The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Jocelyne Fleuryfeith - One of the best experts on this subject based on the ideXlab platform.
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release of Metal Particles from needles used for transbronchial needle aspiration
Chest, 2011Co-Authors: V Gounant, Vincent Ninane, Xavier Janson, Magali Colombat, Marie Wislez, Dominique Grunenwald, Jean Francois Bernaudin, Jacques Cadranel, Jocelyne FleuryfeithAbstract:Background Although mediastinoscopy is still the gold standard for diagnosis of mediastinal lymphadenopathy, minimally invasive procedures have been developed: transbronchial needle aspiration (TBNA) using a flexible bronchoscope (conventional TBNA) or linear echoendoscope (endobronchial ultrasound [EBUS]) allowing real-time guided lymph node aspiration. The observation of contamination of samples by foreign Particles led us to determine the frequency and the nature of this material and to identify its origin. Methods From June 2007 to November 2008, 141 consecutive patients underwent conventional TBNA (n = 84) or EBUS-guided TBNA (EBUS-TBNA) (n = 57). All cytologic samples were reviewed in blinded fashion, and contamination was assessed semiquantitatively. Mineral analysis using a transmission electron microscope equipped with an energy dispersive x-ray spectrometer was performed on the solution obtained after rinsing unused needles and on four samples of calf thymuses punctured with EBUS needles. Results Foreign material, different from anthracosis, was identified in samples obtained with five different batches of needles, only from EBUS-TBNA (P Conclusions Dedicated EBUS-TBNA needles are able to release Metal Particles, probably by friction between the stylet and the needle, with a potential risk to inject Particles into nodes. The long-term consequences are unknown, but the need for safety measures should be evaluated.
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release of Metal Particles from needles used for transbronchial needle aspiration
Chest, 2011Co-Authors: V Gounant, Vincent Ninane, Xavier Janson, Magali Colombat, Marie Wislez, Dominique Grunenwald, Jean Francois Bernaudin, Jacques Cadranel, Jocelyne FleuryfeithAbstract:Background Although mediastinoscopy is still the gold standard for diagnosis of mediastinal lymphadenopathy, minimally invasive procedures have been developed: transbronchial needle aspiration (TBNA) using a flexible bronchoscope (conventional TBNA) or linear echoendoscope (endobronchial ultrasound [EBUS]) allowing real-time guided lymph node aspiration. The observation of contamination of samples by foreign Particles led us to determine the frequency and the nature of this material and to identify its origin. Methods From June 2007 to November 2008, 141 consecutive patients underwent conventional TBNA (n = 84) or EBUS-guided TBNA (EBUS-TBNA) (n = 57). All cytologic samples were reviewed in blinded fashion, and contamination was assessed semiquantitatively. Mineral analysis using a transmission electron microscope equipped with an energy dispersive x-ray spectrometer was performed on the solution obtained after rinsing unused needles and on four samples of calf thymuses punctured with EBUS needles. Results Foreign material, different from anthracosis, was identified in samples obtained with five different batches of needles, only from EBUS-TBNA ( P P = .035). Mineral analyses of the rinsing solutions from conventional TBNA needles were negative, whereas Metal alloys of iron, titanium, nickel, and chromium were released with EBUS needles. The same contamination was identified in three of the four punctured calf thymuses. Conclusions Dedicated EBUS-TBNA needles are able to release Metal Particles, probably by friction between the stylet and the needle, with a potential risk to inject Particles into nodes. The long-term consequences are unknown, but the need for safety measures should be evaluated.
Joseph R Lakowicz - One of the best experts on this subject based on the ideXlab platform.
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enhanced forster resonance energy transfer on single Metal particle 2 dependence on donor acceptor separation distance particle size and distance from Metal surface
Journal of Physical Chemistry C, 2007Co-Authors: Jian Zhang, Yi Fu, Mustafa H. Chowdhury, Joseph R LakowiczAbstract:We studied the effect of Metal Particles on Forster resonance energy transfer (FRET) between nearby donor−acceptor pairs. The studies included the effect of donor−acceptor distance, silver particle size, and distance from the Metal surface. The Metal Particles were synthesized with average diameters of 15, 40, and 80 nm, respectively. A Cy5-labeled oligonucleotide was chemically bound to a single silver particle with a distance of 2 or 10 nm from the surface of Metal core. A Cy5.5-labeled complementary oligonucleotide was bound to the particle-conjugated oligonucleotide by hybridization. The spacer length between donor−acceptor was adjusted by the number of base pairs. FRET between the donor−acceptor pair was investigated by dual-channel single-molecule fluorescence detection. Both the emission intensities and lifetimes indicated that FRET was enhanced efficiently by the Metal Particles. The results showed an increase of apparent energy transfer distance with the size of silver particle and distance from ...
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enhanced forster resonance energy transfer on single Metal particle 2 dependence on donor acceptor separation distance particle size and distance from Metal surface
Journal of Physical Chemistry C, 2007Co-Authors: Jian Zhang, Mustafa H. Chowdhury, Joseph R LakowiczAbstract:We studied the effect of Metal Particles on Forster resonance energy transfer (FRET) between nearby donor-acceptor pairs. The studies included the effect of donor-acceptor distance, silver particle size, and distance from the Metal surface. The Metal Particles were synthesized with average diameters of 15, 40, and 80 nm, respectively. A Cy5-labeled oligonucleotide was chemically bound to a single silver particle with a distance of 2 or 10 nm from the surface of Metal core. A Cy5.5-labeled complementary oligonucleotide was bound to the particle-conjugated oligonucleotide by hybridization. The spacer length between donor-acceptor was adjusted by the number of base pairs. FRET between the donor-acceptor pair was investigated by dual-channel single-molecule fluorescence detection. Both the emission intensities and lifetimes indicated that FRET was enhanced efficiently by the Metal Particles. The results showed an increase of apparent energy transfer distance with the size of silver particle and distance from the Metal core. Simulations by finite-difference time-domain (FDTD) calculations were used to compare with the experimental results. The local fields at the location of the donor-acceptor pair appeared to correlate with the FRET efficiency. These results will aid in the design of Metal Particles for using FRET to determine biomolecule proximity at distances beyond the usual Forster distance.
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Metal-enhanced single-molecule fluorescence on silver particle monomer and dimer: Coupling effect between Metal Particles
Nano Letters, 2007Co-Authors: Yi Fu, Mustafa H. Chowdhury, Joseph R LakowiczAbstract:We prepared silver particle dimers with single Cy5 molecules localized between coupled Metal Particles. The silver Particles with a 20 nm diameter were chemically bound with single-stranded oligonucleotides. The dimers were formed by hybridization with double-length single-stranded oligonucleotides that contained single Cy5 molecules. The image analysis revealed that the single-molecule fluorescence was enhanced 7-fold on the Metal monomer and 13-fold on the Metal dimer relative to the free Cy5-labeled oligonucleotide in the absence of Metal. The lifetimes were shortened on the silver monomers and further shortened on the silver dimers, demonstrating the near-field interaction mechanism of fluorophore with the Metal substrate. Finite-difference time-domain (FDTD) calculations were employed to study the distribution of electric field near the Metal monomer and dimer. The coupling effect of Metal particle on the fluorescence enhancement was discussed.
V Gounant - One of the best experts on this subject based on the ideXlab platform.
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release of Metal Particles from needles used for transbronchial needle aspiration
Chest, 2011Co-Authors: V Gounant, Vincent Ninane, Xavier Janson, Magali Colombat, Marie Wislez, Dominique Grunenwald, Jean Francois Bernaudin, Jacques Cadranel, Jocelyne FleuryfeithAbstract:Background Although mediastinoscopy is still the gold standard for diagnosis of mediastinal lymphadenopathy, minimally invasive procedures have been developed: transbronchial needle aspiration (TBNA) using a flexible bronchoscope (conventional TBNA) or linear echoendoscope (endobronchial ultrasound [EBUS]) allowing real-time guided lymph node aspiration. The observation of contamination of samples by foreign Particles led us to determine the frequency and the nature of this material and to identify its origin. Methods From June 2007 to November 2008, 141 consecutive patients underwent conventional TBNA (n = 84) or EBUS-guided TBNA (EBUS-TBNA) (n = 57). All cytologic samples were reviewed in blinded fashion, and contamination was assessed semiquantitatively. Mineral analysis using a transmission electron microscope equipped with an energy dispersive x-ray spectrometer was performed on the solution obtained after rinsing unused needles and on four samples of calf thymuses punctured with EBUS needles. Results Foreign material, different from anthracosis, was identified in samples obtained with five different batches of needles, only from EBUS-TBNA (P Conclusions Dedicated EBUS-TBNA needles are able to release Metal Particles, probably by friction between the stylet and the needle, with a potential risk to inject Particles into nodes. The long-term consequences are unknown, but the need for safety measures should be evaluated.
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release of Metal Particles from needles used for transbronchial needle aspiration
Chest, 2011Co-Authors: V Gounant, Vincent Ninane, Xavier Janson, Magali Colombat, Marie Wislez, Dominique Grunenwald, Jean Francois Bernaudin, Jacques Cadranel, Jocelyne FleuryfeithAbstract:Background Although mediastinoscopy is still the gold standard for diagnosis of mediastinal lymphadenopathy, minimally invasive procedures have been developed: transbronchial needle aspiration (TBNA) using a flexible bronchoscope (conventional TBNA) or linear echoendoscope (endobronchial ultrasound [EBUS]) allowing real-time guided lymph node aspiration. The observation of contamination of samples by foreign Particles led us to determine the frequency and the nature of this material and to identify its origin. Methods From June 2007 to November 2008, 141 consecutive patients underwent conventional TBNA (n = 84) or EBUS-guided TBNA (EBUS-TBNA) (n = 57). All cytologic samples were reviewed in blinded fashion, and contamination was assessed semiquantitatively. Mineral analysis using a transmission electron microscope equipped with an energy dispersive x-ray spectrometer was performed on the solution obtained after rinsing unused needles and on four samples of calf thymuses punctured with EBUS needles. Results Foreign material, different from anthracosis, was identified in samples obtained with five different batches of needles, only from EBUS-TBNA ( P P = .035). Mineral analyses of the rinsing solutions from conventional TBNA needles were negative, whereas Metal alloys of iron, titanium, nickel, and chromium were released with EBUS needles. The same contamination was identified in three of the four punctured calf thymuses. Conclusions Dedicated EBUS-TBNA needles are able to release Metal Particles, probably by friction between the stylet and the needle, with a potential risk to inject Particles into nodes. The long-term consequences are unknown, but the need for safety measures should be evaluated.
Paul Mulvaney - One of the best experts on this subject based on the ideXlab platform.
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surface plasmon spectroscopy of nanosized Metal Particles
Langmuir, 1996Co-Authors: Paul MulvaneyAbstract:The use of optical measurements to monitor electrochemical changes on the surface of nanosized Metal Particles is discussed within the Drude model. The absorption spectrum of a Metal sol in water is shown to be strongly affected by cathodic or anodic polarization, chemisorption, Metal adatom deposition, and alloying. Anion adsorption leads to strong damping of the free electron absorption. Cathodic polarization leads to anion desorption. Underpotential deposition (upd) of electropositive Metal layers results in dramatic blue-shifts of the surface plasmon band of the substrate. The deposition of just 0.1 monolayer can be readily detected by eye. In some cases alloying occurs spontaneously during upd. Alloy formation can be ascertained from the optical absorption spectrum in the case of gold deposition onto silver sols. The underpotential deposition of silver adatoms onto palladium leads to the formation of a homogeneous silver shell, but the mean free path is less than predicted, due to lattice strain in t...
Toshinobu Yoko - One of the best experts on this subject based on the ideXlab platform.
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effects of the incorporation of silver and gold nanoParticles on the photoanodic properties of rose bengal sensitized tio2 film electrodes prepared by sol gel method
Solar Energy Materials and Solar Cells, 1997Co-Authors: Gaoling Zhao, Hiromitsu Kozuka, Toshinobu YokoAbstract:Abstract Rose bengal-deposited TiO 2 film electrodes bearing dispersed Ag or Au nanoParticles were prepared by the sol-gel method. The dye-induced visible region photoresponse of the electrodes decreased with increasing Ag content up to a mole ratio of Ag/TiO 2 = 0.0207, while the UV photoresponse increased. On the other hand, the dye-induced visible region photoresponse decreased to a less extent by incorporation of a larger amount of Au Particles of Au/TiO 2 = 0.06, along with decreased UV photoresponse. The effects of the Metal Particles on the dye sensitization of the electrodes were discussed in terms of band edge fluctuation induced by the surface Metal Particles, Schottky barriers at TiO 2 /Metal interfaces, and surface plasma resonance.
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sol gel preparation and photoelectrochemical properties of tio2 films containing au and ag Metal Particles
Thin Solid Films, 1996Co-Authors: Gaoling Zhao, Hiromitsu Kozuka, Toshinobu YokoAbstract:Abstract TiO 2 film electrodes with a TiO 2 overlayer containing dispersed Au or Ag Metal Particles were prepared by the sol-gel method, and the effect of the Metal Particles on the photoelectrochemical properties of the TiO 2 electrodes were investigated. An increase in the anodic photocurrent in the visible region was observed for both the Au and Ag particle dispersed electrodes, which was thought to result from the surface plasma resonance of the Metal Particles. The introduction of Au Metal Particles, however, reduced the anodic photocurrent in the ultraviolet region, resulting in a decrease of the anodic photocurrent under the illumination of xenon lamp light. On the other hand, for the Ag particle dispersed electrodes, the anodic photocurrent in the ultraviolet region increased and then decreased with an increasing amount of Ag Particles. These effects of the dispersed Metal Particles on the photoelectrochemical properties of the TiO 2 electrodes were explained on the basis of the band models.