204 research outputs found
Influence of the waist diameters on transmission characteristics and strain sensitivity of microtapered long-period fiber gratings
Transmission characteristics of microtapered long-period fiber gratings (MTLPGs) and their strain and temperature sensitivities with variations in the waist diameters are investigated theoretically and experimentally. Transmission characteristics of MTLPGs strongly depend on the waist diameter of the tapered optical fiber (TOF) because of the modification of the effective index difference between the core and the cladding modes. Based on the photoelastic effect, the resonant wavelengths of MTLPGs with variations in strain shift to shorter wavelengths. The strain sensitivity of the MTLPG with a waist diameter of 25 μm is improved by a factor of 20 compared with that of a 125 μm long-period fiber grating. The temperature sensitivities of MTLPGs are also enhanced by reducing the waist diameter of the TOF
Massively Parallel Signature Sequencing and Bioinformatics Analysis Identifies Up-Regulation of TGFBI and SOX4 in Human Glioblastoma
BACKGROUND: A comprehensive network-based understanding of molecular pathways abnormally altered in glioblastoma multiforme (GBM) is essential for developing effective therapeutic approaches for this deadly disease. METHODOLOGY/PRINCIPAL FINDINGS: Applying a next generation sequencing technology, massively parallel signature sequencing (MPSS), we identified a total of 4535 genes that are differentially expressed between normal brain and GBM tissue. The expression changes of three up-regulated genes, CHI3L1, CHI3L2, and FOXM1, and two down-regulated genes, neurogranin and L1CAM, were confirmed by quantitative PCR. Pathway analysis revealed that TGF- beta pathway related genes were significantly up-regulated in GBM tumor samples. An integrative pathway analysis of the TGF beta signaling network identified two alternative TGF-beta signaling pathways mediated by SOX4 (sex determining region Y-box 4) and TGFBI (Transforming growth factor beta induced). Quantitative RT-PCR and immunohistochemistry staining demonstrated that SOX4 and TGFBI expression is elevated in GBM tissues compared with normal brain tissues at both the RNA and protein levels. In vitro functional studies confirmed that TGFBI and SOX4 expression is increased by TGF-beta stimulation and decreased by a specific inhibitor of TGF-beta receptor 1 kinase. CONCLUSIONS/SIGNIFICANCE: Our MPSS database for GBM and normal brain tissues provides a useful resource for the scientific community. The identification of non-SMAD mediated TGF-beta signaling pathways acting through SOX4 and TGFBI (GENE ID:7045) in GBM indicates that these alternative pathways should be considered, in addition to the canonical SMAD mediated pathway, in the development of new therapeutic strategies targeting TGF-beta signaling in GBM. Finally, the construction of an extended TGF-beta signaling network with overlaid gene expression changes between GBM and normal brain extends our understanding of the biology of GBM
Choroidal Thickness in Eyes with Unilateral Ocular Ischemic Syndrome
Aim. To analyze the subfoveal choroid thickness and choroidal volume in unilateral ocular ischemic syndrome (OIS). Methods. A retrospective review was conducted for all patients with unilateral OIS from October 2010 through June 2014. The subfoveal choroidal thickness (SFChT) and choroidal volume of both eyes were compared. Results. 19 unilateral OIS patients were included in this study. The mean SFChT of OIS eyes was significantly lower than that of fellow eyes (OIS eyes: 208.89 ± 82.62 μm and fellow eyes: 265.31 ± 82.77 μm, P<0.001). The choroidal volume of OIS eyes was significantly smaller than that of fellow eyes (OIS eyes: 0.16 ± 0.05 mm3 and fellow eyes: 0.21 ± 0.05 mm3, P<0.001). Conclusion. The choroidal thickness and volume of OIS eyes were smaller than those of unaffected fellow eyes. Decreased choroidal circulation caused by carotid artery stenosis might affect the discordance of choroidal thickness and choroidal volume
Delivery of bone morphogenetic protein-2 and substance P using graphene oxide for bone regeneration
YAF2 promotes TP53-mediated genotoxic stress response via stabilization of PDCD5
AbstractProgrammed cell death 5 (PDCD5) plays a crucial role in TP53-mediated apoptosis, but the regulatory mechanism of PDCD5 itself during apoptosis remains obscure. We identified YY1-associated factor 2 (YAF2) as a novel PDCD5-interacting protein in a yeast two-hybrid screen for PDCD5-interacting proteins. We found that YY1-associated factor 2 (YAF2) binds to and increases PDCD5 stability by inhibiting the ubiquitin-dependent proteosomal degradation pathway. However, knocking-down of YAF2 diminishes the levels of PDCD5 protein but not the levels of PDCD5 mRNA. Upon genotoxic stress response, YAF2 promotes TP53 activation via association with PDCD5. Strikingly, YAF2 failed to promote TP53 activation in the deletion of PDCD5, whereas restoration of wild-type PDCD5WT efficiently reversed the ineffectiveness of YAF2 on TP53 activation. Conversely, PDCD5 efficiently overcame the knockdown effect of YAF2 on ET-induced TP53 activation. Finally, impaired apoptosis upon PDCD5 ablation was substantially rescued by restoration of PDCD5WT but not YAF2-interacting defective PDCD5E4D nor TP53-interacting defective PDCD5E16D mutant. Our findings uncovered an apoptotic signaling cascade linking YAF2, PDCD5, and TP53 during genotoxic stress responses
Anti-inflammatory effects of isoketocharbroic acid from brown alga, Sargassum micracanthum
During our on-going screening program designed to isolate natural compounds from marine environments, we isolated isoketochabrolic acid (IKCA) from Sargassum micracanthum, an important brown algae distributed in Jeju Island, Korea. Furthermore, we evaluated the inhibitory effects of IKCA on nitric oxide (NO) production in lipopolysaccharide (LPS)-triggered macrophages. IKCA strongly inhibited NO production, with an IC50 value of 58.31 μM. Subsequent studies demonstrated that IKCA potently and concentration-dependently reduced prostaglandin E2 (PGE2), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, and IL-6 cytokine production. In conclusion, to the best of our knowledge, this is the first study to show that IKCA isolated from S. micracanthum has a potent anti-inflammatory activity. Therefore, IKCA might be useful as an anti-inflammatory health supplement or functional cosmetics
Influence of the waist diameters on transmission characteristics and strain sensitivity of microtapered long-period fiber gratings
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