Desafios da escola atual: a educação pelo trabalho

This work aims at investigating and proposing strategies to improve the comprehension of Chemistry concepts by high school students. One of these strategies consists in workshops that emphasize the notion of work as a general educational principle, in the perspective of polytechnic education. Interviews (pre and post-workshops) were used to evaluate the results. In post-workshop interviews, a significant incorporation of scientific concepts was observed, as well as a considerable improvement in the interpretation of experiments.

Preparação de derivados do lapachol em meio ácido e em meio básico: uma proposta de experimentos para a disciplina de Química Orgânica Experimental

In this educational paper we describe the extraction of lapachol from its natural source according to acid-base concepts in organic chemistry and the use of its derivatives β-lapachone and hydroxy-hydrolapachol to exemplify intramolecular cyclization, carbocation stability, Michael addition reaction and chromatography. The experiments were performed during three different undergraduate organic chemistry laboratory classes using low cost material, while avoiding color reagents for TLC visualization, as well as small-scale column chromatography to isolate the mixture of lapachol and β-lapachone.

Optimization and practical implementation of ultrafast 2D NMR experiments

Ultrafast 2D NMR is a powerful methodology that allows recording of a 2D NMR spectrum in a fraction of second. However, due to the numerous non-conventional parameters involved in this methodology its implementation is no trivial task. Here, an optimized experimental protocol is carefully described to ensure efficient implementation of ultrafast NMR. The ultrafast spectra resulting from this implementation are presented based on the example of two widely used 2D NMR experiments, COSY and HSQC, obtained in 0.2 s and 41 s, respectively.

Frequency of fear of needles and impact of a multidisciplinary educational approach towards pregnant women with diabetes

PURPOSE: To evaluate the frequency of fear of needles and the impact of a multidisciplinary educational program in women with pre-gestational and gestational diabetes taking insulin during pregnancy. METHODS: The short Diabetes Fear of Injecting and Self-testing Questionnaire (D-FISQ), composed by two subscales that access fear of self injection (FSI) and fear of self testing (FST), was administered twice during pregnancy to 65 pregnant women with pre-gestational and gestational diabetes: at the first endocrine consult and within the last two weeks of pregnancy or postpartum. An organized multidisciplinary program provided diabetes education during pregnancy. Statistical analysis was carried out by Wilcoxon and McNemar tests and Spearman correlation. A p<0.05 was considered to be significant. RESULTS: Data from the short D-FISQ questionnaire shows that 43.1% of pregnant women were afraid of needles in the first evaluation. There was a significant reduction in scores for FSI and FST subscales between the first and second assessments (first FSI 38.5% compared with second 12.7%, p=0.001; first FST 27.7% compared with second FST 14.3%, p=0.012). CONCLUSIONS: The fear of needles is common in pregnant women on insulin therapy and an organized multidisciplinary educational diabetes program applied during pregnancy reduces scores of such fear.

Looking for the GAP effect in manual responses and the role of contextual influences in reaction time experiments

When the offset of a visual stimulus (GAP condition) precedes the onset of a target, saccadic reaction times are reduced in relation to the condition with no offset (overlap condition) - the GAP effect. However, the existence of the GAP effect for manual responses is still controversial. In two experiments using both simple (Experiment 1, N = 18) and choice key-press procedures (Experiment 2, N = 12), we looked for the GAP effect in manual responses and investigated possible contextual influences on it. Participants were asked to respond to the imperative stimulus that would occur under different experimental contexts, created by varying the array of warning-stimulus intervals (0, 300 and 1000 ms) and conditions (GAP and overlap): i) intervals and conditions were randomized throughout the experiment; ii) conditions were run in different blocks and intervals were randomized; iii) intervals were run in different blocks and conditions were randomized. Our data showed that no GAP effect was obtained for any manipulation. The predictability of stimulus occurrence produced the strongest influence on response latencies. In Experiment 1, simple manual responses were shorter when the intervals were blocked (247 ms, P < 0.001) in relation to the other two contexts (274 and 279 ms). Despite the use of choice key-press procedures, Experiment 2 produced a similar pattern of results. A discussion addressing the critical conditions to obtain the GAP effect for distinct motor responses is presented. In short, our data stress the relevance of the temporal allocation of attention for behavioral performance.

The terrestrial Gastropoda Megalobulimus abbreviatus as a useful model for nociceptive experiments: effects of morphine and naloxone on thermal avoidance behavior

We describe the behavior of the snail Megalobulimus abbreviatus upon receiving thermal stimuli and the effects of pretreatment with morphine and naloxone on behavior after a thermal stimulus, in order to establish a useful model for nociceptive experiments. Snails submitted to non-functional (22ºC) and non-thermal hot-plate stress (30ºC) only displayed exploratory behavior. However, the animals submitted to a thermal stimulus (50ºC) displayed biphasic avoidance behavior. Latency was measured from the time the animal was placed on the hot plate to the time when the animal lifted the head-foot complex 1 cm from the substrate, indicating aversive thermal behavior. Other animals were pretreated with morphine (5, 10, 20 mg/kg) or naloxone (2.5, 5.0, 7.5 mg/kg) 15 min prior to receiving a thermal stimulus (50ºC; N = 9 in each group). The results (means ± SD) showed an extremely significant difference in response latency between the group treated with 20 mg/kg morphine (63.18 ± 14.47 s) and the other experimental groups (P < 0.001). With 2.5 mg/kg (16.26 ± 3.19 s), 5.0 mg/kg (11.53 ± 1.64 s) and 7.5 mg/kg naloxone (7.38 ± 1.6 s), there was a significant, not dose-dependent decrease in latency compared to the control (33.44 ± 8.53 s) and saline groups (29.1 ± 9.91 s). No statistically significant difference was found between the naloxone-treated groups. With naloxone plus morphine, there was a significant decrease in latency when compared to all other groups (minimum 64% in the saline group and maximum 83.2% decrease in the morphine group). These results provide evidence of the involvement of endogenous opioid peptides in the control of thermal withdrawal behavior in this snail, and reveal a stereotyped and reproducible avoidance behavior for this snail species, which could be studied in other pharmacological and neurophysiological studies.

Prevalence of metabolic syndrome and its association with educational inequalities among Brazilian adults: a population-based study

The present study estimated the prevalence of metabolic syndrome (MS) according to the criteria established by the National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATPIII) and the International Diabetes Federation (IDF) and analyzed the contribution of social factors in an adult urban population in the Southeastern region of Brazil. The sample plan was based on multistage probability sampling according to family head income and educational level. A random sample of 1116 subjects aged 30 to 79 years was studied. Participants answered a questionnaire about socio-demographic variables and medical history. Fasting capillary glucose (FCG), total cholesterol, high-density lipoprotein cholesterol (HDL-C), and triglycerides were determined and all non-diabetic subjects were submitted to the 75-g oral glucose tolerance test. Body mass index (BMI, kg/m²), waist circumference and blood pressure (BP) were determined. Age- and gender-adjusted prevalence of MS was 35.9 and 43.2% according to NCEP-ATPIII and IDF criteria, respectively. Substantial agreement was found between NCEP-ATPIII and IDF definitions. Low HDL-C levels and high BP were the most prevalent MS components according to NCEP-ATPIII criteria (76.3 and 59.2%, respectively). Considering the diagnostic criteria adopted, 13.5% of the subjects had diabetes and 9.7% had FCG ≥100 mg/dL. MS prevalence was significantly associated with age, skin color, BMI, and educational level. This cross-sectional population-based study in the Southeastern region of Brazil indicates that MS is highly prevalent and associated with an important social indicator, i.e., educational level. This result suggests that in developing countries health policy planning to reduce the risk of MS, in particular, should consider improvement in education.