Specificity and selectivity improvement in doping analysis using comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry

Comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry was used for the identification of forty doping agents. The improvement in the specificity was remarkable, allowing the resolution of analytes that could not be done by one-dimensional chromatographic systems. The sensitivity observed for different classes of prohibited substances was clearly below the value required by the World Anti-Doping Agency. In addition time-of-flight mass spectrometry gives full spectrum for all analytes without any interference from the matrix, resulting in selectivity improvements. These results could support the implementation of an exhaustive monitoring approach for hundreds of doping agents in a single injection.

Novas métricas holísticas para avaliação da verdura de reações de síntese em laboratório

New semi-quantitative metrics for simple evaluation of global greenness of chemical reactions used in teaching laboratories, namely, the Green Circle (GC) and Green Matrix (GM), were developed. These metrics globally consider all Twelve Principles of Green Chemistry. To illustrate their construction, the greenness of several syntheses performed in the laboratory under different sets of conditions was assessed. The tools were validated by comparing the results with another metric, the Green Star (GS), developed in our previous study. Results showed these new metrics were useful for the intended purpose, having the advantage of being simpler than the GS.

A pesquisa em Ensino de Química como área estratégica para o desenvolvimento da Química

This paper presents an overview of the development of chemical education as a research area and some of its contributions to society. Although science education is a relatively recent area of research, it went through an expressive development in the last decades. As in the whole world, in Brazil also such development is attested by the expressive number of scientific societies, specialized journals, and meetings with growing attendance in the areas of science education in general and chemical education in particular. Following are the main contributions of research in science education related to chemistry teaching: adoption of teaching-learning principles in chemistry education; contextualization of chemical knowledge; interdisciplinary approach to chemistry teaching; use of the history of science for the definition of contents and for the design of curricula and teaching tools; development of specific disciplines for the initial and in-service training of chemistry teachers; publication of innovative chemistry textbooks by university-based research groups; elaboration of official guidelines for high-school level; and evaluation of chemistry textbooks to be distributed to high-school students by the Brazilian government. In spite of a positive impact of such initiatives, science education in Brazil still faces many problems, as indicated by poor results in international evaluations (such as the Program for International Student Assessment). However, changes in such a scenario depend less on the research in chemical education than on the much-needed governmental initiatives aiming at the improvement of both attractiveness of teaching career and structural conditions of public schools. In conclusion, new government investments in education are necessary for continuing the development of chemistry; moreover, scientific societies and decision makers in educational policies should take into consideration the contributions originated from the chemical education research area.

AVOIDING FIRST-YEAR UNIVERSITY CHEMISTRY TEXTBOOKS’ MISREPRESENTATIONS IN THE TEACHING OF SPONTANEOUS REACTIONS

This paper summarizes the misrepresentations related to Gibbs energy in general chemistry textbooks. These misrepresentations arise from a problem in the terminology textbooks use. Thus, after reviewing the proper definition of each of the terms analyzed, we present two problems to exemplify the correct treatment of the quantities involved, which may help in the discussion and clarification of the misleading conventions and assumptions reported in this study.

ESTRATEGIA DE DOBLE CICLO DE SUPERVISIÓN CLÍNICA PARA LA MEJORA DE LA CALIDAD DOCENTE EN LA UNIVERSIDAD. PUNTO DE VISTA DEL PROFESORADO NOVEL

This work describes a mentorship experience. Mentorship of novice teachers by experienced teachers is an important aspect in training teachers for universities. The strategy followed in this work consisted of a double improvement cycle (or clinical supervision cycle), based on the use of recordings of classes. Each of these cycles included planning, recording, viewing and analysis. Conclusions were reached in a final meeting after video analysis. In order to systematize the viewing, analysis and assessment of the videos, an observation test was employed. Class planning, contents, methodology, and verbal and nonverbal communication skills were evaluated using the test.

INTERACTIONS: DESIGN, IMPLEMENTATION AND EVALUATION OF A COMPUTATIONAL TOOL FOR TEACHING INTERMOLECULAR FORCES IN HIGHER EDUCATION

Intermolecular forces are a useful concept that can explain the attraction between particulate matter as well as numerous phenomena in our lives such as viscosity, solubility, drug interactions, and dyeing of fibers. However, studies show that students have difficulty understanding this important concept, which has led us to develop a free educational software in English and Portuguese. The software can be used interactively by teachers and students, thus facilitating better understanding. Professors and students, both graduate and undergraduate, were questioned about the software quality and its intuitiveness of use, facility of navigation, and pedagogical application using a Likert scale. The results led to the conclusion that the developed computer application can be characterized as an auxiliary tool to assist teachers in their lectures and students in their learning process of intermolecular forces.

AVALIAÇÃO DO USO DE PLANILHAS COMPUTACIONAIS COMO UMA FERRAMENTA DIDÁTICA EM QUÍMICA ANALÍTICA QUALITATIVA

The use of spreadsheet softwares is not widespread in Chemical Education in Brazil as a computational education tool. By its turn the Qualitative Analytical Chemistry is considered a discipline with classical and non-flexible content. Thus in this work the spreadsheet software Excel® was evaluated as a teaching tool in a Qualitative Analytical Chemistry course for calculations of concentrations of the species in equilibrium in solutions of acids. After presenting the theory involved in such calculations the students were invited to elaborate the representation of the distribution of these species in a graphical form, using the spreadsheet software. Then the teaching team evaluated the resulting graphics regarding form and contents. The graphics with conceptual and/or formal errors were returned for correction, revealing significant improvement in the second presentation in all cases. The software showed to be motivating for the content of the discipline, improving the learning interest, while it was possible to prove that even in classical disciplines it is possible to introduce new technologies to help the teaching process.

Active teaching-learning methodologies: medical students' views of problem-based learning

The prevailing undergraduate medical training process still favors disconnection and professional distancing from social needs. The Brazilian Ministries of Education and Health, through the National Curriculum Guidelines, the Incentives Program for Changes in the Medical Curriculum (PROMED), and the National Program for Reorientation of Professional Training in Health (PRO-SAÚDE), promoted the stimulus for an effective connection between medical institutions and the Unified National Health System (SUS). In accordance to the new paradigm for medical training, the Centro Universitário Serra dos Órgãos (UNIFESO) established a teaching plan in 2005 using active methodologies, specifically problem-based learning (PBL). Research was conducted through semi-structured interviews with third-year undergraduate students at the UNIFESO Medical School. The results were categorized as proposed by Bardin's thematic analysis, with the purpose of verifying the students' impressions of the new curriculum. Active methodologies proved to be well-accepted by students, who defined them as exciting and inclusive of theory and practice in medical education.

Learning through role-playing games: an approach for active learning and teaching

This study evaluates the use of role-playing games (RPGs) as a methodological approach for teaching cellular biology, assessing student satisfaction, learning outcomes, and retention of acquired knowledge. First-year undergraduate medical students at two Brazilian public universities attended either an RPG-based class (RPG group) or a lecture (lecture-based group) on topics related to cellular biology. Pre- and post-RPG-based class questionnaires were compared to scores in regular exams and in an unannounced test one year later to assess students' attitudes and learning. From the 230 students that attended the RPG classes, 78.4% responded that the RPG-based classes were an effective tool for learning; 55.4% thought that such classes were better than lectures but did not replace them; and 81% responded that they would use this method. The lecture-based group achieved a higher grade in 1 of 14 regular exam questions. In the medium-term evaluation (one year later), the RPG group scored higher in 2 of 12 questions. RPG classes are thus quantitatively as effective as formal lectures, are well accepted by students, and may serve as educational tools, giving students the chance to learn actively and potentially retain the acquired knowledge more efficiently.

Profile of hip arthroplasty patients in a teaching hospital

OBJECTIVE: to characterize the epidemiological profile of patients undergoing hip replacement, primary or revisional. METHODS: we conducted a retrospective, descriptive study, including hip arthroplasties performed from January 2009 to June 2012 in a Belo Horizonte teaching hospital, Minas Gerais State - MG, Brazil. Data were analyzed using descriptive statistics. RESULTS: orthopedic procedures represented 45% of the operations at the hospital in the period, 1.4% hip arthroplasties. There were 125 hip replacements, 85 total, 27 partial and 13 reviews. Among the patients, 40% were male and 60% were female. Age ranged between 20 and 102 years, mean and median of 73 and 76 years, respectively. The most frequent diagnosis (82%) was femoral neck fracture by low-energy trauma caused by falling form standing position. In 13 revision operations, 12 required removal of the prosthesis. The infectious complication led to revision in 54% of the time, followed by dislocation (15%), peri-prosthetic fracture (15%) and aseptic loosening (15%). The infection etiologic agent was identified in 43% of occasions. The average length of the prosthesis to a revision operation was eight months. CONCLUSION: patients undergoing hip arthroplasty are elderly, with femoral neck fracture caused by falling form standing position, affecting more women. The incidence of hip prosthesis loosening was 10%. The main cause of the infection was loosening. The incidence of revisional hip arthroplasty was 10% and the incidence of hospital mortality in patients undergoing hip arthroplasty was 7.2%.

Comparison between open and laparoscopic elective cholecystectomy in elderly, in a teaching hospital

Objective: to analyze the differences in mortality rates, length of hospital stay, time of surgery and the conversion rate between elective open cholecystectomies (OC) and laparoscopic ones (LC) in elderly patients. Methods : we evaluated medical records of patients 65 years of age or older undergoing open or laparoscopic cholecystectomy at the Hospital Regional de Mato Grosso do Sul between January 2008 and December 2011. We excluded individuals operated in non-elective scenarios or who underwent intraoperative cholangiography. Results : we studied 113 patients, of whom 38.1% were submitted to the OC and 61.9%, to LC. Women accounted for 69% of patients and men, for 31%. The conversion rate was 2.9%. The mean age and duration of the procudure was 70.1 and 84 minutes, respectively, with no significant difference between OC and LC. Patients undergoing LC had shorter hospital stays (2.01 versus 2.95 days, p=0.0001). We identified operative complications in sixpatients (14%) after OC and in nine (12%) after LC, with no statistical difference. Conclusion : there was no difference in morbidity and mortality when comparing OC with LC. The laparoscopic approach led to shorter hospital stay. Operative time did not differ between the two access routes. The conversion rate was similar to other studies.

Teaching project: a low-cost swine model for chest tube insertion training

Objective: to describe and evaluate the acceptance of a low-cost chest tube insertion porcine model in a medical education project in the southwest of Paraná, Brazil. Methods: we developed a low-cost and low technology porcine model for teaching chest tube insertion and used it in a teaching project. Medical trainees - students and residents - received theoretical instructions about the procedure and performed thoracic drainage in this porcine model. After performing the procedure, the participants filled a feedback questionnaire about the proposed experimental model. This study presents the model and analyzes the questionnaire responses. Results: seventy-nine medical trainees used and evaluated the model. The anatomical correlation between the porcine model and human anatomy was considered high and averaged 8.1±1.0 among trainees. All study participants approved the low-cost porcine model for chest tube insertion. Conclusion: the presented low-cost porcine model for chest tube insertion training was feasible and had good acceptability among trainees. This model has potential use as a teaching tool in medical education.

Modeling, optimizing and simulating robot calibration with accuracy improvement

This work describes techniques for modeling, optimizing and simulating calibration processes of robots using off-line programming. The identification of geometric parameters of the nominal kinematic model is optimized using techniques of numerical optimization of the mathematical model. The simulation of the actual robot and the measurement system is achieved by introducing random errors representing their physical behavior and its statistical repeatability. An evaluation of the corrected nominal kinematic model brings about a clear perception of the influence of distinct variables involved in the process for a suitable planning, and indicates a considerable accuracy improvement when the optimized model is compared to the non-optimized one.

Recuperation and improvement of chromosome preparations stained with silver nitrate

Both periodic acid and photographic reagents have been used to remove the silver nitrate residues from cytological preparations. We used potassium ferricyanide to remove AgNO3 salts in cases of excessive chromosome impregnation. This method produced partial decolorization, with contrast enhancement. Counterstaining with Giemsa also promoted a better contrast between chromosome arms and NORs, which were preserved and retained a dark color. Application of this procedure to chromosome preparations treated sequentially for CBG banding/AgNO3 staining promoted complete decolorization of C+ regions, leading to "reverse" C-banding, generally with high contrast.