114 research outputs found

    Photoemission from the gas phase using soft x-ray fs pulses: An investigation of the space-charge effects

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    An experimental and computational investigation of the space-charge effects occurring in ultrafast photoelectron spectroscopy from the gas phase is presented. The target sample CF3_3I is excited by ultrashort (100 fs) far-ultraviolet radiation pulses produced by a free-electron laser. The modification of the energy distribution of the photoelectrons, i.e. the shift and broadening of the spectral structures, is monitored as a function of the pulse intensity. A novel computational approach is presented in which a survey spectrum acquired at low radiation fluence is used to determine the initial energy distribution of the electrons after the photoemission event. The spectrum modified by the space-charge effects is then reproduced by NN-body calculations that simulate the dynamics of the photoelectrons subject to the mutual Coulomb repulsion and to the attractive force of the positive ions. The employed numerical method allows to reproduce the complete photoelectron spectrum and not just a specific photoemission structure. The simulations also provide information on the time evolution of the space-charge effects on the picosecond scale. Differences with the case of photoemission from solid samples are highlighted and discussed. The presented simulation procedure constitutes an effective tool to predict and account for space-charge effect in time-resolved photoemission experiments with high-intensity pulsed sources.Comment: 18 pages, 4 figures, 1 tabl

    Predicting the outcome of chronic kidney disease by the estimated nephron number: The rationale and design of PRONEP, a prospective, multicenter, observational cohort study

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    <p>Abstract</p> <p>Background</p> <p>The nephron number is thought to be associated with the outcome of chronic kidney disease (CKD). If the nephron number can be estimated in the clinical setting, it could become a strong tool to predict renal outcome. This study was designed to estimate the nephron number in CKD patients and to establish a method to predict the outcome by using the estimated nephron number.</p> <p>Methods/Design</p> <p>The hypothesis of this study is that the estimated nephron number can predict the outcome of a CKD patient. This will be a multicenter, prospective (minimum 3 and maximum 5 years follow-up) study. The subjects will comprise CKD patients aged over 14 years who have undergone a kidney biopsy. From January 2011 to March 2013, we will recruit 600 CKD patients from 10 hospitals belonging to the National Hospital Organization of Japan. The primary parameter for assessment is the composite of total mortality, renal death, cerebro-cardiovascular events, and a 50% reduction in the eGFR. The secondary parameter is the rate of eGFR decline per year. The nephron number will be estimated by the glomerular density in biopsy specimens and the renal cortex volume. This study includes one sub-cohort study to establish the equation to calculate the renal cortex volume. Enrollment will be performed at the time of the kidney biopsy, and the data will consist of a medical interview, ultrasound for measurement of the kidney size, blood or urine test, and the pathological findings of the kidney biopsy. Patients will continue to have medical consultations and receive examinations and/or treatment as usual. The data from the patients will be collected once a year after the kidney biopsy until March 2016. All data using this study are easily obtained in routine clinical practice.</p> <p>Discussion</p> <p>This study includes the first trials to estimate the renal cortex volume and nephron number in the general clinical setting. Furthermore, this is the first prospective study to examine whether the nephron number predicts the outcome of CKD patients. The results from this study should provide powerful new tools for nephrologists in routine clinical practice.</p> <p>Trial registration</p> <p>UMIN-Clinical Trial Registration, UMIN000004784.</p

    Hypertension treatment status and ultrasonic cardiography findings in temporary housing residents after the Kumamoto earthquake: a cross-sectional study

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    Background: We aimed to investigate and report the relationship between hypertension treatment status and cardiac functions among temporary housing residents after the Kumamoto earthquake. Material and methods: Ultrasonic cardiography examinations were conducted for 56 residents at temporary housing complexes in Minami Aso village in Kumamoto Prefecture in December 2016. The subjects were divided into the following three groups according to the incidence of hypertension and the antihypertensive treatment status: normal (without hypertension), treated, and untreated. Subsequently, their cardiac functions were compared. Results: Age and BMI were found to be positive predictors for hypertension. Moreover, age, LAVI, and LVMI tended to be higher in the untreated group than in the treated group. Moderate or severe mitral regurgitation was significantly more common in the untreated group than in the treated group. Conclusions: Controlling blood pressure may help to prevent new cardiac diseases (e.g., valve regurgitation) among survivors after a major disaster. In addition, for survivors who are  severely affected by psychological stress, improving the mental stress support system may be an effective measure to reduce health problems

    Deep-vein thrombosis detection rates and consideration of the living environment in a tsunami disaster area during the disaster reconstruction phase: A cross-sectional study

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    Introduction: Tsunami victims of the Great East Japan Earthquake were screened for deep-vein thrombosis(DVT) in order to compare the DVT incidence rates between temporary and non-temporary housing residentgroups. Material and methods: Lower extremity venous ultrasonography was performed on 290 subjects (64 menand 226 women; mean age = 71.9 ± 7.9 years) at 44 months after the disaster. All subjects completedquestionnaires to gather information about their background factors which included the Kessler PsychologicalDistress Scale: K6. Results: The DVT detection rate was 10.7% in the temporary group. In the non-temporary group, it was 11.3%among the subjects who previously lived in temporary housing. For the subjects who were living in their own homes it was 9.2%. Psychological distress levels measured by K6 were significantly higher in the temporary housinggroup than in the non-temporary housing group. The multivariate analysis showed that the background factorassociated with DVT risk was SV (soleal vein) dilatation in all subjects as well as in the non-temporary housinggroup, while hypertension and use of sleeping pills were found to be the factors in the temporary housing group. Conclusions: DVT detection rates were similar between the temporary and non-temporary housing groups,and were higher than that in the Japanese general population. The psychological distress level of the tsunamivictims measured by K6 was also higher in the temporary housing group than in the non-temporary housinggroup. It is necessary to establish a long-term and awareness-raising disaster victim support system

    Effects of aerosol scattered radiation on minor atmospheric species concentrations in a one-dimensional model

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    The effects of solar radiation scattered by aerosols on minor atmospheric species concentrations were examined by a one-dimensional transport-kinetics model with radiative transfer model including the effects of absorption and multiple scattering by molecules and aerosols. The absorption and scattering of aerosols significantly affect the photodissociation rates of optically active species and lead to changes in the concentration profiles of atmospheric minor constituents. For example, a few percent decrease in the stratospheric ozone concentration is simulated for the increased aerosols. The sensitivity of the ozone concentrations to changes in the aerosol loads was also examined
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