Noncovalent Modulation of Chemoselectivity in the Gas Phase Leads to a Switchover in Reaction Type from Heterolytic to Homolytic to Electrocyclic Cleavage

In the gas phase, thermal activation of supramolecular assemblies such as host-guest complexes leads commonly to noncovalent dissociation into the individual components. Chemical reactions, for example of encapsulated guest molecules, are only found in exceptional cases. As observed by mass spectrometry, when 1-amino-methyl-2,3-diazabicyclo[2.2.2]oct-2-ene (DBOA) is complexed by the macrocycle β-cyclodextrin, its protonated complex undergoes collision-induced dissociation into its components, the conventional reaction pathway. Inside the macrocyclic cavity of cucurbit[7]uril (CB7), a competitive chemical reaction of monoprotonated DBOA takes place upon thermal activation, namely a stepwise homolytic covalent bond cleavage with the elimination of N2 , while the doubly protonated CB7⋅DBOA complex undergoes an inner-phase elimination of ethylene, a concerted, electrocyclic ring-opening reaction. These chemical reaction pathways stand in contrast to the gas-phase chemistry of uncomplexed monoprotonated DBOA, for which an elimination of NH3 predominates upon collision-induced activation, as a heterolytic bond cleavage reaction. The combined results, which can be rationalized in terms of organic-chemical reaction mechanisms and density-function theoretical calculations, demonstrate that chemical reactions in the gas phase can be steered chemoselectively through noncovalent interactions

The effect of aggression management training programmes for nursing staff and students working in an acute hospital setting. A narrative review of current literature

BACKGROUND: Patient aggression is a longstanding problem in general hospital nursing. Staff training is recommended to tackle workplace aggression originating from patients or visitors, yet evidence on training effects is scarce. AIMS: To review and collate current research evidence on the effect of aggression management training for nurses and nursing students working in general hospitals, and to derive recommendations for further research. DESIGN: Systematic, narrative review. DATA SOURCES: Embase, MEDLINE, the Cochrane library, CINAHL, PsycINFO, pubmed, psycArticles, Psychology and Behavioural Sciences Collection were searched for articles evaluating training programs for staff and students in acute hospital adult nursing in a 'before/after' design. Studies published between January 2000 and September 2011 in English, French or German were eligible of inclusion. REVIEW METHODS: The methodological quality of included studies was assessed with the 'Quality Assessment Tool for Quantitative Studies'. Main outcomes i.e. attitudes, confidence, skills and knowledge were collated. RESULTS: Nine studies were included. Two had a weak, six a moderate, and one a strong study design. All studies reported increased confidence, improved attitude, skills, and knowledge about risk factors post training. There was no significant change in incidence of patient aggression. CONCLUSION: Our findings corroborate findings of reviews on training in mental health care, which point to a lack of high quality research. Training does not reduce the incidence of aggressive acts. Aggression needs to be tackled at an organizational level

Comparing Cathelicidin Susceptibility of the Meningitis Pathogens Streptococcus suis and Escherichia coli in Culture Medium in Contrast to Porcine or Human Cerebrospinal Fluid

Host defense peptides or antimicrobial peptides (AMPs), e.g., cathelicidins, have recently been discussed as a potential new treatment option against bacterial infections. To test the efficacy of AMPs, standardized methods that closely mimic the physiological conditions at the site of infection are still needed. The aim of our study was to test the meningitis-causing bacteria Streptococcus suis and Escherichia coli for their susceptibility to cathelicidins in culture medium versus cerebrospinal fluid (CSF). Susceptibility testing was performed in analogy to the broth microdilution method described by the Clinical and Laboratory Standard Institute (CLSI) to determine minimum inhibitory concentrations (MICs) of antimicrobial agents. MICs were determined using cation-adjusted Mueller–Hinton broth (CA-MHB), lysogeny broth (LB), Roswell Park Memorial Institute medium (RPMI) or Dulbecco’s Modified Eagle’s Medium (DMEM) (the latter two supplemented with 5% CA-MHB or blood) and compared with MICs obtained in porcine or human CSF. Our data showed that MICs obtained in CA-MHB as recommended by CLSI do not reflect the MICs obtained in the physiological body fluid CSF. However, the MICs of clinical isolates of S. suis tested in RPMI medium supplemented with CA-MHB, were similar to those of the same strains tested in CSF. In contrast, the MICs in the human CSF for the tested E. coli K1 strain were higher compared to the RPMI medium and showed even higher values than in CA-MHB. This highlights the need for susceptibility testing of AMPs in a medium that closely mimics the clinically relevant conditions

A probabilistic generative model for GO enrichment analysis

The Gene Ontology (GO) is extensively used to analyze all types of high-throughput experiments. However, researchers still face several challenges when using GO and other functional annotation databases. One problem is the large number of multiple hypotheses that are being tested for each study. In addition, categories often overlap with both direct parents/descendents and other distant categories in the hierarchical structure. This makes it hard to determine if the identified significant categories represent different functional outcomes or rather a redundant view of the same biological processes. To overcome these problems we developed a generative probabilistic model which identifies a (small) subset of categories that, together, explain the selected gene set. Our model accommodates noise and errors in the selected gene set and GO. Using controlled GO data our method correctly recovered most of the selected categories, leading to dramatic improvements over current methods for GO analysis. When used with microarray expression data and ChIP-chip data from yeast and human our method was able to correctly identify both general and specific enriched categories which were overlooked by other methods

The role of Ovotransferrin in egg-white antimicrobial activity: a review

Eggs are a whole food which affordably support human nutritional requirements worldwide. Eggs strongly resist bacterial infection due to an arsenal of defensive systems, many of which reside in the egg white. However, despite improved control of egg production and distribution, eggs remain a vehicle for foodborne transmission of Salmonella enterica serovar Enteritidis, which continues to represent a major public health challenge. It is generally accepted that iron deficiency, mediated by the iron-chelating properties of the egg-white protein ovotransferrin, has a key role in inhibiting infection of eggs by Salmonella. Ovotransferrin has an additional antibacterial activity beyond iron-chelation, which appears to depend on direct interaction with the bacterial cell surface, resulting in membrane perturbation. Current understanding of the antibacterial role of ovotransferrin is limited by a failure to fully consider its activity within the natural context of the egg white, where a series relevant environmental factors (such as alkalinity, high viscosity, ionic composition, and egg white protein interactions) may exert significant influence on ovotransferrin activity. This review provides an overview of what is known and what remains to be determined regarding the antimicrobial activity of ovotransferrin in egg white, and thus enhances understanding of egg safety through improved insight of this key antimicrobial component of eggs

Rahmenkonzept der Universitäten des Landes Baden-Württemberg für das High-Performance Computing (HPC) und Data-Intensive Computing (DIC) für den Zeitraum 2025 bis 2032

Digitale Infrastrukturen und darauf aufsetzende Dienste bilden inzwischen in fast allen Fachgebieten das Rückgrat wissenschaftlicher Forschung. Deshalb muss die strategische Zielsetzung eines HPCKonzepts klare Antworten auf eine Vielzahl von Problemstellungen finden. Dazu zählen die stetige Zunahme digitaler Workflows, bedingt beispielsweise durch die Verbesserung des Instrumentariums in den Naturwissenschaften, neue Forschungsansätze in den Digital Humanities, die Verfeinerung der Auflösung in bildgebenden Verfahren, aber auch der zunehmende Einsatz Künstlicher Intelligenz in immer breiteren Anwendungsfeldern. Öffentlich geförderte und betriebene Forschungsinfrastrukturen sind hier von entscheidender Bedeutung. Föderierte Strukturen erzeugen Synergien und haben klare strategische Vorteile gegenüber vereinzelten Insellösungen, insbesondere im Bereich High-Performance-Computing/Data Intensive Computing (HPC-DIC). Daher müssen sie im Interesse der Nutzenden auf der lange etablierten Basis verlässlich, zukunftssicher und nachhaltig weiterentwickelt werden. Im Sinne des Wissenschafts- und Wirtschaftsstandorts Baden-Württemberg sollen sie eine für Menschen gemachte Digitalisierung voranbringen, moderne technische Entwicklungen mitgestalten, zusätzliche Kreativität freisetzen, und nicht zuletzt die breite Verteilung von Kompetenzen unterstützen. Basierend auf internationalen Standards sind digitale Dienste auf allen Ebenen (lokal, regional, national und international) geeignet zu vernetzen. Um den Standort Baden-Württemberg weiter attraktiv für Forscher, Entwickler und Dienstleister auszubauen, ist dies eine unverzichtbare Voraussetzung. Die Hochschulen im Land müssen sich im Hinblick auf die Anwerbung von IT-Fachkräften zu einem begehrten Arbeitgeber weiterentwickeln