Semiclassical theory of spectral line shapes. II. Applications to CO, HCl, and OCS, broadened by inert gases

The semiclassical theory of spectral line broadening developed in the previous paper of this series is used to calculate the half‐widths and shifts of nonoverlapping rotational spectral lines of CO, HCl, and OCS, broadened by inert gases. Comparisons are made with the available experimental data and with related theoretical analyses, and reasonable agreement is obtained. The method used applies both to fairly quantum systems as well as to the relatively classical ones. A symmetrized semiclassical expression for Wigner 6‐j symbols is given and applied

Routine characterization and interpretation of complex alkali feldspar intergrowths

Almost all alkali feldspar crystals contain a rich inventory of exsolution, twin, and domain microtextures that form subsequent to crystal growth and provide a record of the thermal history of the crystal and often of its involvement in replacement reactions, sometimes multiple. Microtextures strongly influence the subsequent behavior of feldspars at low temperatures during diagenesis and weathering. They are central to the retention or exchange of trace elements and of radiogenic and stable isotopes. This review is aimed at petrologists and geochemists who wish to use alkali feldspar microtextures to solve geological problems or who need to understand how microtextures influence a particular process. We suggest a systematic approach that employs methods available in most well founded laboratories. The crystallographic relationships of complex feldspar intergrowths were established by the 1970s, mainly using single-crystal X-ray diffraction, but such methods give limited information on the spatial relationships of the different elements of the microtexture, or of the mode and chronology of their formation, which require the use of microscopy. We suggest a combination of techniques with a range of spatial resolution and strongly recommend the use of orientated sections. Sections cut parallel to the perfect (001) and (010) cleavages are the easiest to locate and most informative. Techniques described are light microscopy; scanning electron microscopy using both backscattered and secondary electrons, including the use of surfaces etched in the laboratory; electron-probe microanalysis and analysis by energy-dispersive spectrometry in a scanning electron microscope; transmission electron microscopy. We discuss the use of cathodoluminescence as an auxiliary technique, but do not recommend electron-backscattered diffraction for feldspar work. We review recent publications that provide examples of the need for great care and attention to pre-existing work in microtextural studies, and suggest several topics for future work

Boron nanobelts grown under intensive ion bombardment

High-quality α-tetragonal crystalline boronnanobelts with [001] growth axis were synthesized using a novel method combining e-beam evaporation and plasma ion bombardment techniques. Intensive ion bombardment of the growingboronnanobelts at a high substrate temperature (∼1200°C) was found to be effective in increasing the atomic density, reducing the crystal disorder, and improving the yield of the nanobelts.This work was supported by the Australian Research Council ARC

Sudden Death from Embolism

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A comparison of A-level performance in economics and business studies: how much more difficult is economics?

This paper uses ALIS data to compare academic performance in two subjects often viewed as relatively close substitutes for one another at A-level. The important role of GCSE achievement is confirmed for both subjects. There is evidence of strong gender effects and variation in outcomes across Examination Boards. A counterfactual exercise suggests that if the sample of Business Studies candidates had studied Economics nearly 40% of those who obtained a grade C or better in the former subject would not have done so in the latter. The opposite exercise uggests that 12% more Economics candidates would have achieved a grade C or better if they had taken Business Studies. In order to render a Business Studies A-level grade comparable to an Economics one in terms of relative difficulty, we estimate that a downward adjustment of 1.5 UCAS points should be applied to the former subject. This adjustment is lower than that suggested by correction factors based on conventional subject pair analysis for these two subjects

Semiclassical theory of molecular spectral line shapes in gases

A semiclassical theory of the width and shift of molecular spectral lines is developed for gases. Overlapping and nonoverlapping lines are considered, within the framework of the impact approximation. Use is made of "exact" semiclassical theory of molecular collisions, recently developed by Miller and by Marcus, and of developments in the quantum mechanical theory of spectral line shapes, by introducing the former into the latter. Comparison is made with a classical-like approach

Lesões Cutâneas Acrais Agudas Inflamatórias Vasculares Reativas e SARS-CoV-2

Introduction: Coronavirus disease 2019 (COVID-19) predominantly affects the respiratory system, but there have been many reports of skin involvement. Several cutaneous manifestations associated with COVID-19 have been identified, including acral lesions (pernio-like), which we intend to better characterize in this study. Methods: Demographic, clinical and major histopathologic characteristics of acral skin lesions occurring during the acute infection stage of COVID-19 disease were evaluated in this survey conducted in the Dermatology Division of Santa Casa Hospital Complex, Federal University of Health Sciences, Porto Alegre, Brazil. Results: In the present study, we evaluated eight female patients with acute SARS-CoV-2 infection confirmed by PCR with acral skin lesions including pernio-like. The mean age was 43.6 and with no other acute disease, who had a good outcome with need for hospitalization only in 2 cases. Pernio-like lesions were observed under hot weather conditions in patients who denied any previous history of similar cutaneous manifestations. Some acral lesions resembled those of lupus erythematosus and of herpes simplex paronychia, but laboratory tests were negative for those conditions. Unusual nail involvement was present, characterized by half-moon shaped erythematous bands at the distal margin of the lunula. Conclusion: Recognition of these skin lesions is important in that they could be potential markers, aiding in the diagnosis and prognosis of COVID-19 disease.Introdução: A doença coronavírus 2019 (COVID-19) afeta predominantemente o sistema respiratório, porém há múltiplos relatos de comprometimento da pele. Várias manifestações cutâneas foram identificadas, incluindo as de padrão acral (tipo eritema pérnio), as quais pretendemos caracterizar melhor neste estudo. Métodos: As principais características demográficas, clínicas e histopatológicas das lesões cutâneas acrais que ocorreram na fase aguda da infecção pela COVID-19 foram avaliadas nesta pesquisa realizada no Departamento de Dermatologia do Complexo Hospitalar Santa Casa e Universidade Federal de Ciências da Saúde de Porto Alegre, Brasil. Resultados: No presente estudo, avaliamos oito casos de infecção aguda por SARS-CoV-2 confirmados por PCR, com lesões cutâneas acrais incluindo aquelas tipo eritema pernio. Eram oito mulheres, com idade média de 43,6 anos, sem outra doença aguda, que tiveram uma boa evolução clínica com necessidade de hospitalização em apenas dois casos. Foram identificadas manifestações tipo eritema pérnio, surgidas em períodos onde o clima era de temperaturas elevadas, em pacientes que negaram quadros semelhantes prévios. Houve casos de lesões acrais semelhantes a lúpus eritematoso e paroníquia herpética cuja investigação laboratorial foi negativa para tais patologias. Evidenciaram-se inusi- tados acometimentos ungueais, em forma de meia-lua, com bandas eritematosas circundando a margem distal da lúnula. Conclusão: O reconhecimento destas lesões dermatológicas é importante, pois podem se revelar potenciais marcadores e auxiliarem no diagnóstico e prognóstico da doença COVID-19

Regulated ion transport in mouse liver cyst epithelial cells

AbstractDerived from bile duct epithelia (BDE), secretion by liver cyst-lining epithelia is positioned to drive cyst expansion but the responsible ion flux pathways have not been characterized. Cyst-lining epithelia were isolated and cultured into high resistance monolayers to assess the ion secretory pathways. Electrophysiologic studies showed a marked rate of constitutive transepithelial ion transport, including Cl− secretion and Na+ absorption. Na+ absorption was amiloride-sensitive, suggesting the activation of epithelial sodium channels (ENaC). Further, both cAMPi and extracellular ATP induced robust secretory responses. Western blotting and immunohistologic analysis of liver cyst epithelia demonstrated expression of P2X4, a potent purinergic receptor in normal BDE. Luminometry and bioassaying measured physiologically relevant levels of ATP in a subset of liver cyst fluid samples. Liver cyst epithelia also displayed a significant capacity to degrade extracellular ATP. In conclusion, regulated ion transport pathways are present in liver cyst epithelia and are positioned to direct fluid secretion into the lumen of liver cysts and promote increases in liver cyst expansion and growth