Unveiling the activity origin of electrochemical oxygen evolution on heteroatom-decorated carbon matrix.

Chemical modification via functional dopants in carbon materials holds great promise for elevating catalytic activity and stability. To gain comprehensive insights into the pivotal mechanisms and establish structure-performance relationships, especially concerning the roles of dopants, remains a pressing need. Herein, we employ computational simulations to unravel the catalytic function of heteroatoms in the acidic oxygen evolution reaction (OER), focusing on a physical model of high-electronegative F and N co-doped carbon matrix. Theoretical and experimental findings elucidate that the enhanced activity originates from the F and pyridinic-N (Py-N) species that achieve carbon activation. This activated carbon significantly lowers the conversion energy barrier from O* to OOH*, shifts the potential-limiting step from OOH* formation to O* generation, and ultimately optimizes the energy barrier of the potential-limiting step. This wok elucidates that the critical role of heteroatoms in catalyzing the reaction and unlocks the potential of carbon materials for acidic OER.

Development of a Highly Specific Fluorescent Probe based on Thiol-ene Click Nucleophilic Cascade Reactions for Delving into the Action Mechanism of Serotonin in Depression.

The intrinsic correlation between depression and serotonin (5-HT) is a highly debated topic, with significant implications for the diagnosis, treatment, and advancement of drugs targeting neurological disorders. To address this important question, it is of utmost priority to understand the action mechanism of serotonin in depression through fluorescence imaging studies. However, the development of efficient molecular probes for serotonin is hindered by the lack of responsive sites with high selectivity for serotonin at the present time. Herein, we developed the first highly selective serotonin responsive site, 3-mercaptopropionate, utilizing thiol-ene click cascade nucleophilic reactions. The novel responsive site was then employed to construct the powerful molecular probe SJ-5-HT for imaging the serotonin level changes in the depression cells and brain tissues. Importantly, the imaging studies reveal that the level of serotonin in patients with depression may not be the primary factor, while the ability of neurons in patients with depression to release serotonin appears to be more critical. Additionally, this serotonin release capability correlates strongly with the levels of mTOR (intracellular mammalian target of rapamycin). These discoveries could offer valuable insights into the molecular mechanisms underpinning depression and furnish mTOR as a novel direction for the advancement of antidepressant therapies.

Occurrence and risk factors for post-stroke delirium: A systematic review and meta-analysis.

OBJECTIVES: Delirium is a significant health concern in acute stroke patients. We aim to systematically summarize existing evidence to conduct a meta-analysis to quantify the occurrence and risk factors for delirium after acute stroke. METHOD: PubMed, EMBASE and MEDLINE were searched from inception to Feb. 2023 for prospective observational studies that reported the incidence or prevalence of post-stroke delirium and/or evaluated potential risk factors. The search strategy was created using controlled vocabulary terms and text words for stroke and delirium. We performed a meta-analysis of the estimates for occurrence and risk factors using random-effects models. Meta-regression and subgroup meta-analyses were conducted to explore the sources of heterogeneity. Study quality and quality of evidence were assessed using the customized Newcastle-Ottawa Scale and GRADE, respectively. RESULTS: Forty-nine studies that enrolled 12383 patients were included. The pooled occurrence rate of post-stroke delirium was 24.4 % (95 %CI, 20.4 %-28.9 %, I2=96.2 %). The pooled occurrence of hyperactive, hypoactive, and mixed delirium was 8.5 %, 5.7 % and 5.0 %, respectively. Study location, delirium assessment method and stroke type independently affected the heterogeneity of the pooled estimate of delirium. Statistically significant risk factors were older age, low education level, cigarette smoking, alcohol drinking, atrial fibrillation, lower ADL level, higher pre-stroke mRS score, premorbid cognitive impairment or dementia, aphasia, total anterior circulation impairment, higher National Institute of Health Stroke Scale score and infection. CONCLUSIONS: Delirium affected 1 in 4 acute stroke patients, although reported rates may depend on assessment method and stroke type. Timely prevention, recognition and intervention require prioritizing patients with dominant risk factors.

Manipulation of Oxidation States on Phase Boundary via Surface Layer Modification for Enhanced Alkaline Hydrogen Electrocatalysis.

In alkaline water electrolysis and anion exchange membrane water electrolysis technologies, the hydrogen evolution reaction (HER) at the cathode is significantly constrained by a high energy barrier during the water dissociation step. This study employs a phase engineering strategy to construct heterostructures composed of crystalline Ni4W and amorphous WOx aiming to enhance catalytic performance in the HER under alkaline conditions. This work systematically modulates the oxidation states of W within the amorphous WOx of the heterostructure to adjust the electronic states of the phase boundary, the energy barriers associated with the water dissociation step, and the adsorption/desorption properties of intermediates during the alkaline HER process. The optimized catalyst, Ni4W/WOx-2, with a quasi-metallic state of W coordinated by a low oxygen content in amorphous WOx, demonstrates exceptional catalytic performance (22 mV@10 mA cm-2), outperforming commercial Pt/C (30 mV@10 mA cm-2). Furthermore, the operando X-ray absorption spectroscopy analysis and theoretical calculations reveal that the optimized W atoms in amorphous WOx serve as active sites for water dissociation and the nearby Ni atoms in crystalline Ni4W facilitated the release of H2. These findings provide valuable insights into designing efficient heterostructured materials for energy conversion.

A fluorescence probe for imaging lipid droplet and visualization of diabetes-related polarity variations.

Diabetes mellitus is a disorder that affects lipid metabolism. Abnormalities in the lipid droplets (LDs) can lead to disturbances in lipid metabolism, which is a significant feature of diabetic patients. Nevertheless, the correlation between diabetes and the polarity of LDs has received little attention in the scientific literature. In order to detect LDs polarity changes in diabetes illness models, we created a new fluorescence probe LD-DCM. This probe has a stable structure, high selectivity, and minimal cytotoxicity. The probe formed a typical D-π-A molecular configuration with triphenylamine (TPA) and dicyanomethylene-4H-pyran (DCM) as electron donor and acceptor parts. The LD-DCM molecule has an immense solvatochromic effect (λem = 544-624 nm), fluorescence enhancement of around 150 times, and a high sensitivity to polarity changes within the linear range of Δf = 0.28 to 0.32, all due to its distinctive intramolecular charge transfer effect (ICT). In addition, LD-DCM was able to monitor the accumulation of LDs and the reduction of LDs polarity in living cells when stimulated by oleic acid, lipopolysaccharide, and high glucose. More importantly, LD-DCM has also been used effectively to detect polarity differences in organs from diabetic, drug-treated, and normal mice. The results showed that the liver polarity of diabetic mice was lower than that of normal mice, while the liver polarity of drug-treated mice was higher than that of diabetic mice. We believe that LD-DCM has the potential to serve as an efficient instrument for the diagnosis of disorders that are associated with the polarity of LDs.

Elevated triglycerides and low triiodothyronine: Key risk factors for coronary artery calcification in patients with schizophrenia.

OBJECTIVE: Coronary artery calcification (CAC) is a well-established independent predictor of coronary heart disease, and patients with schizophrenia have significantly higher rates compared to the general population. We performed this study to examine the population-specific risk factors associated with CAC in patients with schizophrenia. METHODS: In this cross-sectional study, patients with schizophrenia who underwent low-dose chest CT scans between January 2020 and December 2021 were analyzed. Ordinary CAC scores and results of routine blood tests were obtained. Logistic regression was used to calculate the odds ratio (OR) for potential risk factors in patients with and without CAC, while the negative binomial additive model was used to explore the dose-response relationship between risk factors and CAC score. RESULTS: Of the 916 patients, 233 (25.4 %) had CAC, while 683 (74.6 %) did not. After adjusting for confounding factors, higher triglyceride levels (OR = 1.20, 95 % confidence interval (CI): 1.04 to 1.38, p = 0.013) and low triiodothyronine levels (OR = 0.50, 95 % CI: 0.29 to 0.84; p = 0.010) were identified as risk factors for CAC. Both triglycerides (p = 0.021) and triiodothyronine (p = 0.010) were also found to have significant dose-response relationships with CAC scores according to the negative binomial additive model in the exploratory analysis. CONCLUSIONS: This study highlights elevated serum triglycerides and decreased triiodothyronine levels as population-specific risk factors for CAC in patients with schizophrenia, suggest the need for close monitoring of CAC in patients with schizophrenia and further prospective trials to provide additional evidence on this topic.