Toxicidade de f��rmacos nitrofur��nicos

During the structural designing of new drugs, it is possible predict the influence of specific chemical groups on pharmacological activity. Among these, the nitro group has potential antiparasitic activity, being present in many antimicrobial drugs, such as metronidazole, nitrofurazone, furazolidone, oxamniquine and chloramphenicol. Also, the introduction of the nitro group into a molecule can modify the physicochemical and electronic properties of the substance. Besides antimicrobial drugs, this group is also found in other drug classes, such as antiulcer, anti-inflamatory and anxiolytic. However, the use of the nitro group in drug design has encountered restrictions, due to the associated toxicity. This article is a review of the toxicity of nitrofuran compounds, as well the possible mechanisms involved and the strategy of latentiation by molecular modification to decrease their toxicity.

Surface study of vitreous carbon obtained from glassy carbon powder

This work presents a surface study of monolithic vitreous (or glassy) carbon - MVC - obtained from vitreous carbon powder. Defective MVC pieces are crushed in a ball mill and size classified by sifting. The MVC powder is mixed with furfuryl-alcohol resin and compacted in a mould using a hydraulic press. Samples with different powder granulometries are produced in this way and carbonized in a furnace under nitrogen atmosphere. Complete carbonization of the powder is achieved in only one day and losses due to breakage of the pieces is less than 5%. These results compare very favorably with respect to traditional MVC production methods where full carbonization may require up to seven days and losses due to breakage can be as high as 70%. After carbonization, samples are sanded and polished. Surface roughness and microstructure are characterized by light microscopy. Porosity is quantified from micrographs using ImageJ software and nanometric height variations are measured by atomic force microscopy. �� 2012 Materials Research Society.

Clastogenicity of landfarming soil treated with sugar cane vinasse

The addition of nutrients and/or soil bulking agents is used in bioremediation to increase microbial activity in contaminated soils. For this purpose, some studies have assessed the effectiveness of vinasse in the bioremediation of soils contaminated with petroleum waste. The present study was aimed at investigating the clastogenic/aneugenic potential of landfarming soil from a petroleum refinery before and after addition of sugar cane vinasse using the Allium cepa bioassay. Our results show that the addition of sugar cane vinasse to landfarming soil potentiates the clastogenic effects of the latter probably due the release of metals that were previously adsorbed into the organic matter. These metals may have interacted synergistically with petroleum hydrocarbons present in the landfarming soil treated with sugar cane vinasse. We recommend further tests to monitor the effects of sugar cane vinasse on soils contaminated with organic wastes. �� 2012 Springer Science+Business Media B.V.

Interclonal Variations in the Molecular Karyotype of Trypanosoma cruzi: Chromosome Rearrangements in a Single Cell-Derived Clone of the G Strain

Trypanosoma cruzi comprises a pool of populations which are genetically diverse in terms of DNA content, growth and infectivity. Inter- and intra-strain karyotype heterogeneities have been reported, suggesting that chromosomal rearrangements occurred during the evolution of this parasite. Clone D11 is a single-cell-derived clone of the T. cruzi G strain selected by the minimal dilution method and by infecting Vero cells with metacyclic trypomastigotes. Here we report that the karyotype of clone D11 differs from that of the G strain in both number and size of chromosomal bands. Large chromosomal rearrangement was observed in the chromosomes carrying the tubulin loci. However, most of the chromosome length polymorphisms were of small amplitude, and the absence of one band in clone D11 in relation to its reference position in the G strain could be correlated to the presence of a novel band migrating above or below this position. Despite the presence of chromosomal polymorphism, large syntenic groups were conserved between the isolates. The appearance of new chromosomal bands in clone D11 could be explained by chromosome fusion followed by a chromosome break or interchromosomal exchange of large DNA segments. Our results also suggest that telomeric regions are involved in this process. The variant represented by clone D11 could have been induced by the stress of the cloning procedure or could, as has been suggested for Leishmania infantum, have emerged from a multiclonal, mosaic parasite population submitted to frequent DNA amplification/deletion events, leading to a 'mosaic' structure with different individuals having differently sized versions of the same chromosomes. If this is the case, the variant represented by clone D11 would be better adapted to survive the stress induced by cloning, which includes intracellular development in the mammalian cell. Karyotype polymorphism could be part of the T. cruzi arsenal for responding to environmental pressure. �� 2013 Lima et al.

Desempenho operacional de um subsolador de hastes com curvatura lateral (���Paraplow���), em fun����o de diferentes velocidades de deslocamento e profundidades de trabalho

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)

Efeitos de tratamentos hidrot��rmicos nas propriedades viscogr��ficas e amidos resistentes em f��culas de mandioca

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)

M��scara e representa����o no livro do Desassossego

P��s-gradua����o em Estudos Liter��rios - FCLAR

Desempenho agron��mico de h��bridos de milho em diferentes arranjos populacionais em Jaboticabal-SP

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)

Caracteriza����o agron��mica e morfol��gica de popula����es de milho

P��s-gradua����o em Agronomia (Gen��tica e Melhoramento de Plantas) - FCAV

Association among XRCC1, XRCC3, and BLHX gene polymorphisms and chromosome instability in lymphocytes from patients with endometriosis and ovarian cancer

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Opini��o de familiares sobre a interna����o de crian��as em uma Unidade de Terapia Intensiva Pedi��trica

A Pediatric Intensive care Unit (PICU) is an environment where care is provided to seriously ill children. Hospitalization is regarded as an unpleasant experience that requires adaptation and routine change. To assess the opinion of relatives of children hospitalized at a PICU concerning tie breakage and/or separation between children and their families. It is a descriptive, cross-sectional, quantitative study. A structured interview was conducted with the families of hospitalized children from July to September, 2010. The data were statistically analyzed. RESULTS: Twenty relatives were interviewed, 80% of whom believed that children���s behavior changes when they are present in the unit, and 85% considered the visitation time established to be sufficient. All the respondents reported to be satisfied about the care provided. The feelings prevailing in 50% of the relatives were fear and hope. Change in the family���s union after hospitalization occurred in 85% of the families. The most fearful aspect concerning the ICU is the equipment (25%), and the most worrisome, as regards personal life, is the separation from other children (65%). Health care professionals must pay more attention to relatives by including them in their health care plan so that the health care team and the family, who are essential in children���s recovery, can interact in a congenial fashion. It is also necessary to improve the knowledge related to that subject so that the health care team and families can work together towards children���s recovery

Otimiza����o da estrutura metalica para um carro aleg��rico

Carnival is a unique opportunity for the associations demonstrate the community���s annual work and the float is a major component of this celebration, responsible for pitch the samba using allegories and carry important figures. The excess weight of the floats which are mostly manufactured from truck and bus structures requires larger amount of people to push the vehicle in addition to increased efforts on the steering systems, suspension and wheels, raising the probability of breakage and loss of one year work. The objective of this study is to use the concepts of strength of materials combined with computer simulation to obtain a structure that has the lowest possible weight without compromising the safety of transported components and that is also easy to manufacture, drive and store

Avalia����o da usinagem do INCONEL 718

The nickel superalloys are known as being a material with poor machinability, they have some properties like high hardness, good resistance at high temperature, tendency to weld with the tool material at high temperature, etc. In the aerospace, biomedical and petrochemical industry, are increasing the need to use materials that resist to aggressive process and environment. In these uses, it has increased the use of nickel-based superalloys like Inconel 718 and consequently the need to research new techniques and tools to improve the machinability of this material. For the superalloys and resistant alloys at high temperatures is considered that the difficulty in the machining regards to the combination of the relatively high cutting forces and high temperatures that grow during the machine process, causing deformation or breakage of the cutting tool. This work purpose is to develop the study of the machining of external cylindrical turning of the nickel based alloy Inconel 718, using ceramic tools, seeking the optimization of machining this alloy, looking to provide real productive increases without the need of investments in new production means. The machining test were accomplished using commercials hard metal tools and the results were compared each other to find the best tool and the best parameter. The conclusion is that the tool TNMG160408-23 -class 1005- was the better one, when used with the parameter 60_15_08

Usinagem da liga de n��quel inconel 718 com pastilhas de cer��mica

The machining of super alloys resistant to high temperatures such as nickel alloys, inconel 718 specifically, is a very difficult job to obtain improvements in the process, due to the difficulty of machining at high cutting speeds, the use of these alloys in industries showed great developments in recent years, its application in aeronautical industry spread being used in vane turbo, compressor parts, props and set elements. The automotive, chemical, medical and others also took advantage of the great features of inconel 718 and has used the material. The high temperature resistant alloys have high machining difficulty, a fact that is associated with high cutting forces generated during machining which result in high temperatures. High levels of temperatures can cause deterioration of the cutting edge, with subsequent deformation or breakage, wear most common obtained in machining such materials are flank wear the formation of built-up edge for cutting and notch wear. The experimental part of the work consists in machining of nickel-based alloy Inconel 718 heat treated for hardness, using a tool based ceramic silicon nitride Sandvik (Si3N4) in order to compare the best results obtained in the master's thesis of SANTOS (2010) who used a tool ceramics also the basis of silicon nitride which was developed in the doctoral thesis of SOUZA (2005). Assays were performed on a CNC lathe and was noted for each cutting edge results obtained. Tests were made starting from an initial condition of the tool with cutting speed of 200 m/min, feed 0.5 mm and 0.5 mm depth of cut was reduced cutting speed for the subsequent tests with the same conditions of feed and depth of cut. The tool presented wear instant under two 200 m/min and 100 m/min, premature rupture of 50 m/min and finally cut provided with difficulty... (Complete abstract click electronic access below)

Induction of mitotic and chromosomal abnormalities on Allium cepa cells by pesticides imidacloprid and sulfentrazone and the mixture of them

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)