Abstract
Despite recently resurrected scientific interest in classical psychedelics, few studies have focused on potential harms associated with abuse of these substances. In particular, the link ...between psychedelic use and psychotic symptoms has been debated while no conclusive evidence has been presented. Here, we studied an adult population (n = 1032) with a special focus on young (18–35 years) and healthy individuals (n = 701) to evaluate the association of psychedelic drug use with schizotypy and evidence integration impairment typically observed in psychosis-spectrum disorders. Experimental behavioural testing was performed in a subsample of the subjects (n = 39). We observed higher schizotypy scores in psychedelic users in the total sample. However, the effect size was notably small and only marginally significant when considering young and healthy subjects (Cohen’s d = 0.13). Controlling for concomitant drug use, none of our analyses found significant associations between psychedelic use and schizotypal traits. Results from experimental testing showed that total exposure to psychedelics (frequency and temporal proximity of use) was associated with better evidence integration (Cohen’s d = 0.13) and a higher sensitivity of fear responses (Cohen’s d = 1.05) to the effects instructed knowledge in a reversal aversive learning task modelled computationally with skin conductance response and pupillometry. This effect was present even when controlling for demographics and concomitant drug use. On a group level, however, only difference in sensitivity of fear responses to instructed knowledge reached statistical significance. Taken together, our findings suggest that psychedelic drug use is only weakly associated with psychosis-like symptoms, which, in turn, is to a large extent explained by psychiatric comorbidities and use of other psychoactive substances. Our results also suggest that psychedelics may have an effect on flexibility of evidence integration and aversive learning processes, that may be linked to recently suggested therapeutic effects of psychedelic drugs in non-psychotic psychiatric populations.
We have studied the structure of epitaxial graphene obtained as a result of thermal desorption of the silicon carbide surface under conditions of vacuum synthesis and in Ar medium by reflection ...electron diffraction. As a result of the study, a significantly more uniform buffer layer coating of the SiC surface by epitaxial graphene has been found when forming in inert medium on the surface of 4
H
- and 6
H
-SiC(0001) polytypes compared with the synthesis of graphene in high vacuum. The quality of the coating has been shown to depend on the degree of perfection of the original single crystal.
Disulfide bonds formed by a pair of cysteine residues in the peptides’ backbone represent a certain problem for their sequencing by means of mass spectrometry. As a rule, in proteomics, disulfide ...bonds should be cleaved before the analysis followed by some sort of chemical derivatization. That step is time-consuming and may lead to losses of minor peptides of the analyzed mixtures due to incomplete reaction, adsorption on the walls of the vials, etc. Certain problems in the de novo top-down sequencing of amphibian skin peptides are caused by the C-terminal disulfide loop, called the Rana box. Its reduction with or without subsequent derivatization was considered to be an unavoidable step before mass spectrometry. In the present study, EThcD demonstrated its efficiency in sequencing intact disulfide-containing peptides without any preliminary derivatization. Applied to the secretion of three frog species, EThcD provided the full sequence inside the intramolecular disulfide cycle for all S–S-containing peptides found in the samples, with the only exception being diarginine species. Proteolytic fragments, which are shorter than the original peptides, were helpful in some cases. HCD should be mentioned as a complementary tool to the EThcD tool, being useful as a confirmation method for some sequence details.
The irreversible loss of lithium from the cathode material during the first cycles of rechargeable Li‐ion batteries notably reduces the overall cell capacity. Here, a new family of sacrificial ...cathode additives based on Li2O:Li2/3Mn1/3O5/6 composites synthesized by mechanochemical alloying is reported. These nanocomposites display record (but irreversible) capacities within the Li–Mn–O systems studied, of up to 1157 mAh g−1, which represents an increase of over 300% of the originally reported capacity in Li2/3Mn1/3O5/6 disordered rock salts. Such a high irreversible capacity is achieved by the reaction between Li2O and Li2/3Mn1/3O5/6 during the first charge, where electrochemically active Li2O acts as a Li+ donor. A 13% increase of the LiFePO4 and LiCoO2 first charge gravimetric capacities is demonstrated by the addition of only 2 wt% of the nanosized composite in the cathode mixture. This result shows the great potential of these newly discovered sacrificial additives to counteract initial losses of Li+ ions and improve battery performance.
A new family of sacrificial cathode additives based on Li2O:Li2/3Mn1/3O5/6 nanocomposites is reported with record first charge capacities of up to 1157 mAh g−1 achieved by the electrochemically activation of Li2O. With such a high prelithiation efficacy, the first charge capacity of LiFePO4 and LiCoO2 cathodes is improved by 13% with the addition of only 2 wt% of Li2O:Li2/3Mn1/3O5/6 nanocomposites.
Environmental exposure assessment is an important step in establishing a list of local priority pollutants and finding the sources of the threats for proposing appropriate protection measures. ...Exposome targeted and non-targeted analysis as well as suspect screening may be applied to reveal these pollutants. The non-targeted screening is a challenging task and requires the application of the most powerful analytical tools available, assuring wide analytical coverage, sensitivity, identification reliability, and quantitation.
Moscow, Russia, is the largest and most rapidly growing European city. That rapid growth is causing changes in the environment which require periodic clarification of the real environmental situation regarding the presence of the classic pollutants and possible new contaminants. Gas chromatography – high resolution time-of-flight mass spectrometry (GC-HR-TOFMS) with electron ionization (EI), positive chemical ionization (PCI), and electron capture negative ionization (ECNI) ion sources were used for the analysis of Moscow snow samples collected in the early spring of 2018 in nine different locations. Collection of snow samples represents an efficient approach for the estimation of long-term air pollution, due to accumulation and preservation of environmental contaminants by snow during winter period. The high separation power of GC, complementary ionization methods, high mass accuracy, and wide mass range of TOFMS allowed for the identification of several hundred organic compounds belonging to the various classes of pollutants, exposure to which could represent a danger to the health of the population. Although quantitative analysis was not a primary aim of the study, targeted analysis revealed that some priority pollutants exceeded the established safe levels. Thus, dibutylphthalate concentration was over 10-fold higher than its safe level (0.001 mg/L), while benzapyrene concentration exceeded Russian maximal permissible concentration value of 5 ng/L in three samples. The large amount of information generated during the combination of targeted and non-targeted analysis and screening samples for suspects makes it feasible to apply the big data analysis to observe the trends and tendencies in the pollution exposome across the city.
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•Complementary ionization tools increase environmental analysis' scope and reliability.•Over 500 environmental pollutants were identified in Moscow snow samples.•Electron capture negative ionization helps detecting halogenated and nitro compounds.•Accurate mass measurements increase reliability of the non-targeted screening.
We prove a new lower bound on the size of a code with complete feedback correcting a single error in a binary asymmetric channel. We also present an upper bound on the size of the code, which is ...close to the new lower bound.
A review is given on microwave discharges in liquid dielectrics—a relatively new direction in the physics and application of low-temperature plasma. The main types of experimental devices are ...described, and available information on the plasma parameters obtained by emission spectroscopy is presented. Examples of application of discharges in liquid dielectrics, such as solution of ecological problems and production of hydrogen, nanomaterials, and diamonds, are considered.
Research on brain-machine interfaces has been ongoing for at least a decade. During this period, simultaneous recordings of the extracellular electrical activity of hundreds of individual neurons ...have been used for direct, real-time control of various artificial devices. Brain-machine interfaces have also added greatly to our knowledge of the fundamental physiological principles governing the operation of large neural ensembles. Further understanding of these principles is likely to have a key role in the future development of neuroprosthetics for restoring mobility in severely paralysed patients.
The process of formation of cobalt silicides near the graphene-silicon carbide interface by intercalation of single-layer graphene grown on the 4
H
- and 6
H
-SiC(0001) polytypes with cobalt and ...silicon is studied. The experiments were carried out in situ in ultrahigh vacuum. The analysis of the samples is performed by high-energy-resolution photoelectron spectroscopy using synchrotron radiation, low-energy electron diffraction, and also Raman spectroscopy, atomic-force and kelvin-probe microscopies. The thicknesses of the deposited cobalt and silicon layers is varied to 2 nm, and the sample temperature, from room temperature to 1000°C. Co and Si atoms deposited on heated samples is found to penetrate under graphene and are localized between the buffer layer and the substrate, which leads to a transformation of the buffer layer into additional graphene layer. It is shown that the result of intercalation of the system with cobalt and silicon is the formation under two-layer graphene of a Co–Si solid solution and silicide CoSi coated by the surface Co
3
Si phase. It is shown that the thickness and the composition of the formed silicide films can be changed by varying the amount of the intercalated material and the order of their depositions.
A new technique for determining the point spread function, which is required for measuring the surface potential using Kelvin probe microscopy (KPM), is presented. The method involves using a silicon ...carbide substrate coated with single-layer and bilayer graphene as a test structure and obtaining KPM potential profiles in different directions on the surface. This makes it possible to determine the KPM point spread function, which can be used to perform deconvolution and accurately recover the surface potential.
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