Sliding wear of a-C:H coatings against alumina in corrosive media

This paper reports the results obtained from the study of friction and sliding wear in two corrosive solutions of an a-C:H coating deposited on 316L stainless against an alumina ball, employed as static counter part. Calculations of the values of the von Mises stresses developed at the coating–substrate interface, as soon as the ball touches the coated sample, and how this state of stress influences the response of the coated system under the corrosion environment, are presented and discussed. The results obtained from these calculations, as well as from the experiments conducted in the present research, are compared with other experiments published in the literature, where a-C:H coatings deposited on different substrates and with different coating architectures were tested in similar corrosive media. It has been determined that in those systems, where the von Mises stress in the coating, found in the vicinity of the interface, exceeds the threshold value of approximately 370MPa, coating failure with spallation will take place, regardless of the substrate nature on which this coating has been deposited. From this analysis it has been concluded that the coating yield strength is of utmost importance in conferring the a-C:H coated system there quired stability in a corrosive solution

Naturally occurring ingredients as potential antiaging cosmetics

The criteria adopted for establishing whether a determined substance has potential as a cosmetic constituent are based on the present legislation of each country. In this study, natural antiaging constituents as Fomes officinalis, rice protein and glutamic acid were pharmacologically evaluated using neuromuscular preparation. These constituents induced a neuromuscular blockade, individually and also in mixture, simulating a Botox®, but not, dimethylaminoethanol-effect. The pharmacological knowledge is beneficial since the real effect of each ingredient becomes apparent, increasing the consumer's confidence on the antiaging cosmetic.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Naturally occurring ingredients as potential antiaging cosmetics

The criteria adopted for establishing whether a determined substance has potential as a cosmetic constituent are based on the present legislation of each country. In this study, natural antiaging constituents as Fomes officinalis, rice protein and glutamic acid were pharmacologically evaluated using neuromuscular preparation. These constituents induced a neuromuscular blockade, individually and also in mixture, simulating a Botox®, but not, dimethylaminoethanol-effect. The pharmacological knowledge is beneficial since the real effect of each ingredient becomes apparent, increasing the consumer's confidence on the antiaging cosmetic.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Antimycobacterial And Cytotoxicity Activities Of Free And Liposome-encapsulated 3-(4'-bromo[1,1'-biphenyl-4-yl)-3-(4-bromo-phenyl)-n,n- Dimethyl-2-propen-1-amine

The antimycobacterial activity of 3-(4'-bromo[1,1'-biphenyl-4-yl)-3-(4- bromo-phenyl)-N,N-dimethyl-2-propen-1-amine (BBAP), free or incorporated in preformed liposomes, on extracellular M. tuberculosis H37Rv was 8 and 25 μM (MIC), respectively. Extracellular antimycobacterial activity was not significantly improved by entrapment of BBAP in liposomes, but there was a 6.1-fold reduction of BBAP cytotoxicity on J774 macrophages. Liposomal BBAP or its free form showed IC50 values of 165 and 27 μM, resulting in a selectivity index (SI=IC50/MIC) of 3.4 and 6.6, respectively. Free BBAP in concentrations from 10 to 80 μM were quite effective in eliminating intracellular M. tuberculosis while liposomal formulation was less effective at these concentrations.334871874Corbett, E.L., Watt, C.J., Walker, N., Mayer, D.B.M., Willians, B.G., Raviglione, M.C., Dye, C., (2003) Arch. Intern. Med., 163, p. 1009Vynnycky, E., Fine, P.E., (1997) Epidemiol. Infec., 119, p. 183Pandey, R., Khuller, G.K., (2005) J. Antimicrob. Chemother., 55, p. 430De Souza, A.O., Aily D., C.G., Sato, D.N., Durán, N., (1998) J. Antimicrob. Chemother., 42, p. 407De Souza, A.O., Junior, R.R.S., Ferreira-Julio, J.F., Rodriguez, J.A., Melo, P.S., Haun, M., Sato, D.N., Durán, N., (2001) Eur. J. Med. Chem., 36, p. 843De Souza, A.O., Pereira, D.G., Durán, N., (2002) Ann. Rev. Biomed. Sci., 4, p. 53De Souza, A.O., Hemerly, F.P., Busollo, A.C., Melo, P.S., Machado, G.M.C., Miranda, C.C., Santa-Rita, R.M., Durán, N., (2002) J. Antimicrob. Chemother., 50, p. 629De Souza, A.O., Santos, R.R., Sato, D.N., De Azevedo, M.M.M., Ferreira, D.A., Melo, P.S., Haun, M., Durán, N., (2004) J. Braz. Chem. Soc., 15, p. 682De Souza, A.O., Alderete, J.B., Faljoni-Alario, A., Silva, C.L., Durán, N., (2005) J. Chil. Chem. Soc., 50, p. 591De Conti, R., Gimenez, S.M.M., Haun, M., Pilli, R.A., De Castro, S.L., Durán, N., (1996) Eur. J. Med. Chem., 31, p. 915Bangham, A.D., Standish, M.M., Watkins, J.C., (1965) J. Mol. Biol., 13, p. 238Chen, P.S., Toribara, T.Y., Warner, H., (1956) Anal. Chem., 28, p. 1756Oh, Y.K., Nix, D.E., Straubinger, R.M., (1995) Antimicrob. Agents Chemother., 39, p. 2104Collins, L.A., Franzblau, S.G., (1997) Antimicrob. Agents Chemother., 41, p. 1004Denizot, F., Lang, R., (1986) J. Immun. Methods, 89, p. 27

Naturally occurring ingredients as potential antiaging cosmetics

The criteria adopted for establishing whether a determined substance has potential as a cosmetic constituent are based on the present legislation of each country. In this study, natural antiaging constituents as Fomes officinalis, rice protein and glutamic acid were pharmacologically evaluated using neuromuscular preparation. These constituents induced a neuromuscular blockade, individually and also in mixture, simulating a Botox®, but not, dimethylaminoethanol-effect. The pharmacological knowledge is beneficial since the real effect of each ingredient becomes apparent, increasing the consumer's confidence on the antiaging cosmetic.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Indicadores De Desempenho Motor Como Preditores De Fragilidade Em Idosos Cadastrados Em Uma Unidade De Saúde Da Família

This study aimed to identify the motor performance tests more strongly associated with frailty and respective cut-off points and verify the best motor performance indicator as screening tool to discriminate frailty in elderly registered in Family Health Unit Participated in the study 139 elderly aged ≥60 years 105 women and 34 men The frailty was identified by the criteria of Fried et al (2001) The motor performance tests realized were: Handgrip strength (HS) sit-to-stand test walk test (WT) and pick up a pen test Logistic regression analysis was used to associate the motor performance tests and frailty The cutoff points were evaluated by parameters provided by Receiver Operating Characteristic curve (ROC) with significance level of 5% Data were analyzed using SPSS 210 and MedCalc The mean age was 7232 ± 84 The walk test was positively associated with frailty (OR 130; p <001) and handgrip strength in elderly women was inversely associated with frailty on feminine sex (OR 074; p <0001) The WT presented a cutoff 5s (sensitivity 889 and specificity 745%) and the handgrip in the women obtained a cutoff point 146 kgf (sensitivity 833 and specificity 790%) It was concluded that the walk test was the best screening indicator to discriminate the frailty in elderly both sexes registered in a Family Health Unit. © Edições Desafio Singular.122889

Fatigue behavior of a structural steel coated with a WC–10Co–4Cr/Colmonoy 88 deposit by HVOF thermal spraying

The fatigue behavior of a SAE 4340 steel, coated with a 50% WC–10Co–4Cr/50% Colmonoy 88 deposit, by high velocity oxygen fuel (HVOF) thermal spray, has been investigated. The change in the maximum alternating stress with the number of cycles to fracture has been described by means of the relationship advanced by Stromeyer. A fractographic analysis has been carried out on some representative fracture surfaces, by means of scanning electron microscopy (SEM) techniques. The mechanical properties of the coating were characterized by means of nanoindentation tests. The results indicate that the coating is highly heterogeneous. Its deposition gives rise to a decrease in the fatigue strength of the substrate of ∼ 30%, in comparison with the uncoated substrate. The decrease in fatigue strength is due to the presence of stress concentrators at the substrate–coating interface, as well as the intrinsic characteristics of the coating

Analysis of the influence of the different times of polymerization by incandescent light in composite resins by evaluation of its abrasive wear

No mercado atual a qualidade é necessária na fabricação dos produtos. No mercado odontológico, as resinas compostas são cada vez mais utilizadas para substituir materiais tradicionais, como amalgama, nas restaurações estéticas e funcionais, apresentando boa estética e funcionalidade. A composição química destes materiais é variável e os resultados das reações químicas do processo de polimerização são bastante desconhecidos. O objetivo deste trabalho era medir a resistência do desgaste abrasivo de seis resinas compostas vendidas no mercado brasileiro polimerizadas com tempos de 10, 20 e 40 segundos. O método do disco retificado modificado para aplicações em odontologia foi usado para tornar esta proposta viável. Neste banco de ensaios um disco dinâmico, revestido por porcelana, desgasta um disco estático revestido do tipo de resina que se pretende avaliar, que foi polimerizada durante um tempo pré-estabelecido. Com a determinação do desgaste de material, num determinado tempo, determinava-se a agressividade (capacidade de um material para desgastar outro material) do disco dinâmico sobre o disco estático. Utilizando-se para isso um programa computacional (LabView). Posteriormente era feita a regressão linear dos valores obtidos e determinado o coeficiente angular, utilizado no cálculo de agressividade. Valores elevados de agressividade indicam uma maior agressão do disco dinâmico contra o disco estático. Os resultados mostraram um comportamento variável para cada material que foi polimerizado nos diferentes tempos de polimerização utilizado, mostrando que o método para fazer estudos de desgaste é prático e rápido para testar materiais novos antes da sua utilização.1317787Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Não temIn the current market an increasing quality is demanded to manufacture products. At the odontologic market the composed resins are becoming more and more used to replace old materials, like amalgamates in the aesthetic and functional restorations, since they present a better appearance and easier manuscript. The chemical composition of these materials varies and the results of the chemical reactions of polymerization processes are quite unknown. The aim of this work was to measure the resistance of the abrasive wear of six composed resins sold in Brazilian market when displayed to polymerization periods of 10, 20 and 40 seconds. The grinding disc method appropriated for odontology was used to make this process possible. For this a bank of assays in which a porcelain covered dynamic disc consumes a static disc recovered by the polymerized resin is used to demonstrate the method in a pre-established time. The abrasive wear was determined by the calculation of the aggressiveness (capacity of a material to consume another). This aggressiveness is determined by an initial graph of displacement for time, through the computational method (LabView program). After they have passed through a linear regression the results give as a possibility the angular coefficient, considered a parameter at the calculation of aggressiveness. Higher values of aggressiveness which means a higher aggression suffered by the resin disc indicate worse resistance to the abrasive consuming of this resin in relation to porcelain. The results showed a variable comportment for each material ahead the different polymerization time, which prove the importance in create a practical and fast analyses method to test new materials before their us