PTCH1+/− Dermal Fibroblasts Isolated from Healthy Skin of Gorlin Syndrome Patients Exhibit Features of Carcinoma Associated Fibroblasts

Gorlin's or nevoid basal cell carcinoma syndrome (NBCCS) causes predisposition to basal cell carcinoma (BCC), the commonest cancer in adult human. Mutations in the tumor suppressor gene PTCH1 are responsible for this autosomal dominant syndrome. In NBCCS patients, as in the general population, ultraviolet exposure is a major risk factor for BCC development. However these patients also develop BCCs in sun-protected areas of the skin, suggesting the existence of other mechanisms for BCC predisposition in NBCCS patients. As increasing evidence supports the idea that the stroma influences carcinoma development, we hypothesized that NBCCS fibroblasts could facilitate BCC occurence of the patients. WT (n = 3) and NBCCS fibroblasts bearing either nonsense (n = 3) or missense (n = 3) PTCH1 mutations were cultured in dermal equivalents made of a collagen matrix and their transcriptomes were compared by whole genome microarray analyses. Strikingly, NBCCS fibroblasts over-expressed mRNAs encoding pro-tumoral factors such as Matrix Metalloproteinases 1 and 3 and tenascin C. They also over-expressed mRNA of pro-proliferative diffusible factors such as fibroblast growth factor 7 and the stromal cell-derived factor 1 alpha, known for its expression in carcinoma associated fibroblasts. These data indicate that the PTCH1+/− genotype of healthy NBCCS fibroblasts results in phenotypic traits highly reminiscent of those of BCC associated fibroblasts, a clue to the yet mysterious proneness to non photo-exposed BCCs in NBCCS patients

Effect of Surface Treatment on Corrosion Resistance of 304 Stainless Steel Implants in Tyrode Solution

The effect of different surface preparation methods such as mechanical, chemical and electrochemical surface preparation on the formation, stability and deterioration of surface films formed on austenitic 304 stainless steel was investigated in Tyrode’s physiological solution by cyclic polarization curves, AC impedance measurements surface techniques. A hysteresis loop in a cyclic polarization curve was obtained that indicates a delay in repassivation of an existing pit when the potential is scanned cathodically. Electrolytic polishing and ultrasonic cleaning improves corrosion resistance by increasing the value of the corrosion potential and breakdown potential of the passive layer as well as the pit initiation potential. After mechanical polishing no perfect passivation region was observed. Change in surface fractal is in good agreement with the result obtained from height roughness factor of AFM.Wpływ różnych sposobów przygotowania powierzchni, takich jak mechaniczne, chemiczne i elektrochemiczne na tworze-nie, stabilność i degradację warstw powierzchniowych utworzonych na austenitycznej stali nierdzewnej 304. badano w fizjologicznym płynie Ty rode'a technikami badań powierzchni - cyklicznych krzywych polaryzacyjnych oraz impedancji. Uzyskano pętlę histerezy cyklicznej krzywej polaryzacyjnej, co wskazuje na opóźnienie w repasywacji istniejących wżerów podczas skanowania potencjału w kierunku katodowym. Elektrolityczne polerowanie i czyszczenie ultradźwiękowe poprawia odporność korozyjną poprzez zwiększenie potencjału korozyjnego i potencjału przebicia warstwy pasywnej, jak również potencjału tworzenia się wżerów. Zmiana fraktala powierzchni jest w dobrej zgodności z wynikami uzyskanymi dla wysokościowych współczynników chropowatości z pomiarów AFM

Wpływ obróbki powierzchniowej na odporność na korozję implantów ze stali nierdzewnej 304 w płynie Tyrode’a

The effect of different surface preparation methods such as mechanical, chemical and electrochemical surface preparation on the formation, stability and deterioration of surface films formed on austenitic 304 stainless steel was investigated in Tyrode’s physiological solution by cyclic polarization curves, AC impedance measurements surface techniques. A hysteresis loop in a cyclic polarization curve was obtained that indicates a delay in repassivation of an existing pit when the potential is scanned cathodically. Electrolytic polishing and ultrasonic cleaning improves corrosion resistance by increasing the value of the corrosion potential and breakdown potential of the passive layer as well as the pit initiation potential. After mechanical polishing no perfect passivation region was observed. Change in surface fractal is in good agreement with the result obtained from height roughness factor of AFM.Wpływ różnych sposobów przygotowania powierzchni, takich jak mechaniczne, chemiczne i elektrochemiczne na tworze-nie, stabilność i degradację warstw powierzchniowych utworzonych na austenitycznej stali nierdzewnej 304. badano w fizjologicznym płynie Ty rode'a technikami badań powierzchni - cyklicznych krzywych polaryzacyjnych oraz impedancji. Uzyskano pętlę histerezy cyklicznej krzywej polaryzacyjnej, co wskazuje na opóźnienie w repasywacji istniejących wżerów podczas skanowania potencjału w kierunku katodowym. Elektrolityczne polerowanie i czyszczenie ultradźwiękowe poprawia odporność korozyjną poprzez zwiększenie potencjału korozyjnego i potencjału przebicia warstwy pasywnej, jak również potencjału tworzenia się wżerów. Zmiana fraktala powierzchni jest w dobrej zgodności z wynikami uzyskanymi dla wysokościowych współczynników chropowatości z pomiarów AFM

Adsorption and corrosion inhibition behaviour of acid red on AISI 4130 alloy steel in HCl solution

345-352The inhibition behaviour of 2-(N,N-Dimethyl-4-aminophenyl)azobenzenecarboxylic acid (acid red) on the corrosion resistance of AISI 4130 steel in 1 M HCl solution has been studied by potentiodynamic polarization (Tafel), electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). Polarization studies indicate that the inhibition efficiency increases with the increase in inhibitor concentration and inhibitor retard both the cathodic and anodic reactions so classified as mixed type inhibitors. EIS data has been analyzed to equivalent circuit model and show that as the inhibitor concentration increased the charge transfer resistance of steel increased whilst double layer capacitance decreased. The effect of temperature on the corrosion behavior of steel in HCl with the addition of the inhibitor was studied in the temperature range from 25-65°C. The experimentally obtained adsorption isotherms follow the Langmuir equation. Activation parameters and thermodynamic adsorption parameters of the corrosion process such as Ea, ΔH, ΔS, Kads and ΔG°ads are calculated at different temperatures and using the adsorption isotherm. The morphology of steel surface after its exposure to HCl solution in the absence and presence of inhibitor has been examined by SEM images

The effect of organosilane on corrosion resistance of epoxy coating containing cerium nitrate

Published online: 12 Aug 2013Structure and corrosion resistance behavior of epoxy coating containing cerium nitrate in different amounts of γ-glycidoxypropyltrimethoxysilane (γ-GPS) were investigated. Corrosion resistance ability of coating systems was characterized by using electrochemical impedance spectroscopy and polarization techniques. Also atomic force microscopy was used to evaluate dispersion of cerium nitrate in the presence of γ-GPS. Furthermore, the effect of γ-GPS on flexibility of coatings was studied by using the cupping test. Increment of 10 wt.% of γ-GPS into the coating formulation led to the superior dispersion of cerium nitrate and also highest corrosion protection performance.Sadeq Hooshmand Zaferania, Davood Zaareib, Iman Danaeea and Nazgol Mehrabian