RESUMEN
Photocatalytic reactions involving a reductive radical-polar crossover (RRPCO) generate intermediates with carbanionic reactivity. Many of these proposed intermediates resemble highly reactive organometallic compounds. However, conditions of their formation are generally not tolerated by their isolated organometallic versions and often a different reactivity is observed. Our investigations on their nature and reactivity under commonly used photocatalytic conditions demonstrate that these intermediates are indeed best described as free, superbasic carbanions capable of deprotonating common polar solvents usually assumed to be inert such as acetonitrile, dimethylformamide, and dimethylsulfoxide. Their basicity not only towards solvents but also towards electrophiles, such as aldehydes, ketones, and esters, is comparable to the reactivity of isolated carbanions in the gas-phase. Previously unsuccessful transformations thought to result from a lack of reactivity are explained by their high reactivity towards the solvent and weakly acidic protons of reaction partners. An intuitive explanation for the mode of action of photocatalytically generated carbanions is provided, which enables methods to verify reaction mechanisms proposed to involve an RRPCO step and to identify the reasons for the limitations of current methods.
RESUMEN
In today's data-intensive work environments, information systems are crucial for supporting workers. However, workers often do not rely on these systems but resort to workarounds. We argue that trust is essential for workers' reliance on information systems, positively affecting workers' cognitive resources, performance, and well-being. Moreover, we argue that the organisational context (accountability, distractions) and user-related factors qualify trust-outcome associations by affecting workers' trust calibration. In a preregistered study, we asked N = 291 employed users of information systems to re-experience prior everyday usage events (event reconstruction method) and assess event-specific trust in the system, work outcomes, and context conditions. Results confirmed the assumed association between trust in the information system and workers' ratings of both performance and well-being. Moreover, workers' technology competence and need for cognition - but not contextual conditions - qualified trust-outcome associations. Our results offer specific suggestions for achieving successful use of information systems at work.
This preregistered study with 291 employees demonstrates the importance of trust in information systems for workers' performance and well-being in everyday work events. User-related factors, namely, users' technology competence and need for cognition, further qualified these effects. Practical implications for active trust management are drawn.
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Hypoxia-induced neuroinflammation after cardiac arrest has been shown to be mitigated by different ventilation methods. In this prospective randomized animal trial, 35 landrace pigs were randomly divided into four groups: intermittent positive pressure ventilation (IPPV), synchronized ventilation 20 mbar (SV 20 mbar), chest compression synchronized ventilation 40 mbar (CCSV 40 mbar) and a control group (Sham). After inducing ventricular fibrillation, basic life support (BLS) and advanced life support (ALS) were performed, followed by post-resuscitation monitoring. After 6 hours, the animals were euthanized, and direct postmortem brain tissue samples were taken from the hippocampus (HC) and cortex (Cor) for molecular biological investigation of cytokine mRNA levels of Interleukin-6 (IL-6) and tumor necrosis factor alpha (TNFα). The data analysis showed that CCSV 40 mbar displayed low TNFα mRNA-levels, especially in the HC, while the highest TNFα mRNA-levels were detected in SV 20 mbar. The results indicate that chest compression synchronized ventilation may have a potential positive impact on the cytokine expression levels post-resuscitation. Further studies are needed to derive potential therapeutic algorithms from these findings.
Asunto(s)
Reanimación Cardiopulmonar , Paro Cardíaco , Animales , Reanimación Cardiopulmonar/métodos , Citocinas , Paro Cardíaco/terapia , Interleucina-6/genética , Estudios Prospectivos , ARN Mensajero , Porcinos , Factor de Necrosis Tumoral alfa/genéticaRESUMEN
We report on the synthesis and spectroscopic evidence for a sequence of structural transformations of a new defect-cubane type copper complex, [Cu4(pyalk)4(OAc)4](ClO4)(HNEt3), which acts as a pre-catalyst for water oxidation. In situ and post-catalytic studies showed that the tetrameric complex undergoes a structural transformation into dimeric and monomeric species, induced by water molecules and carbonate anions, respectively. Further, the observed electrocatalytic water oxidation activity has been confirmed to arise from in situ-generated Cu(II) oxidic nanostructures at the electrode interface.
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As a sudden, external event, the COVID-19 pandemic rapidly disrupted the workplace and required organizations to digitalize their working approaches. To understand how such external events affect organizations in the short- and long-term, we investigated the case of a higher education institution's administration, which combines features of public and private organizations. We applied a longitudinal case study and conducted interviews with 39 German higher education institution (HEI) employees at two time points during the first (2020) and second (2021) lockdown. Content analyses revealed that a general openness toward change and distinct technical infrastructure enabled efficient coping with the pandemic despite struggles with digitalization and rigidity. Advantages in work outcomes were contrasted with losses in social interactions. Flexible models (e.g., working from home or the office) were desirable long-term work concepts. We integrated our findings in a framework on factors that contribute to supporting organizational adaptations and derived practical recommendations.
RESUMEN
Safety is a major issue in the embalming procedures of human cadavers. Reduced application of formaldehyde is often recommended. The aim of this study was to investigate the potency of ultraviolet light (UV-C irradiation) on the bacterial load on the surface of a conserved human cadaver. To test UV-C irradiation, the cadaver was laid out in the dissection hall and, after preparation of the muscles, was covered with linen sheets moistened with water. Swabs of the surface and microbiological analysis revealed sporadic bacterial colonies. The surface area was then spiked with bacteria and irradiated by a UV lamp for 15 or 60 min. Half of the area was covered by aluminum foil to serve as a control. After exposition, swabs were taken and analyzed. The exposition had reduced the number of colonies to one third (15 min exposition) and to one tenth (60 min exposition) of the control area. Thus, UV-C irradiation could be used in the preservation of cadavers without chemical pollution of the environment and without any risk for the employees. Clin. Anat. 32:113-116, 2019. © 2019 Wiley Periodicals, Inc.