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ABSTRACT: Interference effects on electron momentum profiles have been studied using binary (e, 2e) spectroscopy for the three outermost molecular orbitals of CF(4), which are composed of the F 2p nonbonding atomic orbitals. An analysis of the measured spherically averaged electron momentum densities has clearly shown the presence of oscillatory structures having direct information about the internuclear distance between the F atoms. Furthermore, it is demonstrated that the phase of the oscillatory structures depends upon the orientation in space of the constituent atomic orbitals.
Physical Review Letters 04/2012; 108(17):173201. · 7.37 Impact Factor
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ABSTRACT: We report a theoretical study of vibronic effects on the 1t(1) → 3s Rydberg excitation in CF(4) induced by electron impact. The generalized oscillator strength for the excitation has been calculated using theoretical wave functions at the equation-of-motion coupled cluster singles and doubles level. In the calculation vibronic effects have been taken into account by evaluating the electronic transition moment along the individual normal coordinates. The present calculation successfully reproduces our recent experimental result [N. Watanabe, D. Suzuki, and M. Takahashi, J. Chem. Phys. 134, 064307 (2011)] over the full momentum transfer region studied. By examining contributions from individual normal modes, the asymmetric stretching mode is found to play a leading role in the 1t(1) → 3s transition at small momentum transfer.
The Journal of chemical physics 06/2011; 134(23):234309. · 3.09 Impact Factor
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ABSTRACT: We report an angle-resolved electron energy loss spectroscopy (EELS) study on the valence-shell electronic excitations in CF(4). Experimentally momentum-transfer-dependent generalized oscillator strengths (GOSs) or GOS profiles for low-lying electronic excitations at 12.6, 13.8, and 14.8 eV are derived from EELS spectra measured at an incident electron energy of 3 keV. We also calculate GOS profiles using theoretical wave functions at the equation-of-motion coupled cluster singles and doubles level. There are good agreements between experiment and theory except for a significant discrepancy at small momentum transfer for the 1t(l) → 3s Rydberg excitation at 12.6 eV. The experimental GOS profile for 1t(l) → 3s exhibits a shape that is typical of a dipole allowed transition, while the excitation is formally dipole forbidden. This symmetry breaking behavior is rationally accounted for by qualitatively analyzing the nature of vibronic coupling effects. For the excitation band at 13.8 eV, a shoulder and extrema are observed in the GOS profile and are then found to be mainly due to the 2(1)T(2) transition. Furthermore, the theoretical GOS profile for the 2(1)T(2) transition exhibits a remarkable oscillatory pattern; its origin is discussed by considering multicenter interference effects. For the 14.8 eV excitation band, the predominant nondipole nature of the underlying transitions are revealed and comparisons with the theoretical calculations show that major contributions to this band come from the 4t(2) → 3p excitation.
The Journal of chemical physics 02/2011; 134(6):064307. · 3.09 Impact Factor
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ABSTRACT: Momentum profiles have been measured for the two outermost atomic orbitals of noble gases, Ar, Kr and Xe, at incident electron energy of about 2 keV using a newly developed multichannel (e,2e) spectrometer. The experimental results exhibit significantly improved statistics compared with those achieved in previous studies while covering a wide range of momenta up to 3.6 a.u. The results are compared with theoretical calculations using four (e,2e) scattering models, the plane-wave impulse and Born approximations (PWIA and PWBA), and the distorted-wave impulse and Born approximations (DWIA and DWBA). The DWIA and DWBA scattering models have been found to satisfactorily reproduce the experimental momentum profiles in terms of both shape and intensity over the entire momentum range covered, indicating the importance of distorted wave effects for quantitatively describing (e,2e) reaction.
Physical Chemistry Chemical Physics 08/2006; 8(25):3022-8. · 3.57 Impact Factor
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ABSTRACT: We present two cases showing significantly prolonged action of vecuronium from magnesium treatment after general anesthesia for urgent cesarean section. The serum magnesium levels were maintained at a therapeutic range for severe eclampsia in one patient (5.6 mg.dl(-1)) and for tocolysis in another with placenta previa totalis (6.9 mg.dl(-1)). The obstetrics-specific emergency in each patient led us to proceed with general anesthesia but using reduced-dose vecuronium, which failed to prevent prolongation of the neuromuscular block. As a result, the patients received prolonged mechanical ventilation. Our cases underscore the need for anesthesiologists as well as obstetricians to be aware of the prolongation of the action of nondepolarizing muscle relaxants as a result of magnesium treatment.
Journal of Anesthesia 02/2006; 20(1):33-5. · 0.83 Impact Factor
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ABSTRACT: Electron momentum spectroscopy is applied to study the two outermost orbitals of glyoxal and biacetyl. From the experimental
momentum profiles, it has been unambiguously concluded that through-bond interaction dominates in these molecules. The results
are compared with associated theoretical profiles, illuminating the importance of electron correlation effects for quantitative
predictions of electron densities of the orbitals.
01/2006: pages 265-278;
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ABSTRACT: Morphine has been an optimal choice for cancer pain management. However, several recent studies suggested that morphine induces apoptosis in human peripheral blood lymphocytes (PBLs), raising a serious concern about the use of opioid-based analgesic strategies. In this study, therefore, we aimed to evaluate whether morphine induced apoptosis in cultured human PBLs. Apoptotic events were assessed by flow-cytometrical detection of surface phosphatidylserine and nuclear fragmentation, as well as Fas, Bcl-2, and Caspase-3 activity in PBLs gated on a light-scatter basis. Peripheral blood mononuclear cells isolated from healthy subjects were cultured with etoposide, morphine, or vehicle (medium) for 48 h. During co-culture with etoposide, apo-ptosis was significantly induced in PBLs, and the cells did not survive for 48 h. In comparison, morphine had no effect on the expression rate of any of the detected molecules, suggesting that no apparent apoptotic processes were induced during the incubation. Furthermore, co-incubation with a Fas-specific antibody did not increase apoptotic cell rates in the morphine cultures. These results do not support the hypothesis that morphine directly modulates PBL apoptosis resulting in immunosuppression. We believe that the choice of opioids for optimal pain relief should not be discouraged until further studies clarify this issue. IMPLICATIONS: Recent reports that morphine potentially induces apoptosis in human lymphocytes in vitro have raised a concern about the use of opioid-based analgesic strategies. Regarding this issue, we present rather contradictory findings that morphine has no effects on the cell expression of various apoptosis-related molecules in cultured human lymphocytes.
Anesthesia & Analgesia 11/2005; 101(4):1117-22, table of contents. · 3.29 Impact Factor
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ABSTRACT: Theoretical fine spectroscopy has been performed for the valence ionization spectra of furan, pyrrole, and thiophene with the symmetry-adapted-cluster configuration-interaction general-R method. The present method described that the pi(1) state interacts with the pi(3) (-2)pi*, pi(2) (-2)pi*, and pi(2) (-1)pi(3) (-1)pi* shake-up states providing the split peaks and the outer-valence satellites, both of which are in agreement with the experiments. The intensity distributions were analyzed in detail for the inner-valence region. In particular, for furan, theoretical intensities were successfully compared with the intensity measured by the electron momentum spectroscopy. The interactions of the 3b(2) and 5a(1) states with the shake-up states were remarkable for furan and pyrrole, while the 4b(2) state of thiophene had relatively large intensity.
The Journal of Chemical Physics 07/2005; 122(23):234319. · 3.33 Impact Factor
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ABSTRACT: The transintervertebral disc approach was proposed recently for percutaneous neurolytic celiac plexus block (NCPB). Its superior simplicity, reliability, as well as safety potentially overcome the technical hurdles of NCPB that may interfere with the practical use of this validated analgesic intervention for abdominal cancer pain. The present study was conducted to evaluate the effectiveness of the use of this approach in a resident education program for NCPB.
The clinical results of NCPBs conducted from January 2001 to September 2002 were examined comparing that performed by institutional residents with that by specialized physicians authorized by the Japanese Society of Pain Clinicians. The transintervertebral disc approach was used in all cases. Each resident completed NCPB under close supervision of the specialists.
Twenty-four patients received NCPB during the study period. Seven residents randomly completed 12 procedures and 4 specialists did others. The duration of fluoroscopy to complete the procedure was 256+/-109 sec in the resident group and 392+/-194 sec in the specialist group (ns). Significant pain reduction was obtained immediately after NCPB in all patients without any intergroup difference. No critical complication was observed in each group.
The transintervertebral disc approach can be used effectively and safely in educational practice of NCPB for less-trained physicians.
Masui. The Japanese journal of anesthesiology 08/2004; 53(7):820-4.
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ABSTRACT: We developed a flowchart for the treatment of cancer-related hypercalcemia based on the review of previous reports. The treatment protocols were standardized in each group of four different ranges of serum calcium concentration (< 12, 12-14, 14-16, < 16 mg/dl). In each Ca range, specific treatment was adjusted according to the clinical evaluation of symptoms and progression of illness of the patients.
Gan to kagaku ryoho. Cancer & chemotherapy 01/2004; 30(13):2145-53.
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ABSTRACT: To provide additional pharmacokinetic evidence for the oral-to-parenteral relative potency ratio of 1:2 to 1:3 for chronic morphine use in a palliative care setting, we determined the plasma concentrations of morphine and its major metabolites, morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G), in hospitalized advanced cancer patients maintained on long-term oral or intravenous morphine. There were significant linear correlations between daily doses of morphine and plasma concentrations (molar base) of morphine, M3G and M6G for both routes of administration. The oral-to-intravenous relative ratios of the regression coefficients were 2.9 for morphine and 1.8 for morphine + M6G. The morphine kinetic variables were not significantly influenced by any hepato-renal biochemical markers. These results support the commonly used oral-to-intravenous relative potency ratio of 1:2 to 1:3 in patients with cancer pain receiving chronic morphine treatment.
Palliative Medicine 01/2004; 17(8):673-8. · 2.38 Impact Factor
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ABSTRACT: Patients with intractable cancer pain often require non-pharmacological analgesic treatment that is accompanied by procedure-related pain. Previous works have shown that propofol infusion in adjunction to regional anesthesia provides appropriate sedation during such painful procedures. However, there are a few reports of its use to reduce procedure-related pain in terminal cancer patients. We report cases of propofol sedation during percutaneous vertebroplasty (PVP) in patients with metastatic vertebral compression fracture.
Propofol was infused during PVP in eleven cancer patients after obtaining written informed consent. The infusion rate of propofol was adjusted using a target-controlled infusion pump to achieve appropriate sedation levels under monitoring bispectral index of the electroencepharogram. Hepatic and renal functions were evaluated using common serum markers, which were determined using standard hospital laboratory methods.
The duration of the procedure was 65.5 +/- 5.5 (mean +/- SD) min. The required infusion rate was 8.66 +/- 1.50 mg.kg-1.hr-1. The interval from the termination of the infusion until emergence was 10.7 +/- 4.2 min. No life-threatening complications or significant changes in liver and renal functions were observed.
Propofol can be used effectively and safely for sedation during PVP in terminal cancer patients.
Masui. The Japanese journal of anesthesiology 08/2003; 52(7):740-3.
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Journal of Anesthesia 02/2003; 17(3):196-8. · 0.83 Impact Factor
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ABSTRACT: Accurate estimation of survival is important for effective palliative medicine of patients with cancer. In most clinical practice, however, the life expectancy has been predicted based on subjective evaluations. The purpose of this study was to find objective biological markers that can contribute to accurate prediction of survival in terminally ill cancer patients. Consecutive terminally ill cancer patients admitted to the Palliative Care Center in Tohoku University hospital from January to May 2001 were approached for this study. Forty-eight blood samples were obtained from 25 patients who provided a written informed consent. Common serum enzyme markers were determined using standard hospital laboratory methods. Cellular immunity status was evaluated by peripheral blood lymphocyte-subset analysis using flow cytometry. Mean patient survival was 33.5 +/- 21.6 (1-80) days. Multiple regression analysis revealed that lactate dehydrogenase (LDH) and the CD4+/CD8+ ratio were significantly associated with survival (r = 0.64, p < 0.0001). Further prospective studies are warranted to validate the usefulness of these determinants for accurate prediction of survival.
Gan to kagaku ryoho. Cancer & chemotherapy 10/2002; 29(10):1779-83.
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ABSTRACT: Experimental momentum profiles of the lone pair orbitals of several thiols and dimethyl sulfide have been measured and compared with theoretical momentum profiles. All the observed profiles exhibit p-type character, confirming that the orbitals have been characterized as sulfur nonbonding orbitals. However, small shifts in the profiles are found, depending on substituents. The results are discussed in relation to the geometries of the molecules.
01/1997;
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ABSTRACT: Electron momentum spectroscopy is applied to study the two outermost orbitals of 1,4-diazabicyclo[2.2.2]octane. From the experimental momentum profiles, it has been unambiguously concluded that through-bond interaction dominates in this molecule and that the highest occupied molecular orbital is totally symmetric while the next highest occupied molecular orbital is anti-symmetric. The importance of diffuse functions in elucidating the electronic structure of molecules is confirmed.
Chemical Physics Letters 308:195-198. · 2.34 Impact Factor
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ABSTRACT: The furan (C4H4O) molecule has been studied using electron momentum spectroscopy at an impact energy of 800 eV. Binding energy spectra ranging up to 31 eV have been measured at target electron momenta from about 0.1 to 3.6 au. Electron momentum profiles of individual orbitals are obtained by deconvolution from a series of the spectra measured at selected electron momenta. The experimental momentum profiles are compared with theoretical ones calculated using the 6-31++G** basis set. Band assignments and the electron correlation effects are investigated through the orbital-specific momentum profiles. The results are compared with Green's function calculations by G. Bieri, L. Åsbrink, and W. von Niessen (J. Electron Spectrosc. Relat. Phenom. 27 (1982) 129) in terms of the ionization energies and their corresponding pole strengths.
Chemical Physics. 227(3):375-387.
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ABSTRACT: Electron momentum spectroscopy is applied to determine the character of the two outermost π orbitals of norbornadiene and 1,4-cyclohexadiene. From comparisons of observed and calculated electron momentum distributions, the highest occupied molecular orbital is experimentally identified as π− in the former and as π+ in the latter.
Chemical Physics Letters 288:714-718. · 2.34 Impact Factor
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ABSTRACT: The electronic structure of the pyrrole (C4H5N) molecule has been studied using electron momentum spectroscopy at an impact energy of 800 eV plus binding energy. Binding energy spectra have been measured at selected electron momenta. An attempt to clarify the band assignments, which have been in controversy, is made with the aid of theoretical electron momentum profiles calculated using the 6-31++G** basis set. A set of assignments which reproduces the observations is proposed, and it is concluded that electron correlation effects are significant in the innermost π electron ionization.
Chemical Physics Letters 288:821-827. · 2.34 Impact Factor
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ABSTRACT: Electron momentum spectroscopy (EMS) makes it possible to examine orbital patterns of individual molecular orbitals in momentum space. A new spectrometer for electron–electron coincidence experiments for EMS has been developed to obtain orbital patterns quantitatively. Using a spherical analyzer and position-sensitive two-dimensional detectors combined with fast electronics, simultaneous measurements of energy and angular correlations between the two outgoing electrons can be made. This spectrometer features high sensitivity and an ease of changing impact energies. Details of the apparatus are described and impact energy dependence of electron momentum distributions of the HOMO of H2 and biacetyl are compared.
Journal of Electron Spectroscopy and Related Phenomena.
