Complexos imínicos de cobre com atividade antiparasitária frente à doença de chagas / Imine copper complexes with antiparasitic activity against Chagas disease

Neste trabalho foram sintetizados e caracterizados três complexos de cobre com ligantes imínicos, com o objetivo de avaliar sua atividade tripanocida. Esses complexos foram caracterizados por diversas técnicas espectroscópicas, como UV-Vis, Infravermelho e EPR, além de análise elementar e espectrometria de massa. Juntamente com outros complexos similares previamente sintetizados pelo nosso grupo, tiveram suas atividades avaliadas frente à forma tripomastigota do parasita T. cruzi, responsável pela fase aguda da doença de Chagas, por ensaios de viabilidade celular, com determinação do valor de seus IC50, concentração em que observamos a morte de 50% da cultura celular, pela metodologia denominada MTT. Todos os complexos mostraram-se eficientes frente a tripomastigotas, apresentando valores de IC50 abaixo de 10 µM, com quatro deles obtendo índice de seletividade maior que 10, fator importante para definir agentes promissores antichagásicos. Complexos selecionados também tiveram sua atividade verificada frente à forma amastigota do parasita, responsável pela fase crônica da doença, utilizando método de imageamento por microscópio de fluorescência e contagem celular. Estudos de inibição da cruzaína, uma cisteíno-protease importante para o metabolismo do parasita foram conduzidos em colaboração com o laboratório do Prof. Wagner Alves de Souza Júdice, da Universidade de Mogi das Cruzes. Quatro dos compostos testados apresentaram atividade inibitória frente a cruzaína, sendo dois de cobre, um de zinco e um ligante livre. Os estudos também permitiram diferenciar os mecanismos de inibição dos compostos, com os complexos de cobre apresentando um mecanismo de inibição clássico e o composto de zinco e o ligante livre apresentando o mecanismo de inibição competitiva parabólica com cooperatividade

In this work, three copper complexes with iminic ligands were synthesized and characterized, with the objective of evaluating their trypanocidal activity. These complexes were characterized by several spectroscopic techniques, such as UV-Vis, Infrared and EPR, in addition to elementary analysis and mass spectrometry. Together with other similar complexes previously synthesized by our group, their activities were evaluated against the trypomastigote form of the parasite T. cruzi, responsible for the acute phase of Chagas disease, by cell viability tests, with determination of the value of their IC50, concentration in that we observed the death of 50% of the cell culture, by the methodology called MTT, all presenting IC50 values below 10 µM, with four of them obtaining a selectivity index greater than 10, important factor for defining promising antichagasic agents. Selected complexes also had their activity verified against the amastigote form of the parasite, responsible for the chronic phase of the disease, using a fluorescence microscope and cell counting imaging method. Inhibition studies of cruzain, a cysteine protease important for the metabolism of the parasite, were conducted in collaboration with the laboratory of Professor Wagner Alves de Souza Júdice at the University of Mogi das Cruzes. Four of the tested compounds showed inhibitory activity against cruzain, two of copper, one of zinc and a free ligand. The studies also allowed to differentiate the mechanisms of inhibition of the compounds, with the copper complexes presenting a classic inhibition mechanism and the zinc compound and the free ligand presenting the competitive parabolic inhibition mechanism with cooperativity

Copper II - polar amino acid complexes: toxicity to bacteria and larvae of Aedes aegypti

ABSTRACT Control strategies using insecticides are sometimes ineffective due to the resistance of the insect vectors.In this scenario new products must be proposed for the control of insect vectors.The complexes L-aspartate Cu (II) and L-glutamate-Cu (II) complexes were synthesized and characterized by elemental analysis, visible ultraviolet, infrared spectroscopy and potentiometric titration. The toxicity of these complexes was analyzed in Aedes aegypti (Diptera: Culicidae) larvae and Gram-negative and Gram-positive bacteria. The interaction between the ligands and the amino acid balance and the distribution of the species as a function of pH were discussed. The lethal concentration median (LC50) for Ae. aegypti larvae were: L-glutamic acid-Cu (II) - 53.401 mg L-1 and L-aspartate-Cu (II) - 108.647 mg L-1. The minimum inhibitory concentration (MIC) required for Staphylococcus aureus and Escherichia coli was: L-glutamate-Cu (II) 500-2000 mg L-1 and L-aspartate-Cu (II) 1000-2000 mg L-1. The concentrations demonstrated toxicity that evidence the potential of the complexes as bactericide and insecticide. Metal complexes formed by amino acids and transition metals are advantageous because of low environmental toxicity, biodegradability and low production cost.

Diseño y evaluación de las propiedades antibacterianas de un prototipo de molde de audífono que incorpora cobre en su manufactura / Design and evaluation of antibacterial properties of a prototype of earmold with copper incorporated in the manufacture

Introducción: La otitis externa infecciosa es una consulta otorrinolaringológica frecuente en usuarios de audífonos. Las propiedades antibacterianas descritas del cobre, han motivado el desarrollo de aplicaciones clínicas de este metal. Objetivo: Evaluar la capacidad antibacteriana de moldes de audífonos manufacturados con polímeros sensible a luz UV, silicona y acrílico que incorporan cobre metálico, en un sistema experimental in vitro. Material y método: Se diseñaron moldes de audífonos con y sin cobre, que fueron inoculados con distintas concentraciones de microorganismos (S aureus y P aeruginosa), para luego determinar el porcentaje de adherencia bacteriana a distintos tiempos de contacto (4, 8 y12 horas). Resultados: Existió reducción significativa en la adhesión bacteriana a los moldes con cobre respecto a aquellos sin cobre, independiente del material, del tipo de microorganismo y del inóculo bacteriano. Discusión: La disminución en la adherencia bacteriana en los prototipos con cobre, puede atribuirse a su actividad inhibitoria sobre los microorganismos en función de su concentración y el tiempo de contacto, ejerciendo su efecto por difusión a través de los distintos materiales. Conclusión: Con estos resultados, se hace necesario el desarrollo de estudios clínicos enfocados en comprobar si el uso de audífonos con cobre disminuyen las otitis externas de origen infeccioso.

Introduction: External otitis of infectious etiology among hearing aid users is a common motive of otolaryngology consultation. Antibacterial properties described copper, they have motivated the development of clinical applications of this metal. Aim: Evaluate the antibacterial capacity of copper-based ear molds manufactured with different materials such UV sensitive polymers, silicone and acrylic incorporating metallic copper, in an experimental system in vitro. Material and method: Ear molds with and without copper, were inoculated with different concentrations of microorganisms (S aureus and P aeruginosa) and determine the percentage of bacterial adherence to different contact times (4-8 and 12 hours). Results: There was significant reduction in bacterial adhesion to copper molds than those without copper, independent of the material, the type of microorganism and the bacterial inoculum. Discussion: The decrease in bacterial adherence on prototypes with copper, can be attributed to inhibitory activity on microorganisms depending on their concentration and contact time, exerting its effect by diffusion through the various materials. Conclusion: With these results, is necessary the development of clinical studies focused on checking whether the use of hearing aids with copper decreases external otitis of infectious origin.

Copper-induced adaptation, oxidative stress and its tolerance in Aspergillus niger UCP1261

Background The effects of exposure to copper, during growth, on the production of biomass, total protein, catalase, glutathione-S transferase, glutathione peroxidase, peroxidase, polyphosphate, acid and alkaline phosphatases, ultrastructure and the ability to remove this metal from Aspergillus niger, obtained from caatinga soil, were evaluated. Results All parameters tested were influenced by the concentration of metal in the culture medium. The presence of metal induced high levels of antioxidant enzymes, including lipid peroxidation, thereby revealing the appearance of an oxidative stress response. The variation in polyphosphate levels indicates the participation of the polymer in response to stress induced by copper. The activities of the phosphatases were positively influenced by growing them in the presence of copper. Ultrastructure changes in the cell surface, electron density, thickness, and septation were visualized by exposing cells to increasingly larger concentrations of metal. The isolate was able to remove the agent from the growth medium, while maintaining its physiological functions. The metal removed from the cultures exposed to 0.5 mM, 1 mM and 2 mM copper exhibited percentages of removal equivalent to 75.78%, 66.04% and 33.51%. Conclusions The results indicate that the isolate was able to grow in high concentrations of copper, activates mechanisms for adaptation and tolerance in the presence of metal, and is highly efficient at removing the agent. Such data are fundamental if a better understanding is to be reached of the cellular and molecular abilities of native isolates, which can be used to develop bioprocesses in environmental and industrial areas.

Mechanical properties of NiTi and CuNiTi wires used in orthodontic treatment. Part 2: Microscopic surface appraisal and metallurgical characteristics

OBJECTIVE: This research aimed at comparing the qualitative chemical compositions and the surface morphology of fracture regions of eight types of Nickel (Ni) Titanium (Ti) conventional wires, superelastic and heat-activated (GAC, TP, Ormco, Masel, Morelli and Unitek), to the wires with addition of copper (CuNiTi 27oC and 35oC, Ormco) after traction test. METHODS: The analyses were performed in a scanning electronic microscope (JEOL, model JSM-5800 LV) with EDS system of microanalysis (energy dispersive spectroscopy). RESULTS : The results showed that NiTi wires presented Ni and Ti as the main elements of the alloy with minimum differences in their composition. The CuNiTi wires, however, presented Ni and Ti with a significant percentage of copper (Cu). As for surface morphology, the wires that presented the lowest wire-surface roughness were the superelastic ones by Masel and Morelli, while those that presented the greatest wire-surface roughness were the CuNiTi 27oC and 35oC ones by Ormco, due to presence of microcavity formed as a result of pulling out some particles, possibly of NiTi. 4 The fracture surfaces presented characteristics of ductile fracture, with presence of microcavities. The superelastic wires by GAC and the CuNiTi 27oC and the heat-activated ones by Unitek presented the smallest microcavities and the lowest wire-surface roughness with regard to fracture, while the CuNiTi 35oC wires presented inadequate wire-surface roughness in the fracture region. CONCLUSION: CuNiTi 35oC wires did not present better morphologic characteristics in comparison to the other wires with regard to surfaces and fracture region. .

OBJETIVO: objetivou-se nessa pesquisa comparar as composições químicas qualitativas e as morfologias das superfícies e das regiões de fratura, após ensaios de tração, de oito tipos de fios de NiTi superelásticos e termoativados convencionais (GAC, TP, Ormco, Masel, Morelli e Unitek) aos fios com adição de cobre (CuNiTi 27°C e 35°C, da Ormco). MÉTODOS: as análises foram realizadas em microscópio eletrônico de varredura (JEOL, modelo JSM-5800 LV) com sistema de microanálise EDS (energy dispersive spectroscopy). RESULTADOS: os resultados mostraram que os fios de NiTi ensaiados apresentaram Ni e Ti como os principais elementos da liga, com diferenças mínimas em suas composições. Os fios de CuNiTi, por sua vez, apresentaram Ni e Ti, com percentual significativo de cobre (Cu). Em relação às morfologias das superfícies, os fios que apresentaram os melhores acabamentos foram os superelásticos da Masel e Morelli, e os que apresentaram os piores acabamentos foram os de CuNiTi 27°C e 35°C, da Ormco, graças à presença de microcavidades formadas devido ao arrancamento de partículas, possivelmente de NiTi 4 . As superfícies de fratura apresentaram características de fratura dúctil, com a presença de microcavidades. Os fios superelásticos da GAC e de CuNiTi 27°C, bem como os termoativados da Unitek, apresentaram as menores microcavidades e os melhores acabamentos à fratura, enquanto os fios de CuNiTi 35° apresentaram acabamentos inadequados das regiões de fratura. CONCLUSÃO: os fios de CuNiTi 35°C não apresentaram características morfológicas mais adequadas das superfícies e das regiões de fratura em relação aos demais fios. .

Application of pollution indices for evaluation of heavy metals in soil close to phosphate fertilizer plant, Assiut, Egypt

Pollution indices were used to investigate the levels of heavy metal concentrations in a polluted area under the effect of fertilizer plant emissions at Manqabad, Assiut. Huge amounts of dusts, fumes and gases containing heavy metals which are released from the industrial processing activities, precipitated in the neighbouring area by the effect of meteorological factors causing soil pollution. Soil samples were taken from the area downwind of the factory and analyzed to detect concentration of heavy metals in the study area. Results of soil analysis showed that the area has been harmfully affected by the heavy metals: Cd, Cu, Pb and Zn and their average concentrations are 0.3 mg/kg, 57.0 mg/kg, 94.7 mg/kg and 80.7 mg/kg respectively. These values exceeded the concentrations in soil background [0.013 mg/kg for Cd, 9.62 mg/kg for Cu, 5.17 mg/kg for Pb and 11.56 mg/kg for Zn] obtained from unpolluted area far from industrial activities and also exceeded the international standards for soil pollution stated by WHO. Pollution indices were developed to evaluate the levels of soil pollution with heavy metals. Index of geo-accumu!ation [Igeo], Enrichment Factor [EF], Pollution Index [PI], and Load Pollution Index [LPI], were estimated. The calculated results of contamination degree showed that the investigated area lies under the class of high pollution. In final conclusion, the investigated area is highly affected by emissions from the fertilizer plant So control measures should be applied to the fertilizer plant and the polluted soil area adjacent to the factory should be remediate

Mechanical properties of NiTi and CuNiTi shape-memory wires used in orthodontic treatment. Part 1: stress-strain tests

OBJECTIVE: This research aimed to compare, through traction tests, eight types of superelastic and heat-activated NiTi archwires, by six trade companies (GAC, TP, Ormco, Masel, Morelli and Unitek) to those with addition of copper (CuNiTi 27ºC and 35ºC, Ormco). METHODS: The tests were performed in an EMIC mechanical testing machine, model DL10000, capacity of 10 tons, at the Military Institute of Engineering (IME). RESULTS: The results showed that, generally, heat-activated NiTi archwires presented slighter deactivation loadings in relation to superelastic. Among the archwires that presented deactivation loadings biologically more adequate are the heat-activated by GAC and by Unitek. Among the superelastic NiTi, the CuNiTi 27ºC by Ormco were the ones that presented slighter deactivation loadings, being statistically (ANOVA) similar, to the ones presented by the heat-activated NiTi archwires by Unitek. When compared the CuNiTi 27ºC and 35ºC archwires, it was observed that the 27ºC presented deactivation forces of, nearly, ⅓ of the presented by the 35ºC. CONCLUSION: It was concluded that the CuNiTi 35ºC archwires presented deactivation loadings biologically less favorable in relation to the other heat-activated NiTi archwires, associated to lower percentage of deformation, on the constant baselines of deactivation, showing less adequate mechanical behavior, under traction, in relation to the other archwires.

OBJETIVO: o objetivo dessa pesquisa foi comparar, por meio de ensaios de tração, oito tipos de fios de NiTi superelásticos e termoativados, de seis empresas comerciais (GAC, TP, Ormco, Masel, Morelli e Unitek) àqueles com adição de cobre (CuNiTi 27ºC e 35ºC, da ORMCO). MÉTODOS: os ensaios foram realizados em máquina de ensaios mecânicos, da marca EMIC, modelo DL10000, de 10 toneladas de capacidade, no Instituto Militar de Engenharia (IME). RESULTADOS: os resultados mostraram que, de forma geral, os fios de NiTi termoativados apresentaram cargas mais suaves de desativação que os superelásticos. Entre os fios que apresentaram as cargas de desativação biologicamente mais adequadas, estão os termoativados da GAC e da Unitek. Entre os fios de NiTi superelásticos, os de CuNiTi 27ºC da Ormco foram os que apresentaram as cargas mais suaves de desativação, sendo estatisticamente semelhantes (ANOVA) às apresentadas pelos fios de NiTi termoativados da Unitek. Quando comparados os fios de CuNiTi 27ºC aos de 35ºC, observou-se que os primeiros apresentaram forças de desativação de, aproximadamente, ⅓ das apresentadas pelos últimos. CONCLUSÃO: conclui-se que os fios de CuNiTi 35ºC apresentaram cargas de desativação biologicamente menos favoráveis em relação aos demais fios de NiTi termoativados, sendo associadas a percentuais inferiores de deformação, nos patamares constantes de desativação, demonstrando comportamento mecânico, sob tração, menos adequado em relação aos demais fios.

Supplementation of soft drinks with metallic ions reduces dissolution of bovine enamel

OBJECTIVE: The aim of this study was to evaluate the effect of the addition of metallic ions to carbonated drinks on their erosive potential. MATERIAL AND METHODS: Powdered enamel was added to carbonated beverages (Coca-ColaTM or Sprite ZeroTM and shaken for 30 s. The samples were then immediately centrifuged and the supernatant removed. This procedure was repeated 5 times with the beverages containing Cu2+, Mg2+, Mn2+ or Zn2+ (1.25-60 mmol/L). For Coca-ColaTM, the concentration of each ion that exhibited the highest protection was also evaluated in combination with Fe2+. The phosphate or calcium released were analyzed spectrophotometrically. Data were analyzed using ANOVA and Tukey's test (p<0.05). RESULTS: For Coca-ColaTM, the best protective effect was observed for Zn2+ alone (10 mmol/L) or in combination (1 mmol/L) with other ions (12% and 27%, respectively, when compared with the control). Regarding Sprite ZeroTM, the best protective effect was observed for Cu2+ at 15 and 30 mmol/L, which decreased the dissolution by 22-23%. Zn2+ at 2.5 mmol/L also reduced the dissolution of powdered enamel by 8%. CONCLUSIONS: The results suggest that the combination of metallic ions can be an alternative to reduce the erosive potential of Coca-ColaTM. Regarding Sprite ZeroTM, the addition of Cu2+ seems to be the best alternative. .

Efecto de la estacionalidad sobre el estado nutricional de Hierro, Zinc y Cobre / Effect of seasonality on nutritional status of Iron, Zinc and Copper

Food consumption and therefore the nutritional status of micro-nutrients are influenced by various factors such as seasonality. This study aimed to determine the effect of seasonality on the nutritional status of Fe, Zn and Cu in adult subjects. A longitudinal study was conducted during the months of September 2005 and August 2006. Fifty subjects of both sexes belonging to the urban area of the city of Santiago de Chile were evaluated. Blood samples were drawn during the first week of each month; serum iron, copper and zinc, hemoglobin, mean cell volume, serum ferritin, zinc-protophorphyrin and ceruloplasmin were determined. Serum copper and zinc levels showed significant seasonal variations but not serum iron. Mean cell volume, hemoglobin and ceruloplasmins were significantly lower during spring and summer while serum ferritin and zinc-protophorphyrin showed lower concentrations during autumn and winter. We conclude that during the spring and summer levels of serum iron, copper and zinc could be diminished by reduced food intake.

El consumo de alimentos y por lo tanto el estado de nutrición de los micronutrientes está condicionado por diferentes factores como la estacionalidad. El presente estudio tuvo como objetivo determinar el efecto de la estacionalidad sobre el estado nutricional de hierro, zinc y cobre de sujetos adultos habitantes de la ciudad de Santiago de Chile. Un estudio longitudinal en 50 sujetos de ambos sexos se realizó entre los meses de septiembre del 2005 y agosto del 2006. Durante la primera semana de cada mes se extrajo muestras de sangre para la determinación de hierro, zinc y cobre sérico, hemoglobina, volumen corpuscular medio, ferritina sérica zinc-protoporfirina y ceruloplasmina. Los niveles de cobre, zinc, hemoglobina, volumen corpuscular medio, y ceruloplasmina fueron significativamente menores durante primavera y verano mientras ferritina sérica y zinc-protoporfirina presentaron niveles más bajas durante otoño e invierno. Concluimos que la estacionalidad es un factor a considerar cuando se realicen mediciones de estado de nutrición de los microminerales hierro, zinc y cobre.

Dark and photoelectric investigation on thin films of Copper Phthalocyanine

Schottky barrier diode based on copper phthalocyanine [CuPc] with binder polymer [polycarbonate MK] has been fabricated and characterized using indium as Schottky contact and gold [Au] as an ohmic contact. A complete study of the current as a function of voltage and temperature is carried out. At low voltages, the current in the forward direction varies exponentially with voltage. At higher voltages, two separate regions of ohmic and space charge limited conduction [SCLC] are observed. The latter process is controlled by an exponential distribution of traps above the valence band edge .Analysis of the results enables the determination of the important trapping parameters. Reverse characteristics are interpreted in terms of both the Poole - Frenkel and Schottky effects. Barrier heights and widths are determined as a function of applied voltage. The photovoltaic parameters of the cells are determined from the analysis of the current - voltage characteristics under illumination. Trap density and Schottky barrier built in potential are estimated from capacitance-voltage measurements

Suplementos nutricionales orales a base de nuevos complejos de cobre, magnesio, manganeso y zinc

Suplementos nutricionales orales a base de nuevos complejos de cobre, magnesio, manganeso y zinc Los oligoelementos cobre, magnesio, manganeso y zinc intervienen en numerosos procesos metabólicos, enzimáticos, inmunológicos y tisulares, forman parte estructural de proteínas y pueden participar en la regulación de la expresión genética. La deficiencia de estos elementos esenciales dificulta el apropiado funcionamiento del organismo e induce el desarrollo de diversas enfermedades. Se debe garantizar la incorporación de oligoelementos a través de la dieta; sin embargo, la cantidad suministrada no siempre es suficiente y el uso de suplementos nutricionales convencionales presenta dos problemas; el primero se atribuye a la asociación de los metales a sales inorgánicas que generan una baja absorción e intolerancias a nivel gástrico y el segundo corresponde a las interacciones antagonistas entre diversos metales componentes de la formulación. Como una alternativa a los problemas mencionados, en este trabajo se propone la elaboración de tabletas para la administración oral de nuevos complejos de cobre, zinc, magnesio y manganeso ligados a los aminoácidos glicina y asparagina. En la síntesis de estos complejos, cada ligando se unió a duplas de cationes no antagonistas, se verificó la formación de los complejos por espectroscopía infrarroja, calorimetría de barrido diferencial, análisis termogravimétrico y difracción de rayos X de polvos, y se determinaron los tiempos de desintegración y de disolución in-vitro a las formas farmacéuticas finales.

Oral dietary supplements with copper, magnesium, manganese and zinc-based new complexes Oligoelements such as copper, magnesium, manganese and zinc are involved in several metabolic, enzymatic and immunological processes. They are also important for the integral tissue proteins and could be involved in gene expression regulation. The deficiency of these essential elements hampers the appropriate function of the body and may cause various diseases. Therefore, it is important to guarantee the incorporation of these trace elements in the diet, but the quantity provided is not always adequate for the optimum body performance. Currently, conventional nutritional supplements have two major problems. The first one is attributed to the association of inorganic salts with metals which might cause low absorption and gastric intolerance. The second problem is caused when several metals are present in a formulation which could lead to possible antagonistic interactions. For this reason, this study explores the development of cations (i.e., copper, zinc, magnesium and manganese) and amino acids (i.e., glycine and asparagine) new complexes formulated into compacts for oral administration. In each reaction, ligands were linked to non-antagonistic cation pairs. The complex formation was characterized by infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis and powder X-ray diffraction analyses. Compact disintegration and in-vitro dissolution tests for these complexes were also determined.

SAD phasing with in-house Cu Kα radiation using barium as anomalous scatterer.

Phasing of lysozyme crystals using co-crystallized barium ions was performed using single-wavelength anomalous diffraction (SAD) method using Cu Kα radiation with in-house source of data collection. As the ion binding sites vary with respect to the pH of the buffer during crystallization, the highly isomorphic forms of lysozyme crystals grown at acidic and alkaline pH were used for the study. Intrinsic sulphur anomalous signal was also utilized with anomalous signal from lower occupancy ions for phasing. The study showed that to solve the structure by SAD technique, 2.8-fold data redundancy was sufficient when barium was used as an anomalous marker in the in-house copper X-ray radiation source for data collection. Therefore, co-crystallization of proteins with barium containing salt can be a powerful tool for structure determination using lab source.

Repair of amalgam restorations with composite resin and bonded amalgam: A microleakage study.

Background: Total replacement is the most common technique for defective amalgam restorations, and it represents a major part of restorative dental treatment. Repair is an alternative option for amalgam restorations with localized defects. Aims: This study compared microleakage of amalgam restorations repaired by bonded amalgam or composite resin. Materials and Methods: Thirty extracted human pre-molars were prepared and restored with class I amalgam. A simulated defect was prepared that included the cavosurface margin on restorations, and the pre-molars were assigned to two treatment groups (n=15): In group 1, premolars were treated by composite resin (34% Tooth Conditioner Gel + Adper Single Bond 2 + Z100) and in group 2, premolars were repaired by bonded amalgam (34% Tooth Conditioner Gel + Prime and Bond 2.1 + Permite C). The teeth were immersed in a 50% silver nitrate solution, thermocycled, sectioned longitudinally and then observed by three examiners using a stereomicroscope. Microleakage was evaluated using a 0-4 scale for dye penetration, and data was analyzed by Kruskal Wallis and Dunn tests. Results: Neither of the two methods eliminated microleakage completely. Composite resin was significantly the most effective for repair/tooth interface sealing (score 0 = 80.0%; P=0.0317). For the repair/restoration interface, composite resin was also statistically more effective as a sealant (score 0=66%; P=0.0005) when compared to the bonded amalgam technique (score 0=13%; P=0.0005). Conclusions: The use of adhesive systems significantly affected the ability to seal the repair/ tooth interface. However, at the level of the repair/restoration interface, the bonded amalgam technique may increase microleakage.

Construction of a copper stepwedge with aluminum equivalent mean gray values

OBJECTIVES: To produce a copper (Cu) stepwedge with aluminum (Al) equivalent mean gray values (MGV). MATERIAL AND METHODS: The thicknesses of Cu steps that were equivalent to those of the Al were formulated using the X-ray attenuation properties of the materials. The Al and fabricated Cu stepwedges were radiographed, but the MGVs of the Cu stepwedge were mismatching to those of the Al. Using a mathematical function to adjust the pixel MGV of Cu stepwedge to those of the Al, new Cu stepwedges were created. In vitro iterations were performed until best approximation to Al was reached. RESULTS: The MGV of the Cu stepwedges fabricated by formularization were different than those of Al (p=0.001). Iteration method led to MGV similar to those of the Al stepwedge (p=0.207). CONCLUSIONS: Construction of a Cu stepwedge according to the basic rules of radiophysic failed to result in a stepwedge with similar radiodensity values to those of Al stepwedge. Further studies may use the formularization method only for prototype Cu wedge production, but consecutive iterations shall be compassed to obtain the best approximation to Al MGV.

Detection of metal elements of skin in electric injury by inductively coupled plasma mass spectrometry / 法医学杂志

OBJECTIVE@#To explore the feasibility of the detection of metal elements of skin in electric injury using inductively coupled plasma mass spectrometry (ICP-MS), and to establish a method to detect metal elements of skin in electric injury.@*METHODS@#Brass, copper, aluminum and iron were used as electrodes to make electrical marks on rabbit hindlimb (220V AC), and then ICP-MS was used to detect the metal elements in injured skin.@*RESULTS@#Comparing with control group,the levels of Cr, Ni, Cu, Zn and Pb showed higher in the group of brass shock (P < 0.05); the levels of Cr, Cu and Pb were higher in group of the copper shock (P < 0.05); the levels of Al, Cr, Mn, Co, Ni, Cu and Pb displayed stronger in group of aluminum shock (P < 0.05); the levels of Cr, Mn, Fe and Ni showed higher in the group of iron shock (P < 0.05). The types and levels of metal elements showed the significant difference between different electrode groups after electric injury.@*CONCLUSION@#ICP-MS can be used as an effective tool to determine electric injury, and the method can be used to estimate the features of electrodes.

Synthesis, characterization and catalytic activity of copper [II], nickel [II] and cobalt [II] complexes derived from novel hydrazone drivatives of oxamic hydrazide

A series of new coordination complexes of Cu[II], Ni[II] and Co[II] with omaxic hydrazide [L[1]], N,N' - [salicylidene]- oxamic hydrazide [L[2]] and N,N' - bis [naphthalidene] - oxamic hydrazide [L[3]] have been synthesized and characterized by elemental analysis, magnetic moment, IR, UV - Vis spectra nd molar conductance. The thermal behavior of the complexes was investigated by TG A and DTA techniques. The catalytic activity of the complexes to decolorize the Allura-Red [food dye] in presence of H[2]O[2] was studied

New pH-Metric method for determination of some angiotensin converting enzyme inhibitors through their complex formation with some transition metal ions

Study of mixed ligand complexes of Co[2+] and Zn[2+] with three Angiotensin converting enzyme inhibitors [ACE] was conducted in aqueous solution by pH metric titration. These are Enalapril maleate [I], Perindopril [II] and Moexipril [III] and one of the amino acid family [glycine]. Protonation constants of the three drugs and stability constants of the binary and ternary complexes were determined at [25 +/- 1] [degree sign] C and ionic strength 0.1M NaCl. The stability constants of the binary complexes of I, II and III with Co[2+] and Zn[2+] were performed and the results indicate the presence of one formation constant for the complexes of Co[2+] and Zn[2+] ions with II and III and two formation constants for I. By introducing glycine in the above binary complexes, ternary complexes were formed. The formation constant of the ternary complexes of I, II and III with Co[2+] and Zn[2+] ions with glycine was also calculated at the same temperature and ionic strength. This potentiometric technique was utilized also for the determination of the cited drugs

Chemical composition, metals content and pesticide residues in raw, pasteurized and UHT milk and their dietary intake

Chemical composition, metal contents and pesticide residues were determined in raw, pasteurized and UHT [Ultra High Temperature] milk samples collected from local markets in Cairo Governorate, Egypt. Fat, T.P. [Total Protein], ash, lactose and T.S. [Total Solids] contents were [3.50, 3.20, 0.71, 4.10 and 11.40%], [3.00, 3.50, 0.80, 4.65 and 11.50%], and [3.00, 3.40, 0.80, 4.44 and 11.50%] in raw, pasteurized and UHT milk, respectively. Levels of Zn, Fe, Cu, Mn, Cr, Ni, Co, Pb, Cd and Sn were [3.59, 0.62, 0.17, 0.06, 0.03, 0.036, 0.032, 0.032, 0.025 and 0.002 mg/kg], [3.11, 0.55, 0.15, 0.041, 0.030, 0.030, 0.030, 0.021, 0.022 and 0.002 mg/kg] and [3.11, 0.60, 0.180, 0.050, 0.020, 0.030, 0.030, 0.020, 0.020 and 0.002 mg/kg] in raw, pasteurized and UHT milk, respectively. Organochlorine pesticides [HCB, lindane, aldrin, heptachlor, heptachlor epoxide, chlordane, endrin and DDT metabolites] were detected in raw milk at levels higher than the tolerance limits. However, these chemicals were detected in pasteurized milk at slightly higher levels and in UHT milk at levels lower than the tolerance limits. On the other hand, non of raw, pasteurized and UHT milk revealed the presence of organophosphorus pesticides [malathion, profenofos, pirmiphos-methyl and dimethoate]. To assess any possible risks to consumers of milk, dietary intakes have been estimated using the mean concentration of various metals and pesticide residues in this monitoring. Data showed that, daily intake of the investigated metals and pesticides in milk were lower than the recommended levels except that Pb and Cd are higher than it

Effect of Ag[2]O- and Mn[2]O[3]Doping of CuO/MgO-AI[2]O[3] on Its Surface and Catalytic Properties

Pure samples of CuO/MgO-Al[2]O[3] solids were prepared by wet impregnation method using a given weight of equimolar proportions of aluminum hydroxide and magnesium basic carbonate powders with calculated amounts of copper nitrate dissolved in the least amount of distilled water followed by drying and calcinations at 300 and 500°C. The doped samples were obtained by treating pure solids with a known weight of silver or manganese nitrate prior to impregnation with copper nitrate. The formulae of pure calcined solids were 0.05, 0.1 and 0.2 CuO/MgO-Al[2]O[3]. The dopant concentration was varied between 1-4 mol% Ag2[O] and 1-8 mol% Mn[2]O[3]. The results revealed that the specific surface areas of pure and doped solids decreased by increasing the calcination temperature from 300 to 500°C. The doping process resulted in a measurable increase in the BET-surface areas of all solids investigated. This process changed the catalytic activities of various solids in CO oxidation by O[2] and H[2]O[2] decomposition. Doping the solids investigated with both dopants brought about a considerable increase in the catalytic activity towards both H[2]O[2] decomposition and CO oxidation to an extent proportional to the amount of dopants added. The increase in the catalytic activity was, however, more pronounced for Ag[2]O-dopant. The increase in calcinations temperature from 300 to 500°C resulted in an increase in the catalytic activity of pure and doped solids. Activation energy calculations revealed that doping process did not modify the reaction mechanism of H[2]O[2] decomposition but rather changed the concentration of catalytically active sites without changing their energetic nature

Effect of gamma-irradiation on surface and catalytic properties of nano crystalline Fe2O3/CuO system

Ferric/copper mixed oxides samples having the formula 0.25Fe2O3/CuO were prepared by thermal decomposition of their mixed hydroxides at 400 °C. The mixed hydroxides were prepared by cooprecipitation method using iron and copper nitrates solution using NaOH at pH = 8. The obtained solid was exposed to different doses of gamma-rays varying between 0.2 MGy and 1.6 MGy. The techniques employed were XRD, nitrogen adsorption measurements at -196 °C and ethanol and isopropanol conversion using micropulse technique at temperatures between 250-400 °C. The results obtained revealed that the investigated system consisted of nano crystalline CuO [major phase] and poorly crystalline Fe2O3 as a minor phase. The exposure to gamma-irradiation resulted in a measurable decrease a the crystallite size of CuO [major phase], a dose of 1.6 MGy brought about a significant drop in the crystallite size from 31.4 to 19.2 nm. This treatment led also to a progressive increase in the BET=surface area to an extent proportional to the dose of gamma-rays employed. The investigated solid samples acted as dehydration catalysts converting ethanol and isopropanol into ethene and propene, respectively. Their activity was found to increase by increasing the dose of gamma-rays reaching to a maximum limit at a dose of 0.4 MGy. However, a dose of 0.8 MGy led to a sudden drop in the catalytic activity of various solids which retained most of their initial activity upon exposure to a dose of 1.6 MGy. The results obtained were discussed in terms of the role of gamma-rays in modifying the chemistry of the surface of the treated solids and the decrease in the crystallite size with subsequence increase in their SBET