54 research outputs found

    Observation of electron transfer mediated decay in aqueous solution

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    Photoionization is at the heart of X ray photoelectron spectroscopy XPS , which gives access to important information on a sample s local chemical environment. Local and non local electronic decay after photoionization in which the refilling of core holes results in electron emission from either the initially ionized species or a neighbour, respectively have been well studied. However, electron transfer mediated decay ETMD , which involves the refilling of a core hole by an electron from a neighbouring species, has not yet been observed in condensed phase. Here we report the experimental observation of ETMD in an aqueous LiCl solution by detecting characteristic secondary low energy electrons using liquid microjet soft XPS. Experimental results are interpreted using molecular dynamics and high level ab initio calculations. We show that both solvent molecules and counterions participate in the ETMD processes, and different ion associations have distinctive spectral fingerprints. Furthermore, ETMD spectra are sensitive to coordination numbers, ion solvent distances and solvent arrangemen

    Premorbid body weight predicts weight loss in both anorexia nervosa and atypical anorexia nervosa: Further support for a single underlying disorder.

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    OBJECTIVE For adolescents, DSM-5 differentiates anorexia nervosa (AN) and atypical AN with the 5th BMI-centile-for-age. We hypothesized that the diagnostic weight cut-off yields (i) lower weight loss in atypical AN and (ii) discrepant premorbid BMI distributions between the two disorders. Prior studies demonstrate that premorbid BMI predicts admission BMI and weight loss in patients with AN. We explore these relationships in atypical AN. METHOD Based on admission BMI-centile < or ≥5th, participants included 411 female adolescent inpatients with AN and 49 with atypical AN from our registry study. Regression analysis and t-tests statistically addressed our hypotheses and exploratory correlation analyses compared interrelationships between weight loss, admission BMI, and premorbid BMI in both disorders. RESULTS Weight loss in atypical AN was 5.6 kg lower than in AN upon adjustment for admission age, admission height, premorbid weight and duration of illness. Premorbid BMI-standard deviation scores differed by almost one between both disorders. Premorbid BMI and weight loss were strongly correlated in both AN and atypical AN. DISCUSSION Whereas the weight cut-off induces discrepancies in premorbid weight and adjusted weight loss, AN and atypical AN overall share strong weight-specific interrelationships that merit etiological consideration. Epidemiological and genetic associations between AN and low body weight may reflect a skewed premorbid BMI distribution. In combination with prior findings for similar psychological and medical characteristics in AN and atypical AN, our findings support a homogenous illness conceptualization. We propose that diagnostic subcategorization based on premorbid BMI, rather than admission BMI, may improve clinical validity. PUBLIC SIGNIFICANCE Because body weights of patients with AN must drop below the 5th BMI-centile per DSM-5, they will inherently require greater weight loss than their counterparts with atypical AN of the same sex, age, height and premorbid weight. Indeed, patients with atypical AN had a 5.6 kg lower weight loss after controlling for these variables. In comparison to the reference population, we found a lower and higher mean premorbid weight in patients with AN and atypical AN, respectively. Considering previous psychological and medical comparisons showing little differences between AN and atypical AN, we view a single disorder as the most parsimonious explanation. Etiological models need to particularly account for the strong relationship between weight loss and premorbid body weight

    Structurally defined zincated and aluminated complexes of ferrocene made by alkali-metal-synergistic syntheses

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    Reaction of ferrocene with 1 or 2 molar equiv of the synergistic-operative bimetallic sodium zincate base TMEDA·Na(μ-TMP)(μ-tBu)Zn(tBu) yields mainly mono- or dizincated complexes TMEDA·Na(μ-TMP)[μ-(C5H4)Fe(C5H5)]ZntBu (1) and [TMEDA·Na(μ-TMP)Zn(tBu)]2(C5H4)2Fe (2). Likewise, the separated pairing of Li(TMP) and (TMP)AliBu2 in the presence of THF can mono- or dimetalate ferrocene in a synergistic two-step lithiation/trans-metal-trapping protocol to give THF·Li(μ-TMP)[μ-(C5H4)Fe(C5H5)]Al(iBu)2 (4) or [THF·Li(μ-TMP)Al(iBu)2]2(C5H4)2Fe (5). In the absence of Lewis donating cosolvents, a 4-fold excess of the sodium zincate appears to produce an unprecedented 4-fold zincated ferrocene of formula Na4(TMP)4Zn4(tBu)4[(C5H3)2Fe] (3), whereas when donor solvent is withheld from the lithium/aluminum pairing, only dimetalation of ferrocene is possible. Tetrametalation seems to be inhibited by the in situ generation of TMP(H) via amido basicity, which then acts as a Lewis donor toward lithium, preventing inverse-crown formation and preferentially forming the Lewis acid–Lewis base adduct [TMP(H)·Li(μ-TMP)Al(iBu)2]2(C5H4)2Fe (6). With the exception of 3, all aforementioned complexes have been characterized by X-ray crystallography, while 1–6 have also been studied by solution NMR spectroscopic studies

    Search for new physics in dijet angular distributions using proton-proton collisions at root s=13 TeV and constraints on dark matter and other models

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    An Erratum to this article was published on 29 April 2022: https://doi.org/10.1140/epjc/s10052-022-10278-0search is presented for physics beyond the standard model, based on measurements of dijet angular distributions in proton-proton collisions at root s = 13 TeV. The data collected with the CMS detector at the LHC correspond to an integrated luminosity of 35.9 fb(-1). The observed distributions, corrected to particle level, are found to be in agreement with predictions from perturbative quantum chromodynamics that include electroweak corrections. Constraints are placed on models containing quark contact interactions, extra spatial dimensions, quantum black holes, or dark matter, using the detector-level distributions. In a benchmark model where only left-handed quarks participate, contact interactions are excluded at the 95% confidence level up to a scale of 12.8 or 17.5 TeV, for destructive or constructive interference, respectively. The most stringent lower limits to date are set on the ultraviolet cutoff in the Arkani-Hamed-Dimopoulos-Dvali model of extra dimensions. In the Giudice-Rattazzi-Wells convention, the cutoff scale is excluded up to 10.1 TeV. The production of quantum black holes is excluded for masses below 5.9 and 8.2 TeV, depending on the model. For the first time, lower limits between 2.0 and 4.6 TeV are set on the mass of a dark matter mediator for (axial-)vector mediators, for the universal quark coupling g(q) = 1.0.Peer reviewe

    B. Sprachwissenschaft.

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    Observation of WWW Production in pp Collisions at √s = 13 TeV with the ATLAS Detector

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    This Letter reports the observation of W W W production and a measurement of its cross section using 139     fb − 1 of proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. Events with two same-sign leptons (electrons or muons) and at least two jets, as well as events with three charged leptons, are selected. A multivariate technique is then used to discriminate between signal and background events. Events from W W W production are observed with a significance of 8.0 standard deviations, where the expectation is 5.4 standard deviations. The inclusive W W W production cross section is measured to be 820 ± 100   ( stat ) ± 80   ( syst )     fb , approximately 2.6 standard deviations from the predicted cross section of 511 ± 18     fb calculated at next-to-leading-order QCD and leading-order electroweak accuracy
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