Objective:To investigate the protective effect of a composite hydrogel against hydrogen peroxide(H2O2)-induced oxidative stress injury in the cardiomyocytes,and to clarify its possible mechanism.Methods:The mice were subcutaneously injected with 100 μL of hydrogel.After normal feeding for 1,14,and 28 d,the mice were sacrificed.Tissue samples were collected and subjected to HE staining to observe the histocompatibity of the hydrogel.The primary cardiomyocytes isolated from 1-day-old SD rats were used to establish an oxidative stress injury model.The primary cardiomyocyties were divided into control,H2O2 and H2O2+Hydrogel groups.The primary cardiomyocytes in control group were cultured normally,the primary cardiomyocytes in H2O2 group were treated with 200 μmol·L-1 H2O2 for 24 h,and the primary cardiomyocytes in H2O2+Hydrogel group were incubated with 1 g·L-1 composite hydrogel and 200 μmol·L-1 H2O2 for 24 h.The viabilities of cardiomyocytes in various groups were assessed by cell counting kit-8(CCK-8)method.Dihydroethidium(DHE)and 2',7'-dichlorodihydrofluorescein diacetate(DCFH-DA)staining were used to assess the reactive oxygen species(ROS)levels in the cells.The expressions of filamentous actin(F-actin)in the cells in various groups were detected by phalloidin fluorescence staining;the expressions of connexin 43(Cx43)and cardiac troponin T(cTnT)proteins in the cardiomyocytes in various groups were detected by immunofluorescence method.The apoptotic rates of cardiomyocytes in various groups were assessed with TUNEL staining method.The expression levels of apoptosis-related proteins B-cell lymphoma-2(Bcl-2)and Bcl-2-associated X protein(Bax)in the cardiomyocytes in various groups were assessed by Western blotting method.Results:The HE staining results showed that the inflammatory cells around the implanted hydrogel were less infiltrated,and the inflammatory reaction of subcutaneous implantation was less.Compared with control group,the viability of cardiomyocytes in H2O2 group was significantly decreased(P＜0.05),the level of ROS in the cells was increased(P＜0.05),the expression levels of Cx43,cTnT and F-actin proteins in the cells were decreased(P＜0.001),the apoptosis rate of cardiomyocytes were decreased(P＜0.01),the expression level of Bcl-2 protein in the cells was increased(P＜0.001),and the expression level of Bax protein was decreased(P＜0.01).Compared with H2O2 group,the viability of cardiomyocytes was significantly increased(P＜0.05),the level of ROS in the cells was decreased(P＜0.01),the expression levels of cTnT,Cx43 and F-actin proteins were increased(P＜0.01),the apoptotic rate of cardiomyocytes were significantly decreased(P＜0.001),the expression level of Bcl-2 protein in the cells were decreased(P＜0.01),and the expression level of Bax protein was increased(P＜0.01).Conclusion:Hydrogel may promote the expression of cardiomyocyte-related proteins by scavenging ROS in the environment and inhibit the cardiomyocyte apoptosis to achieve the protective effect on the cardiomyocytes under oxidative stress.

Objective:To explore a blood cell recognition algorithm that combined threshold image segmentation with deep learning in conventional image processing,so as to be used in automatic recognition and classification of blood cell smears.Method:Global threshold segmentation was used to extract blood cells from blood cell smears and to store them separately.The segmented cell images were manually labeled and classified so as to reduce the requirements for hardware in subsequent processing.The deep learning training of labeled images was on the basis of the GoogLeNet pre training model,which could generate deep learning model of automatic recognition that could be used in the images of blood cell smear.The trained model could be used to evaluate the test set,and generate confusion matrix and area under curve(AUC)value of receiver operating characteristic(ROC)curve.Result:This preprocessing has been proven that it can improve the training of deep learning model,and the subsequent recognition speed of using model can exceed over 10 times.Using the online image dataset Raabin WBC Data of blood cell smear,the accuracy of model training reached to 93.06%.Both of them obtained favorable results.Conclusion:The blood cell recognition algorithm based on the combination of threshold image segmentation and deep learning can greatly improve the efficiency of recognition and classification of blood cells,and ensure accuracy of the diagnosis of blood related diseases.

With redox-sensitive fluorescene probes DCFH-DA and DHR123, the formation of cytosolic and intramitochondrial reactive oxygen species (ROS) inside immature rat cerebellar granule cells during the apoptosis induced by nitric oxide donor S-nitroso-N-acetyl-pennicillamine (SNAP) was monitored by laser confocal scanning microscopy. The cytosolic and intramitochondrial ROS increase significantly after 0.5 mmol/L SNAP treatment for 1 h. Pre-treatment with the nitric oxide scavenger hemoglobin can effectively inhibit the formation of cytosolic and intrarnitochondrial ROS and protect neurons from apoptosis. Adding glutathione can also protect neurons from apoptosis, and the cytotoxity of nitric oxide increases significantly while the synthesis of glutathione is inhibited. The results indicated that ROS might be involved in NO-induced apoptosis in neural cells and glutathione might be the endogenesis antioxidant to protect neurons from oxidative injury.