Effect of interrupted aging on mechanical properties and corrosion resistance of 7A75 aluminum alloy

The effects of interrupted aging on mechanical properties and corrosion resistance of 7A75 aluminum alloy extruded bar were investigated through various analyses,including electrical conductivity,mechanical properties,local corrosion properties,and slow strain rate tensile stress corrosion tests.Microstructure characterization techniques such as metallographic microscopy,scanning electron microscopy(SEM),and transmission electron microscopy(TEM)were also employed.The results indicate that the tensile strength of the alloy produced by T6I6 aging is similar to that produced by T6I4 aging,and it even exceeds 700 MPa.Furthermore,the yield strength increases by 52.7 MPa,reaching 654.8 MPa after T6I6 aging treatment.The maximum depths of intergranular corrosion(IGC)and exfoliation corrosion(EXCO)decrease from 116.3 and 468.5μm to 89.5 and 324.3μm,respectively.The stress corrosion factor also decreases from 2.1%to 1.6%.These findings suggest that the alloy treated with T6I6 aging exhibits both high strength and excellent stress corrosion cracking resistance.Similarly,when the alloy is treated with T6I4,T6I6 and T6I7 aging,the sizes of grain boundary precipitates(GBPs)are found to be 5.2,18.4,and 32.8 nm,respectively.The sizes of matrix precipitates are 4.8,5.7 and 15.7 nm,respectively.The atomic fractions of Zn in GBPs are 9.92 at.%,8.23 at.%and 6.87 at.%,respectively,while the atomic fractions of Mg are 12.66 at.%,8.43 at.%and 7.00 at.%,respectively.Additionally,the atomic fractions of Cu are 1.83 at.%,2.47 at.%and 3.41 at.%,respectively.

Interleukin-22 ameliorates liver fibrogenesis by attenuating hepatic stellate cell activation and downregulating the levels of inflammatory cytokines

AIM:To investigate the effect of interleukin(IL)-22 onhepatic fibrosis in mice and the possible mechanism involved.METHODS:Liver fibrosis was induced in male BALB/c mice by CCl4.Recombinant IL-22(rm IL-22) was administered intraperitoneally in CCl4-treated mice.Fibrosis was assessed by histology and Masson staining.The activation of hepatic stellate cells(HSCs) was investigated by analysis of α-smooth muscle actin expression.The frequencies of T helper(Th) 22 cells,Th17 cells and Th1 cells,the expression of inflammatory cytokines [IL-22,IL-17 A,interferon-γ(IFN-γ),tumor necrosis factor-α(TNF-α),IL-6,IL-1b] and transcription factors [aryl hydrocarbon receptor(AHR),RAR-related orphan receptor(RORγt),T-bet] m RNA in the liver were investigated.In addition,the plasma levels of IL-22,IL-17 A,IFN-γ,TNF-α,IL-6 and IL-1b were evaluated.RESULTS:Significant elevations in circulating Th22 cells,Th17 cells,Th1 cells,IL-22,IL-17 A,and IFN-γ were observed in the hepatic fibrosis group compared with the control group(P < 0.01).Treatment with rm IL-22 in mice with hepatic fibrosis ameliorated the severity of hepatic fibrosis,which was confirmed by lower hepatic fibrosis pathological scores(P < 0.01).Rm IL-22 decreased the frequencies of Th22 cells(6.71% ± 0.97% vs 8.09% ± 0.74%,P < 0.01),Th17 cells(4.34% ± 0.37% vs 5.71% ± 0.24%,P < 0.01),Th1 cells(3.09% ± 0.49% vs 4.91% ± 0.73%,P < 0.01),and the levels of IL-22(56.23 ± 3.08 vs 70.29 ± 3.01,P < 0.01),IL-17A(30.74 ± 2.77 vs 45.68 ± 2.71,P < 0.01),and IFN-γ(74.78 ± 2.61 vs 124.89 ± 2.82,P < 0.01).Down-regulation of IL-22,IL-17 A,IFN-γ,TNF-α,IL-6,IL-1b,AHR RORγt,and T-bet gene expression in the liver was observed in the rm IL-22 group(P < 0.01).CONCLUSION:The frequencies of Th22,Th17 andTh1 cells are elevated in hepatic fibrosis.Rm IL-22 can attenuate HSC activation and down-regulate the levels of inflammatory cytokines,thereby ameliorating liver fibrogenesis.

Role and recruitment of Th9 cells in liver cirrhosis patients

Objective:To investigate the role of T helper 9(Th9) cells in liver cirrhosis(LC) patients and whether chemokine receptor type 6(CCR6)/chemokine ligand 20(CCL20) axis is involving in the recruitment of Th9 cells into liver.Methods:Peripheral blood and liver tissue from 30 LC patients and 18 normal controls were recruited.The frequency of Th9 cells and CCR4,CCR6 in the peripheral blood was tested by flow cytometry.Serum interleukin(IL)-9 and CCL20 levels were tested by enzyme-linked immunosorbent assay.Immunohistochemical staining was used to detect a-smooth muscle actin,CCR6 and CCL20 expression in liver tissue.Results:The frequency of Th9 cells in LC patients was significantly increased compared with controls(P < 0.05).The serum IL-9 level and CCL20 level increased markedly in LC patients compared with controls(P < 0.05),and IL-9 was positively correlated to Th9 cells and CCL20.Furthermore,the frequency of Th9 cells was correlated to prothrombin time,total bilirubin level,hyaluronic acid and type IV collagen in LC patients.We also found that Th9 cells in LC patients expressed higher frequency of CCR4+,CCR6+(P < 0.05).Compared with normal controls,the expression of CCR6 and CCL20 in LC tissue were significantly elevated(P < 0.05).The expression of a-smooth muscle actin was correlated to the CCR6 and CCL20 in liver tissue of LC patients.Conclusions:This study suggests that Th9 cells may participate in the pathogenesis of LC,and the recruitment of Th9 cells into liver tissue might be through CCL20/CCR6 axis.

Role of Th9 cells and Th17 cells in the pathogenesis of malignant ascites

Objective: To assess the role of Th9 and Th17 cells in malignant ascites(MA).Methods: MA from 30 hepatic carcinoma patients and benign ascites from 30 cirrhotic patients were collected. Corresponding peripheral blood samples from these hepatic carcinoma and cirrhotic patients as well as 30 healthy subjects were collected. The frequency of Th9 and Th17 cells was tested by flow cytometry. Serum levels of interleukin(IL)-9 and IL-17 were examined by ELISA.Results: The observed frequency of Th9 and Th17 cells, and the IL-9 and IL-17 serum levels were significantly higher in MA patients than those in cirrhotic patients and healthy control samples(P < 0.05). Moreover, the Th9 cells demonstrated positive correlation with Th17 cells as well as IL-9 in MA patients; however, this positive correlation was not observed in the cirrhotic patients or healthy control samples. The frequency of Th9 and Th17 cells was distinctly higher in MA patients presenting with stage III or IV malignancy and with lymph node or distant metastasis than those in patients in stage I or II and without distant metastasis(P < 0.05).Conclusions: The increased frequency of Th9 and Th17 cells in MA patients suggests that these two T cell subsets play a synergistic role in MA pathogenesis. This study also demonstrated that Th9 and Th17 cells may perform their biological functions in conjunction with IL-9 production.

neo-Clerodane diterpenoids from Salvia dugesii and their bioactive studies

Salvia dugesii is an invasive plant in Yunnan,China.To tentatively explore its utilization,a systematic phytochemical investigation was carried out on this plant,which led to the isolation of five new neo-clerodane diterpenoids,dugesins C-G(1-5),together with six known ones.Their structures were determined by comprehensive NMR and MS spectroscopic analysis.It was noteworthy that the eleven isolates,composed of five different carbocyclic systems derived from the neo-clerodane diterpenoid skeleton,were reported from the same plant for the first time.The anti-feedantial,cytotoxic,and antiviral activities of the isolates were evaluated.Dugesin F(4)was tested to be a non-toxic antiviral compound against influenza virus FM1.

Meroterpenthiazole A, a unique meroterpenoid from the deep-sea-derived Penicillium allii-sativi, significantly inhibited retinoid X receptor (RXR)-α transcriptional effect

A novel meroterpenoid,named meroterpenthiazole A(1),was isolated from the deep-sea-derived Penicillium allii-sativi.Its structure was established by extensive spectroscopic and computational methods.Meroterpenthiazole A bears a rare benzothiazole moiety in nature.Compound 1 significantly inhibited retinoid X receptor(RXR)-α transcriptional effect(K_(D)=12.3 μmol/L) through a novel binding mechanism.