As atividades de demonstração e a teoria de Vigotski: um motor elétrico de fácil construção e de baixo custo

The experimental demonstration is one of the traditional activities used in the ambit of the Science teaching and of the scientific divulgation. However, this activity has not been fully explored yet in the classroom, because teachers have faced considerable difficulties due to the lack of demonstration equipment. In this work we present the explanation of an easy and low-cost assembly of an electric motor, to be used in Physics classes in High School. In addition, we employed Vigotski’s theory to guide this experimental activity in the classroom.

Abordagem experimental da força de atrito em aulas de Física do Ensino Médio

In this paper we propose and describe the performance of an experimental activity to address the concept of friction in High School Physics practical classes. We use a low-cost and simple construction device that enables the determination of the coefficient of static friction between two materials through three different procedures. The results were coherent, with small percentage deviation, which gives reliability to the activity and can stimulate discussions in class. The activity also allows greater contextualization of concepts that are usually discussed only theoretically, requiring a higher abstraction level of the students. This can stimulate discussions and greater interaction between teacher and students.

Avaliação de monitorias realizadas em um centro de ciências

In this paper we investigate the social interaction established between monitors and student-visitors to a science museum in terms of knowledge mobilized by the explanation about principle operating of Van De Graff Generator. Our research was conducted at a university public that maintains a Center of Sciences and the data were collected through recording video and audio of the dialogues established around a demonstration experiment. Data analysis is established around the conceptual correctness of the explanations made by the monitors. We also conducted a structured interview from a single question: what is the main difficulty faced in planning and conducting his presentation at the Science Center? The results show that the monitors were not able to exceed the process description of the operation of the experimental equipment, not being able to establish an interaction that fosters discussions of scientific concepts with visitors. Our research also found that, although the university maintained a Sciences Center, not there is a link between teacher training and activities in non-formal settings.

Hip fracture in a developing country: a picture in need of change

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A utilização das tecnologias nos processos de recrutamento e seleção de pessoas: análises, desafios e tendências

Pós-graduação em Desenvolvimento Humano e Tecnologias - IBRC

Remoção de elementos potencialmente tóxicos em resíduo sólido da indústria canavieira para utilização como condicionador de solo na agricultura

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Revised Diagnostic Criteria for Vogt-Koyanagi-Harada Disease: Considerations on the Different Disease Categories

PURPOSE: To evalulate the applicability of the Revised Diagnostic Criteria for Vogt-Koyanagi-Harada (VKH) disease to Brazilian patients and to verify the association between different disease categories, clinical parameters, and the presence of HLA-DRB1*0405. DESIGN: A retrospective observational case series. METHODS: Medical charts of 67 patients (10 to 64 years in age; 12 men and 55 women), from the Uveitis Service, Hospital das Clinicas, University of Sao Paulo School of Medicine (HCFMUSP), Sao Paulo, Brazil were reviewed. Patients, previously diagnosed with VKH disease using criteria proposed by the American Uveitis Society, underwent retrospective classification based on the Revised Diagnostic Criteria. The degree of concordance was assessed. At presentation, 46 patients (69%) were in the early phase. In this group, the mean time from disease onset to treatment was 15 days (range, one to 30 days). Forty-eight patients (72%) were typed for HLA-DRB1*0405 by polymerase chain reaction-sequence specific primer and polymerase chain reaction,sequence, specific oligonucleotides primer. Disease categories, phase at initial presentation, and ocular complications were analyzed. RESULTS: There was a 100% of concordance between the two criteria. Disease was classified as complete in 10 patients (15%), incomplete in 37 patients (55%), and probable in 20 patients (30%). In each group, respectively, 90%, 76%, and 45% were in the early phase at presentation (P = .017). There was no association between disease categories, the presence of HLA-DRB1*0405, and clinical parameters. CONCLUSION. The Revised Diagnostic Criteria proved useful for diagnosis of VKH disease in Brazilian patients. The present retrospective study did not find any association between disease category and severity parameters. To better understand the relevance of disease categories, a minimum follow-up period to categorize patients should be included in future prospective studies. (Am J Ophthalmol 2009;147:339-345. (C) 2009 by Elsevier Inc. All rights reserved.)

Characterization and in vitro evaluation of bacterial cellulose membranes functionalized with osteogenic growth peptide for bone tissue engineering

The aim of this study was to characterize the physicochemical properties of bacterial cellulose (BC) membranes functionalized with osteogenic growth peptide (OGP) and its C-terminal pentapeptide OGP[10-14], and to evaluate in vitro osteoinductive potential in early osteogenesis, besides, to evaluate cytotoxic, genotoxic and/or mutagenic effects. Peptide incorporation into the BC membranes did not change the morphology of BC nanofibers and BC crystallinity pattern. The characterization was complemented by Raman scattering, swelling ratio and mechanical tests. In vitro assays demonstrated no cytotoxic, genotoxic or mutagenic effects for any of the studied BC membranes. Culture with osteogenic cells revealed no difference in cell morphology among all the membranes tested. Cell viability/proliferation, total protein content, alkaline phosphatase activity and mineralization assays indicated that BC-OGP membranes enabled the highest development of the osteoblastic phenotype in vitro. In conclusion, the negative results of cytotoxicity, genotoxicity and mutagenicity indicated that all the membranes can be employed for medical supplies, mainly in bone tissue engineering/regeneration, due to their osteoinductive properties.

miR-21 may acts as an oncomir by targeting RECK, a matrix metalloproteinase regulator, in prostate cancer

Background: Prognosis of prostate cancer (PCa) is based mainly in histological aspects together with PSA serum levels that not always reflect the real aggressive potential of the neoplasia. The micro RNA (miRNA) mir-21 has been shown to regulate invasiveness in cancer through translational repression of the Metaloproteinase (MMP) inhibitor RECK. Our aim is to investigate the levels of expression of RECK and miR-21 in PCa comparing with classical prognostic factors and disease outcome and also test if RECK is a target of miR-21 in in vitro study using PCa cell line. Materials and methods: To determine if RECK is a target of miR-21 in prostate cancer we performed an in vitro assay with PCa cell line DU-145 transfected with pre-miR-21 and anti-miR-21. To determine miR-21 and RECK expression levels in PCa samples we performed quantitative real-time polymerase chain reaction (qRT-PCR). Results: The in vitro assays showed a decrease in expression levels of RECK after transfection with pre-miR-21, and an increase of MMP9 that is regulated by RECK compared to PCa cells treated with anti-miR-21. We defined three profiles to compare the prognostic factors. The first was characterized by miR-21 and RECK underexpression (N = 25) the second was characterized by miR-21 overexpression and RECK underexpression (N = 12), and the third was characterized by miR-21 underexpression and RECK overexpression (N = 16). From men who presented the second profile (miR-21 overexpression and RECK underexpression) 91.7% were staged pT3. For the other two groups 48.0%, and 46.7% of patients were staged pT3 (p = 0.025). Conclusions: Our results demonstrate RECK as a target of miR-21. We believe that miR-21 may be important in PCa progression through its regulation of RECK, a known regulator of tumor cell invasion.

Efficacy of Cosmetic Formulations Containing Dispersion of Liposome with Magnesium Ascorbyl Phosphate, Alpha-Lipoic Acid and Kinetin

The present study aimed to evaluate the photoprotective effects of cosmetic formulations containing a dispersion of liposome with magnesium ascorbyl phosphate (MAP), alpha-lipoic acid (ALA) and kinetin, as well as their effects on the hydration and viscoelastic skin properties. The photoprotection was determined in vitro (antioxidant activity) and in vivo on UV-irradiated hairless mouse skin. The hydration effects were performed with the application of the formulations under study on the forearm of human volunteers and skin conditions were analyzed before and after a single application and daily applications during 4 weeks in terms of transepidermal water loss (TEWL), skin moisture and viscoelastic properties. The raw material under study possessed free-radical scavenging activity and the formulation with it protected hairless mouse skin barrier function against UV damage. After 4 weeks of application on human skin, the formulation under study enhanced stratum corneum skin moisture and also showed hydration effects in deeper layers of the skin. Thus, it can be concluded that the cosmetic formulation containing a dispersion of liposome with MAP, ALA and kinetin under study showed photoprotective effects in skin barrier function as well as pronounced hydration effects on human skin, which suggests that this dispersion has potential antiaging effects.

Ocular manifestations of Noonan syndrome

Purpose: To describe the ophthalmological characteristics in a group of Noonan syndrome patients with proven mutations in the PTPN11 gene. Methods: Thirty-five Noonan syndrome patients with PTPN11 gene mutations underwent ophthalmological exams, which consisted of external inspection, slit-lamp biomicroscopy examination and an ophthalmoscopic examination after instillation of 1.0% tropicamide or 1.0% cyclopentolate. Results: All 35 patients had at least one abnormality upon ophthalmological examination. The eyelid and external eye abnormalities were the prevailing features, followed by prominent corneal nerves on slit-lamp exam. Fundus changes were detected in 8% of the subjects, mainly associated with high myopia. No statistically significant differences were observed among the patients presenting specific mutations in the PTPN11 gene. Conclusions: The current study further supports the finding that ocular symptoms account for a large fraction of the clinical manifestations of NS. Additional characteristics are described here. The roles for the various mutations of PTPN11 in ocular development are yet to be established.

Immediate and long-term effects of polysaccharides-based formulations on human skin

A new trend in cosmetic formulations is the use of biotechnological raw materials as the polysaccharides from Klebsiella pneumoniae, which are supposed to enhance cell renewal, improve skin hydration and micro-relief. Botanical extracts of Myrtus communis leaves contain different sugars, which may provide the same benefits. Thus, the objective of this study was to evaluate through objective and subjective analysis the immediate and long-term effects of cosmetic formulations containing polysaccharides biotechnologically-originated and / or the ones contained in Myrtus communis extracts. Three polysaccharide-based and placebo formulations were applied on the forearm skin of 40 volunteers. Skin hydration, transepidermal water loss (TEWL), viscoelasticity and skin micro-relief measurements were made before and 2 hours after a single application and after 15 and 30 day-periods of daily applications. Answers to a questionnaire about perceptions of formulation cosmetic features constituted the subjective analysis. All polysaccharide-based formulations enhanced skin hydration. Formulations with isolated or combined active substances improved skin barrier function as compared to placebo, in the short and long term studies. Formulations containing Myrtus communis extracts had the highest acceptance. Results suggest that daily use of formulations containing these substances is important for protection of the skin barrier function.

Vancomycin-resistant enterococcus outbreak in a pediatric intensive care unit: report of successful interventions for control and prevention

The objective of this study is to retrospectively report the results of interventions for controlling a vancomycin-resistant enterococcus (VRE) outbreak in a tertiary-care pediatric intensive care unit (PICU) of a University Hospital. After identification of the outbreak, interventions were made at the following levels: patient care, microbiological surveillance, and medical and nursing staff training. Data were collected from computer-based databases and from the electronic prescription system. Vancomycin use progressively increased after March 2008, peaking in August 2009. Five cases of VRE infection were identified, with 3 deaths. After the interventions, we noted a significant reduction in vancomycin prescription and use (75% reduction), and the last case of VRE infection was identified 4 months later. The survivors remained colonized until hospital discharge. After interventions there was a transient increase in PICU length-of-stay and mortality. Since then, the use of vancomycin has remained relatively constant and strict, no other cases of VRE infection or colonization have been identified and length-of-stay and mortality returned to baseline. In conclusion, we showed that a bundle intervention aiming at a strict control of vancomycin use and full compliance with the Hospital Infection Control Practices Advisory Committee guidelines, along with contact precautions and hand-hygiene promotion, can be effective in reducing vancomycin use and the emergence and spread of vancomycin-resistant bacteria in a tertiary-care PICU.

Maternal Melatonin Programs the Daily Pattern of Energy Metabolism in Adult Offspring

Background: Shift work was recently described as a factor that increases the risk of Type 2 diabetes mellitus. In addition, rats born to mothers subjected to a phase shift throughout pregnancy are glucose intolerant. However, the mechanism by which a phase shift transmits metabolic information to the offspring has not been determined. Among several endocrine secretions, phase shifts in the light/dark cycle were described as altering the circadian profile of melatonin production by the pineal gland. The present study addresses the importance of maternal melatonin for the metabolic programming of the offspring. Methodology/Principal Findings: Female Wistar rats were submitted to SHAM surgery or pinealectomy (PINX). The PINX rats were divided into two groups and received either melatonin (PM) or vehicle. The SHAM, the PINX vehicle and the PM females were housed with male Wistar rats. Rats were allowed to mate and after weaning, the male and female offspring were subjected to a glucose tolerance test (GTT), a pyruvate tolerance test (PTT) and an insulin tolerance test (ITT). Pancreatic islets were isolated for insulin secretion, and insulin signaling was assessed in the liver and in the skeletal muscle by western blots. We found that male and female rats born to PINX mothers display glucose intolerance at the end of the light phase of the light/dark cycle, but not at the beginning. We further demonstrate that impaired glucose-stimulated insulin secretion and hepatic insulin resistance are mechanisms that may contribute to glucose intolerance in the offspring of PINX mothers. The metabolic programming described here occurs due to an absence of maternal melatonin because the offspring born to PINX mothers treated with melatonin were not glucose intolerant. Conclusions/Significance: The present results support the novel concept that maternal melatonin is responsible for the programming of the daily pattern of energy metabolism in their offspring.