Analytical chemistry
February 11, 2025
Yun Wu, Mei Li, Ruidong Liu et al.
6 citations
A new portable mass spectrometry device, PDRA-LTP-ITMS, can detect illicit drugs in saliva or urine within 5 seconds using only 10 microliters of sample. The method improves sensitivity up to 10-fold compared to some other techniques and achieves detection limits for MDMA, MDA, methamphetamine, amphetamine, ketamine, and cocaine ranging from 4.5 to 20 picograms per microliter in saliva, meeting Chinese national standards. The device's performance approaches that of a high-end laboratory mass spectrometer, offering a rapid on-site tool for identifying drug-impaired drivers.
Consciousness and cognition
June 1, 2026
Liang He, Zhige Zhang, Yuetan Wang et al.
The neural basis of conscious visual experience was investigated by combining magnetoencephalography with report and no-report masking paradigms. Early and sustained neural responses in occipital and temporal cortices began at about 60-70 milliseconds after a stimulus appeared, encoding stimulus presence and category regardless of whether participants reported what they saw. These posterior regions also showed enhanced alpha-band recurrent coupling for visible stimuli. Prefrontal cortex activity emerged only when explicit report was required, starting at about 100 milliseconds, and did not represent categorical content when reporting was absent. Long-range fronto-posterior connectivity increased selectively during report. The findings indicate that posterior cortical dynamics are sufficient to support perceptual awareness, while prefrontal cortex contributes to report-related access and global integration, supporting posterior-centered accounts of phenomenal consciousness.
Bioorganic & medicinal chemistry letters
October 1, 2010
David Y W Lee, Lu Yang, Wei Xu et al.
Salvinorin A, the main active ingredient of Salvia divinorum, is a potent and selective κ opioid receptor (KOPR) agonist. Researchers synthesized a series of C-2 halogenated analogs of salvinorin A as molecular probes to investigate the binding pocket at the C-2 position, particularly the effects of α versus β configuration. Binding and functional studies showed that β isomers generally bind better than α isomers, except for iodinated analogs. None of the C-2 halogenated analogs improved KOPR binding affinity compared to the parent compound. Functional assays characterized one analog, 6b, as a partial agonist with a maximum effect of 46% of the full agonist U50,488H at 250 nM. Affinity to the kappa receptor increased with atomic radius (I>Br>Cl>F), consistent with halogen bonding interactions.
Bioorganic & medicinal chemistry letters
March 1, 2009
Lu Yang, Wei Xu, Feng Chen et al.
Salvinorin A, the main active ingredient of Salvia divinorum, is a potent and selective kappa-opioid receptor agonist. A series of C-12 triazole analogs and an oxadiazole analog were synthesized and tested for binding affinity at kappa, mu, and delta opioid receptors. Surprisingly, all triazole analogs showed negligible binding affinity at opioid receptors, and the oxadiazole analog, previously reported as a mu and kappa opioid receptor antagonist, exhibited very low affinities and no antagonism in the binding assays. These results suggest that electronic factors affecting either the electron density of a hydrogen bond acceptor at C-12 or hydrophobic interactions between the C-12 moiety and the kappa-opioid receptor are critical for C-12 analog affinity.