Regulating the Electron Distribution of Metal-Oxygen for Enhanced Oxygen Stability in Li-rich Layered Cathodes.

Li-rich Mn-based layered oxides (LLO) hold great promise as cathode materials for lithium-ion batteries (LIBs) due to their unique oxygen redox (OR) chemistry, which enables additional capacity. However, the LLOs face challenges related to the instability of their OR process due to the weak transition metal (TM)-oxygen bond, leading to oxygen loss and irreversible phase transition that results in severe capacity and voltage decay. Herein, a synergistic electronic regulation strategy of surface and interior structures to enhance oxygen stability is proposed. In the interior of the materials, the local electrons around TM and O atoms may be delocalized by surrounding Mo atoms, facilitating the formation of stronger TM─O bonds at high voltages. Besides, on the surface, the highly reactive O atoms with lone pairs of electrons are passivated by additional TM atoms, which provides a more stable TM─O framework. Hence, this strategy stabilizes the oxygen and hinders TM migration, which enhances the reversibility in structural evolution, leading to increased capacity and voltage retention. This work presents an efficient approach to enhance the performance of LLOs through surface-to-interior electronic structure modulation, while also contributing to a deeper understanding of their redox reaction.

Nonadiabatic Charge Transfer within Photoexcited Nickel Porphyrins.

Metalloporphyrins with open d-shell ions can drive biochemical energy cycles. However, their utilization in photoconversion is hampered by rapid deactivation. Mapping the relaxation pathways is essential for elaborating strategies that can favorably alter the charge dynamics through chemical design and photoexcitation conditions. Here, we combine transient optical absorption spectroscopy and transient X-ray emission spectroscopy with femtosecond resolution to probe directly the coupled electronic and spin dynamics within a photoexcited nickel porphyrin in solution. Measurements and calculations reveal that a state with charge-transfer character mediates the formation of the thermalized excited state, thereby advancing the description of the photocycle for this important representative molecule. More generally, establishing that intramolecular charge-transfer steps play a role in the photoinduced dynamics of metalloporphyrins with open d-shell sets a conceptual ground for their development as building blocks capable of boosting nonadiabatic photoconversion in functional architectures through "hot" charge transfer down to the attosecond time scale.

Establishing a Rat Model of Pelvic Organ Prolapse with All Compartment Defects by Persistent Cervical Tension.

INTRODUCTION AND HYPOTHESIS: We hypothesized that applying cervical suction and persistent tension can develop a novel and efficient rat model of pelvic organ prolapse. METHODS: Fifteen rats underwent pilot testing to optimize the protocol. Sixteen rats were subjected to pelvic organ prolapse induction by cervical suction and constant traction, while five rats served as controls. The pelvic organ prolapse rats were assessed by a Rat Pelvic Organ Prolapse Quantification system at different time points, and their diet, urine, and stool were monitored for 21 days. The pelvic organ prolapse rats were also evaluated for urinary incontinence, urinary retention, leak point pressure, and vaginal histopathology at 21 days after operation. RESULTS: This rat model demonstrated pelvic floor prolapse in anatomic level, as well as physiological variations (urine incontinence, urinary retention) and pathological changes (collagen fracture, decreased collagen density). CONCLUSIONS: This is the first establishment of the pelvic organ prolapse rat model with all compartment defects, which provides a valuable tool for elucidating pelvic organ prolapse mechanisms and evaluating potential interventions.

Global, Regional, and National Burden of Myocarditis in 204 Countries and Territories From 1990 to 2019: Updated Systematic Analysis.

BACKGROUND: Myocarditis is characterized by high disability and mortality, and imposes a severe burden on population health globally. However, the latest global magnitude and secular trend of myocarditis burden have not been reported. OBJECTIVE: This study aimed to delineate the epidemiological characteristics of myocarditis burden globally for optimizing targeted prevention and research. METHODS: Based on the Global Burden of Disease Study 2019, the myocarditis burden from 1990 to 2019 was modeled using the Cause of Death Ensemble tool, DisMod-MR, and spatiotemporal Gaussian regression. We depicted the epidemiology and trends of myocarditis by sex, age, year, region, and sociodemographic index (SDI). R program version 4.2.1 (R Project for Statistical Computing) was applied for all statistical analyses, and a 2-sided P-value of <.05 was considered statistically significant. RESULTS: The number of incident cases (1,268,000) and deaths (32,450) associated with myocarditis in 2019 increased by over 1.6 times compared with the values in 1990 globally. On the other hand, the age-standardized incidence rate (ASIR) and age-standardized mortality rate (ASMR) decreased slightly from 1990 to 2019. The disability-adjusted life years (DALYs) decreased slightly in the past 3 decades, while the age-standardized DALY rate (ASDR) decreased greatly from 18.29 per 100,000 person-years in 1990 to 12.81 per 100,000 person-years in 2019. High SDI regions always showed a more significant ASIR. The ASIR slightly decreased in all SDI regions between 1990 and 2019. Middle SDI regions had the highest ASMR and ASDR in 2019. Low SDI regions had the lowest ASMR and ASDR in 2019. The age-standardized rates (ASRs) of myocarditis were higher among males than among females from 1990 to 2019 globally. All ASRs among both sexes had a downward trend, except for the ASMR among males, which showed a stable trend, and females had a more significant decrease in the ASDR than males. Senior citizens had high incident cases and deaths among both sexes in 2019. The peak numbers of DALYs for both sexes were noted in the under 1 age group in 2019. At the national level, the estimated annual percentage changes in the ASRs had significant negative correlations with the baseline ASRs in 1990. CONCLUSIONS: Globally, the number of incident cases and deaths associated with myocarditis have increased significantly. On the other hand, the ASRs of myocarditis showed decreasing trends from 1990 to 2019. Males consistently showed higher ASRs of myocarditis than females from 1990 to 2019 globally. Senior citizens gradually predominated in terms of myocarditis burden. Policymakers should establish targeted control strategies based on gender, region, age, and SDI; strengthen aging-related health research; and take notice of the changes in the epidemic characteristics of myocarditis.

RhoA vesicle trafficking-mediated transglutaminase 2 membrane translocation promotes IgA1 mesangial deposition in IgA nephropathy.

Transglutaminase 2 (TGase2) has been shown to contribute to the mesangial IgA1 deposition in a humanized mouse model of IgA nephropathy (IgAN), but the mechanism is not fully understood. In this study, we found that inhibition of TGase2 activity could dramatically decrease the amount of polymeric IgA1 (pIgA1) isolated from patients with IgAN that interacts with human mesangial cells (HMC). TGase2 was expressed both in the cytosol and on the membrane of HMC. Upon treatment with pIgA1, there were more TGase2 recruited to the membrane. Using a cell model of mesangial deposition of pIgA1, we identified 253 potential TGase2-associated proteins in the cytosolic fraction and observed a higher concentration of cellular vesicles and increased expression of Ras homolog family member A (RhoA) in HMC after pIgA1 stimulation. Both the amount of pIgA1 deposited on HMC and membrane TGase2 level were decreased by inhibition of the vesicle trafficking pathway. Mechanistically, TGase2 was found to be coprecipitated with RhoA in the cellular vesicles. Membrane TGase2 expression was greatly increased by overexpression of RhoA, while it was reduced by knockdown of RhoA. Our in vitro approach demonstrated that TGase2 was transported from the cytosol to the membrane through a RhoA-mediated vesicle-trafficking pathway that can facilitate pIgA1 interaction with mesangium in IgAN.

Misoriented high-entropy iridium ruthenium oxide for acidic water splitting.

Designing an efficient catalyst for acidic oxygen evolution reaction (OER) is of critical importance in manipulating proton exchange membrane water electrolyzer (PEMWE) for hydrogen production. Here, we report a fast, nonequilibrium strategy to synthesize quinary high-entropy ruthenium iridium-based oxide (M-RuIrFeCoNiO2) with abundant grain boundaries (GB), which exhibits a low overpotential of 189 millivolts at 10 milliamperes per square centimeter for OER in 0.5 M H2SO4. Microstructural analyses, density functional calculations, and isotope-labeled differential electrochemical mass spectroscopy measurements collectively reveal that the integration of foreign metal elements and GB is responsible for the enhancement of activity and stability of RuO2 toward OER. A PEMWE using M-RuIrFeCoNiO2 catalyst can steadily operate at a large current density of 1 ampere per square centimeter for over 500 hours. This work demonstrates a pathway to design high-performance OER electrocatalysts by integrating the advantages of various components and GB, which breaks the limits of thermodynamic solubility for different metal elements.

Predictive analysis of catecholamines and electrolytes for recurrence of orthostatic intolerance in children.

Background: Orthostatic intolerance (OI) is usually mediated by the autonomic nerve and most often happens in the upright position. However, it can also occur in other positions and can be relieved by lying down while likely to have another attack after relief. In the current study, we aim to evaluate the predictive effect of catecholamines and electrolytes on the recurrence of OI in children. Materials and methods: Children who were diagnosed with vasovagal syncope (VVS), postural tachycardia syndrome (POTS), and VVS combined with POTS were enrolled in this retrospective study and were followed up after 1-year physical treatment. Catecholamines in urine collected within 24 h, renin, angiotensin II, aldosterone in plasma, and electrolytes in both blood and urine collected in the morning were tested. A multivariate analysis and a receiver operating characteristic curve were used to validate the prediction effect. Results: In the VVS cohort, the 24 h urine adrenaline (AD) and norepinephrine (NE) levels of the non-recurrence group were lower than the 24 h urine AD and NE levels of the recurrence group, with a significant difference of P < 0.05. A different content can also be witnessed in the POTS cohort that the urine of the non-recurrence group contained lower sodium and chlorine. As for the VVS + POTS cohort, the non-recurrence group has lower AD and NE levels and higher potassium and phosphorus levels in urine, the difference of which proved prominent as well. Conclusion: The study provides further evidence that AD, NE, and electrolytes in urine are promising factors that are closely related to the recurrence of OI in children. The integrated evaluation system merging AD and NE may have better predictive ability.

Analysis of the disease burden of cardiomyopathy in children aged 0-14 years in China from 1990 to 2019.

Objectives: To assess the disease burden and changing trend of cardiomyopathy in children aged 0-14 years in China from 1990 to 2019. Methods: This study was based on the Global Burden of Disease Study 2019; the age-specific prevalence rate, mortality rate and disability-adjusted life year (DALY) rate were used for analysis. Estimated annual percentage change (EAPC) in burden rate and its 95% confidence interval were calculated. The data of China were compared with the global average level. Results: In 2019, the numbers of prevalence, deaths, and DALYs of cardiomyopathy in children aged 0-14 years in China were 4,493 [95% uncertainty interval (UI): 2687 ~ 6,838], 434 (95%UI: 337 ~ 565) and 37,522 (95%UI: 29,321 ~ 48,891), with declining amplitudes of 16.32, 70.56, and 70.74%, compared with 1990, respectively. In 2019, the prevalence rate of cardiomyopathy in Chinese children aged 0-14 years was 2.00/100,000 (95%UI: 1.2/100,000 ~ 3.04/100,000), higher than 1990 [1.66/100,000 (95%UI:1.00/100,000 ~ 2.53/100,000)]; mortality rate was 0.19/100,000 (95%UI: 0.15/100,000 ~ 0.25/100,000), significantly lower than 1990 [0.46/100,000 (95%UI: 0.25/100,000 ~ 0.95/100,000)]; DALY rate was 16.69/100,000 (95%UI: 13.04/100,000 ~ 21.75/100,000), also significantly lower than 1990 [39.71/100,000 (95%UI: 22.06/100,000 ~ 82.8/100,000)]. All burden rates of cardiomyopathy in Chinese children aged 0-14 years old were all lower than the global averages of 2019; the burden rates of male children were higher than female children. In all calendar years from 1990 to 2019, the mortality and DALY rates of children younger than 1-year-old were significantly higher than in the other age groups of 0-14 years old. From 1990 to 2019, the prevalence rate of cardiomyopathy aged 0-14 years old gradually increased, with EAPC of 0.82 (95%CI: 0.71-0.93); mortality rate and DALY rate decreased [EAPC = -2.32 (95%CI: -2.59 to -2.05)]. Conclusion: From 1990 to 2019, the disease burden of cardiomyopathy in children of China aged 0-14 years was heterogeneous; the burden of male children was higher than females; and the burden of cardiomyopathy in children younger than 1 year old needs more attention.

Structurally-Distorted RuIr-Based Nanoframes for Long-Duration Oxygen Evolution Catalysis.

Oxygen evolution reaction (OER) plays a key role in proton exchange membrane water electrolysis (PEMWE), yet the electrocatalysts still suffer from the disadvantages of low activity and poor stability in acidic conditions. Here, a new class of CdRu2 IrOx nanoframes with distorted structure for acidic OER is successfully fabricated. Impressively, CdRu2 IrOx displays an ultralow overpotential of 189 mV and an ultralong stability of 1500 h at 10 mA cm⁻2 toward OER in 0.5 M H2 SO4 . Moreover, a PEMWE using the distorted CdRu2 IrOx can be steadily operated at 0.1 A cm⁻2 for 90 h. Microstructural analyses and X-ray absorption spectroscopy (XAS) demonstrate that the synergy between Ru and Ir in CdRu2 IrOx induces the distortion of Ru-O, Ir-O, and Ru-M (M = Ru, Ir) bonds. In situ XAS indicates that the applied potential leads to the deformation octahedral structure of RuOx /IrOx and the formation of stable Ru5+ species for OER. Theoretical calculations also reveal that the distorted structures can reduce the energy barrier of rate-limiting step during OER. This work provides an efficient strategy for constructing structural distortion to achieve significant enhancement on the activity and stability of OER catalysts.

Predictive value of monocyte to HDL-C ratio for coronary artery lesions and intravenous immunoglobulin resistance in Kawasaki disease.

We aimed to investigate the predictive validity of monocyte to high-density lipoprotein cholesterol ratio (MHR) for coronary artery lesions (CALs) and intravenous immunoglobulin (IVIG) resistance in complete Kawasaki disease (KD). MHR values of a total of 207 complete KD patients were calculated and analyzed with regard to their clinical characteristics and outcomes. We compared the differences in clinical data and laboratory parameters between CAL+ group and CAL- group as well as between IVIG-resistant group and IVIG-responsive group. Spearman's correlation analysis was applied to evaluate the correlation between C-reactive protein (CRP) and MHR. Multivariate logistic regression was used to identify risk factors of CALs and IVIG resistance. Receiver operating characteristic (ROC) curve analysis was chosen to determine the optimal cut-off value of MHR and its validity in predicting CALs and IVIG resistance. The MHR level was significantly higher in the CAL+ group, with cut-off value of 1.30 g/L, yielding a sensitivity of 0.753 and specificity of 0.805, as well as in IVIG-resistant group, with cut-off value of 1.03 g/L, yielding a sensitivity of 0.97 and specificity of 0.485. Multivariate logistic regression showed that MHR was an independent risk factor for CALs but not for IVIG resistance. According to the Spearman's correlation analysis, CRP was positively correlated with the MHR. CONCLUSIONS: As a practical, cost-effective inflammatory biomarker, MHR has a significantly predictive value in complete KD children complicated with CALs and IVIG-resistance. Paying more attention to the changes of MHR in KD children may contribute to better understanding of KD development and prognosis in clinical practice. WHAT IS KNOWN: • CALs are the most prevalent serious sequela of KD, and approximately 10%~20% of patients do not respond to IVIG therapy. • MHR could be a convenient biomarker to predict the development and progression of CVDs. It has been reported that the MHR is a new prognostic biomarker in several CVDs. WHAT IS NEW: • MHR has a significantly predictive value in KD children complicated with CALs and IVIG-resistance. • Compared with the molecular and immunological biomarkers that have been reported, MHR has the characteristics of practical, cost-effective, higher sensitivity and specificity, which can be used as a predictive indicator in complete KD patients.

A study on the perioperative effects of obesity on minimally invasive coronary artery bypass grafting and its surgical techniques.

OBJECTIVES: The aim of this study was to discuss the perioperative effects of obesity on minimally invasive coronary artery bypass grafting (CABG) and its surgical techniques. METHODS: A total of 582 patients with multivessel lesion who underwent off-pump CABG by our medical group of Beijing Anzhen Hospital between January 2017 and January 2021 were divided into the minimally invasive cardiac surgery (MICS) group and the conventional group (median sternotomy) according to the surgical method used. The body mass index of the patients was calculated, based on which both groups were divided into obese (≥28 kg/m2) and non-obese subgroups (<28 kg/m2). First, the perioperative data of the obese subgroups of both MICS and conventional groups were compared. Second, the obese and non-obese subgroups were compared in the MICS group. RESULTS: Despite a higher proportion of diabetes in the MICS group, there was no significant difference in preoperative baseline nor in the incidence of major complications within 30 days after surgery between obese subgroups of the MICS and conventional groups. The MICS group had a significantly lower rate of poor wound healing, along with a higher predischarge Barthel Index. Also, the preoperative baseline between the obese and non-obese subgroups of the MICS group exhibited no statistical differences. The obese subgroup had longer postoperative ventilator assistance, while other intraoperative data and postoperative observation indexes exhibited no significant differences. CONCLUSIONS: MICS CABG method is safe and feasible for obese patients with multivessel lesion. Minimally invasive surgery is beneficial to wound healing in obese patients. However, it requires a thorough preoperative evaluation and adequate surgical experience and skills.

Trace Lattice S Inserted RuO2 Flexible Nanosheets for Efficient and Long-Term Acidic Oxygen Evolution Catalysis.

Pursuing highly active and long-term stable ruthenium (Ru) based oxygen evolution reaction (OER) catalyst for water electrolysis under acidic conditions is of great significance yet a tremendous challenge to date. To solve the problem of serious Ru corrosion in an acid medium, the trace lattice sulfur (S) inserted RuO2 catalyst is prepared. The optimized catalyst (Ru/S NSs-400) has shown a record stability of 600 h for the solely containing Ru (iridium-free) nanomaterials. In the practical proton exchange membrane device, the Ru/S NSs-400 can even sustain more than 300 h without obvious decay at the high current density of 250 mA cm-2 . The detailed investigations reveal that S doping not only changes the electronic structure of Ru via forming RuS coordination for high adsorption of reaction intermediates but also stabilizes Ru from over-oxidation. This strategy is also effective for improving the stability of commercial Ru/C and homemade Ru-based nanoparticles. This work offers a highly effective strategy to design high-performance OER catalysts for water splitting and beyond.

Combination of Intracardiac Echocardiography and Contact Force Sensing for Left Ventricular Papillary Muscle Arrhythmias.

OBJECTIVES: The catheter ablation of ventricular arrhythmias (VAs) arising from the left ventricular (LV) papillary muscles (PMs) is challenging. This study sought to address whether the combination of intracardiac echocardiography (ICE) and contact force sensing (CFS) can improve the acute and long-term ablation outcomes of left ventricular papillary muscle arrhythmias. METHODS AND RESULTS: From May 2015 to August 2022, a total of thirty-three patients underwent catheter ablation for LV PM arrhythmias: VAs were located in anterolateral PMs in 11 and posteromedial PMs in 22. A combination of intracardiac echocardiography (ICE) and contact force sensing (CFS) was used in 21 of the 33 procedures. A mean of 6.93 ± 4.91 for lesions was used per patient, comparable between the CFS/ICE and no ICE/CFS (4.90 ± 2.23 vs. 10.17 ± 5.89; p = 0.011). The mean CF achieved in the ICE/CFS group was 7.52 ± 3.31 g. Less X-ray time was used in the combination group (CFS/ICE: 165.67 ± 47.80 S vs. no ICE/CFS: 365.00 ± 183.73 S; p < 0.001). An acute success rate of 100% was achieved for the ICE/CFS group (n = 22) and 66.67% for the no ICE/CFS group (n = 8). VA recurrence at the 11.21 ± 7.21-month follow-up was 14.2% for the ICE/CFS group and 50% for the no ICE/CFS group (p = 0.04). No severe complications occurred in all patients. CONCLUSIONS: The combination of intracardiac echocardiography (ICE) and contact force sensing (CFS) could provide precise geometries of cardiac endocavitary structures and accurate contact information for the catheter during ablation, which improved acute and long-term ablation outcomes. The routine adoption of this strategy should be considered to improve the outcomes of LV PM VA ablation.

Predictive value of EGSYS score in the differential diagnosis of cardiac syncope and neurally mediated syncope in children.

Background and objective: Syncope is a common emergency with diverse etiologies in children. Among these, cardiac syncope (CS) is associated with high mortality and is usually difficult to diagnose. However, there is still no validated clinical prediction model to distinguish CS from other forms of pediatric syncope. The Evaluation of Guidelines in Syncope Study (EGSYS) score was designed to identify CS in adults and has been validated in several studies. In this study, we aimed to assess the ability of the EGSYS score in predicting CS in children. Methods: In this retrospective study, we calculated and analyzed the EGSYS scores of 332 children hospitalized for syncope between January 2009 and December 2021. Among them, 281 were diagnosed with neurally mediated syncope (NMS) through the head-up tilt test, and 51 were diagnosed with CS using electrocardiography (ECG), echocardiography (ECHO), coronary computed tomography angiography (CTA), myocardial enzymes and genetic screening. The receiver operating characteristic (ROC) curve and Hosmer-Lemeshow test were used to evaluate the predictive value of the EGSYS score system. Results: The median scores of 51 children with CS and 281 children with NMS were 4 [interquartile range (IQR): 3-5] and -1 (IQR: -2-1), respectively. The area under the ROC curve (AUC) was 0.922 [95% confidence interval (CI): 0.892-0.952; P < 0.001], indicating that the EGSYS score system has good discrimination. The best cutoff point was ≥3, with a sensitivity and specificity of 84.3% and 87.9%, respectively. The Hosmer-Lemeshow test demonstrated satisfactory calibration (χ²=1.468, P > 0.05) of the score, indicating a good fit of the model. Conclusion: The EGSYS score appeared to be sensitive for differentiating CS from NMS in children. It might be used as an additional diagnostic tool to aid pediatricians in accurately identifying children with CS in the clinical practice.

Intramolecular and Intermolecular Interaction Switching in the Aggregates of Perylene Diimide Trimer: Effect of Hydrophobicity.

The research on perylene diimide (PDI) aggregates effectively promotes their applications in organic photovoltaic solar cells and fluorescent sensors. In this paper, a PDI fabricated with three peripheral PDI units (N, N'-bis(6-undecyl) perylene-3,4,9,10-bis(dicarboximide)) is investigated. The trimer shows different absorption and fluorescence properties due to hydrophobicity when dissolved in the mixed solvent of tetrahydrofuran (THF) and water. Through comprehensive analysis of the fluorescence lifetime and transient absorption spectroscopic results, we concluded that the trimer underwent different excited state kinetic pathways with different concentrations of water in THF. When dissolved in pure THF solvent, both the intramolecular charge-transfer and excimer states are formed. When the water concentration increases from 0 to 50% (v/v), the formation time of the excimer state and its structural relaxation time are prolonged, illustrating the arising of the intermolecular excimer state. It is interesting to determine that the probability of the intramolecular charge-transfer pathway will first decrease and then increase as the speed of intermolecular excimer formation slows down. The two inflection points appear when the water concentration is above 10% and 40%. The results not only highlight the importance of hydrophobicity on the aggregate properties of PDI multimers but also guide the further design of PDI-based organic photovoltaic solar cells.

Interface engineering of snow-like Ru/RuO2 nanosheets for boosting hydrogen electrocatalysis.

Ru has recently been regarded as a promising catalyst for hydrogen oxidation reaction (HOR) and hydrogen evolution reaction (HER) due to its similar binding energy towards *H but lower price compared to Pt. Nevertheless, the quest of high-efficiency Ru-based catalysts for HOR and HER is driven by the current disadvantages including low activity and unsatisfactory stability. Herein, we have fabricated and engineered two-dimensional (2D) Ru-based snow-like nanosheets with Ru/RuO2 interface (Ru/RuO2 SNSs) via a post-annealing treatment. Detailed characterizations and theoretical calculations indicate that the interfacial synergy, which is dependent on the temperature for annealing, can alter the hydrogen binding energy (HBE) and hydroxide binding energy (OHBE), as a result of the enhanced HOR and HER performance. Impressively, the optimal Ru/RuO2 SNSs display a mass activity of 9.13 A mgRu-1 at an overpotential of 50 mV in 0.1 mol L-1 KOH for HOR, which is 65, 304, and 21 times higher than those of Ru SNSs (0.14 A mgRu-1), RuO2 SNSs (0.03 A mgRu-1), and commercial Pt/C (0.43 A mgRu-1), respectively. Moreover, Ru/RuO2 SNSs display improved HER activity with a low overpotential of 20.2 mV for achieving 10 mA cm-2 in 1 mol L-1 KOH. This work not only provides an efficient catalyst for HOR and HER, but also promotes fundamental research on the fabrication and modification of catalysts in heterogeneous catalysis.

A One-Stone-Two-Birds Strategy to Functionalized Carbon Nanocages.

Carbon nanocages (CNCs) have attracted tremendous interest in heterogeneous catalysis due to their promising properties of porous structure and improved mass transfer. Nevertheless, the controlled synthesis of CNCs remains a great challenge. Herein, we have shown the successful construction of functionalized N-doped CNCs (NCNCs) via a one-stone-two-birds strategy. The selective use of hexacarbonyl molybdenum (Mo(CO)6) can not only protect the profile of the ZIF-8 precursor from collapse during thermal treatment but also be sacrificed for the functionalization of NCNCs after pyrolysis. Detailed mechanism studies reveal that Mo(CO)6 evolves into MoO3 on the surface of ZIF-8 and then facilitates the rapid pyrolysis of ZIF-8, leading to the formation of NCNCs decorated with small-sized MoC nanoparticles (MoC/NCNCs). The versatility of this one-stone-two-birds strategy has been validated by the generations of Cr- and W-decorated NCNCs. Moreover, MoC/NCNCs can serve as a selective and stable catalyst for furfural hydrogenation. This work provides a facile and universal strategy for fabricating and functionalizing CNCs, which attracts research interest in the fields of chemistry, material science, catalysis, and beyond.

Deciphering Photochemical Reaction Pathways of Aqueous Tetrachloroauric Acid by X-ray Transient Absorption Spectroscopy.

Photolysis reaction pathways of [Au(III)Cl4]- in aqueous solution have been investigated by time-resolved X-ray absorption spectroscopy. Ultraviolet excitation directly breaks the Au-Cl bond in [Au(III)Cl4]- to form [Au(II)Cl3]- that becomes highly reactive within 79 ps. Disproportionation of [Au(II)Cl3]- generates [Au(I)Cl2]-, which is stable for ≤10 µs. In contrast, intense near-infrared lasers photolyze water to generate hydrated electrons, which then reduce [Au(III)Cl4]- to [Au(II)Cl3]- at 5 ns. Hydrated electrons further induce a chain reaction from [Au(II)Cl3]- to [Au(0)Cl]- by successively removing one Cl-. The zero-valency Au anions quickly polymerize and condense to form Au nanoparticles, which become the dominating product after 400 s. Our results reveal that the condensation of zero-valency Au starts with dimerization of gold clusters coordinated with chloride ions rather than direct condensation of pristine Au atoms.

Vacancy-enhanced oxygen redox and structural stability of spinel Li2Mn3O7-x.

Vacancies have been proved effective in activating the oxygen redox and stabilizing the structure of the oxide cathode materials for the Na-ion batteries, but their effect on the cathode materials of the Li-ion batteries is unclear. We herein show that they have similar effect on spinel [Li4/7Mn2/7□1/7]8a[Li4/7Mn10/7]16d[O4-x']32e.