Memory-like NK Cells Are a Critical Component of Vaccine-Induced Immunity to Trypanosoma cruzi Infection.

Chagas disease by Trypanosoma cruzi infection is a major public health issue. The available therapeutic agents have limited efficacy and significant side effects. A reliable vaccine would reduce the threat of T. cruzi infections and prevent Chagas disease. Understanding the immune response to this infection would improve vaccine design. We previously demonstrated that adoptively transferred NK cells from mice immunized with highly attenuated T. cruzi, GFP-DDDHA strain, provided potent protection in naive recipients against secondary lethal challenge with various wild-type (WT) strains. To understand the importance of NK cells in protecting mice against T. cruzi infection, we performed an in-depth characterization of NK cell phenotype, responses, and memory-like traits during acute infections due to GFP-DDDHA and WT strains and in immunized mice during a recall response to a WT lethal challenge. NK cells robustly expanded and became more mature and cytolytic during the GFP-DDDHA strain immunization. NK cells in immunized mice responded more robustly after WT lethal challenge than during an acute primary WT infection. In addition, protection by immunization with the GFP-DDDHA strain is significantly weakened in NK cell-deficient mice and did not prevent parasitemia from WT lethal challenge, indicating that NK cells with memory-like traits were a critical component for early control of WT lethal challenge. Prior T. cruzi vaccine development studies have not included studies of this rapid NK response. These findings provide insights into overcoming existing challenges in developing a safe and effective vaccine to prevent this infection.

Photocatalytic Late-Stage C-H Functionalization.

The emergence of modern photocatalysis, characterized by mildness and selectivity, has significantly spurred innovative late-stage C-H functionalization approaches that make use of low energy photons as a controllable energy source. Compared to traditional late-stage functionalization strategies, photocatalysis paves the way toward complementary and/or previously unattainable regio- and chemoselectivities. Merging the compelling benefits of photocatalysis with the late-stage functionalization workflow offers a potentially unmatched arsenal to tackle drug development campaigns and beyond. This Review highlights the photocatalytic late-stage C-H functionalization strategies of small-molecule drugs, agrochemicals, and natural products, classified according to the targeted C-H bond and the newly formed one. Emphasis is devoted to identifying, describing, and comparing the main mechanistic scenarios. The Review draws a critical comparison between established ionic chemistry and photocatalyzed radical-based manifolds. The Review aims to establish the current state-of-the-art and illustrate the key unsolved challenges to be addressed in the future. The authors aim to introduce the general readership to the main approaches toward photocatalytic late-stage C-H functionalization, and specialist practitioners to the critical evaluation of the current methodologies, potential for improvement, and future uncharted directions.

Di-π-ethane Rearrangement of Cyano Groups via Energy-Transfer Catalysis.

Molecular rearrangement occupies a pivotal position among fundamental transformations in synthetic chemistry. Radical translocation has emerged as a prevalent synthetic tool, efficiently facilitating the migration of diverse functional groups. In contrast, the development of di-π-methane rearrangement remains limited, particularly in terms of the translocation of cyano functional groups. This is primarily attributed to the energetically unfavorable three-membered-ring transition state. Herein, we introduce an unprecedented di-π-ethane rearrangement enabled by energy-transfer catalysis under visible light conditions. This innovative open-shell rearrangement boasts broad tolerance toward a range of functional groups, encompassing even complex drug and natural product derivatives. Overall, the reported di-π-ethane rearrangement represents a complementary strategy to the development of radical translocation enabled by energy-transfer catalysis.

PatWRKY71 transcription factor regulates patchoulol biosynthesis and plant defense response.

Patchoulol, a valuable compound belonging to the sesquiterpenoid family, is the primary component of patchouli oil produced by Pogostemon cablin (P. cablin). It has a variety of pharmacological and biological activities and is widely used in the medical and cosmetic industries. However, despite its significance, there is a lack of research on the transcriptional modulation of patchoulol biosynthesis.Salicylic acid (SA), is a vital plant hormone that serves as a critical signal molecule and plays an essential role in plant growth and defense. However, to date, no studies have explored the modulation of patchoulol biosynthesis by SA. In our study, we discovered that the application of SA can enhance the production of patchoulol. Utilizing transcriptome analysis of SA-treated P. cablin, we identified a crucial downstream transcription factor, PatWRKY71. The transcription level of PatWRKY71 was significantly increased with the use of SA. Furthermore, our research has revealed that PatWRKY71 was capable of binding to the promoter of PatPTS, ultimately leading to an increase in its expression. When PatWRKY71 was silenced by a virus, the expression of both PatWRKY71 and PatPTS was reduced, resulting in the down-regulation of patchoulol production. Through our studies, we discovered that heterologous expression of PatWRKY71 leads to an increase in the sensitivity of Arabidopsis to salt and Cd, as well as an outbreak of reactive oxygen species (ROS). Additionally, we uncovered the regulatory role of PatWRKY71 in both patchoulol biosynthesis and plant defense response. This discovery provided a theoretical basis for the improvement of the content of patchoulol and the resistance of P. cablin through genetic engineering.

Tuning Hole Transport Properties and Perovskite Crystallization via Pyridine-Based Molecules for Quasi-2D Perovskite Solar Cells.

Quasi-2D perovskites show great potential as photovoltaic devices with superior stability, but the power conversion efficiency (PCE) is limited by poor carrier transport. Here, it is simultaneously affected the hole transport layer (HTL) and the perovskite layer by incorporating pyridine-based materials into poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT:PSS) to address the key problem above in 2D perovskites. With this approach, the enhanced optoelectronic performance of the novel PEDOT:PSS is due to electron transfer between the additives and PEDOT or PSS, as well as a dissociation between PEDOT and PSS based on experimental and theoretical studies, which facilitates the charge extraction and transfer. Concurrently, in-situ X-ray scattering studies reveal that the introduction of pyridine-based molecules alters the transformation process of the perovskite intermediate phase, which leads to a preferred orientation and ordered distribution caused by the Pb─N chemical bridge, achieving efficient charge transport. As a result, the pyridine-treated devices achieve an increased short-circuit current density (Jsc) and PCE of over 17%.

Molecular Regulation of Shoot Architecture in Soybean.

Soybean (Glycine max [L.] Merr.) serves as a major source of protein and oil for humans and animals. Shoot architecture, the spatial arrangement of a plant's above-ground organs, strongly affects crop yield and is therefore a critical agronomic trait. Unlike wheat and rice crops that have greatly benefitted from the Green Revolution, soybean yield has not changed significantly in the past six decades owing to its unique shoot architecture. Soybean is a pod-bearing crop with pods adhered to the nodes, and variation in shoot architecture traits, such as plant height, node number, branch number and number of seeds per pod, directly affects the number of pods and seeds per plant, thereby determining yield. In this review, we summarize the relationship between soybean yield and these major components of shoot architecture. We also describe the latest advances in identifying the genes and molecular mechanisms underlying soybean shoot architecture and discuss possible directions and approaches for breeding new soybean varieties with ideal shoot architecture and improved yield.

Optical TTD compensation network-based phase precoding for THz massive MIMO systems.

In sixth generation (6G) communications, terahertz (THz) communication is one of the most important technologies in the future due to its ultra-bandwidth, where hybrid beamforming has been widely used to solve the severe transmission attenuation in the THz band. However, the use of frequency-flat phase shifters in hybrid beamforming leads to the beam split effect. To solve the beam split influence, we propose a novel optical true time delay compensation network (OTTDCN)-based phase precoding structure with low power consumption. In the proposed scheme, the OTTDCN pre-generates multiple beam compensation modes to achieve phase compensation for different frequencies. As a result, the compensated beams can be reoriented toward the target direction at different frequencies. Moreover, a low-complexity beam compensation mode-based hybrid precoding algorithm is proposed, where the selection of the optimal beam compensation modes used for all radio-frequency (RF) chains with finite beam compensation modes is considered. The results show that the OTTDCN-based phase precoding scheme can effectively alleviate the beam split effect with low power consumption and achieve near-optimal performance.

Neutrophil extracellular traps (NETs) and Th-2 dominant immune responses in chronic granulomatous chromobalstomycosis.

Chromoblastomycosis (CBM), a chronic, granulomatous, suppurative mycosis of the skin and subcutaneous tissue, is caused by several dematiaceous fungi. The formation of granulomas, tissue proliferation, and fibrosis in response to these pathogenic fungi is believed to be intricately linked to host immunity. To understand this complex interaction, we conducted a comprehensive analysis of immune cell infiltrates, neutrophil extracellular traps (NETs) formation, and the fibrosis mechanism in 20 CBM lesion biopsies using immunohistochemical and immunofluorescence staining methods. The results revealed a significant infiltration of mixed inflammatory cells in CBM granulomas, prominently featuring a substantial presence of Th2 cells and M2 macrophages. These cells appeared to contribute to the production of collagen I and III in the late fibrosis mechanism, as well as NETs formation. The abundance of Th2 cytokines may act as a factor promoting the bias of macrophage differentiation toward M2, which hinders efficient fungal clearance while accelerates the proliferation of fibrous tissue. Furthermore, the expression of IL-17 was noted to recruit neutrophils, facilitating subsequent NETs formation within CBM granulomas to impede the spread of sclerotic cells. Understanding of these immune mechanisms holds promise for identifying therapeutic targets for managing chronic granulomatous CBM.

Pooling sputum samples for the Xpert MTB/RIF assay: a practical screening strategy for highly infectious tuberculosis cases.

The Xpert MTB/RIF test (Xpert) can help in the accurate screening of tuberculosis, however, its widespread use is limited by its high cost and lack of accessibility. Pooling of sputum samples for testing is a strategy to cut expenses and enhance population coverage but may result in a decrease in detection sensitivity due to the dilution of Mycobacterium tuberculosis (Mtb) by sample mixing. We investigated how the mixing ratio affected the detection performance of Xpert. We used frozen sputum samples that had been kept after individual Xpert assays of the sputa from Mtb-confirmed TB patients and non-TB patients. Our results showed that the overall sensitivity of the Xpert pooling assay remained higher than 80% when the mixing ratio was between 1/2 and 1/8. When the mixing ratio was raised to 1/16, the positive detection rate fell to 69.0%. For patients with either a high sputum Mtb smear score ≥ 2+, a time-to-positive culture ≤ 10 days, or an Xpert test indicating a high or medium abundance of bacteria, the pooling assay positivity rates were 93.3%, 96.8%, and 100% respectively, even at a 1/16 mixing ratio. For participants with cavities and cough, the pooling assay positivity rates were 86.2% and 90.0% at a 1/8 ratio, higher than for those without these signs. Our results show that the Xpert pooled assay has a high overall sensitivity, especially for highly infectious patients. This pooling strategy with lower reagent and labor costs could support TB screening in communities with limited resources, thereby facilitating reductions in the community transmission and incidence of TB worldwide.

Effect of apheresis plasma donation on plasma uric acid levels, the lipid profile, and major plasma proteins in plasma donors in China: A multicenter, prospective cohort study.

Abnormal plasma uric acid (UA) levels, the lipid profile, and plasma proteins in blood are associated with a range of adverse health outcomes. This multicenter, prospective cohort study aimed to determine the possible effects of multiple apheresis plasma donations on plasma UA levels, the lipid profile, and major proteins in plasma donors. Participants were enrolled from 1 April 2021 to 31 August 2022. When their plasma UA (men: >420 µmol/L, women: >360 µmol/L) and/or lipid levels (total cholesterol [TC]: ≥6.2 mmol/L, triglycerides [TGs]: ≥2.3 mmol/L, low-density lipoprotein cholesterol: ≥4.1 mmol/L, or high-density lipoprotein cholesterol [HDL-C]: <1.0 mmol/L) were abnormal at their first plasma donation, the enrolled participants were followed up until they had completed 10 plasma donations. A total of 11485 participants were enrolled, of whom 1861 met the inclusion criteria. During the study period, 320 donors completed 10 plasma donations. None of the participants took any corrective medicine for their abnormal index. The measured parameters were significantly different from the first to the tenth plasma donations (donors with asymptomatic hyperuricemia: UA, P < 0.001; donors with asymptomatic hyperlipidemia: HDL-C, P < 0.001; TC, P = 0.025; TGs, P < 0.001; apolipoprotein B, P = 0.025; all of the plasma donors, immunoglobulin G, P < 0.001). The levels of HDL-C, TC, and apolipoprotein B were increased, and the levels of UA, TGs, and immunoglobulin G were decreased over this time. However, immunoglobulin G levels were still in the normal range. Moreover, the changes in these parameters were closely associated with the frequency of plasma donation during the study period. Repeated apheresis plasma donations can reduce plasma UA and TG levels and increase HDL-C levels; and further evaluation of the clinical significance with a larger sample size is required.

The body mass index and the risk of ectopic pregnancy: a 5-year retrospective case-control study.

PURPOSE: Acknowledging the associated risk factors may have a positive impact on reducing the incidence of ectopic pregnancy (EP). In recent years, body mass index (BMI) has been mentioned in research. However, few studies are available and controversial on the relationship between EP and BMI. METHODS: We retrospectively studied the EP women as a case group and the deliveries as a control group in the central hospital of Wuhan during 2017 ~ 2021. χ2 test of variables associated with ectopic pregnancy was performed to find differences. Univariate and multivariate binary logistic regression analysis was conducted to analyze the association of the variables of age, parity, history of induced abortion, history of ectopic pregnancy, history of spontaneous abortion, history of appendectomy surgery and BMI (< 18.5 kg/m2, 18.5 ~ 24.9 kg/m2, 25 kg/m2 ~ 29.9 kg/m2, ≥ 30 kg /m2) with EP. RESULTS: They were 659 EP and 1460 deliveries. The variables of age, parity, history of induced abortion, history of ectopic pregnancy and BMI were different significantly(P < 0.05). Multivariate analysis showed that the variables of age > 35 years old [(OR (Odds Ratio), 5.415; 95%CI (Confidence Interval), 4.006 ~ 7.320, P < 0.001], history of ectopic pregnancy (OR, 3.944; 95%CI, 2.405 ~ 6.467; P < 0.001), history of induced abortion(OR, 3.365; 95%CI, 2.724 ~ 4.158, P < 0.001) and low BMI (< 18.5 kg/m2) (OR, 1.929; 95%CI, 1.416 ~ 2.628, P < 0.001])increased the risk of EP. CONCLUSION: The history of ectopic pregnancy, history of induced abortion and age > 35 years old were the risk factors with EP. In addition to these traditional factors, we found low BMI (< 18.5 kg/m2) with women may increase the risk to EP.

The effect of health education on symptom severity in patients with fibromyalgia: a systematic review and meta-analysis.

Fibromyalgia (FM) is a complex chronic disorder characterized by widespread pain as the primary symptom. To evaluate the effect of health education on the severity of various symptoms in patients with FM, seven databases were searched from inception to August 2024 to identify randomized controlled trials evaluating the effects of health education for FM. The primary outcome was overall symptom severity, and the secondary outcomes were pain, depression, anxiety, sleep quality, fatigue, physical function and self-efficacy. The Cochrane Risk-of-Bias tool for randomized trials and the Grading of Recommendations, Assessment, Development, and Evaluations were used to assess the quality of the included studies and the certainty of evidence, respectively. Treatment effects were estimated by calculating Hedges' g and the corresponding 95% confidence intervals. Meta-analysis included a total of 13 trials. The results revealed that health education significantly reduced overall symptom severity, depression and anxiety and increased sleep quality and physical function among patients with FM (all P values < 0.05). However, no significant effects were observed on pain, fatigue and self-efficacy. Health education may be a beneficial intervention for FM patients, particularly for mitigating symptom severity. Health-care providers should implement health education interventions to empower patients to effectively manage their symptoms.

The gut microbiota composition and metabolites are different in women with hypertensive disorders of pregnancy and normotension: A pilot study.

INTRODUCTION: Hypertensive disorders of pregnancy (HDP) are one of the main causes of perinatal morbidity. Gut microbiota influences host inflammatory pathways, glucose, and lipid metabolism. However, there is a lack of studies available on gut microbiota in HDP. OBJECTIVES: We investigate the mechanistic and pathogenic role of microbiota in the development of HDP, and want to treat HDP with gut microbiota. METHODS: We performed a case-control study to compare fecal samples of HDP and normotensive pregnant women by 16S ribosomal RNA sequencing. Fecal samples, collected from pregnant women, were divided into groups P and C (pregnant women with HDP and normotension, respectively). There were six pregnant women in group P and nine pregnant women in group C. Age of pregnant women is from 18 to 40 years and gestational age is from 27 to 40 weeks. DNA was extracted from fecal samples; a gene library was constructed and analyzed using bioinformatics. Finally, we determined the changes in the microbiome by alpha diversity, beta diversity, classification abundance, and taxonomic composition analyses. RESULTS: Escherichia (10.48% in group P and 0.61% in group C) was the dominant bacterium in HDP patients by classification abundance analysis, which can lead to the development of preeclampsia through inflammatory response. We found that pregnant women with HDP had higher abundance of Rothia (p = 0.04984), Actinomyces (p = 0.02040), and Enterococcus (p = 0.04974) and lower abundance of Coprococcus (p = 0.04955) than pregnant women with normotension for the first time by taxonomic composition analysis. Based on the Kyoto Encyclopedia of Genes and Genomes database analysis, physiological and biochemical functions of HDP patients were significantly weakened, especially in energy metabolism. CONCLUSIONS: We found the effect of changes in gut microbiota on the development of HDP. In comparison with group C, group P contained more harmful bacteria and less beneficial bacteria, which are associated with HDP. Our research further provides a basis for a clinical application for HDP treatment using antibiotics and probiotic supplementation.

Urinary Microalbumin predicts early neurological deterioration in acute ischemic stroke: A study based on etiological classification.

INTRODUCTION: To investigate the correlation between urinary microalbumin (U-Alb) levels and early neurological deterioration (END), as well as its predictive ability, in patients with acute ischemic stroke (AIS) under different etiological subtypes. MATERIALS AND METHODS: We consecutively enrolled AIS patients within 72 h of onset, collecting relevant clinical characteristics and baseline laboratory data including U-Alb. END was defined as an increase of ≥4 points in NIHSS score within 72 h of onset, and TOAST criteria were used for stroke etiologic typing. Binary logistic regression analysis was employed to clarify the association between baseline U-Alb and the occurrence of END under different stroke etiological subtypes. ROC analysis was conducted to evaluate its predictive ability under different etiological subtypes. RESULTS: Finally, 615 patients were included, with 104 (16.9 %) developed END. Binary logistic regression analysis revealed that baseline U-Alb was independently associated with END occurrence (OR = 1.009, 95 % CI 1.002-1.016, p = 0.009). ROC analysis revealed that U-Alb had the best predictive ability for patients with small artery occlusion (AUC=0.707, p < 0.001), followed by large artery atherosclerosis (AUC = 0.632, p = 0.006), with corresponding optimal diagnostic cutoff points of 31.11 and 25.71 mg/L, respectively. However, U-Alb was not an independent risk factor for END in cardioembolic stroke patients (OR = 1.011, 95 % CI 0.980-1.043, p = 0.478). MAU was associated with stroke progression(p = 0.023), and U-Alb was positively correlated with increased infarct volume (r = 0.516, p < 0.01). CONCLUSION: U-Alb is closely associated with END in AIS patients, serving as a potential indicator for predicting END, especially among those with small artery occlusion mechanisms.

Runoff nitrogen losses under confluence and diverging drainage systems in the sloped plot scale: A comparative study.

The drainage system is a key measure for regulating runoff nutrient losses on sloping farmlands. Confluence and diverging drainage systems are two drainage layouts representing natural water network systems and are widely distributed in sloping farmlands; however, the effects of these drainage systems on runoff nutrient losses in the sloped plots remain unclear. This study investigated the effects of different drainage systems on the characteristics of runoff nitrogen (N) losses in sloped plots using laboratory rainfall simulations. Three treatments, including bare slope (without drainage system, CK), confluence drainage system (T1), and diverging drainage system (T2), were used to compare the changes in concentrations and losses of total nitrogen (TN), dissolved nitrogen (DN), and particulate nitrogen (PN), and the DN:TN ratio in runoff under a combination of 1.8 mm min-1 rainfall intensity and three slope gradients (5°, 10°, and 15°). The results showed that the time to runoff was significantly delayed in T2 compared with that in CK and T1 across all slopes (p < 0.05). Accumulated runoff depth was considerably lower in T1 and T2 than in CK across all slopes (p < 0.05). The TN and PN concentrations in T1 were markedly lower than those in T2 on the 10° and 15° slopes (p < 0.05). The DN concentration in T1 was lowest at the 5° slope (p < 0.05). TN loss in T1 was 14.7-33.9% and 17.9-30.3% lower than those in CK and T2 across all slopes, respectively (p < 0.05). The PN loss in T1 was 56.7% and 53.3% lower than that in T2 on the 10° and 15° slopes, respectively (p < 0.05). DN loss in T1 was 39.3-72.5% lower than that in CK for all slopes (p < 0.05). DN:TN in T2 was lower than that in CK and T1 at the 10° and 15° slopes (p < 0.05). Our results confirm the effectiveness of drainage systems in reducing runoff nutrient losses in a sloped plot and demonstrate that the confluence drainage system is better at reducing N losses in runoff than diverging drainage systems.

Spatial-temporal pattern of ecosystem services and sustainable development in representative mountainous cities: A case study of Chengdu-Chongqing Urban Agglomeration.

The Sustainable Development Goals (SDGs) are essential measure for preserving the balance between human well-being and natural ecosystems. The benefit of preserving ecosystems health play a crucial role in promoting the SDGs by providing stable ecosystem services (ESs). However, the ecological health of mountainous cities is vulnerable, with relative low ecological resilience. To investigate the conflict between ecosystems and sustainable development, this study takes the Chengdu-Chongqing Urban Agglomeration as the study area. The major tasks and results in this study include: (1) using the entropy weighting method and the InVEST model, we combined remote sensing, geographic, and statistical data to quantify three types of SDGs (economic, social, environmental) and four ESs (water yield, soil conservation, habitat quality, carbon storage), and establish a localized sustainable development assessment framework that is applicable to the Chengdu-Chongqing Urban Agglomeration. The results show that from 2014 to 2020, the three types of SDGs exhibited an overall upward trend, with the lowest values occurring in 2016. The gap between different counties has narrowed, but significant regional differences still remain, indicating an unbalanced development status quo. Among the 142 counties, water yield and soil conservation values show a consistent downward trend but occupies significant interannual variations, while habitat quality and carbon storage values increases consistently each year. (2) using Spearman's nonparametric correlation analysis and multiscale geographically weighted regression model to explore the temporal variation and spatial heterogeneity of correlations between county ESs and SDGs. The results showed significant heterogeneity in the spatial trade-offs and synergies between ESs and SDGs, with two pairs of synergies weakening, seven pairs of trade-offs increasing, and the strongest negative correlation between Economic Sustainable Development Goals and habitat quality. (3) we applied the self-organizing mapping neural networks to analyze the spatial clustering characteristics of ESs-SDGs. Based on the spatial clustering effects, we divides the Chengdu-Chongqing Urban Agglomeration into four zones, and different zones have different levels of ESs and SDGs. The targeted strategies should be adopted according to local conditions. This work is of great practical importance in maintaining the stability and sustainable development of the Chengdu-Chongqing Urban Agglomeration ecosystem and provides a scientific reference for the optimal regulation of mountainous cities.

Cyclic Amine Synthesis via Catalytic Radical-Polar Crossover Cycloadditions.

The rapid assembly of valuable cyclic amine architectures in a single step from simple precursors has been recognized as an ideal platform in term of efficiency and sustainability. Although a vast number of studies regarding cyclic amine synthesis has been reported, new synthetic disconnection approaches are still high in demand. Herein, we report a catalytic radical-polar crossover cycloaddition to cyclic amine synthesis triggered from primary sulfonamide under photoredox condition. This newly developed disconnection, comparable to established synthetic approaches, will allow to construct ß, ß-disubstituted cyclic amine and ß-monosubstituted cyclic amine derivatives efficiently. This study highlights the unique utility of primary sulfonamide as a bifunctional reagent, which acts as a radical precursor and a nucleophile. The open-shell methodology demonstrates broad tolerance to various functional groups, drug derivatives and natural products in an economically and sustainable fashion.

Unveiling Low Temperature Assembly of Dense Fe-N4 Active Sites via Hydrogenation in Advanced Oxygen Reduction Catalysts.

The single-atom Fe-N-C is a prominent material with exceptional reactivity in areas of sustainable energy and catalysis research. It is challenging to obtain the dense Fe-N4 site without the Fe nanoparticles (NPs) sintering during the Fe-N-C synthesis via high-temperature pyrolysis. Thus, a novel approach is devised for the Fe-N-C synthesis at low temperatures. Taking FeCl2 as Fe source, a hydrogen environment can facilitate oxygen removal and dichlorination processes in the synthesis, efficiently favouring Fe-N4 site formation without Fe NPs clustering at as low as 360 °C. We shed light on the reaction mechanism about hydrogen promoting Fe-N4 formation in the synthesis. By adjusting the temperature and duration, the Fe-N4 structural evolution and site density can be precisely tuned to directly influence the catalytic behaviour of the Fe-N-C material. The FeNC-H2-360 catalyst demonstrates a remarkable Fe dispersion (8.3 wt %) and superior acid ORR activity with a half-wave potential of 0.85 V and a peak power density of 1.21 W cm-2 in fuel cell. This method also generally facilitates the synthesis of various high-performance M-N-C materials (M=Fe, Co, Mn, Ni, Zn, Ru) with elevated single-atom loadings.

Selective Activation of Lattice Oxygen Site Through Coordination Engineering to Boost the Activity and Stability of Oxygen Evolution Reaction.

Although Ru-based materials are among the outstanding catalysts for the oxygen evolution reaction (OER), the instability issue still haunts them and impedes the widespread application. The instability of Ru-based OER catalysts is generally ascribed to the formation of soluble species through the over-oxidation of Ru and structural decomposition caused by involvement of lattice oxygen. Herein, an effective strategy of selectively activating the lattice oxygen around Ru site is proposed to improve the OER activity and stability. Our synthesized spinel-type electrocatalyst of Ru and Zn co-doped Co3O4 showed an ultralow overpotential of 172 mV at 10 mA cm-2 and a long-term stability reaching to 100 hours at 10 mA cm-2 for alkaline OER. The experimental results and theoretical simulations demonstrated that the lattice oxygen site jointly connected with the octahedral Ru and tetrahedral Zn atoms became more active than other oxygen sites near Ru atom, which further lowered the reaction energy barriers and avoided generating excessive oxygen vacancies to enhance the structural stability of Ru sites. The findings hope to provide a new perspective to improve the catalytic activity of Ru-incorporated OER catalysts and the stability of lattice-oxygen-mediated mechanism.

Implanting Transition Metal into Li2 O-Based Cathode Prelithiation Agent for High-Energy-Density and Long-Life Li-Ion Batteries.

Compensating the irreversible loss of limited active lithium (Li) is essentially important for improving the energy-density and cycle-life of practical Li-ion battery full-cell, especially after employing high-capacity but low initial coulombic efficiency anode candidates. Introducing prelithiation agent can provide additional Li source for such compensation. Herein, we precisely implant trace Co (extracted from transition metal oxide) into the Li site of Li2 O, obtaining (Li0.66 Co0.11 □0.23 )2 O (CLO) cathode prelithiation agent. The synergistic formation of Li vacancies and Co-derived catalysis efficiently enhance the inherent conductivity and weaken the Li-O interaction of Li2 O, which facilitates its anionic oxidation to peroxo/superoxo species and gaseous O2 , achieving 1642.7 mAh/g~Li2O prelithiation capacity (≈980 mAh/g for prelithiation agent). Coupled 6.5 wt % CLO-based prelithiation agent with LiCoO2 cathode, substantial additional Li source stored within CLO is efficiently released to compensate the Li consumption on the SiO/C anode, achieving 270 Wh/kg pouch-type full-cell with 92 % capacity retention after 1000 cycles.