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We have detected the methanol dimer, trimer, and tetramer at equilibrium conditions at room temperature in the gas phase using direct absorption Fourier transform infrared spectroscopy. The infrared intensity of the OH-stretching transitions are enhanced upon hydrogen bonding and are increasingly red-shifted with increasing cluster size, facilitating identification and quantification of the various clusters. We calculate the intensities of the bound OH-stretches, OH b , for all clusters with a range of reduced dimensional vibrational models with different levels of electronic structure theory. Partial pressures of the clusters are obtained by scaling the measured integrated absorbance of the OH b -stretching bands by the calculated intensities of the associated vibrational transitions. We estimate the methanol dimer equilibrium constant, K D , to be 0.033, at 298.15 K, which is comparable to that of the water dimer. For the methanol trimer and tetramer, we estimate equilibrium constants for aggregation of monomers of K T ∼ 0.04 and K Q ∼ 0.6, respectively.

We present a conceptually simple model for understanding the significant spectral changes that occur with the temperature in the infrared spectra of hydrogen-bound complexes. We have measured room-temperature spectra of the methanol dimer and two deuterated isotopologues in the OH(D)-stretching region. We correctly predict spectral changes observed in the gas phase for the bound OH stretch in the methanol dimer from jet-cooled to room temperature and corroborate this with experimental and theoretical results for deuterated isotopologues. The origin of the observed spectral features is explained based on a reduced-dimensional vibrational model, which includes the two high-frequency OH stretches, the two methyl torsions, and the six intermolecular low-frequency vibrations. Key to the success of the model is a new coordinate definition to describe the intrinsic large-amplitude curvilinear motion of low-frequency vibrations. Despite the deceivingly simple appearance of the room temperature bound OH-stretching fundamental band, it consists of ∼10 7 vibrational transitions.

We have detected the tert -butyl hydroperoxide dimer, ( t -BuOOH) 2 , in the gas phase at room temperature using conventional FTIR techniques. The dimer is identified by an asymmetric absorbance band assigned to the fundamental hydrogen-bound OH b -stretch. The weighted band maximum of the dimer OH b -stretch is located at ∼3452 cm -1 , red-shifted by ∼145 cm -1 from the monomer OH-stretching band. The gas-phase dimer assignment is supported by Ar matrix isolation FTIR experiments at 12 K and experiments with a partially deuterated sample. Computationally, we find the lowest energy structure of ( t -BuOOH) 2 to be a doubly hydrogen bound six-membered ring with non-optimal hydrogen bond angles. We estimate the gas-phase constant of dimer formation, K , to be 0.4 (standard pressure of 1 bar) using the experimental integrated absorbance and a theoretically determined oscillator strength of the OH b -stretching band.

Biodiversity monitoring at the community scale is a critical element of assessing and studying species distributions, ecology, diversity, and movements, and it is key to understanding and tracking environmental and anthropogenic effects on natural ecosystems. 1-4 Vertebrates in terrestrial ecosystems are experiencing extinctions and declines in both population numbers and sizes due to increasing threats from human activities and environmental change. 5-8 Terrestrial vertebrate monitoring using existing methods is generally costly and laborious, and although environmental DNA (eDNA) is becoming the tool of choice to assess biodiversity, few sample types effectively capture terrestrial vertebrate diversity. We hypothesized that eDNA captured from air could allow straightforward collection and characterization of terrestrial vertebrate communities. We filtered air at three localities in the Copenhagen Zoo: a stable, outside between the outdoor enclosures, and in the Rainforest House. Through metabarcoding of airborne eDNA, we detected 49 vertebrate species spanning 26 orders and 37 families: 30 mammal, 13 bird, 4 fish, 1 amphibian, and 1 reptile species. These spanned animals kept at the zoo, species occurring in the zoo surroundings, and species used as feed in the zoo. The detected species comprise a range of taxonomic orders and families, sizes, behaviors, and abundances. We found shorter distance to the air sampling device and higher animal biomass to increase the probability of detection. We hereby show that airborne eDNA can offer a fundamentally new way of studying and monitoring terrestrial communities., Competing Interests: Declaration of interests M.S.J. is Chief Science Officer at AirLabs, the company that designed and built the 3D-printed housings for the particle samplers used in this study. The blueprints of these housings are freely available and provided in Figure S1. All other air sampling equipment, i.e., the water vacuum, blower fans used for the 24 V and 5 V particle samplers, and batteries, are available in commercial companies not related to Airlabs. Thereby, the current study is not of direct commercial value to Airlabs. The remaining authors declare that they have no competing interests., (Copyright © 2021 The Author(s). Published by Elsevier Inc. All rights reserved.)

Functional and QoL outcomes were compared longitudinally in a cohort of patients treated for oropharyngeal squamous cell carcinoma (OPSCC) with primary transoral robotic surgery (TORS) or radiotherapy (RT). Forty-four patients undergoing primary TORS (n = 31) or RT (n = 13) for any stage OPSCC were included. Only low-stage disease was treated with TORS. Functional outcomes were: salivary flow rate, image-based swallowing function, and a self-reported 10-point scale comparing current swallowing function to baseline (CvB scale). QoL was assessed with European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core (EORTC QLQ-C30), Head & Neck Module (EORTC QLQ-HN35), and MD Anderson Dysphagia Inventory (MDADI). Shoulder impairment was assessed with Neck Dissection Impairment Index (NDII) and Oxford Shoulder Score (OSS). In the RT group, salivary flow rates had significantly declined at 12-month follow-up, with the biggest declines in QoL subscale scores recorded in the RT group for dry mouth and sticky saliva. Swallowing function on imaging studies was overall good, with no severe dysphagia within 1 year although, both treatment groups showed significant deterioration relative to baseline at the 12-month follow-up with increased DIGEST scores and pharyngeal retention. Shoulder impairment was rare at 1 year in both groups. A comprehensive examination of this cohort treated for OPSCC showed overall good functional and QoL outcomes 1 year after treatment. However, persistent impairment was seen in both groups with regards to swallowing function. In the TORS group, at 12-months follow-up, the QoL questionnaires showed worse scores in only one subscale (sticky saliva)., (© 2020 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

Introduction: The non-invasive prenatal test (NIPT) was introduced in the North Denmark Region in March 2013. NIPT is offered as an alternative to invasive tests if the combined first trimester risk of trisomy 21 (T21) is ≥ 1:300. The purpose of this study was to investigate the effect of NIPT implementation among high-risk pregnancies in a region with existing first-trimester combined screening for T21. The primary objective was to examine the effect on the invasive testing rate., Methods: This was a retrospective observational study including high-risk singleton pregnancies in the North Denmark Region. The women were included in two periods, i.e. before and after the implementation of NIPT, respectively. Group 1 (before NIPT): n = 253 and Group 2 (after NIPT): n = 302., Results: After NIPT implementation, the invasive testing rate fell from 70% to 48% (p < 0.01), and the number of high-risk women refusing further testing dropped from 26% to 3% (p < 0.01). NIPT successfully detected four cases of T21; however, two out of three sex-chromosomal abnormalities were false positives. No false negative NIPT results were revealed in this study., Conclusions: In the North Denmark Region, the implementation of NIPT in high-risk pregnancies significantly reduced the rate of invasive testing. However, the proportion of high-risk women who opted for prenatal tests increased as the majority of women who previously refused further testing now opted for the NIPT., Funding: none., Trial Registration: The study was approved by the Danish Data Protection Agency (No. 2015-104)., (Articles published in the Danish Medical Journal are “open access”. This means that the articles are distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits any non-commercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.)

Unlabelled: The diagnosis of pulmonary embolism (PE) is usually established by a combination of clinical assessment, D-dimer testing, and imaging with either pulmonary ventilation-perfusion (V/Q) scintigraphy or pulmonary multidetector CT (MDCT) angiography. Both V/Q SPECT and MDCT angiography seem to have high diagnostic accuracy. However, only limited data directly comparing these 2 modalities are available. Hybrid gamma-camera/MDCT systems have been introduced and allow simultaneous 3-dimensional lung V/Q SPECT and MDCT angiography, suitable for diagnosing PE. The aim of our study was to compare, in a prospective design, the diagnostic ability of V/Q SPECT, V/Q SPECT combined with low-dose CT, and pulmonary MDCT angiography obtained simultaneously using a combined SPECT/MDCT scanner in patients suspected of having PE., Methods: Consecutive patients from June 2006 to February 2008 suspected of having acute PE were referred to the Department of Nuclear Medicine at Rigshospitalet or Frederiksberg Hospital, Denmark, for V/Q SPECT as a first-line imaging procedure. The number of eligible patients was 196. Patients with positive D-dimer results (>0.5 mmol/mL) or a clinical assessment with a Wells score greater than 2 were included and underwent V/Q SPECT, low-dose CT, and pulmonary MDCT angiography in a single session. Patient follow-up was 6 mo., Results: A total of 81 simultaneous studies were available for analysis, of which 38% were from patients with PE. V/Q SPECT had a sensitivity of 97% and a specificity of 88%. When low-dose CT was added, the sensitivity was still 97% and the specificity increased to 100%. Perfusion SPECT with low-dose CT had a sensitivity of 93% and a specificity of 51%. MDCT angiography alone had a sensitivity of 68% and a specificity of 100%., Conclusion: We conclude that V/Q SPECT in combination with low-dose CT without contrast enhancement has an excellent diagnostic performance and should therefore probably be considered first-line imaging in the work-up of PE in most cases.