Molecular Co-Catalyst Confined within a Metallacage for Enhanced Photocatalytic CO2 Reduction.

The construction of structurally well-defined supramolecular hosts to accommodate catalytically active species within a cavity is a promising way to address catalyst deactivation. The resulting supramolecular catalysts can significantly improve the utilization of catalytic sites, thereby achieving a highly efficient chemical conversion. In this study, the Co-metalated phthalocyanine (Pc-Co) was successfully confined within a tetragonal prismatic metallacage, leading to the formation of a distinctive type of supramolecular photocatalyst (Pc-Co@Cage). The host-guest architecture of Pc-Co@Cage was unambiguously elucidated by single-crystal X-ray diffraction (SCXRD), NMR, and ESI-TOF-MS, revealing that the single cobalt active site can be thoroughly isolated within the space-restricted microenvironment. In addition, we found that Pc-Co@Cage can serve as a homogeneous supramolecular photocatalyst that displays high CO2 to CO conversion in aqueous media under visible light irradiation. This supramolecular photocatalyst exhibits an obvious improvement in activity (TONCO = 4175) and selectivity (SelCO = 92%) relative to the nonconfined Pc-Co catalyst (TONCO = 500, SelCO = 54%). The present strategy provided a rare example for the construction of a highly active, selective, and stable photocatalyst for CO2 reduction through a cavity-confined molecular catalyst within a discrete metallacage.

A General Strategy Based on Hetero-Charge Coupling Effect for Constructing Single-Atom Sites.

Single-atom catalysts have emerged as cutting-edge hotspots in the field of material science owing to their excellent catalytic performance brought about by well-defined metal single-atom sites (M SASs). Herein, we report a novel synthesis strategy based on the hetero-charge coupling effect (HCCE) to prepare M SASs loaded on N and S co-doped porous carbon (M1/NSC). The proposed strategy was widely applied to prepare 17 types of M1/NSC composed of single or multi-metal with the integrated regulation of the coordination environment and electronic structure, exhibiting good universality and flexible adjustability. Furthermore, this strategy provided a low-cost method of efficiently synthesizing M1/NSC with high yields, that can produce more than 50 g catalyst at one time, which is key to large-scale production. Among various as-prepared unary M1/NSC catalysts, Fe1/NSC delivered excellent performance for electrocatalytic nitrate reduction to NH3 with high NH3 Faradaic efficiency of 86.6% and high NH3 yield rate of 1.50 mg h-1 mgcat.-1 at -0.6 V vs. RHE. Even using Fe1/NSC as a cathode in a Zn-nitrate battery, it exhibited a high open circuit voltage of 1.756 V and high energy density of 4.42 mW cm-2 with good cycling stability.

D-Band Center Optimization of Edge-Rich Ultrathin RuZn Nanosheets With Moiré Superlattices for pH-Universal Hydrogen Evolution Reaction.

Electrocatalytic hydrogen evolution reaction (HER) is a promising way to produce pure and clean hydrogen. However, the preparation of efficient and economical catalysts for pH-universal HER remains a challenging but rewarding task. Herein, ultrathin RuZn nanosheets (NSs) with moiré superlattices and abundant edges are synthesized. The RuZn NSs with unique structure exhibit superb HER performance with overpotentials of 11, 13, and 29 mV to achieve 10 mA cm-2 in 1 M KOH, 1 M PBS, and 0.5 M H2 SO4 , respectively, which is substantially lower than those of Ru NSs and RuZn NSs without moiré superlattices. Density functional theory investigations reveal that the charge transfer from Zn to Ru will lead the appropriate downshift of the d-band center of surface Ru atoms, thus accelerating hydrogen desorption from the Ru sites, lowering the dissociation energy barrier of water and greatly improving the HER performance. This work provides an effective design scheme for high-performance HER electrocatalysts over a wide pH range, and propose a general route to prepare Ru-based bimetallic nanosheets with moiré superlattices.

LiMnO2@rGO nanocomposites for high-performance lithium-ion battery cathodes.

Composites of reduced graphene oxide (rGO) and layered LiMnO2 (LiMnO2@rGO) were successfully synthesized and demonstrated via a one-pot hydrothermal route at a temperature of 200 °C for 12 h. The obtained LiMnO2@rGO was characterized by x-ray diffraction, transmission electron microscopy, Fourier transform infrared spectra and Raman spectra. Electrochemical performance tests of LiMnO2@rGO and LiMnO2 cathodes exhibited that after graphene oxide was loaded, the discharge capacity and cycling performance were greatly improved, the maximum discharge capacity reached 185.6 mAh g-1 at the current density of 100 mA g-1 with retention capacity higher than 80% even after 100 cycles between 2 and 4.5 V vs. Li+/Li, which is much better than most previous reports (table S1). The principles of the corresponding phenomenon were fully explained by the low electron conductivity, high structural stability and lithium diffusion coefficient of LiMnO2@rGO, which was also proved by cyclic voltammetry testing, electrochemical impedance spectroscopy and relevant equivalent circuit fitting. This work not only provides significant insights into the relationship between the structure and electrochemical performance of electrodes, but also shows the great potential of LiMnO2@rGO composite electrodes applied as the cathode materials of lithium-ion batteries.

Agricultural work and reduced circulating uric acid are both associated with initial hospital admission for Parkinson's disease.

Monoamine oxidase type B inhibitors act in Parkinson's disease (PD) via potentiation of dopamine, but may also have neuroprotective effects by reducing oxidative damage. Oxidative damage is also a feature of environmental toxins, including pesticides, that are an established risk factor for PD. Another risk factor is low circulating uric acid (UA), which may relate to UA being the major endogenous antioxidant in the human body. We have undertaken a study of 192 initial admissions for PD in a general hospital neurology department in a partly rural region of Southern China to determine if there is an increased rate of PD in agricultural workers who have a high risk of exposure to pesticides, and how it may relate to deficits in UA. We found a disproportionately high number of agricultural workers admitted with PD (66.7% vs. 54.3% of all neurology admissions) and that PD subjects have a substantial reduction in UA. This is further reduced in agricultural workers and thus may contribute to the increased vulnerability of this group to PD.

Highly Efficient and Selective Visible-Light Driven CO2 Reduction by Two Co-Based Catalysts in Aqueous Solution.

Photocatalytic CO2 reduction has been considered as a promising approach to solve energy and environmental problems. Nevertheless, developing inexpensive photocatalysts with high efficiency and selectivity remains a big challenge. In this study, two Co-based complexes [Co2(L1)Cl2] (1-Co) and [Co(L2)Cl] (2-Co) were synthesized by treating two DPA-based (DPA: dipicolylamine) ligands with Co2+, respectively. Under visible-light irradiation, the performance of 1-Co as a homogeneous photocatalyst for CO2 reduction in aqueous media has been explored by using [Ru(phen)3]2+ as a photosensitizer, and triethylolamine (TEOA) as a sacrificial reductant. 1-Co shows high photocatalytic activity for CO2-to-CO conversion, corresponding to the high TONCO of 2600 and TOFCO of 260 h-1 (TONCO = turnover number for CO; TOFCO = turnover frequency for CO). High selectivity of 97% for CO formation is also achieved. The control experiments catalyzed by 2-Co demonstrated that two Co(II) centers in 1-Co may operate independently and activate one CO2 molecule each. Furthermore, the proposed mechanism of 1-Co for photocatalytic CO2 reduction has been investigated via electrochemical analysis, a series of quenching experiments, and density functional theory calculations.

Lower uric acid is associated with poor short-term outcome and a higher frequency of posterior arterial involvement in ischemic stroke.

Uric acid has neuroprotective properties in experimental and clinical studies of neurodegenerative disease. It is, however, associated with increased risk of stroke, yet, despite some inconsistent findings, increasing evidence suggests it may also be related to improved stroke outcomes. We have determined whether there is an effect of plasma uric acid on the short-term outcome of stroke patients in a general hospital setting using the modified Rankin Scale (mRS). We also investigated the relationship of uric acid with other clinical correlates. Plasma uric acid was determined in 108 acute ischemic stroke patients and their mRS scores measured. Patients with a poor outcome (mRS > 2) had significantly lower uric acid than those with a better outcome; this remained after correcting for the effect of sex on uric acid concentrations. There was no significant association with other epidemiological factors or with cognitive function determined by Mini-Mental State Examination. An association between uric acid and the cerebral circulation was also found in which lower uric acid occurs with posterior artery involvement. These findings demonstrate in a naturalistic cohort of patients the association of uric acid with short-term disability following ischemic stroke. They also raise the question of whether uric acid may influence the regional brain involvement in stroke.

Construction of Dual-Active Sites by Interfacing with Polyhydroxy Fullerene on Nickel Hydroxide Surfaces to Promote CO2 Deep Photoreduction to CH4.

Due to the complex series of elementary steps involved, achieving deep photoreduction of CO2 to multielectron products such as CH4 remains a challenging task. Therefore, it is crucial to strategically design catalysts that facilitate the controlled formation of the crucial intermediates and provide precise control over the reaction pathway. Herein, we present a pioneering approach by employing polyhydroxy fullerene (PHF) molecules to modify the surface of Ni(OH)2, creating stable and effective synergistic sites to enhance the formation of CH4 from CO2 under light irradiation. As a result, the optimized PHF-modified Ni(OH)2 cocatalyst achieves a CH4 production rate of 455 µmol g-1 h-1, with an electron-based selectivity of approximately 60%. The combination of in situ characterizations and theoretical calculations reveals that the hydroxyl species on the surface of PHF can participate in stabilizing crucial intermediates and facilitating water activation, thereby altering the reaction pathway to form CH4 instead of CO. This study provides a novel approach to regulating the selectivity of photocatalytic CO2 reduction by exploring molecular surface modification through interfacing with functionalized carbon clusters.

Interfacial Co-O-Cu bonds prompt electrochemical nitrate reduction to ammonia in neutral electrolyte.

In this work, the formed interfacial Co-O-Cu bonds in Co-doped Cu(OH)2 (Co2-Cu(OH)2) sufficiently expose active sites and improve the reaction kinetics. As a result, the optimal Co2-Cu(OH)2 provides an amazing faradaic efficiency (91.6%), high selectivity (93.2%) and robust stability toward the NO3RR.

The Influence of Agricultural Work and Plasma Uric Acid on Hospital Admission for Alzheimer's Disease.

BACKGROUND: Exposure to environmental neurotoxins associated with agricultural work, such as pesticides, may be a risk factor for neurodegenerative disorders such as Alzheimer's (AD) and Parkinson's (PD) diseases. There is strong evidence that such exposure is associated with the development of PD; for AD the current evidence is equivocal. Several mechanisms are proposed to mediate this environmental toxicity, one of which is oxidative stress. Uric acid (UA) is an endogenous antioxidant, low levels of which are also implicated in neurodegenerative disease. OBJECTIVE: This study aimed to determine whether agricultural work was a risk factor for AD in a population in which its association with PD was established, and whether UA was also associated with AD in this cohort. METHODS: Hospital records of subjects meeting criteria for AD (n = 128) or vascular dementia (VaD) (n = 178) after hospital admission for symptoms of dementia were studied. History of agricultural work and plasma UA were recorded and their relationship to diagnosis determined. RESULTS: In contrast to previous findings in this population in which agricultural work was strongly associated with PD, a history of agricultural work was not over-represented in hospital admission for AD versus VaD. AD was associated with a reduced level of circulating UA compared with VaD. CONCLUSION: Agricultural work as a likely proxy for exposure to pesticides appears not to be a risk factor for AD to the extent found in PD, perhaps reflecting their differences in neuronal pathology. Nevertheless, findings with UA suggests that oxidative stress may be an important factor in AD pathogenesis.

Enhancing the durability of Au clusters in CO2 photoreduction via encapsulation in Cu-based metal-organic frameworks.

Here, we report the encapsulation of Au25 nanoclusters in a Cu3(BTC)2 metal-organic framework (Au25@Cu-BTC), which can achieve CO2 photoreduction for selective CO production in a gas-solid reaction system at low-concentration CO2 atmospheres (even to 0.1%), with remarkably enhanced durability up to at least 48 h.

Regulating charge distribution of Cu3PdN nanocrystals for nitrate electroreduction to ammonia.

As-synthesized Cu3PdN nanocrystals displayed high faradaic efficiency and selectivity for nitrate-to-ammonia conversion. The excellent performances can be attributed to the charge redistribution in Cu3PdN as a result of modulations of the electronic structures of Pd and Cu atoms, which altered the adsorption activation energy of the intermediates during the nitrate reduction reaction process.

Reliability and validity of the brief psychosomatic symptom scale (BPSS) in patients from general hospitals.

OBJECTIVES: To verify the Brief Psychosomatic Symptom Scale (BPSS) among patients with psychosomatic-related disorders in general hospitals and determine the threshold of BPSS. METHODS: The BPSS is a shortened 10-item version of the psychosomatic symptoms scale (PSSS). Data from 483 patients and 388 healthy controls were included for psychometric analyses. Internal consistency, construct validity, and factorial validity were verified. The threshold of BPSS in distinguishing psychosomatic patients from healthy controls were determined using receiver operating characteristic (ROC) curve analysis. The ROC curve of the BPSS was compared with that of the PSSS and patient health questionnaire-15 (PHQ-15) by using Venkatraman's method with 2000 times Monte-Carlo simulations. RESULTS: The reliability of the BPSS was good with Cronbach's α of 0.831. BPSS was significantly correlated with PSSS (r = 0.886, P < 0.001), PHQ-15 (r = 0.752, P < 0.001), PHQ-9 (r = 0.757, P < 0.001) and GAD-7 (r = 0.715, P < 0.001), which indicated good construct validity. ROC analyses demonstrated that the AUC of the BPSS was comparable with that of PSSS. The gender-specific threshold of BPSS was determined as ≥8 in males and ≥ 9 in females. CONCLUSIONS: The BPSS is a brief and validated instrument for screening common psychosomatic symptoms.

Chemiluminescence determination of sulphite using a cyclometalated iridium complex as chemiluminescence reagent.

A simple, fast and accurate chemiluminescence (CL) method for the determination of sulphite has been developed, based on its sensitizing effect on the CL reaction between a novel water-soluble iridium complex, [(dpci)2Ir(bvbbi)](PF6) (dpci = 3,4-diphenylcinnoline; bvbbi = N,N'-bivinylester-(1)H,(1')H-[2,2'] bibenzimidazole) and cerium(IV). Under the optimal experimental conditions, the increased CL response was linear, with the concentration of sulphite over the range 5.0 × 10(-7)-5.0 × 10(-4) mol/L. The detection limit of the method was 1.6 × 10(-7) mol/L, with a relative standard deviation (RSD) of 2.7% for nine repetitive determination of 1.0 × 10(-4) mol/L sulphite. The method was successfully applied to the quantitative analysis of sulphite in sugar samples. The possible reaction mechanism of sulphite on the [(dpci)2Ir(bvbbi)](PF6)-cerium(IV) system is also briefly discussed.

Enhanced chemiluminescence of the luminol-AgNO3 system by Ag nanoparticles.

The oxidation reaction of luminol with AgNO(3) can produce chemiluminescence (CL) in the presence of silver nanoparticles (NPs) in alkaline solution. Based on the studies of UV-vis absorption spectra, photoluminescence (PL) spectra and CL spectra, a CL enhancement mechanism is proposed. The CL emission spectrum of the luminol-AgNO(3)-Ag NPs system indicated that the luminophore was still 3-aminophthalate. On injection of silver nanoparticles into the mixture of luminol and AgNO(3), they catalysed the reduction of AgNO(3) by luminol. The product luminol radicals reacted with the dissolved oxygen, to produce a strong CL emission. As a result, the CL intensity was substantially increased. Moreover, the influences of 18 amino acids, e.g. cystine, tyrosine and asparagine, and 25 organic compounds, including gallic acid, tannic acid and hydroquinone, on the luminol-AgNO(3)-Ag NPs CL system were studied by a flow-injection procedure, which led to an effective method for detecting these compounds.

Highly dispersed Cr oxygenated species on Pt nanowire assemblies for enhanced electrocatalytic methanol oxidation.

In this paper, Cr oxygenated species dispersed on Pt nanowire assemblies (PtCrOX NWs) were successfully prepared for the methanol oxidation reaction by a metal precursor dilution strategy. Notably, the PtCrOX NWs catalyst exhibits excellent performance for electrocatalytic methanol oxidation. Density functional theory results revealed that the doped Cr oxygenated species, which moderated the electronic structure of the Pt atoms, can significantly decrease the free energy of COOH* formation, thus leading to superior methanol oxidation performance.

A New Dibenzoquinoxalineimide-Based Wide-Bandgap Polymer Donor for Polymer Solar Cells.

The molecular design of a wide-bandgap polymer donor is critical to achieve high-performance organic photovoltaic devices. Herein, a new dibenzo-fused quinoxalineimide (BPQI) is successfully synthesized as an electron-deficient building block to construct donor-acceptor (D-A)-type polymers, namely P(BPQI-BDT) and P(BPQI-BDTT), using benzodithiophene and its derivative, which bears different side chains, as the copolymerization units. These two polymers are used as a donor, and the narrow bandgap (2,20-((2Z,20Z)-((12,13-bis(2-ethylhexyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]thiadiazolo [3,4-e]thieno[2,″30':4',50]thieno[20,30:4,5]pyrrolo[3,2g]thieno[20,30:4,5]thieno[3,2-b]indole-2,10 diyl)bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile) Y6 is used as an acceptor to fabricate bulk heterojunction polymer solar cell devices. Y6, as a non-fullerene receptor (NFA), has excellent electrochemical and optical properties, as well as a high efficiency of over 18%. The device, based on P(BPQI-BDTT):Y6, showed power conversion efficiencies (PCEs) of 6.31% with a JSC of 17.09 mA cm-2, an open-circuit voltage (VOC) of 0.82 V, and an FF of 44.78%. This study demonstrates that dibenzo-fused quinoxalineimide is a promising building block for developing wide-bandgap polymer donors.

Influence of Fluorine Substitution on the Photovoltaic Performance of Wide Band Gap Polymer Donors for Polymer Solar Cells.

The design and development of wide band gap (WBG) polymer donors are critical for achieving high power conversion efficiencies (PCEs) in polymer solar cells. In this work, four WBG polymer donors, Q4, Q5, Q6, and Q7, with different numbers and positions of fluorine substitution (n = 0, 2, 2, and 4, respectively) were prepared, and the effect of fluorination on their photovoltaic performance was systematically investigated. When blended with a small-molecule electron acceptor MeIC, the devices based on Q4, Q5, Q6, and Q7 showed PCEs of 10.34, 11.06, 5.26, and 0.48%, respectively. When coupled with a low band gap polymer acceptor PYIT to fabricate all-polymer solar cells (all-PSCs), while the other three polymers (Q5-Q7) exhibited much lower PCEs in the range of 0.12-6.71%, the Q4 polymer-based all-PSCs showed the highest PCE of 15.06%, comparable to that of the devices fabricated with the star polymer donor PM6 (PCE = 15.00%). Detailed physicochemical and morphological studies revealed that an over-substitution of F in Q7 results in undesired low-lying HOMO levels and phase separation with the acceptors, thus resulting in its inferior PCEs. Moreover, the less F-substitution and controlling of the positions of F-substitution position in Q4 and Q5 can improve the HOMO energy level matching as well as morphologies between these two polymers with the acceptors, which in turn gives rise to higher performances. Clearly, our results indicate that Q4 is a promising donor candidate for high-performance all-PSCs, and the fine-tuning of both the number and positions of F-substitution in the polymer backbone is essential in developing high-performance WBG polymer donors.

Copper single-atom catalysts with photothermal performance and enhanced nanozyme activity for bacteria-infected wound therapy.

Nanozymes have become a new generation of antibiotics with exciting broad-spectrum antibacterial properties and negligible biological toxicity. However, their inherent low catalytic activity limits their antibacterial properties. Herein, Cu single-atom sites/N doped porous carbon (Cu SASs/NPC) is successfully constructed for photothermal-catalytic antibacterial treatment by a pyrolysis-etching-adsorption-pyrolysis (PEAP) strategy. Cu SASs/NPC have stronger peroxidase-like catalytic activity, glutathione (GSH)-depleting function, and photothermal property compared with non-Cu-doped NPC, indicating that Cu doping significantly improves the catalytic performance of nanozymes. Cu SASs/NPC can effectively induce peroxidase-like activity in the presence of H2O2, thereby generating a large amount of hydroxyl radicals (•OH), which have a certain killing effect on bacteria and make bacteria more susceptible to temperature. The introduction of near-infrared (NIR) light can generate hyperthermia to fight bacteria, and enhance the peroxidase-like catalytic activity, thereby generating additional •OH to destroy bacteria. Interestingly, Cu SASs/NPC can act as GSH peroxidase (GSH-Px)-like nanozymes, which can deplete GSH in bacteria, thereby significantly improving the sterilization effect. PTT-catalytic synergistic antibacterial strategy produces almost 100% antibacterial efficiency against Escherichia coli (E. coli) and methicillin-resistant Staphylococcus aureus (MRSA). In vivo experiments show a better PTT-catalytic synergistic therapeutic performance on MRSA-infected mouse wounds. Overall, our work highlights the wide antibacterial and anti-infective bio-applications of Cu single-atom-containing catalysts.

Uric Acid and High-Density Lipoprotein Cholesterol Are Differently Associated with Alzheimer's Disease and Vascular Dementia.

Uric acid (UA) is a major contributor to naturally-occurring antioxidant activity and is thought to have protective effects against neurodegenerative processes. However, UA is also implicated as a risk factor in vascular, including cerebrovascular, disease. Its association with, and role in, dementia and its component diseases including Alzheimer's disease (AD) and vascular dementia (VaD) remains unclear and inconsistently studied. Changes in blood lipids, particularly cholesterol measures, have also been implicated in dementias although the relationship or interactions with UA have been little studied.We have measured plasma UA and lipids taken from 187 subjects first attending a general hospital neurology department for symptoms associated with dementia, and from a series of 79 healthy control subjects. Diagnoses of AD and VaD were made following neuroimaging; laboratory measures were compared between dementia and control groups and between AD and VaD subgroups. No overall change in UA was seen in dementia, although a substantial and highly significant reduction was found in the AD patients. Reduced values in total cholesterol, HDL, and LDL were found in dementia, independent of statin treatment. Further investigation found a significant reduction of HDL only in the VaD group, while total cholesterol was significantly reduced in both AD and VaD subjects.These findings indicate that in our Chinese sample, UA deficits are specifically associated with AD, while deficits in HDL cholesterol found in dementia tend to be greater in VaD.