Rapid confocal imaging of vesicle-to-sponge phase droplet transition in dilute dispersions of the C10E3 surfactant

Schröder, A.; Crassous, Jérôme J.; Marques, Carlos M.; Olsson, Ulf

doi:10.1038/s41598-019-38620-9

“…We hypothesize that the spherical assembly is a sponge‐like, continuous lipid phase [19] given that it had incorporated more MC540 than in a typical bilayer. Moreover, cryo‐TEM after 24 hours revealed the formation of a sponge‐like phase with interlamellar attachment points (Figure S9).…”

Section: Resultsmentioning

confidence: 99%

Acyl Phosphates as Chemically Fueled Building Blocks for Self‐Sustaining Protocells

Zozulia,

Kriebisch,

Kriebisch

et al. 2024

Angewandte Chemie

1

0

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Lipids spontaneously assemble into vesicle‐forming membranes. Such vesicles serve as compartments for even the simplest living systems. Vesicles have been extensively studied for constructing synthetic cells or as models for protocells—the cells hypothesized to have existed before life. These compartments exist almost always close to equilibrium. Life, however, exists out of equilibrium. In this work, we studied vesicle‐based compartments regulated by a non‐equilibrium chemical reaction network that converts activating agents. In this way, the compartments require a constant or periodic supply of activating agents to sustain themselves. Specifically, we use activating agents to condense carboxylates and phosphate esters into acyl phosphate‐based lipids that form vesicles. These vesicles can only be sustained when condensing agents are present; without them, they decay. We demonstrate that the chemical reaction network can operate on prebiotic activating agents, opening the door to prebiotically plausible, self‐sustainable protocells that compete for resources. In future work, such protocells should be endowed with a genotype, e.g., self‐replicating RNA structures, to alter the protocell's behavior. Such protocells could enable Darwinian evolution in a prebiotically plausible chemical system.

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Acyl Phosphates as Chemically Fueled Building Blocks for Self‐Sustaining Protocells

Zozulia,

Kriebisch,

Kriebisch

et al. 2024

Angew Chem Int Ed

1

0

View full text Add to dashboard Cite

Lipids spontaneously assemble into vesicle‐forming membranes. Such vesicles serve as compartments for even the simplest living systems. Vesicles have been extensively studied for constructing synthetic cells or as models for protocells—the cells hypothesized to have existed before life. These compartments exist almost always close to equilibrium. Life, however, exists out of equilibrium. In this work, we studied vesicle‐based compartments regulated by a non‐equilibrium chemical reaction network that converts activating agents. In this way, the compartments require a constant or periodic supply of activating agents to sustain themselves. Specifically, we use activating agents to condense carboxylates and phosphate esters into acyl phosphate‐based lipids that form vesicles. These vesicles can only be sustained when condensing agents are present; without them, they decay. We demonstrate that the chemical reaction network can operate on prebiotic activating agents, opening the door to prebiotically plausible, self‐sustainable protocells that compete for resources. In future work, such protocells should be endowed with a genotype, e.g., self‐replicating RNA structures, to alter the protocell's behavior. Such protocells could enable Darwinian evolution in a prebiotically plausible chemical system.

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A comparison of the metabolic effects of sustained strenuous activity in polar environments on men and women

Hattersley

¹

,

Wilson

²

,

Gifford

³

et al. 2020

Sci Rep

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This study investigates differences in pre-to post-expedition energy expenditure, substrate utilisation and body composition, between the all-male Spear17 (SP-17) and all-female Ice Maiden (IM) transantarctic expeditions (IM: N = 6, 61 days, 1700 km; SP-17: N = 5, 67 days, 1750 km). Energy expenditure and substrate utilisation were measured by a standardised 36 h calorimetry protocol; body composition was determined using air displacement plethysmography. Energy balance calculation were used to assess the physical challenge. There was difference in the daily energy expenditure (IM: 4,939 kcal day −1 ; SP-17: 6,461 kcal day −1 , p = 0.004); differences related to physical activity were small, but statistically significant (IM = 2,282 kcal day −1 ; SP-17 = 3,174 kcal day −1 ; p = 0.004). Bodyweight loss was modest (IM = 7.8%, SP-17 = 6.5%; p > 0.05) as was fat loss (IM = 30.4%, SP-17 = 40.4%; p > 0.05). Lean tissue weight change was statistically significant (IM = − 2.5%, SP-17 = + 1.0%; p = 0.05). No difference was found in resting or sleeping energy expenditure, normalised to lean tissue weight (p > 0.05); nor in energy expenditure when exercising at 80, 100 and 120 steps min −1 , normalised to body weight (p > 0.05). Similarly, no difference was found in the change in normalised substrate utilisation for any of the activities (p > 0.05). Analysis suggested that higher daily energy expenditures for the men in Spear-17 was the result of higher physical demands resulting in a reduced demand for energy to thermoregulate compared to the women in Ice Maiden. The lack of differences between men and women in the change in energy expenditure and substrate utilisation, suggests no sex difference in response to exposure to extreme environments. There is an increasing involvement of women in extreme activities often in adverse environmental conditions that are characterised by a deficit in Energy Availability (EA), the difference between the calorific intake and the energy expended. These activities, which include extreme sports 1 , expeditionary travel and military combat training 2 , have traditionally been undertaken by men with the result that the majority of the research looking at physiological adaptation and responses, particularly during expeditionary travel in polar regions and to altitude,

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Rapid confocal imaging of vesicle-to-sponge phase droplet transition in dilute dispersions of the C10E3 surfactant

Cited by 3 publications

References 35 publications

Acyl Phosphates as Chemically Fueled Building Blocks for Self‐Sustaining Protocells

Acyl Phosphates as Chemically Fueled Building Blocks for Self‐Sustaining Protocells

Acyl Phosphates as Chemically Fueled Building Blocks for Self‐Sustaining Protocells

A comparison of the metabolic effects of sustained strenuous activity in polar environments on men and women

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