Modulating Electronic Environment of Ru Nanoclusters via Local Charge Transfer for Accelerating Alkaline Water Electrolysis.

Compared to platinum catalysts, ruthenium (Ru) is disclosed as a promising alternative for alkaline water electrolysis due to its similar hydrogen adsorption energy and relatively lower water dissociation barrier. However, in the challenging alkaline media, the dissatisfied Volmer step during water dissociation of Ru metal prohibits its practical applications. Here, a new pathway to modulate the electronic environment of Ru catalysts via a local charge transfer strategy for tuning the water dissociation kinetics and accelerating the alkaline water electrolysis is proposed. The obtained catalysts are engineered by assembling and subsequently pyrolyzing the layer-stacked and 2D porphyrin-based Ru-N coordination polymers on nanocarbon supports. Benefiting from the well-defined Ru nanocluster-Nx -coordination bonds (Runc -Nx ), unique electronic environments, and local charge transfer properties, the catalysts exhibit the exceptional activity of 17 mV overpotential at 10 mA cm-2 and robust stability in water, which is more efficient than state-of-the-art Ru catalysts. The theoretical calculation suggests that the Runc -Nx sites enhance the nucleophilic attack of water and weaken the HOH bond. This study manifests that tailoring the bond environments of Ru clusters can significantly modulate their intrinsic catalytic activities and stabilities, which may open new avenues for developing high-active and durable catalysts for water electrolysis.

Conjugated Coordination Porphyrin-based Nanozymes for Photo-/Sono-Augmented Biocatalytic and Homologous Tumor Treatments.

Porphyrin-based nanozymes (Porzymes) have shown promising application potential to fight against tumors using catalytically generated reactive oxygen species from the excessively produced H2O2 in the tumor microenvironment. However, the low coordination porphyrin (CP) loading ratio, difficult controllable nanostructure, low bioavailability, and low biocatalytic activities of current established Porzymes have severely limited their antitumor applications. Here, a novel malignant melanoma cell membrane-coated Pd-based CP nanoplatform (Trojan Porzymes) has been synthesized for biocatalytic and homologous tumor therapies. The Trojan Porzymes exhibit a high CP loading ratio, uniform nanoscale size, single-atom nanostructure, homologous targeted ability, and high-efficiency photo/sono-augmented biocatalytic activities. The enzyme-like biocatalytic experiments display that the Trojan Porzymes can generate abundant •OH via chemodynamic path and 1O2 via visible light or ultrasound excitation. Then we demonstrate that the Trojan Porzymes show homologous targeting ability to tumor cells and can achieve efficient accumulation and long-term retention in cancer tissues. Our in vivo data further disclose that the photo/sono-assisted chemodynamic therapies can significantly augment the treatment efficiency of malignant melanoma. We believe that our work will afford a new biocatalytic and homologous strategy for future clinical malignant melanoma treatments, which may inspire and guide more future studies to develop individualized biomedicine in precise tumor therapies.

Pd-Single-Atom Coordinated Biocatalysts for Chem-/Sono-/Photo-Trimodal Tumor Therapies.

The diversity, complexity, and heterogeneity of malignant tumor seriously undermine the efficiency of mono-modal treatment. Recently, multi-modal therapeutics with enhanced antitumor efficiencies have attracted increasing attention. However, designing a nanotherapeutic platform with uniform morphology in nanoscale that integrates with efficient chem-/sono-/photo-trimodal tumor therapies is still a great challenge. Here, new and facile Pd-single-atom coordinated porphyrin-based polymeric networks as biocatalysts, namely, Pd-Pta/Por, for chem-/sono-/photo-trimodal tumor therapies are designed. The atomic morphology and chemical structure analysis prove that the biocatalyst consists of atomic Pd-N coordination networks with a Pd-N2 -Cl2 catalytic center. The characterization of peroxidase-like catalytic activities displays that the Pd-Pta/Por can generate abundant •OH radicals for chemodynamic therapies. The ultrasound irradiation or laser excitation can significantly boost the catalytic production of 1 O2 by the porphyrin-based sono-/photosensitizers to achieve combined sono-/photodynamic therapies. The superior catalytic production of •OH is further verified by density functional theory calculation. Finally, the corresponding in vitro and in vivo experiments have demonstrated their synergistic chem-/sono-/photo-trimodal antitumor efficacies. It is believed that this study provides new promising single-atom-coordinated polymeric networks with highly efficient biocatalytic sites and synergistic trimodal therapeutic effects, which may inspire many new findings in reactive oxygen species-related biological applications across broad therapeutics and biomedical fields.

The clinical effect and safety of the treatment of tibia intercondylar eminence fracture with cannulated screw and suture fixation under arthroscope: Protocol for a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: The clinical effects and safety over the treatment of tibia intercondylar eminence fracture (TIEF) with cannulated screw and suture fixation were evaluated under arthroscope systematically, providing evidence-based medical support for the selection of surgical methods in terms of minimally invasive arthroscopic treatment for TIEF. METHODS: The English databases of PubMed, EMBASE, Cochrane Library, CNKI, SinoMed, VIP, and Wanfang databases were searched by computer. The randomized controlled trials were conducted to compare the clinical effects of TIEF with cannulated screw and suture fixation under arthroscope. The retrieval period is from the beginning of database building to January 2020. There is no language restriction. Chinese databases are searched by keywords, while English databases are searched by the combination of subject words and free words. According to the retrieval strategy, the two evaluators will lead the conforming documents into Note Express for repeated literature screening, and the two evaluators will extract and cross-check the conforming documents according to the pre-designed data extraction table. Two researchers adopted the modified Jadad scale independently to evaluate the quality of the literature. The RevMan 5.3 version software provided by the Cochrane Collaboration Network was adopted for statistical analysis. RESULTS: The study will strictly review and extract the data included in the literature, and scientifically make statistical analysis for the pre-set outcome indicators. All the research processes will be conducted in strict accordance with the guidance of system evaluation. In this study, the differences between cannulated screw fixation and suture fixation under arthroscopy will be evaluated by comparing the relevant outcome indicators. All the results of this study will be published openly in a highly influential professional academic journal. CONCLUSION: The paper adopted Cochrane system evaluation method to collect and sort out the published literature about the treatment of tibial eminence fracture between cannulated screw fixation and suture fixation under arthroscopy, and to compare the clinical efficacy and safety of the two fixation methods utilizing meta-analysis and comparison of related outcome indicators. Through this study, we will draw a positive conclusion, which will provide a basis for the better treatment of tibial eminence fracture. PROSPERO REGISTRATION NUMBER: PROSPERO CRD42020168433.