The Experts below are selected from a list of 107874 Experts worldwide ranked by ideXlab platform
Koichi Ohno - One of the best experts on this subject based on the ideXlab platform.
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collision energy resolved penning ionization electron spectroscopy of phenylacetylene and diphenylacetylene by collision with he 23s metastable atoms
Journal of Physical Chemistry A, 2006Co-Authors: Andriy Borodin, Masakazu Yamazaki, Naoki Kishimoto, Koichi OhnoAbstract:Penning ionization of phenylacetylene and diphenylacetylene upon collision with metastable He*(23S) atoms was studied by collision-energy-/electron-energy-resolved two-dimensional Penning ionization electron spectroscopy (2D-PIES). On the basis of the collision energy dependence of partial ionization cross-sections (CEDPICS) obtained from 2D-PIES as well as ab initio molecular orbital calculations for the approach of a metastable atom to the Target Molecule, anisotropy of interaction between the Target Molecule and He*(23S) was investigated. For the calculations of interaction potential, a Li(22S) atom was used in place of He*(23S) metastable atom because of its well-known interaction behavior with various Targets. The results indicate that attractive potentials localize in the π regions of the phenyl groups as well as in the π-conjugated regions of the acetylene group. Although similar attractive interactions were also found by the observation of CEDPICS for ionization of all π MOs localized at the C⋮C b...
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collision energy resolved penning ionization electron spectroscopy of hcooh ch3cooh and hcooch3 by collision with he 23s metastable atoms
Journal of Physical Chemistry A, 2005Co-Authors: Andriy Borodin, Masakazu Yamazaki, Naoki Kishimoto, Koichi OhnoAbstract:Penning ionization of formic acid (HCOOH), acetic acid (CH3COOH), and methyl formate (HCOOCH3) upon collision with metastable He*(23S) atoms was studied by collision-energy/electron-energy-resolved two-dimensional Penning ionization electron spectroscopy (2D-PIES). Anisotropy of interaction between the Target Molecule and He*(23S) was investigated based on the collision energy dependence of partial ionization cross sections (CEDPICS) obtained from 2D-PIES as well as ab initio molecular orbital calculations for the access of a metastable atom to the Target Molecule. For the interaction potential calculations, a Li atom was used in place of He*(23S) metastable atom because of its well-known similarity in interaction with Targets. The results indicate that in the studied collision energy range the attractive potential localizes around the oxygen atoms and that the potential well at the carbonyl oxygen atom is at least twice as much as that at the hydroxyl oxygen. Moreover we can notice that attractive potent...
Andriy Borodin - One of the best experts on this subject based on the ideXlab platform.
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collision energy resolved penning ionization electron spectroscopy of phenylacetylene and diphenylacetylene by collision with he 23s metastable atoms
Journal of Physical Chemistry A, 2006Co-Authors: Andriy Borodin, Masakazu Yamazaki, Naoki Kishimoto, Koichi OhnoAbstract:Penning ionization of phenylacetylene and diphenylacetylene upon collision with metastable He*(23S) atoms was studied by collision-energy-/electron-energy-resolved two-dimensional Penning ionization electron spectroscopy (2D-PIES). On the basis of the collision energy dependence of partial ionization cross-sections (CEDPICS) obtained from 2D-PIES as well as ab initio molecular orbital calculations for the approach of a metastable atom to the Target Molecule, anisotropy of interaction between the Target Molecule and He*(23S) was investigated. For the calculations of interaction potential, a Li(22S) atom was used in place of He*(23S) metastable atom because of its well-known interaction behavior with various Targets. The results indicate that attractive potentials localize in the π regions of the phenyl groups as well as in the π-conjugated regions of the acetylene group. Although similar attractive interactions were also found by the observation of CEDPICS for ionization of all π MOs localized at the C⋮C b...
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collision energy resolved penning ionization electron spectroscopy of hcooh ch3cooh and hcooch3 by collision with he 23s metastable atoms
Journal of Physical Chemistry A, 2005Co-Authors: Andriy Borodin, Masakazu Yamazaki, Naoki Kishimoto, Koichi OhnoAbstract:Penning ionization of formic acid (HCOOH), acetic acid (CH3COOH), and methyl formate (HCOOCH3) upon collision with metastable He*(23S) atoms was studied by collision-energy/electron-energy-resolved two-dimensional Penning ionization electron spectroscopy (2D-PIES). Anisotropy of interaction between the Target Molecule and He*(23S) was investigated based on the collision energy dependence of partial ionization cross sections (CEDPICS) obtained from 2D-PIES as well as ab initio molecular orbital calculations for the access of a metastable atom to the Target Molecule. For the interaction potential calculations, a Li atom was used in place of He*(23S) metastable atom because of its well-known similarity in interaction with Targets. The results indicate that in the studied collision energy range the attractive potential localizes around the oxygen atoms and that the potential well at the carbonyl oxygen atom is at least twice as much as that at the hydroxyl oxygen. Moreover we can notice that attractive potent...
Akifumi Kawamura - One of the best experts on this subject based on the ideXlab platform.
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Design of nano- and micro-structured Molecule-responsive hydrogels
Polymer Journal, 2017Co-Authors: Akifumi KawamuraAbstract:Our recent studies on the nano- and micro-structured Molecule-responsive hydrogels are summarized. The nano- and micro-structured Molecule-responsive hydrogels exhibited rapid swelling/shrinkage behavior in response to a Target Molecule based on the association/dissociation of molecular complexes that act as crosslinkers. In addition, these hydrogels showed smart functions, such as autonomous Molecule-responsive microchannel flow regulation and highly sensitive detection of a Target Molecule. The smart functions of nano- and micro-structured Molecule-responsive hydrogels can provide tools for constructing sensors, microdevices and smart biomaterials. Stimuli-responsive hydrogels have attracted considerable attention for use as smart materials, such as in molecular sensors and drug delivery systems. With a focus on their crosslinking density, we have prepared various Molecule-responsive hydrogels that undergo volume changes in response to Target Molecules based on the association/dissociation of molecular complexes that act as crosslinkers. Recent developments in polymerization techniques enabled us to design various types of polymer nanomaterials. This focus review provides a short overview of our recent studies on the nano- and micro-structured Molecule-responsive hydrogels prepared using various polymerization techniques, such as photopolymerization, surface-initiated atom transfer radical polymerization and soap-free emulsion polymerization. The nano- and micro-structured Molecule-responsive hydrogels showed not only rapid swelling/shrinkage in response to a Target Molecule owing to their large surface area but also smart functions, such as autonomous Molecule-responsive microchannel flow regulation and highly sensitive detection of a Target Molecule. The smart functions of nano- and micro-structured Molecule-responsive hydrogels can provide tools for constructing, for example, sensors, microdevices and smart biomaterials.
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Target Molecule-responsive hydrogels designed via molecular imprinting using bisphenol A as a template
Chemical Communications, 2014Co-Authors: Akifumi Kawamura, Tadahiro Kiguchi, Takeshi Nishihata, Tadashi Uragami, Takashi MiyataAbstract:Target Molecule-responsive hydrogels with β-cyclodextrin (β-CD) were prepared via molecular imprinting using bisphenol A (BPA) as a template. BPA-imprinted hydrogels showed greater shrinkage than non-imprinted hydrogels because CD ligands arranged at suitable positions formed CD–BPA–CD complexes that acted as crosslinks.
Jean Aubard - One of the best experts on this subject based on the ideXlab platform.
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A scheme for detecting every single Target Molecule with surface-enhanced Raman spectroscopy.
Nano letters, 2011Co-Authors: Johan Grand, Idrissa Sow, Walter R. C. Somerville, Pablo G. Etchegoin, Mona Tréguer-delapierre, Gaëlle Charron, Nordin Félidj, Georges Lévi, Jean AubardAbstract:Surface-enhanced Raman spectroscopy (SERS) is now a well-established technique for the detection, under appropriate conditions, of single Molecules (SM) adsorbed on metallic nanostructures. However, because of the large variations of the SERS enhancement factor on the surface, only Molecules located at the positions of highest enhancement, so-called hot-spots, can be detected at the single-Molecule level. As a result, in all SM-SERS studies so far only a small fraction, typically less than 1%, of Molecules are actually observed. This complicates the analysis of such experiments and means that trace detection via SERS can in principle still be vastly improved. Here we propose a simple scheme, based on selective adsorption of the Target analyte at the SERS hot-spots only, that allows in principle detection of every single Target Molecule in solution. We moreover provide a general experimental methodology, based on the comparison between average and maximum (single Molecule) SERS enhancement factors, to veri...
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A scheme for detecting every single Target Molecule with surface-enhanced Raman spectroscopy.
Nano Letters, 2011Co-Authors: Johan Grand, Idrissa Sow, Walter R. C. Somerville, Pablo G. Etchegoin, Mona Tréguer-delapierre, Gaëlle Charron, Nordin Félidj, Georges Lévi, Jean AubardAbstract:Surface-enhanced Raman spectroscopy (SERS) is now a well-established technique for the detection, under appropriate conditions, of single Molecules (SM) adsorbed on metallic nanostructures. However, because of the large variations of the SERS enhancement factor on the surface, only Molecules located at the positions of highest enhancement, so-called hot-spots, can be detected at the single-Molecule level. As a result, in all SM-SERS studies so far only a small fraction, typically less than 1%, of Molecules are actually observed. This complicates the analysis of such experiments and means that trace detection via SERS can in principle still be vastly improved. Here we propose a simple scheme, based on selective adsorption of the Target analyte at the SERS hot-spots only, that allows in principle detection of every single Target Molecule in solution. We moreover provide a general experimental methodology, based on the comparison between average and maximum (single Molecule) SERS enhancement factors, to verify the efficiency of our approach. The concepts and tools introduced in this work can readily be applied to other SERS systems aiming for detection of every single Target Molecule.
Oliver Inhoff - One of the best experts on this subject based on the ideXlab platform.
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parasite specific trypanothione reductase as a drug Target Molecule
Parasitology Research, 2003Co-Authors: Luise R Krauthsiegel, Oliver InhoffAbstract:Trypanosomatids are the causative agents of African sleeping sickness, Chagas' disease, and the different manifestations of leishmaniasis. New drugs against these parasitic protozoa are urgently needed since the current drugs are unsatisfactory, in particular due to serious adverse side effects. In trypanosomes and leishmanias, the nearly ubiquitous glutathione/glutathione reductase system is replaced by trypanothione and trypanothione reductase. The essential role of trypanothione reductase in the parasite thiol metabolism and its absence from the mammalian host render the enzyme a highly attractive Target Molecule for a structure-based drug development against trypanosomatids. This article provides an overview on the known classes of trypanothione reductase inhibitors and their in vitro activity against parasitic protozoa. The (dis)advantages of the different types of compounds as potential drug candidates as well as modern computer-based approaches to the identification of new leads are discussed.
