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Myocardial fibrosis is an important manifestation of diabetic cardiomyopathy. This study investigated the potential mechanism of diabetic myocardial fibrosis. Male C57BL/6J and db/db mice aged 8 weeks were randomly divided into the diabetic (DB) and control groups. At 20 weeks, the mouse heart was harvested and subjected to hematoxylin-eosin staining (HE) and Masson staining to investigate the degree of fibrosis. The expressions of transforming growth factor-beta 1 (TGF-β1), collagen-III, B-cell lymphoma-2 (Bcl2), Bcl2-associated X protein (Bax), cleaved gasdermin D (GSDMD), cysteinyl aspartate specific proteinase-1 (caspase-1), apoptosis-associated speck-like protein containing a CARD (ASC), and nucleotide-binding oligomerization domain (NOD)-like receptor 3 (NLRP3) were measured by western blotting. Immunohistochemistry and TdT-mediated dUTP nick end labeling (TUNEL) staining were performed to analyze the development of apoptosis and pyroptosis. A significant increase in body weight and blood glucose in the DB group was observed. Myocardial pathological injury, fibrosis, apoptosis, and pyroptosis were more obvious and serious in the DB group. The expression of anti-apoptotic Bcl2 significantly decreased, while the expression levels of pro-apoptotic Bax, caspase-3, and pyroptosis-related proteins, such as cleaved GSDMD, and caspase-1 in the DB group were significantly increased. Pyroptosis and apoptosis were probably the main mechanisms that caused myocardial fibrosis in mice with diabetes. 相似文献
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The thermal decomposition of carbon tetrachloride on clean iron was studied in ultrahigh vacuum using molecular beam strategies,
where it is found that carbon tetrachloride thermally decomposes on the surface to deposit iron and carbon with exactly identical
kinetics as found at high pressures. No gas‐phase products are detected and the activation energy for the reaction (14.2 ±
0.5 kcal/mol) is in good agreement with the value measured at high pressures. Little carbon is detected on the surface using
Auger spectroscopy following reaction and it is found that this diffuses into the surface much faster when formed from CCl4 than from CH2Cl2. This effect is ascribed to the effect of co‐adsorbed chlorine on the adsorbed carbon, which is proposed to decrease the
activation energy for diffusion into the bulk of the sample. This effect explains the increased tendency for carbon tetrachloride
to form carbides under extreme‐pressure tribological conditions.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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Baicalin was determined in cosmetics and toothpaste by high-performance liquid chromatography. The samples were extracted with ultrasound in 75% ethanol for 20 min, purified by anion exchange solid-phase extraction cartridge, and the components were separated on a C18 column. The limits of detection and quantification were 3.0 mg kg?1 and 10.0 mg kg?1. The recovery was from 81.3–101.6%. A linear relationship was present from 1.00–100 µg · mL?1 of baicalin. The protocol was simple, sensitive, selective, and used to determine baicalin in personal care products. Baicalin was not present in materials contrary to the labeled contents. 相似文献
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Prolylcarboxypeptidase (PRCP) belongs to the S28 family of proteases, which is also a dipeptidyl peptidase.
In this study, we demonstrate the expression pattern of PRCP in Non-small cell lung cancer (NSCLC). We found that
the repression of PRCP expression by small interfering RNA successfully inhibited cell proliferation, migration, and
invasion. Further, we explored the involvement of PRCP in the regulation of epithelial-mesenchymal transition (EMT).
The epithelial marker E-cadherin was significantly increased, meanwhile mesenchymal markers MUC1, vimentin, and
SNAIL were markedly decreased in PRCP knockdown cells. Moreover, the downregulation of PRCP in the NSCLC
cells induced the expression of apoptosis-related proteins in vitro. We performed RT-PCR in 30 pairs of clinical NSCLC
tissues and adjacent non-cancerous tissues, which revealed significantly higher PRCP expression levels in cancer tissues
than in adjacent non-cancerous tissues. Collectively the results from our study suggest a possible cancer promotion role
of PRCP in NSCLC. 相似文献
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Dc molecular-beam methods are used to examine the reactivity of carbon tetrachloride with oxide films grown on iron in ultrahigh vacuum. The incident CCl4 beam flux is sufficiently low that the nature of the surface oxide is dictated by the annealing temperature allowing the reactivity of Fe2O3, Fe3O4 and FeO films to be examined. Carbon tetrachloride reacts rapidly with Fe2O3 and reaction with Fe3O4 commences at 620 K to evolve CO. The activation energy for this process is 20.6±1.0 kcal/mol. CCl4 reacts with FeO above 790 K, also to evolve CO, and the activation energy for this reaction is 5.7±0.4 kcal/mol. X-ray photoelectron spectroscopy shows the formation of a halide after reaction at 900 K. These results are in accord with film-growth kinetics measured using a microbalance at high pressures, where it was found that it was not necessary to remove the oxide layer prior to reaction. This contrasts with the behavior of sulfur-containing molecules, where the oxide layer had to be removed before a film would grow. This effect may contribute to the additive synergies commonly found in extreme-pressure lubricant additives where one of the roles of the chloride may be to reduce the oxide layer. 相似文献
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Quantitation of connective tissue versus parenchymal tissue compartments is important in assessment of fibrosis (scarring) and its progression in liver disease. This paper presents a two-step algorithm for quantifying fibrosis in liver biopsies stained with Sirius red. With this staining technique, collagen and cell nuclei appear similarly stained, whereas cytoplasm appears pale. The first step of the algorithm is to separate similarly stained areas occupied by collagen and hepatocyte nuclei. Since the total area of the combined collagen and cell nuclei is usually much smaller than the remaining liver parenchyma, a non-linear intensity mapping is applied to enhance the smaller cluster in order to match the larger one in both intensity and size. The second step is to differentiate the fibrotic areas usually having irregular shapes from hepatocyte nuclei that have relatively uniform size and have circular shape. The proposed algorithm has been applied to quantify the development of progressive fibrosis and its possible regression in liver biopsy specimens from patients with parenteral-induced liver injury undergoing intestinal transplantation. 相似文献
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The structure, properties and tribological behavior of DLC films are dependent on the deposition process, the hydrogen concentration and chemical bondings in the films. The present paper reports selected tribological experiments on model DLC films with different hydrogen contents. The experiments were performed in ultrahigh vacuum or in an atmosphere of pure hydrogen or argon in order to elucidate various friction mechanisms. Two typical friction regimes are identified. High steady-state friction in UHV (friction coefficient of 0.6) is observed for the lowest hydrogenated and mostly sp2-bonded DLC film. Superlow steady-state friction (friction coefficient in the millirange) is observed both for the highest hydrogenated film in UHV, and for the lowest hydrogenated film in an atmosphere of hydrogen (10 hPa). The high steady-state friction in UHV, observed for the lowest hydrogenated film with a dominant sp2 carbon hybridization, is associated with a –* sub-band overlap responsible for an increased across-the-plane chemical bonding with a high shear strength similar to what is observed with unintercalated graphite in the same UHV conditions. Superlow friction is correlated with a hydrogen saturation across the shearing plane through weak van der Waals interactions between the polymer-like hydrocarbon top layers. This regime is observed during the steady-state period if the film contains enough hydrogen incorporated during deposition. If this condition is not satisfied (i.e., for the film with the lowest hydrogen content), the limited diffusion of hydrogen from the film network towards the sliding surfaces seems to be responsible for a superlow running-in period. The superlow friction level can be reached over longer time periods by suitable combinations of temperature and molecular hydrogen present in the surrounding atmosphere during friction. 相似文献
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YONGDAE YOON SOONJAE HWANG FATEMA TUJ SAIMA MOON YOUNG KIM SOON KOO BAIK YOUNG WOO EOM 《Biocell》2023,47(3):669-676
Background: Activated hepatic stellate cells (HSCs) are closely involved in the initiation, perpetuation, and
resolution of liver fibrosis. Pro-inflammatory cytokine levels are positively correlated with the transition from liver
injury to fibrogenesis and contribute to HSC pathophysiology in liver fibrosis. Methods: In this study, we investigated
the effect of the pro-inflammatory cytokine interleukin (IL)-1β on the proliferation and signaling pathways involved
in fibrogenesis in LX-2 cells, an HSC cell line, using western blotting and cell proliferation assays. Results: IL-1β
increased the proliferation rate and α-smooth muscle actin (SMA) expression of LX-2 cells in a dose-dependent
manner. Within 1 h after IL-1β treatment, c-Jun N-terminal kinase (JNK), p38, and nuclear factor-κB (NF-κB)
signaling was activated in LX-2 cells. Subsequently, protein kinase B (AKT) phosphorylation and an increase in α-
SMA expression were observed in LX-2 cells. Each inhibitor of JNK, p38, or NF-κB decreased cell proliferation, AKT
phosphorylation, and α-SMA expression in IL-1β-treated LX-2 cells. Conclusion: These results indicate that JNK,
p38, and NF-κB signals converge at AKT phosphorylation, leading to LX-2 activation by IL-1β. Therefore, the AKT
signaling pathway can be used as a target for alleviating liver fibrosis by the inflammatory cytokine IL-1β. 相似文献
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A. Margreet De Leeuw Adriaan Brouwer Dick L. Knook 《Microscopy research and technique》1990,14(3):218-236
Liver endothelial cells form a continuous lining of the liver capillaries, or sinusoids, separating parenchymal cells and fat-storing cells from sinusoidal blood. Liver sinusoidal endothelial cells differ in fine structure from endothelial cells lining larger blood vessels and from other capillary endothelia in that they lack a distinct basement membrane and also contain open pores, or fenestrae, in the thin cytoplasmic projections which constitute the sinusoidal wall. This distinctive morphology supports the protective role played by liver endothelium, the cells forming a general barrier against pathogenic agents and serving as a selective sieve for substances passing from the blood to parenchymal and fat-storing cells, and vice versa. Sinusoidal endothelial cells, furthermore, significantly participate in the metabolic and clearance functions of the liver. They have been shown to be involved in the endocytosis and metabolism of a wide range of macromolecules, including glycoproteins, lipoproteins, extracellular matrix components, and inert colloids, establishing endothelial cells as a vital link in the complex network of cellular interactions and cooperation in the liver. Fine structural studies in combination with the development of cell isolation and culture techniques from both experimental animal and human liver have greatly contributed to the elucidation of these endothelial cell functions. Morphological and biochemical investigations have both revealed little changes with age except for an accumulation of iron ferritin and a decrease in the activities of glucose-6-phosphatase, Mg-ATPase, and in glucagon-stimulated adenylcyclase. Future studies are likely to disclose more fully the role of sinusoidal endothelial cells in the regulation of liver hemodynamics, in liver metabolism and blood clearance, in the maintenance of hepatic structure, in the pathogenesis of various liver diseases, and in the aging process in the liver. 相似文献
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RAFAEL SCAF DE MOLON MARTA MARIA ALVES PEREIRA ERICA DORIGATTI DE AVILA 《Biocell》2022,46(5):1151-1156
It has been recognized that physical and chemical properties of biomaterial surfaces mediate the quality of extracellular matrix (ECM) that may affect cell behaviors. In nature, ECM is a heterogeneous three-dimensional superstructure formed by three major components, glycosaminoglycan, glycoconjugate, and protein, that anchors cellular compartments in tissues and regulates the function and the behavior of cells. Changes in the biointerface alter the quality of ECM and morphology through cell surface receptors, which, in turn, enable it to trigger specific cell signaling and different cellular responses. In fact, a number of strategies have been used to improve the functionality of surfaces and direct cell behavior through precisely designed environments. Herein, we aimed to discuss, through a science-based viewpoint, the biomaterial surface features on cell behavior and analyze the impact of cell physical modification on dental implant development. 相似文献
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Donnet C. Mogne T. Le Ponsonnet L. Belin M. Grill A. Patel V. Jahnes C. 《Tribology Letters》1998,4(3-4):259-265
The tribological behavior of diamond-like carbon coatings (DLC) strongly depends on the chemical nature of the test environment.
The present study proposes to explore the influence of water vapor and oxygen on the friction behavior of a hydrogenated DLC
coating exhibiting ultralow friction in ultrahigh vacuum (friction coefficient below 0.01). Using a UHV tribometer, reciprocating
pin-on-flat friction tests were performed in progressively increasing or decreasing partial pressures of pure oxygen and pure
water vapor. The maximum gaseous pressures of oxygen and water vapor were 60 hPa and 25 hPa (1 hPa = 100 Pa), respectively,
the second value corresponding to a relative humidity (RH) of 100% at room temperature. It was found that, for the pressure
range explored, oxygen does not change the ultralow friction behavior of DLC observed in UHV. Conversely, water vapor drastically
changes the friction coefficient at pressures above 0.5 hPa (RH = 2%), from about 0.01 to more than 0.1. Electron energy loss
spectroscopy and in situ Auger electron spectroscopy have been performed to elucidate the friction mechanisms responsible
for the tribological behaviors observed with the two different gaseous environments. In all cases no significant oxidation
has been observed either inside the wear scars or in the wear debris particles. Ultralow friction is systematically associated
with a homogeneous carbon-based transfer film. The higher friction observed at partial pressure of water vapor higher than
0.5 hPa, is associated with a thinner transfer film. Consequently friction seems to be controlled by the transfer film whose
kinetics of formation strongly depends on the partial pressure of water vapor.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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An analysis was made of the residual stresses induced during sliding contact of a series of Cu-Al alloys of various stacking fault energies (SFEs) using the conventional two-exposure X-ray technique. Compressive residual stresses were found in all alloys which increased with decreasing SFE in a manner analogous to the strain-hardening behavior. The macroscopic wear rate was found to be linearly related to the compressive stresses induced during the wear process. The increase in wear rate associated with increasing hardness and residual compressive stresses is attributed to the presence of a residual tensile stress normal to the surface. 相似文献
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Kinetics of laser induced desorption and decomposition of Fomblin Zdol on carbon overcoats 总被引:1,自引:0,他引:1
Heat assisted magnetic recording (HAMR) on magnetic hard disks is being explored as a means of increasing the areal density of stored data beyond the limits of current technologies. HAMR will subject the magnetic media, the overcoat, and the lubricant on its surface to temperatures in the range 400–650 °C for periods of a few nanoseconds per pass of the read-write head. During such rapid heating events the lubricant is prone to decomposition and desorption from the surface, either of which lead to degradation of the lubricant film, jeopardizing the integrity of the stored data. Rapid laser annealing is known to bias the reactions of small molecules adsorbed on surfaces to favor desorption over decomposition. Analysis of the desorption and decomposition kinetics of perfluoropolyalkylether lubricants such as Fomblin Zdol shows that rapid heating to high temperatures favors desorption over decomposition for molecules with molecular weights of less than 3000. For higher molecular weight Fomblins decomposition is favored at the temperatures to be used for HAMR. 相似文献
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A few monolayers of a carbon film on an Si(111) substrate have been studied for tribological characteristics, focusing on the tribological role of the surface atoms.A monolayer of H and Ag on Si were also tested with a macroscopic diamond slider to examine the effect of the surface atoms on the friction, and it was observed that the sliding systems show an extraordinarily low friction in ultra-high vacuum. We could draw a conclusion: the chemical characteristics of the surface layer strongly affect the friction and nano-scale structures on the surface drastically change the macroscopic slider friction in these systems. 相似文献
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The role of induced contrast in images obtained using the environmental scanning electron microscope
Generation of contrast in images obtained using the environmental scanning electron microscope (ESEM) is explained by interpretation of images acquired using the gaseous secondary electron detector (GSED), ion current, and the Everhart-Thornley detector. We present a previously unreported contrast component in GSED and ion current images attributed to signal induction by changes in the concentration of positive ions in the ESEM chamber during image acquisition. Changes in positive ion concentration are caused by changes in electron emission from the sample during image acquisition and by a discrepancy between the drift velocities of negative and positive charge carriers in the imaging gas. The proposed signal generation mechanism is used to explain contrast reversal in images produced using the GSED and ion current signals and accounts for discrepancies in contrast observed, under some conditions, in these types of images. Combined with existing models of signal generation in the ESEM, the proposed model provides a basis for correct interpretation of ESEM images. 相似文献