Modeling and experimental methods to predict oxygen distribution in bone defects following cell transplantation

Engineering next-generation oxygen-generating scaffolds to enhance bone regeneration

In bone, an adequate oxygen (O2) supply is crucial during development, homeostasis, and healing. Oxygen-generating scaffolds (OGS) have demonstrated significant potential to enhance bone regeneration. However, the complexity of O2 delivery and signaling in vivo makes it challenging to tailor the design of OGS to precisely meet this biological requirement. We review recent advances in OGS and analyze persisting engineering and translational hurdles. We also discuss the potential of computational and machine learning (ML) models to facilitate the integration of novel imaging data with biological readouts and advanced biomanufacturing technologies. By elucidating how to tackle current challenges using cutting-edge technologies, we provide insights for transitioning from traditional to next-generation OGS to improve bone regeneration in patients.

Oxidation of energy substrates in tissues of largemouth bass (Micropterus salmoides)

This study tested the hypothesis that amino acids are oxidized at higher rates than glucose and palmitate for ATP production in tissues of largemouth bass (LMB, a carnivorous fish). Slices (10 to 50 mg) of liver, proximal intestine, kidney, and skeletal muscle isolated from LMB were incubated at 26 °C for 2 h in oxygenated Krebs-Henseleit bicarbonate buffer (pH 7.4, with 5 mM D-glucose) containing either D-[U-¹⁴C]glucose, 2 mM L-alanine plus L-[U-¹⁴C]alanine, 2 mM L-aspartate plus L-[U-¹⁴C]aspartate, 2 mM L-glutamate plus L-[U-¹⁴C]glutamate, 2 mM L-glutamine plus L-[U-¹⁴C]glutamine, 2 mM L-leucine plus L-[U-¹⁴C]leucine, or 2 mM palmitate plus [U-¹⁴C]palmitate. In parallel experiments, tissues were incubated with a [U-¹⁴C]-labeled tracer and a mixture of unlabeled substrates [alanine, aspartate, glutamate, glutamine, leucine, and palmitate (2 mM each) plus 5 mM glucose]. ¹⁴CO₂ was collected to calculate the rates of substrate oxidation. In separate experiments, O₂ consumption by each tissue was measured in the presence of individual or a mixture of substrates. The activities of key metabolic enzymes were also measured. Results indicated that the liver and skeletal muscle had a limited ability to oxidize glucose and palmitate to CO₂ for ATP production in the presence of individual or a mixture of substrates due to low activities of carnitine palmitoyltransferase-I, hexokinase and pyruvate dehydrogenase. In the presence of individual substrates, each amino acid was actively oxidized by all the tissues. In the presence of a mixture of substrates, glutamine and glutamate were the major metabolic fuels in the proximal intestine and kidney, as glutamine for the liver and aspartate for skeletal muscle. All the tissues had high activities of glutaminase, glutamate dehydrogenase, and transaminases. At the same extracellular concentration of amino acids (2 mM) in a mixture of energy substrates, glutamine was the major metabolic fuel for the liver of the LMB, glutamine and glutamate for the proximal intestine and kidneys, and aspartate for the skeletal muscle. Glutamine plus glutamate plus aspartate generated 60-70% of ATP in LMB tissues.

Stability analysis of pine wilt disease model by periodic use of insecticides

This work is related to qualitative behaviour of an epidemic model of pine wilt disease. More precisely, we proved that the reproductive number has sharp threshold properties. It has been shown that how vector population can be reduced by the periodic use of insecticides. Numerical simulations show that epidemic level of infected vectors becomes independent of saturation level by including the transmission through mating.

Automated detection and analysis of depolarization events in human cardiomyocytes using MaDEC

Optical imaging-based methods for assessing the membrane electrophysiology of in vitro human cardiac cells allow for non-invasive temporal assessment of the effect of drugs and other stimuli. Automated methods for detecting and analyzing the depolarization events (DEs) in image-based data allow quantitative assessment of these different treatments. In this study, we use 2-photon microscopy of fluorescent voltage-sensitive dyes (VSDs) to capture the membrane voltage of actively beating human induced pluripotent stem cell-derived cardiomyocytes (hiPS-CMs). We built a custom and freely available Matlab software, called MaDEC, to detect, quantify, and compare DEs of hiPS-CMs treated with the β-adrenergic drugs, propranolol and isoproterenol. The efficacy of our software is quantified by comparing detection results against manual DE detection by expert analysts, and comparing DE analysis results to known drug-induced electrophysiological effects. The software accurately detected DEs with true positive rates of 98-100% and false positive rates of 1-2%, at signal-to-noise ratios (SNRs) of 5 and above. The MaDEC software was also able to distinguish control DEs from drug-treated DEs both immediately as well as 10min after drug administration.