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.

Processo químico industrial de extração de óleo vegetal: um experimento de química geral

In this study we describe an experimental procedure based on a chemical industrial process of soya-bean oil extraction applied in general chemistry for undergraduate students. The experiment was planned according to the Science, Technology and Society (STS) approach to teach basic chemical concepts and provide grounding in the management of environmental care. The use of real life chemistry problems seems to salient the relevance of chemistry to our students and enhances their motivation to learn both the practical and theoretical components of the discipline.

Os trinta anos da disciplina "Química Geral" oferecida aos alunos ingressantes no curso de graduação do Instituto de Química da Unicamp

An overview of the last thirty years of the General Chemistry Course applied to the freshmen in our Institute is presented. All the changes introduced in the course since the first time it was offered up to our days are described and a discussion of the program now developed is given.

Um experimento com propostas múltiplas para um laboratório de química geral

This article suggests a sequence of experiments on the preparation, analysis and some photochemical aspects of potassium tris (oxalato) ferrate(III) trihydrate. The sequence of experiments could be carried out in four or five 4-hour laboratory periods. The new part of this article is related to the kinetics studies involving the ambient illumination as well as the use of the cellophane paper of different colors as light filters. The aspects such as quantum yield, light absorption and photochemical reactions are explored in order to illustrate the relationships between the exposure time, light intensity and wavelength range on the photochemical reactions.

As percepções dos professores de química geral sobre a seleção e a organização conceitual em sua disciplina

The teaching of general chemistry involves both the choice and the organization of its concepts. Although College Teachers make their choices, frequently the text books play an important role in this selection. In the present project we intend to show what are Teachers' perceptions of conceptual organization and selection as well as their perceptions of how to teach general chemistry. This demonstration is carried out through the use of metaphors from new information technologies.

Química geral experimental: uma nova abordagem didática

This essay describes a new didactic approach, in according with the national curriculum guidelines for chemistry undergraduate courses in Brazil, employed during the one-semester course "Experimental General Chemistry" for chemistry undergraduate students at the Federal University of Piauí. The new approach has positively helped student's training by improving their reading skills and their understanding of scientific reports, by developing the use of electronic tools to search and to recover the required knowledge for their learning activities, and by improving their skills of understanding published texts and dealing with digital sources. At the same time the students are strongly stimulated to enter the research program for undergraduate students available at the University.

Esquema geral para elucidação de substâncias orgânicas usando métodos espectroscópico e espectrométrico

This work describes a systematic method to be applied in undergraduate courses of organic chemistry, correlating infrared spectra, hydrogen and carbon-13 nuclear magnetic resonance, and mass spectra. To this end, a scheme and a table were developed to conduct the elucidation of the structure of organic compounds initially using infrared spectra. Interpretation of hydrogen and carbon-13 nuclear magnetic resonance spectra and of mass spectra is used to confirm the proposed structure.

Síntese de biodiesel: uma proposta contextualizada de experimento para laboratório de química geral

The contextualized understanding of concepts in Chemistry by students from other areas is a challenging task. In this experiment, the synthesis of biodiesel is done by base catalyzed transesterification of refined soy oil with methanol at room temperature and common glassware found in any chemistry laboratory. The proposal permits introducing several concepts, such as that of emulsion, viscosity and catalysis to illustrate an activity based on an actual problem. In this didactic approach, some common problems of biodiesel production, such as soap formation and phase separation, are introduced into the procedure in order to raise questions and motivate the students to participate in the experimental work and stimulate reflections about critical aspects of biodiesel production. This experiment was carried out in the first semester of 2006, in experimental general chemistry taken by physics and agricultural, civil and chemical engineering students of UNICAMP.

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.

Remoção de Pb2+ e Cr3+ em solução por zeólitas naturais associadas a rochas eruptivas da formação serra geral, bacia sedimentar do Paraná

The capacity of natural zeolites and its host rock (dacite) to remove Pb2+ and Cr3+ from aqueous solutions has been investigated. Results showed that both samples prefer to remove Pb2+ instead of Cr3+. Almost 100% of Pb2+ was removed from solutions with concentration until 50 mg L-1 and 100 mg L-1 of this metal, respectively by dacite and zeolite. The equilibrium of metals adsorption process was reached during the first 30 min by both materials. Na+ can be used to recover Pb2+, but not to remove Cr3+ from the treated samples. The Sips model showed a good fit for experimental data of this study.

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.

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.

Cromatografia gasosa ultrarrápida: uma visão geral sobre parâmetros, instrumentação e aplicações

Since the introduction of GC there has been an ongoing interest in reducing time of analysis resulting in new terms and definitions such as ultra fast gas chromatography (UF-GC). One of the most used definitions describes UF-GC as a technique that combines the employment of short narrow bore column with very fast temperature programming rates producing chromatographic peaks in the range of 50 ms and allowing separations times in 1-2 min or less. This paper summarizes the analytical approaches, the main parameters involved and the instrumentation towards UF-GC.

Montagem de uma disciplina experimental: contribuição para a química geral

The purpose of this paper is to present a classification criterion for general chemistry experiments departing from a survey of 35 years of the experimental general chemistry discipline at the Chemistry Institute - UNICAMP. It is shown that by considering the most remarkable characteristics of an experiment and classifying it under Conceptual, Fundamental, Methodological or Quantitative criterion, teachers could better develop the discipline plan and prevent a subject superposition. Taking into account the system Fe3+/SCN- , the article also exemplify how is possible to modify an experimental approach and to conceive other procedures with different didactic purposes.

Atribuição absoluta e geral de isômeros constitucionais por espectrometria de massas: o caso das metilpiperidinas

An absolute method is described via mass spectrometry (MS) for the structural assignment of isomers within the class of methylpiperidines. The method explores both the unimolecular and bimolecular gas phase behavior of structurally diagnostic fragment ions (SDFI). For the methylpiperidnes, the isomeric 2-methyl, 3-methyl and 4-methyl 2-azabutadienyl cations are found to function as SDFI. These fragment ions are expected to be formed from all members within the class, to be stable and to retain the structural information of the precursor molecule, and to not interconvert into one another. To characterize these SDFI, both the collision induced dissociation (CID) in argon and bimolecular ion/molecule chemistry with ethyl vinyl ether were compared.