Selective binding and periodic arrangement of magic boron clusters on monolayer borophene.

The synthesis and characterization of small boron clusters with unique size and regular arrangement are crucial for boron chemistry and two-dimensional borophene materials. In this study, together with theoretical calculations, the joint molecular beam epitaxy and scanning tunneling microscopy experiments achieve the formation of unique B5 clusters on monolayer borophene (MLB) on a Cu(111) surface. The B5 clusters tend to selectively bind to specific sites of MLB with covalent boron-boron bonds in the periodic arrangement, which can be ascribed to the charge distribution and electron delocalization character of MLB and also prohibits nearby co-adsorption of B5 clusters. Furthermore, the close-packed adsorption of B5 clusters would facilitate the synthesis of bilayer borophene, exhibiting domino effect-like growth mode. The successful growth and characterization of uniform boron clusters on a surface enrich the boron-based nanomaterials and reveal the essential role of small clusters during the growth of borophene.

A Volcano Correlation between Catalytic Activity for Sulfur Reduction Reaction and Fe Atom Count in Metal Center.

Sulfur reduction reaction (SRR) facilitates up to 16 electrons, which endows lithium-sulfur (Li-S) batteries with a high energy density that is twice that of typical Li-ion batteries. However, its sluggish reaction kinetics render batteries with only a low capacity and cycling life, thus remaining the main challenge to practical Li-S batteries, which require efficient electrocatalysts of balanced atom utilization and site-specific requirements toward highly efficient SRR, calling for an in-depth understanding of the atomic structural sensitivity for the catalytic active sites. Herein, we manipulated the number of Fe atoms in iron assemblies, ranging from single Fe atom to diatomic and triatomic Fe atom groupings, all embedded within a carbon matrix. This led to the revelation of a "volcano peak" correlation between SRR catalytic activity and the count of Fe atoms at the active sites. Utilizing operando X-ray absorption and X-ray diffraction spectroscopies, we observed that polysulfide adsorption-desorption and electrochemical conversion kinetics varied up and down with the incremental addition of even a single iron atom to the catalyst's metal center. Our results demonstrate that the metal center with exactly two iron atoms represents the optimal configuration, maximizing atom utility and adeptly handling the conversion of varied intermediate sulfur species, rendering the Li-S battery with a high areal capacity of 23.8 mAh cm-2 at a high sulfur loading of 21.8 mg cm-2. Our results illuminate the pivotal balance between atom utilization and site-specific requirements for optimal electrocatalytic performance in SRR and diverse electrocatalytic reactions.

Metal-Sulfur Interfaces as the Primary Active Sites for Catalytic Hydrogenations.

The determination of catalytically active sites is crucial for understanding the catalytic mechanism and providing guidelines for the design of more efficient catalysts. However, the complex structure of supported metal nanocatalysts (e.g., support, metal surface, and metal-support interface) still presents a big challenge. In particular, many studies have demonstrated that metal-support interfaces could also act as the primary active sites in catalytic reactions, which is well elucidated in oxide-supported metal nanocatalysts but is rarely reported in carbon-supported metal nanocatalysts. Here, we fill the above gap and demonstrate that metal-sulfur interfaces in sulfur-doped carbon-supported metal nanocatalysts are the primary active sites for several catalytic hydrogenation reactions. A series of metal nanocatalysts with similar sizes but different amounts of metal-sulfur interfaces were first constructed and characterized. Taking Ir for quinoline hydrogenation as an example, it was found that their catalytic activities were proportional to the amount of the Ir-S interface. Further experiments and density functional theory (DFT) calculations suggested that the adsorption and activation of quinoline occurred on the Ir atoms at the Ir-S interface. Similar phenomena were found in p-chloronitrobenzene hydrogenation over the Pt-S interface and benzoic acid hydrogenation over the Ru-S interface. All of these findings verify the predominant activity of metal-sulfur interfaces for catalytic hydrogenation reactions and contribute to the comprehensive understanding of metal-support interfaces in supported nanocatalysts.

Reticular Ratchets for Directing Electrochemiluminescence.

Electrochemiluminescence (ECL) involves charge transfer between electrochemical redox intermediates to produce an excited state for light emission. Ensuring precise control of charge transfer is essential for decoding ECL fundamentals, yet guidelines on how to achieve this for conventional emitters remain unexplored. Molecular ratchets offer a potential solution, as they enable the directional transfer of energy or chemicals while impeding the reverse movement. Herein, we designed 10 pairs of imine-based covalent organic frameworks as reticular ratchets to delicately manipulate the intrareticular charge transfer for directing ECL transduction from electric and chemical energies. Aligning the donor and acceptor (D-A) directions with the imine dipole effectively facilitates charge migration, whereas reversing the D-A direction impedes it. Notably, the ratchet effect of charge transfer directionality intensified with increasing D-A contrast, resulting in a remarkable 680-fold improvement in the ECL efficiency. Furthermore, dipole-controlled exciton binding energy, electron/hole decay kinetics, and femtosecond transient absorption spectra identified the electron transfer tendency from the N-end toward the C-end of reticular ratchets during ECL transduction. An exponential correlation between the ECL efficiency and the dipole difference was discovered. Our work provides a general approach to manipulate charge transfer and design next-generation electrochemical devices.

Highly Crystalline Iridium-Nickel Nanocages with Subnanopores for Acidic Bifunctional Water Splitting Electrolysis.

Developing efficient bifunctional materials is highly desirable for overall proton membrane water splitting. However, the design of iridium materials with high overall acidic water splitting activity and durability, as well as an in-depth understanding of the catalytic mechanism, is challenging. Herein, we successfully developed subnanoporous Ir3Ni ultrathin nanocages with high crystallinity as bifunctional materials for acidic water splitting. The subnanoporous shell enables Ir3Ni NCs optimized exposure of active sites. Importantly, the nickel incorporation contributes to the favorable thermodynamics of the electrocatalysis of the OER after surface reconstruction and optimized hydrogen adsorption free energy in HER electrocatalysis, which induce enhanced intrinsic activity of the acidic oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Together, the Ir3Ni nanocages achieve 3.72 A/mgIr(η=350 mV) and 4.47 A/mgIr(η=40 mV) OER and HER mass activity, which are 18.8 times and 3.3 times higher than that of commercial IrO2 and Pt, respectively. In addition, their highly crystalline identity ensures a robust nanostructure, enabling good catalytic durability during the oxygen evolution reaction after surface oxidation. This work provides a new revenue toward the structural design and insightful understanding of metal alloy catalytic mechanisms for the bifunctional acidic water splitting electrocatalysis.

Blood pressure stratification for predicting liver fibrosis risk in metabolic dysfunction associated fatty liver disease.

INTRODUCTION AND OBJECTIVES: The optimal blood pressure (BP) range for patients with metabolic dysfunction-associated fatty liver disease (MAFLD) is currently unknown. This study aimed to explore the relationship between stratified BP levels and MAFLD progression. PATIENTS AND METHODS: The data of adults who underwent yearly health check-ups were screened to establish both a cross-sectional and a 6-year longitudinal cohort of individuals with MAFLD. BP was classified into the following categories optimal, normal, high-normal, and hypertension. Liver fibrosis was diagnosed with fibrosis-4 (FIB-4) score, nonalcoholic fatty liver disease fibrosis score (NFS), and aspartate aminotransferase-to-platelet ratio index (APRI). RESULTS: A total of 10,232 individuals were included in the cross-sectional cohort. In the MAFLD population, individuals with liver fibrosis had significantly higher BP levels and hypertension prevalence (P < 0.001) than those without. Furthermore, liver fibrosis score was significantly associated with BP levels (P < 0.001). In the 6-year longitudinal cohort of 3661 individuals with MAFLD without liver fibrosis, the incidence rates of liver fibrosis increased with increasing BP levels as follows optimal=11.20%, normal=13.90%, high-normal=19.50%, hypertension=26.20% (log-rank 22.205; P < 0.001). Cox regression analysis showed that both baseline high-normal BP (hazard ratio [HR], 1.820; P=0.019) and hypertension (HR, 2.656; P < 0.001) were predictive of liver fibrosis. CONCLUSIONS: BP stratification may be useful in predicting the progression of MAFLD. Individuals having MAFLD with concurrent hypertension or high-normal BP are at a higher risk of liver fibrosis. These findings may provide a criteria for early intervention of MAFLD to prevent liver fibrosis.

Clinical effects of multi-oil versus pure soybean oil-based lipid emulsions for preterm infants: An observational study.

BACKGROUND AND OBJECTIVES: Conventional soybean oil-based intravenous lipid emulsions (SO-ILEs) have high polyunsaturated fatty acid (PUFA) contents and phytosterols that may have adverse effects in preterm infants. Recently, the multi-oil-based intravenous lipid emulsion (MO-ILE), SMOFlipid, has been widely utilized in the neonatal intensive care unit (NICU), but significant benefits over SO-ILEs in low gestational age neonates have yet to be demonstrated. This study was performed to compare the effects of the SO-ILE, Intralipid, and the MO-ILE, SMOFlipid, on neonatal health outcomes in preterm infants. METHODS AND STUDY DESIGN: We performed a retrospective review of preterm infants born at gestational week (GW) <32 receiving parenteral nutrition for longer durations (≥14 d) in the NICU between 2016 and 2021. The primary aim of this study was to investigate differences in morbidity between preterm infants receiving SMOFlipid and Intralipid. RESULTS: A total of 262 preterm infants were included in the analysis, with 126 receiving SMOFlipid and 136 receiving Intralipid. The SMOFlipid group had lower rates of ROP (23.8% vs 37.5%, respectively; p=0.017), although the rate of ROP was not different in multivariate regression analysis. The length of hospi-tal stay was significantly shorter in the SMOFlipid than SO-ILE group (median [IQR]=64.8 [37] vs 72.5 [49] days; p<0.001). CONCLUSIONS: The use of SMOFlipid as the lipid emulsion was associated with higher clinical efficacy than SO-ILE in preterm infants.

Enhanced Curie Temperature of Two-Dimensional Cr(II) Aromatic Heterocyclic Metal-Organic Framework Magnets via Strengthened Orbital Hybridization.

Two-dimensional (2D) metal-organic frameworks (MOFs) with room-temperature magnetism are highly desirable but challenging due to the weak superexchange interaction between metal atoms. For this purpose, strengthening the hybridization between metal ion and organic linkage presents an experiment-feasible chemical solution to enhance the Curie temperature. Here, we report three 2D Cr(II) aromatic heterocyclic MOF magnets with enhanced Curie temperature by bridging Cr(II) ions with pyrazine, 1,4-diphosphinine, and 1,4-diarsenin linkers, i.e., Cr(pyz)2, Cr(diphos)2, and Cr(diarse)2, and using first-principles calculations. Our results show that Cr(pyz)2, Cr(diphos)2, and Cr(diarse)2 are ferrimagnetic semiconductors. In particular, the Curie temperature of Cr(pyz)2 is estimated to be about 344 K and could be enhanced to 512 and 437 K in Cr(diphos)2 and Cr(diarse)2 by strengthening the hybridization between Cr ions and organic linkers via d-π* direct exchange interaction. This study presents a prototype to obtain room-temperature magnetism in 2D Cr(II)-based MOF magnets for nanoscale spintronics applications.

Electric-Field Tunable Magnetism in van der Waals Bilayers with A-Type Antiferromagnetic Order: Unipolar versus Bipolar Magnetic Semiconductor.

Uncovering the physics behind the electrical manipulation of low-dimensional magnetic materials remains a fundamental issue in practical application of nanoscale spintronics. Here, we propose a strategy to transform A-type antiferromagnetic (AFM) semiconductors into asymmetric AFM unipolar or bipolar magnetic semiconductors by applying perpendicular electric fields in van der Waals bilayer systems. Electric fields lifting energy levels of electrons within same spin channel from consistent layers in opposite direction enables unipolar magnetic semiconductor, whereas electrons within opposite spin channel enable bipolar magnetic semiconductor. A comprehensive study demonstrates this discrepancy originates from spatial distributions of spin density of valence band and conduction band edges in two layers of systems. The electric field induced unipolar or bipolar magnetic semiconducting behavior represents great potential of nanoscale AFM spintronics for information storage and processing.

Author Correction: Eliminating dissolution of platinum-based electrocatalysts at the atomic scale.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Eliminating dissolution of platinum-based electrocatalysts at the atomic scale.

A remaining challenge for the deployment of proton-exchange membrane fuel cells is the limited durability of platinum (Pt) nanoscale materials that operate at high voltages during the cathodic oxygen reduction reaction. In this work, atomic-scale insight into well-defined single-crystalline, thin-film and nanoscale surfaces exposed Pt dissolution trends that governed the design and synthesis of durable materials. A newly defined metric, intrinsic dissolution, is essential to understanding the correlation between the measured Pt loss, surface structure, size and ratio of Pt nanoparticles in a carbon (C) support. It was found that the utilization of a gold (Au) underlayer promotes ordering of Pt surface atoms towards a (111) structure, whereas Au on the surface selectively protects low-coordinated Pt sites. This mitigation strategy was applied towards 3 nm Pt3Au/C nanoparticles and resulted in the elimination of Pt dissolution in the liquid electrolyte, which included a 30-fold durability improvement versus 3 nm Pt/C over an extended potential range up to 1.2 V.

Meta-analysis of vitamin D and lung function in patients with asthma.

BACKGROUND: There is growing literature suggesting a link between vitamin D and asthma lung function, but the results from systematic reviews are conflicting. We conducted this meta-analysis to investigate the relation between serum vitamin D and lung function in asthma patients. METHODS: Major databases, including OVID, MEDLINE, Web of Science and PUBMED, were searched until 10th October 2018. All published observational studies related to vitamin D and asthma were extracted. All meta-analyses were performed using Review Manager 5.3.5. RESULTS: This quantitative synthesis found that asthma patients with low vitamin D levels had lower forced expiratory volume In 1 s (FEV1) (mean difference (MD) = - 0.1, 95% CI = - 0.11 to - 0.08,p < 0.01;I2 = 49%, p = 0.12) and FEV1% (MD = - 10.02, 95% CI = - 11 to - 9.04, p < 0.01; I2 = 0%, p = 0.82) than those with sufficient vitamin D levels. A positive relation was found between vitamin D and FEV1 (r = 0.12, 95% CI = 0.04 to 0.2, p = 0.003; I2 = 59%,p = 0.01), FEV1% (r = 0.19, 95% CI = 0.13 to 0.26, p < 0.001; I2 = 42%, p = 0.11), forced vital capacity (FVC) (r = 0.17, 95% CI = 0.00 to 0.34, p = 0.05; I2 = 60%, p = 0.04), FEV1/FVC (r = 0.4, 95% CI = 0.3 to 0.51, p < 0.001; I2 = 48%, p = 0.07), and the asthma control test (ACT) (r = 0.33, 95% CI = 0.2 to 0.47, p < 0.001; I2 = 0%, p = 0.7). Subgroup analysis indicated that the positive correlation between vitamin D and lung function remained significant in both children and adults. CONCLUSIONS: Our meta-analysis suggested that serum vitamin D levels may be positively correlated with lung function in asthma patients. Future comprehensive studies are required to confirm these relations and to elucidate potential mechanisms.

Kinetic Strategies for the Formation of Graphyne Nanowires via Sonogashira Coupling on Ag(111).

The selection of a reaction pathway with high energy barrier in a multipath on-surface reaction system has been challenging. Herein, we report the successful control of the reaction system of 1,1'-biphenyl-4-bromo-4'-ethynyl (BPBE) on Ag(111), in which three coupling reactions (Glaser, Ullman, Sonogashira) are involved. Either graphdiyne (GDY) or graphyne (GY) nanowires can be formed by distinct kinetic strategies. As the energetically favorable pathway, the formation of a GDY nanowire is achieved by hierarchical activation of Glaser (with lowest energy barrier) and Ullman coupling of BPBE. On the other hand, the formation of a GY nanowire originates from the high selectivity of the high-barrier Sonogashira coupling, whose indispensable kinetic parameters are high surface temperature, low molecular coverage, and low precursor evaporation rate, as derived from a series of control experiments. This work achieves the fabrication of GY nanowires via on-surface Sonogashira coupling for the first time and reveals mechanistic control strategies for potential syntheses of other functional nanostructures via cross-couplings on surfaces.

Promoting Active Species Generation by Electrochemical Activation in Alkaline Media for Efficient Electrocatalytic Oxygen Evolution in Neutral Media.

In this study, by using dicobalt phosphide nanoparticles as precatalysts, we demonstrated that electrochemical activation of metallic precatalysts in alkaline media (comparing with directly electrochemical activation in neutral media) could significantly promote the OER catalysis in neutral media, specifically realizing a 2-fold enhanced activity and meanwhile showing a greatly decreased overpotential of about 100 mV at 10 mA cm-2. Compared directly with electrochemical activation in neutral media, the electrochemical activation in harsh alkaline media could easily break the strong Co-Co bond and promote active species generation on the surface of metallic Co2P, thus accounting for the enhancement of neutral OER activity, which is also evidenced by HRTEM and the electrochemical double-layer capacitance measurement. The activation of electrochemical oxidation of metallic precatalysts in alkaline media enhanced neutral OER catalysis could also be observed on CoP nanoparticles and Ni2P nanoparticles, suggesting this is a generic strategy. Our work highlights that the activation of electrochemical oxidation of metallic precatalysts in alkaline media would pave new avenues for the design of advanced neutral OER electrocatalysts.

Half-Metallicity in One-Dimensional Metal Trihydride Molecular Nanowires.

The development of one-dimensional (1D) molecular nanowires with high spin-polarization is important for both fundamental research and practical applications in nanoscale spintronics. Herein, we report new 1D metal trihydride molecular nanowires MH3 (M = Sc, Cr, Mn, and Co) with versatile magnetic properties on the basis of first-principles calculations and molecular assembly of their molecular motifs. Among the 1D nanowires considered, CrH3, MnH3, and CoH3 are either antiferromagnetic or ferromagnetic in their ground states. In particular, CoH3 nanowire is a half-metal, which ideally could provide 100% spin-polarized currents. Moreover, carrier doping in MnH3 nanowire can induce a transition from ferromagnetic metal to half-metal. Strong metal-metal interaction in 1D MH3 nanowires is responsible to versatile magnetic properties and high Curie temperature. Born-Oppenheimer molecular dynamics simulation indicates that these nanowires are stable at elevated temperature. In particular, the ScH3 nanowire appears to have the highest structural stability at temperature 1200 K. These novel properties of 1D MH3 nanowires render their potential applications in nanoscale spintronics.

High-Performance Rh2P Electrocatalyst for Efficient Water Splitting.

The search for active, stable, and cost-efficient electrocatalysts for hydrogen production via water splitting could make a substantial impact on energy technologies that do not rely on fossil fuels. Here we report the synthesis of rhodium phosphide electrocatalyst with low metal loading in the form of nanocubes (NCs) dispersed in high-surface-area carbon (Rh2P/C) by a facile solvo-thermal approach. The Rh2P/C NCs exhibit remarkable performance for hydrogen evolution reaction and oxygen evolution reaction compared to Rh/C and Pt/C catalysts. The atomic structure of the Rh2P NCs was directly observed by annular dark-field scanning transmission electron microscopy, which revealed a phosphorus-rich outermost atomic layer. Combined experimental and computational studies suggest that surface phosphorus plays a crucial role in determining the robust catalyst properties.

Relationship of serum uric acid level with non-alcoholic fatty liver disease and its inflammation progression in non-obese adults.

AIM: This study aimed to evaluate the relationship between serum uric acid (SUA) level and non-alcoholic fatty liver disease (NAFLD) in non-obese adults. METHODS: A cross-sectional study was carried out among 4098 adults, including 1936 non-obese and 2162 obese individuals. An additional 93 non-obese adults with biopsy-proven NAFLD were also included. RESULTS: The overall prevalence of NAFLD was 39.51% in the study group, and 14.88% in non-obese adults. The NAFLD patients had significantly higher SUA levels than controls in both men and women. The non-obese group had a higher NAFLD risk with increased SUA levels than the obese group, with odd ratios (95% confidence interval) of 2.559 (1.870-3.503) and 1.692 (1.371-2.087), respectively. In 93 non-obese adults with biopsy-proven NAFLD, SUA levels were significantly higher in those with non-alcoholic steatohepatitis. The prevalence of non-alcoholic steatohepatitis and lobule inflammation tended to increase to 57.58% and 66.67% as the SUA level increased to the fourth quartile. Subjects with hyperuricemia had significantly higher NAFLD activity scores and more serious lobule inflammation than the normal group. CONCLUSION: Non-obese adults have higher NAFLD risk with increased SUA levels than obese individuals, and the inflammation progression of NAFLD is associated with increased SUA level in non-obese subjects.

Highly Selective Synthesis of cis-Enediynes on a Ag(111) Surface.

Cis-enediyne-type compounds have received much attention as potent antitumor antibiotics. The conventional synthesis of cis-enediynes in solution typically involves multiple steps and various side reactions. For the first time, selective one-step synthesis of cis-enediyne from a single reactant is reported on a Ag(111) surface with a yield up to 90 %. High selectivity for the formation of cis-enediyne originates from the steric effect posed by weak intermolecular interactions, which protect the cis-enediyne from further reaction. A series of comparative experiments and DFT-based transition-state calculations support the findings. The described synthetic approach for directing reaction pathways on-surface may illuminate potential syntheses of other unstable organic compounds.

New approach to fully ordered fct-FePt nanoparticles for much enhanced electrocatalysis in acid.

Fully ordered face-centered tetragonal (fct) FePt nanoparticles (NPs) are synthesized by thermal annealing of the MgO-coated dumbbell-like FePt-Fe3O4 NPs followed by acid washing to remove MgO. These fct-FePt NPs show strong ferromagnetism with room temperature coercivity reaching 33 kOe. They serve as a robust electrocatalyst for the oxygen reduction reaction (ORR) in 0.1 M HClO4 and hydrogen evolution reaction (HER) in 0.5 M H2SO4 with much enhanced activity (the most active fct-structured alloy NP catalyst ever reported) and stability (no obvious Fe loss and NP degradation after 20 000 cycles between 0.6 and 1.0 V (vs RHE)). Our work demonstrates a reliable approach to FePt NPs with much improved fct-ordering and catalytic efficiency for ORR and HER.

Superparamagnetic Reduced Graphene Oxide with Large Magnetoresistance: A Surface Modulation Strategy.

The graphene system is actively pursued in spintronics for its nontrivial sp electron magnetism and its potential for the flexible surface chemical tuning of magnetoelectronic functionality. The magnetoresistance (MR) of graphene can be effectively tuned under high magnetic fields at cryogenic temperatures, but it remains a challenge to achieve sensitive magnetoelectric response under ambient conditions. We report the use of surface modulation to realize superparamagnetism in reduced graphene oxide (rGO) with sensitive magnetic field response. The superparamagnetic rGO was obtained by a mild oxidation process to partially remove the thiol groups covalently bound to the carbon framework, which brings about large low-field negative MR at room temperature (-8.6 %, 500 Oe, 300 K). This strategy provides a new approach for optimizing the intrinsic magnetoelectric properties of two-dimensional materials.