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Objective To verify the function of exosomes from 293T cells over-expressing membrane-localized IL-3 in vitro, so as to lay a foundation for in vivo function verification in animal models of Alzheimer′s disease. Methods Using the patented structure of the group, a recombinant IL-3 lentiviral vector was constructed and virus-infected 293T cells were packaged. Stable cell strain over-expressing IL-3 was screened. The membrane localization of IL-3 was verified by flow cytometry and immuno-fluorescence. Il-3-exosomes were purified by ultra filtration centrifugation, the exosmic morphology was observed by transmission electron microscope, the size distribution and concentration of exosomes were detected by nano-flow analysis, and the expression of IL-3 and exosome related marker proteins were detected by Western blot. The effect of BV-2 on the phagocytosis of Aβ amyloid was detected by immuno-fluorescence. Results Through vector construction, virus infection, screening and verification of puromycin, 293T cell strain with stable over-expression membrane-anchored IL-3 was obtained. The purified exosomes were collected and the structures of double-layer membrane vesicles with a diameter of 50-100 nm were observed under transmission electron microscope. Western blot results proved the presence of CD63, ALIX, TSG101 and other exosome marker proteins and these molecules were rich in IL-3 as compared with the control, that suggested the successful purification of IL-3-exosomes. The results of immuno-fluorescence assay showed that IL-3-exosomes promoted the phagocytosis of Aβ amyloid by BV-2 cells in vitro. Conclusions The gene modified 293T cell exosomes membrane-anchored expression of IL-3 can play a role of both IL-3 and exosomes in vitro, which promote the phagocytosis of microglia, there for provides a new idea for the clinical treatment of Alzheimer′s disease.

The catalytic performance of spinel oxide NiCo2O4 for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) was investigated. It shows that NiCo2O4 synthesized via hydrothermal treatment at 90 ℃ followed by calcination at 350 ℃ exhibits excellent catalytic activity. Furthermore, Fe-doped MnO2 (marked as Fe-M) was introduced as a modifier to further improve the performance of NiCo2O4. As expected, the 20% Fe-M hybrid catalyst (NiCo2O4 modified with 20 wt% Fe-M) displays the best ORR and OER catalytic activity. This is evidenced by its high OER current density of 265 mA cm−2, high ORR current density of 220 mA cm−2, low OER Tafel slope of 119 mV dec−1, low ORR Tafel slope of 167 mV dec−1. These exceptional results can be attributed to the synergistic effect between NiCo2O4 and Fe-M. Based on synergistic effect, the 20% Fe-M hybrid catalyst exhibits the best catalytic activity for oxygen evolution reaction and oxygen reduction reaction. [ABSTRACT FROM AUTHOR]

Developing an efficient electrocatalyst for the oxygen electrode is a significant challenge in the field. In this study, Co–N co-doped carbon (denoted as CZIF-67) is used as modifier to enhance the catalytic activity of the spinel oxide NiCo2O4. Among all the catalysts synthesized, the composite catalyst containing 10% CZIF-67 (where CZIF-67 constitutes 10% of the total mass) exhibits the highest catalytic activity for both the oxygen evolution reaction and the oxygen reduction reaction. This is evidenced by the largest current densities of 275.6 mA·cm−2 and 235.6 mA·cm−2 at the cutoff voltage of 1.9268 V (vs. RHE) and 0.3268V (vs. RHE). XPS characterization showed the surface element composition and valence analysis of 10% CZIF-67, which revealed the synergistic reaction between CZIF-67 and NiCo2O4 to a certain extent. Electrochemical impedance spectroscopy (EIS) results indicate that the charge transfer resistance of 10% CZIF-67 catalyst is the lowest, suggesting a faster charge transfer rate. It can be attributed to the synergistic effects between appropriate amount of CZIF-67 and the spinel oxide NiCo2O4. Additionally, the large specific surface and the porous structure of CZIF-67 can provide more active sites for the reactions. [ABSTRACT FROM AUTHOR]

The perovskite oxide La0.4Sr0.6Co0.8Ni0.2O3 was prepared by sol–gel method and applied to the oxygen electrode. To further improve its catalytic activity, N-doped graphene (NG) was coupled with La0.4Sr0.6Co0.8Ni0.2O3. The samples were characterized structurally and morphologically using XRD, SEM, and FT-IR. The electrochemical test results showed that the current densities for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) catalyzed by the hybrid catalyst 10%NG (NG in total catalyst mass ratio of 10%) were 359 mA·cm−2 (0.9 V vs. Hg/HgO) and 393 mA·cm−2 (− 0.6 V vs. Hg/HgO), respectively. The excellent ORR/OER activity and stability of the hybrid catalyst can be attributed to the synergistic effect between La0.4Sr0.6Co0.8Ni0.2O3 and NG. [ABSTRACT FROM AUTHOR]

Objective: To analyze the factors affecting the prognosis of patients with knee osteoarthritis, and to construct a nomogram prediction model in conjunction with multi-dimensional clinical indicators., Methods: The clinical data of 234 patients with knee osteoarthritis who were treated in our hospital from January 2015 to June 2021 were retrospectively analyzed, including 126 males and 108 females；age more than 60 years old for 135 cases, age less than 60 years old for 99 cases. Lysholm knee function score was used to evaluate the prognosis of the patients, and the patients were divided into good prognosis group for 155 patients and poor prognosis group for 79 patients according to the prognosis. The clinical data of the subjects in the experimental cohort were analyzed by single factor and multiple factors. The patients were divided into experimental cohort and verification cohort, the results of the multiple factor analysis were visualized to obtain a nomogram prediction model, the receiver operating characteristic curve（ROC）, calibration curve and decision curve were used to evaluate the model's discrimination, accuracy and clinical benefit rate., Results: The results of multivariate analysis showed that smoking, pre-treatment K-L grades of Ⅲ to Ⅳ, and high levels of interleukin 6 （IL-6） and matrix metallo proteinase-3 （MMP-3） were risk factors for the prognosis of patients with knee osteoarthritis. ROC test results showed that the area under the curve of the nomogram model in the experimental cohort and validation cohort was 0.806[95% CI （0.742, 0.866）] and 0.786[（95% CI （0.678, 0.893）], respectively. The results of the calibration curve showed that the Brier values of the experimental cohort and verification cohort were 0.151 points and 0.134 points, respectively. When the threshold probability value in the decision curve was set to 31%, the clinical benefit rates of the experimental cohort and validation cohort were 51% and 56%, respectively., Conclusion: The prognostic model of patients with knee osteoarthritis constructed based on multi-dimensional clinical data has both theoretical and practical significance, and can provide a reference for taking targeted measures to improve the prognosis of patients.