for fast signal processing. The combination of a GAPD with short dead time and a TDC with a multistop function enables the system to operate in a single-hit or a multihit mode during the acquisition of time-of-flight data. The software for the three-dimensional visualization and an algorithm for the removal of noise are developed. For the photon-counting LADAR system, we establish a theoretical model of target-detection and false-alarm probabilities in both the single-hit and multihit modes with a Poisson statistic; this model provides the prediction of the performance of the system and a technique for the acquisition of a noise image with a GAPD. Both the noise image and the three-dimensional image of a scene acquired by the photon-counting LADAR system during the day are presented.

12.
Opt Lett ; 35(24): 4214-6, 2010 Dec 15.
Article in English | MEDLINE | ID: mdl-21165141

ABSTRACT

An autofocus technique is proposed for a three-dimensional imaging, direct-detection laser radar system that uses a Geiger-mode avalanche photodiode focal plane array (GmAPD-FPA). This technique is implemented by pointing laser pulses on a target of interest and observing its scattered photon distribution on a GmAPD-FPA. Measuring the standard deviation of the photon distribution on a GmAPD-FPA enables the best focus condition to be found. The feasibility of this technique is demonstrated experimentally by employing a 1 × 8 pixel GmAPD-FPA. It is shown that the spatial resolution improves when the GmAPD-FPA is located in the best focus position found by the autofocus technique.

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