Spatially Resolved Spectroscopic Characterization of Nanostructured Films by Hyperspectral Dark-Field Microscopy

2021 ◽  
Author(s):  
Ziwei Liu ◽  
Chen Cai ◽  
Wengang Wu ◽  
Xinxia Cai ◽  
Zhi-mei Qi
Keyword(s):  
Spectroscopic Characterization ◽  
Dark Field ◽  
Nanostructured Films ◽  
Spatially Resolved ◽  
Dark Field Microscopy

Internalization of hyaluronan by chondrocytes occurs via receptor-mediated endocytosis

1993 ◽  
Vol 106 (1) ◽  
pp. 365-375 ◽  
Author(s):  
Q. Hua ◽  
C.B. Knudson ◽  
W. Knudson
Keyword(s):  
Cell Surface ◽  
Articular Chondrocytes ◽  
Dark Field ◽  
Cartilage Tissue ◽  
Receptor Mediated Endocytosis ◽  
Dark Field Microscopy ◽  
Bovine Articular Chondrocytes ◽  
Hyaluronan Receptors ◽  
Hyaluronan Receptor

Several studies have suggested that chondrocytes must have the capacity to internalize and degrade extracellular hyaluronan. In the present study we show direct evidence that hyaluronan is, in fact, endocytosed by chondrocytes and that the endocytosis is mediated via cell surface CD44/hyaluronan receptors. Cultures of bovine articular chondrocytes as well as rat chondrosarcoma chondrocytes were incubated with either fluorescein- or 3H-labeled hyaluronan. Intense binding and accumulation of labeled hyaluronan was visualized by fluorescence microscopy or bright-field/dark-field microscopy following autoradiography. Cell surface hyaluronan was removed with either trypsin or Streptomyces hyaluronidase in order to distinguish and quantify intracellular endocytosed hyaluronan. Labeled hyaluronan was visualized within small discrete intracellular vesicles distributed throughout the cytoplasm. Binding and endocytosis of fluorescein- or 3H-labeled hyaluronan was totally blocked by the addition of excess unlabeled hyaluronan or hyaluronan hexasaccharides, competitive inhibitors of hyaluronan/hyaluronan receptor interactions. Binding and endocytosis was also blocked by the addition of anti-CD44 monoclonal antibodies. Characterization of endocytosed 3H-labeled hyaluronan demonstrated that a significant portion of the hyaluronan was degraded by both the bovine articular and rat chondrosarcoma chondrocytes. Interestingly, a higher proportion of bound hyaluronan was internalized by the bovine chondrocytes. Therefore, hyaluronan receptor-mediated endocytosis and degradation of hyaluronan may provide a critical link to the maintenance and homeostasis of cartilage tissue.

Engineering and Characterization of Resonant Optical Antennas

2010 ◽  
Vol 1248 ◽  
Author(s):  
Matthias D. Wissert ◽  
Andreas W. Schell ◽  
Konstantin S. Ilin ◽  
M. Siegel ◽  
U. Lemmer ◽  
...  
Keyword(s):  
Electron Beam Lithography ◽  
Dark Field ◽  
Optical Antennas ◽  
Dipole Antennas ◽  
Split Ring ◽  
Dark Field Microscopy ◽  
Scattering Spectra ◽  
Coupled Structures ◽  
Spectral Redshift

AbstractResonant optical dipole antennas, consisting either of two arms coupled by a small gap or of a single, uncoupled arm only, are fabricated by the application of electron beam lithography and gold evaporation. Using dark-field microscopy, scattering spectra of structures with varied antenna arm length and varied gap size are obtained. The results show not only a spectral redshift for coupled structures compared to single arm structures, but also that the far-field scattering intensity is significantly higher for two arm structures with gap. In addition to the dipole structures, first fabrication results on quadrupole antennas and split-ring antennas are presented, offering novel pathways for an enhancement of the optical response function.

scholarly journals Plasmonic Photomobile Polymer Films

Crystals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 660
Author(s):  
Riccardo Castagna ◽  
Massimo Rippa ◽  
Francesco Simoni ◽  
Fulvia Villani ◽  
Giuseppe Nenna ◽  
...  
Keyword(s):  
Polymer Films ◽  
Localized Surface Plasmon Resonance ◽  
Dark Field ◽  
Localized Surface Plasmon ◽  
Force Microscopy ◽  
Atomic Force ◽  
Plasmonic Nanostructure ◽  
Dark Field Microscopy ◽  
Scanning Electron

In this work, we introduce the approaches currently followed to realize photomobile polymer films and remark on the main features of the system based on a biphasic structure recently proposed. We describe a method of making a plasmonic nanostructure on the surface of photomobile films. The characterization of the photomobile film is performed by means of Dark Field Microscopy (DFM), Scanning Electron Microscopy (SEM), and Atomic Force Microscopy (AFM). Preliminary observations of the light-induced effects on the Localized Surface Plasmon Resonance are also reported.

scholarly journals Fabrication and characterization of Au dimer antennas on glass pillars with enhanced plasmonic response

Nanophotonics ◽  
2017 ◽  
Vol 7 (2) ◽  
pp. 497-505 ◽  
Author(s):  
Pedram Sadeghi ◽  
Kaiyu Wu ◽  
Tomas Rindzevicius ◽  
Anja Boisen ◽  
Silvan Schmid
Keyword(s):  
Resonance Wavelength ◽  
Dark Field ◽  
Plasmonic Resonance ◽  
High Uniformity ◽  
Dark Field Microscopy ◽  
Scattering Spectra ◽  
Scattering Response ◽  
Difference Time ◽  
Microscopy Images

AbstractWe report on the fabrication and dark-field spectroscopy characterization of Au dimer nanoantennas placed on top of SiO2 nanopillars. The reported process enables the fabrication of nanopillar dimers with gaps down to 15 nm and heights up to 1 μm. A clear dependence of the plasmonic resonance position on the dimer gap is observed for smaller pillar heights, showing the high uniformity and reproducibility of the process. It is shown how increasing the height of nanopillars significantly affects the recorded elastic scattering spectra from Au nanoantennas. The results are compared to finite-difference time-domain (FDTD) and finite-element method (FEM) simulations. Additionally, measured spectra are accompanied by dark-field microscopy images of the dimers, showing the pronounced change in color. Placing nanoantennas on nanopillars with a height comparable to the in-plane dimer dimensions results in an enhancement of the scattering response, which can be understood through reduced interaction of the near-fields with the substrate. When increasing the pillar height further, scattering by the pillars themselves manifests itself as a strong tail at lower wavelengths. Additionally, strong directional scattering is expected as a result of the interface between the nanoantennas and nanopillars, which is taken into account in simulations. For pillars of height close to the plasmonic resonance wavelength, the scattering spectra become more complex due to additional scattering peaks as a result of larger geometrical nonuniformities.

Dark-field microscopy for characterization of single molecule dynamicsin vitroandin vivo

2019 ◽  
Vol 11 (21) ◽  
pp. 2778-2784
Author(s):  
Bingquan Wang ◽  
Dan Sun ◽  
Ce Zhang ◽  
Kaige Wang ◽  
Jintao Bai
Keyword(s):  
Single Molecule ◽  
Scattered Light ◽  
Dark Field ◽  
Fluorescent Labeling ◽  
Single Molecule Detection ◽  
Dark Field Microscopy

Dark-field microscopy directly detects scattered light from a sample, and therefore requires no fluorescent labeling for single molecule detection.

scholarly journals Characterization of Two Sets of Subpolar Flagella in Bradyrhizobium japonicum

2006 ◽  
Vol 189 (3) ◽  
pp. 1083-1089 ◽  
Author(s):  
Masaomi Kanbe ◽  
Jin Yagasaki ◽  
Susanne Zehner ◽  
Michael Göttfert ◽  
Shin-Ichi Aizawa
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Bradyrhizobium Japonicum ◽  
Soil Bacteria ◽  
Dark Field ◽  
Dark Field Microscopy ◽  
Soybean Roots ◽  
Flagellar Genes

ABSTRACT Bradyrhizobium japonicum is one of the soil bacteria that form nodules on soybean roots. The cell has two sets of flagellar systems, one thick flagellum and a few thin flagella, uniquely growing at subpolar positions. The thick flagellum appears to be semicoiled in morphology, and the thin flagella were in a tight-curly form as observed by dark-field microscopy. Flagellin genes were identified from the amino acid sequence of each flagellin. Flagellar genes for the thick flagellum are scattered into several clusters on the genome, while those genes for the thin flagellum are compactly organized in one cluster. Both types of flagella are powered by proton-driven motors. The swimming propulsion is supplied mainly by the thick flagellum. B. japonicum flagellar systems resemble the polar-lateral flagellar systems of Vibrio species but differ in several aspects.

scholarly journals X-ray Spectroscopic Characterization of Shock-Ignition-Relevant plasmas

10.14311/1771 ◽  
2013 ◽  
Vol 53 (2) ◽  
Author(s):  
Michal Šmíd ◽  
Luca Antonelli ◽  
Oldoich Renner
Keyword(s):  
Laser System ◽  
Plasma Temperature ◽  
Spectroscopic Characterization ◽  
Hot Electrons ◽  
X Ray ◽  
Monochromatic Imaging ◽  
Spatially Resolved ◽  
Ray Methods ◽  
Shock Ignition

Experiments with multilayer plastic/Cu targets performed at a PALS laser system aimed at the study of matter at conditions relevant to a shock ignition ICF scheme, and, in particular, at the investigation of hot electrons generation. Plasma temperature and density were obtained using high-resolution X-ray spectroscopy. 2D-spatially resolved quasi–monochromatic imaging was observing the hot electrons via fluorescence K emission in the copper tracer layer. Found values of plasma temperature 690 ± 10 eV, electron density 3 × 1022 cm-3 and the effective energy of hot electrons 45 ± 20 keV demonstrate the potential of X-ray methods in the characterization of the shock ignition environmental conditions.

Spectroscopic Characterization of Laser-Ablated Plume from a La—Ca—Mn—O Target in an O2 Ambient

1998 ◽  
Vol 52 (9) ◽  
pp. 1154-1159 ◽  
Author(s):  
Hai-Jun Dang ◽  
Ming-Fei Zhou ◽  
Qi-Zong Qin
Keyword(s):  
Slow Component ◽  
Optical Emission ◽  
Target Surface ◽  
Spectroscopic Characterization ◽  
Spectroscopic Technique ◽  
Observation Distance ◽  
Spatially Resolved ◽  
Optical Time ◽  
Time Of Flight Spectroscopy

The composition and evolution of the plume produced by the laser ablation of a La2O3–CaO–MnO2 target at 355 nm in an O2 ambient have been studied with a temporally and spatially resolved optical emission spectroscopic technique. Besides lines of excited metal atoms and ions, such as La(II), Ca(II), Mn(II), Ca(I), and Mn(I), bands of the metal oxides LaO and MnO were observed. In the oxygen ambient, two emission peaks corresponding to a fast and a slow component of ablated species Mn(I), MnO, Ca(I), and LaO were measured by optical time-of-flight spectroscopy. The delay times of two emission components for these ablated species were investigated as a function of the observation distance from the target surface and the laser fluence. The possible mechanism of the laser-ablated plume is discussed.

scholarly journals Synthesis, Characterization, and In Situ Antifungal and Cytotoxicity Evaluation of Ascorbic Acid-Capped Copper Nanoparticles

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Ernesto Beltrán-Partida ◽  
Benjamín Valdez-Salas ◽  
Ernesto Valdez-Salas ◽  
Guillermo Pérez-Cortéz ◽  
Nicola Nedev
Keyword(s):  
Ascorbic Acid ◽  
Copper Nanoparticles ◽  
Chemical Reduction ◽  
Dark Field ◽  
Industrial Applications ◽  
Dark Field Microscopy ◽  
Antifungal Potential ◽  
Massive Accumulation

The design route, synthesis, and characterization of spherical copper nanoparticles with antifungal potential are reported in the present work. Copper nanoparticles were synthesized by a novel, inexpensive, and eco-friendly chemical reduction method using ascorbic acid as a reductant and stabilizer under reflux conditions. The characterization results showed the formation of homogeneous, dispersed, and stable spherical ascorbic acid-capped copper nanoparticles (CuNPs) with a diameter of 250 nm. The CuNPs exhibited sustained antifungal activity againstCandida albicans(C. albicans) after 24 h and even 48 h of incubation. Using enhanced dark-field microscopy, we presented the in situ interaction between CuNPs andC. albicans. Here, part of the interaction of CuNPs among theC. albicans, studied without the use of any chemical and/or physical fixing method, is discussed. The results indicate that part of the antifungal mechanism involves a promoted adhesion of CuNPs onto the cell wall and a massive accumulation of CuNPs into the fungal cells, concluding in cellular leakage. The cytotoxicity (viability) evaluations indicated that our CuNPs were more biocompatible after comparison to the Cu precursor and triclosan (a commercial antifungal drug). The synthesized CuNPs will open up a new road for their possible use as a potent antimicrobial agent for clinical and industrial applications.

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