Empirical Parameters for Solvent Acidity, Basicity, Dipolarity, and Polarizability of the Ionic Liquids [BMIM][BF₄] and [BMIM][PF₆]

The empirical solvent scales for polarizability (SP), dipolarity (SdP), acidity (SA), and basicity (SB) have been successfully used to interpret the solvatochromism of compounds dissolved in organic solvents and their solvent mixtures. Providing that the published solvatochromic parameters for the ionic liquids 1-(1-butyl)-3-methylimidazolium tetrafluoroborate, [BMIM]­[BF₄] and 1-(1-butyl)-3-methylimidazolium hexafluorophosphate, [BMIM]­[PF₆], are excessively widespread, their SP, SdP, SA, and SB values are measured herein at temperatures from 293 to 353 K. Four key points are emphasized herein: (i) the origin of the solvatochromic solvent scales −the gas phase, that is the absence of any medium perturbation-; (ii) the separation of the polarizability and dipolarity effects; (iii) the simplification of the probing process in order to obtain the solvatochromic parameters; and (iv) the SP, SdP, SA, and SB solvent scales can probe the polarizability, dipolarity, acidity, and basicity of ionic liquids as well as of organic solvents and water–organic solvent mixtures. From the multiparameter approach using the four pure solvent scales one can draw the conclusion that (a) the solvent influence of [BMIM]­[BF₄] parallels that of formamide at 293 K, both of them miscible with water; (b) [BMIM]­[PF₆] shows a set of solvatochromic parameters similar to that of chloroacetonitrile, both of them water insoluble; and (c) that the corresponding solvent acidity and basicity of the ionic liquids can be explained to a great extent from the cation species by comparing the empirical parameters of [BMIM]⁺ with those of the solvent 1-methylimidazole. The insolubility of [BMIM]­[PF₆] in water as compared to [BMIM]­[BF₄] is tentatively connected to some extent to the larger molar volume of the anion [PF₆]⁻, and to the difference in basicity of [PF₆]^<b>–</b> and [BF₄]⁻

Current status and future challenges of genotoxicity OECD test guidelines (TGs) for nanomaterials: a workshop report

From Crossref journal articles via Jisc Publications RouterHistory: epub 2023-05-26, issued 2023-05-26Article version: AMPublication status: PublishedGenotoxicity testing for nanomaterials remains challenging as standard testing approaches require some adaptation, and further development of nano-specific OECD Test Guidelines (TGs) and Guidance Documents (GDs) are needed. However, the field of genotoxicology continues to progress and new approach methodologies (NAMs) are being developed that could provide relevant information on the range of mechanisms of genotoxic action that may be imparted by nanomaterials. There is a recognition of the need for implementation of new and/or adapted OECD TGs, new OECD GDs and utilisation of NAMs within a genotoxicity testing framework for nanomaterials. As such, the requirements to apply new experimental approaches and data for genotoxicity assessment of nanomaterials in a regulatory context is neither clear, nor used in practice. Thus, an international workshop with representatives from regulatory agencies, industry, government, and academic scientists was convened to discuss these issues. The expert discussion highlighted the current deficiencies that exist in standard testing approaches within exposure regimes, insufficient physico-chemical characterisation, lack of demonstration of cell or tissue uptake and internalisation, and limitations in the coverage of genotoxic modes of action. Regarding the latter aspect, a consensus was reached on the importance of using NAMs to support the genotoxicity assessment of nanomaterials. Also highlighted was the need for close engagement between scientists and regulators to 1) provide clarity on the regulatory needs, 2) improve the acceptance and use of NAMs-generated data, and 3) define how NAMs may be used as part of Weight of Evidence approaches for use in regulatory risk assessments

D-2 Physiognomy, Art, and Artifice in The Rape of Lucrece and The Devil’s Law-Case

Critics have noted two predominant, competing attitudes toward art in the Renaissance. For some, art was problematic because its artifice obfuscated reality. For others, art elevated humankind by allowing artists to create, like God. Early modern artistic treatises, however, reveal that artists also valued art because of its physiognomic ability. In other words, they believed that art could communicate the painted individual’s true nature, attitude, and perhaps even secrets, especially through the face, a theory about art literary critics largely overlook. But even as artists acknowledged art’s epistemological power, they also faced the potential idealization undertaken in any artistic endeavor, especially portraits, works of art most likely to signify physiognomically. These varied approaches to and ideas about art also appear in Renaissance literature. While many texts consider the status of art, in William Shakespeare’s poem The Rape of Lucrece, the titular protagonist directly articulates and confronts the tension between art as physiognomic communicator and artificial epistemological obstructer, with a particular focus on the overlooked role of physiognomy and art. A similar interrogation of art’s illuminative vs. deceptive status occurs in John Webster’s drama The Devil’s Law-Case. Yet Webster’s text takes into account something Lucrece does not, the important role gender plays in both the creation and reception of art. Thus, by carefully considering the characterization of art in both The Rape of Lucrece and The Devil’s Law-Case, we can examine the importance of physiognomy and gender, respectively, to Renaissance art’s complicated status

Safety of hospital discharge before return of bowel function after elective colorectal surgery

Background Ileus is common after colorectal surgery and is associated with an increased risk of postoperative complications. Identifying features of normal bowel recovery and the appropriateness for hospital discharge is challenging. This study explored the safety of hospital discharge before the return of bowel function. Methods A prospective, multicentre cohort study was undertaken across an international collaborative network. Adult patients undergoing elective colorectal resection between January and April 2018 were included. The main outcome of interest was readmission to hospital within 30 days of surgery. The impact of discharge timing according to the return of bowel function was explored using multivariable regression analysis. Other outcomes were postoperative complications within 30 days of surgery, measured using the Clavien-Dindo classification system. Results A total of 3288 patients were included in the analysis, of whom 301 (9 center dot 2 per cent) were discharged before the return of bowel function. The median duration of hospital stay for patients discharged before and after return of bowel function was 5 (i.q.r. 4-7) and 7 (6-8) days respectively (P &lt; 0 center dot 001). There were no significant differences in rates of readmission between these groups (6 center dot 6 versus 8 center dot 0 per cent; P = 0 center dot 499), and this remained the case after multivariable adjustment for baseline differences (odds ratio 0 center dot 90, 95 per cent c.i. 0 center dot 55 to 1 center dot 46; P = 0 center dot 659). Rates of postoperative complications were also similar in those discharged before versus after return of bowel function (minor: 34 center dot 7 versus 39 center dot 5 per cent; major 3 center dot 3 versus 3 center dot 4 per cent; P = 0 center dot 110). Conclusion Discharge before return of bowel function after elective colorectal surgery appears to be safe in appropriately selected patients