The microstructure of a melt-spun Zr28Ni44Cu28 (at. %) alloy was characterized in order to determine the structures and compositions of the crystalline phases that compete with glass formation during rapid solidification. Two crystalline phases were identified, namely, a face centered cubic (FCC) zirconium oxide phase and a primitive cubic version of the big-cube oxide phase, using a combination of scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, and transmission electron microscopy techniques. Our results indicate that the Zr-O atomic pair interaction is preferential compared to the other atomic pair possibilities, supporting the formation of Zr-based oxides over the equilibrium phases in the ternary Zr-Ni-Cu system. Further, the results provide insight into the mechanisms of oxygen-induced crystallization in Zr-based BMGs and the corresponding decrease in glass forming ability (GFA) with increasing oxygen concentrations.

RESUMO Objetivo: Avaliar a inibição da proliferação de fibroblastos in vitro das conjuntivas obtidas através de exérese de pterígios de pacientes utilizando mitomicina C (MMC) e ciclofosfamida (CF). Métodos: Os pterígios foram retirados de 7 pacientes e submetidos a cultivo celular. Após o cultivo, 3 fragmentos de dimensões iguais deste material foram colhidos de áreas adjacentes do pterígio removido de cada paciente. Eles foram randomicamente selecionados de tal forma que: um fragmento de cada paciente foi exposto: ao meio de cultura (grupo controle), a MMC e a CF por igual período de tempo nas concentrações de 0,4 mg/ml e 10 mg/ml respectivamente. Após este período realizou-se a contagem celular de fibroblastos destes 3 grupos. Cada grupo continha 7 fragmentos. Resultados: Com a utilização da MMC tivemos uma taxa de 95% da inibição da proliferação dos fibroblastos, enquanto com a CF 100%. Conclusões: Ambas as drogas apresentaram elevada taxa da inibição da proliferação de fibroblastos, porém a CF apresentou inibição maior que a MMC.

Abstract Objective: To evaluate the inhibition of fibroblast proliferation in vitro of conjunctiva obtained by excision of pterygium from patients using mitomycin (MMC) and cyclophosphamide (CF). Methods: Pterygiums were removed from 7 patients and subjected to cell culture. After cell cultivation, 3 fragments of equal dimensions of these tissues were collected from adjacent areas of each patient removed pterygium. They were randomly selected in such a way that one fragment of each patient was exposed to: the culture medium (group control), to MMC and to CF for an equal period of time at concentrations of 0,4 mg/dl and 10 mg/dl respectively. After this period, the fibroblast cell count of these groups were performed. Each group had seven fragments. Results: With the use of MMC we had a 95% rate of inhibition of fibroblast proliferation, while with CF 100%. Conclusion: Both drugs showed a high rate of inhibition of fibroblast proliferation, but CF showed greater inhibition than MMC.

RESUMO Objetivo: Observar clinicamente os efeitos colaterais de injeção subconjuntival de ciclofosfamida, pensando em sua ação como um agente antifibrótico. Métodos: Estudo prospectivo realizado com 20 coelhos albinos da raça Nova Zelândia. Todos os coelhos foram submetidos a 0,3 ml de injeção subconjuntival de ciclofosfamida 10mg/ml no olho esquerdo e foram avaliados de acordo com os efeitos locais no primeiro dia após a injeção, 7, 30 e 60 dias. Foram examinados para detecção de reações oculares como necrose, hiperemia, quemose, secreção, opacidade corneana, irite além de alterações comportamentais e variação no consumo de água e alimentação. Resultados: Dos 20 coelhos estudados, apenas 3 apresentaram reações oculares e somente na leitura de 24 horas. Um coelho (5%) apresentou hiperemia, 1 coelho (5%) apresentou hiperemia associada a presença de irite e 1 coelho (5%) apresentou hiperemia associada a presença de secreção. As reações não foram mais observadas durante os exames de 7, 30 e 60 dias. Conclusão: A ciclofosfamida subconjuntival causou poucos efeitos colaterais na conjuntiva dos coelhos. Os únicos efeitos encontrados foram hiperemia, irite e secreção.

ABSTRACT Objective: To observe clinically, in rabbits, the side effects of topical injection of subconjunctival cyclophosphamide, studying its role as an antifibrotic drug. Methods: Prospective study in 20 albino rabbits of New Zealand race. All rabbits were treated with cyclophosphamide, 10mg/ml in a volume of 0.3 ml, in the left eye through subconjunctival injection. They were evaluated for 1, 7, 30, and 60 days after the procedure. All the animals were examined for the detection of ocular reactions such as necrosis, hyperemia, chemosis, secretion, opacity, and iritis. Other side effects as changes in the behavior, in the feed, and the water consumption were also evaluated. Results: It was observed that from the 20 rabbits studied, three rabbits (15%) showed side effects only at the 24 hours analysis. One rabbit (5%) presented hyperemia, one rabbit (5%) had hyperemia associated with iritis, and one rabbit (5%) presented hyperemia associated with secretion. These reactions were not observed at 1, 7, 30, and 60 days. Conclusion: Cyclophosphamide subconjunctival injection induces minor side effects on the conjunctiva of rabbits such as hyperemia, associated with iritis and secretion.

Abstract Zr-based bulk metallic glasses (BMGs) are widely used as mechanical components due to their excellent properties and high glass-forming ability. However, there is a lack of research concerning the tribological behavior of BMG versus BMG. The sliding characteristics of Vitreloy-105 (Zr52.2Cu17.9Ni14.6Al10Ti5 at.%) were studied in air using a pin-on-disk apparatus equipped for continuous measurement of friction force and without lubrication. The counterface material was the same BMG. The structure, thermal stability, and wear morphology were examined by X-ray diffraction, differential scanning calorimetry, non-contact profilometer, and scanning electron microscopy. For a normal load applied (10.0, 20.4 and 38.2 N) at constant 233 rpm the coefficient of friction ranged from 0.30 to 0.36 at steady state. Average wear rate was more pronounced on the pins under higher load and the predominant wear mechanism observed was adhesive, with presence of peeling-off and micro-cracks accompanied by some grooves and abrasive wear at lower loads.

Abstract This paper records the first occurrence of the genus Myrmicium Westwood, 1854 in the Cretaceous of Gondwana and describes it as a new species Myrmicium araripterum sp. nov, based on the most complete specimen of this genus yet known, which represents the largest specimen of the grade “Symphyta” ever found in the Crato Formation.

Based on the Fe60Cr8Nb8B24 alloy, reported in the literature as good Glass Forming Ability (GFA), in this study the GFA of two new compositions was proposed, Fe68-xCrxNb8B24 (x=10,12). They were evaluated as good candidates to be new compositions of Bulk Metallic Glasses (BMG) with better corrosion resistance due to the high Cr content. Rapidly solidified glassy ribbons were processed, and based on their thermal characteristics, the critical thickness of the glassy structure formation (Zc) was estimated. The critical thickness (Zc) obtained experimentally using the wedge-shaped casting method was evaluated and it presented a much lower value than that estimated theoretically. However, the GFA of the compositions analyzed was ranked and this ranking (i.e. whichever has the most or least GFA) is in agreement with the result predicted theoretically. The GFA of Fe58Cr10Nb8B24, which presented a maximum thickness of the amorphous region of wedge-shaped samples of about 0.6 mm (but estimated it would be 3.56 mm), offered good prospects to be a new Fe-based glass former alloy which has better resistance to corrosion than the Fe60Cr8Nb8B24 alloy reported.

A good glass former, Ti57.4Cu33.4Ni9.2, was selected using the topological instability criterion (lambda criterion) and the average electronegativity approach. The crystallization behavior and microstructural development of amorphous melt-spun ribbons of this new composition in response to heat treatment were investigated using a combination of differential scanning calorimetry (DSC), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The results indicate that the crystallization of the Ti57.4Cu33.4Ni9.2 alloy takes place through of three exothermic reactions with the nucleation of TiCu, Ti2Cu and Ti2Ni. The kinetics of crystallization were investigated by DSC, and the kinetic parameters were determined using Kissinger’s method.

OBJETIVOS: Identificar correlações entre as diferenças de medições de pressão intraocular (IOP) obtidas usando o tonômetro de aplanação de Goldmann (GAT) e três outros tonômetros (Tonômetro portátil de aplanação - TPA, Tonômetro de contorno dinâmico - TCD e Tono-Pen®) com características biométricas (diâmetro corneano, paquimetria, ceratometria e comprimento axial) em pacientes com glaucoma congênito. MÉTODOS: Estudo transversal prospectivo foi realizado em 46 olhos de 46 pacientes com glaucoma congênito. As medidas de pressão intraocular foram obtidas em todos os pacientes utilizando TAG, TPA, TCD e Tono-Pen®. Ceratometria, paquimetria, biometria e diâmetro corneano foram realizadas após mensuração da pressão intraocular. A ordem da utilização tonômetros foi aleatória. Correlações entre as diferenças de valores de PIO entre cada um dos três tonômetros (PIOs Delta) e o tonômetro de Goldmann e as características biométricas foram analisadas. RESULTADOS: PIO Delta do Tono-Pen®revelou correlação positiva moderada com ceratometria (r=0,41, p=0,004). As outras PIOs Delta não se correlacionaram significativamente com nenhuma das características biométricas. CONCLUSÕES: As diferenças entre as PIOs obtidas pelo TAG (padrão ouro) e TPA, TCD e Tono-Pen®parece não se correlacionar com a maioria das características biométricas. A única exceção foi a ceratometria, a qual se correlacionou de forma positiva e moderada com a PIO Delta do Tono-Pen®. Estes resultados indicam que o aumento da diferença entre a PIO obtida com TAG e Tono-Pen®aumenta com o encurvamento da curvatura corneana.

PURPOSE: To identify the correlation between the difference of intraocular pressure measurements (IOP) obtained using the Goldmann applanation tonometer (GAT) and three others tonometers (Handheld applanation tonometer - HAT, Dynamic contour tonometer - DCT and Tono-Pen®) with biometric characteristics (corneal diameter, pachymetry, keratometry and axial length) in patients with congenital glaucoma. METHODS: A cross-sectional study was performed on 46 eyes from 46 patients with congenital glaucoma. IOP measurements were obtained in all patients using GAT, HAT, DCT and Tono-Pen®. Keratometry, pachymetry, biometry and corneal diameter measurements were performed after the IOP measurement. The order of the tonometries was randomized. The correlations between the differences of IOP values of GAT and the other tonometers (Delta-IOP), and the different biometric parameters were studied. RESULTS: Tono-Pen® Delta IOP revealed moderate positive correlation to keratometry (r=0.41, p=0.004). The other Delta-IOPs showed no correlation with any of the biometric characteristics evaluated. CONCLUSIONS: IOP differences between GAT (gold standard) and GAT, HAT, DCT or Tono-Pen tonometers seem not to correlate with majority of ocular biometric characteristics. The only exception was the keratometry, which correlated in a positive and moderate way with Tono-Pen® Delta-IOP. This result suggests that the differences of IOP values of Tono-Pen® and GAT increase with the steepness of the cornea.

Este trabalho apresenta uma caracterização de sistemas epoxídicos a base do éter diglicidílico do bisfenol A (DGEBA), curado com dois co-monômeros do tipo amina cicloalifática - piperidina (Pip) e 4,4'-diamino-3,3'-dimetildiciclohexilmetano (3DCM) - antes e após a aplicação de irradiação com raios gama. Variações nas propriedades mecânicas e térmicas foram investigadas através de medidas do módulo elástico, da temperatura de transição vítrea e do perfil de degradação dos materiais. Foi possível observar que uma dose de irradiação de 50 kGy provoca variações sutis em propriedades como rigidez e estabilidade, que são relevantes do ponto de vista fundamental. Este trabalho permite afirmar que as variações de propriedades observadas não implicam em impacto negativo na utilização destes sistemas como biomaterial na área médica, considerando a etapa de esterilização por radiação de que são objeto.

Two epoxy polymers based on diglycidyl ether of bisphenol A (DGEBA), cured with piperidine (Pip) and 4,4'-diamino-3,3'-dimethyldicyclohexylmethane (3DCM), were characterized before and after treatment with γ irradiation. The changes in the mechanical and thermal properties were studied by elastic modulus, glass transition temperature and degradation temperature measurements. A dose of 50 kGy of irradiation caused subtle variations in properties such as rigidity and stability, which are relevant from the fundamental point of view. The variations do not imply on negative impact when considering the stage of sterilization during the use of these systems as a biomaterial in the medical area.

A combination of an extension of the topological instability "λ criterion" and the "average electronegativity" has been recently reported in the literature to predict compositions with high glass-forming ability (GFA). In the present work, both criteria have been applied to select the Ni61.0Nb36.0B3 alloy with a high glass-forming ability. Ingots were prepared by arc-melting and were used to produce ribbons processed by the melt-spinning technique further characterized by differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The Ni61.0Nb36.0B3 alloy revealed a complete amorphization and supercooled liquid region ΔTx = 68 K. In addition, wedge-shaped samples were prepared using copper mold casting in order to determine the critical thickness for amorphous formation. Scanning electron microscopy (SEM) revealed that fully amorphous samples could be obtained, reaching up to ~800 µm in thickness.

OBJETIVO: Estudar a distribuição da espessura corneana central e suas correlações com outros dados biométricos em pacientes com glaucoma congênito. MÉTODOS: Pacientes foram divididos em dois grupos, o A composto por portadores de glaucoma congênito, sendo este subdividido em subgrupos: com estrias de Haab (A1) e sem estrias de Haab (A2). O B representou o grupo controle. RESULTADOS: O grupo A apresentou diâmetro corneano entre 11 e 15,5 mm, com média de 14,13 mm e desvio padrão de 1,28, enquanto o grupo B apresentou valores entre 11,5 e 12,5 mm, com média de 12,01 mm com desvio padrão de 0,09 (t=-8,9723 e p=1,5083 em nível 0,05). Os glaucomatosos apresentaram maiores valores médios de diâmetro axial (t=-6,46315, p=9,2498 em nível de significância de 0,05), e menores valores médios ceratométricos em relação aos controles. O subgrupo A1 apresentou espessura corneana central de 539 ± 46 µm, o subgrupo A2 apresentou média de 571 ± 56 µm e o grupo B de 559 ± 28 µm (t=0,43746 e p=0,66291). As correlações entre diâmetro corneano e axial foram positivas nos dois grupos. Já entre diâmetro corneano e ceratometria média foram negativas nos dois grupos. CONCLUSÃO: Os glaucomatosos apresentaram maior média de diâmetro axial e menor média ceratométrica em relação aos controles. Não houve diferença estatisticamente significativa da espessura corneana central. O diâmetro corneano se correlacionou positivamente como diâmetro axial e negativamente com a ceratometria média. Não se pode estabelecer correlações entre espessura corneana central e os demais dados biométricos.

PURPOSE:To study the distribution of the central corneal thickness and its correlations with other biometric data in patients with congenital glaucoma. METHODS: Patients had been divided into two groups: group "A", composed of patients with congenital glaucoma, being subdivided in two sub-groups: with Haab striae (A1) and without Haab striae (A2), and group"B" that represented the controls. RESULTS: The group A presented corneal diameter between 11 and 15.5 mm, with mean of 14.13 mm and standard deviation (SD) of 1.28, while group B presented values between 11.5 and 12.5 mm, with average of 12.01 mm SD of 0.09 (t=-8.9723 and p=1.5083 in level 0.05). Glaucomatous patients presented greater mean values of axial diameter (t=-6.46315, p=9.2498 with level of significance of 0.05), and smaller mean keratometry in relation to the controls. The A1 sub-group presented mean central corneal thickness of 539 ± 46 µm, the A2 presented 571 ± 56 µm, and Group B 559 ± 28 µm (t=0.43746 and p=0.66291). The correlation between corneal and axial diameters was positive in both groups. The correlation between corneal diameter and mean keratometric values was negative in both groups. CONCLUSIONS: Patients with congenital glaucoma presented greater mean of axial dia meter and smaller mean keratometric values compared to the controls. No statistical significant difference of the central corneal thickness was demonstrated. Corneal and axial diameters were correlated positively. Corneal diameter was correlated negatively with the mean keratometry. It was not possible to establish correlations between the central corneal thickness and other biometric data.

A ecografia se constitui em método importante na avaliação de anormalidades do segmento posterior do globo ocular. OBJETIVO: Comparar as vantagens e desvantagens da sonda de 10 e 20 MHz da ultra-sonografia B-scan, na avaliação de imagens do segmento posterior do globo ocular. MÉTODOS: Pacientes acompanhados no ambulatório do Hospital das Clínicas da USP (HCFMUSP) entre fevereiro de 2006 e abril de 2007 foram submetidos a exame ultra-sonográfico usando o aparelho CINE-Scan® (Quantel Medical Inc.) com sondas de 10 e 20 MHz. Os pacientes foram examinados por três oftalmologistas experientes, em decúbito dorsal, após instilação de colírio de tetracaína a 1%, inicialmente com a sonda sobre as pálpebras e em seguida diretamente em contato com a esclera ou córnea. As imagens obtidas com sondas de 10 e 20 MHz foram comparadas entre si, durante e após a realização do exame. RESULTADOS: A sonda de 20 MHz mostrou-se superior na avaliação da detecção, forma e limites de estruturas do pólo posterior e a de 10 MHz avaliou com mais detalhes o humor vítreo. Não foram encontradas diferenças nas imagens obtidas com exame transpalpebral ou transescleral com a sonda de 10 MHz. Com a sonda de 20 MHz, as imagens obtidas em contato direto com o globo ocular apresentaram melhor qualidade. CONCLUSÕES: As sondas de 10 e 20 MHz têm diferentes intervalo de alcance ideal, assim como diferentes meios específicos de aquisição de melhores imagens.

The ultrasound is an important method in the evaluation of abnormalities of the posterior segment of the eye. PURPOSE: To compare the advantages and disadvantages of 10 and 20 MHz probe on B- scanning ultra-sonography in evaluation of vitreous and posterior pole diseases, providing recommendations for their use. METHODS: Patients from Hospital das Clinicas of the University of São Paulo (HC-FMUSP), attended between February 2006 and April 2007, were submitted to ultrasound exams using CINE-Scan® (Quantel Medical Inc) B-scan with 10 and 20MHz probe. The patients were examined by three experienced ophthalmologists, in horizontal dorsal position, after instillation of tetracaine 1% drops, first with the probe in direct contact with eyelids, and then with the probe placed directly in contact with the sclera or cornea. Theimages obtained were compared immediately during and after the examination. RESULTS: The 20 MHz probe reveled a superior resolution to study details, like shape and limits, on the posterior pole, and the 10 MHz probe provided better evaluation on vitreous humor. There were no differences if the exam was performed on eyelids or directly on sclera with the 10 MHz probe, but with the 20 MHz probe, the images had better resolution when the probe was used in direct contact with the eye. CONCLUSIONS: The 10 and 20 probes have different ideal range of reach, as different better specific means of image achieving.

Pilomatricoma é um tumor benigno oriundo do folículo pilossebáceo, que surge como nódulo intradérmico durante a infância na maioria dos casos. Geralmente é recoberto por pele normal, alcança em média diâmetro de 1,5 cm e frequentemente não recidiva após exérese cirúrgica. Os autores descrevem um caso no qual uma lesão tumoral iniciou seu crescimento na região superciliar esquerda de um paciente de 26 anos, sendo realizada exérese total da mesma e diagnóstico através do exame anatomopatológico de pilomatricoma. Esta lesão teve um crescimento lento, de aproximadamente dois anos, segundo o paciente. Decorridos oito meses da intervenção cirúrgica houve novo crescimento tumoral no local, desta vez de maneira rápida e exacerbada e com ulceração de pequena área da pele que recobria a lesão, induzindo, portanto, suspeita de malignidade. Realizada nova exérese com margem de segurança, o exame anatomopatológico confirmou ser a lesão um pilomatricoma, não possuindo a peça cirúrgica sinais de malignização. O paciente encontra-se em seguimento há um ano, sem sinais de recidiva até o momento.

Pilomatricoma is a benign neoplasm originated in the pilosebaceous follicle wich appears as an intradermal nodule during childhood, in most cases. It is generally covered with normal skin, reaching a diameter of 1.5 cm on average, and it often shows no recurrence after surgical excision. The authors describe a case in wich a 26-year-old patient presented a tumoral lesion on the upper left superciliary area was submitted to total excision, and diagnosed as pilomatricoma by the histological study. According to the patient, this lesion had a progressive and slow growth of about two years. Eight months after the first surgical intervention, there was a new tumor growth in the region, this time quicker and worsen, with ulceration on the small skin area that covered the lesion, thus leading to malignity suspicion. After the conduction of a new excision within a security margin, the histological test confirmed that it was a pilomatricoma lesion and the piece displayed no sign of malignity. The patient has been followed up for one year, showing no signs of recurrence so far.

INTRODUCTION: A cataract is defined as an opacity of any portion of the lens, regardless of visual acuity. In some advanced cases of cataracts, in which good fundus visualization is not possible, an ultrasound examination provides better assessment of the posterior segment of the globe. OBJECTIVES: This study aims to evaluate the ultrasonographic records of patients with advanced cataracts who were examined during cataract campaigns. METHODS: The ultrasonographic findings obtained from 215 patients examined in cataract campaigns conducted by the Hospital das Clínicas Department of Ophthalmology of the Faculdade de Medicina da Universidade de São Paulo between the years of 2005 and 2007 were evaluated, and the utility of this exam in changing the treatment procedures was studied. RESULTS: A total of 289 eyes from 215 patients were examined. Of the eyes examined, 77.5% presented with findings in the vitreous cavity and the posterior pole. A posterior vitreous detachment with no other complications was observed in 47.4% of the eyes. The remaining 30.1% presented with eye diseases that could result in a reduced visual function after surgery. The most frequent eye diseases observed were diffuse vitreous opacity (12.1% of the eyes) and detachment of the retina (9.3% of the eyes). DISCUSSION: In many cases, the ultrasonographic evaluation of the posterior segment revealed significant anomalies that changed the original treatment plan or contra-indicated surgery. At the very least, the evaluation was useful for patient counseling. CONCLUSION: The ultrasonographic examination revealed and differentiated between eyes with cataracts and eyes with ocular abnormalities other than cataracts as the cause of poor vision, thereby indicating the importance of its use during ocular evaluation.