Study of the comprehension of the scientific method by members of a university health research laboratory

In Brazil, scientific research is carried out mainly at universities, where professors coordinate research projects with the active participation of undergraduate and graduate students. However, there is no formal program for the teaching/learning of the scientific method. The objective of the present study was to evaluate the comprehension of the scientific method by students of health sciences who participate in scientific projects in an academic research laboratory. An observational descriptive cross-sectional study was conducted using Edgar Morin complexity as theoretical reference. In a semi-structured interview, students were asked to solve an abstract logical puzzle - TanGram. The collected data were analyzed using the hermeneutic-dialectic analysis method proposed by Minayo and discussed in terms of the theoretical reference of complexity. The students’ concept of the scientific method is limited to participation in projects, stressing the execution of practical procedures as opposed to scientific thinking. The solving of the TanGram puzzle revealed that the students had difficulties in understanding questions and activities focused on subjects and their processes. Objective answers, even when dealing with personal issues, were also reflected on the students’ opinions about the characteristics of a successful researcher. Students’ difficulties concerning these issues may affect their scientific performance and result in poorly designed experiments. This is a preliminary study that should be extended to other centers of scientific research.

Laboratory indicators for monitoring HIV disease

Immunological monitoring of disease progression following HIV infection and seroconversion illness, latency and AIDS, not only helps in the basic investigation of the natural history of the viral infection in man, but also can assist in prognosis and treatment of AIDS-defining illnesses. However, outside clinical trials, these tests should be selected and used in clinical practice only if they are validated as relevant and effective. The absolute CD4+ T-helper lymphocyte count, measured by flow cytometry, has emerged as the best available investigation, but needs care in sampling due to diurnal and circadian rhythms, effects of age, pregnancy, therapy, intercurrent infections and technique. Sampling should provide a baseline and trends - monthly intervals initially, then quarterly in uncomplicated cases. Thresholds may be given for counts (e.g. 200/µl) below which prophylaxis against pneumocystis pneumonia should be administered, and repeating persistently low counts (e.g. below 50/µl) is seldom helpful in practice. Serum levels of beta-2 microglobulin, neopterin and immunoglobulins rarely add information. Physicians and laboratories should have testing guidelines based on clinical audit of best practice, based in turn on scientific understanding of the immunological processes involved.

Determinacion de la configuracion E-Z de los acidos Fumarico y Maleico. Un experimento orientado a incentivar el desarrollo de la investigacion cientifica en alumnos de Pregrado

In this work we intend to eliminate the idea that laboratory exercises seem like cookbooks. That is, exercises shall be presented as a problematic situation. Based on observation and experimentation, the students should determine the E-Z configuration of maleic and fumaric acids. The basis of this laboratory exercise is the acid-catalyzed isomerization of maleic acid to fumaric acid. Students are given the starting material, reagents and the experimental procedure. They are told that the starting material is a dicarboxylic acid containing a C=C double bond of formula C4H4O4. Students determine melting points, solubilities, acidity and chromatographic patterns for both the starting material and the product, so that a configuration of each acid can be proposed. This type of experiment yields excellent results, because the students are left to deduce that maleic acid is less stable than fumaric acid. Additionally, they conclude that maleic acid is the "Z" isomer and fumaric acid is the "E" isomer. Finally, this laboratory exercise allows the students to develop simultaneously their critical-thinking skills with the respective laboratory techniques and not to see chemistry as recipes to be followed.

El aprendizaje basado en problemas como estrategia para el cambio metodológico en los trabajos de laboratorio

The Problem Based Learning (PBL) can be used as a strategy for methodological change in conventional learning environments. In this paper, the integration of laboratory work in PBL grounded activities during an introductory organic chemistry course is described. The most decisive issues of their implementation are discussed. The results show how this methodology favours the laboratory work contextualization in subject-matter and promotes the Science-Technology-Society-Environment relationships. Besides, it contributes to competence development like planning and organization skills, information search and selection, cooperative work, etc., the same way as the tutorial action improvement.

Escrita científica de alunos de graduação em química: análise de relatórios de laboratório

The purpose of this study was to analyze written arguments found within laboratory reports by undergraduate students in a practical inorganic chemistry course. The quality of students' argumentation was analyzed based on the argumentation model developed by Kelly and Takao. Students presented scientific arguments grounded in data and building toward theoretical assertions. This indicates that students have some understanding of the rhetorical power of data in their explanations. The findings of this study also support the idea that Kelly and Takao's model is effective in other disciplines and in other rhetorical tasks distinct from those originally analyzed by them in their domain of oceanography.

ENZYMATIC RESOLUTION OF ANTIDEPRESSANT DRUG PRECURSORS IN AN UNDERGRADUATE LABORATORY

The use of biocatalysts in synthetic chemistry is a conventional methodology for preparing enantiomerically enriched compounds. Despite this fact, the number of experiments in chemical teaching laboratories that demonstrate the potential of enzymes in synthetic organic chemistry is limited. We describe a laboratory experiment in which students synthesized a chiral secondary alcohol that can be used in the preparation of antidepressant drugs. This experiment was conducted by individual students as part of a Drug Synthesis course held at the Pharmacy Faculty, Lisbon University. This laboratory experiment requires six laboratory periods, each lasting four hours. During the first four laboratory periods, students synthesized and characterized a racemic ester using nuclear magnetic resonance spectroscopy and gas chromatography. During the last two laboratory periods, they performed enzymatic hydrolysis resolution of the racemic ester using Candida antarctica lipase B to yield enantiomerically enriched secondary alcohol. Students successfully prepared the racemic ester with a 70%-81% overall yield in three steps. The enzymatic hydrolysis afforded (R)- secondary alcohol with good enantioselectivity (90%-95%) and reasonable yields (10%-19%). In these experiments, students were exposed to theoretical and practical concepts of aromatic acylation, ketone reduction, esterification, and enzymatic hydrolysis.