29 research outputs found

    Effects of Process Parameters and CrCl3 Concentration on the Structure, Surface Morphology, Composition and Corrosion Resistance of Electrodeposited NiCrP Amorphous Alloy Coatings

    No full text
    Herein, NiCrP amorphous alloy coatings were prepared on copper substrates by electrodeposition. The aim of this paper is to replace Cr6+ with Cr3+ to prepare NiCrP amorphous alloy coating, which can reduce environmental pollution. By studying the influence of pH, temperature (T), current density (DK), and CrCl3 concentration on the structure, surface morphology, composition, and corrosion resistance of the alloy coatings, the optimum bath formulation and process parameters were determined as follows: 25 g·L−1 NiSO4·6H2O, 100 g·L−1 CrCl3·6H2O, 20 g·L−1 NaH2PO2·H2O, 80 g·L−1 Na3C6H5O7·2H2O (sodium citrate), 40 g·L−1 H3BO3, 50 g·L−1 NH4Cl, 1 g·L−1 KF, 5 g·L−1 C7H5O3NS (saccharin), 0.05 g·L−1 C12H25SO4Na (sodium dodecyl sulfate), and 40 mL·L−1 HCOOH and T: 30 °C, DK: 15 A·dm−2, and pH: 3.5, respectively. NiCrP amorphous alloy coatings with high corrosion resistance were prepared under the abovementioned conditions. The crystal cells of the coating surface are uniform and fine. The corrosion resistance of the NiCrP amorphous alloy coatings was characterized by polarization curves, electrochemical impedance spectroscopy, and an immersion corrosion test and compared with that of the NiP amorphous alloy coating. The results show that Ni91.9P8.1 and Ni83.5Cr8.3P8.2 corrosion potential and corrosion current density are −0.68, −0.44 V, and 36, 7 μA·cm−2 in 3.5 wt.% NaCl, respectively. With Ni91.9P8.1 and Ni83.5Cr8.3P8.2, the maximum weight loss is 61.67 and 15.42 mg·dm−2 in a 1 mol·L−1 HCl, respectively. The corrosion resistance of the NiCrP amorphous alloy coatings in 3.5 wt.% NaCl and 1 mol·L−1 HCl solutions is better than that of the NiP alloy coating

    Analyses of artificial morel soil bacterial community structure and mineral element contents in ascocarp and the cultivated soil

    No full text
    This study explored the differences among different artificial morel cultivations and the influential factors, including soil bacterial community structure, yield, and mineral element contents of ascocarp and the cultivated soil. High-throughput sequencing results revealed that the dominant bacterial phyla in all the samples, including Proteobacteria, Acidobacteria, Chloroflexi, Bacteroides and Gemmatimonadetes, were found not only in morel soils (experimental group) but also in wheat soil (control group), while the highest richness and diversity in the soil bacteria were observed during the primordial differentiation stage. M6 group exhibited the highest yield (271.8g/m2) and had an unexpectedly high proportion of Pseudomonas (25.30%) during the primordial differentiation stage, which was 1.77ď˝ 194.62 times more than the proportion of Pseudomonas in other samples. Pseudomonas may influence the growth of morel. Mineral element contents of the varied soil groups and ascocarp were determined using electro thermal digestion and inductively coupled plasma mass spectrometry. The results revealed that morel had high enrichment effects on Phosphorus (P, Bioconcentration factor = 16.83), Potassium (K, 2.18), Boron (B, 1.47), Zinc (Zn, 1.36), Copper (Cu, 1.15) and Selenium (Se, 2.27). P levels were the highest followed by Se and K, and the mineral element contents in ascocarp were positively correlated with the soil element contents.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

    Medicarpin suppresses lung cancer cell growth in vitro and in vivo by inducing cell apoptosis

    Get PDF
    Lung cancer (LC) is the leading cause of cancer deaths worldwide. Surgery, chemoradiotherapy, targeted therapy, and immunotherapy are considered dominant treatment strategies for LC in the clinic. However, drug resistance and metastasis are two major challenges in cancer therapies. Medicarpin (MED) is an isoflavone compound isolated from alfalfa, which is usually used in traditional medicine. This study was designed to evaluate the anti-LC effect and reveal the underlying mechanisms of MED in vivo and in vitro. We found that MED could significantly inhibit proliferation, induce apoptosis, and cell cycle arrest of A549 and H157 cell lines. Basically, MED induced cell apoptosis of LC cells by upregulating the expression of pro-apoptotic proteins BAX and Bak1, leading to the cleavage of caspase-3 (Casp3). Moreover, MED inhibited the proliferation of LC cells via downregulating the expression of proliferative protein Bid. Overall, MED inhibited LC cell growth in vitro and in vivo via suppressing cell proliferation and inducing cell apoptosis, suggesting the therapeutic potential of MED in treating LC

    G‑Quadruplex Structures as a “Switch” Regulate ATF4 Expression in Ferroptotic HepG2 Cells

    No full text
    G-quadruplex (G4) is a noncanonical structure folded in a widespread manner by guanine-rich tandem repeated sequences. As a key response factor, activating transcription factor 4 (ATF4) has dual functions in managing iron-dependent ferroptosis by regulating amino acid synthesis and antioxidant-related gene expression. In our study, the activity of ATF4 expression was elevated in HepG2 cells induced by erastin. Based on preliminary bioinformatics analyses, the G-tract region, named WT, had high potential to form G4, and it was found that PDS could markedly weaken the increase of ATF4 expression by reducing the sensitivity of HepG2 cells toward erastin. In circular dichroism spectra, WT oligonucleotides showed characteristic molar ellipticity at specific wavelengths of parallel G4 structures, while corresponding single-base mutants possessed a weaker ability to form G4, which were consistent with immunostaining results. In addition, endogenous G4 formed by the WT motif was significantly destroyed in HepG2 cells treated with erastin. After being transfected with WT oligonucleotides, the levels of ATF4 mRNA decreased significantly regardless of being treated with erastin or not. Meanwhile, mutations of G-tracts could advantageously impact the luciferase expression downstream of an ATF4 promoter in reporter assays, manifesting that the decrease of endogenous G4 in the ATF4 promoter was positively associated with the expression enhanced by erastin in HepG2 cells

    Impaired phagocytosis of apoptotic cells causes accumulation of bone marrow-derived macrophages in aged mice

    No full text
    Accumulation of tissue macrophages is a significant characteristic of disease-associated chronic inflammation, and facilitates the progression of disease pathology. However, the functional roles of these bone marrow-derived macrophages (BMDMs) in aging are unclear. Here, we identified agedependent macrophage accumulation in the bone marrow,showing that aging significantly increases the number of M1 macrophages and impairs polarization of BMDMs. We found that age-related dysregulation of BMDMs is associated with abnormal overexpression of the anti-inflammatory interleukin-10.BMDM dysregulation in aging impairs the expression levels of pro-inflammatory cytokines and genes involved in B-cell maturation and activation. Phagocytosis of apoptotic Jurkat cells by BMDMs was reduced because of low expression of phagocytic receptor CD14, indicating that increased apoptotic cells may result from defective phagocytosis of apoptotic cells in the BM of aged mice. Therefore, CD14 may represent a promising target for preventing BMDM dysregulation, and macrophage accumulation may provide diagnostic and therapeutic clues. © 2017 by the The Korean Society for Biochemistry and Molecular Biology.1

    Upregulation of SIRT1 by Kartogenin Enhances Antioxidant Functions and Promotes Osteogenesis in Human Mesenchymal Stem Cells

    No full text
    Osteoarthritis is a chronic degenerative joint disease involving both articular cartilage and subchondral bone. Kartogenin (KGN) was recently identified to improve in vivo cartilage repair; however, its effect on bone formation is unknown. The aim of this study was to investigate the effect of KGN on antioxidant properties and osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BM-MSCs). Human BM-MSCs were treated with KGN at concentrations ranging from 10−8 M to 10−6 M. Our results indicated that KGN improved cell proliferation and attenuated intracellular reactive oxygen species. The levels of antioxidant enzymes and osteogenic differentiation of BM-MSCs were enhanced by KGN in a dose-dependent manner. Furthermore, KGN-treated BM-MSCs showed upregulation of silent information regulator type 1 (SIRT1) and increased phosphorylation of adenosine 5′-monophosphate-activated protein kinase (AMPK), indicating that KGN activated the AMPK-SIRT1 signaling pathway in BM-MSCs. Inhibition of SIRT1 by nicotinamide reversed the antioxidant effect of KGN on BM-MSCs and suppressed osteogenic differentiation. In conclusion, our results demonstrated that KGN improved intracellular antioxidant properties and promoted osteogenic differentiation of BM-MSCs by activating the AMPK-SIRT1 signaling pathway. Thus, KGN may have the potential for not only articular cartilage repair but also the clinical application of MSCs in bone tissue engineering
    corecore