Role of the Metal Precursor in Preparing Dual-Atom Catalysts for the Oxygen Reduction Reaction.

Dual-atom catalysts (DACs) have arisen as a novel type of heterogeneous catalyst that extends from single-atom catalysts (SACs) by incorporating two kinds of metals. These materials have demonstrated enhanced performance when compared to SACs. The choice of metal precursors plays an important role in the synthesis of DACs. Here, we choose Fe and Co as DAC models and study types, contents, molar ratios of two precursors, and oxygen reduction reaction (ORR) activity. The Fe,Co DACs were synthesized by an adsorption-annealing approach, using nitrogen-doped graphitic carbon (NC) as the support. As a result, the adsorption ability of metal precursors on the support determines the metal loadings in Fe and Co DACs, leading to differences in ORR performance. The Fe precursors win the adsorption competitions in most cases, resulting in a much higher loading than that of Co precursors. Importantly, it is difficult to increase the precursor content by simply increasing the initial amount. Choosing the right combination of metal precursors, such as ferrocene and cobalt chloride, can yield Fe,Co DACs with enhanced ORR performance..

Steering the liquid-solid redox conversion of lithium-selenium batteries through ultrafine MoC catalyst.

Selenium cathodes have attracted much attention because of the high electronic conductivity and energy density. However, the shuttle effect of lithium polyselenides (LiPSes) leads to rapid capacity fading, hindering the practical application of lithium-selenium (Li-Se) batteries. Herein, an ultrafine MoC catalyst has been synthesized and utilized to accelerate the conversion from liquid LiPSes to solid Li2Se2/Li2Se, leading to suppressed shuttle effect and thus improved battery performance. Our present study provides valuable inspiration to the future exploration for the rational design of high-efficient catalysts for practical Li-Se batteries.

Local Construction of Mn-Based Layered Cathodes through Covalency Modulation for Sodium-Ion Batteries.

P2-type Mn-based layered oxides are among the most prevalent cathodes for sodium-ion batteries (SIBs) owing to their low cost, resource abundance, and high theoretical specific capacity. However, they usually suffer from Jahn-Teller (J-T) distortion from high-spin Mn3+ and poor cycling stability, resulting in rapid degradation of their structural and electrochemical properties. Herein, a stable P2-type Mn-based layered oxide is realized through a local construction strategy by introducing high-valence Ru4+ to overcome these issues. It has been revealed that the Ru substitution in the as-constructed Na0.6Mg0.3Mn0.6Ru0.1O2 (NMMRO) renders the following favorable effects. First, the detrimental P2-OP4 phase transition is effectively inhibited owing to the robust Ru-O covalency bond. Second, the Mg/Mn ordering is disturbed and the out-of-plane displacement of Mg2+ and in-plane migration of Mn4+ are suppressed, leading to improved structural stability. Third, the redox ability of Mn is increased by weakening the covalence between Mn and O through the local Ru-O-Mn configurations, which contributes to the attenuated J-T distortion. Last, the strong Ru-O covalency bond also leads to enhanced electron delocalization between Ru and O, which decreases the oxidation of oxygen anion and thereby reduces the driving force of metal migration. Because of these advantages, the structural integrity and electrochemical properties of NMMRO are largely improved compared with the Ru-free counterpart. This work provides deeper insights into the effect of local modulation for cationic/anionic redox-active cathodes for high-performance SIBs.

Risk factors for venous thromboembolism in patients with spinal cord injury: A systematic review and meta-analysis.

CONTEXT: Patients with spinal cord injury (SCI) are at high risk for venous thromboembolism (VTE). The risk factors for VTE in patients with SCI are complex. OBJECTIVE: This meta-analysis was conducted to clarify the risk factors for VTE in patients with SCI. METHODS: The Cochrane Library, PubMed, EBSCO, Web of Science, China National Knowledge Infrastructure (CNKI), China Biomedical Literature Database (CBM), Wanfang Med Data Database, and VIP Database were searched to identify studies reporting on risk factors for VTE in patients with SCI. RESULTS: The meta-analysis included 25 studies. Findings showed that risk of VTE in patients with SCI was significantly associated with middle- and old-age (OR = 2.08, 95%CI, 1.47, 2.95), male sex (OR = 1.41, 95%CI, 1.26, 1.59), complete paralysis (OR = 3.69, 95%CI, 2.60, 5.24), personal/family history of venous thrombosis (OR = 1.95, 95%CI, 1.35, 2.81), history of smoking (OR = 2.67, 95%CI, 1.79, 3.98), lack of compression therapy (OR = 2.44, 95%CI, 1.59, 3.73), presence of lower limb/pelvic fracture (OR = 3.47, 95%CI, 1.79, 6.75), paraplegia (OR = 1.81, 95%CI, 1.49, 2.19), and diabetes (OR = 4.24, 95%CI, 2.75, 6.52). CONCLUSION: The meta-analysis identified 9 risk factors for VTE in patients with SCI. Healthcare providers should be aware of the risk factors for VTE when rehabilitating patients with SCI.

Light-Triggered Sustainable Defect-Passivation for Stable Perovskite Photovoltaics.

The generation of photoinduced defects and freely moving halogen ions is dynamically updated in real time. Accordingly, most reported strategies are static and short-term, which make their improvements in photostability very limited. Therefore, seeking new passivation strategies to match the dynamic characteristics of defect generation is very urgent. Without newly generated defects, a passivation molecule should exist in the configuration that would not become the initiation sites for defect generation. With newly generated defects, the passivation molecule should transfer into the other configuration that possesses the passivation sites. Herein, a classical photoisomeric molecule, spiropyran, is adopted, whose pre- and post-isomeric forms meet the requirements for two different configurations, to realize the state transition once the photoinduced defects appear during subsequent operation and dynamic capture for continuous renewal of defects. Consequently, spiropyrans work as light-triggered and self-healing sustainable passivation sites to realize continuous defect repair. The target devices retain 93% and 99% of their initial power conversion efficiencies after 456 h aging under ultraviolet illumination and 1200 h aging under full-spectrum illumination, respectively. This work provides a novel concept of sustainable passivation strategy to realize continuous defect-passivation and film-healing in perovskite photovoltaics.

Strengthened d-p Orbital Hybridization through Asymmetric Coordination Engineering of Single-Atom Catalysts for Durable Lithium-Sulfur Batteries.

Although single-atom catalysts (SACs) have been largely explored in lithium-sulfur (Li-S) batteries, the commonly reported nonpolar transition metal-N4 coordinations only demonstrate inferior adsorption and catalytic activity toward shuttled lithium polysulfides (LiPSs). Herein, single Fe atoms with asymmetric coordination configurations of Fe-N3C2-C were precisely designed and synthesized as efficient immobilizer and catalyst for LiPSs. The experimental and theoretical results elucidate that the asymmetrically coordinated Fe-N3C2-C moieties not only enhance the LiPSs anchoring capability by the formation of extra π-bonds originating from S p orbital and Fe dx2-y2/dxy orbital hybridization but also boost the redox kinetics of LiPSs with reduced Li2S precipitation/decomposition barrier, leading to suppressed shuttle effect. Consequently, the Li-S batteries assembled with Fe-N3C2-C exhibit high areal capacity and cycling stability even under high sulfur loading and lean electrolyte conditions. This work highlights the important role of coordination symmetry of SACs for promoting the practical application of Li-S batteries.

Identification of CXCL10 as a Prognostic Biomarker for Clear Cell Renal Cell Carcinoma.

Background: One of the widespread forms of kidney tumor is clear cell renal cell carcinoma (ccRCC), with poor prognosis and insensitivity to radio chemotherapy as there is limited capacity to understand the disease mechanism. This study aims at identifying potential biomarkers and the underlying processes of ccRCC using bioinformatics analysis. Methods: Transcriptome data of relevant samples were downloaded from The Cancer Genome Atlas (TCGA) database. R software was used to screen differentially expressed genes (DEGs) using the "edgeR" package. Two types of analysis-Gene Ontology (GO) functional and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment-were accomplished by applying Database for Annotation, Visualization, and Integrated Discovery (DAVID) and Search Tool for the Retrieval of Interacting Genes database (STRING) online bioinformatics tools. A protein-protein interaction (PPI) network of the identified DEGs was constructed using Cytoscape software, and hub genes were subsequently selected via the Cytohubba plug-in. The selected genes were input into Oncomine for verification. Finally, selected hub genes were analyzed by doing survival analysis to notice the relationship between survival (OS) rate and the selected genes' level of expression. Results: There were 1,855 DEGs found connected to ccRCC, with 1,207 upregulated genes and 648 downregulated genes. G-protein-coupled receptor signaling pathway, integral component of membrane, calcium ion binding, and cytokine-cytokine receptor interaction were among the DEGs discovered. Oncomine confirmed the top six hub genes from the PPI network (C3, CXCR3, CXCL10, CCR5, CCL4, and CCL5). A high level of expression of CXCL10, one of these hub genes, was linked to a poor prognosis in individuals with ccRCC. The results of survival analysis showed that the expression level of CXCL10 was significantly correlated with the prognosis of ccRCC patients (p < 0.05). Conclusions: From the analysis, the following results were drawn: CXCL10 might be a potential prognostic biomarker and novel therapeutic target for ccRCC.

Full-Dimensional Grain Boundary Stress Release for Flexible Perovskite Indoor Photovoltaics.

Perovskite photovoltaics are strong potential candidates to drive low-power off-grid electronics for indoor applications. Compared with rigid devices, flexible perovskite devices can provide a more suitable surface for indoor small electronic devices, enabling them have a broader indoor application prospect. However, the mechanical stability of flexible perovskite photovoltaics is an urgent issue solved. Herein, a kind of 3D crosslinking agent named borax is selected to carry out grain boundary penetration treatment on perovskite film to realize full-dimensional stress release. This strategy improves the mechanical and phase stabilities of perovskite films subjected to external forces or large temperature changes. The fabricated perovskite photovoltaics deliver a champion power conversion efficiency (PCE) of 21.63% under AM 1.5G illumination, which is the highest one to date. The merit of low trap states under weak light makes the devices present a superior indoor PCE of 31.85% under 1062 lux (LED, 2956 K), which is currently the best flexible perovskite indoor photovoltaic device. This work provides a full-dimensional grain boundary stress release strategy for highly stable flexible perovskite indoor photovoltaics.

Pediatric spinal cord injury rehabilitation: A protocol for an international multicenter project (SINpedSCI).

PURPOSE: Children and adolescents (<18 years old) who sustain a spinal cord injury (SCI) should ideally be managed in specialized rehabilitation services. This project aims to describe the organization of pediatric SCI in ten rehabilitation units in seven countries and to qualitatively explore psychosocial aspects of adolescents living with SCI. METHODS: A multicenter cross-sectional project is planned, using quantitative (web survey) and qualitative (interview) methods in ten rehabilitation units from Norway, Sweden, United States, Israel, PR China, Russia and Palestine. Individual interviews will be conducted with ≥20 adolescents aged 13-17 years at least 6 months' post rehabilitation. RESULTS: Units involved will be described and compared, according to funding, attachment to an acute SCI unit, catchment area, number of beds, admittance and discharge procedures, availability of services, staff/patient ratio, content and intensity of rehabilitation programs, length of stay, measurement methods, follow-up services, health promotion services, and pediatric SCI prevention acts. The semi-structured interview guide will include experiences from acute care and primary rehabilitation, daily life, school, contact with friends, leisure time activities, peers, physical and psychological health, and the adolescents' plans for the future. CONCLUSION: Based on the present protocol, this project is likely to provide new insight and knowledge on pediatric SCI rehabilitation and increase the understanding of pediatric SCI in adolescents and their families internationally.

Validation of a novel cone tool for pinprick sensation examination in patients with spinal cord injury.

STUDY DESIGN: Psychometrics study. OBJECTIVE: The objective of this study was to introduce a novel tool for pinprick sensation examination and validate its usefulness in patients with spinal cord injury (SCI). SETTING: China Rehabilitation Research Center, Capital Medical University School of Rehabilitation Medicine, China. METHODS: A set of cone tools with different tapers (22.5°, 45°, 67.5°, 90°, 112.5°, 135°, 157.5°, and 180°) was made. The cone tool was validated first in 91 able-bodied individuals and then in 30 patients with SCI. The reliability and validity of the cone tool were analyzed by comparing the results of a pinprick sensation examination with the results of the International Standards for the Neurological Classification of SCI (ISNCSCI), the cone tool, and the thermal analyzer. RESULTS: The intraclass correlation coefficient (ICC) of the cone tool in able-bodied individuals was between 0.48 and 0.94 while that of the cone tool and the ISNCSCI tool ranged between 0.43 and 0.78. Pinprick sensation in patients with SCI can be graded into five levels using four tapers (22.5°, 45°, 67.5°, and 90°): normal, slight impairment, moderate impairment, severe impairment, and complete loss of sensation. CONCLUSION: This easy-to-use cone tool can produce a reliable semi-quantitative pinprick test result and is useful for pinprick sensation examination in patients with SCI.