Journal of the American Chemical SocietyDOI: 10.1021/jacs.0c01270
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Framework nucleic acid (FNA) nanocarriers controlled by a DNA‐computation circuit are designed for the delivery of molecular payloads in living cells in response to various stimuli and are used for mRNA imaging.
Abstract
Programming intelligent DNA nanocarriers for the targeted transport of molecular payloads in living cells has attracted extensive attention. In vivo activation of these nanocarriers usually relies on external light irradiation. An interest is emerging in the automatic recognition of intracellular surroundings by nanocarriers and their in situ activation under the control of programmed DNA‐computation circuits. Herein, we report the integration of DNA circuits with framework nucleic acid (FNA) nanocarriers that consist of a truncated square pyramid (TSP) cage and a built‐in duplex cargo containing an antisense strand of the target mRNA. An i‐motif and ATP aptamer embedded in the TSP are employed as logic‐controlling units to respond to H+ and ATP inside cellular compartments, triggering the release of the sensing element for fluorescent mRNA imaging. Logic‐controlled FNA devices could be used to target drug delivery, enabling precise disease treatment.
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Looking for eosin: In situ mapping of fugitive red lake pigments (eosin and carmine lakes) in a van Gogh painting was achieved with molecular fluorescence imaging spectroscopy. The high sensitivity of this method enabled lower concentrations of red lakes to be detected than by elemental X‐ray fluorescence imaging spectroscopy.
Abstract
Vincent van Gogh used fugitive red lake pigments that have faded in some paintings. Mapping their distribution is key to understanding how his paintings have changed with time. While red lake pigments can be identified from microsamples, in situ identification and mapping remain challenging. This paper explores the ability of molecular fluorescence imaging spectroscopy to identify and, more importantly, map residual non‐degraded red lakes. The high sensitivity of this method enabled identification of the emission spectra of eosin (tetrabromine fluorescein) lake mixed with lead or zinc white at lower concentrations than elemental X‐ray fluorescence (XRF) spectroscopy used on account of bromine. The molecular fluorescence mapping of residual eosin and two carmine red lakes in van Gogh's The Olive Orchard is demonstrated and compared with XRF imaging spectroscopy. The red lakes are consistent with the composition of paint tubes known to have been used by van Gogh.
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1.) What is the current scientific understanding of the mechanisms and short/long term effects of low-dose MDMA use?
2.) Has there been any research on potential interactions between prescription psychostimulants and low-dose MDMA use?
3.) What structures might undergo the most stress/damage? I've read research about how methamphetamine modulates mitochondria functioning, causing lactic acid build-ups. Is a similar effect to be expected from MDMA?
4.) What sort of difference in damage and side-effects can be expected between inhalation (low dose, rapid onset) and ingestion (high dose, long duration)?
Thanks for your (informed) answer, and please remember to keep replies free of medical advice or speculation! :)
I'm a student in the Faculty of Science, and I recently found out that one of my courses is technically part of the Faculty of Cellular/Molecular Medicine (CMM) and therefore bound by the CMM regulations (as opposed to the Faculty of Science regulations I received by email).
Is there anyone in the CMM Faculty who can let me know if they have received any regulations regarding exceptional considerations for final exams? The Faculty of Science regulations say that any final exam must either be a take-home assignment or an online exam of a normal duration. The professor for my CMM class told us we would have 2 hours to do our online exam, whereas the original duration of the final was supposed to be the standard three hours. I'm curious if there is a similar CMM regulation I could show our prof in order to extend the duration of the final to the full 3 hours.
Thank you!
Programming intelligent DNA nanocarriers for targeted transport of molecular payloads (e.g. antisense oligonucleotides) in living cells has attracted extensive attentions. In vivo activation of these nanocarriers usually relies on external light irradiation. An emerging interest is to enable them to automatically recognize the intracellular surroundings and thereby be activated in situ under the logic control of programmed DNA computation circuits. Towards this goal, here we integrate DNA computation circuits with framework nucleic acid (FNA) nanocarriers that consist of a truncated square pyramid (TSP) cage and a built‐in duplex cargo containing an antisense strand of the target mRNA. An i‐motif and ATP aptamer embedded in TSP are employed as logic controlling units to respond to endogenous proton and ATP inside subcellular compartments, triggering the release of the sensing element for fluorescent mRNA imaging. Given the abnormal levels of extra‐/intracellular pH and ATP in tumor tissues, our logic‐controlled FNA devices are of benefit to target drug delivery and precise disease treatment.
https://ift.tt/2tGLExC
