A5065753560- Atomic and Molecular Physics
- Ion-surface interactions and analysis
- Fullerene Chemistry and Applications
- Mass Spectrometry Techniques and Applications
- Diamond and Carbon-based Materials Research
- Advanced Chemical Physics Studies
- Electron and X-Ray Spectroscopy Techniques
- X-ray Spectroscopy and Fluorescence Analysis
- Nuclear Physics and Applications
- Polymer Nanocomposite Synthesis and Irradiation
- Superconducting and THz Device Technology
- Integrated Circuits and Semiconductor Failure Analysis
- Nuclear physics research studies
- Atmospheric Ozone and Climate
- Graphene research and applications
- Astrophysics and Star Formation Studies
- Laser-Matter Interactions and Applications
- Advanced biosensing and bioanalysis techniques
- Radiation Effects in Electronics
- Physics of Superconductivity and Magnetism
- Carbon Nanotubes in Composites
- Spectroscopy and Quantum Chemical Studies
- Particle Detector Development and Performance
- Advanced Semiconductor Detectors and Materials
- Photoreceptor and optogenetics research
Juntendo University Urayasu Hospital
2025
University of Tsukuba
2013-2024
Aarhus University
2001-2009
CEA Grenoble
1999-2003
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
1999-2003
Centre National de la Recherche Scientifique
2003
Centre de Recherche sur les Ions, les Matériaux et la Photonique
2003
NTT (Japan)
2002
A sensitive photoabsorption technique for studies of gas-phase biomolecules has been used at the ELISA electrostatic heavy-ion storage ring. We show that anion form chromophore green fluorescent protein in vacuo an absorption maximum 479 nm, which coincides with one two peaks protein. Its characteristics are therefore ascribed to intrinsic chemical properties chromophore. Evidently, special $\ensuremath{\beta}$-can structure provides shielding from surroundings without significantly changing...
An electrospray ion source has been coupled to an accelerator that injects ions into electrostatic heavy-ion storage ring. Since the dc current produced by ionization is low (∼106 ions/s), are accumulated in a cylindrical trap filled with helium buffer gas. The collisionally damped gas and confined central region rf field. Extraction from occurs within few microseconds after acceleration through 22 kV, of interest selected magnet according their mass charge ratio. bunch subsequently injected...
Background: This study was aimed at elucidating the mechanisms underlying development of treatment resistance in patients with acute myeloid leukemia (AML) other than M3 order to devise ways overcome and improve outcomes these patients. Methods: For this study, we randomly selected 35 AML who had received combined cytarabine plus idarubicin for new-onset our hospital. We performed immunohistochemical analysis biopsy specimens obtained from investigate expressions 23...
We have stored positively charged fullerene ions C(+)(n) (n even, from 48 to 70 and 76), C(2+)(60) C(2+)(70) in an electrostatic storage ring measured the rate of emission neutral fragments as a function time. In time range measurements, 50 micros few milliseconds, decreases strongly due radiative cooling molecules. Using predicted dielectric model, we extracted dissociation energies for C(2) loss measurements. As expected, are largest "magic" fullerenes, C(50), C(60), C(70), value 9.8+/-0.1...
Clusters of fullerenes (C60,C70)(n) are produced in a gas aggregation source and multiply ionized collisions with highly charged Xe(20+,30+) ions. Their stabilities decay processes analyzed high-resolution time-of-flight mass spectrometry. Fullerene clusters charge states up to q=5 have been observed appearance sizes found be as small n(app)=5, 10, 21, 33 for q=2, 3, 4, 5, respectively. The analysis the multicoincident fragmentation spectra indicates high mobility. This is contrast...
The lifetimes of both deprotonated adenosine ${5}^{\ensuremath{'}}$-monophosphate (AMP) and protonated AMP, after 266-nm photon absorption intramolecular vibrational redistribution, were determined to be $16\text{ }\ensuremath{\mu}\mathrm{s}$ based on a newly developed heavy-ion storage ring technique. Protonation the adenine nucleobase seriously affects fragmentation mechanism: major part photoexcited anions fragment in statistical (ergodic) process, whereas nearly all cations ($>99%$)...
We have studied energy transfer, fragmentation, and ionization in collisions between protons ${\mathrm{C}}_{60}$ molecules. The collision is varied 1 300 keV we thus cover a velocity range from 0.2 to 3.5 atomic units. distributions of intact fragmented ions been measured by means time-of-flight mass spectrometry using pulsed beams or emitted electrons clock the events. processes leading multiple evaporation neutral dimers are analyzed as functions projectile velocity. In contrast recent...
We present a static classical over-the-barrier model (OBM) for electron transfer between two isolated, infinitely conducting spheres with arbitrary and different electrical charges. This is shown to be very useful first estimates of single- multiple-electron cross sections in cluster-cluster collisions when the collision velocities are significantly lower than typical target velocities. For faster collisions, more advanced models such as dynamical OBM, or time-dependent local density...
We have observed the formation of ${\mathrm{C}}_{60}^{2\ensuremath{-}}$ and ${\mathrm{C}}_{\mathrm{70}}^{\mathrm{2}\mathrm{\ensuremath{-}}}$ in collisions between ${\mathrm{C}}_{\mathrm{60}}^{\mathrm{\ensuremath{-}}}/{\mathrm{C}}_{\mathrm{70}}^{\mathrm{\ensuremath{-}}}$ Na atoms. Cross sections for electron transfer to monoanion are determined be $36\ifmmode\pm\else\textpm\fi{}9$ $57\ifmmode\pm\else\textpm\fi{}14\text{ }{\AA{}}^{2}$ ${\mathrm{C}}_{60}^{\ensuremath{-}}$...
C60(2-) and C70(2-) dianions have been produced by electrospray of the monoanions subsequent electron pickup in a Na vapor cell. The were stored an electrostatic ring their decay emission was measured up to 1 s after injection. While ions are stable on this time scale, except for small fraction which excited gas collisions, most millisecond with lifetime depending strongly internal temperature. results can be modeled as tunneling through Coulomb barrier, mainly from thermally populated...
The authors find even-odd variations as functions of r (<or=7) for multiple ionization van der Waals dimers in slow Xe(30+)+[C60]2([C60C70])-->...+[C60]2(r+)([C60C70](r+)) electron-transfer collisions. This behavior is sharp contrast to the smooth one fullerene monomers and may be related effects dimer energies agreement with results from an electrostatic model. kinetic energy releases dissociations [predominantly yielding intact fullerenes [C60]2(r+)-->C60(r1+)+C60(r2+) same (r1=r2) or...
We have measured the time dependence of fragmentation protonated amino acids and peptides upon UV excitation in an electrostatic ion storage ring. After absorption a 266 nm photon, Trp (TrpH+) has lifetime 10–20 μs but also component with millisecond is present. The long may be due to fluorescence, which leads ions lower energy, or decay Trp+˙ radical cation formed after prompt hydrogen loss laser interaction region. Only one about 10 was detected for TyrH+. photoexcited PheH+ even shorter...
We report strong even-odd effects in multiple ionization yields of van der Waals dimers slow ${\mathrm{Xe}}^{30+}+[{\mathrm{C}}_{60}{]}_{2}([{\mathrm{C}}_{60}{\mathrm{C}}_{70}])\ensuremath{\rightarrow}\ensuremath{\cdots}+{[{\mathrm{C}}_{60}{]}_{2}}^{r+}({[{\mathrm{C}}_{60}{\mathrm{C}}_{70}]}^{r+})$ electron-transfer collisions as functions $r\ensuremath{\le}7$. This behavior may be due to variations the sequences dimer energies calculated with an electrostatic model including electrical...
We find that the most stable fullerene isomers, C70–C94, form efficiently in close-to central collisions between keV atomic ions and weakly bound clusters of more than 15 C60-molecules. observe extraordinarily high yields C70 marked preferences for C78 C84. Larger even-size carbon molecules, C96–C180, follow a smooth log-normal (statistical) intensity distribution. Measurements kinetic energies indicate C70–C94 mainly are formed by coalescence reactions small molecules C60, while Cn with...
We have measured the kinetic energy release for decay ${\mathrm{C}}_{60}^{q+}\ensuremath{\rightarrow}{\mathrm{C}}_{60\ensuremath{-}2m}^{(q\ensuremath{-}1)+}+{\mathrm{C}}_{2m}^{+}$ charge states $q=4--8$ and $m=1$ 2. The kinetic-energy increases linearly with fullerene state. estimates of barrier heights, deduced from releases, agree well observations regarding stability competition between separation $({\mathrm{C}}_{2}^{+}$ emission) neutral ${\mathrm{C}}_{2}$ emission highly charged fullerenes.
Recent experiments on biomolecules in accelerators and storage rings are reviewed. Topics included measurements of geometrical cross sections macromolecular ions, fragmentation peptide oligonucleotide ions after collisional electron transfer, lifetimes excited radiative cooling. Statistical versus non-statistical decay excitation collisions or by photon absorption is discussed.
We have measured the near-infrared absorption spectrum for isolated ${\mathrm{C}}_{60}^{\ensuremath{-}}$ ions at room temperature. Two bands, $9145\text{ }\text{ }{\mathrm{c}\mathrm{m}}^{\ensuremath{-}1}$ and $10460\text{ }{\mathrm{c}\mathrm{m}}^{\ensuremath{-}1}$, been identified in addition to main band $9382\text{ seen also low temperature a matrix. An interpretation based on theory of dynamic Jahn-Teller effects is proposed.
Abstract A double‐focusing mass spectrometer (MS) equipped with a superconducting‐tunnel‐junction (STJ) detector has been applied to measure relative ionization cross‐sections for the production of ions that are accompanied by different ion species same mass‐to‐charge ( m / z ) value. The STJ fabricated this study enables kinetic energy E measurement incoming individual at counting rate up ∼100 k ions/s and an resolution (Δ 15%. Both high high‐energy necessary independently determine both...
The stability of multiply charged sodium clusters Na(q+)(n) (q< or =10) produced in collisions between neutral and ions A(z+) ( z = 1 to 28) is experimentally investigated. Multiply are formed within a large range temperatures fissilities. They identified by means high-resolution reflectron-type time-of-flight mass spectrometer (m/deltam approximately 14 000). maximum fissility stable obtained for 28 X 0.85+/-0.07, slightly below the Rayleigh limit (X 1). It mainly limited initial cluster...
We have measured kinetic energy releases in asymmetric fission, ${\mathrm{C}}_{60}^{r+}\ensuremath{\rightarrow}{\mathrm{C}}_{58}^{(r\ensuremath{-}1)+}+{\mathrm{C}}_{2}^{+}$ $(r=6--9)$ and evaporation ${\mathrm{C}}_{60}^{r+}\ensuremath{\rightarrow}{\mathrm{C}}_{58}^{r+}+{\mathrm{C}}_{2}$ $(r=2,3),$ following multiple-electron removal from ${\mathrm{C}}_{60}$ ${\mathrm{He}}^{2+}$ ${\mathrm{Xe}}^{17+}$ collisions at $3q\mathrm{keV}(q=2,17).$ used the recoil-ion momentum technique limited...
Amino acid clusters have been studied by several groups and most notably magic number chiral recognition reported. In this work, we the formation of amino electrospray ionization (ESI) their stability high-energy collision-induced dissociation (CID). Appearance sizes were determined for multiply charged where charge is either due to protons or sodium ions. Finally, conclude that selectivity plays an important role in cluster but seems be minor importance fragmentation mixed clusters.