Publications by authors named "Goenter Vermeeren"

Secondary interactions, such as hydrogen bonding or phase separation, can enhance the stability of dynamic covalent materials without compromising on desired dynamic properties. Here, we investigate the combination of multiple secondary interactions in dynamic covalent materials based on acylsemicarbazides (ASCs), with the aim of achieving tunable material properties. The effects of different ASC substituents on the dynamic covalent and hydrogen bonding capabilities were investigated in a small molecule study using a combined experimental and theoretical approach, and revealed the presence of cooperative hydrogen-bonding interactions in 2 directions in one of the derivatives.

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Article Synopsis
  • Aliphatic amines are a diverse group of amines crucial in various industries like chemistry, agriculture, and medicine, but their production currently relies heavily on unsustainable fossil feedstock, raising health and safety concerns.
  • Shifting to biomass, particularly cellulose and hemicellulose, offers a sustainable alternative for producing these amines, as these materials are abundant and can undergo necessary chemical transformations.
  • The production process for bio-based aliphatic amines is part of a larger circular value chain that includes refining biomass, creating suitable substrates, and incorporating the amines into applications, highlighting the need for a comprehensive approach to address challenges at each stage.
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Herein, we dismiss a recent proposal by Civiš, Hobza, and co-workers to modify the IUPAC definition of hydrogen bonds in order to expand the scope from protonic Y-H to hydridic Y-H hydrogen-bond donor fragments [ , , 8550]. Based on accurate Kohn-Sham molecular orbital (KS-MO) analyses, we falsify the conclusion that interactions involving protonic and hydridic hydrogens are both hydrogen bonds; they are not. Instead, our quantitative KS-MO, energy decomposition, and Voronoi deformation density analyses reveal two fundamentally different bonding mechanisms for protonic Y-H and hydridic Y-H fragments which go with charge transfer in opposite directions.

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Nickel carbenes are key reactive intermediates in the catalytic cyclopropanation of olefins and other reactions, but isolated examples are scarce and generally rely on low coordination numbers (≤3) to stabilize the metal-ligand multiple bond. Here we report the isolation and characterization of a stable tetracoordinated nickel carbene bearing a triphosphine pincer ligand. Its nucleophilic character is evidenced by reaction with acids, and it can transfer the carbene fragment to CO to form a ketene.

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Background: The frailty index (FI) is commonly used to estimate frailty in end-stage kidney disease (ESKD) patients. The Clinical Frailty Scale (CFS) is a less time-consuming alternative. We aimed to determine the test performance of the CFS for pre-dialysis and dialysis patients and patients receiving conservative therapy from the Dialysis Centre Apeldoorn.

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Objective: Using benzodiazepines and certain antidepressants is associated with an increased risk of motor vehicle crashes due to impaired driving skills. Hence, several countries prohibit people who use these drugs from driving. Traffic regulations for driving under the influence of these drugs are, however, largely based on single-dose studies with healthy participants.

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In this presented study, we measured in situ the uplink duty cycles of a smartphone for 5G NR and 4G LTE for a total of six use cases covering voice, video, and data applications. The duty cycles were assessed at ten positions near a 4G and 5G base-station site in Belgium. For Twitch, VoLTE, and WhatsApp, the duty cycles ranged between 4% and 22% in time, both for 4G and 5G.

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Objectives/hypotheses: The purpose of this study was to investigate voice and communication difficulties in transmasculine individuals to develop evidence-based voice and communication training programs.

Study Design: Qualitative study.

Methods: Eight transmasculine individuals, who had received testosterone therapy (TT) for at least 1year, were included in this study.

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Correction for 'Not antiaromaticity gain, but increased asynchronicity enhances the Diels-Alder reactivity of tropone' by Eveline H. Tiekink , , 2023, , 3703-3706, https://doi.org/10.

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Correction for 'Pericyclic reaction benchmarks: hierarchical computations targeting CCSDT(Q)/CBS and analysis of DFT performance' by Pascal Vermeeren , , 2022, , 18028-18042, https://doi.org/10.1039/D2CP02234F.

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B-cell precursor acute lymphoblastic leukemia (BCP-ALL) can hijack the normal bone marrow microenvironment to create a leukemic niche which facilitates blast cell survival and promotes drug resistance. Bone marrow-derived mesenchymal stromal cells (MSC) mimic this protective environment in ex vivo co-cultures with leukemic cells obtained from children with newly diagnosed BCP-ALL. We examined the potential mechanisms of this protection by RNA sequencing of flow-sorted MSC after co-culture with BCP-ALL cells.

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Background: Patients treated for Lyme borreliosis (LB) frequently report persistent symptoms. Little is known about risk factors and etiology.

Methods: In a prospective observational cohort study with a follow-up of one year, we assessed a range of microbiological, immunological, genetic, clinical, functional, epidemiological, psychosocial and cognitive-behavioral variables as determinants of persistent symptoms after treatment for LB.

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Modern infrastructure heavily relies on robust concrete structures, underscoring the critical need for effective monitoring to ensure their safety and durability. This paper addresses this imperative issue by introducing an innovative automated and wireless system for continuous structural monitoring. By employing embedded electrical resistivity sensors coupled with a wireless-based data transmission mechanism, real-time data collection becomes feasible.

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Excessive daytime sleepiness is the core symptom of central disorders of hypersomnolence (CDH) and can directly impair driving performance. Sleepiness is reflected in relative alterations in distal and proximal skin temperature. Therefore, we examined the predictive value of skin temperature on driving performance.

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Background: Hospital care organization, structured around medical specialties and focused on the separate treatment of individual organ systems, is challenged by the increasing prevalence of multimorbidity. To support the hospitals' realization of multidisciplinary care, we hypothesized that using machine learning on clinical data helps to identify groups of medical specialties who are simultaneously involved in hospital care for patients with multimorbidity.

Methods: We conducted a cross-sectional study of patients in a Dutch general hospital and used a fuzzy c-means clustering algorithm for the analysis.

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Objectives: This study aims to develop and pilot a hospital care coordination team intervention for patients with multimorbidity and identify key uncertainties.

Methods: Practice-based, participatory pilot study with mixed methods in a middle-large teaching hospital. We included adult patients who had visited seven or more outpatient specialist clinics in 2018.

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The symmetry-decomposed Voronoi deformation density (VDD) charge analysis is an insightful and robust computational tool to aid the understanding of chemical bonding throughout all fields of chemistry. This method quantifies the atomic charge flow associated with chemical-bond formation and enables decomposition of this charge flow into contributions of (1) orbital interaction types, that is, Pauli repulsive or bonding orbital interactions; (2) per irreducible representation (irrep) of any point-group symmetry of interacting closed-shell molecular fragments; and now also (3) interacting open-shell (i.e.

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We have quantum chemically studied the influence of ring strain on the competition between the two mechanistically different S 2 and E2 pathways using a series of archetypal ethers as substrate in combination with a diverse set of Lewis bases (F , Cl , Br , HO , H CO , HS , H CS ), using relativistic density functional theory at ZORA-OLYP/QZ4P. The ring strain in the substrate is systematically increased on going from a model acyclic ether to a 6- to 5- to 4- to 3-membered ether ring. We have found that the activation energy of the S 2 pathway sharply decreases when the ring strain of the system is increased, thus on going from large to small cyclic ethers, the S 2 reactivity increases.

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We have studied the uncatalyzed and Lewis acid (LA)-catalyzed cycloaddition reaction between tropone and 1,1-dimethoxyethene using dispersion-corrected relativistic density functional theory (DFT). The LA catalysts BF , B(C H ) , and B(C F ) efficiently accelerate both the competing [4+2] and [8+2] cycloaddition reactions by lowering the activation barrier up to 12 kcal mol compared to the uncatalyzed reaction. Our study reveals that the LA catalyst promotes both cycloaddition reaction pathways by LUMO-lowering catalysis and demonstrates that Pauli-lowering catalysis is not always the operative catalytic mechanism in cycloaddition reactions.

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Background: Bringing together professionals with different knowledge and skills comes with the opportunity to spur the innovativeness of primary care teams. Nevertheless, empirical evidence shows that it is not self-evident that these innovations are also realized. The social categorization theory suggests that a better understanding of whether these potential team innovations are realized can be obtained by looking at the social cohesion of such teams.

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Tropone is an unreactive diene in normal electron demand Diels-Alder reactions, but it can be activated carbonyl umpolung by using hydrazone ion analogs. Recently, the higher reactivity of hydrazone ion analogs was ascribed to a raised HOMO energy induced by antiaromaticity (L. J.

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It is assumed that people practiced woodland management, i.e., coppicing and pollarding, in prehistory, but details are poorly known.

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