Partial densities of states from x-ray absorption and Auger electron spectroscopy: Use of core-hole memory.

Ag L 3 edge x-ray absorption and L 3 - M 4,5 M 4,5 Auger electron spectra have been measured and simulated for a variety of x-ray electric-field polarization and Auger electron emission directions. The theory relies on density-functional theory, use of the Bethe-Salpeter equation, atomic multiplet theory, and a simplified model for the Auger line shape and its dependence on photon energy. We also demonstrate that partial densities of states for d T 2g , d Eg , and s Ag symmetry partial-wave channels at the Ag site in the solid can be deduced from the experimental measurements with only atomic theoretical input, i.e., with no solid-state theory other than assuming a Fermi edge.

Charge-transfer satellites and chemical bonding in photoemission and x-ray absorption of SrTiO3 and rutile TiO2: Experiment and first-principles theory with general application to spectroscopic analysis.

First-principles, real-time-cumulant, and Bethe-Salpeter-equation calculations fully capture the detailed satellite structure that occurs in response to the sudden creation of the core hole in both photoemission and x-ray absorption spectra of the transition-metal compounds SrTiO3 and rutile TiO2. Analysis of the excited-state, real-space charge-density fluctuations betrays the physical nature of these many electron excitations that are shown to reflect the materials' solid-state electronic structure and chemical bonding. This first-principles development of the cumulant-based core hole spectral function is generally applicable to other systems and should become a standard tool for all similar spectroscopic analysis going beyond the quasiparticle physics of the photoelectric effect.

Core hole processes in x-ray absorption and photoemission by resonant Auger-electron spectroscopy and first-principles theory.

Electron-core hole interactions are critical for proper interpretation of core-level spectroscopies commonly used as analytical tools in materials science. Here we utilize resonant Auger-electron spectroscopy to uniquely identify exciton, shake, and charge-transfer processes that result from the sudden creation of the core hole in both x-ray-absorption and photoemission spectra. These effects are captured for the transition-metal compounds SrTiO3 and MoS2 by fully ab initio, combined real-time cumulant, and Bethe-Salpeter equation approaches to account for core hole dynamics and screening. Atomic charges and excited-state electron-density fluctuations reflect materials' solid-state electronic structure, loss of translational symmetry around the core hole, and breakdown of the sudden approximation. They also demonstrate competition between long- and short-range screening in a solid.

W + W - H production at lepton colliders: a new hope for heavy neutral leptons.

We present the first study of the production of a Standard Model Higgs boson at a lepton collider in association with a pair of W bosons, e + e - → W + W - H , in the inverse seesaw model. Taking into account all relevant experimental and theoretical constraints, we find sizable effects due to the additional heavy neutrinos up to - 38 % on the total cross-section at a center-of-mass energy of 3 TeV, and even up to - 66 % with suitable cuts. This motivates a detailed sensitivity analysis of the process e + e - → W + W - H as it could provide a new, very competitive experimental probe of low-scale neutrino mass models.

Strain and Bond Length Dynamics upon Growth and Transfer of Graphene by NEXAFS Spectroscopy from First-Principles and Experiment.

As the quest toward novel materials proceeds, improved characterization technologies are needed. In particular, the atomic thickness in graphene and other 2D materials renders some conventional technologies obsolete. Characterization technologies at wafer level are needed with enough sensitivity to detect strain in order to inform fabrication. In this work, NEXAFS spectroscopy was combined with simulations to predict lattice parameters of graphene grown on copper and further transferred to a variety of substrates. The strains associated with the predicted lattice parameters are in agreement with experimental findings. The approach presented here holds promise to effectively measure strain in graphene and other 2D systems at wafer levels to inform manufacturing environments.

Energy level alignment at organic semiconductor/metal interfaces: effect of polar self-assembled monolayers at the interface.

We determined the shifts in the energy levels of approximately 15 nm thick poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] films deposited on various substrates including self-assembled monolayer (SAM) modified Au surfaces using photoelectron spectroscopy. As the unmodified substrates included Au, indium tin oxide, Si (with native oxide), and Al (with native oxide), a systematic shift in the detected energy levels of the organic semiconductor was observed to follow the work function values of the substrates. Furthermore, we used polar SAMs to alter the work function of the Au substrates. This suggests the opportunity to control the energy level positions of the organic semiconductor with respect to the electrode Fermi level. Photoelectron spectroscopy results showed that, by introducing SAMs on the Au surface, we successfully increased and decreased the effective work function of Au surface. We found that in this case, the change in the effective work function of the metal surface was not reflected as a shift in the energy levels of the organic semiconductor, as opposed to the results achieved with different substrate materials. Our study showed that when a substrate is modified by SAMs (or similarly by any adsorbed molecules), a new effective work function value is achieved; however, it does not necessarily imply that the new modified surface will behave similar to a different metal where the work function is equal to the effective work function of the modified surface. Various models and their possible contribution to this result are discussed.

Neuroendocrinological effects of acupuncture treatment in patients with irritable bowel syndrome.

OBJECTIVES: Quality of life (QoL) improvement in patients with irritable bowel syndrome (IBS) during acupuncture (AC) treatment seems to be due to a placebo effect. The aim was to explore if acupuncture has some specific influence on the neuroendocrinic and autonomic nervous system (ANS). DESIGN/SETTING: Patients with IBS were randomly assigned to receive either acupuncture (AC) or sham acupuncture (SAC) using the so-called "Streitberger needle". QoL was measured with the functional quality of life diseases quality of life questionnaire (FDDQL) and SF-36. The effect on ANS was evaluated by measuring salivary cortisol and by cardiovascular responses on a tilt table before and after 10 AC treatments. Complete data sets of tilt table and salivary morning cortisol were available for 9 patients in the AC and 12 in SAC group. RESULTS: QoL increased in both groups (p=0.001) with no group differences. Salivary cortisol decreased in all groups (F=10.55; p=0.006). However, the decrease was more pronounced in the AC group (F=4.07; p=0.033) (ANOVA repeated measures model). Heart rate response decreased during orthostatic stress in the AC group while it increased in the SAC group (F=9.234; p=0.005), indicating an increased parasympathetic tone in the AC group. Improvement of pain was positively associated with increased parasympathetic tone in the AC group (F=10.1; p=0.006), but not in the SAC group. CONCLUSIONS: The acupuncture specific physiological effects are in contrast to the unspecific improvement of QoL in both AC and SAC groups. Thus, different mechanisms seem to be involved in placebo and real-acupuncture driven improvements. The specific mechanism of action of acupuncture on the ANS remains unclear and deserves further evaluation.

Characterization of primary rat proximal tubular cells by gene expression analysis.

The kidney plays a major role in excretory and reabsorptive processes. The kidney cortex consists primarily of proximal tubular cells, which are epithelial cells that are often involved in the induction and progression of various kidney diseases. Therefore primary proximal tubular cells are widely used as a renal cell model. To further characterize this kidney in vitro model different time points in culture after isolation of the cells were compared to the cortex in vivo using gene expression analysis based on microarrays. This study revealed that many metabolic pathways and some kidney-specific functions are lacking in the in vitro model. Furthermore genes involved in RNA and protein synthesis, intracellular transport, extracellular matrix and cytoskeletal organization were upregulated in culture compared to in vivo, indicating proliferation of the cells and differentiation into a cell culture phenotype. The data represented here may help to evaluate the in vivo relevance of results obtained with this in vitro model.

Acupuncture treatment in irritable bowel syndrome.

BACKGROUND AND AIMS: Despite occasional positive reports on the efficacy of acupuncture (AC) on functions of the gastrointestinal tract, there is no conclusive evidence that AC is effective in the treatment of irritable bowel syndrome (IBS). PATIENTS AND METHODS: Forty three patients with IBS according to the Rome II criteria were randomly assigned to receive either AC (n = 22) or sham acupuncture (SAC) (n = 21) using the so-called "Streitberger needle". Treatment duration was 10 sessions with an average of two AC sessions per week. The primary end point was improvement in quality of life (QOL) using the functional digestive diseases quality of life questionnaire (FDDQL) and a general quality of life questionnaire (SF-36), compared with baseline assessments. QOL measurements were repeated three months after treatment. RESULTS: Both the AC and SAC groups improved significantly in global QOL, as assessed by the FDDQL, at the end of treatment (p = 0.022), with no differences between the groups. SF-36 was insensitive to these changes (except for pain). This effect was partially reversed three months later. Post hoc comparison of responders and non-responders in both groups combined revealed a significant prediction of the placebo response by two subscales of the FDDQL (sleep, coping) (F = 6.746, p = 0.003) in a stepwise regression model. CONCLUSIONS: Acupuncture in IBS is primarily a placebo response. Based on the small differences found between the AC and SAC groups, a study including 566 patients would be necessary to prove the efficacy of AC over SAC. The placebo response may be predicted by high coping capacity and low sleep quality in individual patients.

Hemoglobinopathy York [beta146 (HC3) His==>Pro]: first report of a family history.

The rare hemoglobinopathies with abnormal oxygen binding are usually characterized by erythropoietin-mediated erythrocytosis. Bare et al. first described a hemoglobinopathy with mild erythrocytosis in a 22-year-old Caucasian woman in 1976. These authors called the abnormal hemoglobin Hb York. Hb York is characterized by a mutation at the beta146 position that changes histidine into proline. A second case of Hb York was observed by Kosugi et al. in 1983. To the best of our knowledge, no further cases have been reported. We have encountered a new case of Hb York, which was detected by agar gel electrophoresis at pH 6.0. Analysis of DNA sequences revealed a CAC-->CCC mutation in codon 146. The proportion of Hb York was approximately 50%. Analysis of oxygen transport function showed a leftward shift of the sigmoidal O2-dissociation curve. P50 was reduced to 15.5 mmHg. Investigation of family members revealed Hb York in the patient's sister, two daughters and a grandson. In retrospect, the mother of the patient may also have been affected. The mode of inheritance is autosomal dominant.

Duplex-guided compression of iatrogenic femoral pseudoaneurysms.

BACKGROUND: Iatrogenic pseudoaneurysms are a major complication following percutaneous cannulations of the femoral artery. Surgical repair has been the traditional treatment modality. Recent reports have introduced duplex-guided compression as a means of nonoperative management of these injuries. We proposed to determine if duplex-guided compression of femoral pseudoaneurysms could be successfully performed, could be done without complication, and could maintain thrombosis on long-term follow-up. STUDY DESIGN: All patients presenting with large groin hematomas following invasive percutaneous femoral artery procedures over a seven-month period were studied using color-flow duplex analysis. Six pseudoaneurysms were discovered and successfully treated with duplex-guided compression. All patients were then followed-up prospectively with both early and long-term repeat duplex analysis. RESULTS: All patients were rescanned 72 hours later and the pseudoaneurysms remained thrombosed. Upon returning for long-term follow-up examination, patients again had duplex confirmation of thrombosis, with a mean follow-up time of 21 months (range, five to 29 months). No complications attributable to this technique have been noted. CONCLUSIONS: This study confirms the clinical usefulness of duplex-guided compression in the evaluation and treatment of iatrogenic femoral pseudoaneurysms.

Continuous measurement of oxygen uptake. Evaluation of the Engström metabolic computer and clinical experiences.

A new system for continuous measurement of oxygen uptake was tested. The tidal volumes delivered by the system, the accuracy of the oxygen sensor cell, measurement of the oxygen uptake at different inspired oxygen concentrations, and comparative tests of oxygen uptake using the Fick principle were studied. Judging from our results, even thorough maintenance could not entirely prevent leakages. Due to a construction error, there was a large increase in measured oxygen uptake if inspired oxygen concentration was increased. While carbon-dioxide output was constant, this led to respiratory quotients of less than 0.5. By modifying the system with a mixing chamber for the inspiratory gas, new tubing to the oxygen sensor cell and changes in the computer software, these errors have been corrected in the meantime. In comparative tests of oxygen uptake using the Fick principle (cardiac output and arteriovenous oxygen content difference), we found a mean difference between EMC and the Fick principle of about 6.6% (P less than or equal to 0.001, r = 0.91) with nearly identical standard deviations for both values. Our experience indicates that the EMC is suitable for continuous measurements of oxygen uptake. Additional technical improvements seem to be possible.