Purpose: To test the hypothesis that a physiological compensatory mechanism maintains respiratory gas exchange during normovolaemic haemodilution.
Methods: Pulmonary gas exchange capacity was evaluated in seven healthy subjects by measuring the lung diffusion of carbon monoxide (DLCO). During the measurement, various breath-holding times, inspiratory volumes, and sitting or supine positions, were randomly selected in an attempt to alter pulmonary capillary perfusion. KCO was calculated as the percentage of theoretical values of the ratio of DLCO by alveolar volume and normalized by sex, age, and height. Normovolaemic haemodilution (NH) was performed by bleeding an average blood volume of 1 L with simultaneous Dextran 60 replacement to obtain an haematocrit below 35%.
Results: After NH, haemoblogin concentration [Hb] decreased from 14.94 +/- 0.96 to 12.5 +/- 0.98 g.dl-1 (P < 0.001). KCO decreased (P < 0.02) but remained closely correlated to [Hb] at every lung volume (P < 0.02). Breathholding time and body position had no effect.
Conclusion: Moderate NH impairs pulmonary gas exchange capacity in awake, resting healthy subjects. There is no evidence of any compensatory mechanism since the KCO vs [Hb] relationship is unchanged.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1007/BF03017949 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Dissimilatory nitrate reduction pathways drive high nitrous oxide emissions and nitrogen retention under the flash drought in the largest freshwater lake in China.
Water Res
December 2024
Key Laboratory of Lake and Watershed Science for Water Security, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 211135, China; Sino-Danish Centre for Education and Research, University of Chinese Academy of Sciences, Beijing 100039, China; Poyang Lake Wetland Research Station, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Jiujiang 332899, China. Electronic address:
Flash drought (FD) events induced by climate change may disrupt the normal hydrological regimes of floodplain lakes and affect the plant-microbe mediated dissimilatory nitrate reduction (DNR), i.e., denitrification, anammox and dissimilatory nitrate reduction to ammonium (DNRA), thus having important consequences for nitrous oxide (NO) emissions and nitrogen (N) retention.
View Article and Find Full Text PDFAnomaly detection in multidimensional time series for water injection pump operations based on LSTMA-AE and mechanism constraints.
Sci Rep
January 2025
College of computer science and technology, China University of Petroleum (East China), No.66 Changjiang West Road, Huangdao, Qingdao, 266580, Shandong, China.
Addressing the issues of inadequate information exchange among subsequences in the operational time series of water injection pumps, leading to low accuracy and high false alarm rates in anomaly detection, this paper proposes a multidimensional time series anomaly detection method for water injection pump operations, leveraging Long Short-Term Memory Autoencoder augmented with Attention Mechanism (LSTMA-AE) and mechanistic constraints. The LSTMA-AE framework encompasses three primary modules: a Time Feature Extraction Module (Encoder), an Attention Layer, and a Data Reconstruction Module (Decoder). The Encoder captures temporal dependencies and features within the input sequences, mapping the input data into a higher-dimensional space.
View Article and Find Full Text PDFImpact of iron oxide nanoparticles on cadmium toxicity mitigation in Brassica napus.
Plant Physiol Biochem
January 2025
Institute of Crop Science, Ministry of Agriculture and Rural Affairs Key Laboratory of Spectroscopy Sensing, Zhejiang University, Hangzhou, 310058, China. Electronic address:
Cadmium (Cd) contamination greatly hinders plant productivity. Nanotechnology offers a promising solution for Cd phytotoxicity. The novelty of this study lies in the limited research on the effects of nanoiron (FeONPs) in regulating Cd toxicity in oilseed crops.
View Article and Find Full Text PDFHydraulic conductivity and photosynthetic capacity of seedlings of genotypes.
Photosynthetica
January 2025
Plant Physiology Sector, State University of Norte Fluminense, Center for Sciences and Agricultural Technologies (CCTA), Avenida Alberto Lamego, 2000, 28015-620, Campos dos Goytacazes, RJ, Brazil.
The aim was to investigate the morphological, photosynthetic, and hydraulic physiological characteristics of different genotypes of under controlled cultivation conditions. Growth, conductance, and hydraulic conductivity of the root system of 16 genotypes were evaluated in Experiment 1 (November 2013). In Experiment 2 (December 2014), in addition to the previous characteristics, gas exchange, photochemical efficiency, leaf water potential, and leaf hydraulic conductivity were investigated in five genotypes.
View Article and Find Full Text PDFImpact of exogenous rhamnolipids on plant photosynthesis and biochemical parameters under prolonged heat stress.
Photosynthetica
January 2025
University of Reims Champagne-Ardenne, INRAE, RIBP, USC 1488, 51100 Reims, France.
High temperatures severely affect plant growth and development leading to major yield losses. These temperatures are expected to increase further due to global warming, with longer and more frequent heat waves. Rhamnolipids (RLs) are known to protect several plants against various pathogens.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!