802 research outputs found

    Structural Engineering on Pt-Free Electrocatalysts for Dye-Sensitized Solar Cells

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    In recent decades, plenty of nanomaterials have been investigated as electrocatalysts for the replacement of the expensive platinum (Pt) counter electrode in dye-sensitized solar cells (DSSCs). The key function of the electrocatalyst is to reduce tri-iodide ions to iodide ions at the electrolyte/counter electrode interface. The performance of the electrocatalyst is usually determined by two key factors, i.e., the intrinsic heterogeneous rate constant and the effective electrocatalytic surface area of the electrocatalyst. The intrinsic heterogeneous rate constant of the electrocatalyst varies by different types of materials, which can be roughly divided into five groups: non-Pt metals, carbons, conducting polymers, transition metal compounds, and their composites. The effective electrocatalytic surface area is determined by the nanostructure of the electrocatalyst. In this chapter, the nanostructural design and engineering on different types of Pt-free electrocatalysts will be systematically introduced. Also, the relationship between various nanostructures of electrocatalysts and the pertinent physical/electrochemical properties will be discussed

    Validation of bidimensional measurement in nasopharyngeal carcinoma

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    <p>Abstract</p> <p>Background</p> <p>Our previous study showed a close relationship between computed tomography (CT)-derived bidimensional measurement of primary tumor and retropharyngeal nodes (BDMprn) and gross tumor volume of primary tumor and retropharyngeal nodes (GTVprn) in nasopharyngeal carcinoma (NPC) and better prognosis for NPC patients with smaller BDMprn. In this study, we report the results on of a study to validate the use of BDM in a separate cohort of NPC patients.</p> <p>Methods</p> <p>We retrospectively reviewed 103 newly diagnosed NPC cases who were treated with radiotherapy/concurrent chemoradiotherapy (CCRT) or CCRT with adjuvant chemotherapy from 2002 to 2009. We used magnetic resonance imaging (MRI) to measure BDMprn. We calculated overall survival, recurrence-free and distant metastasis-free survival curves and set a BDMprn cut off point to categorize patients into a high- or low-risk group. We then used Cox proportional hazard model to evaluate the prognostic influence of BDMprn after correcting age, gender and chemotherapy status.</p> <p>Results</p> <p>After adjusting for age, gender, and chemotherapy status, BDMprn remained an independent prognostic factor for distant metastasis [Hazard ratio (HR) = 1.046; <it>P </it>= 0.042] and overall survival (HR = 1.012; <it>P </it>= 0.012). Patients with BDMprn < 15 cm<sup>2 </sup>had a greater 3-year overall survival rate than those with BDMprn ≧ 15 cm<sup>2 </sup>(92.3% vs. 73.7%; <it>P </it>= 0.009). They also had a greater 3-year distant metastasis-free survival (94% vs.75%; <it>P </it>= 0.034).</p> <p>Conclusion</p> <p>The predictive ability of BDMprn was validated in a separate NPC cohort. A BDMprn of 15 cm<sup>2 </sup>can be used to separate NPC patients into high- and low-risk groups and predict survival rates and metastasis potential. It can, therefore, be used as a reference to design clinical trials, predict prognosis, and make treatment decisions.</p

    Epidemic Pleurodynia Caused by Coxsackievirus B3 at a Medical Center in Northern Taiwan

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    Epidemic pleurodynia is seldom reported in Southeast Asia and there has been no report from Taiwan. We conducted a retrospective chart review of children = 18 years of age in the National Taiwan University Hospital from January 1 to December 31, 2005. Epidemic pleurodynia was defined as an acute illness characterized by sharp localized pain over the chest or upper abdomen. Patients with known heart diseases or pulmonary consolidations were excluded. In total, 28 patients met the case definition of epidemic pleurodynia. Coxsackievirus B3 (CB3) was isolated in 15 (60%) of the 25 throat swab specimens. Four (14%) of the 28 patients presented chest wall tenderness and only one (6%) of the 18 patients tested had an elevated creatinine kinase level. Twenty-one (75%) of the 28 patients described pleuritic chest pains and 10 (45%) of the 22 chest radiographies exhibited pulmonary infiltrates or pleural effusions. Six patients were observed with tonsillar exudates and one was confirmed to have a CB3 urinary tract infection. The clinical features and radiological findings suggest that CB3-associated epidemic pleurodynia might be a disease of the pleura and occasionally spreads to nearby tissues, resulting in chest wall myositis, pulmonary infiltrates and myopericarditis

    Color-tunable mixed photoluminescence emission from Alq3 organic layer in metal-Alq3-metal surface plasmon structure

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    This work reports the color-tunable mixed photoluminescence (PL) emission from an Alq(3) organic layer in an Au-Alq(3)-Au plasmonic structure through the combination of organic fluorescence emission and another form of emission that is enabled by the surface plasmons in the plasmonic structure. The emission wavelength of the latter depends on the Alq(3) thickness and can be tuned within the Alq(3) fluorescent spectra. Therefore, a two-color broadband, color-tunable mixed PL structure was obtained. Obvious changes in the Commission Internationale d’Eclairage (CIE) coordinates and the corresponding emission colors of Au-Alq(3)-Au samples clearly varied with the Alq(3) thickness (90, 130, and 156 nm)

    Nocturnal CPAP improves walking capacity in COPD patients with obstructive sleep apnoea

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    BACKGROUND: Exercise limitation is an important issue in patients with chronic obstructive pulmonary disease (COPD), and it often co-exists with obstructive sleep apnoea (overlap syndrome). This study examined the effects of nocturnal continuous positive airway pressure (CPAP) treatment on walking capacity in COPD patients with or without obstructive sleep apnoea. METHODS: Forty-four stable moderate-to-severe COPD patients were recruited and completed this study. They all underwent polysomnography, CPAP titration, accommodation, and treatment with adequate pressure. The incremental shuttle walking test was used to measure walking capacity at baseline and after two nights of CPAP treatment. Urinary catecholamine and heart rate variability were measured before and after CPAP treatment. RESULTS: After two nights of CPAP treatment, the apnoea-hypopnoea index and oxygen desaturation index significantly improved in both overlap syndrome and COPD patients, however these changes were significantly greater in the overlap syndrome than in the COPD group. Sleep architecture and autonomic dysfunction significantly improved in the overlap syndrome group but not in the COPD group. CPAP treatment was associated with an increased walking capacity from baseline from 226.4 ± 95.3 m to 288.6 ± 94.6 m (P < 0.05), and decreased urinary catecholamine levels, pre-exercise heart rate, oxygenation, and Borg scale in the overlap syndrome group. An improvement in the apnoea-hypopnoea index was an independent factor associated with the increase in walking distance (r = 0.564). CONCLUSION: Nocturnal CPAP may improve walking capacity in COPD patients with overlap syndrome. TRIAL REGISTRATION: NCT0091426

    Fibromodulin Reprogrammed Cells: A Novel Cell Source for Bone Regeneration

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    Pluripotent or multipotent cell-based therapeutics are vital for skeletal reconstruction in non-healing critical-sized defects since the local endogenous progenitor cells are not often adequate to restore tissue continuity or function. However, currently available cell-based regenerative strategies are hindered by numerous obstacles including inadequate cell availability, painful and invasive cell-harvesting procedures, and tumorigenesis. Previously, we established a novel platform technology for inducing a quiescent stem cell-like stage using only a single extracellular proteoglycan, fibromodulin (FMOD), circumventing gene transduction. In this study, we further purified and significantly increased the reprogramming rate of the yield multipotent FMOD reprogrammed (FReP) cells. We also exposed the \u27molecular blueprint\u27 of FReP cell osteogenic differentiation by gene profiling. Radiographic analysis showed that implantation of FReP cells into a critical-sized SCID mouse calvarial defect, contributed to the robust osteogenic capability of FReP cells in a challenging clinically relevant traumatic scenario in vivo. The persistence, engraftment, and osteogenesis of transplanted FReP cells without tumorigenesis in vivo were confirmed by histological and immunohistochemical staining. Taken together, we have provided an extended potency, safety, and molecular profile of FReP cell-based bone regeneration. Therefore, FReP cells present a high potential for cellular and gene therapy products for bone regeneration. © 2016 Elsevier Ltd

    Fibromodulin Reduces Scar Formation in Adult Cutaneous Wounds by Eliciting a Fetal-Like Phenotype

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    Blocking transforming growth factor (TGF)β1 signal transduction has been a central strategy for scar reduction; however, this approach appears to be minimally effective. Here, we show that fibromodulin (FMOD), a 59-kD small leucine-rich proteoglycan critical for normal collagen fibrillogenesis, significantly reduces scar formation while simultaneously increasing scar strength in both adult rodent models and porcine wounds, which simulate human cutaneous scar repair. Mechanistically, FMOD uncouples pro-migration/contraction cellular signals from pro-fibrotic signaling by selectively enhancing SMAD3-mediated signal transduction, while reducing AP-1-mediated TGFβ1 auto-induction and fibrotic extracellular matrix accumulation. Consequently, FMOD accelerates TGFβ1-responsive adult fibroblast migration, myofibroblast conversion, and function. Furthermore, our findings strongly indicate that, by delicately orchestrating TGFβ1 activities rather than indiscriminately blocking TGFβ1, FMOD elicits fetal-like cellular and molecular phenotypes in adult dermal fibroblasts in vitro and adult cutaneous wounds in vivo, which is a unique response of living system undescribed previously. Taken together, this study illuminates the signal modulating activities of FMOD beyond its structural support functions, and highlights the potential for FMOD-based therapies to be used in cutaneous wound repair. © The Author(s) 2017
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