18 research outputs found
Ultra-Broadband Infrared Absorption by Tapered Hyperbolic Multilayer Waveguides
Ultra-broadband strong absorption over 92% covering the infrared wavelength range of 1 ~ 6μm is demonstrated by using the tapered hyperbolic Au-SiO2 multilayer waveguides on glass substrates. Such broadband absorption is formed by the stop-light modes at various wavelengths located at different waveguide widths. A planar hyperbolic waveguide model is built to determine the stop-light modes by considering both forward and backward guided modes. The stop-light modes located inside the Au-SiO2 multilayer waveguide are simulated at the absorption peaks by reducing the Au loss. Tapered multilayer waveguides with varying top widths are further simulated, fabricated and measured, indicating the almost linear relation between the waveguide width and the stop-light wavelength. Moreover, the broadband absorption of tapered waveguide is proved to be angle-insensitive and polarization-independent, and the heat generation and temperature increase are also discussed
Experimental realization of epsilon-near-zero metamaterial slabs with metal-dielectric multilayers
Epsilon-near-zero (ENZ) metamaterial slabs at visible frequencies based on
metal-dielectric multilayers are experimentally realized. Transmission,
reflection and absorption spectra are measured and used to determine the
complex refractive indices and the effective permittivities of the ENZ slabs,
which agree with the results obtained from both the numerical simulations and
the optical nonlocalities analysis. Furthermore, light propagation in ENZ slabs
and directional emission from ENZ prisms are also analyzed. The accurate
determination of the ENZ wavelength for metal-dielectric multilayer
metamaterial slabs is important for realizing many unique applications, such as
phase front manipulation and enhancement of photonic density of states.Comment: 9 pages, 5 figure
A Combined Surface Chemistry / Microwell Approach for Trapping Single Cells on Electrochemical Microelectrodes for Measurement of Quantal Exocytosis
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Ultrasensitive detection of lipoarabinomannan with plasmonic grating biosensors in clinical samples of HIV negative patients with tuberculosis.
BACKGROUND:Timely diagnosis of tuberculosis disease is critical for positive patient outcomes, yet potentially millions go undiagnosed or unreported each year. Sputum is widely used as the testing input, but limited by its complexity, heterogeneity, and sourcing problems. Finding methods to interrogate noninvasive, non-sputum clinical specimens is indispensable to improving access to tuberculosis diagnosis and care. In this work, economical plasmonic gratings were used to analyze tuberculosis biomarker lipoarabinomannan (LAM) from clinical urine samples by single molecule fluorescence assay (FLISA) and compared with gold standard sputum GeneXpert MTB/ RIF, culture, and reference ELISA testing results. METHODS AND FINDINGS:In this study, twenty sputum and urine sample sets were selected retrospectively from a repository of HIV-negative patient samples collected before initiation of anti-tuberculosis therapy. GeneXpert MTB/RIF and culture testing of patient sputum confirmed the presence or absence of pulmonary tuberculosis while all patient urines were reference ELISA LAM-negative. Plasmonic gratings produced by low-cost soft lithography were bound with anti-LAM capture antibody, incubated with patient urine samples, and biotinylated detection antibody. Fluorescently labeled streptavidin revealed single molecule emission by epifluorescence microscope. Using a 1 fg/mL baseline for limit of detection, single molecule FLISA demonstrated good qualitative agreement with gold standard tests on 19 of 20 patients, including accurately predicting the gold-standard-negative patients, while one gold-standard-positive patient produced no observable LAM in urine. CONCLUSIONS:Single molecule FLISA by plasmonic grating demonstrated the ability to quantify tuberculosis LAM from complex urine samples of patients from a high endemic setting with negligible interference from the complex media itself. Moreover, agreement with patient diagnoses by gold standard testing suggests that single molecule FLISA could be used as a highly sensitive test to diagnose tuberculosis noninvasively
Laser-Scribed Conductive, Photoactive Transition Metal Oxide on Soft Elastomers for Janus On-Skin Electronics and Soft Actuators
Laser-assisted fabrication of conductive materials on flexible substrates has attracted intense interests because of its simplicity, easy customization, and broad applications. However, it remains challenging to achieve laser scribing of conductive materials on tissue-like soft elastomers, which can serve as the basis to construct bioelectronics and soft actuators. Here, we report laser scribing of metallic conductive, photoactive transition metal oxide (molybdenum dioxide) on soft elastomers, coated with molybdenum chloride precursors, under ambient conditions. Laser-scribed molybdenum dioxide (LSM) exhibits high electrical conductivity, biocompatibility, chemical stability, and compatibility with magnetic resonance imaging. In addition, LSM can be made on various substrates (polyimide, glass, and hair), showing high generality. Furthermore, LSM-based Janus on-skin electronics are developed to record information from human skin, human breath, and environments. Taking advantage of its outstanding photothermal effect, LSM-based soft actuators are developed to build light-driven reconfigurable three-dimensional architectures, reshapable airflow sensors, and smart robotic worms with bioelectronic sensors
Laser-Scribed Conductive, Photoactive Transition Metal Oxide on Soft Elastomers for Janus On-Skin Electronics and Soft Actuators
Laser-assisted fabrication of conductive materials on flexible substrates has attracted intense interests because of its simplicity, easy customization, and broad applications. However, it remains challenging to achieve laser scribing of conductive materials on tissue-like soft elastomers, which can serve as the basis to construct bioelectronics and soft actuators. Here, we report laser scribing of metallic conductive, photoactive transition metal oxide (molybdenum dioxide) on soft elastomers, coated with molybdenum chloride precursors, under ambient conditions. Laser-scribed molybdenum dioxide (LSM) exhibits high electrical conductivity, biocompatibility, chemical stability, and compatibility with magnetic resonance imaging. In addition, LSM can be made on various substrates (polyimide, glass, and hair), showing high generality. Furthermore, LSM-based Janus on-skin electronics are developed to record information from human skin, human breath, and environments. Taking advantage of its outstanding photothermal effect, LSM-based soft actuators are developed to build light-driven reconfigurable three-dimensional architectures, reshapable airflow sensors, and smart robotic worms with bioelectronic sensors
Significance of Salmonella typhi bacteriuria.
Bacteriuria due to Salmonella typhi usually occurs following recent typhoid fever or in chronic carrier states. Data from 18 patients with S. typhi bacteriuria, seen during 5 years, were analyzed. Fourteen patients had localized urinary tract infection due to S. typhi. Four others had bacteriuria, probably associated with typhoid fever. Localized abnormalities of the urinary tract and kidneys and also systemic diseases were found to predispose patients to S. typhi bacteriuria. Local abnormalities encountered included urolithiasis (n = 3), prostatic hypertrophy (n = 1), and tuberculosis (n = 1). One renal transplant recipient and another with lupus nephritis had S. typhi bacteriuria. One had associated strongyloidosis, and another was pregnant
Spontaneous Emission Rate Enhancement with Aperiodic Thue-Morse Multilayer
The emergence of multilayer metamaterials in the research field of enhancing spontaneous emission rates has recently received extensive attention. Previous research efforts mostly focus on periodic metal-dielectric multilayers in hyperbolic dispersion region; however, the influence of lattice order in subwavelength multilayers on spontaneous emission is rarely studied. Here, we observe the stronger Purcell enhancement of quantum dots coupled to the aperiodic metal-dielectric multilayer with Thue-Morse lattice order from elliptical to hyperbolic dispersion regions, compared to the periodic multilayer with the same metal filling ratio. This work demonstrates the potential of utilizing quasiperiodic metamaterial nanostructures to engineer the local density of states for various nanophotonic applications
Comparison of the efficacy of cardamom (Elettaria cardamomum) with pioglitazone on dexamethasone-induced hepatic steatosis, dyslipidemia, and hyperglycemia in albino rats
To evaluate the efficacy of cardamom with pioglitazone on dexamethasone-induced hepatic steatosis, dyslipidemia, and hyperglycemia in albino rats. There were four groups of 6 rats each. First group received dexamethasone alone in a dose of 8 mg/kg intraperitoneally for 6 days to induce metabolic changes and considered as dexamethasone control. Second group received cardamom suspension 1 g/kg/10 mL of 2% gum acacia orally 6 days before dexamethasone and 6 days during dexamethasone administration. Third group received pioglitazone 45 mg/kg orally 6 days before dexamethasone and 6 days during dexamethasone administration. Fourth group did not receive any medication and was considered as normal control. Fasting blood sugar, lipid profile, blood sugar 2 h after glucose load, liver weight, liver volume were recorded, and histopathological analysis was done. The effects of cardamom were compared with that of pioglitazone. Dexamethasone caused hepatomegaly, dyslipidemia and hyperglycemia. Both pioglitazone and cardamom significantly reduced hepatomegaly, dyslipidemia, and hyperglycemia (P < 0.01). Reduction of blood sugar levels after glucose load was significant with pioglitazone in comparison to cardamom (P < 0.01). Cardamom has comparable efficacy to pioglitazone in preventing dexamethasone-induced hepatomegaly, dyslipidemia, and fasting hyperglycemia