4,4′-Dimethylazobenzene as a chemical actinometer

Chemical actinometers are a useful tool in photochemistry, which allows to measure the photon flux of a light source to carry out quantitative analysis on photoreactions. The most commonly employed actinometers so far show minor drawbacks, such as difficult data treatment, parasite reactions, low stability or impossible reset. We propose herewith the use of 4,4′-dimethylazobenzene as a chemical actinometer. This compound undergoes a clean and efficient E/Z isomerization, approaching total conversion upon irradiation at 365 nm. Thanks to its properties, it can be used to determine the photon flux in the UV–visible region, with simple experimental methods and data treatment, and with the possibility to be reused after photochemical or thermal reset. Graphical abstract

Application of Unsupervised Multivariate Analysis Methods to Raman Spectroscopic Assessment of Human Dental Enamel

This work explores the suitability of data treatment methodologies for Raman spectra of teeth using multivariate analysis methods. Raman spectra were measured in our laboratory and obtained from control enamel samples and samples with a protective treatment before and after an erosive attack. Three different approaches for data treatment were undertaken in order to evaluate the aptitude of distinguishing between groups: A—Principal Component Analysis of the numerical parameters derived from deconvoluted spectra; B—PCA of average Raman spectra after baseline correction; and C—PCA of average raw Raman spectra. Additionally, Hierarchical Cluster Analysis were applied to Raman spectra of enamel measured with different laser wavelengths (638 nm or 785 nm) to evaluate the most suitable choice of illumination. According to the different approaches, PC1 scores obtained between control and treatment group were A—50.5%, B—97.1% and C—83.0% before the erosive attack and A—55.2%, B—93.2% and C—87.8% after an erosive attack. The obtained results showed that performing PCA analysis of raw or baseline corrected Raman spectra of enamel was not as efficient in the evaluation of samples with different treatments. Moreover, acquiring Raman spectra with a 785 nm laser increases precision in the data treatment methodologies.

The Space and Terrestrial Weather Variations as Possible Factors for Ischemia Events in Saint Petersburg

The Space and Terrestrial Weather (Weather Complex) impact on ischemia cases in Saint Petersburg is investigated. The results show the main feature of the Weather Complex when it was related to the days of the different ischemia situations in the different ischemia people gender groups. The data treatment was done with some elements of the Folder Epochs Method, Cluster Analysis and the Mann–Whitney hypothesis test criterion.

Applied Research Paradigms

This chapter discusses the research paradigms underpinning this study––i.e. dialectical pluralism (DP) (mixed methods research) and a complex thinking perspective. The chapter also explains the researcher’s scientific and personal paradigm biases and details some strategies utilised for objective data treatment.

Case Selection Criteria, Methods, and Data Treatment

This chapter examines the criteria for selecting the cases analysed in this study. It explains the application of critical discourse analysis (CDA) as its principal empirical method. It discusses CDA methods and data treatment as well as the empirical analysis of CDA results. Finally, it compares and summarises the case selection criteria.Four countries were compared: Switzerland, Uruguay, Cuba, and Colombia. These cases are also linked to the correlated variables in the quantitative model and to the sufficient conditions in the QCA. Cases were selected based on the “extreme case method”.Each of the selected countries serves as a proxy of a larger group of countries (Latin American Strong Catholic, Secular, Communism, Protestant or mixed Old World.).Critical discourse analysis (CDA) and religion constitute the qualitative method (micro-component). Sixty semi-structured interviews were conducted and analysed using memos and open coding.

EP.WE.93An Overview of the Effect of COVID-19 on the General Surgical Take: Before, During and After the First UK National Lockdown

Aims Emergency general surgical (EGS) services have faced new challenges during the coronavirus pandemic. This study compared all EGS presentations before, during and after the first UK national lockdown between March and May 2020. Methods All EGS patients presenting to our centre in four separate weeks were included. These weeks represented ‘pre-lockdown’, ‘early lockdown’, ‘established lockdown’ and ‘post lockdown’ groups. Demographic data, treatment, admission and outcomes were collected for all patients and compared between groups. Results 178 patients accounted for 214 EGS attendances over four weeks. Attendances decreased from 74 pre-lockdown, to 43 in early lockdown, 32 in late lockdown and rose to 65 in the post lockdown group. Significantly more patients received repeat outpatient reviews in the lockdown groups (p = 0.002). Length of stay was significantly reduced in established lockdown (0.5 days vs. 2 days pre-lockdown, p = 0.042). There was a trend towards conservative management of surgical pathology in the lockdown groups (65% vs 47% pre and post-lockdown, p = 0.10). No very elderly or frail EGS patients presented during the lockdown study period. There was no evidence of delay to presentation. Conclusions The COVID-19 pandemic and UK Coronavirus lockdown resulted in a large decrease in EGS admissions and alteration in characteristics of these admissions. New national guidance during the pandemic advocated ambulatory and conservative management of surgical conditions where possible and is reflected in our cohort. These changes reverted almost back to pre-lockdown state the week following the easing of the first UK national lockdown.

Merging Water Research, Analytical Chemistry, and Agile Management to Shape Prospective Professionals through the Project-Centred Collaborative Approach Focusing on Water Bodies Rather Than Water Samples

Professionals of different disciplines, including chemists and chemical engineers, engage in water research, even though they might not have been extensively trained in it during their studies. We describe a project-centred master level subject “Water as a Hydrogeological, Ecological, and Analytical System”, which, by focussing on waterbodies instead of a particular aspect of water quality, merges total analytical process with water research and, by a considerate choice of chemical parameters, enables students to apply water-research-specific data-treatment techniques, including the Piper and Stiff diagram, to discuss water genesis, processes in water, and influences on waterbodies. Agile management, initiated in computer engineering in 2001, is believed to contribute to better products in a shorter time. We demonstrate how its incorporation into the organisational scheme helped students self-organise, handle their projects, and collaborate within and between groups. Student’s expressions confirm their overall satisfaction, motivation, and that the omission of the final classical exam had no adverse effects on the learning outcomes. Their consent with different benefits of the project-centred collaborative approach and their self-efficacy beliefs, respectively, expressed as mean values in a five-grade Likert scale ranged from 4.26 to 5.00 and from 4.32 to 5.00. Regarding the students’ time investment, the project-centred approach as the mean grade 3 confirmed is not recognised as an easier way. We provide partially self-calculating, self-notifying Excel spreadsheet tables as Supplementary Material to ease the implementation of water research data-treatment techniques, which help students collaborate and discuss their subject extensively.