357,471 research outputs found
Reaction of N,N-Dimethyltryptamine with Dichloromethane Under Common Experimental Conditions.
A large number of clinically used drugs and experimental pharmaceuticals possess the N,N-dimethyltryptamine (DMT) structural core. Previous reports have described the reaction of this motif with dichloromethane (DCM), a common laboratory solvent used during extraction and purification, leading to the formation of an undesired quaternary ammonium salt byproduct. However, the kinetics of this reaction under various conditions have not been thoroughly described. Here, we report a series of experiments designed to simulate the exposure of DMT to DCM that would take place during extraction from plant material, biphasic aqueous work-up, or column chromatography purification. We find that the quaternary ammonium salt byproduct forms at an exceedingly slow rate, only accumulates to a significant extent upon prolonged exposure of DMT to DCM, and is readily extracted into water. Our results suggest that DMT can be exposed to DCM under conditions where contact times are limited (<30 min) with minimal risk of degradation and that this byproduct is not observed following aqueous extraction. However, alternative solvents should be considered when the experimental conditions require longer contact times. Our work has important implications for preparing a wide-range of pharmaceuticals bearing the DMT structural motif in high yields and purities
Floquet engineering from long-range to short-range interactions
Quantum simulators based on atoms or molecules often have long-range
interactions due to dipolar or Coulomb interactions. We present a method based
on Floquet engineering to turn a long-range interaction into a short-range one.
By modulating a magnetic-field gradient with one or a few frequencies, one
reshapes the interaction profile, such that the system behaves as if it only
had nearest-neighbor interactions. Our approach works in both one and two
dimensions and for both spin-1/2 and spin-1 systems. It does not require
individual addressing, and is applicable to all experimental systems with
long-range interactions: trapped ions, polar molecules, Rydberg atoms,
nitrogen-vacancy centers, and cavity QED. Our approach allows one achieve a
short-range interaction without relying on Hubbard superexchange.Comment: 6 pages, 5 figure
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Off the record?: Arrestee concerns about the manipulation, modification, and misrepresentation of police body-worn camera footage
Police body-worn cameras (BWC) have become the latest technological device introduced to policing on a wave of panacean promises. Recent research has reported the perspectives of police officers, police management, and the general public, but there have been no studies examining the views of police arrestees. Remedying this significant omission, this article presents findings generated from interviews with 907 individuals shortly after their arrest. Overall, we report a strong in principle support for police body-worn cameras amongst this cohort, particularly if the cameras can be operated impartially. The findings are organised into a trilogy of prominent and interrelated concerns voiced by the police detainees, namely the potential for the manipulation, modification, and misrepresentation of events captured by police body-worn cameras. The findings are discussed in a broader context of the “new visibility” of police encounters and contribute much needed findings to understand the culturally specific ways in which different publics experience and respond to visual surveillance
Formation of Berthierine in the Martian Meteorite Nakhla by Replacement Of Aluminosilicate Glass [abstract]
No abstract available
An Evolutionary Game Theoretic Model of Rhino Horn Devaluation
Rhino populations are at a critical level due to the demand for rhino horn
and the subsequent poaching. Wildlife managers attempt to secure rhinos with
approaches to devalue the horn, the most common of which is dehorning. Game
theory has been used to examine the interaction of poachers and wildlife
managers where a manager can either `dehorn' their rhinos or leave the horn
attached and poachers may behave `selectively' or `indiscriminately'. The
approach described in this paper builds on this previous work and investigates
the interactions between the poachers. We build an evolutionary game theoretic
model and determine which strategy is preferred by a poacher in various
different populations of poachers. The purpose of this work is to discover
whether conditions which encourage the poachers to behave selectively exist,
that is, they only kill those rhinos with full horns.
The analytical results show that full devaluation of all rhinos will likely
lead to indiscriminate poaching. In turn it shows that devaluing of rhinos can
only be effective when implemented along with a strong disincentive framework.
This paper aims to contribute to the necessary research required for informed
discussion about the lively debate on legalising rhino horn trade
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