Risk factors for thrombocytopenia and analysis of time to platelet transfusion after azacitidine treatment

The use of azacitidine (AZA) has been known to lead to a high incidence of hematotoxic adverse events. The aims of this study were to identify the risk factors for thrombocytopenia after the administration of AZA and to analyze time to the initial platelet transfusion. Sixty-two patients with myelodysplastic syndrome (MDS), who were treated with AZA in Gifu Municipal Hospital between March 2012 and June 2020, were included in this study. The risk factors for thrombocytopenia were identified using univariate analysis of patient characteristics, disease type, and laboratory values immediately before the start of treatment. Variables with p<0.2 identified in the univariate analysis were used as independent variables in the multivariate analysis. This analysis identified "creatinine clearance (CCr) <60 mL/min" as a significant factor (odds ratio, 4.790; 95% confidence interval [CI], 1.380-16.70; p=0.014). Subsequently, time in days to the initial platelet transfusion after the initial administration of AZA was analyzed using the log-rank test. The overall median time in days to platelet transfusion was 370 days. The log-rank test was used to determine the influence of patient characteristics, disease type, and laboratory values immediately before the start of treatment. The subsequent Cox proportional hazard regression analysis using variables with p<0.2 as independent variables identified "hemoglobin (Hb) <8.0 g/dL" as a significant factor (hazard ratio, 2.143; 95% CI, 1.001-4.573; p=0.048). The results of this study led to the following clinical implications: first, patients with CCr of <60 mL/min at the start of treatment should be treated with caution due to the risk of thrombocytopenia. Second, patients with Hb of <8.0 g/dL at the start of treatment may require platelet transfusion in the early stage of treatment.

460Social inequalities in second-hand smoking among Japanese adults: A repeated cross-sectional study

Background

We aimed to examine the association between educational history and second-hand smoke (SHS) exposure in Japanese adults.

Methods

We conducted a repeated cross-sectional study using data from the 2007-2011 baseline and the 2013-2016 follow-up survey in a Japanese suburban area. Overall, 5,562 male and 5,381 female non-smokers participated in the study, which evaluated the SHS exposure and educational history of the participants through self-reported questionnaires. We performed a multilevel ordered logistic regression analysis with survey year as the first level and the individual as the second level, SHS exposure as the dependent variable, educational history as the explanatory variable, and age, smoking history, marital status as covariates, stratified by gender and working status.

Results

The prevalence of SHS exposure was 45.4% in males and 41.9% in females in the 2007-2011 survey, and 31.6% in males and 28.7% in females in the 2013-2016 survey. Multilevel analysis indicated that less educational history was associated with higher SHS exposure in both genders (among males, the odds ratio compared with ≥13 years was 1.75 for 10-12 years and 1.64 for ≤9 years; among females, it was 1.79 for 10-12 years and 2.43 for ≤9 years). Stratified analysis by working status showed that for females, education-based inequalities in SHS exposure more strongly impacted for workers than non-workers (p for interaction &lt;0.001).

Conclusions

Education-based inequalities in SHS exposure exist in Japan and might be severe among female workers.

Key messages

Measures against SHS in Japan should be promoted to reduce social and gender inequalities.

The Impact of Job Conditions on Health-Related Quality of Life among Working Japanese Older Adults: A Five-Year Longitudinal Study Using J-MICC Okazaki Study Data

OBJECTIVES

The number of older adults who continue working after retirement is increasing in Japan. Little is known about how job conditions affect older adults' health. We examined the association between job conditions and health-related quality of life (HRQOL) during a five-year follow-up study.

METHODS

This study included participants aged 65 years or older from the Japan Multi-Institutional Collaborative Cohort Study in the Okazaki area recruited at baseline between 2007 and 2011 and followed up five years later. Participants completed a self-reported questionnaire on the physical and mental health aspects of HRQOL (SF-8™), employment status, and job conditions (job satisfaction, skill use, and job suitability).

RESULTS

Data of 1,146 men and 522 women were analyzed (mean age: 69.1 and 68.6 years, respectively). Generalized mixed linear regression analysis revealed that, compared to the not-working group, skill use was positively associated with mental health aspects among men (skill use × time: β = 0.16, SE = 0.08, p < 0.05), while poor job satisfaction and job suitability were negatively associated with mental health aspects among women (job satisfaction, not satisfied × time: β = -0.93, SE = 0.47, p < 0.05; job suitability, not suitable × time: β = -1.06, SE = 0.50, p < 0.05).

CONCLUSIONS

Regarding job conditions among older adults, skill use in men was marginally associated with mental health, and poor job satisfaction and suitability in women were negatively associated with mental health. Considering the job conditions of older workers is necessary to protect their mental health.

The impact of marital transitions on vegetable intake in middle-aged and older Japanese adults: a five-year longitudinal study

Background

Marital transitions are associated with adverse health events, such as mortality and cardiovascular disease. Since marital transitions (eg, becoming widowed) are unavoidable life events, it is necessary to identify modifiable intermediate outcomes. Thus, we examined the association between marital transitions and vegetable intake among middle-aged and older Japanese adults.

Methods

This longitudinal study included Japanese adults aged 40–79 years who received an annual health checkup between 2007 and 2011 (baseline) and 5 years later (follow-up). Marital transitions were classified as whether and what type of transition occurred during the 5-year period and comprised five groups: consistently married, married to widowed, married to divorced, not married to married, and remained not married. Changes in total vegetable, green and yellow vegetable, and light-colored vegetable intake from baseline to follow-up were calculated using the Food Frequency Questionnaire.

Results

Data from 4,813 participants were analyzed (mean age, 59.4 years; 44.1% women). Regarding marital transitions, 3,960 participants were classified as “consistently married,” 135 as “married to widowed,” 40 as “married to divorced,” 60 as “not married to married,” and 529 as “remained not married.” Multivariable linear regression analysis revealed that compared to consistently married, married to widowed was inversely associated with the change in total vegetable intake (β = −16.64, SE = 7.68, P = 0.030) and light-colored vegetable intake (β = −11.46, SE = 4.33, P = 0.008).

Conclusion

Our findings suggest that being widowed could result in a reduced intake of vegetables. Hence, dietary counseling according to marital situation is necessary.

Association Between Second-hand Smoke Exposure and Depressive Symptoms Among Japanese Adults: A Cross-sectional Study

Background

Second-hand smoke exposure has been associated with poor mental health. However, among Japanese adults, little is known about the association between second-hand smoking and depressive symptoms. We examined this association in a cross-sectional study among a Japanese general adult population sample.

Methods

Japanese adults were recruited from the Japan Multi-Institutional Collaborative Cohort Study in the Okazaki area between 2012 and 2017. Second-hand smoke exposure and smoking status were assessed using a self-administered questionnaire. Based on their frequency of exposure to second-hand smoke, non-smokers and smokers were categorized as “almost never,” “sometimes,” and “almost every day”. Depressive symptoms were defined by a Kessler 6 score ≥5 points. We performed a multivariable Poisson regression analysis to obtain adjusted prevalence ratios (PRs) and 95% confidence intervals (CIs) for depressive symptoms.

Results

Overall, 5,121 participants (4,547 non-smokers and 574 smokers) were included whose mean age was 63.6 (standard deviation [SD], 10.3) years for non-smokers and 59.33 (SD, 10.2) years for smokers. The association between second-hand smoking and depressive symptoms was significant among non-smokers, but not among smokers. Among non-smokers, PRs compared with “almost never” were 1.25 (95% CI, 1.09–1.42) for “sometimes” and 1.41 (95% CI, 1.09–1.84) for “almost every day” (P for trend <0.001); among smokers, PRs compared with “almost never” were 1.30 (95% CI, 0.82–2.06) for “sometimes” and 1.44 (95% CI, 0.90–2.33) for “almost every day” (P for trend = 0.144).

Conclusions

Second-hand smoking and depressive symptoms were associated among non-smokers. Our findings indicate the importance of tobacco smoke control for mental health.

Nutritional factors affecting length of hospital stay in patients undergoing cardiovascular surgery

Cardiovascular surgery is a highly invasive intervention that is often performed in elderly patients at risks of complications because of malnutrition and reduced immunity. This study investigated nutritional factors that affected length of hospital stay in patients undergoing cardiovascular surgery. Among 68 patients who underwent surgery at the Department of Cardiovascular Surgery of Gifu Municipal Hospital between April 2013 and March 2015, 55 with complete data were included in the analysis. Data on serum albumin (ALB), transferrin (Tf), pre-albumin (PA) and retinol binding protein (RBP) levels were collected. The median length of hospital stay was 29 days (stays of ≥30 days were considered long-term hospitalization). Multivariate analysis (multiple logistic regression) included age (≥ 65 years), sex (female), and ALB (≤ 3.0 g/dL), Tf (≤ 150.0 mg/dL), PA (≤ 10.0 mg/dL) and RBP (≤ 1.5 mg/dL) levels. ALB [odds ratio (OR) 10.37, 95% CI (confidence interval): 1.185-90.80, P = 0.035] and Tf [OR 4.743, 95% CI: 1.375-16.36, P = 0.014] were significantly associated with length of hospital stay. Nutritional management of patients and careful monitoring of ALB and Tf levels can shorten length of hospital stay in patients undergoing cardiovascular surgery.

Cost utility analysis of pharmacist counseling care for breast cancer chemotherapy outpatients

Chemotherapy for cancer is increasingly implemented in the outpatient setting. Pharmacists contribute to cancer treatment by conducting counseling during outpatient chemotherapy visits. They provide guidance on drug treatment, side effects, and side effect countermeasures on every visit. However, there have been few economic evaluations of pharmacist involvement in outpatient chemotherapy. Therefore, we performed a cost utility analysis. We assigned usual care (control) and pharmacist counseling to two groups of 19 patients receiving outpatient chemotherapy for breast cancer at Gifu Municipal hospital. Quality of life was measured at three timepoints before and during chemotherapy treatment using the EuroQol 5 dimension instrument (EQ-5D). EQ-5D values across the timepoints were 0.831, 0.757, and 0.791 for the control group, and 0.882, 0.883, and 0.921 for the pharmacist counseling group. The additional cost in the pharmacist counseling group was 2,227 yen per counseling session. The change in quality-adjusted life years (QALY) was a maximum of -0.021±0.186 in the control group and 0.007±0.199 in the pharmacist counseling group. The maximum cost for one QALY was 1,360,558 yen (≈12,460 US dollars). Pharmacists' counseling in outpatient cancer chemotherapy for breast cancer patients had an acceptable incremental cost-effect ratio, contributing to improved patient quality of life without significant additional expenditure to healthcare.

Towards characterization of photo-excited electron transfer and catalysis in natural and artificial systems using XFELs

The ultra-bright femtosecond X-ray pulses provided by X-ray Free Electron Lasers (XFELs) open capabilities for studying the structure and dynamics of a wide variety of biological and inorganic systems beyond what is possible at synchrotron sources. Although the structure and chemistry at the catalytic sites have been studied intensively in both biological and inorganic systems, a full understanding of the atomic-scale chemistry requires new approaches beyond the steady state X-ray crystallography and X-ray spectroscopy at cryogenic temperatures. Following the dynamic changes in the geometric and electronic structure at ambient conditions, while overcoming X-ray damage to the redox active catalytic center, is key for deriving reaction mechanisms. Such studies become possible by using the intense and ultra-short femtosecond X-ray pulses from an XFEL, where sample is probed before it is damaged. We have developed methodology for simultaneously collecting X-ray diffraction data and X-ray emission spectra, using an energy dispersive spectrometer, at ambient conditions, and used this approach to study the room temperature structure and intermediate states of the photosynthetic water oxidizing metallo-protein, photosystem II. Moreover, we have also used this setup to simultaneously collect the X-ray emission spectra from multiple metals to follow the ultrafast dynamics of light-induced charge transfer between multiple metal sites. A Mn-Ti containing system was studied at an XFEL to demonstrate the efficacy and potential of this method.

Charge transfer to ground-state ions produces free electrons

Inner-shell ionization of an isolated atom typically leads to Auger decay. In an environment, for example, a liquid or a van der Waals bonded system, this process will be modified, and becomes part of a complex cascade of relaxation steps. Understanding these steps is important, as they determine the production of slow electrons and singly charged radicals, the most abundant products in radiation chemistry. In this communication, we present experimental evidence for a so-far unobserved, but potentially very important step in such relaxation cascades: Multiply charged ionic states after Auger decay may partially be neutralized by electron transfer, simultaneously evoking the creation of a low-energy free electron (electron transfer-mediated decay). This process is effective even after Auger decay into the dicationic ground state. In our experiment, we observe the decay of Ne²⁺ produced after Ne 1s photoionization in Ne-Kr mixed clusters.

Time-Resolved Measurement of Interatomic Coulombic Decay Induced by Two-Photon Double Excitation of Ne_{2}

The hitherto unexplored two-photon doubly excited states [Ne^{*}(2p^{-1}3s)]_{2} were experimentally identified using the seeded, fully coherent, intense extreme ultraviolet free-electron laser FERMI. These states undergo ultrafast interatomic Coulombic decay (ICD), which predominantly produces singly ionized dimers. In order to obtain the rate of ICD, the resulting yield of Ne_{2}^{+} ions was recorded as a function of delay between the extreme ultraviolet pump and UV probe laser pulses. The extracted lifetimes of the long-lived doubly excited states, 390(-130/+450)  fs, and of the short-lived ones, less than 150 fs, are in good agreement with ab initio quantum mechanical calculations.

Slow Interatomic Coulombic Decay of Multiply Excited Neon Clusters

Ne clusters (∼5000  atoms) were resonantly excited (2p→3s) by intense free electron laser (FEL) radiation at FERMI. Such multiply excited clusters can decay nonradiatively via energy exchange between at least two neighboring excited atoms. Benefiting from the precise tunability and narrow bandwidth of seeded FEL radiation, specific sites of the Ne clusters were probed. We found that the relaxation of cluster surface atoms proceeds via a sequence of interatomic or intermolecular Coulombic decay (ICD) processes while ICD of bulk atoms is additionally affected by the surrounding excited medium via inelastic electron scattering. For both cases, cluster excitations relax to atomic states prior to ICD, showing that this kind of ICD is rather slow (picosecond range). Controlling the average number of excitations per cluster via the FEL intensity allows a coarse tuning of the ICD rate.

Interatomic Coulombic decay cascades in multiply excited neon clusters

In high-intensity laser light, matter can be ionized by direct multiphoton absorption even at photon energies below the ionization threshold. However on tuning the laser to the lowest resonant transition, the system becomes multiply excited, and more efficient, indirect ionization pathways become operative. These mechanisms are known as interatomic Coulombic decay (ICD), where one of the species de-excites to its ground state, transferring its energy to ionize another excited species. Here we show that on tuning to a higher resonant transition, a previously unknown type of interatomic Coulombic decay, intra-Rydberg ICD occurs. In it, de-excitation of an atom to a close-lying Rydberg state leads to electron emission from another neighbouring Rydberg atom. Moreover, systems multiply excited to higher Rydberg states will decay by a cascade of such processes, producing even more ions. The intra-Rydberg ICD and cascades are expected to be ubiquitous in weakly-bound systems exposed to high-intensity resonant radiation.

Interatomic Coulombic decay (ICD) is a relaxation of an atom in a weakly bound environment by the transfer of excess energy to ionize the neighbouring atom. Here the authors observe intra-Rydberg ICD in neon clusters, which is a decay that involves the ionization of Rydberg atoms in the cluster.

Femtosecond charge and molecular dynamics of I-containing organic molecules induced by intense X-ray free-electron laser pulses

We studied the electronic and nuclear dynamics of I-containing organic molecules induced by intense hard X-ray pulses at the XFEL facility SACLA in Japan. The interaction with the intense XFEL pulse causes absorption of multiple X-ray photons by the iodine atom, which results in the creation of many electronic vacancies (positive charges) via the sequential electronic relaxation in the iodine, followed by intramolecular charge redistribution. In a previous study we investigated the subsequent fragmentation by Coulomb explosion of the simplest I-substituted hydrocarbon, iodomethane (CH₃I). We carried out three-dimensional momentum correlation measurements of the atomic ions created via Coulomb explosion of the molecule and found that a classical Coulomb explosion model including charge evolution (CCE-CE model), which accounts for the concerted dynamics of nuclear motion and charge creation/charge redistribution, reproduces well the observed momentum correlation maps of fragment ions emitted after XFEL irradiation. Then we extended the study to 5-iodouracil (C₄H₃IN₂O₂, 5-IU), which is a more complex molecule of biological relevance, and confirmed that, in both CH₃I and 5-IU, the charge build-up takes about 10 fs, while the charge is redistributed among atoms within only a few fs. We also adopted a self-consistent charge density-functional based tight-binding (SCC-DFTB) method to treat the fragmentations of highly charged 5-IU ions created by XFEL pulses. Our SCC-DFTB modeling reproduces well the experimental and CCE-CE results. We have also investigated the influence of the nuclear dynamics on the charge redistribution (charge transfer) using nonadiabatic quantum-mechanical molecular dynamics (NAQMD) simulation. The time scale of the charge transfer from the iodine atomic site to the uracil ring induced by nuclear motion turned out to be only ∼5 fs, indicating that, besides the molecular Auger decay in which molecular orbitals delocalized over the iodine site and the uracil ring are involved, the nuclear dynamics also play a role for ultrafast charge redistribution. The present study illustrates that the CCE-CE model as well as the SCC-DFTB method can be used for reconstructing the positions of atoms in motion, in combination with the momentum correlation measurement of the atomic ions created via XFEL-induced Coulomb explosion of molecules.

Risk factors for developing infusion reaction after rituximab administration in patients with B-cell non-Hodgkin's lymphoma

Rituximab (RTX), a monoclonal antibody against CD20, is known to cause fewer side effects than conventional anti-cancer drugs; however, infusion reaction (IR), which is specific to monoclonal antibody therapy, is frequently triggered by RTX. Therefore, we designed this study to identify risk factors based on clinical test values for developing IR after RTX administration. Eighty-nine patients with B-cell non-Hodgkin's lymphoma who had received RTX for the first time between February 2010 and March 2013, at the Gifu Municipal Hospital were enrolled as subjects. Analysis of data was conducted for 87 patients, after excluding patients whose data were missing. Univariate analysis showed significant differences in the number of patients exhibiting a soluble interleukin-2 receptor (sLL-2R) level > 2,000 U/L and hemoglobin (Hb) < lower standard limit (LSL) between the IR and non-IR groups. Multivariate analysis showed significant differences with respect to slL-2R > 2,000 U/L [odds ratio (OR), 4.463; 95% confidence interval (Cl), 1.262-15.779; P = 0.020], Hb < LSL [OR, 3.568; 95% CI, 1.071-11.890; P = 0.038], and steroid administration [OR, 0.284; 95% Cl, 0.094-0.852; P = 0.025]. Our findings show that sIL-2R > 2,000 U/L, Hb < LSL, and a lack of steroid premedication are risk factors for developing IR following RTX treatment.

Deep inner-shell multiphoton ionization by intense x-ray free-electron laser pulses

We have investigated multiphoton multiple ionization dynamics of xenon atoms using a new x-ray free-electron laser facility, SPring-8 Angstrom Compact free electron LAser (SACLA) in Japan, and identified that Xe(n+) with n up to 26 is produced at a photon energy of 5.5 keV. The observed high charge states (n≥24) are produced via five-photon absorption, evidencing the occurrence of multiphoton absorption involving deep inner shells. A newly developed theoretical model, which shows good agreement with the experiment, elucidates the complex pathways of sequential electronic decay cascades accessible in heavy atoms. The present study of heavy-atom ionization dynamics in high-intensity hard-x-ray pulses makes a step forward towards molecular structure determination with x-ray free-electron lasers.

Second-order autocorrelation of XUV FEL pulses via time resolved two-photon single ionization of He

Second-order autocorrelation spectra of XUV free-electron laser pulses from the Spring-8 Compact SASE Source (SCSS) have been recorded by time and momentum resolved detection of two-photon single ionization of He at 20.45 eV using a split-mirror delay-stage in combination with high-resolution recoil-ion momentum spectroscopy (COLTRIMS). From the autocorrelation trace we extract a coherence time of 8 ± 2 fs and a mean pulse duration of 28 ± 5 fs, much shorter than estimations based on electron bunch-length measurements. Simulations within the partial coherence model [Opt. Lett. 35, 3441 (2010)] are in agreement with experiment if a pulse-front tilt across the FEL beam diameter is taken into account that leads to a temporal shift of about 6 fs between both pulse replicas.

Three-electron interatomic Coulombic decay from the inner-valence double-vacancy states in NeAr

We have unambiguously identified interatomic Coulombic decay in NeAr from the inner-valence double-vacancy state Ne-Ar(2+)(3s(-2)) to outer-valence triple-vacancy states Ne(+)(2p(-1))-Ar(2+)(3p(-2)) by momentum-resolved electron-ion multicoincidence. This is the first observation of interatomic Coulombic decay where three electrons (3e) participate. The results suggest that this 3e interatomic Coulombic decay is significantly faster than other competing processes like fluorescence decay and charge transfer via curve crossing.

Electron-transfer-mediated decay and interatomic Coulombic decay from the triply ionized states in argon dimers

We report the first observation of electron-transfer-mediated decay (ETMD) and interatomic Coulombic decay (ICD) from the triply charged states with an inner-valence vacancy, using the Ar dimer as an example. These ETMD and ICD processes, which lead to fragmentation of Ar(3+)-Ar into Ar(2+)-Ar(2+) and Ar(3+)-Ar+, respectively, are unambiguously identified by electron-ion-ion coincidence spectroscopy in which the kinetic energy of the ETMD or ICD electron and the kinetic energy release between the two fragment ions are measured in coincidence.

Cold-target recoil-ion momentum spectroscopy for diagnostics of high harmonics of the extreme-ultraviolet free-electron laser light source at SPring-8

We have developed a cold-target recoil-ion momentum spectroscopy apparatus dedicated to the experiments using the extreme-ultraviolet light pulses at the free-electron laser facility, SPring-8 Compact SASE Source test accelerator, in Japan and used it to measure spatial distributions of fundamental, second, and third harmonics at the end station.

Fragmentation channels of K-shell excited rare-gas clusters studied by multiple-ion coincidence momentum imaging

Multiple-ion coincidence momentum imaging experiments were carried out for K-shell (1s) excited Ar clusters containing about 130 atoms and Kr clusters containing about 30, 90, and 160 atoms. The time-of-flight spectra reveal that the major products of the Coulomb explosion are singly charged ions. With increasing the number of charges generated in clusters, the momentum of monomer ions such as Ar(+) and Kr(+) increases, while that of cluster ions such as Ar(3) (+), Kr(2) (+), and Kr(3) (+) decreases. This observation indicates the site-specific decay process that the heavier ions appear in the central part of clusters. We have also investigated the momentum distribution in various fragmentation channels and the branching ratio of each channel at the Coulomb explosion. When the number N(coin) of coincidently detected ions is four, for example, the most frequent channel from Kr clusters containing 30 atoms is to emit simply four Kr(+) ions, but Kr(2) (+) ions participate in the fragmentation from the larger Kr clusters. The fragmentation channel in which two Ar(2) (+) ions are emitted becomes dominant with increasing N(coin), and the average momentum of Ar(2) (+) ion in this channel is larger than that in the channels where only single Ar(2) (+) is emitted.

Electron-ion-coincidence spectra of K-shell excited Ne, Ar, and Kr clusters

Electron-ion-coincidence spectra were recorded for K-shell excited krypton, argon, and neon clusters covering the size range from 1 atom to about 3000 atoms by utilizing hard x-ray undulator beamlines. Multiply charged ions Rz+(z>or=2) and singly charged ions Rn+(n>or=1) are observed as cluster fragments, and their relative abundance exhibits a characteristic dependence on the average cluster size N. It is expected from these results that the charges generated on the cluster surface are strongly localized while those in the cluster core are more delocalized. The estimated charge separation distance increases with N, and it is longer for lighter elements.

Theoretical studies on tunneling ionizations from the doubly degenerate highest occupied molecular orbitals of benzene in intense laser fields

Combining our generalized Keldysh theory [Sov. Phys. JETP 20, 1307 (1965)] with the molecular orbital theory, the authors theoretically study tunneling ionizations of neutral benzene in intense linearly polarized Ti:sapphire laser fields (800 nm). They consider the ionizations from the highest occupied molecular orbitals (HOMOs) of the ground electronic state. The double degeneracy of the HOMOs is properly taken into account. In the theory, molecular ionizations consist of the individual ionizations from each atom and the quantum interferences between them. The theory reproduces the experimental data well. The authors also show that the polarization dependence of the ionization rates is strongly influenced by the quantum interferences.

Coulomb explosion of K-shell ionized krypton clusters studied by multiple-ion coincidence momentum imaging

The Coulomb explosion of K-shell ionized krypton clusters with an average size N of 160 has been studied by electron-multiple-ion-coincidence measurements in which the time-of-flight (TOF) of ions was measured by using a position sensitive detector. The authors have sorted the TOF spectra by the number of coincidence ion signals, Ncoin, and found that singly charged fragment ions such as Kr+, Kr2+, and Kr3+ are dominant for Ncoin>or=2, and that multiply charged ions are detected mainly for Ncoin=1. The Ncoin dependence of the peak widths in the TOF spectra reveals that the average momentum of the Kr+ ions increases with Ncoin, while those of Kr2+ and Kr3+ decrease. These results have been more directly confirmed by the momentum imaging measurements. The authors propose that the heavier ions are produced in the central part of clusters where the Coulomb interactions from the surrounding ions are more effectively canceled out due to the higher symmetry.

Control of nonadiabatic dissociation dynamics with the use of laser-induced wave packet interferences

Based on wave packet interferences induced by a stationary laser field, a simple way of controlling nonadiabatic dissociation dynamics is proposed. We treat a simple two-state model of diatomic molecules. In this model, there exist two dissociative potential energy curves which cross and are strongly coupled at an internuclear distance, and thus dissociations into one channel are predominant. We propose a control scheme to selectively dissociate a molecule into any favorite channel by choosing the laser frequency and intensity appropriately. The semiclassical estimation of desirable laser parameters can be performed easily by regarding the dissociation processes as nonadiabatic transitions between the Floquet states. The agreement between the semiclassical estimation and the quantum wave packet calculation is found to be satisfactory in the high frequency region (> or =1000 cm(-1)) where the Floquet state picture is valid. In the low frequency region (<1000 cm(-1)), on the other hand, there are discrepancies between them due to the invalidity of the Floquet picture and the dissociation probability is sensitive to the laser phase. This control scheme is applied to the predissociation dynamics of NaI, NaI-->Na+I.

Theoretical studies on tunneling ionizations of helium atom in intense laser fields

Our generalized Keldysh theory is applied to the simplest many-electron atom, helium atom. For the single ionization (He-->He(+)+e) we derive a compact rate formula, which does not contain any series summation or integral and thus is as simple as the Ammosov-Delone-Krainov ionization rates. In addition to its simplicity, our formula can explicitly show the wavelength dependence. Furthermore a simple form of the angular distribution of the photoelectron is available. Our compact formula agrees well with both the exact numerical calculations [A. Scrinzi et al., Phys. Rev. Lett. 83, 706 (1999)] and experimental data [B. Walker et al., Phys. Rev. Lett. 73, 1227 (1994)] in the intensity range of I<5x10(15) Wcm(2). In higher intensity regions, we suggest to utilize another simple formula which is valid in the tunneling limit.

Effect of quantum interference on tunneling photoionization rates of N2 and O2 molecules

In this work, we reexamine the photoionization rates of N(2) and O(2) molecules using the previously published photoionization rate theory which is based on the original atomic Keldysh theory [K. Mishima et al., Phys. Rev. A 66, 033401 (2002); ibid.66, 053408 (2002)]. We have found that the constructive quantum interference takes place for N(2) molecule while the destructive quantum interference plays an important role for O(2) molecule. This is consistent with the experimental and theoretical results reported in the literature. The formulas derived in this paper clearly show that this is due to the different symmetries of the valence orbitals of N(2) and O(2) molecules.

Towards the realization of the quantum chemistry approach to tunneling photoionization processes in strong laser fields

Based on Keldysh's theory, we investigate the possibility to use the molecular orbital theoretic approach for calculating the tunneling photoionization rates of molecules. As a demonstration, we concentrate on the 1s state of the hydrogen atom as the initial state.

Size-selective extended X-ray absorption fine structure spectroscopy of free selenium clusters

In a recent paper [M. Yao et al., J. Synchrotron Radiat. 8, 542 (2001)]], we proposed a new method for the size-selective EXAFS (extended x-ray absorption fine structure) of neutral-free clusters, in which not only the x-ray absorption process but also the deexcitation processes are utilized as the structural information. In order to verify this method experimentally, we have developed the synchronous measurements of EXAFS and photoelectron photoion coincidence and carried them out for a Se cluster beam by utilizing the third-generation intense x-ray source. The EXAFS spectra for Se small clusters have been obtained and compared critically with theoretical predictions.

A new method for the size-selective EXAFS of neutral free clusters

Recently we have measured Photoelectron Photoion Coincidence (PEPICO) spectra for selenium dimer Se2 and larger species such as Se5 at the beamline BL-12C in Photon Factory. The PEPICO spectra reveal that the multiply charged ions, Se(z+), are produced as a result of de-excitation processes following the inner-shell excitation and fragmented to atomic ions owing to the Coulomb explosion. The branching ratios from the parent clusters to the daughter ions exhibit clear dependence on the size of the parent clusters. In particular, the branching ratios in the non-resonant absorption region are well reproduced by assuming that the charges are randomly distributed within the clusters before the Coulomb explosion. Based upon these findings, we propose a new method for the size-selective EXAFS of neutral free clusters by utilizing the PEPICO measurements.

Causes of maternal mortality in Japan

CONTEXT

Japan's maternal mortality rate is higher than that of other developed countries.

OBJECTIVES

To identify causes of maternal mortality in Japan, examine attributes of treating facilities associated with maternal mortality, and assess the preventability of such deaths.

DESIGN AND SETTING

Cross-sectional study of maternal deaths occurring in Japan between January 1, 1991, and December 31, 1992.

SUBJECTS

Of 230 women who died while pregnant or within 42 days of being pregnant, 197 died in a hospital and had medical records available, 22 died outside of a medical facility, and 11 did not have records available.

MAIN OUTCOME MEASURES

Maternal mortality rates per 100,000 live births by cause (identified by death certificate review and information from treating physicians or coroners); resources and staffing patterns of facilities where deaths occurred; and preventability of death, as determined by a 42-member panel of medical specialists.

RESULTS

Overall maternal mortality was 9.5 per 100,000 births. Hemorrhage was the most common cause of death, occurring in 86 (39%) of 219 women. Seventy-two (37%) of 197 deaths occurring in facilities were deemed preventable and another 32 (16%) possibly preventable. Among deaths that occurred in a medical facility with an obstetrician on duty, the highest rate of preventable deaths (4.09/100,000 live births) occurred in facilities with 1 obstetrician. Among the 72 preventable deaths, 49 were attributed to 1 physician functioning as the obstetrician and anesthetist. While the unpreventable maternal death rate was highest in referral facilities, the preventable maternal death rate was 14 times lower in referral facilities than in transferring facilities.

CONCLUSIONS

Inadequate obstetric services are associated with maternal mortality in Japan. Reducing single-obstetrician only delivery patterns and establishing regional 24-hour inpatient obstetrics facilities for high-risk cases may reduce maternal mortality in Japan. JAMA. 2000;283:2661-2667.

Is the Gauer-Henry reflex important for immersion diuresis in men?

BACKGROUND

This study examines the relationship between the threshold for plasma vasopressin concentration [PVP] responses and diuresis (Gauer-Henry reflex), and tests the hypothesis that water intake would not influence diuresis.

METHODS

Eight men (19-25 yr) underwent four treatments: euhydration in air (Eu-air), euhydration in water immersion (Eu-H2O), and with prior 3.6% hypohydration in air (Hypo-air), and hypohydration in immersion (Hypo-H2O). Ad libitum drinking was allowed during the 3-h experimental and 1-h recovery periods.

RESULTS

Drinking was greatest during the first 10 min: 3.5 ml x kg(-1) with Hypo-air (450 ml x 3 h(-1)) and only 1.7 ml x kg(-1) (p < 0.05) with Hypo-H2O (235 ml x 3 h(-1)). At 1 h, concomitant [PVP] decreased from a control level of 6.6+/-1.5 to 4.0+/-1 .0 pg x ml(-1) (delta = 2.6 pg x ml(-1), p < 0.05) with Hypo-air, and from 5.9+/-0.6 to 2.3+/-0.2 pg x ml(-1) (delta = 3.6 pg x ml(-1), p < 0.05) with Hypo-H2O. Urine flow was unchanged from control level (<1.0 ml x min(-1)) with Hypo-air, Hypo-H2O, and Eu-air, but increased to 4-5 ml x min(-1) with Eu-H2O. Neither water intake volume nor urine flow was related to the magnitude of [PVP] depression. Regression of Uosm/Posm ratio on [PVP] and urine flow indicated that [PVP] above 2 pg x ml(-1) did not affect urine flow. Thus, ad libitum water intake in previously hypohydrated subjects did not affect urine flow or the decrease in [PVP]. The threshold [PVP] to initiate significant diuresis was about 2 pg x ml(-1), and significant diuresis can occur with no change in [PVP] maintained at about 1 pg x ml(-1) during immersion in euhydrated subjects.

CONCLUSIONS

Thus, it appears that the Gauer-Henry reflex is not the major mechanism for immersion-induced diuresis. Clearly, other diuretic factors are also involved.

Intracranial haemorrhage as a cause of maternal mortality during 1991-1992 in Japan: a report of the Confidential Inquiry into Maternal Deaths Research Group in Japan

OBJECTIVE

To determine the causes of maternal deaths by intracranial haemorrhage in Japan.

DESIGN

Retrospective analysis of records relating to maternal deaths in 1991 and 1992.

SAMPLES

Two hundred and thirty maternal deaths, including 25 cases of primary intracranial haemorrhage and two cases with secondary bleeding.

METHODS

Attending doctors were interviewed and completed a 600-item data collection instrument for each maternal death. An expert committee reviewed the data for each death to determine whether the maternal deaths could have been prevented.

MAIN OUTCOME MEASURES

Preventability of maternal death from intracranial haemorrhage treated in obstetric and emergency services in Japan.

RESULTS

Half of the primary intracranial haemorrhages occurred during pregnancy, 20% during labour, and 30% in the postnatal period. Neurosurgeons considered that there were only three women in whom surgical drainage was indicated. The committee determined that there was only one maternal death which had a > or = 70% of being prevented. After detailed discussion of each case, 60% of the women (15/25) may have been saved by earlier and more intensive medical intervention.

CONCLUSIONS

These findings suggest that detailed history taking and early diagnosis of intracranial haemorrhage would be helpful. Regionalisation of obstetric emergency systems are necessary to reduce maternal deaths in Japan due to intracranial haemorrhage.

Counteracting moment device for reduction of earthquake-induced excursions of multi-level buildings

A vibration-control mechanism for beams and columns was presented in our previous report in which the earthquake force was transformed into a vibration-control force by using a gear train mechanism. In our previous report, however, only the principle of transforming the earthquake force into the control force was presented; the discussion for real structures and the design method were not presented. The present article provides a theoretical analysis of the column which is used in multi-layered buildings. Experimental tests were carried out for a model of multi-layered buildings in the frequency range of a principal earthquake wave. Theoretical results are compared to the experimental data. The optimal design of the control mechanism, which is of importance in the column design, is presented. Numerical calculations are carried out for the optimal design. It is shown that vibrations of the column involving the mechanism are suppressed remarkably. The optimal design method and the analytical results are applicable to the design of the column.

Type A aortic dissection involving a right-sided aortic arch

We report a rare case of a 39-year-old man with type A aortic dissection involving a right-sided aortic arch with the symptom of vascular ring. Computed tomography scanning and angiography were performed to define the extent of the dissection and the anatomy of the branching vessels. The ascending aorta was replaced through a median sternotomy and right thoracotomy using a hypothermic cardiopulmonary bypass associated with selective cerebral perfusion and partial circulatory arrest, and his symptom of vascular ring disappeared postoperatively.

Outbreak of severe infection due to adenovirus type 7 in a paediatric ward in Japan

Between November 1996 and January 1997, 14 patients were diagnosed as having infection caused by adenovirus type 7 in a paediatric ward of Asahikawa Kosei Hospital. The age range of the patients was from two months to five years. Their diseases and abnormal laboratory findings were pneumonia in all 14, leukocytopenia in 10, myositis in nine, gastroenteritis in eight, encephalitis in five, liver dysfunction in three, pleuritis in two, inappropriate secretion of antidiuretic hormone syndrome in two, and thrombocytopenia in two. The infected patients, except for the first had been hospitalized in the paediatric ward for treatment of another disease and re-admitted because of high fever and coughing a few days after improvement or discharge. It is thought that the cause of the outbreak was hospital-acquired infection.

[Left ventricular rupture following mitral valve replacement with preservation of posterior leaflet]

Left ventricular rupture following mitral valve replacement (MVR) with preservation of the posterior leaflet is presented. A 63-year-old man underwent combined AVR, MVR with preservation of the posterior leaflet and TAP under cardiopulmonary bypass with moderate hypothermiat to 28 degrees C and tepid blood cardioplegia. Although a 31-mm valve would fit to the mitral position, a 27 TEKNA was chosen for MVR. Beyond the cardiopulmonary bypass, a left ventricular rupture was found. Cardiopulmonary bypass was re-stated and the aortic clamp was replaced. After removal of the mitral valve prosthesis, an internal tear was detected below the anterolateral commissural area (Type I). The tear was repaired with two 3-0 monofilament buttressed sutures incorporated with felt strips and covered with a bovine pericardial patch by several interrupted pledgeted mattress sutures. Gelatin-resorcin-formaldehyde/Glutaraldehyde glue (GRF) was used to reinforce the ruptured myocardium and to fix a bovine pericardial patch to the affected ventricular wall. Then the prosthesis was re-seated. Although the aortic clamp time was 319 mins., the patient was weaned from the cardiopulmonary bypass easily with the prophylactic use of IABP. The patient was discharged and returned to his previous job.

Carotid baroreflex control of heart rate during acute exposure to simulated altitudes of 3,800 m and 4,300 m

To examine the baroreflex response in humans during acute high-altitude exposure, the carotid baroreflex cardiac responsiveness was studied using a neck chamber in seven unacclimatized male subjects. Measurements were made in a high-altitude chamber on separate days at sea level and during 1-h exposure at two different altitudes of 3,800 m [partial pressure of oxygen in inspired air (PI(O2)) = 90 mmHg] and 4,300 m (PI(O2) = 82 mmHg). R-R intervals were plotted against neck chamber pressures, and the baroreceptor response was analyzed by applying a four-parameter sigmoidal logistic function. The baroreceptor response curve shifted downward in either altitude, reflecting a tachycardic response at high altitude, and the magnitude of the shift was greater at 4,300 m than at 3,800 m. There was no change in the sigmoidal parameters at 3,800 m compared with sea level except for a reduction (P < 0.05) of the minimum R-R interval. At 4,300 m the maximal R-R range, slope coefficient, minimum R-R interval, and maximal gain of the curve decreased significantly (P < 0.05) compared with sea level values, whereas the centering point of the curve remained unchanged. These results suggest that hypoxia (PI(O2) = 82 mmHg) reduces the sensitivity of carotid baroreflex cardiac response.

Mechanism for changes in vasopressin during acute exposure at 3 atm abs air

Plasma arginine vasopressin (AVP) concentration is reduced in human subjects during prolonged saturation dive exposures of 4 atmospheres absolute (atm abs) and greater. The objectives of the present study were to determine if AVP would be reduced in eight male subjects during a 1-h exposure of 3 atm abs air and, if so, to determine the mechanisms responsible for the AVP response. Assessments of transmural central venous pressure (central venous pressure-esophageal pressure) and cardiac volume measurements were made to evaluate the possible role of cardiopulmonary receptors on the AVP response. Also, plasma osmolality (P(osmol)), venous blood gases, and mean corpuscular volume (MCV) were determined to evaluate potential effects of osmoreceptor and other fluid shifts on AVP release. AVP decreased (P < 0.05) by 0.5 microU/ml at 3 atm abs, whereas the transmural central venous pressure and cardiac volume remained unchanged throughout the experimental periods. A significant reduction (P < 0.05) in P(osmol) (by approximately 3 mosmol/kgH2O) was detected at 3 atm abs. Therefore, we conclude that the reduction in P(osmol) may cause the reduction in AVP during exposure to 3 atm abs pressure. The reduction in P(osmol) without water intake requires the postulation of an internal source of water. We propose that the threefold increase (P < 0.01) in venous PO2 and concomitant decrease (P < 0.05) in venous MCV suggest that the red blood cell may contribute to hypotonicity at 3 atm abs.

Ultralente insulin treatment of transient neonatal diabetes mellitus

In an infant with transient neonatal diabetes mellitus, control of the blood glucose concentration was attained with ultralente insulin treatment, without any episodes of hypoglycemia. We recommend subcutaneous injection of ultralente insulin, rather than lente or isophane (NPH) insulin, to avoid hypoglycemia during the treatment of transient neonatal diabetes mellitus.

Diving patterns of ama divers of Hegura Island, Japan

Daily diving patterns, especially depth-time profiles, were continuously recorded during the entire work shift in four cachido and four funado divers of Hegura Island, Japan. All Hegura divers (cachido and funado alike) were female and habitually wore wet suits. Cachidos dive free and unassisted from a boat or float, whereas funado divers are assisted by weighted descent and during the ascent by being pulled by a partner into a boat on the water surface. Both funado and cachido divers spent 250-280 min/day on the sea at their diving locations; the actual diving time was 100-120 min. The divers made 90-120 dives/day to a depth of 13-22 m, each dive lasting approximately 60 s, considerably longer and deeper than those observed and recorded previously in ama divers in the Chiba and Miura regions. These dive profiles are similar to those reported by Paulev in which he observed apparent signs of decompression sickness when the subject dived to a depth of 15-20 m 100 times in 5 h. The average bottom time for each dive of Hegura funados was 23.6 s which is approximately 10 s longer than that of Korean female ama. The rate of ascent in the funado divers was 1.5 m/s, which is nearly twice that of the cachido divers (0.8 m/s). The dive frequency of Hegura funados (109 dives/day) was greater than the Chiba male funados (23 dives/day). Accordingly, cumulative bottom time of Hegura funado was 48 min/day, whereas that of Chiba funado was 17 min/day.(ABSTRACT TRUNCATED AT 250 WORDS)

Responses of the circulatory system and muscle sympathetic nerve activity to head-down tilt in humans

These experiments were conducted to examine whether changes in central and peripheral hemodynamics were proportional to muscle sympathetic nerve activity (MSNA) during graded head-down tilt (HDT). Twelve healthy males (19-42 yr old) underwent HDT at 15 degrees and 30 degrees for 10 min each with a 10-min rest period between the trials. MSNA at 15 degrees HDT declined by 31 +/- 5% (P < 0.05) for burst rate and by 37 +/- 3% (P < 0.05) for total activity. At 30 degrees HDT, the reduction in MSNA was 51 +/- 5% for burst rate (P < 0.05 vs. 15 degrees HDT) and 46 +/- 5% for total activity (P < 0.05 vs. 15 degrees HDT). Stroke volume increased (P < 0.05) during both 15 degrees and 30 degrees HDT, but heart rate and blood pressure remained unchanged. A concurrent increase in central venous pressure (P < 0.05) and stroke volume with a reduction of thoracic impedance (P < 0.05) suggests that both pressure and volume in the atrium were elevated during HDT, and the magnitude of these changes was greater (P < 0.05) at 30 degrees HDT than at 15 degrees HDT. Forearm blood flow increased during HDT at both 15 degrees and 30 degrees, and the magnitude of the increase was greater (P < 0.05) at 30 degrees HDT. It is concluded that the magnitude of the loading of the cardiopulmonary mechanoreceptors during HDT was higher at 30 degrees in comparison to 15 degrees. This increased the afferent firing rate by the cardiopulmonary receptors and probably inhibited sympathetic outflow in the central nervous system.(ABSTRACT TRUNCATED AT 250 WORDS)

Mechanism of thirst attenuation during head-out water immersion in men

The purpose was to determine whether extracellular volume or osmolality was the major contributing factor for reduction of thirst in air and head-out water immersion in hypohydrated subjects. Eight males (19-25 yr) were subjected to thermoneutral immersion and thermoneutral air under two hydration conditions without further drinking: euhydration in water (Eu-H2O) and euhydration in air, and hypohydration in water (Hypo-H2O) and hypohydration in air (3.7% wt loss after exercise in heat). The increased thirst sensation with Hypo-H2O decreased (P < 0.05) within 10 min of immersion and continued thereafter. Mean plasma osmolality (288 +/- 1 mosmol/kgH2O) and sodium (140 +/- 1 meq/l) remained elevated, and plasma volume increased by 4.2 +/- 1.0% (P < 0.05) throughout Hypo-H2O. A sustained increase (P < 0.05) in stroke volume accompanied the prompt and sustained decrease in plasma renin activity and sustained increase (P < 0.05) in plasma atrial natriuretic peptide during Eu-H2O and Hypo-H2O. Plasma vasopressin decreased from 5.3 +/- 0.7 to 2.9 +/- 0.5 pg/ml (P < 0.05) during Hypo-H2O but was unchanged in Eu-H2O. These findings suggest a sustained stimulation of the atrial baroreceptors and reduction of a dipsogenic stimulus without major alterations of extracellular osmolality in Hypo-H2O. Thus it appears that vascular volume-induced stimuli of cardiopulmonary baroreceptors play a more important role than extracellular osmolality in reducing thirst sensations during immersion in hypohydrated subjects.

[A study of the relationship between diabetic neuropathy and diabetic retinopathy]

To evaluate the relationship between diabetic neuropathy and retinopathy, we examined autonomic nervous function, postural hypotension, nerve conduction velocity and coefficient of variation of R-R intervals. Forty-five non-insulin dependent diabetic cases were classified as no diabetic retinopathy (group A), simple diabetic retinopathy (group B) and proliferative diabetic retinopathy (group C). These groups did not differ in age or gender. The rate of postural hypotension (depression of systolic blood pressure over 30 mmHg) was 0% in group A, 7% in group Bs and 53% in group C. Nerve conduction velocity in both motor and sensory nerve was delayed over 20% in 0% of group A, 8% of group B, and 33% of group C. In CVR-R, 11% of group A and 7% of group B were decreased, and 44% (during rest) and 33% (during deep breathing) of group C was decreased. Between groups A and B there was no statistical difference. But group C had statistically significant difference from other groups, particularly in postural hypotension. Peripheral neuropathy might be closely related to diabetic retinopathy.