Zirconium stable isotope analysis of zircon by MC-ICP-MS: Methods and application to evaluating intra-crystalline zonation in a zircon megacryst

Zirconium (Zr) plays a key role in the development of phases like zircon (ZrSiO₄) and baddeleyite (ZrO₂) in magmatic systems. These minerals are crucial for the study of geologic time and crustal evolution, and their high resistivity to weathering and erosion results in their preservation on timescales of billions of years. Although zircon and baddeleyite may also preserve a robust record of Zr isotope behavior in high-temperature terrestrial environments, little is known about the factors that control Zr isotope partitioning in magmatic systems, the petrogenetic significance of fractionated compositions, or how these variations are recorded in Zr-rich accessory phases. Here, we describe a new analytical protocol for accurately determining the Zr stable isotope composition of zircon by multicollector-inductively coupled plasma-mass spectrometry (MC-ICP-MS), using the double-spike method to correct for procedural and instrumental mass bias. We apply this technique to test whether zircon crystallization in carbonatite magmatic systems is a driver of Zr isotope fractionation by interrogating the internal zonation of a zircon megacryst from the Mud Tank carbonatite (MTUR1). We find the MTUR1 megacryst to lack internal zoning within analytical uncertainties with a mean μ⁹⁴/⁹⁰Zr_(NIST) = −55 ± 28 ppm (2 SD, n = 151), which suggests that zircon crystallization is not a driver of Zr isotope fractionation in carbonatite magmas. This observation is in stark contrast with those made in silicate magmatic systems, raising the possibility that the bonding environment of Zr⁴⁺ ions may be fundamentally different in carbonatite vs. silicate melts. Because of its remarkable homogeneity, the MTUR1 megacryst is an ideal natural reference material for Zr isotopic analysis of zircon using both solution and spatially resolved methods. The reproducibility of a pure Zr solution and our chemically purified zircon fractions indicate that the external reproducibility of our method is on the order of ±28 ppm for μ⁹⁴/⁹⁰Zr, or ±7 ppm per amu, at 95% confidence

Clinical Knowledge Graph Embedding Representation Bridging the Gap between Electronic Health Records and Prediction Models

Learning knowledge embedding representation is an increasingly important technology. However, the choice of hyperparameters is seldom justified and usually relies on exhaustive search. Understanding the effect of hyperparameter combinations on embedding quality is crucial to avoid the inefficient process and enhance practicality of embedding representation along subsequent machine learning applications. This work focuses on translational embedding models for multi-relational categorized data in the clinical domain. We trained and evaluated models with different combinations of hyperparameters on two clinical datasets. We contrasted the results by comparing metric distributions and fitting a random forest regression model. Classifiers were trained to assess embedding representation quality. Finally, clustering was tested as a validation protocol. We observed consistent patterns of hyperparameter preference and identified those that achieved better results respectively. However, results show different patterns regarding link prediction, which is taken as strong evidence that traditional evaluation protocol used for open-domain data does not necessarily lead to the best embedding representation for categorized data

Perioperative Bluttransfusion: Nutzen, Risiken und Richtlinien

Zusammenfassung: Chirurgisch und traumatisch bedingte Blutverluste sind die häufigsten Ursachen von allogenen Bluttransfusionen, welche nach wie vor mit beträchtlichen Risiken verbunden sind. Nach Korrektur der Hypovolämie ist der Anästhesist häufig mit einer normovolämischen Anämie konfrontiert. Die klinische Relevanz dieses isolierten Hämoglobinabfalls besteht darin, dass die globale und/oder regionale Sauerstoffversorgung über eine kritische Schwelle hinaus beeinträchtigt sein kann, wonach sich eine Gewebshypoxie einstellt. Diese kritische Schwelle ist von Patient zu Patient verschieden und abhängig von dessen Kapazität, den Abfall des Sauerstoffgehaltes zu kompensieren. Aus diesem Grunde sollten primär physiologische Transfusionskriterien angewandt werden und nicht rigide nummerische Transfusionskriterien wie die Hämoglobinkonzentration, welche die individuelle Reserve eines Patienten weitgehend außer Acht lasse

Enantioselective and Regiodivergent Copper-Catalyzed Electrophilic Arylation of Allylic Amides with Diaryliodonium Salts.

A catalytic enantioselective and regiodivergent arylation of alkenes is described. Chiral copper(II)bisoxazoline complexes catalyze the addition of diaryliodonium salts to allylic amides in excellent ee. Moreover, the arylation can be controlled by the electronic nature of the diaryliodonium salt enabling the preparation of nonracemic diaryloxazines or β,β'-diaryl enamides.We are grateful to EPSRC, GSK and the University of Cambridge (E.C., H.P.J.M. & M.T.) and the ERC and EPSRC for fellowships (M.J.G.). Mass spectrometry data were acquired at the EPSRC UK National Mass Spectrometry Facility at Swansea University.This is the final version of the article. It first appeared from ACS via http://dx.doi.org/10.1021/jacs.5b0393

Total hip arthroplasty through the direct anterior approach with and without the use of a traction table: a matched-control, retrospective, single-surgeon study.

Hip surgeons performing total hip arthroplasty (THA) through the direct anterior approach (DAA) commonly use a traction table to facilitate exposure. Even though performing THA through DAA without a traction table could be technically more demanding, this technique offers the advantage of intraoperative leg length comparison. Therefore, this study aimed to compare clinical outcomes, complication rates, component positioning, and leg length discrepancy (LLD) after THA through the DAA performed with or without a traction table. A single-surgeon continuous series of 75 patients who underwent DAA THA performed with a traction table was matched for gender, age, and BMI with 75 patients who underwent DAA THA performed without a traction table (male, 62; female, 88, with an average age of 68 years old). Clinical and radiological outcomes, intra- and postoperative complications, and LLD were retrospectively assessed. No statistically significant difference was detected in surgical time, hospital stay, Harris Hip Score (HHS), complication rates, and implant positioning between the two groups. Leg length restoration was significantly more accurate in the group performed without a traction table (2.4 ± 2 mm vs. 3.7 ± 3.1 mm; p value ≤ 0.05). No LLD > 10 mm was reported in the group performed without a traction table, whereas two cases (2.7%) were reported in those performed with a traction table. Performing THA through DAA without a traction table was associated with a significantly more accurate leg length restoration without a significant increase in the rates of intra- and postoperative complications

Introduction philosophique a l'étude du droit pénal et de la reforme pénitentiaire / par J. Tissot

FA109XIV, 584 p

Influence of Bacille Calmette-Guérin Vaccination on Size of Tuberculin Skin Test Reaction: To What Size?

Background. Previous bacillus Calmette-Guérin (BCG) vaccination can confound the results of a tuberculin skin test (TST). We sought to determine a cutoff diameter of TST induration beyond which the influence of BCG vaccination was negligible in evaluating potential Mycobacterium tuberculosis infection in a population of health care workers with a high vaccination rate and low incidence of tuberculosis. Methods. From 1991 through 1998, all new employees at the University Hospital of Lausanne, Switzerland, underwent a 2-step TST at entry visit. We also gathered information on demographic characteristics, along with factors commonly associated with tuberculin positivity, including previous BCG vaccination, history of latent M. tuberculosis infection, and predictors for M. tuberculosis infection. Results. Among the 5117 investigated subjects, we found that influence of BCG vaccination on TST results varied across categories of age (likelihood ratio test, 0.0001). Prior BCG vaccination had a strong influence on skin test results of ⩽18 mm in diameter among persons <40 years old, compared with the influence of factors predictive of M. tuberculosis infection. Prior latent M. tuberculosis infection and travel or employment in a country in which tuberculosis is endemic also had significant influences. Conclusions. Interpretation of TST reactions of ⩽18 mm among BCG-vaccinated persons <40 years of age must be done with caution in areas with a low incidence of tuberculosis. In such a population, except for persons who have never been vaccinated, TST reactions of ⩽18 mm are more likely to be the result of prior vaccination than infection and should not systematically lead to preventive treatmen

The REE isotopic compositions of the Earth

Lanthanides are a group of 14 naturally occurring elements with atomic numbers ranging from 57 (La) to 74 (Lu), which are also known as rare earth elements (REE). REEs are ubiquitous in minerals and rocks. The chemical properties of REEs vary as smooth functions of their atomic numbers, a phenomenon known as the contraction of the lanthanides. This is the main control behind REE fractionation in minerals and rocks. The relative abundance of REEs is usually presented as the REE pattern by normalizing the concentrations in the sample to those in reference materials such as chondrites and shales