Boosting the optical properties of polylactic acid/ lanthanide-based metal-organic framework composites

Luminescent lanthanide metal-organic frameworks (LnMOF) are gathering much interest in the scientific community due to their exceptional optical properties, which have the potential to revolutionize several application fields, including anti-counterfeiting. The traceability of the original products is an ever- growing demand for producers and end-users to verify the authenticity of produced goods. Following this newfound need, we propose an anti-counterfeiting method based on a quick-response (QR) code, with a very specific verification procedure, using a luminescent LnMOF-based composite. The embedded code will only react to certain stimulation, hence it can only be unlocked using the sequence that is programmed to respond to. For that purpose, we explored the incorporation of fresh LnMOFs, with europium (EuMOF) and terbium (TbMOF), on a biodegradable polymer matrix of polylactic acid (PLA). A homogeneous mixture of PLA/LnMOF was produced via a two-step process including solvent casting followed by thermal mixing, after achieving the optimized concentration for each filler. The optical characterization of the fresh composites showed an excellent response to selective excitation, with well- defined intraionic lines for TbMOF @ 542 nm ( 5D4/7F5) and for EuMOF @ 615 nm (5D0/7F2). PLA/Eu, TbMOF composites were also explored to create an additional level of encryption by tuning the emitted color with the appropriate excitation stimuli. Hence, these new luminescent composite materials can be used as traceable optical tags for a wide variety of polymeric products, capable to respond to a very specific excitation wavelength and act as a level three luminescent security marker, whose decoding demands the assessment of more than one factor, with near-impossible replication. Additionally, this technology has a high potential for scalability since the applied processing techniques used for the production of the optically active QR code are commonly employed in the polymer industry. Never- theless, the analysis of the aged effects clearly indicates the need for a definition of new strategies to enhance the efficiency of the sensitization process of the Ln 3þ intraionic emission.publishe

Photometric analysis applied in determining facial type

INTRODUCTION: In orthodontics, determining the facial type is a key element in the prescription of a correct diagnosis. In the early days of our specialty, observation and measurement of craniofacial structures were done directly on the face, in photographs or plaster casts. With the development of radiographic methods, cephalometric analysis replaced the direct facial analysis. Seeking to validate the analysis of facial soft tissues, this work compares two different methods used to determining the facial types, the anthropometric and the cephalometric methods. METHODS: The sample consisted of sixty-four Brazilian individuals, adults, Caucasian, of both genders, who agreed to participate in this research. All individuals had lateral cephalograms and facial frontal photographs. The facial types were determined by the Vert Index (cephalometric) and the Facial Index (photographs). RESULTS: The agreement analysis (Kappa), made for both types of analysis, found an agreement of 76.5%. CONCLUSIONS: We concluded that the Facial Index can be used as an adjunct to orthodontic diagnosis, or as an alternative method for pre-selection of a sample, avoiding that research subjects have to undergo unnecessary tests.<br>INTRODUÇÃO: em Ortodontia, a determinação do tipo facial é um elemento-chave na prescrição de um diagnóstico correto. Nos primórdios de nossa especialidade, a observação e a medição das estruturas craniofaciais eram feitas diretamente na face, em fotografias ou em modelos de gesso. Com o desenvolvimento dos métodos radiográficos, a análise cefalométrica foi substituindo a análise facial direta. Visando legitimar o estudo dos tecidos moles faciais, esse trabalho comparou a determinação do tipo facial pelos métodos antropométrico e cefalométrico. MÉTODOS: a amostra constou de sessenta e quatro indivíduos brasileiros, adultos, leucodermas, de ambos os sexos, que aceitaram participar da pesquisa. De todos os indivíduos da amostra foram feitas telerradiografias laterais e fotografias faciais frontais, e os tipos faciais determinados pelo Índice Vert (cefalometricamente) e pelo Índice Facial (fotografias). RESULTADOS: pela análise de concordância (Kappa), feita para os dois tipos de análise, encontramos uma concordância de 76,5%. CONCLUSÕES: foi possível considerar que o Índice Facial pode ser utilizado como um coadjuvante do diagnóstico ortodôntico, ou como método alternativo para pré-seleção de uma amostra, evitando que os sujeitos de pesquisas sejam submetidos a exames desnecessários

Padrões cefalométricos de Ricketts aplicados a indivíduos brasileiros com oclusão excelente Ricketts cephalometric patterns applied to Brazilians individuals with excellent occlusion

OBJETIVO: avaliar cefalometricamente os 33 fatores cefalométricos, em norma lateral, dos 6 campos da análise de Ricketts em brasileiros e compará-los aos padrões cefalométricos de americanos. METODOLOGIA: foram avaliados75 indivíduos brasileiros leucodermas, com idade variando entre 12 e 15 anos, considerados de melhor estética, equilíbrio, harmonia facial e, principalmente, portadores de oclusão dentária excelente, selecionados em uma triagem de 14.000 escolares de 1º e 2º grau da região de Marília, Assis e Ourinhos/SP. Todos os 33 fatores das medidas cefalométricas dos 75 indivíduos foram comparados com os resultados obtidos por Ricketts em uma amostra de leucodermas americanos e submetidos a tratamento estatístico. RESULTADOS E CONCLUSÕES: foi possível concluir que 1) em nível esquelético, a maxila teve um comportamento dentro dos padrões preconizados pelo autor e a mandíbula teve uma tendência ao crescimento mais horizontal, tanto no seu corpo como no seu ramo; 2) a nível dentário, os incisivos inferiores se posicionaram mais anteriormente e com inclinação maior, o trespasse horizontal, vertical e a extrusão dos incisivos inferiores também estavam sensivelmente aumentados, provavelmente pela tendência ao crescimento horizontal da mandíbula; 3) o lábio inferior, em relação ao plano estético "E" de Ricketts, teve um posicionamento mais anterior em comparação ao padrão preconizado pelo autor; 4) os desvios clínicos na maioria dos fatores foram bem maiores nos brasileiros, em relação aos americanos, provavelmente devido à maior miscigenação nos leucodermas brasileiros.<br>AIM: to analyse the 33 cefalometric factors included in the six fields of Rickets analysis in a sample of Brazilians, and compare these values with cefalometric standards for North American individuals. METHODS: after having been chosen 75 Brazilian leucoderms, with age between 12 and 15, with better aesthetic aspects, balance, face harmony and mainly with excellent dental occlusion, results of a search in 14,000 students attending elementary and high school, in the area of Marília, Assis and Ourinhos/SP, all of the 33 factors of cephalometric measures of the 75 individuals were compared with the results obtained for Ricketts, in a sample of american leucoderms. RESULTS AND CONCLUSION: 1) under skeletal level, the maxilla presented a behavior according to the author’s proclaimed patterns. The jaw showed a more horizontal development trend in its branch; 2) under tooth structure level, the lower incisors located more foregoing and with bigger bending. The horizontal, vertical trespassing and the lower incisors extrusion presented themselves perceptibly increased, probably due to the jaw horizontal development trend; 3) related to "E" ‘Ricketts’ aesthetic planning, the lower lip showed a more anterior location related to the author’s claimed pattern; 4) The clinical deviations, in the most part of the factors, were very bigger in Brazilians than in Americans, probably related to the bigger miscegenation in the Brazilian leucoderms