1,704 research outputs found

    Enhanced light harvesting in bulk heterojunction photovoltaic devices with shape-controlled Ag nanomaterials: Ag nanoparticles versus Ag nanoplates

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    Enhanced power conversion efficiency (PCE(%)) with improved optical path length from two types of shape controlled silver (Ag) materials (Ag nanoplates versus Ag nanoparticles (NPs)) was studied in poly(3-hexylthiophene) (P3HT)/[6,6]-phenyl C 71 butyric acid methyl-ester (PC 71BM) or poly[N-9′′-hepta-decanyl-2,7-carbazole-alt-5,5-(4′, 7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)] (PCDTBT)/[6,6]-phenyl C 71 butyric acid methyl-ester (PC 71BM) bulk heterojunction (BHJ) devices. The Ag nanoplates and Ag NPs can be synthesized by simple solution polyol chemistry with well defined size and shape. A BHJ with a 0.5 wt% optimized blend ratio of Ag nanoplates shows improved cell performance and photo-current density than a BHJ with Ag NPs owing to the enhanced light absorption with the results of an excitation of localized surface plasmon and efficient light scattering by the Ag nanoplates embedded BHJ film. When the BHJ is combined with the Ag nanoplates at an optimized ratio of 0.5 wt%, the PCE (%) increases from 3.2% to 4.4% in P3HT/PC 71BM, and from 5.9% to 6.6% in PCDTBT/PC 71BM BHJ devices. © 2012 The Royal Society of Chemistry.1

    4.EAFES International Congress in Mokpo, Korea

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    Korea Forest Research InstituteProject Number 14404021, Peport of Research Project ; Grant-in-Aid for Scientific Research(B)(2), from April 2002 to March 2006, Edited by Muramoto,Ken-ichiroKamata, NaotoKawanishi, TakuyaKubo, MamoruLiu, JiyuanLee, Kyu-Sung , 人工衛星データ活用のための東アジアの植生調査、課題番号14404021, 平成14年度~平成17年度科学研究費補助金, 基盤研究(B)(2)研究成果報告書, 研究代表者:村本, 健一郎, 金沢大学自然科学研究科教

    Titanium dioxide induces apoptotic cell death through reactive oxygen species-mediated Fas upregulation and Bax activation

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    Background: Titanium dioxide (TiO2) has been widely used in many areas, including biomedicine, cosmetics, and environmental engineering. Recently, it has become evident that some TiO2 particles have a considerable cytotoxic effect in normal human cells. However, the molecular basis for the cytotoxicity of TiO2 has yet to be defined.Methods and results: In this study, we demonstrated that combined treatment with TiO2 nanoparticles sized less than 100 nm and ultraviolet A irradiation induces apoptotic cell death through reactive oxygen species-dependent upregulation of Fas and conformational activation of Bax in normal human cells. Treatment with P25 TiO2 nanoparticles with a hydrodynamic size distribution centered around 70 nm (TiO2P25-70) together with ultraviolet A irradiation-induced caspase-dependent apoptotic cell death, accompanied by transcriptional upregulation of the death receptor, Fas, and conformational activation of Bax. In line with these results, knockdown of either Fas or Bax with specific siRNA significantly inhibited TiO2-induced apoptotic cell death. Moreover, inhibition of reactive oxygen species with an antioxidant, N-acetyl-L-cysteine, clearly suppressed upregulation of Fas, conformational activation of Bax, and subsequent apoptotic cell death in response to combination treatment using TiO2P25-70 and ultraviolet A irradiation.Conclusion: These results indicate that sub-100 nm sized TiO2 treatment under ultraviolet A irradiation induces apoptotic cell death through reactive oxygen species-mediated upregulation of the death receptor, Fas, and activation of the preapoptotic protein, Bax. Elucidating the molecular mechanisms by which nanosized particles induce activation of cell death signaling pathways would be critical for the development of prevention strategies to minimize the cytotoxicity of nanomaterials.This work was supported by the Korea Ministry of Environment and The Eco-Technopia 21 Project (091-091-081)

    Estimation of Electromagnetic Field Penetration into Concrete Buildings Using a Theoretical Approach Considering External Environmental Factors

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    In this paper, we propose a theoretical approach to estimate the power level of electromagnetic waves radiated into a structure by a specific external source. The target structure is a multistory building on a university campus that is used primarily for academic purposes and is much larger than the target wavelength. To verify the accuracy and efficiency of the proposed theoretical approach, measurements were carried out and a commercially available simulation tool, Wireless Insite, was adopted. We then analyzed the influence of an area of vegetation as an external environmental factor that could affect the radiated electromagnetic waves because of its location in front of the target structure. For this, a precise simulation environment was designed to derive the quantitative values of the electromagnetic attenuation caused by the external environmental factor. Furthermore, those values were applied to the theoretical approach. The results of the theoretical approach accounting for the external environmental factor were similar to those of the actual measured results. The results were also similar to those of the simulation tool, Wireless Insite, but the theoretical approach provided more efficient analysis results in terms of time consumption and computer resources

    The Usefulness of Rectified VEMP

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    Eosinophilic Otitis Media: CT and MRI Findings and Literature Review

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    Eosinophilic otitis media (EOM) is a relatively rare, intractable, middle ear disease with extremely viscous mucoid effusion containing eosinophils. EOM is associated with adult bronchial asthma and nasal allergies. Conventional treatments for otitis media with effusion (OME) or for chronic otitis media (COM), like tympanoplasty or mastoidectomy, when performed for the treatment of EOM, can induce severe complications such as deafness. Therefore, it should be differentiated from the usual type of OME or COM. To our knowledge, the clinical and imaging findings of EOM of temporal bone are not well-known to radiologists. We report here the CT and MRI findings of two EOM cases and review the clinical and histopathologic findings of this recently described disease entity

    Summary of the 2017 thyroid radiofrequency ablation guideline and comparison with the 2012 guideline

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    Radiofrequency ablation (RFA) is a new, minimally invasive modality that serves as an alternative to surgery in patients with thyroid tumors. The Task Force Committee of the Korean Society of Thyroid Radiology developed recommendations for the optimal use of RFA for thyroid tumors in 2012 and revised them in 2017. Herein, we review and summarize the 2017 thyroid RFA guideline and compare it with the 2012 thyroid RFA guideline
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