There is clear evidence of placental leptin production, as shown recently in trophoblast cultures and by dual in vitro placenta perfusion (median production of 225 pg/min per g of tissue; 98.4% released into the maternal and 1.6% into the fetal circulation). However, the physiological impact for the mother and the fetus is unclear. The classical role of leptin is to provide information about energy stores to the central nervous system, and to reduce appetite if the energy stores are full. In pregnancy, maternal plasma leptin concentrations are elevated, and lack the well established correlation with body fat energy stores that is observed in non-pregnant women, indicating an alternative function for leptin during pregnancy and fetal development. Maternal and fetal plasma leptin levels are dysregulated in pathological conditions such as gestational diabetes, pre-eclampsia and intra-uterine growth retardation, representing an effect or a cause of disturbances in the feto/placento/maternal unit.
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http://dx.doi.org/10.1042/0300-5127:0290086 | DOI Listing |
Ecology
January 2025
Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland.
Temperate streams are subsidized by inputs of leaf litter peaking in fall. Yet, stream communities decompose dead leaves and integrate their energy into the aquatic food web throughout the whole year. Most studies investigating stream decomposition largely overlook long-term trajectories, which must be understood for an appropriate temporal upscaling of ecosystem processes.
View Article and Find Full Text PDFChem
November 2024
Department of Chemistry, Brandeis University, 415 South Street, Waltham, MA 02453, USA.
We introduce donor-acceptor substituted anthracenes as effective molecular solar thermal energy storage compounds that operate exclusively in the solid state. The donor-acceptor anthracenes undergo visible light-induced [4+4] cycloaddition reaction, producing metastable cycloadducts, dianthracenes with quaternary carbons, and storing photon energy. The triggered cycloreversion of dianthracenes to anthracenes discharges the stored energy as heat in the order of 100 kJ/mol (200 J/g).
View Article and Find Full Text PDFACS Omega
January 2025
The Innovation Base of Fine Mine Prospecting and Intelligent Monitoring Technology, Anhui University of Science and Technology, Huainan 232001, China.
Determining the starting time of the CO injection is the key factor affecting the effect of CO injection and CH production. This study uses the Panyidong mine in the Huainan mining area as an example. First, fully coupled mathematical models are established.
View Article and Find Full Text PDFSmall
January 2025
Department of Nanoscience, Joint School of Nanoscience and Nanoengineering, University of North Carolina at Greensboro, Greensboro, NC, 27401, USA.
The chemistry of the extracellular electron transfer (EET) process in microorganisms can be understood by interfacing them with abiotic materials that act as external redox mediators. These mediators capture and transfer extracellular electrons through redox reactions, bridging the microorganism and the electrode surface. Understanding this charge transfer process is essential for designing biocapacitors capable of modulating and storing charge signatures as capacitance at the electrode interface.
View Article and Find Full Text PDFJ Environ Manage
January 2025
Department of Soil, Water, and Ecosystem Sciences, University of Florida | IFAS, Gainesville, FL 32611, USA.
Stormwater ponds (SWPs) are an increasingly common management tool for flood control and water quality protection in urban areas. They are designed to buffer the impacts to downstream environments caused by altered hydrologic, chemical, biological, and ecological processes in developed watersheds. While small in size, they can have disproportionately large impacts on watersheds because they store, transform, and release inputs of carbon (C) and nutrients, mainly nitrogen (N) and phosphorus (P).
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