CO2 conversion to phenyl isocyanates by uranium(vi) bis(imido) complexes.

Uranium(vi) trans-bis(imido) complexes [U(κ4-{(tBu2ArO)2Me2-cyclam})(NPh)(NPhR)] react with CO2 to eliminate phenyl isocyanates and afford uranium(vi) trans-[O[double bond, length as m-dash]U[double bond, length as m-dash]NR]2+ complexes, including [U(κ4-{(tBu2ArO)2Me2-cyclam})(NPh)(O)] that was crystallographically characterized. DFT studies indicate that the reaction proceeds by endergonic formation of a cycloaddition intermediate; the secondary reaction to form a dioxo uranyl complex is both thermodynamically and kinetically hindered

Glass in Cultural Heritage – An Introduction

Proceedings of the Chemistry and Conservation ScienceA brief description of different types of silicate glasses is made and the origin of colour in glasses is discussed. The principles of corrosion in glass, illustrated with a few examples, will be explained. Applications of several techniques in the chemical characterization of glasses will be shown, namely X-ray Fluorescence Spectrometry (XRF), Scanning Electron Microscopy (SEM), Optical Absorption Spectroscopy and Laser Ablation Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (LA-FTICR/MS), and Particle Induced X-ray Emission (PIXE)

On the Upper Limits of Oxidation States in Chemistry.

The concept of oxidation state (OS) is based on the concept of Lewis electron pairs, in which the bonding electrons are assigned to the more electronegative element. This approach is useful for keeping track of the electrons, predicting chemical trends, and guiding syntheses. Experimental and quantum-chemical results reveal a limit near +8 for the highest OS in stable neutral chemical substances under ambient conditions. OS=+9 was observed for the isolated [IrO4 ]+ cation in vacuum. The prediction of OS=+10 for isolated [PtO4 ]2+ cations is confirmed computationally for low temperatures only, but hasn't yet been experimentally verified. For high OS species, oxidation of the ligands, for example, of O-2 with formation of . O-1 and O-O bonds, and partial reduction of the metal center may be favorable, possibly leading to non-Lewis type structures

Surgery information reduces anxiety in the pre-operative period

PURPOSE: Patients preparing to undergo surgery should not suffer needless anxiety. This study aimed to evaluate anxiety levels on the day before surgery as related to the information known by the patient regarding the diagnosis, surgical procedure, or anesthesia. METHOD: Patients reported their knowledge of diagnosis, surgery, and anesthesia. The Spielberger State-Trait Anxiety Inventory (STAI) was used to measure patient anxiety levels. RESULTS: One hundred and forty-nine patients were selected, and 82 females and 38 males were interviewed. Twenty-nine patients were excluded due to illiteracy. The state-anxiety levels were alike for males and females (36.10 ± 11.94 vs. 37.61 ± 8.76) (mean ± SD). Trait-anxiety levels were higher for women (42.55 ± 10.39 vs. 38.08 ± 12.25, P = 0.041). Patient education level did not influence the state-anxiety level but was inversely related to the trait-anxiety level. Knowledge of the diagnosis was clear for 91.7% of patients, of the surgery for 75.0%, and of anesthesia for 37.5%. Unfamiliarity with the surgical procedure raised state-anxiety levels (P = 0.021). A lower state-anxiety level was found among patients who did not know the diagnosis but knew about the surgery (P = 0.038). CONCLUSIONS: Increased knowledge of patients regarding the surgery they are about to undergo may reduce their state-anxiety levels.PROPÓSITO: Pacientes que vão ser operados não devem sofrer ansiedade. Este estudo tem por objetivo comparar o grau de ansiedade no dia anterior à cirurgia entre pacientes que têm informação sobre seu diagnóstico, cirurgia e anestesia. MÉTODOS: Pacientes referiram seu conhecimento sobre o diagnóstico, a cirurgia e a anestesia. O inventário de Spielberger, State-Trait Anxiety Inventory (STAI), mediu a ansiedade. RESULTADOS: Cento e quarenta e nove pacientes foram selecionados, 82 mulheres e 38 homens foram entrevistados. Vinte e nove pacientes foram excluídos do estudo por analfabetismo. A ansiedade-estado foi semelhante para homens e mulheres, (36,10 ± 11,94 vs. 37,61 ± 8,76) (mean ± SD). A ansiedade-traço foi maior entre mulheres (42,55 ± 10,39 vs. 38,08 ± 12,25, P = 0,041). O nível de educação não influenciou a ansiedade-estado mas mostrou-se inversamente relacionado à ansiedade-traço. O diagnóstico fora claro para 91,7% dos pacientes entrevistados, cirurgia para 75% e anestesia para 37,5%. O desconhecimento da cirurgia elevou a ansiedade-estado (P = 0,021) cujo menor índice foi encontrado entre pacientes que não conheciam seu diagnóstico, mas sabiam sobre a cirurgia (P = 0,038). CONCLUSÕES: O conhecimento sobre a cirurgia a ser realizada pode reduzir o estado de ansiedade

ORIGINAL RESEARCH SURGERY INFORMATION REDUCES ANXIETY IN THE PRE-OPERATIVE PERIOD

PURPOSE: Patients preparing to undergo surgery should not suffer needless anxiety. This study aimed to evaluate anxiety levels on the day before surgery as related to the information known by the patient regarding the diagnosis, surgical procedure, or anesthesia. METHOD: Patients reported their knowledge of diagnosis, surgery, and anesthesia. The Spielberger State-Trait Anxiety Inventory (STAI) was used to measure patient anxiety levels. RESULTS: One hundred and forty-nine patients were selected, and 82 females and 38 males were interviewed. Twentynine patients were excluded due to illiteracy. The state-anxiety levels were alike for males and females (36.10 ± 11.94 vs. 37.61 ± 8.76) (mean ± SD). Trait-anxiety levels were higher for women (42.55 ± 10.39 vs. 38.08 ± 12.25, P = 0.041). Patient education level did not influence the state-anxiety level but was inversely related to the trait-anxiety level. Knowledge of the diagnosis was clear for 91.7% of patients, of the surgery for 75.0%, and of anesthesia for 37.5%. Unfamiliarity with the surgical procedure raised state-anxiety levels (P = 0.021). A lower state-anxiety level was found among patients who did not know the diagnosis but knew about the surgery (P = 0.038). CONCLUSIONS: Increased knowledge of patients regarding the surgery they are about to undergo may reduce their state-anxiety levels

Uranyl Analogue Complexes—Current Progress and Synthetic Challenges

Uranyl ions, {UO2}n+ (n = 1, 2), display trans, strongly covalent, and chemically robust U-O multiple bonds, where 6d, 5f, and 6p orbitals play important roles. The synthesis of isoelectronic analogues of uranyl has been of interest for quite some time, mainly with the purpose of unveiling covalence and 5f-orbital participation in bonding. Significant advances have occurred in the last two decades, initially marked by the synthesis of uranium(VI) bis(imido) complexes, the first analogues with a {RNUNR}2+ core, later followed by the synthesis of unique trans-{EUO}2+ (E = S, Se) complexes, and recently highlighted by the synthesis of the first complexes featuring a linear {NUN} moiety. This review covers the synthesis, structure, bonding, and reactivity of uranium complexes containing a linear {EUE}n+ core (n = 0, 1, 2), isoelectronic to uranyl ions, {OUO}n+ (n = 1, 2), incorporating σ- and π-donating ligands that can engage in uranium–ligand multiple bonding, where oxygen may be replaced by heavier chalcogenido, imido, nitride, and carbene ligands, or by a transition metal. It focuses on synthetic methods of well-defined molecular uranium species in the condensed phase but also references gas-phase and low-temperature-matrix experiments, as well as computational studies that may lead to valuable insights

A brief review of mass spectrometry in cultural heritage

Proceedings of the Chemistry and Conservation ScienceIn the last decade the great development of mass spectrometry techniques made them ideal tools for the characterization of many materials containing either inorganic or organic compounds. Pigments in paints, main constituents of glass and ceramic objects, enamels and glazes can be characterized by inorganic mass spectrometry. Temperas, varnishes and adhesives can be studied by organic mass spectrometry; compounds as glycerides, proteins and sugars can also be easily analysed. Due to the diversity of mass spectrometry techniques almost any compound has a special method that can be used to characterize it. A brief introduction to mass spectrometry will be given, in particular a reference to the ion generation methods and their application to the different types of samples that a conservator can have in his/her hands when studying an artwork. A few applications in cultural heritage will be given