Abstract Background Subarachnoid hemorrhage (SAH) prognosis remains poor. Vasospasm mechanism might be associated with inflammation. Neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have been studied as inflammation markers and prognostic predictors. Objective We aimed to investigate NLR and PLR in admission as predictors of angiographic vasospasm and functional outcome at 6 months. Methods This cohort study included consecutive aneurysmal SAH patients admitted to a tertiary center. Complete blood count was recorded at admission before treatment. White blood cell count, neutrophil count, lymphocyte count, platelet count, NLR, and PLR were collected as independent variables. Vasospasm occurrence-modified Rankin scale (mRS), Glasgow outcome scale (GOS), and Hunt-Hess score at admission and at 6 months were recorded as dependent variables. Multivariable logistic regression models were used to adjust for potential confounding and to assess the independent prognostic value of NLR and PLR at admission. Results A total of 74.1% of the patients were female, with mean age of 55.6 ± 12.4 years. At admission, the median Hunt-Hess score was 2 (interquartile range [IQR] 1), and the median mFisher was 3 (IQR 1). Microsurgical clipping was the treatment for 66.2% of the patients. Angiographic vasospasm incidence was 16.5%. At 6 months, the median GOS was 4 (IQR 0.75), and the median mRS was 3 (IQR 1.5). Twenty-one patients (15.1%) died. Neutrophil-to-lymphocyte ratio and PLR levels did not differ between favorable and unfavorable (mRS > 2 or GOS < 4) functional outcomes. No variables were significantly associated with angiographic vasospasm. Conclusion Admission NLR and PLR presented no value for prediction of functional outcome or angiographic vasospasm risk. Further research is needed in this field.

Resumo Antecedentes O prognóstico da hemorragia subaracnoidea (HSA) permanece ruim. Vasoespasmo pode estar associado à inflamação. Razões neutrófilo-linfócito (NLR) e plaqueta-linfócito (PLR) têm sido estudadas como marcadores de inflamação e prognóstico. Objetivo Investigar NLR e PLR na admissão como preditores de vasoespasmo angiográfico e desfecho aos 6 meses. Métodos Este estudo de coorte incluiu pacientes consecutivos com HSA aneurismática de um centro terciário. Contagem de leucócitos, neutrófilos, linfócitos e plaquetas, proporção de neutrófilos para linfócitos e de plaquetas para linfócitos foram coletados como variáveis independentes. Ocorrência de vasoespasmo, escala de Rankin modificada, escala de desfecho de Glasgow e o escore de Hunt-Hess na admissão e 6 meses após a mesma foram registradas como variáveis dependentes. Modelos de regressão logística multivariável foram usados para ajustar potenciais fatores de confusão e avaliar valor prognóstico independente de NLR e PLR. Resultados Um total de 74,1% pacientes eram do sexo feminino, com idade média de 55,6 ± 12,4 anos. Na admissão, a pontuação média de Hunt-Hess foi de 2 (IQR 1) e a mediana de mFisher foi de 3 (IQR 1). Clipagem microcirúrgica foi o tratamento escolhido para 66,2% dos pacientes. A incidência de vasoespasmo angiográfico foi de 16,5%. Aos 6 meses, a escala de desfecho de Glasgow mediana era 4 (IQR 0,75) e a escala de Rankin modificada mediana era 3 (IQR 1,5). Vinte e um pacientes (15,1%) morreram. Os níveis de NLR e PLR não diferiram entre resultados funcionais favoráveis e desfavoráveis (mRS > 2 ou GOS < 4). Nenhuma variável foi significativamente associada ao vasoespasmo angiográfico. Conclusão Razão neutrófilo-linfócito e a PLR não apresentaram valor preditivo de desfecho funcional ou risco de vasoespasmo angiográfico. Mais pesquisas são necessárias neste campo.

RESUMEN Introducción: Accidente cerebro vascular (ACV) o Ictus es un síndrome de inicio repentino caracterizado por cambios focales o globales en la función cerebral como consecuencia de un trastorno de origen vascular en un desarrollo superior a 24 horas. Dependiendo de la naturaleza de la lesión, puede ser isquémica o hemorrágica. Pudiendo ser la hemorrágica ser intraparenquimatoso o subaracnoideo. El ACV es la segunda causa principal de muerte adulta en el mundo. Existen varios hechos de riesgo asociados a la enfermedad, entre ellos la hipertensión, que es uno de los factores que ha incrementado exponencialmente los casos. Siendo este prevalente como factor de riesgo en la población. Objetivo: Conocer el perfil clínico y radiológico de los pacientes con evento cerebro vascular tratados en la Clínica Sagrada Esperanza de enero a diciembre de 2018. Métodos: La población de estudio estuvo conformada por todos los pacientes hospitalizados del 1 de enero al 31 de diciembre de 2018, con los siguientes códigos diagnósticos de liberación: I60 (Hemorragia subaracnoidea), I61 (Hemorragia intracerebral), I62 (Otra Hemorragia Subaracnoidea no traumática), I63 (Infarto cerebral), I64 (ACV no especificado), G45 (Ictus Isquémico Transitorio y Síndromes Correlacionados), conformando un total de 312 listados pacientes, de los cuales 211 fueron excluidos por tener antecedentes de la enfermedad en estudio, 18 por diagnóstico erróneo en el proceso y 8 casos se perdieron debido a falta de informes de exámenes. Hubo 75 casos para el estudio. Resultados: Del total de casos estudiados, el grupo de edad más prevalente fue de 41-60 años que representa el 45%, la edad promedio fue de 58,8 ± 13 años, el género masculino representó 45 casos (60%); Predominaron la raza negra con 64 casos (89%). La hipertensión arterial fue el factor más evidente 48 (64%). El ictus isquémico fue el más frecuente con 42 casos (56%). El promedio de la estancia fue de 9,4±7,3 días, La hemiparesia fue el déficit más evidente tanto en el ictus isquémico 34 (18%) como en el ictus hemorrágico 18 (9%), como en el fallecimiento de 4 pacientes (5%). La arteria cerebral media fue la región más afectada 43 (57.3%) tanto en el ictus isquémico 24 (32%) como en el ictus hemorrágico intraparenquimatosos 17 (53,1%) y subaracnoideos 2 (3,7%). Conclusión: La mayoría de los pacientes tenían entre 40 y 80 años, sexo masculino y afro americanos. El ictus fue más frecuente, y la zona más afectada fue la arteria cerebral media, siendo el déficit más frecuente la hemiparesia y la paresia facial; El factor de riesgo más común fue la hipertensión. En lo que respecta a la duración de la estancia, la mayoría de ellos permanecieron de 5 a 9 días y pocos de ellos murieron.

ABSTRACT Introduction: Cerebral Vascular Acident (CVA) or Stroke is a sudden onset syndrome characterized by focal or global changes in the brain funcion as consequence of a desorder of vascular origin witen a development longer than 24 hours. Depending or the nature of the injury, it can be Ischemic or Hemorrhsgic. The latter way be intraparenchymator or subarachnoid. Stroke is the second leading cause of death adult disability in the world. There are several risk factos associated with the above mentioned disease, among them the hypertension. There is an exponential increase in cases of fore mentioned disease as well as in the prevalence of risk factos in population. Objective: To know clinical and radiological profile of patients with CVA treated at Sagrada Esperança Clinic, from January to December 2018. Materials and Methods: The universe of study consisted of all the files of patients admitted from january 1st to December 31 st, 2018, with the following release diagnostic codes: I60 ( subarachnoid Hemorrhage), I61 ( Intracerebral Hemorrhage), I62 ( Other non-traumatic Subarachnoid Hemorrhage), I63 ( Cerebral Infarction), I64 (not specified), G45 (Transient Ischemic Stroke and Correlated syndromes), making up a total a 312 listed patients, of which 211 were excluded by having a history of the disease being studied, 18 due to misdiagnosis in the process and 8 cases were lost due to non exam or reports on the severs. There were 75 cases for the study. Results: From the total number of cases studied which is 75, the most prevalent age group was from 41-60 years old which makes up 45%, the average age was 58,8 ± 13 years old, the male gender represented 45 cases (60%); Blacks were predominant with 64 cases (89%). Ischemic stroke was the most frequent with 42 cases (56%), the average hospitalization was the most prevalente deficit in both Isquemic VCA, with 18 cases (9%), and 4 patients (5%) died. The widdle cerebral arrtery área was the most affected in both Isquemic 23 cases (30,7%) and Intraparenchymal Hemorrhagie Strokes 17 cases (53,1%) and subarachnnoid 2 cases (3,7%). Conclusion: Most patients were 40-80 years old, male and black. Stroke was more frequent, and the most affected área was the middle cerebral artery, with the most frequent deficit being hemiparesis and facial paresis; The most aommon risk factor was Hypertension. In regards to the lenth of stay mosto f them were in the clinic from 5-9 days and few of them died.

In times of fierce neoliberal politics committed to accelerated productivism, scientific research paper is one of the forms of communication that most circulate in the academic-scientific field, an object on which many of the institutional ranking indices fall and is itself a recurring theme of studies related to the literacy studies, writing didactics and discourse studies. We found in Swales (1990) proposals that seek to articulate knowledge from different theoretical fields that can contribute to the didactics of academic writing. In this area, the main objective of this study is to understand how the scientific paper introduction and conclusion rhetorical orientationnbsp; in the area of Education is present in the compositionality, style and thematic development of this genre. This is a documentary research, whose corpus is composed of 16 papers in the Education field, with the journals being evaluated as Qualis A1, in the Capes 2013-2016 quadrennium. The results reveal the presence of the rhetorical movements pointed out by Swales, through the discursive strategies of stance and engagement (HYLAND, 2015), and contribute to the compositionality of the genre. Despite this, it is not possible to state, as described by Swales, that such movements are mandatory. It was also verified that the configurations of systematic language choices must be understood within a disciplinary field and that the text reflects the choices and limitations that act on the authors.

En tiempos de feroz política neoliberal comprometida con el productivismo acelerado, el artículo es una de las formas de comunicación que más circulan en el campo académico-científico, objeto sobre el que recaen muchos de los índices del ranking institucional y es en sí mismo un tema recurrente de estudios vinculados a los estudios de alfabetización, didáctica de la escritura y estudios del discurso. Encontramos en Swales (1990) propuestas que buscan articular saberes de distintos campos teóricos que puedan contribuir a la didáctica de la escritura académica. En ese ámbito, el objetivo principal de este estudio es comprender cómo la orientación retórica de las introducciones y conclusiones de los artículos científicos del área de la Educación está presente en la composicionalidad, el estilo y el desarrollo temático de este género. Se trata de una investigación documental, cuyo corpus está compuesto por 16 artículos del área de Educación, siendo las revistas evaluadas como Qualis A1, en el cuatrienio Capes 2013-2016. Los resultados revelan la presencia de los movimientos retóricos señalados por Swales, a través de las estrategias discursivas de compromiso y posicionamiento (HYLAND, 2015), y contribuyen a la composicionalidad del género. A pesar de esto, no es posible decir, como lo describe Swales, que tales movimientos sean obligatorios. También se verificó que las configuraciones de elecciones sistemáticas del lenguaje deben ser comprendidas dentro de un campo disciplinar y que el texto refleja las elecciones y limitaciones que actúan sobre los autores.

Em tempos de acirrada política neoliberal comprometida com o produtivismo acelerado, o artigo é uma das formas de comunicação que mais circulam no âmbito acadêmico-científico, objeto sobre o qual recaem muitos dos índices de ranqueamento institucionais e é ele próprio tema recorrente de estudos vinculados aos estudos do letramento, à didática da escrita e aos estudos do discurso. Encontramos em Swales (1990) propostas que buscam articular saberes de campos teóricos distintos que podem contribuir para a didática da escrita acadêmica. Nessa seara, o objetivo principal deste estudo é compreender como a orientação retórica de introduções e conclusões dos artigos científicos da área da Educação se faz presente na composicionalidade, no estilo e no desenvolvimento temático desse gênero. Trata-se de uma pesquisa documental, cujo corpus é composto por 16 artigos da área da Educação, tendo sido os periódicos avaliados como Qualis A1, no quadriênio Capes 2013-2016. Os resultados revelam a presença dos movimentos retóricos apontados por Swales, por meio das estratégias discursivas de engajamento e posicionamento (HYLAND, 2015), e contribuem para a composicionalidade do gênero. Apesar disso, não é possível afirmar, como descrito por Swales, que tais movimentos sejam de ordem obrigatória. Verificou-se também que as configurações de escolhas sistemáticas de linguagem devem ser compreendidas no interior de um campo disciplinar e que o texto reflete as escolhas e as limitações que atuam sobre os autores.

ABSTRACT The increasing rates of nosocomial infection associated with coagulase-negative staphylococci (CoNS) were the rationale for this study, aiming to categorize oxacillin-resistant CoNS species recovered from blood culture specimens of inpatients at the UNESP Hospital das Clínicas in Botucatu, Brazil, over a 20-year period, and determine their sensitivity to other antimicrobial agents. The mecA gene was detected in 222 (74%) CoNS samples, and the four types of staphylococcal chromosomal cassette mec (SCCmec) were characterized in 19.4%, 3.6%, 54.5%, and 14.4% of specimens, respectively, for types I, II, III, and IV. Minimal inhibitory concentration (MIC) values to inhibit 50% (MIC50) and 90% (MIC90) of specimens were, respectively, 2 and >256 µL/mL for oxacillin, 1.5 and 2 µL/mL for vancomycin, 0.25 and 0.5 µL/mL for linezolid, 0.094 and 0.19 µL/mL for daptomycin, 0.19 and 0.5 µL/mL for quinupristin/dalfopristin, and 0.125 and 0.38 µL/mL for tigecycline. Resistance to oxacillin and tigecycline and intermediate resistance to quinupristin/dalfopristin were observed. Eight (2.7%) of all 300 CoNS specimens studied showed reduced susceptibility to vancomycin. Results from this study show high resistance rates of CoNS to antimicrobial agents, reflecting the necessity of using these drugs judiciously and controlling nosocomial dissemination of these pathogens.

ABSTRACT Radiation-induced brachial plexus neuropathy (RIBPN) is a rare and delayed non-traumatic injury to the brachial plexus, which occurs following radiation therapy to the chest wall, neck, and/or axilla in previously treated patients with cancer. The incidence of RIBPN is more common in patients treated for carcinoma of the breast and Hodgkin lymphoma. With the improvement in radiation techniques, the incidence of injury to the brachial plexus following radiotherapy has dramatically reduced. The currently reported incidence is 1.2% in women irradiated for breast cancer. The progression of symptoms is gradual in about two-thirds of cases; the patients may initially present with paresthesia followed by pain, and later progress to motor weakness in the affected limb. We present the case of a 68-year-old female patient with breast cancer submitted to surgery, chemotherapy, and radiotherapy in the year 2000. Eighteen years later, she developed symptoms and signs compatible with RIBPN and was successfully submitted to omentoplasty for pain control. Omentoplasty is an alternative treatment for RIBPN refractory to conservative treatment, which seems to be effective in improving neuropathic pain. However, postoperative worsening of the motor strength is a real possibility, and all candidates for this type of surgery must be informed about the risk of this complication.

ABSTRACT Compressive syndromes of peripheral nerves both in the upper and lower limbs are part of daily clinical practice; however, the etiological diagnosis can be challenging and impact on the outcome of the patient. We report five cases with rare etiologies of nerve entrapments: one in the lower limb and four in the upper limbs with the final diagnosis made only during the operation. The patients evolved without post-operative complications and had good outcomes. This series includes the first report of sciatic compression by a lipoma in the popliteal fossa, two lipomas one with compression of infraclavicular brachial plexus and another with compressing the posterior interosseous nerve, and two reports of vascular lesions due to blunt traumas, which are also uncommon. This series adds to the literature more hypotheses of differential diagnoses in nerve entrapments, which is fundamental to surgical decisions and pre-operative planning—and perhaps most importantly prevents wrong diagnosis of idiopathic compressions, which would lead to a completely wrong approach and unfavorable outcomes.

Resumo A finalidade do presente estudo foi avaliar a presença de anticorpos anti- Toxocara, em frangos de corte naturalmente infectados (n = 189), no Norte do Paraná, Sul do Brasil. Os frangos foram criados em sistema semi-intensivo, em pequenas propriedades rurais (n = 7). Os testes sorológicos foram realizados pela técnica de ELISA, para detecção de anticorpos IgY (IgG), com pré-adsorção do soro com antígenos de Ascaridia galli. Foi observada uma prevalência de 67,7% (128/189; IC 95% = 61,1-74,4). A frequência de animais soropositivos por propriedade variou de 29,6% a 100%. Os valores da Densidade Ótica e do Índice de Reatividade observados no teste de ELISA indicaram uma possível cronicidade de infecção dos frangos avaliados. Não foi observada correlação entre a positividade dos animais, quando comparada a área (p = 0,382) e a densidade populacional de cães por propriedade (p = 0,785). O presente estudo verificou uma alta prevalência de anticorpos anti-Toxocara em frangos de corte criados em sistema semi-intensivo e oferece dados que apontam esses animais como bons indicadores de contaminação ambiental por agentes de larva migrans . Estudos futuros são necessários para avaliar os fatores de risco associados e a possibilidade da transmissão de toxocaríase ao ser humano pela ingestão de carne de frango.

Abstract The aim of this study was to evaluate the presence of anti-Toxocara antibodies in naturally infected broiler chickens (n = 189) from the state of Paraná, southern Brazil. The chickens were reared in a semi-intensive system by small family farmers (n = 7). An enzyme-linked immunosorbent assay (ELISA) was performed to detect the presence of anti- Toxocara spp. IgY after serum adsorption with Ascaridia galli antigens. An overall seroprevalence of 67.7% (128/189; 95% CI = 61.1-74.4) was observed. The frequency of positive animals by farm ranged from 29.6% to 100%. The optical density and reactivity index values observed in ELISA test indicated the possible chronicity of infection of the evaluated chickens. Associations between the presence of antibodies and the area where the chickens were reared (p = 0.382) or the population density of dogs on the farm (p = 0.785) were not observed. This study shows a high prevalence of Toxocara spp. antibodies in broiler chickens reared in semi-intensive systems and provides evidence that chickens are a good indicator of environmental contamination by larva migrans agents. Further studies are necessary to assess the risk factors associated with poultry infection and the likelihood of toxocariasis transmission to humans via the ingestion of free-range chicken meat.

Resumo: O objetivo deste trabalho foi avaliar a dinâmica do crescimento das plantas de cobertura amaranto (Amaranthus cruentus), quinoa (Chenopodium quinoa) e milheto (Pennisetum glaucum) em Latossolo Vermelho, sob diferentes regimes hídricos no Cerrado. O cultivo foi realizado no inverno, com pluviosidade reduzida, o que facilitou a aplicação de lâminas de irrigação nas diferentes culturas. No experimento foram avaliados regimes hídricos intitulados de inferior, médio inferior, médio superior e superior, correspondentes à aplicação respectiva de 217, 386, 563 e 647 mm de lâminas de água, por meio de uma barra irrigadora composta por aspersores de diferentes vazões. O crescimento das plantas foi quantificado mediante coletas com periodicidade semanal. O amaranto foi a planta mais responsiva à água. A quinoa apresentou o melhor desempenho no tratamento com nível de água médio superior entre as espécies avaliadas. O milheto apresentou sensibilidade térmica ao cultivo no inverno, o que inviabilizou a produção de grãos; porém, mostrou excepcional aptidão quanto à produção de biomassa, inclusive no tratamento com maior deficit hídrico.

Abstract: The objective of this work was to evaluate the growth dynamics of the cover plants amaranth (Amaranthus cruentus), quinoa (Chenopodium quinoa), and millet (Pennisetum glaucum) in a Typic Acrustox, under different water regimes in the Brazilian Cerrado. The cultivation was carried out in the winter, with reduced rainfall, which facilitated the application of varying irrigation depths to the different crops. Water regimes denominated lower, lower middle, upper middle, and upper - corresponding to 217, 386, 563, and 647 mm water depths, respectively - were tested by means of an irrigation bar composed of sprinklers with different flow rates. Plant growth was quantified by weekly collections. Amaranth was the most responsive plant to water. Quinoa showed the best performance in the treatment with the upper-middle water level among the other evaluated species. Millet showed thermal sensitivity for cultivation in the winter, making grain production unfeasible; however, it showed exceptional ability to produce biomass even in the treatment with higher water deficit.

Abstract Nanoparticles nickel-doped cobalt ferrites [NixCo1-xFe2O4 (x = 0.0, 0.25, 0.50, 0.75 and 1.0 of Ni2+)] were prepared by the microwave combustion synthesis, using a stoichiometric mixture of metal nitrates and urea as the oxidizer and fuel to drive the reaction. The effect of microwave irradiation on the phase composition was favorable to promote the formation of fluffy foams and nanoparticles sizes. The fast internal heating with microwaves leads to a reduction in synthesis time, to only 2 min. The structural, chemical and magnetic properties of the nickel-doped cobalt ferrites were analyzed by XRD, TEM, SEM and BET. The XRD results confirmed the formation of pure and single-phase spinel structure. The crystallite size of the nanoparticles was in the range of 38 - 50 nm. SEM images show nanoparticles with spherical shape and homogenous morphology. The TEM analysis shows necked near-spherical particles with an average size of ~30 - 50 nm, reflecting the highly crystalline nature of these nanoparticles. The magnetic measurements of all the samples were recorded using vibrating sample magnetometer (VSM) at room temperature in 10 kOe. Increasing the nickel content directly affects the structural characteristics of the particles, causing a reduction in the coercive field.

Wetlands are common in the Cerrado (Brazilian savannas) biome, however flooding of these wetlands impairs growth and development of most plants. We evaluated flood tolerance of typical Cerrado trees. Seedlings of Aspidosperma macrocarpon (Apocynaceae), Tabebuia rosea (Bignoniaceae), Handroanthus chrysotrichus (Bignoniaceae), Myracrodruon urundeuva (Anacardiaceae), Kielmeyera coriacea (Calophyllaceae) and Copaifera langsdorffii (Fabaceae) were flooded up to the stem base for 30 days. Stems with cortical cracks, secondary aerenchyma and hypertrophic lenticels were observed in flooded plants of M. urundeuva,H. chrysotrichus and T. rosea while adventitious roots were formed in flooded plants of T. rosea and H. chrysotrichus. However, only T. rosea developed aerenchyma in the root cortex. K. coriacea and A. macrocarpon were the most sensitive to flooding, showing a decrease in survival and necrosis of the leaves and roots. C. langsdorffii and M. urundeuva were less sensitive to flooding, although reductions in root biomass and symptoms of necrosis of the roots were noticeable in flooded seedlings. Flooded M. urundeuva seedlings also had a decrease in total leaf area, leaf biomass, total biomass and in stem growth. Flooding affected root development and reduced stem growth of H. chrysotrichus with symptoms of necrosis of the leaves and roots. T. rosea was the only species where symptoms of injury from flooding were not evident.

Poly(glycolide-co-lactide) (PLGA) nanospheres containing magnetic materials have been extensively studied because of its biomedical applications. Therefore, it is very important to know thermal properties of these materials in addition to other physical properties. Thermal degradation activation energy (Eα) of PLGA nanospheres with maghemite entrapment (PLGA-Mag), PLGA nanospheres (hollow spheres) (PLGA-H) obtained by an emulsion method and unprocessed PLGA (PLGA-R) were calculated by isoconversional Vyazovkin method based on data of TG analysis in order to evaluate modifications in thermal behavior caused by nanospheres obtainment process or by maghemite entrapment. Both hydrodynamic diameter in the range of 200-250 nm and polydispersity index lower than 0.3 are considered satisfactory. Thermal degradation of PLGA-R begins at higher temperatures than those of PLGA-H and PLGA-Mag, but processed samples presented increase in thermal stability, which was greater before processing by emulsion and in the presence of the magnetic materials. PLGA-Mag presents superparamagnetic behavior at room temperature.

A cada dia se torna mais frequente o uso de aparelhos eletrônicos que, em sua grande maioria, estão baseados em diodos e transistores semicondutores. Compreender alguns conceitos ligados a esses materiais pode ser muito importante para entender e se relacionar melhor com tais aparelhos. Apesar de essa ser uma constatação que aparece também em documentos oficiais e nos parâmetros curriculares nacionais (PCN), o que se observa na prática é um número muito reduzido de propostas neste sentido. Assim, o objetivo desse trabalho foi descrever o uso de uma sequência de quatro vídeos curtos para ensinar tópicos de semicondutores no Ensino Médio. Eles foram aplicados em duas turmas de terceiro ano do Ensino Médio, num total de 72 estudantes. Após cada vídeo, foi entregue um questionário com 16 itens de Likert, a fim de medir as atitudes dos estudantes em relação a alguns conceitos abordados nos vídeos. Analisando os resultados obtidos nos questionários, observou-se que a proposta se mostrou bastante eficaz, principalmente no que diz respeito à motivação dos alunos em estudar o assunto. A maior parte dos conceitos foi bem assimilada, e as poucas dificuldades apresentadas estavam de acordo com a literatura. Isso sugere que o uso de vídeos curtos é uma estratégia que pode ser mais utilizada, principalmente devido à sua versatilidade e à pequena demanda de recursos técnicos.

The daily use of electronic devices, which are mostly based on semiconductor diodes and transistors, has become very common. The understanding of some concepts related to semiconductor materials is very important to achieve a better comprehension of these devices. Although this statement appears in the official documents and in national Brazilian curricular parameters (PCN), in practice there is a small number of proposals in this direction. Thus, the purpose of this article was to describe the use of a sequence with four short videos to teach introductory concepts of semiconductors at high-school level. These videos were shown to two classes of third grade of high school, with a total of 72 students. After each video, we gave the students a questionnaire with 16 Likert items, in order to measure the students’ attitudes regarding some concepts discussed in the videos. Analyzing the questionnaire results, we saw the effectiveness of the proposal, mainly with respect to the students motivation to study this subject. The majority of concepts were well assimilated, and the few difficulties were in agreement with literature. This suggests that the use of short videos is a strategy that can be more used, mainly due its versatility and very limited need of technical resources.

This study aimed to correlate the presence of ica genes, biofilm formation and antimicrobial resistance in 107 strains of Staphylococcus epidermidis isolated from blood cultures. The isolates were analysed to determine their methicillin resistance, staphylococcal cassette chromosome mec (SCCmec) type, ica genes and biofilm formation and the vancomycin minimum inhibitory concentration (MIC) was measured for isolates and subpopulations growing on vancomycin screen agar. The mecA gene was detected in 81.3% of the S. epidermidis isolated and 48.2% carried SCCmec type III. The complete icaADBC operon was observed in 38.3% of the isolates; of these, 58.5% produced a biofilm. Furthermore, 47.7% of the isolates grew on vancomycin screen agar, with an increase in the MIC in 75.9% of the isolates. Determination of the MIC of subpopulations revealed that 64.7% had an MIC ≥ 4 μg mL-1, including 15.7% with an MIC of 8 μg mL-1 and 2% with an MIC of 16 μg mL-1. The presence of the icaADBC operon, biofilm production and reduced susceptibility to vancomycin were associated with methicillin resistance. This study reveals a high level of methicillin resistance, biofilm formation and reduced susceptibility to vancomycin in subpopulations of S. epidermidis. These findings may explain the selection of multidrug-resistant isolates in hospital settings and the consequent failure of antimicrobial treatment.

Iron oxide nanoparticles (ION) have been studied for essential applications, like detection of biological constituents (virus, bacterials, cell, nucleic acids, protein, enzyme, etc.), magnetic bioseparation and clinic therapy and diagnosis (such as MRI magnetic fluid and hyperthermia). In this work, γ-Fe2O3has been synthetized by a adapted sol-gel method and entraped in poly ε-caprolactone (PCL) nanocapsules. The superparamagnetic nanocapsules have been formulated by double emulsion evaporation method. Some variables affecting the polydispersity index, zeta potential surface and size of nanocapsules were studied aiming optimize the formulation process of maghemite-loaded PCL nanocapsules. The following parameters were selected: sonication time, PCL concentration in organic phase, PVA concentration in external aqueous phase and maghemite/PCL weight ratio. Under these experimental conditions, the resulting nanocapsules displayed a mean size of about 346 nm and a maghemite content of about 7.5 µg/mg of nanocapsules and superparamagnetic behaviour at room temperature.