Experimental Verification of the Chemical Sensitivity of Two-Site Double Core-Hole States Formed by an X-ray FEL

We have performed X-ray two-photon photoelectron spectroscopy (XTPPS) using the Linac Coherent Light Source (LCLS) X-ray free-electron laser (FEL) in order to study double core-hole (DCH) states of CO2, N2O and N2. The experiment verifies the theory behind the chemical sensitivity of two-site (ts) DCH states by comparing a set of small molecules with respect to the energy shift of the tsDCH state and by extracting the relevant parameters from this shift.Comment: 11 pages, 2 figure

Femtosecond X-ray-induced fragmentation of fullerenes

A new class of femtosecond, intense, short – wavelength lasers – the free-electron laser – has opened up new opportunities to investigate the structure and dynamics in many scientific areas. These new lasers, whose performance keeps increasing, enable the understanding of physical and chemical changes at an atomic spatial scale and on the time scale of atomic motion which is essential for a broad range of scientific fields. We describe here the interaction of fullerenes in the multiphoton regime with the Linac Coherent Light Source (LCLS) X-ray free-electron laser at SLAC National Laboratory. In particular, we report on new data regarding the ionization of Ho3N@C80 molecules and compare the results with our prior C60 investigation of radiation damage induced by the LCLS pulses. We also discuss briefly the potential impact of newly available instrumentation to physical and chemical sciences when they are coupled with FELs as well as theoretical calculations and modeling

The images of psychiatry scale: development, factor structure, and reliability.

BACKGROUND: This analysis is based on a survey questionnaire designed to describe medical educators' views of psychiatry and psychiatrists. Our goals in this paper were to assess the psychometric properties of the survey questions by (a) using exploratory factor analysis to identify the basic factor structure underlying 37 survey items; (b) testing the resulting factor structure using confirmatory factor analysis; and (c) assessing the internal reliability of each identified factor. To our knowledge, this is the first attempt to use these techniques to psychometrically assess a scale measuring the strength of stigma that medical educators attached to psychiatry. METHODS: Survey data were collected from a random sample of 1,059 teaching faculty in 23 academic teaching sites in 15 countries. We conducted exploratory and confirmatory factor analysis to identify the scale structure and Cronbach's alpha to assess internal consistency of the resulting scales. RESULTS: Results showed that a two-factor solution was the best fit for the data. Following exploratory factor analysis, we conducted confirmatory factor analysis on a split half of the sample. Results highlighted several items with low loadings. Excluding factors with low correlations and allowing for several correlated variances resulted in a good fitting model explaining 95% of the variance in the data. CONCLUSIONS: We identified two unidimensional scales. The Images Scale contained 11 items measuring stereotypic content concerning psychiatry and psychiatrists. The Efficacy of Psychiatry Scale contained 5 items addressing perceptions of the challenges and effectiveness of psychiatry as a discipline

Complete shutdown of microvascular perfusion upon hepatic cryothermia is critically dependent on local tissue temperature

Since microvascular dysfunction with complete circulatory arrest and, thus, prolongation of tissue ischaemia is considered a potential mechanism for cell necrosis following hepatic cryosurgery, we determined the temperature necessary for induction of complete nutritive perfusion failure in cryothermia-treated rat livers. After localization of the cryoprobe with seven thermocouples and application of a single or double freeze–thaw cycle, in vivo fluorescence microscopy of the cryoinjured left lobe was performed over a 2-h period using a computer-controlled stepping motor, which guaranteed analysis of the identical liver tissue segments with exact allocation of the thermocouples and thus determination of tissue temperature. Cryothermia resulted in a central non-perfused part of injury, surrounded by a heterogeneously perfused peripheral zone. The non-perfused area after single and double freezing continuously increased over the first 90-min period due to a successive shutdown of perfusion within the peripheral border zone. Analysis of the thermocouples' temperature at the end of freezing revealed the 0°C-front at 11.7 mm (single freeze–thaw cycle) and 12.1 mm (double freeze–thaw cycle) distant from the centre of the cryoprobe, which exactly corresponds with the initial (30 min) expansion of the area with nutritive perfusion failure. The increased non-perfused tissue area at 2 h conformed a critical border temperature between 8.29 ± 1.63°C and 9.07 ± 0.24°C. From these findings, we conclude that freezing of liver tissue to temperatures of at least < 0°C causes complete/irreversible perfusion failure, which consequently will result in cell death and tissue necrosis, and may thus be supposed as a prerequisite for the safe and successful application of cryosurgery in hepatic tumour ablation. © 2000 Cancer Research Campaig

Практикоориентированное обучение – активно реализуемая сумма знаний

МЕДИЦИНСКИЕ УЧЕБНЫЕ ЗАВЕДЕНИЯОБРАЗОВАНИЕ МЕДИЦИНСКОЕСТУДЕНТЫ МЕДИЦИНСКИХ УЧЕБНЫХ ЗАВЕДЕНИЙПРАКТИКО-ОРИЕНТИРОВАННОЕ ОБУЧЕНИЕЗНАНИЙ ПРИОБРЕТЕНИЯ СПОСОБНОСТ

Dynamics of hollow atom formation in intense x-ray pulses probed by partial covariance mapping

When exposed to ultraintense x-radiation sources such as free electron lasers (FELs) the innermost electronic shell can efficiently be emptied, creating a transient hollow atom or molecule. Understanding the femtosecond dynamics of such systems is fundamental to achieving atomic resolution in flash diffraction imaging of noncrystallized complex biological samples. We demonstrate the capacity of a correlation method called "partial covariance mapping'' to probe the electron dynamics of neon atoms exposed to intense 8 fs pulses of 1062 eV photons. A complete picture of ionization processes competing in hollow atom formation and decay is visualized with unprecedented ease and the map reveals hitherto unobserved nonlinear sequences of photoionization and Auger events. The technique is particularly well suited to the high counting rate inherent in FEL experiments

Loss, Bereavement and Creativity: Meanings and Uses

Within the field of death and bereavement studies, the assumption that loss and bereavement provide the spur to creativity has become so widespread as to assume the status of a conventional wisdom. With this in mind, this article surveys the literature on the topic, extant, and contemporary, revealing its diffuseness as well as the multidisciplinary synergies produced by those working in disparate academic and clinical fields of practice. In so doing, the article explores what it means to be creative in the context of loss and bereavement, the potential for self-development and personal growth offered by creativity and loss, the theoretical premises linking creativity and loss, and the application and challenges for creative therapies in the institutional context of hospice and palliative car

Deficits in visuo-spatial working memory, inhibition and oculomotor control in boys with ADHD and their non-affected brothers.

Few studies have assessed visuo-spatial working memory and inhibition in attention-deficit/hyperactivity disorder (ADHD) by recording saccades and consequently little additional knowledge has been gathered on oculomotor functioning in ADHD. Moreover, this is the first study to report the performance of non-affected siblings of children with ADHD, which may shed light on the familiality of deficits. A total of 14 boys with ADHD, 18 non-affected brothers, and 15 control boys aged 7-14 years, were administered a memory-guided saccade task with delays of three and seven seconds. Familial deficits were found in accuracy of visuo-spatial working memory, percentage of anticipatory saccades, and tendency to overshoot saccades relative to controls. These findings suggest memory-guided saccade deficits may relate to a familial predisposition for ADHD