The reactivity of the reduction of NO pre-adsorbed on Rh clusters by CO was investigated using a combination of an alternate on-off gas injection method and thermal desorption spectrometry. The reduction of RhNO clusters by CO was evaluated by varying the CO concentration at = 903 K. Among the RhNO clusters, the RhNO cluster exhibited the highest reduction activity, whereas the other clusters, RhNO, showed lower reactivity.
View Article and Find Full Text PDFThe adsorption of hydrogen on gas-phase vanadium cluster cations, V ( = 3-14), at 300 K and desorption of hydrogen from hydride clusters, VH, upon heating were observed experimentally by combined thermal desorption spectrometry and mass spectrometry analyses. The ratio / was approximately 1.3 for all values at 300 K, which was reduced to approximately zero at 1000 K.
View Article and Find Full Text PDFStructures of platinum oxide cluster cations (PtO) were studied by ion mobility-mass spectrometry in combination with theoretical calculations. Structures of oxygen-equivalent PtO ( = 3-7) clusters were discussed from the comparison between their collision cross sections (CCSs) obtained by mobility measurement and simulated CCSs of their structural candidates from structural optimization calculations. Assigned structures of PtO were found to be composed of Pt frameworks and bridging O atoms, which follows the previous theoretical prediction on the neutral clusters.
View Article and Find Full Text PDFThe geometric structures of yttrium oxide cluster ions, YO ( = 3-11), were experimentally assigned for stable compositions by ion mobility mass spectrometry combined with theoretical calculations. The stable compositions were firstly determined by collision induced dissociation experiments in mass spectrometry as YO(YO) and YO(YO) for odd numbers of Y atoms ( = 2 + 1) and (YO) and O(YO) for even numbers of Y atoms ( = 2). The structures of the ions with the above compositions were assigned by comparing the collision cross sections obtained in the ion mobility measurement with those obtained by theoretical calculations.
View Article and Find Full Text PDFCerium oxide cluster cations were reacted with nitric oxide molecules and then measured by ion mobility mass spectrometry (IMMS). CeON species appeared as products of the reaction CeO + NO → CeON, and their collision cross sections (CCSs) with helium were obtained by IMMS. The experimental CCSs of CeON were 2-6 Å larger than those of CeO for = 4-10.
View Article and Find Full Text PDFPhys Chem Chem Phys
December 2021
Decomposition reactions of NO molecules on gas-phase Rh ( = 6-9) clusters were investigated by gas-phase thermal desorption spectrometry and density functional theory calculations. We found that NO adsorbs on the clusters, forming RhNO at room temperature. Upon heating, NO desorption was observed below 800 K.
View Article and Find Full Text PDFGeometric structures of free iridium cluster anions, Irn-, were examined by means of ion mobility mass spectrometry and density functional theory calculation for n = 3-15 with the additional help of photoelectron spectroscopy for n = 4-10. It has been revealed that Irn- clusters with n ≥ 5 favor a square facet and take a cubic motif in contrast to the face-centered cubic structures in the corresponding nanoparticles and bulk. A growth sequence of Irn- for n = 5-15 is proposed: single Ir atoms are sequentially attached to one side of the square plane of Ir4- to form a cubic Ir8-, and are then continuously attached on one of the square facets of Ir8- for n = 9-12 and Ir12- for n = 13-15.
View Article and Find Full Text PDFThermal dissociation of the cationic niobium-vanadium oxide clusters, NbVO (n + m = 2-8), was investigated by gas phase thermal desorption spectrometry. The oxygen-rich NbVO released O and O for odd and even values of n + m, respectively. Substitution of more than one Nb atom in NbO by V drastically lowered the desorption temperature of O for even values of n + m, whereas the substitution of more than two Nb atoms opened a new desorption path involving the release of O for odd values of n + m.
View Article and Find Full Text PDFThermal dissociation of cationic niobium oxide clusters (NbO) was investigated by gas phase thermal desorption spectrometry. The dominant species formed at 300 K were NbO (n = 2, 4, 6, ..
View Article and Find Full Text PDFInfrared multiple photon dissociation (IRMPD) spectra of RhO (m = 4-10) are obtained in the 300-1000 cm spectral range using the free electron laser for infrared experiments (FELIX) via dissociation of RhO or RhO-Ar complexes. The spectra are compared with the calculated spectra of several stable geometries obtained by density functional theory (DFT) structural optimization. The spectrum for RhO shows prominent bands at 620 and 690 cm and is assigned to a capped-square pyramidal Rh atom geometry with three bridging O atoms and one O atom in a hollow site.
View Article and Find Full Text PDFThe stability and reactivity of cationic gold-cerium oxide clusters, AuCeO (m ≤ 4, n ≤ 7, -1 ≤ x ≤ 2), were examined experimentally and computationally. These clusters were generated by simultaneous laser ablation of gold and cerium oxide targets and analyzed by time-of-flight mass spectrometry combined with gas-phase temperature-programmed desorption. Stable compositions of gold-cerium oxide clusters were identified as AuCeO and AuCeO for m ≥ 1, containing one oxygen atom more than the stable gold-free cerium oxide clusters CeO and CeO.
View Article and Find Full Text PDFThe reactivity of cerium oxide cluster cations, CenO2n+x(+) (n = 2-9, x = -1 to +2), with NO was investigated using gas-phase temperature-programmed desorption (TPD) combined with mass spectrometry. Target clusters were prepared in the gas phase via the laser ablation of a cerium oxide rod in the presence of oxygen, which was diluted using helium as a carrier gas. NO adsorbed onto stoichiometric and oxygen-rich clusters of CenO2n+x(+) (x = 0-2), forming CenO2n+x(NO)(+) (x = 0-2) species.
View Article and Find Full Text PDFOxygen deficient cerium oxide cluster ions, Ce(n)O(m)(+) (n = 2-10, m = 1-2n) were prepared in the gas phase by laser ablation of a cerium oxide rod. The reactivity of the cluster ions was investigated using mass spectrometry, finding that oxygen deficient clusters are able to extract oxygen atoms from CO, CO2, NO, N2O, and O2 in the gas phase. The oxygen transfer reaction is explained in terms of the energy balance between the bond dissociation energy of an oxygen containing molecule and the oxygen affinity of the oxygen-deficient cerium oxide clusters, which is supported by DFT calculations.
View Article and Find Full Text PDFCerium oxide cluster ions, Ce(n)O(2n+x)(+) (n = 2-9, x = -1 to +2), were prepared in the gas phase by laser ablation of a cerium oxide rod in the presence of oxygen diluted in He as the carrier gas. The stable stoichiometry of the cluster ions was investigated using a mass spectrometer in combination with a newly developed post heating device. The oxygen-rich clusters, Ce(n)O(2n+x)(+) (x = 1, 2), were found to release oxygen molecules, and Ce(n)O(2n+x)(+) (x = -1, 0) were exclusively formed by post heating treatment at 573 K.
View Article and Find Full Text PDFText messaging may be excessive and young people may be dependent on it. We distributed the Self-perception of Text-message Dependency Scale (STDS), Hospital Anxiety and Depression Scale (HADS), Temperament and Character Inventory (TCI), and Relationship Questionnaire (RQ) to 223 Japanese university students in a two-wave study, separated by a 5-month interval. The STDS yielded a three-factor structure.
View Article and Find Full Text PDFPsychiatry Clin Neurosci
February 2014
Aim: The coping style that individuals think they will use when encountering stressful situations may differ from actual coping response in real situations.
Methods: In a longitudinal study on some 500 university students, perceived coping style was identified using the Coping Inventory for Stressful Situations on the first occasion. In the subsequent eight test occasions, which occurred on a weekly basis, the students were asked about a negative life event that occurred during the past week and the actual coping responses they used.
This study focused on the functional aspects of narcissism in regulating self-conscious emotions (guilt, shame, hubristic pride, and achievement-oriented pride) as well as two other attribution styles (externalization and detachment). The authors investigated Japanese university students (N = 452) with regard to their self-conscious emotions using the Test of Self-Conscious Affect-3 (TOSCA-3) and their narcissistic personality using the short version of Narcissistic Personality Inventory (NPI-S). Structural equation modeling was used for the analysis.
View Article and Find Full Text PDFObjective. To examine the effects of temperament and character profiles on state and trait depression and anxiety in a Japanese youth population. Method.
View Article and Find Full Text PDFThis study used a structural equation model to examine the influence of resilience on the four self-conscious affects (guilt-proneness, shame-proneness, externalization, and detachment) assessed in the Test of Self-Conscious Affect-3 (TOSCA-3) and their impact on depressive mood. Our subject population consisted of 447 Japanese university students. The first analysis explored which TOSCA-3 affects help an individual adapt to stressful situations.
View Article and Find Full Text PDFTo simultaneously examine the impact of childhood abuse history on borderline personality traits, negative life events, and depression, undergraduate students (N=243) were studied by questionnaire surveys with one week intervals. Neglect and emotional abuse as well as sexual maltreatment predicted borderline personality traits and baseline depression. Baseline depression as well as the impact of negative life events occurring the week prior predicted depression a week later.
View Article and Find Full Text PDFTo investigate the relationship among adult attachment style, life stress, and daily depression, a sample of 437 undergraduate students was prospectively studied. Insecure adult attachment and perceived life stress were related to their daily depressive mood. Further analyses using both multiple hierarchical regression and structural equation models (SEM) demonstrated that adult attachment style and perceived life stress independently predicted depression and had no interactive effects on daily depression.
View Article and Find Full Text PDFAfter examining the definitions of persecutory and penitential types of guilt, based on Melanie Klein's view, we developed a single-item measure of these types and examined reliability and validity of the measure in three studies. Concurrent validity of the measure was shown among a university student population using the Test of Self-Conscious Affect-3 as an external validator. The questionnaire was not influenced by a socially desirable response style.
View Article and Find Full Text PDFUrocortin, a recently identified member of the corticotropin-releasing factor (CRF) family, is implicated in the central control of appetite and energy metabolism. We previously reported that peripherally administered urocortin inhibits gastric emptying in conscious mice. In this study, we investigated the effect of intracerebroventricularly administered urocortin on gastric emptying, food intake and body weight in mice.
View Article and Find Full Text PDFThe manzamine alkaloids such as manzamine A, B, and C belongs to a unique family of cyctotoxic beta-carbline linked azacycles, which have been isolated from several marine sponges. Manzamine A has recently been shown to exhibit in vivo antimalarial activity against parasite Plasmodium berghei. Further progress was added recently by the isolation of the new and closely related members such as nakadomarin A, as well as an ingenious proposal for their biosynthetic pathway.
View Article and Find Full Text PDF