1. Peripheral lobules of term placentae obtained from healthy females at Caesarian section were perfused using separate maternal and fetal circulations for 6 h periods under either oxygenated or anoxic conditions. 2. Markers of physical integrity during setting-up and initial perfusion were establishment of dual perfusion within 25 min of placental delivery, pressure in the fetal capillary network less than 40 mmHg, leakage of perfusate from fetal to maternal compartments less than or equal to 2 ml/h, and overlap of maternal with fetal perfusion as indicated visually by appropriate blanching and verified by a fetal artery to vein oxygen gradient of greater than or equal to 90 mmHg. 3. Post-perfusion markers of metabolic viability were most reliably indicated by glucose consumption (oxygenated 7.8 +/- 1.5, anoxic 17.7 +/- 1.2 mmol/kg per h), lactate production (oxygenated 8.5 +/- 1.4, anoxic 33.9 +/- 2.5 mmol/kg per h) and human placental lactogen production (oxygenated 41.2 +/- 9.8, anoxic 12.2 +/- 3.4 mg/kg per h).
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http://dx.doi.org/10.1111/j.1440-1681.1988.tb01026.x | DOI Listing |
Langmuir
December 2024
Department of Civil Engineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh 208016, India.
Widespread geogenic uranium (U) contamination of Indian groundwaters is of serious concern; yet little is known of the dominant forms and release mechanisms of U in these aquifers. Interestingly, manganese (Mn)-rich aquifers, highly buffered by dissolved inorganic carbon (DIC) and saturated with rhodochrosite [MnCO], have shown low U (
Front Microbiol
December 2024
Institute of Microbiology, Leibniz University Hannover, Hannover, Germany.
Peatlands are invaluable but threatened ecosystems that store huge amounts of organic carbon globally and emit the greenhouse gasses carbon dioxide (CO) and methane (CH). Trophic interactions of microbial groups essential for methanogenesis are poorly understood in such systems, despite their importance. Thus, the present study aimed at unraveling trophic interactions between fermenters and methanogens in a nitrogen-limited, subarctic, pH-neutral fen.
View Article and Find Full Text PDFEur Heart J Acute Cardiovasc Care
December 2024
Department of Intensive Care, Hôpital Universitaire de Bruxelles (HUB), Université Libre de Bruxelles (ULB), Brussels, Belgium.
Huan Jing Ke Xue
January 2025
National Engineering Laboratory of Urban Sewage Advanced Treatment and Resource Utilization Technology, Faculty of Architecture, Civil and Transportation Engineering, Beijing University of Technology, Beijing 100124, China.
To achieve non-carbon dioxide greenhouse gas emission reduction and control in municipal wastewater treatment plants (WWTPs), this study conducted one-year long-term monitoring of nitrous oxide (NO) in the anaerobic-anoxic-aerobic (AO) process of a large-scale municipal wastewater treatment plant in Beijing. The experimental results showed that the anaerobic and anoxic zones of the AO process could effectively remove dissolved NO contained in the return sludge, while the aerobic zone was the main area for NO generation and emission, and its generation pathway may have been dominated by ammonia oxidizing bacteria (AOB) denitrification. A significant difference was observed between winter and summer NO production, and the difference in the average NO release flux was up to 7.
View Article and Find Full Text PDFSci Total Environ
December 2024
Aquatic Geomicrobiology, Institute of Biodiversity, Friedrich Schiller University, Jena, Germany; Cluster of Excellence Balance of the Microverse, Friedrich Schiller University Jena, Jena, Germany; German Center for Integrative Biodiversity Research (iDiv) Halle-Jena_Leipzig, Germany. Electronic address:
More than 90% of earth's microbial biomass resides in the continental subsurface, where sedimentary rocks provide the largest source of organic carbon (C). While many studies indicate microbial utilization of fossil C sources, the extent to which rock-organic C is driving microbial activities in aquifers remains largely unknown. Here we incubated oxic and anoxic groundwater with crushed carbonate rocks from the host aquifer and an outcrop rock of the unsaturated zone characterized by higher organic C content, and compared the natural abundance of radiocarbon (C) of available C pools and microbial biomarkers.
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