Estrutura eletrônica de derivados de C60 para aplicações em células solares orgânicas

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Critérios de qualidade em artigos e periódicos científicos: da mídia impressa à eletrônica

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

Avaliação da integridade estrutural em um tubo de aço API 5L X70 através da propagação de trincas por fadiga

Pós-graduação em Engenharia Mecânica - FEG

Eficiência de detergentes e EDTA na remoção da smear layer de superfícies radiculares submetidas a raspagem e aplainamento: análise através da microscopia eletrônica de varredura

A remoção da smear layer é um procedimento importante para a regeneração periodontal e para o tratamento da sensibilidade dentinária. Diversos tratamentos tem sido realizados para sua remoção, porém, mostrando resultados conflitantes ou insatisfatórios. No presente estudo nos propomos a analisar através do microscópio eletrônico de varredura a eficiência dos detergentes: lauril sulfato de sódio, Plax e de mamona assim como o EDTA 24% na remoção da smear layer. Todos os produtos testados foram aplicados com bolinha de algodão, renovada a cada 30 segundos, a qual era esfregada na superfície radicular por diferentes períodos. As fotomicrografias foram analisadas através da aplicação de um índice de remoção da smear layer por três examinadores calibrados e os resultados analisados estatisticamente. De acordo com nossos resultados pudemos chegar as seguintes conclusões: 1- a instrumentação com curetas de Gracey provocou a formação da smear layer; 2- o detergente lauril sulfato de sódio não removeu a smear layer, tendo sido o pior resultado entre os detergentes testados; 3- Os detergentes Plax e de mamona mostraram resultados semelhantes entre si e superiores ao controle negativo e ao lauril sulfato de sódio, porém, não removeram a smear layer satisfatoriamente; 4- O EDTA 24% neutro mostrou ser eficiente para a remoção da smear layer.

Efeitos do antidepressivo cloridrato de fluoxetina na integridade histológica dos túbulos seminíferos de ratos adultos

A fluoxetina, pertencente à classe dos inibidores da recaptação seletiva de serotonina, é um dos antidepressivos mais amplamente prescritos para o tratamento da depressão e de transtornos da ansiedade, como o transtorno obsessivo compulsivo. Considerando que, dentre os efeitos colaterais causados pela fluoxetina, têm sido relatados distúrbios na função sexual masculina, foi proposto avaliar a ação deste fármaco sobre a integridade morfológica dos túbulos seminíferos. Foram utilizados 16 ratos adultos, distribuídos em 2 grupos: grupo fluoxetina (GF) e grupo controle (GC). Os animais do GF receberam injeções intraperitoneais de fluoxetina (20mg/Kg) e os animais do GC receberam água destilada. O tratamento se estendeu por 11 dias consecutivos e, ao final do tratamento, foram obtidos os pesos corpóreo e testicular dos animais. Os testículos foram fixados e processados para inclusão em historesina e parafina. Nos cortes de historesina, as frequências de túbulos de acordo com o estágio do ciclo do epitélio seminífero e de túbulos seminíferos contendo células descamadas preenchendo a luz tubular foram obtidas, bem como os seguintes parâmetros morfométricos: área tubular total, área da luz tubular e área do epitélio seminífero. Os cortes em parafina foram submetidos ao método do TUNEL para detecção de morte celular. Os níveis séricos de testosterona também foram avaliados. Os resultados foram submetidos à análise estatística para avaliação das diferenças entre os grupos. O tratamento com fluoxetina causou redução significante do peso corpóreo dos animais e redução, embora não significante, do peso testicular absoluto. Além disso, uma redução significante nos níveis séricos de testosterona foi observada nos animais do GF. Os túbulos seminíferos apresentaram contorno irregular, depleção celular e intensa desorganização epitelial, bem como a presença de vacúolos e ...

Estudo da dose efetiva, razão sinal-ruído e razão contraste-ruído em tomografia computadorizada de múltiplos detetores

Since discovery, computed tomography is a widely used diagnostic modality. However, this modality imparts relatively high doses to the patients and with fast technological advancement, it is necessary optimize the doses used and ensure the quality of the images through a quality assurance program. This work intended to compare Computed Tomography Dose Index (CTDIW) and effective dose with components of image quality: the Contrast-to-Noise Ratio (CNR) and Signal-to-Noise Ratio (SNR), and a quality factor (Q) deduced by the Rose model for two groups of computed tomography units. The first group was composed by equipments with 10 up to 16 slices and the second one presented 40 up to 320 slices detectors, for the protocols of head and abdomen. It was realized a comparison between different selectable parameters in the protocol of a Philips Brilliance 16, too. The results of the first group to CTDIW, effective dose, SNR and CNR showed variations of 28%, 33%, 37% and 32% respectively for head protocol, and 21%, 27%, 43% and 37% respectively for abdomen protocol. The results of the group 2 to CTDIW, effective dose, SNR and CNR showed variations of 15%, 26%, 36% and 34% respectively for the head protocol, and 8%, 13%, 50% and 60% respectively for abdomen protocol. The comparison between both groups demonstrated similar levels of doses impartation to patients though having so many different configurations, if the uncertainties associated with this measurement were considered. The results of the comparison between different parameters in the Philips Brilliance 16 scanner were in agreement with expected

Estudo da toxicidade de diferentes doses do Diuron (3-(3,4 -dichlorophenyl)-1,1-dimethylurea) no epitélio da bexiga de ratos wistas machos por microscopia eletrônica de varredura

Diuron (3-(3,4-Dichlorophenyl)-1,1-dimethylurea) is a substituted urea herbicide widely used on agricultural crops such as soy, cotton and sugar cane. In a previous long-term study this herbicide exerted carcinogenic activity on the urinary bladder and renal pelvis mucosa of Wistar rats and breast of mice. Also, it was shown to be carcinogenic to the mice skin in a initiation-promotion assay. In 1997, the northamerican EPA evaluated Diuron as a “known/likely” carcinogen for humans (USEPA, 2004). In a previous study developed at this laboratory, male Wistar rats treated with Diuron 2500 ppm during 20 weeks presented increased indices of cell proliferation and incidences of simple urothelial hyperplasia (HS) in the urinary bladder. Under scanning electron microscopy (SEM) severe urothelial necrosis and hyperplasia were observed. However, in that study the urinary bladders of animals exposed to lower doses of Diuron were not examined under SEM. Therefore, the possible dose-response influence of Diuron on the urothelium under SEM is not known. The present study aimed to analyze under SEM the urinary bladder of male Wistar rats exposed to 125 ppm, 500 ppm and 2500 ppm doses of Diuron through diet during 20 weeks and to compare to the previous histological findings in the same material. Under SEM, 125 ppm and 2500 ppm groups presented significantly (p<0,05) increased incidences of simple hyperplasia, i.e., 7/10 and 8/10 respectively, compared to control group and the 500 ppm group The sensitivity of SEM was higher since it detected a 45% incidence of hyperplasiaswhile the histological analysis found only 27%. Considering SEM as the gold-standard, histology showed a 44% sensitivity, 86.4% specificity, a positive predictive value of 72,7% and negative predictive value of 65,5% and accuracy of 67,5%. Scanning Electron Microscopy...(Complete abstract click electronic access below)

Comparação da razão sinal-ruído e da uniformidade da imagem entre aquisições com bobina de quadratura e com bobina de corpo

The signal-to-noise ratio and image uniformity analysis parameters are very important in quality control of an MRI scanner. They are measured in regular tests with phantoms. In these tests, however, used to quadrature coil, which has been most widely used clinically, and, therefore, was replaced in the procedures for body coil. In order to understand the difference between these two parameters in these coils, the study aimed to analyze the images acquired from four different phantoms in the same equipment under the same conditions for comparison purposes. With these results, it can be concluded that the body coil signal-to-noise ratio has always smaller than the quadrature in any projection, whereas the image uniformity is larger

Instrumentação eletrônica para experimentação do modelo Bouncer Ball dissipativo

In our experiments, we studied the classical dynamic of a particle in vertical motion subject to a constant gravitational field and the partial shock with an elastic wall with oscillatory motion located below the particle. The motion of the particle was confined to the vertical direction by a glass guide tube, which was initially evacuated, allowing viscous drag forces to be disregarded. The time between impacts, as well as the time between the reference phase of the movement of the base and the moment of impact and the period of oscillation of the base will be acquired by a hardware and software to obtain the phases space to be compared later with the description of the system through mapping discrete variables via the 'particle velocity immediately after shock 'and' phase of the movement of the base at the instant of shock 'obtained by computer simulation. This requires developing an electronic analog system followed by Digital implemented in reconfigurable logic, more specifically a sequential machine able to discriminate the impact with the metal base from the impacts of the glass guide tube, based on the frequency spectrum of the response of the microphone to these different impacts

A coordenação motora de indivíduos com Transtorno do Desenvolvimento da Coordenação (TDC): o ritmo em foco

The aim of the present study was to examine tapping synchronization in children with and without Developmental Coordination Disorder (DCD). Participants were 27 children from which 13 diagnosed with motor difficulties composed the DCD group and 14 children with typical development (TD) the comparison group. The experimental task consisted of performing 25 continuous tapping on a surface of an electronic drum with the preferred hand. Participants were required to tap in synchrony with an auditory bip generated by customized software. Three interval values the tapping task were tested: 470 ms, 1000 ms, 1530 ms. The dependent variables were constant error (CE) and absolute error (AE) and standard deviation of absolute error (SD of AE). The ANOVA 2 x 3 x 3 (Group X Age x Interval) with repeated measures in the last factor for the CE indicated significant interaction among Group X Age X Interval. For the AE and SD of AE the ANOVAs yielded significant main effect of Interval and a significant interaction between Group X Interval. The results of the present study indicated that children with DCD were less accurate and more variable in the tapping synchronization than children with TD. Differences in performance between DCD and children with TD become larger as the interval of the auditory signal increases.

Análise da expressão gênica de pequenos RNAs derivados de tRNAs (tRFs) em plantas

Small non coding RNAs emerged as important characters in several biology aspects. Among then, the most studied are microRNAs (miRNAs) and short interfering RNAs (siRNAs), that regulate their target gene post-transcriptionally in plants, animals and RNAi pathway intermediates, respectively. Both of classes have similar biogenesis being processed by Dicer enzymes and subsequent association with Argonaute enzymes. In plants, miRNAs and siRNAs have important functions in development, genome integrity and biotic and abiotic stress responses. The advances in high-throughtput sequencing and in silico analisys provide the uncover of new small non coding RNAs classes, many of them with unknown functions and biogenesis. tRNA derived small RNAs (tRFs) are a small non coding RNA class, that have as precursor a tRNA molecule. These were uncovers in the last decade in many organisms and, recently, in plants. Recent works detected tRFs from different sizes, with different source portions of the mature tRNA molecule (5’ end; 3’ end, anti-codon loop) and some from the tRNA precursor (pre-tRNA), suggesting that may be a novel class of small RNA and not random degradation products. Works in humans showed that some tRFs are processed by the Dicer enzymes, have association with the Argonaute enzymes and cell differentiation, tumor appearance and gene silencing related functions. Works in Arabidopsis and pumpkin (Cucurbita maxima) showed, respectively, that the tRFs have nutritional stress response possible functions and long distance signaling function between source and drain tissues, and may affect the translation. The tRFs biogenesis in plants are, until now an unknown, absence information about it in the literature and its possible biological functions are few studied yet, making then interesting target for studies among the small non coding RNAs in plants

Integridade dos dados meteorológicos obtidos por duas estações meteorológicas automatizadas

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Usinabilidade e integridade superficial de implantes dentários

Pós-graduação em Engenharia Mecânica - FEIS

Processo de reparo ósseo diante de três tipos de superfície de titânio: análise histomorfométrica e por microscopia eletrônica de varredura associada ao EDS: estudo experimental

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise do processo de fresamento de MDF em centro de usinagem CNC

Pós-graduação em Engenharia Mecânica - FEG