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Background: The patent foramen ovale (PFO) and interatrial block (IAB) are associated with cryptogenic stroke (CS). However, the role of the interaction between PFO and IAB in CS remains unclear. Methods: This case–control study enrolled 256 patients with CS and 156 individuals without a history of stroke or transient ischemic attack. IAB was defined as P wave duration > 120 ms. PFO was evaluated by contrast transesophageal echocardiography, and classified as no-PFO, low-risk PFO and high-risk PFO. Multiplicative and additive interaction analysis were used to assess the interaction between PFO and IAB in CS. Results: Multiplicative interaction analysis unveiled a significant interaction between IAB and low-risk PFO in CS (OR for interaction = 3.653, 95% CI, 1.115–12.506; P = 0.037). Additive interaction analysis indicated that 68.4% (95% CI, 0.333–1.050; P < 0.001) of the increased risk of CS related to low-risk PFO was attributed to the interaction with IAB. The results were robust in multivariate analysis. However, but no significant multiplicative or additive interaction was observed between IAB and high-risk PFO. When stratified by IAB, high-risk PFO was associated with CS in both patients with IAB (OR, 4.186; 95% CI, 1.617–10.839; P = 0.003) and without IAB (OR, 3.476; 95% CI, 1.790–6.750; P < 0.001). However, low-risk PFO was only associated with CS in patients with IAB (OR, 2.684; 95% CI, 1.007–7.149; P = 0.048) but not in those without IAB (OR, 0.753; 95% CI, 0.343–1.651; P = 0.479). Conclusion: The interaction between IAB and PFO might play an important role in CS, particularly in cases with low-risk PFO. [ABSTRACT FROM AUTHOR]

Transition‐metal oxyhydroxides are attractive catalysts for oxygen evolution reactions (OERs). Further studies for developing transition‐metal oxyhydroxide catalysts and understanding their catalytic mechanisms will benefit their quick transition to the next catalysts. Herein, Mo‐doped CoOOH was designed as a high‐performance model electrocatalyst with durability for 20 h at 10 mA cm−2. Additionally, it had an overpotential of 260 mV (glassy carbon) or 215 mV (nickel foam), which was 78 mV lower than that of IrO2 (338 mV). In situ, Raman spectroscopy revealed the transformation process of CoOOH. Calculations using the density functional theory showed that during OER, doped Mo increased the spin‐up density of states and shrank the spin‐down bandgap of the 3d orbits in the reconstructed CoOOH under the electrochemical activation process, which simultaneously optimized the adsorption and electron conduction of oxygen‐related intermediates on Co sites and lowered the OER overpotentials. Our research provides new insights into the methodical planning of the creation of transition‐metal oxyhydroxide OER catalysts. [ABSTRACT FROM AUTHOR]

Promoting the activity of biological enzymes under in vitro environment is a promising technique for bioelectrocatalytic reactions, such as the conversion of carbon dioxide (CO2) into valuable chemicals, which is a promising strategy to address the environmental issue of CO2 in the atmosphere; however, this technique remains challenging. Herein, a nanocage structure for enzyme confinement is synthesized to enable the in situ encapsulation of formate dehydrogenase (FDH) in a porous metal–organic framework, which acts as a coenzyme and boosts the hybrid synergistic catalysis using enzymes. This study reveals that the synthesized FDH@ZIF‐8 nanocage‐structured hybrid (CSH) catalyst exhibits an improved catalytic ability of the enzymes and increases the hydrophobicity of the electrode and its affinity to CO2. Thus, CSH can trap CO2 and control its microenvironments. The CSH catalyst boosts the conversion rate of CO2 to formic acid (HCOOH) to 28 times higher than that when using pure FDH. The in situ attenuated total reflectance surface‐enhanced infrared absorption spectroscopy (ATR‐SEIRAS) spectra indicates that OCHO* is the key intermediate. Density functional theory (DFT) calculations show that CSH has extremely low overpotential and is particularly effective for producing formate. This protection architecture for enzymes considerably promotes their biological application under in vitro environments. [ABSTRACT FROM AUTHOR]

In this work, the single Rh atom anchored by N vacancy of C3N monolayer for CO oxidations has been studied by using first-principles calculations. The stability for a single Rh atom in N vacancy of C3N monolayer is detailed investigated. The sizeable binding energy and diffusion barrier of the Rh atom in the N vacancy and the ab initial molecule dynamic simulations at 400 K all verify that the Rh is stable at the N vacancy of the C3N monolayer. We also have examined the bi-molecule Eley–Rideal (ER) and Langmuir–Hinshelwood (LH) and the tri-molecule LH mechanisms on the Rh @ C3N. It is found that the barriers for the rate-limiting step for bi-molecule ER and LH are so significant (1.35, 1.15 eV), while for the tri-molecule LH mechanism, the barrier of the rate-limiting step is only 0.49 eV, which means the tri-molecule LH mechanism is more likely to occur at room temperature on the Rh @ C3N. Thus, our results will shed light on the future design for low-temperature CO oxidation using single-atom catalysts. [ABSTRACT FROM AUTHOR]

Inspired by the experimental synthesis of Pd-based single-atom alloy (SAA) catalysts which display high performance for reactions in the chemical industry. In this work, we have designed a Pd10Sb3 SAA alloy cluster as an efficient catalyst for CO oxidation. It is stable at 400 K for 3 ps under the ab-initio molecular dynamic simulation. Compared with Pd13, the Sb atom transfers electrons to the neighbour Pd atom, which induces its 4d states near the fermi level reduced much more. As a result, Pd10Sb3 show much weaker adsorptions of CO and O2. In addition, CO and O2 prefer to be adsorbed on the Pd site rather than on the Sb site. Thus, we have considered the full path for CO oxidation on the pure Pd site on Pd13 and Pd10Sb3 clusters. Compared with Pd13, on Pd10Sb3 the barrier of the rate-limiting step, that is the peroxide-like OO-CO intermediate formation, decreases by 0.54 eV which indicates Pd10Sb3 can be a potential catalyst for CO oxidation. [ABSTRACT FROM AUTHOR]

Objective: This study assessed the characteristics of intravenous thrombolysis (IVT) with respect to early neurological deterioration (END) and functional outcome in mild ischemic stroke patients. Methods: Data were obtained from acute mild ischemic stroke patients (defined as having a National Institute of Health Stroke Score (NIHSS) ≤ 5) treated with IVT in our hospital from July 2017 to December 2020. END was defined as the NIHSS increased ≥1 over the baseline at 24 h after IVT. A modified Rankin scale (mRS) ≤ 1 at 3 months was considered as a favorable outcome, and an mRS ≥2 at 3 months was an unfavorable outcome. Results: Two hundred thirty-three acute mild ischemic stroke patients (all patients underwent MRI and DWI restriction) with IVT were included in this study. Thirty-one patients experienced END, and 57 patients experienced an unfavorable outcome at 3 months. With multivariate analysis, END was associated with an elevated baseline systolic blood pressure (SBP) (OR = 1.324, 95% CI, 1.053–1.664, p = 0.016) and coronary heart disease (OR = 4.933, 95% CI, 1.249–19.482, p = 0.023). An unfavorable outcome at 3 months after IVT was independently associated with a baseline elevated SBP (OR = 1.213, 95% CI, 1.005–1.465, p = 0.045), baseline NIHSS (OR = 1.515, 95% CI, 1.186–1.935, p = 0.001), prior hyperlipemia (OR = 3.065, 95% CI, 1.107–8.482, p = 0.031), cardioembolic stroke (OR = 0.323, 95% CI, 0.120–0.871, p = 0.025), and END at 24 h (OR = 4.531, 95% CI, 1.950–10.533, p < 0.001) in mild ischemic stroke patients. Conclusion: In mild ischemic stroke patients with IVT, an elevated baseline SBP and coronary heart disease were associated with END. The elevated baseline SBP, baseline NIHSS, a history of prior hyperlipemia, cardioembolic stroke, and END at 24 h after IVT were useful in predicting an unfavorable outcome at 3 months. [ABSTRACT FROM AUTHOR]

Electrochemical reduction of carbon dioxide (ERCO2) to low-carbon fuel and useful chemicals, which can simultaneously store renewable energy and recover CO2 in a green manner, has proven to be a viable energy storage and conversion strategy. However, there is always a technical bottleneck in preparation of highly active, selective and stable catalysts. In this work, we hydrothermally synthesized a new type of bismuth-based organic framework (Bi–MOF) and carefully investigated it as the catalyst for ERCO2. All the samples exhibited excellent performance and the optimized one (i.e. Bi-BTC-D) achieved a high formate Faraday efficiency (FE) up to 95.5% at −0.86 VRHE and a current density of −11.2 mA cm−2. Moreover, the FE has been maintained over 90.0% after 12 hours of continuous electrolysis without significant reduction. The measurement results demonstrated that the excellent performance can be attributed to the special structure of Bi-BTC-D. DFT calculations show that the Bi site of Bi-BTC-D is highly efficient for formate production with very low overpotentials. The great potential of using a Bi–MOF as a highly stable, molecularly tunable catalytic material for ERCO2 is confirmed. [ABSTRACT FROM AUTHOR]

Sn‐based electrocatalysts are promising for the electrochemical CO2 reduction reaction (CO2RR), but suffer from poor activity and selectivity. A hierarchical structure composed of ultrathin SnOx nanosheets anchored on the surface of the commercial multiwalled carbon nanotubes (MWCNTs) is synthesized by a simple hydrothermal process. The electrocatalytic performance can be further tuned by functionalization of the MWCNTs with COOH, NH2, and OH groups. Both SnOx@MWCNTs−COOH and SnOx@MWCNTs−NH2 show excellent catalytic activity for CO2RR with nearly 100 % selectivity for C1 products (formate and CO). SnOx@MWCNTs−COOH has favorable formate selectivity with a remarkably high faradaic efficiency (FE) of 77 % at −1.25 V versus standard hydrogen electrode (SHE) and a low overpotential of 246 mV. However, SnOx@MWCNTs−NH2 manifests increased selectivity for CO with higher current density. Density functional theory calculations and experimental studies demonstrate that the interaction between Sn species and functional groups play an important role in the tuning of the catalytic activity and selectivity of these functionalized electrocatalysts. SnOx@MWCNTs−COOH and SnOx@MWCNTs−NH2 both effectively inhibit the hydrogen evolution reaction and prove stable without any significant degradation over 20 h of continuous electrolysis at −1.25 V versus SHE. Stay tuned: A CO2 reduction catalyst is developed with ultrathin SnOx nanosheets anchored on the surface of commercial multiwalled carbon nanotubes functionalized with −COOH, −NH2, or −OH. The link between the functional groups and catalytic performance is elucidated by DFT calculations and experimental studies, aiding the development of highly efficient carbon‐supported electrocatalysts by engineering the surface of the carbon support at a molecular level. [ABSTRACT FROM AUTHOR]

The adsorption and activation of O2 is regarded as the first critical step for the oxygen reduction reaction (ORR), and catalysts with a high performance toward O2 adsorption and activation would provide a theoretical foundation for further investigations. Here, we have studied the adsorption and electronic properties as well as the catalytic activities of group 9–11 single metal atoms deposited on NbC(001), denoted M/NbC(001). According to the location of the d-band centers and the frontier molecular orbital analysis, single metals of Co, Rh, Ir and Ni on NbC(001) exhibit higher activities than other metals (Pd, Pt, Cu, Ag and Au). The quite different catalytic activities of M/NbC(001) may be attributed to the differences in their electro-negativities and work-functions. Meanwhile, the reasonable stabilities of Co, Rh, Ir and Ni on NbC(001) were clarified by investigating the agglomeration resistance and oxidation resistance, and the results indicate that Co and Ni have poor oxidative stability, and Rh and Ir are antioxidants on NbC(001). Further research into the adsorption and activation of O2 confirmed the outstanding properties of Rh/NbC(001) and Ir/NbC(001), which may provide great opportunities to find alternative catalysts. [ABSTRACT FROM AUTHOR]

The adsorption and dissociation reactions of H2S on TiC(001) are investigated using first-principles density functional theory calculations. The geometric and electronic structures of the adsorbed S-based species (including H2S, SH and S) on TiC(001) are analyzed in detail. It is found that the H2S is bound weakly, while SH and atomic S are bound strongly on the TiC(001) surface. The transition state calculations show that the formation of SH from H2S (H2S → SH + H) is very easy, while the presence of a co-adsorbed H will inhibit the further dissociation of SH (SH + H → S + H + H). In contrast, the hydrogenation of the adsorbed SH is rather easy (SH + H → H2S). Therefore, the dissociative SH can be removed via the hydrogenation reaction. It is concluded that it is difficult for H2S to dissociate completely to form atomic S and poison the TiC surface. The results will further provide understanding of the mechanism of the sulfur tolerance of the TiC anode of proton exchange membrane fuel cells (PEMFCs). [ABSTRACT FROM AUTHOR]

The tolerance of sulfur poisoning of α-Mo2C(0001) surfaces with different Pt coverages is investigated combining the density functional theory (DFT) results with thermodynamics data using the ab initio atomistic thermodynamic method. It is found that on Mo2C(0001), Pt clusters tend to form two dimensional planar structures instead of aggregating. The clean Mo2C(0001) surface interacts with sulfides very strongly and is susceptible to sulfur poisoning. With increasing the coverage of Pt on the Mo2C surface, the interaction between sulfur and substrate is weakened. The sulfur tolerance ability increases in the order of Mo2C ≈ Pt1/Mo2C ＜ Pt4/Mo2C ＜ Pt8/Mo2C, where the coverage of Pt on the Mo2C plays a very effective role. The results provide theoretical guidance for designing Mo2C based catalysts with high activity and high sulfur resistance. [ABSTRACT FROM AUTHOR]

Surface-deposited sediment in urban area is an essential environmental medium for assessing heavy metal contamination. A total of 10 sampling trips were conducted to collect road-deposited and roof-deposited sediments for the comparison of nickel (Ni), copper (Cu), cadmium (Cd), lead (Pb), zinc (Zn), and chromium (Cr) contamination characteristics. Results indicated that roof sediment appeared to have a finer size distribution than road sediments. Roof sediment indicated higher metal concentration and lower surface loading than road sediment. The impact of particle size on heavy metal contamination was quantified by using the developed pioneering term of finer particle effect factor; it differed according to surface types and grain size fraction. Particles in individual grain size fraction showed different contribution to the surface loading for bulk sediments. No consistent trend was found for the grain size fraction loading along with grain size for the studied heavy metals for road sediments. In contrast, an asymmetric 'W' trend was observed for the roof sediments, and it had the following results: Fraction of <63 and 250-500 μm showed higher loading, while fraction of 90-125 and >850 μm indicated the smaller loading. Findings above facilitated the appropriate management practice selection for the treatment of surface-deposited sediments. [ABSTRACT FROM AUTHOR]

Novel Ag@C nanocables are successfully synthesized through a hydrothermal self-assembly process, and employed as the support material to fabricate a uniformly distributed Pt nanoparticle electrocatalyst (Pt/Ag@C) for glycerol oxidation reaction (GOR). Electrochemical measurements demonstrate that this Pt/Ag@C catalyst can have both superior electrocatalytic GOR activity and stability, confirming that the Ag@C nanocables should be a great material for supporting the catalyst. Theoretical calculations are also carried out for fundamental understanding of the enhanced catalytic performance of this Pt/Ag@C catalyst. The results show that this Pt/Ag@C catalyst should be a great candidate as the anode catalyst for direct glycerol fuel cells. [ABSTRACT FROM AUTHOR]

The adsorption and dissociation of O2 on the core–shell M@Pd nanowires (M = 3d, 4d, 5d transition metals) are studied using the first-principles density functional method. Suitable core atoms are determined based on the stability of the core–shell NWs and their efficiency for O2 dissociation. With the consideration of the stability and cost, we found that Fe, Co, Ni, Cu, Ru, Ir atoms have lower price than Pd and favor at the core even with O adatom at the surface. The formed M@Pd core–shell nanowires are active for O2 dissociation with activation barriers no larger than 0.25 eV. The results may serve as a guide for the design of efficient Pd-based nanocatalysts for O2 dissociation. [ABSTRACT FROM AUTHOR]

The dissociation barriers of O and the adsorption energies of atomic O on the icosahedron M@Pd12, double icosahedron M2@Pd17 core-shell nanoclusters, and the M@Pd (M = Mn, Fe, Co, Ni, Cu, Pd) nanowires (NWs) are studied. It is found that the M@Pd NWs can probably serve as good catalysts for oxygen reduction reaction with both small O dissociation energy (0.10-0.23 eV) and O adsorption energy (1.19-1.28 eV). The reasons for the advantage of the M@Pd NWs are discussed in detail. [ABSTRACT FROM AUTHOR]

The mechanisms for the resistance to sulfur poisoning at the triple phase boundary (TPB) of the Ni/yttria-stabilized zirconia (YSZ) system treated with Sn vapor are studied using the first-principles method based on density functional theory. Models with Sn dopant or adsorbate are proposed. It is found that the TPB model of the Ni/YSZ system with Sn dopant in Ni can to some extent restrain the diffusion of sulfur from the Ni part to the interface O vacancy by forcing the sulfur atom to diffuse along a longer path, which increases the time for which sulfur remains at the Sn doped Ni surface and allows the O ion to diffuse to the O vacancy at the interface. Once the O ion diffuses to the O vacancy, it forms interface O2−, which repels the sulfur adsorbate and eliminates the sulfur poisoning. However, as the barriers of sulfur diffusion to the vacancy are still small (0.25 eV or smaller), the Sn dopant in Ni does not efficiently eliminate the sulfur poisoning at the TPB. In contrast, the TPB model of the Ni/YSZ system with an Sn adatom on the Ni can form a physical barrier and prevent effectively sulfur diffusion to the O vacancy at the interface. The diffusion barriers are as large as 1.41 eV, which therefore eliminates the sulfur poisoning at the TPB. The results give a detailed dynamic picture of the mechanism of the high tolerance to sulfur poisoning of the Ni/YSZ anode at the TPB after the pre-exposures to metallic tin vapor. [ABSTRACT FROM AUTHOR]

Palladium (Pd) nanocatalysts with high energy facets {110} supported on flower-like hydroxyapatite (F-HAP) were successfully prepared. Based on the experimental data and theoretical calculations, it was found that the O2 dissociation on Pd {110} facets could be key to the performance of Pd nanoparticles in the solvent-free selective oxidation of alcohols. [ABSTRACT FROM AUTHOR]