Oscillatory behaviour in Type IA FBG: Ruling out chemical complexity

© 2015 SPIE. Type IA FBG are regenerated gratings that appear in hydrogenated germanosilicate fibre of all types during prolonged UV exposure. The gratings are characterised by a large Bragg wavelength shift and a concomitant increase in the mean fibre core index. Modulated index changes are complex by comparison and significantly weaker, often characterised by oscillatory growth behaviour. Low thermal stability of Type IA gratings suggests a possible chemical role similar to thermally processed optical fibres where autocatalysis has been observed. We show that GeOH and SiOH formation are not out-of-phase and follow each other, with no evidence of autocatalysis, ruling out a chemical origin

Evidence of chemical complexity and laser-driven autocatalysis in type IA FBGs

© OSA 2016. We observe the first chemical complexity for Type IA FBG growth under prolonged UV laser exposure. Out-of-phase oscillatory behaviour in GeOH/SiOH formation provides evidence of laser-driven autocatalysis and chemical origins for grating formation

Embedding low loss polymer optical fibre Bragg gratings:two different approaches

In this paper, we present two different ways to embed polymer fibre Bragg gratings (FBGs) into polymer matrices. In the first experiment, we embedded the FBG into a 3D printed polymer structure, whereas in the second experiment, the coating was polymerized around the fibre. In both cases, the response of the grating was unchanged, without any loss or distortion of the FBG signal compared with the bare fibre response. The design of the polymer coating was optimised for the measurement of a single measurand. We highlighted two possible applications: surface bend deformation monitoring and improved-sensitivity temperature sensing

Tomo-seq identifies SOX9 as a key regulator of cardiac fibrosis during ischemic injury

Background: Cardiac ischemic injury induces a pathological remodeling response, which can ultimately lead to heart failure. Detailed mechanistic insights into molecular signaling pathways relevant for different aspects of cardiac remodeling will support the identification of novel therapeutic targets. Methods: While genome-wide transcriptome analysis on diseased tissues has greatly advanced our understanding of the regulatory networks that drive pathological changes in the heart, this approach has been disadvantaged by the fact that the signals are derived from tissue homogenates. Here we used tomo-seq to obtain a genome-wide gene expression signature with high spatial resolution spanning from the infarcted area to the remote to identify new regulators of cardiac remodeling. Cardiac tissue samples from patients suffering from ischemic heart disease were used to validate our findings. Results: Tracing transcriptional differences with a high spatial resolution across the infarcted heart enabled us to identify gene clusters that share a comparable expression profile. The spatial distribution patterns indicated a separation of expressional changes for genes involved in specific aspects of cardiac remodeling, like fibrosis, cardiomyocyte hypertrophy, and calcium-handling (Col1a2, Nppa, and Serca2). Subsequent correlation analysis allowed for the identification of novel factors that share a comparable transcriptional regulation pattern across the infarcted tissue. The strong correlation between the expression levels of these known marker genes and the expression of the co-regulated genes could be confirmed in human ischemic cardiac tissue samples. Follow-up analysis identified SOX9 as common transcriptional regulator of a large portion of the fibrosis-related genes that become activated under conditions of ischemic injury. Lineage-tracing experiments indicated the majority of COL1-positive fibroblasts to stem from a pool of SOX9-expressing cells and in vivo loss of Sox9 blunted the cardiac fibrotic response upon ischemic injury. The co-localization between SOX9 and COL1 could also be confirmed in patients suffering from ischemic heart disease. Conclusions: Based on the exact local expression cues, tomo-seq can serve to reveal novel genes and key transcription factors involved in specific aspects of cardiac remodeling. Using tomo-seq we were able to unveil the unknown relevance of SOX9 as key regulator of cardiac fibrosis, pointing to SOX9 as potential therapeutic target for cardiac fibrosis

Fast and stable gratings inscription in POFs made of different materials with pulsed 248 nm KrF laser

"© 2018 Optical Society of America. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibited"[EN] This paper presents fiber Bragg grating (FBG) inscription with a pulsed 248 nm UV KrF laser in polymer optical fibers (POFs) made of different polymers, namely polymethyl methacrylate (PMMA), cyclic-olefin polymer and co-polymer, and Polycarbonate. The inscribed gratings and the corresponding inscription parameters are compared with grating inscribed in POFs made of the aforementioned materials but with the hitherto most used laser for inscription, which is a continuous wave 325 nm UV HeCd laser. Results show a reduction of the inscription time of at least 16 times. The maximum time reduction is more than 130 times. In addition, a reflectivity and a bandwidth close to or higher than the ones with the 325 nm laser were obtained. The polymer optical fiber Bragg gratings (POFBGs) inscribed with the 248 nm laser setup present high stability with small variations in their central wavelength, bandwidth, and reflectivity after 40 days. (c) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement.Fundacao para Ciencia e a Tecnologia (FCT) (SFRH/BPD/109458/2015, UID/EEA/50008/2013).Marques, C.; Min, R.; Leal-Junior, A.; Antunes, P.; Fasano, A.; Woyessa, G.; Nielsen, K.... (2018). Fast and stable gratings inscription in POFs made of different materials with pulsed 248 nm KrF laser. Optics Express. 26(2):2013-2022. https://doi.org/10.1364/OE.26.002013S20132022262Webb, D. J. (2015). Fibre Bragg grating sensors in polymer optical fibres. Measurement Science and Technology, 26(9), 092004. doi:10.1088/0957-0233/26/9/092004Prado, A. R., Leal-Junior, A. G., Marques, C., Leite, S., de Sena, G. L., Machado, L. C., … Pontes, M. J. (2017). Polymethyl methacrylate (PMMA) recycling for the production of optical fiber sensor systems. Optics Express, 25(24), 30051. doi:10.1364/oe.25.030051Hu, X., Saez-Rodriguez, D., Marques, C., Bang, O., Webb, D. J., Mégret, P., & Caucheteur, C. (2015). Polarization effects in polymer FBGs: study and use for transverse force sensing. Optics Express, 23(4), 4581. doi:10.1364/oe.23.004581Pospori, A., Marques, C. A. F., Bang, O., Webb, D. J., & André, P. (2017). Polymer optical fiber Bragg grating inscription with a single UV laser pulse. Optics Express, 25(8), 9028. doi:10.1364/oe.25.009028Marques, C. A. F., Webb, D. J., & Andre, P. (2017). Polymer optical fiber sensors in human life safety. Optical Fiber Technology, 36, 144-154. doi:10.1016/j.yofte.2017.03.010Fasano, A., Woyessa, G., Janting, J., Rasmussen, H. K., & Bang, O. (2017). Solution-Mediated Annealing of Polymer Optical Fiber Bragg Gratings at Room Temperature. IEEE Photonics Technology Letters, 29(8), 687-690. doi:10.1109/lpt.2017.2678481Woyessa, G., Pedersen, J. K. M., Fasano, A., Nielsen, K., Markos, C., Rasmussen, H. K., & Bang, O. (2017). Zeonex-PMMA microstructured polymer optical FBGs for simultaneous humidity and temperature sensing. Optics Letters, 42(6), 1161. doi:10.1364/ol.42.001161Fasano, A., Woyessa, G., Stajanca, P., Markos, C., Stefani, A., Nielsen, K., … Bang, O. (2016). Fabrication and characterization of polycarbonate microstructured polymer optical fibers for high-temperature-resistant fiber Bragg grating strain sensors. Optical Materials Express, 6(2), 649. doi:10.1364/ome.6.000649Woyessa, G., Nielsen, K., Stefani, A., Markos, C., & Bang, O. (2016). Temperature insensitive hysteresis free highly sensitive polymer optical fiber Bragg grating humidity sensor. Optics Express, 24(2), 1206. doi:10.1364/oe.24.001206Leal-Junior, A. G., Frizera, A., & José Pontes, M. (2018). Sensitive zone parameters and curvature radius evaluation for polymer optical fiber curvature sensors. Optics & Laser Technology, 100, 272-281. doi:10.1016/j.optlastec.2017.10.006Stefani, A., Andresen, S., Yuan, W., Herholdt-Rasmussen, N., & Bang, O. (2012). High Sensitivity Polymer Optical Fiber-Bragg-Grating-Based Accelerometer. IEEE Photonics Technology Letters, 24(9), 763-765. doi:10.1109/lpt.2012.2188024Marques, C. A. F., Peng, G.-D., & Webb, D. J. (2015). Highly sensitive liquid level monitoring system utilizing polymer fiber Bragg gratings. Optics Express, 23(5), 6058. doi:10.1364/oe.23.006058Jensen, J. B., Hoiby, P. E., Emiliyanov, G., Bang, O., Pedersen, L. H., & Bjarklev, A. (2005). Selective detection of antibodies in microstructured polymer optical fibers. Optics Express, 13(15), 5883. doi:10.1364/opex.13.005883Emiliyanov, G., Høiby, P., Pedersen, L., & Bang, O. (2013). Selective Serial Multi-Antibody Biosensing with TOPAS Microstructured Polymer Optical Fibers. Sensors, 13(3), 3242-3251. doi:10.3390/s130303242Hassan, H. U., Janting, J., Aasmul, S., & Bang, O. (2016). Polymer Optical Fiber Compound Parabolic Concentrator fiber tip based glucose sensor: in-Vitro Testing. IEEE Sensors Journal, 1-1. doi:10.1109/jsen.2016.2606580Yuan, W., Khan, L., Webb, D. J., Kalli, K., Rasmussen, H. K., Stefani, A., & Bang, O. (2011). Humidity insensitive TOPAS polymer fiber Bragg grating sensor. Optics Express, 19(20), 19731. doi:10.1364/oe.19.019731Johnson, I. P., Yuan, W., Stefani, A., Nielsen, K., Rasmussen, H. K., Khan, L., … Bang, O. (2011). Optical fibre Bragg grating recorded in TOPAS cyclic olefin copolymer. Electronics Letters, 47(4), 271. doi:10.1049/el.2010.7347Markos, C., Stefani, A., Nielsen, K., Rasmussen, H. K., Yuan, W., & Bang, O. (2013). High-T_g TOPAS microstructured polymer optical fiber for fiber Bragg grating strain sensing at 110 degrees. Optics Express, 21(4), 4758. doi:10.1364/oe.21.004758Woyessa, G., Fasano, A., Stefani, A., Markos, C., Nielsen, K., Rasmussen, H. K., & Bang, O. (2016). Single mode step-index polymer optical fiber for humidity insensitive high temperature fiber Bragg grating sensors. Optics Express, 24(2), 1253. doi:10.1364/oe.24.001253Woyessa, G., Fasano, A., Markos, C., Stefani, A., Rasmussen, H. K., & Bang, O. (2016). Zeonex microstructured polymer optical fiber: fabrication friendly fibers for high temperature and humidity insensitive Bragg grating sensing. Optical Materials Express, 7(1), 286. doi:10.1364/ome.7.000286Stefani, A., Nielsen, K., Rasmussen, H. K., & Bang, O. (2012). Cleaving of TOPAS and PMMA microstructured polymer optical fibers: Core-shift and statistical quality optimization. Optics Communications, 285(7), 1825-1833. doi:10.1016/j.optcom.2011.12.033Nielsen, K., Rasmussen, H. K., Adam, A. J., Planken, P. C., Bang, O., & Jepsen, P. U. (2009). Bendable, low-loss Topas fibers for the terahertz frequency range. Optics Express, 17(10), 8592. doi:10.1364/oe.17.008592Nielsen, K., Rasmussen, H. K., Jepsen, P. U., & Bang, O. (2010). Broadband terahertz fiber directional coupler. Optics Letters, 35(17), 2879. doi:10.1364/ol.35.002879Anthony, J., Leonhardt, R., Argyros, A., & Large, M. C. J. (2011). Characterization of a microstructured Zeonex terahertz fiber. Journal of the Optical Society of America B, 28(5), 1013. doi:10.1364/josab.28.001013Woyessa, G., Fasano, A., Markos, C., Rasmussen, H. K., & Bang, O. (2017). Low Loss Polycarbonate Polymer Optical Fiber for High Temperature FBG Humidity Sensing. IEEE Photonics Technology Letters, 29(7), 575-578. doi:10.1109/lpt.2017.2668524Johnson, I. P., Kalli, K., & Webb, D. J. (2010). 827 nm Bragg grating sensor in multimode microstructured polymer optical fibre. Electronics Letters, 46(17), 1217. doi:10.1049/el.2010.1595Stefani, A., Wu Yuan, Markos, C., & Bang, O. (2011). Narrow Bandwidth 850-nm Fiber Bragg Gratings in Few-Mode Polymer Optical Fibers. IEEE Photonics Technology Letters, 23(10), 660-662. doi:10.1109/lpt.2011.2125786Hu, X., Pun, C.-F. J., Tam, H.-Y., Mégret, P., & Caucheteur, C. (2014). Highly reflective Bragg gratings in slightly etched step-index polymer optical fiber. Optics Express, 22(15), 18807. doi:10.1364/oe.22.018807Hu, X., Pun, C.-F. J., Tam, H.-Y., Mégret, P., & Caucheteur, C. (2014). Tilted Bragg gratings in step-index polymer optical fiber. Optics Letters, 39(24), 6835. doi:10.1364/ol.39.006835Sáez-Rodríguez, D., Nielsen, K., Rasmussen, H. K., Bang, O., & Webb, D. J. (2013). Highly photosensitive polymethyl methacrylate microstructured polymer optical fiber with doped core. Optics Letters, 38(19), 3769. doi:10.1364/ol.38.003769Hu, X., Woyessa, G., Kinet, D., Janting, J., Nielsen, K., Bang, O., & Caucheteur, C. (2017). BDK-doped core microstructured PMMA optical fiber for effective Bragg grating photo-inscription. Optics Letters, 42(11), 2209. doi:10.1364/ol.42.002209Statkiewicz-Barabach, G., Kowal, D., Mergo, P., & Urbanczyk, W. (2015). Comparison of growth dynamics and temporal stability of Bragg gratings written in polymer fibers of different types. Journal of Optics, 17(8), 085606. doi:10.1088/2040-8978/17/8/085606Marques, C., Pospori, A., Demirci, G., Çetinkaya, O., Gawdzik, B., Antunes, P., … Webb, D. (2017). Fast Bragg Grating Inscription in PMMA Polymer Optical Fibres: Impact of Thermal Pre-Treatment of Preforms. Sensors, 17(4), 891. doi:10.3390/s17040891Bundalo, I.-L., Nielsen, K., Markos, C., & Bang, O. (2014). Bragg grating writing in PMMA microstructured polymer optical fibers in less than 7 minutes. Optics Express, 22(5), 5270. doi:10.1364/oe.22.005270Oliveira, R., Bilro, L., & Nogueira, R. (2015). Bragg gratings in a few mode microstructured polymer optical fiber in less than 30 seconds. Optics Express, 23(8), 10181. doi:10.1364/oe.23.010181Lacraz, A., Polis, M., Theodosiou, A., Koutsides, C., & Kalli, K. (2015). Femtosecond Laser Inscribed Bragg Gratings in Low Loss CYTOP Polymer Optical Fiber. IEEE Photonics Technology Letters, 27(7), 693-696. doi:10.1109/lpt.2014.2386692Theodosiou, A., Lacraz, A., Stassis, A., Koutsides, C., Komodromos, M., & Kalli, K. (2017). Plane-by-Plane Femtosecond Laser Inscription Method for Single-Peak Bragg Gratings in Multimode CYTOP Polymer Optical Fiber. Journal of Lightwave Technology, 35(24), 5404-5410. doi:10.1109/jlt.2017.2776862Yuan, W., Stefani, A., Bache, M., Jacobsen, T., Rose, B., Herholdt-Rasmussen, N., … Bang, O. (2011). Improved thermal and strain performance of annealed polymer optical fiber Bragg gratings. Optics Communications, 284(1), 176-182. doi:10.1016/j.optcom.2010.08.069Bundalo, I.-L., Nielsen, K., Woyessa, G., & Bang, O. (2017). Long-term strain response of polymer optical fiber FBG sensors. Optical Materials Express, 7(3), 967. doi:10.1364/ome.7.00096

25-hydroxyvitamin D concentration is inversely associated with serum MMP-9 in a cross-sectional study of African American ESRD patients

BACKGROUND: Circulating 25-hydroxyvitamin D [25(OH)D] concentration is inversely associated with peripheral arterial disease and hypertension. Vascular remodeling may play a role in this association, however, data relating vitamin D level to specific remodeling biomarkers among ESRD patients is sparse. We tested whether 25(OH)D concentration is associated with markers of vascular remodeling and inflammation in African American ESRD patients.METHODS: We conducted a cross-sectional study among ESRD patients receiving maintenance hemodialysis within Emory University-affiliated outpatient hemodialysis units. Demographic, clinical and dialysis treatment data were collected via direct patient interview and review of patients records at the time of enrollment, and each patient gave blood samples. Associations between 25(OH)D and biomarker concentrations were estimated in univariate analyses using Pearson's correlation coefficients and in multivariate analyses using linear regression models. 25(OH) D concentration was entered in multivariate linear regression models as a continuous variable and binary variable (<15 ng/ml and =15 ng/ml). Adjusted estimate concentrations of biomarkers were compared between 25(OH) D groups using analysis of variance (ANOVA). Finally, results were stratified by vascular access type.RESULTS: Among 91 patients, mean (standard deviation) 25(OH)D concentration was 18.8 (9.6) ng/ml, and was low (<15 ng/ml) in 43% of patients. In univariate analyses, low 25(OH) D was associated with lower serum calcium, higher serum phosphorus, and higher LDL concentrations. 25(OH) D concentration was inversely correlated with MMP-9 concentration (r = -0.29, p = 0.004). In multivariate analyses, MMP-9 concentration remained negatively associated with 25(OH) D concentration (P = 0.03) and anti-inflammatory IL-10 concentration positively correlated with 25(OH) D concentration (P = 0.04).CONCLUSIONS: Plasma MMP-9 and circulating 25(OH) D concentrations are significantly and inversely associated among ESRD patients. This finding may suggest a potential mechanism by which low circulating 25(OH) D functions as a cardiovascular risk factor

25-hydroxyvitamin D concentration is inversely associated with serum MMP-9 in a cross-sectional study of African American ESRD patients

BACKGROUND: Circulating 25-hydroxyvitamin D [25(OH)D] concentration is inversely associated with peripheral arterial disease and hypertension. Vascular remodeling may play a role in this association, however, data relating vitamin D level to specific remodeling biomarkers among ESRD patients is sparse. We tested whether 25(OH)D concentration is associated with markers of vascular remodeling and inflammation in African American ESRD patients.METHODS: We conducted a cross-sectional study among ESRD patients receiving maintenance hemodialysis within Emory University-affiliated outpatient hemodialysis units. Demographic, clinical and dialysis treatment data were collected via direct patient interview and review of patients records at the time of enrollment, and each patient gave blood samples. Associations between 25(OH)D and biomarker concentrations were estimated in univariate analyses using Pearson's correlation coefficients and in multivariate analyses using linear regression models. 25(OH) D concentration was entered in multivariate linear regression models as a continuous variable and binary variable (<15 ng/ml and =15 ng/ml). Adjusted estimate concentrations of biomarkers were compared between 25(OH) D groups using analysis of variance (ANOVA). Finally, results were stratified by vascular access type.RESULTS: Among 91 patients, mean (standard deviation) 25(OH)D concentration was 18.8 (9.6) ng/ml, and was low (<15 ng/ml) in 43% of patients. In univariate analyses, low 25(OH) D was associated with lower serum calcium, higher serum phosphorus, and higher LDL concentrations. 25(OH) D concentration was inversely correlated with MMP-9 concentration (r = -0.29, p = 0.004). In multivariate analyses, MMP-9 concentration remained negatively associated with 25(OH) D concentration (P = 0.03) and anti-inflammatory IL-10 concentration positively correlated with 25(OH) D concentration (P = 0.04).CONCLUSIONS: Plasma MMP-9 and circulating 25(OH) D concentrations are significantly and inversely associated among ESRD patients. This finding may suggest a potential mechanism by which low circulating 25(OH) D functions as a cardiovascular risk factor

Spatial transcriptomics unveils ZBTB11 as a regulator of cardiomyocyte degeneration in arrhythmogenic cardiomyopathy

AIMS: Arrhythmogenic cardiomyopathy (ACM) is an inherited cardiac disorder that is characterized by progressive loss of myocardium that is replaced by fibro-fatty cells, arrhythmias, and sudden cardiac death. While myocardial degeneration and fibro-fatty replacement occur in specific locations, the underlying molecular changes remain poorly characterized. Here we aim to delineate local changes in gene expression to identify new genes and pathways that are relevant for specific remodelling processes occurring during ACM. METHODS AND RESULTS: Using Tomo-Seq, genome-wide transcriptional profiling with high spatial resolution, we created transmural epicardial to endocardial gene expression atlases of explanted ACM hearts to gain molecular insights into disease-driving processes. This enabled us to link gene expression profiles to the different regional remodelling responses and allowed us to identify genes that are potentially relevant for disease progression. In doing so, we identified distinct gene expression profiles marking regions of cardiomyocyte degeneration and fibro-fatty remodelling and revealed Zinc finger and BTB domain-containing protein 11 (ZBTB11) to be specifically enriched at sites of active fibro-fatty replacement of myocardium. Immunohistochemistry indicated ZBTB11 to be induced in cardiomyocytes flanking fibro-fatty areas, which could be confirmed in multiple cardiomyopathy patients. Forced overexpression of ZBTB11 induced autophagy and cell death-related gene programs in human cardiomyocytes, leading to increased apoptosis. CONCLUSIONS: Our study shows the power of Tomo-Seq to unveil new molecular mechanisms in human cardiomyopathy and uncovers ZBTB11 as a novel driver of cardiomyocyte loss

Islet Endothelial Activation and Oxidative Stress Gene Expression Is Reduced by IL-1Ra Treatment in the Type 2 Diabetic GK Rat

Inflammation followed by fibrosis is a component of islet dysfunction in both rodent and human type 2 diabetes. Because islet inflammation may originate from endothelial cells, we assessed the expression of selected genes involved in endothelial cell activation in islets from a spontaneous model of type 2 diabetes, the Goto-Kakizaki (GK) rat. We also examined islet endotheliuml/oxidative stress (OS)/inflammation-related gene expression, islet vascularization and fibrosis after treatment with the interleukin-1 (IL-1) receptor antagonist (IL-1Ra)

The Role of p300 Histone Acetyltransferase in UV-Induced Histone Modifications and MMP-1 Gene Transcription

Matrix metalloproteinase (MMP)-1 promotes ultraviolet (UV)-triggered long-term detrimental effects such as cancer formation and premature skin aging. Although histone modifications may play a crucial role in the transcriptional regulation of MMP-1, the relationship between UV-induced histone modification and MMP-1 expression is not completely understood. Here, we identify regulators of histone acetylation that may link UV-mediated DNA damage and MMP-1 induction by UV in cultured human dermal fibroblasts (HDFs) in vitro. UV irradiation of HDFs induced MMP-1 expression and increased the level of phosphorylation of H2AX (γ-H2AX), p53 and the acetylation of histone H3 (acetyl-H3). Total histone deacetylase (HDAC) enzymatic activity was decreased by UV irradiation, while histone acetyltransferase (HAT) activity was increased. Suppression of p300 histone acetyltransferase (p300HAT) activity by the p300HAT inhibitor anacardic acid (AA) or by down-regulation of p300 by siRNA prevented UV-induced MMP-1 expression and inhibited UV-enhanced γ-H2AX, p53 level, and acetyl-H3. Using chromatin immunoprecipitation assays, we observed that γ-H2AX, p53, acetyl-H3, p300 and c-Jun were consistently recruited by UV to a distinct region (−2067/−1768) adjacent to the p300 binding site (−1858/−1845) in the MMP-1 promoter. In addition, these recruitments of γ-H2AX, p53, acetyl-H3, p300 and c-Jun to the p300-2 site were significantly abrogated by post-treatment with AA. Furthermore, overexpression of p300 increased the basal and UV-induced MMP-1 promoter activity. Our results suggest that p300HAT plays a critical role in the transcriptional regulation of MMP-1 by UV