Search results for "Adhesion"

Methods of controllable internal rupture in solids and liquids for obtaining atomically-clean surfaces and investigating their adhesion

1995

Controllable internal rupture (CIR) methods for obtaining atomically-clean solid surfaces and closed ultrahigh vacuum (UHV) space are described. A number of modifications of CIR methods have been developed. Their performance, characteristics and applications for investigation of adhesion are considered. CIR methods are based on the creation of virgin atomically-clean rupture surfaces in the bulk of solids during deformation of specially manufactured heterogeneous systems. For all modifications of the method, the samples have been manufactured in the form of vacuum-tight capsules and the investigation procedure has been carried out in atmospheric conditions. CIR methods, in addition to well-…

Polycaprolactone/gelatin-based scaffolds with tailored performance: in vitro and in vivo validation

2019

Abstract Nanofibrous scaffolds composed of polycaprolactone (PCL) and gelatin (Ge) were obtained through a hydrolytic assisted electrospinning process. The PCL-to-Ge proportion (100/0 to 20/80), as well as the dissolution time (24, 48, 72, 96, 120 h) into a 1:1 formic/acetic acid solvent before electrospinning were modified to obtain the different samples. A strong influence of these factors on the physicochemical properties of the scaffolds was observed. Higher Ge percentage reduced crystallinity, allowed a uniform morphology and increased water contact angle. The increase in the dissolution time considerably reduced the molar mass and, subsequently, fibre diameter and crystallinity were a…

Aluminum oxide from trimethylaluminum and water by atomic layer deposition:The temperature dependence of residual stress, elastic modulus, hardness a…

2014

Use of atomic layer deposition (ALD) in microelectromechanical systems (MEMS) has increased as ALD enables conformal growth on 3-dimensional structures at relatively low temperatures. For MEMS device design and fabrication, the understanding of stress and mechanical properties such as elastic modulus, hardness and adhesion of thin film is crucial. In this work a comprehensive characterization of the stress, elastic modulus, hardness and adhesion of ALD aluminum oxide (Al2O3) films grown at 110-300 C from trimethylaluminum and water is presented. Film stress was analyzed by wafer curvature measurements, elastic modulus by nanoindentation and surface-acoustic wave measurements, hardness by na…

Mechanical and cohesion properties of brass plated steel cords in a sulphurizing environment

1986

The mechanical and cohesion properties of brass plated steel cords have been investigated in dry hydrogen sulphide between 25 and 450° C. The extents of elastic and plastic regions, obtained from slow strain rate technique data have been defined, and the preferential site of decohesion tends to be the brass-steel interface.

PSA-NCAM immunocytochemistry in the cerebral cortex and other telencephalic areas of the lizard Podarcis hispanica: differential expression during me…

2002

The lizard medial cortex, a region homologous to the mammalian dentate gyrus, shows postnatal neurogenesis and the surprising ability to replace its neurons after being lesioned specifically with the neurotoxin 3-acetylpyridine. As the polysialylated form of the neural cell adhesion molecule (PSA-NCAM) is expressed during neuronal migration and differentiation, we have studied its distribution in adult lizards and also during the lesion-regeneration process. In the medial cortex of control animals, many labeled fusiform somata, presumably corresponding to migratory neuroblasts, appeared in the inner plexiform layer. There were also scattered immunoreactive granule neurons in the cell layer.…

New Imidazo[2,1-b][1,3,4]Thiadiazole Derivatives Inhibit FAK Phosphorylation and Potentiate the Antiproliferative Effects of Gemcitabine Through Modu…

2020

Background/aim A new class of imidazo[2,1-b][1,3,4]thiadiazole compounds have recently been evaluated as inhibitors of phosphorylation of focal adhesion kinase (FAK) in pancreatic cancer. FAK is overexpressed in mesothelioma and has recently emerged as an interesting target for the treatment of this disease. Materials and methods Ten imidazo[2,1-b][1,3,4]thiadiazole compounds characterized by indole bicycle and a thiophene ring, were evaluated for their cytotoxic activity in two primary cell cultures of peritoneal mesothelioma, MesoII and STO cells. Results Compounds 1a and 1b showed promising antitumor activity with IC50 values in the range of 0.59 to 2.81 μM in both cell lines growing as …

MT5-MMP regulates adult neural stem cell functional quiescence through the cleavage of N-cadherin.

2014

The identification of mechanisms that maintain stem cell niche architecture and homeostasis is fundamental to our understanding of tissue renewal and repair. Cell adhesion is a well-characterized mechanism for developmental morphogenetic processes, but its contribution to the dynamic regulation of adult mammalian stem cell niches is still poorly defined. We show that N-cadherin-mediated anchorage of neural stem cells (NSCs) to ependymocytes in the adult murine subependymal zone modulates their quiescence. We further identify MT5-MMP as a membrane-type metalloproteinase responsible for the shedding of the N-cadherin ectodomain in this niche. MT5-MMP is co-expressed with N-cadherin in adult N…

Morphological changes in adherent cells induced by Clostridium difficile toxins.

1991

Correlation of renal tubular epithelial cell-derived interleukin-18 up-regulation with disease activity in MRL-Faslpr mice with autoimmune lupus neph…

2002

Objective MRL-Faslpr mice spontaneously develop an autoimmune disease that mimics systemic lupus erythematosus in humans. Infiltrating T cells expressing interferon-γ (IFNγ) are responsible for the autoimmune kidney destruction in MRL-Faslpr mice, and interleukin-18 (IL-18) released by mononuclear phagocytes stimulates T cells to produce the IFNγ. Since MRL-Faslpr T cells are characterized by an overexpression of the IL-18 receptor accessory chain, we sought to determine the impact of IL-18 on the progression of lupus nephritis in MRL-Faslpr mice. Methods IL-18 expression in sera and kidney tissues from MRL-Faslpr mice was determined by enzyme-linked immunosorbent assay (ELISA), reverse tra…

Anti-adhesion agents against Gram-positive pathogens

2014

The rise of antibiotic-resistance as well as the deficiency of investments by pharmaceutical companies in the development of new antibiotics, have stimulated the investigation of alternative strategies to conventional antibiotics for counteracting the pathogens. A fundamental step of Gram positive pathogenesis is the bacterial adhesion to the host tissue involving a direct and a specific interaction between bacterial surface molecules and host ligands. Targeting the adhesion is a good strategy to design novel anti-infective drugs agents useful to interfere with the pathogenic process and with a virulence mechanism as biofilm formation. This review is focused on anti-virulence compounds whic…