Formative tests and assessments have high potential in supporting learning, especially for students with special educational needs. One approach to gain assessment information on student learning is to monitor learning progress. For that, multiple repeated tests are often performed by practitioners. In order to be useful in practice, tests must meet various interdependent quality criteria. A property of tests that touches various criteria as the utility and economy is the length. A test has t...

In dieser abschließenden Diskussion meiner kumulativen Dissertation werden die methodischen Herausforderungen der Konzipierung und Durchführung des dreieinhalbjährigen Forschungsprojekts im Rahmen des Gesamtprojekts „Chancengerechte Entwicklung von Frauenkarrieren im MINT-Bereich (CHEFIN)“ der TU Dortmund und der RWTH Aachen, das von Oktober 2017 bis März 2021 vom Bundesministeriums für Bildung und Forschung (BMBF) gefördert wurde, reflektiert. Ausgehend von der Tatsache, dass Frauen in MINT...

We investigate the association between Environmental, Social, and Governance (ESG) ratings and stock performance during the COVID-19 crisis. Although there is mixed evidence in the literature whether ESG is valuable in times of crisis, we find high ESG-rated European firms to be associated with higher abnormal returns and lower stock volatility. After decomposing ESG into its separate components, we find the social score to be the predominant driver of our results. Further, we argue that ESG ...

Combining carbon fiber reinforced polymers (CFRP) with steel offers the potential of utilizing the desired characteristics of both materials, such as specific strength/stiffness and fatigue strength of fiber reinforced polymers (FRP) and impact resistance of metals. Since in such hybrid laminates multiple material layers are combined, a gradual failure is likely that can lead to changes in mechanical properties. A failure of the metal partner leads to an increase in stress on the FRP, which u...

Additive manufacturing is a high-potential technique that allows the production of components with almost no limitation in complexity. However, one of the main factors that still limits the laser-based additive manufacturing is a lack of processable alloys such as carbon martensitic hardenable tool steels, which are rarely investigated due to their susceptibility to cold cracking. Therefore, this study aimed to expand the variety of steels for laser powder bed fusion (L-PBF) by investigating ...

DNA-encoded combinatorial synthesis provides efficient and dense coverage of chemical space around privileged molecular structures. The indole side chain of tryptophan plays a prominent role in key, or “hot spot”, regions of protein–protein interactions. A DNA-encoded combinatorial peptoid library was designed based on the Ugi four-component reaction by employing tryptophan-mimetic indole side chains to probe the surface of target proteins. Several peptoids were synthesized on a chemically st...

Enzymatic shortcut: Cyclic dinucleotides, which are of great interest to study immunology and immune oncology, can be synthesized in a one-step biotransformation significantly shortening the chemical synthesis route. The enzyme displays a surprisingly large substrate scope. Cyclic GMP-AMP synthase (cGAS) is a cytosolic DNA sensor that catalyzes the synthesis of the cyclic GMP-AMP dinucleotide 2′3′-cGAMP. 2′3′-cGAMP functions as inducer for the production of type I interferons. Derivatives of...

Numerous studies already identified that the fatigue strength of 316 L parts processed by laser beam melting (LBM) is distinctly affected by the surface integrity. Among others, surface defects as well as residual stresses are of crucial importance. Despite new findings in the field of surface engineering of laser beam melting (LBM) parts, the low cycle fatigue strength of thermally sprayed additively manufactured substrates has not been in the focus of research to date. This study aims at ev...

Controlling the activity of enzymes is an important feature for many processes in medicine, bioanalytics, and biotechnology. So far, it has not been possible to fully switch biocatalysts on and off by thermoresponsive enzyme inhibitors. Herein, we present poly(2-oxazoline)s with iminodiacetic acid end groups (POx-IDA) that are lower critical solution temperature (LCST) polymers and thus thermosensitive. They are capable of reversibly inhibiting the activity of horse radish peroxidase and lacc...

Research Summary Specialized knowledge can be a facilitator of entrepreneurial orientation (EO), but little is known about how management teams transform their knowledge resources into entrepreneurial activity. Complementing the knowledge-based view with social interdependence theory, we suggest that team processes mediate the impact of teams' transactive memory system (TMS) on EO. Our empirical analysis of data from interdisciplinary management teams shows that a strong TMS serves as a star...

Partition coefficients (K) of vitamins (riboflavin, nicotinic acid, nicotinamide, folic acid, cyanocobalamin) in aqueous two-phase systems (ATPS) composed by polyethylene glycol (PEG 4000, PEG 6000) and organic salt (sodium citrate and sodium tartrate) at T = 298.15 K and p = 1 bar have been studied. Data on liquid–liquid equilibria of the ATPS considered in this study have been taken from the literature (PEG-Na3Citrate) or measured in this work (PEG-Na2Tartrate) for PEG 4000 and PEG 6000 at ...

Herein, we report the syntheses of the water-soluble organotin compounds [{Me2(H)N(CH2)3}2SnX2]Y2 (1, X = Cl, Y = ClO4; 2, X = F, Y = ClO4) and {Me2(H)N(CH2)3}2SnX4 (3, X = Cl; 4, X = F). The compounds were characterized by elemental analysis, electrospray mass spectrometry, 1H, 13C, 19F, and 119Sn NMR spectroscopy, and in the case of compounds 1, 3 and 4, by single-crystal X-ray diffraction analysis. The reaction of compound 2 with fluoride anions in water was investigated by NMR spectroscop...

A procedure for the synthesis of tertiary amines via reductive amination of aldehydes with molecular hydrogen as a reducing agent using homogeneous rhodium catalysis is presented. Using an amine to aldehyde ratio of 4/1 enabled the synthesis of tertiary amines from nine different aldehydes and nine different secondary amines with selectivities up to 99% and turnover frequencies (TOF) up to 7200 h−1. The reaction showed a high tolerance against alcohol and ester functions allowing the formatio...

We report on the implementation of the concept of a photochemically elicited two-carbon homologation of a π-donor–π-acceptor substituted chromophore by triple-bond insertion. Implementing a phenyl connector between the slide-in module and the chromophore enabled the synthesis of cylohepta[b]indole-type building blocks by a metal-free annulative one-pot two-carbon ring expansion of the five-membered chromophore. Post-irradiative structural elaboration provided founding members of the indolo[2,...

In dieser Arbeit wurde das Verwitterungsverhalten unbehandelter und mit Steinschutzstoffen imprägnierter Baumberger, Schleeriether und Obernkirchener Sandsteine über einen Zeitraum von bis zu 30 Jahren analysiert. Ziel war es zu prüfen, ob eine hydrophobe Oberflächenausstattung im Vergleich zu nicht-behandelten Oberflächen auch auf lange Sicht in der Lage ist, Verwitterungseinflüsse deutlich zu verlangsamen und das Verwitterungspotential auf ein Minimum zu reduzieren. Ebenso erfolgte eine Eig...

Basierend auf der unorthodoxen geminalen Hydrierung von Alkinen wurden neuartige hydrierende Transformationen entwickelt, deren synthetischer Nutzen an ausgewählten Beispielen demonstriert, und zugrundeliegende mechanistische Fragestellungen experimentell und computergestützt untersucht. Im ersten Teil wurden Enine mittels Ruthenium-Katalysatoren zu Cycloalkenen oder Cyclopropanen umgesetzt, wobei die Selektivität der Reaktion über das Substitutionsmuster des olefinischen Carbenakzeptors kon...

Three novel bicycloazastannoxides, namely, [nBu2Sn(L1)] (1), [nBu2Sn(L2)] (2) and [Bz2Sn(L3)] (3) were synthesized in one pot procedures by reacting diorganotin(IV) precursors with a mixture composed of an α-amino acid with either (E)-2-hydroxy-5-((4-nitrophenyl)diazenyl)benzaldehyde or (E)-2-hydroxy-5-(phenyldiazenyl)benzaldehyde. Single-crystal X-ray diffraction analysis reveal that compound 1 is monomeric, compound 2 consists of both a monomer and a dimer, while compound 3 is a coordinatio...

Most metallo-supramolecular assemblies of low nuclearity adopt simple topologies, with bridging ligands spanning neighboring metal centers in a direct fashion. Here we contribute a new structural motif to the family of host compounds with low metal count (two) that consists of a pair of doubly-interlocked, Figure-eight-shaped subunits, also termed “lemniscates”. Each metal is chelated by two chiral bidentate ligands, composed of a peptidic macrocycle that resembles a natural product with two ...