Connection of social anxiety to impaired pattern of cognitive control and underlying motivational deficiencies: Evidence from event-related potentials.

Numerous studies have established a correlation between social anxiety and poor cognitive control. However, little is known about the cognitive control pattern of individuals with high social anxiety (HSAs) and the underlying mechanisms. Based on the Dual Mechanisms of Control framework and the Expected Value of Control theory, this study explored whether HSAs have an impaired cognitive control pattern (Experiment 1) and whether motivational deficiencies underlie the impaired control pattern (Experiment 2). In Experiment 1, 21 individuals with low social anxiety (LSAs) and 21 HSAs completed an AX-Continuous Performance Task. Results showed that HSAs had a smaller P3b amplitude than LSAs, indicating their weakened proactive control in the cue processing stage, but a larger contingent negative variation (CNV) on cue B as compensation for the negative effects of anxiety in the response preparation stage. No group difference was found in N2 and P3a amplitude on probes, suggesting that reactive control in HSAs was not affected compared to LSAs. In Experiment 2, 21 LSAs and 21 HSAs completed a cued-flanker task, where the likelihood of proactive control engagement was manipulated. The results revealed that HSAs exhibited motivation deficiencies in engaging in proactive control, as evidenced by P3b, CNV amplitude, and response times. These findings shed light on the impaired cognitive control pattern of HSAs and suggest that motivational deficiencies may be the crucial underlying factor.

Obsessive-compulsive disorder in Chinese methamphetamine patients: Prevalence, demographics, and clinical characteristics.

BACKGROUND AND OBJECTIVES: Methamphetamine (MA) is one of the most common addictive substances and has become the second most commonly used drug worldwide. Obsessive-compulsive disorder (OCD) has been shown to influence the effectiveness of addiction treatment, and there may be overlapping neurobiological mechanisms between OCD and addiction. The aim of this study was to investigate the prevalence and clinical correlates of OCD among MA patients. METHODS: A total of 457 MA patients were recruited, and clinical and demographic data were collected. The Yale-Brown Obsessive-Compulsive Scale was utilized for OCD symptoms, and the Obsessive-Compulsive Drug Use Scale was used for MA craving. RESULTS: The prevalence of OCD among MA patients was 7.7%. Compared to those patients without OCD, patients with OCD had a longer length of abstinence and higher OCDUS frequency of craving subscale and total scores. Multiple regression showed that longer length of abstinence and higher MA carving were independently associated with OCD in MA patients. DISCUSSION AND CONCLUSIONS: Chinese Han MA patients have a high prevalence of OCD. Some clinical parameters may be associated with OCD in MA patients. SCIENTIFIC SIGNIFICANCE: This is the first study to examine the prevalence, sociodemographic and clinical correlates of OCD in MA patients in a Chinese Han population.

Expectation modulates the preferential processing of task-irrelevant fear in the attentional blink: evidence from event-related potentials.

BACKGROUND: Reporting the second of the two targets is impaired when it occurs 200-500 ms after the first, the phenomenon in the study of consciousness is the attentional blink (AB). In the AB task, both the emotional salience and the expectation of the second target increase the likelihood of that target being consciously reported. Yet, little is known about how expectations modulate the prioritized processing of affective stimuli. We examined the role of expecting fearful expression when processing fear in an AB task. Participants were presented with an AB task where the 2nd target (T2) is either a fearful face or a neutral face, and had to report the target's gender. The frequency of fearful to neutral faces on a given block was manipulated, such that participants could either expect more or less fearful faces. RESULTS: In the Experiment 1, we found that fearful faces were more likely to be recognized than neutral faces during the blink period (lag3) when participants were not expecting a fearful face (low fear-expectation); however, high fear-expectation increased the discrimination of fearful T2 than neutral T2 outside the blink period (lag8). In the Experiment 2, we assessed ERP brain activity in response to perceived T2 during the blink period. The results revealed that fearful faces elicited larger P300 amplitudes compared to neutral faces, but only in the low fear-expectation condition, suggesting that expecting a fearful expression can suppress the processing of task-irrelevant facial expression and unexpected fearful expression can break through this suppression. Fearful T2 elicited larger vertex positive potential (VPP) amplitudes than neutral T2, and this affective effect was independent of fear-expectation. Since no effect of expectation was found on the VPP amplitude while P300 exhibited significant interaction between expectation and expression, this suggests that expectations modulate emotional processing at a later stage, after the fearful face has been differentially processed. CONCLUSIONS: These results provided clear evidence for the contribution of the expectation to the prioritized processing of second affective stimuli in the AB.

Interaction between color and attentional level in children's conflict control.

Perception of color can affect cognition and behavior in humans. Although there has been increasing interest in the effect of red on cognitive performance in adults, little is known about how red affects children's cognition. The current study investigates the role of attention in the effect of red on conflict control among children aged 9-13 years, by the manipulation of selective attention (color-attended vs. color-unattended) to each color (red, green and grey) during the Flanker task with a blocked design. In the color-unattended block, participants judged the orientation of the central arrow (target) regardless of its color. In the color-attended block, participants selectively responded to the target with a pre-cued color before each block. The results showed that participants responded to the red targets faster than the grey targets for the congruent trials in the color-unattended block; however, they responded to the red and green targets slower than the grey targets for the incongruent trials in the color-attended block. These findings suggested that red also affected children's conflict control and the effect was modulated by the attention level of color.

The interaction between reward and the task-irrelevant emotional context in memory.

Reward improves task performance while the emotional contexts irrelevant to the task impair task performance. An interaction between reward and the task-irrelevant emotional context has been discovered by some studies using perceptual tasks. However, it is unclear that how memory performance would be affected by both variables. This study aimed to answer this question and explore the role of arousal induced by emotional stimuli, to which was seldomly paid attention by previous studies. We conducted two experiments with the study-test paradigm. The first difference between the experiments was the way that the emotional stimuli were presented. They were presented with the words (Experiment 1) or separately (Experiment 2). The second difference was that the manipulation of the emotional arousal was phasic (Experiment 1) or tonic (Experiment 2). Both experiments showed that the reward effect was greater in emotional context compared to the neutral context, which is not only due to the poorer memory of no reward-associated words but also the better memory of reward-associated words in emotional contexts especially in negative one. These results supported the view that emotional arousal enhanced the memory of high priority stimuli (reward-associated words) and impaired the memory of low priority stimuli (no reward-associated words).

The role of emotion arousal in the retrieval practice effect.

Many studies have shown that practicing retrieval produces better memory retention compared to restudy. Though previous literature has provided valuable insights about the retrieval practice effect, it is still unclear how emotion arousal influences the retrieval practice effect, and whether the effect would be manifested in recollection or familiarity processes. To answer these questions, in the current study, negative and neutral words were used as stimuli and participants were asked to perform a recognition test or restudy the words after initial study. At the end of the experiment, a final recognition test with involving the remember-know paradigm was shown. Behavioral data were collected with EEG recorded throughout the experiment. The behavioral retrieval practice effect was only found for the neutral but not the negative words. Consistently, significant ERP differences between the restudy and retrieval practice conditions were only found for neutral, but not negative items, which was a component from 700 to 900 ms at left-posterior electrode cluster. Moreover, we found that the effects of emotion arousal on the retrieval practice effect were mainly reflected in the recollection process. These findings provide behavioral and neural evidence that emotion arousal can influence the retrieval practice effect.

[Molecular mechanism of apoptosis of breast cancer SKBR-3 cells induced by cryptanshinone via G protein coupled estrogen receptor( GPER) mediated pathway].

The study aimed to illuminate the role of G protein coupled estrogen receptor( GPER) and its mediated PI3 K/AKT signaling pathway in cryptotanshinone( CPT) induced apoptosis of breast cancer SKBR-3 cells,which is GPER positive and ER negative.The apoptosis rate of SKBR-3 cells was tested by Annexin V-FITC/PI staining and apoptosis effector caspase-3 was determined by Western blot. The key proteins in PI3 K/AKT signaling pathway mediated by GPER were detected by Western blot and immunofluorescence technique. Meanwhile,the agonist G1 and antagonist G15 of GPER and antagonist LY294002 of PI3 K were employed in the test to further clarify the effect of GPER and PI3 K/AKT pathway. The results indicated that the apoptosis rate was increased from 4. 7% to46. 1% and 69. 0% after treatment with 0,5,10 µmol·L~(-1) CPT for 48 h( P<0. 01). The expression of PI3 K,AKT and p-AKT were inhibited( P<0. 05 or P<0. 01),while caspase-3 level increased obviously after treatment with CPT( P<0. 01). Importantly,inhibitory effect of PI3 K/AKT signaling pathway by CPT was further enhanced by G1 and attenuated by G15. LY294002 also induced a further inhibition of expression of AKT and p-AKT. The mean fluorescence intensity of AKT and p-AKT could be decreased by CPT. Furthermore,CPT could downregulate GPER expression in SKBR-3 cells( P<0. 01),which could be inhibited by G1 and enhanced by G15.In conclusion,CPT could induce the apoptosis of ER negative and GPER positive breast cancer SKBR-3 cells and the molecular mechanism is related to its regulatory effect of GPER and its mediated PI3 K/AKT signaling pathway.

Correction to: Spectrum of PAH gene variants among a population of Han Chinese patients with phenylketonuria from northern China.

Following publication of the original article [1], the authors reported an error in Table 3 on page 4. Variant No. 18 should be " p.Ser339Phe c.1016C>T " (as given in Number 117 of Additional file 2).

The effect of attentional bias modification on eating behavior among women craving high-calorie food.

In individuals with healthy weight and overweight, the level of food cravings experienced is closely related to the individual's attentional bias to food cues. Furthermore, an attentional bias toward food cues, especially high-calorie food cues, is often accompanied by poor eating habits, overweight or obesity, eating disorders, and other problems. Therefore, this study aimed to explore the effect of attentional bias modification on the eating behavior of women craving high-calorie food. Sixty-five female college students with a high level of craving for high-calorie foods were randomly assigned to a training group (attended to images of low-calorie food) and a control group (attended equally to images of high- and low-calorie food). An attentional re-training paradigm was used in the training session to modify the participants' attentional bias to these food cues. Compared to the control group, attentional bias to high-calorie food cues in the training group was significantly reduced after training (p < 0.05). The training group consumed less high-calorie food and more low-calorie food than the control group (p < 0.05) in a post-training taste test. However, there was no significant difference between the groups in their level of food cravings (p > 0.05). These findings suggest that attentional bias modification training is a promising brief intervention to improve eating behavior and develop healthy eating habits.

Microcapsules biologically prepared using Perilla frutescens (L.) Britt. essential oil and their use for extension of fruit shelf life.

BACKGROUND: Perilla essential oil (EO) possesses high antioxidant, antimicrobial and insecticidal activities, and has proven to be more reliable than chemically synthesized food preservatives. Nevertheless, EOs have disadvantages of facile photo-degradation and oxidation, which limit their use in agriculture and food industries. Microencapsulation technology that generates a polymeric coating surrounding EOs could overcome these disadvantages. RESULTS: The EO concentration had a significant effect on encapsulation efficiency (EE) and loading capacity (LC). The best encapsulation conditions were obtained with 2% v/v EO, for which EE and LC were 57% and 36%, respectively. EO-loaded microspheres exhibited a crimped surface with phanic lumps by scanning electron microscopy. Thermal stability experiments revealed droplets that began to decompose sharply at 108 °C, with a 61% weight, loss, which was much lower than EOs of 98%. EO-loaded microcapsules demonstrated good antibacterial activity. Strawberry preservation studies showed that EO-loaded microcapsules could significantly inhibit strawberry decay, maintain the quality of strawberries and prolong shelf life. CONCLUSION: Perilla EO-loaded microcapsules were successfully prepared by ionic gelation and were effective at inhibiting several bacterial strains. EO-alginate microcapsules could effectively delay the volatilization of EO. Perilla EO-loaded microcapsules therefore have potential for use as an antimicrobial and preservative agent in the food industry. © 2017 Society of Chemical Industry.

Spectrum of PAH gene variants among a population of Han Chinese patients with phenylketonuria from northern China.

BACKGROUND: Phenylketonuria (PKU), which primarily results from a deficiency of phenylalanine hydroxylase (PAH), is one of the most common inherited inborn errors of metabolism that impairs postnatal cognitive development. The incidence of various PAH variations differs by race and ethnicity. The aim of the present study was to characterize the PAH gene variants of a Han population from Northern China. METHODS: In total, 655 PKU patients and their families were recruited for this study; each proband was diagnosed both clinically and biochemically with phenylketonuria. Subjects were sequentially screened for single-base variants and exon deletions or duplications within PAH via direct Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA). RESULTS: A spectrum of 174 distinct PAH variants was identified: 152 previously documented variants and 22 novel variants. While single-base variants were distributed throughout the 13 exons, they were particularly concentrated in exons 7 (33.3%), 11 (14.2%), 6 (13.2%), 12 (11.0%), 3 (10.4%), and 5 (4.4%). The predominant variant was p.Arg243Gln (17.7%), followed by Ex6-96A > G (8.3%), p.Val399 = (6.4%), p.Arg53His (4.7%), p.Tyr356* (4.7%), p.Arg241Cys (4.6%), p.Arg413Pro (4.6%), p.Arg111* (4.4%), and c.442-1G > A (3.4%). Notably, two patients were also identified as carrying de novo variants. CONCLUSION: The composition of PAH gene variants in this Han population from Northern China was distinct from those of other ethnic groups. As such, the construction of a PAH gene variant database for Northern China is necessary to lay a foundation for genetic-based diagnoses, prenatal diagnoses, and population screening.

Silencing of astrocyte elevated gene-1 inhibits proliferation and migration of melanoma cells and induces apoptosis.

Melanoma is an aggressive skin malignancy with a high mortality. Astrocyte elevated gene-1 (AEG-1), a downstream target of Ras and c-Myc, has been implicated in the development of multiple tumours, but its role in melanoma remains unclear. In the present study, the role of AEG-1 in melanoma was explored through AEG-1 silencing. Our results showed that silencing AEG-1 inhibited the proliferation of melanoma cells, induced cell cycle arrest, and reduced levels of cyclin A, cyclin B, cyclin D1, cyclin E, and cyclin-dependent kinase 2. AEG-1silencing also induced apoptosis in melanoma cells and altered the levels of cleaved caspase-3, B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X protein. Moreover, silencing AEG-1 suppressed the migration and invasion of melanoma cells, reduced the expressions and activities of matrix metallopeptidase (MMP)-2 and MMP-9, and inhibited the activation of the Wnt/ß-catenin signalling pathway in melanoma cells. Furthermore, in vivo experiments revealed that AEG-1 silencing inhibited the growth of melanoma xenografts in nude mice. In summary, our study demonstrates an oncogenic role of AEG-1 in melanoma and suggests that AEG-1 may serve as a potential therapeutic target in the treatment of melanoma.

Emotion beliefs, emotion regulation strategies, and test anxiety of Chinese adolescents in grade 8: Evidence from physiological recordings during an exam.

Controllability beliefs and goodness beliefs about emotion are two fundamental emotion beliefs. The present study considered both controllability beliefs and goodness beliefs to examine whether and how the emotion beliefs of adolescents influence their test anxiety. Besides self-reported test anxiety (sr-TA), the present study measured heart rate (HR) and galvanic skin response (GSR) using custom-designed wristbands during an exam as indicators of state test anxiety. The GSR was further decomposed into the tonic skin conductance level and the transient skin conductance response. The results revealed that, after controlling the goodness beliefs about anxiety, the controllability beliefs about emotion were negatively related to sr-TA. This relationship was mediated by suppression. The controllability beliefs about emotion were directly related to the integration of transient skin conductance responses of 5 min before the exam. They were also indirectly related to the integration of transient skin conductance responses of the exam period, whether including the 5 min before the exam or not, and HR during certain periods through suppression. Therefore, adolescents' controllability beliefs about emotion may have important implications for their test anxiety.

[Effects of beta-amyloid and apolipoprotein E4 on hippocampal choline acetyl transferase in rats].

OBJECTIVE: To investigate the effects of beta-amyloid (Aß) and apolipoprotein E4(apoE4) on choline acetyl transferase (ChAT) in hippocampus and to explore possible the synergistic effect of both Aß and apoE4. METHODS: Male Wistar rats were divided into four groups: control group, Aß group, apoE4 group and Aß + apoE4 group. Rats in different group received injection of normal saline, Aß1-40, apoE4 and Aß1-40 + apoE4, respectively, into bilateral hippocampus CA1 regions under the control of a brain stereotaxic apparatus. The learning-memory ability with the escape latency and the times of passing platform and the expression of ChAT in hippocampus CA1 regions were documented. RESULTS: The escape latency at fifth day and the times of passing platform and ChAT mRNA PU values were obtained for the control group (10.75 s ± 2.44 s, 4.13 ± 0.64, and 28.90 ± 4.43), apoE4 group (23.88 s ± 4.32 s, 2.38 ± 0.52, and 20.85 ± 3.98), Aß group (43.50 s ± 9.78 s, 1.38 ± 0.52, and 16.96 ± 2.53), and Aß + apoE4 group (70.63 s ± 10.04 s, 0.75 ± 0.71, and 13.01 ± 2.21). Through 5 days of training all animals acquired learning-memory ability with the gradually shortened escape latency, although injection of Aß1-40 and apoE4 all induced learning-memory damage, due to a significantly prolonged the escape latency at fifth day (P < 0.01) and markedly decreased the times of passing platform (P < 0.01) in both Aß and apoE4 group than in control group. An interaction between Aß and apoE4 also was observed, with further prolonged escape latency(P < 0.01). ChAT mRNA PU values were significantly lower in the Aß group and apoE4 group than in the control group (P < 0.01). Aß and apoE4 demonstrated interaction in lowering ChAT mRNA level(P < 0.05). CONCLUSIONS: Both Aß and apoE4 induce an injury to hippocampal cholinergic system and its learning-memory ability, in which Aß and apoE4 have a synergistic effect in the initiation of such injury.

Reward association impairs recognition of incidentally encoded negative information: Electrophysiological evidence.

Previous studies investigating the effect of reward on emotional episodic memory have produced inconsistent results. In this study, through two experiments using event-related potentials (ERPs), we investigated the effect of reward association on the encoding and retrieval of incidentally encoded emotional information, and examined whether this effect changes over time. Participants in the two experiments were asked to discriminate the emotional valence of color images under reward or no-reward condition and incidentally encode them. Immediate (in Experiment 1) or 24-hour delayed (in Experiment 2) recognition after encoding was tested. In Experiments 1 and 2, reward (relative to no-reward) significantly improved the recognition of positive and neutral items, but significantly reduced the recognition of negative items. During encoding, the significant ERP reward effects (significantly more positive ERP amplitude for rewarded items than for non-rewarded ones) for positive and neutral images were widely distributed from 200 to 1500 ms after image onset, while those for negative stimuli occurred mainly from 200 to 500 ms. During retrieval, the significant ERP reward effects for positive and neutral items occurred in the two experiments, but the reversed ERP reward effects for negative items were found only in Experiment 1. The results of the present study suggest that reward association affects the encoding and retrieval of emotional images by enhancing memory processing efficiency of positive and neutral items, while impairing recognition of negative items, thus yielding a robust and sustained modulation over frontal/frontocentral or centroparietal/parietal areas where mechanisms of reward and emotion processing operate in conjunction.

How do fundamental emotion beliefs affect the rapid emotional processing? An ERP study.

Beliefs about whether emotions are good or bad, controllable or uncontrollable are two fundamental emotion beliefs. Studies have confirmed the link between the two beliefs and emotional responses, but how emotion beliefs affect the process from emotional stimulus perception to emotion generation and automatic regulation is unclear. Answering this question helps to understand the role of emotion beliefs in emotional dysfunction and dysregulation and can provide a basis for effective emotion regulation. Therefore, the current study used event-related potential (ERP) measures to examine the time course and neural mechanisms by which emotional beliefs influence the processing of emotional pictures. One hundred participants were divided into four groups (25 per group) according to controllable or uncontrollable beliefs about emotions and good or bad beliefs about negative emotions, and viewed emotional negative and neutral pictures. Results showed that P2 was more positive in participants with emotion controllable vs. uncontrollable belief. The early posterior negativity (EPN) was more negative for unpleasant than neutral images in participants with emotion good and controllable beliefs as well as with bad and uncontrollable beliefs. On late positive potential (LPP), middle LPP (500-1000ms) was more positive in emotion good vs. bad belief holders and the late LPP (1000-2000 ms) was more positive for negative than neutral images in emotion uncontrollable belief holders. The findings suggest that fundamental emotion beliefs can affect individuals' early attention and late meaning evaluation towards unpleasant stimuli. Furthermore, they provide insight into altered beliefs about emotion in people with emotion dysfunction or dysregulation.

Can mental imagery boost the effect of the positive cognitive bias modification of interpretation (CBM-I) on interpretation bias and memory bias?

BACKGROUND AND OBJECTIVES: Cognitive bias modification of interpretation (CBM-I) has been widely used and yielded mixed results. This experiment explored the unique role of mental imagery in positive CBM-I. METHODS: 60 participants (M = 23.13, SD = 1.04) were randomly assigned to a imagery-based positive CBM-I group (imagery group) and a conventional verbal-based positive CBM-I group (control group). The imagery group received additional practice in generating mental imagery and were instructed to fully focus on the imagery during the formal training. The dependent variables included interpretation bias (probe latencies and similarity ratings for recognition task), memory bias, and intrusive memory. RESULTS: (1) For the positive probe scenario, the reaction time of the two groups was shorter in the posterior five blocks than the anterior five blocks. However, the difference in latency between pre- and post- training for the imagery group was larger than that of the control group; (2) For the recognition task, the positive target statement score was significantly higher, while the negative one was significantly lower for the imagery group than that of the control group (3) The imagery group (vs. control); showed more beneficial effects on memory bias. LIMITATIONS: The limitations consisted of the difference in time of the manipulation between the two groups, the richness of the imagery operationalization, generalizability, and the lack of pre-manipulation of interpretation bias assessments. CONCLUSIONS: The imagery-based CBM-I led to more positive interpretation biases, less negative interpretations, and more positive memory biases, indicating that mental imagery can boost the effect of the positive CBM-I.

Sex difference in association between tardive dyskinesia and cognitive deficits in patients with chronic schizophrenia.

BACKGROUND: Tardive dyskinesia (TD), a side effect due to long-term use of antipsychotic medication, is associated with cognitive impairment. Several studies have found sex differences in cognitive impairment in schizophrenia patients, while whether there are sex differences in cognitive performance in schizophrenia patients with TD has not been reported. METHODS: A total of 496 schizophrenia inpatients and 362 healthy controls were recruited for this study. We used the Positive and Negative Syndrome Scale (PANSS) to assess patients' psychopathological symptoms and the Abnormal Involuntary Movement Scale (AIMS) to assess the severity of TD. Cognitive function was measured in 313 of these inpatients and 310 of healthy controls using the Repeatable Battery for Assessment of Neuropsychological Status (RBANS). RESULTS: Patients with schizophrenia performed worse in all cognitive domains than healthy controls(all p < 0.001). Compared to patients without TD, patients with TD had higher PANSS total, PANSS negative symptom subscale and AIMS scores (all p < 0.001), while RBANS total, visuospatial/constructional and attention subscale scores were significantly lower (all p < 0.05). In addition, the visuospatial/constructional and attention indices remained significantly lower in male patients with TD than those without TD (both p < 0.05), but these results were not observed in female patients. Moreover, visuospatial/constructional and attention indices were negatively correlated with total AIMS scores only in male patients (both p < 0.05). CONCLUSION: Our results suggest that there may be sex differences in cognitive impairment in schizophrenia patients with comorbid TD, indicating that female gender may have a protective effect on cognitive impairment in schizophrenia patients caused by TD.

Trait anxiety is related to an impaired attention model for controllable threat cues: Evidence from ERPs.

Attentional bias to threat cues is maladaptive for individuals with high trait anxiety (HTA), but may become adaptive when the dangers signaled by these cues can be controlled by timely actions. However, it remains unclear how HTA individuals allocate attention to controllable threat cues. The current study examined whether trait anxiety is associated with an impaired attention model for controllable threat cues and explored the related underlying neural mechanisms. A sample of 21 participants with low trait anxiety (LTA) and 21 with HTA completed a modified cued anticipation task which allowed participants to control the appearance of threatening pictures associated with controllable threat cues. Results revealed that HTA individuals had no difference in N1 amplitude among controllable threat cues, uncontrollable threat cues, and neutral cues, while LTA individuals showed the greatest N1 amplitude on controllable cues. HTA individuals also exhibited lower N2 amplitude than LTA individuals. The current study provides electrophysiological evidence showing that HTA individuals have impaired attention for processing controllable threat cues and weak inhibitory control. Deficient attention to controllable threat cues may be crucial in the mechanisms underlying trait anxiety.

First-principles investigation of transition metal atom M (M = Cu, Ag, Au) adsorption on CeO2(110).

Transition metal atom M (M = Cu, Ag, Au) adsorption on CeO(2)(110), a technologically important catalytic support surface, is investigated with density-functional theory within the DFT+U formalism. A set of model configurations was generated by placing M at three surface sites, viz., on top of an O, an O bridge site, and a Ce bridge site. Prior to DFT optimization, small distortions in selected Ce-O distances were imposed to explore the energetics associated with reduction of Ce(4+) to Ce(3+) due to charge transfer to Ce during M adsorption. Charge redistribution is confirmed with spin density isosurfaces and site projected density of states. We demonstrate that Cu and Au atoms can be oxidized to Cu(2+) and Au(2+), although the adsorption energy, E(ads), of Au(2+) is less favorable and, unlike Cu(2+), it has not been experimentally observed. Oxidation of Ag always results in Ag(+). For M adsorption at an O bridge site, E(ads)(2NN) > E(ads)(3NN) > E(ads)(1NN) where NN denotes the nearest neighbor Ce(3+) site relative to M. Alternatively, for M adsorption at a Ce bridge site, E(ads)(3NN) > E(ads)(2NN) > E(ads)(1NN). The adsorption behavior of M on CeO(2) (110) is compared with M adsorption on CeO(2)(111).