Synergistic effect of Polydopamine incorporated Copper electrocatalyst by dopamine oxidation for efficient hydrogen production.

Tuning the metal-support interaction in electrocatalysts has been proposed as a viable method for manipulating the electronic structure and catalytic activity. In this work, inspired by natural hydrogenase enzyme, electrocatalysts with a hybrid metal-matrix complex using polydopamine (PDA) as a supporting matrix were synthesized for efficient green hydrogen production. Among the various Metal-PDA electrocatalysts, Cu-PDA shows outstanding catalytic activity (low overpotential (ƞ) of 104 mV at 10 mA cm-2 and small Tafel slope of 60.67 mV dec-1) with high stability at neutral pH. Also, the electrochemical impedance spectroscopy analysis verified the fast charge transfer properties of Cu-PDA (2.8 Ω cm2) than PDA (26 Ω cm2), indicating a faster proton-coupled electron transfer process in Cu-PDA electrocatalyst. Therefore, emerging nature inspired organic ligand-transition metal ion complexes can be extensively encouraged as a prospective HER electrocatalyst under neutral conditions.

Manipulating wettability of catalytic surface for improving ammonia production from electrochemical nitrogen reduction.

An electrochemical nitrogen reduction reaction (ENRR) is considered a promising alternative for the traditional Haber-Bosch process. In this study, we present a method for improving the ENRR by controlling the wettability of the catalyst surface, suppressing the hydrogen evolution reaction (HER) while facilitating N2 adsorption. Reduced-graphene oxide (rGO) with a hydrophobic surface property and a contact angle (C.A.) of 59° was synthesized through a high-density atmospheric plasma deposition. Two other hydrophilic and superhydrophobic surfaces with a C.A. of 15° and 150° were developed through additional argon plasma and heat treatment of as-deposited rGO, respectively. The ENRR results showed that the ammonia yield and Faradaic efficiency tended to increase with increasing hydrophobicity. Electrochemical measurements reveal that superhydrophobic rGO achieves a higher Faradaic efficiency (5.73 %) at -0.1 V (vs RHE) and a higher NH3 yield (9.77 µg h-1 cm-2) at -0.4 V (vs RHE) in a 0.1 M KOH electrolyte. In addition, the computational fluid dynamics simulation confirmed that the amount of time the N2 gas remains on the surface could increase by improving the hydrophobicity of the catalytic surface. This study inspires the development of the rGO electrocatalyst through surface wettability modification for boosting ammonia electrosynthesis.

Perspectives on the Happiness of Community-Dwelling Elderly in Korea.

OBJECTIVE: A community survey was performed to investigate the factors and perspectives associated with happiness among the elderly in Korea (≥60 years). METHODS: Eight hundred volunteers selected from participants in the Ansan Geriatric study (AGE study) were enrolled, and 706 completed the survey. The Happiness Questionnaire (HQ), which asks four questions about happiness, was administered. To explore the relationship between happiness and depression, the Geriatric Depression Scale (GDS) and the Beck Depression Inventory (BDI) also were administered. RESULTS: The participants' average level of happiness, determined using a 100-mm visual analogue scale (VAS) of the HQ, was 64.7±26.0. The happiest situations for most people were "getting together with family" (23.8%) and "living in peace with family members (well-being)" (13.2%). Frequent reasons for not being happy were "worsened health condition" (28.7% of the not-happy group), "economic problems of their own" (16.5%), and "economic problems of their children" (14.8%). The participants' choices regarding the essential conditions for happiness were "good health" (65.3%) and "being with family" (20.5%). The BDI and GDS scores were negatively related to the happiness score. A preliminary scale [Happy (Haeng-Bok, ) aging scale] based on the HQ for measuring the happiness level of the Korean elderly was suggested for follow-up studies. CONCLUSION: The most important factors determining the happiness of the community-dwelling elderly in Korea were good family relationships, economic stability, and good health. A higher depression score negatively impacted happiness among Korean elders. Further studies on the factors in their happiness are required.

Sensitivity of cognitive tests in four cognitive domains in discriminating MDD patients from healthy controls: a meta-analysis.

BACKGROUND: We performed a meta-analysis in order to determine which neuropsychological domains and tasks would be most sensitive for discriminating between patients with major depressive disorder (MDD) and healthy controls. METHODS: Relevant articles were identified through a literature search of the PubMed and Cochrane Library databases for the period between January 1997 and May 2011. A meta-analysis was conducted using the standardized means of individual cognitive tests in each domain. The heterogeneity was assessed, and subgroup analyses according to age and medication status were performed to explore the sources of heterogeneity. RESULTS: A total of 22 trials involving 955 MDD patients and 7,664 healthy participants were selected for our meta-analysis. MDD patients showed significantly impaired results compared with healthy participants on the Digit Span and Continuous Performance Test in the attention domain; the Trail Making Test A (TMT-A) and the Digit Symbol Test in the processing speed domain; the Stroop Test, the Wisconsin Card Sorting Test, and Verbal Fluency in the executive function domain; and immediate verbal memory in the memory domain. The Finger Tapping Task, TMT-B, delayed verbal memory, and immediate and delayed visual memory failed to separate MDD patients from healthy controls. The results of subgroup analysis showed that performance of Verbal Fluency was significantly impaired in younger depressed patients (<60 years), and immediate visual memory was significantly reduced in depressed patients using antidepressants. CONCLUSIONS: Our findings have inevitable limitations arising from methodological issues inherent in the meta-analysis and we could not explain high heterogeneity between studies. Despite such limitations, current study has the strength of being the first meta-analysis which tried to specify cognitive function of depressed patients compared with healthy participants. And our findings may provide clinicians with further evidences that some cognitive tests in specific cognitive domains have sensitivity to discriminate MDD patients from healthy controls.

Zonisamide produces weight loss in psychotropic drug-treated psychiatric outpatients.

This study examined the long-term effectiveness and tolerability of zonisamide for weight control in psychiatric outpatients using various psychotropic medications. We conducted a systematic chart review of 82 psychiatric outpatients with unwanted weight gain after the introduction of psychotropic drugs between January 2008 and September 2009 at Korea University Ansan Hospital. The primary outcome measure was the effect of zonisamide on body mass index (BMI). Additional outcome measures included safety and tolerability as assessed by the clinical global impression-severity of illness scale (CGI-S) and discontinuation rate. The mean final dose of zonisamide was 124.6±53.4 mg/day and ranged from 50mg/day to 300 mg/day. The mean BMI reduction was 0.8±1.7 kg/m(2) and ranged from -2.9 kg/m(2) to 4.7 kg/m(2) (p<0.001). We also observed a significant reduction in CGI-S scores from the baseline (3.8±0.9) to the endpoint (3.3±0.8; p<0.001). Twelve patients (14.6%) discontinued their zonisamide treatment due to its side effects. Patients treated with zonisamide showed significant weight loss. Furthermore, its treatment was generally safe and well tolerated with few negative effects on patients' overall psychiatric symptoms. Additional research is required to confirm these results and to investigate whether patients have rebound weight gains after discontinuing zonisamide.