Ressonância magnética da próstata: uma visão geral para o radiologista

O adenocarcinoma prostático é o segundo tumor em incidência e mortalidade dentre as neoplasias malignas masculinas. Para adequada programação terapêutica é importante a distinção entre tumores confinados à próstata e aqueles com extensão extraprostática. Diferentes estudos têm demonstrado que a ressonância magnética da próstata com bobina endorretal auxilia no estadiamento local destes pacientes. Este artigo apresenta informações sobre a anatomia prostática, o aspecto tumoral à ressonância magnética, sinais de extensão tumoral extraprostática e invasão de vesículas seminais, sugestões de protocolo, princípios gerais e importância da espectroscopia de prótons, do estudo perfusional e da difusão, indicações da ressonância magnética na investigação de recidiva pós-operatória e pós-radioterapia, seu papel na detecção de lesões suspeitas em pacientes com suspeita clínico-laboratorial de adenocarcinoma prostático, além de apresentar os diagnósticos diferenciais e limitações do método.

Os três princípios e as doenças: a visão de dois filósofos químicos

Paracelsus (1493 - 1541) developed a theory about three principles (sulphur, mercury, and salt) that would constitute matter, and whose mutual interactions within man's body could cause diseases. This paper discusses the influence of this theory on the work of two chemical philosophers. Oswald Crollius (1560 - 1609) considered that the conceptions of matter and disease were strongly related because of the macro - microcosm analogy, and classified diseases in sulphurean, mercurial and saline. On the other hand, J. B. Van Helmont (1579 - 1644) stated that sulphur, mercury, and salt were not true principles, and that every disease would have a specific origin. Instead of the principles, Van Helmont put the Archeus at the center of both his medical and matter theories.

O impacto do PADCT na química brasileira: uma visão acadêmica

An appraisal has been conducted of the impact PADCT (Support Program for Scientific and Technological Development) has caused on brazilian Chemistry and Chemical Engineering over a ten years period (1985-1995). During this time PADCT invested US$ 87.5 million dollars to support both scientific and technolgical development of chemistry. The main results, from an academic point of view, has been the strengthening of support services for academic research, including libraries and analytical facilities, and a consequent increase of the number and quality of human resources trained at the graduate level as well as a significant increase in the number of scientific publications.

As primeiras vinte reuniões anuais da SBQ: uma visão da evolução da química no Brasil

An analysis of the different activities carried out during the first twenty annual meetings (1978-1997) of the Brazilian Chemical Society (SBQ) is presented. The number of papers in the abstract book increased from around 300 in the biennium 78/79 to around 1230 in 96/97. The papers contained in the different sections of the abstract book in the 1st (1978), 10th (1987) and 19th (1996) annual meetings were grouped according to the regions of Brazil the authors' institutions were from, or abroad, and also considering whether the paper came from one institution or was a collaboration between two or more institutions. The relative contribution of the southeastern and northern regions decreased from 77% and 3.0% of the total in 1978 to 63% and 1.2% in 1996, respectively, while those of the northeastern, southern and midwestern regions increased from 12%, 4.8% and 0.6% to 15%, 13%, and 2.6%, respectively; the relative contribution of institutions from abroad also increased from 2.4% to 4.0%. Chemistry of Natural Products and Organic Chemistry decreased their relative contribution from around 55% in 1978 to around 28% in 1996, an evolution towards a more balanced development of the different areas of chemistry in Brazil.

La formación de habilidades en Química General en la perspectiva de la teoría de P. Ya. Galperin, como actividad de contrucción de conocimientos

Thir paper presents the results of a pedagogical experiment conducted with chemistry students of the mechanical engineering curriculum. The aim of the experiment was to study the development of the a general ability for the study program as a process of knowledge construction based on the theory of assimilation of P. Ya. Galperin.

Uma visão das tendências e perspectivas em eletrocromismo: a busca de novos materiais e desenhos mais simples

Some aspects of electrochromism phenomena are presented in this review paper. A deep literature revision about the subject dealing with materials and device configurations developed in the last years, is presented. Great efforts of the scientific community have been done in this field. On the other hand, new electrochomic devices based on reversible deposition of metals are specially emphasized here. These devices present many advantages such as simple operation and construction and they have also shown high cycling rates. These factors make them suitable for application in display industry. In this way, many concepts used in the developement of electrodeposition baths are very useful for the improvement of these new devices; specially, all knowledge about the use of additives for modifying films microstructure and morfology.

Espectrometria de absorção atômica com atomização eletrotérmica em filamento de tungstênio: uma re-visão crítica

In this review it is presented some aspects of electrothermal atomic absorption spectrometry with tungsten coil (ETAW-AAS) since its beginning until the present days as well as the perspectives for this technique. Some aspects concerning its development and theoretical concepts are discussed. The analytical figures of merit such as limit of detection (LD), characteristic mass (m0), relative standard deviation (RSD), accuracy and precision are evaluated, compared and discussed considering published works. It is also evaluated its advantages, applications, limitations and instrumental development. The use of diode laser as radiation source and its perspectives to ETAW are also discussed.

Novas estratégias terapêuticas para o tratamento da depressão: uma visão da química medicinal

Depression is a widespread humor disturbance promoted mainly by depletion of biogenic neurotransmitter amines involved in the CNS synapses. Effective drug treatments for depression have been available for more than forty years. Despite its remarkable structural diversity, this paper discuss under the medicinal chemistry point of view, all different classes of "monoamine based" antidepressant drugs, emphasizing the rational design, structure-activity relationships (SAR), biotransformation and physico-chemical properties related with antidepressant activity and molecular mechanism of action.

Uma visão da química bioinorgânica medicinal

Metals play a vital role in human and plant physiology and important research is directed towards exploring the interrelated mechanisms that govern their interactions with biomolecules. Bioinorganic medicinal chemistry studies the functions, processing, storage and applications of metal ions and their complexes in biological systems. This paper presents a brief discussion about on interactions of metals with biomolecules that determine their intracellular accumulation, where metal ions may fulfill essential functions in cellular metabolism or, in certain cases, exert toxic effects towards cells.

A gestão de resíduos de laboratório na visão de alunos de um curso de graduação de quimica e áreas afins

This work presents the students´ profile before and after working in the course "Laboratory Chemical Waste Treatment" in the last ten years. The structure of the course is also described. Although students have shown an increasing previous experience on waste management, many fundamental aspects are missing, especially knowledge on the directives focusing environmental aspects. Visits to industrial plants are also essential to better understand the impact of wastes in environment. Most students nowadays consider waste management as an essential part of their professional formation. A good waste management program must consider several topics of extreme relevance.

Biodiesel: visão crítica do status atual e perspectivas na academia e na indústria

This article presents a bibliographic review of research carried out on different alternative processes for biodiesel production. The supercritical and subcritical (non catalytic) reaction conditions, the use of solid basic, solid acid and other heterogeneous catalysts, including the use of immobilized enzymes and whole-cell catalysts are also critically compared with the traditional homogeneous alkaline or acid catalysts that are common on industrial applications. Advantages and limitations of all these processes for the transference from the laboratory to the industry are discussed. A correlation of the chemical composition with the quality parameters of the produced biodiesel is done with aim to stablish adequate procedures for the right selection of the raw-material. Castor bean oil is used as an example of inappropriate oil in order to produce a B100 that fulfill all the international physico-chemical quality standards. In this article are presented research results to adequate the values of viscosity, density and iodine number of the castor and soybean biodiesel to the international standard limits by means blending these both biodiesels at the right ratio.

Cadeia do biodiesel da bancada à indústria: uma visão geral com prospecção de tarefas e oportunidades para P&D&I

Contextualized overview of the Biodiesel Production Chain, from the lab bench to the industry, with critical evaluation of state-of-art and technological development through scientific articles and patents, focusing on feedstock, reaction/production, first and second generation processes, specification and quality, transport, storage, co-products (effluents and sub-products), and emissions. Challenges are identified and solutions are proposed based on the Brazilian feedstock, edaphoclimatic conditions, process monitoring in remote regions, state policy, and environment preservation, among others. Forecasts are made based on the technology assessment, identifying future trends and opportunities for R&D&I.

Uma visão sobre a estrutura, composição e biodegradação da madeira

Wood is the main raw material used in the pulp and paper industry. It is a material that presents heterogeneous structure and complex composition, which results in a relatively resistant material to the biodegradation process. In the present review, we attempted to summarize the structural characteristics of wood and describe the chemical nature of its major components to, afterwards, comment about its biodegradation. The role of the enzyme manganese peroxidase in the lignin degradation by a selective white-rot fungus, Ceriporiopsis subvermispora, was highlighted.

Tetraciclinas e glicilciclinas: uma visão geral

Tetracyclines exhibits activity to a broad range of Gram-negative and Gram-positive bacteria and this fact allied to the low toxicity, low cost, and the advantage of administration by oral route led to their indiscriminate use, which caused the appearance of bacterial resistance to these agents, wich has restricted its clinical utility, though new applications have emerged. On the other hand, the glycylcyclines, semi-synthetic products are similar to tetracyclines, which are active against many bacteria resistant to tetracycline and other classes of antibiotics. The purpose of this paper is to give an overview of this important class of antibiotics focusing on its coordination chemistry and possible applications.