Publications by authors named "Meijer J"

Daylength (i.e., photoperiod) provides essential information for seasonal adaptations of organisms.

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Context: Insulin sensitivity and secretion indices can be useful tools in understanding insulin homeostasis in children at risk for diabetes. There have been few studies examining the reproducibility of these measures in pediatrics.

Objective: To determine whether fasting or oral glucose tolerance test (OGTT)-derived insulin measures would be more reproducible and whether there would be differences based on weight, sex, race, and pubertal status.

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In both diurnal and nocturnal species, the neurons in the suprachiasmatic nucleus (SCN) generate a daily pattern in which the impulse frequency peaks at midday and is lowest during the night. This pattern, common to both day-active and night-active species, has led to the long-standing notion that their functional difference relies merely on a sign reversal in SCN output. However, recent evidence shows that the response of the SCN to the animal's physical activity is opposite in nocturnal and diurnal animals.

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Objectives: To improve the identification of anaerobic bacteria, the identity of clinical isolates which could not be identified using MALDI-TOF MS was assessed using whole genome sequencing (WGS) and in-house made main spectral profiles (MSPs) were created. Four novel Anaerococcus species, each represented by at least two isolates, were encountered.

Methods: The novelty of the isolates was confirmed by comparing the 16S rRNA gene sequences and the WGS with their closest relatives.

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A uniform solidification front undergoes nontrivial deformations when encountering an insoluble dispersed particle in a melt. For solid particles, the overall deformation characteristics are primarily dictated by heat transfer between the particle and the surrounding, remaining unaffected by the rate of approach of the solidification front. In this Letter we show that, conversely, when interacting with a droplet or a bubble, the deformation behavior exhibits entirely different and unexpected behavior.

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Autism spectrum disorder ("autism") is a neurodevelopmental condition characterized by substantial behavioral and neuroanatomical heterogeneity. This poses significant challenges to understanding its neurobiological mechanisms and developing effective interventions. Identifying phenotypically more homogeneous subgroups and shifting the focus from average group differences to individuals is a promising approach to addressing heterogeneity.

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Background: Per- and polyfluoroalkyl substances (PFAS) are a class of persistent synthetic chemicals that are found in human milk and are associated with negative health effects. Research suggests that PFAS affect both lactation and the human metabolome.

Methods: We measured perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) in the milk of 425 participants from the New Hampshire Birth Cohort Study using liquid chromatography-tandem mass spectrometry (LC-MS/MS).

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Article Synopsis
  • Effect-Directed Analysis (EDA) was utilized to pinpoint bioactive compounds in surface and well water from the Upper Rhine, assessing their persistence and toxicity based on PMT and vPvM criteria.
  • A multi-layered solid-phase extraction enriched polar substances, leading to the fractionation of samples into 108 parts that underwent testing with specific bioassays to identify bioactive compounds.
  • The study successfully identified ten bioactive substances, including several classified as PMT/vPvM, highlighting the role of EDA in environmental risk assessment and regulatory prioritization.
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Per- and polyfluoroalkyl substances (PFAS) have been detected in the blood of humans and animals worldwide. Exposure to some PFAS are associated with multiple adverse pregnancy outcomes. Existing literature has identified a strong association with PFAS exposure and metabolic dysfunction in humans, including modification of lipid metabolism.

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The self-organization of clusters of particles is a fundamental phenomenon across various physical systems, including hydrodynamic and colloidal systems. One example is that of dense spherical particles submerged in a viscous fluid and subjected to horizontal oscillations. The interaction of the particles with the oscillating flow leads to the formation of one-particle-thick chains or multiple-particle-wide bands, both oriented perpendicular to the oscillation direction.

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Eveningness has been associated with both disturbed sleep and depression. It is unclear, however, if deprived sleep explains evening types' vulnerability to depression. The role of pre-sleep rumination in these associations also remains understudied.

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Spectral imaging has many applications, from methane detection using satellites to disease detection on crops. However, spectral cameras remain a costly solution ranging from 10 thousand to 100 thousand euros for the hardware alone. Here, we present a low-cost multispectral camera (LC-MSC) with 64 LEDs in eight different colors and a monochrome camera with a hardware cost of 340 euros.

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The prognosis for locked-in syndrome after acquired brainstem injury is unfavourable. However, partial recovery of motor function occurs in many patients and benefits from intensive rehabilitation. Here we evaluate two patient cases and results of a questionnaire among medical doctors specialised in rehabilitation.

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Crystal defects crucially influence the properties of crystalline materials and have been extensively studied. Even for the simplest type of defect-the point defect-however, basic properties such as their diffusive behavior, and their interactions, remain elusive on the atomic scale. Here, we demonstrate in situ control over the creation of isolated point defects in a three-dimensional (3D) colloidal crystal allowing insight on a single-particle level.

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Background: Patients with testicular cancer treated with chemotherapy have an increased risk of developing early cardiovascular events. Identification of patients with testicular cancer at a high risk of these events enables the development of preventative strategies. This study validates the vascular fingerprint tool to identify these patients.

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Controlled crystallization, melting and vitrification are important fundamental processes in nature and technology. However, the microscopic details of these fundamental phenomena still lack understanding, in particular how the cooling rate and presence of a wall influence the crystal nucleation and glass formation. Thermoresponsive microgels provide the possibility to study phase transitions at the single-particle level, owing to the ability to tune the particle size with temperature.

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Background: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare and potentially life-threatening mucocutaneous blistering diseases that clinically can resemble autoimmune bullous diseases. Moreover, it has been shown that autoantibodies against epidermal proteins are present in SJS/TEN.

Objectives: To establish the presence of antibodies against desmosomal and hemidesmosomal proteins in confirmed SJS/TEN patients.

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Circadian clock function declines with ageing, which can aggravate ageing-related diseases such as type 2 diabetes and neurodegenerative disorders. Understanding age-related changes in the circadian system at a systemic level can contribute to the development of strategies to promote healthy ageing. The goal of this study was to investigate the impact of ageing on 24-h rhythms in amine metabolites across four tissues in young (2 months of age) and old (22-25 months of age) mice using a targeted metabolomics approach.

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Based on an extensive model intercomparison, we assessed trends in biodiversity and ecosystem services from historical reconstructions and future scenarios of land-use and climate change. During the 20th century, biodiversity declined globally by 2 to 11%, as estimated by a range of indicators. Provisioning ecosystem services increased several fold, and regulating services decreased moderately.

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Hippocampal pyramidal neuron activity underlies episodic memory and spatial navigation. Although extensively studied in rodents, extremely little is known about human hippocampal pyramidal neurons, even though the human hippocampus underwent strong evolutionary reorganization and shows lower theta rhythm frequencies. To test whether biophysical properties of human Cornu Amonis subfield 1 (CA1) pyramidal neurons can explain observed rhythms, we map the morpho-electric properties of individual CA1 pyramidal neurons in human, non-pathological hippocampal slices from neurosurgery.

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Common dysglycemia measurements including fasting plasma glucose (FPG), oral glucose tolerance test (OGTT)-derived 2 h plasma glucose, and hemoglobin A1c (HbA1c) have limitations for children. Dynamic OGTT glucose and insulin responses may better reflect underlying physiology. This analysis assessed glucose and insulin curve shapes utilizing classifications-biphasic, monophasic, or monotonically increasing-and functional principal components (FPCs) to predict future dysglycemia.

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The chemical burden on the environment and human population is increasing. Consequently, regulatory risk assessment must keep pace to manage, reduce, and prevent adverse impacts on human and environmental health associated with hazardous chemicals. Surveillance of chemicals of known, emerging, or potential future concern, entering the environment-food-human continuum is needed to document the reality of risks posed by chemicals on ecosystem and human health from a one health perspective, feed into early warning systems and support public policies for exposure mitigation provisions and safe and sustainable by design strategies.

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Article Synopsis
  • Liquid chromatography-high-resolution mass spectrometry (LC-HRMS) allows for the detection of thousands of small molecules, but data alignment is challenging due to variability in the analytical process across different labs and instruments.
  • The upgraded metabCombiner tool facilitates the stepwise alignment of multiple untargeted LC-MS datasets, improving reproducibility in inter-laboratory studies by using a primary feature list to match compounds.
  • Additionally, batchCombine, a new application of metabCombiner, is introduced for aligning experiments with multiple batches, and both tools are accessible as an R package on GitHub and Bioconductor, as well as through a web-based R Shiny App.
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Solidification of complex liquids is pertinent to numerous natural and industrial processes. Here, we examine the freezing of a W/O/W double-emulsion, , water-in-oil compound droplets dispersed in water. We show that the solidification of such hierarchical emulsions can trigger a topological transition; for example, in our case, we observe the transition from the stable W/O/W state to a (frozen) O/W single-emulsion configuration.

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Metal halide perovskite nanostructures, characterized by their ionic nature, present a compelling avenue for the tunability of dimensions and band gaps through facile compositional transformations involving both cationic and anionic exchange reactions. While post-synthetic ion-exchange processes have been extensively explored in Pb-halide perovskite nanocrystals, the inherent instability of Sn has limited the exploration of such processes in Sn-halide perovskite nanostructures. In this study, we present a straightforward cation exchange process wherein 2D [R-NH]SnX Ruddlesden-Popper (RP) nanostructures with = 1 transition to 3D ASnX nanocrystals at room temperature with the addition of A-cation oleate.

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