Intensity Ratio of Kß/Kα in Selected Elements from Mg to Cu, and the Chemical Effects of Cr Kα1,2 Diagram Lines and Cr Kß/Kα Intensity Ratio in Cr Compounds.

Kα,ß X-ray lines from photon excitation were measured in selected elements from Mg to Cu using a high-resolution double-crystal X-ray spectrometer with a proportional counter, and the Kß/Kα intensity ratio for each element was obtained, after correcting for self-absorption, detection efficiency, and crystal reflectance. This intensity ratio increases rapidly from Mg to Ca but, in the 3d elements region, the increase becomes slower. This is related to the intensity of the Kß line involving valence electrons. The slow increase of this ratio in the 3d elements region is thought to be due to the correlation between 3d and 4s electrons. Moreover, the chemical shifts, FWHM, asymmetry indices, and Kß/Kα intensity ratios of the Cr compounds, due to different valences, were also investigated using the same double-crystal X-ray spectrometer. The chemical effects were clearly observed, and the Kß/Kα intensity ratio was found to be compound-dependent for Cr.

Limits of pre-endoscopic scoring systems in geriatric patients with upper gastrointestinal bleeding.

Upper gastrointestinal bleeding (UGIB) is a common cause of hospital admission worldwide and several risk scores have been developed to predict clinically relevant outcomes. Despite the geriatric population being a high-risk group, age is often overlooked in the assessment of many risk scores. In this study we aimed to compare the predictive accuracy of six pre-endoscopic risk scoring systems in a geriatric population hospitalised with UGIB. We conducted a multi-center cross-sectional study and recruited 136 patients, 67 of these were 65-81.9 years old ("< 82 years"), 69 were 82-100 years old ("≥ 82 years"). We performed six pre-endoscopic risk scores very commonly used in clinical practice (i.e. Glasgow-Blatchford Bleeding and its modified version, T-score, MAP(ASH), Canada-United Kingdom-Adelaide, AIMS65) in both age cohorts and compared their accuracy in relevant outcomes predictions: 30-days mortality since hospitalization, a composite outcome (need of red blood transfusions, endoscopic treatment, rebleeding) and length of hospital stay. T-score showed a significantly worse performance in mortality prediction in the "≥ 82 years" group (AUROC 0.53, 95% CI 0.27-0.75) compared to "< 82 years" group (AUROC 0.88, 95% CI 0.77-0.99). In the composite outcome prediction, except for T-score, younger participants had higher sensitivities than those in the "≥ 82 years" group. All risk scores showed low performances in the prediction of length of stay (AUROCs ≤ 0.70), and, except for CANUKA score, there was a significant difference in terms of accuracy among age cohorts. Most used UGIB risk scores have a low accuracy in the prediction of clinically relevant outcomes in the geriatric population; hence novel scores should account for age or advanced age in their assessment.