Structural Diversity of Protonated Citric Acid-Ammonia Clusters and Its Atmospheric Implication.

Various acid-base molecular clusters involving organic species can serve as precursors that play important roles in the formation of an atmospheric aerosol. Due to its structural flexibility and its ability to form multiple hydrogen bonds, citric acid acts as a key species in forming clusters that are critical in the nucleation of related aerosol precursors. Thus, it is provoking to characterize the structures of these clusters at the molecular level. In this paper, protonated citric acid-ammonia clusters of various sizes were generated by electrospray ionization and studied by tandem mass spectrometry. The structures of [(CA)2+NH4]1+ and [(CA)4+NH4]1+ were further characterized by the method of infrared photodissociation (IRPD) spectroscopy. Combined with theoretical calculations, it is found that the most stable structures of the dimeric and tetrameric isomers show the shapes of an ingot and a lantern, respectively. It has been revealed that the temperature has a great effect on the contributions of different isomers for both dimers and tetramers. The dominat isomers are found to have more open structures at higher temperatures, facilitating the growth of clusters through new hydrogen bonds.

Selective confinement of potassium, rubidium, or caesium ions in a non-covalent hydroxyproline octamer cage stabilized by cis-hydroxyl locks.

While numerous studies have focused on the impact of chirality on some magic amino acid clusters, this article investigates the effects of steric isomerization using 4-hydroxyproline octamers as a model system. Through mass spectrometry, infrared photodissociation spectroscopy, and theoretical calculation, it was demonstrated that the cis-4-hydroxy-L-proline octamer can selectively cage potassium, rubidium, or caesium ions through stable cis-hydroxyl locks, while the trans-form cannot. The results highlight the importance of hydroxyl group orientation in designing biocompatible membrane transporters with high ion-selectivity.

Effects of a virtual reality-based motivational reinforcement + desensitization intervention program on psychological craving and addiction memory in female MA-dependent young adults.

Objectives: The aim of this study was to explore the effects of a virtual reality (VR)-based motivational reinforcement + desensitization intervention program on psychological craving and addiction memory in female methamphetamine (MA)-dependent young adults. Methods: We recruited 60 female MA-dependent young adults in a compulsory isolation drug rehabilitation facility in Sichuan Province, and randomly assigned them to intervention (mean age = 23.24 ± 2.06) and control groups (mean age = 23.33 ± 2.09). The intervention group received a VR-based motivational enhancement + desensitization intervention (total of eight sessions over a 4-week period), while the control group received regular detoxification management during the same period. Assessments were conducted before, immediately after, and 1 month after the intervention, with a visual analogue scale (VAS) being used to assess subjective craving, electronic sphygmomanometer employed to measure physiological parameters, and the Addiction Memory Intensity Scale (AMIS) applied to assess addiction memory intensity. Results: Generalized estimating equation analysis showed significant main effects of group on changes in heart rate difference, systolic blood pressure difference, VAS and AMIS scores (all p < 0.01), and a significant time main effect on changes in diastolic blood pressure difference, VAS and AMIS scores (all p < 0.01), and a significant group × time interaction effect on changes in the difference values of three physiological parameters, VAS and AMIS scores (p < 0.01 or p < 0.05). After the intervention, the differences in three physiological parameters, and the VAS and AMIS scores, were significantly lower in the intervention than in the control group (all p < 0.05), and the difference between the two groups remained significant 1 month after the end of the intervention (both p < 0.01). VAS scores, heart rate difference, and diastolic blood pressure difference in the intervention group were significantly lower than baseline scores, both at the end of the intervention and 1 month thereafter (all p < 0.01); the systolic blood pressure difference in the intervention group was significantly lower at the end of the intervention than at baseline (p < 0.05); AMIS scores in the intervention group were significantly lower than the baseline scores 1 month after the end of the intervention (p < 0.01). Conclusion: Our VR-based motivational reinforcement + desensitization intervention program can effectively reduce psychological craving and physiological reactivity for drugs, and the intensity of addictive memories in female MA-dependent young adults, even after 1 month.

Structure and bonding properties of the platinum-mediated tetrametallic endohedral fullerene La3Pt@C98.

Nowadays, focus is on encapsulating a greater variety and amount of metal species into fullerene cages due to their diverse structures and fascinating properties. Nevertheless, the encapsulation of more positively charged metal atoms inside one cage means more Coulomb repulsion, which makes the formation of such endohedral metallofullerenes (EMFs) difficult. In general, non-metallic atoms such as N and O should be introduced as mediators for the formation of trimetallic or tetrametallic endohedral fullerenes. However, it is still unknown whether metal atoms can serve as mediators themselves to form such EMFs. In this paper, the endohedral tetrametallic fullerene La3Pt@C98 with the platinum atom as a metallic mediator is reported. The EMFs of La3Pt@C2n (2n = 98-300) were generated by the method of laser ablation in the gas phase and verified by mass spectrometry. Among them, the EMF of La3Pt@C98 was selected and studied by theoretical calculations. Results show that the two most stable isomers are La3Pt@C2(231010)-C98 and La3Pt@C1(231005)-C98. For both of them, the inner La3Pt metallic cluster appears in a pyramidal shape, different from the planar triangular pattern of La3N clusters previously reported. Further calculations prove the existence of encaged La-Pt bonds in the La3Pt cluster. It was also revealed that the negatively charged Pt atom is situated near the center of the four-center two-electron (4c-2e) metal bond with the highest occupancy number. The platinum-mediated cluster stabilizes the EMFs greatly, promising the possibility of synthesizing new species of Pt-containing EMFs.

Personality first in emotion: a deep neural network based on electroencephalogram channel attention for cross-subject emotion recognition.

In recent years, more and more researchers have focused on emotion recognition methods based on electroencephalogram (EEG) signals. However, most studies only consider the spatio-temporal characteristics of EEG and the modelling based on this feature, without considering personality factors, let alone studying the potential correlation between different subjects. Considering the particularity of emotions, different individuals may have different subjective responses to the same physical stimulus. Therefore, emotion recognition methods based on EEG signals should tend to be personalized. This paper models the personalized EEG emotion recognition from the macro and micro levels. At the macro level, we use personality characteristics to classify the individuals' personalities from the perspective of 'birds of a feather flock together'. At the micro level, we employ deep learning models to extract the spatio-temporal feature information of EEG. To evaluate the effectiveness of our method, we conduct an EEG emotion recognition experiment on the ASCERTAIN dataset. Our experimental results demonstrate that the recognition accuracy of our proposed method is 72.4% and 75.9% on valence and arousal, respectively, which is 10.2% and 9.1% higher than that of no consideration of personalization.