Publications by authors named "J Mennigen"

Lanthanide-based nanoparticles (Ln-NPs) are highly valued for their unique optical and magnetic properties, making them useful in various scientific fields, including materials science and biomedicine. This study investigated the use of Gum Arabic (GA), a natural, non-toxic biopolymer, as capping agent for Ln-NPs to enhance their biocompatibility and chemical and colloidal stability. Specifically, Er/Yb co-doped NaGdF Ln-NPs were modified with GA, followed by their characterization with respect to upconversion properties and as well as toxicity.

View Article and Find Full Text PDF
Article Synopsis
  • Dysfunction in dopamine levels contributes to various psychiatric and neurodegenerative disorders, with the NR4A2 protein linked to conditions like Parkinson's disease and ADHD.
  • Researchers used zebrafish mutants to investigate the roles of two nr4a2 paralogs, nr4a2a and nr4a2b, finding distinct effects on dopamine neuron health and behavioral traits related to these conditions.
  • The loss of nr4a2a function mirrored Parkinsonian symptoms, while nr4a2b mutants had increased neurotrophic factors but also showed signs of mitochondrial dysfunction and oxidative stress.
View Article and Find Full Text PDF

Oxygen is essential to fuel aerobic metabolism. Some species evolved mechanisms to tolerate periods of severe hypoxia and even anoxia in their environment. Among them, goldfish (Carassius auratus) are unique, in that they do not enter a comatose state under severely hypoxic conditions.

View Article and Find Full Text PDF

High-throughput transcriptomics (HTTr) is increasingly applied to zebrafish embryos to survey the toxicological effects of environmental chemicals. Before the adoption of this approach in regulatory testing, it is essential to characterize background noise in order to guide experimental designs. We thus empirically quantified the HTTr false discovery rate (FDR) across different embryo pool sizes, sample sizes, and concentration groups for toxicology studies.

View Article and Find Full Text PDF

Using dominance hierarchies in juvenile rainbow trout (Oncorhynchus mykiss) as a model of chronic social stress in fish, we explored whether epigenetic transcriptional and post-transcriptional mechanisms are involved in the gene expression of corticotropin-releasing factor (crf) and 11β-hydroxysteroid dehydrogenase (11βhsd2), key factors involved in the regulation of the endocrine stress axis response. In juvenile rainbow trout pairs, subordinate individuals display sustained elevation of circulating cortisol concentrations. Cortisol production is controlled by the hypothalamic-pituitary-interrenal (HPI) axis in fish and initiated by CRF release from the preoptic area (POA).

View Article and Find Full Text PDF