Sep 18, 2020 02:20 AM
(This post was last modified: Sep 18, 2020 02:23 AM by C C.)
How the giant stinging tree of Australia can inflict months of agony (chemistry)
https://www.nature.com/articles/d41586-020-02668-9
RELEASE: A new type of peptide produces pain so intense that sometimes even morphine cannot quell it. The unrelenting pain from an Australian tree’s sting is caused by newly identified peptides resembling those in spider venoms.
The leaves and stems of the giant stinging tree (Dendrocnide excelsa) carry what looks like an inviting fuzz, but is actually numerous tiny needles. When a passer-by brushes against the tree, the needles can inject their skin with a venom causing intense pain that sometimes lasts months and resists even morphine. Various molecules have been proposed as the venom’s active component, but none adequately accounted for the severity and duration of the pain.
Irina Vetter and Thomas Durek at the University of Queensland in Brisbane and their colleagues ventured out to harvest leaves of wild D. excelsa and the closely related tree Dendrocnide moroides. Chemical analysis of the venom-injecting needles revealed a previously unknown family of peptides. The researchers named them gympietides after gympie-gympie, the trees’ name in the Indigenous Gubbi Gubbi language.
Further investigation showed that gympietides not only generate pain signals, but also suppress a mechanism that stops those signals. The authors, all of them Dendrocnide victims, hope their findings spur research to develop a gympietide antidote.
RELATED (toxic trees): Manchineel
Hybrid light-matter particles offer tantalising new way to control chemistry (chemistry, physics)
https://www.chemistryworld.com/news/hybr...43.article
EXCERPTS: For many, Thomas Ebbesen’s study might indeed sound like make-believe. His team showed it could change the rate and yield of a photoisomerisation reaction by – instead of carrying it out in a beaker – putting it in a small space between two mirrors. The space contained no chemical catalyst, nothing obvious that might make this possible. What the researchers did is tap into the power of the vacuum field, a weird quantum mechanical soup that surrounds everything.
‘2012 was an eye-opener for everyone,’ says Felipe Herrera who leads a molecular quantum technology group at the University of Santiago, Chile. ‘Nobody believed this, and people spent maybe two or three years until they could reproduce the results.’
Although vacuum-field catalysis is still in its infancy and doesn’t have any practical applications yet, it could bring catalyst-free catalysis, ultra-selective carbon dioxide reduction and new photosensitisers. It might become a powerful tool to steer chemical reactions akin to photocatalysis. ‘I think this field is going to have far-reaching implications,’ says Herrera.
‘It is the view of modern physics that there is no such thing as truly empty space,’ wrote physicist Brian Skinner [...] on his blog over a decade ago. Physicists discovered that the universe is filled with an energetic soup, boiling and bubbling with particles that appear as fast as they disappear. Although this almost sounds like a ridiculous return to the long-discarded aether theory, experimental results – like the Casimir effect – have long since established the vacuum field’s existence. [See Aether theories: qzuantum vacuum]
But what has been firmly in the realm of physics is now starting to interest chemists, who hope to one day catalyse reactions with this vacuum field. They do this by creating polaritons, hybrid particles that are part light, part matter. They form – even in the absence of light – when molecules strongly interact with the so-called virtual photons spontaneously thrown up by the vacuum field.
[...] Making molecules interact with the vacuum field is as easy as putting them in a cavity. Simply put, optical cavities consist of two mirrors facing each other and separated by only a few nanometres in some cases. Cavities are a major component of lasers where they form a resonator for light waves. But in the dark, they can be used to create polaritons. ‘Free space is infinite and vacuum field fluctuations are very tiny, which is why we don’t see strong coupling in free space,’ Herrera explains. ‘If you confine the field into tiny spaces, then these vacuum fluctuations are very large.’ (MORE - details)
https://www.youtube-nocookie.com/embed/sWmvZ0IGrsU
https://www.nature.com/articles/d41586-020-02668-9
RELEASE: A new type of peptide produces pain so intense that sometimes even morphine cannot quell it. The unrelenting pain from an Australian tree’s sting is caused by newly identified peptides resembling those in spider venoms.
The leaves and stems of the giant stinging tree (Dendrocnide excelsa) carry what looks like an inviting fuzz, but is actually numerous tiny needles. When a passer-by brushes against the tree, the needles can inject their skin with a venom causing intense pain that sometimes lasts months and resists even morphine. Various molecules have been proposed as the venom’s active component, but none adequately accounted for the severity and duration of the pain.
Irina Vetter and Thomas Durek at the University of Queensland in Brisbane and their colleagues ventured out to harvest leaves of wild D. excelsa and the closely related tree Dendrocnide moroides. Chemical analysis of the venom-injecting needles revealed a previously unknown family of peptides. The researchers named them gympietides after gympie-gympie, the trees’ name in the Indigenous Gubbi Gubbi language.
Further investigation showed that gympietides not only generate pain signals, but also suppress a mechanism that stops those signals. The authors, all of them Dendrocnide victims, hope their findings spur research to develop a gympietide antidote.
RELATED (toxic trees): Manchineel
Hybrid light-matter particles offer tantalising new way to control chemistry (chemistry, physics)
https://www.chemistryworld.com/news/hybr...43.article
EXCERPTS: For many, Thomas Ebbesen’s study might indeed sound like make-believe. His team showed it could change the rate and yield of a photoisomerisation reaction by – instead of carrying it out in a beaker – putting it in a small space between two mirrors. The space contained no chemical catalyst, nothing obvious that might make this possible. What the researchers did is tap into the power of the vacuum field, a weird quantum mechanical soup that surrounds everything.
‘2012 was an eye-opener for everyone,’ says Felipe Herrera who leads a molecular quantum technology group at the University of Santiago, Chile. ‘Nobody believed this, and people spent maybe two or three years until they could reproduce the results.’
Although vacuum-field catalysis is still in its infancy and doesn’t have any practical applications yet, it could bring catalyst-free catalysis, ultra-selective carbon dioxide reduction and new photosensitisers. It might become a powerful tool to steer chemical reactions akin to photocatalysis. ‘I think this field is going to have far-reaching implications,’ says Herrera.
‘It is the view of modern physics that there is no such thing as truly empty space,’ wrote physicist Brian Skinner [...] on his blog over a decade ago. Physicists discovered that the universe is filled with an energetic soup, boiling and bubbling with particles that appear as fast as they disappear. Although this almost sounds like a ridiculous return to the long-discarded aether theory, experimental results – like the Casimir effect – have long since established the vacuum field’s existence. [See Aether theories: qzuantum vacuum]
But what has been firmly in the realm of physics is now starting to interest chemists, who hope to one day catalyse reactions with this vacuum field. They do this by creating polaritons, hybrid particles that are part light, part matter. They form – even in the absence of light – when molecules strongly interact with the so-called virtual photons spontaneously thrown up by the vacuum field.
[...] Making molecules interact with the vacuum field is as easy as putting them in a cavity. Simply put, optical cavities consist of two mirrors facing each other and separated by only a few nanometres in some cases. Cavities are a major component of lasers where they form a resonator for light waves. But in the dark, they can be used to create polaritons. ‘Free space is infinite and vacuum field fluctuations are very tiny, which is why we don’t see strong coupling in free space,’ Herrera explains. ‘If you confine the field into tiny spaces, then these vacuum fluctuations are very large.’ (MORE - details)