Mesoporous multi-shelled hollow resin nanospheres with ultralow thermal conductivity.

Hollow nanostructures exhibit enclosed or semi-enclosed spaces inside and the consequent features of restricting molecular motion, which is crucial for intrinsic physicochemical properties. Herein, we developed a new configuration of hollow nanostructures with more than three layers of shells and simultaneously integrated mesopores on every shell. The novel interior configuration expresses the characteristics of periodic interfaces and abundant mesopores. Benefiting from the suppression of gas molecule convection by boundary scattering, the thermal conductivity of mesoporous multi-shelled hollow resin nanospheres reaches 0.013 W m-1 K-1 at 298 K. The designed interior mesostructural configuration of hollow nanostructures provides an ideal platform to clarify the influence of nanostructure design on intrinsic physicochemical properties and propels the development of hollow nanostructures.

Ketamine Promotes LPS-Induced Pulmonary Autophagy and Reduces Apoptosis through the AMPK/mTOR Pathway.

To explore the protective effect of ketamine on acute lung injury (ALI) in sepsis mice regarding the autophagy and apoptosis, lipopolysaccharide (LPS) was used to construct a sepsis-induced ALI model. In in vivo experiments, ketamine at a concentration of 20 mg/kg was injected before modeling. The serum levels of inflammatory factors IL-1ß, IL-6, and TNF-α were detected by enzyme-linked immunosorbent assay (ELISA) kit. At the same time, quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect apoptosis-related factors Bax and Bcl-2 and autophagy-related factors Beclin-1 and P62. In in vitro experiment, firstly, Cell Counting Kit-8 (CCK8) assay was used to detect the cell viability and identify optimal concentration of ketamine. TUNEL staining, Western blotting (WB), and qRT-PCR were used to detect alveolar type II epithelial cells (AEC II) AEC II cell apoptosis. The content of inflammatory factors in the cell supernatant was detected by kits and the autophagy intensity of AEC II cells was detected by PCR and WB. At the same time, the expression changes of AMPK/mTOR pathway were detected by WB technology. Compared with the Sham group, the dry-wet ratio of the lung tissue in the LPS group was obviously increased, the expression of inflammatory factors in the serum was upregulated, and apoptosis and autophagy activation occurred. In the LPS + ketamine group, ketamine significantly promoted autophagy intensity and inhibited inflammatory response, thereby reducing apoptosis. In vitro, 1 mmol/L ketamine can effectively improve the viability of AEC II cells after LPS treatment, promote autophagy, and decrease cell apoptosis. And we found that the above-mentioned effect of ketamine was by regulating the activation of AMPK/mTOR pathway. In this study, we demonstrated that LPS treatment can induce inflammation and autophagy and induce apoptosis in lung cells. In contrast, AMPK expression was activated after ketamine treatment, inhibiting the mTOR pathway and promoting autophagy, thereby alleviating the apoptosis of AEC II cells.

MiR-181a reduces radiosensitivity of non-small-cell lung cancer via inhibiting PTEN.

BACKGROUND: The aim of this study is to explore the effect of micro ribonucleic acid (miR)-181a on the radiosensitivity of non-small cell lung cancer (NSCLC) and its potential mechanism of action. METHODS: The differentially expressed miRNAs were screened in lung cancer tissues of radiotherapy-resistant and non-radiotherapy-resistant NSCLC patients, and verified via reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Next, the effects of different miRNA expressions on patients' survival time were discussed, and target genes of miR-181a were predicted. The effect of miR-181a expression on radiosensitivity was determined using cell counting kit-8 (CCK-8) assay and flow cytometry. The direct target of miR-181a was verified via luciferase reporter assay. Phosphatase and tensin homolog deleted on chromosome ten (PTEN) was overexpressed using lentiviruses, and then whether miR-181a reduces radiosensitivity via targeting PTEN was detected via CCK-8 assay and flow cytometry. Finally, Western blotting was performed to detect the protein expression of PTEN. RESULTS: The screening results of microarray expression profile assay revealed that 15 miRNAs had significant differences in lung cancer tissues of radiotherapy-resistant NSCLC patients compared with those in non-radiotherapy-resistant NSCLC patients. The results of RT-qPCR showed that hsa-miR-181a, hsa-miR-199b, hsa-miR-489 and hsa-miR-589 were significantly up-regulated in the lung cancer tissues of radiotherapy-resistant NSCLC patients compared with those in non-radiotherapy-resistant NSCLC patients. In addition, it was found that the survival time of NSCLC patients was obviously prolonged in hsa-miR-181a low-expression group and hsa-miR-589 high-expression group, but hsa-miR-489 and hsa-miR-199b had no significant influence on the survival time of NSCLC patients. According to KEGG enrichment analysis, the target genes of miR-181a were evidently enriched in the phosphatidylinositol 3-hydroxy kinase (PI3K)/protein kinase B (AKT) signaling pathway, NSCLC signaling pathway and other cancer signaling pathways. Under the radiation dose of 2, 4, 6 and 8 Gy, the survival rate of A549 cells rose in miR-181a mimic group, but declined in miR-181a inhibitor group. Moreover, compared with that in model group, the radiotherapy-induced apoptosis was markedly inhibited in miR-181a mimic group, but markedly promoted in miR-181a inhibitor group. It was also observed that the response of cells to radiotherapy-induced apoptosis was remarkably weakened in miR-181a mimic + PTEN overexpression group compared with that in miR-181a mimic group. Finally, miR-181a mimic group had a significantly lower protein expression of PTEN and significantly higher protein expressions of CXC chemokine receptor 4 (CXCR4), phosphorylated signal transducer and activator of transcription 3 (p-STAT3), p-AKT1 and p-mammalian target of rapamycin (mTOR) than model group, while miR-181a inhibitor group had the opposite protein expressions. The protein expressions of CXCR4, p-STAT3, p-AKT1 and p-mTOR were obviously lower in miR-181a mimic + PTEN overexpression group than those in miR-181a mimic group. CONCLUSIONS: MiR-181a reduces the radiosensitivity of NSCLC via inhibiting PTEN expression.

Surface Immobilization of Transition Metal Ions on Nitrogen-Doped Graphene Realizing High-Efficient and Selective CO2 Reduction.

Electrochemical conversion of CO2 to value-added chemicals using renewable electricity provides a promising way to mitigate both global warming and the energy crisis. Here, a facile ion-adsorption strategy is reported to construct highly active graphene-based catalysts for CO2 reduction to CO. The isolated transition metal cyclam-like moieties formed upon ion adsorption are found to contribute to the observed improvements. Free from the conventional harsh pyrolysis and acid-leaching procedures, this solution-chemistry strategy is easy to scale up and of general applicability, thus paving a rational avenue for the design of high-efficiency catalysts for CO2 reduction and beyond.