Refletindo sobre o caso celobar®

By mid 2003, the Brazilian people accompanied astonished, in the press, the news about the death of more than 20 persons due to ingestion of a pharmaceutical product containing a suspension of barium sulfate (Celobar®) commonly used as a radiological contrast. Analysis of the product indicated the presence of barium carbonate (about 13% weight/weight) which reacts easily with the hydrochloric acid in the stomach liberating barium ions, a severe poison. In this article, we briefly discuss the possible economic, personal and technical causes that led to this disaster.

Sobre a força de ácidos e bases: algumas considerações

This article intends to answer the question: what is the best way to evaluate the strength of acids and bases? The meaning of the word strength, the main acid-base theories (ionotropic and electron pair), the neutralization reactions and the thermodynamical formalism are considered. Some cases are presented and discussed. In conclusion, evaluating acid-base strength is dependent on the theory (formalism) as well as on the system and measuring techniques.

Alteração da atividade enzimática em organismos aquáticos por poluentes de origem agrícola: uma abordagem geral e sobre a suscetibilidade da fosfatase ácida

The input of agrochemicals in the aquatic compartment can results in biochemical injuries for living organisms. In this context, the knowledge of alterations of enzymatic activities due the presence of agriculture pollutants contributes for the elucidation of the mechanisms of toxicity, implementation of economic methods for monitoring purposes and establishment of maximum allowed concentrations. In the present work, the above considerations are discussed, and data concerning changes in enzymatic function by pesticides and fertilizer contaminants are reviewed. Also, we focused on the acid phosphatase due its susceptibility to several pollutants and diversity in cellular functions.

Curiosidades sobre a reação aldólica utilizada como etapa chave na síntese Brasileira dos ácidos pterídicos A e B

This work describes an overview of our synthesis of pteridic acids A and B and discloses some interesting results related to the lithium enolate-mediated aldol reaction used as key step to set up the C5-C15 fragment of these natural products. This first example, as far we know, of an aldol reaction between a chiral enolate of a (Z) enone and a chiral aldehyde has driven us to a series of experiments showing the remarkable relation between enolization selectivity and reaction conditions.

Uma revisão sobre o efeito Toms: o fenômeno onde macromoléculas atenuam a turbulência em um líquido

It is very well known that the addition of polymers to a liquid increases the shear viscosity of the solution. In other words, the polymer increases the dissipation of the flow energy. Contrarily, in turbulent flow, some particular macromolecules in very low concentration are able to produce large attenuation in the turbulence and thus, decreasing the dissipation of the energy. This article present a brief revision about macroscopic and molecular models used to explain this dynamic effect. Some of the experimental techniques used to quantify the attenuation of the turbulence and the main active substances are also discussed.

Química forense: perspectivas sobre novos métodos analíticos aplicados à documentoscopia, balística e drogas de abuso

In this review recent methods developed and applied to solve criminal occurences related to documentoscopy, ballistic and drugs of abuse are discussed. In documentoscopy, aging of ink writings, the sequence of line crossings and counterfeiting of documents are aspects to be solved with reproducible, fast and non-destructive methods. In ballistic, the industries are currently producing ''lead-free'' or ''nontoxic'' handgun ammunitions, so new methods of gunshot residues characterization are being presented. For drugs analysis, easy ambient sonic-spray ionization mass spectrometry (EASI-MS) is shown to provide a relatively simple and selective screening tool to distinguish m-CPP and amphetamines (MDMA) tablets, cocaine and LSD.

Atividade de extratos de Arrabidaea chica (Humb. & Bonpl.) Verlot obtidos por processos biotecnológicos sobre a proliferação de fibroblastos e células tumorais humanas

Arrabidaea chica (H&B) Verlot is a plant popularly known as Pariri and this species is a known source of anthocyanins, flavonoids and tannins. This report describes an approach involving enzymatic treatment prior to extraction procedures to enhance A chica crude extract anticancer activity. Anticancer activity in human cancer cell lines in vitro using a 48 h SRB cell viability assay was performed to determine growth inhibition and cytotoxic properties. The final extraction yield without enzyme treatment was higher (24.28%) compared to the enzyme-treated material (19.03%), with an enhanced aglycones anthocyanin ratio as determined by HPLC- DAD and LC-MS with direct infusion.

Transferência de massa e secagem em leitos vibrofluidizados: uma revisão

Development of processing technology and equipments requires new methods and better quality of the processed product. In the continuous drying process, utilization of equipments that promotes an increment in the transfer coefficients becomes of the major interest. The use of vibrational energy has been recommended to the dispersed materials. Such method is based on the use of vibrational energy applied to disperse media. Thus, a literature review on the mass transfer and drying in vibro-fluidized beds was carried out, showing experimental results and mathematical modeling.

Brazilian multicentre study of common mental disorders in primary care: rates and related social and demographic factors

Mental health problems are common in primary health care, particularly anxiety and depression. This study aims to estimate the prevalence of common mental disorders and their associations with socio-demographic characteristics in primary care in Brazil (Family Health Strategy). It involved a multicenter cross-sectional study with patients from Rio de Janeiro, São Paulo, Fortaleza (Ceará State) and Porto Alegre (Rio Grande do Sul State), assessed using the General Health Questionnaire (GHQ-12) and the Hospital Anxiety and Depression Scale (HAD). The rate of mental disorders in patients from Rio de Janeiro, São Paulo, Fortaleza and Porto Alegre were found to be, respectively, 51.9%, 53.3%, 64.3% and 57.7% with significant differences between Porto Alegre and Fortaleza compared to Rio de Janeiro after adjusting for confounders. Prevalence proportions of mental problems were especially common for females, the unemployed, those with less education and those with lower incomes. In the context of the Brazilian government's moves towards developing primary health care and reorganizing mental health policies it is relevant to consider common mental disorders as a priority alongside other chronic health conditions.

Notas sobre duas espécies de Thelypteris Schmidel (Thelypteridaceae - Pterophyta) do Brasil

During the taxonomic study of the Thelypteridaceae from southeastern Brazil was founded Thelypteris polypodioides (Raddi) C. F. Reed and Thelypteris villosa (Link) C. F. Reed, two rare and poorly known species. The taxonomic position of these species is uncertain. This study presents key, descriptions, illustrations, data on geographical distribution, and comments for both species, as well as comments on taxonomic affinity between the two species and Thelypteris subgenera.

Leguminosae, Papilionoideae no Parque Estadual do Rio Doce, Minas Gerais, Brasil. II: árvores e arbustos escandentes

This work is a floristic survey of arboreous and climbing shrub taxa of Papilionoideae in a semideciduos forest at Parque Estadual do Rio Doce, eastern Minas Gerais State. Field work was carried out from April/1998 to May/1999, when montly visits were conducted to collect botanical material along trails and of the main road. The floristic survey resulted in 22 taxa belonging to eight genera. An identification key, descriptions, illustrations and comments on the analyzed taxa are presented.

Revisão taxonômica de Leptolobium (Papilionoideae, Leguminosae)

This revision of Leptolobium Vogel includes an identification key, descriptions, illustrations, and distribution maps for the taxa. Leptolobium comprises 12 species, and is characterized by its arboreal or shrubby habit, flowers with white, actinomorphic or slightly zygomorphic corollas, 10 free stamens, a stipitate ovary with many ovules, indehiscent (samara-like or nut-like) fruits, compressed seeds, and a bulbose hypocotyl-radicle axis. Leptolobium is a neotropical genus that occurs from Mexico to northern Argentina. Eleven species are found in Brazil, seven of which are endemic to the country. The lectotype of Sweetia glazioviana Harms is designated in this paper. In addition, information about uses, common names, geographical distribution, and habitats are provided.

SEMELHANÇAS ENTRE UPTAKE E TRACE: CONSIDERAÇÕES SOBRE TRADUÇÃO

This study is a reflection about the similarities between uptake and trace, and translation taken as an event - at once possible and impossible - which deflagrates and constitutes meaning through the language game played by the subjects of communication: text-translator. Both Austin and Derrida, each one on his own way, show that meaning is part of the human language process. The uptake, in Austin s point of view, guarantees the existence of human language, assured by a process of recognition between the subjects of communication, process through which the production of meaning takes place. The trace, according to Derrida, deflagrates, through the human language, the crashing of meaning and destroys the possibility of someone reaching the origin. In this study, taking into consideration the similarities between uptake and trace, I try to disclose translation taken as an event which at once contaminates the languages and is contaminated by them.

A teoria e a prática: a questão da diferençano discurso sobre e da sala de aula

The main purpose of this paper is to question the relationship between theory and practice or basic and applied research in the domain of Applied Linguistics and classroom discourse. In order to achieve our aim, some theoretical texts, some recorded and transcribed classes as well as some teachers and students opinions about reading and writing were analysed. Results have shown that 1) practice is not the direct application of theoretical data: the relationship between them is not as simple as some applied linguists seem to believe because of the action of the unconscious in the constitution of subjectivity; 2) the conceptualization of the theoretical issues takes place in a confused and disorderly manner mixed up with personal experiences and previous knowledge (practice). We intend to question the fact that practice comes as secondary to theory.

Uma observação sobre o lugar da teoria da ligação e do critério temático dentro do programa minimalista

In this paper I present some evidencie that forces us to conclude that within the Minimalist Program (Chomsky 1993; 1995), Binding Theory (BT) should be computed after LF (Logical Form). I show that derivations leading to structures containing violations of BT-Principles must converge at LF, since less economical alternative derivations respecting those principles are also ungrammatical. Being irrelevant to the notion of convergence, BT must apply after LF. A similar reasoning reveals that the Theta-Criterion should have the status of a bare output condition appling at LF, since less economical derivations are allowed by the computational system to prevent violations of it.