A MOF nanozyme-mediated acetylcholinesterase-free colorimetric strategy for direct detection of organophosphorus pesticides.

Although some simple and rapid colorimetric methods have been developed to detect organophosphorus pesticides (OPs), the difficult extraction and easy denaturation of acetylcholinesterase (AChE) are still drawbacks needing to be overcome. Here, we propose a MOF nanozyme-mediated AChE-free colorimetric strategy for the direct detection of OPs. In the presence of OPs (pirimiphos-methyl as a model), the intense blue of oxidized 3,3',5,5'-tetramethylbenzidine (TMB) becomes light due to the quenching effect of OPs towards hydroxyl radicals (˙OH) that are generated by the decomposition of H2O2 catalyzed by the Cu4Co6 ZIF nanozyme with excellent peroxidase (POD)-like activity. The developed colorimetric sensor exhibits assay performance and offers a universal and promising analysis strategy for detecting OPs in practical samples.

Functional Zonation Strategy of Heterodimer Nanozyme for Multiple Chemiluminescence Imaging Immunoassay.

Although nanozymes with intrinsic enzyme-like characteristics have aroused great interest in the biosensing field, the challenge is to keep high enzyme-like activity of the nanozyme after the modification of biomolecules onto nanozymes. Herein, a functional zonation strategy of a heterodimer nanozyme was proposed to tackle the challenge and further construct a multiple chemiluminescence (CL) imaging immunoassay. Here Fe3O4-Au as a heterodimer nanozyme model was divided into two zones, in which Fe3O4 nanoparticles (NPs) were regarded as a nanozyme zone and AuNPs were defined as an antibody immobilization zone. A signal amplification probe (Fe3O4-Au-Ab2) was prepared by modifying the secondary antibody (Ab2) on AuNPs of the Fe3O4-Au heterodimer owing to the Au-S bond. The exposed Fe3O4 of the Fe3O4-Au-Ab2 probe shows very high peroxidase-like activity and can efficiently catalyze H2O2-luminol to produce strong CL imaging signals for multiple antigens detection. Using chicken interleukin-4 (ChIL-4) and chicken gamma interferon (ChIFN-γ) as models, the proposed CL imaging immunoassay shows wide linear ranges (0.005-0.10 ng/mL for both ChIL-4 and ChIFN-γ) and low detection limits (0.58 pg/mL for ChIL-4, 0.47 pg/mL for ChIFN-γ) with the characteristics of high sensitivity, high specificity, and good stability. This work provides a promising functional zonation concept for nanozymes to construct new types of nanozyme probes for immunoassay of multiple biomolecules.

Facial attractiveness is more associated with individual warmth than with competence: Behavioral and neural evidence.

Individuals appear to infer others' psychological characteristics according to facial attractiveness and these psychological characteristics can be classified into two categories in social cognition, that is, warmth and competence. However, which category of psychological characteristic is more associated with face attractiveness and its neural mechanisms have not been explored. To address this, participants were asked to judge others' warmth and competence traits based on face attractiveness, while their brains were scanned using functional magnetic resonance imaging (fMRI). They also assessed the attractiveness of faces after scanning. Behavioral results showed that the correlation between face attractiveness and warmth ratings was significantly higher than that with competence ratings. fMRI results demonstrated that the dorsomedial prefrontal cortex (dmPFC), temporoparietal junction (TPJ), lateral prefrontal cortex, and lateral temporal lobe were more involved in the warmth task. Moreover, attractiveness ratings were negatively correlated with activation of the dmPFC and TPJ only in the warmth task. Furthermore, the attractiveness ratings were negatively correlated with the defined dmPFC, region related to attractiveness judgment, only in the warmth task. In conclusion, people are more inclined to infer others' warmth than competence characteristics from face attractiveness, that is, face attractiveness is more associated with warmth than with competence.

Neural processing of the physical attractiveness stereotype: Ugliness is bad vs. beauty is good.

The physical attractiveness stereotype (PAS) is characterized by the belief that beauty is good and ugliness is bad. Although the belief is not encouraged, people still express "beauty is good" explicitly. However, expressing that ugliness is bad is considered impolite in public. In this study, the neural underpinnings of PAS were investigated, particularly the comparison of the neural processing of ugliness is bad and beauty is good. During functional magnetic resonance imaging scanning, participants were asked to create trait-conformity judgments based on the facial attractiveness of the images. Our results showed that brain areas, including the fusiform, thalamus, anterior insula (AI), precuneus, inferior temporal gyrus, dorsal lateral prefrontal cortex (dlPFC), and dorsal medial prefrontal cortex (dmPFC) were involved in the processing of PAS. The left AI, left dlPFC, and right dmPFC showed stronger activation for ugliness is bad than for the converse. Moreover, we found a stronger connectivity between the left dlPFC and AI in terms of ugliness is bad than in the converse. Our study suggests that participants were unwilling to express the stereotype of ugliness is bad, and more mental resources were needed to control its expression than the expression of beauty is good.

Positive representation of relational self-esteem versus personal self-esteem in Chinese with interdependent self-construal.

Recent research has shown that relational self-esteem (RSE) carries important implications, especially in collectivistic cultures. In the present study, we aimed to investigate the neural mechanism underlying RSE and the behavioral and neural differences between RSE and personal self-esteem (PSE) in Chinese with interdependent self-construal. In Study 1, 581 participants completed a scale measuring RSE, the Rosenberg Personal Self-esteem Scale, and the Self-construal Scale. In Study 2, a functional magnetic resonance imaging (fMRI) scan was conducted with 42 participants while they evaluated whether they agreed with sentences concerning the relational self-worth, the personal self-worth and the semantics. Results of study 1 showed that individuals with higher interdependent self-construal were more likely to have higher RSE than PSE. The behavioral results of RSE and PSE in study 2 were consistent with the results of Study 1. Moreover, fMRI results showed that the activation of the ventral medial prefrontal cortex (vmPFC) was responsible for processing the positive representation of RSE versus PSE. More importantly, higher relational self-worth rating was related to more vmPFC activation among individuals with high interdependent self-construal. These results suggest that individuals with high interdependent self-construal have a more positive representation of RSE rather than PSE.

Brain regions in response to character feedback associated with the state self-esteem.

Research on the Sociometer theory of self-esteem have demonstrated that manipulations of interpersonal appraisal reliably influence an individual's state self-esteem and that state levels of self-esteem correlate very highly with perceived acceptance and rejection. However, how social feedback from different sources (e.g., appearance vs. character) affect the state self-esteem and its neural underpinnings have not been explored. To address this, participants underwent functional magnetic resonance imaging (fMRI) while viewing either appearance-related feedback words or character-related feedback words, and for each feedback word, they were asked to rate their state self-esteem. Results showed that participants reported a higher state self-esteem following character feedback, irrespective of valence, than that following appearance feedback. Moreover, fMRI results demonstrated that the left caudate tail was more activated in response to positive character feedback and the lateral prefrontal cortex (LPFC), dorsal anterior cingulate, posterior cingulate, and precuneus were more activated in response to negative character feedback than in response to appearance feedback. Moreover, activation of the left caudate tail was significantly correlated with the difference in participant's reported state self-esteem scores after receiving positive character feedback versus that after receiving positive appearance feedback. Further, activation of the LPFC was significantly correlated with a difference in participant's reported state self-esteem scores after receiving negative character feedback versus that after receiving negative appearance feedback. These findings suggest a reward-related mechanism when processing positive social feedback and a self-critical processing when processing the negative social feedback on an important aspect of self-concept (e.g., character-related).

Activations of the dorsolateral prefrontal cortex and thalamus during agentic self-evaluation are negatively associated with trait self-esteem.

Individual self-esteem is dominated more by agency than by communion. However, prior research has mainly focused on one's agentic/communal self-evaluation, while little is known about how one endorses others' agentic/communal evaluation of the self. The present study investigated the associations between trait self-esteem and fundamental dimensions of social cognition, i.e. agency vs. communion, during both self-evaluation and endorsement of others' evaluation of oneself. We also investigated the neural mechanisms underlying the relationship between trait self-esteem and agentic self-evaluation. Behavioral results revealed that self-esteem was positively correlated with the agentic ratings from self-evaluation and endorsement of others' evaluation of the self, and that the agentic self-evaluation was a significant full mediator between self-esteem and endorsement of others' agentic evaluation. Whole-brain regression analysis revealed that self-esteem was negatively correlated with right dorsolateral prefrontal and bilateral thalamic response to agentic self-evaluation. A possible interpretation is that low self-esteem people both hold a more self-critical attitude about the self and have less certainty or clarity of their self-concepts than high self-esteem people do. These findings have important implication for understanding the neural and cognitive mechanisms underlying self-esteem's effect on one's agentic self-evaluations.