187 research outputs found

    Non-covalent functionalized SWNTs as delivery agents for novel Bodipy-based potential PDT sensitizers

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    Pyrenyl-functionalized distyryl-Bodipy sensitizer attached non-covalently to SWNTs was shown to generate singlet oxygen when excited at 660 nm with a red LED array; this work emphasizes the potential of SWNT as a viable alternative carrier of bioactive agents, including photodynamic therapy sensitizers. © 2009 The Royal Society of Chemistry

    Wideband 'black silicon' for mid-infrared applications

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    In this paper, we investigate the absorption of mid-infrared light by low resistivity silicon textured via deep reactive ion etching. An analytical description of the wave propagation in black silicon texture is presented, showing agreement with the experiment and the computational analysis. We also study the dependence of absorption spectrum of black silicon structure on the electrical conductivity of silicon substrate. The structures investigated unveil wideband, all-silicon infrared absorbers applicable for infrared imaging and spectroscopy with simple CMOS compatible fabrication suitable for optoelectronic integration. © 2017 IOP Publishing Ltd

    LWIR all-atomic layer deposition ZnO bilayer microbolometer for thermal imaging

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    We propose an all-ZnO bilayer microbolometer, operating in the long-wave infrared regime that can be implemented by consecutive atomic layer deposition growth steps. Bilayer design of the bolometer provides very high absorption coefficients compared to the same thickness of a single ZnO layer. High absorptivity of the bilayer structure enables higher performance (lower noise equivalent temperature difference and time constant values) compared to single-layer structure. We observe these results computationally by conducting both optical and thermal simulations. © 2017 Society of Photo-Optical Instrumentation Engineers (SPIE)

    High-conductivity silicon based spectrally selective plasmonic surfaces for sensing in the infrared region

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    Plasmonic perfect absorbers have found a wide range of applications in imaging, sensing, and light harvesting and emitting devices. Traditionally, metals are used to implement plasmonic structures. For sensing applications, it is desirable to integrate nanophotonic active surfaces with biasing and amplification circuitry to achieve monolithic low cost solutions. Commonly used plasmonic metals such as Au and Ag are not compatible with standard silicon complementary metal-oxide-semiconductor (CMOS) technology. Here we demonstrate plasmonic perfect absorbers based on high conductivity silicon. Standard optical lithography and reactive ion etching techniques were used for the patterning of the samples. We present computational and experimental results of surface plasmon resonances excited on a silicon surface at normal and oblique incidences. We experimentally demonstrate our absorbers as ultra-low cost, CMOS-compatible and efficient refractive index sensing surfaces. The experimental results reveal that the structure exhibits a sensitivity of around 11 000 nm/RIU and a figure of merit of up to 2.5. We also show that the sensing performance of the structure can be improved by increasing doping density. � 2016 IOP Publishing Ltd

    All-Silicon Ultra-Broadband Infrared Light Absorbers

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    Absorbing infrared radiation efficiently is important for critical applications such as thermal imaging and infrared spectroscopy. Common infrared absorbing materials are not standard in Si VLSI technology. We demonstrate ultra-broadband mid-infrared absorbers based purely on silicon. Broadband absorption is achieved by the combined effects of free carrier absorption, and vibrational and plasmonic absorption resonances. The absorbers, consisting of periodically arranged silicon gratings, can be fabricated using standard optical lithography and deep reactive ion etching techniques, allowing for cost-effective and wafer-scale fabrication of micro-structures. Absorption wavebands in excess of 15 micrometers (5-20 μm) are demonstrated with more than 90% average absorptivity. The structures also exhibit broadband absorption performance even at large angles of incidence (θ = 50°), and independent of polarization. © 2016 The Author(s)

    A specific case in the classification of woods by FTIR and chemometric: discrimination of Fagales from Malpighiales

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    Fourier transform infrared (FTIR) spectroscopic data was used to classify wood samples from nine species within the Fagales and Malpighiales using a range of multivariate statistical methods. Taxonomic classification of the family Fagaceae and Betulaceae from Angiosperm Phylogenetic System Classification (APG II System) was successfully performed using supervised pattern recognition techniques. A methodology for wood sample discrimination was developed using both sapwood and heartwood samples. Ten and eight biomarkers emerged from the dataset to discriminate order and family, respectively. In the species studied FTIR in combination with multivariate analysis highlighted significant chemical differences in hemicelluloses, cellulose and guaiacyl (lignin) and shows promise as a suitable approach for wood sample classification

    A combination of left ventricular noncompaction and double orifice mitral valve

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    A 24-year-old woman admitted with mild chest distress associated with activity without chest complaint for twenty days. Two orifices were visible at the level of the mitral valve with a transthoracic short-axis view of the two-dimensional and three-dimensional echocardiography. The left ventricle was mildly dilatated and the left ventricular wall was thickened, especially at the apex and anterolateral wall, and appeared sponge-like. There were numerous, excessively prominent trabeculations associated with intertrabecular recesses. Although the coexistence of NVM and DOMV could be a coincidence, we believe that both defects were probably caused by a developmental arrest of the left ventricular myocardium in the present case

    TCT-170 Development and Validation of a Scoring System for Predicting Clinical Coronary Artery Perforation During Percutaneous Coronary Interventions of Chronic Total Occlusions: The PROGRESS-CTO Perforation Score

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    Background: Coronary artery perforation is a feared complication of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) and often leads to serious adverse clinical events. Methods: We analyzed clinical and angiographic parameters from 9,618 CTO PCIs in the PROGRESS-CTO (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention). Logistic regression prediction modeling was used to identify independently associated variables, and models were internally validated with bootstrapping. Clinical coronary artery perforation was defined as any perforation requiring treatment. Results: The incidence of clinical coronary perforation was 3.8% (n = 367). Five factors were independently associated with perforation and were included in the score: patient age ≥ 65 years, +1 point (OR: 1.79; 95% CI: 1.37-2.33); moderate or severe calcification, +1 point (OR: 1.85; 95% CI: 1.41-2.42); blunt or no stump, +1 point (OR: 1.45; 95% CI: 1.10-1.92); use of antegrade dissection and re-entry strategy, +1 point (OR: 2.43; 95% CI: 1.61-3.69); and use of the retrograde approach, +2 points (OR: 4.02; 95% CI: 2.95-5.46). The resulting score showed acceptable performance on receiver-operating characteristic curve (area under the curve: 0.741; 95% CI: 0.712-0.773). The Hosmer-Lemeshow test indicated good fitness (P = 0.991), and internal validation with bootstrapping demonstrated a good agreement with the model (observed area under the curve: 0.736; 95% bias-corrected CI: 0.706-0.767). Conclusions: The PROGRESS-CTO perforation score is a useful tool for prediction of clinical coronary perforation in CTO PCI. Categories: CORONARY: Complex and Higher Risk Procedures for Indicated Patients (CHIP

    Toll-like receptor 9 and the inflammatory response to surgical trauma and cardiopulmonary bypass

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    Objectives Cardiac surgery can lead to post-operative end-organ complications secondary to activation of systemic inflammatory response. We hypothesize that surgical trauma or cardiopulmonary bypass (CPB) may initiate systemic inflammatory response via release of mitochondrial DNA (mtDNA) signaling Toll-like receptor 9 (TLR9) and interleukin-6 production (IL-6). Materials and methods The role of TLR9 in systemic inflammatory response in cardiac surgery was studied using a murine model of sternotomy and a porcine model of sternotomy and CPB. mtDNA and IL-6 were measured with and without TLR9-antagonist treatment. To study ischemia-reperfusion injury, we utilized an ex-vivo porcine kidney model. Results In the rodent model (n = 15), circulating mtDNA increased 19-fold (19.29 ± 3.31, p < 0.001) and plasma IL-6 levels increased 59-fold (59.06 ± 14.98) at 1-min post-sternotomy compared to pre-sternotomy. In the murine model (n = 11), administration of TLR-9 antagonists lowered IL-6 expression post-sternotomy when compared to controls (59.06 ± 14.98 vs. 5.25 ± 1.08) indicating that TLR-9 is a positive regulator of IL-6 after sternotomy. Using porcine models (n = 10), a significant increase in circulating mtDNA was observed after CPB (Fold change 29.9 ± 4.8, p = 0.005) and along with IL-6 following renal ischaemia-reperfusion. Addition of the antioxidant sulforaphane reduced circulating mtDNA when compared to controls (FC 7.36 ± 0.61 vs. 32.0 ± 4.17 at 60 min post-CPB). Conclusion CPB, surgical trauma and ischemic perfusion injury trigger the release of circulating mtDNA that activates TLR-9, in turn stimulating a release of IL-6. Therefore, TLR-9 antagonists may attenuate this response and may provide a future therapeutic target whereby the systemic inflammatory response to cardiac surgery may be manipulated to improve clinical outcomes
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