Search results for "GOLD"
showing 10 items of 1320 documents
Electron microscopic immunogold cytochemistry reveals chromogranin A confined to secretory granules of porcine Merkel cells
1990
By ultrastructural immunohistochemistry using the immunogold technique, immunoreactive (ir) Chromogranin A (CGA) was found to be confined to the secretory vesicles of porcine Merkel cells. CGA was present predominantly in the periphery of the electron-dense core and on the clear halo. These findings indicate that CGA is a regular constituent of Merkel cell secretory granules but probably not exclusively responsible for their electron opacity.
Development of novel probes for enterovirus B group to study uncoating and infection
2016
Enterovirus B group (EV-B) viruses are important human pathogens which cause a variety of diseases from mild respiratory illnesses to more severe acute infections such as myocarditis and meningitis. EV-Bs have also been associated with chronic infections and autoimmune diseases such as type I diabetes. Because of their significance, better and more accurate methods are necessary to track and visualize viruses in vitro and in vivo. This thesis focus on the development of novel probes to label viruses site-specifically and track infection in vitro. First, we established a covalent conjugation between gold nanocluster markers and EV-B viruses. We were able to visualize through electron microsc…
Reconfigurable DNA Origami Nanocapsule for pH-Controlled Encapsulation and Display of Cargo
2019
DNA nanotechnology provides a toolbox for creating custom and precise nanostructures with nanometer-level accuracy. These nano-objects are often static by nature and serve as versatile templates for assembling various molecular components in a user-defined way. In addition to the static structures, the intrinsic programmability of DNA nanostructures allows the design of dynamic devices that can perform predefined tasks when triggered with external stimuli, such as drug delivery vehicles whose cargo display or release can be triggered with a specified physical or chemical cue in the biological environment. Here, we present a DNA origami nanocapsule that can be loaded with cargo and reversibl…
On the use of unmanned aerial systems for environmental monitoring
2018
[EN] Environmental monitoring plays a central role in diagnosing climate and management impacts on natural and agricultural systems; enhancing the understanding of hydrological processes; optimizing the allocation and distribution of water resources; and assessing, forecasting, and even preventing natural disasters. Nowadays, most monitoring and data collection systems are based upon a combination of ground-based measurements, manned airborne sensors, and satellite observations. These data are utilized in describing both small-and large-scale processes, but have spatiotemporal constraints inherent to each respective collection system. Bridging the unique spatial and temporal divides that li…
What Contributes to the Measured Chiral Optical Response of the Glutathione-Protected Au25 Nanocluster?
2023
The water-soluble glutathione-protected [Au25(GSH)18]−1 nanocluster was investigated by integrating several methodologies such as molecular dynamics simulations, essential dynamics analysis, and state-of-the-art time-dependent density functional theory calculations. Fundamental aspects such as conformational, weak interactions and solvent effects, especially hydrogen-bonds, were included and found to play a fundamental role in assessing the optical response of this system. Our analysis demonstrated not only that the electronic circular dichroism is extremely sensitive to the solvent presence but also that the solvent itself plays an active role in the optical activity of such system, formin…
Electron Irradiation Effects on Single‐Layer MoS 2 Obtained by Gold‐Assisted Exfoliation
2022
International audience; Mechanical exfoliation assisted by gold is applied to obtain good quality large lateral size single-layer MoS2. The effects of 2.5 MeV electron irradiation are investigated at room temperature on structural and electronic features by Raman and microluminescence spectroscopy. The exciton recombination emission in the direct bandgap of single-layer MoS2 is affected during irradiation starting from the minimum explored dose of 1 kGy. At higher doses, Raman bands show no relevant modifications whereas the exciton emission is quenched, suggesting that irradiation-induced point defects affect exciton dynamics.
Synthesis and characterization of a novel high luminescent gold-2-mercapto-1-methyl-imidazole complex
2010
Synthesis and characterization of a new gold-2-mercapto-1-methyl imidazole are reported. This new organic material shows an extraordinary fluorescence activity (superfluorescence) up to 220°C with an unusual quantum yield of 0.2. Both fluorescence and NMR spectroscopy were applied to understand the behavior of the gold-2-mercapto-1-methylimidazole complex. Results suggest that the superfluorescence activity can be attributed to the shrinking of the HOMO-LUMO band gap energy following complexation of the organic imidazole system with gold. Copyright © 2010 John Wiley & Sons, Ltd.
The princely tomb of Lavau and the aristocracy of the Aube and the north of the Yonne in the 5th century BCE
2021
Computational Experiments with the Roots of Fibonacci-like Polynomials as a Window to Mathematics Research
2022
Fibonacci-like polynomials, the roots of which are responsible for a cyclic behavior of orbits of a second-order two-parametric difference equation, are considered. Using Maple and Wolfram Alpha, the location of the largest and the smallest roots responsible for the cycles of period p among the roots responsible for the cycles of periods 2kp (period-doubling) and kp (period-multiplying) has been determined. These purely computational results of experimental mathematics, made possible by the use of modern digital tools, can be used as a motivation for confirmation through not-yet-developed methods of formal mathematics. peerReviewed
Selective Recognition and Sensing of Succinate vs. Other Aliphatic Dicarboxylates by Thiourea-Functionalized Gold Nanoparticles
2016
Gold nanoparticles functionalized with thiourea moieties have been used as selective colorimetric sensors for the naked-eye detection of succinate versus other aliphatic dicarboxylates, all of them as their TBA salts. The detection process is based on the interparticle aggregation triggered by coordination of the end-carboxylates to the thiourea moieties of two different nanoparticles. This nanoparticle aggregation results in a batochromic shift of the plasmon resonance band and a visual color change from red to blue.