Self-Assembly of Polyoxometalate-Based Sub-1†nm Polyhedral Building Blocks into Rhombic Dodecahedral Superstructures.

Self-assembly of subnanometer (sub-1 nm) scale polyhedral building blocks can yield some superstructures with novel and interesting morphology as well as potential functionalities. However, achieving the self-assembly of sub-1 nm polyhedral building blocks is still a great challenge. Herein, through encapsulating the titanium-substituted polyoxometalate (POM, K7 PTi2 W10 O40 ) with tetrabutylammonium cations (TBA+ ), we first synthesized a sub-1 nm rhombic dodecahedral building block by further tailoring the spatial distribution of TBA+ on the POM. Molecular dynamics (MD) simulations demonstrated the eight TBA+ cations interacted with the POM cluster and formed the sub-1 nm rhombic dodecahedron. As a result of anisotropy, the sub-1 nm building blocks have self-assembled into rhombic dodecahedral POM (RD-POM) assemblies at the microscale. Benefiting from the regular structure, Br- ions, and abundant active sites, the obtained RD-POM assemblies exhibit excellent catalytic performance in the cycloaddition of CO2 with epoxides without co-catalysts. This work provides a promising approach to tailor the symmetry and structure of sub-1 nm building blocks by tuning the spatial distribution of ligands, which may shed light on the fabrication of superstructures with novel properties by self-assembly.

Application of three-dimensional printed navigation templates to correct lower limb deformities in children by the guided growth technique.

Objective: Currently, individualized navigation templates are rarely applied in pediatric orthopedic surgery. This study aimed to explore the potential of navigation templates obtained using computer-aided design and three-dimensional (3D) printing to correct lower limb deformities in children by the guided growth technique. Methods: We prospectively studied 45 children with leg length discrepancy (LLD) or lower limb angular deformities, who underwent guided growth surgery involving 8-plate. In total, 21 and 24 children were included in the navigation template (group A) group and in the traditional surgery (group B) group, respectively. Mimics software was used for designing and printing navigation templates. The operation time, X-ray radiation exposure, damage to cartilage, and postoperative complications were recorded. Results: The mean operation time in groups A and B were 20.78 and 28.39 min, respectively, and the difference was statistically significant. Compared with group B, the intraoperative exposure of X-rays in group A was reduced by 25% on average. After 9-24 months of follow-up, the deformities were corrected in both groups. No significant differences in the treatment effect were noted between the groups, and no complications occurred. Conclusions: Using the individualized navigation template in the guided growth technique made the surgical procedure convenient and simple to perform. In addition, the operation time and intraoperative exposure to X-rays were reduced. We consider that 3D printed navigation templates can facilitate the accurate completion of corrective surgeries for lower limb deformities in children, which is worthy of promotion and application.

Atomically Dispersed Dual Metal Sites Boost the Efficiency of Olefins Epoxidation in Tandem with CO2 Cycloaddition.

Tandem catalysis provides an economical and energy-efficient process for the production of fine chemicals. In this work, we demonstrate that a rationally synthesized carbon-based catalyst with atomically dispersed dual Fe-Al sites (ADD-Fe-Al) achieves superior catalytic activity for the one-pot oxidative carboxylation of olefins (conversion ∼97%, selectivity ∼91%), where the yield of target product over ADD-Fe-Al is at least 62% higher than that of monometallic counterparts. The kinetic results reveal that the excellent catalytic performance arises from the synergistic effect between Fe (oxidation site) and Al sites (cycloaddition site), where the efficient CO2 cycloaddition with epoxides in the presence of Al sites (3.91 wt %) positively shifts the oxidation equilibrium to olefin epoxidation over Fe sites (0.89 wt %). This work not only offers an advanced catalyst for oxidative carboxylation of olefins but also opens up an avenue for the rational design of multifunctional catalysts for tandem catalytic reactions in the future.

Regulating Dendrite-Free Zn Deposition by a Self-Assembled OH-Terminated SiO2 Nanosphere Layer toward a Zn Metal Anode.

Zn dendrite growth during repeated plating and stripping of a Zn metal anode often causes short-circuiting by puncturing the separator. Herein, we propose a separator modification strategy to regulate the Zn-ion flux and achieve uniform Zn deposition through the OH-terminated SiO2 nanosphere coating. The interspaces between the uniform SiO2 nanospheres construct a network of Zn-ion transport channels, and the negatively charged hydroxyl groups on the surface of SiO2 nanospheres can electrostatically attract the Zn ions to direct the ion migration. The negative charges on SiO2 nanospheres are retained at a higher pH, which enables the SiO2 coating to consistently regulate the Zn-ion flux in the operating pH range of the Zn stripping/plating process. With a uniform Zn deposition guided by the SiO2 coating, the dendrite formation is suppressed and the side reactions are alleviated. As a result, the Zn||Zn symmetric cell achieves a cyclic life of 1000 h at both 3 and 5 mA cm-2. Meanwhile, the Zn||Cu asymmetric cell is able to maintain a Coulombic efficiency of 99.62% at 1 mA cm-2 for 2000 cycles, which outperforms many previously reported strategies.

Limited Open Reduction and Transepiphyseal Intramedullary Kirschner Wire Fixation for Treatment of Irreducible Distal Radius Diaphyseal Metaphyseal Junction Fracture in Older Children.

Objective: This study aimed to compare limited open reduction and transepiphyseal intramedullary fixation with Kirschner wire (LOR-TIKW) versus open reduction and internal fixation with plate and screw (ORIF-PS) for treatment of irreducible distal radius diaphyseal-metaphyseal junction (DMJ) fracture in older children. Methods: Data of children (aged 10-14 years) treated in our hospital for distal radius DMJ fractures with LOR-TIKW or ORIF-PS from January 2018 to December 2019 were retrospectively analyzed. Follow-up was until radiographic union. Demographic, clinical, and radiographic data; treatment cost; healing time; functional outcome (by Price criteria); complications; and postoperative angulation and displacement were compared between children treated by the two methods. Statistical analysis was performed with alpha set at P < 0.05. Results: A total of 26 children were included: 14 treated with LOR-TIKW and 12 with ORIF-PS. Operation time was less (22.1 min vs. 46.7 min, P < 0.0001), surgical incision smaller (2.43 cm vs. 5.00 cm, P < 0.0001), cost of internal fixation lower (US$, 40.6 vs. 2020, P < 0.0001), and healing time shorter (4.79 weeks vs. 5.64 weeks, P = 0.03) with LOR-TIKW; however, postoperative fracture angulation was slightly larger (1.07° vs. 0.83°, P = 0.85) and displacement slightly more (0.86 mm vs. 0.58 mm, P = 0.44) in the LOR-TIKW group. Rate of union, functional outcome, and complications were not significantly different between the groups. Conclusion: For irreducible DMJ fracture of distal radius in older children, LOR-TIKW appears to be a promising method with several advantages over ORIF-PS.

Closed Reduction Percutaneous Intramedullary Fixation with Kirschner Wires in 4 Children with Displaced Fractures of the Distal Humerus.

BACKGROUND This study describes the use of closed reduction percutaneous intramedullary fixation with Kirschner wires in 4 children with displaced metaphyseal-diaphyseal junction (MDJ) fractures of the distal humerus. MATERIAL AND METHODS Between August 2016 and August 2019, 4 patients (3 boys and 1 girl), whose mean age was 4 years 5 months (range: 3 years 6 months to 5 years 4 months), with displaced MDJ fractures of the distal humerus were treated using closed reduction percutaneous intramedullary fixation with Kirschner wires. Three of the fractures were oblique and 1 was transverse. The operation time and the frequency of intraoperative fluoroscopy were recorded. All children were followed up for greater than 18 months, taking anteroposterior and lateral radiographs of the elbow joint to evaluate the outcomes. At the last follow-up, the Flynn elbow joint function score was used to evaluate clinical outcomes, and complications were recorded. RESULTS The mean operation time was 37.5 min (range: 35-40 min) and the frequency of intraoperative fluoroscopy was 11.7 times (range: 8-15 times). All of the fractures were confirmed to be healed based on radiographic results at 4 weeks after surgery. At the last follow-up, 4 children had normal elbow joint motion without elbow deformity. The Flynn score showed their outcomes were excellent. CONCLUSIONS Closed reduction percutaneous intramedullary fixation using Kirschner wires was an effective treatment for displaced MDJ fractures of the distal humerus in the 4 children described and was shown to be easy to perform with a short operation time.

Ligand Defect Density Regulation in Metal-Organic Frameworks by Functional Group Engineering on Linkers.

Defects in solid materials vitally determine their physicochemical properties; however, facile regulation of the defect density is still a challenge. Herein, we demonstrate that the ligand defect density of metal-organic frameworks (MOFs) with a UiO-66 structural prototype is precisely regulated by tuning the linker groups (X = OMe, Me, H, F). Detailed analyses reveal that the ligand defect concentration is positively correlated with the electronegativity of linker groups, and Ce-UiO-66-F, constructed by F-containing ligands and Ce-oxo nodes, possesses the superior ligand defect density (>25%) and identifiable irregular periodicity. The increase in ligand defect density results in the reduction of the valence state and the coordination number of Ce sites in Ce-UiO-66-X, and this merit further validates the relationship between the defective structure and catalytic performance of CO2 cycloaddition reaction. This facile, efficient, and reliable strategy may also be applicable to precisely constructing the defect density of porous materials in the future.

miR-130a alleviates neuronal apoptosis and changes in expression of Bcl-2/Bax and caspase-3 in cerebral infarction rats through PTEN/PI3K/Akt signaling pathway.

Effect of micro ribonucleic acid (miR)-130a on neuronal apoptosis in rats with cerebral infarction (CI) was studied to explore whether phosphatase and tensin homolog deleted on chromosome ten (PTEN)/phosphatidylinositol 3-hydroxy kinase (PI3K)/protein kinase B (Akt) is involved in the regulation of neuronal apoptosis. Thirty-six Sprague-Dawley (SD) rats were randomly divided into blank control group, model group and miR-130a low-expression group. miR-130a was determined by quantitative polymerase chain reaction (qPCR), the content of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and IL-10 was detected using the enzyme-linked immunosorbent assay (ELISA) kits, and the neuronal apoptosis level in each group was determined through terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining. The neurobehavioral score was significantly lower in model group than that in blank control group (P<0.01), while it was significantly higher in miR-130a low-expression group than that in model group (P<0.01). Compared with blank control group, the model group had obviously increased content of TNF-α and IL-6 (P<0.01), decreased content of IL-10 (P<0.01), more apoptotic neurons (P<0.01), higher expression of caspase-3 (P<0.01), and obviously lower Bcl-2/Bax (P<0.01). Moreover, expression of phosphorylated (p)-PTEN, PI3K and p-Akt in brain tissues was remarkably lower in the model group than those in the blank control group (P<0.01). The expression level of miR-130a in brain tissues of CI rats is significantly increased. miR-130a promotes the release of inflammatory factors and facilitates neuronal apoptosis through suppressing the PTEN/PI3K/Akt signaling pathway.

Downregulated miRNA-324-5p aggravates neuronal injury induced by oxygen-glucose deprivation via modulating RAN.

Differentially expressed miRNAs in the GEO profile of ischemic stroke were analyzed to clarify the specific role of microRNA-324-5p (miRNA-324-5p) in ischemic stroke and the potential mechanism. After screening out miRNA-324-5p, its level in peripheral blood of stroke patients and in vitro oxygen-glucose deprivation (OGD)-induced primary rat neurons was determined by quantitative real-time polymerase chain reaction (qRT-PCR). Regulatory effects of miRNA-324-5p on viability, and apoptosis of OGD-induced neurons were evaluated by CCK-8 and Annexin V fluorescein isothiocyanate (FITC)/propidium iodide (PI) staining, respectively. Glucose uptake and caspase-3 activity in OGD-induced neurons transfected with miRNA-324-5p mimics or inhibitor were also examined. The binding of miRNA-324-5p to its target gene RAN was analyzed by dual-luciferase reporter gene assay and western blot analysis. By analyzing the data of GSE46266 profile, miRNA-324-5p expression was shown markedly lower in MCAO rats relative to controls. Identically, we also observed the downregulated miRNA-324-5p in peripheral blood of stroke patients and in vitro OGD-induced primary neurons. Overexpression of miRNA-324-5p accelerated viability, induced apoptosis and strengthened glucose uptake ability of OGD-induced neurons. Knockdown of miRNA-324-5p, conversely, obtained the opposite results. Furthermore, we confirmed the binding of miRNA-324-5p to RAN, the target gene that was negatively regulated by miRNA-324-5p. Importantly, RAN overexpression partially reversed the regulatory effect of miRNA-324-5p on viability and glucose uptake of OGD-induced neurons. miRNA-324-5p is downregulated after ischemic stroke, which aggravates the disease condition by inhibiting neuronal proliferation and glucose uptake via upregulating RAN.

Binder-free V2O5/CNT paper electrode for high rate performance zinc ion battery.

Organic compounds, such as polyvinylidene fluoride (PVDF), have been widely used as a binder in battery electrode preparations. While such an approach does not have a significant impact on the performance of the batteries that utilize low valence ions, such as the Li ion battery (LIB), the diffusion of high valence ions (such as Zn2+) will be severely impaired. This will be especially pronounced if the polymeric binder contains highly electronegative atoms, such as fluorine. The high charge density ions, such as Zn2+, tend to adsorb onto these electronegative atoms, thus the mobility of these ions across the material is inevitably affected. As such, it becomes highly necessary to consider the binder-free electrode architecture when designing a high rate performing and cycling-stable zinc ion battery (ZIB) cathode. Herein, this work demonstrates an improved Zn ion battery by adopting a freestanding electrode. The obtained V2O5/CNT paper electrode delivers a specific capacity of 312 mA h g-1, while achieving a respectable 75% retention in capacity after increasing the current density by 10-fold. Furthermore, excellent cycling stability is recorded with 81% capacity retention after 2000 cycles at 1.0 A g-1. Thus, this work clearly demonstrated that the freestanding electrode is a promising approach for high valence ion batteries.

Bi2S3 for Aqueous Zn Ion Battery with Enhanced Cycle Stability.

Aqueous Zn ion batteries (ZIBs) are promising in energy storage due to the low cost, high safety, and material abundance. The development of metal oxides as the cathode for ZIBs is limited by the strong electrostatic forces between O2- and Zn2+ which leads to poor cyclic stability. Herein, Bi2S3 is proposed as a promising cathode material for rechargeable aqueous ZIBs. Improved cyclic stability and fast diffusion of Zn2+ is observed. Also, the layered structure of Bi2S3 with the weak van der Waals interaction between layers offers paths for diffusion and occupancy of Zn2+. As a result, the Zn/Bi2S3 battery delivers high capacity of 161 mAh g-1 at 0.2 A g-1 and good cycling stability up to 100 cycles with ca. 100% retention. The battery also demonstrates good cyclic performance of ca. 80.3% over 2000 cycles at 1 A g-1. The storage mechanism in the Bi2S3 cathode is related to the reversible Zn ion intercalation/extraction reactions and the capacitive contribution. This work indicates that Bi2S3 shows great potential as the cathode of ZIBs with good performance and stability.

The effects of antiplatelet agents on platelet-leukocyte aggregations in patients with acute cerebral infarction.

BACKGROUND: Studies have shown that platelet-leukocyte aggregates (PLA) are sensitive to platelet activation which might exist before the onset of cerebral infarction. In this study, we investigated the formation of PLA in patients with cerebral infarction and the effects of antiplatelet agents on PLA. METHODS: The level of soluble P-selectin, C-reaction protein, platelet aggregation rate and leukocyte-platelet aggregations were measured in 40 patients with acute cerebral infarction and 20 normal controls. The 40 patients were randomly assigned to two treatment groups: aspirin group (n = 20) and clopidogrel group (n = 20). Both groups were monitored for Scandinavian stroke scale (SNSS), soluble P-selectin, serum C-reaction protein, platelet aggregation rate and PLA before and after the treatment. Flow cytometry was used to detect the levels of PLA in the blood. RESULTS: The percentage of platelet-monocyte aggregates (PMA) in patients with cerebral infarction was significantly increased compared with the controls (P < 0.001), which was positively correlated to soluble P-selectin, C-reaction protein and platelet aggregation rate (P < 0.05). After the treatment, the levels of PMA and platelet aggregation rate were decreased in both groups (P < 0.05). The level of PMA and platelet aggregation rate in the clopidogrel group was significantly lower than that in the aspirin group (P < 0.05). CONCLUSIONS: PMA are a sensitive biomarker to platelet activation in patients with cerebral infarction. In addition, although both aspirin and clopidogrel lowered the level of PMA, clopidogrel is a more effective treatment than aspirin in inhibiting platelet activation.

[The changes and effects of antiplatelet agents on platelet-leukocyte aggregation in patients with acute cerebral infarction].

OBJECTIVE: To investigate the changes of platelet-leukocyte aggregation (PLA) in patients with cerebral infarction and the effects of antiplatelet agents on it. METHODS: The levels of plasma soluble P-selectin (sP-sel), serum C-reactive protein (CRP), platelet aggregation rate (PAR) and PLA were measured in 40 patients with acute cerebral infarction and 20 cases of controls. The 40 patients with cerebral infarction were randomly divided into aspirin-treated group (20 cases) and clopidogrel-treated group (20 cases) scandinavian neurological stroke score (SNSS), plasma sP-sel, serum CRP, PAR and PLA were observed before and after the treatment. RESULTS: Compared with controls, the percentage of monocyte-platelet aggregation (PMA) was significantly increased in the patients (P < 0.001). The level of plasma sP-sel, serum CRP and PAR in the case group were significantly greater than those in the control group (P < 0.05). The level of PMA was positively related with the plasma sP-sel, serum CRP and PAR in cerebral infarction patients before treatment (P < 0.05), and it showed a significant inverse correlation between the percentage of PMA and the score of SNSS (P < 0.05). After treatment, the levels of PMA and PAR were decreased in both groups of cerebral infarction patients (P < or = 0.001), and the level of PMA and PAR (ADP) in clopidogrel-treated group was lower than those in aspirin-treated group (P < 0.05). However, the CRP in the patients was no significant difference before and after treatment. The level of sP-sel was no significant difference before and after treatment in aspirin-treated group, but it was significantly decreased after treatment in clopidogrel-treated group (P < 0.001). CONCLUSIONS: The levels of PMA in patients with cerebral infarction was significantly higher than in the controls. PMA may be a sensitive marker of platelet activation. Aspirin and Clopidogrel could decline the level of PMA in the patients with acute cerebral infarction, and Clopidogrel was more effective than aspirin in inhibiting the activation of platelet.